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 1.111 2008/10/21 13:51:01 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>
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>
117 #include <sys/thread2.h>
118 #include <sys/msgport2.h>
119 #include <net/netmsg2.h>
121 #include <sys/socketvar.h>
123 #include <net/ipfw/ip_fw.h>
124 #include <net/dummynet/ip_dummynet.h>
127 #include <netinet6/ipsec.h>
128 #include <netproto/key/key.h>
132 #include <netproto/ipsec/ipsec.h>
133 #include <netproto/ipsec/key.h>
137 static int ip_rsvp_on;
138 struct socket *ip_rsvpd;
141 TUNABLE_INT("net.inet.ip.mpsafe", &ip_mpsafe);
143 int ipforwarding = 0;
144 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
145 &ipforwarding, 0, "Enable IP forwarding between interfaces");
147 static int ipsendredirects = 1; /* XXX */
148 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
149 &ipsendredirects, 0, "Enable sending IP redirects");
151 int ip_defttl = IPDEFTTL;
152 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
153 &ip_defttl, 0, "Maximum TTL on IP packets");
155 static int ip_dosourceroute = 0;
156 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
157 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
159 static int ip_acceptsourceroute = 0;
160 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
161 CTLFLAG_RW, &ip_acceptsourceroute, 0,
162 "Enable accepting source routed IP packets");
164 static int ip_keepfaith = 0;
165 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
167 "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
169 static int nipq = 0; /* total # of reass queues */
171 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
173 "Maximum number of IPv4 fragment reassembly queue entries");
175 static int maxfragsperpacket;
176 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
177 &maxfragsperpacket, 0,
178 "Maximum number of IPv4 fragments allowed per packet");
180 static int ip_sendsourcequench = 0;
181 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
182 &ip_sendsourcequench, 0,
183 "Enable the transmission of source quench packets");
185 int ip_do_randomid = 1;
186 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
188 "Assign random ip_id values");
190 * XXX - Setting ip_checkinterface mostly implements the receive side of
191 * the Strong ES model described in RFC 1122, but since the routing table
192 * and transmit implementation do not implement the Strong ES model,
193 * setting this to 1 results in an odd hybrid.
195 * XXX - ip_checkinterface currently must be disabled if you use ipnat
196 * to translate the destination address to another local interface.
198 * XXX - ip_checkinterface must be disabled if you add IP aliases
199 * to the loopback interface instead of the interface where the
200 * packets for those addresses are received.
202 static int ip_checkinterface = 0;
203 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
204 &ip_checkinterface, 0, "Verify packet arrives on correct interface");
207 static int ipprintfs = 0;
210 extern int udp_mpsafe_proto;
211 extern int tcp_mpsafe_proto;
213 extern struct domain inetdomain;
214 extern struct protosw inetsw[];
215 u_char ip_protox[IPPROTO_MAX];
216 struct in_ifaddrhead in_ifaddrheads[MAXCPU]; /* first inet address */
217 struct in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU];
218 /* inet addr hash table */
219 u_long in_ifaddrhmask; /* mask for hash table */
221 struct ip_stats ipstats_percpu[MAXCPU];
224 sysctl_ipstats(SYSCTL_HANDLER_ARGS)
228 for (cpu = 0; cpu < ncpus; ++cpu) {
229 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu],
230 sizeof(struct ip_stats))))
232 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu],
233 sizeof(struct ip_stats))))
239 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
240 0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics");
242 SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
243 &ipstat, ip_stats, "IP statistics");
246 /* Packet reassembly stuff */
247 #define IPREASS_NHASH_LOG2 6
248 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
249 #define IPREASS_HMASK (IPREASS_NHASH - 1)
250 #define IPREASS_HASH(x,y) \
251 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
253 static struct ipq ipq[IPREASS_NHASH];
256 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
257 &ip_mtu, 0, "Default MTU");
261 static int ipstealth = 0;
262 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, "");
264 static const int ipstealth = 0;
267 struct mbuf *(*ip_divert_p)(struct mbuf *, int, int);
269 struct pfil_head inet_pfil_hook;
272 * struct ip_srcrt_opt is used to store packet state while it travels
275 * XXX Note that the code even makes assumptions on the size and
276 * alignment of fields inside struct ip_srcrt so e.g. adding some
277 * fields will break the code. This needs to be fixed.
279 * We need to save the IP options in case a protocol wants to respond
280 * to an incoming packet over the same route if the packet got here
281 * using IP source routing. This allows connection establishment and
282 * maintenance when the remote end is on a network that is not known
286 struct in_addr dst; /* final destination */
287 char nop; /* one NOP to align */
288 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
289 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
292 struct ip_srcrt_opt {
294 struct ip_srcrt ip_srcrt;
297 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management");
298 static struct malloc_pipe ipq_mpipe;
300 static void save_rte(struct mbuf *, u_char *, struct in_addr);
301 static int ip_dooptions(struct mbuf *m, int, struct sockaddr_in *);
302 static void ip_freef(struct ipq *);
303 static void ip_input_handler(struct netmsg *);
306 * IP initialization: fill in IP protocol switch table.
307 * All protocols not implemented in kernel go to raw IP protocol handler.
320 * Make sure we can handle a reasonable number of fragments but
321 * cap it at 4000 (XXX).
