Annotation of src/sys/netinet/ip_input.c, Revision 1.68
1.68 ! sommerfe 1: /* $NetBSD: ip_input.c,v 1.67 1998/06/01 00:39:37 thorpej 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;
1.68 ! sommerfe 332: m = m0;
! 333: if (m == NULL)
! 334: goto next;
! 335: ip = mtod(m, struct ip *);
1.33 mrg 336: }
1.36 mrg 337: #endif /* PFIL_HOOKS */
1.33 mrg 338:
1.1 cgd 339: /*
340: * Process options and, if not destined for us,
341: * ship it on. ip_dooptions returns 1 when an
342: * error was detected (causing an icmp message
343: * to be sent and the original packet to be freed).
344: */
345: ip_nhops = 0; /* for source routed packets */
346: if (hlen > sizeof (struct ip) && ip_dooptions(m))
347: goto next;
348:
349: /*
350: * Check our list of addresses, to see if the packet is for us.
351: */
1.57 tls 352: INADDR_TO_IA(ip->ip_dst, ia);
353: if (ia != NULL) goto ours;
354: if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
355: for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
356: ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
357: if (ifa->ifa_addr->sa_family != AF_INET) continue;
358: ia = ifatoia(ifa);
1.35 mycroft 359: if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
360: in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20 mycroft 361: /*
362: * Look for all-0's host part (old broadcast addr),
363: * either for subnet or net.
364: */
365: ip->ip_dst.s_addr == ia->ia_subnet ||
1.18 mycroft 366: ip->ip_dst.s_addr == ia->ia_net)
1.1 cgd 367: goto ours;
1.57 tls 368: /*
369: * An interface with IP address zero accepts
370: * all packets that arrive on that interface.
371: */
372: if (in_nullhost(ia->ia_addr.sin_addr))
373: goto ours;
1.1 cgd 374: }
375: }
1.18 mycroft 376: if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4 hpeyerl 377: struct in_multi *inm;
378: #ifdef MROUTING
379: extern struct socket *ip_mrouter;
1.10 brezak 380:
381: if (m->m_flags & M_EXT) {
382: if ((m = m_pullup(m, hlen)) == 0) {
383: ipstat.ips_toosmall++;
384: goto next;
385: }
386: ip = mtod(m, struct ip *);
387: }
1.4 hpeyerl 388:
389: if (ip_mrouter) {
390: /*
391: * If we are acting as a multicast router, all
392: * incoming multicast packets are passed to the
393: * kernel-level multicast forwarding function.
394: * The packet is returned (relatively) intact; if
395: * ip_mforward() returns a non-zero value, the packet
396: * must be discarded, else it may be accepted below.
397: *
398: * (The IP ident field is put in the same byte order
399: * as expected when ip_mforward() is called from
400: * ip_output().)
401: */
402: ip->ip_id = htons(ip->ip_id);
1.13 mycroft 403: if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
404: ipstat.ips_cantforward++;
1.4 hpeyerl 405: m_freem(m);
406: goto next;
407: }
408: ip->ip_id = ntohs(ip->ip_id);
409:
410: /*
411: * The process-level routing demon needs to receive
412: * all multicast IGMP packets, whether or not this
413: * host belongs to their destination groups.
414: */
415: if (ip->ip_p == IPPROTO_IGMP)
416: goto ours;
1.13 mycroft 417: ipstat.ips_forward++;
1.4 hpeyerl 418: }
419: #endif
420: /*
421: * See if we belong to the destination multicast group on the
422: * arrival interface.
423: */
424: IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
425: if (inm == NULL) {
1.13 mycroft 426: ipstat.ips_cantforward++;
1.4 hpeyerl 427: m_freem(m);
428: goto next;
429: }
430: goto ours;
431: }
1.19 mycroft 432: if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35 mycroft 433: in_nullhost(ip->ip_dst))
1.1 cgd 434: goto ours;
435:
436: /*
437: * Not for us; forward if possible and desirable.
438: */
439: if (ipforwarding == 0) {
440: ipstat.ips_cantforward++;
441: m_freem(m);
442: } else
443: ip_forward(m, 0);
444: goto next;
445:
446: ours:
447: /*
448: * If offset or IP_MF are set, must reassemble.
449: * Otherwise, nothing need be done.
450: * (We could look in the reassembly queue to see
451: * if the packet was previously fragmented,
452: * but it's not worth the time; just let them time out.)
453: */
1.37 perry 454: if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1 cgd 455: /*
456: * Look for queue of fragments
457: * of this datagram.
458: */
1.25 cgd 459: for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1 cgd 460: if (ip->ip_id == fp->ipq_id &&
1.35 mycroft 461: in_hosteq(ip->ip_src, fp->ipq_src) &&
462: in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1 cgd 463: ip->ip_p == fp->ipq_p)
464: goto found;
465: fp = 0;
466: found:
467:
468: /*
469: * Adjust ip_len to not reflect header,
1.25 cgd 470: * set ipqe_mff if more fragments are expected,
1.1 cgd 471: * convert offset of this to bytes.
