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1.1 nbrk 1: /* $OpenBSD: ip6_input.c,v 1.78 2007/08/03 06:43:12 itojun Exp $ */
2: /* $KAME: ip6_input.c,v 1.188 2001/03/29 05:34:31 itojun Exp $ */
3:
4: /*
5: * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6: * All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
16: * 3. Neither the name of the project nor the names of its contributors
17: * may be used to endorse or promote products derived from this software
18: * without specific prior written permission.
19: *
20: * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23: * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30: * SUCH DAMAGE.
31: */
32:
33: /*
34: * Copyright (c) 1982, 1986, 1988, 1993
35: * The Regents of the University of California. All rights reserved.
36: *
37: * Redistribution and use in source and binary forms, with or without
38: * modification, are permitted provided that the following conditions
39: * are met:
40: * 1. Redistributions of source code must retain the above copyright
41: * notice, this list of conditions and the following disclaimer.
42: * 2. Redistributions in binary form must reproduce the above copyright
43: * notice, this list of conditions and the following disclaimer in the
44: * documentation and/or other materials provided with the distribution.
45: * 3. Neither the name of the University nor the names of its contributors
46: * may be used to endorse or promote products derived from this software
47: * without specific prior written permission.
48: *
49: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59: * SUCH DAMAGE.
60: *
61: * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
62: */
63:
64: #include "pf.h"
65: #include "carp.h"
66:
67: #include <sys/param.h>
68: #include <sys/systm.h>
69: #include <sys/malloc.h>
70: #include <sys/mbuf.h>
71: #include <sys/domain.h>
72: #include <sys/protosw.h>
73: #include <sys/socket.h>
74: #include <sys/socketvar.h>
75: #include <sys/errno.h>
76: #include <sys/time.h>
77: #include <sys/kernel.h>
78: #include <sys/syslog.h>
79: #include <sys/proc.h>
80:
81: #include <net/if.h>
82: #include <net/if_types.h>
83: #include <net/if_dl.h>
84: #include <net/route.h>
85: #include <net/netisr.h>
86:
87: #include <netinet/in.h>
88: #include <netinet/in_systm.h>
89:
90: #ifdef INET
91: #include <netinet/ip.h>
92: #include <netinet/ip_icmp.h>
93: #endif /*INET*/
94:
95: #include <netinet/in_pcb.h>
96: #include <netinet6/in6_var.h>
97: #include <netinet/ip6.h>
98: #include <netinet6/ip6_var.h>
99: #include <netinet/icmp6.h>
100: #include <netinet6/in6_ifattach.h>
101: #include <netinet6/nd6.h>
102:
103: #include <netinet6/ip6protosw.h>
104:
105: #include "faith.h"
106: #include "gif.h"
107: #include "bpfilter.h"
108:
109: #if NPF > 0
110: #include <net/pfvar.h>
111: #endif
112:
113: #if NCARP > 0
114: #include <netinet/in_var.h>
115: #include <netinet/ip_carp.h>
116: #endif
117:
118: extern struct domain inet6domain;
119: extern struct ip6protosw inet6sw[];
120:
121: u_char ip6_protox[IPPROTO_MAX];
122: static int ip6qmaxlen = IFQ_MAXLEN;
123: struct in6_ifaddr *in6_ifaddr;
124: struct ifqueue ip6intrq;
125:
126: int ip6_forward_srcrt; /* XXX */
127: int ip6_sourcecheck; /* XXX */
128: int ip6_sourcecheck_interval; /* XXX */
129:
130: struct ip6stat ip6stat;
131:
132: static void ip6_init2(void *);
133: int ip6_check_rh0hdr(struct mbuf *);
134:
135: static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
136: static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
137:
138: /*
139: * IP6 initialization: fill in IP6 protocol switch table.
140: * All protocols not implemented in kernel go to raw IP6 protocol handler.
141: */
142: void
143: ip6_init()
144: {
145: struct ip6protosw *pr;
146: int i;
147:
148: pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
149: if (pr == 0)
150: panic("ip6_init");
151: for (i = 0; i < IPPROTO_MAX; i++)
152: ip6_protox[i] = pr - inet6sw;
153: for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
154: pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
155: if (pr->pr_domain->dom_family == PF_INET6 &&
156: pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
157: ip6_protox[pr->pr_protocol] = pr - inet6sw;
158: ip6intrq.ifq_maxlen = ip6qmaxlen;
159: nd6_init();
160: frag6_init();
161: ip6_init2((void *)0);
162: }
163:
164: static void
165: ip6_init2(dummy)
166: void *dummy;
167: {
168:
169: /* nd6_timer_init */
170: bzero(&nd6_timer_ch, sizeof(nd6_timer_ch));
171: timeout_set(&nd6_timer_ch, nd6_timer, NULL);
172: timeout_add(&nd6_timer_ch, hz);
173: }
174:
175: /*
176: * IP6 input interrupt handling. Just pass the packet to ip6_input.
