xref: /freebsd/sys/netinet/udp_usrreq.c (revision a2f733abcff64628b7771a47089628b7327a88bd)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
5  *	The Regents of the University of California.
6  * Copyright (c) 2008 Robert N. M. Watson
7  * Copyright (c) 2010-2011 Juniper Networks, Inc.
8  * Copyright (c) 2014 Kevin Lo
9  * All rights reserved.
10  *
11  * Portions of this software were developed by Robert N. M. Watson under
12  * contract to Juniper Networks, Inc.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #include "opt_inet.h"
41 #include "opt_inet6.h"
42 #include "opt_ipsec.h"
43 #include "opt_route.h"
44 #include "opt_rss.h"
45 
46 #include <sys/param.h>
47 #include <sys/domain.h>
48 #include <sys/eventhandler.h>
49 #include <sys/jail.h>
50 #include <sys/kernel.h>
51 #include <sys/lock.h>
52 #include <sys/malloc.h>
53 #include <sys/mbuf.h>
54 #include <sys/priv.h>
55 #include <sys/proc.h>
56 #include <sys/protosw.h>
57 #include <sys/sdt.h>
58 #include <sys/signalvar.h>
59 #include <sys/socket.h>
60 #include <sys/socketvar.h>
61 #include <sys/sx.h>
62 #include <sys/sysctl.h>
63 #include <sys/syslog.h>
64 #include <sys/systm.h>
65 
66 #include <vm/uma.h>
67 
68 #include <net/if.h>
69 #include <net/if_var.h>
70 #include <net/route.h>
71 #include <net/route/nhop.h>
72 #include <net/rss_config.h>
73 
74 #include <netinet/in.h>
75 #include <netinet/in_kdtrace.h>
76 #include <netinet/in_fib.h>
77 #include <netinet/in_pcb.h>
78 #include <netinet/in_systm.h>
79 #include <netinet/in_var.h>
80 #include <netinet/ip.h>
81 #ifdef INET6
82 #include <netinet/ip6.h>
83 #endif
84 #include <netinet/ip_icmp.h>
85 #include <netinet/icmp_var.h>
86 #include <netinet/ip_var.h>
87 #include <netinet/ip_options.h>
88 #ifdef INET6
89 #include <netinet6/ip6_var.h>
90 #endif
91 #include <netinet/udp.h>
92 #include <netinet/udp_var.h>
93 #include <netinet/udplite.h>
94 #include <netinet/in_rss.h>
95 
96 #include <netipsec/ipsec_support.h>
97 
98 #include <machine/in_cksum.h>
99 
100 #include <security/mac/mac_framework.h>
101 
102 /*
103  * UDP and UDP-Lite protocols implementation.
104  * Per RFC 768, August, 1980.
105  * Per RFC 3828, July, 2004.
106  */
107 
108 /*
109  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
110  * removes the only data integrity mechanism for packets and malformed
111  * packets that would otherwise be discarded due to bad checksums, and may
112  * cause problems (especially for NFS data blocks).
113  */
114 VNET_DEFINE(int, udp_cksum) = 1;
115 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_VNET | CTLFLAG_RW,
116     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
117 
118 VNET_DEFINE(int, udp_log_in_vain) = 0;
119 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_VNET | CTLFLAG_RW,
120     &VNET_NAME(udp_log_in_vain), 0, "Log all incoming UDP packets");
121 
122 VNET_DEFINE(int, udp_blackhole) = 0;
123 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_VNET | CTLFLAG_RW,
124     &VNET_NAME(udp_blackhole), 0,
125     "Do not send port unreachables for refused connects");
126 VNET_DEFINE(bool, udp_blackhole_local) = false;
127 SYSCTL_BOOL(_net_inet_udp, OID_AUTO, blackhole_local, CTLFLAG_VNET |
128     CTLFLAG_RW, &VNET_NAME(udp_blackhole_local), false,
129     "Enforce net.inet.udp.blackhole for locally originated packets");
130 
131 u_long	udp_sendspace = 9216;		/* really max datagram size */
132 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
133     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
134 
135 u_long	udp_recvspace = 40 * (1024 +
136 #ifdef INET6
137 				      sizeof(struct sockaddr_in6)
138 #else
139 				      sizeof(struct sockaddr_in)
140 #endif
141 				      );	/* 40 1K datagrams */
142 
143 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
144     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
145 
146 VNET_DEFINE(struct inpcbinfo, udbinfo);
147 VNET_DEFINE(struct inpcbinfo, ulitecbinfo);
148 
149 #ifndef UDBHASHSIZE
150 #define	UDBHASHSIZE	128
151 #endif
152 
153 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);		/* from udp_var.h */
154 VNET_PCPUSTAT_SYSINIT(udpstat);
155 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
156     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
157 
158 #ifdef VIMAGE
159 VNET_PCPUSTAT_SYSUNINIT(udpstat);
160 #endif /* VIMAGE */
161 #ifdef INET
162 static void	udp_detach(struct socket *so);
163 #endif
164 
165 INPCBSTORAGE_DEFINE(udpcbstor, udpcb, "udpinp", "udp_inpcb", "udp", "udphash");
166 INPCBSTORAGE_DEFINE(udplitecbstor, udpcb, "udpliteinp", "udplite_inpcb",
167     "udplite", "udplitehash");
168 
169 static void
170 udp_vnet_init(void *arg __unused)
171 {
172 
173 	/*
174 	 * For now default to 2-tuple UDP hashing - until the fragment
175 	 * reassembly code can also update the flowid.
176 	 *
177 	 * Once we can calculate the flowid that way and re-establish
178 	 * a 4-tuple, flip this to 4-tuple.
179 	 */
180 	in_pcbinfo_init(&V_udbinfo, &udpcbstor, UDBHASHSIZE, UDBHASHSIZE);
181 	/* Additional pcbinfo for UDP-Lite */
182 	in_pcbinfo_init(&V_ulitecbinfo, &udplitecbstor, UDBHASHSIZE,
183 	    UDBHASHSIZE);
184 }
185 VNET_SYSINIT(udp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH,
186     udp_vnet_init, NULL);
187 
188 /*
189  * Kernel module interface for updating udpstat.  The argument is an index
190  * into udpstat treated as an array of u_long.  While this encodes the
191  * general layout of udpstat into the caller, it doesn't encode its location,
192  * so that future changes to add, for example, per-CPU stats support won't
193  * cause binary compatibility problems for kernel modules.
194  */
195 void
196 kmod_udpstat_inc(int statnum)
197 {
198 
199 	counter_u64_add(VNET(udpstat)[statnum], 1);
200 }
201 
202 #ifdef VIMAGE
203 static void
204 udp_destroy(void *unused __unused)
205 {
206 
207 	in_pcbinfo_destroy(&V_udbinfo);
208 	in_pcbinfo_destroy(&V_ulitecbinfo);
209 }
210 VNET_SYSUNINIT(udp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udp_destroy, NULL);
211 #endif
212 
213 #ifdef INET
214 /*
215  * Subroutine of udp_input(), which appends the provided mbuf chain to the
216  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
217  * contains the source address.  If the socket ends up being an IPv6 socket,
218  * udp_append() will convert to a sockaddr_in6 before passing the address
219  * into the socket code.
220  *
221  * In the normal case udp_append() will return 0, indicating that you
222  * must unlock the inp. However if a tunneling protocol is in place we increment
223  * the inpcb refcnt and unlock the inp, on return from the tunneling protocol we
224  * then decrement the reference count. If the inp_rele returns 1, indicating the
225  * inp is gone, we return that to the caller to tell them *not* to unlock
226  * the inp. In the case of multi-cast this will cause the distribution
227  * to stop (though most tunneling protocols known currently do *not* use
228  * multicast).
