]> CyberLeo.Net >> Repos - FreeBSD/FreeBSD.git/blob - sys/netinet6/ip6_output.c
IFC @ r242684
[FreeBSD/FreeBSD.git] / sys / netinet6 / ip6_output.c
1 /*-
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
30  */
31
32 /*-
33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
34  *      The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 4. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
61  */
62
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_ipfw.h"
69 #include "opt_ipsec.h"
70 #include "opt_sctp.h"
71 #include "opt_route.h"
72
73 #include <sys/param.h>
74 #include <sys/kernel.h>
75 #include <sys/malloc.h>
76 #include <sys/mbuf.h>
77 #include <sys/errno.h>
78 #include <sys/priv.h>
79 #include <sys/proc.h>
80 #include <sys/protosw.h>
81 #include <sys/socket.h>
82 #include <sys/socketvar.h>
83 #include <sys/syslog.h>
84 #include <sys/ucred.h>
85
86 #include <machine/in_cksum.h>
87
88 #include <net/if.h>
89 #include <net/netisr.h>
90 #include <net/route.h>
91 #include <net/pfil.h>
92 #include <net/vnet.h>
93
94 #include <netinet/in.h>
95 #include <netinet/in_var.h>
96 #include <netinet/ip_var.h>
97 #include <netinet6/in6_var.h>
98 #include <netinet/ip6.h>
99 #include <netinet/icmp6.h>
100 #include <netinet6/ip6_var.h>
101 #include <netinet/in_pcb.h>
102 #include <netinet/tcp_var.h>
103 #include <netinet6/nd6.h>
104
105 #ifdef IPSEC
106 #include <netipsec/ipsec.h>
107 #include <netipsec/ipsec6.h>
108 #include <netipsec/key.h>
109 #include <netinet6/ip6_ipsec.h>
110 #endif /* IPSEC */
111 #ifdef SCTP
112 #include <netinet/sctp.h>
113 #include <netinet/sctp_crc32.h>
114 #endif
115
116 #include <netinet6/ip6protosw.h>
117 #include <netinet6/scope6_var.h>
118
119 #ifdef FLOWTABLE
120 #include <net/flowtable.h>
121 #endif
122
123 extern int in6_mcast_loop;
124
125 struct ip6_exthdrs {
126         struct mbuf *ip6e_ip6;
127         struct mbuf *ip6e_hbh;
128         struct mbuf *ip6e_dest1;
129         struct mbuf *ip6e_rthdr;
130         struct mbuf *ip6e_dest2;
131 };
132
133 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
134                            struct ucred *, int);
135 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
136         struct socket *, struct sockopt *);
137 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
138 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
139         struct ucred *, int, int, int);
140
141 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
142 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
143         struct ip6_frag **);
144 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
145 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
146 static int ip6_getpmtu(struct route_in6 *, struct route_in6 *,
147         struct ifnet *, struct in6_addr *, u_long *, int *, u_int);
148 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
149
150
151 /*
152  * Make an extension header from option data.  hp is the source, and
153  * mp is the destination.
154  */
155 #define MAKE_EXTHDR(hp, mp)                                             \
156     do {                                                                \
157         if (hp) {                                                       \
158                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
159                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
160                     ((eh)->ip6e_len + 1) << 3);                         \
161                 if (error)                                              \
162                         goto freehdrs;                                  \
163         }                                                               \
164     } while (/*CONSTCOND*/ 0)
165
166 /*
167  * Form a chain of extension headers.
168  * m is the extension header mbuf
169  * mp is the previous mbuf in the chain
170  * p is the next header
171  * i is the type of option.
172  */
173 #define MAKE_CHAIN(m, mp, p, i)\
174     do {\
175         if (m) {\
176                 if (!hdrsplit) \
177                         panic("assumption failed: hdr not split"); \
178                 *mtod((m), u_char *) = *(p);\
179                 *(p) = (i);\
180                 p = mtod((m), u_char *);\
181                 (m)->m_next = (mp)->m_next;\
182                 (mp)->m_next = (m);\
183                 (mp) = (m);\
184         }\
185     } while (/*CONSTCOND*/ 0)
186
187 static void
188 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
189 {
190         u_short csum;
191
192         csum = in_cksum_skip(m, offset + plen, offset);
193         if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
194                 csum = 0xffff;
195         offset += m->m_pkthdr.csum_data;        /* checksum offset */
196
197         if (offset + sizeof(u_short) > m->m_len) {
198                 printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
199                     "csum_flags=0x%04x\n", __func__, m->m_len, plen, offset,
200                     m->m_pkthdr.csum_flags);
201                 /*
202                  * XXX this should not happen, but if it does, the correct
203                  * behavior may be to insert the checksum in the appropriate
204                  * next mbuf in the chain.
205                  */
206                 return;
207         }
208         *(u_short *)(m->m_data + offset) = csum;
209 }
210
211 /*
212  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
213  * header (with pri, len, nxt, hlim, src, dst).
214  * This function may modify ver and hlim only.
215  * The mbuf chain containing the packet will be freed.
216  * The mbuf opt, if present, will not be freed.
217  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
218  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
219  * then result of route lookup is stored in ro->ro_rt.
220  *
221  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
222  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
223  * which is rt_rmx.rmx_mtu.
224  *
225  * ifpp - XXX: just for statistics
226  */
227 int
228 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
229     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
230     struct ifnet **ifpp, struct inpcb *inp)
231 {
232         struct ip6_hdr *ip6, *mhip6;
233         struct ifnet *ifp, *origifp;
234         struct mbuf *m = m0;
235         struct mbuf *mprev = NULL;
236         int hlen, tlen, len, off;
237         struct route_in6 ip6route;
238         struct rtentry *rt = NULL;
239         struct sockaddr_in6 *dst, src_sa, dst_sa;
240         struct in6_addr odst;
241         int error = 0;
242         struct in6_ifaddr *ia = NULL;
243         u_long mtu;
244         int alwaysfrag, dontfrag;
245         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
246         struct ip6_exthdrs exthdrs;
247         struct in6_addr finaldst, src0, dst0;
248         u_int32_t zone;
249         struct route_in6 *ro_pmtu = NULL;
250         int hdrsplit = 0;
251         int needipsec = 0;
252         int sw_csum, tso;
253 #ifdef IPSEC
254         struct ipsec_output_state state;
255         struct ip6_rthdr *rh = NULL;
256         int needipsectun = 0;
257         int segleft_org = 0;
258         struct secpolicy *sp = NULL;
259 #endif /* IPSEC */
260         struct m_tag *fwd_tag;
261
262         ip6 = mtod(m, struct ip6_hdr *);
263         if (ip6 == NULL) {
264                 printf ("ip6 is NULL");
265                 goto bad;
266         }
267
268         if (inp != NULL)
269                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
270
271         finaldst = ip6->ip6_dst;
272         bzero(&exthdrs, sizeof(exthdrs));
273         if (opt) {
274                 /* Hop-by-Hop options header */
275                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
276                 /* Destination options header(1st part) */
277                 if (opt->ip6po_rthdr) {
278                         /*
279                          * Destination options header(1st part)
280                          * This only makes sense with a routing header.
281                          * See Section 9.2 of RFC 3542.
282                          * Disabling this part just for MIP6 convenience is
283                          * a bad idea.  We need to think carefully about a
284                          * way to make the advanced API coexist with MIP6
285                          * options, which might automatically be inserted in
286                          * the kernel.
287                          */
288                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
289                 }
290                 /* Routing header */
291                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
292                 /* Destination options header(2nd part) */
293                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
294         }
295
296 #ifdef IPSEC
297         /*
298          * IPSec checking which handles several cases.
299          * FAST IPSEC: We re-injected the packet.
300          */
301         switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
302         {
303         case 1:                 /* Bad packet */
304                 goto freehdrs;
305         case -1:                /* Do IPSec */
306                 needipsec = 1;
307                 /*
308                  * Do delayed checksums now, as we may send before returning.
309                  */
310                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
311                         plen = m->m_pkthdr.len - sizeof(*ip6);
312                         in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
313                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
314                 }
315 #ifdef SCTP
316                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
317                         sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
318                         m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
319                 }
320 #endif
321         case 0:                 /* No IPSec */
322         default:
323                 break;
324         }
325 #endif /* IPSEC */
326
327         /*
328          * Calculate the total length of the extension header chain.
329          * Keep the length of the unfragmentable part for fragmentation.
330          */
331         optlen = 0;
332         if (exthdrs.ip6e_hbh)
333                 optlen += exthdrs.ip6e_hbh->m_len;
334         if (exthdrs.ip6e_dest1)
335                 optlen += exthdrs.ip6e_dest1->m_len;
336         if (exthdrs.ip6e_rthdr)
337                 optlen += exthdrs.ip6e_rthdr->m_len;
338         unfragpartlen = optlen + sizeof(struct ip6_hdr);
339
340         /* NOTE: we don't add AH/ESP length here. do that later. */
341         if (exthdrs.ip6e_dest2)
342                 optlen += exthdrs.ip6e_dest2->m_len;
343
344         /*
345          * If we need IPsec, or there is at least one extension header,
346          * separate IP6 header from the payload.
347          */
348         if ((needipsec || optlen) && !hdrsplit) {
349                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
350                         m = NULL;
351                         goto freehdrs;
352                 }
353                 m = exthdrs.ip6e_ip6;
354                 hdrsplit++;
355         }
356
357         /* adjust pointer */
358         ip6 = mtod(m, struct ip6_hdr *);
359
360         /* adjust mbuf packet header length */
361         m->m_pkthdr.len += optlen;
362         plen = m->m_pkthdr.len - sizeof(*ip6);
363
364         /* If this is a jumbo payload, insert a jumbo payload option. */
365         if (plen > IPV6_MAXPACKET) {
366                 if (!hdrsplit) {
367                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
368                                 m = NULL;
369                                 goto freehdrs;
370                         }
371                         m = exthdrs.ip6e_ip6;
372                         hdrsplit++;
373                 }
374                 /* adjust pointer */
375                 ip6 = mtod(m, struct ip6_hdr *);
376                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
377                         goto freehdrs;
378                 ip6->ip6_plen = 0;
379         } else
380                 ip6->ip6_plen = htons(plen);
381
382         /*
383          * Concatenate headers and fill in next header fields.
384          * Here we have, on "m"
385          *      IPv6 payload
386          * and we insert headers accordingly.  Finally, we should be getting:
387          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
388          *
389          * during the header composing process, "m" points to IPv6 header.
390          * "mprev" points to an extension header prior to esp.
391          */
392         u_char *nexthdrp = &ip6->ip6_nxt;
393         mprev = m;
394
395         /*
396          * we treat dest2 specially.  this makes IPsec processing
397          * much easier.  the goal here is to make mprev point the
398          * mbuf prior to dest2.
399          *
400          * result: IPv6 dest2 payload
401          * m and mprev will point to IPv6 header.
402          */
403         if (exthdrs.ip6e_dest2) {
404                 if (!hdrsplit)
405                         panic("assumption failed: hdr not split");
406                 exthdrs.ip6e_dest2->m_next = m->m_next;
407                 m->m_next = exthdrs.ip6e_dest2;
408                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
409                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
410         }
411
412         /*
413          * result: IPv6 hbh dest1 rthdr dest2 payload
414          * m will point to IPv6 header.  mprev will point to the
415          * extension header prior to dest2 (rthdr in the above case).
416          */
417         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
418         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
419                    IPPROTO_DSTOPTS);
420         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
421                    IPPROTO_ROUTING);
422
423 #ifdef IPSEC
424         if (!needipsec)
425                 goto skip_ipsec2;
426
427         /*
428          * pointers after IPsec headers are not valid any more.
429          * other pointers need a great care too.
430          * (IPsec routines should not mangle mbufs prior to AH/ESP)
431          */
432         exthdrs.ip6e_dest2 = NULL;
433
434         if (exthdrs.ip6e_rthdr) {
435                 rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
436                 segleft_org = rh->ip6r_segleft;
437                 rh->ip6r_segleft = 0;
438         }
439
440         bzero(&state, sizeof(state));
441         state.m = m;
442         error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
443                                     &needipsectun);
444         m = state.m;
445         if (error == EJUSTRETURN) {
446                 /*
447                  * We had a SP with a level of 'use' and no SA. We
448                  * will just continue to process the packet without
449                  * IPsec processing.
