Annotation of src/sys/netinet/ip_input.c, Revision 1.180
1.180 ! jonathan 1: /* $NetBSD: ip_input.c,v 1.179 2003/09/28 04:45:14 mycroft 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>
1.180 ! jonathan 101: __KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.179 2003/09/28 04:45:14 mycroft 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");
1.89 itojun 445: #endif
1.164 matt 446:
1.1 cgd 447: /*
448: * If no IP addresses have been set yet but the interfaces
449: * are receiving, can't do anything with incoming packets yet.
450: */
1.140 matt 451: if (TAILQ_FIRST(&in_ifaddr) == 0)
1.1 cgd 452: goto bad;
453: ipstat.ips_total++;
1.154 thorpej 454: /*
455: * If the IP header is not aligned, slurp it up into a new
456: * mbuf with space for link headers, in the event we forward
457: * it. Otherwise, if it is aligned, make sure the entire
458: * base IP header is in the first mbuf of the chain.
459: */
460: if (IP_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) {
461: if ((m = m_copyup(m, sizeof(struct ip),
462: (max_linkhdr + 3) & ~3)) == NULL) {
463: /* XXXJRT new stat, please */
464: ipstat.ips_toosmall++;
465: return;
466: }
467: } else if (__predict_false(m->m_len < sizeof (struct ip))) {
468: if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
469: ipstat.ips_toosmall++;
470: return;
471: }
1.1 cgd 472: }
473: ip = mtod(m, struct ip *);
1.13 mycroft 474: if (ip->ip_v != IPVERSION) {
475: ipstat.ips_badvers++;
476: goto bad;
477: }
1.1 cgd 478: hlen = ip->ip_hl << 2;
479: if (hlen < sizeof(struct ip)) { /* minimum header length */
480: ipstat.ips_badhlen++;
481: goto bad;
482: }
483: if (hlen > m->m_len) {
484: if ((m = m_pullup(m, hlen)) == 0) {
485: ipstat.ips_badhlen++;
1.89 itojun 486: return;
1.1 cgd 487: }
488: ip = mtod(m, struct ip *);
489: }
1.98 thorpej 490:
1.85 hwr 491: /*
1.99 thorpej 492: * RFC1122: packets with a multicast source address are
1.98 thorpej 493: * not allowed.
1.85 hwr 494: */
495: if (IN_MULTICAST(ip->ip_src.s_addr)) {
1.130 itojun 496: ipstat.ips_badaddr++;
1.85 hwr 497: goto bad;
1.129 itojun 498: }
499:
500: /* 127/8 must not appear on wire - RFC1122 */
501: if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
502: (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
1.130 itojun 503: if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
504: ipstat.ips_badaddr++;
1.129 itojun 505: goto bad;
1.130 itojun 506: }
1.85 hwr 507: }
508:
1.135 thorpej 509: switch (m->m_pkthdr.csum_flags &
1.137 thorpej 510: ((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
1.135 thorpej 511: M_CSUM_IPv4_BAD)) {
512: case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
513: INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
514: goto badcsum;
515:
516: case M_CSUM_IPv4:
517: /* Checksum was okay. */
518: INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
519: break;
520:
521: default:
522: /* Must compute it ourselves. */
523: INET_CSUM_COUNTER_INCR(&ip_swcsum);
524: if (in_cksum(m, hlen) != 0)
525: goto bad;
526: break;
1.1 cgd 527: }
528:
1.121 thorpej 529: /* Retrieve the packet length. */
530: len = ntohs(ip->ip_len);
1.81 proff 531:
532: /*
533: * Check for additional length bogosity
534: */
1.84 proff 535: if (len < hlen) {
1.81 proff 536: ipstat.ips_badlen++;
537: goto bad;
538: }
1.1 cgd 539:
540: /*
541: * Check that the amount of data in the buffers
542: * is as at least much as the IP header would have us expect.
543: * Trim mbufs if longer than we expect.
544: * Drop packet if shorter than we expect.
545: */
1.35 mycroft 546: if (m->m_pkthdr.len < len) {
1.1 cgd 547: ipstat.ips_tooshort++;
548: goto bad;
549: }
1.35 mycroft 550: if (m->m_pkthdr.len > len) {
1.1 cgd 551: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 552: m->m_len = len;
553: m->m_pkthdr.len = len;
1.1 cgd 554: } else
1.35 mycroft 555: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 556: }
557:
1.94 itojun 558: #ifdef IPSEC
1.149 wiz 559: /* ipflow (IP fast forwarding) is not compatible with IPsec. */
1.94 itojun 560: m->m_flags &= ~M_CANFASTFWD;
561: #else
1.64 thorpej 562: /*
563: * Assume that we can create a fast-forward IP flow entry
564: * based on this packet.
565: */
566: m->m_flags |= M_CANFASTFWD;
1.94 itojun 567: #endif
1.64 thorpej 568:
1.36 mrg 569: #ifdef PFIL_HOOKS
1.33 mrg 570: /*
1.64 thorpej 571: * Run through list of hooks for input packets. If there are any
572: * filters which require that additional packets in the flow are
573: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
574: * Note that filters must _never_ set this flag, as another filter
575: * in the list may have previously cleared it.
1.33 mrg 576: */
1.127 itojun 577: /*
578: * let ipfilter look at packet on the wire,
579: * not the decapsulated packet.
580: */
581: #ifdef IPSEC
1.136 itojun 582: if (!ipsec_getnhist(m))
1.127 itojun 583: #else
584: if (1)
585: #endif
586: {
1.169 itojun 587: struct in_addr odst;
588:
589: odst = ip->ip_dst;
1.127 itojun 590: if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
1.168 itojun 591: PFIL_IN) != 0)
592: return;
1.127 itojun 593: if (m == NULL)
594: return;
595: ip = mtod(m, struct ip *);
1.142 darrenr 596: hlen = ip->ip_hl << 2;
1.169 itojun 597: srcrt = (odst.s_addr != ip->ip_dst.s_addr);
1.127 itojun 598: }
1.36 mrg 599: #endif /* PFIL_HOOKS */
1.123 thorpej 600:
601: #ifdef ALTQ
602: /* XXX Temporary until ALTQ is changed to use a pfil hook */
603: if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
604: /* packet dropped by traffic conditioner */
605: return;
606: }
607: #endif
1.121 thorpej 608:
609: /*
1.1 cgd 610: * Process options and, if not destined for us,
611: * ship it on. ip_dooptions returns 1 when an
612: * error was detected (causing an icmp message
613: * to be sent and the original packet to be freed).
614: */
615: ip_nhops = 0; /* for source routed packets */
616: if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.89 itojun 617: return;
1.1 cgd 618:
619: /*
1.165 christos 620: * Enable a consistency check between the destination address
621: * and the arrival interface for a unicast packet (the RFC 1122
622: * strong ES model) if IP forwarding is disabled and the packet
623: * is not locally generated.
624: *
625: * XXX - Checking also should be disabled if the destination
626: * address is ipnat'ed to a different interface.
627: *
628: * XXX - Checking is incompatible with IP aliases added
629: * to the loopback interface instead of the interface where
630: * the packets are received.
631: *
632: * XXX - We need to add a per ifaddr flag for this so that
633: * we get finer grain control.
634: */
635: checkif = ip_checkinterface && (ipforwarding == 0) &&
636: (m->m_pkthdr.rcvif != NULL) &&
637: ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0);
638:
639: /*
1.1 cgd 640: * Check our list of addresses, to see if the packet is for us.
1.100 itojun 641: *
642: * Traditional 4.4BSD did not consult IFF_UP at all.
643: * The behavior here is to treat addresses on !IFF_UP interface
644: * as not mine.
