Annotation of src/sys/netinet/ip_input.c, Revision 1.82.2.2.4.3
1.82.2.2.4.3! itojun 1: /* $NetBSD: ip_input.c,v 1.82.2.2 1999/05/03 22:22:42 perry Exp $ */
1.82.2.2.4.2 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"
1.82.2.2.4.3! itojun 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>
1.82.2.2.4.1 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 <netkey/key.h>
145: #include <netkey/key_debug.h>
146: #endif
1.44 thorpej 147:
1.1 cgd 148: #ifndef IPFORWARDING
149: #ifdef GATEWAY
150: #define IPFORWARDING 1 /* forward IP packets not for us */
151: #else /* GATEWAY */
152: #define IPFORWARDING 0 /* don't forward IP packets not for us */
153: #endif /* GATEWAY */
154: #endif /* IPFORWARDING */
155: #ifndef IPSENDREDIRECTS
156: #define IPSENDREDIRECTS 1
157: #endif
1.26 thorpej 158: #ifndef IPFORWSRCRT
1.47 cjs 159: #define IPFORWSRCRT 1 /* forward source-routed packets */
160: #endif
161: #ifndef IPALLOWSRCRT
1.48 mrg 162: #define IPALLOWSRCRT 1 /* allow source-routed packets */
1.26 thorpej 163: #endif
1.53 kml 164: #ifndef IPMTUDISC
165: #define IPMTUDISC 0
166: #endif
1.60 kml 167: #ifndef IPMTUDISCTIMEOUT
1.61 kml 168: #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
1.60 kml 169: #endif
1.53 kml 170:
1.27 thorpej 171: /*
172: * Note: DIRECTED_BROADCAST is handled this way so that previous
173: * configuration using this option will Just Work.
174: */
175: #ifndef IPDIRECTEDBCAST
176: #ifdef DIRECTED_BROADCAST
177: #define IPDIRECTEDBCAST 1
178: #else
179: #define IPDIRECTEDBCAST 0
180: #endif /* DIRECTED_BROADCAST */
181: #endif /* IPDIRECTEDBCAST */
1.1 cgd 182: int ipforwarding = IPFORWARDING;
183: int ipsendredirects = IPSENDREDIRECTS;
1.13 mycroft 184: int ip_defttl = IPDEFTTL;
1.26 thorpej 185: int ip_forwsrcrt = IPFORWSRCRT;
1.27 thorpej 186: int ip_directedbcast = IPDIRECTEDBCAST;
1.47 cjs 187: int ip_allowsrcrt = IPALLOWSRCRT;
1.53 kml 188: int ip_mtudisc = IPMTUDISC;
1.60 kml 189: u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1 cgd 190: #ifdef DIAGNOSTIC
191: int ipprintfs = 0;
192: #endif
193:
1.60 kml 194: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
195:
1.82.2.2.4.3! itojun 196: #ifdef ALTQ
! 197: int (*altq_input) __P((struct mbuf *, int)) = NULL;
! 198: #endif
! 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: /*
1.82.2.2.4.1 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
1.82.2.2.4.1 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;
1.82.2.2.4.1 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
1.82.2.2.4.1 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++;
1.82.2.2.4.1 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++;
1.82.2.2.4.1 itojun 400: return;
1.1 cgd 401: }
402: ip = mtod(m, struct ip *);
403: }
1.78 mycroft 404: if (in_cksum(m, hlen) != 0) {
1.1 cgd 405: ipstat.ips_badsum++;
406: goto bad;
407: }
408:
1.82.2.2.4.3! itojun 409: #ifdef ALTQ
! 410: if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
! 411: /* packet is dropped by traffic conditioner */
! 412: return;
! 413: #endif
1.1 cgd 414: /*
415: * Convert fields to host representation.
416: */
417: NTOHS(ip->ip_len);
418: NTOHS(ip->ip_off);
1.35 mycroft 419: len = ip->ip_len;
1.81 proff 420:
421: /*
422: * Check for additional length bogosity
423: */
424: if (len < hlen)
425: {
426: ipstat.ips_badlen++;
427: goto bad;
428: }
1.1 cgd 429:
430: /*
431: * Check that the amount of data in the buffers
432: * is as at least much as the IP header would have us expect.
433: * Trim mbufs if longer than we expect.
434: * Drop packet if shorter than we expect.
435: */
1.35 mycroft 436: if (m->m_pkthdr.len < len) {
1.1 cgd 437: ipstat.ips_tooshort++;
438: goto bad;
439: }
1.35 mycroft 440: if (m->m_pkthdr.len > len) {
1.1 cgd 441: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 442: m->m_len = len;
443: m->m_pkthdr.len = len;
1.1 cgd 444: } else
1.35 mycroft 445: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 446: }
447:
1.82.2.2.4.3! itojun 448: #ifdef IPSEC
! 449: /* ipflow (IP fast fowarding) is not compatible with IPsec. */
! 450: m->m_flags &= ~M_CANFASTFWD;
! 451: #else
1.64 thorpej 452: /*
453: * Assume that we can create a fast-forward IP flow entry
454: * based on this packet.
455: */
456: m->m_flags |= M_CANFASTFWD;
1.82.2.2.4.3! itojun 457: #endif
1.64 thorpej 458:
1.36 mrg 459: #ifdef PFIL_HOOKS
1.33 mrg 460: /*
1.64 thorpej 461: * Run through list of hooks for input packets. If there are any
462: * filters which require that additional packets in the flow are
463: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
464: * Note that filters must _never_ set this flag, as another filter
465: * in the list may have previously cleared it.
