Annotation of src/sys/netinet/ip_input.c, Revision 1.96
1.96 ! thorpej 1: /* $NetBSD: ip_input.c,v 1.95 2000/01/31 14:18:54 itojun Exp $ */
1.89 itojun 2:
3: /*
4: * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: * 3. Neither the name of the project nor the names of its contributors
16: * may be used to endorse or promote products derived from this software
17: * without specific prior written permission.
18: *
19: * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22: * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29: * SUCH DAMAGE.
30: */
1.76 thorpej 31:
32: /*-
33: * Copyright (c) 1998 The NetBSD Foundation, Inc.
34: * All rights reserved.
35: *
36: * This code is derived from software contributed to The NetBSD Foundation
37: * by Public Access Networks Corporation ("Panix"). It was developed under
38: * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
39: *
40: * Redistribution and use in source and binary forms, with or without
41: * modification, are permitted provided that the following conditions
42: * are met:
43: * 1. Redistributions of source code must retain the above copyright
44: * notice, this list of conditions and the following disclaimer.
45: * 2. Redistributions in binary form must reproduce the above copyright
46: * notice, this list of conditions and the following disclaimer in the
47: * documentation and/or other materials provided with the distribution.
48: * 3. All advertising materials mentioning features or use of this software
49: * must display the following acknowledgement:
50: * This product includes software developed by the NetBSD
51: * Foundation, Inc. and its contributors.
52: * 4. Neither the name of The NetBSD Foundation nor the names of its
53: * contributors may be used to endorse or promote products derived
54: * from this software without specific prior written permission.
55: *
56: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
57: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
58: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
59: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
60: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
61: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
62: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
63: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
64: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
65: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
66: * POSSIBILITY OF SUCH DAMAGE.
67: */
1.14 cgd 68:
1.1 cgd 69: /*
1.13 mycroft 70: * Copyright (c) 1982, 1986, 1988, 1993
71: * The Regents of the University of California. All rights reserved.
1.1 cgd 72: *
73: * Redistribution and use in source and binary forms, with or without
74: * modification, are permitted provided that the following conditions
75: * are met:
76: * 1. Redistributions of source code must retain the above copyright
77: * notice, this list of conditions and the following disclaimer.
78: * 2. Redistributions in binary form must reproduce the above copyright
79: * notice, this list of conditions and the following disclaimer in the
80: * documentation and/or other materials provided with the distribution.
81: * 3. All advertising materials mentioning features or use of this software
82: * must display the following acknowledgement:
83: * This product includes software developed by the University of
84: * California, Berkeley and its contributors.
85: * 4. Neither the name of the University nor the names of its contributors
86: * may be used to endorse or promote products derived from this software
87: * without specific prior written permission.
88: *
89: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
90: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
91: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
92: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
93: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
94: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
95: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
96: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
97: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
98: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
99: * SUCH DAMAGE.
100: *
1.14 cgd 101: * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
1.1 cgd 102: */
1.55 scottr 103:
1.62 matt 104: #include "opt_gateway.h"
1.69 mrg 105: #include "opt_pfil_hooks.h"
1.91 thorpej 106: #include "opt_ipsec.h"
1.55 scottr 107: #include "opt_mrouting.h"
1.1 cgd 108:
1.5 mycroft 109: #include <sys/param.h>
110: #include <sys/systm.h>
111: #include <sys/malloc.h>
112: #include <sys/mbuf.h>
113: #include <sys/domain.h>
114: #include <sys/protosw.h>
115: #include <sys/socket.h>
1.44 thorpej 116: #include <sys/socketvar.h>
1.5 mycroft 117: #include <sys/errno.h>
118: #include <sys/time.h>
119: #include <sys/kernel.h>
1.28 christos 120: #include <sys/proc.h>
1.72 thorpej 121: #include <sys/pool.h>
1.28 christos 122:
123: #include <vm/vm.h>
124: #include <sys/sysctl.h>
1.1 cgd 125:
1.5 mycroft 126: #include <net/if.h>
1.44 thorpej 127: #include <net/if_dl.h>
1.5 mycroft 128: #include <net/route.h>
1.45 mrg 129: #include <net/pfil.h>
1.1 cgd 130:
1.5 mycroft 131: #include <netinet/in.h>
132: #include <netinet/in_systm.h>
133: #include <netinet/ip.h>
134: #include <netinet/in_pcb.h>
135: #include <netinet/in_var.h>
136: #include <netinet/ip_var.h>
137: #include <netinet/ip_icmp.h>
1.89 itojun 138: /* just for gif_ttl */
139: #include <netinet/in_gif.h>
140: #include "gif.h"
141:
142: #ifdef IPSEC
143: #include <netinet6/ipsec.h>
144: #include <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:
1.1 cgd 196: extern struct domain inetdomain;
197: extern struct protosw inetsw[];
198: u_char ip_protox[IPPROTO_MAX];
199: int ipqmaxlen = IFQ_MAXLEN;
1.22 mycroft 200: struct in_ifaddrhead in_ifaddr;
1.57 tls 201: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.13 mycroft 202: struct ifqueue ipintrq;
1.63 matt 203: struct ipstat ipstat;
204: u_int16_t ip_id;
205: int ip_defttl;
1.75 thorpej 206:
1.63 matt 207: struct ipqhead ipq;
1.75 thorpej 208: int ipq_locked;
209:
210: static __inline int ipq_lock_try __P((void));
211: static __inline void ipq_unlock __P((void));
212:
213: static __inline int
214: ipq_lock_try()
215: {
216: int s;
217:
218: s = splimp();
219: if (ipq_locked) {
220: splx(s);
221: return (0);
222: }
223: ipq_locked = 1;
224: splx(s);
225: return (1);
226: }
227:
228: static __inline void
229: ipq_unlock()
230: {
231: int s;
232:
233: s = splimp();
234: ipq_locked = 0;
235: splx(s);
236: }
237:
238: #ifdef DIAGNOSTIC
239: #define IPQ_LOCK() \
240: do { \
241: if (ipq_lock_try() == 0) { \
242: printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
243: panic("ipq_lock"); \
244: } \
245: } while (0)
246: #define IPQ_LOCK_CHECK() \
247: do { \
248: if (ipq_locked == 0) { \
249: printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
250: panic("ipq lock check"); \
251: } \
252: } while (0)
253: #else
254: #define IPQ_LOCK() (void) ipq_lock_try()
255: #define IPQ_LOCK_CHECK() /* nothing */
256: #endif
257:
258: #define IPQ_UNLOCK() ipq_unlock()
1.1 cgd 259:
1.72 thorpej 260: struct pool ipqent_pool;
261:
1.1 cgd 262: /*
263: * We need to save the IP options in case a protocol wants to respond
264: * to an incoming packet over the same route if the packet got here
265: * using IP source routing. This allows connection establishment and
266: * maintenance when the remote end is on a network that is not known
267: * to us.
