Annotation of src/sys/netinet/ip_input.c, Revision 1.178
1.178 ! itojun 1: /* $NetBSD: ip_input.c,v 1.177 2003/09/06 00:24:54 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>
1.178 ! itojun 101: __KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.177 2003/09/06 00:24:54 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 */
1.22 mycroft 222: struct in_ifaddrhead in_ifaddr;
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;
1.75 thorpej 229:
1.121 thorpej 230: #ifdef PFIL_HOOKS
231: struct pfil_head inet_pfil_hook;
232: #endif
233:
1.63 matt 234: struct ipqhead ipq;
1.75 thorpej 235: int ipq_locked;
1.131 itojun 236: int ip_nfragpackets = 0;
1.133 itojun 237: int ip_maxfragpackets = 200;
1.75 thorpej 238:
239: static __inline int ipq_lock_try __P((void));
240: static __inline void ipq_unlock __P((void));
241:
242: static __inline int
243: ipq_lock_try()
244: {
245: int s;
246:
1.132 thorpej 247: /*
1.149 wiz 248: * Use splvm() -- we're blocking things that would cause
1.132 thorpej 249: * mbuf allocation.
250: */
251: s = splvm();
1.75 thorpej 252: if (ipq_locked) {
253: splx(s);
254: return (0);
255: }
256: ipq_locked = 1;
257: splx(s);
258: return (1);
259: }
260:
261: static __inline void
262: ipq_unlock()
263: {
264: int s;
265:
1.132 thorpej 266: s = splvm();
1.75 thorpej 267: ipq_locked = 0;
268: splx(s);
269: }
270:
271: #ifdef DIAGNOSTIC
272: #define IPQ_LOCK() \
273: do { \
274: if (ipq_lock_try() == 0) { \
275: printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
276: panic("ipq_lock"); \
277: } \
1.159 perry 278: } while (/*CONSTCOND*/ 0)
1.75 thorpej 279: #define IPQ_LOCK_CHECK() \
280: do { \
281: if (ipq_locked == 0) { \
282: printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
283: panic("ipq lock check"); \
284: } \
1.159 perry 285: } while (/*CONSTCOND*/ 0)
1.75 thorpej 286: #else
287: #define IPQ_LOCK() (void) ipq_lock_try()
288: #define IPQ_LOCK_CHECK() /* nothing */
289: #endif
290:
291: #define IPQ_UNLOCK() ipq_unlock()
1.1 cgd 292:
1.166 matt 293: struct pool inmulti_pool;
1.72 thorpej 294: struct pool ipqent_pool;
295:
1.135 thorpej 296: #ifdef INET_CSUM_COUNTERS
297: #include <sys/device.h>
298:
299: struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
300: NULL, "inet", "hwcsum bad");
301: struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
302: NULL, "inet", "hwcsum ok");
303: struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
304: NULL, "inet", "swcsum");
305:
306: #define INET_CSUM_COUNTER_INCR(ev) (ev)->ev_count++
307:
308: #else
309:
310: #define INET_CSUM_COUNTER_INCR(ev) /* nothing */
311:
312: #endif /* INET_CSUM_COUNTERS */
313:
1.1 cgd 314: /*
315: * We need to save the IP options in case a protocol wants to respond
316: * to an incoming packet over the same route if the packet got here
317: * using IP source routing. This allows connection establishment and
318: * maintenance when the remote end is on a network that is not known
319: * to us.
320: */
321: int ip_nhops = 0;
322: static struct ip_srcrt {
323: struct in_addr dst; /* final destination */
324: char nop; /* one NOP to align */
325: char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
326: struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
327: } ip_srcrt;
328:
1.13 mycroft 329: static void save_rte __P((u_char *, struct in_addr));
1.35 mycroft 330:
1.164 matt 331: #ifdef MBUFTRACE
332: struct mowner ip_rx_mowner = { "internet", "rx" };
333: struct mowner ip_tx_mowner = { "internet", "tx" };
334: #endif
335:
1.1 cgd 336: /*
337: * IP initialization: fill in IP protocol switch table.
338: * All protocols not implemented in kernel go to raw IP protocol handler.
339: */
1.8 mycroft 340: void
1.1 cgd 341: ip_init()
342: {
1.109 augustss 343: struct protosw *pr;
344: int i;
1.1 cgd 345:
1.166 matt 346: pool_init(&inmulti_pool, sizeof(struct in_multi), 0, 0, 0, "inmltpl",
347: NULL);
1.72 thorpej 348: pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
1.146 thorpej 349: NULL);
1.72 thorpej 350:
1.1 cgd 351: pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
352: if (pr == 0)
353: panic("ip_init");
354: for (i = 0; i < IPPROTO_MAX; i++)
355: ip_protox[i] = pr - inetsw;
356: for (pr = inetdomain.dom_protosw;
357: pr < inetdomain.dom_protoswNPROTOSW; pr++)
358: if (pr->pr_domain->dom_family == PF_INET &&
359: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
360: ip_protox[pr->pr_protocol] = pr - inetsw;
1.25 cgd 361: LIST_INIT(&ipq);
1.1 cgd 362: ipintrq.ifq_maxlen = ipqmaxlen;
1.22 mycroft 363: TAILQ_INIT(&in_ifaddr);
1.120 ad 364: in_ifaddrhashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IFADDR,
365: M_WAITOK, &in_ifaddrhash);
1.166 matt 366: in_multihashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IPMADDR,
367: M_WAITOK, &in_multihash);
1.160 itojun 368: ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
1.73 thorpej 369: #ifdef GATEWAY
370: ipflow_init();
371: #endif
1.121 thorpej 372:
373: #ifdef PFIL_HOOKS
374: /* Register our Packet Filter hook. */
1.126 thorpej 375: inet_pfil_hook.ph_type = PFIL_TYPE_AF;
376: inet_pfil_hook.ph_af = AF_INET;
1.121 thorpej 377: i = pfil_head_register(&inet_pfil_hook);
378: if (i != 0)
379: printf("ip_init: WARNING: unable to register pfil hook, "
380: "error %d\n", i);
381: #endif /* PFIL_HOOKS */
1.135 thorpej 382:
383: #ifdef INET_CSUM_COUNTERS
384: evcnt_attach_static(&ip_hwcsum_bad);
385: evcnt_attach_static(&ip_hwcsum_ok);
386: evcnt_attach_static(&ip_swcsum);
387: #endif /* INET_CSUM_COUNTERS */
1.164 matt 388:
389: #ifdef MBUFTRACE
390: MOWNER_ATTACH(&ip_tx_mowner);
391: MOWNER_ATTACH(&ip_rx_mowner);
392: #endif /* MBUFTRACE */
1.1 cgd 393: }
394:
395: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
396: struct route ipforward_rt;
397:
398: /*
1.89 itojun 399: * IP software interrupt routine
400: */
401: void
402: ipintr()
403: {
404: int s;
405: struct mbuf *m;
406:
407: while (1) {
1.132 thorpej 408: s = splnet();
1.89 itojun 409: IF_DEQUEUE(&ipintrq, m);
410: splx(s);
411: if (m == 0)
412: return;
1.164 matt 413: MCLAIM(m, &ip_rx_mowner);
1.89 itojun 414: ip_input(m);
415: }
416: }
417:
418: /*
1.1 cgd 419: * Ip input routine. Checksum and byte swap header. If fragmented
420: * try to reassemble. Process options. Pass to next level.
421: */
1.8 mycroft 422: void
1.89 itojun 423: ip_input(struct mbuf *m)
1.1 cgd 424: {
1.109 augustss 425: struct ip *ip = NULL;
426: struct ipq *fp;
427: struct in_ifaddr *ia;
428: struct ifaddr *ifa;
1.25 cgd 429: struct ipqent *ipqe;
1.89 itojun 430: int hlen = 0, mff, len;
1.100 itojun 431: int downmatch;
1.165 christos 432: int checkif;
1.169 itojun 433: int srcrt = 0;
1.173 jonathan 434: #ifdef FAST_IPSEC
435: struct m_tag *mtag;
436: struct tdb_ident *tdbi;
437: struct secpolicy *sp;
438: int s, error;
439: #endif /* FAST_IPSEC */
1.1 cgd 440:
1.164 matt 441: MCLAIM(m, &ip_rx_mowner);
1.1 cgd 442: #ifdef DIAGNOSTIC
443: if ((m->m_flags & M_PKTHDR) == 0)
444: panic("ipintr no HDR");
445: #endif
1.89 itojun 446: #ifdef IPSEC
447: /*
448: * should the inner packet be considered authentic?
449: * see comment in ah4_input().
