2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
5 * This code is derived from software contributed to The DragonFly Project
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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12 * notice, this list of conditions and the following disclaimer.
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15 * documentation and/or other materials provided with the distribution.
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17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
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21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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39 * modification, are permitted provided that the following conditions
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63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
67 * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.52 2003/03/07 07:01:28 silby Exp $
72 #include "opt_bootp.h"
75 #include "opt_ipdivert.h"
76 #include "opt_ipstealth.h"
77 #include "opt_ipsec.h"
79 #include <sys/param.h>
80 #include <sys/systm.h>
82 #include <sys/malloc.h>
83 #include <sys/mpipe.h>
84 #include <sys/domain.h>
85 #include <sys/protosw.h>
86 #include <sys/socket.h>
88 #include <sys/globaldata.h>
89 #include <sys/thread.h>
90 #include <sys/kernel.h>
91 #include <sys/syslog.h>
92 #include <sys/sysctl.h>
93 #include <sys/in_cksum.h>
96 #include <sys/mplock2.h>
98 #include <machine/stdarg.h>
101 #include <net/if_types.h>
102 #include <net/if_var.h>
103 #include <net/if_dl.h>
104 #include <net/pfil.h>
105 #include <net/route.h>
106 #include <net/netisr.h>
108 #include <netinet/in.h>
109 #include <netinet/in_systm.h>
110 #include <netinet/in_var.h>
111 #include <netinet/ip.h>
112 #include <netinet/in_pcb.h>
113 #include <netinet/ip_var.h>
114 #include <netinet/ip_icmp.h>
115 #include <netinet/ip_divert.h>
116 #include <netinet/ip_flow.h>
118 #include <sys/thread2.h>
119 #include <sys/msgport2.h>
120 #include <net/netmsg2.h>
122 #include <sys/socketvar.h>
124 #include <net/ipfw/ip_fw.h>
125 #include <net/dummynet/ip_dummynet.h>
128 #include <netinet6/ipsec.h>
129 #include <netproto/key/key.h>
133 #include <netproto/ipsec/ipsec.h>
134 #include <netproto/ipsec/key.h>
138 static int ip_rsvp_on;
139 struct socket *ip_rsvpd;
141 int ipforwarding = 0;
142 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
143 &ipforwarding, 0, "Enable IP forwarding between interfaces");
145 static int ipsendredirects = 1; /* XXX */
146 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
147 &ipsendredirects, 0, "Enable sending IP redirects");
149 int ip_defttl = IPDEFTTL;
150 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
151 &ip_defttl, 0, "Maximum TTL on IP packets");
153 static int ip_dosourceroute = 0;
154 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
155 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
157 static int ip_acceptsourceroute = 0;
158 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
159 CTLFLAG_RW, &ip_acceptsourceroute, 0,
160 "Enable accepting source routed IP packets");
162 static int ip_keepfaith = 0;
163 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
165 "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
167 static int nipq = 0; /* total # of reass queues */
169 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
171 "Maximum number of IPv4 fragment reassembly queue entries");
173 static int maxfragsperpacket;
174 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
175 &maxfragsperpacket, 0,
176 "Maximum number of IPv4 fragments allowed per packet");
178 static int ip_sendsourcequench = 0;
179 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
180 &ip_sendsourcequench, 0,
181 "Enable the transmission of source quench packets");
183 int ip_do_randomid = 1;
184 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
186 "Assign random ip_id values");
188 * XXX - Setting ip_checkinterface mostly implements the receive side of
189 * the Strong ES model described in RFC 1122, but since the routing table
190 * and transmit implementation do not implement the Strong ES model,
191 * setting this to 1 results in an odd hybrid.
193 * XXX - ip_checkinterface currently must be disabled if you use ipnat
194 * to translate the destination address to another local interface.
196 * XXX - ip_checkinterface must be disabled if you add IP aliases
197 * to the loopback interface instead of the interface where the
198 * packets for those addresses are received.
200 static int ip_checkinterface = 0;
201 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
202 &ip_checkinterface, 0, "Verify packet arrives on correct interface");
204 static int ip_dispatch_fast = 0;
205 static int ip_dispatch_slow = 0;
206 static int ip_dispatch_recheck = 0;
207 static int ip_dispatch_software = 0;
208 SYSCTL_INT(_net_inet_ip, OID_AUTO, dispatch_fast_count, CTLFLAG_RD,
209 &ip_dispatch_fast, 0,
210 "Number of IP dispatches handled on current CPU");
211 SYSCTL_INT(_net_inet_ip, OID_AUTO, dispatch_slow_count, CTLFLAG_RD,
212 &ip_dispatch_slow, 0,
213 "Number of IP dispatches messaged to another CPU");
214 SYSCTL_INT(_net_inet_ip, OID_AUTO, dispatch_software_count, CTLFLAG_RD,
215 &ip_dispatch_software, 0, "");
216 SYSCTL_INT(_net_inet_ip, OID_AUTO, dispatch_recheck_count, CTLFLAG_RD,
217 &ip_dispatch_recheck, 0, "");
219 static struct lwkt_token ipq_token = LWKT_TOKEN_INITIALIZER(ipq_token);
222 static int ipprintfs = 0;
225 extern struct domain inetdomain;
226 extern struct protosw inetsw[];
227 u_char ip_protox[IPPROTO_MAX];
228 struct in_ifaddrhead in_ifaddrheads[MAXCPU]; /* first inet address */
229 struct in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU];
230 /* inet addr hash table */
231 u_long in_ifaddrhmask; /* mask for hash table */
233 struct ip_stats ipstats_percpu[MAXCPU];
236 sysctl_ipstats(SYSCTL_HANDLER_ARGS)
240 for (cpu = 0; cpu < ncpus; ++cpu) {
241 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu],
242 sizeof(struct ip_stats))))
244 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu],
245 sizeof(struct ip_stats))))
251 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
252 0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics");
254 SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
255 &ipstat, ip_stats, "IP statistics");
258 /* Packet reassembly stuff */
259 #define IPREASS_NHASH_LOG2 6
260 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
261 #define IPREASS_HMASK (IPREASS_NHASH - 1)
262 #define IPREASS_HASH(x,y) \
263 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
265 static TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH];
268 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
269 &ip_mtu, 0, "Default MTU");
273 static int ipstealth = 0;
274 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, "");
276 static const int ipstealth = 0;
279 struct mbuf *(*ip_divert_p)(struct mbuf *, int, int);
281 struct pfil_head inet_pfil_hook;
284 * struct ip_srcrt_opt is used to store packet state while it travels
287 * XXX Note that the code even makes assumptions on the size and
288 * alignment of fields inside struct ip_srcrt so e.g. adding some
289 * fields will break the code. This needs to be fixed.
