xref: /freebsd/sys/netinet6/ip6_output.c (revision caccbaef8e263b1d769e7bcac1c4617bdc12d484)
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 
63 #include <sys/cdefs.h>
64 #include "opt_inet.h"
65 #include "opt_inet6.h"
66 #include "opt_ipsec.h"
67 #include "opt_kern_tls.h"
68 #include "opt_ratelimit.h"
69 #include "opt_route.h"
70 #include "opt_rss.h"
71 #include "opt_sctp.h"
72 
73 #include <sys/param.h>
74 #include <sys/kernel.h>
75 #include <sys/ktls.h>
76 #include <sys/malloc.h>
77 #include <sys/mbuf.h>
78 #include <sys/errno.h>
79 #include <sys/priv.h>
80 #include <sys/proc.h>
81 #include <sys/protosw.h>
82 #include <sys/socket.h>
83 #include <sys/socketvar.h>
84 #include <sys/syslog.h>
85 #include <sys/ucred.h>
86 
87 #include <machine/in_cksum.h>
88 
89 #include <net/if.h>
90 #include <net/if_var.h>
91 #include <net/if_private.h>
92 #include <net/if_vlan_var.h>
93 #include <net/if_llatbl.h>
94 #include <net/ethernet.h>
95 #include <net/netisr.h>
96 #include <net/route.h>
97 #include <net/route/nhop.h>
98 #include <net/pfil.h>
99 #include <net/rss_config.h>
100 #include <net/vnet.h>
101 
102 #include <netinet/in.h>
103 #include <netinet/in_var.h>
104 #include <netinet/ip_var.h>
105 #include <netinet6/in6_fib.h>
106 #include <netinet6/in6_var.h>
107 #include <netinet/ip6.h>
108 #include <netinet/icmp6.h>
109 #include <netinet6/ip6_var.h>
110 #include <netinet/in_pcb.h>
111 #include <netinet/tcp_var.h>
112 #include <netinet6/nd6.h>
113 #include <netinet6/in6_rss.h>
114 
115 #include <netipsec/ipsec_support.h>
116 #if defined(SCTP) || defined(SCTP_SUPPORT)
117 #include <netinet/sctp.h>
118 #include <netinet/sctp_crc32.h>
119 #endif
120 
121 #include <netinet6/scope6_var.h>
122 
123 extern int in6_mcast_loop;
124 
125 struct ip6_exthdrs {
126 	struct mbuf *ip6e_ip6;
127 	struct mbuf *ip6e_hbh;
128 	struct mbuf *ip6e_dest1;
129 	struct mbuf *ip6e_rthdr;
130 	struct mbuf *ip6e_dest2;
131 };
132 
133 static MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
134 
135 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
136 			   struct ucred *, int);
137 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
138 	struct socket *, struct sockopt *);
139 static int ip6_getpcbopt(struct inpcb *, int, struct sockopt *);
140 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
141 	struct ucred *, int, int, int);
142 
143 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
144 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
145 	struct ip6_frag **);
146 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
147 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
148 static int ip6_getpmtu(struct route_in6 *, int,
149 	struct ifnet *, const struct in6_addr *, u_long *, int *, u_int,
150 	u_int);
151 static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
152 	u_long *, int *, u_int);
153 static int ip6_getpmtu_ctl(u_int, const struct in6_addr *, u_long *);
154 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
155 
156 /*
157  * Make an extension header from option data.  hp is the source,
158  * mp is the destination, and _ol is the optlen.
159  */
160 #define	MAKE_EXTHDR(hp, mp, _ol)					\
161     do {								\
162 	struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
163 	error = ip6_copyexthdr((mp), (caddr_t)(hp),		\
164 	    ((eh)->ip6e_len + 1) << 3);				\
165 	if (error)						\
166 		goto freehdrs;					\
167 	(_ol) += (*(mp))->m_len;				\
168     } while (/*CONSTCOND*/ 0)
169 
170 /*
171  * Form a chain of extension headers.
172  * m is the extension header mbuf
173  * mp is the previous mbuf in the chain
174  * p is the next header
175  * i is the type of option.
176  */
177 #define MAKE_CHAIN(m, mp, p, i)\
178     do {\
179 	if (m) {\
180 		if (!hdrsplit) \
181 			panic("%s:%d: assumption failed: "\
182 			    "hdr not split: hdrsplit %d exthdrs %p",\
183 			    __func__, __LINE__, hdrsplit, &exthdrs);\
184 		*mtod((m), u_char *) = *(p);\
185 		*(p) = (i);\
186 		p = mtod((m), u_char *);\
187 		(m)->m_next = (mp)->m_next;\
188 		(mp)->m_next = (m);\
189 		(mp) = (m);\
190 	}\
191     } while (/*CONSTCOND*/ 0)
192 
193 void
in6_delayed_cksum(struct mbuf * m,uint32_t plen,u_short offset)194 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
195 {
196 	u_short csum;
197 
198 	csum = in_cksum_skip(m, offset + plen, offset);
199 	if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
200 		csum = 0xffff;
201 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
202 
203 	if (offset + sizeof(csum) > m->m_len)
204 		m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
205 	else
206 		*(u_short *)mtodo(m, offset) = csum;
207 }
208 
209 static void
ip6_output_delayed_csum(struct mbuf * m,struct ifnet * ifp,int csum_flags,int plen,int optlen)210 ip6_output_delayed_csum(struct mbuf *m, struct ifnet *ifp, int csum_flags,
211     int plen, int optlen)
212 {
213 
214 	KASSERT((plen >= optlen), ("%s:%d: plen %d < optlen %d, m %p, ifp %p "
215 	    "csum_flags %#x",
216 	    __func__, __LINE__, plen, optlen, m, ifp, csum_flags));
217 
218 	if (csum_flags & CSUM_DELAY_DATA_IPV6) {
219 		in6_delayed_cksum(m, plen - optlen,
220 		    sizeof(struct ip6_hdr) + optlen);
221 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
222 	}
223 #if defined(SCTP) || defined(SCTP_SUPPORT)
224 	if (csum_flags & CSUM_SCTP_IPV6) {
225 		sctp_delayed_cksum(m, sizeof(struct ip6_hdr) + optlen);
226 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
227 	}
228 #endif
229 }
230 
231 int
ip6_fragment(struct ifnet * ifp,struct mbuf * m0,int hlen,u_char nextproto,int fraglen,uint32_t id)232 ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
233     int fraglen , uint32_t id)
234 {
235 	struct mbuf *m, **mnext, *m_frgpart;
236 	struct ip6_hdr *ip6, *mhip6;
237 	struct ip6_frag *ip6f;
238 	int off;
239 	int error;
240 	int tlen = m0->m_pkthdr.len;
241 
242 	KASSERT((fraglen % 8 == 0), ("Fragment length must be a multiple of 8"));
243 
244 	m = m0;
245 	ip6 = mtod(m, struct ip6_hdr *);
246 	mnext = &m->m_nextpkt;
247 
248 	for (off = hlen; off < tlen; off += fraglen) {
249 		m = m_gethdr(M_NOWAIT, MT_DATA);
250 		if (!m) {
251 			IP6STAT_INC(ip6s_odropped);
252 			return (ENOBUFS);
253 		}
254 
255 		/*
256 		 * Make sure the complete packet header gets copied
257 		 * from the originating mbuf to the newly created
258 		 * mbuf. This also ensures that existing firewall
259 		 * classification(s), VLAN tags and so on get copied
260 		 * to the resulting fragmented packet(s):
261 		 */
262 		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
263 			m_free(m);
264 			IP6STAT_INC(ip6s_odropped);
265 			return (ENOBUFS);
266 		}
267 
268 		*mnext = m;
269 		mnext = &m->m_nextpkt;
270 		m->m_data += max_linkhdr;
271 		mhip6 = mtod(m, struct ip6_hdr *);
272 		*mhip6 = *ip6;
273 		m->m_len = sizeof(*mhip6);
274 		error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
275 		if (error) {
276 			IP6STAT_INC(ip6s_odropped);
277 			return (error);
278 		}
279 		ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
280 		if (off + fraglen >= tlen)
281 			fraglen = tlen - off;
282 		else
283 			ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
284 		mhip6->ip6_plen = htons((u_short)(fraglen + hlen +
285 		    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
286 		if ((m_frgpart = m_copym(m0, off, fraglen, M_NOWAIT)) == NULL) {
287 			IP6STAT_INC(ip6s_odropped);
288 			return (ENOBUFS);
289 		}
290 		m_cat(m, m_frgpart);
291 		m->m_pkthdr.len = fraglen + hlen + sizeof(*ip6f);
292 		ip6f->ip6f_reserved = 0;
293 		ip6f->ip6f_ident = id;
294 		ip6f->ip6f_nxt = nextproto;
295 		IP6STAT_INC(ip6s_ofragments);
296 		in6_ifstat_inc(ifp, ifs6_out_fragcreat);
297 	}
298 
299 	return (0);
300 }
301 
302 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)303 ip6_output_send(struct inpcb *inp, struct ifnet *ifp, struct ifnet *origifp,
304     struct mbuf *m, struct sockaddr_in6 *dst, struct route_in6 *ro,
305     bool stamp_tag)
306 {
307 #ifdef KERN_TLS
308 	struct ktls_session *tls = NULL;
309 #endif
310 	struct m_snd_tag *mst;
311 	int error;
312 
313 	MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
314 	mst = NULL;
315 
316 #ifdef KERN_TLS
317 	/*
318 	 * If this is an unencrypted TLS record, save a reference to
319 	 * the record.  This local reference is used to call
320 	 * ktls_output_eagain after the mbuf has been freed (thus
321 	 * dropping the mbuf's reference) in if_output.
322 	 */
323 	if (m->m_next != NULL && mbuf_has_tls_session(m->m_next)) {
324 		tls = ktls_hold(m->m_next->m_epg_tls);
325 		mst = tls->snd_tag;
326 
327 		/*
328 		 * If a TLS session doesn't have a valid tag, it must
329 		 * have had an earlier ifp mismatch, so drop this
330 		 * packet.
331 		 */
332 		if (mst == NULL) {
333 			m_freem(m);
334 			error = EAGAIN;
335 			goto done;
336 		}
337 		/*
338 		 * Always stamp tags that include NIC ktls.
339 		 */
340 		stamp_tag = true;
341 	}
342 #endif
343 #ifdef RATELIMIT
344 	if (inp != NULL && mst == NULL) {
345 		if ((inp->inp_flags2 & INP_RATE_LIMIT_CHANGED) != 0 ||
346 		    (inp->inp_snd_tag != NULL &&
347 		    inp->inp_snd_tag->ifp != ifp))
348 			in_pcboutput_txrtlmt(inp, ifp, m);
349 
350 		if (inp->inp_snd_tag != NULL)
351 			mst = inp->inp_snd_tag;
352 	}
353 #endif
354 	if (stamp_tag && mst != NULL) {
355 		KASSERT(m->m_pkthdr.rcvif == NULL,
356 		    ("trying to add a send tag to a forwarded packet"));
357 		if (mst->ifp != ifp) {
358 			m_freem(m);
359 			error = EAGAIN;
360 			goto done;
361 		}
362 
363 		/* stamp send tag on mbuf */
364 		m->m_pkthdr.snd_tag = m_snd_tag_ref(mst);
365 		m->m_pkthdr.csum_flags |= CSUM_SND_TAG;
366 	}
367 
368 	error = nd6_output_ifp(ifp, origifp, m, dst, (struct route *)ro);
369 
370 done:
371 	/* Check for route change invalidating send tags. */
372 #ifdef KERN_TLS
373 	if (tls != NULL) {
374 		if (error == EAGAIN)
375 			error = ktls_output_eagain(inp, tls);
376 		ktls_free(tls);
377 	}
378 #endif
379 #ifdef RATELIMIT
380 	if (error == EAGAIN)
381 		in_pcboutput_eagain(inp);
382 #endif
383 	return (error);
384 }
385 
386 /*
387  * IP6 output.
388  * The packet in mbuf chain m contains a skeletal IP6 header (with pri, len,
389  * nxt, hlim, src, dst).
390  * This function may modify ver and hlim only.
391  * The mbuf chain containing the packet will be freed.
392  * The mbuf opt, if present, will not be freed.
393  * If route_in6 ro is present and has ro_nh initialized, route lookup would be
394  * skipped and ro->ro_nh would be used. If ro is present but ro->ro_nh is NULL,
395  * then result of route lookup is stored in ro->ro_nh.
396  *
397  * Type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and nd_ifinfo.linkmtu
398  * is uint32_t.  So we use u_long to hold largest one, which is rt_mtu.
399  *
400  * ifpp - XXX: just for statistics
401  */
402 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)403 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
404     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
405     struct ifnet **ifpp, struct inpcb *inp)
406 {
407 	struct ip6_hdr *ip6;
408 	struct ifnet *ifp, *origifp;
409 	struct mbuf *m = m0;
410 	struct mbuf *mprev;
411 	struct route_in6 *ro_pmtu;
412 	struct nhop_object *nh;
413 	struct sockaddr_in6 *dst, sin6, src_sa, dst_sa;
414 	struct in6_addr odst;
415 	u_char *nexthdrp;
416 	int tlen, len;
417 	int error = 0;
418 	int vlan_pcp = -1;
419 	struct in6_ifaddr *ia = NULL;
420 	u_long mtu;
421 	int alwaysfrag, dontfrag;
422 	u_int32_t optlen, plen = 0, unfragpartlen;
423 	struct ip6_exthdrs exthdrs;
424 	struct in6_addr src0, dst0;
425 	u_int32_t zone;
426 	bool hdrsplit;
427 	int sw_csum, tso;
428 	int needfiblookup;
429 	uint32_t fibnum;
430 	struct m_tag *fwd_tag = NULL;
431 	uint32_t id;
432 	uint32_t optvalid;
433 
434 	NET_EPOCH_ASSERT();
435 
436 	if (inp != NULL) {
437 		INP_LOCK_ASSERT(inp);
438 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
439 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
440 			/* Unconditionally set flowid. */
441 			m->m_pkthdr.flowid = inp->inp_flowid;
442 			M_HASHTYPE_SET(m, inp->inp_flowtype);
443 		}
444 		if ((inp->inp_flags2 & INP_2PCP_SET) != 0)
445 			vlan_pcp = (inp->inp_flags2 & INP_2PCP_MASK) >>
446 			    INP_2PCP_SHIFT;
447 #ifdef NUMA
448 		m->m_pkthdr.numa_domain = inp->inp_numa_domain;
449 #endif
450 	}
451 
452 	/* Source address validation. */
453 	ip6 = mtod(m, struct ip6_hdr *);
454 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
455 	    (flags & IPV6_UNSPECSRC) == 0) {
456 		error = EOPNOTSUPP;
457 		IP6STAT_INC(ip6s_badscope);
458 		goto bad;
459 	}
460 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
461 		error = EOPNOTSUPP;
462 		IP6STAT_INC(ip6s_badscope);
463 		goto bad;
464 	}
465 
466 	/*
467 	 * If we are given packet options to add extension headers prepare them.
