Annotation of src/sys/netinet/ip_input.c, Revision 1.93
1.93 ! sommerfe 1: /* $NetBSD: ip_input.c,v 1.92 1999/07/23 15:21:17 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:
1.64 thorpej 446: /*
447: * Assume that we can create a fast-forward IP flow entry
448: * based on this packet.
449: */
450: m->m_flags |= M_CANFASTFWD;
451:
1.36 mrg 452: #ifdef PFIL_HOOKS
1.33 mrg 453: /*
1.64 thorpej 454: * Run through list of hooks for input packets. If there are any
455: * filters which require that additional packets in the flow are
456: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
457: * Note that filters must _never_ set this flag, as another filter
458: * in the list may have previously cleared it.
1.33 mrg 459: */
460: m0 = m;
1.59 mrg 461: for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33 mrg 462: if (pfh->pfil_func) {
1.43 mrg 463: rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
464: if (rv)
1.89 itojun 465: return;
1.68 sommerfe 466: m = m0;
467: if (m == NULL)
1.89 itojun 468: return;
1.68 sommerfe 469: ip = mtod(m, struct ip *);
1.33 mrg 470: }
1.36 mrg 471: #endif /* PFIL_HOOKS */
1.33 mrg 472:
1.1 cgd 473: /*
474: * Process options and, if not destined for us,
475: * ship it on. ip_dooptions returns 1 when an
476: * error was detected (causing an icmp message
477: * to be sent and the original packet to be freed).
478: */
479: ip_nhops = 0; /* for source routed packets */
480: if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.89 itojun 481: return;
1.1 cgd 482:
483: /*
484: * Check our list of addresses, to see if the packet is for us.
485: */
1.57 tls 486: INADDR_TO_IA(ip->ip_dst, ia);
1.86 thorpej 487: if (ia != NULL)
488: goto ours;
1.57 tls 489: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
490: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
491: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
492: if (ifa->ifa_addr->sa_family != AF_INET) continue;
493: ia = ifatoia(ifa);
1.35 mycroft 494: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
495: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 496: /*
497: * Look for all-0's host part (old broadcast addr),
498: * either for subnet or net.
499: */
500: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 501: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 502: goto ours;
1.57 tls 503: /*
504: * An interface with IP address zero accepts
505: * all packets that arrive on that interface.
506: */
507: if (in_nullhost(ia->ia_addr.sin_addr))
508: goto ours;
1.1 cgd 509: }
510: }
1.18 mycroft 511: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 512: struct in_multi *inm;
513: #ifdef MROUTING
514: extern struct socket *ip_mrouter;
1.10 brezak 515:
516: if (m->m_flags & M_EXT) {
517: if ((m = m_pullup(m, hlen)) == 0) {
518: ipstat.ips_toosmall++;
1.89 itojun 519: return;
1.10 brezak 520: }
521: ip = mtod(m, struct ip *);
522: }
1.4 hpeyerl 523:
524: if (ip_mrouter) {
525: /*
526: * If we are acting as a multicast router, all
527: * incoming multicast packets are passed to the
528: * kernel-level multicast forwarding function.
529: * The packet is returned (relatively) intact; if
530: * ip_mforward() returns a non-zero value, the packet
531: * must be discarded, else it may be accepted below.
532: *
533: * (The IP ident field is put in the same byte order
534: * as expected when ip_mforward() is called from
535: * ip_output().)
536: */
1.13 mycroft 537: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
538: ipstat.ips_cantforward++;
1.4 hpeyerl 539: m_freem(m);
1.89 itojun 540: return;
1.4 hpeyerl 541: }
542:
543: /*
544: * The process-level routing demon needs to receive
545: * all multicast IGMP packets, whether or not this
546: * host belongs to their destination groups.
547: */
548: if (ip->ip_p == IPPROTO_IGMP)
549: goto ours;
1.13 mycroft 550: ipstat.ips_forward++;
1.4 hpeyerl 551: }
552: #endif
553: /*
554: * See if we belong to the destination multicast group on the
555: * arrival interface.
556: */
557: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
558: if (inm == NULL) {
1.13 mycroft 559: ipstat.ips_cantforward++;
1.4 hpeyerl 560: m_freem(m);
1.89 itojun 561: return;
1.4 hpeyerl 562: }
563: goto ours;
564: }
1.19 mycroft 565: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 566: in_nullhost(ip->ip_dst))
1.1 cgd 567: goto ours;
568:
569: /*
570: * Not for us; forward if possible and desirable.
571: */
572: if (ipforwarding == 0) {
573: ipstat.ips_cantforward++;
574: m_freem(m);
575: } else
576: ip_forward(m, 0);
1.89 itojun 577: return;
1.1 cgd 578:
579: ours:
580: /*
581: * If offset or IP_MF are set, must reassemble.
582: * Otherwise, nothing need be done.
583: * (We could look in the reassembly queue to see
584: * if the packet was previously fragmented,
585: * but it's not worth the time; just let them time out.)
586: */
1.37 perry 587: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 588: /*
589: * Look for queue of fragments
590: * of this datagram.