177: */
178: void
179: ip6intr()
180: {
181: int s;
182: struct mbuf *m;
183:
184: while (ip6intrq.ifq_head) {
185: s = splnet();
186: IF_DEQUEUE(&ip6intrq, m);
187: splx(s);
188: if (m == 0)
189: return;
190: ip6_input(m);
191: }
192: }
193:
194: extern struct route_in6 ip6_forward_rt;
195: extern int ip6_forward_rtableid;
196:
197: void
198: ip6_input(m)
199: struct mbuf *m;
200: {
201: struct ip6_hdr *ip6;
202: int off = sizeof(struct ip6_hdr), nest;
203: u_int32_t plen;
204: u_int32_t rtalert = ~0;
205: int nxt, ours = 0;
206: struct ifnet *deliverifp = NULL;
207: #if NPF > 0
208: struct in6_addr odst;
209: #endif
210: int srcrt = 0, rtableid = 0;
211:
212: /*
213: * mbuf statistics by kazu
214: */
215: if (m->m_flags & M_EXT) {
216: if (m->m_next)
217: ip6stat.ip6s_mext2m++;
218: else
219: ip6stat.ip6s_mext1++;
220: } else {
221: #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0]))
222: if (m->m_next) {
223: if (m->m_flags & M_LOOP) {
224: ip6stat.ip6s_m2m[lo0ifp->if_index]++; /*XXX*/
225: } else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
226: ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
227: else
228: ip6stat.ip6s_m2m[0]++;
229: } else
230: ip6stat.ip6s_m1++;
231: #undef M2MMAX
232: }
233:
234: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
235: ip6stat.ip6s_total++;
236:
237: if (m->m_len < sizeof(struct ip6_hdr)) {
238: struct ifnet *inifp;
239: inifp = m->m_pkthdr.rcvif;
240: if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
241: ip6stat.ip6s_toosmall++;
242: in6_ifstat_inc(inifp, ifs6_in_hdrerr);
243: return;
244: }
245: }
246:
247: ip6 = mtod(m, struct ip6_hdr *);
248:
249: if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
250: ip6stat.ip6s_badvers++;
251: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
252: goto bad;
253: }
254:
255: #if NCARP > 0
256: if (m->m_pkthdr.rcvif->if_type == IFT_CARP &&
257: m->m_pkthdr.rcvif->if_flags & IFF_LINK0 &&
258: ip6->ip6_nxt != IPPROTO_ICMPV6 &&
259: carp_lsdrop(m, AF_INET6, ip6->ip6_src.s6_addr32,
260: ip6->ip6_dst.s6_addr32))
261: goto bad;
262: #endif
263: ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
264:
265: /*
266: * Check against address spoofing/corruption.
267: */
268: if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
269: IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
270: /*
271: * XXX: "badscope" is not very suitable for a multicast source.
272: */
273: ip6stat.ip6s_badscope++;
274: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
275: goto bad;
276: }
277:
278: if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
279: !(m->m_flags & M_LOOP)) {
280: /*
281: * In this case, the packet should come from the loopback
282: * interface. However, we cannot just check the if_flags,
283: * because ip6_mloopback() passes the "actual" interface
284: * as the outgoing/incoming interface.
285: */
286: ip6stat.ip6s_badscope++;
287: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
288: goto bad;
289: }
290:
291: /*
292: * The following check is not documented in specs. A malicious
293: * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
294: * and bypass security checks (act as if it was from 127.0.0.1 by using
295: * IPv6 src ::ffff:127.0.0.1). Be cautious.
296: *
297: * This check chokes if we are in an SIIT cloud. As none of BSDs
298: * support IPv4-less kernel compilation, we cannot support SIIT
299: * environment at all. So, it makes more sense for us to reject any
300: * malicious packets for non-SIIT environment, than try to do a
301: * partial support for SIIT environment.
302: */
303: if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
304: IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
305: ip6stat.ip6s_badscope++;
306: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
307: goto bad;
308: }
309: #if 0
310: /*
311: * Reject packets with IPv4 compatible addresses (auto tunnel).
312: *
313: * The code forbids auto tunnel relay case in RFC1933 (the check is
314: * stronger than RFC1933). We may want to re-enable it if mech-xx
315: * is revised to forbid relaying case.
316: */
317: if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
318: IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
319: ip6stat.ip6s_badscope++;
320: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
321: goto bad;
322: }
323: #endif
324:
325: if (ip6_check_rh0hdr(m)) {
326: ip6stat.ip6s_badoptions++;
327: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
328: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
329: icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, 0);
330: /* m is allready freed */
331: return;
332: }
333:
334: #if NPF > 0
335: /*
336: * Packet filter
337: */
338: odst = ip6->ip6_dst;
339: if (pf_test6(PF_IN, m->m_pkthdr.rcvif, &m, NULL) != PF_PASS)
340: goto bad;
341: if (m == NULL)
342: return;
343:
344: ip6 = mtod(m, struct ip6_hdr *);
345: srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
346: #endif
347:
348: if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) ||
349: IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) {
350: if (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) {
351: ours = 1;
352: deliverifp = m->m_pkthdr.rcvif;
353: goto hbhcheck;
354: } else {
355: ip6stat.ip6s_badscope++;
356: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
357: goto bad;
358: }
359: }
360:
361: /* drop packets if interface ID portion is already filled */
362: if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
363: if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src) &&
364: ip6->ip6_src.s6_addr16[1]) {
365: ip6stat.ip6s_badscope++;
366: goto bad;
367: }
368: if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst) &&
369: ip6->ip6_dst.s6_addr16[1]) {
370: ip6stat.ip6s_badscope++;
371: goto bad;
372: }
373: }
374:
375: if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src))
376: ip6->ip6_src.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
377: if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst))
378: ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
379:
380: /*
381: * We use rt->rt_ifp to determine if the address is ours or not.
382: * If rt_ifp is lo0, the address is ours.
383: * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0,
384: * so any address under fe80::%lo0/64 will be mistakenly considered
385: * local. The special case is supplied to handle the case properly
386: * by actually looking at interface addresses
387: * (using in6ifa_ifpwithaddr).
388: */
389: if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 &&
390: IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) {
391: if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) {
392: icmp6_error(m, ICMP6_DST_UNREACH,
393: ICMP6_DST_UNREACH_ADDR, 0);
394: /* m is already freed */
395: return;
396: }
397:
398: ours = 1;
399: deliverifp = m->m_pkthdr.rcvif;
400: goto hbhcheck;
401: }
402:
403: /*
404: * Multicast check
405: */
406: if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
407: struct in6_multi *in6m = 0;
408:
409: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
410: /*
411: * See if we belong to the destination multicast group on the
412: * arrival interface.