468 	 * Calculate the total length of the extension header chain.
469 	 * Keep the length of the unfragmentable part for fragmentation.
470 	 */
471 	bzero(&exthdrs, sizeof(exthdrs));
472 	optlen = optvalid = 0;
473 	unfragpartlen = sizeof(struct ip6_hdr);
474 	if (opt) {
475 		optvalid = opt->ip6po_valid;
476 
477 		/* Hop-by-Hop options header. */
478 		if ((optvalid & IP6PO_VALID_HBH) != 0)
479 			MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh, optlen);
480 
481 		/* Destination options header (1st part). */
482 		if ((optvalid & IP6PO_VALID_RHINFO) != 0) {
483 #ifndef RTHDR_SUPPORT_IMPLEMENTED
484 			/*
485 			 * If there is a routing header, discard the packet
486 			 * right away here. RH0/1 are obsolete and we do not
487 			 * currently support RH2/3/4.
488 			 * People trying to use RH253/254 may want to disable
489 			 * this check.
490 			 * The moment we do support any routing header (again)
491 			 * this block should check the routing type more
492 			 * selectively.
493 			 */
494 			error = EINVAL;
495 			goto bad;
496 #endif
497 
498 			/*
499 			 * Destination options header (1st part).
500 			 * This only makes sense with a routing header.
501 			 * See Section 9.2 of RFC 3542.
502 			 * Disabling this part just for MIP6 convenience is
503 			 * a bad idea.  We need to think carefully about a
504 			 * way to make the advanced API coexist with MIP6
505 			 * options, which might automatically be inserted in
506 			 * the kernel.
507 			 */
508 			if ((optvalid & IP6PO_VALID_DEST1) != 0)
509 				MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1,
510 				    optlen);
511 		}
512 		/* Routing header. */
513 		if ((optvalid & IP6PO_VALID_RHINFO) != 0)
514 			MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr, optlen);
515 
516 		unfragpartlen += optlen;
517 
518 		/*
519 		 * NOTE: we don't add AH/ESP length here (done in
520 		 * ip6_ipsec_output()).
521 		 */
522 
523 		/* Destination options header (2nd part). */
524 		if ((optvalid & IP6PO_VALID_DEST2) != 0)
525 			MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2, optlen);
526 	}
527 
528 	/*
529 	 * If there is at least one extension header,
530 	 * separate IP6 header from the payload.
531 	 */
532 	hdrsplit = false;
533 	if (optlen) {
534 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
535 			m = NULL;
536 			goto freehdrs;
537 		}
538 		m = exthdrs.ip6e_ip6;
539 		ip6 = mtod(m, struct ip6_hdr *);
540 		hdrsplit = true;
541 	}
542 
543 	/* Adjust mbuf packet header length. */
544 	m->m_pkthdr.len += optlen;
545 	plen = m->m_pkthdr.len - sizeof(*ip6);
546 
547 	/* If this is a jumbo payload, insert a jumbo payload option. */
548 	if (plen > IPV6_MAXPACKET) {
549 		if (!hdrsplit) {
550 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
551 				m = NULL;
552 				goto freehdrs;
553 			}
554 			m = exthdrs.ip6e_ip6;
555 			ip6 = mtod(m, struct ip6_hdr *);
556 			hdrsplit = true;
557 		}
558 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
559 			goto freehdrs;
560 		ip6->ip6_plen = 0;
561 	} else
562 		ip6->ip6_plen = htons(plen);
563 	nexthdrp = &ip6->ip6_nxt;
564 
565 	if (optlen) {
566 		/*
567 		 * Concatenate headers and fill in next header fields.
568 		 * Here we have, on "m"
569 		 *	IPv6 payload
570 		 * and we insert headers accordingly.
571 		 * Finally, we should be getting:
572 		 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload].
573 		 *
574 		 * During the header composing process "m" points to IPv6
575 		 * header.  "mprev" points to an extension header prior to esp.
576 		 */
577 		mprev = m;
578 
579 		/*
580 		 * We treat dest2 specially.  This makes IPsec processing
581 		 * much easier.  The goal here is to make mprev point the
582 		 * mbuf prior to dest2.
583 		 *
584 		 * Result: IPv6 dest2 payload.
585 		 * m and mprev will point to IPv6 header.
586 		 */
587 		if (exthdrs.ip6e_dest2) {
588 			if (!hdrsplit)
589 				panic("%s:%d: assumption failed: "
590 				    "hdr not split: hdrsplit %d exthdrs %p",
591 				    __func__, __LINE__, hdrsplit, &exthdrs);
592 			exthdrs.ip6e_dest2->m_next = m->m_next;
593 			m->m_next = exthdrs.ip6e_dest2;
594 			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
595 			ip6->ip6_nxt = IPPROTO_DSTOPTS;
596 		}
597 
598 		/*
599 		 * Result: IPv6 hbh dest1 rthdr dest2 payload.
600 		 * m will point to IPv6 header.  mprev will point to the
601 		 * extension header prior to dest2 (rthdr in the above case).
602 		 */
603 		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
604 		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
605 			   IPPROTO_DSTOPTS);
606 		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
607 			   IPPROTO_ROUTING);
608 	}
609 
610 	IP6STAT_INC(ip6s_localout);
611 
612 	/* Route packet. */
613 	ro_pmtu = ro;
614 	if ((optvalid & IP6PO_VALID_RHINFO) != 0)
615 		ro = &opt->ip6po_route;
616 	if (ro != NULL)
617 		dst = (struct sockaddr_in6 *)&ro->ro_dst;
618 	else
619 		dst = &sin6;
620 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
621 
622 again:
623 	/*
624 	 * If specified, try to fill in the traffic class field.
625 	 * Do not override if a non-zero value is already set.
626 	 * We check the diffserv field and the ECN field separately.
627 	 */
628 	if ((optvalid & IP6PO_VALID_TC) != 0){
629 		int mask = 0;
630 
631 		if (IPV6_DSCP(ip6) == 0)
632 			mask |= 0xfc;
633 		if (IPV6_ECN(ip6) == 0)
634 			mask |= 0x03;
635 		if (mask != 0)
636 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
637 	}
638 
639 	/* Fill in or override the hop limit field, if necessary. */
640 	if ((optvalid & IP6PO_VALID_HLIM) != 0)
641 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
642 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
643 		if (im6o != NULL)
644 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
645 		else
646 			ip6->ip6_hlim = V_ip6_defmcasthlim;
647 	}
648 
649 	if (ro == NULL || ro->ro_nh == NULL) {
650 		bzero(dst, sizeof(*dst));
651 		dst->sin6_family = AF_INET6;
652 		dst->sin6_len = sizeof(*dst);
653 		dst->sin6_addr = ip6->ip6_dst;
654 	}
655 	/*
656 	 * Validate route against routing table changes.
657 	 * Make sure that the address family is set in route.
658 	 */
659 	nh = NULL;
660 	ifp = NULL;
661 	mtu = 0;
662 	if (ro != NULL) {
663 		if (ro->ro_nh != NULL && inp != NULL) {
664 			ro->ro_dst.sin6_family = AF_INET6; /* XXX KASSERT? */
665 			NH_VALIDATE((struct route *)ro, &inp->inp_rt_cookie,
666 			    fibnum);
667 		}
668 		if (ro->ro_nh != NULL && fwd_tag == NULL &&
669 		    (!NH_IS_VALID(ro->ro_nh) ||
670 		    ro->ro_dst.sin6_family != AF_INET6 ||
671 		    !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)))
672 			RO_INVALIDATE_CACHE(ro);
673 
674 		if (ro->ro_nh != NULL && fwd_tag == NULL &&
675 		    ro->ro_dst.sin6_family == AF_INET6 &&
676 		    IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)) {
677 			/* Nexthop is valid and contains valid ifp */
678 			nh = ro->ro_nh;
679 		} else {
680 			if (ro->ro_lle)
681 				LLE_FREE(ro->ro_lle);	/* zeros ro_lle */
682 			ro->ro_lle = NULL;
683 			if (fwd_tag == NULL) {
684 				bzero(&dst_sa, sizeof(dst_sa));
685 				dst_sa.sin6_family = AF_INET6;
686 				dst_sa.sin6_len = sizeof(dst_sa);
687 				dst_sa.sin6_addr = ip6->ip6_dst;
688 			}
689 			error = in6_selectroute(&dst_sa, opt, im6o, ro, &ifp,
690 			    &nh, fibnum, m->m_pkthdr.flowid);
691 			if (error != 0) {
692 				IP6STAT_INC(ip6s_noroute);
693 				if (ifp != NULL)
694 					in6_ifstat_inc(ifp, ifs6_out_discard);
695 				goto bad;
696 			}
697 			/*
698 			 * At this point at least @ifp is not NULL
699 			 * Can be the case when dst is multicast, link-local or
700 			 * interface is explicitly specificed by the caller.
701 			 */
702 		}
703 		if (nh == NULL) {
704 			/*
705 			 * If in6_selectroute() does not return a nexthop
706 			 * dst may not have been updated.
707 			 */
708 			*dst = dst_sa;	/* XXX */
709 			origifp = ifp;
710 			mtu = ifp->if_mtu;
711 		} else {
712 			ifp = nh->nh_ifp;
713 			origifp = nh->nh_aifp;
714 			ia = (struct in6_ifaddr *)(nh->nh_ifa);
715 			counter_u64_add(nh->nh_pksent, 1);
716 		}
717 	} else {
718 		struct nhop_object *nh;
719 		struct in6_addr kdst;
720 		uint32_t scopeid;
721 
722 		if (fwd_tag == NULL) {
723 			bzero(&dst_sa, sizeof(dst_sa));
724 			dst_sa.sin6_family = AF_INET6;
725 			dst_sa.sin6_len = sizeof(dst_sa);
726 			dst_sa.sin6_addr = ip6->ip6_dst;
727 		}
728 
729 		if (IN6_IS_ADDR_MULTICAST(&dst_sa.sin6_addr) &&
730 		    im6o != NULL &&
731 		    (ifp = im6o->im6o_multicast_ifp) != NULL) {
732 			/* We do not need a route lookup. */
733 			*dst = dst_sa;	/* XXX */
734 			origifp = ifp;
735 			goto nonh6lookup;
736 		}
737 
738 		in6_splitscope(&dst_sa.sin6_addr, &kdst, &scopeid);
739 
740 		if (IN6_IS_ADDR_MC_LINKLOCAL(&dst_sa.sin6_addr) ||
741 		    IN6_IS_ADDR_MC_NODELOCAL(&dst_sa.sin6_addr)) {
742 			if (scopeid > 0) {
743 				ifp = in6_getlinkifnet(scopeid);
744 				if (ifp == NULL) {
745 					error = EHOSTUNREACH;
746 					goto bad;
747 				}
748 				*dst = dst_sa;	/* XXX */
749 				origifp = ifp;
750 				goto nonh6lookup;
751 			}
752 		}
753 
754 		nh = fib6_lookup(fibnum, &kdst, scopeid, NHR_NONE,
755 		    m->m_pkthdr.flowid);
756 		if (nh == NULL) {
757 			IP6STAT_INC(ip6s_noroute);
758 			/* No ifp in6_ifstat_inc(ifp, ifs6_out_discard); */
759 			error = EHOSTUNREACH;
760 			goto bad;
761 		}
762 
763 		ifp = nh->nh_ifp;
764 		origifp = nh->nh_aifp;
765 		ia = ifatoia6(nh->nh_ifa);
766 		if (nh->nh_flags & NHF_GATEWAY)
767 			dst->sin6_addr = nh->gw6_sa.sin6_addr;
768 		else if (fwd_tag != NULL)
769 			dst->sin6_addr = dst_sa.sin6_addr;
770 nonh6lookup:
771 		;
772 	}
773 	/*
774 	 * At this point ifp MUST be pointing to the valid transmit ifp.
775 	 * origifp MUST be valid and pointing to either the same ifp or,
776 	 * in case of loopback output, to the interface which ip6_src
777 	 * belongs to.
778 	 * Examples:
779 	 *  fe80::1%em0 -> fe80::2%em0 -> ifp=em0, origifp=em0
780 	 *  fe80::1%em0 -> fe80::1%em0 -> ifp=lo0, origifp=em0
781 	 *  ::1 -> ::1 -> ifp=lo0, origifp=lo0
782 	 *
783 	 * mtu can be 0 and will be refined later.
784 	 */
785 	KASSERT((ifp != NULL), ("output interface must not be NULL"));
786 	KASSERT((origifp != NULL), ("output address interface must not be NULL"));
787 
788 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
789 	/*
790 	 * IPSec checking which handles several cases.
791 	 * FAST IPSEC: We re-injected the packet.
792 	 * XXX: need scope argument.
793 	 */
794 	if (IPSEC_ENABLED(ipv6)) {
795 		if ((error = IPSEC_OUTPUT(ipv6, ifp, m, inp, mtu == 0 ?
796 		    ifp->if_mtu : mtu)) != 0) {
797 			if (error == EINPROGRESS)
798 				error = 0;
799 			goto done;
800 		}
801 	}
802 #endif /* IPSEC */
803 
804 	if ((flags & IPV6_FORWARDING) == 0) {
805 		/* XXX: the FORWARDING flag can be set for mrouting. */
806 		in6_ifstat_inc(ifp, ifs6_out_request);
807 	}
808 
809 	/* Setup data structures for scope ID checks. */
810 	src0 = ip6->ip6_src;
811 	bzero(&src_sa, sizeof(src_sa));
812 	src_sa.sin6_family = AF_INET6;
813 	src_sa.sin6_len = sizeof(src_sa);
814 	src_sa.sin6_addr = ip6->ip6_src;
815 
816 	dst0 = ip6->ip6_dst;
817 	/* Re-initialize to be sure. */
818 	bzero(&dst_sa, sizeof(dst_sa));
819 	dst_sa.sin6_family = AF_INET6;
820 	dst_sa.sin6_len = sizeof(dst_sa);
821 	dst_sa.sin6_addr = ip6->ip6_dst;
822 
823 	/* Check for valid scope ID. */
824 	if (in6_setscope(&src0, origifp, &zone) == 0 &&
825 	    sa6_recoverscope(&src_sa) == 0 && zone == src_sa.sin6_scope_id &&
826 	    in6_setscope(&dst0, origifp, &zone) == 0 &&
827 	    sa6_recoverscope(&dst_sa) == 0 && zone == dst_sa.sin6_scope_id) {
828 		/*
829 		 * The outgoing interface is in the zone of the source
830 		 * and destination addresses.