450: */
451: if (m) {
452: m->m_flags &= ~M_AUTHIPHDR;
453: m->m_flags &= ~M_AUTHIPDGM;
454: }
455: #endif
1.164 matt 456:
1.1 cgd 457: /*
458: * If no IP addresses have been set yet but the interfaces
459: * are receiving, can't do anything with incoming packets yet.
460: */
1.140 matt 461: if (TAILQ_FIRST(&in_ifaddr) == 0)
1.1 cgd 462: goto bad;
463: ipstat.ips_total++;
1.154 thorpej 464: /*
465: * If the IP header is not aligned, slurp it up into a new
466: * mbuf with space for link headers, in the event we forward
467: * it. Otherwise, if it is aligned, make sure the entire
468: * base IP header is in the first mbuf of the chain.
469: */
470: if (IP_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) {
471: if ((m = m_copyup(m, sizeof(struct ip),
472: (max_linkhdr + 3) & ~3)) == NULL) {
473: /* XXXJRT new stat, please */
474: ipstat.ips_toosmall++;
475: return;
476: }
477: } else if (__predict_false(m->m_len < sizeof (struct ip))) {
478: if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
479: ipstat.ips_toosmall++;
480: return;
481: }
1.1 cgd 482: }
483: ip = mtod(m, struct ip *);
1.13 mycroft 484: if (ip->ip_v != IPVERSION) {
485: ipstat.ips_badvers++;
486: goto bad;
487: }
1.1 cgd 488: hlen = ip->ip_hl << 2;
489: if (hlen < sizeof(struct ip)) { /* minimum header length */
490: ipstat.ips_badhlen++;
491: goto bad;
492: }
493: if (hlen > m->m_len) {
494: if ((m = m_pullup(m, hlen)) == 0) {
495: ipstat.ips_badhlen++;
1.89 itojun 496: return;
1.1 cgd 497: }
498: ip = mtod(m, struct ip *);
499: }
1.98 thorpej 500:
1.85 hwr 501: /*
1.99 thorpej 502: * RFC1122: packets with a multicast source address are
1.98 thorpej 503: * not allowed.
1.85 hwr 504: */
505: if (IN_MULTICAST(ip->ip_src.s_addr)) {
1.130 itojun 506: ipstat.ips_badaddr++;
1.85 hwr 507: goto bad;
1.129 itojun 508: }
509:
510: /* 127/8 must not appear on wire - RFC1122 */
511: if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
512: (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
1.130 itojun 513: if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
514: ipstat.ips_badaddr++;
1.129 itojun 515: goto bad;
1.130 itojun 516: }
1.85 hwr 517: }
518:
1.135 thorpej 519: switch (m->m_pkthdr.csum_flags &
1.137 thorpej 520: ((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
1.135 thorpej 521: M_CSUM_IPv4_BAD)) {
522: case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
523: INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
524: goto badcsum;
525:
526: case M_CSUM_IPv4:
527: /* Checksum was okay. */
528: INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
529: break;
530:
531: default:
532: /* Must compute it ourselves. */
533: INET_CSUM_COUNTER_INCR(&ip_swcsum);
534: if (in_cksum(m, hlen) != 0)
535: goto bad;
536: break;
1.1 cgd 537: }
538:
1.121 thorpej 539: /* Retrieve the packet length. */
540: len = ntohs(ip->ip_len);
1.81 proff 541:
542: /*
543: * Check for additional length bogosity
544: */
1.84 proff 545: if (len < hlen) {
1.81 proff 546: ipstat.ips_badlen++;
547: goto bad;
548: }
1.1 cgd 549:
550: /*
551: * Check that the amount of data in the buffers
552: * is as at least much as the IP header would have us expect.
553: * Trim mbufs if longer than we expect.
554: * Drop packet if shorter than we expect.
555: */
1.35 mycroft 556: if (m->m_pkthdr.len < len) {
1.1 cgd 557: ipstat.ips_tooshort++;
558: goto bad;
559: }
1.35 mycroft 560: if (m->m_pkthdr.len > len) {
1.1 cgd 561: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 562: m->m_len = len;
563: m->m_pkthdr.len = len;
1.1 cgd 564: } else
1.35 mycroft 565: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 566: }
567:
1.94 itojun 568: #ifdef IPSEC
1.149 wiz 569: /* ipflow (IP fast forwarding) is not compatible with IPsec. */
1.94 itojun 570: m->m_flags &= ~M_CANFASTFWD;
571: #else
1.64 thorpej 572: /*
573: * Assume that we can create a fast-forward IP flow entry
574: * based on this packet.
575: */
576: m->m_flags |= M_CANFASTFWD;
1.94 itojun 577: #endif
1.64 thorpej 578:
1.36 mrg 579: #ifdef PFIL_HOOKS
1.33 mrg 580: /*
1.64 thorpej 581: * Run through list of hooks for input packets. If there are any
582: * filters which require that additional packets in the flow are
583: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
584: * Note that filters must _never_ set this flag, as another filter
585: * in the list may have previously cleared it.
1.33 mrg 586: */
1.127 itojun 587: /*
588: * let ipfilter look at packet on the wire,
589: * not the decapsulated packet.
590: */
591: #ifdef IPSEC
1.136 itojun 592: if (!ipsec_getnhist(m))
1.127 itojun 593: #else
594: if (1)
595: #endif
596: {
1.169 itojun 597: struct in_addr odst;
598:
599: odst = ip->ip_dst;
1.127 itojun 600: if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
1.168 itojun 601: PFIL_IN) != 0)
602: return;
1.127 itojun 603: if (m == NULL)
604: return;
605: ip = mtod(m, struct ip *);
1.142 darrenr 606: hlen = ip->ip_hl << 2;
1.169 itojun 607: srcrt = (odst.s_addr != ip->ip_dst.s_addr);
1.127 itojun 608: }
1.36 mrg 609: #endif /* PFIL_HOOKS */
1.123 thorpej 610:
611: #ifdef ALTQ
612: /* XXX Temporary until ALTQ is changed to use a pfil hook */
613: if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
614: /* packet dropped by traffic conditioner */
615: return;
616: }
617: #endif
1.121 thorpej 618:
619: /*
1.1 cgd 620: * Process options and, if not destined for us,
621: * ship it on. ip_dooptions returns 1 when an
622: * error was detected (causing an icmp message
623: * to be sent and the original packet to be freed).
624: */
625: ip_nhops = 0; /* for source routed packets */
626: if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.89 itojun 627: return;
1.1 cgd 628:
629: /*
1.165 christos 630: * Enable a consistency check between the destination address
631: * and the arrival interface for a unicast packet (the RFC 1122
632: * strong ES model) if IP forwarding is disabled and the packet
633: * is not locally generated.
634: *
635: * XXX - Checking also should be disabled if the destination
636: * address is ipnat'ed to a different interface.
637: *
638: * XXX - Checking is incompatible with IP aliases added
639: * to the loopback interface instead of the interface where
640: * the packets are received.
641: *
642: * XXX - We need to add a per ifaddr flag for this so that
643: * we get finer grain control.
644: */
645: checkif = ip_checkinterface && (ipforwarding == 0) &&
646: (m->m_pkthdr.rcvif != NULL) &&
647: ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0);
648:
649: /*
1.1 cgd 650: * Check our list of addresses, to see if the packet is for us.
1.100 itojun 651: *
652: * Traditional 4.4BSD did not consult IFF_UP at all.
653: * The behavior here is to treat addresses on !IFF_UP interface
654: * as not mine.
1.1 cgd 655: */
1.100 itojun 656: downmatch = 0;
1.140 matt 657: LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
1.97 itojun 658: if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
1.165 christos 659: if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif)
660: continue;
1.97 itojun 661: if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
662: break;
1.100 itojun 663: else
664: downmatch++;
1.97 itojun 665: }
666: }
1.86 thorpej 667: if (ia != NULL)
668: goto ours;
1.57 tls 669: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
1.140 matt 670: TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) {
671: if (ifa->ifa_addr->sa_family != AF_INET)
672: continue;
1.57 tls 673: ia = ifatoia(ifa);
1.35 mycroft 674: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
675: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 676: /*
677: * Look for all-0's host part (old broadcast addr),
678: * either for subnet or net.
679: */
680: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 681: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 682: goto ours;
1.57 tls 683: /*
684: * An interface with IP address zero accepts
685: * all packets that arrive on that interface.
