2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
5 * This code is derived from software contributed to The DragonFly Project
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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12 * notice, this list of conditions and the following disclaimer.
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15 * documentation and/or other materials provided with the distribution.
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17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
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63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
67 * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.52 2003/03/07 07:01:28 silby Exp $
72 #include "opt_bootp.h"
74 #include "opt_ipdivert.h"
75 #include "opt_ipstealth.h"
76 #include "opt_ipsec.h"
79 #include <sys/param.h>
80 #include <sys/systm.h>
82 #include <sys/malloc.h>
83 #include <sys/mpipe.h>
84 #include <sys/domain.h>
85 #include <sys/protosw.h>
86 #include <sys/socket.h>
88 #include <sys/globaldata.h>
89 #include <sys/thread.h>
90 #include <sys/kernel.h>
91 #include <sys/syslog.h>
92 #include <sys/sysctl.h>
93 #include <sys/in_cksum.h>
96 #include <sys/mplock2.h>
98 #include <machine/stdarg.h>
101 #include <net/if_types.h>
102 #include <net/if_var.h>
103 #include <net/if_dl.h>
104 #include <net/pfil.h>
105 #include <net/route.h>
106 #include <net/netisr.h>
108 #include <netinet/in.h>
109 #include <netinet/in_systm.h>
110 #include <netinet/in_var.h>
111 #include <netinet/ip.h>
112 #include <netinet/in_pcb.h>
113 #include <netinet/ip_var.h>
114 #include <netinet/ip_icmp.h>
115 #include <netinet/ip_divert.h>
116 #include <netinet/ip_flow.h>
118 #include <sys/thread2.h>
119 #include <sys/msgport2.h>
120 #include <net/netmsg2.h>
122 #include <sys/socketvar.h>
124 #include <net/ipfw/ip_fw.h>
125 #include <net/dummynet/ip_dummynet.h>
128 #include <netinet6/ipsec.h>
129 #include <netproto/key/key.h>
133 #include <netproto/ipsec/ipsec.h>
134 #include <netproto/ipsec/key.h>
138 static int ip_rsvp_on;
139 struct socket *ip_rsvpd;
141 int ipforwarding = 0;
142 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
143 &ipforwarding, 0, "Enable IP forwarding between interfaces");
145 static int ipsendredirects = 1; /* XXX */
146 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
147 &ipsendredirects, 0, "Enable sending IP redirects");
149 int ip_defttl = IPDEFTTL;
150 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
151 &ip_defttl, 0, "Maximum TTL on IP packets");
153 static int ip_dosourceroute = 0;
154 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
155 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
157 static int ip_acceptsourceroute = 0;
158 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
159 CTLFLAG_RW, &ip_acceptsourceroute, 0,
160 "Enable accepting source routed IP packets");
162 static int ip_keepfaith = 0;
163 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
165 "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
167 static int nipq = 0; /* total # of reass queues */
169 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
171 "Maximum number of IPv4 fragment reassembly queue entries");
173 static int maxfragsperpacket;
174 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
175 &maxfragsperpacket, 0,
176 "Maximum number of IPv4 fragments allowed per packet");
178 static int ip_sendsourcequench = 0;
179 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
180 &ip_sendsourcequench, 0,
181 "Enable the transmission of source quench packets");
183 int ip_do_randomid = 1;
184 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
186 "Assign random ip_id values");
188 * XXX - Setting ip_checkinterface mostly implements the receive side of
189 * the Strong ES model described in RFC 1122, but since the routing table
190 * and transmit implementation do not implement the Strong ES model,
191 * setting this to 1 results in an odd hybrid.
193 * XXX - ip_checkinterface currently must be disabled if you use ipnat
194 * to translate the destination address to another local interface.
196 * XXX - ip_checkinterface must be disabled if you add IP aliases
197 * to the loopback interface instead of the interface where the
198 * packets for those addresses are received.
200 static int ip_checkinterface = 0;
201 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
202 &ip_checkinterface, 0, "Verify packet arrives on correct interface");
204 static u_long ip_hash_count = 0;
205 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, hash_count, CTLFLAG_RD,
206 &ip_hash_count, 0, "Number of packets hashed by IP");
209 static u_long ip_rehash_count = 0;
210 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, rehash_count, CTLFLAG_RD,
211 &ip_rehash_count, 0, "Number of packets rehashed by IP");
213 static u_long ip_dispatch_fast = 0;
214 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_fast_count, CTLFLAG_RD,
215 &ip_dispatch_fast, 0, "Number of packets handled on current CPU");
217 static u_long ip_dispatch_slow = 0;
218 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_slow_count, CTLFLAG_RD,
219 &ip_dispatch_slow, 0, "Number of packets messaged to another CPU");
222 static struct lwkt_token ipq_token = LWKT_TOKEN_INITIALIZER(ipq_token);
225 static int ipprintfs = 0;
228 extern struct domain inetdomain;
229 extern struct protosw inetsw[];
230 u_char ip_protox[IPPROTO_MAX];
231 struct in_ifaddrhead in_ifaddrheads[MAXCPU]; /* first inet address */
232 struct in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU];
233 /* inet addr hash table */
234 u_long in_ifaddrhmask; /* mask for hash table */
236 static struct mbuf *ipforward_mtemp[MAXCPU];
238 struct ip_stats ipstats_percpu[MAXCPU] __cachealign;
241 sysctl_ipstats(SYSCTL_HANDLER_ARGS)
245 for (cpu = 0; cpu < ncpus; ++cpu) {
246 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu],
247 sizeof(struct ip_stats))))
249 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu],
250 sizeof(struct ip_stats))))
256 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
257 0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics");
259 /* Packet reassembly stuff */
260 #define IPREASS_NHASH_LOG2 6
261 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
262 #define IPREASS_HMASK (IPREASS_NHASH - 1)
263 #define IPREASS_HASH(x,y) \
264 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
266 static TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH];
269 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
270 &ip_mtu, 0, "Default MTU");
274 static int ipstealth = 0;
275 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, "");
277 static const int ipstealth = 0;
280 struct mbuf *(*ip_divert_p)(struct mbuf *, int, int);
282 struct pfil_head inet_pfil_hook;
285 * struct ip_srcrt_opt is used to store packet state while it travels
288 * XXX Note that the code even makes assumptions on the size and
289 * alignment of fields inside struct ip_srcrt so e.g. adding some
290 * fields will break the code. This needs to be fixed.
