2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include "opt_bootp.h"
36 #include "opt_ipstealth.h"
37 #include "opt_ipsec.h"
38 #include "opt_route.h"
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/hhook.h>
45 #include <sys/malloc.h>
46 #include <sys/domain.h>
47 #include <sys/protosw.h>
48 #include <sys/socket.h>
50 #include <sys/kernel.h>
52 #include <sys/rmlock.h>
53 #include <sys/rwlock.h>
55 #include <sys/syslog.h>
56 #include <sys/sysctl.h>
60 #include <net/if_types.h>
61 #include <net/if_var.h>
62 #include <net/if_dl.h>
63 #include <net/route.h>
64 #include <net/netisr.h>
65 #include <net/rss_config.h>
68 #include <netinet/in.h>
69 #include <netinet/in_kdtrace.h>
70 #include <netinet/in_systm.h>
71 #include <netinet/in_var.h>
72 #include <netinet/ip.h>
73 #include <netinet/in_pcb.h>
74 #include <netinet/ip_var.h>
75 #include <netinet/ip_fw.h>
76 #include <netinet/ip_icmp.h>
77 #include <netinet/ip_options.h>
78 #include <machine/in_cksum.h>
79 #include <netinet/ip_carp.h>
81 #include <netinet/ip_ipsec.h>
82 #include <netipsec/ipsec.h>
83 #include <netipsec/key.h>
85 #include <netinet/in_rss.h>
87 #include <sys/socketvar.h>
89 #include <security/mac/mac_framework.h>
92 CTASSERT(sizeof(struct ip) == 20);
95 /* IP reassembly functions are defined in ip_reass.c. */
96 extern void ipreass_init(void);
97 extern void ipreass_drain(void);
98 extern void ipreass_slowtimo(void);
100 extern void ipreass_destroy(void);
103 struct rmlock in_ifaddr_lock;
104 RM_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
106 VNET_DEFINE(int, rsvp_on);
108 VNET_DEFINE(int, ipforwarding);
109 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_VNET | CTLFLAG_RW,
110 &VNET_NAME(ipforwarding), 0,
111 "Enable IP forwarding between interfaces");
113 static VNET_DEFINE(int, ipsendredirects) = 1; /* XXX */
114 #define V_ipsendredirects VNET(ipsendredirects)
115 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_VNET | CTLFLAG_RW,
116 &VNET_NAME(ipsendredirects), 0,
117 "Enable sending IP redirects");
120 * XXX - Setting ip_checkinterface mostly implements the receive side of
121 * the Strong ES model described in RFC 1122, but since the routing table
122 * and transmit implementation do not implement the Strong ES model,
123 * setting this to 1 results in an odd hybrid.
125 * XXX - ip_checkinterface currently must be disabled if you use ipnat
126 * to translate the destination address to another local interface.
128 * XXX - ip_checkinterface must be disabled if you add IP aliases
129 * to the loopback interface instead of the interface where the
130 * packets for those addresses are received.
132 static VNET_DEFINE(int, ip_checkinterface);
133 #define V_ip_checkinterface VNET(ip_checkinterface)
134 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_VNET | CTLFLAG_RW,
135 &VNET_NAME(ip_checkinterface), 0,
136 "Verify packet arrives on correct interface");
138 VNET_DEFINE(struct pfil_head, inet_pfil_hook); /* Packet filter hooks */
140 static struct netisr_handler ip_nh = {
142 .nh_handler = ip_input,
143 .nh_proto = NETISR_IP,
145 .nh_m2cpuid = rss_soft_m2cpuid_v4,
146 .nh_policy = NETISR_POLICY_CPU,
147 .nh_dispatch = NETISR_DISPATCH_HYBRID,
149 .nh_policy = NETISR_POLICY_FLOW,
155 * Directly dispatched frames are currently assumed
156 * to have a flowid already calculated.
158 * It should likely have something that assert it
159 * actually has valid flow details.
