Annotation of src/sys/netinet/ip_input.c, Revision 1.66
1.66 ! thorpej 1: /* $NetBSD: ip_input.c,v 1.65 1998/05/04 19:24:53 matt Exp $ */
1.58 tls 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"
1.55 scottr 76: #include "opt_mrouting.h"
1.1 cgd 77:
1.5 mycroft 78: #include <sys/param.h>
79: #include <sys/systm.h>
80: #include <sys/malloc.h>
81: #include <sys/mbuf.h>
82: #include <sys/domain.h>
83: #include <sys/protosw.h>
84: #include <sys/socket.h>
1.44 thorpej 85: #include <sys/socketvar.h>
1.5 mycroft 86: #include <sys/errno.h>
87: #include <sys/time.h>
88: #include <sys/kernel.h>
1.28 christos 89: #include <sys/proc.h>
90:
91: #include <vm/vm.h>
92: #include <sys/sysctl.h>
1.1 cgd 93:
1.5 mycroft 94: #include <net/if.h>
1.44 thorpej 95: #include <net/if_dl.h>
1.5 mycroft 96: #include <net/route.h>
1.45 mrg 97: #include <net/pfil.h>
1.1 cgd 98:
1.5 mycroft 99: #include <netinet/in.h>
100: #include <netinet/in_systm.h>
101: #include <netinet/ip.h>
102: #include <netinet/in_pcb.h>
103: #include <netinet/in_var.h>
104: #include <netinet/ip_var.h>
105: #include <netinet/ip_icmp.h>
1.44 thorpej 106:
1.1 cgd 107: #ifndef IPFORWARDING
108: #ifdef GATEWAY
109: #define IPFORWARDING 1 /* forward IP packets not for us */
110: #else /* GATEWAY */
111: #define IPFORWARDING 0 /* don't forward IP packets not for us */
112: #endif /* GATEWAY */
113: #endif /* IPFORWARDING */
114: #ifndef IPSENDREDIRECTS
115: #define IPSENDREDIRECTS 1
116: #endif
1.26 thorpej 117: #ifndef IPFORWSRCRT
1.47 cjs 118: #define IPFORWSRCRT 1 /* forward source-routed packets */
119: #endif
120: #ifndef IPALLOWSRCRT
1.48 mrg 121: #define IPALLOWSRCRT 1 /* allow source-routed packets */
1.26 thorpej 122: #endif
1.53 kml 123: #ifndef IPMTUDISC
124: #define IPMTUDISC 0
125: #endif
1.60 kml 126: #ifndef IPMTUDISCTIMEOUT
1.61 kml 127: #define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
1.60 kml 128: #endif
1.53 kml 129:
1.27 thorpej 130: /*
131: * Note: DIRECTED_BROADCAST is handled this way so that previous
132: * configuration using this option will Just Work.
133: */
134: #ifndef IPDIRECTEDBCAST
135: #ifdef DIRECTED_BROADCAST
136: #define IPDIRECTEDBCAST 1
137: #else
138: #define IPDIRECTEDBCAST 0
139: #endif /* DIRECTED_BROADCAST */
140: #endif /* IPDIRECTEDBCAST */
1.1 cgd 141: int ipforwarding = IPFORWARDING;
142: int ipsendredirects = IPSENDREDIRECTS;
1.13 mycroft 143: int ip_defttl = IPDEFTTL;
1.26 thorpej 144: int ip_forwsrcrt = IPFORWSRCRT;
1.27 thorpej 145: int ip_directedbcast = IPDIRECTEDBCAST;
1.47 cjs 146: int ip_allowsrcrt = IPALLOWSRCRT;
1.53 kml 147: int ip_mtudisc = IPMTUDISC;
1.60 kml 148: u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1 cgd 149: #ifdef DIAGNOSTIC
150: int ipprintfs = 0;
151: #endif
152:
1.60 kml 153: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
154:
1.1 cgd 155: extern struct domain inetdomain;
156: extern struct protosw inetsw[];
157: u_char ip_protox[IPPROTO_MAX];
158: int ipqmaxlen = IFQ_MAXLEN;
1.22 mycroft 159: struct in_ifaddrhead in_ifaddr;
1.57 tls 160: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.13 mycroft 161: struct ifqueue ipintrq;
1.63 matt 162: struct ipstat ipstat;
163: u_int16_t ip_id;
164: int ip_defttl;
165: struct ipqhead ipq;
1.1 cgd 166:
167: /*
168: * We need to save the IP options in case a protocol wants to respond
169: * to an incoming packet over the same route if the packet got here
170: * using IP source routing. This allows connection establishment and
171: * maintenance when the remote end is on a network that is not known
172: * to us.
173: */
174: int ip_nhops = 0;
175: static struct ip_srcrt {
176: struct in_addr dst; /* final destination */
177: char nop; /* one NOP to align */
178: char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
179: struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
180: } ip_srcrt;
181:
1.13 mycroft 182: static void save_rte __P((u_char *, struct in_addr));
1.35 mycroft 183:
1.1 cgd 184: /*
185: * IP initialization: fill in IP protocol switch table.
186: * All protocols not implemented in kernel go to raw IP protocol handler.
187: */
1.8 mycroft 188: void
1.1 cgd 189: ip_init()
190: {
191: register struct protosw *pr;
192: register int i;
193:
194: pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
195: if (pr == 0)
196: panic("ip_init");
197: for (i = 0; i < IPPROTO_MAX; i++)
198: ip_protox[i] = pr - inetsw;
199: for (pr = inetdomain.dom_protosw;
200: pr < inetdomain.dom_protoswNPROTOSW; pr++)
201: if (pr->pr_domain->dom_family == PF_INET &&
202: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
203: ip_protox[pr->pr_protocol] = pr - inetsw;
1.25 cgd 204: LIST_INIT(&ipq);
1.1 cgd 205: ip_id = time.tv_sec & 0xffff;
206: ipintrq.ifq_maxlen = ipqmaxlen;
1.22 mycroft 207: TAILQ_INIT(&in_ifaddr);
1.57 tls 208: in_ifaddrhashtbl =
209: hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash);
1.60 kml 210: if (ip_mtudisc != 0)
211: ip_mtudisc_timeout_q =
212: rt_timer_queue_create(ip_mtudisc_timeout);
1.1 cgd 213: }
214:
215: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
216: struct route ipforward_rt;
217:
218: /*
219: * Ip input routine. Checksum and byte swap header. If fragmented
220: * try to reassemble. Process options. Pass to next level.
