1 /*#define CHASE_CHAIN*/
3 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998
4 * The Regents of the University of California. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that: (1) source code distributions
8 * retain the above copyright notice and this paragraph in its entirety, (2)
9 * distributions including binary code include the above copyright notice and
10 * this paragraph in its entirety in the documentation or other materials
11 * provided with the distribution, and (3) all advertising materials mentioning
12 * features or use of this software display the following acknowledgement:
13 * ``This product includes software developed by the University of California,
14 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
15 * the University nor the names of its contributors may be used to endorse
16 * or promote products derived from this software without specific prior
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
19 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
20 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
28 #include <pcap-stdinc.h>
35 #ifdef HAVE_SYS_BITYPES_H
36 #include <sys/bitypes.h>
38 #include <sys/types.h>
39 #include <sys/socket.h>
45 #include <sys/param.h>
48 #include <netinet/in.h>
49 #include <arpa/inet.h>
65 #include "ethertype.h"
69 #include "ieee80211.h"
71 #include "sunatmpos.h"
74 #include "pcap/ipnet.h"
80 #if defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER)
81 #include <linux/types.h>
82 #include <linux/if_packet.h>
83 #include <linux/filter.h>
86 #ifdef HAVE_NET_PFVAR_H
87 #include <sys/socket.h>
89 #include <net/pf/pfvar.h>
90 #include <net/pf/if_pflog.h>
94 #define offsetof(s, e) ((size_t)&((s *)0)->e)
99 #if defined(__MINGW32__) && defined(DEFINE_ADDITIONAL_IPV6_STUFF)
105 u_int8_t u6_addr8[16];
106 u_int16_t u6_addr16[8];
107 u_int32_t u6_addr32[4];
109 #define s6_addr in6_u.u6_addr8
110 #define s6_addr16 in6_u.u6_addr16
111 #define s6_addr32 in6_u.u6_addr32
112 #define s6_addr64 in6_u.u6_addr64
115 typedef unsigned short sa_family_t;
117 #define __SOCKADDR_COMMON(sa_prefix) \
118 sa_family_t sa_prefix##family
120 /* Ditto, for IPv6. */
123 __SOCKADDR_COMMON (sin6_);
124 u_int16_t sin6_port; /* Transport layer port # */
125 u_int32_t sin6_flowinfo; /* IPv6 flow information */
126 struct in6_addr sin6_addr; /* IPv6 address */
129 #ifndef EAI_ADDRFAMILY
131 int ai_flags; /* AI_PASSIVE, AI_CANONNAME */
132 int ai_family; /* PF_xxx */
133 int ai_socktype; /* SOCK_xxx */
134 int ai_protocol; /* 0 or IPPROTO_xxx for IPv4 and IPv6 */
135 size_t ai_addrlen; /* length of ai_addr */
136 char *ai_canonname; /* canonical name for hostname */
137 struct sockaddr *ai_addr; /* binary address */
138 struct addrinfo *ai_next; /* next structure in linked list */
140 #endif /* EAI_ADDRFAMILY */
141 #endif /* defined(__MINGW32__) && defined(DEFINE_ADDITIONAL_IPV6_STUFF) */
143 #include <netdb.h> /* for "struct addrinfo" */
146 #include <pcap/namedb.h>
148 #include "nametoaddr.h"
150 #define ETHERMTU 1500
152 #ifndef ETHERTYPE_TEB
153 #define ETHERTYPE_TEB 0x6558
156 #ifndef IPPROTO_HOPOPTS
157 #define IPPROTO_HOPOPTS 0
159 #ifndef IPPROTO_ROUTING
160 #define IPPROTO_ROUTING 43
162 #ifndef IPPROTO_FRAGMENT
163 #define IPPROTO_FRAGMENT 44
165 #ifndef IPPROTO_DSTOPTS
166 #define IPPROTO_DSTOPTS 60
169 #define IPPROTO_SCTP 132
172 #define GENEVE_PORT 6081
174 #ifdef HAVE_OS_PROTO_H
175 #include "os-proto.h"
178 #define JMP(c) ((c)|BPF_JMP|BPF_K)
181 * "Push" the current value of the link-layer header type and link-layer
182 * header offset onto a "stack", and set a new value. (It's not a
183 * full-blown stack; we keep only the top two items.)
185 #define PUSH_LINKHDR(cs, new_linktype, new_is_variable, new_constant_part, new_reg) \
187 (cs)->prevlinktype = (cs)->linktype; \
188 (cs)->off_prevlinkhdr = (cs)->off_linkhdr; \
189 (cs)->linktype = (new_linktype); \
190 (cs)->off_linkhdr.is_variable = (new_is_variable); \
191 (cs)->off_linkhdr.constant_part = (new_constant_part); \
192 (cs)->off_linkhdr.reg = (new_reg); \
193 (cs)->is_geneve = 0; \
197 * Offset "not set" value.
199 #define OFFSET_NOT_SET 0xffffffffU
202 * Absolute offsets, which are offsets from the beginning of the raw
203 * packet data, are, in the general case, the sum of a variable value
204 * and a constant value; the variable value may be absent, in which
205 * case the offset is only the constant value, and the constant value
206 * may be zero, in which case the offset is only the variable value.
208 * bpf_abs_offset is a structure containing all that information:
210 * is_variable is 1 if there's a variable part.
212 * constant_part is the constant part of the value, possibly zero;
214 * if is_variable is 1, reg is the register number for a register
215 * containing the variable value if the register has been assigned,
225 * Value passed to gen_load_a() to indicate what the offset argument
226 * is relative to the beginning of.
229 OR_PACKET, /* full packet data */
230 OR_LINKHDR, /* link-layer header */
231 OR_PREVLINKHDR, /* previous link-layer header */
232 OR_LLC, /* 802.2 LLC header */
233 OR_PREVMPLSHDR, /* previous MPLS header */
234 OR_LINKTYPE, /* link-layer type */
235 OR_LINKPL, /* link-layer payload */
236 OR_LINKPL_NOSNAP, /* link-layer payload, with no SNAP header at the link layer */
237 OR_TRAN_IPV4, /* transport-layer header, with IPv4 network layer */
238 OR_TRAN_IPV6 /* transport-layer header, with IPv6 network layer */
242 * We divy out chunks of memory rather than call malloc each time so
243 * we don't have to worry about leaking memory. It's probably
244 * not a big deal if all this memory was wasted but if this ever
245 * goes into a library that would probably not be a good idea.
247 * XXX - this *is* in a library....
250 #define CHUNK0SIZE 1024
256 /* Code generator state */
258 struct _compiler_state {
268 int outermostlinktype;
273 /* Hack for handling VLAN and MPLS stacks. */
274 u_int label_stack_depth;
275 u_int vlan_stack_depth;
282 * As errors are handled by a longjmp, anything allocated must
283 * be freed in the longjmp handler, so it must be reachable
286 * One thing that's allocated is the result of pcap_nametoaddrinfo();
287 * it must be freed with freeaddrinfo(). This variable points to
288 * any addrinfo structure that would need to be freed.
294 * Various code constructs need to know the layout of the packet.
295 * These values give the necessary offsets from the beginning
296 * of the packet data.
300 * Absolute offset of the beginning of the link-layer header.
302 bpf_abs_offset off_linkhdr;
305 * If we're checking a link-layer header for a packet encapsulated
306 * in another protocol layer, this is the equivalent information
307 * for the previous layers' link-layer header from the beginning
308 * of the raw packet data.
310 bpf_abs_offset off_prevlinkhdr;
313 * This is the equivalent information for the outermost layers'
316 bpf_abs_offset off_outermostlinkhdr;
319 * Absolute offset of the beginning of the link-layer payload.
321 bpf_abs_offset off_linkpl;
324 * "off_linktype" is the offset to information in the link-layer
325 * header giving the packet type. This is an absolute offset
326 * from the beginning of the packet.
328 * For Ethernet, it's the offset of the Ethernet type field; this
329 * means that it must have a value that skips VLAN tags.
331 * For link-layer types that always use 802.2 headers, it's the
332 * offset of the LLC header; this means that it must have a value
333 * that skips VLAN tags.
335 * For PPP, it's the offset of the PPP type field.
337 * For Cisco HDLC, it's the offset of the CHDLC type field.
339 * For BSD loopback, it's the offset of the AF_ value.
341 * For Linux cooked sockets, it's the offset of the type field.
343 * off_linktype.constant_part is set to OFFSET_NOT_SET for no
344 * encapsulation, in which case, IP is assumed.
346 bpf_abs_offset off_linktype;
349 * TRUE if the link layer includes an ATM pseudo-header.
354 * TRUE if "geneve" appeared in the filter; it causes us to
355 * generate code that checks for a Geneve header and assume
356 * that later filters apply to the encapsulated payload.
361 * These are offsets for the ATM pseudo-header.
368 * These are offsets for the MTP2 fields.
374 * These are offsets for the MTP3 fields.
382 * This is the offset of the first byte after the ATM pseudo_header,
383 * or -1 if there is no ATM pseudo-header.
388 * These are offsets to the beginning of the network-layer header.
389 * They are relative to the beginning of the link-layer payload
390 * (i.e., they don't include off_linkhdr.constant_part or
391 * off_linkpl.constant_part).
393 * If the link layer never uses 802.2 LLC:
395 * "off_nl" and "off_nl_nosnap" are the same.
397 * If the link layer always uses 802.2 LLC:
399 * "off_nl" is the offset if there's a SNAP header following
402 * "off_nl_nosnap" is the offset if there's no SNAP header.
404 * If the link layer is Ethernet:
406 * "off_nl" is the offset if the packet is an Ethernet II packet
407 * (we assume no 802.3+802.2+SNAP);
409 * "off_nl_nosnap" is the offset if the packet is an 802.3 packet
410 * with an 802.2 header following it.
416 * Here we handle simple allocation of the scratch registers.
417 * If too many registers are alloc'd, the allocator punts.
419 int regused[BPF_MEMWORDS];
425 struct chunk chunks[NCHUNKS];
430 bpf_syntax_error(compiler_state_t *cstate, const char *msg)
432 bpf_error(cstate, "syntax error in filter expression: %s", msg);
438 bpf_error(compiler_state_t *cstate, const char *fmt, ...)
443 if (cstate->bpf_pcap != NULL)
444 (void)pcap_vsnprintf(pcap_geterr(cstate->bpf_pcap),
445 PCAP_ERRBUF_SIZE, fmt, ap);
447 longjmp(cstate->top_ctx, 1);
451 static void init_linktype(compiler_state_t *, pcap_t *);
453 static void init_regs(compiler_state_t *);
454 static int alloc_reg(compiler_state_t *);
455 static void free_reg(compiler_state_t *, int);
457 static void initchunks(compiler_state_t *cstate);
458 static void *newchunk(compiler_state_t *cstate, size_t);
459 static void freechunks(compiler_state_t *cstate);
460 static inline struct block *new_block(compiler_state_t *cstate, int);
461 static inline struct slist *new_stmt(compiler_state_t *cstate, int);
462 static struct block *gen_retblk(compiler_state_t *cstate, int);
463 static inline void syntax(compiler_state_t *cstate);
465 static void backpatch(struct block *, struct block *);
466 static void merge(struct block *, struct block *);
467 static struct block *gen_cmp(compiler_state_t *, enum e_offrel, u_int,
469 static struct block *gen_cmp_gt(compiler_state_t *, enum e_offrel, u_int,
471 static struct block *gen_cmp_ge(compiler_state_t *, enum e_offrel, u_int,
473 static struct block *gen_cmp_lt(compiler_state_t *, enum e_offrel, u_int,
475 static struct block *gen_cmp_le(compiler_state_t *, enum e_offrel, u_int,
477 static struct block *gen_mcmp(compiler_state_t *, enum e_offrel, u_int,
478 u_int, bpf_int32, bpf_u_int32);
479 static struct block *gen_bcmp(compiler_state_t *, enum e_offrel, u_int,
480 u_int, const u_char *);
481 static struct block *gen_ncmp(compiler_state_t *, enum e_offrel, bpf_u_int32,
482 bpf_u_int32, bpf_u_int32, bpf_u_int32, int, bpf_int32);
483 static struct slist *gen_load_absoffsetrel(compiler_state_t *, bpf_abs_offset *,
485 static struct slist *gen_load_a(compiler_state_t *, enum e_offrel, u_int,
487 static struct slist *gen_loadx_iphdrlen(compiler_state_t *);
488 static struct block *gen_uncond(compiler_state_t *, int);
489 static inline struct block *gen_true(compiler_state_t *);
490 static inline struct block *gen_false(compiler_state_t *);
491 static struct block *gen_ether_linktype(compiler_state_t *, int);
492 static struct block *gen_ipnet_linktype(compiler_state_t *, int);
493 static struct block *gen_linux_sll_linktype(compiler_state_t *, int);
494 static struct slist *gen_load_prism_llprefixlen(compiler_state_t *);
495 static struct slist *gen_load_avs_llprefixlen(compiler_state_t *);
496 static struct slist *gen_load_radiotap_llprefixlen(compiler_state_t *);
497 static struct slist *gen_load_ppi_llprefixlen(compiler_state_t *);
498 static void insert_compute_vloffsets(compiler_state_t *, struct block *);
499 static struct slist *gen_abs_offset_varpart(compiler_state_t *,
501 static int ethertype_to_ppptype(int);
502 static struct block *gen_linktype(compiler_state_t *, int);
503 static struct block *gen_snap(compiler_state_t *, bpf_u_int32, bpf_u_int32);
504 static struct block *gen_llc_linktype(compiler_state_t *, int);
505 static struct block *gen_hostop(compiler_state_t *, bpf_u_int32, bpf_u_int32,
506 int, int, u_int, u_int);
508 static struct block *gen_hostop6(compiler_state_t *, struct in6_addr *,
509 struct in6_addr *, int, int, u_int, u_int);
511 static struct block *gen_ahostop(compiler_state_t *, const u_char *, int);
512 static struct block *gen_ehostop(compiler_state_t *, const u_char *, int);
513 static struct block *gen_fhostop(compiler_state_t *, const u_char *, int);
514 static struct block *gen_thostop(compiler_state_t *, const u_char *, int);
515 static struct block *gen_wlanhostop(compiler_state_t *, const u_char *, int);
516 static struct block *gen_ipfchostop(compiler_state_t *, const u_char *, int);
517 static struct block *gen_dnhostop(compiler_state_t *, bpf_u_int32, int);
518 static struct block *gen_mpls_linktype(compiler_state_t *, int);
519 static struct block *gen_host(compiler_state_t *, bpf_u_int32, bpf_u_int32,
522 static struct block *gen_host6(compiler_state_t *, struct in6_addr *,
523 struct in6_addr *, int, int, int);
526 static struct block *gen_gateway(const u_char *, bpf_u_int32 **, int, int);
528 static struct block *gen_ipfrag(compiler_state_t *);
529 static struct block *gen_portatom(compiler_state_t *, int, bpf_int32);
530 static struct block *gen_portrangeatom(compiler_state_t *, int, bpf_int32,
532 static struct block *gen_portatom6(compiler_state_t *, int, bpf_int32);
533 static struct block *gen_portrangeatom6(compiler_state_t *, int, bpf_int32,
535 struct block *gen_portop(compiler_state_t *, int, int, int);
536 static struct block *gen_port(compiler_state_t *, int, int, int);
537 struct block *gen_portrangeop(compiler_state_t *, int, int, int, int);
538 static struct block *gen_portrange(compiler_state_t *, int, int, int, int);
539 struct block *gen_portop6(compiler_state_t *, int, int, int);
540 static struct block *gen_port6(compiler_state_t *, int, int, int);
541 struct block *gen_portrangeop6(compiler_state_t *, int, int, int, int);
542 static struct block *gen_portrange6(compiler_state_t *, int, int, int, int);
543 static int lookup_proto(compiler_state_t *, const char *, int);
544 static struct block *gen_protochain(compiler_state_t *, int, int, int);
545 static struct block *gen_proto(compiler_state_t *, int, int, int);
546 static struct slist *xfer_to_x(compiler_state_t *, struct arth *);
547 static struct slist *xfer_to_a(compiler_state_t *, struct arth *);
548 static struct block *gen_mac_multicast(compiler_state_t *, int);
549 static struct block *gen_len(compiler_state_t *, int, int);
550 static struct block *gen_check_802_11_data_frame(compiler_state_t *);
551 static struct block *gen_geneve_ll_check(compiler_state_t *cstate);
553 static struct block *gen_ppi_dlt_check(compiler_state_t *);
554 static struct block *gen_msg_abbrev(compiler_state_t *, int type);
557 initchunks(compiler_state_t *cstate)
561 for (i = 0; i < NCHUNKS; i++) {
562 cstate->chunks[i].n_left = 0;
563 cstate->chunks[i].m = NULL;
565 cstate->cur_chunk = 0;
569 newchunk(compiler_state_t *cstate, size_t n)
576 /* XXX Round up to nearest long. */
577 n = (n + sizeof(long) - 1) & ~(sizeof(long) - 1);
579 /* XXX Round up to structure boundary. */
583 cp = &cstate->chunks[cstate->cur_chunk];
584 if (n > cp->n_left) {
585 ++cp, k = ++cstate->cur_chunk;
587 bpf_error(cstate, "out of memory");
588 size = CHUNK0SIZE << k;
589 cp->m = (void *)malloc(size);
591 bpf_error(cstate, "out of memory");
592 memset((char *)cp->m, 0, size);
595 bpf_error(cstate, "out of memory");
598 return (void *)((char *)cp->m + cp->n_left);
602 freechunks(compiler_state_t *cstate)
606 for (i = 0; i < NCHUNKS; ++i)
607 if (cstate->chunks[i].m != NULL)
608 free(cstate->chunks[i].m);
612 * A strdup whose allocations are freed after code generation is over.
615 sdup(compiler_state_t *cstate, const char *s)
617 size_t n = strlen(s) + 1;
618 char *cp = newchunk(cstate, n);
624 static inline struct block *
625 new_block(compiler_state_t *cstate, int code)
629 p = (struct block *)newchunk(cstate, sizeof(*p));
636 static inline struct slist *
637 new_stmt(compiler_state_t *cstate, int code)
641 p = (struct slist *)newchunk(cstate, sizeof(*p));
647 static struct block *
648 gen_retblk(compiler_state_t *cstate, int v)
650 struct block *b = new_block(cstate, BPF_RET|BPF_K);
657 syntax(compiler_state_t *cstate)
659 bpf_error(cstate, "syntax error in filter expression");
663 pcap_compile(pcap_t *p, struct bpf_program *program,
664 const char *buf, int optimize, bpf_u_int32 mask)
666 compiler_state_t cstate;
667 const char * volatile xbuf = buf;
668 yyscan_t scanner = NULL;
669 YY_BUFFER_STATE in_buffer = NULL;
682 * If this pcap_t hasn't been activated, it doesn't have a
683 * link-layer type, so we can't use it.
686 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
687 "not-yet-activated pcap_t passed to pcap_compile");
692 cstate.no_optimize = 0;
694 cstate.ic.root = NULL;
695 cstate.ic.cur_mark = 0;
699 if (setjmp(cstate.top_ctx)) {
701 if (cstate.ai != NULL)
702 freeaddrinfo(cstate.ai);
708 cstate.netmask = mask;
710 cstate.snaplen = pcap_snapshot(p);
711 if (cstate.snaplen == 0) {
712 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
713 "snaplen of 0 rejects all packets");
718 if (pcap_lex_init(&scanner) != 0)
719 bpf_error(&cstate, "can't initialize scanner: %s", pcap_strerror(errno));
720 in_buffer = pcap__scan_string(xbuf ? xbuf : "", scanner);
723 * Associate the compiler state with the lexical analyzer
726 pcap_set_extra(&cstate, scanner);
728 init_linktype(&cstate, p);
729 (void)pcap_parse(scanner, &cstate);
731 if (cstate.ic.root == NULL)
732 cstate.ic.root = gen_retblk(&cstate, cstate.snaplen);
734 if (optimize && !cstate.no_optimize) {
735 bpf_optimize(&cstate, &cstate.ic);
736 if (cstate.ic.root == NULL ||
737 (cstate.ic.root->s.code == (BPF_RET|BPF_K) && cstate.ic.root->s.k == 0))
738 bpf_error(&cstate, "expression rejects all packets");
740 program->bf_insns = icode_to_fcode(&cstate, &cstate.ic, cstate.ic.root, &len);
741 program->bf_len = len;
743 rc = 0; /* We're all okay */
747 * Clean up everything for the lexical analyzer.
749 if (in_buffer != NULL)
750 pcap__delete_buffer(in_buffer, scanner);
752 pcap_lex_destroy(scanner);
755 * Clean up our own allocated memory.
763 * entry point for using the compiler with no pcap open
764 * pass in all the stuff that is needed explicitly instead.
767 pcap_compile_nopcap(int snaplen_arg, int linktype_arg,
768 struct bpf_program *program,
769 const char *buf, int optimize, bpf_u_int32 mask)
774 p = pcap_open_dead(linktype_arg, snaplen_arg);
777 ret = pcap_compile(p, program, buf, optimize, mask);
783 * Clean up a "struct bpf_program" by freeing all the memory allocated
787 pcap_freecode(struct bpf_program *program)
790 if (program->bf_insns != NULL) {
791 free((char *)program->bf_insns);
792 program->bf_insns = NULL;
797 * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates
798 * which of the jt and jf fields has been resolved and which is a pointer
799 * back to another unresolved block (or nil). At least one of the fields
800 * in each block is already resolved.
803 backpatch(list, target)
804 struct block *list, *target;
821 * Merge the lists in b0 and b1, using the 'sense' field to indicate
822 * which of jt and jf is the link.
826 struct block *b0, *b1;
828 register struct block **p = &b0;
830 /* Find end of list. */
832 p = !((*p)->sense) ? &JT(*p) : &JF(*p);
834 /* Concatenate the lists. */
839 finish_parse(compiler_state_t *cstate, struct block *p)
841 struct block *ppi_dlt_check;
844 * Insert before the statements of the first (root) block any
845 * statements needed to load the lengths of any variable-length
846 * headers into registers.
848 * XXX - a fancier strategy would be to insert those before the
849 * statements of all blocks that use those lengths and that
850 * have no predecessors that use them, so that we only compute
851 * the lengths if we need them. There might be even better
852 * approaches than that.
854 * However, those strategies would be more complicated, and
855 * as we don't generate code to compute a length if the
856 * program has no tests that use the length, and as most
857 * tests will probably use those lengths, we would just
858 * postpone computing the lengths so that it's not done
859 * for tests that fail early, and it's not clear that's
862 insert_compute_vloffsets(cstate, p->head);
865 * For DLT_PPI captures, generate a check of the per-packet
866 * DLT value to make sure it's DLT_IEEE802_11.
868 * XXX - TurboCap cards use DLT_PPI for Ethernet.
869 * Can we just define some DLT_ETHERNET_WITH_PHDR pseudo-header
870 * with appropriate Ethernet information and use that rather
871 * than using something such as DLT_PPI where you don't know
872 * the link-layer header type until runtime, which, in the
873 * general case, would force us to generate both Ethernet *and*
874 * 802.11 code (*and* anything else for which PPI is used)
875 * and choose between them early in the BPF program?
877 ppi_dlt_check = gen_ppi_dlt_check(cstate);
878 if (ppi_dlt_check != NULL)
879 gen_and(ppi_dlt_check, p);
881 backpatch(p, gen_retblk(cstate, cstate->snaplen));
882 p->sense = !p->sense;
883 backpatch(p, gen_retblk(cstate, 0));
884 cstate->ic.root = p->head;
889 struct block *b0, *b1;
891 backpatch(b0, b1->head);
892 b0->sense = !b0->sense;
893 b1->sense = !b1->sense;
895 b1->sense = !b1->sense;
901 struct block *b0, *b1;
903 b0->sense = !b0->sense;
904 backpatch(b0, b1->head);
905 b0->sense = !b0->sense;
914 b->sense = !b->sense;
917 static struct block *
918 gen_cmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
919 u_int size, bpf_int32 v)
921 return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JEQ, 0, v);
924 static struct block *
925 gen_cmp_gt(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
926 u_int size, bpf_int32 v)
928 return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGT, 0, v);
931 static struct block *
932 gen_cmp_ge(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
933 u_int size, bpf_int32 v)
935 return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGE, 0, v);
938 static struct block *
939 gen_cmp_lt(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
940 u_int size, bpf_int32 v)
942 return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGE, 1, v);
945 static struct block *
946 gen_cmp_le(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
947 u_int size, bpf_int32 v)
949 return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGT, 1, v);
952 static struct block *
953 gen_mcmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
954 u_int size, bpf_int32 v, bpf_u_int32 mask)
956 return gen_ncmp(cstate, offrel, offset, size, mask, BPF_JEQ, 0, v);
959 static struct block *
960 gen_bcmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
961 u_int size, const u_char *v)
963 register struct block *b, *tmp;
967 register const u_char *p = &v[size - 4];
968 bpf_int32 w = ((bpf_int32)p[0] << 24) |
969 ((bpf_int32)p[1] << 16) | ((bpf_int32)p[2] << 8) | p[3];
971 tmp = gen_cmp(cstate, offrel, offset + size - 4, BPF_W, w);
978 register const u_char *p = &v[size - 2];
979 bpf_int32 w = ((bpf_int32)p[0] << 8) | p[1];
981 tmp = gen_cmp(cstate, offrel, offset + size - 2, BPF_H, w);
988 tmp = gen_cmp(cstate, offrel, offset, BPF_B, (bpf_int32)v[0]);
997 * AND the field of size "size" at offset "offset" relative to the header
998 * specified by "offrel" with "mask", and compare it with the value "v"
999 * with the test specified by "jtype"; if "reverse" is true, the test
1000 * should test the opposite of "jtype".
1002 static struct block *
1003 gen_ncmp(compiler_state_t *cstate, enum e_offrel offrel, bpf_u_int32 offset,
1004 bpf_u_int32 size, bpf_u_int32 mask, bpf_u_int32 jtype, int reverse,
1007 struct slist *s, *s2;
1010 s = gen_load_a(cstate, offrel, offset, size);
1012 if (mask != 0xffffffff) {
1013 s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
1018 b = new_block(cstate, JMP(jtype));
1021 if (reverse && (jtype == BPF_JGT || jtype == BPF_JGE))
1027 init_linktype(compiler_state_t *cstate, pcap_t *p)
1029 cstate->pcap_fddipad = p->fddipad;
1032 * We start out with only one link-layer header.
1034 cstate->outermostlinktype = pcap_datalink(p);
1035 cstate->off_outermostlinkhdr.constant_part = 0;
1036 cstate->off_outermostlinkhdr.is_variable = 0;
1037 cstate->off_outermostlinkhdr.reg = -1;
1039 cstate->prevlinktype = cstate->outermostlinktype;
1040 cstate->off_prevlinkhdr.constant_part = 0;
1041 cstate->off_prevlinkhdr.is_variable = 0;
1042 cstate->off_prevlinkhdr.reg = -1;
1044 cstate->linktype = cstate->outermostlinktype;
1045 cstate->off_linkhdr.constant_part = 0;
1046 cstate->off_linkhdr.is_variable = 0;
1047 cstate->off_linkhdr.reg = -1;
1052 cstate->off_linkpl.constant_part = 0;
1053 cstate->off_linkpl.is_variable = 0;
1054 cstate->off_linkpl.reg = -1;
1056 cstate->off_linktype.constant_part = 0;
1057 cstate->off_linktype.is_variable = 0;
1058 cstate->off_linktype.reg = -1;
1061 * Assume it's not raw ATM with a pseudo-header, for now.
1064 cstate->off_vpi = -1;
1065 cstate->off_vci = -1;
1066 cstate->off_proto = -1;
1067 cstate->off_payload = -1;
1072 cstate->is_geneve = 0;
1075 * And assume we're not doing SS7.
