Annotation of src/sys/netinet/ip_input.c, Revision 1.63
1.63 ! matt 1: /* $NetBSD: ip_input.c,v 1.62 1998/04/29 20:45:30 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:
1.36 mrg 312: #ifdef PFIL_HOOKS
1.33 mrg 313: /*
314: * Run through list of hooks for input packets.
315: */
316: m0 = m;
1.59 mrg 317: for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33 mrg 318: if (pfh->pfil_func) {
1.43 mrg 319: rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
320: if (rv)
1.40 veego 321: goto next;
1.49 christos 322: ip = mtod(m = m0, struct ip *);
1.33 mrg 323: }
1.36 mrg 324: #endif /* PFIL_HOOKS */
1.33 mrg 325:
1.1 cgd 326: /*
327: * Process options and, if not destined for us,
328: * ship it on. ip_dooptions returns 1 when an
329: * error was detected (causing an icmp message
330: * to be sent and the original packet to be freed).
331: */
332: ip_nhops = 0; /* for source routed packets */
333: if (hlen > sizeof (struct ip) && ip_dooptions(m))
334: goto next;
335:
336: /*
337: * Check our list of addresses, to see if the packet is for us.
338: */
1.57 tls 339: INADDR_TO_IA(ip->ip_dst, ia);
340: if (ia != NULL) goto ours;
341: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
342: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
343: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
344: if (ifa->ifa_addr->sa_family != AF_INET) continue;
345: ia = ifatoia(ifa);
1.35 mycroft 346: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
347: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 348: /*
349: * Look for all-0's host part (old broadcast addr),
350: * either for subnet or net.
351: */
352: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 353: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 354: goto ours;
1.57 tls 355: /*
356: * An interface with IP address zero accepts
357: * all packets that arrive on that interface.
358: */
359: if (in_nullhost(ia->ia_addr.sin_addr))
360: goto ours;
1.1 cgd 361: }
362: }
1.18 mycroft 363: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 364: struct in_multi *inm;
365: #ifdef MROUTING
366: extern struct socket *ip_mrouter;
1.10 brezak 367:
368: if (m->m_flags & M_EXT) {
369: if ((m = m_pullup(m, hlen)) == 0) {
370: ipstat.ips_toosmall++;
371: goto next;
372: }
373: ip = mtod(m, struct ip *);
374: }
1.4 hpeyerl 375:
376: if (ip_mrouter) {
377: /*
378: * If we are acting as a multicast router, all
379: * incoming multicast packets are passed to the
380: * kernel-level multicast forwarding function.
381: * The packet is returned (relatively) intact; if
382: * ip_mforward() returns a non-zero value, the packet
383: * must be discarded, else it may be accepted below.
384: *
385: * (The IP ident field is put in the same byte order
386: * as expected when ip_mforward() is called from
387: * ip_output().)
388: */
389: ip->ip_id = htons(ip->ip_id);
1.13 mycroft 390: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
391: ipstat.ips_cantforward++;
1.4 hpeyerl 392: m_freem(m);
393: goto next;
394: }
395: ip->ip_id = ntohs(ip->ip_id);
396:
397: /*
398: * The process-level routing demon needs to receive
399: * all multicast IGMP packets, whether or not this
400: * host belongs to their destination groups.
401: */
402: if (ip->ip_p == IPPROTO_IGMP)
403: goto ours;
1.13 mycroft 404: ipstat.ips_forward++;
1.4 hpeyerl 405: }
406: #endif
407: /*
408: * See if we belong to the destination multicast group on the
409: * arrival interface.
410: */
411: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
412: if (inm == NULL) {
1.13 mycroft 413: ipstat.ips_cantforward++;
1.4 hpeyerl 414: m_freem(m);
415: goto next;
416: }
417: goto ours;
418: }
1.19 mycroft 419: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 420: in_nullhost(ip->ip_dst))
1.1 cgd 421: goto ours;
422:
423: /*
424: * Not for us; forward if possible and desirable.
425: */
426: if (ipforwarding == 0) {
427: ipstat.ips_cantforward++;
428: m_freem(m);
429: } else
430: ip_forward(m, 0);
431: goto next;
432:
433: ours:
434: /*
435: * If offset or IP_MF are set, must reassemble.
436: * Otherwise, nothing need be done.
437: * (We could look in the reassembly queue to see
438: * if the packet was previously fragmented,
439: * but it's not worth the time; just let them time out.)
440: */
1.37 perry 441: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 442: /*
443: * Look for queue of fragments
444: * of this datagram.
