ip_input.c revision 1.82.2.7 1 /* $NetBSD: ip_input.c,v 1.82.2.7 2001/05/30 09:44:09 he Exp $ */
2
3 /*-
4 * Copyright (c) 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Public Access Networks Corporation ("Panix"). It was developed under
9 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 /*
41 * Copyright (c) 1982, 1986, 1988, 1993
42 * The Regents of the University of California. All rights reserved.
43 *
44 * Redistribution and use in source and binary forms, with or without
45 * modification, are permitted provided that the following conditions
46 * are met:
47 * 1. Redistributions of source code must retain the above copyright
48 * notice, this list of conditions and the following disclaimer.
49 * 2. Redistributions in binary form must reproduce the above copyright
50 * notice, this list of conditions and the following disclaimer in the
51 * documentation and/or other materials provided with the distribution.
52 * 3. All advertising materials mentioning features or use of this software
53 * must display the following acknowledgement:
54 * This product includes software developed by the University of
55 * California, Berkeley and its contributors.
56 * 4. Neither the name of the University nor the names of its contributors
57 * may be used to endorse or promote products derived from this software
58 * without specific prior written permission.
59 *
60 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
61 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
62 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
63 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
64 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
65 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
66 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
70 * SUCH DAMAGE.
71 *
72 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
73 */
74
75 #include "opt_gateway.h"
76 #include "opt_pfil_hooks.h"
77 #include "opt_mrouting.h"
78
79 #include <sys/param.h>
80 #include <sys/systm.h>
81 #include <sys/malloc.h>
82 #include <sys/mbuf.h>
83 #include <sys/domain.h>
84 #include <sys/protosw.h>
85 #include <sys/socket.h>
86 #include <sys/socketvar.h>
87 #include <sys/errno.h>
88 #include <sys/time.h>
89 #include <sys/kernel.h>
90 #include <sys/proc.h>
91 #include <sys/pool.h>
92
93 #include <vm/vm.h>
94 #include <sys/sysctl.h>
95
96 #include <net/if.h>
97 #include <net/if_dl.h>
98 #include <net/route.h>
99 #include <net/pfil.h>
100
101 #include <netinet/in.h>
102 #include <netinet/in_systm.h>
103 #include <netinet/ip.h>
104 #include <netinet/in_pcb.h>
105 #include <netinet/in_var.h>
106 #include <netinet/ip_var.h>
107 #include <netinet/ip_icmp.h>
108
109 #ifndef IPFORWARDING
110 #ifdef GATEWAY
111 #define IPFORWARDING 1 /* forward IP packets not for us */
112 #else /* GATEWAY */
113 #define IPFORWARDING 0 /* don't forward IP packets not for us */
114 #endif /* GATEWAY */
115 #endif /* IPFORWARDING */
116 #ifndef IPSENDREDIRECTS
117 #define IPSENDREDIRECTS 1
118 #endif
119 #ifndef IPFORWSRCRT
120 #define IPFORWSRCRT 1 /* forward source-routed packets */
121 #endif
122 #ifndef IPALLOWSRCRT
123 #define IPALLOWSRCRT 1 /* allow source-routed packets */
124 #endif
125 #ifndef IPMTUDISC
126 #define IPMTUDISC 0
127 #endif
128 #ifndef IPMTUDISCTIMEOUT
129 #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
130 #endif
131
132 /*
133 * Note: DIRECTED_BROADCAST is handled this way so that previous
134 * configuration using this option will Just Work.
135 */
136 #ifndef IPDIRECTEDBCAST
137 #ifdef DIRECTED_BROADCAST
138 #define IPDIRECTEDBCAST 1
139 #else
140 #define IPDIRECTEDBCAST 0
141 #endif /* DIRECTED_BROADCAST */
142 #endif /* IPDIRECTEDBCAST */
143 int ipforwarding = IPFORWARDING;
144 int ipsendredirects = IPSENDREDIRECTS;
145 int ip_defttl = IPDEFTTL;
146 int ip_forwsrcrt = IPFORWSRCRT;
147 int ip_directedbcast = IPDIRECTEDBCAST;
148 int ip_allowsrcrt = IPALLOWSRCRT;
149 int ip_mtudisc = IPMTUDISC;
150 u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
151 #ifdef DIAGNOSTIC
152 int ipprintfs = 0;
153 #endif
154
155 struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
156
157 extern struct domain inetdomain;
158 extern struct protosw inetsw[];
159 u_char ip_protox[IPPROTO_MAX];
160 int ipqmaxlen = IFQ_MAXLEN;
161 struct in_ifaddrhead in_ifaddr;
162 struct in_ifaddrhashhead *in_ifaddrhashtbl;
163 struct ifqueue ipintrq;
164 struct ipstat ipstat;
165 u_int16_t ip_id;
166 int ip_defttl;
167
168 struct ipqhead ipq;
169 int ipq_locked;
170 int ip_nfragpackets = 0;
171 int ip_maxfragpackets = 200;
172
173 static __inline int ipq_lock_try __P((void));
174 static __inline void ipq_unlock __P((void));
175
176 static __inline int
177 ipq_lock_try()
178 {
179 int s;
180
181 s = splimp();
182 if (ipq_locked) {
183 splx(s);
184 return (0);
185 }
186 ipq_locked = 1;
187 splx(s);
188 return (1);
189 }
190
191 static __inline void
192 ipq_unlock()
193 {
194 int s;
195
196 s = splimp();
197 ipq_locked = 0;
198 splx(s);
199 }
200
201 #ifdef DIAGNOSTIC
202 #define IPQ_LOCK() \
203 do { \
204 if (ipq_lock_try() == 0) { \
205 printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
206 panic("ipq_lock"); \
207 } \
208 } while (0)
209 #define IPQ_LOCK_CHECK() \
210 do { \
211 if (ipq_locked == 0) { \
212 printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
213 panic("ipq lock check"); \
214 } \
215 } while (0)
216 #else
217 #define IPQ_LOCK() (void) ipq_lock_try()
218 #define IPQ_LOCK_CHECK() /* nothing */
219 #endif
220
221 #define IPQ_UNLOCK() ipq_unlock()
222
223 struct pool ipqent_pool;
224
225 /*
226 * We need to save the IP options in case a protocol wants to respond
227 * to an incoming packet over the same route if the packet got here
228 * using IP source routing. This allows connection establishment and
229 * maintenance when the remote end is on a network that is not known
230 * to us.
