xref: /freebsd-14-stable/sys/netinet6/ip6_output.c (revision a55bde2328e53b718faa68d00479b9652dbe44ad)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	$KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
32  */
33 
34 /*-
35  * Copyright (c) 1982, 1986, 1988, 1990, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  *
62  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
63  */
64 
65 #include <sys/cdefs.h>
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_ipsec.h"
69 #include "opt_kern_tls.h"
70 #include "opt_ratelimit.h"
71 #include "opt_route.h"
72 #include "opt_rss.h"
73 #include "opt_sctp.h"
74 
75 #include <sys/param.h>
76 #include <sys/kernel.h>
77 #include <sys/ktls.h>
78 #include <sys/malloc.h>
79 #include <sys/mbuf.h>
80 #include <sys/errno.h>
81 #include <sys/priv.h>
82 #include <sys/proc.h>
83 #include <sys/protosw.h>
84 #include <sys/socket.h>
85 #include <sys/socketvar.h>
86 #include <sys/syslog.h>
87 #include <sys/ucred.h>
88 
89 #include <machine/in_cksum.h>
90 
91 #include <net/if.h>
92 #include <net/if_var.h>
93 #include <net/if_private.h>
94 #include <net/if_vlan_var.h>
95 #include <net/if_llatbl.h>
96 #include <net/ethernet.h>
97 #include <net/netisr.h>
98 #include <net/route.h>
99 #include <net/route/nhop.h>
100 #include <net/pfil.h>
101 #include <net/rss_config.h>
102 #include <net/vnet.h>
103 
104 #include <netinet/in.h>
105 #include <netinet/in_var.h>
106 #include <netinet/ip_var.h>
107 #include <netinet6/in6_fib.h>
108 #include <netinet6/in6_var.h>
109 #include <netinet/ip6.h>
110 #include <netinet/icmp6.h>
111 #include <netinet6/ip6_var.h>
112 #include <netinet/in_pcb.h>
113 #include <netinet/tcp_var.h>
114 #include <netinet6/nd6.h>
115 #include <netinet6/in6_rss.h>
116 
117 #include <netipsec/ipsec_support.h>
118 #if defined(SCTP) || defined(SCTP_SUPPORT)
119 #include <netinet/sctp.h>
120 #include <netinet/sctp_crc32.h>
121 #endif
122 
123 #include <netinet6/scope6_var.h>
124 
125 extern int in6_mcast_loop;
126 
127 struct ip6_exthdrs {
128 	struct mbuf *ip6e_ip6;
129 	struct mbuf *ip6e_hbh;
130 	struct mbuf *ip6e_dest1;
131 	struct mbuf *ip6e_rthdr;
132 	struct mbuf *ip6e_dest2;
133 };
134 
135 static MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
136 
137 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
138 			   struct ucred *, int);
139 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
140 	struct socket *, struct sockopt *);
141 static int ip6_getpcbopt(struct inpcb *, int, struct sockopt *);
142 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
143 	struct ucred *, int, int, int);
144 
145 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
146 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
147 	struct ip6_frag **);
148 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
149 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
150 static int ip6_getpmtu(struct route_in6 *, int,
151 	struct ifnet *, const struct in6_addr *, u_long *, int *, u_int,
152 	u_int);
153 static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
154 	u_long *, int *, u_int);
155 static int ip6_getpmtu_ctl(u_int, const struct in6_addr *, u_long *);
156 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
157 
158 /*
159  * Make an extension header from option data.  hp is the source,
160  * mp is the destination, and _ol is the optlen.
161  */
162 #define	MAKE_EXTHDR(hp, mp, _ol)					\
163     do {								\
164 	if (hp) {							\
165 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
166 		error = ip6_copyexthdr((mp), (caddr_t)(hp),		\
167 		    ((eh)->ip6e_len + 1) << 3);				\
168 		if (error)						\
169 			goto freehdrs;					\
170 		(_ol) += (*(mp))->m_len;				\
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("%s:%d: assumption failed: "\
186 			    "hdr not split: hdrsplit %d exthdrs %p",\
187 			    __func__, __LINE__, hdrsplit, &exthdrs);\
188 		*mtod((m), u_char *) = *(p);\
189 		*(p) = (i);\
190 		p = mtod((m), u_char *);\
191 		(m)->m_next = (mp)->m_next;\
192 		(mp)->m_next = (m);\
193 		(mp) = (m);\
194 	}\
195     } while (/*CONSTCOND*/ 0)
196 
197 void
in6_delayed_cksum(struct mbuf * m,uint32_t plen,u_short offset)198 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
199 {
200 	u_short csum;
201 
202 	csum = in_cksum_skip(m, offset + plen, offset);
203 	if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
204 		csum = 0xffff;
205 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
206 
207 	if (offset + sizeof(csum) > m->m_len)
208 		m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
209 	else
210 		*(u_short *)mtodo(m, offset) = csum;
211 }
212 
213 static void
ip6_output_delayed_csum(struct mbuf * m,struct ifnet * ifp,int csum_flags,int plen,int optlen)214 ip6_output_delayed_csum(struct mbuf *m, struct ifnet *ifp, int csum_flags,
215     int plen, int optlen)
216 {
217 
218 	KASSERT((plen >= optlen), ("%s:%d: plen %d < optlen %d, m %p, ifp %p "
219 	    "csum_flags %#x",
220 	    __func__, __LINE__, plen, optlen, m, ifp, csum_flags));
221 
222 	if (csum_flags & CSUM_DELAY_DATA_IPV6) {
223 		in6_delayed_cksum(m, plen - optlen,
224 		    sizeof(struct ip6_hdr) + optlen);
225 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
226 	}
227 #if defined(SCTP) || defined(SCTP_SUPPORT)
228 	if (csum_flags & CSUM_SCTP_IPV6) {
229 		sctp_delayed_cksum(m, sizeof(struct ip6_hdr) + optlen);
230 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
231 	}
232 #endif
233 }
234 
235 int
ip6_fragment(struct ifnet * ifp,struct mbuf * m0,int hlen,u_char nextproto,int fraglen,uint32_t id)236 ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
237     int fraglen , uint32_t id)
238 {
239 	struct mbuf *m, **mnext, *m_frgpart;
240 	struct ip6_hdr *ip6, *mhip6;
241 	struct ip6_frag *ip6f;
242 	int off;
243 	int error;
244 	int tlen = m0->m_pkthdr.len;
245 
246 	KASSERT((fraglen % 8 == 0), ("Fragment length must be a multiple of 8"));
247 
248 	m = m0;
249 	ip6 = mtod(m, struct ip6_hdr *);
250 	mnext = &m->m_nextpkt;
251 
252 	for (off = hlen; off < tlen; off += fraglen) {
253 		m = m_gethdr(M_NOWAIT, MT_DATA);
254 		if (!m) {
255 			IP6STAT_INC(ip6s_odropped);
256 			return (ENOBUFS);
257 		}
258 
259 		/*
260 		 * Make sure the complete packet header gets copied
261 		 * from the originating mbuf to the newly created
262 		 * mbuf. This also ensures that existing firewall
263 		 * classification(s), VLAN tags and so on get copied
264 		 * to the resulting fragmented packet(s):
265 		 */
266 		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
267 			m_free(m);
268 			IP6STAT_INC(ip6s_odropped);
269 			return (ENOBUFS);
270 		}
271 
272 		*mnext = m;
273 		mnext = &m->m_nextpkt;
274 		m->m_data += max_linkhdr;
275 		mhip6 = mtod(m, struct ip6_hdr *);
276 		*mhip6 = *ip6;
277 		m->m_len = sizeof(*mhip6);
278 		error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
279 		if (error) {
280 			IP6STAT_INC(ip6s_odropped);
281 			return (error);
282 		}
283 		ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
284 		if (off + fraglen >= tlen)
285 			fraglen = tlen - off;
286 		else
287 			ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
288 		mhip6->ip6_plen = htons((u_short)(fraglen + hlen +
289 		    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
290 		if ((m_frgpart = m_copym(m0, off, fraglen, M_NOWAIT)) == NULL) {
291 			IP6STAT_INC(ip6s_odropped);
292 			return (ENOBUFS);
293 		}
294 		m_cat(m, m_frgpart);
295 		m->m_pkthdr.len = fraglen + hlen + sizeof(*ip6f);
296 		ip6f->ip6f_reserved = 0;
297 		ip6f->ip6f_ident = id;
298 		ip6f->ip6f_nxt = nextproto;
299 		IP6STAT_INC(ip6s_ofragments);
300 		in6_ifstat_inc(ifp, ifs6_out_fragcreat);
301 	}
302 
303 	return (0);
304 }
305 
306 static int
ip6_output_send(struct inpcb * inp,struct ifnet * ifp,struct ifnet * origifp,struct mbuf * m,struct sockaddr_in6 * dst,struct route_in6 * ro,bool stamp_tag)307 ip6_output_send(struct inpcb *inp, struct ifnet *ifp, struct ifnet *origifp,
308     struct mbuf *m, struct sockaddr_in6 *dst, struct route_in6 *ro,
309     bool stamp_tag)
310 {
311 #ifdef KERN_TLS
312 	struct ktls_session *tls = NULL;
313 #endif
314 	struct m_snd_tag *mst;
315 	int error;
316 
317 	MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
318 	mst = NULL;
319 
320 #ifdef KERN_TLS
321 	/*
322 	 * If this is an unencrypted TLS record, save a reference to
323 	 * the record.  This local reference is used to call
324 	 * ktls_output_eagain after the mbuf has been freed (thus
325 	 * dropping the mbuf's reference) in if_output.
326 	 */
327 	if (m->m_next != NULL && mbuf_has_tls_session(m->m_next)) {
328 		tls = ktls_hold(m->m_next->m_epg_tls);
329 		mst = tls->snd_tag;
330 
331 		/*
332 		 * If a TLS session doesn't have a valid tag, it must
333 		 * have had an earlier ifp mismatch, so drop this
334 		 * packet.
335 		 */
336 		if (mst == NULL) {
337 			m_freem(m);
338 			error = EAGAIN;
339 			goto done;
340 		}
341 		/*
342 		 * Always stamp tags that include NIC ktls.
343 		 */
344 		stamp_tag = true;
345 	}
346 #endif
347 #ifdef RATELIMIT
348 	if (inp != NULL && mst == NULL) {
349 		if ((inp->inp_flags2 & INP_RATE_LIMIT_CHANGED) != 0 ||
350 		    (inp->inp_snd_tag != NULL &&
351 		    inp->inp_snd_tag->ifp != ifp))
352 			in_pcboutput_txrtlmt(inp, ifp, m);
353 
354 		if (inp->inp_snd_tag != NULL)
355 			mst = inp->inp_snd_tag;
356 	}
357 #endif
358 	if (stamp_tag && mst != NULL) {
359 		KASSERT(m->m_pkthdr.rcvif == NULL,
360 		    ("trying to add a send tag to a forwarded packet"));
361 		if (mst->ifp != ifp) {
362 			m_freem(m);
363 			error = EAGAIN;
364 			goto done;
365 		}
366 
367 		/* stamp send tag on mbuf */
368 		m->m_pkthdr.snd_tag = m_snd_tag_ref(mst);
369 		m->m_pkthdr.csum_flags |= CSUM_SND_TAG;
370 	}
371 
372 	error = nd6_output_ifp(ifp, origifp, m, dst, (struct route *)ro);
373 
374 done:
375 	/* Check for route change invalidating send tags. */
376 #ifdef KERN_TLS
377 	if (tls != NULL) {
378 		if (error == EAGAIN)
379 			error = ktls_output_eagain(inp, tls);
380 		ktls_free(tls);
381 	}
382 #endif
383 #ifdef RATELIMIT
384 	if (error == EAGAIN)
385 		in_pcboutput_eagain(inp);
386 #endif
387 	return (error);
388 }
389 
390 /*
391  * IP6 output.
392  * The packet in mbuf chain m contains a skeletal IP6 header (with pri, len,
393  * nxt, hlim, src, dst).
394  * This function may modify ver and hlim only.
395  * The mbuf chain containing the packet will be freed.
396  * The mbuf opt, if present, will not be freed.
397  * If route_in6 ro is present and has ro_nh initialized, route lookup would be
398  * skipped and ro->ro_nh would be used. If ro is present but ro->ro_nh is NULL,
399  * then result of route lookup is stored in ro->ro_nh.
400  *
401  * Type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and nd_ifinfo.linkmtu
402  * is uint32_t.  So we use u_long to hold largest one, which is rt_mtu.
403  *
404  * ifpp - XXX: just for statistics
405  */
406 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)407 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
408     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
409     struct ifnet **ifpp, struct inpcb *inp)
410 {
411 	struct ip6_hdr *ip6;
412 	struct ifnet *ifp, *origifp;
413 	struct mbuf *m = m0;
414 	struct mbuf *mprev;
415 	struct route_in6 *ro_pmtu;
416 	struct nhop_object *nh;
417 	struct sockaddr_in6 *dst, sin6, src_sa, dst_sa;
418 	struct in6_addr odst;
419 	u_char *nexthdrp;
420 	int tlen, len;
421 	int error = 0;
422 	int vlan_pcp = -1;
423 	struct in6_ifaddr *ia = NULL;
424 	u_long mtu;
425 	int alwaysfrag, dontfrag;
426 	u_int32_t optlen, plen = 0, unfragpartlen;
427 	struct ip6_exthdrs exthdrs;
428 	struct in6_addr src0, dst0;
429 	u_int32_t zone;
430 	bool hdrsplit;
431 	int sw_csum, tso;
432 	int needfiblookup;
433 	uint32_t fibnum;
434 	struct m_tag *fwd_tag = NULL;
435 	uint32_t id;
436 
437 	NET_EPOCH_ASSERT();
438 
439 	if (inp != NULL) {
440 		INP_LOCK_ASSERT(inp);
441 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
442 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
443 			/* Unconditionally set flowid. */
444 			m->m_pkthdr.flowid = inp->inp_flowid;
445 			M_HASHTYPE_SET(m, inp->inp_flowtype);
446 		}
447 		if ((inp->inp_flags2 & INP_2PCP_SET) != 0)
448 			vlan_pcp = (inp->inp_flags2 & INP_2PCP_MASK) >>
449 			    INP_2PCP_SHIFT;
450 #ifdef NUMA
451 		m->m_pkthdr.numa_domain = inp->inp_numa_domain;
452 #endif
453 	}
454 
455 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
456 	/*
457 	 * IPSec checking which handles several cases.
458 	 * FAST IPSEC: We re-injected the packet.
459 	 * XXX: need scope argument.
460 	 */
461 	if (IPSEC_ENABLED(ipv6)) {
462 		struct mbuf *m1;
463 
464 		error = mb_unmapped_to_ext(m, &m1);
465 		if (error != 0) {
466 			if (error == ENOMEM) {
467 				IP6STAT_INC(ip6s_odropped);
468 				error = ENOBUFS;
469 				goto bad;
470 			}
471 			/* XXXKIB */
472 			goto no_ipsec;
473 		}
474 		m = m1;
475 		if ((error = IPSEC_OUTPUT(ipv6, m, inp)) != 0) {
476 			if (error == EINPROGRESS)
477 				error = 0;
478 			goto done;
479 		}
480 no_ipsec:;
481 	}
482 #endif /* IPSEC */
483 
484 	/* Source address validation. */
485 	ip6 = mtod(m, struct ip6_hdr *);
486 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
487 	    (flags & IPV6_UNSPECSRC) == 0) {
488 		error = EOPNOTSUPP;
489 		IP6STAT_INC(ip6s_badscope);
490 		goto bad;
491 	}
492 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
493 		error = EOPNOTSUPP;
494 		IP6STAT_INC(ip6s_badscope);
495 		goto bad;
496 	}
497 
498 	/*
499 	 * If we are given packet options to add extension headers prepare them.