450                  */
451                 ;
452         } else if (error) {
453                 /* mbuf is already reclaimed in ipsec6_output_trans. */
454                 m = NULL;
455                 switch (error) {
456                 case EHOSTUNREACH:
457                 case ENETUNREACH:
458                 case EMSGSIZE:
459                 case ENOBUFS:
460                 case ENOMEM:
461                         break;
462                 default:
463                         printf("[%s:%d] (ipsec): error code %d\n",
464                             __func__, __LINE__, error);
465                         /* FALLTHROUGH */
466                 case ENOENT:
467                         /* don't show these error codes to the user */
468                         error = 0;
469                         break;
470                 }
471                 goto bad;
472         } else if (!needipsectun) {
473                 /*
474                  * In the FAST IPSec case we have already
475                  * re-injected the packet and it has been freed
476                  * by the ipsec_done() function.  So, just clean
477                  * up after ourselves.
478                  */
479                 m = NULL;
480                 goto done;
481         }
482         if (exthdrs.ip6e_rthdr) {
483                 /* ah6_output doesn't modify mbuf chain */
484                 rh->ip6r_segleft = segleft_org;
485         }
486 skip_ipsec2:;
487 #endif /* IPSEC */
488
489         /*
490          * If there is a routing header, discard the packet.
491          */
492         if (exthdrs.ip6e_rthdr) {
493                  error = EINVAL;
494                  goto bad;
495         }
496
497         /* Source address validation */
498         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
499             (flags & IPV6_UNSPECSRC) == 0) {
500                 error = EOPNOTSUPP;
501                 V_ip6stat.ip6s_badscope++;
502                 goto bad;
503         }
504         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
505                 error = EOPNOTSUPP;
506                 V_ip6stat.ip6s_badscope++;
507                 goto bad;
508         }
509
510         V_ip6stat.ip6s_localout++;
511
512         /*
513          * Route packet.
514          */
515         if (ro == 0) {
516                 ro = &ip6route;
517                 bzero((caddr_t)ro, sizeof(*ro));
518         }
519         ro_pmtu = ro;
520         if (opt && opt->ip6po_rthdr)
521                 ro = &opt->ip6po_route;
522         dst = (struct sockaddr_in6 *)&ro->ro_dst;
523 #ifdef FLOWTABLE
524         if (ro->ro_rt == NULL) {
525                 struct flentry *fle;
526
527                 /*
528                  * The flow table returns route entries valid for up to 30
529                  * seconds; we rely on the remainder of ip_output() taking no
530                  * longer than that long for the stability of ro_rt.  The
531                  * flow ID assignment must have happened before this point.
532                  */
533                 fle = flowtable_lookup_mbuf(V_ip6_ft, m, AF_INET6);
534                 if (fle != NULL)
535                         flow_to_route_in6(fle, ro);
536         }
537 #endif
538 again:
539         /*
540          * if specified, try to fill in the traffic class field.
541          * do not override if a non-zero value is already set.
542          * we check the diffserv field and the ecn field separately.
543          */
544         if (opt && opt->ip6po_tclass >= 0) {
545                 int mask = 0;
546
547                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
548                         mask |= 0xfc;
549                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
550                         mask |= 0x03;
551                 if (mask != 0)
552                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
553         }
554
555         /* fill in or override the hop limit field, if necessary. */
556         if (opt && opt->ip6po_hlim != -1)
557                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
558         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
559                 if (im6o != NULL)
560                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
561                 else
562                         ip6->ip6_hlim = V_ip6_defmcasthlim;
563         }
564
565 #ifdef IPSEC
566         /*
567          * We may re-inject packets into the stack here.
568          */
569         if (needipsec && needipsectun) {
570                 struct ipsec_output_state state;
571
572                 /*
573                  * All the extension headers will become inaccessible
574                  * (since they can be encrypted).
575                  * Don't panic, we need no more updates to extension headers
576                  * on inner IPv6 packet (since they are now encapsulated).
577                  *
578                  * IPv6 [ESP|AH] IPv6 [extension headers] payload
579                  */
580                 bzero(&exthdrs, sizeof(exthdrs));
581                 exthdrs.ip6e_ip6 = m;
582
583                 bzero(&state, sizeof(state));
584                 state.m = m;
585                 state.ro = (struct route *)ro;
586                 state.dst = (struct sockaddr *)dst;
587
588                 error = ipsec6_output_tunnel(&state, sp, flags);
589
590                 m = state.m;
591                 ro = (struct route_in6 *)state.ro;
592                 dst = (struct sockaddr_in6 *)state.dst;
593                 if (error == EJUSTRETURN) {
594                         /*
595                          * We had a SP with a level of 'use' and no SA. We
596                          * will just continue to process the packet without
597                          * IPsec processing.
598                          */
599                         ;
600                 } else if (error) {
601                         /* mbuf is already reclaimed in ipsec6_output_tunnel. */
602                         m0 = m = NULL;
603                         m = NULL;
604                         switch (error) {
605                         case EHOSTUNREACH:
606                         case ENETUNREACH:
607                         case EMSGSIZE:
608                         case ENOBUFS:
609                         case ENOMEM:
610                                 break;
611                         default:
612                                 printf("[%s:%d] (ipsec): error code %d\n",
613                                     __func__, __LINE__, error);
614                                 /* FALLTHROUGH */
615                         case ENOENT:
616                                 /* don't show these error codes to the user */
617                                 error = 0;
618                                 break;
619                         }
620                         goto bad;
621                 } else {
622                         /*
623                          * In the FAST IPSec case we have already
624                          * re-injected the packet and it has been freed
625                          * by the ipsec_done() function.  So, just clean
626                          * up after ourselves.
627                          */
628                         m = NULL;
629                         goto done;
630                 }
631
632                 exthdrs.ip6e_ip6 = m;
633         }
634 #endif /* IPSEC */
635
636         /* adjust pointer */
637         ip6 = mtod(m, struct ip6_hdr *);
638
639         bzero(&dst_sa, sizeof(dst_sa));
640         dst_sa.sin6_family = AF_INET6;
641         dst_sa.sin6_len = sizeof(dst_sa);
642         dst_sa.sin6_addr = ip6->ip6_dst;
643         if (ro->ro_rt) {
644                 rt = ro->ro_rt;
645                 ifp = ro->ro_rt->rt_ifp;
646         } else if ((error = in6_selectroute_fib(&dst_sa, opt, im6o, ro,
647             &ifp, &rt, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m))) != 0) {
648                 switch (error) {
649                 case EHOSTUNREACH:
650                         V_ip6stat.ip6s_noroute++;
651                         break;
652                 case EADDRNOTAVAIL:
653                 default:
654                         break; /* XXX statistics? */
655                 }
656                 if (ifp != NULL)
657                         in6_ifstat_inc(ifp, ifs6_out_discard);
658                 goto bad;
659         }
660         if (rt == NULL) {
661                 /*
662                  * If in6_selectroute() does not return a route entry,
663                  * dst may not have been updated.
664                  */
665                 *dst = dst_sa;  /* XXX */
666         }
667
668         /*
669          * then rt (for unicast) and ifp must be non-NULL valid values.
670          */
671         if ((flags & IPV6_FORWARDING) == 0) {
672                 /* XXX: the FORWARDING flag can be set for mrouting. */
673                 in6_ifstat_inc(ifp, ifs6_out_request);
674         }
675         if (rt != NULL) {
676                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
677                 rt->rt_use++;
678         }
679
680
681         /*
682          * The outgoing interface must be in the zone of source and
683          * destination addresses.
684          */
685         origifp = ifp;
686
687         src0 = ip6->ip6_src;
688         if (in6_setscope(&src0, origifp, &zone))
689                 goto badscope;
690         bzero(&src_sa, sizeof(src_sa));
691         src_sa.sin6_family = AF_INET6;
692         src_sa.sin6_len = sizeof(src_sa);
693         src_sa.sin6_addr = ip6->ip6_src;
694         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
695                 goto badscope;
696
697         dst0 = ip6->ip6_dst;
698         if (in6_setscope(&dst0, origifp, &zone))
699                 goto badscope;
700         /* re-initialize to be sure */
701         bzero(&dst_sa, sizeof(dst_sa));
702         dst_sa.sin6_family = AF_INET6;
703         dst_sa.sin6_len = sizeof(dst_sa);
704         dst_sa.sin6_addr = ip6->ip6_dst;
705         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
706                 goto badscope;
707         }
708
709         /* We should use ia_ifp to support the case of
710          * sending packets to an address of our own.
711          */
712         if (ia != NULL && ia->ia_ifp)
713                 ifp = ia->ia_ifp;
714
715         /* scope check is done. */
716         goto routefound;
717
718   badscope:
719         V_ip6stat.ip6s_badscope++;
720         in6_ifstat_inc(origifp, ifs6_out_discard);
721         if (error == 0)
722                 error = EHOSTUNREACH; /* XXX */
723         goto bad;
724
725   routefound:
726         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
727                 if (opt && opt->ip6po_nextroute.ro_rt) {
728                         /*
729                          * The nexthop is explicitly specified by the
730                          * application.  We assume the next hop is an IPv6
731                          * address.
732                          */
733                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
734                 }
735                 else if ((rt->rt_flags & RTF_GATEWAY))
736                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
737         }
738
739         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
740                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
741         } else {
742                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
743                 in6_ifstat_inc(ifp, ifs6_out_mcast);
744                 /*
745                  * Confirm that the outgoing interface supports multicast.
746                  */
747                 if (!(ifp->if_flags & IFF_MULTICAST)) {
748                         V_ip6stat.ip6s_noroute++;
749                         in6_ifstat_inc(ifp, ifs6_out_discard);
750                         error = ENETUNREACH;
751                         goto bad;
752                 }
753                 if ((im6o == NULL && in6_mcast_loop) ||
754                     (im6o && im6o->im6o_multicast_loop)) {
755                         /*
756                          * Loop back multicast datagram if not expressly
757                          * forbidden to do so, even if we have not joined
758                          * the address; protocols will filter it later,
759                          * thus deferring a hash lookup and lock acquisition
760                          * at the expense of an m_copym().
761                          */
762                         ip6_mloopback(ifp, m, dst);
763                 } else {
764                         /*
765                          * If we are acting as a multicast router, perform
766                          * multicast forwarding as if the packet had just
767                          * arrived on the interface to which we are about
768                          * to send.  The multicast forwarding function
769                          * recursively calls this function, using the
770                          * IPV6_FORWARDING flag to prevent infinite recursion.
771                          *
772                          * Multicasts that are looped back by ip6_mloopback(),
773                          * above, will be forwarded by the ip6_input() routine,
774                          * if necessary.
775                          */
776                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
777                                 /*
778                                  * XXX: ip6_mforward expects that rcvif is NULL
779                                  * when it is called from the originating path.
780                                  * However, it is not always the case, since
781                                  * some versions of MGETHDR() does not
782                                  * initialize the field.
783                                  */
784                                 m->m_pkthdr.rcvif = NULL;
785                                 if (ip6_mforward(ip6, ifp, m) != 0) {
786                                         m_freem(m);
787                                         goto done;
788                                 }
789                         }
790                 }
791                 /*
792                  * Multicasts with a hoplimit of zero may be looped back,
793                  * above, but must not be transmitted on a network.
794                  * Also, multicasts addressed to the loopback interface
795                  * are not sent -- the above call to ip6_mloopback() will
796                  * loop back a copy if this host actually belongs to the
797                  * destination group on the loopback interface.
798                  */
799                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
800                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
801                         m_freem(m);
802                         goto done;
803                 }
804         }
805
806         /*
807          * Fill the outgoing inteface to tell the upper layer
808          * to increment per-interface statistics.
809          */
810         if (ifpp)
811                 *ifpp = ifp;
812
813         /* Determine path MTU. */
814         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
815             &alwaysfrag, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m))) != 0)
816                 goto bad;
817
818         /*
819          * The caller of this function may specify to use the minimum MTU
820          * in some cases.
821          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
822          * setting.  The logic is a bit complicated; by default, unicast
823          * packets will follow path MTU while multicast packets will be sent at
824          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
825          * including unicast ones will be sent at the minimum MTU.  Multicast
826          * packets will always be sent at the minimum MTU unless
827          * IP6PO_MINMTU_DISABLE is explicitly specified.
828          * See RFC 3542 for more details.
829          */
830         if (mtu > IPV6_MMTU) {
831                 if ((flags & IPV6_MINMTU))
832                         mtu = IPV6_MMTU;
833                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
834                         mtu = IPV6_MMTU;
835                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
836                          (opt == NULL ||
837                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
838                         mtu = IPV6_MMTU;
839                 }
840         }
841
842         /*
843          * clear embedded scope identifiers if necessary.
