xref: /freebsd/sys/netinet/udp_usrreq.c (revision b13788e396c2b24f88697e7d4a74bab429ef4d0c)
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  *	@(#)udp_usrreq.c	8.6 (Berkeley) 5/23/95
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include "opt_inet.h"
45 #include "opt_inet6.h"
46 #include "opt_ipsec.h"
47 #include "opt_rss.h"
48 
49 #include <sys/param.h>
50 #include <sys/domain.h>
51 #include <sys/eventhandler.h>
52 #include <sys/jail.h>
53 #include <sys/kernel.h>
54 #include <sys/lock.h>
55 #include <sys/malloc.h>
56 #include <sys/mbuf.h>
57 #include <sys/priv.h>
58 #include <sys/proc.h>
59 #include <sys/protosw.h>
60 #include <sys/sdt.h>
61 #include <sys/signalvar.h>
62 #include <sys/socket.h>
63 #include <sys/socketvar.h>
64 #include <sys/sx.h>
65 #include <sys/sysctl.h>
66 #include <sys/syslog.h>
67 #include <sys/systm.h>
68 
69 #include <vm/uma.h>
70 
71 #include <net/if.h>
72 #include <net/if_var.h>
73 #include <net/route.h>
74 #include <net/route/nhop.h>
75 #include <net/rss_config.h>
76 
77 #include <netinet/in.h>
78 #include <netinet/in_kdtrace.h>
79 #include <netinet/in_pcb.h>
80 #include <netinet/in_systm.h>
81 #include <netinet/in_var.h>
82 #include <netinet/ip.h>
83 #ifdef INET6
84 #include <netinet/ip6.h>
85 #endif
86 #include <netinet/ip_icmp.h>
87 #include <netinet/icmp_var.h>
88 #include <netinet/ip_var.h>
89 #include <netinet/ip_options.h>
90 #ifdef INET6
91 #include <netinet6/ip6_var.h>
92 #endif
93 #include <netinet/udp.h>
94 #include <netinet/udp_var.h>
95 #include <netinet/udplite.h>
96 #include <netinet/in_rss.h>
97 
98 #include <netipsec/ipsec_support.h>
99 
100 #include <machine/in_cksum.h>
101 
102 #include <security/mac/mac_framework.h>
103 
104 /*
105  * UDP and UDP-Lite protocols implementation.
106  * Per RFC 768, August, 1980.
107  * Per RFC 3828, July, 2004.
108  */
109 
110 /*
111  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
112  * removes the only data integrity mechanism for packets and malformed
113  * packets that would otherwise be discarded due to bad checksums, and may
114  * cause problems (especially for NFS data blocks).
115  */
116 VNET_DEFINE(int, udp_cksum) = 1;
117 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_VNET | CTLFLAG_RW,
118     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
119 
120 VNET_DEFINE(int, udp_log_in_vain) = 0;
121 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_VNET | CTLFLAG_RW,
122     &VNET_NAME(udp_log_in_vain), 0, "Log all incoming UDP packets");
123 
124 VNET_DEFINE(int, udp_blackhole) = 0;
125 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_VNET | CTLFLAG_RW,
126     &VNET_NAME(udp_blackhole), 0,
127     "Do not send port unreachables for refused connects");
128 
129 u_long	udp_sendspace = 9216;		/* really max datagram size */
130 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
131     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
132 
133 u_long	udp_recvspace = 40 * (1024 +
134 #ifdef INET6
135 				      sizeof(struct sockaddr_in6)
136 #else
137 				      sizeof(struct sockaddr_in)
138 #endif
139 				      );	/* 40 1K datagrams */
140 
141 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
142     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
143 
144 VNET_DEFINE(struct inpcbhead, udb);		/* from udp_var.h */
145 VNET_DEFINE(struct inpcbinfo, udbinfo);
146 VNET_DEFINE(struct inpcbhead, ulitecb);
147 VNET_DEFINE(struct inpcbinfo, ulitecbinfo);
148 VNET_DEFINE_STATIC(uma_zone_t, udpcb_zone);
149 #define	V_udpcb_zone			VNET(udpcb_zone)
150 
151 #ifndef UDBHASHSIZE
152 #define	UDBHASHSIZE	128
153 #endif
154 
155 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);		/* from udp_var.h */
156 VNET_PCPUSTAT_SYSINIT(udpstat);
157 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
158     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
159 
160 #ifdef VIMAGE
161 VNET_PCPUSTAT_SYSUNINIT(udpstat);
162 #endif /* VIMAGE */
163 #ifdef INET
164 static void	udp_detach(struct socket *so);
165 static int	udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
166 		    struct mbuf *, struct thread *);
167 #endif
168 
169 static void
170 udp_zone_change(void *tag)
171 {
172 
173 	uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
174 	uma_zone_set_max(V_udpcb_zone, maxsockets);
175 }
176 
177 static int
178 udp_inpcb_init(void *mem, int size, int flags)
179 {
180 	struct inpcb *inp;
181 
182 	inp = mem;
183 	INP_LOCK_INIT(inp, "inp", "udpinp");
184 	return (0);
185 }
186 
187 static int
188 udplite_inpcb_init(void *mem, int size, int flags)
189 {
190 	struct inpcb *inp;
191 
192 	inp = mem;
193 	INP_LOCK_INIT(inp, "inp", "udpliteinp");
194 	return (0);
195 }
196 
197 void
198 udp_init(void)
199 {
200 
201 	/*
202 	 * For now default to 2-tuple UDP hashing - until the fragment
203 	 * reassembly code can also update the flowid.
204 	 *
205 	 * Once we can calculate the flowid that way and re-establish
206 	 * a 4-tuple, flip this to 4-tuple.
207 	 */
208 	in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
209 	    "udp_inpcb", udp_inpcb_init, IPI_HASHFIELDS_2TUPLE);
210 	V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
211 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
212 	uma_zone_set_max(V_udpcb_zone, maxsockets);
213 	uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
214 	EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
215 	    EVENTHANDLER_PRI_ANY);
216 }
217 
218 void
219 udplite_init(void)
220 {
221 
222 	in_pcbinfo_init(&V_ulitecbinfo, "udplite", &V_ulitecb, UDBHASHSIZE,
223 	    UDBHASHSIZE, "udplite_inpcb", udplite_inpcb_init,
224 	    IPI_HASHFIELDS_2TUPLE);
225 }
226 
227 /*
228  * Kernel module interface for updating udpstat.  The argument is an index
229  * into udpstat treated as an array of u_long.  While this encodes the
230  * general layout of udpstat into the caller, it doesn't encode its location,
231  * so that future changes to add, for example, per-CPU stats support won't
232  * cause binary compatibility problems for kernel modules.
233  */
234 void
235 kmod_udpstat_inc(int statnum)
236 {
237 
238 	counter_u64_add(VNET(udpstat)[statnum], 1);
239 }
240 
241 int
242 udp_newudpcb(struct inpcb *inp)
243 {
244 	struct udpcb *up;
245 
246 	up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
247 	if (up == NULL)
248 		return (ENOBUFS);
249 	inp->inp_ppcb = up;
250 	return (0);
251 }
252 
253 void
254 udp_discardcb(struct udpcb *up)
255 {
256 
257 	uma_zfree(V_udpcb_zone, up);
258 }
259 
260 #ifdef VIMAGE
261 static void
262 udp_destroy(void *unused __unused)
263 {
264 
265 	in_pcbinfo_destroy(&V_udbinfo);
266 	uma_zdestroy(V_udpcb_zone);
267 }
268 VNET_SYSUNINIT(udp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udp_destroy, NULL);
269 
270 static void
271 udplite_destroy(void *unused __unused)
272 {
273 
274 	in_pcbinfo_destroy(&V_ulitecbinfo);
275 }
276 VNET_SYSUNINIT(udplite, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udplite_destroy,
277     NULL);
278 #endif
279 
280 #ifdef INET
281 /*
282  * Subroutine of udp_input(), which appends the provided mbuf chain to the
283  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
284  * contains the source address.  If the socket ends up being an IPv6 socket,
285  * udp_append() will convert to a sockaddr_in6 before passing the address
286  * into the socket code.
