xref: /freebsd/sys/netinet/udp_usrreq.c (revision 7b71f57f4e514a2ab7308ce4147e14d90e099ad0)
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 "opt_inet.h"
40 #include "opt_inet6.h"
41 #include "opt_ipsec.h"
42 #include "opt_route.h"
43 #include "opt_rss.h"
44 
45 #include <sys/param.h>
46 #include <sys/domain.h>
47 #include <sys/eventhandler.h>
48 #include <sys/jail.h>
49 #include <sys/kernel.h>
50 #include <sys/lock.h>
51 #include <sys/malloc.h>
52 #include <sys/mbuf.h>
53 #include <sys/priv.h>
54 #include <sys/proc.h>
55 #include <sys/protosw.h>
56 #include <sys/sdt.h>
57 #include <sys/signalvar.h>
58 #include <sys/socket.h>
59 #include <sys/socketvar.h>
60 #include <sys/sx.h>
61 #include <sys/sysctl.h>
62 #include <sys/syslog.h>
63 #include <sys/systm.h>
64 
65 #include <vm/uma.h>
66 
67 #include <net/if.h>
68 #include <net/if_var.h>
69 #include <net/route.h>
70 #include <net/route/nhop.h>
71 #include <net/rss_config.h>
72 
73 #include <netinet/in.h>
74 #include <netinet/in_kdtrace.h>
75 #include <netinet/in_fib.h>
76 #include <netinet/in_pcb.h>
77 #include <netinet/in_systm.h>
78 #include <netinet/in_var.h>
79 #include <netinet/ip.h>
80 #ifdef INET6
81 #include <netinet/ip6.h>
82 #endif
83 #include <netinet/ip_icmp.h>
84 #include <netinet/icmp_var.h>
85 #include <netinet/ip_var.h>
86 #include <netinet/ip_options.h>
87 #ifdef INET6
88 #include <netinet6/ip6_var.h>
89 #endif
90 #include <netinet/udp.h>
91 #include <netinet/udp_var.h>
92 #include <netinet/udplite.h>
93 #include <netinet/in_rss.h>
94 
95 #include <netipsec/ipsec_support.h>
96 
97 #include <machine/in_cksum.h>
98 
99 #include <security/mac/mac_framework.h>
100 
101 /*
102  * UDP and UDP-Lite protocols implementation.
103  * Per RFC 768, August, 1980.
104  * Per RFC 3828, July, 2004.
105  */
106 
107 VNET_DEFINE(int, udp_bind_all_fibs) = 1;
108 SYSCTL_INT(_net_inet_udp, OID_AUTO, bind_all_fibs, CTLFLAG_VNET | CTLFLAG_RDTUN,
109     &VNET_NAME(udp_bind_all_fibs), 0,
110     "Bound sockets receive traffic from all FIBs");
111 
112 /*
113  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
114  * removes the only data integrity mechanism for packets and malformed
115  * packets that would otherwise be discarded due to bad checksums, and may
116  * cause problems (especially for NFS data blocks).
