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
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of The DragonFly Project nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * Copyright (c) 1982, 1986, 1988, 1993
36 * The Regents of the University of California. All rights reserved.
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in the
45 * documentation and/or other materials provided with the distribution.
46 * 3. All advertising materials mentioning features or use of this software
47 * must display the following acknowledgement:
48 * This product includes software developed by the University of
49 * California, Berkeley and its contributors.
50 * 4. Neither the name of the University nor the names of its contributors
51 * may be used to endorse or promote products derived from this software
52 * without specific prior written permission.
54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 $
68 * $DragonFly: src/sys/netinet/ip_input.c,v 1.81 2008/06/09 11:24:24 sephe Exp $
73 #include "opt_bootp.h"
76 #include "opt_ipdivert.h"
77 #include "opt_ipfilter.h"
78 #include "opt_ipstealth.h"
79 #include "opt_ipsec.h"
81 #include <sys/param.h>
82 #include <sys/systm.h>
84 #include <sys/malloc.h>
85 #include <sys/mpipe.h>
86 #include <sys/domain.h>
87 #include <sys/protosw.h>
88 #include <sys/socket.h>
90 #include <sys/globaldata.h>
91 #include <sys/thread.h>
92 #include <sys/kernel.h>
93 #include <sys/syslog.h>
94 #include <sys/sysctl.h>
95 #include <sys/in_cksum.h>
97 #include <machine/stdarg.h>
100 #include <net/if_types.h>
101 #include <net/if_var.h>
102 #include <net/if_dl.h>
103 #include <net/pfil.h>
104 #include <net/route.h>
105 #include <net/netisr.h>
107 #include <netinet/in.h>
108 #include <netinet/in_systm.h>
109 #include <netinet/in_var.h>
110 #include <netinet/ip.h>
111 #include <netinet/in_pcb.h>
112 #include <netinet/ip_var.h>
113 #include <netinet/ip_icmp.h>
115 #include <sys/thread2.h>
116 #include <sys/msgport2.h>
117 #include <net/netmsg2.h>
119 #include <sys/socketvar.h>
121 #include <net/ipfw/ip_fw.h>
122 #include <net/dummynet/ip_dummynet.h>
125 #include <netinet6/ipsec.h>
126 #include <netproto/key/key.h>
130 #include <netproto/ipsec/ipsec.h>
131 #include <netproto/ipsec/key.h>
135 static int ip_rsvp_on;
136 struct socket *ip_rsvpd;
138 int ipforwarding = 0;
139 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
140 &ipforwarding, 0, "Enable IP forwarding between interfaces");
142 static int ipsendredirects = 1; /* XXX */
143 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
144 &ipsendredirects, 0, "Enable sending IP redirects");
146 int ip_defttl = IPDEFTTL;
147 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
148 &ip_defttl, 0, "Maximum TTL on IP packets");
150 static int ip_dosourceroute = 0;
151 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
152 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
154 static int ip_acceptsourceroute = 0;
155 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
156 CTLFLAG_RW, &ip_acceptsourceroute, 0,
157 "Enable accepting source routed IP packets");
159 static int ip_keepfaith = 0;
160 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
162 "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
164 static int nipq = 0; /* total # of reass queues */
166 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
168 "Maximum number of IPv4 fragment reassembly queue entries");
170 static int maxfragsperpacket;
171 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
172 &maxfragsperpacket, 0,
173 "Maximum number of IPv4 fragments allowed per packet");
175 static int ip_sendsourcequench = 0;
176 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
177 &ip_sendsourcequench, 0,
178 "Enable the transmission of source quench packets");
180 int ip_do_randomid = 1;
181 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
183 "Assign random ip_id values");
185 * XXX - Setting ip_checkinterface mostly implements the receive side of
186 * the Strong ES model described in RFC 1122, but since the routing table
187 * and transmit implementation do not implement the Strong ES model,
188 * setting this to 1 results in an odd hybrid.
190 * XXX - ip_checkinterface currently must be disabled if you use ipnat
191 * to translate the destination address to another local interface.
193 * XXX - ip_checkinterface must be disabled if you add IP aliases
194 * to the loopback interface instead of the interface where the
195 * packets for those addresses are received.
197 static int ip_checkinterface = 0;
198 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
199 &ip_checkinterface, 0, "Verify packet arrives on correct interface");
202 static int ipprintfs = 0;
205 extern struct domain inetdomain;
206 extern struct protosw inetsw[];
207 u_char ip_protox[IPPROTO_MAX];
208 struct in_ifaddrhead in_ifaddrheads[MAXCPU]; /* first inet address */
209 struct in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU];
210 /* inet addr hash table */
211 u_long in_ifaddrhmask; /* mask for hash table */
213 struct ip_stats ipstats_percpu[MAXCPU];
216 sysctl_ipstats(SYSCTL_HANDLER_ARGS)
220 for (cpu = 0; cpu < ncpus; ++cpu) {
221 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu],
222 sizeof(struct ip_stats))))
224 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu],
225 sizeof(struct ip_stats))))
231 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
232 0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics");
234 SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
235 &ipstat, ip_stats, "IP statistics");
238 /* Packet reassembly stuff */
239 #define IPREASS_NHASH_LOG2 6
240 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
241 #define IPREASS_HMASK (IPREASS_NHASH - 1)
242 #define IPREASS_HASH(x,y) \
243 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
245 static struct ipq ipq[IPREASS_NHASH];
248 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
249 &ip_mtu, 0, "Default MTU");
253 static int ipstealth = 0;
254 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, "");
256 static const int ipstealth = 0;
261 ip_fw_chk_t *ip_fw_chk_ptr;
262 ip_fw_dn_io_t *ip_fw_dn_io_ptr;
266 struct pfil_head inet_pfil_hook;
269 * XXX this is ugly -- the following two global variables are
270 * used to store packet state while it travels through the stack.
271 * Note that the code even makes assumptions on the size and
272 * alignment of fields inside struct ip_srcrt so e.g. adding some
273 * fields will break the code. This needs to be fixed.
