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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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 1.115 2008/10/28 07:09:26 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 <sys/mplock2.h>
100 #include <machine/stdarg.h>
103 #include <net/if_types.h>
104 #include <net/if_var.h>
105 #include <net/if_dl.h>
106 #include <net/pfil.h>
107 #include <net/route.h>
108 #include <net/netisr.h>
110 #include <netinet/in.h>
111 #include <netinet/in_systm.h>
112 #include <netinet/in_var.h>
113 #include <netinet/ip.h>
114 #include <netinet/in_pcb.h>
115 #include <netinet/ip_var.h>
116 #include <netinet/ip_icmp.h>
117 #include <netinet/ip_divert.h>
118 #include <netinet/ip_flow.h>
120 #include <sys/thread2.h>
121 #include <sys/msgport2.h>
122 #include <net/netmsg2.h>
124 #include <sys/socketvar.h>
126 #include <net/ipfw/ip_fw.h>
127 #include <net/dummynet/ip_dummynet.h>
130 #include <netinet6/ipsec.h>
131 #include <netproto/key/key.h>
135 #include <netproto/ipsec/ipsec.h>
136 #include <netproto/ipsec/key.h>
140 static int ip_rsvp_on;
141 struct socket *ip_rsvpd;
144 TUNABLE_INT("net.inet.ip.mpsafe", &ip_mpsafe);
146 int ipforwarding = 0;
147 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
148 &ipforwarding, 0, "Enable IP forwarding between interfaces");
150 static int ipsendredirects = 1; /* XXX */
151 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
152 &ipsendredirects, 0, "Enable sending IP redirects");
154 int ip_defttl = IPDEFTTL;
155 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
156 &ip_defttl, 0, "Maximum TTL on IP packets");
158 static int ip_dosourceroute = 0;
159 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
160 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
162 static int ip_acceptsourceroute = 0;
163 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
164 CTLFLAG_RW, &ip_acceptsourceroute, 0,
165 "Enable accepting source routed IP packets");
167 static int ip_keepfaith = 0;
168 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
170 "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
172 static int nipq = 0; /* total # of reass queues */
174 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
176 "Maximum number of IPv4 fragment reassembly queue entries");
178 static int maxfragsperpacket;
179 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
180 &maxfragsperpacket, 0,
181 "Maximum number of IPv4 fragments allowed per packet");
183 static int ip_sendsourcequench = 0;
184 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
185 &ip_sendsourcequench, 0,
186 "Enable the transmission of source quench packets");
188 int ip_do_randomid = 1;
189 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
191 "Assign random ip_id values");
193 * XXX - Setting ip_checkinterface mostly implements the receive side of
194 * the Strong ES model described in RFC 1122, but since the routing table
195 * and transmit implementation do not implement the Strong ES model,
196 * setting this to 1 results in an odd hybrid.
198 * XXX - ip_checkinterface currently must be disabled if you use ipnat
199 * to translate the destination address to another local interface.
201 * XXX - ip_checkinterface must be disabled if you add IP aliases
202 * to the loopback interface instead of the interface where the
203 * packets for those addresses are received.
205 static int ip_checkinterface = 0;
206 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
207 &ip_checkinterface, 0, "Verify packet arrives on correct interface");
209 static struct lwkt_token ipq_token = LWKT_TOKEN_MP_INITIALIZER(ipq_token);
212 static int ipprintfs = 0;
215 extern int udp_mpsafe_proto;
216 extern int tcp_mpsafe_proto;
218 extern struct domain inetdomain;
219 extern struct protosw inetsw[];
220 u_char ip_protox[IPPROTO_MAX];
221 struct in_ifaddrhead in_ifaddrheads[MAXCPU]; /* first inet address */
222 struct in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU];
223 /* inet addr hash table */
224 u_long in_ifaddrhmask; /* mask for hash table */
226 struct ip_stats ipstats_percpu[MAXCPU];
229 sysctl_ipstats(SYSCTL_HANDLER_ARGS)
233 for (cpu = 0; cpu < ncpus; ++cpu) {
234 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu],
235 sizeof(struct ip_stats))))
237 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu],
238 sizeof(struct ip_stats))))
244 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
245 0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics");
247 SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
248 &ipstat, ip_stats, "IP statistics");
251 /* Packet reassembly stuff */
252 #define IPREASS_NHASH_LOG2 6
253 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
254 #define IPREASS_HMASK (IPREASS_NHASH - 1)
255 #define IPREASS_HASH(x,y) \
256 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
258 static struct ipq ipq[IPREASS_NHASH];
261 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
262 &ip_mtu, 0, "Default MTU");
266 static int ipstealth = 0;
267 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, "");
269 static const int ipstealth = 0;
272 struct mbuf *(*ip_divert_p)(struct mbuf *, int, int);
274 struct pfil_head inet_pfil_hook;
277 * struct ip_srcrt_opt is used to store packet state while it travels
280 * XXX Note that the code even makes assumptions on the size and
281 * alignment of fields inside struct ip_srcrt so e.g. adding some
282 * fields will break the code. This needs to be fixed.
284 * We need to save the IP options in case a protocol wants to respond
285 * to an incoming packet over the same route if the packet got here
286 * using IP source routing. This allows connection establishment and
287 * maintenance when the remote end is on a network that is not known
291 struct in_addr dst; /* final destination */
292 char nop; /* one NOP to align */
293 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
294 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
297 struct ip_srcrt_opt {
299 struct ip_srcrt ip_srcrt;
302 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management");
303 static struct malloc_pipe ipq_mpipe;
305 static void save_rte(struct mbuf *, u_char *, struct in_addr);
306 static int ip_dooptions(struct mbuf *m, int, struct sockaddr_in *);
307 static void ip_freef(struct ipq *);
308 static void ip_input_handler(struct netmsg *);
311 * IP initialization: fill in IP protocol switch table.
312 * All protocols not implemented in kernel go to raw IP protocol handler.