472: */
473: ip->ip_len -= hlen;
1.25 cgd 474: mff = (ip->ip_off & IP_MF) != 0;
475: if (mff) {
1.16 cgd 476: /*
477: * Make sure that fragments have a data length
478: * that's a non-zero multiple of 8 bytes.
479: */
1.17 cgd 480: if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16 cgd 481: ipstat.ips_badfrags++;
482: goto bad;
483: }
484: }
1.1 cgd 485: ip->ip_off <<= 3;
486:
487: /*
488: * If datagram marked as having more fragments
489: * or if this is not the first fragment,
490: * attempt reassembly; if it succeeds, proceed.
491: */
1.25 cgd 492: if (mff || ip->ip_off) {
1.1 cgd 493: ipstat.ips_fragments++;
1.25 cgd 494: MALLOC(ipqe, struct ipqent *, sizeof (struct ipqent),
495: M_IPQ, M_NOWAIT);
496: if (ipqe == NULL) {
497: ipstat.ips_rcvmemdrop++;
498: goto bad;
499: }
500: ipqe->ipqe_mff = mff;
1.50 thorpej 501: ipqe->ipqe_m = m;
1.25 cgd 502: ipqe->ipqe_ip = ip;
1.50 thorpej 503: m = ip_reass(ipqe, fp);
504: if (m == 0)
1.1 cgd 505: goto next;
1.13 mycroft 506: ipstat.ips_reassembled++;
1.50 thorpej 507: ip = mtod(m, struct ip *);
1.1 cgd 508: } else
509: if (fp)
510: ip_freef(fp);
511: } else
512: ip->ip_len -= hlen;
513:
514: /*
515: * Switch out to protocol's input routine.
516: */
517: ipstat.ips_delivered++;
518: (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
519: goto next;
520: bad:
521: m_freem(m);
522: goto next;
523: }
524:
525: /*
526: * Take incoming datagram fragment and try to
527: * reassemble it into whole datagram. If a chain for
528: * reassembly of this datagram already exists, then it
529: * is given as fp; otherwise have to make a chain.
530: */
1.50 thorpej 531: struct mbuf *
1.25 cgd 532: ip_reass(ipqe, fp)
533: register struct ipqent *ipqe;
1.1 cgd 534: register struct ipq *fp;
535: {
1.50 thorpej 536: register struct mbuf *m = ipqe->ipqe_m;
1.25 cgd 537: register struct ipqent *nq, *p, *q;
538: struct ip *ip;
1.1 cgd 539: struct mbuf *t;
1.25 cgd 540: int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1 cgd 541: int i, next;
542:
543: /*
544: * Presence of header sizes in mbufs
545: * would confuse code below.
546: */
547: m->m_data += hlen;
548: m->m_len -= hlen;
549:
550: /*
551: * If first fragment to arrive, create a reassembly queue.
552: */
553: if (fp == 0) {
1.50 thorpej 554: MALLOC(fp, struct ipq *, sizeof (struct ipq),
555: M_FTABLE, M_NOWAIT);
556: if (fp == NULL)
1.1 cgd 557: goto dropfrag;
1.25 cgd 558: LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1 cgd 559: fp->ipq_ttl = IPFRAGTTL;
1.25 cgd 560: fp->ipq_p = ipqe->ipqe_ip->ip_p;
561: fp->ipq_id = ipqe->ipqe_ip->ip_id;
562: LIST_INIT(&fp->ipq_fragq);
563: fp->ipq_src = ipqe->ipqe_ip->ip_src;
564: fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
565: p = NULL;
1.1 cgd 566: goto insert;
567: }
568:
569: /*
570: * Find a segment which begins after this one does.
571: */
1.25 cgd 572: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
573: p = q, q = q->ipqe_q.le_next)
574: if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1 cgd 575: break;
576:
577: /*
578: * If there is a preceding segment, it may provide some of
579: * our data already. If so, drop the data from the incoming
580: * segment. If it provides all of our data, drop us.
581: */
1.25 cgd 582: if (p != NULL) {
583: i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
584: ipqe->ipqe_ip->ip_off;
1.1 cgd 585: if (i > 0) {
1.25 cgd 586: if (i >= ipqe->ipqe_ip->ip_len)
1.1 cgd 587: goto dropfrag;
1.50 thorpej 588: m_adj(ipqe->ipqe_m, i);
1.25 cgd 589: ipqe->ipqe_ip->ip_off += i;
590: ipqe->ipqe_ip->ip_len -= i;
1.1 cgd 591: }
592: }
593:
594: /*
595: * While we overlap succeeding segments trim them or,
596: * if they are completely covered, dequeue them.