1.33 mrg 466: */
467: m0 = m;
1.59 mrg 468: for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33 mrg 469: if (pfh->pfil_func) {
1.43 mrg 470: rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
471: if (rv)
1.82.2.2.4.1 itojun 472: return;
1.68 sommerfe 473: m = m0;
474: if (m == NULL)
1.82.2.2.4.1 itojun 475: return;
1.68 sommerfe 476: ip = mtod(m, struct ip *);
1.33 mrg 477: }
1.36 mrg 478: #endif /* PFIL_HOOKS */
1.33 mrg 479:
1.1 cgd 480: /*
481: * Process options and, if not destined for us,
482: * ship it on. ip_dooptions returns 1 when an
483: * error was detected (causing an icmp message
484: * to be sent and the original packet to be freed).
485: */
486: ip_nhops = 0; /* for source routed packets */
487: if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.82.2.2.4.1 itojun 488: return;
1.1 cgd 489:
490: /*
491: * Check our list of addresses, to see if the packet is for us.
492: */
1.57 tls 493: INADDR_TO_IA(ip->ip_dst, ia);
1.82.2.2 perry 494: if (ia != NULL)
495: goto ours;
1.57 tls 496: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
497: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
498: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
499: if (ifa->ifa_addr->sa_family != AF_INET) continue;
500: ia = ifatoia(ifa);
1.35 mycroft 501: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
502: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 503: /*
504: * Look for all-0's host part (old broadcast addr),
505: * either for subnet or net.
506: */
507: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 508: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 509: goto ours;
1.57 tls 510: /*
511: * An interface with IP address zero accepts
512: * all packets that arrive on that interface.
513: */
514: if (in_nullhost(ia->ia_addr.sin_addr))
515: goto ours;
1.1 cgd 516: }
517: }
1.18 mycroft 518: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 519: struct in_multi *inm;
520: #ifdef MROUTING
521: extern struct socket *ip_mrouter;
1.10 brezak 522:
523: if (m->m_flags & M_EXT) {
524: if ((m = m_pullup(m, hlen)) == 0) {
525: ipstat.ips_toosmall++;
1.82.2.2.4.1 itojun 526: return;
1.10 brezak 527: }
528: ip = mtod(m, struct ip *);
529: }
1.4 hpeyerl 530:
531: if (ip_mrouter) {
532: /*
533: * If we are acting as a multicast router, all
534: * incoming multicast packets are passed to the
535: * kernel-level multicast forwarding function.
536: * The packet is returned (relatively) intact; if
537: * ip_mforward() returns a non-zero value, the packet
538: * must be discarded, else it may be accepted below.
539: *
540: * (The IP ident field is put in the same byte order
541: * as expected when ip_mforward() is called from
542: * ip_output().)
543: */
1.13 mycroft 544: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
545: ipstat.ips_cantforward++;
1.4 hpeyerl 546: m_freem(m);
1.82.2.2.4.1 itojun 547: return;
1.4 hpeyerl 548: }
549:
550: /*
551: * The process-level routing demon needs to receive
552: * all multicast IGMP packets, whether or not this
553: * host belongs to their destination groups.
554: */
555: if (ip->ip_p == IPPROTO_IGMP)
556: goto ours;
1.13 mycroft 557: ipstat.ips_forward++;
1.4 hpeyerl 558: }
559: #endif
560: /*
561: * See if we belong to the destination multicast group on the
562: * arrival interface.
563: */
564: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
565: if (inm == NULL) {
1.13 mycroft 566: ipstat.ips_cantforward++;
1.4 hpeyerl 567: m_freem(m);
1.82.2.2.4.1 itojun 568: return;
1.4 hpeyerl 569: }
570: goto ours;
571: }
1.19 mycroft 572: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 573: in_nullhost(ip->ip_dst))
1.1 cgd 574: goto ours;
575:
576: /*
577: * Not for us; forward if possible and desirable.
578: */
579: if (ipforwarding == 0) {
580: ipstat.ips_cantforward++;
581: m_freem(m);
582: } else
583: ip_forward(m, 0);
1.82.2.2.4.1 itojun 584: return;
1.1 cgd 585:
586: ours:
587: /*
588: * If offset or IP_MF are set, must reassemble.
589: * Otherwise, nothing need be done.
590: * (We could look in the reassembly queue to see
591: * if the packet was previously fragmented,
592: * but it's not worth the time; just let them time out.)
593: */
1.37 perry 594: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 595: /*
596: * Look for queue of fragments
597: * of this datagram.
598: */
1.75 thorpej 599: IPQ_LOCK();
1.25 cgd 600: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 601: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 602: in_hosteq(ip->ip_src, fp->ipq_src) &&
603: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 604: ip->ip_p == fp->ipq_p)
605: goto found;
606: fp = 0;
607: found:
608:
609: /*
610: * Adjust ip_len to not reflect header,
1.25 cgd 611: * set ipqe_mff if more fragments are expected,
1.1 cgd 612: * convert offset of this to bytes.
613: */
614: ip->ip_len -= hlen;
1.25 cgd 615: mff = (ip->ip_off & IP_MF) != 0;
616: if (mff) {
1.16 cgd 617: /*
618: * Make sure that fragments have a data length
619: * that's a non-zero multiple of 8 bytes.
620: */
1.17 cgd 621: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 622: ipstat.ips_badfrags++;
1.75 thorpej 623: IPQ_UNLOCK();
1.16 cgd 624: goto bad;
625: }
626: }
1.1 cgd 627: ip->ip_off <<= 3;
628:
629: /*
630: * If datagram marked as having more fragments
631: * or if this is not the first fragment,
632: * attempt reassembly; if it succeeds, proceed.