325 * Make sure we can handle a reasonable number of fragments but
326 * cap it at 4000 (XXX).
328 mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq),
329 IFQ_MAXLEN, 4000, 0, NULL);
330 for (i = 0; i < ncpus; ++i) {
331 TAILQ_INIT(&in_ifaddrheads[i]);
332 in_ifaddrhashtbls[i] =
333 hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
335 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
338 for (i = 0; i < IPPROTO_MAX; i++)
339 ip_protox[i] = pr - inetsw;
340 for (pr = inetdomain.dom_protosw;
341 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
342 if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol) {
343 if (pr->pr_protocol != IPPROTO_RAW)
344 ip_protox[pr->pr_protocol] = pr - inetsw;
347 switch (pr->pr_protocol) {
349 if (tcp_mpsafe_proto)
350 pr->pr_flags |= PR_MPSAFE;
354 if (udp_mpsafe_proto)
355 pr->pr_flags |= PR_MPSAFE;
361 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
362 inet_pfil_hook.ph_af = AF_INET;
363 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) {
364 kprintf("%s: WARNING: unable to register pfil hook, "
365 "error %d\n", __func__, i);
368 for (i = 0; i < IPREASS_NHASH; i++)
369 ipq[i].next = ipq[i].prev = &ipq[i];
371 maxnipq = nmbclusters / 32;
372 maxfragsperpacket = 16;
374 ip_id = time_second & 0xffff;
377 * Initialize IP statistics counters for each CPU.
381 for (cpu = 0; cpu < ncpus; ++cpu) {
382 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats));
385 bzero(&ipstat, sizeof(struct ip_stats));
388 #if defined(IPSEC) || defined(FAST_IPSEC)
389 /* XXX IPSEC is not MPSAFE yet */
390 flags = NETISR_FLAG_NOTMPSAFE;
393 kprintf("ip: MPSAFE\n");
394 flags = NETISR_FLAG_MPSAFE;
396 flags = NETISR_FLAG_NOTMPSAFE;
399 netisr_register(NETISR_IP, ip_mport_in, ip_mport_pktinfo,
400 ip_input_handler, flags);
403 /* Do transport protocol processing. */
405 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip)
407 const struct protosw *pr = &inetsw[ip_protox[ip->ip_p]];
410 * Switch out to protocol's input routine.
413 pr->pr_input(m, hlen, ip->ip_p);
418 transport_processing_handler(netmsg_t netmsg)
420 struct netmsg_packet *pmsg = (struct netmsg_packet *)netmsg;
424 ip = mtod(pmsg->nm_packet, struct ip *);
425 hlen = pmsg->nm_netmsg.nm_lmsg.u.ms_result;
427 transport_processing_oncpu(pmsg->nm_packet, hlen, ip);
428 /* netmsg was embedded in the mbuf, do not reply! */
432 ip_input_handler(struct netmsg *msg0)
434 struct mbuf *m = ((struct netmsg_packet *)msg0)->nm_packet;
437 /* msg0 was embedded in the mbuf, do not reply! */
441 * IP input routine. Checksum and byte swap header. If fragmented
442 * try to reassemble. Process options. Pass to next level.
445 ip_input(struct mbuf *m)
448 struct in_ifaddr *ia = NULL;
449 struct in_ifaddr_container *iac;
452 struct in_addr pkt_dst;
453 boolean_t using_srcrt = FALSE; /* forward (by PFIL_HOOKS) */
454 struct in_addr odst; /* original dst address(NAT) */
456 struct sockaddr_in *next_hop = NULL;
459 struct tdb_ident *tdbi;
460 struct secpolicy *sp;
467 * This does necessary pullups and figures out the protocol
468 * port. If the packet is really badly formed it will blow
469 * it away and return NULL.
471 * We do not necessarily make use of the port (forwarding,
472 * defragmentation, etc).
474 port = ip_mport(&m, IP_MPORT_IN);
477 ip = mtod(m, struct ip *);
480 * Pull out certain tags
482 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
484 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
485 KKASSERT(mtag != NULL);
486 next_hop = m_tag_data(mtag);
489 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
490 /* dummynet already filtered us */
491 ip = mtod(m, struct ip *);
492 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
498 /* length checks already done in ip_mport() */
499 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf"));
501 if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
502 ipstat.ips_badvers++;
506 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
507 /* length checks already done in ip_mport() */
508 KASSERT(hlen >= sizeof(struct ip), ("IP header len too small"));
509 KASSERT(m->m_len >= hlen, ("complete IP header not in one mbuf"));
511 /* 127/8 must not appear on wire - RFC1122 */
512 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
513 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
514 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) {
515 ipstat.ips_badaddr++;
520 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
521 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
523 if (hlen == sizeof(struct ip))
524 sum = in_cksum_hdr(ip);
526 sum = in_cksum(m, hlen);
534 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
535 /* packet is dropped by traffic conditioner */
540 * Convert fields to host representation.
542 ip->ip_len = ntohs(ip->ip_len);
543 ip->ip_off = ntohs(ip->ip_off);
545 /* length checks already done in ip_mport() */
546 KASSERT(ip->ip_len >= hlen, ("total length less then header length"));
547 KASSERT(m->m_pkthdr.len >= ip->ip_len, ("mbuf too short"));
550 * Trim mbufs if longer than the IP header would have us expect.
552 if (m->m_pkthdr.len > ip->ip_len) {
553 if (m->m_len == m->m_pkthdr.len) {
554 m->m_len = ip->ip_len;
555 m->m_pkthdr.len = ip->ip_len;
557 m_adj(m, ip->ip_len - m->m_pkthdr.len);
560 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
562 * Bypass packet filtering for packets from a tunnel (gif).
564 if (ipsec_gethist(m, NULL))
570 * Right now when no processing on packet has done
571 * and it is still fresh out of network we do our black
573 * - Firewall: deny/allow/divert
574 * - Xlate: translate packet's addr/port (NAT).