445: */
1.25 cgd 446: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 447: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 448: in_hosteq(ip->ip_src, fp->ipq_src) &&
449: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 450: ip->ip_p == fp->ipq_p)
451: goto found;
452: fp = 0;
453: found:
454:
455: /*
456: * Adjust ip_len to not reflect header,
1.25 cgd 457: * set ipqe_mff if more fragments are expected,
1.1 cgd 458: * convert offset of this to bytes.
459: */
460: ip->ip_len -= hlen;
1.25 cgd 461: mff = (ip->ip_off & IP_MF) != 0;
462: if (mff) {
1.16 cgd 463: /*
464: * Make sure that fragments have a data length
465: * that's a non-zero multiple of 8 bytes.
466: */
1.17 cgd 467: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 468: ipstat.ips_badfrags++;
469: goto bad;
470: }
471: }
1.1 cgd 472: ip->ip_off <<= 3;
473:
474: /*
475: * If datagram marked as having more fragments
476: * or if this is not the first fragment,
477: * attempt reassembly; if it succeeds, proceed.
478: */
1.25 cgd 479: if (mff || ip->ip_off) {
1.1 cgd 480: ipstat.ips_fragments++;
1.25 cgd 481: MALLOC(ipqe, struct ipqent *, sizeof (struct ipqent),
482: M_IPQ, M_NOWAIT);
483: if (ipqe == NULL) {
484: ipstat.ips_rcvmemdrop++;
485: goto bad;
486: }
487: ipqe->ipqe_mff = mff;
1.50 thorpej 488: ipqe->ipqe_m = m;
1.25 cgd 489: ipqe->ipqe_ip = ip;
1.50 thorpej 490: m = ip_reass(ipqe, fp);
491: if (m == 0)
1.1 cgd 492: goto next;
1.13 mycroft 493: ipstat.ips_reassembled++;
1.50 thorpej 494: ip = mtod(m, struct ip *);
1.1 cgd 495: } else
496: if (fp)
497: ip_freef(fp);
498: } else
499: ip->ip_len -= hlen;
500:
501: /*
502: * Switch out to protocol's input routine.
503: */
504: ipstat.ips_delivered++;
505: (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
506: goto next;
507: bad:
508: m_freem(m);
509: goto next;
510: }
511:
512: /*
513: * Take incoming datagram fragment and try to
514: * reassemble it into whole datagram. If a chain for
515: * reassembly of this datagram already exists, then it
516: * is given as fp; otherwise have to make a chain.
517: */
1.50 thorpej 518: struct mbuf *
1.25 cgd 519: ip_reass(ipqe, fp)
520: register struct ipqent *ipqe;
1.1 cgd 521: register struct ipq *fp;
522: {
1.50 thorpej 523: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 524: register struct ipqent *nq, *p, *q;
525: struct ip *ip;
1.1 cgd 526: struct mbuf *t;
1.25 cgd 527: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 528: int i, next;
529:
530: /*
531: * Presence of header sizes in mbufs
532: * would confuse code below.
533: */
534: m->m_data += hlen;
535: m->m_len -= hlen;
536:
537: /*
538: * If first fragment to arrive, create a reassembly queue.
539: */
540: if (fp == 0) {
1.50 thorpej 541: MALLOC(fp, struct ipq *, sizeof (struct ipq),
542: M_FTABLE, M_NOWAIT);
543: if (fp == NULL)
1.1 cgd 544: goto dropfrag;
1.25 cgd 545: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 546: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 547: fp->ipq_p = ipqe->ipqe_ip->ip_p;
548: fp->ipq_id = ipqe->ipqe_ip->ip_id;
549: LIST_INIT(&fp->ipq_fragq);
550: fp->ipq_src = ipqe->ipqe_ip->ip_src;
551: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
552: p = NULL;
1.1 cgd 553: goto insert;
554: }
555:
556: /*
557: * Find a segment which begins after this one does.
558: */
1.25 cgd 559: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
560: p = q, q = q->ipqe_q.le_next)
561: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 562: break;
563:
564: /*
565: * If there is a preceding segment, it may provide some of
566: * our data already. If so, drop the data from the incoming
567: * segment. If it provides all of our data, drop us.
568: */
1.25 cgd 569: if (p != NULL) {
570: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
571: ipqe->ipqe_ip->ip_off;
1.1 cgd 572: if (i > 0) {
1.25 cgd 573: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 574: goto dropfrag;
1.50 thorpej 575: m_adj(ipqe->ipqe_m, i);
1.25 cgd 576: ipqe->ipqe_ip->ip_off += i;
577: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 578: }
579: }
580:
581: /*
582: * While we overlap succeeding segments trim them or,
583: * if they are completely covered, dequeue them.
