xref: /openbsd-src/sys/netinet/udp_usrreq.c (revision c0dd97bfcad3dab6c31ec12b9de1274fd2d2f993)
1 /*	$OpenBSD: udp_usrreq.c,v 1.241 2017/10/09 08:35:38 mpi Exp $	*/
2 /*	$NetBSD: udp_usrreq.c,v 1.28 1996/03/16 23:54:03 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1988, 1990, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
33  *
34  * NRL grants permission for redistribution and use in source and binary
35  * forms, with or without modification, of the software and documentation
36  * created at NRL provided that the following conditions are met:
37  *
38  * 1. Redistributions of source code must retain the above copyright
39  *    notice, this list of conditions and the following disclaimer.
40  * 2. Redistributions in binary form must reproduce the above copyright
41  *    notice, this list of conditions and the following disclaimer in the
42  *    documentation and/or other materials provided with the distribution.
43  * 3. All advertising materials mentioning features or use of this software
44  *    must display the following acknowledgements:
45  * 	This product includes software developed by the University of
46  * 	California, Berkeley and its contributors.
47  * 	This product includes software developed at the Information
48  * 	Technology Division, US Naval Research Laboratory.
49  * 4. Neither the name of the NRL nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
54  * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
55  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
56  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL NRL OR
57  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
58  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
59  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
60  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
61  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
62  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
63  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64  *
65  * The views and conclusions contained in the software and documentation
66  * are those of the authors and should not be interpreted as representing
67  * official policies, either expressed or implied, of the US Naval
68  * Research Laboratory (NRL).
69  */
70 
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/mbuf.h>
74 #include <sys/protosw.h>
75 #include <sys/socket.h>
76 #include <sys/socketvar.h>
77 #include <sys/sysctl.h>
78 #include <sys/domain.h>
79 
80 #include <net/if.h>
81 #include <net/if_var.h>
82 #include <net/if_media.h>
83 #include <net/route.h>
84 
85 #include <netinet/in.h>
86 #include <netinet/in_var.h>
87 #include <netinet/ip.h>
88 #include <netinet/in_pcb.h>
89 #include <netinet/ip_var.h>
90 #include <netinet/ip_icmp.h>
91 #include <netinet/udp.h>
92 #include <netinet/udp_var.h>
93 
94 #ifdef IPSEC
95 #include <netinet/ip_ipsp.h>
96 #include <netinet/ip_esp.h>
97 #endif
98 
99 #ifdef INET6
100 #include <netinet6/in6_var.h>
101 #include <netinet6/ip6_var.h>
102 #include <netinet6/ip6protosw.h>
103 #endif /* INET6 */
104 
105 #include "pf.h"
106 #if NPF > 0
107 #include <net/pfvar.h>
108 #endif
109 
110 #ifdef PIPEX
111 #include <netinet/if_ether.h>
112 #include <net/pipex.h>
113 #endif
114 
115 #include "vxlan.h"
116 #if NVXLAN > 0
117 #include <net/if_vxlan.h>
118 #endif
119 
120 /*
121  * UDP protocol implementation.
122  * Per RFC 768, August, 1980.
123  */
124 int	udpcksum = 1;
125 
126 u_int	udp_sendspace = 9216;		/* really max datagram size */
127 u_int	udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
128 					/* 40 1K datagrams */
129 
130 int *udpctl_vars[UDPCTL_MAXID] = UDPCTL_VARS;
131 
132 struct	inpcbtable udbtable;
133 struct	cpumem *udpcounters;
134 
135 int	udp_output(struct inpcb *, struct mbuf *, struct mbuf *, struct mbuf *);
136 void	udp_notify(struct inpcb *, int);
137 int	udp_sysctl_udpstat(void *, size_t *, void *);
138 
139 #ifndef	UDB_INITIAL_HASH_SIZE
140 #define	UDB_INITIAL_HASH_SIZE	128
141 #endif
142 
143 void
144 udp_init(void)
145 {
146 	udpcounters = counters_alloc(udps_ncounters);
147 	in_pcbinit(&udbtable, UDB_INITIAL_HASH_SIZE);
148 }
149 
150 int
151 udp_input(struct mbuf **mp, int *offp, int proto, int af)
152 {
153 	struct mbuf *m = *mp;
154 	int iphlen = *offp;
155 	struct ip *ip = NULL;
156 	struct udphdr *uh;
157 	struct inpcb *inp = NULL;
158 	struct mbuf *opts = NULL;
159 	struct ip save_ip;
160 	int len;
161 	u_int16_t savesum;
162 	union {
163 		struct sockaddr sa;
164 		struct sockaddr_in sin;
165 #ifdef INET6
166 		struct sockaddr_in6 sin6;
167 #endif /* INET6 */
168 	} srcsa, dstsa;
169 #ifdef INET6
170 	struct ip6_hdr *ip6 = NULL;
171 #endif /* INET6 */
172 #ifdef IPSEC
173 	struct m_tag *mtag;
174 	struct tdb_ident *tdbi;
175 	struct tdb *tdb;
176 	int error, protoff;
177 #endif /* IPSEC */
178 #if defined(IPSEC) || defined(PIPEX)
179 	u_int32_t ipsecflowinfo = 0;
180 #endif /* define(IPSEC) || defined(PIPEX) */
181 
182 	udpstat_inc(udps_ipackets);
183 
184 	IP6_EXTHDR_GET(uh, struct udphdr *, m, iphlen, sizeof(struct udphdr));
185 	if (!uh) {
186 		udpstat_inc(udps_hdrops);
187 		return IPPROTO_DONE;
188 	}
189 
190 	/* Check for illegal destination port 0 */
191 	if (uh->uh_dport == 0) {
192 		udpstat_inc(udps_noport);
193 		goto bad;
194 	}
195 
196 	/*
197 	 * Make mbuf data length reflect UDP length.
198 	 * If not enough data to reflect UDP length, drop.