292 * We need to save the IP options in case a protocol wants to respond
293 * to an incoming packet over the same route if the packet got here
294 * using IP source routing. This allows connection establishment and
295 * maintenance when the remote end is on a network that is not known
299 struct in_addr dst; /* final destination */
300 char nop; /* one NOP to align */
301 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
302 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
305 struct ip_srcrt_opt {
307 struct ip_srcrt ip_srcrt;
310 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management");
311 static struct malloc_pipe ipq_mpipe;
313 static void save_rte(struct mbuf *, u_char *, struct in_addr);
314 static int ip_dooptions(struct mbuf *m, int, struct sockaddr_in *);
315 static void ip_freef(struct ipqhead *, struct ipq *);
316 static void ip_input_handler(netmsg_t);
319 * IP initialization: fill in IP protocol switch table.
320 * All protocols not implemented in kernel go to raw IP protocol handler.
330 * Make sure we can handle a reasonable number of fragments but
331 * cap it at 4000 (XXX).
333 mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq),
334 IFQ_MAXLEN, 4000, 0, NULL, NULL, NULL);
335 for (i = 0; i < ncpus; ++i) {
336 TAILQ_INIT(&in_ifaddrheads[i]);
337 in_ifaddrhashtbls[i] =
338 hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
340 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
343 for (i = 0; i < IPPROTO_MAX; i++)
344 ip_protox[i] = pr - inetsw;
345 for (pr = inetdomain.dom_protosw;
346 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
347 if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol) {
348 if (pr->pr_protocol != IPPROTO_RAW)
349 ip_protox[pr->pr_protocol] = pr - inetsw;
353 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
354 inet_pfil_hook.ph_af = AF_INET;
355 if ((i = pfil_head_register(&inet_pfil_hook)) != 0) {
356 kprintf("%s: WARNING: unable to register pfil hook, "
357 "error %d\n", __func__, i);
360 for (i = 0; i < IPREASS_NHASH; i++)
363 maxnipq = nmbclusters / 32;
364 maxfragsperpacket = 16;
366 ip_id = time_second & 0xffff;
368 for (cpu = 0; cpu < ncpus; ++cpu) {
370 * Initialize IP statistics counters for each CPU.
372 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats));
375 * Preallocate mbuf template for forwarding
377 MGETHDR(ipforward_mtemp[cpu], MB_WAIT, MT_DATA);
380 netisr_register(NETISR_IP, ip_input_handler, ip_cpufn_in);
381 netisr_register_hashcheck(NETISR_IP, ip_hashcheck);
384 /* Do transport protocol processing. */
386 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip)
388 const struct protosw *pr = &inetsw[ip_protox[ip->ip_p]];
391 * Switch out to protocol's input routine.
394 pr->pr_input(&m, &hlen, ip->ip_p);
399 transport_processing_handler(netmsg_t msg)
401 struct netmsg_packet *pmsg = &msg->packet;
405 ip = mtod(pmsg->nm_packet, struct ip *);
406 hlen = pmsg->base.lmsg.u.ms_result;
408 transport_processing_oncpu(pmsg->nm_packet, hlen, ip);
409 /* msg was embedded in the mbuf, do not reply! */
413 ip_input_handler(netmsg_t msg)
415 ip_input(msg->packet.nm_packet);
416 /* msg was embedded in the mbuf, do not reply! */
420 * IP input routine. Checksum and byte swap header. If fragmented
421 * try to reassemble. Process options. Pass to next level.
424 ip_input(struct mbuf *m)
427 struct in_ifaddr *ia = NULL;
428 struct in_ifaddr_container *iac;
431 struct in_addr pkt_dst;
432 boolean_t using_srcrt = FALSE; /* forward (by PFIL_HOOKS) */
433 struct in_addr odst; /* original dst address(NAT) */
435 struct sockaddr_in *next_hop = NULL;
438 struct tdb_ident *tdbi;
439 struct secpolicy *sp;
446 * This routine is called from numerous places which may not have
447 * characterized the packet.
449 if ((m->m_flags & M_HASH) == 0) {
450 atomic_add_long(&ip_hash_count, 1);
451 ip_cpufn(&m, 0, IP_MPORT_IN);
454 KKASSERT(m->m_flags & M_HASH);
456 ip = mtod(m, struct ip *);
459 * Pull out certain tags
461 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
463 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
464 KKASSERT(mtag != NULL);
465 next_hop = m_tag_data(mtag);
468 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
469 /* dummynet already filtered us */
470 ip = mtod(m, struct ip *);
471 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
477 /* length checks already done in ip_cpufn() */
478 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf"));
480 if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
481 ipstat.ips_badvers++;
485 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
486 /* length checks already done in ip_cpufn() */
487 KASSERT(hlen >= sizeof(struct ip), ("IP header len too small"));
488 KASSERT(m->m_len >= hlen, ("complete IP header not in one mbuf"));
490 /* 127/8 must not appear on wire - RFC1122 */
491 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
492 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
493 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) {
494 ipstat.ips_badaddr++;
499 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
500 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
502 if (hlen == sizeof(struct ip))
503 sum = in_cksum_hdr(ip);
505 sum = in_cksum(m, hlen);
513 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
514 /* packet is dropped by traffic conditioner */
519 * Convert fields to host representation.
521 ip->ip_len = ntohs(ip->ip_len);
522 ip->ip_off = ntohs(ip->ip_off);
524 /* length checks already done in ip_cpufn() */
525 KASSERT(ip->ip_len >= hlen, ("total length less then header length"));
526 KASSERT(m->m_pkthdr.len >= ip->ip_len, ("mbuf too short"));
529 * Trim mbufs if longer than the IP header would have us expect.
531 if (m->m_pkthdr.len > ip->ip_len) {
532 if (m->m_len == m->m_pkthdr.len) {
533 m->m_len = ip->ip_len;
534 m->m_pkthdr.len = ip->ip_len;
536 m_adj(m, ip->ip_len - m->m_pkthdr.len);
539 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
541 * Bypass packet filtering for packets from a tunnel (gif).
