1 /* $NetBSD: ip_input.c,v 1.404 2024/07/05 04:31:54 rin Exp $ */
2
3 /*
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 /*
33 * Copyright (c) 1998 The NetBSD Foundation, Inc.
34 * All rights reserved.
35 *
36 * This code is derived from software contributed to The NetBSD Foundation
37 * by Public Access Networks Corporation ("Panix"). It was developed under
38 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 * notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 * notice, this list of conditions and the following disclaimer in the
47 * documentation and/or other materials provided with the distribution.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
50 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
52 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
59 * POSSIBILITY OF SUCH DAMAGE.
60 */
61
62 /*
63 * Copyright (c) 1982, 1986, 1988, 1993
64 * The Regents of the University of California. All rights reserved.
65 *
66 * Redistribution and use in source and binary forms, with or without
67 * modification, are permitted provided that the following conditions
68 * are met:
69 * 1. Redistributions of source code must retain the above copyright
70 * notice, this list of conditions and the following disclaimer.
71 * 2. Redistributions in binary form must reproduce the above copyright
72 * notice, this list of conditions and the following disclaimer in the
73 * documentation and/or other materials provided with the distribution.
74 * 3. Neither the name of the University nor the names of its contributors
75 * may be used to endorse or promote products derived from this software
76 * without specific prior written permission.
77 *
78 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
79 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
80 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
81 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
82 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
83 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
84 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
85 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
86 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
87 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
88 * SUCH DAMAGE.
89 *
90 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
91 */
92
93 #include <sys/cdefs.h>
94 __KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.404 2024/07/05 04:31:54 rin Exp $");
95
96 #ifdef _KERNEL_OPT
97 #include "opt_inet.h"
98 #include "opt_gateway.h"
99 #include "opt_ipsec.h"
100 #include "opt_mrouting.h"
101 #include "opt_mbuftrace.h"
102 #include "opt_inet_csum.h"
103 #include "opt_net_mpsafe.h"
104 #endif
105
106 #include "arp.h"
107
108 #include <sys/param.h>
109 #include <sys/systm.h>
110 #include <sys/cpu.h>
111 #include <sys/mbuf.h>
112 #include <sys/domain.h>
113 #include <sys/protosw.h>
114 #include <sys/socket.h>
115 #include <sys/socketvar.h>
116 #include <sys/errno.h>
117 #include <sys/time.h>
118 #include <sys/kernel.h>
119 #include <sys/pool.h>
120 #include <sys/sysctl.h>
121 #include <sys/kauth.h>
122
123 #include <net/if.h>
124 #include <net/if_dl.h>
125 #include <net/route.h>
126 #include <net/pktqueue.h>
127 #include <net/pfil.h>
128
129 #include <netinet/in.h>
130 #include <netinet/in_systm.h>
131 #include <netinet/ip.h>
132 #include <netinet/in_pcb.h>
133 #include <netinet/in_proto.h>
134 #include <netinet/in_var.h>
135 #include <netinet/ip_var.h>
136 #include <netinet/ip_private.h>
137 #include <netinet/ip_icmp.h>
138 /* just for gif_ttl */
139 #include <netinet/in_gif.h>
140 #include "gif.h"
141 #include <net/if_gre.h>
142 #include "gre.h"
143
144 #ifdef MROUTING
145 #include <netinet/ip_mroute.h>
146 #endif
147 #include <netinet/portalgo.h>
148
149 #ifdef IPSEC
150 #include <netipsec/ipsec.h>
151 #endif
152
153 #ifndef IPFORWARDING
154 #ifdef GATEWAY
155 #define IPFORWARDING 1 /* forward IP packets not for us */
156 #else
157 #define IPFORWARDING 0 /* don't forward IP packets not for us */
158 #endif
159 #endif
160
161 #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
162
163 int ipforwarding = IPFORWARDING;
164 int ipsendredirects = 1;
165 int ip_defttl = IPDEFTTL;
166 int ip_forwsrcrt = 0;
167 int ip_directedbcast = 0;
168 int ip_allowsrcrt = 0;
169 int ip_mtudisc = 1;
170 int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
171 int ip_do_randomid = 1;
172
173 /*
174 * XXX - Setting ip_checkinterface mostly implements the receive side of
175 * the Strong ES model described in RFC 1122, but since the routing table
176 * and transmit implementation do not implement the Strong ES model,
177 * setting this to 1 results in an odd hybrid.
178 *
179 * XXX - ip_checkinterface currently must be disabled if you use NAT
180 * to translate the destination address to another local interface.
181 *
182 * XXX - ip_checkinterface must be disabled if you add IP aliases
183 * to the loopback interface instead of the interface where the
184 * packets for those addresses are received.
185 */
186 static int ip_checkinterface __read_mostly = 0;
187
188 struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
189
190 pktqueue_t * ip_pktq __read_mostly;
191 pfil_head_t * inet_pfil_hook __read_mostly;
192 percpu_t * ipstat_percpu __read_mostly;
193
194 static percpu_t *ipforward_rt_percpu __cacheline_aligned;
195
196 uint16_t ip_id;
197
198 #ifdef INET_CSUM_COUNTERS
199 #include <sys/device.h>
200
201 struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
202 NULL, "inet", "hwcsum bad");
203 struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
204 NULL, "inet", "hwcsum ok");
205 struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
206 NULL, "inet", "swcsum");
207
208 #define INET_CSUM_COUNTER_INCR(ev) (ev)->ev_count++
209
210 EVCNT_ATTACH_STATIC(ip_hwcsum_bad);
211 EVCNT_ATTACH_STATIC(ip_hwcsum_ok);
212 EVCNT_ATTACH_STATIC(ip_swcsum);
213
214 #else
215
216 #define INET_CSUM_COUNTER_INCR(ev) /* nothing */
217
218 #endif /* INET_CSUM_COUNTERS */
219
220 /*
221 * Used to save the IP options in case a protocol wants to respond
222 * to an incoming packet over the same route if the packet got here
223 * using IP source routing. This allows connection establishment and
224 * maintenance when the remote end is on a network that is not known
225 * to us.
226 */
227 struct ip_srcrt {
228 int isr_nhops; /* number of hops */
229 struct in_addr isr_dst; /* final destination */
230 char isr_nop; /* one NOP to align */
231 char isr_hdr[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN & OFFSET */
232 struct in_addr isr_routes[MAX_IPOPTLEN/sizeof(struct in_addr)];
233 };
234
235 static int ip_drainwanted;
236
237 static void save_rte(struct mbuf *, u_char *, struct in_addr);
238
239 #ifdef MBUFTRACE
240 struct mowner ip_rx_mowner = MOWNER_INIT("internet", "rx");
241 struct mowner ip_tx_mowner = MOWNER_INIT("internet", "tx");
242 #endif
243
244 static void ipintr(void *);
245 static void ip_input(struct mbuf *, struct ifnet *);
246 static void ip_forward(struct mbuf *, int, struct ifnet *);
247 static bool ip_dooptions(struct mbuf *);
248 static struct in_ifaddr *ip_rtaddr(struct in_addr, struct psref *);
249 static void sysctl_net_inet_ip_setup(struct sysctllog **);
250
251 static struct in_ifaddr *ip_match_our_address(struct ifnet *, struct ip *,
252 int *);
253 static struct in_ifaddr *ip_match_our_address_broadcast(struct ifnet *,
254 struct ip *);
255
256 #ifdef NET_MPSAFE
257 #define SOFTNET_LOCK() mutex_enter(softnet_lock)
258 #define SOFTNET_UNLOCK() mutex_exit(softnet_lock)
259 #else
260 #define SOFTNET_LOCK() KASSERT(mutex_owned(softnet_lock))
261 #define SOFTNET_UNLOCK() KASSERT(mutex_owned(softnet_lock))
262 #endif
263
264 /*
265 * IP initialization: fill in IP protocol switch table.