1077 cstate->off_li = -1;
1078 cstate->off_li_hsl = -1;
1079 cstate->off_sio = -1;
1080 cstate->off_opc = -1;
1081 cstate->off_dpc = -1;
1082 cstate->off_sls = -1;
1084 cstate->label_stack_depth = 0;
1085 cstate->vlan_stack_depth = 0;
1087 switch (cstate->linktype) {
1090 cstate->off_linktype.constant_part = 2;
1091 cstate->off_linkpl.constant_part = 6;
1092 cstate->off_nl = 0; /* XXX in reality, variable! */
1093 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1096 case DLT_ARCNET_LINUX:
1097 cstate->off_linktype.constant_part = 4;
1098 cstate->off_linkpl.constant_part = 8;
1099 cstate->off_nl = 0; /* XXX in reality, variable! */
1100 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1104 cstate->off_linktype.constant_part = 12;
1105 cstate->off_linkpl.constant_part = 14; /* Ethernet header length */
1106 cstate->off_nl = 0; /* Ethernet II */
1107 cstate->off_nl_nosnap = 3; /* 802.3+802.2 */
1112 * SLIP doesn't have a link level type. The 16 byte
1113 * header is hacked into our SLIP driver.
1115 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1116 cstate->off_linkpl.constant_part = 16;
1118 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1121 case DLT_SLIP_BSDOS:
1122 /* XXX this may be the same as the DLT_PPP_BSDOS case */
1123 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1125 cstate->off_linkpl.constant_part = 24;
1127 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1132 cstate->off_linktype.constant_part = 0;
1133 cstate->off_linkpl.constant_part = 4;
1135 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1139 cstate->off_linktype.constant_part = 0;
1140 cstate->off_linkpl.constant_part = 12;
1142 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1147 case DLT_C_HDLC: /* BSD/OS Cisco HDLC */
1148 case DLT_PPP_SERIAL: /* NetBSD sync/async serial PPP */
1149 cstate->off_linktype.constant_part = 2; /* skip HDLC-like framing */
1150 cstate->off_linkpl.constant_part = 4; /* skip HDLC-like framing and protocol field */
1152 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1157 * This does no include the Ethernet header, and
1158 * only covers session state.
1160 cstate->off_linktype.constant_part = 6;
1161 cstate->off_linkpl.constant_part = 8;
1163 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1167 cstate->off_linktype.constant_part = 5;
1168 cstate->off_linkpl.constant_part = 24;
1170 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1175 * FDDI doesn't really have a link-level type field.
1176 * We set "off_linktype" to the offset of the LLC header.
1178 * To check for Ethernet types, we assume that SSAP = SNAP
1179 * is being used and pick out the encapsulated Ethernet type.
1180 * XXX - should we generate code to check for SNAP?
1182 cstate->off_linktype.constant_part = 13;
1183 cstate->off_linktype.constant_part += cstate->pcap_fddipad;
1184 cstate->off_linkpl.constant_part = 13; /* FDDI MAC header length */
1185 cstate->off_linkpl.constant_part += cstate->pcap_fddipad;
1186 cstate->off_nl = 8; /* 802.2+SNAP */
1187 cstate->off_nl_nosnap = 3; /* 802.2 */
1192 * Token Ring doesn't really have a link-level type field.
1193 * We set "off_linktype" to the offset of the LLC header.
1195 * To check for Ethernet types, we assume that SSAP = SNAP
1196 * is being used and pick out the encapsulated Ethernet type.
1197 * XXX - should we generate code to check for SNAP?
1199 * XXX - the header is actually variable-length.
1200 * Some various Linux patched versions gave 38
1201 * as "off_linktype" and 40 as "off_nl"; however,
1202 * if a token ring packet has *no* routing
1203 * information, i.e. is not source-routed, the correct
1204 * values are 20 and 22, as they are in the vanilla code.
1206 * A packet is source-routed iff the uppermost bit
1207 * of the first byte of the source address, at an
1208 * offset of 8, has the uppermost bit set. If the
1209 * packet is source-routed, the total number of bytes
1210 * of routing information is 2 plus bits 0x1F00 of
1211 * the 16-bit value at an offset of 14 (shifted right
1212 * 8 - figure out which byte that is).
1214 cstate->off_linktype.constant_part = 14;
1215 cstate->off_linkpl.constant_part = 14; /* Token Ring MAC header length */
1216 cstate->off_nl = 8; /* 802.2+SNAP */
1217 cstate->off_nl_nosnap = 3; /* 802.2 */
1220 case DLT_PRISM_HEADER:
1221 case DLT_IEEE802_11_RADIO_AVS:
1222 case DLT_IEEE802_11_RADIO:
1223 cstate->off_linkhdr.is_variable = 1;
1224 /* Fall through, 802.11 doesn't have a variable link
1225 * prefix but is otherwise the same. */
1227 case DLT_IEEE802_11:
1229 * 802.11 doesn't really have a link-level type field.
1230 * We set "off_linktype.constant_part" to the offset of
1233 * To check for Ethernet types, we assume that SSAP = SNAP
1234 * is being used and pick out the encapsulated Ethernet type.
1235 * XXX - should we generate code to check for SNAP?
1237 * We also handle variable-length radio headers here.
1238 * The Prism header is in theory variable-length, but in
1239 * practice it's always 144 bytes long. However, some
1240 * drivers on Linux use ARPHRD_IEEE80211_PRISM, but
1241 * sometimes or always supply an AVS header, so we
1242 * have to check whether the radio header is a Prism
1243 * header or an AVS header, so, in practice, it's
1246 cstate->off_linktype.constant_part = 24;
1247 cstate->off_linkpl.constant_part = 0; /* link-layer header is variable-length */
1248 cstate->off_linkpl.is_variable = 1;
1249 cstate->off_nl = 8; /* 802.2+SNAP */
1250 cstate->off_nl_nosnap = 3; /* 802.2 */
1255 * At the moment we treat PPI the same way that we treat
1256 * normal Radiotap encoded packets. The difference is in
1257 * the function that generates the code at the beginning
1258 * to compute the header length. Since this code generator
1259 * of PPI supports bare 802.11 encapsulation only (i.e.
1260 * the encapsulated DLT should be DLT_IEEE802_11) we
1261 * generate code to check for this too.
1263 cstate->off_linktype.constant_part = 24;
1264 cstate->off_linkpl.constant_part = 0; /* link-layer header is variable-length */
1265 cstate->off_linkpl.is_variable = 1;
1266 cstate->off_linkhdr.is_variable = 1;
1267 cstate->off_nl = 8; /* 802.2+SNAP */
1268 cstate->off_nl_nosnap = 3; /* 802.2 */
1271 case DLT_ATM_RFC1483:
1272 case DLT_ATM_CLIP: /* Linux ATM defines this */
1274 * assume routed, non-ISO PDUs
1275 * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00)
1277 * XXX - what about ISO PDUs, e.g. CLNP, ISIS, ESIS,
1278 * or PPP with the PPP NLPID (e.g., PPPoA)? The
1279 * latter would presumably be treated the way PPPoE
1280 * should be, so you can do "pppoe and udp port 2049"
1281 * or "pppoa and tcp port 80" and have it check for
1282 * PPPo{A,E} and a PPP protocol of IP and....
1284 cstate->off_linktype.constant_part = 0;
1285 cstate->off_linkpl.constant_part = 0; /* packet begins with LLC header */
1286 cstate->off_nl = 8; /* 802.2+SNAP */
1287 cstate->off_nl_nosnap = 3; /* 802.2 */
1292 * Full Frontal ATM; you get AALn PDUs with an ATM
1296 cstate->off_vpi = SUNATM_VPI_POS;
1297 cstate->off_vci = SUNATM_VCI_POS;
1298 cstate->off_proto = PROTO_POS;
1299 cstate->off_payload = SUNATM_PKT_BEGIN_POS;
1300 cstate->off_linktype.constant_part = cstate->off_payload;
1301 cstate->off_linkpl.constant_part = cstate->off_payload; /* if LLC-encapsulated */
1302 cstate->off_nl = 8; /* 802.2+SNAP */
1303 cstate->off_nl_nosnap = 3; /* 802.2 */
1309 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1310 cstate->off_linkpl.constant_part = 0;
1312 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1315 case DLT_LINUX_SLL: /* fake header for Linux cooked socket */
1316 cstate->off_linktype.constant_part = 14;
1317 cstate->off_linkpl.constant_part = 16;
1319 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1324 * LocalTalk does have a 1-byte type field in the LLAP header,
1325 * but really it just indicates whether there is a "short" or
1326 * "long" DDP packet following.
1328 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1329 cstate->off_linkpl.constant_part = 0;
1331 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1334 case DLT_IP_OVER_FC:
1336 * RFC 2625 IP-over-Fibre-Channel doesn't really have a
1337 * link-level type field. We set "off_linktype" to the
1338 * offset of the LLC header.
1340 * To check for Ethernet types, we assume that SSAP = SNAP
1341 * is being used and pick out the encapsulated Ethernet type.
1342 * XXX - should we generate code to check for SNAP? RFC
1343 * 2625 says SNAP should be used.
1345 cstate->off_linktype.constant_part = 16;
1346 cstate->off_linkpl.constant_part = 16;
1347 cstate->off_nl = 8; /* 802.2+SNAP */
1348 cstate->off_nl_nosnap = 3; /* 802.2 */
1353 * XXX - we should set this to handle SNAP-encapsulated
1354 * frames (NLPID of 0x80).
1356 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1357 cstate->off_linkpl.constant_part = 0;
1359 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1363 * the only BPF-interesting FRF.16 frames are non-control frames;
1364 * Frame Relay has a variable length link-layer
1365 * so lets start with offset 4 for now and increments later on (FIXME);
1368 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1369 cstate->off_linkpl.constant_part = 0;
1371 cstate->off_nl_nosnap = 0; /* XXX - for now -> no 802.2 LLC */
1374 case DLT_APPLE_IP_OVER_IEEE1394:
1375 cstate->off_linktype.constant_part = 16;
1376 cstate->off_linkpl.constant_part = 18;
1378 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1381 case DLT_SYMANTEC_FIREWALL:
1382 cstate->off_linktype.constant_part = 6;
1383 cstate->off_linkpl.constant_part = 44;
1384 cstate->off_nl = 0; /* Ethernet II */
1385 cstate->off_nl_nosnap = 0; /* XXX - what does it do with 802.3 packets? */
1388 #ifdef HAVE_NET_PFVAR_H
1390 cstate->off_linktype.constant_part = 0;
1391 cstate->off_linkpl.constant_part = PFLOG_HDRLEN;
1393 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
1397 case DLT_JUNIPER_MFR:
1398 case DLT_JUNIPER_MLFR:
1399 case DLT_JUNIPER_MLPPP:
1400 case DLT_JUNIPER_PPP:
1401 case DLT_JUNIPER_CHDLC:
1402 case DLT_JUNIPER_FRELAY:
1403 cstate->off_linktype.constant_part = 4;
1404 cstate->off_linkpl.constant_part = 4;
1406 cstate->off_nl_nosnap = -1; /* no 802.2 LLC */
1409 case DLT_JUNIPER_ATM1:
1410 cstate->off_linktype.constant_part = 4; /* in reality variable between 4-8 */
1411 cstate->off_linkpl.constant_part = 4; /* in reality variable between 4-8 */
1413 cstate->off_nl_nosnap = 10;
1416 case DLT_JUNIPER_ATM2:
1417 cstate->off_linktype.constant_part = 8; /* in reality variable between 8-12 */
1418 cstate->off_linkpl.constant_part = 8; /* in reality variable between 8-12 */
1420 cstate->off_nl_nosnap = 10;
1423 /* frames captured on a Juniper PPPoE service PIC
1424 * contain raw ethernet frames */
1425 case DLT_JUNIPER_PPPOE:
1426 case DLT_JUNIPER_ETHER:
1427 cstate->off_linkpl.constant_part = 14;
1428 cstate->off_linktype.constant_part = 16;
1429 cstate->off_nl = 18; /* Ethernet II */
1430 cstate->off_nl_nosnap = 21; /* 802.3+802.2 */
1433 case DLT_JUNIPER_PPPOE_ATM:
1434 cstate->off_linktype.constant_part = 4;
1435 cstate->off_linkpl.constant_part = 6;
1437 cstate->off_nl_nosnap = -1; /* no 802.2 LLC */
1440 case DLT_JUNIPER_GGSN:
1441 cstate->off_linktype.constant_part = 6;
1442 cstate->off_linkpl.constant_part = 12;
1444 cstate->off_nl_nosnap = -1; /* no 802.2 LLC */
1447 case DLT_JUNIPER_ES:
1448 cstate->off_linktype.constant_part = 6;
1449 cstate->off_linkpl.constant_part = OFFSET_NOT_SET; /* not really a network layer but raw IP addresses */
1450 cstate->off_nl = -1; /* not really a network layer but raw IP addresses */
1451 cstate->off_nl_nosnap = -1; /* no 802.2 LLC */
1454 case DLT_JUNIPER_MONITOR:
1455 cstate->off_linktype.constant_part = 12;
1456 cstate->off_linkpl.constant_part = 12;
1457 cstate->off_nl = 0; /* raw IP/IP6 header */
1458 cstate->off_nl_nosnap = -1; /* no 802.2 LLC */
1461 case DLT_BACNET_MS_TP:
1462 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1463 cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
1464 cstate->off_nl = -1;
1465 cstate->off_nl_nosnap = -1;
1468 case DLT_JUNIPER_SERVICES:
1469 cstate->off_linktype.constant_part = 12;
1470 cstate->off_linkpl.constant_part = OFFSET_NOT_SET; /* L3 proto location dep. on cookie type */
1471 cstate->off_nl = -1; /* L3 proto location dep. on cookie type */
1472 cstate->off_nl_nosnap = -1; /* no 802.2 LLC */
1475 case DLT_JUNIPER_VP:
1476 cstate->off_linktype.constant_part = 18;
1477 cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
1478 cstate->off_nl = -1;
1479 cstate->off_nl_nosnap = -1;
1482 case DLT_JUNIPER_ST:
1483 cstate->off_linktype.constant_part = 18;
1484 cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
1485 cstate->off_nl = -1;
1486 cstate->off_nl_nosnap = -1;
1489 case DLT_JUNIPER_ISM:
1490 cstate->off_linktype.constant_part = 8;
1491 cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
1492 cstate->off_nl = -1;
1493 cstate->off_nl_nosnap = -1;
1496 case DLT_JUNIPER_VS:
1497 case DLT_JUNIPER_SRX_E2E:
1498 case DLT_JUNIPER_FIBRECHANNEL:
1499 case DLT_JUNIPER_ATM_CEMIC:
1500 cstate->off_linktype.constant_part = 8;
1501 cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
1502 cstate->off_nl = -1;
1503 cstate->off_nl_nosnap = -1;
1508 cstate->off_li_hsl = 4;
1509 cstate->off_sio = 3;
1510 cstate->off_opc = 4;
1511 cstate->off_dpc = 4;
1512 cstate->off_sls = 7;
1513 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1514 cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
1515 cstate->off_nl = -1;
1516 cstate->off_nl_nosnap = -1;
1519 case DLT_MTP2_WITH_PHDR:
1521 cstate->off_li_hsl = 8;
1522 cstate->off_sio = 7;
1523 cstate->off_opc = 8;
1524 cstate->off_dpc = 8;
1525 cstate->off_sls = 11;
1526 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1527 cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
1528 cstate->off_nl = -1;
1529 cstate->off_nl_nosnap = -1;
1533 cstate->off_li = 22;
1534 cstate->off_li_hsl = 24;
1535 cstate->off_sio = 23;
1536 cstate->off_opc = 24;
1537 cstate->off_dpc = 24;
1538 cstate->off_sls = 27;
1539 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1540 cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
1541 cstate->off_nl = -1;
1542 cstate->off_nl_nosnap = -1;
1546 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1547 cstate->off_linkpl.constant_part = 4;
1549 cstate->off_nl_nosnap = 0;
1554 * Currently, only raw "link[N:M]" filtering is supported.
1556 cstate->off_linktype.constant_part = OFFSET_NOT_SET; /* variable, min 15, max 71 steps of 7 */
1557 cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
1558 cstate->off_nl = -1; /* variable, min 16, max 71 steps of 7 */
1559 cstate->off_nl_nosnap = -1; /* no 802.2 LLC */
1563 cstate->off_linktype.constant_part = 1;
1564 cstate->off_linkpl.constant_part = 24; /* ipnet header length */
1566 cstate->off_nl_nosnap = -1;
1569 case DLT_NETANALYZER:
1570 cstate->off_linkhdr.constant_part = 4; /* Ethernet header is past 4-byte pseudo-header */
1571 cstate->off_linktype.constant_part = cstate->off_linkhdr.constant_part + 12;
1572 cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 14; /* pseudo-header+Ethernet header length */
1573 cstate->off_nl = 0; /* Ethernet II */
1574 cstate->off_nl_nosnap = 3; /* 802.3+802.2 */
1577 case DLT_NETANALYZER_TRANSPARENT:
1578 cstate->off_linkhdr.constant_part = 12; /* MAC header is past 4-byte pseudo-header, preamble, and SFD */
1579 cstate->off_linktype.constant_part = cstate->off_linkhdr.constant_part + 12;
1580 cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 14; /* pseudo-header+preamble+SFD+Ethernet header length */
1581 cstate->off_nl = 0; /* Ethernet II */
1582 cstate->off_nl_nosnap = 3; /* 802.3+802.2 */
1587 * For values in the range in which we've assigned new
1588 * DLT_ values, only raw "link[N:M]" filtering is supported.
1590 if (cstate->linktype >= DLT_MATCHING_MIN &&
1591 cstate->linktype <= DLT_MATCHING_MAX) {
1592 cstate->off_linktype.constant_part = OFFSET_NOT_SET;
1593 cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
1594 cstate->off_nl = -1;
1595 cstate->off_nl_nosnap = -1;
1597 bpf_error(cstate, "unknown data link type %d", cstate->linktype);
1602 cstate->off_outermostlinkhdr = cstate->off_prevlinkhdr = cstate->off_linkhdr;
1606 * Load a value relative to the specified absolute offset.
1608 static struct slist *
1609 gen_load_absoffsetrel(compiler_state_t *cstate, bpf_abs_offset *abs_offset,
1610 u_int offset, u_int size)
1612 struct slist *s, *s2;
1614 s = gen_abs_offset_varpart(cstate, abs_offset);
1617 * If "s" is non-null, it has code to arrange that the X register
1618 * contains the variable part of the absolute offset, so we
1619 * generate a load relative to that, with an offset of
1620 * abs_offset->constant_part + offset.
1622 * Otherwise, we can do an absolute load with an offset of
1623 * abs_offset->constant_part + offset.
1627 * "s" points to a list of statements that puts the
1628 * variable part of the absolute offset into the X register.
1629 * Do an indirect load, to use the X register as an offset.
1631 s2 = new_stmt(cstate, BPF_LD|BPF_IND|size);
1632 s2->s.k = abs_offset->constant_part + offset;
1636 * There is no variable part of the absolute offset, so
1637 * just do an absolute load.
1639 s = new_stmt(cstate, BPF_LD|BPF_ABS|size);
1640 s->s.k = abs_offset->constant_part + offset;
1646 * Load a value relative to the beginning of the specified header.
1648 static struct slist *
1649 gen_load_a(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
1652 struct slist *s, *s2;
1657 s = new_stmt(cstate, BPF_LD|BPF_ABS|size);
1662 s = gen_load_absoffsetrel(cstate, &cstate->off_linkhdr, offset, size);
1665 case OR_PREVLINKHDR:
1666 s = gen_load_absoffsetrel(cstate, &cstate->off_prevlinkhdr, offset, size);
1670 s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, offset, size);
1673 case OR_PREVMPLSHDR:
1674 s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl - 4 + offset, size);
1678 s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl + offset, size);
1681 case OR_LINKPL_NOSNAP:
1682 s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl_nosnap + offset, size);
1686 s = gen_load_absoffsetrel(cstate, &cstate->off_linktype, offset, size);
1691 * Load the X register with the length of the IPv4 header
1692 * (plus the offset of the link-layer header, if it's
1693 * preceded by a variable-length header such as a radio
1694 * header), in bytes.
1696 s = gen_loadx_iphdrlen(cstate);
1699 * Load the item at {offset of the link-layer payload} +
1700 * {offset, relative to the start of the link-layer
1701 * paylod, of the IPv4 header} + {length of the IPv4 header} +
1702 * {specified offset}.
1704 * If the offset of the link-layer payload is variable,
1705 * the variable part of that offset is included in the
1706 * value in the X register, and we include the constant
1707 * part in the offset of the load.
1709 s2 = new_stmt(cstate, BPF_LD|BPF_IND|size);
1710 s2->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + offset;
1715 s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl + 40 + offset, size);
1726 * Generate code to load into the X register the sum of the length of
1727 * the IPv4 header and the variable part of the offset of the link-layer
1730 static struct slist *
1731 gen_loadx_iphdrlen(compiler_state_t *cstate)
1733 struct slist *s, *s2;
1735 s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl);
1738 * The offset of the link-layer payload has a variable
1739 * part. "s" points to a list of statements that put
1740 * the variable part of that offset into the X register.
1742 * The 4*([k]&0xf) addressing mode can't be used, as we
1743 * don't have a constant offset, so we have to load the
1744 * value in question into the A register and add to it
1745 * the value from the X register.
1747 s2 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
1748 s2->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
1750 s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
1753 s2 = new_stmt(cstate, BPF_ALU|BPF_LSH|BPF_K);
1758 * The A register now contains the length of the IP header.
1759 * We need to add to it the variable part of the offset of
1760 * the link-layer payload, which is still in the X
1761 * register, and move the result into the X register.
1763 sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X));
1764 sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX));
1767 * The offset of the link-layer payload is a constant,
1768 * so no code was generated to load the (non-existent)
1769 * variable part of that offset.
1771 * This means we can use the 4*([k]&0xf) addressing
1772 * mode. Load the length of the IPv4 header, which
1773 * is at an offset of cstate->off_nl from the beginning of
1774 * the link-layer payload, and thus at an offset of
1775 * cstate->off_linkpl.constant_part + cstate->off_nl from the beginning
1776 * of the raw packet data, using that addressing mode.
1778 s = new_stmt(cstate, BPF_LDX|BPF_MSH|BPF_B);
1779 s->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
1784 static struct block *
1785 gen_uncond(compiler_state_t *cstate, int rsense)
1790 s = new_stmt(cstate, BPF_LD|BPF_IMM);
1792 b = new_block(cstate, JMP(BPF_JEQ));
1798 static inline struct block *
1799 gen_true(compiler_state_t *cstate)
1801 return gen_uncond(cstate, 1);
1804 static inline struct block *
1805 gen_false(compiler_state_t *cstate)
1807 return gen_uncond(cstate, 0);
1811 * Byte-swap a 32-bit number.
1812 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on
1813 * big-endian platforms.)
1815 #define SWAPLONG(y) \
1816 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
1819 * Generate code to match a particular packet type.
1821 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
1822 * value, if <= ETHERMTU. We use that to determine whether to
1823 * match the type/length field or to check the type/length field for
1824 * a value <= ETHERMTU to see whether it's a type field and then do
1825 * the appropriate test.
1827 static struct block *
1828 gen_ether_linktype(compiler_state_t *cstate, int proto)
1830 struct block *b0, *b1;
1836 case LLCSAP_NETBEUI:
1838 * OSI protocols and NetBEUI always use 802.2 encapsulation,
1839 * so we check the DSAP and SSAP.
1841 * LLCSAP_IP checks for IP-over-802.2, rather
1842 * than IP-over-Ethernet or IP-over-SNAP.
1844 * XXX - should we check both the DSAP and the
1845 * SSAP, like this, or should we check just the
1846 * DSAP, as we do for other types <= ETHERMTU
1847 * (i.e., other SAP values)?
1849 b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU);
1851 b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32)
1852 ((proto << 8) | proto));
1860 * Ethernet_II frames, which are Ethernet
1861 * frames with a frame type of ETHERTYPE_IPX;
1863 * Ethernet_802.3 frames, which are 802.3
1864 * frames (i.e., the type/length field is
1865 * a length field, <= ETHERMTU, rather than
1866 * a type field) with the first two bytes
1867 * after the Ethernet/802.3 header being
1870 * Ethernet_802.2 frames, which are 802.3
1871 * frames with an 802.2 LLC header and
1872 * with the IPX LSAP as the DSAP in the LLC
1875 * Ethernet_SNAP frames, which are 802.3
1876 * frames with an LLC header and a SNAP
1877 * header and with an OUI of 0x000000
1878 * (encapsulated Ethernet) and a protocol
1879 * ID of ETHERTYPE_IPX in the SNAP header.
1881 * XXX - should we generate the same code both
1882 * for tests for LLCSAP_IPX and for ETHERTYPE_IPX?
1886 * This generates code to check both for the
1887 * IPX LSAP (Ethernet_802.2) and for Ethernet_802.3.
1889 b0 = gen_cmp(cstate, OR_LLC, 0, BPF_B, (bpf_int32)LLCSAP_IPX);
1890 b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32)0xFFFF);
1894 * Now we add code to check for SNAP frames with
1895 * ETHERTYPE_IPX, i.e. Ethernet_SNAP.
1897 b0 = gen_snap(cstate, 0x000000, ETHERTYPE_IPX);
1901 * Now we generate code to check for 802.3
1902 * frames in general.
1904 b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU);
1908 * Now add the check for 802.3 frames before the
1909 * check for Ethernet_802.2 and Ethernet_802.3,
1910 * as those checks should only be done on 802.3
1911 * frames, not on Ethernet frames.
1916 * Now add the check for Ethernet_II frames, and
1917 * do that before checking for the other frame
1920 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)ETHERTYPE_IPX);
1924 case ETHERTYPE_ATALK:
1925 case ETHERTYPE_AARP:
1927 * EtherTalk (AppleTalk protocols on Ethernet link
1928 * layer) may use 802.2 encapsulation.
1932 * Check for 802.2 encapsulation (EtherTalk phase 2?);
1933 * we check for an Ethernet type field less than
1934 * 1500, which means it's an 802.3 length field.
1936 b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU);
1940 * 802.2-encapsulated ETHERTYPE_ATALK packets are
1941 * SNAP packets with an organization code of
1942 * 0x080007 (Apple, for Appletalk) and a protocol
1943 * type of ETHERTYPE_ATALK (Appletalk).
1945 * 802.2-encapsulated ETHERTYPE_AARP packets are
1946 * SNAP packets with an organization code of
1947 * 0x000000 (encapsulated Ethernet) and a protocol
1948 * type of ETHERTYPE_AARP (Appletalk ARP).
1950 if (proto == ETHERTYPE_ATALK)
1951 b1 = gen_snap(cstate, 0x080007, ETHERTYPE_ATALK);
1952 else /* proto == ETHERTYPE_AARP */
1953 b1 = gen_snap(cstate, 0x000000, ETHERTYPE_AARP);
1957 * Check for Ethernet encapsulation (Ethertalk
1958 * phase 1?); we just check for the Ethernet
1961 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
1967 if (proto <= ETHERMTU) {
1969 * This is an LLC SAP value, so the frames
1970 * that match would be 802.2 frames.
1971 * Check that the frame is an 802.2 frame
1972 * (i.e., that the length/type field is
1973 * a length field, <= ETHERMTU) and
1974 * then check the DSAP.
1976 b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU);
1978 b1 = gen_cmp(cstate, OR_LINKTYPE, 2, BPF_B, (bpf_int32)proto);
1983 * This is an Ethernet type, so compare
1984 * the length/type field with it (if
1985 * the frame is an 802.2 frame, the length
1986 * field will be <= ETHERMTU, and, as
1987 * "proto" is > ETHERMTU, this test
1988 * will fail and the frame won't match,
1989 * which is what we want).
1991 return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H,
1997 static struct block *
1998 gen_loopback_linktype(compiler_state_t *cstate, int proto)
2001 * For DLT_NULL, the link-layer header is a 32-bit word
2002 * containing an AF_ value in *host* byte order, and for
2003 * DLT_ENC, the link-layer header begins with a 32-bit
2004 * word containing an AF_ value in host byte order.
2006 * In addition, if we're reading a saved capture file,
2007 * the host byte order in the capture may not be the
2008 * same as the host byte order on this machine.
2010 * For DLT_LOOP, the link-layer header is a 32-bit
2011 * word containing an AF_ value in *network* byte order.
2013 if (cstate->linktype == DLT_NULL || cstate->linktype == DLT_ENC) {
2015 * The AF_ value is in host byte order, but the BPF
2016 * interpreter will convert it to network byte order.
2018 * If this is a save file, and it's from a machine
2019 * with the opposite byte order to ours, we byte-swap
2022 * Then we run it through "htonl()", and generate
2023 * code to compare against the result.