413: */
414: IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
415: if (in6m)
416: ours = 1;
417: #ifdef MROUTING
418: else if (!ip6_mforwarding || !ip6_mrouter)
419: #else
420: else
421: #endif
422: {
423: ip6stat.ip6s_notmember++;
424: if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
425: ip6stat.ip6s_cantforward++;
426: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
427: goto bad;
428: }
429: deliverifp = m->m_pkthdr.rcvif;
430: goto hbhcheck;
431: }
432:
433: #if NPF > 0
434: rtableid = m->m_pkthdr.pf.rtableid;
435: #endif
436:
437: /*
438: * Unicast check
439: */
440: if (ip6_forward_rt.ro_rt != NULL &&
441: (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 &&
442: IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
443: &ip6_forward_rt.ro_dst.sin6_addr) &&
444: rtableid == ip6_forward_rtableid)
445: ip6stat.ip6s_forward_cachehit++;
446: else {
447: if (ip6_forward_rt.ro_rt) {
448: /* route is down or destination is different */
449: ip6stat.ip6s_forward_cachemiss++;
450: RTFREE(ip6_forward_rt.ro_rt);
451: ip6_forward_rt.ro_rt = 0;
452: }
453:
454: bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
455: ip6_forward_rt.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
456: ip6_forward_rt.ro_dst.sin6_family = AF_INET6;
457: ip6_forward_rt.ro_dst.sin6_addr = ip6->ip6_dst;
458: ip6_forward_rtableid = rtableid;
459:
460: rtalloc_mpath((struct route *)&ip6_forward_rt,
461: &ip6->ip6_src.s6_addr32[0], rtableid);
462: }
463:
464: #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
465:
466: /*
467: * Accept the packet if the forwarding interface to the destination
468: * according to the routing table is the loopback interface,
469: * unless the associated route has a gateway.
470: * Note that this approach causes to accept a packet if there is a
471: * route to the loopback interface for the destination of the packet.
472: * But we think it's even useful in some situations, e.g. when using
473: * a special daemon which wants to intercept the packet.
474: */
475: if (ip6_forward_rt.ro_rt &&
476: (ip6_forward_rt.ro_rt->rt_flags &
477: (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
478: #if 0
479: /*
480: * The check below is redundant since the comparison of
481: * the destination and the key of the rtentry has
482: * already done through looking up the routing table.
483: */
484: IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
485: &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) &&
486: #endif
487: ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
488: struct in6_ifaddr *ia6 =
489: (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
490: if (ia6->ia6_flags & IN6_IFF_ANYCAST)
491: m->m_flags |= M_ANYCAST6;
492: /*
493: * packets to a tentative, duplicated, or somehow invalid
494: * address must not be accepted.
495: */
496: if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
497: /* this address is ready */
498: ours = 1;
499: deliverifp = ia6->ia_ifp; /* correct? */
500: goto hbhcheck;
501: } else {
502: /* address is not ready, so discard the packet. */
503: nd6log((LOG_INFO,
504: "ip6_input: packet to an unready address %s->%s\n",
505: ip6_sprintf(&ip6->ip6_src),
506: ip6_sprintf(&ip6->ip6_dst)));
507:
508: goto bad;
509: }
510: }
511:
512: /*
513: * FAITH (Firewall Aided Internet Translator)
514: */
515: #if defined(NFAITH) && 0 < NFAITH
516: if (ip6_keepfaith) {
517: if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
518: && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
519: /* XXX do we need more sanity checks? */
520: ours = 1;
521: deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /*faith*/
522: goto hbhcheck;
523: }
524: }
525: #endif
526:
527: #if 0
528: {
529: /*
530: * Last resort: check in6_ifaddr for incoming interface.
531: * The code is here until I update the "goto ours hack" code above
532: * working right.
533: */
534: struct ifaddr *ifa;
535: TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) {
536: if (ifa->ifa_addr == NULL)
537: continue; /* just for safety */
538: if (ifa->ifa_addr->sa_family != AF_INET6)
539: continue;
540: if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ip6->ip6_dst)) {
541: ours = 1;
542: deliverifp = ifa->ifa_ifp;
543: goto hbhcheck;
544: }
545: }
546: }
547: #endif
548:
549: #if NCARP > 0
550: if (m->m_pkthdr.rcvif->if_type == IFT_CARP &&
551: m->m_pkthdr.rcvif->if_flags & IFF_LINK0 &&
552: ip6->ip6_nxt == IPPROTO_ICMPV6 &&
553: carp_lsdrop(m, AF_INET6, ip6->ip6_src.s6_addr32,
554: ip6->ip6_dst.s6_addr32))
555: goto bad;
556: #endif
557: /*
558: * Now there is no reason to process the packet if it's not our own
559: * and we're not a router.
560: */
561: if (!ip6_forwarding) {
562: ip6stat.ip6s_cantforward++;
563: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
564: goto bad;
565: }
566:
567: hbhcheck:
568: /*
569: * Process Hop-by-Hop options header if it's contained.
570: * m may be modified in ip6_hopopts_input().
571: * If a JumboPayload option is included, plen will also be modified.
572: */
573: plen = (u_int32_t)ntohs(ip6->ip6_plen);
574: if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
575: struct ip6_hbh *hbh;
576:
577: if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
578: #if 0 /*touches NULL pointer*/
579: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
580: #endif
581: return; /* m have already been freed */
582: }
583:
584: /* adjust pointer */
585: ip6 = mtod(m, struct ip6_hdr *);
586:
587: /*
588: * if the payload length field is 0 and the next header field
589: * indicates Hop-by-Hop Options header, then a Jumbo Payload
590: * option MUST be included.
