Annotation of src/sys/netinet/ip_input.c, Revision 1.156
1.156 ! itojun 1: /* $NetBSD: ip_input.c,v 1.155 2002/08/14 00:23:31 itojun Exp $ */
1.89 itojun 2:
3: /*
4: * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5: * All rights reserved.
1.152 itojun 6: *
1.89 itojun 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.
1.152 itojun 18: *
1.89 itojun 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: */
1.141 lukem 103:
104: #include <sys/cdefs.h>
1.156 ! itojun 105: __KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.155 2002/08/14 00:23:31 itojun Exp $");
1.55 scottr 106:
1.62 matt 107: #include "opt_gateway.h"
1.69 mrg 108: #include "opt_pfil_hooks.h"
1.91 thorpej 109: #include "opt_ipsec.h"
1.55 scottr 110: #include "opt_mrouting.h"
1.135 thorpej 111: #include "opt_inet_csum.h"
1.1 cgd 112:
1.5 mycroft 113: #include <sys/param.h>
114: #include <sys/systm.h>
115: #include <sys/malloc.h>
116: #include <sys/mbuf.h>
117: #include <sys/domain.h>
118: #include <sys/protosw.h>
119: #include <sys/socket.h>
1.44 thorpej 120: #include <sys/socketvar.h>
1.5 mycroft 121: #include <sys/errno.h>
122: #include <sys/time.h>
123: #include <sys/kernel.h>
1.72 thorpej 124: #include <sys/pool.h>
1.28 christos 125: #include <sys/sysctl.h>
1.1 cgd 126:
1.5 mycroft 127: #include <net/if.h>
1.44 thorpej 128: #include <net/if_dl.h>
1.5 mycroft 129: #include <net/route.h>
1.45 mrg 130: #include <net/pfil.h>
1.1 cgd 131:
1.5 mycroft 132: #include <netinet/in.h>
133: #include <netinet/in_systm.h>
134: #include <netinet/ip.h>
135: #include <netinet/in_pcb.h>
136: #include <netinet/in_var.h>
137: #include <netinet/ip_var.h>
138: #include <netinet/ip_icmp.h>
1.89 itojun 139: /* just for gif_ttl */
140: #include <netinet/in_gif.h>
141: #include "gif.h"
1.144 martin 142: #include <net/if_gre.h>
143: #include "gre.h"
1.111 jdolecek 144:
145: #ifdef MROUTING
146: #include <netinet/ip_mroute.h>
147: #endif
1.89 itojun 148:
149: #ifdef IPSEC
150: #include <netinet6/ipsec.h>
151: #include <netkey/key.h>
152: #endif
1.44 thorpej 153:
1.1 cgd 154: #ifndef IPFORWARDING
155: #ifdef GATEWAY
156: #define IPFORWARDING 1 /* forward IP packets not for us */
157: #else /* GATEWAY */
158: #define IPFORWARDING 0 /* don't forward IP packets not for us */
159: #endif /* GATEWAY */
160: #endif /* IPFORWARDING */
161: #ifndef IPSENDREDIRECTS
162: #define IPSENDREDIRECTS 1
163: #endif
1.26 thorpej 164: #ifndef IPFORWSRCRT
1.47 cjs 165: #define IPFORWSRCRT 1 /* forward source-routed packets */
166: #endif
167: #ifndef IPALLOWSRCRT
1.48 mrg 168: #define IPALLOWSRCRT 1 /* allow source-routed packets */
1.26 thorpej 169: #endif
1.53 kml 170: #ifndef IPMTUDISC
1.153 itojun 171: #define IPMTUDISC 1
1.53 kml 172: #endif
1.60 kml 173: #ifndef IPMTUDISCTIMEOUT
1.61 kml 174: #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
1.60 kml 175: #endif
1.53 kml 176:
1.27 thorpej 177: /*
178: * Note: DIRECTED_BROADCAST is handled this way so that previous
179: * configuration using this option will Just Work.
180: */
181: #ifndef IPDIRECTEDBCAST
182: #ifdef DIRECTED_BROADCAST
183: #define IPDIRECTEDBCAST 1
184: #else
185: #define IPDIRECTEDBCAST 0
186: #endif /* DIRECTED_BROADCAST */
187: #endif /* IPDIRECTEDBCAST */
1.1 cgd 188: int ipforwarding = IPFORWARDING;
189: int ipsendredirects = IPSENDREDIRECTS;
1.13 mycroft 190: int ip_defttl = IPDEFTTL;
1.26 thorpej 191: int ip_forwsrcrt = IPFORWSRCRT;
1.27 thorpej 192: int ip_directedbcast = IPDIRECTEDBCAST;
1.47 cjs 193: int ip_allowsrcrt = IPALLOWSRCRT;
1.53 kml 194: int ip_mtudisc = IPMTUDISC;
1.156 ! itojun 195: int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1 cgd 196: #ifdef DIAGNOSTIC
197: int ipprintfs = 0;
198: #endif
199:
1.60 kml 200: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
201:
1.1 cgd 202: extern struct domain inetdomain;
203: int ipqmaxlen = IFQ_MAXLEN;
1.150 matt 204: u_long in_ifaddrhash; /* size of hash table - 1 */
205: int in_ifaddrentries; /* total number of addrs */
1.22 mycroft 206: struct in_ifaddrhead in_ifaddr;
1.57 tls 207: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.13 mycroft 208: struct ifqueue ipintrq;
1.63 matt 209: struct ipstat ipstat;
210: u_int16_t ip_id;
1.75 thorpej 211:
1.121 thorpej 212: #ifdef PFIL_HOOKS
213: struct pfil_head inet_pfil_hook;
214: #endif
215:
1.63 matt 216: struct ipqhead ipq;
1.75 thorpej 217: int ipq_locked;
1.131 itojun 218: int ip_nfragpackets = 0;
1.133 itojun 219: int ip_maxfragpackets = 200;
1.75 thorpej 220:
221: static __inline int ipq_lock_try __P((void));
222: static __inline void ipq_unlock __P((void));
223:
224: static __inline int
225: ipq_lock_try()
226: {
227: int s;
228:
1.132 thorpej 229: /*
1.149 wiz 230: * Use splvm() -- we're blocking things that would cause
1.132 thorpej 231: * mbuf allocation.
232: */
233: s = splvm();
1.75 thorpej 234: if (ipq_locked) {
235: splx(s);
236: return (0);
237: }
238: ipq_locked = 1;
239: splx(s);
240: return (1);
241: }
242:
243: static __inline void
244: ipq_unlock()
245: {
246: int s;
247:
1.132 thorpej 248: s = splvm();
1.75 thorpej 249: ipq_locked = 0;
250: splx(s);
251: }
252:
253: #ifdef DIAGNOSTIC
254: #define IPQ_LOCK() \
255: do { \
256: if (ipq_lock_try() == 0) { \
257: printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
258: panic("ipq_lock"); \
259: } \
260: } while (0)
261: #define IPQ_LOCK_CHECK() \
262: do { \
263: if (ipq_locked == 0) { \
264: printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
265: panic("ipq lock check"); \
266: } \
267: } while (0)
268: #else
269: #define IPQ_LOCK() (void) ipq_lock_try()
270: #define IPQ_LOCK_CHECK() /* nothing */
271: #endif
272:
273: #define IPQ_UNLOCK() ipq_unlock()
1.1 cgd 274:
1.72 thorpej 275: struct pool ipqent_pool;
276:
1.135 thorpej 277: #ifdef INET_CSUM_COUNTERS
278: #include <sys/device.h>
279:
280: struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
281: NULL, "inet", "hwcsum bad");
282: struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
283: NULL, "inet", "hwcsum ok");
284: struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
285: NULL, "inet", "swcsum");
286:
287: #define INET_CSUM_COUNTER_INCR(ev) (ev)->ev_count++
288:
289: #else
290:
291: #define INET_CSUM_COUNTER_INCR(ev) /* nothing */
292:
293: #endif /* INET_CSUM_COUNTERS */
294:
1.1 cgd 295: /*
296: * We need to save the IP options in case a protocol wants to respond
297: * to an incoming packet over the same route if the packet got here
298: * using IP source routing. This allows connection establishment and
299: * maintenance when the remote end is on a network that is not known
300: * to us.
301: */
302: int ip_nhops = 0;
303: static struct ip_srcrt {
304: struct in_addr dst; /* final destination */
305: char nop; /* one NOP to align */
306: char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
307: struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
308: } ip_srcrt;
309:
1.13 mycroft 310: static void save_rte __P((u_char *, struct in_addr));
1.35 mycroft 311:
1.1 cgd 312: /*
313: * IP initialization: fill in IP protocol switch table.
