2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
5 * This code is derived from software contributed to The DragonFly Project
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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12 * notice, this list of conditions and the following disclaimer.
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15 * documentation and/or other materials provided with the distribution.
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17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
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63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
67 * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.52 2003/03/07 07:01:28 silby Exp $
72 #include "opt_bootp.h"
74 #include "opt_ipdivert.h"
75 #include "opt_ipstealth.h"
76 #include "opt_ipsec.h"
79 #include <sys/param.h>
80 #include <sys/systm.h>
82 #include <sys/malloc.h>
83 #include <sys/mpipe.h>
84 #include <sys/domain.h>
85 #include <sys/protosw.h>
86 #include <sys/socket.h>
88 #include <sys/globaldata.h>
89 #include <sys/thread.h>
90 #include <sys/kernel.h>
91 #include <sys/syslog.h>
92 #include <sys/sysctl.h>
93 #include <sys/in_cksum.h>
96 #include <sys/mplock2.h>
98 #include <machine/stdarg.h>
101 #include <net/if_types.h>
102 #include <net/if_var.h>
103 #include <net/if_dl.h>
104 #include <net/pfil.h>
105 #include <net/route.h>
106 #include <net/netisr.h>
108 #include <netinet/in.h>
109 #include <netinet/in_systm.h>
110 #include <netinet/in_var.h>
111 #include <netinet/ip.h>
112 #include <netinet/in_pcb.h>
113 #include <netinet/ip_var.h>
114 #include <netinet/ip_icmp.h>
115 #include <netinet/ip_divert.h>
116 #include <netinet/ip_flow.h>
118 #include <sys/thread2.h>
119 #include <sys/msgport2.h>
120 #include <net/netmsg2.h>
122 #include <sys/socketvar.h>
124 #include <net/ipfw/ip_fw.h>
125 #include <net/dummynet/ip_dummynet.h>
128 #include <netinet6/ipsec.h>
129 #include <netproto/key/key.h>
133 #include <netproto/ipsec/ipsec.h>
134 #include <netproto/ipsec/key.h>
138 static int ip_rsvp_on;
139 struct socket *ip_rsvpd;
141 int ipforwarding = 0;
142 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
143 &ipforwarding, 0, "Enable IP forwarding between interfaces");
145 static int ipsendredirects = 1; /* XXX */
146 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
147 &ipsendredirects, 0, "Enable sending IP redirects");
149 int ip_defttl = IPDEFTTL;
150 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
151 &ip_defttl, 0, "Maximum TTL on IP packets");
153 static int ip_dosourceroute = 0;
154 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
155 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
157 static int ip_acceptsourceroute = 0;
158 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
159 CTLFLAG_RW, &ip_acceptsourceroute, 0,
160 "Enable accepting source routed IP packets");
162 static int ip_keepfaith = 0;
163 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
165 "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
167 static int nipq = 0; /* total # of reass queues */
169 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
171 "Maximum number of IPv4 fragment reassembly queue entries");
173 static int maxfragsperpacket;
174 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
175 &maxfragsperpacket, 0,
176 "Maximum number of IPv4 fragments allowed per packet");
178 static int ip_sendsourcequench = 0;
179 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
180 &ip_sendsourcequench, 0,
181 "Enable the transmission of source quench packets");
183 int ip_do_randomid = 1;
184 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
186 "Assign random ip_id values");
188 * XXX - Setting ip_checkinterface mostly implements the receive side of
189 * the Strong ES model described in RFC 1122, but since the routing table
190 * and transmit implementation do not implement the Strong ES model,
191 * setting this to 1 results in an odd hybrid.
193 * XXX - ip_checkinterface currently must be disabled if you use ipnat
194 * to translate the destination address to another local interface.
196 * XXX - ip_checkinterface must be disabled if you add IP aliases
197 * to the loopback interface instead of the interface where the
198 * packets for those addresses are received.
200 static int ip_checkinterface = 0;
201 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
202 &ip_checkinterface, 0, "Verify packet arrives on correct interface");
204 static u_long ip_hash_count = 0;
205 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, hash_count, CTLFLAG_RD,
206 &ip_hash_count, 0, "Number of packets hashed by IP");
209 static u_long ip_rehash_count = 0;
210 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, rehash_count, CTLFLAG_RD,
211 &ip_rehash_count, 0, "Number of packets rehashed by IP");
213 static u_long ip_dispatch_fast = 0;
214 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_fast_count, CTLFLAG_RD,
215 &ip_dispatch_fast, 0, "Number of packets handled on current CPU");
217 static u_long ip_dispatch_slow = 0;
218 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_slow_count, CTLFLAG_RD,
219 &ip_dispatch_slow, 0, "Number of packets messaged to another CPU");
222 static struct lwkt_token ipq_token = LWKT_TOKEN_INITIALIZER(ipq_token);
225 static int ipprintfs = 0;
228 extern struct domain inetdomain;
229 extern struct protosw inetsw[];
230 u_char ip_protox[IPPROTO_MAX];
231 struct in_ifaddrhead in_ifaddrheads[MAXCPU]; /* first inet address */
232 struct in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU];
233 /* inet addr hash table */
234 u_long in_ifaddrhmask; /* mask for hash table */
236 struct ip_stats ipstats_percpu[MAXCPU];
239 sysctl_ipstats(SYSCTL_HANDLER_ARGS)
243 for (cpu = 0; cpu < ncpus; ++cpu) {
244 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu],
245 sizeof(struct ip_stats))))
247 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu],
248 sizeof(struct ip_stats))))
254 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
255 0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics");
257 SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
258 &ipstat, ip_stats, "IP statistics");
261 /* Packet reassembly stuff */
262 #define IPREASS_NHASH_LOG2 6
263 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
264 #define IPREASS_HMASK (IPREASS_NHASH - 1)
265 #define IPREASS_HASH(x,y) \
266 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
268 static TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH];
271 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
272 &ip_mtu, 0, "Default MTU");
276 static int ipstealth = 0;
277 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, "");
279 static const int ipstealth = 0;
282 struct mbuf *(*ip_divert_p)(struct mbuf *, int, int);
284 struct pfil_head inet_pfil_hook;
287 * struct ip_srcrt_opt is used to store packet state while it travels
290 * XXX Note that the code even makes assumptions on the size and
291 * alignment of fields inside struct ip_srcrt so e.g. adding some
292 * fields will break the code. This needs to be fixed.