161 static struct netisr_handler ip_direct_nh = {
162 .nh_name = "ip_direct",
163 .nh_handler = ip_direct_input,
164 .nh_proto = NETISR_IP_DIRECT,
165 .nh_m2cpuid = rss_soft_m2cpuid_v4,
166 .nh_policy = NETISR_POLICY_CPU,
167 .nh_dispatch = NETISR_DISPATCH_HYBRID,
171 extern struct domain inetdomain;
172 extern struct protosw inetsw[];
173 u_char ip_protox[IPPROTO_MAX];
174 VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead); /* first inet address */
175 VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table */
176 VNET_DEFINE(u_long, in_ifaddrhmask); /* mask for hash table */
179 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
180 &ip_mtu, 0, "Default MTU");
184 VNET_DEFINE(int, ipstealth);
185 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_VNET | CTLFLAG_RW,
186 &VNET_NAME(ipstealth), 0,
187 "IP stealth mode, no TTL decrementation on forwarding");
191 * IP statistics are stored in the "array" of counter(9)s.
193 VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat);
194 VNET_PCPUSTAT_SYSINIT(ipstat);
195 SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat,
196 "IP statistics (struct ipstat, netinet/ip_var.h)");
199 VNET_PCPUSTAT_SYSUNINIT(ipstat);
203 * Kernel module interface for updating ipstat. The argument is an index
204 * into ipstat treated as an array.
207 kmod_ipstat_inc(int statnum)
210 counter_u64_add(VNET(ipstat)[statnum], 1);
214 kmod_ipstat_dec(int statnum)
217 counter_u64_add(VNET(ipstat)[statnum], -1);
221 sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
225 netisr_getqlimit(&ip_nh, &qlimit);
226 error = sysctl_handle_int(oidp, &qlimit, 0, req);
227 if (error || !req->newptr)
231 return (netisr_setqlimit(&ip_nh, qlimit));
233 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
234 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I",
235 "Maximum size of the IP input queue");
238 sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
240 u_int64_t qdrops_long;
243 netisr_getqdrops(&ip_nh, &qdrops_long);
244 qdrops = qdrops_long;
245 error = sysctl_handle_int(oidp, &qdrops, 0, req);
246 if (error || !req->newptr)
250 netisr_clearqdrops(&ip_nh);
254 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
255 CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I",
256 "Number of packets dropped from the IP input queue");
260 sysctl_netinet_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)
264 netisr_getqlimit(&ip_direct_nh, &qlimit);
265 error = sysctl_handle_int(oidp, &qlimit, 0, req);
266 if (error || !req->newptr)
270 return (netisr_setqlimit(&ip_direct_nh, qlimit));
272 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_direct_queue_maxlen,
273 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_direct_queue_maxlen, "I",
274 "Maximum size of the IP direct input queue");
277 sysctl_netinet_intr_direct_queue_drops(SYSCTL_HANDLER_ARGS)
279 u_int64_t qdrops_long;
282 netisr_getqdrops(&ip_direct_nh, &qdrops_long);
283 qdrops = qdrops_long;
284 error = sysctl_handle_int(oidp, &qdrops, 0, req);
285 if (error || !req->newptr)
289 netisr_clearqdrops(&ip_direct_nh);
293 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_direct_queue_drops,
294 CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_direct_queue_drops, "I",
295 "Number of packets dropped from the IP direct input queue");
299 * IP initialization: fill in IP protocol switch table.
300 * All protocols not implemented in kernel go to raw IP protocol handler.