275 * We need to save the IP options in case a protocol wants to respond
276 * to an incoming packet over the same route if the packet got here
277 * using IP source routing. This allows connection establishment and
278 * maintenance when the remote end is on a network that is not known
281 static int ip_nhops = 0;
283 static struct ip_srcrt {
284 struct in_addr dst; /* final destination */
285 char nop; /* one NOP to align */
286 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
287 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
290 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management");
291 static struct malloc_pipe ipq_mpipe;
293 static void save_rte (u_char *, struct in_addr);
294 static int ip_dooptions (struct mbuf *m, int,
295 struct sockaddr_in *next_hop);
296 static void ip_forward (struct mbuf *m, boolean_t using_srcrt,
297 struct sockaddr_in *next_hop);
298 static void ip_freef (struct ipq *);
299 static void ip_input_handler (struct netmsg *);
300 static struct mbuf *ip_reass (struct mbuf *, struct ipq *,
301 struct ipq *, u_int32_t *);
304 * IP initialization: fill in IP protocol switch table.
305 * All protocols not implemented in kernel go to raw IP protocol handler.
317 * Make sure we can handle a reasonable number of fragments but
318 * cap it at 4000 (XXX).
320 mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq),
321 IFQ_MAXLEN, 4000, 0, NULL);
322 for (i = 0; i < ncpus; ++i) {
323 TAILQ_INIT(&in_ifaddrheads[i]);
324 in_ifaddrhashtbls[i] =
325 hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
327 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
330 for (i = 0; i < IPPROTO_MAX; i++)
331 ip_protox[i] = pr - inetsw;
332 for (pr = inetdomain.dom_protosw;
333 pr < inetdomain.dom_protoswNPROTOSW; pr++)
334 if (pr->pr_domain->dom_family == PF_INET &&
335 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
336 ip_protox[pr->pr_protocol] = pr - inetsw;
338 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
339 inet_pfil_hook.ph_af = AF_INET;
340 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) {
341 kprintf("%s: WARNING: unable to register pfil hook, "
342 "error %d\n", __func__, i);
345 for (i = 0; i < IPREASS_NHASH; i++)
346 ipq[i].next = ipq[i].prev = &ipq[i];
348 maxnipq = nmbclusters / 32;
349 maxfragsperpacket = 16;
351 ip_id = time_second & 0xffff;
354 * Initialize IP statistics counters for each CPU.
358 for (cpu = 0; cpu < ncpus; ++cpu) {
359 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats));
362 bzero(&ipstat, sizeof(struct ip_stats));
365 netisr_register(NETISR_IP, ip_mport_in, ip_input_handler);
369 * XXX watch out this one. It is perhaps used as a cache for
370 * the most recently used route ? it is cleared in in_addroute()
371 * when a new route is successfully created.
373 struct route ipforward_rt[MAXCPU];
375 /* Do transport protocol processing. */
377 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip,
378 struct sockaddr_in *nexthop)
381 * Switch out to protocol's input routine.
383 if (nexthop && ip->ip_p == IPPROTO_TCP) {
384 /* TCP needs IPFORWARD info if available */
387 tag.mh_type = MT_TAG;
388 tag.mh_flags = PACKET_TAG_IPFORWARD;
389 tag.mh_data = (caddr_t)nexthop;
392 (*inetsw[ip_protox[ip->ip_p]].pr_input)
393 ((struct mbuf *)&tag, hlen, ip->ip_p);
395 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen, ip->ip_p);
399 struct netmsg_transport_packet {
400 struct netmsg nm_netmsg;
401 struct mbuf *nm_mbuf;
403 boolean_t nm_hasnexthop;
404 struct sockaddr_in nm_nexthop;
408 transport_processing_handler(netmsg_t netmsg)
410 struct netmsg_transport_packet *msg = (void *)netmsg;
411 struct sockaddr_in *nexthop;
414 ip = mtod(msg->nm_mbuf, struct ip *);
415 nexthop = msg->nm_hasnexthop ? &msg->nm_nexthop : NULL;
416 transport_processing_oncpu(msg->nm_mbuf, msg->nm_hlen, ip, nexthop);
417 lwkt_replymsg(&msg->nm_netmsg.nm_lmsg, 0);
421 ip_input_handler(struct netmsg *msg0)
423 struct mbuf *m = ((struct netmsg_packet *)msg0)->nm_packet;
426 /* msg0 was embedded in the mbuf, do not reply! */
430 * IP input routine. Checksum and byte swap header. If fragmented
431 * try to reassemble. Process options. Pass to next level.
434 ip_input(struct mbuf *m)
438 struct in_ifaddr *ia = NULL;
439 struct in_ifaddr_container *iac;
440 int i, hlen, checkif;
442 struct in_addr pkt_dst;
443 u_int32_t divert_info = 0; /* packet divert/tee info */
444 struct ip_fw_args args;
445 boolean_t using_srcrt = FALSE; /* forward (by PFIL_HOOKS) */
446 boolean_t needredispatch = FALSE;
447 struct in_addr odst; /* original dst address(NAT) */
450 struct tdb_ident *tdbi;
451 struct secpolicy *sp;
458 args.next_hop = NULL;
460 /* Grab info from MT_TAG mbufs prepended to the chain. */
461 while (m != NULL && m->m_type == MT_TAG) {
462 switch(m->_m_tag_id) {
463 case PACKET_TAG_IPFORWARD:
464 args.next_hop = (struct sockaddr_in *)m->m_hdr.mh_data;
467 kprintf("ip_input: unrecognised MT_TAG tag %d\n",
475 /* Extract info from dummynet tag */
476 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
478 args.rule = ((struct dn_pkt *)m_tag_data(mtag))->dn_priv;
480 m_tag_delete(m, mtag);
484 if (args.rule != NULL) { /* dummynet already filtered us */
485 ip = mtod(m, struct ip *);
486 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
492 /* length checks already done in ip_demux() */
493 KASSERT(m->m_len >= sizeof(ip), ("IP header not in one mbuf"));
495 ip = mtod(m, struct ip *);
497 if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
498 ipstat.ips_badvers++;
502 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
503 /* length checks already done in ip_demux() */
504 KASSERT(hlen >= sizeof(struct ip), ("IP header len too small"));
505 KASSERT(m->m_len >= hlen, ("packet shorter than IP header length"));
507 /* 127/8 must not appear on wire - RFC1122 */
508 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
509 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
510 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) {
511 ipstat.ips_badaddr++;
516 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
517 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
519 if (hlen == sizeof(struct ip)) {
520 sum = in_cksum_hdr(ip);
522 sum = in_cksum(m, hlen);
531 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
532 /* packet is dropped by traffic conditioner */
537 * Convert fields to host representation.
539 ip->ip_len = ntohs(ip->ip_len);
540 if (ip->ip_len < hlen) {
544 ip->ip_off = ntohs(ip->ip_off);
547 * Check that the amount of data in the buffers
548 * is as at least much as the IP header would have us expect.
549 * Trim mbufs if longer than we expect.
