Annotation of src/sys/netinet/ip_input.c, Revision 1.183
1.183 ! jonathan 1: /* $NetBSD: ip_input.c,v 1.182 2003/11/12 15:00:05 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.
1.172 agc 81: * 3. Neither the name of the University nor the names of its contributors
1.1 cgd 82: * may be used to endorse or promote products derived from this software
83: * without specific prior written permission.
84: *
85: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
86: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
87: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
88: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
89: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
90: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
91: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
92: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
93: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
94: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
95: * SUCH DAMAGE.
96: *
1.14 cgd 97: * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
1.1 cgd 98: */
1.141 lukem 99:
100: #include <sys/cdefs.h>
1.183 ! jonathan 101: __KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.182 2003/11/12 15:00:05 itojun Exp $");
1.55 scottr 102:
1.62 matt 103: #include "opt_gateway.h"
1.69 mrg 104: #include "opt_pfil_hooks.h"
1.91 thorpej 105: #include "opt_ipsec.h"
1.55 scottr 106: #include "opt_mrouting.h"
1.167 martin 107: #include "opt_mbuftrace.h"
1.135 thorpej 108: #include "opt_inet_csum.h"
1.1 cgd 109:
1.5 mycroft 110: #include <sys/param.h>
111: #include <sys/systm.h>
112: #include <sys/malloc.h>
113: #include <sys/mbuf.h>
114: #include <sys/domain.h>
115: #include <sys/protosw.h>
116: #include <sys/socket.h>
1.44 thorpej 117: #include <sys/socketvar.h>
1.5 mycroft 118: #include <sys/errno.h>
119: #include <sys/time.h>
120: #include <sys/kernel.h>
1.72 thorpej 121: #include <sys/pool.h>
1.28 christos 122: #include <sys/sysctl.h>
1.1 cgd 123:
1.5 mycroft 124: #include <net/if.h>
1.44 thorpej 125: #include <net/if_dl.h>
1.5 mycroft 126: #include <net/route.h>
1.45 mrg 127: #include <net/pfil.h>
1.1 cgd 128:
1.5 mycroft 129: #include <netinet/in.h>
130: #include <netinet/in_systm.h>
131: #include <netinet/ip.h>
132: #include <netinet/in_pcb.h>
133: #include <netinet/in_var.h>
134: #include <netinet/ip_var.h>
135: #include <netinet/ip_icmp.h>
1.89 itojun 136: /* just for gif_ttl */
137: #include <netinet/in_gif.h>
138: #include "gif.h"
1.144 martin 139: #include <net/if_gre.h>
140: #include "gre.h"
1.111 jdolecek 141:
142: #ifdef MROUTING
143: #include <netinet/ip_mroute.h>
144: #endif
1.89 itojun 145:
146: #ifdef IPSEC
147: #include <netinet6/ipsec.h>
148: #include <netkey/key.h>
149: #endif
1.173 jonathan 150: #ifdef FAST_IPSEC
151: #include <netipsec/ipsec.h>
152: #include <netipsec/key.h>
153: #endif /* FAST_IPSEC*/
1.44 thorpej 154:
1.1 cgd 155: #ifndef IPFORWARDING
156: #ifdef GATEWAY
157: #define IPFORWARDING 1 /* forward IP packets not for us */
158: #else /* GATEWAY */
159: #define IPFORWARDING 0 /* don't forward IP packets not for us */
160: #endif /* GATEWAY */
161: #endif /* IPFORWARDING */
162: #ifndef IPSENDREDIRECTS
163: #define IPSENDREDIRECTS 1
164: #endif
1.26 thorpej 165: #ifndef IPFORWSRCRT
1.47 cjs 166: #define IPFORWSRCRT 1 /* forward source-routed packets */
167: #endif
168: #ifndef IPALLOWSRCRT
1.48 mrg 169: #define IPALLOWSRCRT 1 /* allow source-routed packets */
1.26 thorpej 170: #endif
1.53 kml 171: #ifndef IPMTUDISC
1.153 itojun 172: #define IPMTUDISC 1
1.53 kml 173: #endif
1.60 kml 174: #ifndef IPMTUDISCTIMEOUT
1.61 kml 175: #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
1.60 kml 176: #endif
1.53 kml 177:
1.27 thorpej 178: /*
179: * Note: DIRECTED_BROADCAST is handled this way so that previous
180: * configuration using this option will Just Work.
181: */
182: #ifndef IPDIRECTEDBCAST
183: #ifdef DIRECTED_BROADCAST
184: #define IPDIRECTEDBCAST 1
185: #else
186: #define IPDIRECTEDBCAST 0
187: #endif /* DIRECTED_BROADCAST */
188: #endif /* IPDIRECTEDBCAST */
1.1 cgd 189: int ipforwarding = IPFORWARDING;
190: int ipsendredirects = IPSENDREDIRECTS;
1.13 mycroft 191: int ip_defttl = IPDEFTTL;
1.26 thorpej 192: int ip_forwsrcrt = IPFORWSRCRT;
1.27 thorpej 193: int ip_directedbcast = IPDIRECTEDBCAST;
1.47 cjs 194: int ip_allowsrcrt = IPALLOWSRCRT;
1.53 kml 195: int ip_mtudisc = IPMTUDISC;
1.156 itojun 196: int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1 cgd 197: #ifdef DIAGNOSTIC
198: int ipprintfs = 0;
199: #endif
1.165 christos 200: /*
201: * XXX - Setting ip_checkinterface mostly implements the receive side of
202: * the Strong ES model described in RFC 1122, but since the routing table
203: * and transmit implementation do not implement the Strong ES model,
204: * setting this to 1 results in an odd hybrid.
205: *
206: * XXX - ip_checkinterface currently must be disabled if you use ipnat
207: * to translate the destination address to another local interface.
208: *
209: * XXX - ip_checkinterface must be disabled if you add IP aliases
210: * to the loopback interface instead of the interface where the
211: * packets for those addresses are received.
212: */
213: int ip_checkinterface = 0;
214:
1.1 cgd 215:
1.60 kml 216: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
217:
1.1 cgd 218: extern struct domain inetdomain;
219: int ipqmaxlen = IFQ_MAXLEN;
1.150 matt 220: u_long in_ifaddrhash; /* size of hash table - 1 */
221: int in_ifaddrentries; /* total number of addrs */
1.181 jonathan 222: struct in_ifaddrhead in_ifaddrhead;
1.57 tls 223: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.166 matt 224: u_long in_multihash; /* size of hash table - 1 */
225: int in_multientries; /* total number of addrs */
226: struct in_multihashhead *in_multihashtbl;
1.13 mycroft 227: struct ifqueue ipintrq;
1.63 matt 228: struct ipstat ipstat;
1.183 ! jonathan 229: uint16_t ip_id;
1.75 thorpej 230:
1.121 thorpej 231: #ifdef PFIL_HOOKS
232: struct pfil_head inet_pfil_hook;
233: #endif
234:
1.63 matt 235: struct ipqhead ipq;
1.75 thorpej 236: int ipq_locked;
1.131 itojun 237: int ip_nfragpackets = 0;
1.133 itojun 238: int ip_maxfragpackets = 200;
1.75 thorpej 239:
240: static __inline int ipq_lock_try __P((void));
241: static __inline void ipq_unlock __P((void));
242:
243: static __inline int
244: ipq_lock_try()
245: {
246: int s;
247:
1.132 thorpej 248: /*
1.149 wiz 249: * Use splvm() -- we're blocking things that would cause
1.132 thorpej 250: * mbuf allocation.
251: */
252: s = splvm();
1.75 thorpej 253: if (ipq_locked) {
254: splx(s);
255: return (0);
256: }
257: ipq_locked = 1;
258: splx(s);
259: return (1);
260: }
261:
262: static __inline void
263: ipq_unlock()
264: {
265: int s;
266:
1.132 thorpej 267: s = splvm();
1.75 thorpej 268: ipq_locked = 0;
269: splx(s);
270: }
271:
272: #ifdef DIAGNOSTIC
273: #define IPQ_LOCK() \
274: do { \
275: if (ipq_lock_try() == 0) { \
276: printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
277: panic("ipq_lock"); \
278: } \
1.159 perry 279: } while (/*CONSTCOND*/ 0)
1.75 thorpej 280: #define IPQ_LOCK_CHECK() \
281: do { \
282: if (ipq_locked == 0) { \
283: printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
284: panic("ipq lock check"); \
285: } \
1.159 perry 286: } while (/*CONSTCOND*/ 0)
1.75 thorpej 287: #else
288: #define IPQ_LOCK() (void) ipq_lock_try()
289: #define IPQ_LOCK_CHECK() /* nothing */
290: #endif
291:
292: #define IPQ_UNLOCK() ipq_unlock()
1.1 cgd 293:
1.166 matt 294: struct pool inmulti_pool;
1.72 thorpej 295: struct pool ipqent_pool;
296:
1.135 thorpej 297: #ifdef INET_CSUM_COUNTERS
298: #include <sys/device.h>
299:
300: struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
301: NULL, "inet", "hwcsum bad");
302: struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
303: NULL, "inet", "hwcsum ok");
304: struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
305: NULL, "inet", "swcsum");
306:
307: #define INET_CSUM_COUNTER_INCR(ev) (ev)->ev_count++
308:
309: #else
310:
311: #define INET_CSUM_COUNTER_INCR(ev) /* nothing */
312:
313: #endif /* INET_CSUM_COUNTERS */
314:
1.1 cgd 315: /*
316: * We need to save the IP options in case a protocol wants to respond
317: * to an incoming packet over the same route if the packet got here
318: * using IP source routing. This allows connection establishment and
319: * maintenance when the remote end is on a network that is not known
320: * to us.