308 TAILQ_INIT(&V_in_ifaddrhead);
309 V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
311 /* Initialize IP reassembly queue. */
314 /* Initialize packet filter hooks. */
315 V_inet_pfil_hook.ph_type = PFIL_TYPE_AF;
316 V_inet_pfil_hook.ph_af = AF_INET;
317 if ((i = pfil_head_register(&V_inet_pfil_hook)) != 0)
318 printf("%s: WARNING: unable to register pfil hook, "
319 "error %d\n", __func__, i);
321 if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET,
322 &V_ipsec_hhh_in[HHOOK_IPSEC_INET],
323 HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
324 printf("%s: WARNING: unable to register input helper hook\n",
326 if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET,
327 &V_ipsec_hhh_out[HHOOK_IPSEC_INET],
328 HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
329 printf("%s: WARNING: unable to register output helper hook\n",
332 /* Skip initialization of globals for non-default instances. */
334 if (!IS_DEFAULT_VNET(curvnet)) {
335 netisr_register_vnet(&ip_nh);
337 netisr_register_vnet(&ip_direct_nh);
343 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
345 panic("ip_init: PF_INET not found");
347 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
348 for (i = 0; i < IPPROTO_MAX; i++)
349 ip_protox[i] = pr - inetsw;
351 * Cycle through IP protocols and put them into the appropriate place
354 for (pr = inetdomain.dom_protosw;
355 pr < inetdomain.dom_protoswNPROTOSW; pr++)
356 if (pr->pr_domain->dom_family == PF_INET &&
357 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
358 /* Be careful to only index valid IP protocols. */
359 if (pr->pr_protocol < IPPROTO_MAX)
360 ip_protox[pr->pr_protocol] = pr - inetsw;
363 netisr_register(&ip_nh);
365 netisr_register(&ip_direct_nh);
371 ip_destroy(void *unused __unused)
377 netisr_unregister_vnet(&ip_direct_nh);
379 netisr_unregister_vnet(&ip_nh);
381 if ((error = pfil_head_unregister(&V_inet_pfil_hook)) != 0)
382 printf("%s: WARNING: unable to unregister pfil hook, "
383 "error %d\n", __func__, error);
385 error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET]);
387 printf("%s: WARNING: unable to deregister input helper hook "
388 "type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET: "
389 "error %d returned\n", __func__, error);
391 error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET]);
393 printf("%s: WARNING: unable to deregister output helper hook "
394 "type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET: "
395 "error %d returned\n", __func__, error);
398 /* Remove the IPv4 addresses from all interfaces. */
401 /* Make sure the IPv4 routes are gone as well. */
403 TAILQ_FOREACH(ifp, &V_ifnet, if_link)
404 rt_flushifroutes_af(ifp, AF_INET);
407 /* Destroy IP reassembly queue. */
410 /* Cleanup in_ifaddr hash table; should be empty. */
411 hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
414 VNET_SYSUNINIT(ip, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip_destroy, NULL);
419 * IP direct input routine.
421 * This is called when reinjecting completed fragments where
422 * all of the previous checking and book-keeping has been done.
425 ip_direct_input(struct mbuf *m)
430 ip = mtod(m, struct ip *);
431 hlen = ip->ip_hl << 2;
433 IPSTAT_INC(ips_delivered);
434 (*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
440 * Ip input routine. Checksum and byte swap header. If fragmented
441 * try to reassemble. Process options. Pass to next level.
444 ip_input(struct mbuf *m)
446 struct ip *ip = NULL;
447 struct in_ifaddr *ia = NULL;
450 int checkif, hlen = 0;
451 uint16_t sum, ip_len;
452 int dchg = 0; /* dest changed after fw */
453 struct in_addr odst; /* original dst address */
457 if (m->m_flags & M_FASTFWD_OURS) {
458 m->m_flags &= ~M_FASTFWD_OURS;
459 /* Set up some basics that will be used later. */
460 ip = mtod(m, struct ip *);
461 hlen = ip->ip_hl << 2;
462 ip_len = ntohs(ip->ip_len);
466 IPSTAT_INC(ips_total);
468 if (m->m_pkthdr.len < sizeof(struct ip))
471 if (m->m_len < sizeof (struct ip) &&
472 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
473 IPSTAT_INC(ips_toosmall);
476 ip = mtod(m, struct ip *);
478 if (ip->ip_v != IPVERSION) {
479 IPSTAT_INC(ips_badvers);
483 hlen = ip->ip_hl << 2;
484 if (hlen < sizeof(struct ip)) { /* minimum header length */
485 IPSTAT_INC(ips_badhlen);
488 if (hlen > m->m_len) {
489 if ((m = m_pullup(m, hlen)) == NULL) {
490 IPSTAT_INC(ips_badhlen);
493 ip = mtod(m, struct ip *);
496 IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL);
498 /* 127/8 must not appear on wire - RFC1122 */
499 ifp = m->m_pkthdr.rcvif;
500 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
501 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
502 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
503 IPSTAT_INC(ips_badaddr);
508 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
509 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
511 if (hlen == sizeof(struct ip)) {
512 sum = in_cksum_hdr(ip);
514 sum = in_cksum(m, hlen);
518 IPSTAT_INC(ips_badsum);
523 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
524 /* packet is dropped by traffic conditioner */
528 ip_len = ntohs(ip->ip_len);
530 IPSTAT_INC(ips_badlen);
535 * Check that the amount of data in the buffers
536 * is as at least much as the IP header would have us expect.
