1 /*-
2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
30 * $FreeBSD: releng/5.4/sys/netinet/ip_input.c 145335 2005-04-20 19:11:07Z cvs2svn $
31 */
32
33 #include "opt_bootp.h"
34 #include "opt_ipfw.h"
35 #include "opt_ipstealth.h"
36 #include "opt_ipsec.h"
37 #include "opt_mac.h"
38 #include "opt_carp.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/callout.h>
43 #include <sys/mac.h>
44 #include <sys/mbuf.h>
45 #include <sys/malloc.h>
46 #include <sys/domain.h>
47 #include <sys/protosw.h>
48 #include <sys/socket.h>
49 #include <sys/time.h>
50 #include <sys/kernel.h>
51 #include <sys/syslog.h>
52 #include <sys/sysctl.h>
53
54 #include <net/pfil.h>
55 #include <net/if.h>
56 #include <net/if_types.h>
57 #include <net/if_var.h>
58 #include <net/if_dl.h>
59 #include <net/route.h>
60 #include <net/netisr.h>
61
62 #include <netinet/in.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/in_var.h>
65 #include <netinet/ip.h>
66 #include <netinet/in_pcb.h>
67 #include <netinet/ip_var.h>
68 #include <netinet/ip_icmp.h>
69 #include <machine/in_cksum.h>
70 #ifdef DEV_CARP
71 #include <netinet/ip_carp.h>
72 #endif
73
74 #include <sys/socketvar.h>
75
76 /* XXX: Temporary until ipfw_ether and ipfw_bridge are converted. */
77 #include <netinet/ip_fw.h>
78 #include <netinet/ip_dummynet.h>
79
80 #ifdef IPSEC
81 #include <netinet6/ipsec.h>
82 #include <netkey/key.h>
83 #endif
84
85 #ifdef FAST_IPSEC
86 #include <netipsec/ipsec.h>
87 #include <netipsec/key.h>
88 #endif
89
90 int rsvp_on = 0;
91
92 int ipforwarding = 0;
93 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
94 &ipforwarding, 0, "Enable IP forwarding between interfaces");
95
96 static int ipsendredirects = 1; /* XXX */
97 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
98 &ipsendredirects, 0, "Enable sending IP redirects");
99
100 int ip_defttl = IPDEFTTL;
101 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
102 &ip_defttl, 0, "Maximum TTL on IP packets");
103
104 static int ip_dosourceroute = 0;
105 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
106 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
107
108 static int ip_acceptsourceroute = 0;
109 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
110 CTLFLAG_RW, &ip_acceptsourceroute, 0,
111 "Enable accepting source routed IP packets");
112
113 int ip_doopts = 1; /* 0 = ignore, 1 = process, 2 = reject */
114 SYSCTL_INT(_net_inet_ip, OID_AUTO, process_options, CTLFLAG_RW,
115 &ip_doopts, 0, "Enable IP options processing ([LS]SRR, RR, TS)");
116
117 static int ip_keepfaith = 0;
118 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
119 &ip_keepfaith, 0,
120 "Enable packet capture for FAITH IPv4->IPv6 translater daemon");
121
122 static int nipq = 0; /* total # of reass queues */
123 static int maxnipq;
124 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
125 &maxnipq, 0,
126 "Maximum number of IPv4 fragment reassembly queue entries");
127
128 static int maxfragsperpacket;
129 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
130 &maxfragsperpacket, 0,
131 "Maximum number of IPv4 fragments allowed per packet");
132
133 static int ip_sendsourcequench = 0;
134 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
135 &ip_sendsourcequench, 0,
136 "Enable the transmission of source quench packets");
137
138 int ip_do_randomid = 0;
139 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
140 &ip_do_randomid, 0,
141 "Assign random ip_id values");
142
143 /*
144 * XXX - Setting ip_checkinterface mostly implements the receive side of
145 * the Strong ES model described in RFC 1122, but since the routing table
146 * and transmit implementation do not implement the Strong ES model,
147 * setting this to 1 results in an odd hybrid.
148 *
149 * XXX - ip_checkinterface currently must be disabled if you use ipnat
150 * to translate the destination address to another local interface.
151 *
152 * XXX - ip_checkinterface must be disabled if you add IP aliases
153 * to the loopback interface instead of the interface where the
154 * packets for those addresses are received.
155 */
156 static int ip_checkinterface = 0;
157 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
158 &ip_checkinterface, 0, "Verify packet arrives on correct interface");
159
160 #ifdef DIAGNOSTIC
161 static int ipprintfs = 0;
162 #endif
163
164 struct pfil_head inet_pfil_hook;
165
166 static struct ifqueue ipintrq;
167 static int ipqmaxlen = IFQ_MAXLEN;
168
169 extern struct domain inetdomain;
170 extern struct protosw inetsw[];
171 u_char ip_protox[IPPROTO_MAX];
172 struct in_ifaddrhead in_ifaddrhead; /* first inet address */
173 struct in_ifaddrhashhead *in_ifaddrhashtbl; /* inet addr hash table */
174 u_long in_ifaddrhmask; /* mask for hash table */
175
176 SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RW,
177 &ipintrq.ifq_maxlen, 0, "Maximum size of the IP input queue");
178 SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
179 &ipintrq.ifq_drops, 0, "Number of packets dropped from the IP input queue");
180
181 struct ipstat ipstat;
182 SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
183 &ipstat, ipstat, "IP statistics (struct ipstat, netinet/ip_var.h)");
184
185 /* Packet reassembly stuff */
186 #define IPREASS_NHASH_LOG2 6
187 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
188 #define IPREASS_HMASK (IPREASS_NHASH - 1)
189 #define IPREASS_HASH(x,y) \
190 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
191
192 static TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH];
193 struct mtx ipqlock;
194 struct callout ipport_tick_callout;
195
196 #define IPQ_LOCK() mtx_lock(&ipqlock)
197 #define IPQ_UNLOCK() mtx_unlock(&ipqlock)
198 #define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF)
199 #define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED)
200
201 #ifdef IPCTL_DEFMTU
202 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
203 &ip_mtu, 0, "Default MTU");
204 #endif
205
206 #ifdef IPSTEALTH
207 int ipstealth = 0;
208 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW,
209 &ipstealth, 0, "");
210 #endif
211
212 /*
213 * ipfw_ether and ipfw_bridge hooks.
214 * XXX: Temporary until those are converted to pfil_hooks as well.
215 */
216 ip_fw_chk_t *ip_fw_chk_ptr = NULL;
217 ip_dn_io_t *ip_dn_io_ptr = NULL;
218 int fw_enable = 1;
219 int fw_one_pass = 1;
220
221 /*
222 * XXX this is ugly. IP options source routing magic.
223 */
224 struct ipoptrt {
225 struct in_addr dst; /* final destination */
226 char nop; /* one NOP to align */
227 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
228 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
229 };
230
231 struct ipopt_tag {
232 struct m_tag tag;
233 int ip_nhops;
234 struct ipoptrt ip_srcrt;
235 };
236
237 static void save_rte(struct mbuf *, u_char *, struct in_addr);
238 static int ip_dooptions(struct mbuf *m, int);
239 static void ip_forward(struct mbuf *m, int srcrt);
240 static void ip_freef(struct ipqhead *, struct ipq *);
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 TAILQ_INIT(&in_ifaddrhead);
253 in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
254 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
255 if (pr == NULL)
256 panic("ip_init: PF_INET not found");
257
258 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
259 for (i = 0; i < IPPROTO_MAX; i++)
260 ip_protox[i] = pr - inetsw;
261 /*
262 * Cycle through IP protocols and put them into the appropriate place
263 * in ip_protox[].
