ip_input.c revision 1.168 1 /* $NetBSD: ip_input.c,v 1.168 2003/06/30 01:21:11 itojun 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 * 3. All advertising materials mentioning features or use of this software
49 * must display the following acknowledgement:
50 * This product includes software developed by the NetBSD
51 * Foundation, Inc. and its contributors.
52 * 4. Neither the name of The NetBSD Foundation nor the names of its
53 * contributors may be used to endorse or promote products derived
54 * from this software without specific prior written permission.
55 *
56 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
57 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
58 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
59 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
60 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
61 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
62 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
63 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
64 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
65 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
66 * POSSIBILITY OF SUCH DAMAGE.
67 */
68
69 /*
70 * Copyright (c) 1982, 1986, 1988, 1993
71 * The Regents of the University of California. All rights reserved.
72 *
73 * Redistribution and use in source and binary forms, with or without
74 * modification, are permitted provided that the following conditions
75 * are met:
76 * 1. Redistributions of source code must retain the above copyright
77 * notice, this list of conditions and the following disclaimer.
78 * 2. Redistributions in binary form must reproduce the above copyright
79 * notice, this list of conditions and the following disclaimer in the
80 * documentation and/or other materials provided with the distribution.
81 * 3. All advertising materials mentioning features or use of this software
82 * must display the following acknowledgement:
83 * This product includes software developed by the University of
84 * California, Berkeley and its contributors.
85 * 4. Neither the name of the University nor the names of its contributors
86 * may be used to endorse or promote products derived from this software
87 * without specific prior written permission.
88 *
89 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
90 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
91 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
92 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
93 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
94 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
95 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
96 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
97 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
98 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
99 * SUCH DAMAGE.
100 *
101 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
102 */
103
104 #include <sys/cdefs.h>
105 __KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.168 2003/06/30 01:21:11 itojun Exp $");
106
107 #include "opt_gateway.h"
108 #include "opt_pfil_hooks.h"
109 #include "opt_ipsec.h"
110 #include "opt_mrouting.h"
111 #include "opt_mbuftrace.h"
112 #include "opt_inet_csum.h"
113
114 #include <sys/param.h>
115 #include <sys/systm.h>
116 #include <sys/malloc.h>
117 #include <sys/mbuf.h>
118 #include <sys/domain.h>
119 #include <sys/protosw.h>
120 #include <sys/socket.h>
121 #include <sys/socketvar.h>
122 #include <sys/errno.h>
123 #include <sys/time.h>
124 #include <sys/kernel.h>
125 #include <sys/pool.h>
126 #include <sys/sysctl.h>
127
128 #include <net/if.h>
129 #include <net/if_dl.h>
130 #include <net/route.h>
131 #include <net/pfil.h>
132
133 #include <netinet/in.h>
134 #include <netinet/in_systm.h>
135 #include <netinet/ip.h>
136 #include <netinet/in_pcb.h>
137 #include <netinet/in_var.h>
138 #include <netinet/ip_var.h>
139 #include <netinet/ip_icmp.h>
140 /* just for gif_ttl */
141 #include <netinet/in_gif.h>
142 #include "gif.h"
143 #include <net/if_gre.h>
144 #include "gre.h"
145
146 #ifdef MROUTING
147 #include <netinet/ip_mroute.h>
148 #endif
149
150 #ifdef IPSEC
151 #include <netinet6/ipsec.h>
152 #include <netkey/key.h>
153 #endif
154
155 #ifndef IPFORWARDING
156 #ifdef GATEWAY
157 #define IPFORWARDING 1 /* forward IP packets not for us */
158 #else /* GATEWAY */
159 #define IPFORWARDING 0 /* don't forward IP packets not for us */
160 #endif /* GATEWAY */
161 #endif /* IPFORWARDING */
162 #ifndef IPSENDREDIRECTS
163 #define IPSENDREDIRECTS 1
164 #endif
165 #ifndef IPFORWSRCRT
166 #define IPFORWSRCRT 1 /* forward source-routed packets */
167 #endif
168 #ifndef IPALLOWSRCRT
169 #define IPALLOWSRCRT 1 /* allow source-routed packets */
170 #endif
171 #ifndef IPMTUDISC
172 #define IPMTUDISC 1
173 #endif
174 #ifndef IPMTUDISCTIMEOUT
175 #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
176 #endif
177
178 /*
179 * Note: DIRECTED_BROADCAST is handled this way so that previous
180 * configuration using this option will Just Work.
181 */
182 #ifndef IPDIRECTEDBCAST
183 #ifdef DIRECTED_BROADCAST
184 #define IPDIRECTEDBCAST 1
185 #else
186 #define IPDIRECTEDBCAST 0
187 #endif /* DIRECTED_BROADCAST */
188 #endif /* IPDIRECTEDBCAST */
189 int ipforwarding = IPFORWARDING;
190 int ipsendredirects = IPSENDREDIRECTS;
191 int ip_defttl = IPDEFTTL;
192 int ip_forwsrcrt = IPFORWSRCRT;
193 int ip_directedbcast = IPDIRECTEDBCAST;
194 int ip_allowsrcrt = IPALLOWSRCRT;
195 int ip_mtudisc = IPMTUDISC;
196 int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
197 #ifdef DIAGNOSTIC
198 int ipprintfs = 0;
199 #endif
200 /*
201 * XXX - Setting ip_checkinterface mostly implements the receive side of
202 * the Strong ES model described in RFC 1122, but since the routing table
203 * and transmit implementation do not implement the Strong ES model,
204 * setting this to 1 results in an odd hybrid.
205 *
206 * XXX - ip_checkinterface currently must be disabled if you use ipnat
207 * to translate the destination address to another local interface.
208 *
209 * XXX - ip_checkinterface must be disabled if you add IP aliases
210 * to the loopback interface instead of the interface where the
211 * packets for those addresses are received.
212 */
213 int ip_checkinterface = 0;
214
215
216 struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
217
218 extern struct domain inetdomain;
219 int ipqmaxlen = IFQ_MAXLEN;
220 u_long in_ifaddrhash; /* size of hash table - 1 */
221 int in_ifaddrentries; /* total number of addrs */
222 struct in_ifaddrhead in_ifaddr;
223 struct in_ifaddrhashhead *in_ifaddrhashtbl;
224 u_long in_multihash; /* size of hash table - 1 */
225 int in_multientries; /* total number of addrs */
226 struct in_multihead in_multi;
227 struct in_multihashhead *in_multihashtbl;
228 struct ifqueue ipintrq;
229 struct ipstat ipstat;
230 u_int16_t ip_id;
231
232 #ifdef PFIL_HOOKS
233 struct pfil_head inet_pfil_hook;
234 #endif
235
236 struct ipqhead ipq;
237 int ipq_locked;
238 int ip_nfragpackets = 0;
239 int ip_maxfragpackets = 200;
240
241 static __inline int ipq_lock_try __P((void));
242 static __inline void ipq_unlock __P((void));
243
244 static __inline int
245 ipq_lock_try()
246 {
247 int s;
248
249 /*
250 * Use splvm() -- we're blocking things that would cause
251 * mbuf allocation.