537 * Trim mbufs if longer than we expect.
538 * Drop packet if shorter than we expect.
540 if (m->m_pkthdr.len < ip_len) {
542 IPSTAT_INC(ips_tooshort);
545 if (m->m_pkthdr.len > ip_len) {
546 if (m->m_len == m->m_pkthdr.len) {
548 m->m_pkthdr.len = ip_len;
550 m_adj(m, ip_len - m->m_pkthdr.len);
553 /* Try to forward the packet, but if we fail continue */
555 /* For now we do not handle IPSEC in tryforward. */
556 if (!key_havesp(IPSEC_DIR_INBOUND) && !key_havesp(IPSEC_DIR_OUTBOUND) &&
557 (V_ipforwarding == 1))
558 if (ip_tryforward(m) == NULL)
561 * Bypass packet filtering for packets previously handled by IPsec.
563 if (ip_ipsec_filtertunnel(m))
566 if (V_ipforwarding == 1)
567 if (ip_tryforward(m) == NULL)
572 * Run through list of hooks for input packets.
574 * NB: Beware of the destination address changing (e.g.
575 * by NAT rewriting). When this happens, tell
576 * ip_forward to do the right thing.
579 /* Jump over all PFIL processing if hooks are not active. */
580 if (!PFIL_HOOKED(&V_inet_pfil_hook))
584 if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, NULL) != 0)
586 if (m == NULL) /* consumed by filter */
589 ip = mtod(m, struct ip *);
590 dchg = (odst.s_addr != ip->ip_dst.s_addr);
591 ifp = m->m_pkthdr.rcvif;
593 if (m->m_flags & M_FASTFWD_OURS) {
594 m->m_flags &= ~M_FASTFWD_OURS;
597 if (m->m_flags & M_IP_NEXTHOP) {
598 if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
600 * Directly ship the packet on. This allows
601 * forwarding packets originally destined to us
602 * to some other directly connected host.
611 * Process options and, if not destined for us,
612 * ship it on. ip_dooptions returns 1 when an
613 * error was detected (causing an icmp message
614 * to be sent and the original packet to be freed).
616 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
619 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
620 * matter if it is destined to another node, or whether it is
621 * a multicast one, RSVP wants it! and prevents it from being forwarded
622 * anywhere else. Also checks if the rsvp daemon is running before
623 * grabbing the packet.
625 if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
629 * Check our list of addresses, to see if the packet is for us.
630 * If we don't have any addresses, assume any unicast packet
631 * we receive might be for us (and let the upper layers deal
634 if (TAILQ_EMPTY(&V_in_ifaddrhead) &&
635 (m->m_flags & (M_MCAST|M_BCAST)) == 0)
639 * Enable a consistency check between the destination address
640 * and the arrival interface for a unicast packet (the RFC 1122
641 * strong ES model) if IP forwarding is disabled and the packet
642 * is not locally generated and the packet is not subject to
645 * XXX - Checking also should be disabled if the destination
646 * address is ipnat'ed to a different interface.
