xref: /openbsd-src/sys/netinet/udp_usrreq.c (revision 5a38ef86d0b61900239c7913d24a05e7b88a58f0)
1 /*	$OpenBSD: udp_usrreq.c,v 1.267 2021/12/02 12:39:15 bluhm 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 const struct sysctl_bounded_args udpctl_vars[] = {
131 	{ UDPCTL_CHECKSUM, &udpcksum, 0, 1 },
132 	{ UDPCTL_RECVSPACE, &udp_recvspace, 0, INT_MAX },
133 	{ UDPCTL_SENDSPACE, &udp_sendspace, 0, INT_MAX },
134 };
135 
136 struct	inpcbtable udbtable;
137 struct	cpumem *udpcounters;
138 
139 void	udp_sbappend(struct inpcb *, struct mbuf *, struct ip *,
140 	    struct ip6_hdr *, int, struct udphdr *, struct sockaddr *,
141 	    u_int32_t);
142 int	udp_output(struct inpcb *, struct mbuf *, struct mbuf *, struct mbuf *);
143 void	udp_notify(struct inpcb *, int);
144 int	udp_sysctl_udpstat(void *, size_t *, void *);
145 
146 #ifndef	UDB_INITIAL_HASH_SIZE
147 #define	UDB_INITIAL_HASH_SIZE	128
148 #endif
149 
150 void
151 udp_init(void)
152 {
153 	udpcounters = counters_alloc(udps_ncounters);
154 	in_pcbinit(&udbtable, UDB_INITIAL_HASH_SIZE);
155 }
156 
157 int
158 udp_input(struct mbuf **mp, int *offp, int proto, int af)
159 {
160 	struct mbuf *m = *mp;
161 	int iphlen = *offp;
162 	struct ip *ip = NULL;
163 	struct udphdr *uh;
164 	struct inpcb *inp = NULL;
165 	struct ip save_ip;
166 	int len;
167 	u_int16_t savesum;
168 	union {
169 		struct sockaddr sa;
170 		struct sockaddr_in sin;
171 #ifdef INET6
172 		struct sockaddr_in6 sin6;
173 #endif /* INET6 */
174 	} srcsa, dstsa;
175 	struct ip6_hdr *ip6 = NULL;
176 	u_int32_t ipsecflowinfo = 0;
177 
178 	udpstat_inc(udps_ipackets);
179 
180 	IP6_EXTHDR_GET(uh, struct udphdr *, m, iphlen, sizeof(struct udphdr));
181 	if (!uh) {
182 		udpstat_inc(udps_hdrops);
183 		return IPPROTO_DONE;
184 	}
185 
186 	/* Check for illegal destination port 0 */
187 	if (uh->uh_dport == 0) {
188 		udpstat_inc(udps_noport);
189 		goto bad;
190 	}
191 
192 	/*
193 	 * Make mbuf data length reflect UDP length.
194 	 * If not enough data to reflect UDP length, drop.
195 	 */
196 	len = ntohs((u_int16_t)uh->uh_ulen);
197 	switch (af) {
198 	case AF_INET:
199 		if (m->m_pkthdr.len - iphlen != len) {
200 			if (len > (m->m_pkthdr.len - iphlen) ||
201 			    len < sizeof(struct udphdr)) {
202 				udpstat_inc(udps_badlen);
203 				goto bad;
204 			}
205 			m_adj(m, len - (m->m_pkthdr.len - iphlen));
206 		}
207 		ip = mtod(m, struct ip *);
208 		/*
209 		 * Save a copy of the IP header in case we want restore it
210 		 * for sending an ICMP error message in response.
211 		 */
212 		save_ip = *ip;
213 		break;
214 #ifdef INET6
215 	case AF_INET6:
216 		/* jumbograms */
217 		if (len == 0 && m->m_pkthdr.len - iphlen > 0xffff)
218 			len = m->m_pkthdr.len - iphlen;
219 		if (len != m->m_pkthdr.len - iphlen) {
220 			udpstat_inc(udps_badlen);
221 			goto bad;
222 		}
223 		ip6 = mtod(m, struct ip6_hdr *);
224 		break;
225 #endif /* INET6 */
226 	default:
227 		unhandled_af(af);
228 	}
229 
230 	/*
231 	 * Checksum extended UDP header and data.
232 	 * from W.R.Stevens: check incoming udp cksums even if
233 	 *	udpcksum is not set.
234 	 */
235 	savesum = uh->uh_sum;
236 	if (uh->uh_sum == 0) {
237 		udpstat_inc(udps_nosum);
238 #ifdef INET6
239 		/*
240 		 * In IPv6, the UDP checksum is ALWAYS used.