314: * All protocols not implemented in kernel go to raw IP protocol handler.
315: */
1.8 mycroft 316: void
1.1 cgd 317: ip_init()
318: {
1.109 augustss 319: struct protosw *pr;
320: int i;
1.1 cgd 321:
1.72 thorpej 322: pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
1.146 thorpej 323: NULL);
1.72 thorpej 324:
1.1 cgd 325: pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
326: if (pr == 0)
327: panic("ip_init");
328: for (i = 0; i < IPPROTO_MAX; i++)
329: ip_protox[i] = pr - inetsw;
330: for (pr = inetdomain.dom_protosw;
331: pr < inetdomain.dom_protoswNPROTOSW; pr++)
332: if (pr->pr_domain->dom_family == PF_INET &&
333: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
334: ip_protox[pr->pr_protocol] = pr - inetsw;
1.25 cgd 335: LIST_INIT(&ipq);
1.1 cgd 336: ip_id = time.tv_sec & 0xffff;
337: ipintrq.ifq_maxlen = ipqmaxlen;
1.22 mycroft 338: TAILQ_INIT(&in_ifaddr);
1.120 ad 339: in_ifaddrhashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IFADDR,
340: M_WAITOK, &in_ifaddrhash);
1.60 kml 341: if (ip_mtudisc != 0)
1.152 itojun 342: ip_mtudisc_timeout_q =
1.60 kml 343: rt_timer_queue_create(ip_mtudisc_timeout);
1.73 thorpej 344: #ifdef GATEWAY
345: ipflow_init();
346: #endif
1.121 thorpej 347:
348: #ifdef PFIL_HOOKS
349: /* Register our Packet Filter hook. */
1.126 thorpej 350: inet_pfil_hook.ph_type = PFIL_TYPE_AF;
351: inet_pfil_hook.ph_af = AF_INET;
1.121 thorpej 352: i = pfil_head_register(&inet_pfil_hook);
353: if (i != 0)
354: printf("ip_init: WARNING: unable to register pfil hook, "
355: "error %d\n", i);
356: #endif /* PFIL_HOOKS */
1.135 thorpej 357:
358: #ifdef INET_CSUM_COUNTERS
359: evcnt_attach_static(&ip_hwcsum_bad);
360: evcnt_attach_static(&ip_hwcsum_ok);
361: evcnt_attach_static(&ip_swcsum);
362: #endif /* INET_CSUM_COUNTERS */
1.1 cgd 363: }
364:
365: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
366: struct route ipforward_rt;
367:
368: /*
1.89 itojun 369: * IP software interrupt routine
370: */
371: void
372: ipintr()
373: {
374: int s;
375: struct mbuf *m;
376:
377: while (1) {
1.132 thorpej 378: s = splnet();
1.89 itojun 379: IF_DEQUEUE(&ipintrq, m);
380: splx(s);
381: if (m == 0)
382: return;
383: ip_input(m);
384: }
385: }
386:
387: /*
1.1 cgd 388: * Ip input routine. Checksum and byte swap header. If fragmented
389: * try to reassemble. Process options. Pass to next level.
390: */
1.8 mycroft 391: void
1.89 itojun 392: ip_input(struct mbuf *m)
1.1 cgd 393: {
1.109 augustss 394: struct ip *ip = NULL;
395: struct ipq *fp;
396: struct in_ifaddr *ia;
397: struct ifaddr *ifa;
1.25 cgd 398: struct ipqent *ipqe;
1.89 itojun 399: int hlen = 0, mff, len;
1.100 itojun 400: int downmatch;
1.1 cgd 401:
402: #ifdef DIAGNOSTIC
403: if ((m->m_flags & M_PKTHDR) == 0)
404: panic("ipintr no HDR");
405: #endif
1.89 itojun 406: #ifdef IPSEC
407: /*
408: * should the inner packet be considered authentic?
409: * see comment in ah4_input().
410: */
411: if (m) {
412: m->m_flags &= ~M_AUTHIPHDR;
413: m->m_flags &= ~M_AUTHIPDGM;
414: }
415: #endif
1.1 cgd 416: /*
417: * If no IP addresses have been set yet but the interfaces
418: * are receiving, can't do anything with incoming packets yet.
419: */
1.140 matt 420: if (TAILQ_FIRST(&in_ifaddr) == 0)
1.1 cgd 421: goto bad;
422: ipstat.ips_total++;
1.154 thorpej 423: /*
424: * If the IP header is not aligned, slurp it up into a new
425: * mbuf with space for link headers, in the event we forward
426: * it. Otherwise, if it is aligned, make sure the entire
427: * base IP header is in the first mbuf of the chain.
428: */
429: if (IP_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) {
430: if ((m = m_copyup(m, sizeof(struct ip),
431: (max_linkhdr + 3) & ~3)) == NULL) {
432: /* XXXJRT new stat, please */
433: ipstat.ips_toosmall++;
434: return;
435: }
436: } else if (__predict_false(m->m_len < sizeof (struct ip))) {
437: if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
438: ipstat.ips_toosmall++;
439: return;
440: }
1.1 cgd 441: }
442: ip = mtod(m, struct ip *);
1.13 mycroft 443: if (ip->ip_v != IPVERSION) {
444: ipstat.ips_badvers++;
445: goto bad;
446: }
1.1 cgd 447: hlen = ip->ip_hl << 2;
448: if (hlen < sizeof(struct ip)) { /* minimum header length */
449: ipstat.ips_badhlen++;
450: goto bad;
451: }
452: if (hlen > m->m_len) {
453: if ((m = m_pullup(m, hlen)) == 0) {
454: ipstat.ips_badhlen++;
1.89 itojun 455: return;
1.1 cgd 456: }
457: ip = mtod(m, struct ip *);
458: }
1.98 thorpej 459:
1.85 hwr 460: /*
1.99 thorpej 461: * RFC1122: packets with a multicast source address are
1.98 thorpej 462: * not allowed.
1.85 hwr 463: */
464: if (IN_MULTICAST(ip->ip_src.s_addr)) {
1.130 itojun 465: ipstat.ips_badaddr++;
1.85 hwr 466: goto bad;
1.129 itojun 467: }
468:
469: /* 127/8 must not appear on wire - RFC1122 */
470: if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
471: (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
1.130 itojun 472: if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
473: ipstat.ips_badaddr++;
1.129 itojun 474: goto bad;
1.130 itojun 475: }
1.85 hwr 476: }
477:
1.135 thorpej 478: switch (m->m_pkthdr.csum_flags &
1.137 thorpej 479: ((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
1.135 thorpej 480: M_CSUM_IPv4_BAD)) {
481: case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
482: INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
483: goto badcsum;
484:
485: case M_CSUM_IPv4:
486: /* Checksum was okay. */
487: INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
488: break;
489:
490: default:
491: /* Must compute it ourselves. */
492: INET_CSUM_COUNTER_INCR(&ip_swcsum);
493: if (in_cksum(m, hlen) != 0)
494: goto bad;
495: break;
1.1 cgd 496: }
497:
1.121 thorpej 498: /* Retrieve the packet length. */
499: len = ntohs(ip->ip_len);
1.81 proff 500:
501: /*
502: * Check for additional length bogosity
503: */
1.84 proff 504: if (len < hlen) {
1.81 proff 505: ipstat.ips_badlen++;
506: goto bad;
507: }
1.1 cgd 508:
509: /*
510: * Check that the amount of data in the buffers
511: * is as at least much as the IP header would have us expect.
512: * Trim mbufs if longer than we expect.
513: * Drop packet if shorter than we expect.
514: */
1.35 mycroft 515: if (m->m_pkthdr.len < len) {
1.1 cgd 516: ipstat.ips_tooshort++;
517: goto bad;
518: }
1.35 mycroft 519: if (m->m_pkthdr.len > len) {
1.1 cgd 520: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 521: m->m_len = len;
522: m->m_pkthdr.len = len;
1.1 cgd 523: } else
1.35 mycroft 524: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 525: }
526:
1.94 itojun 527: #ifdef IPSEC
1.149 wiz 528: /* ipflow (IP fast forwarding) is not compatible with IPsec. */
1.94 itojun 529: m->m_flags &= ~M_CANFASTFWD;
530: #else
1.64 thorpej 531: /*
532: * Assume that we can create a fast-forward IP flow entry
533: * based on this packet.