686: */
687: if (in_nullhost(ia->ia_addr.sin_addr))
688: goto ours;
1.1 cgd 689: }
690: }
1.18 mycroft 691: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 692: struct in_multi *inm;
693: #ifdef MROUTING
694: extern struct socket *ip_mrouter;
1.10 brezak 695:
1.147 matt 696: if (M_READONLY(m)) {
1.10 brezak 697: if ((m = m_pullup(m, hlen)) == 0) {
698: ipstat.ips_toosmall++;
1.89 itojun 699: return;
1.10 brezak 700: }
701: ip = mtod(m, struct ip *);
702: }
1.4 hpeyerl 703:
704: if (ip_mrouter) {
705: /*
706: * If we are acting as a multicast router, all
707: * incoming multicast packets are passed to the
708: * kernel-level multicast forwarding function.
709: * The packet is returned (relatively) intact; if
710: * ip_mforward() returns a non-zero value, the packet
711: * must be discarded, else it may be accepted below.
712: *
713: * (The IP ident field is put in the same byte order
714: * as expected when ip_mforward() is called from
715: * ip_output().)
716: */
1.13 mycroft 717: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
718: ipstat.ips_cantforward++;
1.4 hpeyerl 719: m_freem(m);
1.89 itojun 720: return;
1.4 hpeyerl 721: }
722:
723: /*
724: * The process-level routing demon needs to receive
725: * all multicast IGMP packets, whether or not this
726: * host belongs to their destination groups.
727: */
728: if (ip->ip_p == IPPROTO_IGMP)
729: goto ours;
1.13 mycroft 730: ipstat.ips_forward++;
1.4 hpeyerl 731: }
732: #endif
733: /*
734: * See if we belong to the destination multicast group on the
735: * arrival interface.
736: */
737: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
738: if (inm == NULL) {
1.13 mycroft 739: ipstat.ips_cantforward++;
1.4 hpeyerl 740: m_freem(m);
1.89 itojun 741: return;
1.4 hpeyerl 742: }
743: goto ours;
744: }
1.19 mycroft 745: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 746: in_nullhost(ip->ip_dst))
1.1 cgd 747: goto ours;
748:
749: /*
750: * Not for us; forward if possible and desirable.
751: */
752: if (ipforwarding == 0) {
753: ipstat.ips_cantforward++;
754: m_freem(m);
1.100 itojun 755: } else {
756: /*
757: * If ip_dst matched any of my address on !IFF_UP interface,
758: * and there's no IFF_UP interface that matches ip_dst,
759: * send icmp unreach. Forwarding it will result in in-kernel
760: * forwarding loop till TTL goes to 0.
761: */
762: if (downmatch) {
763: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
764: ipstat.ips_cantforward++;
765: return;
766: }
1.145 itojun 767: #ifdef IPSEC
768: if (ipsec4_in_reject(m, NULL)) {
769: ipsecstat.in_polvio++;
770: goto bad;
771: }
772: #endif
1.173 jonathan 773: #ifdef FAST_IPSEC
774: mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
775: s = splsoftnet();
776: if (mtag != NULL) {
777: tdbi = (struct tdb_ident *)(mtag + 1);
778: sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
779: } else {
780: sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
781: IP_FORWARDING, &error);
782: }
783: if (sp == NULL) { /* NB: can happen if error */
784: splx(s);
785: /*XXX error stat???*/
786: DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
787: goto bad;
788: }
789:
790: /*
791: * Check security policy against packet attributes.
792: */
793: error = ipsec_in_reject(sp, m);
794: KEY_FREESP(&sp);
795: splx(s);
796: if (error) {
797: ipstat.ips_cantforward++;
798: goto bad;
799: }
800: #endif /* FAST_IPSEC */
1.145 itojun 801:
1.169 itojun 802: ip_forward(m, srcrt);
1.100 itojun 803: }
1.89 itojun 804: return;
1.1 cgd 805:
806: ours:
807: /*
808: * If offset or IP_MF are set, must reassemble.
809: * Otherwise, nothing need be done.
810: * (We could look in the reassembly queue to see
811: * if the packet was previously fragmented,
812: * but it's not worth the time; just let them time out.)
813: */
1.155 itojun 814: if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
815: if (M_READONLY(m)) {
816: if ((m = m_pullup(m, hlen)) == NULL) {
817: ipstat.ips_toosmall++;
818: goto bad;
819: }
820: ip = mtod(m, struct ip *);
821: }
822:
1.1 cgd 823: /*
824: * Look for queue of fragments
825: * of this datagram.
826: */
1.75 thorpej 827: IPQ_LOCK();
1.140 matt 828: LIST_FOREACH(fp, &ipq, ipq_q)
1.1 cgd 829: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 830: in_hosteq(ip->ip_src, fp->ipq_src) &&
831: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 832: ip->ip_p == fp->ipq_p)
833: goto found;
834: fp = 0;
835: found:
836:
837: /*
838: * Adjust ip_len to not reflect header,
1.25 cgd 839: * set ipqe_mff if more fragments are expected,
1.1 cgd 840: * convert offset of this to bytes.
841: */
1.155 itojun 842: ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
843: mff = (ip->ip_off & htons(IP_MF)) != 0;
1.25 cgd 844: if (mff) {
1.16 cgd 845: /*
846: * Make sure that fragments have a data length
847: * that's a non-zero multiple of 8 bytes.
848: */
1.155 itojun 849: if (ntohs(ip->ip_len) == 0 ||
850: (ntohs(ip->ip_len) & 0x7) != 0) {
1.16 cgd 851: ipstat.ips_badfrags++;
1.75 thorpej 852: IPQ_UNLOCK();
1.16 cgd 853: goto bad;
854: }
855: }
1.155 itojun 856: ip->ip_off = htons((ntohs(ip->ip_off) & IP_OFFMASK) << 3);
1.1 cgd 857:
858: /*
859: * If datagram marked as having more fragments
860: * or if this is not the first fragment,
861: * attempt reassembly; if it succeeds, proceed.
862: */
1.155 itojun 863: if (mff || ip->ip_off != htons(0)) {
1.1 cgd 864: ipstat.ips_fragments++;
1.72 thorpej 865: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 866: if (ipqe == NULL) {
867: ipstat.ips_rcvmemdrop++;
1.75 thorpej 868: IPQ_UNLOCK();
1.25 cgd 869: goto bad;
870: }
871: ipqe->ipqe_mff = mff;
1.50 thorpej 872: ipqe->ipqe_m = m;
1.25 cgd 873: ipqe->ipqe_ip = ip;
1.50 thorpej 874: m = ip_reass(ipqe, fp);
1.75 thorpej 875: if (m == 0) {
876: IPQ_UNLOCK();
1.89 itojun 877: return;
1.75 thorpej 878: }
1.13 mycroft 879: ipstat.ips_reassembled++;
1.50 thorpej 880: ip = mtod(m, struct ip *);
1.74 thorpej 881: hlen = ip->ip_hl << 2;
1.155 itojun 882: ip->ip_len = htons(ntohs(ip->ip_len) + hlen);
1.1 cgd 883: } else
884: if (fp)
885: ip_freef(fp);
1.75 thorpej 886: IPQ_UNLOCK();
1.79 mycroft 887: }
1.128 itojun 888:
1.173 jonathan 889: #if defined(IPSEC)
1.128 itojun 890: /*
891: * enforce IPsec policy checking if we are seeing last header.
892: * note that we do not visit this with protocols with pcb layer
893: * code - like udp/tcp/raw ip.
894: */
895: if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
896: ipsec4_in_reject(m, NULL)) {
897: ipsecstat.in_polvio++;
898: goto bad;
899: }
900: #endif
1.173 jonathan 901: #if FAST_IPSEC
902: /*
903: * enforce IPsec policy checking if we are seeing last header.
904: * note that we do not visit this with protocols with pcb layer
905: * code - like udp/tcp/raw ip.
906: */
907: if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
908: /*
909: * Check if the packet has already had IPsec processing
910: * done. If so, then just pass it along. This tag gets
911: * set during AH, ESP, etc. input handling, before the
912: * packet is returned to the ip input queue for delivery.
913: */
914: mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
915: s = splsoftnet();
916: if (mtag != NULL) {
917: tdbi = (struct tdb_ident *)(mtag + 1);
918: sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
919: } else {
920: sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
921: IP_FORWARDING, &error);
922: }
923: if (sp != NULL) {
924: /*
925: * Check security policy against packet attributes.
926: */
927: error = ipsec_in_reject(sp, m);
928: KEY_FREESP(&sp);
929: } else {
930: /* XXX error stat??? */
931: error = EINVAL;
932: DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
933: goto bad;
934: }
935: splx(s);
936: if (error)
937: goto bad;
938: }
939: #endif /* FAST_IPSEC */
1.1 cgd 940:
941: /*
942: * Switch out to protocol's input routine.