323 mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq),
324 IFQ_MAXLEN, 4000, 0, NULL);
325 for (i = 0; i < ncpus; ++i) {
326 TAILQ_INIT(&in_ifaddrheads[i]);
327 in_ifaddrhashtbls[i] =
328 hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
330 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
333 for (i = 0; i < IPPROTO_MAX; i++)
334 ip_protox[i] = pr - inetsw;
335 for (pr = inetdomain.dom_protosw;
336 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
337 if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol) {
338 if (pr->pr_protocol != IPPROTO_RAW)
339 ip_protox[pr->pr_protocol] = pr - inetsw;
342 switch (pr->pr_protocol) {
344 if (tcp_mpsafe_proto)
345 pr->pr_flags |= PR_MPSAFE;
349 if (udp_mpsafe_proto)
350 pr->pr_flags |= PR_MPSAFE;
356 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
357 inet_pfil_hook.ph_af = AF_INET;
358 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) {
359 kprintf("%s: WARNING: unable to register pfil hook, "
360 "error %d\n", __func__, i);
363 for (i = 0; i < IPREASS_NHASH; i++)
364 ipq[i].next = ipq[i].prev = &ipq[i];
366 maxnipq = nmbclusters / 32;
367 maxfragsperpacket = 16;
369 ip_id = time_second & 0xffff;
372 * Initialize IP statistics counters for each CPU.
376 for (cpu = 0; cpu < ncpus; ++cpu) {
377 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats));
380 bzero(&ipstat, sizeof(struct ip_stats));
383 #if defined(IPSEC) || defined(FAST_IPSEC)
384 /* XXX IPSEC is not MPSAFE yet */
385 flags = NETISR_FLAG_NOTMPSAFE;
388 kprintf("ip: MPSAFE\n");
389 flags = NETISR_FLAG_MPSAFE;
391 flags = NETISR_FLAG_NOTMPSAFE;
394 netisr_register(NETISR_IP, ip_mport_in, ip_input_handler, flags);
398 * XXX watch out this one. It is perhaps used as a cache for
399 * the most recently used route ? it is cleared in in_addroute()
400 * when a new route is successfully created.
402 struct route ipforward_rt[MAXCPU];
404 /* Do transport protocol processing. */
406 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip)
408 const struct protosw *pr = &inetsw[ip_protox[ip->ip_p]];
411 * Switch out to protocol's input routine.
414 pr->pr_input(m, hlen, ip->ip_p);
419 transport_processing_handler(netmsg_t netmsg)
421 struct netmsg_packet *pmsg = (struct netmsg_packet *)netmsg;
425 ip = mtod(pmsg->nm_packet, struct ip *);
426 hlen = pmsg->nm_netmsg.nm_lmsg.u.ms_result;
428 transport_processing_oncpu(pmsg->nm_packet, hlen, ip);
429 /* netmsg was embedded in the mbuf, do not reply! */
433 ip_input_handler(struct netmsg *msg0)
435 struct mbuf *m = ((struct netmsg_packet *)msg0)->nm_packet;
438 /* msg0 was embedded in the mbuf, do not reply! */
442 * IP input routine. Checksum and byte swap header. If fragmented
443 * try to reassemble. Process options. Pass to next level.
446 ip_input(struct mbuf *m)
449 struct in_ifaddr *ia = NULL;
450 struct in_ifaddr_container *iac;
453 struct in_addr pkt_dst;
454 boolean_t using_srcrt = FALSE; /* forward (by PFIL_HOOKS) */
455 boolean_t needredispatch = FALSE;
456 struct in_addr odst; /* original dst address(NAT) */
458 struct sockaddr_in *next_hop = NULL;
460 struct tdb_ident *tdbi;
461 struct secpolicy *sp;
467 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
469 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
470 KKASSERT(mtag != NULL);
471 next_hop = m_tag_data(mtag);
474 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
475 /* dummynet already filtered us */
476 ip = mtod(m, struct ip *);
477 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
483 /* length checks already done in ip_demux() */
484 KASSERT(m->m_len >= sizeof(ip), ("IP header not in one mbuf"));
486 ip = mtod(m, struct ip *);
488 if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
489 ipstat.ips_badvers++;
493 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
494 /* length checks already done in ip_demux() */
495 KASSERT(hlen >= sizeof(struct ip), ("IP header len too small"));
496 KASSERT(m->m_len >= hlen, ("packet shorter than IP header length"));
498 /* 127/8 must not appear on wire - RFC1122 */
499 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
500 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
501 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) {
502 ipstat.ips_badaddr++;
507 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
508 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
510 if (hlen == sizeof(struct ip)) {
511 sum = in_cksum_hdr(ip);
513 sum = in_cksum(m, hlen);
522 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
523 /* packet is dropped by traffic conditioner */
528 * Convert fields to host representation.
530 ip->ip_len = ntohs(ip->ip_len);
531 if (ip->ip_len < hlen) {
535 ip->ip_off = ntohs(ip->ip_off);
538 * Check that the amount of data in the buffers
539 * is as at least much as the IP header would have us expect.
540 * Trim mbufs if longer than we expect.
541 * Drop packet if shorter than we expect.
543 if (m->m_pkthdr.len < ip->ip_len) {
544 ipstat.ips_tooshort++;
547 if (m->m_pkthdr.len > ip->ip_len) {
548 if (m->m_len == m->m_pkthdr.len) {
549 m->m_len = ip->ip_len;
550 m->m_pkthdr.len = ip->ip_len;
552 m_adj(m, ip->ip_len - m->m_pkthdr.len);
554 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
556 * Bypass packet filtering for packets from a tunnel (gif).
558 if (ipsec_gethist(m, NULL))
564 * Right now when no processing on packet has done
565 * and it is still fresh out of network we do our black
567 * - Firewall: deny/allow/divert
568 * - Xlate: translate packet's addr/port (NAT).
569 * - Pipe: pass pkt through dummynet.
570 * - Wrap: fake packet's addr/port <unimpl.>
571 * - Encapsulate: put it in another IP and send out. <unimp.>
576 * If we've been forwarded from the output side, then
577 * skip the firewall a second time
579 if (next_hop != NULL)
583 if (!pfil_has_hooks(&inet_pfil_hook)) {
584 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
586 * Strip dummynet tags from stranded packets
588 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
589 KKASSERT(mtag != NULL);
590 m_tag_delete(m, mtag);
591 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
597 * Run through list of hooks for input packets.
599 * NB: Beware of the destination address changing (e.g.