534: */
535: m->m_flags |= M_CANFASTFWD;
1.94 itojun 536: #endif
1.64 thorpej 537:
1.36 mrg 538: #ifdef PFIL_HOOKS
1.33 mrg 539: /*
1.64 thorpej 540: * Run through list of hooks for input packets. If there are any
541: * filters which require that additional packets in the flow are
542: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
543: * Note that filters must _never_ set this flag, as another filter
544: * in the list may have previously cleared it.
1.33 mrg 545: */
1.127 itojun 546: /*
547: * let ipfilter look at packet on the wire,
548: * not the decapsulated packet.
549: */
550: #ifdef IPSEC
1.136 itojun 551: if (!ipsec_getnhist(m))
1.127 itojun 552: #else
553: if (1)
554: #endif
555: {
556: if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
557: PFIL_IN) != 0)
1.121 thorpej 558: return;
1.127 itojun 559: if (m == NULL)
560: return;
561: ip = mtod(m, struct ip *);
1.142 darrenr 562: hlen = ip->ip_hl << 2;
1.127 itojun 563: }
1.36 mrg 564: #endif /* PFIL_HOOKS */
1.123 thorpej 565:
566: #ifdef ALTQ
567: /* XXX Temporary until ALTQ is changed to use a pfil hook */
568: if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
569: /* packet dropped by traffic conditioner */
570: return;
571: }
572: #endif
1.121 thorpej 573:
574: /*
1.1 cgd 575: * Process options and, if not destined for us,
576: * ship it on. ip_dooptions returns 1 when an
577: * error was detected (causing an icmp message
578: * to be sent and the original packet to be freed).
579: */
580: ip_nhops = 0; /* for source routed packets */
581: if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.89 itojun 582: return;
1.1 cgd 583:
584: /*
585: * Check our list of addresses, to see if the packet is for us.
1.100 itojun 586: *
587: * Traditional 4.4BSD did not consult IFF_UP at all.
588: * The behavior here is to treat addresses on !IFF_UP interface
589: * as not mine.
1.1 cgd 590: */
1.100 itojun 591: downmatch = 0;
1.140 matt 592: LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
1.97 itojun 593: if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
594: if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
595: break;
1.100 itojun 596: else
597: downmatch++;
1.97 itojun 598: }
599: }
1.86 thorpej 600: if (ia != NULL)
601: goto ours;
1.57 tls 602: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
1.140 matt 603: TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) {
604: if (ifa->ifa_addr->sa_family != AF_INET)
605: continue;
1.57 tls 606: ia = ifatoia(ifa);
1.35 mycroft 607: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
608: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 609: /*
610: * Look for all-0's host part (old broadcast addr),
611: * either for subnet or net.
612: */
613: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 614: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 615: goto ours;
1.57 tls 616: /*
617: * An interface with IP address zero accepts
618: * all packets that arrive on that interface.
619: */
620: if (in_nullhost(ia->ia_addr.sin_addr))
621: goto ours;
1.1 cgd 622: }
623: }
1.18 mycroft 624: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 625: struct in_multi *inm;
626: #ifdef MROUTING
627: extern struct socket *ip_mrouter;
1.10 brezak 628:
1.147 matt 629: if (M_READONLY(m)) {
1.10 brezak 630: if ((m = m_pullup(m, hlen)) == 0) {
631: ipstat.ips_toosmall++;
1.89 itojun 632: return;
1.10 brezak 633: }
634: ip = mtod(m, struct ip *);
635: }
1.4 hpeyerl 636:
637: if (ip_mrouter) {
638: /*
639: * If we are acting as a multicast router, all
640: * incoming multicast packets are passed to the
641: * kernel-level multicast forwarding function.
642: * The packet is returned (relatively) intact; if
643: * ip_mforward() returns a non-zero value, the packet
644: * must be discarded, else it may be accepted below.
645: *
646: * (The IP ident field is put in the same byte order
647: * as expected when ip_mforward() is called from
648: * ip_output().)
649: */
1.13 mycroft 650: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
651: ipstat.ips_cantforward++;
1.4 hpeyerl 652: m_freem(m);
1.89 itojun 653: return;
1.4 hpeyerl 654: }
655:
656: /*
657: * The process-level routing demon needs to receive
658: * all multicast IGMP packets, whether or not this
659: * host belongs to their destination groups.
660: */
661: if (ip->ip_p == IPPROTO_IGMP)
662: goto ours;
1.13 mycroft 663: ipstat.ips_forward++;
1.4 hpeyerl 664: }
665: #endif
666: /*
667: * See if we belong to the destination multicast group on the
668: * arrival interface.
669: */
670: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
671: if (inm == NULL) {
1.13 mycroft 672: ipstat.ips_cantforward++;
1.4 hpeyerl 673: m_freem(m);
1.89 itojun 674: return;
1.4 hpeyerl 675: }
676: goto ours;
677: }
1.19 mycroft 678: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 679: in_nullhost(ip->ip_dst))
1.1 cgd 680: goto ours;
681:
682: /*
683: * Not for us; forward if possible and desirable.
684: */
685: if (ipforwarding == 0) {
686: ipstat.ips_cantforward++;
687: m_freem(m);
1.100 itojun 688: } else {
689: /*
690: * If ip_dst matched any of my address on !IFF_UP interface,
691: * and there's no IFF_UP interface that matches ip_dst,
692: * send icmp unreach. Forwarding it will result in in-kernel
693: * forwarding loop till TTL goes to 0.
694: */
695: if (downmatch) {
696: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
697: ipstat.ips_cantforward++;
698: return;
699: }
1.145 itojun 700: #ifdef IPSEC
701: if (ipsec4_in_reject(m, NULL)) {
702: ipsecstat.in_polvio++;
703: goto bad;
704: }
705: #endif
706:
1.1 cgd 707: ip_forward(m, 0);
1.100 itojun 708: }
1.89 itojun 709: return;
1.1 cgd 710:
711: ours:
712: /*
713: * If offset or IP_MF are set, must reassemble.
714: * Otherwise, nothing need be done.
715: * (We could look in the reassembly queue to see
716: * if the packet was previously fragmented,
717: * but it's not worth the time; just let them time out.)
718: */
1.155 itojun 719: if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
720: if (M_READONLY(m)) {
721: if ((m = m_pullup(m, hlen)) == NULL) {
722: ipstat.ips_toosmall++;
723: goto bad;
724: }
725: ip = mtod(m, struct ip *);
726: }
727:
1.1 cgd 728: /*
729: * Look for queue of fragments
730: * of this datagram.
731: */
1.75 thorpej 732: IPQ_LOCK();
1.140 matt 733: LIST_FOREACH(fp, &ipq, ipq_q)
1.1 cgd 734: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 735: in_hosteq(ip->ip_src, fp->ipq_src) &&
736: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 737: ip->ip_p == fp->ipq_p)
738: goto found;
739: fp = 0;
740: found:
741:
742: /*
743: * Adjust ip_len to not reflect header,
1.25 cgd 744: * set ipqe_mff if more fragments are expected,
1.1 cgd 745: * convert offset of this to bytes.
746: */
1.155 itojun 747: ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
748: mff = (ip->ip_off & htons(IP_MF)) != 0;
1.25 cgd 749: if (mff) {
1.16 cgd 750: /*
751: * Make sure that fragments have a data length
752: * that's a non-zero multiple of 8 bytes.
753: */
1.155 itojun 754: if (ntohs(ip->ip_len) == 0 ||
755: (ntohs(ip->ip_len) & 0x7) != 0) {
1.16 cgd 756: ipstat.ips_badfrags++;
1.75 thorpej 757: IPQ_UNLOCK();
1.16 cgd 758: goto bad;
759: }
760: }
1.155 itojun 761: ip->ip_off = htons((ntohs(ip->ip_off) & IP_OFFMASK) << 3);
1.1 cgd 762:
763: /*
764: * If datagram marked as having more fragments
765: * or if this is not the first fragment,
766: * attempt reassembly; if it succeeds, proceed.
767: */
1.155 itojun 768: if (mff || ip->ip_off != htons(0)) {
1.1 cgd 769: ipstat.ips_fragments++;
1.72 thorpej 770: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 771: if (ipqe == NULL) {
772: ipstat.ips_rcvmemdrop++;
1.75 thorpej 773: IPQ_UNLOCK();
1.25 cgd 774: goto bad;
775: }
776: ipqe->ipqe_mff = mff;
1.50 thorpej 777: ipqe->ipqe_m = m;
1.25 cgd 778: ipqe->ipqe_ip = ip;
1.50 thorpej 779: m = ip_reass(ipqe, fp);
1.75 thorpej 780: if (m == 0) {
781: IPQ_UNLOCK();
1.89 itojun 782: return;
1.75 thorpej 783: }
1.13 mycroft 784: ipstat.ips_reassembled++;
1.50 thorpej 785: ip = mtod(m, struct ip *);
1.74 thorpej 786: hlen = ip->ip_hl << 2;
1.155 itojun 787: ip->ip_len = htons(ntohs(ip->ip_len) + hlen);
1.1 cgd 788: } else
789: if (fp)
790: ip_freef(fp);
1.75 thorpej 791: IPQ_UNLOCK();
1.79 mycroft 792: }
1.128 itojun 793:
794: #ifdef IPSEC
795: /*
796: * enforce IPsec policy checking if we are seeing last header.