1.1 cgd 645: */
1.100 itojun 646: downmatch = 0;
1.140 matt 647: LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
1.97 itojun 648: if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
1.165 christos 649: if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif)
650: continue;
1.97 itojun 651: if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
652: break;
1.100 itojun 653: else
654: downmatch++;
1.97 itojun 655: }
656: }
1.86 thorpej 657: if (ia != NULL)
658: goto ours;
1.57 tls 659: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
1.140 matt 660: TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) {
661: if (ifa->ifa_addr->sa_family != AF_INET)
662: continue;
1.57 tls 663: ia = ifatoia(ifa);
1.35 mycroft 664: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
665: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 666: /*
667: * Look for all-0's host part (old broadcast addr),
668: * either for subnet or net.
669: */
670: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 671: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 672: goto ours;
1.57 tls 673: /*
674: * An interface with IP address zero accepts
675: * all packets that arrive on that interface.
676: */
677: if (in_nullhost(ia->ia_addr.sin_addr))
678: goto ours;
1.1 cgd 679: }
680: }
1.18 mycroft 681: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 682: struct in_multi *inm;
683: #ifdef MROUTING
684: extern struct socket *ip_mrouter;
1.10 brezak 685:
1.147 matt 686: if (M_READONLY(m)) {
1.10 brezak 687: if ((m = m_pullup(m, hlen)) == 0) {
688: ipstat.ips_toosmall++;
1.89 itojun 689: return;
1.10 brezak 690: }
691: ip = mtod(m, struct ip *);
692: }
1.4 hpeyerl 693:
694: if (ip_mrouter) {
695: /*
696: * If we are acting as a multicast router, all
697: * incoming multicast packets are passed to the
698: * kernel-level multicast forwarding function.
699: * The packet is returned (relatively) intact; if
700: * ip_mforward() returns a non-zero value, the packet
701: * must be discarded, else it may be accepted below.
702: *
703: * (The IP ident field is put in the same byte order
704: * as expected when ip_mforward() is called from
705: * ip_output().)
706: */
1.13 mycroft 707: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
708: ipstat.ips_cantforward++;
1.4 hpeyerl 709: m_freem(m);
1.89 itojun 710: return;
1.4 hpeyerl 711: }
712:
713: /*
714: * The process-level routing demon needs to receive
715: * all multicast IGMP packets, whether or not this
716: * host belongs to their destination groups.
717: */
718: if (ip->ip_p == IPPROTO_IGMP)
719: goto ours;
1.13 mycroft 720: ipstat.ips_forward++;
1.4 hpeyerl 721: }
722: #endif
723: /*
724: * See if we belong to the destination multicast group on the
725: * arrival interface.
726: */
727: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
728: if (inm == NULL) {
1.13 mycroft 729: ipstat.ips_cantforward++;
1.4 hpeyerl 730: m_freem(m);
1.89 itojun 731: return;
1.4 hpeyerl 732: }
733: goto ours;
734: }
1.19 mycroft 735: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 736: in_nullhost(ip->ip_dst))
1.1 cgd 737: goto ours;
738:
739: /*
740: * Not for us; forward if possible and desirable.
741: */
742: if (ipforwarding == 0) {
743: ipstat.ips_cantforward++;
744: m_freem(m);
1.100 itojun 745: } else {
746: /*
747: * If ip_dst matched any of my address on !IFF_UP interface,
748: * and there's no IFF_UP interface that matches ip_dst,
749: * send icmp unreach. Forwarding it will result in in-kernel
750: * forwarding loop till TTL goes to 0.
751: */
752: if (downmatch) {
753: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
754: ipstat.ips_cantforward++;
755: return;
756: }
1.145 itojun 757: #ifdef IPSEC
758: if (ipsec4_in_reject(m, NULL)) {
759: ipsecstat.in_polvio++;
760: goto bad;
761: }
762: #endif
1.173 jonathan 763: #ifdef FAST_IPSEC
764: mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
765: s = splsoftnet();
766: if (mtag != NULL) {
767: tdbi = (struct tdb_ident *)(mtag + 1);
768: sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
769: } else {
770: sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
771: IP_FORWARDING, &error);
772: }
773: if (sp == NULL) { /* NB: can happen if error */
774: splx(s);
775: /*XXX error stat???*/
776: DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
777: goto bad;
778: }
779:
780: /*
781: * Check security policy against packet attributes.
782: */
783: error = ipsec_in_reject(sp, m);
784: KEY_FREESP(&sp);
785: splx(s);
786: if (error) {
787: ipstat.ips_cantforward++;
788: goto bad;
789: }
790: #endif /* FAST_IPSEC */
1.145 itojun 791:
1.169 itojun 792: ip_forward(m, srcrt);
1.100 itojun 793: }
1.89 itojun 794: return;
1.1 cgd 795:
796: ours:
797: /*
798: * If offset or IP_MF are set, must reassemble.
799: * Otherwise, nothing need be done.
800: * (We could look in the reassembly queue to see
801: * if the packet was previously fragmented,
802: * but it's not worth the time; just let them time out.)
803: */
1.155 itojun 804: if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
805: if (M_READONLY(m)) {
806: if ((m = m_pullup(m, hlen)) == NULL) {
807: ipstat.ips_toosmall++;
808: goto bad;
809: }
810: ip = mtod(m, struct ip *);
811: }
812:
1.1 cgd 813: /*
814: * Look for queue of fragments
815: * of this datagram.
816: */
1.75 thorpej 817: IPQ_LOCK();
1.140 matt 818: LIST_FOREACH(fp, &ipq, ipq_q)
1.1 cgd 819: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 820: in_hosteq(ip->ip_src, fp->ipq_src) &&
821: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 822: ip->ip_p == fp->ipq_p)
823: goto found;
824: fp = 0;
825: found:
826:
827: /*
828: * Adjust ip_len to not reflect header,
1.25 cgd 829: * set ipqe_mff if more fragments are expected,
1.1 cgd 830: * convert offset of this to bytes.
831: */
1.155 itojun 832: ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
833: mff = (ip->ip_off & htons(IP_MF)) != 0;
1.25 cgd 834: if (mff) {
1.16 cgd 835: /*
836: * Make sure that fragments have a data length
837: * that's a non-zero multiple of 8 bytes.
838: */
1.155 itojun 839: if (ntohs(ip->ip_len) == 0 ||
840: (ntohs(ip->ip_len) & 0x7) != 0) {
1.16 cgd 841: ipstat.ips_badfrags++;
1.75 thorpej 842: IPQ_UNLOCK();
1.16 cgd 843: goto bad;
844: }
845: }
1.155 itojun 846: ip->ip_off = htons((ntohs(ip->ip_off) & IP_OFFMASK) << 3);
1.1 cgd 847:
848: /*
849: * If datagram marked as having more fragments
850: * or if this is not the first fragment,
851: * attempt reassembly; if it succeeds, proceed.
852: */
1.155 itojun 853: if (mff || ip->ip_off != htons(0)) {
1.1 cgd 854: ipstat.ips_fragments++;
1.72 thorpej 855: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 856: if (ipqe == NULL) {
857: ipstat.ips_rcvmemdrop++;
1.75 thorpej 858: IPQ_UNLOCK();
1.25 cgd 859: goto bad;
860: }
861: ipqe->ipqe_mff = mff;
1.50 thorpej 862: ipqe->ipqe_m = m;
1.25 cgd 863: ipqe->ipqe_ip = ip;
1.50 thorpej 864: m = ip_reass(ipqe, fp);
1.75 thorpej 865: if (m == 0) {
866: IPQ_UNLOCK();
1.89 itojun 867: return;
1.75 thorpej 868: }
1.13 mycroft 869: ipstat.ips_reassembled++;
1.50 thorpej 870: ip = mtod(m, struct ip *);
1.74 thorpej 871: hlen = ip->ip_hl << 2;
1.155 itojun 872: ip->ip_len = htons(ntohs(ip->ip_len) + hlen);
1.1 cgd 873: } else
874: if (fp)
875: ip_freef(fp);
1.75 thorpej 876: IPQ_UNLOCK();
1.79 mycroft 877: }
1.128 itojun 878:
1.173 jonathan 879: #if defined(IPSEC)
1.128 itojun 880: /*
881: * enforce IPsec policy checking if we are seeing last header.