648 * XXX - Checking is incompatible with IP aliases added
649 * to the loopback interface instead of the interface where
650 * the packets are received.
652 * XXX - This is the case for carp vhost IPs as well so we
653 * insert a workaround. If the packet got here, we already
654 * checked with carp_iamatch() and carp_forus().
656 checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
657 ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
658 ifp->if_carp == NULL && (dchg == 0);
661 * Check for exact addresses in the hash bucket.
663 /* IN_IFADDR_RLOCK(); */
664 LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
666 * If the address matches, verify that the packet
667 * arrived via the correct interface if checking is
670 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
671 (!checkif || ia->ia_ifp == ifp)) {
672 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
673 counter_u64_add(ia->ia_ifa.ifa_ibytes,
675 /* IN_IFADDR_RUNLOCK(); */
679 /* IN_IFADDR_RUNLOCK(); */
682 * Check for broadcast addresses.
684 * Only accept broadcast packets that arrive via the matching
685 * interface. Reception of forwarded directed broadcasts would
686 * be handled via ip_forward() and ether_output() with the loopback
687 * into the stack for SIMPLEX interfaces handled by ether_output().
689 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
691 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
692 if (ifa->ifa_addr->sa_family != AF_INET)
695 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
697 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
698 counter_u64_add(ia->ia_ifa.ifa_ibytes,
700 IF_ADDR_RUNLOCK(ifp);
704 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
705 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
706 counter_u64_add(ia->ia_ifa.ifa_ibytes,
708 IF_ADDR_RUNLOCK(ifp);
713 IF_ADDR_RUNLOCK(ifp);
716 /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
717 if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
718 IPSTAT_INC(ips_cantforward);
722 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
725 * If we are acting as a multicast router, all
726 * incoming multicast packets are passed to the
727 * kernel-level multicast forwarding function.
728 * The packet is returned (relatively) intact; if
729 * ip_mforward() returns a non-zero value, the packet
730 * must be discarded, else it may be accepted below.
732 if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
733 IPSTAT_INC(ips_cantforward);
739 * The process-level routing daemon needs to receive
740 * all multicast IGMP packets, whether or not this
741 * host belongs to their destination groups.
743 if (ip->ip_p == IPPROTO_IGMP)
745 IPSTAT_INC(ips_forward);
748 * Assume the packet is for us, to avoid prematurely taking
749 * a lock on the in_multi hash. Protocols must perform
750 * their own filtering and update statistics accordingly.
754 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
756 if (ip->ip_dst.s_addr == INADDR_ANY)
760 * Not for us; forward if possible and desirable.
762 if (V_ipforwarding == 0) {
763 IPSTAT_INC(ips_cantforward);
773 * IPSTEALTH: Process non-routing options only
774 * if the packet is destined for us.
776 if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1))
778 #endif /* IPSTEALTH */
781 * Attempt reassembly; if it succeeds, proceed.
782 * ip_reass() will return a different mbuf.
784 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
785 /* XXXGL: shouldn't we save & set m_flags? */
789 ip = mtod(m, struct ip *);
790 /* Get the header length of the reassembled packet */
791 hlen = ip->ip_hl << 2;
796 * enforce IPsec policy checking if we are seeing last header.
797 * note that we do not visit this with protocols with pcb layer
798 * code - like udp/tcp/raw ip.
800 if (ip_ipsec_input(m, ip->ip_p) != 0)
805 * Switch out to protocol's input routine.
807 IPSTAT_INC(ips_delivered);
809 (*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
816 * IP timer processing;
817 * if a timer expires on a reassembly
823 VNET_ITERATOR_DECL(vnet_iter);
825 VNET_LIST_RLOCK_NOSLEEP();
826 VNET_FOREACH(vnet_iter) {
827 CURVNET_SET(vnet_iter);
831 VNET_LIST_RUNLOCK_NOSLEEP();
837 VNET_ITERATOR_DECL(vnet_iter);
839 VNET_LIST_RLOCK_NOSLEEP();
840 VNET_FOREACH(vnet_iter) {
841 CURVNET_SET(vnet_iter);
845 VNET_LIST_RUNLOCK_NOSLEEP();
849 * The protocol to be inserted into ip_protox[] must be already registered
850 * in inetsw[], either statically or through pf_proto_register().