591: */
592: if (ip6->ip6_plen == 0 && plen == 0) {
593: /*
594: * Note that if a valid jumbo payload option is
595: * contained, ip6_hoptops_input() must set a valid
596: * (non-zero) payload length to the variable plen.
597: */
598: ip6stat.ip6s_badoptions++;
599: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
600: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
601: icmp6_error(m, ICMP6_PARAM_PROB,
602: ICMP6_PARAMPROB_HEADER,
603: (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
604: return;
605: }
606: IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
607: sizeof(struct ip6_hbh));
608: if (hbh == NULL) {
609: ip6stat.ip6s_tooshort++;
610: return;
611: }
612: nxt = hbh->ip6h_nxt;
613:
614: /*
615: * accept the packet if a router alert option is included
616: * and we act as an IPv6 router.
617: */
618: if (rtalert != ~0 && ip6_forwarding)
619: ours = 1;
620: } else
621: nxt = ip6->ip6_nxt;
622:
623: /*
624: * Check that the amount of data in the buffers
625: * is as at least much as the IPv6 header would have us expect.
626: * Trim mbufs if longer than we expect.
627: * Drop packet if shorter than we expect.
628: */
629: if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
630: ip6stat.ip6s_tooshort++;
631: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
632: goto bad;
633: }
634: if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
635: if (m->m_len == m->m_pkthdr.len) {
636: m->m_len = sizeof(struct ip6_hdr) + plen;
637: m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
638: } else
639: m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
640: }
641:
642: /*
643: * Forward if desirable.
644: */
645: if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
646: /*
647: * If we are acting as a multicast router, all
648: * incoming multicast packets are passed to the
649: * kernel-level multicast forwarding function.
650: * The packet is returned (relatively) intact; if
651: * ip6_mforward() returns a non-zero value, the packet
652: * must be discarded, else it may be accepted below.
653: */
654: #ifdef MROUTING
655: if (ip6_mforwarding && ip6_mrouter &&
656: ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
657: ip6stat.ip6s_cantforward++;
658: m_freem(m);
659: return;
660: }
661: #endif
662: if (!ours) {
663: m_freem(m);
664: return;
665: }
666: } else if (!ours) {
667: ip6_forward(m, srcrt);
668: return;
669: }
670:
671: ip6 = mtod(m, struct ip6_hdr *);
672:
673: /*
674: * Malicious party may be able to use IPv4 mapped addr to confuse
675: * tcp/udp stack and bypass security checks (act as if it was from
676: * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
677: *
678: * For SIIT end node behavior, you may want to disable the check.
679: * However, you will become vulnerable to attacks using IPv4 mapped
680: * source.
681: */
682: if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
683: IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
684: ip6stat.ip6s_badscope++;
685: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
686: goto bad;
687: }
688:
689: /*
690: * Tell launch routine the next header
691: */
692: ip6stat.ip6s_delivered++;
693: in6_ifstat_inc(deliverifp, ifs6_in_deliver);
694: nest = 0;
695:
696: while (nxt != IPPROTO_DONE) {
697: if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
698: ip6stat.ip6s_toomanyhdr++;
699: goto bad;
700: }
701:
702: /*
703: * protection against faulty packet - there should be
704: * more sanity checks in header chain processing.
705: */
706: if (m->m_pkthdr.len < off) {
707: ip6stat.ip6s_tooshort++;
708: in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
709: goto bad;
710: }
711:
712: nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
713: }
714: return;
715: bad:
716: m_freem(m);
717: }
718:
719:
720: /* scan packet for RH0 routing header. Mostly stolen from pf.c:pf_test6() */
721: int
722: ip6_check_rh0hdr(struct mbuf *m)
723: {
724: struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
725: struct ip6_rthdr rthdr;
726: struct ip6_ext opt6;
727: u_int8_t proto = ip6->ip6_nxt;
728: int done = 0, lim, off, rh_cnt = 0;
729:
730: off = ((caddr_t)ip6 - m->m_data) + sizeof(struct ip6_hdr);
731: lim = min(m->m_pkthdr.len, ntohs(ip6->ip6_plen) + sizeof(*ip6));
732: do {
733: switch (proto) {
734: case IPPROTO_ROUTING:
735: if (rh_cnt++) {
736: /* more then one rh header present */
737: return (1);
738: }
739:
740: if (off + sizeof(opt6) > lim) {
741: /* packet to short to make sense */
742: return (1);
743: }
744:
745: m_copydata(m, off, sizeof(rthdr), (caddr_t)&rthdr);
746:
747: if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0)
748: return (1);
749:
750: off += (rthdr.ip6r_len + 1) * 8;
751: proto = rthdr.ip6r_nxt;
752: break;
753: case IPPROTO_AH:
754: case IPPROTO_HOPOPTS:
755: case IPPROTO_DSTOPTS:
756: /* get next header and header length */
757: if (off + sizeof(opt6) > lim) {
758: /*
759: * Packet to short to make sense, we could
760: * reject the packet but as a router we
761: * should not do that so forward it.
762: */
763: return (0);
764: }
765:
766: m_copydata(m, off, sizeof(opt6), (caddr_t)&opt6);
767:
768: if (proto == IPPROTO_AH)
769: off += (opt6.ip6e_len + 2) * 4;
770: else
771: off += (opt6.ip6e_len + 1) * 8;
772: proto = opt6.ip6e_nxt;
773: break;
774: case IPPROTO_FRAGMENT:
775: default:
776: /* end of header stack */
777: done = 1;
778: break;
779: }
780: } while (!done);
781:
782: return (0);
783: }
784:
785: /*
786: * Hop-by-Hop options header processing. If a valid jumbo payload option is
787: * included, the real payload length will be stored in plenp.