287  *
288  * In the normal case udp_append() will return 0, indicating that you
289  * must unlock the inp. However if a tunneling protocol is in place we increment
290  * the inpcb refcnt and unlock the inp, on return from the tunneling protocol we
291  * then decrement the reference count. If the inp_rele returns 1, indicating the
292  * inp is gone, we return that to the caller to tell them *not* to unlock
293  * the inp. In the case of multi-cast this will cause the distribution
294  * to stop (though most tunneling protocols known currently do *not* use
295  * multicast).
296  */
297 static int
298 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
299     struct sockaddr_in *udp_in)
300 {
301 	struct sockaddr *append_sa;
302 	struct socket *so;
303 	struct mbuf *tmpopts, *opts = NULL;
304 #ifdef INET6
305 	struct sockaddr_in6 udp_in6;
306 #endif
307 	struct udpcb *up;
308 
309 	INP_LOCK_ASSERT(inp);
310 
311 	/*
312 	 * Engage the tunneling protocol.
313 	 */
314 	up = intoudpcb(inp);
315 	if (up->u_tun_func != NULL) {
316 		in_pcbref(inp);
317 		INP_RUNLOCK(inp);
318 		(*up->u_tun_func)(n, off, inp, (struct sockaddr *)&udp_in[0],
319 		    up->u_tun_ctx);
320 		INP_RLOCK(inp);
321 		return (in_pcbrele_rlocked(inp));
322 	}
323 
324 	off += sizeof(struct udphdr);
325 
326 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
327 	/* Check AH/ESP integrity. */
328 	if (IPSEC_ENABLED(ipv4) &&
329 	    IPSEC_CHECK_POLICY(ipv4, n, inp) != 0) {
330 		m_freem(n);
331 		return (0);
332 	}
333 	if (up->u_flags & UF_ESPINUDP) {/* IPSec UDP encaps. */
334 		if (IPSEC_ENABLED(ipv4) &&
335 		    UDPENCAP_INPUT(n, off, AF_INET) != 0)
336 			return (0);	/* Consumed. */
337 	}
338 #endif /* IPSEC */
339 #ifdef MAC
340 	if (mac_inpcb_check_deliver(inp, n) != 0) {
341 		m_freem(n);
342 		return (0);
343 	}
344 #endif /* MAC */
345 	if (inp->inp_flags & INP_CONTROLOPTS ||
346 	    inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
347 #ifdef INET6
348 		if (inp->inp_vflag & INP_IPV6)
349 			(void)ip6_savecontrol_v4(inp, n, &opts, NULL);
350 		else
351 #endif /* INET6 */
352 			ip_savecontrol(inp, &opts, ip, n);
353 	}
354 	if ((inp->inp_vflag & INP_IPV4) && (inp->inp_flags2 & INP_ORIGDSTADDR)) {
355 		tmpopts = sbcreatecontrol((caddr_t)&udp_in[1],
356 			sizeof(struct sockaddr_in), IP_ORIGDSTADDR, IPPROTO_IP);
357 		if (tmpopts) {
358 			if (opts) {
359 				tmpopts->m_next = opts;
360 				opts = tmpopts;
361 			} else
362 				opts = tmpopts;
363 		}
364 	}
365 #ifdef INET6
366 	if (inp->inp_vflag & INP_IPV6) {
367 		bzero(&udp_in6, sizeof(udp_in6));
368 		udp_in6.sin6_len = sizeof(udp_in6);
369 		udp_in6.sin6_family = AF_INET6;
370 		in6_sin_2_v4mapsin6(&udp_in[0], &udp_in6);
371 		append_sa = (struct sockaddr *)&udp_in6;
372 	} else
373 #endif /* INET6 */
374 		append_sa = (struct sockaddr *)&udp_in[0];
375 	m_adj(n, off);
376 
377 	so = inp->inp_socket;
378 	SOCKBUF_LOCK(&so->so_rcv);
379 	if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
380 		SOCKBUF_UNLOCK(&so->so_rcv);
381 		m_freem(n);
382 		if (opts)
383 			m_freem(opts);
384 		UDPSTAT_INC(udps_fullsock);
385 	} else
386 		sorwakeup_locked(so);
387 	return (0);
388 }
389 
390 int
391 udp_input(struct mbuf **mp, int *offp, int proto)
392 {
393 	struct ip *ip;
394 	struct udphdr *uh;
395 	struct ifnet *ifp;
396 	struct inpcb *inp;
397 	uint16_t len, ip_len;
398 	struct inpcbinfo *pcbinfo;
399 	struct ip save_ip;
400 	struct sockaddr_in udp_in[2];
401 	struct mbuf *m;
402 	struct m_tag *fwd_tag;
403 	int cscov_partial, iphlen;
404 
405 	m = *mp;
406 	iphlen = *offp;
407 	ifp = m->m_pkthdr.rcvif;
408 	*mp = NULL;
409 	UDPSTAT_INC(udps_ipackets);
410 
411 	/*
412 	 * Strip IP options, if any; should skip this, make available to
413 	 * user, and use on returned packets, but we don't yet have a way to
414 	 * check the checksum with options still present.
415 	 */
416 	if (iphlen > sizeof (struct ip)) {
417 		ip_stripoptions(m);
418 		iphlen = sizeof(struct ip);
419 	}
420 
421 	/*
422 	 * Get IP and UDP header together in first mbuf.
423 	 */
424 	if (m->m_len < iphlen + sizeof(struct udphdr)) {
425 		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) {
426 			UDPSTAT_INC(udps_hdrops);
427 			return (IPPROTO_DONE);
428 		}
429 	}
430 	ip = mtod(m, struct ip *);
431 	uh = (struct udphdr *)((caddr_t)ip + iphlen);
432 	cscov_partial = (proto == IPPROTO_UDPLITE) ? 1 : 0;
433 
434 	/*
435 	 * Destination port of 0 is illegal, based on RFC768.
436 	 */
437 	if (uh->uh_dport == 0)
438 		goto badunlocked;
439 
440 	/*
441 	 * Construct sockaddr format source address.  Stuff source address
442 	 * and datagram in user buffer.
443 	 */
444 	bzero(&udp_in[0], sizeof(struct sockaddr_in) * 2);
445 	udp_in[0].sin_len = sizeof(struct sockaddr_in);
446 	udp_in[0].sin_family = AF_INET;
447 	udp_in[0].sin_port = uh->uh_sport;
448 	udp_in[0].sin_addr = ip->ip_src;
449 	udp_in[1].sin_len = sizeof(struct sockaddr_in);
450 	udp_in[1].sin_family = AF_INET;
451 	udp_in[1].sin_port = uh->uh_dport;
452 	udp_in[1].sin_addr = ip->ip_dst;
453 
454 	/*
455 	 * Make mbuf data length reflect UDP length.  If not enough data to
456 	 * reflect UDP length, drop.