266 * All protocols not implemented in kernel go to raw IP protocol handler.
267 */
268 void
ip_init(void)269 ip_init(void)
270 {
271 const struct protosw *pr;
272
273 ip_pktq = pktq_create(IFQ_MAXLEN, ipintr, NULL);
274 KASSERT(ip_pktq != NULL);
275
276 in_init();
277 sysctl_net_inet_ip_setup(NULL);
278
279 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
280 KASSERT(pr != NULL);
281
282 for (u_int i = 0; i < IPPROTO_MAX; i++) {
283 ip_protox[i] = pr - inetsw;
284 }
285 for (pr = inetdomain.dom_protosw;
286 pr < inetdomain.dom_protoswNPROTOSW; pr++)
287 if (pr->pr_domain->dom_family == PF_INET &&
288 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
289 ip_protox[pr->pr_protocol] = pr - inetsw;
290
291 ip_reass_init();
292
293 ip_id = time_uptime & 0xfffff;
294
295 #ifdef GATEWAY
296 ipflow_init();
297 #endif
298
299 /* Register our Packet Filter hook. */
300 inet_pfil_hook = pfil_head_create(PFIL_TYPE_AF, (void *)AF_INET);
301 KASSERT(inet_pfil_hook != NULL);
302
303 #ifdef MBUFTRACE
304 MOWNER_ATTACH(&ip_tx_mowner);
305 MOWNER_ATTACH(&ip_rx_mowner);
306 #endif
307
308 ipstat_percpu = percpu_alloc(sizeof(uint64_t) * IP_NSTATS);
309 ipforward_rt_percpu = rtcache_percpu_alloc();
310 ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
311 }
312
313 static struct in_ifaddr *
ip_match_our_address(struct ifnet * ifp,struct ip * ip,int * downmatch)314 ip_match_our_address(struct ifnet *ifp, struct ip *ip, int *downmatch)
315 {
316 struct in_ifaddr *ia = NULL;
317 int checkif;
318
319 /*
320 * Enable a consistency check between the destination address
321 * and the arrival interface for a unicast packet (the RFC 1122
322 * strong ES model) if IP forwarding is disabled and the packet
323 * is not locally generated.
324 *
325 * XXX - We need to add a per ifaddr flag for this so that
326 * we get finer grain control.
327 */
328 checkif = ip_checkinterface && (ipforwarding == 0) &&
329 (ifp->if_flags & IFF_LOOPBACK) == 0;
330
331 IN_ADDRHASH_READER_FOREACH(ia, ip->ip_dst.s_addr) {
332 if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
333 if (ia->ia4_flags & IN_IFF_NOTREADY)
334 continue;
335 if (checkif && ia->ia_ifp != ifp)
336 continue;
337 if ((ia->ia_ifp->if_flags & IFF_UP) == 0) {
338 (*downmatch)++;
339 continue;
340 }
341 if (ia->ia4_flags & IN_IFF_DETACHED &&
342 (ifp->if_flags & IFF_LOOPBACK) == 0)
343 continue;
344 break;
345 }
346 }
347
348 return ia;
349 }
350
351 static struct in_ifaddr *
ip_match_our_address_broadcast(struct ifnet * ifp,struct ip * ip)352 ip_match_our_address_broadcast(struct ifnet *ifp, struct ip *ip)
353 {
354 struct in_ifaddr *ia = NULL;
355 struct ifaddr *ifa;
356
357 IFADDR_READER_FOREACH(ifa, ifp) {
358 if (ifa->ifa_addr->sa_family != AF_INET)
359 continue;
360 ia = ifatoia(ifa);
361 if (ia->ia4_flags & IN_IFF_NOTREADY)
362 continue;
363 if (ia->ia4_flags & IN_IFF_DETACHED &&
364 (ifp->if_flags & IFF_LOOPBACK) == 0)
365 continue;
366 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
367 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
368 /*
369 * Look for all-0's host part (old broadcast addr),
370 * either for subnet or net.
371 */
372 ip->ip_dst.s_addr == ia->ia_subnet ||
373 ip->ip_dst.s_addr == ia->ia_net)
374 goto matched;
375 /*
376 * An interface with IP address zero accepts
377 * all packets that arrive on that interface.
378 */
379 if (in_nullhost(ia->ia_addr.sin_addr))
380 goto matched;
381 }
382 ia = NULL;
383
384 matched:
385 return ia;
386 }
387
388 /*
389 * IP software interrupt routine.
390 */
391 static void
ipintr(void * arg __unused)392 ipintr(void *arg __unused)
393 {
394 struct mbuf *m;
395
396 KASSERT(cpu_softintr_p());
397
398 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE();
399 while ((m = pktq_dequeue(ip_pktq)) != NULL) {
400 struct ifnet *ifp;
401 struct psref psref;
402
403 ifp = m_get_rcvif_psref(m, &psref);
404 if (__predict_false(ifp == NULL)) {
405 IP_STATINC(IP_STAT_IFDROP);
406 m_freem(m);
407 continue;
408 }
409
410 ip_input(m, ifp);
411
412 m_put_rcvif_psref(ifp, &psref);
413 }
414 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
415 }
416
417 /*
418 * IP input routine. Checksum and byte swap header. If fragmented
419 * try to reassemble. Process options. Pass to next level.
420 */
421 static void
ip_input(struct mbuf * m,struct ifnet * ifp)422 ip_input(struct mbuf *m, struct ifnet *ifp)
423 {
424 struct ip *ip = NULL;
425 struct in_ifaddr *ia = NULL;
426 int hlen = 0, len;
427 int downmatch;
428 int srcrt = 0;
429 int s;
430
431 KASSERTMSG(cpu_softintr_p(), "ip_input: not in the software "
432 "interrupt handler; synchronization assumptions violated");
433
434 MCLAIM(m, &ip_rx_mowner);
435 KASSERT((m->m_flags & M_PKTHDR) != 0);
436
437 /*
438 * If no IP addresses have been set yet but the interfaces
439 * are receiving, can't do anything with incoming packets yet.
440 * Note: we pre-check without locks held.
441 */
442 if (IN_ADDRLIST_READER_EMPTY()) {
443 IP_STATINC(IP_STAT_IFDROP);
444 goto out;
445 }
446
447 IP_STATINC(IP_STAT_TOTAL);
448
449 /*
450 * If the IP header is not aligned, slurp it up into a new
451 * mbuf with space for link headers, in the event we forward
452 * it. Otherwise, if it is aligned, make sure the entire
453 * base IP header is in the first mbuf of the chain.
454 */
455 if (M_GET_ALIGNED_HDR(&m, struct ip, true) != 0) {
456 /* XXXJRT new stat, please */
457 IP_STATINC(IP_STAT_TOOSMALL);
458 goto out;
459 }
460 ip = mtod(m, struct ip *);
461 if (ip->ip_v != IPVERSION) {
462 IP_STATINC(IP_STAT_BADVERS);
463 goto out;
464 }
465 hlen = ip->ip_hl << 2;
466 if (hlen < sizeof(struct ip)) { /* minimum header length */
467 IP_STATINC(IP_STAT_BADHLEN);
468 goto out;
469 }
470 if (hlen > m->m_len) {
471 if ((m = m_pullup(m, hlen)) == NULL) {
472 IP_STATINC(IP_STAT_BADHLEN);
473 goto out;
474 }
475 ip = mtod(m, struct ip *);
476 }
477
478 /*
479 * RFC1122: packets with a multicast source address are
480 * not allowed.
