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udp6_usrreq.c revision 1.13
      1 /*	$NetBSD: udp6_usrreq.c,v 1.13 1999/09/13 12:15:56 itojun Exp $	*/
      2 
      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 
     32 /*
     33  * Copyright (c) 1982, 1986, 1989, 1993
     34  *	The Regents of the University of California.  All rights reserved.
     35  *
     36  * Redistribution and use in source and binary forms, with or without
     37  * modification, are permitted provided that the following conditions
     38  * are met:
     39  * 1. Redistributions of source code must retain the above copyright
     40  *    notice, this list of conditions and the following disclaimer.
     41  * 2. Redistributions in binary form must reproduce the above copyright
     42  *    notice, this list of conditions and the following disclaimer in the
     43  *    documentation and/or other materials provided with the distribution.
     44  * 3. All advertising materials mentioning features or use of this software
     45  *    must display the following acknowledgement:
     46  *	This product includes software developed by the University of
     47  *	California, Berkeley and its contributors.
     48  * 4. Neither the name of the University nor the names of its contributors
     49  *    may be used to endorse or promote products derived from this software
     50  *    without specific prior written permission.
     51  *
     52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     62  * SUCH DAMAGE.
     63  *
     64  *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
     65  */
     66 
     67 #ifdef __NetBSD__	/*XXX*/
     68 #include "opt_ipsec.h"
     69 #endif
     70 
     71 #include <sys/param.h>
     72 #include <sys/malloc.h>
     73 #include <sys/mbuf.h>
     74 #include <sys/protosw.h>
     75 #include <sys/socket.h>
     76 #include <sys/socketvar.h>
     77 #include <sys/errno.h>
     78 #include <sys/stat.h>
     79 #include <sys/systm.h>
     80 #ifdef __NetBSD__
     81 #include <sys/proc.h>
     82 #endif
     83 #include <sys/syslog.h>
     84 
     85 #include <net/if.h>
     86 #include <net/route.h>
     87 #include <net/if_types.h>
     88 
     89 #include <netinet/in.h>
     90 #include <netinet/in_var.h>
     91 #include <netinet6/ip6.h>
     92 #include <netinet6/in6_pcb.h>
     93 #include <netinet6/ip6_var.h>
     94 #include <netinet6/icmp6.h>
     95 #include <netinet6/udp6.h>
     96 #include <netinet6/udp6_var.h>
     97 
     98 #ifdef IPSEC
     99 #include <netinet6/ipsec.h>
    100 #endif /*IPSEC*/
    101 
    102 #include "faith.h"
    103 
    104 /*
    105  * UDP protocol inplementation.
    106  * Per RFC 768, August, 1980.
    107  */
    108 
    109 struct	in6pcb *udp6_last_in6pcb = &udb6;
    110 
    111 static	int in6_mcmatch __P((struct in6pcb *, struct in6_addr *, struct ifnet *));
    112 static	void udp6_detach __P((struct in6pcb *));
    113 static	void udp6_notify __P((struct in6pcb *, int));
    114 
    115 void
    116 udp6_init()
    117 {
    118 	udb6.in6p_next = udb6.in6p_prev = &udb6;
    119 }
    120 
    121 static int
    122 in6_mcmatch(in6p, ia6, ifp)
    123 	struct in6pcb *in6p;
    124 	register struct in6_addr *ia6;
    125 	struct ifnet *ifp;
    126 {
    127 	struct ip6_moptions *im6o = in6p->in6p_moptions;
    128 	struct in6_multi_mship *imm;
    129 
    130 	if (im6o == NULL)
    131 		return 0;
    132 
    133 	for (imm = im6o->im6o_memberships.lh_first; imm != NULL;
    134 	     imm = imm->i6mm_chain.le_next) {
    135 		if ((ifp == NULL ||
    136 		     imm->i6mm_maddr->in6m_ifp == ifp) &&
    137 		    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
    138 				       ia6))