457 	 */
458 	len = ntohs((u_short)uh->uh_ulen);
459 	ip_len = ntohs(ip->ip_len) - iphlen;
460 	if (proto == IPPROTO_UDPLITE && (len == 0 || len == ip_len)) {
461 		/* Zero means checksum over the complete packet. */
462 		if (len == 0)
463 			len = ip_len;
464 		cscov_partial = 0;
465 	}
466 	if (ip_len != len) {
467 		if (len > ip_len || len < sizeof(struct udphdr)) {
468 			UDPSTAT_INC(udps_badlen);
469 			goto badunlocked;
470 		}
471 		if (proto == IPPROTO_UDP)
472 			m_adj(m, len - ip_len);
473 	}
474 
475 	/*
476 	 * Save a copy of the IP header in case we want restore it for
477 	 * sending an ICMP error message in response.
478 	 */
479 	if (!V_udp_blackhole)
480 		save_ip = *ip;
481 	else
482 		memset(&save_ip, 0, sizeof(save_ip));
483 
484 	/*
485 	 * Checksum extended UDP header and data.
486 	 */
487 	if (uh->uh_sum) {
488 		u_short uh_sum;
489 
490 		if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
491 		    !cscov_partial) {
492 			if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
493 				uh_sum = m->m_pkthdr.csum_data;
494 			else
495 				uh_sum = in_pseudo(ip->ip_src.s_addr,
496 				    ip->ip_dst.s_addr, htonl((u_short)len +
497 				    m->m_pkthdr.csum_data + proto));
498 			uh_sum ^= 0xffff;
499 		} else {
500 			char b[9];
501 
502 			bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
503 			bzero(((struct ipovly *)ip)->ih_x1, 9);
504 			((struct ipovly *)ip)->ih_len = (proto == IPPROTO_UDP) ?
505 			    uh->uh_ulen : htons(ip_len);
506 			uh_sum = in_cksum(m, len + sizeof (struct ip));
507 			bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
508 		}
509 		if (uh_sum) {
510 			UDPSTAT_INC(udps_badsum);
511 			m_freem(m);
512 			return (IPPROTO_DONE);
513 		}
514 	} else {
515 		if (proto == IPPROTO_UDP) {
516 			UDPSTAT_INC(udps_nosum);
517 		} else {
518 			/* UDPLite requires a checksum */
519 			/* XXX: What is the right UDPLite MIB counter here? */
520 			m_freem(m);
521 			return (IPPROTO_DONE);
522 		}
523 	}
524 
525 	pcbinfo = udp_get_inpcbinfo(proto);
526 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
527 	    in_broadcast(ip->ip_dst, ifp)) {
528 		struct inpcb *last;
529 		struct inpcbhead *pcblist;
530 
531 		NET_EPOCH_ASSERT();
532 
533 		pcblist = udp_get_pcblist(proto);
534 		last = NULL;
535 		CK_LIST_FOREACH(inp, pcblist, inp_list) {
536 			if (inp->inp_lport != uh->uh_dport)
537 				continue;
538 #ifdef INET6
539 			if ((inp->inp_vflag & INP_IPV4) == 0)
540 				continue;
541 #endif
542 			if (inp->inp_laddr.s_addr != INADDR_ANY &&
543 			    inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
544 				continue;
545 			if (inp->inp_faddr.s_addr != INADDR_ANY &&
546 			    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
547 				continue;
548 			if (inp->inp_fport != 0 &&
549 			    inp->inp_fport != uh->uh_sport)
550 				continue;
551 
552 			INP_RLOCK(inp);
553 
554 			if (__predict_false(inp->inp_flags2 & INP_FREED)) {
555 				INP_RUNLOCK(inp);
556 				continue;
557 			}
558 
559 			/*
560 			 * XXXRW: Because we weren't holding either the inpcb
561 			 * or the hash lock when we checked for a match
562 			 * before, we should probably recheck now that the
563 			 * inpcb lock is held.
564 			 */
565 
566 			/*
567 			 * Handle socket delivery policy for any-source
568 			 * and source-specific multicast. [RFC3678]
569 			 */
570 			if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
571 				struct ip_moptions	*imo;
572 				struct sockaddr_in	 group;
573 				int			 blocked;
574 
575 				imo = inp->inp_moptions;
576 				if (imo == NULL) {
577 					INP_RUNLOCK(inp);
578 					continue;
579 				}
580 				bzero(&group, sizeof(struct sockaddr_in));
581 				group.sin_len = sizeof(struct sockaddr_in);
582 				group.sin_family = AF_INET;
583 				group.sin_addr = ip->ip_dst;
584 
585 				blocked = imo_multi_filter(imo, ifp,
586 					(struct sockaddr *)&group,
587 					(struct sockaddr *)&udp_in[0]);
588 				if (blocked != MCAST_PASS) {
589 					if (blocked == MCAST_NOTGMEMBER)
590 						IPSTAT_INC(ips_notmember);
591 					if (blocked == MCAST_NOTSMEMBER ||
592 					    blocked == MCAST_MUTED)
593 						UDPSTAT_INC(udps_filtermcast);
594 					INP_RUNLOCK(inp);
595 					continue;
596 				}
597 			}
598 			if (last != NULL) {
599 				struct mbuf *n;
600 
601 				if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) !=
602 				    NULL) {
603 					if (proto == IPPROTO_UDPLITE)
604 						UDPLITE_PROBE(receive, NULL, last, ip,
605 						    last, uh);
606 					else
607 						UDP_PROBE(receive, NULL, last, ip, last,
608 						    uh);
609 					if (udp_append(last, ip, n, iphlen,
610 						udp_in)) {
611 						goto inp_lost;
612 					}
613 				}
614 				INP_RUNLOCK(last);
615 			}
616 			last = inp;
617 			/*
618 			 * Don't look for additional matches if this one does
619 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
620 			 * socket options set.  This heuristic avoids
621 			 * searching through all pcbs in the common case of a
622 			 * non-shared port.  It assumes that an application
623 			 * will never clear these options after setting them.
624 			 */
625 			if ((last->inp_socket->so_options &
626 			    (SO_REUSEPORT|SO_REUSEPORT_LB|SO_REUSEADDR)) == 0)
627 				break;
628 		}
629 
630 		if (last == NULL) {
631 			/*
632 			 * No matching pcb found; discard datagram.  (No need
633 			 * to send an ICMP Port Unreachable for a broadcast
634 			 * or multicast datgram.)
635 			 */
636 			UDPSTAT_INC(udps_noportbcast);
637 			if (inp)
638 				INP_RUNLOCK(inp);
639 			goto badunlocked;
640 		}
641 		if (proto == IPPROTO_UDPLITE)
642 			UDPLITE_PROBE(receive, NULL, last, ip, last, uh);
643 		else
644 			UDP_PROBE(receive, NULL, last, ip, last, uh);
645 		if (udp_append(last, ip, m, iphlen, udp_in) == 0)
646 			INP_RUNLOCK(last);
647 	inp_lost:
648 		return (IPPROTO_DONE);
649 	}
650 
651 	/*
652 	 * Locate pcb for datagram.
653 	 */
654 
655 	/*
656 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
657 	 */
658 	if ((m->m_flags & M_IP_NEXTHOP) &&
659 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
660 		struct sockaddr_in *next_hop;
661 
662 		next_hop = (struct sockaddr_in *)(fwd_tag + 1);
663 
664 		/*
665 		 * Transparently forwarded. Pretend to be the destination.
666 		 * Already got one like this?
667 		 */
668 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
669 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
670 		if (!inp) {
671 			/*
672 			 * It's new.  Try to find the ambushing socket.
673 			 * Because we've rewritten the destination address,
674 			 * any hardware-generated hash is ignored.
