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
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62 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
63 * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.52 2003/03/07 07:01:28 silby Exp $
68 #include "opt_bootp.h"
70 #include "opt_ipdivert.h"
71 #include "opt_ipstealth.h"
72 #include "opt_ipsec.h"
75 #include <sys/param.h>
76 #include <sys/systm.h>
78 #include <sys/malloc.h>
79 #include <sys/mpipe.h>
80 #include <sys/domain.h>
81 #include <sys/protosw.h>
82 #include <sys/socket.h>
84 #include <sys/globaldata.h>
85 #include <sys/thread.h>
86 #include <sys/kernel.h>
87 #include <sys/syslog.h>
88 #include <sys/sysctl.h>
89 #include <sys/in_cksum.h>
92 #include <sys/mplock2.h>
94 #include <machine/stdarg.h>
97 #include <net/if_types.h>
98 #include <net/if_var.h>
99 #include <net/if_dl.h>
100 #include <net/pfil.h>
101 #include <net/route.h>
102 #include <net/netisr2.h>
104 #include <netinet/in.h>
105 #include <netinet/in_systm.h>
106 #include <netinet/in_var.h>
107 #include <netinet/ip.h>
108 #include <netinet/in_pcb.h>
109 #include <netinet/ip_var.h>
110 #include <netinet/ip_icmp.h>
111 #include <netinet/ip_divert.h>
112 #include <netinet/ip_flow.h>
114 #include <sys/thread2.h>
115 #include <sys/msgport2.h>
116 #include <net/netmsg2.h>
118 #include <sys/socketvar.h>
120 #include <net/ipfw/ip_fw.h>
121 #include <net/dummynet/ip_dummynet.h>
124 #include <netinet6/ipsec.h>
125 #include <netproto/key/key.h>
129 #include <netproto/ipsec/ipsec.h>
130 #include <netproto/ipsec/key.h>
134 static int ip_rsvp_on;
135 struct socket *ip_rsvpd;
137 int ipforwarding = 0;
138 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
139 &ipforwarding, 0, "Enable IP forwarding between interfaces");
141 static int ipsendredirects = 1; /* XXX */
142 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
143 &ipsendredirects, 0, "Enable sending IP redirects");
145 int ip_defttl = IPDEFTTL;
146 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
147 &ip_defttl, 0, "Maximum TTL on IP packets");
149 static int ip_dosourceroute = 0;
150 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
151 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
153 static int ip_acceptsourceroute = 0;
154 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
155 CTLFLAG_RW, &ip_acceptsourceroute, 0,
156 "Enable accepting source routed IP packets");
158 static int ip_keepfaith = 0;
159 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
161 "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
163 static int nipq = 0; /* total # of reass queues */
165 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
167 "Maximum number of IPv4 fragment reassembly queue entries");
169 static int maxfragsperpacket;
170 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
171 &maxfragsperpacket, 0,
172 "Maximum number of IPv4 fragments allowed per packet");
174 static int ip_sendsourcequench = 0;
175 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
176 &ip_sendsourcequench, 0,
177 "Enable the transmission of source quench packets");
179 int ip_do_randomid = 1;
180 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
182 "Assign random ip_id values");
184 * XXX - Setting ip_checkinterface mostly implements the receive side of
185 * the Strong ES model described in RFC 1122, but since the routing table
186 * and transmit implementation do not implement the Strong ES model,
187 * setting this to 1 results in an odd hybrid.
189 * XXX - ip_checkinterface currently must be disabled if you use ipnat
190 * to translate the destination address to another local interface.
192 * XXX - ip_checkinterface must be disabled if you add IP aliases
193 * to the loopback interface instead of the interface where the
194 * packets for those addresses are received.
196 static int ip_checkinterface = 0;
197 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
198 &ip_checkinterface, 0, "Verify packet arrives on correct interface");
200 static u_long ip_hash_count = 0;
201 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, hash_count, CTLFLAG_RD,
202 &ip_hash_count, 0, "Number of packets hashed by IP");
205 static u_long ip_rehash_count = 0;
206 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, rehash_count, CTLFLAG_RD,
207 &ip_rehash_count, 0, "Number of packets rehashed by IP");
209 static u_long ip_dispatch_fast = 0;
210 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_fast_count, CTLFLAG_RD,
211 &ip_dispatch_fast, 0, "Number of packets handled on current CPU");
213 static u_long ip_dispatch_slow = 0;
214 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_slow_count, CTLFLAG_RD,
215 &ip_dispatch_slow, 0, "Number of packets messaged to another CPU");
218 static struct lwkt_token ipq_token = LWKT_TOKEN_INITIALIZER(ipq_token);
221 static int ipprintfs = 0;
224 extern struct domain inetdomain;
225 extern struct protosw inetsw[];
226 u_char ip_protox[IPPROTO_MAX];
227 struct in_ifaddrhead in_ifaddrheads[MAXCPU]; /* first inet address */
228 struct in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU];
229 /* inet addr hash table */
230 u_long in_ifaddrhmask; /* mask for hash table */
232 static struct mbuf *ipforward_mtemp[MAXCPU];
234 struct ip_stats ipstats_percpu[MAXCPU] __cachealign;
237 sysctl_ipstats(SYSCTL_HANDLER_ARGS)
241 for (cpu = 0; cpu < ncpus; ++cpu) {
242 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu],
243 sizeof(struct ip_stats))))
245 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu],
246 sizeof(struct ip_stats))))
252 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
253 0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics");
255 /* Packet reassembly stuff */
256 #define IPREASS_NHASH_LOG2 6
257 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
258 #define IPREASS_HMASK (IPREASS_NHASH - 1)
259 #define IPREASS_HASH(x,y) \
260 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
262 static TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH];
265 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
266 &ip_mtu, 0, "Default MTU");
270 static int ipstealth = 0;
271 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, "");
273 static const int ipstealth = 0;
276 struct mbuf *(*ip_divert_p)(struct mbuf *, int, int);
278 struct pfil_head inet_pfil_hook;
281 * struct ip_srcrt_opt is used to store packet state while it travels
284 * XXX Note that the code even makes assumptions on the size and
285 * alignment of fields inside struct ip_srcrt so e.g. adding some
286 * fields will break the code. This needs to be fixed.
