Annotation of src/sys/netinet/ip_input.c, Revision 1.82.2.7
1.82.2.7! he 1: /* $NetBSD: ip_input.c,v 1.82.2.6 2000/05/06 16:43:25 he 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;
1.82.2.7! he 170: int ip_nfragpackets = 0;
! 171: int ip_maxfragpackets = 200;
1.75 thorpej 172:
173: static __inline int ipq_lock_try __P((void));
174: static __inline void ipq_unlock __P((void));
175:
176: static __inline int
177: ipq_lock_try()
178: {
179: int s;
180:
181: s = splimp();
182: if (ipq_locked) {
183: splx(s);
184: return (0);
185: }
186: ipq_locked = 1;
187: splx(s);
188: return (1);
189: }
190:
191: static __inline void
192: ipq_unlock()
193: {
194: int s;
195:
196: s = splimp();
197: ipq_locked = 0;
198: splx(s);
199: }
200:
201: #ifdef DIAGNOSTIC
202: #define IPQ_LOCK() \
203: do { \
204: if (ipq_lock_try() == 0) { \
205: printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
206: panic("ipq_lock"); \
207: } \
208: } while (0)
209: #define IPQ_LOCK_CHECK() \
210: do { \
211: if (ipq_locked == 0) { \
212: printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
213: panic("ipq lock check"); \
214: } \
215: } while (0)
216: #else
217: #define IPQ_LOCK() (void) ipq_lock_try()
218: #define IPQ_LOCK_CHECK() /* nothing */
219: #endif
220:
221: #define IPQ_UNLOCK() ipq_unlock()
1.1 cgd 222:
1.72 thorpej 223: struct pool ipqent_pool;
224:
1.1 cgd 225: /*
226: * We need to save the IP options in case a protocol wants to respond
227: * to an incoming packet over the same route if the packet got here
228: * using IP source routing. This allows connection establishment and
229: * maintenance when the remote end is on a network that is not known
230: * to us.
231: */
232: int ip_nhops = 0;
233: static struct ip_srcrt {
234: struct in_addr dst; /* final destination */
235: char nop; /* one NOP to align */
236: char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
237: struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
238: } ip_srcrt;
239:
1.13 mycroft 240: static void save_rte __P((u_char *, struct in_addr));
1.35 mycroft 241:
1.1 cgd 242: /*
243: * IP initialization: fill in IP protocol switch table.
244: * All protocols not implemented in kernel go to raw IP protocol handler.
245: */
1.8 mycroft 246: void
1.1 cgd 247: ip_init()
248: {
249: register struct protosw *pr;
250: register int i;
251:
1.72 thorpej 252: pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
253: 0, NULL, NULL, M_IPQ);
254:
1.1 cgd 255: pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
256: if (pr == 0)
257: panic("ip_init");
258: for (i = 0; i < IPPROTO_MAX; i++)
259: ip_protox[i] = pr - inetsw;
260: for (pr = inetdomain.dom_protosw;
261: pr < inetdomain.dom_protoswNPROTOSW; pr++)
262: if (pr->pr_domain->dom_family == PF_INET &&
263: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
264: ip_protox[pr->pr_protocol] = pr - inetsw;
1.25 cgd 265: LIST_INIT(&ipq);
1.1 cgd 266: ip_id = time.tv_sec & 0xffff;
267: ipintrq.ifq_maxlen = ipqmaxlen;
1.22 mycroft 268: TAILQ_INIT(&in_ifaddr);
1.57 tls 269: in_ifaddrhashtbl =
270: hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash);
1.60 kml 271: if (ip_mtudisc != 0)
272: ip_mtudisc_timeout_q =
273: rt_timer_queue_create(ip_mtudisc_timeout);
1.73 thorpej 274: #ifdef GATEWAY
275: ipflow_init();
276: #endif
1.1 cgd 277: }
278:
279: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
280: struct route ipforward_rt;
281:
282: /*
283: * Ip input routine. Checksum and byte swap header. If fragmented
284: * try to reassemble. Process options. Pass to next level.
285: */
1.8 mycroft 286: void
1.1 cgd 287: ipintr()
288: {
1.33 mrg 289: register struct ip *ip = NULL;
1.1 cgd 290: register struct mbuf *m;
291: register struct ipq *fp;
292: register struct in_ifaddr *ia;
1.57 tls 293: register struct ifaddr *ifa;
1.25 cgd 294: struct ipqent *ipqe;
1.35 mycroft 295: int hlen = 0, mff, len, s;
1.36 mrg 296: #ifdef PFIL_HOOKS
1.33 mrg 297: struct packet_filter_hook *pfh;
298: struct mbuf *m0;
1.43 mrg 299: int rv;
1.36 mrg 300: #endif /* PFIL_HOOKS */
1.1 cgd 301:
302: next:
303: /*
304: * Get next datagram off input queue and get IP header
305: * in first mbuf.
306: */
307: s = splimp();
308: IF_DEQUEUE(&ipintrq, m);
309: splx(s);
1.13 mycroft 310: if (m == 0)
1.1 cgd 311: return;
312: #ifdef DIAGNOSTIC
313: if ((m->m_flags & M_PKTHDR) == 0)
314: panic("ipintr no HDR");
315: #endif
316: /*
317: * If no IP addresses have been set yet but the interfaces
318: * are receiving, can't do anything with incoming packets yet.
319: */
1.22 mycroft 320: if (in_ifaddr.tqh_first == 0)
1.1 cgd 321: goto bad;
322: ipstat.ips_total++;
323: if (m->m_len < sizeof (struct ip) &&
324: (m = m_pullup(m, sizeof (struct ip))) == 0) {
325: ipstat.ips_toosmall++;
326: goto next;
327: }
328: ip = mtod(m, struct ip *);
1.13 mycroft 329: if (ip->ip_v != IPVERSION) {
330: ipstat.ips_badvers++;
331: goto bad;
332: }
1.1 cgd 333: hlen = ip->ip_hl << 2;
334: if (hlen < sizeof(struct ip)) { /* minimum header length */
335: ipstat.ips_badhlen++;
336: goto bad;
337: }
338: if (hlen > m->m_len) {
339: if ((m = m_pullup(m, hlen)) == 0) {
340: ipstat.ips_badhlen++;
341: goto next;
342: }
343: ip = mtod(m, struct ip *);
344: }
1.82.2.4 he 345:
346: /*
347: * RFC1122: packets with a multicast source address are
348: * not allowed.