252 */
253 s = splvm();
254 if (ipq_locked) {
255 splx(s);
256 return (0);
257 }
258 ipq_locked = 1;
259 splx(s);
260 return (1);
261 }
262
263 static __inline void
264 ipq_unlock()
265 {
266 int s;
267
268 s = splvm();
269 ipq_locked = 0;
270 splx(s);
271 }
272
273 #ifdef DIAGNOSTIC
274 #define IPQ_LOCK() \
275 do { \
276 if (ipq_lock_try() == 0) { \
277 printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
278 panic("ipq_lock"); \
279 } \
280 } while (/*CONSTCOND*/ 0)
281 #define IPQ_LOCK_CHECK() \
282 do { \
283 if (ipq_locked == 0) { \
284 printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
285 panic("ipq lock check"); \
286 } \
287 } while (/*CONSTCOND*/ 0)
288 #else
289 #define IPQ_LOCK() (void) ipq_lock_try()
290 #define IPQ_LOCK_CHECK() /* nothing */
291 #endif
292
293 #define IPQ_UNLOCK() ipq_unlock()
294
295 struct pool inmulti_pool;
296 struct pool ipqent_pool;
297
298 #ifdef INET_CSUM_COUNTERS
299 #include <sys/device.h>
300
301 struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
302 NULL, "inet", "hwcsum bad");
303 struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
304 NULL, "inet", "hwcsum ok");
305 struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
306 NULL, "inet", "swcsum");
307
308 #define INET_CSUM_COUNTER_INCR(ev) (ev)->ev_count++
309
310 #else
311
312 #define INET_CSUM_COUNTER_INCR(ev) /* nothing */
313
314 #endif /* INET_CSUM_COUNTERS */
315
316 /*
317 * We need to save the IP options in case a protocol wants to respond
318 * to an incoming packet over the same route if the packet got here
319 * using IP source routing. This allows connection establishment and
320 * maintenance when the remote end is on a network that is not known
321 * to us.
322 */
323 int ip_nhops = 0;
324 static struct ip_srcrt {
325 struct in_addr dst; /* final destination */
326 char nop; /* one NOP to align */
327 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
328 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
329 } ip_srcrt;
330
331 static void save_rte __P((u_char *, struct in_addr));
332
333 #ifdef MBUFTRACE
334 struct mowner ip_rx_mowner = { "internet", "rx" };
335 struct mowner ip_tx_mowner = { "internet", "tx" };
336 #endif
337
338 /*
339 * IP initialization: fill in IP protocol switch table.
340 * All protocols not implemented in kernel go to raw IP protocol handler.
341 */
342 void
343 ip_init()
344 {
345 struct protosw *pr;
346 int i;
347
348 pool_init(&inmulti_pool, sizeof(struct in_multi), 0, 0, 0, "inmltpl",
349 NULL);
350 pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
351 NULL);
352
353 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
354 if (pr == 0)
355 panic("ip_init");
356 for (i = 0; i < IPPROTO_MAX; i++)
357 ip_protox[i] = pr - inetsw;
358 for (pr = inetdomain.dom_protosw;
359 pr < inetdomain.dom_protoswNPROTOSW; pr++)
360 if (pr->pr_domain->dom_family == PF_INET &&
361 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
362 ip_protox[pr->pr_protocol] = pr - inetsw;
363 LIST_INIT(&ipq);
364 ip_id = time.tv_sec & 0xffff;
365 ipintrq.ifq_maxlen = ipqmaxlen;
366 TAILQ_INIT(&in_ifaddr);
367 in_ifaddrhashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IFADDR,
368 M_WAITOK, &in_ifaddrhash);
369 in_multihashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IPMADDR,
370 M_WAITOK, &in_multihash);
371 ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
372 #ifdef GATEWAY
373 ipflow_init();
374 #endif
375
376 #ifdef PFIL_HOOKS
377 /* Register our Packet Filter hook. */
378 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
379 inet_pfil_hook.ph_af = AF_INET;
380 i = pfil_head_register(&inet_pfil_hook);
381 if (i != 0)
382 printf("ip_init: WARNING: unable to register pfil hook, "
383 "error %d\n", i);
384 #endif /* PFIL_HOOKS */
385
386 #ifdef INET_CSUM_COUNTERS
387 evcnt_attach_static(&ip_hwcsum_bad);
388 evcnt_attach_static(&ip_hwcsum_ok);
389 evcnt_attach_static(&ip_swcsum);
390 #endif /* INET_CSUM_COUNTERS */
391
392 #ifdef MBUFTRACE
393 MOWNER_ATTACH(&ip_tx_mowner);
394 MOWNER_ATTACH(&ip_rx_mowner);
395 #endif /* MBUFTRACE */
396 }
397
398 struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
399 struct route ipforward_rt;
400
401 /*
402 * IP software interrupt routine
403 */
404 void
405 ipintr()
406 {
407 int s;
408 struct mbuf *m;
409
410 while (1) {
411 s = splnet();
412 IF_DEQUEUE(&ipintrq, m);
413 splx(s);
414 if (m == 0)
415 return;
416 MCLAIM(m, &ip_rx_mowner);
417 ip_input(m);
418 }
419 }
420
421 /*
422 * Ip input routine. Checksum and byte swap header. If fragmented
423 * try to reassemble. Process options. Pass to next level.
424 */
425 void
426 ip_input(struct mbuf *m)
427 {
428 struct ip *ip = NULL;
429 struct ipq *fp;
430 struct in_ifaddr *ia;
431 struct ifaddr *ifa;
432 struct ipqent *ipqe;
433 int hlen = 0, mff, len;
434 int downmatch;
435 int checkif;
436
437 MCLAIM(m, &ip_rx_mowner);
438 #ifdef DIAGNOSTIC
439 if ((m->m_flags & M_PKTHDR) == 0)
440 panic("ipintr no HDR");
441 #endif
442 #ifdef IPSEC
443 /*
444 * should the inner packet be considered authentic?
445 * see comment in ah4_input().
446 */
447 if (m) {
448 m->m_flags &= ~M_AUTHIPHDR;
449 m->m_flags &= ~M_AUTHIPDGM;
450 }
451 #endif
452
453 /*
454 * If no IP addresses have been set yet but the interfaces
455 * are receiving, can't do anything with incoming packets yet.
456 */
457 if (TAILQ_FIRST(&in_ifaddr) == 0)
458 goto bad;
459 ipstat.ips_total++;
460 /*
461 * If the IP header is not aligned, slurp it up into a new
462 * mbuf with space for link headers, in the event we forward
463 * it. Otherwise, if it is aligned, make sure the entire
464 * base IP header is in the first mbuf of the chain.
465 */
466 if (IP_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) {
467 if ((m = m_copyup(m, sizeof(struct ip),
468 (max_linkhdr + 3) & ~3)) == NULL) {
469 /* XXXJRT new stat, please */
470 ipstat.ips_toosmall++;
471 return;
472 }
473 } else if (__predict_false(m->m_len < sizeof (struct ip))) {
474 if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
475 ipstat.ips_toosmall++;
476 return;
477 }
478 }
479 ip = mtod(m, struct ip *);
480 if (ip->ip_v != IPVERSION) {
481 ipstat.ips_badvers++;
482 goto bad;
483 }
484 hlen = ip->ip_hl << 2;
485 if (hlen < sizeof(struct ip)) { /* minimum header length */
486 ipstat.ips_badhlen++;
487 goto bad;
488 }
489 if (hlen > m->m_len) {
490 if ((m = m_pullup(m, hlen)) == 0) {
491 ipstat.ips_badhlen++;
492 return;
493 }
494 ip = mtod(m, struct ip *);
495 }
496
497 /*
498 * RFC1122: packets with a multicast source address are
499 * not allowed.
500 */
501 if (IN_MULTICAST(ip->ip_src.s_addr)) {
502 ipstat.ips_badaddr++;
503 goto bad;
504 }
505
506 /* 127/8 must not appear on wire - RFC1122 */
507 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
508 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
509 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
510 ipstat.ips_badaddr++;
511 goto bad;
512 }
513 }
514
515 switch (m->m_pkthdr.csum_flags &
516 ((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
517 M_CSUM_IPv4_BAD)) {
518 case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
519 INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
520 goto badcsum;
521
522 case M_CSUM_IPv4:
523 /* Checksum was okay. */
524 INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
525 break;
526
527 default:
528 /* Must compute it ourselves. */
529 INET_CSUM_COUNTER_INCR(&ip_swcsum);
530 if (in_cksum(m, hlen) != 0)
531 goto bad;
532 break;
533 }
534
535 /* Retrieve the packet length. */
536 len = ntohs(ip->ip_len);
537
538 /*
539 * Check for additional length bogosity
540 */
541 if (len < hlen) {
542 ipstat.ips_badlen++;
543 goto bad;
544 }
545
546 /*
547 * Check that the amount of data in the buffers
548 * is as at least much as the IP header would have us expect.