788: */
789: static int
790: ip6_hopopts_input(plenp, rtalertp, mp, offp)
791: u_int32_t *plenp;
792: u_int32_t *rtalertp; /* XXX: should be stored more smart way */
793: struct mbuf **mp;
794: int *offp;
795: {
796: struct mbuf *m = *mp;
797: int off = *offp, hbhlen;
798: struct ip6_hbh *hbh;
799: u_int8_t *opt;
800:
801: /* validation of the length of the header */
802: IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
803: sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
804: if (hbh == NULL) {
805: ip6stat.ip6s_tooshort++;
806: return -1;
807: }
808: hbhlen = (hbh->ip6h_len + 1) << 3;
809: IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
810: hbhlen);
811: if (hbh == NULL) {
812: ip6stat.ip6s_tooshort++;
813: return -1;
814: }
815: off += hbhlen;
816: hbhlen -= sizeof(struct ip6_hbh);
817: opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
818:
819: if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
820: hbhlen, rtalertp, plenp) < 0)
821: return (-1);
822:
823: *offp = off;
824: *mp = m;
825: return (0);
826: }
827:
828: /*
829: * Search header for all Hop-by-hop options and process each option.
830: * This function is separate from ip6_hopopts_input() in order to
831: * handle a case where the sending node itself process its hop-by-hop
832: * options header. In such a case, the function is called from ip6_output().
833: *
834: * The function assumes that hbh header is located right after the IPv6 header
835: * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
836: * opthead + hbhlen is located in continuous memory region.
837: */
838: int
839: ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp)
840: struct mbuf *m;
841: u_int8_t *opthead;
842: int hbhlen;
843: u_int32_t *rtalertp;
844: u_int32_t *plenp;
845: {
846: struct ip6_hdr *ip6;
847: int optlen = 0;
848: u_int8_t *opt = opthead;
849: u_int16_t rtalert_val;
850: u_int32_t jumboplen;
851: const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
852:
853: for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
854: switch (*opt) {
855: case IP6OPT_PAD1:
856: optlen = 1;
857: break;
858: case IP6OPT_PADN:
859: if (hbhlen < IP6OPT_MINLEN) {
860: ip6stat.ip6s_toosmall++;
861: goto bad;
862: }
863: optlen = *(opt + 1) + 2;
864: break;
865: case IP6OPT_ROUTER_ALERT:
866: /* XXX may need check for alignment */
867: if (hbhlen < IP6OPT_RTALERT_LEN) {
868: ip6stat.ip6s_toosmall++;
869: goto bad;
870: }
871: if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
872: /* XXX stat */
873: icmp6_error(m, ICMP6_PARAM_PROB,
874: ICMP6_PARAMPROB_HEADER,
875: erroff + opt + 1 - opthead);
876: return (-1);
877: }
878: optlen = IP6OPT_RTALERT_LEN;
879: bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
880: *rtalertp = ntohs(rtalert_val);
881: break;
882: case IP6OPT_JUMBO:
883: /* XXX may need check for alignment */
884: if (hbhlen < IP6OPT_JUMBO_LEN) {
885: ip6stat.ip6s_toosmall++;
886: goto bad;
887: }
888: if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
889: /* XXX stat */
890: icmp6_error(m, ICMP6_PARAM_PROB,
891: ICMP6_PARAMPROB_HEADER,
892: erroff + opt + 1 - opthead);
893: return (-1);
894: }
895: optlen = IP6OPT_JUMBO_LEN;
896:
897: /*
898: * IPv6 packets that have non 0 payload length
899: * must not contain a jumbo payload option.
900: */
901: ip6 = mtod(m, struct ip6_hdr *);
902: if (ip6->ip6_plen) {
903: ip6stat.ip6s_badoptions++;
904: icmp6_error(m, ICMP6_PARAM_PROB,
905: ICMP6_PARAMPROB_HEADER,
906: erroff + opt - opthead);
907: return (-1);
908: }
909:
910: /*
911: * We may see jumbolen in unaligned location, so
912: * we'd need to perform bcopy().
913: */
914: bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
915: jumboplen = (u_int32_t)htonl(jumboplen);
916:
917: #if 1
918: /*
919: * if there are multiple jumbo payload options,
920: * *plenp will be non-zero and the packet will be
921: * rejected.
922: * the behavior may need some debate in ipngwg -
923: * multiple options does not make sense, however,
924: * there's no explicit mention in specification.
925: */
926: if (*plenp != 0) {
927: ip6stat.ip6s_badoptions++;
928: icmp6_error(m, ICMP6_PARAM_PROB,
929: ICMP6_PARAMPROB_HEADER,
930: erroff + opt + 2 - opthead);
931: return (-1);
932: }
933: #endif
934:
935: /*
936: * jumbo payload length must be larger than 65535.
937: */
938: if (jumboplen <= IPV6_MAXPACKET) {
939: ip6stat.ip6s_badoptions++;
940: icmp6_error(m, ICMP6_PARAM_PROB,
941: ICMP6_PARAMPROB_HEADER,
942: erroff + opt + 2 - opthead);
943: return (-1);
944: }
945: *plenp = jumboplen;
946:
947: break;
948: default: /* unknown option */
949: if (hbhlen < IP6OPT_MINLEN) {
950: ip6stat.ip6s_toosmall++;
951: goto bad;
952: }
953: optlen = ip6_unknown_opt(opt, m,
954: erroff + opt - opthead);
955: if (optlen == -1)
956: return (-1);
957: optlen += 2;
958: break;
959: }
960: }
961:
962: return (0);
963:
964: bad:
965: m_freem(m);
966: return (-1);
967: }
968:
969: /*
970: * Unknown option processing.