264 */
265 for (pr = inetdomain.dom_protosw;
266 pr < inetdomain.dom_protoswNPROTOSW; pr++)
267 if (pr->pr_domain->dom_family == PF_INET &&
268 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
269 /* Be careful to only index valid IP protocols. */
270 if (pr->pr_protocol && pr->pr_protocol < IPPROTO_MAX)
271 ip_protox[pr->pr_protocol] = pr - inetsw;
272 }
273
274 /* Initialize packet filter hooks. */
275 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
276 inet_pfil_hook.ph_af = AF_INET;
277 if ((i = pfil_head_register(&inet_pfil_hook)) != 0)
278 printf("%s: WARNING: unable to register pfil hook, "
279 "error %d\n", __func__, i);
280
281 /* Initialize IP reassembly queue. */
282 IPQ_LOCK_INIT();
283 for (i = 0; i < IPREASS_NHASH; i++)
284 TAILQ_INIT(&ipq[i]);
285 maxnipq = nmbclusters / 32;
286 maxfragsperpacket = 16;
287
288 /* Start ipport_tick. */
289 callout_init(&ipport_tick_callout, CALLOUT_MPSAFE);
290 ipport_tick(NULL);
291 EVENTHANDLER_REGISTER(shutdown_pre_sync, ip_fini, NULL,
292 SHUTDOWN_PRI_DEFAULT);
293
294 /* Initialize various other remaining things. */
295 ip_id = time_second & 0xffff;
296 ipintrq.ifq_maxlen = ipqmaxlen;
297 mtx_init(&ipintrq.ifq_mtx, "ip_inq", NULL, MTX_DEF);
298 netisr_register(NETISR_IP, ip_input, &ipintrq, NETISR_MPSAFE);
299 }
300
301 void ip_fini(xtp)
302 void *xtp;
303 {
304 callout_stop(&ipport_tick_callout);
305 }
306
307 /*
308 * Ip input routine. Checksum and byte swap header. If fragmented
309 * try to reassemble. Process options. Pass to next level.
310 */
311 void
312 ip_input(struct mbuf *m)
313 {
314 struct ip *ip = NULL;
315 struct in_ifaddr *ia = NULL;
316 struct ifaddr *ifa;
317 int checkif, hlen = 0;
318 u_short sum;
319 int dchg = 0; /* dest changed after fw */
320 struct in_addr odst; /* original dst address */
321 #ifdef FAST_IPSEC
322 struct m_tag *mtag;
323 struct tdb_ident *tdbi;
324 struct secpolicy *sp;
325 int s, error;
326 #endif /* FAST_IPSEC */
327
328 M_ASSERTPKTHDR(m);
329
330 if (m->m_flags & M_FASTFWD_OURS) {
331 /*
332 * Firewall or NAT changed destination to local.
333 * We expect ip_len and ip_off to be in host byte order.
334 */
335 m->m_flags &= ~M_FASTFWD_OURS;
336 /* Set up some basics that will be used later. */
337 ip = mtod(m, struct ip *);
338 hlen = ip->ip_hl << 2;
339 goto ours;
340 }
341
342 ipstat.ips_total++;
343
344 if (m->m_pkthdr.len < sizeof(struct ip))
345 goto tooshort;
346
347 if (m->m_len < sizeof (struct ip) &&
348 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
349 ipstat.ips_toosmall++;
350 return;
351 }
352 ip = mtod(m, struct ip *);
353
354 if (ip->ip_v != IPVERSION) {
355 ipstat.ips_badvers++;
356 goto bad;
357 }
358
359 hlen = ip->ip_hl << 2;
360 if (hlen < sizeof(struct ip)) { /* minimum header length */
361 ipstat.ips_badhlen++;
362 goto bad;
363 }
364 if (hlen > m->m_len) {
365 if ((m = m_pullup(m, hlen)) == NULL) {
366 ipstat.ips_badhlen++;
367 return;
368 }
369 ip = mtod(m, struct ip *);
370 }
371
372 /* 127/8 must not appear on wire - RFC1122 */
373 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
374 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
375 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
376 ipstat.ips_badaddr++;
377 goto bad;
378 }
379 }
380
381 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
382 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
383 } else {
384 if (hlen == sizeof(struct ip)) {
385 sum = in_cksum_hdr(ip);
386 } else {
387 sum = in_cksum(m, hlen);
388 }
389 }
390 if (sum) {
391 ipstat.ips_badsum++;
392 goto bad;
393 }
394
395 #ifdef ALTQ
396 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
397 /* packet is dropped by traffic conditioner */
398 return;
399 #endif
400
401 /*
402 * Convert fields to host representation.
403 */
404 ip->ip_len = ntohs(ip->ip_len);
405 if (ip->ip_len < hlen) {
406 ipstat.ips_badlen++;
407 goto bad;
408 }
409 ip->ip_off = ntohs(ip->ip_off);
410
411 /*
412 * Check that the amount of data in the buffers
413 * is as at least much as the IP header would have us expect.
414 * Trim mbufs if longer than we expect.
415 * Drop packet if shorter than we expect.
416 */
417 if (m->m_pkthdr.len < ip->ip_len) {
418 tooshort:
419 ipstat.ips_tooshort++;
420 goto bad;
421 }
422 if (m->m_pkthdr.len > ip->ip_len) {
423 if (m->m_len == m->m_pkthdr.len) {
424 m->m_len = ip->ip_len;
425 m->m_pkthdr.len = ip->ip_len;
426 } else
427 m_adj(m, ip->ip_len - m->m_pkthdr.len);
428 }
429 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
430 /*
431 * Bypass packet filtering for packets from a tunnel (gif).
432 */
433 if (ipsec_getnhist(m))
434 goto passin;
435 #endif
436 #if defined(FAST_IPSEC) && !defined(IPSEC_FILTERGIF)
437 /*
438 * Bypass packet filtering for packets from a tunnel (gif).
439 */
440 if (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
441 goto passin;
442 #endif
443
444 /*
445 * Run through list of hooks for input packets.
446 *
447 * NB: Beware of the destination address changing (e.g.
448 * by NAT rewriting). When this happens, tell
449 * ip_forward to do the right thing.
450 */
451
452 /* Jump over all PFIL processing if hooks are not active. */
453 if (inet_pfil_hook.ph_busy_count == -1)
454 goto passin;
455
456 odst = ip->ip_dst;
457 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
458 PFIL_IN, NULL) != 0)
459 return;
460 if (m == NULL) /* consumed by filter */
461 return;
462
463 ip = mtod(m, struct ip *);
464 dchg = (odst.s_addr != ip->ip_dst.s_addr);
465
466 #ifdef IPFIREWALL_FORWARD
467 if (m->m_flags & M_FASTFWD_OURS) {
468 m->m_flags &= ~M_FASTFWD_OURS;
469 goto ours;
470 }
471 #ifndef IPFIREWALL_FORWARD_EXTENDED
472 dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL);
473 #else
474 if ((dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL)) != 0) {
475 /*
476 * Directly ship on the packet. This allows to forward packets
477 * that were destined for us to some other directly connected
478 * host.
479 */
480 ip_forward(m, dchg);
481 return;
482 }
483 #endif /* IPFIREWALL_FORWARD_EXTENDED */
484 #endif /* IPFIREWALL_FORWARD */
485
486 passin:
487 /*
488 * Process options and, if not destined for us,
489 * ship it on. ip_dooptions returns 1 when an
490 * error was detected (causing an icmp message
491 * to be sent and the original packet to be freed).
492 */
493 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
494 return;
495
496 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
497 * matter if it is destined to another node, or whether it is
498 * a multicast one, RSVP wants it! and prevents it from being forwarded
499 * anywhere else. Also checks if the rsvp daemon is running before
500 * grabbing the packet.
501 */
502 if (rsvp_on && ip->ip_p==IPPROTO_RSVP)
503 goto ours;
504
505 /*
506 * Check our list of addresses, to see if the packet is for us.
507 * If we don't have any addresses, assume any unicast packet
508 * we receive might be for us (and let the upper layers deal
509 * with it).
510 */
511 if (TAILQ_EMPTY(&in_ifaddrhead) &&
512 (m->m_flags & (M_MCAST|M_BCAST)) == 0)
513 goto ours;
514
515 /*
516 * Enable a consistency check between the destination address
517 * and the arrival interface for a unicast packet (the RFC 1122
518 * strong ES model) if IP forwarding is disabled and the packet
519 * is not locally generated and the packet is not subject to
520 * 'ipfw fwd'.
521 *
522 * XXX - Checking also should be disabled if the destination
523 * address is ipnat'ed to a different interface.
524 *
525 * XXX - Checking is incompatible with IP aliases added
526 * to the loopback interface instead of the interface where
527 * the packets are received.
528 *
529 * XXX - This is the case for carp vhost IPs as well so we
530 * insert a workaround. If the packet got here, we already
531 * checked with carp_iamatch() and carp_forus().