    139 			return 1;
    140 	}
    141 	return 0;
    142 }
    143 
    144 int
    145 udp6_input(mp, offp, proto)
    146 	struct mbuf **mp;
    147 	int *offp, proto;
    148 {
    149 	struct mbuf *m = *mp;
    150 	register struct ip6_hdr *ip6;
    151 	register struct udphdr *uh;
    152 	register struct in6pcb *in6p;
    153 	struct	mbuf *opts = 0;
    154 	int off = *offp;
    155 	int plen, ulen;
    156 	struct sockaddr_in6 udp_in6;
    157 
    158 #if defined(NFAITH) && 0 < NFAITH
    159 	if (m->m_pkthdr.rcvif) {
    160 		if (m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
    161 			/* send icmp6 host unreach? */
    162 			m_freem(m);
    163 			return IPPROTO_DONE;
    164 		}
    165 	}
    166 #endif
    167 	udp6stat.udp6s_ipackets++;
    168 
    169 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
    170 
    171 	ip6 = mtod(m, struct ip6_hdr *);
    172 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
    173 	uh = (struct udphdr *)((caddr_t)ip6 + off);
    174 	ulen = ntohs((u_short)uh->uh_ulen);
    175 
    176 	if (plen != ulen) {
    177 		udp6stat.udp6s_badlen++;
    178 		goto bad;
    179 	}
    180 
    181 	/*
    182 	 * Checksum extended UDP header and data.
    183 	 */
    184 	if (uh->uh_sum == 0)
    185 		udp6stat.udp6s_nosum++;
    186 	else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
    187 		udp6stat.udp6s_badsum++;
    188 		goto bad;
    189 	}
    190 
    191 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    192 		struct	in6pcb *last;
    193 
    194 		/*
    195 		 * Deliver a multicast datagram to all sockets
    196 		 * for which the local and remote addresses and ports match
    197 		 * those of the incoming datagram.  This allows more than
    198 		 * one process to receive multicasts on the same port.
    199 		 * (This really ought to be done for unicast datagrams as
    200 		 * well, but that would cause problems with existing
    201 		 * applications that open both address-specific sockets and
    202 		 * a wildcard socket listening to the same port -- they would
    203 		 * end up receiving duplicates of every unicast datagram.
    204 		 * Those applications open the multiple sockets to overcome an
    205 		 * inadequacy of the UDP socket interface, but for backwards
    206 		 * compatibility we avoid the problem here rather than
    207 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
    208 		 */
    209 
    210 		/*
    211 		 * In a case that laddr should be set to the link-local
    212 		 * address (this happens in RIPng), the multicast address
    213 		 * specified in the received packet does not match with
    214 		 * laddr. To cure this situation, the matching is relaxed
    215 		 * if the receiving interface is the same as one specified
    216 		 * in the socket and if the destination multicast address
    217 		 * matches one of the multicast groups specified in the socket.
    218 		 */
    219 
    220 		/*
    221 		 * Construct sockaddr format source address.
    222 		 */
    223 		bzero(&udp_in6, sizeof(udp_in6));
    224 		udp_in6.sin6_len = sizeof(struct sockaddr_in6);
    225 		udp_in6.sin6_family = AF_INET6;
    226 		udp_in6.sin6_port = uh->uh_sport;
    227 		udp_in6.sin6_addr = ip6->ip6_src;
    228 		if (IN6_IS_SCOPE_LINKLOCAL(&udp_in6.sin6_addr))
    229 			udp_in6.sin6_addr.s6_addr16[1] = 0;
    230 		if (m->m_pkthdr.rcvif) {
    231 			if (IN6_IS_SCOPE_LINKLOCAL(&udp_in6.sin6_addr)) {
    232 				udp_in6.sin6_scope_id =
    233 					m->m_pkthdr.rcvif->if_index;
    234 			} else
    235 				udp_in6.sin6_scope_id = 0;
    236 		} else
    237 			udp_in6.sin6_scope_id = 0;
    238 		/*
    239 		 * KAME note: usually we drop udphdr from mbuf here.