241 		 */
242 		if (ip6)
243 			goto bad;
244 #endif /* INET6 */
245 	} else {
246 		if ((m->m_pkthdr.csum_flags & M_UDP_CSUM_IN_OK) == 0) {
247 			if (m->m_pkthdr.csum_flags & M_UDP_CSUM_IN_BAD) {
248 				udpstat_inc(udps_badsum);
249 				goto bad;
250 			}
251 			udpstat_inc(udps_inswcsum);
252 
253 			if (ip)
254 				uh->uh_sum = in4_cksum(m, IPPROTO_UDP,
255 				    iphlen, len);
256 #ifdef INET6
257 			else if (ip6)
258 				uh->uh_sum = in6_cksum(m, IPPROTO_UDP,
259 				    iphlen, len);
260 #endif /* INET6 */
261 			if (uh->uh_sum != 0) {
262 				udpstat_inc(udps_badsum);
263 				goto bad;
264 			}
265 		}
266 	}
267 
268 #ifdef IPSEC
269 	if (udpencap_enable && udpencap_port && esp_enable &&
270 #if NPF > 0
271 	    !(m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) &&
272 #endif
273 	    uh->uh_dport == htons(udpencap_port)) {
274 		u_int32_t spi;
275 		int skip = iphlen + sizeof(struct udphdr);
276 
277 		if (m->m_pkthdr.len - skip < sizeof(u_int32_t)) {
278 			/* packet too short */
279 			m_freem(m);
280 			return IPPROTO_DONE;
281 		}
282 		m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
283 		/*
284 		 * decapsulate if the SPI is not zero, otherwise pass
285 		 * to userland
286 		 */
287 		if (spi != 0) {
288 			int protoff;
289 
290 			if ((m = *mp = m_pullup(m, skip)) == NULL) {
291 				udpstat_inc(udps_hdrops);
292 				return IPPROTO_DONE;
293 			}
294 
295 			/* remove the UDP header */
296 			bcopy(mtod(m, u_char *),
297 			    mtod(m, u_char *) + sizeof(struct udphdr), iphlen);
298 			m_adj(m, sizeof(struct udphdr));
299 			skip -= sizeof(struct udphdr);
300 
301 			espstat_inc(esps_udpencin);
302 			protoff = af == AF_INET ? offsetof(struct ip, ip_p) :
303 			    offsetof(struct ip6_hdr, ip6_nxt);
304 			return ipsec_common_input(mp, skip, protoff,
305 			    af, IPPROTO_ESP, 1);
306 		}
307 	}
308 #endif /* IPSEC */
309 
310 	switch (af) {
311 	case AF_INET:
312 		bzero(&srcsa, sizeof(struct sockaddr_in));
313 		srcsa.sin.sin_len = sizeof(struct sockaddr_in);
314 		srcsa.sin.sin_family = AF_INET;
315 		srcsa.sin.sin_port = uh->uh_sport;
316 		srcsa.sin.sin_addr = ip->ip_src;
317 
318 		bzero(&dstsa, sizeof(struct sockaddr_in));
319 		dstsa.sin.sin_len = sizeof(struct sockaddr_in);
320 		dstsa.sin.sin_family = AF_INET;
321 		dstsa.sin.sin_port = uh->uh_dport;
322 		dstsa.sin.sin_addr = ip->ip_dst;
323 		break;
324 #ifdef INET6
325 	case AF_INET6:
326 		bzero(&srcsa, sizeof(struct sockaddr_in6));
327 		srcsa.sin6.sin6_len = sizeof(struct sockaddr_in6);
328 		srcsa.sin6.sin6_family = AF_INET6;
329 		srcsa.sin6.sin6_port = uh->uh_sport;
330 #if 0 /*XXX inbound flowinfo */
331 		srcsa.sin6.sin6_flowinfo = htonl(0x0fffffff) & ip6->ip6_flow;
332 #endif
333 		/* KAME hack: recover scopeid */
334 		in6_recoverscope(&srcsa.sin6, &ip6->ip6_src);
335 
336 		bzero(&dstsa, sizeof(struct sockaddr_in6));
337 		dstsa.sin6.sin6_len = sizeof(struct sockaddr_in6);
338 		dstsa.sin6.sin6_family = AF_INET6;
339 		dstsa.sin6.sin6_port = uh->uh_dport;
340 #if 0 /*XXX inbound flowinfo */
341 		dstsa.sin6.sin6_flowinfo = htonl(0x0fffffff) & ip6->ip6_flow;
342 #endif
343 		/* KAME hack: recover scopeid */
344 		in6_recoverscope(&dstsa.sin6, &ip6->ip6_dst);
345 		break;
346 #endif /* INET6 */
347 	}
348 
349 #if NVXLAN > 0
350 	if (vxlan_enable > 0 &&
351 #if NPF > 0
352 	    !(m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) &&
353 #endif
354 	    vxlan_lookup(m, uh, iphlen, &srcsa.sa, &dstsa.sa) != 0)
355 		return IPPROTO_DONE;
356 #endif
357 
358 	if (m->m_flags & (M_BCAST|M_MCAST)) {
359 		struct inpcb *last;
360 		/*
361 		 * Deliver a multicast or broadcast datagram to *all* sockets
362 		 * for which the local and remote addresses and ports match
363 		 * those of the incoming datagram.  This allows more than
364 		 * one process to receive multi/broadcasts on the same port.
365 		 * (This really ought to be done for unicast datagrams as
366 		 * well, but that would cause problems with existing
367 		 * applications that open both address-specific sockets and
368 		 * a wildcard socket listening to the same port -- they would
369 		 * end up receiving duplicates of every unicast datagram.
370 		 * Those applications open the multiple sockets to overcome an
371 		 * inadequacy of the UDP socket interface, but for backwards
372 		 * compatibility we avoid the problem here rather than
373 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
374 		 */
375 
376 		/*
377 		 * Locate pcb(s) for datagram.
378 		 * (Algorithm copied from raw_intr().)