532 */
533 checkif = ip_checkinterface && (ipforwarding == 0) &&
534 m->m_pkthdr.rcvif != NULL &&
535 ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) &&
536 #ifdef DEV_CARP
537 !m->m_pkthdr.rcvif->if_carp &&
538 #endif
539 (dchg == 0);
540
541 /*
542 * Check for exact addresses in the hash bucket.
543 */
544 LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
545 /*
546 * If the address matches, verify that the packet
547 * arrived via the correct interface if checking is
548 * enabled.
549 */
550 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
551 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
552 goto ours;
553 }
554 /*
555 * Check for broadcast addresses.
556 *
557 * Only accept broadcast packets that arrive via the matching
558 * interface. Reception of forwarded directed broadcasts would
559 * be handled via ip_forward() and ether_output() with the loopback
560 * into the stack for SIMPLEX interfaces handled by ether_output().
561 */
562 if (m->m_pkthdr.rcvif != NULL &&
563 m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
564 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
565 if (ifa->ifa_addr->sa_family != AF_INET)
566 continue;
567 ia = ifatoia(ifa);
568 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
569 ip->ip_dst.s_addr)
570 goto ours;
571 if (ia->ia_netbroadcast.s_addr == ip->ip_dst.s_addr)
572 goto ours;
573 #ifdef BOOTP_COMPAT
574 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
575 goto ours;
576 #endif
577 }
578 }
579 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
580 struct in_multi *inm;
581 if (ip_mrouter) {
582 /*
583 * If we are acting as a multicast router, all
584 * incoming multicast packets are passed to the
585 * kernel-level multicast forwarding function.
586 * The packet is returned (relatively) intact; if
587 * ip_mforward() returns a non-zero value, the packet
588 * must be discarded, else it may be accepted below.
589 */
590 if (ip_mforward &&
591 ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
592 ipstat.ips_cantforward++;
593 m_freem(m);
594 return;
595 }
596
597 /*
598 * The process-level routing daemon needs to receive
599 * all multicast IGMP packets, whether or not this
600 * host belongs to their destination groups.
601 */
602 if (ip->ip_p == IPPROTO_IGMP)
603 goto ours;
604 ipstat.ips_forward++;
605 }
606 /*
607 * See if we belong to the destination multicast group on the
608 * arrival interface.
609 */
610 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
611 if (inm == NULL) {
612 ipstat.ips_notmember++;
613 m_freem(m);
614 return;
615 }
616 goto ours;
617 }
618 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
619 goto ours;
620 if (ip->ip_dst.s_addr == INADDR_ANY)
621 goto ours;
622
623 /*
624 * FAITH(Firewall Aided Internet Translator)
625 */
626 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
627 if (ip_keepfaith) {
628 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
629 goto ours;
630 }
631 m_freem(m);
632 return;
633 }
634
635 /*
636 * Not for us; forward if possible and desirable.
637 */
638 if (ipforwarding == 0) {
639 ipstat.ips_cantforward++;
640 m_freem(m);
641 } else {
642 #ifdef IPSEC
643 /*
644 * Enforce inbound IPsec SPD.
645 */
646 if (ipsec4_in_reject(m, NULL)) {
647 ipsecstat.in_polvio++;
648 goto bad;
649 }
650 #endif /* IPSEC */
651 #ifdef FAST_IPSEC
652 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
653 s = splnet();
654 if (mtag != NULL) {
655 tdbi = (struct tdb_ident *)(mtag + 1);
656 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
657 } else {
658 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
659 IP_FORWARDING, &error);
660 }
661 if (sp == NULL) { /* NB: can happen if error */
662 splx(s);
663 /*XXX error stat???*/
664 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
665 goto bad;
666 }
667
668 /*
669 * Check security policy against packet attributes.
670 */
671 error = ipsec_in_reject(sp, m);
672 KEY_FREESP(&sp);
673 splx(s);
674 if (error) {
675 ipstat.ips_cantforward++;
676 goto bad;
677 }
678 #endif /* FAST_IPSEC */
679 ip_forward(m, dchg);
680 }
681 return;
682
683 ours:
684 #ifdef IPSTEALTH
685 /*
686 * IPSTEALTH: Process non-routing options only
687 * if the packet is destined for us.
688 */
689 if (ipstealth && hlen > sizeof (struct ip) &&
690 ip_dooptions(m, 1))
691 return;
692 #endif /* IPSTEALTH */
693
694 /* Count the packet in the ip address stats */
695 if (ia != NULL) {
696 ia->ia_ifa.if_ipackets++;
697 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
698 }
699
700 /*
701 * Attempt reassembly; if it succeeds, proceed.
702 * ip_reass() will return a different mbuf.
703 */
704 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
705 m = ip_reass(m);
706 if (m == NULL)
707 return;
708 ip = mtod(m, struct ip *);
709 /* Get the header length of the reassembled packet */
710 hlen = ip->ip_hl << 2;
711 }
712
713 /*
714 * Further protocols expect the packet length to be w/o the
715 * IP header.
716 */
717 ip->ip_len -= hlen;
718
719 #ifdef IPSEC
720 /*
721 * enforce IPsec policy checking if we are seeing last header.
722 * note that we do not visit this with protocols with pcb layer
723 * code - like udp/tcp/raw ip.
724 */
725 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
726 ipsec4_in_reject(m, NULL)) {
727 ipsecstat.in_polvio++;
728 goto bad;
729 }
730 #endif
731 #if FAST_IPSEC
732 /*
733 * enforce IPsec policy checking if we are seeing last header.
734 * note that we do not visit this with protocols with pcb layer
735 * code - like udp/tcp/raw ip.
736 */
737 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
738 /*
739 * Check if the packet has already had IPsec processing
740 * done. If so, then just pass it along. This tag gets
741 * set during AH, ESP, etc. input handling, before the
742 * packet is returned to the ip input queue for delivery.
743 */
744 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
745 s = splnet();
746 if (mtag != NULL) {
747 tdbi = (struct tdb_ident *)(mtag + 1);
748 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
749 } else {
750 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
751 IP_FORWARDING, &error);
752 }
753 if (sp != NULL) {
754 /*
755 * Check security policy against packet attributes.
756 */
757 error = ipsec_in_reject(sp, m);
758 KEY_FREESP(&sp);
759 } else {
760 /* XXX error stat??? */
761 error = EINVAL;
762 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
763 goto bad;
764 }
765 splx(s);
766 if (error)
767 goto bad;
768 }
769 #endif /* FAST_IPSEC */
770
771 /*
772 * Switch out to protocol's input routine.
773 */
774 ipstat.ips_delivered++;
775
776 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
777 return;
778 bad:
779 m_freem(m);
780 }
781
782 /*
783 * Take incoming datagram fragment and try to reassemble it into
784 * whole datagram. If the argument is the first fragment or one
785 * in between the function will return NULL and store the mbuf
786 * in the fragment chain. If the argument is the last fragment
787 * the packet will be reassembled and the pointer to the new
788 * mbuf returned for further processing. Only m_tags attached
789 * to the first packet/fragment are preserved.
790 * The IP header is *NOT* adjusted out of iplen.
791 */
792
793 struct mbuf *
794 ip_reass(struct mbuf *m)
795 {
796 struct ip *ip;
797 struct mbuf *p, *q, *nq, *t;
798 struct ipq *fp = NULL;
799 struct ipqhead *head;
800 int i, hlen, next;
801 u_int8_t ecn, ecn0;
802 u_short hash;
803
804 /* If maxnipq is 0, never accept fragments. */
805 if (maxnipq == 0) {
806 ipstat.ips_fragments++;
807 ipstat.ips_fragdropped++;
808 m_freem(m);
809 return (NULL);
810 }
811
812 ip = mtod(m, struct ip *);
813 hlen = ip->ip_hl << 2;
814
815 hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
816 head = &ipq[hash];
817 IPQ_LOCK();
818
819 /*
820 * Look for queue of fragments
821 * of this datagram.
822 */
823 TAILQ_FOREACH(fp, head, ipq_list)
824 if (ip->ip_id == fp->ipq_id &&
825 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
826 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
827 #ifdef MAC
828 mac_fragment_match(m, fp) &&
829 #endif
830 ip->ip_p == fp->ipq_p)
831 goto found;
832
833 fp = NULL;
834
835 /*
836 * Enforce upper bound on number of fragmented packets
837 * for which we attempt reassembly;
838 * If maxnipq is -1, accept all fragments without limitation.