633: */
1.25 cgd 634: if (mff || ip->ip_off) {
1.1 cgd 635: ipstat.ips_fragments++;
1.72 thorpej 636: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 637: if (ipqe == NULL) {
638: ipstat.ips_rcvmemdrop++;
1.75 thorpej 639: IPQ_UNLOCK();
1.25 cgd 640: goto bad;
641: }
642: ipqe->ipqe_mff = mff;
1.50 thorpej 643: ipqe->ipqe_m = m;
1.25 cgd 644: ipqe->ipqe_ip = ip;
1.50 thorpej 645: m = ip_reass(ipqe, fp);
1.75 thorpej 646: if (m == 0) {
647: IPQ_UNLOCK();
1.82.2.2.4.1 itojun 648: return;
1.75 thorpej 649: }
1.13 mycroft 650: ipstat.ips_reassembled++;
1.50 thorpej 651: ip = mtod(m, struct ip *);
1.74 thorpej 652: hlen = ip->ip_hl << 2;
1.79 mycroft 653: ip->ip_len += hlen;
1.1 cgd 654: } else
655: if (fp)
656: ip_freef(fp);
1.75 thorpej 657: IPQ_UNLOCK();
1.79 mycroft 658: }
1.1 cgd 659:
660: /*
661: * Switch out to protocol's input routine.
662: */
1.82 aidan 663: #if IFA_STATS
664: ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
665: #endif
1.1 cgd 666: ipstat.ips_delivered++;
1.82.2.2.4.1 itojun 667: {
668: int off = hlen, nh = ip->ip_p;
669:
670: (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
671: return;
672: }
1.1 cgd 673: bad:
674: m_freem(m);
675: }
676:
677: /*
678: * Take incoming datagram fragment and try to
679: * reassemble it into whole datagram. If a chain for
680: * reassembly of this datagram already exists, then it
681: * is given as fp; otherwise have to make a chain.
682: */
1.50 thorpej 683: struct mbuf *
1.25 cgd 684: ip_reass(ipqe, fp)
685: register struct ipqent *ipqe;
1.1 cgd 686: register struct ipq *fp;
687: {
1.50 thorpej 688: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 689: register struct ipqent *nq, *p, *q;
690: struct ip *ip;
1.1 cgd 691: struct mbuf *t;
1.25 cgd 692: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 693: int i, next;
694:
1.75 thorpej 695: IPQ_LOCK_CHECK();
696:
1.1 cgd 697: /*
698: * Presence of header sizes in mbufs
699: * would confuse code below.
700: */
701: m->m_data += hlen;
702: m->m_len -= hlen;
703:
704: /*
705: * If first fragment to arrive, create a reassembly queue.
706: */
707: if (fp == 0) {
1.50 thorpej 708: MALLOC(fp, struct ipq *, sizeof (struct ipq),
709: M_FTABLE, M_NOWAIT);
710: if (fp == NULL)
1.1 cgd 711: goto dropfrag;
1.25 cgd 712: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 713: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 714: fp->ipq_p = ipqe->ipqe_ip->ip_p;
715: fp->ipq_id = ipqe->ipqe_ip->ip_id;
716: LIST_INIT(&fp->ipq_fragq);
717: fp->ipq_src = ipqe->ipqe_ip->ip_src;
718: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
719: p = NULL;
1.1 cgd 720: goto insert;
721: }
722:
723: /*
724: * Find a segment which begins after this one does.
725: */
1.25 cgd 726: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
727: p = q, q = q->ipqe_q.le_next)
728: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 729: break;
730:
731: /*
732: * If there is a preceding segment, it may provide some of
733: * our data already. If so, drop the data from the incoming
734: * segment. If it provides all of our data, drop us.
735: */
1.25 cgd 736: if (p != NULL) {
737: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
738: ipqe->ipqe_ip->ip_off;
1.1 cgd 739: if (i > 0) {
1.25 cgd 740: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 741: goto dropfrag;
1.50 thorpej 742: m_adj(ipqe->ipqe_m, i);
1.25 cgd 743: ipqe->ipqe_ip->ip_off += i;
744: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 745: }
746: }
747:
748: /*
749: * While we overlap succeeding segments trim them or,
750: * if they are completely covered, dequeue them.
751: */
1.25 cgd 752: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
753: q->ipqe_ip->ip_off; q = nq) {
754: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
755: q->ipqe_ip->ip_off;
756: if (i < q->ipqe_ip->ip_len) {
757: q->ipqe_ip->ip_len -= i;
758: q->ipqe_ip->ip_off += i;
1.50 thorpej 759: m_adj(q->ipqe_m, i);
1.1 cgd 760: break;
761: }
1.25 cgd 762: nq = q->ipqe_q.le_next;
1.50 thorpej 763: m_freem(q->ipqe_m);
1.25 cgd 764: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 765: pool_put(&ipqent_pool, q);
1.1 cgd 766: }
767:
768: insert:
769: /*
770: * Stick new segment in its place;
771: * check for complete reassembly.
772: */
1.25 cgd 773: if (p == NULL) {
774: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
775: } else {
776: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
777: }
1.1 cgd 778: next = 0;
1.25 cgd 779: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
780: p = q, q = q->ipqe_q.le_next) {
781: if (q->ipqe_ip->ip_off != next)
1.1 cgd 782: return (0);
1.25 cgd 783: next += q->ipqe_ip->ip_len;
1.1 cgd 784: }
1.25 cgd 785: if (p->ipqe_mff)
1.1 cgd 786: return (0);
787:
788: /*
1.41 thorpej 789: * Reassembly is complete. Check for a bogus message size and
790: * concatenate fragments.
1.1 cgd 791: */
1.25 cgd 792: q = fp->ipq_fragq.lh_first;
793: ip = q->ipqe_ip;
1.41 thorpej 794: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
795: ipstat.ips_toolong++;
796: ip_freef(fp);
797: return (0);
798: }
1.50 thorpej 799: m = q->ipqe_m;
1.1 cgd 800: t = m->m_next;
801: m->m_next = 0;
802: m_cat(m, t);
1.25 cgd 803: nq = q->ipqe_q.le_next;
1.72 thorpej 804: pool_put(&ipqent_pool, q);
1.25 cgd 805: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 806: t = q->ipqe_m;
1.25 cgd 807: nq = q->ipqe_q.le_next;
1.72 thorpej 808: pool_put(&ipqent_pool, q);
1.1 cgd 809: m_cat(m, t);
810: }
811:
812: /*
813: * Create header for new ip packet by
814: * modifying header of first packet;
815: * dequeue and discard fragment reassembly header.