349: */
350: if (IN_MULTICAST(ip->ip_src.s_addr)) {
351: /* XXX stat */
352: goto bad;
353: }
354:
1.78 mycroft 355: if (in_cksum(m, hlen) != 0) {
1.1 cgd 356: ipstat.ips_badsum++;
357: goto bad;
358: }
359:
360: /*
361: * Convert fields to host representation.
362: */
363: NTOHS(ip->ip_len);
364: NTOHS(ip->ip_off);
1.35 mycroft 365: len = ip->ip_len;
1.81 proff 366:
367: /*
368: * Check for additional length bogosity
369: */
370: if (len < hlen)
371: {
372: ipstat.ips_badlen++;
373: goto bad;
374: }
1.1 cgd 375:
376: /*
377: * Check that the amount of data in the buffers
378: * is as at least much as the IP header would have us expect.
379: * Trim mbufs if longer than we expect.
380: * Drop packet if shorter than we expect.
381: */
1.35 mycroft 382: if (m->m_pkthdr.len < len) {
1.1 cgd 383: ipstat.ips_tooshort++;
384: goto bad;
385: }
1.35 mycroft 386: if (m->m_pkthdr.len > len) {
1.1 cgd 387: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 388: m->m_len = len;
389: m->m_pkthdr.len = len;
1.1 cgd 390: } else
1.35 mycroft 391: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 392: }
393:
1.64 thorpej 394: /*
395: * Assume that we can create a fast-forward IP flow entry
396: * based on this packet.
397: */
398: m->m_flags |= M_CANFASTFWD;
399:
1.36 mrg 400: #ifdef PFIL_HOOKS
1.33 mrg 401: /*
1.64 thorpej 402: * Run through list of hooks for input packets. If there are any
403: * filters which require that additional packets in the flow are
404: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
405: * Note that filters must _never_ set this flag, as another filter
406: * in the list may have previously cleared it.
1.33 mrg 407: */
408: m0 = m;
1.59 mrg 409: for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33 mrg 410: if (pfh->pfil_func) {
1.43 mrg 411: rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
412: if (rv)
1.40 veego 413: goto next;
1.68 sommerfe 414: m = m0;
415: if (m == NULL)
416: goto next;
417: ip = mtod(m, struct ip *);
1.33 mrg 418: }
1.36 mrg 419: #endif /* PFIL_HOOKS */
1.33 mrg 420:
1.1 cgd 421: /*
422: * Process options and, if not destined for us,
423: * ship it on. ip_dooptions returns 1 when an
424: * error was detected (causing an icmp message
425: * to be sent and the original packet to be freed).
426: */
427: ip_nhops = 0; /* for source routed packets */
428: if (hlen > sizeof (struct ip) && ip_dooptions(m))
429: goto next;
430:
431: /*
432: * Check our list of addresses, to see if the packet is for us.
433: */
1.57 tls 434: INADDR_TO_IA(ip->ip_dst, ia);
1.82.2.2 perry 435: if (ia != NULL)
436: goto ours;
1.57 tls 437: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
438: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
439: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
440: if (ifa->ifa_addr->sa_family != AF_INET) continue;
441: ia = ifatoia(ifa);
1.35 mycroft 442: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
443: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 444: /*
445: * Look for all-0's host part (old broadcast addr),
446: * either for subnet or net.
447: */
448: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 449: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 450: goto ours;
1.57 tls 451: /*
452: * An interface with IP address zero accepts
453: * all packets that arrive on that interface.
454: */
455: if (in_nullhost(ia->ia_addr.sin_addr))
456: goto ours;
1.1 cgd 457: }
458: }
1.18 mycroft 459: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 460: struct in_multi *inm;
461: #ifdef MROUTING
462: extern struct socket *ip_mrouter;
1.10 brezak 463:
464: if (m->m_flags & M_EXT) {
465: if ((m = m_pullup(m, hlen)) == 0) {
466: ipstat.ips_toosmall++;
467: goto next;
468: }
469: ip = mtod(m, struct ip *);
470: }
1.4 hpeyerl 471:
472: if (ip_mrouter) {
473: /*
474: * If we are acting as a multicast router, all
475: * incoming multicast packets are passed to the
476: * kernel-level multicast forwarding function.
477: * The packet is returned (relatively) intact; if
478: * ip_mforward() returns a non-zero value, the packet
479: * must be discarded, else it may be accepted below.
480: *
481: * (The IP ident field is put in the same byte order
482: * as expected when ip_mforward() is called from
483: * ip_output().)
484: */
1.13 mycroft 485: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
486: ipstat.ips_cantforward++;
1.4 hpeyerl 487: m_freem(m);
488: goto next;
489: }
490:
491: /*
492: * The process-level routing demon needs to receive
493: * all multicast IGMP packets, whether or not this
494: * host belongs to their destination groups.
495: */
496: if (ip->ip_p == IPPROTO_IGMP)
497: goto ours;
1.13 mycroft 498: ipstat.ips_forward++;
1.4 hpeyerl 499: }
500: #endif
501: /*
502: * See if we belong to the destination multicast group on the
503: * arrival interface.
504: */
505: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
506: if (inm == NULL) {
1.13 mycroft 507: ipstat.ips_cantforward++;
1.4 hpeyerl 508: m_freem(m);
509: goto next;
510: }
511: goto ours;
512: }
1.19 mycroft 513: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 514: in_nullhost(ip->ip_dst))
1.1 cgd 515: goto ours;
516:
517: /*
518: * Not for us; forward if possible and desirable.
