Annotation of src/sys/netinet/ip_input.c, Revision 1.86
1.86 ! thorpej 1: /* $NetBSD: ip_input.c,v 1.85 1999/05/03 21:14:47 hwr Exp $ */
1.76 thorpej 2:
3: /*-
4: * Copyright (c) 1998 The NetBSD Foundation, Inc.
5: * All rights reserved.
6: *
7: * This code is derived from software contributed to The NetBSD Foundation
8: * by Public Access Networks Corporation ("Panix"). It was developed under
9: * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
10: *
11: * Redistribution and use in source and binary forms, with or without
12: * modification, are permitted provided that the following conditions
13: * are met:
14: * 1. Redistributions of source code must retain the above copyright
15: * notice, this list of conditions and the following disclaimer.
16: * 2. Redistributions in binary form must reproduce the above copyright
17: * notice, this list of conditions and the following disclaimer in the
18: * documentation and/or other materials provided with the distribution.
19: * 3. All advertising materials mentioning features or use of this software
20: * must display the following acknowledgement:
21: * This product includes software developed by the NetBSD
22: * Foundation, Inc. and its contributors.
23: * 4. Neither the name of The NetBSD Foundation nor the names of its
24: * contributors may be used to endorse or promote products derived
25: * from this software without specific prior written permission.
26: *
27: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37: * POSSIBILITY OF SUCH DAMAGE.
38: */
1.14 cgd 39:
1.1 cgd 40: /*
1.13 mycroft 41: * Copyright (c) 1982, 1986, 1988, 1993
42: * The Regents of the University of California. All rights reserved.
1.1 cgd 43: *
44: * Redistribution and use in source and binary forms, with or without
45: * modification, are permitted provided that the following conditions
46: * are met:
47: * 1. Redistributions of source code must retain the above copyright
48: * notice, this list of conditions and the following disclaimer.
49: * 2. Redistributions in binary form must reproduce the above copyright
50: * notice, this list of conditions and the following disclaimer in the
51: * documentation and/or other materials provided with the distribution.
52: * 3. All advertising materials mentioning features or use of this software
53: * must display the following acknowledgement:
54: * This product includes software developed by the University of
55: * California, Berkeley and its contributors.
56: * 4. Neither the name of the University nor the names of its contributors
57: * may be used to endorse or promote products derived from this software
58: * without specific prior written permission.
59: *
60: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
61: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
62: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
63: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
64: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
65: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
66: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
67: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
68: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
69: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
70: * SUCH DAMAGE.
71: *
1.14 cgd 72: * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
1.1 cgd 73: */
1.55 scottr 74:
1.62 matt 75: #include "opt_gateway.h"
1.69 mrg 76: #include "opt_pfil_hooks.h"
1.55 scottr 77: #include "opt_mrouting.h"
1.1 cgd 78:
1.5 mycroft 79: #include <sys/param.h>
80: #include <sys/systm.h>
81: #include <sys/malloc.h>
82: #include <sys/mbuf.h>
83: #include <sys/domain.h>
84: #include <sys/protosw.h>
85: #include <sys/socket.h>
1.44 thorpej 86: #include <sys/socketvar.h>
1.5 mycroft 87: #include <sys/errno.h>
88: #include <sys/time.h>
89: #include <sys/kernel.h>
1.28 christos 90: #include <sys/proc.h>
1.72 thorpej 91: #include <sys/pool.h>
1.28 christos 92:
93: #include <vm/vm.h>
94: #include <sys/sysctl.h>
1.1 cgd 95:
1.5 mycroft 96: #include <net/if.h>
1.44 thorpej 97: #include <net/if_dl.h>
1.5 mycroft 98: #include <net/route.h>
1.45 mrg 99: #include <net/pfil.h>
1.1 cgd 100:
1.5 mycroft 101: #include <netinet/in.h>
102: #include <netinet/in_systm.h>
103: #include <netinet/ip.h>
104: #include <netinet/in_pcb.h>
105: #include <netinet/in_var.h>
106: #include <netinet/ip_var.h>
107: #include <netinet/ip_icmp.h>
1.44 thorpej 108:
1.1 cgd 109: #ifndef IPFORWARDING
110: #ifdef GATEWAY
111: #define IPFORWARDING 1 /* forward IP packets not for us */
112: #else /* GATEWAY */
113: #define IPFORWARDING 0 /* don't forward IP packets not for us */
114: #endif /* GATEWAY */
115: #endif /* IPFORWARDING */
116: #ifndef IPSENDREDIRECTS
117: #define IPSENDREDIRECTS 1
118: #endif
1.26 thorpej 119: #ifndef IPFORWSRCRT
1.47 cjs 120: #define IPFORWSRCRT 1 /* forward source-routed packets */
121: #endif
122: #ifndef IPALLOWSRCRT
1.48 mrg 123: #define IPALLOWSRCRT 1 /* allow source-routed packets */
1.26 thorpej 124: #endif
1.53 kml 125: #ifndef IPMTUDISC
126: #define IPMTUDISC 0
127: #endif
1.60 kml 128: #ifndef IPMTUDISCTIMEOUT
1.61 kml 129: #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
1.60 kml 130: #endif
1.53 kml 131:
1.27 thorpej 132: /*
133: * Note: DIRECTED_BROADCAST is handled this way so that previous
134: * configuration using this option will Just Work.