294 * We need to save the IP options in case a protocol wants to respond
295 * to an incoming packet over the same route if the packet got here
296 * using IP source routing. This allows connection establishment and
297 * maintenance when the remote end is on a network that is not known
301 struct in_addr dst; /* final destination */
302 char nop; /* one NOP to align */
303 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
304 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
307 struct ip_srcrt_opt {
309 struct ip_srcrt ip_srcrt;
312 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management");
313 static struct malloc_pipe ipq_mpipe;
315 static void save_rte(struct mbuf *, u_char *, struct in_addr);
316 static int ip_dooptions(struct mbuf *m, int, struct sockaddr_in *);
317 static void ip_freef(struct ipqhead *, struct ipq *);
318 static void ip_input_handler(netmsg_t);
321 * IP initialization: fill in IP protocol switch table.
322 * All protocols not implemented in kernel go to raw IP protocol handler.
334 * Make sure we can handle a reasonable number of fragments but
335 * cap it at 4000 (XXX).
337 mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq),
338 IFQ_MAXLEN, 4000, 0, NULL, NULL, NULL);
339 for (i = 0; i < ncpus; ++i) {
340 TAILQ_INIT(&in_ifaddrheads[i]);
341 in_ifaddrhashtbls[i] =
342 hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
344 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
347 for (i = 0; i < IPPROTO_MAX; i++)
348 ip_protox[i] = pr - inetsw;
349 for (pr = inetdomain.dom_protosw;
350 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
351 if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol) {
352 if (pr->pr_protocol != IPPROTO_RAW)
353 ip_protox[pr->pr_protocol] = pr - inetsw;
357 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
358 inet_pfil_hook.ph_af = AF_INET;
359 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) {
360 kprintf("%s: WARNING: unable to register pfil hook, "
361 "error %d\n", __func__, i);
364 for (i = 0; i < IPREASS_NHASH; i++)
367 maxnipq = nmbclusters / 32;
368 maxfragsperpacket = 16;
370 ip_id = time_second & 0xffff;
373 * Initialize IP statistics counters for each CPU.
377 for (cpu = 0; cpu < ncpus; ++cpu) {
378 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats));
381 bzero(&ipstat, sizeof(struct ip_stats));
384 netisr_register(NETISR_IP, ip_input_handler, ip_cpufn_in);
385 netisr_register_hashcheck(NETISR_IP, ip_hashcheck);
388 /* Do transport protocol processing. */
390 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip)
392 const struct protosw *pr = &inetsw[ip_protox[ip->ip_p]];
395 * Switch out to protocol's input routine.
398 pr->pr_input(&m, &hlen, ip->ip_p);
403 transport_processing_handler(netmsg_t msg)
405 struct netmsg_packet *pmsg = &msg->packet;
409 ip = mtod(pmsg->nm_packet, struct ip *);
410 hlen = pmsg->base.lmsg.u.ms_result;
412 transport_processing_oncpu(pmsg->nm_packet, hlen, ip);
413 /* msg was embedded in the mbuf, do not reply! */
417 ip_input_handler(netmsg_t msg)
419 ip_input(msg->packet.nm_packet);
420 /* msg was embedded in the mbuf, do not reply! */
424 * IP input routine. Checksum and byte swap header. If fragmented
425 * try to reassemble. Process options. Pass to next level.
428 ip_input(struct mbuf *m)
431 struct in_ifaddr *ia = NULL;
432 struct in_ifaddr_container *iac;
435 struct in_addr pkt_dst;
436 boolean_t using_srcrt = FALSE; /* forward (by PFIL_HOOKS) */
437 struct in_addr odst; /* original dst address(NAT) */
439 struct sockaddr_in *next_hop = NULL;
442 struct tdb_ident *tdbi;
443 struct secpolicy *sp;
450 * This routine is called from numerous places which may not have
451 * characterized the packet.
453 if ((m->m_flags & M_HASH) == 0) {
454 atomic_add_long(&ip_hash_count, 1);
455 ip_cpufn(&m, 0, IP_MPORT_IN);
458 KKASSERT(m->m_flags & M_HASH);
460 ip = mtod(m, struct ip *);
463 * Pull out certain tags
465 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
467 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
468 KKASSERT(mtag != NULL);
469 next_hop = m_tag_data(mtag);
472 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
473 /* dummynet already filtered us */
474 ip = mtod(m, struct ip *);
475 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
481 /* length checks already done in ip_cpufn() */
482 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf"));
484 if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
485 ipstat.ips_badvers++;
489 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
490 /* length checks already done in ip_cpufn() */
491 KASSERT(hlen >= sizeof(struct ip), ("IP header len too small"));
492 KASSERT(m->m_len >= hlen, ("complete IP header not in one mbuf"));
494 /* 127/8 must not appear on wire - RFC1122 */
495 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
496 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
497 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) {
498 ipstat.ips_badaddr++;
503 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
504 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
506 if (hlen == sizeof(struct ip))
507 sum = in_cksum_hdr(ip);
509 sum = in_cksum(m, hlen);
517 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
518 /* packet is dropped by traffic conditioner */
523 * Convert fields to host representation.
525 ip->ip_len = ntohs(ip->ip_len);
526 ip->ip_off = ntohs(ip->ip_off);
528 /* length checks already done in ip_cpufn() */
529 KASSERT(ip->ip_len >= hlen, ("total length less then header length"));
530 KASSERT(m->m_pkthdr.len >= ip->ip_len, ("mbuf too short"));
533 * Trim mbufs if longer than the IP header would have us expect.
535 if (m->m_pkthdr.len > ip->ip_len) {
536 if (m->m_len == m->m_pkthdr.len) {
537 m->m_len = ip->ip_len;
538 m->m_pkthdr.len = ip->ip_len;
540 m_adj(m, ip->ip_len - m->m_pkthdr.len);
543 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
545 * Bypass packet filtering for packets from a tunnel (gif).
