xref: /freebsd/sys/netinet/udp_usrreq.c (revision a14a0223ae1b172e96dd2a1d849e22026a98b692)
1 /*
2  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)udp_usrreq.c	8.6 (Berkeley) 5/23/95
34  * $FreeBSD$
35  */
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/proc.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/socketvar.h>
46 #include <sys/sysctl.h>
47 #include <sys/syslog.h>
48 
49 #include <vm/vm_zone.h>
50 
51 #include <net/if.h>
52 #include <net/route.h>
53 
54 #include <netinet/in.h>
55 #include <netinet/in_systm.h>
56 #include <netinet/ip.h>
57 #include <netinet/in_pcb.h>
58 #include <netinet/in_var.h>
59 #include <netinet/ip_var.h>
60 #include <netinet/ip_icmp.h>
61 #include <netinet/icmp_var.h>
62 #include <netinet/udp.h>
63 #include <netinet/udp_var.h>
64 
65 /*
66  * UDP protocol implementation.
67  * Per RFC 768, August, 1980.
68  */
69 #ifndef	COMPAT_42
70 static int	udpcksum = 1;
71 #else
72 static int	udpcksum = 0;		/* XXX */
73 #endif
74 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
75 		&udpcksum, 0, "");
76 
77 int	log_in_vain = 0;
78 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
79     &log_in_vain, 0, "Log all incoming UDP packets");
80 
81 static int	blackhole = 0;
82 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
83 	&blackhole, 0, "Do not send port unreachables for refused connects");
84 
85 struct	inpcbhead udb;		/* from udp_var.h */
86 struct	inpcbinfo udbinfo;
87 
88 #ifndef UDBHASHSIZE
89 #define UDBHASHSIZE 16
90 #endif
91 
92 struct	udpstat udpstat;	/* from udp_var.h */
93 SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RD,
94     &udpstat, udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
95 
96 static struct	sockaddr_in udp_in = { sizeof(udp_in), AF_INET };
97 
98 static	int udp_output __P((struct inpcb *, struct mbuf *, struct sockaddr *,
99 			    struct mbuf *, struct proc *));
100 
101 void
102 udp_init()
103 {
104 	LIST_INIT(&udb);
105 	udbinfo.listhead = &udb;
106 	udbinfo.hashbase = hashinit(UDBHASHSIZE, M_PCB, &udbinfo.hashmask);
107 	udbinfo.porthashbase = hashinit(UDBHASHSIZE, M_PCB,
108 					&udbinfo.porthashmask);
109 	udbinfo.ipi_zone = zinit("udpcb", sizeof(struct inpcb), maxsockets,
110 				 ZONE_INTERRUPT, 0);
111 }
112 
113 void
114 udp_input(m, iphlen)
115 	register struct mbuf *m;
116 	int iphlen;
117 {
118 	register struct ip *ip;
119 	register struct udphdr *uh;
120 	register struct inpcb *inp;
121 	struct mbuf *opts = 0;
122 	int len;
123 	struct ip save_ip;
124 
125 	udpstat.udps_ipackets++;
126 
127 	/*
128 	 * Strip IP options, if any; should skip this,
129 	 * make available to user, and use on returned packets,
130 	 * but we don't yet have a way to check the checksum
131 	 * with options still present.
132 	 */
133 	if (iphlen > sizeof (struct ip)) {
134 		ip_stripoptions(m, (struct mbuf *)0);
135 		iphlen = sizeof(struct ip);
136 	}
137 
138 	/*
139 	 * Get IP and UDP header together in first mbuf.
140 	 */
141 	ip = mtod(m, struct ip *);
142 	if (m->m_len < iphlen + sizeof(struct udphdr)) {
143 		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
144 			udpstat.udps_hdrops++;
145 			return;
146 		}
147 		ip = mtod(m, struct ip *);
148 	}
149 	uh = (struct udphdr *)((caddr_t)ip + iphlen);
150 
151 	/*
152 	 * Make mbuf data length reflect UDP length.