268: */
269: int ip_nhops = 0;
270: static struct ip_srcrt {
271: struct in_addr dst; /* final destination */
272: char nop; /* one NOP to align */
273: char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
274: struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
275: } ip_srcrt;
276:
1.13 mycroft 277: static void save_rte __P((u_char *, struct in_addr));
1.35 mycroft 278:
1.1 cgd 279: /*
280: * IP initialization: fill in IP protocol switch table.
281: * All protocols not implemented in kernel go to raw IP protocol handler.
282: */
1.8 mycroft 283: void
1.1 cgd 284: ip_init()
285: {
286: register struct protosw *pr;
287: register int i;
288:
1.72 thorpej 289: pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
290: 0, NULL, NULL, M_IPQ);
291:
1.1 cgd 292: pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
293: if (pr == 0)
294: panic("ip_init");
295: for (i = 0; i < IPPROTO_MAX; i++)
296: ip_protox[i] = pr - inetsw;
297: for (pr = inetdomain.dom_protosw;
298: pr < inetdomain.dom_protoswNPROTOSW; pr++)
299: if (pr->pr_domain->dom_family == PF_INET &&
300: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
301: ip_protox[pr->pr_protocol] = pr - inetsw;
1.25 cgd 302: LIST_INIT(&ipq);
1.1 cgd 303: ip_id = time.tv_sec & 0xffff;
304: ipintrq.ifq_maxlen = ipqmaxlen;
1.22 mycroft 305: TAILQ_INIT(&in_ifaddr);
1.57 tls 306: in_ifaddrhashtbl =
307: hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash);
1.60 kml 308: if (ip_mtudisc != 0)
309: ip_mtudisc_timeout_q =
310: rt_timer_queue_create(ip_mtudisc_timeout);
1.73 thorpej 311: #ifdef GATEWAY
312: ipflow_init();
313: #endif
1.1 cgd 314: }
315:
316: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
317: struct route ipforward_rt;
318:
319: /*
1.89 itojun 320: * IP software interrupt routine
321: */
322: void
323: ipintr()
324: {
325: int s;
326: struct mbuf *m;
327:
328: while (1) {
329: s = splimp();
330: IF_DEQUEUE(&ipintrq, m);
331: splx(s);
332: if (m == 0)
333: return;
334: ip_input(m);
335: }
336: }
337:
338: /*
1.1 cgd 339: * Ip input routine. Checksum and byte swap header. If fragmented
340: * try to reassemble. Process options. Pass to next level.
341: */
1.8 mycroft 342: void
1.89 itojun 343: ip_input(struct mbuf *m)
1.1 cgd 344: {
1.33 mrg 345: register struct ip *ip = NULL;
1.1 cgd 346: register struct ipq *fp;
347: register struct in_ifaddr *ia;
1.57 tls 348: register struct ifaddr *ifa;
1.25 cgd 349: struct ipqent *ipqe;
1.89 itojun 350: int hlen = 0, mff, len;
1.36 mrg 351: #ifdef PFIL_HOOKS
1.33 mrg 352: struct packet_filter_hook *pfh;
353: struct mbuf *m0;
1.43 mrg 354: int rv;
1.36 mrg 355: #endif /* PFIL_HOOKS */
1.1 cgd 356:
357: #ifdef DIAGNOSTIC
358: if ((m->m_flags & M_PKTHDR) == 0)
359: panic("ipintr no HDR");
360: #endif
1.89 itojun 361: #ifdef IPSEC
362: /*
363: * should the inner packet be considered authentic?
364: * see comment in ah4_input().
365: */
366: if (m) {
367: m->m_flags &= ~M_AUTHIPHDR;
368: m->m_flags &= ~M_AUTHIPDGM;
369: }
370: #endif
1.1 cgd 371: /*
372: * If no IP addresses have been set yet but the interfaces
373: * are receiving, can't do anything with incoming packets yet.
374: */
1.22 mycroft 375: if (in_ifaddr.tqh_first == 0)
1.1 cgd 376: goto bad;
377: ipstat.ips_total++;
378: if (m->m_len < sizeof (struct ip) &&
379: (m = m_pullup(m, sizeof (struct ip))) == 0) {
380: ipstat.ips_toosmall++;
1.89 itojun 381: return;
1.1 cgd 382: }
383: ip = mtod(m, struct ip *);
1.13 mycroft 384: if (ip->ip_v != IPVERSION) {
385: ipstat.ips_badvers++;
386: goto bad;
387: }
1.1 cgd 388: hlen = ip->ip_hl << 2;
389: if (hlen < sizeof(struct ip)) { /* minimum header length */
390: ipstat.ips_badhlen++;
391: goto bad;
392: }
393: if (hlen > m->m_len) {
394: if ((m = m_pullup(m, hlen)) == 0) {
395: ipstat.ips_badhlen++;
1.89 itojun 396: return;
1.1 cgd 397: }
398: ip = mtod(m, struct ip *);
399: }
1.85 hwr 400: /*
401: * we drop packets that have a multicast address as source
402: * as wanted by rfc 1112
403: */
404: if (IN_MULTICAST(ip->ip_src.s_addr)) {
405: goto bad;
406: }
407:
1.78 mycroft 408: if (in_cksum(m, hlen) != 0) {
1.1 cgd 409: ipstat.ips_badsum++;
410: goto bad;
411: }
412:
413: /*
414: * Convert fields to host representation.
415: */
416: NTOHS(ip->ip_len);
417: NTOHS(ip->ip_off);
1.35 mycroft 418: len = ip->ip_len;
1.81 proff 419:
420: /*
421: * Check for additional length bogosity
422: */
1.84 proff 423: if (len < hlen) {
1.81 proff 424: ipstat.ips_badlen++;
425: goto bad;
426: }
1.1 cgd 427:
428: /*
429: * Check that the amount of data in the buffers
430: * is as at least much as the IP header would have us expect.
431: * Trim mbufs if longer than we expect.
432: * Drop packet if shorter than we expect.
433: */
1.35 mycroft 434: if (m->m_pkthdr.len < len) {
1.1 cgd 435: ipstat.ips_tooshort++;
436: goto bad;
437: }
1.35 mycroft 438: if (m->m_pkthdr.len > len) {
1.1 cgd 439: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 440: m->m_len = len;
441: m->m_pkthdr.len = len;
1.1 cgd 442: } else
1.35 mycroft 443: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 444: }
445:
1.94 itojun 446: #ifdef IPSEC
447: /* ipflow (IP fast fowarding) is not compatible with IPsec. */
448: m->m_flags &= ~M_CANFASTFWD;
449: #else
1.64 thorpej 450: /*
451: * Assume that we can create a fast-forward IP flow entry
452: * based on this packet.