231 */
232 int ip_nhops = 0;
233 static struct ip_srcrt {
234 struct in_addr dst; /* final destination */
235 char nop; /* one NOP to align */
236 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
237 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
238 } ip_srcrt;
239
240 static void save_rte __P((u_char *, struct in_addr));
241
242 /*
243 * IP initialization: fill in IP protocol switch table.
244 * All protocols not implemented in kernel go to raw IP protocol handler.
245 */
246 void
247 ip_init()
248 {
249 register struct protosw *pr;
250 register int i;
251
252 pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
253 0, NULL, NULL, M_IPQ);
254
255 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
256 if (pr == 0)
257 panic("ip_init");
258 for (i = 0; i < IPPROTO_MAX; i++)
259 ip_protox[i] = pr - inetsw;
260 for (pr = inetdomain.dom_protosw;
261 pr < inetdomain.dom_protoswNPROTOSW; pr++)
262 if (pr->pr_domain->dom_family == PF_INET &&
263 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
264 ip_protox[pr->pr_protocol] = pr - inetsw;
265 LIST_INIT(&ipq);
266 ip_id = time.tv_sec & 0xffff;
267 ipintrq.ifq_maxlen = ipqmaxlen;
268 TAILQ_INIT(&in_ifaddr);
269 in_ifaddrhashtbl =
270 hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash);
271 if (ip_mtudisc != 0)
272 ip_mtudisc_timeout_q =
273 rt_timer_queue_create(ip_mtudisc_timeout);
274 #ifdef GATEWAY
275 ipflow_init();
276 #endif
277 }
278
279 struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
280 struct route ipforward_rt;
281
282 /*
283 * Ip input routine. Checksum and byte swap header. If fragmented
284 * try to reassemble. Process options. Pass to next level.
285 */
286 void
287 ipintr()
288 {
289 register struct ip *ip = NULL;
290 register struct mbuf *m;
291 register struct ipq *fp;
292 register struct in_ifaddr *ia;
293 register struct ifaddr *ifa;
294 struct ipqent *ipqe;
295 int hlen = 0, mff, len, s;
296 #ifdef PFIL_HOOKS
297 struct packet_filter_hook *pfh;
298 struct mbuf *m0;
299 int rv;
300 #endif /* PFIL_HOOKS */
301
302 next:
303 /*
304 * Get next datagram off input queue and get IP header
305 * in first mbuf.
306 */
307 s = splimp();
308 IF_DEQUEUE(&ipintrq, m);
309 splx(s);
310 if (m == 0)
311 return;
312 #ifdef DIAGNOSTIC
313 if ((m->m_flags & M_PKTHDR) == 0)
314 panic("ipintr no HDR");
315 #endif
316 /*
317 * If no IP addresses have been set yet but the interfaces
318 * are receiving, can't do anything with incoming packets yet.
319 */
320 if (in_ifaddr.tqh_first == 0)
321 goto bad;
322 ipstat.ips_total++;
323 if (m->m_len < sizeof (struct ip) &&
324 (m = m_pullup(m, sizeof (struct ip))) == 0) {
325 ipstat.ips_toosmall++;
326 goto next;
327 }
328 ip = mtod(m, struct ip *);
329 if (ip->ip_v != IPVERSION) {
330 ipstat.ips_badvers++;
331 goto bad;
332 }
333 hlen = ip->ip_hl << 2;
334 if (hlen < sizeof(struct ip)) { /* minimum header length */
335 ipstat.ips_badhlen++;
336 goto bad;
337 }
338 if (hlen > m->m_len) {
339 if ((m = m_pullup(m, hlen)) == 0) {
340 ipstat.ips_badhlen++;
341 goto next;
342 }
343 ip = mtod(m, struct ip *);
344 }
345
346 /*
347 * RFC1122: packets with a multicast source address are
348 * not allowed.
349 */
350 if (IN_MULTICAST(ip->ip_src.s_addr)) {
351 /* XXX stat */
352 goto bad;
353 }
354
355 if (in_cksum(m, hlen) != 0) {
356 ipstat.ips_badsum++;
357 goto bad;
358 }
359
360 /*
361 * Convert fields to host representation.
362 */
363 NTOHS(ip->ip_len);
364 NTOHS(ip->ip_off);
365 len = ip->ip_len;
366
367 /*
368 * Check for additional length bogosity
369 */
370 if (len < hlen)
371 {
372 ipstat.ips_badlen++;
373 goto bad;
374 }
375
376 /*
377 * Check that the amount of data in the buffers
378 * is as at least much as the IP header would have us expect.
379 * Trim mbufs if longer than we expect.
380 * Drop packet if shorter than we expect.
381 */
382 if (m->m_pkthdr.len < len) {
383 ipstat.ips_tooshort++;
384 goto bad;
385 }
386 if (m->m_pkthdr.len > len) {
387 if (m->m_len == m->m_pkthdr.len) {
388 m->m_len = len;
389 m->m_pkthdr.len = len;
390 } else
391 m_adj(m, len - m->m_pkthdr.len);
392 }
393
394 /*
395 * Assume that we can create a fast-forward IP flow entry
396 * based on this packet.
397 */
398 m->m_flags |= M_CANFASTFWD;
399
400 #ifdef PFIL_HOOKS
401 /*
402 * Run through list of hooks for input packets. If there are any
403 * filters which require that additional packets in the flow are
404 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
405 * Note that filters must _never_ set this flag, as another filter
406 * in the list may have previously cleared it.