831 		 *
832 		 */
833 	} else if ((origifp->if_flags & IFF_LOOPBACK) == 0 ||
834 	    sa6_recoverscope(&src_sa) != 0 ||
835 	    sa6_recoverscope(&dst_sa) != 0 ||
836 	    dst_sa.sin6_scope_id == 0 ||
837 	    (src_sa.sin6_scope_id != 0 &&
838 	    src_sa.sin6_scope_id != dst_sa.sin6_scope_id) ||
839 	    ifnet_byindex(dst_sa.sin6_scope_id) == NULL) {
840 		/*
841 		 * If the destination network interface is not a
842 		 * loopback interface, or the destination network
843 		 * address has no scope ID, or the source address has
844 		 * a scope ID set which is different from the
845 		 * destination address one, or there is no network
846 		 * interface representing this scope ID, the address
847 		 * pair is considered invalid.
848 		 */
849 		IP6STAT_INC(ip6s_badscope);
850 		in6_ifstat_inc(origifp, ifs6_out_discard);
851 		if (error == 0)
852 			error = EHOSTUNREACH; /* XXX */
853 		goto bad;
854 	}
855 	/* All scope ID checks are successful. */
856 
857 	if (nh && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
858 		if ((optvalid & IP6PO_VALID_NHINFO) != 0) {
859 			/*
860 			 * The nexthop is explicitly specified by the
861 			 * application.  We assume the next hop is an IPv6
862 			 * address.
863 			 */
864 			dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
865 		}
866 		else if ((nh->nh_flags & NHF_GATEWAY))
867 			dst = &nh->gw6_sa;
868 	}
869 
870 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
871 		m->m_flags &= ~(M_BCAST | M_MCAST); /* Just in case. */
872 	} else {
873 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
874 		in6_ifstat_inc(ifp, ifs6_out_mcast);
875 
876 		/* Confirm that the outgoing interface supports multicast. */
877 		if (!(ifp->if_flags & IFF_MULTICAST)) {
878 			IP6STAT_INC(ip6s_noroute);
879 			in6_ifstat_inc(ifp, ifs6_out_discard);
880 			error = ENETUNREACH;
881 			goto bad;
882 		}
883 		if ((im6o == NULL && in6_mcast_loop) ||
884 		    (im6o && im6o->im6o_multicast_loop)) {
885 			/*
886 			 * Loop back multicast datagram if not expressly
887 			 * forbidden to do so, even if we have not joined
888 			 * the address; protocols will filter it later,
889 			 * thus deferring a hash lookup and lock acquisition
890 			 * at the expense of an m_copym().
891 			 */
892 			ip6_mloopback(ifp, m);
893 		} else {
894 			/*
895 			 * If we are acting as a multicast router, perform
896 			 * multicast forwarding as if the packet had just
897 			 * arrived on the interface to which we are about
898 			 * to send.  The multicast forwarding function
899 			 * recursively calls this function, using the
900 			 * IPV6_FORWARDING flag to prevent infinite recursion.
901 			 *
902 			 * Multicasts that are looped back by ip6_mloopback(),
903 			 * above, will be forwarded by the ip6_input() routine,
904 			 * if necessary.
905 			 */
906 			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
907 				/*
908 				 * XXX: ip6_mforward expects that rcvif is NULL
909 				 * when it is called from the originating path.
910 				 * However, it may not always be the case.
911 				 */
912 				m->m_pkthdr.rcvif = NULL;
913 				if (ip6_mforward(ip6, ifp, m) != 0) {
914 					m_freem(m);
915 					goto done;
916 				}
917 			}
918 		}
919 		/*
920 		 * Multicasts with a hoplimit of zero may be looped back,
921 		 * above, but must not be transmitted on a network.
922 		 * Also, multicasts addressed to the loopback interface
923 		 * are not sent -- the above call to ip6_mloopback() will
924 		 * loop back a copy if this host actually belongs to the
925 		 * destination group on the loopback interface.
926 		 */
927 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
928 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
929 			m_freem(m);
930 			goto done;
931 		}
932 	}
933 
934 	/*
935 	 * Fill the outgoing inteface to tell the upper layer
936 	 * to increment per-interface statistics.
937 	 */
938 	if (ifpp)
939 		*ifpp = ifp;
940 
941 	/* Determine path MTU. */
942 	if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &ip6->ip6_dst,
943 		    &mtu, &alwaysfrag, fibnum, *nexthdrp)) != 0)
944 		goto bad;
945 	KASSERT(mtu > 0, ("%s:%d: mtu %ld, ro_pmtu %p ro %p ifp %p "
946 	    "alwaysfrag %d fibnum %u\n", __func__, __LINE__, mtu, ro_pmtu, ro,
947 	    ifp, alwaysfrag, fibnum));
948 
949 	/*
950 	 * The caller of this function may specify to use the minimum MTU
951 	 * in some cases.
952 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
953 	 * setting.  The logic is a bit complicated; by default, unicast
954 	 * packets will follow path MTU while multicast packets will be sent at
955 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
956 	 * including unicast ones will be sent at the minimum MTU.  Multicast
957 	 * packets will always be sent at the minimum MTU unless
958 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
959 	 * See RFC 3542 for more details.
960 	 */
961 	if (mtu > IPV6_MMTU) {
962 		if ((flags & IPV6_MINMTU))
963 			mtu = IPV6_MMTU;
964 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
965 			mtu = IPV6_MMTU;
966 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
967 			 (opt == NULL ||
968 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
969 			mtu = IPV6_MMTU;
970 		}
971 	}
972 
973 	/*
974 	 * Clear embedded scope identifiers if necessary.
975 	 * in6_clearscope() will touch the addresses only when necessary.
976 	 */
977 	in6_clearscope(&ip6->ip6_src);
978 	in6_clearscope(&ip6->ip6_dst);
979 
980 	/*
981 	 * If the outgoing packet contains a hop-by-hop options header,
982 	 * it must be examined and processed even by the source node.
983 	 * (RFC 2460, section 4.)
984 	 */
985 	if (exthdrs.ip6e_hbh) {
986 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
987 		u_int32_t dummy; /* XXX unused */
988 		u_int32_t plen = 0; /* XXX: ip6_process will check the value */
989 
990 #ifdef DIAGNOSTIC
991 		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
992 			panic("ip6e_hbh is not contiguous");
993 #endif
994 		/*
995 		 *  XXX: if we have to send an ICMPv6 error to the sender,
996 		 *       we need the M_LOOP flag since icmp6_error() expects
997 		 *       the IPv6 and the hop-by-hop options header are
998 		 *       contiguous unless the flag is set.
999 		 */
1000 		m->m_flags |= M_LOOP;
1001 		m->m_pkthdr.rcvif = ifp;
1002 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
1003 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
1004 		    &dummy, &plen) < 0) {
1005 			/* m was already freed at this point. */
1006 			error = EINVAL;/* better error? */
1007 			goto done;
1008 		}
1009 		m->m_flags &= ~M_LOOP; /* XXX */
1010 		m->m_pkthdr.rcvif = NULL;
1011 	}
1012 
1013 	/* Jump over all PFIL processing if hooks are not active. */
1014 	if (!PFIL_HOOKED_OUT(V_inet6_pfil_head))
1015 		goto passout;
1016 
1017 	odst = ip6->ip6_dst;
1018 	/* Run through list of hooks for output packets. */
1019 	switch (pfil_mbuf_out(V_inet6_pfil_head, &m, ifp, inp)) {
1020 	case PFIL_PASS:
1021 		ip6 = mtod(m, struct ip6_hdr *);
1022 		break;
1023 	case PFIL_DROPPED:
1024 		error = EACCES;
1025 		/* FALLTHROUGH */
1026 	case PFIL_CONSUMED:
1027 		goto done;
1028 	}
1029 
1030 	needfiblookup = 0;
1031 	/* See if destination IP address was changed by packet filter. */
1032 	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
1033 		m->m_flags |= M_SKIP_FIREWALL;
1034 		/* If destination is now ourself drop to ip6_input(). */
1035 		if (in6_localip(&ip6->ip6_dst)) {
1036 			m->m_flags |= M_FASTFWD_OURS;
1037 			if (m->m_pkthdr.rcvif == NULL)
1038 				m->m_pkthdr.rcvif = V_loif;
1039 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1040 				m->m_pkthdr.csum_flags |=
1041 				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
1042 				m->m_pkthdr.csum_data = 0xffff;
1043 			}
1044 #if defined(SCTP) || defined(SCTP_SUPPORT)
1045 			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
1046 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
1047 #endif
1048 			error = netisr_queue(NETISR_IPV6, m);
1049 			goto done;
1050 		} else {
1051 			if (ro != NULL)
1052 				RO_INVALIDATE_CACHE(ro);
1053 			needfiblookup = 1; /* Redo the routing table lookup. */
1054 		}
1055 	}
1056 	/* See if fib was changed by packet filter. */
1057 	if (fibnum != M_GETFIB(m)) {
1058 		m->m_flags |= M_SKIP_FIREWALL;
1059 		fibnum = M_GETFIB(m);
1060 		if (ro != NULL)
1061 			RO_INVALIDATE_CACHE(ro);
1062 		needfiblookup = 1;
1063 	}
1064 	if (needfiblookup)
1065 		goto again;
1066 
1067 	/* See if local, if yes, send it to netisr. */
1068 	if (m->m_flags & M_FASTFWD_OURS) {
1069 		if (m->m_pkthdr.rcvif == NULL)
1070 			m->m_pkthdr.rcvif = V_loif;
1071 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1072 			m->m_pkthdr.csum_flags |=
1073 			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
1074 			m->m_pkthdr.csum_data = 0xffff;
1075 		}
1076 #if defined(SCTP) || defined(SCTP_SUPPORT)
1077 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
1078 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
1079 #endif
1080 		error = netisr_queue(NETISR_IPV6, m);
1081 		goto done;
1082 	}
1083 	/* Or forward to some other address? */
1084 	if ((m->m_flags & M_IP6_NEXTHOP) &&
1085 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
1086 		if (ro != NULL)
1087 			dst = (struct sockaddr_in6 *)&ro->ro_dst;
1088 		else
1089 			dst = &sin6;
1090 		bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
1091 		m->m_flags |= M_SKIP_FIREWALL;
1092 		m->m_flags &= ~M_IP6_NEXTHOP;
1093 		m_tag_delete(m, fwd_tag);
1094 		goto again;
1095 	}
1096 
1097 passout:
1098 	if (vlan_pcp > -1)
1099 		EVL_APPLY_PRI(m, vlan_pcp);
1100 
1101 	/* Ensure the packet data is mapped if the interface requires it. */
1102 	if ((ifp->if_capenable & IFCAP_MEXTPG) == 0) {
1103 		struct mbuf *m1;
1104 
1105 		error = mb_unmapped_to_ext(m, &m1);
1106 		if (error != 0) {
1107 			if (error == EINVAL) {
1108 				if_printf(ifp, "TLS packet\n");
1109 				/* XXXKIB */
1110 			} else if (error == ENOMEM) {
1111 				error = ENOBUFS;
1112 			}
1113 			IP6STAT_INC(ip6s_odropped);
1114 			return (error);
1115 		} else {
1116 			m = m1;
1117 		}
1118 	}
1119 
1120 	/*
1121 	 * Send the packet to the outgoing interface.
1122 	 * If necessary, do IPv6 fragmentation before sending.
1123 	 *
1124 	 * The logic here is rather complex:
1125 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
1126 	 * 1-a:	send as is if tlen <= path mtu
1127 	 * 1-b:	fragment if tlen > path mtu
1128 	 *
1129 	 * 2: if user asks us not to fragment (dontfrag == 1)
1130 	 * 2-a:	send as is if tlen <= interface mtu
1131 	 * 2-b:	error if tlen > interface mtu
1132 	 *
1133 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
1134 	 *	always fragment
1135 	 *
1136 	 * 4: if dontfrag == 1 && alwaysfrag == 1
1137 	 *	error, as we cannot handle this conflicting request.
1138 	 */
1139 	sw_csum = m->m_pkthdr.csum_flags;
1140 	if (!hdrsplit) {
1141 		tso = ((sw_csum & ifp->if_hwassist &
1142 		    (CSUM_TSO | CSUM_INNER_TSO)) != 0) ? 1 : 0;
1143 		sw_csum &= ~ifp->if_hwassist;
1144 	} else
1145 		tso = 0;
1146 	/*
1147 	 * If we added extension headers, we will not do TSO and calculate the
1148 	 * checksums ourselves for now.
1149 	 * XXX-BZ  Need a framework to know when the NIC can handle it, even
1150 	 * with ext. hdrs.
1151 	 */
1152 	ip6_output_delayed_csum(m, ifp, sw_csum, plen, optlen);
1153 	/* XXX-BZ m->m_pkthdr.csum_flags &= ~ifp->if_hwassist; */
1154 	tlen = m->m_pkthdr.len;
1155 
1156 	if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
1157 		dontfrag = 1;
1158 	else
1159 		dontfrag = 0;
1160 	if (dontfrag && alwaysfrag) {	/* Case 4. */
1161 		/* Conflicting request - can't transmit. */
1162 		error = EMSGSIZE;
1163 		goto bad;
1164 	}
1165 	if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {	/* Case 2-b. */
1166 		/*
1167 		 * Even if the DONTFRAG option is specified, we cannot send the
1168 		 * packet when the data length is larger than the MTU of the
1169 		 * outgoing interface.
1170 		 * Notify the error by sending IPV6_PATHMTU ancillary data if
1171 		 * application wanted to know the MTU value. Also return an
1172 		 * error code (this is not described in the API spec).