199 	 */
200 	len = ntohs((u_int16_t)uh->uh_ulen);
201 	switch (af) {
202 	case AF_INET:
203 		if (m->m_pkthdr.len - iphlen != len) {
204 			if (len > (m->m_pkthdr.len - iphlen) ||
205 			    len < sizeof(struct udphdr)) {
206 				udpstat_inc(udps_badlen);
207 				goto bad;
208 			}
209 			m_adj(m, len - (m->m_pkthdr.len - iphlen));
210 		}
211 		ip = mtod(m, struct ip *);
212 		/*
213 		 * Save a copy of the IP header in case we want restore it
214 		 * for sending an ICMP error message in response.
215 		 */
216 		save_ip = *ip;
217 		break;
218 #ifdef INET6
219 	case AF_INET6:
220 		/* jumbograms */
221 		if (len == 0 && m->m_pkthdr.len - iphlen > 0xffff)
222 			len = m->m_pkthdr.len - iphlen;
223 		if (len != m->m_pkthdr.len - iphlen) {
224 			udpstat_inc(udps_badlen);
225 			goto bad;
226 		}
227 		ip6 = mtod(m, struct ip6_hdr *);
228 		break;
229 #endif /* INET6 */
230 	default:
231 		unhandled_af(af);
232 	}
233 
234 	/*
235 	 * Checksum extended UDP header and data.
236 	 * from W.R.Stevens: check incoming udp cksums even if
237 	 *	udpcksum is not set.
238 	 */
239 	savesum = uh->uh_sum;
240 	if (uh->uh_sum == 0) {
241 		udpstat_inc(udps_nosum);
242 #ifdef INET6
243 		/*
244 		 * In IPv6, the UDP checksum is ALWAYS used.
245 		 */
246 		if (ip6)
247 			goto bad;
248 #endif /* INET6 */
249 	} else {
250 		if ((m->m_pkthdr.csum_flags & M_UDP_CSUM_IN_OK) == 0) {
251 			if (m->m_pkthdr.csum_flags & M_UDP_CSUM_IN_BAD) {
252 				udpstat_inc(udps_badsum);
253 				goto bad;
254 			}
255 			udpstat_inc(udps_inswcsum);
256 
257 			if (ip)
258 				uh->uh_sum = in4_cksum(m, IPPROTO_UDP,
259 				    iphlen, len);
260 #ifdef INET6
261 			else if (ip6)
262 				uh->uh_sum = in6_cksum(m, IPPROTO_UDP,
263 				    iphlen, len);
264 #endif /* INET6 */
265 			if (uh->uh_sum != 0) {
266 				udpstat_inc(udps_badsum);
267 				goto bad;
268 			}
269 		}
270 	}
271 
272 #ifdef IPSEC
273 	if (udpencap_enable && udpencap_port &&
274 #if NPF > 0
275 	    !(m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) &&
276 #endif
277 	    uh->uh_dport == htons(udpencap_port)) {
278 		u_int32_t spi;
279 		int skip = iphlen + sizeof(struct udphdr);
280 
281 		if (m->m_pkthdr.len - skip < sizeof(u_int32_t)) {
282 			/* packet too short */
283 			m_freem(m);
284 			return IPPROTO_DONE;
285 		}
286 		m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
287 		/*
288 		 * decapsulate if the SPI is not zero, otherwise pass
289 		 * to userland
290 		 */
291 		if (spi != 0) {
292 			if ((m = *mp = m_pullup(m, skip)) == NULL) {
293 				udpstat_inc(udps_hdrops);
294 				return IPPROTO_DONE;
295 			}
296 
297 			/* remove the UDP header */
298 			bcopy(mtod(m, u_char *),
299 			    mtod(m, u_char *) + sizeof(struct udphdr), iphlen);
300 			m_adj(m, sizeof(struct udphdr));
301 			skip -= sizeof(struct udphdr);
302 
303 			espstat.esps_udpencin++;
304 			protoff = af == AF_INET ? offsetof(struct ip, ip_p) :
305 			    offsetof(struct ip6_hdr, ip6_nxt);
306 			ipsec_common_input(m, skip, protoff,
307 			    af, IPPROTO_ESP, 1);
308 			return IPPROTO_DONE;
309 		}
310 	}
311 #endif
312 
313 	switch (af) {
314 	case AF_INET:
315 		bzero(&srcsa, sizeof(struct sockaddr_in));
316 		srcsa.sin.sin_len = sizeof(struct sockaddr_in);
317 		srcsa.sin.sin_family = AF_INET;
318 		srcsa.sin.sin_port = uh->uh_sport;
319 		srcsa.sin.sin_addr = ip->ip_src;
320 
321 		bzero(&dstsa, sizeof(struct sockaddr_in));
322 		dstsa.sin.sin_len = sizeof(struct sockaddr_in);
323 		dstsa.sin.sin_family = AF_INET;
324 		dstsa.sin.sin_port = uh->uh_dport;
325 		dstsa.sin.sin_addr = ip->ip_dst;
326 		break;
327 #ifdef INET6
328 	case AF_INET6:
329 		bzero(&srcsa, sizeof(struct sockaddr_in6));
330 		srcsa.sin6.sin6_len = sizeof(struct sockaddr_in6);
331 		srcsa.sin6.sin6_family = AF_INET6;
332 		srcsa.sin6.sin6_port = uh->uh_sport;
333 #if 0 /*XXX inbound flowinfo */
334 		srcsa.sin6.sin6_flowinfo = htonl(0x0fffffff) & ip6->ip6_flow;
335 #endif
336 		/* KAME hack: recover scopeid */
337 		in6_recoverscope(&srcsa.sin6, &ip6->ip6_src);
338 
339 		bzero(&dstsa, sizeof(struct sockaddr_in6));
340 		dstsa.sin6.sin6_len = sizeof(struct sockaddr_in6);
341 		dstsa.sin6.sin6_family = AF_INET6;
342 		dstsa.sin6.sin6_port = uh->uh_dport;
343 #if 0 /*XXX inbound flowinfo */
344 		dstsa.sin6.sin6_flowinfo = htonl(0x0fffffff) & ip6->ip6_flow;
345 #endif
346 		/* KAME hack: recover scopeid */
347 		in6_recoverscope(&dstsa.sin6, &ip6->ip6_dst);
348 		break;
349 #endif /* INET6 */
350 	}
351 
352 #if NVXLAN > 0
353 	if (vxlan_enable > 0 &&
354 #if NPF > 0
355 	    !(m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) &&
356 #endif
357 	    vxlan_lookup(m, uh, iphlen, &srcsa.sa, &dstsa.sa) != 0)
358 		return IPPROTO_DONE;
359 #endif
360 
361 	if (m->m_flags & (M_BCAST|M_MCAST)) {
362 		struct inpcb *last;
363 		/*
364 		 * Deliver a multicast or broadcast datagram to *all* sockets
365 		 * for which the local and remote addresses and ports match
366 		 * those of the incoming datagram.  This allows more than
367 		 * one process to receive multi/broadcasts on the same port.
