Annotation of src/sys/netinet/ip_input.c, Revision 1.82.2.2.2.2
1.82.2.2.2.2! thorpej 1: /* $NetBSD: ip_input.c,v 1.82.2.2.2.1 1999/06/21 01:27:49 thorpej Exp $ */
! 2:
! 3: /*
! 4: * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
! 5: * All rights reserved.
! 6: *
! 7: * Redistribution and use in source and binary forms, with or without
! 8: * modification, are permitted provided that the following conditions
! 9: * are met:
! 10: * 1. Redistributions of source code must retain the above copyright
! 11: * notice, this list of conditions and the following disclaimer.
! 12: * 2. Redistributions in binary form must reproduce the above copyright
! 13: * notice, this list of conditions and the following disclaimer in the
! 14: * documentation and/or other materials provided with the distribution.
! 15: * 3. Neither the name of the project nor the names of its contributors
! 16: * may be used to endorse or promote products derived from this software
! 17: * without specific prior written permission.
! 18: *
! 19: * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
! 20: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 21: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 22: * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
! 23: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 24: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 25: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 26: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 27: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 28: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 29: * SUCH DAMAGE.
! 30: */
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"
1.55 scottr 106: #include "opt_mrouting.h"
1.1 cgd 107:
1.5 mycroft 108: #include <sys/param.h>
109: #include <sys/systm.h>
110: #include <sys/malloc.h>
111: #include <sys/mbuf.h>
112: #include <sys/domain.h>
113: #include <sys/protosw.h>
114: #include <sys/socket.h>
1.44 thorpej 115: #include <sys/socketvar.h>
1.5 mycroft 116: #include <sys/errno.h>
117: #include <sys/time.h>
118: #include <sys/kernel.h>
1.28 christos 119: #include <sys/proc.h>
1.72 thorpej 120: #include <sys/pool.h>
1.28 christos 121:
122: #include <vm/vm.h>
123: #include <sys/sysctl.h>
1.1 cgd 124:
1.5 mycroft 125: #include <net/if.h>
1.44 thorpej 126: #include <net/if_dl.h>
1.5 mycroft 127: #include <net/route.h>
1.45 mrg 128: #include <net/pfil.h>
1.1 cgd 129:
1.5 mycroft 130: #include <netinet/in.h>
131: #include <netinet/in_systm.h>
132: #include <netinet/ip.h>
133: #include <netinet/in_pcb.h>
134: #include <netinet/in_var.h>
135: #include <netinet/ip_var.h>
136: #include <netinet/ip_icmp.h>
1.82.2.2.2.2! thorpej 137: /* just for gif_ttl */
! 138: #include <netinet/in_gif.h>
! 139: #include "gif.h"
! 140:
! 141: #ifdef IPSEC
! 142: #include <netinet6/ipsec.h>
! 143: #include <netinet6/ah.h>
! 144: #ifdef IPSEC_ESP
! 145: #include <netinet6/esp.h>
! 146: #endif
! 147: #include <netkey/key.h>
! 148: #include <netkey/key_debug.h>
! 149: #endif
1.44 thorpej 150:
1.1 cgd 151: #ifndef IPFORWARDING
152: #ifdef GATEWAY
153: #define IPFORWARDING 1 /* forward IP packets not for us */
154: #else /* GATEWAY */
155: #define IPFORWARDING 0 /* don't forward IP packets not for us */
156: #endif /* GATEWAY */
157: #endif /* IPFORWARDING */
158: #ifndef IPSENDREDIRECTS
159: #define IPSENDREDIRECTS 1
160: #endif
1.26 thorpej 161: #ifndef IPFORWSRCRT
1.47 cjs 162: #define IPFORWSRCRT 1 /* forward source-routed packets */
163: #endif
164: #ifndef IPALLOWSRCRT
1.48 mrg 165: #define IPALLOWSRCRT 1 /* allow source-routed packets */
1.26 thorpej 166: #endif
1.53 kml 167: #ifndef IPMTUDISC
168: #define IPMTUDISC 0
169: #endif
1.60 kml 170: #ifndef IPMTUDISCTIMEOUT
1.61 kml 171: #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
1.60 kml 172: #endif
1.53 kml 173:
1.27 thorpej 174: /*
175: * Note: DIRECTED_BROADCAST is handled this way so that previous
176: * configuration using this option will Just Work.
177: */
178: #ifndef IPDIRECTEDBCAST
179: #ifdef DIRECTED_BROADCAST
180: #define IPDIRECTEDBCAST 1
181: #else
182: #define IPDIRECTEDBCAST 0
183: #endif /* DIRECTED_BROADCAST */
184: #endif /* IPDIRECTEDBCAST */
1.1 cgd 185: int ipforwarding = IPFORWARDING;
186: int ipsendredirects = IPSENDREDIRECTS;
1.13 mycroft 187: int ip_defttl = IPDEFTTL;
1.26 thorpej 188: int ip_forwsrcrt = IPFORWSRCRT;
1.27 thorpej 189: int ip_directedbcast = IPDIRECTEDBCAST;
1.47 cjs 190: int ip_allowsrcrt = IPALLOWSRCRT;
1.53 kml 191: int ip_mtudisc = IPMTUDISC;
1.60 kml 192: u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1 cgd 193: #ifdef DIAGNOSTIC
194: int ipprintfs = 0;
195: #endif
196:
1.60 kml 197: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
198:
1.1 cgd 199: extern struct domain inetdomain;
200: extern struct protosw inetsw[];
201: u_char ip_protox[IPPROTO_MAX];
202: int ipqmaxlen = IFQ_MAXLEN;
1.22 mycroft 203: struct in_ifaddrhead in_ifaddr;
1.57 tls 204: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.13 mycroft 205: struct ifqueue ipintrq;
1.63 matt 206: struct ipstat ipstat;
207: u_int16_t ip_id;
208: int ip_defttl;
1.75 thorpej 209:
1.63 matt 210: struct ipqhead ipq;
1.75 thorpej 211: int ipq_locked;
212:
213: static __inline int ipq_lock_try __P((void));
214: static __inline void ipq_unlock __P((void));
215:
216: static __inline int
217: ipq_lock_try()
218: {
219: int s;
220:
221: s = splimp();
222: if (ipq_locked) {
223: splx(s);
224: return (0);
225: }
226: ipq_locked = 1;
227: splx(s);
228: return (1);
229: }
230:
231: static __inline void
232: ipq_unlock()
233: {
234: int s;
235:
236: s = splimp();
237: ipq_locked = 0;
238: splx(s);
239: }
240:
241: #ifdef DIAGNOSTIC
242: #define IPQ_LOCK() \
243: do { \
244: if (ipq_lock_try() == 0) { \
245: printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
246: panic("ipq_lock"); \
247: } \
248: } while (0)
249: #define IPQ_LOCK_CHECK() \
250: do { \
251: if (ipq_locked == 0) { \
252: printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
253: panic("ipq lock check"); \
254: } \
255: } while (0)
256: #else
257: #define IPQ_LOCK() (void) ipq_lock_try()
258: #define IPQ_LOCK_CHECK() /* nothing */
259: #endif
260:
261: #define IPQ_UNLOCK() ipq_unlock()
1.1 cgd 262:
1.72 thorpej 263: struct pool ipqent_pool;
264:
1.1 cgd 265: /*
266: * We need to save the IP options in case a protocol wants to respond
267: * to an incoming packet over the same route if the packet got here
268: * using IP source routing. This allows connection establishment and
269: * maintenance when the remote end is on a network that is not known
270: * to us.