882: * note that we do not visit this with protocols with pcb layer
883: * code - like udp/tcp/raw ip.
884: */
885: if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
886: ipsec4_in_reject(m, NULL)) {
887: ipsecstat.in_polvio++;
888: goto bad;
889: }
890: #endif
1.173 jonathan 891: #if FAST_IPSEC
892: /*
893: * enforce IPsec policy checking if we are seeing last header.
894: * note that we do not visit this with protocols with pcb layer
895: * code - like udp/tcp/raw ip.
896: */
897: if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
898: /*
899: * Check if the packet has already had IPsec processing
900: * done. If so, then just pass it along. This tag gets
901: * set during AH, ESP, etc. input handling, before the
902: * packet is returned to the ip input queue for delivery.
903: */
904: mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
905: s = splsoftnet();
906: if (mtag != NULL) {
907: tdbi = (struct tdb_ident *)(mtag + 1);
908: sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
909: } else {
910: sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
911: IP_FORWARDING, &error);
912: }
913: if (sp != NULL) {
914: /*
915: * Check security policy against packet attributes.
916: */
917: error = ipsec_in_reject(sp, m);
918: KEY_FREESP(&sp);
919: } else {
920: /* XXX error stat??? */
921: error = EINVAL;
922: DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
923: goto bad;
924: }
925: splx(s);
926: if (error)
927: goto bad;
928: }
929: #endif /* FAST_IPSEC */
1.1 cgd 930:
931: /*
932: * Switch out to protocol's input routine.
933: */
1.82 aidan 934: #if IFA_STATS
1.122 itojun 935: if (ia && ip)
1.155 itojun 936: ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
1.82 aidan 937: #endif
1.1 cgd 938: ipstat.ips_delivered++;
1.89 itojun 939: {
940: int off = hlen, nh = ip->ip_p;
941:
942: (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
943: return;
944: }
1.1 cgd 945: bad:
946: m_freem(m);
1.135 thorpej 947: return;
948:
949: badcsum:
950: ipstat.ips_badsum++;
951: m_freem(m);
1.1 cgd 952: }
953:
954: /*
955: * Take incoming datagram fragment and try to
956: * reassemble it into whole datagram. If a chain for
957: * reassembly of this datagram already exists, then it
958: * is given as fp; otherwise have to make a chain.
959: */
1.50 thorpej 960: struct mbuf *
1.25 cgd 961: ip_reass(ipqe, fp)
1.109 augustss 962: struct ipqent *ipqe;
963: struct ipq *fp;
1.1 cgd 964: {
1.109 augustss 965: struct mbuf *m = ipqe->ipqe_m;
966: struct ipqent *nq, *p, *q;
1.25 cgd 967: struct ip *ip;
1.1 cgd 968: struct mbuf *t;
1.25 cgd 969: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 970: int i, next;
971:
1.75 thorpej 972: IPQ_LOCK_CHECK();
973:
1.1 cgd 974: /*
975: * Presence of header sizes in mbufs
976: * would confuse code below.
977: */
978: m->m_data += hlen;
979: m->m_len -= hlen;
980:
981: /*
982: * If first fragment to arrive, create a reassembly queue.
983: */
984: if (fp == 0) {
1.131 itojun 985: /*
986: * Enforce upper bound on number of fragmented packets
987: * for which we attempt reassembly;
988: * If maxfrag is 0, never accept fragments.
989: * If maxfrag is -1, accept all fragments without limitation.
990: */
991: if (ip_maxfragpackets < 0)
992: ;
993: else if (ip_nfragpackets >= ip_maxfragpackets)
994: goto dropfrag;
995: ip_nfragpackets++;
1.50 thorpej 996: MALLOC(fp, struct ipq *, sizeof (struct ipq),
997: M_FTABLE, M_NOWAIT);
998: if (fp == NULL)
1.1 cgd 999: goto dropfrag;
1.25 cgd 1000: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 1001: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 1002: fp->ipq_p = ipqe->ipqe_ip->ip_p;
1003: fp->ipq_id = ipqe->ipqe_ip->ip_id;
1.148 matt 1004: TAILQ_INIT(&fp->ipq_fragq);
1.25 cgd 1005: fp->ipq_src = ipqe->ipqe_ip->ip_src;
1006: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
1007: p = NULL;
1.1 cgd 1008: goto insert;
1009: }
1010:
1011: /*
1012: * Find a segment which begins after this one does.
1013: */
1.148 matt 1014: for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
1015: p = q, q = TAILQ_NEXT(q, ipqe_q))
1.155 itojun 1016: if (ntohs(q->ipqe_ip->ip_off) > ntohs(ipqe->ipqe_ip->ip_off))
1.1 cgd 1017: break;
1018:
1019: /*
1020: * If there is a preceding segment, it may provide some of
1021: * our data already. If so, drop the data from the incoming
1022: * segment. If it provides all of our data, drop us.
1023: */
1.25 cgd 1024: if (p != NULL) {
1.155 itojun 1025: i = ntohs(p->ipqe_ip->ip_off) + ntohs(p->ipqe_ip->ip_len) -
1026: ntohs(ipqe->ipqe_ip->ip_off);
1.1 cgd 1027: if (i > 0) {
1.155 itojun 1028: if (i >= ntohs(ipqe->ipqe_ip->ip_len))
1.1 cgd 1029: goto dropfrag;
1.50 thorpej 1030: m_adj(ipqe->ipqe_m, i);
1.155 itojun 1031: ipqe->ipqe_ip->ip_off =
1032: htons(ntohs(ipqe->ipqe_ip->ip_off) + i);
1033: ipqe->ipqe_ip->ip_len =
1034: htons(ntohs(ipqe->ipqe_ip->ip_len) - i);
1.1 cgd 1035: }
1036: }
1037:
1038: /*
1039: * While we overlap succeeding segments trim them or,
1040: * if they are completely covered, dequeue them.
1041: */
1.155 itojun 1042: for (; q != NULL &&
1043: ntohs(ipqe->ipqe_ip->ip_off) + ntohs(ipqe->ipqe_ip->ip_len) >
1044: ntohs(q->ipqe_ip->ip_off); q = nq) {
1045: i = (ntohs(ipqe->ipqe_ip->ip_off) +
1046: ntohs(ipqe->ipqe_ip->ip_len)) - ntohs(q->ipqe_ip->ip_off);
1047: if (i < ntohs(q->ipqe_ip->ip_len)) {
1048: q->ipqe_ip->ip_len =
1049: htons(ntohs(q->ipqe_ip->ip_len) - i);
1050: q->ipqe_ip->ip_off =
1051: htons(ntohs(q->ipqe_ip->ip_off) + i);
1.50 thorpej 1052: m_adj(q->ipqe_m, i);
1.1 cgd 1053: break;
1054: }
1.148 matt 1055: nq = TAILQ_NEXT(q, ipqe_q);
1.50 thorpej 1056: m_freem(q->ipqe_m);
1.148 matt 1057: TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72 thorpej 1058: pool_put(&ipqent_pool, q);
1.1 cgd 1059: }
1060:
1061: insert:
1062: /*
1063: * Stick new segment in its place;
1064: * check for complete reassembly.