135: */
136: #ifndef IPDIRECTEDBCAST
137: #ifdef DIRECTED_BROADCAST
138: #define IPDIRECTEDBCAST 1
139: #else
140: #define IPDIRECTEDBCAST 0
141: #endif /* DIRECTED_BROADCAST */
142: #endif /* IPDIRECTEDBCAST */
1.1 cgd 143: int ipforwarding = IPFORWARDING;
144: int ipsendredirects = IPSENDREDIRECTS;
1.13 mycroft 145: int ip_defttl = IPDEFTTL;
1.26 thorpej 146: int ip_forwsrcrt = IPFORWSRCRT;
1.27 thorpej 147: int ip_directedbcast = IPDIRECTEDBCAST;
1.47 cjs 148: int ip_allowsrcrt = IPALLOWSRCRT;
1.53 kml 149: int ip_mtudisc = IPMTUDISC;
1.60 kml 150: u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1 cgd 151: #ifdef DIAGNOSTIC
152: int ipprintfs = 0;
153: #endif
154:
1.60 kml 155: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
156:
1.1 cgd 157: extern struct domain inetdomain;
158: extern struct protosw inetsw[];
159: u_char ip_protox[IPPROTO_MAX];
160: int ipqmaxlen = IFQ_MAXLEN;
1.22 mycroft 161: struct in_ifaddrhead in_ifaddr;
1.57 tls 162: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.13 mycroft 163: struct ifqueue ipintrq;
1.63 matt 164: struct ipstat ipstat;
165: u_int16_t ip_id;
166: int ip_defttl;
1.75 thorpej 167:
1.63 matt 168: struct ipqhead ipq;
1.75 thorpej 169: int ipq_locked;
170:
171: static __inline int ipq_lock_try __P((void));
172: static __inline void ipq_unlock __P((void));
173:
174: static __inline int
175: ipq_lock_try()
176: {
177: int s;
178:
179: s = splimp();
180: if (ipq_locked) {
181: splx(s);
182: return (0);
183: }
184: ipq_locked = 1;
185: splx(s);
186: return (1);
187: }
188:
189: static __inline void
190: ipq_unlock()
191: {
192: int s;
193:
194: s = splimp();
195: ipq_locked = 0;
196: splx(s);
197: }
198:
199: #ifdef DIAGNOSTIC
200: #define IPQ_LOCK() \
201: do { \
202: if (ipq_lock_try() == 0) { \
203: printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
204: panic("ipq_lock"); \
205: } \
206: } while (0)
207: #define IPQ_LOCK_CHECK() \
208: do { \
209: if (ipq_locked == 0) { \
210: printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
211: panic("ipq lock check"); \
212: } \
213: } while (0)
214: #else
215: #define IPQ_LOCK() (void) ipq_lock_try()
216: #define IPQ_LOCK_CHECK() /* nothing */
217: #endif
218:
219: #define IPQ_UNLOCK() ipq_unlock()
1.1 cgd 220:
1.72 thorpej 221: struct pool ipqent_pool;
222:
1.1 cgd 223: /*
224: * We need to save the IP options in case a protocol wants to respond
225: * to an incoming packet over the same route if the packet got here
226: * using IP source routing. This allows connection establishment and
227: * maintenance when the remote end is on a network that is not known
228: * to us.
229: */
230: int ip_nhops = 0;
231: static struct ip_srcrt {
232: struct in_addr dst; /* final destination */
233: char nop; /* one NOP to align */
234: char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
235: struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
236: } ip_srcrt;
237:
1.13 mycroft 238: static void save_rte __P((u_char *, struct in_addr));
1.35 mycroft 239:
1.1 cgd 240: /*
241: * IP initialization: fill in IP protocol switch table.
242: * All protocols not implemented in kernel go to raw IP protocol handler.
243: */
1.8 mycroft 244: void
1.1 cgd 245: ip_init()
246: {
247: register struct protosw *pr;
248: register int i;
249:
1.72 thorpej 250: pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
251: 0, NULL, NULL, M_IPQ);
252:
1.1 cgd 253: pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
254: if (pr == 0)
255: panic("ip_init");
256: for (i = 0; i < IPPROTO_MAX; i++)
257: ip_protox[i] = pr - inetsw;
258: for (pr = inetdomain.dom_protosw;
259: pr < inetdomain.dom_protoswNPROTOSW; pr++)
260: if (pr->pr_domain->dom_family == PF_INET &&
261: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
262: ip_protox[pr->pr_protocol] = pr - inetsw;
1.25 cgd 263: LIST_INIT(&ipq);
1.1 cgd 264: ip_id = time.tv_sec & 0xffff;
265: ipintrq.ifq_maxlen = ipqmaxlen;
1.22 mycroft 266: TAILQ_INIT(&in_ifaddr);
1.57 tls 267: in_ifaddrhashtbl =
268: hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash);
1.60 kml 269: if (ip_mtudisc != 0)
270: ip_mtudisc_timeout_q =
271: rt_timer_queue_create(ip_mtudisc_timeout);
1.73 thorpej 272: #ifdef GATEWAY
273: ipflow_init();
274: #endif
1.1 cgd 275: }
276:
277: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
278: struct route ipforward_rt;
279:
280: /*
281: * Ip input routine. Checksum and byte swap header. If fragmented
282: * try to reassemble. Process options. Pass to next level.
283: */
1.8 mycroft 284: void
1.1 cgd 285: ipintr()
286: {
1.33 mrg 287: register struct ip *ip = NULL;
1.1 cgd 288: register struct mbuf *m;
289: register struct ipq *fp;
290: register struct in_ifaddr *ia;
1.57 tls 291: register struct ifaddr *ifa;
1.25 cgd 292: struct ipqent *ipqe;
1.35 mycroft 293: int hlen = 0, mff, len, s;
1.36 mrg 294: #ifdef PFIL_HOOKS
1.33 mrg 295: struct packet_filter_hook *pfh;
296: struct mbuf *m0;
1.43 mrg 297: int rv;
1.36 mrg 298: #endif /* PFIL_HOOKS */
1.1 cgd 299:
300: next:
301: /*
302: * Get next datagram off input queue and get IP header
303: * in first mbuf.
304: */
305: s = splimp();
306: IF_DEQUEUE(&ipintrq, m);
307: splx(s);
1.13 mycroft 308: if (m == 0)
1.1 cgd 309: return;
310: #ifdef DIAGNOSTIC
311: if ((m->m_flags & M_PKTHDR) == 0)
312: panic("ipintr no HDR");
313: #endif
314: /*
315: * If no IP addresses have been set yet but the interfaces
316: * are receiving, can't do anything with incoming packets yet.
317: */
1.22 mycroft 318: if (in_ifaddr.tqh_first == 0)
1.1 cgd 319: goto bad;
320: ipstat.ips_total++;
321: if (m->m_len < sizeof (struct ip) &&
322: (m = m_pullup(m, sizeof (struct ip))) == 0) {
323: ipstat.ips_toosmall++;
324: goto next;
325: }
326: ip = mtod(m, struct ip *);
1.13 mycroft 327: if (ip->ip_v != IPVERSION) {
328: ipstat.ips_badvers++;
329: goto bad;
330: }
1.1 cgd 331: hlen = ip->ip_hl << 2;
332: if (hlen < sizeof(struct ip)) { /* minimum header length */
333: ipstat.ips_badhlen++;
334: goto bad;
335: }
336: if (hlen > m->m_len) {
337: if ((m = m_pullup(m, hlen)) == 0) {
338: ipstat.ips_badhlen++;
339: goto next;
340: }
341: ip = mtod(m, struct ip *);
342: }
1.85 hwr 343: /*
344: * we drop packets that have a multicast address as source
345: * as wanted by rfc 1112
346: */
347: if (IN_MULTICAST(ip->ip_src.s_addr)) {
348: ipstat.ips_odropped++;
349: goto bad;
350: }
351:
1.78 mycroft 352: if (in_cksum(m, hlen) != 0) {
1.1 cgd 353: ipstat.ips_badsum++;
354: goto bad;
355: }
356:
357: /*
358: * Convert fields to host representation.