943: */
1.82 aidan 944: #if IFA_STATS
1.122 itojun 945: if (ia && ip)
1.155 itojun 946: ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
1.82 aidan 947: #endif
1.1 cgd 948: ipstat.ips_delivered++;
1.89 itojun 949: {
950: int off = hlen, nh = ip->ip_p;
951:
952: (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
953: return;
954: }
1.1 cgd 955: bad:
956: m_freem(m);
1.135 thorpej 957: return;
958:
959: badcsum:
960: ipstat.ips_badsum++;
961: m_freem(m);
1.1 cgd 962: }
963:
964: /*
965: * Take incoming datagram fragment and try to
966: * reassemble it into whole datagram. If a chain for
967: * reassembly of this datagram already exists, then it
968: * is given as fp; otherwise have to make a chain.
969: */
1.50 thorpej 970: struct mbuf *
1.25 cgd 971: ip_reass(ipqe, fp)
1.109 augustss 972: struct ipqent *ipqe;
973: struct ipq *fp;
1.1 cgd 974: {
1.109 augustss 975: struct mbuf *m = ipqe->ipqe_m;
976: struct ipqent *nq, *p, *q;
1.25 cgd 977: struct ip *ip;
1.1 cgd 978: struct mbuf *t;
1.25 cgd 979: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 980: int i, next;
981:
1.75 thorpej 982: IPQ_LOCK_CHECK();
983:
1.1 cgd 984: /*
985: * Presence of header sizes in mbufs
986: * would confuse code below.
987: */
988: m->m_data += hlen;
989: m->m_len -= hlen;
990:
991: /*
992: * If first fragment to arrive, create a reassembly queue.
993: */
994: if (fp == 0) {
1.131 itojun 995: /*
996: * Enforce upper bound on number of fragmented packets
997: * for which we attempt reassembly;
998: * If maxfrag is 0, never accept fragments.
999: * If maxfrag is -1, accept all fragments without limitation.
1000: */
1001: if (ip_maxfragpackets < 0)
1002: ;
1003: else if (ip_nfragpackets >= ip_maxfragpackets)
1004: goto dropfrag;
1005: ip_nfragpackets++;
1.50 thorpej 1006: MALLOC(fp, struct ipq *, sizeof (struct ipq),
1007: M_FTABLE, M_NOWAIT);
1008: if (fp == NULL)
1.1 cgd 1009: goto dropfrag;
1.25 cgd 1010: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 1011: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 1012: fp->ipq_p = ipqe->ipqe_ip->ip_p;
1013: fp->ipq_id = ipqe->ipqe_ip->ip_id;
1.148 matt 1014: TAILQ_INIT(&fp->ipq_fragq);
1.25 cgd 1015: fp->ipq_src = ipqe->ipqe_ip->ip_src;
1016: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
1017: p = NULL;
1.1 cgd 1018: goto insert;
1019: }
1020:
1021: /*
1022: * Find a segment which begins after this one does.
1023: */
1.148 matt 1024: for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
1025: p = q, q = TAILQ_NEXT(q, ipqe_q))
1.155 itojun 1026: if (ntohs(q->ipqe_ip->ip_off) > ntohs(ipqe->ipqe_ip->ip_off))
1.1 cgd 1027: break;
1028:
1029: /*
1030: * If there is a preceding segment, it may provide some of
1031: * our data already. If so, drop the data from the incoming
1032: * segment. If it provides all of our data, drop us.
1033: */
1.25 cgd 1034: if (p != NULL) {
1.155 itojun 1035: i = ntohs(p->ipqe_ip->ip_off) + ntohs(p->ipqe_ip->ip_len) -
1036: ntohs(ipqe->ipqe_ip->ip_off);
1.1 cgd 1037: if (i > 0) {
1.155 itojun 1038: if (i >= ntohs(ipqe->ipqe_ip->ip_len))
1.1 cgd 1039: goto dropfrag;
1.50 thorpej 1040: m_adj(ipqe->ipqe_m, i);
1.155 itojun 1041: ipqe->ipqe_ip->ip_off =
1042: htons(ntohs(ipqe->ipqe_ip->ip_off) + i);
1043: ipqe->ipqe_ip->ip_len =
1044: htons(ntohs(ipqe->ipqe_ip->ip_len) - i);
1.1 cgd 1045: }
1046: }
1047:
1048: /*
1049: * While we overlap succeeding segments trim them or,
1050: * if they are completely covered, dequeue them.
1051: */
1.155 itojun 1052: for (; q != NULL &&
1053: ntohs(ipqe->ipqe_ip->ip_off) + ntohs(ipqe->ipqe_ip->ip_len) >
1054: ntohs(q->ipqe_ip->ip_off); q = nq) {
1055: i = (ntohs(ipqe->ipqe_ip->ip_off) +
1056: ntohs(ipqe->ipqe_ip->ip_len)) - ntohs(q->ipqe_ip->ip_off);
1057: if (i < ntohs(q->ipqe_ip->ip_len)) {
1058: q->ipqe_ip->ip_len =
1059: htons(ntohs(q->ipqe_ip->ip_len) - i);
1060: q->ipqe_ip->ip_off =
1061: htons(ntohs(q->ipqe_ip->ip_off) + i);
1.50 thorpej 1062: m_adj(q->ipqe_m, i);
1.1 cgd 1063: break;
1064: }
1.148 matt 1065: nq = TAILQ_NEXT(q, ipqe_q);
1.50 thorpej 1066: m_freem(q->ipqe_m);
1.148 matt 1067: TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72 thorpej 1068: pool_put(&ipqent_pool, q);
1.1 cgd 1069: }
1070:
1071: insert:
1072: /*
1073: * Stick new segment in its place;
1074: * check for complete reassembly.
1075: */
1.25 cgd 1076: if (p == NULL) {
1.148 matt 1077: TAILQ_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
1.25 cgd 1078: } else {
1.148 matt 1079: TAILQ_INSERT_AFTER(&fp->ipq_fragq, p, ipqe, ipqe_q);
1.25 cgd 1080: }
1.1 cgd 1081: next = 0;
1.148 matt 1082: for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
1083: p = q, q = TAILQ_NEXT(q, ipqe_q)) {
1.155 itojun 1084: if (ntohs(q->ipqe_ip->ip_off) != next)
1.1 cgd 1085: return (0);
1.155 itojun 1086: next += ntohs(q->ipqe_ip->ip_len);
1.1 cgd 1087: }
1.25 cgd 1088: if (p->ipqe_mff)
1.1 cgd 1089: return (0);
1090:
1091: /*
1.41 thorpej 1092: * Reassembly is complete. Check for a bogus message size and
1093: * concatenate fragments.
1.1 cgd 1094: */
1.148 matt 1095: q = TAILQ_FIRST(&fp->ipq_fragq);
1.25 cgd 1096: ip = q->ipqe_ip;
1.41 thorpej 1097: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
1098: ipstat.ips_toolong++;
1099: ip_freef(fp);
1100: return (0);
1101: }
1.50 thorpej 1102: m = q->ipqe_m;
1.1 cgd 1103: t = m->m_next;
1104: m->m_next = 0;
1105: m_cat(m, t);
1.148 matt 1106: nq = TAILQ_NEXT(q, ipqe_q);
1.72 thorpej 1107: pool_put(&ipqent_pool, q);
1.25 cgd 1108: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 1109: t = q->ipqe_m;
1.148 matt 1110: nq = TAILQ_NEXT(q, ipqe_q);
1.72 thorpej 1111: pool_put(&ipqent_pool, q);
1.1 cgd 1112: m_cat(m, t);
1113: }
1114:
1115: /*
1116: * Create header for new ip packet by
1117: * modifying header of first packet;
1118: * dequeue and discard fragment reassembly header.
1119: * Make header visible.
1120: */
1.155 itojun 1121: ip->ip_len = htons(next);
1.25 cgd 1122: ip->ip_src = fp->ipq_src;
1123: ip->ip_dst = fp->ipq_dst;
1124: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 1125: FREE(fp, M_FTABLE);
1.131 itojun 1126: ip_nfragpackets--;
1.1 cgd 1127: m->m_len += (ip->ip_hl << 2);
1128: m->m_data -= (ip->ip_hl << 2);
1129: /* some debugging cruft by sklower, below, will go away soon */
1130: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1.109 augustss 1131: int plen = 0;
1.50 thorpej 1132: for (t = m; t; t = t->m_next)
1133: plen += t->m_len;
1134: m->m_pkthdr.len = plen;
1.1 cgd 1135: }
1.50 thorpej 1136: return (m);
1.1 cgd 1137:
1138: dropfrag:
1139: ipstat.ips_fragdropped++;
1140: m_freem(m);
1.72 thorpej 1141: pool_put(&ipqent_pool, ipqe);
1.1 cgd 1142: return (0);
1143: }
1144:
1145: /*
1146: * Free a fragment reassembly header and all
1147: * associated datagrams.