839 */
840 if ((nipq > maxnipq) && (maxnipq > 0)) {
841 /*
842 * drop something from the tail of the current queue
843 * before proceeding further
844 */
845 struct ipq *q = TAILQ_LAST(head, ipqhead);
846 if (q == NULL) { /* gak */
847 for (i = 0; i < IPREASS_NHASH; i++) {
848 struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead);
849 if (r) {
850 ipstat.ips_fragtimeout += r->ipq_nfrags;
851 ip_freef(&ipq[i], r);
852 break;
853 }
854 }
855 } else {
856 ipstat.ips_fragtimeout += q->ipq_nfrags;
857 ip_freef(head, q);
858 }
859 }
860
861 found:
862 /*
863 * Adjust ip_len to not reflect header,
864 * convert offset of this to bytes.
865 */
866 ip->ip_len -= hlen;
867 if (ip->ip_off & IP_MF) {
868 /*
869 * Make sure that fragments have a data length
870 * that's a non-zero multiple of 8 bytes.
871 */
872 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
873 ipstat.ips_toosmall++; /* XXX */
874 goto dropfrag;
875 }
876 m->m_flags |= M_FRAG;
877 } else
878 m->m_flags &= ~M_FRAG;
879 ip->ip_off <<= 3;
880
881
882 /*
883 * Attempt reassembly; if it succeeds, proceed.
884 * ip_reass() will return a different mbuf.
885 */
886 ipstat.ips_fragments++;
887 m->m_pkthdr.header = ip;
888
889 /* Previous ip_reass() started here. */
890 /*
891 * Presence of header sizes in mbufs
892 * would confuse code below.
893 */
894 m->m_data += hlen;
895 m->m_len -= hlen;
896
897 /*
898 * If first fragment to arrive, create a reassembly queue.
899 */
900 if (fp == NULL) {
901 if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
902 goto dropfrag;
903 fp = mtod(t, struct ipq *);
904 #ifdef MAC
905 if (mac_init_ipq(fp, M_NOWAIT) != 0) {
906 m_free(t);
907 goto dropfrag;
908 }
909 mac_create_ipq(m, fp);
910 #endif
911 TAILQ_INSERT_HEAD(head, fp, ipq_list);
912 nipq++;
913 fp->ipq_nfrags = 1;
914 fp->ipq_ttl = IPFRAGTTL;
915 fp->ipq_p = ip->ip_p;
916 fp->ipq_id = ip->ip_id;
917 fp->ipq_src = ip->ip_src;
918 fp->ipq_dst = ip->ip_dst;
919 fp->ipq_frags = m;
920 m->m_nextpkt = NULL;
921 goto inserted;
922 } else {
923 fp->ipq_nfrags++;
924 #ifdef MAC
925 mac_update_ipq(m, fp);
926 #endif
927 }
928
929 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
930
931 /*
932 * Handle ECN by comparing this segment with the first one;
933 * if CE is set, do not lose CE.
934 * drop if CE and not-ECT are mixed for the same packet.
935 */
936 ecn = ip->ip_tos & IPTOS_ECN_MASK;
937 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK;
938 if (ecn == IPTOS_ECN_CE) {
939 if (ecn0 == IPTOS_ECN_NOTECT)
940 goto dropfrag;
941 if (ecn0 != IPTOS_ECN_CE)
942 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE;
943 }
944 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
945 goto dropfrag;
946
947 /*
948 * Find a segment which begins after this one does.
949 */
950 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
951 if (GETIP(q)->ip_off > 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, otherwise
958 * stick new segment in the proper place.
959 *
960 * If some of the data is dropped from the the preceding
961 * segment, then it's checksum is invalidated.
962 */
963 if (p) {
964 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
965 if (i > 0) {
966 if (i >= ip->ip_len)
967 goto dropfrag;
968 m_adj(m, i);
969 m->m_pkthdr.csum_flags = 0;
970 ip->ip_off += i;
971 ip->ip_len -= i;
972 }
973 m->m_nextpkt = p->m_nextpkt;
974 p->m_nextpkt = m;
975 } else {
976 m->m_nextpkt = fp->ipq_frags;
977 fp->ipq_frags = m;
978 }
979
980 /*
981 * While we overlap succeeding segments trim them or,
982 * if they are completely covered, dequeue them.
983 */
984 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
985 q = nq) {
986 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
987 if (i < GETIP(q)->ip_len) {
988 GETIP(q)->ip_len -= i;
989 GETIP(q)->ip_off += i;
990 m_adj(q, i);
991 q->m_pkthdr.csum_flags = 0;
992 break;
993 }
994 nq = q->m_nextpkt;
995 m->m_nextpkt = nq;
996 ipstat.ips_fragdropped++;
997 fp->ipq_nfrags--;
998 m_freem(q);
999 }
1000
1001 inserted:
1002
1003 /*
1004 * Check for complete reassembly and perform frag per packet
1005 * limiting.
1006 *
1007 * Frag limiting is performed here so that the nth frag has
1008 * a chance to complete the packet before we drop the packet.
1009 * As a result, n+1 frags are actually allowed per packet, but
1010 * only n will ever be stored. (n = maxfragsperpacket.)
1011 *
1012 */
1013 next = 0;
1014 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1015 if (GETIP(q)->ip_off != next) {
1016 if (fp->ipq_nfrags > maxfragsperpacket) {
1017 ipstat.ips_fragdropped += fp->ipq_nfrags;
1018 ip_freef(head, fp);
1019 }
1020 goto done;
1021 }
1022 next += GETIP(q)->ip_len;
1023 }
1024 /* Make sure the last packet didn't have the IP_MF flag */
1025 if (p->m_flags & M_FRAG) {
1026 if (fp->ipq_nfrags > maxfragsperpacket) {
1027 ipstat.ips_fragdropped += fp->ipq_nfrags;
1028 ip_freef(head, fp);
1029 }
1030 goto done;
1031 }
1032
1033 /*
1034 * Reassembly is complete. Make sure the packet is a sane size.
1035 */
1036 q = fp->ipq_frags;
1037 ip = GETIP(q);
1038 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) {
1039 ipstat.ips_toolong++;
1040 ipstat.ips_fragdropped += fp->ipq_nfrags;
1041 ip_freef(head, fp);
1042 goto done;
1043 }
1044
1045 /*
1046 * Concatenate fragments.
1047 */
1048 m = q;
1049 t = m->m_next;
1050 m->m_next = NULL;
1051 m_cat(m, t);
1052 nq = q->m_nextpkt;
1053 q->m_nextpkt = NULL;
1054 for (q = nq; q != NULL; q = nq) {
1055 nq = q->m_nextpkt;
1056 q->m_nextpkt = NULL;
1057 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1058 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1059 m_cat(m, q);
1060 }
1061 #ifdef MAC
1062 mac_create_datagram_from_ipq(fp, m);
1063 mac_destroy_ipq(fp);
1064 #endif
1065
1066 /*
1067 * Create header for new ip packet by modifying header of first
1068 * packet; dequeue and discard fragment reassembly header.
1069 * Make header visible.
1070 */
1071 ip->ip_len = (ip->ip_hl << 2) + next;
1072 ip->ip_src = fp->ipq_src;
1073 ip->ip_dst = fp->ipq_dst;
1074 TAILQ_REMOVE(head, fp, ipq_list);
1075 nipq--;
1076 (void) m_free(dtom(fp));
1077 m->m_len += (ip->ip_hl << 2);
1078 m->m_data -= (ip->ip_hl << 2);
1079 /* some debugging cruft by sklower, below, will go away soon */
1080 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */
1081 m_fixhdr(m);
1082 ipstat.ips_reassembled++;
1083 IPQ_UNLOCK();
1084 return (m);
1085
1086 dropfrag:
1087 ipstat.ips_fragdropped++;
1088 if (fp != NULL)
1089 fp->ipq_nfrags--;
1090 m_freem(m);
1091 done:
1092 IPQ_UNLOCK();
1093 return (NULL);
1094
1095 #undef GETIP
1096 }
1097
1098 /*
1099 * Free a fragment reassembly header and all
1100 * associated datagrams.