321: */
322: int ip_nhops = 0;
323: static struct ip_srcrt {
324: struct in_addr dst; /* final destination */
325: char nop; /* one NOP to align */
326: char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
327: struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
328: } ip_srcrt;
329:
1.13 mycroft 330: static void save_rte __P((u_char *, struct in_addr));
1.35 mycroft 331:
1.164 matt 332: #ifdef MBUFTRACE
333: struct mowner ip_rx_mowner = { "internet", "rx" };
334: struct mowner ip_tx_mowner = { "internet", "tx" };
335: #endif
336:
1.1 cgd 337: /*
338: * IP initialization: fill in IP protocol switch table.
339: * All protocols not implemented in kernel go to raw IP protocol handler.
340: */
1.8 mycroft 341: void
1.1 cgd 342: ip_init()
343: {
1.109 augustss 344: struct protosw *pr;
345: int i;
1.1 cgd 346:
1.166 matt 347: pool_init(&inmulti_pool, sizeof(struct in_multi), 0, 0, 0, "inmltpl",
348: NULL);
1.72 thorpej 349: pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
1.146 thorpej 350: NULL);
1.72 thorpej 351:
1.1 cgd 352: pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
353: if (pr == 0)
354: panic("ip_init");
355: for (i = 0; i < IPPROTO_MAX; i++)
356: ip_protox[i] = pr - inetsw;
357: for (pr = inetdomain.dom_protosw;
358: pr < inetdomain.dom_protoswNPROTOSW; pr++)
359: if (pr->pr_domain->dom_family == PF_INET &&
360: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
361: ip_protox[pr->pr_protocol] = pr - inetsw;
1.25 cgd 362: LIST_INIT(&ipq);
1.183 ! jonathan 363: ip_id = time.tv_sec & 0xfffff;
1.1 cgd 364: ipintrq.ifq_maxlen = ipqmaxlen;
1.181 jonathan 365: TAILQ_INIT(&in_ifaddrhead);
1.120 ad 366: in_ifaddrhashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IFADDR,
367: M_WAITOK, &in_ifaddrhash);
1.166 matt 368: in_multihashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IPMADDR,
369: M_WAITOK, &in_multihash);
1.160 itojun 370: ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
1.73 thorpej 371: #ifdef GATEWAY
372: ipflow_init();
373: #endif
1.121 thorpej 374:
375: #ifdef PFIL_HOOKS
376: /* Register our Packet Filter hook. */
1.126 thorpej 377: inet_pfil_hook.ph_type = PFIL_TYPE_AF;
378: inet_pfil_hook.ph_af = AF_INET;
1.121 thorpej 379: i = pfil_head_register(&inet_pfil_hook);
380: if (i != 0)
381: printf("ip_init: WARNING: unable to register pfil hook, "
382: "error %d\n", i);
383: #endif /* PFIL_HOOKS */
1.135 thorpej 384:
385: #ifdef INET_CSUM_COUNTERS
386: evcnt_attach_static(&ip_hwcsum_bad);
387: evcnt_attach_static(&ip_hwcsum_ok);
388: evcnt_attach_static(&ip_swcsum);
389: #endif /* INET_CSUM_COUNTERS */
1.164 matt 390:
391: #ifdef MBUFTRACE
392: MOWNER_ATTACH(&ip_tx_mowner);
393: MOWNER_ATTACH(&ip_rx_mowner);
394: #endif /* MBUFTRACE */
1.1 cgd 395: }
396:
397: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
398: struct route ipforward_rt;
399:
400: /*
1.89 itojun 401: * IP software interrupt routine
402: */
403: void
404: ipintr()
405: {
406: int s;
407: struct mbuf *m;
408:
409: while (1) {
1.132 thorpej 410: s = splnet();
1.89 itojun 411: IF_DEQUEUE(&ipintrq, m);
412: splx(s);
413: if (m == 0)
414: return;
1.164 matt 415: MCLAIM(m, &ip_rx_mowner);
1.89 itojun 416: ip_input(m);
417: }
418: }
419:
420: /*
1.1 cgd 421: * Ip input routine. Checksum and byte swap header. If fragmented
422: * try to reassemble. Process options. Pass to next level.
423: */
1.8 mycroft 424: void
1.89 itojun 425: ip_input(struct mbuf *m)
1.1 cgd 426: {
1.109 augustss 427: struct ip *ip = NULL;
428: struct ipq *fp;
429: struct in_ifaddr *ia;
430: struct ifaddr *ifa;
1.25 cgd 431: struct ipqent *ipqe;
1.89 itojun 432: int hlen = 0, mff, len;
1.100 itojun 433: int downmatch;
1.165 christos 434: int checkif;
1.169 itojun 435: int srcrt = 0;
1.173 jonathan 436: #ifdef FAST_IPSEC
437: struct m_tag *mtag;
438: struct tdb_ident *tdbi;
439: struct secpolicy *sp;
440: int s, error;
441: #endif /* FAST_IPSEC */
1.1 cgd 442:
1.164 matt 443: MCLAIM(m, &ip_rx_mowner);
1.1 cgd 444: #ifdef DIAGNOSTIC
445: if ((m->m_flags & M_PKTHDR) == 0)
446: panic("ipintr no HDR");
1.89 itojun 447: #endif
1.164 matt 448:
1.1 cgd 449: /*
450: * If no IP addresses have been set yet but the interfaces
451: * are receiving, can't do anything with incoming packets yet.
452: */
1.181 jonathan 453: if (TAILQ_FIRST(&in_ifaddrhead) == 0)
1.1 cgd 454: goto bad;
455: ipstat.ips_total++;
1.154 thorpej 456: /*
457: * If the IP header is not aligned, slurp it up into a new
458: * mbuf with space for link headers, in the event we forward
459: * it. Otherwise, if it is aligned, make sure the entire
460: * base IP header is in the first mbuf of the chain.
461: */
462: if (IP_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) {
463: if ((m = m_copyup(m, sizeof(struct ip),
464: (max_linkhdr + 3) & ~3)) == NULL) {
465: /* XXXJRT new stat, please */
466: ipstat.ips_toosmall++;
467: return;
468: }
469: } else if (__predict_false(m->m_len < sizeof (struct ip))) {
470: if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
471: ipstat.ips_toosmall++;
472: return;
473: }
1.1 cgd 474: }
475: ip = mtod(m, struct ip *);
1.13 mycroft 476: if (ip->ip_v != IPVERSION) {
477: ipstat.ips_badvers++;
478: goto bad;
479: }
1.1 cgd 480: hlen = ip->ip_hl << 2;
481: if (hlen < sizeof(struct ip)) { /* minimum header length */
482: ipstat.ips_badhlen++;
483: goto bad;
484: }
485: if (hlen > m->m_len) {
486: if ((m = m_pullup(m, hlen)) == 0) {
487: ipstat.ips_badhlen++;
1.89 itojun 488: return;
1.1 cgd 489: }
490: ip = mtod(m, struct ip *);
491: }
1.98 thorpej 492:
1.85 hwr 493: /*
1.99 thorpej 494: * RFC1122: packets with a multicast source address are
1.98 thorpej 495: * not allowed.
1.85 hwr 496: */
497: if (IN_MULTICAST(ip->ip_src.s_addr)) {
1.130 itojun 498: ipstat.ips_badaddr++;
1.85 hwr 499: goto bad;
1.129 itojun 500: }
501:
502: /* 127/8 must not appear on wire - RFC1122 */
503: if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
504: (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
1.130 itojun 505: if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
506: ipstat.ips_badaddr++;
1.129 itojun 507: goto bad;
1.130 itojun 508: }
1.85 hwr 509: }
510:
1.135 thorpej 511: switch (m->m_pkthdr.csum_flags &
1.137 thorpej 512: ((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
1.135 thorpej 513: M_CSUM_IPv4_BAD)) {
514: case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
515: INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
516: goto badcsum;
517:
518: case M_CSUM_IPv4:
519: /* Checksum was okay. */
520: INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
521: break;
522:
523: default:
524: /* Must compute it ourselves. */
525: INET_CSUM_COUNTER_INCR(&ip_swcsum);
526: if (in_cksum(m, hlen) != 0)
527: goto bad;
528: break;
1.1 cgd 529: }
530:
1.121 thorpej 531: /* Retrieve the packet length. */
532: len = ntohs(ip->ip_len);
1.81 proff 533:
534: /*
535: * Check for additional length bogosity
536: */
1.84 proff 537: if (len < hlen) {
1.81 proff 538: ipstat.ips_badlen++;
539: goto bad;
540: }
1.1 cgd 541:
542: /*
543: * Check that the amount of data in the buffers
544: * is as at least much as the IP header would have us expect.
545: * Trim mbufs if longer than we expect.
546: * Drop packet if shorter than we expect.