519: */
520: if (ipforwarding == 0) {
521: ipstat.ips_cantforward++;
522: m_freem(m);
523: } else
524: ip_forward(m, 0);
525: goto next;
526:
527: ours:
528: /*
529: * If offset or IP_MF are set, must reassemble.
530: * Otherwise, nothing need be done.
531: * (We could look in the reassembly queue to see
532: * if the packet was previously fragmented,
533: * but it's not worth the time; just let them time out.)
534: */
1.37 perry 535: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 536: /*
537: * Look for queue of fragments
538: * of this datagram.
539: */
1.75 thorpej 540: IPQ_LOCK();
1.25 cgd 541: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 542: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 543: in_hosteq(ip->ip_src, fp->ipq_src) &&
544: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 545: ip->ip_p == fp->ipq_p)
546: goto found;
547: fp = 0;
548: found:
549:
550: /*
551: * Adjust ip_len to not reflect header,
1.25 cgd 552: * set ipqe_mff if more fragments are expected,
1.1 cgd 553: * convert offset of this to bytes.
554: */
555: ip->ip_len -= hlen;
1.25 cgd 556: mff = (ip->ip_off & IP_MF) != 0;
557: if (mff) {
1.16 cgd 558: /*
559: * Make sure that fragments have a data length
560: * that's a non-zero multiple of 8 bytes.
561: */
1.17 cgd 562: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 563: ipstat.ips_badfrags++;
1.75 thorpej 564: IPQ_UNLOCK();
1.16 cgd 565: goto bad;
566: }
567: }
1.1 cgd 568: ip->ip_off <<= 3;
569:
570: /*
571: * If datagram marked as having more fragments
572: * or if this is not the first fragment,
573: * attempt reassembly; if it succeeds, proceed.
574: */
1.25 cgd 575: if (mff || ip->ip_off) {
1.1 cgd 576: ipstat.ips_fragments++;
1.72 thorpej 577: ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25 cgd 578: if (ipqe == NULL) {
579: ipstat.ips_rcvmemdrop++;
1.75 thorpej 580: IPQ_UNLOCK();
1.25 cgd 581: goto bad;
582: }
583: ipqe->ipqe_mff = mff;
1.50 thorpej 584: ipqe->ipqe_m = m;
1.25 cgd 585: ipqe->ipqe_ip = ip;
1.50 thorpej 586: m = ip_reass(ipqe, fp);
1.75 thorpej 587: if (m == 0) {
588: IPQ_UNLOCK();
1.1 cgd 589: goto next;
1.75 thorpej 590: }
1.13 mycroft 591: ipstat.ips_reassembled++;
1.50 thorpej 592: ip = mtod(m, struct ip *);
1.74 thorpej 593: hlen = ip->ip_hl << 2;
1.79 mycroft 594: ip->ip_len += hlen;
1.1 cgd 595: } else
596: if (fp)
597: ip_freef(fp);
1.75 thorpej 598: IPQ_UNLOCK();
1.79 mycroft 599: }
1.1 cgd 600:
601: /*
602: * Switch out to protocol's input routine.
603: */
1.82 aidan 604: #if IFA_STATS
605: ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
606: #endif
1.1 cgd 607: ipstat.ips_delivered++;
608: (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
609: goto next;
610: bad:
611: m_freem(m);
612: goto next;
613: }
614:
615: /*
616: * Take incoming datagram fragment and try to
617: * reassemble it into whole datagram. If a chain for
618: * reassembly of this datagram already exists, then it
619: * is given as fp; otherwise have to make a chain.
620: */
1.50 thorpej 621: struct mbuf *
1.25 cgd 622: ip_reass(ipqe, fp)
623: register struct ipqent *ipqe;
1.1 cgd 624: register struct ipq *fp;
625: {
1.50 thorpej 626: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 627: register struct ipqent *nq, *p, *q;
628: struct ip *ip;
1.1 cgd 629: struct mbuf *t;
1.25 cgd 630: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 631: int i, next;
632:
1.75 thorpej 633: IPQ_LOCK_CHECK();
634:
1.1 cgd 635: /*
636: * Presence of header sizes in mbufs
637: * would confuse code below.
638: */
639: m->m_data += hlen;
640: m->m_len -= hlen;
641:
642: /*
643: * If first fragment to arrive, create a reassembly queue.
644: */
645: if (fp == 0) {
1.82.2.7! he 646: /*
! 647: * Enforce upper bound on number of fragmented packets
! 648: * for which we attempt reassembly;
! 649: * If maxfrag is 0, never accept fragments.
! 650: * If maxfrag is -1, accept all fragments without limitation.
! 651: */
! 652: if (ip_maxfragpackets < 0)
! 653: ;
! 654: else if (ip_nfragpackets >= ip_maxfragpackets)
! 655: goto dropfrag;
! 656: ip_nfragpackets++;
1.50 thorpej 657: MALLOC(fp, struct ipq *, sizeof (struct ipq),
658: M_FTABLE, M_NOWAIT);
659: if (fp == NULL)
1.1 cgd 660: goto dropfrag;
1.25 cgd 661: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 662: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 663: fp->ipq_p = ipqe->ipqe_ip->ip_p;
664: fp->ipq_id = ipqe->ipqe_ip->ip_id;
665: LIST_INIT(&fp->ipq_fragq);
666: fp->ipq_src = ipqe->ipqe_ip->ip_src;
667: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
668: p = NULL;
1.1 cgd 669: goto insert;
670: }
671:
672: /*
673: * Find a segment which begins after this one does.
674: */
1.25 cgd 675: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
676: p = q, q = q->ipqe_q.le_next)
677: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 678: break;
679:
680: /*
681: * If there is a preceding segment, it may provide some of
682: * our data already. If so, drop the data from the incoming
683: * segment. If it provides all of our data, drop us.
684: */
1.25 cgd 685: if (p != NULL) {
686: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
687: ipqe->ipqe_ip->ip_off;
1.1 cgd 688: if (i > 0) {
1.25 cgd 689: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 690: goto dropfrag;
1.50 thorpej 691: m_adj(ipqe->ipqe_m, i);
1.25 cgd 692: ipqe->ipqe_ip->ip_off += i;
693: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 694: }
695: }
696:
697: /*
698: * While we overlap succeeding segments trim them or,
699: * if they are completely covered, dequeue them.