379 		 */
380 		last = NULL;
381 		NET_ASSERT_LOCKED();
382 		TAILQ_FOREACH(inp, &udbtable.inpt_queue, inp_queue) {
383 			if (inp->inp_socket->so_state & SS_CANTRCVMORE)
384 				continue;
385 #ifdef INET6
386 			/* don't accept it if AF does not match */
387 			if (ip6 && !(inp->inp_flags & INP_IPV6))
388 				continue;
389 			if (!ip6 && (inp->inp_flags & INP_IPV6))
390 				continue;
391 #endif
392 			if (rtable_l2(inp->inp_rtableid) !=
393 			    rtable_l2(m->m_pkthdr.ph_rtableid))
394 				continue;
395 			if (inp->inp_lport != uh->uh_dport)
396 				continue;
397 #ifdef INET6
398 			if (ip6) {
399 				if (inp->inp_ip6_minhlim &&
400 				    inp->inp_ip6_minhlim > ip6->ip6_hlim)
401 					continue;
402 				if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6))
403 					if (!IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6,
404 					    &ip6->ip6_dst))
405 						continue;
406 			} else
407 #endif /* INET6 */
408 			{
409 				if (inp->inp_ip_minttl &&
410 				    inp->inp_ip_minttl > ip->ip_ttl)
411 					continue;
412 
413 				if (inp->inp_laddr.s_addr != INADDR_ANY) {
414 					if (inp->inp_laddr.s_addr !=
415 					    ip->ip_dst.s_addr)
416 						continue;
417 				}
418 			}
419 #ifdef INET6
420 			if (ip6) {
421 				if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
422 					if (!IN6_ARE_ADDR_EQUAL(&inp->inp_faddr6,
423 					    &ip6->ip6_src) ||
424 					    inp->inp_fport != uh->uh_sport)
425 						continue;
426 			} else
427 #endif /* INET6 */
428 			if (inp->inp_faddr.s_addr != INADDR_ANY) {
429 				if (inp->inp_faddr.s_addr !=
430 				    ip->ip_src.s_addr ||
431 				    inp->inp_fport != uh->uh_sport)
432 					continue;
433 			}
434 
435 			if (last != NULL) {
436 				struct mbuf *n;
437 
438 				n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
439 				if (n != NULL) {
440 					udp_sbappend(last, n, ip, ip6, iphlen,
441 					    uh, &srcsa.sa, 0);
442 				}
443 			}
444 			last = inp;
445 			/*
446 			 * Don't look for additional matches if this one does
447 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
448 			 * socket options set.  This heuristic avoids searching
449 			 * through all pcbs in the common case of a non-shared
450 			 * port.  It assumes that an application will never
451 			 * clear these options after setting them.
452 			 */
453 			if ((last->inp_socket->so_options & (SO_REUSEPORT |
454 			    SO_REUSEADDR)) == 0)
455 				break;
456 		}
457 
458 		if (last == NULL) {
459 			/*
460 			 * No matching pcb found; discard datagram.
461 			 * (No need to send an ICMP Port Unreachable
462 			 * for a broadcast or multicast datgram.)
463 			 */
464 			udpstat_inc(udps_noportbcast);
465 			goto bad;
466 		}
467 
468 		udp_sbappend(last, m, ip, ip6, iphlen, uh, &srcsa.sa, 0);
469 		return IPPROTO_DONE;
470 	}
471 	/*
472 	 * Locate pcb for datagram.
473 	 */
474 #if NPF > 0
475 	inp = pf_inp_lookup(m);
476 #endif
477 	if (inp == NULL) {
478 #ifdef INET6
479 		if (ip6)
480 			inp = in6_pcbhashlookup(&udbtable, &ip6->ip6_src,
481 			    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
482 			    m->m_pkthdr.ph_rtableid);
483 		else
484 #endif /* INET6 */
485 		inp = in_pcbhashlookup(&udbtable, ip->ip_src, uh->uh_sport,
486 		    ip->ip_dst, uh->uh_dport, m->m_pkthdr.ph_rtableid);
487 	}
488 	if (inp == NULL) {
489 		udpstat_inc(udps_pcbhashmiss);
490 #ifdef INET6
491 		if (ip6) {
492 			inp = in6_pcblookup_listen(&udbtable, &ip6->ip6_dst,
493 			    uh->uh_dport, m, m->m_pkthdr.ph_rtableid);
494 		} else
495 #endif /* INET6 */
496 		inp = in_pcblookup_listen(&udbtable, ip->ip_dst,
497 		    uh->uh_dport, m, m->m_pkthdr.ph_rtableid);
498 	}
499 
500 #ifdef IPSEC
501 	if (ipsec_in_use) {
502 		struct m_tag *mtag;
503 		struct tdb_ident *tdbi;
504 		struct tdb *tdb;
505 		int error;
506 
507 		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
508 		if (mtag != NULL) {
509 			tdbi = (struct tdb_ident *)(mtag + 1);
510 			tdb = gettdb(tdbi->rdomain, tdbi->spi,