221: */
1.8 mycroft 222: void
1.1 cgd 223: ipintr()
224: {
1.33 mrg 225: register struct ip *ip = NULL;
1.1 cgd 226: register struct mbuf *m;
227: register struct ipq *fp;
228: register struct in_ifaddr *ia;
1.57 tls 229: register struct ifaddr *ifa;
1.25 cgd 230: struct ipqent *ipqe;
1.35 mycroft 231: int hlen = 0, mff, len, s;
1.36 mrg 232: #ifdef PFIL_HOOKS
1.33 mrg 233: struct packet_filter_hook *pfh;
234: struct mbuf *m0;
1.43 mrg 235: int rv;
1.36 mrg 236: #endif /* PFIL_HOOKS */
1.1 cgd 237:
238: next:
239: /*
240: * Get next datagram off input queue and get IP header
241: * in first mbuf.
242: */
243: s = splimp();
244: IF_DEQUEUE(&ipintrq, m);
245: splx(s);
1.13 mycroft 246: if (m == 0)
1.1 cgd 247: return;
248: #ifdef DIAGNOSTIC
249: if ((m->m_flags & M_PKTHDR) == 0)
250: panic("ipintr no HDR");
251: #endif
252: /*
253: * If no IP addresses have been set yet but the interfaces
254: * are receiving, can't do anything with incoming packets yet.
255: */
1.22 mycroft 256: if (in_ifaddr.tqh_first == 0)
1.1 cgd 257: goto bad;
258: ipstat.ips_total++;
259: if (m->m_len < sizeof (struct ip) &&
260: (m = m_pullup(m, sizeof (struct ip))) == 0) {
261: ipstat.ips_toosmall++;
262: goto next;
263: }
264: ip = mtod(m, struct ip *);
1.13 mycroft 265: if (ip->ip_v != IPVERSION) {
266: ipstat.ips_badvers++;
267: goto bad;
268: }
1.1 cgd 269: hlen = ip->ip_hl << 2;
270: if (hlen < sizeof(struct ip)) { /* minimum header length */
271: ipstat.ips_badhlen++;
272: goto bad;
273: }
274: if (hlen > m->m_len) {
275: if ((m = m_pullup(m, hlen)) == 0) {
276: ipstat.ips_badhlen++;
277: goto next;
278: }
279: ip = mtod(m, struct ip *);
280: }
1.28 christos 281: if ((ip->ip_sum = in_cksum(m, hlen)) != 0) {
1.1 cgd 282: ipstat.ips_badsum++;
283: goto bad;
284: }
285:
286: /*
287: * Convert fields to host representation.
288: */
289: NTOHS(ip->ip_len);
290: NTOHS(ip->ip_id);
291: NTOHS(ip->ip_off);
1.35 mycroft 292: len = ip->ip_len;
1.1 cgd 293:
294: /*
295: * Check that the amount of data in the buffers
296: * is as at least much as the IP header would have us expect.
297: * Trim mbufs if longer than we expect.
298: * Drop packet if shorter than we expect.
299: */
1.35 mycroft 300: if (m->m_pkthdr.len < len) {
1.1 cgd 301: ipstat.ips_tooshort++;
302: goto bad;
303: }
1.35 mycroft 304: if (m->m_pkthdr.len > len) {
1.1 cgd 305: if (m->m_len == m->m_pkthdr.len) {
1.35 mycroft 306: m->m_len = len;
307: m->m_pkthdr.len = len;
1.1 cgd 308: } else
1.35 mycroft 309: m_adj(m, len - m->m_pkthdr.len);
1.1 cgd 310: }
311:
1.64 thorpej 312: /*
313: * Assume that we can create a fast-forward IP flow entry
314: * based on this packet.
315: */
316: m->m_flags |= M_CANFASTFWD;
317:
1.36 mrg 318: #ifdef PFIL_HOOKS
1.33 mrg 319: /*
1.64 thorpej 320: * Run through list of hooks for input packets. If there are any
321: * filters which require that additional packets in the flow are
322: * not fast-forwarded, they must clear the M_CANFASTFWD flag.
323: * Note that filters must _never_ set this flag, as another filter
324: * in the list may have previously cleared it.
1.33 mrg 325: */
326: m0 = m;
1.59 mrg 327: for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33 mrg 328: if (pfh->pfil_func) {
1.43 mrg 329: rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
330: if (rv)
1.40 veego 331: goto next;
1.49 christos 332: ip = mtod(m = m0, struct ip *);
1.33 mrg 333: }
1.36 mrg 334: #endif /* PFIL_HOOKS */
1.33 mrg 335:
1.1 cgd 336: /*
337: * Process options and, if not destined for us,
338: * ship it on. ip_dooptions returns 1 when an
339: * error was detected (causing an icmp message
340: * to be sent and the original packet to be freed).
341: */
342: ip_nhops = 0; /* for source routed packets */
343: if (hlen > sizeof (struct ip) && ip_dooptions(m))
344: goto next;
345:
346: /*
347: * Check our list of addresses, to see if the packet is for us.
348: */
1.57 tls 349: INADDR_TO_IA(ip->ip_dst, ia);
350: if (ia != NULL) goto ours;
351: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
352: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
353: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
354: if (ifa->ifa_addr->sa_family != AF_INET) continue;
355: ia = ifatoia(ifa);
1.35 mycroft 356: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
357: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 358: /*
359: * Look for all-0's host part (old broadcast addr),
360: * either for subnet or net.