550 * Drop packet if shorter than we expect.
552 if (m->m_pkthdr.len < ip->ip_len) {
553 ipstat.ips_tooshort++;
556 if (m->m_pkthdr.len > ip->ip_len) {
557 if (m->m_len == m->m_pkthdr.len) {
558 m->m_len = ip->ip_len;
559 m->m_pkthdr.len = ip->ip_len;
561 m_adj(m, ip->ip_len - m->m_pkthdr.len);
563 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
565 * Bypass packet filtering for packets from a tunnel (gif).
567 if (ipsec_gethist(m, NULL))
573 * Right now when no processing on packet has done
574 * and it is still fresh out of network we do our black
576 * - Firewall: deny/allow/divert
577 * - Xlate: translate packet's addr/port (NAT).
578 * - Pipe: pass pkt through dummynet.
579 * - Wrap: fake packet's addr/port <unimpl.>
580 * - Encapsulate: put it in another IP and send out. <unimp.>
586 * Run through list of hooks for input packets.
588 * NB: Beware of the destination address changing (e.g.
589 * by NAT rewriting). When this happens, tell
590 * ip_forward to do the right thing.
592 if (pfil_has_hooks(&inet_pfil_hook)) {
594 if (pfil_run_hooks(&inet_pfil_hook, &m,
595 m->m_pkthdr.rcvif, PFIL_IN)) {
598 if (m == NULL) /* consumed by filter */
600 ip = mtod(m, struct ip *);
601 using_srcrt = (odst.s_addr != ip->ip_dst.s_addr);
604 if (fw_enable && IPFW_LOADED) {
606 * If we've been forwarded from the output side, then
607 * skip the firewall a second time
609 if (args.next_hop != NULL)
613 i = ip_fw_chk_ptr(&args);
616 if ((i & IP_FW_PORT_DENY_FLAG) || m == NULL) { /* drop */
621 ip = mtod(m, struct ip *); /* just in case m changed */
622 if (i == 0 && args.next_hop == NULL) /* common case */
624 if (i & IP_FW_PORT_DYNT_FLAG) {
625 /* Send packet to the appropriate pipe */
626 ip_fw_dn_io_ptr(m, i&0xffff, DN_TO_IP_IN, &args);
630 if (i != 0 && !(i & IP_FW_PORT_DYNT_FLAG)) {
631 /* Divert or tee packet */
636 if (i == 0 && args.next_hop != NULL)
639 * if we get here, the packet must be dropped
647 * Process options and, if not destined for us,
648 * ship it on. ip_dooptions returns 1 when an
649 * error was detected (causing an icmp message
650 * to be sent and the original packet to be freed).
652 ip_nhops = 0; /* for source routed packets */
653 if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, args.next_hop))
656 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
657 * matter if it is destined to another node, or whether it is
658 * a multicast one, RSVP wants it! and prevents it from being forwarded
659 * anywhere else. Also checks if the rsvp daemon is running before
660 * grabbing the packet.
662 if (rsvp_on && ip->ip_p == IPPROTO_RSVP)
666 * Check our list of addresses, to see if the packet is for us.
667 * If we don't have any addresses, assume any unicast packet
668 * we receive might be for us (and let the upper layers deal
671 if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) &&
672 !(m->m_flags & (M_MCAST | M_BCAST)))
676 * Cache the destination address of the packet; this may be
677 * changed by use of 'ipfw fwd'.
679 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst;
682 * Enable a consistency check between the destination address
683 * and the arrival interface for a unicast packet (the RFC 1122
684 * strong ES model) if IP forwarding is disabled and the packet
685 * is not locally generated and the packet is not subject to
688 * XXX - Checking also should be disabled if the destination
689 * address is ipnat'ed to a different interface.
691 * XXX - Checking is incompatible with IP aliases added
692 * to the loopback interface instead of the interface where
693 * the packets are received.
695 checkif = ip_checkinterface &&
697 m->m_pkthdr.rcvif != NULL &&
698 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) &&
699 (args.next_hop == NULL);
702 * Check for exact addresses in the hash bucket.
704 LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
708 * If the address matches, verify that the packet
709 * arrived via the correct interface if checking is
712 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
713 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
719 * Check for broadcast addresses.
721 * Only accept broadcast packets that arrive via the matching
722 * interface. Reception of forwarded directed broadcasts would
723 * be handled via ip_forward() and ether_output() with the loopback
724 * into the stack for SIMPLEX interfaces handled by ether_output().
726 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
727 struct ifaddr_container *ifac;
729 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid],
731 struct ifaddr *ifa = ifac->ifa;
733 if (ifa->ifa_addr == NULL) /* shutdown/startup race */
735 if (ifa->ifa_addr->sa_family != AF_INET)
738 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
741 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
744 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
749 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
750 struct in_multi *inm;
752 if (ip_mrouter != NULL) {
754 * If we are acting as a multicast router, all
755 * incoming multicast packets are passed to the
756 * kernel-level multicast forwarding function.
757 * The packet is returned (relatively) intact; if
758 * ip_mforward() returns a non-zero value, the packet
759 * must be discarded, else it may be accepted below.
761 if (ip_mforward != NULL &&
762 ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) {
763 ipstat.ips_cantforward++;
769 * The process-level routing daemon needs to receive
770 * all multicast IGMP packets, whether or not this
771 * host belongs to their destination groups.
773 if (ip->ip_p == IPPROTO_IGMP)
775 ipstat.ips_forward++;
778 * See if we belong to the destination multicast group on the
781 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
783 ipstat.ips_notmember++;
789 if (ip->ip_dst.s_addr == INADDR_BROADCAST)
791 if (ip->ip_dst.s_addr == INADDR_ANY)
795 * FAITH(Firewall Aided Internet Translator)
797 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
799 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
807 * Not for us; forward if possible and desirable.
810 ipstat.ips_cantforward++;
815 * Enforce inbound IPsec SPD.
817 if (ipsec4_in_reject(m, NULL)) {
818 ipsecstat.in_polvio++;
823 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
826 tdbi = (struct tdb_ident *)m_tag_data(mtag);
827 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
829 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
830 IP_FORWARDING, &error);
832 if (sp == NULL) { /* NB: can happen if error */
834 /*XXX error stat???*/
835 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
840 * Check security policy against packet attributes.
842 error = ipsec_in_reject(sp, m);
846 ipstat.ips_cantforward++;
850 ip_forward(m, using_srcrt, args.next_hop);
857 * IPSTEALTH: Process non-routing options only
858 * if the packet is destined for us.
