Annotation of src/sys/netinet/ip_input.c, Revision 1.82.2.2.4.1
1.82.2.2.4.1! itojun 1: /* $NetBSD: ip_input.c,v 1.82.2.2 1999/05/03 22:22:42 perry Exp $ */
1.76 thorpej 2:
3: /*-
4: * Copyright (c) 1998 The NetBSD Foundation, Inc.
5: * All rights reserved.
6: *
7: * This code is derived from software contributed to The NetBSD Foundation
8: * by Public Access Networks Corporation ("Panix"). It was developed under
9: * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
10: *
11: * Redistribution and use in source and binary forms, with or without
12: * modification, are permitted provided that the following conditions
13: * are met:
14: * 1. Redistributions of source code must retain the above copyright
15: * notice, this list of conditions and the following disclaimer.
16: * 2. Redistributions in binary form must reproduce the above copyright
17: * notice, this list of conditions and the following disclaimer in the
18: * documentation and/or other materials provided with the distribution.
19: * 3. All advertising materials mentioning features or use of this software
20: * must display the following acknowledgement:
21: * This product includes software developed by the NetBSD
22: * Foundation, Inc. and its contributors.
23: * 4. Neither the name of The NetBSD Foundation nor the names of its
24: * contributors may be used to endorse or promote products derived
25: * from this software without specific prior written permission.
26: *
27: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37: * POSSIBILITY OF SUCH DAMAGE.
38: */
1.14 cgd 39:
1.1 cgd 40: /*
1.82.2.2.4.1! itojun 41: * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
! 42: * All rights reserved.
! 43: *
! 44: * Redistribution and use in source and binary forms, with or without
! 45: * modification, are permitted provided that the following conditions
! 46: * are met:
! 47: * 1. Redistributions of source code must retain the above copyright
! 48: * notice, this list of conditions and the following disclaimer.
! 49: * 2. Redistributions in binary form must reproduce the above copyright
! 50: * notice, this list of conditions and the following disclaimer in the
! 51: * documentation and/or other materials provided with the distribution.
! 52: * 3. Neither the name of the project nor the names of its contributors
! 53: * may be used to endorse or promote products derived from this software
! 54: * without specific prior written permission.
! 55: *
! 56: * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
! 57: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 58: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 59: * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
! 60: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 61: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 62: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 63: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 64: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 65: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 66: * SUCH DAMAGE.
! 67: */
! 68:
! 69: /*
1.13 mycroft 70: * Copyright (c) 1982, 1986, 1988, 1993
71: * The Regents of the University of California. All rights reserved.
1.1 cgd 72: *
73: * Redistribution and use in source and binary forms, with or without
74: * modification, are permitted provided that the following conditions
75: * are met:
76: * 1. Redistributions of source code must retain the above copyright
77: * notice, this list of conditions and the following disclaimer.
78: * 2. Redistributions in binary form must reproduce the above copyright
79: * notice, this list of conditions and the following disclaimer in the
80: * documentation and/or other materials provided with the distribution.
81: * 3. All advertising materials mentioning features or use of this software
82: * must display the following acknowledgement:
83: * This product includes software developed by the University of
84: * California, Berkeley and its contributors.
85: * 4. Neither the name of the University nor the names of its contributors
86: * may be used to endorse or promote products derived from this software
87: * without specific prior written permission.
88: *
89: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
90: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
91: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
92: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
93: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
94: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
95: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
96: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
97: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
98: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
99: * SUCH DAMAGE.
100: *
1.14 cgd 101: * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
1.1 cgd 102: */
1.55 scottr 103:
1.62 matt 104: #include "opt_gateway.h"
1.69 mrg 105: #include "opt_pfil_hooks.h"
1.55 scottr 106: #include "opt_mrouting.h"
1.1 cgd 107:
1.5 mycroft 108: #include <sys/param.h>
109: #include <sys/systm.h>
110: #include <sys/malloc.h>
111: #include <sys/mbuf.h>
112: #include <sys/domain.h>
113: #include <sys/protosw.h>
114: #include <sys/socket.h>
1.44 thorpej 115: #include <sys/socketvar.h>
1.5 mycroft 116: #include <sys/errno.h>
117: #include <sys/time.h>
118: #include <sys/kernel.h>
1.28 christos 119: #include <sys/proc.h>
1.72 thorpej 120: #include <sys/pool.h>
1.28 christos 121:
122: #include <vm/vm.h>
123: #include <sys/sysctl.h>
1.1 cgd 124:
1.5 mycroft 125: #include <net/if.h>
1.44 thorpej 126: #include <net/if_dl.h>
1.5 mycroft 127: #include <net/route.h>
1.45 mrg 128: #include <net/pfil.h>
1.1 cgd 129:
1.5 mycroft 130: #include <netinet/in.h>
131: #include <netinet/in_systm.h>
132: #include <netinet/ip.h>
133: #include <netinet/in_pcb.h>
134: #include <netinet/in_var.h>
135: #include <netinet/ip_var.h>
136: #include <netinet/ip_icmp.h>
1.82.2.2.4.1! itojun 137: /* just for gif_ttl */
! 138: #include <netinet/in_gif.h>
! 139: #include "gif.h"
! 140:
! 141: #ifdef IPSEC
! 142: #include <netinet6/ipsec.h>
! 143: #include <netinet6/ah.h>
! 144: #include <netinet6/esp.h>
! 145: #include <netkey/key.h>
! 146: #include <netkey/key_debug.h>
! 147: #endif
1.44 thorpej 148:
1.1 cgd 149: #ifndef IPFORWARDING
150: #ifdef GATEWAY
151: #define IPFORWARDING 1 /* forward IP packets not for us */
152: #else /* GATEWAY */
153: #define IPFORWARDING 0 /* don't forward IP packets not for us */
154: #endif /* GATEWAY */
155: #endif /* IPFORWARDING */
156: #ifndef IPSENDREDIRECTS
157: #define IPSENDREDIRECTS 1
158: #endif
1.26 thorpej 159: #ifndef IPFORWSRCRT
1.47 cjs 160: #define IPFORWSRCRT 1 /* forward source-routed packets */
161: #endif
162: #ifndef IPALLOWSRCRT
1.48 mrg 163: #define IPALLOWSRCRT 1 /* allow source-routed packets */
1.26 thorpej 164: #endif
1.53 kml 165: #ifndef IPMTUDISC
166: #define IPMTUDISC 0
167: #endif
1.60 kml 168: #ifndef IPMTUDISCTIMEOUT
1.61 kml 169: #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
1.60 kml 170: #endif
1.53 kml 171:
1.27 thorpej 172: /*
173: * Note: DIRECTED_BROADCAST is handled this way so that previous
174: * configuration using this option will Just Work.