675 			 */
676 			inp = in_pcblookup(pcbinfo, ip->ip_src,
677 			    uh->uh_sport, next_hop->sin_addr,
678 			    next_hop->sin_port ? htons(next_hop->sin_port) :
679 			    uh->uh_dport, INPLOOKUP_WILDCARD |
680 			    INPLOOKUP_RLOCKPCB, ifp);
681 		}
682 		/* Remove the tag from the packet. We don't need it anymore. */
683 		m_tag_delete(m, fwd_tag);
684 		m->m_flags &= ~M_IP_NEXTHOP;
685 	} else
686 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
687 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
688 		    INPLOOKUP_RLOCKPCB, ifp, m);
689 	if (inp == NULL) {
690 		if (V_udp_log_in_vain) {
691 			char src[INET_ADDRSTRLEN];
692 			char dst[INET_ADDRSTRLEN];
693 
694 			log(LOG_INFO,
695 			    "Connection attempt to UDP %s:%d from %s:%d\n",
696 			    inet_ntoa_r(ip->ip_dst, dst), ntohs(uh->uh_dport),
697 			    inet_ntoa_r(ip->ip_src, src), ntohs(uh->uh_sport));
698 		}
699 		if (proto == IPPROTO_UDPLITE)
700 			UDPLITE_PROBE(receive, NULL, NULL, ip, NULL, uh);
701 		else
702 			UDP_PROBE(receive, NULL, NULL, ip, NULL, uh);
703 		UDPSTAT_INC(udps_noport);
704 		if (m->m_flags & (M_BCAST | M_MCAST)) {
705 			UDPSTAT_INC(udps_noportbcast);
706 			goto badunlocked;
707 		}
708 		if (V_udp_blackhole)
709 			goto badunlocked;
710 		if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
711 			goto badunlocked;
712 		*ip = save_ip;
713 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
714 		return (IPPROTO_DONE);
715 	}
716 
717 	/*
718 	 * Check the minimum TTL for socket.
719 	 */
720 	INP_RLOCK_ASSERT(inp);
721 	if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
722 		if (proto == IPPROTO_UDPLITE)
723 			UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
724 		else
725 			UDP_PROBE(receive, NULL, inp, ip, inp, uh);
726 		INP_RUNLOCK(inp);
727 		m_freem(m);
728 		return (IPPROTO_DONE);
729 	}
730 	if (cscov_partial) {
731 		struct udpcb *up;
732 
733 		up = intoudpcb(inp);
734 		if (up->u_rxcslen == 0 || up->u_rxcslen > len) {
735 			INP_RUNLOCK(inp);
736 			m_freem(m);
737 			return (IPPROTO_DONE);
738 		}
739 	}
740 
741 	if (proto == IPPROTO_UDPLITE)
742 		UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
743 	else
744 		UDP_PROBE(receive, NULL, inp, ip, inp, uh);
745 	if (udp_append(inp, ip, m, iphlen, udp_in) == 0)
746 		INP_RUNLOCK(inp);
747 	return (IPPROTO_DONE);
748 
749 badunlocked:
750 	m_freem(m);
751 	return (IPPROTO_DONE);
752 }
753 #endif /* INET */
754 
755 /*
756  * Notify a udp user of an asynchronous error; just wake up so that they can
757  * collect error status.
758  */
759 struct inpcb *
760 udp_notify(struct inpcb *inp, int errno)
761 {
762 
763 	INP_WLOCK_ASSERT(inp);
764 	if ((errno == EHOSTUNREACH || errno == ENETUNREACH ||
765 	     errno == EHOSTDOWN) && inp->inp_route.ro_nh) {
766 		NH_FREE(inp->inp_route.ro_nh);
767 		inp->inp_route.ro_nh = (struct nhop_object *)NULL;
768 	}
769 
770 	inp->inp_socket->so_error = errno;
771 	sorwakeup(inp->inp_socket);
772 	sowwakeup(inp->inp_socket);
773 	return (inp);
774 }
775 
776 #ifdef INET
777 static void
778 udp_common_ctlinput(int cmd, struct sockaddr *sa, void *vip,
779     struct inpcbinfo *pcbinfo)
780 {
781 	struct ip *ip = vip;
782 	struct udphdr *uh;
783 	struct in_addr faddr;
784 	struct inpcb *inp;
785 
786 	faddr = ((struct sockaddr_in *)sa)->sin_addr;
787 	if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
788 		return;
789 
790 	if (PRC_IS_REDIRECT(cmd)) {
791 		/* signal EHOSTDOWN, as it flushes the cached route */
792 		in_pcbnotifyall(&V_udbinfo, faddr, EHOSTDOWN, udp_notify);
793 		return;
794 	}
795 
796 	/*
797 	 * Hostdead is ugly because it goes linearly through all PCBs.
798 	 *
799 	 * XXX: We never get this from ICMP, otherwise it makes an excellent
800 	 * DoS attack on machines with many connections.
801 	 */
802 	if (cmd == PRC_HOSTDEAD)
803 		ip = NULL;
804 	else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
805 		return;
806 	if (ip != NULL) {
807 		uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
808 		inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
809 		    ip->ip_src, uh->uh_sport, INPLOOKUP_WLOCKPCB, NULL);
810 		if (inp != NULL) {
811 			INP_WLOCK_ASSERT(inp);
812 			if (inp->inp_socket != NULL) {
813 				udp_notify(inp, inetctlerrmap[cmd]);
814 			}
815 			INP_WUNLOCK(inp);
816 		} else {
817 			inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
818 					   ip->ip_src, uh->uh_sport,
819 					   INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
820 			if (inp != NULL) {
821 				struct udpcb *up;
822 				void *ctx;
823 				udp_tun_icmp_t func;
824 
825 				up = intoudpcb(inp);
826 				ctx = up->u_tun_ctx;
827 				func = up->u_icmp_func;
828 				INP_RUNLOCK(inp);
829 				if (func != NULL)
830 					(*func)(cmd, sa, vip, ctx);
831 			}
832 		}
833 	} else
834 		in_pcbnotifyall(pcbinfo, faddr, inetctlerrmap[cmd],
835 		    udp_notify);
836 }
837 void
838 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
839 {
840 
841 	return (udp_common_ctlinput(cmd, sa, vip, &V_udbinfo));
842 }
843 
844 void
845 udplite_ctlinput(int cmd, struct sockaddr *sa, void *vip)
846 {
847 
848 	return (udp_common_ctlinput(cmd, sa, vip, &V_ulitecbinfo));
849 }
850 #endif /* INET */
851 
852 static int
853 udp_pcblist(SYSCTL_HANDLER_ARGS)
854 {
855 	struct xinpgen xig;
856 	struct epoch_tracker et;
857 	struct inpcb *inp;
858 	int error;
859 
860 	if (req->newptr != 0)
861 		return (EPERM);
862 
863 	if (req->oldptr == 0) {
864 		int n;
865 
866 		n = V_udbinfo.ipi_count;
867 		n += imax(n / 8, 10);
868 		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
869 		return (0);
870 	}
871 
872 	if ((error = sysctl_wire_old_buffer(req, 0)) != 0)
873 		return (error);
874 
875 	bzero(&xig, sizeof(xig));
876 	xig.xig_len = sizeof xig;
877 	xig.xig_count = V_udbinfo.ipi_count;
878 	xig.xig_gen = V_udbinfo.ipi_gencnt;
879 	xig.xig_sogen = so_gencnt;
880 	error = SYSCTL_OUT(req, &xig, sizeof xig);
881 	if (error)
882 		return (error);
883 
884 	NET_EPOCH_ENTER(et);
885 	for (inp = CK_LIST_FIRST(V_udbinfo.ipi_listhead);
886 	    inp != NULL;
887 	    inp = CK_LIST_NEXT(inp, inp_list)) {
888 		INP_RLOCK(inp);
889 		if (inp->inp_gencnt <= xig.xig_gen &&
890 		    cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
891 			struct xinpcb xi;
892 
893 			in_pcbtoxinpcb(inp, &xi);
894 			INP_RUNLOCK(inp);
895 			error = SYSCTL_OUT(req, &xi, sizeof xi);
896 			if (error)
897 				break;
898 		} else
899 			INP_RUNLOCK(inp);
900 	}
901 	NET_EPOCH_EXIT(et);
902 
903 	if (!error) {
904 		/*
905 		 * Give the user an updated idea of our state.  If the
906 		 * generation differs from what we told her before, she knows
907 		 * that something happened while we were processing this
908 		 * request, and it might be necessary to retry.