584: */
1.25 cgd 585: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
586: q->ipqe_ip->ip_off; q = nq) {
587: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
588: q->ipqe_ip->ip_off;
589: if (i < q->ipqe_ip->ip_len) {
590: q->ipqe_ip->ip_len -= i;
591: q->ipqe_ip->ip_off += i;
1.50 thorpej 592: m_adj(q->ipqe_m, i);
1.1 cgd 593: break;
594: }
1.25 cgd 595: nq = q->ipqe_q.le_next;
1.50 thorpej 596: m_freem(q->ipqe_m);
1.25 cgd 597: LIST_REMOVE(q, ipqe_q);
598: FREE(q, M_IPQ);
1.1 cgd 599: }
600:
601: insert:
602: /*
603: * Stick new segment in its place;
604: * check for complete reassembly.
605: */
1.25 cgd 606: if (p == NULL) {
607: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
608: } else {
609: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
610: }
1.1 cgd 611: next = 0;
1.25 cgd 612: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
613: p = q, q = q->ipqe_q.le_next) {
614: if (q->ipqe_ip->ip_off != next)
1.1 cgd 615: return (0);
1.25 cgd 616: next += q->ipqe_ip->ip_len;
1.1 cgd 617: }
1.25 cgd 618: if (p->ipqe_mff)
1.1 cgd 619: return (0);
620:
621: /*
1.41 thorpej 622: * Reassembly is complete. Check for a bogus message size and
623: * concatenate fragments.
1.1 cgd 624: */
1.25 cgd 625: q = fp->ipq_fragq.lh_first;
626: ip = q->ipqe_ip;
1.41 thorpej 627: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
628: ipstat.ips_toolong++;
629: ip_freef(fp);
630: return (0);
631: }
1.50 thorpej 632: m = q->ipqe_m;
1.1 cgd 633: t = m->m_next;
634: m->m_next = 0;
635: m_cat(m, t);
1.25 cgd 636: nq = q->ipqe_q.le_next;
637: FREE(q, M_IPQ);
638: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 639: t = q->ipqe_m;
1.25 cgd 640: nq = q->ipqe_q.le_next;
641: FREE(q, M_IPQ);
1.1 cgd 642: m_cat(m, t);
643: }
644:
645: /*
646: * Create header for new ip packet by
647: * modifying header of first packet;
648: * dequeue and discard fragment reassembly header.
649: * Make header visible.
650: */
651: ip->ip_len = next;
1.25 cgd 652: ip->ip_src = fp->ipq_src;
653: ip->ip_dst = fp->ipq_dst;
654: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 655: FREE(fp, M_FTABLE);
1.1 cgd 656: m->m_len += (ip->ip_hl << 2);
657: m->m_data -= (ip->ip_hl << 2);
658: /* some debugging cruft by sklower, below, will go away soon */
659: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
660: register int plen = 0;
1.50 thorpej 661: for (t = m; t; t = t->m_next)
662: plen += t->m_len;
663: m->m_pkthdr.len = plen;
1.1 cgd 664: }
1.50 thorpej 665: return (m);
1.1 cgd 666:
667: dropfrag:
668: ipstat.ips_fragdropped++;
669: m_freem(m);
1.25 cgd 670: FREE(ipqe, M_IPQ);
1.1 cgd 671: return (0);
672: }
673:
674: /*
675: * Free a fragment reassembly header and all
676: * associated datagrams.
677: */
1.8 mycroft 678: void
1.1 cgd 679: ip_freef(fp)
680: struct ipq *fp;
681: {
1.25 cgd 682: register struct ipqent *q, *p;
1.1 cgd 683:
1.25 cgd 684: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
685: p = q->ipqe_q.le_next;
1.50 thorpej 686: m_freem(q->ipqe_m);
1.25 cgd 687: LIST_REMOVE(q, ipqe_q);
688: FREE(q, M_IPQ);
1.1 cgd 689: }
1.25 cgd 690: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 691: FREE(fp, M_FTABLE);
1.1 cgd 692: }
693:
694: /*
695: * IP timer processing;
696: * if a timer expires on a reassembly
697: * queue, discard it.
698: */
1.8 mycroft 699: void
1.1 cgd 700: ip_slowtimo()
701: {
1.25 cgd 702: register struct ipq *fp, *nfp;
1.24 mycroft 703: int s = splsoftnet();
1.1 cgd 704:
1.25 cgd 705: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
706: nfp = fp->ipq_q.le_next;
707: if (--fp->ipq_ttl == 0) {
1.1 cgd 708: ipstat.ips_fragtimeout++;
1.25 cgd 709: ip_freef(fp);
1.1 cgd 710: }
711: }
1.63 ! matt 712: #ifdef GATEWAY
! 713: ipflow_slowtimo();
! 714: #endif
1.1 cgd 715: splx(s);
716: }
717:
718: /*
719: * Drain off all datagram fragments.