971: * The third argument `off' is the offset from the IPv6 header to the option,
972: * which is necessary if the IPv6 header the and option header and IPv6 header
973: * is not continuous in order to return an ICMPv6 error.
974: */
975: int
976: ip6_unknown_opt(optp, m, off)
977: u_int8_t *optp;
978: struct mbuf *m;
979: int off;
980: {
981: struct ip6_hdr *ip6;
982:
983: switch (IP6OPT_TYPE(*optp)) {
984: case IP6OPT_TYPE_SKIP: /* ignore the option */
985: return ((int)*(optp + 1));
986: case IP6OPT_TYPE_DISCARD: /* silently discard */
987: m_freem(m);
988: return (-1);
989: case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
990: ip6stat.ip6s_badoptions++;
991: icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
992: return (-1);
993: case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
994: ip6stat.ip6s_badoptions++;
995: ip6 = mtod(m, struct ip6_hdr *);
996: if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
997: (m->m_flags & (M_BCAST|M_MCAST)))
998: m_freem(m);
999: else
1000: icmp6_error(m, ICMP6_PARAM_PROB,
1001: ICMP6_PARAMPROB_OPTION, off);
1002: return (-1);
1003: }
1004:
1005: m_freem(m); /* XXX: NOTREACHED */
1006: return (-1);
1007: }
1008:
1009: /*
1010: * Create the "control" list for this pcb.
1011: *
1012: * The routine will be called from upper layer handlers like tcp6_input().
1013: * Thus the routine assumes that the caller (tcp6_input) have already
1014: * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1015: * very first mbuf on the mbuf chain.
1016: * We may want to add some infinite loop prevention or sanity checks for safety.
1017: * (This applies only when you are using KAME mbuf chain restriction, i.e.
1018: * you are using IP6_EXTHDR_CHECK() not m_pulldown())
1019: */
1020: void
1021: ip6_savecontrol(in6p, m, mp)
1022: struct inpcb *in6p;
1023: struct mbuf *m;
1024: struct mbuf **mp;
1025: {
1026: #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y))
1027: # define in6p_flags inp_flags
1028: struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1029:
1030: #ifdef SO_TIMESTAMP
1031: if (in6p->inp_socket->so_options & SO_TIMESTAMP) {
1032: struct timeval tv;
1033:
1034: microtime(&tv);
1035: *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1036: SCM_TIMESTAMP, SOL_SOCKET);
1037: if (*mp)
1038: mp = &(*mp)->m_next;
1039: }
1040: #endif
1041:
1042: /* RFC 2292 sec. 5 */
1043: if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) {
1044: struct in6_pktinfo pi6;
1045: bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1046: if (IN6_IS_SCOPE_EMBED(&pi6.ipi6_addr))
1047: pi6.ipi6_addr.s6_addr16[1] = 0;
1048: pi6.ipi6_ifindex =
1049: (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1050: *mp = sbcreatecontrol((caddr_t) &pi6,
1051: sizeof(struct in6_pktinfo),
1052: IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1053: if (*mp)
1054: mp = &(*mp)->m_next;
1055: }
1056:
1057: if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) {
1058: int hlim = ip6->ip6_hlim & 0xff;
1059: *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
1060: IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6);
1061: if (*mp)
1062: mp = &(*mp)->m_next;
1063: }
1064:
1065: if ((in6p->in6p_flags & IN6P_TCLASS) != 0) {
1066: u_int32_t flowinfo;
1067: int tclass;
1068:
1069: flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1070: flowinfo >>= 20;
1071:
1072: tclass = flowinfo & 0xff;
1073: *mp = sbcreatecontrol((caddr_t)&tclass, sizeof(tclass),
1074: IPV6_TCLASS, IPPROTO_IPV6);
1075: if (*mp)
1076: mp = &(*mp)->m_next;
1077: }
1078:
1079: /*
1080: * IPV6_HOPOPTS socket option. Recall that we required super-user
1081: * privilege for the option (see ip6_ctloutput), but it might be too
1082: * strict, since there might be some hop-by-hop options which can be
1083: * returned to normal user.
1084: * See also RFC 2292 section 6 (or RFC 3542 section 8).
1085: */
1086: if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) {
1087: /*
1088: * Check if a hop-by-hop options header is contatined in the
1089: * received packet, and if so, store the options as ancillary
1090: * data. Note that a hop-by-hop options header must be
1091: * just after the IPv6 header, which is assured through the
1092: * IPv6 input processing.
1093: */
1094: struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1095: if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1096: struct ip6_hbh *hbh;
1097: int hbhlen = 0;
1098: struct mbuf *ext;
1099:
1100: ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1101: ip6->ip6_nxt);
1102: if (ext == NULL) {
1103: ip6stat.ip6s_tooshort++;
1104: return;
1105: }
1106: hbh = mtod(ext, struct ip6_hbh *);
1107: hbhlen = (hbh->ip6h_len + 1) << 3;
1108: if (hbhlen != ext->m_len) {
1109: m_freem(ext);
1110: ip6stat.ip6s_tooshort++;
1111: return;
1112: }
1113:
1114: /*
1115: * XXX: We copy the whole header even if a
1116: * jumbo payload option is included, the option which
1117: * is to be removed before returning according to
1118: * RFC2292.
1119: * Note: this constraint is removed in RFC3542.