117  */
118 VNET_DEFINE(int, udp_cksum) = 1;
119 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_VNET | CTLFLAG_RW,
120     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
121 
122 VNET_DEFINE(int, udp_log_in_vain) = 0;
123 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_VNET | CTLFLAG_RW,
124     &VNET_NAME(udp_log_in_vain), 0, "Log all incoming UDP packets");
125 
126 VNET_DEFINE(int, udp_blackhole) = 0;
127 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_VNET | CTLFLAG_RW,
128     &VNET_NAME(udp_blackhole), 0,
129     "Do not send port unreachables for refused connects");
130 VNET_DEFINE(bool, udp_blackhole_local) = false;
131 SYSCTL_BOOL(_net_inet_udp, OID_AUTO, blackhole_local, CTLFLAG_VNET |
132     CTLFLAG_RW, &VNET_NAME(udp_blackhole_local), false,
133     "Enforce net.inet.udp.blackhole for locally originated packets");
134 
135 u_long	udp_sendspace = 9216;		/* really max datagram size */
136 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
137     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
138 
139 u_long	udp_recvspace = 40 * (1024 +
140 #ifdef INET6
141 				      sizeof(struct sockaddr_in6)
142 #else
143 				      sizeof(struct sockaddr_in)
144 #endif
145 				      );	/* 40 1K datagrams */
146 
147 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
148     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
149 
150 VNET_DEFINE(struct inpcbinfo, udbinfo);
151 VNET_DEFINE(struct inpcbinfo, ulitecbinfo);
152 
153 #ifndef UDBHASHSIZE
154 #define	UDBHASHSIZE	128
155 #endif
156 
157 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);		/* from udp_var.h */
158 VNET_PCPUSTAT_SYSINIT(udpstat);
159 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
160     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
161 
162 #ifdef VIMAGE
163 VNET_PCPUSTAT_SYSUNINIT(udpstat);
164 #endif /* VIMAGE */
165 #ifdef INET
166 static void	udp_detach(struct socket *so);
167 #endif
168 
169 INPCBSTORAGE_DEFINE(udpcbstor, udpcb, "udpinp", "udp_inpcb", "udp", "udphash");
170 INPCBSTORAGE_DEFINE(udplitecbstor, udpcb, "udpliteinp", "udplite_inpcb",
171     "udplite", "udplitehash");
172 
173 static void
udp_vnet_init(void * arg __unused)174 udp_vnet_init(void *arg __unused)
175 {
176 
177 	/*
178 	 * For now default to 2-tuple UDP hashing - until the fragment
179 	 * reassembly code can also update the flowid.
180 	 *
181 	 * Once we can calculate the flowid that way and re-establish
182 	 * a 4-tuple, flip this to 4-tuple.
183 	 */
184 	in_pcbinfo_init(&V_udbinfo, &udpcbstor, UDBHASHSIZE, UDBHASHSIZE);
185 	/* Additional pcbinfo for UDP-Lite */
186 	in_pcbinfo_init(&V_ulitecbinfo, &udplitecbstor, UDBHASHSIZE,
187 	    UDBHASHSIZE);
188 }
189 VNET_SYSINIT(udp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH,
190     udp_vnet_init, NULL);
191 
192 /*
193  * Kernel module interface for updating udpstat.  The argument is an index
194  * into udpstat treated as an array of u_long.  While this encodes the
195  * general layout of udpstat into the caller, it doesn't encode its location,
196  * so that future changes to add, for example, per-CPU stats support won't
197  * cause binary compatibility problems for kernel modules.
198  */
199 void
kmod_udpstat_inc(int statnum)200 kmod_udpstat_inc(int statnum)
201 {
202 
203 	counter_u64_add(VNET(udpstat)[statnum], 1);
204 }
205 
206 #ifdef VIMAGE
207 static void
udp_destroy(void * unused __unused)208 udp_destroy(void *unused __unused)
209 {
210 
211 	in_pcbinfo_destroy(&V_udbinfo);
212 	in_pcbinfo_destroy(&V_ulitecbinfo);
213 }
214 VNET_SYSUNINIT(udp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udp_destroy, NULL);
215 #endif
216 
217 #ifdef INET
218 /*
219  * Subroutine of udp_input(), which appends the provided mbuf chain to the
220  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
221  * contains the source address.  If the socket ends up being an IPv6 socket,
222  * udp_append() will convert to a sockaddr_in6 before passing the address
223  * into the socket code.
224  *
225  * In the normal case udp_append() will return 'false', indicating that you
226  * must unlock the inpcb.  However if a tunneling protocol is in place we
227  * increment the inpcb refcnt and unlock the inpcb, on return from the tunneling
228  * protocol we then decrement the reference count.  If in_pcbrele_rlocked()
229  * returns 'true', indicating the inpcb is gone, we return that to the caller
230  * to tell them *not* to unlock the inpcb.  In the case of multicast this will
231  * cause the distribution to stop (though most tunneling protocols known
232  * currently do *not* use multicast).