291 * We need to save the IP options in case a protocol wants to respond
292 * to an incoming packet over the same route if the packet got here
293 * using IP source routing. This allows connection establishment and
294 * maintenance when the remote end is on a network that is not known
298 struct in_addr dst; /* final destination */
299 char nop; /* one NOP to align */
300 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
301 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
304 struct ip_srcrt_opt {
306 struct ip_srcrt ip_srcrt;
309 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management");
310 static struct malloc_pipe ipq_mpipe;
312 static void save_rte(struct mbuf *, u_char *, struct in_addr);
313 static int ip_dooptions(struct mbuf *m, int, struct sockaddr_in *);
314 static void ip_freef(struct ipqhead *, struct ipq *);
315 static void ip_input_handler(netmsg_t);
318 * IP initialization: fill in IP protocol switch table.
319 * All protocols not implemented in kernel go to raw IP protocol handler.
331 * Make sure we can handle a reasonable number of fragments but
332 * cap it at 4000 (XXX).
334 mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq),
335 IFQ_MAXLEN, 4000, 0, NULL, NULL, NULL);
336 for (i = 0; i < ncpus; ++i) {
337 TAILQ_INIT(&in_ifaddrheads[i]);
338 in_ifaddrhashtbls[i] =
339 hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
341 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
344 for (i = 0; i < IPPROTO_MAX; i++)
345 ip_protox[i] = pr - inetsw;
346 for (pr = inetdomain.dom_protosw;
347 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
348 if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol) {
349 if (pr->pr_protocol != IPPROTO_RAW)
350 ip_protox[pr->pr_protocol] = pr - inetsw;
354 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
355 inet_pfil_hook.ph_af = AF_INET;
356 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) {
357 kprintf("%s: WARNING: unable to register pfil hook, "
358 "error %d\n", __func__, i);
361 for (i = 0; i < IPREASS_NHASH; i++)
364 maxnipq = nmbclusters / 32;
365 maxfragsperpacket = 16;
367 ip_id = time_second & 0xffff;
370 * Initialize IP statistics counters for each CPU.
374 for (cpu = 0; cpu < ncpus; ++cpu) {
375 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats));
378 bzero(&ipstat, sizeof(struct ip_stats));
381 netisr_register(NETISR_IP, ip_input_handler, ip_cpufn_in);
382 netisr_register_hashcheck(NETISR_IP, ip_hashcheck);
385 /* Do transport protocol processing. */
387 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip)
389 const struct protosw *pr = &inetsw[ip_protox[ip->ip_p]];
392 * Switch out to protocol's input routine.
395 pr->pr_input(&m, &hlen, ip->ip_p);
400 transport_processing_handler(netmsg_t msg)
402 struct netmsg_packet *pmsg = &msg->packet;
406 ip = mtod(pmsg->nm_packet, struct ip *);
407 hlen = pmsg->base.lmsg.u.ms_result;
409 transport_processing_oncpu(pmsg->nm_packet, hlen, ip);
410 /* msg was embedded in the mbuf, do not reply! */
414 ip_input_handler(netmsg_t msg)
416 ip_input(msg->packet.nm_packet);
417 /* msg was embedded in the mbuf, do not reply! */
421 * IP input routine. Checksum and byte swap header. If fragmented
422 * try to reassemble. Process options. Pass to next level.
425 ip_input(struct mbuf *m)
428 struct in_ifaddr *ia = NULL;
429 struct in_ifaddr_container *iac;
432 struct in_addr pkt_dst;
433 boolean_t using_srcrt = FALSE; /* forward (by PFIL_HOOKS) */
434 struct in_addr odst; /* original dst address(NAT) */
436 struct sockaddr_in *next_hop = NULL;
439 struct tdb_ident *tdbi;
440 struct secpolicy *sp;
447 * This routine is called from numerous places which may not have
448 * characterized the packet.
450 if ((m->m_flags & M_HASH) == 0) {
451 ++ip_dispatch_software;
452 ip_cpufn(&m, 0, IP_MPORT_IN);
455 KKASSERT(m->m_flags & M_HASH);
457 ip = mtod(m, struct ip *);
460 * Pull out certain tags
462 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
464 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
465 KKASSERT(mtag != NULL);
466 next_hop = m_tag_data(mtag);
469 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
470 /* dummynet already filtered us */
471 ip = mtod(m, struct ip *);
472 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
478 /* length checks already done in ip_cpufn() */
479 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf"));
481 if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
482 ipstat.ips_badvers++;
486 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
487 /* length checks already done in ip_cpufn() */
488 KASSERT(hlen >= sizeof(struct ip), ("IP header len too small"));
489 KASSERT(m->m_len >= hlen, ("complete IP header not in one mbuf"));
491 /* 127/8 must not appear on wire - RFC1122 */
492 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
493 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
494 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) {
495 ipstat.ips_badaddr++;
500 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
501 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
503 if (hlen == sizeof(struct ip))
504 sum = in_cksum_hdr(ip);
506 sum = in_cksum(m, hlen);
514 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
515 /* packet is dropped by traffic conditioner */
520 * Convert fields to host representation.
522 ip->ip_len = ntohs(ip->ip_len);
523 ip->ip_off = ntohs(ip->ip_off);
525 /* length checks already done in ip_cpufn() */
526 KASSERT(ip->ip_len >= hlen, ("total length less then header length"));
527 KASSERT(m->m_pkthdr.len >= ip->ip_len, ("mbuf too short"));
530 * Trim mbufs if longer than the IP header would have us expect.
532 if (m->m_pkthdr.len > ip->ip_len) {
533 if (m->m_len == m->m_pkthdr.len) {
534 m->m_len = ip->ip_len;
535 m->m_pkthdr.len = ip->ip_len;
537 m_adj(m, ip->ip_len - m->m_pkthdr.len);
540 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
542 * Bypass packet filtering for packets from a tunnel (gif).