229  */
230 static int
231 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
232     struct sockaddr_in *udp_in)
233 {
234 	struct sockaddr *append_sa;
235 	struct socket *so;
236 	struct mbuf *tmpopts, *opts = NULL;
237 #ifdef INET6
238 	struct sockaddr_in6 udp_in6;
239 #endif
240 	struct udpcb *up;
241 	bool filtered;
242 
243 	INP_LOCK_ASSERT(inp);
244 
245 	/*
246 	 * Engage the tunneling protocol.
247 	 */
248 	up = intoudpcb(inp);
249 	if (up->u_tun_func != NULL) {
250 		in_pcbref(inp);
251 		INP_RUNLOCK(inp);
252 		filtered = (*up->u_tun_func)(n, off, inp, (struct sockaddr *)&udp_in[0],
253 		    up->u_tun_ctx);
254 		INP_RLOCK(inp);
255 		if (filtered)
256 			return (in_pcbrele_rlocked(inp));
257 	}
258 
259 	off += sizeof(struct udphdr);
260 
261 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
262 	/* Check AH/ESP integrity. */
263 	if (IPSEC_ENABLED(ipv4) &&
264 	    IPSEC_CHECK_POLICY(ipv4, n, inp) != 0) {
265 		m_freem(n);
266 		return (0);
267 	}
268 	if (up->u_flags & UF_ESPINUDP) {/* IPSec UDP encaps. */
269 		if (IPSEC_ENABLED(ipv4) &&
270 		    UDPENCAP_INPUT(n, off, AF_INET) != 0)
271 			return (0);	/* Consumed. */
272 	}
273 #endif /* IPSEC */
274 #ifdef MAC
275 	if (mac_inpcb_check_deliver(inp, n) != 0) {
276 		m_freem(n);
277 		return (0);
278 	}
279 #endif /* MAC */
280 	if (inp->inp_flags & INP_CONTROLOPTS ||
281 	    inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
282 #ifdef INET6
283 		if (inp->inp_vflag & INP_IPV6)
284 			(void)ip6_savecontrol_v4(inp, n, &opts, NULL);
285 		else
286 #endif /* INET6 */
287 			ip_savecontrol(inp, &opts, ip, n);
288 	}
289 	if ((inp->inp_vflag & INP_IPV4) && (inp->inp_flags2 & INP_ORIGDSTADDR)) {
290 		tmpopts = sbcreatecontrol(&udp_in[1],
291 		    sizeof(struct sockaddr_in), IP_ORIGDSTADDR, IPPROTO_IP,
292 		    M_NOWAIT);
293 		if (tmpopts) {
294 			if (opts) {
295 				tmpopts->m_next = opts;
296 				opts = tmpopts;
297 			} else
298 				opts = tmpopts;
299 		}
300 	}
301 #ifdef INET6
302 	if (inp->inp_vflag & INP_IPV6) {
303 		bzero(&udp_in6, sizeof(udp_in6));
304 		udp_in6.sin6_len = sizeof(udp_in6);
305 		udp_in6.sin6_family = AF_INET6;
306 		in6_sin_2_v4mapsin6(&udp_in[0], &udp_in6);
307 		append_sa = (struct sockaddr *)&udp_in6;
308 	} else
309 #endif /* INET6 */
310 		append_sa = (struct sockaddr *)&udp_in[0];
311 	m_adj(n, off);
312 
313 	so = inp->inp_socket;
314 	SOCKBUF_LOCK(&so->so_rcv);
315 	if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
316 		soroverflow_locked(so);
317 		m_freem(n);
318 		if (opts)
319 			m_freem(opts);
320 		UDPSTAT_INC(udps_fullsock);
321 	} else
322 		sorwakeup_locked(so);
323 	return (0);
324 }
325 
326 static bool
327 udp_multi_match(const struct inpcb *inp, void *v)
328 {
329 	struct ip *ip = v;
330 	struct udphdr *uh = (struct udphdr *)(ip + 1);
331 
332 	if (inp->inp_lport != uh->uh_dport)
333 		return (false);
334 #ifdef INET6
335 	if ((inp->inp_vflag & INP_IPV4) == 0)
336 		return (false);
337 #endif
338 	if (inp->inp_laddr.s_addr != INADDR_ANY &&
339 	    inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
340 		return (false);
341 	if (inp->inp_faddr.s_addr != INADDR_ANY &&
342 	    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
343 		return (false);
344 	if (inp->inp_fport != 0 &&
345 	    inp->inp_fport != uh->uh_sport)
346 		return (false);
347 
348 	return (true);
349 }
350 
351 static int
352 udp_multi_input(struct mbuf *m, int proto, struct sockaddr_in *udp_in)
353 {
354 	struct ip *ip = mtod(m, struct ip *);
355 	struct inpcb_iterator inpi = INP_ITERATOR(udp_get_inpcbinfo(proto),
356 	    INPLOOKUP_RLOCKPCB, udp_multi_match, ip);
357 #ifdef KDTRACE_HOOKS
358 	struct udphdr *uh = (struct udphdr *)(ip + 1);
359 #endif
360 	struct inpcb *inp;
361 	struct mbuf *n;
362 	int appends = 0;
363 
364 	MPASS(ip->ip_hl == sizeof(struct ip) >> 2);
365 
366 	while ((inp = inp_next(&inpi)) != NULL) {
367 		/*
368 		 * XXXRW: Because we weren't holding either the inpcb
369 		 * or the hash lock when we checked for a match
370 		 * before, we should probably recheck now that the
371 		 * inpcb lock is held.
372 		 */
373 		/*
374 		 * Handle socket delivery policy for any-source
375 		 * and source-specific multicast. [RFC3678]
376 		 */
377 		if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
378 			struct ip_moptions	*imo;
379 			struct sockaddr_in	 group;
380 			int			 blocked;
381 
382 			imo = inp->inp_moptions;
383 			if (imo == NULL)
384 				continue;
385 			bzero(&group, sizeof(struct sockaddr_in));
386 			group.sin_len = sizeof(struct sockaddr_in);
387 			group.sin_family = AF_INET;
388 			group.sin_addr = ip->ip_dst;
389 
390 			blocked = imo_multi_filter(imo, m->m_pkthdr.rcvif,
391 				(struct sockaddr *)&group,
392 				(struct sockaddr *)&udp_in[0]);
393 			if (blocked != MCAST_PASS) {
394 				if (blocked == MCAST_NOTGMEMBER)
395 					IPSTAT_INC(ips_notmember);
396 				if (blocked == MCAST_NOTSMEMBER ||
397 				    blocked == MCAST_MUTED)
398 					UDPSTAT_INC(udps_filtermcast);
399 				continue;
400 			}
401 		}
402 		if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
403 			if (proto == IPPROTO_UDPLITE)
404 				UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
405 			else
406 				UDP_PROBE(receive, NULL, inp, ip, inp, uh);
407 			if (udp_append(inp, ip, n, sizeof(struct ip), udp_in)) {
408 				break;
409 			} else
410 				appends++;
411 		}
412 		/*
413 		 * Don't look for additional matches if this one does
414 		 * not have either the SO_REUSEPORT or SO_REUSEADDR
415 		 * socket options set.  This heuristic avoids
416 		 * searching through all pcbs in the common case of a
417 		 * non-shared port.  It assumes that an application
418 		 * will never clear these options after setting them.
419 		 */
420 		if ((inp->inp_socket->so_options &
421 		    (SO_REUSEPORT|SO_REUSEPORT_LB|SO_REUSEADDR)) == 0) {
422 			INP_RUNLOCK(inp);
423 			break;
424 		}
425 	}
426 
427 	if (appends == 0) {
428 		/*
429 		 * No matching pcb found; discard datagram.  (No need
430 		 * to send an ICMP Port Unreachable for a broadcast
431 		 * or multicast datgram.)