233  *
234  * The mbuf is always consumed.
235  */
236 static bool
udp_append(struct inpcb * inp,struct ip * ip,struct mbuf * n,int off,struct sockaddr_in * udp_in)237 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
238     struct sockaddr_in *udp_in)
239 {
240 	struct sockaddr *append_sa;
241 	struct socket *so;
242 	struct mbuf *tmpopts, *opts = NULL;
243 #ifdef INET6
244 	struct sockaddr_in6 udp_in6;
245 #endif
246 	struct udpcb *up;
247 
248 	INP_LOCK_ASSERT(inp);
249 
250 	/*
251 	 * Engage the tunneling protocol.
252 	 */
253 	up = intoudpcb(inp);
254 	if (up->u_tun_func != NULL) {
255 		bool filtered;
256 
257 		in_pcbref(inp);
258 		INP_RUNLOCK(inp);
259 		filtered = (*up->u_tun_func)(n, off, inp,
260 		    (struct sockaddr *)&udp_in[0], up->u_tun_ctx);
261 		INP_RLOCK(inp);
262 		if (in_pcbrele_rlocked(inp)) {
263 			if (!filtered)
264 				m_freem(n);
265 			return (true);
266 		}
267 		if (filtered)
268 			return (false);
269 	}
270 
271 	off += sizeof(struct udphdr);
272 
273 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
274 	/* Check AH/ESP integrity. */
275 	if (IPSEC_ENABLED(ipv4) &&
276 	    IPSEC_CHECK_POLICY(ipv4, n, inp) != 0) {
277 		m_freem(n);
278 		return (false);
279 	}
280 	if (up->u_flags & UF_ESPINUDP) {/* IPSec UDP encaps. */
281 		if (IPSEC_ENABLED(ipv4) &&
282 		    UDPENCAP_INPUT(ipv4, n, off, AF_INET) != 0)
283 			return (false);
284 	}
285 #endif /* IPSEC */
286 #ifdef MAC
287 	if (mac_inpcb_check_deliver(inp, n) != 0) {
288 		m_freem(n);
289 		return (false);
290 	}
291 #endif /* MAC */
292 	if (inp->inp_flags & INP_CONTROLOPTS ||
293 	    inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
294 #ifdef INET6
295 		if (inp->inp_vflag & INP_IPV6)
296 			(void)ip6_savecontrol_v4(inp, n, &opts, NULL);
297 		else
298 #endif /* INET6 */
299 			ip_savecontrol(inp, &opts, ip, n);
300 	}
301 	if ((inp->inp_vflag & INP_IPV4) && (inp->inp_flags2 & INP_ORIGDSTADDR)) {
302 		tmpopts = sbcreatecontrol(&udp_in[1],
303 		    sizeof(struct sockaddr_in), IP_ORIGDSTADDR, IPPROTO_IP,
304 		    M_NOWAIT);
305 		if (tmpopts) {
306 			if (opts) {
307 				tmpopts->m_next = opts;
308 				opts = tmpopts;
309 			} else
310 				opts = tmpopts;
311 		}
312 	}
313 #ifdef INET6
314 	if (inp->inp_vflag & INP_IPV6) {
315 		bzero(&udp_in6, sizeof(udp_in6));
316 		udp_in6.sin6_len = sizeof(udp_in6);
317 		udp_in6.sin6_family = AF_INET6;
318 		in6_sin_2_v4mapsin6(&udp_in[0], &udp_in6);
319 		append_sa = (struct sockaddr *)&udp_in6;
320 	} else
321 #endif /* INET6 */
322 		append_sa = (struct sockaddr *)&udp_in[0];
323 	m_adj(n, off);
324 
325 	so = inp->inp_socket;
326 	SOCKBUF_LOCK(&so->so_rcv);
327 	if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
328 		soroverflow_locked(so);
329 		m_freem(n);
330 		if (opts)
331 			m_freem(opts);
332 		UDPSTAT_INC(udps_fullsock);
333 	} else
334 		sorwakeup_locked(so);
335 	return (false);
336 }
337 
338 static bool
udp_multi_match(const struct inpcb * inp,void * v)339 udp_multi_match(const struct inpcb *inp, void *v)
340 {
341 	struct ip *ip = v;
342 	struct udphdr *uh = (struct udphdr *)(ip + 1);
343 
344 	if (inp->inp_lport != uh->uh_dport)
345 		return (false);