2025 if (cstate->bpf_pcap->rfile != NULL && cstate->bpf_pcap->swapped)
2026 proto = SWAPLONG(proto);
2027 proto = htonl(proto);
2029 return (gen_cmp(cstate, OR_LINKHDR, 0, BPF_W, (bpf_int32)proto));
2033 * "proto" is an Ethernet type value and for IPNET, if it is not IPv4
2034 * or IPv6 then we have an error.
2036 static struct block *
2037 gen_ipnet_linktype(compiler_state_t *cstate, int proto)
2042 return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, (bpf_int32)IPH_AF_INET);
2045 case ETHERTYPE_IPV6:
2046 return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
2047 (bpf_int32)IPH_AF_INET6);
2054 return gen_false(cstate);
2058 * Generate code to match a particular packet type.
2060 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
2061 * value, if <= ETHERMTU. We use that to determine whether to
2062 * match the type field or to check the type field for the special
2063 * LINUX_SLL_P_802_2 value and then do the appropriate test.
2065 static struct block *
2066 gen_linux_sll_linktype(compiler_state_t *cstate, int proto)
2068 struct block *b0, *b1;
2074 case LLCSAP_NETBEUI:
2076 * OSI protocols and NetBEUI always use 802.2 encapsulation,
2077 * so we check the DSAP and SSAP.
2079 * LLCSAP_IP checks for IP-over-802.2, rather
2080 * than IP-over-Ethernet or IP-over-SNAP.
2082 * XXX - should we check both the DSAP and the
2083 * SSAP, like this, or should we check just the
2084 * DSAP, as we do for other types <= ETHERMTU
2085 * (i.e., other SAP values)?
2087 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
2088 b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32)
2089 ((proto << 8) | proto));
2095 * Ethernet_II frames, which are Ethernet
2096 * frames with a frame type of ETHERTYPE_IPX;
2098 * Ethernet_802.3 frames, which have a frame
2099 * type of LINUX_SLL_P_802_3;
2101 * Ethernet_802.2 frames, which are 802.3
2102 * frames with an 802.2 LLC header (i.e, have
2103 * a frame type of LINUX_SLL_P_802_2) and
2104 * with the IPX LSAP as the DSAP in the LLC
2107 * Ethernet_SNAP frames, which are 802.3
2108 * frames with an LLC header and a SNAP
2109 * header and with an OUI of 0x000000
2110 * (encapsulated Ethernet) and a protocol
2111 * ID of ETHERTYPE_IPX in the SNAP header.
2113 * First, do the checks on LINUX_SLL_P_802_2
2114 * frames; generate the check for either
2115 * Ethernet_802.2 or Ethernet_SNAP frames, and
2116 * then put a check for LINUX_SLL_P_802_2 frames
2119 b0 = gen_cmp(cstate, OR_LLC, 0, BPF_B, (bpf_int32)LLCSAP_IPX);
2120 b1 = gen_snap(cstate, 0x000000, ETHERTYPE_IPX);
2122 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
2126 * Now check for 802.3 frames and OR that with
2127 * the previous test.
2129 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_3);
2133 * Now add the check for Ethernet_II frames, and
2134 * do that before checking for the other frame
2137 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)ETHERTYPE_IPX);
2141 case ETHERTYPE_ATALK:
2142 case ETHERTYPE_AARP:
2144 * EtherTalk (AppleTalk protocols on Ethernet link
2145 * layer) may use 802.2 encapsulation.
2149 * Check for 802.2 encapsulation (EtherTalk phase 2?);
2150 * we check for the 802.2 protocol type in the
2151 * "Ethernet type" field.
2153 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
2156 * 802.2-encapsulated ETHERTYPE_ATALK packets are
2157 * SNAP packets with an organization code of
2158 * 0x080007 (Apple, for Appletalk) and a protocol
2159 * type of ETHERTYPE_ATALK (Appletalk).
2161 * 802.2-encapsulated ETHERTYPE_AARP packets are
2162 * SNAP packets with an organization code of
2163 * 0x000000 (encapsulated Ethernet) and a protocol
2164 * type of ETHERTYPE_AARP (Appletalk ARP).
2166 if (proto == ETHERTYPE_ATALK)
2167 b1 = gen_snap(cstate, 0x080007, ETHERTYPE_ATALK);
2168 else /* proto == ETHERTYPE_AARP */
2169 b1 = gen_snap(cstate, 0x000000, ETHERTYPE_AARP);
2173 * Check for Ethernet encapsulation (Ethertalk
2174 * phase 1?); we just check for the Ethernet
2177 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
2183 if (proto <= ETHERMTU) {
2185 * This is an LLC SAP value, so the frames
2186 * that match would be 802.2 frames.
2187 * Check for the 802.2 protocol type
2188 * in the "Ethernet type" field, and
2189 * then check the DSAP.
2191 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
2192 b1 = gen_cmp(cstate, OR_LINKHDR, cstate->off_linkpl.constant_part, BPF_B,
2198 * This is an Ethernet type, so compare
2199 * the length/type field with it (if
2200 * the frame is an 802.2 frame, the length
2201 * field will be <= ETHERMTU, and, as
2202 * "proto" is > ETHERMTU, this test
2203 * will fail and the frame won't match,
2204 * which is what we want).
2206 return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
2211 static struct slist *
2212 gen_load_prism_llprefixlen(compiler_state_t *cstate)
2214 struct slist *s1, *s2;
2215 struct slist *sjeq_avs_cookie;
2216 struct slist *sjcommon;
2219 * This code is not compatible with the optimizer, as
2220 * we are generating jmp instructions within a normal
2221 * slist of instructions
2223 cstate->no_optimize = 1;
2226 * Generate code to load the length of the radio header into
2227 * the register assigned to hold that length, if one has been
2228 * assigned. (If one hasn't been assigned, no code we've
2229 * generated uses that prefix, so we don't need to generate any
2232 * Some Linux drivers use ARPHRD_IEEE80211_PRISM but sometimes
2233 * or always use the AVS header rather than the Prism header.
2234 * We load a 4-byte big-endian value at the beginning of the
2235 * raw packet data, and see whether, when masked with 0xFFFFF000,
2236 * it's equal to 0x80211000. If so, that indicates that it's
2237 * an AVS header (the masked-out bits are the version number).
2238 * Otherwise, it's a Prism header.
2240 * XXX - the Prism header is also, in theory, variable-length,
2241 * but no known software generates headers that aren't 144
2244 if (cstate->off_linkhdr.reg != -1) {
2248 s1 = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS);
2252 * AND it with 0xFFFFF000.
2254 s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
2255 s2->s.k = 0xFFFFF000;
2259 * Compare with 0x80211000.
2261 sjeq_avs_cookie = new_stmt(cstate, JMP(BPF_JEQ));
2262 sjeq_avs_cookie->s.k = 0x80211000;
2263 sappend(s1, sjeq_avs_cookie);
2268 * The 4 bytes at an offset of 4 from the beginning of
2269 * the AVS header are the length of the AVS header.
2270 * That field is big-endian.
2272 s2 = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS);
2275 sjeq_avs_cookie->s.jt = s2;
2278 * Now jump to the code to allocate a register
2279 * into which to save the header length and
2280 * store the length there. (The "jump always"
2281 * instruction needs to have the k field set;
2282 * it's added to the PC, so, as we're jumping
2283 * over a single instruction, it should be 1.)
2285 sjcommon = new_stmt(cstate, JMP(BPF_JA));
2287 sappend(s1, sjcommon);
2290 * Now for the code that handles the Prism header.
2291 * Just load the length of the Prism header (144)
2292 * into the A register. Have the test for an AVS
2293 * header branch here if we don't have an AVS header.
2295 s2 = new_stmt(cstate, BPF_LD|BPF_W|BPF_IMM);
2298 sjeq_avs_cookie->s.jf = s2;
2301 * Now allocate a register to hold that value and store
2302 * it. The code for the AVS header will jump here after
2303 * loading the length of the AVS header.
2305 s2 = new_stmt(cstate, BPF_ST);
2306 s2->s.k = cstate->off_linkhdr.reg;
2308 sjcommon->s.jf = s2;
2311 * Now move it into the X register.
2313 s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
2321 static struct slist *
2322 gen_load_avs_llprefixlen(compiler_state_t *cstate)
2324 struct slist *s1, *s2;
2327 * Generate code to load the length of the AVS header into
2328 * the register assigned to hold that length, if one has been
2329 * assigned. (If one hasn't been assigned, no code we've
2330 * generated uses that prefix, so we don't need to generate any
2333 if (cstate->off_linkhdr.reg != -1) {
2335 * The 4 bytes at an offset of 4 from the beginning of
2336 * the AVS header are the length of the AVS header.
2337 * That field is big-endian.
2339 s1 = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS);
2343 * Now allocate a register to hold that value and store
2346 s2 = new_stmt(cstate, BPF_ST);
2347 s2->s.k = cstate->off_linkhdr.reg;
2351 * Now move it into the X register.
2353 s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
2361 static struct slist *
2362 gen_load_radiotap_llprefixlen(compiler_state_t *cstate)
2364 struct slist *s1, *s2;
2367 * Generate code to load the length of the radiotap header into
2368 * the register assigned to hold that length, if one has been
2369 * assigned. (If one hasn't been assigned, no code we've
2370 * generated uses that prefix, so we don't need to generate any
2373 if (cstate->off_linkhdr.reg != -1) {
2375 * The 2 bytes at offsets of 2 and 3 from the beginning
2376 * of the radiotap header are the length of the radiotap
2377 * header; unfortunately, it's little-endian, so we have
2378 * to load it a byte at a time and construct the value.
2382 * Load the high-order byte, at an offset of 3, shift it
2383 * left a byte, and put the result in the X register.
2385 s1 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
2387 s2 = new_stmt(cstate, BPF_ALU|BPF_LSH|BPF_K);
2390 s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
2394 * Load the next byte, at an offset of 2, and OR the
2395 * value from the X register into it.
2397 s2 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
2400 s2 = new_stmt(cstate, BPF_ALU|BPF_OR|BPF_X);
2404 * Now allocate a register to hold that value and store
2407 s2 = new_stmt(cstate, BPF_ST);
2408 s2->s.k = cstate->off_linkhdr.reg;
2412 * Now move it into the X register.
2414 s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
2423 * At the moment we treat PPI as normal Radiotap encoded
2424 * packets. The difference is in the function that generates
2425 * the code at the beginning to compute the header length.
2426 * Since this code generator of PPI supports bare 802.11
2427 * encapsulation only (i.e. the encapsulated DLT should be
2428 * DLT_IEEE802_11) we generate code to check for this too;
2429 * that's done in finish_parse().
2431 static struct slist *
2432 gen_load_ppi_llprefixlen(compiler_state_t *cstate)
2434 struct slist *s1, *s2;
2437 * Generate code to load the length of the radiotap header
2438 * into the register assigned to hold that length, if one has
2441 if (cstate->off_linkhdr.reg != -1) {
2443 * The 2 bytes at offsets of 2 and 3 from the beginning
2444 * of the radiotap header are the length of the radiotap
2445 * header; unfortunately, it's little-endian, so we have
2446 * to load it a byte at a time and construct the value.
2450 * Load the high-order byte, at an offset of 3, shift it
2451 * left a byte, and put the result in the X register.
2453 s1 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
2455 s2 = new_stmt(cstate, BPF_ALU|BPF_LSH|BPF_K);
2458 s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
2462 * Load the next byte, at an offset of 2, and OR the
2463 * value from the X register into it.
2465 s2 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
2468 s2 = new_stmt(cstate, BPF_ALU|BPF_OR|BPF_X);
2472 * Now allocate a register to hold that value and store
2475 s2 = new_stmt(cstate, BPF_ST);
2476 s2->s.k = cstate->off_linkhdr.reg;
2480 * Now move it into the X register.
2482 s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
2491 * Load a value relative to the beginning of the link-layer header after the 802.11
2492 * header, i.e. LLC_SNAP.
2493 * The link-layer header doesn't necessarily begin at the beginning
2494 * of the packet data; there might be a variable-length prefix containing
2495 * radio information.
2497 static struct slist *
2498 gen_load_802_11_header_len(compiler_state_t *cstate, struct slist *s, struct slist *snext)
2501 struct slist *sjset_data_frame_1;
2502 struct slist *sjset_data_frame_2;
2503 struct slist *sjset_qos;
2504 struct slist *sjset_radiotap_flags_present;
2505 struct slist *sjset_radiotap_ext_present;
2506 struct slist *sjset_radiotap_tsft_present;
2507 struct slist *sjset_tsft_datapad, *sjset_notsft_datapad;
2508 struct slist *s_roundup;
2510 if (cstate->off_linkpl.reg == -1) {
2512 * No register has been assigned to the offset of
2513 * the link-layer payload, which means nobody needs
2514 * it; don't bother computing it - just return
2515 * what we already have.
2521 * This code is not compatible with the optimizer, as
2522 * we are generating jmp instructions within a normal
2523 * slist of instructions
2525 cstate->no_optimize = 1;
2528 * If "s" is non-null, it has code to arrange that the X register
2529 * contains the length of the prefix preceding the link-layer
2532 * Otherwise, the length of the prefix preceding the link-layer
2533 * header is "off_outermostlinkhdr.constant_part".
2537 * There is no variable-length header preceding the
2538 * link-layer header.
2540 * Load the length of the fixed-length prefix preceding
2541 * the link-layer header (if any) into the X register,
2542 * and store it in the cstate->off_linkpl.reg register.
2543 * That length is off_outermostlinkhdr.constant_part.
2545 s = new_stmt(cstate, BPF_LDX|BPF_IMM);
2546 s->s.k = cstate->off_outermostlinkhdr.constant_part;
2550 * The X register contains the offset of the beginning of the
2551 * link-layer header; add 24, which is the minimum length
2552 * of the MAC header for a data frame, to that, and store it
2553 * in cstate->off_linkpl.reg, and then load the Frame Control field,
2554 * which is at the offset in the X register, with an indexed load.
2556 s2 = new_stmt(cstate, BPF_MISC|BPF_TXA);
2558 s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
2561 s2 = new_stmt(cstate, BPF_ST);
2562 s2->s.k = cstate->off_linkpl.reg;
2565 s2 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
2570 * Check the Frame Control field to see if this is a data frame;
2571 * a data frame has the 0x08 bit (b3) in that field set and the
2572 * 0x04 bit (b2) clear.
2574 sjset_data_frame_1 = new_stmt(cstate, JMP(BPF_JSET));
2575 sjset_data_frame_1->s.k = 0x08;
2576 sappend(s, sjset_data_frame_1);
2579 * If b3 is set, test b2, otherwise go to the first statement of
2580 * the rest of the program.
2582 sjset_data_frame_1->s.jt = sjset_data_frame_2 = new_stmt(cstate, JMP(BPF_JSET));
2583 sjset_data_frame_2->s.k = 0x04;
2584 sappend(s, sjset_data_frame_2);
2585 sjset_data_frame_1->s.jf = snext;
2588 * If b2 is not set, this is a data frame; test the QoS bit.
2589 * Otherwise, go to the first statement of the rest of the
2592 sjset_data_frame_2->s.jt = snext;
2593 sjset_data_frame_2->s.jf = sjset_qos = new_stmt(cstate, JMP(BPF_JSET));
2594 sjset_qos->s.k = 0x80; /* QoS bit */
2595 sappend(s, sjset_qos);
2598 * If it's set, add 2 to cstate->off_linkpl.reg, to skip the QoS
2600 * Otherwise, go to the first statement of the rest of the
2603 sjset_qos->s.jt = s2 = new_stmt(cstate, BPF_LD|BPF_MEM);
2604 s2->s.k = cstate->off_linkpl.reg;
2606 s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_IMM);
2609 s2 = new_stmt(cstate, BPF_ST);
2610 s2->s.k = cstate->off_linkpl.reg;
2614 * If we have a radiotap header, look at it to see whether
2615 * there's Atheros padding between the MAC-layer header
2618 * Note: all of the fields in the radiotap header are
2619 * little-endian, so we byte-swap all of the values
2620 * we test against, as they will be loaded as big-endian
2623 * XXX - in the general case, we would have to scan through
2624 * *all* the presence bits, if there's more than one word of
2625 * presence bits. That would require a loop, meaning that
2626 * we wouldn't be able to run the filter in the kernel.
2628 * We assume here that the Atheros adapters that insert the
2629 * annoying padding don't have multiple antennae and therefore
2630 * do not generate radiotap headers with multiple presence words.
2632 if (cstate->linktype == DLT_IEEE802_11_RADIO) {
2634 * Is the IEEE80211_RADIOTAP_FLAGS bit (0x0000002) set
2635 * in the first presence flag word?
2637 sjset_qos->s.jf = s2 = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_W);
2641 sjset_radiotap_flags_present = new_stmt(cstate, JMP(BPF_JSET));
2642 sjset_radiotap_flags_present->s.k = SWAPLONG(0x00000002);
2643 sappend(s, sjset_radiotap_flags_present);
2646 * If not, skip all of this.
2648 sjset_radiotap_flags_present->s.jf = snext;
2651 * Otherwise, is the "extension" bit set in that word?
2653 sjset_radiotap_ext_present = new_stmt(cstate, JMP(BPF_JSET));
2654 sjset_radiotap_ext_present->s.k = SWAPLONG(0x80000000);
2655 sappend(s, sjset_radiotap_ext_present);
2656 sjset_radiotap_flags_present->s.jt = sjset_radiotap_ext_present;
2659 * If so, skip all of this.
2661 sjset_radiotap_ext_present->s.jt = snext;
2664 * Otherwise, is the IEEE80211_RADIOTAP_TSFT bit set?
2666 sjset_radiotap_tsft_present = new_stmt(cstate, JMP(BPF_JSET));
2667 sjset_radiotap_tsft_present->s.k = SWAPLONG(0x00000001);
2668 sappend(s, sjset_radiotap_tsft_present);
2669 sjset_radiotap_ext_present->s.jf = sjset_radiotap_tsft_present;
2672 * If IEEE80211_RADIOTAP_TSFT is set, the flags field is
2673 * at an offset of 16 from the beginning of the raw packet
2674 * data (8 bytes for the radiotap header and 8 bytes for
2677 * Test whether the IEEE80211_RADIOTAP_F_DATAPAD bit (0x20)
2680 s2 = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B);
2683 sjset_radiotap_tsft_present->s.jt = s2;
2685 sjset_tsft_datapad = new_stmt(cstate, JMP(BPF_JSET));
2686 sjset_tsft_datapad->s.k = 0x20;
2687 sappend(s, sjset_tsft_datapad);
2690 * If IEEE80211_RADIOTAP_TSFT is not set, the flags field is
2691 * at an offset of 8 from the beginning of the raw packet
2692 * data (8 bytes for the radiotap header).
2694 * Test whether the IEEE80211_RADIOTAP_F_DATAPAD bit (0x20)
2697 s2 = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B);
2700 sjset_radiotap_tsft_present->s.jf = s2;
2702 sjset_notsft_datapad = new_stmt(cstate, JMP(BPF_JSET));
2703 sjset_notsft_datapad->s.k = 0x20;
2704 sappend(s, sjset_notsft_datapad);
2707 * In either case, if IEEE80211_RADIOTAP_F_DATAPAD is
2708 * set, round the length of the 802.11 header to
2709 * a multiple of 4. Do that by adding 3 and then
2710 * dividing by and multiplying by 4, which we do by
2713 s_roundup = new_stmt(cstate, BPF_LD|BPF_MEM);
2714 s_roundup->s.k = cstate->off_linkpl.reg;
2715 sappend(s, s_roundup);
2716 s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_IMM);
2719 s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_IMM);
2722 s2 = new_stmt(cstate, BPF_ST);
2723 s2->s.k = cstate->off_linkpl.reg;
2726 sjset_tsft_datapad->s.jt = s_roundup;
2727 sjset_tsft_datapad->s.jf = snext;
2728 sjset_notsft_datapad->s.jt = s_roundup;
2729 sjset_notsft_datapad->s.jf = snext;
2731 sjset_qos->s.jf = snext;
2737 insert_compute_vloffsets(compiler_state_t *cstate, struct block *b)
2741 /* There is an implicit dependency between the link
2742 * payload and link header since the payload computation
2743 * includes the variable part of the header. Therefore,
2744 * if nobody else has allocated a register for the link
2745 * header and we need it, do it now. */
2746 if (cstate->off_linkpl.reg != -1 && cstate->off_linkhdr.is_variable &&
2747 cstate->off_linkhdr.reg == -1)
2748 cstate->off_linkhdr.reg = alloc_reg(cstate);
2751 * For link-layer types that have a variable-length header
2752 * preceding the link-layer header, generate code to load
2753 * the offset of the link-layer header into the register
2754 * assigned to that offset, if any.
2756 * XXX - this, and the next switch statement, won't handle
2757 * encapsulation of 802.11 or 802.11+radio information in
2758 * some other protocol stack. That's significantly more
2761 switch (cstate->outermostlinktype) {
2763 case DLT_PRISM_HEADER:
2764 s = gen_load_prism_llprefixlen(cstate);
2767 case DLT_IEEE802_11_RADIO_AVS:
2768 s = gen_load_avs_llprefixlen(cstate);
2771 case DLT_IEEE802_11_RADIO:
2772 s = gen_load_radiotap_llprefixlen(cstate);
2776 s = gen_load_ppi_llprefixlen(cstate);
2785 * For link-layer types that have a variable-length link-layer
2786 * header, generate code to load the offset of the link-layer
2787 * payload into the register assigned to that offset, if any.
2789 switch (cstate->outermostlinktype) {
2791 case DLT_IEEE802_11:
2792 case DLT_PRISM_HEADER:
2793 case DLT_IEEE802_11_RADIO_AVS:
2794 case DLT_IEEE802_11_RADIO:
2796 s = gen_load_802_11_header_len(cstate, s, b->stmts);
2801 * If we have any offset-loading code, append all the
2802 * existing statements in the block to those statements,
2803 * and make the resulting list the list of statements
2807 sappend(s, b->stmts);
2812 static struct block *
2813 gen_ppi_dlt_check(compiler_state_t *cstate)
2815 struct slist *s_load_dlt;
2818 if (cstate->linktype == DLT_PPI)
2820 /* Create the statements that check for the DLT
2822 s_load_dlt = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS);
2823 s_load_dlt->s.k = 4;
2825 b = new_block(cstate, JMP(BPF_JEQ));
2827 b->stmts = s_load_dlt;
2828 b->s.k = SWAPLONG(DLT_IEEE802_11);
2839 * Take an absolute offset, and:
2841 * if it has no variable part, return NULL;
2843 * if it has a variable part, generate code to load the register
2844 * containing that variable part into the X register, returning
2845 * a pointer to that code - if no register for that offset has
2846 * been allocated, allocate it first.
2848 * (The code to set that register will be generated later, but will
2849 * be placed earlier in the code sequence.)
2851 static struct slist *
2852 gen_abs_offset_varpart(compiler_state_t *cstate, bpf_abs_offset *off)
2856 if (off->is_variable) {
2857 if (off->reg == -1) {
2859 * We haven't yet assigned a register for the
2860 * variable part of the offset of the link-layer
2861 * header; allocate one.
2863 off->reg = alloc_reg(cstate);
2867 * Load the register containing the variable part of the
2868 * offset of the link-layer header into the X register.
2870 s = new_stmt(cstate, BPF_LDX|BPF_MEM);
2875 * That offset isn't variable, there's no variable part,
2876 * so we don't need to generate any code.
2883 * Map an Ethernet type to the equivalent PPP type.
2886 ethertype_to_ppptype(proto)
2895 case ETHERTYPE_IPV6:
2903 case ETHERTYPE_ATALK:
2917 * I'm assuming the "Bridging PDU"s that go
2918 * over PPP are Spanning Tree Protocol
2932 * Generate any tests that, for encapsulation of a link-layer packet
2933 * inside another protocol stack, need to be done to check for those
2934 * link-layer packets (and that haven't already been done by a check
2935 * for that encapsulation).
2937 static struct block *
2938 gen_prevlinkhdr_check(compiler_state_t *cstate)
2942 if (cstate->is_geneve)
2943 return gen_geneve_ll_check(cstate);
2945 switch (cstate->prevlinktype) {
2949 * This is LANE-encapsulated Ethernet; check that the LANE
2950 * packet doesn't begin with an LE Control marker, i.e.
2951 * that it's data, not a control message.
2953 * (We've already generated a test for LANE.)
2955 b0 = gen_cmp(cstate, OR_PREVLINKHDR, SUNATM_PKT_BEGIN_POS, BPF_H, 0xFF00);
2961 * No such tests are necessary.
2969 * The three different values we should check for when checking for an
2970 * IPv6 packet with DLT_NULL.
2972 #define BSD_AFNUM_INET6_BSD 24 /* NetBSD, OpenBSD, BSD/OS, Npcap */
2973 #define BSD_AFNUM_INET6_FREEBSD 28 /* FreeBSD */
2974 #define BSD_AFNUM_INET6_DARWIN 30 /* OS X, iOS, other Darwin-based OSes */
2977 * Generate code to match a particular packet type by matching the
2978 * link-layer type field or fields in the 802.2 LLC header.
2980 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
2981 * value, if <= ETHERMTU.
2983 static struct block *
2984 gen_linktype(compiler_state_t *cstate, int proto)
2986 struct block *b0, *b1, *b2;
2987 const char *description;
2989 /* are we checking MPLS-encapsulated packets? */
2990 if (cstate->label_stack_depth > 0) {
2994 /* FIXME add other L3 proto IDs */
2995 return gen_mpls_linktype(cstate, Q_IP);
2997 case ETHERTYPE_IPV6:
2999 /* FIXME add other L3 proto IDs */
3000 return gen_mpls_linktype(cstate, Q_IPV6);
3003 bpf_error(cstate, "unsupported protocol over mpls");
3008 switch (cstate->linktype) {
3011 case DLT_NETANALYZER:
3012 case DLT_NETANALYZER_TRANSPARENT:
3013 /* Geneve has an EtherType regardless of whether there is an
3015 if (!cstate->is_geneve)
3016 b0 = gen_prevlinkhdr_check(cstate);
3020 b1 = gen_ether_linktype(cstate, proto);
3031 proto = (proto << 8 | LLCSAP_ISONS);
3035 return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
3041 case DLT_IEEE802_11:
3042 case DLT_PRISM_HEADER:
3043 case DLT_IEEE802_11_RADIO_AVS:
3044 case DLT_IEEE802_11_RADIO:
3047 * Check that we have a data frame.
3049 b0 = gen_check_802_11_data_frame(cstate);
3052 * Now check for the specified link-layer type.
3054 b1 = gen_llc_linktype(cstate, proto);
3062 * XXX - check for LLC frames.
3064 return gen_llc_linktype(cstate, proto);
3070 * XXX - check for LLC PDUs, as per IEEE 802.5.
3072 return gen_llc_linktype(cstate, proto);
3076 case DLT_ATM_RFC1483:
3078 case DLT_IP_OVER_FC:
3079 return gen_llc_linktype(cstate, proto);
3085 * Check for an LLC-encapsulated version of this protocol;
3086 * if we were checking for LANE, linktype would no longer
3089 * Check for LLC encapsulation and then check the protocol.
3091 b0 = gen_atmfield_code(cstate, A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
3092 b1 = gen_llc_linktype(cstate, proto);
3099 return gen_linux_sll_linktype(cstate, proto);
3104 case DLT_SLIP_BSDOS:
3107 * These types don't provide any type field; packets
3108 * are always IPv4 or IPv6.
3110 * XXX - for IPv4, check for a version number of 4, and,
3111 * for IPv6, check for a version number of 6?
3116 /* Check for a version number of 4. */
3117 return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, 0x40, 0xF0);
3119 case ETHERTYPE_IPV6:
3120 /* Check for a version number of 6. */
3121 return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, 0x60, 0xF0);
3124 return gen_false(cstate); /* always false */
3131 * Raw IPv4, so no type field.
3133 if (proto == ETHERTYPE_IP)
3134 return gen_true(cstate); /* always true */
3136 /* Checking for something other than IPv4; always false */
3137 return gen_false(cstate);
3143 * Raw IPv6, so no type field.