861 hlen > sizeof(struct ip) &&
862 ip_dooptions(m, 1, args.next_hop))
865 /* Count the packet in the ip address stats */
867 ia->ia_ifa.if_ipackets++;
868 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
872 * If offset or IP_MF are set, must reassemble.
873 * Otherwise, nothing need be done.
874 * (We could look in the reassembly queue to see
875 * if the packet was previously fragmented,
876 * but it's not worth the time; just let them time out.)
878 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
880 /* If maxnipq is 0, never accept fragments. */
882 ipstat.ips_fragments++;
883 ipstat.ips_fragdropped++;
887 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
889 * Look for queue of fragments
892 for (fp = ipq[sum].next; fp != &ipq[sum]; fp = fp->next)
893 if (ip->ip_id == fp->ipq_id &&
894 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
895 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
896 ip->ip_p == fp->ipq_p)
902 * Enforce upper bound on number of fragmented packets
903 * for which we attempt reassembly;
904 * If maxnipq is -1, accept all fragments without limitation.
906 if ((nipq > maxnipq) && (maxnipq > 0)) {
908 * drop something from the tail of the current queue
909 * before proceeding further
911 if (ipq[sum].prev == &ipq[sum]) { /* gak */
912 for (i = 0; i < IPREASS_NHASH; i++) {
913 if (ipq[i].prev != &ipq[i]) {
914 ipstat.ips_fragtimeout +=
915 ipq[i].prev->ipq_nfrags;
916 ip_freef(ipq[i].prev);
921 ipstat.ips_fragtimeout +=
922 ipq[sum].prev->ipq_nfrags;
923 ip_freef(ipq[sum].prev);
928 * Adjust ip_len to not reflect header,
929 * convert offset of this to bytes.
932 if (ip->ip_off & IP_MF) {
934 * Make sure that fragments have a data length
935 * that's a non-zero multiple of 8 bytes.
937 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
938 ipstat.ips_toosmall++; /* XXX */
941 m->m_flags |= M_FRAG;
943 m->m_flags &= ~M_FRAG;
947 * Attempt reassembly; if it succeeds, proceed.
948 * ip_reass() will return a different mbuf, and update
949 * the divert info in divert_info.
951 ipstat.ips_fragments++;
952 m->m_pkthdr.header = ip;
953 m = ip_reass(m, fp, &ipq[sum], &divert_info);
956 ipstat.ips_reassembled++;
957 needredispatch = TRUE;
958 ip = mtod(m, struct ip *);
959 /* Get the header length of the reassembled packet */
960 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
962 /* Restore original checksum before diverting packet */
963 if (divert_info != 0) {
965 ip->ip_len = htons(ip->ip_len);
966 ip->ip_off = htons(ip->ip_off);
968 if (hlen == sizeof(struct ip))
969 ip->ip_sum = in_cksum_hdr(ip);
971 ip->ip_sum = in_cksum(m, hlen);
972 ip->ip_off = ntohs(ip->ip_off);
973 ip->ip_len = ntohs(ip->ip_len);
983 * Divert or tee packet to the divert protocol if required.
985 if (divert_info != 0) {
986 struct mbuf *clone = NULL;
988 /* Clone packet if we're doing a 'tee' */
989 if ((divert_info & IP_FW_PORT_TEE_FLAG) != 0)
990 clone = m_dup(m, MB_DONTWAIT);
992 /* Restore packet header fields to original values */
994 ip->ip_len = htons(ip->ip_len);
995 ip->ip_off = htons(ip->ip_off);
997 /* Deliver packet to divert input routine */
998 divert_packet(m, 1, divert_info & 0xffff);
999 ipstat.ips_delivered++;
1001 /* If 'tee', continue with original packet */
1005 ip = mtod(m, struct ip *);
1008 * Jump backwards to complete processing of the
1009 * packet. But first clear divert_info to avoid
1010 * entering this block again.
1011 * We do not need to clear args.divert_rule
1012 * or args.next_hop as they will not be used.
1014 * XXX Better safe than sorry, remove the DIVERT tag.
1016 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL);
1018 m_tag_delete(m, mtag);
1027 * enforce IPsec policy checking if we are seeing last header.
1028 * note that we do not visit this with protocols with pcb layer
1029 * code - like udp/tcp/raw ip.
1031 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) &&
1032 ipsec4_in_reject(m, NULL)) {
1033 ipsecstat.in_polvio++;
1039 * enforce IPsec policy checking if we are seeing last header.
1040 * note that we do not visit this with protocols with pcb layer
1041 * code - like udp/tcp/raw ip.
1043 if (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) {
1045 * Check if the packet has already had IPsec processing
1046 * done. If so, then just pass it along. This tag gets
1047 * set during AH, ESP, etc. input handling, before the
1048 * packet is returned to the ip input queue for delivery.
1050 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
1053 tdbi = (struct tdb_ident *)m_tag_data(mtag);
1054 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
1056 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
1057 IP_FORWARDING, &error);
1061 * Check security policy against packet attributes.
1063 error = ipsec_in_reject(sp, m);
1066 /* XXX error stat??? */
1068 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
1075 #endif /* FAST_IPSEC */
1077 ipstat.ips_delivered++;
1078 if (needredispatch) {
1079 struct netmsg_transport_packet *msg;
1082 ip->ip_off = htons(ip->ip_off);
1083 ip->ip_len = htons(ip->ip_len);
1084 port = ip_mport_in(&m);
1088 msg = kmalloc(sizeof(struct netmsg_transport_packet), M_LWKTMSG,
1089 M_INTWAIT | M_NULLOK);
1093 netmsg_init(&msg->nm_netmsg, &netisr_afree_rport, 0,
1094 transport_processing_handler);
1095 msg->nm_hlen = hlen;
1096 msg->nm_hasnexthop = (args.next_hop != NULL);
1097 if (msg->nm_hasnexthop)
1098 msg->nm_nexthop = *args.next_hop; /* structure copy */
1101 ip = mtod(m, struct ip *);
1102 ip->ip_len = ntohs(ip->ip_len);
1103 ip->ip_off = ntohs(ip->ip_off);
1104 lwkt_sendmsg(port, &msg->nm_netmsg.nm_lmsg);
1106 transport_processing_oncpu(m, hlen, ip, args.next_hop);
1115 * Take incoming datagram fragment and try to reassemble it into
1116 * whole datagram. If a chain for reassembly of this datagram already
1117 * exists, then it is given as fp; otherwise have to make a chain.