909 		 */
910 		xig.xig_gen = V_udbinfo.ipi_gencnt;
911 		xig.xig_sogen = so_gencnt;
912 		xig.xig_count = V_udbinfo.ipi_count;
913 		error = SYSCTL_OUT(req, &xig, sizeof xig);
914 	}
915 
916 	return (error);
917 }
918 
919 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
920     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
921     udp_pcblist, "S,xinpcb",
922     "List of active UDP sockets");
923 
924 #ifdef INET
925 static int
926 udp_getcred(SYSCTL_HANDLER_ARGS)
927 {
928 	struct xucred xuc;
929 	struct sockaddr_in addrs[2];
930 	struct epoch_tracker et;
931 	struct inpcb *inp;
932 	int error;
933 
934 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
935 	if (error)
936 		return (error);
937 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
938 	if (error)
939 		return (error);
940 	NET_EPOCH_ENTER(et);
941 	inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
942 	    addrs[0].sin_addr, addrs[0].sin_port,
943 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
944 	NET_EPOCH_EXIT(et);
945 	if (inp != NULL) {
946 		INP_RLOCK_ASSERT(inp);
947 		if (inp->inp_socket == NULL)
948 			error = ENOENT;
949 		if (error == 0)
950 			error = cr_canseeinpcb(req->td->td_ucred, inp);
951 		if (error == 0)
952 			cru2x(inp->inp_cred, &xuc);
953 		INP_RUNLOCK(inp);
954 	} else
955 		error = ENOENT;
956 	if (error == 0)
957 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
958 	return (error);
959 }
960 
961 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
962     CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
963     0, 0, udp_getcred, "S,xucred",
964     "Get the xucred of a UDP connection");
965 #endif /* INET */
966 
967 int
968 udp_ctloutput(struct socket *so, struct sockopt *sopt)
969 {
970 	struct inpcb *inp;
971 	struct udpcb *up;
972 	int isudplite, error, optval;
973 
974 	error = 0;
975 	isudplite = (so->so_proto->pr_protocol == IPPROTO_UDPLITE) ? 1 : 0;
976 	inp = sotoinpcb(so);
977 	KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
978 	INP_WLOCK(inp);
979 	if (sopt->sopt_level != so->so_proto->pr_protocol) {
980 #ifdef INET6
981 		if (INP_CHECK_SOCKAF(so, AF_INET6)) {
982 			INP_WUNLOCK(inp);
983 			error = ip6_ctloutput(so, sopt);
984 		}
985 #endif
986 #if defined(INET) && defined(INET6)
987 		else
988 #endif
989 #ifdef INET
990 		{
991 			INP_WUNLOCK(inp);
992 			error = ip_ctloutput(so, sopt);
993 		}
994 #endif
995 		return (error);
996 	}
997 
998 	switch (sopt->sopt_dir) {
999 	case SOPT_SET:
1000 		switch (sopt->sopt_name) {
1001 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1002 #ifdef INET
1003 		case UDP_ENCAP:
1004 			if (!IPSEC_ENABLED(ipv4)) {
1005 				INP_WUNLOCK(inp);
1006 				return (ENOPROTOOPT);
1007 			}
1008 			error = UDPENCAP_PCBCTL(inp, sopt);
1009 			break;
1010 #endif /* INET */
1011 #endif /* IPSEC */
1012 		case UDPLITE_SEND_CSCOV:
1013 		case UDPLITE_RECV_CSCOV:
1014 			if (!isudplite) {
1015 				INP_WUNLOCK(inp);
1016 				error = ENOPROTOOPT;
1017 				break;
1018 			}
1019 			INP_WUNLOCK(inp);
1020 			error = sooptcopyin(sopt, &optval, sizeof(optval),
1021 			    sizeof(optval));
1022 			if (error != 0)
1023 				break;
1024 			inp = sotoinpcb(so);
1025 			KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
1026 			INP_WLOCK(inp);
1027 			up = intoudpcb(inp);
1028 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
1029 			if ((optval != 0 && optval < 8) || (optval > 65535)) {
1030 				INP_WUNLOCK(inp);
1031 				error = EINVAL;
1032 				break;
1033 			}
1034 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1035 				up->u_txcslen = optval;
1036 			else
1037 				up->u_rxcslen = optval;
1038 			INP_WUNLOCK(inp);
1039 			break;
1040 		default:
1041 			INP_WUNLOCK(inp);
1042 			error = ENOPROTOOPT;
1043 			break;
1044 		}
1045 		break;
1046 	case SOPT_GET:
1047 		switch (sopt->sopt_name) {
1048 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1049 #ifdef INET
1050 		case UDP_ENCAP:
1051 			if (!IPSEC_ENABLED(ipv4)) {
1052 				INP_WUNLOCK(inp);
1053 				return (ENOPROTOOPT);
1054 			}
1055 			error = UDPENCAP_PCBCTL(inp, sopt);
1056 			break;
1057 #endif /* INET */
1058 #endif /* IPSEC */
1059 		case UDPLITE_SEND_CSCOV:
1060 		case UDPLITE_RECV_CSCOV:
1061 			if (!isudplite) {
1062 				INP_WUNLOCK(inp);
1063 				error = ENOPROTOOPT;
1064 				break;
1065 			}
1066 			up = intoudpcb(inp);
1067 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
1068 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1069 				optval = up->u_txcslen;
1070 			else
1071 				optval = up->u_rxcslen;
1072 			INP_WUNLOCK(inp);
1073 			error = sooptcopyout(sopt, &optval, sizeof(optval));
1074 			break;
1075 		default:
1076 			INP_WUNLOCK(inp);
1077 			error = ENOPROTOOPT;
1078 			break;
1079 		}
1080 		break;
1081 	}
1082 	return (error);
1083 }
1084 
1085 #ifdef INET
1086 static int
1087 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
1088     struct mbuf *control, struct thread *td)
1089 {
1090 	struct udpiphdr *ui;
1091 	int len = m->m_pkthdr.len;
1092 	struct in_addr faddr, laddr;
1093 	struct cmsghdr *cm;
1094 	struct inpcbinfo *pcbinfo;
1095 	struct sockaddr_in *sin, src;
1096 	struct epoch_tracker et;
1097 	int cscov_partial = 0;
1098 	int error = 0;
1099 	int ipflags;
1100 	u_short fport, lport;
1101 	u_char tos;
1102 	uint8_t pr;
1103 	uint16_t cscov = 0;
1104 	uint32_t flowid = 0;
1105 	uint8_t flowtype = M_HASHTYPE_NONE;
1106 
1107 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1108 		if (control)
1109 			m_freem(control);
1110 		m_freem(m);
1111 		return (EMSGSIZE);
1112 	}
1113 
1114 	src.sin_family = 0;
1115 	sin = (struct sockaddr_in *)addr;
1116 
1117 	/*
1118 	 * udp_output() may need to temporarily bind or connect the current
1119 	 * inpcb.  As such, we don't know up front whether we will need the
1120 	 * pcbinfo lock or not.  Do any work to decide what is needed up
1121 	 * front before acquiring any locks.