368 		 * (This really ought to be done for unicast datagrams as
369 		 * well, but that would cause problems with existing
370 		 * applications that open both address-specific sockets and
371 		 * a wildcard socket listening to the same port -- they would
372 		 * end up receiving duplicates of every unicast datagram.
373 		 * Those applications open the multiple sockets to overcome an
374 		 * inadequacy of the UDP socket interface, but for backwards
375 		 * compatibility we avoid the problem here rather than
376 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
377 		 */
378 
379 		iphlen += sizeof(struct udphdr);
380 
381 		/*
382 		 * Locate pcb(s) for datagram.
383 		 * (Algorithm copied from raw_intr().)
384 		 */
385 		last = NULL;
386 		TAILQ_FOREACH(inp, &udbtable.inpt_queue, inp_queue) {
387 			if (inp->inp_socket->so_state & SS_CANTRCVMORE)
388 				continue;
389 #ifdef INET6
390 			/* don't accept it if AF does not match */
391 			if (ip6 && !(inp->inp_flags & INP_IPV6))
392 				continue;
393 			if (!ip6 && (inp->inp_flags & INP_IPV6))
394 				continue;
395 #endif
396 			if (rtable_l2(inp->inp_rtableid) !=
397 			    rtable_l2(m->m_pkthdr.ph_rtableid))
398 				continue;
399 			if (inp->inp_lport != uh->uh_dport)
400 				continue;
401 #ifdef INET6
402 			if (ip6) {
403 				if (inp->inp_ip6_minhlim &&
404 				    inp->inp_ip6_minhlim > ip6->ip6_hlim)
405 					continue;
406 				if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6))
407 					if (!IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6,
408 					    &ip6->ip6_dst))
409 						continue;
410 			} else
411 #endif /* INET6 */
412 			{
413 				if (inp->inp_ip_minttl &&
414 				    inp->inp_ip_minttl > ip->ip_ttl)
415 					continue;
416 
417 				if (inp->inp_laddr.s_addr != INADDR_ANY) {
418 					if (inp->inp_laddr.s_addr !=
419 					    ip->ip_dst.s_addr)
420 						continue;
421 				}
422 			}
423 #ifdef INET6
424 			if (ip6) {
425 				if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
426 					if (!IN6_ARE_ADDR_EQUAL(&inp->inp_faddr6,
427 					    &ip6->ip6_src) ||
428 					    inp->inp_fport != uh->uh_sport)
429 						continue;
430 			} else
431 #endif /* INET6 */
432 			if (inp->inp_faddr.s_addr != INADDR_ANY) {
433 				if (inp->inp_faddr.s_addr !=
434 				    ip->ip_src.s_addr ||
435 				    inp->inp_fport != uh->uh_sport)
436 					continue;
437 			}
438 
439 			if (last != NULL) {
440 				struct mbuf *n;
441 
442 				n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
443 				if (n != NULL) {
444 #ifdef INET6
445 					if (ip6 && (last->inp_flags &
446 					    IN6P_CONTROLOPTS ||
447 					    last->inp_socket->so_options &
448 					    SO_TIMESTAMP))
449 						ip6_savecontrol(last, n, &opts);
450 #endif /* INET6 */
451 					if (ip && (last->inp_flags &
452 					    INP_CONTROLOPTS ||
453 					    last->inp_socket->so_options &
454 					    SO_TIMESTAMP))
455 						ip_savecontrol(last, &opts,
456 						    ip, n);
457 
458 					m_adj(n, iphlen);
459 					if (sbappendaddr(last->inp_socket,
460 					    &last->inp_socket->so_rcv,
461 					    &srcsa.sa, n, opts) == 0) {
462 						m_freem(n);
463 						m_freem(opts);
464 						udpstat_inc(udps_fullsock);
465 					} else
466 						sorwakeup(last->inp_socket);
467 					opts = NULL;
468 				}
469 			}
470 			last = inp;
471 			/*
472 			 * Don't look for additional matches if this one does
473 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
474 			 * socket options set.  This heuristic avoids searching
475 			 * through all pcbs in the common case of a non-shared
476 			 * port.  It assumes that an application will never
477 			 * clear these options after setting them.
478 			 */
479 			if ((last->inp_socket->so_options & (SO_REUSEPORT |
480 			    SO_REUSEADDR)) == 0)
481 				break;
482 		}
483 
484 		if (last == NULL) {
485 			/*
486 			 * No matching pcb found; discard datagram.
487 			 * (No need to send an ICMP Port Unreachable
488 			 * for a broadcast or multicast datgram.)
489 			 */
490 			udpstat_inc(udps_noportbcast);
491 			goto bad;
492 		}
493 
494 #ifdef INET6
495 		if (ip6 && (last->inp_flags & IN6P_CONTROLOPTS ||
496 		    last->inp_socket->so_options & SO_TIMESTAMP))
497 			ip6_savecontrol(last, m, &opts);
498 #endif /* INET6 */
499 		if (ip && (last->inp_flags & INP_CONTROLOPTS ||
500 		    last->inp_socket->so_options & SO_TIMESTAMP))
501 			ip_savecontrol(last, &opts, ip, m);
502 
503 		m_adj(m, iphlen);
504 		if (sbappendaddr(last->inp_socket, &last->inp_socket->so_rcv,
505 		    &srcsa.sa, m, opts) == 0) {
506 			udpstat_inc(udps_fullsock);
507 			goto bad;
508 		}
509 		sorwakeup(last->inp_socket);
510 		return IPPROTO_DONE;
511 	}
512 	/*
513 	 * Locate pcb for datagram.