1173 		 */
1174 		if (inp != NULL)
1175 			ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
1176 		error = EMSGSIZE;
1177 		goto bad;
1178 	}
1179 
1180 	/* Transmit packet without fragmentation. */
1181 	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* Cases 1-a and 2-a. */
1182 		struct in6_ifaddr *ia6;
1183 
1184 		ip6 = mtod(m, struct ip6_hdr *);
1185 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
1186 		if (ia6) {
1187 			/* Record statistics for this interface address. */
1188 			counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
1189 			counter_u64_add(ia6->ia_ifa.ifa_obytes,
1190 			    m->m_pkthdr.len);
1191 		}
1192 		error = ip6_output_send(inp, ifp, origifp, m, dst, ro,
1193 		    (flags & IP_NO_SND_TAG_RL) ? false : true);
1194 		goto done;
1195 	}
1196 
1197 	/* Try to fragment the packet.  Cases 1-b and 3. */
1198 	if (mtu < IPV6_MMTU) {
1199 		/* Path MTU cannot be less than IPV6_MMTU. */
1200 		error = EMSGSIZE;
1201 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
1202 		goto bad;
1203 	} else if (ip6->ip6_plen == 0) {
1204 		/* Jumbo payload cannot be fragmented. */
1205 		error = EMSGSIZE;
1206 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
1207 		goto bad;
1208 	} else {
1209 		u_char nextproto;
1210 
1211 		/*
1212 		 * Too large for the destination or interface;
1213 		 * fragment if possible.
1214 		 * Must be able to put at least 8 bytes per fragment.
1215 		 */
1216 		if (mtu > IPV6_MAXPACKET)
1217 			mtu = IPV6_MAXPACKET;
1218 
1219 		len = (mtu - unfragpartlen - sizeof(struct ip6_frag)) & ~7;
1220 		if (len < 8) {
1221 			error = EMSGSIZE;
1222 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
1223 			goto bad;
1224 		}
1225 
1226 		/*
1227 		 * If the interface will not calculate checksums on
1228 		 * fragmented packets, then do it here.
1229 		 * XXX-BZ handle the hw offloading case.  Need flags.
1230 		 */
1231 		ip6_output_delayed_csum(m, ifp, m->m_pkthdr.csum_flags, plen,
1232 		    optlen);
1233 
1234 		/*
1235 		 * Change the next header field of the last header in the
1236 		 * unfragmentable part.
1237 		 */
1238 		if (exthdrs.ip6e_rthdr) {
1239 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1240 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1241 		} else if (exthdrs.ip6e_dest1) {
1242 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1243 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1244 		} else if (exthdrs.ip6e_hbh) {
1245 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1246 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1247 		} else {
1248 			ip6 = mtod(m, struct ip6_hdr *);
1249 			nextproto = ip6->ip6_nxt;
1250 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
1251 		}
1252 
1253 		/*
1254 		 * Loop through length of segment after first fragment,
1255 		 * make new header and copy data of each part and link onto
1256 		 * chain.
1257 		 */
1258 		m0 = m;
1259 		id = htonl(ip6_randomid());
1260 		error = ip6_fragment(ifp, m, unfragpartlen, nextproto,len, id);
1261 		if (error != 0)
1262 			goto sendorfree;
1263 
1264 		in6_ifstat_inc(ifp, ifs6_out_fragok);
1265 	}
1266 
1267 	/* Remove leading garbage. */
1268 sendorfree:
1269 	m = m0->m_nextpkt;
1270 	m0->m_nextpkt = 0;
1271 	m_freem(m0);
1272 	for (; m; m = m0) {
1273 		m0 = m->m_nextpkt;
1274 		m->m_nextpkt = 0;
1275 		if (error == 0) {
1276 			/* Record statistics for this interface address. */
1277 			if (ia) {
1278 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1279 				counter_u64_add(ia->ia_ifa.ifa_obytes,
1280 				    m->m_pkthdr.len);
1281 			}
1282 			if (vlan_pcp > -1)
1283 				EVL_APPLY_PRI(m, vlan_pcp);
1284 			error = ip6_output_send(inp, ifp, origifp, m, dst, ro,
1285 			    true);
1286 		} else
1287 			m_freem(m);
1288 	}
1289 
1290 	if (error == 0)
1291 		IP6STAT_INC(ip6s_fragmented);
1292 
1293 done:
1294 	return (error);
1295 
1296 freehdrs:
1297 	m_freem(exthdrs.ip6e_hbh);	/* m_freem() checks if mbuf is NULL. */
1298 	m_freem(exthdrs.ip6e_dest1);
1299 	m_freem(exthdrs.ip6e_rthdr);
1300 	m_freem(exthdrs.ip6e_dest2);
1301 	/* FALLTHROUGH */
1302 bad:
1303 	if (m)
1304 		m_freem(m);
1305 	goto done;
1306 }
1307 
1308 static int
ip6_copyexthdr(struct mbuf ** mp,caddr_t hdr,int hlen)1309 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1310 {
1311 	struct mbuf *m;
1312 
1313 	if (hlen > MCLBYTES)
1314 		return (ENOBUFS); /* XXX */
1315 
1316 	if (hlen > MLEN)
1317 		m = m_getcl(M_NOWAIT, MT_DATA, 0);
1318 	else
1319 		m = m_get(M_NOWAIT, MT_DATA);
1320 	if (m == NULL)
1321 		return (ENOBUFS);
1322 	m->m_len = hlen;
1323 	if (hdr)
1324 		bcopy(hdr, mtod(m, caddr_t), hlen);
1325 
1326 	*mp = m;
1327 	return (0);
1328 }
1329 
1330 /*
1331  * Insert jumbo payload option.
1332  */
1333 static int
ip6_insert_jumboopt(struct ip6_exthdrs * exthdrs,u_int32_t plen)1334 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1335 {
1336 	struct mbuf *mopt;
1337 	u_char *optbuf;
1338 	u_int32_t v;
1339 
1340 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1341 
1342 	/*
1343 	 * If there is no hop-by-hop options header, allocate new one.
1344 	 * If there is one but it doesn't have enough space to store the
1345 	 * jumbo payload option, allocate a cluster to store the whole options.
1346 	 * Otherwise, use it to store the options.
1347 	 */
1348 	if (exthdrs->ip6e_hbh == NULL) {
1349 		mopt = m_get(M_NOWAIT, MT_DATA);
1350 		if (mopt == NULL)
1351 			return (ENOBUFS);
1352 		mopt->m_len = JUMBOOPTLEN;
1353 		optbuf = mtod(mopt, u_char *);
1354 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1355 		exthdrs->ip6e_hbh = mopt;
1356 	} else {
1357 		struct ip6_hbh *hbh;
1358 
1359 		mopt = exthdrs->ip6e_hbh;
1360 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1361 			/*
1362 			 * XXX assumption:
1363 			 * - exthdrs->ip6e_hbh is not referenced from places
1364 			 *   other than exthdrs.
1365 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1366 			 */
1367 			int oldoptlen = mopt->m_len;
1368 			struct mbuf *n;
1369 
1370 			/*
1371 			 * XXX: give up if the whole (new) hbh header does
1372 			 * not fit even in an mbuf cluster.
1373 			 */
1374 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1375 				return (ENOBUFS);
1376 
1377 			/*
1378 			 * As a consequence, we must always prepare a cluster
1379 			 * at this point.
1380 			 */
1381 			n = m_getcl(M_NOWAIT, MT_DATA, 0);
1382 			if (n == NULL)
1383 				return (ENOBUFS);
1384 			n->m_len = oldoptlen + JUMBOOPTLEN;
1385 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1386 			    oldoptlen);
1387 			optbuf = mtod(n, caddr_t) + oldoptlen;
1388 			m_freem(mopt);
1389 			mopt = exthdrs->ip6e_hbh = n;
1390 		} else {
1391 			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1392 			mopt->m_len += JUMBOOPTLEN;
1393 		}
1394 		optbuf[0] = IP6OPT_PADN;
1395 		optbuf[1] = 1;
1396 
1397 		/*
1398 		 * Adjust the header length according to the pad and
1399 		 * the jumbo payload option.
1400 		 */
1401 		hbh = mtod(mopt, struct ip6_hbh *);
1402 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1403 	}
1404 
1405 	/* fill in the option. */
1406 	optbuf[2] = IP6OPT_JUMBO;
1407 	optbuf[3] = 4;
1408 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1409 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1410 
1411 	/* finally, adjust the packet header length */
1412 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1413 
1414 	return (0);
1415 #undef JUMBOOPTLEN
1416 }
1417 
1418 /*
1419  * Insert fragment header and copy unfragmentable header portions.
1420  */
1421 static int
ip6_insertfraghdr(struct mbuf * m0,struct mbuf * m,int hlen,struct ip6_frag ** frghdrp)1422 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1423     struct ip6_frag **frghdrp)
1424 {
1425 	struct mbuf *n, *mlast;
1426 
1427 	if (hlen > sizeof(struct ip6_hdr)) {
1428 		n = m_copym(m0, sizeof(struct ip6_hdr),
1429 		    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1430 		if (n == NULL)
1431 			return (ENOBUFS);
1432 		m->m_next = n;
1433 	} else
1434 		n = m;
1435 
1436 	/* Search for the last mbuf of unfragmentable part. */
1437 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1438 		;
1439 
1440 	if (M_WRITABLE(mlast) &&
1441 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1442 		/* use the trailing space of the last mbuf for the fragment hdr */
1443 		*frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1444 		    mlast->m_len);
1445 		mlast->m_len += sizeof(struct ip6_frag);
1446 		m->m_pkthdr.len += sizeof(struct ip6_frag);
1447 	} else {
1448 		/* allocate a new mbuf for the fragment header */
1449 		struct mbuf *mfrg;
1450 
1451 		mfrg = m_get(M_NOWAIT, MT_DATA);
1452 		if (mfrg == NULL)
1453 			return (ENOBUFS);
1454 		mfrg->m_len = sizeof(struct ip6_frag);
1455 		*frghdrp = mtod(mfrg, struct ip6_frag *);
1456 		mlast->m_next = mfrg;
1457 	}
1458 
1459 	return (0);
1460 }
1461 
1462 /*
1463  * Calculates IPv6 path mtu for destination @dst.
1464  * Resulting MTU is stored in @mtup.
1465  *
1466  * Returns 0 on success.
1467  */
1468 static int
ip6_getpmtu_ctl(u_int fibnum,const struct in6_addr * dst,u_long * mtup)1469 ip6_getpmtu_ctl(u_int fibnum, const struct in6_addr *dst, u_long *mtup)
1470 {
1471 	struct epoch_tracker et;
1472 	struct nhop_object *nh;
1473 	struct in6_addr kdst;
1474 	uint32_t scopeid;
1475 	int error;
1476 
1477 	in6_splitscope(dst, &kdst, &scopeid);
1478 
1479 	NET_EPOCH_ENTER(et);
1480 	nh = fib6_lookup(fibnum, &kdst, scopeid, NHR_NONE, 0);
1481 	if (nh != NULL)
1482 		error = ip6_calcmtu(nh->nh_ifp, dst, nh->nh_mtu, mtup, NULL, 0);
1483 	else
1484 		error = EHOSTUNREACH;
1485 	NET_EPOCH_EXIT(et);
1486 
1487 	return (error);
1488 }
1489 
1490 /*
1491  * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1492  * and cached data in @ro_pmtu.
1493  * MTU from (successful) route lookup is saved (along with dst)
1494  * inside @ro_pmtu to avoid subsequent route lookups after packet
1495  * filter processing.
1496  *
1497  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1498  * Returns 0 on success.
1499  */
1500 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)1501 ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1502     struct ifnet *ifp, const struct in6_addr *dst, u_long *mtup,
1503     int *alwaysfragp, u_int fibnum, u_int proto)
1504 {
1505 	struct nhop_object *nh;
1506 	struct in6_addr kdst;
1507 	uint32_t scopeid;
1508 	struct sockaddr_in6 *sa6_dst, sin6;
1509 	u_long mtu;
1510 
1511 	NET_EPOCH_ASSERT();
1512 
1513 	mtu = 0;
1514 	if (ro_pmtu == NULL || do_lookup) {
1515 		/*
1516 		 * Here ro_pmtu has final destination address, while
1517 		 * ro might represent immediate destination.
1518 		 * Use ro_pmtu destination since mtu might differ.
1519 		 */
1520 		if (ro_pmtu != NULL) {
1521 			sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1522 			if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1523 				ro_pmtu->ro_mtu = 0;
1524 		} else
1525 			sa6_dst = &sin6;
1526 
1527 		if (ro_pmtu == NULL || ro_pmtu->ro_mtu == 0) {
1528 			bzero(sa6_dst, sizeof(*sa6_dst));
1529 			sa6_dst->sin6_family = AF_INET6;
1530 			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1531 			sa6_dst->sin6_addr = *dst;
1532 
1533 			in6_splitscope(dst, &kdst, &scopeid);
1534 			nh = fib6_lookup(fibnum, &kdst, scopeid, NHR_NONE, 0);
1535 			if (nh != NULL) {
1536 				mtu = nh->nh_mtu;
1537 				if (ro_pmtu != NULL)
1538 					ro_pmtu->ro_mtu = mtu;
1539 			}
1540 		} else
1541 			mtu = ro_pmtu->ro_mtu;
1542 	}
1543 
1544 	if (ro_pmtu != NULL && ro_pmtu->ro_nh != NULL)
1545 		mtu = ro_pmtu->ro_nh->nh_mtu;
1546 
1547 	return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp, proto));
1548 }
1549 
1550 /*
1551  * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1552  * hostcache data for @dst.
1553  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1554  *
1555  * Returns 0 on success.
1556  */
1557 static int
ip6_calcmtu(struct ifnet * ifp,const struct in6_addr * dst,u_long rt_mtu,u_long * mtup,int * alwaysfragp,u_int proto)1558 ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1559     u_long *mtup, int *alwaysfragp, u_int proto)
1560 {
1561 	u_long mtu = 0;
1562 	int alwaysfrag = 0;
1563 	int error = 0;
1564 
1565 	if (rt_mtu > 0) {
1566 		u_int32_t ifmtu;
1567 		struct in_conninfo inc;
1568 
1569 		bzero(&inc, sizeof(inc));
1570 		inc.inc_flags |= INC_ISIPV6;
1571 		inc.inc6_faddr = *dst;
1572 
1573 		ifmtu = IN6_LINKMTU(ifp);
1574 
1575 		/* TCP is known to react to pmtu changes so skip hc */
1576 		if (proto != IPPROTO_TCP)
1577 			mtu = tcp_hc_getmtu(&inc);
1578 
1579 		if (mtu)
1580 			mtu = min(mtu, rt_mtu);
1581 		else
1582 			mtu = rt_mtu;
1583 		if (mtu == 0)
1584 			mtu = ifmtu;
1585 		else if (mtu < IPV6_MMTU) {
1586 			/*
1587 			 * RFC2460 section 5, last paragraph:
1588 			 * if we record ICMPv6 too big message with
1589 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1590 			 * or smaller, with framgent header attached.