1122 	 *
1123 	 * We will need network epoch in either case, to safely lookup into
1124 	 * pcb hash.
1125 	 */
1126 	if (sin == NULL ||
1127 	    (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0))
1128 		INP_WLOCK(inp);
1129 	else
1130 		INP_RLOCK(inp);
1131 	NET_EPOCH_ENTER(et);
1132 	tos = inp->inp_ip_tos;
1133 	if (control != NULL) {
1134 		/*
1135 		 * XXX: Currently, we assume all the optional information is
1136 		 * stored in a single mbuf.
1137 		 */
1138 		if (control->m_next) {
1139 			m_freem(control);
1140 			error = EINVAL;
1141 			goto release;
1142 		}
1143 		for (; control->m_len > 0;
1144 		    control->m_data += CMSG_ALIGN(cm->cmsg_len),
1145 		    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1146 			cm = mtod(control, struct cmsghdr *);
1147 			if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1148 			    || cm->cmsg_len > control->m_len) {
1149 				error = EINVAL;
1150 				break;
1151 			}
1152 			if (cm->cmsg_level != IPPROTO_IP)
1153 				continue;
1154 
1155 			switch (cm->cmsg_type) {
1156 			case IP_SENDSRCADDR:
1157 				if (cm->cmsg_len !=
1158 				    CMSG_LEN(sizeof(struct in_addr))) {
1159 					error = EINVAL;
1160 					break;
1161 				}
1162 				bzero(&src, sizeof(src));
1163 				src.sin_family = AF_INET;
1164 				src.sin_len = sizeof(src);
1165 				src.sin_port = inp->inp_lport;
1166 				src.sin_addr =
1167 				    *(struct in_addr *)CMSG_DATA(cm);
1168 				break;
1169 
1170 			case IP_TOS:
1171 				if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1172 					error = EINVAL;
1173 					break;
1174 				}
1175 				tos = *(u_char *)CMSG_DATA(cm);
1176 				break;
1177 
1178 			case IP_FLOWID:
1179 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1180 					error = EINVAL;
1181 					break;
1182 				}
1183 				flowid = *(uint32_t *) CMSG_DATA(cm);
1184 				break;
1185 
1186 			case IP_FLOWTYPE:
1187 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1188 					error = EINVAL;
1189 					break;
1190 				}
1191 				flowtype = *(uint32_t *) CMSG_DATA(cm);
1192 				break;
1193 
1194 #ifdef	RSS
1195 			case IP_RSSBUCKETID:
1196 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1197 					error = EINVAL;
1198 					break;
1199 				}
1200 				/* This is just a placeholder for now */
1201 				break;
1202 #endif	/* RSS */
1203 			default:
1204 				error = ENOPROTOOPT;
1205 				break;
1206 			}
1207 			if (error)
1208 				break;
1209 		}
1210 		m_freem(control);
1211 	}
1212 	if (error)
1213 		goto release;
1214 
1215 	pr = inp->inp_socket->so_proto->pr_protocol;
1216 	pcbinfo = udp_get_inpcbinfo(pr);
1217 
1218 	/*
1219 	 * If the IP_SENDSRCADDR control message was specified, override the
1220 	 * source address for this datagram.  Its use is invalidated if the
1221 	 * address thus specified is incomplete or clobbers other inpcbs.
1222 	 */
1223 	laddr = inp->inp_laddr;
1224 	lport = inp->inp_lport;
1225 	if (src.sin_family == AF_INET) {
1226 		INP_HASH_LOCK_ASSERT(pcbinfo);
1227 		if ((lport == 0) ||
1228 		    (laddr.s_addr == INADDR_ANY &&
1229 		     src.sin_addr.s_addr == INADDR_ANY)) {
1230 			error = EINVAL;
1231 			goto release;
1232 		}
1233 		error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1234 		    &laddr.s_addr, &lport, td->td_ucred);
1235 		if (error)
1236 			goto release;
1237 	}
1238 
1239 	/*
1240 	 * If a UDP socket has been connected, then a local address/port will
1241 	 * have been selected and bound.
1242 	 *
1243 	 * If a UDP socket has not been connected to, then an explicit
1244 	 * destination address must be used, in which case a local
1245 	 * address/port may not have been selected and bound.
1246 	 */
1247 	if (sin != NULL) {
1248 		INP_LOCK_ASSERT(inp);
1249 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1250 			error = EISCONN;
1251 			goto release;
1252 		}
1253 
1254 		/*
1255 		 * Jail may rewrite the destination address, so let it do
1256 		 * that before we use it.
1257 		 */
1258 		error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1259 		if (error)
1260 			goto release;
1261 
1262 		/*
1263 		 * If a local address or port hasn't yet been selected, or if
1264 		 * the destination address needs to be rewritten due to using
1265 		 * a special INADDR_ constant, invoke in_pcbconnect_setup()
1266 		 * to do the heavy lifting.  Once a port is selected, we
1267 		 * commit the binding back to the socket; we also commit the
1268 		 * binding of the address if in jail.
1269 		 *
1270 		 * If we already have a valid binding and we're not
1271 		 * requesting a destination address rewrite, use a fast path.
1272 		 */
1273 		if (inp->inp_laddr.s_addr == INADDR_ANY ||
1274 		    inp->inp_lport == 0 ||
1275 		    sin->sin_addr.s_addr == INADDR_ANY ||
1276 		    sin->sin_addr.s_addr == INADDR_BROADCAST) {
1277 			INP_HASH_LOCK_ASSERT(pcbinfo);
1278 			error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1279 			    &lport, &faddr.s_addr, &fport, NULL,
1280 			    td->td_ucred);
1281 			if (error)
1282 				goto release;
1283 
1284 			/*
1285 			 * XXXRW: Why not commit the port if the address is
1286 			 * !INADDR_ANY?
1287 			 */
1288 			/* Commit the local port if newly assigned. */
1289 			if (inp->inp_laddr.s_addr == INADDR_ANY &&
1290 			    inp->inp_lport == 0) {
1291 				INP_WLOCK_ASSERT(inp);
1292 				/*
1293 				 * Remember addr if jailed, to prevent
1294 				 * rebinding.
1295 				 */
1296 				if (prison_flag(td->td_ucred, PR_IP4))
1297 					inp->inp_laddr = laddr;
1298 				inp->inp_lport = lport;
1299 				INP_HASH_WLOCK(pcbinfo);
1300 				error = in_pcbinshash(inp);
1301 				INP_HASH_WUNLOCK(pcbinfo);
1302 				if (error != 0) {
1303 					inp->inp_lport = 0;
1304 					error = EAGAIN;
1305 					goto release;
1306 				}
1307 				inp->inp_flags |= INP_ANONPORT;
1308 			}
1309 		} else {
1310 			faddr = sin->sin_addr;
1311 			fport = sin->sin_port;
1312 		}
1313 	} else {
1314 		INP_LOCK_ASSERT(inp);
1315 		faddr = inp->inp_faddr;
1316 		fport = inp->inp_fport;
1317 		if (faddr.s_addr == INADDR_ANY) {
1318 			error = ENOTCONN;
1319 			goto release;
1320 		}
1321 	}
1322 
1323 	/*
1324 	 * Calculate data length and get a mbuf for UDP, IP, and possible
1325 	 * link-layer headers.  Immediate slide the data pointer back forward
1326 	 * since we won't use that space at this layer.
