xref: /NextBSD/sys/netinet6/ip6_output.c (revision 37e74d4f6151b6fae3b07141f988985cb55f2dfc)
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 #include "opt_rss.h"
73 
74 #include <sys/param.h>
75 #include <sys/kernel.h>
76 #include <sys/malloc.h>
77 #include <sys/mbuf.h>
78 #include <sys/errno.h>
79 #include <sys/priv.h>
80 #include <sys/proc.h>
81 #include <sys/protosw.h>
82 #include <sys/socket.h>
83 #include <sys/socketvar.h>
84 #include <sys/syslog.h>
85 #include <sys/ucred.h>
86 
87 #include <machine/in_cksum.h>
88 
89 #include <net/if.h>
90 #include <net/if_var.h>
91 #include <net/netisr.h>
92 #include <net/route.h>
93 #include <net/pfil.h>
94 #include <net/rss_config.h>
95 #include <net/vnet.h>
96 
97 #include <netinet/in.h>
98 #include <netinet/in_var.h>
99 #include <netinet/ip_var.h>
100 #include <netinet6/in6_fib.h>
101 #include <netinet6/in6_var.h>
102 #include <netinet/ip6.h>
103 #include <netinet/icmp6.h>
104 #include <netinet6/ip6_var.h>
105 #include <netinet/in_pcb.h>
106 #include <netinet/tcp_var.h>
107 #include <netinet6/nd6.h>
108 #include <netinet6/in6_rss.h>
109 
110 #ifdef IPSEC
111 #include <netipsec/ipsec.h>
112 #include <netipsec/ipsec6.h>
113 #include <netipsec/key.h>
114 #include <netinet6/ip6_ipsec.h>
115 #endif /* IPSEC */
116 #ifdef SCTP
117 #include <netinet/sctp.h>
118 #include <netinet/sctp_crc32.h>
119 #endif
120 
121 #include <netinet6/ip6protosw.h>
122 #include <netinet6/scope6_var.h>
123 
124 #ifdef FLOWTABLE
125 #include <net/flowtable.h>
126 #endif
127 
128 extern int in6_mcast_loop;
129 
130 struct ip6_exthdrs {
131 	struct mbuf *ip6e_ip6;
132 	struct mbuf *ip6e_hbh;
133 	struct mbuf *ip6e_dest1;
134 	struct mbuf *ip6e_rthdr;
135 	struct mbuf *ip6e_dest2;
136 };
137 
138 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
139 			   struct ucred *, int);
140 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
141 	struct socket *, struct sockopt *);
142 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
143 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
144 	struct ucred *, int, int, int);
145 
146 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
147 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
148 	struct ip6_frag **);
149 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
150 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
151 static int ip6_getpmtu(struct route_in6 *, int,
152 	struct ifnet *, struct in6_addr *, u_long *, int *, u_int);
153 static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
154 	u_long *, int *);
155 static int ip6_getpmtu_ctl(u_int, struct in6_addr *, u_long *);
156 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
157 
158 
159 /*
160  * Make an extension header from option data.  hp is the source, and
161  * mp is the destination.
162  */
163 #define MAKE_EXTHDR(hp, mp)						\
164     do {								\
165 	if (hp) {							\
166 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
167 		error = ip6_copyexthdr((mp), (caddr_t)(hp),		\
168 		    ((eh)->ip6e_len + 1) << 3);				\
169 		if (error)						\
170 			goto freehdrs;					\
171 	}								\
172     } while (/*CONSTCOND*/ 0)
173 
174 /*
175  * Form a chain of extension headers.
176  * m is the extension header mbuf
177  * mp is the previous mbuf in the chain
178  * p is the next header
179  * i is the type of option.
180  */
181 #define MAKE_CHAIN(m, mp, p, i)\
182     do {\
183 	if (m) {\
184 		if (!hdrsplit) \
185 			panic("assumption failed: hdr not split"); \
186 		*mtod((m), u_char *) = *(p);\
187 		*(p) = (i);\
188 		p = mtod((m), u_char *);\
189 		(m)->m_next = (mp)->m_next;\
190 		(mp)->m_next = (m);\
191 		(mp) = (m);\
192 	}\
193     } while (/*CONSTCOND*/ 0)
194 
195 void
in6_delayed_cksum(struct mbuf * m,uint32_t plen,u_short offset)196 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
197 {
198 	u_short csum;
199 
200 	csum = in_cksum_skip(m, offset + plen, offset);
201 	if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
202 		csum = 0xffff;
203 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
204 
205 	if (offset + sizeof(u_short) > m->m_len) {
206 		printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
207 		    "csum_flags=%b\n", __func__, m->m_len, plen, offset,
208 		    (int)m->m_pkthdr.csum_flags, CSUM_BITS);
209 		/*
210 		 * XXX this should not happen, but if it does, the correct
211 		 * behavior may be to insert the checksum in the appropriate
212 		 * next mbuf in the chain.
213 		 */
214 		return;
215 	}
216 	*(u_short *)(m->m_data + offset) = csum;
217 }
218 
219 int
ip6_fragment(struct ifnet * ifp,struct mbuf * m0,int hlen,u_char nextproto,int mtu,uint32_t id)220 ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
221     int mtu, uint32_t id)
222 {
223 	struct mbuf *m, **mnext, *m_frgpart;
224 	struct ip6_hdr *ip6, *mhip6;
225 	struct ip6_frag *ip6f;
226 	int off;
227 	int error;
228 	int tlen = m0->m_pkthdr.len;
229 
230 	m = m0;
231 	ip6 = mtod(m, struct ip6_hdr *);
232 	mnext = &m->m_nextpkt;
233 
234 	for (off = hlen; off < tlen; off += mtu) {
235 		m = m_gethdr(M_NOWAIT, MT_DATA);
236 		if (!m) {
237 			IP6STAT_INC(ip6s_odropped);
238 			return (ENOBUFS);
239 		}
240 		m->m_flags = m0->m_flags & M_COPYFLAGS;
241 		*mnext = m;
242 		mnext = &m->m_nextpkt;
243 		m->m_data += max_linkhdr;
244 		mhip6 = mtod(m, struct ip6_hdr *);
245 		*mhip6 = *ip6;
246 		m->m_len = sizeof(*mhip6);
247 		error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
248 		if (error) {
249 			IP6STAT_INC(ip6s_odropped);
250 			return (error);
251 		}
252 		ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
253 		if (off + mtu >= tlen)
254 			mtu = tlen - off;
255 		else
256 			ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
257 		mhip6->ip6_plen = htons((u_short)(mtu + hlen +
258 		    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
259 		if ((m_frgpart = m_copy(m0, off, mtu)) == 0) {
260 			IP6STAT_INC(ip6s_odropped);
261 			return (ENOBUFS);
262 		}
263 		m_cat(m, m_frgpart);
264 		m->m_pkthdr.len = mtu + hlen + sizeof(*ip6f);
265 		m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
266 		m->m_pkthdr.rcvif = NULL;
267 		ip6f->ip6f_reserved = 0;
268 		ip6f->ip6f_ident = id;
269 		ip6f->ip6f_nxt = nextproto;
270 		IP6STAT_INC(ip6s_ofragments);
271 		in6_ifstat_inc(ifp, ifs6_out_fragcreat);
272 	}
273 
274 	return (0);
275 }
276 
277 /*
278  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
279  * header (with pri, len, nxt, hlim, src, dst).
280  * This function may modify ver and hlim only.
281  * The mbuf chain containing the packet will be freed.
282  * The mbuf opt, if present, will not be freed.
283  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
284  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
285  * then result of route lookup is stored in ro->ro_rt.
286  *
287  * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
288  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
289  * which is rt_mtu.
290  *
291  * ifpp - XXX: just for statistics
292  */
293 /*
294  * XXX TODO: no flowid is assigned for outbound flows?
295  */
296 int
ip6_output(struct mbuf * m0,struct ip6_pktopts * opt,struct route_in6 * ro,int flags,struct ip6_moptions * im6o,struct ifnet ** ifpp,struct inpcb * inp)297 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
298     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
299     struct ifnet **ifpp, struct inpcb *inp)
300 {
301 	struct ip6_hdr *ip6;
302 	struct ifnet *ifp, *origifp;
303 	struct mbuf *m = m0;
304 	struct mbuf *mprev = NULL;
305 	int hlen, tlen, len;
306 	struct route_in6 ip6route;
307 	struct rtentry *rt = NULL;
308 	struct sockaddr_in6 *dst, src_sa, dst_sa;
309 	struct in6_addr odst;
310 	int error = 0;
311 	struct in6_ifaddr *ia = NULL;
312 	u_long mtu;
313 	int alwaysfrag, dontfrag;
314 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
315 	struct ip6_exthdrs exthdrs;
316 	struct in6_addr finaldst, src0, dst0;
317 	u_int32_t zone;
318 	struct route_in6 *ro_pmtu = NULL;
319 	int hdrsplit = 0;
320 	int sw_csum, tso;
321 	int needfiblookup;
322 	uint32_t fibnum;
323 	struct m_tag *fwd_tag = NULL;
324 	uint32_t id;
325 
326 	ip6 = mtod(m, struct ip6_hdr *);
327 	if (ip6 == NULL) {
328 		printf ("ip6 is NULL");
329 		goto bad;
330 	}
331 
332 	if (inp != NULL) {
333 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
334 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
335 			/* unconditionally set flowid */
336 			m->m_pkthdr.flowid = inp->inp_flowid;
337 			M_HASHTYPE_SET(m, inp->inp_flowtype);
338 		}
339 	}
340 
341 	finaldst = ip6->ip6_dst;
342 	bzero(&exthdrs, sizeof(exthdrs));
343 	if (opt) {
344 		/* Hop-by-Hop options header */
345 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
346 		/* Destination options header(1st part) */
347 		if (opt->ip6po_rthdr) {
348 			/*
349 			 * Destination options header(1st part)
350 			 * This only makes sense with a routing header.
351 			 * See Section 9.2 of RFC 3542.
352 			 * Disabling this part just for MIP6 convenience is
353 			 * a bad idea.  We need to think carefully about a
354 			 * way to make the advanced API coexist with MIP6
355 			 * options, which might automatically be inserted in
356 			 * the kernel.
357 			 */
358 			MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
359 		}
360 		/* Routing header */
361 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
362 		/* Destination options header(2nd part) */
363 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
364 	}
365 
366 #ifdef IPSEC
367 	/*
368 	 * IPSec checking which handles several cases.
369 	 * FAST IPSEC: We re-injected the packet.
370 	 * XXX: need scope argument.
371 	 */
372 	switch(ip6_ipsec_output(&m, inp, &error))
373 	{
374 	case 1:                 /* Bad packet */
375 		goto freehdrs;
376 	case -1:                /* IPSec done */
377 		goto done;
378 	case 0:                 /* No IPSec */
379 	default:
380 		break;
381 	}
382 #endif /* IPSEC */
383 
384 	/*
385 	 * Calculate the total length of the extension header chain.
386 	 * Keep the length of the unfragmentable part for fragmentation.
387 	 */
388 	optlen = 0;
389 	if (exthdrs.ip6e_hbh)
390 		optlen += exthdrs.ip6e_hbh->m_len;
391 	if (exthdrs.ip6e_dest1)
392 		optlen += exthdrs.ip6e_dest1->m_len;
393 	if (exthdrs.ip6e_rthdr)
394 		optlen += exthdrs.ip6e_rthdr->m_len;
395 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
396 
397 	/* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
398 	if (exthdrs.ip6e_dest2)
399 		optlen += exthdrs.ip6e_dest2->m_len;
400 
401 	/*
402 	 * If there is at least one extension header,
403 	 * separate IP6 header from the payload.
404 	 */
405 	if (optlen && !hdrsplit) {
406 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
407 			m = NULL;
408 			goto freehdrs;
409 		}
410 		m = exthdrs.ip6e_ip6;
411 		hdrsplit++;
412 	}
413 
414 	/* adjust pointer */
415 	ip6 = mtod(m, struct ip6_hdr *);
416 
417 	/* adjust mbuf packet header length */
418 	m->m_pkthdr.len += optlen;
419 	plen = m->m_pkthdr.len - sizeof(*ip6);
420 
421 	/* If this is a jumbo payload, insert a jumbo payload option. */
422 	if (plen > IPV6_MAXPACKET) {
423 		if (!hdrsplit) {
424 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
425 				m = NULL;
426 				goto freehdrs;
427 			}
428 			m = exthdrs.ip6e_ip6;
429 			hdrsplit++;
430 		}
431 		/* adjust pointer */
432 		ip6 = mtod(m, struct ip6_hdr *);
433 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
434 			goto freehdrs;
435 		ip6->ip6_plen = 0;
436 	} else
437 		ip6->ip6_plen = htons(plen);
438 
439 	/*
440 	 * Concatenate headers and fill in next header fields.
441 	 * Here we have, on "m"
442 	 *	IPv6 payload
443 	 * and we insert headers accordingly.  Finally, we should be getting:
444 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
445 	 *
446 	 * during the header composing process, "m" points to IPv6 header.
447 	 * "mprev" points to an extension header prior to esp.