1065: */
1.25 cgd 1066: if (p == NULL) {
1.148 matt 1067: TAILQ_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
1.25 cgd 1068: } else {
1.148 matt 1069: TAILQ_INSERT_AFTER(&fp->ipq_fragq, p, ipqe, ipqe_q);
1.25 cgd 1070: }
1.1 cgd 1071: next = 0;
1.148 matt 1072: for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
1073: p = q, q = TAILQ_NEXT(q, ipqe_q)) {
1.155 itojun 1074: if (ntohs(q->ipqe_ip->ip_off) != next)
1.1 cgd 1075: return (0);
1.155 itojun 1076: next += ntohs(q->ipqe_ip->ip_len);
1.1 cgd 1077: }
1.25 cgd 1078: if (p->ipqe_mff)
1.1 cgd 1079: return (0);
1080:
1081: /*
1.41 thorpej 1082: * Reassembly is complete. Check for a bogus message size and
1083: * concatenate fragments.
1.1 cgd 1084: */
1.148 matt 1085: q = TAILQ_FIRST(&fp->ipq_fragq);
1.25 cgd 1086: ip = q->ipqe_ip;
1.41 thorpej 1087: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
1088: ipstat.ips_toolong++;
1089: ip_freef(fp);
1090: return (0);
1091: }
1.50 thorpej 1092: m = q->ipqe_m;
1.1 cgd 1093: t = m->m_next;
1094: m->m_next = 0;
1095: m_cat(m, t);
1.148 matt 1096: nq = TAILQ_NEXT(q, ipqe_q);
1.72 thorpej 1097: pool_put(&ipqent_pool, q);
1.25 cgd 1098: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 1099: t = q->ipqe_m;
1.148 matt 1100: nq = TAILQ_NEXT(q, ipqe_q);
1.72 thorpej 1101: pool_put(&ipqent_pool, q);
1.1 cgd 1102: m_cat(m, t);
1103: }
1104:
1105: /*
1106: * Create header for new ip packet by
1107: * modifying header of first packet;
1108: * dequeue and discard fragment reassembly header.
1109: * Make header visible.
1110: */
1.155 itojun 1111: ip->ip_len = htons(next);
1.25 cgd 1112: ip->ip_src = fp->ipq_src;
1113: ip->ip_dst = fp->ipq_dst;
1114: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 1115: FREE(fp, M_FTABLE);
1.131 itojun 1116: ip_nfragpackets--;
1.1 cgd 1117: m->m_len += (ip->ip_hl << 2);
1118: m->m_data -= (ip->ip_hl << 2);
1119: /* some debugging cruft by sklower, below, will go away soon */
1120: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1.109 augustss 1121: int plen = 0;
1.50 thorpej 1122: for (t = m; t; t = t->m_next)
1123: plen += t->m_len;
1124: m->m_pkthdr.len = plen;
1.1 cgd 1125: }
1.50 thorpej 1126: return (m);
1.1 cgd 1127:
1128: dropfrag:
1129: ipstat.ips_fragdropped++;
1130: m_freem(m);
1.72 thorpej 1131: pool_put(&ipqent_pool, ipqe);
1.1 cgd 1132: return (0);
1133: }
1134:
1135: /*
1136: * Free a fragment reassembly header and all
1137: * associated datagrams.
1138: */
1.8 mycroft 1139: void
1.1 cgd 1140: ip_freef(fp)
1141: struct ipq *fp;
1142: {
1.109 augustss 1143: struct ipqent *q, *p;
1.1 cgd 1144:
1.75 thorpej 1145: IPQ_LOCK_CHECK();
1146:
1.148 matt 1147: for (q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL; q = p) {
1148: p = TAILQ_NEXT(q, ipqe_q);
1.50 thorpej 1149: m_freem(q->ipqe_m);
1.148 matt 1150: TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72 thorpej 1151: pool_put(&ipqent_pool, q);
1.1 cgd 1152: }
1.25 cgd 1153: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 1154: FREE(fp, M_FTABLE);
1.131 itojun 1155: ip_nfragpackets--;
1.1 cgd 1156: }
1157:
1158: /*
1159: * IP timer processing;
1160: * if a timer expires on a reassembly
1161: * queue, discard it.
1162: */
1.8 mycroft 1163: void
1.1 cgd 1164: ip_slowtimo()
1165: {
1.109 augustss 1166: struct ipq *fp, *nfp;
1.24 mycroft 1167: int s = splsoftnet();
1.1 cgd 1168:
1.75 thorpej 1169: IPQ_LOCK();
1.140 matt 1170: for (fp = LIST_FIRST(&ipq); fp != NULL; fp = nfp) {
1171: nfp = LIST_NEXT(fp, ipq_q);
1.25 cgd 1172: if (--fp->ipq_ttl == 0) {
1.1 cgd 1173: ipstat.ips_fragtimeout++;
1.25 cgd 1174: ip_freef(fp);
1.1 cgd 1175: }
1176: }
1.131 itojun 1177: /*
1178: * If we are over the maximum number of fragments
1179: * (due to the limit being lowered), drain off
1180: * enough to get down to the new limit.
1181: */
1182: if (ip_maxfragpackets < 0)
1183: ;
1184: else {
1.140 matt 1185: while (ip_nfragpackets > ip_maxfragpackets && LIST_FIRST(&ipq))
1186: ip_freef(LIST_FIRST(&ipq));
1.131 itojun 1187: }
1.75 thorpej 1188: IPQ_UNLOCK();
1.63 matt 1189: #ifdef GATEWAY
1190: ipflow_slowtimo();
1191: #endif
1.1 cgd 1192: splx(s);
1193: }
1194:
1195: /*
1196: * Drain off all datagram fragments.
1197: */
1.8 mycroft 1198: void
1.1 cgd 1199: ip_drain()
1200: {
1201:
1.75 thorpej 1202: /*
1203: * We may be called from a device's interrupt context. If
1204: * the ipq is already busy, just bail out now.
1205: */
1206: if (ipq_lock_try() == 0)
1207: return;
1208:
1.140 matt 1209: while (LIST_FIRST(&ipq) != NULL) {
1.1 cgd 1210: ipstat.ips_fragdropped++;
1.140 matt 1211: ip_freef(LIST_FIRST(&ipq));
1.1 cgd 1212: }
1.75 thorpej 1213:
1214: IPQ_UNLOCK();
1.1 cgd 1215: }
1216:
1217: /*
1218: * Do option processing on a datagram,
1219: * possibly discarding it if bad options are encountered,
1220: * or forwarding it if source-routed.
1221: * Returns 1 if packet has been forwarded/freed,
1222: * 0 if the packet should be processed further.
1223: */
1.8 mycroft 1224: int
1.1 cgd 1225: ip_dooptions(m)
1226: struct mbuf *m;
1227: {
1.109 augustss 1228: struct ip *ip = mtod(m, struct ip *);
1229: u_char *cp, *cp0;
1230: struct ip_timestamp *ipt;
1231: struct in_ifaddr *ia;
1.1 cgd 1232: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.104 thorpej 1233: struct in_addr dst;
1.1 cgd 1234: n_time ntime;
1235:
1.13 mycroft 1236: dst = ip->ip_dst;
1.1 cgd 1237: cp = (u_char *)(ip + 1);
1238: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
1239: for (; cnt > 0; cnt -= optlen, cp += optlen) {
1240: opt = cp[IPOPT_OPTVAL];
1241: if (opt == IPOPT_EOL)
1242: break;
1243: if (opt == IPOPT_NOP)
1244: optlen = 1;
1245: else {
1.113 itojun 1246: if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1247: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1248: goto bad;
1249: }
1.1 cgd 1250: optlen = cp[IPOPT_OLEN];
1.114 itojun 1251: if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1.1 cgd 1252: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1253: goto bad;
1254: }
1255: }
1256: switch (opt) {
1257:
1258: default:
1259: break;
1260:
1261: /*
1262: * Source routing with record.