1101 */
1102 static void
1103 ip_freef(fhp, fp)
1104 struct ipqhead *fhp;
1105 struct ipq *fp;
1106 {
1107 register struct mbuf *q;
1108
1109 IPQ_LOCK_ASSERT();
1110
1111 while (fp->ipq_frags) {
1112 q = fp->ipq_frags;
1113 fp->ipq_frags = q->m_nextpkt;
1114 m_freem(q);
1115 }
1116 TAILQ_REMOVE(fhp, fp, ipq_list);
1117 (void) m_free(dtom(fp));
1118 nipq--;
1119 }
1120
1121 /*
1122 * IP timer processing;
1123 * if a timer expires on a reassembly
1124 * queue, discard it.
1125 */
1126 void
1127 ip_slowtimo()
1128 {
1129 register struct ipq *fp;
1130 int s = splnet();
1131 int i;
1132
1133 IPQ_LOCK();
1134 for (i = 0; i < IPREASS_NHASH; i++) {
1135 for(fp = TAILQ_FIRST(&ipq[i]); fp;) {
1136 struct ipq *fpp;
1137
1138 fpp = fp;
1139 fp = TAILQ_NEXT(fp, ipq_list);
1140 if(--fpp->ipq_ttl == 0) {
1141 ipstat.ips_fragtimeout += fpp->ipq_nfrags;
1142 ip_freef(&ipq[i], fpp);
1143 }
1144 }
1145 }
1146 /*
1147 * If we are over the maximum number of fragments
1148 * (due to the limit being lowered), drain off
1149 * enough to get down to the new limit.
1150 */
1151 if (maxnipq >= 0 && nipq > maxnipq) {
1152 for (i = 0; i < IPREASS_NHASH; i++) {
1153 while (nipq > maxnipq && !TAILQ_EMPTY(&ipq[i])) {
1154 ipstat.ips_fragdropped +=
1155 TAILQ_FIRST(&ipq[i])->ipq_nfrags;
1156 ip_freef(&ipq[i], TAILQ_FIRST(&ipq[i]));
1157 }
1158 }
1159 }
1160 IPQ_UNLOCK();
1161 splx(s);
1162 }
1163
1164 /*
1165 * Drain off all datagram fragments.
1166 */
1167 void
1168 ip_drain()
1169 {
1170 int i;
1171
1172 IPQ_LOCK();
1173 for (i = 0; i < IPREASS_NHASH; i++) {
1174 while(!TAILQ_EMPTY(&ipq[i])) {
1175 ipstat.ips_fragdropped +=
1176 TAILQ_FIRST(&ipq[i])->ipq_nfrags;
1177 ip_freef(&ipq[i], TAILQ_FIRST(&ipq[i]));
1178 }
1179 }
1180 IPQ_UNLOCK();
1181 in_rtqdrain();
1182 }
1183
1184 /*
1185 * Do option processing on a datagram,
1186 * possibly discarding it if bad options are encountered,
1187 * or forwarding it if source-routed.
1188 * The pass argument is used when operating in the IPSTEALTH
1189 * mode to tell what options to process:
1190 * [LS]SRR (pass 0) or the others (pass 1).
1191 * The reason for as many as two passes is that when doing IPSTEALTH,
1192 * non-routing options should be processed only if the packet is for us.
1193 * Returns 1 if packet has been forwarded/freed,
1194 * 0 if the packet should be processed further.
1195 */
1196 static int
1197 ip_dooptions(struct mbuf *m, int pass)
1198 {
1199 struct ip *ip = mtod(m, struct ip *);
1200 u_char *cp;
1201 struct in_ifaddr *ia;
1202 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1203 struct in_addr *sin, dst;
1204 n_time ntime;
1205 struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
1206
1207 /* ignore or reject packets with IP options */
1208 if (ip_doopts == 0)
1209 return 0;
1210 else if (ip_doopts == 2) {
1211 type = ICMP_UNREACH;
1212 code = ICMP_UNREACH_FILTER_PROHIB;
1213 goto bad;
1214 }
1215
1216 dst = ip->ip_dst;
1217 cp = (u_char *)(ip + 1);
1218 cnt = (ip->ip_hl << 2) - sizeof (struct ip);
1219 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1220 opt = cp[IPOPT_OPTVAL];
1221 if (opt == IPOPT_EOL)
1222 break;
1223 if (opt == IPOPT_NOP)
1224 optlen = 1;
1225 else {
1226 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1227 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1228 goto bad;
1229 }
1230 optlen = cp[IPOPT_OLEN];
1231 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1232 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1233 goto bad;
1234 }
1235 }
1236 switch (opt) {
1237
1238 default:
1239 break;
1240
1241 /*
1242 * Source routing with record.
1243 * Find interface with current destination address.
1244 * If none on this machine then drop if strictly routed,
1245 * or do nothing if loosely routed.
1246 * Record interface address and bring up next address
1247 * component. If strictly routed make sure next
1248 * address is on directly accessible net.
1249 */
1250 case IPOPT_LSRR:
1251 case IPOPT_SSRR:
1252 #ifdef IPSTEALTH
1253 if (ipstealth && pass > 0)
1254 break;
1255 #endif
1256 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1257 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1258 goto bad;
1259 }
1260 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1261 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1262 goto bad;
1263 }
1264 ipaddr.sin_addr = ip->ip_dst;
1265 ia = (struct in_ifaddr *)
1266 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1267 if (ia == NULL) {
1268 if (opt == IPOPT_SSRR) {
1269 type = ICMP_UNREACH;
1270 code = ICMP_UNREACH_SRCFAIL;
1271 goto bad;
1272 }
1273 if (!ip_dosourceroute)
1274 goto nosourcerouting;
1275 /*
1276 * Loose routing, and not at next destination
1277 * yet; nothing to do except forward.
1278 */
1279 break;
1280 }
1281 off--; /* 0 origin */
1282 if (off > optlen - (int)sizeof(struct in_addr)) {
1283 /*
1284 * End of source route. Should be for us.
1285 */
1286 if (!ip_acceptsourceroute)
1287 goto nosourcerouting;
1288 save_rte(m, cp, ip->ip_src);
1289 break;
1290 }
1291 #ifdef IPSTEALTH
1292 if (ipstealth)
1293 goto dropit;
1294 #endif
1295 if (!ip_dosourceroute) {
1296 if (ipforwarding) {
1297 char buf[16]; /* aaa.bbb.ccc.ddd\0 */
1298 /*
1299 * Acting as a router, so generate ICMP
1300 */
1301 nosourcerouting:
1302 strcpy(buf, inet_ntoa(ip->ip_dst));
1303 log(LOG_WARNING,
1304 "attempted source route from %s to %s\n",
1305 inet_ntoa(ip->ip_src), buf);
1306 type = ICMP_UNREACH;
1307 code = ICMP_UNREACH_SRCFAIL;
1308 goto bad;
1309 } else {
1310 /*
1311 * Not acting as a router, so silently drop.
1312 */
1313 #ifdef IPSTEALTH
1314 dropit:
1315 #endif
1316 ipstat.ips_cantforward++;
1317 m_freem(m);
1318 return (1);
1319 }
1320 }
1321
1322 /*
1323 * locate outgoing interface
1324 */
1325 (void)memcpy(&ipaddr.sin_addr, cp + off,
1326 sizeof(ipaddr.sin_addr));
1327
1328 if (opt == IPOPT_SSRR) {
1329 #define INA struct in_ifaddr *
1330 #define SA struct sockaddr *
1331 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == NULL)
1332 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1333 } else
1334 ia = ip_rtaddr(ipaddr.sin_addr);
1335 if (ia == NULL) {
1336 type = ICMP_UNREACH;
1337 code = ICMP_UNREACH_SRCFAIL;
1338 goto bad;
1339 }
1340 ip->ip_dst = ipaddr.sin_addr;
1341 (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1342 sizeof(struct in_addr));
1343 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1344 /*
1345 * Let ip_intr's mcast routing check handle mcast pkts
1346 */
1347 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1348 break;
1349
1350 case IPOPT_RR:
1351 #ifdef IPSTEALTH
1352 if (ipstealth && pass == 0)
1353 break;
1354 #endif
1355 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1356 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1357 goto bad;
1358 }
1359 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1360 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1361 goto bad;
1362 }
1363 /*
1364 * If no space remains, ignore.