453: */
454: m->m_flags |= M_CANFASTFWD;
1.94 itojun 455: #endif
1.64 thorpej 456:
1.36 mrg 457: #ifdef PFIL_HOOKS
1.33 mrg 458: /*
1.64 thorpej 459: * Run through list of hooks for input packets. If there are any
460: * filters which require that additional packets in the flow are
461: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
462: * Note that filters must _never_ set this flag, as another filter
463: * in the list may have previously cleared it.
1.33 mrg 464: */
465: m0 = m;
1.59 mrg 466: for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33 mrg 467: if (pfh->pfil_func) {
1.43 mrg 468: rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
469: if (rv)
1.89 itojun 470: return;
1.68 sommerfe 471: m = m0;
472: if (m == NULL)
1.89 itojun 473: return;
1.68 sommerfe 474: ip = mtod(m, struct ip *);
1.33 mrg 475: }
1.36 mrg 476: #endif /* PFIL_HOOKS */
1.33 mrg 477:
1.1 cgd 478: /*
479: * Process options and, if not destined for us,
480: * ship it on. ip_dooptions returns 1 when an
481: * error was detected (causing an icmp message
482: * to be sent and the original packet to be freed).
483: */
484: ip_nhops = 0; /* for source routed packets */
485: if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.89 itojun 486: return;
1.1 cgd 487:
488: /*
489: * Check our list of addresses, to see if the packet is for us.
490: */
1.57 tls 491: INADDR_TO_IA(ip->ip_dst, ia);
1.86 thorpej 492: if (ia != NULL)
493: goto ours;
1.57 tls 494: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
495: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
496: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
497: if (ifa->ifa_addr->sa_family != AF_INET) continue;
498: ia = ifatoia(ifa);
1.35 mycroft 499: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
500: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 501: /*
502: * Look for all-0's host part (old broadcast addr),
503: * either for subnet or net.
504: */
505: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 506: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 507: goto ours;
1.57 tls 508: /*
509: * An interface with IP address zero accepts
510: * all packets that arrive on that interface.
511: */
512: if (in_nullhost(ia->ia_addr.sin_addr))
513: goto ours;
1.1 cgd 514: }
515: }
1.18 mycroft 516: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 517: struct in_multi *inm;
518: #ifdef MROUTING
519: extern struct socket *ip_mrouter;
1.10 brezak 520:
521: if (m->m_flags & M_EXT) {
522: if ((m = m_pullup(m, hlen)) == 0) {
523: ipstat.ips_toosmall++;
1.89 itojun 524: return;
1.10 brezak 525: }
526: ip = mtod(m, struct ip *);
527: }
1.4 hpeyerl 528:
529: if (ip_mrouter) {
530: /*
531: * If we are acting as a multicast router, all
532: * incoming multicast packets are passed to the
533: * kernel-level multicast forwarding function.
534: * The packet is returned (relatively) intact; if
535: * ip_mforward() returns a non-zero value, the packet
536: * must be discarded, else it may be accepted below.
537: *
538: * (The IP ident field is put in the same byte order
539: * as expected when ip_mforward() is called from
540: * ip_output().)
541: */
1.13 mycroft 542: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
543: ipstat.ips_cantforward++;
1.4 hpeyerl 544: m_freem(m);
1.89 itojun 545: return;
1.4 hpeyerl 546: }
547:
548: /*
549: * The process-level routing demon needs to receive
550: * all multicast IGMP packets, whether or not this
551: * host belongs to their destination groups.
552: */
553: if (ip->ip_p == IPPROTO_IGMP)
554: goto ours;
1.13 mycroft 555: ipstat.ips_forward++;
1.4 hpeyerl 556: }
557: #endif
558: /*
559: * See if we belong to the destination multicast group on the
560: * arrival interface.
561: */
562: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
563: if (inm == NULL) {
1.13 mycroft 564: ipstat.ips_cantforward++;
1.4 hpeyerl 565: m_freem(m);
1.89 itojun 566: return;
1.4 hpeyerl 567: }
568: goto ours;
569: }
1.19 mycroft 570: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 571: in_nullhost(ip->ip_dst))
1.1 cgd 572: goto ours;
573:
574: /*
575: * Not for us; forward if possible and desirable.
576: */
577: if (ipforwarding == 0) {
578: ipstat.ips_cantforward++;
579: m_freem(m);
580: } else
581: ip_forward(m, 0);
1.89 itojun 582: return;
1.1 cgd 583:
584: ours:
585: /*
586: * If offset or IP_MF are set, must reassemble.
587: * Otherwise, nothing need be done.
588: * (We could look in the reassembly queue to see
589: * if the packet was previously fragmented,
590: * but it's not worth the time; just let them time out.)
591: */
1.37 perry 592: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 593: /*
594: * Look for queue of fragments
595: * of this datagram.
596: */
1.75 thorpej 597: IPQ_LOCK();
1.25 cgd 598: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 599: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 600: in_hosteq(ip->ip_src, fp->ipq_src) &&
601: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 602: ip->ip_p == fp->ipq_p)
603: goto found;
604: fp = 0;
605: found:
606:
607: /*
608: * Adjust ip_len to not reflect header,
1.25 cgd 609: * set ipqe_mff if more fragments are expected,
1.1 cgd 610: * convert offset of this to bytes.
611: */
612: ip->ip_len -= hlen;
1.25 cgd 613: mff = (ip->ip_off & IP_MF) != 0;
614: if (mff) {
1.16 cgd 615: /*
616: * Make sure that fragments have a data length
617: * that's a non-zero multiple of 8 bytes.
618: */
1.17 cgd 619: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 620: ipstat.ips_badfrags++;
1.75 thorpej 621: IPQ_UNLOCK();
1.16 cgd 622: goto bad;
623: }
624: }
1.1 cgd 625: ip->ip_off <<= 3;
626:
627: /*
628: * If datagram marked as having more fragments
629: * or if this is not the first fragment,
630: * attempt reassembly; if it succeeds, proceed.
631: */
1.25 cgd 632: if (mff || ip->ip_off) {
1.1 cgd 633: ipstat.ips_fragments++;
1.72 thorpej 634: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 635: if (ipqe == NULL) {
636: ipstat.ips_rcvmemdrop++;
1.75 thorpej 637: IPQ_UNLOCK();
1.25 cgd 638: goto bad;
639: }
640: ipqe->ipqe_mff = mff;
1.50 thorpej 641: ipqe->ipqe_m = m;
1.25 cgd 642: ipqe->ipqe_ip = ip;
1.50 thorpej 643: m = ip_reass(ipqe, fp);
1.75 thorpej 644: if (m == 0) {
645: IPQ_UNLOCK();
1.89 itojun 646: return;
1.75 thorpej 647: }
1.13 mycroft 648: ipstat.ips_reassembled++;
1.50 thorpej 649: ip = mtod(m, struct ip *);
1.74 thorpej 650: hlen = ip->ip_hl << 2;
1.79 mycroft 651: ip->ip_len += hlen;
1.1 cgd 652: } else
653: if (fp)
654: ip_freef(fp);
1.75 thorpej 655: IPQ_UNLOCK();
1.79 mycroft 656: }
1.1 cgd 657:
658: /*
659: * Switch out to protocol's input routine.