    240 		 * We need udphdr for IPsec processing so we do that later.
    241 		 */
    242 
    243 		/*
    244 		 * Locate pcb(s) for datagram.
    245 		 * (Algorithm copied from raw_intr().)
    246 		 */
    247 		last = NULL;
    248 		for (in6p = udb6.in6p_next;
    249 		     in6p != &udb6;
    250 		     in6p = in6p->in6p_next) {
    251 			if (in6p->in6p_lport != uh->uh_dport)
    252 				continue;
    253 			if (!IN6_IS_ADDR_ANY(&in6p->in6p_laddr)) {
    254 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
    255 							&ip6->ip6_dst) &&
    256 				    !in6_mcmatch(in6p, &ip6->ip6_dst,
    257 						 m->m_pkthdr.rcvif))
    258 					continue;
    259 			}
    260 			if (!IN6_IS_ADDR_ANY(&in6p->in6p_faddr)) {
    261 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
    262 							&ip6->ip6_src) ||
    263 				   in6p->in6p_fport != uh->uh_sport)
    264 					continue;
    265 			}
    266 
    267 			if (last != NULL) {
    268 				struct	mbuf *n;
    269 
    270 #ifdef IPSEC
    271 				/*
    272 				 * Check AH/ESP integrity.
    273 				 */
    274 				if (last != NULL && ipsec6_in_reject(m, last)) {
    275 					ipsec6stat.in_polvio++;
    276 					/* do not inject data into pcb */
    277 				} else
    278 #endif /*IPSEC*/
    279 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
    280 					/*
    281 					 * KAME NOTE: do not
    282 					 * m_copy(m, offset, ...) above.
    283 					 * sbappendaddr() expects M_PKTHDR,
    284 					 * and m_copy() will copy M_PKTHDR
    285 					 * only if offset is 0.
    286 					 */
    287 					if (last->in6p_flags & IN6P_CONTROLOPTS
    288 					 || last->in6p_socket->so_options & SO_TIMESTAMP) {
    289 						ip6_savecontrol(last, &opts,
    290 								ip6, n);
    291 					}
    292 
    293 					m_adj(n, off + sizeof(struct udphdr));
    294 					if (sbappendaddr(&last->in6p_socket->so_rcv,
    295 							(struct sockaddr *)&udp_in6,
    296 							n, opts) == 0) {
    297 						m_freem(n);
    298 						if (opts)
    299 							m_freem(opts);
    300 						udp6stat.udp6s_fullsock++;
    301 					} else
    302 						sorwakeup(last->in6p_socket);
    303 					opts = 0;
    304 				}
    305 			}
    306 			last = in6p;
    307 			/*
    308 			 * Don't look for additional matches if this one does
    309 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
    310 			 * socket options set.  This heuristic avoids searching
    311 			 * through all pcbs in the common case of a non-shared
    312 			 * port.  It assumes that an application will never
    313 			 * clear these options after setting them.
    314 			 */
    315 			if ((last->in6p_socket->so_options &
    316 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
    317 				break;
    318 		}
    319 
    320 		if (last == NULL) {
    321 			/*
    322 			 * No matching pcb found; discard datagram.
    323 			 * (No need to send an ICMP Port Unreachable
    324 			 * for a broadcast or multicast datgram.)
    325 			 */
    326 			udp6stat.udp6s_noport++;
    327 			udp6stat.udp6s_noportmcast++;
    328 			goto bad;
    329 		}
    330 #ifdef IPSEC
    331 		/*
    332 		 * Check AH/ESP integrity.