175: */
176: #ifndef IPDIRECTEDBCAST
177: #ifdef DIRECTED_BROADCAST
178: #define IPDIRECTEDBCAST 1
179: #else
180: #define IPDIRECTEDBCAST 0
181: #endif /* DIRECTED_BROADCAST */
182: #endif /* IPDIRECTEDBCAST */
1.1 cgd 183: int ipforwarding = IPFORWARDING;
184: int ipsendredirects = IPSENDREDIRECTS;
1.13 mycroft 185: int ip_defttl = IPDEFTTL;
1.26 thorpej 186: int ip_forwsrcrt = IPFORWSRCRT;
1.27 thorpej 187: int ip_directedbcast = IPDIRECTEDBCAST;
1.47 cjs 188: int ip_allowsrcrt = IPALLOWSRCRT;
1.53 kml 189: int ip_mtudisc = IPMTUDISC;
1.60 kml 190: u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1 cgd 191: #ifdef DIAGNOSTIC
192: int ipprintfs = 0;
193: #endif
194:
1.60 kml 195: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
196:
1.1 cgd 197: extern struct domain inetdomain;
198: extern struct protosw inetsw[];
199: u_char ip_protox[IPPROTO_MAX];
200: int ipqmaxlen = IFQ_MAXLEN;
1.22 mycroft 201: struct in_ifaddrhead in_ifaddr;
1.57 tls 202: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.13 mycroft 203: struct ifqueue ipintrq;
1.63 matt 204: struct ipstat ipstat;
205: u_int16_t ip_id;
206: int ip_defttl;
1.75 thorpej 207:
1.63 matt 208: struct ipqhead ipq;
1.75 thorpej 209: int ipq_locked;
210:
211: static __inline int ipq_lock_try __P((void));
212: static __inline void ipq_unlock __P((void));
213:
214: static __inline int
215: ipq_lock_try()
216: {
217: int s;
218:
219: s = splimp();
220: if (ipq_locked) {
221: splx(s);
222: return (0);
223: }
224: ipq_locked = 1;
225: splx(s);
226: return (1);
227: }
228:
229: static __inline void
230: ipq_unlock()
231: {
232: int s;
233:
234: s = splimp();
235: ipq_locked = 0;
236: splx(s);
237: }
238:
239: #ifdef DIAGNOSTIC
240: #define IPQ_LOCK() \
241: do { \
242: if (ipq_lock_try() == 0) { \
243: printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
244: panic("ipq_lock"); \
245: } \
246: } while (0)
247: #define IPQ_LOCK_CHECK() \
248: do { \
249: if (ipq_locked == 0) { \
250: printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
251: panic("ipq lock check"); \
252: } \
253: } while (0)
254: #else
255: #define IPQ_LOCK() (void) ipq_lock_try()
256: #define IPQ_LOCK_CHECK() /* nothing */
257: #endif
258:
259: #define IPQ_UNLOCK() ipq_unlock()
1.1 cgd 260:
1.72 thorpej 261: struct pool ipqent_pool;
262:
1.1 cgd 263: /*
264: * We need to save the IP options in case a protocol wants to respond
265: * to an incoming packet over the same route if the packet got here
266: * using IP source routing. This allows connection establishment and
267: * maintenance when the remote end is on a network that is not known
268: * to us.
269: */
270: int ip_nhops = 0;
271: static struct ip_srcrt {
272: struct in_addr dst; /* final destination */
273: char nop; /* one NOP to align */
274: char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
275: struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
276: } ip_srcrt;
277:
1.13 mycroft 278: static void save_rte __P((u_char *, struct in_addr));
1.35 mycroft 279:
1.1 cgd 280: /*
281: * IP initialization: fill in IP protocol switch table.
282: * All protocols not implemented in kernel go to raw IP protocol handler.
283: */
1.8 mycroft 284: void
1.1 cgd 285: ip_init()
286: {
287: register struct protosw *pr;
288: register int i;
289:
1.72 thorpej 290: pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
291: 0, NULL, NULL, M_IPQ);
292:
1.1 cgd 293: pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
294: if (pr == 0)
295: panic("ip_init");
296: for (i = 0; i < IPPROTO_MAX; i++)
297: ip_protox[i] = pr - inetsw;
298: for (pr = inetdomain.dom_protosw;
299: pr < inetdomain.dom_protoswNPROTOSW; pr++)
300: if (pr->pr_domain->dom_family == PF_INET &&
301: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
302: ip_protox[pr->pr_protocol] = pr - inetsw;
1.25 cgd 303: LIST_INIT(&ipq);
1.1 cgd 304: ip_id = time.tv_sec & 0xffff;
305: ipintrq.ifq_maxlen = ipqmaxlen;
1.22 mycroft 306: TAILQ_INIT(&in_ifaddr);
1.57 tls 307: in_ifaddrhashtbl =
308: hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash);
1.60 kml 309: if (ip_mtudisc != 0)
310: ip_mtudisc_timeout_q =
311: rt_timer_queue_create(ip_mtudisc_timeout);
1.73 thorpej 312: #ifdef GATEWAY
313: ipflow_init();
314: #endif
1.1 cgd 315: }
316:
317: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
318: struct route ipforward_rt;
319:
320: /*
1.82.2.2.4.1! itojun 321: * IP software interrupt routine
! 322: */
! 323: void
! 324: ipintr()
! 325: {
! 326: int s;
! 327: struct mbuf *m;
! 328:
! 329: while (1) {
! 330: s = splimp();
! 331: IF_DEQUEUE(&ipintrq, m);
! 332: splx(s);
! 333: if (m == 0)
! 334: return;
! 335: ip_input(m);
! 336: }
! 337: }
! 338:
! 339: /*
1.1 cgd 340: * Ip input routine. Checksum and byte swap header. If fragmented
341: * try to reassemble. Process options. Pass to next level.
342: */
1.8 mycroft 343: void
1.82.2.2.4.1! itojun 344: ip_input(struct mbuf *m)
1.1 cgd 345: {
1.33 mrg 346: register struct ip *ip = NULL;
1.1 cgd 347: register struct ipq *fp;
348: register struct in_ifaddr *ia;
1.57 tls 349: register struct ifaddr *ifa;
1.25 cgd 350: struct ipqent *ipqe;
1.82.2.2.4.1! itojun 351: int hlen = 0, mff, len;
1.36 mrg 352: #ifdef PFIL_HOOKS
1.33 mrg 353: struct packet_filter_hook *pfh;
354: struct mbuf *m0;
1.43 mrg 355: int rv;
1.36 mrg 356: #endif /* PFIL_HOOKS */
1.1 cgd 357:
358: #ifdef DIAGNOSTIC
359: if ((m->m_flags & M_PKTHDR) == 0)
360: panic("ipintr no HDR");
361: #endif
1.82.2.2.4.1! itojun 362: #ifdef IPSEC
! 363: /*
! 364: * should the inner packet be considered authentic?
! 365: * see comment in ah4_input().
! 366: */
! 367: if (m) {
! 368: m->m_flags &= ~M_AUTHIPHDR;
! 369: m->m_flags &= ~M_AUTHIPDGM;
! 370: }
! 371: #endif
1.1 cgd 372: /*
373: * If no IP addresses have been set yet but the interfaces
374: * are receiving, can't do anything with incoming packets yet.