481 */
482 if (IN_MULTICAST(ip->ip_src.s_addr)) {
483 IP_STATINC(IP_STAT_BADADDR);
484 goto out;
485 }
486
487 /* 127/8 must not appear on wire - RFC1122 */
488 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
489 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
490 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
491 IP_STATINC(IP_STAT_BADADDR);
492 goto out;
493 }
494 }
495
496 switch (m->m_pkthdr.csum_flags &
497 ((ifp->if_csum_flags_rx & M_CSUM_IPv4) | M_CSUM_IPv4_BAD)) {
498 case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
499 INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
500 IP_STATINC(IP_STAT_BADSUM);
501 goto out;
502
503 case M_CSUM_IPv4:
504 /* Checksum was okay. */
505 INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
506 break;
507
508 default:
509 /*
510 * Must compute it ourselves. Maybe skip checksum on
511 * loopback interfaces.
512 */
513 if (__predict_true(!(ifp->if_flags & IFF_LOOPBACK) ||
514 ip_do_loopback_cksum)) {
515 INET_CSUM_COUNTER_INCR(&ip_swcsum);
516 if (in_cksum(m, hlen) != 0) {
517 IP_STATINC(IP_STAT_BADSUM);
518 goto out;
519 }
520 }
521 break;
522 }
523
524 /* Retrieve the packet length. */
525 len = ntohs(ip->ip_len);
526
527 /*
528 * Check for additional length bogosity
529 */
530 if (len < hlen) {
531 IP_STATINC(IP_STAT_BADLEN);
532 goto out;
533 }
534
535 /*
536 * Check that the amount of data in the buffers is at least as much
537 * as the IP header would have us expect. Trim mbufs if longer than
538 * we expect. Drop packet if shorter than we expect.
539 */
540 if (m->m_pkthdr.len < len) {
541 IP_STATINC(IP_STAT_TOOSHORT);
542 goto out;
543 }
544 if (m->m_pkthdr.len > len) {
545 if (m->m_len == m->m_pkthdr.len) {
546 m->m_len = len;
547 m->m_pkthdr.len = len;
548 } else
549 m_adj(m, len - m->m_pkthdr.len);
550 }
551
552 /*
553 * Assume that we can create a fast-forward IP flow entry
554 * based on this packet.
555 */
556 m->m_flags |= M_CANFASTFWD;
557
558 /*
559 * Run through list of hooks for input packets. If there are any
560 * filters which require that additional packets in the flow are
561 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
562 * Note that filters must _never_ set this flag, as another filter
563 * in the list may have previously cleared it.
564 *
565 * Don't call hooks if the packet has already been processed by
566 * IPsec (encapsulated, tunnel mode).
567 */
568 #if defined(IPSEC)
569 if (!ipsec_used || !ipsec_skip_pfil(m))
570 #else
571 if (1)
572 #endif
573 {
574 struct in_addr odst = ip->ip_dst;
575 bool freed;
576
577 freed = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_IN) != 0;
578 if (freed || m == NULL) {
579 m = NULL;
580 IP_STATINC(IP_STAT_PFILDROP_IN);
581 goto out;
582 }
583 if (__predict_false(m->m_len < sizeof(struct ip))) {
584 if ((m = m_pullup(m, sizeof(struct ip))) == NULL) {
585 IP_STATINC(IP_STAT_TOOSMALL);
586 goto out;
587 }
588 }
589 ip = mtod(m, struct ip *);
590 hlen = ip->ip_hl << 2;
591 if (hlen < sizeof(struct ip)) { /* minimum header length */
592 IP_STATINC(IP_STAT_BADHLEN);
593 goto out;
594 }
595 if (hlen > m->m_len) {
596 if ((m = m_pullup(m, hlen)) == NULL) {
597 IP_STATINC(IP_STAT_BADHLEN);
598 goto out;
599 }
600 ip = mtod(m, struct ip *);
601 }
602
603 /*
604 * XXX The setting of "srcrt" here is to prevent ip_forward()
605 * from generating ICMP redirects for packets that have
606 * been redirected by a hook back out on to the same LAN that
607 * they came from and is not an indication that the packet
608 * is being influenced by source routing options. This
609 * allows things like
610 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp"
611 * where tlp0 is both on the 1.1.1.0/24 network and is the
612 * default route for hosts on 1.1.1.0/24. Of course this
613 * also requires a "map tlp0 ..." to complete the story.
614 * One might argue whether or not this kind of network config.
615 * should be supported in this manner...
616 */
617 srcrt = (odst.s_addr != ip->ip_dst.s_addr);
618 }
619
620 #ifdef ALTQ
621 /* XXX Temporary until ALTQ is changed to use a pfil hook */
622 if (altq_input) {
623 SOFTNET_LOCK();
624 if ((*altq_input)(m, AF_INET) == 0) {
625 /* Packet dropped by traffic conditioner. */
626 SOFTNET_UNLOCK();
627 m = NULL;
628 goto out;
629 }
630 SOFTNET_UNLOCK();
631 }
632 #endif
633
634 /*
635 * Process options and, if not destined for us,
636 * ship it on. ip_dooptions returns 1 when an
637 * error was detected (causing an icmp message
638 * to be sent and the original packet to be freed).
639 */
640 if (hlen > sizeof(struct ip) && ip_dooptions(m)) {
641 m = NULL;
642 goto out;
643 }
644
645 /*
646 * Check our list of addresses, to see if the packet is for us.
647 *
648 * Traditional 4.4BSD did not consult IFF_UP at all.
649 * The behavior here is to treat addresses on !IFF_UP interface
650 * or IN_IFF_NOTREADY addresses as not mine.
651 */
652 downmatch = 0;
653 s = pserialize_read_enter();
654 ia = ip_match_our_address(ifp, ip, &downmatch);
655 if (ia != NULL) {
656 pserialize_read_exit(s);
657 goto ours;
658 }
659
660 if (ifp->if_flags & IFF_BROADCAST) {
661 ia = ip_match_our_address_broadcast(ifp, ip);
662 if (ia != NULL) {
663 pserialize_read_exit(s);
664 goto ours;
665 }
666 }
667 pserialize_read_exit(s);
668
669 if (IN_MULTICAST(ip->ip_dst.s_addr)) {
670 #ifdef MROUTING
671 extern struct socket *ip_mrouter;
672
673 if (ip_mrouter) {
674 /*
675 * If we are acting as a multicast router, all
676 * incoming multicast packets are passed to the
677 * kernel-level multicast forwarding function.
678 * The packet is returned (relatively) intact; if
679 * ip_mforward() returns a non-zero value, the packet
680 * must be discarded, else it may be accepted below.
681 *
682 * (The IP ident field is put in the same byte order
683 * as expected when ip_mforward() is called from
684 * ip_output().)
685 */
686 SOFTNET_LOCK();
687 if (ip_mforward(m, ifp) != 0) {
688 SOFTNET_UNLOCK();
689 IP_STATINC(IP_STAT_CANTFORWARD);
690 goto out;
691 }
692 SOFTNET_UNLOCK();
693
694 /*
695 * The process-level routing demon needs to receive
696 * all multicast IGMP packets, whether or not this
697 * host belongs to their destination groups.
698 */
699 if (ip->ip_p == IPPROTO_IGMP) {
700 goto ours;
701 }
702 IP_STATINC(IP_STAT_CANTFORWARD);
703 }
704 #endif
705 /*
706 * See if we belong to the destination multicast group on the
707 * arrival interface.
708 */
709 if (!in_multi_group(ip->ip_dst, ifp, 0)) {
710 IP_STATINC(IP_STAT_CANTFORWARD);
711 goto out;
712 }
713 goto ours;
714 }
715 if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
716 in_nullhost(ip->ip_dst))
717 goto ours;
718
719 /*
720 * Not for us; forward if possible and desirable.