    333 		 */
    334 		if (last != NULL && ipsec6_in_reject(m, last)) {
    335 			ipsec6stat.in_polvio++;
    336 			goto bad;
    337 		}
    338 #endif /*IPSEC*/
    339 		if (last->in6p_flags & IN6P_CONTROLOPTS
    340 		 || last->in6p_socket->so_options & SO_TIMESTAMP) {
    341 			ip6_savecontrol(last, &opts, ip6, m);
    342 		}
    343 
    344 		m_adj(m, off + sizeof(struct udphdr));
    345 		if (sbappendaddr(&last->in6p_socket->so_rcv,
    346 				(struct sockaddr *)&udp_in6,
    347 				m, opts) == 0) {
    348 			udp6stat.udp6s_fullsock++;
    349 			goto bad;
    350 		}
    351 		sorwakeup(last->in6p_socket);
    352 		return IPPROTO_DONE;
    353 	}
    354 	/*
    355 	 * Locate pcb for datagram.
    356 	 */
    357 	in6p = udp6_last_in6pcb;
    358 	if (in6p->in6p_lport != uh->uh_dport ||
    359 	   in6p->in6p_fport != uh->uh_sport ||
    360 	   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src) ||
    361 	   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) {
    362 		in6p = in6_pcblookup(&udb6,
    363 				     &ip6->ip6_src, uh->uh_sport,
    364 				     &ip6->ip6_dst, uh->uh_dport,
    365 				     IN6PLOOKUP_WILDCARD);
    366 		if (in6p)
    367 			udp6_last_in6pcb = in6p;
    368 		udp6stat.udp6ps_pcbcachemiss++;
    369 	}
    370 	if (in6p == 0) {
    371 		udp6stat.udp6s_noport++;
    372 		if (m->m_flags & M_MCAST) {
    373 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
    374 			udp6stat.udp6s_noportmcast++;
    375 			goto bad;
    376 		}
    377 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
    378 		return IPPROTO_DONE;
    379 	}
    380 #ifdef IPSEC
    381 	/*
    382 	 * Check AH/ESP integrity.
    383 	 */
    384 	if (in6p != NULL && ipsec6_in_reject(m, in6p)) {
    385 		ipsec6stat.in_polvio++;
    386 		goto bad;
    387 	}
    388 #endif /*IPSEC*/
    389 
    390 	/*
    391 	 * Construct sockaddr format source address.
    392 	 * Stuff source address and datagram in user buffer.
    393 	 */
    394 	bzero(&udp_in6, sizeof(udp_in6));
    395 	udp_in6.sin6_len = sizeof(struct sockaddr_in6);
    396 	udp_in6.sin6_family = AF_INET6;
    397 	udp_in6.sin6_port = uh->uh_sport;
    398 	udp_in6.sin6_addr = ip6->ip6_src;
    399 	if (IN6_IS_SCOPE_LINKLOCAL(&udp_in6.sin6_addr))
    400 		udp_in6.sin6_addr.s6_addr16[1] = 0;
    401 	if (m->m_pkthdr.rcvif) {
    402 		if (IN6_IS_SCOPE_LINKLOCAL(&udp_in6.sin6_addr))
    403 			udp_in6.sin6_scope_id = m->m_pkthdr.rcvif->if_index;
    404 		else
    405 			udp_in6.sin6_scope_id = 0;
    406 	} else
    407 		udp_in6.sin6_scope_id = 0;
    408 	if (in6p->in6p_flags & IN6P_CONTROLOPTS
    409 	 || in6p->in6p_socket->so_options & SO_TIMESTAMP) {
    410 		ip6_savecontrol(in6p, &opts, ip6, m);
    411 	}
    412 
    413 	m_adj(m, off + sizeof(struct udphdr));
    414 	if (sbappendaddr(&in6p->in6p_socket->so_rcv,
    415 			(struct sockaddr *)&udp_in6,
    416 			m, opts) == 0) {
    417 		udp6stat.udp6s_fullsock++;
    418 		goto bad;
    419 	}
    420 	sorwakeup(in6p->in6p_socket);
    421 	return IPPROTO_DONE;
    422 bad:
    423 	if (m)
    424 		m_freem(m);
    425 	if (opts)
    426 		m_freem(opts);
    427 	return IPPROTO_DONE;
    428 }
    429 
    430 /*
    431  * Notify a udp user of an asynchronous error;
    432  * just wake up so tat he can collect error status.