3145 if (proto == ETHERTYPE_IPV6)
3146 return gen_true(cstate); /* always true */
3148 /* Checking for something other than IPv6; always false */
3149 return gen_false(cstate);
3155 case DLT_PPP_SERIAL:
3158 * We use Ethernet protocol types inside libpcap;
3159 * map them to the corresponding PPP protocol types.
3161 proto = ethertype_to_ppptype(proto);
3162 return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
3168 * We use Ethernet protocol types inside libpcap;
3169 * map them to the corresponding PPP protocol types.
3175 * Also check for Van Jacobson-compressed IP.
3176 * XXX - do this for other forms of PPP?
3178 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_IP);
3179 b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_VJC);
3181 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_VJNC);
3186 proto = ethertype_to_ppptype(proto);
3187 return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H,
3199 return (gen_loopback_linktype(cstate, AF_INET));
3201 case ETHERTYPE_IPV6:
3203 * AF_ values may, unfortunately, be platform-
3204 * dependent; AF_INET isn't, because everybody
3205 * used 4.2BSD's value, but AF_INET6 is, because
3206 * 4.2BSD didn't have a value for it (given that
3207 * IPv6 didn't exist back in the early 1980's),
3208 * and they all picked their own values.
3210 * This means that, if we're reading from a
3211 * savefile, we need to check for all the
3214 * If we're doing a live capture, we only need
3215 * to check for this platform's value; however,
3216 * Npcap uses 24, which isn't Windows's AF_INET6
3217 * value. (Given the multiple different values,
3218 * programs that read pcap files shouldn't be
3219 * checking for their platform's AF_INET6 value
3220 * anyway, they should check for all of the
3221 * possible values. and they might as well do
3222 * that even for live captures.)
3224 if (cstate->bpf_pcap->rfile != NULL) {
3226 * Savefile - check for all three
3227 * possible IPv6 values.
3229 b0 = gen_loopback_linktype(cstate, BSD_AFNUM_INET6_BSD);
3230 b1 = gen_loopback_linktype(cstate, BSD_AFNUM_INET6_FREEBSD);
3232 b0 = gen_loopback_linktype(cstate, BSD_AFNUM_INET6_DARWIN);
3237 * Live capture, so we only need to
3238 * check for the value used on this
3243 * Npcap doesn't use Windows's AF_INET6,
3244 * as that collides with AF_IPX on
3245 * some BSDs (both have the value 23).
3246 * Instead, it uses 24.
3248 return (gen_loopback_linktype(cstate, 24));
3251 return (gen_loopback_linktype(cstate, AF_INET6));
3252 #else /* AF_INET6 */
3254 * I guess this platform doesn't support
3255 * IPv6, so we just reject all packets.
3257 return gen_false(cstate);
3258 #endif /* AF_INET6 */
3264 * Not a type on which we support filtering.
3265 * XXX - support those that have AF_ values
3266 * #defined on this platform, at least?
3268 return gen_false(cstate);
3271 #ifdef HAVE_NET_PFVAR_H
3274 * af field is host byte order in contrast to the rest of
3277 if (proto == ETHERTYPE_IP)
3278 return (gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, af),
3279 BPF_B, (bpf_int32)AF_INET));
3280 else if (proto == ETHERTYPE_IPV6)
3281 return (gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, af),
3282 BPF_B, (bpf_int32)AF_INET6));
3284 return gen_false(cstate);
3287 #endif /* HAVE_NET_PFVAR_H */
3290 case DLT_ARCNET_LINUX:
3292 * XXX should we check for first fragment if the protocol
3298 return gen_false(cstate);
3300 case ETHERTYPE_IPV6:
3301 return (gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
3302 (bpf_int32)ARCTYPE_INET6));
3305 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
3306 (bpf_int32)ARCTYPE_IP);
3307 b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
3308 (bpf_int32)ARCTYPE_IP_OLD);
3313 b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
3314 (bpf_int32)ARCTYPE_ARP);
3315 b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
3316 (bpf_int32)ARCTYPE_ARP_OLD);
3320 case ETHERTYPE_REVARP:
3321 return (gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
3322 (bpf_int32)ARCTYPE_REVARP));
3324 case ETHERTYPE_ATALK:
3325 return (gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
3326 (bpf_int32)ARCTYPE_ATALK));
3333 case ETHERTYPE_ATALK:
3334 return gen_true(cstate);
3336 return gen_false(cstate);
3343 * XXX - assumes a 2-byte Frame Relay header with
3344 * DLCI and flags. What if the address is longer?
3350 * Check for the special NLPID for IP.
3352 return gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | 0xcc);
3354 case ETHERTYPE_IPV6:
3356 * Check for the special NLPID for IPv6.
3358 return gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | 0x8e);
3362 * Check for several OSI protocols.
3364 * Frame Relay packets typically have an OSI
3365 * NLPID at the beginning; we check for each
3368 * What we check for is the NLPID and a frame
3369 * control field of UI, i.e. 0x03 followed
3372 b0 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO8473_CLNP);
3373 b1 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO9542_ESIS);
3374 b2 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO10589_ISIS);
3380 return gen_false(cstate);
3386 bpf_error(cstate, "Multi-link Frame Relay link-layer type filtering not implemented");
3388 case DLT_JUNIPER_MFR:
3389 case DLT_JUNIPER_MLFR:
3390 case DLT_JUNIPER_MLPPP:
3391 case DLT_JUNIPER_ATM1:
3392 case DLT_JUNIPER_ATM2:
3393 case DLT_JUNIPER_PPPOE:
3394 case DLT_JUNIPER_PPPOE_ATM:
3395 case DLT_JUNIPER_GGSN:
3396 case DLT_JUNIPER_ES:
3397 case DLT_JUNIPER_MONITOR:
3398 case DLT_JUNIPER_SERVICES:
3399 case DLT_JUNIPER_ETHER:
3400 case DLT_JUNIPER_PPP:
3401 case DLT_JUNIPER_FRELAY:
3402 case DLT_JUNIPER_CHDLC:
3403 case DLT_JUNIPER_VP:
3404 case DLT_JUNIPER_ST:
3405 case DLT_JUNIPER_ISM:
3406 case DLT_JUNIPER_VS:
3407 case DLT_JUNIPER_SRX_E2E:
3408 case DLT_JUNIPER_FIBRECHANNEL:
3409 case DLT_JUNIPER_ATM_CEMIC:
3411 /* just lets verify the magic number for now -
3412 * on ATM we may have up to 6 different encapsulations on the wire
3413 * and need a lot of heuristics to figure out that the payload
3416 * FIXME encapsulation specific BPF_ filters
3418 return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_W, 0x4d474300, 0xffffff00); /* compare the magic number */
3420 case DLT_BACNET_MS_TP:
3421 return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_W, 0x55FF0000, 0xffff0000);
3424 return gen_ipnet_linktype(cstate, proto);
3426 case DLT_LINUX_IRDA:
3427 bpf_error(cstate, "IrDA link-layer type filtering not implemented");
3430 bpf_error(cstate, "DOCSIS link-layer type filtering not implemented");
3433 case DLT_MTP2_WITH_PHDR:
3434 bpf_error(cstate, "MTP2 link-layer type filtering not implemented");
3437 bpf_error(cstate, "ERF link-layer type filtering not implemented");
3440 bpf_error(cstate, "PFSYNC link-layer type filtering not implemented");
3442 case DLT_LINUX_LAPD:
3443 bpf_error(cstate, "LAPD link-layer type filtering not implemented");
3445 case DLT_USB_FREEBSD:
3447 case DLT_USB_LINUX_MMAPPED:
3449 bpf_error(cstate, "USB link-layer type filtering not implemented");
3451 case DLT_BLUETOOTH_HCI_H4:
3452 case DLT_BLUETOOTH_HCI_H4_WITH_PHDR:
3453 bpf_error(cstate, "Bluetooth link-layer type filtering not implemented");
3456 case DLT_CAN_SOCKETCAN:
3457 bpf_error(cstate, "CAN link-layer type filtering not implemented");
3459 case DLT_IEEE802_15_4:
3460 case DLT_IEEE802_15_4_LINUX:
3461 case DLT_IEEE802_15_4_NONASK_PHY:
3462 case DLT_IEEE802_15_4_NOFCS:
3463 bpf_error(cstate, "IEEE 802.15.4 link-layer type filtering not implemented");
3465 case DLT_IEEE802_16_MAC_CPS_RADIO:
3466 bpf_error(cstate, "IEEE 802.16 link-layer type filtering not implemented");
3469 bpf_error(cstate, "SITA link-layer type filtering not implemented");
3472 bpf_error(cstate, "RAIF1 link-layer type filtering not implemented");
3475 bpf_error(cstate, "IPMB link-layer type filtering not implemented");
3478 bpf_error(cstate, "AX.25 link-layer type filtering not implemented");
3481 /* Using the fixed-size NFLOG header it is possible to tell only
3482 * the address family of the packet, other meaningful data is
3483 * either missing or behind TLVs.
3485 bpf_error(cstate, "NFLOG link-layer type filtering not implemented");
3489 * Does this link-layer header type have a field
3490 * indicating the type of the next protocol? If
3491 * so, off_linktype.constant_part will be the offset of that
3492 * field in the packet; if not, it will be OFFSET_NOT_SET.
3494 if (cstate->off_linktype.constant_part != OFFSET_NOT_SET) {
3496 * Yes; assume it's an Ethernet type. (If
3497 * it's not, it needs to be handled specially
3500 return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
3503 * No; report an error.
3505 description = pcap_datalink_val_to_description(cstate->linktype);
3506 if (description != NULL) {
3507 bpf_error(cstate, "%s link-layer type filtering not implemented",
3510 bpf_error(cstate, "DLT %u link-layer type filtering not implemented",
3519 * Check for an LLC SNAP packet with a given organization code and
3520 * protocol type; we check the entire contents of the 802.2 LLC and
3521 * snap headers, checking for DSAP and SSAP of SNAP and a control
3522 * field of 0x03 in the LLC header, and for the specified organization
3523 * code and protocol type in the SNAP header.
3525 static struct block *
3526 gen_snap(compiler_state_t *cstate, bpf_u_int32 orgcode, bpf_u_int32 ptype)
3528 u_char snapblock[8];
3530 snapblock[0] = LLCSAP_SNAP; /* DSAP = SNAP */
3531 snapblock[1] = LLCSAP_SNAP; /* SSAP = SNAP */
3532 snapblock[2] = 0x03; /* control = UI */
3533 snapblock[3] = (orgcode >> 16); /* upper 8 bits of organization code */
3534 snapblock[4] = (orgcode >> 8); /* middle 8 bits of organization code */
3535 snapblock[5] = (orgcode >> 0); /* lower 8 bits of organization code */
3536 snapblock[6] = (ptype >> 8); /* upper 8 bits of protocol type */
3537 snapblock[7] = (ptype >> 0); /* lower 8 bits of protocol type */
3538 return gen_bcmp(cstate, OR_LLC, 0, 8, snapblock);
3542 * Generate code to match frames with an LLC header.
3545 gen_llc(compiler_state_t *cstate)
3547 struct block *b0, *b1;
3549 switch (cstate->linktype) {
3553 * We check for an Ethernet type field less than
3554 * 1500, which means it's an 802.3 length field.
3556 b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU);
3560 * Now check for the purported DSAP and SSAP not being
3561 * 0xFF, to rule out NetWare-over-802.3.
3563 b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32)0xFFFF);
3570 * We check for LLC traffic.
3572 b0 = gen_atmtype_abbrev(cstate, A_LLC);
3575 case DLT_IEEE802: /* Token Ring */
3577 * XXX - check for LLC frames.
3579 return gen_true(cstate);
3583 * XXX - check for LLC frames.
3585 return gen_true(cstate);
3587 case DLT_ATM_RFC1483:
3589 * For LLC encapsulation, these are defined to have an
3592 * For VC encapsulation, they don't, but there's no
3593 * way to check for that; the protocol used on the VC
3594 * is negotiated out of band.
3596 return gen_true(cstate);
3598 case DLT_IEEE802_11:
3599 case DLT_PRISM_HEADER:
3600 case DLT_IEEE802_11_RADIO:
3601 case DLT_IEEE802_11_RADIO_AVS:
3604 * Check that we have a data frame.
3606 b0 = gen_check_802_11_data_frame(cstate);
3610 bpf_error(cstate, "'llc' not supported for linktype %d", cstate->linktype);
3616 gen_llc_i(compiler_state_t *cstate)
3618 struct block *b0, *b1;
3622 * Check whether this is an LLC frame.
3624 b0 = gen_llc(cstate);
3627 * Load the control byte and test the low-order bit; it must
3628 * be clear for I frames.
3630 s = gen_load_a(cstate, OR_LLC, 2, BPF_B);
3631 b1 = new_block(cstate, JMP(BPF_JSET));
3640 gen_llc_s(compiler_state_t *cstate)
3642 struct block *b0, *b1;
3645 * Check whether this is an LLC frame.
3647 b0 = gen_llc(cstate);
3650 * Now compare the low-order 2 bit of the control byte against
3651 * the appropriate value for S frames.
3653 b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, LLC_S_FMT, 0x03);
3659 gen_llc_u(compiler_state_t *cstate)
3661 struct block *b0, *b1;
3664 * Check whether this is an LLC frame.
3666 b0 = gen_llc(cstate);
3669 * Now compare the low-order 2 bit of the control byte against
3670 * the appropriate value for U frames.
3672 b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, LLC_U_FMT, 0x03);
3678 gen_llc_s_subtype(compiler_state_t *cstate, bpf_u_int32 subtype)
3680 struct block *b0, *b1;
3683 * Check whether this is an LLC frame.
3685 b0 = gen_llc(cstate);
3688 * Now check for an S frame with the appropriate type.
3690 b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, subtype, LLC_S_CMD_MASK);
3696 gen_llc_u_subtype(compiler_state_t *cstate, bpf_u_int32 subtype)
3698 struct block *b0, *b1;
3701 * Check whether this is an LLC frame.
3703 b0 = gen_llc(cstate);
3706 * Now check for a U frame with the appropriate type.
3708 b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, subtype, LLC_U_CMD_MASK);
3714 * Generate code to match a particular packet type, for link-layer types
3715 * using 802.2 LLC headers.
3717 * This is *NOT* used for Ethernet; "gen_ether_linktype()" is used
3718 * for that - it handles the D/I/X Ethernet vs. 802.3+802.2 issues.
3720 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
3721 * value, if <= ETHERMTU. We use that to determine whether to
3722 * match the DSAP or both DSAP and LSAP or to check the OUI and
3723 * protocol ID in a SNAP header.
3725 static struct block *
3726 gen_llc_linktype(compiler_state_t *cstate, int proto)
3729 * XXX - handle token-ring variable-length header.
3735 case LLCSAP_NETBEUI:
3737 * XXX - should we check both the DSAP and the
3738 * SSAP, like this, or should we check just the
3739 * DSAP, as we do for other SAP values?
3741 return gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_u_int32)
3742 ((proto << 8) | proto));
3746 * XXX - are there ever SNAP frames for IPX on
3747 * non-Ethernet 802.x networks?
3749 return gen_cmp(cstate, OR_LLC, 0, BPF_B,
3750 (bpf_int32)LLCSAP_IPX);
3752 case ETHERTYPE_ATALK:
3754 * 802.2-encapsulated ETHERTYPE_ATALK packets are
3755 * SNAP packets with an organization code of
3756 * 0x080007 (Apple, for Appletalk) and a protocol
3757 * type of ETHERTYPE_ATALK (Appletalk).
3759 * XXX - check for an organization code of
3760 * encapsulated Ethernet as well?
3762 return gen_snap(cstate, 0x080007, ETHERTYPE_ATALK);
3766 * XXX - we don't have to check for IPX 802.3
3767 * here, but should we check for the IPX Ethertype?
3769 if (proto <= ETHERMTU) {
3771 * This is an LLC SAP value, so check
3774 return gen_cmp(cstate, OR_LLC, 0, BPF_B, (bpf_int32)proto);
3777 * This is an Ethernet type; we assume that it's
3778 * unlikely that it'll appear in the right place
3779 * at random, and therefore check only the
3780 * location that would hold the Ethernet type
3781 * in a SNAP frame with an organization code of
3782 * 0x000000 (encapsulated Ethernet).
3784 * XXX - if we were to check for the SNAP DSAP and
3785 * LSAP, as per XXX, and were also to check for an
3786 * organization code of 0x000000 (encapsulated
3787 * Ethernet), we'd do
3789 * return gen_snap(cstate, 0x000000, proto);
3791 * here; for now, we don't, as per the above.
3792 * I don't know whether it's worth the extra CPU
3793 * time to do the right check or not.
3795 return gen_cmp(cstate, OR_LLC, 6, BPF_H, (bpf_int32)proto);
3800 static struct block *
3801 gen_hostop(compiler_state_t *cstate, bpf_u_int32 addr, bpf_u_int32 mask,
3802 int dir, int proto, u_int src_off, u_int dst_off)
3804 struct block *b0, *b1;
3818 b0 = gen_hostop(cstate, addr, mask, Q_SRC, proto, src_off, dst_off);
3819 b1 = gen_hostop(cstate, addr, mask, Q_DST, proto, src_off, dst_off);
3825 b0 = gen_hostop(cstate, addr, mask, Q_SRC, proto, src_off, dst_off);
3826 b1 = gen_hostop(cstate, addr, mask, Q_DST, proto, src_off, dst_off);
3833 b0 = gen_linktype(cstate, proto);
3834 b1 = gen_mcmp(cstate, OR_LINKPL, offset, BPF_W, (bpf_int32)addr, mask);
3840 static struct block *
3841 gen_hostop6(compiler_state_t *cstate, struct in6_addr *addr,
3842 struct in6_addr *mask, int dir, int proto, u_int src_off, u_int dst_off)
3844 struct block *b0, *b1;
3859 b0 = gen_hostop6(cstate, addr, mask, Q_SRC, proto, src_off, dst_off);
3860 b1 = gen_hostop6(cstate, addr, mask, Q_DST, proto, src_off, dst_off);
3866 b0 = gen_hostop6(cstate, addr, mask, Q_SRC, proto, src_off, dst_off);
3867 b1 = gen_hostop6(cstate, addr, mask, Q_DST, proto, src_off, dst_off);
3874 /* this order is important */
3875 a = (u_int32_t *)addr;
3876 m = (u_int32_t *)mask;
3877 b1 = gen_mcmp(cstate, OR_LINKPL, offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3]));
3878 b0 = gen_mcmp(cstate, OR_LINKPL, offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2]));
3880 b0 = gen_mcmp(cstate, OR_LINKPL, offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1]));
3882 b0 = gen_mcmp(cstate, OR_LINKPL, offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0]));
3884 b0 = gen_linktype(cstate, proto);
3890 static struct block *
3891 gen_ehostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
3893 register struct block *b0, *b1;
3897 return gen_bcmp(cstate, OR_LINKHDR, 6, 6, eaddr);
3900 return gen_bcmp(cstate, OR_LINKHDR, 0, 6, eaddr);
3903 b0 = gen_ehostop(cstate, eaddr, Q_SRC);
3904 b1 = gen_ehostop(cstate, eaddr, Q_DST);
3910 b0 = gen_ehostop(cstate, eaddr, Q_SRC);
3911 b1 = gen_ehostop(cstate, eaddr, Q_DST);
3916 bpf_error(cstate, "'addr1' is only supported on 802.11 with 802.11 headers");
3920 bpf_error(cstate, "'addr2' is only supported on 802.11 with 802.11 headers");
3924 bpf_error(cstate, "'addr3' is only supported on 802.11 with 802.11 headers");
3928 bpf_error(cstate, "'addr4' is only supported on 802.11 with 802.11 headers");
3932 bpf_error(cstate, "'ra' is only supported on 802.11 with 802.11 headers");
3936 bpf_error(cstate, "'ta' is only supported on 802.11 with 802.11 headers");
3944 * Like gen_ehostop, but for DLT_FDDI
3946 static struct block *
3947 gen_fhostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
3949 struct block *b0, *b1;
3953 return gen_bcmp(cstate, OR_LINKHDR, 6 + 1 + cstate->pcap_fddipad, 6, eaddr);
3956 return gen_bcmp(cstate, OR_LINKHDR, 0 + 1 + cstate->pcap_fddipad, 6, eaddr);
3959 b0 = gen_fhostop(cstate, eaddr, Q_SRC);
3960 b1 = gen_fhostop(cstate, eaddr, Q_DST);
3966 b0 = gen_fhostop(cstate, eaddr, Q_SRC);
3967 b1 = gen_fhostop(cstate, eaddr, Q_DST);
3972 bpf_error(cstate, "'addr1' is only supported on 802.11");
3976 bpf_error(cstate, "'addr2' is only supported on 802.11");
3980 bpf_error(cstate, "'addr3' is only supported on 802.11");
3984 bpf_error(cstate, "'addr4' is only supported on 802.11");
3988 bpf_error(cstate, "'ra' is only supported on 802.11");
3992 bpf_error(cstate, "'ta' is only supported on 802.11");
4000 * Like gen_ehostop, but for DLT_IEEE802 (Token Ring)
4002 static struct block *
4003 gen_thostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
4005 register struct block *b0, *b1;
4009 return gen_bcmp(cstate, OR_LINKHDR, 8, 6, eaddr);
4012 return gen_bcmp(cstate, OR_LINKHDR, 2, 6, eaddr);
4015 b0 = gen_thostop(cstate, eaddr, Q_SRC);
4016 b1 = gen_thostop(cstate, eaddr, Q_DST);
4022 b0 = gen_thostop(cstate, eaddr, Q_SRC);
4023 b1 = gen_thostop(cstate, eaddr, Q_DST);
4028 bpf_error(cstate, "'addr1' is only supported on 802.11");
4032 bpf_error(cstate, "'addr2' is only supported on 802.11");
4036 bpf_error(cstate, "'addr3' is only supported on 802.11");
4040 bpf_error(cstate, "'addr4' is only supported on 802.11");
4044 bpf_error(cstate, "'ra' is only supported on 802.11");
4048 bpf_error(cstate, "'ta' is only supported on 802.11");
4056 * Like gen_ehostop, but for DLT_IEEE802_11 (802.11 wireless LAN) and
4057 * various 802.11 + radio headers.
4059 static struct block *
4060 gen_wlanhostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
4062 register struct block *b0, *b1, *b2;
4063 register struct slist *s;
4065 #ifdef ENABLE_WLAN_FILTERING_PATCH
4068 * We need to disable the optimizer because the optimizer is buggy
4069 * and wipes out some LD instructions generated by the below
4070 * code to validate the Frame Control bits
4072 cstate->no_optimize = 1;
4073 #endif /* ENABLE_WLAN_FILTERING_PATCH */
4080 * For control frames, there is no SA.
4082 * For management frames, SA is at an
4083 * offset of 10 from the beginning of
4086 * For data frames, SA is at an offset
4087 * of 10 from the beginning of the packet
4088 * if From DS is clear, at an offset of
4089 * 16 from the beginning of the packet
4090 * if From DS is set and To DS is clear,
4091 * and an offset of 24 from the beginning
4092 * of the packet if From DS is set and To DS
4097 * Generate the tests to be done for data frames
4100 * First, check for To DS set, i.e. check "link[1] & 0x01".
4102 s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
4103 b1 = new_block(cstate, JMP(BPF_JSET));
4104 b1->s.k = 0x01; /* To DS */
4108 * If To DS is set, the SA is at 24.
4110 b0 = gen_bcmp(cstate, OR_LINKHDR, 24, 6, eaddr);
4114 * Now, check for To DS not set, i.e. check
4115 * "!(link[1] & 0x01)".
4117 s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
4118 b2 = new_block(cstate, JMP(BPF_JSET));
4119 b2->s.k = 0x01; /* To DS */
4124 * If To DS is not set, the SA is at 16.
4126 b1 = gen_bcmp(cstate, OR_LINKHDR, 16, 6, eaddr);
4130 * Now OR together the last two checks. That gives
4131 * the complete set of checks for data frames with
4137 * Now check for From DS being set, and AND that with
4138 * the ORed-together checks.
4140 s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
4141 b1 = new_block(cstate, JMP(BPF_JSET));
4142 b1->s.k = 0x02; /* From DS */
4147 * Now check for data frames with From DS not set.
4149 s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
4150 b2 = new_block(cstate, JMP(BPF_JSET));
4151 b2->s.k = 0x02; /* From DS */
4156 * If From DS isn't set, the SA is at 10.
4158 b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
4162 * Now OR together the checks for data frames with
4163 * From DS not set and for data frames with From DS
4164 * set; that gives the checks done for data frames.
4169 * Now check for a data frame.
4170 * I.e, check "link[0] & 0x08".
4172 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
4173 b1 = new_block(cstate, JMP(BPF_JSET));
4178 * AND that with the checks done for data frames.
4183 * If the high-order bit of the type value is 0, this
4184 * is a management frame.
4185 * I.e, check "!(link[0] & 0x08)".
4187 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
4188 b2 = new_block(cstate, JMP(BPF_JSET));
4194 * For management frames, the SA is at 10.
4196 b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
4200 * OR that with the checks done for data frames.
4201 * That gives the checks done for management and
4207 * If the low-order bit of the type value is 1,
4208 * this is either a control frame or a frame
4209 * with a reserved type, and thus not a
4212 * I.e., check "!(link[0] & 0x04)".
4214 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
4215 b1 = new_block(cstate, JMP(BPF_JSET));
4221 * AND that with the checks for data and management
4231 * For control frames, there is no DA.
4233 * For management frames, DA is at an
4234 * offset of 4 from the beginning of
4237 * For data frames, DA is at an offset
4238 * of 4 from the beginning of the packet
4239 * if To DS is clear and at an offset of
4240 * 16 from the beginning of the packet
4245 * Generate the tests to be done for data frames.
4247 * First, check for To DS set, i.e. "link[1] & 0x01".
4249 s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
4250 b1 = new_block(cstate, JMP(BPF_JSET));
4251 b1->s.k = 0x01; /* To DS */
4255 * If To DS is set, the DA is at 16.
4257 b0 = gen_bcmp(cstate, OR_LINKHDR, 16, 6, eaddr);
4261 * Now, check for To DS not set, i.e. check
4262 * "!(link[1] & 0x01)".
4264 s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
4265 b2 = new_block(cstate, JMP(BPF_JSET));
4266 b2->s.k = 0x01; /* To DS */
4271 * If To DS is not set, the DA is at 4.
4273 b1 = gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr);
4277 * Now OR together the last two checks. That gives
4278 * the complete set of checks for data frames.
4283 * Now check for a data frame.
4284 * I.e, check "link[0] & 0x08".
4286 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
4287 b1 = new_block(cstate, JMP(BPF_JSET));
4292 * AND that with the checks done for data frames.
4297 * If the high-order bit of the type value is 0, this
4298 * is a management frame.
4299 * I.e, check "!(link[0] & 0x08)".
4301 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
4302 b2 = new_block(cstate, JMP(BPF_JSET));
4308 * For management frames, the DA is at 4.
4310 b1 = gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr);
4314 * OR that with the checks done for data frames.
4315 * That gives the checks done for management and
4321 * If the low-order bit of the type value is 1,
4322 * this is either a control frame or a frame
4323 * with a reserved type, and thus not a
4326 * I.e., check "!(link[0] & 0x04)".
4328 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
4329 b1 = new_block(cstate, JMP(BPF_JSET));
4335 * AND that with the checks for data and management
4343 * Not present in management frames; addr1 in other
4348 * If the high-order bit of the type value is 0, this
4349 * is a management frame.
4350 * I.e, check "(link[0] & 0x08)".
4352 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
4353 b1 = new_block(cstate, JMP(BPF_JSET));
4360 b0 = gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr);
4363 * AND that with the check of addr1.
4370 * Not present in management frames; addr2, if present,
4375 * Not present in CTS or ACK control frames.
4377 b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
4378 IEEE80211_FC0_TYPE_MASK);
4380 b1 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS,
4381 IEEE80211_FC0_SUBTYPE_MASK);
4383 b2 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_ACK,
4384 IEEE80211_FC0_SUBTYPE_MASK);
4390 * If the high-order bit of the type value is 0, this
4391 * is a management frame.
4392 * I.e, check "(link[0] & 0x08)".
4394 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
4395 b1 = new_block(cstate, JMP(BPF_JSET));
4400 * AND that with the check for frames other than
4401 * CTS and ACK frames.