359: */
360: NTOHS(ip->ip_len);
361: NTOHS(ip->ip_off);
1.35 mycroft 362: len = ip->ip_len;
1.81 proff 363:
364: /*
365: * Check for additional length bogosity
366: */
1.84 proff 367: if (len < hlen) {
1.81 proff 368: ipstat.ips_badlen++;
369: goto bad;
370: }
1.1 cgd 371:
372: /*
373: * Check that the amount of data in the buffers
374: * is as at least much as the IP header would have us expect.
375: * Trim mbufs if longer than we expect.
376: * Drop packet if shorter than we expect.
377: */
1.35 mycroft 378: if (m->m_pkthdr.len < len) {
1.1 cgd 379: ipstat.ips_tooshort++;
380: goto bad;
381: }
1.35 mycroft 382: if (m->m_pkthdr.len > len) {
1.1 cgd 383: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 384: m->m_len = len;
385: m->m_pkthdr.len = len;
1.1 cgd 386: } else
1.35 mycroft 387: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 388: }
389:
1.64 thorpej 390: /*
391: * Assume that we can create a fast-forward IP flow entry
392: * based on this packet.
393: */
394: m->m_flags |= M_CANFASTFWD;
395:
1.36 mrg 396: #ifdef PFIL_HOOKS
1.33 mrg 397: /*
1.64 thorpej 398: * Run through list of hooks for input packets. If there are any
399: * filters which require that additional packets in the flow are
400: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
401: * Note that filters must _never_ set this flag, as another filter
402: * in the list may have previously cleared it.
1.33 mrg 403: */
404: m0 = m;
1.59 mrg 405: for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33 mrg 406: if (pfh->pfil_func) {
1.43 mrg 407: rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
408: if (rv)
1.40 veego 409: goto next;
1.68 sommerfe 410: m = m0;
411: if (m == NULL)
412: goto next;
413: ip = mtod(m, struct ip *);
1.33 mrg 414: }
1.36 mrg 415: #endif /* PFIL_HOOKS */
1.33 mrg 416:
1.1 cgd 417: /*
418: * Process options and, if not destined for us,
419: * ship it on. ip_dooptions returns 1 when an
420: * error was detected (causing an icmp message
421: * to be sent and the original packet to be freed).
422: */
423: ip_nhops = 0; /* for source routed packets */
424: if (hlen > sizeof (struct ip) && ip_dooptions(m))
425: goto next;
426:
427: /*
428: * Check our list of addresses, to see if the packet is for us.
429: */
1.57 tls 430: INADDR_TO_IA(ip->ip_dst, ia);
1.86 ! thorpej 431: if (ia != NULL)
! 432: goto ours;
1.57 tls 433: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
434: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
435: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
436: if (ifa->ifa_addr->sa_family != AF_INET) continue;
437: ia = ifatoia(ifa);
1.35 mycroft 438: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
439: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 440: /*
441: * Look for all-0's host part (old broadcast addr),
442: * either for subnet or net.
443: */
444: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 445: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 446: goto ours;
1.57 tls 447: /*
448: * An interface with IP address zero accepts
449: * all packets that arrive on that interface.
450: */
451: if (in_nullhost(ia->ia_addr.sin_addr))
452: goto ours;
1.1 cgd 453: }
454: }
1.18 mycroft 455: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 456: struct in_multi *inm;
457: #ifdef MROUTING
458: extern struct socket *ip_mrouter;
1.10 brezak 459:
460: if (m->m_flags & M_EXT) {
461: if ((m = m_pullup(m, hlen)) == 0) {
462: ipstat.ips_toosmall++;
463: goto next;
464: }
465: ip = mtod(m, struct ip *);
466: }
1.4 hpeyerl 467:
468: if (ip_mrouter) {
469: /*
470: * If we are acting as a multicast router, all
471: * incoming multicast packets are passed to the
472: * kernel-level multicast forwarding function.
473: * The packet is returned (relatively) intact; if
474: * ip_mforward() returns a non-zero value, the packet
475: * must be discarded, else it may be accepted below.
476: *
477: * (The IP ident field is put in the same byte order
478: * as expected when ip_mforward() is called from
479: * ip_output().)
480: */
1.13 mycroft 481: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
482: ipstat.ips_cantforward++;
1.4 hpeyerl 483: m_freem(m);
484: goto next;
485: }
486:
487: /*
488: * The process-level routing demon needs to receive
489: * all multicast IGMP packets, whether or not this
490: * host belongs to their destination groups.
491: */
492: if (ip->ip_p == IPPROTO_IGMP)
493: goto ours;
1.13 mycroft 494: ipstat.ips_forward++;
1.4 hpeyerl 495: }
496: #endif
497: /*
498: * See if we belong to the destination multicast group on the
499: * arrival interface.
500: */
501: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
502: if (inm == NULL) {
1.13 mycroft 503: ipstat.ips_cantforward++;
1.4 hpeyerl 504: m_freem(m);
505: goto next;
506: }
507: goto ours;
508: }
1.19 mycroft 509: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 510: in_nullhost(ip->ip_dst))
1.1 cgd 511: goto ours;
512:
513: /*
514: * Not for us; forward if possible and desirable.
515: */
516: if (ipforwarding == 0) {
517: ipstat.ips_cantforward++;
518: m_freem(m);
519: } else
520: ip_forward(m, 0);
521: goto next;
522:
523: ours:
524: /*
525: * If offset or IP_MF are set, must reassemble.
526: * Otherwise, nothing need be done.
527: * (We could look in the reassembly queue to see
528: * if the packet was previously fragmented,
529: * but it's not worth the time; just let them time out.)
530: */
1.37 perry 531: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 532: /*
533: * Look for queue of fragments
534: * of this datagram.
535: */
1.75 thorpej 536: IPQ_LOCK();
1.25 cgd 537: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 538: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 539: in_hosteq(ip->ip_src, fp->ipq_src) &&
540: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 541: ip->ip_p == fp->ipq_p)
542: goto found;
543: fp = 0;
544: found:
545:
546: /*
547: * Adjust ip_len to not reflect header,
1.25 cgd 548: * set ipqe_mff if more fragments are expected,
1.1 cgd 549: * convert offset of this to bytes.