853 ipproto_register(short ipproto)
858 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
859 return (EPROTONOSUPPORT);
862 * The protocol slot must not be occupied by another protocol
863 * already. An index pointing to IPPROTO_RAW is unused.
865 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
867 return (EPFNOSUPPORT);
868 if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */
871 /* Find the protocol position in inetsw[] and set the index. */
872 for (pr = inetdomain.dom_protosw;
873 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
874 if (pr->pr_domain->dom_family == PF_INET &&
875 pr->pr_protocol && pr->pr_protocol == ipproto) {
876 ip_protox[pr->pr_protocol] = pr - inetsw;
880 return (EPROTONOSUPPORT);
884 ipproto_unregister(short ipproto)
889 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
890 return (EPROTONOSUPPORT);
892 /* Check if the protocol was indeed registered. */
893 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
895 return (EPFNOSUPPORT);
896 if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */
899 /* Reset the protocol slot to IPPROTO_RAW. */
900 ip_protox[ipproto] = pr - inetsw;
904 u_char inetctlerrmap[PRC_NCMDS] = {
906 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
907 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
908 EMSGSIZE, EHOSTUNREACH, 0, 0,
909 0, 0, EHOSTUNREACH, 0,
910 ENOPROTOOPT, ECONNREFUSED
914 * Forward a packet. If some error occurs return the sender
915 * an icmp packet. Note we can't always generate a meaningful
916 * icmp message because icmp doesn't have a large enough repertoire
917 * of codes and types.
919 * If not forwarding, just drop the packet. This could be confusing
920 * if ipforwarding was zero but some routing protocol was advancing
921 * us as a gateway to somewhere. However, we must let the routing
922 * protocol deal with that.
924 * The srcrt parameter indicates whether the packet is being forwarded
925 * via a source route.
928 ip_forward(struct mbuf *m, int srcrt)
930 struct ip *ip = mtod(m, struct ip *);
931 struct in_ifaddr *ia;
933 struct sockaddr_in *sin;
936 int error, type = 0, code = 0, mtu = 0;
938 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
939 IPSTAT_INC(ips_cantforward);
944 if (ip_ipsec_fwd(m) != 0) {
945 IPSTAT_INC(ips_cantforward);
953 if (ip->ip_ttl <= IPTTLDEC) {
954 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
962 bzero(&ro, sizeof(ro));
963 sin = (struct sockaddr_in *)&ro.ro_dst;
964 sin->sin_family = AF_INET;
965 sin->sin_len = sizeof(*sin);
966 sin->sin_addr = ip->ip_dst;
968 rtalloc_mpath_fib(&ro,
969 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
972 in_rtalloc_ign(&ro, 0, M_GETFIB(m));
974 if (ro.ro_rt != NULL) {
975 ia = ifatoia(ro.ro_rt->rt_ifa);
976 ifa_ref(&ia->ia_ifa);
981 * 'ia' may be NULL if there is no route for this destination.
982 * In case of IPsec, Don't discard it just yet, but pass it to
983 * ip_output in case of outgoing IPsec policy.
985 if (!srcrt && ia == NULL) {
986 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
993 * Save the IP header and at most 8 bytes of the payload,
994 * in case we need to generate an ICMP message to the src.
996 * XXX this can be optimized a lot by saving the data in a local
997 * buffer on the stack (72 bytes at most), and only allocating the
998 * mbuf if really necessary. The vast majority of the packets
999 * are forwarded without having to send an ICMP back (either
1000 * because unnecessary, or because rate limited), so we are
1001 * really we are wasting a lot of work here.