543 if (ipsec_gethist(m, NULL))
549 * Right now when no processing on packet has done
550 * and it is still fresh out of network we do our black
552 * - Firewall: deny/allow/divert
553 * - Xlate: translate packet's addr/port (NAT).
554 * - Pipe: pass pkt through dummynet.
555 * - Wrap: fake packet's addr/port <unimpl.>
556 * - Encapsulate: put it in another IP and send out. <unimp.>
561 * If we've been forwarded from the output side, then
562 * skip the firewall a second time
564 if (next_hop != NULL)
568 if (!pfil_has_hooks(&inet_pfil_hook)) {
569 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
571 * Strip dummynet tags from stranded packets
573 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
574 KKASSERT(mtag != NULL);
575 m_tag_delete(m, mtag);
576 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
582 * Run through list of hooks for input packets.
584 * NOTE! If the packet is rewritten pf/ipfw/whoever must
588 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN))
590 if (m == NULL) /* consumed by filter */
592 ip = mtod(m, struct ip *);
593 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
594 using_srcrt = (odst.s_addr != ip->ip_dst.s_addr);
596 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
597 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
598 KKASSERT(mtag != NULL);
599 next_hop = m_tag_data(mtag);
601 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
605 if (m->m_pkthdr.fw_flags & FW_MBUF_REDISPATCH) {
606 m->m_pkthdr.fw_flags &= ~FW_MBUF_REDISPATCH;
610 * Process options and, if not destined for us,
611 * ship it on. ip_dooptions returns 1 when an
612 * error was detected (causing an icmp message
613 * to be sent and the original packet to be freed).
615 if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, next_hop))
618 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
619 * matter if it is destined to another node, or whether it is
620 * a multicast one, RSVP wants it! and prevents it from being forwarded
621 * anywhere else. Also checks if the rsvp daemon is running before
622 * grabbing the packet.
624 if (rsvp_on && ip->ip_p == IPPROTO_RSVP)
628 * Check our list of addresses, to see if the packet is for us.
629 * If we don't have any addresses, assume any unicast packet
630 * we receive might be for us (and let the upper layers deal
633 if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) &&
634 !(m->m_flags & (M_MCAST | M_BCAST)))
638 * Cache the destination address of the packet; this may be
639 * changed by use of 'ipfw fwd'.
641 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
644 * Enable a consistency check between the destination address
645 * and the arrival interface for a unicast packet (the RFC 1122
646 * strong ES model) if IP forwarding is disabled and the packet
647 * is not locally generated and the packet is not subject to
650 * XXX - Checking also should be disabled if the destination
651 * address is ipnat'ed to a different interface.
653 * XXX - Checking is incompatible with IP aliases added
654 * to the loopback interface instead of the interface where
655 * the packets are received.
657 checkif = ip_checkinterface &&
659 m->m_pkthdr.rcvif != NULL &&
660 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) &&
664 * Check for exact addresses in the hash bucket.
666 LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
670 * If the address matches, verify that the packet
671 * arrived via the correct interface if checking is
674 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
675 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
681 * Check for broadcast addresses.
683 * Only accept broadcast packets that arrive via the matching
684 * interface. Reception of forwarded directed broadcasts would
685 * be handled via ip_forward() and ether_output() with the loopback
686 * into the stack for SIMPLEX interfaces handled by ether_output().
688 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
689 struct ifaddr_container *ifac;
691 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid],
693 struct ifaddr *ifa = ifac->ifa;
695 if (ifa->ifa_addr == NULL) /* shutdown/startup race */
697 if (ifa->ifa_addr->sa_family != AF_INET)
700 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
703 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
706 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
711 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
712 struct in_multi *inm;
714 /* XXX Multicast is not MPSAFE yet */
717 if (ip_mrouter != NULL) {
719 * If we are acting as a multicast router, all
720 * incoming multicast packets are passed to the
721 * kernel-level multicast forwarding function.
722 * The packet is returned (relatively) intact; if
723 * ip_mforward() returns a non-zero value, the packet
724 * must be discarded, else it may be accepted below.
726 if (ip_mforward != NULL &&
727 ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) {
729 ipstat.ips_cantforward++;
735 * The process-level routing daemon needs to receive
736 * all multicast IGMP packets, whether or not this
737 * host belongs to their destination groups.
739 if (ip->ip_p == IPPROTO_IGMP) {
743 ipstat.ips_forward++;
746 * See if we belong to the destination multicast group on the
749 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
752 ipstat.ips_notmember++;
760 if (ip->ip_dst.s_addr == INADDR_BROADCAST)
762 if (ip->ip_dst.s_addr == INADDR_ANY)
766 * FAITH(Firewall Aided Internet Translator)
768 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
770 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
778 * Not for us; forward if possible and desirable.
781 ipstat.ips_cantforward++;
786 * Enforce inbound IPsec SPD.
788 if (ipsec4_in_reject(m, NULL)) {
789 ipsecstat.in_polvio++;
794 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
797 tdbi = (struct tdb_ident *)m_tag_data(mtag);
798 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
800 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
801 IP_FORWARDING, &error);
803 if (sp == NULL) { /* NB: can happen if error */
805 /*XXX error stat???*/
806 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
811 * Check security policy against packet attributes.
813 error = ipsec_in_reject(sp, m);
817 ipstat.ips_cantforward++;
821 ip_forward(m, using_srcrt, next_hop);
828 * IPSTEALTH: Process non-routing options only
829 * if the packet is destined for us.
832 hlen > sizeof(struct ip) &&
833 ip_dooptions(m, 1, next_hop))
836 /* Count the packet in the ip address stats */
838 IFA_STAT_INC(&ia->ia_ifa, ipackets, 1);
839 IFA_STAT_INC(&ia->ia_ifa, ibytes, m->m_pkthdr.len);
843 * If offset or IP_MF are set, must reassemble.
844 * Otherwise, nothing need be done.
845 * (We could look in the reassembly queue to see
846 * if the packet was previously fragmented,
847 * but it's not worth the time; just let them time out.)
849 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
851 * Attempt reassembly; if it succeeds, proceed. ip_reass()
852 * will return a different mbuf.
854 * NOTE: ip_reass() returns m with M_HASH cleared to force
855 * us to recharacterize the packet.
860 ip = mtod(m, struct ip *);
862 /* Get the header length of the reassembled packet */
863 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
870 * enforce IPsec policy checking if we are seeing last header.