844          * in6_clearscope will touch the addresses only when necessary.
845          */
846         in6_clearscope(&ip6->ip6_src);
847         in6_clearscope(&ip6->ip6_dst);
848
849         /*
850          * If the outgoing packet contains a hop-by-hop options header,
851          * it must be examined and processed even by the source node.
852          * (RFC 2460, section 4.)
853          */
854         if (exthdrs.ip6e_hbh) {
855                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
856                 u_int32_t dummy; /* XXX unused */
857                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
858
859 #ifdef DIAGNOSTIC
860                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
861                         panic("ip6e_hbh is not contiguous");
862 #endif
863                 /*
864                  *  XXX: if we have to send an ICMPv6 error to the sender,
865                  *       we need the M_LOOP flag since icmp6_error() expects
866                  *       the IPv6 and the hop-by-hop options header are
867                  *       contiguous unless the flag is set.
868                  */
869                 m->m_flags |= M_LOOP;
870                 m->m_pkthdr.rcvif = ifp;
871                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
872                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
873                     &dummy, &plen) < 0) {
874                         /* m was already freed at this point */
875                         error = EINVAL;/* better error? */
876                         goto done;
877                 }
878                 m->m_flags &= ~M_LOOP; /* XXX */
879                 m->m_pkthdr.rcvif = NULL;
880         }
881
882         /* Jump over all PFIL processing if hooks are not active. */
883         if (!PFIL_HOOKED(&V_inet6_pfil_hook))
884                 goto passout;
885
886         odst = ip6->ip6_dst;
887         /* Run through list of hooks for output packets. */
888         error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
889         if (error != 0 || m == NULL)
890                 goto done;
891         ip6 = mtod(m, struct ip6_hdr *);
892
893         /* See if destination IP address was changed by packet filter. */
894         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
895                 m->m_flags |= M_SKIP_FIREWALL;
896                 /* If destination is now ourself drop to ip6_input(). */
897                 if (in6_localip(&ip6->ip6_dst)) {
898                         m->m_flags |= M_FASTFWD_OURS;
899                         if (m->m_pkthdr.rcvif == NULL)
900                                 m->m_pkthdr.rcvif = V_loif;
901                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
902                                 m->m_pkthdr.csum_flags |=
903                                     CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
904                                 m->m_pkthdr.csum_data = 0xffff;
905                         }
906 #ifdef SCTP
907                         if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
908                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
909 #endif
910                         error = netisr_queue(NETISR_IPV6, m);
911                         goto done;
912                 } else
913                         goto again;     /* Redo the routing table lookup. */
914         }
915
916         /* See if local, if yes, send it to netisr. */
917         if (m->m_flags & M_FASTFWD_OURS) {
918                 if (m->m_pkthdr.rcvif == NULL)
919                         m->m_pkthdr.rcvif = V_loif;
920                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
921                         m->m_pkthdr.csum_flags |=
922                             CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
923                         m->m_pkthdr.csum_data = 0xffff;
924                 }
925 #ifdef SCTP
926                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
927                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
928 #endif
929                 error = netisr_queue(NETISR_IPV6, m);
930                 goto done;
931         }
932         /* Or forward to some other address? */
933         if ((m->m_flags & M_IP6_NEXTHOP) &&
934             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
935                 dst = (struct sockaddr_in6 *)&ro->ro_dst;
936                 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6));
937                 m->m_flags |= M_SKIP_FIREWALL;
938                 m->m_flags &= ~M_IP6_NEXTHOP;
939                 m_tag_delete(m, fwd_tag);
940                 goto again;
941         }
942
943 passout:
944         /*
945          * Send the packet to the outgoing interface.
946          * If necessary, do IPv6 fragmentation before sending.
947          *
948          * the logic here is rather complex:
949          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
950          * 1-a: send as is if tlen <= path mtu
951          * 1-b: fragment if tlen > path mtu
952          *
953          * 2: if user asks us not to fragment (dontfrag == 1)
954          * 2-a: send as is if tlen <= interface mtu
955          * 2-b: error if tlen > interface mtu
956          *
957          * 3: if we always need to attach fragment header (alwaysfrag == 1)
958          *      always fragment
959          *
960          * 4: if dontfrag == 1 && alwaysfrag == 1
961          *      error, as we cannot handle this conflicting request
962          */
963         sw_csum = m->m_pkthdr.csum_flags;
964         if (!hdrsplit) {
965                 tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
966                 sw_csum &= ~ifp->if_hwassist;
967         } else
968                 tso = 0;
969         /*
970          * If we added extension headers, we will not do TSO and calculate the
971          * checksums ourselves for now.
972          * XXX-BZ  Need a framework to know when the NIC can handle it, even
973          * with ext. hdrs.
974          */
975         if (sw_csum & CSUM_DELAY_DATA_IPV6) {
976                 sw_csum &= ~CSUM_DELAY_DATA_IPV6;
977                 in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
978         }
979 #ifdef SCTP
980         if (sw_csum & CSUM_SCTP_IPV6) {
981                 sw_csum &= ~CSUM_SCTP_IPV6;
982                 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
983         }
984 #endif
985         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
986         tlen = m->m_pkthdr.len;
987
988         if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
989                 dontfrag = 1;
990         else
991                 dontfrag = 0;
992         if (dontfrag && alwaysfrag) {   /* case 4 */
993                 /* conflicting request - can't transmit */
994                 error = EMSGSIZE;
995                 goto bad;
996         }
997         if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {      /* case 2-b */
998                 /*
999                  * Even if the DONTFRAG option is specified, we cannot send the
1000                  * packet when the data length is larger than the MTU of the
1001                  * outgoing interface.
1002                  * Notify the error by sending IPV6_PATHMTU ancillary data as
1003                  * well as returning an error code (the latter is not described
1004                  * in the API spec.)
1005                  */
1006                 u_int32_t mtu32;
1007                 struct ip6ctlparam ip6cp;
1008
1009                 mtu32 = (u_int32_t)mtu;
1010                 bzero(&ip6cp, sizeof(ip6cp));
1011                 ip6cp.ip6c_cmdarg = (void *)&mtu32;
1012                 pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
1013                     (void *)&ip6cp);
1014
1015                 error = EMSGSIZE;
1016                 goto bad;
1017         }
1018
1019         /*
1020          * transmit packet without fragmentation
1021          */
1022         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
1023                 struct in6_ifaddr *ia6;
1024
1025                 ip6 = mtod(m, struct ip6_hdr *);
1026                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
1027                 if (ia6) {
1028                         /* Record statistics for this interface address. */
1029                         ia6->ia_ifa.if_opackets++;
1030                         ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
1031                         ifa_free(&ia6->ia_ifa);
1032                 }
1033                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1034                 goto done;
1035         }
1036
1037         /*
1038          * try to fragment the packet.  case 1-b and 3
1039          */
1040         if (mtu < IPV6_MMTU) {
1041                 /* path MTU cannot be less than IPV6_MMTU */
1042                 error = EMSGSIZE;
1043                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
1044                 goto bad;
1045         } else if (ip6->ip6_plen == 0) {
1046                 /* jumbo payload cannot be fragmented */
1047                 error = EMSGSIZE;
1048                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
1049                 goto bad;
1050         } else {
1051                 struct mbuf **mnext, *m_frgpart;
1052                 struct ip6_frag *ip6f;
1053                 u_int32_t id = htonl(ip6_randomid());
1054                 u_char nextproto;
1055
1056                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
1057
1058                 /*
1059                  * Too large for the destination or interface;
1060                  * fragment if possible.
1061                  * Must be able to put at least 8 bytes per fragment.
1062                  */
1063                 hlen = unfragpartlen;
1064                 if (mtu > IPV6_MAXPACKET)
1065                         mtu = IPV6_MAXPACKET;
1066
1067                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
1068                 if (len < 8) {
1069                         error = EMSGSIZE;
1070                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
1071                         goto bad;
1072                 }
1073
1074                 /*
1075                  * Verify that we have any chance at all of being able to queue
1076                  *      the packet or packet fragments
1077                  */
1078                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
1079                     < tlen  /* - hlen */)) {
1080                         error = ENOBUFS;
1081                         V_ip6stat.ip6s_odropped++;
1082                         goto bad;
1083                 }
1084
1085
1086                 /*
1087                  * If the interface will not calculate checksums on
1088                  * fragmented packets, then do it here.
1089                  * XXX-BZ handle the hw offloading case.  Need flags.
1090                  */
1091                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1092                         in6_delayed_cksum(m, plen, hlen);
1093                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
1094                 }
1095 #ifdef SCTP
1096                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
1097                         sctp_delayed_cksum(m, hlen);
1098                         m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
1099                 }
1100 #endif
1101                 mnext = &m->m_nextpkt;
1102
1103                 /*
1104                  * Change the next header field of the last header in the
1105                  * unfragmentable part.
1106                  */
1107                 if (exthdrs.ip6e_rthdr) {
1108                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1109                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1110                 } else if (exthdrs.ip6e_dest1) {
1111                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1112                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1113                 } else if (exthdrs.ip6e_hbh) {
1114                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1115                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1116                 } else {
1117                         nextproto = ip6->ip6_nxt;
1118                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
1119                 }
1120
1121                 /*
1122                  * Loop through length of segment after first fragment,
1123                  * make new header and copy data of each part and link onto
1124                  * chain.
1125                  */
1126                 m0 = m;
1127                 for (off = hlen; off < tlen; off += len) {
1128                         MGETHDR(m, M_DONTWAIT, MT_HEADER);
1129                         if (!m) {
1130                                 error = ENOBUFS;
1131                                 V_ip6stat.ip6s_odropped++;
1132                                 goto sendorfree;
1133                         }
1134                         m->m_pkthdr.rcvif = NULL;
1135                         m->m_flags = m0->m_flags & M_COPYFLAGS; /* incl. FIB */
1136                         *mnext = m;
1137                         mnext = &m->m_nextpkt;
1138                         m->m_data += max_linkhdr;
1139                         mhip6 = mtod(m, struct ip6_hdr *);
1140                         *mhip6 = *ip6;
1141                         m->m_len = sizeof(*mhip6);
1142                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1143                         if (error) {
1144                                 V_ip6stat.ip6s_odropped++;
1145                                 goto sendorfree;
1146                         }
1147                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1148                         if (off + len >= tlen)
1149                                 len = tlen - off;
1150                         else
1151                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1152                         mhip6->ip6_plen = htons((u_short)(len + hlen +
1153                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1154                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1155                                 error = ENOBUFS;
1156                                 V_ip6stat.ip6s_odropped++;
1157                                 goto sendorfree;
1158                         }
1159                         m_cat(m, m_frgpart);
1160                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1161                         m->m_pkthdr.rcvif = NULL;
1162                         ip6f->ip6f_reserved = 0;
1163                         ip6f->ip6f_ident = id;
1164                         ip6f->ip6f_nxt = nextproto;
1165                         V_ip6stat.ip6s_ofragments++;
1166                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1167                 }
1168
1169                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1170         }
1171
1172         /*
1173          * Remove leading garbages.
1174          */
1175 sendorfree:
1176         m = m0->m_nextpkt;
1177         m0->m_nextpkt = 0;
1178         m_freem(m0);
1179         for (m0 = m; m; m = m0) {
1180                 m0 = m->m_nextpkt;
1181                 m->m_nextpkt = 0;
1182                 if (error == 0) {
1183                         /* Record statistics for this interface address. */
1184                         if (ia) {
1185                                 ia->ia_ifa.if_opackets++;
1186                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1187                         }
1188                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1189                 } else
1190                         m_freem(m);
1191         }
1192
1193         if (error == 0)
1194                 V_ip6stat.ip6s_fragmented++;
1195
1196 done:
1197         if (ro == &ip6route)
1198                 RO_RTFREE(ro);
1199         if (ro_pmtu == &ip6route)
1200                 RO_RTFREE(ro_pmtu);
1201 #ifdef IPSEC
1202         if (sp != NULL)
1203                 KEY_FREESP(&sp);
1204 #endif
1205
1206         return (error);
1207
1208 freehdrs:
1209         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1210         m_freem(exthdrs.ip6e_dest1);
1211         m_freem(exthdrs.ip6e_rthdr);
1212         m_freem(exthdrs.ip6e_dest2);
1213         /* FALLTHROUGH */
1214 bad:
1215         if (m)
1216                 m_freem(m);
1217         goto done;
1218 }
1219
1220 static int
1221 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1222 {
1223         struct mbuf *m;
1224
1225         if (hlen > MCLBYTES)
1226                 return (ENOBUFS); /* XXX */
1227
1228         MGET(m, M_DONTWAIT, MT_DATA);
1229         if (!m)
1230                 return (ENOBUFS);
1231
1232         if (hlen > MLEN) {
1233                 MCLGET(m, M_DONTWAIT);
1234                 if ((m->m_flags & M_EXT) == 0) {
1235                         m_free(m);
1236                         return (ENOBUFS);
1237                 }
1238         }
1239         m->m_len = hlen;
1240         if (hdr)
1241                 bcopy(hdr, mtod(m, caddr_t), hlen);
1242
1243         *mp = m;
1244         return (0);
1245 }
1246
1247 /*
1248  * Insert jumbo payload option.