549 * Trim mbufs if longer than we expect.
550 * Drop packet if shorter than we expect.
551 */
552 if (m->m_pkthdr.len < len) {
553 ipstat.ips_tooshort++;
554 goto bad;
555 }
556 if (m->m_pkthdr.len > len) {
557 if (m->m_len == m->m_pkthdr.len) {
558 m->m_len = len;
559 m->m_pkthdr.len = len;
560 } else
561 m_adj(m, len - m->m_pkthdr.len);
562 }
563
564 #ifdef IPSEC
565 /* ipflow (IP fast forwarding) is not compatible with IPsec. */
566 m->m_flags &= ~M_CANFASTFWD;
567 #else
568 /*
569 * Assume that we can create a fast-forward IP flow entry
570 * based on this packet.
571 */
572 m->m_flags |= M_CANFASTFWD;
573 #endif
574
575 #ifdef PFIL_HOOKS
576 /*
577 * Run through list of hooks for input packets. If there are any
578 * filters which require that additional packets in the flow are
579 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
580 * Note that filters must _never_ set this flag, as another filter
581 * in the list may have previously cleared it.
582 */
583 /*
584 * let ipfilter look at packet on the wire,
585 * not the decapsulated packet.
586 */
587 #ifdef IPSEC
588 if (!ipsec_getnhist(m))
589 #else
590 if (1)
591 #endif
592 {
593 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
594 PFIL_IN) != 0)
595 return;
596 if (m == NULL)
597 return;
598 ip = mtod(m, struct ip *);
599 hlen = ip->ip_hl << 2;
600 }
601 #endif /* PFIL_HOOKS */
602
603 #ifdef ALTQ
604 /* XXX Temporary until ALTQ is changed to use a pfil hook */
605 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
606 /* packet dropped by traffic conditioner */
607 return;
608 }
609 #endif
610
611 /*
612 * Process options and, if not destined for us,
613 * ship it on. ip_dooptions returns 1 when an
614 * error was detected (causing an icmp message
615 * to be sent and the original packet to be freed).
616 */
617 ip_nhops = 0; /* for source routed packets */
618 if (hlen > sizeof (struct ip) && ip_dooptions(m))
619 return;
620
621 /*
622 * Enable a consistency check between the destination address
623 * and the arrival interface for a unicast packet (the RFC 1122
624 * strong ES model) if IP forwarding is disabled and the packet
625 * is not locally generated.
626 *
627 * XXX - Checking also should be disabled if the destination
628 * address is ipnat'ed to a different interface.
629 *
630 * XXX - Checking is incompatible with IP aliases added
631 * to the loopback interface instead of the interface where
632 * the packets are received.
633 *
634 * XXX - We need to add a per ifaddr flag for this so that
635 * we get finer grain control.
636 */
637 checkif = ip_checkinterface && (ipforwarding == 0) &&
638 (m->m_pkthdr.rcvif != NULL) &&
639 ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0);
640
641 /*
642 * Check our list of addresses, to see if the packet is for us.
643 *
644 * Traditional 4.4BSD did not consult IFF_UP at all.
645 * The behavior here is to treat addresses on !IFF_UP interface
646 * as not mine.
647 */
648 downmatch = 0;
649 LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
650 if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
651 if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif)
652 continue;
653 if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
654 break;
655 else
656 downmatch++;
657 }
658 }
659 if (ia != NULL)
660 goto ours;
661 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
662 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) {
663 if (ifa->ifa_addr->sa_family != AF_INET)
664 continue;
665 ia = ifatoia(ifa);
666 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
667 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
668 /*
669 * Look for all-0's host part (old broadcast addr),
670 * either for subnet or net.
671 */
672 ip->ip_dst.s_addr == ia->ia_subnet ||
673 ip->ip_dst.s_addr == ia->ia_net)
674 goto ours;
675 /*
676 * An interface with IP address zero accepts
677 * all packets that arrive on that interface.
678 */
679 if (in_nullhost(ia->ia_addr.sin_addr))
680 goto ours;
681 }
682 }
683 if (IN_MULTICAST(ip->ip_dst.s_addr)) {
684 struct in_multi *inm;
685 #ifdef MROUTING
686 extern struct socket *ip_mrouter;
687
688 if (M_READONLY(m)) {
689 if ((m = m_pullup(m, hlen)) == 0) {
690 ipstat.ips_toosmall++;
691 return;
692 }
693 ip = mtod(m, struct ip *);
694 }
695
696 if (ip_mrouter) {
697 /*
698 * If we are acting as a multicast router, all
699 * incoming multicast packets are passed to the
700 * kernel-level multicast forwarding function.
701 * The packet is returned (relatively) intact; if
702 * ip_mforward() returns a non-zero value, the packet
703 * must be discarded, else it may be accepted below.
704 *
705 * (The IP ident field is put in the same byte order
706 * as expected when ip_mforward() is called from
707 * ip_output().)
708 */
709 if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
710 ipstat.ips_cantforward++;
711 m_freem(m);
712 return;
713 }
714
715 /*
716 * The process-level routing demon needs to receive
717 * all multicast IGMP packets, whether or not this
718 * host belongs to their destination groups.
719 */
720 if (ip->ip_p == IPPROTO_IGMP)
721 goto ours;
722 ipstat.ips_forward++;
723 }
724 #endif
725 /*
726 * See if we belong to the destination multicast group on the
727 * arrival interface.
728 */
729 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
730 if (inm == NULL) {
731 ipstat.ips_cantforward++;
732 m_freem(m);
733 return;
734 }
735 goto ours;
736 }
737 if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
738 in_nullhost(ip->ip_dst))
739 goto ours;
740
741 /*
742 * Not for us; forward if possible and desirable.
743 */
744 if (ipforwarding == 0) {
745 ipstat.ips_cantforward++;
746 m_freem(m);
747 } else {
748 /*
749 * If ip_dst matched any of my address on !IFF_UP interface,
750 * and there's no IFF_UP interface that matches ip_dst,
751 * send icmp unreach. Forwarding it will result in in-kernel
752 * forwarding loop till TTL goes to 0.
753 */
754 if (downmatch) {
755 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
756 ipstat.ips_cantforward++;
757 return;
758 }
759 #ifdef IPSEC
760 if (ipsec4_in_reject(m, NULL)) {
761 ipsecstat.in_polvio++;
762 goto bad;
763 }
764 #endif
765
766 ip_forward(m, 0);
767 }
768 return;
769
770 ours:
771 /*
772 * If offset or IP_MF are set, must reassemble.
773 * Otherwise, nothing need be done.
774 * (We could look in the reassembly queue to see
775 * if the packet was previously fragmented,
776 * but it's not worth the time; just let them time out.)
777 */
778 if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
779 if (M_READONLY(m)) {
780 if ((m = m_pullup(m, hlen)) == NULL) {
781 ipstat.ips_toosmall++;
782 goto bad;
783 }
784 ip = mtod(m, struct ip *);
785 }
786
787 /*
788 * Look for queue of fragments
789 * of this datagram.
790 */
791 IPQ_LOCK();
792 LIST_FOREACH(fp, &ipq, ipq_q)
793 if (ip->ip_id == fp->ipq_id &&
794 in_hosteq(ip->ip_src, fp->ipq_src) &&
795 in_hosteq(ip->ip_dst, fp->ipq_dst) &&
796 ip->ip_p == fp->ipq_p)
797 goto found;
798 fp = 0;
799 found:
800
801 /*
802 * Adjust ip_len to not reflect header,
803 * set ipqe_mff if more fragments are expected,
804 * convert offset of this to bytes.