511 			    &tdbi->dst, tdbi->proto);
512 		} else
513 			tdb = NULL;
514 		error = ipsp_spd_lookup(m, af, iphlen, IPSP_DIRECTION_IN,
515 		    tdb, inp, NULL, 0);
516 		if (error) {
517 			udpstat_inc(udps_nosec);
518 			tdb_unref(tdb);
519 			goto bad;
520 		}
521 		/* create ipsec options while we know that tdb cannot be modified */
522 		if (tdb && tdb->tdb_ids)
523 			ipsecflowinfo = tdb->tdb_ids->id_flow;
524 		tdb_unref(tdb);
525 	}
526 #endif /*IPSEC */
527 
528 	if (inp == NULL) {
529 		udpstat_inc(udps_noport);
530 		if (m->m_flags & (M_BCAST | M_MCAST)) {
531 			udpstat_inc(udps_noportbcast);
532 			goto bad;
533 		}
534 #ifdef INET6
535 		if (ip6) {
536 			uh->uh_sum = savesum;
537 			icmp6_error(m, ICMP6_DST_UNREACH,
538 			    ICMP6_DST_UNREACH_NOPORT,0);
539 		} else
540 #endif /* INET6 */
541 		{
542 			*ip = save_ip;
543 			uh->uh_sum = savesum;
544 			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT,
545 			    0, 0);
546 		}
547 		return IPPROTO_DONE;
548 	}
549 
550 	KASSERT(sotoinpcb(inp->inp_socket) == inp);
551 	soassertlocked(inp->inp_socket);
552 
553 #ifdef INET6
554 	if (ip6 && inp->inp_ip6_minhlim &&
555 	    inp->inp_ip6_minhlim > ip6->ip6_hlim) {
556 		goto bad;
557 	} else
558 #endif
559 	if (ip && inp->inp_ip_minttl &&
560 	    inp->inp_ip_minttl > ip->ip_ttl) {
561 		goto bad;
562 	}
563 
564 #if NPF > 0
565 	if (inp->inp_socket->so_state & SS_ISCONNECTED)
566 		pf_inp_link(m, inp);
567 #endif
568 
569 #ifdef PIPEX
570 	if (pipex_enable && inp->inp_pipex) {
571 		struct pipex_session *session;
572 		int off = iphlen + sizeof(struct udphdr);
573 		if ((session = pipex_l2tp_lookup_session(m, off)) != NULL) {
574 			if ((m = *mp = pipex_l2tp_input(m, off, session,
575 			    ipsecflowinfo)) == NULL) {
576 				/* the packet is handled by PIPEX */
577 				return IPPROTO_DONE;
578 			}
579 		}
580 	}
581 #endif
582 
583 	udp_sbappend(inp, m, ip, ip6, iphlen, uh, &srcsa.sa, ipsecflowinfo);
584 	return IPPROTO_DONE;
585 bad:
586 	m_freem(m);
587 	return IPPROTO_DONE;
588 }
589 
590 void
591 udp_sbappend(struct inpcb *inp, struct mbuf *m, struct ip *ip,
592     struct ip6_hdr *ip6, int hlen, struct udphdr *uh,
593     struct sockaddr *srcaddr, u_int32_t ipsecflowinfo)
594 {
595 	struct socket *so = inp->inp_socket;
596 	struct mbuf *opts = NULL;
597 
598 	hlen += sizeof(*uh);
599 
600 	if (inp->inp_upcall != NULL) {
601 		m = (*inp->inp_upcall)(inp->inp_upcall_arg, m,
602 		    ip, ip6, uh, hlen);
603 		if (m == NULL)
604 			return;
605 	}
606 
607 #ifdef INET6
608 	if (ip6 && (inp->inp_flags & IN6P_CONTROLOPTS ||
609 	    so->so_options & SO_TIMESTAMP))
610 		ip6_savecontrol(inp, m, &opts);
611 #endif /* INET6 */
612 	if (ip && (inp->inp_flags & INP_CONTROLOPTS ||
613 	    so->so_options & SO_TIMESTAMP))
614 		ip_savecontrol(inp, &opts, ip, m);
615 #ifdef INET6
616 	if (ip6 && (inp->inp_flags & IN6P_RECVDSTPORT)) {
617 		struct mbuf **mp = &opts;
618 
619 		while (*mp)
620 			mp = &(*mp)->m_next;
621 		*mp = sbcreatecontrol((caddr_t)&uh->uh_dport, sizeof(u_int16_t),
622 		    IPV6_RECVDSTPORT, IPPROTO_IPV6);
623 	}
624 #endif /* INET6 */
625 	if (ip && (inp->inp_flags & INP_RECVDSTPORT)) {
626 		struct mbuf **mp = &opts;
627 
628 		while (*mp)
629 			mp = &(*mp)->m_next;
630 		*mp = sbcreatecontrol((caddr_t)&uh->uh_dport, sizeof(u_int16_t),
631 		    IP_RECVDSTPORT, IPPROTO_IP);
632 	}
633 #ifdef IPSEC
634 	if (ipsecflowinfo && (inp->inp_flags & INP_IPSECFLOWINFO)) {
635 		struct mbuf **mp = &opts;
636 
637 		while (*mp)
638 			mp = &(*mp)->m_next;
639 		*mp = sbcreatecontrol((caddr_t)&ipsecflowinfo,
640 		    sizeof(u_int32_t), IP_IPSECFLOWINFO, IPPROTO_IP);
641 	}
642 #endif
643 	m_adj(m, hlen);
644 	if (sbappendaddr(so, &so->so_rcv, srcaddr, m, opts) == 0) {
645 		udpstat_inc(udps_fullsock);
646 		m_freem(m);
647 		m_freem(opts);
648 		return;
649 	}
650 	sorwakeup(so);
651 }
652 
653 /*
654  * Notify a udp user of an asynchronous error;
655  * just wake up so that he can collect error status.