1249  */
1250 static int
1251 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1252 {
1253         struct mbuf *mopt;
1254         u_char *optbuf;
1255         u_int32_t v;
1256
1257 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1258
1259         /*
1260          * If there is no hop-by-hop options header, allocate new one.
1261          * If there is one but it doesn't have enough space to store the
1262          * jumbo payload option, allocate a cluster to store the whole options.
1263          * Otherwise, use it to store the options.
1264          */
1265         if (exthdrs->ip6e_hbh == 0) {
1266                 MGET(mopt, M_DONTWAIT, MT_DATA);
1267                 if (mopt == 0)
1268                         return (ENOBUFS);
1269                 mopt->m_len = JUMBOOPTLEN;
1270                 optbuf = mtod(mopt, u_char *);
1271                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1272                 exthdrs->ip6e_hbh = mopt;
1273         } else {
1274                 struct ip6_hbh *hbh;
1275
1276                 mopt = exthdrs->ip6e_hbh;
1277                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1278                         /*
1279                          * XXX assumption:
1280                          * - exthdrs->ip6e_hbh is not referenced from places
1281                          *   other than exthdrs.
1282                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1283                          */
1284                         int oldoptlen = mopt->m_len;
1285                         struct mbuf *n;
1286
1287                         /*
1288                          * XXX: give up if the whole (new) hbh header does
1289                          * not fit even in an mbuf cluster.
1290                          */
1291                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1292                                 return (ENOBUFS);
1293
1294                         /*
1295                          * As a consequence, we must always prepare a cluster
1296                          * at this point.
1297                          */
1298                         MGET(n, M_DONTWAIT, MT_DATA);
1299                         if (n) {
1300                                 MCLGET(n, M_DONTWAIT);
1301                                 if ((n->m_flags & M_EXT) == 0) {
1302                                         m_freem(n);
1303                                         n = NULL;
1304                                 }
1305                         }
1306                         if (!n)
1307                                 return (ENOBUFS);
1308                         n->m_len = oldoptlen + JUMBOOPTLEN;
1309                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1310                             oldoptlen);
1311                         optbuf = mtod(n, caddr_t) + oldoptlen;
1312                         m_freem(mopt);
1313                         mopt = exthdrs->ip6e_hbh = n;
1314                 } else {
1315                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1316                         mopt->m_len += JUMBOOPTLEN;
1317                 }
1318                 optbuf[0] = IP6OPT_PADN;
1319                 optbuf[1] = 1;
1320
1321                 /*
1322                  * Adjust the header length according to the pad and
1323                  * the jumbo payload option.
1324                  */
1325                 hbh = mtod(mopt, struct ip6_hbh *);
1326                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1327         }
1328
1329         /* fill in the option. */
1330         optbuf[2] = IP6OPT_JUMBO;
1331         optbuf[3] = 4;
1332         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1333         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1334
1335         /* finally, adjust the packet header length */
1336         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1337
1338         return (0);
1339 #undef JUMBOOPTLEN
1340 }
1341
1342 /*
1343  * Insert fragment header and copy unfragmentable header portions.
1344  */
1345 static int
1346 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1347     struct ip6_frag **frghdrp)
1348 {
1349         struct mbuf *n, *mlast;
1350
1351         if (hlen > sizeof(struct ip6_hdr)) {
1352                 n = m_copym(m0, sizeof(struct ip6_hdr),
1353                     hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
1354                 if (n == 0)
1355                         return (ENOBUFS);
1356                 m->m_next = n;
1357         } else
1358                 n = m;
1359
1360         /* Search for the last mbuf of unfragmentable part. */
1361         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1362                 ;
1363
1364         if ((mlast->m_flags & M_EXT) == 0 &&
1365             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1366                 /* use the trailing space of the last mbuf for the fragment hdr */
1367                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1368                     mlast->m_len);
1369                 mlast->m_len += sizeof(struct ip6_frag);
1370                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1371         } else {
1372                 /* allocate a new mbuf for the fragment header */
1373                 struct mbuf *mfrg;
1374
1375                 MGET(mfrg, M_DONTWAIT, MT_DATA);
1376                 if (mfrg == 0)
1377                         return (ENOBUFS);
1378                 mfrg->m_len = sizeof(struct ip6_frag);
1379                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1380                 mlast->m_next = mfrg;
1381         }
1382
1383         return (0);
1384 }
1385
1386 static int
1387 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1388     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1389     int *alwaysfragp, u_int fibnum)
1390 {
1391         u_int32_t mtu = 0;
1392         int alwaysfrag = 0;
1393         int error = 0;
1394
1395         if (ro_pmtu != ro) {
1396                 /* The first hop and the final destination may differ. */
1397                 struct sockaddr_in6 *sa6_dst =
1398                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1399                 if (ro_pmtu->ro_rt &&
1400                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1401                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1402                         RTFREE(ro_pmtu->ro_rt);
1403                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
1404                 }
1405                 if (ro_pmtu->ro_rt == NULL) {
1406                         bzero(sa6_dst, sizeof(*sa6_dst));
1407                         sa6_dst->sin6_family = AF_INET6;
1408                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1409                         sa6_dst->sin6_addr = *dst;
1410
1411                         in6_rtalloc(ro_pmtu, fibnum);
1412                 }
1413         }
1414         if (ro_pmtu->ro_rt) {
1415                 u_int32_t ifmtu;
1416                 struct in_conninfo inc;
1417
1418                 bzero(&inc, sizeof(inc));
1419                 inc.inc_flags |= INC_ISIPV6;
1420                 inc.inc6_faddr = *dst;
1421
1422                 if (ifp == NULL)
1423                         ifp = ro_pmtu->ro_rt->rt_ifp;
1424                 ifmtu = IN6_LINKMTU(ifp);
1425                 mtu = tcp_hc_getmtu(&inc);
1426                 if (mtu)
1427                         mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
1428                 else
1429                         mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1430                 if (mtu == 0)
1431                         mtu = ifmtu;
1432                 else if (mtu < IPV6_MMTU) {
1433                         /*
1434                          * RFC2460 section 5, last paragraph:
1435                          * if we record ICMPv6 too big message with
1436                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1437                          * or smaller, with framgent header attached.
1438                          * (fragment header is needed regardless from the
1439                          * packet size, for translators to identify packets)
1440                          */
1441                         alwaysfrag = 1;
1442                         mtu = IPV6_MMTU;
1443                 } else if (mtu > ifmtu) {
1444                         /*
1445                          * The MTU on the route is larger than the MTU on
1446                          * the interface!  This shouldn't happen, unless the
1447                          * MTU of the interface has been changed after the
1448                          * interface was brought up.  Change the MTU in the
1449                          * route to match the interface MTU (as long as the
1450                          * field isn't locked).
1451                          */
1452                         mtu = ifmtu;
1453                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1454                 }
1455         } else if (ifp) {
1456                 mtu = IN6_LINKMTU(ifp);
1457         } else
1458                 error = EHOSTUNREACH; /* XXX */
1459
1460         *mtup = mtu;
1461         if (alwaysfragp)
1462                 *alwaysfragp = alwaysfrag;
1463         return (error);
1464 }
1465
1466 /*
1467  * IP6 socket option processing.
1468  */
1469 int
1470 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1471 {
1472         int optdatalen, uproto;
1473         void *optdata;
1474         struct inpcb *in6p = sotoinpcb(so);
1475         int error, optval;
1476         int level, op, optname;
1477         int optlen;
1478         struct thread *td;
1479
1480         level = sopt->sopt_level;
1481         op = sopt->sopt_dir;
1482         optname = sopt->sopt_name;
1483         optlen = sopt->sopt_valsize;
1484         td = sopt->sopt_td;
1485         error = 0;
1486         optval = 0;
1487         uproto = (int)so->so_proto->pr_protocol;
1488
1489         if (level != IPPROTO_IPV6) {
1490                 error = EINVAL;
1491
1492                 if (sopt->sopt_level == SOL_SOCKET &&
1493                     sopt->sopt_dir == SOPT_SET) {
1494                         switch (sopt->sopt_name) {
1495                         case SO_REUSEADDR:
1496                                 INP_WLOCK(in6p);
1497                                 if (IN_MULTICAST(ntohl(in6p->inp_laddr.s_addr))) {
1498                                         if ((so->so_options &
1499                                             (SO_REUSEADDR | SO_REUSEPORT)) != 0)
1500                                                 in6p->inp_flags2 |= INP_REUSEPORT;
1501                                         else
1502                                                 in6p->inp_flags2 &= ~INP_REUSEPORT;
1503                                 }
1504                                 INP_WUNLOCK(in6p);
1505                                 error = 0;
1506                                 break;
1507                         case SO_REUSEPORT:
1508                                 INP_WLOCK(in6p);
1509                                 if ((so->so_options & SO_REUSEPORT) != 0)
1510                                         in6p->inp_flags2 |= INP_REUSEPORT;
1511                                 else
1512                                         in6p->inp_flags2 &= ~INP_REUSEPORT;
1513                                 INP_WUNLOCK(in6p);
1514                                 error = 0;
1515                                 break;
1516                         case SO_SETFIB:
1517                                 INP_WLOCK(in6p);
1518                                 in6p->inp_inc.inc_fibnum = so->so_fibnum;
1519                                 INP_WUNLOCK(in6p);
1520                                 error = 0;
1521                                 break;
1522                         default:
1523                                 break;
1524                         }
1525                 }
1526         } else {                /* level == IPPROTO_IPV6 */
1527                 switch (op) {
1528
1529                 case SOPT_SET:
1530                         switch (optname) {
1531                         case IPV6_2292PKTOPTIONS:
1532 #ifdef IPV6_PKTOPTIONS
1533                         case IPV6_PKTOPTIONS:
1534 #endif
1535                         {
1536                                 struct mbuf *m;
1537
1538                                 error = soopt_getm(sopt, &m); /* XXX */
1539                                 if (error != 0)
1540                                         break;
1541                                 error = soopt_mcopyin(sopt, m); /* XXX */
1542                                 if (error != 0)
1543                                         break;
1544                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1545                                                     m, so, sopt);
1546                                 m_freem(m); /* XXX */
1547                                 break;
1548                         }
1549
1550                         /*
1551                          * Use of some Hop-by-Hop options or some
1552                          * Destination options, might require special
1553                          * privilege.  That is, normal applications
1554                          * (without special privilege) might be forbidden
1555                          * from setting certain options in outgoing packets,
1556                          * and might never see certain options in received
1557                          * packets. [RFC 2292 Section 6]
1558                          * KAME specific note:
1559                          *  KAME prevents non-privileged users from sending or
1560                          *  receiving ANY hbh/dst options in order to avoid
1561                          *  overhead of parsing options in the kernel.