448 	 */
449 	u_char *nexthdrp = &ip6->ip6_nxt;
450 	mprev = m;
451 
452 	/*
453 	 * we treat dest2 specially.  this makes IPsec processing
454 	 * much easier.  the goal here is to make mprev point the
455 	 * mbuf prior to dest2.
456 	 *
457 	 * result: IPv6 dest2 payload
458 	 * m and mprev will point to IPv6 header.
459 	 */
460 	if (exthdrs.ip6e_dest2) {
461 		if (!hdrsplit)
462 			panic("assumption failed: hdr not split");
463 		exthdrs.ip6e_dest2->m_next = m->m_next;
464 		m->m_next = exthdrs.ip6e_dest2;
465 		*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
466 		ip6->ip6_nxt = IPPROTO_DSTOPTS;
467 	}
468 
469 	/*
470 	 * result: IPv6 hbh dest1 rthdr dest2 payload
471 	 * m will point to IPv6 header.  mprev will point to the
472 	 * extension header prior to dest2 (rthdr in the above case).
473 	 */
474 	MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
475 	MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
476 		   IPPROTO_DSTOPTS);
477 	MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
478 		   IPPROTO_ROUTING);
479 
480 	/*
481 	 * If there is a routing header, discard the packet.
482 	 */
483 	if (exthdrs.ip6e_rthdr) {
484 		 error = EINVAL;
485 		 goto bad;
486 	}
487 
488 	/* Source address validation */
489 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
490 	    (flags & IPV6_UNSPECSRC) == 0) {
491 		error = EOPNOTSUPP;
492 		IP6STAT_INC(ip6s_badscope);
493 		goto bad;
494 	}
495 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
496 		error = EOPNOTSUPP;
497 		IP6STAT_INC(ip6s_badscope);
498 		goto bad;
499 	}
500 
501 	IP6STAT_INC(ip6s_localout);
502 
503 	/*
504 	 * Route packet.
505 	 */
506 	if (ro == 0) {
507 		ro = &ip6route;
508 		bzero((caddr_t)ro, sizeof(*ro));
509 	}
510 	ro_pmtu = ro;
511 	if (opt && opt->ip6po_rthdr)
512 		ro = &opt->ip6po_route;
513 	dst = (struct sockaddr_in6 *)&ro->ro_dst;
514 #ifdef FLOWTABLE
515 	if (ro->ro_rt == NULL)
516 		(void )flowtable_lookup(AF_INET6, m, (struct route *)ro);
517 #endif
518 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
519 again:
520 	/*
521 	 * if specified, try to fill in the traffic class field.
522 	 * do not override if a non-zero value is already set.
523 	 * we check the diffserv field and the ecn field separately.
524 	 */
525 	if (opt && opt->ip6po_tclass >= 0) {
526 		int mask = 0;
527 
528 		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
529 			mask |= 0xfc;
530 		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
531 			mask |= 0x03;
532 		if (mask != 0)
533 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
534 	}
535 
536 	/* fill in or override the hop limit field, if necessary. */
537 	if (opt && opt->ip6po_hlim != -1)
538 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
539 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
540 		if (im6o != NULL)
541 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
542 		else
543 			ip6->ip6_hlim = V_ip6_defmcasthlim;
544 	}
545 
546 	/* adjust pointer */
547 	ip6 = mtod(m, struct ip6_hdr *);
548 
549 	if (ro->ro_rt && fwd_tag == NULL) {
550 		rt = ro->ro_rt;
551 		ifp = ro->ro_rt->rt_ifp;
552 	} else {
553 		if (fwd_tag == NULL) {
554 			bzero(&dst_sa, sizeof(dst_sa));
555 			dst_sa.sin6_family = AF_INET6;
556 			dst_sa.sin6_len = sizeof(dst_sa);
557 			dst_sa.sin6_addr = ip6->ip6_dst;
558 		}
559 		error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
560 		    &rt, fibnum);
561 		if (error != 0) {
562 			if (ifp != NULL)
563 				in6_ifstat_inc(ifp, ifs6_out_discard);
564 			goto bad;
565 		}
566 	}
567 	if (rt == NULL) {
568 		/*
569 		 * If in6_selectroute() does not return a route entry,
570 		 * dst may not have been updated.
571 		 */
572 		*dst = dst_sa;	/* XXX */
573 	}
574 
575 	/*
576 	 * then rt (for unicast) and ifp must be non-NULL valid values.
577 	 */
578 	if ((flags & IPV6_FORWARDING) == 0) {
579 		/* XXX: the FORWARDING flag can be set for mrouting. */
580 		in6_ifstat_inc(ifp, ifs6_out_request);
581 	}
582 	if (rt != NULL) {
583 		ia = (struct in6_ifaddr *)(rt->rt_ifa);
584 		counter_u64_add(rt->rt_pksent, 1);
585 	}
586 
587 
588 	/*
589 	 * The outgoing interface must be in the zone of source and
590 	 * destination addresses.
591 	 */
592 	origifp = ifp;
593 
594 	src0 = ip6->ip6_src;
595 	if (in6_setscope(&src0, origifp, &zone))
596 		goto badscope;
597 	bzero(&src_sa, sizeof(src_sa));
598 	src_sa.sin6_family = AF_INET6;
599 	src_sa.sin6_len = sizeof(src_sa);
600 	src_sa.sin6_addr = ip6->ip6_src;
601 	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
602 		goto badscope;
603 
604 	dst0 = ip6->ip6_dst;
605 	if (in6_setscope(&dst0, origifp, &zone))
606 		goto badscope;
607 	/* re-initialize to be sure */
608 	bzero(&dst_sa, sizeof(dst_sa));
609 	dst_sa.sin6_family = AF_INET6;
610 	dst_sa.sin6_len = sizeof(dst_sa);
611 	dst_sa.sin6_addr = ip6->ip6_dst;
612 	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
613 		goto badscope;
614 	}
615 
616 	/* We should use ia_ifp to support the case of
617 	 * sending packets to an address of our own.
618 	 */
619 	if (ia != NULL && ia->ia_ifp)
620 		ifp = ia->ia_ifp;
621 
622 	/* scope check is done. */
623 	goto routefound;
624 
625   badscope:
626 	IP6STAT_INC(ip6s_badscope);
627 	in6_ifstat_inc(origifp, ifs6_out_discard);
628 	if (error == 0)
629 		error = EHOSTUNREACH; /* XXX */
630 	goto bad;
631 
632   routefound:
633 	if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
634 		if (opt && opt->ip6po_nextroute.ro_rt) {
635 			/*
636 			 * The nexthop is explicitly specified by the
637 			 * application.  We assume the next hop is an IPv6
638 			 * address.
639 			 */
640 			dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
641 		}
642 		else if ((rt->rt_flags & RTF_GATEWAY))
643 			dst = (struct sockaddr_in6 *)rt->rt_gateway;
644 	}
645 
646 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
647 		m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
648 	} else {
649 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
650 		in6_ifstat_inc(ifp, ifs6_out_mcast);
651 		/*
652 		 * Confirm that the outgoing interface supports multicast.
653 		 */
654 		if (!(ifp->if_flags & IFF_MULTICAST)) {
655 			IP6STAT_INC(ip6s_noroute);
656 			in6_ifstat_inc(ifp, ifs6_out_discard);
657 			error = ENETUNREACH;
658 			goto bad;
659 		}
660 		if ((im6o == NULL && in6_mcast_loop) ||
661 		    (im6o && im6o->im6o_multicast_loop)) {
662 			/*
663 			 * Loop back multicast datagram if not expressly
664 			 * forbidden to do so, even if we have not joined
665 			 * the address; protocols will filter it later,
666 			 * thus deferring a hash lookup and lock acquisition
667 			 * at the expense of an m_copym().
668 			 */
669 			ip6_mloopback(ifp, m);
670 		} else {
671 			/*
672 			 * If we are acting as a multicast router, perform
673 			 * multicast forwarding as if the packet had just
674 			 * arrived on the interface to which we are about
675 			 * to send.  The multicast forwarding function
676 			 * recursively calls this function, using the
677 			 * IPV6_FORWARDING flag to prevent infinite recursion.
678 			 *
679 			 * Multicasts that are looped back by ip6_mloopback(),
680 			 * above, will be forwarded by the ip6_input() routine,
681 			 * if necessary.
682 			 */
683 			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
684 				/*
685 				 * XXX: ip6_mforward expects that rcvif is NULL
686 				 * when it is called from the originating path.
687 				 * However, it may not always be the case.
688 				 */
689 				m->m_pkthdr.rcvif = NULL;
690 				if (ip6_mforward(ip6, ifp, m) != 0) {
691 					m_freem(m);
692 					goto done;
693 				}
694 			}
695 		}
696 		/*
697 		 * Multicasts with a hoplimit of zero may be looped back,
698 		 * above, but must not be transmitted on a network.
699 		 * Also, multicasts addressed to the loopback interface
700 		 * are not sent -- the above call to ip6_mloopback() will
701 		 * loop back a copy if this host actually belongs to the
702 		 * destination group on the loopback interface.
703 		 */
704 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
705 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
706 			m_freem(m);
707 			goto done;
708 		}
709 	}
710 
711 	/*
712 	 * Fill the outgoing inteface to tell the upper layer
713 	 * to increment per-interface statistics.
714 	 */
715 	if (ifpp)
716 		*ifpp = ifp;
717 
718 	/* Determine path MTU. */
719 	if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &finaldst, &mtu,
720 	    &alwaysfrag, fibnum)) != 0)
721 		goto bad;
722 
723 	/*
724 	 * The caller of this function may specify to use the minimum MTU
725 	 * in some cases.
726 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
727 	 * setting.  The logic is a bit complicated; by default, unicast
728 	 * packets will follow path MTU while multicast packets will be sent at
729 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
730 	 * including unicast ones will be sent at the minimum MTU.  Multicast
731 	 * packets will always be sent at the minimum MTU unless
732 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
733 	 * See RFC 3542 for more details.
734 	 */
735 	if (mtu > IPV6_MMTU) {
736 		if ((flags & IPV6_MINMTU))
737 			mtu = IPV6_MMTU;
738 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
739 			mtu = IPV6_MMTU;
740 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
741 			 (opt == NULL ||
742 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
743 			mtu = IPV6_MMTU;
744 		}
745 	}
746 
747 	/*
748 	 * clear embedded scope identifiers if necessary.
749 	 * in6_clearscope will touch the addresses only when necessary.
750 	 */
751 	in6_clearscope(&ip6->ip6_src);
752 	in6_clearscope(&ip6->ip6_dst);
753 
754 	/*
755 	 * If the outgoing packet contains a hop-by-hop options header,
756 	 * it must be examined and processed even by the source node.
757 	 * (RFC 2460, section 4.)
758 	 */
759 	if (exthdrs.ip6e_hbh) {
760 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
761 		u_int32_t dummy; /* XXX unused */
762 		u_int32_t plen = 0; /* XXX: ip6_process will check the value */
763 
764 #ifdef DIAGNOSTIC
765 		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
766 			panic("ip6e_hbh is not contiguous");
767 #endif
768 		/*
769 		 *  XXX: if we have to send an ICMPv6 error to the sender,
770 		 *       we need the M_LOOP flag since icmp6_error() expects
771 		 *       the IPv6 and the hop-by-hop options header are
772 		 *       contiguous unless the flag is set.
773 		 */
774 		m->m_flags |= M_LOOP;
775 		m->m_pkthdr.rcvif = ifp;
776 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
777 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
778 		    &dummy, &plen) < 0) {
779 			/* m was already freed at this point */
780 			error = EINVAL;/* better error? */
781 			goto done;
782 		}
783 		m->m_flags &= ~M_LOOP; /* XXX */
784 		m->m_pkthdr.rcvif = NULL;
785 	}
786 
787 	/* Jump over all PFIL processing if hooks are not active. */
788 	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
789 		goto passout;
790 
791 	odst = ip6->ip6_dst;
792 	/* Run through list of hooks for output packets. */
793 	error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
794 	if (error != 0 || m == NULL)
795 		goto done;
796 	ip6 = mtod(m, struct ip6_hdr *);
797 
798 	needfiblookup = 0;
799 	/* See if destination IP address was changed by packet filter. */
800 	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
801 		m->m_flags |= M_SKIP_FIREWALL;
802 		/* If destination is now ourself drop to ip6_input(). */
803 		if (in6_localip(&ip6->ip6_dst)) {
804 			m->m_flags |= M_FASTFWD_OURS;
805 			if (m->m_pkthdr.rcvif == NULL)
806 				m->m_pkthdr.rcvif = V_loif;
807 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
808 				m->m_pkthdr.csum_flags |=
809 				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
810 				m->m_pkthdr.csum_data = 0xffff;
811 			}
812 #ifdef SCTP
813 			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
814 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
815 #endif
816 			error = netisr_queue(NETISR_IPV6, m);
817 			goto done;
818 		} else
819 			needfiblookup = 1; /* Redo the routing table lookup. */
820 	}
821 	/* See if fib was changed by packet filter. */
822 	if (fibnum != M_GETFIB(m)) {
823 		m->m_flags |= M_SKIP_FIREWALL;
824 		fibnum = M_GETFIB(m);
825 		RO_RTFREE(ro);
826 		needfiblookup = 1;
827 	}
828 	if (needfiblookup)
829 		goto again;
830 
831 	/* See if local, if yes, send it to netisr. */
832 	if (m->m_flags & M_FASTFWD_OURS) {
833 		if (m->m_pkthdr.rcvif == NULL)
834 			m->m_pkthdr.rcvif = V_loif;
835 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
836 			m->m_pkthdr.csum_flags |=
837 			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
838 			m->m_pkthdr.csum_data = 0xffff;
839 		}
840 #ifdef SCTP
841 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
842 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
843 #endif
844 		error = netisr_queue(NETISR_IPV6, m);
845 		goto done;
846 	}
847 	/* Or forward to some other address? */
848 	if ((m->m_flags & M_IP6_NEXTHOP) &&
849 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
850 		dst = (struct sockaddr_in6 *)&ro->ro_dst;
851 		bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
852 		m->m_flags |= M_SKIP_FIREWALL;
853 		m->m_flags &= ~M_IP6_NEXTHOP;
854 		m_tag_delete(m, fwd_tag);
855 		goto again;
856 	}
857 
858 passout:
859 	/*
860 	 * Send the packet to the outgoing interface.