871 * note that we do not visit this with protocols with pcb layer
872 * code - like udp/tcp/raw ip.
874 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) &&
875 ipsec4_in_reject(m, NULL)) {
876 ipsecstat.in_polvio++;
882 * enforce IPsec policy checking if we are seeing last header.
883 * note that we do not visit this with protocols with pcb layer
884 * code - like udp/tcp/raw ip.
886 if (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) {
888 * Check if the packet has already had IPsec processing
889 * done. If so, then just pass it along. This tag gets
890 * set during AH, ESP, etc. input handling, before the
891 * packet is returned to the ip input queue for delivery.
893 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
896 tdbi = (struct tdb_ident *)m_tag_data(mtag);
897 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
899 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
900 IP_FORWARDING, &error);
904 * Check security policy against packet attributes.
906 error = ipsec_in_reject(sp, m);
909 /* XXX error stat??? */
911 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
918 #endif /* FAST_IPSEC */
921 * We must forward the packet to the correct protocol thread if
922 * we are not already in it.
924 * NOTE: ip_len is now in host form. ip_len is not adjusted
925 * further for protocol processing, instead we pass hlen
926 * to the protosw and let it deal with it.
928 ipstat.ips_delivered++;
930 if ((m->m_flags & M_HASH) == 0) {
932 atomic_add_long(&ip_rehash_count, 1);
934 ip->ip_len = htons(ip->ip_len + hlen);
935 ip->ip_off = htons(ip->ip_off);
937 ip_cpufn(&m, 0, IP_MPORT_IN);
941 ip = mtod(m, struct ip *);
942 ip->ip_len = ntohs(ip->ip_len) - hlen;
943 ip->ip_off = ntohs(ip->ip_off);
944 KKASSERT(m->m_flags & M_HASH);
946 port = netisr_portfn(m->m_pkthdr.hash);
948 if (port != &curthread->td_msgport) {
949 struct netmsg_packet *pmsg;
952 atomic_add_long(&ip_dispatch_slow, 1);
955 pmsg = &m->m_hdr.mh_netmsg;
956 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport,
957 0, transport_processing_handler);
959 pmsg->base.lmsg.u.ms_result = hlen;
960 lwkt_sendmsg(port, &pmsg->base.lmsg);
963 atomic_add_long(&ip_dispatch_fast, 1);
965 transport_processing_oncpu(m, hlen, ip);
974 * Take incoming datagram fragment and try to reassemble it into
975 * whole datagram. If a chain for reassembly of this datagram already
976 * exists, then it is given as fp; otherwise have to make a chain.
979 ip_reass(struct mbuf *m)
981 struct ip *ip = mtod(m, struct ip *);
982 struct mbuf *p = NULL, *q, *nq;
984 struct ipq *fp = NULL;
985 struct ipqhead *head;
986 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
990 /* If maxnipq is 0, never accept fragments. */
992 ipstat.ips_fragments++;
993 ipstat.ips_fragdropped++;
998 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
1000 * Look for queue of fragments of this datagram.
1002 lwkt_gettoken(&ipq_token);
1004 TAILQ_FOREACH(fp, head, ipq_list) {
1005 if (ip->ip_id == fp->ipq_id &&
1006 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
1007 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
1008 ip->ip_p == fp->ipq_p)
1015 * Enforce upper bound on number of fragmented packets
1016 * for which we attempt reassembly;
1017 * If maxnipq is -1, accept all fragments without limitation.
1019 if (nipq > maxnipq && maxnipq > 0) {
1021 * drop something from the tail of the current queue
1022 * before proceeding further
1024 struct ipq *q = TAILQ_LAST(head, ipqhead);
1027 * The current queue is empty,
1028 * so drop from one of the others.
1030 for (i = 0; i < IPREASS_NHASH; i++) {
1031 struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead);
1033 ipstat.ips_fragtimeout += r->ipq_nfrags;
1034 ip_freef(&ipq[i], r);
1039 ipstat.ips_fragtimeout += q->ipq_nfrags;
1045 * Adjust ip_len to not reflect header,
1046 * convert offset of this to bytes.
1049 if (ip->ip_off & IP_MF) {
1051 * Make sure that fragments have a data length
1052 * that's a non-zero multiple of 8 bytes.
1054 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1055 ipstat.ips_toosmall++; /* XXX */
1059 m->m_flags |= M_FRAG;
1061 m->m_flags &= ~M_FRAG;
1065 ipstat.ips_fragments++;
1066 m->m_pkthdr.header = ip;
1069 * If the hardware has not done csum over this fragment
1070 * then csum_data is not valid at all.
1072 if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID))
1073 == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) {
1074 m->m_pkthdr.csum_data = 0;
1075 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
1079 * Presence of header sizes in mbufs
1080 * would confuse code below.
1086 * If first fragment to arrive, create a reassembly queue.
1089 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL)
1091 TAILQ_INSERT_HEAD(head, fp, ipq_list);
1094 fp->ipq_ttl = IPFRAGTTL;
1095 fp->ipq_p = ip->ip_p;
1096 fp->ipq_id = ip->ip_id;
1097 fp->ipq_src = ip->ip_src;
1098 fp->ipq_dst = ip->ip_dst;
1100 m->m_nextpkt = NULL;
1106 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1109 * Find a segment which begins after this one does.
1111 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1112 if (GETIP(q)->ip_off > ip->ip_off)
1117 * If there is a preceding segment, it may provide some of
1118 * our data already. If so, drop the data from the incoming
1119 * segment. If it provides all of our data, drop us, otherwise
1120 * stick new segment in the proper place.
1122 * If some of the data is dropped from the the preceding
1123 * segment, then it's checksum is invalidated.
1126 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1128 if (i >= ip->ip_len)
1131 m->m_pkthdr.csum_flags = 0;
1135 m->m_nextpkt = p->m_nextpkt;
1138 m->m_nextpkt = fp->ipq_frags;
1143 * While we overlap succeeding segments trim them or,
1144 * if they are completely covered, dequeue them.
1146 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1148 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1149 if (i < GETIP(q)->ip_len) {
1150 GETIP(q)->ip_len -= i;
1151 GETIP(q)->ip_off += i;
1153 q->m_pkthdr.csum_flags = 0;
1158 ipstat.ips_fragdropped++;
1160 q->m_nextpkt = NULL;
1166 * Check for complete reassembly and perform frag per packet
1169 * Frag limiting is performed here so that the nth frag has
1170 * a chance to complete the packet before we drop the packet.