4408 b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
4413 * XXX - add BSSID keyword?
4416 return (gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr));
4420 * Not present in CTS or ACK control frames.
4422 b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
4423 IEEE80211_FC0_TYPE_MASK);
4425 b1 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS,
4426 IEEE80211_FC0_SUBTYPE_MASK);
4428 b2 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_ACK,
4429 IEEE80211_FC0_SUBTYPE_MASK);
4433 b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
4439 * Not present in control frames.
4441 b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
4442 IEEE80211_FC0_TYPE_MASK);
4444 b1 = gen_bcmp(cstate, OR_LINKHDR, 16, 6, eaddr);
4450 * Present only if the direction mask has both "From DS"
4451 * and "To DS" set. Neither control frames nor management
4452 * frames should have both of those set, so we don't
4453 * check the frame type.
4455 b0 = gen_mcmp(cstate, OR_LINKHDR, 1, BPF_B,
4456 IEEE80211_FC1_DIR_DSTODS, IEEE80211_FC1_DIR_MASK);
4457 b1 = gen_bcmp(cstate, OR_LINKHDR, 24, 6, eaddr);
4462 b0 = gen_wlanhostop(cstate, eaddr, Q_SRC);
4463 b1 = gen_wlanhostop(cstate, eaddr, Q_DST);
4469 b0 = gen_wlanhostop(cstate, eaddr, Q_SRC);
4470 b1 = gen_wlanhostop(cstate, eaddr, Q_DST);
4479 * Like gen_ehostop, but for RFC 2625 IP-over-Fibre-Channel.
4480 * (We assume that the addresses are IEEE 48-bit MAC addresses,
4481 * as the RFC states.)
4483 static struct block *
4484 gen_ipfchostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
4486 register struct block *b0, *b1;
4490 return gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
4493 return gen_bcmp(cstate, OR_LINKHDR, 2, 6, eaddr);
4496 b0 = gen_ipfchostop(cstate, eaddr, Q_SRC);
4497 b1 = gen_ipfchostop(cstate, eaddr, Q_DST);
4503 b0 = gen_ipfchostop(cstate, eaddr, Q_SRC);
4504 b1 = gen_ipfchostop(cstate, eaddr, Q_DST);
4509 bpf_error(cstate, "'addr1' is only supported on 802.11");
4513 bpf_error(cstate, "'addr2' is only supported on 802.11");
4517 bpf_error(cstate, "'addr3' is only supported on 802.11");
4521 bpf_error(cstate, "'addr4' is only supported on 802.11");
4525 bpf_error(cstate, "'ra' is only supported on 802.11");
4529 bpf_error(cstate, "'ta' is only supported on 802.11");
4537 * This is quite tricky because there may be pad bytes in front of the
4538 * DECNET header, and then there are two possible data packet formats that
4539 * carry both src and dst addresses, plus 5 packet types in a format that
4540 * carries only the src node, plus 2 types that use a different format and
4541 * also carry just the src node.
4545 * Instead of doing those all right, we just look for data packets with
4546 * 0 or 1 bytes of padding. If you want to look at other packets, that
4547 * will require a lot more hacking.
4549 * To add support for filtering on DECNET "areas" (network numbers)
4550 * one would want to add a "mask" argument to this routine. That would
4551 * make the filter even more inefficient, although one could be clever
4552 * and not generate masking instructions if the mask is 0xFFFF.
4554 static struct block *
4555 gen_dnhostop(compiler_state_t *cstate, bpf_u_int32 addr, int dir)
4557 struct block *b0, *b1, *b2, *tmp;
4558 u_int offset_lh; /* offset if long header is received */
4559 u_int offset_sh; /* offset if short header is received */
4564 offset_sh = 1; /* follows flags */
4565 offset_lh = 7; /* flgs,darea,dsubarea,HIORD */
4569 offset_sh = 3; /* follows flags, dstnode */
4570 offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */
4574 /* Inefficient because we do our Calvinball dance twice */
4575 b0 = gen_dnhostop(cstate, addr, Q_SRC);
4576 b1 = gen_dnhostop(cstate, addr, Q_DST);
4582 /* Inefficient because we do our Calvinball dance twice */
4583 b0 = gen_dnhostop(cstate, addr, Q_SRC);
4584 b1 = gen_dnhostop(cstate, addr, Q_DST);
4589 bpf_error(cstate, "ISO host filtering not implemented");
4594 b0 = gen_linktype(cstate, ETHERTYPE_DN);
4595 /* Check for pad = 1, long header case */
4596 tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_H,
4597 (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF));
4598 b1 = gen_cmp(cstate, OR_LINKPL, 2 + 1 + offset_lh,
4599 BPF_H, (bpf_int32)ntohs((u_short)addr));
4601 /* Check for pad = 0, long header case */
4602 tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7);
4603 b2 = gen_cmp(cstate, OR_LINKPL, 2 + offset_lh, BPF_H, (bpf_int32)ntohs((u_short)addr));
4606 /* Check for pad = 1, short header case */
4607 tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_H,
4608 (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF));
4609 b2 = gen_cmp(cstate, OR_LINKPL, 2 + 1 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
4612 /* Check for pad = 0, short header case */
4613 tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7);
4614 b2 = gen_cmp(cstate, OR_LINKPL, 2 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
4618 /* Combine with test for cstate->linktype */
4624 * Generate a check for IPv4 or IPv6 for MPLS-encapsulated packets;
4625 * test the bottom-of-stack bit, and then check the version number
4626 * field in the IP header.
4628 static struct block *
4629 gen_mpls_linktype(compiler_state_t *cstate, int proto)
4631 struct block *b0, *b1;
4636 /* match the bottom-of-stack bit */
4637 b0 = gen_mcmp(cstate, OR_LINKPL, -2, BPF_B, 0x01, 0x01);
4638 /* match the IPv4 version number */
4639 b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_B, 0x40, 0xf0);
4644 /* match the bottom-of-stack bit */
4645 b0 = gen_mcmp(cstate, OR_LINKPL, -2, BPF_B, 0x01, 0x01);
4646 /* match the IPv4 version number */
4647 b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_B, 0x60, 0xf0);
4656 static struct block *
4657 gen_host(compiler_state_t *cstate, bpf_u_int32 addr, bpf_u_int32 mask,
4658 int proto, int dir, int type)
4660 struct block *b0, *b1;
4661 const char *typestr;
4671 b0 = gen_host(cstate, addr, mask, Q_IP, dir, type);
4673 * Only check for non-IPv4 addresses if we're not
4674 * checking MPLS-encapsulated packets.
4676 if (cstate->label_stack_depth == 0) {
4677 b1 = gen_host(cstate, addr, mask, Q_ARP, dir, type);
4679 b0 = gen_host(cstate, addr, mask, Q_RARP, dir, type);
4685 return gen_hostop(cstate, addr, mask, dir, ETHERTYPE_IP, 12, 16);
4688 return gen_hostop(cstate, addr, mask, dir, ETHERTYPE_REVARP, 14, 24);
4691 return gen_hostop(cstate, addr, mask, dir, ETHERTYPE_ARP, 14, 24);
4694 bpf_error(cstate, "'tcp' modifier applied to %s", typestr);
4697 bpf_error(cstate, "'sctp' modifier applied to %s", typestr);
4700 bpf_error(cstate, "'udp' modifier applied to %s", typestr);
4703 bpf_error(cstate, "'icmp' modifier applied to %s", typestr);
4706 bpf_error(cstate, "'igmp' modifier applied to %s", typestr);
4709 bpf_error(cstate, "'igrp' modifier applied to %s", typestr);
4712 bpf_error(cstate, "'pim' modifier applied to %s", typestr);
4715 bpf_error(cstate, "'vrrp' modifier applied to %s", typestr);
4718 bpf_error(cstate, "'carp' modifier applied to %s", typestr);
4721 bpf_error(cstate, "ATALK host filtering not implemented");
4724 bpf_error(cstate, "AARP host filtering not implemented");
4727 return gen_dnhostop(cstate, addr, dir);
4730 bpf_error(cstate, "SCA host filtering not implemented");
4733 bpf_error(cstate, "LAT host filtering not implemented");
4736 bpf_error(cstate, "MOPDL host filtering not implemented");
4739 bpf_error(cstate, "MOPRC host filtering not implemented");
4742 bpf_error(cstate, "'ip6' modifier applied to ip host");
4745 bpf_error(cstate, "'icmp6' modifier applied to %s", typestr);
4748 bpf_error(cstate, "'ah' modifier applied to %s", typestr);
4751 bpf_error(cstate, "'esp' modifier applied to %s", typestr);
4754 bpf_error(cstate, "ISO host filtering not implemented");
4757 bpf_error(cstate, "'esis' modifier applied to %s", typestr);
4760 bpf_error(cstate, "'isis' modifier applied to %s", typestr);
4763 bpf_error(cstate, "'clnp' modifier applied to %s", typestr);
4766 bpf_error(cstate, "'stp' modifier applied to %s", typestr);
4769 bpf_error(cstate, "IPX host filtering not implemented");
4772 bpf_error(cstate, "'netbeui' modifier applied to %s", typestr);
4775 bpf_error(cstate, "'radio' modifier applied to %s", typestr);
4784 static struct block *
4785 gen_host6(compiler_state_t *cstate, struct in6_addr *addr,
4786 struct in6_addr *mask, int proto, int dir, int type)
4788 const char *typestr;
4798 return gen_host6(cstate, addr, mask, Q_IPV6, dir, type);
4801 bpf_error(cstate, "link-layer modifier applied to ip6 %s", typestr);
4804 bpf_error(cstate, "'ip' modifier applied to ip6 %s", typestr);
4807 bpf_error(cstate, "'rarp' modifier applied to ip6 %s", typestr);
4810 bpf_error(cstate, "'arp' modifier applied to ip6 %s", typestr);
4813 bpf_error(cstate, "'sctp' modifier applied to %s", typestr);
4816 bpf_error(cstate, "'tcp' modifier applied to %s", typestr);
4819 bpf_error(cstate, "'udp' modifier applied to %s", typestr);
4822 bpf_error(cstate, "'icmp' modifier applied to %s", typestr);
4825 bpf_error(cstate, "'igmp' modifier applied to %s", typestr);
4828 bpf_error(cstate, "'igrp' modifier applied to %s", typestr);
4831 bpf_error(cstate, "'pim' modifier applied to %s", typestr);
4834 bpf_error(cstate, "'vrrp' modifier applied to %s", typestr);
4837 bpf_error(cstate, "'carp' modifier applied to %s", typestr);
4840 bpf_error(cstate, "ATALK host filtering not implemented");
4843 bpf_error(cstate, "AARP host filtering not implemented");
4846 bpf_error(cstate, "'decnet' modifier applied to ip6 %s", typestr);
4849 bpf_error(cstate, "SCA host filtering not implemented");
4852 bpf_error(cstate, "LAT host filtering not implemented");
4855 bpf_error(cstate, "MOPDL host filtering not implemented");
4858 bpf_error(cstate, "MOPRC host filtering not implemented");
4861 return gen_hostop6(cstate, addr, mask, dir, ETHERTYPE_IPV6, 8, 24);
4864 bpf_error(cstate, "'icmp6' modifier applied to %s", typestr);
4867 bpf_error(cstate, "'ah' modifier applied to %s", typestr);
4870 bpf_error(cstate, "'esp' modifier applied to %s", typestr);
4873 bpf_error(cstate, "ISO host filtering not implemented");
4876 bpf_error(cstate, "'esis' modifier applied to %s", typestr);
4879 bpf_error(cstate, "'isis' modifier applied to %s", typestr);
4882 bpf_error(cstate, "'clnp' modifier applied to %s", typestr);
4885 bpf_error(cstate, "'stp' modifier applied to %s", typestr);
4888 bpf_error(cstate, "IPX host filtering not implemented");
4891 bpf_error(cstate, "'netbeui' modifier applied to %s", typestr);
4894 bpf_error(cstate, "'radio' modifier applied to %s", typestr);
4904 static struct block *
4905 gen_gateway(eaddr, alist, proto, dir)
4906 const u_char *eaddr;
4907 bpf_u_int32 **alist;
4911 struct block *b0, *b1, *tmp;
4914 bpf_error(cstate, "direction applied to 'gateway'");
4921 switch (cstate->linktype) {
4923 case DLT_NETANALYZER:
4924 case DLT_NETANALYZER_TRANSPARENT:
4925 b1 = gen_prevlinkhdr_check(cstate);
4926 b0 = gen_ehostop(cstate, eaddr, Q_OR);
4931 b0 = gen_fhostop(cstate, eaddr, Q_OR);
4934 b0 = gen_thostop(cstate, eaddr, Q_OR);
4936 case DLT_IEEE802_11:
4937 case DLT_PRISM_HEADER:
4938 case DLT_IEEE802_11_RADIO_AVS:
4939 case DLT_IEEE802_11_RADIO:
4941 b0 = gen_wlanhostop(cstate, eaddr, Q_OR);
4945 * This is LLC-multiplexed traffic; if it were
4946 * LANE, cstate->linktype would have been set to
4950 "'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
4952 case DLT_IP_OVER_FC:
4953 b0 = gen_ipfchostop(cstate, eaddr, Q_OR);
4957 "'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
4959 b1 = gen_host(cstate, **alist++, 0xffffffff, proto, Q_OR, Q_HOST);
4961 tmp = gen_host(cstate, **alist++, 0xffffffff, proto, Q_OR,
4970 bpf_error(cstate, "illegal modifier of 'gateway'");
4976 gen_proto_abbrev(compiler_state_t *cstate, int proto)
4984 b1 = gen_proto(cstate, IPPROTO_SCTP, Q_IP, Q_DEFAULT);
4985 b0 = gen_proto(cstate, IPPROTO_SCTP, Q_IPV6, Q_DEFAULT);
4990 b1 = gen_proto(cstate, IPPROTO_TCP, Q_IP, Q_DEFAULT);
4991 b0 = gen_proto(cstate, IPPROTO_TCP, Q_IPV6, Q_DEFAULT);
4996 b1 = gen_proto(cstate, IPPROTO_UDP, Q_IP, Q_DEFAULT);
4997 b0 = gen_proto(cstate, IPPROTO_UDP, Q_IPV6, Q_DEFAULT);
5002 b1 = gen_proto(cstate, IPPROTO_ICMP, Q_IP, Q_DEFAULT);
5005 #ifndef IPPROTO_IGMP
5006 #define IPPROTO_IGMP 2
5010 b1 = gen_proto(cstate, IPPROTO_IGMP, Q_IP, Q_DEFAULT);
5013 #ifndef IPPROTO_IGRP
5014 #define IPPROTO_IGRP 9
5017 b1 = gen_proto(cstate, IPPROTO_IGRP, Q_IP, Q_DEFAULT);
5021 #define IPPROTO_PIM 103
5025 b1 = gen_proto(cstate, IPPROTO_PIM, Q_IP, Q_DEFAULT);
5026 b0 = gen_proto(cstate, IPPROTO_PIM, Q_IPV6, Q_DEFAULT);
5030 #ifndef IPPROTO_VRRP
5031 #define IPPROTO_VRRP 112
5035 b1 = gen_proto(cstate, IPPROTO_VRRP, Q_IP, Q_DEFAULT);
5038 #ifndef IPPROTO_CARP
5039 #define IPPROTO_CARP 112
5043 b1 = gen_proto(cstate, IPPROTO_CARP, Q_IP, Q_DEFAULT);
5047 b1 = gen_linktype(cstate, ETHERTYPE_IP);
5051 b1 = gen_linktype(cstate, ETHERTYPE_ARP);
5055 b1 = gen_linktype(cstate, ETHERTYPE_REVARP);
5059 bpf_error(cstate, "link layer applied in wrong context");
5062 b1 = gen_linktype(cstate, ETHERTYPE_ATALK);
5066 b1 = gen_linktype(cstate, ETHERTYPE_AARP);
5070 b1 = gen_linktype(cstate, ETHERTYPE_DN);
5074 b1 = gen_linktype(cstate, ETHERTYPE_SCA);
5078 b1 = gen_linktype(cstate, ETHERTYPE_LAT);
5082 b1 = gen_linktype(cstate, ETHERTYPE_MOPDL);
5086 b1 = gen_linktype(cstate, ETHERTYPE_MOPRC);
5090 b1 = gen_linktype(cstate, ETHERTYPE_IPV6);
5093 #ifndef IPPROTO_ICMPV6
5094 #define IPPROTO_ICMPV6 58
5097 b1 = gen_proto(cstate, IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT);
5101 #define IPPROTO_AH 51
5104 b1 = gen_proto(cstate, IPPROTO_AH, Q_IP, Q_DEFAULT);
5105 b0 = gen_proto(cstate, IPPROTO_AH, Q_IPV6, Q_DEFAULT);
5110 #define IPPROTO_ESP 50
5113 b1 = gen_proto(cstate, IPPROTO_ESP, Q_IP, Q_DEFAULT);
5114 b0 = gen_proto(cstate, IPPROTO_ESP, Q_IPV6, Q_DEFAULT);
5119 b1 = gen_linktype(cstate, LLCSAP_ISONS);
5123 b1 = gen_proto(cstate, ISO9542_ESIS, Q_ISO, Q_DEFAULT);
5127 b1 = gen_proto(cstate, ISO10589_ISIS, Q_ISO, Q_DEFAULT);
5130 case Q_ISIS_L1: /* all IS-IS Level1 PDU-Types */
5131 b0 = gen_proto(cstate, ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT);
5132 b1 = gen_proto(cstate, ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */
5134 b0 = gen_proto(cstate, ISIS_L1_LSP, Q_ISIS, Q_DEFAULT);
5136 b0 = gen_proto(cstate, ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
5138 b0 = gen_proto(cstate, ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
5142 case Q_ISIS_L2: /* all IS-IS Level2 PDU-Types */
5143 b0 = gen_proto(cstate, ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT);
5144 b1 = gen_proto(cstate, ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */
5146 b0 = gen_proto(cstate, ISIS_L2_LSP, Q_ISIS, Q_DEFAULT);
5148 b0 = gen_proto(cstate, ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
5150 b0 = gen_proto(cstate, ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
5154 case Q_ISIS_IIH: /* all IS-IS Hello PDU-Types */
5155 b0 = gen_proto(cstate, ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT);
5156 b1 = gen_proto(cstate, ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT);
5158 b0 = gen_proto(cstate, ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT);
5163 b0 = gen_proto(cstate, ISIS_L1_LSP, Q_ISIS, Q_DEFAULT);
5164 b1 = gen_proto(cstate, ISIS_L2_LSP, Q_ISIS, Q_DEFAULT);
5169 b0 = gen_proto(cstate, ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
5170 b1 = gen_proto(cstate, ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
5172 b0 = gen_proto(cstate, ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
5174 b0 = gen_proto(cstate, ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
5179 b0 = gen_proto(cstate, ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
5180 b1 = gen_proto(cstate, ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
5185 b0 = gen_proto(cstate, ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
5186 b1 = gen_proto(cstate, ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
5191 b1 = gen_proto(cstate, ISO8473_CLNP, Q_ISO, Q_DEFAULT);
5195 b1 = gen_linktype(cstate, LLCSAP_8021D);
5199 b1 = gen_linktype(cstate, LLCSAP_IPX);
5203 b1 = gen_linktype(cstate, LLCSAP_NETBEUI);
5207 bpf_error(cstate, "'radio' is not a valid protocol type");
5215 static struct block *
5216 gen_ipfrag(compiler_state_t *cstate)
5221 /* not IPv4 frag other than the first frag */
5222 s = gen_load_a(cstate, OR_LINKPL, 6, BPF_H);
5223 b = new_block(cstate, JMP(BPF_JSET));
5232 * Generate a comparison to a port value in the transport-layer header
5233 * at the specified offset from the beginning of that header.
5235 * XXX - this handles a variable-length prefix preceding the link-layer
5236 * header, such as the radiotap or AVS radio prefix, but doesn't handle
5237 * variable-length link-layer headers (such as Token Ring or 802.11
5240 static struct block *
5241 gen_portatom(compiler_state_t *cstate, int off, bpf_int32 v)
5243 return gen_cmp(cstate, OR_TRAN_IPV4, off, BPF_H, v);
5246 static struct block *
5247 gen_portatom6(compiler_state_t *cstate, int off, bpf_int32 v)
5249 return gen_cmp(cstate, OR_TRAN_IPV6, off, BPF_H, v);
5253 gen_portop(compiler_state_t *cstate, int port, int proto, int dir)
5255 struct block *b0, *b1, *tmp;
5257 /* ip proto 'proto' and not a fragment other than the first fragment */
5258 tmp = gen_cmp(cstate, OR_LINKPL, 9, BPF_B, (bpf_int32)proto);
5259 b0 = gen_ipfrag(cstate);
5264 b1 = gen_portatom(cstate, 0, (bpf_int32)port);
5268 b1 = gen_portatom(cstate, 2, (bpf_int32)port);
5273 tmp = gen_portatom(cstate, 0, (bpf_int32)port);
5274 b1 = gen_portatom(cstate, 2, (bpf_int32)port);
5279 tmp = gen_portatom(cstate, 0, (bpf_int32)port);
5280 b1 = gen_portatom(cstate, 2, (bpf_int32)port);
5292 static struct block *
5293 gen_port(compiler_state_t *cstate, int port, int ip_proto, int dir)
5295 struct block *b0, *b1, *tmp;
5300 * For FDDI, RFC 1188 says that SNAP encapsulation is used,
5301 * not LLC encapsulation with LLCSAP_IP.
5303 * For IEEE 802 networks - which includes 802.5 token ring
5304 * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042
5305 * says that SNAP encapsulation is used, not LLC encapsulation
5308 * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and
5309 * RFC 2225 say that SNAP encapsulation is used, not LLC
5310 * encapsulation with LLCSAP_IP.
5312 * So we always check for ETHERTYPE_IP.
5314 b0 = gen_linktype(cstate, ETHERTYPE_IP);
5320 b1 = gen_portop(cstate, port, ip_proto, dir);
5324 tmp = gen_portop(cstate, port, IPPROTO_TCP, dir);
5325 b1 = gen_portop(cstate, port, IPPROTO_UDP, dir);
5327 tmp = gen_portop(cstate, port, IPPROTO_SCTP, dir);
5339 gen_portop6(compiler_state_t *cstate, int port, int proto, int dir)
5341 struct block *b0, *b1, *tmp;
5343 /* ip6 proto 'proto' */
5344 /* XXX - catch the first fragment of a fragmented packet? */
5345 b0 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, (bpf_int32)proto);
5349 b1 = gen_portatom6(cstate, 0, (bpf_int32)port);
5353 b1 = gen_portatom6(cstate, 2, (bpf_int32)port);
5358 tmp = gen_portatom6(cstate, 0, (bpf_int32)port);
5359 b1 = gen_portatom6(cstate, 2, (bpf_int32)port);
5364 tmp = gen_portatom6(cstate, 0, (bpf_int32)port);
5365 b1 = gen_portatom6(cstate, 2, (bpf_int32)port);
5377 static struct block *
5378 gen_port6(compiler_state_t *cstate, int port, int ip_proto, int dir)
5380 struct block *b0, *b1, *tmp;
5382 /* link proto ip6 */
5383 b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
5389 b1 = gen_portop6(cstate, port, ip_proto, dir);
5393 tmp = gen_portop6(cstate, port, IPPROTO_TCP, dir);
5394 b1 = gen_portop6(cstate, port, IPPROTO_UDP, dir);
5396 tmp = gen_portop6(cstate, port, IPPROTO_SCTP, dir);
5407 /* gen_portrange code */
5408 static struct block *
5409 gen_portrangeatom(compiler_state_t *cstate, int off, bpf_int32 v1,
5412 struct block *b1, *b2;
5416 * Reverse the order of the ports, so v1 is the lower one.
5425 b1 = gen_cmp_ge(cstate, OR_TRAN_IPV4, off, BPF_H, v1);
5426 b2 = gen_cmp_le(cstate, OR_TRAN_IPV4, off, BPF_H, v2);
5434 gen_portrangeop(compiler_state_t *cstate, int port1, int port2, int proto,
5437 struct block *b0, *b1, *tmp;
5439 /* ip proto 'proto' and not a fragment other than the first fragment */
5440 tmp = gen_cmp(cstate, OR_LINKPL, 9, BPF_B, (bpf_int32)proto);
5441 b0 = gen_ipfrag(cstate);
5446 b1 = gen_portrangeatom(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
5450 b1 = gen_portrangeatom(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
5455 tmp = gen_portrangeatom(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
5456 b1 = gen_portrangeatom(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
5461 tmp = gen_portrangeatom(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
5462 b1 = gen_portrangeatom(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
5474 static struct block *
5475 gen_portrange(compiler_state_t *cstate, int port1, int port2, int ip_proto,
5478 struct block *b0, *b1, *tmp;
5481 b0 = gen_linktype(cstate, ETHERTYPE_IP);
5487 b1 = gen_portrangeop(cstate, port1, port2, ip_proto, dir);
5491 tmp = gen_portrangeop(cstate, port1, port2, IPPROTO_TCP, dir);
5492 b1 = gen_portrangeop(cstate, port1, port2, IPPROTO_UDP, dir);
5494 tmp = gen_portrangeop(cstate, port1, port2, IPPROTO_SCTP, dir);
5505 static struct block *
5506 gen_portrangeatom6(compiler_state_t *cstate, int off, bpf_int32 v1,
5509 struct block *b1, *b2;
5513 * Reverse the order of the ports, so v1 is the lower one.
5522 b1 = gen_cmp_ge(cstate, OR_TRAN_IPV6, off, BPF_H, v1);
5523 b2 = gen_cmp_le(cstate, OR_TRAN_IPV6, off, BPF_H, v2);
5531 gen_portrangeop6(compiler_state_t *cstate, int port1, int port2, int proto,
5534 struct block *b0, *b1, *tmp;
5536 /* ip6 proto 'proto' */
5537 /* XXX - catch the first fragment of a fragmented packet? */
5538 b0 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, (bpf_int32)proto);
5542 b1 = gen_portrangeatom6(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
5546 b1 = gen_portrangeatom6(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
5551 tmp = gen_portrangeatom6(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
5552 b1 = gen_portrangeatom6(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
5557 tmp = gen_portrangeatom6(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
5558 b1 = gen_portrangeatom6(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
5570 static struct block *
5571 gen_portrange6(compiler_state_t *cstate, int port1, int port2, int ip_proto,
5574 struct block *b0, *b1, *tmp;
5576 /* link proto ip6 */
5577 b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
5583 b1 = gen_portrangeop6(cstate, port1, port2, ip_proto, dir);
5587 tmp = gen_portrangeop6(cstate, port1, port2, IPPROTO_TCP, dir);
5588 b1 = gen_portrangeop6(cstate, port1, port2, IPPROTO_UDP, dir);
5590 tmp = gen_portrangeop6(cstate, port1, port2, IPPROTO_SCTP, dir);
5602 lookup_proto(compiler_state_t *cstate, const char *name, int proto)
5611 v = pcap_nametoproto(name);
5612 if (v == PROTO_UNDEF)
5613 bpf_error(cstate, "unknown ip proto '%s'", name);
5617 /* XXX should look up h/w protocol type based on cstate->linktype */
5618 v = pcap_nametoeproto(name);
5619 if (v == PROTO_UNDEF) {
5620 v = pcap_nametollc(name);
5621 if (v == PROTO_UNDEF)
5622 bpf_error(cstate, "unknown ether proto '%s'", name);
5627 if (strcmp(name, "esis") == 0)
5629 else if (strcmp(name, "isis") == 0)
5631 else if (strcmp(name, "clnp") == 0)
5634 bpf_error(cstate, "unknown osi proto '%s'", name);
5654 static struct block *
5655 gen_protochain(compiler_state_t *cstate, int v, int proto, int dir)
5657 #ifdef NO_PROTOCHAIN
5658 return gen_proto(cstate, v, proto, dir);
5660 struct block *b0, *b;
5661 struct slist *s[100];
5662 int fix2, fix3, fix4, fix5;
5663 int ahcheck, again, end;
5665 int reg2 = alloc_reg(cstate);
5667 memset(s, 0, sizeof(s));
5668 fix3 = fix4 = fix5 = 0;
5675 b0 = gen_protochain(cstate, v, Q_IP, dir);
5676 b = gen_protochain(cstate, v, Q_IPV6, dir);
5680 bpf_error(cstate, "bad protocol applied for 'protochain'");
5685 * We don't handle variable-length prefixes before the link-layer
5686 * header, or variable-length link-layer headers, here yet.