500 	 * Calculate the total length of the extension header chain.
501 	 * Keep the length of the unfragmentable part for fragmentation.
502 	 */
503 	bzero(&exthdrs, sizeof(exthdrs));
504 	optlen = 0;
505 	unfragpartlen = sizeof(struct ip6_hdr);
506 	if (opt) {
507 		/* Hop-by-Hop options header. */
508 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh, optlen);
509 
510 		/* Destination options header (1st part). */
511 		if (opt->ip6po_rthdr) {
512 #ifndef RTHDR_SUPPORT_IMPLEMENTED
513 			/*
514 			 * If there is a routing header, discard the packet
515 			 * right away here. RH0/1 are obsolete and we do not
516 			 * currently support RH2/3/4.
517 			 * People trying to use RH253/254 may want to disable
518 			 * this check.
519 			 * The moment we do support any routing header (again)
520 			 * this block should check the routing type more
521 			 * selectively.
522 			 */
523 			error = EINVAL;
524 			goto bad;
525 #endif
526 
527 			/*
528 			 * Destination options header (1st part).
529 			 * This only makes sense with a routing header.
530 			 * See Section 9.2 of RFC 3542.
531 			 * Disabling this part just for MIP6 convenience is
532 			 * a bad idea.  We need to think carefully about a
533 			 * way to make the advanced API coexist with MIP6
534 			 * options, which might automatically be inserted in
535 			 * the kernel.
536 			 */
537 			MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1,
538 			    optlen);
539 		}
540 		/* Routing header. */
541 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr, optlen);
542 
543 		unfragpartlen += optlen;
544 
545 		/*
546 		 * NOTE: we don't add AH/ESP length here (done in
547 		 * ip6_ipsec_output()).
548 		 */
549 
550 		/* Destination options header (2nd part). */
551 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2, optlen);
552 	}
553 
554 	/*
555 	 * If there is at least one extension header,
556 	 * separate IP6 header from the payload.
557 	 */
558 	hdrsplit = false;
559 	if (optlen) {
560 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
561 			m = NULL;
562 			goto freehdrs;
563 		}
564 		m = exthdrs.ip6e_ip6;
565 		ip6 = mtod(m, struct ip6_hdr *);
566 		hdrsplit = true;
567 	}
568 
569 	/* Adjust mbuf packet header length. */
570 	m->m_pkthdr.len += optlen;
571 	plen = m->m_pkthdr.len - sizeof(*ip6);
572 
573 	/* If this is a jumbo payload, insert a jumbo payload option. */
574 	if (plen > IPV6_MAXPACKET) {
575 		if (!hdrsplit) {
576 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
577 				m = NULL;
578 				goto freehdrs;
579 			}
580 			m = exthdrs.ip6e_ip6;
581 			ip6 = mtod(m, struct ip6_hdr *);
582 			hdrsplit = true;
583 		}
584 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
585 			goto freehdrs;
586 		ip6->ip6_plen = 0;
587 	} else
588 		ip6->ip6_plen = htons(plen);
589 	nexthdrp = &ip6->ip6_nxt;
590 
591 	if (optlen) {
592 		/*
593 		 * Concatenate headers and fill in next header fields.
594 		 * Here we have, on "m"
595 		 *	IPv6 payload
596 		 * and we insert headers accordingly.
597 		 * Finally, we should be getting:
598 		 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload].
599 		 *
600 		 * During the header composing process "m" points to IPv6
601 		 * header.  "mprev" points to an extension header prior to esp.
602 		 */
603 		mprev = m;
604 
605 		/*
606 		 * We treat dest2 specially.  This makes IPsec processing
607 		 * much easier.  The goal here is to make mprev point the
608 		 * mbuf prior to dest2.
609 		 *
610 		 * Result: IPv6 dest2 payload.
611 		 * m and mprev will point to IPv6 header.
612 		 */
613 		if (exthdrs.ip6e_dest2) {
614 			if (!hdrsplit)
615 				panic("%s:%d: assumption failed: "
616 				    "hdr not split: hdrsplit %d exthdrs %p",
617 				    __func__, __LINE__, hdrsplit, &exthdrs);
618 			exthdrs.ip6e_dest2->m_next = m->m_next;
619 			m->m_next = exthdrs.ip6e_dest2;
620 			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
621 			ip6->ip6_nxt = IPPROTO_DSTOPTS;
622 		}
623 
624 		/*
625 		 * Result: IPv6 hbh dest1 rthdr dest2 payload.
626 		 * m will point to IPv6 header.  mprev will point to the
627 		 * extension header prior to dest2 (rthdr in the above case).
628 		 */
629 		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
630 		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
631 			   IPPROTO_DSTOPTS);
632 		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
633 			   IPPROTO_ROUTING);
634 	}
635 
636 	IP6STAT_INC(ip6s_localout);
637 
638 	/* Route packet. */
639 	ro_pmtu = ro;
640 	if (opt && opt->ip6po_rthdr)
641 		ro = &opt->ip6po_route;
642 	if (ro != NULL)
643 		dst = (struct sockaddr_in6 *)&ro->ro_dst;
644 	else
645 		dst = &sin6;
646 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
647 
648 again:
649 	/*
650 	 * If specified, try to fill in the traffic class field.
651 	 * Do not override if a non-zero value is already set.
652 	 * We check the diffserv field and the ECN field separately.
653 	 */
654 	if (opt && opt->ip6po_tclass >= 0) {
655 		int mask = 0;
656 
657 		if (IPV6_DSCP(ip6) == 0)
658 			mask |= 0xfc;
659 		if (IPV6_ECN(ip6) == 0)
660 			mask |= 0x03;
661 		if (mask != 0)
662 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
663 	}
664 
665 	/* Fill in or override the hop limit field, if necessary. */
666 	if (opt && opt->ip6po_hlim != -1)
667 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
668 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
669 		if (im6o != NULL)
670 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
671 		else
672 			ip6->ip6_hlim = V_ip6_defmcasthlim;
673 	}
674 
675 	if (ro == NULL || ro->ro_nh == NULL) {
676 		bzero(dst, sizeof(*dst));
677 		dst->sin6_family = AF_INET6;
678 		dst->sin6_len = sizeof(*dst);
679 		dst->sin6_addr = ip6->ip6_dst;
680 	}
681 	/*
682 	 * Validate route against routing table changes.
683 	 * Make sure that the address family is set in route.
684 	 */
685 	nh = NULL;
686 	ifp = NULL;
687 	mtu = 0;
688 	if (ro != NULL) {
689 		if (ro->ro_nh != NULL && inp != NULL) {
690 			ro->ro_dst.sin6_family = AF_INET6; /* XXX KASSERT? */
691 			NH_VALIDATE((struct route *)ro, &inp->inp_rt_cookie,
692 			    fibnum);
693 		}
694 		if (ro->ro_nh != NULL && fwd_tag == NULL &&
695 		    (!NH_IS_VALID(ro->ro_nh) ||
696 		    ro->ro_dst.sin6_family != AF_INET6 ||
697 		    !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)))
698 			RO_INVALIDATE_CACHE(ro);
699 
700 		if (ro->ro_nh != NULL && fwd_tag == NULL &&
701 		    ro->ro_dst.sin6_family == AF_INET6 &&
702 		    IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)) {
703 			/* Nexthop is valid and contains valid ifp */
704 			nh = ro->ro_nh;
705 		} else {
706 			if (ro->ro_lle)
707 				LLE_FREE(ro->ro_lle);	/* zeros ro_lle */
708 			ro->ro_lle = NULL;
709 			if (fwd_tag == NULL) {
710 				bzero(&dst_sa, sizeof(dst_sa));
711 				dst_sa.sin6_family = AF_INET6;
712 				dst_sa.sin6_len = sizeof(dst_sa);
713 				dst_sa.sin6_addr = ip6->ip6_dst;
714 			}
715 			error = in6_selectroute(&dst_sa, opt, im6o, ro, &ifp,
716 			    &nh, fibnum, m->m_pkthdr.flowid);
717 			if (error != 0) {
718 				IP6STAT_INC(ip6s_noroute);
719 				if (ifp != NULL)
720 					in6_ifstat_inc(ifp, ifs6_out_discard);
721 				goto bad;
722 			}
723 			/*
724 			 * At this point at least @ifp is not NULL
725 			 * Can be the case when dst is multicast, link-local or
726 			 * interface is explicitly specificed by the caller.
727 			 */
728 		}
729 		if (nh == NULL) {
730 			/*
731 			 * If in6_selectroute() does not return a nexthop
732 			 * dst may not have been updated.
733 			 */
734 			*dst = dst_sa;	/* XXX */
735 			origifp = ifp;
736 			mtu = ifp->if_mtu;
737 		} else {
738 			ifp = nh->nh_ifp;
739 			origifp = nh->nh_aifp;
740 			ia = (struct in6_ifaddr *)(nh->nh_ifa);
741 			counter_u64_add(nh->nh_pksent, 1);
742 		}
743 	} else {
744 		struct nhop_object *nh;
745 		struct in6_addr kdst;
746 		uint32_t scopeid;
747 
748 		if (fwd_tag == NULL) {
749 			bzero(&dst_sa, sizeof(dst_sa));
750 			dst_sa.sin6_family = AF_INET6;
751 			dst_sa.sin6_len = sizeof(dst_sa);
752 			dst_sa.sin6_addr = ip6->ip6_dst;
753 		}
754 
755 		if (IN6_IS_ADDR_MULTICAST(&dst_sa.sin6_addr) &&
756 		    im6o != NULL &&
757 		    (ifp = im6o->im6o_multicast_ifp) != NULL) {
758 			/* We do not need a route lookup. */
759 			*dst = dst_sa;	/* XXX */
760 			origifp = ifp;
761 			goto nonh6lookup;
762 		}
763 
764 		in6_splitscope(&dst_sa.sin6_addr, &kdst, &scopeid);
765 
766 		if (IN6_IS_ADDR_MC_LINKLOCAL(&dst_sa.sin6_addr) ||
767 		    IN6_IS_ADDR_MC_NODELOCAL(&dst_sa.sin6_addr)) {
768 			if (scopeid > 0) {
769 				ifp = in6_getlinkifnet(scopeid);
770 				if (ifp == NULL) {
771 					error = EHOSTUNREACH;
772 					goto bad;
773 				}
774 				*dst = dst_sa;	/* XXX */
775 				origifp = ifp;
776 				goto nonh6lookup;
777 			}
778 		}
779 
780 		nh = fib6_lookup(fibnum, &kdst, scopeid, NHR_NONE,
781 		    m->m_pkthdr.flowid);
782 		if (nh == NULL) {
783 			IP6STAT_INC(ip6s_noroute);
784 			/* No ifp in6_ifstat_inc(ifp, ifs6_out_discard); */
785 			error = EHOSTUNREACH;
786 			goto bad;
787 		}
788 
789 		ifp = nh->nh_ifp;
790 		origifp = nh->nh_aifp;
791 		ia = ifatoia6(nh->nh_ifa);
792 		if (nh->nh_flags & NHF_GATEWAY)
793 			dst->sin6_addr = nh->gw6_sa.sin6_addr;
794 		else if (fwd_tag != NULL)
795 			dst->sin6_addr = dst_sa.sin6_addr;
796 nonh6lookup:
797 		;
798 	}
799 	/*
800 	 * At this point ifp MUST be pointing to the valid transmit ifp.
801 	 * origifp MUST be valid and pointing to either the same ifp or,
802 	 * in case of loopback output, to the interface which ip6_src
803 	 * belongs to.
804 	 * Examples:
805 	 *  fe80::1%em0 -> fe80::2%em0 -> ifp=em0, origifp=em0
806 	 *  fe80::1%em0 -> fe80::1%em0 -> ifp=lo0, origifp=em0
807 	 *  ::1 -> ::1 -> ifp=lo0, origifp=lo0
808 	 *
809 	 * mtu can be 0 and will be refined later.
810 	 */
811 	KASSERT((ifp != NULL), ("output interface must not be NULL"));
812 	KASSERT((origifp != NULL), ("output address interface must not be NULL"));
813 
814 	if ((flags & IPV6_FORWARDING) == 0) {
815 		/* XXX: the FORWARDING flag can be set for mrouting. */
816 		in6_ifstat_inc(ifp, ifs6_out_request);
817 	}
818 
819 	/* Setup data structures for scope ID checks. */
820 	src0 = ip6->ip6_src;
821 	bzero(&src_sa, sizeof(src_sa));
822 	src_sa.sin6_family = AF_INET6;
823 	src_sa.sin6_len = sizeof(src_sa);
824 	src_sa.sin6_addr = ip6->ip6_src;
825 
826 	dst0 = ip6->ip6_dst;
827 	/* Re-initialize to be sure. */
828 	bzero(&dst_sa, sizeof(dst_sa));
829 	dst_sa.sin6_family = AF_INET6;
830 	dst_sa.sin6_len = sizeof(dst_sa);
831 	dst_sa.sin6_addr = ip6->ip6_dst;
832 
833 	/* Check for valid scope ID. */
834 	if (in6_setscope(&src0, origifp, &zone) == 0 &&
835 	    sa6_recoverscope(&src_sa) == 0 && zone == src_sa.sin6_scope_id &&
836 	    in6_setscope(&dst0, origifp, &zone) == 0 &&
837 	    sa6_recoverscope(&dst_sa) == 0 && zone == dst_sa.sin6_scope_id) {
838 		/*
839 		 * The outgoing interface is in the zone of the source
840 		 * and destination addresses.
841 		 *
842 		 */
843 	} else if ((origifp->if_flags & IFF_LOOPBACK) == 0 ||
844 	    sa6_recoverscope(&src_sa) != 0 ||
845 	    sa6_recoverscope(&dst_sa) != 0 ||
846 	    dst_sa.sin6_scope_id == 0 ||
847 	    (src_sa.sin6_scope_id != 0 &&
848 	    src_sa.sin6_scope_id != dst_sa.sin6_scope_id) ||
849 	    ifnet_byindex(dst_sa.sin6_scope_id) == NULL) {
850 		/*
851 		 * If the destination network interface is not a
852 		 * loopback interface, or the destination network
853 		 * address has no scope ID, or the source address has
854 		 * a scope ID set which is different from the
855 		 * destination address one, or there is no network
856 		 * interface representing this scope ID, the address
857 		 * pair is considered invalid.
858 		 */
859 		IP6STAT_INC(ip6s_badscope);
860 		in6_ifstat_inc(origifp, ifs6_out_discard);
861 		if (error == 0)
862 			error = EHOSTUNREACH; /* XXX */
863 		goto bad;
864 	}
865 	/* All scope ID checks are successful. */
866 
867 	if (nh && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
868 		if (opt && opt->ip6po_nextroute.ro_nh) {
869 			/*
870 			 * The nexthop is explicitly specified by the
871 			 * application.  We assume the next hop is an IPv6
872 			 * address.