575 * - Pipe: pass pkt through dummynet.
576 * - Wrap: fake packet's addr/port <unimpl.>
577 * - Encapsulate: put it in another IP and send out. <unimp.>
582 * If we've been forwarded from the output side, then
583 * skip the firewall a second time
585 if (next_hop != NULL)
589 if (!pfil_has_hooks(&inet_pfil_hook)) {
590 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
592 * Strip dummynet tags from stranded packets
594 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
595 KKASSERT(mtag != NULL);
596 m_tag_delete(m, mtag);
597 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
603 * Run through list of hooks for input packets.
605 * NB: Beware of the destination address changing (e.g.
606 * by NAT rewriting). When this happens, tell
607 * ip_forward to do the right thing.
610 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN))
612 if (m == NULL) /* consumed by filter */
614 ip = mtod(m, struct ip *);
615 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
616 using_srcrt = (odst.s_addr != ip->ip_dst.s_addr);
618 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
619 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
620 KKASSERT(mtag != NULL);
621 next_hop = m_tag_data(mtag);
623 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
627 if (m->m_pkthdr.fw_flags & FW_MBUF_REDISPATCH) {
628 m->m_pkthdr.fw_flags &= ~FW_MBUF_REDISPATCH;
632 * Process options and, if not destined for us,
633 * ship it on. ip_dooptions returns 1 when an
634 * error was detected (causing an icmp message
635 * to be sent and the original packet to be freed).
637 if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, next_hop))
640 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
641 * matter if it is destined to another node, or whether it is
642 * a multicast one, RSVP wants it! and prevents it from being forwarded
643 * anywhere else. Also checks if the rsvp daemon is running before
644 * grabbing the packet.
646 if (rsvp_on && ip->ip_p == IPPROTO_RSVP)
650 * Check our list of addresses, to see if the packet is for us.
651 * If we don't have any addresses, assume any unicast packet
652 * we receive might be for us (and let the upper layers deal
655 if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) &&
656 !(m->m_flags & (M_MCAST | M_BCAST)))
660 * Cache the destination address of the packet; this may be
661 * changed by use of 'ipfw fwd'.
663 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
666 * Enable a consistency check between the destination address
667 * and the arrival interface for a unicast packet (the RFC 1122
668 * strong ES model) if IP forwarding is disabled and the packet
669 * is not locally generated and the packet is not subject to
672 * XXX - Checking also should be disabled if the destination
673 * address is ipnat'ed to a different interface.
675 * XXX - Checking is incompatible with IP aliases added
676 * to the loopback interface instead of the interface where
677 * the packets are received.
679 checkif = ip_checkinterface &&
681 m->m_pkthdr.rcvif != NULL &&
682 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) &&
686 * Check for exact addresses in the hash bucket.
688 LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
692 * If the address matches, verify that the packet
693 * arrived via the correct interface if checking is
696 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
697 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
703 * Check for broadcast addresses.
705 * Only accept broadcast packets that arrive via the matching
706 * interface. Reception of forwarded directed broadcasts would
707 * be handled via ip_forward() and ether_output() with the loopback
708 * into the stack for SIMPLEX interfaces handled by ether_output().
710 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
711 struct ifaddr_container *ifac;
713 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid],
715 struct ifaddr *ifa = ifac->ifa;
717 if (ifa->ifa_addr == NULL) /* shutdown/startup race */
719 if (ifa->ifa_addr->sa_family != AF_INET)
722 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
725 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
728 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
733 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
734 struct in_multi *inm;
736 /* XXX Multicast is not MPSAFE yet */
739 if (ip_mrouter != NULL) {
741 * If we are acting as a multicast router, all
742 * incoming multicast packets are passed to the
743 * kernel-level multicast forwarding function.
744 * The packet is returned (relatively) intact; if
745 * ip_mforward() returns a non-zero value, the packet
746 * must be discarded, else it may be accepted below.
748 if (ip_mforward != NULL &&
749 ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) {
751 ipstat.ips_cantforward++;
757 * The process-level routing daemon needs to receive
758 * all multicast IGMP packets, whether or not this
759 * host belongs to their destination groups.
761 if (ip->ip_p == IPPROTO_IGMP) {
765 ipstat.ips_forward++;
768 * See if we belong to the destination multicast group on the
771 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
774 ipstat.ips_notmember++;
782 if (ip->ip_dst.s_addr == INADDR_BROADCAST)
784 if (ip->ip_dst.s_addr == INADDR_ANY)
788 * FAITH(Firewall Aided Internet Translator)
790 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
792 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
800 * Not for us; forward if possible and desirable.
803 ipstat.ips_cantforward++;
808 * Enforce inbound IPsec SPD.
810 if (ipsec4_in_reject(m, NULL)) {
811 ipsecstat.in_polvio++;
816 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
819 tdbi = (struct tdb_ident *)m_tag_data(mtag);
820 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
822 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
823 IP_FORWARDING, &error);
825 if (sp == NULL) { /* NB: can happen if error */
827 /*XXX error stat???*/
828 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
833 * Check security policy against packet attributes.
835 error = ipsec_in_reject(sp, m);
839 ipstat.ips_cantforward++;
843 ip_forward(m, using_srcrt, next_hop);
850 * IPSTEALTH: Process non-routing options only
851 * if the packet is destined for us.
854 hlen > sizeof(struct ip) &&
855 ip_dooptions(m, 1, next_hop))
858 /* Count the packet in the ip address stats */
860 ia->ia_ifa.if_ipackets++;
861 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
865 * If offset or IP_MF are set, must reassemble.
866 * Otherwise, nothing need be done.
867 * (We could look in the reassembly queue to see
868 * if the packet was previously fragmented,
869 * but it's not worth the time; just let them time out.)
871 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
873 * Attempt reassembly; if it succeeds, proceed.
874 * ip_reass() will return a different mbuf.
879 ip = mtod(m, struct ip *);
881 /* Get the header length of the reassembled packet */
882 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
889 * enforce IPsec policy checking if we are seeing last header.