600 * by NAT rewriting). When this happens, tell
601 * ip_forward to do the right thing.
604 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN))
606 if (m == NULL) /* consumed by filter */
608 ip = mtod(m, struct ip *);
609 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
610 using_srcrt = (odst.s_addr != ip->ip_dst.s_addr);
612 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
613 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
614 KKASSERT(mtag != NULL);
615 next_hop = m_tag_data(mtag);
617 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
621 if (m->m_pkthdr.fw_flags & FW_MBUF_REDISPATCH) {
622 needredispatch = TRUE;
623 m->m_pkthdr.fw_flags &= ~FW_MBUF_REDISPATCH;
627 * Process options and, if not destined for us,
628 * ship it on. ip_dooptions returns 1 when an
629 * error was detected (causing an icmp message
630 * to be sent and the original packet to be freed).
632 if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, next_hop))
635 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
636 * matter if it is destined to another node, or whether it is
637 * a multicast one, RSVP wants it! and prevents it from being forwarded
638 * anywhere else. Also checks if the rsvp daemon is running before
639 * grabbing the packet.
641 if (rsvp_on && ip->ip_p == IPPROTO_RSVP)
645 * Check our list of addresses, to see if the packet is for us.
646 * If we don't have any addresses, assume any unicast packet
647 * we receive might be for us (and let the upper layers deal
650 if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) &&
651 !(m->m_flags & (M_MCAST | M_BCAST)))
655 * Cache the destination address of the packet; this may be
656 * changed by use of 'ipfw fwd'.
658 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
661 * Enable a consistency check between the destination address
662 * and the arrival interface for a unicast packet (the RFC 1122
663 * strong ES model) if IP forwarding is disabled and the packet
664 * is not locally generated and the packet is not subject to
667 * XXX - Checking also should be disabled if the destination
668 * address is ipnat'ed to a different interface.
670 * XXX - Checking is incompatible with IP aliases added
671 * to the loopback interface instead of the interface where
672 * the packets are received.
674 checkif = ip_checkinterface &&
676 m->m_pkthdr.rcvif != NULL &&
677 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) &&
681 * Check for exact addresses in the hash bucket.
683 LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
687 * If the address matches, verify that the packet
688 * arrived via the correct interface if checking is
691 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
692 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
698 * Check for broadcast addresses.
700 * Only accept broadcast packets that arrive via the matching
701 * interface. Reception of forwarded directed broadcasts would
702 * be handled via ip_forward() and ether_output() with the loopback
703 * into the stack for SIMPLEX interfaces handled by ether_output().
705 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
706 struct ifaddr_container *ifac;
708 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid],
710 struct ifaddr *ifa = ifac->ifa;
712 if (ifa->ifa_addr == NULL) /* shutdown/startup race */
714 if (ifa->ifa_addr->sa_family != AF_INET)
717 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
720 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
723 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
728 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
729 struct in_multi *inm;
731 /* XXX Multicast is not MPSAFE yet */
734 if (ip_mrouter != NULL) {
736 * If we are acting as a multicast router, all
737 * incoming multicast packets are passed to the
738 * kernel-level multicast forwarding function.
739 * The packet is returned (relatively) intact; if
740 * ip_mforward() returns a non-zero value, the packet
741 * must be discarded, else it may be accepted below.
743 if (ip_mforward != NULL &&
744 ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) {
746 ipstat.ips_cantforward++;
752 * The process-level routing daemon needs to receive
753 * all multicast IGMP packets, whether or not this
754 * host belongs to their destination groups.
756 if (ip->ip_p == IPPROTO_IGMP) {
760 ipstat.ips_forward++;
763 * See if we belong to the destination multicast group on the
766 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
769 ipstat.ips_notmember++;
777 if (ip->ip_dst.s_addr == INADDR_BROADCAST)
779 if (ip->ip_dst.s_addr == INADDR_ANY)
783 * FAITH(Firewall Aided Internet Translator)
785 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
787 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
795 * Not for us; forward if possible and desirable.
798 ipstat.ips_cantforward++;
803 * Enforce inbound IPsec SPD.
805 if (ipsec4_in_reject(m, NULL)) {
806 ipsecstat.in_polvio++;
811 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
814 tdbi = (struct tdb_ident *)m_tag_data(mtag);
815 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
817 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
818 IP_FORWARDING, &error);
820 if (sp == NULL) { /* NB: can happen if error */
822 /*XXX error stat???*/
823 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
828 * Check security policy against packet attributes.
830 error = ipsec_in_reject(sp, m);
834 ipstat.ips_cantforward++;
838 ip_forward(m, using_srcrt, next_hop);
845 * IPSTEALTH: Process non-routing options only
846 * if the packet is destined for us.
849 hlen > sizeof(struct ip) &&
850 ip_dooptions(m, 1, next_hop))
853 /* Count the packet in the ip address stats */
855 ia->ia_ifa.if_ipackets++;
856 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
860 * If offset or IP_MF are set, must reassemble.
861 * Otherwise, nothing need be done.
862 * (We could look in the reassembly queue to see
863 * if the packet was previously fragmented,
864 * but it's not worth the time; just let them time out.)
866 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
868 * Attempt reassembly; if it succeeds, proceed.
869 * ip_reass() will return a different mbuf.
874 ip = mtod(m, struct ip *);
876 /* Get the header length of the reassembled packet */
877 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
879 needredispatch = TRUE;
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) &&
891 ipsec4_in_reject(m, NULL)) {
892 ipsecstat.in_polvio++;
898 * enforce IPsec policy checking if we are seeing last header.
899 * note that we do not visit this with protocols with pcb layer
900 * code - like udp/tcp/raw ip.
902 if (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) {
904 * Check if the packet has already had IPsec processing
905 * done. If so, then just pass it along. This tag gets
906 * set during AH, ESP, etc. input handling, before the
907 * packet is returned to the ip input queue for delivery.
