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"
37 #include "opt_ipstealth.h"
38 #include "opt_ipsec.h"
39 #include "opt_route.h"
42 #include <sys/param.h>
43 #include <sys/systm.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 /* Skip initialization of globals for non-default instances. */
322 if (!IS_DEFAULT_VNET(curvnet))
325 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
327 panic("ip_init: PF_INET not found");
329 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
330 for (i = 0; i < IPPROTO_MAX; i++)
331 ip_protox[i] = pr - inetsw;
333 * Cycle through IP protocols and put them into the appropriate place
336 for (pr = inetdomain.dom_protosw;
337 pr < inetdomain.dom_protoswNPROTOSW; pr++)
338 if (pr->pr_domain->dom_family == PF_INET &&
339 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
340 /* Be careful to only index valid IP protocols. */
341 if (pr->pr_protocol < IPPROTO_MAX)
342 ip_protox[pr->pr_protocol] = pr - inetsw;
345 netisr_register(&ip_nh);
347 netisr_register(&ip_direct_nh);
357 if ((i = pfil_head_unregister(&V_inet_pfil_hook)) != 0)
358 printf("%s: WARNING: unable to unregister pfil hook, "
359 "error %d\n", __func__, i);
361 /* Cleanup in_ifaddr hash table; should be empty. */
362 hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
364 /* Destroy IP reassembly queue. */
371 * IP direct input routine.
373 * This is called when reinjecting completed fragments where
374 * all of the previous checking and book-keeping has been done.
377 ip_direct_input(struct mbuf *m)
382 ip = mtod(m, struct ip *);
383 hlen = ip->ip_hl << 2;
385 IPSTAT_INC(ips_delivered);
386 (*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
392 * Ip input routine. Checksum and byte swap header. If fragmented
393 * try to reassemble. Process options. Pass to next level.
396 ip_input(struct mbuf *m)
398 struct ip *ip = NULL;
399 struct in_ifaddr *ia = NULL;
402 int checkif, hlen = 0;
403 uint16_t sum, ip_len;
404 int dchg = 0; /* dest changed after fw */
405 struct in_addr odst; /* original dst address */
409 if (m->m_flags & M_FASTFWD_OURS) {
410 m->m_flags &= ~M_FASTFWD_OURS;
411 /* Set up some basics that will be used later. */
412 ip = mtod(m, struct ip *);
413 hlen = ip->ip_hl << 2;
414 ip_len = ntohs(ip->ip_len);
418 IPSTAT_INC(ips_total);
420 if (m->m_pkthdr.len < sizeof(struct ip))
423 if (m->m_len < sizeof (struct ip) &&
424 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
425 IPSTAT_INC(ips_toosmall);
428 ip = mtod(m, struct ip *);
430 if (ip->ip_v != IPVERSION) {
431 IPSTAT_INC(ips_badvers);
435 hlen = ip->ip_hl << 2;
436 if (hlen < sizeof(struct ip)) { /* minimum header length */
437 IPSTAT_INC(ips_badhlen);
440 if (hlen > m->m_len) {
441 if ((m = m_pullup(m, hlen)) == NULL) {
442 IPSTAT_INC(ips_badhlen);
445 ip = mtod(m, struct ip *);
448 IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL);
450 /* 127/8 must not appear on wire - RFC1122 */
451 ifp = m->m_pkthdr.rcvif;
452 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
453 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
454 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
455 IPSTAT_INC(ips_badaddr);
460 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
461 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
463 if (hlen == sizeof(struct ip)) {
464 sum = in_cksum_hdr(ip);
466 sum = in_cksum(m, hlen);
470 IPSTAT_INC(ips_badsum);
475 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
476 /* packet is dropped by traffic conditioner */
480 ip_len = ntohs(ip->ip_len);
482 IPSTAT_INC(ips_badlen);
487 * Check that the amount of data in the buffers
488 * is as at least much as the IP header would have us expect.
