ip_input.c revision 1.368 1 /* $NetBSD: ip_input.c,v 1.368 2018/02/05 13:52:39 maxv 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 1.368 2018/02/05 13:52:39 maxv 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 /* GATEWAY */
157 #define IPFORWARDING 0 /* don't forward IP packets not for us */
158 #endif /* GATEWAY */
159 #endif /* IPFORWARDING */
160 #ifndef IPSENDREDIRECTS
161 #define IPSENDREDIRECTS 1
162 #endif
163 #ifndef IPFORWSRCRT
164 #define IPFORWSRCRT 0 /* forward source-routed packets */
165 #endif
166 #ifndef IPALLOWSRCRT
167 #define IPALLOWSRCRT 0 /* allow source-routed packets */
168 #endif
169 #ifndef IPMTUDISC
170 #define IPMTUDISC 1
171 #endif
172 #ifndef IPMTUDISCTIMEOUT
173 #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
174 #endif
175
176 /*
177 * Note: DIRECTED_BROADCAST is handled this way so that previous
178 * configuration using this option will Just Work.
179 */
180 #ifndef IPDIRECTEDBCAST
181 #ifdef DIRECTED_BROADCAST
182 #define IPDIRECTEDBCAST 1
183 #else
184 #define IPDIRECTEDBCAST 0
185 #endif /* DIRECTED_BROADCAST */
186 #endif /* IPDIRECTEDBCAST */
187 int ipforwarding = IPFORWARDING;
188 int ipsendredirects = IPSENDREDIRECTS;
189 int ip_defttl = IPDEFTTL;
190 int ip_forwsrcrt = IPFORWSRCRT;
191 int ip_directedbcast = IPDIRECTEDBCAST;
192 int ip_allowsrcrt = IPALLOWSRCRT;
193 int ip_mtudisc = IPMTUDISC;
194 int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
195
196 int ip_do_randomid = 0;
197
198 /*
199 * XXX - Setting ip_checkinterface mostly implements the receive side of
200 * the Strong ES model described in RFC 1122, but since the routing table
201 * and transmit implementation do not implement the Strong ES model,
202 * setting this to 1 results in an odd hybrid.
203 *
204 * XXX - ip_checkinterface currently must be disabled if you use ipnat
205 * to translate the destination address to another local interface.
206 *
207 * XXX - ip_checkinterface must be disabled if you add IP aliases
208 * to the loopback interface instead of the interface where the
209 * packets for those addresses are received.
210 */
211 static int ip_checkinterface __read_mostly = 0;
212
213 struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
214
215 pktqueue_t * ip_pktq __read_mostly;
216 pfil_head_t * inet_pfil_hook __read_mostly;
217 ipid_state_t * ip_ids __read_mostly;
218 percpu_t * ipstat_percpu __read_mostly;
219
220 static percpu_t *ipforward_rt_percpu __cacheline_aligned;
221
222 uint16_t ip_id;
223
224 #ifdef INET_CSUM_COUNTERS
225 #include <sys/device.h>
226
227 struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
228 NULL, "inet", "hwcsum bad");
229 struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
230 NULL, "inet", "hwcsum ok");
231 struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
232 NULL, "inet", "swcsum");
233
234 #define INET_CSUM_COUNTER_INCR(ev) (ev)->ev_count++
235
236 EVCNT_ATTACH_STATIC(ip_hwcsum_bad);
237 EVCNT_ATTACH_STATIC(ip_hwcsum_ok);
238 EVCNT_ATTACH_STATIC(ip_swcsum);
239
240 #else
241
242 #define INET_CSUM_COUNTER_INCR(ev) /* nothing */
243
244 #endif /* INET_CSUM_COUNTERS */
245
246 /*
247 * Used to save the IP options in case a protocol wants to respond
248 * to an incoming packet over the same route if the packet got here
249 * using IP source routing. This allows connection establishment and
250 * maintenance when the remote end is on a network that is not known
251 * to us.
252 */
253 struct ip_srcrt {
254 int isr_nhops; /* number of hops */
255 struct in_addr isr_dst; /* final destination */
256 char isr_nop; /* one NOP to align */
257 char isr_hdr[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN & OFFSET */
258 struct in_addr isr_routes[MAX_IPOPTLEN/sizeof(struct in_addr)];
259 };
260
261 static int ip_drainwanted;
262
263 static void save_rte(struct mbuf *, u_char *, struct in_addr);
264
265 #ifdef MBUFTRACE
266 struct mowner ip_rx_mowner = MOWNER_INIT("internet", "rx");
267 struct mowner ip_tx_mowner = MOWNER_INIT("internet", "tx");
268 #endif
269
270 static void ipintr(void *);
271 static void ip_input(struct mbuf *);
272 static void ip_forward(struct mbuf *, int, struct ifnet *);
273 static bool ip_dooptions(struct mbuf *);
274 static struct in_ifaddr *ip_rtaddr(struct in_addr, struct psref *);
275 static void sysctl_net_inet_ip_setup(struct sysctllog **);
276
277 static struct in_ifaddr *ip_match_our_address(struct ifnet *, struct ip *,
278 int *);
279 static struct in_ifaddr *ip_match_our_address_broadcast(struct ifnet *,
280 struct ip *);
281
282 #ifdef NET_MPSAFE
283 #define SOFTNET_LOCK() mutex_enter(softnet_lock)
284 #define SOFTNET_UNLOCK() mutex_exit(softnet_lock)
285 #else
286 #define SOFTNET_LOCK() KASSERT(mutex_owned(softnet_lock))
287 #define SOFTNET_UNLOCK() KASSERT(mutex_owned(softnet_lock))
288 #endif
289
290 /*
291 * IP initialization: fill in IP protocol switch table.
292 * All protocols not implemented in kernel go to raw IP protocol handler.
293 */
294 void
295 ip_init(void)
296 {
297 const struct protosw *pr;
298
299 in_init();
300 sysctl_net_inet_ip_setup(NULL);
301
302 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
303 KASSERT(pr != NULL);
304
305 ip_pktq = pktq_create(IFQ_MAXLEN, ipintr, NULL);
306 KASSERT(ip_pktq != NULL);
307
308 for (u_int i = 0; i < IPPROTO_MAX; i++) {
309 ip_protox[i] = pr - inetsw;
310 }
311 for (pr = inetdomain.dom_protosw;
312 pr < inetdomain.dom_protoswNPROTOSW; pr++)
313 if (pr->pr_domain->dom_family == PF_INET &&
314 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
315 ip_protox[pr->pr_protocol] = pr - inetsw;
316
317 ip_reass_init();
318
319 ip_ids = ip_id_init();
320 ip_id = time_uptime & 0xfffff;
321
322 #ifdef GATEWAY
323 ipflow_init();
324 #endif
325
326 /* Register our Packet Filter hook. */
327 inet_pfil_hook = pfil_head_create(PFIL_TYPE_AF, (void *)AF_INET);
328 KASSERT(inet_pfil_hook != NULL);
329
330 #ifdef MBUFTRACE
331 MOWNER_ATTACH(&ip_tx_mowner);
332 MOWNER_ATTACH(&ip_rx_mowner);
333 #endif /* MBUFTRACE */
334
335 ipstat_percpu = percpu_alloc(sizeof(uint64_t) * IP_NSTATS);
336 ipforward_rt_percpu = percpu_alloc(sizeof(struct route));
337 ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
338 }
339
340 static struct in_ifaddr *
341 ip_match_our_address(struct ifnet *ifp, struct ip *ip, int *downmatch)
342 {
343 struct in_ifaddr *ia = NULL;
344 int checkif;
345
346 /*
347 * Enable a consistency check between the destination address
348 * and the arrival interface for a unicast packet (the RFC 1122
349 * strong ES model) if IP forwarding is disabled and the packet
350 * is not locally generated.