597: */
1.25 cgd 598: for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
599: q->ipqe_ip->ip_off; q = nq) {
600: i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
601: q->ipqe_ip->ip_off;
602: if (i < q->ipqe_ip->ip_len) {
603: q->ipqe_ip->ip_len -= i;
604: q->ipqe_ip->ip_off += i;
1.50 thorpej 605: m_adj(q->ipqe_m, i);
1.1 cgd 606: break;
607: }
1.25 cgd 608: nq = q->ipqe_q.le_next;
1.50 thorpej 609: m_freem(q->ipqe_m);
1.25 cgd 610: LIST_REMOVE(q, ipqe_q);
611: FREE(q, M_IPQ);
1.1 cgd 612: }
613:
614: insert:
615: /*
616: * Stick new segment in its place;
617: * check for complete reassembly.
618: */
1.25 cgd 619: if (p == NULL) {
620: LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
621: } else {
622: LIST_INSERT_AFTER(p, ipqe, ipqe_q);
623: }
1.1 cgd 624: next = 0;
1.25 cgd 625: for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
626: p = q, q = q->ipqe_q.le_next) {
627: if (q->ipqe_ip->ip_off != next)
1.1 cgd 628: return (0);
1.25 cgd 629: next += q->ipqe_ip->ip_len;
1.1 cgd 630: }
1.25 cgd 631: if (p->ipqe_mff)
1.1 cgd 632: return (0);
633:
634: /*
1.41 thorpej 635: * Reassembly is complete. Check for a bogus message size and
636: * concatenate fragments.
1.1 cgd 637: */
1.25 cgd 638: q = fp->ipq_fragq.lh_first;
639: ip = q->ipqe_ip;
1.41 thorpej 640: if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
641: ipstat.ips_toolong++;
642: ip_freef(fp);
643: return (0);
644: }
1.50 thorpej 645: m = q->ipqe_m;
1.1 cgd 646: t = m->m_next;
647: m->m_next = 0;
648: m_cat(m, t);
1.25 cgd 649: nq = q->ipqe_q.le_next;
650: FREE(q, M_IPQ);
651: for (q = nq; q != NULL; q = nq) {
1.50 thorpej 652: t = q->ipqe_m;
1.25 cgd 653: nq = q->ipqe_q.le_next;
654: FREE(q, M_IPQ);
1.1 cgd 655: m_cat(m, t);
656: }
657:
658: /*
659: * Create header for new ip packet by
660: * modifying header of first packet;
661: * dequeue and discard fragment reassembly header.
662: * Make header visible.
663: */
664: ip->ip_len = next;
1.25 cgd 665: ip->ip_src = fp->ipq_src;
666: ip->ip_dst = fp->ipq_dst;
667: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 668: FREE(fp, M_FTABLE);
1.1 cgd 669: m->m_len += (ip->ip_hl << 2);
670: m->m_data -= (ip->ip_hl << 2);
671: /* some debugging cruft by sklower, below, will go away soon */
672: if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
673: register int plen = 0;
1.50 thorpej 674: for (t = m; t; t = t->m_next)
675: plen += t->m_len;
676: m->m_pkthdr.len = plen;
1.1 cgd 677: }
1.50 thorpej 678: return (m);
1.1 cgd 679:
680: dropfrag:
681: ipstat.ips_fragdropped++;
682: m_freem(m);
1.25 cgd 683: FREE(ipqe, M_IPQ);
1.1 cgd 684: return (0);
685: }
686:
687: /*
688: * Free a fragment reassembly header and all
689: * associated datagrams.
690: */
1.8 mycroft 691: void
1.1 cgd 692: ip_freef(fp)
693: struct ipq *fp;
694: {
1.25 cgd 695: register struct ipqent *q, *p;
1.1 cgd 696:
1.25 cgd 697: for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
698: p = q->ipqe_q.le_next;
1.50 thorpej 699: m_freem(q->ipqe_m);
1.25 cgd 700: LIST_REMOVE(q, ipqe_q);
701: FREE(q, M_IPQ);
1.1 cgd 702: }
1.25 cgd 703: LIST_REMOVE(fp, ipq_q);
1.50 thorpej 704: FREE(fp, M_FTABLE);
1.1 cgd 705: }
706:
707: /*
708: * IP timer processing;
709: * if a timer expires on a reassembly
710: * queue, discard it.
711: */
1.8 mycroft 712: void
1.1 cgd 713: ip_slowtimo()
714: {
1.25 cgd 715: register struct ipq *fp, *nfp;
1.24 mycroft 716: int s = splsoftnet();
1.1 cgd 717:
1.25 cgd 718: for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
719: nfp = fp->ipq_q.le_next;
720: if (--fp->ipq_ttl == 0) {
1.1 cgd 721: ipstat.ips_fragtimeout++;
1.25 cgd 722: ip_freef(fp);
1.1 cgd 723: }
724: }
1.63 matt 725: #ifdef GATEWAY
726: ipflow_slowtimo();
727: #endif
1.1 cgd 728: splx(s);
729: }
730:
731: /*
732: * Drain off all datagram fragments.