909 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
912 tdbi = (struct tdb_ident *)m_tag_data(mtag);
913 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
915 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
916 IP_FORWARDING, &error);
920 * Check security policy against packet attributes.
922 error = ipsec_in_reject(sp, m);
925 /* XXX error stat??? */
927 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
934 #endif /* FAST_IPSEC */
936 ipstat.ips_delivered++;
937 if (needredispatch) {
938 struct netmsg_packet *pmsg;
941 ip->ip_off = htons(ip->ip_off);
942 ip->ip_len = htons(ip->ip_len);
943 port = ip_mport_in(&m);
947 pmsg = &m->m_hdr.mh_netmsg;
948 netmsg_init(&pmsg->nm_netmsg, &netisr_apanic_rport, MSGF_MPSAFE,
949 transport_processing_handler);
951 pmsg->nm_netmsg.nm_lmsg.u.ms_result = hlen;
953 ip = mtod(m, struct ip *);
954 ip->ip_len = ntohs(ip->ip_len);
955 ip->ip_off = ntohs(ip->ip_off);
956 lwkt_sendmsg(port, &pmsg->nm_netmsg.nm_lmsg);
958 transport_processing_oncpu(m, hlen, ip);
967 * Take incoming datagram fragment and try to reassemble it into
968 * whole datagram. If a chain for reassembly of this datagram already
969 * exists, then it is given as fp; otherwise have to make a chain.
972 ip_reass(struct mbuf *m)
974 struct ip *ip = mtod(m, struct ip *);
975 struct mbuf *p = NULL, *q, *nq;
977 struct ipq *fp = NULL;
978 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
982 /* If maxnipq is 0, never accept fragments. */
984 ipstat.ips_fragments++;
985 ipstat.ips_fragdropped++;
990 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
992 * Look for queue of fragments of this datagram.
994 for (fp = ipq[sum].next; fp != &ipq[sum]; fp = fp->next)
995 if (ip->ip_id == fp->ipq_id &&
996 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
997 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
998 ip->ip_p == fp->ipq_p)
1004 * Enforce upper bound on number of fragmented packets
1005 * for which we attempt reassembly;
1006 * If maxnipq is -1, accept all fragments without limitation.
1008 if (nipq > maxnipq && maxnipq > 0) {
1010 * drop something from the tail of the current queue
1011 * before proceeding further
1013 if (ipq[sum].prev == &ipq[sum]) { /* gak */
1014 for (i = 0; i < IPREASS_NHASH; i++) {
1015 if (ipq[i].prev != &ipq[i]) {
1016 ipstat.ips_fragtimeout +=
1017 ipq[i].prev->ipq_nfrags;
1018 ip_freef(ipq[i].prev);
1023 ipstat.ips_fragtimeout +=
1024 ipq[sum].prev->ipq_nfrags;
1025 ip_freef(ipq[sum].prev);
1030 * Adjust ip_len to not reflect header,
1031 * convert offset of this to bytes.
1034 if (ip->ip_off & IP_MF) {
1036 * Make sure that fragments have a data length
1037 * that's a non-zero multiple of 8 bytes.
1039 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1040 ipstat.ips_toosmall++; /* XXX */
1044 m->m_flags |= M_FRAG;
1046 m->m_flags &= ~M_FRAG;
1049 ipstat.ips_fragments++;
1050 m->m_pkthdr.header = ip;
1053 * If the hardware has not done csum over this fragment
1054 * then csum_data is not valid at all.
1056 if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID))
1057 == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) {
1058 m->m_pkthdr.csum_data = 0;
1059 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
1063 * Presence of header sizes in mbufs
1064 * would confuse code below.
1070 * If first fragment to arrive, create a reassembly queue.
1073 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL)
1075 insque(fp, &ipq[sum]);
1078 fp->ipq_ttl = IPFRAGTTL;
1079 fp->ipq_p = ip->ip_p;
1080 fp->ipq_id = ip->ip_id;
1081 fp->ipq_src = ip->ip_src;
1082 fp->ipq_dst = ip->ip_dst;
1084 m->m_nextpkt = NULL;
1090 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1093 * Find a segment which begins after this one does.
1095 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
1096 if (GETIP(q)->ip_off > ip->ip_off)
1100 * If there is a preceding segment, it may provide some of
1101 * our data already. If so, drop the data from the incoming
1102 * segment. If it provides all of our data, drop us, otherwise
1103 * stick new segment in the proper place.
1105 * If some of the data is dropped from the the preceding
1106 * segment, then it's checksum is invalidated.
1109 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1111 if (i >= ip->ip_len)
1114 m->m_pkthdr.csum_flags = 0;
1118 m->m_nextpkt = p->m_nextpkt;
1121 m->m_nextpkt = fp->ipq_frags;
1126 * While we overlap succeeding segments trim them or,
1127 * if they are completely covered, dequeue them.
1129 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1131 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1132 if (i < GETIP(q)->ip_len) {
1133 GETIP(q)->ip_len -= i;
1134 GETIP(q)->ip_off += i;
1136 q->m_pkthdr.csum_flags = 0;
1141 ipstat.ips_fragdropped++;
1143 q->m_nextpkt = NULL;
1149 * Check for complete reassembly and perform frag per packet
1152 * Frag limiting is performed here so that the nth frag has
1153 * a chance to complete the packet before we drop the packet.
1154 * As a result, n+1 frags are actually allowed per packet, but
1155 * only n will ever be stored. (n = maxfragsperpacket.)
1159 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1160 if (GETIP(q)->ip_off != next) {
1161 if (fp->ipq_nfrags > maxfragsperpacket) {
1162 ipstat.ips_fragdropped += fp->ipq_nfrags;
1167 next += GETIP(q)->ip_len;
1169 /* Make sure the last packet didn't have the IP_MF flag */
1170 if (p->m_flags & M_FRAG) {
1171 if (fp->ipq_nfrags > maxfragsperpacket) {
1172 ipstat.ips_fragdropped += fp->ipq_nfrags;
1179 * Reassembly is complete. Make sure the packet is a sane size.