797: * note that we do not visit this with protocols with pcb layer
798: * code - like udp/tcp/raw ip.
799: */
800: if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
801: ipsec4_in_reject(m, NULL)) {
802: ipsecstat.in_polvio++;
803: goto bad;
804: }
805: #endif
1.1 cgd 806:
807: /*
808: * Switch out to protocol's input routine.
809: */
1.82 aidan 810: #if IFA_STATS
1.122 itojun 811: if (ia && ip)
1.155 itojun 812: ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
1.82 aidan 813: #endif
1.1 cgd 814: ipstat.ips_delivered++;
1.89 itojun 815: {
816: int off = hlen, nh = ip->ip_p;
817:
818: (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
819: return;
820: }
1.1 cgd 821: bad:
822: m_freem(m);
1.135 thorpej 823: return;
824:
825: badcsum:
826: ipstat.ips_badsum++;
827: m_freem(m);
1.1 cgd 828: }
829:
830: /*
831: * Take incoming datagram fragment and try to
832: * reassemble it into whole datagram. If a chain for
833: * reassembly of this datagram already exists, then it
834: * is given as fp; otherwise have to make a chain.
835: */
1.50 thorpej 836: struct mbuf *
1.25 cgd 837: ip_reass(ipqe, fp)
1.109 augustss 838: struct ipqent *ipqe;
839: struct ipq *fp;
1.1 cgd 840: {
1.109 augustss 841: struct mbuf *m = ipqe->ipqe_m;
842: struct ipqent *nq, *p, *q;
1.25 cgd 843: struct ip *ip;
1.1 cgd 844: struct mbuf *t;
1.25 cgd 845: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 846: int i, next;
847:
1.75 thorpej 848: IPQ_LOCK_CHECK();
849:
1.1 cgd 850: /*
851: * Presence of header sizes in mbufs
852: * would confuse code below.
853: */
854: m->m_data += hlen;
855: m->m_len -= hlen;
856:
857: /*
858: * If first fragment to arrive, create a reassembly queue.
859: */
860: if (fp == 0) {
1.131 itojun 861: /*
862: * Enforce upper bound on number of fragmented packets
863: * for which we attempt reassembly;
864: * If maxfrag is 0, never accept fragments.
865: * If maxfrag is -1, accept all fragments without limitation.
866: */
867: if (ip_maxfragpackets < 0)
868: ;
869: else if (ip_nfragpackets >= ip_maxfragpackets)
870: goto dropfrag;
871: ip_nfragpackets++;
1.50 thorpej 872: MALLOC(fp, struct ipq *, sizeof (struct ipq),
873: M_FTABLE, M_NOWAIT);
874: if (fp == NULL)
1.1 cgd 875: goto dropfrag;
1.25 cgd 876: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 877: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 878: fp->ipq_p = ipqe->ipqe_ip->ip_p;
879: fp->ipq_id = ipqe->ipqe_ip->ip_id;
1.148 matt 880: TAILQ_INIT(&fp->ipq_fragq);
1.25 cgd 881: fp->ipq_src = ipqe->ipqe_ip->ip_src;
882: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
883: p = NULL;
1.1 cgd 884: goto insert;
885: }
886:
887: /*
888: * Find a segment which begins after this one does.
889: */
1.148 matt 890: for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
891: p = q, q = TAILQ_NEXT(q, ipqe_q))
1.155 itojun 892: if (ntohs(q->ipqe_ip->ip_off) > ntohs(ipqe->ipqe_ip->ip_off))
1.1 cgd 893: break;
894:
895: /*
896: * If there is a preceding segment, it may provide some of
897: * our data already. If so, drop the data from the incoming
898: * segment. If it provides all of our data, drop us.
899: */
1.25 cgd 900: if (p != NULL) {
1.155 itojun 901: i = ntohs(p->ipqe_ip->ip_off) + ntohs(p->ipqe_ip->ip_len) -
902: ntohs(ipqe->ipqe_ip->ip_off);
1.1 cgd 903: if (i > 0) {
1.155 itojun 904: if (i >= ntohs(ipqe->ipqe_ip->ip_len))
1.1 cgd 905: goto dropfrag;
1.50 thorpej 906: m_adj(ipqe->ipqe_m, i);
1.155 itojun 907: ipqe->ipqe_ip->ip_off =
908: htons(ntohs(ipqe->ipqe_ip->ip_off) + i);
909: ipqe->ipqe_ip->ip_len =
910: htons(ntohs(ipqe->ipqe_ip->ip_len) - i);
1.1 cgd 911: }
912: }
913:
914: /*
915: * While we overlap succeeding segments trim them or,
916: * if they are completely covered, dequeue them.
917: */
1.155 itojun 918: for (; q != NULL &&
919: ntohs(ipqe->ipqe_ip->ip_off) + ntohs(ipqe->ipqe_ip->ip_len) >
920: ntohs(q->ipqe_ip->ip_off); q = nq) {
921: i = (ntohs(ipqe->ipqe_ip->ip_off) +
922: ntohs(ipqe->ipqe_ip->ip_len)) - ntohs(q->ipqe_ip->ip_off);
923: if (i < ntohs(q->ipqe_ip->ip_len)) {
924: q->ipqe_ip->ip_len =
925: htons(ntohs(q->ipqe_ip->ip_len) - i);
926: q->ipqe_ip->ip_off =
927: htons(ntohs(q->ipqe_ip->ip_off) + i);
1.50 thorpej 928: m_adj(q->ipqe_m, i);
1.1 cgd 929: break;
930: }
1.148 matt 931: nq = TAILQ_NEXT(q, ipqe_q);
1.50 thorpej 932: m_freem(q->ipqe_m);
1.148 matt 933: TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72 thorpej 934: pool_put(&ipqent_pool, q);
1.1 cgd 935: }
936:
937: insert:
938: /*
939: * Stick new segment in its place;
940: * check for complete reassembly.
941: */
1.25 cgd 942: if (p == NULL) {
1.148 matt 943: TAILQ_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
1.25 cgd 944: } else {
1.148 matt 945: TAILQ_INSERT_AFTER(&fp->ipq_fragq, p, ipqe, ipqe_q);
1.25 cgd 946: }
1.1 cgd 947: next = 0;
1.148 matt 948: for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
949: p = q, q = TAILQ_NEXT(q, ipqe_q)) {
1.155 itojun 950: if (ntohs(q->ipqe_ip->ip_off) != next)
1.1 cgd 951: return (0);
1.155 itojun 952: next += ntohs(q->ipqe_ip->ip_len);
1.1 cgd 953: }
1.25 cgd 954: if (p->ipqe_mff)
1.1 cgd 955: return (0);
956:
957: /*
1.41 thorpej 958: * Reassembly is complete. Check for a bogus message size and
959: * concatenate fragments.
1.1 cgd 960: */
1.148 matt 961: q = TAILQ_FIRST(&fp->ipq_fragq);
1.25 cgd 962: ip = q->ipqe_ip;
1.41 thorpej 963: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
964: ipstat.ips_toolong++;
965: ip_freef(fp);
966: return (0);
967: }
1.50 thorpej 968: m = q->ipqe_m;
1.1 cgd 969: t = m->m_next;
970: m->m_next = 0;
971: m_cat(m, t);
1.148 matt 972: nq = TAILQ_NEXT(q, ipqe_q);
1.72 thorpej 973: pool_put(&ipqent_pool, q);
1.25 cgd 974: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 975: t = q->ipqe_m;
1.148 matt 976: nq = TAILQ_NEXT(q, ipqe_q);
1.72 thorpej 977: pool_put(&ipqent_pool, q);
1.1 cgd 978: m_cat(m, t);
979: }
980:
981: /*
982: * Create header for new ip packet by
983: * modifying header of first packet;
984: * dequeue and discard fragment reassembly header.
985: * Make header visible.