514 	 */
515 #if NPF > 0 && 0  /* currently disabled */
516 	inp = pf_inp_lookup(m);
517 #endif
518 	if (inp == NULL) {
519 #ifdef INET6
520 		if (ip6)
521 			inp = in6_pcbhashlookup(&udbtable, &ip6->ip6_src,
522 			    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
523 			    m->m_pkthdr.ph_rtableid);
524 		else
525 #endif /* INET6 */
526 		inp = in_pcbhashlookup(&udbtable, ip->ip_src, uh->uh_sport,
527 		    ip->ip_dst, uh->uh_dport, m->m_pkthdr.ph_rtableid);
528 	}
529 	if (inp == 0) {
530 		int	inpl_reverse = 0;
531 		if (m->m_pkthdr.pf.flags & PF_TAG_TRANSLATE_LOCALHOST)
532 			inpl_reverse = 1;
533 		udpstat_inc(udps_pcbhashmiss);
534 #ifdef INET6
535 		if (ip6) {
536 			inp = in6_pcblookup_listen(&udbtable,
537 			    &ip6->ip6_dst, uh->uh_dport, inpl_reverse, m,
538 			    m->m_pkthdr.ph_rtableid);
539 		} else
540 #endif /* INET6 */
541 		inp = in_pcblookup_listen(&udbtable,
542 		    ip->ip_dst, uh->uh_dport, inpl_reverse, m,
543 		    m->m_pkthdr.ph_rtableid);
544 		if (inp == 0) {
545 			udpstat_inc(udps_noport);
546 			if (m->m_flags & (M_BCAST | M_MCAST)) {
547 				udpstat_inc(udps_noportbcast);
548 				goto bad;
549 			}
550 #ifdef INET6
551 			if (ip6) {
552 				uh->uh_sum = savesum;
553 				icmp6_error(m, ICMP6_DST_UNREACH,
554 				    ICMP6_DST_UNREACH_NOPORT,0);
555 			} else
556 #endif /* INET6 */
557 			{
558 				*ip = save_ip;
559 				uh->uh_sum = savesum;
560 				icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT,
561 				    0, 0);
562 			}
563 			return IPPROTO_DONE;
564 		}
565 	}
566 	KASSERT(sotoinpcb(inp->inp_socket) == inp);
567 
568 #ifdef INET6
569 	if (ip6 && inp->inp_ip6_minhlim &&
570 	    inp->inp_ip6_minhlim > ip6->ip6_hlim) {
571 		goto bad;
572 	} else
573 #endif
574 	if (ip && inp->inp_ip_minttl &&
575 	    inp->inp_ip_minttl > ip->ip_ttl) {
576 		goto bad;
577 	}
578 
579 #if NPF > 0
580 	if (inp->inp_socket->so_state & SS_ISCONNECTED)
581 		pf_inp_link(m, inp);
582 #endif
583 
584 #ifdef IPSEC
585 	mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
586 	if (mtag != NULL) {
587 		tdbi = (struct tdb_ident *)(mtag + 1);
588 		tdb = gettdb(tdbi->rdomain, tdbi->spi,
589 		    &tdbi->dst, tdbi->proto);
590 	} else
591 		tdb = NULL;
592 	ipsp_spd_lookup(m, af, iphlen, &error,
593 	    IPSP_DIRECTION_IN, tdb, inp, 0);
594 	if (error) {
595 		udpstat_inc(udps_nosec);
596 		goto bad;
597 	}
598 	/* create ipsec options while we know that tdb cannot be modified */
599 	if (tdb && tdb->tdb_ids)
600 		ipsecflowinfo = tdb->tdb_ids->id_flow;
601 #endif /*IPSEC */
602 
603 	opts = NULL;
604 #ifdef INET6
605 	if (ip6 && (inp->inp_flags & IN6P_CONTROLOPTS ||
606 	    inp->inp_socket->so_options & SO_TIMESTAMP))
607 		ip6_savecontrol(inp, m, &opts);
608 #endif /* INET6 */
609 	if (ip && (inp->inp_flags & INP_CONTROLOPTS ||
610 	    inp->inp_socket->so_options & SO_TIMESTAMP))
611 		ip_savecontrol(inp, &opts, ip, m);
612 #ifdef INET6
613 	if (ip6 && (inp->inp_flags & IN6P_RECVDSTPORT)) {
614 		struct mbuf **mp = &opts;
615 
616 		while (*mp)
617 			mp = &(*mp)->m_next;
618 		*mp = sbcreatecontrol((caddr_t)&uh->uh_dport, sizeof(u_int16_t),
619 		    IPV6_RECVDSTPORT, IPPROTO_IPV6);
620 	}
621 #endif /* INET6 */
622 	if (ip && (inp->inp_flags & INP_RECVDSTPORT)) {
623 		struct mbuf **mp = &opts;
624 
625 		while (*mp)
626 			mp = &(*mp)->m_next;
627 		*mp = sbcreatecontrol((caddr_t)&uh->uh_dport, sizeof(u_int16_t),
628 		    IP_RECVDSTPORT, IPPROTO_IP);
629 	}
630 #ifdef IPSEC
631 	if (ipsecflowinfo && (inp->inp_flags & INP_IPSECFLOWINFO)) {
632 		struct mbuf **mp = &opts;
633 
634 		while (*mp)
635 			mp = &(*mp)->m_next;
636 		*mp = sbcreatecontrol((caddr_t)&ipsecflowinfo,
637 		    sizeof(u_int32_t), IP_IPSECFLOWINFO, IPPROTO_IP);
638 	}
639 #endif
640 #ifdef PIPEX
641 	if (pipex_enable && inp->inp_pipex) {
642 		struct pipex_session *session;
643 		int off = iphlen + sizeof(struct udphdr);
644 		if ((session = pipex_l2tp_lookup_session(m, off)) != NULL) {
645 			if ((m = *mp = pipex_l2tp_input(m, off, session,
646 			    ipsecflowinfo)) == NULL) {
647 				m_freem(opts);
648 				/* the packet is handled by PIPEX */
649 				return IPPROTO_DONE;
650 			}
651 		}
652 	}
653 #endif
654 
655 	iphlen += sizeof(struct udphdr);
656 	m_adj(m, iphlen);
657 	if (sbappendaddr(inp->inp_socket, &inp->inp_socket->so_rcv, &srcsa.sa,
658 	    m, opts) == 0) {
659 		udpstat_inc(udps_fullsock);
660 		goto bad;
661 	}
662 	sorwakeup(inp->inp_socket);
663 	return IPPROTO_DONE;
664 bad:
665 	m_freem(m);
666 	m_freem(opts);
667 	return IPPROTO_DONE;
668 }
669 
670 /*
671  * Notify a udp user of an asynchronous error;
672  * just wake up so that he can collect error status.