733: */
1.8 mycroft 734: void
1.1 cgd 735: ip_drain()
736: {
737:
1.25 cgd 738: while (ipq.lh_first != NULL) {
1.1 cgd 739: ipstat.ips_fragdropped++;
1.25 cgd 740: ip_freef(ipq.lh_first);
1.1 cgd 741: }
742: }
743:
744: /*
745: * Do option processing on a datagram,
746: * possibly discarding it if bad options are encountered,
747: * or forwarding it if source-routed.
748: * Returns 1 if packet has been forwarded/freed,
749: * 0 if the packet should be processed further.
750: */
1.8 mycroft 751: int
1.1 cgd 752: ip_dooptions(m)
753: struct mbuf *m;
754: {
755: register struct ip *ip = mtod(m, struct ip *);
756: register u_char *cp;
757: register struct ip_timestamp *ipt;
758: register struct in_ifaddr *ia;
759: int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13 mycroft 760: struct in_addr *sin, dst;
1.1 cgd 761: n_time ntime;
762:
1.13 mycroft 763: dst = ip->ip_dst;
1.1 cgd 764: cp = (u_char *)(ip + 1);
765: cnt = (ip->ip_hl << 2) - sizeof (struct ip);
766: for (; cnt > 0; cnt -= optlen, cp += optlen) {
767: opt = cp[IPOPT_OPTVAL];
768: if (opt == IPOPT_EOL)
769: break;
770: if (opt == IPOPT_NOP)
771: optlen = 1;
772: else {
773: optlen = cp[IPOPT_OLEN];
774: if (optlen <= 0 || optlen > cnt) {
775: code = &cp[IPOPT_OLEN] - (u_char *)ip;
776: goto bad;
777: }
778: }
779: switch (opt) {
780:
781: default:
782: break;
783:
784: /*
785: * Source routing with record.
786: * Find interface with current destination address.
787: * If none on this machine then drop if strictly routed,
788: * or do nothing if loosely routed.
789: * Record interface address and bring up next address
790: * component. If strictly routed make sure next
791: * address is on directly accessible net.
792: */
793: case IPOPT_LSRR:
794: case IPOPT_SSRR:
1.47 cjs 795: if (ip_allowsrcrt == 0) {
796: type = ICMP_UNREACH;
797: code = ICMP_UNREACH_NET_PROHIB;
798: goto bad;
799: }
1.1 cgd 800: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
801: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
802: goto bad;
803: }
804: ipaddr.sin_addr = ip->ip_dst;
1.19 mycroft 805: ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1 cgd 806: if (ia == 0) {
807: if (opt == IPOPT_SSRR) {
808: type = ICMP_UNREACH;
809: code = ICMP_UNREACH_SRCFAIL;
810: goto bad;
811: }
812: /*
813: * Loose routing, and not at next destination
814: * yet; nothing to do except forward.
815: */
816: break;
817: }
818: off--; /* 0 origin */
819: if (off > optlen - sizeof(struct in_addr)) {
820: /*
821: * End of source route. Should be for us.
822: */
823: save_rte(cp, ip->ip_src);
824: break;
825: }
826: /*
827: * locate outgoing interface
828: */
829: bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
830: sizeof(ipaddr.sin_addr));
831: if (opt == IPOPT_SSRR) {
832: #define INA struct in_ifaddr *
833: #define SA struct sockaddr *
1.29 mrg 834: ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1 cgd 835: } else
836: ia = ip_rtaddr(ipaddr.sin_addr);
837: if (ia == 0) {
838: type = ICMP_UNREACH;
839: code = ICMP_UNREACH_SRCFAIL;
840: goto bad;
841: }
842: ip->ip_dst = ipaddr.sin_addr;
1.20 mycroft 843: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 844: (caddr_t)(cp + off), sizeof(struct in_addr));
845: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13 mycroft 846: /*
847: * Let ip_intr's mcast routing check handle mcast pkts
848: */
1.18 mycroft 849: forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1 cgd 850: break;
851:
852: case IPOPT_RR:
853: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
854: code = &cp[IPOPT_OFFSET] - (u_char *)ip;
855: goto bad;
856: }
857: /*
858: * If no space remains, ignore.
859: */
860: off--; /* 0 origin */
861: if (off > optlen - sizeof(struct in_addr))
862: break;
863: bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
864: sizeof(ipaddr.sin_addr));
865: /*
866: * locate outgoing interface; if we're the destination,
867: * use the incoming interface (should be same).