861 	 * If necessary, do IPv6 fragmentation before sending.
862 	 *
863 	 * the logic here is rather complex:
864 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
865 	 * 1-a:	send as is if tlen <= path mtu
866 	 * 1-b:	fragment if tlen > path mtu
867 	 *
868 	 * 2: if user asks us not to fragment (dontfrag == 1)
869 	 * 2-a:	send as is if tlen <= interface mtu
870 	 * 2-b:	error if tlen > interface mtu
871 	 *
872 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
873 	 *	always fragment
874 	 *
875 	 * 4: if dontfrag == 1 && alwaysfrag == 1
876 	 *	error, as we cannot handle this conflicting request
877 	 */
878 	sw_csum = m->m_pkthdr.csum_flags;
879 	if (!hdrsplit) {
880 		tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
881 		sw_csum &= ~ifp->if_hwassist;
882 	} else
883 		tso = 0;
884 	/*
885 	 * If we added extension headers, we will not do TSO and calculate the
886 	 * checksums ourselves for now.
887 	 * XXX-BZ  Need a framework to know when the NIC can handle it, even
888 	 * with ext. hdrs.
889 	 */
890 	if (sw_csum & CSUM_DELAY_DATA_IPV6) {
891 		sw_csum &= ~CSUM_DELAY_DATA_IPV6;
892 		in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
893 	}
894 #ifdef SCTP
895 	if (sw_csum & CSUM_SCTP_IPV6) {
896 		sw_csum &= ~CSUM_SCTP_IPV6;
897 		sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
898 	}
899 #endif
900 	m->m_pkthdr.csum_flags &= ifp->if_hwassist;
901 	tlen = m->m_pkthdr.len;
902 
903 	if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
904 		dontfrag = 1;
905 	else
906 		dontfrag = 0;
907 	if (dontfrag && alwaysfrag) {	/* case 4 */
908 		/* conflicting request - can't transmit */
909 		error = EMSGSIZE;
910 		goto bad;
911 	}
912 	if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {	/* case 2-b */
913 		/*
914 		 * Even if the DONTFRAG option is specified, we cannot send the
915 		 * packet when the data length is larger than the MTU of the
916 		 * outgoing interface.
917 		 * Notify the error by sending IPV6_PATHMTU ancillary data if
918 		 * application wanted to know the MTU value. Also return an
919 		 * error code (this is not described in the API spec).
920 		 */
921 		if (inp != NULL)
922 			ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
923 		error = EMSGSIZE;
924 		goto bad;
925 	}
926 
927 	/*
928 	 * transmit packet without fragmentation
929 	 */
930 	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* case 1-a and 2-a */
931 		struct in6_ifaddr *ia6;
932 
933 		ip6 = mtod(m, struct ip6_hdr *);
934 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
935 		if (ia6) {
936 			/* Record statistics for this interface address. */
937 			counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
938 			counter_u64_add(ia6->ia_ifa.ifa_obytes,
939 			    m->m_pkthdr.len);
940 			ifa_free(&ia6->ia_ifa);
941 		}
942 
943 		error = nd6_output_ifp(ifp, origifp, m, dst, ro);
944 		goto done;
945 	}
946 
947 	/*
948 	 * try to fragment the packet.  case 1-b and 3
949 	 */
950 	if (mtu < IPV6_MMTU) {
951 		/* path MTU cannot be less than IPV6_MMTU */
952 		error = EMSGSIZE;
953 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
954 		goto bad;
955 	} else if (ip6->ip6_plen == 0) {
956 		/* jumbo payload cannot be fragmented */
957 		error = EMSGSIZE;
958 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
959 		goto bad;
960 	} else {
961 		u_char nextproto;
962 
963 		/*
964 		 * Too large for the destination or interface;
965 		 * fragment if possible.
966 		 * Must be able to put at least 8 bytes per fragment.
967 		 */
968 		hlen = unfragpartlen;
969 		if (mtu > IPV6_MAXPACKET)
970 			mtu = IPV6_MAXPACKET;
971 
972 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
973 		if (len < 8) {
974 			error = EMSGSIZE;
975 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
976 			goto bad;
977 		}
978 
979 		/*
980 		 * If the interface will not calculate checksums on
981 		 * fragmented packets, then do it here.
982 		 * XXX-BZ handle the hw offloading case.  Need flags.
983 		 */
984 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
985 			in6_delayed_cksum(m, plen, hlen);
986 			m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
987 		}
988 #ifdef SCTP
989 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
990 			sctp_delayed_cksum(m, hlen);
991 			m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
992 		}
993 #endif
994 		/*
995 		 * Change the next header field of the last header in the
996 		 * unfragmentable part.
997 		 */
998 		if (exthdrs.ip6e_rthdr) {
999 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1000 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1001 		} else if (exthdrs.ip6e_dest1) {
1002 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1003 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1004 		} else if (exthdrs.ip6e_hbh) {
1005 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1006 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1007 		} else {
1008 			nextproto = ip6->ip6_nxt;
1009 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
1010 		}
1011 
1012 		/*
1013 		 * Loop through length of segment after first fragment,
1014 		 * make new header and copy data of each part and link onto
1015 		 * chain.
1016 		 */
1017 		m0 = m;
1018 		id = htonl(ip6_randomid());
1019 		if ((error = ip6_fragment(ifp, m, hlen, nextproto, len, id)))
1020 			goto sendorfree;
1021 
1022 		in6_ifstat_inc(ifp, ifs6_out_fragok);
1023 	}
1024 
1025 	/*
1026 	 * Remove leading garbages.
1027 	 */
1028 sendorfree:
1029 	m = m0->m_nextpkt;
1030 	m0->m_nextpkt = 0;
1031 	m_freem(m0);
1032 	for (m0 = m; m; m = m0) {
1033 		m0 = m->m_nextpkt;
1034 		m->m_nextpkt = 0;
1035 		if (error == 0) {
1036 			/* Record statistics for this interface address. */
1037 			if (ia) {
1038 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1039 				counter_u64_add(ia->ia_ifa.ifa_obytes,
1040 				    m->m_pkthdr.len);
1041 			}
1042 			error = nd6_output_ifp(ifp, origifp, m, dst, ro);
1043 		} else
1044 			m_freem(m);
1045 	}
1046 
1047 	if (error == 0)
1048 		IP6STAT_INC(ip6s_fragmented);
1049 
1050 done:
1051 	if (ro == &ip6route)
1052 		RO_RTFREE(ro);
1053 	return (error);
1054 
1055 freehdrs:
1056 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
1057 	m_freem(exthdrs.ip6e_dest1);
1058 	m_freem(exthdrs.ip6e_rthdr);
1059 	m_freem(exthdrs.ip6e_dest2);
1060 	/* FALLTHROUGH */
1061 bad:
1062 	if (m)
1063 		m_freem(m);
1064 	goto done;
1065 }
1066 
1067 static int
ip6_copyexthdr(struct mbuf ** mp,caddr_t hdr,int hlen)1068 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1069 {
1070 	struct mbuf *m;
1071 
1072 	if (hlen > MCLBYTES)
1073 		return (ENOBUFS); /* XXX */
1074 
1075 	if (hlen > MLEN)
1076 		m = m_getcl(M_NOWAIT, MT_DATA, 0);
1077 	else
1078 		m = m_get(M_NOWAIT, MT_DATA);
1079 	if (m == NULL)
1080 		return (ENOBUFS);
1081 	m->m_len = hlen;
1082 	if (hdr)
1083 		bcopy(hdr, mtod(m, caddr_t), hlen);
1084 
1085 	*mp = m;
1086 	return (0);
1087 }
1088 
1089 /*
1090  * Insert jumbo payload option.
1091  */
1092 static int
ip6_insert_jumboopt(struct ip6_exthdrs * exthdrs,u_int32_t plen)1093 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1094 {
1095 	struct mbuf *mopt;
1096 	u_char *optbuf;
1097 	u_int32_t v;
1098 
1099 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1100 
1101 	/*
1102 	 * If there is no hop-by-hop options header, allocate new one.
1103 	 * If there is one but it doesn't have enough space to store the
1104 	 * jumbo payload option, allocate a cluster to store the whole options.
1105 	 * Otherwise, use it to store the options.
1106 	 */
1107 	if (exthdrs->ip6e_hbh == 0) {
1108 		mopt = m_get(M_NOWAIT, MT_DATA);
1109 		if (mopt == NULL)
1110 			return (ENOBUFS);
1111 		mopt->m_len = JUMBOOPTLEN;
1112 		optbuf = mtod(mopt, u_char *);
1113 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1114 		exthdrs->ip6e_hbh = mopt;
1115 	} else {
1116 		struct ip6_hbh *hbh;
1117 
1118 		mopt = exthdrs->ip6e_hbh;
1119 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1120 			/*
1121 			 * XXX assumption:
1122 			 * - exthdrs->ip6e_hbh is not referenced from places
1123 			 *   other than exthdrs.
1124 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1125 			 */
1126 			int oldoptlen = mopt->m_len;
1127 			struct mbuf *n;
1128 
1129 			/*
1130 			 * XXX: give up if the whole (new) hbh header does
1131 			 * not fit even in an mbuf cluster.
1132 			 */
1133 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1134 				return (ENOBUFS);
1135 
1136 			/*
1137 			 * As a consequence, we must always prepare a cluster
1138 			 * at this point.
1139 			 */
1140 			n = m_getcl(M_NOWAIT, MT_DATA, 0);
1141 			if (n == NULL)
1142 				return (ENOBUFS);
1143 			n->m_len = oldoptlen + JUMBOOPTLEN;
1144 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1145 			    oldoptlen);
1146 			optbuf = mtod(n, caddr_t) + oldoptlen;
1147 			m_freem(mopt);
1148 			mopt = exthdrs->ip6e_hbh = n;
1149 		} else {
1150 			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1151 			mopt->m_len += JUMBOOPTLEN;
1152 		}
1153 		optbuf[0] = IP6OPT_PADN;
1154 		optbuf[1] = 1;
1155 
1156 		/*
1157 		 * Adjust the header length according to the pad and
1158 		 * the jumbo payload option.
1159 		 */
1160 		hbh = mtod(mopt, struct ip6_hbh *);
1161 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1162 	}
1163 
1164 	/* fill in the option. */
1165 	optbuf[2] = IP6OPT_JUMBO;
1166 	optbuf[3] = 4;
1167 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1168 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1169 
1170 	/* finally, adjust the packet header length */
1171 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1172 
1173 	return (0);
1174 #undef JUMBOOPTLEN
1175 }
1176 
1177 /*
1178  * Insert fragment header and copy unfragmentable header portions.
1179  */
1180 static int
ip6_insertfraghdr(struct mbuf * m0,struct mbuf * m,int hlen,struct ip6_frag ** frghdrp)1181 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1182     struct ip6_frag **frghdrp)
1183 {
1184 	struct mbuf *n, *mlast;
1185 
1186 	if (hlen > sizeof(struct ip6_hdr)) {
1187 		n = m_copym(m0, sizeof(struct ip6_hdr),
1188 		    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1189 		if (n == 0)
1190 			return (ENOBUFS);
1191 		m->m_next = n;
1192 	} else
1193 		n = m;
1194 
1195 	/* Search for the last mbuf of unfragmentable part. */
1196 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1197 		;
1198 
1199 	if (M_WRITABLE(mlast) &&
1200 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1201 		/* use the trailing space of the last mbuf for the fragment hdr */
1202 		*frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1203 		    mlast->m_len);
1204 		mlast->m_len += sizeof(struct ip6_frag);
1205 		m->m_pkthdr.len += sizeof(struct ip6_frag);
1206 	} else {
1207 		/* allocate a new mbuf for the fragment header */
1208 		struct mbuf *mfrg;
1209 
1210 		mfrg = m_get(M_NOWAIT, MT_DATA);
1211 		if (mfrg == NULL)
1212 			return (ENOBUFS);
1213 		mfrg->m_len = sizeof(struct ip6_frag);
1214 		*frghdrp = mtod(mfrg, struct ip6_frag *);
1215 		mlast->m_next = mfrg;
1216 	}
1217 
1218 	return (0);
1219 }
1220 
1221 /*
1222  * Calculates IPv6 path mtu for destination @dst.