361: */
362: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 363: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 364: goto ours;
1.57 tls 365: /*
366: * An interface with IP address zero accepts
367: * all packets that arrive on that interface.
368: */
369: if (in_nullhost(ia->ia_addr.sin_addr))
370: goto ours;
1.1 cgd 371: }
372: }
1.18 mycroft 373: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 374: struct in_multi *inm;
375: #ifdef MROUTING
376: extern struct socket *ip_mrouter;
1.10 brezak 377:
378: if (m->m_flags & M_EXT) {
379: if ((m = m_pullup(m, hlen)) == 0) {
380: ipstat.ips_toosmall++;
381: goto next;
382: }
383: ip = mtod(m, struct ip *);
384: }
1.4 hpeyerl 385:
386: if (ip_mrouter) {
387: /*
388: * If we are acting as a multicast router, all
389: * incoming multicast packets are passed to the
390: * kernel-level multicast forwarding function.
391: * The packet is returned (relatively) intact; if
392: * ip_mforward() returns a non-zero value, the packet
393: * must be discarded, else it may be accepted below.
394: *
395: * (The IP ident field is put in the same byte order
396: * as expected when ip_mforward() is called from
397: * ip_output().)
398: */
399: ip->ip_id = htons(ip->ip_id);
1.13 mycroft 400: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
401: ipstat.ips_cantforward++;
1.4 hpeyerl 402: m_freem(m);
403: goto next;
404: }
405: ip->ip_id = ntohs(ip->ip_id);
406:
407: /*
408: * The process-level routing demon needs to receive
409: * all multicast IGMP packets, whether or not this
410: * host belongs to their destination groups.
411: */
412: if (ip->ip_p == IPPROTO_IGMP)
413: goto ours;
1.13 mycroft 414: ipstat.ips_forward++;
1.4 hpeyerl 415: }
416: #endif
417: /*
418: * See if we belong to the destination multicast group on the
419: * arrival interface.
420: */
421: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
422: if (inm == NULL) {
1.13 mycroft 423: ipstat.ips_cantforward++;
1.4 hpeyerl 424: m_freem(m);
425: goto next;
426: }
427: goto ours;
428: }
1.19 mycroft 429: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 430: in_nullhost(ip->ip_dst))
1.1 cgd 431: goto ours;
432:
433: /*
434: * Not for us; forward if possible and desirable.
435: */
436: if (ipforwarding == 0) {
437: ipstat.ips_cantforward++;
438: m_freem(m);
439: } else
440: ip_forward(m, 0);
441: goto next;
442:
443: ours:
444: /*
445: * If offset or IP_MF are set, must reassemble.
446: * Otherwise, nothing need be done.
447: * (We could look in the reassembly queue to see
448: * if the packet was previously fragmented,
449: * but it's not worth the time; just let them time out.)
450: */
1.37 perry 451: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 452: /*
453: * Look for queue of fragments
454: * of this datagram.
455: */
1.25 cgd 456: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 457: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 458: in_hosteq(ip->ip_src, fp->ipq_src) &&
459: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 460: ip->ip_p == fp->ipq_p)
461: goto found;
462: fp = 0;
463: found:
464:
465: /*
466: * Adjust ip_len to not reflect header,
1.25 cgd 467: * set ipqe_mff if more fragments are expected,
1.1 cgd 468: * convert offset of this to bytes.
469: */
470: ip->ip_len -= hlen;
1.25 cgd 471: mff = (ip->ip_off & IP_MF) != 0;
472: if (mff) {
1.16 cgd 473: /*
474: * Make sure that fragments have a data length
475: * that's a non-zero multiple of 8 bytes.
476: */
1.17 cgd 477: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 478: ipstat.ips_badfrags++;
479: goto bad;
480: }
481: }
1.1 cgd 482: ip->ip_off <<= 3;
483:
484: /*
485: * If datagram marked as having more fragments
486: * or if this is not the first fragment,
487: * attempt reassembly; if it succeeds, proceed.
488: */
1.25 cgd 489: if (mff || ip->ip_off) {
1.1 cgd 490: ipstat.ips_fragments++;
1.25 cgd 491: MALLOC(ipqe, struct ipqent *, sizeof (struct ipqent),
492: M_IPQ, M_NOWAIT);
493: if (ipqe == NULL) {
494: ipstat.ips_rcvmemdrop++;
495: goto bad;
496: }
497: ipqe->ipqe_mff = mff;
1.50 thorpej 498: ipqe->ipqe_m = m;
1.25 cgd 499: ipqe->ipqe_ip = ip;
1.50 thorpej 500: m = ip_reass(ipqe, fp);
501: if (m == 0)
1.1 cgd 502: goto next;
1.13 mycroft 503: ipstat.ips_reassembled++;
1.50 thorpej 504: ip = mtod(m, struct ip *);
1.1 cgd 505: } else
506: if (fp)
507: ip_freef(fp);
508: } else
509: ip->ip_len -= hlen;
510:
511: /*
512: * Switch out to protocol's input routine.
513: */
514: ipstat.ips_delivered++;
515: (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
516: goto next;
517: bad:
518: m_freem(m);
519: goto next;
520: }
521:
522: /*
523: * Take incoming datagram fragment and try to
524: * reassemble it into whole datagram. If a chain for
525: * reassembly of this datagram already exists, then it
526: * is given as fp; otherwise have to make a chain.
527: */
1.50 thorpej 528: struct mbuf *
1.25 cgd 529: ip_reass(ipqe, fp)
530: register struct ipqent *ipqe;
1.1 cgd 531: register struct ipq *fp;
532: {
1.50 thorpej 533: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 534: register struct ipqent *nq, *p, *q;
535: struct ip *ip;
1.1 cgd 536: struct mbuf *t;
1.25 cgd 537: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 538: int i, next;
539:
540: /*
541: * Presence of header sizes in mbufs
542: * would confuse code below.