873 			 */
874 			dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
875 		}
876 		else if ((nh->nh_flags & NHF_GATEWAY))
877 			dst = &nh->gw6_sa;
878 	}
879 
880 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
881 		m->m_flags &= ~(M_BCAST | M_MCAST); /* Just in case. */
882 	} else {
883 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
884 		in6_ifstat_inc(ifp, ifs6_out_mcast);
885 
886 		/* Confirm that the outgoing interface supports multicast. */
887 		if (!(ifp->if_flags & IFF_MULTICAST)) {
888 			IP6STAT_INC(ip6s_noroute);
889 			in6_ifstat_inc(ifp, ifs6_out_discard);
890 			error = ENETUNREACH;
891 			goto bad;
892 		}
893 		if ((im6o == NULL && in6_mcast_loop) ||
894 		    (im6o && im6o->im6o_multicast_loop)) {
895 			/*
896 			 * Loop back multicast datagram if not expressly
897 			 * forbidden to do so, even if we have not joined
898 			 * the address; protocols will filter it later,
899 			 * thus deferring a hash lookup and lock acquisition
900 			 * at the expense of an m_copym().
901 			 */
902 			ip6_mloopback(ifp, m);
903 		} else {
904 			/*
905 			 * If we are acting as a multicast router, perform
906 			 * multicast forwarding as if the packet had just
907 			 * arrived on the interface to which we are about
908 			 * to send.  The multicast forwarding function
909 			 * recursively calls this function, using the
910 			 * IPV6_FORWARDING flag to prevent infinite recursion.
911 			 *
912 			 * Multicasts that are looped back by ip6_mloopback(),
913 			 * above, will be forwarded by the ip6_input() routine,
914 			 * if necessary.
915 			 */
916 			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
917 				/*
918 				 * XXX: ip6_mforward expects that rcvif is NULL
919 				 * when it is called from the originating path.
920 				 * However, it may not always be the case.
921 				 */
922 				m->m_pkthdr.rcvif = NULL;
923 				if (ip6_mforward(ip6, ifp, m) != 0) {
924 					m_freem(m);
925 					goto done;
926 				}
927 			}
928 		}
929 		/*
930 		 * Multicasts with a hoplimit of zero may be looped back,
931 		 * above, but must not be transmitted on a network.
932 		 * Also, multicasts addressed to the loopback interface
933 		 * are not sent -- the above call to ip6_mloopback() will
934 		 * loop back a copy if this host actually belongs to the
935 		 * destination group on the loopback interface.
936 		 */
937 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
938 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
939 			m_freem(m);
940 			goto done;
941 		}
942 	}
943 
944 	/*
945 	 * Fill the outgoing inteface to tell the upper layer
946 	 * to increment per-interface statistics.
947 	 */
948 	if (ifpp)
949 		*ifpp = ifp;
950 
951 	/* Determine path MTU. */
952 	if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &ip6->ip6_dst,
953 		    &mtu, &alwaysfrag, fibnum, *nexthdrp)) != 0)
954 		goto bad;
955 	KASSERT(mtu > 0, ("%s:%d: mtu %ld, ro_pmtu %p ro %p ifp %p "
956 	    "alwaysfrag %d fibnum %u\n", __func__, __LINE__, mtu, ro_pmtu, ro,
957 	    ifp, alwaysfrag, fibnum));
958 
959 	/*
960 	 * The caller of this function may specify to use the minimum MTU
961 	 * in some cases.
962 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
963 	 * setting.  The logic is a bit complicated; by default, unicast
964 	 * packets will follow path MTU while multicast packets will be sent at
965 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
966 	 * including unicast ones will be sent at the minimum MTU.  Multicast
967 	 * packets will always be sent at the minimum MTU unless
968 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
969 	 * See RFC 3542 for more details.
970 	 */
971 	if (mtu > IPV6_MMTU) {
972 		if ((flags & IPV6_MINMTU))
973 			mtu = IPV6_MMTU;
974 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
975 			mtu = IPV6_MMTU;
976 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
977 			 (opt == NULL ||
978 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
979 			mtu = IPV6_MMTU;
980 		}
981 	}
982 
983 	/*
984 	 * Clear embedded scope identifiers if necessary.
985 	 * in6_clearscope() will touch the addresses only when necessary.
986 	 */
987 	in6_clearscope(&ip6->ip6_src);
988 	in6_clearscope(&ip6->ip6_dst);
989 
990 	/*
991 	 * If the outgoing packet contains a hop-by-hop options header,
992 	 * it must be examined and processed even by the source node.
993 	 * (RFC 2460, section 4.)
994 	 */
995 	if (exthdrs.ip6e_hbh) {
996 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
997 		u_int32_t dummy; /* XXX unused */
998 		u_int32_t plen = 0; /* XXX: ip6_process will check the value */
999 
1000 #ifdef DIAGNOSTIC
1001 		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
1002 			panic("ip6e_hbh is not contiguous");
1003 #endif
1004 		/*
1005 		 *  XXX: if we have to send an ICMPv6 error to the sender,
1006 		 *       we need the M_LOOP flag since icmp6_error() expects
1007 		 *       the IPv6 and the hop-by-hop options header are
1008 		 *       contiguous unless the flag is set.
1009 		 */
1010 		m->m_flags |= M_LOOP;
1011 		m->m_pkthdr.rcvif = ifp;
1012 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
1013 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
1014 		    &dummy, &plen) < 0) {
1015 			/* m was already freed at this point. */
1016 			error = EINVAL;/* better error? */
1017 			goto done;
1018 		}
1019 		m->m_flags &= ~M_LOOP; /* XXX */
1020 		m->m_pkthdr.rcvif = NULL;
1021 	}
1022 
1023 	/* Jump over all PFIL processing if hooks are not active. */
1024 	if (!PFIL_HOOKED_OUT(V_inet6_pfil_head))
1025 		goto passout;
1026 
1027 	odst = ip6->ip6_dst;
1028 	/* Run through list of hooks for output packets. */
1029 	switch (pfil_mbuf_out(V_inet6_pfil_head, &m, ifp, inp)) {
1030 	case PFIL_PASS:
1031 		ip6 = mtod(m, struct ip6_hdr *);
1032 		break;
1033 	case PFIL_DROPPED:
1034 		error = EACCES;
1035 		/* FALLTHROUGH */
1036 	case PFIL_CONSUMED:
1037 		goto done;
1038 	}
1039 
1040 	needfiblookup = 0;
1041 	/* See if destination IP address was changed by packet filter. */
1042 	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
1043 		m->m_flags |= M_SKIP_FIREWALL;
1044 		/* If destination is now ourself drop to ip6_input(). */
1045 		if (in6_localip(&ip6->ip6_dst)) {
1046 			m->m_flags |= M_FASTFWD_OURS;
1047 			if (m->m_pkthdr.rcvif == NULL)
1048 				m->m_pkthdr.rcvif = V_loif;
1049 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1050 				m->m_pkthdr.csum_flags |=
1051 				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
1052 				m->m_pkthdr.csum_data = 0xffff;
1053 			}
1054 #if defined(SCTP) || defined(SCTP_SUPPORT)
1055 			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
1056 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
1057 #endif
1058 			error = netisr_queue(NETISR_IPV6, m);
1059 			goto done;
1060 		} else {
1061 			if (ro != NULL)
1062 				RO_INVALIDATE_CACHE(ro);
1063 			needfiblookup = 1; /* Redo the routing table lookup. */
1064 		}
1065 	}
1066 	/* See if fib was changed by packet filter. */
1067 	if (fibnum != M_GETFIB(m)) {
1068 		m->m_flags |= M_SKIP_FIREWALL;
1069 		fibnum = M_GETFIB(m);
1070 		if (ro != NULL)
1071 			RO_INVALIDATE_CACHE(ro);
1072 		needfiblookup = 1;
1073 	}
1074 	if (needfiblookup)
1075 		goto again;
1076 
1077 	/* See if local, if yes, send it to netisr. */
1078 	if (m->m_flags & M_FASTFWD_OURS) {
1079 		if (m->m_pkthdr.rcvif == NULL)
1080 			m->m_pkthdr.rcvif = V_loif;
1081 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1082 			m->m_pkthdr.csum_flags |=
1083 			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
1084 			m->m_pkthdr.csum_data = 0xffff;
1085 		}
1086 #if defined(SCTP) || defined(SCTP_SUPPORT)
1087 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
1088 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
1089 #endif
1090 		error = netisr_queue(NETISR_IPV6, m);
1091 		goto done;
1092 	}
1093 	/* Or forward to some other address? */
1094 	if ((m->m_flags & M_IP6_NEXTHOP) &&
1095 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
1096 		if (ro != NULL)
1097 			dst = (struct sockaddr_in6 *)&ro->ro_dst;
1098 		else
1099 			dst = &sin6;
1100 		bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
1101 		m->m_flags |= M_SKIP_FIREWALL;
1102 		m->m_flags &= ~M_IP6_NEXTHOP;
1103 		m_tag_delete(m, fwd_tag);
1104 		goto again;
1105 	}
1106 
1107 passout:
1108 	if (vlan_pcp > -1)
1109 		EVL_APPLY_PRI(m, vlan_pcp);
1110 
1111 	/* Ensure the packet data is mapped if the interface requires it. */
1112 	if ((ifp->if_capenable & IFCAP_MEXTPG) == 0) {
1113 		struct mbuf *m1;
1114 
1115 		error = mb_unmapped_to_ext(m, &m1);
1116 		if (error != 0) {
1117 			if (error == EINVAL) {
1118 				if_printf(ifp, "TLS packet\n");
1119 				/* XXXKIB */
1120 			} else if (error == ENOMEM) {
1121 				error = ENOBUFS;
1122 			}
1123 			IP6STAT_INC(ip6s_odropped);
1124 			return (error);
1125 		} else {
1126 			m = m1;
1127 		}
1128 	}
1129 
1130 	/*
1131 	 * Send the packet to the outgoing interface.
1132 	 * If necessary, do IPv6 fragmentation before sending.
1133 	 *
1134 	 * The logic here is rather complex:
1135 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
1136 	 * 1-a:	send as is if tlen <= path mtu
1137 	 * 1-b:	fragment if tlen > path mtu
1138 	 *
1139 	 * 2: if user asks us not to fragment (dontfrag == 1)
1140 	 * 2-a:	send as is if tlen <= interface mtu
1141 	 * 2-b:	error if tlen > interface mtu
1142 	 *
1143 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
1144 	 *	always fragment
1145 	 *
1146 	 * 4: if dontfrag == 1 && alwaysfrag == 1
1147 	 *	error, as we cannot handle this conflicting request.
1148 	 */
1149 	sw_csum = m->m_pkthdr.csum_flags;
1150 	if (!hdrsplit) {
1151 		tso = ((sw_csum & ifp->if_hwassist &
1152 		    (CSUM_TSO | CSUM_INNER_TSO)) != 0) ? 1 : 0;
1153 		sw_csum &= ~ifp->if_hwassist;
1154 	} else
1155 		tso = 0;
1156 	/*
1157 	 * If we added extension headers, we will not do TSO and calculate the
1158 	 * checksums ourselves for now.
1159 	 * XXX-BZ  Need a framework to know when the NIC can handle it, even
1160 	 * with ext. hdrs.
1161 	 */
1162 	ip6_output_delayed_csum(m, ifp, sw_csum, plen, optlen);
1163 	/* XXX-BZ m->m_pkthdr.csum_flags &= ~ifp->if_hwassist; */
1164 	tlen = m->m_pkthdr.len;
1165 
1166 	if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
1167 		dontfrag = 1;
1168 	else
1169 		dontfrag = 0;
1170 	if (dontfrag && alwaysfrag) {	/* Case 4. */
1171 		/* Conflicting request - can't transmit. */
1172 		error = EMSGSIZE;
1173 		goto bad;
1174 	}
1175 	if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {	/* Case 2-b. */
1176 		/*
1177 		 * Even if the DONTFRAG option is specified, we cannot send the
1178 		 * packet when the data length is larger than the MTU of the
1179 		 * outgoing interface.
1180 		 * Notify the error by sending IPV6_PATHMTU ancillary data if
1181 		 * application wanted to know the MTU value. Also return an
1182 		 * error code (this is not described in the API spec).
1183 		 */
1184 		if (inp != NULL)
1185 			ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
1186 		error = EMSGSIZE;
1187 		goto bad;
1188 	}
1189 
1190 	/* Transmit packet without fragmentation. */
1191 	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* Cases 1-a and 2-a. */
1192 		struct in6_ifaddr *ia6;
1193 
1194 		ip6 = mtod(m, struct ip6_hdr *);
1195 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
1196 		if (ia6) {
1197 			/* Record statistics for this interface address. */
1198 			counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
1199 			counter_u64_add(ia6->ia_ifa.ifa_obytes,
1200 			    m->m_pkthdr.len);
1201 		}
1202 		error = ip6_output_send(inp, ifp, origifp, m, dst, ro,
1203 		    (flags & IP_NO_SND_TAG_RL) ? false : true);
1204 		goto done;
1205 	}
1206 
1207 	/* Try to fragment the packet.  Cases 1-b and 3. */
1208 	if (mtu < IPV6_MMTU) {
1209 		/* Path MTU cannot be less than IPV6_MMTU. */
1210 		error = EMSGSIZE;
1211 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
1212 		goto bad;
1213 	} else if (ip6->ip6_plen == 0) {
1214 		/* Jumbo payload cannot be fragmented. */
1215 		error = EMSGSIZE;
1216 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
1217 		goto bad;
1218 	} else {
1219 		u_char nextproto;
1220 
1221 		/*
1222 		 * Too large for the destination or interface;
1223 		 * fragment if possible.
1224 		 * Must be able to put at least 8 bytes per fragment.
1225 		 */
1226 		if (mtu > IPV6_MAXPACKET)
1227 			mtu = IPV6_MAXPACKET;
1228 
1229 		len = (mtu - unfragpartlen - sizeof(struct ip6_frag)) & ~7;
1230 		if (len < 8) {
1231 			error = EMSGSIZE;
1232 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
1233 			goto bad;
1234 		}
1235 
1236 		/*
1237 		 * If the interface will not calculate checksums on
1238 		 * fragmented packets, then do it here.
1239 		 * XXX-BZ handle the hw offloading case.  Need flags.
1240 		 */
1241 		ip6_output_delayed_csum(m, ifp, m->m_pkthdr.csum_flags, plen,
1242 		    optlen);
1243 
1244 		/*
1245 		 * Change the next header field of the last header in the
1246 		 * unfragmentable part.
1247 		 */
1248 		if (exthdrs.ip6e_rthdr) {
1249 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1250 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1251 		} else if (exthdrs.ip6e_dest1) {
1252 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1253 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1254 		} else if (exthdrs.ip6e_hbh) {
1255 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1256 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1257 		} else {
1258 			ip6 = mtod(m, struct ip6_hdr *);
1259 			nextproto = ip6->ip6_nxt;
1260 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
1261 		}
1262 
1263 		/*
1264 		 * Loop through length of segment after first fragment,
1265 		 * make new header and copy data of each part and link onto
1266 		 * chain.