986: */
1.155 itojun 987: ip->ip_len = htons(next);
1.25 cgd 988: ip->ip_src = fp->ipq_src;
989: ip->ip_dst = fp->ipq_dst;
990: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 991: FREE(fp, M_FTABLE);
1.131 itojun 992: ip_nfragpackets--;
1.1 cgd 993: m->m_len += (ip->ip_hl << 2);
994: m->m_data -= (ip->ip_hl << 2);
995: /* some debugging cruft by sklower, below, will go away soon */
996: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1.109 augustss 997: int plen = 0;
1.50 thorpej 998: for (t = m; t; t = t->m_next)
999: plen += t->m_len;
1000: m->m_pkthdr.len = plen;
1.1 cgd 1001: }
1.50 thorpej 1002: return (m);
1.1 cgd 1003:
1004: dropfrag:
1005: ipstat.ips_fragdropped++;
1006: m_freem(m);
1.72 thorpej 1007: pool_put(&ipqent_pool, ipqe);
1.1 cgd 1008: return (0);
1009: }
1010:
1011: /*
1012: * Free a fragment reassembly header and all
1013: * associated datagrams.
1014: */
1.8 mycroft 1015: void
1.1 cgd 1016: ip_freef(fp)
1017: struct ipq *fp;
1018: {
1.109 augustss 1019: struct ipqent *q, *p;
1.1 cgd 1020:
1.75 thorpej 1021: IPQ_LOCK_CHECK();
1022:
1.148 matt 1023: for (q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL; q = p) {
1024: p = TAILQ_NEXT(q, ipqe_q);
1.50 thorpej 1025: m_freem(q->ipqe_m);
1.148 matt 1026: TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72 thorpej 1027: pool_put(&ipqent_pool, q);
1.1 cgd 1028: }
1.25 cgd 1029: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 1030: FREE(fp, M_FTABLE);
1.131 itojun 1031: ip_nfragpackets--;
1.1 cgd 1032: }
1033:
1034: /*
1035: * IP timer processing;
1036: * if a timer expires on a reassembly
1037: * queue, discard it.
1038: */
1.8 mycroft 1039: void
1.1 cgd 1040: ip_slowtimo()
1041: {
1.109 augustss 1042: struct ipq *fp, *nfp;
1.24 mycroft 1043: int s = splsoftnet();
1.1 cgd 1044:
1.75 thorpej 1045: IPQ_LOCK();
1.140 matt 1046: for (fp = LIST_FIRST(&ipq); fp != NULL; fp = nfp) {
1047: nfp = LIST_NEXT(fp, ipq_q);
1.25 cgd 1048: if (--fp->ipq_ttl == 0) {
1.1 cgd 1049: ipstat.ips_fragtimeout++;
1.25 cgd 1050: ip_freef(fp);
1.1 cgd 1051: }
1052: }
1.131 itojun 1053: /*
1054: * If we are over the maximum number of fragments
1055: * (due to the limit being lowered), drain off
1056: * enough to get down to the new limit.
1057: */
1058: if (ip_maxfragpackets < 0)
1059: ;
1060: else {
1.140 matt 1061: while (ip_nfragpackets > ip_maxfragpackets && LIST_FIRST(&ipq))
1062: ip_freef(LIST_FIRST(&ipq));
1.131 itojun 1063: }
1.75 thorpej 1064: IPQ_UNLOCK();
1.63 matt 1065: #ifdef GATEWAY
1066: ipflow_slowtimo();
1067: #endif
1.1 cgd 1068: splx(s);
1069: }
1070:
1071: /*
1072: * Drain off all datagram fragments.
1073: */
1.8 mycroft 1074: void
1.1 cgd 1075: ip_drain()
1076: {
1077:
1.75 thorpej 1078: /*
1079: * We may be called from a device's interrupt context. If
1080: * the ipq is already busy, just bail out now.
1081: */
1082: if (ipq_lock_try() == 0)
1083: return;
1084:
1.140 matt 1085: while (LIST_FIRST(&ipq) != NULL) {
1.1 cgd 1086: ipstat.ips_fragdropped++;
1.140 matt 1087: ip_freef(LIST_FIRST(&ipq));
1.1 cgd 1088: }
1.75 thorpej 1089:
1090: IPQ_UNLOCK();
1.1 cgd 1091: }
1092:
1093: /*
1094: * Do option processing on a datagram,
1095: * possibly discarding it if bad options are encountered,
1096: * or forwarding it if source-routed.
1097: * Returns 1 if packet has been forwarded/freed,
1098: * 0 if the packet should be processed further.
1099: */
1.8 mycroft 1100: int
1.1 cgd 1101: ip_dooptions(m)
1102: struct mbuf *m;
1103: {
1.109 augustss 1104: struct ip *ip = mtod(m, struct ip *);
1105: u_char *cp, *cp0;
1106: struct ip_timestamp *ipt;
1107: struct in_ifaddr *ia;
1.1 cgd 1108: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.104 thorpej 1109: struct in_addr dst;
1.1 cgd 1110: n_time ntime;
1111:
1.13 mycroft 1112: dst = ip->ip_dst;
1.1 cgd 1113: cp = (u_char *)(ip + 1);
1114: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
1115: for (; cnt > 0; cnt -= optlen, cp += optlen) {
1116: opt = cp[IPOPT_OPTVAL];
1117: if (opt == IPOPT_EOL)
1118: break;
1119: if (opt == IPOPT_NOP)
1120: optlen = 1;
1121: else {
1.113 itojun 1122: if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1123: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1124: goto bad;
1125: }
1.1 cgd 1126: optlen = cp[IPOPT_OLEN];
1.114 itojun 1127: if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1.1 cgd 1128: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1129: goto bad;
1130: }
1131: }
1132: switch (opt) {
1133:
1134: default:
1135: break;
1136:
1137: /*
1138: * Source routing with record.
1139: * Find interface with current destination address.
1140: * If none on this machine then drop if strictly routed,
1141: * or do nothing if loosely routed.
1142: * Record interface address and bring up next address
1143: * component. If strictly routed make sure next
1144: * address is on directly accessible net.
1145: */
1146: case IPOPT_LSRR:
1147: case IPOPT_SSRR:
1.47 cjs 1148: if (ip_allowsrcrt == 0) {
1149: type = ICMP_UNREACH;
1150: code = ICMP_UNREACH_NET_PROHIB;
1151: goto bad;
1152: }
1.114 itojun 1153: if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1154: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1155: goto bad;
1156: }
1.1 cgd 1157: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1158: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1159: goto bad;
1160: }
1161: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 1162: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 1163: if (ia == 0) {
1164: if (opt == IPOPT_SSRR) {
1165: type = ICMP_UNREACH;
1166: code = ICMP_UNREACH_SRCFAIL;
1167: goto bad;
1168: }
1169: /*
1170: * Loose routing, and not at next destination
1171: * yet; nothing to do except forward.
1172: */
1173: break;
1174: }
1175: off--; /* 0 origin */
1.112 sommerfe 1176: if ((off + sizeof(struct in_addr)) > optlen) {
1.1 cgd 1177: /*
1178: * End of source route. Should be for us.
1179: */
1180: save_rte(cp, ip->ip_src);
1181: break;
1182: }
1183: /*
1184: * locate outgoing interface
1185: */
1186: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
1187: sizeof(ipaddr.sin_addr));
1.96 thorpej 1188: if (opt == IPOPT_SSRR)
1189: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1190: else
1.1 cgd 1191: ia = ip_rtaddr(ipaddr.sin_addr);
1192: if (ia == 0) {
1193: type = ICMP_UNREACH;
1194: code = ICMP_UNREACH_SRCFAIL;
1195: goto bad;
1196: }
1197: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 1198: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1199: (caddr_t)(cp + off), sizeof(struct in_addr));
1200: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 1201: /*
1202: * Let ip_intr's mcast routing check handle mcast pkts
1203: */
1.18 mycroft 1204: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 1205: break;
1206:
1207: case IPOPT_RR:
1.114 itojun 1208: if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1209: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1210: goto bad;
1211: }
1.1 cgd 1212: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1213: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1214: goto bad;
1215: }
1216: /*
1217: * If no space remains, ignore.
1218: */
1219: off--; /* 0 origin */
1.112 sommerfe 1220: if ((off + sizeof(struct in_addr)) > optlen)
1.1 cgd 1221: break;
1222: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
1223: sizeof(ipaddr.sin_addr));
1224: /*
1225: * locate outgoing interface; if we're the destination,
1226: * use the incoming interface (should be same).