720: */
1.8 mycroft 721: void
1.1 cgd 722: ip_drain()
723: {
724:
1.25 cgd 725: while (ipq.lh_first != NULL) {
1.1 cgd 726: ipstat.ips_fragdropped++;
1.25 cgd 727: ip_freef(ipq.lh_first);
1.1 cgd 728: }
729: }
730:
731: /*
732: * Do option processing on a datagram,
733: * possibly discarding it if bad options are encountered,
734: * or forwarding it if source-routed.
735: * Returns 1 if packet has been forwarded/freed,
736: * 0 if the packet should be processed further.
737: */
1.8 mycroft 738: int
1.1 cgd 739: ip_dooptions(m)
740: struct mbuf *m;
741: {
742: register struct ip *ip = mtod(m, struct ip *);
743: register u_char *cp;
744: register struct ip_timestamp *ipt;
745: register struct in_ifaddr *ia;
746: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13 mycroft 747: struct in_addr *sin, dst;
1.1 cgd 748: n_time ntime;
749:
1.13 mycroft 750: dst = ip->ip_dst;
1.1 cgd 751: cp = (u_char *)(ip + 1);
752: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
753: for (; cnt > 0; cnt -= optlen, cp += optlen) {
754: opt = cp[IPOPT_OPTVAL];
755: if (opt == IPOPT_EOL)
756: break;
757: if (opt == IPOPT_NOP)
758: optlen = 1;
759: else {
760: optlen = cp[IPOPT_OLEN];
761: if (optlen <= 0 || optlen > cnt) {
762: code = &cp[IPOPT_OLEN] - (u_char *)ip;
763: goto bad;
764: }
765: }
766: switch (opt) {
767:
768: default:
769: break;
770:
771: /*
772: * Source routing with record.
773: * Find interface with current destination address.
774: * If none on this machine then drop if strictly routed,
775: * or do nothing if loosely routed.
776: * Record interface address and bring up next address
777: * component. If strictly routed make sure next
778: * address is on directly accessible net.
779: */
780: case IPOPT_LSRR:
781: case IPOPT_SSRR:
1.47 cjs 782: if (ip_allowsrcrt == 0) {
783: type = ICMP_UNREACH;
784: code = ICMP_UNREACH_NET_PROHIB;
785: goto bad;
786: }
1.1 cgd 787: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
788: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
789: goto bad;
790: }
791: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 792: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 793: if (ia == 0) {
794: if (opt == IPOPT_SSRR) {
795: type = ICMP_UNREACH;
796: code = ICMP_UNREACH_SRCFAIL;
797: goto bad;
798: }
799: /*
800: * Loose routing, and not at next destination
801: * yet; nothing to do except forward.
802: */
803: break;
804: }
805: off--; /* 0 origin */
806: if (off > optlen - sizeof(struct in_addr)) {
807: /*
808: * End of source route. Should be for us.
809: */
810: save_rte(cp, ip->ip_src);
811: break;
812: }
813: /*
814: * locate outgoing interface
815: */
816: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
817: sizeof(ipaddr.sin_addr));
818: if (opt == IPOPT_SSRR) {
819: #define INA struct in_ifaddr *
820: #define SA struct sockaddr *
1.29 mrg 821: ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1 cgd 822: } else
823: ia = ip_rtaddr(ipaddr.sin_addr);
824: if (ia == 0) {
825: type = ICMP_UNREACH;
826: code = ICMP_UNREACH_SRCFAIL;
827: goto bad;
828: }
829: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 830: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 831: (caddr_t)(cp + off), sizeof(struct in_addr));
832: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 833: /*
834: * Let ip_intr's mcast routing check handle mcast pkts
835: */
1.18 mycroft 836: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 837: break;
838:
839: case IPOPT_RR:
840: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
841: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
842: goto bad;
843: }
844: /*
845: * If no space remains, ignore.
846: */
847: off--; /* 0 origin */
848: if (off > optlen - sizeof(struct in_addr))
849: break;
850: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
851: sizeof(ipaddr.sin_addr));
852: /*
853: * locate outgoing interface; if we're the destination,
854: * use the incoming interface (should be same).