346 #ifdef INET6
347 	if ((inp->inp_vflag & INP_IPV4) == 0)
348 		return (false);
349 #endif
350 	if (inp->inp_laddr.s_addr != INADDR_ANY &&
351 	    inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
352 		return (false);
353 	if (inp->inp_faddr.s_addr != INADDR_ANY &&
354 	    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
355 		return (false);
356 	if (inp->inp_fport != 0 &&
357 	    inp->inp_fport != uh->uh_sport)
358 		return (false);
359 
360 	return (true);
361 }
362 
363 static int
udp_multi_input(struct mbuf * m,int proto,struct sockaddr_in * udp_in)364 udp_multi_input(struct mbuf *m, int proto, struct sockaddr_in *udp_in)
365 {
366 	struct ip *ip = mtod(m, struct ip *);
367 	struct inpcb_iterator inpi = INP_ITERATOR(udp_get_inpcbinfo(proto),
368 	    INPLOOKUP_RLOCKPCB, udp_multi_match, ip);
369 #ifdef KDTRACE_HOOKS
370 	struct udphdr *uh = (struct udphdr *)(ip + 1);
371 #endif
372 	struct inpcb *inp;
373 	struct mbuf *n;
374 	int appends = 0, fib;
375 
376 	MPASS(ip->ip_hl == sizeof(struct ip) >> 2);
377 
378 	fib = M_GETFIB(m);
379 
380 	while ((inp = inp_next(&inpi)) != NULL) {
381 		/*
382 		 * XXXRW: Because we weren't holding either the inpcb
383 		 * or the hash lock when we checked for a match
384 		 * before, we should probably recheck now that the
385 		 * inpcb lock is held.
386 		 */
387 
388 		if (V_udp_bind_all_fibs == 0 && fib != inp->inp_inc.inc_fibnum)
389 			/*
390 			 * Sockets bound to a specific FIB can only receive
391 			 * packets from that FIB.
392 			 */
393 			continue;
394 
395 		/*
396 		 * Handle socket delivery policy for any-source
397 		 * and source-specific multicast. [RFC3678]
398 		 */
399 		if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
400 			struct ip_moptions	*imo;
401 			struct sockaddr_in	 group;
402 			int			 blocked;
403 
404 			imo = inp->inp_moptions;
405 			if (imo == NULL)
406 				continue;
407 			bzero(&group, sizeof(struct sockaddr_in));
408 			group.sin_len = sizeof(struct sockaddr_in);
409 			group.sin_family = AF_INET;
410 			group.sin_addr = ip->ip_dst;
411 
412 			blocked = imo_multi_filter(imo, m->m_pkthdr.rcvif,
413 				(struct sockaddr *)&group,
414 				(struct sockaddr *)&udp_in[0]);
415 			if (blocked != MCAST_PASS) {
416 				if (blocked == MCAST_NOTGMEMBER)
417 					IPSTAT_INC(ips_notmember);
418 				if (blocked == MCAST_NOTSMEMBER ||
419 				    blocked == MCAST_MUTED)
420 					UDPSTAT_INC(udps_filtermcast);
421 				continue;
422 			}
423 		}
424 		if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
425 			if (proto == IPPROTO_UDPLITE)
426 				UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
427 			else
428 				UDP_PROBE(receive, NULL, inp, ip, inp, uh);
429 			if (udp_append(inp, ip, n, sizeof(struct ip), udp_in)) {
430 				break;
431 			} else
432 				appends++;
433 		}
434 		/*
435 		 * Don't look for additional matches if this one does
436 		 * not have either the SO_REUSEPORT or SO_REUSEADDR
437 		 * socket options set.  This heuristic avoids
438 		 * searching through all pcbs in the common case of a
439 		 * non-shared port.  It assumes that an application
440 		 * will never clear these options after setting them.