432 		 */
433 		UDPSTAT_INC(udps_noport);
434 		if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)))
435 			UDPSTAT_INC(udps_noportmcast);
436 		else
437 			UDPSTAT_INC(udps_noportbcast);
438 	}
439 	m_freem(m);
440 
441 	return (IPPROTO_DONE);
442 }
443 
444 static int
445 udp_input(struct mbuf **mp, int *offp, int proto)
446 {
447 	struct ip *ip;
448 	struct udphdr *uh;
449 	struct ifnet *ifp;
450 	struct inpcb *inp;
451 	uint16_t len, ip_len;
452 	struct inpcbinfo *pcbinfo;
453 	struct sockaddr_in udp_in[2];
454 	struct mbuf *m;
455 	struct m_tag *fwd_tag;
456 	int cscov_partial, iphlen;
457 
458 	m = *mp;
459 	iphlen = *offp;
460 	ifp = m->m_pkthdr.rcvif;
461 	*mp = NULL;
462 	UDPSTAT_INC(udps_ipackets);
463 
464 	/*
465 	 * Strip IP options, if any; should skip this, make available to
466 	 * user, and use on returned packets, but we don't yet have a way to
467 	 * check the checksum with options still present.
468 	 */
469 	if (iphlen > sizeof (struct ip)) {
470 		ip_stripoptions(m);
471 		iphlen = sizeof(struct ip);
472 	}
473 
474 	/*
475 	 * Get IP and UDP header together in first mbuf.
476 	 */
477 	if (m->m_len < iphlen + sizeof(struct udphdr)) {
478 		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) {
479 			UDPSTAT_INC(udps_hdrops);
480 			return (IPPROTO_DONE);
481 		}
482 	}
483 	ip = mtod(m, struct ip *);
484 	uh = (struct udphdr *)((caddr_t)ip + iphlen);
485 	cscov_partial = (proto == IPPROTO_UDPLITE) ? 1 : 0;
486 
487 	/*
488 	 * Destination port of 0 is illegal, based on RFC768.
489 	 */
490 	if (uh->uh_dport == 0)
491 		goto badunlocked;
492 
493 	/*
494 	 * Construct sockaddr format source address.  Stuff source address
495 	 * and datagram in user buffer.
496 	 */
497 	bzero(&udp_in[0], sizeof(struct sockaddr_in) * 2);
498 	udp_in[0].sin_len = sizeof(struct sockaddr_in);
499 	udp_in[0].sin_family = AF_INET;
500 	udp_in[0].sin_port = uh->uh_sport;
501 	udp_in[0].sin_addr = ip->ip_src;
502 	udp_in[1].sin_len = sizeof(struct sockaddr_in);
503 	udp_in[1].sin_family = AF_INET;
504 	udp_in[1].sin_port = uh->uh_dport;
505 	udp_in[1].sin_addr = ip->ip_dst;
506 
507 	/*
508 	 * Make mbuf data length reflect UDP length.  If not enough data to
509 	 * reflect UDP length, drop.
510 	 */
511 	len = ntohs((u_short)uh->uh_ulen);
512 	ip_len = ntohs(ip->ip_len) - iphlen;
513 	if (proto == IPPROTO_UDPLITE && (len == 0 || len == ip_len)) {
514 		/* Zero means checksum over the complete packet. */
515 		if (len == 0)
516 			len = ip_len;
517 		cscov_partial = 0;
518 	}
519 	if (ip_len != len) {
520 		if (len > ip_len || len < sizeof(struct udphdr)) {
521 			UDPSTAT_INC(udps_badlen);
522 			goto badunlocked;
523 		}
524 		if (proto == IPPROTO_UDP)
525 			m_adj(m, len - ip_len);
526 	}
527 
528 	/*
529 	 * Checksum extended UDP header and data.
530 	 */
531 	if (uh->uh_sum) {
532 		u_short uh_sum;
533 
534 		if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
535 		    !cscov_partial) {
536 			if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
537 				uh_sum = m->m_pkthdr.csum_data;
538 			else
539 				uh_sum = in_pseudo(ip->ip_src.s_addr,
540 				    ip->ip_dst.s_addr, htonl((u_short)len +
541 				    m->m_pkthdr.csum_data + proto));
542 			uh_sum ^= 0xffff;
543 		} else {
544 			char b[offsetof(struct ipovly, ih_src)];
545 			struct ipovly *ipov = (struct ipovly *)ip;
546 
547 			bcopy(ipov, b, sizeof(b));
548 			bzero(ipov, sizeof(ipov->ih_x1));
549 			ipov->ih_len = (proto == IPPROTO_UDP) ?
550 			    uh->uh_ulen : htons(ip_len);
551 			uh_sum = in_cksum(m, len + sizeof (struct ip));
552 			bcopy(b, ipov, sizeof(b));
553 		}
554 		if (uh_sum) {
555 			UDPSTAT_INC(udps_badsum);
556 			m_freem(m);
557 			return (IPPROTO_DONE);
558 		}
559 	} else {
560 		if (proto == IPPROTO_UDP) {
561 			UDPSTAT_INC(udps_nosum);
562 		} else {
563 			/* UDPLite requires a checksum */
564 			/* XXX: What is the right UDPLite MIB counter here? */
565 			m_freem(m);
566 			return (IPPROTO_DONE);
567 		}
568 	}
569 
570 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
571 	    in_broadcast(ip->ip_dst, ifp))
572 		return (udp_multi_input(m, proto, udp_in));
573 
574 	pcbinfo = udp_get_inpcbinfo(proto);
575 
576 	/*
577 	 * Locate pcb for datagram.
578 	 *
579 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
580 	 */
581 	if ((m->m_flags & M_IP_NEXTHOP) &&
582 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
583 		struct sockaddr_in *next_hop;
584 
585 		next_hop = (struct sockaddr_in *)(fwd_tag + 1);
586 
587 		/*
588 		 * Transparently forwarded. Pretend to be the destination.
589 		 * Already got one like this?
590 		 */
591 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
592 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
593 		if (!inp) {
594 			/*
595 			 * It's new.  Try to find the ambushing socket.
596 			 * Because we've rewritten the destination address,
597 			 * any hardware-generated hash is ignored.
598 			 */
599 			inp = in_pcblookup(pcbinfo, ip->ip_src,
600 			    uh->uh_sport, next_hop->sin_addr,
601 			    next_hop->sin_port ? htons(next_hop->sin_port) :
602 			    uh->uh_dport, INPLOOKUP_WILDCARD |
603 			    INPLOOKUP_RLOCKPCB, ifp);
604 		}
605 		/* Remove the tag from the packet. We don't need it anymore. */
606 		m_tag_delete(m, fwd_tag);
607 		m->m_flags &= ~M_IP_NEXTHOP;
608 	} else
609 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
610 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
611 		    INPLOOKUP_RLOCKPCB, ifp, m);
612 	if (inp == NULL) {
613 		if (V_udp_log_in_vain) {
614 			char src[INET_ADDRSTRLEN];
615 			char dst[INET_ADDRSTRLEN];
616 
617 			log(LOG_INFO,
618 			    "Connection attempt to UDP %s:%d from %s:%d\n",
619 			    inet_ntoa_r(ip->ip_dst, dst), ntohs(uh->uh_dport),
620 			    inet_ntoa_r(ip->ip_src, src), ntohs(uh->uh_sport));
621 		}
622 		if (proto == IPPROTO_UDPLITE)
623 			UDPLITE_PROBE(receive, NULL, NULL, ip, NULL, uh);
624 		else
625 			UDP_PROBE(receive, NULL, NULL, ip, NULL, uh);
626 		UDPSTAT_INC(udps_noport);
627 		if (m->m_flags & (M_BCAST | M_MCAST)) {
628 			UDPSTAT_INC(udps_noportbcast);
629 			goto badunlocked;
630 		}
631 		if (V_udp_blackhole && (V_udp_blackhole_local ||
632 		    !in_localip(ip->ip_src)))
633 			goto badunlocked;
634 		if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
635 			goto badunlocked;
636 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
637 		return (IPPROTO_DONE);
638 	}
639 
640 	/*
641 	 * Check the minimum TTL for socket.