271: */
272: int ip_nhops = 0;
273: static struct ip_srcrt {
274: struct in_addr dst; /* final destination */
275: char nop; /* one NOP to align */
276: char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
277: struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
278: } ip_srcrt;
279:
1.13 mycroft 280: static void save_rte __P((u_char *, struct in_addr));
1.35 mycroft 281:
1.1 cgd 282: /*
283: * IP initialization: fill in IP protocol switch table.
284: * All protocols not implemented in kernel go to raw IP protocol handler.
285: */
1.8 mycroft 286: void
1.1 cgd 287: ip_init()
288: {
289: register struct protosw *pr;
290: register int i;
291:
1.72 thorpej 292: pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
293: 0, NULL, NULL, M_IPQ);
294:
1.1 cgd 295: pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
296: if (pr == 0)
297: panic("ip_init");
298: for (i = 0; i < IPPROTO_MAX; i++)
299: ip_protox[i] = pr - inetsw;
300: for (pr = inetdomain.dom_protosw;
301: pr < inetdomain.dom_protoswNPROTOSW; pr++)
302: if (pr->pr_domain->dom_family == PF_INET &&
303: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
304: ip_protox[pr->pr_protocol] = pr - inetsw;
1.25 cgd 305: LIST_INIT(&ipq);
1.1 cgd 306: ip_id = time.tv_sec & 0xffff;
307: ipintrq.ifq_maxlen = ipqmaxlen;
1.22 mycroft 308: TAILQ_INIT(&in_ifaddr);
1.57 tls 309: in_ifaddrhashtbl =
310: hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash);
1.60 kml 311: if (ip_mtudisc != 0)
312: ip_mtudisc_timeout_q =
313: rt_timer_queue_create(ip_mtudisc_timeout);
1.73 thorpej 314: #ifdef GATEWAY
315: ipflow_init();
316: #endif
1.1 cgd 317: }
318:
319: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
320: struct route ipforward_rt;
321:
322: /*
1.82.2.2.2.2! thorpej 323: * IP software interrupt routine
! 324: */
! 325: void
! 326: ipintr()
! 327: {
! 328: int s;
! 329: struct mbuf *m;
! 330:
! 331: while (1) {
! 332: s = splimp();
! 333: IF_DEQUEUE(&ipintrq, m);
! 334: splx(s);
! 335: if (m == 0)
! 336: return;
! 337: ip_input(m);
! 338: }
! 339: }
! 340:
! 341: /*
1.1 cgd 342: * Ip input routine. Checksum and byte swap header. If fragmented
343: * try to reassemble. Process options. Pass to next level.
344: */
1.8 mycroft 345: void
1.82.2.2.2.2! thorpej 346: ip_input(struct mbuf *m)
1.1 cgd 347: {
1.33 mrg 348: register struct ip *ip = NULL;
1.1 cgd 349: register struct ipq *fp;
350: register struct in_ifaddr *ia;
1.57 tls 351: register struct ifaddr *ifa;
1.25 cgd 352: struct ipqent *ipqe;
1.82.2.2.2.2! thorpej 353: int hlen = 0, mff, len;
1.36 mrg 354: #ifdef PFIL_HOOKS
1.33 mrg 355: struct packet_filter_hook *pfh;
356: struct mbuf *m0;
1.43 mrg 357: int rv;
1.36 mrg 358: #endif /* PFIL_HOOKS */
1.1 cgd 359:
360: #ifdef DIAGNOSTIC
361: if ((m->m_flags & M_PKTHDR) == 0)
362: panic("ipintr no HDR");
363: #endif
1.82.2.2.2.2! thorpej 364: #ifdef IPSEC
! 365: /*
! 366: * should the inner packet be considered authentic?
! 367: * see comment in ah4_input().
! 368: */
! 369: if (m) {
! 370: m->m_flags &= ~M_AUTHIPHDR;
! 371: m->m_flags &= ~M_AUTHIPDGM;
! 372: }
! 373: #endif
1.1 cgd 374: /*
375: * If no IP addresses have been set yet but the interfaces
376: * are receiving, can't do anything with incoming packets yet.
377: */
1.22 mycroft 378: if (in_ifaddr.tqh_first == 0)
1.1 cgd 379: goto bad;
380: ipstat.ips_total++;
381: if (m->m_len < sizeof (struct ip) &&
382: (m = m_pullup(m, sizeof (struct ip))) == 0) {
383: ipstat.ips_toosmall++;
1.82.2.2.2.2! thorpej 384: return;
1.1 cgd 385: }
386: ip = mtod(m, struct ip *);
1.13 mycroft 387: if (ip->ip_v != IPVERSION) {
388: ipstat.ips_badvers++;
389: goto bad;
390: }
1.1 cgd 391: hlen = ip->ip_hl << 2;
392: if (hlen < sizeof(struct ip)) { /* minimum header length */
393: ipstat.ips_badhlen++;
394: goto bad;
395: }
396: if (hlen > m->m_len) {
397: if ((m = m_pullup(m, hlen)) == 0) {
398: ipstat.ips_badhlen++;
1.82.2.2.2.2! thorpej 399: return;
1.1 cgd 400: }
401: ip = mtod(m, struct ip *);
402: }
1.82.2.2.2.1 thorpej 403: /*
404: * we drop packets that have a multicast address as source
405: * as wanted by rfc 1112
406: */
407: if (IN_MULTICAST(ip->ip_src.s_addr)) {
408: goto bad;
409: }
410:
1.78 mycroft 411: if (in_cksum(m, hlen) != 0) {
1.1 cgd 412: ipstat.ips_badsum++;
413: goto bad;
414: }
415:
416: /*
417: * Convert fields to host representation.
418: */
419: NTOHS(ip->ip_len);
420: NTOHS(ip->ip_off);
1.35 mycroft 421: len = ip->ip_len;
1.81 proff 422:
423: /*
424: * Check for additional length bogosity
425: */
1.82.2.2.2.1 thorpej 426: if (len < hlen) {
1.81 proff 427: ipstat.ips_badlen++;
428: goto bad;
429: }
1.1 cgd 430:
431: /*
432: * Check that the amount of data in the buffers
433: * is as at least much as the IP header would have us expect.
434: * Trim mbufs if longer than we expect.
435: * Drop packet if shorter than we expect.