351 *
352 * XXX - Checking also should be disabled if the destination
353 * address is ipnat'ed to a different interface.
354 *
355 * XXX - Checking is incompatible with IP aliases added
356 * to the loopback interface instead of the interface where
357 * the packets are received.
358 *
359 * XXX - We need to add a per ifaddr flag for this so that
360 * we get finer grain control.
361 */
362 checkif = ip_checkinterface && (ipforwarding == 0) &&
363 (ifp->if_flags & IFF_LOOPBACK) == 0;
364
365 IN_ADDRHASH_READER_FOREACH(ia, ip->ip_dst.s_addr) {
366 if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
367 if (ia->ia4_flags & IN_IFF_NOTREADY)
368 continue;
369 if (checkif && ia->ia_ifp != ifp)
370 continue;
371 if ((ia->ia_ifp->if_flags & IFF_UP) == 0) {
372 (*downmatch)++;
373 continue;
374 }
375 if (ia->ia4_flags & IN_IFF_DETACHED &&
376 (ifp->if_flags & IFF_LOOPBACK) == 0)
377 continue;
378 break;
379 }
380 }
381
382 return ia;
383 }
384
385 static struct in_ifaddr *
386 ip_match_our_address_broadcast(struct ifnet *ifp, struct ip *ip)
387 {
388 struct in_ifaddr *ia = NULL;
389 struct ifaddr *ifa;
390
391 IFADDR_READER_FOREACH(ifa, ifp) {
392 if (ifa->ifa_addr->sa_family != AF_INET)
393 continue;
394 ia = ifatoia(ifa);
395 if (ia->ia4_flags & IN_IFF_NOTREADY)
396 continue;
397 if (ia->ia4_flags & IN_IFF_DETACHED &&
398 (ifp->if_flags & IFF_LOOPBACK) == 0)
399 continue;
400 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
401 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
402 /*
403 * Look for all-0's host part (old broadcast addr),
404 * either for subnet or net.
405 */
406 ip->ip_dst.s_addr == ia->ia_subnet ||
407 ip->ip_dst.s_addr == ia->ia_net)
408 goto matched;
409 /*
410 * An interface with IP address zero accepts
411 * all packets that arrive on that interface.
412 */
413 if (in_nullhost(ia->ia_addr.sin_addr))
414 goto matched;
415 }
416 ia = NULL;
417
418 matched:
419 return ia;
420 }
421
422 /*
423 * IP software interrupt routine.
424 */
425 static void
426 ipintr(void *arg __unused)
427 {
428 struct mbuf *m;
429
430 KASSERT(cpu_softintr_p());
431
432 SOFTNET_LOCK_UNLESS_NET_MPSAFE();
433 while ((m = pktq_dequeue(ip_pktq)) != NULL) {
434 ip_input(m);
435 }
436 SOFTNET_UNLOCK_UNLESS_NET_MPSAFE();
437 }
438
439 /*
440 * IP input routine. Checksum and byte swap header. If fragmented
441 * try to reassemble. Process options. Pass to next level.
442 */
443 static void
444 ip_input(struct mbuf *m)
445 {
446 struct ip *ip = NULL;
447 struct in_ifaddr *ia = NULL;
448 int hlen = 0, len;
449 int downmatch;
450 int srcrt = 0;
451 ifnet_t *ifp;
452 struct psref psref;
453 int s;
454
455 KASSERTMSG(cpu_softintr_p(), "ip_input: not in the software "
456 "interrupt handler; synchronization assumptions violated");
457
458 MCLAIM(m, &ip_rx_mowner);
459 KASSERT((m->m_flags & M_PKTHDR) != 0);
460
461 ifp = m_get_rcvif_psref(m, &psref);
462 if (__predict_false(ifp == NULL))
463 goto out;
464
465 /*
466 * If no IP addresses have been set yet but the interfaces
467 * are receiving, can't do anything with incoming packets yet.
468 * Note: we pre-check without locks held.
469 */
470 if (IN_ADDRLIST_READER_EMPTY())
471 goto out;
472 IP_STATINC(IP_STAT_TOTAL);
473
474 /*
475 * If the IP header is not aligned, slurp it up into a new
476 * mbuf with space for link headers, in the event we forward
477 * it. Otherwise, if it is aligned, make sure the entire
478 * base IP header is in the first mbuf of the chain.
479 */
480 if (IP_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
481 if ((m = m_copyup(m, sizeof(struct ip),
482 (max_linkhdr + 3) & ~3)) == NULL) {
483 /* XXXJRT new stat, please */
484 IP_STATINC(IP_STAT_TOOSMALL);
485 goto out;
486 }
487 } else if (__predict_false(m->m_len < sizeof(struct ip))) {
488 if ((m = m_pullup(m, sizeof(struct ip))) == NULL) {
489 IP_STATINC(IP_STAT_TOOSMALL);
490 goto out;
491 }
492 }
493 ip = mtod(m, struct ip *);
494 if (ip->ip_v != IPVERSION) {
495 IP_STATINC(IP_STAT_BADVERS);
496 goto out;
497 }
498 hlen = ip->ip_hl << 2;
499 if (hlen < sizeof(struct ip)) { /* minimum header length */
500 IP_STATINC(IP_STAT_BADHLEN);
501 goto out;
502 }
503 if (hlen > m->m_len) {
504 if ((m = m_pullup(m, hlen)) == NULL) {
505 IP_STATINC(IP_STAT_BADHLEN);
506 goto out;
507 }
508 ip = mtod(m, struct ip *);
509 }
510
511 /*
512 * RFC1122: packets with a multicast source address are
513 * not allowed.
514 */
515 if (IN_MULTICAST(ip->ip_src.s_addr)) {
516 IP_STATINC(IP_STAT_BADADDR);
517 goto out;
518 }
519
520 /* 127/8 must not appear on wire - RFC1122 */
521 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
522 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
523 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
524 IP_STATINC(IP_STAT_BADADDR);
525 goto out;
526 }
527 }
528
529 switch (m->m_pkthdr.csum_flags &
530 ((ifp->if_csum_flags_rx & M_CSUM_IPv4) | M_CSUM_IPv4_BAD)) {
531 case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
532 INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
533 IP_STATINC(IP_STAT_BADSUM);
534 goto out;
535
536 case M_CSUM_IPv4:
537 /* Checksum was okay. */
538 INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
539 break;
540
541 default:
542 /*
543 * Must compute it ourselves. Maybe skip checksum on
544 * loopback interfaces.
545 */
546 if (__predict_true(!(ifp->if_flags & IFF_LOOPBACK) ||
547 ip_do_loopback_cksum)) {
548 INET_CSUM_COUNTER_INCR(&ip_swcsum);
549 if (in_cksum(m, hlen) != 0) {
550 IP_STATINC(IP_STAT_BADSUM);
551 goto out;
552 }
553 }
554 break;
555 }
556
557 /* Retrieve the packet length. */
558 len = ntohs(ip->ip_len);
559
560 /*
561 * Check for additional length bogosity
562 */
563 if (len < hlen) {
564 IP_STATINC(IP_STAT_BADLEN);
565 goto out;
566 }
567
568 /*
569 * Check that the amount of data in the buffers is at least as much
570 * as the IP header would have us expect. Trim mbufs if longer than
571 * we expect. Drop packet if shorter than we expect.