721 */
722 if (ipforwarding == 0) {
723 IP_STATINC(IP_STAT_CANTFORWARD);
724 m_freem(m);
725 } else {
726 /*
727 * If ip_dst matched any of my address on !IFF_UP interface,
728 * and there's no IFF_UP interface that matches ip_dst,
729 * send icmp unreach. Forwarding it will result in in-kernel
730 * forwarding loop till TTL goes to 0.
731 */
732 if (downmatch) {
733 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
734 IP_STATINC(IP_STAT_CANTFORWARD);
735 return;
736 }
737 #ifdef IPSEC
738 /* Check the security policy (SP) for the packet */
739 if (ipsec_used) {
740 if (ipsec_ip_input_checkpolicy(m, true) != 0) {
741 IP_STATINC(IP_STAT_IPSECDROP_IN);
742 goto out;
743 }
744 }
745 #endif
746 ip_forward(m, srcrt, ifp);
747 }
748 return;
749
750 ours:
751 /*
752 * If offset or IP_MF are set, must reassemble.
753 */
754 if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
755 /*
756 * Pass to IP reassembly mechanism.
757 */
758 if (ip_reass_packet(&m) != 0) {
759 /* Failed; invalid fragment(s) or packet. */
760 goto out;
761 }
762 if (m == NULL) {
763 /* More fragments should come; silently return. */
764 goto out;
765 }
766 /*
767 * Reassembly is done, we have the final packet.
768 * Update cached data in local variable(s).
769 */
770 ip = mtod(m, struct ip *);
771 hlen = ip->ip_hl << 2;
772 }
773
774 M_VERIFY_PACKET(m);
775
776 #ifdef IPSEC
777 /*
778 * Enforce IPsec policy checking if we are seeing last header.
779 * Note that we do not visit this with protocols with PCB layer
780 * code - like UDP/TCP/raw IP.
781 */
782 if (ipsec_used &&
783 (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
784 if (ipsec_ip_input_checkpolicy(m, false) != 0) {
785 IP_STATINC(IP_STAT_IPSECDROP_IN);
786 goto out;
787 }
788 }
789 #endif
790
791 /*
792 * Switch out to protocol's input routine.
793 */
794 #if IFA_STATS
795 if (ia) {
796 struct in_ifaddr *_ia;
797 /*
798 * Keep a reference from ip_match_our_address with psref
799 * is expensive, so explore ia here again.
800 */
801 s = pserialize_read_enter();
802 _ia = in_get_ia(ip->ip_dst);
803 _ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
804 pserialize_read_exit(s);
805 }
806 #endif
807 IP_STATINC(IP_STAT_DELIVERED);
808
809 const int off = hlen, nh = ip->ip_p;
810
811 (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
812 return;
813
814 out:
815 m_freem(m);
816 }
817
818 /*
819 * IP timer processing.
820 */
821 void
ip_slowtimo(void)822 ip_slowtimo(void)
823 {
824
825 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE();
826
827 ip_reass_slowtimo();
828
829 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
830 }
831
832 /*
833 * IP drain processing.
834 */
835 void
ip_drain(void)836 ip_drain(void)
837 {
838
839 KERNEL_LOCK(1, NULL);
840 ip_reass_drain();
841 KERNEL_UNLOCK_ONE(NULL);
842 }
843
844 /*
845 * ip_dooptions: perform option processing on a datagram, possibly discarding
846 * it if bad options are encountered, or forwarding it if source-routed.
847 *
848 * => Returns true if packet has been forwarded/freed.
849 * => Returns false if the packet should be processed further.
850 */
851 static bool
ip_dooptions(struct mbuf * m)852 ip_dooptions(struct mbuf *m)
853 {
854 struct ip *ip = mtod(m, struct ip *);
855 u_char *cp, *cp0;
856 struct ip_timestamp *ipt;
857 struct in_ifaddr *ia;
858 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
859 int srr_present, rr_present, ts_present;
860 struct in_addr dst;
861 n_time ntime;
862 struct ifaddr *ifa = NULL;
863 int s;
864
865 srr_present = 0;
866 rr_present = 0;
867 ts_present = 0;
868
869 dst = ip->ip_dst;
870 cp = (u_char *)(ip + 1);
871 cnt = (ip->ip_hl << 2) - sizeof(struct ip);
872 for (; cnt > 0; cnt -= optlen, cp += optlen) {
873 opt = cp[IPOPT_OPTVAL];
874 if (opt == IPOPT_EOL)
875 break;
876 if (opt == IPOPT_NOP)
877 optlen = 1;
878 else {
879 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
880 code = &cp[IPOPT_OLEN] - (u_char *)ip;
881 goto bad;
882 }
883 optlen = cp[IPOPT_OLEN];
884 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
885 code = &cp[IPOPT_OLEN] - (u_char *)ip;
886 goto bad;
887 }
888 }
889 switch (opt) {
890
891 default:
892 break;
893
894 /*
895 * Source routing with record.
896 * Find interface with current destination address.
897 * If none on this machine then drop if strictly routed,
898 * or do nothing if loosely routed.
899 * Record interface address and bring up next address
900 * component. If strictly routed make sure next
901 * address is on directly accessible net.
902 */
903 case IPOPT_LSRR:
904 case IPOPT_SSRR: {
905 struct psref psref;
906 struct sockaddr_in ipaddr = {
907 .sin_len = sizeof(ipaddr),
908 .sin_family = AF_INET,
909 };
910
911 if (ip_allowsrcrt == 0) {
912 type = ICMP_UNREACH;
913 code = ICMP_UNREACH_NET_PROHIB;
914 goto bad;
915 }
916 if (srr_present++) {
917 code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
918 goto bad;
919 }
920 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
921 code = &cp[IPOPT_OLEN] - (u_char *)ip;
922 goto bad;
923 }
924 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
925 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
926 goto bad;
927 }
928 ipaddr.sin_addr = ip->ip_dst;
929
930 s = pserialize_read_enter();
931 ifa = ifa_ifwithaddr(sintosa(&ipaddr));
932 if (ifa == NULL) {
933 pserialize_read_exit(s);
934 if (opt == IPOPT_SSRR) {
935 type = ICMP_UNREACH;
936 code = ICMP_UNREACH_SRCFAIL;
937 goto bad;
938 }
939 /*
940 * Loose routing, and not at next destination
941 * yet; nothing to do except forward.
942 */
943 break;
944 }
945 pserialize_read_exit(s);
946
947 off--; /* 0 origin */
948 if ((off + sizeof(struct in_addr)) > optlen) {
949 /*
950 * End of source route. Should be for us.
951 */
952 save_rte(m, cp, ip->ip_src);
953 break;
954 }
955 /*
956 * locate outgoing interface
957 */
958 memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off),
959 sizeof(ipaddr.sin_addr));
960 if (opt == IPOPT_SSRR) {
961 ifa = ifa_ifwithladdr_psref(sintosa(&ipaddr),
962 &psref);
963 if (ifa != NULL)
964 ia = ifatoia(ifa);
965 else
966 ia = NULL;
967 } else {
968 ia = ip_rtaddr(ipaddr.sin_addr, &psref);
969 }
970 if (ia == NULL) {
971 type = ICMP_UNREACH;
972 code = ICMP_UNREACH_SRCFAIL;
973 goto bad;
974 }
975 ip->ip_dst = ipaddr.sin_addr;
976 memcpy(cp + off, &ia->ia_addr.sin_addr,
977 sizeof(struct in_addr));
978 ia4_release(ia, &psref);
979 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
980 /*
981 * Let ip_intr's mcast routing check handle mcast pkts
982 */
983 forward = !IN_MULTICAST(ip->ip_dst.s_addr);
984 break;
985 }
986
987 case IPOPT_RR: {
988 struct psref psref;
989 struct sockaddr_in ipaddr = {
990 .sin_len = sizeof(ipaddr),
991 .sin_family = AF_INET,
992 };
993
994 if (rr_present++) {
995 code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
996 goto bad;
997 }
998 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
999 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1000 goto bad;
1001 }
1002 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1003 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1004 goto bad;
1005 }
1006 /*
1007 * If no space remains, ignore.
