Annotation of src/sys/netinet/ip_input.c, Revision 1.91
1.91 ! thorpej 1: /* $NetBSD: ip_input.c,v 1.90 1999/07/06 12:23:20 itojun Exp $ */
1.89 itojun 2:
3: /*
4: * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: * 3. Neither the name of the project nor the names of its contributors
16: * may be used to endorse or promote products derived from this software
17: * without specific prior written permission.
18: *
19: * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22: * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29: * SUCH DAMAGE.
30: */
1.76 thorpej 31:
32: /*-
33: * Copyright (c) 1998 The NetBSD Foundation, Inc.
34: * All rights reserved.
35: *
36: * This code is derived from software contributed to The NetBSD Foundation
37: * by Public Access Networks Corporation ("Panix"). It was developed under
38: * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
39: *
40: * Redistribution and use in source and binary forms, with or without
41: * modification, are permitted provided that the following conditions
42: * are met:
43: * 1. Redistributions of source code must retain the above copyright
44: * notice, this list of conditions and the following disclaimer.
45: * 2. Redistributions in binary form must reproduce the above copyright
46: * notice, this list of conditions and the following disclaimer in the
47: * documentation and/or other materials provided with the distribution.
48: * 3. All advertising materials mentioning features or use of this software
49: * must display the following acknowledgement:
50: * This product includes software developed by the NetBSD
51: * Foundation, Inc. and its contributors.
52: * 4. Neither the name of The NetBSD Foundation nor the names of its
53: * contributors may be used to endorse or promote products derived
54: * from this software without specific prior written permission.
55: *
56: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
57: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
58: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
59: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
60: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
61: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
62: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
63: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
64: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
65: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
66: * POSSIBILITY OF SUCH DAMAGE.
67: */
1.14 cgd 68:
1.1 cgd 69: /*
1.13 mycroft 70: * Copyright (c) 1982, 1986, 1988, 1993
71: * The Regents of the University of California. All rights reserved.
1.1 cgd 72: *
73: * Redistribution and use in source and binary forms, with or without
74: * modification, are permitted provided that the following conditions
75: * are met:
76: * 1. Redistributions of source code must retain the above copyright
77: * notice, this list of conditions and the following disclaimer.
78: * 2. Redistributions in binary form must reproduce the above copyright
79: * notice, this list of conditions and the following disclaimer in the
80: * documentation and/or other materials provided with the distribution.
81: * 3. All advertising materials mentioning features or use of this software
82: * must display the following acknowledgement:
83: * This product includes software developed by the University of
84: * California, Berkeley and its contributors.
85: * 4. Neither the name of the University nor the names of its contributors
86: * may be used to endorse or promote products derived from this software
87: * without specific prior written permission.
88: *
89: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
90: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
91: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
92: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
93: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
94: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
95: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
96: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
97: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
98: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
99: * SUCH DAMAGE.
100: *
1.14 cgd 101: * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
1.1 cgd 102: */
1.55 scottr 103:
1.62 matt 104: #include "opt_gateway.h"
1.69 mrg 105: #include "opt_pfil_hooks.h"
1.91 ! thorpej 106: #include "opt_ipsec.h"
1.55 scottr 107: #include "opt_mrouting.h"
1.1 cgd 108:
1.5 mycroft 109: #include <sys/param.h>
110: #include <sys/systm.h>
111: #include <sys/malloc.h>
112: #include <sys/mbuf.h>
113: #include <sys/domain.h>
114: #include <sys/protosw.h>
115: #include <sys/socket.h>
1.44 thorpej 116: #include <sys/socketvar.h>
1.5 mycroft 117: #include <sys/errno.h>
118: #include <sys/time.h>
119: #include <sys/kernel.h>
1.28 christos 120: #include <sys/proc.h>
1.72 thorpej 121: #include <sys/pool.h>
1.28 christos 122:
123: #include <vm/vm.h>
124: #include <sys/sysctl.h>
1.1 cgd 125:
1.5 mycroft 126: #include <net/if.h>
1.44 thorpej 127: #include <net/if_dl.h>
1.5 mycroft 128: #include <net/route.h>
1.45 mrg 129: #include <net/pfil.h>
1.1 cgd 130:
1.5 mycroft 131: #include <netinet/in.h>
132: #include <netinet/in_systm.h>
133: #include <netinet/ip.h>
134: #include <netinet/in_pcb.h>
135: #include <netinet/in_var.h>
136: #include <netinet/ip_var.h>
137: #include <netinet/ip_icmp.h>
1.89 itojun 138: /* just for gif_ttl */
139: #include <netinet/in_gif.h>
140: #include "gif.h"
141:
142: #ifdef IPSEC
143: #include <netinet6/ipsec.h>
144: #include <netinet6/ah.h>
145: #ifdef IPSEC_ESP
146: #include <netinet6/esp.h>
147: #endif
148: #include <netkey/key.h>
149: #include <netkey/key_debug.h>
150: #endif
1.44 thorpej 151:
1.1 cgd 152: #ifndef IPFORWARDING
153: #ifdef GATEWAY
154: #define IPFORWARDING 1 /* forward IP packets not for us */
155: #else /* GATEWAY */
156: #define IPFORWARDING 0 /* don't forward IP packets not for us */
157: #endif /* GATEWAY */
158: #endif /* IPFORWARDING */
159: #ifndef IPSENDREDIRECTS
160: #define IPSENDREDIRECTS 1
161: #endif
1.26 thorpej 162: #ifndef IPFORWSRCRT
1.47 cjs 163: #define IPFORWSRCRT 1 /* forward source-routed packets */
164: #endif
165: #ifndef IPALLOWSRCRT
1.48 mrg 166: #define IPALLOWSRCRT 1 /* allow source-routed packets */
1.26 thorpej 167: #endif
1.53 kml 168: #ifndef IPMTUDISC
169: #define IPMTUDISC 0
170: #endif
1.60 kml 171: #ifndef IPMTUDISCTIMEOUT
1.61 kml 172: #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
1.60 kml 173: #endif
1.53 kml 174:
1.27 thorpej 175: /*
176: * Note: DIRECTED_BROADCAST is handled this way so that previous
177: * configuration using this option will Just Work.