543: */
544: m->m_data += hlen;
545: m->m_len -= hlen;
546:
547: /*
548: * If first fragment to arrive, create a reassembly queue.
549: */
550: if (fp == 0) {
1.50 thorpej 551: MALLOC(fp, struct ipq *, sizeof (struct ipq),
552: M_FTABLE, M_NOWAIT);
553: if (fp == NULL)
1.1 cgd 554: goto dropfrag;
1.25 cgd 555: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 556: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 557: fp->ipq_p = ipqe->ipqe_ip->ip_p;
558: fp->ipq_id = ipqe->ipqe_ip->ip_id;
559: LIST_INIT(&fp->ipq_fragq);
560: fp->ipq_src = ipqe->ipqe_ip->ip_src;
561: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
562: p = NULL;
1.1 cgd 563: goto insert;
564: }
565:
566: /*
567: * Find a segment which begins after this one does.
568: */
1.25 cgd 569: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
570: p = q, q = q->ipqe_q.le_next)
571: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 572: break;
573:
574: /*
575: * If there is a preceding segment, it may provide some of
576: * our data already. If so, drop the data from the incoming
577: * segment. If it provides all of our data, drop us.
578: */
1.25 cgd 579: if (p != NULL) {
580: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
581: ipqe->ipqe_ip->ip_off;
1.1 cgd 582: if (i > 0) {
1.25 cgd 583: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 584: goto dropfrag;
1.50 thorpej 585: m_adj(ipqe->ipqe_m, i);
1.25 cgd 586: ipqe->ipqe_ip->ip_off += i;
587: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 588: }
589: }
590:
591: /*
592: * While we overlap succeeding segments trim them or,
593: * if they are completely covered, dequeue them.
594: */
1.25 cgd 595: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
596: q->ipqe_ip->ip_off; q = nq) {
597: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
598: q->ipqe_ip->ip_off;
599: if (i < q->ipqe_ip->ip_len) {
600: q->ipqe_ip->ip_len -= i;
601: q->ipqe_ip->ip_off += i;
1.50 thorpej 602: m_adj(q->ipqe_m, i);
1.1 cgd 603: break;
604: }
1.25 cgd 605: nq = q->ipqe_q.le_next;
1.50 thorpej 606: m_freem(q->ipqe_m);
1.25 cgd 607: LIST_REMOVE(q, ipqe_q);
608: FREE(q, M_IPQ);
1.1 cgd 609: }
610:
611: insert:
612: /*
613: * Stick new segment in its place;
614: * check for complete reassembly.
615: */
1.25 cgd 616: if (p == NULL) {
617: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
618: } else {
619: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
620: }
1.1 cgd 621: next = 0;
1.25 cgd 622: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
623: p = q, q = q->ipqe_q.le_next) {
624: if (q->ipqe_ip->ip_off != next)
1.1 cgd 625: return (0);
1.25 cgd 626: next += q->ipqe_ip->ip_len;
1.1 cgd 627: }
1.25 cgd 628: if (p->ipqe_mff)
1.1 cgd 629: return (0);
630:
631: /*
1.41 thorpej 632: * Reassembly is complete. Check for a bogus message size and
633: * concatenate fragments.
1.1 cgd 634: */
1.25 cgd 635: q = fp->ipq_fragq.lh_first;
636: ip = q->ipqe_ip;
1.41 thorpej 637: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
638: ipstat.ips_toolong++;
639: ip_freef(fp);
640: return (0);
641: }
1.50 thorpej 642: m = q->ipqe_m;
1.1 cgd 643: t = m->m_next;
644: m->m_next = 0;
645: m_cat(m, t);
1.25 cgd 646: nq = q->ipqe_q.le_next;
647: FREE(q, M_IPQ);
648: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 649: t = q->ipqe_m;
1.25 cgd 650: nq = q->ipqe_q.le_next;
651: FREE(q, M_IPQ);
1.1 cgd 652: m_cat(m, t);
653: }
654:
655: /*
656: * Create header for new ip packet by
657: * modifying header of first packet;
658: * dequeue and discard fragment reassembly header.
659: * Make header visible.
660: */
661: ip->ip_len = next;
1.25 cgd 662: ip->ip_src = fp->ipq_src;
663: ip->ip_dst = fp->ipq_dst;
664: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 665: FREE(fp, M_FTABLE);
1.1 cgd 666: m->m_len += (ip->ip_hl << 2);
667: m->m_data -= (ip->ip_hl << 2);
668: /* some debugging cruft by sklower, below, will go away soon */
669: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
670: register int plen = 0;
1.50 thorpej 671: for (t = m; t; t = t->m_next)
672: plen += t->m_len;
673: m->m_pkthdr.len = plen;
1.1 cgd 674: }
1.50 thorpej 675: return (m);
1.1 cgd 676:
677: dropfrag:
678: ipstat.ips_fragdropped++;
679: m_freem(m);
1.25 cgd 680: FREE(ipqe, M_IPQ);
1.1 cgd 681: return (0);
682: }
683:
684: /*
685: * Free a fragment reassembly header and all
686: * associated datagrams.
687: */
1.8 mycroft 688: void
1.1 cgd 689: ip_freef(fp)
690: struct ipq *fp;
691: {
1.25 cgd 692: register struct ipqent *q, *p;
1.1 cgd 693:
1.25 cgd 694: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
695: p = q->ipqe_q.le_next;
1.50 thorpej 696: m_freem(q->ipqe_m);
1.25 cgd 697: LIST_REMOVE(q, ipqe_q);
698: FREE(q, M_IPQ);
1.1 cgd 699: }
1.25 cgd 700: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 701: FREE(fp, M_FTABLE);
1.1 cgd 702: }
703:
704: /*
705: * IP timer processing;
706: * if a timer expires on a reassembly
707: * queue, discard it.