656  */
657 void
658 udp_notify(struct inpcb *inp, int errno)
659 {
660 	inp->inp_socket->so_error = errno;
661 	sorwakeup(inp->inp_socket);
662 	sowwakeup(inp->inp_socket);
663 }
664 
665 #ifdef INET6
666 void
667 udp6_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *d)
668 {
669 	struct udphdr uh;
670 	struct sockaddr_in6 sa6;
671 	struct ip6_hdr *ip6;
672 	struct mbuf *m;
673 	int off;
674 	void *cmdarg;
675 	struct ip6ctlparam *ip6cp = NULL;
676 	struct udp_portonly {
677 		u_int16_t uh_sport;
678 		u_int16_t uh_dport;
679 	} *uhp;
680 	void (*notify)(struct inpcb *, int) = udp_notify;
681 
682 	if (sa == NULL)
683 		return;
684 	if (sa->sa_family != AF_INET6 ||
685 	    sa->sa_len != sizeof(struct sockaddr_in6))
686 		return;
687 
688 	if ((unsigned)cmd >= PRC_NCMDS)
689 		return;
690 	if (PRC_IS_REDIRECT(cmd))
691 		notify = in_rtchange, d = NULL;
692 	else if (cmd == PRC_HOSTDEAD)
693 		d = NULL;
694 	else if (cmd == PRC_MSGSIZE)
695 		; /* special code is present, see below */
696 	else if (inet6ctlerrmap[cmd] == 0)
697 		return;
698 
699 	/* if the parameter is from icmp6, decode it. */
700 	if (d != NULL) {
701 		ip6cp = (struct ip6ctlparam *)d;
702 		m = ip6cp->ip6c_m;
703 		ip6 = ip6cp->ip6c_ip6;
704 		off = ip6cp->ip6c_off;
705 		cmdarg = ip6cp->ip6c_cmdarg;
706 	} else {
707 		m = NULL;
708 		ip6 = NULL;
709 		cmdarg = NULL;
710 		/* XXX: translate addresses into internal form */
711 		sa6 = *satosin6(sa);
712 		if (in6_embedscope(&sa6.sin6_addr, &sa6, NULL)) {
713 			/* should be impossible */
714 			return;
715 		}
716 	}
717 
718 	if (ip6cp && ip6cp->ip6c_finaldst) {
719 		bzero(&sa6, sizeof(sa6));
720 		sa6.sin6_family = AF_INET6;
721 		sa6.sin6_len = sizeof(sa6);
722 		sa6.sin6_addr = *ip6cp->ip6c_finaldst;
723 		/* XXX: assuming M is valid in this case */
724 		sa6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
725 		    ip6cp->ip6c_finaldst);
726 		if (in6_embedscope(ip6cp->ip6c_finaldst, &sa6, NULL)) {
727 			/* should be impossible */
728 			return;
729 		}
730 	} else {
731 		/* XXX: translate addresses into internal form */
732 		sa6 = *satosin6(sa);
733 		if (in6_embedscope(&sa6.sin6_addr, &sa6, NULL)) {
734 			/* should be impossible */
735 			return;
736 		}
737 	}
738 
739 	if (ip6) {
740 		/*
741 		 * XXX: We assume that when IPV6 is non NULL,
742 		 * M and OFF are valid.
743 		 */
744 		struct sockaddr_in6 sa6_src;
745 
746 		/* check if we can safely examine src and dst ports */
747 		if (m->m_pkthdr.len < off + sizeof(*uhp))
748 			return;
749 
750 		bzero(&uh, sizeof(uh));
751 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
752 
753 		bzero(&sa6_src, sizeof(sa6_src));
754 		sa6_src.sin6_family = AF_INET6;
755 		sa6_src.sin6_len = sizeof(sa6_src);
756 		sa6_src.sin6_addr = ip6->ip6_src;
757 		sa6_src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
758 		    &ip6->ip6_src);
759 		if (in6_embedscope(&sa6_src.sin6_addr, &sa6_src, NULL)) {
760 			/* should be impossible */
761 			return;
762 		}
763 
764 		if (cmd == PRC_MSGSIZE) {
765 			int valid = 0;
766 
767 			/*
768 			 * Check to see if we have a valid UDP socket
769 			 * corresponding to the address in the ICMPv6 message
770 			 * payload.
771 			 */
772 			if (in6_pcbhashlookup(&udbtable, &sa6.sin6_addr,
773 			    uh.uh_dport, &sa6_src.sin6_addr, uh.uh_sport,
774 			    rdomain))
775 				valid = 1;
776 #if 0
777 			/*
778 			 * As the use of sendto(2) is fairly popular,
779 			 * we may want to allow non-connected pcb too.
780 			 * But it could be too weak against attacks...
781 			 * We should at least check if the local address (= s)
782 			 * is really ours.
783 			 */
784 			else if (in6_pcblookup_listen(&udbtable,
785 			    &sa6_src.sin6_addr, uh.uh_sport, NULL,
786 			    rdomain))
787 				valid = 1;
788 #endif
789 
790 			/*
791 			 * Depending on the value of "valid" and routing table
792 			 * size (mtudisc_{hi,lo}wat), we will:
793 			 * - recalculate the new MTU and create the
794 			 *   corresponding routing entry, or
795 			 * - ignore the MTU change notification.
796 			 */
797 			icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
798 
799 			/*
800 			 * regardless of if we called icmp6_mtudisc_update(),
801 			 * we need to call in6_pcbnotify(), to notify path
802 			 * MTU change to the userland (2292bis-02), because
803 			 * some unconnected sockets may share the same
804 			 * destination and want to know the path MTU.