436: */
1.35 mycroft 437: if (m->m_pkthdr.len < len) {
1.1 cgd 438: ipstat.ips_tooshort++;
439: goto bad;
440: }
1.35 mycroft 441: if (m->m_pkthdr.len > len) {
1.1 cgd 442: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 443: m->m_len = len;
444: m->m_pkthdr.len = len;
1.1 cgd 445: } else
1.35 mycroft 446: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 447: }
448:
1.64 thorpej 449: /*
450: * Assume that we can create a fast-forward IP flow entry
451: * based on this packet.
452: */
453: m->m_flags |= M_CANFASTFWD;
454:
1.36 mrg 455: #ifdef PFIL_HOOKS
1.33 mrg 456: /*
1.64 thorpej 457: * Run through list of hooks for input packets. If there are any
458: * filters which require that additional packets in the flow are
459: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
460: * Note that filters must _never_ set this flag, as another filter
461: * in the list may have previously cleared it.
1.33 mrg 462: */
463: m0 = m;
1.59 mrg 464: for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33 mrg 465: if (pfh->pfil_func) {
1.43 mrg 466: rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
467: if (rv)
1.82.2.2.2.2! thorpej 468: return;
1.68 sommerfe 469: m = m0;
470: if (m == NULL)
1.82.2.2.2.2! thorpej 471: return;
1.68 sommerfe 472: ip = mtod(m, struct ip *);
1.33 mrg 473: }
1.36 mrg 474: #endif /* PFIL_HOOKS */
1.33 mrg 475:
1.1 cgd 476: /*
477: * Process options and, if not destined for us,
478: * ship it on. ip_dooptions returns 1 when an
479: * error was detected (causing an icmp message
480: * to be sent and the original packet to be freed).
481: */
482: ip_nhops = 0; /* for source routed packets */
483: if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.82.2.2.2.2! thorpej 484: return;
1.1 cgd 485:
486: /*
487: * Check our list of addresses, to see if the packet is for us.
488: */
1.57 tls 489: INADDR_TO_IA(ip->ip_dst, ia);
1.82.2.2 perry 490: if (ia != NULL)
491: goto ours;
1.57 tls 492: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
493: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
494: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
495: if (ifa->ifa_addr->sa_family != AF_INET) continue;
496: ia = ifatoia(ifa);
1.35 mycroft 497: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
498: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 499: /*
500: * Look for all-0's host part (old broadcast addr),
501: * either for subnet or net.
502: */
503: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 504: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 505: goto ours;
1.57 tls 506: /*
507: * An interface with IP address zero accepts
508: * all packets that arrive on that interface.
509: */
510: if (in_nullhost(ia->ia_addr.sin_addr))
511: goto ours;
1.1 cgd 512: }
513: }
1.18 mycroft 514: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 515: struct in_multi *inm;
516: #ifdef MROUTING
517: extern struct socket *ip_mrouter;
1.10 brezak 518:
519: if (m->m_flags & M_EXT) {
520: if ((m = m_pullup(m, hlen)) == 0) {
521: ipstat.ips_toosmall++;
1.82.2.2.2.2! thorpej 522: return;
1.10 brezak 523: }
524: ip = mtod(m, struct ip *);
525: }
1.4 hpeyerl 526:
527: if (ip_mrouter) {
528: /*
529: * If we are acting as a multicast router, all
530: * incoming multicast packets are passed to the
531: * kernel-level multicast forwarding function.
532: * The packet is returned (relatively) intact; if
533: * ip_mforward() returns a non-zero value, the packet
534: * must be discarded, else it may be accepted below.
535: *
536: * (The IP ident field is put in the same byte order
537: * as expected when ip_mforward() is called from
538: * ip_output().)
539: */
1.13 mycroft 540: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
541: ipstat.ips_cantforward++;
1.4 hpeyerl 542: m_freem(m);
1.82.2.2.2.2! thorpej 543: return;
1.4 hpeyerl 544: }
545:
546: /*
547: * The process-level routing demon needs to receive
548: * all multicast IGMP packets, whether or not this
549: * host belongs to their destination groups.
550: */
551: if (ip->ip_p == IPPROTO_IGMP)
552: goto ours;
1.13 mycroft 553: ipstat.ips_forward++;
1.4 hpeyerl 554: }
555: #endif
556: /*
557: * See if we belong to the destination multicast group on the
558: * arrival interface.
559: */
560: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
561: if (inm == NULL) {
1.13 mycroft 562: ipstat.ips_cantforward++;
1.4 hpeyerl 563: m_freem(m);
1.82.2.2.2.2! thorpej 564: return;
1.4 hpeyerl 565: }
566: goto ours;
567: }
1.19 mycroft 568: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 569: in_nullhost(ip->ip_dst))
1.1 cgd 570: goto ours;
571:
572: /*
573: * Not for us; forward if possible and desirable.
574: */
575: if (ipforwarding == 0) {
576: ipstat.ips_cantforward++;
577: m_freem(m);
578: } else
579: ip_forward(m, 0);
1.82.2.2.2.2! thorpej 580: return;
1.1 cgd 581:
582: ours:
583: /*
584: * If offset or IP_MF are set, must reassemble.
585: * Otherwise, nothing need be done.
586: * (We could look in the reassembly queue to see
587: * if the packet was previously fragmented,
588: * but it's not worth the time; just let them time out.)
589: */
1.37 perry 590: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 591: /*
592: * Look for queue of fragments
593: * of this datagram.
594: */
1.75 thorpej 595: IPQ_LOCK();
1.25 cgd 596: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 597: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 598: in_hosteq(ip->ip_src, fp->ipq_src) &&
599: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 600: ip->ip_p == fp->ipq_p)
601: goto found;
602: fp = 0;
603: found:
604:
605: /*
606: * Adjust ip_len to not reflect header,
1.25 cgd 607: * set ipqe_mff if more fragments are expected,
1.1 cgd 608: * convert offset of this to bytes.
609: */
610: ip->ip_len -= hlen;
1.25 cgd 611: mff = (ip->ip_off & IP_MF) != 0;
612: if (mff) {
1.16 cgd 613: /*
614: * Make sure that fragments have a data length
615: * that's a non-zero multiple of 8 bytes.
616: */
1.17 cgd 617: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 618: ipstat.ips_badfrags++;
1.75 thorpej 619: IPQ_UNLOCK();
1.16 cgd 620: goto bad;
621: }
622: }
1.1 cgd 623: ip->ip_off <<= 3;
624:
625: /*
626: * If datagram marked as having more fragments
627: * or if this is not the first fragment,
628: * attempt reassembly; if it succeeds, proceed.