660: */
1.82 aidan 661: #if IFA_STATS
662: ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
663: #endif
1.1 cgd 664: ipstat.ips_delivered++;
1.89 itojun 665: {
666: int off = hlen, nh = ip->ip_p;
667:
668: (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
669: return;
670: }
1.1 cgd 671: bad:
672: m_freem(m);
673: }
674:
675: /*
676: * Take incoming datagram fragment and try to
677: * reassemble it into whole datagram. If a chain for
678: * reassembly of this datagram already exists, then it
679: * is given as fp; otherwise have to make a chain.
680: */
1.50 thorpej 681: struct mbuf *
1.25 cgd 682: ip_reass(ipqe, fp)
683: register struct ipqent *ipqe;
1.1 cgd 684: register struct ipq *fp;
685: {
1.50 thorpej 686: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 687: register struct ipqent *nq, *p, *q;
688: struct ip *ip;
1.1 cgd 689: struct mbuf *t;
1.25 cgd 690: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 691: int i, next;
692:
1.75 thorpej 693: IPQ_LOCK_CHECK();
694:
1.1 cgd 695: /*
696: * Presence of header sizes in mbufs
697: * would confuse code below.
698: */
699: m->m_data += hlen;
700: m->m_len -= hlen;
701:
702: /*
703: * If first fragment to arrive, create a reassembly queue.
704: */
705: if (fp == 0) {
1.50 thorpej 706: MALLOC(fp, struct ipq *, sizeof (struct ipq),
707: M_FTABLE, M_NOWAIT);
708: if (fp == NULL)
1.1 cgd 709: goto dropfrag;
1.25 cgd 710: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 711: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 712: fp->ipq_p = ipqe->ipqe_ip->ip_p;
713: fp->ipq_id = ipqe->ipqe_ip->ip_id;
714: LIST_INIT(&fp->ipq_fragq);
715: fp->ipq_src = ipqe->ipqe_ip->ip_src;
716: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
717: p = NULL;
1.1 cgd 718: goto insert;
719: }
720:
721: /*
722: * Find a segment which begins after this one does.
723: */
1.25 cgd 724: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
725: p = q, q = q->ipqe_q.le_next)
726: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 727: break;
728:
729: /*
730: * If there is a preceding segment, it may provide some of
731: * our data already. If so, drop the data from the incoming
732: * segment. If it provides all of our data, drop us.
733: */
1.25 cgd 734: if (p != NULL) {
735: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
736: ipqe->ipqe_ip->ip_off;
1.1 cgd 737: if (i > 0) {
1.25 cgd 738: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 739: goto dropfrag;
1.50 thorpej 740: m_adj(ipqe->ipqe_m, i);
1.25 cgd 741: ipqe->ipqe_ip->ip_off += i;
742: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 743: }
744: }
745:
746: /*
747: * While we overlap succeeding segments trim them or,
748: * if they are completely covered, dequeue them.
749: */
1.25 cgd 750: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
751: q->ipqe_ip->ip_off; q = nq) {
752: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
753: q->ipqe_ip->ip_off;
754: if (i < q->ipqe_ip->ip_len) {
755: q->ipqe_ip->ip_len -= i;
756: q->ipqe_ip->ip_off += i;
1.50 thorpej 757: m_adj(q->ipqe_m, i);
1.1 cgd 758: break;
759: }
1.25 cgd 760: nq = q->ipqe_q.le_next;
1.50 thorpej 761: m_freem(q->ipqe_m);
1.25 cgd 762: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 763: pool_put(&ipqent_pool, q);
1.1 cgd 764: }
765:
766: insert:
767: /*
768: * Stick new segment in its place;
769: * check for complete reassembly.
770: */
1.25 cgd 771: if (p == NULL) {
772: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
773: } else {
774: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
775: }
1.1 cgd 776: next = 0;
1.25 cgd 777: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
778: p = q, q = q->ipqe_q.le_next) {
779: if (q->ipqe_ip->ip_off != next)
1.1 cgd 780: return (0);
1.25 cgd 781: next += q->ipqe_ip->ip_len;
1.1 cgd 782: }
1.25 cgd 783: if (p->ipqe_mff)
1.1 cgd 784: return (0);
785:
786: /*
1.41 thorpej 787: * Reassembly is complete. Check for a bogus message size and
788: * concatenate fragments.
1.1 cgd 789: */
1.25 cgd 790: q = fp->ipq_fragq.lh_first;
791: ip = q->ipqe_ip;
1.41 thorpej 792: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
793: ipstat.ips_toolong++;
794: ip_freef(fp);
795: return (0);
796: }
1.50 thorpej 797: m = q->ipqe_m;
1.1 cgd 798: t = m->m_next;
799: m->m_next = 0;
800: m_cat(m, t);
1.25 cgd 801: nq = q->ipqe_q.le_next;
1.72 thorpej 802: pool_put(&ipqent_pool, q);
1.25 cgd 803: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 804: t = q->ipqe_m;
1.25 cgd 805: nq = q->ipqe_q.le_next;
1.72 thorpej 806: pool_put(&ipqent_pool, q);
1.1 cgd 807: m_cat(m, t);
808: }
809:
810: /*
811: * Create header for new ip packet by
812: * modifying header of first packet;
813: * dequeue and discard fragment reassembly header.
814: * Make header visible.
815: */
816: ip->ip_len = next;
1.89 itojun 817: ip->ip_ttl = 0; /* xxx */
818: ip->ip_sum = 0;
1.25 cgd 819: ip->ip_src = fp->ipq_src;
820: ip->ip_dst = fp->ipq_dst;
821: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 822: FREE(fp, M_FTABLE);
1.1 cgd 823: m->m_len += (ip->ip_hl << 2);
824: m->m_data -= (ip->ip_hl << 2);
825: /* some debugging cruft by sklower, below, will go away soon */
826: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
827: register int plen = 0;
1.50 thorpej 828: for (t = m; t; t = t->m_next)
829: plen += t->m_len;
830: m->m_pkthdr.len = plen;
1.1 cgd 831: }
1.50 thorpej 832: return (m);
1.1 cgd 833:
834: dropfrag:
835: ipstat.ips_fragdropped++;
836: m_freem(m);
1.72 thorpej 837: pool_put(&ipqent_pool, ipqe);
1.1 cgd 838: return (0);
839: }
840:
841: /*
842: * Free a fragment reassembly header and all
843: * associated datagrams.