700: */
1.25 cgd 701: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
702: q->ipqe_ip->ip_off; q = nq) {
703: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
704: q->ipqe_ip->ip_off;
705: if (i < q->ipqe_ip->ip_len) {
706: q->ipqe_ip->ip_len -= i;
707: q->ipqe_ip->ip_off += i;
1.50 thorpej 708: m_adj(q->ipqe_m, i);
1.1 cgd 709: break;
710: }
1.25 cgd 711: nq = q->ipqe_q.le_next;
1.50 thorpej 712: m_freem(q->ipqe_m);
1.25 cgd 713: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 714: pool_put(&ipqent_pool, q);
1.1 cgd 715: }
716:
717: insert:
718: /*
719: * Stick new segment in its place;
720: * check for complete reassembly.
721: */
1.25 cgd 722: if (p == NULL) {
723: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
724: } else {
725: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
726: }
1.1 cgd 727: next = 0;
1.25 cgd 728: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
729: p = q, q = q->ipqe_q.le_next) {
730: if (q->ipqe_ip->ip_off != next)
1.1 cgd 731: return (0);
1.25 cgd 732: next += q->ipqe_ip->ip_len;
1.1 cgd 733: }
1.25 cgd 734: if (p->ipqe_mff)
1.1 cgd 735: return (0);
736:
737: /*
1.41 thorpej 738: * Reassembly is complete. Check for a bogus message size and
739: * concatenate fragments.
1.1 cgd 740: */
1.25 cgd 741: q = fp->ipq_fragq.lh_first;
742: ip = q->ipqe_ip;
1.41 thorpej 743: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
744: ipstat.ips_toolong++;
745: ip_freef(fp);
746: return (0);
747: }
1.50 thorpej 748: m = q->ipqe_m;
1.1 cgd 749: t = m->m_next;
750: m->m_next = 0;
751: m_cat(m, t);
1.25 cgd 752: nq = q->ipqe_q.le_next;
1.72 thorpej 753: pool_put(&ipqent_pool, q);
1.25 cgd 754: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 755: t = q->ipqe_m;
1.25 cgd 756: nq = q->ipqe_q.le_next;
1.72 thorpej 757: pool_put(&ipqent_pool, q);
1.1 cgd 758: m_cat(m, t);
759: }
760:
761: /*
762: * Create header for new ip packet by
763: * modifying header of first packet;
764: * dequeue and discard fragment reassembly header.
765: * Make header visible.
766: */
767: ip->ip_len = next;
1.25 cgd 768: ip->ip_src = fp->ipq_src;
769: ip->ip_dst = fp->ipq_dst;
770: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 771: FREE(fp, M_FTABLE);
1.82.2.7! he 772: ip_nfragpackets--;
1.1 cgd 773: m->m_len += (ip->ip_hl << 2);
774: m->m_data -= (ip->ip_hl << 2);
775: /* some debugging cruft by sklower, below, will go away soon */
776: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
777: register int plen = 0;
1.50 thorpej 778: for (t = m; t; t = t->m_next)
779: plen += t->m_len;
780: m->m_pkthdr.len = plen;
1.1 cgd 781: }
1.50 thorpej 782: return (m);
1.1 cgd 783:
784: dropfrag:
785: ipstat.ips_fragdropped++;
786: m_freem(m);
1.72 thorpej 787: pool_put(&ipqent_pool, ipqe);
1.1 cgd 788: return (0);
789: }
790:
791: /*
792: * Free a fragment reassembly header and all
793: * associated datagrams.
794: */
1.8 mycroft 795: void
1.1 cgd 796: ip_freef(fp)
797: struct ipq *fp;
798: {
1.25 cgd 799: register struct ipqent *q, *p;
1.1 cgd 800:
1.75 thorpej 801: IPQ_LOCK_CHECK();
802:
1.25 cgd 803: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
804: p = q->ipqe_q.le_next;
1.50 thorpej 805: m_freem(q->ipqe_m);
1.25 cgd 806: LIST_REMOVE(q, ipqe_q);
1.72 thorpej 807: pool_put(&ipqent_pool, q);
1.1 cgd 808: }
1.25 cgd 809: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 810: FREE(fp, M_FTABLE);
1.82.2.7! he 811: ip_nfragpackets--;
1.1 cgd 812: }
813:
814: /*
815: * IP timer processing;
816: * if a timer expires on a reassembly
817: * queue, discard it.
818: */
1.8 mycroft 819: void
1.1 cgd 820: ip_slowtimo()
821: {
1.25 cgd 822: register struct ipq *fp, *nfp;
1.24 mycroft 823: int s = splsoftnet();
1.1 cgd 824:
1.75 thorpej 825: IPQ_LOCK();
1.25 cgd 826: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
827: nfp = fp->ipq_q.le_next;
828: if (--fp->ipq_ttl == 0) {
1.1 cgd 829: ipstat.ips_fragtimeout++;
1.25 cgd 830: ip_freef(fp);
1.1 cgd 831: }
832: }
1.82.2.7! he 833: /*
! 834: * If we are over the maximum number of fragments
! 835: * (due to the limit being lowered), drain off
! 836: * enough to get down to the new limit.
! 837: */
! 838: if (ip_maxfragpackets < 0)
! 839: ;
! 840: else {
! 841: while (ip_nfragpackets > ip_maxfragpackets && ipq.lh_first)
! 842: ip_freef(ipq.lh_first);
! 843: }
1.75 thorpej 844: IPQ_UNLOCK();
1.63 matt 845: #ifdef GATEWAY
846: ipflow_slowtimo();
847: #endif
1.1 cgd 848: splx(s);
849: }
850:
851: /*
852: * Drain off all datagram fragments.
853: */
1.8 mycroft 854: void
1.1 cgd 855: ip_drain()
856: {
857:
1.75 thorpej 858: /*
859: * We may be called from a device's interrupt context. If
860: * the ipq is already busy, just bail out now.