1171 * As a result, n+1 frags are actually allowed per packet, but
1172 * only n will ever be stored. (n = maxfragsperpacket.)
1176 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1177 if (GETIP(q)->ip_off != next) {
1178 if (fp->ipq_nfrags > maxfragsperpacket) {
1179 ipstat.ips_fragdropped += fp->ipq_nfrags;
1184 next += GETIP(q)->ip_len;
1186 /* Make sure the last packet didn't have the IP_MF flag */
1187 if (p->m_flags & M_FRAG) {
1188 if (fp->ipq_nfrags > maxfragsperpacket) {
1189 ipstat.ips_fragdropped += fp->ipq_nfrags;
1196 * Reassembly is complete. Make sure the packet is a sane size.
1200 if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
1201 ipstat.ips_toolong++;
1202 ipstat.ips_fragdropped += fp->ipq_nfrags;
1208 * Concatenate fragments.
1215 q->m_nextpkt = NULL;
1216 for (q = nq; q != NULL; q = nq) {
1218 q->m_nextpkt = NULL;
1219 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1220 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1225 * Clean up the 1's complement checksum. Carry over 16 bits must
1226 * be added back. This assumes no more then 65535 packet fragments
1227 * were reassembled. A second carry can also occur (but not a third).
1229 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) +
1230 (m->m_pkthdr.csum_data >> 16);
1231 if (m->m_pkthdr.csum_data > 0xFFFF)
1232 m->m_pkthdr.csum_data -= 0xFFFF;
1235 * Create header for new ip packet by
1236 * modifying header of first packet;
1237 * dequeue and discard fragment reassembly header.
1238 * Make header visible.
1241 ip->ip_src = fp->ipq_src;
1242 ip->ip_dst = fp->ipq_dst;
1243 TAILQ_REMOVE(head, fp, ipq_list);
1245 mpipe_free(&ipq_mpipe, fp);
1246 m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
1247 m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
1248 /* some debugging cruft by sklower, below, will go away soon */
1249 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1252 for (n = m; n; n = n->m_next)
1254 m->m_pkthdr.len = plen;
1258 * Reassembly complete, return the next protocol.
1260 * Be sure to clear M_HASH to force the packet
1261 * to be re-characterized.
1263 * Clear M_FRAG, we are no longer a fragment.
1265 m->m_flags &= ~(M_HASH | M_FRAG);
1267 ipstat.ips_reassembled++;
1268 lwkt_reltoken(&ipq_token);
1272 ipstat.ips_fragdropped++;
1277 lwkt_reltoken(&ipq_token);
1284 * Free a fragment reassembly header and all
1285 * associated datagrams.
1287 * Called with ipq_token held.
1290 ip_freef(struct ipqhead *fhp, struct ipq *fp)
1295 * Remove first to protect against blocking
1297 TAILQ_REMOVE(fhp, fp, ipq_list);
1300 * Clean out at our leisure
1302 while (fp->ipq_frags) {
1304 fp->ipq_frags = q->m_nextpkt;
1305 q->m_nextpkt = NULL;
1308 mpipe_free(&ipq_mpipe, fp);
1313 * IP timer processing;
1314 * if a timer expires on a reassembly
1315 * queue, discard it.
1320 struct ipq *fp, *fp_temp;
1321 struct ipqhead *head;
1324 lwkt_gettoken(&ipq_token);
1325 for (i = 0; i < IPREASS_NHASH; i++) {
1327 TAILQ_FOREACH_MUTABLE(fp, head, ipq_list, fp_temp) {
1328 if (--fp->ipq_ttl == 0) {
1329 ipstat.ips_fragtimeout += fp->ipq_nfrags;
1335 * If we are over the maximum number of fragments
1336 * (due to the limit being lowered), drain off
1337 * enough to get down to the new limit.
1339 if (maxnipq >= 0 && nipq > maxnipq) {
1340 for (i = 0; i < IPREASS_NHASH; i++) {
1342 while (nipq > maxnipq && !TAILQ_EMPTY(head)) {
1343 ipstat.ips_fragdropped +=
1344 TAILQ_FIRST(head)->ipq_nfrags;
1345 ip_freef(head, TAILQ_FIRST(head));
1349 lwkt_reltoken(&ipq_token);
1354 * Drain off all datagram fragments.
1359 struct ipqhead *head;
1362 lwkt_gettoken(&ipq_token);
1363 for (i = 0; i < IPREASS_NHASH; i++) {
1365 while (!TAILQ_EMPTY(head)) {
1366 ipstat.ips_fragdropped += TAILQ_FIRST(head)->ipq_nfrags;
1367 ip_freef(head, TAILQ_FIRST(head));
1370 lwkt_reltoken(&ipq_token);
1375 * Do option processing on a datagram,
1376 * possibly discarding it if bad options are encountered,
1377 * or forwarding it if source-routed.
1378 * The pass argument is used when operating in the IPSTEALTH
1379 * mode to tell what options to process:
1380 * [LS]SRR (pass 0) or the others (pass 1).
1381 * The reason for as many as two passes is that when doing IPSTEALTH,
1382 * non-routing options should be processed only if the packet is for us.
1383 * Returns 1 if packet has been forwarded/freed,
1384 * 0 if the packet should be processed further.
1387 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
1389 struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET };
1390 struct ip *ip = mtod(m, struct ip *);
1392 struct in_ifaddr *ia;
1393 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB;
1394 boolean_t forward = FALSE;
1395 struct in_addr *sin, dst;
1399 cp = (u_char *)(ip + 1);
1400 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1401 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1402 opt = cp[IPOPT_OPTVAL];
1403 if (opt == IPOPT_EOL)
1405 if (opt == IPOPT_NOP)
1408 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1409 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1412 optlen = cp[IPOPT_OLEN];
1413 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1414 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1424 * Source routing with record.
1425 * Find interface with current destination address.
1426 * If none on this machine then drop if strictly routed,
1427 * or do nothing if loosely routed.
1428 * Record interface address and bring up next address
1429 * component. If strictly routed make sure next
1430 * address is on directly accessible net.