    433  */
    434 static	void
    435 udp6_notify(in6p, errno)
    436 	register struct in6pcb *in6p;
    437 	int errno;
    438 {
    439 	in6p->in6p_socket->so_error = errno;
    440 	sorwakeup(in6p->in6p_socket);
    441 	sowwakeup(in6p->in6p_socket);
    442 }
    443 
    444 void
    445 udp6_ctlinput(cmd, sa, ip6, m, off)
    446 	int cmd;
    447 	struct sockaddr *sa;
    448 	register struct ip6_hdr *ip6;
    449 	struct mbuf *m;
    450 	int off;
    451 {
    452 	register struct udphdr *uhp;
    453 	struct udphdr uh;
    454 	struct sockaddr_in6 sa6;
    455 
    456 	if (sa->sa_family != AF_INET6 ||
    457 	    sa->sa_len != sizeof(struct sockaddr_in6))
    458 		return;
    459 #if 0
    460 	if (cmd == PRC_IFNEWADDR)
    461 		in6_mrejoin(&udb6);
    462 	else
    463 #endif
    464 	if (!PRC_IS_REDIRECT(cmd) &&
    465 	    ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
    466 		return;
    467 
    468 	/* translate addresses into internal form */
    469 	sa6 = *(struct sockaddr_in6 *)sa;
    470 	if (IN6_IS_ADDR_LINKLOCAL(&sa6.sin6_addr))
    471 		sa6.sin6_addr.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
    472 
    473 	if (ip6) {
    474 		/*
    475 		 * XXX: We assume that when IPV6 is non NULL,
    476 		 * M and OFF are valid.
    477 		 */
    478 		struct in6_addr s;
    479 
    480 		/* translate addresses into internal form */
    481 		memcpy(&s, &ip6->ip6_src, sizeof(s));
    482 		if (IN6_IS_ADDR_LINKLOCAL(&s))
    483 			s.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
    484 
    485 		if (m->m_len < off + sizeof(uh)) {
    486 			/*
    487 			 * this should be rare case,
    488 			 * so we compromise on this copy...
    489 			 */
    490 			m_copydata(m, off, sizeof(uh), (caddr_t)&uh);
    491 			uhp = &uh;
    492 		} else
    493 			uhp = (struct udphdr *)(mtod(m, caddr_t) + off);
    494 		(void) in6_pcbnotify(&udb6, (struct sockaddr *)&sa6,
    495 					uhp->uh_dport, &s,
    496 					uhp->uh_sport, cmd, udp6_notify);
    497 	} else {
    498 		(void) in6_pcbnotify(&udb6, (struct sockaddr *)&sa6, 0,
    499 					&zeroin6_addr, 0, cmd, udp6_notify);
    500 	}
    501 }
    502 
    503 int
    504 udp6_output(in6p, m, addr6, control)
    505 	register struct in6pcb *in6p;
    506 	register struct mbuf *m;
    507 	struct mbuf *addr6, *control;
    508 {
    509 	register int ulen = m->m_pkthdr.len;
    510 	int plen = sizeof(struct udphdr) + ulen;
    511 	struct ip6_hdr *ip6;
    512 	struct udphdr *udp6;
    513 	struct	in6_addr laddr6;
    514 	int s = 0, error = 0;
    515 	struct ip6_pktopts opt, *stickyopt = in6p->in6p_outputopts;
    516 	int priv = 0;
    517 	struct proc *p = curproc;	/* XXX */
    518 
    519 	if (p && !suser(p->p_ucred, &p->p_acflag))
    520 		priv = 1;
    521 	if (control) {
    522 		if ((error = ip6_setpktoptions(control, &opt, priv)) != 0)
    523 			goto release;
    524 		in6p->in6p_outputopts = &opt;
    525 	}
    526 
    527 	if (addr6) {
    528 		laddr6 = in6p->in6p_laddr;
    529 		if (!IN6_IS_ADDR_ANY(&in6p->in6p_faddr)) {
    530 			error = EISCONN;
    531 			goto release;
    532 		}
    533 		/*
    534 		 * Must block input while temporarily connected.