890 * note that we do not visit this with protocols with pcb layer
891 * code - like udp/tcp/raw ip.
893 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) &&
894 ipsec4_in_reject(m, NULL)) {
895 ipsecstat.in_polvio++;
901 * enforce IPsec policy checking if we are seeing last header.
902 * note that we do not visit this with protocols with pcb layer
903 * code - like udp/tcp/raw ip.
905 if (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) {
907 * Check if the packet has already had IPsec processing
908 * done. If so, then just pass it along. This tag gets
909 * set during AH, ESP, etc. input handling, before the
910 * packet is returned to the ip input queue for delivery.
912 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
915 tdbi = (struct tdb_ident *)m_tag_data(mtag);
916 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
918 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
919 IP_FORWARDING, &error);
923 * Check security policy against packet attributes.
925 error = ipsec_in_reject(sp, m);
928 /* XXX error stat??? */
930 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
937 #endif /* FAST_IPSEC */
940 * NOTE: ip_len is now in host form and adjusted down by hlen for
941 * protocol processing.
943 * We must forward the packet to the correct protocol thread if
944 * we are not already in it.
946 ipstat.ips_delivered++;
948 if (port != &curthread->td_msgport) {
949 struct netmsg_packet *pmsg;
951 pmsg = &m->m_hdr.mh_netmsg;
952 netmsg_init(&pmsg->nm_netmsg, NULL, &netisr_apanic_rport,
953 MSGF_MPSAFE, transport_processing_handler);
955 pmsg->nm_netmsg.nm_lmsg.u.ms_result = hlen;
957 lwkt_sendmsg(port, &pmsg->nm_netmsg.nm_lmsg);
959 transport_processing_oncpu(m, hlen, ip);
968 * Take incoming datagram fragment and try to reassemble it into
969 * whole datagram. If a chain for reassembly of this datagram already
970 * exists, then it is given as fp; otherwise have to make a chain.
973 ip_reass(struct mbuf *m)
975 struct ip *ip = mtod(m, struct ip *);
976 struct mbuf *p = NULL, *q, *nq;
978 struct ipq *fp = NULL;
979 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
983 /* If maxnipq is 0, never accept fragments. */
985 ipstat.ips_fragments++;
986 ipstat.ips_fragdropped++;
991 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
993 * Look for queue of fragments of this datagram.
995 lwkt_gettoken(&ipq_token);
996 for (fp = ipq[sum].next; fp != &ipq[sum]; fp = fp->next) {
997 if (ip->ip_id == fp->ipq_id &&
998 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
999 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
1000 ip->ip_p == fp->ipq_p)
1007 * Enforce upper bound on number of fragmented packets
1008 * for which we attempt reassembly;
1009 * If maxnipq is -1, accept all fragments without limitation.
1011 if (nipq > maxnipq && maxnipq > 0) {
1013 * drop something from the tail of the current queue
1014 * before proceeding further
1016 if (ipq[sum].prev == &ipq[sum]) { /* gak */
1017 for (i = 0; i < IPREASS_NHASH; i++) {
1018 if (ipq[i].prev != &ipq[i]) {
1019 ipstat.ips_fragtimeout +=
1020 ipq[i].prev->ipq_nfrags;
1021 ip_freef(ipq[i].prev);
1026 ipstat.ips_fragtimeout +=
1027 ipq[sum].prev->ipq_nfrags;
1028 ip_freef(ipq[sum].prev);
1033 * Adjust ip_len to not reflect header,
1034 * convert offset of this to bytes.
1037 if (ip->ip_off & IP_MF) {
1039 * Make sure that fragments have a data length
1040 * that's a non-zero multiple of 8 bytes.
1042 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1043 ipstat.ips_toosmall++; /* XXX */
1047 m->m_flags |= M_FRAG;
1049 m->m_flags &= ~M_FRAG;
1053 ipstat.ips_fragments++;
1054 m->m_pkthdr.header = ip;
1057 * If the hardware has not done csum over this fragment
1058 * then csum_data is not valid at all.
1060 if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID))
1061 == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) {
1062 m->m_pkthdr.csum_data = 0;
1063 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
1067 * Presence of header sizes in mbufs
1068 * would confuse code below.
1074 * If first fragment to arrive, create a reassembly queue.
1077 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL)
1079 insque(fp, &ipq[sum]);
1082 fp->ipq_ttl = IPFRAGTTL;
1083 fp->ipq_p = ip->ip_p;
1084 fp->ipq_id = ip->ip_id;
1085 fp->ipq_src = ip->ip_src;
1086 fp->ipq_dst = ip->ip_dst;
1088 m->m_nextpkt = NULL;
1094 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1097 * Find a segment which begins after this one does.
1099 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1100 if (GETIP(q)->ip_off > ip->ip_off)
1105 * If there is a preceding segment, it may provide some of
1106 * our data already. If so, drop the data from the incoming
1107 * segment. If it provides all of our data, drop us, otherwise
1108 * stick new segment in the proper place.
1110 * If some of the data is dropped from the the preceding
1111 * segment, then it's checksum is invalidated.
1114 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1116 if (i >= ip->ip_len)
1119 m->m_pkthdr.csum_flags = 0;
1123 m->m_nextpkt = p->m_nextpkt;
1126 m->m_nextpkt = fp->ipq_frags;
1131 * While we overlap succeeding segments trim them or,
1132 * if they are completely covered, dequeue them.
1134 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1136 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1137 if (i < GETIP(q)->ip_len) {
1138 GETIP(q)->ip_len -= i;
1139 GETIP(q)->ip_off += i;
1141 q->m_pkthdr.csum_flags = 0;
1146 ipstat.ips_fragdropped++;
1148 q->m_nextpkt = NULL;
1154 * Check for complete reassembly and perform frag per packet
1157 * Frag limiting is performed here so that the nth frag has
1158 * a chance to complete the packet before we drop the packet.