550: */
551: ip->ip_len -= hlen;
1.25 cgd 552: mff = (ip->ip_off & IP_MF) != 0;
553: if (mff) {
1.16 cgd 554: /*
555: * Make sure that fragments have a data length
556: * that's a non-zero multiple of 8 bytes.
557: */
1.17 cgd 558: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 559: ipstat.ips_badfrags++;
1.75 thorpej 560: IPQ_UNLOCK();
1.16 cgd 561: goto bad;
562: }
563: }
1.1 cgd 564: ip->ip_off <<= 3;
565:
566: /*
567: * If datagram marked as having more fragments
568: * or if this is not the first fragment,
569: * attempt reassembly; if it succeeds, proceed.
570: */
1.25 cgd 571: if (mff || ip->ip_off) {
1.1 cgd 572: ipstat.ips_fragments++;
1.72 thorpej 573: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 574: if (ipqe == NULL) {
575: ipstat.ips_rcvmemdrop++;
1.75 thorpej 576: IPQ_UNLOCK();
1.25 cgd 577: goto bad;
578: }
579: ipqe->ipqe_mff = mff;
1.50 thorpej 580: ipqe->ipqe_m = m;
1.25 cgd 581: ipqe->ipqe_ip = ip;
1.50 thorpej 582: m = ip_reass(ipqe, fp);
1.75 thorpej 583: if (m == 0) {
584: IPQ_UNLOCK();
1.1 cgd 585: goto next;
1.75 thorpej 586: }
1.13 mycroft 587: ipstat.ips_reassembled++;
1.50 thorpej 588: ip = mtod(m, struct ip *);
1.74 thorpej 589: hlen = ip->ip_hl << 2;
1.79 mycroft 590: ip->ip_len += hlen;
1.1 cgd 591: } else
592: if (fp)
593: ip_freef(fp);
1.75 thorpej 594: IPQ_UNLOCK();
1.79 mycroft 595: }
1.1 cgd 596:
597: /*
598: * Switch out to protocol's input routine.
599: */
1.82 aidan 600: #if IFA_STATS
601: ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
602: #endif
1.1 cgd 603: ipstat.ips_delivered++;
604: (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
605: goto next;
606: bad:
607: m_freem(m);
608: goto next;
609: }
610:
611: /*
612: * Take incoming datagram fragment and try to
613: * reassemble it into whole datagram. If a chain for
614: * reassembly of this datagram already exists, then it
615: * is given as fp; otherwise have to make a chain.
616: */
1.50 thorpej 617: struct mbuf *
1.25 cgd 618: ip_reass(ipqe, fp)
619: register struct ipqent *ipqe;
1.1 cgd 620: register struct ipq *fp;
621: {
1.50 thorpej 622: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 623: register struct ipqent *nq, *p, *q;
624: struct ip *ip;
1.1 cgd 625: struct mbuf *t;
1.25 cgd 626: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 627: int i, next;
628:
1.75 thorpej 629: IPQ_LOCK_CHECK();
630:
1.1 cgd 631: /*
632: * Presence of header sizes in mbufs
633: * would confuse code below.
634: */
635: m->m_data += hlen;
636: m->m_len -= hlen;
637:
638: /*
639: * If first fragment to arrive, create a reassembly queue.
640: */
641: if (fp == 0) {
1.50 thorpej 642: MALLOC(fp, struct ipq *, sizeof (struct ipq),
643: M_FTABLE, M_NOWAIT);
644: if (fp == NULL)
1.1 cgd 645: goto dropfrag;
1.25 cgd 646: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 647: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 648: fp->ipq_p = ipqe->ipqe_ip->ip_p;
649: fp->ipq_id = ipqe->ipqe_ip->ip_id;
650: LIST_INIT(&fp->ipq_fragq);
651: fp->ipq_src = ipqe->ipqe_ip->ip_src;
652: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
653: p = NULL;
1.1 cgd 654: goto insert;
655: }
656:
657: /*
658: * Find a segment which begins after this one does.
659: */
1.25 cgd 660: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
661: p = q, q = q->ipqe_q.le_next)
662: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 663: break;
664:
665: /*
666: * If there is a preceding segment, it may provide some of
667: * our data already. If so, drop the data from the incoming
668: * segment. If it provides all of our data, drop us.
669: */
1.25 cgd 670: if (p != NULL) {
671: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
672: ipqe->ipqe_ip->ip_off;
1.1 cgd 673: if (i > 0) {
1.25 cgd 674: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 675: goto dropfrag;
1.50 thorpej 676: m_adj(ipqe->ipqe_m, i);
1.25 cgd 677: ipqe->ipqe_ip->ip_off += i;
678: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 679: }
680: }
681:
682: /*
683: * While we overlap succeeding segments trim them or,
684: * if they are completely covered, dequeue them.
685: */
1.25 cgd 686: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
687: q->ipqe_ip->ip_off; q = nq) {
688: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
689: q->ipqe_ip->ip_off;
690: if (i < q->ipqe_ip->ip_len) {
691: q->ipqe_ip->ip_len -= i;
692: q->ipqe_ip->ip_off += i;
1.50 thorpej 693: m_adj(q->ipqe_m, i);
1.1 cgd 694: break;
695: }
1.25 cgd 696: nq = q->ipqe_q.le_next;
1.50 thorpej 697: m_freem(q->ipqe_m);
1.25 cgd 698: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 699: pool_put(&ipqent_pool, q);
1.1 cgd 700: }
701:
702: insert:
703: /*
704: * Stick new segment in its place;
705: * check for complete reassembly.
706: */
1.25 cgd 707: if (p == NULL) {
708: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
709: } else {
710: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
711: }
1.1 cgd 712: next = 0;
1.25 cgd 713: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
714: p = q, q = q->ipqe_q.le_next) {
715: if (q->ipqe_ip->ip_off != next)
1.1 cgd 716: return (0);
1.25 cgd 717: next += q->ipqe_ip->ip_len;
1.1 cgd 718: }
1.25 cgd 719: if (p->ipqe_mff)
1.1 cgd 720: return (0);
721:
722: /*
1.41 thorpej 723: * Reassembly is complete. Check for a bogus message size and
724: * concatenate fragments.