1327 	 */
1328 	M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1329 	if (m == NULL) {
1330 		error = ENOBUFS;
1331 		goto release;
1332 	}
1333 	m->m_data += max_linkhdr;
1334 	m->m_len -= max_linkhdr;
1335 	m->m_pkthdr.len -= max_linkhdr;
1336 
1337 	/*
1338 	 * Fill in mbuf with extended UDP header and addresses and length put
1339 	 * into network format.
1340 	 */
1341 	ui = mtod(m, struct udpiphdr *);
1342 	bzero(ui->ui_x1, sizeof(ui->ui_x1));	/* XXX still needed? */
1343 	ui->ui_v = IPVERSION << 4;
1344 	ui->ui_pr = pr;
1345 	ui->ui_src = laddr;
1346 	ui->ui_dst = faddr;
1347 	ui->ui_sport = lport;
1348 	ui->ui_dport = fport;
1349 	ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1350 	if (pr == IPPROTO_UDPLITE) {
1351 		struct udpcb *up;
1352 		uint16_t plen;
1353 
1354 		up = intoudpcb(inp);
1355 		cscov = up->u_txcslen;
1356 		plen = (u_short)len + sizeof(struct udphdr);
1357 		if (cscov >= plen)
1358 			cscov = 0;
1359 		ui->ui_len = htons(plen);
1360 		ui->ui_ulen = htons(cscov);
1361 		/*
1362 		 * For UDP-Lite, checksum coverage length of zero means
1363 		 * the entire UDPLite packet is covered by the checksum.
1364 		 */
1365 		cscov_partial = (cscov == 0) ? 0 : 1;
1366 	}
1367 
1368 	/*
1369 	 * Set the Don't Fragment bit in the IP header.
1370 	 */
1371 	if (inp->inp_flags & INP_DONTFRAG) {
1372 		struct ip *ip;
1373 
1374 		ip = (struct ip *)&ui->ui_i;
1375 		ip->ip_off |= htons(IP_DF);
1376 	}
1377 
1378 	ipflags = 0;
1379 	if (inp->inp_socket->so_options & SO_DONTROUTE)
1380 		ipflags |= IP_ROUTETOIF;
1381 	if (inp->inp_socket->so_options & SO_BROADCAST)
1382 		ipflags |= IP_ALLOWBROADCAST;
1383 	if (inp->inp_flags & INP_ONESBCAST)
1384 		ipflags |= IP_SENDONES;
1385 
1386 #ifdef MAC
1387 	mac_inpcb_create_mbuf(inp, m);
1388 #endif
1389 
1390 	/*
1391 	 * Set up checksum and output datagram.
1392 	 */
1393 	ui->ui_sum = 0;
1394 	if (pr == IPPROTO_UDPLITE) {
1395 		if (inp->inp_flags & INP_ONESBCAST)
1396 			faddr.s_addr = INADDR_BROADCAST;
1397 		if (cscov_partial) {
1398 			if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
1399 				ui->ui_sum = 0xffff;
1400 		} else {
1401 			if ((ui->ui_sum = in_cksum(m, sizeof(struct udpiphdr) + len)) == 0)
1402 				ui->ui_sum = 0xffff;
1403 		}
1404 	} else if (V_udp_cksum) {
1405 		if (inp->inp_flags & INP_ONESBCAST)
1406 			faddr.s_addr = INADDR_BROADCAST;
1407 		ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1408 		    htons((u_short)len + sizeof(struct udphdr) + pr));
1409 		m->m_pkthdr.csum_flags = CSUM_UDP;
1410 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1411 	}
1412 	((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1413 	((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;	/* XXX */
1414 	((struct ip *)ui)->ip_tos = tos;		/* XXX */
1415 	UDPSTAT_INC(udps_opackets);
1416 
1417 	/*
1418 	 * Setup flowid / RSS information for outbound socket.
1419 	 *
1420 	 * Once the UDP code decides to set a flowid some other way,
1421 	 * this allows the flowid to be overridden by userland.
1422 	 */
1423 	if (flowtype != M_HASHTYPE_NONE) {
1424 		m->m_pkthdr.flowid = flowid;
1425 		M_HASHTYPE_SET(m, flowtype);
1426 	}
1427 #ifdef	RSS
1428 	else {
1429 		uint32_t hash_val, hash_type;
1430 		/*
1431 		 * Calculate an appropriate RSS hash for UDP and
1432 		 * UDP Lite.
1433 		 *
1434 		 * The called function will take care of figuring out
1435 		 * whether a 2-tuple or 4-tuple hash is required based
1436 		 * on the currently configured scheme.
1437 		 *
1438 		 * Later later on connected socket values should be
1439 		 * cached in the inpcb and reused, rather than constantly
1440 		 * re-calculating it.
1441 		 *
1442 		 * UDP Lite is a different protocol number and will
1443 		 * likely end up being hashed as a 2-tuple until
1444 		 * RSS / NICs grow UDP Lite protocol awareness.
1445 		 */
1446 		if (rss_proto_software_hash_v4(faddr, laddr, fport, lport,
1447 		    pr, &hash_val, &hash_type) == 0) {
1448 			m->m_pkthdr.flowid = hash_val;
1449 			M_HASHTYPE_SET(m, hash_type);
1450 		}
1451 	}
1452 
1453 	/*
1454 	 * Don't override with the inp cached flowid value.
1455 	 *
1456 	 * Depending upon the kind of send being done, the inp
1457 	 * flowid/flowtype values may actually not be appropriate
1458 	 * for this particular socket send.
1459 	 *
1460 	 * We should either leave the flowid at zero (which is what is
1461 	 * currently done) or set it to some software generated
1462 	 * hash value based on the packet contents.