547 if (ipsec_gethist(m, NULL))
553 * Right now when no processing on packet has done
554 * and it is still fresh out of network we do our black
556 * - Firewall: deny/allow/divert
557 * - Xlate: translate packet's addr/port (NAT).
558 * - Pipe: pass pkt through dummynet.
559 * - Wrap: fake packet's addr/port <unimpl.>
560 * - Encapsulate: put it in another IP and send out. <unimp.>
565 * If we've been forwarded from the output side, then
566 * skip the firewall a second time
568 if (next_hop != NULL)
572 if (!pfil_has_hooks(&inet_pfil_hook)) {
573 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
575 * Strip dummynet tags from stranded packets
577 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
578 KKASSERT(mtag != NULL);
579 m_tag_delete(m, mtag);
580 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
586 * Run through list of hooks for input packets.
588 * NOTE! If the packet is rewritten pf/ipfw/whoever must
592 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN))
594 if (m == NULL) /* consumed by filter */
596 ip = mtod(m, struct ip *);
597 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
598 using_srcrt = (odst.s_addr != ip->ip_dst.s_addr);
600 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
601 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
602 KKASSERT(mtag != NULL);
603 next_hop = m_tag_data(mtag);
605 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
609 if (m->m_pkthdr.fw_flags & FW_MBUF_REDISPATCH) {
610 m->m_pkthdr.fw_flags &= ~FW_MBUF_REDISPATCH;
614 * Process options and, if not destined for us,
615 * ship it on. ip_dooptions returns 1 when an
616 * error was detected (causing an icmp message
617 * to be sent and the original packet to be freed).
619 if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, next_hop))
622 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
623 * matter if it is destined to another node, or whether it is
624 * a multicast one, RSVP wants it! and prevents it from being forwarded
625 * anywhere else. Also checks if the rsvp daemon is running before
626 * grabbing the packet.
628 if (rsvp_on && ip->ip_p == IPPROTO_RSVP)
632 * Check our list of addresses, to see if the packet is for us.
633 * If we don't have any addresses, assume any unicast packet
634 * we receive might be for us (and let the upper layers deal
637 if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) &&
638 !(m->m_flags & (M_MCAST | M_BCAST)))
642 * Cache the destination address of the packet; this may be
643 * changed by use of 'ipfw fwd'.
645 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
648 * Enable a consistency check between the destination address
649 * and the arrival interface for a unicast packet (the RFC 1122
650 * strong ES model) if IP forwarding is disabled and the packet
651 * is not locally generated and the packet is not subject to
654 * XXX - Checking also should be disabled if the destination
655 * address is ipnat'ed to a different interface.
657 * XXX - Checking is incompatible with IP aliases added
658 * to the loopback interface instead of the interface where
659 * the packets are received.
661 checkif = ip_checkinterface &&
663 m->m_pkthdr.rcvif != NULL &&
664 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) &&
668 * Check for exact addresses in the hash bucket.
670 LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
674 * If the address matches, verify that the packet
675 * arrived via the correct interface if checking is
678 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
679 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
685 * Check for broadcast addresses.
687 * Only accept broadcast packets that arrive via the matching
688 * interface. Reception of forwarded directed broadcasts would
689 * be handled via ip_forward() and ether_output() with the loopback
690 * into the stack for SIMPLEX interfaces handled by ether_output().
692 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
693 struct ifaddr_container *ifac;
695 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid],
697 struct ifaddr *ifa = ifac->ifa;
699 if (ifa->ifa_addr == NULL) /* shutdown/startup race */
701 if (ifa->ifa_addr->sa_family != AF_INET)
704 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
707 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
710 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
715 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
716 struct in_multi *inm;
718 /* XXX Multicast is not MPSAFE yet */
721 if (ip_mrouter != NULL) {
723 * If we are acting as a multicast router, all
724 * incoming multicast packets are passed to the
725 * kernel-level multicast forwarding function.
726 * The packet is returned (relatively) intact; if
727 * ip_mforward() returns a non-zero value, the packet
728 * must be discarded, else it may be accepted below.
730 if (ip_mforward != NULL &&
731 ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) {
733 ipstat.ips_cantforward++;
739 * The process-level routing daemon needs to receive
740 * all multicast IGMP packets, whether or not this
741 * host belongs to their destination groups.
743 if (ip->ip_p == IPPROTO_IGMP) {
747 ipstat.ips_forward++;
750 * See if we belong to the destination multicast group on the
753 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
756 ipstat.ips_notmember++;
764 if (ip->ip_dst.s_addr == INADDR_BROADCAST)
766 if (ip->ip_dst.s_addr == INADDR_ANY)
770 * FAITH(Firewall Aided Internet Translator)
772 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
774 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
782 * Not for us; forward if possible and desirable.
785 ipstat.ips_cantforward++;
790 * Enforce inbound IPsec SPD.
792 if (ipsec4_in_reject(m, NULL)) {
793 ipsecstat.in_polvio++;
798 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
801 tdbi = (struct tdb_ident *)m_tag_data(mtag);
802 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
804 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
805 IP_FORWARDING, &error);
807 if (sp == NULL) { /* NB: can happen if error */
809 /*XXX error stat???*/
810 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
815 * Check security policy against packet attributes.
817 error = ipsec_in_reject(sp, m);
821 ipstat.ips_cantforward++;
825 ip_forward(m, using_srcrt, next_hop);
832 * IPSTEALTH: Process non-routing options only
833 * if the packet is destined for us.
836 hlen > sizeof(struct ip) &&
837 ip_dooptions(m, 1, next_hop))
840 /* Count the packet in the ip address stats */
842 ia->ia_ifa.if_ipackets++;
843 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
847 * If offset or IP_MF are set, must reassemble.
848 * Otherwise, nothing need be done.
849 * (We could look in the reassembly queue to see
850 * if the packet was previously fragmented,
851 * but it's not worth the time; just let them time out.)
853 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
855 * Attempt reassembly; if it succeeds, proceed. ip_reass()
856 * will return a different mbuf.
858 * NOTE: ip_reass() returns m with M_HASH cleared to force
859 * us to recharacterize the packet.
864 ip = mtod(m, struct ip *);
866 /* Get the header length of the reassembled packet */
867 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
874 * enforce IPsec policy checking if we are seeing last header.