178: */
179: #ifndef IPDIRECTEDBCAST
180: #ifdef DIRECTED_BROADCAST
181: #define IPDIRECTEDBCAST 1
182: #else
183: #define IPDIRECTEDBCAST 0
184: #endif /* DIRECTED_BROADCAST */
185: #endif /* IPDIRECTEDBCAST */
1.1 cgd 186: int ipforwarding = IPFORWARDING;
187: int ipsendredirects = IPSENDREDIRECTS;
1.13 mycroft 188: int ip_defttl = IPDEFTTL;
1.26 thorpej 189: int ip_forwsrcrt = IPFORWSRCRT;
1.27 thorpej 190: int ip_directedbcast = IPDIRECTEDBCAST;
1.47 cjs 191: int ip_allowsrcrt = IPALLOWSRCRT;
1.53 kml 192: int ip_mtudisc = IPMTUDISC;
1.60 kml 193: u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1 cgd 194: #ifdef DIAGNOSTIC
195: int ipprintfs = 0;
196: #endif
197:
1.60 kml 198: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
199:
1.1 cgd 200: extern struct domain inetdomain;
201: extern struct protosw inetsw[];
202: u_char ip_protox[IPPROTO_MAX];
203: int ipqmaxlen = IFQ_MAXLEN;
1.22 mycroft 204: struct in_ifaddrhead in_ifaddr;
1.57 tls 205: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.13 mycroft 206: struct ifqueue ipintrq;
1.63 matt 207: struct ipstat ipstat;
208: u_int16_t ip_id;
209: int ip_defttl;
1.75 thorpej 210:
1.63 matt 211: struct ipqhead ipq;
1.75 thorpej 212: int ipq_locked;
213:
214: static __inline int ipq_lock_try __P((void));
215: static __inline void ipq_unlock __P((void));
216:
217: static __inline int
218: ipq_lock_try()
219: {
220: int s;
221:
222: s = splimp();
223: if (ipq_locked) {
224: splx(s);
225: return (0);
226: }
227: ipq_locked = 1;
228: splx(s);
229: return (1);
230: }
231:
232: static __inline void
233: ipq_unlock()
234: {
235: int s;
236:
237: s = splimp();
238: ipq_locked = 0;
239: splx(s);
240: }
241:
242: #ifdef DIAGNOSTIC
243: #define IPQ_LOCK() \
244: do { \
245: if (ipq_lock_try() == 0) { \
246: printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
247: panic("ipq_lock"); \
248: } \
249: } while (0)
250: #define IPQ_LOCK_CHECK() \
251: do { \
252: if (ipq_locked == 0) { \
253: printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
254: panic("ipq lock check"); \
255: } \
256: } while (0)
257: #else
258: #define IPQ_LOCK() (void) ipq_lock_try()
259: #define IPQ_LOCK_CHECK() /* nothing */
260: #endif
261:
262: #define IPQ_UNLOCK() ipq_unlock()
1.1 cgd 263:
1.72 thorpej 264: struct pool ipqent_pool;
265:
1.1 cgd 266: /*
267: * We need to save the IP options in case a protocol wants to respond
268: * to an incoming packet over the same route if the packet got here
269: * using IP source routing. This allows connection establishment and
270: * maintenance when the remote end is on a network that is not known
271: * to us.
272: */
273: int ip_nhops = 0;
274: static struct ip_srcrt {
275: struct in_addr dst; /* final destination */
276: char nop; /* one NOP to align */
277: char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
278: struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
279: } ip_srcrt;
280:
1.13 mycroft 281: static void save_rte __P((u_char *, struct in_addr));
1.35 mycroft 282:
1.1 cgd 283: /*
284: * IP initialization: fill in IP protocol switch table.
285: * All protocols not implemented in kernel go to raw IP protocol handler.
286: */
1.8 mycroft 287: void
1.1 cgd 288: ip_init()
289: {
290: register struct protosw *pr;
291: register int i;
292:
1.72 thorpej 293: pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
294: 0, NULL, NULL, M_IPQ);
295:
1.1 cgd 296: pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
297: if (pr == 0)
298: panic("ip_init");
299: for (i = 0; i < IPPROTO_MAX; i++)
300: ip_protox[i] = pr - inetsw;
301: for (pr = inetdomain.dom_protosw;
302: pr < inetdomain.dom_protoswNPROTOSW; pr++)
303: if (pr->pr_domain->dom_family == PF_INET &&
304: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
305: ip_protox[pr->pr_protocol] = pr - inetsw;
1.25 cgd 306: LIST_INIT(&ipq);
1.1 cgd 307: ip_id = time.tv_sec & 0xffff;
308: ipintrq.ifq_maxlen = ipqmaxlen;
1.22 mycroft 309: TAILQ_INIT(&in_ifaddr);
1.57 tls 310: in_ifaddrhashtbl =
311: hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash);
1.60 kml 312: if (ip_mtudisc != 0)
313: ip_mtudisc_timeout_q =
314: rt_timer_queue_create(ip_mtudisc_timeout);
1.73 thorpej 315: #ifdef GATEWAY
316: ipflow_init();
317: #endif
1.1 cgd 318: }
319:
320: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
321: struct route ipforward_rt;
322:
323: /*
1.89 itojun 324: * IP software interrupt routine
325: */
326: void
327: ipintr()
328: {
329: int s;
330: struct mbuf *m;
331:
332: while (1) {
333: s = splimp();
334: IF_DEQUEUE(&ipintrq, m);
335: splx(s);
336: if (m == 0)
337: return;
338: ip_input(m);
339: }
340: }
341:
342: /*
1.1 cgd 343: * Ip input routine. Checksum and byte swap header. If fragmented
344: * try to reassemble. Process options. Pass to next level.
345: */
1.8 mycroft 346: void
1.89 itojun 347: ip_input(struct mbuf *m)
1.1 cgd 348: {
1.33 mrg 349: register struct ip *ip = NULL;
1.1 cgd 350: register struct ipq *fp;
351: register struct in_ifaddr *ia;
1.57 tls 352: register struct ifaddr *ifa;
1.25 cgd 353: struct ipqent *ipqe;
1.89 itojun 354: int hlen = 0, mff, len;
1.36 mrg 355: #ifdef PFIL_HOOKS
1.33 mrg 356: struct packet_filter_hook *pfh;
357: struct mbuf *m0;
1.43 mrg 358: int rv;
1.36 mrg 359: #endif /* PFIL_HOOKS */
1.1 cgd 360:
361: #ifdef DIAGNOSTIC
362: if ((m->m_flags & M_PKTHDR) == 0)
363: panic("ipintr no HDR");
364: #endif
1.89 itojun 365: #ifdef IPSEC
366: /*
367: * should the inner packet be considered authentic?
368: * see comment in ah4_input().
369: */
370: if (m) {
371: m->m_flags &= ~M_AUTHIPHDR;
372: m->m_flags &= ~M_AUTHIPDGM;
373: }
374: #endif
1.1 cgd 375: /*
376: * If no IP addresses have been set yet but the interfaces
377: * are receiving, can't do anything with incoming packets yet.
378: */
1.22 mycroft 379: if (in_ifaddr.tqh_first == 0)
1.1 cgd 380: goto bad;
381: ipstat.ips_total++;
382: if (m->m_len < sizeof (struct ip) &&
383: (m = m_pullup(m, sizeof (struct ip))) == 0) {
384: ipstat.ips_toosmall++;
1.89 itojun 385: return;
1.1 cgd 386: }
387: ip = mtod(m, struct ip *);
1.13 mycroft 388: if (ip->ip_v != IPVERSION) {
389: ipstat.ips_badvers++;
390: goto bad;
391: }
1.1 cgd 392: hlen = ip->ip_hl << 2;
393: if (hlen < sizeof(struct ip)) { /* minimum header length */
394: ipstat.ips_badhlen++;
395: goto bad;
396: }
397: if (hlen > m->m_len) {
398: if ((m = m_pullup(m, hlen)) == 0) {
399: ipstat.ips_badhlen++;
1.89 itojun 400: return;
1.1 cgd 401: }
402: ip = mtod(m, struct ip *);
403: }
1.85 hwr 404: /*
405: * we drop packets that have a multicast address as source
406: * as wanted by rfc 1112
407: */
408: if (IN_MULTICAST(ip->ip_src.s_addr)) {
409: goto bad;
410: }
411:
1.78 mycroft 412: if (in_cksum(m, hlen) != 0) {
1.1 cgd 413: ipstat.ips_badsum++;
414: goto bad;
415: }
416:
417: /*
418: * Convert fields to host representation.