1183 if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
1184 ipstat.ips_toolong++;
1185 ipstat.ips_fragdropped += fp->ipq_nfrags;
1191 * Concatenate fragments.
1198 q->m_nextpkt = NULL;
1199 for (q = nq; q != NULL; q = nq) {
1201 q->m_nextpkt = NULL;
1202 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1203 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1208 * Clean up the 1's complement checksum. Carry over 16 bits must
1209 * be added back. This assumes no more then 65535 packet fragments
1210 * were reassembled. A second carry can also occur (but not a third).
1212 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) +
1213 (m->m_pkthdr.csum_data >> 16);
1214 if (m->m_pkthdr.csum_data > 0xFFFF)
1215 m->m_pkthdr.csum_data -= 0xFFFF;
1218 * Create header for new ip packet by
1219 * modifying header of first packet;
1220 * dequeue and discard fragment reassembly header.
1221 * Make header visible.
1224 ip->ip_src = fp->ipq_src;
1225 ip->ip_dst = fp->ipq_dst;
1228 mpipe_free(&ipq_mpipe, fp);
1229 m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
1230 m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
1231 /* some debugging cruft by sklower, below, will go away soon */
1232 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1235 for (n = m; n; n = n->m_next)
1237 m->m_pkthdr.len = plen;
1240 ipstat.ips_reassembled++;
1244 ipstat.ips_fragdropped++;
1254 * Free a fragment reassembly header and all
1255 * associated datagrams.
1258 ip_freef(struct ipq *fp)
1262 while (fp->ipq_frags) {
1264 fp->ipq_frags = q->m_nextpkt;
1265 q->m_nextpkt = NULL;
1269 mpipe_free(&ipq_mpipe, fp);
1274 * IP timer processing;
1275 * if a timer expires on a reassembly
1276 * queue, discard it.
1285 for (i = 0; i < IPREASS_NHASH; i++) {
1289 while (fp != &ipq[i]) {
1292 if (fp->prev->ipq_ttl == 0) {
1293 ipstat.ips_fragtimeout += fp->prev->ipq_nfrags;
1299 * If we are over the maximum number of fragments
1300 * (due to the limit being lowered), drain off
1301 * enough to get down to the new limit.
1303 if (maxnipq >= 0 && nipq > maxnipq) {
1304 for (i = 0; i < IPREASS_NHASH; i++) {
1305 while (nipq > maxnipq &&
1306 (ipq[i].next != &ipq[i])) {
1307 ipstat.ips_fragdropped +=
1308 ipq[i].next->ipq_nfrags;
1309 ip_freef(ipq[i].next);
1318 * Drain off all datagram fragments.
1325 for (i = 0; i < IPREASS_NHASH; i++) {
1326 while (ipq[i].next != &ipq[i]) {
1327 ipstat.ips_fragdropped += ipq[i].next->ipq_nfrags;
1328 ip_freef(ipq[i].next);
1335 * Do option processing on a datagram,
1336 * possibly discarding it if bad options are encountered,
1337 * or forwarding it if source-routed.
1338 * The pass argument is used when operating in the IPSTEALTH
1339 * mode to tell what options to process:
1340 * [LS]SRR (pass 0) or the others (pass 1).
1341 * The reason for as many as two passes is that when doing IPSTEALTH,
1342 * non-routing options should be processed only if the packet is for us.
1343 * Returns 1 if packet has been forwarded/freed,
1344 * 0 if the packet should be processed further.
1347 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
1349 struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET };
1350 struct ip *ip = mtod(m, struct ip *);
1352 struct in_ifaddr *ia;
1353 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB;
1354 boolean_t forward = FALSE;
1355 struct in_addr *sin, dst;
1359 cp = (u_char *)(ip + 1);
1360 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1361 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1362 opt = cp[IPOPT_OPTVAL];
1363 if (opt == IPOPT_EOL)
1365 if (opt == IPOPT_NOP)
1368 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1369 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1372 optlen = cp[IPOPT_OLEN];
1373 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1374 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1384 * Source routing with record.
1385 * Find interface with current destination address.
1386 * If none on this machine then drop if strictly routed,
1387 * or do nothing if loosely routed.
1388 * Record interface address and bring up next address
1389 * component. If strictly routed make sure next
1390 * address is on directly accessible net.
1394 if (ipstealth && pass > 0)
1396 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1397 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1400 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1401 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1404 ipaddr.sin_addr = ip->ip_dst;
1405 ia = (struct in_ifaddr *)
1406 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1408 if (opt == IPOPT_SSRR) {
1409 type = ICMP_UNREACH;
1410 code = ICMP_UNREACH_SRCFAIL;
1413 if (!ip_dosourceroute)
1414 goto nosourcerouting;
1416 * Loose routing, and not at next destination
1417 * yet; nothing to do except forward.
1421 off--; /* 0 origin */
1422 if (off > optlen - (int)sizeof(struct in_addr)) {
1424 * End of source route. Should be for us.
1426 if (!ip_acceptsourceroute)
1427 goto nosourcerouting;
1428 save_rte(m, cp, ip->ip_src);
1433 if (!ip_dosourceroute) {
1435 char buf[sizeof "aaa.bbb.ccc.ddd"];
1438 * Acting as a router, so generate ICMP
1441 strcpy(buf, inet_ntoa(ip->ip_dst));
1443 "attempted source route from %s to %s\n",
1444 inet_ntoa(ip->ip_src), buf);
1445 type = ICMP_UNREACH;
1446 code = ICMP_UNREACH_SRCFAIL;
1450 * Not acting as a router,
1454 ipstat.ips_cantforward++;
1461 * locate outgoing interface
1463 memcpy(&ipaddr.sin_addr, cp + off,
1464 sizeof ipaddr.sin_addr);
1466 if (opt == IPOPT_SSRR) {
1467 #define INA struct in_ifaddr *
1468 #define SA struct sockaddr *
1469 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr))
1471 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1473 ia = ip_rtaddr(ipaddr.sin_addr,
1474 &ipforward_rt[mycpuid]);
1476 type = ICMP_UNREACH;
1477 code = ICMP_UNREACH_SRCFAIL;
1480 ip->ip_dst = ipaddr.sin_addr;
1481 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1482 sizeof(struct in_addr));
1483 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1485 * Let ip_intr's mcast routing check handle mcast pkts
1487 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1491 if (ipstealth && pass == 0)
1493 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1494 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1497 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1498 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1502 * If no space remains, ignore.