591: */
1.75 thorpej 592: IPQ_LOCK();
1.25 cgd 593: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 594: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 595: in_hosteq(ip->ip_src, fp->ipq_src) &&
596: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 597: ip->ip_p == fp->ipq_p)
598: goto found;
599: fp = 0;
600: found:
601:
602: /*
603: * Adjust ip_len to not reflect header,
1.25 cgd 604: * set ipqe_mff if more fragments are expected,
1.1 cgd 605: * convert offset of this to bytes.
606: */
607: ip->ip_len -= hlen;
1.25 cgd 608: mff = (ip->ip_off & IP_MF) != 0;
609: if (mff) {
1.16 cgd 610: /*
611: * Make sure that fragments have a data length
612: * that's a non-zero multiple of 8 bytes.
613: */
1.17 cgd 614: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 615: ipstat.ips_badfrags++;
1.75 thorpej 616: IPQ_UNLOCK();
1.16 cgd 617: goto bad;
618: }
619: }
1.1 cgd 620: ip->ip_off <<= 3;
621:
622: /*
623: * If datagram marked as having more fragments
624: * or if this is not the first fragment,
625: * attempt reassembly; if it succeeds, proceed.
626: */
1.25 cgd 627: if (mff || ip->ip_off) {
1.1 cgd 628: ipstat.ips_fragments++;
1.72 thorpej 629: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 630: if (ipqe == NULL) {
631: ipstat.ips_rcvmemdrop++;
1.75 thorpej 632: IPQ_UNLOCK();
1.25 cgd 633: goto bad;
634: }
635: ipqe->ipqe_mff = mff;
1.50 thorpej 636: ipqe->ipqe_m = m;
1.25 cgd 637: ipqe->ipqe_ip = ip;
1.50 thorpej 638: m = ip_reass(ipqe, fp);
1.75 thorpej 639: if (m == 0) {
640: IPQ_UNLOCK();
1.89 itojun 641: return;
1.75 thorpej 642: }
1.13 mycroft 643: ipstat.ips_reassembled++;
1.50 thorpej 644: ip = mtod(m, struct ip *);
1.74 thorpej 645: hlen = ip->ip_hl << 2;
1.79 mycroft 646: ip->ip_len += hlen;
1.1 cgd 647: } else
648: if (fp)
649: ip_freef(fp);
1.75 thorpej 650: IPQ_UNLOCK();
1.79 mycroft 651: }
1.1 cgd 652:
653: /*
654: * Switch out to protocol's input routine.
655: */
1.82 aidan 656: #if IFA_STATS
657: ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
658: #endif
1.1 cgd 659: ipstat.ips_delivered++;
1.89 itojun 660: {
661: int off = hlen, nh = ip->ip_p;
662:
663: (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
664: return;
665: }
1.1 cgd 666: bad:
667: m_freem(m);
668: }
669:
670: /*
671: * Take incoming datagram fragment and try to
672: * reassemble it into whole datagram. If a chain for
673: * reassembly of this datagram already exists, then it
674: * is given as fp; otherwise have to make a chain.
675: */
1.50 thorpej 676: struct mbuf *
1.25 cgd 677: ip_reass(ipqe, fp)
678: register struct ipqent *ipqe;
1.1 cgd 679: register struct ipq *fp;
680: {
1.50 thorpej 681: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 682: register struct ipqent *nq, *p, *q;
683: struct ip *ip;
1.1 cgd 684: struct mbuf *t;
1.25 cgd 685: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 686: int i, next;
687:
1.75 thorpej 688: IPQ_LOCK_CHECK();
689:
1.1 cgd 690: /*
691: * Presence of header sizes in mbufs
692: * would confuse code below.
693: */
694: m->m_data += hlen;
695: m->m_len -= hlen;
696:
697: /*
698: * If first fragment to arrive, create a reassembly queue.
699: */
700: if (fp == 0) {
1.50 thorpej 701: MALLOC(fp, struct ipq *, sizeof (struct ipq),
702: M_FTABLE, M_NOWAIT);
703: if (fp == NULL)
1.1 cgd 704: goto dropfrag;
1.25 cgd 705: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 706: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 707: fp->ipq_p = ipqe->ipqe_ip->ip_p;
708: fp->ipq_id = ipqe->ipqe_ip->ip_id;
709: LIST_INIT(&fp->ipq_fragq);
710: fp->ipq_src = ipqe->ipqe_ip->ip_src;
711: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
712: p = NULL;
1.1 cgd 713: goto insert;
714: }
715:
716: /*
717: * Find a segment which begins after this one does.
718: */
1.25 cgd 719: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
720: p = q, q = q->ipqe_q.le_next)
721: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 722: break;
723:
724: /*
725: * If there is a preceding segment, it may provide some of
726: * our data already. If so, drop the data from the incoming
727: * segment. If it provides all of our data, drop us.
728: */
1.25 cgd 729: if (p != NULL) {
730: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
731: ipqe->ipqe_ip->ip_off;
1.1 cgd 732: if (i > 0) {
1.25 cgd 733: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 734: goto dropfrag;
1.50 thorpej 735: m_adj(ipqe->ipqe_m, i);
1.25 cgd 736: ipqe->ipqe_ip->ip_off += i;
737: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 738: }
739: }
740:
741: /*
742: * While we overlap succeeding segments trim them or,
743: * if they are completely covered, dequeue them.