816: * Make header visible.
817: */
818: ip->ip_len = next;
1.82.2.2.4.1 itojun 819: ip->ip_ttl = 0; /* xxx */
820: ip->ip_sum = 0;
1.25 cgd 821: ip->ip_src = fp->ipq_src;
822: ip->ip_dst = fp->ipq_dst;
823: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 824: FREE(fp, M_FTABLE);
1.1 cgd 825: m->m_len += (ip->ip_hl << 2);
826: m->m_data -= (ip->ip_hl << 2);
827: /* some debugging cruft by sklower, below, will go away soon */
828: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
829: register int plen = 0;
1.50 thorpej 830: for (t = m; t; t = t->m_next)
831: plen += t->m_len;
832: m->m_pkthdr.len = plen;
1.1 cgd 833: }
1.50 thorpej 834: return (m);
1.1 cgd 835:
836: dropfrag:
837: ipstat.ips_fragdropped++;
838: m_freem(m);
1.72 thorpej 839: pool_put(&ipqent_pool, ipqe);
1.1 cgd 840: return (0);
841: }
842:
843: /*
844: * Free a fragment reassembly header and all
845: * associated datagrams.
846: */
1.8 mycroft 847: void
1.1 cgd 848: ip_freef(fp)
849: struct ipq *fp;
850: {
1.25 cgd 851: register struct ipqent *q, *p;
1.1 cgd 852:
1.75 thorpej 853: IPQ_LOCK_CHECK();
854:
1.25 cgd 855: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
856: p = q->ipqe_q.le_next;
1.50 thorpej 857: m_freem(q->ipqe_m);
1.25 cgd 858: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 859: pool_put(&ipqent_pool, q);
1.1 cgd 860: }
1.25 cgd 861: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 862: FREE(fp, M_FTABLE);
1.1 cgd 863: }
864:
865: /*
866: * IP timer processing;
867: * if a timer expires on a reassembly
868: * queue, discard it.
869: */
1.8 mycroft 870: void
1.1 cgd 871: ip_slowtimo()
872: {
1.25 cgd 873: register struct ipq *fp, *nfp;
1.24 mycroft 874: int s = splsoftnet();
1.1 cgd 875:
1.75 thorpej 876: IPQ_LOCK();
1.25 cgd 877: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
878: nfp = fp->ipq_q.le_next;
879: if (--fp->ipq_ttl == 0) {
1.1 cgd 880: ipstat.ips_fragtimeout++;
1.25 cgd 881: ip_freef(fp);
1.1 cgd 882: }
883: }
1.75 thorpej 884: IPQ_UNLOCK();
1.63 matt 885: #ifdef GATEWAY
886: ipflow_slowtimo();
887: #endif
1.1 cgd 888: splx(s);
889: }
890:
891: /*
892: * Drain off all datagram fragments.
893: */
1.8 mycroft 894: void
1.1 cgd 895: ip_drain()
896: {
897:
1.75 thorpej 898: /*
899: * We may be called from a device's interrupt context. If
900: * the ipq is already busy, just bail out now.
901: */
902: if (ipq_lock_try() == 0)
903: return;
904:
1.25 cgd 905: while (ipq.lh_first != NULL) {
1.1 cgd 906: ipstat.ips_fragdropped++;
1.25 cgd 907: ip_freef(ipq.lh_first);
1.1 cgd 908: }
1.75 thorpej 909:
910: IPQ_UNLOCK();
1.1 cgd 911: }
912:
913: /*
914: * Do option processing on a datagram,
915: * possibly discarding it if bad options are encountered,
916: * or forwarding it if source-routed.
917: * Returns 1 if packet has been forwarded/freed,
918: * 0 if the packet should be processed further.
919: */
1.8 mycroft 920: int
1.1 cgd 921: ip_dooptions(m)
922: struct mbuf *m;
923: {
924: register struct ip *ip = mtod(m, struct ip *);
925: register u_char *cp;
926: register struct ip_timestamp *ipt;
927: register struct in_ifaddr *ia;
928: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13 mycroft 929: struct in_addr *sin, dst;
1.1 cgd 930: n_time ntime;
931:
1.13 mycroft 932: dst = ip->ip_dst;
1.1 cgd 933: cp = (u_char *)(ip + 1);
934: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
935: for (; cnt > 0; cnt -= optlen, cp += optlen) {
936: opt = cp[IPOPT_OPTVAL];
937: if (opt == IPOPT_EOL)
938: break;
939: if (opt == IPOPT_NOP)
940: optlen = 1;
941: else {
942: optlen = cp[IPOPT_OLEN];
943: if (optlen <= 0 || optlen > cnt) {
944: code = &cp[IPOPT_OLEN] - (u_char *)ip;
945: goto bad;
946: }
947: }
948: switch (opt) {
949:
950: default:
951: break;
952:
953: /*
954: * Source routing with record.
955: * Find interface with current destination address.
956: * If none on this machine then drop if strictly routed,
957: * or do nothing if loosely routed.
958: * Record interface address and bring up next address
959: * component. If strictly routed make sure next
960: * address is on directly accessible net.
961: */
962: case IPOPT_LSRR:
963: case IPOPT_SSRR:
1.47 cjs 964: if (ip_allowsrcrt == 0) {
965: type = ICMP_UNREACH;
966: code = ICMP_UNREACH_NET_PROHIB;
967: goto bad;
968: }
1.1 cgd 969: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
970: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
971: goto bad;
972: }
973: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 974: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 975: if (ia == 0) {
976: if (opt == IPOPT_SSRR) {
977: type = ICMP_UNREACH;
978: code = ICMP_UNREACH_SRCFAIL;
979: goto bad;
980: }
981: /*
982: * Loose routing, and not at next destination
983: * yet; nothing to do except forward.