407 */
408 m0 = m;
409 for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
410 if (pfh->pfil_func) {
411 rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
412 if (rv)
413 goto next;
414 m = m0;
415 if (m == NULL)
416 goto next;
417 ip = mtod(m, struct ip *);
418 }
419 #endif /* PFIL_HOOKS */
420
421 /*
422 * Process options and, if not destined for us,
423 * ship it on. ip_dooptions returns 1 when an
424 * error was detected (causing an icmp message
425 * to be sent and the original packet to be freed).
426 */
427 ip_nhops = 0; /* for source routed packets */
428 if (hlen > sizeof (struct ip) && ip_dooptions(m))
429 goto next;
430
431 /*
432 * Check our list of addresses, to see if the packet is for us.
433 */
434 INADDR_TO_IA(ip->ip_dst, ia);
435 if (ia != NULL)
436 goto ours;
437 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
438 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
439 ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
440 if (ifa->ifa_addr->sa_family != AF_INET) continue;
441 ia = ifatoia(ifa);
442 if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
443 in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
444 /*
445 * Look for all-0's host part (old broadcast addr),
446 * either for subnet or net.
447 */
448 ip->ip_dst.s_addr == ia->ia_subnet ||
449 ip->ip_dst.s_addr == ia->ia_net)
450 goto ours;
451 /*
452 * An interface with IP address zero accepts
453 * all packets that arrive on that interface.
454 */
455 if (in_nullhost(ia->ia_addr.sin_addr))
456 goto ours;
457 }
458 }
459 if (IN_MULTICAST(ip->ip_dst.s_addr)) {
460 struct in_multi *inm;
461 #ifdef MROUTING
462 extern struct socket *ip_mrouter;
463
464 if (m->m_flags & M_EXT) {
465 if ((m = m_pullup(m, hlen)) == 0) {
466 ipstat.ips_toosmall++;
467 goto next;
468 }
469 ip = mtod(m, struct ip *);
470 }
471
472 if (ip_mrouter) {
473 /*
474 * If we are acting as a multicast router, all
475 * incoming multicast packets are passed to the
476 * kernel-level multicast forwarding function.
477 * The packet is returned (relatively) intact; if
478 * ip_mforward() returns a non-zero value, the packet
479 * must be discarded, else it may be accepted below.
480 *
481 * (The IP ident field is put in the same byte order
482 * as expected when ip_mforward() is called from
483 * ip_output().)
484 */
485 if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
486 ipstat.ips_cantforward++;
487 m_freem(m);
488 goto next;
489 }
490
491 /*
492 * The process-level routing demon needs to receive
493 * all multicast IGMP packets, whether or not this
494 * host belongs to their destination groups.
495 */
496 if (ip->ip_p == IPPROTO_IGMP)
497 goto ours;
498 ipstat.ips_forward++;
499 }
500 #endif
501 /*
502 * See if we belong to the destination multicast group on the
503 * arrival interface.
504 */
505 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
506 if (inm == NULL) {
507 ipstat.ips_cantforward++;
508 m_freem(m);
509 goto next;
510 }
511 goto ours;
512 }
513 if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
514 in_nullhost(ip->ip_dst))
515 goto ours;
516
517 /*
518 * Not for us; forward if possible and desirable.
519 */
520 if (ipforwarding == 0) {
521 ipstat.ips_cantforward++;
522 m_freem(m);
523 } else
524 ip_forward(m, 0);
525 goto next;
526
527 ours:
528 /*
529 * If offset or IP_MF are set, must reassemble.
530 * Otherwise, nothing need be done.
531 * (We could look in the reassembly queue to see
532 * if the packet was previously fragmented,
533 * but it's not worth the time; just let them time out.)
534 */
535 if (ip->ip_off & ~(IP_DF|IP_RF)) {
536 /*
537 * Look for queue of fragments
538 * of this datagram.
539 */
540 IPQ_LOCK();
541 for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
542 if (ip->ip_id == fp->ipq_id &&
543 in_hosteq(ip->ip_src, fp->ipq_src) &&
544 in_hosteq(ip->ip_dst, fp->ipq_dst) &&
545 ip->ip_p == fp->ipq_p)
546 goto found;
547 fp = 0;
548 found:
549
550 /*
551 * Adjust ip_len to not reflect header,
552 * set ipqe_mff if more fragments are expected,
553 * convert offset of this to bytes.
554 */
555 ip->ip_len -= hlen;
556 mff = (ip->ip_off & IP_MF) != 0;
557 if (mff) {
558 /*
559 * Make sure that fragments have a data length
560 * that's a non-zero multiple of 8 bytes.
561 */
562 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
563 ipstat.ips_badfrags++;
564 IPQ_UNLOCK();
565 goto bad;
566 }
567 }
568 ip->ip_off <<= 3;
569
570 /*
571 * If datagram marked as having more fragments
572 * or if this is not the first fragment,
573 * attempt reassembly; if it succeeds, proceed.
574 */
575 if (mff || ip->ip_off) {
576 ipstat.ips_fragments++;
577 ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
578 if (ipqe == NULL) {
579 ipstat.ips_rcvmemdrop++;
580 IPQ_UNLOCK();
581 goto bad;
582 }
583 ipqe->ipqe_mff = mff;
584 ipqe->ipqe_m = m;
585 ipqe->ipqe_ip = ip;
586 m = ip_reass(ipqe, fp);
587 if (m == 0) {
588 IPQ_UNLOCK();
589 goto next;
590 }
591 ipstat.ips_reassembled++;
592 ip = mtod(m, struct ip *);
593 hlen = ip->ip_hl << 2;
594 ip->ip_len += hlen;
595 } else
596 if (fp)
597 ip_freef(fp);
598 IPQ_UNLOCK();
599 }
600
601 /*
602 * Switch out to protocol's input routine.
603 */
604 #if IFA_STATS
605 ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
606 #endif
607 ipstat.ips_delivered++;
608 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
609 goto next;
610 bad:
611 m_freem(m);
612 goto next;
613 }
614
615 /*
616 * Take incoming datagram fragment and try to
617 * reassemble it into whole datagram. If a chain for
618 * reassembly of this datagram already exists, then it
619 * is given as fp; otherwise have to make a chain.