868: */
869: if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
870: (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
871: type = ICMP_UNREACH;
872: code = ICMP_UNREACH_HOST;
873: goto bad;
874: }
1.20 mycroft 875: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 876: (caddr_t)(cp + off), sizeof(struct in_addr));
877: cp[IPOPT_OFFSET] += sizeof(struct in_addr);
878: break;
879:
880: case IPOPT_TS:
881: code = cp - (u_char *)ip;
882: ipt = (struct ip_timestamp *)cp;
883: if (ipt->ipt_len < 5)
884: goto bad;
1.15 cgd 885: if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1 cgd 886: if (++ipt->ipt_oflw == 0)
887: goto bad;
888: break;
889: }
890: sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
891: switch (ipt->ipt_flg) {
892:
893: case IPOPT_TS_TSONLY:
894: break;
895:
896: case IPOPT_TS_TSANDADDR:
1.66 thorpej 897: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 898: sizeof(struct in_addr) > ipt->ipt_len)
899: goto bad;
1.13 mycroft 900: ipaddr.sin_addr = dst;
901: ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
902: m->m_pkthdr.rcvif);
903: if (ia == 0)
904: continue;
1.20 mycroft 905: bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1 cgd 906: (caddr_t)sin, sizeof(struct in_addr));
907: ipt->ipt_ptr += sizeof(struct in_addr);
908: break;
909:
910: case IPOPT_TS_PRESPEC:
1.66 thorpej 911: if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.1 cgd 912: sizeof(struct in_addr) > ipt->ipt_len)
913: goto bad;
914: bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
915: sizeof(struct in_addr));
916: if (ifa_ifwithaddr((SA)&ipaddr) == 0)
917: continue;
918: ipt->ipt_ptr += sizeof(struct in_addr);
919: break;
920:
921: default:
922: goto bad;
923: }
924: ntime = iptime();
925: bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
926: sizeof(n_time));
927: ipt->ipt_ptr += sizeof(n_time);
928: }
929: }
930: if (forward) {
1.26 thorpej 931: if (ip_forwsrcrt == 0) {
932: type = ICMP_UNREACH;
933: code = ICMP_UNREACH_SRCFAIL;
934: goto bad;
935: }
1.1 cgd 936: ip_forward(m, 1);
937: return (1);
1.13 mycroft 938: }
939: return (0);
1.1 cgd 940: bad:
1.13 mycroft 941: ip->ip_len -= ip->ip_hl << 2; /* XXX icmp_error adds in hdr length */
942: icmp_error(m, type, code, 0, 0);
943: ipstat.ips_badoptions++;
1.1 cgd 944: return (1);
945: }
946:
947: /*
948: * Given address of next destination (final or next hop),
949: * return internet address info of interface to be used to get there.
950: */
951: struct in_ifaddr *
952: ip_rtaddr(dst)
953: struct in_addr dst;
954: {
955: register struct sockaddr_in *sin;
956:
1.19 mycroft 957: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 958:
1.35 mycroft 959: if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1 cgd 960: if (ipforward_rt.ro_rt) {
961: RTFREE(ipforward_rt.ro_rt);
962: ipforward_rt.ro_rt = 0;
963: }
964: sin->sin_family = AF_INET;
965: sin->sin_len = sizeof(*sin);
966: sin->sin_addr = dst;
967:
968: rtalloc(&ipforward_rt);
969: }
970: if (ipforward_rt.ro_rt == 0)
971: return ((struct in_ifaddr *)0);
1.19 mycroft 972: return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1 cgd 973: }
974:
975: /*
976: * Save incoming source route for use in replies,
977: * to be picked up later by ip_srcroute if the receiver is interested.
978: */
1.13 mycroft 979: void
1.1 cgd 980: save_rte(option, dst)
981: u_char *option;
982: struct in_addr dst;
983: {
984: unsigned olen;
985:
986: olen = option[IPOPT_OLEN];
987: #ifdef DIAGNOSTIC
988: if (ipprintfs)
1.39 christos 989: printf("save_rte: olen %d\n", olen);
1.1 cgd 990: #endif
991: if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
992: return;
993: bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
994: ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
995: ip_srcrt.dst = dst;
996: }
997:
998: /*
999: * Retrieve incoming source route for use in replies,
1000: * in the same form used by setsockopt.
1001: * The first hop is placed before the options, will be removed later.
1002: */
1003: struct mbuf *
1004: ip_srcroute()
1005: {
1006: register struct in_addr *p, *q;
1007: register struct mbuf *m;
1008:
1009: if (ip_nhops == 0)
1010: return ((struct mbuf *)0);
1011: m = m_get(M_DONTWAIT, MT_SOOPTS);
1012: if (m == 0)
1013: return ((struct mbuf *)0);
1014:
1.13 mycroft 1015: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1 cgd 1016:
1017: /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1018: m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1019: OPTSIZ;
1020: #ifdef DIAGNOSTIC
1021: if (ipprintfs)
1.39 christos 1022: printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1 cgd 1023: #endif
1024:
1025: /*
1026: * First save first hop for return route
1027: */
1028: p = &ip_srcrt.route[ip_nhops - 1];
1029: *(mtod(m, struct in_addr *)) = *p--;
1030: #ifdef DIAGNOSTIC
1031: if (ipprintfs)
1.39 christos 1032: printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1 cgd 1033: #endif
1034:
1035: /*
1036: * Copy option fields and padding (nop) to mbuf.