708: */
1.8 mycroft 709: void
1.1 cgd 710: ip_slowtimo()
711: {
1.25 cgd 712: register struct ipq *fp, *nfp;
1.24 mycroft 713: int s = splsoftnet();
1.1 cgd 714:
1.25 cgd 715: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
716: nfp = fp->ipq_q.le_next;
717: if (--fp->ipq_ttl == 0) {
1.1 cgd 718: ipstat.ips_fragtimeout++;
1.25 cgd 719: ip_freef(fp);
1.1 cgd 720: }
721: }
1.63 matt 722: #ifdef GATEWAY
723: ipflow_slowtimo();
724: #endif
1.1 cgd 725: splx(s);
726: }
727:
728: /*
729: * Drain off all datagram fragments.
730: */
1.8 mycroft 731: void
1.1 cgd 732: ip_drain()
733: {
734:
1.25 cgd 735: while (ipq.lh_first != NULL) {
1.1 cgd 736: ipstat.ips_fragdropped++;
1.25 cgd 737: ip_freef(ipq.lh_first);
1.1 cgd 738: }
739: }
740:
741: /*
742: * Do option processing on a datagram,
743: * possibly discarding it if bad options are encountered,
744: * or forwarding it if source-routed.
745: * Returns 1 if packet has been forwarded/freed,
746: * 0 if the packet should be processed further.
747: */
1.8 mycroft 748: int
1.1 cgd 749: ip_dooptions(m)
750: struct mbuf *m;
751: {
752: register struct ip *ip = mtod(m, struct ip *);
753: register u_char *cp;
754: register struct ip_timestamp *ipt;
755: register struct in_ifaddr *ia;
756: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13 mycroft 757: struct in_addr *sin, dst;
1.1 cgd 758: n_time ntime;
759:
1.13 mycroft 760: dst = ip->ip_dst;
1.1 cgd 761: cp = (u_char *)(ip + 1);
762: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
763: for (; cnt > 0; cnt -= optlen, cp += optlen) {
764: opt = cp[IPOPT_OPTVAL];
765: if (opt == IPOPT_EOL)
766: break;
767: if (opt == IPOPT_NOP)
768: optlen = 1;
769: else {
770: optlen = cp[IPOPT_OLEN];
771: if (optlen <= 0 || optlen > cnt) {
772: code = &cp[IPOPT_OLEN] - (u_char *)ip;
773: goto bad;
774: }
775: }
776: switch (opt) {
777:
778: default:
779: break;
780:
781: /*
782: * Source routing with record.
783: * Find interface with current destination address.
784: * If none on this machine then drop if strictly routed,
785: * or do nothing if loosely routed.
786: * Record interface address and bring up next address
787: * component. If strictly routed make sure next
788: * address is on directly accessible net.
789: */
790: case IPOPT_LSRR:
791: case IPOPT_SSRR:
1.47 cjs 792: if (ip_allowsrcrt == 0) {
793: type = ICMP_UNREACH;
794: code = ICMP_UNREACH_NET_PROHIB;
795: goto bad;
796: }
1.1 cgd 797: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
798: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
799: goto bad;
800: }
801: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 802: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 803: if (ia == 0) {
804: if (opt == IPOPT_SSRR) {
805: type = ICMP_UNREACH;
806: code = ICMP_UNREACH_SRCFAIL;
807: goto bad;
808: }
809: /*
810: * Loose routing, and not at next destination
811: * yet; nothing to do except forward.
812: */
813: break;
814: }
815: off--; /* 0 origin */
816: if (off > optlen - sizeof(struct in_addr)) {
817: /*
818: * End of source route. Should be for us.
819: */
820: save_rte(cp, ip->ip_src);
821: break;
822: }
823: /*
824: * locate outgoing interface
825: */
826: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
827: sizeof(ipaddr.sin_addr));
828: if (opt == IPOPT_SSRR) {
829: #define INA struct in_ifaddr *
830: #define SA struct sockaddr *
1.29 mrg 831: ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1 cgd 832: } else
833: ia = ip_rtaddr(ipaddr.sin_addr);
834: if (ia == 0) {
835: type = ICMP_UNREACH;
836: code = ICMP_UNREACH_SRCFAIL;
837: goto bad;
838: }
839: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 840: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 841: (caddr_t)(cp + off), sizeof(struct in_addr));
842: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 843: /*
844: * Let ip_intr's mcast routing check handle mcast pkts
845: */
1.18 mycroft 846: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 847: break;
848:
849: case IPOPT_RR:
850: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
851: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
852: goto bad;
853: }
854: /*
855: * If no space remains, ignore.
856: */
857: off--; /* 0 origin */
858: if (off > optlen - sizeof(struct in_addr))
859: break;
860: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
861: sizeof(ipaddr.sin_addr));
862: /*
863: * locate outgoing interface; if we're the destination,
864: * use the incoming interface (should be same).