1267 		 */
1268 		m0 = m;
1269 		id = htonl(ip6_randomid());
1270 		error = ip6_fragment(ifp, m, unfragpartlen, nextproto,len, id);
1271 		if (error != 0)
1272 			goto sendorfree;
1273 
1274 		in6_ifstat_inc(ifp, ifs6_out_fragok);
1275 	}
1276 
1277 	/* Remove leading garbage. */
1278 sendorfree:
1279 	m = m0->m_nextpkt;
1280 	m0->m_nextpkt = 0;
1281 	m_freem(m0);
1282 	for (; m; m = m0) {
1283 		m0 = m->m_nextpkt;
1284 		m->m_nextpkt = 0;
1285 		if (error == 0) {
1286 			/* Record statistics for this interface address. */
1287 			if (ia) {
1288 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1289 				counter_u64_add(ia->ia_ifa.ifa_obytes,
1290 				    m->m_pkthdr.len);
1291 			}
1292 			if (vlan_pcp > -1)
1293 				EVL_APPLY_PRI(m, vlan_pcp);
1294 			error = ip6_output_send(inp, ifp, origifp, m, dst, ro,
1295 			    true);
1296 		} else
1297 			m_freem(m);
1298 	}
1299 
1300 	if (error == 0)
1301 		IP6STAT_INC(ip6s_fragmented);
1302 
1303 done:
1304 	return (error);
1305 
1306 freehdrs:
1307 	m_freem(exthdrs.ip6e_hbh);	/* m_freem() checks if mbuf is NULL. */
1308 	m_freem(exthdrs.ip6e_dest1);
1309 	m_freem(exthdrs.ip6e_rthdr);
1310 	m_freem(exthdrs.ip6e_dest2);
1311 	/* FALLTHROUGH */
1312 bad:
1313 	if (m)
1314 		m_freem(m);
1315 	goto done;
1316 }
1317 
1318 static int
ip6_copyexthdr(struct mbuf ** mp,caddr_t hdr,int hlen)1319 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1320 {
1321 	struct mbuf *m;
1322 
1323 	if (hlen > MCLBYTES)
1324 		return (ENOBUFS); /* XXX */
1325 
1326 	if (hlen > MLEN)
1327 		m = m_getcl(M_NOWAIT, MT_DATA, 0);
1328 	else
1329 		m = m_get(M_NOWAIT, MT_DATA);
1330 	if (m == NULL)
1331 		return (ENOBUFS);
1332 	m->m_len = hlen;
1333 	if (hdr)
1334 		bcopy(hdr, mtod(m, caddr_t), hlen);
1335 
1336 	*mp = m;
1337 	return (0);
1338 }
1339 
1340 /*
1341  * Insert jumbo payload option.
1342  */
1343 static int
ip6_insert_jumboopt(struct ip6_exthdrs * exthdrs,u_int32_t plen)1344 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1345 {
1346 	struct mbuf *mopt;
1347 	u_char *optbuf;
1348 	u_int32_t v;
1349 
1350 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1351 
1352 	/*
1353 	 * If there is no hop-by-hop options header, allocate new one.
1354 	 * If there is one but it doesn't have enough space to store the
1355 	 * jumbo payload option, allocate a cluster to store the whole options.
1356 	 * Otherwise, use it to store the options.
1357 	 */
1358 	if (exthdrs->ip6e_hbh == NULL) {
1359 		mopt = m_get(M_NOWAIT, MT_DATA);
1360 		if (mopt == NULL)
1361 			return (ENOBUFS);
1362 		mopt->m_len = JUMBOOPTLEN;
1363 		optbuf = mtod(mopt, u_char *);
1364 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1365 		exthdrs->ip6e_hbh = mopt;
1366 	} else {
1367 		struct ip6_hbh *hbh;
1368 
1369 		mopt = exthdrs->ip6e_hbh;
1370 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1371 			/*
1372 			 * XXX assumption:
1373 			 * - exthdrs->ip6e_hbh is not referenced from places
1374 			 *   other than exthdrs.
1375 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1376 			 */
1377 			int oldoptlen = mopt->m_len;
1378 			struct mbuf *n;
1379 
1380 			/*
1381 			 * XXX: give up if the whole (new) hbh header does
1382 			 * not fit even in an mbuf cluster.
1383 			 */
1384 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1385 				return (ENOBUFS);
1386 
1387 			/*
1388 			 * As a consequence, we must always prepare a cluster
1389 			 * at this point.
1390 			 */
1391 			n = m_getcl(M_NOWAIT, MT_DATA, 0);
1392 			if (n == NULL)
1393 				return (ENOBUFS);
1394 			n->m_len = oldoptlen + JUMBOOPTLEN;
1395 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1396 			    oldoptlen);
1397 			optbuf = mtod(n, caddr_t) + oldoptlen;
1398 			m_freem(mopt);
1399 			mopt = exthdrs->ip6e_hbh = n;
1400 		} else {
1401 			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1402 			mopt->m_len += JUMBOOPTLEN;
1403 		}
1404 		optbuf[0] = IP6OPT_PADN;
1405 		optbuf[1] = 1;
1406 
1407 		/*
1408 		 * Adjust the header length according to the pad and
1409 		 * the jumbo payload option.
1410 		 */
1411 		hbh = mtod(mopt, struct ip6_hbh *);
1412 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1413 	}
1414 
1415 	/* fill in the option. */
1416 	optbuf[2] = IP6OPT_JUMBO;
1417 	optbuf[3] = 4;
1418 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1419 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1420 
1421 	/* finally, adjust the packet header length */
1422 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1423 
1424 	return (0);
1425 #undef JUMBOOPTLEN
1426 }
1427 
1428 /*
1429  * Insert fragment header and copy unfragmentable header portions.
1430  */
1431 static int
ip6_insertfraghdr(struct mbuf * m0,struct mbuf * m,int hlen,struct ip6_frag ** frghdrp)1432 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1433     struct ip6_frag **frghdrp)
1434 {
1435 	struct mbuf *n, *mlast;
1436 
1437 	if (hlen > sizeof(struct ip6_hdr)) {
1438 		n = m_copym(m0, sizeof(struct ip6_hdr),
1439 		    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1440 		if (n == NULL)
1441 			return (ENOBUFS);
1442 		m->m_next = n;
1443 	} else
1444 		n = m;
1445 
1446 	/* Search for the last mbuf of unfragmentable part. */
1447 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1448 		;
1449 
1450 	if (M_WRITABLE(mlast) &&
1451 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1452 		/* use the trailing space of the last mbuf for the fragment hdr */
1453 		*frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1454 		    mlast->m_len);
1455 		mlast->m_len += sizeof(struct ip6_frag);
1456 		m->m_pkthdr.len += sizeof(struct ip6_frag);
1457 	} else {
1458 		/* allocate a new mbuf for the fragment header */
1459 		struct mbuf *mfrg;
1460 
1461 		mfrg = m_get(M_NOWAIT, MT_DATA);
1462 		if (mfrg == NULL)
1463 			return (ENOBUFS);
1464 		mfrg->m_len = sizeof(struct ip6_frag);
1465 		*frghdrp = mtod(mfrg, struct ip6_frag *);
1466 		mlast->m_next = mfrg;
1467 	}
1468 
1469 	return (0);
1470 }
1471 
1472 /*
1473  * Calculates IPv6 path mtu for destination @dst.
1474  * Resulting MTU is stored in @mtup.
1475  *
1476  * Returns 0 on success.
1477  */
1478 static int
ip6_getpmtu_ctl(u_int fibnum,const struct in6_addr * dst,u_long * mtup)1479 ip6_getpmtu_ctl(u_int fibnum, const struct in6_addr *dst, u_long *mtup)
1480 {
1481 	struct epoch_tracker et;
1482 	struct nhop_object *nh;
1483 	struct in6_addr kdst;
1484 	uint32_t scopeid;
1485 	int error;
1486 
1487 	in6_splitscope(dst, &kdst, &scopeid);
1488 
1489 	NET_EPOCH_ENTER(et);
1490 	nh = fib6_lookup(fibnum, &kdst, scopeid, NHR_NONE, 0);
1491 	if (nh != NULL)
1492 		error = ip6_calcmtu(nh->nh_ifp, dst, nh->nh_mtu, mtup, NULL, 0);
1493 	else
1494 		error = EHOSTUNREACH;
1495 	NET_EPOCH_EXIT(et);
1496 
1497 	return (error);
1498 }
1499 
1500 /*
1501  * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1502  * and cached data in @ro_pmtu.
1503  * MTU from (successful) route lookup is saved (along with dst)
1504  * inside @ro_pmtu to avoid subsequent route lookups after packet
1505  * filter processing.
1506  *
1507  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1508  * Returns 0 on success.
1509  */
1510 static int
ip6_getpmtu(struct route_in6 * ro_pmtu,int do_lookup,struct ifnet * ifp,const struct in6_addr * dst,u_long * mtup,int * alwaysfragp,u_int fibnum,u_int proto)1511 ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1512     struct ifnet *ifp, const struct in6_addr *dst, u_long *mtup,
1513     int *alwaysfragp, u_int fibnum, u_int proto)
1514 {
1515 	struct nhop_object *nh;
1516 	struct in6_addr kdst;
1517 	uint32_t scopeid;
1518 	struct sockaddr_in6 *sa6_dst, sin6;
1519 	u_long mtu;
1520 
1521 	NET_EPOCH_ASSERT();
1522 
1523 	mtu = 0;
1524 	if (ro_pmtu == NULL || do_lookup) {
1525 		/*
1526 		 * Here ro_pmtu has final destination address, while
1527 		 * ro might represent immediate destination.
1528 		 * Use ro_pmtu destination since mtu might differ.
1529 		 */
1530 		if (ro_pmtu != NULL) {
1531 			sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1532 			if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1533 				ro_pmtu->ro_mtu = 0;
1534 		} else
1535 			sa6_dst = &sin6;
1536 
1537 		if (ro_pmtu == NULL || ro_pmtu->ro_mtu == 0) {
1538 			bzero(sa6_dst, sizeof(*sa6_dst));
1539 			sa6_dst->sin6_family = AF_INET6;
1540 			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1541 			sa6_dst->sin6_addr = *dst;
1542 
1543 			in6_splitscope(dst, &kdst, &scopeid);
1544 			nh = fib6_lookup(fibnum, &kdst, scopeid, NHR_NONE, 0);
1545 			if (nh != NULL) {
1546 				mtu = nh->nh_mtu;
1547 				if (ro_pmtu != NULL)
1548 					ro_pmtu->ro_mtu = mtu;
1549 			}
1550 		} else
1551 			mtu = ro_pmtu->ro_mtu;
1552 	}
1553 
1554 	if (ro_pmtu != NULL && ro_pmtu->ro_nh != NULL)
1555 		mtu = ro_pmtu->ro_nh->nh_mtu;
1556 
1557 	return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp, proto));
1558 }
1559 
1560 /*
1561  * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1562  * hostcache data for @dst.
1563  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1564  *
1565  * Returns 0 on success.
1566  */
1567 static int
ip6_calcmtu(struct ifnet * ifp,const struct in6_addr * dst,u_long rt_mtu,u_long * mtup,int * alwaysfragp,u_int proto)1568 ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1569     u_long *mtup, int *alwaysfragp, u_int proto)
1570 {
1571 	u_long mtu = 0;
1572 	int alwaysfrag = 0;
1573 	int error = 0;
1574 
1575 	if (rt_mtu > 0) {
1576 		u_int32_t ifmtu;
1577 		struct in_conninfo inc;
1578 
1579 		bzero(&inc, sizeof(inc));
1580 		inc.inc_flags |= INC_ISIPV6;
1581 		inc.inc6_faddr = *dst;
1582 
1583 		ifmtu = IN6_LINKMTU(ifp);
1584 
1585 		/* TCP is known to react to pmtu changes so skip hc */
1586 		if (proto != IPPROTO_TCP)
1587 			mtu = tcp_hc_getmtu(&inc);
1588 
1589 		if (mtu)
1590 			mtu = min(mtu, rt_mtu);
1591 		else
1592 			mtu = rt_mtu;
1593 		if (mtu == 0)
1594 			mtu = ifmtu;
1595 		else if (mtu < IPV6_MMTU) {
1596 			/*
1597 			 * RFC2460 section 5, last paragraph:
1598 			 * if we record ICMPv6 too big message with
1599 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1600 			 * or smaller, with framgent header attached.
1601 			 * (fragment header is needed regardless from the
1602 			 * packet size, for translators to identify packets)
1603 			 */
1604 			alwaysfrag = 1;
1605 			mtu = IPV6_MMTU;
1606 		}
1607 	} else if (ifp) {
1608 		mtu = IN6_LINKMTU(ifp);
1609 	} else
1610 		error = EHOSTUNREACH; /* XXX */
1611 
1612 	*mtup = mtu;
1613 	if (alwaysfragp)
1614 		*alwaysfragp = alwaysfrag;
1615 	return (error);
1616 }
1617 
1618 /*
1619  * IP6 socket option processing.
1620  */
1621 int
ip6_ctloutput(struct socket * so,struct sockopt * sopt)1622 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1623 {
1624 	int optdatalen, uproto;
1625 	void *optdata;
1626 	struct inpcb *inp = sotoinpcb(so);
1627 	int error, optval;
1628 	int level, op, optname;
1629 	int optlen;
1630 	struct thread *td;
1631 #ifdef	RSS
1632 	uint32_t rss_bucket;
1633 	int retval;
1634 #endif
1635 
1636 /*
1637  * Don't use more than a quarter of mbuf clusters.  N.B.:
1638  * nmbclusters is an int, but nmbclusters * MCLBYTES may overflow
1639  * on LP64 architectures, so cast to u_long to avoid undefined
1640  * behavior.  ILP32 architectures cannot have nmbclusters
1641  * large enough to overflow for other reasons.