855: */
856: if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
857: (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
858: type = ICMP_UNREACH;
859: code = ICMP_UNREACH_HOST;
860: goto bad;
861: }
1.20 mycroft 862: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 863: (caddr_t)(cp + off), sizeof(struct in_addr));
864: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
865: break;
866:
867: case IPOPT_TS:
868: code = cp - (u_char *)ip;
869: ipt = (struct ip_timestamp *)cp;
870: if (ipt->ipt_len < 5)
871: goto bad;
1.15 cgd 872: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 873: if (++ipt->ipt_oflw == 0)
874: goto bad;
875: break;
876: }
877: sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
878: switch (ipt->ipt_flg) {
879:
880: case IPOPT_TS_TSONLY:
881: break;
882:
883: case IPOPT_TS_TSANDADDR:
884: if (ipt->ipt_ptr + sizeof(n_time) +
885: sizeof(struct in_addr) > ipt->ipt_len)
886: goto bad;
1.13 mycroft 887: ipaddr.sin_addr = dst;
888: ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
889: m->m_pkthdr.rcvif);
890: if (ia == 0)
891: continue;
1.20 mycroft 892: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 893: (caddr_t)sin, sizeof(struct in_addr));
894: ipt->ipt_ptr += sizeof(struct in_addr);
895: break;
896:
897: case IPOPT_TS_PRESPEC:
898: if (ipt->ipt_ptr + sizeof(n_time) +
899: sizeof(struct in_addr) > ipt->ipt_len)
900: goto bad;
901: bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
902: sizeof(struct in_addr));
903: if (ifa_ifwithaddr((SA)&ipaddr) == 0)
904: continue;
905: ipt->ipt_ptr += sizeof(struct in_addr);
906: break;
907:
908: default:
909: goto bad;
910: }
911: ntime = iptime();
912: bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
913: sizeof(n_time));
914: ipt->ipt_ptr += sizeof(n_time);
915: }
916: }
917: if (forward) {
1.26 thorpej 918: if (ip_forwsrcrt == 0) {
919: type = ICMP_UNREACH;
920: code = ICMP_UNREACH_SRCFAIL;
921: goto bad;
922: }
1.1 cgd 923: ip_forward(m, 1);
924: return (1);
1.13 mycroft 925: }
926: return (0);
1.1 cgd 927: bad:
1.13 mycroft 928: ip->ip_len -= ip->ip_hl << 2; /* XXX icmp_error adds in hdr length */
929: icmp_error(m, type, code, 0, 0);
930: ipstat.ips_badoptions++;
1.1 cgd 931: return (1);
932: }
933:
934: /*
935: * Given address of next destination (final or next hop),
936: * return internet address info of interface to be used to get there.
937: */
938: struct in_ifaddr *
939: ip_rtaddr(dst)
940: struct in_addr dst;
941: {
942: register struct sockaddr_in *sin;
943:
1.19 mycroft 944: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 945:
1.35 mycroft 946: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 947: if (ipforward_rt.ro_rt) {
948: RTFREE(ipforward_rt.ro_rt);
949: ipforward_rt.ro_rt = 0;
950: }
951: sin->sin_family = AF_INET;
952: sin->sin_len = sizeof(*sin);
953: sin->sin_addr = dst;
954:
955: rtalloc(&ipforward_rt);
956: }
957: if (ipforward_rt.ro_rt == 0)
958: return ((struct in_ifaddr *)0);
1.19 mycroft 959: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 960: }
961:
962: /*
963: * Save incoming source route for use in replies,
964: * to be picked up later by ip_srcroute if the receiver is interested.
965: */
1.13 mycroft 966: void
1.1 cgd 967: save_rte(option, dst)
968: u_char *option;
969: struct in_addr dst;
970: {
971: unsigned olen;
972:
973: olen = option[IPOPT_OLEN];
974: #ifdef DIAGNOSTIC
975: if (ipprintfs)
1.39 christos 976: printf("save_rte: olen %d\n", olen);
1.1 cgd 977: #endif
978: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
979: return;
980: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
981: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
982: ip_srcrt.dst = dst;
983: }
984:
985: /*
986: * Retrieve incoming source route for use in replies,
987: * in the same form used by setsockopt.
988: * The first hop is placed before the options, will be removed later.
989: */
990: struct mbuf *
991: ip_srcroute()
992: {
993: register struct in_addr *p, *q;
994: register struct mbuf *m;
995:
996: if (ip_nhops == 0)
997: return ((struct mbuf *)0);
998: m = m_get(M_DONTWAIT, MT_SOOPTS);
999: if (m == 0)
1000: return ((struct mbuf *)0);
1001:
1.13 mycroft 1002: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1003:
1004: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1005: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1006: OPTSIZ;
1007: #ifdef DIAGNOSTIC
1008: if (ipprintfs)
1.39 christos 1009: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1010: #endif
1011:
1012: /*
1013: * First save first hop for return route
1014: */
1015: p = &ip_srcrt.route[ip_nhops - 1];
1016: *(mtod(m, struct in_addr *)) = *p--;
1017: #ifdef DIAGNOSTIC
1018: if (ipprintfs)
1.39 christos 1019: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1020: #endif
1021:
1022: /*
1023: * Copy option fields and padding (nop) to mbuf.