1.1 cgd 725: */
1.25 cgd 726: q = fp->ipq_fragq.lh_first;
727: ip = q->ipqe_ip;
1.41 thorpej 728: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
729: ipstat.ips_toolong++;
730: ip_freef(fp);
731: return (0);
732: }
1.50 thorpej 733: m = q->ipqe_m;
1.1 cgd 734: t = m->m_next;
735: m->m_next = 0;
736: m_cat(m, t);
1.25 cgd 737: nq = q->ipqe_q.le_next;
1.72 thorpej 738: pool_put(&ipqent_pool, q);
1.25 cgd 739: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 740: t = q->ipqe_m;
1.25 cgd 741: nq = q->ipqe_q.le_next;
1.72 thorpej 742: pool_put(&ipqent_pool, q);
1.1 cgd 743: m_cat(m, t);
744: }
745:
746: /*
747: * Create header for new ip packet by
748: * modifying header of first packet;
749: * dequeue and discard fragment reassembly header.
750: * Make header visible.
751: */
752: ip->ip_len = next;
1.25 cgd 753: ip->ip_src = fp->ipq_src;
754: ip->ip_dst = fp->ipq_dst;
755: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 756: FREE(fp, M_FTABLE);
1.1 cgd 757: m->m_len += (ip->ip_hl << 2);
758: m->m_data -= (ip->ip_hl << 2);
759: /* some debugging cruft by sklower, below, will go away soon */
760: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
761: register int plen = 0;
1.50 thorpej 762: for (t = m; t; t = t->m_next)
763: plen += t->m_len;
764: m->m_pkthdr.len = plen;
1.1 cgd 765: }
1.50 thorpej 766: return (m);
1.1 cgd 767:
768: dropfrag:
769: ipstat.ips_fragdropped++;
770: m_freem(m);
1.72 thorpej 771: pool_put(&ipqent_pool, ipqe);
1.1 cgd 772: return (0);
773: }
774:
775: /*
776: * Free a fragment reassembly header and all
777: * associated datagrams.
778: */
1.8 mycroft 779: void
1.1 cgd 780: ip_freef(fp)
781: struct ipq *fp;
782: {
1.25 cgd 783: register struct ipqent *q, *p;
1.1 cgd 784:
1.75 thorpej 785: IPQ_LOCK_CHECK();
786:
1.25 cgd 787: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
788: p = q->ipqe_q.le_next;
1.50 thorpej 789: m_freem(q->ipqe_m);
1.25 cgd 790: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 791: pool_put(&ipqent_pool, q);
1.1 cgd 792: }
1.25 cgd 793: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 794: FREE(fp, M_FTABLE);
1.1 cgd 795: }
796:
797: /*
798: * IP timer processing;
799: * if a timer expires on a reassembly
800: * queue, discard it.
801: */
1.8 mycroft 802: void
1.1 cgd 803: ip_slowtimo()
804: {
1.25 cgd 805: register struct ipq *fp, *nfp;
1.24 mycroft 806: int s = splsoftnet();
1.1 cgd 807:
1.75 thorpej 808: IPQ_LOCK();
1.25 cgd 809: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
810: nfp = fp->ipq_q.le_next;
811: if (--fp->ipq_ttl == 0) {
1.1 cgd 812: ipstat.ips_fragtimeout++;
1.25 cgd 813: ip_freef(fp);
1.1 cgd 814: }
815: }
1.75 thorpej 816: IPQ_UNLOCK();
1.63 matt 817: #ifdef GATEWAY
818: ipflow_slowtimo();
819: #endif
1.1 cgd 820: splx(s);
821: }
822:
823: /*
824: * Drain off all datagram fragments.
825: */
1.8 mycroft 826: void
1.1 cgd 827: ip_drain()
828: {
829:
1.75 thorpej 830: /*
831: * We may be called from a device's interrupt context. If
832: * the ipq is already busy, just bail out now.
833: */
834: if (ipq_lock_try() == 0)
835: return;
836:
1.25 cgd 837: while (ipq.lh_first != NULL) {
1.1 cgd 838: ipstat.ips_fragdropped++;
1.25 cgd 839: ip_freef(ipq.lh_first);
1.1 cgd 840: }
1.75 thorpej 841:
842: IPQ_UNLOCK();
1.1 cgd 843: }
844:
845: /*
846: * Do option processing on a datagram,
847: * possibly discarding it if bad options are encountered,
848: * or forwarding it if source-routed.
849: * Returns 1 if packet has been forwarded/freed,
850: * 0 if the packet should be processed further.
851: */
1.8 mycroft 852: int
1.1 cgd 853: ip_dooptions(m)
854: struct mbuf *m;
855: {
856: register struct ip *ip = mtod(m, struct ip *);
857: register u_char *cp;
858: register struct ip_timestamp *ipt;
859: register struct in_ifaddr *ia;
860: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13 mycroft 861: struct in_addr *sin, dst;
1.1 cgd 862: n_time ntime;
863:
1.13 mycroft 864: dst = ip->ip_dst;
1.1 cgd 865: cp = (u_char *)(ip + 1);
866: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
867: for (; cnt > 0; cnt -= optlen, cp += optlen) {
868: opt = cp[IPOPT_OPTVAL];
869: if (opt == IPOPT_EOL)
870: break;
871: if (opt == IPOPT_NOP)
872: optlen = 1;
873: else {
874: optlen = cp[IPOPT_OLEN];
875: if (optlen <= 0 || optlen > cnt) {
876: code = &cp[IPOPT_OLEN] - (u_char *)ip;
877: goto bad;
878: }
879: }
880: switch (opt) {
881:
882: default:
883: break;
884:
885: /*
886: * Source routing with record.
887: * Find interface with current destination address.
888: * If none on this machine then drop if strictly routed,
889: * or do nothing if loosely routed.
890: * Record interface address and bring up next address
891: * component. If strictly routed make sure next
892: * address is on directly accessible net.
893: */
894: case IPOPT_LSRR:
895: case IPOPT_SSRR:
1.47 cjs 896: if (ip_allowsrcrt == 0) {
897: type = ICMP_UNREACH;
898: code = ICMP_UNREACH_NET_PROHIB;
899: goto bad;
900: }
1.1 cgd 901: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
902: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
903: goto bad;
904: }
905: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 906: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 907: if (ia == 0) {
908: if (opt == IPOPT_SSRR) {
909: type = ICMP_UNREACH;
910: code = ICMP_UNREACH_SRCFAIL;
911: goto bad;
912: }
913: /*
914: * Loose routing, and not at next destination
915: * yet; nothing to do except forward.
916: */
917: break;
918: }
919: off--; /* 0 origin */
920: if (off > optlen - sizeof(struct in_addr)) {
921: /*
922: * End of source route. Should be for us.