673  */
674 void
675 udp_notify(struct inpcb *inp, int errno)
676 {
677 	inp->inp_socket->so_error = errno;
678 	sorwakeup(inp->inp_socket);
679 	sowwakeup(inp->inp_socket);
680 }
681 
682 #ifdef INET6
683 void
684 udp6_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *d)
685 {
686 	struct udphdr uh;
687 	struct sockaddr_in6 sa6;
688 	struct ip6_hdr *ip6;
689 	struct mbuf *m;
690 	int off;
691 	void *cmdarg;
692 	struct ip6ctlparam *ip6cp = NULL;
693 	struct udp_portonly {
694 		u_int16_t uh_sport;
695 		u_int16_t uh_dport;
696 	} *uhp;
697 	void (*notify)(struct inpcb *, int) = udp_notify;
698 
699 	if (sa == NULL)
700 		return;
701 	if (sa->sa_family != AF_INET6 ||
702 	    sa->sa_len != sizeof(struct sockaddr_in6))
703 		return;
704 
705 	if ((unsigned)cmd >= PRC_NCMDS)
706 		return;
707 	if (PRC_IS_REDIRECT(cmd))
708 		notify = in_rtchange, d = NULL;
709 	else if (cmd == PRC_HOSTDEAD)
710 		d = NULL;
711 	else if (cmd == PRC_MSGSIZE)
712 		; /* special code is present, see below */
713 	else if (inet6ctlerrmap[cmd] == 0)
714 		return;
715 
716 	/* if the parameter is from icmp6, decode it. */
717 	if (d != NULL) {
718 		ip6cp = (struct ip6ctlparam *)d;
719 		m = ip6cp->ip6c_m;
720 		ip6 = ip6cp->ip6c_ip6;
721 		off = ip6cp->ip6c_off;
722 		cmdarg = ip6cp->ip6c_cmdarg;
723 	} else {
724 		m = NULL;
725 		ip6 = NULL;
726 		cmdarg = NULL;
727 		/* XXX: translate addresses into internal form */
728 		sa6 = *satosin6(sa);
729 		if (in6_embedscope(&sa6.sin6_addr, &sa6, NULL)) {
730 			/* should be impossible */
731 			return;
732 		}
733 	}
734 
735 	if (ip6cp && ip6cp->ip6c_finaldst) {
736 		bzero(&sa6, sizeof(sa6));
737 		sa6.sin6_family = AF_INET6;
738 		sa6.sin6_len = sizeof(sa6);
739 		sa6.sin6_addr = *ip6cp->ip6c_finaldst;
740 		/* XXX: assuming M is valid in this case */
741 		sa6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
742 		    ip6cp->ip6c_finaldst);
743 		if (in6_embedscope(ip6cp->ip6c_finaldst, &sa6, NULL)) {
744 			/* should be impossible */
745 			return;
746 		}
747 	} else {
748 		/* XXX: translate addresses into internal form */
749 		sa6 = *satosin6(sa);
750 		if (in6_embedscope(&sa6.sin6_addr, &sa6, NULL)) {
751 			/* should be impossible */
752 			return;
753 		}
754 	}
755 
756 	if (ip6) {
757 		/*
758 		 * XXX: We assume that when IPV6 is non NULL,
759 		 * M and OFF are valid.
760 		 */
761 		struct sockaddr_in6 sa6_src;
762 
763 		/* check if we can safely examine src and dst ports */
764 		if (m->m_pkthdr.len < off + sizeof(*uhp))
765 			return;
766 
767 		bzero(&uh, sizeof(uh));
768 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
769 
770 		bzero(&sa6_src, sizeof(sa6_src));
771 		sa6_src.sin6_family = AF_INET6;
772 		sa6_src.sin6_len = sizeof(sa6_src);
773 		sa6_src.sin6_addr = ip6->ip6_src;
774 		sa6_src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
775 		    &ip6->ip6_src);
776 		if (in6_embedscope(&sa6_src.sin6_addr, &sa6_src, NULL)) {
777 			/* should be impossible */
778 			return;
779 		}
780 
781 		if (cmd == PRC_MSGSIZE) {
782 			int valid = 0;
783 
784 			/*
785 			 * Check to see if we have a valid UDP socket
786 			 * corresponding to the address in the ICMPv6 message
787 			 * payload.
788 			 */
789 			if (in6_pcbhashlookup(&udbtable, &sa6.sin6_addr,
790 			    uh.uh_dport, &sa6_src.sin6_addr, uh.uh_sport,
791 			    rdomain))
792 				valid = 1;
793 #if 0
794 			/*
795 			 * As the use of sendto(2) is fairly popular,
796 			 * we may want to allow non-connected pcb too.
797 			 * But it could be too weak against attacks...
798 			 * We should at least check if the local address (= s)
799 			 * is really ours.
800 			 */
801 			else if (in6_pcblookup_listen(&udbtable,
802 			    &sa6_src.sin6_addr, uh.uh_sport, 0,
803 			    rdomain))
804 				valid = 1;
805 #endif
806 
807 			/*
808 			 * Depending on the value of "valid" and routing table
809 			 * size (mtudisc_{hi,lo}wat), we will:
810 			 * - recalculate the new MTU and create the
811 			 *   corresponding routing entry, or
812 			 * - ignore the MTU change notification.
813 			 */
814 			icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
815 
816 			/*
817 			 * regardless of if we called icmp6_mtudisc_update(),
818 			 * we need to call in6_pcbnotify(), to notify path
819 			 * MTU change to the userland (2292bis-02), because
820 			 * some unconnected sockets may share the same
821 			 * destination and want to know the path MTU.