419: */
420: NTOHS(ip->ip_len);
421: NTOHS(ip->ip_off);
1.35 mycroft 422: len = ip->ip_len;
1.81 proff 423:
424: /*
425: * Check for additional length bogosity
426: */
1.84 proff 427: if (len < hlen) {
1.81 proff 428: ipstat.ips_badlen++;
429: goto bad;
430: }
1.1 cgd 431:
432: /*
433: * Check that the amount of data in the buffers
434: * is as at least much as the IP header would have us expect.
435: * Trim mbufs if longer than we expect.
436: * Drop packet if shorter than we expect.
437: */
1.35 mycroft 438: if (m->m_pkthdr.len < len) {
1.1 cgd 439: ipstat.ips_tooshort++;
440: goto bad;
441: }
1.35 mycroft 442: if (m->m_pkthdr.len > len) {
1.1 cgd 443: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 444: m->m_len = len;
445: m->m_pkthdr.len = len;
1.1 cgd 446: } else
1.35 mycroft 447: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 448: }
449:
1.64 thorpej 450: /*
451: * Assume that we can create a fast-forward IP flow entry
452: * based on this packet.
453: */
454: m->m_flags |= M_CANFASTFWD;
455:
1.36 mrg 456: #ifdef PFIL_HOOKS
1.33 mrg 457: /*
1.64 thorpej 458: * Run through list of hooks for input packets. If there are any
459: * filters which require that additional packets in the flow are
460: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
461: * Note that filters must _never_ set this flag, as another filter
462: * in the list may have previously cleared it.
1.33 mrg 463: */
464: m0 = m;
1.59 mrg 465: for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33 mrg 466: if (pfh->pfil_func) {
1.43 mrg 467: rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
468: if (rv)
1.89 itojun 469: return;
1.68 sommerfe 470: m = m0;
471: if (m == NULL)
1.89 itojun 472: return;
1.68 sommerfe 473: ip = mtod(m, struct ip *);
1.33 mrg 474: }
1.36 mrg 475: #endif /* PFIL_HOOKS */
1.33 mrg 476:
1.1 cgd 477: /*
478: * Process options and, if not destined for us,
479: * ship it on. ip_dooptions returns 1 when an
480: * error was detected (causing an icmp message
481: * to be sent and the original packet to be freed).
482: */
483: ip_nhops = 0; /* for source routed packets */
484: if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.89 itojun 485: return;
1.1 cgd 486:
487: /*
488: * Check our list of addresses, to see if the packet is for us.
489: */
1.57 tls 490: INADDR_TO_IA(ip->ip_dst, ia);
1.86 thorpej 491: if (ia != NULL)
492: goto ours;
1.57 tls 493: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
494: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
495: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
496: if (ifa->ifa_addr->sa_family != AF_INET) continue;
497: ia = ifatoia(ifa);
1.35 mycroft 498: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
499: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 500: /*
501: * Look for all-0's host part (old broadcast addr),
502: * either for subnet or net.
503: */
504: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 505: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 506: goto ours;
1.57 tls 507: /*
508: * An interface with IP address zero accepts
509: * all packets that arrive on that interface.
510: */
511: if (in_nullhost(ia->ia_addr.sin_addr))
512: goto ours;
1.1 cgd 513: }
514: }
1.18 mycroft 515: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 516: struct in_multi *inm;
517: #ifdef MROUTING
518: extern struct socket *ip_mrouter;
1.10 brezak 519:
520: if (m->m_flags & M_EXT) {
521: if ((m = m_pullup(m, hlen)) == 0) {
522: ipstat.ips_toosmall++;
1.89 itojun 523: return;
1.10 brezak 524: }
525: ip = mtod(m, struct ip *);
526: }
1.4 hpeyerl 527:
528: if (ip_mrouter) {
529: /*
530: * If we are acting as a multicast router, all
531: * incoming multicast packets are passed to the
532: * kernel-level multicast forwarding function.
533: * The packet is returned (relatively) intact; if
534: * ip_mforward() returns a non-zero value, the packet
535: * must be discarded, else it may be accepted below.
536: *
537: * (The IP ident field is put in the same byte order
538: * as expected when ip_mforward() is called from
539: * ip_output().)
540: */
1.13 mycroft 541: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
542: ipstat.ips_cantforward++;
1.4 hpeyerl 543: m_freem(m);
1.89 itojun 544: return;
1.4 hpeyerl 545: }
546:
547: /*
548: * The process-level routing demon needs to receive
549: * all multicast IGMP packets, whether or not this
550: * host belongs to their destination groups.
551: */
552: if (ip->ip_p == IPPROTO_IGMP)
553: goto ours;
1.13 mycroft 554: ipstat.ips_forward++;
1.4 hpeyerl 555: }
556: #endif
557: /*
558: * See if we belong to the destination multicast group on the
559: * arrival interface.
560: */
561: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
562: if (inm == NULL) {
1.13 mycroft 563: ipstat.ips_cantforward++;
1.4 hpeyerl 564: m_freem(m);
1.89 itojun 565: return;
1.4 hpeyerl 566: }
567: goto ours;
568: }
1.19 mycroft 569: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 570: in_nullhost(ip->ip_dst))
1.1 cgd 571: goto ours;
572:
573: /*
574: * Not for us; forward if possible and desirable.
575: */
576: if (ipforwarding == 0) {
577: ipstat.ips_cantforward++;
578: m_freem(m);
579: } else
580: ip_forward(m, 0);
1.89 itojun 581: return;
1.1 cgd 582:
583: ours:
584: /*
585: * If offset or IP_MF are set, must reassemble.
586: * Otherwise, nothing need be done.
587: * (We could look in the reassembly queue to see
588: * if the packet was previously fragmented,
589: * but it's not worth the time; just let them time out.)
590: */
1.37 perry 591: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 592: /*
593: * Look for queue of fragments
594: * of this datagram.
595: */
1.75 thorpej 596: IPQ_LOCK();
1.25 cgd 597: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 598: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 599: in_hosteq(ip->ip_src, fp->ipq_src) &&
600: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 601: ip->ip_p == fp->ipq_p)
602: goto found;
603: fp = 0;
604: found:
605:
606: /*
607: * Adjust ip_len to not reflect header,
1.25 cgd 608: * set ipqe_mff if more fragments are expected,
1.1 cgd 609: * convert offset of this to bytes.
610: */
611: ip->ip_len -= hlen;
1.25 cgd 612: mff = (ip->ip_off & IP_MF) != 0;
613: if (mff) {
1.16 cgd 614: /*
615: * Make sure that fragments have a data length
616: * that's a non-zero multiple of 8 bytes.