744: */
1.25 cgd 745: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
746: q->ipqe_ip->ip_off; q = nq) {
747: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
748: q->ipqe_ip->ip_off;
749: if (i < q->ipqe_ip->ip_len) {
750: q->ipqe_ip->ip_len -= i;
751: q->ipqe_ip->ip_off += i;
1.50 thorpej 752: m_adj(q->ipqe_m, i);
1.1 cgd 753: break;
754: }
1.25 cgd 755: nq = q->ipqe_q.le_next;
1.50 thorpej 756: m_freem(q->ipqe_m);
1.25 cgd 757: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 758: pool_put(&ipqent_pool, q);
1.1 cgd 759: }
760:
761: insert:
762: /*
763: * Stick new segment in its place;
764: * check for complete reassembly.
765: */
1.25 cgd 766: if (p == NULL) {
767: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
768: } else {
769: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
770: }
1.1 cgd 771: next = 0;
1.25 cgd 772: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
773: p = q, q = q->ipqe_q.le_next) {
774: if (q->ipqe_ip->ip_off != next)
1.1 cgd 775: return (0);
1.25 cgd 776: next += q->ipqe_ip->ip_len;
1.1 cgd 777: }
1.25 cgd 778: if (p->ipqe_mff)
1.1 cgd 779: return (0);
780:
781: /*
1.41 thorpej 782: * Reassembly is complete. Check for a bogus message size and
783: * concatenate fragments.
1.1 cgd 784: */
1.25 cgd 785: q = fp->ipq_fragq.lh_first;
786: ip = q->ipqe_ip;
1.41 thorpej 787: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
788: ipstat.ips_toolong++;
789: ip_freef(fp);
790: return (0);
791: }
1.50 thorpej 792: m = q->ipqe_m;
1.1 cgd 793: t = m->m_next;
794: m->m_next = 0;
795: m_cat(m, t);
1.25 cgd 796: nq = q->ipqe_q.le_next;
1.72 thorpej 797: pool_put(&ipqent_pool, q);
1.25 cgd 798: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 799: t = q->ipqe_m;
1.25 cgd 800: nq = q->ipqe_q.le_next;
1.72 thorpej 801: pool_put(&ipqent_pool, q);
1.1 cgd 802: m_cat(m, t);
803: }
804:
805: /*
806: * Create header for new ip packet by
807: * modifying header of first packet;
808: * dequeue and discard fragment reassembly header.
809: * Make header visible.
810: */
811: ip->ip_len = next;
1.89 itojun 812: ip->ip_ttl = 0; /* xxx */
813: ip->ip_sum = 0;
1.25 cgd 814: ip->ip_src = fp->ipq_src;
815: ip->ip_dst = fp->ipq_dst;
816: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 817: FREE(fp, M_FTABLE);
1.1 cgd 818: m->m_len += (ip->ip_hl << 2);
819: m->m_data -= (ip->ip_hl << 2);
820: /* some debugging cruft by sklower, below, will go away soon */
821: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
822: register int plen = 0;
1.50 thorpej 823: for (t = m; t; t = t->m_next)
824: plen += t->m_len;
825: m->m_pkthdr.len = plen;
1.1 cgd 826: }
1.50 thorpej 827: return (m);
1.1 cgd 828:
829: dropfrag:
830: ipstat.ips_fragdropped++;
831: m_freem(m);
1.72 thorpej 832: pool_put(&ipqent_pool, ipqe);
1.1 cgd 833: return (0);
834: }
835:
836: /*
837: * Free a fragment reassembly header and all
838: * associated datagrams.
839: */
1.8 mycroft 840: void
1.1 cgd 841: ip_freef(fp)
842: struct ipq *fp;
843: {
1.25 cgd 844: register struct ipqent *q, *p;
1.1 cgd 845:
1.75 thorpej 846: IPQ_LOCK_CHECK();
847:
1.25 cgd 848: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
849: p = q->ipqe_q.le_next;
1.50 thorpej 850: m_freem(q->ipqe_m);
1.25 cgd 851: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 852: pool_put(&ipqent_pool, q);
1.1 cgd 853: }
1.25 cgd 854: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 855: FREE(fp, M_FTABLE);
1.1 cgd 856: }
857:
858: /*
859: * IP timer processing;
860: * if a timer expires on a reassembly
861: * queue, discard it.
862: */
1.8 mycroft 863: void
1.1 cgd 864: ip_slowtimo()
865: {
1.25 cgd 866: register struct ipq *fp, *nfp;
1.24 mycroft 867: int s = splsoftnet();
1.1 cgd 868:
1.75 thorpej 869: IPQ_LOCK();
1.25 cgd 870: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
871: nfp = fp->ipq_q.le_next;
872: if (--fp->ipq_ttl == 0) {
1.1 cgd 873: ipstat.ips_fragtimeout++;
1.25 cgd 874: ip_freef(fp);
1.1 cgd 875: }
876: }
1.75 thorpej 877: IPQ_UNLOCK();
1.63 matt 878: #ifdef GATEWAY
879: ipflow_slowtimo();
880: #endif
1.1 cgd 881: splx(s);
882: }
883:
884: /*
885: * Drain off all datagram fragments.