    535 		 */
    536 		s = splsoftnet();
    537 		error = in6_pcbconnect(in6p, addr6);
    538 		if (error) {
    539 			splx(s);
    540 			goto release;
    541 		}
    542 	} else {
    543 		if (IN6_IS_ADDR_ANY(&in6p->in6p_faddr)) {
    544 			error = ENOTCONN;
    545 			goto release;
    546 		}
    547 	}
    548 	/*
    549 	 * Calculate data length and get a mbuf
    550 	 * for UDP and IP6 headers.
    551 	 */
    552 	M_PREPEND(m, sizeof(struct ip6_hdr) + sizeof(struct udphdr), M_DONTWAIT);
    553 	if (m == 0) {
    554 		error = ENOBUFS;
    555 		if (addr6)
    556 			splx(s);
    557 		goto release;
    558 	}
    559 
    560 	/*
    561 	 * Stuff checksum and output datagram.
    562 	 */
    563 	ip6 = mtod(m, struct ip6_hdr *);
    564 	ip6->ip6_flow	= in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK;
    565 	ip6->ip6_vfc 	= IPV6_VERSION;
    566 #if 0				/* ip6_plen will be filled in ip6_output. */
    567 	ip6->ip6_plen	= htons((u_short)plen);
    568 #endif
    569 	ip6->ip6_nxt	= IPPROTO_UDP;
    570 	ip6->ip6_hlim	= in6p->in6p_ip6.ip6_hlim; /* XXX */
    571 	ip6->ip6_src	= in6p->in6p_laddr;
    572 	ip6->ip6_dst	= in6p->in6p_faddr;
    573 
    574 	udp6 = (struct udphdr *)(ip6 + 1);
    575 	udp6->uh_sport = in6p->in6p_lport;
    576 	udp6->uh_dport = in6p->in6p_fport;
    577 	udp6->uh_ulen  = htons((u_short)plen);
    578 	udp6->uh_sum   = 0;
    579 
    580 	if ((udp6->uh_sum = in6_cksum(m, IPPROTO_UDP,
    581 					sizeof(struct ip6_hdr), plen)) == 0) {
    582 		udp6->uh_sum = 0xffff;
    583 	}
    584 
    585 	udp6stat.udp6s_opackets++;
    586 
    587 #ifdef IPSEC
    588 	m->m_pkthdr.rcvif = (struct ifnet *)in6p->in6p_socket;
    589 #endif /*IPSEC*/
    590 	error = ip6_output(m, in6p->in6p_outputopts, &in6p->in6p_route,
    591 			    0, in6p->in6p_moptions);
    592 
    593 	if (addr6) {
    594 		in6_pcbdisconnect(in6p);
    595 		in6p->in6p_laddr = laddr6;
    596 		splx(s);
    597 	}
    598 	goto releaseopt;
    599 
    600 release:
    601 	m_freem(m);
    602 
    603 releaseopt:
    604 	if (control) {
    605 		in6p->in6p_outputopts = stickyopt;
    606 		m_freem(control);
    607 	}
    608 	return(error);
    609 }
    610 
    611 extern	int udp6_sendspace;
    612 extern	int udp6_recvspace;
    613 
    614 int
    615 udp6_usrreq(so, req, m, addr6, control, p)
    616 	struct socket *so;
    617 	int req;
    618 	struct mbuf *m, *addr6, *control;
    619 	struct proc *p;
    620 {
    621 	struct	in6pcb *in6p = sotoin6pcb(so);
    622 	int	error = 0;
    623 	int	s;
    624 
    625 	/*
    626 	 * MAPPED_ADDR implementation info:
    627 	 *  Mapped addr support for PRU_CONTROL is not necessary.