1591 			 * (fragment header is needed regardless from the
1592 			 * packet size, for translators to identify packets)
1593 			 */
1594 			alwaysfrag = 1;
1595 			mtu = IPV6_MMTU;
1596 		}
1597 	} else if (ifp) {
1598 		mtu = IN6_LINKMTU(ifp);
1599 	} else
1600 		error = EHOSTUNREACH; /* XXX */
1601 
1602 	*mtup = mtu;
1603 	if (alwaysfragp)
1604 		*alwaysfragp = alwaysfrag;
1605 	return (error);
1606 }
1607 
1608 /*
1609  * IP6 socket option processing.
1610  */
1611 int
ip6_ctloutput(struct socket * so,struct sockopt * sopt)1612 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1613 {
1614 	int optdatalen, uproto;
1615 	void *optdata;
1616 	struct inpcb *inp = sotoinpcb(so);
1617 	int error, optval;
1618 	int level, op, optname;
1619 	int optlen;
1620 	struct thread *td;
1621 #ifdef	RSS
1622 	uint32_t rss_bucket;
1623 	int retval;
1624 #endif
1625 
1626 /*
1627  * Don't use more than a quarter of mbuf clusters.  N.B.:
1628  * nmbclusters is an int, but nmbclusters * MCLBYTES may overflow
1629  * on LP64 architectures, so cast to u_long to avoid undefined
1630  * behavior.  ILP32 architectures cannot have nmbclusters
1631  * large enough to overflow for other reasons.
1632  */
1633 #define IPV6_PKTOPTIONS_MBUF_LIMIT	((u_long)nmbclusters * MCLBYTES / 4)
1634 
1635 	level = sopt->sopt_level;
1636 	op = sopt->sopt_dir;
1637 	optname = sopt->sopt_name;
1638 	optlen = sopt->sopt_valsize;
1639 	td = sopt->sopt_td;
1640 	error = 0;
1641 	optval = 0;
1642 	uproto = (int)so->so_proto->pr_protocol;
1643 
1644 	if (level != IPPROTO_IPV6) {
1645 		error = EINVAL;
1646 
1647 		if (sopt->sopt_level == SOL_SOCKET &&
1648 		    sopt->sopt_dir == SOPT_SET) {
1649 			switch (sopt->sopt_name) {
1650 			case SO_SETFIB:
1651 				error = sooptcopyin(sopt, &optval,
1652 				    sizeof(optval), sizeof(optval));
1653 				if (error != 0)
1654 					break;
1655 
1656 				INP_WLOCK(inp);
1657 				if ((inp->inp_flags & INP_BOUNDFIB) != 0 &&
1658 				    optval != so->so_fibnum) {
1659 					INP_WUNLOCK(inp);
1660 					error = EISCONN;
1661 					break;
1662 				}
1663 				error = sosetfib(inp->inp_socket, optval);
1664 				if (error == 0)
1665 					inp->inp_inc.inc_fibnum = optval;
1666 				INP_WUNLOCK(inp);
1667 				break;
1668 			case SO_MAX_PACING_RATE:
1669 #ifdef RATELIMIT
1670 				INP_WLOCK(inp);
1671 				inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1672 				INP_WUNLOCK(inp);
1673 				error = 0;
1674 #else
1675 				error = EOPNOTSUPP;
1676 #endif
1677 				break;
1678 			default:
1679 				break;
1680 			}
1681 		}
1682 	} else {		/* level == IPPROTO_IPV6 */
1683 		switch (op) {
1684 		case SOPT_SET:
1685 			switch (optname) {
1686 			case IPV6_2292PKTOPTIONS:
1687 #ifdef IPV6_PKTOPTIONS
1688 			case IPV6_PKTOPTIONS:
1689 #endif
1690 			{
1691 				struct mbuf *m;
1692 
1693 				if (optlen > IPV6_PKTOPTIONS_MBUF_LIMIT) {
1694 					printf("ip6_ctloutput: mbuf limit hit\n");
1695 					error = ENOBUFS;
1696 					break;
1697 				}
1698 
1699 				error = soopt_getm(sopt, &m); /* XXX */
1700 				if (error != 0)
1701 					break;
1702 				error = soopt_mcopyin(sopt, m); /* XXX */
1703 				if (error != 0)
1704 					break;
1705 				INP_WLOCK(inp);
1706 				error = ip6_pcbopts(&inp->in6p_outputopts, m,
1707 				    so, sopt);
1708 				INP_WUNLOCK(inp);
1709 				m_freem(m); /* XXX */
1710 				break;
1711 			}
1712 
1713 			/*
1714 			 * Use of some Hop-by-Hop options or some
1715 			 * Destination options, might require special
1716 			 * privilege.  That is, normal applications
1717 			 * (without special privilege) might be forbidden
1718 			 * from setting certain options in outgoing packets,
1719 			 * and might never see certain options in received
1720 			 * packets. [RFC 2292 Section 6]
1721 			 * KAME specific note:
1722 			 *  KAME prevents non-privileged users from sending or
1723 			 *  receiving ANY hbh/dst options in order to avoid
1724 			 *  overhead of parsing options in the kernel.
1725 			 */
1726 			case IPV6_RECVHOPOPTS:
1727 			case IPV6_RECVDSTOPTS:
1728 			case IPV6_RECVRTHDRDSTOPTS:
1729 				if (td != NULL) {
1730 					error = priv_check(td,
1731 					    PRIV_NETINET_SETHDROPTS);
1732 					if (error)
1733 						break;
1734 				}
1735 				/* FALLTHROUGH */
1736 			case IPV6_UNICAST_HOPS:
1737 			case IPV6_HOPLIMIT:
1738 
1739 			case IPV6_RECVPKTINFO:
1740 			case IPV6_RECVHOPLIMIT:
1741 			case IPV6_RECVRTHDR:
1742 			case IPV6_RECVPATHMTU:
1743 			case IPV6_RECVTCLASS:
1744 			case IPV6_RECVFLOWID:
1745 #ifdef	RSS
1746 			case IPV6_RECVRSSBUCKETID:
1747 #endif
1748 			case IPV6_V6ONLY:
1749 			case IPV6_AUTOFLOWLABEL:
1750 			case IPV6_ORIGDSTADDR:
1751 			case IPV6_BINDANY:
1752 			case IPV6_VLAN_PCP:
1753 				if (optname == IPV6_BINDANY && td != NULL) {
1754 					error = priv_check(td,
1755 					    PRIV_NETINET_BINDANY);
1756 					if (error)
1757 						break;
1758 				}
1759 
1760 				if (optlen != sizeof(int)) {
1761 					error = EINVAL;
1762 					break;
1763 				}
1764 				error = sooptcopyin(sopt, &optval,
1765 					sizeof optval, sizeof optval);
1766 				if (error)
1767 					break;
1768 				switch (optname) {
1769 				case IPV6_UNICAST_HOPS:
1770 					if (optval < -1 || optval >= 256)
1771 						error = EINVAL;
1772 					else {
1773 						/* -1 = kernel default */
1774 						inp->in6p_hops = optval;
1775 						if ((inp->inp_vflag &
1776 						     INP_IPV4) != 0)
1777 							inp->inp_ip_ttl = optval;
1778 					}
1779 					break;
1780 #define OPTSET(bit) \
1781 do { \
1782 	INP_WLOCK(inp); \
1783 	if (optval) \
1784 		inp->inp_flags |= (bit); \
1785 	else \
1786 		inp->inp_flags &= ~(bit); \
1787 	INP_WUNLOCK(inp); \
1788 } while (/*CONSTCOND*/ 0)
1789 #define OPTSET2292(bit) \
1790 do { \
1791 	INP_WLOCK(inp); \
1792 	inp->inp_flags |= IN6P_RFC2292; \
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 OPTBIT(bit) (inp->inp_flags & (bit) ? 1 : 0)
1800 
1801 #define OPTSET2_N(bit, val) do {					\
1802 	if (val)							\
1803 		inp->inp_flags2 |= bit;					\
1804 	else								\
1805 		inp->inp_flags2 &= ~bit;				\
1806 } while (0)
1807 #define OPTSET2(bit, val) do {						\
1808 	INP_WLOCK(inp);							\
1809 	OPTSET2_N(bit, val);						\
1810 	INP_WUNLOCK(inp);						\
1811 } while (0)
1812 #define OPTBIT2(bit) (inp->inp_flags2 & (bit) ? 1 : 0)
1813 #define OPTSET2292_EXCLUSIVE(bit)					\
1814 do {									\
1815 	INP_WLOCK(inp);							\
1816 	if (OPTBIT(IN6P_RFC2292)) {					\
1817 		error = EINVAL;						\
1818 	} else {							\
1819 		if (optval)						\
1820 			inp->inp_flags |= (bit);			\
1821 		else							\
1822 			inp->inp_flags &= ~(bit);			\
1823 	}								\
1824 	INP_WUNLOCK(inp);						\
1825 } while (/*CONSTCOND*/ 0)
1826 
1827 				case IPV6_RECVPKTINFO:
1828 					OPTSET2292_EXCLUSIVE(IN6P_PKTINFO);
1829 					break;
1830 
1831 				case IPV6_HOPLIMIT:
1832 				{
1833 					struct ip6_pktopts **optp;
1834 
1835 					/* cannot mix with RFC2292 */
1836 					if (OPTBIT(IN6P_RFC2292)) {
1837 						error = EINVAL;
1838 						break;
1839 					}
1840 					INP_WLOCK(inp);
1841 					if (inp->inp_flags & INP_DROPPED) {
1842 						INP_WUNLOCK(inp);
1843 						return (ECONNRESET);
1844 					}
1845 					optp = &inp->in6p_outputopts;
1846 					error = ip6_pcbopt(IPV6_HOPLIMIT,
1847 					    (u_char *)&optval, sizeof(optval),
1848 					    optp, (td != NULL) ? td->td_ucred :
1849 					    NULL, uproto);
1850 					INP_WUNLOCK(inp);
1851 					break;
1852 				}
1853 
1854 				case IPV6_RECVHOPLIMIT:
1855 					OPTSET2292_EXCLUSIVE(IN6P_HOPLIMIT);
1856 					break;
1857 
1858 				case IPV6_RECVHOPOPTS:
1859 					OPTSET2292_EXCLUSIVE(IN6P_HOPOPTS);
1860 					break;
1861 
1862 				case IPV6_RECVDSTOPTS:
1863 					OPTSET2292_EXCLUSIVE(IN6P_DSTOPTS);
1864 					break;
1865 
1866 				case IPV6_RECVRTHDRDSTOPTS:
1867 					OPTSET2292_EXCLUSIVE(IN6P_RTHDRDSTOPTS);
1868 					break;
1869 
1870 				case IPV6_RECVRTHDR:
1871 					OPTSET2292_EXCLUSIVE(IN6P_RTHDR);
1872 					break;
1873 
1874 				case IPV6_RECVPATHMTU:
1875 					/*
1876 					 * We ignore this option for TCP
1877 					 * sockets.
1878 					 * (RFC3542 leaves this case
1879 					 * unspecified.)
1880 					 */
1881 					if (uproto != IPPROTO_TCP)
1882 						OPTSET(IN6P_MTU);
1883 					break;
1884 
1885 				case IPV6_RECVFLOWID:
1886 					OPTSET2(INP_RECVFLOWID, optval);
1887 					break;
1888 
1889 #ifdef	RSS
1890 				case IPV6_RECVRSSBUCKETID:
1891 					OPTSET2(INP_RECVRSSBUCKETID, optval);
1892 					break;
1893 #endif
1894 
1895 				case IPV6_V6ONLY:
1896 					INP_WLOCK(inp);
1897 					if (inp->inp_lport ||
1898 					    !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
1899 						/*
1900 						 * The socket is already bound.
1901 						 */
1902 						INP_WUNLOCK(inp);
1903 						error = EINVAL;
1904 						break;
1905 					}
1906 					if (optval) {
1907 						inp->inp_flags |= IN6P_IPV6_V6ONLY;
1908 						inp->inp_vflag &= ~INP_IPV4;
1909 					} else {
1910 						inp->inp_flags &= ~IN6P_IPV6_V6ONLY;
1911 						inp->inp_vflag |= INP_IPV4;
1912 					}
1913 					INP_WUNLOCK(inp);
1914 					break;
1915 				case IPV6_RECVTCLASS:
1916 					/* cannot mix with RFC2292 XXX */
1917 					OPTSET2292_EXCLUSIVE(IN6P_TCLASS);
1918 					break;
1919 				case IPV6_AUTOFLOWLABEL:
1920 					OPTSET(IN6P_AUTOFLOWLABEL);
1921 					break;
1922 
1923 				case IPV6_ORIGDSTADDR:
1924 					OPTSET2(INP_ORIGDSTADDR, optval);
1925 					break;
1926 				case IPV6_BINDANY:
1927 					OPTSET(INP_BINDANY);
1928 					break;
1929 				case IPV6_VLAN_PCP:
1930 					if ((optval >= -1) && (optval <=
1931 					    (INP_2PCP_MASK >> INP_2PCP_SHIFT))) {
1932 						if (optval == -1) {
1933 							INP_WLOCK(inp);
1934 							inp->inp_flags2 &=
1935 							    ~(INP_2PCP_SET |
1936 							    INP_2PCP_MASK);
1937 							INP_WUNLOCK(inp);
1938 						} else {
1939 							INP_WLOCK(inp);
1940 							inp->inp_flags2 |=
1941 							    INP_2PCP_SET;
1942 							inp->inp_flags2 &=
1943 							    ~INP_2PCP_MASK;
1944 							inp->inp_flags2 |=
1945 							    optval <<
1946 							    INP_2PCP_SHIFT;
1947 							INP_WUNLOCK(inp);
1948 						}
1949 					} else
1950 						error = EINVAL;
1951 					break;
1952 				}
1953 				break;
1954 
1955 			case IPV6_TCLASS:
1956 			case IPV6_DONTFRAG:
1957 			case IPV6_USE_MIN_MTU:
1958 			case IPV6_PREFER_TEMPADDR:
1959 				if (optlen != sizeof(optval)) {
1960 					error = EINVAL;
1961 					break;
1962 				}
1963 				error = sooptcopyin(sopt, &optval,
1964 					sizeof optval, sizeof optval);
1965 				if (error)
1966 					break;
1967 				{
1968 					struct ip6_pktopts **optp;
1969 					INP_WLOCK(inp);
1970 					if (inp->inp_flags & INP_DROPPED) {
1971 						INP_WUNLOCK(inp);
1972 						return (ECONNRESET);
1973 					}
1974 					optp = &inp->in6p_outputopts;
1975 					error = ip6_pcbopt(optname,
1976 					    (u_char *)&optval, sizeof(optval),
1977 					    optp, (td != NULL) ? td->td_ucred :
1978 					    NULL, uproto);
1979 					INP_WUNLOCK(inp);
1980 					break;
1981 				}
1982 
1983 			case IPV6_2292PKTINFO:
1984 			case IPV6_2292HOPLIMIT:
1985 			case IPV6_2292HOPOPTS:
1986 			case IPV6_2292DSTOPTS:
1987 			case IPV6_2292RTHDR:
1988 				/* RFC 2292 */
1989 				if (optlen != sizeof(int)) {
1990 					error = EINVAL;
1991 					break;
1992 				}
1993 				error = sooptcopyin(sopt, &optval,
1994 					sizeof optval, sizeof optval);
1995 				if (error)
1996 					break;
1997 				switch (optname) {
1998 				case IPV6_2292PKTINFO:
1999 					OPTSET2292(IN6P_PKTINFO);
2000 					break;
2001 				case IPV6_2292HOPLIMIT:
2002 					OPTSET2292(IN6P_HOPLIMIT);
2003 					break;
2004 				case IPV6_2292HOPOPTS:
2005 					/*
2006 					 * Check super-user privilege.