1037: */
1038: ip_srcrt.nop = IPOPT_NOP;
1039: ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1040: bcopy((caddr_t)&ip_srcrt.nop,
1041: mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
1042: q = (struct in_addr *)(mtod(m, caddr_t) +
1043: sizeof(struct in_addr) + OPTSIZ);
1044: #undef OPTSIZ
1045: /*
1046: * Record return path as an IP source route,
1047: * reversing the path (pointers are now aligned).
1048: */
1049: while (p >= ip_srcrt.route) {
1050: #ifdef DIAGNOSTIC
1051: if (ipprintfs)
1.39 christos 1052: printf(" %x", ntohl(q->s_addr));
1.1 cgd 1053: #endif
1054: *q++ = *p--;
1055: }
1056: /*
1057: * Last hop goes to final destination.
1058: */
1059: *q = ip_srcrt.dst;
1060: #ifdef DIAGNOSTIC
1061: if (ipprintfs)
1.39 christos 1062: printf(" %x\n", ntohl(q->s_addr));
1.1 cgd 1063: #endif
1064: return (m);
1065: }
1066:
1067: /*
1068: * Strip out IP options, at higher
1069: * level protocol in the kernel.
1070: * Second argument is buffer to which options
1071: * will be moved, and return value is their length.
1072: * XXX should be deleted; last arg currently ignored.
1073: */
1.8 mycroft 1074: void
1.1 cgd 1075: ip_stripoptions(m, mopt)
1076: register struct mbuf *m;
1077: struct mbuf *mopt;
1078: {
1079: register int i;
1080: struct ip *ip = mtod(m, struct ip *);
1081: register caddr_t opts;
1082: int olen;
1083:
1084: olen = (ip->ip_hl<<2) - sizeof (struct ip);
1085: opts = (caddr_t)(ip + 1);
1086: i = m->m_len - (sizeof (struct ip) + olen);
1087: bcopy(opts + olen, opts, (unsigned)i);
1088: m->m_len -= olen;
1089: if (m->m_flags & M_PKTHDR)
1090: m->m_pkthdr.len -= olen;
1091: ip->ip_hl = sizeof(struct ip) >> 2;
1092: }
1093:
1.23 mycroft 1094: int inetctlerrmap[PRC_NCMDS] = {
1.1 cgd 1095: 0, 0, 0, 0,
1096: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1097: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1098: EMSGSIZE, EHOSTUNREACH, 0, 0,
1099: 0, 0, 0, 0,
1100: ENOPROTOOPT
1101: };
1102:
1103: /*
1104: * Forward a packet. If some error occurs return the sender
1105: * an icmp packet. Note we can't always generate a meaningful
1106: * icmp message because icmp doesn't have a large enough repertoire
1107: * of codes and types.
1108: *
1109: * If not forwarding, just drop the packet. This could be confusing
1110: * if ipforwarding was zero but some routing protocol was advancing
1111: * us as a gateway to somewhere. However, we must let the routing
1112: * protocol deal with that.
1113: *
1114: * The srcrt parameter indicates whether the packet is being forwarded
1115: * via a source route.
1116: */
1.13 mycroft 1117: void
1.1 cgd 1118: ip_forward(m, srcrt)
1119: struct mbuf *m;
1120: int srcrt;
1121: {
1122: register struct ip *ip = mtod(m, struct ip *);
1123: register struct sockaddr_in *sin;
1124: register struct rtentry *rt;
1.28 christos 1125: int error, type = 0, code = 0;
1.1 cgd 1126: struct mbuf *mcopy;
1.13 mycroft 1127: n_long dest;
1128: struct ifnet *destifp;
1.1 cgd 1129:
1.13 mycroft 1130: dest = 0;
1.1 cgd 1131: #ifdef DIAGNOSTIC
1132: if (ipprintfs)
1.39 christos 1133: printf("forward: src %x dst %x ttl %x\n",
1.35 mycroft 1134: ip->ip_src.s_addr, ip->ip_dst.s_addr, ip->ip_ttl);
1.1 cgd 1135: #endif
1136: if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
1137: ipstat.ips_cantforward++;
1138: m_freem(m);
1139: return;
1140: }
1141: HTONS(ip->ip_id);
1142: if (ip->ip_ttl <= IPTTLDEC) {
1.13 mycroft 1143: icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1 cgd 1144: return;
1145: }
1146: ip->ip_ttl -= IPTTLDEC;
1147:
1.19 mycroft 1148: sin = satosin(&ipforward_rt.ro_dst);
1.1 cgd 1149: if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35 mycroft 1150: !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1 cgd 1151: if (ipforward_rt.ro_rt) {
1152: RTFREE(ipforward_rt.ro_rt);
1153: ipforward_rt.ro_rt = 0;
1154: }
1155: sin->sin_family = AF_INET;
1.35 mycroft 1156: sin->sin_len = sizeof(struct sockaddr_in);
1.1 cgd 1157: sin->sin_addr = ip->ip_dst;
1158:
1159: rtalloc(&ipforward_rt);
1160: if (ipforward_rt.ro_rt == 0) {
1.13 mycroft 1161: icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1 cgd 1162: return;
1163: }
1164: rt = ipforward_rt.ro_rt;
1165: }
1166:
1167: /*
1.34 mycroft 1168: * Save at most 68 bytes of the packet in case
1.1 cgd 1169: * we need to generate an ICMP message to the src.