547: */
1.35 mycroft 548: if (m->m_pkthdr.len < len) {
1.1 cgd 549: ipstat.ips_tooshort++;
550: goto bad;
551: }
1.35 mycroft 552: if (m->m_pkthdr.len > len) {
1.1 cgd 553: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 554: m->m_len = len;
555: m->m_pkthdr.len = len;
1.1 cgd 556: } else
1.35 mycroft 557: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 558: }
559:
1.94 itojun 560: #ifdef IPSEC
1.149 wiz 561: /* ipflow (IP fast forwarding) is not compatible with IPsec. */
1.94 itojun 562: m->m_flags &= ~M_CANFASTFWD;
563: #else
1.64 thorpej 564: /*
565: * Assume that we can create a fast-forward IP flow entry
566: * based on this packet.
567: */
568: m->m_flags |= M_CANFASTFWD;
1.94 itojun 569: #endif
1.64 thorpej 570:
1.36 mrg 571: #ifdef PFIL_HOOKS
1.33 mrg 572: /*
1.64 thorpej 573: * Run through list of hooks for input packets. If there are any
574: * filters which require that additional packets in the flow are
575: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
576: * Note that filters must _never_ set this flag, as another filter
577: * in the list may have previously cleared it.
1.33 mrg 578: */
1.127 itojun 579: /*
580: * let ipfilter look at packet on the wire,
581: * not the decapsulated packet.
582: */
583: #ifdef IPSEC
1.136 itojun 584: if (!ipsec_getnhist(m))
1.127 itojun 585: #else
586: if (1)
587: #endif
588: {
1.169 itojun 589: struct in_addr odst;
590:
591: odst = ip->ip_dst;
1.127 itojun 592: if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
1.168 itojun 593: PFIL_IN) != 0)
594: return;
1.127 itojun 595: if (m == NULL)
596: return;
597: ip = mtod(m, struct ip *);
1.142 darrenr 598: hlen = ip->ip_hl << 2;
1.169 itojun 599: srcrt = (odst.s_addr != ip->ip_dst.s_addr);
1.127 itojun 600: }
1.36 mrg 601: #endif /* PFIL_HOOKS */
1.123 thorpej 602:
603: #ifdef ALTQ
604: /* XXX Temporary until ALTQ is changed to use a pfil hook */
605: if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
606: /* packet dropped by traffic conditioner */
607: return;
608: }
609: #endif
1.121 thorpej 610:
611: /*
1.1 cgd 612: * Process options and, if not destined for us,
613: * ship it on. ip_dooptions returns 1 when an
614: * error was detected (causing an icmp message
615: * to be sent and the original packet to be freed).
616: */
617: ip_nhops = 0; /* for source routed packets */
618: if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.89 itojun 619: return;
1.1 cgd 620:
621: /*
1.165 christos 622: * Enable a consistency check between the destination address
623: * and the arrival interface for a unicast packet (the RFC 1122
624: * strong ES model) if IP forwarding is disabled and the packet
625: * is not locally generated.
626: *
627: * XXX - Checking also should be disabled if the destination
628: * address is ipnat'ed to a different interface.
629: *
630: * XXX - Checking is incompatible with IP aliases added
631: * to the loopback interface instead of the interface where
632: * the packets are received.
633: *
634: * XXX - We need to add a per ifaddr flag for this so that
635: * we get finer grain control.
636: */
637: checkif = ip_checkinterface && (ipforwarding == 0) &&
638: (m->m_pkthdr.rcvif != NULL) &&
639: ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0);
640:
641: /*
1.1 cgd 642: * Check our list of addresses, to see if the packet is for us.
1.100 itojun 643: *
644: * Traditional 4.4BSD did not consult IFF_UP at all.
645: * The behavior here is to treat addresses on !IFF_UP interface
646: * as not mine.
1.1 cgd 647: */
1.100 itojun 648: downmatch = 0;
1.140 matt 649: LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
1.97 itojun 650: if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
1.165 christos 651: if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif)
652: continue;
1.97 itojun 653: if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
654: break;
1.100 itojun 655: else
656: downmatch++;
1.97 itojun 657: }
658: }
1.86 thorpej 659: if (ia != NULL)
660: goto ours;
1.57 tls 661: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
1.140 matt 662: TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) {
663: if (ifa->ifa_addr->sa_family != AF_INET)
664: continue;
1.57 tls 665: ia = ifatoia(ifa);
1.35 mycroft 666: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
667: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 668: /*
669: * Look for all-0's host part (old broadcast addr),
670: * either for subnet or net.
671: */
672: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 673: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 674: goto ours;
1.57 tls 675: /*
676: * An interface with IP address zero accepts
677: * all packets that arrive on that interface.
678: */
679: if (in_nullhost(ia->ia_addr.sin_addr))
680: goto ours;
1.1 cgd 681: }
682: }
1.18 mycroft 683: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 684: struct in_multi *inm;
685: #ifdef MROUTING
686: extern struct socket *ip_mrouter;
1.10 brezak 687:
1.147 matt 688: if (M_READONLY(m)) {
1.10 brezak 689: if ((m = m_pullup(m, hlen)) == 0) {
690: ipstat.ips_toosmall++;
1.89 itojun 691: return;
1.10 brezak 692: }
693: ip = mtod(m, struct ip *);
694: }
1.4 hpeyerl 695:
696: if (ip_mrouter) {
697: /*
698: * If we are acting as a multicast router, all
699: * incoming multicast packets are passed to the
700: * kernel-level multicast forwarding function.
701: * The packet is returned (relatively) intact; if
702: * ip_mforward() returns a non-zero value, the packet
703: * must be discarded, else it may be accepted below.
704: *
705: * (The IP ident field is put in the same byte order
706: * as expected when ip_mforward() is called from
707: * ip_output().)
708: */
1.13 mycroft 709: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
710: ipstat.ips_cantforward++;
1.4 hpeyerl 711: m_freem(m);
1.89 itojun 712: return;
1.4 hpeyerl 713: }
714:
715: /*
716: * The process-level routing demon needs to receive
717: * all multicast IGMP packets, whether or not this
718: * host belongs to their destination groups.
719: */
720: if (ip->ip_p == IPPROTO_IGMP)
721: goto ours;
1.13 mycroft 722: ipstat.ips_forward++;
1.4 hpeyerl 723: }
724: #endif
725: /*
726: * See if we belong to the destination multicast group on the
727: * arrival interface.
728: */
729: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
730: if (inm == NULL) {
1.13 mycroft 731: ipstat.ips_cantforward++;
1.4 hpeyerl 732: m_freem(m);
1.89 itojun 733: return;
1.4 hpeyerl 734: }
735: goto ours;
736: }
1.19 mycroft 737: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 738: in_nullhost(ip->ip_dst))
1.1 cgd 739: goto ours;
740:
741: /*
742: * Not for us; forward if possible and desirable.
743: */
744: if (ipforwarding == 0) {
745: ipstat.ips_cantforward++;
746: m_freem(m);
1.100 itojun 747: } else {
748: /*
749: * If ip_dst matched any of my address on !IFF_UP interface,
750: * and there's no IFF_UP interface that matches ip_dst,
751: * send icmp unreach. Forwarding it will result in in-kernel
752: * forwarding loop till TTL goes to 0.
753: */
754: if (downmatch) {
755: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
756: ipstat.ips_cantforward++;
757: return;
758: }
1.145 itojun 759: #ifdef IPSEC
760: if (ipsec4_in_reject(m, NULL)) {
761: ipsecstat.in_polvio++;
762: goto bad;
763: }
764: #endif
1.173 jonathan 765: #ifdef FAST_IPSEC
766: mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
767: s = splsoftnet();
768: if (mtag != NULL) {
769: tdbi = (struct tdb_ident *)(mtag + 1);
770: sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
771: } else {
772: sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
773: IP_FORWARDING, &error);
774: }
775: if (sp == NULL) { /* NB: can happen if error */
776: splx(s);
777: /*XXX error stat???*/
778: DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
779: goto bad;
780: }
781:
782: /*
783: * Check security policy against packet attributes.
784: */
785: error = ipsec_in_reject(sp, m);
786: KEY_FREESP(&sp);
787: splx(s);
788: if (error) {
789: ipstat.ips_cantforward++;
790: goto bad;
791: }
792: #endif /* FAST_IPSEC */
1.145 itojun 793:
1.169 itojun 794: ip_forward(m, srcrt);
1.100 itojun 795: }
1.89 itojun 796: return;
1.1 cgd 797:
798: ours:
799: /*
800: * If offset or IP_MF are set, must reassemble.
801: * Otherwise, nothing need be done.
802: * (We could look in the reassembly queue to see
803: * if the packet was previously fragmented,
804: * but it's not worth the time; just let them time out.)
805: */
1.155 itojun 806: if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
807: if (M_READONLY(m)) {
808: if ((m = m_pullup(m, hlen)) == NULL) {
809: ipstat.ips_toosmall++;
810: goto bad;
811: }
812: ip = mtod(m, struct ip *);
813: }
814:
1.1 cgd 815: /*
816: * Look for queue of fragments
817: * of this datagram.
818: */
1.75 thorpej 819: IPQ_LOCK();
1.140 matt 820: LIST_FOREACH(fp, &ipq, ipq_q)
1.1 cgd 821: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 822: in_hosteq(ip->ip_src, fp->ipq_src) &&
823: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 824: ip->ip_p == fp->ipq_p)
825: goto found;
826: fp = 0;
827: found:
828:
829: /*
830: * Adjust ip_len to not reflect header,
1.25 cgd 831: * set ipqe_mff if more fragments are expected,
1.1 cgd 832: * convert offset of this to bytes.