544 if (ipsec_gethist(m, NULL))
550 * Right now when no processing on packet has done
551 * and it is still fresh out of network we do our black
553 * - Firewall: deny/allow/divert
554 * - Xlate: translate packet's addr/port (NAT).
555 * - Pipe: pass pkt through dummynet.
556 * - Wrap: fake packet's addr/port <unimpl.>
557 * - Encapsulate: put it in another IP and send out. <unimp.>
562 * If we've been forwarded from the output side, then
563 * skip the firewall a second time
565 if (next_hop != NULL)
569 if (!pfil_has_hooks(&inet_pfil_hook)) {
570 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
572 * Strip dummynet tags from stranded packets
574 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
575 KKASSERT(mtag != NULL);
576 m_tag_delete(m, mtag);
577 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
583 * Run through list of hooks for input packets.
585 * NOTE! If the packet is rewritten pf/ipfw/whoever must
589 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN))
591 if (m == NULL) /* consumed by filter */
593 ip = mtod(m, struct ip *);
594 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
595 using_srcrt = (odst.s_addr != ip->ip_dst.s_addr);
597 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
598 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
599 KKASSERT(mtag != NULL);
600 next_hop = m_tag_data(mtag);
602 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
606 if (m->m_pkthdr.fw_flags & FW_MBUF_REDISPATCH) {
607 m->m_pkthdr.fw_flags &= ~FW_MBUF_REDISPATCH;
611 * Process options and, if not destined for us,
612 * ship it on. ip_dooptions returns 1 when an
613 * error was detected (causing an icmp message
614 * to be sent and the original packet to be freed).
616 if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, next_hop))
619 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
620 * matter if it is destined to another node, or whether it is
621 * a multicast one, RSVP wants it! and prevents it from being forwarded
622 * anywhere else. Also checks if the rsvp daemon is running before
623 * grabbing the packet.
625 if (rsvp_on && ip->ip_p == IPPROTO_RSVP)
629 * Check our list of addresses, to see if the packet is for us.
630 * If we don't have any addresses, assume any unicast packet
631 * we receive might be for us (and let the upper layers deal
634 if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) &&
635 !(m->m_flags & (M_MCAST | M_BCAST)))
639 * Cache the destination address of the packet; this may be
640 * changed by use of 'ipfw fwd'.
642 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
645 * Enable a consistency check between the destination address
646 * and the arrival interface for a unicast packet (the RFC 1122
647 * strong ES model) if IP forwarding is disabled and the packet
648 * is not locally generated and the packet is not subject to
651 * XXX - Checking also should be disabled if the destination
652 * address is ipnat'ed to a different interface.
654 * XXX - Checking is incompatible with IP aliases added
655 * to the loopback interface instead of the interface where
656 * the packets are received.
658 checkif = ip_checkinterface &&
660 m->m_pkthdr.rcvif != NULL &&
661 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) &&
665 * Check for exact addresses in the hash bucket.
667 LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
671 * If the address matches, verify that the packet
672 * arrived via the correct interface if checking is
675 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
676 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
682 * Check for broadcast addresses.
684 * Only accept broadcast packets that arrive via the matching
685 * interface. Reception of forwarded directed broadcasts would
686 * be handled via ip_forward() and ether_output() with the loopback
687 * into the stack for SIMPLEX interfaces handled by ether_output().
689 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
690 struct ifaddr_container *ifac;
692 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid],
694 struct ifaddr *ifa = ifac->ifa;
696 if (ifa->ifa_addr == NULL) /* shutdown/startup race */
698 if (ifa->ifa_addr->sa_family != AF_INET)
701 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
704 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
707 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
712 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
713 struct in_multi *inm;
715 /* XXX Multicast is not MPSAFE yet */
718 if (ip_mrouter != NULL) {
720 * If we are acting as a multicast router, all
721 * incoming multicast packets are passed to the
722 * kernel-level multicast forwarding function.
723 * The packet is returned (relatively) intact; if
724 * ip_mforward() returns a non-zero value, the packet
725 * must be discarded, else it may be accepted below.
727 if (ip_mforward != NULL &&
728 ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) {
730 ipstat.ips_cantforward++;
736 * The process-level routing daemon needs to receive
737 * all multicast IGMP packets, whether or not this
738 * host belongs to their destination groups.
740 if (ip->ip_p == IPPROTO_IGMP) {
744 ipstat.ips_forward++;
747 * See if we belong to the destination multicast group on the
750 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
753 ipstat.ips_notmember++;
761 if (ip->ip_dst.s_addr == INADDR_BROADCAST)
763 if (ip->ip_dst.s_addr == INADDR_ANY)
767 * FAITH(Firewall Aided Internet Translator)
769 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
771 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
779 * Not for us; forward if possible and desirable.
782 ipstat.ips_cantforward++;
787 * Enforce inbound IPsec SPD.
789 if (ipsec4_in_reject(m, NULL)) {
790 ipsecstat.in_polvio++;
795 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
798 tdbi = (struct tdb_ident *)m_tag_data(mtag);
799 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
801 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
802 IP_FORWARDING, &error);
804 if (sp == NULL) { /* NB: can happen if error */
806 /*XXX error stat???*/
807 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
812 * Check security policy against packet attributes.
814 error = ipsec_in_reject(sp, m);
818 ipstat.ips_cantforward++;
822 ip_forward(m, using_srcrt, next_hop);
829 * IPSTEALTH: Process non-routing options only
830 * if the packet is destined for us.
833 hlen > sizeof(struct ip) &&
834 ip_dooptions(m, 1, next_hop))
837 /* Count the packet in the ip address stats */
839 ia->ia_ifa.if_ipackets++;
840 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
844 * If offset or IP_MF are set, must reassemble.
845 * Otherwise, nothing need be done.
846 * (We could look in the reassembly queue to see
847 * if the packet was previously fragmented,
848 * but it's not worth the time; just let them time out.)
850 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
852 * Attempt reassembly; if it succeeds, proceed. ip_reass()
853 * will return a different mbuf.