288 * We need to save the IP options in case a protocol wants to respond
289 * to an incoming packet over the same route if the packet got here
290 * using IP source routing. This allows connection establishment and
291 * maintenance when the remote end is on a network that is not known
295 struct in_addr dst; /* final destination */
296 char nop; /* one NOP to align */
297 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
298 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
301 struct ip_srcrt_opt {
303 struct ip_srcrt ip_srcrt;
306 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management");
307 static struct malloc_pipe ipq_mpipe;
309 static void save_rte(struct mbuf *, u_char *, struct in_addr);
310 static int ip_dooptions(struct mbuf *m, int, struct sockaddr_in *);
311 static void ip_freef(struct ipqhead *, struct ipq *);
312 static void ip_input_handler(netmsg_t);
315 * IP initialization: fill in IP protocol switch table.
316 * All protocols not implemented in kernel go to raw IP protocol handler.
326 * Make sure we can handle a reasonable number of fragments but
327 * cap it at 4000 (XXX).
329 mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq),
330 IFQ_MAXLEN, 4000, 0, NULL, NULL, NULL);
331 for (i = 0; i < ncpus; ++i) {
332 TAILQ_INIT(&in_ifaddrheads[i]);
333 in_ifaddrhashtbls[i] =
334 hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
336 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
339 for (i = 0; i < IPPROTO_MAX; i++)
340 ip_protox[i] = pr - inetsw;
341 for (pr = inetdomain.dom_protosw;
342 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
343 if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol) {
344 if (pr->pr_protocol != IPPROTO_RAW)
345 ip_protox[pr->pr_protocol] = pr - inetsw;
349 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
350 inet_pfil_hook.ph_af = AF_INET;
351 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) {
352 kprintf("%s: WARNING: unable to register pfil hook, "
353 "error %d\n", __func__, i);
356 for (i = 0; i < IPREASS_NHASH; i++)
359 maxnipq = nmbclusters / 32;
360 maxfragsperpacket = 16;
362 ip_id = time_second & 0xffff; /* time_second survives reboots */
364 for (cpu = 0; cpu < ncpus; ++cpu) {
366 * Initialize IP statistics counters for each CPU.
368 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats));
371 * Preallocate mbuf template for forwarding
373 MGETHDR(ipforward_mtemp[cpu], MB_WAIT, MT_DATA);
376 netisr_register(NETISR_IP, ip_input_handler, ip_hashfn_in);
377 netisr_register_hashcheck(NETISR_IP, ip_hashcheck);
380 /* Do transport protocol processing. */
382 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip)
384 const struct protosw *pr = &inetsw[ip_protox[ip->ip_p]];
387 * Switch out to protocol's input routine.
390 pr->pr_input(&m, &hlen, ip->ip_p);
395 transport_processing_handler(netmsg_t msg)
397 struct netmsg_packet *pmsg = &msg->packet;
401 ip = mtod(pmsg->nm_packet, struct ip *);
402 hlen = pmsg->base.lmsg.u.ms_result;
404 transport_processing_oncpu(pmsg->nm_packet, hlen, ip);
405 /* msg was embedded in the mbuf, do not reply! */
409 ip_input_handler(netmsg_t msg)
411 ip_input(msg->packet.nm_packet);
412 /* msg was embedded in the mbuf, do not reply! */
416 * IP input routine. Checksum and byte swap header. If fragmented
417 * try to reassemble. Process options. Pass to next level.
420 ip_input(struct mbuf *m)
423 struct in_ifaddr *ia = NULL;
424 struct in_ifaddr_container *iac;
427 struct in_addr pkt_dst;
428 boolean_t check_msgport = FALSE;
429 boolean_t using_srcrt = FALSE; /* forward (by PFIL_HOOKS) */
430 struct in_addr odst; /* original dst address(NAT) */
432 struct sockaddr_in *next_hop = NULL;
435 struct tdb_ident *tdbi;
436 struct secpolicy *sp;
443 * This routine is called from numerous places which may not have
444 * characterized the packet.
446 if ((m->m_flags & M_HASH) == 0) {
447 atomic_add_long(&ip_hash_count, 1);
448 ip_hashfn(&m, 0, IP_MPORT_IN);
451 KKASSERT(m->m_flags & M_HASH);
452 check_msgport = TRUE;
454 ip = mtod(m, struct ip *);
456 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
458 * XXX handle multicast on CPU0 for now.
460 * This could happen for packets hashed by hardware
461 * using RSS, which does not differentiate multicast
462 * packets from unicast packets.
464 m->m_pkthdr.hash = 0;
465 check_msgport = TRUE;
469 &curthread->td_msgport != netisr_hashport(m->m_pkthdr.hash)) {
470 netisr_queue(NETISR_IP, m);
471 /* Requeued to other netisr msgport; done */
476 * Pull out certain tags
478 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
480 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
481 KKASSERT(mtag != NULL);
482 next_hop = m_tag_data(mtag);
485 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
486 /* dummynet already filtered us */
487 ip = mtod(m, struct ip *);
488 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
494 /* length checks already done in ip_hashfn() */
495 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf"));
497 if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
498 ipstat.ips_badvers++;
502 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
503 /* length checks already done in ip_hashfn() */
504 KASSERT(hlen >= sizeof(struct ip), ("IP header len too small"));
505 KASSERT(m->m_len >= hlen, ("complete IP header not in one mbuf"));
507 /* 127/8 must not appear on wire - RFC1122 */
508 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
509 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
510 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) {
511 ipstat.ips_badaddr++;
516 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
517 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
519 if (hlen == sizeof(struct ip))
520 sum = in_cksum_hdr(ip);
522 sum = in_cksum(m, hlen);
530 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
531 /* packet is dropped by traffic conditioner */
536 * Convert fields to host representation.
538 ip->ip_len = ntohs(ip->ip_len);
539 ip->ip_off = ntohs(ip->ip_off);
541 /* length checks already done in ip_hashfn() */
542 KASSERT(ip->ip_len >= hlen, ("total length less then header length"));
543 KASSERT(m->m_pkthdr.len >= ip->ip_len, ("mbuf too short"));
546 * Trim mbufs if longer than the IP header would have us expect.
548 if (m->m_pkthdr.len > ip->ip_len) {
549 if (m->m_len == m->m_pkthdr.len) {
550 m->m_len = ip->ip_len;
551 m->m_pkthdr.len = ip->ip_len;
553 m_adj(m, ip->ip_len - m->m_pkthdr.len);
556 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
558 * Bypass packet filtering for packets from a tunnel (gif).