984: */
985: break;
986: }
987: off--; /* 0 origin */
988: if (off > optlen - sizeof(struct in_addr)) {
989: /*
990: * End of source route. Should be for us.
991: */
992: save_rte(cp, ip->ip_src);
993: break;
994: }
995: /*
996: * locate outgoing interface
997: */
998: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
999: sizeof(ipaddr.sin_addr));
1000: if (opt == IPOPT_SSRR) {
1001: #define INA struct in_ifaddr *
1002: #define SA struct sockaddr *
1.29 mrg 1003: ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1 cgd 1004: } else
1005: ia = ip_rtaddr(ipaddr.sin_addr);
1006: if (ia == 0) {
1007: type = ICMP_UNREACH;
1008: code = ICMP_UNREACH_SRCFAIL;
1009: goto bad;
1010: }
1011: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 1012: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1013: (caddr_t)(cp + off), sizeof(struct in_addr));
1014: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 1015: /*
1016: * Let ip_intr's mcast routing check handle mcast pkts
1017: */
1.18 mycroft 1018: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 1019: break;
1020:
1021: case IPOPT_RR:
1022: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1023: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1024: goto bad;
1025: }
1026: /*
1027: * If no space remains, ignore.
1028: */
1029: off--; /* 0 origin */
1030: if (off > optlen - sizeof(struct in_addr))
1031: break;
1032: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
1033: sizeof(ipaddr.sin_addr));
1034: /*
1035: * locate outgoing interface; if we're the destination,
1036: * use the incoming interface (should be same).
1037: */
1038: if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1039: (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1040: type = ICMP_UNREACH;
1041: code = ICMP_UNREACH_HOST;
1042: goto bad;
1043: }
1.20 mycroft 1044: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1045: (caddr_t)(cp + off), sizeof(struct in_addr));
1046: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1047: break;
1048:
1049: case IPOPT_TS:
1050: code = cp - (u_char *)ip;
1051: ipt = (struct ip_timestamp *)cp;
1052: if (ipt->ipt_len < 5)
1053: goto bad;
1.15 cgd 1054: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 1055: if (++ipt->ipt_oflw == 0)
1056: goto bad;
1057: break;
1058: }
1059: sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
1060: switch (ipt->ipt_flg) {
1061:
1062: case IPOPT_TS_TSONLY:
1063: break;
1064:
1065: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1066: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1067: sizeof(struct in_addr) > ipt->ipt_len)
1068: goto bad;
1.13 mycroft 1069: ipaddr.sin_addr = dst;
1070: ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1071: m->m_pkthdr.rcvif);
1072: if (ia == 0)
1073: continue;
1.20 mycroft 1074: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1075: (caddr_t)sin, sizeof(struct in_addr));
1076: ipt->ipt_ptr += sizeof(struct in_addr);
1077: break;
1078:
1079: case IPOPT_TS_PRESPEC:
1.66 thorpej 1080: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1081: sizeof(struct in_addr) > ipt->ipt_len)
1082: goto bad;
1083: bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
1084: sizeof(struct in_addr));
1085: if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1086: continue;
1087: ipt->ipt_ptr += sizeof(struct in_addr);
1088: break;
1089:
1090: default:
1091: goto bad;
1092: }
1093: ntime = iptime();
1094: bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
1095: sizeof(n_time));
1096: ipt->ipt_ptr += sizeof(n_time);
1097: }
1098: }
1099: if (forward) {
1.26 thorpej 1100: if (ip_forwsrcrt == 0) {
1101: type = ICMP_UNREACH;
1102: code = ICMP_UNREACH_SRCFAIL;
1103: goto bad;
1104: }
1.1 cgd 1105: ip_forward(m, 1);
1106: return (1);
1.13 mycroft 1107: }
1108: return (0);
1.1 cgd 1109: bad:
1.13 mycroft 1110: icmp_error(m, type, code, 0, 0);
1111: ipstat.ips_badoptions++;
1.1 cgd 1112: return (1);
1113: }
1114:
1115: /*
1116: * Given address of next destination (final or next hop),
1117: * return internet address info of interface to be used to get there.
1118: */
1119: struct in_ifaddr *
1120: ip_rtaddr(dst)
1121: struct in_addr dst;
1122: {
1123: register struct sockaddr_in *sin;
1124:
1.19 mycroft 1125: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1126:
1.35 mycroft 1127: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1128: if (ipforward_rt.ro_rt) {
1129: RTFREE(ipforward_rt.ro_rt);
1130: ipforward_rt.ro_rt = 0;
1131: }
1132: sin->sin_family = AF_INET;
1133: sin->sin_len = sizeof(*sin);
1134: sin->sin_addr = dst;
1135:
1136: rtalloc(&ipforward_rt);
1137: }
1138: if (ipforward_rt.ro_rt == 0)
1139: return ((struct in_ifaddr *)0);
1.19 mycroft 1140: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1141: }
1142:
1143: /*
1144: * Save incoming source route for use in replies,
1145: * to be picked up later by ip_srcroute if the receiver is interested.
1146: */
1.13 mycroft 1147: void
1.1 cgd 1148: save_rte(option, dst)
1149: u_char *option;
1150: struct in_addr dst;
1151: {
1152: unsigned olen;
1153:
1154: olen = option[IPOPT_OLEN];
1155: #ifdef DIAGNOSTIC
1156: if (ipprintfs)
1.39 christos 1157: printf("save_rte: olen %d\n", olen);
1.82.2.2.4.1 itojun 1158: #endif /* 0 */
1.1 cgd 1159: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1160: return;
1161: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1162: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1163: ip_srcrt.dst = dst;
1164: }
1165:
1166: /*
1167: * Retrieve incoming source route for use in replies,
1168: * in the same form used by setsockopt.