375: */
1.22 mycroft 376: if (in_ifaddr.tqh_first == 0)
1.1 cgd 377: goto bad;
378: ipstat.ips_total++;
379: if (m->m_len < sizeof (struct ip) &&
380: (m = m_pullup(m, sizeof (struct ip))) == 0) {
381: ipstat.ips_toosmall++;
1.82.2.2.4.1! itojun 382: return;
1.1 cgd 383: }
384: ip = mtod(m, struct ip *);
1.13 mycroft 385: if (ip->ip_v != IPVERSION) {
386: ipstat.ips_badvers++;
387: goto bad;
388: }
1.1 cgd 389: hlen = ip->ip_hl << 2;
390: if (hlen < sizeof(struct ip)) { /* minimum header length */
391: ipstat.ips_badhlen++;
392: goto bad;
393: }
394: if (hlen > m->m_len) {
395: if ((m = m_pullup(m, hlen)) == 0) {
396: ipstat.ips_badhlen++;
1.82.2.2.4.1! itojun 397: return;
1.1 cgd 398: }
399: ip = mtod(m, struct ip *);
400: }
1.78 mycroft 401: if (in_cksum(m, hlen) != 0) {
1.1 cgd 402: ipstat.ips_badsum++;
403: goto bad;
404: }
405:
406: /*
407: * Convert fields to host representation.
408: */
409: NTOHS(ip->ip_len);
410: NTOHS(ip->ip_off);
1.35 mycroft 411: len = ip->ip_len;
1.81 proff 412:
413: /*
414: * Check for additional length bogosity
415: */
416: if (len < hlen)
417: {
418: ipstat.ips_badlen++;
419: goto bad;
420: }
1.1 cgd 421:
422: /*
423: * Check that the amount of data in the buffers
424: * is as at least much as the IP header would have us expect.
425: * Trim mbufs if longer than we expect.
426: * Drop packet if shorter than we expect.
427: */
1.35 mycroft 428: if (m->m_pkthdr.len < len) {
1.1 cgd 429: ipstat.ips_tooshort++;
430: goto bad;
431: }
1.35 mycroft 432: if (m->m_pkthdr.len > len) {
1.1 cgd 433: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 434: m->m_len = len;
435: m->m_pkthdr.len = len;
1.1 cgd 436: } else
1.35 mycroft 437: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 438: }
439:
1.64 thorpej 440: /*
441: * Assume that we can create a fast-forward IP flow entry
442: * based on this packet.
443: */
444: m->m_flags |= M_CANFASTFWD;
445:
1.36 mrg 446: #ifdef PFIL_HOOKS
1.33 mrg 447: /*
1.64 thorpej 448: * Run through list of hooks for input packets. If there are any
449: * filters which require that additional packets in the flow are
450: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
451: * Note that filters must _never_ set this flag, as another filter
452: * in the list may have previously cleared it.
1.33 mrg 453: */
454: m0 = m;
1.59 mrg 455: for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33 mrg 456: if (pfh->pfil_func) {
1.43 mrg 457: rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
458: if (rv)
1.82.2.2.4.1! itojun 459: return;
1.68 sommerfe 460: m = m0;
461: if (m == NULL)
1.82.2.2.4.1! itojun 462: return;
1.68 sommerfe 463: ip = mtod(m, struct ip *);
1.33 mrg 464: }
1.36 mrg 465: #endif /* PFIL_HOOKS */
1.33 mrg 466:
1.1 cgd 467: /*
468: * Process options and, if not destined for us,
469: * ship it on. ip_dooptions returns 1 when an
470: * error was detected (causing an icmp message
471: * to be sent and the original packet to be freed).
472: */
473: ip_nhops = 0; /* for source routed packets */
474: if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.82.2.2.4.1! itojun 475: return;
1.1 cgd 476:
477: /*
478: * Check our list of addresses, to see if the packet is for us.
479: */
1.57 tls 480: INADDR_TO_IA(ip->ip_dst, ia);
1.82.2.2 perry 481: if (ia != NULL)
482: goto ours;
1.57 tls 483: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
484: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
485: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
486: if (ifa->ifa_addr->sa_family != AF_INET) continue;
487: ia = ifatoia(ifa);
1.35 mycroft 488: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
489: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 490: /*
491: * Look for all-0's host part (old broadcast addr),
492: * either for subnet or net.
493: */
494: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 495: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 496: goto ours;
1.57 tls 497: /*
498: * An interface with IP address zero accepts
499: * all packets that arrive on that interface.
500: */
501: if (in_nullhost(ia->ia_addr.sin_addr))
502: goto ours;
1.1 cgd 503: }
504: }
1.18 mycroft 505: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 506: struct in_multi *inm;
507: #ifdef MROUTING
508: extern struct socket *ip_mrouter;
1.10 brezak 509:
510: if (m->m_flags & M_EXT) {
511: if ((m = m_pullup(m, hlen)) == 0) {
512: ipstat.ips_toosmall++;
1.82.2.2.4.1! itojun 513: return;
1.10 brezak 514: }
515: ip = mtod(m, struct ip *);
516: }
1.4 hpeyerl 517:
518: if (ip_mrouter) {
519: /*
520: * If we are acting as a multicast router, all
521: * incoming multicast packets are passed to the
522: * kernel-level multicast forwarding function.
523: * The packet is returned (relatively) intact; if
524: * ip_mforward() returns a non-zero value, the packet
525: * must be discarded, else it may be accepted below.
526: *
527: * (The IP ident field is put in the same byte order
528: * as expected when ip_mforward() is called from
529: * ip_output().)
530: */
1.13 mycroft 531: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
532: ipstat.ips_cantforward++;
1.4 hpeyerl 533: m_freem(m);
1.82.2.2.4.1! itojun 534: return;
1.4 hpeyerl 535: }
536:
537: /*
538: * The process-level routing demon needs to receive
539: * all multicast IGMP packets, whether or not this
540: * host belongs to their destination groups.
541: */
542: if (ip->ip_p == IPPROTO_IGMP)
543: goto ours;
1.13 mycroft 544: ipstat.ips_forward++;
1.4 hpeyerl 545: }
546: #endif
547: /*
548: * See if we belong to the destination multicast group on the
549: * arrival interface.
550: */
551: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
552: if (inm == NULL) {
1.13 mycroft 553: ipstat.ips_cantforward++;
1.4 hpeyerl 554: m_freem(m);
1.82.2.2.4.1! itojun 555: return;
1.4 hpeyerl 556: }
557: goto ours;
558: }
1.19 mycroft 559: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 560: in_nullhost(ip->ip_dst))
1.1 cgd 561: goto ours;
562:
563: /*
564: * Not for us; forward if possible and desirable.
565: */
566: if (ipforwarding == 0) {
567: ipstat.ips_cantforward++;
568: m_freem(m);
569: } else
570: ip_forward(m, 0);
1.82.2.2.4.1! itojun 571: return;
1.1 cgd 572:
573: ours:
574: /*
575: * If offset or IP_MF are set, must reassemble.
576: * Otherwise, nothing need be done.
577: * (We could look in the reassembly queue to see
578: * if the packet was previously fragmented,
579: * but it's not worth the time; just let them time out.)
580: */
1.37 perry 581: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 582: /*
583: * Look for queue of fragments
584: * of this datagram.
585: */
1.75 thorpej 586: IPQ_LOCK();
1.25 cgd 587: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 588: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 589: in_hosteq(ip->ip_src, fp->ipq_src) &&
590: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 591: ip->ip_p == fp->ipq_p)
592: goto found;
593: fp = 0;
594: found:
595:
596: /*
597: * Adjust ip_len to not reflect header,
1.25 cgd 598: * set ipqe_mff if more fragments are expected,
1.1 cgd 599: * convert offset of this to bytes.