875 * note that we do not visit this with protocols with pcb layer
876 * code - like udp/tcp/raw ip.
878 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) &&
879 ipsec4_in_reject(m, NULL)) {
880 ipsecstat.in_polvio++;
886 * enforce IPsec policy checking if we are seeing last header.
887 * note that we do not visit this with protocols with pcb layer
888 * code - like udp/tcp/raw ip.
890 if (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) {
892 * Check if the packet has already had IPsec processing
893 * done. If so, then just pass it along. This tag gets
894 * set during AH, ESP, etc. input handling, before the
895 * packet is returned to the ip input queue for delivery.
897 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
900 tdbi = (struct tdb_ident *)m_tag_data(mtag);
901 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
903 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
904 IP_FORWARDING, &error);
908 * Check security policy against packet attributes.
910 error = ipsec_in_reject(sp, m);
913 /* XXX error stat??? */
915 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
922 #endif /* FAST_IPSEC */
925 * We must forward the packet to the correct protocol thread if
926 * we are not already in it.
928 * NOTE: ip_len is now in host form. ip_len is not adjusted
929 * further for protocol processing, instead we pass hlen
930 * to the protosw and let it deal with it.
932 ipstat.ips_delivered++;
934 if ((m->m_flags & M_HASH) == 0) {
936 atomic_add_long(&ip_rehash_count, 1);
938 ip->ip_len = htons(ip->ip_len + hlen);
939 ip->ip_off = htons(ip->ip_off);
941 ip_cpufn(&m, 0, IP_MPORT_IN);
945 ip = mtod(m, struct ip *);
946 ip->ip_len = ntohs(ip->ip_len) - hlen;
947 ip->ip_off = ntohs(ip->ip_off);
948 KKASSERT(m->m_flags & M_HASH);
950 port = netisr_portfn(m->m_pkthdr.hash);
952 if (port != &curthread->td_msgport) {
953 struct netmsg_packet *pmsg;
956 atomic_add_long(&ip_dispatch_slow, 1);
959 pmsg = &m->m_hdr.mh_netmsg;
960 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport,
961 0, transport_processing_handler);
963 pmsg->base.lmsg.u.ms_result = hlen;
964 lwkt_sendmsg(port, &pmsg->base.lmsg);
967 atomic_add_long(&ip_dispatch_fast, 1);
969 transport_processing_oncpu(m, hlen, ip);
978 * Take incoming datagram fragment and try to reassemble it into
979 * whole datagram. If a chain for reassembly of this datagram already
980 * exists, then it is given as fp; otherwise have to make a chain.
983 ip_reass(struct mbuf *m)
985 struct ip *ip = mtod(m, struct ip *);
986 struct mbuf *p = NULL, *q, *nq;
988 struct ipq *fp = NULL;
989 struct ipqhead *head;
990 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
994 /* If maxnipq is 0, never accept fragments. */
996 ipstat.ips_fragments++;
997 ipstat.ips_fragdropped++;
1002 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
1004 * Look for queue of fragments of this datagram.
1006 lwkt_gettoken(&ipq_token);
1008 TAILQ_FOREACH(fp, head, ipq_list) {
1009 if (ip->ip_id == fp->ipq_id &&
1010 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
1011 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
1012 ip->ip_p == fp->ipq_p)
1019 * Enforce upper bound on number of fragmented packets
1020 * for which we attempt reassembly;
1021 * If maxnipq is -1, accept all fragments without limitation.
1023 if (nipq > maxnipq && maxnipq > 0) {
1025 * drop something from the tail of the current queue
1026 * before proceeding further
1028 struct ipq *q = TAILQ_LAST(head, ipqhead);
1031 * The current queue is empty,
1032 * so drop from one of the others.
1034 for (i = 0; i < IPREASS_NHASH; i++) {
1035 struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead);
1037 ipstat.ips_fragtimeout += r->ipq_nfrags;
1038 ip_freef(&ipq[i], r);
1043 ipstat.ips_fragtimeout += q->ipq_nfrags;
1049 * Adjust ip_len to not reflect header,
1050 * convert offset of this to bytes.
1053 if (ip->ip_off & IP_MF) {
1055 * Make sure that fragments have a data length
1056 * that's a non-zero multiple of 8 bytes.
1058 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1059 ipstat.ips_toosmall++; /* XXX */
1063 m->m_flags |= M_FRAG;
1065 m->m_flags &= ~M_FRAG;
1069 ipstat.ips_fragments++;
1070 m->m_pkthdr.header = ip;
1073 * If the hardware has not done csum over this fragment
1074 * then csum_data is not valid at all.
1076 if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID))
1077 == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) {
1078 m->m_pkthdr.csum_data = 0;
1079 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
1083 * Presence of header sizes in mbufs
1084 * would confuse code below.
1090 * If first fragment to arrive, create a reassembly queue.
1093 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL)
1095 TAILQ_INSERT_HEAD(head, fp, ipq_list);
1098 fp->ipq_ttl = IPFRAGTTL;
1099 fp->ipq_p = ip->ip_p;
1100 fp->ipq_id = ip->ip_id;
1101 fp->ipq_src = ip->ip_src;
1102 fp->ipq_dst = ip->ip_dst;
1104 m->m_nextpkt = NULL;
1110 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1113 * Find a segment which begins after this one does.
1115 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1116 if (GETIP(q)->ip_off > ip->ip_off)
1121 * If there is a preceding segment, it may provide some of
1122 * our data already. If so, drop the data from the incoming
1123 * segment. If it provides all of our data, drop us, otherwise
1124 * stick new segment in the proper place.
1126 * If some of the data is dropped from the the preceding
1127 * segment, then it's checksum is invalidated.
1130 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1132 if (i >= ip->ip_len)
1135 m->m_pkthdr.csum_flags = 0;
1139 m->m_nextpkt = p->m_nextpkt;
1142 m->m_nextpkt = fp->ipq_frags;
1147 * While we overlap succeeding segments trim them or,
1148 * if they are completely covered, dequeue them.