1008 */
1009 off--; /* 0 origin */
1010 if ((off + sizeof(struct in_addr)) > optlen)
1011 break;
1012 memcpy((void *)&ipaddr.sin_addr, (void *)&ip->ip_dst,
1013 sizeof(ipaddr.sin_addr));
1014 /*
1015 * locate outgoing interface; if we're the destination,
1016 * use the incoming interface (should be same).
1017 */
1018 ifa = ifa_ifwithaddr_psref(sintosa(&ipaddr), &psref);
1019 if (ifa == NULL) {
1020 ia = ip_rtaddr(ipaddr.sin_addr, &psref);
1021 if (ia == NULL) {
1022 type = ICMP_UNREACH;
1023 code = ICMP_UNREACH_HOST;
1024 goto bad;
1025 }
1026 } else {
1027 ia = ifatoia(ifa);
1028 }
1029 memcpy(cp + off, &ia->ia_addr.sin_addr,
1030 sizeof(struct in_addr));
1031 ia4_release(ia, &psref);
1032 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1033 break;
1034 }
1035
1036 case IPOPT_TS:
1037 code = cp - (u_char *)ip;
1038 ipt = (struct ip_timestamp *)cp;
1039 if (ts_present++) {
1040 code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
1041 goto bad;
1042 }
1043 if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1044 code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1045 goto bad;
1046 }
1047 if (ipt->ipt_ptr < 5) {
1048 code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1049 goto bad;
1050 }
1051 if (ipt->ipt_ptr > ipt->ipt_len - sizeof(int32_t)) {
1052 if (++ipt->ipt_oflw == 0) {
1053 code = (u_char *)&ipt->ipt_ptr -
1054 (u_char *)ip;
1055 goto bad;
1056 }
1057 break;
1058 }
1059 cp0 = (cp + ipt->ipt_ptr - 1);
1060 switch (ipt->ipt_flg) {
1061
1062 case IPOPT_TS_TSONLY:
1063 break;
1064
1065 case IPOPT_TS_TSANDADDR: {
1066 struct ifnet *rcvif;
1067 int _s, _ss;
1068 struct sockaddr_in ipaddr = {
1069 .sin_len = sizeof(ipaddr),
1070 .sin_family = AF_INET,
1071 };
1072
1073 if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1074 sizeof(struct in_addr) > ipt->ipt_len) {
1075 code = (u_char *)&ipt->ipt_ptr -
1076 (u_char *)ip;
1077 goto bad;
1078 }
1079 ipaddr.sin_addr = dst;
1080 _ss = pserialize_read_enter();
1081 rcvif = m_get_rcvif(m, &_s);
1082 if (__predict_true(rcvif != NULL)) {
1083 ifa = ifaof_ifpforaddr(sintosa(&ipaddr),
1084 rcvif);
1085 }
1086 m_put_rcvif(rcvif, &_s);
1087 if (ifa == NULL) {
1088 pserialize_read_exit(_ss);
1089 break;
1090 }
1091 ia = ifatoia(ifa);
1092 memcpy(cp0, &ia->ia_addr.sin_addr,
1093 sizeof(struct in_addr));
1094 pserialize_read_exit(_ss);
1095 ipt->ipt_ptr += sizeof(struct in_addr);
1096 break;
1097 }
1098
1099 case IPOPT_TS_PRESPEC: {
1100 struct sockaddr_in ipaddr = {
1101 .sin_len = sizeof(ipaddr),
1102 .sin_family = AF_INET,
1103 };
1104
1105 if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1106 sizeof(struct in_addr) > ipt->ipt_len) {
1107 code = (u_char *)&ipt->ipt_ptr -
1108 (u_char *)ip;
1109 goto bad;
1110 }
1111 memcpy(&ipaddr.sin_addr, cp0,
1112 sizeof(struct in_addr));
1113 s = pserialize_read_enter();
1114 ifa = ifa_ifwithaddr(sintosa(&ipaddr));
1115 if (ifa == NULL) {
1116 pserialize_read_exit(s);
1117 continue;
1118 }
1119 pserialize_read_exit(s);
1120 ipt->ipt_ptr += sizeof(struct in_addr);
1121 break;
1122 }
1123
1124 default:
1125 /* XXX can't take &ipt->ipt_flg */
1126 code = (u_char *)&ipt->ipt_ptr -
1127 (u_char *)ip + 1;
1128 goto bad;
1129 }
1130 ntime = iptime();
1131 cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1132 memmove((char *)cp + ipt->ipt_ptr - 1, cp0,
1133 sizeof(n_time));
1134 ipt->ipt_ptr += sizeof(n_time);
1135 }
1136 }
1137 if (forward) {
1138 struct ifnet *rcvif;
1139 struct psref _psref;
1140
1141 if (ip_forwsrcrt == 0) {
1142 type = ICMP_UNREACH;
1143 code = ICMP_UNREACH_SRCFAIL;
1144 goto bad;
1145 }
1146
1147 rcvif = m_get_rcvif_psref(m, &_psref);
1148 if (__predict_false(rcvif == NULL)) {
1149 type = ICMP_UNREACH;
1150 code = ICMP_UNREACH_HOST;
1151 goto bad;
1152 }
1153 ip_forward(m, 1, rcvif);
1154 m_put_rcvif_psref(rcvif, &_psref);
1155 return true;
1156 }
1157 return false;
1158 bad:
1159 icmp_error(m, type, code, 0, 0);
1160 IP_STATINC(IP_STAT_BADOPTIONS);
1161 return true;
1162 }
1163
1164 /*
1165 * ip_rtaddr: given address of next destination (final or next hop),
1166 * return internet address info of interface to be used to get there.
1167 */
1168 static struct in_ifaddr *
ip_rtaddr(struct in_addr dst,struct psref * psref)1169 ip_rtaddr(struct in_addr dst, struct psref *psref)
1170 {
1171 struct rtentry *rt;
1172 union {
1173 struct sockaddr dst;
1174 struct sockaddr_in dst4;
1175 } u;
1176 struct route *ro;
1177
1178 sockaddr_in_init(&u.dst4, &dst, 0);
1179
1180 ro = rtcache_percpu_getref(ipforward_rt_percpu);
1181 rt = rtcache_lookup(ro, &u.dst);
1182 if (rt == NULL) {
1183 rtcache_percpu_putref(ipforward_rt_percpu);
1184 return NULL;
1185 }
1186
1187 ia4_acquire(ifatoia(rt->rt_ifa), psref);
1188 rtcache_unref(rt, ro);
1189 rtcache_percpu_putref(ipforward_rt_percpu);
1190
1191 return ifatoia(rt->rt_ifa);
1192 }
1193
1194 /*
1195 * save_rte: save incoming source route for use in replies, to be picked
1196 * up later by ip_srcroute if the receiver is interested.
1197 */
1198 static void
save_rte(struct mbuf * m,u_char * option,struct in_addr dst)1199 save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1200 {
1201 struct ip_srcrt *isr;
1202 struct m_tag *mtag;
1203 unsigned olen;
1204
1205 olen = option[IPOPT_OLEN];
1206 if (olen > sizeof(isr->isr_hdr) + sizeof(isr->isr_routes))
1207 return;
1208
1209 mtag = m_tag_get(PACKET_TAG_SRCROUTE, sizeof(*isr), M_NOWAIT);
1210 if (mtag == NULL)
1211 return;
1212 isr = (struct ip_srcrt *)(mtag + 1);
1213
1214 memcpy(isr->isr_hdr, option, olen);
1215 isr->isr_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1216 isr->isr_dst = dst;
1217 m_tag_prepend(m, mtag);
1218 }
1219
1220 /*
1221 * Retrieve incoming source route for use in replies,
1222 * in the same form used by setsockopt.