1365 */
1366 off--; /* 0 origin */
1367 if (off > optlen - (int)sizeof(struct in_addr))
1368 break;
1369 (void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1370 sizeof(ipaddr.sin_addr));
1371 /*
1372 * locate outgoing interface; if we're the destination,
1373 * use the incoming interface (should be same).
1374 */
1375 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL &&
1376 (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1377 type = ICMP_UNREACH;
1378 code = ICMP_UNREACH_HOST;
1379 goto bad;
1380 }
1381 (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1382 sizeof(struct in_addr));
1383 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1384 break;
1385
1386 case IPOPT_TS:
1387 #ifdef IPSTEALTH
1388 if (ipstealth && pass == 0)
1389 break;
1390 #endif
1391 code = cp - (u_char *)ip;
1392 if (optlen < 4 || optlen > 40) {
1393 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1394 goto bad;
1395 }
1396 if ((off = cp[IPOPT_OFFSET]) < 5) {
1397 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1398 goto bad;
1399 }
1400 if (off > optlen - (int)sizeof(int32_t)) {
1401 cp[IPOPT_OFFSET + 1] += (1 << 4);
1402 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1403 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1404 goto bad;
1405 }
1406 break;
1407 }
1408 off--; /* 0 origin */
1409 sin = (struct in_addr *)(cp + off);
1410 switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1411
1412 case IPOPT_TS_TSONLY:
1413 break;
1414
1415 case IPOPT_TS_TSANDADDR:
1416 if (off + sizeof(n_time) +
1417 sizeof(struct in_addr) > optlen) {
1418 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1419 goto bad;
1420 }
1421 ipaddr.sin_addr = dst;
1422 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1423 m->m_pkthdr.rcvif);
1424 if (ia == NULL)
1425 continue;
1426 (void)memcpy(sin, &IA_SIN(ia)->sin_addr,
1427 sizeof(struct in_addr));
1428 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1429 off += sizeof(struct in_addr);
1430 break;
1431
1432 case IPOPT_TS_PRESPEC:
1433 if (off + sizeof(n_time) +
1434 sizeof(struct in_addr) > optlen) {
1435 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1436 goto bad;
1437 }
1438 (void)memcpy(&ipaddr.sin_addr, sin,
1439 sizeof(struct in_addr));
1440 if (ifa_ifwithaddr((SA)&ipaddr) == NULL)
1441 continue;
1442 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1443 off += sizeof(struct in_addr);
1444 break;
1445
1446 default:
1447 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1448 goto bad;
1449 }
1450 ntime = iptime();
1451 (void)memcpy(cp + off, &ntime, sizeof(n_time));
1452 cp[IPOPT_OFFSET] += sizeof(n_time);
1453 }
1454 }
1455 if (forward && ipforwarding) {
1456 ip_forward(m, 1);
1457 return (1);
1458 }
1459 return (0);
1460 bad:
1461 icmp_error(m, type, code, 0, 0);
1462 ipstat.ips_badoptions++;
1463 return (1);
1464 }
1465
1466 /*
1467 * Given address of next destination (final or next hop),
1468 * return internet address info of interface to be used to get there.
1469 */
1470 struct in_ifaddr *
1471 ip_rtaddr(dst)
1472 struct in_addr dst;
1473 {
1474 struct route sro;
1475 struct sockaddr_in *sin;
1476 struct in_ifaddr *ifa;
1477
1478 bzero(&sro, sizeof(sro));
1479 sin = (struct sockaddr_in *)&sro.ro_dst;
1480 sin->sin_family = AF_INET;
1481 sin->sin_len = sizeof(*sin);
1482 sin->sin_addr = dst;
1483 rtalloc_ign(&sro, RTF_CLONING);
1484
1485 if (sro.ro_rt == NULL)
1486 return (NULL);
1487
1488 ifa = ifatoia(sro.ro_rt->rt_ifa);
1489 RTFREE(sro.ro_rt);
1490 return (ifa);
1491 }
1492
1493 /*
1494 * Save incoming source route for use in replies,
1495 * to be picked up later by ip_srcroute if the receiver is interested.
1496 */
1497 static void
1498 save_rte(m, option, dst)
1499 struct mbuf *m;
1500 u_char *option;
1501 struct in_addr dst;
1502 {
1503 unsigned olen;
1504 struct ipopt_tag *opts;
1505
1506 opts = (struct ipopt_tag *)m_tag_get(PACKET_TAG_IPOPTIONS,
1507 sizeof(struct ipopt_tag), M_NOWAIT);
1508 if (opts == NULL)
1509 return;
1510
1511 olen = option[IPOPT_OLEN];
1512 #ifdef DIAGNOSTIC
1513 if (ipprintfs)
1514 printf("save_rte: olen %d\n", olen);
1515 #endif
1516 if (olen > sizeof(opts->ip_srcrt) - (1 + sizeof(dst)))
1517 return;
1518 bcopy(option, opts->ip_srcrt.srcopt, olen);
1519 opts->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1520 opts->ip_srcrt.dst = dst;
1521 m_tag_prepend(m, (struct m_tag *)opts);
1522 }
1523
1524 /*
1525 * Retrieve incoming source route for use in replies,
1526 * in the same form used by setsockopt.
1527 * The first hop is placed before the options, will be removed later.
1528 */
1529 struct mbuf *
1530 ip_srcroute(m0)
1531 struct mbuf *m0;
1532 {
1533 register struct in_addr *p, *q;
1534 register struct mbuf *m;
1535 struct ipopt_tag *opts;
1536
1537 opts = (struct ipopt_tag *)m_tag_find(m0, PACKET_TAG_IPOPTIONS, NULL);
1538 if (opts == NULL)
1539 return (NULL);
1540
1541 if (opts->ip_nhops == 0)
1542 return (NULL);
1543 m = m_get(M_DONTWAIT, MT_HEADER);
1544 if (m == NULL)
1545 return (NULL);
1546
1547 #define OPTSIZ (sizeof(opts->ip_srcrt.nop) + sizeof(opts->ip_srcrt.srcopt))
1548
1549 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1550 m->m_len = opts->ip_nhops * sizeof(struct in_addr) +
1551 sizeof(struct in_addr) + OPTSIZ;
1552 #ifdef DIAGNOSTIC
1553 if (ipprintfs)
1554 printf("ip_srcroute: nhops %d mlen %d", opts->ip_nhops, m->m_len);
1555 #endif
1556
1557 /*
1558 * First save first hop for return route
1559 */
1560 p = &(opts->ip_srcrt.route[opts->ip_nhops - 1]);
1561 *(mtod(m, struct in_addr *)) = *p--;
1562 #ifdef DIAGNOSTIC
1563 if (ipprintfs)
1564 printf(" hops %lx", (u_long)ntohl(mtod(m, struct in_addr *)->s_addr));
1565 #endif
1566
1567 /*
1568 * Copy option fields and padding (nop) to mbuf.
1569 */
1570 opts->ip_srcrt.nop = IPOPT_NOP;
1571 opts->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1572 (void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
1573 &(opts->ip_srcrt.nop), OPTSIZ);
1574 q = (struct in_addr *)(mtod(m, caddr_t) +
1575 sizeof(struct in_addr) + OPTSIZ);
1576 #undef OPTSIZ
1577 /*
1578 * Record return path as an IP source route,
1579 * reversing the path (pointers are now aligned).
1580 */
1581 while (p >= opts->ip_srcrt.route) {
1582 #ifdef DIAGNOSTIC
1583 if (ipprintfs)
1584 printf(" %lx", (u_long)ntohl(q->s_addr));
1585 #endif
1586 *q++ = *p--;
1587 }
1588 /*
1589 * Last hop goes to final destination.
1590 */
1591 *q = opts->ip_srcrt.dst;
1592 #ifdef DIAGNOSTIC
1593 if (ipprintfs)
1594 printf(" %lx\n", (u_long)ntohl(q->s_addr));
1595 #endif
1596 m_tag_delete(m0, (struct m_tag *)opts);
1597 return (m);
1598 }
1599
1600 /*
1601 * Strip out IP options, at higher
1602 * level protocol in the kernel.
1603 * Second argument is buffer to which options
1604 * will be moved, and return value is their length.
1605 * XXX should be deleted; last arg currently ignored.