855 * NOTE: ip_reass() returns m with M_HASH cleared to force
856 * us to recharacterize the packet.
861 ip = mtod(m, struct ip *);
863 /* Get the header length of the reassembled packet */
864 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
871 * enforce IPsec policy checking if we are seeing last header.
872 * note that we do not visit this with protocols with pcb layer
873 * code - like udp/tcp/raw ip.
875 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) &&
876 ipsec4_in_reject(m, NULL)) {
877 ipsecstat.in_polvio++;
883 * enforce IPsec policy checking if we are seeing last header.
884 * note that we do not visit this with protocols with pcb layer
885 * code - like udp/tcp/raw ip.
887 if (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) {
889 * Check if the packet has already had IPsec processing
890 * done. If so, then just pass it along. This tag gets
891 * set during AH, ESP, etc. input handling, before the
892 * packet is returned to the ip input queue for delivery.
894 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
897 tdbi = (struct tdb_ident *)m_tag_data(mtag);
898 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
900 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
901 IP_FORWARDING, &error);
905 * Check security policy against packet attributes.
907 error = ipsec_in_reject(sp, m);
910 /* XXX error stat??? */
912 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
919 #endif /* FAST_IPSEC */
922 * We must forward the packet to the correct protocol thread if
923 * we are not already in it.
925 * NOTE: ip_len is now in host form. ip_len is not adjusted
926 * further for protocol processing, instead we pass hlen
927 * to the protosw and let it deal with it.
929 ipstat.ips_delivered++;
931 if ((m->m_flags & M_HASH) == 0) {
932 ++ip_dispatch_recheck;
933 ip->ip_len = htons(ip->ip_len + hlen);
934 ip->ip_off = htons(ip->ip_off);
936 ip_cpufn(&m, 0, IP_MPORT_IN);
940 ip = mtod(m, struct ip *);
941 ip->ip_len = ntohs(ip->ip_len) - hlen;
942 ip->ip_off = ntohs(ip->ip_off);
943 KKASSERT(m->m_flags & M_HASH);
945 port = cpu_portfn(m->m_pkthdr.hash);
947 if (port != &curthread->td_msgport) {
948 struct netmsg_packet *pmsg;
952 pmsg = &m->m_hdr.mh_netmsg;
953 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport,
954 0, transport_processing_handler);
956 pmsg->base.lmsg.u.ms_result = hlen;
957 lwkt_sendmsg(port, &pmsg->base.lmsg);
960 transport_processing_oncpu(m, hlen, ip);
969 * Take incoming datagram fragment and try to reassemble it into
970 * whole datagram. If a chain for reassembly of this datagram already
971 * exists, then it is given as fp; otherwise have to make a chain.
974 ip_reass(struct mbuf *m)
976 struct ip *ip = mtod(m, struct ip *);
977 struct mbuf *p = NULL, *q, *nq;
979 struct ipq *fp = NULL;
980 struct ipqhead *head;
981 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
985 /* If maxnipq is 0, never accept fragments. */
987 ipstat.ips_fragments++;
988 ipstat.ips_fragdropped++;
993 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
995 * Look for queue of fragments of this datagram.
997 lwkt_gettoken(&ipq_token);
999 TAILQ_FOREACH(fp, head, ipq_list) {
1000 if (ip->ip_id == fp->ipq_id &&
1001 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
1002 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
1003 ip->ip_p == fp->ipq_p)
1010 * Enforce upper bound on number of fragmented packets
1011 * for which we attempt reassembly;
1012 * If maxnipq is -1, accept all fragments without limitation.
1014 if (nipq > maxnipq && maxnipq > 0) {
1016 * drop something from the tail of the current queue
1017 * before proceeding further
1019 struct ipq *q = TAILQ_LAST(head, ipqhead);
1022 * The current queue is empty,
1023 * so drop from one of the others.
1025 for (i = 0; i < IPREASS_NHASH; i++) {
1026 struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead);
1028 ipstat.ips_fragtimeout += r->ipq_nfrags;
1029 ip_freef(&ipq[i], r);
1034 ipstat.ips_fragtimeout += q->ipq_nfrags;
1040 * Adjust ip_len to not reflect header,
1041 * convert offset of this to bytes.
1044 if (ip->ip_off & IP_MF) {
1046 * Make sure that fragments have a data length
1047 * that's a non-zero multiple of 8 bytes.
1049 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1050 ipstat.ips_toosmall++; /* XXX */
1054 m->m_flags |= M_FRAG;
1056 m->m_flags &= ~M_FRAG;
1060 ipstat.ips_fragments++;
1061 m->m_pkthdr.header = ip;
1064 * If the hardware has not done csum over this fragment
1065 * then csum_data is not valid at all.
1067 if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID))
1068 == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) {
1069 m->m_pkthdr.csum_data = 0;
1070 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
1074 * Presence of header sizes in mbufs
1075 * would confuse code below.
1081 * If first fragment to arrive, create a reassembly queue.
1084 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL)
1086 TAILQ_INSERT_HEAD(head, fp, ipq_list);
1089 fp->ipq_ttl = IPFRAGTTL;
1090 fp->ipq_p = ip->ip_p;
1091 fp->ipq_id = ip->ip_id;
1092 fp->ipq_src = ip->ip_src;
1093 fp->ipq_dst = ip->ip_dst;
1095 m->m_nextpkt = NULL;
1101 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1104 * Find a segment which begins after this one does.
1106 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1107 if (GETIP(q)->ip_off > ip->ip_off)
1112 * If there is a preceding segment, it may provide some of
1113 * our data already. If so, drop the data from the incoming
1114 * segment. If it provides all of our data, drop us, otherwise
1115 * stick new segment in the proper place.
1117 * If some of the data is dropped from the the preceding
1118 * segment, then it's checksum is invalidated.
1121 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1123 if (i >= ip->ip_len)
1126 m->m_pkthdr.csum_flags = 0;
1130 m->m_nextpkt = p->m_nextpkt;
1133 m->m_nextpkt = fp->ipq_frags;
1138 * While we overlap succeeding segments trim them or,
1139 * if they are completely covered, dequeue them.