923: */
924: save_rte(cp, ip->ip_src);
925: break;
926: }
927: /*
928: * locate outgoing interface
929: */
930: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
931: sizeof(ipaddr.sin_addr));
932: if (opt == IPOPT_SSRR) {
933: #define INA struct in_ifaddr *
934: #define SA struct sockaddr *
1.29 mrg 935: ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1 cgd 936: } else
937: ia = ip_rtaddr(ipaddr.sin_addr);
938: if (ia == 0) {
939: type = ICMP_UNREACH;
940: code = ICMP_UNREACH_SRCFAIL;
941: goto bad;
942: }
943: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 944: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 945: (caddr_t)(cp + off), sizeof(struct in_addr));
946: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 947: /*
948: * Let ip_intr's mcast routing check handle mcast pkts
949: */
1.18 mycroft 950: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 951: break;
952:
953: case IPOPT_RR:
954: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
955: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
956: goto bad;
957: }
958: /*
959: * If no space remains, ignore.
960: */
961: off--; /* 0 origin */
962: if (off > optlen - sizeof(struct in_addr))
963: break;
964: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
965: sizeof(ipaddr.sin_addr));
966: /*
967: * locate outgoing interface; if we're the destination,
968: * use the incoming interface (should be same).
969: */
970: if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
971: (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
972: type = ICMP_UNREACH;
973: code = ICMP_UNREACH_HOST;
974: goto bad;
975: }
1.20 mycroft 976: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 977: (caddr_t)(cp + off), sizeof(struct in_addr));
978: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
979: break;
980:
981: case IPOPT_TS:
982: code = cp - (u_char *)ip;
983: ipt = (struct ip_timestamp *)cp;
984: if (ipt->ipt_len < 5)
985: goto bad;
1.15 cgd 986: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 987: if (++ipt->ipt_oflw == 0)
988: goto bad;
989: break;
990: }
991: sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
992: switch (ipt->ipt_flg) {
993:
994: case IPOPT_TS_TSONLY:
995: break;
996:
997: case IPOPT_TS_TSANDADDR:
1.66 thorpej 998: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 999: sizeof(struct in_addr) > ipt->ipt_len)
1000: goto bad;
1.13 mycroft 1001: ipaddr.sin_addr = dst;
1002: ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1003: m->m_pkthdr.rcvif);
1004: if (ia == 0)
1005: continue;
1.20 mycroft 1006: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1007: (caddr_t)sin, sizeof(struct in_addr));
1008: ipt->ipt_ptr += sizeof(struct in_addr);
1009: break;
1010:
1011: case IPOPT_TS_PRESPEC:
1.66 thorpej 1012: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1013: sizeof(struct in_addr) > ipt->ipt_len)
1014: goto bad;
1015: bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
1016: sizeof(struct in_addr));
1017: if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1018: continue;
1019: ipt->ipt_ptr += sizeof(struct in_addr);
1020: break;
1021:
1022: default:
1023: goto bad;
1024: }
1025: ntime = iptime();
1026: bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
1027: sizeof(n_time));
1028: ipt->ipt_ptr += sizeof(n_time);
1029: }
1030: }
1031: if (forward) {
1.26 thorpej 1032: if (ip_forwsrcrt == 0) {
1033: type = ICMP_UNREACH;
1034: code = ICMP_UNREACH_SRCFAIL;
1035: goto bad;
1036: }
1.1 cgd 1037: ip_forward(m, 1);
1038: return (1);
1.13 mycroft 1039: }
1040: return (0);
1.1 cgd 1041: bad:
1.13 mycroft 1042: icmp_error(m, type, code, 0, 0);
1043: ipstat.ips_badoptions++;
1.1 cgd 1044: return (1);
1045: }
1046:
1047: /*
1048: * Given address of next destination (final or next hop),
1049: * return internet address info of interface to be used to get there.
1050: */
1051: struct in_ifaddr *
1052: ip_rtaddr(dst)
1053: struct in_addr dst;
1054: {
1055: register struct sockaddr_in *sin;
1056:
1.19 mycroft 1057: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1058:
1.35 mycroft 1059: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1060: if (ipforward_rt.ro_rt) {
1061: RTFREE(ipforward_rt.ro_rt);
1062: ipforward_rt.ro_rt = 0;
1063: }
1064: sin->sin_family = AF_INET;
1065: sin->sin_len = sizeof(*sin);
1066: sin->sin_addr = dst;
1067:
1068: rtalloc(&ipforward_rt);
1069: }
1070: if (ipforward_rt.ro_rt == 0)
1071: return ((struct in_ifaddr *)0);
1.19 mycroft 1072: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1073: }
1074:
1075: /*
1076: * Save incoming source route for use in replies,
1077: * to be picked up later by ip_srcroute if the receiver is interested.
1078: */
1.13 mycroft 1079: void
1.1 cgd 1080: save_rte(option, dst)
1081: u_char *option;
1082: struct in_addr dst;
1083: {
1084: unsigned olen;
1085:
1086: olen = option[IPOPT_OLEN];
1087: #ifdef DIAGNOSTIC
1088: if (ipprintfs)
1.39 christos 1089: printf("save_rte: olen %d\n", olen);
1.1 cgd 1090: #endif
1091: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1092: return;
1093: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1094: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1095: ip_srcrt.dst = dst;
1096: }
1097:
1098: /*
1099: * Retrieve incoming source route for use in replies,
1100: * in the same form used by setsockopt.
1101: * The first hop is placed before the options, will be removed later.
1102: */
1103: struct mbuf *
1104: ip_srcroute()
1105: {
1106: register struct in_addr *p, *q;
1107: register struct mbuf *m;
1108:
1109: if (ip_nhops == 0)
1110: return ((struct mbuf *)0);
1111: m = m_get(M_DONTWAIT, MT_SOOPTS);
1112: if (m == 0)
1113: return ((struct mbuf *)0);
1114:
1.13 mycroft 1115: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1116:
1117: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1118: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1119: OPTSIZ;
1120: #ifdef DIAGNOSTIC
1121: if (ipprintfs)
1.39 christos 1122: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1123: #endif
1124:
1125: /*
1126: * First save first hop for return route
1127: */
1128: p = &ip_srcrt.route[ip_nhops - 1];
1129: *(mtod(m, struct in_addr *)) = *p--;
1130: #ifdef DIAGNOSTIC
1131: if (ipprintfs)
1.39 christos 1132: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1133: #endif
1134:
1135: /*
1136: * Copy option fields and padding (nop) to mbuf.
1137: */
1138: ip_srcrt.nop = IPOPT_NOP;
1139: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1140: bcopy((caddr_t)&ip_srcrt.nop,
1141: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1142: q = (struct in_addr *)(mtod(m, caddr_t) +
1143: sizeof(struct in_addr) + OPTSIZ);
1144: #undef OPTSIZ
1145: /*
1146: * Record return path as an IP source route,
1147: * reversing the path (pointers are now aligned).