1642  */
1643 #define IPV6_PKTOPTIONS_MBUF_LIMIT	((u_long)nmbclusters * MCLBYTES / 4)
1644 
1645 	level = sopt->sopt_level;
1646 	op = sopt->sopt_dir;
1647 	optname = sopt->sopt_name;
1648 	optlen = sopt->sopt_valsize;
1649 	td = sopt->sopt_td;
1650 	error = 0;
1651 	optval = 0;
1652 	uproto = (int)so->so_proto->pr_protocol;
1653 
1654 	if (level != IPPROTO_IPV6) {
1655 		error = EINVAL;
1656 
1657 		if (sopt->sopt_level == SOL_SOCKET &&
1658 		    sopt->sopt_dir == SOPT_SET) {
1659 			switch (sopt->sopt_name) {
1660 			case SO_SETFIB:
1661 				error = sooptcopyin(sopt, &optval,
1662 				    sizeof(optval), sizeof(optval));
1663 				if (error != 0)
1664 					break;
1665 
1666 				INP_WLOCK(inp);
1667 				if ((inp->inp_flags & INP_BOUNDFIB) != 0 &&
1668 				    optval != so->so_fibnum) {
1669 					INP_WUNLOCK(inp);
1670 					error = EISCONN;
1671 					break;
1672 				}
1673 				error = sosetfib(inp->inp_socket, optval);
1674 				if (error == 0)
1675 					inp->inp_inc.inc_fibnum = optval;
1676 				INP_WUNLOCK(inp);
1677 				break;
1678 			case SO_MAX_PACING_RATE:
1679 #ifdef RATELIMIT
1680 				INP_WLOCK(inp);
1681 				inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1682 				INP_WUNLOCK(inp);
1683 				error = 0;
1684 #else
1685 				error = EOPNOTSUPP;
1686 #endif
1687 				break;
1688 			default:
1689 				break;
1690 			}
1691 		}
1692 	} else {		/* level == IPPROTO_IPV6 */
1693 		switch (op) {
1694 		case SOPT_SET:
1695 			switch (optname) {
1696 			case IPV6_2292PKTOPTIONS:
1697 #ifdef IPV6_PKTOPTIONS
1698 			case IPV6_PKTOPTIONS:
1699 #endif
1700 			{
1701 				struct mbuf *m;
1702 
1703 				if (optlen > IPV6_PKTOPTIONS_MBUF_LIMIT) {
1704 					printf("ip6_ctloutput: mbuf limit hit\n");
1705 					error = ENOBUFS;
1706 					break;
1707 				}
1708 
1709 				error = soopt_getm(sopt, &m); /* XXX */
1710 				if (error != 0)
1711 					break;
1712 				error = soopt_mcopyin(sopt, m); /* XXX */
1713 				if (error != 0)
1714 					break;
1715 				INP_WLOCK(inp);
1716 				error = ip6_pcbopts(&inp->in6p_outputopts, m,
1717 				    so, sopt);
1718 				INP_WUNLOCK(inp);
1719 				m_freem(m); /* XXX */
1720 				break;
1721 			}
1722 
1723 			/*
1724 			 * Use of some Hop-by-Hop options or some
1725 			 * Destination options, might require special
1726 			 * privilege.  That is, normal applications
1727 			 * (without special privilege) might be forbidden
1728 			 * from setting certain options in outgoing packets,
1729 			 * and might never see certain options in received
1730 			 * packets. [RFC 2292 Section 6]
1731 			 * KAME specific note:
1732 			 *  KAME prevents non-privileged users from sending or
1733 			 *  receiving ANY hbh/dst options in order to avoid
1734 			 *  overhead of parsing options in the kernel.
1735 			 */
1736 			case IPV6_RECVHOPOPTS:
1737 			case IPV6_RECVDSTOPTS:
1738 			case IPV6_RECVRTHDRDSTOPTS:
1739 				if (td != NULL) {
1740 					error = priv_check(td,
1741 					    PRIV_NETINET_SETHDROPTS);
1742 					if (error)
1743 						break;
1744 				}
1745 				/* FALLTHROUGH */
1746 			case IPV6_UNICAST_HOPS:
1747 			case IPV6_HOPLIMIT:
1748 
1749 			case IPV6_RECVPKTINFO:
1750 			case IPV6_RECVHOPLIMIT:
1751 			case IPV6_RECVRTHDR:
1752 			case IPV6_RECVPATHMTU:
1753 			case IPV6_RECVTCLASS:
1754 			case IPV6_RECVFLOWID:
1755 #ifdef	RSS
1756 			case IPV6_RECVRSSBUCKETID:
1757 #endif
1758 			case IPV6_V6ONLY:
1759 			case IPV6_AUTOFLOWLABEL:
1760 			case IPV6_ORIGDSTADDR:
1761 			case IPV6_BINDANY:
1762 			case IPV6_VLAN_PCP:
1763 				if (optname == IPV6_BINDANY && td != NULL) {
1764 					error = priv_check(td,
1765 					    PRIV_NETINET_BINDANY);
1766 					if (error)
1767 						break;
1768 				}
1769 
1770 				if (optlen != sizeof(int)) {
1771 					error = EINVAL;
1772 					break;
1773 				}
1774 				error = sooptcopyin(sopt, &optval,
1775 					sizeof optval, sizeof optval);
1776 				if (error)
1777 					break;
1778 				switch (optname) {
1779 				case IPV6_UNICAST_HOPS:
1780 					if (optval < -1 || optval >= 256)
1781 						error = EINVAL;
1782 					else {
1783 						/* -1 = kernel default */
1784 						inp->in6p_hops = optval;
1785 						if ((inp->inp_vflag &
1786 						     INP_IPV4) != 0)
1787 							inp->inp_ip_ttl = optval;
1788 					}
1789 					break;
1790 #define OPTSET(bit) \
1791 do { \
1792 	INP_WLOCK(inp); \
1793 	if (optval) \
1794 		inp->inp_flags |= (bit); \
1795 	else \
1796 		inp->inp_flags &= ~(bit); \
1797 	INP_WUNLOCK(inp); \
1798 } while (/*CONSTCOND*/ 0)
1799 #define OPTSET2292(bit) \
1800 do { \
1801 	INP_WLOCK(inp); \
1802 	inp->inp_flags |= IN6P_RFC2292; \
1803 	if (optval) \
1804 		inp->inp_flags |= (bit); \
1805 	else \
1806 		inp->inp_flags &= ~(bit); \
1807 	INP_WUNLOCK(inp); \
1808 } while (/*CONSTCOND*/ 0)
1809 #define OPTBIT(bit) (inp->inp_flags & (bit) ? 1 : 0)
1810 
1811 #define OPTSET2_N(bit, val) do {					\
1812 	if (val)							\
1813 		inp->inp_flags2 |= bit;					\
1814 	else								\
1815 		inp->inp_flags2 &= ~bit;				\
1816 } while (0)
1817 #define OPTSET2(bit, val) do {						\
1818 	INP_WLOCK(inp);							\
1819 	OPTSET2_N(bit, val);						\
1820 	INP_WUNLOCK(inp);						\
1821 } while (0)
1822 #define OPTBIT2(bit) (inp->inp_flags2 & (bit) ? 1 : 0)
1823 #define OPTSET2292_EXCLUSIVE(bit)					\
1824 do {									\
1825 	INP_WLOCK(inp);							\
1826 	if (OPTBIT(IN6P_RFC2292)) {					\
1827 		error = EINVAL;						\
1828 	} else {							\
1829 		if (optval)						\
1830 			inp->inp_flags |= (bit);			\
1831 		else							\
1832 			inp->inp_flags &= ~(bit);			\
1833 	}								\
1834 	INP_WUNLOCK(inp);						\
1835 } while (/*CONSTCOND*/ 0)
1836 
1837 				case IPV6_RECVPKTINFO:
1838 					OPTSET2292_EXCLUSIVE(IN6P_PKTINFO);
1839 					break;
1840 
1841 				case IPV6_HOPLIMIT:
1842 				{
1843 					struct ip6_pktopts **optp;
1844 
1845 					/* cannot mix with RFC2292 */
1846 					if (OPTBIT(IN6P_RFC2292)) {
1847 						error = EINVAL;
1848 						break;
1849 					}
1850 					INP_WLOCK(inp);
1851 					if (inp->inp_flags & INP_DROPPED) {
1852 						INP_WUNLOCK(inp);
1853 						return (ECONNRESET);
1854 					}
1855 					optp = &inp->in6p_outputopts;
1856 					error = ip6_pcbopt(IPV6_HOPLIMIT,
1857 					    (u_char *)&optval, sizeof(optval),
1858 					    optp, (td != NULL) ? td->td_ucred :
1859 					    NULL, uproto);
1860 					INP_WUNLOCK(inp);
1861 					break;
1862 				}
1863 
1864 				case IPV6_RECVHOPLIMIT:
1865 					OPTSET2292_EXCLUSIVE(IN6P_HOPLIMIT);
1866 					break;
1867 
1868 				case IPV6_RECVHOPOPTS:
1869 					OPTSET2292_EXCLUSIVE(IN6P_HOPOPTS);
1870 					break;
1871 
1872 				case IPV6_RECVDSTOPTS:
1873 					OPTSET2292_EXCLUSIVE(IN6P_DSTOPTS);
1874 					break;
1875 
1876 				case IPV6_RECVRTHDRDSTOPTS:
1877 					OPTSET2292_EXCLUSIVE(IN6P_RTHDRDSTOPTS);
1878 					break;
1879 
1880 				case IPV6_RECVRTHDR:
1881 					OPTSET2292_EXCLUSIVE(IN6P_RTHDR);
1882 					break;
1883 
1884 				case IPV6_RECVPATHMTU:
1885 					/*
1886 					 * We ignore this option for TCP
1887 					 * sockets.
1888 					 * (RFC3542 leaves this case
1889 					 * unspecified.)
1890 					 */
1891 					if (uproto != IPPROTO_TCP)
1892 						OPTSET(IN6P_MTU);
1893 					break;
1894 
1895 				case IPV6_RECVFLOWID:
1896 					OPTSET2(INP_RECVFLOWID, optval);
1897 					break;
1898 
1899 #ifdef	RSS
1900 				case IPV6_RECVRSSBUCKETID:
1901 					OPTSET2(INP_RECVRSSBUCKETID, optval);
1902 					break;
1903 #endif
1904 
1905 				case IPV6_V6ONLY:
1906 					INP_WLOCK(inp);
1907 					if (inp->inp_lport ||
1908 					    !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
1909 						/*
1910 						 * The socket is already bound.
1911 						 */
1912 						INP_WUNLOCK(inp);
1913 						error = EINVAL;
1914 						break;
1915 					}
1916 					if (optval) {
1917 						inp->inp_flags |= IN6P_IPV6_V6ONLY;
1918 						inp->inp_vflag &= ~INP_IPV4;
1919 					} else {
1920 						inp->inp_flags &= ~IN6P_IPV6_V6ONLY;
1921 						inp->inp_vflag |= INP_IPV4;
1922 					}
1923 					INP_WUNLOCK(inp);
1924 					break;
1925 				case IPV6_RECVTCLASS:
1926 					/* cannot mix with RFC2292 XXX */
1927 					OPTSET2292_EXCLUSIVE(IN6P_TCLASS);
1928 					break;
1929 				case IPV6_AUTOFLOWLABEL:
1930 					OPTSET(IN6P_AUTOFLOWLABEL);
1931 					break;
1932 
1933 				case IPV6_ORIGDSTADDR:
1934 					OPTSET2(INP_ORIGDSTADDR, optval);
1935 					break;
1936 				case IPV6_BINDANY:
1937 					OPTSET(INP_BINDANY);
1938 					break;
1939 				case IPV6_VLAN_PCP:
1940 					if ((optval >= -1) && (optval <=
1941 					    (INP_2PCP_MASK >> INP_2PCP_SHIFT))) {
1942 						if (optval == -1) {
1943 							INP_WLOCK(inp);
1944 							inp->inp_flags2 &=
1945 							    ~(INP_2PCP_SET |
1946 							    INP_2PCP_MASK);
1947 							INP_WUNLOCK(inp);
1948 						} else {
1949 							INP_WLOCK(inp);
1950 							inp->inp_flags2 |=
1951 							    INP_2PCP_SET;
1952 							inp->inp_flags2 &=
1953 							    ~INP_2PCP_MASK;
1954 							inp->inp_flags2 |=
1955 							    optval <<
1956 							    INP_2PCP_SHIFT;
1957 							INP_WUNLOCK(inp);
1958 						}
1959 					} else
1960 						error = EINVAL;
1961 					break;
1962 				}
1963 				break;
1964 
1965 			case IPV6_TCLASS:
1966 			case IPV6_DONTFRAG:
1967 			case IPV6_USE_MIN_MTU:
1968 			case IPV6_PREFER_TEMPADDR:
1969 				if (optlen != sizeof(optval)) {
1970 					error = EINVAL;
1971 					break;
1972 				}
1973 				error = sooptcopyin(sopt, &optval,
1974 					sizeof optval, sizeof optval);
1975 				if (error)
1976 					break;
1977 				{
1978 					struct ip6_pktopts **optp;
1979 					INP_WLOCK(inp);
1980 					if (inp->inp_flags & INP_DROPPED) {
1981 						INP_WUNLOCK(inp);
1982 						return (ECONNRESET);
1983 					}
1984 					optp = &inp->in6p_outputopts;
1985 					error = ip6_pcbopt(optname,
1986 					    (u_char *)&optval, sizeof(optval),
1987 					    optp, (td != NULL) ? td->td_ucred :
1988 					    NULL, uproto);
1989 					INP_WUNLOCK(inp);
1990 					break;
1991 				}
1992 
1993 			case IPV6_2292PKTINFO:
1994 			case IPV6_2292HOPLIMIT:
1995 			case IPV6_2292HOPOPTS:
1996 			case IPV6_2292DSTOPTS:
1997 			case IPV6_2292RTHDR:
1998 				/* RFC 2292 */
1999 				if (optlen != sizeof(int)) {
2000 					error = EINVAL;
2001 					break;
2002 				}
2003 				error = sooptcopyin(sopt, &optval,
2004 					sizeof optval, sizeof optval);
2005 				if (error)
2006 					break;
2007 				switch (optname) {
2008 				case IPV6_2292PKTINFO:
2009 					OPTSET2292(IN6P_PKTINFO);
2010 					break;
2011 				case IPV6_2292HOPLIMIT:
2012 					OPTSET2292(IN6P_HOPLIMIT);
2013 					break;
2014 				case IPV6_2292HOPOPTS:
2015 					/*
2016 					 * Check super-user privilege.
2017 					 * See comments for IPV6_RECVHOPOPTS.
2018 					 */
2019 					if (td != NULL) {
2020 						error = priv_check(td,
2021 						    PRIV_NETINET_SETHDROPTS);
2022 						if (error)
2023 							return (error);
2024 					}
2025 					OPTSET2292(IN6P_HOPOPTS);
2026 					break;
2027 				case IPV6_2292DSTOPTS:
2028 					if (td != NULL) {
2029 						error = priv_check(td,
2030 						    PRIV_NETINET_SETHDROPTS);
2031 						if (error)
2032 							return (error);
2033 					}
2034 					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
2035 					break;
2036 				case IPV6_2292RTHDR:
2037 					OPTSET2292(IN6P_RTHDR);
2038 					break;
2039 				}
2040 				break;
2041 			case IPV6_PKTINFO:
2042 			case IPV6_HOPOPTS:
2043 			case IPV6_RTHDR:
2044 			case IPV6_DSTOPTS:
2045 			case IPV6_RTHDRDSTOPTS:
2046 			case IPV6_NEXTHOP:
2047 			{
2048 				/* new advanced API (RFC3542) */
2049 				u_char *optbuf;
2050 				u_char optbuf_storage[MCLBYTES];
2051 				int optlen;
2052 				struct ip6_pktopts **optp;
2053 
2054 				/* cannot mix with RFC2292 */
2055 				if (OPTBIT(IN6P_RFC2292)) {
2056 					error = EINVAL;
2057 					break;
2058 				}
2059 
2060 				/*
2061 				 * We only ensure valsize is not too large
2062 				 * here.  Further validation will be done
2063 				 * later.