1141 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1143 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1144 if (i < GETIP(q)->ip_len) {
1145 GETIP(q)->ip_len -= i;
1146 GETIP(q)->ip_off += i;
1148 q->m_pkthdr.csum_flags = 0;
1153 ipstat.ips_fragdropped++;
1155 q->m_nextpkt = NULL;
1161 * Check for complete reassembly and perform frag per packet
1164 * Frag limiting is performed here so that the nth frag has
1165 * a chance to complete the packet before we drop the packet.
1166 * As a result, n+1 frags are actually allowed per packet, but
1167 * only n will ever be stored. (n = maxfragsperpacket.)
1171 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1172 if (GETIP(q)->ip_off != next) {
1173 if (fp->ipq_nfrags > maxfragsperpacket) {
1174 ipstat.ips_fragdropped += fp->ipq_nfrags;
1179 next += GETIP(q)->ip_len;
1181 /* Make sure the last packet didn't have the IP_MF flag */
1182 if (p->m_flags & M_FRAG) {
1183 if (fp->ipq_nfrags > maxfragsperpacket) {
1184 ipstat.ips_fragdropped += fp->ipq_nfrags;
1191 * Reassembly is complete. Make sure the packet is a sane size.
1195 if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
1196 ipstat.ips_toolong++;
1197 ipstat.ips_fragdropped += fp->ipq_nfrags;
1203 * Concatenate fragments.
1210 q->m_nextpkt = NULL;
1211 for (q = nq; q != NULL; q = nq) {
1213 q->m_nextpkt = NULL;
1214 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1215 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1220 * Clean up the 1's complement checksum. Carry over 16 bits must
1221 * be added back. This assumes no more then 65535 packet fragments
1222 * were reassembled. A second carry can also occur (but not a third).
1224 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) +
1225 (m->m_pkthdr.csum_data >> 16);
1226 if (m->m_pkthdr.csum_data > 0xFFFF)
1227 m->m_pkthdr.csum_data -= 0xFFFF;
1230 * Create header for new ip packet by
1231 * modifying header of first packet;
1232 * dequeue and discard fragment reassembly header.
1233 * Make header visible.
1236 ip->ip_src = fp->ipq_src;
1237 ip->ip_dst = fp->ipq_dst;
1238 TAILQ_REMOVE(head, fp, ipq_list);
1240 mpipe_free(&ipq_mpipe, fp);
1241 m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
1242 m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
1243 /* some debugging cruft by sklower, below, will go away soon */
1244 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1247 for (n = m; n; n = n->m_next)
1249 m->m_pkthdr.len = plen;
1253 * Reassembly complete, return the next protocol.
1255 * Be sure to clear M_HASH to force the packet
1256 * to be re-characterized.
1258 * Clear M_FRAG, we are no longer a fragment.
1260 m->m_flags &= ~(M_HASH | M_FRAG);
1262 ipstat.ips_reassembled++;
1263 lwkt_reltoken(&ipq_token);
1267 ipstat.ips_fragdropped++;
1272 lwkt_reltoken(&ipq_token);
1279 * Free a fragment reassembly header and all
1280 * associated datagrams.
1282 * Called with ipq_token held.
1285 ip_freef(struct ipqhead *fhp, struct ipq *fp)
1290 * Remove first to protect against blocking
1292 TAILQ_REMOVE(fhp, fp, ipq_list);
1295 * Clean out at our leisure
1297 while (fp->ipq_frags) {
1299 fp->ipq_frags = q->m_nextpkt;
1300 q->m_nextpkt = NULL;
1303 mpipe_free(&ipq_mpipe, fp);
1308 * IP timer processing;
1309 * if a timer expires on a reassembly
1310 * queue, discard it.
1315 struct ipq *fp, *fp_temp;
1316 struct ipqhead *head;
1319 lwkt_gettoken(&ipq_token);
1320 for (i = 0; i < IPREASS_NHASH; i++) {
1322 TAILQ_FOREACH_MUTABLE(fp, head, ipq_list, fp_temp) {
1323 if (--fp->ipq_ttl == 0) {
1324 ipstat.ips_fragtimeout += fp->ipq_nfrags;
1330 * If we are over the maximum number of fragments
1331 * (due to the limit being lowered), drain off
1332 * enough to get down to the new limit.
1334 if (maxnipq >= 0 && nipq > maxnipq) {
1335 for (i = 0; i < IPREASS_NHASH; i++) {
1337 while (nipq > maxnipq && !TAILQ_EMPTY(head)) {
1338 ipstat.ips_fragdropped +=
1339 TAILQ_FIRST(head)->ipq_nfrags;
1340 ip_freef(head, TAILQ_FIRST(head));
1344 lwkt_reltoken(&ipq_token);
1349 * Drain off all datagram fragments.
1354 struct ipqhead *head;
1357 lwkt_gettoken(&ipq_token);
1358 for (i = 0; i < IPREASS_NHASH; i++) {
1360 while (!TAILQ_EMPTY(head)) {
1361 ipstat.ips_fragdropped += TAILQ_FIRST(head)->ipq_nfrags;
1362 ip_freef(head, TAILQ_FIRST(head));
1365 lwkt_reltoken(&ipq_token);
1370 * Do option processing on a datagram,
1371 * possibly discarding it if bad options are encountered,
1372 * or forwarding it if source-routed.
1373 * The pass argument is used when operating in the IPSTEALTH
1374 * mode to tell what options to process:
1375 * [LS]SRR (pass 0) or the others (pass 1).
1376 * The reason for as many as two passes is that when doing IPSTEALTH,
1377 * non-routing options should be processed only if the packet is for us.
1378 * Returns 1 if packet has been forwarded/freed,
1379 * 0 if the packet should be processed further.
1382 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
1384 struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET };
1385 struct ip *ip = mtod(m, struct ip *);
1387 struct in_ifaddr *ia;
1388 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB;
1389 boolean_t forward = FALSE;
1390 struct in_addr *sin, dst;
1394 cp = (u_char *)(ip + 1);
1395 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1396 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1397 opt = cp[IPOPT_OPTVAL];
1398 if (opt == IPOPT_EOL)
1400 if (opt == IPOPT_NOP)
1403 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1404 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1407 optlen = cp[IPOPT_OLEN];
1408 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1409 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1419 * Source routing with record.
1420 * Find interface with current destination address.