642 	 */
643 	INP_RLOCK_ASSERT(inp);
644 	if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
645 		if (proto == IPPROTO_UDPLITE)
646 			UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
647 		else
648 			UDP_PROBE(receive, NULL, inp, ip, inp, uh);
649 		INP_RUNLOCK(inp);
650 		m_freem(m);
651 		return (IPPROTO_DONE);
652 	}
653 	if (cscov_partial) {
654 		struct udpcb *up;
655 
656 		up = intoudpcb(inp);
657 		if (up->u_rxcslen == 0 || up->u_rxcslen > len) {
658 			INP_RUNLOCK(inp);
659 			m_freem(m);
660 			return (IPPROTO_DONE);
661 		}
662 	}
663 
664 	if (proto == IPPROTO_UDPLITE)
665 		UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
666 	else
667 		UDP_PROBE(receive, NULL, inp, ip, inp, uh);
668 	if (udp_append(inp, ip, m, iphlen, udp_in) == 0)
669 		INP_RUNLOCK(inp);
670 	return (IPPROTO_DONE);
671 
672 badunlocked:
673 	m_freem(m);
674 	return (IPPROTO_DONE);
675 }
676 #endif /* INET */
677 
678 /*
679  * Notify a udp user of an asynchronous error; just wake up so that they can
680  * collect error status.
681  */
682 struct inpcb *
683 udp_notify(struct inpcb *inp, int errno)
684 {
685 
686 	INP_WLOCK_ASSERT(inp);
687 	if ((errno == EHOSTUNREACH || errno == ENETUNREACH ||
688 	     errno == EHOSTDOWN) && inp->inp_route.ro_nh) {
689 		NH_FREE(inp->inp_route.ro_nh);
690 		inp->inp_route.ro_nh = (struct nhop_object *)NULL;
691 	}
692 
693 	inp->inp_socket->so_error = errno;
694 	sorwakeup(inp->inp_socket);
695 	sowwakeup(inp->inp_socket);
696 	return (inp);
697 }
698 
699 #ifdef INET
700 static void
701 udp_common_ctlinput(struct icmp *icmp, struct inpcbinfo *pcbinfo)
702 {
703 	struct ip *ip = &icmp->icmp_ip;
704 	struct udphdr *uh;
705 	struct inpcb *inp;
706 
707 	if (icmp_errmap(icmp) == 0)
708 		return;
709 
710 	uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
711 	inp = in_pcblookup(pcbinfo, ip->ip_dst, uh->uh_dport, ip->ip_src,
712 	    uh->uh_sport, INPLOOKUP_WLOCKPCB, NULL);
713 	if (inp != NULL) {
714 		INP_WLOCK_ASSERT(inp);
715 		if (inp->inp_socket != NULL)
716 			udp_notify(inp, icmp_errmap(icmp));
717 		INP_WUNLOCK(inp);
718 	} else {
719 		inp = in_pcblookup(pcbinfo, ip->ip_dst, uh->uh_dport,
720 		    ip->ip_src, uh->uh_sport,
721 		    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
722 		if (inp != NULL) {
723 			struct udpcb *up;
724 			udp_tun_icmp_t *func;
725 
726 			up = intoudpcb(inp);
727 			func = up->u_icmp_func;
728 			INP_RUNLOCK(inp);
729 			if (func != NULL)
730 				func(icmp);
731 		}
732 	}
733 }
734 
735 static void
736 udp_ctlinput(struct icmp *icmp)
737 {
738 
739 	return (udp_common_ctlinput(icmp, &V_udbinfo));
740 }
741 
742 static void
743 udplite_ctlinput(struct icmp *icmp)
744 {
745 
746 	return (udp_common_ctlinput(icmp, &V_ulitecbinfo));
747 }
748 #endif /* INET */
749 
750 static int
751 udp_pcblist(SYSCTL_HANDLER_ARGS)
752 {
753 	struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_udbinfo,
754 	    INPLOOKUP_RLOCKPCB);
755 	struct xinpgen xig;
756 	struct inpcb *inp;
757 	int error;
758 
759 	if (req->newptr != 0)
760 		return (EPERM);
761 
762 	if (req->oldptr == 0) {
763 		int n;
764 
765 		n = V_udbinfo.ipi_count;
766 		n += imax(n / 8, 10);
767 		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
768 		return (0);
769 	}
770 
771 	if ((error = sysctl_wire_old_buffer(req, 0)) != 0)
772 		return (error);
773 
774 	bzero(&xig, sizeof(xig));
775 	xig.xig_len = sizeof xig;
776 	xig.xig_count = V_udbinfo.ipi_count;
777 	xig.xig_gen = V_udbinfo.ipi_gencnt;
778 	xig.xig_sogen = so_gencnt;
779 	error = SYSCTL_OUT(req, &xig, sizeof xig);
780 	if (error)
781 		return (error);
782 
783 	while ((inp = inp_next(&inpi)) != NULL) {
784 		if (inp->inp_gencnt <= xig.xig_gen &&
785 		    cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
786 			struct xinpcb xi;
787 
788 			in_pcbtoxinpcb(inp, &xi);
789 			error = SYSCTL_OUT(req, &xi, sizeof xi);
790 			if (error) {
791 				INP_RUNLOCK(inp);
792 				break;
793 			}
794 		}
795 	}
796 
797 	if (!error) {
798 		/*
799 		 * Give the user an updated idea of our state.  If the
800 		 * generation differs from what we told her before, she knows
801 		 * that something happened while we were processing this
802 		 * request, and it might be necessary to retry.