1227: */
1.96 thorpej 1228: if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
1229: == NULL &&
1230: (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1.1 cgd 1231: type = ICMP_UNREACH;
1232: code = ICMP_UNREACH_HOST;
1233: goto bad;
1234: }
1.20 mycroft 1235: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1236: (caddr_t)(cp + off), sizeof(struct in_addr));
1237: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1238: break;
1239:
1240: case IPOPT_TS:
1241: code = cp - (u_char *)ip;
1242: ipt = (struct ip_timestamp *)cp;
1.114 itojun 1243: if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1244: code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1.1 cgd 1245: goto bad;
1.114 itojun 1246: }
1247: if (ipt->ipt_ptr < 5) {
1248: code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1249: goto bad;
1250: }
1.15 cgd 1251: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.114 itojun 1252: if (++ipt->ipt_oflw == 0) {
1253: code = (u_char *)&ipt->ipt_ptr -
1254: (u_char *)ip;
1.1 cgd 1255: goto bad;
1.114 itojun 1256: }
1.1 cgd 1257: break;
1258: }
1.104 thorpej 1259: cp0 = (cp + ipt->ipt_ptr - 1);
1.1 cgd 1260: switch (ipt->ipt_flg) {
1261:
1262: case IPOPT_TS_TSONLY:
1263: break;
1264:
1265: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1266: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114 itojun 1267: sizeof(struct in_addr) > ipt->ipt_len) {
1268: code = (u_char *)&ipt->ipt_ptr -
1269: (u_char *)ip;
1.1 cgd 1270: goto bad;
1.114 itojun 1271: }
1.13 mycroft 1272: ipaddr.sin_addr = dst;
1.96 thorpej 1273: ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
1274: m->m_pkthdr.rcvif));
1.13 mycroft 1275: if (ia == 0)
1276: continue;
1.104 thorpej 1277: bcopy(&ia->ia_addr.sin_addr,
1278: cp0, sizeof(struct in_addr));
1.1 cgd 1279: ipt->ipt_ptr += sizeof(struct in_addr);
1280: break;
1281:
1282: case IPOPT_TS_PRESPEC:
1.66 thorpej 1283: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114 itojun 1284: sizeof(struct in_addr) > ipt->ipt_len) {
1285: code = (u_char *)&ipt->ipt_ptr -
1286: (u_char *)ip;
1.1 cgd 1287: goto bad;
1.114 itojun 1288: }
1.104 thorpej 1289: bcopy(cp0, &ipaddr.sin_addr,
1.1 cgd 1290: sizeof(struct in_addr));
1.96 thorpej 1291: if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
1292: == NULL)
1.1 cgd 1293: continue;
1294: ipt->ipt_ptr += sizeof(struct in_addr);
1295: break;
1296:
1297: default:
1.114 itojun 1298: /* XXX can't take &ipt->ipt_flg */
1299: code = (u_char *)&ipt->ipt_ptr -
1300: (u_char *)ip + 1;
1.1 cgd 1301: goto bad;
1302: }
1303: ntime = iptime();
1.107 thorpej 1304: cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1305: bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1,
1.1 cgd 1306: sizeof(n_time));
1307: ipt->ipt_ptr += sizeof(n_time);
1308: }
1309: }
1310: if (forward) {
1.26 thorpej 1311: if (ip_forwsrcrt == 0) {
1312: type = ICMP_UNREACH;
1313: code = ICMP_UNREACH_SRCFAIL;
1314: goto bad;
1315: }
1.1 cgd 1316: ip_forward(m, 1);
1317: return (1);
1.13 mycroft 1318: }
1319: return (0);
1.1 cgd 1320: bad:
1.13 mycroft 1321: icmp_error(m, type, code, 0, 0);
1322: ipstat.ips_badoptions++;
1.1 cgd 1323: return (1);
1324: }
1325:
1326: /*
1327: * Given address of next destination (final or next hop),
1328: * return internet address info of interface to be used to get there.
1329: */
1330: struct in_ifaddr *
1331: ip_rtaddr(dst)
1332: struct in_addr dst;
1333: {
1.109 augustss 1334: struct sockaddr_in *sin;
1.1 cgd 1335:
1.19 mycroft 1336: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1337:
1.35 mycroft 1338: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1339: if (ipforward_rt.ro_rt) {
1340: RTFREE(ipforward_rt.ro_rt);
1341: ipforward_rt.ro_rt = 0;
1342: }
1343: sin->sin_family = AF_INET;
1344: sin->sin_len = sizeof(*sin);
1345: sin->sin_addr = dst;
1346:
1347: rtalloc(&ipforward_rt);
1348: }
1349: if (ipforward_rt.ro_rt == 0)
1350: return ((struct in_ifaddr *)0);
1.19 mycroft 1351: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1352: }
1353:
1354: /*
1355: * Save incoming source route for use in replies,
1356: * to be picked up later by ip_srcroute if the receiver is interested.
1357: */
1.13 mycroft 1358: void
1.1 cgd 1359: save_rte(option, dst)
1360: u_char *option;
1361: struct in_addr dst;
1362: {
1363: unsigned olen;
1364:
1365: olen = option[IPOPT_OLEN];
1366: #ifdef DIAGNOSTIC
1367: if (ipprintfs)
1.39 christos 1368: printf("save_rte: olen %d\n", olen);
1.89 itojun 1369: #endif /* 0 */
1.1 cgd 1370: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1371: return;
1372: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1373: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1374: ip_srcrt.dst = dst;
1375: }
1376:
1377: /*
1378: * Retrieve incoming source route for use in replies,
1379: * in the same form used by setsockopt.
1380: * The first hop is placed before the options, will be removed later.
1381: */
1382: struct mbuf *
1383: ip_srcroute()
1384: {
1.109 augustss 1385: struct in_addr *p, *q;
1386: struct mbuf *m;
1.1 cgd 1387:
1388: if (ip_nhops == 0)
1389: return ((struct mbuf *)0);
1390: m = m_get(M_DONTWAIT, MT_SOOPTS);
1391: if (m == 0)
1392: return ((struct mbuf *)0);
1393:
1.13 mycroft 1394: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1395:
1396: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1397: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1398: OPTSIZ;
1399: #ifdef DIAGNOSTIC
1400: if (ipprintfs)
1.39 christos 1401: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1402: #endif
1403:
1404: /*
1405: * First save first hop for return route
1406: */
1407: p = &ip_srcrt.route[ip_nhops - 1];
1408: *(mtod(m, struct in_addr *)) = *p--;
1409: #ifdef DIAGNOSTIC
1410: if (ipprintfs)
1.39 christos 1411: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1412: #endif
1413:
1414: /*
1415: * Copy option fields and padding (nop) to mbuf.
1416: */
1417: ip_srcrt.nop = IPOPT_NOP;
1418: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1419: bcopy((caddr_t)&ip_srcrt.nop,
1420: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1421: q = (struct in_addr *)(mtod(m, caddr_t) +
1422: sizeof(struct in_addr) + OPTSIZ);
1423: #undef OPTSIZ
1424: /*
1425: * Record return path as an IP source route,
1426: * reversing the path (pointers are now aligned).
1427: */
1428: while (p >= ip_srcrt.route) {
1429: #ifdef DIAGNOSTIC
1430: if (ipprintfs)
1.39 christos 1431: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1432: #endif
1433: *q++ = *p--;
1434: }
1435: /*
1436: * Last hop goes to final destination.
1437: */
1438: *q = ip_srcrt.dst;
1439: #ifdef DIAGNOSTIC
1440: if (ipprintfs)
1.39 christos 1441: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1442: #endif
1443: return (m);
1444: }
1445:
1446: /*
1447: * Strip out IP options, at higher
1448: * level protocol in the kernel.
1449: * Second argument is buffer to which options
1450: * will be moved, and return value is their length.
1451: * XXX should be deleted; last arg currently ignored.
1452: */
1.8 mycroft 1453: void
1.1 cgd 1454: ip_stripoptions(m, mopt)
1.109 augustss 1455: struct mbuf *m;
1.1 cgd 1456: struct mbuf *mopt;
1457: {
1.109 augustss 1458: int i;
1.1 cgd 1459: struct ip *ip = mtod(m, struct ip *);
1.109 augustss 1460: caddr_t opts;
1.1 cgd 1461: int olen;
1462:
1.79 mycroft 1463: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1464: opts = (caddr_t)(ip + 1);
1465: i = m->m_len - (sizeof (struct ip) + olen);
1466: bcopy(opts + olen, opts, (unsigned)i);
1467: m->m_len -= olen;
1468: if (m->m_flags & M_PKTHDR)
1469: m->m_pkthdr.len -= olen;
1.155 itojun 1470: ip->ip_len = htons(ntohs(ip->ip_len) - olen);
1.79 mycroft 1471: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1472: }
1473:
1.139 matt 1474: const int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1475: 0, 0, 0, 0,
1476: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1477: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1478: EMSGSIZE, EHOSTUNREACH, 0, 0,
1479: 0, 0, 0, 0,
1480: ENOPROTOOPT
1481: };
1482:
1483: /*
1484: * Forward a packet. If some error occurs return the sender
1485: * an icmp packet. Note we can't always generate a meaningful
1486: * icmp message because icmp doesn't have a large enough repertoire
1487: * of codes and types.