1148: */
1.8 mycroft 1149: void
1.1 cgd 1150: ip_freef(fp)
1151: struct ipq *fp;
1152: {
1.109 augustss 1153: struct ipqent *q, *p;
1.1 cgd 1154:
1.75 thorpej 1155: IPQ_LOCK_CHECK();
1156:
1.148 matt 1157: for (q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL; q = p) {
1158: p = TAILQ_NEXT(q, ipqe_q);
1.50 thorpej 1159: m_freem(q->ipqe_m);
1.148 matt 1160: TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72 thorpej 1161: pool_put(&ipqent_pool, q);
1.1 cgd 1162: }
1.25 cgd 1163: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 1164: FREE(fp, M_FTABLE);
1.131 itojun 1165: ip_nfragpackets--;
1.1 cgd 1166: }
1167:
1168: /*
1169: * IP timer processing;
1170: * if a timer expires on a reassembly
1171: * queue, discard it.
1172: */
1.8 mycroft 1173: void
1.1 cgd 1174: ip_slowtimo()
1175: {
1.109 augustss 1176: struct ipq *fp, *nfp;
1.24 mycroft 1177: int s = splsoftnet();
1.1 cgd 1178:
1.75 thorpej 1179: IPQ_LOCK();
1.140 matt 1180: for (fp = LIST_FIRST(&ipq); fp != NULL; fp = nfp) {
1181: nfp = LIST_NEXT(fp, ipq_q);
1.25 cgd 1182: if (--fp->ipq_ttl == 0) {
1.1 cgd 1183: ipstat.ips_fragtimeout++;
1.25 cgd 1184: ip_freef(fp);
1.1 cgd 1185: }
1186: }
1.131 itojun 1187: /*
1188: * If we are over the maximum number of fragments
1189: * (due to the limit being lowered), drain off
1190: * enough to get down to the new limit.
1191: */
1192: if (ip_maxfragpackets < 0)
1193: ;
1194: else {
1.140 matt 1195: while (ip_nfragpackets > ip_maxfragpackets && LIST_FIRST(&ipq))
1196: ip_freef(LIST_FIRST(&ipq));
1.131 itojun 1197: }
1.75 thorpej 1198: IPQ_UNLOCK();
1.63 matt 1199: #ifdef GATEWAY
1200: ipflow_slowtimo();
1201: #endif
1.1 cgd 1202: splx(s);
1203: }
1204:
1205: /*
1206: * Drain off all datagram fragments.
1207: */
1.8 mycroft 1208: void
1.1 cgd 1209: ip_drain()
1210: {
1211:
1.75 thorpej 1212: /*
1213: * We may be called from a device's interrupt context. If
1214: * the ipq is already busy, just bail out now.
1215: */
1216: if (ipq_lock_try() == 0)
1217: return;
1218:
1.140 matt 1219: while (LIST_FIRST(&ipq) != NULL) {
1.1 cgd 1220: ipstat.ips_fragdropped++;
1.140 matt 1221: ip_freef(LIST_FIRST(&ipq));
1.1 cgd 1222: }
1.75 thorpej 1223:
1224: IPQ_UNLOCK();
1.1 cgd 1225: }
1226:
1227: /*
1228: * Do option processing on a datagram,
1229: * possibly discarding it if bad options are encountered,
1230: * or forwarding it if source-routed.
1231: * Returns 1 if packet has been forwarded/freed,
1232: * 0 if the packet should be processed further.
1233: */
1.8 mycroft 1234: int
1.1 cgd 1235: ip_dooptions(m)
1236: struct mbuf *m;
1237: {
1.109 augustss 1238: struct ip *ip = mtod(m, struct ip *);
1239: u_char *cp, *cp0;
1240: struct ip_timestamp *ipt;
1241: struct in_ifaddr *ia;
1.1 cgd 1242: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.104 thorpej 1243: struct in_addr dst;
1.1 cgd 1244: n_time ntime;
1245:
1.13 mycroft 1246: dst = ip->ip_dst;
1.1 cgd 1247: cp = (u_char *)(ip + 1);
1248: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
1249: for (; cnt > 0; cnt -= optlen, cp += optlen) {
1250: opt = cp[IPOPT_OPTVAL];
1251: if (opt == IPOPT_EOL)
1252: break;
1253: if (opt == IPOPT_NOP)
1254: optlen = 1;
1255: else {
1.113 itojun 1256: if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1257: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1258: goto bad;
1259: }
1.1 cgd 1260: optlen = cp[IPOPT_OLEN];
1.114 itojun 1261: if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1.1 cgd 1262: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1263: goto bad;
1264: }
1265: }
1266: switch (opt) {
1267:
1268: default:
1269: break;
1270:
1271: /*
1272: * Source routing with record.
1273: * Find interface with current destination address.
1274: * If none on this machine then drop if strictly routed,
1275: * or do nothing if loosely routed.
1276: * Record interface address and bring up next address
1277: * component. If strictly routed make sure next
1278: * address is on directly accessible net.
1279: */
1280: case IPOPT_LSRR:
1281: case IPOPT_SSRR:
1.47 cjs 1282: if (ip_allowsrcrt == 0) {
1283: type = ICMP_UNREACH;
1284: code = ICMP_UNREACH_NET_PROHIB;
1285: goto bad;
1286: }
1.114 itojun 1287: if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1288: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1289: goto bad;
1290: }
1.1 cgd 1291: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1292: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1293: goto bad;
1294: }
1295: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 1296: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 1297: if (ia == 0) {
1298: if (opt == IPOPT_SSRR) {
1299: type = ICMP_UNREACH;
1300: code = ICMP_UNREACH_SRCFAIL;
1301: goto bad;
1302: }
1303: /*
1304: * Loose routing, and not at next destination
1305: * yet; nothing to do except forward.
1306: */
1307: break;
1308: }
1309: off--; /* 0 origin */
1.112 sommerfe 1310: if ((off + sizeof(struct in_addr)) > optlen) {
1.1 cgd 1311: /*
1312: * End of source route. Should be for us.
1313: */
1314: save_rte(cp, ip->ip_src);
1315: break;
1316: }
1317: /*
1318: * locate outgoing interface
1319: */
1320: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
1321: sizeof(ipaddr.sin_addr));
1.96 thorpej 1322: if (opt == IPOPT_SSRR)
1323: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1324: else
1.1 cgd 1325: ia = ip_rtaddr(ipaddr.sin_addr);
1326: if (ia == 0) {
1327: type = ICMP_UNREACH;
1328: code = ICMP_UNREACH_SRCFAIL;
1329: goto bad;
1330: }
1331: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 1332: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1333: (caddr_t)(cp + off), sizeof(struct in_addr));
1334: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 1335: /*
1336: * Let ip_intr's mcast routing check handle mcast pkts
1337: */
1.18 mycroft 1338: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 1339: break;
1340:
1341: case IPOPT_RR:
1.114 itojun 1342: if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1343: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1344: goto bad;
1345: }
1.1 cgd 1346: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1347: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1348: goto bad;
1349: }
1350: /*
1351: * If no space remains, ignore.
1352: */
1353: off--; /* 0 origin */
1.112 sommerfe 1354: if ((off + sizeof(struct in_addr)) > optlen)
1.1 cgd 1355: break;
1356: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
1357: sizeof(ipaddr.sin_addr));
1358: /*
1359: * locate outgoing interface; if we're the destination,
1360: * use the incoming interface (should be same).