572 */
573 if (m->m_pkthdr.len < len) {
574 IP_STATINC(IP_STAT_TOOSHORT);
575 goto out;
576 }
577 if (m->m_pkthdr.len > len) {
578 if (m->m_len == m->m_pkthdr.len) {
579 m->m_len = len;
580 m->m_pkthdr.len = len;
581 } else
582 m_adj(m, len - m->m_pkthdr.len);
583 }
584
585 /*
586 * Assume that we can create a fast-forward IP flow entry
587 * based on this packet.
588 */
589 m->m_flags |= M_CANFASTFWD;
590
591 /*
592 * Run through list of hooks for input packets. If there are any
593 * filters which require that additional packets in the flow are
594 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
595 * Note that filters must _never_ set this flag, as another filter
596 * in the list may have previously cleared it.
597 */
598 #if defined(IPSEC)
599 if (!ipsec_used || !ipsec_indone(m))
600 #else
601 if (1)
602 #endif
603 {
604 struct in_addr odst = ip->ip_dst;
605 bool freed;
606
607 freed = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_IN) != 0;
608 if (freed || m == NULL) {
609 m = NULL;
610 goto out;
611 }
612 ip = mtod(m, struct ip *);
613 hlen = ip->ip_hl << 2;
614
615 /*
616 * XXX The setting of "srcrt" here is to prevent ip_forward()
617 * from generating ICMP redirects for packets that have
618 * been redirected by a hook back out on to the same LAN that
619 * they came from and is not an indication that the packet
620 * is being inffluenced by source routing options. This
621 * allows things like
622 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp"
623 * where tlp0 is both on the 1.1.1.0/24 network and is the
624 * default route for hosts on 1.1.1.0/24. Of course this
625 * also requires a "map tlp0 ..." to complete the story.
626 * One might argue whether or not this kind of network config.
627 * should be supported in this manner...
628 */
629 srcrt = (odst.s_addr != ip->ip_dst.s_addr);
630 }
631
632 #ifdef ALTQ
633 /* XXX Temporary until ALTQ is changed to use a pfil hook */
634 if (altq_input) {
635 SOFTNET_LOCK();
636 if ((*altq_input)(m, AF_INET) == 0) {
637 /* Packet dropped by traffic conditioner. */
638 SOFTNET_UNLOCK();
639 m = NULL;
640 goto out;
641 }
642 SOFTNET_UNLOCK();
643 }
644 #endif
645
646 /*
647 * Process options and, if not destined for us,
648 * ship it on. ip_dooptions returns 1 when an
649 * error was detected (causing an icmp message
650 * to be sent and the original packet to be freed).
651 */
652 if (hlen > sizeof(struct ip) && ip_dooptions(m)) {
653 m = NULL;
654 goto out;
655 }
656
657 /*
658 * Check our list of addresses, to see if the packet is for us.
659 *
660 * Traditional 4.4BSD did not consult IFF_UP at all.
661 * The behavior here is to treat addresses on !IFF_UP interface
662 * or IN_IFF_NOTREADY addresses as not mine.
663 */
664 downmatch = 0;
665 s = pserialize_read_enter();
666 ia = ip_match_our_address(ifp, ip, &downmatch);
667 if (ia != NULL) {
668 pserialize_read_exit(s);
669 goto ours;
670 }
671
672 if (ifp->if_flags & IFF_BROADCAST) {
673 ia = ip_match_our_address_broadcast(ifp, ip);
674 if (ia != NULL) {
675 pserialize_read_exit(s);
676 goto ours;
677 }
678 }
679 pserialize_read_exit(s);
680
681 if (IN_MULTICAST(ip->ip_dst.s_addr)) {
682 #ifdef MROUTING
683 extern struct socket *ip_mrouter;
684
685 if (ip_mrouter) {
686 /*
687 * If we are acting as a multicast router, all
688 * incoming multicast packets are passed to the
689 * kernel-level multicast forwarding function.
690 * The packet is returned (relatively) intact; if
691 * ip_mforward() returns a non-zero value, the packet
692 * must be discarded, else it may be accepted below.
693 *
694 * (The IP ident field is put in the same byte order
695 * as expected when ip_mforward() is called from
696 * ip_output().)
697 */
698 SOFTNET_LOCK();
699 if (ip_mforward(m, ifp) != 0) {
700 SOFTNET_UNLOCK();
701 IP_STATINC(IP_STAT_CANTFORWARD);
702 goto out;
703 }
704 SOFTNET_UNLOCK();
705
706 /*
707 * The process-level routing demon needs to receive
708 * all multicast IGMP packets, whether or not this
709 * host belongs to their destination groups.
710 */
711 if (ip->ip_p == IPPROTO_IGMP) {
712 goto ours;
713 }
714 IP_STATINC(IP_STAT_CANTFORWARD);
715 }
716 #endif
717 /*
718 * See if we belong to the destination multicast group on the
719 * arrival interface.
720 */
721 if (!in_multi_group(ip->ip_dst, ifp, 0)) {
722 IP_STATINC(IP_STAT_CANTFORWARD);
723 goto out;
724 }
725 goto ours;
726 }
727 if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
728 in_nullhost(ip->ip_dst))
729 goto ours;
730
731 /*
732 * Not for us; forward if possible and desirable.
733 */
734 if (ipforwarding == 0) {
735 m_put_rcvif_psref(ifp, &psref);
736 IP_STATINC(IP_STAT_CANTFORWARD);
737 m_freem(m);
738 } else {
739 /*
740 * If ip_dst matched any of my address on !IFF_UP interface,
741 * and there's no IFF_UP interface that matches ip_dst,
742 * send icmp unreach. Forwarding it will result in in-kernel
743 * forwarding loop till TTL goes to 0.
744 */
745 if (downmatch) {
746 m_put_rcvif_psref(ifp, &psref);
747 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
748 IP_STATINC(IP_STAT_CANTFORWARD);
749 return;
750 }
751 #ifdef IPSEC
752 /* Check the security policy (SP) for the packet */
753 if (ipsec_used) {
754 if (ipsec4_input(m, IP_FORWARDING |
755 (ip_directedbcast ? IP_ALLOWBROADCAST : 0)) != 0) {
756 goto out;
757 }
758 }
759 #endif
760 ip_forward(m, srcrt, ifp);
761 m_put_rcvif_psref(ifp, &psref);
762 }
763 return;
764
765 ours:
766 m_put_rcvif_psref(ifp, &psref);
767 ifp = NULL;
768
769 /*
770 * If offset or IP_MF are set, must reassemble.
771 */
772 if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
773 /*
774 * Pass to IP reassembly mechanism.
775 */
776 if (ip_reass_packet(&m, ip) != 0) {
777 /* Failed; invalid fragment(s) or packet. */
778 goto out;
779 }
780 if (m == NULL) {
781 /* More fragments should come; silently return. */
782 goto out;
783 }
784 /*
785 * Reassembly is done, we have the final packet.
786 * Update cached data in local variable(s).
787 */
788 ip = mtod(m, struct ip *);
789 hlen = ip->ip_hl << 2;
790 }
791
792 #ifdef IPSEC
793 /*
794 * Enforce IPsec policy checking if we are seeing last header.