1120: */
1121: *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1122: IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1123: IPPROTO_IPV6);
1124: if (*mp)
1125: mp = &(*mp)->m_next;
1126: m_freem(ext);
1127: }
1128: }
1129:
1130: /* IPV6_DSTOPTS and IPV6_RTHDR socket options */
1131: if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1132: struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1133: int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1134:
1135: /*
1136: * Search for destination options headers or routing
1137: * header(s) through the header chain, and stores each
1138: * header as ancillary data.
1139: * Note that the order of the headers remains in
1140: * the chain of ancillary data.
1141: */
1142: while (1) { /* is explicit loop prevention necessary? */
1143: struct ip6_ext *ip6e = NULL;
1144: int elen;
1145: struct mbuf *ext = NULL;
1146:
1147: /*
1148: * if it is not an extension header, don't try to
1149: * pull it from the chain.
1150: */
1151: switch (nxt) {
1152: case IPPROTO_DSTOPTS:
1153: case IPPROTO_ROUTING:
1154: case IPPROTO_HOPOPTS:
1155: case IPPROTO_AH: /* is it possible? */
1156: break;
1157: default:
1158: goto loopend;
1159: }
1160:
1161: ext = ip6_pullexthdr(m, off, nxt);
1162: if (ext == NULL) {
1163: ip6stat.ip6s_tooshort++;
1164: return;
1165: }
1166: ip6e = mtod(ext, struct ip6_ext *);
1167: if (nxt == IPPROTO_AH)
1168: elen = (ip6e->ip6e_len + 2) << 2;
1169: else
1170: elen = (ip6e->ip6e_len + 1) << 3;
1171: if (elen != ext->m_len) {
1172: m_freem(ext);
1173: ip6stat.ip6s_tooshort++;
1174: return;
1175: }
1176:
1177: switch (nxt) {
1178: case IPPROTO_DSTOPTS:
1179: if (!(in6p->in6p_flags & IN6P_DSTOPTS))
1180: break;
1181:
1182: *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1183: IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1184: IPPROTO_IPV6);
1185: if (*mp)
1186: mp = &(*mp)->m_next;
1187: break;
1188:
1189: case IPPROTO_ROUTING:
1190: if (!(in6p->in6p_flags & IN6P_RTHDR))
1191: break;
1192:
1193: *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1194: IS2292(IPV6_2292RTHDR, IPV6_RTHDR),
1195: IPPROTO_IPV6);
1196: if (*mp)
1197: mp = &(*mp)->m_next;
1198: break;
1199:
1200: case IPPROTO_HOPOPTS:
1201: case IPPROTO_AH: /* is it possible? */
1202: break;
1203:
1204: default:
1205: /*
1206: * other cases have been filtered in the above.
1207: * none will visit this case. here we supply
1208: * the code just in case (nxt overwritten or
1209: * other cases).
1210: */
1211: m_freem(ext);
1212: goto loopend;
1213:
1214: }
1215:
1216: /* proceed with the next header. */
1217: off += elen;
1218: nxt = ip6e->ip6e_nxt;
1219: ip6e = NULL;
1220: m_freem(ext);
1221: ext = NULL;
1222: }
1223: loopend:
1224: ;
1225: }
1226: # undef in6p_flags
1227: }
1228:
1229: /*
1230: * pull single extension header from mbuf chain. returns single mbuf that
1231: * contains the result, or NULL on error.
1232: */
1233: static struct mbuf *
1234: ip6_pullexthdr(m, off, nxt)
1235: struct mbuf *m;
1236: size_t off;
1237: int nxt;
1238: {
1239: struct ip6_ext ip6e;
1240: size_t elen;
1241: struct mbuf *n;
1242:
1243: #ifdef DIAGNOSTIC
1244: switch (nxt) {
1245: case IPPROTO_DSTOPTS:
1246: case IPPROTO_ROUTING:
1247: case IPPROTO_HOPOPTS:
1248: case IPPROTO_AH: /* is it possible? */
1249: break;
1250: default:
1251: printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1252: }
1253: #endif
1254:
1255: m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1256: if (nxt == IPPROTO_AH)
1257: elen = (ip6e.ip6e_len + 2) << 2;
1258: else
1259: elen = (ip6e.ip6e_len + 1) << 3;
1260:
1261: MGET(n, M_DONTWAIT, MT_DATA);
1262: if (n && elen >= MLEN) {
1263: MCLGET(n, M_DONTWAIT);
1264: if ((n->m_flags & M_EXT) == 0) {
1265: m_free(n);
1266: n = NULL;
1267: }
1268: }
1269: if (!n)
1270: return NULL;
1271:
1272: n->m_len = 0;
1273: if (elen >= M_TRAILINGSPACE(n)) {
1274: m_free(n);
1275: return NULL;
1276: }
1277:
1278: m_copydata(m, off, elen, mtod(n, caddr_t));
1279: n->m_len = elen;
1280: return n;
1281: }
1282:
1283: /*
1284: * Get pointer to the previous header followed by the header
1285: * currently processed.
1286: * XXX: This function supposes that
1287: * M includes all headers,
1288: * the next header field and the header length field of each header
1289: * are valid, and
1290: * the sum of each header length equals to OFF.
1291: * Because of these assumptions, this function must be called very
1292: * carefully. Moreover, it will not be used in the near future when
1293: * we develop `neater' mechanism to process extension headers.