2007 					 * See comments for IPV6_RECVHOPOPTS.
2008 					 */
2009 					if (td != NULL) {
2010 						error = priv_check(td,
2011 						    PRIV_NETINET_SETHDROPTS);
2012 						if (error)
2013 							return (error);
2014 					}
2015 					OPTSET2292(IN6P_HOPOPTS);
2016 					break;
2017 				case IPV6_2292DSTOPTS:
2018 					if (td != NULL) {
2019 						error = priv_check(td,
2020 						    PRIV_NETINET_SETHDROPTS);
2021 						if (error)
2022 							return (error);
2023 					}
2024 					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
2025 					break;
2026 				case IPV6_2292RTHDR:
2027 					OPTSET2292(IN6P_RTHDR);
2028 					break;
2029 				}
2030 				break;
2031 			case IPV6_PKTINFO:
2032 			case IPV6_HOPOPTS:
2033 			case IPV6_RTHDR:
2034 			case IPV6_DSTOPTS:
2035 			case IPV6_RTHDRDSTOPTS:
2036 			case IPV6_NEXTHOP:
2037 			{
2038 				/* new advanced API (RFC3542) */
2039 				u_char *optbuf;
2040 				u_char optbuf_storage[MCLBYTES];
2041 				int optlen;
2042 				struct ip6_pktopts **optp;
2043 
2044 				/* cannot mix with RFC2292 */
2045 				if (OPTBIT(IN6P_RFC2292)) {
2046 					error = EINVAL;
2047 					break;
2048 				}
2049 
2050 				/*
2051 				 * We only ensure valsize is not too large
2052 				 * here.  Further validation will be done
2053 				 * later.
2054 				 */
2055 				error = sooptcopyin(sopt, optbuf_storage,
2056 				    sizeof(optbuf_storage), 0);
2057 				if (error)
2058 					break;
2059 				optlen = sopt->sopt_valsize;
2060 				optbuf = optbuf_storage;
2061 				INP_WLOCK(inp);
2062 				if (inp->inp_flags & INP_DROPPED) {
2063 					INP_WUNLOCK(inp);
2064 					return (ECONNRESET);
2065 				}
2066 				optp = &inp->in6p_outputopts;
2067 				error = ip6_pcbopt(optname, optbuf, optlen,
2068 				    optp, (td != NULL) ? td->td_ucred : NULL,
2069 				    uproto);
2070 				INP_WUNLOCK(inp);
2071 				break;
2072 			}
2073 #undef OPTSET
2074 
2075 			case IPV6_MULTICAST_IF:
2076 			case IPV6_MULTICAST_HOPS:
2077 			case IPV6_MULTICAST_LOOP:
2078 			case IPV6_JOIN_GROUP:
2079 			case IPV6_LEAVE_GROUP:
2080 			case IPV6_MSFILTER:
2081 			case MCAST_BLOCK_SOURCE:
2082 			case MCAST_UNBLOCK_SOURCE:
2083 			case MCAST_JOIN_GROUP:
2084 			case MCAST_LEAVE_GROUP:
2085 			case MCAST_JOIN_SOURCE_GROUP:
2086 			case MCAST_LEAVE_SOURCE_GROUP:
2087 				error = ip6_setmoptions(inp, sopt);
2088 				break;
2089 
2090 			case IPV6_PORTRANGE:
2091 				error = sooptcopyin(sopt, &optval,
2092 				    sizeof optval, sizeof optval);
2093 				if (error)
2094 					break;
2095 
2096 				INP_WLOCK(inp);
2097 				switch (optval) {
2098 				case IPV6_PORTRANGE_DEFAULT:
2099 					inp->inp_flags &= ~(INP_LOWPORT);
2100 					inp->inp_flags &= ~(INP_HIGHPORT);
2101 					break;
2102 
2103 				case IPV6_PORTRANGE_HIGH:
2104 					inp->inp_flags &= ~(INP_LOWPORT);
2105 					inp->inp_flags |= INP_HIGHPORT;
2106 					break;
2107 
2108 				case IPV6_PORTRANGE_LOW:
2109 					inp->inp_flags &= ~(INP_HIGHPORT);
2110 					inp->inp_flags |= INP_LOWPORT;
2111 					break;
2112 
2113 				default:
2114 					error = EINVAL;
2115 					break;
2116 				}
2117 				INP_WUNLOCK(inp);
2118 				break;
2119 
2120 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
2121 			case IPV6_IPSEC_POLICY:
2122 				if (IPSEC_ENABLED(ipv6)) {
2123 					error = IPSEC_PCBCTL(ipv6, inp, sopt);
2124 					break;
2125 				}
2126 				/* FALLTHROUGH */
2127 #endif /* IPSEC */
2128 
2129 			default:
2130 				error = ENOPROTOOPT;
2131 				break;
2132 			}
2133 			break;
2134 
2135 		case SOPT_GET:
2136 			switch (optname) {
2137 			case IPV6_2292PKTOPTIONS:
2138 #ifdef IPV6_PKTOPTIONS
2139 			case IPV6_PKTOPTIONS:
2140 #endif
2141 				/*
2142 				 * RFC3542 (effectively) deprecated the
2143 				 * semantics of the 2292-style pktoptions.
2144 				 * Since it was not reliable in nature (i.e.,
2145 				 * applications had to expect the lack of some
2146 				 * information after all), it would make sense
2147 				 * to simplify this part by always returning
2148 				 * empty data.
2149 				 */
2150 				sopt->sopt_valsize = 0;
2151 				break;
2152 
2153 			case IPV6_RECVHOPOPTS:
2154 			case IPV6_RECVDSTOPTS:
2155 			case IPV6_RECVRTHDRDSTOPTS:
2156 			case IPV6_UNICAST_HOPS:
2157 			case IPV6_RECVPKTINFO:
2158 			case IPV6_RECVHOPLIMIT:
2159 			case IPV6_RECVRTHDR:
2160 			case IPV6_RECVPATHMTU:
2161 
2162 			case IPV6_V6ONLY:
2163 			case IPV6_PORTRANGE:
2164 			case IPV6_RECVTCLASS:
2165 			case IPV6_AUTOFLOWLABEL:
2166 			case IPV6_BINDANY:
2167 			case IPV6_FLOWID:
2168 			case IPV6_FLOWTYPE:
2169 			case IPV6_RECVFLOWID:
2170 #ifdef	RSS
2171 			case IPV6_RSSBUCKETID:
2172 			case IPV6_RECVRSSBUCKETID:
2173 #endif
2174 			case IPV6_VLAN_PCP:
2175 				switch (optname) {
2176 				case IPV6_RECVHOPOPTS:
2177 					optval = OPTBIT(IN6P_HOPOPTS);
2178 					break;
2179 
2180 				case IPV6_RECVDSTOPTS:
2181 					optval = OPTBIT(IN6P_DSTOPTS);
2182 					break;
2183 
2184 				case IPV6_RECVRTHDRDSTOPTS:
2185 					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
2186 					break;
2187 
2188 				case IPV6_UNICAST_HOPS:
2189 					optval = inp->in6p_hops;
2190 					break;
2191 
2192 				case IPV6_RECVPKTINFO:
2193 					optval = OPTBIT(IN6P_PKTINFO);
2194 					break;
2195 
2196 				case IPV6_RECVHOPLIMIT:
2197 					optval = OPTBIT(IN6P_HOPLIMIT);
2198 					break;
2199 
2200 				case IPV6_RECVRTHDR:
2201 					optval = OPTBIT(IN6P_RTHDR);
2202 					break;
2203 
2204 				case IPV6_RECVPATHMTU:
2205 					optval = OPTBIT(IN6P_MTU);
2206 					break;
2207 
2208 				case IPV6_V6ONLY:
2209 					optval = OPTBIT(IN6P_IPV6_V6ONLY);
2210 					break;
2211 
2212 				case IPV6_PORTRANGE:
2213 				    {
2214 					int flags;
2215 					flags = inp->inp_flags;
2216 					if (flags & INP_HIGHPORT)
2217 						optval = IPV6_PORTRANGE_HIGH;
2218 					else if (flags & INP_LOWPORT)
2219 						optval = IPV6_PORTRANGE_LOW;
2220 					else
2221 						optval = 0;
2222 					break;
2223 				    }
2224 				case IPV6_RECVTCLASS:
2225 					optval = OPTBIT(IN6P_TCLASS);
2226 					break;
2227 
2228 				case IPV6_AUTOFLOWLABEL:
2229 					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2230 					break;
2231 
2232 				case IPV6_ORIGDSTADDR:
2233 					optval = OPTBIT2(INP_ORIGDSTADDR);
2234 					break;
2235 
2236 				case IPV6_BINDANY:
2237 					optval = OPTBIT(INP_BINDANY);
2238 					break;
2239 
2240 				case IPV6_FLOWID:
2241 					optval = inp->inp_flowid;
2242 					break;
2243 
2244 				case IPV6_FLOWTYPE:
2245 					optval = inp->inp_flowtype;
2246 					break;
2247 
2248 				case IPV6_RECVFLOWID:
2249 					optval = OPTBIT2(INP_RECVFLOWID);
2250 					break;
2251 #ifdef	RSS
2252 				case IPV6_RSSBUCKETID:
2253 					retval =
2254 					    rss_hash2bucket(inp->inp_flowid,
2255 					    inp->inp_flowtype,
2256 					    &rss_bucket);
2257 					if (retval == 0)
2258 						optval = rss_bucket;
2259 					else
2260 						error = EINVAL;
2261 					break;
2262 
2263 				case IPV6_RECVRSSBUCKETID:
2264 					optval = OPTBIT2(INP_RECVRSSBUCKETID);
2265 					break;
2266 #endif
2267 
2268 
2269 				case IPV6_VLAN_PCP:
2270 					if (OPTBIT2(INP_2PCP_SET)) {
2271 						optval = (inp->inp_flags2 &
2272 							    INP_2PCP_MASK) >>
2273 							    INP_2PCP_SHIFT;
2274 					} else {
2275 						optval = -1;
2276 					}
2277 					break;
2278 				}
2279 
2280 				if (error)
2281 					break;
2282 				error = sooptcopyout(sopt, &optval,
2283 					sizeof optval);
2284 				break;
2285 
2286 			case IPV6_PATHMTU:
2287 			{
2288 				u_long pmtu = 0;
2289 				struct ip6_mtuinfo mtuinfo;
2290 				struct in6_addr addr;
2291 
2292 				if (!(so->so_state & SS_ISCONNECTED))
2293 					return (ENOTCONN);
2294 				/*
2295 				 * XXX: we dot not consider the case of source
2296 				 * routing, or optional information to specify
2297 				 * the outgoing interface.
2298 				 * Copy faddr out of inp to avoid holding lock
2299 				 * on inp during route lookup.
2300 				 */
2301 				INP_RLOCK(inp);
2302 				bcopy(&inp->in6p_faddr, &addr, sizeof(addr));
2303 				INP_RUNLOCK(inp);
2304 				error = ip6_getpmtu_ctl(so->so_fibnum,
2305 				    &addr, &pmtu);
2306 				if (error)
2307 					break;
2308 				if (pmtu > IPV6_MAXPACKET)
2309 					pmtu = IPV6_MAXPACKET;
2310 
2311 				bzero(&mtuinfo, sizeof(mtuinfo));
2312 				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2313 				optdata = (void *)&mtuinfo;
2314 				optdatalen = sizeof(mtuinfo);
2315 				error = sooptcopyout(sopt, optdata,
2316 				    optdatalen);
2317 				break;
2318 			}
2319 
2320 			case IPV6_2292PKTINFO:
2321 			case IPV6_2292HOPLIMIT:
2322 			case IPV6_2292HOPOPTS:
2323 			case IPV6_2292RTHDR:
2324 			case IPV6_2292DSTOPTS:
2325 				switch (optname) {
2326 				case IPV6_2292PKTINFO:
2327 					optval = OPTBIT(IN6P_PKTINFO);
2328 					break;
2329 				case IPV6_2292HOPLIMIT:
2330 					optval = OPTBIT(IN6P_HOPLIMIT);
2331 					break;
2332 				case IPV6_2292HOPOPTS:
2333 					optval = OPTBIT(IN6P_HOPOPTS);
2334 					break;
2335 				case IPV6_2292RTHDR:
2336 					optval = OPTBIT(IN6P_RTHDR);
2337 					break;
2338 				case IPV6_2292DSTOPTS:
2339 					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2340 					break;
2341 				}
2342 				error = sooptcopyout(sopt, &optval,
2343 				    sizeof optval);
2344 				break;
2345 			case IPV6_PKTINFO:
2346 			case IPV6_HOPOPTS:
2347 			case IPV6_RTHDR:
2348 			case IPV6_DSTOPTS:
2349 			case IPV6_RTHDRDSTOPTS:
2350 			case IPV6_NEXTHOP:
2351 			case IPV6_TCLASS:
2352 			case IPV6_DONTFRAG:
2353 			case IPV6_USE_MIN_MTU:
2354 			case IPV6_PREFER_TEMPADDR:
2355 				error = ip6_getpcbopt(inp, optname, sopt);
2356 				break;
2357 
2358 			case IPV6_MULTICAST_IF:
2359 			case IPV6_MULTICAST_HOPS:
2360 			case IPV6_MULTICAST_LOOP:
2361 			case IPV6_MSFILTER:
2362 				error = ip6_getmoptions(inp, sopt);
2363 				break;
2364 
2365 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
2366 			case IPV6_IPSEC_POLICY:
2367 				if (IPSEC_ENABLED(ipv6)) {
2368 					error = IPSEC_PCBCTL(ipv6, inp, sopt);
2369 					break;
2370 				}
2371 				/* FALLTHROUGH */
2372 #endif /* IPSEC */
2373 			default:
2374 				error = ENOPROTOOPT;
2375 				break;
2376 			}
2377 			break;
2378 		}
2379 	}
2380 	return (error);
2381 }
2382 
2383 int
ip6_raw_ctloutput(struct socket * so,struct sockopt * sopt)2384 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2385 {
2386 	int error = 0, optval, optlen;
2387 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2388 	struct inpcb *inp = sotoinpcb(so);
2389 	int level, op, optname;
2390 
2391 	level = sopt->sopt_level;
2392 	op = sopt->sopt_dir;
2393 	optname = sopt->sopt_name;
2394 	optlen = sopt->sopt_valsize;
2395 
2396 	if (level != IPPROTO_IPV6) {
2397 		return (EINVAL);
2398 	}
2399 
2400 	switch (optname) {
2401 	case IPV6_CHECKSUM:
2402 		/*
2403 		 * For ICMPv6 sockets, no modification allowed for checksum
2404 		 * offset, permit "no change" values to help existing apps.