629: */
1.25 cgd 630: if (mff || ip->ip_off) {
1.1 cgd 631: ipstat.ips_fragments++;
1.72 thorpej 632: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 633: if (ipqe == NULL) {
634: ipstat.ips_rcvmemdrop++;
1.75 thorpej 635: IPQ_UNLOCK();
1.25 cgd 636: goto bad;
637: }
638: ipqe->ipqe_mff = mff;
1.50 thorpej 639: ipqe->ipqe_m = m;
1.25 cgd 640: ipqe->ipqe_ip = ip;
1.50 thorpej 641: m = ip_reass(ipqe, fp);
1.75 thorpej 642: if (m == 0) {
643: IPQ_UNLOCK();
1.82.2.2.2.2! thorpej 644: return;
1.75 thorpej 645: }
1.13 mycroft 646: ipstat.ips_reassembled++;
1.50 thorpej 647: ip = mtod(m, struct ip *);
1.74 thorpej 648: hlen = ip->ip_hl << 2;
1.79 mycroft 649: ip->ip_len += hlen;
1.1 cgd 650: } else
651: if (fp)
652: ip_freef(fp);
1.75 thorpej 653: IPQ_UNLOCK();
1.79 mycroft 654: }
1.1 cgd 655:
656: /*
657: * Switch out to protocol's input routine.
658: */
1.82 aidan 659: #if IFA_STATS
660: ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
661: #endif
1.1 cgd 662: ipstat.ips_delivered++;
1.82.2.2.2.2! thorpej 663: {
! 664: int off = hlen, nh = ip->ip_p;
! 665:
! 666: (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
! 667: return;
! 668: }
1.1 cgd 669: bad:
670: m_freem(m);
671: }
672:
673: /*
674: * Take incoming datagram fragment and try to
675: * reassemble it into whole datagram. If a chain for
676: * reassembly of this datagram already exists, then it
677: * is given as fp; otherwise have to make a chain.
678: */
1.50 thorpej 679: struct mbuf *
1.25 cgd 680: ip_reass(ipqe, fp)
681: register struct ipqent *ipqe;
1.1 cgd 682: register struct ipq *fp;
683: {
1.50 thorpej 684: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 685: register struct ipqent *nq, *p, *q;
686: struct ip *ip;
1.1 cgd 687: struct mbuf *t;
1.25 cgd 688: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 689: int i, next;
690:
1.75 thorpej 691: IPQ_LOCK_CHECK();
692:
1.1 cgd 693: /*
694: * Presence of header sizes in mbufs
695: * would confuse code below.
696: */
697: m->m_data += hlen;
698: m->m_len -= hlen;
699:
700: /*
701: * If first fragment to arrive, create a reassembly queue.
702: */
703: if (fp == 0) {
1.50 thorpej 704: MALLOC(fp, struct ipq *, sizeof (struct ipq),
705: M_FTABLE, M_NOWAIT);
706: if (fp == NULL)
1.1 cgd 707: goto dropfrag;
1.25 cgd 708: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 709: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 710: fp->ipq_p = ipqe->ipqe_ip->ip_p;
711: fp->ipq_id = ipqe->ipqe_ip->ip_id;
712: LIST_INIT(&fp->ipq_fragq);
713: fp->ipq_src = ipqe->ipqe_ip->ip_src;
714: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
715: p = NULL;
1.1 cgd 716: goto insert;
717: }
718:
719: /*
720: * Find a segment which begins after this one does.
721: */
1.25 cgd 722: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
723: p = q, q = q->ipqe_q.le_next)
724: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 725: break;
726:
727: /*
728: * If there is a preceding segment, it may provide some of
729: * our data already. If so, drop the data from the incoming
730: * segment. If it provides all of our data, drop us.
731: */
1.25 cgd 732: if (p != NULL) {
733: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
734: ipqe->ipqe_ip->ip_off;
1.1 cgd 735: if (i > 0) {
1.25 cgd 736: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 737: goto dropfrag;
1.50 thorpej 738: m_adj(ipqe->ipqe_m, i);
1.25 cgd 739: ipqe->ipqe_ip->ip_off += i;
740: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 741: }
742: }
743:
744: /*
745: * While we overlap succeeding segments trim them or,
746: * if they are completely covered, dequeue them.
747: */
1.25 cgd 748: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
749: q->ipqe_ip->ip_off; q = nq) {
750: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
751: q->ipqe_ip->ip_off;
752: if (i < q->ipqe_ip->ip_len) {
753: q->ipqe_ip->ip_len -= i;
754: q->ipqe_ip->ip_off += i;
1.50 thorpej 755: m_adj(q->ipqe_m, i);
1.1 cgd 756: break;
757: }
1.25 cgd 758: nq = q->ipqe_q.le_next;
1.50 thorpej 759: m_freem(q->ipqe_m);
1.25 cgd 760: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 761: pool_put(&ipqent_pool, q);
1.1 cgd 762: }
763:
764: insert:
765: /*
766: * Stick new segment in its place;
767: * check for complete reassembly.
768: */
1.25 cgd 769: if (p == NULL) {
770: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
771: } else {
772: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
773: }
1.1 cgd 774: next = 0;
1.25 cgd 775: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
776: p = q, q = q->ipqe_q.le_next) {
777: if (q->ipqe_ip->ip_off != next)
1.1 cgd 778: return (0);
1.25 cgd 779: next += q->ipqe_ip->ip_len;
1.1 cgd 780: }
1.25 cgd 781: if (p->ipqe_mff)
1.1 cgd 782: return (0);
783:
784: /*
1.41 thorpej 785: * Reassembly is complete. Check for a bogus message size and
786: * concatenate fragments.
1.1 cgd 787: */
1.25 cgd 788: q = fp->ipq_fragq.lh_first;
789: ip = q->ipqe_ip;
1.41 thorpej 790: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
791: ipstat.ips_toolong++;
792: ip_freef(fp);
793: return (0);
794: }
1.50 thorpej 795: m = q->ipqe_m;
1.1 cgd 796: t = m->m_next;
797: m->m_next = 0;
798: m_cat(m, t);
1.25 cgd 799: nq = q->ipqe_q.le_next;
1.72 thorpej 800: pool_put(&ipqent_pool, q);
1.25 cgd 801: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 802: t = q->ipqe_m;
1.25 cgd 803: nq = q->ipqe_q.le_next;
1.72 thorpej 804: pool_put(&ipqent_pool, q);
1.1 cgd 805: m_cat(m, t);
806: }
807:
808: /*
809: * Create header for new ip packet by
810: * modifying header of first packet;
811: * dequeue and discard fragment reassembly header.
812: * Make header visible.
813: */
814: ip->ip_len = next;
1.82.2.2.2.2! thorpej 815: ip->ip_ttl = 0; /* xxx */
! 816: ip->ip_sum = 0;
1.25 cgd 817: ip->ip_src = fp->ipq_src;
818: ip->ip_dst = fp->ipq_dst;
819: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 820: FREE(fp, M_FTABLE);
1.1 cgd 821: m->m_len += (ip->ip_hl << 2);
822: m->m_data -= (ip->ip_hl << 2);
823: /* some debugging cruft by sklower, below, will go away soon */
824: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
825: register int plen = 0;
1.50 thorpej 826: for (t = m; t; t = t->m_next)
827: plen += t->m_len;
828: m->m_pkthdr.len = plen;
1.1 cgd 829: }
1.50 thorpej 830: return (m);
1.1 cgd 831:
832: dropfrag:
833: ipstat.ips_fragdropped++;
834: m_freem(m);
1.72 thorpej 835: pool_put(&ipqent_pool, ipqe);
1.1 cgd 836: return (0);
837: }
838:
839: /*
840: * Free a fragment reassembly header and all
841: * associated datagrams.