1159 * As a result, n+1 frags are actually allowed per packet, but
1160 * only n will ever be stored. (n = maxfragsperpacket.)
1164 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1165 if (GETIP(q)->ip_off != next) {
1166 if (fp->ipq_nfrags > maxfragsperpacket) {
1167 ipstat.ips_fragdropped += fp->ipq_nfrags;
1172 next += GETIP(q)->ip_len;
1174 /* Make sure the last packet didn't have the IP_MF flag */
1175 if (p->m_flags & M_FRAG) {
1176 if (fp->ipq_nfrags > maxfragsperpacket) {
1177 ipstat.ips_fragdropped += fp->ipq_nfrags;
1184 * Reassembly is complete. Make sure the packet is a sane size.
1188 if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
1189 ipstat.ips_toolong++;
1190 ipstat.ips_fragdropped += fp->ipq_nfrags;
1196 * Concatenate fragments.
1203 q->m_nextpkt = NULL;
1204 for (q = nq; q != NULL; q = nq) {
1206 q->m_nextpkt = NULL;
1207 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1208 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1213 * Clean up the 1's complement checksum. Carry over 16 bits must
1214 * be added back. This assumes no more then 65535 packet fragments
1215 * were reassembled. A second carry can also occur (but not a third).
1217 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) +
1218 (m->m_pkthdr.csum_data >> 16);
1219 if (m->m_pkthdr.csum_data > 0xFFFF)
1220 m->m_pkthdr.csum_data -= 0xFFFF;
1223 * Create header for new ip packet by
1224 * modifying header of first packet;
1225 * dequeue and discard fragment reassembly header.
1226 * Make header visible.
1229 ip->ip_src = fp->ipq_src;
1230 ip->ip_dst = fp->ipq_dst;
1233 mpipe_free(&ipq_mpipe, fp);
1234 m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
1235 m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
1236 /* some debugging cruft by sklower, below, will go away soon */
1237 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1240 for (n = m; n; n = n->m_next)
1242 m->m_pkthdr.len = plen;
1245 ipstat.ips_reassembled++;
1246 lwkt_reltoken(&ipq_token);
1250 ipstat.ips_fragdropped++;
1255 lwkt_reltoken(&ipq_token);
1262 * Free a fragment reassembly header and all
1263 * associated datagrams.
1265 * Called with ipq_token held.
1268 ip_freef(struct ipq *fp)
1273 * Remove first to protect against blocking
1278 * Clean out at our leisure
1280 while (fp->ipq_frags) {
1282 fp->ipq_frags = q->m_nextpkt;
1283 q->m_nextpkt = NULL;
1286 mpipe_free(&ipq_mpipe, fp);
1291 * IP timer processing;
1292 * if a timer expires on a reassembly
1293 * queue, discard it.
1301 lwkt_gettoken(&ipq_token);
1302 for (i = 0; i < IPREASS_NHASH; i++) {
1306 while (fp != &ipq[i]) {
1309 if (fp->prev->ipq_ttl == 0) {
1310 ipstat.ips_fragtimeout += fp->prev->ipq_nfrags;
1316 * If we are over the maximum number of fragments
1317 * (due to the limit being lowered), drain off
1318 * enough to get down to the new limit.
1320 if (maxnipq >= 0 && nipq > maxnipq) {
1321 for (i = 0; i < IPREASS_NHASH; i++) {
1322 while (nipq > maxnipq &&
1323 (ipq[i].next != &ipq[i])) {
1324 ipstat.ips_fragdropped +=
1325 ipq[i].next->ipq_nfrags;
1326 ip_freef(ipq[i].next);
1330 lwkt_reltoken(&ipq_token);
1335 * Drain off all datagram fragments.
1342 lwkt_gettoken(&ipq_token);
1343 for (i = 0; i < IPREASS_NHASH; i++) {
1344 while (ipq[i].next != &ipq[i]) {
1345 ipstat.ips_fragdropped += ipq[i].next->ipq_nfrags;
1346 ip_freef(ipq[i].next);
1349 lwkt_reltoken(&ipq_token);
1354 * Do option processing on a datagram,
1355 * possibly discarding it if bad options are encountered,
1356 * or forwarding it if source-routed.
1357 * The pass argument is used when operating in the IPSTEALTH
1358 * mode to tell what options to process:
1359 * [LS]SRR (pass 0) or the others (pass 1).
1360 * The reason for as many as two passes is that when doing IPSTEALTH,
1361 * non-routing options should be processed only if the packet is for us.
1362 * Returns 1 if packet has been forwarded/freed,
1363 * 0 if the packet should be processed further.
1366 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
1368 struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET };
1369 struct ip *ip = mtod(m, struct ip *);
1371 struct in_ifaddr *ia;
1372 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB;
1373 boolean_t forward = FALSE;
1374 struct in_addr *sin, dst;
1378 cp = (u_char *)(ip + 1);
1379 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1380 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1381 opt = cp[IPOPT_OPTVAL];
1382 if (opt == IPOPT_EOL)
1384 if (opt == IPOPT_NOP)
1387 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1388 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1391 optlen = cp[IPOPT_OLEN];
1392 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1393 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1403 * Source routing with record.
1404 * Find interface with current destination address.
1405 * If none on this machine then drop if strictly routed,
1406 * or do nothing if loosely routed.
1407 * Record interface address and bring up next address
1408 * component. If strictly routed make sure next
1409 * address is on directly accessible net.
1413 if (ipstealth && pass > 0)
1415 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1416 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1419 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1420 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1423 ipaddr.sin_addr = ip->ip_dst;
1424 ia = (struct in_ifaddr *)
1425 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1427 if (opt == IPOPT_SSRR) {
1428 type = ICMP_UNREACH;
1429 code = ICMP_UNREACH_SRCFAIL;
1432 if (!ip_dosourceroute)
1433 goto nosourcerouting;
1435 * Loose routing, and not at next destination
1436 * yet; nothing to do except forward.