805 */
806 ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
807 mff = (ip->ip_off & htons(IP_MF)) != 0;
808 if (mff) {
809 /*
810 * Make sure that fragments have a data length
811 * that's a non-zero multiple of 8 bytes.
812 */
813 if (ntohs(ip->ip_len) == 0 ||
814 (ntohs(ip->ip_len) & 0x7) != 0) {
815 ipstat.ips_badfrags++;
816 IPQ_UNLOCK();
817 goto bad;
818 }
819 }
820 ip->ip_off = htons((ntohs(ip->ip_off) & IP_OFFMASK) << 3);
821
822 /*
823 * If datagram marked as having more fragments
824 * or if this is not the first fragment,
825 * attempt reassembly; if it succeeds, proceed.
826 */
827 if (mff || ip->ip_off != htons(0)) {
828 ipstat.ips_fragments++;
829 ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
830 if (ipqe == NULL) {
831 ipstat.ips_rcvmemdrop++;
832 IPQ_UNLOCK();
833 goto bad;
834 }
835 ipqe->ipqe_mff = mff;
836 ipqe->ipqe_m = m;
837 ipqe->ipqe_ip = ip;
838 m = ip_reass(ipqe, fp);
839 if (m == 0) {
840 IPQ_UNLOCK();
841 return;
842 }
843 ipstat.ips_reassembled++;
844 ip = mtod(m, struct ip *);
845 hlen = ip->ip_hl << 2;
846 ip->ip_len = htons(ntohs(ip->ip_len) + hlen);
847 } else
848 if (fp)
849 ip_freef(fp);
850 IPQ_UNLOCK();
851 }
852
853 #ifdef IPSEC
854 /*
855 * enforce IPsec policy checking if we are seeing last header.
856 * note that we do not visit this with protocols with pcb layer
857 * code - like udp/tcp/raw ip.
858 */
859 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
860 ipsec4_in_reject(m, NULL)) {
861 ipsecstat.in_polvio++;
862 goto bad;
863 }
864 #endif
865
866 /*
867 * Switch out to protocol's input routine.
868 */
869 #if IFA_STATS
870 if (ia && ip)
871 ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
872 #endif
873 ipstat.ips_delivered++;
874 {
875 int off = hlen, nh = ip->ip_p;
876
877 (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
878 return;
879 }
880 bad:
881 m_freem(m);
882 return;
883
884 badcsum:
885 ipstat.ips_badsum++;
886 m_freem(m);
887 }
888
889 /*
890 * Take incoming datagram fragment and try to
891 * reassemble it into whole datagram. If a chain for
892 * reassembly of this datagram already exists, then it
893 * is given as fp; otherwise have to make a chain.
894 */
895 struct mbuf *
896 ip_reass(ipqe, fp)
897 struct ipqent *ipqe;
898 struct ipq *fp;
899 {
900 struct mbuf *m = ipqe->ipqe_m;
901 struct ipqent *nq, *p, *q;
902 struct ip *ip;
903 struct mbuf *t;
904 int hlen = ipqe->ipqe_ip->ip_hl << 2;
905 int i, next;
906
907 IPQ_LOCK_CHECK();
908
909 /*
910 * Presence of header sizes in mbufs
911 * would confuse code below.
912 */
913 m->m_data += hlen;
914 m->m_len -= hlen;
915
916 /*
917 * If first fragment to arrive, create a reassembly queue.
918 */
919 if (fp == 0) {
920 /*
921 * Enforce upper bound on number of fragmented packets
922 * for which we attempt reassembly;
923 * If maxfrag is 0, never accept fragments.
924 * If maxfrag is -1, accept all fragments without limitation.
925 */
926 if (ip_maxfragpackets < 0)
927 ;
928 else if (ip_nfragpackets >= ip_maxfragpackets)
929 goto dropfrag;
930 ip_nfragpackets++;
931 MALLOC(fp, struct ipq *, sizeof (struct ipq),
932 M_FTABLE, M_NOWAIT);
933 if (fp == NULL)
934 goto dropfrag;
935 LIST_INSERT_HEAD(&ipq, fp, ipq_q);
936 fp->ipq_ttl = IPFRAGTTL;
937 fp->ipq_p = ipqe->ipqe_ip->ip_p;
938 fp->ipq_id = ipqe->ipqe_ip->ip_id;
939 TAILQ_INIT(&fp->ipq_fragq);
940 fp->ipq_src = ipqe->ipqe_ip->ip_src;
941 fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
942 p = NULL;
943 goto insert;
944 }
945
946 /*
947 * Find a segment which begins after this one does.
948 */
949 for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
950 p = q, q = TAILQ_NEXT(q, ipqe_q))
951 if (ntohs(q->ipqe_ip->ip_off) > ntohs(ipqe->ipqe_ip->ip_off))
952 break;
953
954 /*
955 * If there is a preceding segment, it may provide some of
956 * our data already. If so, drop the data from the incoming
957 * segment. If it provides all of our data, drop us.
958 */
959 if (p != NULL) {
960 i = ntohs(p->ipqe_ip->ip_off) + ntohs(p->ipqe_ip->ip_len) -
961 ntohs(ipqe->ipqe_ip->ip_off);
962 if (i > 0) {
963 if (i >= ntohs(ipqe->ipqe_ip->ip_len))
964 goto dropfrag;
965 m_adj(ipqe->ipqe_m, i);
966 ipqe->ipqe_ip->ip_off =
967 htons(ntohs(ipqe->ipqe_ip->ip_off) + i);
968 ipqe->ipqe_ip->ip_len =
969 htons(ntohs(ipqe->ipqe_ip->ip_len) - i);
970 }
971 }
972
973 /*
974 * While we overlap succeeding segments trim them or,
975 * if they are completely covered, dequeue them.
976 */
977 for (; q != NULL &&
978 ntohs(ipqe->ipqe_ip->ip_off) + ntohs(ipqe->ipqe_ip->ip_len) >
979 ntohs(q->ipqe_ip->ip_off); q = nq) {
980 i = (ntohs(ipqe->ipqe_ip->ip_off) +
981 ntohs(ipqe->ipqe_ip->ip_len)) - ntohs(q->ipqe_ip->ip_off);
982 if (i < ntohs(q->ipqe_ip->ip_len)) {
983 q->ipqe_ip->ip_len =
984 htons(ntohs(q->ipqe_ip->ip_len) - i);
985 q->ipqe_ip->ip_off =
986 htons(ntohs(q->ipqe_ip->ip_off) + i);
987 m_adj(q->ipqe_m, i);
988 break;
989 }
990 nq = TAILQ_NEXT(q, ipqe_q);
991 m_freem(q->ipqe_m);
992 TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
993 pool_put(&ipqent_pool, q);
994 }
995
996 insert:
997 /*
998 * Stick new segment in its place;
999 * check for complete reassembly.
1000 */
1001 if (p == NULL) {
1002 TAILQ_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
1003 } else {
1004 TAILQ_INSERT_AFTER(&fp->ipq_fragq, p, ipqe, ipqe_q);
1005 }
1006 next = 0;
1007 for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
1008 p = q, q = TAILQ_NEXT(q, ipqe_q)) {
1009 if (ntohs(q->ipqe_ip->ip_off) != next)
1010 return (0);
1011 next += ntohs(q->ipqe_ip->ip_len);
1012 }
1013 if (p->ipqe_mff)
1014 return (0);
1015
1016 /*
1017 * Reassembly is complete. Check for a bogus message size and
1018 * concatenate fragments.