153 	 * If not enough data to reflect UDP length, drop.
154 	 */
155 	len = ntohs((u_short)uh->uh_ulen);
156 	if (ip->ip_len != len) {
157 		if (len > ip->ip_len || len < sizeof(struct udphdr)) {
158 			udpstat.udps_badlen++;
159 			goto bad;
160 		}
161 		m_adj(m, len - ip->ip_len);
162 		/* ip->ip_len = len; */
163 	}
164 	/*
165 	 * Save a copy of the IP header in case we want restore it
166 	 * for sending an ICMP error message in response.
167 	 */
168 	save_ip = *ip;
169 
170 	/*
171 	 * Checksum extended UDP header and data.
172 	 */
173 	if (uh->uh_sum) {
174 		bzero(((struct ipovly *)ip)->ih_x1, 9);
175 		((struct ipovly *)ip)->ih_len = uh->uh_ulen;
176 		uh->uh_sum = in_cksum(m, len + sizeof (struct ip));
177 		if (uh->uh_sum) {
178 			udpstat.udps_badsum++;
179 			m_freem(m);
180 			return;
181 		}
182 	}
183 
184 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
185 	    in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
186 		struct inpcb *last;
187 		/*
188 		 * Deliver a multicast or broadcast datagram to *all* sockets
189 		 * for which the local and remote addresses and ports match
190 		 * those of the incoming datagram.  This allows more than
191 		 * one process to receive multi/broadcasts on the same port.
192 		 * (This really ought to be done for unicast datagrams as
193 		 * well, but that would cause problems with existing
194 		 * applications that open both address-specific sockets and
195 		 * a wildcard socket listening to the same port -- they would
196 		 * end up receiving duplicates of every unicast datagram.
197 		 * Those applications open the multiple sockets to overcome an
198 		 * inadequacy of the UDP socket interface, but for backwards
199 		 * compatibility we avoid the problem here rather than
200 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
201 		 */
202 
203 		/*
204 		 * Construct sockaddr format source address.
205 		 */
206 		udp_in.sin_port = uh->uh_sport;
207 		udp_in.sin_addr = ip->ip_src;
208 		m->m_len -= sizeof (struct udpiphdr);
209 		m->m_data += sizeof (struct udpiphdr);
210 		/*
211 		 * Locate pcb(s) for datagram.
212 		 * (Algorithm copied from raw_intr().)
213 		 */
214 		last = NULL;
215 		for (inp = udb.lh_first; inp != NULL; inp = inp->inp_list.le_next) {
216 			if (inp->inp_lport != uh->uh_dport)
217 				continue;
218 			if (inp->inp_laddr.s_addr != INADDR_ANY) {
219 				if (inp->inp_laddr.s_addr !=
220 				    ip->ip_dst.s_addr)
221 					continue;
222 			}
223 			if (inp->inp_faddr.s_addr != INADDR_ANY) {
224 				if (inp->inp_faddr.s_addr !=
225 				    ip->ip_src.s_addr ||
226 				    inp->inp_fport != uh->uh_sport)
227 					continue;
228 			}
229 
230 			if (last != NULL) {
231 				struct mbuf *n;
232 
233 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
234 					if (last->inp_flags & INP_CONTROLOPTS
235 					    || last->inp_socket->so_options & SO_TIMESTAMP)
236 						ip_savecontrol(last, &opts, ip, n);
237 					if (sbappendaddr(&last->inp_socket->so_rcv,
238 						(struct sockaddr *)&udp_in,
239 						n, opts) == 0) {
240 						m_freem(n);
241 						if (opts)
242 						    m_freem(opts);
243 						udpstat.udps_fullsock++;
244 					} else
245 						sorwakeup(last->inp_socket);
246 					opts = 0;
247 				}
248 			}
249 			last = inp;
250 			/*
251 			 * Don't look for additional matches if this one does
252 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
253 			 * socket options set.  This heuristic avoids searching
254 			 * through all pcbs in the common case of a non-shared
255 			 * port.  It * assumes that an application will never
256 			 * clear these options after setting them.