489 * Trim mbufs if longer than we expect.
490 * Drop packet if shorter than we expect.
492 if (m->m_pkthdr.len < ip_len) {
494 IPSTAT_INC(ips_tooshort);
497 if (m->m_pkthdr.len > ip_len) {
498 if (m->m_len == m->m_pkthdr.len) {
500 m->m_pkthdr.len = ip_len;
502 m_adj(m, ip_len - m->m_pkthdr.len);
505 /* Try to forward the packet, but if we fail continue */
507 /* For now we do not handle IPSEC in tryforward. */
508 if (!key_havesp(IPSEC_DIR_INBOUND) && !key_havesp(IPSEC_DIR_OUTBOUND) &&
509 (V_ipforwarding == 1))
510 if (ip_tryforward(m) == NULL)
513 * Bypass packet filtering for packets previously handled by IPsec.
515 if (ip_ipsec_filtertunnel(m))
518 if (V_ipforwarding == 1)
519 if (ip_tryforward(m) == NULL)
524 * Run through list of hooks for input packets.
526 * NB: Beware of the destination address changing (e.g.
527 * by NAT rewriting). When this happens, tell
528 * ip_forward to do the right thing.
531 /* Jump over all PFIL processing if hooks are not active. */
532 if (!PFIL_HOOKED(&V_inet_pfil_hook))
536 if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, NULL) != 0)
538 if (m == NULL) /* consumed by filter */
541 ip = mtod(m, struct ip *);
542 dchg = (odst.s_addr != ip->ip_dst.s_addr);
543 ifp = m->m_pkthdr.rcvif;
545 if (m->m_flags & M_FASTFWD_OURS) {
546 m->m_flags &= ~M_FASTFWD_OURS;
549 if (m->m_flags & M_IP_NEXTHOP) {
550 dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL);
553 * Directly ship the packet on. This allows
554 * forwarding packets originally destined to us
555 * to some other directly connected host.
564 * Process options and, if not destined for us,
565 * ship it on. ip_dooptions returns 1 when an
566 * error was detected (causing an icmp message
567 * to be sent and the original packet to be freed).
569 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
572 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
573 * matter if it is destined to another node, or whether it is
574 * a multicast one, RSVP wants it! and prevents it from being forwarded
575 * anywhere else. Also checks if the rsvp daemon is running before
576 * grabbing the packet.
578 if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
582 * Check our list of addresses, to see if the packet is for us.
583 * If we don't have any addresses, assume any unicast packet
584 * we receive might be for us (and let the upper layers deal
587 if (TAILQ_EMPTY(&V_in_ifaddrhead) &&
588 (m->m_flags & (M_MCAST|M_BCAST)) == 0)
592 * Enable a consistency check between the destination address
593 * and the arrival interface for a unicast packet (the RFC 1122
594 * strong ES model) if IP forwarding is disabled and the packet
595 * is not locally generated and the packet is not subject to
598 * XXX - Checking also should be disabled if the destination
599 * address is ipnat'ed to a different interface.
601 * XXX - Checking is incompatible with IP aliases added
602 * to the loopback interface instead of the interface where
603 * the packets are received.
605 * XXX - This is the case for carp vhost IPs as well so we
606 * insert a workaround. If the packet got here, we already
607 * checked with carp_iamatch() and carp_forus().
609 checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
610 ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
611 ifp->if_carp == NULL && (dchg == 0);
614 * Check for exact addresses in the hash bucket.
616 /* IN_IFADDR_RLOCK(); */
617 LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
619 * If the address matches, verify that the packet
620 * arrived via the correct interface if checking is
623 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
624 (!checkif || ia->ia_ifp == ifp)) {
625 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
626 counter_u64_add(ia->ia_ifa.ifa_ibytes,
628 /* IN_IFADDR_RUNLOCK(); */
632 /* IN_IFADDR_RUNLOCK(); */
635 * Check for broadcast addresses.