1148: */
1149: while (p >= ip_srcrt.route) {
1150: #ifdef DIAGNOSTIC
1151: if (ipprintfs)
1.39 christos 1152: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1153: #endif
1154: *q++ = *p--;
1155: }
1156: /*
1157: * Last hop goes to final destination.
1158: */
1159: *q = ip_srcrt.dst;
1160: #ifdef DIAGNOSTIC
1161: if (ipprintfs)
1.39 christos 1162: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1163: #endif
1164: return (m);
1165: }
1166:
1167: /*
1168: * Strip out IP options, at higher
1169: * level protocol in the kernel.
1170: * Second argument is buffer to which options
1171: * will be moved, and return value is their length.
1172: * XXX should be deleted; last arg currently ignored.
1173: */
1.8 mycroft 1174: void
1.1 cgd 1175: ip_stripoptions(m, mopt)
1176: register struct mbuf *m;
1177: struct mbuf *mopt;
1178: {
1179: register int i;
1180: struct ip *ip = mtod(m, struct ip *);
1181: register caddr_t opts;
1182: int olen;
1183:
1.79 mycroft 1184: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1185: opts = (caddr_t)(ip + 1);
1186: i = m->m_len - (sizeof (struct ip) + olen);
1187: bcopy(opts + olen, opts, (unsigned)i);
1188: m->m_len -= olen;
1189: if (m->m_flags & M_PKTHDR)
1190: m->m_pkthdr.len -= olen;
1.79 mycroft 1191: ip->ip_len -= olen;
1192: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1193: }
1194:
1.23 mycroft 1195: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1196: 0, 0, 0, 0,
1197: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1198: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1199: EMSGSIZE, EHOSTUNREACH, 0, 0,
1200: 0, 0, 0, 0,
1201: ENOPROTOOPT
1202: };
1203:
1204: /*
1205: * Forward a packet. If some error occurs return the sender
1206: * an icmp packet. Note we can't always generate a meaningful
1207: * icmp message because icmp doesn't have a large enough repertoire
1208: * of codes and types.
1209: *
1210: * If not forwarding, just drop the packet. This could be confusing
1211: * if ipforwarding was zero but some routing protocol was advancing
1212: * us as a gateway to somewhere. However, we must let the routing
1213: * protocol deal with that.
1214: *
1215: * The srcrt parameter indicates whether the packet is being forwarded
1216: * via a source route.
1217: */
1.13 mycroft 1218: void
1.1 cgd 1219: ip_forward(m, srcrt)
1220: struct mbuf *m;
1221: int srcrt;
1222: {
1223: register struct ip *ip = mtod(m, struct ip *);
1224: register struct sockaddr_in *sin;
1225: register struct rtentry *rt;
1.28 christos 1226: int error, type = 0, code = 0;
1.1 cgd 1227: struct mbuf *mcopy;
1.13 mycroft 1228: n_long dest;
1229: struct ifnet *destifp;
1.1 cgd 1230:
1.13 mycroft 1231: dest = 0;
1.1 cgd 1232: #ifdef DIAGNOSTIC
1233: if (ipprintfs)
1.70 thorpej 1234: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1235: ntohl(ip->ip_src.s_addr),
1236: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1237: #endif
1238: if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
1239: ipstat.ips_cantforward++;
1240: m_freem(m);
1241: return;
1242: }
1243: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1244: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1245: return;
1246: }
1247: ip->ip_ttl -= IPTTLDEC;
1248:
1.19 mycroft 1249: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1250: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1251: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1252: if (ipforward_rt.ro_rt) {
1253: RTFREE(ipforward_rt.ro_rt);
1254: ipforward_rt.ro_rt = 0;
1255: }
1256: sin->sin_family = AF_INET;
1.35 mycroft 1257: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1258: sin->sin_addr = ip->ip_dst;
1259:
1260: rtalloc(&ipforward_rt);
1261: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1262: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1263: return;
1264: }
1265: rt = ipforward_rt.ro_rt;
1266: }
1267:
1268: /*
1.34 mycroft 1269: * Save at most 68 bytes of the packet in case
1.1 cgd 1270: * we need to generate an ICMP message to the src.
1271: */
1.34 mycroft 1272: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1273:
1274: /*
1275: * If forwarding packet using same interface that it came in on,
1276: * perhaps should send a redirect to sender to shortcut a hop.
1277: * Only send redirect if source is sending directly to us,
1278: * and if packet was not source routed (or has any options).
1279: * Also, don't send redirect if forwarding using a default route
1280: * or a route modified by a redirect.
1281: */
1282: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1283: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1284: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1285: ipsendredirects && !srcrt) {
1.19 mycroft 1286: if (rt->rt_ifa &&
1287: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1288: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1289: if (rt->rt_flags & RTF_GATEWAY)
1290: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1291: else
1292: dest = ip->ip_dst.s_addr;
1293: /*
1294: * Router requirements says to only send host
1295: * redirects.
1296: */
1297: type = ICMP_REDIRECT;
1298: code = ICMP_REDIRECT_HOST;
1.1 cgd 1299: #ifdef DIAGNOSTIC
1.77 thorpej 1300: if (ipprintfs)
1301: printf("redirect (%d) to %x\n", code,
1302: (u_int32_t)dest);
1.1 cgd 1303: #endif
1304: }
1305: }
1306:
1.27 thorpej 1307: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1308: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1309: if (error)
1310: ipstat.ips_cantforward++;
1311: else {
1312: ipstat.ips_forward++;
1313: if (type)
1314: ipstat.ips_redirectsent++;
1315: else {
1.63 matt 1316: if (mcopy) {
1317: #ifdef GATEWAY
1.64 thorpej 1318: if (mcopy->m_flags & M_CANFASTFWD)
1319: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1320: #endif
1.1 cgd 1321: m_freem(mcopy);
1.63 matt 1322: }
1.1 cgd 1323: return;
1324: }
1325: }
1326: if (mcopy == NULL)
1327: return;
1.13 mycroft 1328: destifp = NULL;
1329:
1.1 cgd 1330: switch (error) {
1331:
1332: case 0: /* forwarded, but need redirect */
1333: /* type, code set above */
1334: break;
1335:
1336: case ENETUNREACH: /* shouldn't happen, checked above */
1337: case EHOSTUNREACH:
1338: case ENETDOWN:
1339: case EHOSTDOWN:
1340: default:
1341: type = ICMP_UNREACH;
1342: code = ICMP_UNREACH_HOST;
1343: break;
1344:
1345: case EMSGSIZE:
1346: type = ICMP_UNREACH;
1347: code = ICMP_UNREACH_NEEDFRAG;
1.13 mycroft 1348: if (ipforward_rt.ro_rt)
1349: destifp = ipforward_rt.ro_rt->rt_ifp;
1.1 cgd 1350: ipstat.ips_cantfrag++;
1351: break;
1352:
1353: case ENOBUFS:
1354: type = ICMP_SOURCEQUENCH;
1355: code = 0;
1356: break;
1357: }
1.13 mycroft 1358: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1359: }
1360:
1361: void
1362: ip_savecontrol(inp, mp, ip, m)
1363: register struct inpcb *inp;
1364: register struct mbuf **mp;
1365: register struct ip *ip;
1366: register struct mbuf *m;
1367: {
1368:
1369: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1370: struct timeval tv;
1371:
1372: microtime(&tv);
1373: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1374: SCM_TIMESTAMP, SOL_SOCKET);
1375: if (*mp)
1376: mp = &(*mp)->m_next;
1377: }
1378: if (inp->inp_flags & INP_RECVDSTADDR) {
1379: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1380: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1381: if (*mp)
1382: mp = &(*mp)->m_next;
1383: }
1384: #ifdef notyet
1385: /*
1386: * XXX
1387: * Moving these out of udp_input() made them even more broken
1388: * than they already were.