833: */
1.155 itojun 834: ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
835: mff = (ip->ip_off & htons(IP_MF)) != 0;
1.25 cgd 836: if (mff) {
1.16 cgd 837: /*
838: * Make sure that fragments have a data length
839: * that's a non-zero multiple of 8 bytes.
840: */
1.155 itojun 841: if (ntohs(ip->ip_len) == 0 ||
842: (ntohs(ip->ip_len) & 0x7) != 0) {
1.16 cgd 843: ipstat.ips_badfrags++;
1.75 thorpej 844: IPQ_UNLOCK();
1.16 cgd 845: goto bad;
846: }
847: }
1.155 itojun 848: ip->ip_off = htons((ntohs(ip->ip_off) & IP_OFFMASK) << 3);
1.1 cgd 849:
850: /*
851: * If datagram marked as having more fragments
852: * or if this is not the first fragment,
853: * attempt reassembly; if it succeeds, proceed.
854: */
1.155 itojun 855: if (mff || ip->ip_off != htons(0)) {
1.1 cgd 856: ipstat.ips_fragments++;
1.72 thorpej 857: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 858: if (ipqe == NULL) {
859: ipstat.ips_rcvmemdrop++;
1.75 thorpej 860: IPQ_UNLOCK();
1.25 cgd 861: goto bad;
862: }
863: ipqe->ipqe_mff = mff;
1.50 thorpej 864: ipqe->ipqe_m = m;
1.25 cgd 865: ipqe->ipqe_ip = ip;
1.50 thorpej 866: m = ip_reass(ipqe, fp);
1.75 thorpej 867: if (m == 0) {
868: IPQ_UNLOCK();
1.89 itojun 869: return;
1.75 thorpej 870: }
1.13 mycroft 871: ipstat.ips_reassembled++;
1.50 thorpej 872: ip = mtod(m, struct ip *);
1.74 thorpej 873: hlen = ip->ip_hl << 2;
1.155 itojun 874: ip->ip_len = htons(ntohs(ip->ip_len) + hlen);
1.1 cgd 875: } else
876: if (fp)
877: ip_freef(fp);
1.75 thorpej 878: IPQ_UNLOCK();
1.79 mycroft 879: }
1.128 itojun 880:
1.173 jonathan 881: #if defined(IPSEC)
1.128 itojun 882: /*
883: * enforce IPsec policy checking if we are seeing last header.
884: * note that we do not visit this with protocols with pcb layer
885: * code - like udp/tcp/raw ip.
886: */
887: if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
888: ipsec4_in_reject(m, NULL)) {
889: ipsecstat.in_polvio++;
890: goto bad;
891: }
892: #endif
1.173 jonathan 893: #if FAST_IPSEC
894: /*
895: * enforce IPsec policy checking if we are seeing last header.
896: * note that we do not visit this with protocols with pcb layer
897: * code - like udp/tcp/raw ip.
898: */
899: if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
900: /*
901: * Check if the packet has already had IPsec processing
902: * done. If so, then just pass it along. This tag gets
903: * set during AH, ESP, etc. input handling, before the
904: * packet is returned to the ip input queue for delivery.
905: */
906: mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
907: s = splsoftnet();
908: if (mtag != NULL) {
909: tdbi = (struct tdb_ident *)(mtag + 1);
910: sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
911: } else {
912: sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
913: IP_FORWARDING, &error);
914: }
915: if (sp != NULL) {
916: /*
917: * Check security policy against packet attributes.
918: */
919: error = ipsec_in_reject(sp, m);
920: KEY_FREESP(&sp);
921: } else {
922: /* XXX error stat??? */
923: error = EINVAL;
924: DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
925: goto bad;
926: }
927: splx(s);
928: if (error)
929: goto bad;
930: }
931: #endif /* FAST_IPSEC */
1.1 cgd 932:
933: /*
934: * Switch out to protocol's input routine.
935: */
1.82 aidan 936: #if IFA_STATS
1.122 itojun 937: if (ia && ip)
1.155 itojun 938: ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
1.82 aidan 939: #endif
1.1 cgd 940: ipstat.ips_delivered++;
1.89 itojun 941: {
942: int off = hlen, nh = ip->ip_p;
943:
944: (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
945: return;
946: }
1.1 cgd 947: bad:
948: m_freem(m);
1.135 thorpej 949: return;
950:
951: badcsum:
952: ipstat.ips_badsum++;
953: m_freem(m);
1.1 cgd 954: }
955:
956: /*
957: * Take incoming datagram fragment and try to
958: * reassemble it into whole datagram. If a chain for
959: * reassembly of this datagram already exists, then it
960: * is given as fp; otherwise have to make a chain.
961: */
1.50 thorpej 962: struct mbuf *
1.25 cgd 963: ip_reass(ipqe, fp)
1.109 augustss 964: struct ipqent *ipqe;
965: struct ipq *fp;
1.1 cgd 966: {
1.109 augustss 967: struct mbuf *m = ipqe->ipqe_m;
968: struct ipqent *nq, *p, *q;
1.25 cgd 969: struct ip *ip;
1.1 cgd 970: struct mbuf *t;
1.25 cgd 971: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 972: int i, next;
973:
1.75 thorpej 974: IPQ_LOCK_CHECK();
975:
1.1 cgd 976: /*
977: * Presence of header sizes in mbufs
978: * would confuse code below.
979: */
980: m->m_data += hlen;
981: m->m_len -= hlen;
982:
983: /*
984: * If first fragment to arrive, create a reassembly queue.
985: */
986: if (fp == 0) {
1.131 itojun 987: /*
988: * Enforce upper bound on number of fragmented packets
989: * for which we attempt reassembly;
990: * If maxfrag is 0, never accept fragments.
991: * If maxfrag is -1, accept all fragments without limitation.
992: */
993: if (ip_maxfragpackets < 0)
994: ;
995: else if (ip_nfragpackets >= ip_maxfragpackets)
996: goto dropfrag;
997: ip_nfragpackets++;
1.50 thorpej 998: MALLOC(fp, struct ipq *, sizeof (struct ipq),
999: M_FTABLE, M_NOWAIT);
1000: if (fp == NULL)
1.1 cgd 1001: goto dropfrag;
1.25 cgd 1002: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 1003: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 1004: fp->ipq_p = ipqe->ipqe_ip->ip_p;
1005: fp->ipq_id = ipqe->ipqe_ip->ip_id;
1.148 matt 1006: TAILQ_INIT(&fp->ipq_fragq);
1.25 cgd 1007: fp->ipq_src = ipqe->ipqe_ip->ip_src;
1008: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
1009: p = NULL;
1.1 cgd 1010: goto insert;
1011: }
1012:
1013: /*
1014: * Find a segment which begins after this one does.
1015: */
1.148 matt 1016: for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
1017: p = q, q = TAILQ_NEXT(q, ipqe_q))
1.155 itojun 1018: if (ntohs(q->ipqe_ip->ip_off) > ntohs(ipqe->ipqe_ip->ip_off))
1.1 cgd 1019: break;
1020:
1021: /*
1022: * If there is a preceding segment, it may provide some of
1023: * our data already. If so, drop the data from the incoming
1024: * segment. If it provides all of our data, drop us.
1025: */
1.25 cgd 1026: if (p != NULL) {
1.155 itojun 1027: i = ntohs(p->ipqe_ip->ip_off) + ntohs(p->ipqe_ip->ip_len) -
1028: ntohs(ipqe->ipqe_ip->ip_off);
1.1 cgd 1029: if (i > 0) {
1.155 itojun 1030: if (i >= ntohs(ipqe->ipqe_ip->ip_len))
1.1 cgd 1031: goto dropfrag;
1.50 thorpej 1032: m_adj(ipqe->ipqe_m, i);
1.155 itojun 1033: ipqe->ipqe_ip->ip_off =
1034: htons(ntohs(ipqe->ipqe_ip->ip_off) + i);
1035: ipqe->ipqe_ip->ip_len =
1036: htons(ntohs(ipqe->ipqe_ip->ip_len) - i);
1.1 cgd 1037: }
1038: }
1039:
1040: /*
1041: * While we overlap succeeding segments trim them or,
1042: * if they are completely covered, dequeue them.
1043: */
1.155 itojun 1044: for (; q != NULL &&
1045: ntohs(ipqe->ipqe_ip->ip_off) + ntohs(ipqe->ipqe_ip->ip_len) >
1046: ntohs(q->ipqe_ip->ip_off); q = nq) {
1047: i = (ntohs(ipqe->ipqe_ip->ip_off) +
1048: ntohs(ipqe->ipqe_ip->ip_len)) - ntohs(q->ipqe_ip->ip_off);
1049: if (i < ntohs(q->ipqe_ip->ip_len)) {
1050: q->ipqe_ip->ip_len =
1051: htons(ntohs(q->ipqe_ip->ip_len) - i);
1052: q->ipqe_ip->ip_off =
1053: htons(ntohs(q->ipqe_ip->ip_off) + i);
1.50 thorpej 1054: m_adj(q->ipqe_m, i);
1.1 cgd 1055: break;
1056: }
1.148 matt 1057: nq = TAILQ_NEXT(q, ipqe_q);
1.50 thorpej 1058: m_freem(q->ipqe_m);
1.148 matt 1059: TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72 thorpej 1060: pool_put(&ipqent_pool, q);
1.1 cgd 1061: }
1062:
1063: insert:
1064: /*
1065: * Stick new segment in its place;
1066: * check for complete reassembly.