1119 * When IPDIVERT enabled, keep additional state with each packet that
1120 * tells us if we need to divert or tee the packet we're building.
1121 * In particular, *divinfo includes the port and TEE flag.
1124 static struct mbuf *
1125 ip_reass(struct mbuf *m, struct ipq *fp, struct ipq *where,
1128 struct ip *ip = mtod(m, struct ip *);
1129 struct mbuf *p = NULL, *q, *nq;
1131 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1138 * If the hardware has not done csum over this fragment
1139 * then csum_data is not valid at all.
1141 if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID))
1142 == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) {
1143 m->m_pkthdr.csum_data = 0;
1144 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
1148 * Presence of header sizes in mbufs
1149 * would confuse code below.
1155 * If first fragment to arrive, create a reassembly queue.
1158 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL)
1163 fp->ipq_ttl = IPFRAGTTL;
1164 fp->ipq_p = ip->ip_p;
1165 fp->ipq_id = ip->ip_id;
1166 fp->ipq_src = ip->ip_src;
1167 fp->ipq_dst = ip->ip_dst;
1169 m->m_nextpkt = NULL;
1171 fp->ipq_div_info = 0;
1178 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1181 * Find a segment which begins after this one does.
1183 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
1184 if (GETIP(q)->ip_off > ip->ip_off)
1188 * If there is a preceding segment, it may provide some of
1189 * our data already. If so, drop the data from the incoming
1190 * segment. If it provides all of our data, drop us, otherwise
1191 * stick new segment in the proper place.
1193 * If some of the data is dropped from the the preceding
1194 * segment, then it's checksum is invalidated.
1197 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1199 if (i >= ip->ip_len)
1202 m->m_pkthdr.csum_flags = 0;
1206 m->m_nextpkt = p->m_nextpkt;
1209 m->m_nextpkt = fp->ipq_frags;
1214 * While we overlap succeeding segments trim them or,
1215 * if they are completely covered, dequeue them.
1217 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1219 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1220 if (i < GETIP(q)->ip_len) {
1221 GETIP(q)->ip_len -= i;
1222 GETIP(q)->ip_off += i;
1224 q->m_pkthdr.csum_flags = 0;
1229 ipstat.ips_fragdropped++;
1231 q->m_nextpkt = NULL;
1239 * Transfer firewall instructions to the fragment structure.
1240 * Only trust info in the fragment at offset 0.
1242 if (ip->ip_off == 0) {
1243 fp->ipq_div_info = *divinfo;
1245 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL);
1247 m_tag_delete(m, mtag);
1253 * Check for complete reassembly and perform frag per packet
1256 * Frag limiting is performed here so that the nth frag has
1257 * a chance to complete the packet before we drop the packet.
1258 * As a result, n+1 frags are actually allowed per packet, but
1259 * only n will ever be stored. (n = maxfragsperpacket.)
1263 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1264 if (GETIP(q)->ip_off != next) {
1265 if (fp->ipq_nfrags > maxfragsperpacket) {
1266 ipstat.ips_fragdropped += fp->ipq_nfrags;
1271 next += GETIP(q)->ip_len;
1273 /* Make sure the last packet didn't have the IP_MF flag */
1274 if (p->m_flags & M_FRAG) {
1275 if (fp->ipq_nfrags > maxfragsperpacket) {
1276 ipstat.ips_fragdropped += fp->ipq_nfrags;
1283 * Reassembly is complete. Make sure the packet is a sane size.
1287 if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
1288 ipstat.ips_toolong++;
1289 ipstat.ips_fragdropped += fp->ipq_nfrags;
1295 * Concatenate fragments.
1302 q->m_nextpkt = NULL;
1303 for (q = nq; q != NULL; q = nq) {
1305 q->m_nextpkt = NULL;
1306 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1307 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1312 * Clean up the 1's complement checksum. Carry over 16 bits must
1313 * be added back. This assumes no more then 65535 packet fragments
1314 * were reassembled. A second carry can also occur (but not a third).
1316 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) +
1317 (m->m_pkthdr.csum_data >> 16);
1318 if (m->m_pkthdr.csum_data > 0xFFFF)
1319 m->m_pkthdr.csum_data -= 0xFFFF;
1324 * Extract firewall instructions from the fragment structure.
1326 *divinfo = fp->ipq_div_info;
1330 * Create header for new ip packet by
1331 * modifying header of first packet;
1332 * dequeue and discard fragment reassembly header.
1333 * Make header visible.
1336 ip->ip_src = fp->ipq_src;
1337 ip->ip_dst = fp->ipq_dst;
1340 mpipe_free(&ipq_mpipe, fp);
1341 m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
1342 m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
1343 /* some debugging cruft by sklower, below, will go away soon */
1344 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1347 for (n = m; n; n = n->m_next)
1349 m->m_pkthdr.len = plen;
1357 ipstat.ips_fragdropped++;
1367 * Free a fragment reassembly header and all
1368 * associated datagrams.
1371 ip_freef(struct ipq *fp)
1375 while (fp->ipq_frags) {
1377 fp->ipq_frags = q->m_nextpkt;
1378 q->m_nextpkt = NULL;
1382 mpipe_free(&ipq_mpipe, fp);
1387 * IP timer processing;
1388 * if a timer expires on a reassembly
1389 * queue, discard it.
1398 for (i = 0; i < IPREASS_NHASH; i++) {
1402 while (fp != &ipq[i]) {
1405 if (fp->prev->ipq_ttl == 0) {
1406 ipstat.ips_fragtimeout += fp->prev->ipq_nfrags;
1412 * If we are over the maximum number of fragments
1413 * (due to the limit being lowered), drain off
1414 * enough to get down to the new limit.
1416 if (maxnipq >= 0 && nipq > maxnipq) {
1417 for (i = 0; i < IPREASS_NHASH; i++) {
1418 while (nipq > maxnipq &&
1419 (ipq[i].next != &ipq[i])) {
1420 ipstat.ips_fragdropped +=
1421 ipq[i].next->ipq_nfrags;
1422 ip_freef(ipq[i].next);
1431 * Drain off all datagram fragments.
1438 for (i = 0; i < IPREASS_NHASH; i++) {
1439 while (ipq[i].next != &ipq[i]) {
1440 ipstat.ips_fragdropped += ipq[i].next->ipq_nfrags;
1441 ip_freef(ipq[i].next);
1448 * Do option processing on a datagram,
1449 * possibly discarding it if bad options are encountered,
1450 * or forwarding it if source-routed.