1434 if (ipstealth && pass > 0)
1436 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1437 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1440 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1441 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1444 ipaddr.sin_addr = ip->ip_dst;
1445 ia = (struct in_ifaddr *)
1446 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1448 if (opt == IPOPT_SSRR) {
1449 type = ICMP_UNREACH;
1450 code = ICMP_UNREACH_SRCFAIL;
1453 if (!ip_dosourceroute)
1454 goto nosourcerouting;
1456 * Loose routing, and not at next destination
1457 * yet; nothing to do except forward.
1461 off--; /* 0 origin */
1462 if (off > optlen - (int)sizeof(struct in_addr)) {
1464 * End of source route. Should be for us.
1466 if (!ip_acceptsourceroute)
1467 goto nosourcerouting;
1468 save_rte(m, cp, ip->ip_src);
1473 if (!ip_dosourceroute) {
1475 char buf[sizeof "aaa.bbb.ccc.ddd"];
1478 * Acting as a router, so generate ICMP
1481 strcpy(buf, inet_ntoa(ip->ip_dst));
1483 "attempted source route from %s to %s\n",
1484 inet_ntoa(ip->ip_src), buf);
1485 type = ICMP_UNREACH;
1486 code = ICMP_UNREACH_SRCFAIL;
1490 * Not acting as a router,
1494 ipstat.ips_cantforward++;
1501 * locate outgoing interface
1503 memcpy(&ipaddr.sin_addr, cp + off,
1504 sizeof ipaddr.sin_addr);
1506 if (opt == IPOPT_SSRR) {
1507 #define INA struct in_ifaddr *
1508 #define SA struct sockaddr *
1509 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr))
1511 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1513 ia = ip_rtaddr(ipaddr.sin_addr, NULL);
1516 type = ICMP_UNREACH;
1517 code = ICMP_UNREACH_SRCFAIL;
1520 ip->ip_dst = ipaddr.sin_addr;
1521 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1522 sizeof(struct in_addr));
1523 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1525 * Let ip_intr's mcast routing check handle mcast pkts
1527 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1531 if (ipstealth && pass == 0)
1533 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1534 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1537 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1538 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1542 * If no space remains, ignore.
1544 off--; /* 0 origin */
1545 if (off > optlen - (int)sizeof(struct in_addr))
1547 memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1548 sizeof ipaddr.sin_addr);
1550 * locate outgoing interface; if we're the destination,
1551 * use the incoming interface (should be same).
1553 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL &&
1554 (ia = ip_rtaddr(ipaddr.sin_addr, NULL)) == NULL) {
1555 type = ICMP_UNREACH;
1556 code = ICMP_UNREACH_HOST;
1559 memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1560 sizeof(struct in_addr));
1561 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1565 if (ipstealth && pass == 0)
1567 code = cp - (u_char *)ip;
1568 if (optlen < 4 || optlen > 40) {
1569 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1572 if ((off = cp[IPOPT_OFFSET]) < 5) {
1573 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1576 if (off > optlen - (int)sizeof(int32_t)) {
1577 cp[IPOPT_OFFSET + 1] += (1 << 4);
1578 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1579 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1584 off--; /* 0 origin */
1585 sin = (struct in_addr *)(cp + off);
1586 switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1588 case IPOPT_TS_TSONLY:
1591 case IPOPT_TS_TSANDADDR:
1592 if (off + sizeof(n_time) +
1593 sizeof(struct in_addr) > optlen) {
1594 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1597 ipaddr.sin_addr = dst;
1598 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1602 memcpy(sin, &IA_SIN(ia)->sin_addr,
1603 sizeof(struct in_addr));
1604 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1605 off += sizeof(struct in_addr);
1608 case IPOPT_TS_PRESPEC:
1609 if (off + sizeof(n_time) +
1610 sizeof(struct in_addr) > optlen) {
1611 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1614 memcpy(&ipaddr.sin_addr, sin,
1615 sizeof(struct in_addr));
1616 if (ifa_ifwithaddr((SA)&ipaddr) == NULL)
1618 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1619 off += sizeof(struct in_addr);
1623 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1627 memcpy(cp + off, &ntime, sizeof(n_time));
1628 cp[IPOPT_OFFSET] += sizeof(n_time);
1631 if (forward && ipforwarding) {
1632 ip_forward(m, TRUE, next_hop);
1637 icmp_error(m, type, code, 0, 0);
1638 ipstat.ips_badoptions++;
1643 * Given address of next destination (final or next hop),
1644 * return internet address info of interface to be used to get there.
1647 ip_rtaddr(struct in_addr dst, struct route *ro0)
1649 struct route sro, *ro;
1650 struct sockaddr_in *sin;
1651 struct in_ifaddr *ia;
1656 bzero(&sro, sizeof(sro));
1660 sin = (struct sockaddr_in *)&ro->ro_dst;
1662 if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) {
1663 if (ro->ro_rt != NULL) {
1667 sin->sin_family = AF_INET;
1668 sin->sin_len = sizeof *sin;
1669 sin->sin_addr = dst;
1670 rtalloc_ign(ro, RTF_PRCLONING);
1673 if (ro->ro_rt == NULL)
1676 ia = ifatoia(ro->ro_rt->rt_ifa);
1684 * Save incoming source route for use in replies,
1685 * to be picked up later by ip_srcroute if the receiver is interested.
1688 save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1691 struct ip_srcrt_opt *opt;
1694 mtag = m_tag_get(PACKET_TAG_IPSRCRT, sizeof(*opt), MB_DONTWAIT);
1697 opt = m_tag_data(mtag);
1699 olen = option[IPOPT_OLEN];
1702 kprintf("save_rte: olen %d\n", olen);
1704 if (olen > sizeof(opt->ip_srcrt) - (1 + sizeof(dst))) {
1708 bcopy(option, opt->ip_srcrt.srcopt, olen);
1709 opt->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1710 opt->ip_srcrt.dst = dst;
1711 m_tag_prepend(m, mtag);
1715 * Retrieve incoming source route for use in replies,
1716 * in the same form used by setsockopt.
1717 * The first hop is placed before the options, will be removed later.