1169: * The first hop is placed before the options, will be removed later.
1170: */
1171: struct mbuf *
1172: ip_srcroute()
1173: {
1174: register struct in_addr *p, *q;
1175: register struct mbuf *m;
1176:
1177: if (ip_nhops == 0)
1178: return ((struct mbuf *)0);
1179: m = m_get(M_DONTWAIT, MT_SOOPTS);
1180: if (m == 0)
1181: return ((struct mbuf *)0);
1182:
1.13 mycroft 1183: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1184:
1185: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1186: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1187: OPTSIZ;
1188: #ifdef DIAGNOSTIC
1189: if (ipprintfs)
1.39 christos 1190: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1191: #endif
1192:
1193: /*
1194: * First save first hop for return route
1195: */
1196: p = &ip_srcrt.route[ip_nhops - 1];
1197: *(mtod(m, struct in_addr *)) = *p--;
1198: #ifdef DIAGNOSTIC
1199: if (ipprintfs)
1.39 christos 1200: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1201: #endif
1202:
1203: /*
1204: * Copy option fields and padding (nop) to mbuf.
1205: */
1206: ip_srcrt.nop = IPOPT_NOP;
1207: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1208: bcopy((caddr_t)&ip_srcrt.nop,
1209: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1210: q = (struct in_addr *)(mtod(m, caddr_t) +
1211: sizeof(struct in_addr) + OPTSIZ);
1212: #undef OPTSIZ
1213: /*
1214: * Record return path as an IP source route,
1215: * reversing the path (pointers are now aligned).
1216: */
1217: while (p >= ip_srcrt.route) {
1218: #ifdef DIAGNOSTIC
1219: if (ipprintfs)
1.39 christos 1220: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1221: #endif
1222: *q++ = *p--;
1223: }
1224: /*
1225: * Last hop goes to final destination.
1226: */
1227: *q = ip_srcrt.dst;
1228: #ifdef DIAGNOSTIC
1229: if (ipprintfs)
1.39 christos 1230: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1231: #endif
1232: return (m);
1233: }
1234:
1235: /*
1236: * Strip out IP options, at higher
1237: * level protocol in the kernel.
1238: * Second argument is buffer to which options
1239: * will be moved, and return value is their length.
1240: * XXX should be deleted; last arg currently ignored.
1241: */
1.8 mycroft 1242: void
1.1 cgd 1243: ip_stripoptions(m, mopt)
1244: register struct mbuf *m;
1245: struct mbuf *mopt;
1246: {
1247: register int i;
1248: struct ip *ip = mtod(m, struct ip *);
1249: register caddr_t opts;
1250: int olen;
1251:
1.79 mycroft 1252: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1253: opts = (caddr_t)(ip + 1);
1254: i = m->m_len - (sizeof (struct ip) + olen);
1255: bcopy(opts + olen, opts, (unsigned)i);
1256: m->m_len -= olen;
1257: if (m->m_flags & M_PKTHDR)
1258: m->m_pkthdr.len -= olen;
1.79 mycroft 1259: ip->ip_len -= olen;
1260: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1261: }
1262:
1.23 mycroft 1263: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1264: 0, 0, 0, 0,
1265: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1266: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1267: EMSGSIZE, EHOSTUNREACH, 0, 0,
1268: 0, 0, 0, 0,
1269: ENOPROTOOPT
1270: };
1271:
1272: /*
1273: * Forward a packet. If some error occurs return the sender
1274: * an icmp packet. Note we can't always generate a meaningful
1275: * icmp message because icmp doesn't have a large enough repertoire
1276: * of codes and types.
1277: *
1278: * If not forwarding, just drop the packet. This could be confusing
1279: * if ipforwarding was zero but some routing protocol was advancing
1280: * us as a gateway to somewhere. However, we must let the routing
1281: * protocol deal with that.
1282: *
1283: * The srcrt parameter indicates whether the packet is being forwarded
1284: * via a source route.
1285: */
1.13 mycroft 1286: void
1.1 cgd 1287: ip_forward(m, srcrt)
1288: struct mbuf *m;
1289: int srcrt;
1290: {
1291: register struct ip *ip = mtod(m, struct ip *);
1292: register struct sockaddr_in *sin;
1293: register struct rtentry *rt;
1.28 christos 1294: int error, type = 0, code = 0;
1.1 cgd 1295: struct mbuf *mcopy;
1.13 mycroft 1296: n_long dest;
1297: struct ifnet *destifp;
1.82.2.2.4.1 itojun 1298: #ifdef IPSEC
1299: struct ifnet dummyifp;
1300: #endif
1.1 cgd 1301:
1.13 mycroft 1302: dest = 0;
1.1 cgd 1303: #ifdef DIAGNOSTIC
1304: if (ipprintfs)
1.70 thorpej 1305: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1306: ntohl(ip->ip_src.s_addr),
1307: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1308: #endif
1309: if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
1310: ipstat.ips_cantforward++;
1311: m_freem(m);
1312: return;
1313: }
1314: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1315: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1316: return;
1317: }
1318: ip->ip_ttl -= IPTTLDEC;
1319:
1.19 mycroft 1320: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1321: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1322: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1323: if (ipforward_rt.ro_rt) {
1324: RTFREE(ipforward_rt.ro_rt);
1325: ipforward_rt.ro_rt = 0;
1326: }
1327: sin->sin_family = AF_INET;
1.35 mycroft 1328: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1329: sin->sin_addr = ip->ip_dst;
1330:
1331: rtalloc(&ipforward_rt);
1332: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1333: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1334: return;
1335: }
1336: rt = ipforward_rt.ro_rt;
1337: }
1338:
1339: /*
1.34 mycroft 1340: * Save at most 68 bytes of the packet in case
1.1 cgd 1341: * we need to generate an ICMP message to the src.