1223  * Resulting MTU is stored in @mtup.
1224  *
1225  * Returns 0 on success.
1226  */
1227 static int
ip6_getpmtu_ctl(u_int fibnum,struct in6_addr * dst,u_long * mtup)1228 ip6_getpmtu_ctl(u_int fibnum, struct in6_addr *dst, u_long *mtup)
1229 {
1230 	struct nhop6_extended nh6;
1231 	struct in6_addr kdst;
1232 	uint32_t scopeid;
1233 	struct ifnet *ifp;
1234 	u_long mtu;
1235 	int error;
1236 
1237 	in6_splitscope(dst, &kdst, &scopeid);
1238 	if (fib6_lookup_nh_ext(fibnum, &kdst, scopeid, NHR_REF, 0, &nh6) != 0)
1239 		return (EHOSTUNREACH);
1240 
1241 	ifp = nh6.nh_ifp;
1242 	mtu = nh6.nh_mtu;
1243 
1244 	error = ip6_calcmtu(ifp, dst, mtu, mtup, NULL);
1245 	fib6_free_nh_ext(fibnum, &nh6);
1246 
1247 	return (error);
1248 }
1249 
1250 /*
1251  * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1252  * and cached data in @ro_pmtu.
1253  * MTU from (successful) route lookup is saved (along with dst)
1254  * inside @ro_pmtu to avoid subsequent route lookups after packet
1255  * filter processing.
1256  *
1257  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1258  * Returns 0 on success.
1259  */
1260 static int
ip6_getpmtu(struct route_in6 * ro_pmtu,int do_lookup,struct ifnet * ifp,struct in6_addr * dst,u_long * mtup,int * alwaysfragp,u_int fibnum)1261 ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1262     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1263     int *alwaysfragp, u_int fibnum)
1264 {
1265 	struct nhop6_basic nh6;
1266 	struct in6_addr kdst;
1267 	uint32_t scopeid;
1268 	struct sockaddr_in6 *sa6_dst;
1269 	u_long mtu;
1270 
1271 	mtu = 0;
1272 	if (do_lookup) {
1273 
1274 		/*
1275 		 * Here ro_pmtu has final destination address, while
1276 		 * ro might represent immediate destination.
1277 		 * Use ro_pmtu destination since mtu might differ.
1278 		 */
1279 		sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1280 		if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1281 			ro_pmtu->ro_mtu = 0;
1282 
1283 		if (ro_pmtu->ro_mtu == 0) {
1284 			bzero(sa6_dst, sizeof(*sa6_dst));
1285 			sa6_dst->sin6_family = AF_INET6;
1286 			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1287 			sa6_dst->sin6_addr = *dst;
1288 
1289 			in6_splitscope(dst, &kdst, &scopeid);
1290 			if (fib6_lookup_nh_basic(fibnum, &kdst, scopeid, 0, 0,
1291 			    &nh6) == 0)
1292 				ro_pmtu->ro_mtu = nh6.nh_mtu;
1293 		}
1294 
1295 		mtu = ro_pmtu->ro_mtu;
1296 	}
1297 
1298 	if (ro_pmtu->ro_rt)
1299 		mtu = ro_pmtu->ro_rt->rt_mtu;
1300 
1301 	return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp));
1302 }
1303 
1304 /*
1305  * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1306  * hostcache data for @dst.
1307  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1308  *
1309  * Returns 0 on success.
1310  */
1311 static int
ip6_calcmtu(struct ifnet * ifp,const struct in6_addr * dst,u_long rt_mtu,u_long * mtup,int * alwaysfragp)1312 ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1313     u_long *mtup, int *alwaysfragp)
1314 {
1315 	u_long mtu = 0;
1316 	int alwaysfrag = 0;
1317 	int error = 0;
1318 
1319 	if (rt_mtu > 0) {
1320 		u_int32_t ifmtu;
1321 		struct in_conninfo inc;
1322 
1323 		bzero(&inc, sizeof(inc));
1324 		inc.inc_flags |= INC_ISIPV6;
1325 		inc.inc6_faddr = *dst;
1326 
1327 		ifmtu = IN6_LINKMTU(ifp);
1328 		mtu = tcp_hc_getmtu(&inc);
1329 		if (mtu)
1330 			mtu = min(mtu, rt_mtu);
1331 		else
1332 			mtu = rt_mtu;
1333 		if (mtu == 0)
1334 			mtu = ifmtu;
1335 		else if (mtu < IPV6_MMTU) {
1336 			/*
1337 			 * RFC2460 section 5, last paragraph:
1338 			 * if we record ICMPv6 too big message with
1339 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1340 			 * or smaller, with framgent header attached.
1341 			 * (fragment header is needed regardless from the
1342 			 * packet size, for translators to identify packets)
1343 			 */
1344 			alwaysfrag = 1;
1345 			mtu = IPV6_MMTU;
1346 		}
1347 	} else if (ifp) {
1348 		mtu = IN6_LINKMTU(ifp);
1349 	} else
1350 		error = EHOSTUNREACH; /* XXX */
1351 
1352 	*mtup = mtu;
1353 	if (alwaysfragp)
1354 		*alwaysfragp = alwaysfrag;
1355 	return (error);
1356 }
1357 
1358 /*
1359  * IP6 socket option processing.
1360  */
1361 int
ip6_ctloutput(struct socket * so,struct sockopt * sopt)1362 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1363 {
1364 	int optdatalen, uproto;
1365 	void *optdata;
1366 	struct inpcb *in6p = sotoinpcb(so);
1367 	int error, optval;
1368 	int level, op, optname;
1369 	int optlen;
1370 	struct thread *td;
1371 #ifdef	RSS
1372 	uint32_t rss_bucket;
1373 	int retval;
1374 #endif
1375 
1376 	level = sopt->sopt_level;
1377 	op = sopt->sopt_dir;
1378 	optname = sopt->sopt_name;
1379 	optlen = sopt->sopt_valsize;
1380 	td = sopt->sopt_td;
1381 	error = 0;
1382 	optval = 0;
1383 	uproto = (int)so->so_proto->pr_protocol;
1384 
1385 	if (level != IPPROTO_IPV6) {
1386 		error = EINVAL;
1387 
1388 		if (sopt->sopt_level == SOL_SOCKET &&
1389 		    sopt->sopt_dir == SOPT_SET) {
1390 			switch (sopt->sopt_name) {
1391 			case SO_REUSEADDR:
1392 				INP_WLOCK(in6p);
1393 				if ((so->so_options & SO_REUSEADDR) != 0)
1394 					in6p->inp_flags2 |= INP_REUSEADDR;
1395 				else
1396 					in6p->inp_flags2 &= ~INP_REUSEADDR;
1397 				INP_WUNLOCK(in6p);
1398 				error = 0;
1399 				break;
1400 			case SO_REUSEPORT:
1401 				INP_WLOCK(in6p);
1402 				if ((so->so_options & SO_REUSEPORT) != 0)
1403 					in6p->inp_flags2 |= INP_REUSEPORT;
1404 				else
1405 					in6p->inp_flags2 &= ~INP_REUSEPORT;
1406 				INP_WUNLOCK(in6p);
1407 				error = 0;
1408 				break;
1409 			case SO_SETFIB:
1410 				INP_WLOCK(in6p);
1411 				in6p->inp_inc.inc_fibnum = so->so_fibnum;
1412 				INP_WUNLOCK(in6p);
1413 				error = 0;
1414 				break;
1415 			default:
1416 				break;
1417 			}
1418 		}
1419 	} else {		/* level == IPPROTO_IPV6 */
1420 		switch (op) {
1421 
1422 		case SOPT_SET:
1423 			switch (optname) {
1424 			case IPV6_2292PKTOPTIONS:
1425 #ifdef IPV6_PKTOPTIONS
1426 			case IPV6_PKTOPTIONS:
1427 #endif
1428 			{
1429 				struct mbuf *m;
1430 
1431 				error = soopt_getm(sopt, &m); /* XXX */
1432 				if (error != 0)
1433 					break;
1434 				error = soopt_mcopyin(sopt, m); /* XXX */
1435 				if (error != 0)
1436 					break;
1437 				error = ip6_pcbopts(&in6p->in6p_outputopts,
1438 						    m, so, sopt);
1439 				m_freem(m); /* XXX */
1440 				break;
1441 			}
1442 
1443 			/*
1444 			 * Use of some Hop-by-Hop options or some
1445 			 * Destination options, might require special
1446 			 * privilege.  That is, normal applications
1447 			 * (without special privilege) might be forbidden
1448 			 * from setting certain options in outgoing packets,
1449 			 * and might never see certain options in received
1450 			 * packets. [RFC 2292 Section 6]
1451 			 * KAME specific note:
1452 			 *  KAME prevents non-privileged users from sending or
1453 			 *  receiving ANY hbh/dst options in order to avoid
1454 			 *  overhead of parsing options in the kernel.
1455 			 */
1456 			case IPV6_RECVHOPOPTS:
1457 			case IPV6_RECVDSTOPTS:
1458 			case IPV6_RECVRTHDRDSTOPTS:
1459 				if (td != NULL) {
1460 					error = priv_check(td,
1461 					    PRIV_NETINET_SETHDROPTS);
1462 					if (error)
1463 						break;
1464 				}
1465 				/* FALLTHROUGH */
1466 			case IPV6_UNICAST_HOPS:
1467 			case IPV6_HOPLIMIT:
1468 
1469 			case IPV6_RECVPKTINFO:
1470 			case IPV6_RECVHOPLIMIT:
1471 			case IPV6_RECVRTHDR:
1472 			case IPV6_RECVPATHMTU:
1473 			case IPV6_RECVTCLASS:
1474 			case IPV6_RECVFLOWID:
1475 #ifdef	RSS
1476 			case IPV6_RECVRSSBUCKETID:
1477 #endif
1478 			case IPV6_V6ONLY:
1479 			case IPV6_AUTOFLOWLABEL:
1480 			case IPV6_BINDANY:
1481 			case IPV6_BINDMULTI:
1482 #ifdef	RSS
1483 			case IPV6_RSS_LISTEN_BUCKET:
1484 #endif
1485 				if (optname == IPV6_BINDANY && td != NULL) {
1486 					error = priv_check(td,
1487 					    PRIV_NETINET_BINDANY);
1488 					if (error)
1489 						break;
1490 				}
1491 
1492 				if (optlen != sizeof(int)) {
1493 					error = EINVAL;
1494 					break;
1495 				}
1496 				error = sooptcopyin(sopt, &optval,
1497 					sizeof optval, sizeof optval);
1498 				if (error)
1499 					break;
1500 				switch (optname) {
1501 
1502 				case IPV6_UNICAST_HOPS:
1503 					if (optval < -1 || optval >= 256)
1504 						error = EINVAL;
1505 					else {
1506 						/* -1 = kernel default */
1507 						in6p->in6p_hops = optval;
1508 						if ((in6p->inp_vflag &
1509 						     INP_IPV4) != 0)
1510 							in6p->inp_ip_ttl = optval;
1511 					}
1512 					break;
1513 #define OPTSET(bit) \
1514 do { \
1515 	INP_WLOCK(in6p); \
1516 	if (optval) \
1517 		in6p->inp_flags |= (bit); \
1518 	else \
1519 		in6p->inp_flags &= ~(bit); \
1520 	INP_WUNLOCK(in6p); \
1521 } while (/*CONSTCOND*/ 0)
1522 #define OPTSET2292(bit) \
1523 do { \
1524 	INP_WLOCK(in6p); \
1525 	in6p->inp_flags |= IN6P_RFC2292; \
1526 	if (optval) \
1527 		in6p->inp_flags |= (bit); \
1528 	else \
1529 		in6p->inp_flags &= ~(bit); \
1530 	INP_WUNLOCK(in6p); \
1531 } while (/*CONSTCOND*/ 0)
1532 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1533 
1534 #define OPTSET2(bit, val) do {						\
1535 	INP_WLOCK(in6p);						\
1536 	if (val)							\
1537 		in6p->inp_flags2 |= bit;				\
1538 	else								\
1539 		in6p->inp_flags2 &= ~bit;				\
1540 	INP_WUNLOCK(in6p);						\
1541 } while (0)
1542 #define OPTBIT2(bit) (in6p->inp_flags2 & (bit) ? 1 : 0)
1543 
1544 				case IPV6_RECVPKTINFO:
1545 					/* cannot mix with RFC2292 */
1546 					if (OPTBIT(IN6P_RFC2292)) {
1547 						error = EINVAL;
1548 						break;
1549 					}
1550 					OPTSET(IN6P_PKTINFO);
1551 					break;
1552 
1553 				case IPV6_HOPLIMIT:
1554 				{
1555 					struct ip6_pktopts **optp;
1556 
1557 					/* cannot mix with RFC2292 */
1558 					if (OPTBIT(IN6P_RFC2292)) {
1559 						error = EINVAL;
1560 						break;
1561 					}
1562 					optp = &in6p->in6p_outputopts;
1563 					error = ip6_pcbopt(IPV6_HOPLIMIT,
1564 					    (u_char *)&optval, sizeof(optval),
1565 					    optp, (td != NULL) ? td->td_ucred :
1566 					    NULL, uproto);
1567 					break;
1568 				}
1569 
1570 				case IPV6_RECVHOPLIMIT:
1571 					/* cannot mix with RFC2292 */
1572 					if (OPTBIT(IN6P_RFC2292)) {
1573 						error = EINVAL;
1574 						break;
1575 					}
1576 					OPTSET(IN6P_HOPLIMIT);
1577 					break;
1578 
1579 				case IPV6_RECVHOPOPTS:
1580 					/* cannot mix with RFC2292 */
1581 					if (OPTBIT(IN6P_RFC2292)) {
1582 						error = EINVAL;
1583 						break;
1584 					}
1585 					OPTSET(IN6P_HOPOPTS);
1586 					break;
1587 
1588 				case IPV6_RECVDSTOPTS:
1589 					/* cannot mix with RFC2292 */
1590 					if (OPTBIT(IN6P_RFC2292)) {
1591 						error = EINVAL;
1592 						break;
1593 					}
1594 					OPTSET(IN6P_DSTOPTS);
1595 					break;
1596 
1597 				case IPV6_RECVRTHDRDSTOPTS:
1598 					/* cannot mix with RFC2292 */
1599 					if (OPTBIT(IN6P_RFC2292)) {
1600 						error = EINVAL;
1601 						break;
1602 					}
1603 					OPTSET(IN6P_RTHDRDSTOPTS);
1604 					break;
1605 
1606 				case IPV6_RECVRTHDR:
1607 					/* cannot mix with RFC2292 */
1608 					if (OPTBIT(IN6P_RFC2292)) {
1609 						error = EINVAL;
1610 						break;
1611 					}
1612 					OPTSET(IN6P_RTHDR);
1613 					break;
1614 
1615 				case IPV6_RECVPATHMTU:
1616 					/*
1617 					 * We ignore this option for TCP
1618 					 * sockets.