1361: */
1.96 thorpej 1362: if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
1363: == NULL &&
1364: (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1.1 cgd 1365: type = ICMP_UNREACH;
1366: code = ICMP_UNREACH_HOST;
1367: goto bad;
1368: }
1.20 mycroft 1369: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1370: (caddr_t)(cp + off), sizeof(struct in_addr));
1371: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1372: break;
1373:
1374: case IPOPT_TS:
1375: code = cp - (u_char *)ip;
1376: ipt = (struct ip_timestamp *)cp;
1.114 itojun 1377: if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1378: code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1.1 cgd 1379: goto bad;
1.114 itojun 1380: }
1381: if (ipt->ipt_ptr < 5) {
1382: code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1383: goto bad;
1384: }
1.15 cgd 1385: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.114 itojun 1386: if (++ipt->ipt_oflw == 0) {
1387: code = (u_char *)&ipt->ipt_ptr -
1388: (u_char *)ip;
1.1 cgd 1389: goto bad;
1.114 itojun 1390: }
1.1 cgd 1391: break;
1392: }
1.104 thorpej 1393: cp0 = (cp + ipt->ipt_ptr - 1);
1.1 cgd 1394: switch (ipt->ipt_flg) {
1395:
1396: case IPOPT_TS_TSONLY:
1397: break;
1398:
1399: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1400: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114 itojun 1401: sizeof(struct in_addr) > ipt->ipt_len) {
1402: code = (u_char *)&ipt->ipt_ptr -
1403: (u_char *)ip;
1.1 cgd 1404: goto bad;
1.114 itojun 1405: }
1.13 mycroft 1406: ipaddr.sin_addr = dst;
1.96 thorpej 1407: ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
1408: m->m_pkthdr.rcvif));
1.13 mycroft 1409: if (ia == 0)
1410: continue;
1.104 thorpej 1411: bcopy(&ia->ia_addr.sin_addr,
1412: cp0, sizeof(struct in_addr));
1.1 cgd 1413: ipt->ipt_ptr += sizeof(struct in_addr);
1414: break;
1415:
1416: case IPOPT_TS_PRESPEC:
1.66 thorpej 1417: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114 itojun 1418: sizeof(struct in_addr) > ipt->ipt_len) {
1419: code = (u_char *)&ipt->ipt_ptr -
1420: (u_char *)ip;
1.1 cgd 1421: goto bad;
1.114 itojun 1422: }
1.104 thorpej 1423: bcopy(cp0, &ipaddr.sin_addr,
1.1 cgd 1424: sizeof(struct in_addr));
1.96 thorpej 1425: if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
1426: == NULL)
1.1 cgd 1427: continue;
1428: ipt->ipt_ptr += sizeof(struct in_addr);
1429: break;
1430:
1431: default:
1.114 itojun 1432: /* XXX can't take &ipt->ipt_flg */
1433: code = (u_char *)&ipt->ipt_ptr -
1434: (u_char *)ip + 1;
1.1 cgd 1435: goto bad;
1436: }
1437: ntime = iptime();
1.107 thorpej 1438: cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1439: bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1,
1.1 cgd 1440: sizeof(n_time));
1441: ipt->ipt_ptr += sizeof(n_time);
1442: }
1443: }
1444: if (forward) {
1.26 thorpej 1445: if (ip_forwsrcrt == 0) {
1446: type = ICMP_UNREACH;
1447: code = ICMP_UNREACH_SRCFAIL;
1448: goto bad;
1449: }
1.1 cgd 1450: ip_forward(m, 1);
1451: return (1);
1.13 mycroft 1452: }
1453: return (0);
1.1 cgd 1454: bad:
1.13 mycroft 1455: icmp_error(m, type, code, 0, 0);
1456: ipstat.ips_badoptions++;
1.1 cgd 1457: return (1);
1458: }
1459:
1460: /*
1461: * Given address of next destination (final or next hop),
1462: * return internet address info of interface to be used to get there.
1463: */
1464: struct in_ifaddr *
1465: ip_rtaddr(dst)
1466: struct in_addr dst;
1467: {
1.109 augustss 1468: struct sockaddr_in *sin;
1.1 cgd 1469:
1.19 mycroft 1470: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1471:
1.35 mycroft 1472: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1473: if (ipforward_rt.ro_rt) {
1474: RTFREE(ipforward_rt.ro_rt);
1475: ipforward_rt.ro_rt = 0;
1476: }
1477: sin->sin_family = AF_INET;
1478: sin->sin_len = sizeof(*sin);
1479: sin->sin_addr = dst;
1480:
1481: rtalloc(&ipforward_rt);
1482: }
1483: if (ipforward_rt.ro_rt == 0)
1484: return ((struct in_ifaddr *)0);
1.19 mycroft 1485: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1486: }
1487:
1488: /*
1489: * Save incoming source route for use in replies,
1490: * to be picked up later by ip_srcroute if the receiver is interested.
1491: */
1.13 mycroft 1492: void
1.1 cgd 1493: save_rte(option, dst)
1494: u_char *option;
1495: struct in_addr dst;
1496: {
1497: unsigned olen;
1498:
1499: olen = option[IPOPT_OLEN];
1500: #ifdef DIAGNOSTIC
1501: if (ipprintfs)
1.39 christos 1502: printf("save_rte: olen %d\n", olen);
1.89 itojun 1503: #endif /* 0 */
1.1 cgd 1504: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1505: return;
1506: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1507: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1508: ip_srcrt.dst = dst;
1509: }
1510:
1511: /*
1512: * Retrieve incoming source route for use in replies,
1513: * in the same form used by setsockopt.
1514: * The first hop is placed before the options, will be removed later.
1515: */
1516: struct mbuf *
1517: ip_srcroute()
1518: {
1.109 augustss 1519: struct in_addr *p, *q;
1520: struct mbuf *m;
1.1 cgd 1521:
1522: if (ip_nhops == 0)
1523: return ((struct mbuf *)0);
1524: m = m_get(M_DONTWAIT, MT_SOOPTS);
1525: if (m == 0)
1526: return ((struct mbuf *)0);
1527:
1.164 matt 1528: MCLAIM(m, &inetdomain.dom_mowner);
1.13 mycroft 1529: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1530:
1531: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1532: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1533: OPTSIZ;
1534: #ifdef DIAGNOSTIC
1535: if (ipprintfs)
1.39 christos 1536: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1537: #endif
1538:
1539: /*
1540: * First save first hop for return route
1541: */
1542: p = &ip_srcrt.route[ip_nhops - 1];
1543: *(mtod(m, struct in_addr *)) = *p--;
1544: #ifdef DIAGNOSTIC
1545: if (ipprintfs)
1.39 christos 1546: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1547: #endif
1548:
1549: /*
1550: * Copy option fields and padding (nop) to mbuf.
1551: */
1552: ip_srcrt.nop = IPOPT_NOP;
1553: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1554: bcopy((caddr_t)&ip_srcrt.nop,
1555: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1556: q = (struct in_addr *)(mtod(m, caddr_t) +
1557: sizeof(struct in_addr) + OPTSIZ);
1558: #undef OPTSIZ
1559: /*
1560: * Record return path as an IP source route,
1561: * reversing the path (pointers are now aligned).
1562: */
1563: while (p >= ip_srcrt.route) {
1564: #ifdef DIAGNOSTIC
1565: if (ipprintfs)
1.39 christos 1566: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1567: #endif
1568: *q++ = *p--;
1569: }
1570: /*
1571: * Last hop goes to final destination.
1572: */
1573: *q = ip_srcrt.dst;
1574: #ifdef DIAGNOSTIC
1575: if (ipprintfs)
1.39 christos 1576: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1577: #endif
1578: return (m);
1579: }
1580:
1581: /*
1582: * Strip out IP options, at higher
1583: * level protocol in the kernel.
1584: * Second argument is buffer to which options
1585: * will be moved, and return value is their length.
1586: * XXX should be deleted; last arg currently ignored.
1587: */
1.8 mycroft 1588: void
1.1 cgd 1589: ip_stripoptions(m, mopt)
1.109 augustss 1590: struct mbuf *m;
1.1 cgd 1591: struct mbuf *mopt;
1592: {
1.109 augustss 1593: int i;
1.1 cgd 1594: struct ip *ip = mtod(m, struct ip *);
1.109 augustss 1595: caddr_t opts;
1.1 cgd 1596: int olen;
1597:
1.79 mycroft 1598: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1599: opts = (caddr_t)(ip + 1);
1600: i = m->m_len - (sizeof (struct ip) + olen);
1601: bcopy(opts + olen, opts, (unsigned)i);
1602: m->m_len -= olen;
1603: if (m->m_flags & M_PKTHDR)
1604: m->m_pkthdr.len -= olen;
1.155 itojun 1605: ip->ip_len = htons(ntohs(ip->ip_len) - olen);
1.79 mycroft 1606: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1607: }
1608:
1.139 matt 1609: const int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1610: 0, 0, 0, 0,
1611: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1612: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1613: EMSGSIZE, EHOSTUNREACH, 0, 0,
1614: 0, 0, 0, 0,
1615: ENOPROTOOPT
1616: };
1617:
1618: /*
1619: * Forward a packet. If some error occurs return the sender
1620: * an icmp packet. Note we can't always generate a meaningful
1621: * icmp message because icmp doesn't have a large enough repertoire
1622: * of codes and types.
1623: *
1624: * If not forwarding, just drop the packet. This could be confusing
1625: * if ipforwarding was zero but some routing protocol was advancing
1626: * us as a gateway to somewhere. However, we must let the routing
1627: * protocol deal with that.