617: */
1.17 cgd 618: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 619: ipstat.ips_badfrags++;
1.75 thorpej 620: IPQ_UNLOCK();
1.16 cgd 621: goto bad;
622: }
623: }
1.1 cgd 624: ip->ip_off <<= 3;
625:
626: /*
627: * If datagram marked as having more fragments
628: * or if this is not the first fragment,
629: * attempt reassembly; if it succeeds, proceed.
630: */
1.25 cgd 631: if (mff || ip->ip_off) {
1.1 cgd 632: ipstat.ips_fragments++;
1.72 thorpej 633: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 634: if (ipqe == NULL) {
635: ipstat.ips_rcvmemdrop++;
1.75 thorpej 636: IPQ_UNLOCK();
1.25 cgd 637: goto bad;
638: }
639: ipqe->ipqe_mff = mff;
1.50 thorpej 640: ipqe->ipqe_m = m;
1.25 cgd 641: ipqe->ipqe_ip = ip;
1.50 thorpej 642: m = ip_reass(ipqe, fp);
1.75 thorpej 643: if (m == 0) {
644: IPQ_UNLOCK();
1.89 itojun 645: return;
1.75 thorpej 646: }
1.13 mycroft 647: ipstat.ips_reassembled++;
1.50 thorpej 648: ip = mtod(m, struct ip *);
1.74 thorpej 649: hlen = ip->ip_hl << 2;
1.79 mycroft 650: ip->ip_len += hlen;
1.1 cgd 651: } else
652: if (fp)
653: ip_freef(fp);
1.75 thorpej 654: IPQ_UNLOCK();
1.79 mycroft 655: }
1.1 cgd 656:
657: /*
658: * Switch out to protocol's input routine.
659: */
1.82 aidan 660: #if IFA_STATS
661: ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
662: #endif
1.1 cgd 663: ipstat.ips_delivered++;
1.89 itojun 664: {
665: int off = hlen, nh = ip->ip_p;
666:
667: (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
668: return;
669: }
1.1 cgd 670: bad:
671: m_freem(m);
672: }
673:
674: /*
675: * Take incoming datagram fragment and try to
676: * reassemble it into whole datagram. If a chain for
677: * reassembly of this datagram already exists, then it
678: * is given as fp; otherwise have to make a chain.
679: */
1.50 thorpej 680: struct mbuf *
1.25 cgd 681: ip_reass(ipqe, fp)
682: register struct ipqent *ipqe;
1.1 cgd 683: register struct ipq *fp;
684: {
1.50 thorpej 685: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 686: register struct ipqent *nq, *p, *q;
687: struct ip *ip;
1.1 cgd 688: struct mbuf *t;
1.25 cgd 689: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 690: int i, next;
691:
1.75 thorpej 692: IPQ_LOCK_CHECK();
693:
1.1 cgd 694: /*
695: * Presence of header sizes in mbufs
696: * would confuse code below.
697: */
698: m->m_data += hlen;
699: m->m_len -= hlen;
700:
701: /*
702: * If first fragment to arrive, create a reassembly queue.
703: */
704: if (fp == 0) {
1.50 thorpej 705: MALLOC(fp, struct ipq *, sizeof (struct ipq),
706: M_FTABLE, M_NOWAIT);
707: if (fp == NULL)
1.1 cgd 708: goto dropfrag;
1.25 cgd 709: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 710: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 711: fp->ipq_p = ipqe->ipqe_ip->ip_p;
712: fp->ipq_id = ipqe->ipqe_ip->ip_id;
713: LIST_INIT(&fp->ipq_fragq);
714: fp->ipq_src = ipqe->ipqe_ip->ip_src;
715: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
716: p = NULL;
1.1 cgd 717: goto insert;
718: }
719:
720: /*
721: * Find a segment which begins after this one does.
722: */
1.25 cgd 723: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
724: p = q, q = q->ipqe_q.le_next)
725: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 726: break;
727:
728: /*
729: * If there is a preceding segment, it may provide some of
730: * our data already. If so, drop the data from the incoming
731: * segment. If it provides all of our data, drop us.
732: */
1.25 cgd 733: if (p != NULL) {
734: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
735: ipqe->ipqe_ip->ip_off;
1.1 cgd 736: if (i > 0) {
1.25 cgd 737: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 738: goto dropfrag;
1.50 thorpej 739: m_adj(ipqe->ipqe_m, i);
1.25 cgd 740: ipqe->ipqe_ip->ip_off += i;
741: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 742: }
743: }
744:
745: /*
746: * While we overlap succeeding segments trim them or,
747: * if they are completely covered, dequeue them.
748: */
1.25 cgd 749: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
750: q->ipqe_ip->ip_off; q = nq) {
751: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
752: q->ipqe_ip->ip_off;
753: if (i < q->ipqe_ip->ip_len) {
754: q->ipqe_ip->ip_len -= i;
755: q->ipqe_ip->ip_off += i;
1.50 thorpej 756: m_adj(q->ipqe_m, i);
1.1 cgd 757: break;
758: }
1.25 cgd 759: nq = q->ipqe_q.le_next;
1.50 thorpej 760: m_freem(q->ipqe_m);
1.25 cgd 761: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 762: pool_put(&ipqent_pool, q);
1.1 cgd 763: }
764:
765: insert:
766: /*
767: * Stick new segment in its place;
768: * check for complete reassembly.
769: */
1.25 cgd 770: if (p == NULL) {
771: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
772: } else {
773: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
774: }
1.1 cgd 775: next = 0;
1.25 cgd 776: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
777: p = q, q = q->ipqe_q.le_next) {
778: if (q->ipqe_ip->ip_off != next)
1.1 cgd 779: return (0);
1.25 cgd 780: next += q->ipqe_ip->ip_len;
1.1 cgd 781: }
1.25 cgd 782: if (p->ipqe_mff)
1.1 cgd 783: return (0);
784:
785: /*
1.41 thorpej 786: * Reassembly is complete. Check for a bogus message size and
787: * concatenate fragments.
1.1 cgd 788: */
1.25 cgd 789: q = fp->ipq_fragq.lh_first;
790: ip = q->ipqe_ip;
1.41 thorpej 791: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
792: ipstat.ips_toolong++;
793: ip_freef(fp);
794: return (0);
795: }
1.50 thorpej 796: m = q->ipqe_m;
1.1 cgd 797: t = m->m_next;
798: m->m_next = 0;
799: m_cat(m, t);
1.25 cgd 800: nq = q->ipqe_q.le_next;
1.72 thorpej 801: pool_put(&ipqent_pool, q);
1.25 cgd 802: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 803: t = q->ipqe_m;
1.25 cgd 804: nq = q->ipqe_q.le_next;
1.72 thorpej 805: pool_put(&ipqent_pool, q);
1.1 cgd 806: m_cat(m, t);
807: }
808:
809: /*
810: * Create header for new ip packet by
811: * modifying header of first packet;
812: * dequeue and discard fragment reassembly header.
813: * Make header visible.