600: */
601: ip->ip_len -= hlen;
1.25 cgd 602: mff = (ip->ip_off & IP_MF) != 0;
603: if (mff) {
1.16 cgd 604: /*
605: * Make sure that fragments have a data length
606: * that's a non-zero multiple of 8 bytes.
607: */
1.17 cgd 608: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 609: ipstat.ips_badfrags++;
1.75 thorpej 610: IPQ_UNLOCK();
1.16 cgd 611: goto bad;
612: }
613: }
1.1 cgd 614: ip->ip_off <<= 3;
615:
616: /*
617: * If datagram marked as having more fragments
618: * or if this is not the first fragment,
619: * attempt reassembly; if it succeeds, proceed.
620: */
1.25 cgd 621: if (mff || ip->ip_off) {
1.1 cgd 622: ipstat.ips_fragments++;
1.72 thorpej 623: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 624: if (ipqe == NULL) {
625: ipstat.ips_rcvmemdrop++;
1.75 thorpej 626: IPQ_UNLOCK();
1.25 cgd 627: goto bad;
628: }
629: ipqe->ipqe_mff = mff;
1.50 thorpej 630: ipqe->ipqe_m = m;
1.25 cgd 631: ipqe->ipqe_ip = ip;
1.50 thorpej 632: m = ip_reass(ipqe, fp);
1.75 thorpej 633: if (m == 0) {
634: IPQ_UNLOCK();
1.82.2.2.4.1! itojun 635: return;
1.75 thorpej 636: }
1.13 mycroft 637: ipstat.ips_reassembled++;
1.50 thorpej 638: ip = mtod(m, struct ip *);
1.74 thorpej 639: hlen = ip->ip_hl << 2;
1.79 mycroft 640: ip->ip_len += hlen;
1.1 cgd 641: } else
642: if (fp)
643: ip_freef(fp);
1.75 thorpej 644: IPQ_UNLOCK();
1.79 mycroft 645: }
1.1 cgd 646:
647: /*
648: * Switch out to protocol's input routine.
649: */
1.82 aidan 650: #if IFA_STATS
651: ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
652: #endif
1.1 cgd 653: ipstat.ips_delivered++;
1.82.2.2.4.1! itojun 654: {
! 655: int off = hlen, nh = ip->ip_p;
! 656:
! 657: (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
! 658: return;
! 659: }
1.1 cgd 660: bad:
661: m_freem(m);
662: }
663:
664: /*
665: * Take incoming datagram fragment and try to
666: * reassemble it into whole datagram. If a chain for
667: * reassembly of this datagram already exists, then it
668: * is given as fp; otherwise have to make a chain.
669: */
1.50 thorpej 670: struct mbuf *
1.25 cgd 671: ip_reass(ipqe, fp)
672: register struct ipqent *ipqe;
1.1 cgd 673: register struct ipq *fp;
674: {
1.50 thorpej 675: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 676: register struct ipqent *nq, *p, *q;
677: struct ip *ip;
1.1 cgd 678: struct mbuf *t;
1.25 cgd 679: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 680: int i, next;
681:
1.75 thorpej 682: IPQ_LOCK_CHECK();
683:
1.1 cgd 684: /*
685: * Presence of header sizes in mbufs
686: * would confuse code below.
687: */
688: m->m_data += hlen;
689: m->m_len -= hlen;
690:
691: /*
692: * If first fragment to arrive, create a reassembly queue.
693: */
694: if (fp == 0) {
1.50 thorpej 695: MALLOC(fp, struct ipq *, sizeof (struct ipq),
696: M_FTABLE, M_NOWAIT);
697: if (fp == NULL)
1.1 cgd 698: goto dropfrag;
1.25 cgd 699: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 700: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 701: fp->ipq_p = ipqe->ipqe_ip->ip_p;
702: fp->ipq_id = ipqe->ipqe_ip->ip_id;
703: LIST_INIT(&fp->ipq_fragq);
704: fp->ipq_src = ipqe->ipqe_ip->ip_src;
705: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
706: p = NULL;
1.1 cgd 707: goto insert;
708: }
709:
710: /*
711: * Find a segment which begins after this one does.
712: */
1.25 cgd 713: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
714: p = q, q = q->ipqe_q.le_next)
715: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 716: break;
717:
718: /*
719: * If there is a preceding segment, it may provide some of
720: * our data already. If so, drop the data from the incoming
721: * segment. If it provides all of our data, drop us.
722: */
1.25 cgd 723: if (p != NULL) {
724: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
725: ipqe->ipqe_ip->ip_off;
1.1 cgd 726: if (i > 0) {
1.25 cgd 727: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 728: goto dropfrag;
1.50 thorpej 729: m_adj(ipqe->ipqe_m, i);
1.25 cgd 730: ipqe->ipqe_ip->ip_off += i;
731: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 732: }
733: }
734:
735: /*
736: * While we overlap succeeding segments trim them or,
737: * if they are completely covered, dequeue them.
738: */
1.25 cgd 739: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
740: q->ipqe_ip->ip_off; q = nq) {
741: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
742: q->ipqe_ip->ip_off;
743: if (i < q->ipqe_ip->ip_len) {
744: q->ipqe_ip->ip_len -= i;
745: q->ipqe_ip->ip_off += i;
1.50 thorpej 746: m_adj(q->ipqe_m, i);
1.1 cgd 747: break;
748: }
1.25 cgd 749: nq = q->ipqe_q.le_next;
1.50 thorpej 750: m_freem(q->ipqe_m);
1.25 cgd 751: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 752: pool_put(&ipqent_pool, q);
1.1 cgd 753: }
754:
755: insert:
756: /*
757: * Stick new segment in its place;
758: * check for complete reassembly.
759: */
1.25 cgd 760: if (p == NULL) {
761: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
762: } else {
763: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
764: }
1.1 cgd 765: next = 0;
1.25 cgd 766: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
767: p = q, q = q->ipqe_q.le_next) {
768: if (q->ipqe_ip->ip_off != next)
1.1 cgd 769: return (0);
1.25 cgd 770: next += q->ipqe_ip->ip_len;
1.1 cgd 771: }
1.25 cgd 772: if (p->ipqe_mff)
1.1 cgd 773: return (0);
774:
775: /*
1.41 thorpej 776: * Reassembly is complete. Check for a bogus message size and
777: * concatenate fragments.
1.1 cgd 778: */
1.25 cgd 779: q = fp->ipq_fragq.lh_first;
780: ip = q->ipqe_ip;
1.41 thorpej 781: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
782: ipstat.ips_toolong++;
783: ip_freef(fp);
784: return (0);
785: }
1.50 thorpej 786: m = q->ipqe_m;
1.1 cgd 787: t = m->m_next;
788: m->m_next = 0;
789: m_cat(m, t);
1.25 cgd 790: nq = q->ipqe_q.le_next;
1.72 thorpej 791: pool_put(&ipqent_pool, q);
1.25 cgd 792: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 793: t = q->ipqe_m;
1.25 cgd 794: nq = q->ipqe_q.le_next;
1.72 thorpej 795: pool_put(&ipqent_pool, q);
1.1 cgd 796: m_cat(m, t);
797: }
798:
799: /*
800: * Create header for new ip packet by
801: * modifying header of first packet;
802: * dequeue and discard fragment reassembly header.