637 * Only accept broadcast packets that arrive via the matching
638 * interface. Reception of forwarded directed broadcasts would
639 * be handled via ip_forward() and ether_output() with the loopback
640 * into the stack for SIMPLEX interfaces handled by ether_output().
642 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
644 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
645 if (ifa->ifa_addr->sa_family != AF_INET)
648 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
650 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
651 counter_u64_add(ia->ia_ifa.ifa_ibytes,
653 IF_ADDR_RUNLOCK(ifp);
657 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
658 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
659 counter_u64_add(ia->ia_ifa.ifa_ibytes,
661 IF_ADDR_RUNLOCK(ifp);
666 IF_ADDR_RUNLOCK(ifp);
669 /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
670 if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
671 IPSTAT_INC(ips_cantforward);
675 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
678 * If we are acting as a multicast router, all
679 * incoming multicast packets are passed to the
680 * kernel-level multicast forwarding function.
681 * The packet is returned (relatively) intact; if
682 * ip_mforward() returns a non-zero value, the packet
683 * must be discarded, else it may be accepted below.
685 if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
686 IPSTAT_INC(ips_cantforward);
692 * The process-level routing daemon needs to receive
693 * all multicast IGMP packets, whether or not this
694 * host belongs to their destination groups.
696 if (ip->ip_p == IPPROTO_IGMP)
698 IPSTAT_INC(ips_forward);
701 * Assume the packet is for us, to avoid prematurely taking
702 * a lock on the in_multi hash. Protocols must perform
703 * their own filtering and update statistics accordingly.
707 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
709 if (ip->ip_dst.s_addr == INADDR_ANY)
713 * Not for us; forward if possible and desirable.
715 if (V_ipforwarding == 0) {
716 IPSTAT_INC(ips_cantforward);
726 * IPSTEALTH: Process non-routing options only
727 * if the packet is destined for us.
729 if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1))
731 #endif /* IPSTEALTH */
734 * Attempt reassembly; if it succeeds, proceed.
735 * ip_reass() will return a different mbuf.
737 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
738 /* XXXGL: shouldn't we save & set m_flags? */
742 ip = mtod(m, struct ip *);
743 /* Get the header length of the reassembled packet */
744 hlen = ip->ip_hl << 2;
749 * enforce IPsec policy checking if we are seeing last header.
750 * note that we do not visit this with protocols with pcb layer
751 * code - like udp/tcp/raw ip.
753 if (ip_ipsec_input(m, ip->ip_p) != 0)
758 * Switch out to protocol's input routine.
760 IPSTAT_INC(ips_delivered);
762 (*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
769 * IP timer processing;
770 * if a timer expires on a reassembly
776 VNET_ITERATOR_DECL(vnet_iter);
778 VNET_LIST_RLOCK_NOSLEEP();
779 VNET_FOREACH(vnet_iter) {
780 CURVNET_SET(vnet_iter);
784 VNET_LIST_RUNLOCK_NOSLEEP();
790 VNET_ITERATOR_DECL(vnet_iter);
792 VNET_LIST_RLOCK_NOSLEEP();
793 VNET_FOREACH(vnet_iter) {
794 CURVNET_SET(vnet_iter);
798 VNET_LIST_RUNLOCK_NOSLEEP();
802 * The protocol to be inserted into ip_protox[] must be already registered
803 * in inetsw[], either statically or through pf_proto_register().
806 ipproto_register(short ipproto)
811 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
812 return (EPROTONOSUPPORT);
815 * The protocol slot must not be occupied by another protocol
816 * already. An index pointing to IPPROTO_RAW is unused.