1619 					 * (RFC3542 leaves this case
1620 					 * unspecified.)
1621 					 */
1622 					if (uproto != IPPROTO_TCP)
1623 						OPTSET(IN6P_MTU);
1624 					break;
1625 
1626 				case IPV6_RECVFLOWID:
1627 					OPTSET2(INP_RECVFLOWID, optval);
1628 					break;
1629 
1630 #ifdef	RSS
1631 				case IPV6_RECVRSSBUCKETID:
1632 					OPTSET2(INP_RECVRSSBUCKETID, optval);
1633 					break;
1634 #endif
1635 
1636 				case IPV6_V6ONLY:
1637 					/*
1638 					 * make setsockopt(IPV6_V6ONLY)
1639 					 * available only prior to bind(2).
1640 					 * see ipng mailing list, Jun 22 2001.
1641 					 */
1642 					if (in6p->inp_lport ||
1643 					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1644 						error = EINVAL;
1645 						break;
1646 					}
1647 					OPTSET(IN6P_IPV6_V6ONLY);
1648 					if (optval)
1649 						in6p->inp_vflag &= ~INP_IPV4;
1650 					else
1651 						in6p->inp_vflag |= INP_IPV4;
1652 					break;
1653 				case IPV6_RECVTCLASS:
1654 					/* cannot mix with RFC2292 XXX */
1655 					if (OPTBIT(IN6P_RFC2292)) {
1656 						error = EINVAL;
1657 						break;
1658 					}
1659 					OPTSET(IN6P_TCLASS);
1660 					break;
1661 				case IPV6_AUTOFLOWLABEL:
1662 					OPTSET(IN6P_AUTOFLOWLABEL);
1663 					break;
1664 
1665 				case IPV6_BINDANY:
1666 					OPTSET(INP_BINDANY);
1667 					break;
1668 
1669 				case IPV6_BINDMULTI:
1670 					OPTSET2(INP_BINDMULTI, optval);
1671 					break;
1672 #ifdef	RSS
1673 				case IPV6_RSS_LISTEN_BUCKET:
1674 					if ((optval >= 0) &&
1675 					    (optval < rss_getnumbuckets())) {
1676 						in6p->inp_rss_listen_bucket = optval;
1677 						OPTSET2(INP_RSS_BUCKET_SET, 1);
1678 					} else {
1679 						error = EINVAL;
1680 					}
1681 					break;
1682 #endif
1683 				}
1684 				break;
1685 
1686 			case IPV6_TCLASS:
1687 			case IPV6_DONTFRAG:
1688 			case IPV6_USE_MIN_MTU:
1689 			case IPV6_PREFER_TEMPADDR:
1690 				if (optlen != sizeof(optval)) {
1691 					error = EINVAL;
1692 					break;
1693 				}
1694 				error = sooptcopyin(sopt, &optval,
1695 					sizeof optval, sizeof optval);
1696 				if (error)
1697 					break;
1698 				{
1699 					struct ip6_pktopts **optp;
1700 					optp = &in6p->in6p_outputopts;
1701 					error = ip6_pcbopt(optname,
1702 					    (u_char *)&optval, sizeof(optval),
1703 					    optp, (td != NULL) ? td->td_ucred :
1704 					    NULL, uproto);
1705 					break;
1706 				}
1707 
1708 			case IPV6_2292PKTINFO:
1709 			case IPV6_2292HOPLIMIT:
1710 			case IPV6_2292HOPOPTS:
1711 			case IPV6_2292DSTOPTS:
1712 			case IPV6_2292RTHDR:
1713 				/* RFC 2292 */
1714 				if (optlen != sizeof(int)) {
1715 					error = EINVAL;
1716 					break;
1717 				}
1718 				error = sooptcopyin(sopt, &optval,
1719 					sizeof optval, sizeof optval);
1720 				if (error)
1721 					break;
1722 				switch (optname) {
1723 				case IPV6_2292PKTINFO:
1724 					OPTSET2292(IN6P_PKTINFO);
1725 					break;
1726 				case IPV6_2292HOPLIMIT:
1727 					OPTSET2292(IN6P_HOPLIMIT);
1728 					break;
1729 				case IPV6_2292HOPOPTS:
1730 					/*
1731 					 * Check super-user privilege.
1732 					 * See comments for IPV6_RECVHOPOPTS.
1733 					 */
1734 					if (td != NULL) {
1735 						error = priv_check(td,
1736 						    PRIV_NETINET_SETHDROPTS);
1737 						if (error)
1738 							return (error);
1739 					}
1740 					OPTSET2292(IN6P_HOPOPTS);
1741 					break;
1742 				case IPV6_2292DSTOPTS:
1743 					if (td != NULL) {
1744 						error = priv_check(td,
1745 						    PRIV_NETINET_SETHDROPTS);
1746 						if (error)
1747 							return (error);
1748 					}
1749 					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1750 					break;
1751 				case IPV6_2292RTHDR:
1752 					OPTSET2292(IN6P_RTHDR);
1753 					break;
1754 				}
1755 				break;
1756 			case IPV6_PKTINFO:
1757 			case IPV6_HOPOPTS:
1758 			case IPV6_RTHDR:
1759 			case IPV6_DSTOPTS:
1760 			case IPV6_RTHDRDSTOPTS:
1761 			case IPV6_NEXTHOP:
1762 			{
1763 				/* new advanced API (RFC3542) */
1764 				u_char *optbuf;
1765 				u_char optbuf_storage[MCLBYTES];
1766 				int optlen;
1767 				struct ip6_pktopts **optp;
1768 
1769 				/* cannot mix with RFC2292 */
1770 				if (OPTBIT(IN6P_RFC2292)) {
1771 					error = EINVAL;
1772 					break;
1773 				}
1774 
1775 				/*
1776 				 * We only ensure valsize is not too large
1777 				 * here.  Further validation will be done
1778 				 * later.
1779 				 */
1780 				error = sooptcopyin(sopt, optbuf_storage,
1781 				    sizeof(optbuf_storage), 0);
1782 				if (error)
1783 					break;
1784 				optlen = sopt->sopt_valsize;
1785 				optbuf = optbuf_storage;
1786 				optp = &in6p->in6p_outputopts;
1787 				error = ip6_pcbopt(optname, optbuf, optlen,
1788 				    optp, (td != NULL) ? td->td_ucred : NULL,
1789 				    uproto);
1790 				break;
1791 			}
1792 #undef OPTSET
1793 
1794 			case IPV6_MULTICAST_IF:
1795 			case IPV6_MULTICAST_HOPS:
1796 			case IPV6_MULTICAST_LOOP:
1797 			case IPV6_JOIN_GROUP:
1798 			case IPV6_LEAVE_GROUP:
1799 			case IPV6_MSFILTER:
1800 			case MCAST_BLOCK_SOURCE:
1801 			case MCAST_UNBLOCK_SOURCE:
1802 			case MCAST_JOIN_GROUP:
1803 			case MCAST_LEAVE_GROUP:
1804 			case MCAST_JOIN_SOURCE_GROUP:
1805 			case MCAST_LEAVE_SOURCE_GROUP:
1806 				error = ip6_setmoptions(in6p, sopt);
1807 				break;
1808 
1809 			case IPV6_PORTRANGE:
1810 				error = sooptcopyin(sopt, &optval,
1811 				    sizeof optval, sizeof optval);
1812 				if (error)
1813 					break;
1814 
1815 				INP_WLOCK(in6p);
1816 				switch (optval) {
1817 				case IPV6_PORTRANGE_DEFAULT:
1818 					in6p->inp_flags &= ~(INP_LOWPORT);
1819 					in6p->inp_flags &= ~(INP_HIGHPORT);
1820 					break;
1821 
1822 				case IPV6_PORTRANGE_HIGH:
1823 					in6p->inp_flags &= ~(INP_LOWPORT);
1824 					in6p->inp_flags |= INP_HIGHPORT;
1825 					break;
1826 
1827 				case IPV6_PORTRANGE_LOW:
1828 					in6p->inp_flags &= ~(INP_HIGHPORT);
1829 					in6p->inp_flags |= INP_LOWPORT;
1830 					break;
1831 
1832 				default:
1833 					error = EINVAL;
1834 					break;
1835 				}
1836 				INP_WUNLOCK(in6p);
1837 				break;
1838 
1839 #ifdef IPSEC
1840 			case IPV6_IPSEC_POLICY:
1841 			{
1842 				caddr_t req;
1843 				struct mbuf *m;
1844 
1845 				if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1846 					break;
1847 				if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1848 					break;
1849 				req = mtod(m, caddr_t);
1850 				error = ipsec_set_policy(in6p, optname, req,
1851 				    m->m_len, (sopt->sopt_td != NULL) ?
1852 				    sopt->sopt_td->td_ucred : NULL);
1853 				m_freem(m);
1854 				break;
1855 			}
1856 #endif /* IPSEC */
1857 
1858 			default:
1859 				error = ENOPROTOOPT;
1860 				break;
1861 			}
1862 			break;
1863 
1864 		case SOPT_GET:
1865 			switch (optname) {
1866 
1867 			case IPV6_2292PKTOPTIONS:
1868 #ifdef IPV6_PKTOPTIONS
1869 			case IPV6_PKTOPTIONS:
1870 #endif
1871 				/*
1872 				 * RFC3542 (effectively) deprecated the
1873 				 * semantics of the 2292-style pktoptions.
1874 				 * Since it was not reliable in nature (i.e.,
1875 				 * applications had to expect the lack of some
1876 				 * information after all), it would make sense
1877 				 * to simplify this part by always returning
1878 				 * empty data.