803: * Make header visible.
804: */
805: ip->ip_len = next;
1.82.2.2.4.1! itojun 806: ip->ip_ttl = 0; /* xxx */
! 807: ip->ip_sum = 0;
1.25 cgd 808: ip->ip_src = fp->ipq_src;
809: ip->ip_dst = fp->ipq_dst;
810: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 811: FREE(fp, M_FTABLE);
1.1 cgd 812: m->m_len += (ip->ip_hl << 2);
813: m->m_data -= (ip->ip_hl << 2);
814: /* some debugging cruft by sklower, below, will go away soon */
815: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
816: register int plen = 0;
1.50 thorpej 817: for (t = m; t; t = t->m_next)
818: plen += t->m_len;
819: m->m_pkthdr.len = plen;
1.1 cgd 820: }
1.50 thorpej 821: return (m);
1.1 cgd 822:
823: dropfrag:
824: ipstat.ips_fragdropped++;
825: m_freem(m);
1.72 thorpej 826: pool_put(&ipqent_pool, ipqe);
1.1 cgd 827: return (0);
828: }
829:
830: /*
831: * Free a fragment reassembly header and all
832: * associated datagrams.
833: */
1.8 mycroft 834: void
1.1 cgd 835: ip_freef(fp)
836: struct ipq *fp;
837: {
1.25 cgd 838: register struct ipqent *q, *p;
1.1 cgd 839:
1.75 thorpej 840: IPQ_LOCK_CHECK();
841:
1.25 cgd 842: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
843: p = q->ipqe_q.le_next;
1.50 thorpej 844: m_freem(q->ipqe_m);
1.25 cgd 845: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 846: pool_put(&ipqent_pool, q);
1.1 cgd 847: }
1.25 cgd 848: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 849: FREE(fp, M_FTABLE);
1.1 cgd 850: }
851:
852: /*
853: * IP timer processing;
854: * if a timer expires on a reassembly
855: * queue, discard it.
856: */
1.8 mycroft 857: void
1.1 cgd 858: ip_slowtimo()
859: {
1.25 cgd 860: register struct ipq *fp, *nfp;
1.24 mycroft 861: int s = splsoftnet();
1.1 cgd 862:
1.75 thorpej 863: IPQ_LOCK();
1.25 cgd 864: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
865: nfp = fp->ipq_q.le_next;
866: if (--fp->ipq_ttl == 0) {
1.1 cgd 867: ipstat.ips_fragtimeout++;
1.25 cgd 868: ip_freef(fp);
1.1 cgd 869: }
870: }
1.75 thorpej 871: IPQ_UNLOCK();
1.63 matt 872: #ifdef GATEWAY
873: ipflow_slowtimo();
874: #endif
1.1 cgd 875: splx(s);
876: }
877:
878: /*
879: * Drain off all datagram fragments.
880: */
1.8 mycroft 881: void
1.1 cgd 882: ip_drain()
883: {
884:
1.75 thorpej 885: /*
886: * We may be called from a device's interrupt context. If
887: * the ipq is already busy, just bail out now.
888: */
889: if (ipq_lock_try() == 0)
890: return;
891:
1.25 cgd 892: while (ipq.lh_first != NULL) {
1.1 cgd 893: ipstat.ips_fragdropped++;
1.25 cgd 894: ip_freef(ipq.lh_first);
1.1 cgd 895: }
1.75 thorpej 896:
897: IPQ_UNLOCK();
1.1 cgd 898: }
899:
900: /*
901: * Do option processing on a datagram,
902: * possibly discarding it if bad options are encountered,
903: * or forwarding it if source-routed.
904: * Returns 1 if packet has been forwarded/freed,
905: * 0 if the packet should be processed further.
906: */
1.8 mycroft 907: int
1.1 cgd 908: ip_dooptions(m)
909: struct mbuf *m;
910: {
911: register struct ip *ip = mtod(m, struct ip *);
912: register u_char *cp;
913: register struct ip_timestamp *ipt;
914: register struct in_ifaddr *ia;
915: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13 mycroft 916: struct in_addr *sin, dst;
1.1 cgd 917: n_time ntime;
918:
1.13 mycroft 919: dst = ip->ip_dst;
1.1 cgd 920: cp = (u_char *)(ip + 1);
921: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
922: for (; cnt > 0; cnt -= optlen, cp += optlen) {
923: opt = cp[IPOPT_OPTVAL];
924: if (opt == IPOPT_EOL)
925: break;
926: if (opt == IPOPT_NOP)
927: optlen = 1;
928: else {
929: optlen = cp[IPOPT_OLEN];
930: if (optlen <= 0 || optlen > cnt) {
931: code = &cp[IPOPT_OLEN] - (u_char *)ip;
932: goto bad;
933: }
934: }
935: switch (opt) {
936:
937: default:
938: break;
939:
940: /*
941: * Source routing with record.
942: * Find interface with current destination address.
943: * If none on this machine then drop if strictly routed,
944: * or do nothing if loosely routed.
945: * Record interface address and bring up next address
946: * component. If strictly routed make sure next
947: * address is on directly accessible net.
948: */
949: case IPOPT_LSRR:
950: case IPOPT_SSRR:
1.47 cjs 951: if (ip_allowsrcrt == 0) {
952: type = ICMP_UNREACH;
953: code = ICMP_UNREACH_NET_PROHIB;
954: goto bad;
955: }
1.1 cgd 956: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
957: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
958: goto bad;
959: }
960: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 961: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 962: if (ia == 0) {
963: if (opt == IPOPT_SSRR) {
964: type = ICMP_UNREACH;
965: code = ICMP_UNREACH_SRCFAIL;
966: goto bad;
967: }
968: /*
969: * Loose routing, and not at next destination
970: * yet; nothing to do except forward.
971: */
972: break;
973: }
974: off--; /* 0 origin */
975: if (off > optlen - sizeof(struct in_addr)) {
976: /*
977: * End of source route. Should be for us.
978: */
979: save_rte(cp, ip->ip_src);
980: break;
981: }
982: /*
983: * locate outgoing interface
984: */
985: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
986: sizeof(ipaddr.sin_addr));
987: if (opt == IPOPT_SSRR) {
988: #define INA struct in_ifaddr *
989: #define SA struct sockaddr *
1.29 mrg 990: ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1 cgd 991: } else
992: ia = ip_rtaddr(ipaddr.sin_addr);
993: if (ia == 0) {
994: type = ICMP_UNREACH;
995: code = ICMP_UNREACH_SRCFAIL;
996: goto bad;
997: }
998: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 999: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1000: (caddr_t)(cp + off), sizeof(struct in_addr));
1001: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 1002: /*
1003: * Let ip_intr's mcast routing check handle mcast pkts
1004: */
1.18 mycroft 1005: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 1006: break;
1007:
1008: case IPOPT_RR:
1009: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1010: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1011: goto bad;
1012: }
1013: /*
1014: * If no space remains, ignore.