865: */
866: if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
867: (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
868: type = ICMP_UNREACH;
869: code = ICMP_UNREACH_HOST;
870: goto bad;
871: }
1.20 mycroft 872: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 873: (caddr_t)(cp + off), sizeof(struct in_addr));
874: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
875: break;
876:
877: case IPOPT_TS:
878: code = cp - (u_char *)ip;
879: ipt = (struct ip_timestamp *)cp;
880: if (ipt->ipt_len < 5)
881: goto bad;
1.15 cgd 882: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 883: if (++ipt->ipt_oflw == 0)
884: goto bad;
885: break;
886: }
887: sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
888: switch (ipt->ipt_flg) {
889:
890: case IPOPT_TS_TSONLY:
891: break;
892:
893: case IPOPT_TS_TSANDADDR:
1.66 ! thorpej 894: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 895: sizeof(struct in_addr) > ipt->ipt_len)
896: goto bad;
1.13 mycroft 897: ipaddr.sin_addr = dst;
898: ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
899: m->m_pkthdr.rcvif);
900: if (ia == 0)
901: continue;
1.20 mycroft 902: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 903: (caddr_t)sin, sizeof(struct in_addr));
904: ipt->ipt_ptr += sizeof(struct in_addr);
905: break;
906:
907: case IPOPT_TS_PRESPEC:
1.66 ! thorpej 908: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 909: sizeof(struct in_addr) > ipt->ipt_len)
910: goto bad;
911: bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
912: sizeof(struct in_addr));
913: if (ifa_ifwithaddr((SA)&ipaddr) == 0)
914: continue;
915: ipt->ipt_ptr += sizeof(struct in_addr);
916: break;
917:
918: default:
919: goto bad;
920: }
921: ntime = iptime();
922: bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
923: sizeof(n_time));
924: ipt->ipt_ptr += sizeof(n_time);
925: }
926: }
927: if (forward) {
1.26 thorpej 928: if (ip_forwsrcrt == 0) {
929: type = ICMP_UNREACH;
930: code = ICMP_UNREACH_SRCFAIL;
931: goto bad;
932: }
1.1 cgd 933: ip_forward(m, 1);
934: return (1);
1.13 mycroft 935: }
936: return (0);
1.1 cgd 937: bad:
1.13 mycroft 938: ip->ip_len -= ip->ip_hl << 2; /* XXX icmp_error adds in hdr length */
939: icmp_error(m, type, code, 0, 0);
940: ipstat.ips_badoptions++;
1.1 cgd 941: return (1);
942: }
943:
944: /*
945: * Given address of next destination (final or next hop),
946: * return internet address info of interface to be used to get there.
947: */
948: struct in_ifaddr *
949: ip_rtaddr(dst)
950: struct in_addr dst;
951: {
952: register struct sockaddr_in *sin;
953:
1.19 mycroft 954: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 955:
1.35 mycroft 956: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 957: if (ipforward_rt.ro_rt) {
958: RTFREE(ipforward_rt.ro_rt);
959: ipforward_rt.ro_rt = 0;
960: }
961: sin->sin_family = AF_INET;
962: sin->sin_len = sizeof(*sin);
963: sin->sin_addr = dst;
964:
965: rtalloc(&ipforward_rt);
966: }
967: if (ipforward_rt.ro_rt == 0)
968: return ((struct in_ifaddr *)0);
1.19 mycroft 969: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 970: }
971:
972: /*
973: * Save incoming source route for use in replies,
974: * to be picked up later by ip_srcroute if the receiver is interested.
975: */
1.13 mycroft 976: void
1.1 cgd 977: save_rte(option, dst)
978: u_char *option;
979: struct in_addr dst;
980: {
981: unsigned olen;
982:
983: olen = option[IPOPT_OLEN];
984: #ifdef DIAGNOSTIC
985: if (ipprintfs)
1.39 christos 986: printf("save_rte: olen %d\n", olen);
1.1 cgd 987: #endif
988: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
989: return;
990: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
991: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
992: ip_srcrt.dst = dst;
993: }
994:
995: /*
996: * Retrieve incoming source route for use in replies,
997: * in the same form used by setsockopt.
998: * The first hop is placed before the options, will be removed later.
999: */
1000: struct mbuf *
1001: ip_srcroute()
1002: {
1003: register struct in_addr *p, *q;
1004: register struct mbuf *m;
1005:
1006: if (ip_nhops == 0)
1007: return ((struct mbuf *)0);
1008: m = m_get(M_DONTWAIT, MT_SOOPTS);
1009: if (m == 0)
1010: return ((struct mbuf *)0);
1011:
1.13 mycroft 1012: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1013:
1014: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1015: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1016: OPTSIZ;
1017: #ifdef DIAGNOSTIC
1018: if (ipprintfs)
1.39 christos 1019: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1020: #endif
1021:
1022: /*
1023: * First save first hop for return route
1024: */
1025: p = &ip_srcrt.route[ip_nhops - 1];
1026: *(mtod(m, struct in_addr *)) = *p--;
1027: #ifdef DIAGNOSTIC
1028: if (ipprintfs)
1.39 christos 1029: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1030: #endif
1031:
1032: /*
1033: * Copy option fields and padding (nop) to mbuf.
1034: */
1035: ip_srcrt.nop = IPOPT_NOP;
1036: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1037: bcopy((caddr_t)&ip_srcrt.nop,
1038: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1039: q = (struct in_addr *)(mtod(m, caddr_t) +
1040: sizeof(struct in_addr) + OPTSIZ);
1041: #undef OPTSIZ
1042: /*
1043: * Record return path as an IP source route,
1044: * reversing the path (pointers are now aligned).
1045: */
1046: while (p >= ip_srcrt.route) {
1047: #ifdef DIAGNOSTIC
1048: if (ipprintfs)
1.39 christos 1049: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1050: #endif
1051: *q++ = *p--;
1052: }
1053: /*
1054: * Last hop goes to final destination.
1055: */
1056: *q = ip_srcrt.dst;
1057: #ifdef DIAGNOSTIC
1058: if (ipprintfs)
1.39 christos 1059: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1060: #endif
1061: return (m);
1062: }
1063:
1064: /*
1065: * Strip out IP options, at higher
1066: * level protocol in the kernel.
1067: * Second argument is buffer to which options
1068: * will be moved, and return value is their length.
1069: * XXX should be deleted; last arg currently ignored.
1070: */
1.8 mycroft 1071: void
1.1 cgd 1072: ip_stripoptions(m, mopt)
1073: register struct mbuf *m;
1074: struct mbuf *mopt;
1075: {
1076: register int i;
1077: struct ip *ip = mtod(m, struct ip *);
1078: register caddr_t opts;
1079: int olen;
1080:
1081: olen = (ip->ip_hl<<2) - sizeof (struct ip);
1082: opts = (caddr_t)(ip + 1);
1083: i = m->m_len - (sizeof (struct ip) + olen);
1084: bcopy(opts + olen, opts, (unsigned)i);
1085: m->m_len -= olen;
1086: if (m->m_flags & M_PKTHDR)
1087: m->m_pkthdr.len -= olen;
1088: ip->ip_hl = sizeof(struct ip) >> 2;
1089: }
1090:
1.23 mycroft 1091: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1092: 0, 0, 0, 0,
1093: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1094: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1095: EMSGSIZE, EHOSTUNREACH, 0, 0,
1096: 0, 0, 0, 0,
1097: ENOPROTOOPT
1098: };
1099:
1100: /*
1101: * Forward a packet. If some error occurs return the sender
1102: * an icmp packet. Note we can't always generate a meaningful
1103: * icmp message because icmp doesn't have a large enough repertoire
1104: * of codes and types.