818 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
820 return (EPFNOSUPPORT);
821 if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */
824 /* Find the protocol position in inetsw[] and set the index. */
825 for (pr = inetdomain.dom_protosw;
826 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
827 if (pr->pr_domain->dom_family == PF_INET &&
828 pr->pr_protocol && pr->pr_protocol == ipproto) {
829 ip_protox[pr->pr_protocol] = pr - inetsw;
833 return (EPROTONOSUPPORT);
837 ipproto_unregister(short ipproto)
842 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
843 return (EPROTONOSUPPORT);
845 /* Check if the protocol was indeed registered. */
846 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
848 return (EPFNOSUPPORT);
849 if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */
852 /* Reset the protocol slot to IPPROTO_RAW. */
853 ip_protox[ipproto] = pr - inetsw;
858 * Given address of next destination (final or next hop), return (referenced)
859 * internet address info of interface to be used to get there.
862 ip_rtaddr(struct in_addr dst, u_int fibnum)
865 struct sockaddr_in *sin;
866 struct in_ifaddr *ia;
868 bzero(&sro, sizeof(sro));
869 sin = (struct sockaddr_in *)&sro.ro_dst;
870 sin->sin_family = AF_INET;
871 sin->sin_len = sizeof(*sin);
873 in_rtalloc_ign(&sro, 0, fibnum);
875 if (sro.ro_rt == NULL)
878 ia = ifatoia(sro.ro_rt->rt_ifa);
879 ifa_ref(&ia->ia_ifa);
884 u_char inetctlerrmap[PRC_NCMDS] = {
886 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
887 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
888 EMSGSIZE, EHOSTUNREACH, 0, 0,
889 0, 0, EHOSTUNREACH, 0,
890 ENOPROTOOPT, ECONNREFUSED
894 * Forward a packet. If some error occurs return the sender
895 * an icmp packet. Note we can't always generate a meaningful
896 * icmp message because icmp doesn't have a large enough repertoire
897 * of codes and types.
899 * If not forwarding, just drop the packet. This could be confusing
900 * if ipforwarding was zero but some routing protocol was advancing
901 * us as a gateway to somewhere. However, we must let the routing
902 * protocol deal with that.
904 * The srcrt parameter indicates whether the packet is being forwarded
905 * via a source route.
908 ip_forward(struct mbuf *m, int srcrt)
910 struct ip *ip = mtod(m, struct ip *);
911 struct in_ifaddr *ia;
913 struct sockaddr_in *sin;
916 int error, type = 0, code = 0, mtu = 0;
918 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
919 IPSTAT_INC(ips_cantforward);
924 if (ip_ipsec_fwd(m) != 0) {
925 IPSTAT_INC(ips_cantforward);
933 if (ip->ip_ttl <= IPTTLDEC) {
934 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
942 bzero(&ro, sizeof(ro));
943 sin = (struct sockaddr_in *)&ro.ro_dst;
944 sin->sin_family = AF_INET;
945 sin->sin_len = sizeof(*sin);
946 sin->sin_addr = ip->ip_dst;
948 rtalloc_mpath_fib(&ro,
949 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
952 in_rtalloc_ign(&ro, 0, M_GETFIB(m));
954 if (ro.ro_rt != NULL) {
955 ia = ifatoia(ro.ro_rt->rt_ifa);
956 ifa_ref(&ia->ia_ifa);
961 * 'ia' may be NULL if there is no route for this destination.
962 * In case of IPsec, Don't discard it just yet, but pass it to
963 * ip_output in case of outgoing IPsec policy.
965 if (!srcrt && ia == NULL) {
966 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
973 * Save the IP header and at most 8 bytes of the payload,
974 * in case we need to generate an ICMP message to the src.
976 * XXX this can be optimized a lot by saving the data in a local
977 * buffer on the stack (72 bytes at most), and only allocating the
978 * mbuf if really necessary. The vast majority of the packets
979 * are forwarded without having to send an ICMP back (either
980 * because unnecessary, or because rate limited), so we are
981 * really we are wasting a lot of work here.