560 if (ipsec_gethist(m, NULL))
566 * Right now when no processing on packet has done
567 * and it is still fresh out of network we do our black
569 * - Firewall: deny/allow/divert
570 * - Xlate: translate packet's addr/port (NAT).
571 * - Pipe: pass pkt through dummynet.
572 * - Wrap: fake packet's addr/port <unimpl.>
573 * - Encapsulate: put it in another IP and send out. <unimp.>
578 * If we've been forwarded from the output side, then
579 * skip the firewall a second time
581 if (next_hop != NULL)
585 if (!pfil_has_hooks(&inet_pfil_hook)) {
586 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
588 * Strip dummynet tags from stranded packets
590 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
591 KKASSERT(mtag != NULL);
592 m_tag_delete(m, mtag);
593 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
599 * Run through list of hooks for input packets.
601 * NOTE! If the packet is rewritten pf/ipfw/whoever must
605 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN))
607 if (m == NULL) /* consumed by filter */
609 ip = mtod(m, struct ip *);
610 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
611 using_srcrt = (odst.s_addr != ip->ip_dst.s_addr);
613 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
614 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
615 KKASSERT(mtag != NULL);
616 next_hop = m_tag_data(mtag);
618 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
622 if (m->m_pkthdr.fw_flags & FW_MBUF_REDISPATCH) {
623 m->m_pkthdr.fw_flags &= ~FW_MBUF_REDISPATCH;
627 * Process options and, if not destined for us,
628 * ship it on. ip_dooptions returns 1 when an
629 * error was detected (causing an icmp message
630 * to be sent and the original packet to be freed).
632 if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, next_hop))
635 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
636 * matter if it is destined to another node, or whether it is
637 * a multicast one, RSVP wants it! and prevents it from being forwarded
638 * anywhere else. Also checks if the rsvp daemon is running before
639 * grabbing the packet.
641 if (rsvp_on && ip->ip_p == IPPROTO_RSVP)
645 * Check our list of addresses, to see if the packet is for us.
646 * If we don't have any addresses, assume any unicast packet
647 * we receive might be for us (and let the upper layers deal
650 if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) &&
651 !(m->m_flags & (M_MCAST | M_BCAST)))
655 * Cache the destination address of the packet; this may be
656 * changed by use of 'ipfw fwd'.
658 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
661 * Enable a consistency check between the destination address
662 * and the arrival interface for a unicast packet (the RFC 1122
663 * strong ES model) if IP forwarding is disabled and the packet
664 * is not locally generated and the packet is not subject to
667 * XXX - Checking also should be disabled if the destination
668 * address is ipnat'ed to a different interface.
670 * XXX - Checking is incompatible with IP aliases added
671 * to the loopback interface instead of the interface where
672 * the packets are received.
674 checkif = ip_checkinterface &&
676 m->m_pkthdr.rcvif != NULL &&
677 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) &&
681 * Check for exact addresses in the hash bucket.
683 LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
687 * If the address matches, verify that the packet
688 * arrived via the correct interface if checking is
691 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
692 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
698 * Check for broadcast addresses.
700 * Only accept broadcast packets that arrive via the matching
701 * interface. Reception of forwarded directed broadcasts would
702 * be handled via ip_forward() and ether_output() with the loopback
703 * into the stack for SIMPLEX interfaces handled by ether_output().
705 if (m->m_pkthdr.rcvif != NULL &&
706 m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
707 struct ifaddr_container *ifac;
709 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid],
711 struct ifaddr *ifa = ifac->ifa;
713 if (ifa->ifa_addr == NULL) /* shutdown/startup race */
715 if (ifa->ifa_addr->sa_family != AF_INET)
718 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
721 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
724 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
729 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
730 struct in_multi *inm;
732 if (ip_mrouter != NULL) {
733 /* XXX Multicast routing is not MPSAFE yet */
737 * If we are acting as a multicast router, all
738 * incoming multicast packets are passed to the
739 * kernel-level multicast forwarding function.
740 * The packet is returned (relatively) intact; if
741 * ip_mforward() returns a non-zero value, the packet
742 * must be discarded, else it may be accepted below.
744 if (ip_mforward != NULL &&
745 ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) {
747 ipstat.ips_cantforward++;
755 * The process-level routing daemon needs to receive
756 * all multicast IGMP packets, whether or not this
757 * host belongs to their destination groups.
759 if (ip->ip_p == IPPROTO_IGMP)
761 ipstat.ips_forward++;
764 * See if we belong to the destination multicast group on the
767 inm = IN_LOOKUP_MULTI(&ip->ip_dst, m->m_pkthdr.rcvif);
769 ipstat.ips_notmember++;
775 if (ip->ip_dst.s_addr == INADDR_BROADCAST)
777 if (ip->ip_dst.s_addr == INADDR_ANY)
781 * FAITH(Firewall Aided Internet Translator)
783 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
785 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
793 * Not for us; forward if possible and desirable.
796 ipstat.ips_cantforward++;
801 * Enforce inbound IPsec SPD.
803 if (ipsec4_in_reject(m, NULL)) {
804 ipsecstat.in_polvio++;
809 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
812 tdbi = (struct tdb_ident *)m_tag_data(mtag);
813 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
815 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
816 IP_FORWARDING, &error);
818 if (sp == NULL) { /* NB: can happen if error */
820 /*XXX error stat???*/
821 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
826 * Check security policy against packet attributes.
828 error = ipsec_in_reject(sp, m);
832 ipstat.ips_cantforward++;
836 ip_forward(m, using_srcrt, next_hop);
843 * IPSTEALTH: Process non-routing options only
844 * if the packet is destined for us.
847 hlen > sizeof(struct ip) &&
848 ip_dooptions(m, 1, next_hop))
851 /* Count the packet in the ip address stats */
853 IFA_STAT_INC(&ia->ia_ifa, ipackets, 1);
854 IFA_STAT_INC(&ia->ia_ifa, ibytes, m->m_pkthdr.len);
858 * If offset or IP_MF are set, must reassemble.
859 * Otherwise, nothing need be done.
860 * (We could look in the reassembly queue to see
861 * if the packet was previously fragmented,
862 * but it's not worth the time; just let them time out.)
864 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
866 * Attempt reassembly; if it succeeds, proceed. ip_reass()
867 * will return a different mbuf.