1879 				 */
1880 				sopt->sopt_valsize = 0;
1881 				break;
1882 
1883 			case IPV6_RECVHOPOPTS:
1884 			case IPV6_RECVDSTOPTS:
1885 			case IPV6_RECVRTHDRDSTOPTS:
1886 			case IPV6_UNICAST_HOPS:
1887 			case IPV6_RECVPKTINFO:
1888 			case IPV6_RECVHOPLIMIT:
1889 			case IPV6_RECVRTHDR:
1890 			case IPV6_RECVPATHMTU:
1891 
1892 			case IPV6_V6ONLY:
1893 			case IPV6_PORTRANGE:
1894 			case IPV6_RECVTCLASS:
1895 			case IPV6_AUTOFLOWLABEL:
1896 			case IPV6_BINDANY:
1897 			case IPV6_FLOWID:
1898 			case IPV6_FLOWTYPE:
1899 			case IPV6_RECVFLOWID:
1900 #ifdef	RSS
1901 			case IPV6_RSSBUCKETID:
1902 			case IPV6_RECVRSSBUCKETID:
1903 #endif
1904 			case IPV6_BINDMULTI:
1905 				switch (optname) {
1906 
1907 				case IPV6_RECVHOPOPTS:
1908 					optval = OPTBIT(IN6P_HOPOPTS);
1909 					break;
1910 
1911 				case IPV6_RECVDSTOPTS:
1912 					optval = OPTBIT(IN6P_DSTOPTS);
1913 					break;
1914 
1915 				case IPV6_RECVRTHDRDSTOPTS:
1916 					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1917 					break;
1918 
1919 				case IPV6_UNICAST_HOPS:
1920 					optval = in6p->in6p_hops;
1921 					break;
1922 
1923 				case IPV6_RECVPKTINFO:
1924 					optval = OPTBIT(IN6P_PKTINFO);
1925 					break;
1926 
1927 				case IPV6_RECVHOPLIMIT:
1928 					optval = OPTBIT(IN6P_HOPLIMIT);
1929 					break;
1930 
1931 				case IPV6_RECVRTHDR:
1932 					optval = OPTBIT(IN6P_RTHDR);
1933 					break;
1934 
1935 				case IPV6_RECVPATHMTU:
1936 					optval = OPTBIT(IN6P_MTU);
1937 					break;
1938 
1939 				case IPV6_V6ONLY:
1940 					optval = OPTBIT(IN6P_IPV6_V6ONLY);
1941 					break;
1942 
1943 				case IPV6_PORTRANGE:
1944 				    {
1945 					int flags;
1946 					flags = in6p->inp_flags;
1947 					if (flags & INP_HIGHPORT)
1948 						optval = IPV6_PORTRANGE_HIGH;
1949 					else if (flags & INP_LOWPORT)
1950 						optval = IPV6_PORTRANGE_LOW;
1951 					else
1952 						optval = 0;
1953 					break;
1954 				    }
1955 				case IPV6_RECVTCLASS:
1956 					optval = OPTBIT(IN6P_TCLASS);
1957 					break;
1958 
1959 				case IPV6_AUTOFLOWLABEL:
1960 					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1961 					break;
1962 
1963 				case IPV6_BINDANY:
1964 					optval = OPTBIT(INP_BINDANY);
1965 					break;
1966 
1967 				case IPV6_FLOWID:
1968 					optval = in6p->inp_flowid;
1969 					break;
1970 
1971 				case IPV6_FLOWTYPE:
1972 					optval = in6p->inp_flowtype;
1973 					break;
1974 
1975 				case IPV6_RECVFLOWID:
1976 					optval = OPTBIT2(INP_RECVFLOWID);
1977 					break;
1978 #ifdef	RSS
1979 				case IPV6_RSSBUCKETID:
1980 					retval =
1981 					    rss_hash2bucket(in6p->inp_flowid,
1982 					    in6p->inp_flowtype,
1983 					    &rss_bucket);
1984 					if (retval == 0)
1985 						optval = rss_bucket;
1986 					else
1987 						error = EINVAL;
1988 					break;
1989 
1990 				case IPV6_RECVRSSBUCKETID:
1991 					optval = OPTBIT2(INP_RECVRSSBUCKETID);
1992 					break;
1993 #endif
1994 
1995 				case IPV6_BINDMULTI:
1996 					optval = OPTBIT2(INP_BINDMULTI);
1997 					break;
1998 
1999 				}
2000 				if (error)
2001 					break;
2002 				error = sooptcopyout(sopt, &optval,
2003 					sizeof optval);
2004 				break;
2005 
2006 			case IPV6_PATHMTU:
2007 			{
2008 				u_long pmtu = 0;
2009 				struct ip6_mtuinfo mtuinfo;
2010 
2011 				if (!(so->so_state & SS_ISCONNECTED))
2012 					return (ENOTCONN);
2013 				/*
2014 				 * XXX: we dot not consider the case of source
2015 				 * routing, or optional information to specify
2016 				 * the outgoing interface.
2017 				 */
2018 				error = ip6_getpmtu_ctl(so->so_fibnum,
2019 				    &in6p->in6p_faddr, &pmtu);
2020 				if (error)
2021 					break;
2022 				if (pmtu > IPV6_MAXPACKET)
2023 					pmtu = IPV6_MAXPACKET;
2024 
2025 				bzero(&mtuinfo, sizeof(mtuinfo));
2026 				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2027 				optdata = (void *)&mtuinfo;
2028 				optdatalen = sizeof(mtuinfo);
2029 				error = sooptcopyout(sopt, optdata,
2030 				    optdatalen);
2031 				break;
2032 			}
2033 
2034 			case IPV6_2292PKTINFO:
2035 			case IPV6_2292HOPLIMIT:
2036 			case IPV6_2292HOPOPTS:
2037 			case IPV6_2292RTHDR:
2038 			case IPV6_2292DSTOPTS:
2039 				switch (optname) {
2040 				case IPV6_2292PKTINFO:
2041 					optval = OPTBIT(IN6P_PKTINFO);
2042 					break;
2043 				case IPV6_2292HOPLIMIT:
2044 					optval = OPTBIT(IN6P_HOPLIMIT);
2045 					break;
2046 				case IPV6_2292HOPOPTS:
2047 					optval = OPTBIT(IN6P_HOPOPTS);
2048 					break;
2049 				case IPV6_2292RTHDR:
2050 					optval = OPTBIT(IN6P_RTHDR);
2051 					break;
2052 				case IPV6_2292DSTOPTS:
2053 					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2054 					break;
2055 				}
2056 				error = sooptcopyout(sopt, &optval,
2057 				    sizeof optval);
2058 				break;
2059 			case IPV6_PKTINFO:
2060 			case IPV6_HOPOPTS:
2061 			case IPV6_RTHDR:
2062 			case IPV6_DSTOPTS:
2063 			case IPV6_RTHDRDSTOPTS:
2064 			case IPV6_NEXTHOP:
2065 			case IPV6_TCLASS:
2066 			case IPV6_DONTFRAG:
2067 			case IPV6_USE_MIN_MTU:
2068 			case IPV6_PREFER_TEMPADDR:
2069 				error = ip6_getpcbopt(in6p->in6p_outputopts,
2070 				    optname, sopt);
2071 				break;
2072 
2073 			case IPV6_MULTICAST_IF:
2074 			case IPV6_MULTICAST_HOPS:
2075 			case IPV6_MULTICAST_LOOP:
2076 			case IPV6_MSFILTER:
2077 				error = ip6_getmoptions(in6p, sopt);
2078 				break;
2079 
2080 #ifdef IPSEC
2081 			case IPV6_IPSEC_POLICY:
2082 			  {
2083 				caddr_t req = NULL;
2084 				size_t len = 0;
2085 				struct mbuf *m = NULL;
2086 				struct mbuf **mp = &m;
2087 				size_t ovalsize = sopt->sopt_valsize;
2088 				caddr_t oval = (caddr_t)sopt->sopt_val;
2089 
2090 				error = soopt_getm(sopt, &m); /* XXX */
2091 				if (error != 0)
2092 					break;
2093 				error = soopt_mcopyin(sopt, m); /* XXX */
2094 				if (error != 0)
2095 					break;
2096 				sopt->sopt_valsize = ovalsize;
2097 				sopt->sopt_val = oval;
2098 				if (m) {
2099 					req = mtod(m, caddr_t);
2100 					len = m->m_len;
2101 				}
2102 				error = ipsec_get_policy(in6p, req, len, mp);
2103 				if (error == 0)
2104 					error = soopt_mcopyout(sopt, m); /* XXX */
2105 				if (error == 0 && m)
2106 					m_freem(m);
2107 				break;
2108 			  }
2109 #endif /* IPSEC */
2110 
2111 			default:
2112 				error = ENOPROTOOPT;
2113 				break;
2114 			}
2115 			break;
2116 		}
2117 	}
2118 	return (error);
2119 }
2120 
2121 int
ip6_raw_ctloutput(struct socket * so,struct sockopt * sopt)2122 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2123 {
2124 	int error = 0, optval, optlen;
2125 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2126 	struct inpcb *in6p = sotoinpcb(so);
2127 	int level, op, optname;
2128 
2129 	level = sopt->sopt_level;
2130 	op = sopt->sopt_dir;
2131 	optname = sopt->sopt_name;
2132 	optlen = sopt->sopt_valsize;
2133 
2134 	if (level != IPPROTO_IPV6) {
2135 		return (EINVAL);
2136 	}
2137 
2138 	switch (optname) {
2139 	case IPV6_CHECKSUM:
2140 		/*
2141 		 * For ICMPv6 sockets, no modification allowed for checksum
2142 		 * offset, permit "no change" values to help existing apps.
2143 		 *
2144 		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2145 		 * for an ICMPv6 socket will fail."
2146 		 * The current behavior does not meet RFC3542.
2147 		 */
2148 		switch (op) {
2149 		case SOPT_SET:
2150 			if (optlen != sizeof(int)) {
2151 				error = EINVAL;
2152 				break;
2153 			}
2154 			error = sooptcopyin(sopt, &optval, sizeof(optval),
2155 					    sizeof(optval));
2156 			if (error)
2157 				break;
2158 			if ((optval % 2) != 0) {
2159 				/* the API assumes even offset values */
2160 				error = EINVAL;
2161 			} else if (so->so_proto->pr_protocol ==
2162 			    IPPROTO_ICMPV6) {
2163 				if (optval != icmp6off)
2164 					error = EINVAL;
2165 			} else
2166 				in6p->in6p_cksum = optval;
2167 			break;
2168 
2169 		case SOPT_GET:
2170 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2171 				optval = icmp6off;
2172 			else
2173 				optval = in6p->in6p_cksum;
2174 
2175 			error = sooptcopyout(sopt, &optval, sizeof(optval));
2176 			break;
2177 
2178 		default:
2179 			error = EINVAL;
2180 			break;
2181 		}
2182 		break;
2183 
2184 	default:
2185 		error = ENOPROTOOPT;
2186 		break;
2187 	}
2188 
2189 	return (error);
2190 }
2191 
2192 /*
2193  * Set up IP6 options in pcb for insertion in output packets or
2194  * specifying behavior of outgoing packets.
2195  */
2196 static int
ip6_pcbopts(struct ip6_pktopts ** pktopt,struct mbuf * m,struct socket * so,struct sockopt * sopt)2197 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2198     struct socket *so, struct sockopt *sopt)
2199 {
2200 	struct ip6_pktopts *opt = *pktopt;
2201 	int error = 0;
2202 	struct thread *td = sopt->sopt_td;
2203 
2204 	/* turn off any old options. */
2205 	if (opt) {
2206 #ifdef DIAGNOSTIC
2207 		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2208 		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2209 		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2210 			printf("ip6_pcbopts: all specified options are cleared.\n");
2211 #endif
2212 		ip6_clearpktopts(opt, -1);
2213 	} else
2214 		opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2215 	*pktopt = NULL;
2216 
2217 	if (!m || m->m_len == 0) {
2218 		/*
2219 		 * Only turning off any previous options, regardless of
2220 		 * whether the opt is just created or given.
2221 		 */
2222 		free(opt, M_IP6OPT);
2223 		return (0);
2224 	}
2225 
2226 	/*  set options specified by user. */
2227 	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2228 	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2229 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2230 		free(opt, M_IP6OPT);
2231 		return (error);
2232 	}
2233 	*pktopt = opt;
2234 	return (0);
2235 }
2236 
2237 /*
2238  * initialize ip6_pktopts.  beware that there are non-zero default values in
2239  * the struct.