1019 */
1020 q = TAILQ_FIRST(&fp->ipq_fragq);
1021 ip = q->ipqe_ip;
1022 if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
1023 ipstat.ips_toolong++;
1024 ip_freef(fp);
1025 return (0);
1026 }
1027 m = q->ipqe_m;
1028 t = m->m_next;
1029 m->m_next = 0;
1030 m_cat(m, t);
1031 nq = TAILQ_NEXT(q, ipqe_q);
1032 pool_put(&ipqent_pool, q);
1033 for (q = nq; q != NULL; q = nq) {
1034 t = q->ipqe_m;
1035 nq = TAILQ_NEXT(q, ipqe_q);
1036 pool_put(&ipqent_pool, q);
1037 m_cat(m, t);
1038 }
1039
1040 /*
1041 * Create header for new ip packet by
1042 * modifying header of first packet;
1043 * dequeue and discard fragment reassembly header.
1044 * Make header visible.
1045 */
1046 ip->ip_len = htons(next);
1047 ip->ip_src = fp->ipq_src;
1048 ip->ip_dst = fp->ipq_dst;
1049 LIST_REMOVE(fp, ipq_q);
1050 FREE(fp, M_FTABLE);
1051 ip_nfragpackets--;
1052 m->m_len += (ip->ip_hl << 2);
1053 m->m_data -= (ip->ip_hl << 2);
1054 /* some debugging cruft by sklower, below, will go away soon */
1055 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1056 int plen = 0;
1057 for (t = m; t; t = t->m_next)
1058 plen += t->m_len;
1059 m->m_pkthdr.len = plen;
1060 }
1061 return (m);
1062
1063 dropfrag:
1064 ipstat.ips_fragdropped++;
1065 m_freem(m);
1066 pool_put(&ipqent_pool, ipqe);
1067 return (0);
1068 }
1069
1070 /*
1071 * Free a fragment reassembly header and all
1072 * associated datagrams.
1073 */
1074 void
1075 ip_freef(fp)
1076 struct ipq *fp;
1077 {
1078 struct ipqent *q, *p;
1079
1080 IPQ_LOCK_CHECK();
1081
1082 for (q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL; q = p) {
1083 p = TAILQ_NEXT(q, ipqe_q);
1084 m_freem(q->ipqe_m);
1085 TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1086 pool_put(&ipqent_pool, q);
1087 }
1088 LIST_REMOVE(fp, ipq_q);
1089 FREE(fp, M_FTABLE);
1090 ip_nfragpackets--;
1091 }
1092
1093 /*
1094 * IP timer processing;
1095 * if a timer expires on a reassembly
1096 * queue, discard it.
1097 */
1098 void
1099 ip_slowtimo()
1100 {
1101 struct ipq *fp, *nfp;
1102 int s = splsoftnet();
1103
1104 IPQ_LOCK();
1105 for (fp = LIST_FIRST(&ipq); fp != NULL; fp = nfp) {
1106 nfp = LIST_NEXT(fp, ipq_q);
1107 if (--fp->ipq_ttl == 0) {
1108 ipstat.ips_fragtimeout++;
1109 ip_freef(fp);
1110 }
1111 }
1112 /*
1113 * If we are over the maximum number of fragments
1114 * (due to the limit being lowered), drain off
1115 * enough to get down to the new limit.
1116 */
1117 if (ip_maxfragpackets < 0)
1118 ;
1119 else {
1120 while (ip_nfragpackets > ip_maxfragpackets && LIST_FIRST(&ipq))
1121 ip_freef(LIST_FIRST(&ipq));
1122 }
1123 IPQ_UNLOCK();
1124 #ifdef GATEWAY
1125 ipflow_slowtimo();
1126 #endif
1127 splx(s);
1128 }
1129
1130 /*
1131 * Drain off all datagram fragments.
1132 */
1133 void
1134 ip_drain()
1135 {
1136
1137 /*
1138 * We may be called from a device's interrupt context. If
1139 * the ipq is already busy, just bail out now.
1140 */
1141 if (ipq_lock_try() == 0)
1142 return;
1143
1144 while (LIST_FIRST(&ipq) != NULL) {
1145 ipstat.ips_fragdropped++;
1146 ip_freef(LIST_FIRST(&ipq));
1147 }
1148
1149 IPQ_UNLOCK();
1150 }
1151
1152 /*
1153 * Do option processing on a datagram,
1154 * possibly discarding it if bad options are encountered,
1155 * or forwarding it if source-routed.
1156 * Returns 1 if packet has been forwarded/freed,
1157 * 0 if the packet should be processed further.
1158 */
1159 int
1160 ip_dooptions(m)
1161 struct mbuf *m;
1162 {
1163 struct ip *ip = mtod(m, struct ip *);
1164 u_char *cp, *cp0;
1165 struct ip_timestamp *ipt;
1166 struct in_ifaddr *ia;
1167 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1168 struct in_addr dst;
1169 n_time ntime;
1170
1171 dst = ip->ip_dst;
1172 cp = (u_char *)(ip + 1);
1173 cnt = (ip->ip_hl << 2) - sizeof (struct ip);
1174 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1175 opt = cp[IPOPT_OPTVAL];
1176 if (opt == IPOPT_EOL)
1177 break;
1178 if (opt == IPOPT_NOP)
1179 optlen = 1;
1180 else {
1181 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1182 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1183 goto bad;
1184 }
1185 optlen = cp[IPOPT_OLEN];
1186 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1187 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1188 goto bad;
1189 }
1190 }
1191 switch (opt) {
1192
1193 default:
1194 break;
1195
1196 /*
1197 * Source routing with record.
1198 * Find interface with current destination address.
1199 * If none on this machine then drop if strictly routed,
1200 * or do nothing if loosely routed.
1201 * Record interface address and bring up next address
1202 * component. If strictly routed make sure next
1203 * address is on directly accessible net.
1204 */
1205 case IPOPT_LSRR:
1206 case IPOPT_SSRR:
1207 if (ip_allowsrcrt == 0) {
1208 type = ICMP_UNREACH;
1209 code = ICMP_UNREACH_NET_PROHIB;
1210 goto bad;
1211 }
1212 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1213 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1214 goto bad;
1215 }
1216 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1217 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1218 goto bad;
1219 }
1220 ipaddr.sin_addr = ip->ip_dst;
1221 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1222 if (ia == 0) {
1223 if (opt == IPOPT_SSRR) {
1224 type = ICMP_UNREACH;
1225 code = ICMP_UNREACH_SRCFAIL;
1226 goto bad;
1227 }
1228 /*
1229 * Loose routing, and not at next destination
1230 * yet; nothing to do except forward.
1231 */
1232 break;
1233 }
1234 off--; /* 0 origin */
1235 if ((off + sizeof(struct in_addr)) > optlen) {
1236 /*
1237 * End of source route. Should be for us.
1238 */
1239 save_rte(cp, ip->ip_src);
1240 break;
1241 }
1242 /*
1243 * locate outgoing interface
1244 */
1245 bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
1246 sizeof(ipaddr.sin_addr));
1247 if (opt == IPOPT_SSRR)
1248 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1249 else
1250 ia = ip_rtaddr(ipaddr.sin_addr);
1251 if (ia == 0) {
1252 type = ICMP_UNREACH;
1253 code = ICMP_UNREACH_SRCFAIL;
1254 goto bad;
1255 }
1256 ip->ip_dst = ipaddr.sin_addr;
1257 bcopy((caddr_t)&ia->ia_addr.sin_addr,
1258 (caddr_t)(cp + off), sizeof(struct in_addr));
1259 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1260 /*
1261 * Let ip_intr's mcast routing check handle mcast pkts
1262 */
1263 forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1264 break;
1265
1266 case IPOPT_RR:
1267 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1268 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1269 goto bad;
1270 }
1271 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1272 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1273 goto bad;
1274 }
1275 /*
1276 * If no space remains, ignore.
1277 */
1278 off--; /* 0 origin */
1279 if ((off + sizeof(struct in_addr)) > optlen)
1280 break;
1281 bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
1282 sizeof(ipaddr.sin_addr));
1283 /*
1284 * locate outgoing interface; if we're the destination,
1285 * use the incoming interface (should be same).