814: */
815: ip->ip_len = next;
1.89 itojun 816: ip->ip_ttl = 0; /* xxx */
817: ip->ip_sum = 0;
1.25 cgd 818: ip->ip_src = fp->ipq_src;
819: ip->ip_dst = fp->ipq_dst;
820: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 821: FREE(fp, M_FTABLE);
1.1 cgd 822: m->m_len += (ip->ip_hl << 2);
823: m->m_data -= (ip->ip_hl << 2);
824: /* some debugging cruft by sklower, below, will go away soon */
825: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
826: register int plen = 0;
1.50 thorpej 827: for (t = m; t; t = t->m_next)
828: plen += t->m_len;
829: m->m_pkthdr.len = plen;
1.1 cgd 830: }
1.50 thorpej 831: return (m);
1.1 cgd 832:
833: dropfrag:
834: ipstat.ips_fragdropped++;
835: m_freem(m);
1.72 thorpej 836: pool_put(&ipqent_pool, ipqe);
1.1 cgd 837: return (0);
838: }
839:
840: /*
841: * Free a fragment reassembly header and all
842: * associated datagrams.
843: */
1.8 mycroft 844: void
1.1 cgd 845: ip_freef(fp)
846: struct ipq *fp;
847: {
1.25 cgd 848: register struct ipqent *q, *p;
1.1 cgd 849:
1.75 thorpej 850: IPQ_LOCK_CHECK();
851:
1.25 cgd 852: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
853: p = q->ipqe_q.le_next;
1.50 thorpej 854: m_freem(q->ipqe_m);
1.25 cgd 855: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 856: pool_put(&ipqent_pool, q);
1.1 cgd 857: }
1.25 cgd 858: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 859: FREE(fp, M_FTABLE);
1.1 cgd 860: }
861:
862: /*
863: * IP timer processing;
864: * if a timer expires on a reassembly
865: * queue, discard it.
866: */
1.8 mycroft 867: void
1.1 cgd 868: ip_slowtimo()
869: {
1.25 cgd 870: register struct ipq *fp, *nfp;
1.24 mycroft 871: int s = splsoftnet();
1.1 cgd 872:
1.75 thorpej 873: IPQ_LOCK();
1.25 cgd 874: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
875: nfp = fp->ipq_q.le_next;
876: if (--fp->ipq_ttl == 0) {
1.1 cgd 877: ipstat.ips_fragtimeout++;
1.25 cgd 878: ip_freef(fp);
1.1 cgd 879: }
880: }
1.75 thorpej 881: IPQ_UNLOCK();
1.63 matt 882: #ifdef GATEWAY
883: ipflow_slowtimo();
884: #endif
1.1 cgd 885: splx(s);
886: }
887:
888: /*
889: * Drain off all datagram fragments.
890: */
1.8 mycroft 891: void
1.1 cgd 892: ip_drain()
893: {
894:
1.75 thorpej 895: /*
896: * We may be called from a device's interrupt context. If
897: * the ipq is already busy, just bail out now.
898: */
899: if (ipq_lock_try() == 0)
900: return;
901:
1.25 cgd 902: while (ipq.lh_first != NULL) {
1.1 cgd 903: ipstat.ips_fragdropped++;
1.25 cgd 904: ip_freef(ipq.lh_first);
1.1 cgd 905: }
1.75 thorpej 906:
907: IPQ_UNLOCK();
1.1 cgd 908: }
909:
910: /*
911: * Do option processing on a datagram,
912: * possibly discarding it if bad options are encountered,
913: * or forwarding it if source-routed.
914: * Returns 1 if packet has been forwarded/freed,
915: * 0 if the packet should be processed further.
916: */
1.8 mycroft 917: int
1.1 cgd 918: ip_dooptions(m)
919: struct mbuf *m;
920: {
921: register struct ip *ip = mtod(m, struct ip *);
922: register u_char *cp;
923: register struct ip_timestamp *ipt;
924: register struct in_ifaddr *ia;
925: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13 mycroft 926: struct in_addr *sin, dst;
1.1 cgd 927: n_time ntime;
928:
1.13 mycroft 929: dst = ip->ip_dst;
1.1 cgd 930: cp = (u_char *)(ip + 1);
931: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
932: for (; cnt > 0; cnt -= optlen, cp += optlen) {
933: opt = cp[IPOPT_OPTVAL];
934: if (opt == IPOPT_EOL)
935: break;
936: if (opt == IPOPT_NOP)
937: optlen = 1;
938: else {
939: optlen = cp[IPOPT_OLEN];
940: if (optlen <= 0 || optlen > cnt) {
941: code = &cp[IPOPT_OLEN] - (u_char *)ip;
942: goto bad;
943: }
944: }
945: switch (opt) {
946:
947: default:
948: break;
949:
950: /*
951: * Source routing with record.
952: * Find interface with current destination address.
953: * If none on this machine then drop if strictly routed,
954: * or do nothing if loosely routed.
955: * Record interface address and bring up next address
956: * component. If strictly routed make sure next
957: * address is on directly accessible net.
958: */
959: case IPOPT_LSRR:
960: case IPOPT_SSRR:
1.47 cjs 961: if (ip_allowsrcrt == 0) {
962: type = ICMP_UNREACH;
963: code = ICMP_UNREACH_NET_PROHIB;
964: goto bad;
965: }
1.1 cgd 966: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
967: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
968: goto bad;
969: }
970: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 971: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 972: if (ia == 0) {
973: if (opt == IPOPT_SSRR) {
974: type = ICMP_UNREACH;
975: code = ICMP_UNREACH_SRCFAIL;
976: goto bad;
977: }
978: /*
979: * Loose routing, and not at next destination
980: * yet; nothing to do except forward.
981: */
982: break;
983: }
984: off--; /* 0 origin */
985: if (off > optlen - sizeof(struct in_addr)) {
986: /*
987: * End of source route. Should be for us.
988: */
989: save_rte(cp, ip->ip_src);
990: break;
991: }
992: /*
993: * locate outgoing interface
994: */
995: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
996: sizeof(ipaddr.sin_addr));
997: if (opt == IPOPT_SSRR) {
998: #define INA struct in_ifaddr *
999: #define SA struct sockaddr *
1.29 mrg 1000: ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1 cgd 1001: } else
1002: ia = ip_rtaddr(ipaddr.sin_addr);
1003: if (ia == 0) {
1004: type = ICMP_UNREACH;
1005: code = ICMP_UNREACH_SRCFAIL;
1006: goto bad;
1007: }
1008: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 1009: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1010: (caddr_t)(cp + off), sizeof(struct in_addr));
1011: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 1012: /*
1013: * Let ip_intr's mcast routing check handle mcast pkts
1014: */
1.18 mycroft 1015: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 1016: break;
1017:
1018: case IPOPT_RR:
1019: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1020: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1021: goto bad;
1022: }
1023: /*
1024: * If no space remains, ignore.
1025: */
1026: off--; /* 0 origin */
1027: if (off > optlen - sizeof(struct in_addr))
1028: break;
1029: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
1030: sizeof(ipaddr.sin_addr));
1031: /*
1032: * locate outgoing interface; if we're the destination,
1033: * use the incoming interface (should be same).