1562                          */
1563                         case IPV6_RECVHOPOPTS:
1564                         case IPV6_RECVDSTOPTS:
1565                         case IPV6_RECVRTHDRDSTOPTS:
1566                                 if (td != NULL) {
1567                                         error = priv_check(td,
1568                                             PRIV_NETINET_SETHDROPTS);
1569                                         if (error)
1570                                                 break;
1571                                 }
1572                                 /* FALLTHROUGH */
1573                         case IPV6_UNICAST_HOPS:
1574                         case IPV6_HOPLIMIT:
1575                         case IPV6_FAITH:
1576
1577                         case IPV6_RECVPKTINFO:
1578                         case IPV6_RECVHOPLIMIT:
1579                         case IPV6_RECVRTHDR:
1580                         case IPV6_RECVPATHMTU:
1581                         case IPV6_RECVTCLASS:
1582                         case IPV6_V6ONLY:
1583                         case IPV6_AUTOFLOWLABEL:
1584                         case IPV6_BINDANY:
1585                                 if (optname == IPV6_BINDANY && td != NULL) {
1586                                         error = priv_check(td,
1587                                             PRIV_NETINET_BINDANY);
1588                                         if (error)
1589                                                 break;
1590                                 }
1591
1592                                 if (optlen != sizeof(int)) {
1593                                         error = EINVAL;
1594                                         break;
1595                                 }
1596                                 error = sooptcopyin(sopt, &optval,
1597                                         sizeof optval, sizeof optval);
1598                                 if (error)
1599                                         break;
1600                                 switch (optname) {
1601
1602                                 case IPV6_UNICAST_HOPS:
1603                                         if (optval < -1 || optval >= 256)
1604                                                 error = EINVAL;
1605                                         else {
1606                                                 /* -1 = kernel default */
1607                                                 in6p->in6p_hops = optval;
1608                                                 if ((in6p->inp_vflag &
1609                                                      INP_IPV4) != 0)
1610                                                         in6p->inp_ip_ttl = optval;
1611                                         }
1612                                         break;
1613 #define OPTSET(bit) \
1614 do { \
1615         INP_WLOCK(in6p); \
1616         if (optval) \
1617                 in6p->inp_flags |= (bit); \
1618         else \
1619                 in6p->inp_flags &= ~(bit); \
1620         INP_WUNLOCK(in6p); \
1621 } while (/*CONSTCOND*/ 0)
1622 #define OPTSET2292(bit) \
1623 do { \
1624         INP_WLOCK(in6p); \
1625         in6p->inp_flags |= IN6P_RFC2292; \
1626         if (optval) \
1627                 in6p->inp_flags |= (bit); \
1628         else \
1629                 in6p->inp_flags &= ~(bit); \
1630         INP_WUNLOCK(in6p); \
1631 } while (/*CONSTCOND*/ 0)
1632 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1633
1634                                 case IPV6_RECVPKTINFO:
1635                                         /* cannot mix with RFC2292 */
1636                                         if (OPTBIT(IN6P_RFC2292)) {
1637                                                 error = EINVAL;
1638                                                 break;
1639                                         }
1640                                         OPTSET(IN6P_PKTINFO);
1641                                         break;
1642
1643                                 case IPV6_HOPLIMIT:
1644                                 {
1645                                         struct ip6_pktopts **optp;
1646
1647                                         /* cannot mix with RFC2292 */
1648                                         if (OPTBIT(IN6P_RFC2292)) {
1649                                                 error = EINVAL;
1650                                                 break;
1651                                         }
1652                                         optp = &in6p->in6p_outputopts;
1653                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1654                                             (u_char *)&optval, sizeof(optval),
1655                                             optp, (td != NULL) ? td->td_ucred :
1656                                             NULL, uproto);
1657                                         break;
1658                                 }
1659
1660                                 case IPV6_RECVHOPLIMIT:
1661                                         /* cannot mix with RFC2292 */
1662                                         if (OPTBIT(IN6P_RFC2292)) {
1663                                                 error = EINVAL;
1664                                                 break;
1665                                         }
1666                                         OPTSET(IN6P_HOPLIMIT);
1667                                         break;
1668
1669                                 case IPV6_RECVHOPOPTS:
1670                                         /* cannot mix with RFC2292 */
1671                                         if (OPTBIT(IN6P_RFC2292)) {
1672                                                 error = EINVAL;
1673                                                 break;
1674                                         }
1675                                         OPTSET(IN6P_HOPOPTS);
1676                                         break;
1677
1678                                 case IPV6_RECVDSTOPTS:
1679                                         /* cannot mix with RFC2292 */
1680                                         if (OPTBIT(IN6P_RFC2292)) {
1681                                                 error = EINVAL;
1682                                                 break;
1683                                         }
1684                                         OPTSET(IN6P_DSTOPTS);
1685                                         break;
1686
1687                                 case IPV6_RECVRTHDRDSTOPTS:
1688                                         /* cannot mix with RFC2292 */
1689                                         if (OPTBIT(IN6P_RFC2292)) {
1690                                                 error = EINVAL;
1691                                                 break;
1692                                         }
1693                                         OPTSET(IN6P_RTHDRDSTOPTS);
1694                                         break;
1695
1696                                 case IPV6_RECVRTHDR:
1697                                         /* cannot mix with RFC2292 */
1698                                         if (OPTBIT(IN6P_RFC2292)) {
1699                                                 error = EINVAL;
1700                                                 break;
1701                                         }
1702                                         OPTSET(IN6P_RTHDR);
1703                                         break;
1704
1705                                 case IPV6_FAITH:
1706                                         OPTSET(INP_FAITH);
1707                                         break;
1708
1709                                 case IPV6_RECVPATHMTU:
1710                                         /*
1711                                          * We ignore this option for TCP
1712                                          * sockets.
1713                                          * (RFC3542 leaves this case
1714                                          * unspecified.)
1715                                          */
1716                                         if (uproto != IPPROTO_TCP)
1717                                                 OPTSET(IN6P_MTU);
1718                                         break;
1719
1720                                 case IPV6_V6ONLY:
1721                                         /*
1722                                          * make setsockopt(IPV6_V6ONLY)
1723                                          * available only prior to bind(2).
1724                                          * see ipng mailing list, Jun 22 2001.
1725                                          */
1726                                         if (in6p->inp_lport ||
1727                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1728                                                 error = EINVAL;
1729                                                 break;
1730                                         }
1731                                         OPTSET(IN6P_IPV6_V6ONLY);
1732                                         if (optval)
1733                                                 in6p->inp_vflag &= ~INP_IPV4;
1734                                         else
1735                                                 in6p->inp_vflag |= INP_IPV4;
1736                                         break;
1737                                 case IPV6_RECVTCLASS:
1738                                         /* cannot mix with RFC2292 XXX */
1739                                         if (OPTBIT(IN6P_RFC2292)) {
1740                                                 error = EINVAL;
1741                                                 break;
1742                                         }
1743                                         OPTSET(IN6P_TCLASS);
1744                                         break;
1745                                 case IPV6_AUTOFLOWLABEL:
1746                                         OPTSET(IN6P_AUTOFLOWLABEL);
1747                                         break;
1748
1749                                 case IPV6_BINDANY:
1750                                         OPTSET(INP_BINDANY);
1751                                         break;
1752                                 }
1753                                 break;
1754
1755                         case IPV6_TCLASS:
1756                         case IPV6_DONTFRAG:
1757                         case IPV6_USE_MIN_MTU:
1758                         case IPV6_PREFER_TEMPADDR:
1759                                 if (optlen != sizeof(optval)) {
1760                                         error = EINVAL;
1761                                         break;
1762                                 }
1763                                 error = sooptcopyin(sopt, &optval,
1764                                         sizeof optval, sizeof optval);
1765                                 if (error)
1766                                         break;
1767                                 {
1768                                         struct ip6_pktopts **optp;
1769                                         optp = &in6p->in6p_outputopts;
1770                                         error = ip6_pcbopt(optname,
1771                                             (u_char *)&optval, sizeof(optval),
1772                                             optp, (td != NULL) ? td->td_ucred :
1773                                             NULL, uproto);
1774                                         break;
1775                                 }
1776
1777                         case IPV6_2292PKTINFO:
1778                         case IPV6_2292HOPLIMIT:
1779                         case IPV6_2292HOPOPTS:
1780                         case IPV6_2292DSTOPTS:
1781                         case IPV6_2292RTHDR:
1782                                 /* RFC 2292 */
1783                                 if (optlen != sizeof(int)) {
1784                                         error = EINVAL;
1785                                         break;
1786                                 }
1787                                 error = sooptcopyin(sopt, &optval,
1788                                         sizeof optval, sizeof optval);
1789                                 if (error)
1790                                         break;
1791                                 switch (optname) {
1792                                 case IPV6_2292PKTINFO:
1793                                         OPTSET2292(IN6P_PKTINFO);
1794                                         break;
1795                                 case IPV6_2292HOPLIMIT:
1796                                         OPTSET2292(IN6P_HOPLIMIT);
1797                                         break;
1798                                 case IPV6_2292HOPOPTS:
1799                                         /*
1800                                          * Check super-user privilege.
1801                                          * See comments for IPV6_RECVHOPOPTS.
1802                                          */
1803                                         if (td != NULL) {
1804                                                 error = priv_check(td,
1805                                                     PRIV_NETINET_SETHDROPTS);
1806                                                 if (error)
1807                                                         return (error);
1808                                         }
1809                                         OPTSET2292(IN6P_HOPOPTS);
1810                                         break;
1811                                 case IPV6_2292DSTOPTS:
1812                                         if (td != NULL) {
1813                                                 error = priv_check(td,
1814                                                     PRIV_NETINET_SETHDROPTS);
1815                                                 if (error)
1816                                                         return (error);
1817                                         }
1818                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1819                                         break;
1820                                 case IPV6_2292RTHDR:
1821                                         OPTSET2292(IN6P_RTHDR);
1822                                         break;
1823                                 }
1824                                 break;
1825                         case IPV6_PKTINFO:
1826                         case IPV6_HOPOPTS:
1827                         case IPV6_RTHDR:
1828                         case IPV6_DSTOPTS:
1829                         case IPV6_RTHDRDSTOPTS:
1830                         case IPV6_NEXTHOP:
1831                         {
1832                                 /* new advanced API (RFC3542) */
1833                                 u_char *optbuf;
1834                                 u_char optbuf_storage[MCLBYTES];
1835                                 int optlen;
1836                                 struct ip6_pktopts **optp;
1837
1838                                 /* cannot mix with RFC2292 */
1839                                 if (OPTBIT(IN6P_RFC2292)) {
1840                                         error = EINVAL;
1841                                         break;
1842                                 }
1843
1844                                 /*
1845                                  * We only ensure valsize is not too large
1846                                  * here.  Further validation will be done
1847                                  * later.
1848                                  */
1849                                 error = sooptcopyin(sopt, optbuf_storage,
1850                                     sizeof(optbuf_storage), 0);
1851                                 if (error)
1852                                         break;
1853                                 optlen = sopt->sopt_valsize;
1854                                 optbuf = optbuf_storage;
1855                                 optp = &in6p->in6p_outputopts;
1856                                 error = ip6_pcbopt(optname, optbuf, optlen,
1857                                     optp, (td != NULL) ? td->td_ucred : NULL,
1858                                     uproto);
1859                                 break;
1860                         }
1861 #undef OPTSET
1862
1863                         case IPV6_MULTICAST_IF:
1864                         case IPV6_MULTICAST_HOPS:
1865                         case IPV6_MULTICAST_LOOP:
1866                         case IPV6_JOIN_GROUP:
1867                         case IPV6_LEAVE_GROUP:
1868                         case IPV6_MSFILTER:
1869                         case MCAST_BLOCK_SOURCE:
1870                         case MCAST_UNBLOCK_SOURCE:
1871                         case MCAST_JOIN_GROUP:
1872                         case MCAST_LEAVE_GROUP:
1873                         case MCAST_JOIN_SOURCE_GROUP:
1874                         case MCAST_LEAVE_SOURCE_GROUP:
1875                                 error = ip6_setmoptions(in6p, sopt);
1876                                 break;
1877
1878                         case IPV6_PORTRANGE:
1879                                 error = sooptcopyin(sopt, &optval,
1880                                     sizeof optval, sizeof optval);
1881                                 if (error)
1882                                         break;
1883
1884                                 INP_WLOCK(in6p);
1885                                 switch (optval) {
1886                                 case IPV6_PORTRANGE_DEFAULT:
1887                                         in6p->inp_flags &= ~(INP_LOWPORT);
1888                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1889                                         break;
1890
1891                                 case IPV6_PORTRANGE_HIGH:
1892                                         in6p->inp_flags &= ~(INP_LOWPORT);
1893                                         in6p->inp_flags |= INP_HIGHPORT;
1894                                         break;
1895
1896                                 case IPV6_PORTRANGE_LOW:
1897                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1898                                         in6p->inp_flags |= INP_LOWPORT;
1899                                         break;
1900
1901                                 default:
1902                                         error = EINVAL;
1903                                         break;
1904                                 }
1905                                 INP_WUNLOCK(in6p);
1906                                 break;
1907
1908 #ifdef IPSEC
1909                         case IPV6_IPSEC_POLICY:
1910                         {
1911                                 caddr_t req;
1912                                 struct mbuf *m;
1913
1914                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1915                                         break;
1916                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1917                                         break;
1918                                 req = mtod(m, caddr_t);
1919                                 error = ipsec_set_policy(in6p, optname, req,
1920                                     m->m_len, (sopt->sopt_td != NULL) ?