1720 ip_srcroute(struct mbuf *m0)
1722 struct in_addr *p, *q;
1725 struct ip_srcrt_opt *opt;
1730 mtag = m_tag_find(m0, PACKET_TAG_IPSRCRT, NULL);
1733 opt = m_tag_data(mtag);
1735 if (opt->ip_nhops == 0)
1737 m = m_get(MB_DONTWAIT, MT_HEADER);
1741 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt))
1743 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1744 m->m_len = opt->ip_nhops * sizeof(struct in_addr) +
1745 sizeof(struct in_addr) + OPTSIZ;
1748 kprintf("ip_srcroute: nhops %d mlen %d",
1749 opt->ip_nhops, m->m_len);
1754 * First save first hop for return route
1756 p = &opt->ip_srcrt.route[opt->ip_nhops - 1];
1757 *(mtod(m, struct in_addr *)) = *p--;
1760 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1764 * Copy option fields and padding (nop) to mbuf.
1766 opt->ip_srcrt.nop = IPOPT_NOP;
1767 opt->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1768 memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &opt->ip_srcrt.nop,
1770 q = (struct in_addr *)(mtod(m, caddr_t) +
1771 sizeof(struct in_addr) + OPTSIZ);
1774 * Record return path as an IP source route,
1775 * reversing the path (pointers are now aligned).
1777 while (p >= opt->ip_srcrt.route) {
1780 kprintf(" %x", ntohl(q->s_addr));
1785 * Last hop goes to final destination.
1787 *q = opt->ip_srcrt.dst;
1788 m_tag_delete(m0, mtag);
1791 kprintf(" %x\n", ntohl(q->s_addr));
1797 * Strip out IP options.
1800 ip_stripoptions(struct mbuf *m)
1803 struct ip *ip = mtod(m, struct ip *);
1807 optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1808 opts = (caddr_t)(ip + 1);
1809 datalen = m->m_len - (sizeof(struct ip) + optlen);
1810 bcopy(opts + optlen, opts, datalen);
1812 if (m->m_flags & M_PKTHDR)
1813 m->m_pkthdr.len -= optlen;
1814 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1817 u_char inetctlerrmap[PRC_NCMDS] = {
1819 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1820 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1821 EMSGSIZE, EHOSTUNREACH, 0, 0,
1823 ENOPROTOOPT, ECONNREFUSED
1827 * Forward a packet. If some error occurs return the sender
1828 * an icmp packet. Note we can't always generate a meaningful
1829 * icmp message because icmp doesn't have a large enough repertoire
1830 * of codes and types.
1832 * If not forwarding, just drop the packet. This could be confusing
1833 * if ipforwarding was zero but some routing protocol was advancing
1834 * us as a gateway to somewhere. However, we must let the routing
1835 * protocol deal with that.
1837 * The using_srcrt parameter indicates whether the packet is being forwarded
1838 * via a source route.
1841 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop)
1843 struct ip *ip = mtod(m, struct ip *);
1845 struct route fwd_ro;
1846 int error, type = 0, code = 0, destmtu = 0;
1847 struct mbuf *mcopy, *mtemp = NULL;
1849 struct in_addr pkt_dst;
1853 * Cache the destination address of the packet; this may be
1854 * changed by use of 'ipfw fwd'.
1856 pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst;
1860 kprintf("forward: src %x dst %x ttl %x\n",
1861 ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl);
1864 if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) {
1865 ipstat.ips_cantforward++;
1869 if (!ipstealth && ip->ip_ttl <= IPTTLDEC) {
1870 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1874 bzero(&fwd_ro, sizeof(fwd_ro));
1875 ip_rtaddr(pkt_dst, &fwd_ro);
1876 if (fwd_ro.ro_rt == NULL) {
1877 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1882 if (curthread->td_type == TD_TYPE_NETISR) {
1884 * Save the IP header and at most 8 bytes of the payload,
1885 * in case we need to generate an ICMP message to the src.
1887 mtemp = ipforward_mtemp[mycpuid];
1888 KASSERT((mtemp->m_flags & M_EXT) == 0 &&
1889 mtemp->m_data == mtemp->m_pktdat &&
1890 m_tag_first(mtemp) == NULL,
1891 ("ip_forward invalid mtemp1"));
1893 if (!m_dup_pkthdr(mtemp, m, MB_DONTWAIT)) {
1895 * It's probably ok if the pkthdr dup fails (because
1896 * the deep copy of the tag chain failed), but for now
1897 * be conservative and just discard the copy since
1898 * code below may some day want the tags.
1902 mtemp->m_type = m->m_type;
1903 mtemp->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8,
1905 mtemp->m_pkthdr.len = mtemp->m_len;
1906 m_copydata(m, 0, mtemp->m_len, mtod(mtemp, caddr_t));
1911 ip->ip_ttl -= IPTTLDEC;
1914 * If forwarding packet using same interface that it came in on,
1915 * perhaps should send a redirect to sender to shortcut a hop.
1916 * Only send redirect if source is sending directly to us,
1917 * and if packet was not source routed (or has any options).
1918 * Also, don't send redirect if forwarding using a default route
1919 * or a route modified by a redirect.
1921 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1922 !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) &&
1923 satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY &&
1924 ipsendredirects && !using_srcrt && next_hop == NULL) {
1925 u_long src = ntohl(ip->ip_src.s_addr);
1926 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa;
1928 if (rt_ifa != NULL &&
1929 (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) {
1930 if (rt->rt_flags & RTF_GATEWAY)
1931 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1933 dest = pkt_dst.s_addr;
1935 * Router requirements says to only send
1938 type = ICMP_REDIRECT;
1939 code = ICMP_REDIRECT_HOST;
1942 kprintf("redirect (%d) to %x\n", code, dest);
1947 error = ip_output(m, NULL, &fwd_ro, IP_FORWARDING, NULL, NULL);
1949 ipstat.ips_forward++;
1952 ipflow_create(&fwd_ro, mtemp);
1955 ipstat.ips_redirectsent++;
1958 ipstat.ips_cantforward++;
1965 * Errors that do not require generating ICMP message
1970 * A router should not generate ICMP_SOURCEQUENCH as
1971 * required in RFC1812 Requirements for IP Version 4 Routers.
1972 * Source quench could be a big problem under DoS attacks,
1973 * or if the underlying interface is rate-limited.
1974 * Those who need source quench packets may re-enable them
1975 * via the net.inet.ip.sendsourcequench sysctl.