1628: *
1629: * The srcrt parameter indicates whether the packet is being forwarded
1630: * via a source route.
1631: */
1.13 mycroft 1632: void
1.1 cgd 1633: ip_forward(m, srcrt)
1634: struct mbuf *m;
1635: int srcrt;
1636: {
1.109 augustss 1637: struct ip *ip = mtod(m, struct ip *);
1638: struct sockaddr_in *sin;
1639: struct rtentry *rt;
1.28 christos 1640: int error, type = 0, code = 0;
1.1 cgd 1641: struct mbuf *mcopy;
1.13 mycroft 1642: n_long dest;
1643: struct ifnet *destifp;
1.173 jonathan 1644: #if defined(IPSEC) || defined(FAST_IPSEC)
1.89 itojun 1645: struct ifnet dummyifp;
1646: #endif
1.164 matt 1647:
1648: /*
1649: * We are now in the output path.
1650: */
1651: MCLAIM(m, &ip_tx_mowner);
1.135 thorpej 1652:
1653: /*
1654: * Clear any in-bound checksum flags for this packet.
1655: */
1656: m->m_pkthdr.csum_flags = 0;
1.1 cgd 1657:
1.13 mycroft 1658: dest = 0;
1.1 cgd 1659: #ifdef DIAGNOSTIC
1660: if (ipprintfs)
1.70 thorpej 1661: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1662: ntohl(ip->ip_src.s_addr),
1663: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1664: #endif
1.93 sommerfe 1665: if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1.1 cgd 1666: ipstat.ips_cantforward++;
1667: m_freem(m);
1668: return;
1669: }
1670: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1671: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1672: return;
1673: }
1674: ip->ip_ttl -= IPTTLDEC;
1675:
1.19 mycroft 1676: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1677: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1678: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1679: if (ipforward_rt.ro_rt) {
1680: RTFREE(ipforward_rt.ro_rt);
1681: ipforward_rt.ro_rt = 0;
1682: }
1683: sin->sin_family = AF_INET;
1.35 mycroft 1684: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1685: sin->sin_addr = ip->ip_dst;
1686:
1687: rtalloc(&ipforward_rt);
1688: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1689: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1690: return;
1691: }
1692: rt = ipforward_rt.ro_rt;
1693: }
1694:
1695: /*
1.34 mycroft 1696: * Save at most 68 bytes of the packet in case
1.1 cgd 1697: * we need to generate an ICMP message to the src.
1.119 itojun 1698: * Pullup to avoid sharing mbuf cluster between m and mcopy.
1.1 cgd 1699: */
1.155 itojun 1700: mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1.119 itojun 1701: if (mcopy)
1702: mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1.1 cgd 1703:
1704: /*
1705: * If forwarding packet using same interface that it came in on,
1706: * perhaps should send a redirect to sender to shortcut a hop.
1707: * Only send redirect if source is sending directly to us,
1708: * and if packet was not source routed (or has any options).
1709: * Also, don't send redirect if forwarding using a default route
1710: * or a route modified by a redirect.
1711: */
1712: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1713: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1714: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1715: ipsendredirects && !srcrt) {
1.19 mycroft 1716: if (rt->rt_ifa &&
1717: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1718: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1719: if (rt->rt_flags & RTF_GATEWAY)
1720: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1721: else
1722: dest = ip->ip_dst.s_addr;
1723: /*
1724: * Router requirements says to only send host
1725: * redirects.
1726: */
1727: type = ICMP_REDIRECT;
1728: code = ICMP_REDIRECT_HOST;
1.1 cgd 1729: #ifdef DIAGNOSTIC
1.77 thorpej 1730: if (ipprintfs)
1731: printf("redirect (%d) to %x\n", code,
1732: (u_int32_t)dest);
1.1 cgd 1733: #endif
1734: }
1735: }
1736:
1.27 thorpej 1737: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1.173 jonathan 1738: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1.174 itojun 1739: (struct ip_moptions *)NULL, (struct socket *)NULL);
1.173 jonathan 1740:
1.1 cgd 1741: if (error)
1742: ipstat.ips_cantforward++;
1743: else {
1744: ipstat.ips_forward++;
1745: if (type)
1746: ipstat.ips_redirectsent++;
1747: else {
1.63 matt 1748: if (mcopy) {
1749: #ifdef GATEWAY
1.64 thorpej 1750: if (mcopy->m_flags & M_CANFASTFWD)
1751: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1752: #endif
1.1 cgd 1753: m_freem(mcopy);
1.63 matt 1754: }
1.1 cgd 1755: return;
1756: }
1757: }
1758: if (mcopy == NULL)
1759: return;
1.13 mycroft 1760: destifp = NULL;
1761:
1.1 cgd 1762: switch (error) {
1763:
1764: case 0: /* forwarded, but need redirect */
1765: /* type, code set above */
1766: break;
1767:
1768: case ENETUNREACH: /* shouldn't happen, checked above */
1769: case EHOSTUNREACH:
1770: case ENETDOWN:
1771: case EHOSTDOWN:
1772: default:
1773: type = ICMP_UNREACH;
1774: code = ICMP_UNREACH_HOST;
1775: break;
1776:
1777: case EMSGSIZE:
1778: type = ICMP_UNREACH;
1779: code = ICMP_UNREACH_NEEDFRAG;
1.173 jonathan 1780: #if !defined(IPSEC) && !defined(FAST_IPSEC)
1.13 mycroft 1781: if (ipforward_rt.ro_rt)
1782: destifp = ipforward_rt.ro_rt->rt_ifp;
1.89 itojun 1783: #else
1784: /*
1785: * If the packet is routed over IPsec tunnel, tell the
1786: * originator the tunnel MTU.
1787: * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1788: * XXX quickhack!!!
1789: */
1790: if (ipforward_rt.ro_rt) {
1791: struct secpolicy *sp;
1792: int ipsecerror;
1.95 itojun 1793: size_t ipsechdr;
1.89 itojun 1794: struct route *ro;
1795:
1796: sp = ipsec4_getpolicybyaddr(mcopy,
1.170 itojun 1797: IPSEC_DIR_OUTBOUND, IP_FORWARDING,
1798: &ipsecerror);
1.89 itojun 1799:
1800: if (sp == NULL)
1801: destifp = ipforward_rt.ro_rt->rt_ifp;
1802: else {
1803: /* count IPsec header size */
1.95 itojun 1804: ipsechdr = ipsec4_hdrsiz(mcopy,
1.170 itojun 1805: IPSEC_DIR_OUTBOUND, NULL);
1.89 itojun 1806:
1807: /*
1808: * find the correct route for outer IPv4
1809: * header, compute tunnel MTU.
1810: *
1811: * XXX BUG ALERT
1812: * The "dummyifp" code relies upon the fact
1813: * that icmp_error() touches only ifp->if_mtu.
1814: */
1815: /*XXX*/
1816: destifp = NULL;
1817: if (sp->req != NULL
1.95 itojun 1818: && sp->req->sav != NULL
1819: && sp->req->sav->sah != NULL) {
1820: ro = &sp->req->sav->sah->sa_route;
1.89 itojun 1821: if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1822: dummyifp.if_mtu =
1.151 itojun 1823: ro->ro_rt->rt_rmx.rmx_mtu ?
1824: ro->ro_rt->rt_rmx.rmx_mtu :
1.89 itojun 1825: ro->ro_rt->rt_ifp->if_mtu;
1826: dummyifp.if_mtu -= ipsechdr;
1827: destifp = &dummyifp;
1828: }
1829: }
1830:
1.173 jonathan 1831: #ifdef IPSEC
1.89 itojun 1832: key_freesp(sp);
1.173 jonathan 1833: #else
1834: KEY_FREESP(&sp);
1835: #endif
1.89 itojun 1836: }
1837: }
1838: #endif /*IPSEC*/
1.1 cgd 1839: ipstat.ips_cantfrag++;
1840: break;
1841:
1842: case ENOBUFS:
1.143 itojun 1843: #if 1
1844: /*
1845: * a router should not generate ICMP_SOURCEQUENCH as
1846: * required in RFC1812 Requirements for IP Version 4 Routers.
1847: * source quench could be a big problem under DoS attacks,
1.149 wiz 1848: * or if the underlying interface is rate-limited.