1170: */
1.34 mycroft 1171: mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1 cgd 1172:
1173: /*
1174: * If forwarding packet using same interface that it came in on,
1175: * perhaps should send a redirect to sender to shortcut a hop.
1176: * Only send redirect if source is sending directly to us,
1177: * and if packet was not source routed (or has any options).
1178: * Also, don't send redirect if forwarding using a default route
1179: * or a route modified by a redirect.
1180: */
1181: if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1182: (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35 mycroft 1183: !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1 cgd 1184: ipsendredirects && !srcrt) {
1.19 mycroft 1185: if (rt->rt_ifa &&
1186: (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1187: ifatoia(rt->rt_ifa)->ia_subnet) {
1.1 cgd 1188: if (rt->rt_flags & RTF_GATEWAY)
1.13 mycroft 1189: dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1.1 cgd 1190: else
1.13 mycroft 1191: dest = ip->ip_dst.s_addr;
1192: /* Router requirements says to only send host redirects */
1.1 cgd 1193: type = ICMP_REDIRECT;
1.13 mycroft 1194: code = ICMP_REDIRECT_HOST;
1.1 cgd 1195: #ifdef DIAGNOSTIC
1196: if (ipprintfs)
1.39 christos 1197: printf("redirect (%d) to %x\n", code, (u_int32_t)dest);
1.1 cgd 1198: #endif
1199: }
1200: }
1201:
1.27 thorpej 1202: error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1203: (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1 cgd 1204: if (error)
1205: ipstat.ips_cantforward++;
1206: else {
1207: ipstat.ips_forward++;
1208: if (type)
1209: ipstat.ips_redirectsent++;
1210: else {
1.63 matt 1211: if (mcopy) {
1212: #ifdef GATEWAY
1.64 thorpej 1213: if (mcopy->m_flags & M_CANFASTFWD)
1214: ipflow_create(&ipforward_rt, mcopy);
1.63 matt 1215: #endif
1.1 cgd 1216: m_freem(mcopy);
1.63 matt 1217: }
1.1 cgd 1218: return;
1219: }
1220: }
1221: if (mcopy == NULL)
1222: return;
1.13 mycroft 1223: destifp = NULL;
1224:
1.1 cgd 1225: switch (error) {
1226:
1227: case 0: /* forwarded, but need redirect */
1228: /* type, code set above */
1229: break;
1230:
1231: case ENETUNREACH: /* shouldn't happen, checked above */
1232: case EHOSTUNREACH:
1233: case ENETDOWN:
1234: case EHOSTDOWN:
1235: default:
1236: type = ICMP_UNREACH;
1237: code = ICMP_UNREACH_HOST;
1238: break;
1239:
1240: case EMSGSIZE:
1241: type = ICMP_UNREACH;
1242: code = ICMP_UNREACH_NEEDFRAG;
1.13 mycroft 1243: if (ipforward_rt.ro_rt)
1244: destifp = ipforward_rt.ro_rt->rt_ifp;
1.1 cgd 1245: ipstat.ips_cantfrag++;
1246: break;
1247:
1248: case ENOBUFS:
1249: type = ICMP_SOURCEQUENCH;
1250: code = 0;
1251: break;
1252: }
1.13 mycroft 1253: icmp_error(mcopy, type, code, dest, destifp);
1.44 thorpej 1254: }
1255:
1256: void
1257: ip_savecontrol(inp, mp, ip, m)
1258: register struct inpcb *inp;
1259: register struct mbuf **mp;
1260: register struct ip *ip;
1261: register struct mbuf *m;
1262: {
1263:
1264: if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1265: struct timeval tv;
1266:
1267: microtime(&tv);
1268: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1269: SCM_TIMESTAMP, SOL_SOCKET);
1270: if (*mp)
1271: mp = &(*mp)->m_next;
1272: }
1273: if (inp->inp_flags & INP_RECVDSTADDR) {
1274: *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1275: sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1276: if (*mp)
1277: mp = &(*mp)->m_next;
1278: }
1279: #ifdef notyet
1280: /*
1281: * XXX
1282: * Moving these out of udp_input() made them even more broken
1283: * than they already were.
1284: * - fenner@parc.xerox.com
1285: */
1286: /* options were tossed already */
1287: if (inp->inp_flags & INP_RECVOPTS) {
1288: *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1289: sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1290: if (*mp)
1291: mp = &(*mp)->m_next;
1292: }
1293: /* ip_srcroute doesn't do what we want here, need to fix */
1294: if (inp->inp_flags & INP_RECVRETOPTS) {
1295: *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1296: sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1297: if (*mp)
1298: mp = &(*mp)->m_next;
1299: }
1300: #endif
1301: if (inp->inp_flags & INP_RECVIF) {
1302: struct sockaddr_dl sdl;
1303:
1304: sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1305: sdl.sdl_family = AF_LINK;
1306: sdl.sdl_index = m->m_pkthdr.rcvif ?