803 		 */
804 		xig.xig_gen = V_udbinfo.ipi_gencnt;
805 		xig.xig_sogen = so_gencnt;
806 		xig.xig_count = V_udbinfo.ipi_count;
807 		error = SYSCTL_OUT(req, &xig, sizeof xig);
808 	}
809 
810 	return (error);
811 }
812 
813 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
814     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
815     udp_pcblist, "S,xinpcb",
816     "List of active UDP sockets");
817 
818 #ifdef INET
819 static int
820 udp_getcred(SYSCTL_HANDLER_ARGS)
821 {
822 	struct xucred xuc;
823 	struct sockaddr_in addrs[2];
824 	struct epoch_tracker et;
825 	struct inpcb *inp;
826 	int error;
827 
828 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
829 	if (error)
830 		return (error);
831 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
832 	if (error)
833 		return (error);
834 	NET_EPOCH_ENTER(et);
835 	inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
836 	    addrs[0].sin_addr, addrs[0].sin_port,
837 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
838 	NET_EPOCH_EXIT(et);
839 	if (inp != NULL) {
840 		INP_RLOCK_ASSERT(inp);
841 		if (inp->inp_socket == NULL)
842 			error = ENOENT;
843 		if (error == 0)
844 			error = cr_canseeinpcb(req->td->td_ucred, inp);
845 		if (error == 0)
846 			cru2x(inp->inp_cred, &xuc);
847 		INP_RUNLOCK(inp);
848 	} else
849 		error = ENOENT;
850 	if (error == 0)
851 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
852 	return (error);
853 }
854 
855 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
856     CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
857     0, 0, udp_getcred, "S,xucred",
858     "Get the xucred of a UDP connection");
859 #endif /* INET */
860 
861 int
862 udp_ctloutput(struct socket *so, struct sockopt *sopt)
863 {
864 	struct inpcb *inp;
865 	struct udpcb *up;
866 	int isudplite, error, optval;
867 
868 	error = 0;
869 	isudplite = (so->so_proto->pr_protocol == IPPROTO_UDPLITE) ? 1 : 0;
870 	inp = sotoinpcb(so);
871 	KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
872 	INP_WLOCK(inp);
873 	if (sopt->sopt_level != so->so_proto->pr_protocol) {
874 #ifdef INET6
875 		if (INP_CHECK_SOCKAF(so, AF_INET6)) {
876 			INP_WUNLOCK(inp);
877 			error = ip6_ctloutput(so, sopt);
878 		}
879 #endif
880 #if defined(INET) && defined(INET6)
881 		else
882 #endif
883 #ifdef INET
884 		{
885 			INP_WUNLOCK(inp);
886 			error = ip_ctloutput(so, sopt);
887 		}
888 #endif
889 		return (error);
890 	}
891 
892 	switch (sopt->sopt_dir) {
893 	case SOPT_SET:
894 		switch (sopt->sopt_name) {
895 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
896 #ifdef INET
897 		case UDP_ENCAP:
898 			if (!INP_CHECK_SOCKAF(so, AF_INET)) {
899 				INP_WUNLOCK(inp);
900 				return (EINVAL);
901 			}
902 			if (!IPSEC_ENABLED(ipv4)) {
903 				INP_WUNLOCK(inp);
904 				return (ENOPROTOOPT);
905 			}
906 			error = UDPENCAP_PCBCTL(inp, sopt);
907 			break;
908 #endif /* INET */
909 #endif /* IPSEC */
910 		case UDPLITE_SEND_CSCOV:
911 		case UDPLITE_RECV_CSCOV:
912 			if (!isudplite) {
913 				INP_WUNLOCK(inp);
914 				error = ENOPROTOOPT;
915 				break;
916 			}
917 			INP_WUNLOCK(inp);
918 			error = sooptcopyin(sopt, &optval, sizeof(optval),
919 			    sizeof(optval));
920 			if (error != 0)
921 				break;
922 			inp = sotoinpcb(so);
923 			KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
924 			INP_WLOCK(inp);
925 			up = intoudpcb(inp);
926 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
927 			if ((optval != 0 && optval < 8) || (optval > 65535)) {
928 				INP_WUNLOCK(inp);
929 				error = EINVAL;
930 				break;
931 			}
932 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
933 				up->u_txcslen = optval;
934 			else
935 				up->u_rxcslen = optval;
936 			INP_WUNLOCK(inp);
937 			break;
938 		default:
939 			INP_WUNLOCK(inp);
940 			error = ENOPROTOOPT;
941 			break;
942 		}
943 		break;
944 	case SOPT_GET:
945 		switch (sopt->sopt_name) {
946 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
947 #ifdef INET
948 		case UDP_ENCAP:
949 			if (!INP_CHECK_SOCKAF(so, AF_INET)) {
950 				INP_WUNLOCK(inp);
951 				return (EINVAL);
952 			}
953 			if (!IPSEC_ENABLED(ipv4)) {
954 				INP_WUNLOCK(inp);
955 				return (ENOPROTOOPT);
956 			}
957 			error = UDPENCAP_PCBCTL(inp, sopt);
958 			break;
959 #endif /* INET */
960 #endif /* IPSEC */
961 		case UDPLITE_SEND_CSCOV:
962 		case UDPLITE_RECV_CSCOV:
963 			if (!isudplite) {
964 				INP_WUNLOCK(inp);
965 				error = ENOPROTOOPT;
966 				break;
967 			}
968 			up = intoudpcb(inp);
969 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
970 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
971 				optval = up->u_txcslen;
972 			else
973 				optval = up->u_rxcslen;
974 			INP_WUNLOCK(inp);
975 			error = sooptcopyout(sopt, &optval, sizeof(optval));
976 			break;
977 		default:
978 			INP_WUNLOCK(inp);
979 			error = ENOPROTOOPT;
980 			break;
981 		}
982 		break;
983 	}
984 	return (error);
985 }
986 
987 #ifdef INET
988 #ifdef INET6
989 /* The logic here is derived from ip6_setpktopt(). See comments there. */
990 static int
991 udp_v4mapped_pktinfo(struct cmsghdr *cm, struct sockaddr_in * src,
992     struct inpcb *inp, int flags)
993 {
994 	struct ifnet *ifp;
995 	struct in6_pktinfo *pktinfo;
996 	struct in_addr ia;
997 
998 	if ((flags & PRUS_IPV6) == 0)
999 		return (0);
1000 
1001 	if (cm->cmsg_level != IPPROTO_IPV6)
1002 		return (0);
1003 
1004 	if  (cm->cmsg_type != IPV6_2292PKTINFO &&
1005 	    cm->cmsg_type != IPV6_PKTINFO)
1006 		return (0);
1007 
1008 	if (cm->cmsg_len !=
1009 	    CMSG_LEN(sizeof(struct in6_pktinfo)))
1010 		return (EINVAL);
1011 
1012 	pktinfo = (struct in6_pktinfo *)CMSG_DATA(cm);
1013 	if (!IN6_IS_ADDR_V4MAPPED(&pktinfo->ipi6_addr) &&
1014 	    !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr))
1015 		return (EINVAL);
1016 
1017 	/* Validate the interface index if specified. */
1018 	if (pktinfo->ipi6_ifindex) {
1019 		struct epoch_tracker et;
1020 
1021 		NET_EPOCH_ENTER(et);
1022 		ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
1023 		NET_EPOCH_EXIT(et);	/* XXXGL: unsafe ifp */
1024 		if (ifp == NULL)
1025 			return (ENXIO);
1026 	} else
1027 		ifp = NULL;
1028 	if (ifp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
1029 		ia.s_addr = pktinfo->ipi6_addr.s6_addr32[3];
1030 		if (in_ifhasaddr(ifp, ia) == 0)
1031 			return (EADDRNOTAVAIL);
1032 	}
1033 
1034 	bzero(src, sizeof(*src));
1035 	src->sin_family = AF_INET;
1036 	src->sin_len = sizeof(*src);
1037 	src->sin_port = inp->inp_lport;
1038 	src->sin_addr.s_addr = pktinfo->ipi6_addr.s6_addr32[3];
1039 
1040 	return (0);
1041 }
1042 #endif	/* INET6 */
1043 
1044 int
1045 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1046     struct mbuf *control, struct thread *td)
1047 {
1048 	struct inpcb *inp;
1049 	struct udpiphdr *ui;
1050 	int len, error = 0;
1051 	struct in_addr faddr, laddr;
1052 	struct cmsghdr *cm;
1053 	struct inpcbinfo *pcbinfo;
1054 	struct sockaddr_in *sin, src;
1055 	struct epoch_tracker et;
1056 	int cscov_partial = 0;
1057 	int ipflags = 0;
1058 	u_short fport, lport;
1059 	u_char tos, vflagsav;
1060 	uint8_t pr;
1061 	uint16_t cscov = 0;
1062 	uint32_t flowid = 0;
1063 	uint8_t flowtype = M_HASHTYPE_NONE;
1064 
1065 	inp = sotoinpcb(so);
1066 	KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1067 
1068 	if (addr != NULL) {
1069 		if (addr->sa_family != AF_INET)
1070 			error = EAFNOSUPPORT;
1071 		else if (addr->sa_len != sizeof(struct sockaddr_in))
1072 			error = EINVAL;
1073 		if (__predict_false(error != 0)) {
1074 			m_freem(control);
1075 			m_freem(m);
1076 			return (error);
1077 		}
1078 	}
1079 
1080 	len = m->m_pkthdr.len;
1081 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1082 		if (control)
1083 			m_freem(control);
1084 		m_freem(m);
1085 		return (EMSGSIZE);
1086 	}
1087 
1088 	src.sin_family = 0;
1089 	sin = (struct sockaddr_in *)addr;
1090 
1091 	/*
1092 	 * udp_send() may need to temporarily bind or connect the current
1093 	 * inpcb.  As such, we don't know up front whether we will need the
1094 	 * pcbinfo lock or not.  Do any work to decide what is needed up
1095 	 * front before acquiring any locks.
1096 	 *
1097 	 * We will need network epoch in either case, to safely lookup into
1098 	 * pcb hash.