1342: */
1.34 mycroft 1343: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1344:
1345: /*
1346: * If forwarding packet using same interface that it came in on,
1347: * perhaps should send a redirect to sender to shortcut a hop.
1348: * Only send redirect if source is sending directly to us,
1349: * and if packet was not source routed (or has any options).
1350: * Also, don't send redirect if forwarding using a default route
1351: * or a route modified by a redirect.
1352: */
1353: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1354: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1355: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1356: ipsendredirects && !srcrt) {
1.19 mycroft 1357: if (rt->rt_ifa &&
1358: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1359: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1360: if (rt->rt_flags & RTF_GATEWAY)
1361: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1362: else
1363: dest = ip->ip_dst.s_addr;
1364: /*
1365: * Router requirements says to only send host
1366: * redirects.
1367: */
1368: type = ICMP_REDIRECT;
1369: code = ICMP_REDIRECT_HOST;
1.1 cgd 1370: #ifdef DIAGNOSTIC
1.77 thorpej 1371: if (ipprintfs)
1372: printf("redirect (%d) to %x\n", code,
1373: (u_int32_t)dest);
1.1 cgd 1374: #endif
1375: }
1376: }
1377:
1.82.2.2.4.1 itojun 1378: #ifdef IPSEC
1379: m->m_pkthdr.rcvif = NULL;
1380: #endif /*IPSEC*/
1.27 thorpej 1381: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1382: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1383: if (error)
1384: ipstat.ips_cantforward++;
1385: else {
1386: ipstat.ips_forward++;
1387: if (type)
1388: ipstat.ips_redirectsent++;
1389: else {
1.63 matt 1390: if (mcopy) {
1391: #ifdef GATEWAY
1.64 thorpej 1392: if (mcopy->m_flags & M_CANFASTFWD)
1393: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1394: #endif
1.1 cgd 1395: m_freem(mcopy);
1.63 matt 1396: }
1.1 cgd 1397: return;
1398: }
1399: }
1400: if (mcopy == NULL)
1401: return;
1.13 mycroft 1402: destifp = NULL;
1403:
1.1 cgd 1404: switch (error) {
1405:
1406: case 0: /* forwarded, but need redirect */
1407: /* type, code set above */
1408: break;
1409:
1410: case ENETUNREACH: /* shouldn't happen, checked above */
1411: case EHOSTUNREACH:
1412: case ENETDOWN:
1413: case EHOSTDOWN:
1414: default:
1415: type = ICMP_UNREACH;
1416: code = ICMP_UNREACH_HOST;
1417: break;
1418:
1419: case EMSGSIZE:
1420: type = ICMP_UNREACH;
1421: code = ICMP_UNREACH_NEEDFRAG;
1.82.2.2.4.1 itojun 1422: #ifndef IPSEC
1.13 mycroft 1423: if (ipforward_rt.ro_rt)
1424: destifp = ipforward_rt.ro_rt->rt_ifp;
1.82.2.2.4.1 itojun 1425: #else
1426: /*
1427: * If the packet is routed over IPsec tunnel, tell the
1428: * originator the tunnel MTU.
1429: * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1430: * XXX quickhack!!!
1431: */
1432: if (ipforward_rt.ro_rt) {
1433: struct secpolicy *sp;
1434: int ipsecerror;
1435: int ipsechdr;
1436: struct route *ro;
1437:
1438: sp = ipsec4_getpolicybyaddr(mcopy,
1.82.2.2.4.3! itojun 1439: IPSEC_DIR_OUTBOUND,
! 1440: IP_FORWARDING,
! 1441: &ipsecerror);
1.82.2.2.4.1 itojun 1442:
1443: if (sp == NULL)
1444: destifp = ipforward_rt.ro_rt->rt_ifp;
1445: else {
1446: /* count IPsec header size */
1.82.2.2.4.3! itojun 1447: ipsechdr = ipsec4_hdrsiz(mcopy,
! 1448: IPSEC_DIR_OUTBOUND,
! 1449: NULL);
1.82.2.2.4.1 itojun 1450:
1451: /*
1452: * find the correct route for outer IPv4
1453: * header, compute tunnel MTU.
1454: *
1455: * XXX BUG ALERT
1456: * The "dummyifp" code relies upon the fact
1457: * that icmp_error() touches only ifp->if_mtu.
1458: */
1459: /*XXX*/
1460: destifp = NULL;
1461: if (sp->req != NULL
1.82.2.2.4.3! itojun 1462: && sp->req->sav != NULL
! 1463: && sp->req->sav->sah != NULL) {
! 1464: ro = &sp->req->sav->sah->sa_route;
1.82.2.2.4.1 itojun 1465: if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1466: dummyifp.if_mtu =
1467: ro->ro_rt->rt_ifp->if_mtu;
1468: dummyifp.if_mtu -= ipsechdr;
1469: destifp = &dummyifp;
1470: }
1471: }
1472:
1473: key_freesp(sp);
1474: }
1475: }
1476: #endif /*IPSEC*/
1.1 cgd 1477: ipstat.ips_cantfrag++;
1478: break;
1479:
1480: case ENOBUFS:
1481: type = ICMP_SOURCEQUENCH;
1482: code = 0;
1483: break;
1484: }
1.13 mycroft 1485: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1486: }
1487:
1488: void
1489: ip_savecontrol(inp, mp, ip, m)
1490: register struct inpcb *inp;
1491: register struct mbuf **mp;
1492: register struct ip *ip;
1493: register struct mbuf *m;
1494: {
1495:
1496: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1497: struct timeval tv;
1498:
1499: microtime(&tv);
1500: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1501: SCM_TIMESTAMP, SOL_SOCKET);
1502: if (*mp)
1503: mp = &(*mp)->m_next;
1504: }
1505: if (inp->inp_flags & INP_RECVDSTADDR) {
1506: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1507: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1508: if (*mp)
1509: mp = &(*mp)->m_next;
1510: }
1511: #ifdef notyet
1512: /*
1513: * XXX
1514: * Moving these out of udp_input() made them even more broken
1515: * than they already were.