861: */
862: if (ipq_lock_try() == 0)
863: return;
864:
1.25 cgd 865: while (ipq.lh_first != NULL) {
1.1 cgd 866: ipstat.ips_fragdropped++;
1.25 cgd 867: ip_freef(ipq.lh_first);
1.1 cgd 868: }
1.75 thorpej 869:
870: IPQ_UNLOCK();
1.1 cgd 871: }
872:
873: /*
874: * Do option processing on a datagram,
875: * possibly discarding it if bad options are encountered,
876: * or forwarding it if source-routed.
877: * Returns 1 if packet has been forwarded/freed,
878: * 0 if the packet should be processed further.
879: */
1.8 mycroft 880: int
1.1 cgd 881: ip_dooptions(m)
882: struct mbuf *m;
883: {
884: register struct ip *ip = mtod(m, struct ip *);
1.82.2.5 he 885: register u_char *cp, *cp0;
1.1 cgd 886: register struct ip_timestamp *ipt;
887: register struct in_ifaddr *ia;
888: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.82.2.5 he 889: struct in_addr dst;
1.1 cgd 890: n_time ntime;
891:
1.13 mycroft 892: dst = ip->ip_dst;
1.1 cgd 893: cp = (u_char *)(ip + 1);
894: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
895: for (; cnt > 0; cnt -= optlen, cp += optlen) {
896: opt = cp[IPOPT_OPTVAL];
897: if (opt == IPOPT_EOL)
898: break;
899: if (opt == IPOPT_NOP)
900: optlen = 1;
901: else {
902: optlen = cp[IPOPT_OLEN];
903: if (optlen <= 0 || optlen > cnt) {
904: code = &cp[IPOPT_OLEN] - (u_char *)ip;
905: goto bad;
906: }
907: }
908: switch (opt) {
909:
910: default:
911: break;
912:
913: /*
914: * Source routing with record.
915: * Find interface with current destination address.
916: * If none on this machine then drop if strictly routed,
917: * or do nothing if loosely routed.
918: * Record interface address and bring up next address
919: * component. If strictly routed make sure next
920: * address is on directly accessible net.
921: */
922: case IPOPT_LSRR:
923: case IPOPT_SSRR:
1.47 cjs 924: if (ip_allowsrcrt == 0) {
925: type = ICMP_UNREACH;
926: code = ICMP_UNREACH_NET_PROHIB;
927: goto bad;
928: }
1.1 cgd 929: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
930: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
931: goto bad;
932: }
933: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 934: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 935: if (ia == 0) {
936: if (opt == IPOPT_SSRR) {
937: type = ICMP_UNREACH;
938: code = ICMP_UNREACH_SRCFAIL;
939: goto bad;
940: }
941: /*
942: * Loose routing, and not at next destination
943: * yet; nothing to do except forward.
944: */
945: break;
946: }
947: off--; /* 0 origin */
1.82.2.6 he 948: if ((off + sizeof(struct in_addr)) > optlen) {
1.1 cgd 949: /*
950: * End of source route. Should be for us.
951: */
952: save_rte(cp, ip->ip_src);
953: break;
954: }
955: /*
956: * locate outgoing interface
957: */
958: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
959: sizeof(ipaddr.sin_addr));
960: if (opt == IPOPT_SSRR) {
961: #define INA struct in_ifaddr *
962: #define SA struct sockaddr *
1.29 mrg 963: ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1 cgd 964: } else
965: ia = ip_rtaddr(ipaddr.sin_addr);
966: if (ia == 0) {
967: type = ICMP_UNREACH;
968: code = ICMP_UNREACH_SRCFAIL;
969: goto bad;
970: }
971: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 972: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 973: (caddr_t)(cp + off), sizeof(struct in_addr));
974: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 975: /*
976: * Let ip_intr's mcast routing check handle mcast pkts
977: */
1.18 mycroft 978: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 979: break;
980:
981: case IPOPT_RR:
982: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
983: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
984: goto bad;
985: }
986: /*
987: * If no space remains, ignore.
988: */
989: off--; /* 0 origin */
1.82.2.6 he 990: if ((off + sizeof(struct in_addr)) > optlen)
1.1 cgd 991: break;
992: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
993: sizeof(ipaddr.sin_addr));
994: /*
995: * locate outgoing interface; if we're the destination,
996: * use the incoming interface (should be same).
997: */
998: if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
999: (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1000: type = ICMP_UNREACH;
1001: code = ICMP_UNREACH_HOST;
1002: goto bad;
1003: }
1.20 mycroft 1004: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 1005: (caddr_t)(cp + off), sizeof(struct in_addr));
1006: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1007: break;
1008:
1009: case IPOPT_TS:
1010: code = cp - (u_char *)ip;
1011: ipt = (struct ip_timestamp *)cp;
1012: if (ipt->ipt_len < 5)
1013: goto bad;
1.15 cgd 1014: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 1015: if (++ipt->ipt_oflw == 0)
1016: goto bad;
1017: break;
1018: }
1.82.2.5 he 1019: cp0 = (cp + ipt->ipt_ptr - 1);
1.1 cgd 1020: switch (ipt->ipt_flg) {
1021:
1022: case IPOPT_TS_TSONLY:
1023: break;
1024:
1025: case IPOPT_TS_TSANDADDR:
1.66 thorpej 1026: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1027: sizeof(struct in_addr) > ipt->ipt_len)
1028: goto bad;
1.13 mycroft 1029: ipaddr.sin_addr = dst;
1030: ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1031: m->m_pkthdr.rcvif);
1032: if (ia == 0)
1033: continue;
1.82.2.5 he 1034: bcopy(&ia->ia_addr.sin_addr,
1035: cp0, sizeof(struct in_addr));
1.1 cgd 1036: ipt->ipt_ptr += sizeof(struct in_addr);
1037: break;
1038:
1039: case IPOPT_TS_PRESPEC:
1.66 thorpej 1040: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 1041: sizeof(struct in_addr) > ipt->ipt_len)
1042: goto bad;
1.82.2.5 he 1043: bcopy(cp0, &ipaddr.sin_addr,
1.1 cgd 1044: sizeof(struct in_addr));
1045: if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1046: continue;
1047: ipt->ipt_ptr += sizeof(struct in_addr);
1048: break;
1049:
1050: default:
1051: goto bad;
1052: }
1053: ntime = iptime();
1.82.2.5 he 1054: cp0 = (u_char *) &ntime; /* XXX GCC BUG */
1055: bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1,
1.1 cgd 1056: sizeof(n_time));
1057: ipt->ipt_ptr += sizeof(n_time);
1058: }
1059: }
1060: if (forward) {
1.26 thorpej 1061: if (ip_forwsrcrt == 0) {
1062: type = ICMP_UNREACH;
1063: code = ICMP_UNREACH_SRCFAIL;
1064: goto bad;
1065: }
1.1 cgd 1066: ip_forward(m, 1);
1067: return (1);
1.13 mycroft 1068: }
1069: return (0);
1.1 cgd 1070: bad:
1.13 mycroft 1071: icmp_error(m, type, code, 0, 0);
1072: ipstat.ips_badoptions++;
1.1 cgd 1073: return (1);
1074: }
1075:
1076: /*
1077: * Given address of next destination (final or next hop),
1078: * return internet address info of interface to be used to get there.