1307: m->m_pkthdr.rcvif->if_index : 0;
1308: sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1309: *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1310: IP_RECVIF, IPPROTO_IP);
1311: if (*mp)
1312: mp = &(*mp)->m_next;
1313: }
1.13 mycroft 1314: }
1315:
1316: int
1317: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1318: int *name;
1319: u_int namelen;
1320: void *oldp;
1321: size_t *oldlenp;
1322: void *newp;
1323: size_t newlen;
1324: {
1.52 thorpej 1325: extern int subnetsarelocal;
1326:
1.54 lukem 1327: int error, old;
1328:
1.13 mycroft 1329: /* All sysctl names at this level are terminal. */
1330: if (namelen != 1)
1331: return (ENOTDIR);
1332:
1333: switch (name[0]) {
1334: case IPCTL_FORWARDING:
1335: return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
1336: case IPCTL_SENDREDIRECTS:
1337: return (sysctl_int(oldp, oldlenp, newp, newlen,
1338: &ipsendredirects));
1339: case IPCTL_DEFTTL:
1340: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
1341: #ifdef notyet
1342: case IPCTL_DEFMTU:
1343: return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
1344: #endif
1.26 thorpej 1345: case IPCTL_FORWSRCRT:
1.47 cjs 1346: /* Don't allow this to change in a secure environment. */
1.26 thorpej 1347: if (securelevel > 0)
1.46 cjs 1348: return (sysctl_rdint(oldp, oldlenp, newp,
1349: ip_forwsrcrt));
1350: else
1351: return (sysctl_int(oldp, oldlenp, newp, newlen,
1352: &ip_forwsrcrt));
1.27 thorpej 1353: case IPCTL_DIRECTEDBCAST:
1354: return (sysctl_int(oldp, oldlenp, newp, newlen,
1355: &ip_directedbcast));
1.47 cjs 1356: case IPCTL_ALLOWSRCRT:
1357: return (sysctl_int(oldp, oldlenp, newp, newlen,
1358: &ip_allowsrcrt));
1.52 thorpej 1359: case IPCTL_SUBNETSARELOCAL:
1360: return (sysctl_int(oldp, oldlenp, newp, newlen,
1361: &subnetsarelocal));
1.53 kml 1362: case IPCTL_MTUDISC:
1.60 kml 1363: error = sysctl_int(oldp, oldlenp, newp, newlen,
1364: &ip_mtudisc);
1365: if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
1366: ip_mtudisc_timeout_q =
1367: rt_timer_queue_create(ip_mtudisc_timeout);
1368: } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
1369: rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
1370: ip_mtudisc_timeout_q = NULL;
1371: }
1372: return error;
1.54 lukem 1373: case IPCTL_ANONPORTMIN:
1374: old = anonportmin;
1375: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1376: if (anonportmin >= anonportmax || anonportmin > 65535
1377: #ifndef IPNOPRIVPORTS
1378: || anonportmin < IPPORT_RESERVED
1379: #endif
1380: ) {
1381: anonportmin = old;
1382: return (EINVAL);
1383: }
1384: return (error);
1385: case IPCTL_ANONPORTMAX:
1386: old = anonportmax;
1387: error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1388: if (anonportmin >= anonportmax || anonportmax > 65535
1389: #ifndef IPNOPRIVPORTS
1390: || anonportmax < IPPORT_RESERVED
1391: #endif
1392: ) {
1393: anonportmax = old;
1394: return (EINVAL);
1395: }
1.60 kml 1396: return (error);
1397: case IPCTL_MTUDISCTIMEOUT:
1398: error = sysctl_int(oldp, oldlenp, newp, newlen,
1399: &ip_mtudisc_timeout);
1400: if (ip_mtudisc_timeout_q != NULL)
1401: rt_timer_queue_change(ip_mtudisc_timeout_q,
1402: ip_mtudisc_timeout);
1.54 lukem 1403: return (error);
1.65 matt 1404: #ifdef GATEWAY
1405: case IPCTL_MAXFLOWS:
1.67 thorpej 1406: {
1407: int s;
1408:
1.65 matt 1409: error = sysctl_int(oldp, oldlenp, newp, newlen,
1410: &ip_maxflows);
1.67 thorpej 1411: s = splsoftnet();
1.65 matt 1412: ipflow_reap(0);
1.67 thorpej 1413: splx(s);
1.65 matt 1414: return (error);
1.67 thorpej 1415: }
1.65 matt 1416: #endif
1.13 mycroft 1417: default:
1418: return (EOPNOTSUPP);
1419: }
1420: /* NOTREACHED */
1.1 cgd 1421: }
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