620 */
621 struct mbuf *
622 ip_reass(ipqe, fp)
623 register struct ipqent *ipqe;
624 register struct ipq *fp;
625 {
626 register struct mbuf *m = ipqe->ipqe_m;
627 register struct ipqent *nq, *p, *q;
628 struct ip *ip;
629 struct mbuf *t;
630 int hlen = ipqe->ipqe_ip->ip_hl << 2;
631 int i, next;
632
633 IPQ_LOCK_CHECK();
634
635 /*
636 * Presence of header sizes in mbufs
637 * would confuse code below.
638 */
639 m->m_data += hlen;
640 m->m_len -= hlen;
641
642 /*
643 * If first fragment to arrive, create a reassembly queue.
644 */
645 if (fp == 0) {
646 /*
647 * Enforce upper bound on number of fragmented packets
648 * for which we attempt reassembly;
649 * If maxfrag is 0, never accept fragments.
650 * If maxfrag is -1, accept all fragments without limitation.
651 */
652 if (ip_maxfragpackets < 0)
653 ;
654 else if (ip_nfragpackets >= ip_maxfragpackets)
655 goto dropfrag;
656 ip_nfragpackets++;
657 MALLOC(fp, struct ipq *, sizeof (struct ipq),
658 M_FTABLE, M_NOWAIT);
659 if (fp == NULL)
660 goto dropfrag;
661 LIST_INSERT_HEAD(&ipq, fp, ipq_q);
662 fp->ipq_ttl = IPFRAGTTL;
663 fp->ipq_p = ipqe->ipqe_ip->ip_p;
664 fp->ipq_id = ipqe->ipqe_ip->ip_id;
665 LIST_INIT(&fp->ipq_fragq);
666 fp->ipq_src = ipqe->ipqe_ip->ip_src;
667 fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
668 p = NULL;
669 goto insert;
670 }
671
672 /*
673 * Find a segment which begins after this one does.
674 */
675 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
676 p = q, q = q->ipqe_q.le_next)
677 if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
678 break;
679
680 /*
681 * If there is a preceding segment, it may provide some of
682 * our data already. If so, drop the data from the incoming
683 * segment. If it provides all of our data, drop us.
684 */
685 if (p != NULL) {
686 i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
687 ipqe->ipqe_ip->ip_off;
688 if (i > 0) {
689 if (i >= ipqe->ipqe_ip->ip_len)
690 goto dropfrag;
691 m_adj(ipqe->ipqe_m, i);
692 ipqe->ipqe_ip->ip_off += i;
693 ipqe->ipqe_ip->ip_len -= i;
694 }
695 }
696
697 /*
698 * While we overlap succeeding segments trim them or,
699 * if they are completely covered, dequeue them.
700 */
701 for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
702 q->ipqe_ip->ip_off; q = nq) {
703 i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
704 q->ipqe_ip->ip_off;
705 if (i < q->ipqe_ip->ip_len) {
706 q->ipqe_ip->ip_len -= i;
707 q->ipqe_ip->ip_off += i;
708 m_adj(q->ipqe_m, i);
709 break;
710 }
711 nq = q->ipqe_q.le_next;
712 m_freem(q->ipqe_m);
713 LIST_REMOVE(q, ipqe_q);
714 pool_put(&ipqent_pool, q);
715 }
716
717 insert:
718 /*
719 * Stick new segment in its place;
720 * check for complete reassembly.
721 */
722 if (p == NULL) {
723 LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
724 } else {
725 LIST_INSERT_AFTER(p, ipqe, ipqe_q);
726 }
727 next = 0;
728 for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
729 p = q, q = q->ipqe_q.le_next) {
730 if (q->ipqe_ip->ip_off != next)
731 return (0);
732 next += q->ipqe_ip->ip_len;
733 }
734 if (p->ipqe_mff)
735 return (0);
736
737 /*
738 * Reassembly is complete. Check for a bogus message size and
739 * concatenate fragments.
740 */
741 q = fp->ipq_fragq.lh_first;
742 ip = q->ipqe_ip;
743 if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
744 ipstat.ips_toolong++;
745 ip_freef(fp);
746 return (0);
747 }
748 m = q->ipqe_m;
749 t = m->m_next;
750 m->m_next = 0;
751 m_cat(m, t);
752 nq = q->ipqe_q.le_next;
753 pool_put(&ipqent_pool, q);
754 for (q = nq; q != NULL; q = nq) {
755 t = q->ipqe_m;
756 nq = q->ipqe_q.le_next;
757 pool_put(&ipqent_pool, q);
758 m_cat(m, t);
759 }
760
761 /*
762 * Create header for new ip packet by
763 * modifying header of first packet;
764 * dequeue and discard fragment reassembly header.
765 * Make header visible.
766 */
767 ip->ip_len = next;
768 ip->ip_src = fp->ipq_src;
769 ip->ip_dst = fp->ipq_dst;
770 LIST_REMOVE(fp, ipq_q);
771 FREE(fp, M_FTABLE);
772 ip_nfragpackets--;
773 m->m_len += (ip->ip_hl << 2);
774 m->m_data -= (ip->ip_hl << 2);
775 /* some debugging cruft by sklower, below, will go away soon */
776 if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
777 register int plen = 0;
778 for (t = m; t; t = t->m_next)
779 plen += t->m_len;
780 m->m_pkthdr.len = plen;
781 }
782 return (m);
783
784 dropfrag:
785 ipstat.ips_fragdropped++;
786 m_freem(m);
787 pool_put(&ipqent_pool, ipqe);
788 return (0);
789 }
790
791 /*
792 * Free a fragment reassembly header and all
793 * associated datagrams.