1150 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1152 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1153 if (i < GETIP(q)->ip_len) {
1154 GETIP(q)->ip_len -= i;
1155 GETIP(q)->ip_off += i;
1157 q->m_pkthdr.csum_flags = 0;
1162 ipstat.ips_fragdropped++;
1164 q->m_nextpkt = NULL;
1170 * Check for complete reassembly and perform frag per packet
1173 * Frag limiting is performed here so that the nth frag has
1174 * a chance to complete the packet before we drop the packet.
1175 * As a result, n+1 frags are actually allowed per packet, but
1176 * only n will ever be stored. (n = maxfragsperpacket.)
1180 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1181 if (GETIP(q)->ip_off != next) {
1182 if (fp->ipq_nfrags > maxfragsperpacket) {
1183 ipstat.ips_fragdropped += fp->ipq_nfrags;
1188 next += GETIP(q)->ip_len;
1190 /* Make sure the last packet didn't have the IP_MF flag */
1191 if (p->m_flags & M_FRAG) {
1192 if (fp->ipq_nfrags > maxfragsperpacket) {
1193 ipstat.ips_fragdropped += fp->ipq_nfrags;
1200 * Reassembly is complete. Make sure the packet is a sane size.
1204 if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
1205 ipstat.ips_toolong++;
1206 ipstat.ips_fragdropped += fp->ipq_nfrags;
1212 * Concatenate fragments.
1219 q->m_nextpkt = NULL;
1220 for (q = nq; q != NULL; q = nq) {
1222 q->m_nextpkt = NULL;
1223 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1224 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1229 * Clean up the 1's complement checksum. Carry over 16 bits must
1230 * be added back. This assumes no more then 65535 packet fragments
1231 * were reassembled. A second carry can also occur (but not a third).
1233 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) +
1234 (m->m_pkthdr.csum_data >> 16);
1235 if (m->m_pkthdr.csum_data > 0xFFFF)
1236 m->m_pkthdr.csum_data -= 0xFFFF;
1239 * Create header for new ip packet by
1240 * modifying header of first packet;
1241 * dequeue and discard fragment reassembly header.
1242 * Make header visible.
1245 ip->ip_src = fp->ipq_src;
1246 ip->ip_dst = fp->ipq_dst;
1247 TAILQ_REMOVE(head, fp, ipq_list);
1249 mpipe_free(&ipq_mpipe, fp);
1250 m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
1251 m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
1252 /* some debugging cruft by sklower, below, will go away soon */
1253 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1256 for (n = m; n; n = n->m_next)
1258 m->m_pkthdr.len = plen;
1262 * Reassembly complete, return the next protocol.
1264 * Be sure to clear M_HASH to force the packet
1265 * to be re-characterized.
1267 * Clear M_FRAG, we are no longer a fragment.
1269 m->m_flags &= ~(M_HASH | M_FRAG);
1271 ipstat.ips_reassembled++;
1272 lwkt_reltoken(&ipq_token);
1276 ipstat.ips_fragdropped++;
1281 lwkt_reltoken(&ipq_token);
1288 * Free a fragment reassembly header and all
1289 * associated datagrams.
1291 * Called with ipq_token held.
1294 ip_freef(struct ipqhead *fhp, struct ipq *fp)
1299 * Remove first to protect against blocking
1301 TAILQ_REMOVE(fhp, fp, ipq_list);
1304 * Clean out at our leisure
1306 while (fp->ipq_frags) {
1308 fp->ipq_frags = q->m_nextpkt;
1309 q->m_nextpkt = NULL;
1312 mpipe_free(&ipq_mpipe, fp);
1317 * IP timer processing;
1318 * if a timer expires on a reassembly
1319 * queue, discard it.
1324 struct ipq *fp, *fp_temp;
1325 struct ipqhead *head;
1328 lwkt_gettoken(&ipq_token);
1329 for (i = 0; i < IPREASS_NHASH; i++) {
1331 TAILQ_FOREACH_MUTABLE(fp, head, ipq_list, fp_temp) {
1332 if (--fp->ipq_ttl == 0) {
1333 ipstat.ips_fragtimeout += fp->ipq_nfrags;
1339 * If we are over the maximum number of fragments
1340 * (due to the limit being lowered), drain off
1341 * enough to get down to the new limit.
1343 if (maxnipq >= 0 && nipq > maxnipq) {
1344 for (i = 0; i < IPREASS_NHASH; i++) {
1346 while (nipq > maxnipq && !TAILQ_EMPTY(head)) {
1347 ipstat.ips_fragdropped +=
1348 TAILQ_FIRST(head)->ipq_nfrags;
1349 ip_freef(head, TAILQ_FIRST(head));
1353 lwkt_reltoken(&ipq_token);
1358 * Drain off all datagram fragments.
1363 struct ipqhead *head;
1366 lwkt_gettoken(&ipq_token);
1367 for (i = 0; i < IPREASS_NHASH; i++) {
1369 while (!TAILQ_EMPTY(head)) {
1370 ipstat.ips_fragdropped += TAILQ_FIRST(head)->ipq_nfrags;
1371 ip_freef(head, TAILQ_FIRST(head));
1374 lwkt_reltoken(&ipq_token);
1379 * Do option processing on a datagram,
1380 * possibly discarding it if bad options are encountered,
1381 * or forwarding it if source-routed.
1382 * The pass argument is used when operating in the IPSTEALTH
1383 * mode to tell what options to process:
1384 * [LS]SRR (pass 0) or the others (pass 1).
1385 * The reason for as many as two passes is that when doing IPSTEALTH,
1386 * non-routing options should be processed only if the packet is for us.
1387 * Returns 1 if packet has been forwarded/freed,
1388 * 0 if the packet should be processed further.
1391 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
1393 struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET };
1394 struct ip *ip = mtod(m, struct ip *);
1396 struct in_ifaddr *ia;
1397 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB;
1398 boolean_t forward = FALSE;
1399 struct in_addr *sin, dst;
1403 cp = (u_char *)(ip + 1);
1404 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1405 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1406 opt = cp[IPOPT_OPTVAL];
1407 if (opt == IPOPT_EOL)
1409 if (opt == IPOPT_NOP)
1412 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1413 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1416 optlen = cp[IPOPT_OLEN];
1417 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1418 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1428 * Source routing with record.
1429 * Find interface with current destination address.
1430 * If none on this machine then drop if strictly routed,
1431 * or do nothing if loosely routed.