1516: * - fenner@parc.xerox.com
1517: */
1518: /* options were tossed already */
1519: if (inp->inp_flags & INP_RECVOPTS) {
1520: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1521: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1522: if (*mp)
1523: mp = &(*mp)->m_next;
1524: }
1525: /* ip_srcroute doesn't do what we want here, need to fix */
1526: if (inp->inp_flags & INP_RECVRETOPTS) {
1527: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1528: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1529: if (*mp)
1530: mp = &(*mp)->m_next;
1531: }
1532: #endif
1533: if (inp->inp_flags & INP_RECVIF) {
1534: struct sockaddr_dl sdl;
1535:
1536: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1537: sdl.sdl_family = AF_LINK;
1538: sdl.sdl_index = m->m_pkthdr.rcvif ?
1539: m->m_pkthdr.rcvif->if_index : 0;
1540: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1541: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1542: IP_RECVIF, IPPROTO_IP);
1543: if (*mp)
1544: mp = &(*mp)->m_next;
1545: }
1.13 mycroft 1546: }
1547:
1548: int
1549: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1550: int *name;
1551: u_int namelen;
1552: void *oldp;
1553: size_t *oldlenp;
1554: void *newp;
1555: size_t newlen;
1556: {
1.52 thorpej 1557: extern int subnetsarelocal;
1558:
1.54 lukem 1559: int error, old;
1560:
1.13 mycroft 1561: /* All sysctl names at this level are terminal. */
1562: if (namelen != 1)
1563: return (ENOTDIR);
1564:
1565: switch (name[0]) {
1566: case IPCTL_FORWARDING:
1567: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1568: case IPCTL_SENDREDIRECTS:
1569: return (sysctl_int(oldp, oldlenp, newp, newlen,
1570: &ipsendredirects));
1571: case IPCTL_DEFTTL:
1572: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1573: #ifdef notyet
1574: case IPCTL_DEFMTU:
1575: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1576: #endif
1.26 thorpej 1577: case IPCTL_FORWSRCRT:
1.47 cjs 1578: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1579: if (securelevel > 0)
1.46 cjs 1580: return (sysctl_rdint(oldp, oldlenp, newp,
1581: ip_forwsrcrt));
1582: else
1583: return (sysctl_int(oldp, oldlenp, newp, newlen,
1584: &ip_forwsrcrt));
1.27 thorpej 1585: case IPCTL_DIRECTEDBCAST:
1586: return (sysctl_int(oldp, oldlenp, newp, newlen,
1587: &ip_directedbcast));
1.47 cjs 1588: case IPCTL_ALLOWSRCRT:
1589: return (sysctl_int(oldp, oldlenp, newp, newlen,
1590: &ip_allowsrcrt));
1.52 thorpej 1591: case IPCTL_SUBNETSARELOCAL:
1592: return (sysctl_int(oldp, oldlenp, newp, newlen,
1593: &subnetsarelocal));
1.53 kml 1594: case IPCTL_MTUDISC:
1.60 kml 1595: error = sysctl_int(oldp, oldlenp, newp, newlen,
1596: &ip_mtudisc);
1597: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1598: ip_mtudisc_timeout_q =
1599: rt_timer_queue_create(ip_mtudisc_timeout);
1600: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1601: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1602: ip_mtudisc_timeout_q = NULL;
1603: }
1604: return error;
1.54 lukem 1605: case IPCTL_ANONPORTMIN:
1606: old = anonportmin;
1607: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1608: if (anonportmin >= anonportmax || anonportmin > 65535
1609: #ifndef IPNOPRIVPORTS
1610: || anonportmin < IPPORT_RESERVED
1611: #endif
1612: ) {
1613: anonportmin = old;
1614: return (EINVAL);
1615: }
1616: return (error);
1617: case IPCTL_ANONPORTMAX:
1618: old = anonportmax;
1619: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1620: if (anonportmin >= anonportmax || anonportmax > 65535
1621: #ifndef IPNOPRIVPORTS
1622: || anonportmax < IPPORT_RESERVED
1623: #endif
1624: ) {
1625: anonportmax = old;
1626: return (EINVAL);
1627: }
1.60 kml 1628: return (error);
1629: case IPCTL_MTUDISCTIMEOUT:
1630: error = sysctl_int(oldp, oldlenp, newp, newlen,
1631: &ip_mtudisc_timeout);
1632: if (ip_mtudisc_timeout_q != NULL)
1633: rt_timer_queue_change(ip_mtudisc_timeout_q,
1634: ip_mtudisc_timeout);
1.54 lukem 1635: return (error);
1.65 matt 1636: #ifdef GATEWAY
1637: case IPCTL_MAXFLOWS:
1.67 thorpej 1638: {
1639: int s;
1640:
1.65 matt 1641: error = sysctl_int(oldp, oldlenp, newp, newlen,
1642: &ip_maxflows);
1.67 thorpej 1643: s = splsoftnet();
1.65 matt 1644: ipflow_reap(0);
1.67 thorpej 1645: splx(s);
1.65 matt 1646: return (error);
1.67 thorpej 1647: }
1.82.2.2.4.1 itojun 1648: #endif
1649: #if NGIF > 0
1650: case IPCTL_GIF_TTL:
1651: return(sysctl_int(oldp, oldlenp, newp, newlen,
1.82.2.2.4.2 itojun 1652: &ip_gif_ttl));
1.65 matt 1653: #endif
1.13 mycroft 1654: default:
1655: return (EOPNOTSUPP);
1656: }
1657: /* NOTREACHED */
1.1 cgd 1658: }
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