1.143 itojun 1849: */
1850: if (mcopy)
1851: m_freem(mcopy);
1852: return;
1853: #else
1.1 cgd 1854: type = ICMP_SOURCEQUENCH;
1855: code = 0;
1856: break;
1.143 itojun 1857: #endif
1.1 cgd 1858: }
1.13 mycroft 1859: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1860: }
1861:
1862: void
1863: ip_savecontrol(inp, mp, ip, m)
1.109 augustss 1864: struct inpcb *inp;
1865: struct mbuf **mp;
1866: struct ip *ip;
1867: struct mbuf *m;
1.44 thorpej 1868: {
1869:
1870: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1871: struct timeval tv;
1872:
1873: microtime(&tv);
1874: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1875: SCM_TIMESTAMP, SOL_SOCKET);
1876: if (*mp)
1877: mp = &(*mp)->m_next;
1878: }
1879: if (inp->inp_flags & INP_RECVDSTADDR) {
1880: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1881: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1882: if (*mp)
1883: mp = &(*mp)->m_next;
1884: }
1885: #ifdef notyet
1886: /*
1887: * XXX
1888: * Moving these out of udp_input() made them even more broken
1889: * than they already were.
1890: * - fenner@parc.xerox.com
1891: */
1892: /* options were tossed already */
1893: if (inp->inp_flags & INP_RECVOPTS) {
1894: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1895: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1896: if (*mp)
1897: mp = &(*mp)->m_next;
1898: }
1899: /* ip_srcroute doesn't do what we want here, need to fix */
1900: if (inp->inp_flags & INP_RECVRETOPTS) {
1901: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1902: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1903: if (*mp)
1904: mp = &(*mp)->m_next;
1905: }
1906: #endif
1907: if (inp->inp_flags & INP_RECVIF) {
1908: struct sockaddr_dl sdl;
1909:
1910: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1911: sdl.sdl_family = AF_LINK;
1912: sdl.sdl_index = m->m_pkthdr.rcvif ?
1913: m->m_pkthdr.rcvif->if_index : 0;
1914: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1915: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1916: IP_RECVIF, IPPROTO_IP);
1917: if (*mp)
1918: mp = &(*mp)->m_next;
1919: }
1.13 mycroft 1920: }
1921:
1922: int
1923: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1924: int *name;
1925: u_int namelen;
1926: void *oldp;
1927: size_t *oldlenp;
1928: void *newp;
1929: size_t newlen;
1930: {
1.88 sommerfe 1931: extern int subnetsarelocal, hostzeroisbroadcast;
1.52 thorpej 1932:
1.54 lukem 1933: int error, old;
1934:
1.13 mycroft 1935: /* All sysctl names at this level are terminal. */
1936: if (namelen != 1)
1937: return (ENOTDIR);
1938:
1939: switch (name[0]) {
1940: case IPCTL_FORWARDING:
1941: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1942: case IPCTL_SENDREDIRECTS:
1943: return (sysctl_int(oldp, oldlenp, newp, newlen,
1944: &ipsendredirects));
1945: case IPCTL_DEFTTL:
1946: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1947: #ifdef notyet
1948: case IPCTL_DEFMTU:
1949: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1950: #endif
1.26 thorpej 1951: case IPCTL_FORWSRCRT:
1.47 cjs 1952: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1953: if (securelevel > 0)
1.46 cjs 1954: return (sysctl_rdint(oldp, oldlenp, newp,
1955: ip_forwsrcrt));
1956: else
1957: return (sysctl_int(oldp, oldlenp, newp, newlen,
1958: &ip_forwsrcrt));
1.27 thorpej 1959: case IPCTL_DIRECTEDBCAST:
1960: return (sysctl_int(oldp, oldlenp, newp, newlen,
1961: &ip_directedbcast));
1.47 cjs 1962: case IPCTL_ALLOWSRCRT:
1963: return (sysctl_int(oldp, oldlenp, newp, newlen,
1964: &ip_allowsrcrt));
1.52 thorpej 1965: case IPCTL_SUBNETSARELOCAL:
1966: return (sysctl_int(oldp, oldlenp, newp, newlen,
1967: &subnetsarelocal));
1.53 kml 1968: case IPCTL_MTUDISC:
1.60 kml 1969: error = sysctl_int(oldp, oldlenp, newp, newlen,
1970: &ip_mtudisc);
1.163 itojun 1971: if (error == 0 && ip_mtudisc == 0)
1972: rt_timer_queue_remove_all(ip_mtudisc_timeout_q, TRUE);
1.60 kml 1973: return error;
1.54 lukem 1974: case IPCTL_ANONPORTMIN:
1975: old = anonportmin;
1976: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1.118 itojun 1977: if (anonportmin >= anonportmax || anonportmin < 0
1978: || anonportmin > 65535
1.54 lukem 1979: #ifndef IPNOPRIVPORTS
1980: || anonportmin < IPPORT_RESERVED
1981: #endif
1982: ) {
1983: anonportmin = old;
1984: return (EINVAL);
1985: }
1986: return (error);
1987: case IPCTL_ANONPORTMAX:
1988: old = anonportmax;
1989: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1.118 itojun 1990: if (anonportmin >= anonportmax || anonportmax < 0
1991: || anonportmax > 65535
1.54 lukem 1992: #ifndef IPNOPRIVPORTS
1993: || anonportmax < IPPORT_RESERVED
1994: #endif
1995: ) {
1996: anonportmax = old;
1997: return (EINVAL);
1998: }
1.60 kml 1999: return (error);
2000: case IPCTL_MTUDISCTIMEOUT:
1.158 itojun 2001: old = ip_mtudisc_timeout;
1.60 kml 2002: error = sysctl_int(oldp, oldlenp, newp, newlen,
2003: &ip_mtudisc_timeout);
1.158 itojun 2004: if (ip_mtudisc_timeout < 0) {
2005: ip_mtudisc_timeout = old;
1.156 itojun 2006: return (EINVAL);
1.158 itojun 2007: }
1.163 itojun 2008: if (error == 0)
1.162 itojun 2009: rt_timer_queue_change(ip_mtudisc_timeout_q,
2010: ip_mtudisc_timeout);
1.54 lukem 2011: return (error);
1.65 matt 2012: #ifdef GATEWAY
2013: case IPCTL_MAXFLOWS:
1.67 thorpej 2014: {
2015: int s;
2016:
1.65 matt 2017: error = sysctl_int(oldp, oldlenp, newp, newlen,
2018: &ip_maxflows);
1.67 thorpej 2019: s = splsoftnet();
1.65 matt 2020: ipflow_reap(0);
1.67 thorpej 2021: splx(s);
1.65 matt 2022: return (error);
1.67 thorpej 2023: }
1.89 itojun 2024: #endif
1.90 itojun 2025: case IPCTL_HOSTZEROBROADCAST:
2026: return (sysctl_int(oldp, oldlenp, newp, newlen,
2027: &hostzeroisbroadcast));
1.89 itojun 2028: #if NGIF > 0
2029: case IPCTL_GIF_TTL:
1.157 itojun 2030: return (sysctl_int(oldp, oldlenp, newp, newlen,
1.90 itojun 2031: &ip_gif_ttl));
1.144 martin 2032: #endif
2033:
2034: #if NGRE > 0
2035: case IPCTL_GRE_TTL:
1.157 itojun 2036: return (sysctl_int(oldp, oldlenp, newp, newlen,
1.144 martin 2037: &ip_gre_ttl));
1.117 tron 2038: #endif
2039:
2040: #ifndef IPNOPRIVPORTS
2041: case IPCTL_LOWPORTMIN:
2042: old = lowportmin;
2043: error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmin);
2044: if (lowportmin >= lowportmax
2045: || lowportmin > IPPORT_RESERVEDMAX
2046: || lowportmin < IPPORT_RESERVEDMIN
2047: ) {
2048: lowportmin = old;
2049: return (EINVAL);
2050: }
2051: return (error);
2052: case IPCTL_LOWPORTMAX:
2053: old = lowportmax;
2054: error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmax);
2055: if (lowportmin >= lowportmax
2056: || lowportmax > IPPORT_RESERVEDMAX
2057: || lowportmax < IPPORT_RESERVEDMIN
2058: ) {
2059: lowportmax = old;
2060: return (EINVAL);
2061: }
2062: return (error);
1.65 matt 2063: #endif
1.131 itojun 2064:
2065: case IPCTL_MAXFRAGPACKETS:
2066: return (sysctl_int(oldp, oldlenp, newp, newlen,
2067: &ip_maxfragpackets));
1.88 sommerfe 2068:
1.165 christos 2069: case IPCTL_CHECKINTERFACE:
2070: return (sysctl_int(oldp, oldlenp, newp, newlen,
2071: &ip_checkinterface));
1.13 mycroft 2072: default:
2073: return (EOPNOTSUPP);
2074: }
2075: /* NOTREACHED */
1.1 cgd 2076: }
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