1223 * The first hop is placed before the options, will be removed later.
1224 */
1225 struct mbuf *
ip_srcroute(struct mbuf * m0)1226 ip_srcroute(struct mbuf *m0)
1227 {
1228 struct in_addr *p, *q;
1229 struct mbuf *m;
1230 struct ip_srcrt *isr;
1231 struct m_tag *mtag;
1232
1233 mtag = m_tag_find(m0, PACKET_TAG_SRCROUTE);
1234 if (mtag == NULL)
1235 return NULL;
1236 isr = (struct ip_srcrt *)(mtag + 1);
1237
1238 if (isr->isr_nhops == 0)
1239 return NULL;
1240
1241 m = m_get(M_DONTWAIT, MT_SOOPTS);
1242 if (m == NULL)
1243 return NULL;
1244
1245 MCLAIM(m, &inetdomain.dom_mowner);
1246 #define OPTSIZ (sizeof(isr->isr_nop) + sizeof(isr->isr_hdr))
1247
1248 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + header) */
1249 m->m_len = (isr->isr_nhops + 1) * sizeof(struct in_addr) + OPTSIZ;
1250
1251 /*
1252 * First save first hop for return route
1253 */
1254 p = &(isr->isr_routes[isr->isr_nhops - 1]);
1255 *(mtod(m, struct in_addr *)) = *p--;
1256
1257 /*
1258 * Copy option fields and padding (nop) to mbuf.
1259 */
1260 isr->isr_nop = IPOPT_NOP;
1261 isr->isr_hdr[IPOPT_OFFSET] = IPOPT_MINOFF;
1262 memmove(mtod(m, char *) + sizeof(struct in_addr), &isr->isr_nop,
1263 OPTSIZ);
1264 q = (struct in_addr *)(mtod(m, char *) +
1265 sizeof(struct in_addr) + OPTSIZ);
1266 #undef OPTSIZ
1267 /*
1268 * Record return path as an IP source route,
1269 * reversing the path (pointers are now aligned).
1270 */
1271 while (p >= isr->isr_routes) {
1272 *q++ = *p--;
1273 }
1274 /*
1275 * Last hop goes to final destination.
1276 */
1277 *q = isr->isr_dst;
1278 m_tag_delete(m0, mtag);
1279 return m;
1280 }
1281
1282 const int inetctlerrmap[PRC_NCMDS] = {
1283 [PRC_MSGSIZE] = EMSGSIZE,
1284 [PRC_HOSTDEAD] = EHOSTDOWN,
1285 [PRC_HOSTUNREACH] = EHOSTUNREACH,
1286 [PRC_UNREACH_NET] = EHOSTUNREACH,
1287 [PRC_UNREACH_HOST] = EHOSTUNREACH,
1288 [PRC_UNREACH_PROTOCOL] = ECONNREFUSED,
1289 [PRC_UNREACH_PORT] = ECONNREFUSED,
1290 [PRC_UNREACH_SRCFAIL] = EHOSTUNREACH,
1291 [PRC_PARAMPROB] = ENOPROTOOPT,
1292 };
1293
1294 void
ip_fasttimo(void)1295 ip_fasttimo(void)
1296 {
1297 if (ip_drainwanted) {
1298 ip_drain();
1299 ip_drainwanted = 0;
1300 }
1301 }
1302
1303 void
ip_drainstub(void)1304 ip_drainstub(void)
1305 {
1306 ip_drainwanted = 1;
1307 }
1308
1309 /*
1310 * Forward a packet. If some error occurs return the sender
1311 * an icmp packet. Note we can't always generate a meaningful
1312 * icmp message because icmp doesn't have a large enough repertoire
1313 * of codes and types.
1314 *
1315 * If not forwarding, just drop the packet. This could be confusing
1316 * if ipforwarding was zero but some routing protocol was advancing
1317 * us as a gateway to somewhere. However, we must let the routing
1318 * protocol deal with that.
1319 *
1320 * The srcrt parameter indicates whether the packet is being forwarded
1321 * via a source route.
1322 */
1323 static void
ip_forward(struct mbuf * m,int srcrt,struct ifnet * rcvif)1324 ip_forward(struct mbuf *m, int srcrt, struct ifnet *rcvif)
1325 {
1326 struct ip *ip = mtod(m, struct ip *);
1327 struct rtentry *rt;
1328 int error, type = 0, code = 0, destmtu = 0;
1329 struct mbuf *mcopy;
1330 n_long dest;
1331 union {
1332 struct sockaddr dst;
1333 struct sockaddr_in dst4;
1334 } u;
1335 net_stat_ref_t ips;
1336 struct route *ro;
1337
1338 KASSERTMSG(cpu_softintr_p(), "ip_forward: not in the software "
1339 "interrupt handler; synchronization assumptions violated");
1340
1341 /*
1342 * We are now in the output path.
1343 */
1344 MCLAIM(m, &ip_tx_mowner);
1345
1346 /*
1347 * Clear any in-bound checksum flags for this packet.
1348 */
1349 m->m_pkthdr.csum_flags = 0;
1350
1351 dest = 0;
1352 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1353 IP_STATINC(IP_STAT_CANTFORWARD);
1354 m_freem(m);
1355 return;
1356 }
1357
1358 if (ip->ip_ttl <= IPTTLDEC) {
1359 IP_STATINC(IP_STAT_TIMXCEED);
1360 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1361 return;
1362 }
1363
1364 sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
1365
1366 ro = rtcache_percpu_getref(ipforward_rt_percpu);
1367 rt = rtcache_lookup(ro, &u.dst);
1368 if (rt == NULL) {
1369 rtcache_percpu_putref(ipforward_rt_percpu);
1370 IP_STATINC(IP_STAT_NOROUTE);
1371 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1372 return;
1373 }
1374
1375 /*
1376 * Save at most 68 bytes of the packet in case
1377 * we need to generate an ICMP message to the src.
1378 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1379 */
1380 mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1381 if (mcopy)
1382 mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1383
1384 ip->ip_ttl -= IPTTLDEC;
1385
1386 /*
1387 * If forwarding packet using same interface that it came in on,
1388 * perhaps should send a redirect to sender to shortcut a hop.
1389 * Only send redirect if source is sending directly to us,
1390 * and if packet was not source routed (or has any options).
1391 * Also, don't send redirect if forwarding using a default route
1392 * or a route modified by a redirect.
1393 */
1394 if (rt->rt_ifp == rcvif &&
1395 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1396 !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) &&
1397 ipsendredirects && !srcrt) {
1398 if ((ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1399 ifatoia(rt->rt_ifa)->ia_subnet) {
1400 if (rt->rt_flags & RTF_GATEWAY)
1401 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1402 else
1403 dest = ip->ip_dst.s_addr;
1404 /*
1405 * Router requirements says to only send host
1406 * redirects.