794 */
795 void
796 ip_freef(fp)
797 struct ipq *fp;
798 {
799 register struct ipqent *q, *p;
800
801 IPQ_LOCK_CHECK();
802
803 for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
804 p = q->ipqe_q.le_next;
805 m_freem(q->ipqe_m);
806 LIST_REMOVE(q, ipqe_q);
807 pool_put(&ipqent_pool, q);
808 }
809 LIST_REMOVE(fp, ipq_q);
810 FREE(fp, M_FTABLE);
811 ip_nfragpackets--;
812 }
813
814 /*
815 * IP timer processing;
816 * if a timer expires on a reassembly
817 * queue, discard it.
818 */
819 void
820 ip_slowtimo()
821 {
822 register struct ipq *fp, *nfp;
823 int s = splsoftnet();
824
825 IPQ_LOCK();
826 for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
827 nfp = fp->ipq_q.le_next;
828 if (--fp->ipq_ttl == 0) {
829 ipstat.ips_fragtimeout++;
830 ip_freef(fp);
831 }
832 }
833 /*
834 * If we are over the maximum number of fragments
835 * (due to the limit being lowered), drain off
836 * enough to get down to the new limit.
837 */
838 if (ip_maxfragpackets < 0)
839 ;
840 else {
841 while (ip_nfragpackets > ip_maxfragpackets && ipq.lh_first)
842 ip_freef(ipq.lh_first);
843 }
844 IPQ_UNLOCK();
845 #ifdef GATEWAY
846 ipflow_slowtimo();
847 #endif
848 splx(s);
849 }
850
851 /*
852 * Drain off all datagram fragments.
853 */
854 void
855 ip_drain()
856 {
857
858 /*
859 * We may be called from a device's interrupt context. If
860 * the ipq is already busy, just bail out now.
861 */
862 if (ipq_lock_try() == 0)
863 return;
864
865 while (ipq.lh_first != NULL) {
866 ipstat.ips_fragdropped++;
867 ip_freef(ipq.lh_first);
868 }
869
870 IPQ_UNLOCK();
871 }
872
873 /*
874 * Do option processing on a datagram,
875 * possibly discarding it if bad options are encountered,
876 * or forwarding it if source-routed.
877 * Returns 1 if packet has been forwarded/freed,
878 * 0 if the packet should be processed further.
879 */
880 int
881 ip_dooptions(m)
882 struct mbuf *m;
883 {
884 register struct ip *ip = mtod(m, struct ip *);
885 register u_char *cp, *cp0;
886 register struct ip_timestamp *ipt;
887 register struct in_ifaddr *ia;
888 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
889 struct in_addr dst;
890 n_time ntime;
891
892 dst = ip->ip_dst;
893 cp = (u_char *)(ip + 1);
894 cnt = (ip->ip_hl << 2) - sizeof (struct ip);
895 for (; cnt > 0; cnt -= optlen, cp += optlen) {
896 opt = cp[IPOPT_OPTVAL];
897 if (opt == IPOPT_EOL)
898 break;
899 if (opt == IPOPT_NOP)
900 optlen = 1;
901 else {
902 optlen = cp[IPOPT_OLEN];
903 if (optlen <= 0 || optlen > cnt) {
904 code = &cp[IPOPT_OLEN] - (u_char *)ip;
905 goto bad;
906 }
907 }
908 switch (opt) {
909
910 default:
911 break;
912
913 /*
914 * Source routing with record.
915 * Find interface with current destination address.
916 * If none on this machine then drop if strictly routed,
917 * or do nothing if loosely routed.
918 * Record interface address and bring up next address
919 * component. If strictly routed make sure next
920 * address is on directly accessible net.
921 */
922 case IPOPT_LSRR:
923 case IPOPT_SSRR:
924 if (ip_allowsrcrt == 0) {
925 type = ICMP_UNREACH;
926 code = ICMP_UNREACH_NET_PROHIB;
927 goto bad;
928 }
929 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
930 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
931 goto bad;
932 }
933 ipaddr.sin_addr = ip->ip_dst;
934 ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
935 if (ia == 0) {
936 if (opt == IPOPT_SSRR) {
937 type = ICMP_UNREACH;
938 code = ICMP_UNREACH_SRCFAIL;
939 goto bad;
940 }
941 /*
942 * Loose routing, and not at next destination
943 * yet; nothing to do except forward.
944 */
945 break;
946 }
947 off--; /* 0 origin */
948 if ((off + sizeof(struct in_addr)) > optlen) {
949 /*
950 * End of source route. Should be for us.
951 */
952 save_rte(cp, ip->ip_src);
953 break;
954 }
955 /*
956 * locate outgoing interface
957 */
958 bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
959 sizeof(ipaddr.sin_addr));
960 if (opt == IPOPT_SSRR) {
961 #define INA struct in_ifaddr *
962 #define SA struct sockaddr *
963 ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
964 } else
965 ia = ip_rtaddr(ipaddr.sin_addr);
966 if (ia == 0) {
967 type = ICMP_UNREACH;
968 code = ICMP_UNREACH_SRCFAIL;
969 goto bad;
970 }
971 ip->ip_dst = ipaddr.sin_addr;
972 bcopy((caddr_t)&ia->ia_addr.sin_addr,
973 (caddr_t)(cp + off), sizeof(struct in_addr));
974 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
975 /*
976 * Let ip_intr's mcast routing check handle mcast pkts
977 */
978 forward = !IN_MULTICAST(ip->ip_dst.s_addr);
979 break;
980
981 case IPOPT_RR:
982 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
983 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
984 goto bad;
985 }
986 /*
987 * If no space remains, ignore.
988 */
989 off--; /* 0 origin */
990 if ((off + sizeof(struct in_addr)) > optlen)
991 break;
992 bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
993 sizeof(ipaddr.sin_addr));
994 /*
995 * locate outgoing interface; if we're the destination,
996 * use the incoming interface (should be same).