2405 		 *
2406 		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2407 		 * for an ICMPv6 socket will fail."
2408 		 * The current behavior does not meet RFC3542.
2409 		 */
2410 		switch (op) {
2411 		case SOPT_SET:
2412 			if (optlen != sizeof(int)) {
2413 				error = EINVAL;
2414 				break;
2415 			}
2416 			error = sooptcopyin(sopt, &optval, sizeof(optval),
2417 					    sizeof(optval));
2418 			if (error)
2419 				break;
2420 			if (optval < -1 || (optval % 2) != 0) {
2421 				/*
2422 				 * The API assumes non-negative even offset
2423 				 * values or -1 as a special value.
2424 				 */
2425 				error = EINVAL;
2426 			} else if (inp->inp_ip_p == IPPROTO_ICMPV6) {
2427 				if (optval != icmp6off)
2428 					error = EINVAL;
2429 			} else
2430 				inp->in6p_cksum = optval;
2431 			break;
2432 
2433 		case SOPT_GET:
2434 			if (inp->inp_ip_p == IPPROTO_ICMPV6)
2435 				optval = icmp6off;
2436 			else
2437 				optval = inp->in6p_cksum;
2438 
2439 			error = sooptcopyout(sopt, &optval, sizeof(optval));
2440 			break;
2441 
2442 		default:
2443 			error = EINVAL;
2444 			break;
2445 		}
2446 		break;
2447 
2448 	default:
2449 		error = ENOPROTOOPT;
2450 		break;
2451 	}
2452 
2453 	return (error);
2454 }
2455 
2456 /*
2457  * Set up IP6 options in pcb for insertion in output packets or
2458  * specifying behavior of outgoing packets.
2459  */
2460 static int
ip6_pcbopts(struct ip6_pktopts ** pktopt,struct mbuf * m,struct socket * so,struct sockopt * sopt)2461 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2462     struct socket *so, struct sockopt *sopt)
2463 {
2464 	struct ip6_pktopts *opt = *pktopt;
2465 	int error = 0;
2466 	struct thread *td = sopt->sopt_td;
2467 	struct epoch_tracker et;
2468 
2469 	/* turn off any old options. */
2470 	if (opt) {
2471 #ifdef DIAGNOSTIC
2472 		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2473 		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2474 		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2475 			printf("ip6_pcbopts: all specified options are cleared.\n");
2476 #endif
2477 		ip6_clearpktopts(opt, -1);
2478 	} else {
2479 		opt = malloc(sizeof(*opt), M_IP6OPT, M_NOWAIT);
2480 		if (opt == NULL)
2481 			return (ENOMEM);
2482 	}
2483 	*pktopt = NULL;
2484 
2485 	if (!m || m->m_len == 0) {
2486 		/*
2487 		 * Only turning off any previous options, regardless of
2488 		 * whether the opt is just created or given.
2489 		 */
2490 		free(opt, M_IP6OPT);
2491 		return (0);
2492 	}
2493 
2494 	/*  set options specified by user. */
2495 	NET_EPOCH_ENTER(et);
2496 	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2497 	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2498 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2499 		free(opt, M_IP6OPT);
2500 		NET_EPOCH_EXIT(et);
2501 		return (error);
2502 	}
2503 	NET_EPOCH_EXIT(et);
2504 	*pktopt = opt;
2505 	return (0);
2506 }
2507 
2508 /*
2509  * initialize ip6_pktopts.  beware that there are non-zero default values in
2510  * the struct.
2511  */
2512 void
ip6_initpktopts(struct ip6_pktopts * opt)2513 ip6_initpktopts(struct ip6_pktopts *opt)
2514 {
2515 
2516 	bzero(opt, sizeof(*opt));
2517 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2518 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2519 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2520 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2521 }
2522 
2523 static int
ip6_pcbopt(int optname,u_char * buf,int len,struct ip6_pktopts ** pktopt,struct ucred * cred,int uproto)2524 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2525     struct ucred *cred, int uproto)
2526 {
2527 	struct epoch_tracker et;
2528 	struct ip6_pktopts *opt;
2529 	int ret;
2530 
2531 	if (*pktopt == NULL) {
2532 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2533 		    M_NOWAIT);
2534 		if (*pktopt == NULL)
2535 			return (ENOBUFS);
2536 		ip6_initpktopts(*pktopt);
2537 	}
2538 	opt = *pktopt;
2539 
2540 	NET_EPOCH_ENTER(et);
2541 	ret = ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto);
2542 	NET_EPOCH_EXIT(et);
2543 
2544 	return (ret);
2545 }
2546 
2547 #define GET_PKTOPT_VAR(field, lenexpr) do {				\
2548 	if (pktopt && pktopt->field) {					\
2549 		INP_RUNLOCK(inp);					\
2550 		optdata = malloc(sopt->sopt_valsize, M_TEMP, M_WAITOK);	\
2551 		malloc_optdata = true;					\
2552 		INP_RLOCK(inp);						\
2553 		if (inp->inp_flags & INP_DROPPED) {			\
2554 			INP_RUNLOCK(inp);				\
2555 			free(optdata, M_TEMP);				\
2556 			return (ECONNRESET);				\
2557 		}							\
2558 		pktopt = inp->in6p_outputopts;				\
2559 		if (pktopt && pktopt->field) {				\
2560 			optdatalen = min(lenexpr, sopt->sopt_valsize);	\
2561 			bcopy(pktopt->field, optdata, optdatalen);	\
2562 		} else {						\
2563 			free(optdata, M_TEMP);				\
2564 			optdata = NULL;					\
2565 			malloc_optdata = false;				\
2566 		}							\
2567 	}								\
2568 } while(0)
2569 
2570 #define GET_PKTOPT_EXT_HDR(field) GET_PKTOPT_VAR(field,			\
2571 	(((struct ip6_ext *)pktopt->field)->ip6e_len + 1) << 3)
2572 
2573 #define GET_PKTOPT_SOCKADDR(field) GET_PKTOPT_VAR(field,		\
2574 	pktopt->field->sa_len)
2575 
2576 static int
ip6_getpcbopt(struct inpcb * inp,int optname,struct sockopt * sopt)2577 ip6_getpcbopt(struct inpcb *inp, int optname, struct sockopt *sopt)
2578 {
2579 	void *optdata = NULL;
2580 	bool malloc_optdata = false;
2581 	int optdatalen = 0;
2582 	int error = 0;
2583 	struct in6_pktinfo null_pktinfo;
2584 	int deftclass = 0, on;
2585 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2586 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2587 	struct ip6_pktopts *pktopt;
2588 
2589 	INP_RLOCK(inp);
2590 	pktopt = inp->in6p_outputopts;
2591 
2592 	switch (optname) {
2593 	case IPV6_PKTINFO:
2594 		optdata = (void *)&null_pktinfo;
2595 		if (pktopt && pktopt->ip6po_pktinfo) {
2596 			bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2597 			    sizeof(null_pktinfo));
2598 			in6_clearscope(&null_pktinfo.ipi6_addr);
2599 		} else {
2600 			/* XXX: we don't have to do this every time... */
2601 			bzero(&null_pktinfo, sizeof(null_pktinfo));
2602 		}
2603 		optdatalen = sizeof(struct in6_pktinfo);
2604 		break;
2605 	case IPV6_TCLASS:
2606 		if (pktopt && pktopt->ip6po_tclass >= 0)
2607 			deftclass = pktopt->ip6po_tclass;
2608 		optdata = (void *)&deftclass;
2609 		optdatalen = sizeof(int);
2610 		break;
2611 	case IPV6_HOPOPTS:
2612 		GET_PKTOPT_EXT_HDR(ip6po_hbh);
2613 		break;
2614 	case IPV6_RTHDR:
2615 		GET_PKTOPT_EXT_HDR(ip6po_rthdr);
2616 		break;
2617 	case IPV6_RTHDRDSTOPTS:
2618 		GET_PKTOPT_EXT_HDR(ip6po_dest1);
2619 		break;
2620 	case IPV6_DSTOPTS:
2621 		GET_PKTOPT_EXT_HDR(ip6po_dest2);
2622 		break;
2623 	case IPV6_NEXTHOP:
2624 		GET_PKTOPT_SOCKADDR(ip6po_nexthop);
2625 		break;
2626 	case IPV6_USE_MIN_MTU:
2627 		if (pktopt)
2628 			defminmtu = pktopt->ip6po_minmtu;
2629 		optdata = (void *)&defminmtu;
2630 		optdatalen = sizeof(int);
2631 		break;
2632 	case IPV6_DONTFRAG:
2633 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2634 			on = 1;
2635 		else
2636 			on = 0;
2637 		optdata = (void *)&on;
2638 		optdatalen = sizeof(on);
2639 		break;
2640 	case IPV6_PREFER_TEMPADDR:
2641 		if (pktopt)
2642 			defpreftemp = pktopt->ip6po_prefer_tempaddr;
2643 		optdata = (void *)&defpreftemp;
2644 		optdatalen = sizeof(int);
2645 		break;
2646 	default:		/* should not happen */
2647 #ifdef DIAGNOSTIC
2648 		panic("ip6_getpcbopt: unexpected option\n");
2649 #endif
2650 		INP_RUNLOCK(inp);
2651 		return (ENOPROTOOPT);
2652 	}
2653 	INP_RUNLOCK(inp);
2654 
2655 	error = sooptcopyout(sopt, optdata, optdatalen);
2656 	if (malloc_optdata)
2657 		free(optdata, M_TEMP);
2658 
2659 	return (error);
2660 }
2661 
2662 void
ip6_clearpktopts(struct ip6_pktopts * pktopt,int optname)2663 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2664 {
2665 	if (pktopt == NULL)
2666 		return;
2667 
2668 	if (optname == -1 || optname == IPV6_PKTINFO) {
2669 		if (pktopt->ip6po_pktinfo)
2670 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
2671 		pktopt->ip6po_pktinfo = NULL;
2672 	}
2673 	if (optname == -1 || optname == IPV6_HOPLIMIT) {
2674 		pktopt->ip6po_hlim = -1;
2675 		pktopt->ip6po_valid &= ~IP6PO_VALID_HLIM;
2676 	}
2677 	if (optname == -1 || optname == IPV6_TCLASS) {
2678 		pktopt->ip6po_tclass = -1;
2679 		pktopt->ip6po_valid &= ~IP6PO_VALID_TC;
2680 	}
2681 	if (optname == -1 || optname == IPV6_NEXTHOP) {
2682 		if (pktopt->ip6po_nextroute.ro_nh) {
2683 			NH_FREE(pktopt->ip6po_nextroute.ro_nh);
2684 			pktopt->ip6po_nextroute.ro_nh = NULL;
2685 		}
2686 		if (pktopt->ip6po_nexthop)
2687 			free(pktopt->ip6po_nexthop, M_IP6OPT);
2688 		pktopt->ip6po_nexthop = NULL;
2689 		pktopt->ip6po_valid &= ~IP6PO_VALID_NHINFO;
2690 	}
2691 	if (optname == -1 || optname == IPV6_HOPOPTS) {
2692 		if (pktopt->ip6po_hbh)
2693 			free(pktopt->ip6po_hbh, M_IP6OPT);
2694 		pktopt->ip6po_hbh = NULL;
2695 		pktopt->ip6po_valid &= ~IP6PO_VALID_HBH;
2696 	}
2697 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2698 		if (pktopt->ip6po_dest1)
2699 			free(pktopt->ip6po_dest1, M_IP6OPT);
2700 		pktopt->ip6po_dest1 = NULL;
2701 		pktopt->ip6po_valid &= ~IP6PO_VALID_DEST1;
2702 	}
2703 	if (optname == -1 || optname == IPV6_RTHDR) {
2704 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2705 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2706 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2707 		if (pktopt->ip6po_route.ro_nh) {
2708 			NH_FREE(pktopt->ip6po_route.ro_nh);
2709 			pktopt->ip6po_route.ro_nh = NULL;
2710 		}
2711 		pktopt->ip6po_valid &= ~IP6PO_VALID_RHINFO;
2712 	}
2713 	if (optname == -1 || optname == IPV6_DSTOPTS) {
2714 		if (pktopt->ip6po_dest2)
2715 			free(pktopt->ip6po_dest2, M_IP6OPT);
2716 		pktopt->ip6po_dest2 = NULL;
2717 		pktopt->ip6po_valid &= ~IP6PO_VALID_DEST2;
2718 	}
2719 }
2720 
2721 #define PKTOPT_EXTHDRCPY(type) \
2722 do {\
2723 	if (src->type) {\
2724 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2725 		dst->type = malloc(hlen, M_IP6OPT, canwait);\
2726 		if (dst->type == NULL)\
2727 			goto bad;\
2728 		bcopy(src->type, dst->type, hlen);\
2729 	}\
2730 } while (/*CONSTCOND*/ 0)
2731 
2732 static int
copypktopts(struct ip6_pktopts * dst,struct ip6_pktopts * src,int canwait)2733 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2734 {
2735 	if (dst == NULL || src == NULL)  {
2736 		printf("ip6_clearpktopts: invalid argument\n");
2737 		return (EINVAL);
2738 	}
2739 
2740 	dst->ip6po_hlim = src->ip6po_hlim;
2741 	dst->ip6po_tclass = src->ip6po_tclass;
2742 	dst->ip6po_flags = src->ip6po_flags;
2743 	dst->ip6po_minmtu = src->ip6po_minmtu;
2744 	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2745 	if (src->ip6po_pktinfo) {
2746 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2747 		    M_IP6OPT, canwait);
2748 		if (dst->ip6po_pktinfo == NULL)
2749 			goto bad;
2750 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2751 	}
2752 	if (src->ip6po_nexthop) {
2753 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2754 		    M_IP6OPT, canwait);
2755 		if (dst->ip6po_nexthop == NULL)
2756 			goto bad;
2757 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2758 		    src->ip6po_nexthop->sa_len);
2759 	}
2760 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2761 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2762 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2763 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2764 	dst->ip6po_valid = src->ip6po_valid;
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 		opt->ip6po_valid |= IP6PO_VALID_PKTINFO;
2995 		break;
2996 	}
2997 
2998 	case IPV6_2292HOPLIMIT:
2999 	case IPV6_HOPLIMIT:
3000 	{
3001 		int *hlimp;
3002 
3003 		/*
3004 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
3005 		 * to simplify the ordering among hoplimit options.