1003 * We don't use m_copym() because it might return a reference
1004 * to a shared cluster. Both this function and ip_output()
1005 * assume exclusive access to the IP header in `m', so any
1006 * data in a cluster may change before we reach icmp_error().
1008 mcopy = m_gethdr(M_NOWAIT, m->m_type);
1009 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
1011 * It's probably ok if the pkthdr dup fails (because
1012 * the deep copy of the tag chain failed), but for now
1013 * be conservative and just discard the copy since
1014 * code below may some day want the tags.
1019 if (mcopy != NULL) {
1020 mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
1021 mcopy->m_pkthdr.len = mcopy->m_len;
1022 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1028 ip->ip_ttl -= IPTTLDEC;
1034 * If forwarding packet using same interface that it came in on,
1035 * perhaps should send a redirect to sender to shortcut a hop.
1036 * Only send redirect if source is sending directly to us,
1037 * and if packet was not source routed (or has any options).
1038 * Also, don't send redirect if forwarding using a default route
1039 * or a route modified by a redirect.
1042 if (!srcrt && V_ipsendredirects &&
1043 ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1048 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1049 satosin(rt_key(rt))->sin_addr.s_addr != 0) {
1050 #define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1051 u_long src = ntohl(ip->ip_src.s_addr);
1054 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1055 if (rt->rt_flags & RTF_GATEWAY)
1056 dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
1058 dest.s_addr = ip->ip_dst.s_addr;
1059 /* Router requirements says to only send host redirects */
1060 type = ICMP_REDIRECT;
1061 code = ICMP_REDIRECT_HOST;
1066 error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1068 if (error == EMSGSIZE && ro.ro_rt)
1069 mtu = ro.ro_rt->rt_mtu;
1073 IPSTAT_INC(ips_cantforward);
1075 IPSTAT_INC(ips_forward);
1077 IPSTAT_INC(ips_redirectsent);
1082 ifa_free(&ia->ia_ifa);
1086 if (mcopy == NULL) {
1088 ifa_free(&ia->ia_ifa);
1094 case 0: /* forwarded, but need redirect */
1095 /* type, code set above */
1103 type = ICMP_UNREACH;
1104 code = ICMP_UNREACH_HOST;
1108 type = ICMP_UNREACH;
1109 code = ICMP_UNREACH_NEEDFRAG;
1113 * If IPsec is configured for this path,
1114 * override any possibly mtu value set by ip_output.
1116 mtu = ip_ipsec_mtu(mcopy, mtu);
1119 * If the MTU was set before make sure we are below the
1121 * If the MTU wasn't set before use the interface mtu or
1122 * fall back to the next smaller mtu step compared to the
1123 * current packet size.
1127 mtu = min(mtu, ia->ia_ifp->if_mtu);
1130 mtu = ia->ia_ifp->if_mtu;
1132 mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
1134 IPSTAT_INC(ips_cantfrag);
1138 case EACCES: /* ipfw denied packet */
1141 ifa_free(&ia->ia_ifa);
1145 ifa_free(&ia->ia_ifa);
1146 icmp_error(mcopy, type, code, dest.s_addr, mtu);
1150 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1154 if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
1158 if (inp->inp_socket->so_options & SO_BINTIME) {
1159 *mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
1160 SCM_BINTIME, SOL_SOCKET);
1162 mp = &(*mp)->m_next;
1164 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1167 bintime2timeval(&bt, &tv);
1168 *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
1169 SCM_TIMESTAMP, SOL_SOCKET);
1171 mp = &(*mp)->m_next;
1174 if (inp->inp_flags & INP_RECVDSTADDR) {
1175 *mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
1176 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1178 mp = &(*mp)->m_next;
1180 if (inp->inp_flags & INP_RECVTTL) {
1181 *mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
1182 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1184 mp = &(*mp)->m_next;
1188 * Moving these out of udp_input() made them even more broken
1189 * than they already were.