869 * NOTE: ip_reass() returns m with M_HASH cleared to force
870 * us to recharacterize the packet.
875 ip = mtod(m, struct ip *);
877 /* Get the header length of the reassembled packet */
878 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
885 * enforce IPsec policy checking if we are seeing last header.
886 * note that we do not visit this with protocols with pcb layer
887 * code - like udp/tcp/raw ip.
889 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) &&
890 ipsec4_in_reject(m, NULL)) {
891 ipsecstat.in_polvio++;
897 * enforce IPsec policy checking if we are seeing last header.
898 * note that we do not visit this with protocols with pcb layer
899 * code - like udp/tcp/raw ip.
901 if (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) {
903 * Check if the packet has already had IPsec processing
904 * done. If so, then just pass it along. This tag gets
905 * set during AH, ESP, etc. input handling, before the
906 * packet is returned to the ip input queue for delivery.
908 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
911 tdbi = (struct tdb_ident *)m_tag_data(mtag);
912 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
914 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
915 IP_FORWARDING, &error);
919 * Check security policy against packet attributes.
921 error = ipsec_in_reject(sp, m);
924 /* XXX error stat??? */
926 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
933 #endif /* FAST_IPSEC */
936 * We must forward the packet to the correct protocol thread if
937 * we are not already in it.
939 * NOTE: ip_len is now in host form. ip_len is not adjusted
940 * further for protocol processing, instead we pass hlen
941 * to the protosw and let it deal with it.
943 ipstat.ips_delivered++;
945 if ((m->m_flags & M_HASH) == 0) {
947 atomic_add_long(&ip_rehash_count, 1);
949 ip->ip_len = htons(ip->ip_len + hlen);
950 ip->ip_off = htons(ip->ip_off);
952 ip_hashfn(&m, 0, IP_MPORT_IN);
956 ip = mtod(m, struct ip *);
957 ip->ip_len = ntohs(ip->ip_len) - hlen;
958 ip->ip_off = ntohs(ip->ip_off);
959 KKASSERT(m->m_flags & M_HASH);
961 port = netisr_hashport(m->m_pkthdr.hash);
963 if (port != &curthread->td_msgport) {
964 struct netmsg_packet *pmsg;
967 atomic_add_long(&ip_dispatch_slow, 1);
970 pmsg = &m->m_hdr.mh_netmsg;
971 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport,
972 0, transport_processing_handler);
974 pmsg->base.lmsg.u.ms_result = hlen;
975 lwkt_sendmsg(port, &pmsg->base.lmsg);
978 atomic_add_long(&ip_dispatch_fast, 1);
980 transport_processing_oncpu(m, hlen, ip);
989 * Take incoming datagram fragment and try to reassemble it into
990 * whole datagram. If a chain for reassembly of this datagram already
991 * exists, then it is given as fp; otherwise have to make a chain.
994 ip_reass(struct mbuf *m)
996 struct ip *ip = mtod(m, struct ip *);
997 struct mbuf *p = NULL, *q, *nq;
999 struct ipq *fp = NULL;
1000 struct ipqhead *head;
1001 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1005 /* If maxnipq is 0, never accept fragments. */
1007 ipstat.ips_fragments++;
1008 ipstat.ips_fragdropped++;
1013 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
1015 * Look for queue of fragments of this datagram.
1017 lwkt_gettoken(&ipq_token);
1019 TAILQ_FOREACH(fp, head, ipq_list) {
1020 if (ip->ip_id == fp->ipq_id &&
1021 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
1022 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
1023 ip->ip_p == fp->ipq_p)
1030 * Enforce upper bound on number of fragmented packets
1031 * for which we attempt reassembly;
1032 * If maxnipq is -1, accept all fragments without limitation.
1034 if (nipq > maxnipq && maxnipq > 0) {
1036 * drop something from the tail of the current queue
1037 * before proceeding further
1039 struct ipq *q = TAILQ_LAST(head, ipqhead);
1042 * The current queue is empty,
1043 * so drop from one of the others.
1045 for (i = 0; i < IPREASS_NHASH; i++) {
1046 struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead);
1048 ipstat.ips_fragtimeout += r->ipq_nfrags;
1049 ip_freef(&ipq[i], r);
1054 ipstat.ips_fragtimeout += q->ipq_nfrags;
1060 * Adjust ip_len to not reflect header,
1061 * convert offset of this to bytes.
1064 if (ip->ip_off & IP_MF) {
1066 * Make sure that fragments have a data length
1067 * that's a non-zero multiple of 8 bytes.
1069 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1070 ipstat.ips_toosmall++; /* XXX */
1074 m->m_flags |= M_FRAG;
1076 m->m_flags &= ~M_FRAG;
1080 ipstat.ips_fragments++;
1081 m->m_pkthdr.header = ip;
1084 * If the hardware has not done csum over this fragment
1085 * then csum_data is not valid at all.
1087 if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID))
1088 == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) {
1089 m->m_pkthdr.csum_data = 0;
1090 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
1094 * Presence of header sizes in mbufs
1095 * would confuse code below.
1101 * If first fragment to arrive, create a reassembly queue.
1104 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL)
1106 TAILQ_INSERT_HEAD(head, fp, ipq_list);
1109 fp->ipq_ttl = IPFRAGTTL;
1110 fp->ipq_p = ip->ip_p;
1111 fp->ipq_id = ip->ip_id;
1112 fp->ipq_src = ip->ip_src;
1113 fp->ipq_dst = ip->ip_dst;
1115 m->m_nextpkt = NULL;
1121 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1124 * Find a segment which begins after this one does.
1126 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1127 if (GETIP(q)->ip_off > ip->ip_off)
1132 * If there is a preceding segment, it may provide some of
1133 * our data already. If so, drop the data from the incoming
1134 * segment. If it provides all of our data, drop us, otherwise
1135 * stick new segment in the proper place.
1137 * If some of the data is dropped from the the preceding
1138 * segment, then it's checksum is invalidated.
1141 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1143 if (i >= ip->ip_len)
1146 m->m_pkthdr.csum_flags = 0;
1150 m->m_nextpkt = p->m_nextpkt;
1153 m->m_nextpkt = fp->ipq_frags;
1158 * While we overlap succeeding segments trim them or,
1159 * if they are completely covered, dequeue them.