5687 * We might want to add BPF instructions to do the protochain
5688 * work, to simplify that and, on platforms that have a BPF
5689 * interpreter with the new instructions, let the filtering
5690 * be done in the kernel. (We already require a modified BPF
5691 * engine to do the protochain stuff, to support backward
5692 * branches, and backward branch support is unlikely to appear
5693 * in kernel BPF engines.)
5695 if (cstate->off_linkpl.is_variable)
5696 bpf_error(cstate, "'protochain' not supported with variable length headers");
5698 cstate->no_optimize = 1; /*this code is not compatible with optimzer yet */
5701 * s[0] is a dummy entry to protect other BPF insn from damage
5702 * by s[fix] = foo with uninitialized variable "fix". It is somewhat
5703 * hard to find interdependency made by jump table fixup.
5706 s[i] = new_stmt(cstate, 0); /*dummy*/
5711 b0 = gen_linktype(cstate, ETHERTYPE_IP);
5714 s[i] = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B);
5715 s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 9;
5717 /* X = ip->ip_hl << 2 */
5718 s[i] = new_stmt(cstate, BPF_LDX|BPF_MSH|BPF_B);
5719 s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
5724 b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
5726 /* A = ip6->ip_nxt */
5727 s[i] = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B);
5728 s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 6;
5730 /* X = sizeof(struct ip6_hdr) */
5731 s[i] = new_stmt(cstate, BPF_LDX|BPF_IMM);
5737 bpf_error(cstate, "unsupported proto to gen_protochain");
5741 /* again: if (A == v) goto end; else fall through; */
5743 s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
5745 s[i]->s.jt = NULL; /*later*/
5746 s[i]->s.jf = NULL; /*update in next stmt*/
5750 #ifndef IPPROTO_NONE
5751 #define IPPROTO_NONE 59
5753 /* if (A == IPPROTO_NONE) goto end */
5754 s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
5755 s[i]->s.jt = NULL; /*later*/
5756 s[i]->s.jf = NULL; /*update in next stmt*/
5757 s[i]->s.k = IPPROTO_NONE;
5758 s[fix5]->s.jf = s[i];
5762 if (proto == Q_IPV6) {
5763 int v6start, v6end, v6advance, j;
5766 /* if (A == IPPROTO_HOPOPTS) goto v6advance */
5767 s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
5768 s[i]->s.jt = NULL; /*later*/
5769 s[i]->s.jf = NULL; /*update in next stmt*/
5770 s[i]->s.k = IPPROTO_HOPOPTS;
5771 s[fix2]->s.jf = s[i];
5773 /* if (A == IPPROTO_DSTOPTS) goto v6advance */
5774 s[i - 1]->s.jf = s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
5775 s[i]->s.jt = NULL; /*later*/
5776 s[i]->s.jf = NULL; /*update in next stmt*/
5777 s[i]->s.k = IPPROTO_DSTOPTS;
5779 /* if (A == IPPROTO_ROUTING) goto v6advance */
5780 s[i - 1]->s.jf = s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
5781 s[i]->s.jt = NULL; /*later*/
5782 s[i]->s.jf = NULL; /*update in next stmt*/
5783 s[i]->s.k = IPPROTO_ROUTING;
5785 /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */
5786 s[i - 1]->s.jf = s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
5787 s[i]->s.jt = NULL; /*later*/
5788 s[i]->s.jf = NULL; /*later*/
5789 s[i]->s.k = IPPROTO_FRAGMENT;
5799 * A = P[X + packet head];
5800 * X = X + (P[X + packet head + 1] + 1) * 8;
5802 /* A = P[X + packet head] */
5803 s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
5804 s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
5807 s[i] = new_stmt(cstate, BPF_ST);
5810 /* A = P[X + packet head + 1]; */
5811 s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
5812 s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 1;
5815 s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
5819 s[i] = new_stmt(cstate, BPF_ALU|BPF_MUL|BPF_K);
5823 s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X);
5827 s[i] = new_stmt(cstate, BPF_MISC|BPF_TAX);
5830 s[i] = new_stmt(cstate, BPF_LD|BPF_MEM);
5834 /* goto again; (must use BPF_JA for backward jump) */
5835 s[i] = new_stmt(cstate, BPF_JMP|BPF_JA);
5836 s[i]->s.k = again - i - 1;
5837 s[i - 1]->s.jf = s[i];
5841 for (j = v6start; j <= v6end; j++)
5842 s[j]->s.jt = s[v6advance];
5845 s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
5847 s[fix2]->s.jf = s[i];
5853 /* if (A == IPPROTO_AH) then fall through; else goto end; */
5854 s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
5855 s[i]->s.jt = NULL; /*later*/
5856 s[i]->s.jf = NULL; /*later*/
5857 s[i]->s.k = IPPROTO_AH;
5859 s[fix3]->s.jf = s[ahcheck];
5866 * X = X + (P[X + 1] + 2) * 4;
5869 s[i - 1]->s.jt = s[i] = new_stmt(cstate, BPF_MISC|BPF_TXA);
5871 /* A = P[X + packet head]; */
5872 s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
5873 s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
5876 s[i] = new_stmt(cstate, BPF_ST);
5880 s[i - 1]->s.jt = s[i] = new_stmt(cstate, BPF_MISC|BPF_TXA);
5883 s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
5887 s[i] = new_stmt(cstate, BPF_MISC|BPF_TAX);
5889 /* A = P[X + packet head] */
5890 s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
5891 s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
5894 s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
5898 s[i] = new_stmt(cstate, BPF_ALU|BPF_MUL|BPF_K);
5902 s[i] = new_stmt(cstate, BPF_MISC|BPF_TAX);
5905 s[i] = new_stmt(cstate, BPF_LD|BPF_MEM);
5909 /* goto again; (must use BPF_JA for backward jump) */
5910 s[i] = new_stmt(cstate, BPF_JMP|BPF_JA);
5911 s[i]->s.k = again - i - 1;
5916 s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
5918 s[fix2]->s.jt = s[end];
5919 s[fix4]->s.jf = s[end];
5920 s[fix5]->s.jt = s[end];
5927 for (i = 0; i < max - 1; i++)
5928 s[i]->next = s[i + 1];
5929 s[max - 1]->next = NULL;
5934 b = new_block(cstate, JMP(BPF_JEQ));
5935 b->stmts = s[1]; /*remember, s[0] is dummy*/
5938 free_reg(cstate, reg2);
5945 static struct block *
5946 gen_check_802_11_data_frame(compiler_state_t *cstate)
5949 struct block *b0, *b1;
5952 * A data frame has the 0x08 bit (b3) in the frame control field set
5953 * and the 0x04 bit (b2) clear.
5955 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
5956 b0 = new_block(cstate, JMP(BPF_JSET));
5960 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
5961 b1 = new_block(cstate, JMP(BPF_JSET));
5972 * Generate code that checks whether the packet is a packet for protocol
5973 * <proto> and whether the type field in that protocol's header has
5974 * the value <v>, e.g. if <proto> is Q_IP, it checks whether it's an
5975 * IP packet and checks the protocol number in the IP header against <v>.
5977 * If <proto> is Q_DEFAULT, i.e. just "proto" was specified, it checks
5978 * against Q_IP and Q_IPV6.
5980 static struct block *
5981 gen_proto(compiler_state_t *cstate, int v, int proto, int dir)
5983 struct block *b0, *b1;
5988 if (dir != Q_DEFAULT)
5989 bpf_error(cstate, "direction applied to 'proto'");
5993 b0 = gen_proto(cstate, v, Q_IP, dir);
5994 b1 = gen_proto(cstate, v, Q_IPV6, dir);
6000 * For FDDI, RFC 1188 says that SNAP encapsulation is used,
6001 * not LLC encapsulation with LLCSAP_IP.
6003 * For IEEE 802 networks - which includes 802.5 token ring
6004 * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042
6005 * says that SNAP encapsulation is used, not LLC encapsulation
6008 * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and
6009 * RFC 2225 say that SNAP encapsulation is used, not LLC
6010 * encapsulation with LLCSAP_IP.
6012 * So we always check for ETHERTYPE_IP.
6014 b0 = gen_linktype(cstate, ETHERTYPE_IP);
6016 b1 = gen_cmp(cstate, OR_LINKPL, 9, BPF_B, (bpf_int32)v);
6018 b1 = gen_protochain(cstate, v, Q_IP);
6024 switch (cstate->linktype) {
6028 * Frame Relay packets typically have an OSI
6029 * NLPID at the beginning; "gen_linktype(cstate, LLCSAP_ISONS)"
6030 * generates code to check for all the OSI
6031 * NLPIDs, so calling it and then adding a check
6032 * for the particular NLPID for which we're
6033 * looking is bogus, as we can just check for
6036 * What we check for is the NLPID and a frame
6037 * control field value of UI, i.e. 0x03 followed
6040 * XXX - assumes a 2-byte Frame Relay header with
6041 * DLCI and flags. What if the address is longer?
6043 * XXX - what about SNAP-encapsulated frames?
6045 return gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | v);
6051 * Cisco uses an Ethertype lookalike - for OSI,
6054 b0 = gen_linktype(cstate, LLCSAP_ISONS<<8 | LLCSAP_ISONS);
6055 /* OSI in C-HDLC is stuffed with a fudge byte */
6056 b1 = gen_cmp(cstate, OR_LINKPL_NOSNAP, 1, BPF_B, (long)v);
6061 b0 = gen_linktype(cstate, LLCSAP_ISONS);
6062 b1 = gen_cmp(cstate, OR_LINKPL_NOSNAP, 0, BPF_B, (long)v);
6068 b0 = gen_proto(cstate, ISO10589_ISIS, Q_ISO, Q_DEFAULT);
6070 * 4 is the offset of the PDU type relative to the IS-IS
6073 b1 = gen_cmp(cstate, OR_LINKPL_NOSNAP, 4, BPF_B, (long)v);
6078 bpf_error(cstate, "arp does not encapsulate another protocol");
6082 bpf_error(cstate, "rarp does not encapsulate another protocol");
6086 bpf_error(cstate, "atalk encapsulation is not specifiable");
6090 bpf_error(cstate, "decnet encapsulation is not specifiable");
6094 bpf_error(cstate, "sca does not encapsulate another protocol");
6098 bpf_error(cstate, "lat does not encapsulate another protocol");
6102 bpf_error(cstate, "moprc does not encapsulate another protocol");
6106 bpf_error(cstate, "mopdl does not encapsulate another protocol");
6110 return gen_linktype(cstate, v);
6113 bpf_error(cstate, "'udp proto' is bogus");
6117 bpf_error(cstate, "'tcp proto' is bogus");
6121 bpf_error(cstate, "'sctp proto' is bogus");
6125 bpf_error(cstate, "'icmp proto' is bogus");
6129 bpf_error(cstate, "'igmp proto' is bogus");
6133 bpf_error(cstate, "'igrp proto' is bogus");
6137 bpf_error(cstate, "'pim proto' is bogus");
6141 bpf_error(cstate, "'vrrp proto' is bogus");
6145 bpf_error(cstate, "'carp proto' is bogus");
6149 b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
6152 * Also check for a fragment header before the final
6155 b2 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, IPPROTO_FRAGMENT);
6156 b1 = gen_cmp(cstate, OR_LINKPL, 40, BPF_B, (bpf_int32)v);
6158 b2 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, (bpf_int32)v);
6161 b1 = gen_protochain(cstate, v, Q_IPV6);
6167 bpf_error(cstate, "'icmp6 proto' is bogus");
6170 bpf_error(cstate, "'ah proto' is bogus");
6173 bpf_error(cstate, "'ah proto' is bogus");
6176 bpf_error(cstate, "'stp proto' is bogus");
6179 bpf_error(cstate, "'ipx proto' is bogus");
6182 bpf_error(cstate, "'netbeui proto' is bogus");
6185 bpf_error(cstate, "'radio proto' is bogus");
6195 gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
6197 int proto = q.proto;
6201 bpf_u_int32 mask, addr;
6203 bpf_u_int32 **alist;
6206 struct sockaddr_in *sin4;
6207 struct sockaddr_in6 *sin6;
6208 struct addrinfo *res, *res0;
6209 struct in6_addr mask128;
6211 struct block *b, *tmp;
6212 int port, real_proto;
6218 addr = pcap_nametonetaddr(name);
6220 bpf_error(cstate, "unknown network '%s'", name);
6221 /* Left justify network addr and calculate its network mask */
6223 while (addr && (addr & 0xff000000) == 0) {
6227 return gen_host(cstate, addr, mask, proto, dir, q.addr);
6231 if (proto == Q_LINK) {
6232 switch (cstate->linktype) {
6235 case DLT_NETANALYZER:
6236 case DLT_NETANALYZER_TRANSPARENT:
6237 eaddr = pcap_ether_hostton(name);
6240 "unknown ether host '%s'", name);
6241 tmp = gen_prevlinkhdr_check(cstate);
6242 b = gen_ehostop(cstate, eaddr, dir);
6249 eaddr = pcap_ether_hostton(name);
6252 "unknown FDDI host '%s'", name);
6253 b = gen_fhostop(cstate, eaddr, dir);
6258 eaddr = pcap_ether_hostton(name);
6261 "unknown token ring host '%s'", name);
6262 b = gen_thostop(cstate, eaddr, dir);
6266 case DLT_IEEE802_11:
6267 case DLT_PRISM_HEADER:
6268 case DLT_IEEE802_11_RADIO_AVS:
6269 case DLT_IEEE802_11_RADIO:
6271 eaddr = pcap_ether_hostton(name);
6274 "unknown 802.11 host '%s'", name);
6275 b = gen_wlanhostop(cstate, eaddr, dir);
6279 case DLT_IP_OVER_FC:
6280 eaddr = pcap_ether_hostton(name);
6283 "unknown Fibre Channel host '%s'", name);
6284 b = gen_ipfchostop(cstate, eaddr, dir);
6289 bpf_error(cstate, "only ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel supports link-level host name");
6290 } else if (proto == Q_DECNET) {
6291 unsigned short dn_addr;
6293 if (!__pcap_nametodnaddr(name, &dn_addr)) {
6295 bpf_error(cstate, "unknown decnet host name '%s'\n", name);
6297 bpf_error(cstate, "decnet name support not included, '%s' cannot be translated\n",
6302 * I don't think DECNET hosts can be multihomed, so
6303 * there is no need to build up a list of addresses
6305 return (gen_host(cstate, dn_addr, 0, proto, dir, q.addr));
6308 alist = pcap_nametoaddr(name);
6309 if (alist == NULL || *alist == NULL)
6310 bpf_error(cstate, "unknown host '%s'", name);
6312 if (cstate->off_linktype.constant_part == OFFSET_NOT_SET &&
6313 tproto == Q_DEFAULT)
6315 b = gen_host(cstate, **alist++, 0xffffffff, tproto, dir, q.addr);
6317 tmp = gen_host(cstate, **alist++, 0xffffffff,
6318 tproto, dir, q.addr);
6324 memset(&mask128, 0xff, sizeof(mask128));
6325 res0 = res = pcap_nametoaddrinfo(name);
6327 bpf_error(cstate, "unknown host '%s'", name);
6330 tproto = tproto6 = proto;
6331 if (cstate->off_linktype.constant_part == OFFSET_NOT_SET &&
6332 tproto == Q_DEFAULT) {
6336 for (res = res0; res; res = res->ai_next) {
6337 switch (res->ai_family) {
6339 if (tproto == Q_IPV6)
6342 sin4 = (struct sockaddr_in *)
6344 tmp = gen_host(cstate, ntohl(sin4->sin_addr.s_addr),
6345 0xffffffff, tproto, dir, q.addr);
6348 if (tproto6 == Q_IP)
6351 sin6 = (struct sockaddr_in6 *)
6353 tmp = gen_host6(cstate, &sin6->sin6_addr,
6354 &mask128, tproto6, dir, q.addr);
6366 bpf_error(cstate, "unknown host '%s'%s", name,
6367 (proto == Q_DEFAULT)
6369 : " for specified address family");
6376 if (proto != Q_DEFAULT &&
6377 proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP)
6378 bpf_error(cstate, "illegal qualifier of 'port'");
6379 if (pcap_nametoport(name, &port, &real_proto) == 0)
6380 bpf_error(cstate, "unknown port '%s'", name);
6381 if (proto == Q_UDP) {
6382 if (real_proto == IPPROTO_TCP)
6383 bpf_error(cstate, "port '%s' is tcp", name);
6384 else if (real_proto == IPPROTO_SCTP)
6385 bpf_error(cstate, "port '%s' is sctp", name);
6387 /* override PROTO_UNDEF */
6388 real_proto = IPPROTO_UDP;
6390 if (proto == Q_TCP) {
6391 if (real_proto == IPPROTO_UDP)
6392 bpf_error(cstate, "port '%s' is udp", name);
6394 else if (real_proto == IPPROTO_SCTP)
6395 bpf_error(cstate, "port '%s' is sctp", name);
6397 /* override PROTO_UNDEF */
6398 real_proto = IPPROTO_TCP;
6400 if (proto == Q_SCTP) {
6401 if (real_proto == IPPROTO_UDP)
6402 bpf_error(cstate, "port '%s' is udp", name);
6404 else if (real_proto == IPPROTO_TCP)
6405 bpf_error(cstate, "port '%s' is tcp", name);
6407 /* override PROTO_UNDEF */
6408 real_proto = IPPROTO_SCTP;
6411 bpf_error(cstate, "illegal port number %d < 0", port);
6413 bpf_error(cstate, "illegal port number %d > 65535", port);
6414 b = gen_port(cstate, port, real_proto, dir);
6415 gen_or(gen_port6(cstate, port, real_proto, dir), b);
6419 if (proto != Q_DEFAULT &&
6420 proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP)
6421 bpf_error(cstate, "illegal qualifier of 'portrange'");
6422 if (pcap_nametoportrange(name, &port1, &port2, &real_proto) == 0)
6423 bpf_error(cstate, "unknown port in range '%s'", name);
6424 if (proto == Q_UDP) {
6425 if (real_proto == IPPROTO_TCP)
6426 bpf_error(cstate, "port in range '%s' is tcp", name);
6427 else if (real_proto == IPPROTO_SCTP)
6428 bpf_error(cstate, "port in range '%s' is sctp", name);
6430 /* override PROTO_UNDEF */
6431 real_proto = IPPROTO_UDP;
6433 if (proto == Q_TCP) {
6434 if (real_proto == IPPROTO_UDP)
6435 bpf_error(cstate, "port in range '%s' is udp", name);
6436 else if (real_proto == IPPROTO_SCTP)
6437 bpf_error(cstate, "port in range '%s' is sctp", name);
6439 /* override PROTO_UNDEF */
6440 real_proto = IPPROTO_TCP;
6442 if (proto == Q_SCTP) {
6443 if (real_proto == IPPROTO_UDP)
6444 bpf_error(cstate, "port in range '%s' is udp", name);
6445 else if (real_proto == IPPROTO_TCP)
6446 bpf_error(cstate, "port in range '%s' is tcp", name);
6448 /* override PROTO_UNDEF */
6449 real_proto = IPPROTO_SCTP;
6452 bpf_error(cstate, "illegal port number %d < 0", port1);
6454 bpf_error(cstate, "illegal port number %d > 65535", port1);
6456 bpf_error(cstate, "illegal port number %d < 0", port2);
6458 bpf_error(cstate, "illegal port number %d > 65535", port2);
6460 b = gen_portrange(cstate, port1, port2, real_proto, dir);
6461 gen_or(gen_portrange6(cstate, port1, port2, real_proto, dir), b);
6466 eaddr = pcap_ether_hostton(name);
6468 bpf_error(cstate, "unknown ether host: %s", name);
6470 alist = pcap_nametoaddr(name);
6471 if (alist == NULL || *alist == NULL)
6472 bpf_error(cstate, "unknown host '%s'", name);
6473 b = gen_gateway(eaddr, alist, proto, dir);
6477 bpf_error(cstate, "'gateway' not supported in this configuration");
6481 real_proto = lookup_proto(cstate, name, proto);
6482 if (real_proto >= 0)
6483 return gen_proto(cstate, real_proto, proto, dir);
6485 bpf_error(cstate, "unknown protocol: %s", name);
6488 real_proto = lookup_proto(cstate, name, proto);
6489 if (real_proto >= 0)
6490 return gen_protochain(cstate, real_proto, proto, dir);
6492 bpf_error(cstate, "unknown protocol: %s", name);
6503 gen_mcode(compiler_state_t *cstate, const char *s1, const char *s2,
6504 unsigned int masklen, struct qual q)
6506 register int nlen, mlen;
6509 nlen = __pcap_atoin(s1, &n);
6510 /* Promote short ipaddr */
6514 mlen = __pcap_atoin(s2, &m);
6515 /* Promote short ipaddr */
6518 bpf_error(cstate, "non-network bits set in \"%s mask %s\"",
6521 /* Convert mask len to mask */
6523 bpf_error(cstate, "mask length must be <= 32");
6526 * X << 32 is not guaranteed by C to be 0; it's
6531 m = 0xffffffff << (32 - masklen);
6533 bpf_error(cstate, "non-network bits set in \"%s/%d\"",
6540 return gen_host(cstate, n, m, q.proto, q.dir, q.addr);
6543 bpf_error(cstate, "Mask syntax for networks only");
6551 gen_ncode(compiler_state_t *cstate, const char *s, bpf_u_int32 v, struct qual q)
6554 int proto = q.proto;
6560 else if (q.proto == Q_DECNET) {
6561 vlen = __pcap_atodn(s, &v);
6563 bpf_error(cstate, "malformed decnet address '%s'", s);
6565 vlen = __pcap_atoin(s, &v);
6572 if (proto == Q_DECNET)
6573 return gen_host(cstate, v, 0, proto, dir, q.addr);
6574 else if (proto == Q_LINK) {
6575 bpf_error(cstate, "illegal link layer address");
6578 if (s == NULL && q.addr == Q_NET) {
6579 /* Promote short net number */
6580 while (v && (v & 0xff000000) == 0) {
6585 /* Promote short ipaddr */
6587 mask <<= 32 - vlen ;
6589 return gen_host(cstate, v, mask, proto, dir, q.addr);
6594 proto = IPPROTO_UDP;
6595 else if (proto == Q_TCP)
6596 proto = IPPROTO_TCP;
6597 else if (proto == Q_SCTP)
6598 proto = IPPROTO_SCTP;
6599 else if (proto == Q_DEFAULT)
6600 proto = PROTO_UNDEF;
6602 bpf_error(cstate, "illegal qualifier of 'port'");
6605 bpf_error(cstate, "illegal port number %u > 65535", v);
6609 b = gen_port(cstate, (int)v, proto, dir);
6610 gen_or(gen_port6(cstate, (int)v, proto, dir), b);
6616 proto = IPPROTO_UDP;
6617 else if (proto == Q_TCP)
6618 proto = IPPROTO_TCP;
6619 else if (proto == Q_SCTP)
6620 proto = IPPROTO_SCTP;
6621 else if (proto == Q_DEFAULT)
6622 proto = PROTO_UNDEF;
6624 bpf_error(cstate, "illegal qualifier of 'portrange'");
6627 bpf_error(cstate, "illegal port number %u > 65535", v);
6631 b = gen_portrange(cstate, (int)v, (int)v, proto, dir);
6632 gen_or(gen_portrange6(cstate, (int)v, (int)v, proto, dir), b);
6637 bpf_error(cstate, "'gateway' requires a name");
6641 return gen_proto(cstate, (int)v, proto, dir);
6644 return gen_protochain(cstate, (int)v, proto, dir);
6659 gen_mcode6(compiler_state_t *cstate, const char *s1, const char *s2,
6660 unsigned int masklen, struct qual q)
6662 struct addrinfo *res;
6663 struct in6_addr *addr;
6664 struct in6_addr mask;
6669 bpf_error(cstate, "no mask %s supported", s2);
6671 res = pcap_nametoaddrinfo(s1);
6673 bpf_error(cstate, "invalid ip6 address %s", s1);
6676 bpf_error(cstate, "%s resolved to multiple address", s1);
6677 addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr;
6679 if (sizeof(mask) * 8 < masklen)
6680 bpf_error(cstate, "mask length must be <= %u", (unsigned int)(sizeof(mask) * 8));
6681 memset(&mask, 0, sizeof(mask));
6682 memset(&mask, 0xff, masklen / 8);
6684 mask.s6_addr[masklen / 8] =
6685 (0xff << (8 - masklen % 8)) & 0xff;
6688 a = (u_int32_t *)addr;
6689 m = (u_int32_t *)&mask;
6690 if ((a[0] & ~m[0]) || (a[1] & ~m[1])
6691 || (a[2] & ~m[2]) || (a[3] & ~m[3])) {
6692 bpf_error(cstate, "non-network bits set in \"%s/%d\"", s1, masklen);
6700 bpf_error(cstate, "Mask syntax for networks only");
6704 b = gen_host6(cstate, addr, &mask, q.proto, q.dir, q.addr);
6710 bpf_error(cstate, "invalid qualifier against IPv6 address");
6718 gen_ecode(compiler_state_t *cstate, const u_char *eaddr, struct qual q)
6720 struct block *b, *tmp;
6722 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
6723 switch (cstate->linktype) {
6725 case DLT_NETANALYZER:
6726 case DLT_NETANALYZER_TRANSPARENT:
6727 tmp = gen_prevlinkhdr_check(cstate);
6728 b = gen_ehostop(cstate, eaddr, (int)q.dir);
6733 return gen_fhostop(cstate, eaddr, (int)q.dir);
6735 return gen_thostop(cstate, eaddr, (int)q.dir);
6736 case DLT_IEEE802_11:
6737 case DLT_PRISM_HEADER:
6738 case DLT_IEEE802_11_RADIO_AVS:
6739 case DLT_IEEE802_11_RADIO:
6741 return gen_wlanhostop(cstate, eaddr, (int)q.dir);
6742 case DLT_IP_OVER_FC:
6743 return gen_ipfchostop(cstate, eaddr, (int)q.dir);
6745 bpf_error(cstate, "ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
6749 bpf_error(cstate, "ethernet address used in non-ether expression");
6756 struct slist *s0, *s1;
6759 * This is definitely not the best way to do this, but the
6760 * lists will rarely get long.
6767 static struct slist *
6768 xfer_to_x(compiler_state_t *cstate, struct arth *a)
6772 s = new_stmt(cstate, BPF_LDX|BPF_MEM);
6777 static struct slist *
6778 xfer_to_a(compiler_state_t *cstate, struct arth *a)
6782 s = new_stmt(cstate, BPF_LD|BPF_MEM);
6788 * Modify "index" to use the value stored into its register as an
6789 * offset relative to the beginning of the header for the protocol
6790 * "proto", and allocate a register and put an item "size" bytes long
6791 * (1, 2, or 4) at that offset into that register, making it the register
6795 gen_load(compiler_state_t *cstate, int proto, struct arth *inst, int size)
6797 struct slist *s, *tmp;
6799 int regno = alloc_reg(cstate);
6801 free_reg(cstate, inst->regno);
6805 bpf_error(cstate, "data size must be 1, 2, or 4");
6821 bpf_error(cstate, "unsupported index operation");
6825 * The offset is relative to the beginning of the packet
6826 * data, if we have a radio header. (If we don't, this
6829 if (cstate->linktype != DLT_IEEE802_11_RADIO_AVS &&
6830 cstate->linktype != DLT_IEEE802_11_RADIO &&
6831 cstate->linktype != DLT_PRISM_HEADER)
6832 bpf_error(cstate, "radio information not present in capture");
6835 * Load into the X register the offset computed into the
6836 * register specified by "index".
6838 s = xfer_to_x(cstate, inst);
6841 * Load the item at that offset.
6843 tmp = new_stmt(cstate, BPF_LD|BPF_IND|size);
6845 sappend(inst->s, s);
6850 * The offset is relative to the beginning of
6851 * the link-layer header.
6853 * XXX - what about ATM LANE? Should the index be
6854 * relative to the beginning of the AAL5 frame, so
6855 * that 0 refers to the beginning of the LE Control
6856 * field, or relative to the beginning of the LAN
6857 * frame, so that 0 refers, for Ethernet LANE, to
6858 * the beginning of the destination address?