1451 * The pass argument is used when operating in the IPSTEALTH
1452 * mode to tell what options to process:
1453 * [LS]SRR (pass 0) or the others (pass 1).
1454 * The reason for as many as two passes is that when doing IPSTEALTH,
1455 * non-routing options should be processed only if the packet is for us.
1456 * Returns 1 if packet has been forwarded/freed,
1457 * 0 if the packet should be processed further.
1460 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
1462 struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET };
1463 struct ip *ip = mtod(m, struct ip *);
1465 struct in_ifaddr *ia;
1466 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB;
1467 boolean_t forward = FALSE;
1468 struct in_addr *sin, dst;
1472 cp = (u_char *)(ip + 1);
1473 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1474 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1475 opt = cp[IPOPT_OPTVAL];
1476 if (opt == IPOPT_EOL)
1478 if (opt == IPOPT_NOP)
1481 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1482 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1485 optlen = cp[IPOPT_OLEN];
1486 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1487 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1497 * Source routing with record.
1498 * Find interface with current destination address.
1499 * If none on this machine then drop if strictly routed,
1500 * or do nothing if loosely routed.
1501 * Record interface address and bring up next address
1502 * component. If strictly routed make sure next
1503 * address is on directly accessible net.
1507 if (ipstealth && pass > 0)
1509 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1510 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1513 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1514 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1517 ipaddr.sin_addr = ip->ip_dst;
1518 ia = (struct in_ifaddr *)
1519 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1521 if (opt == IPOPT_SSRR) {
1522 type = ICMP_UNREACH;
1523 code = ICMP_UNREACH_SRCFAIL;
1526 if (!ip_dosourceroute)
1527 goto nosourcerouting;
1529 * Loose routing, and not at next destination
1530 * yet; nothing to do except forward.
1534 off--; /* 0 origin */
1535 if (off > optlen - (int)sizeof(struct in_addr)) {
1537 * End of source route. Should be for us.
1539 if (!ip_acceptsourceroute)
1540 goto nosourcerouting;
1541 save_rte(cp, ip->ip_src);
1546 if (!ip_dosourceroute) {
1548 char buf[sizeof "aaa.bbb.ccc.ddd"];
1551 * Acting as a router, so generate ICMP
1554 strcpy(buf, inet_ntoa(ip->ip_dst));
1556 "attempted source route from %s to %s\n",
1557 inet_ntoa(ip->ip_src), buf);
1558 type = ICMP_UNREACH;
1559 code = ICMP_UNREACH_SRCFAIL;
1563 * Not acting as a router,
1567 ipstat.ips_cantforward++;
1574 * locate outgoing interface
1576 memcpy(&ipaddr.sin_addr, cp + off,
1577 sizeof ipaddr.sin_addr);
1579 if (opt == IPOPT_SSRR) {
1580 #define INA struct in_ifaddr *
1581 #define SA struct sockaddr *
1582 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr))
1584 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1586 ia = ip_rtaddr(ipaddr.sin_addr,
1587 &ipforward_rt[mycpuid]);
1589 type = ICMP_UNREACH;
1590 code = ICMP_UNREACH_SRCFAIL;
1593 ip->ip_dst = ipaddr.sin_addr;
1594 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1595 sizeof(struct in_addr));
1596 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1598 * Let ip_intr's mcast routing check handle mcast pkts
1600 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1604 if (ipstealth && pass == 0)
1606 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1607 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1610 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1611 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1615 * If no space remains, ignore.
1617 off--; /* 0 origin */
1618 if (off > optlen - (int)sizeof(struct in_addr))
1620 memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1621 sizeof ipaddr.sin_addr);
1623 * locate outgoing interface; if we're the destination,
1624 * use the incoming interface (should be same).
1626 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL &&
1627 (ia = ip_rtaddr(ipaddr.sin_addr,
1628 &ipforward_rt[mycpuid]))
1630 type = ICMP_UNREACH;
1631 code = ICMP_UNREACH_HOST;
1634 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1635 sizeof(struct in_addr));
1636 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1640 if (ipstealth && pass == 0)
1642 code = cp - (u_char *)ip;
1643 if (optlen < 4 || optlen > 40) {
1644 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1647 if ((off = cp[IPOPT_OFFSET]) < 5) {
1648 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1651 if (off > optlen - (int)sizeof(int32_t)) {
1652 cp[IPOPT_OFFSET + 1] += (1 << 4);
1653 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1654 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1659 off--; /* 0 origin */
1660 sin = (struct in_addr *)(cp + off);
1661 switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1663 case IPOPT_TS_TSONLY:
1666 case IPOPT_TS_TSANDADDR:
1667 if (off + sizeof(n_time) +
1668 sizeof(struct in_addr) > optlen) {
1669 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1672 ipaddr.sin_addr = dst;
1673 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1677 memcpy(sin, &IA_SIN(ia)->sin_addr,
1678 sizeof(struct in_addr));
1679 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1680 off += sizeof(struct in_addr);
1683 case IPOPT_TS_PRESPEC:
1684 if (off + sizeof(n_time) +
1685 sizeof(struct in_addr) > optlen) {
1686 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1689 memcpy(&ipaddr.sin_addr, sin,
1690 sizeof(struct in_addr));
1691 if (ifa_ifwithaddr((SA)&ipaddr) == NULL)
1693 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1694 off += sizeof(struct in_addr);
1698 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1702 memcpy(cp + off, &ntime, sizeof(n_time));
1703 cp[IPOPT_OFFSET] += sizeof(n_time);
1706 if (forward && ipforwarding) {
1707 ip_forward(m, TRUE, next_hop);
1712 icmp_error(m, type, code, 0, 0);
1713 ipstat.ips_badoptions++;
1718 * Given address of next destination (final or next hop),
1719 * return internet address info of interface to be used to get there.
1722 ip_rtaddr(struct in_addr dst, struct route *ro)
1724 struct sockaddr_in *sin;
1726 sin = (struct sockaddr_in *)&ro->ro_dst;
1728 if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) {
1729 if (ro->ro_rt != NULL) {
1733 sin->sin_family = AF_INET;
1734 sin->sin_len = sizeof *sin;
1735 sin->sin_addr = dst;
1736 rtalloc_ign(ro, RTF_PRCLONING);
1739 if (ro->ro_rt == NULL)
1742 return (ifatoia(ro->ro_rt->rt_ifa));
1746 * Save incoming source route for use in replies,
1747 * to be picked up later by ip_srcroute if the receiver is interested.