1161 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1163 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1164 if (i < GETIP(q)->ip_len) {
1165 GETIP(q)->ip_len -= i;
1166 GETIP(q)->ip_off += i;
1168 q->m_pkthdr.csum_flags = 0;
1173 ipstat.ips_fragdropped++;
1175 q->m_nextpkt = NULL;
1181 * Check for complete reassembly and perform frag per packet
1184 * Frag limiting is performed here so that the nth frag has
1185 * a chance to complete the packet before we drop the packet.
1186 * As a result, n+1 frags are actually allowed per packet, but
1187 * only n will ever be stored. (n = maxfragsperpacket.)
1191 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1192 if (GETIP(q)->ip_off != next) {
1193 if (fp->ipq_nfrags > maxfragsperpacket) {
1194 ipstat.ips_fragdropped += fp->ipq_nfrags;
1199 next += GETIP(q)->ip_len;
1201 /* Make sure the last packet didn't have the IP_MF flag */
1202 if (p->m_flags & M_FRAG) {
1203 if (fp->ipq_nfrags > maxfragsperpacket) {
1204 ipstat.ips_fragdropped += fp->ipq_nfrags;
1211 * Reassembly is complete. Make sure the packet is a sane size.
1215 if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
1216 ipstat.ips_toolong++;
1217 ipstat.ips_fragdropped += fp->ipq_nfrags;
1223 * Concatenate fragments.
1230 q->m_nextpkt = NULL;
1231 for (q = nq; q != NULL; q = nq) {
1233 q->m_nextpkt = NULL;
1234 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1235 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1240 * Clean up the 1's complement checksum. Carry over 16 bits must
1241 * be added back. This assumes no more then 65535 packet fragments
1242 * were reassembled. A second carry can also occur (but not a third).
1244 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) +
1245 (m->m_pkthdr.csum_data >> 16);
1246 if (m->m_pkthdr.csum_data > 0xFFFF)
1247 m->m_pkthdr.csum_data -= 0xFFFF;
1250 * Create header for new ip packet by
1251 * modifying header of first packet;
1252 * dequeue and discard fragment reassembly header.
1253 * Make header visible.
1256 ip->ip_src = fp->ipq_src;
1257 ip->ip_dst = fp->ipq_dst;
1258 TAILQ_REMOVE(head, fp, ipq_list);
1260 mpipe_free(&ipq_mpipe, fp);
1261 m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
1262 m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
1263 /* some debugging cruft by sklower, below, will go away soon */
1264 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1267 for (n = m; n; n = n->m_next)
1269 m->m_pkthdr.len = plen;
1273 * Reassembly complete, return the next protocol.
1275 * Be sure to clear M_HASH to force the packet
1276 * to be re-characterized.
1278 * Clear M_FRAG, we are no longer a fragment.
1280 m->m_flags &= ~(M_HASH | M_FRAG);
1282 ipstat.ips_reassembled++;
1283 lwkt_reltoken(&ipq_token);
1287 ipstat.ips_fragdropped++;
1292 lwkt_reltoken(&ipq_token);
1299 * Free a fragment reassembly header and all
1300 * associated datagrams.
1302 * Called with ipq_token held.
1305 ip_freef(struct ipqhead *fhp, struct ipq *fp)
1310 * Remove first to protect against blocking
1312 TAILQ_REMOVE(fhp, fp, ipq_list);
1315 * Clean out at our leisure
1317 while (fp->ipq_frags) {
1319 fp->ipq_frags = q->m_nextpkt;
1320 q->m_nextpkt = NULL;
1323 mpipe_free(&ipq_mpipe, fp);
1328 * IP timer processing;
1329 * if a timer expires on a reassembly
1330 * queue, discard it.
1335 struct ipq *fp, *fp_temp;
1336 struct ipqhead *head;
1339 lwkt_gettoken(&ipq_token);
1340 for (i = 0; i < IPREASS_NHASH; i++) {
1342 TAILQ_FOREACH_MUTABLE(fp, head, ipq_list, fp_temp) {
1343 if (--fp->ipq_ttl == 0) {
1344 ipstat.ips_fragtimeout += fp->ipq_nfrags;
1350 * If we are over the maximum number of fragments
1351 * (due to the limit being lowered), drain off
1352 * enough to get down to the new limit.
1354 if (maxnipq >= 0 && nipq > maxnipq) {
1355 for (i = 0; i < IPREASS_NHASH; i++) {
1357 while (nipq > maxnipq && !TAILQ_EMPTY(head)) {
1358 ipstat.ips_fragdropped +=
1359 TAILQ_FIRST(head)->ipq_nfrags;
1360 ip_freef(head, TAILQ_FIRST(head));
1364 lwkt_reltoken(&ipq_token);
1369 * Drain off all datagram fragments.
1374 struct ipqhead *head;
1377 lwkt_gettoken(&ipq_token);
1378 for (i = 0; i < IPREASS_NHASH; i++) {
1380 while (!TAILQ_EMPTY(head)) {
1381 ipstat.ips_fragdropped += TAILQ_FIRST(head)->ipq_nfrags;
1382 ip_freef(head, TAILQ_FIRST(head));
1385 lwkt_reltoken(&ipq_token);
1390 * Do option processing on a datagram,
1391 * possibly discarding it if bad options are encountered,
1392 * or forwarding it if source-routed.
1393 * The pass argument is used when operating in the IPSTEALTH
1394 * mode to tell what options to process:
1395 * [LS]SRR (pass 0) or the others (pass 1).
1396 * The reason for as many as two passes is that when doing IPSTEALTH,
1397 * non-routing options should be processed only if the packet is for us.
1398 * Returns 1 if packet has been forwarded/freed,
1399 * 0 if the packet should be processed further.
1402 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
1404 struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET };
1405 struct ip *ip = mtod(m, struct ip *);
1407 struct in_ifaddr *ia;
1408 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB;
1409 boolean_t forward = FALSE;
1410 struct in_addr *sin, dst;
1414 cp = (u_char *)(ip + 1);
1415 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1416 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1417 opt = cp[IPOPT_OPTVAL];
1418 if (opt == IPOPT_EOL)
1420 if (opt == IPOPT_NOP)
1423 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1424 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1427 optlen = cp[IPOPT_OLEN];
1428 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1429 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1439 * Source routing with record.
1440 * Find interface with current destination address.