1034: */
1035: if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1036: (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1037: type = ICMP_UNREACH;
1038: code = ICMP_UNREACH_HOST;
1039: goto bad;
1040: }
1.20 mycroft 1041: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1042: (caddr_t)(cp + off), sizeof(struct in_addr));
1043: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1044: break;
1045:
1046: case IPOPT_TS:
1047: code = cp - (u_char *)ip;
1048: ipt = (struct ip_timestamp *)cp;
1049: if (ipt->ipt_len < 5)
1050: goto bad;
1.15 cgd 1051: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 1052: if (++ipt->ipt_oflw == 0)
1053: goto bad;
1054: break;
1055: }
1056: sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
1057: switch (ipt->ipt_flg) {
1058:
1059: case IPOPT_TS_TSONLY:
1060: break;
1061:
1062: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1063: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1064: sizeof(struct in_addr) > ipt->ipt_len)
1065: goto bad;
1.13 mycroft 1066: ipaddr.sin_addr = dst;
1067: ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1068: m->m_pkthdr.rcvif);
1069: if (ia == 0)
1070: continue;
1.20 mycroft 1071: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1072: (caddr_t)sin, sizeof(struct in_addr));
1073: ipt->ipt_ptr += sizeof(struct in_addr);
1074: break;
1075:
1076: case IPOPT_TS_PRESPEC:
1.66 thorpej 1077: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1078: sizeof(struct in_addr) > ipt->ipt_len)
1079: goto bad;
1080: bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
1081: sizeof(struct in_addr));
1082: if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1083: continue;
1084: ipt->ipt_ptr += sizeof(struct in_addr);
1085: break;
1086:
1087: default:
1088: goto bad;
1089: }
1090: ntime = iptime();
1091: bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
1092: sizeof(n_time));
1093: ipt->ipt_ptr += sizeof(n_time);
1094: }
1095: }
1096: if (forward) {
1.26 thorpej 1097: if (ip_forwsrcrt == 0) {
1098: type = ICMP_UNREACH;
1099: code = ICMP_UNREACH_SRCFAIL;
1100: goto bad;
1101: }
1.1 cgd 1102: ip_forward(m, 1);
1103: return (1);
1.13 mycroft 1104: }
1105: return (0);
1.1 cgd 1106: bad:
1.13 mycroft 1107: icmp_error(m, type, code, 0, 0);
1108: ipstat.ips_badoptions++;
1.1 cgd 1109: return (1);
1110: }
1111:
1112: /*
1113: * Given address of next destination (final or next hop),
1114: * return internet address info of interface to be used to get there.
1115: */
1116: struct in_ifaddr *
1117: ip_rtaddr(dst)
1118: struct in_addr dst;
1119: {
1120: register struct sockaddr_in *sin;
1121:
1.19 mycroft 1122: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1123:
1.35 mycroft 1124: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1125: if (ipforward_rt.ro_rt) {
1126: RTFREE(ipforward_rt.ro_rt);
1127: ipforward_rt.ro_rt = 0;
1128: }
1129: sin->sin_family = AF_INET;
1130: sin->sin_len = sizeof(*sin);
1131: sin->sin_addr = dst;
1132:
1133: rtalloc(&ipforward_rt);
1134: }
1135: if (ipforward_rt.ro_rt == 0)
1136: return ((struct in_ifaddr *)0);
1.19 mycroft 1137: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1138: }
1139:
1140: /*
1141: * Save incoming source route for use in replies,
1142: * to be picked up later by ip_srcroute if the receiver is interested.
1143: */
1.13 mycroft 1144: void
1.1 cgd 1145: save_rte(option, dst)
1146: u_char *option;
1147: struct in_addr dst;
1148: {
1149: unsigned olen;
1150:
1151: olen = option[IPOPT_OLEN];
1152: #ifdef DIAGNOSTIC
1153: if (ipprintfs)
1.39 christos 1154: printf("save_rte: olen %d\n", olen);
1.89 itojun 1155: #endif /* 0 */
1.1 cgd 1156: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1157: return;
1158: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1159: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1160: ip_srcrt.dst = dst;
1161: }
1162:
1163: /*
1164: * Retrieve incoming source route for use in replies,
1165: * in the same form used by setsockopt.
1166: * The first hop is placed before the options, will be removed later.
1167: */
1168: struct mbuf *
1169: ip_srcroute()
1170: {
1171: register struct in_addr *p, *q;
1172: register struct mbuf *m;
1173:
1174: if (ip_nhops == 0)
1175: return ((struct mbuf *)0);
1176: m = m_get(M_DONTWAIT, MT_SOOPTS);
1177: if (m == 0)
1178: return ((struct mbuf *)0);
1179:
1.13 mycroft 1180: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1181:
1182: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1183: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1184: OPTSIZ;
1185: #ifdef DIAGNOSTIC
1186: if (ipprintfs)
1.39 christos 1187: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1188: #endif
1189:
1190: /*
1191: * First save first hop for return route
1192: */
1193: p = &ip_srcrt.route[ip_nhops - 1];
1194: *(mtod(m, struct in_addr *)) = *p--;
1195: #ifdef DIAGNOSTIC
1196: if (ipprintfs)
1.39 christos 1197: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1198: #endif
1199:
1200: /*
1201: * Copy option fields and padding (nop) to mbuf.
1202: */
1203: ip_srcrt.nop = IPOPT_NOP;
1204: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1205: bcopy((caddr_t)&ip_srcrt.nop,
1206: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1207: q = (struct in_addr *)(mtod(m, caddr_t) +
1208: sizeof(struct in_addr) + OPTSIZ);
1209: #undef OPTSIZ
1210: /*
1211: * Record return path as an IP source route,
1212: * reversing the path (pointers are now aligned).
1213: */
1214: while (p >= ip_srcrt.route) {
1215: #ifdef DIAGNOSTIC
1216: if (ipprintfs)
1.39 christos 1217: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1218: #endif
1219: *q++ = *p--;
1220: }
1221: /*
1222: * Last hop goes to final destination.
1223: */
1224: *q = ip_srcrt.dst;
1225: #ifdef DIAGNOSTIC
1226: if (ipprintfs)
1.39 christos 1227: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1228: #endif
1229: return (m);
1230: }
1231:
1232: /*
1233: * Strip out IP options, at higher
1234: * level protocol in the kernel.
1235: * Second argument is buffer to which options
1236: * will be moved, and return value is their length.
1237: * XXX should be deleted; last arg currently ignored.