1504 off--; /* 0 origin */
1505 if (off > optlen - (int)sizeof(struct in_addr))
1507 memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1508 sizeof ipaddr.sin_addr);
1510 * locate outgoing interface; if we're the destination,
1511 * use the incoming interface (should be same).
1513 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL &&
1514 (ia = ip_rtaddr(ipaddr.sin_addr,
1515 &ipforward_rt[mycpuid]))
1517 type = ICMP_UNREACH;
1518 code = ICMP_UNREACH_HOST;
1521 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1522 sizeof(struct in_addr));
1523 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1527 if (ipstealth && pass == 0)
1529 code = cp - (u_char *)ip;
1530 if (optlen < 4 || optlen > 40) {
1531 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1534 if ((off = cp[IPOPT_OFFSET]) < 5) {
1535 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1538 if (off > optlen - (int)sizeof(int32_t)) {
1539 cp[IPOPT_OFFSET + 1] += (1 << 4);
1540 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1541 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1546 off--; /* 0 origin */
1547 sin = (struct in_addr *)(cp + off);
1548 switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1550 case IPOPT_TS_TSONLY:
1553 case IPOPT_TS_TSANDADDR:
1554 if (off + sizeof(n_time) +
1555 sizeof(struct in_addr) > optlen) {
1556 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1559 ipaddr.sin_addr = dst;
1560 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1564 memcpy(sin, &IA_SIN(ia)->sin_addr,
1565 sizeof(struct in_addr));
1566 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1567 off += sizeof(struct in_addr);
1570 case IPOPT_TS_PRESPEC:
1571 if (off + sizeof(n_time) +
1572 sizeof(struct in_addr) > optlen) {
1573 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1576 memcpy(&ipaddr.sin_addr, sin,
1577 sizeof(struct in_addr));
1578 if (ifa_ifwithaddr((SA)&ipaddr) == NULL)
1580 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1581 off += sizeof(struct in_addr);
1585 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1589 memcpy(cp + off, &ntime, sizeof(n_time));
1590 cp[IPOPT_OFFSET] += sizeof(n_time);
1593 if (forward && ipforwarding) {
1594 ip_forward(m, TRUE, next_hop);
1599 icmp_error(m, type, code, 0, 0);
1600 ipstat.ips_badoptions++;
1605 * Given address of next destination (final or next hop),
1606 * return internet address info of interface to be used to get there.
1609 ip_rtaddr(struct in_addr dst, struct route *ro)
1611 struct sockaddr_in *sin;
1613 sin = (struct sockaddr_in *)&ro->ro_dst;
1615 if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) {
1616 if (ro->ro_rt != NULL) {
1620 sin->sin_family = AF_INET;
1621 sin->sin_len = sizeof *sin;
1622 sin->sin_addr = dst;
1623 rtalloc_ign(ro, RTF_PRCLONING);
1626 if (ro->ro_rt == NULL)
1629 return (ifatoia(ro->ro_rt->rt_ifa));
1633 * Save incoming source route for use in replies,
1634 * to be picked up later by ip_srcroute if the receiver is interested.
1637 save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1640 struct ip_srcrt_opt *opt;
1643 mtag = m_tag_get(PACKET_TAG_IPSRCRT, sizeof(*opt), MB_DONTWAIT);
1646 opt = m_tag_data(mtag);
1648 olen = option[IPOPT_OLEN];
1651 kprintf("save_rte: olen %d\n", olen);
1653 if (olen > sizeof(opt->ip_srcrt) - (1 + sizeof(dst))) {
1657 bcopy(option, opt->ip_srcrt.srcopt, olen);
1658 opt->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1659 opt->ip_srcrt.dst = dst;
1660 m_tag_prepend(m, mtag);
1664 * Retrieve incoming source route for use in replies,
1665 * in the same form used by setsockopt.
1666 * The first hop is placed before the options, will be removed later.
1669 ip_srcroute(struct mbuf *m0)
1671 struct in_addr *p, *q;
1674 struct ip_srcrt_opt *opt;
1679 mtag = m_tag_find(m0, PACKET_TAG_IPSRCRT, NULL);
1682 opt = m_tag_data(mtag);
1684 if (opt->ip_nhops == 0)
1686 m = m_get(MB_DONTWAIT, MT_HEADER);
1690 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt))
1692 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1693 m->m_len = opt->ip_nhops * sizeof(struct in_addr) +
1694 sizeof(struct in_addr) + OPTSIZ;
1697 kprintf("ip_srcroute: nhops %d mlen %d",
1698 opt->ip_nhops, m->m_len);
1703 * First save first hop for return route
1705 p = &opt->ip_srcrt.route[opt->ip_nhops - 1];
1706 *(mtod(m, struct in_addr *)) = *p--;
1709 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1713 * Copy option fields and padding (nop) to mbuf.
1715 opt->ip_srcrt.nop = IPOPT_NOP;
1716 opt->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1717 memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &opt->ip_srcrt.nop,
1719 q = (struct in_addr *)(mtod(m, caddr_t) +
1720 sizeof(struct in_addr) + OPTSIZ);
1723 * Record return path as an IP source route,
1724 * reversing the path (pointers are now aligned).