1067: */
1.25 cgd 1068: if (p == NULL) {
1.148 matt 1069: TAILQ_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
1.25 cgd 1070: } else {
1.148 matt 1071: TAILQ_INSERT_AFTER(&fp->ipq_fragq, p, ipqe, ipqe_q);
1.25 cgd 1072: }
1.1 cgd 1073: next = 0;
1.148 matt 1074: for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
1075: p = q, q = TAILQ_NEXT(q, ipqe_q)) {
1.155 itojun 1076: if (ntohs(q->ipqe_ip->ip_off) != next)
1.1 cgd 1077: return (0);
1.155 itojun 1078: next += ntohs(q->ipqe_ip->ip_len);
1.1 cgd 1079: }
1.25 cgd 1080: if (p->ipqe_mff)
1.1 cgd 1081: return (0);
1082:
1083: /*
1.41 thorpej 1084: * Reassembly is complete. Check for a bogus message size and
1085: * concatenate fragments.
1.1 cgd 1086: */
1.148 matt 1087: q = TAILQ_FIRST(&fp->ipq_fragq);
1.25 cgd 1088: ip = q->ipqe_ip;
1.41 thorpej 1089: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
1090: ipstat.ips_toolong++;
1091: ip_freef(fp);
1092: return (0);
1093: }
1.50 thorpej 1094: m = q->ipqe_m;
1.1 cgd 1095: t = m->m_next;
1096: m->m_next = 0;
1097: m_cat(m, t);
1.148 matt 1098: nq = TAILQ_NEXT(q, ipqe_q);
1.72 thorpej 1099: pool_put(&ipqent_pool, q);
1.25 cgd 1100: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 1101: t = q->ipqe_m;
1.148 matt 1102: nq = TAILQ_NEXT(q, ipqe_q);
1.72 thorpej 1103: pool_put(&ipqent_pool, q);
1.1 cgd 1104: m_cat(m, t);
1105: }
1106:
1107: /*
1108: * Create header for new ip packet by
1109: * modifying header of first packet;
1110: * dequeue and discard fragment reassembly header.
1111: * Make header visible.
1112: */
1.155 itojun 1113: ip->ip_len = htons(next);
1.25 cgd 1114: ip->ip_src = fp->ipq_src;
1115: ip->ip_dst = fp->ipq_dst;
1116: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 1117: FREE(fp, M_FTABLE);
1.131 itojun 1118: ip_nfragpackets--;
1.1 cgd 1119: m->m_len += (ip->ip_hl << 2);
1120: m->m_data -= (ip->ip_hl << 2);
1121: /* some debugging cruft by sklower, below, will go away soon */
1122: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1.109 augustss 1123: int plen = 0;
1.50 thorpej 1124: for (t = m; t; t = t->m_next)
1125: plen += t->m_len;
1126: m->m_pkthdr.len = plen;
1.1 cgd 1127: }
1.50 thorpej 1128: return (m);
1.1 cgd 1129:
1130: dropfrag:
1131: ipstat.ips_fragdropped++;
1132: m_freem(m);
1.72 thorpej 1133: pool_put(&ipqent_pool, ipqe);
1.1 cgd 1134: return (0);
1135: }
1136:
1137: /*
1138: * Free a fragment reassembly header and all
1139: * associated datagrams.
1140: */
1.8 mycroft 1141: void
1.1 cgd 1142: ip_freef(fp)
1143: struct ipq *fp;
1144: {
1.109 augustss 1145: struct ipqent *q, *p;
1.1 cgd 1146:
1.75 thorpej 1147: IPQ_LOCK_CHECK();
1148:
1.148 matt 1149: for (q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL; q = p) {
1150: p = TAILQ_NEXT(q, ipqe_q);
1.50 thorpej 1151: m_freem(q->ipqe_m);
1.148 matt 1152: TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72 thorpej 1153: pool_put(&ipqent_pool, q);
1.1 cgd 1154: }
1.25 cgd 1155: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 1156: FREE(fp, M_FTABLE);
1.131 itojun 1157: ip_nfragpackets--;
1.1 cgd 1158: }
1159:
1160: /*
1161: * IP timer processing;
1162: * if a timer expires on a reassembly
1163: * queue, discard it.
1164: */
1.8 mycroft 1165: void
1.1 cgd 1166: ip_slowtimo()
1167: {
1.109 augustss 1168: struct ipq *fp, *nfp;
1.24 mycroft 1169: int s = splsoftnet();
1.1 cgd 1170:
1.75 thorpej 1171: IPQ_LOCK();
1.140 matt 1172: for (fp = LIST_FIRST(&ipq); fp != NULL; fp = nfp) {
1173: nfp = LIST_NEXT(fp, ipq_q);
1.25 cgd 1174: if (--fp->ipq_ttl == 0) {
1.1 cgd 1175: ipstat.ips_fragtimeout++;
1.25 cgd 1176: ip_freef(fp);
1.1 cgd 1177: }
1178: }
1.131 itojun 1179: /*
1180: * If we are over the maximum number of fragments
1181: * (due to the limit being lowered), drain off
1182: * enough to get down to the new limit.
1183: */
1184: if (ip_maxfragpackets < 0)
1185: ;
1186: else {
1.140 matt 1187: while (ip_nfragpackets > ip_maxfragpackets && LIST_FIRST(&ipq))
1188: ip_freef(LIST_FIRST(&ipq));
1.131 itojun 1189: }
1.75 thorpej 1190: IPQ_UNLOCK();
1.63 matt 1191: #ifdef GATEWAY
1192: ipflow_slowtimo();
1193: #endif
1.1 cgd 1194: splx(s);
1195: }
1196:
1197: /*
1198: * Drain off all datagram fragments.
1199: */
1.8 mycroft 1200: void
1.1 cgd 1201: ip_drain()
1202: {
1203:
1.75 thorpej 1204: /*
1205: * We may be called from a device's interrupt context. If
1206: * the ipq is already busy, just bail out now.
1207: */
1208: if (ipq_lock_try() == 0)
1209: return;
1210:
1.140 matt 1211: while (LIST_FIRST(&ipq) != NULL) {
1.1 cgd 1212: ipstat.ips_fragdropped++;
1.140 matt 1213: ip_freef(LIST_FIRST(&ipq));
1.1 cgd 1214: }
1.75 thorpej 1215:
1216: IPQ_UNLOCK();
1.1 cgd 1217: }
1218:
1219: /*
1220: * Do option processing on a datagram,
1221: * possibly discarding it if bad options are encountered,
1222: * or forwarding it if source-routed.
1223: * Returns 1 if packet has been forwarded/freed,
1224: * 0 if the packet should be processed further.
1225: */
1.8 mycroft 1226: int
1.1 cgd 1227: ip_dooptions(m)
1228: struct mbuf *m;
1229: {
1.109 augustss 1230: struct ip *ip = mtod(m, struct ip *);
1231: u_char *cp, *cp0;
1232: struct ip_timestamp *ipt;
1233: struct in_ifaddr *ia;
1.1 cgd 1234: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.104 thorpej 1235: struct in_addr dst;
1.1 cgd 1236: n_time ntime;
1237:
1.13 mycroft 1238: dst = ip->ip_dst;
1.1 cgd 1239: cp = (u_char *)(ip + 1);
1240: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
1241: for (; cnt > 0; cnt -= optlen, cp += optlen) {
1242: opt = cp[IPOPT_OPTVAL];
1243: if (opt == IPOPT_EOL)
1244: break;
1245: if (opt == IPOPT_NOP)
1246: optlen = 1;
1247: else {
1.113 itojun 1248: if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1249: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1250: goto bad;
1251: }
1.1 cgd 1252: optlen = cp[IPOPT_OLEN];
1.114 itojun 1253: if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1.1 cgd 1254: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1255: goto bad;
1256: }
1257: }
1258: switch (opt) {
1259:
1260: default:
1261: break;
1262:
1263: /*
1264: * Source routing with record.
1265: * Find interface with current destination address.
1266: * If none on this machine then drop if strictly routed,
1267: * or do nothing if loosely routed.
1268: * Record interface address and bring up next address
1269: * component. If strictly routed make sure next
1270: * address is on directly accessible net.
1271: */
1272: case IPOPT_LSRR:
1273: case IPOPT_SSRR:
1.47 cjs 1274: if (ip_allowsrcrt == 0) {
1275: type = ICMP_UNREACH;
1276: code = ICMP_UNREACH_NET_PROHIB;
1277: goto bad;
1278: }
1.114 itojun 1279: if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1280: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1281: goto bad;
1282: }
1.1 cgd 1283: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1284: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1285: goto bad;
1286: }
1287: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 1288: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 1289: if (ia == 0) {
1290: if (opt == IPOPT_SSRR) {
1291: type = ICMP_UNREACH;
1292: code = ICMP_UNREACH_SRCFAIL;
1293: goto bad;
1294: }
1295: /*
1296: * Loose routing, and not at next destination
1297: * yet; nothing to do except forward.
1298: */
1299: break;
1300: }
1301: off--; /* 0 origin */
1.112 sommerfe 1302: if ((off + sizeof(struct in_addr)) > optlen) {
1.1 cgd 1303: /*
1304: * End of source route. Should be for us.