    628 	 *  Because typical user of PRU_CONTROL is such as ifconfig,
    629 	 *  and they don't associate any addr to their socket.  Then
    630 	 *  socket family is only hint about the PRU_CONTROL'ed address
    631 	 *  family, especially when getting addrs from kernel.
    632 	 *  So AF_INET socket need to be used to control AF_INET addrs,
    633 	 *  and AF_INET6 socket for AF_INET6 addrs.
    634 	 */
    635 	if (req == PRU_CONTROL)
    636 		return(in6_control(so, (u_long)m, (caddr_t)addr6,
    637 				   (struct ifnet *)control, p));
    638 
    639 	if (in6p == NULL && req != PRU_ATTACH) {
    640 		error = EINVAL;
    641 		goto release;
    642 	}
    643 
    644 	switch (req) {
    645 	case PRU_ATTACH:
    646 		/*
    647 		 * MAPPED_ADDR implementation spec:
    648 		 *  Always attach for IPv6,
    649 		 *  and only when necessary for IPv4.
    650 		 */
    651 		if (in6p != NULL) {
    652 			error = EINVAL;
    653 			break;
    654 		}
    655 		s = splsoftnet();
    656 		error = in6_pcballoc(so, &udb6);
    657 		splx(s);
    658 		if (error)
    659 			break;
    660 		error = soreserve(so, udp6_sendspace, udp6_recvspace);
    661 		if (error)
    662 			break;
    663 		in6p = sotoin6pcb(so);
    664 		in6p->in6p_ip6.ip6_hlim = ip6_defhlim;
    665 		in6p->in6p_cksum = -1;	/* just to be sure */
    666 #ifdef IPSEC
    667 		if ((error = ipsec_init_policy(&in6p->in6p_sp)) != 0)
    668 			in6_pcbdetach(in6p);
    669 #endif /*IPSEC*/
    670 		break;
    671 
    672 	case PRU_DETACH:
    673 		udp6_detach(in6p);
    674 		break;
    675 
    676 	case PRU_BIND:
    677 		s = splsoftnet();
    678 		error = in6_pcbbind(in6p, addr6);
    679 		splx(s);
    680 		break;
    681 
    682 	case PRU_LISTEN:
    683 		error = EOPNOTSUPP;
    684 		break;
    685 
    686 	case PRU_CONNECT:
    687 		if (!IN6_IS_ADDR_ANY(&in6p->in6p_faddr)) {
    688 			error = EISCONN;
    689 			break;
    690 		}
    691 		s = splsoftnet();
    692 		error = in6_pcbconnect(in6p, addr6);
    693 		if (ip6_auto_flowlabel) {
    694 			in6p->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
    695 			in6p->in6p_flowinfo |=
    696 				(htonl(ip6_flow_seq++) & IPV6_FLOWLABEL_MASK);
    697 		}
    698 		splx(s);
    699 		if (error == 0)
    700 			soisconnected(so);
    701 		break;
    702 
    703 	case PRU_CONNECT2:
    704 		error = EOPNOTSUPP;
    705 		break;
    706 
    707 	case PRU_ACCEPT:
    708 		error = EOPNOTSUPP;
    709 		break;
    710 
    711 	case PRU_DISCONNECT:
    712 		if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
    713 			error = ENOTCONN;
    714 			break;
    715 		}
    716 		s = splsoftnet();
    717 		in6_pcbdisconnect(in6p);
    718 		bzero((caddr_t)&in6p->in6p_laddr, sizeof(in6p->in6p_laddr));
    719 		splx(s);
    720 		so->so_state &= ~SS_ISCONNECTED;		/* XXX */
    721 		break;
    722 
    723 	case PRU_SHUTDOWN:
    724 		socantsendmore(so);