805 			 */
806 		}
807 
808 		(void) in6_pcbnotify(&udbtable, &sa6, uh.uh_dport,
809 		    &sa6_src, uh.uh_sport, rdomain, cmd, cmdarg, notify);
810 	} else {
811 		(void) in6_pcbnotify(&udbtable, &sa6, 0,
812 		    &sa6_any, 0, rdomain, cmd, cmdarg, notify);
813 	}
814 }
815 #endif
816 
817 void
818 udp_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v)
819 {
820 	struct ip *ip = v;
821 	struct udphdr *uhp;
822 	struct in_addr faddr;
823 	struct inpcb *inp;
824 	void (*notify)(struct inpcb *, int) = udp_notify;
825 	int errno;
826 
827 	if (sa == NULL)
828 		return;
829 	if (sa->sa_family != AF_INET ||
830 	    sa->sa_len != sizeof(struct sockaddr_in))
831 		return;
832 	faddr = satosin(sa)->sin_addr;
833 	if (faddr.s_addr == INADDR_ANY)
834 		return;
835 
836 	if ((unsigned)cmd >= PRC_NCMDS)
837 		return;
838 	errno = inetctlerrmap[cmd];
839 	if (PRC_IS_REDIRECT(cmd))
840 		notify = in_rtchange, ip = 0;
841 	else if (cmd == PRC_HOSTDEAD)
842 		ip = 0;
843 	else if (errno == 0)
844 		return;
845 	if (ip) {
846 		uhp = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
847 
848 #ifdef IPSEC
849 		/* PMTU discovery for udpencap */
850 		if (cmd == PRC_MSGSIZE && ip_mtudisc && udpencap_enable &&
851 		    udpencap_port && uhp->uh_sport == htons(udpencap_port)) {
852 			udpencap_ctlinput(cmd, sa, rdomain, v);
853 			return;
854 		}
855 #endif
856 		inp = in_pcbhashlookup(&udbtable,
857 		    ip->ip_dst, uhp->uh_dport, ip->ip_src, uhp->uh_sport,
858 		    rdomain);
859 		if (inp && inp->inp_socket != NULL)
860 			notify(inp, errno);
861 	} else
862 		in_pcbnotifyall(&udbtable, sa, rdomain, errno, notify);
863 }
864 
865 int
866 udp_output(struct inpcb *inp, struct mbuf *m, struct mbuf *addr,
867     struct mbuf *control)
868 {
869 	struct sockaddr_in *sin = NULL;
870 	struct udpiphdr *ui;
871 	u_int32_t ipsecflowinfo = 0;
872 	struct sockaddr_in src_sin;
873 	int len = m->m_pkthdr.len;
874 	struct in_addr *laddr;
875 	int error = 0;
876 
877 #ifdef DIAGNOSTIC
878 	if ((inp->inp_flags & INP_IPV6) != 0)
879 		panic("IPv6 inpcb to %s", __func__);
880 #endif
881 
882 	/*
883 	 * Compute the packet length of the IP header, and
884 	 * punt if the length looks bogus.
885 	 */
886 	if ((len + sizeof(struct udpiphdr)) > IP_MAXPACKET) {
887 		error = EMSGSIZE;
888 		goto release;
889 	}
890 
891 	memset(&src_sin, 0, sizeof(src_sin));
892 
893 	if (control) {
894 		u_int clen;
895 		struct cmsghdr *cm;
896 		caddr_t cmsgs;
897 
898 		/*
899 		 * XXX: Currently, we assume all the optional information is
900 		 * stored in a single mbuf.
901 		 */
902 		if (control->m_next) {
903 			error = EINVAL;
904 			goto release;
905 		}
906 
907 		clen = control->m_len;
908 		cmsgs = mtod(control, caddr_t);
909 		do {
910 			if (clen < CMSG_LEN(0)) {
911 				error = EINVAL;
912 				goto release;
913 			}
914 			cm = (struct cmsghdr *)cmsgs;
915 			if (cm->cmsg_len < CMSG_LEN(0) ||
916 			    CMSG_ALIGN(cm->cmsg_len) > clen) {
917 				error = EINVAL;
918 				goto release;
919 			}
920 #ifdef IPSEC
921 			if ((inp->inp_flags & INP_IPSECFLOWINFO) != 0 &&
922 			    cm->cmsg_len == CMSG_LEN(sizeof(ipsecflowinfo)) &&
923 			    cm->cmsg_level == IPPROTO_IP &&
924 			    cm->cmsg_type == IP_IPSECFLOWINFO) {
925 				ipsecflowinfo = *(u_int32_t *)CMSG_DATA(cm);
926 			} else
927 #endif
928 			if (cm->cmsg_len == CMSG_LEN(sizeof(struct in_addr)) &&
929 			    cm->cmsg_level == IPPROTO_IP &&
930 			    cm->cmsg_type == IP_SENDSRCADDR) {
931 				memcpy(&src_sin.sin_addr, CMSG_DATA(cm),
932 				    sizeof(struct in_addr));
933 				src_sin.sin_family = AF_INET;
934 				src_sin.sin_len = sizeof(src_sin);
935 				/* no check on reuse when sin->sin_port == 0 */
936 				if ((error = in_pcbaddrisavail(inp, &src_sin,
937 				    0, curproc)))
938 					goto release;
939 			}
940 			clen -= CMSG_ALIGN(cm->cmsg_len);
941 			cmsgs += CMSG_ALIGN(cm->cmsg_len);
942 		} while (clen);
943 	}
944 
945 	if (addr) {
946 		if ((error = in_nam2sin(addr, &sin)))
947 			goto release;
948 		if (sin->sin_port == 0) {
949 			error = EADDRNOTAVAIL;
950 			goto release;
951 		}
952 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
953 			error = EISCONN;
954 			goto release;
955 		}
956 		error = in_pcbselsrc(&laddr, sin, inp);
957 		if (error)
958 			goto release;
959 
960 		if (inp->inp_lport == 0) {
961 			error = in_pcbbind(inp, NULL, curproc);
962 			if (error)
963 				goto release;
964 		}
965 
966 		if (src_sin.sin_len > 0 &&
967 		    src_sin.sin_addr.s_addr != INADDR_ANY &&
968 		    src_sin.sin_addr.s_addr != inp->inp_laddr.s_addr) {
969 			src_sin.sin_port = inp->inp_lport;
970 			if (inp->inp_laddr.s_addr != INADDR_ANY &&
971 			    (error =
972 			    in_pcbaddrisavail(inp, &src_sin, 0, curproc)))
973 				goto release;
974 			laddr = &src_sin.sin_addr;
975 		}
976 	} else {
977 		if (inp->inp_faddr.s_addr == INADDR_ANY) {
978 			error = ENOTCONN;
979 			goto release;
980 		}
981 		laddr = &inp->inp_laddr;
982 	}
983 
984 	/*
985 	 * Calculate data length and get a mbuf
986 	 * for UDP and IP headers.
987 	 */
988 	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
989 	if (m == NULL) {
990 		error = ENOBUFS;
991 		goto bail;
992 	}
993 
994 	/*
995 	 * Fill in mbuf with extended UDP header
996 	 * and addresses and length put into network format.