886: */
1.8 mycroft 887: void
1.1 cgd 888: ip_drain()
889: {
890:
1.75 thorpej 891: /*
892: * We may be called from a device's interrupt context. If
893: * the ipq is already busy, just bail out now.
894: */
895: if (ipq_lock_try() == 0)
896: return;
897:
1.25 cgd 898: while (ipq.lh_first != NULL) {
1.1 cgd 899: ipstat.ips_fragdropped++;
1.25 cgd 900: ip_freef(ipq.lh_first);
1.1 cgd 901: }
1.75 thorpej 902:
903: IPQ_UNLOCK();
1.1 cgd 904: }
905:
906: /*
907: * Do option processing on a datagram,
908: * possibly discarding it if bad options are encountered,
909: * or forwarding it if source-routed.
910: * Returns 1 if packet has been forwarded/freed,
911: * 0 if the packet should be processed further.
912: */
1.8 mycroft 913: int
1.1 cgd 914: ip_dooptions(m)
915: struct mbuf *m;
916: {
917: register struct ip *ip = mtod(m, struct ip *);
918: register u_char *cp;
919: register struct ip_timestamp *ipt;
920: register struct in_ifaddr *ia;
921: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13 mycroft 922: struct in_addr *sin, dst;
1.1 cgd 923: n_time ntime;
924:
1.13 mycroft 925: dst = ip->ip_dst;
1.1 cgd 926: cp = (u_char *)(ip + 1);
927: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
928: for (; cnt > 0; cnt -= optlen, cp += optlen) {
929: opt = cp[IPOPT_OPTVAL];
930: if (opt == IPOPT_EOL)
931: break;
932: if (opt == IPOPT_NOP)
933: optlen = 1;
934: else {
935: optlen = cp[IPOPT_OLEN];
936: if (optlen <= 0 || optlen > cnt) {
937: code = &cp[IPOPT_OLEN] - (u_char *)ip;
938: goto bad;
939: }
940: }
941: switch (opt) {
942:
943: default:
944: break;
945:
946: /*
947: * Source routing with record.
948: * Find interface with current destination address.
949: * If none on this machine then drop if strictly routed,
950: * or do nothing if loosely routed.
951: * Record interface address and bring up next address
952: * component. If strictly routed make sure next
953: * address is on directly accessible net.
954: */
955: case IPOPT_LSRR:
956: case IPOPT_SSRR:
1.47 cjs 957: if (ip_allowsrcrt == 0) {
958: type = ICMP_UNREACH;
959: code = ICMP_UNREACH_NET_PROHIB;
960: goto bad;
961: }
1.1 cgd 962: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
963: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
964: goto bad;
965: }
966: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 967: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 968: if (ia == 0) {
969: if (opt == IPOPT_SSRR) {
970: type = ICMP_UNREACH;
971: code = ICMP_UNREACH_SRCFAIL;
972: goto bad;
973: }
974: /*
975: * Loose routing, and not at next destination
976: * yet; nothing to do except forward.
977: */
978: break;
979: }
980: off--; /* 0 origin */
981: if (off > optlen - sizeof(struct in_addr)) {
982: /*
983: * End of source route. Should be for us.
984: */
985: save_rte(cp, ip->ip_src);
986: break;
987: }
988: /*
989: * locate outgoing interface
990: */
991: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
992: sizeof(ipaddr.sin_addr));
993: if (opt == IPOPT_SSRR) {
994: #define INA struct in_ifaddr *
995: #define SA struct sockaddr *
1.29 mrg 996: ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1 cgd 997: } else
998: ia = ip_rtaddr(ipaddr.sin_addr);
999: if (ia == 0) {
1000: type = ICMP_UNREACH;
1001: code = ICMP_UNREACH_SRCFAIL;
1002: goto bad;
1003: }
1004: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 1005: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1006: (caddr_t)(cp + off), sizeof(struct in_addr));
1007: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 1008: /*
1009: * Let ip_intr's mcast routing check handle mcast pkts
1010: */
1.18 mycroft 1011: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 1012: break;
1013:
1014: case IPOPT_RR:
1015: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1016: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1017: goto bad;
1018: }
1019: /*
1020: * If no space remains, ignore.
1021: */
1022: off--; /* 0 origin */
1023: if (off > optlen - sizeof(struct in_addr))
1024: break;
1025: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
1026: sizeof(ipaddr.sin_addr));
1027: /*
1028: * locate outgoing interface; if we're the destination,
1029: * use the incoming interface (should be same).