1105: *
1106: * If not forwarding, just drop the packet. This could be confusing
1107: * if ipforwarding was zero but some routing protocol was advancing
1108: * us as a gateway to somewhere. However, we must let the routing
1109: * protocol deal with that.
1110: *
1111: * The srcrt parameter indicates whether the packet is being forwarded
1112: * via a source route.
1113: */
1.13 mycroft 1114: void
1.1 cgd 1115: ip_forward(m, srcrt)
1116: struct mbuf *m;
1117: int srcrt;
1118: {
1119: register struct ip *ip = mtod(m, struct ip *);
1120: register struct sockaddr_in *sin;
1121: register struct rtentry *rt;
1.28 christos 1122: int error, type = 0, code = 0;
1.1 cgd 1123: struct mbuf *mcopy;
1.13 mycroft 1124: n_long dest;
1125: struct ifnet *destifp;
1.1 cgd 1126:
1.13 mycroft 1127: dest = 0;
1.1 cgd 1128: #ifdef DIAGNOSTIC
1129: if (ipprintfs)
1.39 christos 1130: printf("forward: src %x dst %x ttl %x\n",
1.35 mycroft 1131: ip->ip_src.s_addr, ip->ip_dst.s_addr, ip->ip_ttl);
1.1 cgd 1132: #endif
1133: if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
1134: ipstat.ips_cantforward++;
1135: m_freem(m);
1136: return;
1137: }
1138: HTONS(ip->ip_id);
1139: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1140: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1141: return;
1142: }
1143: ip->ip_ttl -= IPTTLDEC;
1144:
1.19 mycroft 1145: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1146: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1147: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1148: if (ipforward_rt.ro_rt) {
1149: RTFREE(ipforward_rt.ro_rt);
1150: ipforward_rt.ro_rt = 0;
1151: }
1152: sin->sin_family = AF_INET;
1.35 mycroft 1153: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1154: sin->sin_addr = ip->ip_dst;
1155:
1156: rtalloc(&ipforward_rt);
1157: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1158: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1159: return;
1160: }
1161: rt = ipforward_rt.ro_rt;
1162: }
1163:
1164: /*
1.34 mycroft 1165: * Save at most 68 bytes of the packet in case
1.1 cgd 1166: * we need to generate an ICMP message to the src.
1167: */
1.34 mycroft 1168: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1169:
1170: /*
1171: * If forwarding packet using same interface that it came in on,
1172: * perhaps should send a redirect to sender to shortcut a hop.
1173: * Only send redirect if source is sending directly to us,
1174: * and if packet was not source routed (or has any options).
1175: * Also, don't send redirect if forwarding using a default route
1176: * or a route modified by a redirect.
1177: */
1178: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1179: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1180: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1181: ipsendredirects && !srcrt) {
1.19 mycroft 1182: if (rt->rt_ifa &&
1183: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1184: ifatoia(rt->rt_ifa)->ia_subnet) {
1.1 cgd 1185: if (rt->rt_flags & RTF_GATEWAY)
1.13 mycroft 1186: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1.1 cgd 1187: else
1.13 mycroft 1188: dest = ip->ip_dst.s_addr;
1189: /* Router requirements says to only send host redirects */
1.1 cgd 1190: type = ICMP_REDIRECT;
1.13 mycroft 1191: code = ICMP_REDIRECT_HOST;
1.1 cgd 1192: #ifdef DIAGNOSTIC
1193: if (ipprintfs)
1.39 christos 1194: printf("redirect (%d) to %x\n", code, (u_int32_t)dest);
1.1 cgd 1195: #endif
1196: }
1197: }
1198:
1.27 thorpej 1199: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1200: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1201: if (error)
1202: ipstat.ips_cantforward++;
1203: else {
1204: ipstat.ips_forward++;
1205: if (type)
1206: ipstat.ips_redirectsent++;
1207: else {
1.63 matt 1208: if (mcopy) {
1209: #ifdef GATEWAY
1.64 thorpej 1210: if (mcopy->m_flags & M_CANFASTFWD)
1211: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1212: #endif
1.1 cgd 1213: m_freem(mcopy);
1.63 matt 1214: }
1.1 cgd 1215: return;
1216: }
1217: }
1218: if (mcopy == NULL)
1219: return;
1.13 mycroft 1220: destifp = NULL;
1221:
1.1 cgd 1222: switch (error) {
1223:
1224: case 0: /* forwarded, but need redirect */
1225: /* type, code set above */
1226: break;
1227:
1228: case ENETUNREACH: /* shouldn't happen, checked above */
1229: case EHOSTUNREACH:
1230: case ENETDOWN:
1231: case EHOSTDOWN:
1232: default:
1233: type = ICMP_UNREACH;
1234: code = ICMP_UNREACH_HOST;
1235: break;
1236:
1237: case EMSGSIZE:
1238: type = ICMP_UNREACH;
1239: code = ICMP_UNREACH_NEEDFRAG;
1.13 mycroft 1240: if (ipforward_rt.ro_rt)
1241: destifp = ipforward_rt.ro_rt->rt_ifp;
1.1 cgd 1242: ipstat.ips_cantfrag++;
1243: break;
1244:
1245: case ENOBUFS:
1246: type = ICMP_SOURCEQUENCH;
1247: code = 0;
1248: break;
1249: }
1.13 mycroft 1250: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1251: }
1252:
1253: void
1254: ip_savecontrol(inp, mp, ip, m)
1255: register struct inpcb *inp;
1256: register struct mbuf **mp;
1257: register struct ip *ip;
1258: register struct mbuf *m;
1259: {
1260:
1261: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1262: struct timeval tv;
1263:
1264: microtime(&tv);
1265: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1266: SCM_TIMESTAMP, SOL_SOCKET);
1267: if (*mp)
1268: mp = &(*mp)->m_next;
1269: }
1270: if (inp->inp_flags & INP_RECVDSTADDR) {
1271: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1272: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1273: if (*mp)
1274: mp = &(*mp)->m_next;
1275: }
1276: #ifdef notyet
1277: /*
1278: * XXX
1279: * Moving these out of udp_input() made them even more broken
1280: * than they already were.