844: */
1.8 mycroft 845: void
1.1 cgd 846: ip_freef(fp)
847: struct ipq *fp;
848: {
1.25 cgd 849: register struct ipqent *q, *p;
1.1 cgd 850:
1.75 thorpej 851: IPQ_LOCK_CHECK();
852:
1.25 cgd 853: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
854: p = q->ipqe_q.le_next;
1.50 thorpej 855: m_freem(q->ipqe_m);
1.25 cgd 856: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 857: pool_put(&ipqent_pool, q);
1.1 cgd 858: }
1.25 cgd 859: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 860: FREE(fp, M_FTABLE);
1.1 cgd 861: }
862:
863: /*
864: * IP timer processing;
865: * if a timer expires on a reassembly
866: * queue, discard it.
867: */
1.8 mycroft 868: void
1.1 cgd 869: ip_slowtimo()
870: {
1.25 cgd 871: register struct ipq *fp, *nfp;
1.24 mycroft 872: int s = splsoftnet();
1.1 cgd 873:
1.75 thorpej 874: IPQ_LOCK();
1.25 cgd 875: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
876: nfp = fp->ipq_q.le_next;
877: if (--fp->ipq_ttl == 0) {
1.1 cgd 878: ipstat.ips_fragtimeout++;
1.25 cgd 879: ip_freef(fp);
1.1 cgd 880: }
881: }
1.75 thorpej 882: IPQ_UNLOCK();
1.63 matt 883: #ifdef GATEWAY
884: ipflow_slowtimo();
885: #endif
1.1 cgd 886: splx(s);
887: }
888:
889: /*
890: * Drain off all datagram fragments.
891: */
1.8 mycroft 892: void
1.1 cgd 893: ip_drain()
894: {
895:
1.75 thorpej 896: /*
897: * We may be called from a device's interrupt context. If
898: * the ipq is already busy, just bail out now.
899: */
900: if (ipq_lock_try() == 0)
901: return;
902:
1.25 cgd 903: while (ipq.lh_first != NULL) {
1.1 cgd 904: ipstat.ips_fragdropped++;
1.25 cgd 905: ip_freef(ipq.lh_first);
1.1 cgd 906: }
1.75 thorpej 907:
908: IPQ_UNLOCK();
1.1 cgd 909: }
910:
911: /*
912: * Do option processing on a datagram,
913: * possibly discarding it if bad options are encountered,
914: * or forwarding it if source-routed.
915: * Returns 1 if packet has been forwarded/freed,
916: * 0 if the packet should be processed further.
917: */
1.8 mycroft 918: int
1.1 cgd 919: ip_dooptions(m)
920: struct mbuf *m;
921: {
922: register struct ip *ip = mtod(m, struct ip *);
923: register u_char *cp;
924: register struct ip_timestamp *ipt;
925: register struct in_ifaddr *ia;
926: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13 mycroft 927: struct in_addr *sin, dst;
1.1 cgd 928: n_time ntime;
929:
1.13 mycroft 930: dst = ip->ip_dst;
1.1 cgd 931: cp = (u_char *)(ip + 1);
932: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
933: for (; cnt > 0; cnt -= optlen, cp += optlen) {
934: opt = cp[IPOPT_OPTVAL];
935: if (opt == IPOPT_EOL)
936: break;
937: if (opt == IPOPT_NOP)
938: optlen = 1;
939: else {
940: optlen = cp[IPOPT_OLEN];
941: if (optlen <= 0 || optlen > cnt) {
942: code = &cp[IPOPT_OLEN] - (u_char *)ip;
943: goto bad;
944: }
945: }
946: switch (opt) {
947:
948: default:
949: break;
950:
951: /*
952: * Source routing with record.
953: * Find interface with current destination address.
954: * If none on this machine then drop if strictly routed,
955: * or do nothing if loosely routed.
956: * Record interface address and bring up next address
957: * component. If strictly routed make sure next
958: * address is on directly accessible net.
959: */
960: case IPOPT_LSRR:
961: case IPOPT_SSRR:
1.47 cjs 962: if (ip_allowsrcrt == 0) {
963: type = ICMP_UNREACH;
964: code = ICMP_UNREACH_NET_PROHIB;
965: goto bad;
966: }
1.1 cgd 967: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
968: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
969: goto bad;
970: }
971: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 972: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 973: if (ia == 0) {
974: if (opt == IPOPT_SSRR) {
975: type = ICMP_UNREACH;
976: code = ICMP_UNREACH_SRCFAIL;
977: goto bad;
978: }
979: /*
980: * Loose routing, and not at next destination
981: * yet; nothing to do except forward.
982: */
983: break;
984: }
985: off--; /* 0 origin */
986: if (off > optlen - sizeof(struct in_addr)) {
987: /*
988: * End of source route. Should be for us.
989: */
990: save_rte(cp, ip->ip_src);
991: break;
992: }
993: /*
994: * locate outgoing interface
995: */
996: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
997: sizeof(ipaddr.sin_addr));
1.96 ! thorpej 998: if (opt == IPOPT_SSRR)
! 999: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
! 1000: else
1.1 cgd 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: */
1.96 ! thorpej 1034: if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
! 1035: == NULL &&
! 1036: (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1.1 cgd 1037: type = ICMP_UNREACH;
1038: code = ICMP_UNREACH_HOST;
1039: goto bad;
1040: }
1.20 mycroft 1041: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1042: (caddr_t)(cp + off), sizeof(struct in_addr));
1043: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1044: break;
1045:
1046: case IPOPT_TS:
1047: code = cp - (u_char *)ip;
1048: ipt = (struct ip_timestamp *)cp;
1049: if (ipt->ipt_len < 5)
1050: goto bad;
1.15 cgd 1051: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 1052: if (++ipt->ipt_oflw == 0)
1053: goto bad;
1054: break;
1055: }
1056: sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
1057: switch (ipt->ipt_flg) {
1058:
1059: case IPOPT_TS_TSONLY:
1060: break;
1061:
1062: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1063: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1064: sizeof(struct in_addr) > ipt->ipt_len)
1065: goto bad;
1.13 mycroft 1066: ipaddr.sin_addr = dst;
1.96 ! thorpej 1067: ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
! 1068: m->m_pkthdr.rcvif));
1.13 mycroft 1069: if (ia == 0)
1070: continue;
1.20 mycroft 1071: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1072: (caddr_t)sin, sizeof(struct in_addr));
1073: ipt->ipt_ptr += sizeof(struct in_addr);
1074: break;
1075:
1076: case IPOPT_TS_PRESPEC:
1.66 thorpej 1077: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1078: sizeof(struct in_addr) > ipt->ipt_len)
1079: goto bad;
1080: bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
1081: sizeof(struct in_addr));
1.96 ! thorpej 1082: if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
! 1083: == NULL)
1.1 cgd 1084: continue;
1085: ipt->ipt_ptr += sizeof(struct in_addr);
1086: break;
1087:
1088: default:
1089: goto bad;
1090: }
1091: ntime = iptime();
1092: bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
1093: sizeof(n_time));
1094: ipt->ipt_ptr += sizeof(n_time);
1095: }
1096: }
1097: if (forward) {
1.26 thorpej 1098: if (ip_forwsrcrt == 0) {
1099: type = ICMP_UNREACH;
1100: code = ICMP_UNREACH_SRCFAIL;
1101: goto bad;
1102: }
1.1 cgd 1103: ip_forward(m, 1);
1104: return (1);
1.13 mycroft 1105: }
1106: return (0);
1.1 cgd 1107: bad:
1.13 mycroft 1108: icmp_error(m, type, code, 0, 0);
1109: ipstat.ips_badoptions++;
1.1 cgd 1110: return (1);
1111: }
1112:
1113: /*
1114: * Given address of next destination (final or next hop),
1115: * return internet address info of interface to be used to get there.