1030: */
1031: if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1032: (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1033: type = ICMP_UNREACH;
1034: code = ICMP_UNREACH_HOST;
1035: goto bad;
1036: }
1.20 mycroft 1037: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1038: (caddr_t)(cp + off), sizeof(struct in_addr));
1039: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1040: break;
1041:
1042: case IPOPT_TS:
1043: code = cp - (u_char *)ip;
1044: ipt = (struct ip_timestamp *)cp;
1045: if (ipt->ipt_len < 5)
1046: goto bad;
1.15 cgd 1047: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 1048: if (++ipt->ipt_oflw == 0)
1049: goto bad;
1050: break;
1051: }
1052: sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
1053: switch (ipt->ipt_flg) {
1054:
1055: case IPOPT_TS_TSONLY:
1056: break;
1057:
1058: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1059: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1060: sizeof(struct in_addr) > ipt->ipt_len)
1061: goto bad;
1.13 mycroft 1062: ipaddr.sin_addr = dst;
1063: ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1064: m->m_pkthdr.rcvif);
1065: if (ia == 0)
1066: continue;
1.20 mycroft 1067: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1068: (caddr_t)sin, sizeof(struct in_addr));
1069: ipt->ipt_ptr += sizeof(struct in_addr);
1070: break;
1071:
1072: case IPOPT_TS_PRESPEC:
1.66 thorpej 1073: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1074: sizeof(struct in_addr) > ipt->ipt_len)
1075: goto bad;
1076: bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
1077: sizeof(struct in_addr));
1078: if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1079: continue;
1080: ipt->ipt_ptr += sizeof(struct in_addr);
1081: break;
1082:
1083: default:
1084: goto bad;
1085: }
1086: ntime = iptime();
1087: bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
1088: sizeof(n_time));
1089: ipt->ipt_ptr += sizeof(n_time);
1090: }
1091: }
1092: if (forward) {
1.26 thorpej 1093: if (ip_forwsrcrt == 0) {
1094: type = ICMP_UNREACH;
1095: code = ICMP_UNREACH_SRCFAIL;
1096: goto bad;
1097: }
1.1 cgd 1098: ip_forward(m, 1);
1099: return (1);
1.13 mycroft 1100: }
1101: return (0);
1.1 cgd 1102: bad:
1.13 mycroft 1103: icmp_error(m, type, code, 0, 0);
1104: ipstat.ips_badoptions++;
1.1 cgd 1105: return (1);
1106: }
1107:
1108: /*
1109: * Given address of next destination (final or next hop),
1110: * return internet address info of interface to be used to get there.
1111: */
1112: struct in_ifaddr *
1113: ip_rtaddr(dst)
1114: struct in_addr dst;
1115: {
1116: register struct sockaddr_in *sin;
1117:
1.19 mycroft 1118: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1119:
1.35 mycroft 1120: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1121: if (ipforward_rt.ro_rt) {
1122: RTFREE(ipforward_rt.ro_rt);
1123: ipforward_rt.ro_rt = 0;
1124: }
1125: sin->sin_family = AF_INET;
1126: sin->sin_len = sizeof(*sin);
1127: sin->sin_addr = dst;
1128:
1129: rtalloc(&ipforward_rt);
1130: }
1131: if (ipforward_rt.ro_rt == 0)
1132: return ((struct in_ifaddr *)0);
1.19 mycroft 1133: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1134: }
1135:
1136: /*
1137: * Save incoming source route for use in replies,
1138: * to be picked up later by ip_srcroute if the receiver is interested.
1139: */
1.13 mycroft 1140: void
1.1 cgd 1141: save_rte(option, dst)
1142: u_char *option;
1143: struct in_addr dst;
1144: {
1145: unsigned olen;
1146:
1147: olen = option[IPOPT_OLEN];
1148: #ifdef DIAGNOSTIC
1149: if (ipprintfs)
1.39 christos 1150: printf("save_rte: olen %d\n", olen);
1.89 itojun 1151: #endif /* 0 */
1.1 cgd 1152: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1153: return;
1154: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1155: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1156: ip_srcrt.dst = dst;
1157: }
1158:
1159: /*
1160: * Retrieve incoming source route for use in replies,
1161: * in the same form used by setsockopt.
1162: * The first hop is placed before the options, will be removed later.
1163: */
1164: struct mbuf *
1165: ip_srcroute()
1166: {
1167: register struct in_addr *p, *q;
1168: register struct mbuf *m;
1169:
1170: if (ip_nhops == 0)
1171: return ((struct mbuf *)0);
1172: m = m_get(M_DONTWAIT, MT_SOOPTS);
1173: if (m == 0)
1174: return ((struct mbuf *)0);
1175:
1.13 mycroft 1176: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1177:
1178: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1179: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1180: OPTSIZ;
1181: #ifdef DIAGNOSTIC
1182: if (ipprintfs)
1.39 christos 1183: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1184: #endif
1185:
1186: /*
1187: * First save first hop for return route
1188: */
1189: p = &ip_srcrt.route[ip_nhops - 1];
1190: *(mtod(m, struct in_addr *)) = *p--;
1191: #ifdef DIAGNOSTIC
1192: if (ipprintfs)
1.39 christos 1193: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1194: #endif
1195:
1196: /*
1197: * Copy option fields and padding (nop) to mbuf.
1198: */
1199: ip_srcrt.nop = IPOPT_NOP;
1200: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1201: bcopy((caddr_t)&ip_srcrt.nop,
1202: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1203: q = (struct in_addr *)(mtod(m, caddr_t) +
1204: sizeof(struct in_addr) + OPTSIZ);
1205: #undef OPTSIZ
1206: /*
1207: * Record return path as an IP source route,
1208: * reversing the path (pointers are now aligned).