1294: */
1295: u_int8_t *
1296: ip6_get_prevhdr(m, off)
1297: struct mbuf *m;
1298: int off;
1299: {
1300: struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1301:
1302: if (off == sizeof(struct ip6_hdr))
1303: return (&ip6->ip6_nxt);
1304: else {
1305: int len, nxt;
1306: struct ip6_ext *ip6e = NULL;
1307:
1308: nxt = ip6->ip6_nxt;
1309: len = sizeof(struct ip6_hdr);
1310: while (len < off) {
1311: ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1312:
1313: switch (nxt) {
1314: case IPPROTO_FRAGMENT:
1315: len += sizeof(struct ip6_frag);
1316: break;
1317: case IPPROTO_AH:
1318: len += (ip6e->ip6e_len + 2) << 2;
1319: break;
1320: default:
1321: len += (ip6e->ip6e_len + 1) << 3;
1322: break;
1323: }
1324: nxt = ip6e->ip6e_nxt;
1325: }
1326: if (ip6e)
1327: return (&ip6e->ip6e_nxt);
1328: else
1329: return NULL;
1330: }
1331: }
1332:
1333: /*
1334: * get next header offset. m will be retained.
1335: */
1336: int
1337: ip6_nexthdr(m, off, proto, nxtp)
1338: struct mbuf *m;
1339: int off;
1340: int proto;
1341: int *nxtp;
1342: {
1343: struct ip6_hdr ip6;
1344: struct ip6_ext ip6e;
1345: struct ip6_frag fh;
1346:
1347: /* just in case */
1348: if (m == NULL)
1349: panic("ip6_nexthdr: m == NULL");
1350: if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1351: return -1;
1352:
1353: switch (proto) {
1354: case IPPROTO_IPV6:
1355: if (m->m_pkthdr.len < off + sizeof(ip6))
1356: return -1;
1357: m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1358: if (nxtp)
1359: *nxtp = ip6.ip6_nxt;
1360: off += sizeof(ip6);
1361: return off;
1362:
1363: case IPPROTO_FRAGMENT:
1364: /*
1365: * terminate parsing if it is not the first fragment,
1366: * it does not make sense to parse through it.
1367: */
1368: if (m->m_pkthdr.len < off + sizeof(fh))
1369: return -1;
1370: m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1371: if ((fh.ip6f_offlg & IP6F_OFF_MASK) != 0)
1372: return -1;
1373: if (nxtp)
1374: *nxtp = fh.ip6f_nxt;
1375: off += sizeof(struct ip6_frag);
1376: return off;
1377:
1378: case IPPROTO_AH:
1379: if (m->m_pkthdr.len < off + sizeof(ip6e))
1380: return -1;
1381: m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1382: if (nxtp)
1383: *nxtp = ip6e.ip6e_nxt;
1384: off += (ip6e.ip6e_len + 2) << 2;
1385: if (m->m_pkthdr.len < off)
1386: return -1;
1387: return off;
1388:
1389: case IPPROTO_HOPOPTS:
1390: case IPPROTO_ROUTING:
1391: case IPPROTO_DSTOPTS:
1392: if (m->m_pkthdr.len < off + sizeof(ip6e))
1393: return -1;
1394: m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1395: if (nxtp)
1396: *nxtp = ip6e.ip6e_nxt;
1397: off += (ip6e.ip6e_len + 1) << 3;
1398: if (m->m_pkthdr.len < off)
1399: return -1;
1400: return off;
1401:
1402: case IPPROTO_NONE:
1403: case IPPROTO_ESP:
1404: case IPPROTO_IPCOMP:
1405: /* give up */
1406: return -1;
1407:
1408: default:
1409: return -1;
1410: }
1411:
1412: return -1;
1413: }
1414:
1415: /*
1416: * get offset for the last header in the chain. m will be kept untainted.
1417: */
1418: int
1419: ip6_lasthdr(m, off, proto, nxtp)
1420: struct mbuf *m;
1421: int off;
1422: int proto;
1423: int *nxtp;
1424: {
1425: int newoff;
1426: int nxt;
1427:
1428: if (!nxtp) {
1429: nxt = -1;
1430: nxtp = &nxt;
1431: }
1432: while (1) {
1433: newoff = ip6_nexthdr(m, off, proto, nxtp);
1434: if (newoff < 0)
1435: return off;
1436: else if (newoff < off)
1437: return -1; /* invalid */
1438: else if (newoff == off)
1439: return newoff;
1440:
1441: off = newoff;
1442: proto = *nxtp;
1443: }
1444: }
1445:
1446: /*
1447: * System control for IP6
1448: */
1449:
1450: u_char inet6ctlerrmap[PRC_NCMDS] = {
1451: 0, 0, 0, 0,
1452: 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1453: EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1454: EMSGSIZE, EHOSTUNREACH, 0, 0,
1455: 0, 0, 0, 0,
1456: ENOPROTOOPT
1457: };
1458:
1459: #include <uvm/uvm_extern.h>
1460: #include <sys/sysctl.h>
1461:
1462: int *ipv6ctl_vars[IPV6CTL_MAXID] = IPV6CTL_VARS;
1463:
1464: int
1465: ip6_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1466: int *name;
1467: u_int namelen;
1468: void *oldp;
1469: size_t *oldlenp;
1470: void *newp;
1471: size_t newlen;
1472: {
1473: /* All sysctl names at this level are terminal. */
1474: if (namelen != 1)
1475: return ENOTDIR;
1476:
1477: switch (name[0]) {
1478: case IPV6CTL_KAME_VERSION:
1479: return sysctl_rdstring(oldp, oldlenp, newp, __KAME_VERSION);
1480: case IPV6CTL_V6ONLY:
1481: return sysctl_rdint(oldp, oldlenp, newp, ip6_v6only);
1482: default:
1483: if (name[0] < IPV6CTL_MAXID)
1484: return (sysctl_int_arr(ipv6ctl_vars, name, namelen,
1485: oldp, oldlenp, newp, newlen));
1486: return (EOPNOTSUPP);
1487: }
1488: /* NOTREACHED */
1489: }