1079: */
1080: struct in_ifaddr *
1081: ip_rtaddr(dst)
1082: struct in_addr dst;
1083: {
1084: register struct sockaddr_in *sin;
1085:
1.19 mycroft 1086: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1087:
1.35 mycroft 1088: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 1089: if (ipforward_rt.ro_rt) {
1090: RTFREE(ipforward_rt.ro_rt);
1091: ipforward_rt.ro_rt = 0;
1092: }
1093: sin->sin_family = AF_INET;
1094: sin->sin_len = sizeof(*sin);
1095: sin->sin_addr = dst;
1096:
1097: rtalloc(&ipforward_rt);
1098: }
1099: if (ipforward_rt.ro_rt == 0)
1100: return ((struct in_ifaddr *)0);
1.19 mycroft 1101: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 1102: }
1103:
1104: /*
1105: * Save incoming source route for use in replies,
1106: * to be picked up later by ip_srcroute if the receiver is interested.
1107: */
1.13 mycroft 1108: void
1.1 cgd 1109: save_rte(option, dst)
1110: u_char *option;
1111: struct in_addr dst;
1112: {
1113: unsigned olen;
1114:
1115: olen = option[IPOPT_OLEN];
1116: #ifdef DIAGNOSTIC
1117: if (ipprintfs)
1.39 christos 1118: printf("save_rte: olen %d\n", olen);
1.1 cgd 1119: #endif
1120: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1121: return;
1122: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
1123: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1124: ip_srcrt.dst = dst;
1125: }
1126:
1127: /*
1128: * Retrieve incoming source route for use in replies,
1129: * in the same form used by setsockopt.
1130: * The first hop is placed before the options, will be removed later.
1131: */
1132: struct mbuf *
1133: ip_srcroute()
1134: {
1135: register struct in_addr *p, *q;
1136: register struct mbuf *m;
1137:
1138: if (ip_nhops == 0)
1139: return ((struct mbuf *)0);
1140: m = m_get(M_DONTWAIT, MT_SOOPTS);
1141: if (m == 0)
1142: return ((struct mbuf *)0);
1143:
1.13 mycroft 1144: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1145:
1146: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1147: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1148: OPTSIZ;
1149: #ifdef DIAGNOSTIC
1150: if (ipprintfs)
1.39 christos 1151: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1152: #endif
1153:
1154: /*
1155: * First save first hop for return route
1156: */
1157: p = &ip_srcrt.route[ip_nhops - 1];
1158: *(mtod(m, struct in_addr *)) = *p--;
1159: #ifdef DIAGNOSTIC
1160: if (ipprintfs)
1.39 christos 1161: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1162: #endif
1163:
1164: /*
1165: * Copy option fields and padding (nop) to mbuf.
1166: */
1167: ip_srcrt.nop = IPOPT_NOP;
1168: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1169: bcopy((caddr_t)&ip_srcrt.nop,
1170: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1171: q = (struct in_addr *)(mtod(m, caddr_t) +
1172: sizeof(struct in_addr) + OPTSIZ);
1173: #undef OPTSIZ
1174: /*
1175: * Record return path as an IP source route,
1176: * reversing the path (pointers are now aligned).
1177: */
1178: while (p >= ip_srcrt.route) {
1179: #ifdef DIAGNOSTIC
1180: if (ipprintfs)
1.39 christos 1181: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1182: #endif
1183: *q++ = *p--;
1184: }
1185: /*
1186: * Last hop goes to final destination.
1187: */
1188: *q = ip_srcrt.dst;
1189: #ifdef DIAGNOSTIC
1190: if (ipprintfs)
1.39 christos 1191: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1192: #endif
1193: return (m);
1194: }
1195:
1196: /*
1197: * Strip out IP options, at higher
1198: * level protocol in the kernel.
1199: * Second argument is buffer to which options
1200: * will be moved, and return value is their length.
1201: * XXX should be deleted; last arg currently ignored.
1202: */
1.8 mycroft 1203: void
1.1 cgd 1204: ip_stripoptions(m, mopt)
1205: register struct mbuf *m;
1206: struct mbuf *mopt;
1207: {
1208: register int i;
1209: struct ip *ip = mtod(m, struct ip *);
1210: register caddr_t opts;
1211: int olen;
1212:
1.79 mycroft 1213: olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1 cgd 1214: opts = (caddr_t)(ip + 1);
1215: i = m->m_len - (sizeof (struct ip) + olen);
1216: bcopy(opts + olen, opts, (unsigned)i);
1217: m->m_len -= olen;
1218: if (m->m_flags & M_PKTHDR)
1219: m->m_pkthdr.len -= olen;
1.79 mycroft 1220: ip->ip_len -= olen;
1221: ip->ip_hl = sizeof (struct ip) >> 2;
1.1 cgd 1222: }
1223:
1.23 mycroft 1224: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1225: 0, 0, 0, 0,
1226: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1227: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1228: EMSGSIZE, EHOSTUNREACH, 0, 0,
1229: 0, 0, 0, 0,
1230: ENOPROTOOPT
1231: };
1232:
1233: /*
1234: * Forward a packet. If some error occurs return the sender
1235: * an icmp packet. Note we can't always generate a meaningful
1236: * icmp message because icmp doesn't have a large enough repertoire
1237: * of codes and types.