1432 * Record interface address and bring up next address
1433 * component. If strictly routed make sure next
1434 * address is on directly accessible net.
1438 if (ipstealth && pass > 0)
1440 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1441 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1444 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1445 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1448 ipaddr.sin_addr = ip->ip_dst;
1449 ia = (struct in_ifaddr *)
1450 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1452 if (opt == IPOPT_SSRR) {
1453 type = ICMP_UNREACH;
1454 code = ICMP_UNREACH_SRCFAIL;
1457 if (!ip_dosourceroute)
1458 goto nosourcerouting;
1460 * Loose routing, and not at next destination
1461 * yet; nothing to do except forward.
1465 off--; /* 0 origin */
1466 if (off > optlen - (int)sizeof(struct in_addr)) {
1468 * End of source route. Should be for us.
1470 if (!ip_acceptsourceroute)
1471 goto nosourcerouting;
1472 save_rte(m, cp, ip->ip_src);
1477 if (!ip_dosourceroute) {
1479 char buf[sizeof "aaa.bbb.ccc.ddd"];
1482 * Acting as a router, so generate ICMP
1485 strcpy(buf, inet_ntoa(ip->ip_dst));
1487 "attempted source route from %s to %s\n",
1488 inet_ntoa(ip->ip_src), buf);
1489 type = ICMP_UNREACH;
1490 code = ICMP_UNREACH_SRCFAIL;
1494 * Not acting as a router,
1498 ipstat.ips_cantforward++;
1505 * locate outgoing interface
1507 memcpy(&ipaddr.sin_addr, cp + off,
1508 sizeof ipaddr.sin_addr);
1510 if (opt == IPOPT_SSRR) {
1511 #define INA struct in_ifaddr *
1512 #define SA struct sockaddr *
1513 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr))
1515 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1517 ia = ip_rtaddr(ipaddr.sin_addr, NULL);
1520 type = ICMP_UNREACH;
1521 code = ICMP_UNREACH_SRCFAIL;
1524 ip->ip_dst = ipaddr.sin_addr;
1525 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1526 sizeof(struct in_addr));
1527 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1529 * Let ip_intr's mcast routing check handle mcast pkts
1531 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1535 if (ipstealth && pass == 0)
1537 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1538 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1541 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1542 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1546 * If no space remains, ignore.
1548 off--; /* 0 origin */
1549 if (off > optlen - (int)sizeof(struct in_addr))
1551 memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1552 sizeof ipaddr.sin_addr);
1554 * locate outgoing interface; if we're the destination,
1555 * use the incoming interface (should be same).
1557 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL &&
1558 (ia = ip_rtaddr(ipaddr.sin_addr, NULL)) == NULL) {
1559 type = ICMP_UNREACH;
1560 code = ICMP_UNREACH_HOST;
1563 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1564 sizeof(struct in_addr));
1565 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1569 if (ipstealth && pass == 0)
1571 code = cp - (u_char *)ip;
1572 if (optlen < 4 || optlen > 40) {
1573 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1576 if ((off = cp[IPOPT_OFFSET]) < 5) {
1577 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1580 if (off > optlen - (int)sizeof(int32_t)) {
1581 cp[IPOPT_OFFSET + 1] += (1 << 4);
1582 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1583 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1588 off--; /* 0 origin */
1589 sin = (struct in_addr *)(cp + off);
1590 switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1592 case IPOPT_TS_TSONLY:
1595 case IPOPT_TS_TSANDADDR:
1596 if (off + sizeof(n_time) +
1597 sizeof(struct in_addr) > optlen) {
1598 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1601 ipaddr.sin_addr = dst;
1602 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1606 memcpy(sin, &IA_SIN(ia)->sin_addr,
1607 sizeof(struct in_addr));
1608 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1609 off += sizeof(struct in_addr);
1612 case IPOPT_TS_PRESPEC:
1613 if (off + sizeof(n_time) +
1614 sizeof(struct in_addr) > optlen) {
1615 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1618 memcpy(&ipaddr.sin_addr, sin,
1619 sizeof(struct in_addr));
1620 if (ifa_ifwithaddr((SA)&ipaddr) == NULL)
1622 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1623 off += sizeof(struct in_addr);
1627 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1631 memcpy(cp + off, &ntime, sizeof(n_time));
1632 cp[IPOPT_OFFSET] += sizeof(n_time);
1635 if (forward && ipforwarding) {
1636 ip_forward(m, TRUE, next_hop);
1641 icmp_error(m, type, code, 0, 0);
1642 ipstat.ips_badoptions++;
1647 * Given address of next destination (final or next hop),
1648 * return internet address info of interface to be used to get there.
1651 ip_rtaddr(struct in_addr dst, struct route *ro0)
1653 struct route sro, *ro;
1654 struct sockaddr_in *sin;
1655 struct in_ifaddr *ia;
1660 bzero(&sro, sizeof(sro));
1664 sin = (struct sockaddr_in *)&ro->ro_dst;
1666 if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) {
1667 if (ro->ro_rt != NULL) {
1671 sin->sin_family = AF_INET;
1672 sin->sin_len = sizeof *sin;
1673 sin->sin_addr = dst;
1674 rtalloc_ign(ro, RTF_PRCLONING);
1677 if (ro->ro_rt == NULL)
1680 ia = ifatoia(ro->ro_rt->rt_ifa);
1688 * Save incoming source route for use in replies,
1689 * to be picked up later by ip_srcroute if the receiver is interested.
1692 save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1695 struct ip_srcrt_opt *opt;
1698 mtag = m_tag_get(PACKET_TAG_IPSRCRT, sizeof(*opt), MB_DONTWAIT);
1701 opt = m_tag_data(mtag);
1703 olen = option[IPOPT_OLEN];
1706 kprintf("save_rte: olen %d\n", olen);
1708 if (olen > sizeof(opt->ip_srcrt) - (1 + sizeof(dst))) {
1712 bcopy(option, opt->ip_srcrt.srcopt, olen);
1713 opt->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1714 opt->ip_srcrt.dst = dst;
1715 m_tag_prepend(m, mtag);
1719 * Retrieve incoming source route for use in replies,
1720 * in the same form used by setsockopt.