3006 		 */
3007 		if (optname == IPV6_HOPLIMIT && sticky)
3008 			return (ENOPROTOOPT);
3009 
3010 		if (len != sizeof(int))
3011 			return (EINVAL);
3012 		hlimp = (int *)buf;
3013 		if (*hlimp < -1 || *hlimp > 255)
3014 			return (EINVAL);
3015 
3016 		opt->ip6po_hlim = *hlimp;
3017 		opt->ip6po_valid |= IP6PO_VALID_HLIM;
3018 		break;
3019 	}
3020 
3021 	case IPV6_TCLASS:
3022 	{
3023 		int tclass;
3024 
3025 		if (len != sizeof(int))
3026 			return (EINVAL);
3027 		tclass = *(int *)buf;
3028 		if (tclass < -1 || tclass > 255)
3029 			return (EINVAL);
3030 
3031 		opt->ip6po_tclass = tclass;
3032 		opt->ip6po_valid |= IP6PO_VALID_TC;
3033 		break;
3034 	}
3035 
3036 	case IPV6_2292NEXTHOP:
3037 	case IPV6_NEXTHOP:
3038 		if (cred != NULL) {
3039 			error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
3040 			if (error)
3041 				return (error);
3042 		}
3043 
3044 		if (len == 0) {	/* just remove the option */
3045 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
3046 			break;
3047 		}
3048 
3049 		/* check if cmsg_len is large enough for sa_len */
3050 		if (len < sizeof(struct sockaddr) || len < *buf)
3051 			return (EINVAL);
3052 
3053 		switch (((struct sockaddr *)buf)->sa_family) {
3054 		case AF_INET6:
3055 		{
3056 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
3057 			int error;
3058 
3059 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
3060 				return (EINVAL);
3061 
3062 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
3063 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
3064 				return (EINVAL);
3065 			}
3066 			if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
3067 			    != 0) {
3068 				return (error);
3069 			}
3070 			break;
3071 		}
3072 		case AF_LINK:	/* should eventually be supported */
3073 		default:
3074 			return (EAFNOSUPPORT);
3075 		}
3076 
3077 		/* turn off the previous option, then set the new option. */
3078 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
3079 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
3080 		if (opt->ip6po_nexthop == NULL)
3081 			return (ENOBUFS);
3082 		bcopy(buf, opt->ip6po_nexthop, *buf);
3083 		opt->ip6po_valid |= IP6PO_VALID_NHINFO;
3084 		break;
3085 
3086 	case IPV6_2292HOPOPTS:
3087 	case IPV6_HOPOPTS:
3088 	{
3089 		struct ip6_hbh *hbh;
3090 		int hbhlen;
3091 
3092 		/*
3093 		 * XXX: We don't allow a non-privileged user to set ANY HbH
3094 		 * options, since per-option restriction has too much
3095 		 * overhead.
3096 		 */
3097 		if (cred != NULL) {
3098 			error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
3099 			if (error)
3100 				return (error);
3101 		}
3102 
3103 		if (len == 0) {
3104 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
3105 			break;	/* just remove the option */
3106 		}
3107 
3108 		/* message length validation */
3109 		if (len < sizeof(struct ip6_hbh))
3110 			return (EINVAL);
3111 		hbh = (struct ip6_hbh *)buf;
3112 		hbhlen = (hbh->ip6h_len + 1) << 3;
3113 		if (len != hbhlen)
3114 			return (EINVAL);
3115 
3116 		/* turn off the previous option, then set the new option. */
3117 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
3118 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
3119 		if (opt->ip6po_hbh == NULL)
3120 			return (ENOBUFS);
3121 		bcopy(hbh, opt->ip6po_hbh, hbhlen);
3122 		opt->ip6po_valid |= IP6PO_VALID_HBH;
3123 
3124 		break;
3125 	}
3126 
3127 	case IPV6_2292DSTOPTS:
3128 	case IPV6_DSTOPTS:
3129 	case IPV6_RTHDRDSTOPTS:
3130 	{
3131 		struct ip6_dest *dest, **newdest = NULL;
3132 		int destlen;
3133 
3134 		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
3135 			error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
3136 			if (error)
3137 				return (error);
3138 		}
3139 
3140 		if (len == 0) {
3141 			ip6_clearpktopts(opt, optname);
3142 			break;	/* just remove the option */
3143 		}
3144 
3145 		/* message length validation */
3146 		if (len < sizeof(struct ip6_dest))
3147 			return (EINVAL);
3148 		dest = (struct ip6_dest *)buf;
3149 		destlen = (dest->ip6d_len + 1) << 3;
3150 		if (len != destlen)
3151 			return (EINVAL);
3152 
3153 		/*
3154 		 * Determine the position that the destination options header
3155 		 * should be inserted; before or after the routing header.
3156 		 */
3157 		switch (optname) {
3158 		case IPV6_2292DSTOPTS:
3159 			/*
3160 			 * The old advacned API is ambiguous on this point.
3161 			 * Our approach is to determine the position based
3162 			 * according to the existence of a routing header.
3163 			 * Note, however, that this depends on the order of the
3164 			 * extension headers in the ancillary data; the 1st
3165 			 * part of the destination options header must appear
3166 			 * before the routing header in the ancillary data,
3167 			 * too.
3168 			 * RFC3542 solved the ambiguity by introducing
3169 			 * separate ancillary data or option types.
3170 			 */
3171 			if (opt->ip6po_rthdr == NULL)
3172 				newdest = &opt->ip6po_dest1;
3173 			else
3174 				newdest = &opt->ip6po_dest2;
3175 			break;
3176 		case IPV6_RTHDRDSTOPTS:
3177 			newdest = &opt->ip6po_dest1;
3178 			break;
3179 		case IPV6_DSTOPTS:
3180 			newdest = &opt->ip6po_dest2;
3181 			break;
3182 		}
3183 
3184 		/* turn off the previous option, then set the new option. */
3185 		ip6_clearpktopts(opt, optname);
3186 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
3187 		if (*newdest == NULL)
3188 			return (ENOBUFS);
3189 		bcopy(dest, *newdest, destlen);
3190 		if (newdest == &opt->ip6po_dest1)
3191 			opt->ip6po_valid |= IP6PO_VALID_DEST1;
3192 		else
3193 			opt->ip6po_valid |= IP6PO_VALID_DEST2;
3194 
3195 		break;
3196 	}
3197 
3198 	case IPV6_2292RTHDR:
3199 	case IPV6_RTHDR:
3200 	{
3201 		struct ip6_rthdr *rth;
3202 		int rthlen;
3203 
3204 		if (len == 0) {
3205 			ip6_clearpktopts(opt, IPV6_RTHDR);
3206 			break;	/* just remove the option */
3207 		}
3208 
3209 		/* message length validation */
3210 		if (len < sizeof(struct ip6_rthdr))
3211 			return (EINVAL);
3212 		rth = (struct ip6_rthdr *)buf;
3213 		rthlen = (rth->ip6r_len + 1) << 3;
3214 		if (len != rthlen)
3215 			return (EINVAL);
3216 
3217 		switch (rth->ip6r_type) {
3218 		case IPV6_RTHDR_TYPE_0:
3219 			if (rth->ip6r_len == 0)	/* must contain one addr */
3220 				return (EINVAL);
3221 			if (rth->ip6r_len % 2) /* length must be even */
3222 				return (EINVAL);
3223 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
3224 				return (EINVAL);
3225 			break;
3226 		default:
3227 			return (EINVAL);	/* not supported */
3228 		}
3229 
3230 		/* turn off the previous option */
3231 		ip6_clearpktopts(opt, IPV6_RTHDR);
3232 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
3233 		if (opt->ip6po_rthdr == NULL)
3234 			return (ENOBUFS);
3235 		bcopy(rth, opt->ip6po_rthdr, rthlen);
3236 		opt->ip6po_valid |= IP6PO_VALID_RHINFO;
3237 
3238 		break;
3239 	}
3240 
3241 	case IPV6_USE_MIN_MTU:
3242 		if (len != sizeof(int))
3243 			return (EINVAL);
3244 		minmtupolicy = *(int *)buf;
3245 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
3246 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
3247 		    minmtupolicy != IP6PO_MINMTU_ALL) {
3248 			return (EINVAL);
3249 		}
3250 		opt->ip6po_minmtu = minmtupolicy;
3251 		break;
3252 
3253 	case IPV6_DONTFRAG:
3254 		if (len != sizeof(int))
3255 			return (EINVAL);
3256 
3257 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
3258 			/*
3259 			 * we ignore this option for TCP sockets.
3260 			 * (RFC3542 leaves this case unspecified.)
3261 			 */
3262 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
3263 		} else
3264 			opt->ip6po_flags |= IP6PO_DONTFRAG;
3265 		break;
3266 
3267 	case IPV6_PREFER_TEMPADDR:
3268 		if (len != sizeof(int))
3269 			return (EINVAL);
3270 		preftemp = *(int *)buf;
3271 		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3272 		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3273 		    preftemp != IP6PO_TEMPADDR_PREFER) {
3274 			return (EINVAL);
3275 		}
3276 		opt->ip6po_prefer_tempaddr = preftemp;
3277 		break;
3278 
3279 	default:
3280 		return (ENOPROTOOPT);
3281 	} /* end of switch */
3282 
3283 	return (0);
3284 }
3285 
3286 /*
3287  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3288  * packet to the input queue of a specified interface.  Note that this
3289  * calls the output routine of the loopback "driver", but with an interface
3290  * pointer that might NOT be &loif -- easier than replicating that code here.
3291  */
3292 void
ip6_mloopback(struct ifnet * ifp,struct mbuf * m)3293 ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
3294 {
3295 	struct mbuf *copym;
3296 	struct ip6_hdr *ip6;
3297 
3298 	copym = m_copym(m, 0, M_COPYALL, M_NOWAIT);
3299 	if (copym == NULL)
3300 		return;
3301 
3302 	/*
3303 	 * Make sure to deep-copy IPv6 header portion in case the data
3304 	 * is in an mbuf cluster, so that we can safely override the IPv6
3305 	 * header portion later.
3306 	 */
3307 	if (!M_WRITABLE(copym) ||
3308 	    copym->m_len < sizeof(struct ip6_hdr)) {
3309 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
3310 		if (copym == NULL)
3311 			return;
3312 	}
3313 	ip6 = mtod(copym, struct ip6_hdr *);
3314 	/*
3315 	 * clear embedded scope identifiers if necessary.
3316 	 * in6_clearscope will touch the addresses only when necessary.
3317 	 */
3318 	in6_clearscope(&ip6->ip6_src);
3319 	in6_clearscope(&ip6->ip6_dst);
3320 	if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3321 		copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3322 		    CSUM_PSEUDO_HDR;
3323 		copym->m_pkthdr.csum_data = 0xffff;
3324 	}
3325 	if_simloop(ifp, copym, AF_INET6, 0);
3326 }
3327 
3328 /*
3329  * Chop IPv6 header off from the payload.
3330  */
3331 static int
ip6_splithdr(struct mbuf * m,struct ip6_exthdrs * exthdrs)3332 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3333 {
3334 	struct mbuf *mh;
3335 	struct ip6_hdr *ip6;
3336 
3337 	ip6 = mtod(m, struct ip6_hdr *);
3338 	if (m->m_len > sizeof(*ip6)) {
3339 		mh = m_gethdr(M_NOWAIT, MT_DATA);
3340 		if (mh == NULL) {
3341 			m_freem(m);
3342 			return ENOBUFS;
3343 		}
3344 		m_move_pkthdr(mh, m);
3345 		M_ALIGN(mh, sizeof(*ip6));
3346 		m->m_len -= sizeof(*ip6);
3347 		m->m_data += sizeof(*ip6);
3348 		mh->m_next = m;
3349 		m = mh;
3350 		m->m_len = sizeof(*ip6);
3351 		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3352 	}
3353 	exthdrs->ip6e_ip6 = m;
3354 	return 0;
3355 }
3356 
3357 /*
3358  * Compute IPv6 extension header length.
3359  */
3360 int
ip6_optlen(struct inpcb * inp)3361 ip6_optlen(struct inpcb *inp)
3362 {
3363 	int len;
3364 
3365 	if (!inp->in6p_outputopts)
3366 		return 0;
3367 
3368 	len = 0;
3369 #define elen(x) \
3370     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3371 
3372 	len += elen(inp->in6p_outputopts->ip6po_hbh);
3373 	if (inp->in6p_outputopts->ip6po_rthdr)
3374 		/* dest1 is valid with rthdr only */
3375 		len += elen(inp->in6p_outputopts->ip6po_dest1);
3376 	len += elen(inp->in6p_outputopts->ip6po_rthdr);
3377 	len += elen(inp->in6p_outputopts->ip6po_dest2);
3378 	return len;
3379 #undef elen
3380 }
3381