    725 		break;
    726 
    727 	case PRU_SEND:
    728 		return(udp6_output(in6p, m, addr6, control));
    729 
    730 	case PRU_ABORT:
    731 		soisdisconnected(so);
    732 		udp6_detach(in6p);
    733 		break;
    734 
    735 	case PRU_SOCKADDR:
    736 		in6_setsockaddr(in6p, addr6);
    737 		break;
    738 
    739 	case PRU_PEERADDR:
    740 		in6_setpeeraddr(in6p, addr6);
    741 		break;
    742 
    743 	case PRU_SENSE:
    744 		/*
    745 		 * stat: don't bother with a blocksize
    746 		 */
    747 		return(0);
    748 
    749 	case PRU_SENDOOB:
    750 	case PRU_FASTTIMO:
    751 	case PRU_SLOWTIMO:
    752 	case PRU_PROTORCV:
    753 	case PRU_PROTOSEND:
    754 		error = EOPNOTSUPP;
    755 		break;
    756 
    757 	case PRU_RCVD:
    758 	case PRU_RCVOOB:
    759 		return(EOPNOTSUPP);	/* do not free mbuf's */
    760 
    761 	default:
    762 		panic("udp6_usrreq");
    763 	}
    764 
    765 release:
    766 	if (control) {
    767 		printf("udp control data unexpectedly retained\n");
    768 		m_freem(control);
    769 	}
    770 	if (m)
    771 		m_freem(m);
    772 	return(error);
    773 }
    774 
    775 static void
    776 udp6_detach(in6p)
    777 	struct in6pcb *in6p;
    778 {
    779 	int	s = splsoftnet();
    780 
    781 	if (in6p == udp6_last_in6pcb)
    782 		udp6_last_in6pcb = &udb6;
    783 	in6_pcbdetach(in6p);
    784 	splx(s);
    785 }
    786 
    787 #ifdef __bsdi__
    788 int *udp6_sysvars[] = UDP6CTL_VARS;
    789 
    790 int
    791 udp6_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
    792 	int	*name;
    793 	u_int	namelen;
    794 	void	*oldp;
    795 	size_t	*oldlenp;
    796 	void	*newp;
    797 	size_t	newlen;
    798 {
    799 	if (name[0] >= UDP6CTL_MAXID)
    800 		return (EOPNOTSUPP);
    801 	switch (name[0]) {
    802 	case UDP6CTL_STATS:
    803 		return sysctl_rdtrunc(oldp, oldlenp, newp, &udp6stat,
    804 		    sizeof(udp6stat));
    805 
    806 	default:
    807 		return (sysctl_int_arr(udp6_sysvars, name, namelen,
    808 		    oldp, oldlenp, newp, newlen));
    809 	}
    810 }
    811 #endif /*__bsdi__*/
    812 
    813 #ifdef __NetBSD__
    814 #include <vm/vm.h>
    815 #include <sys/sysctl.h>
    816 
    817 int
    818 udp6_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
    819 	int *name;
    820 	u_int namelen;
    821 	void *oldp;
    822 	size_t *oldlenp;
    823 	void *newp;
    824 	size_t newlen;
    825 {
    826 	/* All sysctl names at this level are terminal. */
    827 	if (namelen != 1)
    828 		return ENOTDIR;
    829 
    830 	switch (name[0]) {
    831 
    832 	case UDP6CTL_SENDMAX:
    833 		return sysctl_int(oldp, oldlenp, newp, newlen,
    834 		    &udp6_sendspace);
    835 	case UDP6CTL_RECVSPACE:
    836 		return sysctl_int(oldp, oldlenp, newp, newlen,
    837 		    &udp6_recvspace);
    838 	default:
    839 		return ENOPROTOOPT;
    840 	}
    841 	/* NOTREACHED */
    842 }
    843 #endif
    844