1721 * The first hop is placed before the options, will be removed later.
1724 ip_srcroute(struct mbuf *m0)
1726 struct in_addr *p, *q;
1729 struct ip_srcrt_opt *opt;
1734 mtag = m_tag_find(m0, PACKET_TAG_IPSRCRT, NULL);
1737 opt = m_tag_data(mtag);
1739 if (opt->ip_nhops == 0)
1741 m = m_get(MB_DONTWAIT, MT_HEADER);
1745 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt))
1747 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1748 m->m_len = opt->ip_nhops * sizeof(struct in_addr) +
1749 sizeof(struct in_addr) + OPTSIZ;
1752 kprintf("ip_srcroute: nhops %d mlen %d",
1753 opt->ip_nhops, m->m_len);
1758 * First save first hop for return route
1760 p = &opt->ip_srcrt.route[opt->ip_nhops - 1];
1761 *(mtod(m, struct in_addr *)) = *p--;
1764 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1768 * Copy option fields and padding (nop) to mbuf.
1770 opt->ip_srcrt.nop = IPOPT_NOP;
1771 opt->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1772 memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &opt->ip_srcrt.nop,
1774 q = (struct in_addr *)(mtod(m, caddr_t) +
1775 sizeof(struct in_addr) + OPTSIZ);
1778 * Record return path as an IP source route,
1779 * reversing the path (pointers are now aligned).
1781 while (p >= opt->ip_srcrt.route) {
1784 kprintf(" %x", ntohl(q->s_addr));
1789 * Last hop goes to final destination.
1791 *q = opt->ip_srcrt.dst;
1792 m_tag_delete(m0, mtag);
1795 kprintf(" %x\n", ntohl(q->s_addr));
1801 * Strip out IP options.
1804 ip_stripoptions(struct mbuf *m)
1807 struct ip *ip = mtod(m, struct ip *);
1811 optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1812 opts = (caddr_t)(ip + 1);
1813 datalen = m->m_len - (sizeof(struct ip) + optlen);
1814 bcopy(opts + optlen, opts, datalen);
1816 if (m->m_flags & M_PKTHDR)
1817 m->m_pkthdr.len -= optlen;
1818 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1821 u_char inetctlerrmap[PRC_NCMDS] = {
1823 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1824 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1825 EMSGSIZE, EHOSTUNREACH, 0, 0,
1827 ENOPROTOOPT, ECONNREFUSED
1831 * Forward a packet. If some error occurs return the sender
1832 * an icmp packet. Note we can't always generate a meaningful
1833 * icmp message because icmp doesn't have a large enough repertoire
1834 * of codes and types.
1836 * If not forwarding, just drop the packet. This could be confusing
1837 * if ipforwarding was zero but some routing protocol was advancing
1838 * us as a gateway to somewhere. However, we must let the routing
1839 * protocol deal with that.
1841 * The using_srcrt parameter indicates whether the packet is being forwarded
1842 * via a source route.
1845 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop)
1847 struct ip *ip = mtod(m, struct ip *);
1849 struct route fwd_ro;
1850 int error, type = 0, code = 0, destmtu = 0;
1853 struct in_addr pkt_dst;
1857 * Cache the destination address of the packet; this may be
1858 * changed by use of 'ipfw fwd'.
1860 pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst;
1864 kprintf("forward: src %x dst %x ttl %x\n",
1865 ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl);
1868 if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) {
1869 ipstat.ips_cantforward++;
1873 if (!ipstealth && ip->ip_ttl <= IPTTLDEC) {
1874 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1878 bzero(&fwd_ro, sizeof(fwd_ro));
1879 ip_rtaddr(pkt_dst, &fwd_ro);
1880 if (fwd_ro.ro_rt == NULL) {
1881 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1887 * Save the IP header and at most 8 bytes of the payload,
1888 * in case we need to generate an ICMP message to the src.
1890 * XXX this can be optimized a lot by saving the data in a local
1891 * buffer on the stack (72 bytes at most), and only allocating the
1892 * mbuf if really necessary. The vast majority of the packets
1893 * are forwarded without having to send an ICMP back (either
1894 * because unnecessary, or because rate limited), so we are
1895 * really we are wasting a lot of work here.
1897 * We don't use m_copy() because it might return a reference
1898 * to a shared cluster. Both this function and ip_output()
1899 * assume exclusive access to the IP header in `m', so any
1900 * data in a cluster may change before we reach icmp_error().
1902 MGETHDR(mcopy, MB_DONTWAIT, m->m_type);
1903 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, MB_DONTWAIT)) {
1905 * It's probably ok if the pkthdr dup fails (because
1906 * the deep copy of the tag chain failed), but for now
1907 * be conservative and just discard the copy since
1908 * code below may some day want the tags.
1913 if (mcopy != NULL) {
1914 mcopy->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8,
1916 mcopy->m_pkthdr.len = mcopy->m_len;
1917 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1921 ip->ip_ttl -= IPTTLDEC;
1924 * If forwarding packet using same interface that it came in on,
1925 * perhaps should send a redirect to sender to shortcut a hop.
1926 * Only send redirect if source is sending directly to us,
1927 * and if packet was not source routed (or has any options).
1928 * Also, don't send redirect if forwarding using a default route
1929 * or a route modified by a redirect.
1931 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1932 !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) &&
1933 satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY &&
1934 ipsendredirects && !using_srcrt && next_hop == NULL) {
1935 u_long src = ntohl(ip->ip_src.s_addr);
1936 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa;
1938 if (rt_ifa != NULL &&
1939 (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) {
1940 if (rt->rt_flags & RTF_GATEWAY)
1941 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1943 dest = pkt_dst.s_addr;
1945 * Router requirements says to only send
1948 type = ICMP_REDIRECT;
1949 code = ICMP_REDIRECT_HOST;
1952 kprintf("redirect (%d) to %x\n", code, dest);
1957 error = ip_output(m, NULL, &fwd_ro, IP_FORWARDING, NULL, NULL);
1959 ipstat.ips_forward++;
1962 ipflow_create(&fwd_ro, mcopy);
1967 ipstat.ips_redirectsent++;
1970 ipstat.ips_cantforward++;
1977 * Send ICMP message.