822 			 */
823 		}
824 
825 		(void) in6_pcbnotify(&udbtable, &sa6, uh.uh_dport,
826 		    &sa6_src, uh.uh_sport, rdomain, cmd, cmdarg, notify);
827 	} else {
828 		(void) in6_pcbnotify(&udbtable, &sa6, 0,
829 		    &sa6_any, 0, rdomain, cmd, cmdarg, notify);
830 	}
831 }
832 #endif
833 
834 void
835 udp_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v)
836 {
837 	struct ip *ip = v;
838 	struct udphdr *uhp;
839 	struct in_addr faddr;
840 	struct inpcb *inp;
841 	void (*notify)(struct inpcb *, int) = udp_notify;
842 	int errno;
843 
844 	if (sa == NULL)
845 		return;
846 	if (sa->sa_family != AF_INET ||
847 	    sa->sa_len != sizeof(struct sockaddr_in))
848 		return;
849 	faddr = satosin(sa)->sin_addr;
850 	if (faddr.s_addr == INADDR_ANY)
851 		return;
852 
853 	if ((unsigned)cmd >= PRC_NCMDS)
854 		return;
855 	errno = inetctlerrmap[cmd];
856 	if (PRC_IS_REDIRECT(cmd))
857 		notify = in_rtchange, ip = 0;
858 	else if (cmd == PRC_HOSTDEAD)
859 		ip = 0;
860 	else if (errno == 0)
861 		return;
862 	if (ip) {
863 		uhp = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
864 
865 #ifdef IPSEC
866 		/* PMTU discovery for udpencap */
867 		if (cmd == PRC_MSGSIZE && ip_mtudisc && udpencap_enable &&
868 		    udpencap_port && uhp->uh_sport == htons(udpencap_port)) {
869 			udpencap_ctlinput(cmd, sa, rdomain, v);
870 			return;
871 		}
872 #endif
873 		inp = in_pcbhashlookup(&udbtable,
874 		    ip->ip_dst, uhp->uh_dport, ip->ip_src, uhp->uh_sport,
875 		    rdomain);
876 		if (inp && inp->inp_socket != NULL)
877 			notify(inp, errno);
878 	} else
879 		in_pcbnotifyall(&udbtable, sa, rdomain, errno, notify);
880 }
881 
882 int
883 udp_output(struct inpcb *inp, struct mbuf *m, struct mbuf *addr,
884     struct mbuf *control)
885 {
886 	struct sockaddr_in *sin = NULL;
887 	struct udpiphdr *ui;
888 	u_int32_t ipsecflowinfo = 0;
889 	struct sockaddr_in src_sin;
890 	int len = m->m_pkthdr.len;
891 	struct in_addr *laddr;
892 	int error = 0;
893 
894 #ifdef DIAGNOSTIC
895 	if ((inp->inp_flags & INP_IPV6) != 0)
896 		panic("IPv6 inpcb to %s", __func__);
897 #endif
898 
899 	/*
900 	 * Compute the packet length of the IP header, and
901 	 * punt if the length looks bogus.
902 	 */
903 	if ((len + sizeof(struct udpiphdr)) > IP_MAXPACKET) {
904 		error = EMSGSIZE;
905 		goto release;
906 	}
907 
908 	memset(&src_sin, 0, sizeof(src_sin));
909 
910 	if (control) {
911 		u_int clen;
912 		struct cmsghdr *cm;
913 		caddr_t cmsgs;
914 
915 		/*
916 		 * XXX: Currently, we assume all the optional information is
917 		 * stored in a single mbuf.
918 		 */
919 		if (control->m_next) {
920 			error = EINVAL;
921 			goto release;
922 		}
923 
924 		clen = control->m_len;
925 		cmsgs = mtod(control, caddr_t);
926 		do {
927 			if (clen < CMSG_LEN(0)) {
928 				error = EINVAL;
929 				goto release;
930 			}
931 			cm = (struct cmsghdr *)cmsgs;
932 			if (cm->cmsg_len < CMSG_LEN(0) ||
933 			    CMSG_ALIGN(cm->cmsg_len) > clen) {
934 				error = EINVAL;
935 				goto release;
936 			}
937 #ifdef IPSEC
938 			if ((inp->inp_flags & INP_IPSECFLOWINFO) != 0 &&
939 			    cm->cmsg_len == CMSG_LEN(sizeof(ipsecflowinfo)) &&
940 			    cm->cmsg_level == IPPROTO_IP &&
941 			    cm->cmsg_type == IP_IPSECFLOWINFO) {
942 				ipsecflowinfo = *(u_int32_t *)CMSG_DATA(cm);
943 			} else
944 #endif
945 			if (cm->cmsg_len == CMSG_LEN(sizeof(struct in_addr)) &&
946 			    cm->cmsg_level == IPPROTO_IP &&
947 			    cm->cmsg_type == IP_SENDSRCADDR) {
948 				memcpy(&src_sin.sin_addr, CMSG_DATA(cm),
949 				    sizeof(struct in_addr));
950 				src_sin.sin_family = AF_INET;
951 				src_sin.sin_len = sizeof(src_sin);
952 				/* no check on reuse when sin->sin_port == 0 */
953 				if ((error = in_pcbaddrisavail(inp, &src_sin,
954 				    0, curproc)))
955 					goto release;
956 			}
957 			clen -= CMSG_ALIGN(cm->cmsg_len);
958 			cmsgs += CMSG_ALIGN(cm->cmsg_len);
959 		} while (clen);
960 	}
961 
962 	if (addr) {
963 		if ((error = in_nam2sin(addr, &sin)))
964 			goto release;
965 		if (sin->sin_port == 0) {
966 			error = EADDRNOTAVAIL;
967 			goto release;
968 		}
969 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
970 			error = EISCONN;
971 			goto release;
972 		}
973 		error = in_pcbselsrc(&laddr, sin, inp);
974 		if (error)
975 			goto release;
976 
977 		if (inp->inp_lport == 0) {
978 			error = in_pcbbind(inp, NULL, curproc);
979 			if (error)
980 				goto release;
981 		}
982 
983 		if (src_sin.sin_len > 0 &&
984 		    src_sin.sin_addr.s_addr != INADDR_ANY &&
985 		    src_sin.sin_addr.s_addr != inp->inp_laddr.s_addr) {
986 			src_sin.sin_port = inp->inp_lport;
987 			if (inp->inp_laddr.s_addr != INADDR_ANY &&
988 			    (error =
989 			    in_pcbaddrisavail(inp, &src_sin, 0, curproc)))
990 				goto release;
991 			laddr = &src_sin.sin_addr;
992 		}
993 	} else {
994 		if (inp->inp_faddr.s_addr == INADDR_ANY) {
995 			error = ENOTCONN;
996 			goto release;
997 		}
998 		laddr = &inp->inp_laddr;
999 	}
1000 
1001 	/*
1002 	 * Calculate data length and get a mbuf
1003 	 * for UDP and IP headers.