1440 off--; /* 0 origin */
1441 if (off > optlen - (int)sizeof(struct in_addr)) {
1443 * End of source route. Should be for us.
1445 if (!ip_acceptsourceroute)
1446 goto nosourcerouting;
1447 save_rte(m, cp, ip->ip_src);
1452 if (!ip_dosourceroute) {
1454 char buf[sizeof "aaa.bbb.ccc.ddd"];
1457 * Acting as a router, so generate ICMP
1460 strcpy(buf, inet_ntoa(ip->ip_dst));
1462 "attempted source route from %s to %s\n",
1463 inet_ntoa(ip->ip_src), buf);
1464 type = ICMP_UNREACH;
1465 code = ICMP_UNREACH_SRCFAIL;
1469 * Not acting as a router,
1473 ipstat.ips_cantforward++;
1480 * locate outgoing interface
1482 memcpy(&ipaddr.sin_addr, cp + off,
1483 sizeof ipaddr.sin_addr);
1485 if (opt == IPOPT_SSRR) {
1486 #define INA struct in_ifaddr *
1487 #define SA struct sockaddr *
1488 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr))
1490 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1492 ia = ip_rtaddr(ipaddr.sin_addr, NULL);
1495 type = ICMP_UNREACH;
1496 code = ICMP_UNREACH_SRCFAIL;
1499 ip->ip_dst = ipaddr.sin_addr;
1500 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1501 sizeof(struct in_addr));
1502 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1504 * Let ip_intr's mcast routing check handle mcast pkts
1506 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1510 if (ipstealth && pass == 0)
1512 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1513 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1516 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1517 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1521 * If no space remains, ignore.
1523 off--; /* 0 origin */
1524 if (off > optlen - (int)sizeof(struct in_addr))
1526 memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1527 sizeof ipaddr.sin_addr);
1529 * locate outgoing interface; if we're the destination,
1530 * use the incoming interface (should be same).
1532 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL &&
1533 (ia = ip_rtaddr(ipaddr.sin_addr, NULL)) == NULL) {
1534 type = ICMP_UNREACH;
1535 code = ICMP_UNREACH_HOST;
1538 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1539 sizeof(struct in_addr));
1540 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1544 if (ipstealth && pass == 0)
1546 code = cp - (u_char *)ip;
1547 if (optlen < 4 || optlen > 40) {
1548 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1551 if ((off = cp[IPOPT_OFFSET]) < 5) {
1552 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1555 if (off > optlen - (int)sizeof(int32_t)) {
1556 cp[IPOPT_OFFSET + 1] += (1 << 4);
1557 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1558 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1563 off--; /* 0 origin */
1564 sin = (struct in_addr *)(cp + off);
1565 switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1567 case IPOPT_TS_TSONLY:
1570 case IPOPT_TS_TSANDADDR:
1571 if (off + sizeof(n_time) +
1572 sizeof(struct in_addr) > optlen) {
1573 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1576 ipaddr.sin_addr = dst;
1577 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1581 memcpy(sin, &IA_SIN(ia)->sin_addr,
1582 sizeof(struct in_addr));
1583 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1584 off += sizeof(struct in_addr);
1587 case IPOPT_TS_PRESPEC:
1588 if (off + sizeof(n_time) +
1589 sizeof(struct in_addr) > optlen) {
1590 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1593 memcpy(&ipaddr.sin_addr, sin,
1594 sizeof(struct in_addr));
1595 if (ifa_ifwithaddr((SA)&ipaddr) == NULL)
1597 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1598 off += sizeof(struct in_addr);
1602 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1606 memcpy(cp + off, &ntime, sizeof(n_time));
1607 cp[IPOPT_OFFSET] += sizeof(n_time);
1610 if (forward && ipforwarding) {
1611 ip_forward(m, TRUE, next_hop);
1616 icmp_error(m, type, code, 0, 0);
1617 ipstat.ips_badoptions++;
1622 * Given address of next destination (final or next hop),
1623 * return internet address info of interface to be used to get there.
1626 ip_rtaddr(struct in_addr dst, struct route *ro0)
1628 struct route sro, *ro;
1629 struct sockaddr_in *sin;
1630 struct in_ifaddr *ia;
1635 bzero(&sro, sizeof(sro));
1639 sin = (struct sockaddr_in *)&ro->ro_dst;
1641 if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) {
1642 if (ro->ro_rt != NULL) {
1646 sin->sin_family = AF_INET;
1647 sin->sin_len = sizeof *sin;
1648 sin->sin_addr = dst;
1649 rtalloc_ign(ro, RTF_PRCLONING);
1652 if (ro->ro_rt == NULL)
1655 ia = ifatoia(ro->ro_rt->rt_ifa);
1663 * Save incoming source route for use in replies,
1664 * to be picked up later by ip_srcroute if the receiver is interested.
1667 save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1670 struct ip_srcrt_opt *opt;
1673 mtag = m_tag_get(PACKET_TAG_IPSRCRT, sizeof(*opt), MB_DONTWAIT);
1676 opt = m_tag_data(mtag);
1678 olen = option[IPOPT_OLEN];
1681 kprintf("save_rte: olen %d\n", olen);
1683 if (olen > sizeof(opt->ip_srcrt) - (1 + sizeof(dst))) {
1687 bcopy(option, opt->ip_srcrt.srcopt, olen);
1688 opt->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1689 opt->ip_srcrt.dst = dst;
1690 m_tag_prepend(m, mtag);
1694 * Retrieve incoming source route for use in replies,
1695 * in the same form used by setsockopt.
1696 * The first hop is placed before the options, will be removed later.