1407 */
1408 type = ICMP_REDIRECT;
1409 code = ICMP_REDIRECT_HOST;
1410 }
1411 }
1412 rtcache_unref(rt, ro);
1413
1414 error = ip_output(m, NULL, ro,
1415 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1416 NULL, NULL);
1417
1418 if (error) {
1419 IP_STATINC(IP_STAT_CANTFORWARD);
1420 goto error;
1421 }
1422
1423 ips = IP_STAT_GETREF();
1424 _NET_STATINC_REF(ips, IP_STAT_FORWARD);
1425
1426 if (type) {
1427 _NET_STATINC_REF(ips, IP_STAT_REDIRECTSENT);
1428 IP_STAT_PUTREF();
1429 goto redirect;
1430 }
1431
1432 IP_STAT_PUTREF();
1433 if (mcopy) {
1434 #ifdef GATEWAY
1435 if (mcopy->m_flags & M_CANFASTFWD)
1436 ipflow_create(ro, mcopy);
1437 #endif
1438 m_freem(mcopy);
1439 }
1440
1441 rtcache_percpu_putref(ipforward_rt_percpu);
1442 return;
1443
1444 redirect:
1445 error:
1446 if (mcopy == NULL) {
1447 rtcache_percpu_putref(ipforward_rt_percpu);
1448 return;
1449 }
1450
1451 switch (error) {
1452
1453 case 0: /* forwarded, but need redirect */
1454 /* type, code set above */
1455 break;
1456
1457 case ENETUNREACH: /* shouldn't happen, checked above */
1458 case EHOSTUNREACH:
1459 case ENETDOWN:
1460 case EHOSTDOWN:
1461 default:
1462 type = ICMP_UNREACH;
1463 code = ICMP_UNREACH_HOST;
1464 break;
1465
1466 case EMSGSIZE:
1467 type = ICMP_UNREACH;
1468 code = ICMP_UNREACH_NEEDFRAG;
1469
1470 if ((rt = rtcache_validate(ro)) != NULL) {
1471 destmtu = rt->rt_ifp->if_mtu;
1472 rtcache_unref(rt, ro);
1473 }
1474 #ifdef IPSEC
1475 if (ipsec_used)
1476 ipsec_mtu(mcopy, &destmtu);
1477 #endif
1478 IP_STATINC(IP_STAT_CANTFRAG);
1479 break;
1480
1481 case ENOBUFS:
1482 /*
1483 * Do not generate ICMP_SOURCEQUENCH as required in RFC 1812,
1484 * Requirements for IP Version 4 Routers. Source quench can
1485 * be a big problem under DoS attacks or if the underlying
1486 * interface is rate-limited.
1487 */
1488 m_freem(mcopy);
1489 rtcache_percpu_putref(ipforward_rt_percpu);
1490 return;
1491 }
1492 icmp_error(mcopy, type, code, dest, destmtu);
1493 rtcache_percpu_putref(ipforward_rt_percpu);
1494 }
1495
1496 void
ip_savecontrol(struct inpcb * inp,struct mbuf ** mp,struct ip * ip,struct mbuf * m)1497 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1498 struct mbuf *m)
1499 {
1500 struct socket *so = inp->inp_socket;
1501 int inpflags = inp->inp_flags;
1502
1503 if (SOOPT_TIMESTAMP(so->so_options))
1504 mp = sbsavetimestamp(so->so_options, mp);
1505
1506 if (inpflags & INP_RECVDSTADDR) {
1507 *mp = sbcreatecontrol(&ip->ip_dst,
1508 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1509 if (*mp)
1510 mp = &(*mp)->m_next;
1511 }
1512
1513 if (inpflags & INP_RECVTTL) {
1514 *mp = sbcreatecontrol(&ip->ip_ttl,
1515 sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP);
1516 if (*mp)
1517 mp = &(*mp)->m_next;
1518 }
1519
1520 struct psref psref;
1521 ifnet_t *ifp = m_get_rcvif_psref(m, &psref);
1522 if (__predict_false(ifp == NULL)) {
1523 #ifdef DIAGNOSTIC
1524 printf("%s: missing receive interface\n", __func__);
1525 #endif
1526 return; /* XXX should report error? */
1527 }
1528
1529 if (inpflags & INP_RECVPKTINFO) {
1530 struct in_pktinfo ipi;
1531 ipi.ipi_addr = ip->ip_dst;
1532 ipi.ipi_ifindex = ifp->if_index;
1533 *mp = sbcreatecontrol(&ipi,
1534 sizeof(ipi), IP_PKTINFO, IPPROTO_IP);
1535 if (*mp)
1536 mp = &(*mp)->m_next;
1537 }
1538 if (inpflags & INP_RECVIF) {
1539 struct sockaddr_dl sdl;
1540
1541 sockaddr_dl_init(&sdl, sizeof(sdl), ifp->if_index, 0, NULL, 0,
1542 NULL, 0);
1543 *mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP);
1544 if (*mp)
1545 mp = &(*mp)->m_next;
1546 }
1547 m_put_rcvif_psref(ifp, &psref);
1548 }
1549
1550 /*
1551 * sysctl helper routine for net.inet.ip.forwsrcrt.
1552 */
1553 static int
sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)1554 sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
1555 {
1556 int error, tmp;
1557 struct sysctlnode node;
1558
1559 node = *rnode;
1560 tmp = ip_forwsrcrt;
1561 node.sysctl_data = &tmp;
1562 error = sysctl_lookup(SYSCTLFN_CALL(&node));
1563 if (error || newp == NULL)
1564 return (error);
1565
1566 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
1567 0, NULL, NULL, NULL);
1568 if (error)
1569 return (error);
1570
1571 ip_forwsrcrt = tmp;
1572
1573 return (0);
1574 }
1575
1576 /*
1577 * sysctl helper routine for net.inet.ip.mtudisctimeout. checks the
1578 * range of the new value and tweaks timers if it changes.
1579 */
1580 static int
sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)1581 sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1582 {
1583 int error, tmp;
1584 struct sysctlnode node;
1585
1586 icmp_mtudisc_lock();
1587
1588 node = *rnode;
1589 tmp = ip_mtudisc_timeout;
1590 node.sysctl_data = &tmp;
1591 error = sysctl_lookup(SYSCTLFN_CALL(&node));
1592 if (error || newp == NULL)
1593 goto out;
1594 if (tmp < 0) {
1595 error = EINVAL;
1596 goto out;
1597 }
1598
1599 ip_mtudisc_timeout = tmp;
1600 rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
1601 error = 0;
1602 out:
1603 icmp_mtudisc_unlock();
1604 return error;
1605 }
1606
1607 static int
sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)1608 sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)
1609 {
1610
1611 return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS));
1612 }
1613
1614 static void
sysctl_net_inet_ip_setup(struct sysctllog ** clog)1615 sysctl_net_inet_ip_setup(struct sysctllog **clog)
1616 {
1617 const struct sysctlnode *ip_node;
1618
1619 sysctl_createv(clog, 0, NULL, NULL,
1620 CTLFLAG_PERMANENT,
1621 CTLTYPE_NODE, "inet",
1622 SYSCTL_DESCR("PF_INET related settings"),
1623 NULL, 0, NULL, 0,
1624 CTL_NET, PF_INET, CTL_EOL);
1625 sysctl_createv(clog, 0, NULL, &ip_node,
1626 CTLFLAG_PERMANENT,
1627 CTLTYPE_NODE, "ip",
1628 SYSCTL_DESCR("IPv4 related settings"),
1629 NULL, 0, NULL, 0,
1630 CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1631
1632 sysctl_createv(clog, 0, NULL, NULL,
1633 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1634 CTLTYPE_INT, "forwarding",
1635 SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1636 NULL, 0, &ipforwarding, 0,
1637 CTL_NET, PF_INET, IPPROTO_IP,
1638 IPCTL_FORWARDING, CTL_EOL);
1639 sysctl_createv(clog, 0, NULL, NULL,
1640 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1641 CTLTYPE_INT, "redirect",
1642 SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1643 NULL, 0, &ipsendredirects, 0,
1644 CTL_NET, PF_INET, IPPROTO_IP,