1441 * If none on this machine then drop if strictly routed,
1442 * or do nothing if loosely routed.
1443 * Record interface address and bring up next address
1444 * component. If strictly routed make sure next
1445 * address is on directly accessible net.
1449 if (ipstealth && pass > 0)
1451 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1452 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1455 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1456 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1459 ipaddr.sin_addr = ip->ip_dst;
1460 ia = (struct in_ifaddr *)
1461 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1463 if (opt == IPOPT_SSRR) {
1464 type = ICMP_UNREACH;
1465 code = ICMP_UNREACH_SRCFAIL;
1468 if (!ip_dosourceroute)
1469 goto nosourcerouting;
1471 * Loose routing, and not at next destination
1472 * yet; nothing to do except forward.
1476 off--; /* 0 origin */
1477 if (off > optlen - (int)sizeof(struct in_addr)) {
1479 * End of source route. Should be for us.
1481 if (!ip_acceptsourceroute)
1482 goto nosourcerouting;
1483 save_rte(m, cp, ip->ip_src);
1488 if (!ip_dosourceroute) {
1490 char buf[sizeof "aaa.bbb.ccc.ddd"];
1493 * Acting as a router, so generate ICMP
1496 strcpy(buf, inet_ntoa(ip->ip_dst));
1498 "attempted source route from %s to %s\n",
1499 inet_ntoa(ip->ip_src), buf);
1500 type = ICMP_UNREACH;
1501 code = ICMP_UNREACH_SRCFAIL;
1505 * Not acting as a router,
1509 ipstat.ips_cantforward++;
1516 * locate outgoing interface
1518 memcpy(&ipaddr.sin_addr, cp + off,
1519 sizeof ipaddr.sin_addr);
1521 if (opt == IPOPT_SSRR) {
1522 #define INA struct in_ifaddr *
1523 #define SA struct sockaddr *
1524 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr))
1526 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1528 ia = ip_rtaddr(ipaddr.sin_addr, NULL);
1531 type = ICMP_UNREACH;
1532 code = ICMP_UNREACH_SRCFAIL;
1535 ip->ip_dst = ipaddr.sin_addr;
1536 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1537 sizeof(struct in_addr));
1538 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1540 * Let ip_intr's mcast routing check handle mcast pkts
1542 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1546 if (ipstealth && pass == 0)
1548 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1549 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1552 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1553 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1557 * If no space remains, ignore.
1559 off--; /* 0 origin */
1560 if (off > optlen - (int)sizeof(struct in_addr))
1562 memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1563 sizeof ipaddr.sin_addr);
1565 * locate outgoing interface; if we're the destination,
1566 * use the incoming interface (should be same).
1568 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL &&
1569 (ia = ip_rtaddr(ipaddr.sin_addr, NULL)) == NULL) {
1570 type = ICMP_UNREACH;
1571 code = ICMP_UNREACH_HOST;
1574 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1575 sizeof(struct in_addr));
1576 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1580 if (ipstealth && pass == 0)
1582 code = cp - (u_char *)ip;
1583 if (optlen < 4 || optlen > 40) {
1584 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1587 if ((off = cp[IPOPT_OFFSET]) < 5) {
1588 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1591 if (off > optlen - (int)sizeof(int32_t)) {
1592 cp[IPOPT_OFFSET + 1] += (1 << 4);
1593 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1594 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1599 off--; /* 0 origin */
1600 sin = (struct in_addr *)(cp + off);
1601 switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1603 case IPOPT_TS_TSONLY:
1606 case IPOPT_TS_TSANDADDR:
1607 if (off + sizeof(n_time) +
1608 sizeof(struct in_addr) > optlen) {
1609 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1612 ipaddr.sin_addr = dst;
1613 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1617 memcpy(sin, &IA_SIN(ia)->sin_addr,
1618 sizeof(struct in_addr));
1619 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1620 off += sizeof(struct in_addr);
1623 case IPOPT_TS_PRESPEC:
1624 if (off + sizeof(n_time) +
1625 sizeof(struct in_addr) > optlen) {
1626 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1629 memcpy(&ipaddr.sin_addr, sin,
1630 sizeof(struct in_addr));
1631 if (ifa_ifwithaddr((SA)&ipaddr) == NULL)
1633 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1634 off += sizeof(struct in_addr);
1638 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1642 memcpy(cp + off, &ntime, sizeof(n_time));
1643 cp[IPOPT_OFFSET] += sizeof(n_time);
1646 if (forward && ipforwarding) {
1647 ip_forward(m, TRUE, next_hop);
1652 icmp_error(m, type, code, 0, 0);
1653 ipstat.ips_badoptions++;
1658 * Given address of next destination (final or next hop),
1659 * return internet address info of interface to be used to get there.
1662 ip_rtaddr(struct in_addr dst, struct route *ro0)
1664 struct route sro, *ro;
1665 struct sockaddr_in *sin;
1666 struct in_ifaddr *ia;
1671 bzero(&sro, sizeof(sro));
1675 sin = (struct sockaddr_in *)&ro->ro_dst;
1677 if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) {
1678 if (ro->ro_rt != NULL) {
1682 sin->sin_family = AF_INET;
1683 sin->sin_len = sizeof *sin;
1684 sin->sin_addr = dst;
1685 rtalloc_ign(ro, RTF_PRCLONING);
1688 if (ro->ro_rt == NULL)
1691 ia = ifatoia(ro->ro_rt->rt_ifa);
1699 * Save incoming source route for use in replies,
1700 * to be picked up later by ip_srcroute if the receiver is interested.
1703 save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1706 struct ip_srcrt_opt *opt;
1709 mtag = m_tag_get(PACKET_TAG_IPSRCRT, sizeof(*opt), MB_DONTWAIT);
1712 opt = m_tag_data(mtag);
1714 olen = option[IPOPT_OLEN];
1717 kprintf("save_rte: olen %d\n", olen);
1719 if (olen > sizeof(opt->ip_srcrt) - (1 + sizeof(dst))) {
1723 bcopy(option, opt->ip_srcrt.srcopt, olen);
1724 opt->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1725 opt->ip_srcrt.dst = dst;
1726 m_tag_prepend(m, mtag);
1730 * Retrieve incoming source route for use in replies,
1731 * in the same form used by setsockopt.
1732 * The first hop is placed before the options, will be removed later.