1015: */
1016: off--; /* 0 origin */
1017: if (off > optlen - sizeof(struct in_addr))
1018: break;
1019: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
1020: sizeof(ipaddr.sin_addr));
1021: /*
1022: * locate outgoing interface; if we're the destination,
1023: * use the incoming interface (should be same).
1024: */
1025: if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1026: (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1027: type = ICMP_UNREACH;
1028: code = ICMP_UNREACH_HOST;
1029: goto bad;
1030: }
1.20 mycroft 1031: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1032: (caddr_t)(cp + off), sizeof(struct in_addr));
1033: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1034: break;
1035:
1036: case IPOPT_TS:
1037: code = cp - (u_char *)ip;
1038: ipt = (struct ip_timestamp *)cp;
1039: if (ipt->ipt_len < 5)
1040: goto bad;
1.15 cgd 1041: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 1042: if (++ipt->ipt_oflw == 0)
1043: goto bad;
1044: break;
1045: }
1046: sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
1047: switch (ipt->ipt_flg) {
1048:
1049: case IPOPT_TS_TSONLY:
1050: break;
1051:
1052: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1053: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1054: sizeof(struct in_addr) > ipt->ipt_len)
1055: goto bad;
1.13 mycroft 1056: ipaddr.sin_addr = dst;
1057: ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1058: m->m_pkthdr.rcvif);
1059: if (ia == 0)
1060: continue;
1.20 mycroft 1061: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1062: (caddr_t)sin, sizeof(struct in_addr));
1063: ipt->ipt_ptr += sizeof(struct in_addr);
1064: break;
1065:
1066: case IPOPT_TS_PRESPEC:
1.66 thorpej 1067: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1068: sizeof(struct in_addr) > ipt->ipt_len)
1069: goto bad;
1070: bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
1071: sizeof(struct in_addr));
1072: if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1073: continue;
1074: ipt->ipt_ptr += sizeof(struct in_addr);
1075: break;
1076:
1077: default:
1078: goto bad;
1079: }
1080: ntime = iptime();
1081: bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
1082: sizeof(n_time));
1083: ipt->ipt_ptr += sizeof(n_time);
1084: }
1085: }
1086: if (forward) {
1.26 thorpej 1087: if (ip_forwsrcrt == 0) {
1088: type = ICMP_UNREACH;
1089: code = ICMP_UNREACH_SRCFAIL;
1090: goto bad;
1091: }
1.1 cgd 1092: ip_forward(m, 1);
1093: return (1);
1.13 mycroft 1094: }
1095: return (0);
1.1 cgd 1096: bad:
1.13 mycroft 1097: icmp_error(m, type, code, 0, 0);
1098: ipstat.ips_badoptions++;
1.1 cgd 1099: return (1);
1100: }
1101:
1102: /*
1103: * Given address of next destination (final or next hop),
1104: * return internet address info of interface to be used to get there.
1105: */
1106: struct in_ifaddr *
1107: ip_rtaddr(dst)
1108: struct in_addr dst;
1109: {
1110: register struct sockaddr_in *sin;
1111:
1.19 mycroft 1112: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1113:
1.35 mycroft 1114: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1115: if (ipforward_rt.ro_rt) {
1116: RTFREE(ipforward_rt.ro_rt);
1117: ipforward_rt.ro_rt = 0;
1118: }
1119: sin->sin_family = AF_INET;
1120: sin->sin_len = sizeof(*sin);
1121: sin->sin_addr = dst;
1122:
1123: rtalloc(&ipforward_rt);
1124: }
1125: if (ipforward_rt.ro_rt == 0)
1126: return ((struct in_ifaddr *)0);
1.19 mycroft 1127: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1128: }
1129:
1130: /*
1131: * Save incoming source route for use in replies,
1132: * to be picked up later by ip_srcroute if the receiver is interested.
1133: */
1.13 mycroft 1134: void
1.1 cgd 1135: save_rte(option, dst)
1136: u_char *option;
1137: struct in_addr dst;
1138: {
1139: unsigned olen;
1140:
1141: olen = option[IPOPT_OLEN];
1142: #ifdef DIAGNOSTIC
1143: if (ipprintfs)
1.39 christos 1144: printf("save_rte: olen %d\n", olen);
1.82.2.2.4.1! itojun 1145: #endif /* 0 */
1.1 cgd 1146: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1147: return;
1148: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1149: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1150: ip_srcrt.dst = dst;
1151: }
1152:
1153: /*
1154: * Retrieve incoming source route for use in replies,
1155: * in the same form used by setsockopt.
1156: * The first hop is placed before the options, will be removed later.
1157: */
1158: struct mbuf *
1159: ip_srcroute()
1160: {
1161: register struct in_addr *p, *q;
1162: register struct mbuf *m;
1163:
1164: if (ip_nhops == 0)
1165: return ((struct mbuf *)0);
1166: m = m_get(M_DONTWAIT, MT_SOOPTS);
1167: if (m == 0)
1168: return ((struct mbuf *)0);
1169:
1.13 mycroft 1170: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1171:
1172: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1173: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1174: OPTSIZ;
1175: #ifdef DIAGNOSTIC
1176: if (ipprintfs)
1.39 christos 1177: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1178: #endif
1179:
1180: /*
1181: * First save first hop for return route
1182: */
1183: p = &ip_srcrt.route[ip_nhops - 1];
1184: *(mtod(m, struct in_addr *)) = *p--;
1185: #ifdef DIAGNOSTIC
1186: if (ipprintfs)
1.39 christos 1187: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1188: #endif
1189:
1190: /*
1191: * Copy option fields and padding (nop) to mbuf.
1192: */
1193: ip_srcrt.nop = IPOPT_NOP;
1194: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1195: bcopy((caddr_t)&ip_srcrt.nop,
1196: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1197: q = (struct in_addr *)(mtod(m, caddr_t) +
1198: sizeof(struct in_addr) + OPTSIZ);
1199: #undef OPTSIZ
1200: /*
1201: * Record return path as an IP source route,
1202: * reversing the path (pointers are now aligned).
1203: */
1204: while (p >= ip_srcrt.route) {
1205: #ifdef DIAGNOSTIC
1206: if (ipprintfs)
1.39 christos 1207: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1208: #endif
1209: *q++ = *p--;
1210: }
1211: /*
1212: * Last hop goes to final destination.
1213: */
1214: *q = ip_srcrt.dst;
1215: #ifdef DIAGNOSTIC
1216: if (ipprintfs)
1.39 christos 1217: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1218: #endif
1219: return (m);
1220: }
1221:
1222: /*
1223: * Strip out IP options, at higher
1224: * level protocol in the kernel.
1225: * Second argument is buffer to which options
1226: * will be moved, and return value is their length.
1227: * XXX should be deleted; last arg currently ignored.