1305: */
1306: save_rte(cp, ip->ip_src);
1307: break;
1308: }
1309: /*
1310: * locate outgoing interface
1311: */
1312: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
1313: sizeof(ipaddr.sin_addr));
1.96 thorpej 1314: if (opt == IPOPT_SSRR)
1315: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1316: else
1.1 cgd 1317: ia = ip_rtaddr(ipaddr.sin_addr);
1318: if (ia == 0) {
1319: type = ICMP_UNREACH;
1320: code = ICMP_UNREACH_SRCFAIL;
1321: goto bad;
1322: }
1323: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 1324: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1325: (caddr_t)(cp + off), sizeof(struct in_addr));
1326: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 1327: /*
1328: * Let ip_intr's mcast routing check handle mcast pkts
1329: */
1.18 mycroft 1330: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 1331: break;
1332:
1333: case IPOPT_RR:
1.114 itojun 1334: if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1335: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1336: goto bad;
1337: }
1.1 cgd 1338: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1339: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1340: goto bad;
1341: }
1342: /*
1343: * If no space remains, ignore.
1344: */
1345: off--; /* 0 origin */
1.112 sommerfe 1346: if ((off + sizeof(struct in_addr)) > optlen)
1.1 cgd 1347: break;
1348: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
1349: sizeof(ipaddr.sin_addr));
1350: /*
1351: * locate outgoing interface; if we're the destination,
1352: * use the incoming interface (should be same).
1353: */
1.96 thorpej 1354: if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
1355: == NULL &&
1356: (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1.1 cgd 1357: type = ICMP_UNREACH;
1358: code = ICMP_UNREACH_HOST;
1359: goto bad;
1360: }
1.20 mycroft 1361: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1362: (caddr_t)(cp + off), sizeof(struct in_addr));
1363: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1364: break;
1365:
1366: case IPOPT_TS:
1367: code = cp - (u_char *)ip;
1368: ipt = (struct ip_timestamp *)cp;
1.114 itojun 1369: if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1370: code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1.1 cgd 1371: goto bad;
1.114 itojun 1372: }
1373: if (ipt->ipt_ptr < 5) {
1374: code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1375: goto bad;
1376: }
1.15 cgd 1377: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.114 itojun 1378: if (++ipt->ipt_oflw == 0) {
1379: code = (u_char *)&ipt->ipt_ptr -
1380: (u_char *)ip;
1.1 cgd 1381: goto bad;
1.114 itojun 1382: }
1.1 cgd 1383: break;
1384: }
1.104 thorpej 1385: cp0 = (cp + ipt->ipt_ptr - 1);
1.1 cgd 1386: switch (ipt->ipt_flg) {
1387:
1388: case IPOPT_TS_TSONLY:
1389: break;
1390:
1391: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1392: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114 itojun 1393: sizeof(struct in_addr) > ipt->ipt_len) {
1394: code = (u_char *)&ipt->ipt_ptr -
1395: (u_char *)ip;
1.1 cgd 1396: goto bad;
1.114 itojun 1397: }
1.13 mycroft 1398: ipaddr.sin_addr = dst;
1.96 thorpej 1399: ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
1400: m->m_pkthdr.rcvif));
1.13 mycroft 1401: if (ia == 0)
1402: continue;
1.104 thorpej 1403: bcopy(&ia->ia_addr.sin_addr,
1404: cp0, sizeof(struct in_addr));
1.1 cgd 1405: ipt->ipt_ptr += sizeof(struct in_addr);
1406: break;
1407:
1408: case IPOPT_TS_PRESPEC:
1.66 thorpej 1409: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114 itojun 1410: sizeof(struct in_addr) > ipt->ipt_len) {
1411: code = (u_char *)&ipt->ipt_ptr -
1412: (u_char *)ip;
1.1 cgd 1413: goto bad;
1.114 itojun 1414: }
1.104 thorpej 1415: bcopy(cp0, &ipaddr.sin_addr,
1.1 cgd 1416: sizeof(struct in_addr));
1.96 thorpej 1417: if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
1418: == NULL)
1.1 cgd 1419: continue;
1420: ipt->ipt_ptr += sizeof(struct in_addr);
1421: break;
1422:
1423: default:
1.114 itojun 1424: /* XXX can't take &ipt->ipt_flg */
1425: code = (u_char *)&ipt->ipt_ptr -
1426: (u_char *)ip + 1;
1.1 cgd 1427: goto bad;
1428: }
1429: ntime = iptime();
1.107 thorpej 1430: cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1431: bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1,
1.1 cgd 1432: sizeof(n_time));
1433: ipt->ipt_ptr += sizeof(n_time);
1434: }
1435: }
1436: if (forward) {
1.26 thorpej 1437: if (ip_forwsrcrt == 0) {
1438: type = ICMP_UNREACH;
1439: code = ICMP_UNREACH_SRCFAIL;
1440: goto bad;
1441: }
1.1 cgd 1442: ip_forward(m, 1);
1443: return (1);
1.13 mycroft 1444: }
1445: return (0);
1.1 cgd 1446: bad:
1.13 mycroft 1447: icmp_error(m, type, code, 0, 0);
1448: ipstat.ips_badoptions++;
1.1 cgd 1449: return (1);
1450: }
1451:
1452: /*
1453: * Given address of next destination (final or next hop),
1454: * return internet address info of interface to be used to get there.
1455: */
1456: struct in_ifaddr *
1457: ip_rtaddr(dst)
1458: struct in_addr dst;
1459: {
1.109 augustss 1460: struct sockaddr_in *sin;
1.1 cgd 1461:
1.19 mycroft 1462: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1463:
1.35 mycroft 1464: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1465: if (ipforward_rt.ro_rt) {
1466: RTFREE(ipforward_rt.ro_rt);
1467: ipforward_rt.ro_rt = 0;
1468: }
1469: sin->sin_family = AF_INET;
1470: sin->sin_len = sizeof(*sin);
1471: sin->sin_addr = dst;
1472:
1473: rtalloc(&ipforward_rt);
1474: }
1475: if (ipforward_rt.ro_rt == 0)
1476: return ((struct in_ifaddr *)0);
1.19 mycroft 1477: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1478: }
1479:
1480: /*
1481: * Save incoming source route for use in replies,
1482: * to be picked up later by ip_srcroute if the receiver is interested.
1483: */
1.13 mycroft 1484: void
1.1 cgd 1485: save_rte(option, dst)
1486: u_char *option;
1487: struct in_addr dst;
1488: {
1489: unsigned olen;
1490:
1491: olen = option[IPOPT_OLEN];
1492: #ifdef DIAGNOSTIC
1493: if (ipprintfs)
1.39 christos 1494: printf("save_rte: olen %d\n", olen);
1.89 itojun 1495: #endif /* 0 */
1.1 cgd 1496: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1497: return;
1498: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1499: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1500: ip_srcrt.dst = dst;
1501: }
1502:
1503: /*
1504: * Retrieve incoming source route for use in replies,
1505: * in the same form used by setsockopt.
1506: * The first hop is placed before the options, will be removed later.
1507: */
1508: struct mbuf *
1509: ip_srcroute()
1510: {
1.109 augustss 1511: struct in_addr *p, *q;
1512: struct mbuf *m;
1.1 cgd 1513:
1514: if (ip_nhops == 0)
1515: return ((struct mbuf *)0);
1516: m = m_get(M_DONTWAIT, MT_SOOPTS);
1517: if (m == 0)
1518: return ((struct mbuf *)0);
1519:
1.164 matt 1520: MCLAIM(m, &inetdomain.dom_mowner);
1.13 mycroft 1521: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1522:
1523: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1524: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1525: OPTSIZ;
1526: #ifdef DIAGNOSTIC
1527: if (ipprintfs)
1.39 christos 1528: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1529: #endif
1530:
1531: /*
1532: * First save first hop for return route
1533: */
1534: p = &ip_srcrt.route[ip_nhops - 1];
1535: *(mtod(m, struct in_addr *)) = *p--;
1536: #ifdef DIAGNOSTIC
1537: if (ipprintfs)
1.39 christos 1538: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1539: #endif
1540:
1541: /*
1542: * Copy option fields and padding (nop) to mbuf.
1543: */
1544: ip_srcrt.nop = IPOPT_NOP;
1545: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1546: bcopy((caddr_t)&ip_srcrt.nop,
1547: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1548: q = (struct in_addr *)(mtod(m, caddr_t) +
1549: sizeof(struct in_addr) + OPTSIZ);
1550: #undef OPTSIZ
1551: /*
1552: * Record return path as an IP source route,
1553: * reversing the path (pointers are now aligned).
1554: */
1555: while (p >= ip_srcrt.route) {
1556: #ifdef DIAGNOSTIC
1557: if (ipprintfs)
1.39 christos 1558: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1559: #endif
1560: *q++ = *p--;
1561: }
1562: /*
1563: * Last hop goes to final destination.
1564: */
1565: *q = ip_srcrt.dst;
1566: #ifdef DIAGNOSTIC
1567: if (ipprintfs)
1.39 christos 1568: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1569: #endif
1570: return (m);
1571: }
1572:
1573: /*
1574: * Strip out IP options, at higher
1575: * level protocol in the kernel.
1576: * Second argument is buffer to which options
1577: * will be moved, and return value is their length.
1578: * XXX should be deleted; last arg currently ignored.