1606 */
1607 void
1608 ip_stripoptions(m, mopt)
1609 register struct mbuf *m;
1610 struct mbuf *mopt;
1611 {
1612 register int i;
1613 struct ip *ip = mtod(m, struct ip *);
1614 register caddr_t opts;
1615 int olen;
1616
1617 olen = (ip->ip_hl << 2) - sizeof (struct ip);
1618 opts = (caddr_t)(ip + 1);
1619 i = m->m_len - (sizeof (struct ip) + olen);
1620 bcopy(opts + olen, opts, (unsigned)i);
1621 m->m_len -= olen;
1622 if (m->m_flags & M_PKTHDR)
1623 m->m_pkthdr.len -= olen;
1624 ip->ip_v = IPVERSION;
1625 ip->ip_hl = sizeof(struct ip) >> 2;
1626 }
1627
1628 u_char inetctlerrmap[PRC_NCMDS] = {
1629 0, 0, 0, 0,
1630 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1631 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1632 EMSGSIZE, EHOSTUNREACH, 0, 0,
1633 0, 0, EHOSTUNREACH, 0,
1634 ENOPROTOOPT, ECONNREFUSED
1635 };
1636
1637 /*
1638 * Forward a packet. If some error occurs return the sender
1639 * an icmp packet. Note we can't always generate a meaningful
1640 * icmp message because icmp doesn't have a large enough repertoire
1641 * of codes and types.
1642 *
1643 * If not forwarding, just drop the packet. This could be confusing
1644 * if ipforwarding was zero but some routing protocol was advancing
1645 * us as a gateway to somewhere. However, we must let the routing
1646 * protocol deal with that.
1647 *
1648 * The srcrt parameter indicates whether the packet is being forwarded
1649 * via a source route.
1650 */
1651 void
1652 ip_forward(struct mbuf *m, int srcrt)
1653 {
1654 struct ip *ip = mtod(m, struct ip *);
1655 struct in_ifaddr *ia = NULL;
1656 int error, type = 0, code = 0;
1657 struct mbuf *mcopy;
1658 struct in_addr dest;
1659 struct ifnet *destifp, dummyifp;
1660
1661 #ifdef DIAGNOSTIC
1662 if (ipprintfs)
1663 printf("forward: src %lx dst %lx ttl %x\n",
1664 (u_long)ip->ip_src.s_addr, (u_long)ip->ip_dst.s_addr,
1665 ip->ip_ttl);
1666 #endif
1667
1668
1669 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1670 ipstat.ips_cantforward++;
1671 m_freem(m);
1672 return;
1673 }
1674 #ifdef IPSTEALTH
1675 if (!ipstealth) {
1676 #endif
1677 if (ip->ip_ttl <= IPTTLDEC) {
1678 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
1679 0, 0);
1680 return;
1681 }
1682 #ifdef IPSTEALTH
1683 }
1684 #endif
1685
1686 if (!srcrt && (ia = ip_rtaddr(ip->ip_dst)) == NULL) {
1687 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
1688 return;
1689 }
1690
1691 /*
1692 * Save the IP header and at most 8 bytes of the payload,
1693 * in case we need to generate an ICMP message to the src.
1694 *
1695 * XXX this can be optimized a lot by saving the data in a local
1696 * buffer on the stack (72 bytes at most), and only allocating the
1697 * mbuf if really necessary. The vast majority of the packets
1698 * are forwarded without having to send an ICMP back (either
1699 * because unnecessary, or because rate limited), so we are
1700 * really we are wasting a lot of work here.
1701 *
1702 * We don't use m_copy() because it might return a reference
1703 * to a shared cluster. Both this function and ip_output()
1704 * assume exclusive access to the IP header in `m', so any
1705 * data in a cluster may change before we reach icmp_error().
1706 */
1707 MGET(mcopy, M_DONTWAIT, m->m_type);
1708 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_DONTWAIT)) {
1709 /*
1710 * It's probably ok if the pkthdr dup fails (because
1711 * the deep copy of the tag chain failed), but for now
1712 * be conservative and just discard the copy since
1713 * code below may some day want the tags.
1714 */
1715 m_free(mcopy);
1716 mcopy = NULL;
1717 }
1718 if (mcopy != NULL) {
1719 mcopy->m_len = imin((ip->ip_hl << 2) + 8,
1720 (int)ip->ip_len);
1721 mcopy->m_pkthdr.len = mcopy->m_len;
1722 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1723 }
1724
1725 #ifdef IPSTEALTH
1726 if (!ipstealth) {
1727 #endif
1728 ip->ip_ttl -= IPTTLDEC;
1729 #ifdef IPSTEALTH
1730 }
1731 #endif
1732
1733 /*
1734 * If forwarding packet using same interface that it came in on,
1735 * perhaps should send a redirect to sender to shortcut a hop.
1736 * Only send redirect if source is sending directly to us,
1737 * and if packet was not source routed (or has any options).
1738 * Also, don't send redirect if forwarding using a default route
1739 * or a route modified by a redirect.
1740 */
1741 dest.s_addr = 0;
1742 if (!srcrt && ipsendredirects && ia->ia_ifp == m->m_pkthdr.rcvif) {
1743 struct sockaddr_in *sin;
1744 struct route ro;
1745 struct rtentry *rt;
1746
1747 bzero(&ro, sizeof(ro));
1748 sin = (struct sockaddr_in *)&ro.ro_dst;
1749 sin->sin_family = AF_INET;
1750 sin->sin_len = sizeof(*sin);
1751 sin->sin_addr = ip->ip_dst;
1752 rtalloc_ign(&ro, RTF_CLONING);
1753
1754 rt = ro.ro_rt;
1755
1756 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1757 satosin(rt_key(rt))->sin_addr.s_addr != 0) {
1758 #define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1759 u_long src = ntohl(ip->ip_src.s_addr);
1760
1761 if (RTA(rt) &&
1762 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1763 if (rt->rt_flags & RTF_GATEWAY)
1764 dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
1765 else
1766 dest.s_addr = ip->ip_dst.s_addr;
1767 /* Router requirements says to only send host redirects */
1768 type = ICMP_REDIRECT;
1769 code = ICMP_REDIRECT_HOST;
1770 #ifdef DIAGNOSTIC
1771 if (ipprintfs)
1772 printf("redirect (%d) to %lx\n", code, (u_long)dest.s_addr);
1773 #endif
1774 }
1775 }
1776 if (rt)
1777 RTFREE(rt);
1778 }
1779
1780 error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
1781 if (error)
1782 ipstat.ips_cantforward++;
1783 else {
1784 ipstat.ips_forward++;
1785 if (type)
1786 ipstat.ips_redirectsent++;
1787 else {
1788 if (mcopy)
1789 m_freem(mcopy);
1790 return;
1791 }
1792 }
1793 if (mcopy == NULL)
1794 return;
1795 destifp = NULL;
1796
1797 switch (error) {
1798
1799 case 0: /* forwarded, but need redirect */
1800 /* type, code set above */
1801 break;
1802
1803 case ENETUNREACH: /* shouldn't happen, checked above */
1804 case EHOSTUNREACH:
1805 case ENETDOWN:
1806 case EHOSTDOWN:
1807 default:
1808 type = ICMP_UNREACH;
1809 code = ICMP_UNREACH_HOST;
1810 break;
1811
1812 case EMSGSIZE:
1813 type = ICMP_UNREACH;
1814 code = ICMP_UNREACH_NEEDFRAG;
1815 #if defined(IPSEC) || defined(FAST_IPSEC)
1816 /*
1817 * If the packet is routed over IPsec tunnel, tell the
1818 * originator the tunnel MTU.
1819 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1820 * XXX quickhack!!!
1821 */
1822 {
1823 struct secpolicy *sp = NULL;
1824 int ipsecerror;
1825 int ipsechdr;
1826 struct route *ro;
1827
1828 #ifdef IPSEC
1829 sp = ipsec4_getpolicybyaddr(mcopy,
1830 IPSEC_DIR_OUTBOUND,
1831 IP_FORWARDING,
1832 &ipsecerror);
1833 #else /* FAST_IPSEC */
1834 sp = ipsec_getpolicybyaddr(mcopy,
1835 IPSEC_DIR_OUTBOUND,
1836 IP_FORWARDING,
1837 &ipsecerror);
1838 #endif
1839 if (sp != NULL) {
1840 /* count IPsec header size */
1841 ipsechdr = ipsec4_hdrsiz(mcopy,
1842 IPSEC_DIR_OUTBOUND,
1843 NULL);
1844
1845 /*
1846 * find the correct route for outer IPv4
1847 * header, compute tunnel MTU.