1281: * - fenner@parc.xerox.com
1282: */
1283: /* options were tossed already */
1284: if (inp->inp_flags & INP_RECVOPTS) {
1285: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1286: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1287: if (*mp)
1288: mp = &(*mp)->m_next;
1289: }
1290: /* ip_srcroute doesn't do what we want here, need to fix */
1291: if (inp->inp_flags & INP_RECVRETOPTS) {
1292: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1293: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1294: if (*mp)
1295: mp = &(*mp)->m_next;
1296: }
1297: #endif
1298: if (inp->inp_flags & INP_RECVIF) {
1299: struct sockaddr_dl sdl;
1300:
1301: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1302: sdl.sdl_family = AF_LINK;
1303: sdl.sdl_index = m->m_pkthdr.rcvif ?
1304: m->m_pkthdr.rcvif->if_index : 0;
1305: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1306: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1307: IP_RECVIF, IPPROTO_IP);
1308: if (*mp)
1309: mp = &(*mp)->m_next;
1310: }
1.13 mycroft 1311: }
1312:
1313: int
1314: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1315: int *name;
1316: u_int namelen;
1317: void *oldp;
1318: size_t *oldlenp;
1319: void *newp;
1320: size_t newlen;
1321: {
1.52 thorpej 1322: extern int subnetsarelocal;
1323:
1.54 lukem 1324: int error, old;
1325:
1.13 mycroft 1326: /* All sysctl names at this level are terminal. */
1327: if (namelen != 1)
1328: return (ENOTDIR);
1329:
1330: switch (name[0]) {
1331: case IPCTL_FORWARDING:
1332: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1333: case IPCTL_SENDREDIRECTS:
1334: return (sysctl_int(oldp, oldlenp, newp, newlen,
1335: &ipsendredirects));
1336: case IPCTL_DEFTTL:
1337: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1338: #ifdef notyet
1339: case IPCTL_DEFMTU:
1340: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1341: #endif
1.26 thorpej 1342: case IPCTL_FORWSRCRT:
1.47 cjs 1343: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1344: if (securelevel > 0)
1.46 cjs 1345: return (sysctl_rdint(oldp, oldlenp, newp,
1346: ip_forwsrcrt));
1347: else
1348: return (sysctl_int(oldp, oldlenp, newp, newlen,
1349: &ip_forwsrcrt));
1.27 thorpej 1350: case IPCTL_DIRECTEDBCAST:
1351: return (sysctl_int(oldp, oldlenp, newp, newlen,
1352: &ip_directedbcast));
1.47 cjs 1353: case IPCTL_ALLOWSRCRT:
1354: return (sysctl_int(oldp, oldlenp, newp, newlen,
1355: &ip_allowsrcrt));
1.52 thorpej 1356: case IPCTL_SUBNETSARELOCAL:
1357: return (sysctl_int(oldp, oldlenp, newp, newlen,
1358: &subnetsarelocal));
1.53 kml 1359: case IPCTL_MTUDISC:
1.60 kml 1360: error = sysctl_int(oldp, oldlenp, newp, newlen,
1361: &ip_mtudisc);
1362: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1363: ip_mtudisc_timeout_q =
1364: rt_timer_queue_create(ip_mtudisc_timeout);
1365: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1366: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1367: ip_mtudisc_timeout_q = NULL;
1368: }
1369: return error;
1.54 lukem 1370: case IPCTL_ANONPORTMIN:
1371: old = anonportmin;
1372: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1373: if (anonportmin >= anonportmax || anonportmin > 65535
1374: #ifndef IPNOPRIVPORTS
1375: || anonportmin < IPPORT_RESERVED
1376: #endif
1377: ) {
1378: anonportmin = old;
1379: return (EINVAL);
1380: }
1381: return (error);
1382: case IPCTL_ANONPORTMAX:
1383: old = anonportmax;
1384: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1385: if (anonportmin >= anonportmax || anonportmax > 65535
1386: #ifndef IPNOPRIVPORTS
1387: || anonportmax < IPPORT_RESERVED
1388: #endif
1389: ) {
1390: anonportmax = old;
1391: return (EINVAL);
1392: }
1.60 kml 1393: return (error);
1394: case IPCTL_MTUDISCTIMEOUT:
1395: error = sysctl_int(oldp, oldlenp, newp, newlen,
1396: &ip_mtudisc_timeout);
1397: if (ip_mtudisc_timeout_q != NULL)
1398: rt_timer_queue_change(ip_mtudisc_timeout_q,
1399: ip_mtudisc_timeout);
1.54 lukem 1400: return (error);
1.65 matt 1401: #ifdef GATEWAY
1402: case IPCTL_MAXFLOWS:
1403: error = sysctl_int(oldp, oldlenp, newp, newlen,
1404: &ip_maxflows);
1405: ipflow_reap(0);
1406: return (error);
1407: #endif
1.13 mycroft 1408: default:
1409: return (EOPNOTSUPP);
1410: }
1411: /* NOTREACHED */
1.1 cgd 1412: }
CVSweb <webmaster@jp.NetBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to ip_input.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [cvs.NetBSD.org] / src / sys / netinet