1116: */
1117: struct in_ifaddr *
1118: ip_rtaddr(dst)
1119: struct in_addr dst;
1120: {
1121: register struct sockaddr_in *sin;
1122:
1.19 mycroft 1123: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1124:
1.35 mycroft 1125: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1126: if (ipforward_rt.ro_rt) {
1127: RTFREE(ipforward_rt.ro_rt);
1128: ipforward_rt.ro_rt = 0;
1129: }
1130: sin->sin_family = AF_INET;
1131: sin->sin_len = sizeof(*sin);
1132: sin->sin_addr = dst;
1133:
1134: rtalloc(&ipforward_rt);
1135: }
1136: if (ipforward_rt.ro_rt == 0)
1137: return ((struct in_ifaddr *)0);
1.19 mycroft 1138: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1139: }
1140:
1141: /*
1142: * Save incoming source route for use in replies,
1143: * to be picked up later by ip_srcroute if the receiver is interested.
1144: */
1.13 mycroft 1145: void
1.1 cgd 1146: save_rte(option, dst)
1147: u_char *option;
1148: struct in_addr dst;
1149: {
1150: unsigned olen;
1151:
1152: olen = option[IPOPT_OLEN];
1153: #ifdef DIAGNOSTIC
1154: if (ipprintfs)
1.39 christos 1155: printf("save_rte: olen %d\n", olen);
1.89 itojun 1156: #endif /* 0 */
1.1 cgd 1157: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1158: return;
1159: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1160: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1161: ip_srcrt.dst = dst;
1162: }
1163:
1164: /*
1165: * Retrieve incoming source route for use in replies,
1166: * in the same form used by setsockopt.
1167: * The first hop is placed before the options, will be removed later.
1168: */
1169: struct mbuf *
1170: ip_srcroute()
1171: {
1172: register struct in_addr *p, *q;
1173: register struct mbuf *m;
1174:
1175: if (ip_nhops == 0)
1176: return ((struct mbuf *)0);
1177: m = m_get(M_DONTWAIT, MT_SOOPTS);
1178: if (m == 0)
1179: return ((struct mbuf *)0);
1180:
1.13 mycroft 1181: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1182:
1183: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1184: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1185: OPTSIZ;
1186: #ifdef DIAGNOSTIC
1187: if (ipprintfs)
1.39 christos 1188: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1189: #endif
1190:
1191: /*
1192: * First save first hop for return route
1193: */
1194: p = &ip_srcrt.route[ip_nhops - 1];
1195: *(mtod(m, struct in_addr *)) = *p--;
1196: #ifdef DIAGNOSTIC
1197: if (ipprintfs)
1.39 christos 1198: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1199: #endif
1200:
1201: /*
1202: * Copy option fields and padding (nop) to mbuf.
1203: */
1204: ip_srcrt.nop = IPOPT_NOP;
1205: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1206: bcopy((caddr_t)&ip_srcrt.nop,
1207: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1208: q = (struct in_addr *)(mtod(m, caddr_t) +
1209: sizeof(struct in_addr) + OPTSIZ);
1210: #undef OPTSIZ
1211: /*
1212: * Record return path as an IP source route,
1213: * reversing the path (pointers are now aligned).
1214: */
1215: while (p >= ip_srcrt.route) {
1216: #ifdef DIAGNOSTIC
1217: if (ipprintfs)
1.39 christos 1218: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1219: #endif
1220: *q++ = *p--;
1221: }
1222: /*
1223: * Last hop goes to final destination.
1224: */
1225: *q = ip_srcrt.dst;
1226: #ifdef DIAGNOSTIC
1227: if (ipprintfs)
1.39 christos 1228: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1229: #endif
1230: return (m);
1231: }
1232:
1233: /*
1234: * Strip out IP options, at higher
1235: * level protocol in the kernel.
1236: * Second argument is buffer to which options
1237: * will be moved, and return value is their length.
1238: * XXX should be deleted; last arg currently ignored.
1239: */
1.8 mycroft 1240: void
1.1 cgd 1241: ip_stripoptions(m, mopt)
1242: register struct mbuf *m;
1243: struct mbuf *mopt;
1244: {
1245: register int i;
1246: struct ip *ip = mtod(m, struct ip *);
1247: register caddr_t opts;
1248: int olen;
1249:
1.79 mycroft 1250: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1251: opts = (caddr_t)(ip + 1);
1252: i = m->m_len - (sizeof (struct ip) + olen);
1253: bcopy(opts + olen, opts, (unsigned)i);
1254: m->m_len -= olen;
1255: if (m->m_flags & M_PKTHDR)
1256: m->m_pkthdr.len -= olen;
1.79 mycroft 1257: ip->ip_len -= olen;
1258: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1259: }
1260:
1.23 mycroft 1261: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1262: 0, 0, 0, 0,
1263: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1264: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1265: EMSGSIZE, EHOSTUNREACH, 0, 0,
1266: 0, 0, 0, 0,
1267: ENOPROTOOPT
1268: };
1269:
1270: /*
1271: * Forward a packet. If some error occurs return the sender
1272: * an icmp packet. Note we can't always generate a meaningful
1273: * icmp message because icmp doesn't have a large enough repertoire
1274: * of codes and types.
1275: *
1276: * If not forwarding, just drop the packet. This could be confusing
1277: * if ipforwarding was zero but some routing protocol was advancing
1278: * us as a gateway to somewhere. However, we must let the routing
1279: * protocol deal with that.
1280: *
1281: * The srcrt parameter indicates whether the packet is being forwarded
1282: * via a source route.