1488: *
1489: * If not forwarding, just drop the packet. This could be confusing
1490: * if ipforwarding was zero but some routing protocol was advancing
1491: * us as a gateway to somewhere. However, we must let the routing
1492: * protocol deal with that.
1493: *
1494: * The srcrt parameter indicates whether the packet is being forwarded
1495: * via a source route.
1496: */
1.13 mycroft 1497: void
1.1 cgd 1498: ip_forward(m, srcrt)
1499: struct mbuf *m;
1500: int srcrt;
1501: {
1.109 augustss 1502: struct ip *ip = mtod(m, struct ip *);
1503: struct sockaddr_in *sin;
1504: struct rtentry *rt;
1.28 christos 1505: int error, type = 0, code = 0;
1.1 cgd 1506: struct mbuf *mcopy;
1.13 mycroft 1507: n_long dest;
1508: struct ifnet *destifp;
1.89 itojun 1509: #ifdef IPSEC
1510: struct ifnet dummyifp;
1511: #endif
1.135 thorpej 1512:
1513: /*
1514: * Clear any in-bound checksum flags for this packet.
1515: */
1516: m->m_pkthdr.csum_flags = 0;
1.1 cgd 1517:
1.13 mycroft 1518: dest = 0;
1.1 cgd 1519: #ifdef DIAGNOSTIC
1520: if (ipprintfs)
1.70 thorpej 1521: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1522: ntohl(ip->ip_src.s_addr),
1523: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1524: #endif
1.93 sommerfe 1525: if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1.1 cgd 1526: ipstat.ips_cantforward++;
1527: m_freem(m);
1528: return;
1529: }
1530: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1531: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1532: return;
1533: }
1534: ip->ip_ttl -= IPTTLDEC;
1535:
1.19 mycroft 1536: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1537: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1538: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1539: if (ipforward_rt.ro_rt) {
1540: RTFREE(ipforward_rt.ro_rt);
1541: ipforward_rt.ro_rt = 0;
1542: }
1543: sin->sin_family = AF_INET;
1.35 mycroft 1544: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1545: sin->sin_addr = ip->ip_dst;
1546:
1547: rtalloc(&ipforward_rt);
1548: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1549: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1550: return;
1551: }
1552: rt = ipforward_rt.ro_rt;
1553: }
1554:
1555: /*
1.34 mycroft 1556: * Save at most 68 bytes of the packet in case
1.1 cgd 1557: * we need to generate an ICMP message to the src.
1.119 itojun 1558: * Pullup to avoid sharing mbuf cluster between m and mcopy.
1.1 cgd 1559: */
1.155 itojun 1560: mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1.119 itojun 1561: if (mcopy)
1562: mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1.1 cgd 1563:
1564: /*
1565: * If forwarding packet using same interface that it came in on,
1566: * perhaps should send a redirect to sender to shortcut a hop.
1567: * Only send redirect if source is sending directly to us,
1568: * and if packet was not source routed (or has any options).
1569: * Also, don't send redirect if forwarding using a default route
1570: * or a route modified by a redirect.
1571: */
1572: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1573: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1574: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1575: ipsendredirects && !srcrt) {
1.19 mycroft 1576: if (rt->rt_ifa &&
1577: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1578: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1579: if (rt->rt_flags & RTF_GATEWAY)
1580: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1581: else
1582: dest = ip->ip_dst.s_addr;
1583: /*
1584: * Router requirements says to only send host
1585: * redirects.
1586: */
1587: type = ICMP_REDIRECT;
1588: code = ICMP_REDIRECT_HOST;
1.1 cgd 1589: #ifdef DIAGNOSTIC
1.77 thorpej 1590: if (ipprintfs)
1591: printf("redirect (%d) to %x\n", code,
1592: (u_int32_t)dest);
1.1 cgd 1593: #endif
1594: }
1595: }
1596:
1.89 itojun 1597: #ifdef IPSEC
1.134 lukem 1598: /* Don't lookup socket in forwarding case */
1.127 itojun 1599: (void)ipsec_setsocket(m, NULL);
1.103 itojun 1600: #endif
1.27 thorpej 1601: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1602: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1603: if (error)
1604: ipstat.ips_cantforward++;
1605: else {
1606: ipstat.ips_forward++;
1607: if (type)
1608: ipstat.ips_redirectsent++;
1609: else {
1.63 matt 1610: if (mcopy) {
1611: #ifdef GATEWAY
1.64 thorpej 1612: if (mcopy->m_flags & M_CANFASTFWD)
1613: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1614: #endif
1.1 cgd 1615: m_freem(mcopy);
1.63 matt 1616: }
1.1 cgd 1617: return;
1618: }
1619: }
1620: if (mcopy == NULL)
1621: return;
1.13 mycroft 1622: destifp = NULL;
1623:
1.1 cgd 1624: switch (error) {
1625:
1626: case 0: /* forwarded, but need redirect */
1627: /* type, code set above */
1628: break;
1629:
1630: case ENETUNREACH: /* shouldn't happen, checked above */
1631: case EHOSTUNREACH:
1632: case ENETDOWN:
1633: case EHOSTDOWN:
1634: default:
1635: type = ICMP_UNREACH;
1636: code = ICMP_UNREACH_HOST;
1637: break;
1638:
1639: case EMSGSIZE:
1640: type = ICMP_UNREACH;
1641: code = ICMP_UNREACH_NEEDFRAG;
1.89 itojun 1642: #ifndef IPSEC
1.13 mycroft 1643: if (ipforward_rt.ro_rt)
1644: destifp = ipforward_rt.ro_rt->rt_ifp;
1.89 itojun 1645: #else
1646: /*
1647: * If the packet is routed over IPsec tunnel, tell the
1648: * originator the tunnel MTU.
1649: * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1650: * XXX quickhack!!!
1651: */
1652: if (ipforward_rt.ro_rt) {
1653: struct secpolicy *sp;
1654: int ipsecerror;
1.95 itojun 1655: size_t ipsechdr;
1.89 itojun 1656: struct route *ro;
1657:
1658: sp = ipsec4_getpolicybyaddr(mcopy,
1.95 itojun 1659: IPSEC_DIR_OUTBOUND,
1660: IP_FORWARDING,
1661: &ipsecerror);
1.89 itojun 1662:
1663: if (sp == NULL)
1664: destifp = ipforward_rt.ro_rt->rt_ifp;
1665: else {
1666: /* count IPsec header size */
1.95 itojun 1667: ipsechdr = ipsec4_hdrsiz(mcopy,
1668: IPSEC_DIR_OUTBOUND,
1669: NULL);
1.89 itojun 1670:
1671: /*
1672: * find the correct route for outer IPv4
1673: * header, compute tunnel MTU.
1674: *
1675: * XXX BUG ALERT
1676: * The "dummyifp" code relies upon the fact
1677: * that icmp_error() touches only ifp->if_mtu.
1678: */
1679: /*XXX*/
1680: destifp = NULL;
1681: if (sp->req != NULL
1.95 itojun 1682: && sp->req->sav != NULL
1683: && sp->req->sav->sah != NULL) {
1684: ro = &sp->req->sav->sah->sa_route;
1.89 itojun 1685: if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1686: dummyifp.if_mtu =
1.151 itojun 1687: ro->ro_rt->rt_rmx.rmx_mtu ?
1688: ro->ro_rt->rt_rmx.rmx_mtu :
1.89 itojun 1689: ro->ro_rt->rt_ifp->if_mtu;
1690: dummyifp.if_mtu -= ipsechdr;
1691: destifp = &dummyifp;
1692: }
1693: }
1694:
1695: key_freesp(sp);
1696: }
1697: }
1698: #endif /*IPSEC*/
1.1 cgd 1699: ipstat.ips_cantfrag++;
1700: break;
1701:
1702: case ENOBUFS:
1.143 itojun 1703: #if 1
1704: /*
1705: * a router should not generate ICMP_SOURCEQUENCH as
1706: * required in RFC1812 Requirements for IP Version 4 Routers.
1707: * source quench could be a big problem under DoS attacks,
1.149 wiz 1708: * or if the underlying interface is rate-limited.