1735 ip_srcroute(struct mbuf *m0)
1737 struct in_addr *p, *q;
1740 struct ip_srcrt_opt *opt;
1745 mtag = m_tag_find(m0, PACKET_TAG_IPSRCRT, NULL);
1748 opt = m_tag_data(mtag);
1750 if (opt->ip_nhops == 0)
1752 m = m_get(MB_DONTWAIT, MT_HEADER);
1756 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt))
1758 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1759 m->m_len = opt->ip_nhops * sizeof(struct in_addr) +
1760 sizeof(struct in_addr) + OPTSIZ;
1763 kprintf("ip_srcroute: nhops %d mlen %d",
1764 opt->ip_nhops, m->m_len);
1769 * First save first hop for return route
1771 p = &opt->ip_srcrt.route[opt->ip_nhops - 1];
1772 *(mtod(m, struct in_addr *)) = *p--;
1775 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1779 * Copy option fields and padding (nop) to mbuf.
1781 opt->ip_srcrt.nop = IPOPT_NOP;
1782 opt->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1783 memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &opt->ip_srcrt.nop,
1785 q = (struct in_addr *)(mtod(m, caddr_t) +
1786 sizeof(struct in_addr) + OPTSIZ);
1789 * Record return path as an IP source route,
1790 * reversing the path (pointers are now aligned).
1792 while (p >= opt->ip_srcrt.route) {
1795 kprintf(" %x", ntohl(q->s_addr));
1800 * Last hop goes to final destination.
1802 *q = opt->ip_srcrt.dst;
1803 m_tag_delete(m0, mtag);
1806 kprintf(" %x\n", ntohl(q->s_addr));
1812 * Strip out IP options.
1815 ip_stripoptions(struct mbuf *m)
1818 struct ip *ip = mtod(m, struct ip *);
1822 optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1823 opts = (caddr_t)(ip + 1);
1824 datalen = m->m_len - (sizeof(struct ip) + optlen);
1825 bcopy(opts + optlen, opts, datalen);
1827 if (m->m_flags & M_PKTHDR)
1828 m->m_pkthdr.len -= optlen;
1829 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1832 u_char inetctlerrmap[PRC_NCMDS] = {
1834 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1835 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1836 EMSGSIZE, EHOSTUNREACH, 0, 0,
1838 ENOPROTOOPT, ECONNREFUSED
1842 * Forward a packet. If some error occurs return the sender
1843 * an icmp packet. Note we can't always generate a meaningful
1844 * icmp message because icmp doesn't have a large enough repertoire
1845 * of codes and types.
1847 * If not forwarding, just drop the packet. This could be confusing
1848 * if ipforwarding was zero but some routing protocol was advancing
1849 * us as a gateway to somewhere. However, we must let the routing
1850 * protocol deal with that.
1852 * The using_srcrt parameter indicates whether the packet is being forwarded
1853 * via a source route.
1856 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop)
1858 struct ip *ip = mtod(m, struct ip *);
1860 struct route fwd_ro;
1861 int error, type = 0, code = 0, destmtu = 0;
1862 struct mbuf *mcopy, *mtemp = NULL;
1864 struct in_addr pkt_dst;
1868 * Cache the destination address of the packet; this may be
1869 * changed by use of 'ipfw fwd'.
1871 pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst;
1875 kprintf("forward: src %x dst %x ttl %x\n",
1876 ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl);
1879 if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) {
1880 ipstat.ips_cantforward++;
1884 if (!ipstealth && ip->ip_ttl <= IPTTLDEC) {
1885 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1889 bzero(&fwd_ro, sizeof(fwd_ro));
1890 ip_rtaddr(pkt_dst, &fwd_ro);
1891 if (fwd_ro.ro_rt == NULL) {
1892 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1897 if (curthread->td_type == TD_TYPE_NETISR) {
1899 * Save the IP header and at most 8 bytes of the payload,
1900 * in case we need to generate an ICMP message to the src.
1902 mtemp = ipforward_mtemp[mycpuid];
1903 KASSERT((mtemp->m_flags & M_EXT) == 0 &&
1904 mtemp->m_data == mtemp->m_pktdat &&
1905 m_tag_first(mtemp) == NULL,
1906 ("ip_forward invalid mtemp1"));
1908 if (!m_dup_pkthdr(mtemp, m, MB_DONTWAIT)) {
1910 * It's probably ok if the pkthdr dup fails (because
1911 * the deep copy of the tag chain failed), but for now
1912 * be conservative and just discard the copy since
1913 * code below may some day want the tags.
1917 mtemp->m_type = m->m_type;
1918 mtemp->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8,
1920 mtemp->m_pkthdr.len = mtemp->m_len;
1921 m_copydata(m, 0, mtemp->m_len, mtod(mtemp, caddr_t));
1926 ip->ip_ttl -= IPTTLDEC;
1929 * If forwarding packet using same interface that it came in on,
1930 * perhaps should send a redirect to sender to shortcut a hop.
1931 * Only send redirect if source is sending directly to us,
1932 * and if packet was not source routed (or has any options).
1933 * Also, don't send redirect if forwarding using a default route
1934 * or a route modified by a redirect.
1936 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1937 !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) &&
1938 satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY &&
1939 ipsendredirects && !using_srcrt && next_hop == NULL) {
1940 u_long src = ntohl(ip->ip_src.s_addr);
1941 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa;
1943 if (rt_ifa != NULL &&
1944 (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) {
1945 if (rt->rt_flags & RTF_GATEWAY)
1946 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1948 dest = pkt_dst.s_addr;
1950 * Router requirements says to only send
1953 type = ICMP_REDIRECT;
1954 code = ICMP_REDIRECT_HOST;
1957 kprintf("redirect (%d) to %x\n", code, dest);
1962 error = ip_output(m, NULL, &fwd_ro, IP_FORWARDING, NULL, NULL);
1964 ipstat.ips_forward++;
1967 ipflow_create(&fwd_ro, mtemp);
1970 ipstat.ips_redirectsent++;
1973 ipstat.ips_cantforward++;
1980 * Errors that do not require generating ICMP message
1985 * A router should not generate ICMP_SOURCEQUENCH as
1986 * required in RFC1812 Requirements for IP Version 4 Routers.
1987 * Source quench could be a big problem under DoS attacks,
1988 * or if the underlying interface is rate-limited.
1989 * Those who need source quench packets may re-enable them
1990 * via the net.inet.ip.sendsourcequench sysctl.