842: */
1.8 mycroft 843: void
1.1 cgd 844: ip_freef(fp)
845: struct ipq *fp;
846: {
1.25 cgd 847: register struct ipqent *q, *p;
1.1 cgd 848:
1.75 thorpej 849: IPQ_LOCK_CHECK();
850:
1.25 cgd 851: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
852: p = q->ipqe_q.le_next;
1.50 thorpej 853: m_freem(q->ipqe_m);
1.25 cgd 854: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 855: pool_put(&ipqent_pool, q);
1.1 cgd 856: }
1.25 cgd 857: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 858: FREE(fp, M_FTABLE);
1.1 cgd 859: }
860:
861: /*
862: * IP timer processing;
863: * if a timer expires on a reassembly
864: * queue, discard it.
865: */
1.8 mycroft 866: void
1.1 cgd 867: ip_slowtimo()
868: {
1.25 cgd 869: register struct ipq *fp, *nfp;
1.24 mycroft 870: int s = splsoftnet();
1.1 cgd 871:
1.75 thorpej 872: IPQ_LOCK();
1.25 cgd 873: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
874: nfp = fp->ipq_q.le_next;
875: if (--fp->ipq_ttl == 0) {
1.1 cgd 876: ipstat.ips_fragtimeout++;
1.25 cgd 877: ip_freef(fp);
1.1 cgd 878: }
879: }
1.75 thorpej 880: IPQ_UNLOCK();
1.63 matt 881: #ifdef GATEWAY
882: ipflow_slowtimo();
883: #endif
1.1 cgd 884: splx(s);
885: }
886:
887: /*
888: * Drain off all datagram fragments.
889: */
1.8 mycroft 890: void
1.1 cgd 891: ip_drain()
892: {
893:
1.75 thorpej 894: /*
895: * We may be called from a device's interrupt context. If
896: * the ipq is already busy, just bail out now.
897: */
898: if (ipq_lock_try() == 0)
899: return;
900:
1.25 cgd 901: while (ipq.lh_first != NULL) {
1.1 cgd 902: ipstat.ips_fragdropped++;
1.25 cgd 903: ip_freef(ipq.lh_first);
1.1 cgd 904: }
1.75 thorpej 905:
906: IPQ_UNLOCK();
1.1 cgd 907: }
908:
909: /*
910: * Do option processing on a datagram,
911: * possibly discarding it if bad options are encountered,
912: * or forwarding it if source-routed.
913: * Returns 1 if packet has been forwarded/freed,
914: * 0 if the packet should be processed further.
915: */
1.8 mycroft 916: int
1.1 cgd 917: ip_dooptions(m)
918: struct mbuf *m;
919: {
920: register struct ip *ip = mtod(m, struct ip *);
921: register u_char *cp;
922: register struct ip_timestamp *ipt;
923: register struct in_ifaddr *ia;
924: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13 mycroft 925: struct in_addr *sin, dst;
1.1 cgd 926: n_time ntime;
927:
1.13 mycroft 928: dst = ip->ip_dst;
1.1 cgd 929: cp = (u_char *)(ip + 1);
930: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
931: for (; cnt > 0; cnt -= optlen, cp += optlen) {
932: opt = cp[IPOPT_OPTVAL];
933: if (opt == IPOPT_EOL)
934: break;
935: if (opt == IPOPT_NOP)
936: optlen = 1;
937: else {
938: optlen = cp[IPOPT_OLEN];
939: if (optlen <= 0 || optlen > cnt) {
940: code = &cp[IPOPT_OLEN] - (u_char *)ip;
941: goto bad;
942: }
943: }
944: switch (opt) {
945:
946: default:
947: break;
948:
949: /*
950: * Source routing with record.
951: * Find interface with current destination address.
952: * If none on this machine then drop if strictly routed,
953: * or do nothing if loosely routed.
954: * Record interface address and bring up next address
955: * component. If strictly routed make sure next
956: * address is on directly accessible net.
957: */
958: case IPOPT_LSRR:
959: case IPOPT_SSRR:
1.47 cjs 960: if (ip_allowsrcrt == 0) {
961: type = ICMP_UNREACH;
962: code = ICMP_UNREACH_NET_PROHIB;
963: goto bad;
964: }
1.1 cgd 965: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
966: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
967: goto bad;
968: }
969: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 970: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 971: if (ia == 0) {
972: if (opt == IPOPT_SSRR) {
973: type = ICMP_UNREACH;
974: code = ICMP_UNREACH_SRCFAIL;
975: goto bad;
976: }
977: /*
978: * Loose routing, and not at next destination
979: * yet; nothing to do except forward.
980: */
981: break;
982: }
983: off--; /* 0 origin */
984: if (off > optlen - sizeof(struct in_addr)) {
985: /*
986: * End of source route. Should be for us.
987: */
988: save_rte(cp, ip->ip_src);
989: break;
990: }
991: /*
992: * locate outgoing interface
993: */
994: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
995: sizeof(ipaddr.sin_addr));
996: if (opt == IPOPT_SSRR) {
997: #define INA struct in_ifaddr *
998: #define SA struct sockaddr *
1.29 mrg 999: ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1 cgd 1000: } else
1001: ia = ip_rtaddr(ipaddr.sin_addr);
1002: if (ia == 0) {
1003: type = ICMP_UNREACH;
1004: code = ICMP_UNREACH_SRCFAIL;
1005: goto bad;
1006: }
1007: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 1008: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1009: (caddr_t)(cp + off), sizeof(struct in_addr));
1010: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 1011: /*
1012: * Let ip_intr's mcast routing check handle mcast pkts
1013: */
1.18 mycroft 1014: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 1015: break;
1016:
1017: case IPOPT_RR:
1018: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1019: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1020: goto bad;
1021: }
1022: /*
1023: * If no space remains, ignore.
1024: */
1025: off--; /* 0 origin */
1026: if (off > optlen - sizeof(struct in_addr))
1027: break;
1028: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
1029: sizeof(ipaddr.sin_addr));
1030: /*
1031: * locate outgoing interface; if we're the destination,
1032: * use the incoming interface (should be same).