1099 	 */
1100 	if (sin == NULL ||
1101 	    (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0) ||
1102 	    (flags & PRUS_IPV6) != 0)
1103 		INP_WLOCK(inp);
1104 	else
1105 		INP_RLOCK(inp);
1106 	NET_EPOCH_ENTER(et);
1107 	tos = inp->inp_ip_tos;
1108 	if (control != NULL) {
1109 		/*
1110 		 * XXX: Currently, we assume all the optional information is
1111 		 * stored in a single mbuf.
1112 		 */
1113 		if (control->m_next) {
1114 			m_freem(control);
1115 			error = EINVAL;
1116 			goto release;
1117 		}
1118 		for (; control->m_len > 0;
1119 		    control->m_data += CMSG_ALIGN(cm->cmsg_len),
1120 		    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1121 			cm = mtod(control, struct cmsghdr *);
1122 			if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1123 			    || cm->cmsg_len > control->m_len) {
1124 				error = EINVAL;
1125 				break;
1126 			}
1127 #ifdef INET6
1128 			error = udp_v4mapped_pktinfo(cm, &src, inp, flags);
1129 			if (error != 0)
1130 				break;
1131 #endif
1132 			if (cm->cmsg_level != IPPROTO_IP)
1133 				continue;
1134 
1135 			switch (cm->cmsg_type) {
1136 			case IP_SENDSRCADDR:
1137 				if (cm->cmsg_len !=
1138 				    CMSG_LEN(sizeof(struct in_addr))) {
1139 					error = EINVAL;
1140 					break;
1141 				}
1142 				bzero(&src, sizeof(src));
1143 				src.sin_family = AF_INET;
1144 				src.sin_len = sizeof(src);
1145 				src.sin_port = inp->inp_lport;
1146 				src.sin_addr =
1147 				    *(struct in_addr *)CMSG_DATA(cm);
1148 				break;
1149 
1150 			case IP_TOS:
1151 				if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1152 					error = EINVAL;
1153 					break;
1154 				}
1155 				tos = *(u_char *)CMSG_DATA(cm);
1156 				break;
1157 
1158 			case IP_FLOWID:
1159 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1160 					error = EINVAL;
1161 					break;
1162 				}
1163 				flowid = *(uint32_t *) CMSG_DATA(cm);
1164 				break;
1165 
1166 			case IP_FLOWTYPE:
1167 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1168 					error = EINVAL;
1169 					break;
1170 				}
1171 				flowtype = *(uint32_t *) CMSG_DATA(cm);
1172 				break;
1173 
1174 #ifdef	RSS
1175 			case IP_RSSBUCKETID:
1176 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1177 					error = EINVAL;
1178 					break;
1179 				}
1180 				/* This is just a placeholder for now */
1181 				break;
1182 #endif	/* RSS */
1183 			default:
1184 				error = ENOPROTOOPT;
1185 				break;
1186 			}
1187 			if (error)
1188 				break;
1189 		}
1190 		m_freem(control);
1191 		control = NULL;
1192 	}
1193 	if (error)
1194 		goto release;
1195 
1196 	pr = inp->inp_socket->so_proto->pr_protocol;
1197 	pcbinfo = udp_get_inpcbinfo(pr);
1198 
1199 	/*
1200 	 * If the IP_SENDSRCADDR control message was specified, override the
1201 	 * source address for this datagram.  Its use is invalidated if the
1202 	 * address thus specified is incomplete or clobbers other inpcbs.
1203 	 */
1204 	laddr = inp->inp_laddr;
1205 	lport = inp->inp_lport;
1206 	if (src.sin_family == AF_INET) {
1207 		if ((lport == 0) ||
1208 		    (laddr.s_addr == INADDR_ANY &&
1209 		     src.sin_addr.s_addr == INADDR_ANY)) {
1210 			error = EINVAL;
1211 			goto release;
1212 		}
1213 		if ((flags & PRUS_IPV6) != 0) {
1214 			vflagsav = inp->inp_vflag;
1215 			inp->inp_vflag |= INP_IPV4;
1216 			inp->inp_vflag &= ~INP_IPV6;
1217 		}
1218 		INP_HASH_WLOCK(pcbinfo);
1219 		error = in_pcbbind_setup(inp, &src, &laddr.s_addr, &lport,
1220 		    td->td_ucred);
1221 		INP_HASH_WUNLOCK(pcbinfo);
1222 		if ((flags & PRUS_IPV6) != 0)
1223 			inp->inp_vflag = vflagsav;
1224 		if (error)
1225 			goto release;
1226 	}
1227 
1228 	/*
1229 	 * If a UDP socket has been connected, then a local address/port will
1230 	 * have been selected and bound.
1231 	 *
1232 	 * If a UDP socket has not been connected to, then an explicit
1233 	 * destination address must be used, in which case a local
1234 	 * address/port may not have been selected and bound.
1235 	 */
1236 	if (sin != NULL) {
1237 		INP_LOCK_ASSERT(inp);
1238 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1239 			error = EISCONN;
1240 			goto release;
1241 		}
1242 
1243 		/*
1244 		 * Jail may rewrite the destination address, so let it do
1245 		 * that before we use it.
1246 		 */
1247 		error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1248 		if (error)
1249 			goto release;
1250 
1251 		/*
1252 		 * If a local address or port hasn't yet been selected, or if
1253 		 * the destination address needs to be rewritten due to using
1254 		 * a special INADDR_ constant, invoke in_pcbconnect_setup()
1255 		 * to do the heavy lifting.  Once a port is selected, we
1256 		 * commit the binding back to the socket; we also commit the
1257 		 * binding of the address if in jail.
1258 		 *
1259 		 * If we already have a valid binding and we're not
1260 		 * requesting a destination address rewrite, use a fast path.
1261 		 */
1262 		if (inp->inp_laddr.s_addr == INADDR_ANY ||
1263 		    inp->inp_lport == 0 ||
1264 		    sin->sin_addr.s_addr == INADDR_ANY ||
1265 		    sin->sin_addr.s_addr == INADDR_BROADCAST) {
1266 			if ((flags & PRUS_IPV6) != 0) {
1267 				vflagsav = inp->inp_vflag;
1268 				inp->inp_vflag |= INP_IPV4;
1269 				inp->inp_vflag &= ~INP_IPV6;
1270 			}
1271 			INP_HASH_WLOCK(pcbinfo);
1272 			error = in_pcbconnect_setup(inp, sin, &laddr.s_addr,
1273 			    &lport, &faddr.s_addr, &fport, td->td_ucred);
1274 			if ((flags & PRUS_IPV6) != 0)
1275 				inp->inp_vflag = vflagsav;
1276 			if (error) {
1277 				INP_HASH_WUNLOCK(pcbinfo);
1278 				goto release;
1279 			}
1280 
1281 			/*
1282 			 * XXXRW: Why not commit the port if the address is
1283 			 * !INADDR_ANY?
1284 			 */
1285 			/* Commit the local port if newly assigned. */
1286 			if (inp->inp_laddr.s_addr == INADDR_ANY &&
1287 			    inp->inp_lport == 0) {
1288 				INP_WLOCK_ASSERT(inp);
1289 				/*
1290 				 * Remember addr if jailed, to prevent
1291 				 * rebinding.
1292 				 */
1293 				if (prison_flag(td->td_ucred, PR_IP4))
1294 					inp->inp_laddr = laddr;
1295 				inp->inp_lport = lport;
1296 				error = in_pcbinshash(inp);
1297 				INP_HASH_WUNLOCK(pcbinfo);
1298 				if (error != 0) {
1299 					inp->inp_lport = 0;
1300 					error = EAGAIN;
1301 					goto release;
1302 				}
1303 				inp->inp_flags |= INP_ANONPORT;
1304 			} else
1305 				INP_HASH_WUNLOCK(pcbinfo);
1306 		} else {
1307 			faddr = sin->sin_addr;
1308 			fport = sin->sin_port;
1309 		}
1310 	} else {
1311 		INP_LOCK_ASSERT(inp);
1312 		faddr = inp->inp_faddr;
1313 		fport = inp->inp_fport;
1314 		if (faddr.s_addr == INADDR_ANY) {
1315 			error = ENOTCONN;
1316 			goto release;
1317 		}
1318 	}
1319 
1320 	/*
1321 	 * Calculate data length and get a mbuf for UDP, IP, and possible
1322 	 * link-layer headers.  Immediate slide the data pointer back forward
1323 	 * since we won't use that space at this layer.