1263: * Find interface with current destination address.
1264: * If none on this machine then drop if strictly routed,
1265: * or do nothing if loosely routed.
1266: * Record interface address and bring up next address
1267: * component. If strictly routed make sure next
1268: * address is on directly accessible net.
1269: */
1270: case IPOPT_LSRR:
1271: case IPOPT_SSRR:
1.47 cjs 1272: if (ip_allowsrcrt == 0) {
1273: type = ICMP_UNREACH;
1274: code = ICMP_UNREACH_NET_PROHIB;
1275: goto bad;
1276: }
1.114 itojun 1277: if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1278: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1279: goto bad;
1280: }
1.1 cgd 1281: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1282: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1283: goto bad;
1284: }
1285: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 1286: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 1287: if (ia == 0) {
1288: if (opt == IPOPT_SSRR) {
1289: type = ICMP_UNREACH;
1290: code = ICMP_UNREACH_SRCFAIL;
1291: goto bad;
1292: }
1293: /*
1294: * Loose routing, and not at next destination
1295: * yet; nothing to do except forward.
1296: */
1297: break;
1298: }
1299: off--; /* 0 origin */
1.112 sommerfe 1300: if ((off + sizeof(struct in_addr)) > optlen) {
1.1 cgd 1301: /*
1302: * End of source route. Should be for us.
1303: */
1304: save_rte(cp, ip->ip_src);
1305: break;
1306: }
1307: /*
1308: * locate outgoing interface
1309: */
1310: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
1311: sizeof(ipaddr.sin_addr));
1.96 thorpej 1312: if (opt == IPOPT_SSRR)
1313: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1314: else
1.1 cgd 1315: ia = ip_rtaddr(ipaddr.sin_addr);
1316: if (ia == 0) {
1317: type = ICMP_UNREACH;
1318: code = ICMP_UNREACH_SRCFAIL;
1319: goto bad;
1320: }
1321: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 1322: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1323: (caddr_t)(cp + off), sizeof(struct in_addr));
1324: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 1325: /*
1326: * Let ip_intr's mcast routing check handle mcast pkts
1327: */
1.18 mycroft 1328: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 1329: break;
1330:
1331: case IPOPT_RR:
1.114 itojun 1332: if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1333: code = &cp[IPOPT_OLEN] - (u_char *)ip;
1334: goto bad;
1335: }
1.1 cgd 1336: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1337: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1338: goto bad;
1339: }
1340: /*
1341: * If no space remains, ignore.
1342: */
1343: off--; /* 0 origin */
1.112 sommerfe 1344: if ((off + sizeof(struct in_addr)) > optlen)
1.1 cgd 1345: break;
1346: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
1347: sizeof(ipaddr.sin_addr));
1348: /*
1349: * locate outgoing interface; if we're the destination,
1350: * use the incoming interface (should be same).
1351: */
1.96 thorpej 1352: if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
1353: == NULL &&
1354: (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1.1 cgd 1355: type = ICMP_UNREACH;
1356: code = ICMP_UNREACH_HOST;
1357: goto bad;
1358: }
1.20 mycroft 1359: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1360: (caddr_t)(cp + off), sizeof(struct in_addr));
1361: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1362: break;
1363:
1364: case IPOPT_TS:
1365: code = cp - (u_char *)ip;
1366: ipt = (struct ip_timestamp *)cp;
1.114 itojun 1367: if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1368: code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1.1 cgd 1369: goto bad;
1.114 itojun 1370: }
1371: if (ipt->ipt_ptr < 5) {
1372: code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1373: goto bad;
1374: }
1.15 cgd 1375: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.114 itojun 1376: if (++ipt->ipt_oflw == 0) {
1377: code = (u_char *)&ipt->ipt_ptr -
1378: (u_char *)ip;
1.1 cgd 1379: goto bad;
1.114 itojun 1380: }
1.1 cgd 1381: break;
1382: }
1.104 thorpej 1383: cp0 = (cp + ipt->ipt_ptr - 1);
1.1 cgd 1384: switch (ipt->ipt_flg) {
1385:
1386: case IPOPT_TS_TSONLY:
1387: break;
1388:
1389: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1390: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114 itojun 1391: sizeof(struct in_addr) > ipt->ipt_len) {
1392: code = (u_char *)&ipt->ipt_ptr -
1393: (u_char *)ip;
1.1 cgd 1394: goto bad;
1.114 itojun 1395: }
1.13 mycroft 1396: ipaddr.sin_addr = dst;
1.96 thorpej 1397: ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
1398: m->m_pkthdr.rcvif));
1.13 mycroft 1399: if (ia == 0)
1400: continue;
1.104 thorpej 1401: bcopy(&ia->ia_addr.sin_addr,
1402: cp0, sizeof(struct in_addr));
1.1 cgd 1403: ipt->ipt_ptr += sizeof(struct in_addr);
1404: break;
1405:
1406: case IPOPT_TS_PRESPEC:
1.66 thorpej 1407: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114 itojun 1408: sizeof(struct in_addr) > ipt->ipt_len) {
1409: code = (u_char *)&ipt->ipt_ptr -
1410: (u_char *)ip;
1.1 cgd 1411: goto bad;
1.114 itojun 1412: }
1.104 thorpej 1413: bcopy(cp0, &ipaddr.sin_addr,
1.1 cgd 1414: sizeof(struct in_addr));
1.96 thorpej 1415: if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
1416: == NULL)
1.1 cgd 1417: continue;
1418: ipt->ipt_ptr += sizeof(struct in_addr);
1419: break;
1420:
1421: default:
1.114 itojun 1422: /* XXX can't take &ipt->ipt_flg */
1423: code = (u_char *)&ipt->ipt_ptr -
1424: (u_char *)ip + 1;
1.1 cgd 1425: goto bad;
1426: }
1427: ntime = iptime();
1.107 thorpej 1428: cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1429: bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1,
1.1 cgd 1430: sizeof(n_time));
1431: ipt->ipt_ptr += sizeof(n_time);
1432: }
1433: }
1434: if (forward) {
1.26 thorpej 1435: if (ip_forwsrcrt == 0) {
1436: type = ICMP_UNREACH;
1437: code = ICMP_UNREACH_SRCFAIL;
1438: goto bad;
1439: }
1.1 cgd 1440: ip_forward(m, 1);
1441: return (1);
1.13 mycroft 1442: }
1443: return (0);
1.1 cgd 1444: bad:
1.13 mycroft 1445: icmp_error(m, type, code, 0, 0);
1446: ipstat.ips_badoptions++;
1.1 cgd 1447: return (1);
1448: }
1449:
1450: /*
1451: * Given address of next destination (final or next hop),
1452: * return internet address info of interface to be used to get there.