795 * Note that we do not visit this with protocols with PCB layer
796 * code - like UDP/TCP/raw IP.
797 */
798 if (ipsec_used &&
799 (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
800 if (ipsec4_input(m, 0) != 0) {
801 goto out;
802 }
803 }
804 #endif
805
806 /*
807 * Switch out to protocol's input routine.
808 */
809 #if IFA_STATS
810 if (ia && ip) {
811 struct in_ifaddr *_ia;
812 /*
813 * Keep a reference from ip_match_our_address with psref
814 * is expensive, so explore ia here again.
815 */
816 s = pserialize_read_enter();
817 _ia = in_get_ia(ip->ip_dst);
818 _ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
819 pserialize_read_exit(s);
820 }
821 #endif
822 IP_STATINC(IP_STAT_DELIVERED);
823
824 const int off = hlen, nh = ip->ip_p;
825
826 (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
827 return;
828
829 out:
830 m_put_rcvif_psref(ifp, &psref);
831 if (m != NULL)
832 m_freem(m);
833 }
834
835 /*
836 * IP timer processing.
837 */
838 void
839 ip_slowtimo(void)
840 {
841
842 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE();
843
844 ip_reass_slowtimo();
845
846 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
847 }
848
849 /*
850 * IP drain processing.
851 */
852 void
853 ip_drain(void)
854 {
855
856 KERNEL_LOCK(1, NULL);
857 ip_reass_drain();
858 KERNEL_UNLOCK_ONE(NULL);
859 }
860
861 /*
862 * ip_dooptions: perform option processing on a datagram, possibly discarding
863 * it if bad options are encountered, or forwarding it if source-routed.
864 *
865 * => Returns true if packet has been forwarded/freed.
866 * => Returns false if the packet should be processed further.
867 */
868 static bool
869 ip_dooptions(struct mbuf *m)
870 {
871 struct ip *ip = mtod(m, struct ip *);
872 u_char *cp, *cp0;
873 struct ip_timestamp *ipt;
874 struct in_ifaddr *ia;
875 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
876 int lsrr_present, ssrr_present, rr_present, ts_present;
877 struct in_addr dst;
878 n_time ntime;
879 struct ifaddr *ifa = NULL;
880 int s;
881
882 lsrr_present = 0;
883 ssrr_present = 0;
884 rr_present = 0;
885 ts_present = 0;
886
887 dst = ip->ip_dst;
888 cp = (u_char *)(ip + 1);
889 cnt = (ip->ip_hl << 2) - sizeof(struct ip);
890 for (; cnt > 0; cnt -= optlen, cp += optlen) {
891 opt = cp[IPOPT_OPTVAL];
892 if (opt == IPOPT_EOL)
893 break;
894 if (opt == IPOPT_NOP)
895 optlen = 1;
896 else {
897 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
898 code = &cp[IPOPT_OLEN] - (u_char *)ip;
899 goto bad;
900 }
901 optlen = cp[IPOPT_OLEN];
902 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
903 code = &cp[IPOPT_OLEN] - (u_char *)ip;
904 goto bad;
905 }
906 }
907 switch (opt) {
908
909 default:
910 break;
911
912 /*
913 * Source routing with record.
914 * Find interface with current destination address.
915 * If none on this machine then drop if strictly routed,
916 * or do nothing if loosely routed.
917 * Record interface address and bring up next address
918 * component. If strictly routed make sure next
919 * address is on directly accessible net.
920 */
921 case IPOPT_LSRR:
922 case IPOPT_SSRR: {
923 struct psref psref;
924 struct sockaddr_in ipaddr = {
925 .sin_len = sizeof(ipaddr),
926 .sin_family = AF_INET,
927 };
928
929 if (ip_allowsrcrt == 0) {
930 type = ICMP_UNREACH;
931 code = ICMP_UNREACH_NET_PROHIB;
932 goto bad;
933 }
934 if (opt == IPOPT_LSRR) {
935 if (lsrr_present++) {
936 code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
937 goto bad;
938 }
939 } else {
940 if (ssrr_present++) {
941 code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
942 goto bad;
943 }
944 }
945 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
946 code = &cp[IPOPT_OLEN] - (u_char *)ip;
947 goto bad;
948 }
949 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
950 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
951 goto bad;
952 }
953 ipaddr.sin_addr = ip->ip_dst;
954
955 s = pserialize_read_enter();
956 ifa = ifa_ifwithaddr(sintosa(&ipaddr));
957 if (ifa == NULL) {
958 pserialize_read_exit(s);
959 if (opt == IPOPT_SSRR) {
960 type = ICMP_UNREACH;
961 code = ICMP_UNREACH_SRCFAIL;
962 goto bad;
963 }
964 /*
965 * Loose routing, and not at next destination
966 * yet; nothing to do except forward.
967 */
968 break;
969 }
970 pserialize_read_exit(s);
971
972 off--; /* 0 origin */
973 if ((off + sizeof(struct in_addr)) > optlen) {
974 /*
975 * End of source route. Should be for us.
976 */
977 save_rte(m, cp, ip->ip_src);
978 break;
979 }
980 /*
981 * locate outgoing interface
982 */
983 memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off),
984 sizeof(ipaddr.sin_addr));
985 if (opt == IPOPT_SSRR) {
986 ifa = ifa_ifwithladdr_psref(sintosa(&ipaddr),
987 &psref);
988 if (ifa != NULL)
989 ia = ifatoia(ifa);
990 else
991 ia = NULL;
992 } else {
993 ia = ip_rtaddr(ipaddr.sin_addr, &psref);
994 }
995 if (ia == NULL) {
996 type = ICMP_UNREACH;
997 code = ICMP_UNREACH_SRCFAIL;
998 goto bad;
999 }
1000 ip->ip_dst = ipaddr.sin_addr;
1001 bcopy((void *)&ia->ia_addr.sin_addr,
1002 (void *)(cp + off), sizeof(struct in_addr));
1003 ia4_release(ia, &psref);
1004 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1005 /*
1006 * Let ip_intr's mcast routing check handle mcast pkts
1007 */
1008 forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1009 break;
1010 }
1011
1012 case IPOPT_RR: {
1013 struct psref psref;
1014 struct sockaddr_in ipaddr = {
1015 .sin_len = sizeof(ipaddr),
1016 .sin_family = AF_INET,
1017 };
1018
1019 if (rr_present++) {
1020 code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
1021 goto bad;
1022 }
1023 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1024 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1025 goto bad;
1026 }
1027 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1028 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1029 goto bad;
1030 }
1031 /*
1032 * If no space remains, ignore.
1033 */
1034 off--; /* 0 origin */
1035 if ((off + sizeof(struct in_addr)) > optlen)
1036 break;
1037 memcpy((void *)&ipaddr.sin_addr, (void *)(&ip->ip_dst),
1038 sizeof(ipaddr.sin_addr));
1039 /*
1040 * locate outgoing interface; if we're the destination,
1041 * use the incoming interface (should be same).