1024: */
1025: ip_srcrt.nop = IPOPT_NOP;
1026: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1027: bcopy((caddr_t)&ip_srcrt.nop,
1028: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1029: q = (struct in_addr *)(mtod(m, caddr_t) +
1030: sizeof(struct in_addr) + OPTSIZ);
1031: #undef OPTSIZ
1032: /*
1033: * Record return path as an IP source route,
1034: * reversing the path (pointers are now aligned).
1035: */
1036: while (p >= ip_srcrt.route) {
1037: #ifdef DIAGNOSTIC
1038: if (ipprintfs)
1.39 christos 1039: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1040: #endif
1041: *q++ = *p--;
1042: }
1043: /*
1044: * Last hop goes to final destination.
1045: */
1046: *q = ip_srcrt.dst;
1047: #ifdef DIAGNOSTIC
1048: if (ipprintfs)
1.39 christos 1049: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1050: #endif
1051: return (m);
1052: }
1053:
1054: /*
1055: * Strip out IP options, at higher
1056: * level protocol in the kernel.
1057: * Second argument is buffer to which options
1058: * will be moved, and return value is their length.
1059: * XXX should be deleted; last arg currently ignored.
1060: */
1.8 mycroft 1061: void
1.1 cgd 1062: ip_stripoptions(m, mopt)
1063: register struct mbuf *m;
1064: struct mbuf *mopt;
1065: {
1066: register int i;
1067: struct ip *ip = mtod(m, struct ip *);
1068: register caddr_t opts;
1069: int olen;
1070:
1071: olen = (ip->ip_hl<<2) - sizeof (struct ip);
1072: opts = (caddr_t)(ip + 1);
1073: i = m->m_len - (sizeof (struct ip) + olen);
1074: bcopy(opts + olen, opts, (unsigned)i);
1075: m->m_len -= olen;
1076: if (m->m_flags & M_PKTHDR)
1077: m->m_pkthdr.len -= olen;
1078: ip->ip_hl = sizeof(struct ip) >> 2;
1079: }
1080:
1.23 mycroft 1081: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1082: 0, 0, 0, 0,
1083: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1084: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1085: EMSGSIZE, EHOSTUNREACH, 0, 0,
1086: 0, 0, 0, 0,
1087: ENOPROTOOPT
1088: };
1089:
1090: /*
1091: * Forward a packet. If some error occurs return the sender
1092: * an icmp packet. Note we can't always generate a meaningful
1093: * icmp message because icmp doesn't have a large enough repertoire
1094: * of codes and types.
1095: *
1096: * If not forwarding, just drop the packet. This could be confusing
1097: * if ipforwarding was zero but some routing protocol was advancing
1098: * us as a gateway to somewhere. However, we must let the routing
1099: * protocol deal with that.
1100: *
1101: * The srcrt parameter indicates whether the packet is being forwarded
1102: * via a source route.
1103: */
1.13 mycroft 1104: void
1.1 cgd 1105: ip_forward(m, srcrt)
1106: struct mbuf *m;
1107: int srcrt;
1108: {
1109: register struct ip *ip = mtod(m, struct ip *);
1110: register struct sockaddr_in *sin;
1111: register struct rtentry *rt;
1.28 christos 1112: int error, type = 0, code = 0;
1.1 cgd 1113: struct mbuf *mcopy;
1.13 mycroft 1114: n_long dest;
1115: struct ifnet *destifp;
1.1 cgd 1116:
1.13 mycroft 1117: dest = 0;
1.1 cgd 1118: #ifdef DIAGNOSTIC
1119: if (ipprintfs)
1.39 christos 1120: printf("forward: src %x dst %x ttl %x\n",
1.35 mycroft 1121: ip->ip_src.s_addr, ip->ip_dst.s_addr, ip->ip_ttl);
1.1 cgd 1122: #endif
1123: if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
1124: ipstat.ips_cantforward++;
1125: m_freem(m);
1126: return;
1127: }
1128: HTONS(ip->ip_id);
1129: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1130: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1131: return;
1132: }
1133: ip->ip_ttl -= IPTTLDEC;
1134:
1.19 mycroft 1135: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1136: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1137: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1138: if (ipforward_rt.ro_rt) {
1139: RTFREE(ipforward_rt.ro_rt);
1140: ipforward_rt.ro_rt = 0;
1141: }
1142: sin->sin_family = AF_INET;
1.35 mycroft 1143: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1144: sin->sin_addr = ip->ip_dst;
1145:
1146: rtalloc(&ipforward_rt);
1147: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1148: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1149: return;
1150: }
1151: rt = ipforward_rt.ro_rt;
1152: }
1153:
1154: /*
1.34 mycroft 1155: * Save at most 68 bytes of the packet in case
1.1 cgd 1156: * we need to generate an ICMP message to the src.