1286 */
1287 if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
1288 == NULL &&
1289 (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1290 type = ICMP_UNREACH;
1291 code = ICMP_UNREACH_HOST;
1292 goto bad;
1293 }
1294 bcopy((caddr_t)&ia->ia_addr.sin_addr,
1295 (caddr_t)(cp + off), sizeof(struct in_addr));
1296 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1297 break;
1298
1299 case IPOPT_TS:
1300 code = cp - (u_char *)ip;
1301 ipt = (struct ip_timestamp *)cp;
1302 if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1303 code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1304 goto bad;
1305 }
1306 if (ipt->ipt_ptr < 5) {
1307 code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1308 goto bad;
1309 }
1310 if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1311 if (++ipt->ipt_oflw == 0) {
1312 code = (u_char *)&ipt->ipt_ptr -
1313 (u_char *)ip;
1314 goto bad;
1315 }
1316 break;
1317 }
1318 cp0 = (cp + ipt->ipt_ptr - 1);
1319 switch (ipt->ipt_flg) {
1320
1321 case IPOPT_TS_TSONLY:
1322 break;
1323
1324 case IPOPT_TS_TSANDADDR:
1325 if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1326 sizeof(struct in_addr) > ipt->ipt_len) {
1327 code = (u_char *)&ipt->ipt_ptr -
1328 (u_char *)ip;
1329 goto bad;
1330 }
1331 ipaddr.sin_addr = dst;
1332 ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
1333 m->m_pkthdr.rcvif));
1334 if (ia == 0)
1335 continue;
1336 bcopy(&ia->ia_addr.sin_addr,
1337 cp0, sizeof(struct in_addr));
1338 ipt->ipt_ptr += sizeof(struct in_addr);
1339 break;
1340
1341 case IPOPT_TS_PRESPEC:
1342 if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1343 sizeof(struct in_addr) > ipt->ipt_len) {
1344 code = (u_char *)&ipt->ipt_ptr -
1345 (u_char *)ip;
1346 goto bad;
1347 }
1348 bcopy(cp0, &ipaddr.sin_addr,
1349 sizeof(struct in_addr));
1350 if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
1351 == NULL)
1352 continue;
1353 ipt->ipt_ptr += sizeof(struct in_addr);
1354 break;
1355
1356 default:
1357 /* XXX can't take &ipt->ipt_flg */
1358 code = (u_char *)&ipt->ipt_ptr -
1359 (u_char *)ip + 1;
1360 goto bad;
1361 }
1362 ntime = iptime();
1363 cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1364 bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1,
1365 sizeof(n_time));
1366 ipt->ipt_ptr += sizeof(n_time);
1367 }
1368 }
1369 if (forward) {
1370 if (ip_forwsrcrt == 0) {
1371 type = ICMP_UNREACH;
1372 code = ICMP_UNREACH_SRCFAIL;
1373 goto bad;
1374 }
1375 ip_forward(m, 1);
1376 return (1);
1377 }
1378 return (0);
1379 bad:
1380 icmp_error(m, type, code, 0, 0);
1381 ipstat.ips_badoptions++;
1382 return (1);
1383 }
1384
1385 /*
1386 * Given address of next destination (final or next hop),
1387 * return internet address info of interface to be used to get there.
1388 */
1389 struct in_ifaddr *
1390 ip_rtaddr(dst)
1391 struct in_addr dst;
1392 {
1393 struct sockaddr_in *sin;
1394
1395 sin = satosin(&ipforward_rt.ro_dst);
1396
1397 if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1398 if (ipforward_rt.ro_rt) {
1399 RTFREE(ipforward_rt.ro_rt);
1400 ipforward_rt.ro_rt = 0;
1401 }
1402 sin->sin_family = AF_INET;
1403 sin->sin_len = sizeof(*sin);
1404 sin->sin_addr = dst;
1405
1406 rtalloc(&ipforward_rt);
1407 }
1408 if (ipforward_rt.ro_rt == 0)
1409 return ((struct in_ifaddr *)0);
1410 return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1411 }
1412
1413 /*
1414 * Save incoming source route for use in replies,
1415 * to be picked up later by ip_srcroute if the receiver is interested.
1416 */
1417 void
1418 save_rte(option, dst)
1419 u_char *option;
1420 struct in_addr dst;
1421 {
1422 unsigned olen;
1423
1424 olen = option[IPOPT_OLEN];
1425 #ifdef DIAGNOSTIC
1426 if (ipprintfs)
1427 printf("save_rte: olen %d\n", olen);
1428 #endif /* 0 */
1429 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1430 return;
1431 bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1432 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1433 ip_srcrt.dst = dst;
1434 }
1435
1436 /*
1437 * Retrieve incoming source route for use in replies,
1438 * in the same form used by setsockopt.
1439 * The first hop is placed before the options, will be removed later.
1440 */
1441 struct mbuf *
1442 ip_srcroute()
1443 {
1444 struct in_addr *p, *q;
1445 struct mbuf *m;
1446
1447 if (ip_nhops == 0)
1448 return ((struct mbuf *)0);
1449 m = m_get(M_DONTWAIT, MT_SOOPTS);
1450 if (m == 0)
1451 return ((struct mbuf *)0);
1452
1453 MCLAIM(m, &inetdomain.dom_mowner);
1454 #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1455
1456 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1457 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1458 OPTSIZ;
1459 #ifdef DIAGNOSTIC
1460 if (ipprintfs)
1461 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1462 #endif
1463
1464 /*
1465 * First save first hop for return route
1466 */
1467 p = &ip_srcrt.route[ip_nhops - 1];
1468 *(mtod(m, struct in_addr *)) = *p--;
1469 #ifdef DIAGNOSTIC
1470 if (ipprintfs)
1471 printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1472 #endif
1473
1474 /*
1475 * Copy option fields and padding (nop) to mbuf.
1476 */
1477 ip_srcrt.nop = IPOPT_NOP;
1478 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1479 bcopy((caddr_t)&ip_srcrt.nop,
1480 mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1481 q = (struct in_addr *)(mtod(m, caddr_t) +
1482 sizeof(struct in_addr) + OPTSIZ);
1483 #undef OPTSIZ
1484 /*
1485 * Record return path as an IP source route,
1486 * reversing the path (pointers are now aligned).
1487 */
1488 while (p >= ip_srcrt.route) {
1489 #ifdef DIAGNOSTIC
1490 if (ipprintfs)
1491 printf(" %x", ntohl(q->s_addr));
1492 #endif
1493 *q++ = *p--;
1494 }
1495 /*
1496 * Last hop goes to final destination.
1497 */
1498 *q = ip_srcrt.dst;
1499 #ifdef DIAGNOSTIC
1500 if (ipprintfs)
1501 printf(" %x\n", ntohl(q->s_addr));
1502 #endif
1503 return (m);
1504 }
1505
1506 /*
1507 * Strip out IP options, at higher
1508 * level protocol in the kernel.
1509 * Second argument is buffer to which options
1510 * will be moved, and return value is their length.
1511 * XXX should be deleted; last arg currently ignored.
1512 */
1513 void
1514 ip_stripoptions(m, mopt)
1515 struct mbuf *m;
1516 struct mbuf *mopt;
1517 {
1518 int i;
1519 struct ip *ip = mtod(m, struct ip *);
1520 caddr_t opts;
1521 int olen;
1522
1523 olen = (ip->ip_hl << 2) - sizeof (struct ip);
1524 opts = (caddr_t)(ip + 1);
1525 i = m->m_len - (sizeof (struct ip) + olen);
1526 bcopy(opts + olen, opts, (unsigned)i);
1527 m->m_len -= olen;
1528 if (m->m_flags & M_PKTHDR)
1529 m->m_pkthdr.len -= olen;
1530 ip->ip_len = htons(ntohs(ip->ip_len) - olen);
1531 ip->ip_hl = sizeof (struct ip) >> 2;
1532 }
1533
1534 const int inetctlerrmap[PRC_NCMDS] = {
1535 0, 0, 0, 0,
1536 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1537 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1538 EMSGSIZE, EHOSTUNREACH, 0, 0,
1539 0, 0, 0, 0,
1540 ENOPROTOOPT
1541 };
1542
1543 /*
1544 * Forward a packet. If some error occurs return the sender
1545 * an icmp packet. Note we can't always generate a meaningful
1546 * icmp message because icmp doesn't have a large enough repertoire
1547 * of codes and types.