1283: */
1.13 mycroft 1284: void
1.1 cgd 1285: ip_forward(m, srcrt)
1286: struct mbuf *m;
1287: int srcrt;
1288: {
1289: register struct ip *ip = mtod(m, struct ip *);
1290: register struct sockaddr_in *sin;
1291: register struct rtentry *rt;
1.28 christos 1292: int error, type = 0, code = 0;
1.1 cgd 1293: struct mbuf *mcopy;
1.13 mycroft 1294: n_long dest;
1295: struct ifnet *destifp;
1.89 itojun 1296: #ifdef IPSEC
1297: struct ifnet dummyifp;
1298: #endif
1.1 cgd 1299:
1.13 mycroft 1300: dest = 0;
1.1 cgd 1301: #ifdef DIAGNOSTIC
1302: if (ipprintfs)
1.70 thorpej 1303: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1304: ntohl(ip->ip_src.s_addr),
1305: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1306: #endif
1.93 sommerfe 1307: if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1.1 cgd 1308: ipstat.ips_cantforward++;
1309: m_freem(m);
1310: return;
1311: }
1312: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1313: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1314: return;
1315: }
1316: ip->ip_ttl -= IPTTLDEC;
1317:
1.19 mycroft 1318: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1319: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1320: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1321: if (ipforward_rt.ro_rt) {
1322: RTFREE(ipforward_rt.ro_rt);
1323: ipforward_rt.ro_rt = 0;
1324: }
1325: sin->sin_family = AF_INET;
1.35 mycroft 1326: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1327: sin->sin_addr = ip->ip_dst;
1328:
1329: rtalloc(&ipforward_rt);
1330: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1331: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1332: return;
1333: }
1334: rt = ipforward_rt.ro_rt;
1335: }
1336:
1337: /*
1.34 mycroft 1338: * Save at most 68 bytes of the packet in case
1.1 cgd 1339: * we need to generate an ICMP message to the src.
1340: */
1.34 mycroft 1341: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1342:
1343: /*
1344: * If forwarding packet using same interface that it came in on,
1345: * perhaps should send a redirect to sender to shortcut a hop.
1346: * Only send redirect if source is sending directly to us,
1347: * and if packet was not source routed (or has any options).
1348: * Also, don't send redirect if forwarding using a default route
1349: * or a route modified by a redirect.
1350: */
1351: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1352: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1353: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1354: ipsendredirects && !srcrt) {
1.19 mycroft 1355: if (rt->rt_ifa &&
1356: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1357: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1358: if (rt->rt_flags & RTF_GATEWAY)
1359: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1360: else
1361: dest = ip->ip_dst.s_addr;
1362: /*
1363: * Router requirements says to only send host
1364: * redirects.
1365: */
1366: type = ICMP_REDIRECT;
1367: code = ICMP_REDIRECT_HOST;
1.1 cgd 1368: #ifdef DIAGNOSTIC
1.77 thorpej 1369: if (ipprintfs)
1370: printf("redirect (%d) to %x\n", code,
1371: (u_int32_t)dest);
1.1 cgd 1372: #endif
1373: }
1374: }
1375:
1.89 itojun 1376: #ifdef IPSEC
1377: m->m_pkthdr.rcvif = NULL;
1378: #endif /*IPSEC*/
1.27 thorpej 1379: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1380: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1381: if (error)
1382: ipstat.ips_cantforward++;
1383: else {
1384: ipstat.ips_forward++;
1385: if (type)
1386: ipstat.ips_redirectsent++;
1387: else {
1.63 matt 1388: if (mcopy) {
1389: #ifdef GATEWAY
1.64 thorpej 1390: if (mcopy->m_flags & M_CANFASTFWD)
1391: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1392: #endif
1.1 cgd 1393: m_freem(mcopy);
1.63 matt 1394: }
1.1 cgd 1395: return;
1396: }
1397: }
1398: if (mcopy == NULL)
1399: return;
1.13 mycroft 1400: destifp = NULL;
1401:
1.1 cgd 1402: switch (error) {
1403:
1404: case 0: /* forwarded, but need redirect */
1405: /* type, code set above */
1406: break;
1407:
1408: case ENETUNREACH: /* shouldn't happen, checked above */
1409: case EHOSTUNREACH:
1410: case ENETDOWN:
1411: case EHOSTDOWN:
1412: default:
1413: type = ICMP_UNREACH;
1414: code = ICMP_UNREACH_HOST;
1415: break;
1416:
1417: case EMSGSIZE:
1418: type = ICMP_UNREACH;
1419: code = ICMP_UNREACH_NEEDFRAG;
1.89 itojun 1420: #ifndef IPSEC
1.13 mycroft 1421: if (ipforward_rt.ro_rt)
1422: destifp = ipforward_rt.ro_rt->rt_ifp;
1.89 itojun 1423: #else
1424: /*
1425: * If the packet is routed over IPsec tunnel, tell the
1426: * originator the tunnel MTU.
1427: * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1428: * XXX quickhack!!!
1429: */
1430: if (ipforward_rt.ro_rt) {
1431: struct secpolicy *sp;
1432: int ipsecerror;
1.95 itojun 1433: size_t ipsechdr;
1.89 itojun 1434: struct route *ro;
1435:
1436: sp = ipsec4_getpolicybyaddr(mcopy,
1.95 itojun 1437: IPSEC_DIR_OUTBOUND,
1438: IP_FORWARDING,
1439: &ipsecerror);
1.89 itojun 1440:
1441: if (sp == NULL)
1442: destifp = ipforward_rt.ro_rt->rt_ifp;
1443: else {
1444: /* count IPsec header size */
1.95 itojun 1445: ipsechdr = ipsec4_hdrsiz(mcopy,
1446: IPSEC_DIR_OUTBOUND,
1447: NULL);
1.89 itojun 1448:
1449: /*
1450: * find the correct route for outer IPv4
1451: * header, compute tunnel MTU.
1452: *
1453: * XXX BUG ALERT
1454: * The "dummyifp" code relies upon the fact
1455: * that icmp_error() touches only ifp->if_mtu.