1209: */
1210: while (p >= ip_srcrt.route) {
1211: #ifdef DIAGNOSTIC
1212: if (ipprintfs)
1.39 christos 1213: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1214: #endif
1215: *q++ = *p--;
1216: }
1217: /*
1218: * Last hop goes to final destination.
1219: */
1220: *q = ip_srcrt.dst;
1221: #ifdef DIAGNOSTIC
1222: if (ipprintfs)
1.39 christos 1223: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1224: #endif
1225: return (m);
1226: }
1227:
1228: /*
1229: * Strip out IP options, at higher
1230: * level protocol in the kernel.
1231: * Second argument is buffer to which options
1232: * will be moved, and return value is their length.
1233: * XXX should be deleted; last arg currently ignored.
1234: */
1.8 mycroft 1235: void
1.1 cgd 1236: ip_stripoptions(m, mopt)
1237: register struct mbuf *m;
1238: struct mbuf *mopt;
1239: {
1240: register int i;
1241: struct ip *ip = mtod(m, struct ip *);
1242: register caddr_t opts;
1243: int olen;
1244:
1.79 mycroft 1245: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1246: opts = (caddr_t)(ip + 1);
1247: i = m->m_len - (sizeof (struct ip) + olen);
1248: bcopy(opts + olen, opts, (unsigned)i);
1249: m->m_len -= olen;
1250: if (m->m_flags & M_PKTHDR)
1251: m->m_pkthdr.len -= olen;
1.79 mycroft 1252: ip->ip_len -= olen;
1253: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1254: }
1255:
1.23 mycroft 1256: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1257: 0, 0, 0, 0,
1258: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1259: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1260: EMSGSIZE, EHOSTUNREACH, 0, 0,
1261: 0, 0, 0, 0,
1262: ENOPROTOOPT
1263: };
1264:
1265: /*
1266: * Forward a packet. If some error occurs return the sender
1267: * an icmp packet. Note we can't always generate a meaningful
1268: * icmp message because icmp doesn't have a large enough repertoire
1269: * of codes and types.
1270: *
1271: * If not forwarding, just drop the packet. This could be confusing
1272: * if ipforwarding was zero but some routing protocol was advancing
1273: * us as a gateway to somewhere. However, we must let the routing
1274: * protocol deal with that.
1275: *
1276: * The srcrt parameter indicates whether the packet is being forwarded
1277: * via a source route.
1278: */
1.13 mycroft 1279: void
1.1 cgd 1280: ip_forward(m, srcrt)
1281: struct mbuf *m;
1282: int srcrt;
1283: {
1284: register struct ip *ip = mtod(m, struct ip *);
1285: register struct sockaddr_in *sin;
1286: register struct rtentry *rt;
1.28 christos 1287: int error, type = 0, code = 0;
1.1 cgd 1288: struct mbuf *mcopy;
1.13 mycroft 1289: n_long dest;
1290: struct ifnet *destifp;
1.89 itojun 1291: #ifdef IPSEC
1292: struct ifnet dummyifp;
1293: #endif
1.1 cgd 1294:
1.13 mycroft 1295: dest = 0;
1.1 cgd 1296: #ifdef DIAGNOSTIC
1297: if (ipprintfs)
1.70 thorpej 1298: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1299: ntohl(ip->ip_src.s_addr),
1300: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1301: #endif
1.93 ! sommerfe 1302: if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1.1 cgd 1303: ipstat.ips_cantforward++;
1304: m_freem(m);
1305: return;
1306: }
1307: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1308: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1309: return;
1310: }
1311: ip->ip_ttl -= IPTTLDEC;
1312:
1.19 mycroft 1313: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1314: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1315: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1316: if (ipforward_rt.ro_rt) {
1317: RTFREE(ipforward_rt.ro_rt);
1318: ipforward_rt.ro_rt = 0;
1319: }
1320: sin->sin_family = AF_INET;
1.35 mycroft 1321: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1322: sin->sin_addr = ip->ip_dst;
1323:
1324: rtalloc(&ipforward_rt);
1325: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1326: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1327: return;
1328: }
1329: rt = ipforward_rt.ro_rt;
1330: }
1331:
1332: /*
1.34 mycroft 1333: * Save at most 68 bytes of the packet in case
1.1 cgd 1334: * we need to generate an ICMP message to the src.
1335: */
1.34 mycroft 1336: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1337:
1338: /*
1339: * If forwarding packet using same interface that it came in on,
1340: * perhaps should send a redirect to sender to shortcut a hop.
1341: * Only send redirect if source is sending directly to us,
1342: * and if packet was not source routed (or has any options).
1343: * Also, don't send redirect if forwarding using a default route
1344: * or a route modified by a redirect.
1345: */
1346: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1347: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1348: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1349: ipsendredirects && !srcrt) {
1.19 mycroft 1350: if (rt->rt_ifa &&
1351: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1352: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1353: if (rt->rt_flags & RTF_GATEWAY)
1354: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1355: else
1356: dest = ip->ip_dst.s_addr;
1357: /*
1358: * Router requirements says to only send host
1359: * redirects.