1453: */
1454: struct in_ifaddr *
1455: ip_rtaddr(dst)
1456: struct in_addr dst;
1457: {
1.109 augustss 1458: struct sockaddr_in *sin;
1.1 cgd 1459:
1.19 mycroft 1460: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1461:
1.35 mycroft 1462: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1463: if (ipforward_rt.ro_rt) {
1464: RTFREE(ipforward_rt.ro_rt);
1465: ipforward_rt.ro_rt = 0;
1466: }
1467: sin->sin_family = AF_INET;
1468: sin->sin_len = sizeof(*sin);
1469: sin->sin_addr = dst;
1470:
1471: rtalloc(&ipforward_rt);
1472: }
1473: if (ipforward_rt.ro_rt == 0)
1474: return ((struct in_ifaddr *)0);
1.19 mycroft 1475: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1476: }
1477:
1478: /*
1479: * Save incoming source route for use in replies,
1480: * to be picked up later by ip_srcroute if the receiver is interested.
1481: */
1.13 mycroft 1482: void
1.1 cgd 1483: save_rte(option, dst)
1484: u_char *option;
1485: struct in_addr dst;
1486: {
1487: unsigned olen;
1488:
1489: olen = option[IPOPT_OLEN];
1490: #ifdef DIAGNOSTIC
1491: if (ipprintfs)
1.39 christos 1492: printf("save_rte: olen %d\n", olen);
1.89 itojun 1493: #endif /* 0 */
1.1 cgd 1494: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1495: return;
1496: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1497: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1498: ip_srcrt.dst = dst;
1499: }
1500:
1501: /*
1502: * Retrieve incoming source route for use in replies,
1503: * in the same form used by setsockopt.
1504: * The first hop is placed before the options, will be removed later.
1505: */
1506: struct mbuf *
1507: ip_srcroute()
1508: {
1.109 augustss 1509: struct in_addr *p, *q;
1510: struct mbuf *m;
1.1 cgd 1511:
1512: if (ip_nhops == 0)
1513: return ((struct mbuf *)0);
1514: m = m_get(M_DONTWAIT, MT_SOOPTS);
1515: if (m == 0)
1516: return ((struct mbuf *)0);
1517:
1.164 matt 1518: MCLAIM(m, &inetdomain.dom_mowner);
1.13 mycroft 1519: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1520:
1521: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1522: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1523: OPTSIZ;
1524: #ifdef DIAGNOSTIC
1525: if (ipprintfs)
1.39 christos 1526: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1527: #endif
1528:
1529: /*
1530: * First save first hop for return route
1531: */
1532: p = &ip_srcrt.route[ip_nhops - 1];
1533: *(mtod(m, struct in_addr *)) = *p--;
1534: #ifdef DIAGNOSTIC
1535: if (ipprintfs)
1.39 christos 1536: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1537: #endif
1538:
1539: /*
1540: * Copy option fields and padding (nop) to mbuf.
1541: */
1542: ip_srcrt.nop = IPOPT_NOP;
1543: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1544: bcopy((caddr_t)&ip_srcrt.nop,
1545: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1546: q = (struct in_addr *)(mtod(m, caddr_t) +
1547: sizeof(struct in_addr) + OPTSIZ);
1548: #undef OPTSIZ
1549: /*
1550: * Record return path as an IP source route,
1551: * reversing the path (pointers are now aligned).
1552: */
1553: while (p >= ip_srcrt.route) {
1554: #ifdef DIAGNOSTIC
1555: if (ipprintfs)
1.39 christos 1556: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1557: #endif
1558: *q++ = *p--;
1559: }
1560: /*
1561: * Last hop goes to final destination.
1562: */
1563: *q = ip_srcrt.dst;
1564: #ifdef DIAGNOSTIC
1565: if (ipprintfs)
1.39 christos 1566: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1567: #endif
1568: return (m);
1569: }
1570:
1571: /*
1572: * Strip out IP options, at higher
1573: * level protocol in the kernel.
1574: * Second argument is buffer to which options
1575: * will be moved, and return value is their length.
1576: * XXX should be deleted; last arg currently ignored.
1577: */
1.8 mycroft 1578: void
1.1 cgd 1579: ip_stripoptions(m, mopt)
1.109 augustss 1580: struct mbuf *m;
1.1 cgd 1581: struct mbuf *mopt;
1582: {
1.109 augustss 1583: int i;
1.1 cgd 1584: struct ip *ip = mtod(m, struct ip *);
1.109 augustss 1585: caddr_t opts;
1.1 cgd 1586: int olen;
1587:
1.79 mycroft 1588: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1589: opts = (caddr_t)(ip + 1);
1590: i = m->m_len - (sizeof (struct ip) + olen);
1591: bcopy(opts + olen, opts, (unsigned)i);
1592: m->m_len -= olen;
1593: if (m->m_flags & M_PKTHDR)
1594: m->m_pkthdr.len -= olen;
1.155 itojun 1595: ip->ip_len = htons(ntohs(ip->ip_len) - olen);
1.79 mycroft 1596: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1597: }
1598:
1.139 matt 1599: const int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1600: 0, 0, 0, 0,
1601: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1602: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1603: EMSGSIZE, EHOSTUNREACH, 0, 0,
1604: 0, 0, 0, 0,
1605: ENOPROTOOPT
1606: };
1607:
1608: /*
1609: * Forward a packet. If some error occurs return the sender
1610: * an icmp packet. Note we can't always generate a meaningful
1611: * icmp message because icmp doesn't have a large enough repertoire
1612: * of codes and types.
1613: *
1614: * If not forwarding, just drop the packet. This could be confusing
1615: * if ipforwarding was zero but some routing protocol was advancing
1616: * us as a gateway to somewhere. However, we must let the routing
1617: * protocol deal with that.
1618: *
1619: * The srcrt parameter indicates whether the packet is being forwarded
1620: * via a source route.
1621: */
1.13 mycroft 1622: void
1.1 cgd 1623: ip_forward(m, srcrt)
1624: struct mbuf *m;
1625: int srcrt;
1626: {
1.109 augustss 1627: struct ip *ip = mtod(m, struct ip *);
1628: struct sockaddr_in *sin;
1629: struct rtentry *rt;
1.28 christos 1630: int error, type = 0, code = 0;
1.1 cgd 1631: struct mbuf *mcopy;
1.13 mycroft 1632: n_long dest;
1633: struct ifnet *destifp;
1.173 jonathan 1634: #if defined(IPSEC) || defined(FAST_IPSEC)
1.89 itojun 1635: struct ifnet dummyifp;
1636: #endif
1.164 matt 1637:
1638: /*
1639: * We are now in the output path.
1640: */
1641: MCLAIM(m, &ip_tx_mowner);
1.135 thorpej 1642:
1643: /*
1644: * Clear any in-bound checksum flags for this packet.
1645: */
1646: m->m_pkthdr.csum_flags = 0;
1.1 cgd 1647:
1.13 mycroft 1648: dest = 0;
1.1 cgd 1649: #ifdef DIAGNOSTIC
1650: if (ipprintfs)
1.70 thorpej 1651: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1652: ntohl(ip->ip_src.s_addr),
1653: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1654: #endif
1.93 sommerfe 1655: if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1.1 cgd 1656: ipstat.ips_cantforward++;
1657: m_freem(m);
1658: return;
1659: }
1660: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1661: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1662: return;
1663: }
1664: ip->ip_ttl -= IPTTLDEC;
1665:
1.19 mycroft 1666: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1667: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1668: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1669: if (ipforward_rt.ro_rt) {
1670: RTFREE(ipforward_rt.ro_rt);
1671: ipforward_rt.ro_rt = 0;
1672: }
1673: sin->sin_family = AF_INET;
1.35 mycroft 1674: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1675: sin->sin_addr = ip->ip_dst;
1676:
1677: rtalloc(&ipforward_rt);
1678: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1679: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1680: return;
1681: }
1682: rt = ipforward_rt.ro_rt;
1683: }
1684:
1685: /*
1.34 mycroft 1686: * Save at most 68 bytes of the packet in case
1.1 cgd 1687: * we need to generate an ICMP message to the src.