1157: */
1.34 mycroft 1158: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1159:
1160: /*
1161: * If forwarding packet using same interface that it came in on,
1162: * perhaps should send a redirect to sender to shortcut a hop.
1163: * Only send redirect if source is sending directly to us,
1164: * and if packet was not source routed (or has any options).
1165: * Also, don't send redirect if forwarding using a default route
1166: * or a route modified by a redirect.
1167: */
1168: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1169: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1170: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1171: ipsendredirects && !srcrt) {
1.19 mycroft 1172: if (rt->rt_ifa &&
1173: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1174: ifatoia(rt->rt_ifa)->ia_subnet) {
1.1 cgd 1175: if (rt->rt_flags & RTF_GATEWAY)
1.13 mycroft 1176: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1.1 cgd 1177: else
1.13 mycroft 1178: dest = ip->ip_dst.s_addr;
1179: /* Router requirements says to only send host redirects */
1.1 cgd 1180: type = ICMP_REDIRECT;
1.13 mycroft 1181: code = ICMP_REDIRECT_HOST;
1.1 cgd 1182: #ifdef DIAGNOSTIC
1183: if (ipprintfs)
1.39 christos 1184: printf("redirect (%d) to %x\n", code, (u_int32_t)dest);
1.1 cgd 1185: #endif
1186: }
1187: }
1188:
1.27 thorpej 1189: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1190: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1191: if (error)
1192: ipstat.ips_cantforward++;
1193: else {
1194: ipstat.ips_forward++;
1195: if (type)
1196: ipstat.ips_redirectsent++;
1197: else {
1.63 ! matt 1198: if (mcopy) {
! 1199: #ifdef GATEWAY
! 1200: ipflow_create(&ipforward_rt, mcopy);
! 1201: #endif
1.1 cgd 1202: m_freem(mcopy);
1.63 ! matt 1203: }
1.1 cgd 1204: return;
1205: }
1206: }
1207: if (mcopy == NULL)
1208: return;
1.13 mycroft 1209: destifp = NULL;
1210:
1.1 cgd 1211: switch (error) {
1212:
1213: case 0: /* forwarded, but need redirect */
1214: /* type, code set above */
1215: break;
1216:
1217: case ENETUNREACH: /* shouldn't happen, checked above */
1218: case EHOSTUNREACH:
1219: case ENETDOWN:
1220: case EHOSTDOWN:
1221: default:
1222: type = ICMP_UNREACH;
1223: code = ICMP_UNREACH_HOST;
1224: break;
1225:
1226: case EMSGSIZE:
1227: type = ICMP_UNREACH;
1228: code = ICMP_UNREACH_NEEDFRAG;
1.13 mycroft 1229: if (ipforward_rt.ro_rt)
1230: destifp = ipforward_rt.ro_rt->rt_ifp;
1.1 cgd 1231: ipstat.ips_cantfrag++;
1232: break;
1233:
1234: case ENOBUFS:
1235: type = ICMP_SOURCEQUENCH;
1236: code = 0;
1237: break;
1238: }
1.13 mycroft 1239: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1240: }
1241:
1242: void
1243: ip_savecontrol(inp, mp, ip, m)
1244: register struct inpcb *inp;
1245: register struct mbuf **mp;
1246: register struct ip *ip;
1247: register struct mbuf *m;
1248: {
1249:
1250: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1251: struct timeval tv;
1252:
1253: microtime(&tv);
1254: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1255: SCM_TIMESTAMP, SOL_SOCKET);
1256: if (*mp)
1257: mp = &(*mp)->m_next;
1258: }
1259: if (inp->inp_flags & INP_RECVDSTADDR) {
1260: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1261: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1262: if (*mp)
1263: mp = &(*mp)->m_next;
1264: }
1265: #ifdef notyet
1266: /*
1267: * XXX
1268: * Moving these out of udp_input() made them even more broken
1269: * than they already were.