2064 				 */
2065 				error = sooptcopyin(sopt, optbuf_storage,
2066 				    sizeof(optbuf_storage), 0);
2067 				if (error)
2068 					break;
2069 				optlen = sopt->sopt_valsize;
2070 				optbuf = optbuf_storage;
2071 				INP_WLOCK(inp);
2072 				if (inp->inp_flags & INP_DROPPED) {
2073 					INP_WUNLOCK(inp);
2074 					return (ECONNRESET);
2075 				}
2076 				optp = &inp->in6p_outputopts;
2077 				error = ip6_pcbopt(optname, optbuf, optlen,
2078 				    optp, (td != NULL) ? td->td_ucred : NULL,
2079 				    uproto);
2080 				INP_WUNLOCK(inp);
2081 				break;
2082 			}
2083 #undef OPTSET
2084 
2085 			case IPV6_MULTICAST_IF:
2086 			case IPV6_MULTICAST_HOPS:
2087 			case IPV6_MULTICAST_LOOP:
2088 			case IPV6_JOIN_GROUP:
2089 			case IPV6_LEAVE_GROUP:
2090 			case IPV6_MSFILTER:
2091 			case MCAST_BLOCK_SOURCE:
2092 			case MCAST_UNBLOCK_SOURCE:
2093 			case MCAST_JOIN_GROUP:
2094 			case MCAST_LEAVE_GROUP:
2095 			case MCAST_JOIN_SOURCE_GROUP:
2096 			case MCAST_LEAVE_SOURCE_GROUP:
2097 				error = ip6_setmoptions(inp, sopt);
2098 				break;
2099 
2100 			case IPV6_PORTRANGE:
2101 				error = sooptcopyin(sopt, &optval,
2102 				    sizeof optval, sizeof optval);
2103 				if (error)
2104 					break;
2105 
2106 				INP_WLOCK(inp);
2107 				switch (optval) {
2108 				case IPV6_PORTRANGE_DEFAULT:
2109 					inp->inp_flags &= ~(INP_LOWPORT);
2110 					inp->inp_flags &= ~(INP_HIGHPORT);
2111 					break;
2112 
2113 				case IPV6_PORTRANGE_HIGH:
2114 					inp->inp_flags &= ~(INP_LOWPORT);
2115 					inp->inp_flags |= INP_HIGHPORT;
2116 					break;
2117 
2118 				case IPV6_PORTRANGE_LOW:
2119 					inp->inp_flags &= ~(INP_HIGHPORT);
2120 					inp->inp_flags |= INP_LOWPORT;
2121 					break;
2122 
2123 				default:
2124 					error = EINVAL;
2125 					break;
2126 				}
2127 				INP_WUNLOCK(inp);
2128 				break;
2129 
2130 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
2131 			case IPV6_IPSEC_POLICY:
2132 				if (IPSEC_ENABLED(ipv6)) {
2133 					error = IPSEC_PCBCTL(ipv6, inp, sopt);
2134 					break;
2135 				}
2136 				/* FALLTHROUGH */
2137 #endif /* IPSEC */
2138 
2139 			default:
2140 				error = ENOPROTOOPT;
2141 				break;
2142 			}
2143 			break;
2144 
2145 		case SOPT_GET:
2146 			switch (optname) {
2147 			case IPV6_2292PKTOPTIONS:
2148 #ifdef IPV6_PKTOPTIONS
2149 			case IPV6_PKTOPTIONS:
2150 #endif
2151 				/*
2152 				 * RFC3542 (effectively) deprecated the
2153 				 * semantics of the 2292-style pktoptions.
2154 				 * Since it was not reliable in nature (i.e.,
2155 				 * applications had to expect the lack of some
2156 				 * information after all), it would make sense
2157 				 * to simplify this part by always returning
2158 				 * empty data.
2159 				 */
2160 				sopt->sopt_valsize = 0;
2161 				break;
2162 
2163 			case IPV6_RECVHOPOPTS:
2164 			case IPV6_RECVDSTOPTS:
2165 			case IPV6_RECVRTHDRDSTOPTS:
2166 			case IPV6_UNICAST_HOPS:
2167 			case IPV6_RECVPKTINFO:
2168 			case IPV6_RECVHOPLIMIT:
2169 			case IPV6_RECVRTHDR:
2170 			case IPV6_RECVPATHMTU:
2171 
2172 			case IPV6_V6ONLY:
2173 			case IPV6_PORTRANGE:
2174 			case IPV6_RECVTCLASS:
2175 			case IPV6_AUTOFLOWLABEL:
2176 			case IPV6_BINDANY:
2177 			case IPV6_FLOWID:
2178 			case IPV6_FLOWTYPE:
2179 			case IPV6_RECVFLOWID:
2180 #ifdef	RSS
2181 			case IPV6_RSSBUCKETID:
2182 			case IPV6_RECVRSSBUCKETID:
2183 #endif
2184 			case IPV6_VLAN_PCP:
2185 				switch (optname) {
2186 				case IPV6_RECVHOPOPTS:
2187 					optval = OPTBIT(IN6P_HOPOPTS);
2188 					break;
2189 
2190 				case IPV6_RECVDSTOPTS:
2191 					optval = OPTBIT(IN6P_DSTOPTS);
2192 					break;
2193 
2194 				case IPV6_RECVRTHDRDSTOPTS:
2195 					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
2196 					break;
2197 
2198 				case IPV6_UNICAST_HOPS:
2199 					optval = inp->in6p_hops;
2200 					break;
2201 
2202 				case IPV6_RECVPKTINFO:
2203 					optval = OPTBIT(IN6P_PKTINFO);
2204 					break;
2205 
2206 				case IPV6_RECVHOPLIMIT:
2207 					optval = OPTBIT(IN6P_HOPLIMIT);
2208 					break;
2209 
2210 				case IPV6_RECVRTHDR:
2211 					optval = OPTBIT(IN6P_RTHDR);
2212 					break;
2213 
2214 				case IPV6_RECVPATHMTU:
2215 					optval = OPTBIT(IN6P_MTU);
2216 					break;
2217 
2218 				case IPV6_V6ONLY:
2219 					optval = OPTBIT(IN6P_IPV6_V6ONLY);
2220 					break;
2221 
2222 				case IPV6_PORTRANGE:
2223 				    {
2224 					int flags;
2225 					flags = inp->inp_flags;
2226 					if (flags & INP_HIGHPORT)
2227 						optval = IPV6_PORTRANGE_HIGH;
2228 					else if (flags & INP_LOWPORT)
2229 						optval = IPV6_PORTRANGE_LOW;
2230 					else
2231 						optval = 0;
2232 					break;
2233 				    }
2234 				case IPV6_RECVTCLASS:
2235 					optval = OPTBIT(IN6P_TCLASS);
2236 					break;
2237 
2238 				case IPV6_AUTOFLOWLABEL:
2239 					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2240 					break;
2241 
2242 				case IPV6_ORIGDSTADDR:
2243 					optval = OPTBIT2(INP_ORIGDSTADDR);
2244 					break;
2245 
2246 				case IPV6_BINDANY:
2247 					optval = OPTBIT(INP_BINDANY);
2248 					break;
2249 
2250 				case IPV6_FLOWID:
2251 					optval = inp->inp_flowid;
2252 					break;
2253 
2254 				case IPV6_FLOWTYPE:
2255 					optval = inp->inp_flowtype;
2256 					break;
2257 
2258 				case IPV6_RECVFLOWID:
2259 					optval = OPTBIT2(INP_RECVFLOWID);
2260 					break;
2261 #ifdef	RSS
2262 				case IPV6_RSSBUCKETID:
2263 					retval =
2264 					    rss_hash2bucket(inp->inp_flowid,
2265 					    inp->inp_flowtype,
2266 					    &rss_bucket);
2267 					if (retval == 0)
2268 						optval = rss_bucket;
2269 					else
2270 						error = EINVAL;
2271 					break;
2272 
2273 				case IPV6_RECVRSSBUCKETID:
2274 					optval = OPTBIT2(INP_RECVRSSBUCKETID);
2275 					break;
2276 #endif
2277 
2278 
2279 				case IPV6_VLAN_PCP:
2280 					if (OPTBIT2(INP_2PCP_SET)) {
2281 						optval = (inp->inp_flags2 &
2282 							    INP_2PCP_MASK) >>
2283 							    INP_2PCP_SHIFT;
2284 					} else {
2285 						optval = -1;
2286 					}
2287 					break;
2288 				}
2289 
2290 				if (error)
2291 					break;
2292 				error = sooptcopyout(sopt, &optval,
2293 					sizeof optval);
2294 				break;
2295 
2296 			case IPV6_PATHMTU:
2297 			{
2298 				u_long pmtu = 0;
2299 				struct ip6_mtuinfo mtuinfo;
2300 				struct in6_addr addr;
2301 
2302 				if (!(so->so_state & SS_ISCONNECTED))
2303 					return (ENOTCONN);
2304 				/*
2305 				 * XXX: we dot not consider the case of source
2306 				 * routing, or optional information to specify
2307 				 * the outgoing interface.
2308 				 * Copy faddr out of inp to avoid holding lock
2309 				 * on inp during route lookup.
2310 				 */
2311 				INP_RLOCK(inp);
2312 				bcopy(&inp->in6p_faddr, &addr, sizeof(addr));
2313 				INP_RUNLOCK(inp);
2314 				error = ip6_getpmtu_ctl(so->so_fibnum,
2315 				    &addr, &pmtu);
2316 				if (error)
2317 					break;
2318 				if (pmtu > IPV6_MAXPACKET)
2319 					pmtu = IPV6_MAXPACKET;
2320 
2321 				bzero(&mtuinfo, sizeof(mtuinfo));
2322 				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2323 				optdata = (void *)&mtuinfo;
2324 				optdatalen = sizeof(mtuinfo);
2325 				error = sooptcopyout(sopt, optdata,
2326 				    optdatalen);
2327 				break;
2328 			}
2329 
2330 			case IPV6_2292PKTINFO:
2331 			case IPV6_2292HOPLIMIT:
2332 			case IPV6_2292HOPOPTS:
2333 			case IPV6_2292RTHDR:
2334 			case IPV6_2292DSTOPTS:
2335 				switch (optname) {
2336 				case IPV6_2292PKTINFO:
2337 					optval = OPTBIT(IN6P_PKTINFO);
2338 					break;
2339 				case IPV6_2292HOPLIMIT:
2340 					optval = OPTBIT(IN6P_HOPLIMIT);
2341 					break;
2342 				case IPV6_2292HOPOPTS:
2343 					optval = OPTBIT(IN6P_HOPOPTS);
2344 					break;
2345 				case IPV6_2292RTHDR:
2346 					optval = OPTBIT(IN6P_RTHDR);
2347 					break;
2348 				case IPV6_2292DSTOPTS:
2349 					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2350 					break;
2351 				}
2352 				error = sooptcopyout(sopt, &optval,
2353 				    sizeof optval);
2354 				break;
2355 			case IPV6_PKTINFO:
2356 			case IPV6_HOPOPTS:
2357 			case IPV6_RTHDR:
2358 			case IPV6_DSTOPTS:
2359 			case IPV6_RTHDRDSTOPTS:
2360 			case IPV6_NEXTHOP:
2361 			case IPV6_TCLASS:
2362 			case IPV6_DONTFRAG:
2363 			case IPV6_USE_MIN_MTU:
2364 			case IPV6_PREFER_TEMPADDR:
2365 				error = ip6_getpcbopt(inp, optname, sopt);
2366 				break;
2367 
2368 			case IPV6_MULTICAST_IF:
2369 			case IPV6_MULTICAST_HOPS:
2370 			case IPV6_MULTICAST_LOOP:
2371 			case IPV6_MSFILTER:
2372 				error = ip6_getmoptions(inp, sopt);
2373 				break;
2374 
2375 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
2376 			case IPV6_IPSEC_POLICY:
2377 				if (IPSEC_ENABLED(ipv6)) {
2378 					error = IPSEC_PCBCTL(ipv6, inp, sopt);
2379 					break;
2380 				}
2381 				/* FALLTHROUGH */
2382 #endif /* IPSEC */
2383 			default:
2384 				error = ENOPROTOOPT;
2385 				break;
2386 			}
2387 			break;
2388 		}
2389 	}
2390 	return (error);
2391 }
2392 
2393 int
ip6_raw_ctloutput(struct socket * so,struct sockopt * sopt)2394 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2395 {
2396 	int error = 0, optval, optlen;
2397 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2398 	struct inpcb *inp = sotoinpcb(so);
2399 	int level, op, optname;
2400 
2401 	level = sopt->sopt_level;
2402 	op = sopt->sopt_dir;
2403 	optname = sopt->sopt_name;
2404 	optlen = sopt->sopt_valsize;
2405 
2406 	if (level != IPPROTO_IPV6) {
2407 		return (EINVAL);
2408 	}
2409 
2410 	switch (optname) {
2411 	case IPV6_CHECKSUM:
2412 		/*
2413 		 * For ICMPv6 sockets, no modification allowed for checksum
2414 		 * offset, permit "no change" values to help existing apps.
2415 		 *
2416 		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2417 		 * for an ICMPv6 socket will fail."
2418 		 * The current behavior does not meet RFC3542.
2419 		 */
2420 		switch (op) {
2421 		case SOPT_SET:
2422 			if (optlen != sizeof(int)) {
2423 				error = EINVAL;
2424 				break;
2425 			}
2426 			error = sooptcopyin(sopt, &optval, sizeof(optval),
2427 					    sizeof(optval));
2428 			if (error)
2429 				break;
2430 			if (optval < -1 || (optval % 2) != 0) {
2431 				/*
2432 				 * The API assumes non-negative even offset
2433 				 * values or -1 as a special value.
2434 				 */
2435 				error = EINVAL;
2436 			} else if (inp->inp_ip_p == IPPROTO_ICMPV6) {
2437 				if (optval != icmp6off)
2438 					error = EINVAL;
2439 			} else
2440 				inp->in6p_cksum = optval;
2441 			break;
2442 
2443 		case SOPT_GET:
2444 			if (inp->inp_ip_p == IPPROTO_ICMPV6)
2445 				optval = icmp6off;
2446 			else
2447 				optval = inp->in6p_cksum;
2448 
2449 			error = sooptcopyout(sopt, &optval, sizeof(optval));
2450 			break;
2451 
2452 		default:
2453 			error = EINVAL;
2454 			break;
2455 		}
2456 		break;
2457 
2458 	default:
2459 		error = ENOPROTOOPT;
2460 		break;
2461 	}
2462 
2463 	return (error);
2464 }
2465 
2466 /*
2467  * Set up IP6 options in pcb for insertion in output packets or
2468  * specifying behavior of outgoing packets.
2469  */
2470 static int
ip6_pcbopts(struct ip6_pktopts ** pktopt,struct mbuf * m,struct socket * so,struct sockopt * sopt)2471 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2472     struct socket *so, struct sockopt *sopt)
2473 {
2474 	struct ip6_pktopts *opt = *pktopt;
2475 	int error = 0;
2476 	struct thread *td = sopt->sopt_td;
2477 	struct epoch_tracker et;
2478 
2479 	/* turn off any old options. */
2480 	if (opt) {
2481 #ifdef DIAGNOSTIC
2482 		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2483 		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2484 		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2485 			printf("ip6_pcbopts: all specified options are cleared.\n");
2486 #endif
2487 		ip6_clearpktopts(opt, -1);
2488 	} else {
2489 		opt = malloc(sizeof(*opt), M_IP6OPT, M_NOWAIT);
2490 		if (opt == NULL)
2491 			return (ENOMEM);
2492 	}
2493 	*pktopt = NULL;
2494 
2495 	if (!m || m->m_len == 0) {
2496 		/*
2497 		 * Only turning off any previous options, regardless of
2498 		 * whether the opt is just created or given.