1982 case 0: /* forwarded, but need redirect */
1983 /* type, code set above */
1986 case ENETUNREACH: /* shouldn't happen, checked above */
1991 type = ICMP_UNREACH;
1992 code = ICMP_UNREACH_HOST;
1996 type = ICMP_UNREACH;
1997 code = ICMP_UNREACH_NEEDFRAG;
2000 * If the packet is routed over IPsec tunnel, tell the
2001 * originator the tunnel MTU.
2002 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2005 if (fwd_ro.ro_rt != NULL) {
2006 struct secpolicy *sp = NULL;
2011 sp = ipsec4_getpolicybyaddr(mcopy,
2017 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2019 /* count IPsec header size */
2020 ipsechdr = ipsec4_hdrsiz(mcopy,
2025 * find the correct route for outer IPv4
2026 * header, compute tunnel MTU.
2029 if (sp->req != NULL && sp->req->sav != NULL &&
2030 sp->req->sav->sah != NULL) {
2031 ro = &sp->req->sav->sah->sa_route;
2032 if (ro->ro_rt != NULL &&
2033 ro->ro_rt->rt_ifp != NULL) {
2035 ro->ro_rt->rt_ifp->if_mtu;
2036 destmtu -= ipsechdr;
2045 * If the packet is routed over IPsec tunnel, tell the
2046 * originator the tunnel MTU.
2047 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2050 if (fwd_ro.ro_rt != NULL) {
2051 struct secpolicy *sp = NULL;
2056 sp = ipsec_getpolicybyaddr(mcopy,
2062 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2064 /* count IPsec header size */
2065 ipsechdr = ipsec4_hdrsiz(mcopy,
2070 * find the correct route for outer IPv4
2071 * header, compute tunnel MTU.
2074 if (sp->req != NULL &&
2075 sp->req->sav != NULL &&
2076 sp->req->sav->sah != NULL) {
2077 ro = &sp->req->sav->sah->sa_route;
2078 if (ro->ro_rt != NULL &&
2079 ro->ro_rt->rt_ifp != NULL) {
2081 ro->ro_rt->rt_ifp->if_mtu;
2082 destmtu -= ipsechdr;
2089 #else /* !IPSEC && !FAST_IPSEC */
2090 if (fwd_ro.ro_rt != NULL)
2091 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2093 ipstat.ips_cantfrag++;
2098 * A router should not generate ICMP_SOURCEQUENCH as
2099 * required in RFC1812 Requirements for IP Version 4 Routers.
2100 * Source quench could be a big problem under DoS attacks,
2101 * or if the underlying interface is rate-limited.
2102 * Those who need source quench packets may re-enable them
2103 * via the net.inet.ip.sendsourcequench sysctl.
2105 if (!ip_sendsourcequench) {
2109 type = ICMP_SOURCEQUENCH;
2114 case EACCES: /* ipfw denied packet */
2118 icmp_error(mcopy, type, code, dest, destmtu);
2120 if (fwd_ro.ro_rt != NULL)
2121 RTFREE(fwd_ro.ro_rt);
2125 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
2128 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
2132 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
2133 SCM_TIMESTAMP, SOL_SOCKET);
2135 mp = &(*mp)->m_next;
2137 if (inp->inp_flags & INP_RECVDSTADDR) {
2138 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
2139 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2141 mp = &(*mp)->m_next;
2143 if (inp->inp_flags & INP_RECVTTL) {
2144 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
2145 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
2147 mp = &(*mp)->m_next;
2151 * Moving these out of udp_input() made them even more broken
2152 * than they already were.
2154 /* options were tossed already */
2155 if (inp->inp_flags & INP_RECVOPTS) {
2156 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
2157 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
2159 mp = &(*mp)->m_next;
2161 /* ip_srcroute doesn't do what we want here, need to fix */
2162 if (inp->inp_flags & INP_RECVRETOPTS) {
2163 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
2164 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
2166 mp = &(*mp)->m_next;
2169 if (inp->inp_flags & INP_RECVIF) {
2172 struct sockaddr_dl sdl;
2175 struct sockaddr_dl *sdp;
2176 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
2178 if (((ifp = m->m_pkthdr.rcvif)) &&
2179 ((ifp->if_index != 0) && (ifp->if_index <= if_index))) {
2180 sdp = IF_LLSOCKADDR(ifp);
2182 * Change our mind and don't try copy.
2184 if ((sdp->sdl_family != AF_LINK) ||
2185 (sdp->sdl_len > sizeof(sdlbuf))) {
2188 bcopy(sdp, sdl2, sdp->sdl_len);
2192 offsetof(struct sockaddr_dl, sdl_data[0]);
2193 sdl2->sdl_family = AF_LINK;
2194 sdl2->sdl_index = 0;
2195 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2197 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2198 IP_RECVIF, IPPROTO_IP);
2200 mp = &(*mp)->m_next;
2205 * XXX these routines are called from the upper part of the kernel.
2207 * They could also be moved to ip_mroute.c, since all the RSVP
2208 * handling is done there already.
2211 ip_rsvp_init(struct socket *so)
2213 if (so->so_type != SOCK_RAW ||
2214 so->so_proto->pr_protocol != IPPROTO_RSVP)
2217 if (ip_rsvpd != NULL)
2222 * This may seem silly, but we need to be sure we don't over-increment
2223 * the RSVP counter, in case something slips up.
2238 * This may seem silly, but we need to be sure we don't over-decrement
2239 * the RSVP counter, in case something slips up.
2249 rsvp_input(struct mbuf **mp, int *offp, int proto)
2251 struct mbuf *m = *mp;
2255 if (rsvp_input_p) { /* call the real one if loaded */
2257 rsvp_input_p(mp, offp, proto);
2258 return(IPPROTO_DONE);
2261 /* Can still get packets with rsvp_on = 0 if there is a local member
2262 * of the group to which the RSVP packet is addressed. But in this
2263 * case we want to throw the packet away.
2268 return(IPPROTO_DONE);
2271 if (ip_rsvpd != NULL) {
2273 rip_input(mp, offp, proto);
2274 return(IPPROTO_DONE);
2276 /* Drop the packet */
2278 return(IPPROTO_DONE);