997 */
998 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
999 (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1000 type = ICMP_UNREACH;
1001 code = ICMP_UNREACH_HOST;
1002 goto bad;
1003 }
1004 bcopy((caddr_t)&ia->ia_addr.sin_addr,
1005 (caddr_t)(cp + off), sizeof(struct in_addr));
1006 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1007 break;
1008
1009 case IPOPT_TS:
1010 code = cp - (u_char *)ip;
1011 ipt = (struct ip_timestamp *)cp;
1012 if (ipt->ipt_len < 5)
1013 goto bad;
1014 if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1015 if (++ipt->ipt_oflw == 0)
1016 goto bad;
1017 break;
1018 }
1019 cp0 = (cp + ipt->ipt_ptr - 1);
1020 switch (ipt->ipt_flg) {
1021
1022 case IPOPT_TS_TSONLY:
1023 break;
1024
1025 case IPOPT_TS_TSANDADDR:
1026 if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1027 sizeof(struct in_addr) > ipt->ipt_len)
1028 goto bad;
1029 ipaddr.sin_addr = dst;
1030 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1031 m->m_pkthdr.rcvif);
1032 if (ia == 0)
1033 continue;
1034 bcopy(&ia->ia_addr.sin_addr,
1035 cp0, sizeof(struct in_addr));
1036 ipt->ipt_ptr += sizeof(struct in_addr);
1037 break;
1038
1039 case IPOPT_TS_PRESPEC:
1040 if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1041 sizeof(struct in_addr) > ipt->ipt_len)
1042 goto bad;
1043 bcopy(cp0, &ipaddr.sin_addr,
1044 sizeof(struct in_addr));
1045 if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1046 continue;
1047 ipt->ipt_ptr += sizeof(struct in_addr);
1048 break;
1049
1050 default:
1051 goto bad;
1052 }
1053 ntime = iptime();
1054 cp0 = (u_char *) &ntime; /* XXX GCC BUG */
1055 bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1,
1056 sizeof(n_time));
1057 ipt->ipt_ptr += sizeof(n_time);
1058 }
1059 }
1060 if (forward) {
1061 if (ip_forwsrcrt == 0) {
1062 type = ICMP_UNREACH;
1063 code = ICMP_UNREACH_SRCFAIL;
1064 goto bad;
1065 }
1066 ip_forward(m, 1);
1067 return (1);
1068 }
1069 return (0);
1070 bad:
1071 icmp_error(m, type, code, 0, 0);
1072 ipstat.ips_badoptions++;
1073 return (1);
1074 }
1075
1076 /*
1077 * Given address of next destination (final or next hop),
1078 * return internet address info of interface to be used to get there.
1079 */
1080 struct in_ifaddr *
1081 ip_rtaddr(dst)
1082 struct in_addr dst;
1083 {
1084 register struct sockaddr_in *sin;
1085
1086 sin = satosin(&ipforward_rt.ro_dst);
1087
1088 if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1089 if (ipforward_rt.ro_rt) {
1090 RTFREE(ipforward_rt.ro_rt);
1091 ipforward_rt.ro_rt = 0;
1092 }
1093 sin->sin_family = AF_INET;
1094 sin->sin_len = sizeof(*sin);
1095 sin->sin_addr = dst;
1096
1097 rtalloc(&ipforward_rt);
1098 }
1099 if (ipforward_rt.ro_rt == 0)
1100 return ((struct in_ifaddr *)0);
1101 return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1102 }
1103
1104 /*
1105 * Save incoming source route for use in replies,
1106 * to be picked up later by ip_srcroute if the receiver is interested.
1107 */
1108 void
1109 save_rte(option, dst)
1110 u_char *option;
1111 struct in_addr dst;
1112 {
1113 unsigned olen;
1114
1115 olen = option[IPOPT_OLEN];
1116 #ifdef DIAGNOSTIC
1117 if (ipprintfs)
1118 printf("save_rte: olen %d\n", olen);
1119 #endif
1120 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1121 return;
1122 bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1123 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1124 ip_srcrt.dst = dst;
1125 }
1126
1127 /*
1128 * Retrieve incoming source route for use in replies,
1129 * in the same form used by setsockopt.
1130 * The first hop is placed before the options, will be removed later.
1131 */
1132 struct mbuf *
1133 ip_srcroute()
1134 {
1135 register struct in_addr *p, *q;
1136 register struct mbuf *m;
1137
1138 if (ip_nhops == 0)
1139 return ((struct mbuf *)0);
1140 m = m_get(M_DONTWAIT, MT_SOOPTS);
1141 if (m == 0)
1142 return ((struct mbuf *)0);
1143
1144 #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1145
1146 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1147 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1148 OPTSIZ;
1149 #ifdef DIAGNOSTIC
1150 if (ipprintfs)
1151 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1152 #endif
1153
1154 /*
1155 * First save first hop for return route
1156 */
1157 p = &ip_srcrt.route[ip_nhops - 1];
1158 *(mtod(m, struct in_addr *)) = *p--;
1159 #ifdef DIAGNOSTIC
1160 if (ipprintfs)
1161 printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1162 #endif
1163
1164 /*
1165 * Copy option fields and padding (nop) to mbuf.
1166 */
1167 ip_srcrt.nop = IPOPT_NOP;
1168 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1169 bcopy((caddr_t)&ip_srcrt.nop,
1170 mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1171 q = (struct in_addr *)(mtod(m, caddr_t) +
1172 sizeof(struct in_addr) + OPTSIZ);
1173 #undef OPTSIZ
1174 /*
1175 * Record return path as an IP source route,
1176 * reversing the path (pointers are now aligned).
1177 */
1178 while (p >= ip_srcrt.route) {
1179 #ifdef DIAGNOSTIC
1180 if (ipprintfs)
1181 printf(" %x", ntohl(q->s_addr));
1182 #endif
1183 *q++ = *p--;
1184 }
1185 /*
1186 * Last hop goes to final destination.
1187 */
1188 *q = ip_srcrt.dst;
1189 #ifdef DIAGNOSTIC
1190 if (ipprintfs)
1191 printf(" %x\n", ntohl(q->s_addr));
1192 #endif
1193 return (m);
1194 }
1195
1196 /*
1197 * Strip out IP options, at higher
1198 * level protocol in the kernel.
1199 * Second argument is buffer to which options
1200 * will be moved, and return value is their length.
1201 * XXX should be deleted; last arg currently ignored.