1750 save_rte(u_char *option, struct in_addr dst)
1754 olen = option[IPOPT_OLEN];
1757 kprintf("save_rte: olen %d\n", olen);
1759 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1761 bcopy(option, ip_srcrt.srcopt, olen);
1762 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1767 * Retrieve incoming source route for use in replies,
1768 * in the same form used by setsockopt.
1769 * The first hop is placed before the options, will be removed later.
1774 struct in_addr *p, *q;
1779 m = m_get(MB_DONTWAIT, MT_HEADER);
1783 #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1785 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1786 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1790 kprintf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1794 * First save first hop for return route
1796 p = &ip_srcrt.route[ip_nhops - 1];
1797 *(mtod(m, struct in_addr *)) = *p--;
1800 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1804 * Copy option fields and padding (nop) to mbuf.
1806 ip_srcrt.nop = IPOPT_NOP;
1807 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1808 memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &ip_srcrt.nop,
1810 q = (struct in_addr *)(mtod(m, caddr_t) +
1811 sizeof(struct in_addr) + OPTSIZ);
1814 * Record return path as an IP source route,
1815 * reversing the path (pointers are now aligned).
1817 while (p >= ip_srcrt.route) {
1820 kprintf(" %x", ntohl(q->s_addr));
1825 * Last hop goes to final destination.
1830 kprintf(" %x\n", ntohl(q->s_addr));
1836 * Strip out IP options.
1839 ip_stripoptions(struct mbuf *m)
1842 struct ip *ip = mtod(m, struct ip *);
1846 optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1847 opts = (caddr_t)(ip + 1);
1848 datalen = m->m_len - (sizeof(struct ip) + optlen);
1849 bcopy(opts + optlen, opts, datalen);
1851 if (m->m_flags & M_PKTHDR)
1852 m->m_pkthdr.len -= optlen;
1853 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1856 u_char inetctlerrmap[PRC_NCMDS] = {
1858 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1859 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1860 EMSGSIZE, EHOSTUNREACH, 0, 0,
1862 ENOPROTOOPT, ECONNREFUSED
1866 * Forward a packet. If some error occurs return the sender
1867 * an icmp packet. Note we can't always generate a meaningful
1868 * icmp message because icmp doesn't have a large enough repertoire
1869 * of codes and types.
1871 * If not forwarding, just drop the packet. This could be confusing
1872 * if ipforwarding was zero but some routing protocol was advancing
1873 * us as a gateway to somewhere. However, we must let the routing
1874 * protocol deal with that.
1876 * The using_srcrt parameter indicates whether the packet is being forwarded
1877 * via a source route.
1880 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop)
1882 struct ip *ip = mtod(m, struct ip *);
1883 struct sockaddr_in *ipforward_rtaddr;
1885 int error, type = 0, code = 0, destmtu = 0;
1888 struct in_addr pkt_dst;
1890 struct route *cache_rt = &ipforward_rt[mycpuid];
1894 * Cache the destination address of the packet; this may be
1895 * changed by use of 'ipfw fwd'.
1897 pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst;
1901 kprintf("forward: src %x dst %x ttl %x\n",
1902 ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl);
1905 if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) {
1906 ipstat.ips_cantforward++;
1910 if (!ipstealth && ip->ip_ttl <= IPTTLDEC) {
1911 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1915 ipforward_rtaddr = (struct sockaddr_in *) &cache_rt->ro_dst;
1916 if (cache_rt->ro_rt == NULL ||
1917 ipforward_rtaddr->sin_addr.s_addr != pkt_dst.s_addr) {
1918 if (cache_rt->ro_rt != NULL) {
1919 RTFREE(cache_rt->ro_rt);
1920 cache_rt->ro_rt = NULL;
1922 ipforward_rtaddr->sin_family = AF_INET;
1923 ipforward_rtaddr->sin_len = sizeof(struct sockaddr_in);
1924 ipforward_rtaddr->sin_addr = pkt_dst;
1925 rtalloc_ign(cache_rt, RTF_PRCLONING);
1926 if (cache_rt->ro_rt == NULL) {
1927 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1931 rt = cache_rt->ro_rt;
1934 * Save the IP header and at most 8 bytes of the payload,
1935 * in case we need to generate an ICMP message to the src.
1937 * XXX this can be optimized a lot by saving the data in a local
1938 * buffer on the stack (72 bytes at most), and only allocating the
1939 * mbuf if really necessary. The vast majority of the packets
1940 * are forwarded without having to send an ICMP back (either
1941 * because unnecessary, or because rate limited), so we are
1942 * really we are wasting a lot of work here.
1944 * We don't use m_copy() because it might return a reference
1945 * to a shared cluster. Both this function and ip_output()
1946 * assume exclusive access to the IP header in `m', so any
1947 * data in a cluster may change before we reach icmp_error().
1949 MGETHDR(mcopy, MB_DONTWAIT, m->m_type);
1950 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, MB_DONTWAIT)) {
1952 * It's probably ok if the pkthdr dup fails (because
1953 * the deep copy of the tag chain failed), but for now
1954 * be conservative and just discard the copy since
1955 * code below may some day want the tags.
1960 if (mcopy != NULL) {
1961 mcopy->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8,
1963 mcopy->m_pkthdr.len = mcopy->m_len;
1964 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1968 ip->ip_ttl -= IPTTLDEC;
1971 * If forwarding packet using same interface that it came in on,
1972 * perhaps should send a redirect to sender to shortcut a hop.
1973 * Only send redirect if source is sending directly to us,
1974 * and if packet was not source routed (or has any options).
1975 * Also, don't send redirect if forwarding using a default route
1976 * or a route modified by a redirect.
1978 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1979 !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) &&
1980 satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY &&
1981 ipsendredirects && !using_srcrt && next_hop == NULL) {
1982 u_long src = ntohl(ip->ip_src.s_addr);
1983 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa;
1985 if (rt_ifa != NULL &&
1986 (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) {
1987 if (rt->rt_flags & RTF_GATEWAY)
1988 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1990 dest = pkt_dst.s_addr;
1992 * Router requirements says to only send
1995 type = ICMP_REDIRECT;
1996 code = ICMP_REDIRECT_HOST;
1999 kprintf("redirect (%d) to %x\n", code, dest);
2004 if (next_hop != NULL) {
2005 /* Pass IPFORWARD info if available */
2006 tag.mh_type = MT_TAG;
2007 tag.mh_flags = PACKET_TAG_IPFORWARD;
2008 tag.mh_data = (caddr_t)next_hop;
2010 m = (struct mbuf *)&tag;
2013 error = ip_output(m, NULL, cache_rt, IP_FORWARDING, NULL,
2016 ipstat.ips_forward++;
2019 /* ipflow_create() will free mcopy */
2020 ipflow_create(cache_rt, mcopy);
2022 return; /* most common case */
2024 ipstat.ips_redirectsent++;
2027 ipstat.ips_cantforward++;
2034 * Send ICMP message.