1645 IPCTL_SENDREDIRECTS, CTL_EOL);
1646 sysctl_createv(clog, 0, NULL, NULL,
1647 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1648 CTLTYPE_INT, "ttl",
1649 SYSCTL_DESCR("Default TTL for an INET datagram"),
1650 NULL, 0, &ip_defttl, 0,
1651 CTL_NET, PF_INET, IPPROTO_IP,
1652 IPCTL_DEFTTL, CTL_EOL);
1653 sysctl_createv(clog, 0, NULL, NULL,
1654 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1655 CTLTYPE_INT, "forwsrcrt",
1656 SYSCTL_DESCR("Enable forwarding of source-routed "
1657 "datagrams"),
1658 sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1659 CTL_NET, PF_INET, IPPROTO_IP,
1660 IPCTL_FORWSRCRT, CTL_EOL);
1661 sysctl_createv(clog, 0, NULL, NULL,
1662 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1663 CTLTYPE_INT, "directed-broadcast",
1664 SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1665 NULL, 0, &ip_directedbcast, 0,
1666 CTL_NET, PF_INET, IPPROTO_IP,
1667 IPCTL_DIRECTEDBCAST, CTL_EOL);
1668 sysctl_createv(clog, 0, NULL, NULL,
1669 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1670 CTLTYPE_INT, "allowsrcrt",
1671 SYSCTL_DESCR("Accept source-routed datagrams"),
1672 NULL, 0, &ip_allowsrcrt, 0,
1673 CTL_NET, PF_INET, IPPROTO_IP,
1674 IPCTL_ALLOWSRCRT, CTL_EOL);
1675
1676 sysctl_createv(clog, 0, NULL, NULL,
1677 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1678 CTLTYPE_INT, "mtudisc",
1679 SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1680 NULL, 0, &ip_mtudisc, 0,
1681 CTL_NET, PF_INET, IPPROTO_IP,
1682 IPCTL_MTUDISC, CTL_EOL);
1683 sysctl_createv(clog, 0, NULL, NULL,
1684 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1685 CTLTYPE_INT, "anonportmin",
1686 SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1687 sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
1688 CTL_NET, PF_INET, IPPROTO_IP,
1689 IPCTL_ANONPORTMIN, CTL_EOL);
1690 sysctl_createv(clog, 0, NULL, NULL,
1691 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1692 CTLTYPE_INT, "anonportmax",
1693 SYSCTL_DESCR("Highest ephemeral port number to assign"),
1694 sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
1695 CTL_NET, PF_INET, IPPROTO_IP,
1696 IPCTL_ANONPORTMAX, CTL_EOL);
1697 sysctl_createv(clog, 0, NULL, NULL,
1698 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1699 CTLTYPE_INT, "mtudisctimeout",
1700 SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1701 sysctl_net_inet_ip_pmtudto, 0, (void *)&ip_mtudisc_timeout, 0,
1702 CTL_NET, PF_INET, IPPROTO_IP,
1703 IPCTL_MTUDISCTIMEOUT, CTL_EOL);
1704 #ifndef IPNOPRIVPORTS
1705 sysctl_createv(clog, 0, NULL, NULL,
1706 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1707 CTLTYPE_INT, "lowportmin",
1708 SYSCTL_DESCR("Lowest privileged ephemeral port number "
1709 "to assign"),
1710 sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
1711 CTL_NET, PF_INET, IPPROTO_IP,
1712 IPCTL_LOWPORTMIN, CTL_EOL);
1713 sysctl_createv(clog, 0, NULL, NULL,
1714 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1715 CTLTYPE_INT, "lowportmax",
1716 SYSCTL_DESCR("Highest privileged ephemeral port number "
1717 "to assign"),
1718 sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
1719 CTL_NET, PF_INET, IPPROTO_IP,
1720 IPCTL_LOWPORTMAX, CTL_EOL);
1721 #endif /* IPNOPRIVPORTS */
1722 #if NGRE > 0
1723 sysctl_createv(clog, 0, NULL, NULL,
1724 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1725 CTLTYPE_INT, "grettl",
1726 SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1727 NULL, 0, &ip_gre_ttl, 0,
1728 CTL_NET, PF_INET, IPPROTO_IP,
1729 IPCTL_GRE_TTL, CTL_EOL);
1730 #endif /* NGRE */
1731 sysctl_createv(clog, 0, NULL, NULL,
1732 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1733 CTLTYPE_INT, "checkinterface",
1734 SYSCTL_DESCR("Enable receive side of Strong ES model "
1735 "from RFC1122"),
1736 NULL, 0, &ip_checkinterface, 0,
1737 CTL_NET, PF_INET, IPPROTO_IP,
1738 IPCTL_CHECKINTERFACE, CTL_EOL);
1739
1740 pktq_sysctl_setup(ip_pktq, clog, ip_node, IPCTL_IFQ);
1741
1742 sysctl_createv(clog, 0, NULL, NULL,
1743 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1744 CTLTYPE_INT, "random_id",
1745 SYSCTL_DESCR("Assign random ip_id values"),
1746 NULL, 0, &ip_do_randomid, 0,
1747 CTL_NET, PF_INET, IPPROTO_IP,
1748 IPCTL_RANDOMID, CTL_EOL);
1749 sysctl_createv(clog, 0, NULL, NULL,
1750 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1751 CTLTYPE_INT, "do_loopback_cksum",
1752 SYSCTL_DESCR("Perform IP checksum on loopback"),
1753 NULL, 0, &ip_do_loopback_cksum, 0,
1754 CTL_NET, PF_INET, IPPROTO_IP,
1755 IPCTL_LOOPBACKCKSUM, CTL_EOL);
1756 sysctl_createv(clog, 0, NULL, NULL,
1757 CTLFLAG_PERMANENT,
1758 CTLTYPE_STRUCT, "stats",
1759 SYSCTL_DESCR("IP statistics"),
1760 sysctl_net_inet_ip_stats, 0, NULL, 0,
1761 CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
1762 CTL_EOL);
1763 #if NARP
1764 sysctl_createv(clog, 0, NULL, NULL,
1765 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1766 CTLTYPE_INT, "dad_count",
1767 SYSCTL_DESCR("Number of Duplicate Address Detection "
1768 "probes to send"),
1769 NULL, 0, &ip_dad_count, 0,
1770 CTL_NET, PF_INET, IPPROTO_IP,
1771 IPCTL_DAD_COUNT, CTL_EOL);
1772 #endif
1773
1774 /* anonportalgo RFC6056 subtree */
1775 const struct sysctlnode *portalgo_node;
1776 sysctl_createv(clog, 0, NULL, &portalgo_node,
1777 CTLFLAG_PERMANENT,
1778 CTLTYPE_NODE, "anonportalgo",
1779 SYSCTL_DESCR("Anonymous Port Algorithm Selection (RFC 6056)"),
1780 NULL, 0, NULL, 0,
1781 CTL_NET, PF_INET, IPPROTO_IP, CTL_CREATE, CTL_EOL);
1782 sysctl_createv(clog, 0, &portalgo_node, NULL,
1783 CTLFLAG_PERMANENT,
1784 CTLTYPE_STRING, "available",
1785 SYSCTL_DESCR("available algorithms"),
1786 sysctl_portalgo_available, 0, NULL, PORTALGO_MAXLEN,
1787 CTL_CREATE, CTL_EOL);
1788 sysctl_createv(clog, 0, &portalgo_node, NULL,
1789 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1790 CTLTYPE_STRING, "selected",
1791 SYSCTL_DESCR("selected algorithm"),
1792 sysctl_portalgo_selected4, 0, NULL, PORTALGO_MAXLEN,
1793 CTL_CREATE, CTL_EOL);
1794 sysctl_createv(clog, 0, &portalgo_node, NULL,
1795 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1796 CTLTYPE_STRUCT, "reserve",
1797 SYSCTL_DESCR("bitmap of reserved ports"),
1798 sysctl_portalgo_reserve4, 0, NULL, 0,
1799 CTL_CREATE, CTL_EOL);
1800 }
1801
1802 void
ip_statinc(u_int stat)1803 ip_statinc(u_int stat)
1804 {
1805
1806 KASSERT(stat < IP_NSTATS);
1807 IP_STATINC(stat);
1808 }
1809