1202 */
1203 void
1204 ip_stripoptions(m, mopt)
1205 register struct mbuf *m;
1206 struct mbuf *mopt;
1207 {
1208 register int i;
1209 struct ip *ip = mtod(m, struct ip *);
1210 register caddr_t opts;
1211 int olen;
1212
1213 olen = (ip->ip_hl << 2) - sizeof (struct ip);
1214 opts = (caddr_t)(ip + 1);
1215 i = m->m_len - (sizeof (struct ip) + olen);
1216 bcopy(opts + olen, opts, (unsigned)i);
1217 m->m_len -= olen;
1218 if (m->m_flags & M_PKTHDR)
1219 m->m_pkthdr.len -= olen;
1220 ip->ip_len -= olen;
1221 ip->ip_hl = sizeof (struct ip) >> 2;
1222 }
1223
1224 int inetctlerrmap[PRC_NCMDS] = {
1225 0, 0, 0, 0,
1226 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1227 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1228 EMSGSIZE, EHOSTUNREACH, 0, 0,
1229 0, 0, 0, 0,
1230 ENOPROTOOPT
1231 };
1232
1233 /*
1234 * Forward a packet. If some error occurs return the sender
1235 * an icmp packet. Note we can't always generate a meaningful
1236 * icmp message because icmp doesn't have a large enough repertoire
1237 * of codes and types.
1238 *
1239 * If not forwarding, just drop the packet. This could be confusing
1240 * if ipforwarding was zero but some routing protocol was advancing
1241 * us as a gateway to somewhere. However, we must let the routing
1242 * protocol deal with that.
1243 *
1244 * The srcrt parameter indicates whether the packet is being forwarded
1245 * via a source route.
1246 */
1247 void
1248 ip_forward(m, srcrt)
1249 struct mbuf *m;
1250 int srcrt;
1251 {
1252 register struct ip *ip = mtod(m, struct ip *);
1253 register struct sockaddr_in *sin;
1254 register struct rtentry *rt;
1255 int error, type = 0, code = 0;
1256 struct mbuf *mcopy;
1257 n_long dest;
1258 struct ifnet *destifp;
1259
1260 dest = 0;
1261 #ifdef DIAGNOSTIC
1262 if (ipprintfs)
1263 printf("forward: src %2.2x dst %2.2x ttl %x\n",
1264 ntohl(ip->ip_src.s_addr),
1265 ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1266 #endif
1267 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1268 ipstat.ips_cantforward++;
1269 m_freem(m);
1270 return;
1271 }
1272 if (ip->ip_ttl <= IPTTLDEC) {
1273 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1274 return;
1275 }
1276 ip->ip_ttl -= IPTTLDEC;
1277
1278 sin = satosin(&ipforward_rt.ro_dst);
1279 if ((rt = ipforward_rt.ro_rt) == 0 ||
1280 !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1281 if (ipforward_rt.ro_rt) {
1282 RTFREE(ipforward_rt.ro_rt);
1283 ipforward_rt.ro_rt = 0;
1284 }
1285 sin->sin_family = AF_INET;
1286 sin->sin_len = sizeof(struct sockaddr_in);
1287 sin->sin_addr = ip->ip_dst;
1288
1289 rtalloc(&ipforward_rt);
1290 if (ipforward_rt.ro_rt == 0) {
1291 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1292 return;
1293 }
1294 rt = ipforward_rt.ro_rt;
1295 }
1296
1297 /*
1298 * Save at most 68 bytes of the packet in case
1299 * we need to generate an ICMP message to the src.
1300 */
1301 mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1302
1303 /*
1304 * If forwarding packet using same interface that it came in on,
1305 * perhaps should send a redirect to sender to shortcut a hop.
1306 * Only send redirect if source is sending directly to us,
1307 * and if packet was not source routed (or has any options).
1308 * Also, don't send redirect if forwarding using a default route
1309 * or a route modified by a redirect.
1310 */
1311 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1312 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1313 !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1314 ipsendredirects && !srcrt) {
1315 if (rt->rt_ifa &&
1316 (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1317 ifatoia(rt->rt_ifa)->ia_subnet) {
1318 if (rt->rt_flags & RTF_GATEWAY)
1319 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1320 else
1321 dest = ip->ip_dst.s_addr;
1322 /*
1323 * Router requirements says to only send host
1324 * redirects.
1325 */
1326 type = ICMP_REDIRECT;
1327 code = ICMP_REDIRECT_HOST;
1328 #ifdef DIAGNOSTIC
1329 if (ipprintfs)
1330 printf("redirect (%d) to %x\n", code,
1331 (u_int32_t)dest);
1332 #endif
1333 }
1334 }
1335
1336 error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1337 (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1338 if (error)
1339 ipstat.ips_cantforward++;
1340 else {
1341 ipstat.ips_forward++;
1342 if (type)
1343 ipstat.ips_redirectsent++;
1344 else {
1345 if (mcopy) {
1346 #ifdef GATEWAY
1347 if (mcopy->m_flags & M_CANFASTFWD)
1348 ipflow_create(&ipforward_rt, mcopy);
1349 #endif
1350 m_freem(mcopy);
1351 }
1352 return;
1353 }
1354 }
1355 if (mcopy == NULL)
1356 return;
1357 destifp = NULL;
1358
1359 switch (error) {
1360
1361 case 0: /* forwarded, but need redirect */
1362 /* type, code set above */
1363 break;
1364
1365 case ENETUNREACH: /* shouldn't happen, checked above */
1366 case EHOSTUNREACH:
1367 case ENETDOWN:
1368 case EHOSTDOWN:
1369 default:
1370 type = ICMP_UNREACH;
1371 code = ICMP_UNREACH_HOST;
1372 break;
1373
1374 case EMSGSIZE:
1375 type = ICMP_UNREACH;
1376 code = ICMP_UNREACH_NEEDFRAG;
1377 if (ipforward_rt.ro_rt)
1378 destifp = ipforward_rt.ro_rt->rt_ifp;
1379 ipstat.ips_cantfrag++;
1380 break;
1381
1382 case ENOBUFS:
1383 type = ICMP_SOURCEQUENCH;
1384 code = 0;
1385 break;
1386 }
1387 icmp_error(mcopy, type, code, dest, destifp);
1388 }
1389
1390 void
1391 ip_savecontrol(inp, mp, ip, m)
1392 register struct inpcb *inp;
1393 register struct mbuf **mp;
1394 register struct ip *ip;
1395 register struct mbuf *m;
1396 {
1397
1398 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1399 struct timeval tv;
1400
1401 microtime(&tv);
1402 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1403 SCM_TIMESTAMP, SOL_SOCKET);
1404 if (*mp)
1405 mp = &(*mp)->m_next;
1406 }
1407 if (inp->inp_flags & INP_RECVDSTADDR) {
1408 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1409 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1410 if (*mp)
1411 mp = &(*mp)->m_next;
1412 }
1413 #ifdef notyet
1414 /*
1415 * XXX
1416 * Moving these out of udp_input() made them even more broken
1417 * than they already were.