1228: */
1.8 mycroft 1229: void
1.1 cgd 1230: ip_stripoptions(m, mopt)
1231: register struct mbuf *m;
1232: struct mbuf *mopt;
1233: {
1234: register int i;
1235: struct ip *ip = mtod(m, struct ip *);
1236: register caddr_t opts;
1237: int olen;
1238:
1.79 mycroft 1239: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1240: opts = (caddr_t)(ip + 1);
1241: i = m->m_len - (sizeof (struct ip) + olen);
1242: bcopy(opts + olen, opts, (unsigned)i);
1243: m->m_len -= olen;
1244: if (m->m_flags & M_PKTHDR)
1245: m->m_pkthdr.len -= olen;
1.79 mycroft 1246: ip->ip_len -= olen;
1247: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1248: }
1249:
1.23 mycroft 1250: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1251: 0, 0, 0, 0,
1252: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1253: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1254: EMSGSIZE, EHOSTUNREACH, 0, 0,
1255: 0, 0, 0, 0,
1256: ENOPROTOOPT
1257: };
1258:
1259: /*
1260: * Forward a packet. If some error occurs return the sender
1261: * an icmp packet. Note we can't always generate a meaningful
1262: * icmp message because icmp doesn't have a large enough repertoire
1263: * of codes and types.
1264: *
1265: * If not forwarding, just drop the packet. This could be confusing
1266: * if ipforwarding was zero but some routing protocol was advancing
1267: * us as a gateway to somewhere. However, we must let the routing
1268: * protocol deal with that.
1269: *
1270: * The srcrt parameter indicates whether the packet is being forwarded
1271: * via a source route.
1272: */
1.13 mycroft 1273: void
1.1 cgd 1274: ip_forward(m, srcrt)
1275: struct mbuf *m;
1276: int srcrt;
1277: {
1278: register struct ip *ip = mtod(m, struct ip *);
1279: register struct sockaddr_in *sin;
1280: register struct rtentry *rt;
1.28 christos 1281: int error, type = 0, code = 0;
1.1 cgd 1282: struct mbuf *mcopy;
1.13 mycroft 1283: n_long dest;
1284: struct ifnet *destifp;
1.82.2.2.4.1! itojun 1285: #ifdef IPSEC
! 1286: struct ifnet dummyifp;
! 1287: #endif
1.1 cgd 1288:
1.13 mycroft 1289: dest = 0;
1.1 cgd 1290: #ifdef DIAGNOSTIC
1291: if (ipprintfs)
1.70 thorpej 1292: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1293: ntohl(ip->ip_src.s_addr),
1294: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1295: #endif
1296: if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
1297: ipstat.ips_cantforward++;
1298: m_freem(m);
1299: return;
1300: }
1301: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1302: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1303: return;
1304: }
1305: ip->ip_ttl -= IPTTLDEC;
1306:
1.19 mycroft 1307: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1308: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1309: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1310: if (ipforward_rt.ro_rt) {
1311: RTFREE(ipforward_rt.ro_rt);
1312: ipforward_rt.ro_rt = 0;
1313: }
1314: sin->sin_family = AF_INET;
1.35 mycroft 1315: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1316: sin->sin_addr = ip->ip_dst;
1317:
1318: rtalloc(&ipforward_rt);
1319: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1320: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1321: return;
1322: }
1323: rt = ipforward_rt.ro_rt;
1324: }
1325:
1326: /*
1.34 mycroft 1327: * Save at most 68 bytes of the packet in case
1.1 cgd 1328: * we need to generate an ICMP message to the src.
1329: */
1.34 mycroft 1330: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1331:
1332: /*
1333: * If forwarding packet using same interface that it came in on,
1334: * perhaps should send a redirect to sender to shortcut a hop.
1335: * Only send redirect if source is sending directly to us,
1336: * and if packet was not source routed (or has any options).
1337: * Also, don't send redirect if forwarding using a default route
1338: * or a route modified by a redirect.
1339: */
1340: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1341: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1342: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1343: ipsendredirects && !srcrt) {
1.19 mycroft 1344: if (rt->rt_ifa &&
1345: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1346: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1347: if (rt->rt_flags & RTF_GATEWAY)
1348: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1349: else
1350: dest = ip->ip_dst.s_addr;
1351: /*
1352: * Router requirements says to only send host
1353: * redirects.
1354: */
1355: type = ICMP_REDIRECT;
1356: code = ICMP_REDIRECT_HOST;
1.1 cgd 1357: #ifdef DIAGNOSTIC
1.77 thorpej 1358: if (ipprintfs)
1359: printf("redirect (%d) to %x\n", code,
1360: (u_int32_t)dest);
1.1 cgd 1361: #endif
1362: }
1363: }
1364:
1.82.2.2.4.1! itojun 1365: #ifdef IPSEC
! 1366: m->m_pkthdr.rcvif = NULL;
! 1367: #endif /*IPSEC*/
1.27 thorpej 1368: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1369: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1370: if (error)
1371: ipstat.ips_cantforward++;
1372: else {
1373: ipstat.ips_forward++;
1374: if (type)
1375: ipstat.ips_redirectsent++;
1376: else {
1.63 matt 1377: if (mcopy) {
1378: #ifdef GATEWAY
1.64 thorpej 1379: if (mcopy->m_flags & M_CANFASTFWD)
1380: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1381: #endif
1.1 cgd 1382: m_freem(mcopy);
1.63 matt 1383: }
1.1 cgd 1384: return;
1385: }
1386: }
1387: if (mcopy == NULL)
1388: return;
1.13 mycroft 1389: destifp = NULL;
1390:
1.1 cgd 1391: switch (error) {
1392:
1393: case 0: /* forwarded, but need redirect */
1394: /* type, code set above */
1395: break;
1396:
1397: case ENETUNREACH: /* shouldn't happen, checked above */
1398: case EHOSTUNREACH:
1399: case ENETDOWN:
1400: case EHOSTDOWN:
1401: default:
1402: type = ICMP_UNREACH;
1403: code = ICMP_UNREACH_HOST;
1404: break;
1405:
1406: case EMSGSIZE:
1407: type = ICMP_UNREACH;
1408: code = ICMP_UNREACH_NEEDFRAG;
1.82.2.2.4.1! itojun 1409: #ifndef IPSEC
1.13 mycroft 1410: if (ipforward_rt.ro_rt)
1411: destifp = ipforward_rt.ro_rt->rt_ifp;
1.82.2.2.4.1! itojun 1412: #else
! 1413: /*
! 1414: * If the packet is routed over IPsec tunnel, tell the
! 1415: * originator the tunnel MTU.
! 1416: * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
! 1417: * XXX quickhack!!!
! 1418: */
! 1419: if (ipforward_rt.ro_rt) {
! 1420: struct secpolicy *sp;
! 1421: int ipsecerror;
! 1422: int ipsechdr;
! 1423: struct route *ro;
! 1424:
! 1425: sp = ipsec4_getpolicybyaddr(mcopy,
! 1426: IP_FORWARDING,
! 1427: &ipsecerror);
! 1428:
! 1429: if (sp == NULL)
! 1430: destifp = ipforward_rt.ro_rt->rt_ifp;
! 1431: else {
! 1432: /* count IPsec header size */
! 1433: ipsechdr = ipsec4_hdrsiz(mcopy, NULL);
! 1434:
! 1435: /*
! 1436: * find the correct route for outer IPv4
! 1437: * header, compute tunnel MTU.
! 1438: *
! 1439: * XXX BUG ALERT
! 1440: * The "dummyifp" code relies upon the fact
! 1441: * that icmp_error() touches only ifp->if_mtu.