1042 */
1043 ifa = ifa_ifwithaddr_psref(sintosa(&ipaddr), &psref);
1044 if (ifa == NULL) {
1045 ia = ip_rtaddr(ipaddr.sin_addr, &psref);
1046 if (ia == NULL) {
1047 type = ICMP_UNREACH;
1048 code = ICMP_UNREACH_HOST;
1049 goto bad;
1050 }
1051 } else {
1052 ia = ifatoia(ifa);
1053 }
1054 bcopy((void *)&ia->ia_addr.sin_addr,
1055 (void *)(cp + off), sizeof(struct in_addr));
1056 ia4_release(ia, &psref);
1057 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1058 break;
1059 }
1060
1061 case IPOPT_TS:
1062 code = cp - (u_char *)ip;
1063 ipt = (struct ip_timestamp *)cp;
1064 if (ts_present++) {
1065 code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
1066 goto bad;
1067 }
1068 if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1069 code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1070 goto bad;
1071 }
1072 if (ipt->ipt_ptr < 5) {
1073 code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1074 goto bad;
1075 }
1076 if (ipt->ipt_ptr > ipt->ipt_len - sizeof(int32_t)) {
1077 if (++ipt->ipt_oflw == 0) {
1078 code = (u_char *)&ipt->ipt_ptr -
1079 (u_char *)ip;
1080 goto bad;
1081 }
1082 break;
1083 }
1084 cp0 = (cp + ipt->ipt_ptr - 1);
1085 switch (ipt->ipt_flg) {
1086
1087 case IPOPT_TS_TSONLY:
1088 break;
1089
1090 case IPOPT_TS_TSANDADDR: {
1091 struct ifnet *rcvif;
1092 int _s, _ss;
1093 struct sockaddr_in ipaddr = {
1094 .sin_len = sizeof(ipaddr),
1095 .sin_family = AF_INET,
1096 };
1097
1098 if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1099 sizeof(struct in_addr) > ipt->ipt_len) {
1100 code = (u_char *)&ipt->ipt_ptr -
1101 (u_char *)ip;
1102 goto bad;
1103 }
1104 ipaddr.sin_addr = dst;
1105 _ss = pserialize_read_enter();
1106 rcvif = m_get_rcvif(m, &_s);
1107 if (__predict_true(rcvif != NULL)) {
1108 ifa = ifaof_ifpforaddr(sintosa(&ipaddr),
1109 rcvif);
1110 }
1111 m_put_rcvif(rcvif, &_s);
1112 if (ifa == NULL) {
1113 pserialize_read_exit(_ss);
1114 break;
1115 }
1116 ia = ifatoia(ifa);
1117 bcopy(&ia->ia_addr.sin_addr,
1118 cp0, sizeof(struct in_addr));
1119 pserialize_read_exit(_ss);
1120 ipt->ipt_ptr += sizeof(struct in_addr);
1121 break;
1122 }
1123
1124 case IPOPT_TS_PRESPEC: {
1125 struct sockaddr_in ipaddr = {
1126 .sin_len = sizeof(ipaddr),
1127 .sin_family = AF_INET,
1128 };
1129
1130 if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1131 sizeof(struct in_addr) > ipt->ipt_len) {
1132 code = (u_char *)&ipt->ipt_ptr -
1133 (u_char *)ip;
1134 goto bad;
1135 }
1136 memcpy(&ipaddr.sin_addr, cp0,
1137 sizeof(struct in_addr));
1138 s = pserialize_read_enter();
1139 ifa = ifa_ifwithaddr(sintosa(&ipaddr));
1140 if (ifa == NULL) {
1141 pserialize_read_exit(s);
1142 continue;
1143 }
1144 pserialize_read_exit(s);
1145 ipt->ipt_ptr += sizeof(struct in_addr);
1146 break;
1147 }
1148
1149 default:
1150 /* XXX can't take &ipt->ipt_flg */
1151 code = (u_char *)&ipt->ipt_ptr -
1152 (u_char *)ip + 1;
1153 goto bad;
1154 }
1155 ntime = iptime();
1156 cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1157 memmove((char *)cp + ipt->ipt_ptr - 1, cp0,
1158 sizeof(n_time));
1159 ipt->ipt_ptr += sizeof(n_time);
1160 }
1161 }
1162 if (forward) {
1163 struct ifnet *rcvif;
1164 struct psref _psref;
1165
1166 if (ip_forwsrcrt == 0) {
1167 type = ICMP_UNREACH;
1168 code = ICMP_UNREACH_SRCFAIL;
1169 goto bad;
1170 }
1171
1172 rcvif = m_get_rcvif_psref(m, &_psref);
1173 if (__predict_false(rcvif == NULL)) {
1174 type = ICMP_UNREACH;
1175 code = ICMP_UNREACH_HOST;
1176 goto bad;
1177 }
1178 ip_forward(m, 1, rcvif);
1179 m_put_rcvif_psref(rcvif, &_psref);
1180 return true;
1181 }
1182 return false;
1183 bad:
1184 icmp_error(m, type, code, 0, 0);
1185 IP_STATINC(IP_STAT_BADOPTIONS);
1186 return true;
1187 }
1188
1189 /*
1190 * ip_rtaddr: given address of next destination (final or next hop),
1191 * return internet address info of interface to be used to get there.
1192 */
1193 static struct in_ifaddr *
1194 ip_rtaddr(struct in_addr dst, struct psref *psref)
1195 {
1196 struct rtentry *rt;
1197 union {
1198 struct sockaddr dst;
1199 struct sockaddr_in dst4;
1200 } u;
1201 struct route *ro;
1202
1203 sockaddr_in_init(&u.dst4, &dst, 0);
1204
1205 ro = percpu_getref(ipforward_rt_percpu);
1206 rt = rtcache_lookup(ro, &u.dst);
1207 if (rt == NULL) {
1208 percpu_putref(ipforward_rt_percpu);
1209 return NULL;
1210 }
1211
1212 ia4_acquire(ifatoia(rt->rt_ifa), psref);
1213 rtcache_unref(rt, ro);
1214 percpu_putref(ipforward_rt_percpu);
1215
1216 return ifatoia(rt->rt_ifa);
1217 }
1218
1219 /*
1220 * save_rte: save incoming source route for use in replies, to be picked
1221 * up later by ip_srcroute if the receiver is interested.
1222 */
1223 static void
1224 save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1225 {
1226 struct ip_srcrt *isr;
1227 struct m_tag *mtag;
1228 unsigned olen;
1229
1230 olen = option[IPOPT_OLEN];
1231 if (olen > sizeof(isr->isr_hdr) + sizeof(isr->isr_routes))
1232 return;
1233
1234 mtag = m_tag_get(PACKET_TAG_SRCROUTE, sizeof(*isr), M_NOWAIT);
1235 if (mtag == NULL)
1236 return;
1237 isr = (struct ip_srcrt *)(mtag + 1);
1238
1239 memcpy(isr->isr_hdr, option, olen);
1240 isr->isr_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1241 isr->isr_dst = dst;
1242 m_tag_prepend(m, mtag);
1243 }
1244
1245 /*
1246 * Retrieve incoming source route for use in replies,
1247 * in the same form used by setsockopt.
1248 * The first hop is placed before the options, will be removed later.