1992 if (!ip_sendsourcequench)
1996 case EACCES: /* ipfw denied packet */
2000 KASSERT((mtemp->m_flags & M_EXT) == 0 &&
2001 mtemp->m_data == mtemp->m_pktdat,
2002 ("ip_forward invalid mtemp2"));
2003 mcopy = m_copym(mtemp, 0, mtemp->m_len, MB_DONTWAIT);
2008 * Send ICMP message.
2011 case 0: /* forwarded, but need redirect */
2012 /* type, code set above */
2015 case ENETUNREACH: /* shouldn't happen, checked above */
2020 type = ICMP_UNREACH;
2021 code = ICMP_UNREACH_HOST;
2025 type = ICMP_UNREACH;
2026 code = ICMP_UNREACH_NEEDFRAG;
2029 * If the packet is routed over IPsec tunnel, tell the
2030 * originator the tunnel MTU.
2031 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2034 if (fwd_ro.ro_rt != NULL) {
2035 struct secpolicy *sp = NULL;
2040 sp = ipsec4_getpolicybyaddr(mcopy,
2046 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2048 /* count IPsec header size */
2049 ipsechdr = ipsec4_hdrsiz(mcopy,
2054 * find the correct route for outer IPv4
2055 * header, compute tunnel MTU.
2058 if (sp->req != NULL && sp->req->sav != NULL &&
2059 sp->req->sav->sah != NULL) {
2060 ro = &sp->req->sav->sah->sa_route;
2061 if (ro->ro_rt != NULL &&
2062 ro->ro_rt->rt_ifp != NULL) {
2064 ro->ro_rt->rt_ifp->if_mtu;
2065 destmtu -= ipsechdr;
2074 * If the packet is routed over IPsec tunnel, tell the
2075 * originator the tunnel MTU.
2076 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2079 if (fwd_ro.ro_rt != NULL) {
2080 struct secpolicy *sp = NULL;
2085 sp = ipsec_getpolicybyaddr(mcopy,
2091 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2093 /* count IPsec header size */
2094 ipsechdr = ipsec4_hdrsiz(mcopy,
2099 * find the correct route for outer IPv4
2100 * header, compute tunnel MTU.
2103 if (sp->req != NULL &&
2104 sp->req->sav != NULL &&
2105 sp->req->sav->sah != NULL) {
2106 ro = &sp->req->sav->sah->sa_route;
2107 if (ro->ro_rt != NULL &&
2108 ro->ro_rt->rt_ifp != NULL) {
2110 ro->ro_rt->rt_ifp->if_mtu;
2111 destmtu -= ipsechdr;
2118 #else /* !IPSEC && !FAST_IPSEC */
2119 if (fwd_ro.ro_rt != NULL)
2120 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2122 ipstat.ips_cantfrag++;
2126 type = ICMP_SOURCEQUENCH;
2130 case EACCES: /* ipfw denied packet */
2131 panic("ip_forward EACCES should not reach");
2133 icmp_error(mcopy, type, code, dest, destmtu);
2136 m_tag_delete_chain(mtemp);
2137 if (fwd_ro.ro_rt != NULL)
2138 RTFREE(fwd_ro.ro_rt);
2142 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
2145 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
2149 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
2150 SCM_TIMESTAMP, SOL_SOCKET);
2152 mp = &(*mp)->m_next;
2154 if (inp->inp_flags & INP_RECVDSTADDR) {
2155 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
2156 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2158 mp = &(*mp)->m_next;
2160 if (inp->inp_flags & INP_RECVTTL) {
2161 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
2162 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
2164 mp = &(*mp)->m_next;
2168 * Moving these out of udp_input() made them even more broken
2169 * than they already were.
2171 /* options were tossed already */
2172 if (inp->inp_flags & INP_RECVOPTS) {
2173 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
2174 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
2176 mp = &(*mp)->m_next;
2178 /* ip_srcroute doesn't do what we want here, need to fix */
2179 if (inp->inp_flags & INP_RECVRETOPTS) {
2180 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
2181 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
2183 mp = &(*mp)->m_next;
2186 if (inp->inp_flags & INP_RECVIF) {
2189 struct sockaddr_dl sdl;
2192 struct sockaddr_dl *sdp;
2193 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
2195 if (((ifp = m->m_pkthdr.rcvif)) &&
2196 ((ifp->if_index != 0) && (ifp->if_index <= if_index))) {
2197 sdp = IF_LLSOCKADDR(ifp);
2199 * Change our mind and don't try copy.
2201 if ((sdp->sdl_family != AF_LINK) ||
2202 (sdp->sdl_len > sizeof(sdlbuf))) {
2205 bcopy(sdp, sdl2, sdp->sdl_len);
2209 offsetof(struct sockaddr_dl, sdl_data[0]);
2210 sdl2->sdl_family = AF_LINK;
2211 sdl2->sdl_index = 0;
2212 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2214 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2215 IP_RECVIF, IPPROTO_IP);
2217 mp = &(*mp)->m_next;
2222 * XXX these routines are called from the upper part of the kernel.
2224 * They could also be moved to ip_mroute.c, since all the RSVP
2225 * handling is done there already.
2228 ip_rsvp_init(struct socket *so)
2230 if (so->so_type != SOCK_RAW ||
2231 so->so_proto->pr_protocol != IPPROTO_RSVP)
2234 if (ip_rsvpd != NULL)
2239 * This may seem silly, but we need to be sure we don't over-increment
2240 * the RSVP counter, in case something slips up.
2255 * This may seem silly, but we need to be sure we don't over-decrement
2256 * the RSVP counter, in case something slips up.
2266 rsvp_input(struct mbuf **mp, int *offp, int proto)
2268 struct mbuf *m = *mp;
2272 if (rsvp_input_p) { /* call the real one if loaded */
2274 rsvp_input_p(mp, offp, proto);
2275 return(IPPROTO_DONE);
2278 /* Can still get packets with rsvp_on = 0 if there is a local member
2279 * of the group to which the RSVP packet is addressed. But in this
2280 * case we want to throw the packet away.
2285 return(IPPROTO_DONE);
2288 if (ip_rsvpd != NULL) {
2290 rip_input(mp, offp, proto);
2291 return(IPPROTO_DONE);
2293 /* Drop the packet */
2295 return(IPPROTO_DONE);