983 * We don't use m_copy() because it might return a reference
984 * to a shared cluster. Both this function and ip_output()
985 * assume exclusive access to the IP header in `m', so any
986 * data in a cluster may change before we reach icmp_error().
988 mcopy = m_gethdr(M_NOWAIT, m->m_type);
989 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
991 * It's probably ok if the pkthdr dup fails (because
992 * the deep copy of the tag chain failed), but for now
993 * be conservative and just discard the copy since
994 * code below may some day want the tags.
1000 mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
1001 mcopy->m_pkthdr.len = mcopy->m_len;
1002 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1008 ip->ip_ttl -= IPTTLDEC;
1014 * If forwarding packet using same interface that it came in on,
1015 * perhaps should send a redirect to sender to shortcut a hop.
1016 * Only send redirect if source is sending directly to us,
1017 * and if packet was not source routed (or has any options).
1018 * Also, don't send redirect if forwarding using a default route
1019 * or a route modified by a redirect.
1022 if (!srcrt && V_ipsendredirects &&
1023 ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1028 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1029 satosin(rt_key(rt))->sin_addr.s_addr != 0) {
1030 #define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1031 u_long src = ntohl(ip->ip_src.s_addr);
1034 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1035 if (rt->rt_flags & RTF_GATEWAY)
1036 dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
1038 dest.s_addr = ip->ip_dst.s_addr;
1039 /* Router requirements says to only send host redirects */
1040 type = ICMP_REDIRECT;
1041 code = ICMP_REDIRECT_HOST;
1046 error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1048 if (error == EMSGSIZE && ro.ro_rt)
1049 mtu = ro.ro_rt->rt_mtu;
1053 IPSTAT_INC(ips_cantforward);
1055 IPSTAT_INC(ips_forward);
1057 IPSTAT_INC(ips_redirectsent);
1062 ifa_free(&ia->ia_ifa);
1066 if (mcopy == NULL) {
1068 ifa_free(&ia->ia_ifa);
1074 case 0: /* forwarded, but need redirect */
1075 /* type, code set above */
1083 type = ICMP_UNREACH;
1084 code = ICMP_UNREACH_HOST;
1088 type = ICMP_UNREACH;
1089 code = ICMP_UNREACH_NEEDFRAG;
1093 * If IPsec is configured for this path,
1094 * override any possibly mtu value set by ip_output.
1096 mtu = ip_ipsec_mtu(mcopy, mtu);
1099 * If the MTU was set before make sure we are below the
1101 * If the MTU wasn't set before use the interface mtu or
1102 * fall back to the next smaller mtu step compared to the
1103 * current packet size.
1107 mtu = min(mtu, ia->ia_ifp->if_mtu);
1110 mtu = ia->ia_ifp->if_mtu;
1112 mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
1114 IPSTAT_INC(ips_cantfrag);
1118 case EACCES: /* ipfw denied packet */
1121 ifa_free(&ia->ia_ifa);
1125 ifa_free(&ia->ia_ifa);
1126 icmp_error(mcopy, type, code, dest.s_addr, mtu);
1130 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1134 if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
1138 if (inp->inp_socket->so_options & SO_BINTIME) {
1139 *mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
1140 SCM_BINTIME, SOL_SOCKET);
1142 mp = &(*mp)->m_next;
1144 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1147 bintime2timeval(&bt, &tv);
1148 *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
1149 SCM_TIMESTAMP, SOL_SOCKET);
1151 mp = &(*mp)->m_next;
1154 if (inp->inp_flags & INP_RECVDSTADDR) {
1155 *mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
1156 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1158 mp = &(*mp)->m_next;
1160 if (inp->inp_flags & INP_RECVTTL) {
1161 *mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
1162 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1164 mp = &(*mp)->m_next;
1168 * Moving these out of udp_input() made them even more broken
1169 * than they already were.