1463 	 */
1464 	ipflags |= IP_NODEFAULTFLOWID;
1465 #endif	/* RSS */
1466 
1467 	if (pr == IPPROTO_UDPLITE)
1468 		UDPLITE_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1469 	else
1470 		UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1471 	error = ip_output(m, inp->inp_options,
1472 	    INP_WLOCKED(inp) ? &inp->inp_route : NULL, ipflags,
1473 	    inp->inp_moptions, inp);
1474 	INP_UNLOCK(inp);
1475 	NET_EPOCH_EXIT(et);
1476 	return (error);
1477 
1478 release:
1479 	INP_UNLOCK(inp);
1480 	NET_EPOCH_EXIT(et);
1481 	m_freem(m);
1482 	return (error);
1483 }
1484 
1485 static void
1486 udp_abort(struct socket *so)
1487 {
1488 	struct inpcb *inp;
1489 	struct inpcbinfo *pcbinfo;
1490 
1491 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1492 	inp = sotoinpcb(so);
1493 	KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1494 	INP_WLOCK(inp);
1495 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1496 		INP_HASH_WLOCK(pcbinfo);
1497 		in_pcbdisconnect(inp);
1498 		inp->inp_laddr.s_addr = INADDR_ANY;
1499 		INP_HASH_WUNLOCK(pcbinfo);
1500 		soisdisconnected(so);
1501 	}
1502 	INP_WUNLOCK(inp);
1503 }
1504 
1505 static int
1506 udp_attach(struct socket *so, int proto, struct thread *td)
1507 {
1508 	static uint32_t udp_flowid;
1509 	struct inpcb *inp;
1510 	struct inpcbinfo *pcbinfo;
1511 	int error;
1512 
1513 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1514 	inp = sotoinpcb(so);
1515 	KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1516 	error = soreserve(so, udp_sendspace, udp_recvspace);
1517 	if (error)
1518 		return (error);
1519 	INP_INFO_WLOCK(pcbinfo);
1520 	error = in_pcballoc(so, pcbinfo);
1521 	if (error) {
1522 		INP_INFO_WUNLOCK(pcbinfo);
1523 		return (error);
1524 	}
1525 
1526 	inp = sotoinpcb(so);
1527 	inp->inp_vflag |= INP_IPV4;
1528 	inp->inp_ip_ttl = V_ip_defttl;
1529 	inp->inp_flowid = atomic_fetchadd_int(&udp_flowid, 1);
1530 	inp->inp_flowtype = M_HASHTYPE_OPAQUE;
1531 
1532 	error = udp_newudpcb(inp);
1533 	if (error) {
1534 		in_pcbdetach(inp);
1535 		in_pcbfree(inp);
1536 		INP_INFO_WUNLOCK(pcbinfo);
1537 		return (error);
1538 	}
1539 
1540 	INP_WUNLOCK(inp);
1541 	INP_INFO_WUNLOCK(pcbinfo);
1542 	return (0);
1543 }
1544 #endif /* INET */
1545 
1546 int
1547 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f, udp_tun_icmp_t i, void *ctx)
1548 {
1549 	struct inpcb *inp;
1550 	struct udpcb *up;
1551 
1552 	KASSERT(so->so_type == SOCK_DGRAM,
1553 	    ("udp_set_kernel_tunneling: !dgram"));
1554 	inp = sotoinpcb(so);
1555 	KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1556 	INP_WLOCK(inp);
1557 	up = intoudpcb(inp);
1558 	if ((up->u_tun_func != NULL) ||
1559 	    (up->u_icmp_func != NULL)) {
1560 		INP_WUNLOCK(inp);
1561 		return (EBUSY);
1562 	}
1563 	up->u_tun_func = f;
1564 	up->u_icmp_func = i;
1565 	up->u_tun_ctx = ctx;
1566 	INP_WUNLOCK(inp);
1567 	return (0);
1568 }
1569 
1570 #ifdef INET
1571 static int
1572 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1573 {
1574 	struct inpcb *inp;
1575 	struct inpcbinfo *pcbinfo;
1576 	int error;
1577 
1578 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1579 	inp = sotoinpcb(so);
1580 	KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1581 	INP_WLOCK(inp);
1582 	INP_HASH_WLOCK(pcbinfo);
1583 	error = in_pcbbind(inp, nam, td->td_ucred);
1584 	INP_HASH_WUNLOCK(pcbinfo);
1585 	INP_WUNLOCK(inp);
1586 	return (error);
1587 }
1588 
1589 static void
1590 udp_close(struct socket *so)
1591 {
1592 	struct inpcb *inp;
1593 	struct inpcbinfo *pcbinfo;
1594 
1595 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1596 	inp = sotoinpcb(so);
1597 	KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1598 	INP_WLOCK(inp);
1599 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1600 		INP_HASH_WLOCK(pcbinfo);
1601 		in_pcbdisconnect(inp);
1602 		inp->inp_laddr.s_addr = INADDR_ANY;
1603 		INP_HASH_WUNLOCK(pcbinfo);
1604 		soisdisconnected(so);
1605 	}
1606 	INP_WUNLOCK(inp);
1607 }
1608 
1609 static int
1610 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1611 {
1612 	struct epoch_tracker et;
1613 	struct inpcb *inp;
1614 	struct inpcbinfo *pcbinfo;
1615 	struct sockaddr_in *sin;
1616 	int error;
1617 
1618 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1619 	inp = sotoinpcb(so);
1620 	KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1621 	INP_WLOCK(inp);
1622 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1623 		INP_WUNLOCK(inp);
1624 		return (EISCONN);
1625 	}
1626 	sin = (struct sockaddr_in *)nam;
1627 	error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1628 	if (error != 0) {
1629 		INP_WUNLOCK(inp);
1630 		return (error);
1631 	}
1632 	NET_EPOCH_ENTER(et);
1633 	INP_HASH_WLOCK(pcbinfo);
1634 	error = in_pcbconnect(inp, nam, td->td_ucred);
1635 	INP_HASH_WUNLOCK(pcbinfo);
1636 	NET_EPOCH_EXIT(et);
1637 	if (error == 0)
1638 		soisconnected(so);
1639 	INP_WUNLOCK(inp);
1640 	return (error);
1641 }
1642 
1643 static void
1644 udp_detach(struct socket *so)
1645 {
1646 	struct inpcb *inp;
1647 	struct inpcbinfo *pcbinfo;
1648 	struct udpcb *up;
1649 
1650 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1651 	inp = sotoinpcb(so);
1652 	KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1653 	KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1654 	    ("udp_detach: not disconnected"));
1655 	INP_INFO_WLOCK(pcbinfo);
1656 	INP_WLOCK(inp);
1657 	up = intoudpcb(inp);
1658 	KASSERT(up != NULL, ("%s: up == NULL", __func__));
1659 	inp->inp_ppcb = NULL;
1660 	in_pcbdetach(inp);
1661 	in_pcbfree(inp);
1662 	INP_INFO_WUNLOCK(pcbinfo);
1663 	udp_discardcb(up);
1664 }
1665 
1666 static int
1667 udp_disconnect(struct socket *so)
1668 {
1669 	struct inpcb *inp;
1670 	struct inpcbinfo *pcbinfo;
1671 
1672 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1673 	inp = sotoinpcb(so);
1674 	KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1675 	INP_WLOCK(inp);
1676 	if (inp->inp_faddr.s_addr == INADDR_ANY) {
1677 		INP_WUNLOCK(inp);
1678 		return (ENOTCONN);
1679 	}
1680 	INP_HASH_WLOCK(pcbinfo);
1681 	in_pcbdisconnect(inp);
1682 	inp->inp_laddr.s_addr = INADDR_ANY;
1683 	INP_HASH_WUNLOCK(pcbinfo);
1684 	SOCK_LOCK(so);
1685 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1686 	SOCK_UNLOCK(so);
1687 	INP_WUNLOCK(inp);
1688 	return (0);
1689 }
1690 
1691 static int
1692 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1693     struct mbuf *control, struct thread *td)
1694 {
1695 	struct inpcb *inp;
1696 
1697 	inp = sotoinpcb(so);
1698 	KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1699 	return (udp_output(inp, m, addr, control, td));
1700 }
1701 #endif /* INET */
1702 
1703 int
1704 udp_shutdown(struct socket *so)
1705 {
1706 	struct inpcb *inp;
1707 
1708 	inp = sotoinpcb(so);
1709 	KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1710 	INP_WLOCK(inp);
1711 	socantsendmore(so);
1712 	INP_WUNLOCK(inp);
1713 	return (0);
1714 }
1715 
1716 #ifdef INET
1717 struct pr_usrreqs udp_usrreqs = {
1718 	.pru_abort =		udp_abort,
1719 	.pru_attach =		udp_attach,
1720 	.pru_bind =		udp_bind,
1721 	.pru_connect =		udp_connect,
1722 	.pru_control =		in_control,
1723 	.pru_detach =		udp_detach,
1724 	.pru_disconnect =	udp_disconnect,
1725 	.pru_peeraddr =		in_getpeeraddr,
1726 	.pru_send =		udp_send,
1727 	.pru_soreceive =	soreceive_dgram,
1728 	.pru_sosend =		sosend_dgram,
1729 	.pru_shutdown =		udp_shutdown,
1730 	.pru_sockaddr =		in_getsockaddr,
1731 	.pru_sosetlabel =	in_pcbsosetlabel,
1732 	.pru_close =		udp_close,
1733 };
1734 #endif /* INET */
1735