1360: */
1361: type = ICMP_REDIRECT;
1362: code = ICMP_REDIRECT_HOST;
1.1 cgd 1363: #ifdef DIAGNOSTIC
1.77 thorpej 1364: if (ipprintfs)
1365: printf("redirect (%d) to %x\n", code,
1366: (u_int32_t)dest);
1.1 cgd 1367: #endif
1368: }
1369: }
1370:
1.89 itojun 1371: #ifdef IPSEC
1372: m->m_pkthdr.rcvif = NULL;
1373: #endif /*IPSEC*/
1.27 thorpej 1374: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1375: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1376: if (error)
1377: ipstat.ips_cantforward++;
1378: else {
1379: ipstat.ips_forward++;
1380: if (type)
1381: ipstat.ips_redirectsent++;
1382: else {
1.63 matt 1383: if (mcopy) {
1384: #ifdef GATEWAY
1.64 thorpej 1385: if (mcopy->m_flags & M_CANFASTFWD)
1386: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1387: #endif
1.1 cgd 1388: m_freem(mcopy);
1.63 matt 1389: }
1.1 cgd 1390: return;
1391: }
1392: }
1393: if (mcopy == NULL)
1394: return;
1.13 mycroft 1395: destifp = NULL;
1396:
1.1 cgd 1397: switch (error) {
1398:
1399: case 0: /* forwarded, but need redirect */
1400: /* type, code set above */
1401: break;
1402:
1403: case ENETUNREACH: /* shouldn't happen, checked above */
1404: case EHOSTUNREACH:
1405: case ENETDOWN:
1406: case EHOSTDOWN:
1407: default:
1408: type = ICMP_UNREACH;
1409: code = ICMP_UNREACH_HOST;
1410: break;
1411:
1412: case EMSGSIZE:
1413: type = ICMP_UNREACH;
1414: code = ICMP_UNREACH_NEEDFRAG;
1.89 itojun 1415: #ifndef IPSEC
1.13 mycroft 1416: if (ipforward_rt.ro_rt)
1417: destifp = ipforward_rt.ro_rt->rt_ifp;
1.89 itojun 1418: #else
1419: /*
1420: * If the packet is routed over IPsec tunnel, tell the
1421: * originator the tunnel MTU.
1422: * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1423: * XXX quickhack!!!
1424: */
1425: if (ipforward_rt.ro_rt) {
1426: struct secpolicy *sp;
1427: int ipsecerror;
1428: int ipsechdr;
1429: struct route *ro;
1430:
1431: sp = ipsec4_getpolicybyaddr(mcopy,
1432: IP_FORWARDING,
1433: &ipsecerror);
1434:
1435: if (sp == NULL)
1436: destifp = ipforward_rt.ro_rt->rt_ifp;
1437: else {
1438: /* count IPsec header size */
1439: ipsechdr = ipsec4_hdrsiz(mcopy, NULL);
1440:
1441: /*
1442: * find the correct route for outer IPv4
1443: * header, compute tunnel MTU.
1444: *
1445: * XXX BUG ALERT
1446: * The "dummyifp" code relies upon the fact
1447: * that icmp_error() touches only ifp->if_mtu.
1448: */
1449: /*XXX*/
1450: destifp = NULL;
1451: if (sp->req != NULL
1452: && sp->req->sa != NULL) {
1453: ro = &sp->req->sa->saidx->sa_route;
1454: if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1455: dummyifp.if_mtu =
1456: ro->ro_rt->rt_ifp->if_mtu;
1457: dummyifp.if_mtu -= ipsechdr;
1458: destifp = &dummyifp;
1459: }
1460: }
1461:
1462: key_freesp(sp);
1463: }
1464: }
1465: #endif /*IPSEC*/
1.1 cgd 1466: ipstat.ips_cantfrag++;
1467: break;
1468:
1469: case ENOBUFS:
1470: type = ICMP_SOURCEQUENCH;
1471: code = 0;
1472: break;
1473: }
1.13 mycroft 1474: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1475: }
1476:
1477: void
1478: ip_savecontrol(inp, mp, ip, m)
1479: register struct inpcb *inp;
1480: register struct mbuf **mp;
1481: register struct ip *ip;
1482: register struct mbuf *m;
1483: {
1484:
1485: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1486: struct timeval tv;
1487:
1488: microtime(&tv);
1489: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1490: SCM_TIMESTAMP, SOL_SOCKET);
1491: if (*mp)
1492: mp = &(*mp)->m_next;
1493: }
1494: if (inp->inp_flags & INP_RECVDSTADDR) {
1495: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1496: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1497: if (*mp)
1498: mp = &(*mp)->m_next;
1499: }
1500: #ifdef notyet
1501: /*
1502: * XXX
1503: * Moving these out of udp_input() made them even more broken
1504: * than they already were.
1505: * - fenner@parc.xerox.com
1506: */
1507: /* options were tossed already */
1508: if (inp->inp_flags & INP_RECVOPTS) {
1509: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1510: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1511: if (*mp)
1512: mp = &(*mp)->m_next;
1513: }
1514: /* ip_srcroute doesn't do what we want here, need to fix */
1515: if (inp->inp_flags & INP_RECVRETOPTS) {
1516: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1517: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1518: if (*mp)
1519: mp = &(*mp)->m_next;
1520: }
1521: #endif
1522: if (inp->inp_flags & INP_RECVIF) {
1523: struct sockaddr_dl sdl;
1524:
1525: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1526: sdl.sdl_family = AF_LINK;
1527: sdl.sdl_index = m->m_pkthdr.rcvif ?