1421 * If none on this machine then drop if strictly routed,
1422 * or do nothing if loosely routed.
1423 * Record interface address and bring up next address
1424 * component. If strictly routed make sure next
1425 * address is on directly accessible net.
1429 if (ipstealth && pass > 0)
1431 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1432 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1435 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1436 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1439 ipaddr.sin_addr = ip->ip_dst;
1440 ia = (struct in_ifaddr *)
1441 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1443 if (opt == IPOPT_SSRR) {
1444 type = ICMP_UNREACH;
1445 code = ICMP_UNREACH_SRCFAIL;
1448 if (!ip_dosourceroute)
1449 goto nosourcerouting;
1451 * Loose routing, and not at next destination
1452 * yet; nothing to do except forward.
1456 off--; /* 0 origin */
1457 if (off > optlen - (int)sizeof(struct in_addr)) {
1459 * End of source route. Should be for us.
1461 if (!ip_acceptsourceroute)
1462 goto nosourcerouting;
1463 save_rte(m, cp, ip->ip_src);
1468 if (!ip_dosourceroute) {
1470 char buf[sizeof "aaa.bbb.ccc.ddd"];
1473 * Acting as a router, so generate ICMP
1476 strcpy(buf, inet_ntoa(ip->ip_dst));
1478 "attempted source route from %s to %s\n",
1479 inet_ntoa(ip->ip_src), buf);
1480 type = ICMP_UNREACH;
1481 code = ICMP_UNREACH_SRCFAIL;
1485 * Not acting as a router,
1489 ipstat.ips_cantforward++;
1496 * locate outgoing interface
1498 memcpy(&ipaddr.sin_addr, cp + off,
1499 sizeof ipaddr.sin_addr);
1501 if (opt == IPOPT_SSRR) {
1502 #define INA struct in_ifaddr *
1503 #define SA struct sockaddr *
1504 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr))
1506 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1508 ia = ip_rtaddr(ipaddr.sin_addr, NULL);
1511 type = ICMP_UNREACH;
1512 code = ICMP_UNREACH_SRCFAIL;
1515 ip->ip_dst = ipaddr.sin_addr;
1516 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1517 sizeof(struct in_addr));
1518 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1520 * Let ip_intr's mcast routing check handle mcast pkts
1522 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1526 if (ipstealth && pass == 0)
1528 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1529 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1532 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1533 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1537 * If no space remains, ignore.
1539 off--; /* 0 origin */
1540 if (off > optlen - (int)sizeof(struct in_addr))
1542 memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1543 sizeof ipaddr.sin_addr);
1545 * locate outgoing interface; if we're the destination,
1546 * use the incoming interface (should be same).
1548 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL &&
1549 (ia = ip_rtaddr(ipaddr.sin_addr, NULL)) == NULL) {
1550 type = ICMP_UNREACH;
1551 code = ICMP_UNREACH_HOST;
1554 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1555 sizeof(struct in_addr));
1556 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1560 if (ipstealth && pass == 0)
1562 code = cp - (u_char *)ip;
1563 if (optlen < 4 || optlen > 40) {
1564 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1567 if ((off = cp[IPOPT_OFFSET]) < 5) {
1568 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1571 if (off > optlen - (int)sizeof(int32_t)) {
1572 cp[IPOPT_OFFSET + 1] += (1 << 4);
1573 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1574 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1579 off--; /* 0 origin */
1580 sin = (struct in_addr *)(cp + off);
1581 switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1583 case IPOPT_TS_TSONLY:
1586 case IPOPT_TS_TSANDADDR:
1587 if (off + sizeof(n_time) +
1588 sizeof(struct in_addr) > optlen) {
1589 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1592 ipaddr.sin_addr = dst;
1593 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1597 memcpy(sin, &IA_SIN(ia)->sin_addr,
1598 sizeof(struct in_addr));
1599 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1600 off += sizeof(struct in_addr);
1603 case IPOPT_TS_PRESPEC:
1604 if (off + sizeof(n_time) +
1605 sizeof(struct in_addr) > optlen) {
1606 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1609 memcpy(&ipaddr.sin_addr, sin,
1610 sizeof(struct in_addr));
1611 if (ifa_ifwithaddr((SA)&ipaddr) == NULL)
1613 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1614 off += sizeof(struct in_addr);
1618 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1622 memcpy(cp + off, &ntime, sizeof(n_time));
1623 cp[IPOPT_OFFSET] += sizeof(n_time);
1626 if (forward && ipforwarding) {
1627 ip_forward(m, TRUE, next_hop);
1632 icmp_error(m, type, code, 0, 0);
1633 ipstat.ips_badoptions++;
1638 * Given address of next destination (final or next hop),
1639 * return internet address info of interface to be used to get there.
1642 ip_rtaddr(struct in_addr dst, struct route *ro0)
1644 struct route sro, *ro;
1645 struct sockaddr_in *sin;
1646 struct in_ifaddr *ia;
1651 bzero(&sro, sizeof(sro));
1655 sin = (struct sockaddr_in *)&ro->ro_dst;
1657 if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) {
1658 if (ro->ro_rt != NULL) {
1662 sin->sin_family = AF_INET;
1663 sin->sin_len = sizeof *sin;
1664 sin->sin_addr = dst;
1665 rtalloc_ign(ro, RTF_PRCLONING);
1668 if (ro->ro_rt == NULL)
1671 ia = ifatoia(ro->ro_rt->rt_ifa);
1679 * Save incoming source route for use in replies,
1680 * to be picked up later by ip_srcroute if the receiver is interested.
1683 save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1686 struct ip_srcrt_opt *opt;
1689 mtag = m_tag_get(PACKET_TAG_IPSRCRT, sizeof(*opt), MB_DONTWAIT);
1692 opt = m_tag_data(mtag);
1694 olen = option[IPOPT_OLEN];
1697 kprintf("save_rte: olen %d\n", olen);
1699 if (olen > sizeof(opt->ip_srcrt) - (1 + sizeof(dst))) {
1703 bcopy(option, opt->ip_srcrt.srcopt, olen);
1704 opt->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1705 opt->ip_srcrt.dst = dst;
1706 m_tag_prepend(m, mtag);
1710 * Retrieve incoming source route for use in replies,
1711 * in the same form used by setsockopt.