2499 		 */
2500 		free(opt, M_IP6OPT);
2501 		return (0);
2502 	}
2503 
2504 	/*  set options specified by user. */
2505 	NET_EPOCH_ENTER(et);
2506 	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2507 	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2508 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2509 		free(opt, M_IP6OPT);
2510 		NET_EPOCH_EXIT(et);
2511 		return (error);
2512 	}
2513 	NET_EPOCH_EXIT(et);
2514 	*pktopt = opt;
2515 	return (0);
2516 }
2517 
2518 /*
2519  * initialize ip6_pktopts.  beware that there are non-zero default values in
2520  * the struct.
2521  */
2522 void
ip6_initpktopts(struct ip6_pktopts * opt)2523 ip6_initpktopts(struct ip6_pktopts *opt)
2524 {
2525 
2526 	bzero(opt, sizeof(*opt));
2527 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2528 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2529 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2530 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2531 }
2532 
2533 static int
ip6_pcbopt(int optname,u_char * buf,int len,struct ip6_pktopts ** pktopt,struct ucred * cred,int uproto)2534 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2535     struct ucred *cred, int uproto)
2536 {
2537 	struct epoch_tracker et;
2538 	struct ip6_pktopts *opt;
2539 	int ret;
2540 
2541 	if (*pktopt == NULL) {
2542 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2543 		    M_NOWAIT);
2544 		if (*pktopt == NULL)
2545 			return (ENOBUFS);
2546 		ip6_initpktopts(*pktopt);
2547 	}
2548 	opt = *pktopt;
2549 
2550 	NET_EPOCH_ENTER(et);
2551 	ret = ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto);
2552 	NET_EPOCH_EXIT(et);
2553 
2554 	return (ret);
2555 }
2556 
2557 #define GET_PKTOPT_VAR(field, lenexpr) do {				\
2558 	if (pktopt && pktopt->field) {					\
2559 		INP_RUNLOCK(inp);					\
2560 		optdata = malloc(sopt->sopt_valsize, M_TEMP, M_WAITOK);	\
2561 		malloc_optdata = true;					\
2562 		INP_RLOCK(inp);						\
2563 		if (inp->inp_flags & INP_DROPPED) {			\
2564 			INP_RUNLOCK(inp);				\
2565 			free(optdata, M_TEMP);				\
2566 			return (ECONNRESET);				\
2567 		}							\
2568 		pktopt = inp->in6p_outputopts;				\
2569 		if (pktopt && pktopt->field) {				\
2570 			optdatalen = min(lenexpr, sopt->sopt_valsize);	\
2571 			bcopy(pktopt->field, optdata, optdatalen);	\
2572 		} else {						\
2573 			free(optdata, M_TEMP);				\
2574 			optdata = NULL;					\
2575 			malloc_optdata = false;				\
2576 		}							\
2577 	}								\
2578 } while(0)
2579 
2580 #define GET_PKTOPT_EXT_HDR(field) GET_PKTOPT_VAR(field,			\
2581 	(((struct ip6_ext *)pktopt->field)->ip6e_len + 1) << 3)
2582 
2583 #define GET_PKTOPT_SOCKADDR(field) GET_PKTOPT_VAR(field,		\
2584 	pktopt->field->sa_len)
2585 
2586 static int
ip6_getpcbopt(struct inpcb * inp,int optname,struct sockopt * sopt)2587 ip6_getpcbopt(struct inpcb *inp, int optname, struct sockopt *sopt)
2588 {
2589 	void *optdata = NULL;
2590 	bool malloc_optdata = false;
2591 	int optdatalen = 0;
2592 	int error = 0;
2593 	struct in6_pktinfo null_pktinfo;
2594 	int deftclass = 0, on;
2595 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2596 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2597 	struct ip6_pktopts *pktopt;
2598 
2599 	INP_RLOCK(inp);
2600 	pktopt = inp->in6p_outputopts;
2601 
2602 	switch (optname) {
2603 	case IPV6_PKTINFO:
2604 		optdata = (void *)&null_pktinfo;
2605 		if (pktopt && pktopt->ip6po_pktinfo) {
2606 			bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2607 			    sizeof(null_pktinfo));
2608 			in6_clearscope(&null_pktinfo.ipi6_addr);
2609 		} else {
2610 			/* XXX: we don't have to do this every time... */
2611 			bzero(&null_pktinfo, sizeof(null_pktinfo));
2612 		}
2613 		optdatalen = sizeof(struct in6_pktinfo);
2614 		break;
2615 	case IPV6_TCLASS:
2616 		if (pktopt && pktopt->ip6po_tclass >= 0)
2617 			deftclass = pktopt->ip6po_tclass;
2618 		optdata = (void *)&deftclass;
2619 		optdatalen = sizeof(int);
2620 		break;
2621 	case IPV6_HOPOPTS:
2622 		GET_PKTOPT_EXT_HDR(ip6po_hbh);
2623 		break;
2624 	case IPV6_RTHDR:
2625 		GET_PKTOPT_EXT_HDR(ip6po_rthdr);
2626 		break;
2627 	case IPV6_RTHDRDSTOPTS:
2628 		GET_PKTOPT_EXT_HDR(ip6po_dest1);
2629 		break;
2630 	case IPV6_DSTOPTS:
2631 		GET_PKTOPT_EXT_HDR(ip6po_dest2);
2632 		break;
2633 	case IPV6_NEXTHOP:
2634 		GET_PKTOPT_SOCKADDR(ip6po_nexthop);
2635 		break;
2636 	case IPV6_USE_MIN_MTU:
2637 		if (pktopt)
2638 			defminmtu = pktopt->ip6po_minmtu;
2639 		optdata = (void *)&defminmtu;
2640 		optdatalen = sizeof(int);
2641 		break;
2642 	case IPV6_DONTFRAG:
2643 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2644 			on = 1;
2645 		else
2646 			on = 0;
2647 		optdata = (void *)&on;
2648 		optdatalen = sizeof(on);
2649 		break;
2650 	case IPV6_PREFER_TEMPADDR:
2651 		if (pktopt)
2652 			defpreftemp = pktopt->ip6po_prefer_tempaddr;
2653 		optdata = (void *)&defpreftemp;
2654 		optdatalen = sizeof(int);
2655 		break;
2656 	default:		/* should not happen */
2657 #ifdef DIAGNOSTIC
2658 		panic("ip6_getpcbopt: unexpected option\n");
2659 #endif
2660 		INP_RUNLOCK(inp);
2661 		return (ENOPROTOOPT);
2662 	}
2663 	INP_RUNLOCK(inp);
2664 
2665 	error = sooptcopyout(sopt, optdata, optdatalen);
2666 	if (malloc_optdata)
2667 		free(optdata, M_TEMP);
2668 
2669 	return (error);
2670 }
2671 
2672 void
ip6_clearpktopts(struct ip6_pktopts * pktopt,int optname)2673 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2674 {
2675 	if (pktopt == NULL)
2676 		return;
2677 
2678 	if (optname == -1 || optname == IPV6_PKTINFO) {
2679 		if (pktopt->ip6po_pktinfo)
2680 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
2681 		pktopt->ip6po_pktinfo = NULL;
2682 	}
2683 	if (optname == -1 || optname == IPV6_HOPLIMIT)
2684 		pktopt->ip6po_hlim = -1;
2685 	if (optname == -1 || optname == IPV6_TCLASS)
2686 		pktopt->ip6po_tclass = -1;
2687 	if (optname == -1 || optname == IPV6_NEXTHOP) {
2688 		if (pktopt->ip6po_nextroute.ro_nh) {
2689 			NH_FREE(pktopt->ip6po_nextroute.ro_nh);
2690 			pktopt->ip6po_nextroute.ro_nh = NULL;
2691 		}
2692 		if (pktopt->ip6po_nexthop)
2693 			free(pktopt->ip6po_nexthop, M_IP6OPT);
2694 		pktopt->ip6po_nexthop = NULL;
2695 	}
2696 	if (optname == -1 || optname == IPV6_HOPOPTS) {
2697 		if (pktopt->ip6po_hbh)
2698 			free(pktopt->ip6po_hbh, M_IP6OPT);
2699 		pktopt->ip6po_hbh = NULL;
2700 	}
2701 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2702 		if (pktopt->ip6po_dest1)
2703 			free(pktopt->ip6po_dest1, M_IP6OPT);
2704 		pktopt->ip6po_dest1 = NULL;
2705 	}
2706 	if (optname == -1 || optname == IPV6_RTHDR) {
2707 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2708 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2709 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2710 		if (pktopt->ip6po_route.ro_nh) {
2711 			NH_FREE(pktopt->ip6po_route.ro_nh);
2712 			pktopt->ip6po_route.ro_nh = NULL;
2713 		}
2714 	}
2715 	if (optname == -1 || optname == IPV6_DSTOPTS) {
2716 		if (pktopt->ip6po_dest2)
2717 			free(pktopt->ip6po_dest2, M_IP6OPT);
2718 		pktopt->ip6po_dest2 = NULL;
2719 	}
2720 }
2721 
2722 #define PKTOPT_EXTHDRCPY(type) \
2723 do {\
2724 	if (src->type) {\
2725 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2726 		dst->type = malloc(hlen, M_IP6OPT, canwait);\
2727 		if (dst->type == NULL)\
2728 			goto bad;\
2729 		bcopy(src->type, dst->type, hlen);\
2730 	}\
2731 } while (/*CONSTCOND*/ 0)
2732 
2733 static int
copypktopts(struct ip6_pktopts * dst,struct ip6_pktopts * src,int canwait)2734 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2735 {
2736 	if (dst == NULL || src == NULL)  {
2737 		printf("ip6_clearpktopts: invalid argument\n");
2738 		return (EINVAL);
2739 	}
2740 
2741 	dst->ip6po_hlim = src->ip6po_hlim;
2742 	dst->ip6po_tclass = src->ip6po_tclass;
2743 	dst->ip6po_flags = src->ip6po_flags;
2744 	dst->ip6po_minmtu = src->ip6po_minmtu;
2745 	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2746 	if (src->ip6po_pktinfo) {
2747 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2748 		    M_IP6OPT, canwait);
2749 		if (dst->ip6po_pktinfo == NULL)
2750 			goto bad;
2751 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2752 	}
2753 	if (src->ip6po_nexthop) {
2754 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2755 		    M_IP6OPT, canwait);
2756 		if (dst->ip6po_nexthop == NULL)
2757 			goto bad;
2758 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2759 		    src->ip6po_nexthop->sa_len);
2760 	}
2761 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2762 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2763 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2764 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2765 	return (0);
2766 
2767   bad:
2768 	ip6_clearpktopts(dst, -1);
2769 	return (ENOBUFS);
2770 }
2771 #undef PKTOPT_EXTHDRCPY
2772 
2773 struct ip6_pktopts *
ip6_copypktopts(struct ip6_pktopts * src,int canwait)2774 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2775 {
2776 	int error;
2777 	struct ip6_pktopts *dst;
2778 
2779 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2780 	if (dst == NULL)
2781 		return (NULL);
2782 	ip6_initpktopts(dst);
2783 
2784 	if ((error = copypktopts(dst, src, canwait)) != 0) {
2785 		free(dst, M_IP6OPT);
2786 		return (NULL);
2787 	}
2788 
2789 	return (dst);
2790 }
2791 
2792 void
ip6_freepcbopts(struct ip6_pktopts * pktopt)2793 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2794 {
2795 	if (pktopt == NULL)
2796 		return;
2797 
2798 	ip6_clearpktopts(pktopt, -1);
2799 
2800 	free(pktopt, M_IP6OPT);
2801 }
2802 
2803 /*
2804  * Set IPv6 outgoing packet options based on advanced API.
2805  */
2806 int
ip6_setpktopts(struct mbuf * control,struct ip6_pktopts * opt,struct ip6_pktopts * stickyopt,struct ucred * cred,int uproto)2807 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2808     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2809 {
2810 	struct cmsghdr *cm = NULL;
2811 
2812 	if (control == NULL || opt == NULL)
2813 		return (EINVAL);
2814 
2815 	/*
2816 	 * ip6_setpktopt can call ifnet_byindex(), so it's imperative that we
2817 	 * are in the network epoch here.
2818 	 */
2819 	NET_EPOCH_ASSERT();
2820 
2821 	ip6_initpktopts(opt);
2822 	if (stickyopt) {
2823 		int error;
2824 
2825 		/*
2826 		 * If stickyopt is provided, make a local copy of the options
2827 		 * for this particular packet, then override them by ancillary
2828 		 * objects.
2829 		 * XXX: copypktopts() does not copy the cached route to a next
2830 		 * hop (if any).  This is not very good in terms of efficiency,
2831 		 * but we can allow this since this option should be rarely
2832 		 * used.
2833 		 */
2834 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2835 			return (error);
2836 	}
2837 
2838 	/*
2839 	 * XXX: Currently, we assume all the optional information is stored
2840 	 * in a single mbuf.
2841 	 */
2842 	if (control->m_next)
2843 		return (EINVAL);
2844 
2845 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2846 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2847 		int error;
2848 
2849 		if (control->m_len < CMSG_LEN(0))
2850 			return (EINVAL);
2851 
2852 		cm = mtod(control, struct cmsghdr *);
2853 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2854 			return (EINVAL);
2855 		if (cm->cmsg_level != IPPROTO_IPV6)
2856 			continue;
2857 
2858 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2859 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2860 		if (error)
2861 			return (error);
2862 	}
2863 
2864 	return (0);
2865 }
2866 
2867 /*
2868  * Set a particular packet option, as a sticky option or an ancillary data
2869  * item.  "len" can be 0 only when it's a sticky option.
2870  * We have 4 cases of combination of "sticky" and "cmsg":
2871  * "sticky=0, cmsg=0": impossible
2872  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2873  * "sticky=1, cmsg=0": RFC3542 socket option
2874  * "sticky=1, cmsg=1": RFC2292 socket option
2875  */
2876 static int
ip6_setpktopt(int optname,u_char * buf,int len,struct ip6_pktopts * opt,struct ucred * cred,int sticky,int cmsg,int uproto)2877 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2878     struct ucred *cred, int sticky, int cmsg, int uproto)
2879 {
2880 	int minmtupolicy, preftemp;
2881 	int error;
2882 
2883 	NET_EPOCH_ASSERT();
2884 
2885 	if (!sticky && !cmsg) {
2886 #ifdef DIAGNOSTIC
2887 		printf("ip6_setpktopt: impossible case\n");
2888 #endif
2889 		return (EINVAL);
2890 	}
2891 
2892 	/*
2893 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2894 	 * not be specified in the context of RFC3542.  Conversely,
2895 	 * RFC3542 types should not be specified in the context of RFC2292.