2039 case 0: /* forwarded, but need redirect */
2040 /* type, code set above */
2043 case ENETUNREACH: /* shouldn't happen, checked above */
2048 type = ICMP_UNREACH;
2049 code = ICMP_UNREACH_HOST;
2053 type = ICMP_UNREACH;
2054 code = ICMP_UNREACH_NEEDFRAG;
2057 * If the packet is routed over IPsec tunnel, tell the
2058 * originator the tunnel MTU.
2059 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2062 if (cache_rt->ro_rt != NULL) {
2063 struct secpolicy *sp = NULL;
2068 sp = ipsec4_getpolicybyaddr(mcopy,
2074 destmtu = cache_rt->ro_rt->rt_ifp->if_mtu;
2076 /* count IPsec header size */
2077 ipsechdr = ipsec4_hdrsiz(mcopy,
2082 * find the correct route for outer IPv4
2083 * header, compute tunnel MTU.
2086 if (sp->req != NULL && sp->req->sav != NULL &&
2087 sp->req->sav->sah != NULL) {
2088 ro = &sp->req->sav->sah->sa_route;
2089 if (ro->ro_rt != NULL &&
2090 ro->ro_rt->rt_ifp != NULL) {
2092 ro->ro_rt->rt_ifp->if_mtu;
2093 destmtu -= ipsechdr;
2102 * If the packet is routed over IPsec tunnel, tell the
2103 * originator the tunnel MTU.
2104 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2107 if (cache_rt->ro_rt != NULL) {
2108 struct secpolicy *sp = NULL;
2113 sp = ipsec_getpolicybyaddr(mcopy,
2119 destmtu = cache_rt->ro_rt->rt_ifp->if_mtu;
2121 /* count IPsec header size */
2122 ipsechdr = ipsec4_hdrsiz(mcopy,
2127 * find the correct route for outer IPv4
2128 * header, compute tunnel MTU.
2131 if (sp->req != NULL &&
2132 sp->req->sav != NULL &&
2133 sp->req->sav->sah != NULL) {
2134 ro = &sp->req->sav->sah->sa_route;
2135 if (ro->ro_rt != NULL &&
2136 ro->ro_rt->rt_ifp != NULL) {
2138 ro->ro_rt->rt_ifp->if_mtu;
2139 destmtu -= ipsechdr;
2146 #else /* !IPSEC && !FAST_IPSEC */
2147 if (cache_rt->ro_rt != NULL)
2148 destmtu = cache_rt->ro_rt->rt_ifp->if_mtu;
2150 ipstat.ips_cantfrag++;
2155 * A router should not generate ICMP_SOURCEQUENCH as
2156 * required in RFC1812 Requirements for IP Version 4 Routers.
2157 * Source quench could be a big problem under DoS attacks,
2158 * or if the underlying interface is rate-limited.
2159 * Those who need source quench packets may re-enable them
2160 * via the net.inet.ip.sendsourcequench sysctl.
2162 if (!ip_sendsourcequench) {
2166 type = ICMP_SOURCEQUENCH;
2171 case EACCES: /* ipfw denied packet */
2175 icmp_error(mcopy, type, code, dest, destmtu);
2179 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
2182 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
2186 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
2187 SCM_TIMESTAMP, SOL_SOCKET);
2189 mp = &(*mp)->m_next;
2191 if (inp->inp_flags & INP_RECVDSTADDR) {
2192 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
2193 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2195 mp = &(*mp)->m_next;
2197 if (inp->inp_flags & INP_RECVTTL) {
2198 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
2199 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
2201 mp = &(*mp)->m_next;
2205 * Moving these out of udp_input() made them even more broken
2206 * than they already were.
2208 /* options were tossed already */
2209 if (inp->inp_flags & INP_RECVOPTS) {
2210 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
2211 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
2213 mp = &(*mp)->m_next;
2215 /* ip_srcroute doesn't do what we want here, need to fix */
2216 if (inp->inp_flags & INP_RECVRETOPTS) {
2217 *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
2218 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
2220 mp = &(*mp)->m_next;
2223 if (inp->inp_flags & INP_RECVIF) {
2226 struct sockaddr_dl sdl;
2229 struct sockaddr_dl *sdp;
2230 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
2232 if (((ifp = m->m_pkthdr.rcvif)) &&
2233 ((ifp->if_index != 0) && (ifp->if_index <= if_index))) {
2234 sdp = IF_LLSOCKADDR(ifp);
2236 * Change our mind and don't try copy.
2238 if ((sdp->sdl_family != AF_LINK) ||
2239 (sdp->sdl_len > sizeof(sdlbuf))) {
2242 bcopy(sdp, sdl2, sdp->sdl_len);
2246 offsetof(struct sockaddr_dl, sdl_data[0]);
2247 sdl2->sdl_family = AF_LINK;
2248 sdl2->sdl_index = 0;
2249 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2251 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2252 IP_RECVIF, IPPROTO_IP);
2254 mp = &(*mp)->m_next;
2259 * XXX these routines are called from the upper part of the kernel.
2261 * They could also be moved to ip_mroute.c, since all the RSVP
2262 * handling is done there already.
2265 ip_rsvp_init(struct socket *so)
2267 if (so->so_type != SOCK_RAW ||
2268 so->so_proto->pr_protocol != IPPROTO_RSVP)
2271 if (ip_rsvpd != NULL)
2276 * This may seem silly, but we need to be sure we don't over-increment
2277 * the RSVP counter, in case something slips up.
2292 * This may seem silly, but we need to be sure we don't over-decrement
2293 * the RSVP counter, in case something slips up.
2303 rsvp_input(struct mbuf *m, ...) /* XXX must fixup manually */
2309 off = __va_arg(ap, int);
2310 proto = __va_arg(ap, int);
2313 if (rsvp_input_p) { /* call the real one if loaded */
2314 rsvp_input_p(m, off, proto);
2318 /* Can still get packets with rsvp_on = 0 if there is a local member
2319 * of the group to which the RSVP packet is addressed. But in this
2320 * case we want to throw the packet away.
2328 if (ip_rsvpd != NULL) {
2329 rip_input(m, off, proto);
2332 /* Drop the packet */