257 			 */
258 			if ((last->inp_socket->so_options&(SO_REUSEPORT|SO_REUSEADDR)) == 0)
259 				break;
260 		}
261 
262 		if (last == NULL) {
263 			/*
264 			 * No matching pcb found; discard datagram.
265 			 * (No need to send an ICMP Port Unreachable
266 			 * for a broadcast or multicast datgram.)
267 			 */
268 			udpstat.udps_noportbcast++;
269 			goto bad;
270 		}
271 		if (last->inp_flags & INP_CONTROLOPTS
272 		    || last->inp_socket->so_options & SO_TIMESTAMP)
273 			ip_savecontrol(last, &opts, ip, m);
274 		if (sbappendaddr(&last->inp_socket->so_rcv,
275 		     (struct sockaddr *)&udp_in,
276 		     m, opts) == 0) {
277 			udpstat.udps_fullsock++;
278 			goto bad;
279 		}
280 		sorwakeup(last->inp_socket);
281 		return;
282 	}
283 	/*
284 	 * Locate pcb for datagram.
285 	 */
286 	inp = in_pcblookup_hash(&udbinfo, ip->ip_src, uh->uh_sport,
287 	    ip->ip_dst, uh->uh_dport, 1);
288 	if (inp == NULL) {
289 		if (log_in_vain) {
290 			char buf[4*sizeof "123"];
291 
292 			strcpy(buf, inet_ntoa(ip->ip_dst));
293 			log(LOG_INFO,
294 			    "Connection attempt to UDP %s:%d from %s:%d\n",
295 			    buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
296 			    ntohs(uh->uh_sport));
297 		}
298 		udpstat.udps_noport++;
299 		if (m->m_flags & (M_BCAST | M_MCAST)) {
300 			udpstat.udps_noportbcast++;
301 			goto bad;
302 		}
303 		*ip = save_ip;
304 #ifdef ICMP_BANDLIM
305 		if (badport_bandlim(0) < 0)
306 			goto bad;
307 #endif
308 		if (!blackhole)
309 			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
310 		return;
311 	}
312 
313 	/*
314 	 * Construct sockaddr format source address.
315 	 * Stuff source address and datagram in user buffer.
316 	 */
317 	udp_in.sin_port = uh->uh_sport;
318 	udp_in.sin_addr = ip->ip_src;
319 	if (inp->inp_flags & INP_CONTROLOPTS
320 	    || inp->inp_socket->so_options & SO_TIMESTAMP)
321 		ip_savecontrol(inp, &opts, ip, m);
322 	iphlen += sizeof(struct udphdr);
323 	m->m_len -= iphlen;
324 	m->m_pkthdr.len -= iphlen;
325 	m->m_data += iphlen;
326 	if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in,
327 	    m, opts) == 0) {
328 		udpstat.udps_fullsock++;
329 		goto bad;
330 	}
331 	sorwakeup(inp->inp_socket);
332 	return;
333 bad:
334 	m_freem(m);
335 	if (opts)
336 		m_freem(opts);
337 }
338 
339 /*
340  * Notify a udp user of an asynchronous error;
341  * just wake up so that he can collect error status.