1238: *
1239: * If not forwarding, just drop the packet. This could be confusing
1240: * if ipforwarding was zero but some routing protocol was advancing
1241: * us as a gateway to somewhere. However, we must let the routing
1242: * protocol deal with that.
1243: *
1244: * The srcrt parameter indicates whether the packet is being forwarded
1245: * via a source route.
1246: */
1.13 mycroft 1247: void
1.1 cgd 1248: ip_forward(m, srcrt)
1249: struct mbuf *m;
1250: int srcrt;
1251: {
1252: register struct ip *ip = mtod(m, struct ip *);
1253: register struct sockaddr_in *sin;
1254: register struct rtentry *rt;
1.28 christos 1255: int error, type = 0, code = 0;
1.1 cgd 1256: struct mbuf *mcopy;
1.13 mycroft 1257: n_long dest;
1258: struct ifnet *destifp;
1.1 cgd 1259:
1.13 mycroft 1260: dest = 0;
1.1 cgd 1261: #ifdef DIAGNOSTIC
1262: if (ipprintfs)
1.70 thorpej 1263: printf("forward: src %2.2x dst %2.2x ttl %x\n",
1264: ntohl(ip->ip_src.s_addr),
1265: ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1 cgd 1266: #endif
1.82.2.3 cgd 1267: if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1.1 cgd 1268: ipstat.ips_cantforward++;
1269: m_freem(m);
1270: return;
1271: }
1272: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1273: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1274: return;
1275: }
1276: ip->ip_ttl -= IPTTLDEC;
1277:
1.19 mycroft 1278: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1279: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1280: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1281: if (ipforward_rt.ro_rt) {
1282: RTFREE(ipforward_rt.ro_rt);
1283: ipforward_rt.ro_rt = 0;
1284: }
1285: sin->sin_family = AF_INET;
1.35 mycroft 1286: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1287: sin->sin_addr = ip->ip_dst;
1288:
1289: rtalloc(&ipforward_rt);
1290: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1291: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1292: return;
1293: }
1294: rt = ipforward_rt.ro_rt;
1295: }
1296:
1297: /*
1.34 mycroft 1298: * Save at most 68 bytes of the packet in case
1.1 cgd 1299: * we need to generate an ICMP message to the src.
1300: */
1.34 mycroft 1301: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1302:
1303: /*
1304: * If forwarding packet using same interface that it came in on,
1305: * perhaps should send a redirect to sender to shortcut a hop.
1306: * Only send redirect if source is sending directly to us,
1307: * and if packet was not source routed (or has any options).
1308: * Also, don't send redirect if forwarding using a default route
1309: * or a route modified by a redirect.
1310: */
1311: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1312: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1313: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1314: ipsendredirects && !srcrt) {
1.19 mycroft 1315: if (rt->rt_ifa &&
1316: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1317: ifatoia(rt->rt_ifa)->ia_subnet) {
1.77 thorpej 1318: if (rt->rt_flags & RTF_GATEWAY)
1319: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1320: else
1321: dest = ip->ip_dst.s_addr;
1322: /*
1323: * Router requirements says to only send host
1324: * redirects.
1325: */
1326: type = ICMP_REDIRECT;
1327: code = ICMP_REDIRECT_HOST;
1.1 cgd 1328: #ifdef DIAGNOSTIC
1.77 thorpej 1329: if (ipprintfs)
1330: printf("redirect (%d) to %x\n", code,
1331: (u_int32_t)dest);
1.1 cgd 1332: #endif
1333: }
1334: }
1335:
1.27 thorpej 1336: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1337: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1338: if (error)
1339: ipstat.ips_cantforward++;
1340: else {
1341: ipstat.ips_forward++;
1342: if (type)
1343: ipstat.ips_redirectsent++;
1344: else {
1.63 matt 1345: if (mcopy) {
1346: #ifdef GATEWAY
1.64 thorpej 1347: if (mcopy->m_flags & M_CANFASTFWD)
1348: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1349: #endif
1.1 cgd 1350: m_freem(mcopy);
1.63 matt 1351: }
1.1 cgd 1352: return;
1353: }
1354: }
1355: if (mcopy == NULL)
1356: return;
1.13 mycroft 1357: destifp = NULL;
1358:
1.1 cgd 1359: switch (error) {
1360:
1361: case 0: /* forwarded, but need redirect */
1362: /* type, code set above */
1363: break;
1364:
1365: case ENETUNREACH: /* shouldn't happen, checked above */
1366: case EHOSTUNREACH:
1367: case ENETDOWN:
1368: case EHOSTDOWN:
1369: default:
1370: type = ICMP_UNREACH;
1371: code = ICMP_UNREACH_HOST;
1372: break;
1373:
1374: case EMSGSIZE:
1375: type = ICMP_UNREACH;
1376: code = ICMP_UNREACH_NEEDFRAG;
1.13 mycroft 1377: if (ipforward_rt.ro_rt)
1378: destifp = ipforward_rt.ro_rt->rt_ifp;
1.1 cgd 1379: ipstat.ips_cantfrag++;
1380: break;
1381:
1382: case ENOBUFS:
1383: type = ICMP_SOURCEQUENCH;
1384: code = 0;
1385: break;
1386: }
1.13 mycroft 1387: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1388: }
1389:
1390: void
1391: ip_savecontrol(inp, mp, ip, m)
1392: register struct inpcb *inp;
1393: register struct mbuf **mp;
1394: register struct ip *ip;
1395: register struct mbuf *m;
1396: {
1397:
1398: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1399: struct timeval tv;
1400:
1401: microtime(&tv);
1402: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1403: SCM_TIMESTAMP, SOL_SOCKET);
1404: if (*mp)
1405: mp = &(*mp)->m_next;
1406: }
1407: if (inp->inp_flags & INP_RECVDSTADDR) {
1408: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1409: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1410: if (*mp)
1411: mp = &(*mp)->m_next;
1412: }
1413: #ifdef notyet
1414: /*
1415: * XXX
1416: * Moving these out of udp_input() made them even more broken
1417: * than they already were.