1.119 itojun 1688: * Pullup to avoid sharing mbuf cluster between m and mcopy.
1.1 cgd 1689: */
1.155 itojun 1690: mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1.119 itojun 1691: if (mcopy)
1692: mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1.1 cgd 1693:
1694: /*
1695: * If forwarding packet using same interface that it came in on,
1696: * perhaps should send a redirect to sender to shortcut a hop.
1697: * Only send redirect if source is sending directly to us,
1698: * and if packet was not source routed (or has any options).
1699: * Also, don't send redirect if forwarding using a default route
1700: * or a route modified by a redirect.
1701: */
1702: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1703: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1704: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1705: ipsendredirects && !srcrt) {
1.19 mycroft 1706: if (rt->rt_ifa &&
1707: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1708: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1709: if (rt->rt_flags & RTF_GATEWAY)
1710: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1711: else
1712: dest = ip->ip_dst.s_addr;
1713: /*
1714: * Router requirements says to only send host
1715: * redirects.
1716: */
1717: type = ICMP_REDIRECT;
1718: code = ICMP_REDIRECT_HOST;
1.1 cgd 1719: #ifdef DIAGNOSTIC
1.77 thorpej 1720: if (ipprintfs)
1721: printf("redirect (%d) to %x\n", code,
1722: (u_int32_t)dest);
1.1 cgd 1723: #endif
1724: }
1725: }
1726:
1.27 thorpej 1727: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1.173 jonathan 1728: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1.174 itojun 1729: (struct ip_moptions *)NULL, (struct socket *)NULL);
1.173 jonathan 1730:
1.1 cgd 1731: if (error)
1732: ipstat.ips_cantforward++;
1733: else {
1734: ipstat.ips_forward++;
1735: if (type)
1736: ipstat.ips_redirectsent++;
1737: else {
1.63 matt 1738: if (mcopy) {
1739: #ifdef GATEWAY
1.64 thorpej 1740: if (mcopy->m_flags & M_CANFASTFWD)
1741: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1742: #endif
1.1 cgd 1743: m_freem(mcopy);
1.63 matt 1744: }
1.1 cgd 1745: return;
1746: }
1747: }
1748: if (mcopy == NULL)
1749: return;
1.13 mycroft 1750: destifp = NULL;
1751:
1.1 cgd 1752: switch (error) {
1753:
1754: case 0: /* forwarded, but need redirect */
1755: /* type, code set above */
1756: break;
1757:
1758: case ENETUNREACH: /* shouldn't happen, checked above */
1759: case EHOSTUNREACH:
1760: case ENETDOWN:
1761: case EHOSTDOWN:
1762: default:
1763: type = ICMP_UNREACH;
1764: code = ICMP_UNREACH_HOST;
1765: break;
1766:
1767: case EMSGSIZE:
1768: type = ICMP_UNREACH;
1769: code = ICMP_UNREACH_NEEDFRAG;
1.173 jonathan 1770: #if !defined(IPSEC) && !defined(FAST_IPSEC)
1.13 mycroft 1771: if (ipforward_rt.ro_rt)
1772: destifp = ipforward_rt.ro_rt->rt_ifp;
1.89 itojun 1773: #else
1774: /*
1775: * If the packet is routed over IPsec tunnel, tell the
1776: * originator the tunnel MTU.
1777: * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1778: * XXX quickhack!!!
1779: */
1780: if (ipforward_rt.ro_rt) {
1781: struct secpolicy *sp;
1782: int ipsecerror;
1.95 itojun 1783: size_t ipsechdr;
1.89 itojun 1784: struct route *ro;
1785:
1786: sp = ipsec4_getpolicybyaddr(mcopy,
1.170 itojun 1787: IPSEC_DIR_OUTBOUND, IP_FORWARDING,
1788: &ipsecerror);
1.89 itojun 1789:
1790: if (sp == NULL)
1791: destifp = ipforward_rt.ro_rt->rt_ifp;
1792: else {
1793: /* count IPsec header size */
1.95 itojun 1794: ipsechdr = ipsec4_hdrsiz(mcopy,
1.170 itojun 1795: IPSEC_DIR_OUTBOUND, NULL);
1.89 itojun 1796:
1797: /*
1798: * find the correct route for outer IPv4
1799: * header, compute tunnel MTU.
1800: *
1801: * XXX BUG ALERT
1802: * The "dummyifp" code relies upon the fact
1803: * that icmp_error() touches only ifp->if_mtu.
1804: */
1805: /*XXX*/
1806: destifp = NULL;
1807: if (sp->req != NULL
1.95 itojun 1808: && sp->req->sav != NULL
1809: && sp->req->sav->sah != NULL) {
1810: ro = &sp->req->sav->sah->sa_route;
1.89 itojun 1811: if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1812: dummyifp.if_mtu =
1.151 itojun 1813: ro->ro_rt->rt_rmx.rmx_mtu ?
1814: ro->ro_rt->rt_rmx.rmx_mtu :
1.89 itojun 1815: ro->ro_rt->rt_ifp->if_mtu;
1816: dummyifp.if_mtu -= ipsechdr;
1817: destifp = &dummyifp;
1818: }
1819: }
1820:
1.173 jonathan 1821: #ifdef IPSEC
1.89 itojun 1822: key_freesp(sp);
1.173 jonathan 1823: #else
1824: KEY_FREESP(&sp);
1825: #endif
1.89 itojun 1826: }
1827: }
1828: #endif /*IPSEC*/
1.1 cgd 1829: ipstat.ips_cantfrag++;
1830: break;
1831:
1832: case ENOBUFS:
1.143 itojun 1833: #if 1
1834: /*
1835: * a router should not generate ICMP_SOURCEQUENCH as
1836: * required in RFC1812 Requirements for IP Version 4 Routers.
1837: * source quench could be a big problem under DoS attacks,
1.149 wiz 1838: * or if the underlying interface is rate-limited.
1.143 itojun 1839: */
1840: if (mcopy)
1841: m_freem(mcopy);
1842: return;
1843: #else
1.1 cgd 1844: type = ICMP_SOURCEQUENCH;
1845: code = 0;
1846: break;
1.143 itojun 1847: #endif
1.1 cgd 1848: }
1.13 mycroft 1849: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1850: }
1851:
1852: void
1853: ip_savecontrol(inp, mp, ip, m)
1.109 augustss 1854: struct inpcb *inp;
1855: struct mbuf **mp;
1856: struct ip *ip;
1857: struct mbuf *m;
1.44 thorpej 1858: {
1859:
1860: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1861: struct timeval tv;
1862:
1863: microtime(&tv);
1864: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1865: SCM_TIMESTAMP, SOL_SOCKET);
1866: if (*mp)
1867: mp = &(*mp)->m_next;
1868: }
1869: if (inp->inp_flags & INP_RECVDSTADDR) {
1870: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1871: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1872: if (*mp)
1873: mp = &(*mp)->m_next;
1874: }
1875: #ifdef notyet
1876: /*
1877: * XXX
1878: * Moving these out of udp_input() made them even more broken
1879: * than they already were.
1880: * - fenner@parc.xerox.com
1881: */
1882: /* options were tossed already */
1883: if (inp->inp_flags & INP_RECVOPTS) {
1884: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1885: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1886: if (*mp)
1887: mp = &(*mp)->m_next;
1888: }
1889: /* ip_srcroute doesn't do what we want here, need to fix */
1890: if (inp->inp_flags & INP_RECVRETOPTS) {
1891: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1892: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1893: if (*mp)
1894: mp = &(*mp)->m_next;
1895: }
1896: #endif
1897: if (inp->inp_flags & INP_RECVIF) {
1898: struct sockaddr_dl sdl;
1899:
1900: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1901: sdl.sdl_family = AF_LINK;
1902: sdl.sdl_index = m->m_pkthdr.rcvif ?