1171 /* options were tossed already */
1172 if (inp->inp_flags & INP_RECVOPTS) {
1173 *mp = sbcreatecontrol((caddr_t)opts_deleted_above,
1174 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1176 mp = &(*mp)->m_next;
1178 /* ip_srcroute doesn't do what we want here, need to fix */
1179 if (inp->inp_flags & INP_RECVRETOPTS) {
1180 *mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
1181 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1183 mp = &(*mp)->m_next;
1186 if (inp->inp_flags & INP_RECVIF) {
1189 struct sockaddr_dl sdl;
1192 struct sockaddr_dl *sdp;
1193 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1195 if ((ifp = m->m_pkthdr.rcvif) &&
1196 ifp->if_index && ifp->if_index <= V_if_index) {
1197 sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1199 * Change our mind and don't try copy.
1201 if (sdp->sdl_family != AF_LINK ||
1202 sdp->sdl_len > sizeof(sdlbuf)) {
1205 bcopy(sdp, sdl2, sdp->sdl_len);
1209 offsetof(struct sockaddr_dl, sdl_data[0]);
1210 sdl2->sdl_family = AF_LINK;
1211 sdl2->sdl_index = 0;
1212 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1214 *mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
1215 IP_RECVIF, IPPROTO_IP);
1217 mp = &(*mp)->m_next;
1219 if (inp->inp_flags & INP_RECVTOS) {
1220 *mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
1221 sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
1223 mp = &(*mp)->m_next;
1226 if (inp->inp_flags2 & INP_RECVFLOWID) {
1227 uint32_t flowid, flow_type;
1229 flowid = m->m_pkthdr.flowid;
1230 flow_type = M_HASHTYPE_GET(m);
1233 * XXX should handle the failure of one or the
1234 * other - don't populate both?
1236 *mp = sbcreatecontrol((caddr_t) &flowid,
1237 sizeof(uint32_t), IP_FLOWID, IPPROTO_IP);
1239 mp = &(*mp)->m_next;
1240 *mp = sbcreatecontrol((caddr_t) &flow_type,
1241 sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP);
1243 mp = &(*mp)->m_next;
1247 if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
1248 uint32_t flowid, flow_type;
1249 uint32_t rss_bucketid;
1251 flowid = m->m_pkthdr.flowid;
1252 flow_type = M_HASHTYPE_GET(m);
1254 if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
1255 *mp = sbcreatecontrol((caddr_t) &rss_bucketid,
1256 sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP);
1258 mp = &(*mp)->m_next;
1265 * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1266 * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1267 * locking. This code remains in ip_input.c as ip_mroute.c is optionally
1270 static VNET_DEFINE(int, ip_rsvp_on);
1271 VNET_DEFINE(struct socket *, ip_rsvpd);
1273 #define V_ip_rsvp_on VNET(ip_rsvp_on)
1276 ip_rsvp_init(struct socket *so)
1279 if (so->so_type != SOCK_RAW ||
1280 so->so_proto->pr_protocol != IPPROTO_RSVP)
1283 if (V_ip_rsvpd != NULL)
1288 * This may seem silly, but we need to be sure we don't over-increment
1289 * the RSVP counter, in case something slips up.
1291 if (!V_ip_rsvp_on) {
1305 * This may seem silly, but we need to be sure we don't over-decrement
1306 * the RSVP counter, in case something slips up.
1316 rsvp_input(struct mbuf **mp, int *offp, int proto)
1323 if (rsvp_input_p) { /* call the real one if loaded */
1325 rsvp_input_p(mp, offp, proto);
1326 return (IPPROTO_DONE);
1329 /* Can still get packets with rsvp_on = 0 if there is a local member
1330 * of the group to which the RSVP packet is addressed. But in this
1331 * case we want to throw the packet away.
1336 return (IPPROTO_DONE);
1339 if (V_ip_rsvpd != NULL) {
1341 rip_input(mp, offp, proto);
1342 return (IPPROTO_DONE);
1344 /* Drop the packet */
1346 return (IPPROTO_DONE);