1848 *
1849 * XXX BUG ALERT
1850 * The "dummyifp" code relies upon the fact
1851 * that icmp_error() touches only ifp->if_mtu.
1852 */
1853 /*XXX*/
1854 destifp = NULL;
1855 if (sp->req != NULL
1856 && sp->req->sav != NULL
1857 && sp->req->sav->sah != NULL) {
1858 ro = &sp->req->sav->sah->sa_route;
1859 if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1860 dummyifp.if_mtu =
1861 ro->ro_rt->rt_rmx.rmx_mtu ?
1862 ro->ro_rt->rt_rmx.rmx_mtu :
1863 ro->ro_rt->rt_ifp->if_mtu;
1864 dummyifp.if_mtu -= ipsechdr;
1865 destifp = &dummyifp;
1866 }
1867 }
1868
1869 #ifdef IPSEC
1870 key_freesp(sp);
1871 #else /* FAST_IPSEC */
1872 KEY_FREESP(&sp);
1873 #endif
1874 ipstat.ips_cantfrag++;
1875 break;
1876 } else
1877 #endif /*IPSEC || FAST_IPSEC*/
1878 /*
1879 * When doing source routing 'ia' can be NULL. Fall back
1880 * to the minimum guaranteed routeable packet size and use
1881 * the same hack as IPSEC to setup a dummyifp for icmp.
1882 */
1883 if (ia == NULL) {
1884 dummyifp.if_mtu = IP_MSS;
1885 destifp = &dummyifp;
1886 } else
1887 destifp = ia->ia_ifp;
1888 #if defined(IPSEC) || defined(FAST_IPSEC)
1889 }
1890 #endif /*IPSEC || FAST_IPSEC*/
1891 ipstat.ips_cantfrag++;
1892 break;
1893
1894 case ENOBUFS:
1895 /*
1896 * A router should not generate ICMP_SOURCEQUENCH as
1897 * required in RFC1812 Requirements for IP Version 4 Routers.
1898 * Source quench could be a big problem under DoS attacks,
1899 * or if the underlying interface is rate-limited.
1900 * Those who need source quench packets may re-enable them
1901 * via the net.inet.ip.sendsourcequench sysctl.
1902 */
1903 if (ip_sendsourcequench == 0) {
1904 m_freem(mcopy);
1905 return;
1906 } else {
1907 type = ICMP_SOURCEQUENCH;
1908 code = 0;
1909 }
1910 break;
1911
1912 case EACCES: /* ipfw denied packet */
1913 m_freem(mcopy);
1914 return;
1915 }
1916 icmp_error(mcopy, type, code, dest.s_addr, destifp);
1917 }
1918
1919 void
1920 ip_savecontrol(inp, mp, ip, m)
1921 register struct inpcb *inp;
1922 register struct mbuf **mp;
1923 register struct ip *ip;
1924 register struct mbuf *m;
1925 {
1926 if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
1927 struct bintime bt;
1928
1929 bintime(&bt);
1930 if (inp->inp_socket->so_options & SO_BINTIME) {
1931 *mp = sbcreatecontrol((caddr_t) &bt, sizeof(bt),
1932 SCM_BINTIME, SOL_SOCKET);
1933 if (*mp)
1934 mp = &(*mp)->m_next;
1935 }
1936 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1937 struct timeval tv;
1938
1939 bintime2timeval(&bt, &tv);
1940 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1941 SCM_TIMESTAMP, SOL_SOCKET);
1942 if (*mp)
1943 mp = &(*mp)->m_next;
1944 }
1945 }
1946 if (inp->inp_flags & INP_RECVDSTADDR) {
1947 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1948 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1949 if (*mp)
1950 mp = &(*mp)->m_next;
1951 }
1952 if (inp->inp_flags & INP_RECVTTL) {
1953 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
1954 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1955 if (*mp)
1956 mp = &(*mp)->m_next;
1957 }
1958 #ifdef notyet
1959 /* XXX
1960 * Moving these out of udp_input() made them even more broken
1961 * than they already were.
1962 */
1963 /* options were tossed already */
1964 if (inp->inp_flags & INP_RECVOPTS) {
1965 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1966 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1967 if (*mp)
1968 mp = &(*mp)->m_next;
1969 }
1970 /* ip_srcroute doesn't do what we want here, need to fix */
1971 if (inp->inp_flags & INP_RECVRETOPTS) {
1972 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
1973 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1974 if (*mp)
1975 mp = &(*mp)->m_next;
1976 }
1977 #endif
1978 if (inp->inp_flags & INP_RECVIF) {
1979 struct ifnet *ifp;
1980 struct sdlbuf {
1981 struct sockaddr_dl sdl;
1982 u_char pad[32];
1983 } sdlbuf;
1984 struct sockaddr_dl *sdp;
1985 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1986
1987 if (((ifp = m->m_pkthdr.rcvif))
1988 && ( ifp->if_index && (ifp->if_index <= if_index))) {
1989 sdp = (struct sockaddr_dl *)
1990 (ifaddr_byindex(ifp->if_index)->ifa_addr);
1991 /*
1992 * Change our mind and don't try copy.
1993 */
1994 if ((sdp->sdl_family != AF_LINK)
1995 || (sdp->sdl_len > sizeof(sdlbuf))) {
1996 goto makedummy;
1997 }
1998 bcopy(sdp, sdl2, sdp->sdl_len);
1999 } else {
2000 makedummy:
2001 sdl2->sdl_len
2002 = offsetof(struct sockaddr_dl, sdl_data[0]);
2003 sdl2->sdl_family = AF_LINK;
2004 sdl2->sdl_index = 0;
2005 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2006 }
2007 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2008 IP_RECVIF, IPPROTO_IP);
2009 if (*mp)
2010 mp = &(*mp)->m_next;
2011 }
2012 }
2013
2014 /*
2015 * XXX these routines are called from the upper part of the kernel.
2016 * They need to be locked when we remove Giant.
2017 *
2018 * They could also be moved to ip_mroute.c, since all the RSVP
2019 * handling is done there already.
2020 */
2021 static int ip_rsvp_on;
2022 struct socket *ip_rsvpd;
2023 int
2024 ip_rsvp_init(struct socket *so)
2025 {
2026 if (so->so_type != SOCK_RAW ||
2027 so->so_proto->pr_protocol != IPPROTO_RSVP)
2028 return EOPNOTSUPP;
2029
2030 if (ip_rsvpd != NULL)
2031 return EADDRINUSE;
2032
2033 ip_rsvpd = so;
2034 /*
2035 * This may seem silly, but we need to be sure we don't over-increment
2036 * the RSVP counter, in case something slips up.
2037 */
2038 if (!ip_rsvp_on) {
2039 ip_rsvp_on = 1;
2040 rsvp_on++;
2041 }
2042
2043 return 0;
2044 }
2045
2046 int
2047 ip_rsvp_done(void)
2048 {
2049 ip_rsvpd = NULL;
2050 /*
2051 * This may seem silly, but we need to be sure we don't over-decrement
2052 * the RSVP counter, in case something slips up.
2053 */
2054 if (ip_rsvp_on) {
2055 ip_rsvp_on = 0;
2056 rsvp_on--;
2057 }
2058 return 0;
2059 }
2060
2061 void
2062 rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */
2063 {
2064 if (rsvp_input_p) { /* call the real one if loaded */
2065 rsvp_input_p(m, off);
2066 return;
2067 }
2068
2069 /* Can still get packets with rsvp_on = 0 if there is a local member
2070 * of the group to which the RSVP packet is addressed. But in this
2071 * case we want to throw the packet away.
2072 */
2073
2074 if (!rsvp_on) {
2075 m_freem(m);
2076 return;
2077 }
2078
2079 if (ip_rsvpd != NULL) {
2080 rip_input(m, off);
2081 return;
2082 }
2083 /* Drop the packet */
2084 m_freem(m);
2085 }
Cache object: 010f62eb64336ca74f6b43a12cce381b
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