1921                                     sopt->sopt_td->td_ucred : NULL);
1922                                 m_freem(m);
1923                                 break;
1924                         }
1925 #endif /* IPSEC */
1926
1927                         default:
1928                                 error = ENOPROTOOPT;
1929                                 break;
1930                         }
1931                         break;
1932
1933                 case SOPT_GET:
1934                         switch (optname) {
1935
1936                         case IPV6_2292PKTOPTIONS:
1937 #ifdef IPV6_PKTOPTIONS
1938                         case IPV6_PKTOPTIONS:
1939 #endif
1940                                 /*
1941                                  * RFC3542 (effectively) deprecated the
1942                                  * semantics of the 2292-style pktoptions.
1943                                  * Since it was not reliable in nature (i.e.,
1944                                  * applications had to expect the lack of some
1945                                  * information after all), it would make sense
1946                                  * to simplify this part by always returning
1947                                  * empty data.
1948                                  */
1949                                 sopt->sopt_valsize = 0;
1950                                 break;
1951
1952                         case IPV6_RECVHOPOPTS:
1953                         case IPV6_RECVDSTOPTS:
1954                         case IPV6_RECVRTHDRDSTOPTS:
1955                         case IPV6_UNICAST_HOPS:
1956                         case IPV6_RECVPKTINFO:
1957                         case IPV6_RECVHOPLIMIT:
1958                         case IPV6_RECVRTHDR:
1959                         case IPV6_RECVPATHMTU:
1960
1961                         case IPV6_FAITH:
1962                         case IPV6_V6ONLY:
1963                         case IPV6_PORTRANGE:
1964                         case IPV6_RECVTCLASS:
1965                         case IPV6_AUTOFLOWLABEL:
1966                         case IPV6_BINDANY:
1967                                 switch (optname) {
1968
1969                                 case IPV6_RECVHOPOPTS:
1970                                         optval = OPTBIT(IN6P_HOPOPTS);
1971                                         break;
1972
1973                                 case IPV6_RECVDSTOPTS:
1974                                         optval = OPTBIT(IN6P_DSTOPTS);
1975                                         break;
1976
1977                                 case IPV6_RECVRTHDRDSTOPTS:
1978                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1979                                         break;
1980
1981                                 case IPV6_UNICAST_HOPS:
1982                                         optval = in6p->in6p_hops;
1983                                         break;
1984
1985                                 case IPV6_RECVPKTINFO:
1986                                         optval = OPTBIT(IN6P_PKTINFO);
1987                                         break;
1988
1989                                 case IPV6_RECVHOPLIMIT:
1990                                         optval = OPTBIT(IN6P_HOPLIMIT);
1991                                         break;
1992
1993                                 case IPV6_RECVRTHDR:
1994                                         optval = OPTBIT(IN6P_RTHDR);
1995                                         break;
1996
1997                                 case IPV6_RECVPATHMTU:
1998                                         optval = OPTBIT(IN6P_MTU);
1999                                         break;
2000
2001                                 case IPV6_FAITH:
2002                                         optval = OPTBIT(INP_FAITH);
2003                                         break;
2004
2005                                 case IPV6_V6ONLY:
2006                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
2007                                         break;
2008
2009                                 case IPV6_PORTRANGE:
2010                                     {
2011                                         int flags;
2012                                         flags = in6p->inp_flags;
2013                                         if (flags & INP_HIGHPORT)
2014                                                 optval = IPV6_PORTRANGE_HIGH;
2015                                         else if (flags & INP_LOWPORT)
2016                                                 optval = IPV6_PORTRANGE_LOW;
2017                                         else
2018                                                 optval = 0;
2019                                         break;
2020                                     }
2021                                 case IPV6_RECVTCLASS:
2022                                         optval = OPTBIT(IN6P_TCLASS);
2023                                         break;
2024
2025                                 case IPV6_AUTOFLOWLABEL:
2026                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2027                                         break;
2028
2029                                 case IPV6_BINDANY:
2030                                         optval = OPTBIT(INP_BINDANY);
2031                                         break;
2032                                 }
2033                                 if (error)
2034                                         break;
2035                                 error = sooptcopyout(sopt, &optval,
2036                                         sizeof optval);
2037                                 break;
2038
2039                         case IPV6_PATHMTU:
2040                         {
2041                                 u_long pmtu = 0;
2042                                 struct ip6_mtuinfo mtuinfo;
2043                                 struct route_in6 sro;
2044
2045                                 bzero(&sro, sizeof(sro));
2046
2047                                 if (!(so->so_state & SS_ISCONNECTED))
2048                                         return (ENOTCONN);
2049                                 /*
2050                                  * XXX: we dot not consider the case of source
2051                                  * routing, or optional information to specify
2052                                  * the outgoing interface.
2053                                  */
2054                                 error = ip6_getpmtu(&sro, NULL, NULL,
2055                                     &in6p->in6p_faddr, &pmtu, NULL,
2056                                     so->so_fibnum);
2057                                 if (sro.ro_rt)
2058                                         RTFREE(sro.ro_rt);
2059                                 if (error)
2060                                         break;
2061                                 if (pmtu > IPV6_MAXPACKET)
2062                                         pmtu = IPV6_MAXPACKET;
2063
2064                                 bzero(&mtuinfo, sizeof(mtuinfo));
2065                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2066                                 optdata = (void *)&mtuinfo;
2067                                 optdatalen = sizeof(mtuinfo);
2068                                 error = sooptcopyout(sopt, optdata,
2069                                     optdatalen);
2070                                 break;
2071                         }
2072
2073                         case IPV6_2292PKTINFO:
2074                         case IPV6_2292HOPLIMIT:
2075                         case IPV6_2292HOPOPTS:
2076                         case IPV6_2292RTHDR:
2077                         case IPV6_2292DSTOPTS:
2078                                 switch (optname) {
2079                                 case IPV6_2292PKTINFO:
2080                                         optval = OPTBIT(IN6P_PKTINFO);
2081                                         break;
2082                                 case IPV6_2292HOPLIMIT:
2083                                         optval = OPTBIT(IN6P_HOPLIMIT);
2084                                         break;
2085                                 case IPV6_2292HOPOPTS:
2086                                         optval = OPTBIT(IN6P_HOPOPTS);
2087                                         break;
2088                                 case IPV6_2292RTHDR:
2089                                         optval = OPTBIT(IN6P_RTHDR);
2090                                         break;
2091                                 case IPV6_2292DSTOPTS:
2092                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2093                                         break;
2094                                 }
2095                                 error = sooptcopyout(sopt, &optval,
2096                                     sizeof optval);
2097                                 break;
2098                         case IPV6_PKTINFO:
2099                         case IPV6_HOPOPTS:
2100                         case IPV6_RTHDR:
2101                         case IPV6_DSTOPTS:
2102                         case IPV6_RTHDRDSTOPTS:
2103                         case IPV6_NEXTHOP:
2104                         case IPV6_TCLASS:
2105                         case IPV6_DONTFRAG:
2106                         case IPV6_USE_MIN_MTU:
2107                         case IPV6_PREFER_TEMPADDR:
2108                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
2109                                     optname, sopt);
2110                                 break;
2111
2112                         case IPV6_MULTICAST_IF:
2113                         case IPV6_MULTICAST_HOPS:
2114                         case IPV6_MULTICAST_LOOP:
2115                         case IPV6_MSFILTER:
2116                                 error = ip6_getmoptions(in6p, sopt);
2117                                 break;
2118
2119 #ifdef IPSEC
2120                         case IPV6_IPSEC_POLICY:
2121                           {
2122                                 caddr_t req = NULL;
2123                                 size_t len = 0;
2124                                 struct mbuf *m = NULL;
2125                                 struct mbuf **mp = &m;
2126                                 size_t ovalsize = sopt->sopt_valsize;
2127                                 caddr_t oval = (caddr_t)sopt->sopt_val;
2128
2129                                 error = soopt_getm(sopt, &m); /* XXX */
2130                                 if (error != 0)
2131                                         break;
2132                                 error = soopt_mcopyin(sopt, m); /* XXX */
2133                                 if (error != 0)
2134                                         break;
2135                                 sopt->sopt_valsize = ovalsize;
2136                                 sopt->sopt_val = oval;
2137                                 if (m) {
2138                                         req = mtod(m, caddr_t);
2139                                         len = m->m_len;
2140                                 }
2141                                 error = ipsec_get_policy(in6p, req, len, mp);
2142                                 if (error == 0)
2143                                         error = soopt_mcopyout(sopt, m); /* XXX */
2144                                 if (error == 0 && m)
2145                                         m_freem(m);
2146                                 break;
2147                           }
2148 #endif /* IPSEC */
2149
2150                         default:
2151                                 error = ENOPROTOOPT;
2152                                 break;
2153                         }
2154                         break;
2155                 }
2156         }
2157         return (error);
2158 }
2159
2160 int
2161 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2162 {
2163         int error = 0, optval, optlen;
2164         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2165         struct inpcb *in6p = sotoinpcb(so);
2166         int level, op, optname;
2167
2168         level = sopt->sopt_level;
2169         op = sopt->sopt_dir;
2170         optname = sopt->sopt_name;
2171         optlen = sopt->sopt_valsize;
2172
2173         if (level != IPPROTO_IPV6) {
2174                 return (EINVAL);
2175         }
2176
2177         switch (optname) {
2178         case IPV6_CHECKSUM:
2179                 /*
2180                  * For ICMPv6 sockets, no modification allowed for checksum
2181                  * offset, permit "no change" values to help existing apps.
2182                  *
2183                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2184                  * for an ICMPv6 socket will fail."
2185                  * The current behavior does not meet RFC3542.
2186                  */
2187                 switch (op) {
2188                 case SOPT_SET:
2189                         if (optlen != sizeof(int)) {
2190                                 error = EINVAL;
2191                                 break;
2192                         }
2193                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2194                                             sizeof(optval));
2195                         if (error)
2196                                 break;
2197                         if ((optval % 2) != 0) {
2198                                 /* the API assumes even offset values */
2199                                 error = EINVAL;
2200                         } else if (so->so_proto->pr_protocol ==
2201                             IPPROTO_ICMPV6) {
2202                                 if (optval != icmp6off)
2203                                         error = EINVAL;
2204                         } else
2205                                 in6p->in6p_cksum = optval;
2206                         break;
2207
2208                 case SOPT_GET:
2209                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2210                                 optval = icmp6off;
2211                         else
2212                                 optval = in6p->in6p_cksum;
2213
2214                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2215                         break;
2216
2217                 default:
2218                         error = EINVAL;
2219                         break;
2220                 }
2221                 break;
2222
2223         default:
2224                 error = ENOPROTOOPT;
2225                 break;
2226         }
2227
2228         return (error);
2229 }
2230
2231 /*
2232  * Set up IP6 options in pcb for insertion in output packets or
2233  * specifying behavior of outgoing packets.
2234  */
2235 static int
2236 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2237     struct socket *so, struct sockopt *sopt)
2238 {
2239         struct ip6_pktopts *opt = *pktopt;
2240         int error = 0;
2241         struct thread *td = sopt->sopt_td;
2242
2243         /* turn off any old options. */
2244         if (opt) {
2245 #ifdef DIAGNOSTIC
2246                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2247                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2248                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2249                         printf("ip6_pcbopts: all specified options are cleared.\n");
2250 #endif
2251                 ip6_clearpktopts(opt, -1);
2252         } else
2253                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2254         *pktopt = NULL;
2255
2256         if (!m || m->m_len == 0) {
2257                 /*
2258                  * Only turning off any previous options, regardless of
2259                  * whether the opt is just created or given.
2260                  */
2261                 free(opt, M_IP6OPT);
2262                 return (0);
2263         }
2264
2265         /*  set options specified by user. */
2266         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2267             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2268                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2269                 free(opt, M_IP6OPT);
2270                 return (error);
2271         }
2272         *pktopt = opt;
2273         return (0);
2274 }
2275
2276 /*
2277  * initialize ip6_pktopts.  beware that there are non-zero default values in
2278  * the struct.