6860 s = gen_abs_offset_varpart(cstate, &cstate->off_linkhdr);
6863 * If "s" is non-null, it has code to arrange that the
6864 * X register contains the length of the prefix preceding
6865 * the link-layer header. Add to it the offset computed
6866 * into the register specified by "index", and move that
6867 * into the X register. Otherwise, just load into the X
6868 * register the offset computed into the register specified
6872 sappend(s, xfer_to_a(cstate, inst));
6873 sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X));
6874 sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX));
6876 s = xfer_to_x(cstate, inst);
6879 * Load the item at the sum of the offset we've put in the
6880 * X register and the offset of the start of the link
6881 * layer header (which is 0 if the radio header is
6882 * variable-length; that header length is what we put
6883 * into the X register and then added to the index).
6885 tmp = new_stmt(cstate, BPF_LD|BPF_IND|size);
6886 tmp->s.k = cstate->off_linkhdr.constant_part;
6888 sappend(inst->s, s);
6902 * The offset is relative to the beginning of
6903 * the network-layer header.
6904 * XXX - are there any cases where we want
6905 * cstate->off_nl_nosnap?
6907 s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl);
6910 * If "s" is non-null, it has code to arrange that the
6911 * X register contains the variable part of the offset
6912 * of the link-layer payload. Add to it the offset
6913 * computed into the register specified by "index",
6914 * and move that into the X register. Otherwise, just
6915 * load into the X register the offset computed into
6916 * the register specified by "index".
6919 sappend(s, xfer_to_a(cstate, inst));
6920 sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X));
6921 sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX));
6923 s = xfer_to_x(cstate, inst);
6926 * Load the item at the sum of the offset we've put in the
6927 * X register, the offset of the start of the network
6928 * layer header from the beginning of the link-layer
6929 * payload, and the constant part of the offset of the
6930 * start of the link-layer payload.
6932 tmp = new_stmt(cstate, BPF_LD|BPF_IND|size);
6933 tmp->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
6935 sappend(inst->s, s);
6938 * Do the computation only if the packet contains
6939 * the protocol in question.
6941 b = gen_proto_abbrev(cstate, proto);
6943 gen_and(inst->b, b);
6957 * The offset is relative to the beginning of
6958 * the transport-layer header.
6960 * Load the X register with the length of the IPv4 header
6961 * (plus the offset of the link-layer header, if it's
6962 * a variable-length header), in bytes.
6964 * XXX - are there any cases where we want
6965 * cstate->off_nl_nosnap?
6966 * XXX - we should, if we're built with
6967 * IPv6 support, generate code to load either
6968 * IPv4, IPv6, or both, as appropriate.
6970 s = gen_loadx_iphdrlen(cstate);
6973 * The X register now contains the sum of the variable
6974 * part of the offset of the link-layer payload and the
6975 * length of the network-layer header.
6977 * Load into the A register the offset relative to
6978 * the beginning of the transport layer header,
6979 * add the X register to that, move that to the
6980 * X register, and load with an offset from the
6981 * X register equal to the sum of the constant part of
6982 * the offset of the link-layer payload and the offset,
6983 * relative to the beginning of the link-layer payload,
6984 * of the network-layer header.
6986 sappend(s, xfer_to_a(cstate, inst));
6987 sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X));
6988 sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX));
6989 sappend(s, tmp = new_stmt(cstate, BPF_LD|BPF_IND|size));
6990 tmp->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
6991 sappend(inst->s, s);
6994 * Do the computation only if the packet contains
6995 * the protocol in question - which is true only
6996 * if this is an IP datagram and is the first or
6997 * only fragment of that datagram.
6999 gen_and(gen_proto_abbrev(cstate, proto), b = gen_ipfrag(cstate));
7001 gen_and(inst->b, b);
7002 gen_and(gen_proto_abbrev(cstate, Q_IP), b);
7006 bpf_error(cstate, "IPv6 upper-layer protocol is not supported by proto[x]");
7009 inst->regno = regno;
7010 s = new_stmt(cstate, BPF_ST);
7012 sappend(inst->s, s);
7018 gen_relation(compiler_state_t *cstate, int code, struct arth *a0,
7019 struct arth *a1, int reversed)
7021 struct slist *s0, *s1, *s2;
7022 struct block *b, *tmp;
7024 s0 = xfer_to_x(cstate, a1);
7025 s1 = xfer_to_a(cstate, a0);
7026 if (code == BPF_JEQ) {
7027 s2 = new_stmt(cstate, BPF_ALU|BPF_SUB|BPF_X);
7028 b = new_block(cstate, JMP(code));
7032 b = new_block(cstate, BPF_JMP|code|BPF_X);
7038 sappend(a0->s, a1->s);
7042 free_reg(cstate, a0->regno);
7043 free_reg(cstate, a1->regno);
7045 /* 'and' together protocol checks */
7048 gen_and(a0->b, tmp = a1->b);
7062 gen_loadlen(compiler_state_t *cstate)
7064 int regno = alloc_reg(cstate);
7065 struct arth *a = (struct arth *)newchunk(cstate, sizeof(*a));
7068 s = new_stmt(cstate, BPF_LD|BPF_LEN);
7069 s->next = new_stmt(cstate, BPF_ST);
7070 s->next->s.k = regno;
7078 gen_loadi(compiler_state_t *cstate, int val)
7084 a = (struct arth *)newchunk(cstate, sizeof(*a));
7086 reg = alloc_reg(cstate);
7088 s = new_stmt(cstate, BPF_LD|BPF_IMM);
7090 s->next = new_stmt(cstate, BPF_ST);
7099 gen_neg(compiler_state_t *cstate, struct arth *a)
7103 s = xfer_to_a(cstate, a);
7105 s = new_stmt(cstate, BPF_ALU|BPF_NEG);
7108 s = new_stmt(cstate, BPF_ST);
7116 gen_arth(compiler_state_t *cstate, int code, struct arth *a0,
7119 struct slist *s0, *s1, *s2;
7122 * Disallow division by, or modulus by, zero; we do this here
7123 * so that it gets done even if the optimizer is disabled.
7125 if (code == BPF_DIV) {
7126 if (a1->s->s.code == (BPF_LD|BPF_IMM) && a1->s->s.k == 0)
7127 bpf_error(cstate, "division by zero");
7128 } else if (code == BPF_MOD) {
7129 if (a1->s->s.code == (BPF_LD|BPF_IMM) && a1->s->s.k == 0)
7130 bpf_error(cstate, "modulus by zero");
7132 s0 = xfer_to_x(cstate, a1);
7133 s1 = xfer_to_a(cstate, a0);
7134 s2 = new_stmt(cstate, BPF_ALU|BPF_X|code);
7139 sappend(a0->s, a1->s);
7141 free_reg(cstate, a0->regno);
7142 free_reg(cstate, a1->regno);
7144 s0 = new_stmt(cstate, BPF_ST);
7145 a0->regno = s0->s.k = alloc_reg(cstate);
7152 * Initialize the table of used registers and the current register.
7155 init_regs(compiler_state_t *cstate)
7158 memset(cstate->regused, 0, sizeof cstate->regused);
7162 * Return the next free register.
7165 alloc_reg(compiler_state_t *cstate)
7167 int n = BPF_MEMWORDS;
7170 if (cstate->regused[cstate->curreg])
7171 cstate->curreg = (cstate->curreg + 1) % BPF_MEMWORDS;
7173 cstate->regused[cstate->curreg] = 1;
7174 return cstate->curreg;
7177 bpf_error(cstate, "too many registers needed to evaluate expression");
7183 * Return a register to the table so it can
7187 free_reg(compiler_state_t *cstate, int n)
7189 cstate->regused[n] = 0;
7192 static struct block *
7193 gen_len(compiler_state_t *cstate, int jmp, int n)
7198 s = new_stmt(cstate, BPF_LD|BPF_LEN);
7199 b = new_block(cstate, JMP(jmp));
7207 gen_greater(compiler_state_t *cstate, int n)
7209 return gen_len(cstate, BPF_JGE, n);
7213 * Actually, this is less than or equal.
7216 gen_less(compiler_state_t *cstate, int n)
7220 b = gen_len(cstate, BPF_JGT, n);
7227 * This is for "byte {idx} {op} {val}"; "idx" is treated as relative to
7228 * the beginning of the link-layer header.
7229 * XXX - that means you can't test values in the radiotap header, but
7230 * as that header is difficult if not impossible to parse generally
7231 * without a loop, that might not be a severe problem. A new keyword
7232 * "radio" could be added for that, although what you'd really want
7233 * would be a way of testing particular radio header values, which
7234 * would generate code appropriate to the radio header in question.
7237 gen_byteop(compiler_state_t *cstate, int op, int idx, int val)
7247 return gen_cmp(cstate, OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val);
7250 b = gen_cmp_lt(cstate, OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val);
7254 b = gen_cmp_gt(cstate, OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val);
7258 s = new_stmt(cstate, BPF_ALU|BPF_OR|BPF_K);
7262 s = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
7266 b = new_block(cstate, JMP(BPF_JEQ));
7273 static const u_char abroadcast[] = { 0x0 };
7276 gen_broadcast(compiler_state_t *cstate, int proto)
7278 bpf_u_int32 hostmask;
7279 struct block *b0, *b1, *b2;
7280 static const u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
7286 switch (cstate->linktype) {
7288 case DLT_ARCNET_LINUX:
7289 return gen_ahostop(cstate, abroadcast, Q_DST);
7291 case DLT_NETANALYZER:
7292 case DLT_NETANALYZER_TRANSPARENT:
7293 b1 = gen_prevlinkhdr_check(cstate);
7294 b0 = gen_ehostop(cstate, ebroadcast, Q_DST);
7299 return gen_fhostop(cstate, ebroadcast, Q_DST);
7301 return gen_thostop(cstate, ebroadcast, Q_DST);
7302 case DLT_IEEE802_11:
7303 case DLT_PRISM_HEADER:
7304 case DLT_IEEE802_11_RADIO_AVS:
7305 case DLT_IEEE802_11_RADIO:
7307 return gen_wlanhostop(cstate, ebroadcast, Q_DST);
7308 case DLT_IP_OVER_FC:
7309 return gen_ipfchostop(cstate, ebroadcast, Q_DST);
7311 bpf_error(cstate, "not a broadcast link");
7317 * We treat a netmask of PCAP_NETMASK_UNKNOWN (0xffffffff)
7318 * as an indication that we don't know the netmask, and fail
7321 if (cstate->netmask == PCAP_NETMASK_UNKNOWN)
7322 bpf_error(cstate, "netmask not known, so 'ip broadcast' not supported");
7323 b0 = gen_linktype(cstate, ETHERTYPE_IP);
7324 hostmask = ~cstate->netmask;
7325 b1 = gen_mcmp(cstate, OR_LINKPL, 16, BPF_W, (bpf_int32)0, hostmask);
7326 b2 = gen_mcmp(cstate, OR_LINKPL, 16, BPF_W,
7327 (bpf_int32)(~0 & hostmask), hostmask);
7332 bpf_error(cstate, "only link-layer/IP broadcast filters supported");
7338 * Generate code to test the low-order bit of a MAC address (that's
7339 * the bottom bit of the *first* byte).
7341 static struct block *
7342 gen_mac_multicast(compiler_state_t *cstate, int offset)
7344 register struct block *b0;
7345 register struct slist *s;
7347 /* link[offset] & 1 != 0 */
7348 s = gen_load_a(cstate, OR_LINKHDR, offset, BPF_B);
7349 b0 = new_block(cstate, JMP(BPF_JSET));
7356 gen_multicast(compiler_state_t *cstate, int proto)
7358 register struct block *b0, *b1, *b2;
7359 register struct slist *s;
7365 switch (cstate->linktype) {
7367 case DLT_ARCNET_LINUX:
7368 /* all ARCnet multicasts use the same address */
7369 return gen_ahostop(cstate, abroadcast, Q_DST);
7371 case DLT_NETANALYZER:
7372 case DLT_NETANALYZER_TRANSPARENT:
7373 b1 = gen_prevlinkhdr_check(cstate);
7374 /* ether[0] & 1 != 0 */
7375 b0 = gen_mac_multicast(cstate, 0);
7381 * XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX
7383 * XXX - was that referring to bit-order issues?
7385 /* fddi[1] & 1 != 0 */
7386 return gen_mac_multicast(cstate, 1);
7388 /* tr[2] & 1 != 0 */
7389 return gen_mac_multicast(cstate, 2);
7390 case DLT_IEEE802_11:
7391 case DLT_PRISM_HEADER:
7392 case DLT_IEEE802_11_RADIO_AVS:
7393 case DLT_IEEE802_11_RADIO:
7398 * For control frames, there is no DA.
7400 * For management frames, DA is at an
7401 * offset of 4 from the beginning of
7404 * For data frames, DA is at an offset
7405 * of 4 from the beginning of the packet
7406 * if To DS is clear and at an offset of
7407 * 16 from the beginning of the packet
7412 * Generate the tests to be done for data frames.
7414 * First, check for To DS set, i.e. "link[1] & 0x01".
7416 s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
7417 b1 = new_block(cstate, JMP(BPF_JSET));
7418 b1->s.k = 0x01; /* To DS */
7422 * If To DS is set, the DA is at 16.
7424 b0 = gen_mac_multicast(cstate, 16);
7428 * Now, check for To DS not set, i.e. check
7429 * "!(link[1] & 0x01)".
7431 s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
7432 b2 = new_block(cstate, JMP(BPF_JSET));
7433 b2->s.k = 0x01; /* To DS */
7438 * If To DS is not set, the DA is at 4.
7440 b1 = gen_mac_multicast(cstate, 4);
7444 * Now OR together the last two checks. That gives
7445 * the complete set of checks for data frames.
7450 * Now check for a data frame.
7451 * I.e, check "link[0] & 0x08".
7453 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
7454 b1 = new_block(cstate, JMP(BPF_JSET));
7459 * AND that with the checks done for data frames.
7464 * If the high-order bit of the type value is 0, this
7465 * is a management frame.
7466 * I.e, check "!(link[0] & 0x08)".
7468 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
7469 b2 = new_block(cstate, JMP(BPF_JSET));
7475 * For management frames, the DA is at 4.
7477 b1 = gen_mac_multicast(cstate, 4);
7481 * OR that with the checks done for data frames.
7482 * That gives the checks done for management and
7488 * If the low-order bit of the type value is 1,
7489 * this is either a control frame or a frame
7490 * with a reserved type, and thus not a
7493 * I.e., check "!(link[0] & 0x04)".
7495 s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
7496 b1 = new_block(cstate, JMP(BPF_JSET));
7502 * AND that with the checks for data and management
7507 case DLT_IP_OVER_FC:
7508 b0 = gen_mac_multicast(cstate, 2);
7513 /* Link not known to support multicasts */
7517 b0 = gen_linktype(cstate, ETHERTYPE_IP);
7518 b1 = gen_cmp_ge(cstate, OR_LINKPL, 16, BPF_B, (bpf_int32)224);
7523 b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
7524 b1 = gen_cmp(cstate, OR_LINKPL, 24, BPF_B, (bpf_int32)255);
7528 bpf_error(cstate, "link-layer multicast filters supported only on ethernet/FDDI/token ring/ARCNET/802.11/ATM LANE/Fibre Channel");
7534 * Filter on inbound (dir == 0) or outbound (dir == 1) traffic.
7535 * Outbound traffic is sent by this machine, while inbound traffic is
7536 * sent by a remote machine (and may include packets destined for a
7537 * unicast or multicast link-layer address we are not subscribing to).
7538 * These are the same definitions implemented by pcap_setdirection().
7539 * Capturing only unicast traffic destined for this host is probably
7540 * better accomplished using a higher-layer filter.
7543 gen_inbound(compiler_state_t *cstate, int dir)
7545 register struct block *b0;
7548 * Only some data link types support inbound/outbound qualifiers.
7550 switch (cstate->linktype) {
7552 b0 = gen_relation(cstate, BPF_JEQ,
7553 gen_load(cstate, Q_LINK, gen_loadi(cstate, 0), 1),
7554 gen_loadi(cstate, 0),
7560 /* match outgoing packets */
7561 b0 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, IPNET_OUTBOUND);
7563 /* match incoming packets */
7564 b0 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, IPNET_INBOUND);
7569 /* match outgoing packets */
7570 b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_H, LINUX_SLL_OUTGOING);
7572 /* to filter on inbound traffic, invert the match */
7577 #ifdef HAVE_NET_PFVAR_H
7579 b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, dir), BPF_B,
7580 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT));
7586 /* match outgoing packets */
7587 b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_B, PPP_PPPD_OUT);
7589 /* match incoming packets */
7590 b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_B, PPP_PPPD_IN);
7594 case DLT_JUNIPER_MFR:
7595 case DLT_JUNIPER_MLFR:
7596 case DLT_JUNIPER_MLPPP:
7597 case DLT_JUNIPER_ATM1:
7598 case DLT_JUNIPER_ATM2:
7599 case DLT_JUNIPER_PPPOE:
7600 case DLT_JUNIPER_PPPOE_ATM:
7601 case DLT_JUNIPER_GGSN:
7602 case DLT_JUNIPER_ES:
7603 case DLT_JUNIPER_MONITOR:
7604 case DLT_JUNIPER_SERVICES:
7605 case DLT_JUNIPER_ETHER:
7606 case DLT_JUNIPER_PPP:
7607 case DLT_JUNIPER_FRELAY:
7608 case DLT_JUNIPER_CHDLC:
7609 case DLT_JUNIPER_VP:
7610 case DLT_JUNIPER_ST:
7611 case DLT_JUNIPER_ISM:
7612 case DLT_JUNIPER_VS:
7613 case DLT_JUNIPER_SRX_E2E:
7614 case DLT_JUNIPER_FIBRECHANNEL:
7615 case DLT_JUNIPER_ATM_CEMIC:
7617 /* juniper flags (including direction) are stored
7618 * the byte after the 3-byte magic number */
7620 /* match outgoing packets */
7621 b0 = gen_mcmp(cstate, OR_LINKHDR, 3, BPF_B, 0, 0x01);
7623 /* match incoming packets */
7624 b0 = gen_mcmp(cstate, OR_LINKHDR, 3, BPF_B, 1, 0x01);
7630 * If we have packet meta-data indicating a direction,
7631 * check it, otherwise give up as this link-layer type
7632 * has nothing in the packet data.
7634 #if defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER)
7636 * This is Linux with PF_PACKET support.
7637 * If this is a *live* capture, we can look at
7638 * special meta-data in the filter expression;
7639 * if it's a savefile, we can't.
7641 if (cstate->bpf_pcap->rfile != NULL) {
7642 /* We have a FILE *, so this is a savefile */
7643 bpf_error(cstate, "inbound/outbound not supported on linktype %d when reading savefiles",
7648 /* match outgoing packets */
7649 b0 = gen_cmp(cstate, OR_LINKHDR, SKF_AD_OFF + SKF_AD_PKTTYPE, BPF_H,
7652 /* to filter on inbound traffic, invert the match */
7655 #else /* defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER) */
7656 bpf_error(cstate, "inbound/outbound not supported on linktype %d",
7660 #endif /* defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER) */
7665 #ifdef HAVE_NET_PFVAR_H
7666 /* PF firewall log matched interface */
7668 gen_pf_ifname(compiler_state_t *cstate, const char *ifname)
7673 if (cstate->linktype != DLT_PFLOG) {
7674 bpf_error(cstate, "ifname supported only on PF linktype");
7677 len = sizeof(((struct pfloghdr *)0)->ifname);
7678 off = offsetof(struct pfloghdr, ifname);
7679 if (strlen(ifname) >= len) {
7680 bpf_error(cstate, "ifname interface names can only be %d characters",
7684 b0 = gen_bcmp(cstate, OR_LINKHDR, off, strlen(ifname), (const u_char *)ifname);
7688 /* PF firewall log ruleset name */
7690 gen_pf_ruleset(compiler_state_t *cstate, char *ruleset)
7694 if (cstate->linktype != DLT_PFLOG) {
7695 bpf_error(cstate, "ruleset supported only on PF linktype");
7699 if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) {
7700 bpf_error(cstate, "ruleset names can only be %ld characters",
7701 (long)(sizeof(((struct pfloghdr *)0)->ruleset) - 1));
7705 b0 = gen_bcmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, ruleset),
7706 strlen(ruleset), (const u_char *)ruleset);
7710 /* PF firewall log rule number */
7712 gen_pf_rnr(compiler_state_t *cstate, int rnr)
7716 if (cstate->linktype != DLT_PFLOG) {
7717 bpf_error(cstate, "rnr supported only on PF linktype");
7721 b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, rulenr), BPF_W,
7726 /* PF firewall log sub-rule number */
7728 gen_pf_srnr(compiler_state_t *cstate, int srnr)
7732 if (cstate->linktype != DLT_PFLOG) {
7733 bpf_error(cstate, "srnr supported only on PF linktype");
7737 b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, subrulenr), BPF_W,
7742 /* PF firewall log reason code */
7744 gen_pf_reason(compiler_state_t *cstate, int reason)
7748 if (cstate->linktype != DLT_PFLOG) {
7749 bpf_error(cstate, "reason supported only on PF linktype");
7753 b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, reason), BPF_B,
7758 /* PF firewall log action */
7760 gen_pf_action(compiler_state_t *cstate, int action)
7764 if (cstate->linktype != DLT_PFLOG) {
7765 bpf_error(cstate, "action supported only on PF linktype");
7769 b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, action), BPF_B,
7773 #else /* !HAVE_NET_PFVAR_H */
7775 gen_pf_ifname(compiler_state_t *cstate, const char *ifname)
7777 bpf_error(cstate, "libpcap was compiled without pf support");
7783 gen_pf_ruleset(compiler_state_t *cstate, char *ruleset)
7785 bpf_error(cstate, "libpcap was compiled on a machine without pf support");
7791 gen_pf_rnr(compiler_state_t *cstate, int rnr)
7793 bpf_error(cstate, "libpcap was compiled on a machine without pf support");
7799 gen_pf_srnr(compiler_state_t *cstate, int srnr)
7801 bpf_error(cstate, "libpcap was compiled on a machine without pf support");
7807 gen_pf_reason(compiler_state_t *cstate, int reason)
7809 bpf_error(cstate, "libpcap was compiled on a machine without pf support");
7815 gen_pf_action(compiler_state_t *cstate, int action)
7817 bpf_error(cstate, "libpcap was compiled on a machine without pf support");
7821 #endif /* HAVE_NET_PFVAR_H */
7823 /* IEEE 802.11 wireless header */
7825 gen_p80211_type(compiler_state_t *cstate, int type, int mask)
7829 switch (cstate->linktype) {
7831 case DLT_IEEE802_11:
7832 case DLT_PRISM_HEADER:
7833 case DLT_IEEE802_11_RADIO_AVS:
7834 case DLT_IEEE802_11_RADIO:
7835 b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, (bpf_int32)type,
7840 bpf_error(cstate, "802.11 link-layer types supported only on 802.11");
7848 gen_p80211_fcdir(compiler_state_t *cstate, int fcdir)
7852 switch (cstate->linktype) {
7854 case DLT_IEEE802_11:
7855 case DLT_PRISM_HEADER:
7856 case DLT_IEEE802_11_RADIO_AVS:
7857 case DLT_IEEE802_11_RADIO:
7861 bpf_error(cstate, "frame direction supported only with 802.11 headers");
7865 b0 = gen_mcmp(cstate, OR_LINKHDR, 1, BPF_B, (bpf_int32)fcdir,
7866 (bpf_u_int32)IEEE80211_FC1_DIR_MASK);
7872 gen_acode(compiler_state_t *cstate, const u_char *eaddr, struct qual q)
7874 switch (cstate->linktype) {
7877 case DLT_ARCNET_LINUX:
7878 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) &&
7880 return (gen_ahostop(cstate, eaddr, (int)q.dir));
7882 bpf_error(cstate, "ARCnet address used in non-arc expression");
7888 bpf_error(cstate, "aid supported only on ARCnet");
7891 bpf_error(cstate, "ARCnet address used in non-arc expression");
7896 static struct block *
7897 gen_ahostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
7899 register struct block *b0, *b1;
7902 /* src comes first, different from Ethernet */
7904 return gen_bcmp(cstate, OR_LINKHDR, 0, 1, eaddr);
7907 return gen_bcmp(cstate, OR_LINKHDR, 1, 1, eaddr);
7910 b0 = gen_ahostop(cstate, eaddr, Q_SRC);
7911 b1 = gen_ahostop(cstate, eaddr, Q_DST);
7917 b0 = gen_ahostop(cstate, eaddr, Q_SRC);
7918 b1 = gen_ahostop(cstate, eaddr, Q_DST);
7923 bpf_error(cstate, "'addr1' is only supported on 802.11");
7927 bpf_error(cstate, "'addr2' is only supported on 802.11");
7931 bpf_error(cstate, "'addr3' is only supported on 802.11");
7935 bpf_error(cstate, "'addr4' is only supported on 802.11");
7939 bpf_error(cstate, "'ra' is only supported on 802.11");
7943 bpf_error(cstate, "'ta' is only supported on 802.11");
7950 #if defined(SKF_AD_VLAN_TAG) && defined(SKF_AD_VLAN_TAG_PRESENT)
7951 static struct block *
7952 gen_vlan_bpf_extensions(compiler_state_t *cstate, int vlan_num)
7954 struct block *b0, *b1;
7957 /* generate new filter code based on extracting packet
7959 s = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
7960 s->s.k = SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT;
7962 b0 = new_block(cstate, JMP(BPF_JEQ));
7966 if (vlan_num >= 0) {
7967 s = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
7968 s->s.k = SKF_AD_OFF + SKF_AD_VLAN_TAG;
7970 b1 = new_block(cstate, JMP(BPF_JEQ));
7972 b1->s.k = (bpf_int32) vlan_num;
7982 static struct block *
7983 gen_vlan_no_bpf_extensions(compiler_state_t *cstate, int vlan_num)
7985 struct block *b0, *b1;
7987 /* check for VLAN, including QinQ */
7988 b0 = gen_linktype(cstate, ETHERTYPE_8021Q);
7989 b1 = gen_linktype(cstate, ETHERTYPE_8021AD);
7992 b1 = gen_linktype(cstate, ETHERTYPE_8021QINQ);
7996 /* If a specific VLAN is requested, check VLAN id */
7997 if (vlan_num >= 0) {
7998 b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_H,
7999 (bpf_int32)vlan_num, 0x0fff);
8005 * The payload follows the full header, including the
8006 * VLAN tags, so skip past this VLAN tag.
8008 cstate->off_linkpl.constant_part += 4;
8011 * The link-layer type information follows the VLAN tags, so
8012 * skip past this VLAN tag.
8014 cstate->off_linktype.constant_part += 4;
8020 * support IEEE 802.1Q VLAN trunk over ethernet
8023 gen_vlan(compiler_state_t *cstate, int vlan_num)
8027 /* can't check for VLAN-encapsulated packets inside MPLS */
8028 if (cstate->label_stack_depth > 0)
8029 bpf_error(cstate, "no VLAN match after MPLS");
8032 * Check for a VLAN packet, and then change the offsets to point
8033 * to the type and data fields within the VLAN packet. Just
8034 * increment the offsets, so that we can support a hierarchy, e.g.
8035 * "vlan 300 && vlan 200" to capture VLAN 200 encapsulated within
8038 * XXX - this is a bit of a kludge. If we were to split the
8039 * compiler into a parser that parses an expression and
8040 * generates an expression tree, and a code generator that
8041 * takes an expression tree (which could come from our
8042 * parser or from some other parser) and generates BPF code,
8043 * we could perhaps make the offsets parameters of routines
8044 * and, in the handler for an "AND" node, pass to subnodes
8045 * other than the VLAN node the adjusted offsets.
8047 * This would mean that "vlan" would, instead of changing the
8048 * behavior of *all* tests after it, change only the behavior
8049 * of tests ANDed with it. That would change the documented
8050 * semantics of "vlan", which might break some expressions.