1726 while (p >= opt->ip_srcrt.route) {
1729 kprintf(" %x", ntohl(q->s_addr));
1734 * Last hop goes to final destination.
1736 *q = opt->ip_srcrt.dst;
1737 m_tag_delete(m0, mtag);
1740 kprintf(" %x\n", ntohl(q->s_addr));
1746 * Strip out IP options.
1749 ip_stripoptions(struct mbuf *m)
1752 struct ip *ip = mtod(m, struct ip *);
1756 optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1757 opts = (caddr_t)(ip + 1);
1758 datalen = m->m_len - (sizeof(struct ip) + optlen);
1759 bcopy(opts + optlen, opts, datalen);
1761 if (m->m_flags & M_PKTHDR)
1762 m->m_pkthdr.len -= optlen;
1763 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1766 u_char inetctlerrmap[PRC_NCMDS] = {
1768 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1769 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1770 EMSGSIZE, EHOSTUNREACH, 0, 0,
1772 ENOPROTOOPT, ECONNREFUSED
1776 * Forward a packet. If some error occurs return the sender
1777 * an icmp packet. Note we can't always generate a meaningful
1778 * icmp message because icmp doesn't have a large enough repertoire
1779 * of codes and types.
1781 * If not forwarding, just drop the packet. This could be confusing
1782 * if ipforwarding was zero but some routing protocol was advancing
1783 * us as a gateway to somewhere. However, we must let the routing
1784 * protocol deal with that.
1786 * The using_srcrt parameter indicates whether the packet is being forwarded
1787 * via a source route.
1790 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop)
1792 struct ip *ip = mtod(m, struct ip *);
1793 struct sockaddr_in *ipforward_rtaddr;
1795 int error, type = 0, code = 0, destmtu = 0;
1798 struct in_addr pkt_dst;
1799 struct route *cache_rt = &ipforward_rt[mycpuid];
1803 * Cache the destination address of the packet; this may be
1804 * changed by use of 'ipfw fwd'.
1806 pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst;
1810 kprintf("forward: src %x dst %x ttl %x\n",
1811 ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl);
1814 if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) {
1815 ipstat.ips_cantforward++;
1819 if (!ipstealth && ip->ip_ttl <= IPTTLDEC) {
1820 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1824 ipforward_rtaddr = (struct sockaddr_in *) &cache_rt->ro_dst;
1825 if (cache_rt->ro_rt == NULL ||
1826 ipforward_rtaddr->sin_addr.s_addr != pkt_dst.s_addr) {
1827 if (cache_rt->ro_rt != NULL) {
1828 RTFREE(cache_rt->ro_rt);
1829 cache_rt->ro_rt = NULL;
1831 ipforward_rtaddr->sin_family = AF_INET;
1832 ipforward_rtaddr->sin_len = sizeof(struct sockaddr_in);
1833 ipforward_rtaddr->sin_addr = pkt_dst;
1834 rtalloc_ign(cache_rt, RTF_PRCLONING);
1835 if (cache_rt->ro_rt == NULL) {
1836 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1840 rt = cache_rt->ro_rt;
1843 * Save the IP header and at most 8 bytes of the payload,
1844 * in case we need to generate an ICMP message to the src.
1846 * XXX this can be optimized a lot by saving the data in a local
1847 * buffer on the stack (72 bytes at most), and only allocating the
1848 * mbuf if really necessary. The vast majority of the packets
1849 * are forwarded without having to send an ICMP back (either
1850 * because unnecessary, or because rate limited), so we are
1851 * really we are wasting a lot of work here.
1853 * We don't use m_copy() because it might return a reference
1854 * to a shared cluster. Both this function and ip_output()
1855 * assume exclusive access to the IP header in `m', so any
1856 * data in a cluster may change before we reach icmp_error().
1858 MGETHDR(mcopy, MB_DONTWAIT, m->m_type);
1859 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, MB_DONTWAIT)) {
1861 * It's probably ok if the pkthdr dup fails (because
1862 * the deep copy of the tag chain failed), but for now
1863 * be conservative and just discard the copy since
1864 * code below may some day want the tags.
1869 if (mcopy != NULL) {
1870 mcopy->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8,
1872 mcopy->m_pkthdr.len = mcopy->m_len;
1873 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1877 ip->ip_ttl -= IPTTLDEC;
1880 * If forwarding packet using same interface that it came in on,
1881 * perhaps should send a redirect to sender to shortcut a hop.
1882 * Only send redirect if source is sending directly to us,
1883 * and if packet was not source routed (or has any options).
1884 * Also, don't send redirect if forwarding using a default route
1885 * or a route modified by a redirect.
1887 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1888 !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) &&
1889 satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY &&
1890 ipsendredirects && !using_srcrt && next_hop == NULL) {
1891 u_long src = ntohl(ip->ip_src.s_addr);
1892 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa;
1894 if (rt_ifa != NULL &&
1895 (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) {
1896 if (rt->rt_flags & RTF_GATEWAY)
1897 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1899 dest = pkt_dst.s_addr;
1901 * Router requirements says to only send
1904 type = ICMP_REDIRECT;
1905 code = ICMP_REDIRECT_HOST;
1908 kprintf("redirect (%d) to %x\n", code, dest);
1913 error = ip_output(m, NULL, cache_rt, IP_FORWARDING, NULL, NULL);
1915 ipstat.ips_forward++;
1918 ipflow_create(cache_rt, mcopy);
1921 return; /* most common case */
1923 ipstat.ips_redirectsent++;
1926 ipstat.ips_cantforward++;
1933 * Send ICMP message.
1938 case 0: /* forwarded, but need redirect */
1939 /* type, code set above */
1942 case ENETUNREACH: /* shouldn't happen, checked above */
1947 type = ICMP_UNREACH;
1948 code = ICMP_UNREACH_HOST;
1952 type = ICMP_UNREACH;
1953 code = ICMP_UNREACH_NEEDFRAG;
1956 * If the packet is routed over IPsec tunnel, tell the
1957 * originator the tunnel MTU.