997 	 */
998 	ui = mtod(m, struct udpiphdr *);
999 	bzero(ui->ui_x1, sizeof ui->ui_x1);
1000 	ui->ui_pr = IPPROTO_UDP;
1001 	ui->ui_len = htons((u_int16_t)len + sizeof (struct udphdr));
1002 	ui->ui_src = *laddr;
1003 	ui->ui_dst = sin ? sin->sin_addr : inp->inp_faddr;
1004 	ui->ui_sport = inp->inp_lport;
1005 	ui->ui_dport = sin ? sin->sin_port : inp->inp_fport;
1006 	ui->ui_ulen = ui->ui_len;
1007 	((struct ip *)ui)->ip_len = htons(sizeof (struct udpiphdr) + len);
1008 	((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl;
1009 	((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos;
1010 	if (udpcksum)
1011 		m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT;
1012 
1013 	udpstat_inc(udps_opackets);
1014 
1015 	/* force routing table */
1016 	m->m_pkthdr.ph_rtableid = inp->inp_rtableid;
1017 
1018 #if NPF > 0
1019 	if (inp->inp_socket->so_state & SS_ISCONNECTED)
1020 		pf_mbuf_link_inpcb(m, inp);
1021 #endif
1022 
1023 	error = ip_output(m, inp->inp_options, &inp->inp_route,
1024 	    (inp->inp_socket->so_options & SO_BROADCAST), inp->inp_moptions,
1025 	    inp, ipsecflowinfo);
1026 
1027 bail:
1028 	m_freem(control);
1029 	return (error);
1030 
1031 release:
1032 	m_freem(m);
1033 	goto bail;
1034 }
1035 
1036 /*ARGSUSED*/
1037 int
1038 udp_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *addr,
1039     struct mbuf *control, struct proc *p)
1040 {
1041 	struct inpcb *inp;
1042 	int error = 0;
1043 
1044 	if (req == PRU_CONTROL) {
1045 #ifdef INET6
1046 		if (sotopf(so) == PF_INET6)
1047 			return (in6_control(so, (u_long)m, (caddr_t)addr,
1048 			    (struct ifnet *)control));
1049 		else
1050 #endif /* INET6 */
1051 			return (in_control(so, (u_long)m, (caddr_t)addr,
1052 			    (struct ifnet *)control));
1053 	}
1054 
1055 	soassertlocked(so);
1056 
1057 	inp = sotoinpcb(so);
1058 	if (inp == NULL) {
1059 		error = EINVAL;
1060 		goto release;
1061 	}
1062 
1063 	/*
1064 	 * Note: need to block udp_input while changing
1065 	 * the udp pcb queue and/or pcb addresses.
1066 	 */
1067 	switch (req) {
1068 
1069 	case PRU_BIND:
1070 		error = in_pcbbind(inp, addr, p);
1071 		break;
1072 
1073 	case PRU_LISTEN:
1074 		error = EOPNOTSUPP;
1075 		break;
1076 
1077 	case PRU_CONNECT:
1078 #ifdef INET6
1079 		if (inp->inp_flags & INP_IPV6) {
1080 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6)) {
1081 				error = EISCONN;
1082 				break;
1083 			}
1084 			error = in6_pcbconnect(inp, addr);
1085 		} else
1086 #endif /* INET6 */
1087 		{
1088 			if (inp->inp_faddr.s_addr != INADDR_ANY) {
1089 				error = EISCONN;
1090 				break;
1091 			}
1092 			error = in_pcbconnect(inp, addr);
1093 		}
1094 
1095 		if (error == 0)
1096 			soisconnected(so);
1097 		break;
1098 
1099 	case PRU_CONNECT2:
1100 		error = EOPNOTSUPP;
1101 		break;
1102 
1103 	case PRU_ACCEPT:
1104 		error = EOPNOTSUPP;
1105 		break;
1106 
1107 	case PRU_DISCONNECT:
1108 #ifdef INET6
1109 		if (inp->inp_flags & INP_IPV6) {
1110 			if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6)) {
1111 				error = ENOTCONN;
1112 				break;
1113 			}
1114 		} else
1115 #endif /* INET6 */
1116 		{
1117 			if (inp->inp_faddr.s_addr == INADDR_ANY) {
1118 				error = ENOTCONN;
1119 				break;
1120 			}
1121 		}
1122 
1123 #ifdef INET6
1124 		if (inp->inp_flags & INP_IPV6)
1125 			inp->inp_laddr6 = in6addr_any;
1126 		else
1127 #endif /* INET6 */
1128 			inp->inp_laddr.s_addr = INADDR_ANY;
1129 		in_pcbdisconnect(inp);
1130 
1131 		so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1132 		break;
1133 
1134 	case PRU_SHUTDOWN:
1135 		socantsendmore(so);
1136 		break;
1137 
1138 	case PRU_SEND:
1139 #ifdef PIPEX
1140 		if (inp->inp_pipex) {
1141 			struct pipex_session *session;
1142 
1143 			if (addr != NULL)
1144 				session =
1145 				    pipex_l2tp_userland_lookup_session(m,
1146 					mtod(addr, struct sockaddr *));
1147 			else
1148 #ifdef INET6
1149 			if (inp->inp_flags & INP_IPV6)
1150 				session =
1151 				    pipex_l2tp_userland_lookup_session_ipv6(
1152 					m, inp->inp_faddr6);
1153 			else
1154 #endif
1155 				session =
1156 				    pipex_l2tp_userland_lookup_session_ipv4(
1157 					m, inp->inp_faddr);
1158 			if (session != NULL)
1159 				if ((m = pipex_l2tp_userland_output(
1160 				    m, session)) == NULL) {
1161 					error = ENOMEM;
1162 					goto release;
1163 				}
1164 		}
1165 #endif
1166 
1167 #ifdef INET6
1168 		if (inp->inp_flags & INP_IPV6)
1169 			error = udp6_output(inp, m, addr, control);
1170 		else
1171 #endif
1172 			error = udp_output(inp, m, addr, control);
1173 		return (error);
1174 
1175 	case PRU_ABORT:
1176 		soisdisconnected(so);
1177 		in_pcbdetach(inp);
1178 		break;
1179 
1180 	case PRU_SOCKADDR:
1181 #ifdef INET6
1182 		if (inp->inp_flags & INP_IPV6)
1183 			in6_setsockaddr(inp, addr);
1184 		else
1185 #endif /* INET6 */
1186 			in_setsockaddr(inp, addr);
1187 		break;
1188 
1189 	case PRU_PEERADDR:
1190 #ifdef INET6
1191 		if (inp->inp_flags & INP_IPV6)
1192 			in6_setpeeraddr(inp, addr);
1193 		else
1194 #endif /* INET6 */
1195 			in_setpeeraddr(inp, addr);
1196 		break;
1197 
1198 	case PRU_SENSE:
1199 		/*
1200 		 * stat: don't bother with a blocksize.