2240  */
2241 void
ip6_initpktopts(struct ip6_pktopts * opt)2242 ip6_initpktopts(struct ip6_pktopts *opt)
2243 {
2244 
2245 	bzero(opt, sizeof(*opt));
2246 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2247 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2248 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2249 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2250 }
2251 
2252 static int
ip6_pcbopt(int optname,u_char * buf,int len,struct ip6_pktopts ** pktopt,struct ucred * cred,int uproto)2253 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2254     struct ucred *cred, int uproto)
2255 {
2256 	struct ip6_pktopts *opt;
2257 
2258 	if (*pktopt == NULL) {
2259 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2260 		    M_WAITOK);
2261 		ip6_initpktopts(*pktopt);
2262 	}
2263 	opt = *pktopt;
2264 
2265 	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2266 }
2267 
2268 static int
ip6_getpcbopt(struct ip6_pktopts * pktopt,int optname,struct sockopt * sopt)2269 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2270 {
2271 	void *optdata = NULL;
2272 	int optdatalen = 0;
2273 	struct ip6_ext *ip6e;
2274 	int error = 0;
2275 	struct in6_pktinfo null_pktinfo;
2276 	int deftclass = 0, on;
2277 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2278 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2279 
2280 	switch (optname) {
2281 	case IPV6_PKTINFO:
2282 		optdata = (void *)&null_pktinfo;
2283 		if (pktopt && pktopt->ip6po_pktinfo) {
2284 			bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2285 			    sizeof(null_pktinfo));
2286 			in6_clearscope(&null_pktinfo.ipi6_addr);
2287 		} else {
2288 			/* XXX: we don't have to do this every time... */
2289 			bzero(&null_pktinfo, sizeof(null_pktinfo));
2290 		}
2291 		optdatalen = sizeof(struct in6_pktinfo);
2292 		break;
2293 	case IPV6_TCLASS:
2294 		if (pktopt && pktopt->ip6po_tclass >= 0)
2295 			optdata = (void *)&pktopt->ip6po_tclass;
2296 		else
2297 			optdata = (void *)&deftclass;
2298 		optdatalen = sizeof(int);
2299 		break;
2300 	case IPV6_HOPOPTS:
2301 		if (pktopt && pktopt->ip6po_hbh) {
2302 			optdata = (void *)pktopt->ip6po_hbh;
2303 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2304 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2305 		}
2306 		break;
2307 	case IPV6_RTHDR:
2308 		if (pktopt && pktopt->ip6po_rthdr) {
2309 			optdata = (void *)pktopt->ip6po_rthdr;
2310 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2311 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2312 		}
2313 		break;
2314 	case IPV6_RTHDRDSTOPTS:
2315 		if (pktopt && pktopt->ip6po_dest1) {
2316 			optdata = (void *)pktopt->ip6po_dest1;
2317 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2318 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2319 		}
2320 		break;
2321 	case IPV6_DSTOPTS:
2322 		if (pktopt && pktopt->ip6po_dest2) {
2323 			optdata = (void *)pktopt->ip6po_dest2;
2324 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2325 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2326 		}
2327 		break;
2328 	case IPV6_NEXTHOP:
2329 		if (pktopt && pktopt->ip6po_nexthop) {
2330 			optdata = (void *)pktopt->ip6po_nexthop;
2331 			optdatalen = pktopt->ip6po_nexthop->sa_len;
2332 		}
2333 		break;
2334 	case IPV6_USE_MIN_MTU:
2335 		if (pktopt)
2336 			optdata = (void *)&pktopt->ip6po_minmtu;
2337 		else
2338 			optdata = (void *)&defminmtu;
2339 		optdatalen = sizeof(int);
2340 		break;
2341 	case IPV6_DONTFRAG:
2342 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2343 			on = 1;
2344 		else
2345 			on = 0;
2346 		optdata = (void *)&on;
2347 		optdatalen = sizeof(on);
2348 		break;
2349 	case IPV6_PREFER_TEMPADDR:
2350 		if (pktopt)
2351 			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2352 		else
2353 			optdata = (void *)&defpreftemp;
2354 		optdatalen = sizeof(int);
2355 		break;
2356 	default:		/* should not happen */
2357 #ifdef DIAGNOSTIC
2358 		panic("ip6_getpcbopt: unexpected option\n");
2359 #endif
2360 		return (ENOPROTOOPT);
2361 	}
2362 
2363 	error = sooptcopyout(sopt, optdata, optdatalen);
2364 
2365 	return (error);
2366 }
2367 
2368 void
ip6_clearpktopts(struct ip6_pktopts * pktopt,int optname)2369 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2370 {
2371 	if (pktopt == NULL)
2372 		return;
2373 
2374 	if (optname == -1 || optname == IPV6_PKTINFO) {
2375 		if (pktopt->ip6po_pktinfo)
2376 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
2377 		pktopt->ip6po_pktinfo = NULL;
2378 	}
2379 	if (optname == -1 || optname == IPV6_HOPLIMIT)
2380 		pktopt->ip6po_hlim = -1;
2381 	if (optname == -1 || optname == IPV6_TCLASS)
2382 		pktopt->ip6po_tclass = -1;
2383 	if (optname == -1 || optname == IPV6_NEXTHOP) {
2384 		if (pktopt->ip6po_nextroute.ro_rt) {
2385 			RTFREE(pktopt->ip6po_nextroute.ro_rt);
2386 			pktopt->ip6po_nextroute.ro_rt = NULL;
2387 		}
2388 		if (pktopt->ip6po_nexthop)
2389 			free(pktopt->ip6po_nexthop, M_IP6OPT);
2390 		pktopt->ip6po_nexthop = NULL;
2391 	}
2392 	if (optname == -1 || optname == IPV6_HOPOPTS) {
2393 		if (pktopt->ip6po_hbh)
2394 			free(pktopt->ip6po_hbh, M_IP6OPT);
2395 		pktopt->ip6po_hbh = NULL;
2396 	}
2397 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2398 		if (pktopt->ip6po_dest1)
2399 			free(pktopt->ip6po_dest1, M_IP6OPT);
2400 		pktopt->ip6po_dest1 = NULL;
2401 	}
2402 	if (optname == -1 || optname == IPV6_RTHDR) {
2403 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2404 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2405 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2406 		if (pktopt->ip6po_route.ro_rt) {
2407 			RTFREE(pktopt->ip6po_route.ro_rt);
2408 			pktopt->ip6po_route.ro_rt = NULL;
2409 		}
2410 	}
2411 	if (optname == -1 || optname == IPV6_DSTOPTS) {
2412 		if (pktopt->ip6po_dest2)
2413 			free(pktopt->ip6po_dest2, M_IP6OPT);
2414 		pktopt->ip6po_dest2 = NULL;
2415 	}
2416 }
2417 
2418 #define PKTOPT_EXTHDRCPY(type) \
2419 do {\
2420 	if (src->type) {\
2421 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2422 		dst->type = malloc(hlen, M_IP6OPT, canwait);\
2423 		if (dst->type == NULL && canwait == M_NOWAIT)\
2424 			goto bad;\
2425 		bcopy(src->type, dst->type, hlen);\
2426 	}\
2427 } while (/*CONSTCOND*/ 0)
2428 
2429 static int
copypktopts(struct ip6_pktopts * dst,struct ip6_pktopts * src,int canwait)2430 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2431 {
2432 	if (dst == NULL || src == NULL)  {
2433 		printf("ip6_clearpktopts: invalid argument\n");
2434 		return (EINVAL);
2435 	}
2436 
2437 	dst->ip6po_hlim = src->ip6po_hlim;
2438 	dst->ip6po_tclass = src->ip6po_tclass;
2439 	dst->ip6po_flags = src->ip6po_flags;
2440 	dst->ip6po_minmtu = src->ip6po_minmtu;
2441 	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2442 	if (src->ip6po_pktinfo) {
2443 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2444 		    M_IP6OPT, canwait);
2445 		if (dst->ip6po_pktinfo == NULL)
2446 			goto bad;
2447 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2448 	}
2449 	if (src->ip6po_nexthop) {
2450 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2451 		    M_IP6OPT, canwait);
2452 		if (dst->ip6po_nexthop == NULL)
2453 			goto bad;
2454 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2455 		    src->ip6po_nexthop->sa_len);
2456 	}
2457 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2458 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2459 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2460 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2461 	return (0);
2462 
2463   bad:
2464 	ip6_clearpktopts(dst, -1);
2465 	return (ENOBUFS);
2466 }
2467 #undef PKTOPT_EXTHDRCPY
2468 
2469 struct ip6_pktopts *
ip6_copypktopts(struct ip6_pktopts * src,int canwait)2470 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2471 {
2472 	int error;
2473 	struct ip6_pktopts *dst;
2474 
2475 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2476 	if (dst == NULL)
2477 		return (NULL);
2478 	ip6_initpktopts(dst);
2479 
2480 	if ((error = copypktopts(dst, src, canwait)) != 0) {
2481 		free(dst, M_IP6OPT);
2482 		return (NULL);
2483 	}
2484 
2485 	return (dst);
2486 }
2487 
2488 void
ip6_freepcbopts(struct ip6_pktopts * pktopt)2489 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2490 {
2491 	if (pktopt == NULL)
2492 		return;
2493 
2494 	ip6_clearpktopts(pktopt, -1);
2495 
2496 	free(pktopt, M_IP6OPT);
2497 }
2498 
2499 /*
2500  * Set IPv6 outgoing packet options based on advanced API.
2501  */
2502 int
ip6_setpktopts(struct mbuf * control,struct ip6_pktopts * opt,struct ip6_pktopts * stickyopt,struct ucred * cred,int uproto)2503 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2504     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2505 {
2506 	struct cmsghdr *cm = 0;
2507 
2508 	if (control == NULL || opt == NULL)
2509 		return (EINVAL);
2510 
2511 	ip6_initpktopts(opt);
2512 	if (stickyopt) {
2513 		int error;
2514 
2515 		/*
2516 		 * If stickyopt is provided, make a local copy of the options
2517 		 * for this particular packet, then override them by ancillary
2518 		 * objects.
2519 		 * XXX: copypktopts() does not copy the cached route to a next
2520 		 * hop (if any).  This is not very good in terms of efficiency,
2521 		 * but we can allow this since this option should be rarely
2522 		 * used.
2523 		 */
2524 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2525 			return (error);
2526 	}
2527 
2528 	/*
2529 	 * XXX: Currently, we assume all the optional information is stored
2530 	 * in a single mbuf.
2531 	 */
2532 	if (control->m_next)
2533 		return (EINVAL);
2534 
2535 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2536 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2537 		int error;
2538 
2539 		if (control->m_len < CMSG_LEN(0))
2540 			return (EINVAL);
2541 
2542 		cm = mtod(control, struct cmsghdr *);
2543 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2544 			return (EINVAL);
2545 		if (cm->cmsg_level != IPPROTO_IPV6)
2546 			continue;
2547 
2548 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2549 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2550 		if (error)
2551 			return (error);
2552 	}
2553 
2554 	return (0);
2555 }
2556 
2557 /*
2558  * Set a particular packet option, as a sticky option or an ancillary data
2559  * item.  "len" can be 0 only when it's a sticky option.
2560  * We have 4 cases of combination of "sticky" and "cmsg":
2561  * "sticky=0, cmsg=0": impossible
2562  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2563  * "sticky=1, cmsg=0": RFC3542 socket option
2564  * "sticky=1, cmsg=1": RFC2292 socket option
2565  */
2566 static int
ip6_setpktopt(int optname,u_char * buf,int len,struct ip6_pktopts * opt,struct ucred * cred,int sticky,int cmsg,int uproto)2567 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2568     struct ucred *cred, int sticky, int cmsg, int uproto)
2569 {
2570 	int minmtupolicy, preftemp;
2571 	int error;
2572 
2573 	if (!sticky && !cmsg) {
2574 #ifdef DIAGNOSTIC
2575 		printf("ip6_setpktopt: impossible case\n");
2576 #endif
2577 		return (EINVAL);
2578 	}
2579 
2580 	/*
2581 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2582 	 * not be specified in the context of RFC3542.  Conversely,
2583 	 * RFC3542 types should not be specified in the context of RFC2292.
2584 	 */
2585 	if (!cmsg) {
2586 		switch (optname) {
2587 		case IPV6_2292PKTINFO:
2588 		case IPV6_2292HOPLIMIT:
2589 		case IPV6_2292NEXTHOP:
2590 		case IPV6_2292HOPOPTS:
2591 		case IPV6_2292DSTOPTS:
2592 		case IPV6_2292RTHDR:
2593 		case IPV6_2292PKTOPTIONS:
2594 			return (ENOPROTOOPT);
2595 		}
2596 	}
2597 	if (sticky && cmsg) {
2598 		switch (optname) {
2599 		case IPV6_PKTINFO:
2600 		case IPV6_HOPLIMIT:
2601 		case IPV6_NEXTHOP:
2602 		case IPV6_HOPOPTS:
2603 		case IPV6_DSTOPTS:
2604 		case IPV6_RTHDRDSTOPTS:
2605 		case IPV6_RTHDR:
2606 		case IPV6_USE_MIN_MTU:
2607 		case IPV6_DONTFRAG:
2608 		case IPV6_TCLASS:
2609 		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2610 			return (ENOPROTOOPT);
2611 		}
2612 	}
2613 
2614 	switch (optname) {
2615 	case IPV6_2292PKTINFO:
2616 	case IPV6_PKTINFO:
2617 	{
2618 		struct ifnet *ifp = NULL;
2619 		struct in6_pktinfo *pktinfo;
2620 
2621 		if (len != sizeof(struct in6_pktinfo))
2622 			return (EINVAL);
2623 
2624 		pktinfo = (struct in6_pktinfo *)buf;
2625 
2626 		/*
2627 		 * An application can clear any sticky IPV6_PKTINFO option by
2628 		 * doing a "regular" setsockopt with ipi6_addr being
2629 		 * in6addr_any and ipi6_ifindex being zero.
2630 		 * [RFC 3542, Section 6]
2631 		 */
2632 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2633 		    pktinfo->ipi6_ifindex == 0 &&
2634 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2635 			ip6_clearpktopts(opt, optname);
2636 			break;
2637 		}
2638 
2639 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2640 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2641 			return (EINVAL);
2642 		}
2643 		if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2644 			return (EINVAL);
2645 		/* validate the interface index if specified. */
2646 		if (pktinfo->ipi6_ifindex > V_if_index)
2647 			 return (ENXIO);
2648 		if (pktinfo->ipi6_ifindex) {
2649 			ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2650 			if (ifp == NULL)
2651 				return (ENXIO);
2652 		}
2653 		if (ifp != NULL && (
2654 		    ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED))
2655 			return (ENETDOWN);
2656 
2657 		if (ifp != NULL &&
2658 		    !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2659 			struct in6_ifaddr *ia;
2660 
2661 			in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2662 			ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2663 			if (ia == NULL)
2664 				return (EADDRNOTAVAIL);
2665 			ifa_free(&ia->ia_ifa);
2666 		}
2667 		/*
2668 		 * We store the address anyway, and let in6_selectsrc()
2669 		 * validate the specified address.  This is because ipi6_addr
2670 		 * may not have enough information about its scope zone, and
2671 		 * we may need additional information (such as outgoing
2672 		 * interface or the scope zone of a destination address) to
2673 		 * disambiguate the scope.