8051 * However, it would mean that "(vlan and ip) or ip" would check
8052 * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than
8053 * checking only for VLAN-encapsulated IP, so that could still
8054 * be considered worth doing; it wouldn't break expressions
8055 * that are of the form "vlan and ..." or "vlan N and ...",
8056 * which I suspect are the most common expressions involving
8057 * "vlan". "vlan or ..." doesn't necessarily do what the user
8058 * would really want, now, as all the "or ..." tests would
8059 * be done assuming a VLAN, even though the "or" could be viewed
8060 * as meaning "or, if this isn't a VLAN packet...".
8062 switch (cstate->linktype) {
8065 case DLT_NETANALYZER:
8066 case DLT_NETANALYZER_TRANSPARENT:
8067 #if defined(SKF_AD_VLAN_TAG) && defined(SKF_AD_VLAN_TAG_PRESENT)
8068 /* Verify that this is the outer part of the packet and
8069 * not encapsulated somehow. */
8070 if (cstate->vlan_stack_depth == 0 && !cstate->off_linkhdr.is_variable &&
8071 cstate->off_linkhdr.constant_part ==
8072 cstate->off_outermostlinkhdr.constant_part) {
8074 * Do we need special VLAN handling?
8076 if (cstate->bpf_pcap->bpf_codegen_flags & BPF_SPECIAL_VLAN_HANDLING)
8077 b0 = gen_vlan_bpf_extensions(cstate, vlan_num);
8079 b0 = gen_vlan_no_bpf_extensions(cstate, vlan_num);
8082 b0 = gen_vlan_no_bpf_extensions(cstate, vlan_num);
8085 case DLT_IEEE802_11:
8086 case DLT_PRISM_HEADER:
8087 case DLT_IEEE802_11_RADIO_AVS:
8088 case DLT_IEEE802_11_RADIO:
8089 b0 = gen_vlan_no_bpf_extensions(cstate, vlan_num);
8093 bpf_error(cstate, "no VLAN support for data link type %d",
8098 cstate->vlan_stack_depth++;
8107 gen_mpls(compiler_state_t *cstate, int label_num)
8109 struct block *b0, *b1;
8111 if (cstate->label_stack_depth > 0) {
8112 /* just match the bottom-of-stack bit clear */
8113 b0 = gen_mcmp(cstate, OR_PREVMPLSHDR, 2, BPF_B, 0, 0x01);
8116 * We're not in an MPLS stack yet, so check the link-layer
8117 * type against MPLS.
8119 switch (cstate->linktype) {
8121 case DLT_C_HDLC: /* fall through */
8123 case DLT_NETANALYZER:
8124 case DLT_NETANALYZER_TRANSPARENT:
8125 b0 = gen_linktype(cstate, ETHERTYPE_MPLS);
8129 b0 = gen_linktype(cstate, PPP_MPLS_UCAST);
8132 /* FIXME add other DLT_s ...
8133 * for Frame-Relay/and ATM this may get messy due to SNAP headers
8134 * leave it for now */
8137 bpf_error(cstate, "no MPLS support for data link type %d",
8145 /* If a specific MPLS label is requested, check it */
8146 if (label_num >= 0) {
8147 label_num = label_num << 12; /* label is shifted 12 bits on the wire */
8148 b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_W, (bpf_int32)label_num,
8149 0xfffff000); /* only compare the first 20 bits */
8155 * Change the offsets to point to the type and data fields within
8156 * the MPLS packet. Just increment the offsets, so that we
8157 * can support a hierarchy, e.g. "mpls 100000 && mpls 1024" to
8158 * capture packets with an outer label of 100000 and an inner
8161 * Increment the MPLS stack depth as well; this indicates that
8162 * we're checking MPLS-encapsulated headers, to make sure higher
8163 * level code generators don't try to match against IP-related
8164 * protocols such as Q_ARP, Q_RARP etc.
8166 * XXX - this is a bit of a kludge. See comments in gen_vlan().
8168 cstate->off_nl_nosnap += 4;
8169 cstate->off_nl += 4;
8170 cstate->label_stack_depth++;
8175 * Support PPPOE discovery and session.
8178 gen_pppoed(compiler_state_t *cstate)
8180 /* check for PPPoE discovery */
8181 return gen_linktype(cstate, (bpf_int32)ETHERTYPE_PPPOED);
8185 gen_pppoes(compiler_state_t *cstate, int sess_num)
8187 struct block *b0, *b1;
8190 * Test against the PPPoE session link-layer type.
8192 b0 = gen_linktype(cstate, (bpf_int32)ETHERTYPE_PPPOES);
8194 /* If a specific session is requested, check PPPoE session id */
8195 if (sess_num >= 0) {
8196 b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_W,
8197 (bpf_int32)sess_num, 0x0000ffff);
8203 * Change the offsets to point to the type and data fields within
8204 * the PPP packet, and note that this is PPPoE rather than
8207 * XXX - this is a bit of a kludge. If we were to split the
8208 * compiler into a parser that parses an expression and
8209 * generates an expression tree, and a code generator that
8210 * takes an expression tree (which could come from our
8211 * parser or from some other parser) and generates BPF code,
8212 * we could perhaps make the offsets parameters of routines
8213 * and, in the handler for an "AND" node, pass to subnodes
8214 * other than the PPPoE node the adjusted offsets.
8216 * This would mean that "pppoes" would, instead of changing the
8217 * behavior of *all* tests after it, change only the behavior
8218 * of tests ANDed with it. That would change the documented
8219 * semantics of "pppoes", which might break some expressions.
8220 * However, it would mean that "(pppoes and ip) or ip" would check
8221 * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than
8222 * checking only for VLAN-encapsulated IP, so that could still
8223 * be considered worth doing; it wouldn't break expressions
8224 * that are of the form "pppoes and ..." which I suspect are the
8225 * most common expressions involving "pppoes". "pppoes or ..."
8226 * doesn't necessarily do what the user would really want, now,
8227 * as all the "or ..." tests would be done assuming PPPoE, even
8228 * though the "or" could be viewed as meaning "or, if this isn't
8229 * a PPPoE packet...".
8231 * The "network-layer" protocol is PPPoE, which has a 6-byte
8232 * PPPoE header, followed by a PPP packet.
8234 * There is no HDLC encapsulation for the PPP packet (it's
8235 * encapsulated in PPPoES instead), so the link-layer type
8236 * starts at the first byte of the PPP packet. For PPPoE,
8237 * that offset is relative to the beginning of the total
8238 * link-layer payload, including any 802.2 LLC header, so
8239 * it's 6 bytes past cstate->off_nl.
8241 PUSH_LINKHDR(cstate, DLT_PPP, cstate->off_linkpl.is_variable,
8242 cstate->off_linkpl.constant_part + cstate->off_nl + 6, /* 6 bytes past the PPPoE header */
8243 cstate->off_linkpl.reg);
8245 cstate->off_linktype = cstate->off_linkhdr;
8246 cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 2;
8249 cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
8254 /* Check that this is Geneve and the VNI is correct if
8255 * specified. Parameterized to handle both IPv4 and IPv6. */
8256 static struct block *
8257 gen_geneve_check(compiler_state_t *cstate,
8258 struct block *(*gen_portfn)(compiler_state_t *, int, int, int),
8259 enum e_offrel offrel, int vni)
8261 struct block *b0, *b1;
8263 b0 = gen_portfn(cstate, GENEVE_PORT, IPPROTO_UDP, Q_DST);
8265 /* Check that we are operating on version 0. Otherwise, we
8266 * can't decode the rest of the fields. The version is 2 bits
8267 * in the first byte of the Geneve header. */
8268 b1 = gen_mcmp(cstate, offrel, 8, BPF_B, (bpf_int32)0, 0xc0);
8273 vni <<= 8; /* VNI is in the upper 3 bytes */
8274 b1 = gen_mcmp(cstate, offrel, 12, BPF_W, (bpf_int32)vni,
8283 /* The IPv4 and IPv6 Geneve checks need to do two things:
8284 * - Verify that this actually is Geneve with the right VNI.
8285 * - Place the IP header length (plus variable link prefix if
8286 * needed) into register A to be used later to compute
8287 * the inner packet offsets. */
8288 static struct block *
8289 gen_geneve4(compiler_state_t *cstate, int vni)
8291 struct block *b0, *b1;
8292 struct slist *s, *s1;
8294 b0 = gen_geneve_check(cstate, gen_port, OR_TRAN_IPV4, vni);
8296 /* Load the IP header length into A. */
8297 s = gen_loadx_iphdrlen(cstate);
8299 s1 = new_stmt(cstate, BPF_MISC|BPF_TXA);
8302 /* Forcibly append these statements to the true condition
8303 * of the protocol check by creating a new block that is
8304 * always true and ANDing them. */
8305 b1 = new_block(cstate, BPF_JMP|BPF_JEQ|BPF_X);
8314 static struct block *
8315 gen_geneve6(compiler_state_t *cstate, int vni)
8317 struct block *b0, *b1;
8318 struct slist *s, *s1;
8320 b0 = gen_geneve_check(cstate, gen_port6, OR_TRAN_IPV6, vni);
8322 /* Load the IP header length. We need to account for a
8323 * variable length link prefix if there is one. */
8324 s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl);
8326 s1 = new_stmt(cstate, BPF_LD|BPF_IMM);
8330 s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X);
8334 s = new_stmt(cstate, BPF_LD|BPF_IMM);
8338 /* Forcibly append these statements to the true condition
8339 * of the protocol check by creating a new block that is
8340 * always true and ANDing them. */
8341 s1 = new_stmt(cstate, BPF_MISC|BPF_TAX);
8344 b1 = new_block(cstate, BPF_JMP|BPF_JEQ|BPF_X);
8353 /* We need to store three values based on the Geneve header::
8354 * - The offset of the linktype.
8355 * - The offset of the end of the Geneve header.
8356 * - The offset of the end of the encapsulated MAC header. */
8357 static struct slist *
8358 gen_geneve_offsets(compiler_state_t *cstate)
8360 struct slist *s, *s1, *s_proto;
8362 /* First we need to calculate the offset of the Geneve header
8363 * itself. This is composed of the IP header previously calculated
8364 * (include any variable link prefix) and stored in A plus the
8365 * fixed sized headers (fixed link prefix, MAC length, and UDP
8367 s = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
8368 s->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 8;
8370 /* Stash this in X since we'll need it later. */
8371 s1 = new_stmt(cstate, BPF_MISC|BPF_TAX);
8374 /* The EtherType in Geneve is 2 bytes in. Calculate this and
8376 s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
8380 cstate->off_linktype.reg = alloc_reg(cstate);
8381 cstate->off_linktype.is_variable = 1;
8382 cstate->off_linktype.constant_part = 0;
8384 s1 = new_stmt(cstate, BPF_ST);
8385 s1->s.k = cstate->off_linktype.reg;
8388 /* Load the Geneve option length and mask and shift to get the
8389 * number of bytes. It is stored in the first byte of the Geneve
8391 s1 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
8395 s1 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
8399 s1 = new_stmt(cstate, BPF_ALU|BPF_MUL|BPF_K);
8403 /* Add in the rest of the Geneve base header. */
8404 s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
8408 /* Add the Geneve header length to its offset and store. */
8409 s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X);
8413 /* Set the encapsulated type as Ethernet. Even though we may
8414 * not actually have Ethernet inside there are two reasons this
8416 * - The linktype field is always in EtherType format regardless
8417 * of whether it is in Geneve or an inner Ethernet frame.
8418 * - The only link layer that we have specific support for is
8419 * Ethernet. We will confirm that the packet actually is
8420 * Ethernet at runtime before executing these checks. */
8421 PUSH_LINKHDR(cstate, DLT_EN10MB, 1, 0, alloc_reg(cstate));
8423 s1 = new_stmt(cstate, BPF_ST);
8424 s1->s.k = cstate->off_linkhdr.reg;
8427 /* Calculate whether we have an Ethernet header or just raw IP/
8428 * MPLS/etc. If we have Ethernet, advance the end of the MAC offset
8429 * and linktype by 14 bytes so that the network header can be found
8430 * seamlessly. Otherwise, keep what we've calculated already. */
8432 /* We have a bare jmp so we can't use the optimizer. */
8433 cstate->no_optimize = 1;
8435 /* Load the EtherType in the Geneve header, 2 bytes in. */
8436 s1 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_H);
8440 /* Load X with the end of the Geneve header. */
8441 s1 = new_stmt(cstate, BPF_LDX|BPF_MEM);
8442 s1->s.k = cstate->off_linkhdr.reg;
8445 /* Check if the EtherType is Transparent Ethernet Bridging. At the
8446 * end of this check, we should have the total length in X. In
8447 * the non-Ethernet case, it's already there. */
8448 s_proto = new_stmt(cstate, JMP(BPF_JEQ));
8449 s_proto->s.k = ETHERTYPE_TEB;
8450 sappend(s, s_proto);
8452 s1 = new_stmt(cstate, BPF_MISC|BPF_TXA);
8456 /* Since this is Ethernet, use the EtherType of the payload
8457 * directly as the linktype. Overwrite what we already have. */
8458 s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
8462 s1 = new_stmt(cstate, BPF_ST);
8463 s1->s.k = cstate->off_linktype.reg;
8466 /* Advance two bytes further to get the end of the Ethernet
8468 s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
8472 /* Move the result to X. */
8473 s1 = new_stmt(cstate, BPF_MISC|BPF_TAX);
8476 /* Store the final result of our linkpl calculation. */
8477 cstate->off_linkpl.reg = alloc_reg(cstate);
8478 cstate->off_linkpl.is_variable = 1;
8479 cstate->off_linkpl.constant_part = 0;
8481 s1 = new_stmt(cstate, BPF_STX);
8482 s1->s.k = cstate->off_linkpl.reg;
8491 /* Check to see if this is a Geneve packet. */
8493 gen_geneve(compiler_state_t *cstate, int vni)
8495 struct block *b0, *b1;
8498 b0 = gen_geneve4(cstate, vni);
8499 b1 = gen_geneve6(cstate, vni);
8504 /* Later filters should act on the payload of the Geneve frame,
8505 * update all of the header pointers. Attach this code so that
8506 * it gets executed in the event that the Geneve filter matches. */
8507 s = gen_geneve_offsets(cstate);
8509 b1 = gen_true(cstate);
8510 sappend(s, b1->stmts);
8515 cstate->is_geneve = 1;
8520 /* Check that the encapsulated frame has a link layer header
8521 * for Ethernet filters. */
8522 static struct block *
8523 gen_geneve_ll_check(compiler_state_t *cstate)
8526 struct slist *s, *s1;
8528 /* The easiest way to see if there is a link layer present
8529 * is to check if the link layer header and payload are not
8532 /* Geneve always generates pure variable offsets so we can
8533 * compare only the registers. */
8534 s = new_stmt(cstate, BPF_LD|BPF_MEM);
8535 s->s.k = cstate->off_linkhdr.reg;
8537 s1 = new_stmt(cstate, BPF_LDX|BPF_MEM);
8538 s1->s.k = cstate->off_linkpl.reg;
8541 b0 = new_block(cstate, BPF_JMP|BPF_JEQ|BPF_X);
8550 gen_atmfield_code(compiler_state_t *cstate, int atmfield, bpf_int32 jvalue,
8551 bpf_u_int32 jtype, int reverse)
8558 if (!cstate->is_atm)
8559 bpf_error(cstate, "'vpi' supported only on raw ATM");
8560 if (cstate->off_vpi == (u_int)-1)
8562 b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_vpi, BPF_B, 0xffffffff, jtype,
8567 if (!cstate->is_atm)
8568 bpf_error(cstate, "'vci' supported only on raw ATM");
8569 if (cstate->off_vci == (u_int)-1)
8571 b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_vci, BPF_H, 0xffffffff, jtype,
8576 if (cstate->off_proto == (u_int)-1)
8577 abort(); /* XXX - this isn't on FreeBSD */
8578 b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_proto, BPF_B, 0x0f, jtype,
8583 if (cstate->off_payload == (u_int)-1)
8585 b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_payload + MSG_TYPE_POS, BPF_B,
8586 0xffffffff, jtype, reverse, jvalue);
8590 if (!cstate->is_atm)
8591 bpf_error(cstate, "'callref' supported only on raw ATM");
8592 if (cstate->off_proto == (u_int)-1)
8594 b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_proto, BPF_B, 0xffffffff,
8595 jtype, reverse, jvalue);
8605 gen_atmtype_abbrev(compiler_state_t *cstate, int type)
8607 struct block *b0, *b1;
8612 /* Get all packets in Meta signalling Circuit */
8613 if (!cstate->is_atm)
8614 bpf_error(cstate, "'metac' supported only on raw ATM");
8615 b0 = gen_atmfield_code(cstate, A_VPI, 0, BPF_JEQ, 0);
8616 b1 = gen_atmfield_code(cstate, A_VCI, 1, BPF_JEQ, 0);
8621 /* Get all packets in Broadcast Circuit*/
8622 if (!cstate->is_atm)
8623 bpf_error(cstate, "'bcc' supported only on raw ATM");
8624 b0 = gen_atmfield_code(cstate, A_VPI, 0, BPF_JEQ, 0);
8625 b1 = gen_atmfield_code(cstate, A_VCI, 2, BPF_JEQ, 0);
8630 /* Get all cells in Segment OAM F4 circuit*/
8631 if (!cstate->is_atm)
8632 bpf_error(cstate, "'oam4sc' supported only on raw ATM");
8633 b0 = gen_atmfield_code(cstate, A_VPI, 0, BPF_JEQ, 0);
8634 b1 = gen_atmfield_code(cstate, A_VCI, 3, BPF_JEQ, 0);
8639 /* Get all cells in End-to-End OAM F4 Circuit*/
8640 if (!cstate->is_atm)
8641 bpf_error(cstate, "'oam4ec' supported only on raw ATM");
8642 b0 = gen_atmfield_code(cstate, A_VPI, 0, BPF_JEQ, 0);
8643 b1 = gen_atmfield_code(cstate, A_VCI, 4, BPF_JEQ, 0);
8648 /* Get all packets in connection Signalling Circuit */
8649 if (!cstate->is_atm)
8650 bpf_error(cstate, "'sc' supported only on raw ATM");
8651 b0 = gen_atmfield_code(cstate, A_VPI, 0, BPF_JEQ, 0);
8652 b1 = gen_atmfield_code(cstate, A_VCI, 5, BPF_JEQ, 0);
8657 /* Get all packets in ILMI Circuit */
8658 if (!cstate->is_atm)
8659 bpf_error(cstate, "'ilmic' supported only on raw ATM");
8660 b0 = gen_atmfield_code(cstate, A_VPI, 0, BPF_JEQ, 0);
8661 b1 = gen_atmfield_code(cstate, A_VCI, 16, BPF_JEQ, 0);
8666 /* Get all LANE packets */
8667 if (!cstate->is_atm)
8668 bpf_error(cstate, "'lane' supported only on raw ATM");
8669 b1 = gen_atmfield_code(cstate, A_PROTOTYPE, PT_LANE, BPF_JEQ, 0);
8672 * Arrange that all subsequent tests assume LANE
8673 * rather than LLC-encapsulated packets, and set
8674 * the offsets appropriately for LANE-encapsulated
8677 * We assume LANE means Ethernet, not Token Ring.
8679 PUSH_LINKHDR(cstate, DLT_EN10MB, 0,
8680 cstate->off_payload + 2, /* Ethernet header */
8682 cstate->off_linktype.constant_part = cstate->off_linkhdr.constant_part + 12;
8683 cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 14; /* Ethernet */
8684 cstate->off_nl = 0; /* Ethernet II */
8685 cstate->off_nl_nosnap = 3; /* 802.3+802.2 */
8689 /* Get all LLC-encapsulated packets */
8690 if (!cstate->is_atm)
8691 bpf_error(cstate, "'llc' supported only on raw ATM");
8692 b1 = gen_atmfield_code(cstate, A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
8693 cstate->linktype = cstate->prevlinktype;
8703 * Filtering for MTP2 messages based on li value
8704 * FISU, length is null
8705 * LSSU, length is 1 or 2
8706 * MSU, length is 3 or more
8707 * For MTP2_HSL, sequences are on 2 bytes, and length on 9 bits
8710 gen_mtp2type_abbrev(compiler_state_t *cstate, int type)
8712 struct block *b0, *b1;
8717 if ( (cstate->linktype != DLT_MTP2) &&
8718 (cstate->linktype != DLT_ERF) &&
8719 (cstate->linktype != DLT_MTP2_WITH_PHDR) )
8720 bpf_error(cstate, "'fisu' supported only on MTP2");
8721 /* gen_ncmp(cstate, offrel, offset, size, mask, jtype, reverse, value) */
8722 b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JEQ, 0, 0);
8726 if ( (cstate->linktype != DLT_MTP2) &&
8727 (cstate->linktype != DLT_ERF) &&
8728 (cstate->linktype != DLT_MTP2_WITH_PHDR) )
8729 bpf_error(cstate, "'lssu' supported only on MTP2");
8730 b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JGT, 1, 2);
8731 b1 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JGT, 0, 0);
8736 if ( (cstate->linktype != DLT_MTP2) &&
8737 (cstate->linktype != DLT_ERF) &&
8738 (cstate->linktype != DLT_MTP2_WITH_PHDR) )
8739 bpf_error(cstate, "'msu' supported only on MTP2");
8740 b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JGT, 0, 2);
8744 if ( (cstate->linktype != DLT_MTP2) &&
8745 (cstate->linktype != DLT_ERF) &&
8746 (cstate->linktype != DLT_MTP2_WITH_PHDR) )
8747 bpf_error(cstate, "'hfisu' supported only on MTP2_HSL");
8748 /* gen_ncmp(cstate, offrel, offset, size, mask, jtype, reverse, value) */
8749 b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JEQ, 0, 0);
8753 if ( (cstate->linktype != DLT_MTP2) &&
8754 (cstate->linktype != DLT_ERF) &&
8755 (cstate->linktype != DLT_MTP2_WITH_PHDR) )
8756 bpf_error(cstate, "'hlssu' supported only on MTP2_HSL");
8757 b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JGT, 1, 0x0100);
8758 b1 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JGT, 0, 0);
8763 if ( (cstate->linktype != DLT_MTP2) &&
8764 (cstate->linktype != DLT_ERF) &&
8765 (cstate->linktype != DLT_MTP2_WITH_PHDR) )
8766 bpf_error(cstate, "'hmsu' supported only on MTP2_HSL");
8767 b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JGT, 0, 0x0100);
8777 gen_mtp3field_code(compiler_state_t *cstate, int mtp3field, bpf_u_int32 jvalue,
8778 bpf_u_int32 jtype, int reverse)
8781 bpf_u_int32 val1 , val2 , val3;
8782 u_int newoff_sio = cstate->off_sio;
8783 u_int newoff_opc = cstate->off_opc;
8784 u_int newoff_dpc = cstate->off_dpc;
8785 u_int newoff_sls = cstate->off_sls;
8787 switch (mtp3field) {
8790 newoff_sio += 3; /* offset for MTP2_HSL */
8794 if (cstate->off_sio == (u_int)-1)
8795 bpf_error(cstate, "'sio' supported only on SS7");
8796 /* sio coded on 1 byte so max value 255 */
8798 bpf_error(cstate, "sio value %u too big; max value = 255",
8800 b0 = gen_ncmp(cstate, OR_PACKET, newoff_sio, BPF_B, 0xffffffff,
8801 (u_int)jtype, reverse, (u_int)jvalue);
8807 if (cstate->off_opc == (u_int)-1)
8808 bpf_error(cstate, "'opc' supported only on SS7");
8809 /* opc coded on 14 bits so max value 16383 */
8811 bpf_error(cstate, "opc value %u too big; max value = 16383",
8813 /* the following instructions are made to convert jvalue
8814 * to the form used to write opc in an ss7 message*/
8815 val1 = jvalue & 0x00003c00;
8817 val2 = jvalue & 0x000003fc;
8819 val3 = jvalue & 0x00000003;
8821 jvalue = val1 + val2 + val3;
8822 b0 = gen_ncmp(cstate, OR_PACKET, newoff_opc, BPF_W, 0x00c0ff0f,
8823 (u_int)jtype, reverse, (u_int)jvalue);
8831 if (cstate->off_dpc == (u_int)-1)
8832 bpf_error(cstate, "'dpc' supported only on SS7");
8833 /* dpc coded on 14 bits so max value 16383 */
8835 bpf_error(cstate, "dpc value %u too big; max value = 16383",
8837 /* the following instructions are made to convert jvalue
8838 * to the forme used to write dpc in an ss7 message*/
8839 val1 = jvalue & 0x000000ff;
8841 val2 = jvalue & 0x00003f00;
8843 jvalue = val1 + val2;
8844 b0 = gen_ncmp(cstate, OR_PACKET, newoff_dpc, BPF_W, 0xff3f0000,
8845 (u_int)jtype, reverse, (u_int)jvalue);
8851 if (cstate->off_sls == (u_int)-1)
8852 bpf_error(cstate, "'sls' supported only on SS7");
8853 /* sls coded on 4 bits so max value 15 */
8855 bpf_error(cstate, "sls value %u too big; max value = 15",
8857 /* the following instruction is made to convert jvalue
8858 * to the forme used to write sls in an ss7 message*/
8859 jvalue = jvalue << 4;
8860 b0 = gen_ncmp(cstate, OR_PACKET, newoff_sls, BPF_B, 0xf0,
8861 (u_int)jtype,reverse, (u_int)jvalue);
8870 static struct block *
8871 gen_msg_abbrev(compiler_state_t *cstate, int type)
8876 * Q.2931 signalling protocol messages for handling virtual circuits
8877 * establishment and teardown
8882 b1 = gen_atmfield_code(cstate, A_MSGTYPE, SETUP, BPF_JEQ, 0);
8886 b1 = gen_atmfield_code(cstate, A_MSGTYPE, CALL_PROCEED, BPF_JEQ, 0);
8890 b1 = gen_atmfield_code(cstate, A_MSGTYPE, CONNECT, BPF_JEQ, 0);
8894 b1 = gen_atmfield_code(cstate, A_MSGTYPE, CONNECT_ACK, BPF_JEQ, 0);
8898 b1 = gen_atmfield_code(cstate, A_MSGTYPE, RELEASE, BPF_JEQ, 0);
8901 case A_RELEASE_DONE:
8902 b1 = gen_atmfield_code(cstate, A_MSGTYPE, RELEASE_DONE, BPF_JEQ, 0);
8912 gen_atmmulti_abbrev(compiler_state_t *cstate, int type)
8914 struct block *b0, *b1;
8919 if (!cstate->is_atm)
8920 bpf_error(cstate, "'oam' supported only on raw ATM");
8921 b1 = gen_atmmulti_abbrev(cstate, A_OAMF4);
8925 if (!cstate->is_atm)
8926 bpf_error(cstate, "'oamf4' supported only on raw ATM");
8928 b0 = gen_atmfield_code(cstate, A_VCI, 3, BPF_JEQ, 0);
8929 b1 = gen_atmfield_code(cstate, A_VCI, 4, BPF_JEQ, 0);
8931 b0 = gen_atmfield_code(cstate, A_VPI, 0, BPF_JEQ, 0);
8937 * Get Q.2931 signalling messages for switched
8938 * virtual connection
8940 if (!cstate->is_atm)
8941 bpf_error(cstate, "'connectmsg' supported only on raw ATM");
8942 b0 = gen_msg_abbrev(cstate, A_SETUP);
8943 b1 = gen_msg_abbrev(cstate, A_CALLPROCEED);
8945 b0 = gen_msg_abbrev(cstate, A_CONNECT);
8947 b0 = gen_msg_abbrev(cstate, A_CONNECTACK);
8949 b0 = gen_msg_abbrev(cstate, A_RELEASE);
8951 b0 = gen_msg_abbrev(cstate, A_RELEASE_DONE);
8953 b0 = gen_atmtype_abbrev(cstate, A_SC);
8958 if (!cstate->is_atm)
8959 bpf_error(cstate, "'metaconnect' supported only on raw ATM");
8960 b0 = gen_msg_abbrev(cstate, A_SETUP);
8961 b1 = gen_msg_abbrev(cstate, A_CALLPROCEED);
8963 b0 = gen_msg_abbrev(cstate, A_CONNECT);
8965 b0 = gen_msg_abbrev(cstate, A_RELEASE);
8967 b0 = gen_msg_abbrev(cstate, A_RELEASE_DONE);
8969 b0 = gen_atmtype_abbrev(cstate, A_METAC);