1270: * - fenner@parc.xerox.com
1271: */
1272: /* options were tossed already */
1273: if (inp->inp_flags & INP_RECVOPTS) {
1274: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1275: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1276: if (*mp)
1277: mp = &(*mp)->m_next;
1278: }
1279: /* ip_srcroute doesn't do what we want here, need to fix */
1280: if (inp->inp_flags & INP_RECVRETOPTS) {
1281: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1282: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1283: if (*mp)
1284: mp = &(*mp)->m_next;
1285: }
1286: #endif
1287: if (inp->inp_flags & INP_RECVIF) {
1288: struct sockaddr_dl sdl;
1289:
1290: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1291: sdl.sdl_family = AF_LINK;
1292: sdl.sdl_index = m->m_pkthdr.rcvif ?
1293: m->m_pkthdr.rcvif->if_index : 0;
1294: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1295: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1296: IP_RECVIF, IPPROTO_IP);
1297: if (*mp)
1298: mp = &(*mp)->m_next;
1299: }
1.13 mycroft 1300: }
1301:
1302: int
1303: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1304: int *name;
1305: u_int namelen;
1306: void *oldp;
1307: size_t *oldlenp;
1308: void *newp;
1309: size_t newlen;
1310: {
1.52 thorpej 1311: extern int subnetsarelocal;
1312:
1.54 lukem 1313: int error, old;
1314:
1.13 mycroft 1315: /* All sysctl names at this level are terminal. */
1316: if (namelen != 1)
1317: return (ENOTDIR);
1318:
1319: switch (name[0]) {
1320: case IPCTL_FORWARDING:
1321: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1322: case IPCTL_SENDREDIRECTS:
1323: return (sysctl_int(oldp, oldlenp, newp, newlen,
1324: &ipsendredirects));
1325: case IPCTL_DEFTTL:
1326: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1327: #ifdef notyet
1328: case IPCTL_DEFMTU:
1329: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1330: #endif
1.26 thorpej 1331: case IPCTL_FORWSRCRT:
1.47 cjs 1332: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1333: if (securelevel > 0)
1.46 cjs 1334: return (sysctl_rdint(oldp, oldlenp, newp,
1335: ip_forwsrcrt));
1336: else
1337: return (sysctl_int(oldp, oldlenp, newp, newlen,
1338: &ip_forwsrcrt));
1.27 thorpej 1339: case IPCTL_DIRECTEDBCAST:
1340: return (sysctl_int(oldp, oldlenp, newp, newlen,
1341: &ip_directedbcast));
1.47 cjs 1342: case IPCTL_ALLOWSRCRT:
1343: return (sysctl_int(oldp, oldlenp, newp, newlen,
1344: &ip_allowsrcrt));
1.52 thorpej 1345: case IPCTL_SUBNETSARELOCAL:
1346: return (sysctl_int(oldp, oldlenp, newp, newlen,
1347: &subnetsarelocal));
1.53 kml 1348: case IPCTL_MTUDISC:
1.60 kml 1349: error = sysctl_int(oldp, oldlenp, newp, newlen,
1350: &ip_mtudisc);
1351: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1352: ip_mtudisc_timeout_q =
1353: rt_timer_queue_create(ip_mtudisc_timeout);
1354: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1355: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1356: ip_mtudisc_timeout_q = NULL;
1357: }
1358: return error;
1.54 lukem 1359: case IPCTL_ANONPORTMIN:
1360: old = anonportmin;
1361: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1362: if (anonportmin >= anonportmax || anonportmin > 65535
1363: #ifndef IPNOPRIVPORTS
1364: || anonportmin < IPPORT_RESERVED
1365: #endif
1366: ) {
1367: anonportmin = old;
1368: return (EINVAL);
1369: }
1370: return (error);
1371: case IPCTL_ANONPORTMAX:
1372: old = anonportmax;
1373: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1374: if (anonportmin >= anonportmax || anonportmax > 65535
1375: #ifndef IPNOPRIVPORTS
1376: || anonportmax < IPPORT_RESERVED
1377: #endif
1378: ) {
1379: anonportmax = old;
1380: return (EINVAL);
1381: }
1.60 kml 1382: return (error);
1383: case IPCTL_MTUDISCTIMEOUT:
1384: error = sysctl_int(oldp, oldlenp, newp, newlen,
1385: &ip_mtudisc_timeout);
1386: if (ip_mtudisc_timeout_q != NULL)
1387: rt_timer_queue_change(ip_mtudisc_timeout_q,
1388: ip_mtudisc_timeout);
1.54 lukem 1389: return (error);
1.13 mycroft 1390: default:
1391: return (EOPNOTSUPP);
1392: }
1393: /* NOTREACHED */
1.1 cgd 1394: }
CVSweb <webmaster@jp.NetBSD.org>