1579: */
1.8 mycroft 1580: void
1.1 cgd 1581: ip_stripoptions(m, mopt)
1.109 augustss 1582: struct mbuf *m;
1.1 cgd 1583: struct mbuf *mopt;
1584: {
1.109 augustss 1585: int i;
1.1 cgd 1586: struct ip *ip = mtod(m, struct ip *);
1.109 augustss 1587: caddr_t opts;
1.1 cgd 1588: int olen;
1589:
1.79 mycroft 1590: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1591: opts = (caddr_t)(ip + 1);
1592: i = m->m_len - (sizeof (struct ip) + olen);
1593: bcopy(opts + olen, opts, (unsigned)i);
1594: m->m_len -= olen;
1595: if (m->m_flags & M_PKTHDR)
1596: m->m_pkthdr.len -= olen;
1.155 itojun 1597: ip->ip_len = htons(ntohs(ip->ip_len) - olen);
1.79 mycroft 1598: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1599: }
1600:
1.139 matt 1601: const int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1602: 0, 0, 0, 0,
1603: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1604: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1605: EMSGSIZE, EHOSTUNREACH, 0, 0,
1606: 0, 0, 0, 0,
1607: ENOPROTOOPT
1608: };
1609:
1610: /*
1611: * Forward a packet. If some error occurs return the sender
1612: * an icmp packet. Note we can't always generate a meaningful
1613: * icmp message because icmp doesn't have a large enough repertoire
1614: * of codes and types.
1615: *
1616: * If not forwarding, just drop the packet. This could be confusing
1617: * if ipforwarding was zero but some routing protocol was advancing
1618: * us as a gateway to somewhere. However, we must let the routing
1619: * protocol deal with that.
1620: *
1621: * The srcrt parameter indicates whether the packet is being forwarded
1622: * via a source route.
1623: */
1.13 mycroft 1624: void
1.1 cgd 1625: ip_forward(m, srcrt)
1626: struct mbuf *m;
1627: int srcrt;
1628: {
1.109 augustss 1629: struct ip *ip = mtod(m, struct ip *);
1630: struct sockaddr_in *sin;
1631: struct rtentry *rt;
1.28 christos 1632: int error, type = 0, code = 0;
1.1 cgd 1633: struct mbuf *mcopy;
1.13 mycroft 1634: n_long dest;
1635: struct ifnet *destifp;
1.173 jonathan 1636: #if defined(IPSEC) || defined(FAST_IPSEC)
1.89 itojun 1637: struct ifnet dummyifp;
1638: #endif
1.164 matt 1639:
1640: /*
1641: * We are now in the output path.
1642: */
1643: MCLAIM(m, &ip_tx_mowner);
1.135 thorpej 1644:
1645: /*
1646: * Clear any in-bound checksum flags for this packet.
1647: */
1648: m->m_pkthdr.csum_flags = 0;
1.1 cgd 1649:
1.13 mycroft 1650: dest = 0;
1.1 cgd 1651: #ifdef DIAGNOSTIC
1652: if (ipprintfs)
1.70 thorpej 1653: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1654: ntohl(ip->ip_src.s_addr),
1655: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1656: #endif
1.93 sommerfe 1657: if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1.1 cgd 1658: ipstat.ips_cantforward++;
1659: m_freem(m);
1660: return;
1661: }
1662: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1663: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1664: return;
1665: }
1666: ip->ip_ttl -= IPTTLDEC;
1667:
1.19 mycroft 1668: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1669: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1670: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1671: if (ipforward_rt.ro_rt) {
1672: RTFREE(ipforward_rt.ro_rt);
1673: ipforward_rt.ro_rt = 0;
1674: }
1675: sin->sin_family = AF_INET;
1.35 mycroft 1676: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1677: sin->sin_addr = ip->ip_dst;
1678:
1679: rtalloc(&ipforward_rt);
1680: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1681: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1682: return;
1683: }
1684: rt = ipforward_rt.ro_rt;
1685: }
1686:
1687: /*
1.34 mycroft 1688: * Save at most 68 bytes of the packet in case
1.1 cgd 1689: * we need to generate an ICMP message to the src.
1.119 itojun 1690: * Pullup to avoid sharing mbuf cluster between m and mcopy.
1.1 cgd 1691: */
1.155 itojun 1692: mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1.119 itojun 1693: if (mcopy)
1694: mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1.1 cgd 1695:
1696: /*
1697: * If forwarding packet using same interface that it came in on,
1698: * perhaps should send a redirect to sender to shortcut a hop.
1699: * Only send redirect if source is sending directly to us,
1700: * and if packet was not source routed (or has any options).
1701: * Also, don't send redirect if forwarding using a default route
1702: * or a route modified by a redirect.
1703: */
1704: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1705: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1706: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1707: ipsendredirects && !srcrt) {
1.19 mycroft 1708: if (rt->rt_ifa &&
1709: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1710: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1711: if (rt->rt_flags & RTF_GATEWAY)
1712: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1713: else
1714: dest = ip->ip_dst.s_addr;
1715: /*
1716: * Router requirements says to only send host
1717: * redirects.
1718: */
1719: type = ICMP_REDIRECT;
1720: code = ICMP_REDIRECT_HOST;
1.1 cgd 1721: #ifdef DIAGNOSTIC
1.77 thorpej 1722: if (ipprintfs)
1723: printf("redirect (%d) to %x\n", code,
1724: (u_int32_t)dest);
1.1 cgd 1725: #endif
1726: }
1727: }
1728:
1.27 thorpej 1729: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1.173 jonathan 1730: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1.174 itojun 1731: (struct ip_moptions *)NULL, (struct socket *)NULL);
1.173 jonathan 1732:
1.1 cgd 1733: if (error)
1734: ipstat.ips_cantforward++;
1735: else {
1736: ipstat.ips_forward++;
1737: if (type)
1738: ipstat.ips_redirectsent++;
1739: else {
1.63 matt 1740: if (mcopy) {
1741: #ifdef GATEWAY
1.64 thorpej 1742: if (mcopy->m_flags & M_CANFASTFWD)
1743: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1744: #endif
1.1 cgd 1745: m_freem(mcopy);
1.63 matt 1746: }
1.1 cgd 1747: return;
1748: }
1749: }
1750: if (mcopy == NULL)
1751: return;
1.13 mycroft 1752: destifp = NULL;
1753:
1.1 cgd 1754: switch (error) {
1755:
1756: case 0: /* forwarded, but need redirect */
1757: /* type, code set above */
1758: break;
1759:
1760: case ENETUNREACH: /* shouldn't happen, checked above */
1761: case EHOSTUNREACH:
1762: case ENETDOWN:
1763: case EHOSTDOWN:
1764: default:
1765: type = ICMP_UNREACH;
1766: code = ICMP_UNREACH_HOST;
1767: break;
1768:
1769: case EMSGSIZE:
1770: type = ICMP_UNREACH;
1771: code = ICMP_UNREACH_NEEDFRAG;
1.173 jonathan 1772: #if !defined(IPSEC) && !defined(FAST_IPSEC)
1.13 mycroft 1773: if (ipforward_rt.ro_rt)
1774: destifp = ipforward_rt.ro_rt->rt_ifp;
1.89 itojun 1775: #else
1776: /*
1777: * If the packet is routed over IPsec tunnel, tell the
1778: * originator the tunnel MTU.
1779: * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1780: * XXX quickhack!!!
1781: */
1782: if (ipforward_rt.ro_rt) {
1783: struct secpolicy *sp;
1784: int ipsecerror;
1.95 itojun 1785: size_t ipsechdr;
1.89 itojun 1786: struct route *ro;
1787:
1788: sp = ipsec4_getpolicybyaddr(mcopy,
1.170 itojun 1789: IPSEC_DIR_OUTBOUND, IP_FORWARDING,
1790: &ipsecerror);
1.89 itojun 1791:
1792: if (sp == NULL)
1793: destifp = ipforward_rt.ro_rt->rt_ifp;
1794: else {
1795: /* count IPsec header size */
1.95 itojun 1796: ipsechdr = ipsec4_hdrsiz(mcopy,
1.170 itojun 1797: IPSEC_DIR_OUTBOUND, NULL);
1.89 itojun 1798:
1799: /*
1800: * find the correct route for outer IPv4
1801: * header, compute tunnel MTU.
1802: *
1803: * XXX BUG ALERT
1804: * The "dummyifp" code relies upon the fact
1805: * that icmp_error() touches only ifp->if_mtu.
1806: */
1807: /*XXX*/
1808: destifp = NULL;
1809: if (sp->req != NULL
1.95 itojun 1810: && sp->req->sav != NULL
1811: && sp->req->sav->sah != NULL) {
1812: ro = &sp->req->sav->sah->sa_route;
1.89 itojun 1813: if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1814: dummyifp.if_mtu =
1.151 itojun 1815: ro->ro_rt->rt_rmx.rmx_mtu ?
1816: ro->ro_rt->rt_rmx.rmx_mtu :
1.89 itojun 1817: ro->ro_rt->rt_ifp->if_mtu;
1818: dummyifp.if_mtu -= ipsechdr;
1819: destifp = &dummyifp;
1820: }
1821: }
1822:
1.173 jonathan 1823: #ifdef IPSEC
1.89 itojun 1824: key_freesp(sp);
1.173 jonathan 1825: #else
1826: KEY_FREESP(&sp);
1827: #endif
1.89 itojun 1828: }
1829: }
1830: #endif /*IPSEC*/
1.1 cgd 1831: ipstat.ips_cantfrag++;
1832: break;
1833:
1834: case ENOBUFS:
1.143 itojun 1835: #if 1
1836: /*
1837: * a router should not generate ICMP_SOURCEQUENCH as
1838: * required in RFC1812 Requirements for IP Version 4 Routers.