342  */
343 void
344 udp_notify(inp, errno)
345 	register struct inpcb *inp;
346 	int errno;
347 {
348 	inp->inp_socket->so_error = errno;
349 	sorwakeup(inp->inp_socket);
350 	sowwakeup(inp->inp_socket);
351 }
352 
353 void
354 udp_ctlinput(cmd, sa, vip)
355 	int cmd;
356 	struct sockaddr *sa;
357 	void *vip;
358 {
359 	register struct ip *ip = vip;
360 	register struct udphdr *uh;
361 
362 	if (!PRC_IS_REDIRECT(cmd) &&
363 	    ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0))
364 		return;
365 	if (ip) {
366 		uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
367 		in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport,
368 			cmd, udp_notify);
369 	} else
370 		in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify);
371 }
372 
373 static int
374 udp_pcblist SYSCTL_HANDLER_ARGS
375 {
376 	int error, i, n, s;
377 	struct inpcb *inp, **inp_list;
378 	inp_gen_t gencnt;
379 	struct xinpgen xig;
380 
381 	/*
382 	 * The process of preparing the TCB list is too time-consuming and
383 	 * resource-intensive to repeat twice on every request.
384 	 */
385 	if (req->oldptr == 0) {
386 		n = udbinfo.ipi_count;
387 		req->oldidx = 2 * (sizeof xig)
388 			+ (n + n/8) * sizeof(struct xinpcb);
389 		return 0;
390 	}
391 
392 	if (req->newptr != 0)
393 		return EPERM;
394 
395 	/*
396 	 * OK, now we're committed to doing something.
397 	 */
398 	s = splnet();
399 	gencnt = udbinfo.ipi_gencnt;
400 	n = udbinfo.ipi_count;
401 	splx(s);
402 
403 	xig.xig_len = sizeof xig;
404 	xig.xig_count = n;
405 	xig.xig_gen = gencnt;
406 	xig.xig_sogen = so_gencnt;
407 	error = SYSCTL_OUT(req, &xig, sizeof xig);
408 	if (error)
409 		return error;
410 
411 	inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
412 	if (inp_list == 0)
413 		return ENOMEM;
414 
415 	s = splnet();
416 	for (inp = udbinfo.listhead->lh_first, i = 0; inp && i < n;
417 	     inp = inp->inp_list.le_next) {
418 		if (inp->inp_gencnt <= gencnt && !prison_xinpcb(req->p, inp))
419 			inp_list[i++] = inp;
420 	}
421 	splx(s);
422 	n = i;
423 
424 	error = 0;
425 	for (i = 0; i < n; i++) {
426 		inp = inp_list[i];
427 		if (inp->inp_gencnt <= gencnt) {
428 			struct xinpcb xi;
429 			xi.xi_len = sizeof xi;
430 			/* XXX should avoid extra copy */
431 			bcopy(inp, &xi.xi_inp, sizeof *inp);
432 			if (inp->inp_socket)
433 				sotoxsocket(inp->inp_socket, &xi.xi_socket);
434 			error = SYSCTL_OUT(req, &xi, sizeof xi);
435 		}
436 	}
437 	if (!error) {
438 		/*
439 		 * Give the user an updated idea of our state.
440 		 * If the generation differs from what we told
441 		 * her before, she knows that something happened
442 		 * while we were processing this request, and it
443 		 * might be necessary to retry.