1712 * The first hop is placed before the options, will be removed later.
1715 ip_srcroute(struct mbuf *m0)
1717 struct in_addr *p, *q;
1720 struct ip_srcrt_opt *opt;
1725 mtag = m_tag_find(m0, PACKET_TAG_IPSRCRT, NULL);
1728 opt = m_tag_data(mtag);
1730 if (opt->ip_nhops == 0)
1732 m = m_get(MB_DONTWAIT, MT_HEADER);
1736 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt))
1738 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1739 m->m_len = opt->ip_nhops * sizeof(struct in_addr) +
1740 sizeof(struct in_addr) + OPTSIZ;
1743 kprintf("ip_srcroute: nhops %d mlen %d",
1744 opt->ip_nhops, m->m_len);
1749 * First save first hop for return route
1751 p = &opt->ip_srcrt.route[opt->ip_nhops - 1];
1752 *(mtod(m, struct in_addr *)) = *p--;
1755 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1759 * Copy option fields and padding (nop) to mbuf.
1761 opt->ip_srcrt.nop = IPOPT_NOP;
1762 opt->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1763 memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &opt->ip_srcrt.nop,
1765 q = (struct in_addr *)(mtod(m, caddr_t) +
1766 sizeof(struct in_addr) + OPTSIZ);
1769 * Record return path as an IP source route,
1770 * reversing the path (pointers are now aligned).
1772 while (p >= opt->ip_srcrt.route) {
1775 kprintf(" %x", ntohl(q->s_addr));
1780 * Last hop goes to final destination.
1782 *q = opt->ip_srcrt.dst;
1783 m_tag_delete(m0, mtag);
1786 kprintf(" %x\n", ntohl(q->s_addr));
1792 * Strip out IP options.
1795 ip_stripoptions(struct mbuf *m)
1798 struct ip *ip = mtod(m, struct ip *);
1802 optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1803 opts = (caddr_t)(ip + 1);
1804 datalen = m->m_len - (sizeof(struct ip) + optlen);
1805 bcopy(opts + optlen, opts, datalen);
1807 if (m->m_flags & M_PKTHDR)
1808 m->m_pkthdr.len -= optlen;
1809 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1812 u_char inetctlerrmap[PRC_NCMDS] = {
1814 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1815 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1816 EMSGSIZE, EHOSTUNREACH, 0, 0,
1818 ENOPROTOOPT, ECONNREFUSED
1822 * Forward a packet. If some error occurs return the sender
1823 * an icmp packet. Note we can't always generate a meaningful
1824 * icmp message because icmp doesn't have a large enough repertoire
1825 * of codes and types.
1827 * If not forwarding, just drop the packet. This could be confusing
1828 * if ipforwarding was zero but some routing protocol was advancing
1829 * us as a gateway to somewhere. However, we must let the routing
1830 * protocol deal with that.
1832 * The using_srcrt parameter indicates whether the packet is being forwarded
1833 * via a source route.
1836 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop)
1838 struct ip *ip = mtod(m, struct ip *);
1840 struct route fwd_ro;
1841 int error, type = 0, code = 0, destmtu = 0;
1844 struct in_addr pkt_dst;
1848 * Cache the destination address of the packet; this may be
1849 * changed by use of 'ipfw fwd'.
1851 pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst;
1855 kprintf("forward: src %x dst %x ttl %x\n",
1856 ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl);
1859 if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) {
1860 ipstat.ips_cantforward++;
1864 if (!ipstealth && ip->ip_ttl <= IPTTLDEC) {
1865 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1869 bzero(&fwd_ro, sizeof(fwd_ro));
1870 ip_rtaddr(pkt_dst, &fwd_ro);
1871 if (fwd_ro.ro_rt == NULL) {
1872 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1878 * Save the IP header and at most 8 bytes of the payload,
1879 * in case we need to generate an ICMP message to the src.
1881 * XXX this can be optimized a lot by saving the data in a local
1882 * buffer on the stack (72 bytes at most), and only allocating the
1883 * mbuf if really necessary. The vast majority of the packets
1884 * are forwarded without having to send an ICMP back (either
1885 * because unnecessary, or because rate limited), so we are
1886 * really we are wasting a lot of work here.
1888 * We don't use m_copy() because it might return a reference
1889 * to a shared cluster. Both this function and ip_output()
1890 * assume exclusive access to the IP header in `m', so any
1891 * data in a cluster may change before we reach icmp_error().
1893 MGETHDR(mcopy, MB_DONTWAIT, m->m_type);
1894 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, MB_DONTWAIT)) {
1896 * It's probably ok if the pkthdr dup fails (because
1897 * the deep copy of the tag chain failed), but for now
1898 * be conservative and just discard the copy since
1899 * code below may some day want the tags.
1904 if (mcopy != NULL) {
1905 mcopy->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8,
1907 mcopy->m_pkthdr.len = mcopy->m_len;
1908 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1912 ip->ip_ttl -= IPTTLDEC;
1915 * If forwarding packet using same interface that it came in on,
1916 * perhaps should send a redirect to sender to shortcut a hop.
1917 * Only send redirect if source is sending directly to us,
1918 * and if packet was not source routed (or has any options).
1919 * Also, don't send redirect if forwarding using a default route
1920 * or a route modified by a redirect.
1922 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1923 !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) &&
1924 satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY &&
1925 ipsendredirects && !using_srcrt && next_hop == NULL) {
1926 u_long src = ntohl(ip->ip_src.s_addr);
1927 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa;
1929 if (rt_ifa != NULL &&
1930 (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) {
1931 if (rt->rt_flags & RTF_GATEWAY)
1932 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1934 dest = pkt_dst.s_addr;
1936 * Router requirements says to only send
1939 type = ICMP_REDIRECT;
1940 code = ICMP_REDIRECT_HOST;
1943 kprintf("redirect (%d) to %x\n", code, dest);
1948 error = ip_output(m, NULL, &fwd_ro, IP_FORWARDING, NULL, NULL);
1950 ipstat.ips_forward++;
1953 ipflow_create(&fwd_ro, mcopy);
1958 ipstat.ips_redirectsent++;
1961 ipstat.ips_cantforward++;
1968 * Send ICMP message.