1699 ip_srcroute(struct mbuf *m0)
1701 struct in_addr *p, *q;
1704 struct ip_srcrt_opt *opt;
1709 mtag = m_tag_find(m0, PACKET_TAG_IPSRCRT, NULL);
1712 opt = m_tag_data(mtag);
1714 if (opt->ip_nhops == 0)
1716 m = m_get(MB_DONTWAIT, MT_HEADER);
1720 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt))
1722 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1723 m->m_len = opt->ip_nhops * sizeof(struct in_addr) +
1724 sizeof(struct in_addr) + OPTSIZ;
1727 kprintf("ip_srcroute: nhops %d mlen %d",
1728 opt->ip_nhops, m->m_len);
1733 * First save first hop for return route
1735 p = &opt->ip_srcrt.route[opt->ip_nhops - 1];
1736 *(mtod(m, struct in_addr *)) = *p--;
1739 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1743 * Copy option fields and padding (nop) to mbuf.
1745 opt->ip_srcrt.nop = IPOPT_NOP;
1746 opt->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1747 memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &opt->ip_srcrt.nop,
1749 q = (struct in_addr *)(mtod(m, caddr_t) +
1750 sizeof(struct in_addr) + OPTSIZ);
1753 * Record return path as an IP source route,
1754 * reversing the path (pointers are now aligned).
1756 while (p >= opt->ip_srcrt.route) {
1759 kprintf(" %x", ntohl(q->s_addr));
1764 * Last hop goes to final destination.
1766 *q = opt->ip_srcrt.dst;
1767 m_tag_delete(m0, mtag);
1770 kprintf(" %x\n", ntohl(q->s_addr));
1776 * Strip out IP options.
1779 ip_stripoptions(struct mbuf *m)
1782 struct ip *ip = mtod(m, struct ip *);
1786 optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1787 opts = (caddr_t)(ip + 1);
1788 datalen = m->m_len - (sizeof(struct ip) + optlen);
1789 bcopy(opts + optlen, opts, datalen);
1791 if (m->m_flags & M_PKTHDR)
1792 m->m_pkthdr.len -= optlen;
1793 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1796 u_char inetctlerrmap[PRC_NCMDS] = {
1798 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1799 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1800 EMSGSIZE, EHOSTUNREACH, 0, 0,
1802 ENOPROTOOPT, ECONNREFUSED
1806 * Forward a packet. If some error occurs return the sender
1807 * an icmp packet. Note we can't always generate a meaningful
1808 * icmp message because icmp doesn't have a large enough repertoire
1809 * of codes and types.
1811 * If not forwarding, just drop the packet. This could be confusing
1812 * if ipforwarding was zero but some routing protocol was advancing
1813 * us as a gateway to somewhere. However, we must let the routing
1814 * protocol deal with that.
1816 * The using_srcrt parameter indicates whether the packet is being forwarded
1817 * via a source route.
1820 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop)
1822 struct ip *ip = mtod(m, struct ip *);
1824 struct route fwd_ro;
1825 int error, type = 0, code = 0, destmtu = 0;
1828 struct in_addr pkt_dst;
1832 * Cache the destination address of the packet; this may be
1833 * changed by use of 'ipfw fwd'.
1835 pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst;
1839 kprintf("forward: src %x dst %x ttl %x\n",
1840 ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl);
1843 if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) {
1844 ipstat.ips_cantforward++;
1848 if (!ipstealth && ip->ip_ttl <= IPTTLDEC) {
1849 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1853 bzero(&fwd_ro, sizeof(fwd_ro));
1854 ip_rtaddr(pkt_dst, &fwd_ro);
1855 if (fwd_ro.ro_rt == NULL) {
1856 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1862 * Save the IP header and at most 8 bytes of the payload,
1863 * in case we need to generate an ICMP message to the src.
1865 * XXX this can be optimized a lot by saving the data in a local
1866 * buffer on the stack (72 bytes at most), and only allocating the
1867 * mbuf if really necessary. The vast majority of the packets
1868 * are forwarded without having to send an ICMP back (either
1869 * because unnecessary, or because rate limited), so we are
1870 * really we are wasting a lot of work here.
1872 * We don't use m_copy() because it might return a reference
1873 * to a shared cluster. Both this function and ip_output()
1874 * assume exclusive access to the IP header in `m', so any
1875 * data in a cluster may change before we reach icmp_error().
1877 MGETHDR(mcopy, MB_DONTWAIT, m->m_type);
1878 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, MB_DONTWAIT)) {
1880 * It's probably ok if the pkthdr dup fails (because
1881 * the deep copy of the tag chain failed), but for now
1882 * be conservative and just discard the copy since
1883 * code below may some day want the tags.
1888 if (mcopy != NULL) {
1889 mcopy->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8,
1891 mcopy->m_pkthdr.len = mcopy->m_len;
1892 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1896 ip->ip_ttl -= IPTTLDEC;
1899 * If forwarding packet using same interface that it came in on,
1900 * perhaps should send a redirect to sender to shortcut a hop.
1901 * Only send redirect if source is sending directly to us,
1902 * and if packet was not source routed (or has any options).
1903 * Also, don't send redirect if forwarding using a default route
1904 * or a route modified by a redirect.
1906 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1907 !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) &&
1908 satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY &&
1909 ipsendredirects && !using_srcrt && next_hop == NULL) {
1910 u_long src = ntohl(ip->ip_src.s_addr);
1911 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa;
1913 if (rt_ifa != NULL &&
1914 (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) {
1915 if (rt->rt_flags & RTF_GATEWAY)
1916 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1918 dest = pkt_dst.s_addr;
1920 * Router requirements says to only send
1923 type = ICMP_REDIRECT;
1924 code = ICMP_REDIRECT_HOST;
1927 kprintf("redirect (%d) to %x\n", code, dest);
1932 error = ip_output(m, NULL, &fwd_ro, IP_FORWARDING, NULL, NULL);
1934 ipstat.ips_forward++;
1937 ipflow_create(&fwd_ro, mcopy);
1942 ipstat.ips_redirectsent++;
1945 ipstat.ips_cantforward++;
1952 * Send ICMP message.