1249 */
1250 struct mbuf *
1251 ip_srcroute(struct mbuf *m0)
1252 {
1253 struct in_addr *p, *q;
1254 struct mbuf *m;
1255 struct ip_srcrt *isr;
1256 struct m_tag *mtag;
1257
1258 mtag = m_tag_find(m0, PACKET_TAG_SRCROUTE, NULL);
1259 if (mtag == NULL)
1260 return NULL;
1261 isr = (struct ip_srcrt *)(mtag + 1);
1262
1263 if (isr->isr_nhops == 0)
1264 return NULL;
1265
1266 m = m_get(M_DONTWAIT, MT_SOOPTS);
1267 if (m == NULL)
1268 return NULL;
1269
1270 MCLAIM(m, &inetdomain.dom_mowner);
1271 #define OPTSIZ (sizeof(isr->isr_nop) + sizeof(isr->isr_hdr))
1272
1273 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + header) */
1274 m->m_len = (isr->isr_nhops + 1) * sizeof(struct in_addr) + OPTSIZ;
1275
1276 /*
1277 * First save first hop for return route
1278 */
1279 p = &(isr->isr_routes[isr->isr_nhops - 1]);
1280 *(mtod(m, struct in_addr *)) = *p--;
1281
1282 /*
1283 * Copy option fields and padding (nop) to mbuf.
1284 */
1285 isr->isr_nop = IPOPT_NOP;
1286 isr->isr_hdr[IPOPT_OFFSET] = IPOPT_MINOFF;
1287 memmove(mtod(m, char *) + sizeof(struct in_addr), &isr->isr_nop,
1288 OPTSIZ);
1289 q = (struct in_addr *)(mtod(m, char *) +
1290 sizeof(struct in_addr) + OPTSIZ);
1291 #undef OPTSIZ
1292 /*
1293 * Record return path as an IP source route,
1294 * reversing the path (pointers are now aligned).
1295 */
1296 while (p >= isr->isr_routes) {
1297 *q++ = *p--;
1298 }
1299 /*
1300 * Last hop goes to final destination.
1301 */
1302 *q = isr->isr_dst;
1303 m_tag_delete(m0, mtag);
1304 return m;
1305 }
1306
1307 const int inetctlerrmap[PRC_NCMDS] = {
1308 [PRC_MSGSIZE] = EMSGSIZE,
1309 [PRC_HOSTDEAD] = EHOSTDOWN,
1310 [PRC_HOSTUNREACH] = EHOSTUNREACH,
1311 [PRC_UNREACH_NET] = EHOSTUNREACH,
1312 [PRC_UNREACH_HOST] = EHOSTUNREACH,
1313 [PRC_UNREACH_PROTOCOL] = ECONNREFUSED,
1314 [PRC_UNREACH_PORT] = ECONNREFUSED,
1315 [PRC_UNREACH_SRCFAIL] = EHOSTUNREACH,
1316 [PRC_PARAMPROB] = ENOPROTOOPT,
1317 };
1318
1319 void
1320 ip_fasttimo(void)
1321 {
1322 if (ip_drainwanted) {
1323 ip_drain();
1324 ip_drainwanted = 0;
1325 }
1326 }
1327
1328 void
1329 ip_drainstub(void)
1330 {
1331 ip_drainwanted = 1;
1332 }
1333
1334 /*
1335 * Forward a packet. If some error occurs return the sender
1336 * an icmp packet. Note we can't always generate a meaningful
1337 * icmp message because icmp doesn't have a large enough repertoire
1338 * of codes and types.
1339 *
1340 * If not forwarding, just drop the packet. This could be confusing
1341 * if ipforwarding was zero but some routing protocol was advancing
1342 * us as a gateway to somewhere. However, we must let the routing
1343 * protocol deal with that.
1344 *
1345 * The srcrt parameter indicates whether the packet is being forwarded
1346 * via a source route.
1347 */
1348 static void
1349 ip_forward(struct mbuf *m, int srcrt, struct ifnet *rcvif)
1350 {
1351 struct ip *ip = mtod(m, struct ip *);
1352 struct rtentry *rt;
1353 int error, type = 0, code = 0, destmtu = 0;
1354 struct mbuf *mcopy;
1355 n_long dest;
1356 union {
1357 struct sockaddr dst;
1358 struct sockaddr_in dst4;
1359 } u;
1360 uint64_t *ips;
1361 struct route *ro;
1362
1363 KASSERTMSG(cpu_softintr_p(), "ip_forward: not in the software "
1364 "interrupt handler; synchronization assumptions violated");
1365
1366 /*
1367 * We are now in the output path.
1368 */
1369 MCLAIM(m, &ip_tx_mowner);
1370
1371 /*
1372 * Clear any in-bound checksum flags for this packet.
1373 */
1374 m->m_pkthdr.csum_flags = 0;
1375
1376 dest = 0;
1377 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1378 IP_STATINC(IP_STAT_CANTFORWARD);
1379 m_freem(m);
1380 return;
1381 }
1382
1383 if (ip->ip_ttl <= IPTTLDEC) {
1384 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1385 return;
1386 }
1387
1388 sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
1389
1390 ro = percpu_getref(ipforward_rt_percpu);
1391 rt = rtcache_lookup(ro, &u.dst);
1392 if (rt == NULL) {
1393 percpu_putref(ipforward_rt_percpu);
1394 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1395 return;
1396 }
1397
1398 /*
1399 * Save at most 68 bytes of the packet in case
1400 * we need to generate an ICMP message to the src.
1401 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1402 */
1403 mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1404 if (mcopy)
1405 mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1406
1407 ip->ip_ttl -= IPTTLDEC;
1408
1409 /*
1410 * If forwarding packet using same interface that it came in on,
1411 * perhaps should send a redirect to sender to shortcut a hop.
1412 * Only send redirect if source is sending directly to us,
1413 * and if packet was not source routed (or has any options).
1414 * Also, don't send redirect if forwarding using a default route
1415 * or a route modified by a redirect.
1416 */
1417 if (rt->rt_ifp == rcvif &&
1418 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1419 !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) &&
1420 ipsendredirects && !srcrt) {
1421 if (rt->rt_ifa &&
1422 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1423 ifatoia(rt->rt_ifa)->ia_subnet) {
1424 if (rt->rt_flags & RTF_GATEWAY)
1425 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1426 else
1427 dest = ip->ip_dst.s_addr;
1428 /*
1429 * Router requirements says to only send host
1430 * redirects.
1431 */
1432 type = ICMP_REDIRECT;
1433 code = ICMP_REDIRECT_HOST;
1434 }
1435 }
1436 rtcache_unref(rt, ro);
1437
1438 error = ip_output(m, NULL, ro,
1439 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1440 NULL, NULL);
1441
1442 if (error) {
1443 IP_STATINC(IP_STAT_CANTFORWARD);
1444 goto error;
1445 }
1446
1447 ips = IP_STAT_GETREF();
1448 ips[IP_STAT_FORWARD]++;
1449
1450 if (type) {
1451 ips[IP_STAT_REDIRECTSENT]++;
1452 IP_STAT_PUTREF();
1453 goto redirect;
1454 }
1455
1456 IP_STAT_PUTREF();
1457 if (mcopy) {
1458 #ifdef GATEWAY
1459 if (mcopy->m_flags & M_CANFASTFWD)
1460 ipflow_create(ro, mcopy);
1461 #endif
1462 m_freem(mcopy);
1463 }
1464
1465 percpu_putref(ipforward_rt_percpu);
1466 return;
1467
1468 redirect:
1469 error:
1470 if (mcopy == NULL) {
1471 percpu_putref(ipforward_rt_percpu);
1472 return;
1473 }
1474
1475 switch (error) {
1476
1477 case 0: /* forwarded, but need redirect */
1478 /* type, code set above */
1479 break;
1480
1481 case ENETUNREACH: /* shouldn't happen, checked above */
1482 case EHOSTUNREACH:
1483 case ENETDOWN:
1484 case EHOSTDOWN:
1485 default:
1486 type = ICMP_UNREACH;
1487 code = ICMP_UNREACH_HOST;
1488 break;
1489
1490 case EMSGSIZE:
1491 type = ICMP_UNREACH;
1492 code = ICMP_UNREACH_NEEDFRAG;
1493
1494 if ((rt = rtcache_validate(ro)) != NULL) {
1495 destmtu = rt->rt_ifp->if_mtu;
1496 rtcache_unref(rt, ro);
1497 }
1498 #ifdef IPSEC
1499 if (ipsec_used)
1500 (void)ipsec4_forward(mcopy, &destmtu);
1501 #endif
1502 IP_STATINC(IP_STAT_CANTFRAG);
1503 break;
1504
1505 case ENOBUFS:
1506 /*
1507 * Do not generate ICMP_SOURCEQUENCH as required in RFC 1812,
1508 * Requirements for IP Version 4 Routers. Source quench can
1509 * big problem under DoS attacks or if the underlying
1510 * interface is rate-limited.