! 1442: */
! 1443: /*XXX*/
! 1444: destifp = NULL;
! 1445: if (sp->req != NULL
! 1446: && sp->req->sa != NULL) {
! 1447: ro = &sp->req->sa->saidx->sa_route;
! 1448: if (ro->ro_rt && ro->ro_rt->rt_ifp) {
! 1449: dummyifp.if_mtu =
! 1450: ro->ro_rt->rt_ifp->if_mtu;
! 1451: dummyifp.if_mtu -= ipsechdr;
! 1452: destifp = &dummyifp;
! 1453: }
! 1454: }
! 1455:
! 1456: key_freesp(sp);
! 1457: }
! 1458: }
! 1459: #endif /*IPSEC*/
1.1 cgd 1460: ipstat.ips_cantfrag++;
1461: break;
1462:
1463: case ENOBUFS:
1464: type = ICMP_SOURCEQUENCH;
1465: code = 0;
1466: break;
1467: }
1.13 mycroft 1468: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1469: }
1470:
1471: void
1472: ip_savecontrol(inp, mp, ip, m)
1473: register struct inpcb *inp;
1474: register struct mbuf **mp;
1475: register struct ip *ip;
1476: register struct mbuf *m;
1477: {
1478:
1479: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1480: struct timeval tv;
1481:
1482: microtime(&tv);
1483: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1484: SCM_TIMESTAMP, SOL_SOCKET);
1485: if (*mp)
1486: mp = &(*mp)->m_next;
1487: }
1488: if (inp->inp_flags & INP_RECVDSTADDR) {
1489: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1490: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1491: if (*mp)
1492: mp = &(*mp)->m_next;
1493: }
1494: #ifdef notyet
1495: /*
1496: * XXX
1497: * Moving these out of udp_input() made them even more broken
1498: * than they already were.
1499: * - fenner@parc.xerox.com
1500: */
1501: /* options were tossed already */
1502: if (inp->inp_flags & INP_RECVOPTS) {
1503: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1504: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1505: if (*mp)
1506: mp = &(*mp)->m_next;
1507: }
1508: /* ip_srcroute doesn't do what we want here, need to fix */
1509: if (inp->inp_flags & INP_RECVRETOPTS) {
1510: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1511: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1512: if (*mp)
1513: mp = &(*mp)->m_next;
1514: }
1515: #endif
1516: if (inp->inp_flags & INP_RECVIF) {
1517: struct sockaddr_dl sdl;
1518:
1519: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1520: sdl.sdl_family = AF_LINK;
1521: sdl.sdl_index = m->m_pkthdr.rcvif ?
1522: m->m_pkthdr.rcvif->if_index : 0;
1523: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1524: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1525: IP_RECVIF, IPPROTO_IP);
1526: if (*mp)
1527: mp = &(*mp)->m_next;
1528: }
1.13 mycroft 1529: }
1530:
1531: int
1532: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1533: int *name;
1534: u_int namelen;
1535: void *oldp;
1536: size_t *oldlenp;
1537: void *newp;
1538: size_t newlen;
1539: {
1.52 thorpej 1540: extern int subnetsarelocal;
1541:
1.54 lukem 1542: int error, old;
1543:
1.13 mycroft 1544: /* All sysctl names at this level are terminal. */
1545: if (namelen != 1)
1546: return (ENOTDIR);
1547:
1548: switch (name[0]) {
1549: case IPCTL_FORWARDING:
1550: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1551: case IPCTL_SENDREDIRECTS:
1552: return (sysctl_int(oldp, oldlenp, newp, newlen,
1553: &ipsendredirects));
1554: case IPCTL_DEFTTL:
1555: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1556: #ifdef notyet
1557: case IPCTL_DEFMTU:
1558: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1559: #endif
1.26 thorpej 1560: case IPCTL_FORWSRCRT:
1.47 cjs 1561: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1562: if (securelevel > 0)
1.46 cjs 1563: return (sysctl_rdint(oldp, oldlenp, newp,
1564: ip_forwsrcrt));
1565: else
1566: return (sysctl_int(oldp, oldlenp, newp, newlen,
1567: &ip_forwsrcrt));
1.27 thorpej 1568: case IPCTL_DIRECTEDBCAST:
1569: return (sysctl_int(oldp, oldlenp, newp, newlen,
1570: &ip_directedbcast));
1.47 cjs 1571: case IPCTL_ALLOWSRCRT:
1572: return (sysctl_int(oldp, oldlenp, newp, newlen,
1573: &ip_allowsrcrt));
1.52 thorpej 1574: case IPCTL_SUBNETSARELOCAL:
1575: return (sysctl_int(oldp, oldlenp, newp, newlen,
1576: &subnetsarelocal));
1.53 kml 1577: case IPCTL_MTUDISC:
1.60 kml 1578: error = sysctl_int(oldp, oldlenp, newp, newlen,
1579: &ip_mtudisc);
1580: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1581: ip_mtudisc_timeout_q =
1582: rt_timer_queue_create(ip_mtudisc_timeout);
1583: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1584: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1585: ip_mtudisc_timeout_q = NULL;
1586: }
1587: return error;
1.54 lukem 1588: case IPCTL_ANONPORTMIN:
1589: old = anonportmin;
1590: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1591: if (anonportmin >= anonportmax || anonportmin > 65535
1592: #ifndef IPNOPRIVPORTS
1593: || anonportmin < IPPORT_RESERVED
1594: #endif
1595: ) {
1596: anonportmin = old;
1597: return (EINVAL);
1598: }
1599: return (error);
1600: case IPCTL_ANONPORTMAX:
1601: old = anonportmax;
1602: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1603: if (anonportmin >= anonportmax || anonportmax > 65535
1604: #ifndef IPNOPRIVPORTS
1605: || anonportmax < IPPORT_RESERVED
1606: #endif
1607: ) {
1608: anonportmax = old;
1609: return (EINVAL);
1610: }
1.60 kml 1611: return (error);
1612: case IPCTL_MTUDISCTIMEOUT:
1613: error = sysctl_int(oldp, oldlenp, newp, newlen,
1614: &ip_mtudisc_timeout);
1615: if (ip_mtudisc_timeout_q != NULL)
1616: rt_timer_queue_change(ip_mtudisc_timeout_q,
1617: ip_mtudisc_timeout);
1.54 lukem 1618: return (error);
1.65 matt 1619: #ifdef GATEWAY
1620: case IPCTL_MAXFLOWS:
1.67 thorpej 1621: {
1622: int s;
1623:
1.65 matt 1624: error = sysctl_int(oldp, oldlenp, newp, newlen,
1625: &ip_maxflows);
1.67 thorpej 1626: s = splsoftnet();
1.65 matt 1627: ipflow_reap(0);
1.67 thorpej 1628: splx(s);
1.65 matt 1629: return (error);
1.67 thorpej 1630: }
1.82.2.2.4.1! itojun 1631: #endif
! 1632: #if NGIF > 0
! 1633: case IPCTL_GIF_TTL:
! 1634: return(sysctl_int(oldp, oldlenp, newp, newlen,
! 1635: &gif_ttl));
1.65 matt 1636: #endif
1.13 mycroft 1637: default:
1638: return (EOPNOTSUPP);
1639: }
1640: /* NOTREACHED */
1.1 cgd 1641: }
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