1973 case 0: /* forwarded, but need redirect */
1974 /* type, code set above */
1977 case ENETUNREACH: /* shouldn't happen, checked above */
1982 type = ICMP_UNREACH;
1983 code = ICMP_UNREACH_HOST;
1987 type = ICMP_UNREACH;
1988 code = ICMP_UNREACH_NEEDFRAG;
1991 * If the packet is routed over IPsec tunnel, tell the
1992 * originator the tunnel MTU.
1993 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1996 if (fwd_ro.ro_rt != NULL) {
1997 struct secpolicy *sp = NULL;
2002 sp = ipsec4_getpolicybyaddr(mcopy,
2008 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2010 /* count IPsec header size */
2011 ipsechdr = ipsec4_hdrsiz(mcopy,
2016 * find the correct route for outer IPv4
2017 * header, compute tunnel MTU.
2020 if (sp->req != NULL && sp->req->sav != NULL &&
2021 sp->req->sav->sah != NULL) {
2022 ro = &sp->req->sav->sah->sa_route;
2023 if (ro->ro_rt != NULL &&
2024 ro->ro_rt->rt_ifp != NULL) {
2026 ro->ro_rt->rt_ifp->if_mtu;
2027 destmtu -= ipsechdr;
2036 * If the packet is routed over IPsec tunnel, tell the
2037 * originator the tunnel MTU.
2038 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2041 if (fwd_ro.ro_rt != NULL) {
2042 struct secpolicy *sp = NULL;
2047 sp = ipsec_getpolicybyaddr(mcopy,
2053 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2055 /* count IPsec header size */
2056 ipsechdr = ipsec4_hdrsiz(mcopy,
2061 * find the correct route for outer IPv4
2062 * header, compute tunnel MTU.
2065 if (sp->req != NULL &&
2066 sp->req->sav != NULL &&
2067 sp->req->sav->sah != NULL) {
2068 ro = &sp->req->sav->sah->sa_route;
2069 if (ro->ro_rt != NULL &&
2070 ro->ro_rt->rt_ifp != NULL) {
2072 ro->ro_rt->rt_ifp->if_mtu;
2073 destmtu -= ipsechdr;
2080 #else /* !IPSEC && !FAST_IPSEC */
2081 if (fwd_ro.ro_rt != NULL)
2082 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2084 ipstat.ips_cantfrag++;
2089 * A router should not generate ICMP_SOURCEQUENCH as
2090 * required in RFC1812 Requirements for IP Version 4 Routers.
2091 * Source quench could be a big problem under DoS attacks,
2092 * or if the underlying interface is rate-limited.
2093 * Those who need source quench packets may re-enable them
2094 * via the net.inet.ip.sendsourcequench sysctl.
2096 if (!ip_sendsourcequench) {
2100 type = ICMP_SOURCEQUENCH;
2105 case EACCES: /* ipfw denied packet */
2109 icmp_error(mcopy, type, code, dest, destmtu);
2111 if (fwd_ro.ro_rt != NULL)
2112 RTFREE(fwd_ro.ro_rt);
2116 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
2119 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
2123 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
2124 SCM_TIMESTAMP, SOL_SOCKET);
2126 mp = &(*mp)->m_next;
2128 if (inp->inp_flags & INP_RECVDSTADDR) {
2129 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
2130 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2132 mp = &(*mp)->m_next;
2134 if (inp->inp_flags & INP_RECVTTL) {
2135 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
2136 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
2138 mp = &(*mp)->m_next;
2142 * Moving these out of udp_input() made them even more broken
2143 * than they already were.
2145 /* options were tossed already */
2146 if (inp->inp_flags & INP_RECVOPTS) {
2147 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
2148 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
2150 mp = &(*mp)->m_next;
2152 /* ip_srcroute doesn't do what we want here, need to fix */
2153 if (inp->inp_flags & INP_RECVRETOPTS) {
2154 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
2155 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
2157 mp = &(*mp)->m_next;
2160 if (inp->inp_flags & INP_RECVIF) {
2163 struct sockaddr_dl sdl;
2166 struct sockaddr_dl *sdp;
2167 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
2169 if (((ifp = m->m_pkthdr.rcvif)) &&
2170 ((ifp->if_index != 0) && (ifp->if_index <= if_index))) {
2171 sdp = IF_LLSOCKADDR(ifp);
2173 * Change our mind and don't try copy.
2175 if ((sdp->sdl_family != AF_LINK) ||
2176 (sdp->sdl_len > sizeof(sdlbuf))) {
2179 bcopy(sdp, sdl2, sdp->sdl_len);
2183 offsetof(struct sockaddr_dl, sdl_data[0]);
2184 sdl2->sdl_family = AF_LINK;
2185 sdl2->sdl_index = 0;
2186 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2188 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2189 IP_RECVIF, IPPROTO_IP);
2191 mp = &(*mp)->m_next;
2196 * XXX these routines are called from the upper part of the kernel.
2198 * They could also be moved to ip_mroute.c, since all the RSVP
2199 * handling is done there already.
2202 ip_rsvp_init(struct socket *so)
2204 if (so->so_type != SOCK_RAW ||
2205 so->so_proto->pr_protocol != IPPROTO_RSVP)
2208 if (ip_rsvpd != NULL)
2213 * This may seem silly, but we need to be sure we don't over-increment
2214 * the RSVP counter, in case something slips up.
2229 * This may seem silly, but we need to be sure we don't over-decrement
2230 * the RSVP counter, in case something slips up.
2240 rsvp_input(struct mbuf **mp, int *offp, int proto)
2242 struct mbuf *m = *mp;
2248 if (rsvp_input_p) { /* call the real one if loaded */
2250 rsvp_input_p(mp, offp, proto);
2251 return(IPPROTO_DONE);
2254 /* Can still get packets with rsvp_on = 0 if there is a local member
2255 * of the group to which the RSVP packet is addressed. But in this
2256 * case we want to throw the packet away.
2261 return(IPPROTO_DONE);
2264 if (ip_rsvpd != NULL) {
2266 rip_input(mp, offp, proto);
2267 return(IPPROTO_DONE);
2269 /* Drop the packet */
2271 return(IPPROTO_DONE);