1004 	 */
1005 	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
1006 	if (m == NULL) {
1007 		error = ENOBUFS;
1008 		goto bail;
1009 	}
1010 
1011 	/*
1012 	 * Fill in mbuf with extended UDP header
1013 	 * and addresses and length put into network format.
1014 	 */
1015 	ui = mtod(m, struct udpiphdr *);
1016 	bzero(ui->ui_x1, sizeof ui->ui_x1);
1017 	ui->ui_pr = IPPROTO_UDP;
1018 	ui->ui_len = htons((u_int16_t)len + sizeof (struct udphdr));
1019 	ui->ui_src = *laddr;
1020 	ui->ui_dst = sin ? sin->sin_addr : inp->inp_faddr;
1021 	ui->ui_sport = inp->inp_lport;
1022 	ui->ui_dport = sin ? sin->sin_port : inp->inp_fport;
1023 	ui->ui_ulen = ui->ui_len;
1024 	((struct ip *)ui)->ip_len = htons(sizeof (struct udpiphdr) + len);
1025 	((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl;
1026 	((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos;
1027 	if (udpcksum)
1028 		m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT;
1029 
1030 	udpstat_inc(udps_opackets);
1031 
1032 	/* force routing table */
1033 	m->m_pkthdr.ph_rtableid = inp->inp_rtableid;
1034 
1035 #if NPF > 0
1036 	if (inp->inp_socket->so_state & SS_ISCONNECTED)
1037 		m->m_pkthdr.pf.inp = inp;
1038 #endif
1039 
1040 	error = ip_output(m, inp->inp_options, &inp->inp_route,
1041 	    (inp->inp_socket->so_options & SO_BROADCAST), inp->inp_moptions,
1042 	    inp, ipsecflowinfo);
1043 	if (error == EACCES)	/* translate pf(4) error for userland */
1044 		error = EHOSTUNREACH;
1045 
1046 bail:
1047 	m_freem(control);
1048 	return (error);
1049 
1050 release:
1051 	m_freem(m);
1052 	goto bail;
1053 }
1054 
1055 /*ARGSUSED*/
1056 int
1057 udp_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *addr,
1058     struct mbuf *control, struct proc *p)
1059 {
1060 	struct inpcb *inp;
1061 	int error = 0;
1062 
1063 	soassertlocked(so);
1064 
1065 	if (req == PRU_CONTROL) {
1066 #ifdef INET6
1067 		if (sotopf(so) == PF_INET6)
1068 			return (in6_control(so, (u_long)m, (caddr_t)addr,
1069 			    (struct ifnet *)control));
1070 		else
1071 #endif /* INET6 */
1072 			return (in_control(so, (u_long)m, (caddr_t)addr,
1073 			    (struct ifnet *)control));
1074 	}
1075 
1076 	inp = sotoinpcb(so);
1077 	if (inp == NULL) {
1078 		error = EINVAL;
1079 		goto release;
1080 	}
1081 
1082 	/*
1083 	 * Note: need to block udp_input while changing
1084 	 * the udp pcb queue and/or pcb addresses.
1085 	 */
1086 	switch (req) {
1087 
1088 	case PRU_DETACH:
1089 		in_pcbdetach(inp);
1090 		break;
1091 
1092 	case PRU_BIND:
1093 		error = in_pcbbind(inp, addr, p);
1094 		break;
1095 
1096 	case PRU_LISTEN:
1097 		error = EOPNOTSUPP;
1098 		break;
1099 
1100 	case PRU_CONNECT:
1101 #ifdef INET6
1102 		if (inp->inp_flags & INP_IPV6) {
1103 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6)) {
1104 				error = EISCONN;
1105 				break;
1106 			}
1107 			error = in6_pcbconnect(inp, addr);
1108 		} else
1109 #endif /* INET6 */
1110 		{
1111 			if (inp->inp_faddr.s_addr != INADDR_ANY) {
1112 				error = EISCONN;
1113 				break;
1114 			}
1115 			error = in_pcbconnect(inp, addr);
1116 		}
1117 
1118 		if (error == 0)
1119 			soisconnected(so);
1120 		break;
1121 
1122 	case PRU_CONNECT2:
1123 		error = EOPNOTSUPP;
1124 		break;
1125 
1126 	case PRU_ACCEPT:
1127 		error = EOPNOTSUPP;
1128 		break;
1129 
1130 	case PRU_DISCONNECT:
1131 #ifdef INET6
1132 		if (inp->inp_flags & INP_IPV6) {
1133 			if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6)) {
1134 				error = ENOTCONN;
1135 				break;
1136 			}
1137 		} else
1138 #endif /* INET6 */
1139 		{
1140 			if (inp->inp_faddr.s_addr == INADDR_ANY) {
1141 				error = ENOTCONN;
1142 				break;
1143 			}
1144 		}
1145 
1146 #ifdef INET6
1147 		if (inp->inp_flags & INP_IPV6)
1148 			inp->inp_laddr6 = in6addr_any;
1149 		else
1150 #endif /* INET6 */
1151 			inp->inp_laddr.s_addr = INADDR_ANY;
1152 		in_pcbdisconnect(inp);
1153 
1154 		so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1155 		break;
1156 
1157 	case PRU_SHUTDOWN:
1158 		socantsendmore(so);
1159 		break;
1160 
1161 	case PRU_SEND:
1162 #ifdef PIPEX
1163 		if (inp->inp_pipex) {
1164 			struct pipex_session *session;
1165 
1166 			if (addr != NULL)
1167 				session =
1168 				    pipex_l2tp_userland_lookup_session(m,