1977 if (!ip_sendsourcequench)
1981 case EACCES: /* ipfw denied packet */
1985 KASSERT((mtemp->m_flags & M_EXT) == 0 &&
1986 mtemp->m_data == mtemp->m_pktdat,
1987 ("ip_forward invalid mtemp2"));
1988 mcopy = m_copym(mtemp, 0, mtemp->m_len, MB_DONTWAIT);
1993 * Send ICMP message.
1996 case 0: /* forwarded, but need redirect */
1997 /* type, code set above */
2000 case ENETUNREACH: /* shouldn't happen, checked above */
2005 type = ICMP_UNREACH;
2006 code = ICMP_UNREACH_HOST;
2010 type = ICMP_UNREACH;
2011 code = ICMP_UNREACH_NEEDFRAG;
2014 * If the packet is routed over IPsec tunnel, tell the
2015 * originator the tunnel MTU.
2016 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2019 if (fwd_ro.ro_rt != NULL) {
2020 struct secpolicy *sp = NULL;
2025 sp = ipsec4_getpolicybyaddr(mcopy,
2031 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2033 /* count IPsec header size */
2034 ipsechdr = ipsec4_hdrsiz(mcopy,
2039 * find the correct route for outer IPv4
2040 * header, compute tunnel MTU.
2043 if (sp->req != NULL && sp->req->sav != NULL &&
2044 sp->req->sav->sah != NULL) {
2045 ro = &sp->req->sav->sah->sa_route;
2046 if (ro->ro_rt != NULL &&
2047 ro->ro_rt->rt_ifp != NULL) {
2049 ro->ro_rt->rt_ifp->if_mtu;
2050 destmtu -= ipsechdr;
2059 * If the packet is routed over IPsec tunnel, tell the
2060 * originator the tunnel MTU.
2061 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2064 if (fwd_ro.ro_rt != NULL) {
2065 struct secpolicy *sp = NULL;
2070 sp = ipsec_getpolicybyaddr(mcopy,
2076 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2078 /* count IPsec header size */
2079 ipsechdr = ipsec4_hdrsiz(mcopy,
2084 * find the correct route for outer IPv4
2085 * header, compute tunnel MTU.
2088 if (sp->req != NULL &&
2089 sp->req->sav != NULL &&
2090 sp->req->sav->sah != NULL) {
2091 ro = &sp->req->sav->sah->sa_route;
2092 if (ro->ro_rt != NULL &&
2093 ro->ro_rt->rt_ifp != NULL) {
2095 ro->ro_rt->rt_ifp->if_mtu;
2096 destmtu -= ipsechdr;
2103 #else /* !IPSEC && !FAST_IPSEC */
2104 if (fwd_ro.ro_rt != NULL)
2105 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2107 ipstat.ips_cantfrag++;
2111 type = ICMP_SOURCEQUENCH;
2115 case EACCES: /* ipfw denied packet */
2116 panic("ip_forward EACCES should not reach");
2118 icmp_error(mcopy, type, code, dest, destmtu);
2121 m_tag_delete_chain(mtemp);
2122 if (fwd_ro.ro_rt != NULL)
2123 RTFREE(fwd_ro.ro_rt);
2127 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
2130 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
2134 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
2135 SCM_TIMESTAMP, SOL_SOCKET);
2137 mp = &(*mp)->m_next;
2139 if (inp->inp_flags & INP_RECVDSTADDR) {
2140 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
2141 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2143 mp = &(*mp)->m_next;
2145 if (inp->inp_flags & INP_RECVTTL) {
2146 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
2147 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
2149 mp = &(*mp)->m_next;
2153 * Moving these out of udp_input() made them even more broken
2154 * than they already were.
2156 /* options were tossed already */
2157 if (inp->inp_flags & INP_RECVOPTS) {
2158 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
2159 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
2161 mp = &(*mp)->m_next;
2163 /* ip_srcroute doesn't do what we want here, need to fix */
2164 if (inp->inp_flags & INP_RECVRETOPTS) {
2165 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
2166 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
2168 mp = &(*mp)->m_next;
2171 if (inp->inp_flags & INP_RECVIF) {
2174 struct sockaddr_dl sdl;
2177 struct sockaddr_dl *sdp;
2178 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
2180 if (((ifp = m->m_pkthdr.rcvif)) &&
2181 ((ifp->if_index != 0) && (ifp->if_index <= if_index))) {
2182 sdp = IF_LLSOCKADDR(ifp);
2184 * Change our mind and don't try copy.
2186 if ((sdp->sdl_family != AF_LINK) ||
2187 (sdp->sdl_len > sizeof(sdlbuf))) {
2190 bcopy(sdp, sdl2, sdp->sdl_len);
2194 offsetof(struct sockaddr_dl, sdl_data[0]);
2195 sdl2->sdl_family = AF_LINK;
2196 sdl2->sdl_index = 0;
2197 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2199 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2200 IP_RECVIF, IPPROTO_IP);
2202 mp = &(*mp)->m_next;
2207 * XXX these routines are called from the upper part of the kernel.
2209 * They could also be moved to ip_mroute.c, since all the RSVP
2210 * handling is done there already.
2213 ip_rsvp_init(struct socket *so)
2215 if (so->so_type != SOCK_RAW ||
2216 so->so_proto->pr_protocol != IPPROTO_RSVP)
2219 if (ip_rsvpd != NULL)
2224 * This may seem silly, but we need to be sure we don't over-increment
2225 * the RSVP counter, in case something slips up.
2240 * This may seem silly, but we need to be sure we don't over-decrement
2241 * the RSVP counter, in case something slips up.
2251 rsvp_input(struct mbuf **mp, int *offp, int proto)
2253 struct mbuf *m = *mp;
2257 if (rsvp_input_p) { /* call the real one if loaded */
2259 rsvp_input_p(mp, offp, proto);
2260 return(IPPROTO_DONE);
2263 /* Can still get packets with rsvp_on = 0 if there is a local member
2264 * of the group to which the RSVP packet is addressed. But in this
2265 * case we want to throw the packet away.
2270 return(IPPROTO_DONE);
2273 if (ip_rsvpd != NULL) {
2275 rip_input(mp, offp, proto);
2276 return(IPPROTO_DONE);
2278 /* Drop the packet */
2280 return(IPPROTO_DONE);