1839: * source quench could be a big problem under DoS attacks,
1.149 wiz 1840: * or if the underlying interface is rate-limited.
1.143 itojun 1841: */
1842: if (mcopy)
1843: m_freem(mcopy);
1844: return;
1845: #else
1.1 cgd 1846: type = ICMP_SOURCEQUENCH;
1847: code = 0;
1848: break;
1.143 itojun 1849: #endif
1.1 cgd 1850: }
1.13 mycroft 1851: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1852: }
1853:
1854: void
1855: ip_savecontrol(inp, mp, ip, m)
1.109 augustss 1856: struct inpcb *inp;
1857: struct mbuf **mp;
1858: struct ip *ip;
1859: struct mbuf *m;
1.44 thorpej 1860: {
1861:
1862: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1863: struct timeval tv;
1864:
1865: microtime(&tv);
1866: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1867: SCM_TIMESTAMP, SOL_SOCKET);
1868: if (*mp)
1869: mp = &(*mp)->m_next;
1870: }
1871: if (inp->inp_flags & INP_RECVDSTADDR) {
1872: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1873: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1874: if (*mp)
1875: mp = &(*mp)->m_next;
1876: }
1877: #ifdef notyet
1878: /*
1879: * XXX
1880: * Moving these out of udp_input() made them even more broken
1881: * than they already were.
1882: * - fenner@parc.xerox.com
1883: */
1884: /* options were tossed already */
1885: if (inp->inp_flags & INP_RECVOPTS) {
1886: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1887: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1888: if (*mp)
1889: mp = &(*mp)->m_next;
1890: }
1891: /* ip_srcroute doesn't do what we want here, need to fix */
1892: if (inp->inp_flags & INP_RECVRETOPTS) {
1893: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1894: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1895: if (*mp)
1896: mp = &(*mp)->m_next;
1897: }
1898: #endif
1899: if (inp->inp_flags & INP_RECVIF) {
1900: struct sockaddr_dl sdl;
1901:
1902: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1903: sdl.sdl_family = AF_LINK;
1904: sdl.sdl_index = m->m_pkthdr.rcvif ?
1905: m->m_pkthdr.rcvif->if_index : 0;
1906: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1907: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1908: IP_RECVIF, IPPROTO_IP);
1909: if (*mp)
1910: mp = &(*mp)->m_next;
1911: }
1.13 mycroft 1912: }
1913:
1914: int
1915: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1916: int *name;
1917: u_int namelen;
1918: void *oldp;
1919: size_t *oldlenp;
1920: void *newp;
1921: size_t newlen;
1922: {
1.88 sommerfe 1923: extern int subnetsarelocal, hostzeroisbroadcast;
1.52 thorpej 1924:
1.54 lukem 1925: int error, old;
1926:
1.180 jonathan 1927: /* All sysctl names (except ifq.*) at this level are terminal. */
1928: if ((namelen != 1) && !(namelen == 2 && name[0] == IPCTL_IFQ))
1929: return (ENOTDIR);
1.13 mycroft 1930:
1931: switch (name[0]) {
1932: case IPCTL_FORWARDING:
1933: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1934: case IPCTL_SENDREDIRECTS:
1935: return (sysctl_int(oldp, oldlenp, newp, newlen,
1936: &ipsendredirects));
1937: case IPCTL_DEFTTL:
1938: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1939: #ifdef notyet
1940: case IPCTL_DEFMTU:
1941: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1942: #endif
1.26 thorpej 1943: case IPCTL_FORWSRCRT:
1.47 cjs 1944: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1945: if (securelevel > 0)
1.46 cjs 1946: return (sysctl_rdint(oldp, oldlenp, newp,
1947: ip_forwsrcrt));
1948: else
1949: return (sysctl_int(oldp, oldlenp, newp, newlen,
1950: &ip_forwsrcrt));
1.27 thorpej 1951: case IPCTL_DIRECTEDBCAST:
1952: return (sysctl_int(oldp, oldlenp, newp, newlen,
1953: &ip_directedbcast));
1.47 cjs 1954: case IPCTL_ALLOWSRCRT:
1955: return (sysctl_int(oldp, oldlenp, newp, newlen,
1956: &ip_allowsrcrt));
1.52 thorpej 1957: case IPCTL_SUBNETSARELOCAL:
1958: return (sysctl_int(oldp, oldlenp, newp, newlen,
1959: &subnetsarelocal));
1.53 kml 1960: case IPCTL_MTUDISC:
1.60 kml 1961: error = sysctl_int(oldp, oldlenp, newp, newlen,
1962: &ip_mtudisc);
1.163 itojun 1963: if (error == 0 && ip_mtudisc == 0)
1964: rt_timer_queue_remove_all(ip_mtudisc_timeout_q, TRUE);
1.60 kml 1965: return error;
1.54 lukem 1966: case IPCTL_ANONPORTMIN:
1967: old = anonportmin;
1968: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1.118 itojun 1969: if (anonportmin >= anonportmax || anonportmin < 0
1970: || anonportmin > 65535
1.54 lukem 1971: #ifndef IPNOPRIVPORTS
1972: || anonportmin < IPPORT_RESERVED
1973: #endif
1974: ) {
1975: anonportmin = old;
1976: return (EINVAL);
1977: }
1978: return (error);
1979: case IPCTL_ANONPORTMAX:
1980: old = anonportmax;
1981: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1.118 itojun 1982: if (anonportmin >= anonportmax || anonportmax < 0
1983: || anonportmax > 65535
1.54 lukem 1984: #ifndef IPNOPRIVPORTS
1985: || anonportmax < IPPORT_RESERVED
1986: #endif
1987: ) {
1988: anonportmax = old;
1989: return (EINVAL);
1990: }
1.60 kml 1991: return (error);
1992: case IPCTL_MTUDISCTIMEOUT:
1.158 itojun 1993: old = ip_mtudisc_timeout;
1.60 kml 1994: error = sysctl_int(oldp, oldlenp, newp, newlen,
1995: &ip_mtudisc_timeout);
1.158 itojun 1996: if (ip_mtudisc_timeout < 0) {
1997: ip_mtudisc_timeout = old;
1.156 itojun 1998: return (EINVAL);
1.158 itojun 1999: }
1.163 itojun 2000: if (error == 0)
1.162 itojun 2001: rt_timer_queue_change(ip_mtudisc_timeout_q,
2002: ip_mtudisc_timeout);
1.54 lukem 2003: return (error);
1.65 matt 2004: #ifdef GATEWAY
2005: case IPCTL_MAXFLOWS:
1.67 thorpej 2006: {
2007: int s;
2008:
1.65 matt 2009: error = sysctl_int(oldp, oldlenp, newp, newlen,
2010: &ip_maxflows);
1.67 thorpej 2011: s = splsoftnet();
1.65 matt 2012: ipflow_reap(0);
1.67 thorpej 2013: splx(s);
1.65 matt 2014: return (error);
1.67 thorpej 2015: }
1.89 itojun 2016: #endif
1.90 itojun 2017: case IPCTL_HOSTZEROBROADCAST:
2018: return (sysctl_int(oldp, oldlenp, newp, newlen,
2019: &hostzeroisbroadcast));
1.89 itojun 2020: #if NGIF > 0
2021: case IPCTL_GIF_TTL:
1.157 itojun 2022: return (sysctl_int(oldp, oldlenp, newp, newlen,
1.90 itojun 2023: &ip_gif_ttl));
1.144 martin 2024: #endif
2025:
2026: #if NGRE > 0
2027: case IPCTL_GRE_TTL:
1.157 itojun 2028: return (sysctl_int(oldp, oldlenp, newp, newlen,
1.144 martin 2029: &ip_gre_ttl));
1.117 tron 2030: #endif
2031:
2032: #ifndef IPNOPRIVPORTS
2033: case IPCTL_LOWPORTMIN:
2034: old = lowportmin;
2035: error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmin);
2036: if (lowportmin >= lowportmax
2037: || lowportmin > IPPORT_RESERVEDMAX
2038: || lowportmin < IPPORT_RESERVEDMIN
2039: ) {
2040: lowportmin = old;
2041: return (EINVAL);
2042: }
2043: return (error);
2044: case IPCTL_LOWPORTMAX:
2045: old = lowportmax;
2046: error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmax);
2047: if (lowportmin >= lowportmax
2048: || lowportmax > IPPORT_RESERVEDMAX
2049: || lowportmax < IPPORT_RESERVEDMIN
2050: ) {
2051: lowportmax = old;
2052: return (EINVAL);
2053: }
2054: return (error);
1.65 matt 2055: #endif
1.131 itojun 2056:
2057: case IPCTL_MAXFRAGPACKETS:
2058: return (sysctl_int(oldp, oldlenp, newp, newlen,
2059: &ip_maxfragpackets));
1.88 sommerfe 2060:
1.165 christos 2061: case IPCTL_CHECKINTERFACE:
2062: return (sysctl_int(oldp, oldlenp, newp, newlen,
2063: &ip_checkinterface));
1.182 itojun 2064:
1.180 jonathan 2065: case IPCTL_IFQ:
1.182 itojun 2066: return (sysctl_ifq(name + 1, namelen - 1, oldp, oldlenp,
2067: newp, newlen, &ipintrq));
1.180 jonathan 2068:
1.13 mycroft 2069: default:
2070: return (EOPNOTSUPP);
2071: }
2072: /* NOTREACHED */
1.1 cgd 2073: }
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