1169 					mtod(addr, struct sockaddr *));
1170 			else
1171 #ifdef INET6
1172 			if (inp->inp_flags & INP_IPV6)
1173 				session =
1174 				    pipex_l2tp_userland_lookup_session_ipv6(
1175 					m, inp->inp_faddr6);
1176 			else
1177 #endif
1178 				session =
1179 				    pipex_l2tp_userland_lookup_session_ipv4(
1180 					m, inp->inp_faddr);
1181 			if (session != NULL)
1182 				if ((m = pipex_l2tp_userland_output(
1183 				    m, session)) == NULL) {
1184 					error = ENOMEM;
1185 					goto release;
1186 				}
1187 		}
1188 #endif
1189 
1190 #ifdef INET6
1191 		if (inp->inp_flags & INP_IPV6)
1192 			error = udp6_output(inp, m, addr, control);
1193 		else
1194 #endif
1195 			error = udp_output(inp, m, addr, control);
1196 		return (error);
1197 
1198 	case PRU_ABORT:
1199 		soisdisconnected(so);
1200 		in_pcbdetach(inp);
1201 		break;
1202 
1203 	case PRU_SOCKADDR:
1204 #ifdef INET6
1205 		if (inp->inp_flags & INP_IPV6)
1206 			in6_setsockaddr(inp, addr);
1207 		else
1208 #endif /* INET6 */
1209 			in_setsockaddr(inp, addr);
1210 		break;
1211 
1212 	case PRU_PEERADDR:
1213 #ifdef INET6
1214 		if (inp->inp_flags & INP_IPV6)
1215 			in6_setpeeraddr(inp, addr);
1216 		else
1217 #endif /* INET6 */
1218 			in_setpeeraddr(inp, addr);
1219 		break;
1220 
1221 	case PRU_SENSE:
1222 		/*
1223 		 * stat: don't bother with a blocksize.
1224 		 */
1225 		/*
1226 		 * Perhaps Path MTU might be returned for a connected
1227 		 * UDP socket in this case.
1228 		 */
1229 		return (0);
1230 
1231 	case PRU_SENDOOB:
1232 	case PRU_FASTTIMO:
1233 	case PRU_SLOWTIMO:
1234 	case PRU_PROTORCV:
1235 	case PRU_PROTOSEND:
1236 		error =  EOPNOTSUPP;
1237 		break;
1238 
1239 	case PRU_RCVD:
1240 	case PRU_RCVOOB:
1241 		return (EOPNOTSUPP);	/* do not free mbuf's */
1242 
1243 	default:
1244 		panic("udp_usrreq");
1245 	}
1246 
1247 release:
1248 	m_freem(control);
1249 	m_freem(m);
1250 	return (error);
1251 }
1252 
1253 int
1254 udp_attach(struct socket *so, int proto)
1255 {
1256 	int error;
1257 
1258 	if (so->so_pcb != NULL)
1259 		return EINVAL;
1260 
1261 	if ((error = soreserve(so, udp_sendspace, udp_recvspace)) ||
1262 	    (error = in_pcballoc(so, &udbtable)))
1263 		return error;
1264 #ifdef INET6
1265 	if (sotoinpcb(so)->inp_flags & INP_IPV6)
1266 		sotoinpcb(so)->inp_ipv6.ip6_hlim = ip6_defhlim;
1267 	else
1268 #endif /* INET6 */
1269 		sotoinpcb(so)->inp_ip.ip_ttl = ip_defttl;
1270 	return 0;
1271 }
1272 
1273 /*
1274  * Sysctl for udp variables.
1275  */
1276 int
1277 udp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
1278     size_t newlen)
1279 {
1280 	int error;
1281 
1282 	/* All sysctl names at this level are terminal. */
1283 	if (namelen != 1)
1284 		return (ENOTDIR);
1285 
1286 	switch (name[0]) {
1287 	case UDPCTL_BADDYNAMIC:
1288 		NET_LOCK();
1289 		error = sysctl_struct(oldp, oldlenp, newp, newlen,
1290 		    baddynamicports.udp, sizeof(baddynamicports.udp));
1291 		NET_UNLOCK();
1292 		return (error);
1293 
1294 	case UDPCTL_ROOTONLY:
1295 		if (newp && securelevel > 0)
1296 			return (EPERM);
1297 		NET_LOCK();
1298 		error = sysctl_struct(oldp, oldlenp, newp, newlen,
1299 		    rootonlyports.udp, sizeof(rootonlyports.udp));
1300 		NET_UNLOCK();
1301 		return (error);
1302 
1303 	case UDPCTL_STATS:
1304 		if (newp != NULL)
1305 			return (EPERM);
1306 
1307 		return (udp_sysctl_udpstat(oldp, oldlenp, newp));
1308 
1309 	default:
1310 		if (name[0] < UDPCTL_MAXID) {
1311 			NET_LOCK();
1312 			error = sysctl_int_arr(udpctl_vars, name, namelen,
1313 			    oldp, oldlenp, newp, newlen);
1314 			NET_UNLOCK();
1315 			return (error);
1316 		}
1317 		return (ENOPROTOOPT);
1318 	}
1319 	/* NOTREACHED */
1320 }
1321 
1322 int
1323 udp_sysctl_udpstat(void *oldp, size_t *oldlenp, void *newp)
1324 {
1325 	uint64_t counters[udps_ncounters];
1326 	struct udpstat udpstat;
1327 	u_long *words = (u_long *)&udpstat;
1328 	int i;
1329 
1330 	CTASSERT(sizeof(udpstat) == (nitems(counters) * sizeof(u_long)));
1331 	memset(&udpstat, 0, sizeof udpstat);
1332 	counters_read(udpcounters, counters, nitems(counters));
1333 
1334 	for (i = 0; i < nitems(counters); i++)
1335 		words[i] = (u_long)counters[i];
1336 
1337 	return (sysctl_rdstruct(oldp, oldlenp, newp,
1338 	    &udpstat, sizeof(udpstat)));
1339 }
1340