1033: */
1034: if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1035: (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1036: type = ICMP_UNREACH;
1037: code = ICMP_UNREACH_HOST;
1038: goto bad;
1039: }
1.20 mycroft 1040: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1041: (caddr_t)(cp + off), sizeof(struct in_addr));
1042: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1043: break;
1044:
1045: case IPOPT_TS:
1046: code = cp - (u_char *)ip;
1047: ipt = (struct ip_timestamp *)cp;
1048: if (ipt->ipt_len < 5)
1049: goto bad;
1.15 cgd 1050: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 1051: if (++ipt->ipt_oflw == 0)
1052: goto bad;
1053: break;
1054: }
1055: sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
1056: switch (ipt->ipt_flg) {
1057:
1058: case IPOPT_TS_TSONLY:
1059: break;
1060:
1061: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1062: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1063: sizeof(struct in_addr) > ipt->ipt_len)
1064: goto bad;
1.13 mycroft 1065: ipaddr.sin_addr = dst;
1066: ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1067: m->m_pkthdr.rcvif);
1068: if (ia == 0)
1069: continue;
1.20 mycroft 1070: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1071: (caddr_t)sin, sizeof(struct in_addr));
1072: ipt->ipt_ptr += sizeof(struct in_addr);
1073: break;
1074:
1075: case IPOPT_TS_PRESPEC:
1.66 thorpej 1076: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1077: sizeof(struct in_addr) > ipt->ipt_len)
1078: goto bad;
1079: bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
1080: sizeof(struct in_addr));
1081: if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1082: continue;
1083: ipt->ipt_ptr += sizeof(struct in_addr);
1084: break;
1085:
1086: default:
1087: goto bad;
1088: }
1089: ntime = iptime();
1090: bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
1091: sizeof(n_time));
1092: ipt->ipt_ptr += sizeof(n_time);
1093: }
1094: }
1095: if (forward) {
1.26 thorpej 1096: if (ip_forwsrcrt == 0) {
1097: type = ICMP_UNREACH;
1098: code = ICMP_UNREACH_SRCFAIL;
1099: goto bad;
1100: }
1.1 cgd 1101: ip_forward(m, 1);
1102: return (1);
1.13 mycroft 1103: }
1104: return (0);
1.1 cgd 1105: bad:
1.13 mycroft 1106: icmp_error(m, type, code, 0, 0);
1107: ipstat.ips_badoptions++;
1.1 cgd 1108: return (1);
1109: }
1110:
1111: /*
1112: * Given address of next destination (final or next hop),
1113: * return internet address info of interface to be used to get there.
1114: */
1115: struct in_ifaddr *
1116: ip_rtaddr(dst)
1117: struct in_addr dst;
1118: {
1119: register struct sockaddr_in *sin;
1120:
1.19 mycroft 1121: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1122:
1.35 mycroft 1123: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1124: if (ipforward_rt.ro_rt) {
1125: RTFREE(ipforward_rt.ro_rt);
1126: ipforward_rt.ro_rt = 0;
1127: }
1128: sin->sin_family = AF_INET;
1129: sin->sin_len = sizeof(*sin);
1130: sin->sin_addr = dst;
1131:
1132: rtalloc(&ipforward_rt);
1133: }
1134: if (ipforward_rt.ro_rt == 0)
1135: return ((struct in_ifaddr *)0);
1.19 mycroft 1136: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1137: }
1138:
1139: /*
1140: * Save incoming source route for use in replies,
1141: * to be picked up later by ip_srcroute if the receiver is interested.
1142: */
1.13 mycroft 1143: void
1.1 cgd 1144: save_rte(option, dst)
1145: u_char *option;
1146: struct in_addr dst;
1147: {
1148: unsigned olen;
1149:
1150: olen = option[IPOPT_OLEN];
1151: #ifdef DIAGNOSTIC
1152: if (ipprintfs)
1.39 christos 1153: printf("save_rte: olen %d\n", olen);
1.82.2.2.2.2! thorpej 1154: #endif /* 0 */
1.1 cgd 1155: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1156: return;
1157: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1158: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1159: ip_srcrt.dst = dst;
1160: }
1161:
1162: /*
1163: * Retrieve incoming source route for use in replies,
1164: * in the same form used by setsockopt.
1165: * The first hop is placed before the options, will be removed later.
1166: */
1167: struct mbuf *
1168: ip_srcroute()
1169: {
1170: register struct in_addr *p, *q;
1171: register struct mbuf *m;
1172:
1173: if (ip_nhops == 0)
1174: return ((struct mbuf *)0);
1175: m = m_get(M_DONTWAIT, MT_SOOPTS);
1176: if (m == 0)
1177: return ((struct mbuf *)0);
1178:
1.13 mycroft 1179: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1180:
1181: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1182: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1183: OPTSIZ;
1184: #ifdef DIAGNOSTIC
1185: if (ipprintfs)
1.39 christos 1186: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1187: #endif
1188:
1189: /*
1190: * First save first hop for return route
1191: */
1192: p = &ip_srcrt.route[ip_nhops - 1];
1193: *(mtod(m, struct in_addr *)) = *p--;
1194: #ifdef DIAGNOSTIC
1195: if (ipprintfs)
1.39 christos 1196: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1197: #endif
1198:
1199: /*
1200: * Copy option fields and padding (nop) to mbuf.
1201: */
1202: ip_srcrt.nop = IPOPT_NOP;
1203: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1204: bcopy((caddr_t)&ip_srcrt.nop,
1205: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1206: q = (struct in_addr *)(mtod(m, caddr_t) +
1207: sizeof(struct in_addr) + OPTSIZ);
1208: #undef OPTSIZ
1209: /*
1210: * Record return path as an IP source route,
1211: * reversing the path (pointers are now aligned).
1212: */
1213: while (p >= ip_srcrt.route) {
1214: #ifdef DIAGNOSTIC
1215: if (ipprintfs)
1.39 christos 1216: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1217: #endif
1218: *q++ = *p--;
1219: }
1220: /*
1221: * Last hop goes to final destination.
1222: */
1223: *q = ip_srcrt.dst;
1224: #ifdef DIAGNOSTIC
1225: if (ipprintfs)
1.39 christos 1226: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1227: #endif
1228: return (m);
1229: }
1230:
1231: /*
1232: * Strip out IP options, at higher
1233: * level protocol in the kernel.
1234: * Second argument is buffer to which options
1235: * will be moved, and return value is their length.
1236: * XXX should be deleted; last arg currently ignored.
1237: */
1.8 mycroft 1238: void
1.1 cgd 1239: ip_stripoptions(m, mopt)
1240: register struct mbuf *m;
1241: struct mbuf *mopt;
1242: {
1243: register int i;
1244: struct ip *ip = mtod(m, struct ip *);
1245: register caddr_t opts;
1246: int olen;
1247:
1.79 mycroft 1248: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1249: opts = (caddr_t)(ip + 1);
1250: i = m->m_len - (sizeof (struct ip) + olen);
1251: bcopy(opts + olen, opts, (unsigned)i);
1252: m->m_len -= olen;
1253: if (m->m_flags & M_PKTHDR)
1254: m->m_pkthdr.len -= olen;
1.79 mycroft 1255: ip->ip_len -= olen;
1256: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1257: }
1258:
1.23 mycroft 1259: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1260: 0, 0, 0, 0,
1261: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1262: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1263: EMSGSIZE, EHOSTUNREACH, 0, 0,
1264: 0, 0, 0, 0,
1265: ENOPROTOOPT
1266: };
1267:
1268: /*
1269: * Forward a packet. If some error occurs return the sender
1270: * an icmp packet. Note we can't always generate a meaningful
1271: * icmp message because icmp doesn't have a large enough repertoire
1272: * of codes and types.