1903: m->m_pkthdr.rcvif->if_index : 0;
1904: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1905: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1906: IP_RECVIF, IPPROTO_IP);
1907: if (*mp)
1908: mp = &(*mp)->m_next;
1909: }
1.13 mycroft 1910: }
1911:
1912: int
1913: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1914: int *name;
1915: u_int namelen;
1916: void *oldp;
1917: size_t *oldlenp;
1918: void *newp;
1919: size_t newlen;
1920: {
1.88 sommerfe 1921: extern int subnetsarelocal, hostzeroisbroadcast;
1.52 thorpej 1922:
1.54 lukem 1923: int error, old;
1924:
1.180 ! jonathan 1925: /* All sysctl names (except ifq.*) at this level are terminal. */
! 1926: if ((namelen != 1) && !(namelen == 2 && name[0] == IPCTL_IFQ))
! 1927: return (ENOTDIR);
1.13 mycroft 1928:
1929: switch (name[0]) {
1930: case IPCTL_FORWARDING:
1931: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1932: case IPCTL_SENDREDIRECTS:
1933: return (sysctl_int(oldp, oldlenp, newp, newlen,
1934: &ipsendredirects));
1935: case IPCTL_DEFTTL:
1936: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1937: #ifdef notyet
1938: case IPCTL_DEFMTU:
1939: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1940: #endif
1.26 thorpej 1941: case IPCTL_FORWSRCRT:
1.47 cjs 1942: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1943: if (securelevel > 0)
1.46 cjs 1944: return (sysctl_rdint(oldp, oldlenp, newp,
1945: ip_forwsrcrt));
1946: else
1947: return (sysctl_int(oldp, oldlenp, newp, newlen,
1948: &ip_forwsrcrt));
1.27 thorpej 1949: case IPCTL_DIRECTEDBCAST:
1950: return (sysctl_int(oldp, oldlenp, newp, newlen,
1951: &ip_directedbcast));
1.47 cjs 1952: case IPCTL_ALLOWSRCRT:
1953: return (sysctl_int(oldp, oldlenp, newp, newlen,
1954: &ip_allowsrcrt));
1.52 thorpej 1955: case IPCTL_SUBNETSARELOCAL:
1956: return (sysctl_int(oldp, oldlenp, newp, newlen,
1957: &subnetsarelocal));
1.53 kml 1958: case IPCTL_MTUDISC:
1.60 kml 1959: error = sysctl_int(oldp, oldlenp, newp, newlen,
1960: &ip_mtudisc);
1.163 itojun 1961: if (error == 0 && ip_mtudisc == 0)
1962: rt_timer_queue_remove_all(ip_mtudisc_timeout_q, TRUE);
1.60 kml 1963: return error;
1.54 lukem 1964: case IPCTL_ANONPORTMIN:
1965: old = anonportmin;
1966: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1.118 itojun 1967: if (anonportmin >= anonportmax || anonportmin < 0
1968: || anonportmin > 65535
1.54 lukem 1969: #ifndef IPNOPRIVPORTS
1970: || anonportmin < IPPORT_RESERVED
1971: #endif
1972: ) {
1973: anonportmin = old;
1974: return (EINVAL);
1975: }
1976: return (error);
1977: case IPCTL_ANONPORTMAX:
1978: old = anonportmax;
1979: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1.118 itojun 1980: if (anonportmin >= anonportmax || anonportmax < 0
1981: || anonportmax > 65535
1.54 lukem 1982: #ifndef IPNOPRIVPORTS
1983: || anonportmax < IPPORT_RESERVED
1984: #endif
1985: ) {
1986: anonportmax = old;
1987: return (EINVAL);
1988: }
1.60 kml 1989: return (error);
1990: case IPCTL_MTUDISCTIMEOUT:
1.158 itojun 1991: old = ip_mtudisc_timeout;
1.60 kml 1992: error = sysctl_int(oldp, oldlenp, newp, newlen,
1993: &ip_mtudisc_timeout);
1.158 itojun 1994: if (ip_mtudisc_timeout < 0) {
1995: ip_mtudisc_timeout = old;
1.156 itojun 1996: return (EINVAL);
1.158 itojun 1997: }
1.163 itojun 1998: if (error == 0)
1.162 itojun 1999: rt_timer_queue_change(ip_mtudisc_timeout_q,
2000: ip_mtudisc_timeout);
1.54 lukem 2001: return (error);
1.65 matt 2002: #ifdef GATEWAY
2003: case IPCTL_MAXFLOWS:
1.67 thorpej 2004: {
2005: int s;
2006:
1.65 matt 2007: error = sysctl_int(oldp, oldlenp, newp, newlen,
2008: &ip_maxflows);
1.67 thorpej 2009: s = splsoftnet();
1.65 matt 2010: ipflow_reap(0);
1.67 thorpej 2011: splx(s);
1.65 matt 2012: return (error);
1.67 thorpej 2013: }
1.89 itojun 2014: #endif
1.90 itojun 2015: case IPCTL_HOSTZEROBROADCAST:
2016: return (sysctl_int(oldp, oldlenp, newp, newlen,
2017: &hostzeroisbroadcast));
1.89 itojun 2018: #if NGIF > 0
2019: case IPCTL_GIF_TTL:
1.157 itojun 2020: return (sysctl_int(oldp, oldlenp, newp, newlen,
1.90 itojun 2021: &ip_gif_ttl));
1.144 martin 2022: #endif
2023:
2024: #if NGRE > 0
2025: case IPCTL_GRE_TTL:
1.157 itojun 2026: return (sysctl_int(oldp, oldlenp, newp, newlen,
1.144 martin 2027: &ip_gre_ttl));
1.117 tron 2028: #endif
2029:
2030: #ifndef IPNOPRIVPORTS
2031: case IPCTL_LOWPORTMIN:
2032: old = lowportmin;
2033: error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmin);
2034: if (lowportmin >= lowportmax
2035: || lowportmin > IPPORT_RESERVEDMAX
2036: || lowportmin < IPPORT_RESERVEDMIN
2037: ) {
2038: lowportmin = old;
2039: return (EINVAL);
2040: }
2041: return (error);
2042: case IPCTL_LOWPORTMAX:
2043: old = lowportmax;
2044: error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmax);
2045: if (lowportmin >= lowportmax
2046: || lowportmax > IPPORT_RESERVEDMAX
2047: || lowportmax < IPPORT_RESERVEDMIN
2048: ) {
2049: lowportmax = old;
2050: return (EINVAL);
2051: }
2052: return (error);
1.65 matt 2053: #endif
1.131 itojun 2054:
2055: case IPCTL_MAXFRAGPACKETS:
2056: return (sysctl_int(oldp, oldlenp, newp, newlen,
2057: &ip_maxfragpackets));
1.88 sommerfe 2058:
1.165 christos 2059: case IPCTL_CHECKINTERFACE:
2060: return (sysctl_int(oldp, oldlenp, newp, newlen,
2061: &ip_checkinterface));
1.180 ! jonathan 2062: case IPCTL_IFQ:
! 2063: return (sysctl_ifq(name+1, namelen-1,
! 2064: oldp, oldlenp, newp, newlen,
! 2065: &ipintrq));
! 2066:
1.13 mycroft 2067: default:
2068: return (EOPNOTSUPP);
2069: }
2070: /* NOTREACHED */
1.1 cgd 2071: }
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