1324 	 */
1325 	M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1326 	if (m == NULL) {
1327 		error = ENOBUFS;
1328 		goto release;
1329 	}
1330 	m->m_data += max_linkhdr;
1331 	m->m_len -= max_linkhdr;
1332 	m->m_pkthdr.len -= max_linkhdr;
1333 
1334 	/*
1335 	 * Fill in mbuf with extended UDP header and addresses and length put
1336 	 * into network format.
1337 	 */
1338 	ui = mtod(m, struct udpiphdr *);
1339 	/*
1340 	 * Filling only those fields of udpiphdr that participate in the
1341 	 * checksum calculation. The rest must be zeroed and will be filled
1342 	 * later.
1343 	 */
1344 	bzero(ui->ui_x1, sizeof(ui->ui_x1));
1345 	ui->ui_pr = pr;
1346 	ui->ui_src = laddr;
1347 	ui->ui_dst = faddr;
1348 	ui->ui_sport = lport;
1349 	ui->ui_dport = fport;
1350 	ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1351 	if (pr == IPPROTO_UDPLITE) {
1352 		struct udpcb *up;
1353 		uint16_t plen;
1354 
1355 		up = intoudpcb(inp);
1356 		cscov = up->u_txcslen;
1357 		plen = (u_short)len + sizeof(struct udphdr);
1358 		if (cscov >= plen)
1359 			cscov = 0;
1360 		ui->ui_len = htons(plen);
1361 		ui->ui_ulen = htons(cscov);
1362 		/*
1363 		 * For UDP-Lite, checksum coverage length of zero means
1364 		 * the entire UDPLite packet is covered by the checksum.
1365 		 */
1366 		cscov_partial = (cscov == 0) ? 0 : 1;
1367 	}
1368 
1369 	if (inp->inp_socket->so_options & SO_DONTROUTE)
1370 		ipflags |= IP_ROUTETOIF;
1371 	if (inp->inp_socket->so_options & SO_BROADCAST)
1372 		ipflags |= IP_ALLOWBROADCAST;
1373 	if (inp->inp_flags & INP_ONESBCAST)
1374 		ipflags |= IP_SENDONES;
1375 
1376 #ifdef MAC
1377 	mac_inpcb_create_mbuf(inp, m);
1378 #endif
1379 
1380 	/*
1381 	 * Set up checksum and output datagram.
1382 	 */
1383 	ui->ui_sum = 0;
1384 	if (pr == IPPROTO_UDPLITE) {
1385 		if (inp->inp_flags & INP_ONESBCAST)
1386 			faddr.s_addr = INADDR_BROADCAST;
1387 		if (cscov_partial) {
1388 			if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
1389 				ui->ui_sum = 0xffff;
1390 		} else {
1391 			if ((ui->ui_sum = in_cksum(m, sizeof(struct udpiphdr) + len)) == 0)
1392 				ui->ui_sum = 0xffff;
1393 		}
1394 	} else if (V_udp_cksum) {
1395 		if (inp->inp_flags & INP_ONESBCAST)
1396 			faddr.s_addr = INADDR_BROADCAST;
1397 		ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1398 		    htons((u_short)len + sizeof(struct udphdr) + pr));
1399 		m->m_pkthdr.csum_flags = CSUM_UDP;
1400 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1401 	}
1402 	/*
1403 	 * After finishing the checksum computation, fill the remaining fields
1404 	 * of udpiphdr.
1405 	 */
1406 	((struct ip *)ui)->ip_v = IPVERSION;
1407 	((struct ip *)ui)->ip_tos = tos;
1408 	((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1409 	if (inp->inp_flags & INP_DONTFRAG)
1410 		((struct ip *)ui)->ip_off |= htons(IP_DF);
1411 	((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;
1412 	UDPSTAT_INC(udps_opackets);
1413 
1414 	/*
1415 	 * Setup flowid / RSS information for outbound socket.
1416 	 *
1417 	 * Once the UDP code decides to set a flowid some other way,
1418 	 * this allows the flowid to be overridden by userland.
1419 	 */
1420 	if (flowtype != M_HASHTYPE_NONE) {
1421 		m->m_pkthdr.flowid = flowid;
1422 		M_HASHTYPE_SET(m, flowtype);
1423 	}
1424 #if defined(ROUTE_MPATH) || defined(RSS)
1425 	else if (CALC_FLOWID_OUTBOUND_SENDTO) {
1426 		uint32_t hash_val, hash_type;
1427 
1428 		hash_val = fib4_calc_packet_hash(laddr, faddr,
1429 		    lport, fport, pr, &hash_type);
1430 		m->m_pkthdr.flowid = hash_val;
1431 		M_HASHTYPE_SET(m, hash_type);
1432 	}
1433 
1434 	/*
1435 	 * Don't override with the inp cached flowid value.
1436 	 *
1437 	 * Depending upon the kind of send being done, the inp
1438 	 * flowid/flowtype values may actually not be appropriate
1439 	 * for this particular socket send.
1440 	 *
1441 	 * We should either leave the flowid at zero (which is what is
1442 	 * currently done) or set it to some software generated
1443 	 * hash value based on the packet contents.
1444 	 */
1445 	ipflags |= IP_NODEFAULTFLOWID;
1446 #endif	/* RSS */
1447 
1448 	if (pr == IPPROTO_UDPLITE)
1449 		UDPLITE_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1450 	else
1451 		UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1452 	error = ip_output(m, inp->inp_options,
1453 	    INP_WLOCKED(inp) ? &inp->inp_route : NULL, ipflags,
1454 	    inp->inp_moptions, inp);
1455 	INP_UNLOCK(inp);
1456 	NET_EPOCH_EXIT(et);
1457 	return (error);
1458 
1459 release:
1460 	INP_UNLOCK(inp);
1461 	NET_EPOCH_EXIT(et);
1462 	m_freem(m);
1463 	return (error);
1464 }
1465 
1466 void
1467 udp_abort(struct socket *so)
1468 {
1469 	struct inpcb *inp;
1470 	struct inpcbinfo *pcbinfo;
1471 
1472 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1473 	inp = sotoinpcb(so);
1474 	KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1475 	INP_WLOCK(inp);
1476 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1477 		INP_HASH_WLOCK(pcbinfo);
1478 		in_pcbdisconnect(inp);
1479 		INP_HASH_WUNLOCK(pcbinfo);
1480 		soisdisconnected(so);
1481 	}
1482 	INP_WUNLOCK(inp);
1483 }
1484 
1485 static int
1486 udp_attach(struct socket *so, int proto, struct thread *td)
1487 {
1488 	static uint32_t udp_flowid;
1489 	struct inpcbinfo *pcbinfo;
1490 	struct inpcb *inp;
1491 	struct udpcb *up;
1492 	int error;
1493 
1494 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1495 	inp = sotoinpcb(so);
1496 	KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1497 	error = soreserve(so, udp_sendspace, udp_recvspace);
1498 	if (error)
1499 		return (error);
1500 	error = in_pcballoc(so, pcbinfo);
1501 	if (error)
1502 		return (error);
1503 
1504 	inp = sotoinpcb(so);
1505 	inp->inp_ip_ttl = V_ip_defttl;
1506 	inp->inp_flowid = atomic_fetchadd_int(&udp_flowid, 1);
1507 	inp->inp_flowtype = M_HASHTYPE_OPAQUE;
1508 	up = intoudpcb(inp);
1509 	bzero(&up->u_start_zero, u_zero_size);
1510 	INP_WUNLOCK(inp);
1511 
1512 	return (0);
1513 }
1514 #endif /* INET */
1515 
1516 int
1517 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f, udp_tun_icmp_t i, void *ctx)
1518 {
1519 	struct inpcb *inp;
1520 	struct udpcb *up;
1521 
1522 	KASSERT(so->so_type == SOCK_DGRAM,
1523 	    ("udp_set_kernel_tunneling: !dgram"));
1524 	inp = sotoinpcb(so);
1525 	KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1526 	INP_WLOCK(inp);
1527 	up = intoudpcb(inp);
1528 	if ((f != NULL || i != NULL) && ((up->u_tun_func != NULL) ||
1529 	    (up->u_icmp_func != NULL))) {
1530 		INP_WUNLOCK(inp);
1531 		return (EBUSY);
1532 	}
1533 	up->u_tun_func = f;
1534 	up->u_icmp_func = i;
1535 	up->u_tun_ctx = ctx;
1536 	INP_WUNLOCK(inp);
1537 	return (0);
1538 }
1539 
1540 #ifdef INET
1541 static int
1542 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1543 {
1544 	struct inpcb *inp;
1545 	struct inpcbinfo *pcbinfo;
1546 	struct sockaddr_in *sinp;
1547 	int error;
1548 
1549 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1550 	inp = sotoinpcb(so);
1551 	KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1552 
1553 	sinp = (struct sockaddr_in *)nam;
1554 	if (nam->sa_family != AF_INET) {
1555 		/*
1556 		 * Preserve compatibility with old programs.