444 		 */
445 		s = splnet();
446 		xig.xig_gen = udbinfo.ipi_gencnt;
447 		xig.xig_sogen = so_gencnt;
448 		xig.xig_count = udbinfo.ipi_count;
449 		splx(s);
450 		error = SYSCTL_OUT(req, &xig, sizeof xig);
451 	}
452 	free(inp_list, M_TEMP);
453 	return error;
454 }
455 
456 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
457 	    udp_pcblist, "S,xinpcb", "List of active UDP sockets");
458 
459 static int
460 udp_getcred SYSCTL_HANDLER_ARGS
461 {
462 	struct sockaddr_in addrs[2];
463 	struct inpcb *inp;
464 	int error, s;
465 
466 	error = suser(req->p);
467 	if (error)
468 		return (error);
469 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
470 	if (error)
471 		return (error);
472 	s = splnet();
473 	inp = in_pcblookup_hash(&udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
474 	    addrs[0].sin_addr, addrs[0].sin_port, 1);
475 	if (inp == NULL || inp->inp_socket == NULL) {
476 		error = ENOENT;
477 		goto out;
478 	}
479 	error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
480 out:
481 	splx(s);
482 	return (error);
483 }
484 
485 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW,
486     0, 0, udp_getcred, "S,ucred", "Get the ucred of a UDP connection");
487 
488 static int
489 udp_output(inp, m, addr, control, p)
490 	register struct inpcb *inp;
491 	register struct mbuf *m;
492 	struct sockaddr *addr;
493 	struct mbuf *control;
494 	struct proc *p;
495 {
496 	register struct udpiphdr *ui;
497 	register int len = m->m_pkthdr.len;
498 	struct in_addr laddr;
499 	struct sockaddr_in *sin;
500 	int s = 0, error = 0;
501 
502 	if (control)
503 		m_freem(control);		/* XXX */
504 
505 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
506 		error = EMSGSIZE;
507 		goto release;
508 	}
509 
510 	if (addr) {
511 		sin = (struct sockaddr_in *)addr;
512 		prison_remote_ip(p, 0, &sin->sin_addr.s_addr);
513 		laddr = inp->inp_laddr;
514 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
515 			error = EISCONN;
516 			goto release;
517 		}
518 		/*
519 		 * Must block input while temporarily connected.
520 		 */
521 		s = splnet();
522 		error = in_pcbconnect(inp, addr, p);
523 		if (error) {
524 			splx(s);
525 			goto release;
526 		}
527 	} else {
528 		if (inp->inp_faddr.s_addr == INADDR_ANY) {
529 			error = ENOTCONN;
530 			goto release;
531 		}
532 	}
533 	/*
534 	 * Calculate data length and get a mbuf
535 	 * for UDP and IP headers.
536 	 */
537 	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
538 	if (m == 0) {
539 		error = ENOBUFS;
540 		if (addr)
541 			splx(s);
542 		goto release;
543 	}
544 
545 	/*
546 	 * Fill in mbuf with extended UDP header
547 	 * and addresses and length put into network format.
548 	 */
549 	ui = mtod(m, struct udpiphdr *);
550 	bzero(ui->ui_x1, sizeof(ui->ui_x1));
551 	ui->ui_pr = IPPROTO_UDP;
552 	ui->ui_len = htons((u_short)len + sizeof (struct udphdr));
553 	ui->ui_src = inp->inp_laddr;
554 	ui->ui_dst = inp->inp_faddr;
555 	ui->ui_sport = inp->inp_lport;
556 	ui->ui_dport = inp->inp_fport;
557 	ui->ui_ulen = ui->ui_len;
558 
559 	/*
560 	 * Stuff checksum and output datagram.
561 	 */
562 	ui->ui_sum = 0;
563 	if (udpcksum) {
564 	    if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0)
565 		ui->ui_sum = 0xffff;
566 	}
567 	((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
568 	((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;	/* XXX */
569 	((struct ip *)ui)->ip_tos = inp->inp_ip_tos;	/* XXX */
570 	udpstat.udps_opackets++;
571 	error = ip_output(m, inp->inp_options, &inp->inp_route,
572 	    inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST),
573 	    inp->inp_moptions);
574 
575 	if (addr) {
576 		in_pcbdisconnect(inp);
577 		inp->inp_laddr = laddr;	/* XXX rehash? */