1389: * - fenner@parc.xerox.com
1390: */
1391: /* options were tossed already */
1392: if (inp->inp_flags & INP_RECVOPTS) {
1393: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1394: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1395: if (*mp)
1396: mp = &(*mp)->m_next;
1397: }
1398: /* ip_srcroute doesn't do what we want here, need to fix */
1399: if (inp->inp_flags & INP_RECVRETOPTS) {
1400: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1401: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1402: if (*mp)
1403: mp = &(*mp)->m_next;
1404: }
1405: #endif
1406: if (inp->inp_flags & INP_RECVIF) {
1407: struct sockaddr_dl sdl;
1408:
1409: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1410: sdl.sdl_family = AF_LINK;
1411: sdl.sdl_index = m->m_pkthdr.rcvif ?
1412: m->m_pkthdr.rcvif->if_index : 0;
1413: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1414: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1415: IP_RECVIF, IPPROTO_IP);
1416: if (*mp)
1417: mp = &(*mp)->m_next;
1418: }
1.13 mycroft 1419: }
1420:
1421: int
1422: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1423: int *name;
1424: u_int namelen;
1425: void *oldp;
1426: size_t *oldlenp;
1427: void *newp;
1428: size_t newlen;
1429: {
1.52 thorpej 1430: extern int subnetsarelocal;
1431:
1.54 lukem 1432: int error, old;
1433:
1.13 mycroft 1434: /* All sysctl names at this level are terminal. */
1435: if (namelen != 1)
1436: return (ENOTDIR);
1437:
1438: switch (name[0]) {
1439: case IPCTL_FORWARDING:
1440: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1441: case IPCTL_SENDREDIRECTS:
1442: return (sysctl_int(oldp, oldlenp, newp, newlen,
1443: &ipsendredirects));
1444: case IPCTL_DEFTTL:
1445: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1446: #ifdef notyet
1447: case IPCTL_DEFMTU:
1448: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1449: #endif
1.26 thorpej 1450: case IPCTL_FORWSRCRT:
1.47 cjs 1451: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1452: if (securelevel > 0)
1.46 cjs 1453: return (sysctl_rdint(oldp, oldlenp, newp,
1454: ip_forwsrcrt));
1455: else
1456: return (sysctl_int(oldp, oldlenp, newp, newlen,
1457: &ip_forwsrcrt));
1.27 thorpej 1458: case IPCTL_DIRECTEDBCAST:
1459: return (sysctl_int(oldp, oldlenp, newp, newlen,
1460: &ip_directedbcast));
1.47 cjs 1461: case IPCTL_ALLOWSRCRT:
1462: return (sysctl_int(oldp, oldlenp, newp, newlen,
1463: &ip_allowsrcrt));
1.52 thorpej 1464: case IPCTL_SUBNETSARELOCAL:
1465: return (sysctl_int(oldp, oldlenp, newp, newlen,
1466: &subnetsarelocal));
1.53 kml 1467: case IPCTL_MTUDISC:
1.60 kml 1468: error = sysctl_int(oldp, oldlenp, newp, newlen,
1469: &ip_mtudisc);
1470: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1471: ip_mtudisc_timeout_q =
1472: rt_timer_queue_create(ip_mtudisc_timeout);
1473: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1474: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1475: ip_mtudisc_timeout_q = NULL;
1476: }
1477: return error;
1.54 lukem 1478: case IPCTL_ANONPORTMIN:
1479: old = anonportmin;
1480: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1481: if (anonportmin >= anonportmax || anonportmin > 65535
1482: #ifndef IPNOPRIVPORTS
1483: || anonportmin < IPPORT_RESERVED
1484: #endif
1485: ) {
1486: anonportmin = old;
1487: return (EINVAL);
1488: }
1489: return (error);
1490: case IPCTL_ANONPORTMAX:
1491: old = anonportmax;
1492: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1493: if (anonportmin >= anonportmax || anonportmax > 65535
1494: #ifndef IPNOPRIVPORTS
1495: || anonportmax < IPPORT_RESERVED
1496: #endif
1497: ) {
1498: anonportmax = old;
1499: return (EINVAL);
1500: }
1.60 kml 1501: return (error);
1502: case IPCTL_MTUDISCTIMEOUT:
1503: error = sysctl_int(oldp, oldlenp, newp, newlen,
1504: &ip_mtudisc_timeout);
1505: if (ip_mtudisc_timeout_q != NULL)
1506: rt_timer_queue_change(ip_mtudisc_timeout_q,
1507: ip_mtudisc_timeout);
1.54 lukem 1508: return (error);
1.65 matt 1509: #ifdef GATEWAY
1510: case IPCTL_MAXFLOWS:
1.67 thorpej 1511: {
1512: int s;
1513:
1.65 matt 1514: error = sysctl_int(oldp, oldlenp, newp, newlen,
1515: &ip_maxflows);
1.67 thorpej 1516: s = splsoftnet();
1.65 matt 1517: ipflow_reap(0);
1.67 thorpej 1518: splx(s);
1.65 matt 1519: return (error);
1.67 thorpej 1520: }
1.65 matt 1521: #endif
1.13 mycroft 1522: default:
1523: return (EOPNOTSUPP);
1524: }
1525: /* NOTREACHED */
1.1 cgd 1526: }
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