2896 	 */
2897 	if (!cmsg) {
2898 		switch (optname) {
2899 		case IPV6_2292PKTINFO:
2900 		case IPV6_2292HOPLIMIT:
2901 		case IPV6_2292NEXTHOP:
2902 		case IPV6_2292HOPOPTS:
2903 		case IPV6_2292DSTOPTS:
2904 		case IPV6_2292RTHDR:
2905 		case IPV6_2292PKTOPTIONS:
2906 			return (ENOPROTOOPT);
2907 		}
2908 	}
2909 	if (sticky && cmsg) {
2910 		switch (optname) {
2911 		case IPV6_PKTINFO:
2912 		case IPV6_HOPLIMIT:
2913 		case IPV6_NEXTHOP:
2914 		case IPV6_HOPOPTS:
2915 		case IPV6_DSTOPTS:
2916 		case IPV6_RTHDRDSTOPTS:
2917 		case IPV6_RTHDR:
2918 		case IPV6_USE_MIN_MTU:
2919 		case IPV6_DONTFRAG:
2920 		case IPV6_TCLASS:
2921 		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2922 			return (ENOPROTOOPT);
2923 		}
2924 	}
2925 
2926 	switch (optname) {
2927 	case IPV6_2292PKTINFO:
2928 	case IPV6_PKTINFO:
2929 	{
2930 		struct ifnet *ifp = NULL;
2931 		struct in6_pktinfo *pktinfo;
2932 
2933 		if (len != sizeof(struct in6_pktinfo))
2934 			return (EINVAL);
2935 
2936 		pktinfo = (struct in6_pktinfo *)buf;
2937 
2938 		/*
2939 		 * An application can clear any sticky IPV6_PKTINFO option by
2940 		 * doing a "regular" setsockopt with ipi6_addr being
2941 		 * in6addr_any and ipi6_ifindex being zero.
2942 		 * [RFC 3542, Section 6]
2943 		 */
2944 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2945 		    pktinfo->ipi6_ifindex == 0 &&
2946 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2947 			ip6_clearpktopts(opt, optname);
2948 			break;
2949 		}
2950 
2951 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2952 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2953 			return (EINVAL);
2954 		}
2955 		if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2956 			return (EINVAL);
2957 		/* validate the interface index if specified. */
2958 		if (pktinfo->ipi6_ifindex) {
2959 			ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2960 			if (ifp == NULL)
2961 				return (ENXIO);
2962 		}
2963 		if (ifp != NULL && (ifp->if_afdata[AF_INET6] == NULL ||
2964 		    (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0))
2965 			return (ENETDOWN);
2966 
2967 		if (ifp != NULL &&
2968 		    !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2969 			struct in6_ifaddr *ia;
2970 
2971 			in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2972 			ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2973 			if (ia == NULL)
2974 				return (EADDRNOTAVAIL);
2975 			ifa_free(&ia->ia_ifa);
2976 		}
2977 		/*
2978 		 * We store the address anyway, and let in6_selectsrc()
2979 		 * validate the specified address.  This is because ipi6_addr
2980 		 * may not have enough information about its scope zone, and
2981 		 * we may need additional information (such as outgoing
2982 		 * interface or the scope zone of a destination address) to
2983 		 * disambiguate the scope.
2984 		 * XXX: the delay of the validation may confuse the
2985 		 * application when it is used as a sticky option.
2986 		 */
2987 		if (opt->ip6po_pktinfo == NULL) {
2988 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2989 			    M_IP6OPT, M_NOWAIT);
2990 			if (opt->ip6po_pktinfo == NULL)
2991 				return (ENOBUFS);
2992 		}
2993 		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2994 		break;
2995 	}
2996 
2997 	case IPV6_2292HOPLIMIT:
2998 	case IPV6_HOPLIMIT:
2999 	{
3000 		int *hlimp;
3001 
3002 		/*
3003 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
3004 		 * to simplify the ordering among hoplimit options.
3005 		 */
3006 		if (optname == IPV6_HOPLIMIT && sticky)
3007 			return (ENOPROTOOPT);
3008 
3009 		if (len != sizeof(int))
3010 			return (EINVAL);
3011 		hlimp = (int *)buf;
3012 		if (*hlimp < -1 || *hlimp > 255)
3013 			return (EINVAL);
3014 
3015 		opt->ip6po_hlim = *hlimp;
3016 		break;
3017 	}
3018 
3019 	case IPV6_TCLASS:
3020 	{
3021 		int tclass;
3022 
3023 		if (len != sizeof(int))
3024 			return (EINVAL);
3025 		tclass = *(int *)buf;
3026 		if (tclass < -1 || tclass > 255)
3027 			return (EINVAL);
3028 
3029 		opt->ip6po_tclass = tclass;
3030 		break;
3031 	}
3032 
3033 	case IPV6_2292NEXTHOP:
3034 	case IPV6_NEXTHOP:
3035 		if (cred != NULL) {
3036 			error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
3037 			if (error)
3038 				return (error);
3039 		}
3040 
3041 		if (len == 0) {	/* just remove the option */
3042 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
3043 			break;
3044 		}
3045 
3046 		/* check if cmsg_len is large enough for sa_len */
3047 		if (len < sizeof(struct sockaddr) || len < *buf)
3048 			return (EINVAL);
3049 
3050 		switch (((struct sockaddr *)buf)->sa_family) {
3051 		case AF_INET6:
3052 		{
3053 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
3054 			int error;
3055 
3056 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
3057 				return (EINVAL);
3058 
3059 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
3060 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
3061 				return (EINVAL);
3062 			}
3063 			if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
3064 			    != 0) {
3065 				return (error);
3066 			}
3067 			break;
3068 		}
3069 		case AF_LINK:	/* should eventually be supported */
3070 		default:
3071 			return (EAFNOSUPPORT);
3072 		}
3073 
3074 		/* turn off the previous option, then set the new option. */
3075 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
3076 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
3077 		if (opt->ip6po_nexthop == NULL)
3078 			return (ENOBUFS);
3079 		bcopy(buf, opt->ip6po_nexthop, *buf);
3080 		break;
3081 
3082 	case IPV6_2292HOPOPTS:
3083 	case IPV6_HOPOPTS:
3084 	{
3085 		struct ip6_hbh *hbh;
3086 		int hbhlen;
3087 
3088 		/*
3089 		 * XXX: We don't allow a non-privileged user to set ANY HbH
3090 		 * options, since per-option restriction has too much
3091 		 * overhead.
3092 		 */
3093 		if (cred != NULL) {
3094 			error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
3095 			if (error)
3096 				return (error);
3097 		}
3098 
3099 		if (len == 0) {
3100 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
3101 			break;	/* just remove the option */
3102 		}
3103 
3104 		/* message length validation */
3105 		if (len < sizeof(struct ip6_hbh))
3106 			return (EINVAL);
3107 		hbh = (struct ip6_hbh *)buf;
3108 		hbhlen = (hbh->ip6h_len + 1) << 3;
3109 		if (len != hbhlen)
3110 			return (EINVAL);
3111 
3112 		/* turn off the previous option, then set the new option. */
3113 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
3114 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
3115 		if (opt->ip6po_hbh == NULL)
3116 			return (ENOBUFS);
3117 		bcopy(hbh, opt->ip6po_hbh, hbhlen);
3118 
3119 		break;
3120 	}
3121 
3122 	case IPV6_2292DSTOPTS:
3123 	case IPV6_DSTOPTS:
3124 	case IPV6_RTHDRDSTOPTS:
3125 	{
3126 		struct ip6_dest *dest, **newdest = NULL;
3127 		int destlen;
3128 
3129 		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
3130 			error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
3131 			if (error)
3132 				return (error);
3133 		}
3134 
3135 		if (len == 0) {
3136 			ip6_clearpktopts(opt, optname);
3137 			break;	/* just remove the option */
3138 		}
3139 
3140 		/* message length validation */
3141 		if (len < sizeof(struct ip6_dest))
3142 			return (EINVAL);
3143 		dest = (struct ip6_dest *)buf;
3144 		destlen = (dest->ip6d_len + 1) << 3;
3145 		if (len != destlen)
3146 			return (EINVAL);
3147 
3148 		/*
3149 		 * Determine the position that the destination options header
3150 		 * should be inserted; before or after the routing header.
3151 		 */
3152 		switch (optname) {
3153 		case IPV6_2292DSTOPTS:
3154 			/*
3155 			 * The old advacned API is ambiguous on this point.
3156 			 * Our approach is to determine the position based
3157 			 * according to the existence of a routing header.
3158 			 * Note, however, that this depends on the order of the
3159 			 * extension headers in the ancillary data; the 1st
3160 			 * part of the destination options header must appear
3161 			 * before the routing header in the ancillary data,
3162 			 * too.
3163 			 * RFC3542 solved the ambiguity by introducing
3164 			 * separate ancillary data or option types.
3165 			 */
3166 			if (opt->ip6po_rthdr == NULL)
3167 				newdest = &opt->ip6po_dest1;
3168 			else
3169 				newdest = &opt->ip6po_dest2;
3170 			break;
3171 		case IPV6_RTHDRDSTOPTS:
3172 			newdest = &opt->ip6po_dest1;
3173 			break;
3174 		case IPV6_DSTOPTS:
3175 			newdest = &opt->ip6po_dest2;
3176 			break;
3177 		}
3178 
3179 		/* turn off the previous option, then set the new option. */
3180 		ip6_clearpktopts(opt, optname);
3181 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
3182 		if (*newdest == NULL)
3183 			return (ENOBUFS);
3184 		bcopy(dest, *newdest, destlen);
3185 
3186 		break;
3187 	}
3188 
3189 	case IPV6_2292RTHDR:
3190 	case IPV6_RTHDR:
3191 	{
3192 		struct ip6_rthdr *rth;
3193 		int rthlen;
3194 
3195 		if (len == 0) {
3196 			ip6_clearpktopts(opt, IPV6_RTHDR);
3197 			break;	/* just remove the option */
3198 		}
3199 
3200 		/* message length validation */
3201 		if (len < sizeof(struct ip6_rthdr))
3202 			return (EINVAL);
3203 		rth = (struct ip6_rthdr *)buf;
3204 		rthlen = (rth->ip6r_len + 1) << 3;
3205 		if (len != rthlen)
3206 			return (EINVAL);
3207 
3208 		switch (rth->ip6r_type) {
3209 		case IPV6_RTHDR_TYPE_0:
3210 			if (rth->ip6r_len == 0)	/* must contain one addr */
3211 				return (EINVAL);
3212 			if (rth->ip6r_len % 2) /* length must be even */
3213 				return (EINVAL);
3214 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
3215 				return (EINVAL);
3216 			break;
3217 		default:
3218 			return (EINVAL);	/* not supported */
3219 		}
3220 
3221 		/* turn off the previous option */
3222 		ip6_clearpktopts(opt, IPV6_RTHDR);
3223 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
3224 		if (opt->ip6po_rthdr == NULL)
3225 			return (ENOBUFS);
3226 		bcopy(rth, opt->ip6po_rthdr, rthlen);
3227 
3228 		break;
3229 	}
3230 
3231 	case IPV6_USE_MIN_MTU:
3232 		if (len != sizeof(int))
3233 			return (EINVAL);
3234 		minmtupolicy = *(int *)buf;
3235 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
3236 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
3237 		    minmtupolicy != IP6PO_MINMTU_ALL) {
3238 			return (EINVAL);
3239 		}
3240 		opt->ip6po_minmtu = minmtupolicy;
3241 		break;
3242 
3243 	case IPV6_DONTFRAG:
3244 		if (len != sizeof(int))
3245 			return (EINVAL);
3246 
3247 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
3248 			/*
3249 			 * we ignore this option for TCP sockets.
3250 			 * (RFC3542 leaves this case unspecified.)
3251 			 */
3252 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
3253 		} else
3254 			opt->ip6po_flags |= IP6PO_DONTFRAG;
3255 		break;
3256 
3257 	case IPV6_PREFER_TEMPADDR:
3258 		if (len != sizeof(int))
3259 			return (EINVAL);
3260 		preftemp = *(int *)buf;
3261 		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3262 		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3263 		    preftemp != IP6PO_TEMPADDR_PREFER) {
3264 			return (EINVAL);
3265 		}
3266 		opt->ip6po_prefer_tempaddr = preftemp;
3267 		break;
3268 
3269 	default:
3270 		return (ENOPROTOOPT);
3271 	} /* end of switch */
3272 
3273 	return (0);
3274 }
3275 
3276 /*
3277  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3278  * packet to the input queue of a specified interface.  Note that this
3279  * calls the output routine of the loopback "driver", but with an interface
3280  * pointer that might NOT be &loif -- easier than replicating that code here.
3281  */
3282 void
ip6_mloopback(struct ifnet * ifp,struct mbuf * m)3283 ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
3284 {
3285 	struct mbuf *copym;
3286 	struct ip6_hdr *ip6;
3287 
3288 	copym = m_copym(m, 0, M_COPYALL, M_NOWAIT);
3289 	if (copym == NULL)
3290 		return;
3291 
3292 	/*
3293 	 * Make sure to deep-copy IPv6 header portion in case the data
3294 	 * is in an mbuf cluster, so that we can safely override the IPv6
3295 	 * header portion later.
3296 	 */
3297 	if (!M_WRITABLE(copym) ||
3298 	    copym->m_len < sizeof(struct ip6_hdr)) {
3299 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
3300 		if (copym == NULL)
3301 			return;
3302 	}
3303 	ip6 = mtod(copym, struct ip6_hdr *);
3304 	/*
3305 	 * clear embedded scope identifiers if necessary.
3306 	 * in6_clearscope will touch the addresses only when necessary.
3307 	 */
3308 	in6_clearscope(&ip6->ip6_src);
3309 	in6_clearscope(&ip6->ip6_dst);
3310 	if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3311 		copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3312 		    CSUM_PSEUDO_HDR;
3313 		copym->m_pkthdr.csum_data = 0xffff;
3314 	}
3315 	if_simloop(ifp, copym, AF_INET6, 0);
3316 }
3317 
3318 /*
3319  * Chop IPv6 header off from the payload.
3320  */
3321 static int
ip6_splithdr(struct mbuf * m,struct ip6_exthdrs * exthdrs)3322 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3323 {
3324 	struct mbuf *mh;
3325 	struct ip6_hdr *ip6;
3326 
3327 	ip6 = mtod(m, struct ip6_hdr *);
3328 	if (m->m_len > sizeof(*ip6)) {
3329 		mh = m_gethdr(M_NOWAIT, MT_DATA);
3330 		if (mh == NULL) {
3331 			m_freem(m);
3332 			return ENOBUFS;
3333 		}
3334 		m_move_pkthdr(mh, m);
3335 		M_ALIGN(mh, sizeof(*ip6));
3336 		m->m_len -= sizeof(*ip6);
3337 		m->m_data += sizeof(*ip6);
3338 		mh->m_next = m;
3339 		m = mh;
3340 		m->m_len = sizeof(*ip6);
3341 		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3342 	}
3343 	exthdrs->ip6e_ip6 = m;
3344 	return 0;
3345 }
3346 
3347 /*
3348  * Compute IPv6 extension header length.
3349  */
3350 int
ip6_optlen(struct inpcb * inp)3351 ip6_optlen(struct inpcb *inp)
3352 {
3353 	int len;
3354 
3355 	if (!inp->in6p_outputopts)
3356 		return 0;
3357 
3358 	len = 0;
3359 #define elen(x) \
3360     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3361 
3362 	len += elen(inp->in6p_outputopts->ip6po_hbh);
3363 	if (inp->in6p_outputopts->ip6po_rthdr)
3364 		/* dest1 is valid with rthdr only */
3365 		len += elen(inp->in6p_outputopts->ip6po_dest1);
3366 	len += elen(inp->in6p_outputopts->ip6po_rthdr);
3367 	len += elen(inp->in6p_outputopts->ip6po_dest2);
3368 	return len;
3369 #undef elen
3370 }
3371