1557 		 */
1558 		if (nam->sa_family != AF_UNSPEC ||
1559 		    nam->sa_len < offsetof(struct sockaddr_in, sin_zero) ||
1560 		    sinp->sin_addr.s_addr != INADDR_ANY)
1561 			return (EAFNOSUPPORT);
1562 		nam->sa_family = AF_INET;
1563 	}
1564 	if (nam->sa_len != sizeof(struct sockaddr_in))
1565 		return (EINVAL);
1566 
1567 	INP_WLOCK(inp);
1568 	INP_HASH_WLOCK(pcbinfo);
1569 	error = in_pcbbind(inp, sinp, td->td_ucred);
1570 	INP_HASH_WUNLOCK(pcbinfo);
1571 	INP_WUNLOCK(inp);
1572 	return (error);
1573 }
1574 
1575 static void
1576 udp_close(struct socket *so)
1577 {
1578 	struct inpcb *inp;
1579 	struct inpcbinfo *pcbinfo;
1580 
1581 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1582 	inp = sotoinpcb(so);
1583 	KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1584 	INP_WLOCK(inp);
1585 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1586 		INP_HASH_WLOCK(pcbinfo);
1587 		in_pcbdisconnect(inp);
1588 		INP_HASH_WUNLOCK(pcbinfo);
1589 		soisdisconnected(so);
1590 	}
1591 	INP_WUNLOCK(inp);
1592 }
1593 
1594 static int
1595 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1596 {
1597 	struct epoch_tracker et;
1598 	struct inpcb *inp;
1599 	struct inpcbinfo *pcbinfo;
1600 	struct sockaddr_in *sin;
1601 	int error;
1602 
1603 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1604 	inp = sotoinpcb(so);
1605 	KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1606 
1607 	sin = (struct sockaddr_in *)nam;
1608 	if (sin->sin_family != AF_INET)
1609 		return (EAFNOSUPPORT);
1610 	if (sin->sin_len != sizeof(*sin))
1611 		return (EINVAL);
1612 
1613 	INP_WLOCK(inp);
1614 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1615 		INP_WUNLOCK(inp);
1616 		return (EISCONN);
1617 	}
1618 	error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1619 	if (error != 0) {
1620 		INP_WUNLOCK(inp);
1621 		return (error);
1622 	}
1623 	NET_EPOCH_ENTER(et);
1624 	INP_HASH_WLOCK(pcbinfo);
1625 	error = in_pcbconnect(inp, sin, td->td_ucred, true);
1626 	INP_HASH_WUNLOCK(pcbinfo);
1627 	NET_EPOCH_EXIT(et);
1628 	if (error == 0)
1629 		soisconnected(so);
1630 	INP_WUNLOCK(inp);
1631 	return (error);
1632 }
1633 
1634 static void
1635 udp_detach(struct socket *so)
1636 {
1637 	struct inpcb *inp;
1638 
1639 	inp = sotoinpcb(so);
1640 	KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1641 	KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1642 	    ("udp_detach: not disconnected"));
1643 	INP_WLOCK(inp);
1644 	in_pcbdetach(inp);
1645 	in_pcbfree(inp);
1646 }
1647 
1648 int
1649 udp_disconnect(struct socket *so)
1650 {
1651 	struct inpcb *inp;
1652 	struct inpcbinfo *pcbinfo;
1653 
1654 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1655 	inp = sotoinpcb(so);
1656 	KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1657 	INP_WLOCK(inp);
1658 	if (inp->inp_faddr.s_addr == INADDR_ANY) {
1659 		INP_WUNLOCK(inp);
1660 		return (ENOTCONN);
1661 	}
1662 	INP_HASH_WLOCK(pcbinfo);
1663 	in_pcbdisconnect(inp);
1664 	INP_HASH_WUNLOCK(pcbinfo);
1665 	SOCK_LOCK(so);
1666 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1667 	SOCK_UNLOCK(so);
1668 	INP_WUNLOCK(inp);
1669 	return (0);
1670 }
1671 #endif /* INET */
1672 
1673 int
1674 udp_shutdown(struct socket *so)
1675 {
1676 	struct inpcb *inp;
1677 
1678 	inp = sotoinpcb(so);
1679 	KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1680 	INP_WLOCK(inp);
1681 	socantsendmore(so);
1682 	INP_WUNLOCK(inp);
1683 	return (0);
1684 }
1685 
1686 #ifdef INET
1687 #define	UDP_PROTOSW							\
1688 	.pr_type =		SOCK_DGRAM,				\
1689 	.pr_flags =		PR_ATOMIC | PR_ADDR | PR_CAPATTACH,	\
1690 	.pr_ctloutput =		udp_ctloutput,				\
1691 	.pr_abort =		udp_abort,				\
1692 	.pr_attach =		udp_attach,				\
1693 	.pr_bind =		udp_bind,				\
1694 	.pr_connect =		udp_connect,				\
1695 	.pr_control =		in_control,				\
1696 	.pr_detach =		udp_detach,				\
1697 	.pr_disconnect =	udp_disconnect,				\
1698 	.pr_peeraddr =		in_getpeeraddr,				\
1699 	.pr_send =		udp_send,				\
1700 	.pr_soreceive =		soreceive_dgram,			\
1701 	.pr_sosend =		sosend_dgram,				\
1702 	.pr_shutdown =		udp_shutdown,				\
1703 	.pr_sockaddr =		in_getsockaddr,				\
1704 	.pr_sosetlabel =	in_pcbsosetlabel,			\
1705 	.pr_close =		udp_close
1706 
1707 struct protosw udp_protosw = {
1708 	.pr_protocol =		IPPROTO_UDP,
1709 	UDP_PROTOSW
1710 };
1711 
1712 struct protosw udplite_protosw = {
1713 	.pr_protocol =		IPPROTO_UDPLITE,
1714 	UDP_PROTOSW
1715 };
1716 
1717 static void
1718 udp_init(void *arg __unused)
1719 {
1720 
1721 	IPPROTO_REGISTER(IPPROTO_UDP, udp_input, udp_ctlinput);
1722 	IPPROTO_REGISTER(IPPROTO_UDPLITE, udp_input, udplite_ctlinput);
1723 }
1724 SYSINIT(udp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, udp_init, NULL);
1725 #endif /* INET */
1726