1273: *
1274: * If not forwarding, just drop the packet. This could be confusing
1275: * if ipforwarding was zero but some routing protocol was advancing
1276: * us as a gateway to somewhere. However, we must let the routing
1277: * protocol deal with that.
1278: *
1279: * The srcrt parameter indicates whether the packet is being forwarded
1280: * via a source route.
1281: */
1.13 mycroft 1282: void
1.1 cgd 1283: ip_forward(m, srcrt)
1284: struct mbuf *m;
1285: int srcrt;
1286: {
1287: register struct ip *ip = mtod(m, struct ip *);
1288: register struct sockaddr_in *sin;
1289: register struct rtentry *rt;
1.28 christos 1290: int error, type = 0, code = 0;
1.1 cgd 1291: struct mbuf *mcopy;
1.13 mycroft 1292: n_long dest;
1293: struct ifnet *destifp;
1.82.2.2.2.2! thorpej 1294: #ifdef IPSEC
! 1295: struct ifnet dummyifp;
! 1296: #endif
1.1 cgd 1297:
1.13 mycroft 1298: dest = 0;
1.1 cgd 1299: #ifdef DIAGNOSTIC
1300: if (ipprintfs)
1.70 thorpej 1301: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1302: ntohl(ip->ip_src.s_addr),
1303: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1304: #endif
1305: if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
1306: ipstat.ips_cantforward++;
1307: m_freem(m);
1308: return;
1309: }
1310: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1311: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1312: return;
1313: }
1314: ip->ip_ttl -= IPTTLDEC;
1315:
1.19 mycroft 1316: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1317: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1318: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1319: if (ipforward_rt.ro_rt) {
1320: RTFREE(ipforward_rt.ro_rt);
1321: ipforward_rt.ro_rt = 0;
1322: }
1323: sin->sin_family = AF_INET;
1.35 mycroft 1324: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1325: sin->sin_addr = ip->ip_dst;
1326:
1327: rtalloc(&ipforward_rt);
1328: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1329: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1330: return;
1331: }
1332: rt = ipforward_rt.ro_rt;
1333: }
1334:
1335: /*
1.34 mycroft 1336: * Save at most 68 bytes of the packet in case
1.1 cgd 1337: * we need to generate an ICMP message to the src.
1338: */
1.34 mycroft 1339: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1340:
1341: /*
1342: * If forwarding packet using same interface that it came in on,
1343: * perhaps should send a redirect to sender to shortcut a hop.
1344: * Only send redirect if source is sending directly to us,
1345: * and if packet was not source routed (or has any options).
1346: * Also, don't send redirect if forwarding using a default route
1347: * or a route modified by a redirect.
1348: */
1349: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1350: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1351: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1352: ipsendredirects && !srcrt) {
1.19 mycroft 1353: if (rt->rt_ifa &&
1354: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1355: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1356: if (rt->rt_flags & RTF_GATEWAY)
1357: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1358: else
1359: dest = ip->ip_dst.s_addr;
1360: /*
1361: * Router requirements says to only send host
1362: * redirects.
1363: */
1364: type = ICMP_REDIRECT;
1365: code = ICMP_REDIRECT_HOST;
1.1 cgd 1366: #ifdef DIAGNOSTIC
1.77 thorpej 1367: if (ipprintfs)
1368: printf("redirect (%d) to %x\n", code,
1369: (u_int32_t)dest);
1.1 cgd 1370: #endif
1371: }
1372: }
1373:
1.82.2.2.2.2! thorpej 1374: #ifdef IPSEC
! 1375: m->m_pkthdr.rcvif = NULL;
! 1376: #endif /*IPSEC*/
1.27 thorpej 1377: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1378: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1379: if (error)
1380: ipstat.ips_cantforward++;
1381: else {
1382: ipstat.ips_forward++;
1383: if (type)
1384: ipstat.ips_redirectsent++;
1385: else {
1.63 matt 1386: if (mcopy) {
1387: #ifdef GATEWAY
1.64 thorpej 1388: if (mcopy->m_flags & M_CANFASTFWD)
1389: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1390: #endif
1.1 cgd 1391: m_freem(mcopy);
1.63 matt 1392: }
1.1 cgd 1393: return;
1394: }
1395: }
1396: if (mcopy == NULL)
1397: return;
1.13 mycroft 1398: destifp = NULL;
1399:
1.1 cgd 1400: switch (error) {
1401:
1402: case 0: /* forwarded, but need redirect */
1403: /* type, code set above */
1404: break;
1405:
1406: case ENETUNREACH: /* shouldn't happen, checked above */
1407: case EHOSTUNREACH:
1408: case ENETDOWN:
1409: case EHOSTDOWN:
1410: default:
1411: type = ICMP_UNREACH;
1412: code = ICMP_UNREACH_HOST;
1413: break;
1414:
1415: case EMSGSIZE:
1416: type = ICMP_UNREACH;
1417: code = ICMP_UNREACH_NEEDFRAG;
1.82.2.2.2.2! thorpej 1418: #ifndef IPSEC
1.13 mycroft 1419: if (ipforward_rt.ro_rt)
1420: destifp = ipforward_rt.ro_rt->rt_ifp;
1.82.2.2.2.2! thorpej 1421: #else
! 1422: /*
! 1423: * If the packet is routed over IPsec tunnel, tell the
! 1424: * originator the tunnel MTU.
! 1425: * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
! 1426: * XXX quickhack!!!
! 1427: */
! 1428: if (ipforward_rt.ro_rt) {
! 1429: struct secpolicy *sp;
! 1430: int ipsecerror;
! 1431: int ipsechdr;
! 1432: struct route *ro;
! 1433:
! 1434: sp = ipsec4_getpolicybyaddr(mcopy,
! 1435: IP_FORWARDING,
! 1436: &ipsecerror);
! 1437:
! 1438: if (sp == NULL)
! 1439: destifp = ipforward_rt.ro_rt->rt_ifp;
! 1440: else {
! 1441: /* count IPsec header size */
! 1442: ipsechdr = ipsec4_hdrsiz(mcopy, NULL);
! 1443:
! 1444: /*
! 1445: * find the correct route for outer IPv4
! 1446: * header, compute tunnel MTU.
! 1447: *
! 1448: * XXX BUG ALERT
! 1449: * The "dummyifp" code relies upon the fact
! 1450: * that icmp_error() touches only ifp->if_mtu.