1418: * - fenner@parc.xerox.com
1419: */
1420: /* options were tossed already */
1421: if (inp->inp_flags & INP_RECVOPTS) {
1422: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1423: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1424: if (*mp)
1425: mp = &(*mp)->m_next;
1426: }
1427: /* ip_srcroute doesn't do what we want here, need to fix */
1428: if (inp->inp_flags & INP_RECVRETOPTS) {
1429: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1430: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1431: if (*mp)
1432: mp = &(*mp)->m_next;
1433: }
1434: #endif
1435: if (inp->inp_flags & INP_RECVIF) {
1436: struct sockaddr_dl sdl;
1437:
1438: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1439: sdl.sdl_family = AF_LINK;
1440: sdl.sdl_index = m->m_pkthdr.rcvif ?
1441: m->m_pkthdr.rcvif->if_index : 0;
1442: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1443: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1444: IP_RECVIF, IPPROTO_IP);
1445: if (*mp)
1446: mp = &(*mp)->m_next;
1447: }
1.13 mycroft 1448: }
1449:
1450: int
1451: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1452: int *name;
1453: u_int namelen;
1454: void *oldp;
1455: size_t *oldlenp;
1456: void *newp;
1457: size_t newlen;
1458: {
1.52 thorpej 1459: extern int subnetsarelocal;
1460:
1.54 lukem 1461: int error, old;
1462:
1.13 mycroft 1463: /* All sysctl names at this level are terminal. */
1464: if (namelen != 1)
1465: return (ENOTDIR);
1466:
1467: switch (name[0]) {
1468: case IPCTL_FORWARDING:
1469: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1470: case IPCTL_SENDREDIRECTS:
1471: return (sysctl_int(oldp, oldlenp, newp, newlen,
1472: &ipsendredirects));
1473: case IPCTL_DEFTTL:
1474: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1475: #ifdef notyet
1476: case IPCTL_DEFMTU:
1477: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1478: #endif
1.26 thorpej 1479: case IPCTL_FORWSRCRT:
1.47 cjs 1480: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1481: if (securelevel > 0)
1.46 cjs 1482: return (sysctl_rdint(oldp, oldlenp, newp,
1483: ip_forwsrcrt));
1484: else
1485: return (sysctl_int(oldp, oldlenp, newp, newlen,
1486: &ip_forwsrcrt));
1.27 thorpej 1487: case IPCTL_DIRECTEDBCAST:
1488: return (sysctl_int(oldp, oldlenp, newp, newlen,
1489: &ip_directedbcast));
1.47 cjs 1490: case IPCTL_ALLOWSRCRT:
1491: return (sysctl_int(oldp, oldlenp, newp, newlen,
1492: &ip_allowsrcrt));
1.52 thorpej 1493: case IPCTL_SUBNETSARELOCAL:
1494: return (sysctl_int(oldp, oldlenp, newp, newlen,
1495: &subnetsarelocal));
1.53 kml 1496: case IPCTL_MTUDISC:
1.60 kml 1497: error = sysctl_int(oldp, oldlenp, newp, newlen,
1498: &ip_mtudisc);
1499: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1500: ip_mtudisc_timeout_q =
1501: rt_timer_queue_create(ip_mtudisc_timeout);
1502: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1503: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1504: ip_mtudisc_timeout_q = NULL;
1505: }
1506: return error;
1.54 lukem 1507: case IPCTL_ANONPORTMIN:
1508: old = anonportmin;
1509: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1510: if (anonportmin >= anonportmax || anonportmin > 65535
1511: #ifndef IPNOPRIVPORTS
1512: || anonportmin < IPPORT_RESERVED
1513: #endif
1514: ) {
1515: anonportmin = old;
1516: return (EINVAL);
1517: }
1518: return (error);
1519: case IPCTL_ANONPORTMAX:
1520: old = anonportmax;
1521: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1522: if (anonportmin >= anonportmax || anonportmax > 65535
1523: #ifndef IPNOPRIVPORTS
1524: || anonportmax < IPPORT_RESERVED
1525: #endif
1526: ) {
1527: anonportmax = old;
1528: return (EINVAL);
1529: }
1.60 kml 1530: return (error);
1531: case IPCTL_MTUDISCTIMEOUT:
1532: error = sysctl_int(oldp, oldlenp, newp, newlen,
1533: &ip_mtudisc_timeout);
1534: if (ip_mtudisc_timeout_q != NULL)
1535: rt_timer_queue_change(ip_mtudisc_timeout_q,
1536: ip_mtudisc_timeout);
1.54 lukem 1537: return (error);
1.65 matt 1538: #ifdef GATEWAY
1539: case IPCTL_MAXFLOWS:
1.67 thorpej 1540: {
1541: int s;
1542:
1.65 matt 1543: error = sysctl_int(oldp, oldlenp, newp, newlen,
1544: &ip_maxflows);
1.67 thorpej 1545: s = splsoftnet();
1.65 matt 1546: ipflow_reap(0);
1.67 thorpej 1547: splx(s);
1.65 matt 1548: return (error);
1.67 thorpej 1549: }
1.65 matt 1550: #endif
1.82.2.7! he 1551:
! 1552: case IPCTL_MAXFRAGPACKETS:
! 1553: return (sysctl_int(oldp, oldlenp, newp, newlen,
! 1554: &ip_maxfragpackets));
! 1555:
1.13 mycroft 1556: default:
1557: return (EOPNOTSUPP);
1558: }
1559: /* NOTREACHED */
1.1 cgd 1560: }
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