1958 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1961 if (cache_rt->ro_rt != NULL) {
1962 struct secpolicy *sp = NULL;
1967 sp = ipsec4_getpolicybyaddr(mcopy,
1973 destmtu = cache_rt->ro_rt->rt_ifp->if_mtu;
1975 /* count IPsec header size */
1976 ipsechdr = ipsec4_hdrsiz(mcopy,
1981 * find the correct route for outer IPv4
1982 * header, compute tunnel MTU.
1985 if (sp->req != NULL && sp->req->sav != NULL &&
1986 sp->req->sav->sah != NULL) {
1987 ro = &sp->req->sav->sah->sa_route;
1988 if (ro->ro_rt != NULL &&
1989 ro->ro_rt->rt_ifp != NULL) {
1991 ro->ro_rt->rt_ifp->if_mtu;
1992 destmtu -= ipsechdr;
2001 * If the packet is routed over IPsec tunnel, tell the
2002 * originator the tunnel MTU.
2003 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2006 if (cache_rt->ro_rt != NULL) {
2007 struct secpolicy *sp = NULL;
2012 sp = ipsec_getpolicybyaddr(mcopy,
2018 destmtu = cache_rt->ro_rt->rt_ifp->if_mtu;
2020 /* count IPsec header size */
2021 ipsechdr = ipsec4_hdrsiz(mcopy,
2026 * find the correct route for outer IPv4
2027 * header, compute tunnel MTU.
2030 if (sp->req != NULL &&
2031 sp->req->sav != NULL &&
2032 sp->req->sav->sah != NULL) {
2033 ro = &sp->req->sav->sah->sa_route;
2034 if (ro->ro_rt != NULL &&
2035 ro->ro_rt->rt_ifp != NULL) {
2037 ro->ro_rt->rt_ifp->if_mtu;
2038 destmtu -= ipsechdr;
2045 #else /* !IPSEC && !FAST_IPSEC */
2046 if (cache_rt->ro_rt != NULL)
2047 destmtu = cache_rt->ro_rt->rt_ifp->if_mtu;
2049 ipstat.ips_cantfrag++;
2054 * A router should not generate ICMP_SOURCEQUENCH as
2055 * required in RFC1812 Requirements for IP Version 4 Routers.
2056 * Source quench could be a big problem under DoS attacks,
2057 * or if the underlying interface is rate-limited.
2058 * Those who need source quench packets may re-enable them
2059 * via the net.inet.ip.sendsourcequench sysctl.
2061 if (!ip_sendsourcequench) {
2065 type = ICMP_SOURCEQUENCH;
2070 case EACCES: /* ipfw denied packet */
2074 icmp_error(mcopy, type, code, dest, destmtu);
2078 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
2081 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
2085 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
2086 SCM_TIMESTAMP, SOL_SOCKET);
2088 mp = &(*mp)->m_next;
2090 if (inp->inp_flags & INP_RECVDSTADDR) {
2091 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
2092 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2094 mp = &(*mp)->m_next;
2096 if (inp->inp_flags & INP_RECVTTL) {
2097 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
2098 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
2100 mp = &(*mp)->m_next;
2104 * Moving these out of udp_input() made them even more broken
2105 * than they already were.
2107 /* options were tossed already */
2108 if (inp->inp_flags & INP_RECVOPTS) {
2109 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
2110 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
2112 mp = &(*mp)->m_next;
2114 /* ip_srcroute doesn't do what we want here, need to fix */
2115 if (inp->inp_flags & INP_RECVRETOPTS) {
2116 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
2117 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
2119 mp = &(*mp)->m_next;
2122 if (inp->inp_flags & INP_RECVIF) {
2125 struct sockaddr_dl sdl;
2128 struct sockaddr_dl *sdp;
2129 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
2131 if (((ifp = m->m_pkthdr.rcvif)) &&
2132 ((ifp->if_index != 0) && (ifp->if_index <= if_index))) {
2133 sdp = IF_LLSOCKADDR(ifp);
2135 * Change our mind and don't try copy.
2137 if ((sdp->sdl_family != AF_LINK) ||
2138 (sdp->sdl_len > sizeof(sdlbuf))) {
2141 bcopy(sdp, sdl2, sdp->sdl_len);
2145 offsetof(struct sockaddr_dl, sdl_data[0]);
2146 sdl2->sdl_family = AF_LINK;
2147 sdl2->sdl_index = 0;
2148 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2150 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2151 IP_RECVIF, IPPROTO_IP);
2153 mp = &(*mp)->m_next;
2158 * XXX these routines are called from the upper part of the kernel.
2160 * They could also be moved to ip_mroute.c, since all the RSVP
2161 * handling is done there already.
2164 ip_rsvp_init(struct socket *so)
2166 if (so->so_type != SOCK_RAW ||
2167 so->so_proto->pr_protocol != IPPROTO_RSVP)
2170 if (ip_rsvpd != NULL)
2175 * This may seem silly, but we need to be sure we don't over-increment
2176 * the RSVP counter, in case something slips up.
2191 * This may seem silly, but we need to be sure we don't over-decrement
2192 * the RSVP counter, in case something slips up.
2202 rsvp_input(struct mbuf *m, ...) /* XXX must fixup manually */
2208 off = __va_arg(ap, int);
2209 proto = __va_arg(ap, int);
2212 if (rsvp_input_p) { /* call the real one if loaded */
2213 rsvp_input_p(m, off, proto);
2217 /* Can still get packets with rsvp_on = 0 if there is a local member
2218 * of the group to which the RSVP packet is addressed. But in this
2219 * case we want to throw the packet away.
2227 if (ip_rsvpd != NULL) {
2228 rip_input(m, off, proto);
2231 /* Drop the packet */