! 1451: */
! 1452: /*XXX*/
! 1453: destifp = NULL;
! 1454: if (sp->req != NULL
! 1455: && sp->req->sa != NULL) {
! 1456: ro = &sp->req->sa->saidx->sa_route;
! 1457: if (ro->ro_rt && ro->ro_rt->rt_ifp) {
! 1458: dummyifp.if_mtu =
! 1459: ro->ro_rt->rt_ifp->if_mtu;
! 1460: dummyifp.if_mtu -= ipsechdr;
! 1461: destifp = &dummyifp;
! 1462: }
! 1463: }
! 1464:
! 1465: key_freesp(sp);
! 1466: }
! 1467: }
! 1468: #endif /*IPSEC*/
1.1 cgd 1469: ipstat.ips_cantfrag++;
1470: break;
1471:
1472: case ENOBUFS:
1473: type = ICMP_SOURCEQUENCH;
1474: code = 0;
1475: break;
1476: }
1.13 mycroft 1477: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1478: }
1479:
1480: void
1481: ip_savecontrol(inp, mp, ip, m)
1482: register struct inpcb *inp;
1483: register struct mbuf **mp;
1484: register struct ip *ip;
1485: register struct mbuf *m;
1486: {
1487:
1488: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1489: struct timeval tv;
1490:
1491: microtime(&tv);
1492: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1493: SCM_TIMESTAMP, SOL_SOCKET);
1494: if (*mp)
1495: mp = &(*mp)->m_next;
1496: }
1497: if (inp->inp_flags & INP_RECVDSTADDR) {
1498: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1499: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1500: if (*mp)
1501: mp = &(*mp)->m_next;
1502: }
1503: #ifdef notyet
1504: /*
1505: * XXX
1506: * Moving these out of udp_input() made them even more broken
1507: * than they already were.
1508: * - fenner@parc.xerox.com
1509: */
1510: /* options were tossed already */
1511: if (inp->inp_flags & INP_RECVOPTS) {
1512: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1513: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1514: if (*mp)
1515: mp = &(*mp)->m_next;
1516: }
1517: /* ip_srcroute doesn't do what we want here, need to fix */
1518: if (inp->inp_flags & INP_RECVRETOPTS) {
1519: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1520: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1521: if (*mp)
1522: mp = &(*mp)->m_next;
1523: }
1524: #endif
1525: if (inp->inp_flags & INP_RECVIF) {
1526: struct sockaddr_dl sdl;
1527:
1528: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1529: sdl.sdl_family = AF_LINK;
1530: sdl.sdl_index = m->m_pkthdr.rcvif ?
1531: m->m_pkthdr.rcvif->if_index : 0;
1532: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1533: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1534: IP_RECVIF, IPPROTO_IP);
1535: if (*mp)
1536: mp = &(*mp)->m_next;
1537: }
1.13 mycroft 1538: }
1539:
1540: int
1541: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1542: int *name;
1543: u_int namelen;
1544: void *oldp;
1545: size_t *oldlenp;
1546: void *newp;
1547: size_t newlen;
1548: {
1.82.2.2.2.2! thorpej 1549: extern int subnetsarelocal, hostzeroisbroadcast;
1.52 thorpej 1550:
1.54 lukem 1551: int error, old;
1552:
1.13 mycroft 1553: /* All sysctl names at this level are terminal. */
1554: if (namelen != 1)
1555: return (ENOTDIR);
1556:
1557: switch (name[0]) {
1558: case IPCTL_FORWARDING:
1559: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1560: case IPCTL_SENDREDIRECTS:
1561: return (sysctl_int(oldp, oldlenp, newp, newlen,
1562: &ipsendredirects));
1563: case IPCTL_DEFTTL:
1564: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1565: #ifdef notyet
1566: case IPCTL_DEFMTU:
1567: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1568: #endif
1.26 thorpej 1569: case IPCTL_FORWSRCRT:
1.47 cjs 1570: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1571: if (securelevel > 0)
1.46 cjs 1572: return (sysctl_rdint(oldp, oldlenp, newp,
1573: ip_forwsrcrt));
1574: else
1575: return (sysctl_int(oldp, oldlenp, newp, newlen,
1576: &ip_forwsrcrt));
1.27 thorpej 1577: case IPCTL_DIRECTEDBCAST:
1578: return (sysctl_int(oldp, oldlenp, newp, newlen,
1579: &ip_directedbcast));
1.47 cjs 1580: case IPCTL_ALLOWSRCRT:
1581: return (sysctl_int(oldp, oldlenp, newp, newlen,
1582: &ip_allowsrcrt));
1.52 thorpej 1583: case IPCTL_SUBNETSARELOCAL:
1584: return (sysctl_int(oldp, oldlenp, newp, newlen,
1585: &subnetsarelocal));
1.53 kml 1586: case IPCTL_MTUDISC:
1.60 kml 1587: error = sysctl_int(oldp, oldlenp, newp, newlen,
1588: &ip_mtudisc);
1589: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1590: ip_mtudisc_timeout_q =
1591: rt_timer_queue_create(ip_mtudisc_timeout);
1592: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1593: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1594: ip_mtudisc_timeout_q = NULL;
1595: }
1596: return error;
1.54 lukem 1597: case IPCTL_ANONPORTMIN:
1598: old = anonportmin;
1599: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1600: if (anonportmin >= anonportmax || anonportmin > 65535
1601: #ifndef IPNOPRIVPORTS
1602: || anonportmin < IPPORT_RESERVED
1603: #endif
1604: ) {
1605: anonportmin = old;
1606: return (EINVAL);
1607: }
1608: return (error);
1609: case IPCTL_ANONPORTMAX:
1610: old = anonportmax;
1611: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1612: if (anonportmin >= anonportmax || anonportmax > 65535
1613: #ifndef IPNOPRIVPORTS
1614: || anonportmax < IPPORT_RESERVED
1615: #endif
1616: ) {
1617: anonportmax = old;
1618: return (EINVAL);
1619: }
1.60 kml 1620: return (error);
1621: case IPCTL_MTUDISCTIMEOUT:
1622: error = sysctl_int(oldp, oldlenp, newp, newlen,
1623: &ip_mtudisc_timeout);
1624: if (ip_mtudisc_timeout_q != NULL)
1625: rt_timer_queue_change(ip_mtudisc_timeout_q,
1626: ip_mtudisc_timeout);
1.54 lukem 1627: return (error);
1.65 matt 1628: #ifdef GATEWAY
1629: case IPCTL_MAXFLOWS:
1.67 thorpej 1630: {
1631: int s;
1632:
1.65 matt 1633: error = sysctl_int(oldp, oldlenp, newp, newlen,
1634: &ip_maxflows);
1.67 thorpej 1635: s = splsoftnet();
1.65 matt 1636: ipflow_reap(0);
1.67 thorpej 1637: splx(s);
1.65 matt 1638: return (error);
1.67 thorpej 1639: }
1.65 matt 1640: #endif
1.82.2.2.2.2! thorpej 1641: #if NGIF > 0
! 1642: case IPCTL_GIF_TTL:
! 1643: return(sysctl_int(oldp, oldlenp, newp, newlen,
! 1644: &gif_ttl));
! 1645: #endif
! 1646: case IPCTL_HOSTZEROBROADCAST:
! 1647: return (sysctl_int(oldp, oldlenp, newp, newlen,
! 1648: &hostzeroisbroadcast));
! 1649:
1.13 mycroft 1650: default:
1651: return (EOPNOTSUPP);
1652: }
1653: /* NOTREACHED */
1.1 cgd 1654: }
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