1.143 itojun 1709: */
1710: if (mcopy)
1711: m_freem(mcopy);
1712: return;
1713: #else
1.1 cgd 1714: type = ICMP_SOURCEQUENCH;
1715: code = 0;
1716: break;
1.143 itojun 1717: #endif
1.1 cgd 1718: }
1.13 mycroft 1719: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1720: }
1721:
1722: void
1723: ip_savecontrol(inp, mp, ip, m)
1.109 augustss 1724: struct inpcb *inp;
1725: struct mbuf **mp;
1726: struct ip *ip;
1727: struct mbuf *m;
1.44 thorpej 1728: {
1729:
1730: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1731: struct timeval tv;
1732:
1733: microtime(&tv);
1734: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1735: SCM_TIMESTAMP, SOL_SOCKET);
1736: if (*mp)
1737: mp = &(*mp)->m_next;
1738: }
1739: if (inp->inp_flags & INP_RECVDSTADDR) {
1740: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1741: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1742: if (*mp)
1743: mp = &(*mp)->m_next;
1744: }
1745: #ifdef notyet
1746: /*
1747: * XXX
1748: * Moving these out of udp_input() made them even more broken
1749: * than they already were.
1750: * - fenner@parc.xerox.com
1751: */
1752: /* options were tossed already */
1753: if (inp->inp_flags & INP_RECVOPTS) {
1754: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1755: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1756: if (*mp)
1757: mp = &(*mp)->m_next;
1758: }
1759: /* ip_srcroute doesn't do what we want here, need to fix */
1760: if (inp->inp_flags & INP_RECVRETOPTS) {
1761: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1762: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1763: if (*mp)
1764: mp = &(*mp)->m_next;
1765: }
1766: #endif
1767: if (inp->inp_flags & INP_RECVIF) {
1768: struct sockaddr_dl sdl;
1769:
1770: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1771: sdl.sdl_family = AF_LINK;
1772: sdl.sdl_index = m->m_pkthdr.rcvif ?
1773: m->m_pkthdr.rcvif->if_index : 0;
1774: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1775: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1776: IP_RECVIF, IPPROTO_IP);
1777: if (*mp)
1778: mp = &(*mp)->m_next;
1779: }
1.13 mycroft 1780: }
1781:
1782: int
1783: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1784: int *name;
1785: u_int namelen;
1786: void *oldp;
1787: size_t *oldlenp;
1788: void *newp;
1789: size_t newlen;
1790: {
1.88 sommerfe 1791: extern int subnetsarelocal, hostzeroisbroadcast;
1.52 thorpej 1792:
1.54 lukem 1793: int error, old;
1794:
1.13 mycroft 1795: /* All sysctl names at this level are terminal. */
1796: if (namelen != 1)
1797: return (ENOTDIR);
1798:
1799: switch (name[0]) {
1800: case IPCTL_FORWARDING:
1801: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1802: case IPCTL_SENDREDIRECTS:
1803: return (sysctl_int(oldp, oldlenp, newp, newlen,
1804: &ipsendredirects));
1805: case IPCTL_DEFTTL:
1806: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1807: #ifdef notyet
1808: case IPCTL_DEFMTU:
1809: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1810: #endif
1.26 thorpej 1811: case IPCTL_FORWSRCRT:
1.47 cjs 1812: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1813: if (securelevel > 0)
1.46 cjs 1814: return (sysctl_rdint(oldp, oldlenp, newp,
1815: ip_forwsrcrt));
1816: else
1817: return (sysctl_int(oldp, oldlenp, newp, newlen,
1818: &ip_forwsrcrt));
1.27 thorpej 1819: case IPCTL_DIRECTEDBCAST:
1820: return (sysctl_int(oldp, oldlenp, newp, newlen,
1821: &ip_directedbcast));
1.47 cjs 1822: case IPCTL_ALLOWSRCRT:
1823: return (sysctl_int(oldp, oldlenp, newp, newlen,
1824: &ip_allowsrcrt));
1.52 thorpej 1825: case IPCTL_SUBNETSARELOCAL:
1826: return (sysctl_int(oldp, oldlenp, newp, newlen,
1827: &subnetsarelocal));
1.53 kml 1828: case IPCTL_MTUDISC:
1.60 kml 1829: error = sysctl_int(oldp, oldlenp, newp, newlen,
1830: &ip_mtudisc);
1831: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1.152 itojun 1832: ip_mtudisc_timeout_q =
1.60 kml 1833: rt_timer_queue_create(ip_mtudisc_timeout);
1834: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1835: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1836: ip_mtudisc_timeout_q = NULL;
1837: }
1838: return error;
1.54 lukem 1839: case IPCTL_ANONPORTMIN:
1840: old = anonportmin;
1841: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1.118 itojun 1842: if (anonportmin >= anonportmax || anonportmin < 0
1843: || anonportmin > 65535
1.54 lukem 1844: #ifndef IPNOPRIVPORTS
1845: || anonportmin < IPPORT_RESERVED
1846: #endif
1847: ) {
1848: anonportmin = old;
1849: return (EINVAL);
1850: }
1851: return (error);
1852: case IPCTL_ANONPORTMAX:
1853: old = anonportmax;
1854: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1.118 itojun 1855: if (anonportmin >= anonportmax || anonportmax < 0
1856: || anonportmax > 65535
1.54 lukem 1857: #ifndef IPNOPRIVPORTS
1858: || anonportmax < IPPORT_RESERVED
1859: #endif
1860: ) {
1861: anonportmax = old;
1862: return (EINVAL);
1863: }
1.60 kml 1864: return (error);
1865: case IPCTL_MTUDISCTIMEOUT:
1866: error = sysctl_int(oldp, oldlenp, newp, newlen,
1867: &ip_mtudisc_timeout);
1.156 ! itojun 1868: if (ip_mtudisc_timeout < 0)
! 1869: return (EINVAL);
1.60 kml 1870: if (ip_mtudisc_timeout_q != NULL)
1.152 itojun 1871: rt_timer_queue_change(ip_mtudisc_timeout_q,
1.60 kml 1872: ip_mtudisc_timeout);
1.54 lukem 1873: return (error);
1.65 matt 1874: #ifdef GATEWAY
1875: case IPCTL_MAXFLOWS:
1.67 thorpej 1876: {
1877: int s;
1878:
1.65 matt 1879: error = sysctl_int(oldp, oldlenp, newp, newlen,
1880: &ip_maxflows);
1.67 thorpej 1881: s = splsoftnet();
1.65 matt 1882: ipflow_reap(0);
1.67 thorpej 1883: splx(s);
1.65 matt 1884: return (error);
1.67 thorpej 1885: }
1.89 itojun 1886: #endif
1.90 itojun 1887: case IPCTL_HOSTZEROBROADCAST:
1888: return (sysctl_int(oldp, oldlenp, newp, newlen,
1889: &hostzeroisbroadcast));
1.89 itojun 1890: #if NGIF > 0
1891: case IPCTL_GIF_TTL:
1892: return(sysctl_int(oldp, oldlenp, newp, newlen,
1.90 itojun 1893: &ip_gif_ttl));
1.144 martin 1894: #endif
1895:
1896: #if NGRE > 0
1897: case IPCTL_GRE_TTL:
1898: return(sysctl_int(oldp, oldlenp, newp, newlen,
1899: &ip_gre_ttl));
1.117 tron 1900: #endif
1901:
1902: #ifndef IPNOPRIVPORTS
1903: case IPCTL_LOWPORTMIN:
1904: old = lowportmin;
1905: error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmin);
1906: if (lowportmin >= lowportmax
1907: || lowportmin > IPPORT_RESERVEDMAX
1908: || lowportmin < IPPORT_RESERVEDMIN
1909: ) {
1910: lowportmin = old;
1911: return (EINVAL);
1912: }
1913: return (error);
1914: case IPCTL_LOWPORTMAX:
1915: old = lowportmax;
1916: error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmax);
1917: if (lowportmin >= lowportmax
1918: || lowportmax > IPPORT_RESERVEDMAX
1919: || lowportmax < IPPORT_RESERVEDMIN
1920: ) {
1921: lowportmax = old;
1922: return (EINVAL);
1923: }
1924: return (error);
1.65 matt 1925: #endif
1.131 itojun 1926:
1927: case IPCTL_MAXFRAGPACKETS:
1928: return (sysctl_int(oldp, oldlenp, newp, newlen,
1929: &ip_maxfragpackets));
1.88 sommerfe 1930:
1.13 mycroft 1931: default:
1932: return (EOPNOTSUPP);
1933: }
1934: /* NOTREACHED */
1.1 cgd 1935: }
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