1528: m->m_pkthdr.rcvif->if_index : 0;
1529: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1530: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1531: IP_RECVIF, IPPROTO_IP);
1532: if (*mp)
1533: mp = &(*mp)->m_next;
1534: }
1.13 mycroft 1535: }
1536:
1537: int
1538: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1539: int *name;
1540: u_int namelen;
1541: void *oldp;
1542: size_t *oldlenp;
1543: void *newp;
1544: size_t newlen;
1545: {
1.88 sommerfe 1546: extern int subnetsarelocal, hostzeroisbroadcast;
1.52 thorpej 1547:
1.54 lukem 1548: int error, old;
1549:
1.13 mycroft 1550: /* All sysctl names at this level are terminal. */
1551: if (namelen != 1)
1552: return (ENOTDIR);
1553:
1554: switch (name[0]) {
1555: case IPCTL_FORWARDING:
1556: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1557: case IPCTL_SENDREDIRECTS:
1558: return (sysctl_int(oldp, oldlenp, newp, newlen,
1559: &ipsendredirects));
1560: case IPCTL_DEFTTL:
1561: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1562: #ifdef notyet
1563: case IPCTL_DEFMTU:
1564: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1565: #endif
1.26 thorpej 1566: case IPCTL_FORWSRCRT:
1.47 cjs 1567: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1568: if (securelevel > 0)
1.46 cjs 1569: return (sysctl_rdint(oldp, oldlenp, newp,
1570: ip_forwsrcrt));
1571: else
1572: return (sysctl_int(oldp, oldlenp, newp, newlen,
1573: &ip_forwsrcrt));
1.27 thorpej 1574: case IPCTL_DIRECTEDBCAST:
1575: return (sysctl_int(oldp, oldlenp, newp, newlen,
1576: &ip_directedbcast));
1.47 cjs 1577: case IPCTL_ALLOWSRCRT:
1578: return (sysctl_int(oldp, oldlenp, newp, newlen,
1579: &ip_allowsrcrt));
1.52 thorpej 1580: case IPCTL_SUBNETSARELOCAL:
1581: return (sysctl_int(oldp, oldlenp, newp, newlen,
1582: &subnetsarelocal));
1.53 kml 1583: case IPCTL_MTUDISC:
1.60 kml 1584: error = sysctl_int(oldp, oldlenp, newp, newlen,
1585: &ip_mtudisc);
1586: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1587: ip_mtudisc_timeout_q =
1588: rt_timer_queue_create(ip_mtudisc_timeout);
1589: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1590: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1591: ip_mtudisc_timeout_q = NULL;
1592: }
1593: return error;
1.54 lukem 1594: case IPCTL_ANONPORTMIN:
1595: old = anonportmin;
1596: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1597: if (anonportmin >= anonportmax || anonportmin > 65535
1598: #ifndef IPNOPRIVPORTS
1599: || anonportmin < IPPORT_RESERVED
1600: #endif
1601: ) {
1602: anonportmin = old;
1603: return (EINVAL);
1604: }
1605: return (error);
1606: case IPCTL_ANONPORTMAX:
1607: old = anonportmax;
1608: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1609: if (anonportmin >= anonportmax || anonportmax > 65535
1610: #ifndef IPNOPRIVPORTS
1611: || anonportmax < IPPORT_RESERVED
1612: #endif
1613: ) {
1614: anonportmax = old;
1615: return (EINVAL);
1616: }
1.60 kml 1617: return (error);
1618: case IPCTL_MTUDISCTIMEOUT:
1619: error = sysctl_int(oldp, oldlenp, newp, newlen,
1620: &ip_mtudisc_timeout);
1621: if (ip_mtudisc_timeout_q != NULL)
1622: rt_timer_queue_change(ip_mtudisc_timeout_q,
1623: ip_mtudisc_timeout);
1.54 lukem 1624: return (error);
1.65 matt 1625: #ifdef GATEWAY
1626: case IPCTL_MAXFLOWS:
1.67 thorpej 1627: {
1628: int s;
1629:
1.65 matt 1630: error = sysctl_int(oldp, oldlenp, newp, newlen,
1631: &ip_maxflows);
1.67 thorpej 1632: s = splsoftnet();
1.65 matt 1633: ipflow_reap(0);
1.67 thorpej 1634: splx(s);
1.65 matt 1635: return (error);
1.67 thorpej 1636: }
1.89 itojun 1637: #endif
1.90 itojun 1638: case IPCTL_HOSTZEROBROADCAST:
1639: return (sysctl_int(oldp, oldlenp, newp, newlen,
1640: &hostzeroisbroadcast));
1.89 itojun 1641: #if NGIF > 0
1642: case IPCTL_GIF_TTL:
1643: return(sysctl_int(oldp, oldlenp, newp, newlen,
1.90 itojun 1644: &ip_gif_ttl));
1.65 matt 1645: #endif
1.88 sommerfe 1646:
1.13 mycroft 1647: default:
1648: return (EOPNOTSUPP);
1649: }
1650: /* NOTREACHED */
1.1 cgd 1651: }
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