1238: */
1.8 mycroft 1239: void
1.1 cgd 1240: ip_stripoptions(m, mopt)
1241: register struct mbuf *m;
1242: struct mbuf *mopt;
1243: {
1244: register int i;
1245: struct ip *ip = mtod(m, struct ip *);
1246: register caddr_t opts;
1247: int olen;
1248:
1.79 mycroft 1249: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1250: opts = (caddr_t)(ip + 1);
1251: i = m->m_len - (sizeof (struct ip) + olen);
1252: bcopy(opts + olen, opts, (unsigned)i);
1253: m->m_len -= olen;
1254: if (m->m_flags & M_PKTHDR)
1255: m->m_pkthdr.len -= olen;
1.79 mycroft 1256: ip->ip_len -= olen;
1257: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1258: }
1259:
1.23 mycroft 1260: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1261: 0, 0, 0, 0,
1262: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1263: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1264: EMSGSIZE, EHOSTUNREACH, 0, 0,
1265: 0, 0, 0, 0,
1266: ENOPROTOOPT
1267: };
1268:
1269: /*
1270: * Forward a packet. If some error occurs return the sender
1271: * an icmp packet. Note we can't always generate a meaningful
1272: * icmp message because icmp doesn't have a large enough repertoire
1273: * of codes and types.
1274: *
1275: * If not forwarding, just drop the packet. This could be confusing
1276: * if ipforwarding was zero but some routing protocol was advancing
1277: * us as a gateway to somewhere. However, we must let the routing
1278: * protocol deal with that.
1279: *
1280: * The srcrt parameter indicates whether the packet is being forwarded
1281: * via a source route.
1282: */
1.13 mycroft 1283: void
1.1 cgd 1284: ip_forward(m, srcrt)
1285: struct mbuf *m;
1286: int srcrt;
1287: {
1288: register struct ip *ip = mtod(m, struct ip *);
1289: register struct sockaddr_in *sin;
1290: register struct rtentry *rt;
1.28 christos 1291: int error, type = 0, code = 0;
1.1 cgd 1292: struct mbuf *mcopy;
1.13 mycroft 1293: n_long dest;
1294: struct ifnet *destifp;
1.89 itojun 1295: #ifdef IPSEC
1296: struct ifnet dummyifp;
1297: #endif
1.1 cgd 1298:
1.13 mycroft 1299: dest = 0;
1.1 cgd 1300: #ifdef DIAGNOSTIC
1301: if (ipprintfs)
1.70 thorpej 1302: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1303: ntohl(ip->ip_src.s_addr),
1304: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1305: #endif
1306: if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
1307: ipstat.ips_cantforward++;
1308: m_freem(m);
1309: return;
1310: }
1311: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1312: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1313: return;
1314: }
1315: ip->ip_ttl -= IPTTLDEC;
1316:
1.19 mycroft 1317: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1318: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1319: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1320: if (ipforward_rt.ro_rt) {
1321: RTFREE(ipforward_rt.ro_rt);
1322: ipforward_rt.ro_rt = 0;
1323: }
1324: sin->sin_family = AF_INET;
1.35 mycroft 1325: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1326: sin->sin_addr = ip->ip_dst;
1327:
1328: rtalloc(&ipforward_rt);
1329: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1330: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1331: return;
1332: }
1333: rt = ipforward_rt.ro_rt;
1334: }
1335:
1336: /*
1.34 mycroft 1337: * Save at most 68 bytes of the packet in case
1.1 cgd 1338: * we need to generate an ICMP message to the src.
1339: */
1.34 mycroft 1340: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1341:
1342: /*
1343: * If forwarding packet using same interface that it came in on,
1344: * perhaps should send a redirect to sender to shortcut a hop.
1345: * Only send redirect if source is sending directly to us,
1346: * and if packet was not source routed (or has any options).
1347: * Also, don't send redirect if forwarding using a default route
1348: * or a route modified by a redirect.
1349: */
1350: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1351: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1352: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1353: ipsendredirects && !srcrt) {
1.19 mycroft 1354: if (rt->rt_ifa &&
1355: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1356: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1357: if (rt->rt_flags & RTF_GATEWAY)
1358: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1359: else
1360: dest = ip->ip_dst.s_addr;
1361: /*
1362: * Router requirements says to only send host
1363: * redirects.
1364: */
1365: type = ICMP_REDIRECT;
1366: code = ICMP_REDIRECT_HOST;
1.1 cgd 1367: #ifdef DIAGNOSTIC
1.77 thorpej 1368: if (ipprintfs)
1369: printf("redirect (%d) to %x\n", code,
1370: (u_int32_t)dest);
1.1 cgd 1371: #endif
1372: }
1373: }
1374:
1.89 itojun 1375: #ifdef IPSEC
1376: m->m_pkthdr.rcvif = NULL;
1377: #endif /*IPSEC*/
1.27 thorpej 1378: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1379: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1380: if (error)
1381: ipstat.ips_cantforward++;
1382: else {
1383: ipstat.ips_forward++;
1384: if (type)
1385: ipstat.ips_redirectsent++;
1386: else {
1.63 matt 1387: if (mcopy) {
1388: #ifdef GATEWAY
1.64 thorpej 1389: if (mcopy->m_flags & M_CANFASTFWD)
1390: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1391: #endif
1.1 cgd 1392: m_freem(mcopy);
1.63 matt 1393: }
1.1 cgd 1394: return;
1395: }
1396: }
1397: if (mcopy == NULL)
1398: return;
1.13 mycroft 1399: destifp = NULL;
1400:
1.1 cgd 1401: switch (error) {
1402:
1403: case 0: /* forwarded, but need redirect */
1404: /* type, code set above */
1405: break;
1406:
1407: case ENETUNREACH: /* shouldn't happen, checked above */
1408: case EHOSTUNREACH:
1409: case ENETDOWN:
1410: case EHOSTDOWN:
1411: default:
1412: type = ICMP_UNREACH;
1413: code = ICMP_UNREACH_HOST;
1414: break;
1415:
1416: case EMSGSIZE:
1417: type = ICMP_UNREACH;
1418: code = ICMP_UNREACH_NEEDFRAG;
1.89 itojun 1419: #ifndef IPSEC
1.13 mycroft 1420: if (ipforward_rt.ro_rt)
1421: destifp = ipforward_rt.ro_rt->rt_ifp;
1.89 itojun 1422: #else
1423: /*
1424: * If the packet is routed over IPsec tunnel, tell the
1425: * originator the tunnel MTU.
1426: * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1427: * XXX quickhack!!!
1428: */
1429: if (ipforward_rt.ro_rt) {
1430: struct secpolicy *sp;
1431: int ipsecerror;
1432: int ipsechdr;
1433: struct route *ro;
1434:
1435: sp = ipsec4_getpolicybyaddr(mcopy,
1436: IP_FORWARDING,
1437: &ipsecerror);
1438:
1439: if (sp == NULL)
1440: destifp = ipforward_rt.ro_rt->rt_ifp;
1441: else {
1442: /* count IPsec header size */
1443: ipsechdr = ipsec4_hdrsiz(mcopy, NULL);
1444:
1445: /*
1446: * find the correct route for outer IPv4
1447: * header, compute tunnel MTU.
1448: *
1449: * XXX BUG ALERT
1450: * The "dummyifp" code relies upon the fact
1451: * that icmp_error() touches only ifp->if_mtu.