2279  */
2280 void
2281 ip6_initpktopts(struct ip6_pktopts *opt)
2282 {
2283
2284         bzero(opt, sizeof(*opt));
2285         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2286         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2287         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2288         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2289 }
2290
2291 static int
2292 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2293     struct ucred *cred, int uproto)
2294 {
2295         struct ip6_pktopts *opt;
2296
2297         if (*pktopt == NULL) {
2298                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2299                     M_WAITOK);
2300                 ip6_initpktopts(*pktopt);
2301         }
2302         opt = *pktopt;
2303
2304         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2305 }
2306
2307 static int
2308 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2309 {
2310         void *optdata = NULL;
2311         int optdatalen = 0;
2312         struct ip6_ext *ip6e;
2313         int error = 0;
2314         struct in6_pktinfo null_pktinfo;
2315         int deftclass = 0, on;
2316         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2317         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2318
2319         switch (optname) {
2320         case IPV6_PKTINFO:
2321                 if (pktopt && pktopt->ip6po_pktinfo)
2322                         optdata = (void *)pktopt->ip6po_pktinfo;
2323                 else {
2324                         /* XXX: we don't have to do this every time... */
2325                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2326                         optdata = (void *)&null_pktinfo;
2327                 }
2328                 optdatalen = sizeof(struct in6_pktinfo);
2329                 break;
2330         case IPV6_TCLASS:
2331                 if (pktopt && pktopt->ip6po_tclass >= 0)
2332                         optdata = (void *)&pktopt->ip6po_tclass;
2333                 else
2334                         optdata = (void *)&deftclass;
2335                 optdatalen = sizeof(int);
2336                 break;
2337         case IPV6_HOPOPTS:
2338                 if (pktopt && pktopt->ip6po_hbh) {
2339                         optdata = (void *)pktopt->ip6po_hbh;
2340                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2341                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2342                 }
2343                 break;
2344         case IPV6_RTHDR:
2345                 if (pktopt && pktopt->ip6po_rthdr) {
2346                         optdata = (void *)pktopt->ip6po_rthdr;
2347                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2348                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2349                 }
2350                 break;
2351         case IPV6_RTHDRDSTOPTS:
2352                 if (pktopt && pktopt->ip6po_dest1) {
2353                         optdata = (void *)pktopt->ip6po_dest1;
2354                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2355                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2356                 }
2357                 break;
2358         case IPV6_DSTOPTS:
2359                 if (pktopt && pktopt->ip6po_dest2) {
2360                         optdata = (void *)pktopt->ip6po_dest2;
2361                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2362                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2363                 }
2364                 break;
2365         case IPV6_NEXTHOP:
2366                 if (pktopt && pktopt->ip6po_nexthop) {
2367                         optdata = (void *)pktopt->ip6po_nexthop;
2368                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2369                 }
2370                 break;
2371         case IPV6_USE_MIN_MTU:
2372                 if (pktopt)
2373                         optdata = (void *)&pktopt->ip6po_minmtu;
2374                 else
2375                         optdata = (void *)&defminmtu;
2376                 optdatalen = sizeof(int);
2377                 break;
2378         case IPV6_DONTFRAG:
2379                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2380                         on = 1;
2381                 else
2382                         on = 0;
2383                 optdata = (void *)&on;
2384                 optdatalen = sizeof(on);
2385                 break;
2386         case IPV6_PREFER_TEMPADDR:
2387                 if (pktopt)
2388                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2389                 else
2390                         optdata = (void *)&defpreftemp;
2391                 optdatalen = sizeof(int);
2392                 break;
2393         default:                /* should not happen */
2394 #ifdef DIAGNOSTIC
2395                 panic("ip6_getpcbopt: unexpected option\n");
2396 #endif
2397                 return (ENOPROTOOPT);
2398         }
2399
2400         error = sooptcopyout(sopt, optdata, optdatalen);
2401
2402         return (error);
2403 }
2404
2405 void
2406 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2407 {
2408         if (pktopt == NULL)
2409                 return;
2410
2411         if (optname == -1 || optname == IPV6_PKTINFO) {
2412                 if (pktopt->ip6po_pktinfo)
2413                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2414                 pktopt->ip6po_pktinfo = NULL;
2415         }
2416         if (optname == -1 || optname == IPV6_HOPLIMIT)
2417                 pktopt->ip6po_hlim = -1;
2418         if (optname == -1 || optname == IPV6_TCLASS)
2419                 pktopt->ip6po_tclass = -1;
2420         if (optname == -1 || optname == IPV6_NEXTHOP) {
2421                 if (pktopt->ip6po_nextroute.ro_rt) {
2422                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2423                         pktopt->ip6po_nextroute.ro_rt = NULL;
2424                 }
2425                 if (pktopt->ip6po_nexthop)
2426                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2427                 pktopt->ip6po_nexthop = NULL;
2428         }
2429         if (optname == -1 || optname == IPV6_HOPOPTS) {
2430                 if (pktopt->ip6po_hbh)
2431                         free(pktopt->ip6po_hbh, M_IP6OPT);
2432                 pktopt->ip6po_hbh = NULL;
2433         }
2434         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2435                 if (pktopt->ip6po_dest1)
2436                         free(pktopt->ip6po_dest1, M_IP6OPT);
2437                 pktopt->ip6po_dest1 = NULL;
2438         }
2439         if (optname == -1 || optname == IPV6_RTHDR) {
2440                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2441                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2442                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2443                 if (pktopt->ip6po_route.ro_rt) {
2444                         RTFREE(pktopt->ip6po_route.ro_rt);
2445                         pktopt->ip6po_route.ro_rt = NULL;
2446                 }
2447         }
2448         if (optname == -1 || optname == IPV6_DSTOPTS) {
2449                 if (pktopt->ip6po_dest2)
2450                         free(pktopt->ip6po_dest2, M_IP6OPT);
2451                 pktopt->ip6po_dest2 = NULL;
2452         }
2453 }
2454
2455 #define PKTOPT_EXTHDRCPY(type) \
2456 do {\
2457         if (src->type) {\
2458                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2459                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2460                 if (dst->type == NULL && canwait == M_NOWAIT)\
2461                         goto bad;\
2462                 bcopy(src->type, dst->type, hlen);\
2463         }\
2464 } while (/*CONSTCOND*/ 0)
2465
2466 static int
2467 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2468 {
2469         if (dst == NULL || src == NULL)  {
2470                 printf("ip6_clearpktopts: invalid argument\n");
2471                 return (EINVAL);
2472         }
2473
2474         dst->ip6po_hlim = src->ip6po_hlim;
2475         dst->ip6po_tclass = src->ip6po_tclass;
2476         dst->ip6po_flags = src->ip6po_flags;
2477         dst->ip6po_minmtu = src->ip6po_minmtu;
2478         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2479         if (src->ip6po_pktinfo) {
2480                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2481                     M_IP6OPT, canwait);
2482                 if (dst->ip6po_pktinfo == NULL)
2483                         goto bad;
2484                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2485         }
2486         if (src->ip6po_nexthop) {
2487                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2488                     M_IP6OPT, canwait);
2489                 if (dst->ip6po_nexthop == NULL)
2490                         goto bad;
2491                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2492                     src->ip6po_nexthop->sa_len);
2493         }
2494         PKTOPT_EXTHDRCPY(ip6po_hbh);
2495         PKTOPT_EXTHDRCPY(ip6po_dest1);
2496         PKTOPT_EXTHDRCPY(ip6po_dest2);
2497         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2498         return (0);
2499
2500   bad:
2501         ip6_clearpktopts(dst, -1);
2502         return (ENOBUFS);
2503 }
2504 #undef PKTOPT_EXTHDRCPY
2505
2506 struct ip6_pktopts *
2507 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2508 {
2509         int error;
2510         struct ip6_pktopts *dst;
2511
2512         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2513         if (dst == NULL)
2514                 return (NULL);
2515         ip6_initpktopts(dst);
2516
2517         if ((error = copypktopts(dst, src, canwait)) != 0) {
2518                 free(dst, M_IP6OPT);
2519                 return (NULL);
2520         }
2521
2522         return (dst);
2523 }
2524
2525 void
2526 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2527 {
2528         if (pktopt == NULL)
2529                 return;
2530
2531         ip6_clearpktopts(pktopt, -1);
2532
2533         free(pktopt, M_IP6OPT);
2534 }
2535
2536 /*
2537  * Set IPv6 outgoing packet options based on advanced API.
2538  */
2539 int
2540 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2541     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2542 {
2543         struct cmsghdr *cm = 0;
2544
2545         if (control == NULL || opt == NULL)
2546                 return (EINVAL);
2547
2548         ip6_initpktopts(opt);
2549         if (stickyopt) {
2550                 int error;
2551
2552                 /*
2553                  * If stickyopt is provided, make a local copy of the options
2554                  * for this particular packet, then override them by ancillary
2555                  * objects.
2556                  * XXX: copypktopts() does not copy the cached route to a next
2557                  * hop (if any).  This is not very good in terms of efficiency,
2558                  * but we can allow this since this option should be rarely
2559                  * used.
2560                  */
2561                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2562                         return (error);
2563         }
2564
2565         /*
2566          * XXX: Currently, we assume all the optional information is stored
2567          * in a single mbuf.
2568          */
2569         if (control->m_next)
2570                 return (EINVAL);
2571
2572         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2573             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2574                 int error;
2575
2576                 if (control->m_len < CMSG_LEN(0))
2577                         return (EINVAL);
2578
2579                 cm = mtod(control, struct cmsghdr *);
2580                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2581                         return (EINVAL);
2582                 if (cm->cmsg_level != IPPROTO_IPV6)
2583                         continue;
2584
2585                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2586                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2587                 if (error)
2588                         return (error);
2589         }
2590
2591         return (0);
2592 }
2593
2594 /*
2595  * Set a particular packet option, as a sticky option or an ancillary data
2596  * item.  "len" can be 0 only when it's a sticky option.
2597  * We have 4 cases of combination of "sticky" and "cmsg":
2598  * "sticky=0, cmsg=0": impossible
2599  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2600  * "sticky=1, cmsg=0": RFC3542 socket option
2601  * "sticky=1, cmsg=1": RFC2292 socket option
2602  */
2603 static int
2604 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2605     struct ucred *cred, int sticky, int cmsg, int uproto)
2606 {
2607         int minmtupolicy, preftemp;
2608         int error;
2609
2610         if (!sticky && !cmsg) {
2611 #ifdef DIAGNOSTIC
2612                 printf("ip6_setpktopt: impossible case\n");
2613 #endif
2614                 return (EINVAL);
2615         }
2616
2617         /*
2618          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2619          * not be specified in the context of RFC3542.  Conversely,
2620          * RFC3542 types should not be specified in the context of RFC2292.
2621          */
2622         if (!cmsg) {
2623                 switch (optname) {
2624                 case IPV6_2292PKTINFO:
2625                 case IPV6_2292HOPLIMIT:
2626                 case IPV6_2292NEXTHOP:
2627                 case IPV6_2292HOPOPTS:
2628                 case IPV6_2292DSTOPTS:
2629                 case IPV6_2292RTHDR:
2630                 case IPV6_2292PKTOPTIONS:
2631                         return (ENOPROTOOPT);
2632                 }
2633         }
2634         if (sticky && cmsg) {
2635                 switch (optname) {
2636                 case IPV6_PKTINFO:
2637                 case IPV6_HOPLIMIT:
2638                 case IPV6_NEXTHOP:
2639                 case IPV6_HOPOPTS:
2640                 case IPV6_DSTOPTS:
2641                 case IPV6_RTHDRDSTOPTS:
2642                 case IPV6_RTHDR:
2643                 case IPV6_USE_MIN_MTU:
2644                 case IPV6_DONTFRAG:
2645                 case IPV6_TCLASS:
2646                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2647                         return (ENOPROTOOPT);
2648                 }
2649         }
2650
2651         switch (optname) {
2652         case IPV6_2292PKTINFO:
2653         case IPV6_PKTINFO:
2654         {
2655                 struct ifnet *ifp = NULL;
2656                 struct in6_pktinfo *pktinfo;
2657
2658                 if (len != sizeof(struct in6_pktinfo))
2659                         return (EINVAL);
2660
2661                 pktinfo = (struct in6_pktinfo *)buf;
2662
2663                 /*
2664                  * An application can clear any sticky IPV6_PKTINFO option by
2665                  * doing a "regular" setsockopt with ipi6_addr being
2666                  * in6addr_any and ipi6_ifindex being zero.
2667                  * [RFC 3542, Section 6]
2668                  */
2669                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2670                     pktinfo->ipi6_ifindex == 0 &&
2671                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2672                         ip6_clearpktopts(opt, optname);
2673                         break;
2674                 }
2675
2676                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2677                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2678                         return (EINVAL);
2679                 }
2680
2681                 /* validate the interface index if specified. */
2682                 if (pktinfo->ipi6_ifindex > V_if_index ||
2683                     pktinfo->ipi6_ifindex < 0) {
2684                          return (ENXIO);
2685                 }
2686                 if (pktinfo->ipi6_ifindex) {
2687                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2688                         if (ifp == NULL)
2689                                 return (ENXIO);
2690                 }
2691
2692                 /*
2693                  * We store the address anyway, and let in6_selectsrc()
2694                  * validate the specified address.  This is because ipi6_addr
2695                  * may not have enough information about its scope zone, and
2696                  * we may need additional information (such as outgoing
2697                  * interface or the scope zone of a destination address) to
2698                  * disambiguate the scope.