1191 /* options were tossed already */
1192 if (inp->inp_flags & INP_RECVOPTS) {
1193 *mp = sbcreatecontrol((caddr_t)opts_deleted_above,
1194 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1196 mp = &(*mp)->m_next;
1198 /* ip_srcroute doesn't do what we want here, need to fix */
1199 if (inp->inp_flags & INP_RECVRETOPTS) {
1200 *mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
1201 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1203 mp = &(*mp)->m_next;
1206 if (inp->inp_flags & INP_RECVIF) {
1209 struct sockaddr_dl sdl;
1212 struct sockaddr_dl *sdp;
1213 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1215 if ((ifp = m->m_pkthdr.rcvif) &&
1216 ifp->if_index && ifp->if_index <= V_if_index) {
1217 sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1219 * Change our mind and don't try copy.
1221 if (sdp->sdl_family != AF_LINK ||
1222 sdp->sdl_len > sizeof(sdlbuf)) {
1225 bcopy(sdp, sdl2, sdp->sdl_len);
1229 offsetof(struct sockaddr_dl, sdl_data[0]);
1230 sdl2->sdl_family = AF_LINK;
1231 sdl2->sdl_index = 0;
1232 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1234 *mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
1235 IP_RECVIF, IPPROTO_IP);
1237 mp = &(*mp)->m_next;
1239 if (inp->inp_flags & INP_RECVTOS) {
1240 *mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
1241 sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
1243 mp = &(*mp)->m_next;
1246 if (inp->inp_flags2 & INP_RECVFLOWID) {
1247 uint32_t flowid, flow_type;
1249 flowid = m->m_pkthdr.flowid;
1250 flow_type = M_HASHTYPE_GET(m);
1253 * XXX should handle the failure of one or the
1254 * other - don't populate both?
1256 *mp = sbcreatecontrol((caddr_t) &flowid,
1257 sizeof(uint32_t), IP_FLOWID, IPPROTO_IP);
1259 mp = &(*mp)->m_next;
1260 *mp = sbcreatecontrol((caddr_t) &flow_type,
1261 sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP);
1263 mp = &(*mp)->m_next;
1267 if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
1268 uint32_t flowid, flow_type;
1269 uint32_t rss_bucketid;
1271 flowid = m->m_pkthdr.flowid;
1272 flow_type = M_HASHTYPE_GET(m);
1274 if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
1275 *mp = sbcreatecontrol((caddr_t) &rss_bucketid,
1276 sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP);
1278 mp = &(*mp)->m_next;
1285 * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1286 * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1287 * locking. This code remains in ip_input.c as ip_mroute.c is optionally
1290 static VNET_DEFINE(int, ip_rsvp_on);
1291 VNET_DEFINE(struct socket *, ip_rsvpd);
1293 #define V_ip_rsvp_on VNET(ip_rsvp_on)
1296 ip_rsvp_init(struct socket *so)
1299 if (so->so_type != SOCK_RAW ||
1300 so->so_proto->pr_protocol != IPPROTO_RSVP)
1303 if (V_ip_rsvpd != NULL)
1308 * This may seem silly, but we need to be sure we don't over-increment
1309 * the RSVP counter, in case something slips up.
1311 if (!V_ip_rsvp_on) {
1325 * This may seem silly, but we need to be sure we don't over-decrement
1326 * the RSVP counter, in case something slips up.
1336 rsvp_input(struct mbuf **mp, int *offp, int proto)
1343 if (rsvp_input_p) { /* call the real one if loaded */
1345 rsvp_input_p(mp, offp, proto);
1346 return (IPPROTO_DONE);
1349 /* Can still get packets with rsvp_on = 0 if there is a local member
1350 * of the group to which the RSVP packet is addressed. But in this
1351 * case we want to throw the packet away.
1356 return (IPPROTO_DONE);
1359 if (V_ip_rsvpd != NULL) {
1361 rip_input(mp, offp, proto);
1362 return (IPPROTO_DONE);
1364 /* Drop the packet */
1366 return (IPPROTO_DONE);