578 		splx(s);
579 	}
580 	return (error);
581 
582 release:
583 	m_freem(m);
584 	return (error);
585 }
586 
587 u_long	udp_sendspace = 9216;		/* really max datagram size */
588 					/* 40 1K datagrams */
589 SYSCTL_INT(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
590     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
591 
592 u_long	udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
593 SYSCTL_INT(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
594     &udp_recvspace, 0, "Maximum incoming UDP datagram size");
595 
596 static int
597 udp_abort(struct socket *so)
598 {
599 	struct inpcb *inp;
600 	int s;
601 
602 	inp = sotoinpcb(so);
603 	if (inp == 0)
604 		return EINVAL;	/* ??? possible? panic instead? */
605 	soisdisconnected(so);
606 	s = splnet();
607 	in_pcbdetach(inp);
608 	splx(s);
609 	return 0;
610 }
611 
612 static int
613 udp_attach(struct socket *so, int proto, struct proc *p)
614 {
615 	struct inpcb *inp;
616 	int s, error;
617 
618 	inp = sotoinpcb(so);
619 	if (inp != 0)
620 		return EINVAL;
621 
622 	s = splnet();
623 	error = in_pcballoc(so, &udbinfo, p);
624 	splx(s);
625 	if (error)
626 		return error;
627 	error = soreserve(so, udp_sendspace, udp_recvspace);
628 	if (error)
629 		return error;
630 	((struct inpcb *) so->so_pcb)->inp_ip_ttl = ip_defttl;
631 	return 0;
632 }
633 
634 static int
635 udp_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
636 {
637 	struct inpcb *inp;
638 	int s, error;
639 
640 	inp = sotoinpcb(so);
641 	if (inp == 0)
642 		return EINVAL;
643 	s = splnet();
644 	error = in_pcbbind(inp, nam, p);
645 	splx(s);
646 	return error;
647 }
648 
649 static int
650 udp_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
651 {
652 	struct inpcb *inp;
653 	int s, error;
654 	struct sockaddr_in *sin;
655 
656 	inp = sotoinpcb(so);
657 	if (inp == 0)
658 		return EINVAL;
659 	if (inp->inp_faddr.s_addr != INADDR_ANY)
660 		return EISCONN;
661 	s = splnet();
662 	sin = (struct sockaddr_in *)nam;
663 	prison_remote_ip(p, 0, &sin->sin_addr.s_addr);
664 	error = in_pcbconnect(inp, nam, p);
665 	splx(s);
666 	if (error == 0)
667 		soisconnected(so);
668 	return error;
669 }
670 
671 static int
672 udp_detach(struct socket *so)
673 {
674 	struct inpcb *inp;
675 	int s;
676 
677 	inp = sotoinpcb(so);
678 	if (inp == 0)
679 		return EINVAL;
680 	s = splnet();
681 	in_pcbdetach(inp);
682 	splx(s);
683 	return 0;
684 }
685 
686 static int
687 udp_disconnect(struct socket *so)
688 {
689 	struct inpcb *inp;
690 	int s;
691 
692 	inp = sotoinpcb(so);
693 	if (inp == 0)
694 		return EINVAL;
695 	if (inp->inp_faddr.s_addr == INADDR_ANY)
696 		return ENOTCONN;
697 
698 	s = splnet();
699 	in_pcbdisconnect(inp);
700 	inp->inp_laddr.s_addr = INADDR_ANY;
701 	splx(s);
702 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
703 	return 0;
704 }
705 
706 static int
707 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
708 	    struct mbuf *control, struct proc *p)
709 {
710 	struct inpcb *inp;
711 
712 	inp = sotoinpcb(so);
713 	if (inp == 0) {
714 		m_freem(m);
715 		return EINVAL;
716 	}
717 	return udp_output(inp, m, addr, control, p);
718 }
719 
720 int
721 udp_shutdown(struct socket *so)
722 {
723 	struct inpcb *inp;
724 
725 	inp = sotoinpcb(so);
726 	if (inp == 0)
727 		return EINVAL;
728 	socantsendmore(so);
729 	return 0;
730 }
731 
732 struct pr_usrreqs udp_usrreqs = {
733 	udp_abort, pru_accept_notsupp, udp_attach, udp_bind, udp_connect,
734 	pru_connect2_notsupp, in_control, udp_detach, udp_disconnect,
735 	pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp,
736 	pru_rcvoob_notsupp, udp_send, pru_sense_null, udp_shutdown,
737 	in_setsockaddr, sosend, soreceive, sopoll
738 };
739 
740