2699                  * XXX: the delay of the validation may confuse the
2700                  * application when it is used as a sticky option.
2701                  */
2702                 if (opt->ip6po_pktinfo == NULL) {
2703                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2704                             M_IP6OPT, M_NOWAIT);
2705                         if (opt->ip6po_pktinfo == NULL)
2706                                 return (ENOBUFS);
2707                 }
2708                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2709                 break;
2710         }
2711
2712         case IPV6_2292HOPLIMIT:
2713         case IPV6_HOPLIMIT:
2714         {
2715                 int *hlimp;
2716
2717                 /*
2718                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2719                  * to simplify the ordering among hoplimit options.
2720                  */
2721                 if (optname == IPV6_HOPLIMIT && sticky)
2722                         return (ENOPROTOOPT);
2723
2724                 if (len != sizeof(int))
2725                         return (EINVAL);
2726                 hlimp = (int *)buf;
2727                 if (*hlimp < -1 || *hlimp > 255)
2728                         return (EINVAL);
2729
2730                 opt->ip6po_hlim = *hlimp;
2731                 break;
2732         }
2733
2734         case IPV6_TCLASS:
2735         {
2736                 int tclass;
2737
2738                 if (len != sizeof(int))
2739                         return (EINVAL);
2740                 tclass = *(int *)buf;
2741                 if (tclass < -1 || tclass > 255)
2742                         return (EINVAL);
2743
2744                 opt->ip6po_tclass = tclass;
2745                 break;
2746         }
2747
2748         case IPV6_2292NEXTHOP:
2749         case IPV6_NEXTHOP:
2750                 if (cred != NULL) {
2751                         error = priv_check_cred(cred,
2752                             PRIV_NETINET_SETHDROPTS, 0);
2753                         if (error)
2754                                 return (error);
2755                 }
2756
2757                 if (len == 0) { /* just remove the option */
2758                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2759                         break;
2760                 }
2761
2762                 /* check if cmsg_len is large enough for sa_len */
2763                 if (len < sizeof(struct sockaddr) || len < *buf)
2764                         return (EINVAL);
2765
2766                 switch (((struct sockaddr *)buf)->sa_family) {
2767                 case AF_INET6:
2768                 {
2769                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2770                         int error;
2771
2772                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2773                                 return (EINVAL);
2774
2775                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2776                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2777                                 return (EINVAL);
2778                         }
2779                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2780                             != 0) {
2781                                 return (error);
2782                         }
2783                         break;
2784                 }
2785                 case AF_LINK:   /* should eventually be supported */
2786                 default:
2787                         return (EAFNOSUPPORT);
2788                 }
2789
2790                 /* turn off the previous option, then set the new option. */
2791                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2792                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2793                 if (opt->ip6po_nexthop == NULL)
2794                         return (ENOBUFS);
2795                 bcopy(buf, opt->ip6po_nexthop, *buf);
2796                 break;
2797
2798         case IPV6_2292HOPOPTS:
2799         case IPV6_HOPOPTS:
2800         {
2801                 struct ip6_hbh *hbh;
2802                 int hbhlen;
2803
2804                 /*
2805                  * XXX: We don't allow a non-privileged user to set ANY HbH
2806                  * options, since per-option restriction has too much
2807                  * overhead.
2808                  */
2809                 if (cred != NULL) {
2810                         error = priv_check_cred(cred,
2811                             PRIV_NETINET_SETHDROPTS, 0);
2812                         if (error)
2813                                 return (error);
2814                 }
2815
2816                 if (len == 0) {
2817                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2818                         break;  /* just remove the option */
2819                 }
2820
2821                 /* message length validation */
2822                 if (len < sizeof(struct ip6_hbh))
2823                         return (EINVAL);
2824                 hbh = (struct ip6_hbh *)buf;
2825                 hbhlen = (hbh->ip6h_len + 1) << 3;
2826                 if (len != hbhlen)
2827                         return (EINVAL);
2828
2829                 /* turn off the previous option, then set the new option. */
2830                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2831                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2832                 if (opt->ip6po_hbh == NULL)
2833                         return (ENOBUFS);
2834                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2835
2836                 break;
2837         }
2838
2839         case IPV6_2292DSTOPTS:
2840         case IPV6_DSTOPTS:
2841         case IPV6_RTHDRDSTOPTS:
2842         {
2843                 struct ip6_dest *dest, **newdest = NULL;
2844                 int destlen;
2845
2846                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2847                         error = priv_check_cred(cred,
2848                             PRIV_NETINET_SETHDROPTS, 0);
2849                         if (error)
2850                                 return (error);
2851                 }
2852
2853                 if (len == 0) {
2854                         ip6_clearpktopts(opt, optname);
2855                         break;  /* just remove the option */
2856                 }
2857
2858                 /* message length validation */
2859                 if (len < sizeof(struct ip6_dest))
2860                         return (EINVAL);
2861                 dest = (struct ip6_dest *)buf;
2862                 destlen = (dest->ip6d_len + 1) << 3;
2863                 if (len != destlen)
2864                         return (EINVAL);
2865
2866                 /*
2867                  * Determine the position that the destination options header
2868                  * should be inserted; before or after the routing header.
2869                  */
2870                 switch (optname) {
2871                 case IPV6_2292DSTOPTS:
2872                         /*
2873                          * The old advacned API is ambiguous on this point.
2874                          * Our approach is to determine the position based
2875                          * according to the existence of a routing header.
2876                          * Note, however, that this depends on the order of the
2877                          * extension headers in the ancillary data; the 1st
2878                          * part of the destination options header must appear
2879                          * before the routing header in the ancillary data,
2880                          * too.
2881                          * RFC3542 solved the ambiguity by introducing
2882                          * separate ancillary data or option types.
2883                          */
2884                         if (opt->ip6po_rthdr == NULL)
2885                                 newdest = &opt->ip6po_dest1;
2886                         else
2887                                 newdest = &opt->ip6po_dest2;
2888                         break;
2889                 case IPV6_RTHDRDSTOPTS:
2890                         newdest = &opt->ip6po_dest1;
2891                         break;
2892                 case IPV6_DSTOPTS:
2893                         newdest = &opt->ip6po_dest2;
2894                         break;
2895                 }
2896
2897                 /* turn off the previous option, then set the new option. */
2898                 ip6_clearpktopts(opt, optname);
2899                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2900                 if (*newdest == NULL)
2901                         return (ENOBUFS);
2902                 bcopy(dest, *newdest, destlen);
2903
2904                 break;
2905         }
2906
2907         case IPV6_2292RTHDR:
2908         case IPV6_RTHDR:
2909         {
2910                 struct ip6_rthdr *rth;
2911                 int rthlen;
2912
2913                 if (len == 0) {
2914                         ip6_clearpktopts(opt, IPV6_RTHDR);
2915                         break;  /* just remove the option */
2916                 }
2917
2918                 /* message length validation */
2919                 if (len < sizeof(struct ip6_rthdr))
2920                         return (EINVAL);
2921                 rth = (struct ip6_rthdr *)buf;
2922                 rthlen = (rth->ip6r_len + 1) << 3;
2923                 if (len != rthlen)
2924                         return (EINVAL);
2925
2926                 switch (rth->ip6r_type) {
2927                 case IPV6_RTHDR_TYPE_0:
2928                         if (rth->ip6r_len == 0) /* must contain one addr */
2929                                 return (EINVAL);
2930                         if (rth->ip6r_len % 2) /* length must be even */
2931                                 return (EINVAL);
2932                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2933                                 return (EINVAL);
2934                         break;
2935                 default:
2936                         return (EINVAL);        /* not supported */
2937                 }
2938
2939                 /* turn off the previous option */
2940                 ip6_clearpktopts(opt, IPV6_RTHDR);
2941                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2942                 if (opt->ip6po_rthdr == NULL)
2943                         return (ENOBUFS);
2944                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2945
2946                 break;
2947         }
2948
2949         case IPV6_USE_MIN_MTU:
2950                 if (len != sizeof(int))
2951                         return (EINVAL);
2952                 minmtupolicy = *(int *)buf;
2953                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2954                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
2955                     minmtupolicy != IP6PO_MINMTU_ALL) {
2956                         return (EINVAL);
2957                 }
2958                 opt->ip6po_minmtu = minmtupolicy;
2959                 break;
2960
2961         case IPV6_DONTFRAG:
2962                 if (len != sizeof(int))
2963                         return (EINVAL);
2964
2965                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2966                         /*
2967                          * we ignore this option for TCP sockets.
2968                          * (RFC3542 leaves this case unspecified.)
2969                          */
2970                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2971                 } else
2972                         opt->ip6po_flags |= IP6PO_DONTFRAG;
2973                 break;
2974
2975         case IPV6_PREFER_TEMPADDR:
2976                 if (len != sizeof(int))
2977                         return (EINVAL);
2978                 preftemp = *(int *)buf;
2979                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2980                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2981                     preftemp != IP6PO_TEMPADDR_PREFER) {
2982                         return (EINVAL);
2983                 }
2984                 opt->ip6po_prefer_tempaddr = preftemp;
2985                 break;
2986
2987         default:
2988                 return (ENOPROTOOPT);
2989         } /* end of switch */
2990
2991         return (0);
2992 }
2993
2994 /*
2995  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2996  * packet to the input queue of a specified interface.  Note that this
2997  * calls the output routine of the loopback "driver", but with an interface
2998  * pointer that might NOT be &loif -- easier than replicating that code here.
2999  */
3000 void
3001 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
3002 {
3003         struct mbuf *copym;
3004         struct ip6_hdr *ip6;
3005
3006         copym = m_copy(m, 0, M_COPYALL);
3007         if (copym == NULL)
3008                 return;
3009
3010         /*
3011          * Make sure to deep-copy IPv6 header portion in case the data
3012          * is in an mbuf cluster, so that we can safely override the IPv6
3013          * header portion later.
3014          */
3015         if ((copym->m_flags & M_EXT) != 0 ||
3016             copym->m_len < sizeof(struct ip6_hdr)) {
3017                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
3018                 if (copym == NULL)
3019                         return;
3020         }
3021
3022 #ifdef DIAGNOSTIC
3023         if (copym->m_len < sizeof(*ip6)) {
3024                 m_freem(copym);
3025                 return;
3026         }
3027 #endif
3028
3029         ip6 = mtod(copym, struct ip6_hdr *);
3030         /*
3031          * clear embedded scope identifiers if necessary.
3032          * in6_clearscope will touch the addresses only when necessary.
3033          */
3034         in6_clearscope(&ip6->ip6_src);
3035         in6_clearscope(&ip6->ip6_dst);
3036
3037         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
3038 }
3039
3040 /*
3041  * Chop IPv6 header off from the payload.
3042  */
3043 static int
3044 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3045 {
3046         struct mbuf *mh;
3047         struct ip6_hdr *ip6;
3048
3049         ip6 = mtod(m, struct ip6_hdr *);
3050         if (m->m_len > sizeof(*ip6)) {
3051                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
3052                 if (mh == 0) {
3053                         m_freem(m);
3054                         return ENOBUFS;
3055                 }
3056                 M_MOVE_PKTHDR(mh, m);
3057                 MH_ALIGN(mh, sizeof(*ip6));
3058                 m->m_len -= sizeof(*ip6);
3059                 m->m_data += sizeof(*ip6);
3060                 mh->m_next = m;
3061                 m = mh;
3062                 m->m_len = sizeof(*ip6);
3063                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3064         }
3065         exthdrs->ip6e_ip6 = m;
3066         return 0;
3067 }
3068
3069 /*
3070  * Compute IPv6 extension header length.
3071  */
3072 int
3073 ip6_optlen(struct inpcb *in6p)
3074 {
3075         int len;
3076
3077         if (!in6p->in6p_outputopts)
3078                 return 0;
3079
3080         len = 0;
3081 #define elen(x) \
3082     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3083
3084         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3085         if (in6p->in6p_outputopts->ip6po_rthdr)
3086                 /* dest1 is valid with rthdr only */
3087                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3088         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3089         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3090         return len;
3091 #undef elen
3092 }