1418 * - fenner (at) parc.xerox.com
1419 */
1420 /* options were tossed already */
1421 if (inp->inp_flags & INP_RECVOPTS) {
1422 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1423 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1424 if (*mp)
1425 mp = &(*mp)->m_next;
1426 }
1427 /* ip_srcroute doesn't do what we want here, need to fix */
1428 if (inp->inp_flags & INP_RECVRETOPTS) {
1429 *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1430 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1431 if (*mp)
1432 mp = &(*mp)->m_next;
1433 }
1434 #endif
1435 if (inp->inp_flags & INP_RECVIF) {
1436 struct sockaddr_dl sdl;
1437
1438 sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1439 sdl.sdl_family = AF_LINK;
1440 sdl.sdl_index = m->m_pkthdr.rcvif ?
1441 m->m_pkthdr.rcvif->if_index : 0;
1442 sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1443 *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1444 IP_RECVIF, IPPROTO_IP);
1445 if (*mp)
1446 mp = &(*mp)->m_next;
1447 }
1448 }
1449
1450 int
1451 ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1452 int *name;
1453 u_int namelen;
1454 void *oldp;
1455 size_t *oldlenp;
1456 void *newp;
1457 size_t newlen;
1458 {
1459 extern int subnetsarelocal;
1460
1461 int error, old;
1462
1463 /* All sysctl names at this level are terminal. */
1464 if (namelen != 1)
1465 return (ENOTDIR);
1466
1467 switch (name[0]) {
1468 case IPCTL_FORWARDING:
1469 return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1470 case IPCTL_SENDREDIRECTS:
1471 return (sysctl_int(oldp, oldlenp, newp, newlen,
1472 &ipsendredirects));
1473 case IPCTL_DEFTTL:
1474 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1475 #ifdef notyet
1476 case IPCTL_DEFMTU:
1477 return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1478 #endif
1479 case IPCTL_FORWSRCRT:
1480 /* Don't allow this to change in a secure environment. */
1481 if (securelevel > 0)
1482 return (sysctl_rdint(oldp, oldlenp, newp,
1483 ip_forwsrcrt));
1484 else
1485 return (sysctl_int(oldp, oldlenp, newp, newlen,
1486 &ip_forwsrcrt));
1487 case IPCTL_DIRECTEDBCAST:
1488 return (sysctl_int(oldp, oldlenp, newp, newlen,
1489 &ip_directedbcast));
1490 case IPCTL_ALLOWSRCRT:
1491 return (sysctl_int(oldp, oldlenp, newp, newlen,
1492 &ip_allowsrcrt));
1493 case IPCTL_SUBNETSARELOCAL:
1494 return (sysctl_int(oldp, oldlenp, newp, newlen,
1495 &subnetsarelocal));
1496 case IPCTL_MTUDISC:
1497 error = sysctl_int(oldp, oldlenp, newp, newlen,
1498 &ip_mtudisc);
1499 if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1500 ip_mtudisc_timeout_q =
1501 rt_timer_queue_create(ip_mtudisc_timeout);
1502 } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1503 rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1504 ip_mtudisc_timeout_q = NULL;
1505 }
1506 return error;
1507 case IPCTL_ANONPORTMIN:
1508 old = anonportmin;
1509 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1510 if (anonportmin >= anonportmax || anonportmin > 65535
1511 #ifndef IPNOPRIVPORTS
1512 || anonportmin < IPPORT_RESERVED
1513 #endif
1514 ) {
1515 anonportmin = old;
1516 return (EINVAL);
1517 }
1518 return (error);
1519 case IPCTL_ANONPORTMAX:
1520 old = anonportmax;
1521 error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1522 if (anonportmin >= anonportmax || anonportmax > 65535
1523 #ifndef IPNOPRIVPORTS
1524 || anonportmax < IPPORT_RESERVED
1525 #endif
1526 ) {
1527 anonportmax = old;
1528 return (EINVAL);
1529 }
1530 return (error);
1531 case IPCTL_MTUDISCTIMEOUT:
1532 error = sysctl_int(oldp, oldlenp, newp, newlen,
1533 &ip_mtudisc_timeout);
1534 if (ip_mtudisc_timeout_q != NULL)
1535 rt_timer_queue_change(ip_mtudisc_timeout_q,
1536 ip_mtudisc_timeout);
1537 return (error);
1538 #ifdef GATEWAY
1539 case IPCTL_MAXFLOWS:
1540 {
1541 int s;
1542
1543 error = sysctl_int(oldp, oldlenp, newp, newlen,
1544 &ip_maxflows);
1545 s = splsoftnet();
1546 ipflow_reap(0);
1547 splx(s);
1548 return (error);
1549 }
1550 #endif
1551
1552 case IPCTL_MAXFRAGPACKETS:
1553 return (sysctl_int(oldp, oldlenp, newp, newlen,
1554 &ip_maxfragpackets));
1555
1556 default:
1557 return (EOPNOTSUPP);
1558 }
1559 /* NOTREACHED */
1560 }
1561