1548 *
1549 * If not forwarding, just drop the packet. This could be confusing
1550 * if ipforwarding was zero but some routing protocol was advancing
1551 * us as a gateway to somewhere. However, we must let the routing
1552 * protocol deal with that.
1553 *
1554 * The srcrt parameter indicates whether the packet is being forwarded
1555 * via a source route.
1556 */
1557 void
1558 ip_forward(m, srcrt)
1559 struct mbuf *m;
1560 int srcrt;
1561 {
1562 struct ip *ip = mtod(m, struct ip *);
1563 struct sockaddr_in *sin;
1564 struct rtentry *rt;
1565 int error, type = 0, code = 0;
1566 struct mbuf *mcopy;
1567 n_long dest;
1568 struct ifnet *destifp;
1569 #ifdef IPSEC
1570 struct ifnet dummyifp;
1571 #endif
1572
1573 /*
1574 * We are now in the output path.
1575 */
1576 MCLAIM(m, &ip_tx_mowner);
1577
1578 /*
1579 * Clear any in-bound checksum flags for this packet.
1580 */
1581 m->m_pkthdr.csum_flags = 0;
1582
1583 dest = 0;
1584 #ifdef DIAGNOSTIC
1585 if (ipprintfs)
1586 printf("forward: src %2.2x dst %2.2x ttl %x\n",
1587 ntohl(ip->ip_src.s_addr),
1588 ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1589 #endif
1590 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1591 ipstat.ips_cantforward++;
1592 m_freem(m);
1593 return;
1594 }
1595 if (ip->ip_ttl <= IPTTLDEC) {
1596 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1597 return;
1598 }
1599 ip->ip_ttl -= IPTTLDEC;
1600
1601 sin = satosin(&ipforward_rt.ro_dst);
1602 if ((rt = ipforward_rt.ro_rt) == 0 ||
1603 !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1604 if (ipforward_rt.ro_rt) {
1605 RTFREE(ipforward_rt.ro_rt);
1606 ipforward_rt.ro_rt = 0;
1607 }
1608 sin->sin_family = AF_INET;
1609 sin->sin_len = sizeof(struct sockaddr_in);
1610 sin->sin_addr = ip->ip_dst;
1611
1612 rtalloc(&ipforward_rt);
1613 if (ipforward_rt.ro_rt == 0) {
1614 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1615 return;
1616 }
1617 rt = ipforward_rt.ro_rt;
1618 }
1619
1620 /*
1621 * Save at most 68 bytes of the packet in case
1622 * we need to generate an ICMP message to the src.
1623 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1624 */
1625 mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1626 if (mcopy)
1627 mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1628
1629 /*
1630 * If forwarding packet using same interface that it came in on,
1631 * perhaps should send a redirect to sender to shortcut a hop.
1632 * Only send redirect if source is sending directly to us,
1633 * and if packet was not source routed (or has any options).
1634 * Also, don't send redirect if forwarding using a default route
1635 * or a route modified by a redirect.
1636 */
1637 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1638 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1639 !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1640 ipsendredirects && !srcrt) {
1641 if (rt->rt_ifa &&
1642 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1643 ifatoia(rt->rt_ifa)->ia_subnet) {
1644 if (rt->rt_flags & RTF_GATEWAY)
1645 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1646 else
1647 dest = ip->ip_dst.s_addr;
1648 /*
1649 * Router requirements says to only send host
1650 * redirects.
1651 */
1652 type = ICMP_REDIRECT;
1653 code = ICMP_REDIRECT_HOST;
1654 #ifdef DIAGNOSTIC
1655 if (ipprintfs)
1656 printf("redirect (%d) to %x\n", code,
1657 (u_int32_t)dest);
1658 #endif
1659 }
1660 }
1661
1662 #ifdef IPSEC
1663 /* Don't lookup socket in forwarding case */
1664 (void)ipsec_setsocket(m, NULL);
1665 #endif
1666 error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1667 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1668 if (error)
1669 ipstat.ips_cantforward++;
1670 else {
1671 ipstat.ips_forward++;
1672 if (type)
1673 ipstat.ips_redirectsent++;
1674 else {
1675 if (mcopy) {
1676 #ifdef GATEWAY
1677 if (mcopy->m_flags & M_CANFASTFWD)
1678 ipflow_create(&ipforward_rt, mcopy);
1679 #endif
1680 m_freem(mcopy);
1681 }
1682 return;
1683 }
1684 }
1685 if (mcopy == NULL)
1686 return;
1687 destifp = NULL;
1688
1689 switch (error) {
1690
1691 case 0: /* forwarded, but need redirect */
1692 /* type, code set above */
1693 break;
1694
1695 case ENETUNREACH: /* shouldn't happen, checked above */
1696 case EHOSTUNREACH:
1697 case ENETDOWN:
1698 case EHOSTDOWN:
1699 default:
1700 type = ICMP_UNREACH;
1701 code = ICMP_UNREACH_HOST;
1702 break;
1703
1704 case EMSGSIZE:
1705 type = ICMP_UNREACH;
1706 code = ICMP_UNREACH_NEEDFRAG;
1707 #ifndef IPSEC
1708 if (ipforward_rt.ro_rt)
1709 destifp = ipforward_rt.ro_rt->rt_ifp;
1710 #else
1711 /*
1712 * If the packet is routed over IPsec tunnel, tell the
1713 * originator the tunnel MTU.
1714 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1715 * XXX quickhack!!!
1716 */
1717 if (ipforward_rt.ro_rt) {
1718 struct secpolicy *sp;
1719 int ipsecerror;
1720 size_t ipsechdr;
1721 struct route *ro;
1722
1723 sp = ipsec4_getpolicybyaddr(mcopy,
1724 IPSEC_DIR_OUTBOUND,
1725 IP_FORWARDING,
1726 &ipsecerror);
1727
1728 if (sp == NULL)
1729 destifp = ipforward_rt.ro_rt->rt_ifp;
1730 else {
1731 /* count IPsec header size */
1732 ipsechdr = ipsec4_hdrsiz(mcopy,
1733 IPSEC_DIR_OUTBOUND,
1734 NULL);
1735
1736 /*
1737 * find the correct route for outer IPv4
1738 * header, compute tunnel MTU.
1739 *
1740 * XXX BUG ALERT
1741 * The "dummyifp" code relies upon the fact
1742 * that icmp_error() touches only ifp->if_mtu.
1743 */
1744 /*XXX*/
1745 destifp = NULL;
1746 if (sp->req != NULL
1747 && sp->req->sav != NULL
1748 && sp->req->sav->sah != NULL) {
1749 ro = &sp->req->sav->sah->sa_route;
1750 if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1751 dummyifp.if_mtu =
1752 ro->ro_rt->rt_rmx.rmx_mtu ?
1753 ro->ro_rt->rt_rmx.rmx_mtu :
1754 ro->ro_rt->rt_ifp->if_mtu;
1755 dummyifp.if_mtu -= ipsechdr;
1756 destifp = &dummyifp;
1757 }
1758 }
1759
1760 key_freesp(sp);
1761 }
1762 }
1763 #endif /*IPSEC*/
1764 ipstat.ips_cantfrag++;
1765 break;
1766
1767 case ENOBUFS:
1768 #if 1
1769 /*
1770 * a router should not generate ICMP_SOURCEQUENCH as
1771 * required in RFC1812 Requirements for IP Version 4 Routers.
1772 * source quench could be a big problem under DoS attacks,
1773 * or if the underlying interface is rate-limited.