1201 		 */
1202 		/*
1203 		 * Perhaps Path MTU might be returned for a connected
1204 		 * UDP socket in this case.
1205 		 */
1206 		break;
1207 
1208 	case PRU_SENDOOB:
1209 	case PRU_FASTTIMO:
1210 	case PRU_SLOWTIMO:
1211 	case PRU_PROTORCV:
1212 	case PRU_PROTOSEND:
1213 	case PRU_RCVD:
1214 	case PRU_RCVOOB:
1215 		error =  EOPNOTSUPP;
1216 		break;
1217 
1218 	default:
1219 		panic("udp_usrreq");
1220 	}
1221 release:
1222 	if (req != PRU_RCVD && req != PRU_RCVOOB && req != PRU_SENSE) {
1223 		m_freem(control);
1224 		m_freem(m);
1225 	}
1226 	return (error);
1227 }
1228 
1229 int
1230 udp_attach(struct socket *so, int proto)
1231 {
1232 	int error;
1233 
1234 	if (so->so_pcb != NULL)
1235 		return EINVAL;
1236 
1237 	if ((error = soreserve(so, udp_sendspace, udp_recvspace)))
1238 		return error;
1239 
1240 	NET_ASSERT_LOCKED();
1241 	if ((error = in_pcballoc(so, &udbtable)))
1242 		return error;
1243 #ifdef INET6
1244 	if (sotoinpcb(so)->inp_flags & INP_IPV6)
1245 		sotoinpcb(so)->inp_ipv6.ip6_hlim = ip6_defhlim;
1246 	else
1247 #endif /* INET6 */
1248 		sotoinpcb(so)->inp_ip.ip_ttl = ip_defttl;
1249 	return 0;
1250 }
1251 
1252 int
1253 udp_detach(struct socket *so)
1254 {
1255 	struct inpcb *inp;
1256 
1257 	soassertlocked(so);
1258 
1259 	inp = sotoinpcb(so);
1260 	if (inp == NULL)
1261 		return (EINVAL);
1262 
1263 	in_pcbdetach(inp);
1264 	return (0);
1265 }
1266 
1267 /*
1268  * Sysctl for udp variables.
1269  */
1270 int
1271 udp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
1272     size_t newlen)
1273 {
1274 	int error;
1275 
1276 	/* All sysctl names at this level are terminal. */
1277 	if (namelen != 1)
1278 		return (ENOTDIR);
1279 
1280 	switch (name[0]) {
1281 	case UDPCTL_BADDYNAMIC:
1282 		NET_LOCK();
1283 		error = sysctl_struct(oldp, oldlenp, newp, newlen,
1284 		    baddynamicports.udp, sizeof(baddynamicports.udp));
1285 		NET_UNLOCK();
1286 		return (error);
1287 
1288 	case UDPCTL_ROOTONLY:
1289 		if (newp && securelevel > 0)
1290 			return (EPERM);
1291 		NET_LOCK();
1292 		error = sysctl_struct(oldp, oldlenp, newp, newlen,
1293 		    rootonlyports.udp, sizeof(rootonlyports.udp));
1294 		NET_UNLOCK();
1295 		return (error);
1296 
1297 	case UDPCTL_STATS:
1298 		if (newp != NULL)
1299 			return (EPERM);
1300 
1301 		return (udp_sysctl_udpstat(oldp, oldlenp, newp));
1302 
1303 	default:
1304 		NET_LOCK();
1305 		error = sysctl_bounded_arr(udpctl_vars, nitems(udpctl_vars),
1306 		    name, namelen, oldp, oldlenp, newp, newlen);
1307 		NET_UNLOCK();
1308 		return (error);
1309 	}
1310 	/* NOTREACHED */
1311 }
1312 
1313 int
1314 udp_sysctl_udpstat(void *oldp, size_t *oldlenp, void *newp)
1315 {
1316 	uint64_t counters[udps_ncounters];
1317 	struct udpstat udpstat;
1318 	u_long *words = (u_long *)&udpstat;
1319 	int i;
1320 
1321 	CTASSERT(sizeof(udpstat) == (nitems(counters) * sizeof(u_long)));
1322 	memset(&udpstat, 0, sizeof udpstat);
1323 	counters_read(udpcounters, counters, nitems(counters));
1324 
1325 	for (i = 0; i < nitems(counters); i++)
1326 		words[i] = (u_long)counters[i];
1327 
1328 	return (sysctl_rdstruct(oldp, oldlenp, newp,
1329 	    &udpstat, sizeof(udpstat)));
1330 }
1331