1957 case 0: /* forwarded, but need redirect */
1958 /* type, code set above */
1961 case ENETUNREACH: /* shouldn't happen, checked above */
1966 type = ICMP_UNREACH;
1967 code = ICMP_UNREACH_HOST;
1971 type = ICMP_UNREACH;
1972 code = ICMP_UNREACH_NEEDFRAG;
1975 * If the packet is routed over IPsec tunnel, tell the
1976 * originator the tunnel MTU.
1977 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1980 if (fwd_ro.ro_rt != NULL) {
1981 struct secpolicy *sp = NULL;
1986 sp = ipsec4_getpolicybyaddr(mcopy,
1992 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
1994 /* count IPsec header size */
1995 ipsechdr = ipsec4_hdrsiz(mcopy,
2000 * find the correct route for outer IPv4
2001 * header, compute tunnel MTU.
2004 if (sp->req != NULL && sp->req->sav != NULL &&
2005 sp->req->sav->sah != NULL) {
2006 ro = &sp->req->sav->sah->sa_route;
2007 if (ro->ro_rt != NULL &&
2008 ro->ro_rt->rt_ifp != NULL) {
2010 ro->ro_rt->rt_ifp->if_mtu;
2011 destmtu -= ipsechdr;
2020 * If the packet is routed over IPsec tunnel, tell the
2021 * originator the tunnel MTU.
2022 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2025 if (fwd_ro.ro_rt != NULL) {
2026 struct secpolicy *sp = NULL;
2031 sp = ipsec_getpolicybyaddr(mcopy,
2037 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2039 /* count IPsec header size */
2040 ipsechdr = ipsec4_hdrsiz(mcopy,
2045 * find the correct route for outer IPv4
2046 * header, compute tunnel MTU.
2049 if (sp->req != NULL &&
2050 sp->req->sav != NULL &&
2051 sp->req->sav->sah != NULL) {
2052 ro = &sp->req->sav->sah->sa_route;
2053 if (ro->ro_rt != NULL &&
2054 ro->ro_rt->rt_ifp != NULL) {
2056 ro->ro_rt->rt_ifp->if_mtu;
2057 destmtu -= ipsechdr;
2064 #else /* !IPSEC && !FAST_IPSEC */
2065 if (fwd_ro.ro_rt != NULL)
2066 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2068 ipstat.ips_cantfrag++;
2073 * A router should not generate ICMP_SOURCEQUENCH as
2074 * required in RFC1812 Requirements for IP Version 4 Routers.
2075 * Source quench could be a big problem under DoS attacks,
2076 * or if the underlying interface is rate-limited.
2077 * Those who need source quench packets may re-enable them
2078 * via the net.inet.ip.sendsourcequench sysctl.
2080 if (!ip_sendsourcequench) {
2084 type = ICMP_SOURCEQUENCH;
2089 case EACCES: /* ipfw denied packet */
2093 icmp_error(mcopy, type, code, dest, destmtu);
2095 if (fwd_ro.ro_rt != NULL)
2096 RTFREE(fwd_ro.ro_rt);
2100 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
2103 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
2107 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
2108 SCM_TIMESTAMP, SOL_SOCKET);
2110 mp = &(*mp)->m_next;
2112 if (inp->inp_flags & INP_RECVDSTADDR) {
2113 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
2114 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2116 mp = &(*mp)->m_next;
2118 if (inp->inp_flags & INP_RECVTTL) {
2119 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
2120 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
2122 mp = &(*mp)->m_next;
2126 * Moving these out of udp_input() made them even more broken
2127 * than they already were.
2129 /* options were tossed already */
2130 if (inp->inp_flags & INP_RECVOPTS) {
2131 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
2132 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
2134 mp = &(*mp)->m_next;
2136 /* ip_srcroute doesn't do what we want here, need to fix */
2137 if (inp->inp_flags & INP_RECVRETOPTS) {
2138 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
2139 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
2141 mp = &(*mp)->m_next;
2144 if (inp->inp_flags & INP_RECVIF) {
2147 struct sockaddr_dl sdl;
2150 struct sockaddr_dl *sdp;
2151 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
2153 if (((ifp = m->m_pkthdr.rcvif)) &&
2154 ((ifp->if_index != 0) && (ifp->if_index <= if_index))) {
2155 sdp = IF_LLSOCKADDR(ifp);
2157 * Change our mind and don't try copy.
2159 if ((sdp->sdl_family != AF_LINK) ||
2160 (sdp->sdl_len > sizeof(sdlbuf))) {
2163 bcopy(sdp, sdl2, sdp->sdl_len);
2167 offsetof(struct sockaddr_dl, sdl_data[0]);
2168 sdl2->sdl_family = AF_LINK;
2169 sdl2->sdl_index = 0;
2170 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2172 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2173 IP_RECVIF, IPPROTO_IP);
2175 mp = &(*mp)->m_next;
2180 * XXX these routines are called from the upper part of the kernel.
2182 * They could also be moved to ip_mroute.c, since all the RSVP
2183 * handling is done there already.
2186 ip_rsvp_init(struct socket *so)
2188 if (so->so_type != SOCK_RAW ||
2189 so->so_proto->pr_protocol != IPPROTO_RSVP)
2192 if (ip_rsvpd != NULL)
2197 * This may seem silly, but we need to be sure we don't over-increment
2198 * the RSVP counter, in case something slips up.
2213 * This may seem silly, but we need to be sure we don't over-decrement
2214 * the RSVP counter, in case something slips up.
2224 rsvp_input(struct mbuf *m, ...) /* XXX must fixup manually */
2230 off = __va_arg(ap, int);
2231 proto = __va_arg(ap, int);
2234 if (rsvp_input_p) { /* call the real one if loaded */
2235 rsvp_input_p(m, off, proto);
2239 /* Can still get packets with rsvp_on = 0 if there is a local member
2240 * of the group to which the RSVP packet is addressed. But in this
2241 * case we want to throw the packet away.
2249 if (ip_rsvpd != NULL) {
2250 rip_input(m, off, proto);
2253 /* Drop the packet */