2674 		 * XXX: the delay of the validation may confuse the
2675 		 * application when it is used as a sticky option.
2676 		 */
2677 		if (opt->ip6po_pktinfo == NULL) {
2678 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2679 			    M_IP6OPT, M_NOWAIT);
2680 			if (opt->ip6po_pktinfo == NULL)
2681 				return (ENOBUFS);
2682 		}
2683 		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2684 		break;
2685 	}
2686 
2687 	case IPV6_2292HOPLIMIT:
2688 	case IPV6_HOPLIMIT:
2689 	{
2690 		int *hlimp;
2691 
2692 		/*
2693 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2694 		 * to simplify the ordering among hoplimit options.
2695 		 */
2696 		if (optname == IPV6_HOPLIMIT && sticky)
2697 			return (ENOPROTOOPT);
2698 
2699 		if (len != sizeof(int))
2700 			return (EINVAL);
2701 		hlimp = (int *)buf;
2702 		if (*hlimp < -1 || *hlimp > 255)
2703 			return (EINVAL);
2704 
2705 		opt->ip6po_hlim = *hlimp;
2706 		break;
2707 	}
2708 
2709 	case IPV6_TCLASS:
2710 	{
2711 		int tclass;
2712 
2713 		if (len != sizeof(int))
2714 			return (EINVAL);
2715 		tclass = *(int *)buf;
2716 		if (tclass < -1 || tclass > 255)
2717 			return (EINVAL);
2718 
2719 		opt->ip6po_tclass = tclass;
2720 		break;
2721 	}
2722 
2723 	case IPV6_2292NEXTHOP:
2724 	case IPV6_NEXTHOP:
2725 		if (cred != NULL) {
2726 			error = priv_check_cred(cred,
2727 			    PRIV_NETINET_SETHDROPTS, 0);
2728 			if (error)
2729 				return (error);
2730 		}
2731 
2732 		if (len == 0) {	/* just remove the option */
2733 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
2734 			break;
2735 		}
2736 
2737 		/* check if cmsg_len is large enough for sa_len */
2738 		if (len < sizeof(struct sockaddr) || len < *buf)
2739 			return (EINVAL);
2740 
2741 		switch (((struct sockaddr *)buf)->sa_family) {
2742 		case AF_INET6:
2743 		{
2744 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2745 			int error;
2746 
2747 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2748 				return (EINVAL);
2749 
2750 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2751 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2752 				return (EINVAL);
2753 			}
2754 			if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2755 			    != 0) {
2756 				return (error);
2757 			}
2758 			break;
2759 		}
2760 		case AF_LINK:	/* should eventually be supported */
2761 		default:
2762 			return (EAFNOSUPPORT);
2763 		}
2764 
2765 		/* turn off the previous option, then set the new option. */
2766 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
2767 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2768 		if (opt->ip6po_nexthop == NULL)
2769 			return (ENOBUFS);
2770 		bcopy(buf, opt->ip6po_nexthop, *buf);
2771 		break;
2772 
2773 	case IPV6_2292HOPOPTS:
2774 	case IPV6_HOPOPTS:
2775 	{
2776 		struct ip6_hbh *hbh;
2777 		int hbhlen;
2778 
2779 		/*
2780 		 * XXX: We don't allow a non-privileged user to set ANY HbH
2781 		 * options, since per-option restriction has too much
2782 		 * overhead.
2783 		 */
2784 		if (cred != NULL) {
2785 			error = priv_check_cred(cred,
2786 			    PRIV_NETINET_SETHDROPTS, 0);
2787 			if (error)
2788 				return (error);
2789 		}
2790 
2791 		if (len == 0) {
2792 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
2793 			break;	/* just remove the option */
2794 		}
2795 
2796 		/* message length validation */
2797 		if (len < sizeof(struct ip6_hbh))
2798 			return (EINVAL);
2799 		hbh = (struct ip6_hbh *)buf;
2800 		hbhlen = (hbh->ip6h_len + 1) << 3;
2801 		if (len != hbhlen)
2802 			return (EINVAL);
2803 
2804 		/* turn off the previous option, then set the new option. */
2805 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
2806 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2807 		if (opt->ip6po_hbh == NULL)
2808 			return (ENOBUFS);
2809 		bcopy(hbh, opt->ip6po_hbh, hbhlen);
2810 
2811 		break;
2812 	}
2813 
2814 	case IPV6_2292DSTOPTS:
2815 	case IPV6_DSTOPTS:
2816 	case IPV6_RTHDRDSTOPTS:
2817 	{
2818 		struct ip6_dest *dest, **newdest = NULL;
2819 		int destlen;
2820 
2821 		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2822 			error = priv_check_cred(cred,
2823 			    PRIV_NETINET_SETHDROPTS, 0);
2824 			if (error)
2825 				return (error);
2826 		}
2827 
2828 		if (len == 0) {
2829 			ip6_clearpktopts(opt, optname);
2830 			break;	/* just remove the option */
2831 		}
2832 
2833 		/* message length validation */
2834 		if (len < sizeof(struct ip6_dest))
2835 			return (EINVAL);
2836 		dest = (struct ip6_dest *)buf;
2837 		destlen = (dest->ip6d_len + 1) << 3;
2838 		if (len != destlen)
2839 			return (EINVAL);
2840 
2841 		/*
2842 		 * Determine the position that the destination options header
2843 		 * should be inserted; before or after the routing header.
2844 		 */
2845 		switch (optname) {
2846 		case IPV6_2292DSTOPTS:
2847 			/*
2848 			 * The old advacned API is ambiguous on this point.
2849 			 * Our approach is to determine the position based
2850 			 * according to the existence of a routing header.
2851 			 * Note, however, that this depends on the order of the
2852 			 * extension headers in the ancillary data; the 1st
2853 			 * part of the destination options header must appear
2854 			 * before the routing header in the ancillary data,
2855 			 * too.
2856 			 * RFC3542 solved the ambiguity by introducing
2857 			 * separate ancillary data or option types.
2858 			 */
2859 			if (opt->ip6po_rthdr == NULL)
2860 				newdest = &opt->ip6po_dest1;
2861 			else
2862 				newdest = &opt->ip6po_dest2;
2863 			break;
2864 		case IPV6_RTHDRDSTOPTS:
2865 			newdest = &opt->ip6po_dest1;
2866 			break;
2867 		case IPV6_DSTOPTS:
2868 			newdest = &opt->ip6po_dest2;
2869 			break;
2870 		}
2871 
2872 		/* turn off the previous option, then set the new option. */
2873 		ip6_clearpktopts(opt, optname);
2874 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2875 		if (*newdest == NULL)
2876 			return (ENOBUFS);
2877 		bcopy(dest, *newdest, destlen);
2878 
2879 		break;
2880 	}
2881 
2882 	case IPV6_2292RTHDR:
2883 	case IPV6_RTHDR:
2884 	{
2885 		struct ip6_rthdr *rth;
2886 		int rthlen;
2887 
2888 		if (len == 0) {
2889 			ip6_clearpktopts(opt, IPV6_RTHDR);
2890 			break;	/* just remove the option */
2891 		}
2892 
2893 		/* message length validation */
2894 		if (len < sizeof(struct ip6_rthdr))
2895 			return (EINVAL);
2896 		rth = (struct ip6_rthdr *)buf;
2897 		rthlen = (rth->ip6r_len + 1) << 3;
2898 		if (len != rthlen)
2899 			return (EINVAL);
2900 
2901 		switch (rth->ip6r_type) {
2902 		case IPV6_RTHDR_TYPE_0:
2903 			if (rth->ip6r_len == 0)	/* must contain one addr */
2904 				return (EINVAL);
2905 			if (rth->ip6r_len % 2) /* length must be even */
2906 				return (EINVAL);
2907 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2908 				return (EINVAL);
2909 			break;
2910 		default:
2911 			return (EINVAL);	/* not supported */
2912 		}
2913 
2914 		/* turn off the previous option */
2915 		ip6_clearpktopts(opt, IPV6_RTHDR);
2916 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2917 		if (opt->ip6po_rthdr == NULL)
2918 			return (ENOBUFS);
2919 		bcopy(rth, opt->ip6po_rthdr, rthlen);
2920 
2921 		break;
2922 	}
2923 
2924 	case IPV6_USE_MIN_MTU:
2925 		if (len != sizeof(int))
2926 			return (EINVAL);
2927 		minmtupolicy = *(int *)buf;
2928 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2929 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
2930 		    minmtupolicy != IP6PO_MINMTU_ALL) {
2931 			return (EINVAL);
2932 		}
2933 		opt->ip6po_minmtu = minmtupolicy;
2934 		break;
2935 
2936 	case IPV6_DONTFRAG:
2937 		if (len != sizeof(int))
2938 			return (EINVAL);
2939 
2940 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2941 			/*
2942 			 * we ignore this option for TCP sockets.
2943 			 * (RFC3542 leaves this case unspecified.)
2944 			 */
2945 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2946 		} else
2947 			opt->ip6po_flags |= IP6PO_DONTFRAG;
2948 		break;
2949 
2950 	case IPV6_PREFER_TEMPADDR:
2951 		if (len != sizeof(int))
2952 			return (EINVAL);
2953 		preftemp = *(int *)buf;
2954 		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2955 		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2956 		    preftemp != IP6PO_TEMPADDR_PREFER) {
2957 			return (EINVAL);
2958 		}
2959 		opt->ip6po_prefer_tempaddr = preftemp;
2960 		break;
2961 
2962 	default:
2963 		return (ENOPROTOOPT);
2964 	} /* end of switch */
2965 
2966 	return (0);
2967 }
2968 
2969 /*
2970  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2971  * packet to the input queue of a specified interface.  Note that this
2972  * calls the output routine of the loopback "driver", but with an interface
2973  * pointer that might NOT be &loif -- easier than replicating that code here.
2974  */
2975 void
ip6_mloopback(struct ifnet * ifp,const struct mbuf * m)2976 ip6_mloopback(struct ifnet *ifp, const struct mbuf *m)
2977 {
2978 	struct mbuf *copym;
2979 	struct ip6_hdr *ip6;
2980 
2981 	copym = m_copy(m, 0, M_COPYALL);
2982 	if (copym == NULL)
2983 		return;
2984 
2985 	/*
2986 	 * Make sure to deep-copy IPv6 header portion in case the data
2987 	 * is in an mbuf cluster, so that we can safely override the IPv6
2988 	 * header portion later.
2989 	 */
2990 	if (!M_WRITABLE(copym) ||
2991 	    copym->m_len < sizeof(struct ip6_hdr)) {
2992 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
2993 		if (copym == NULL)
2994 			return;
2995 	}
2996 	ip6 = mtod(copym, struct ip6_hdr *);
2997 	/*
2998 	 * clear embedded scope identifiers if necessary.
2999 	 * in6_clearscope will touch the addresses only when necessary.
3000 	 */
3001 	in6_clearscope(&ip6->ip6_src);
3002 	in6_clearscope(&ip6->ip6_dst);
3003 	if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3004 		copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3005 		    CSUM_PSEUDO_HDR;
3006 		copym->m_pkthdr.csum_data = 0xffff;
3007 	}
3008 	if_simloop(ifp, copym, AF_INET6, 0);
3009 }
3010 
3011 /*
3012  * Chop IPv6 header off from the payload.
3013  */
3014 static int
ip6_splithdr(struct mbuf * m,struct ip6_exthdrs * exthdrs)3015 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3016 {
3017 	struct mbuf *mh;
3018 	struct ip6_hdr *ip6;
3019 
3020 	ip6 = mtod(m, struct ip6_hdr *);
3021 	if (m->m_len > sizeof(*ip6)) {
3022 		mh = m_gethdr(M_NOWAIT, MT_DATA);
3023 		if (mh == NULL) {
3024 			m_freem(m);
3025 			return ENOBUFS;
3026 		}
3027 		m_move_pkthdr(mh, m);
3028 		M_ALIGN(mh, sizeof(*ip6));
3029 		m->m_len -= sizeof(*ip6);
3030 		m->m_data += sizeof(*ip6);
3031 		mh->m_next = m;
3032 		m = mh;
3033 		m->m_len = sizeof(*ip6);
3034 		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3035 	}
3036 	exthdrs->ip6e_ip6 = m;
3037 	return 0;
3038 }
3039 
3040 /*
3041  * Compute IPv6 extension header length.
3042  */
3043 int
ip6_optlen(struct inpcb * in6p)3044 ip6_optlen(struct inpcb *in6p)
3045 {
3046 	int len;
3047 
3048 	if (!in6p->in6p_outputopts)
3049 		return 0;
3050 
3051 	len = 0;
3052 #define elen(x) \
3053     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3054 
3055 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
3056 	if (in6p->in6p_outputopts->ip6po_rthdr)
3057 		/* dest1 is valid with rthdr only */
3058 		len += elen(in6p->in6p_outputopts->ip6po_dest1);
3059 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3060 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
3061 	return len;
3062 #undef elen
3063 }
3064