1511 */
1512 if (mcopy)
1513 m_freem(mcopy);
1514 percpu_putref(ipforward_rt_percpu);
1515 return;
1516 }
1517 icmp_error(mcopy, type, code, dest, destmtu);
1518 percpu_putref(ipforward_rt_percpu);
1519 }
1520
1521 void
1522 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1523 struct mbuf *m)
1524 {
1525 struct socket *so = inp->inp_socket;
1526 int inpflags = inp->inp_flags;
1527
1528 if (SOOPT_TIMESTAMP(so->so_options))
1529 mp = sbsavetimestamp(so->so_options, m, mp);
1530
1531 if (inpflags & INP_RECVDSTADDR) {
1532 *mp = sbcreatecontrol(&ip->ip_dst,
1533 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1534 if (*mp)
1535 mp = &(*mp)->m_next;
1536 }
1537
1538 if (inpflags & INP_RECVTTL) {
1539 *mp = sbcreatecontrol(&ip->ip_ttl,
1540 sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP);
1541 if (*mp)
1542 mp = &(*mp)->m_next;
1543 }
1544
1545 struct psref psref;
1546 ifnet_t *ifp = m_get_rcvif_psref(m, &psref);
1547 if (__predict_false(ifp == NULL)) {
1548 #ifdef DIAGNOSTIC
1549 printf("%s: missing receive interface\n", __func__);
1550 #endif
1551 return; /* XXX should report error? */
1552 }
1553
1554 if (inpflags & INP_RECVPKTINFO) {
1555 struct in_pktinfo ipi;
1556 ipi.ipi_addr = ip->ip_dst;
1557 ipi.ipi_ifindex = ifp->if_index;
1558 *mp = sbcreatecontrol(&ipi,
1559 sizeof(ipi), IP_PKTINFO, IPPROTO_IP);
1560 if (*mp)
1561 mp = &(*mp)->m_next;
1562 }
1563 if (inpflags & INP_RECVIF) {
1564 struct sockaddr_dl sdl;
1565
1566 sockaddr_dl_init(&sdl, sizeof(sdl), ifp->if_index, 0, NULL, 0,
1567 NULL, 0);
1568 *mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP);
1569 if (*mp)
1570 mp = &(*mp)->m_next;
1571 }
1572 m_put_rcvif_psref(ifp, &psref);
1573 }
1574
1575 /*
1576 * sysctl helper routine for net.inet.ip.forwsrcrt.
1577 */
1578 static int
1579 sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
1580 {
1581 int error, tmp;
1582 struct sysctlnode node;
1583
1584 node = *rnode;
1585 tmp = ip_forwsrcrt;
1586 node.sysctl_data = &tmp;
1587 error = sysctl_lookup(SYSCTLFN_CALL(&node));
1588 if (error || newp == NULL)
1589 return (error);
1590
1591 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
1592 0, NULL, NULL, NULL);
1593 if (error)
1594 return (error);
1595
1596 ip_forwsrcrt = tmp;
1597
1598 return (0);
1599 }
1600
1601 /*
1602 * sysctl helper routine for net.inet.ip.mtudisctimeout. checks the
1603 * range of the new value and tweaks timers if it changes.
1604 */
1605 static int
1606 sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1607 {
1608 int error, tmp;
1609 struct sysctlnode node;
1610
1611 icmp_mtudisc_lock();
1612
1613 node = *rnode;
1614 tmp = ip_mtudisc_timeout;
1615 node.sysctl_data = &tmp;
1616 error = sysctl_lookup(SYSCTLFN_CALL(&node));
1617 if (error || newp == NULL)
1618 goto out;
1619 if (tmp < 0) {
1620 error = EINVAL;
1621 goto out;
1622 }
1623
1624 ip_mtudisc_timeout = tmp;
1625 rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
1626 error = 0;
1627 out:
1628 icmp_mtudisc_unlock();
1629 return error;
1630 }
1631
1632 static int
1633 sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)
1634 {
1635
1636 return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS));
1637 }
1638
1639 static void
1640 sysctl_net_inet_ip_setup(struct sysctllog **clog)
1641 {
1642 sysctl_createv(clog, 0, NULL, NULL,
1643 CTLFLAG_PERMANENT,
1644 CTLTYPE_NODE, "inet",
1645 SYSCTL_DESCR("PF_INET related settings"),
1646 NULL, 0, NULL, 0,
1647 CTL_NET, PF_INET, CTL_EOL);
1648 sysctl_createv(clog, 0, NULL, NULL,
1649 CTLFLAG_PERMANENT,
1650 CTLTYPE_NODE, "ip",
1651 SYSCTL_DESCR("IPv4 related settings"),
1652 NULL, 0, NULL, 0,
1653 CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1654
1655 sysctl_createv(clog, 0, NULL, NULL,
1656 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1657 CTLTYPE_INT, "forwarding",
1658 SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1659 NULL, 0, &ipforwarding, 0,
1660 CTL_NET, PF_INET, IPPROTO_IP,
1661 IPCTL_FORWARDING, CTL_EOL);
1662 sysctl_createv(clog, 0, NULL, NULL,
1663 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1664 CTLTYPE_INT, "redirect",
1665 SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1666 NULL, 0, &ipsendredirects, 0,
1667 CTL_NET, PF_INET, IPPROTO_IP,
1668 IPCTL_SENDREDIRECTS, CTL_EOL);
1669 sysctl_createv(clog, 0, NULL, NULL,
1670 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1671 CTLTYPE_INT, "ttl",
1672 SYSCTL_DESCR("Default TTL for an INET datagram"),
1673 NULL, 0, &ip_defttl, 0,
1674 CTL_NET, PF_INET, IPPROTO_IP,
1675 IPCTL_DEFTTL, CTL_EOL);
1676 #ifdef IPCTL_DEFMTU
1677 sysctl_createv(clog, 0, NULL, NULL,
1678 CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */,
1679 CTLTYPE_INT, "mtu",
1680 SYSCTL_DESCR("Default MTA for an INET route"),
1681 NULL, 0, &ip_mtu, 0,
1682 CTL_NET, PF_INET, IPPROTO_IP,
1683 IPCTL_DEFMTU, CTL_EOL);
1684 #endif /* IPCTL_DEFMTU */
1685 sysctl_createv(clog, 0, NULL, NULL,
1686 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1687 CTLTYPE_INT, "forwsrcrt",
1688 SYSCTL_DESCR("Enable forwarding of source-routed "
1689 "datagrams"),
1690 sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1691 CTL_NET, PF_INET, IPPROTO_IP,
1692 IPCTL_FORWSRCRT, CTL_EOL);
1693 sysctl_createv(clog, 0, NULL, NULL,
1694 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1695 CTLTYPE_INT, "directed-broadcast",
1696 SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1697 NULL, 0, &ip_directedbcast, 0,