1456: */
1457: /*XXX*/
1458: destifp = NULL;
1459: if (sp->req != NULL
1.95 itojun 1460: && sp->req->sav != NULL
1461: && sp->req->sav->sah != NULL) {
1462: ro = &sp->req->sav->sah->sa_route;
1.89 itojun 1463: if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1464: dummyifp.if_mtu =
1465: ro->ro_rt->rt_ifp->if_mtu;
1466: dummyifp.if_mtu -= ipsechdr;
1467: destifp = &dummyifp;
1468: }
1469: }
1470:
1471: key_freesp(sp);
1472: }
1473: }
1474: #endif /*IPSEC*/
1.1 cgd 1475: ipstat.ips_cantfrag++;
1476: break;
1477:
1478: case ENOBUFS:
1479: type = ICMP_SOURCEQUENCH;
1480: code = 0;
1481: break;
1482: }
1.13 mycroft 1483: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1484: }
1485:
1486: void
1487: ip_savecontrol(inp, mp, ip, m)
1488: register struct inpcb *inp;
1489: register struct mbuf **mp;
1490: register struct ip *ip;
1491: register struct mbuf *m;
1492: {
1493:
1494: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1495: struct timeval tv;
1496:
1497: microtime(&tv);
1498: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1499: SCM_TIMESTAMP, SOL_SOCKET);
1500: if (*mp)
1501: mp = &(*mp)->m_next;
1502: }
1503: if (inp->inp_flags & INP_RECVDSTADDR) {
1504: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1505: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1506: if (*mp)
1507: mp = &(*mp)->m_next;
1508: }
1509: #ifdef notyet
1510: /*
1511: * XXX
1512: * Moving these out of udp_input() made them even more broken
1513: * than they already were.
1514: * - fenner@parc.xerox.com
1515: */
1516: /* options were tossed already */
1517: if (inp->inp_flags & INP_RECVOPTS) {
1518: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1519: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1520: if (*mp)
1521: mp = &(*mp)->m_next;
1522: }
1523: /* ip_srcroute doesn't do what we want here, need to fix */
1524: if (inp->inp_flags & INP_RECVRETOPTS) {
1525: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1526: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1527: if (*mp)
1528: mp = &(*mp)->m_next;
1529: }
1530: #endif
1531: if (inp->inp_flags & INP_RECVIF) {
1532: struct sockaddr_dl sdl;
1533:
1534: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1535: sdl.sdl_family = AF_LINK;
1536: sdl.sdl_index = m->m_pkthdr.rcvif ?
1537: m->m_pkthdr.rcvif->if_index : 0;
1538: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1539: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1540: IP_RECVIF, IPPROTO_IP);
1541: if (*mp)
1542: mp = &(*mp)->m_next;
1543: }
1.13 mycroft 1544: }
1545:
1546: int
1547: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1548: int *name;
1549: u_int namelen;
1550: void *oldp;
1551: size_t *oldlenp;
1552: void *newp;
1553: size_t newlen;
1554: {
1.88 sommerfe 1555: extern int subnetsarelocal, hostzeroisbroadcast;
1.52 thorpej 1556:
1.54 lukem 1557: int error, old;
1558:
1.13 mycroft 1559: /* All sysctl names at this level are terminal. */
1560: if (namelen != 1)
1561: return (ENOTDIR);
1562:
1563: switch (name[0]) {
1564: case IPCTL_FORWARDING:
1565: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1566: case IPCTL_SENDREDIRECTS:
1567: return (sysctl_int(oldp, oldlenp, newp, newlen,
1568: &ipsendredirects));
1569: case IPCTL_DEFTTL:
1570: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1571: #ifdef notyet
1572: case IPCTL_DEFMTU:
1573: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1574: #endif
1.26 thorpej 1575: case IPCTL_FORWSRCRT:
1.47 cjs 1576: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1577: if (securelevel > 0)
1.46 cjs 1578: return (sysctl_rdint(oldp, oldlenp, newp,
1579: ip_forwsrcrt));
1580: else
1581: return (sysctl_int(oldp, oldlenp, newp, newlen,
1582: &ip_forwsrcrt));
1.27 thorpej 1583: case IPCTL_DIRECTEDBCAST:
1584: return (sysctl_int(oldp, oldlenp, newp, newlen,
1585: &ip_directedbcast));
1.47 cjs 1586: case IPCTL_ALLOWSRCRT:
1587: return (sysctl_int(oldp, oldlenp, newp, newlen,
1588: &ip_allowsrcrt));
1.52 thorpej 1589: case IPCTL_SUBNETSARELOCAL:
1590: return (sysctl_int(oldp, oldlenp, newp, newlen,
1591: &subnetsarelocal));
1.53 kml 1592: case IPCTL_MTUDISC:
1.60 kml 1593: error = sysctl_int(oldp, oldlenp, newp, newlen,
1594: &ip_mtudisc);
1595: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1596: ip_mtudisc_timeout_q =
1597: rt_timer_queue_create(ip_mtudisc_timeout);
1598: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1599: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1600: ip_mtudisc_timeout_q = NULL;
1601: }
1602: return error;
1.54 lukem 1603: case IPCTL_ANONPORTMIN:
1604: old = anonportmin;
1605: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1606: if (anonportmin >= anonportmax || anonportmin > 65535
1607: #ifndef IPNOPRIVPORTS
1608: || anonportmin < IPPORT_RESERVED
1609: #endif
1610: ) {
1611: anonportmin = old;
1612: return (EINVAL);
1613: }
1614: return (error);
1615: case IPCTL_ANONPORTMAX:
1616: old = anonportmax;
1617: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1618: if (anonportmin >= anonportmax || anonportmax > 65535
1619: #ifndef IPNOPRIVPORTS
1620: || anonportmax < IPPORT_RESERVED
1621: #endif
1622: ) {
1623: anonportmax = old;
1624: return (EINVAL);
1625: }
1.60 kml 1626: return (error);
1627: case IPCTL_MTUDISCTIMEOUT:
1628: error = sysctl_int(oldp, oldlenp, newp, newlen,
1629: &ip_mtudisc_timeout);
1630: if (ip_mtudisc_timeout_q != NULL)
1631: rt_timer_queue_change(ip_mtudisc_timeout_q,
1632: ip_mtudisc_timeout);
1.54 lukem 1633: return (error);
1.65 matt 1634: #ifdef GATEWAY
1635: case IPCTL_MAXFLOWS:
1.67 thorpej 1636: {
1637: int s;
1638:
1.65 matt 1639: error = sysctl_int(oldp, oldlenp, newp, newlen,
1640: &ip_maxflows);
1.67 thorpej 1641: s = splsoftnet();
1.65 matt 1642: ipflow_reap(0);
1.67 thorpej 1643: splx(s);
1.65 matt 1644: return (error);
1.67 thorpej 1645: }
1.89 itojun 1646: #endif
1.90 itojun 1647: case IPCTL_HOSTZEROBROADCAST:
1648: return (sysctl_int(oldp, oldlenp, newp, newlen,
1649: &hostzeroisbroadcast));
1.89 itojun 1650: #if NGIF > 0
1651: case IPCTL_GIF_TTL:
1652: return(sysctl_int(oldp, oldlenp, newp, newlen,
1.90 itojun 1653: &ip_gif_ttl));
1.65 matt 1654: #endif
1.88 sommerfe 1655:
1.13 mycroft 1656: default:
1657: return (EOPNOTSUPP);
1658: }
1659: /* NOTREACHED */
1.1 cgd 1660: }
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