1774 */
1775 if (mcopy)
1776 m_freem(mcopy);
1777 return;
1778 #else
1779 type = ICMP_SOURCEQUENCH;
1780 code = 0;
1781 break;
1782 #endif
1783 }
1784 icmp_error(mcopy, type, code, dest, destifp);
1785 }
1786
1787 void
1788 ip_savecontrol(inp, mp, ip, m)
1789 struct inpcb *inp;
1790 struct mbuf **mp;
1791 struct ip *ip;
1792 struct mbuf *m;
1793 {
1794
1795 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1796 struct timeval tv;
1797
1798 microtime(&tv);
1799 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1800 SCM_TIMESTAMP, SOL_SOCKET);
1801 if (*mp)
1802 mp = &(*mp)->m_next;
1803 }
1804 if (inp->inp_flags & INP_RECVDSTADDR) {
1805 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1806 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1807 if (*mp)
1808 mp = &(*mp)->m_next;
1809 }
1810 #ifdef notyet
1811 /*
1812 * XXX
1813 * Moving these out of udp_input() made them even more broken
1814 * than they already were.
1815 * - fenner (at) parc.xerox.com
1816 */
1817 /* options were tossed already */
1818 if (inp->inp_flags & INP_RECVOPTS) {
1819 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1820 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1821 if (*mp)
1822 mp = &(*mp)->m_next;
1823 }
1824 /* ip_srcroute doesn't do what we want here, need to fix */
1825 if (inp->inp_flags & INP_RECVRETOPTS) {
1826 *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1827 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1828 if (*mp)
1829 mp = &(*mp)->m_next;
1830 }
1831 #endif
1832 if (inp->inp_flags & INP_RECVIF) {
1833 struct sockaddr_dl sdl;
1834
1835 sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1836 sdl.sdl_family = AF_LINK;
1837 sdl.sdl_index = m->m_pkthdr.rcvif ?
1838 m->m_pkthdr.rcvif->if_index : 0;
1839 sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1840 *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1841 IP_RECVIF, IPPROTO_IP);
1842 if (*mp)
1843 mp = &(*mp)->m_next;
1844 }
1845 }
1846
1847 int
1848 ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1849 int *name;
1850 u_int namelen;
1851 void *oldp;
1852 size_t *oldlenp;
1853 void *newp;
1854 size_t newlen;
1855 {
1856 extern int subnetsarelocal, hostzeroisbroadcast;
1857
1858 int error, old;
1859
1860 /* All sysctl names at this level are terminal. */
1861 if (namelen != 1)
1862 return (ENOTDIR);
1863
1864 switch (name[0]) {
1865 case IPCTL_FORWARDING:
1866 return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1867 case IPCTL_SENDREDIRECTS:
1868 return (sysctl_int(oldp, oldlenp, newp, newlen,
1869 &ipsendredirects));
1870 case IPCTL_DEFTTL:
1871 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1872 #ifdef notyet
1873 case IPCTL_DEFMTU:
1874 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1875 #endif
1876 case IPCTL_FORWSRCRT:
1877 /* Don't allow this to change in a secure environment. */
1878 if (securelevel > 0)
1879 return (sysctl_rdint(oldp, oldlenp, newp,
1880 ip_forwsrcrt));
1881 else
1882 return (sysctl_int(oldp, oldlenp, newp, newlen,
1883 &ip_forwsrcrt));
1884 case IPCTL_DIRECTEDBCAST:
1885 return (sysctl_int(oldp, oldlenp, newp, newlen,
1886 &ip_directedbcast));
1887 case IPCTL_ALLOWSRCRT:
1888 return (sysctl_int(oldp, oldlenp, newp, newlen,
1889 &ip_allowsrcrt));
1890 case IPCTL_SUBNETSARELOCAL:
1891 return (sysctl_int(oldp, oldlenp, newp, newlen,
1892 &subnetsarelocal));
1893 case IPCTL_MTUDISC:
1894 error = sysctl_int(oldp, oldlenp, newp, newlen,
1895 &ip_mtudisc);
1896 if (error == 0 && ip_mtudisc == 0)
1897 rt_timer_queue_remove_all(ip_mtudisc_timeout_q, TRUE);
1898 return error;
1899 case IPCTL_ANONPORTMIN:
1900 old = anonportmin;
1901 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1902 if (anonportmin >= anonportmax || anonportmin < 0
1903 || anonportmin > 65535
1904 #ifndef IPNOPRIVPORTS
1905 || anonportmin < IPPORT_RESERVED
1906 #endif
1907 ) {
1908 anonportmin = old;
1909 return (EINVAL);
1910 }
1911 return (error);
1912 case IPCTL_ANONPORTMAX:
1913 old = anonportmax;
1914 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1915 if (anonportmin >= anonportmax || anonportmax < 0
1916 || anonportmax > 65535
1917 #ifndef IPNOPRIVPORTS
1918 || anonportmax < IPPORT_RESERVED
1919 #endif
1920 ) {
1921 anonportmax = old;
1922 return (EINVAL);
1923 }
1924 return (error);
1925 case IPCTL_MTUDISCTIMEOUT:
1926 old = ip_mtudisc_timeout;
1927 error = sysctl_int(oldp, oldlenp, newp, newlen,
1928 &ip_mtudisc_timeout);
1929 if (ip_mtudisc_timeout < 0) {
1930 ip_mtudisc_timeout = old;
1931 return (EINVAL);
1932 }
1933 if (error == 0)
1934 rt_timer_queue_change(ip_mtudisc_timeout_q,
1935 ip_mtudisc_timeout);
1936 return (error);
1937 #ifdef GATEWAY
1938 case IPCTL_MAXFLOWS:
1939 {
1940 int s;
1941
1942 error = sysctl_int(oldp, oldlenp, newp, newlen,
1943 &ip_maxflows);
1944 s = splsoftnet();
1945 ipflow_reap(0);
1946 splx(s);
1947 return (error);
1948 }
1949 #endif
1950 case IPCTL_HOSTZEROBROADCAST:
1951 return (sysctl_int(oldp, oldlenp, newp, newlen,
1952 &hostzeroisbroadcast));
1953 #if NGIF > 0
1954 case IPCTL_GIF_TTL:
1955 return (sysctl_int(oldp, oldlenp, newp, newlen,
1956 &ip_gif_ttl));
1957 #endif
1958
1959 #if NGRE > 0
1960 case IPCTL_GRE_TTL:
1961 return (sysctl_int(oldp, oldlenp, newp, newlen,
1962 &ip_gre_ttl));
1963 #endif
1964
1965 #ifndef IPNOPRIVPORTS
1966 case IPCTL_LOWPORTMIN:
1967 old = lowportmin;
1968 error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmin);
1969 if (lowportmin >= lowportmax
1970 || lowportmin > IPPORT_RESERVEDMAX
1971 || lowportmin < IPPORT_RESERVEDMIN
1972 ) {
1973 lowportmin = old;
1974 return (EINVAL);
1975 }
1976 return (error);
1977 case IPCTL_LOWPORTMAX:
1978 old = lowportmax;
1979 error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmax);
1980 if (lowportmin >= lowportmax
1981 || lowportmax > IPPORT_RESERVEDMAX
1982 || lowportmax < IPPORT_RESERVEDMIN
1983 ) {
1984 lowportmax = old;
1985 return (EINVAL);
1986 }
1987 return (error);
1988 #endif
1989
1990 case IPCTL_MAXFRAGPACKETS:
1991 return (sysctl_int(oldp, oldlenp, newp, newlen,
1992 &ip_maxfragpackets));
1993
1994 case IPCTL_CHECKINTERFACE:
1995 return (sysctl_int(oldp, oldlenp, newp, newlen,
1996 &ip_checkinterface));
1997 default:
1998 return (EOPNOTSUPP);
1999 }
2000 /* NOTREACHED */
2001 }
2002