1452: */
1453: /*XXX*/
1454: destifp = NULL;
1455: if (sp->req != NULL
1456: && sp->req->sa != NULL) {
1457: ro = &sp->req->sa->saidx->sa_route;
1458: if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1459: dummyifp.if_mtu =
1460: ro->ro_rt->rt_ifp->if_mtu;
1461: dummyifp.if_mtu -= ipsechdr;
1462: destifp = &dummyifp;
1463: }
1464: }
1465:
1466: key_freesp(sp);
1467: }
1468: }
1469: #endif /*IPSEC*/
1.1 cgd 1470: ipstat.ips_cantfrag++;
1471: break;
1472:
1473: case ENOBUFS:
1474: type = ICMP_SOURCEQUENCH;
1475: code = 0;
1476: break;
1477: }
1.13 mycroft 1478: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1479: }
1480:
1481: void
1482: ip_savecontrol(inp, mp, ip, m)
1483: register struct inpcb *inp;
1484: register struct mbuf **mp;
1485: register struct ip *ip;
1486: register struct mbuf *m;
1487: {
1488:
1489: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1490: struct timeval tv;
1491:
1492: microtime(&tv);
1493: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1494: SCM_TIMESTAMP, SOL_SOCKET);
1495: if (*mp)
1496: mp = &(*mp)->m_next;
1497: }
1498: if (inp->inp_flags & INP_RECVDSTADDR) {
1499: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1500: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1501: if (*mp)
1502: mp = &(*mp)->m_next;
1503: }
1504: #ifdef notyet
1505: /*
1506: * XXX
1507: * Moving these out of udp_input() made them even more broken
1508: * than they already were.
1509: * - fenner@parc.xerox.com
1510: */
1511: /* options were tossed already */
1512: if (inp->inp_flags & INP_RECVOPTS) {
1513: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1514: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1515: if (*mp)
1516: mp = &(*mp)->m_next;
1517: }
1518: /* ip_srcroute doesn't do what we want here, need to fix */
1519: if (inp->inp_flags & INP_RECVRETOPTS) {
1520: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1521: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1522: if (*mp)
1523: mp = &(*mp)->m_next;
1524: }
1525: #endif
1526: if (inp->inp_flags & INP_RECVIF) {
1527: struct sockaddr_dl sdl;
1528:
1529: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1530: sdl.sdl_family = AF_LINK;
1531: sdl.sdl_index = m->m_pkthdr.rcvif ?
1532: m->m_pkthdr.rcvif->if_index : 0;
1533: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1534: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1535: IP_RECVIF, IPPROTO_IP);
1536: if (*mp)
1537: mp = &(*mp)->m_next;
1538: }
1.13 mycroft 1539: }
1540:
1541: int
1542: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1543: int *name;
1544: u_int namelen;
1545: void *oldp;
1546: size_t *oldlenp;
1547: void *newp;
1548: size_t newlen;
1549: {
1.88 sommerfe 1550: extern int subnetsarelocal, hostzeroisbroadcast;
1.52 thorpej 1551:
1.54 lukem 1552: int error, old;
1553:
1.13 mycroft 1554: /* All sysctl names at this level are terminal. */
1555: if (namelen != 1)
1556: return (ENOTDIR);
1557:
1558: switch (name[0]) {
1559: case IPCTL_FORWARDING:
1560: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1561: case IPCTL_SENDREDIRECTS:
1562: return (sysctl_int(oldp, oldlenp, newp, newlen,
1563: &ipsendredirects));
1564: case IPCTL_DEFTTL:
1565: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1566: #ifdef notyet
1567: case IPCTL_DEFMTU:
1568: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1569: #endif
1.26 thorpej 1570: case IPCTL_FORWSRCRT:
1.47 cjs 1571: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1572: if (securelevel > 0)
1.46 cjs 1573: return (sysctl_rdint(oldp, oldlenp, newp,
1574: ip_forwsrcrt));
1575: else
1576: return (sysctl_int(oldp, oldlenp, newp, newlen,
1577: &ip_forwsrcrt));
1.27 thorpej 1578: case IPCTL_DIRECTEDBCAST:
1579: return (sysctl_int(oldp, oldlenp, newp, newlen,
1580: &ip_directedbcast));
1.47 cjs 1581: case IPCTL_ALLOWSRCRT:
1582: return (sysctl_int(oldp, oldlenp, newp, newlen,
1583: &ip_allowsrcrt));
1.52 thorpej 1584: case IPCTL_SUBNETSARELOCAL:
1585: return (sysctl_int(oldp, oldlenp, newp, newlen,
1586: &subnetsarelocal));
1.53 kml 1587: case IPCTL_MTUDISC:
1.60 kml 1588: error = sysctl_int(oldp, oldlenp, newp, newlen,
1589: &ip_mtudisc);
1590: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1591: ip_mtudisc_timeout_q =
1592: rt_timer_queue_create(ip_mtudisc_timeout);
1593: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1594: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1595: ip_mtudisc_timeout_q = NULL;
1596: }
1597: return error;
1.54 lukem 1598: case IPCTL_ANONPORTMIN:
1599: old = anonportmin;
1600: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1601: if (anonportmin >= anonportmax || anonportmin > 65535
1602: #ifndef IPNOPRIVPORTS
1603: || anonportmin < IPPORT_RESERVED
1604: #endif
1605: ) {
1606: anonportmin = old;
1607: return (EINVAL);
1608: }
1609: return (error);
1610: case IPCTL_ANONPORTMAX:
1611: old = anonportmax;
1612: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1613: if (anonportmin >= anonportmax || anonportmax > 65535
1614: #ifndef IPNOPRIVPORTS
1615: || anonportmax < IPPORT_RESERVED
1616: #endif
1617: ) {
1618: anonportmax = old;
1619: return (EINVAL);
1620: }
1.60 kml 1621: return (error);
1622: case IPCTL_MTUDISCTIMEOUT:
1623: error = sysctl_int(oldp, oldlenp, newp, newlen,
1624: &ip_mtudisc_timeout);
1625: if (ip_mtudisc_timeout_q != NULL)
1626: rt_timer_queue_change(ip_mtudisc_timeout_q,
1627: ip_mtudisc_timeout);
1.54 lukem 1628: return (error);
1.65 matt 1629: #ifdef GATEWAY
1630: case IPCTL_MAXFLOWS:
1.67 thorpej 1631: {
1632: int s;
1633:
1.65 matt 1634: error = sysctl_int(oldp, oldlenp, newp, newlen,
1635: &ip_maxflows);
1.67 thorpej 1636: s = splsoftnet();
1.65 matt 1637: ipflow_reap(0);
1.67 thorpej 1638: splx(s);
1.65 matt 1639: return (error);
1.67 thorpej 1640: }
1.89 itojun 1641: #endif
1.90 itojun 1642: case IPCTL_HOSTZEROBROADCAST:
1643: return (sysctl_int(oldp, oldlenp, newp, newlen,
1644: &hostzeroisbroadcast));
1.89 itojun 1645: #if NGIF > 0
1646: case IPCTL_GIF_TTL:
1647: return(sysctl_int(oldp, oldlenp, newp, newlen,
1.90 itojun 1648: &ip_gif_ttl));
1.65 matt 1649: #endif
1.88 sommerfe 1650:
1.13 mycroft 1651: default:
1652: return (EOPNOTSUPP);
1653: }
1654: /* NOTREACHED */
1.1 cgd 1655: }
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