1698 CTL_NET, PF_INET, IPPROTO_IP,
1699 IPCTL_DIRECTEDBCAST, CTL_EOL);
1700 sysctl_createv(clog, 0, NULL, NULL,
1701 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1702 CTLTYPE_INT, "allowsrcrt",
1703 SYSCTL_DESCR("Accept source-routed datagrams"),
1704 NULL, 0, &ip_allowsrcrt, 0,
1705 CTL_NET, PF_INET, IPPROTO_IP,
1706 IPCTL_ALLOWSRCRT, CTL_EOL);
1707
1708 sysctl_createv(clog, 0, NULL, NULL,
1709 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1710 CTLTYPE_INT, "mtudisc",
1711 SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1712 NULL, 0, &ip_mtudisc, 0,
1713 CTL_NET, PF_INET, IPPROTO_IP,
1714 IPCTL_MTUDISC, CTL_EOL);
1715 sysctl_createv(clog, 0, NULL, NULL,
1716 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1717 CTLTYPE_INT, "anonportmin",
1718 SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1719 sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
1720 CTL_NET, PF_INET, IPPROTO_IP,
1721 IPCTL_ANONPORTMIN, CTL_EOL);
1722 sysctl_createv(clog, 0, NULL, NULL,
1723 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1724 CTLTYPE_INT, "anonportmax",
1725 SYSCTL_DESCR("Highest ephemeral port number to assign"),
1726 sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
1727 CTL_NET, PF_INET, IPPROTO_IP,
1728 IPCTL_ANONPORTMAX, CTL_EOL);
1729 sysctl_createv(clog, 0, NULL, NULL,
1730 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1731 CTLTYPE_INT, "mtudisctimeout",
1732 SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1733 sysctl_net_inet_ip_pmtudto, 0, (void *)&ip_mtudisc_timeout, 0,
1734 CTL_NET, PF_INET, IPPROTO_IP,
1735 IPCTL_MTUDISCTIMEOUT, CTL_EOL);
1736 #ifndef IPNOPRIVPORTS
1737 sysctl_createv(clog, 0, NULL, NULL,
1738 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1739 CTLTYPE_INT, "lowportmin",
1740 SYSCTL_DESCR("Lowest privileged ephemeral port number "
1741 "to assign"),
1742 sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
1743 CTL_NET, PF_INET, IPPROTO_IP,
1744 IPCTL_LOWPORTMIN, CTL_EOL);
1745 sysctl_createv(clog, 0, NULL, NULL,
1746 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1747 CTLTYPE_INT, "lowportmax",
1748 SYSCTL_DESCR("Highest privileged ephemeral port number "
1749 "to assign"),
1750 sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
1751 CTL_NET, PF_INET, IPPROTO_IP,
1752 IPCTL_LOWPORTMAX, CTL_EOL);
1753 #endif /* IPNOPRIVPORTS */
1754 #if NGRE > 0
1755 sysctl_createv(clog, 0, NULL, NULL,
1756 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1757 CTLTYPE_INT, "grettl",
1758 SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1759 NULL, 0, &ip_gre_ttl, 0,
1760 CTL_NET, PF_INET, IPPROTO_IP,
1761 IPCTL_GRE_TTL, CTL_EOL);
1762 #endif /* NGRE */
1763 sysctl_createv(clog, 0, NULL, NULL,
1764 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1765 CTLTYPE_INT, "checkinterface",
1766 SYSCTL_DESCR("Enable receive side of Strong ES model "
1767 "from RFC1122"),
1768 NULL, 0, &ip_checkinterface, 0,
1769 CTL_NET, PF_INET, IPPROTO_IP,
1770 IPCTL_CHECKINTERFACE, CTL_EOL);
1771 sysctl_createv(clog, 0, NULL, NULL,
1772 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1773 CTLTYPE_INT, "random_id",
1774 SYSCTL_DESCR("Assign random ip_id values"),
1775 NULL, 0, &ip_do_randomid, 0,
1776 CTL_NET, PF_INET, IPPROTO_IP,
1777 IPCTL_RANDOMID, CTL_EOL);
1778 sysctl_createv(clog, 0, NULL, NULL,
1779 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1780 CTLTYPE_INT, "do_loopback_cksum",
1781 SYSCTL_DESCR("Perform IP checksum on loopback"),
1782 NULL, 0, &ip_do_loopback_cksum, 0,
1783 CTL_NET, PF_INET, IPPROTO_IP,
1784 IPCTL_LOOPBACKCKSUM, CTL_EOL);
1785 sysctl_createv(clog, 0, NULL, NULL,
1786 CTLFLAG_PERMANENT,
1787 CTLTYPE_STRUCT, "stats",
1788 SYSCTL_DESCR("IP statistics"),
1789 sysctl_net_inet_ip_stats, 0, NULL, 0,
1790 CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
1791 CTL_EOL);
1792 #if NARP
1793 sysctl_createv(clog, 0, NULL, NULL,
1794 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1795 CTLTYPE_INT, "dad_count",
1796 SYSCTL_DESCR("Number of Duplicate Address Detection "
1797 "probes to send"),
1798 NULL, 0, &ip_dad_count, 0,
1799 CTL_NET, PF_INET, IPPROTO_IP,
1800 IPCTL_DAD_COUNT, CTL_EOL);
1801 #endif
1802
1803 /* anonportalgo RFC6056 subtree */
1804 const struct sysctlnode *portalgo_node;
1805 sysctl_createv(clog, 0, NULL, &portalgo_node,
1806 CTLFLAG_PERMANENT,
1807 CTLTYPE_NODE, "anonportalgo",
1808 SYSCTL_DESCR("Anonymous Port Algorithm Selection (RFC 6056)"),
1809 NULL, 0, NULL, 0,
1810 CTL_NET, PF_INET, IPPROTO_IP, CTL_CREATE, CTL_EOL);
1811 sysctl_createv(clog, 0, &portalgo_node, NULL,
1812 CTLFLAG_PERMANENT,
1813 CTLTYPE_STRING, "available",
1814 SYSCTL_DESCR("available algorithms"),
1815 sysctl_portalgo_available, 0, NULL, PORTALGO_MAXLEN,
1816 CTL_CREATE, CTL_EOL);
1817 sysctl_createv(clog, 0, &portalgo_node, NULL,
1818 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1819 CTLTYPE_STRING, "selected",
1820 SYSCTL_DESCR("selected algorithm"),
1821 sysctl_portalgo_selected4, 0, NULL, PORTALGO_MAXLEN,
1822 CTL_CREATE, CTL_EOL);
1823 sysctl_createv(clog, 0, &portalgo_node, NULL,
1824 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1825 CTLTYPE_STRUCT, "reserve",
1826 SYSCTL_DESCR("bitmap of reserved ports"),
1827 sysctl_portalgo_reserve4, 0, NULL, 0,
1828 CTL_CREATE, CTL_EOL);
1829 }
1830
1831 void
1832 ip_statinc(u_int stat)
1833 {
1834
1835 KASSERT(stat < IP_NSTATS);
1836 IP_STATINC(stat);
1837 }
1838