441 		 */
442 		if ((inp->inp_socket->so_options &
443 		    (SO_REUSEPORT|SO_REUSEPORT_LB|SO_REUSEADDR)) == 0) {
444 			INP_RUNLOCK(inp);
445 			break;
446 		}
447 	}
448 
449 	if (appends == 0) {
450 		/*
451 		 * No matching pcb found; discard datagram.  (No need
452 		 * to send an ICMP Port Unreachable for a broadcast
453 		 * or multicast datagram.)
454 		 */
455 		UDPSTAT_INC(udps_noport);
456 		if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)))
457 			UDPSTAT_INC(udps_noportmcast);
458 		else
459 			UDPSTAT_INC(udps_noportbcast);
460 	}
461 	m_freem(m);
462 
463 	return (IPPROTO_DONE);
464 }
465 
466 static int
udp_input(struct mbuf ** mp,int * offp,int proto)467 udp_input(struct mbuf **mp, int *offp, int proto)
468 {
469 	struct ip *ip;
470 	struct udphdr *uh;
471 	struct ifnet *ifp;
472 	struct inpcb *inp;
473 	uint16_t len, ip_len;
474 	struct inpcbinfo *pcbinfo;
475 	struct sockaddr_in udp_in[2];
476 	struct mbuf *m;
477 	struct m_tag *fwd_tag;
478 	int cscov_partial, iphlen, lookupflags;
479 
480 	m = *mp;
481 	iphlen = *offp;
482 	ifp = m->m_pkthdr.rcvif;
483 	*mp = NULL;
484 	UDPSTAT_INC(udps_ipackets);
485 
486 	/*
487 	 * Strip IP options, if any; should skip this, make available to
488 	 * user, and use on returned packets, but we don't yet have a way to
489 	 * check the checksum with options still present.
490 	 */
491 	if (iphlen > sizeof (struct ip)) {
492 		ip_stripoptions(m);
493 		iphlen = sizeof(struct ip);
494 	}
495 
496 	/*
497 	 * Get IP and UDP header together in first mbuf.
498 	 */
499 	if (m->m_len < iphlen + sizeof(struct udphdr)) {
500 		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) {
501 			UDPSTAT_INC(udps_hdrops);
502 			return (IPPROTO_DONE);
503 		}
504 	}
505 	ip = mtod(m, struct ip *);
506 	uh = (struct udphdr *)((caddr_t)ip + iphlen);
507 	cscov_partial = (proto == IPPROTO_UDPLITE) ? 1 : 0;
508 
509 	/*
510 	 * Destination port of 0 is illegal, based on RFC768.
511 	 */
512 	if (uh->uh_dport == 0)
513 		goto badunlocked;
514 
515 	/*
516 	 * Construct sockaddr format source address.  Stuff source address
517 	 * and datagram in user buffer.
518 	 */
519 	bzero(&udp_in[0], sizeof(struct sockaddr_in) * 2);
520 	udp_in[0].sin_len = sizeof(struct sockaddr_in);
521 	udp_in[0].sin_family = AF_INET;
522 	udp_in[0].sin_port = uh->uh_sport;
523 	udp_in[0].sin_addr = ip->ip_src;
524 	udp_in[1].sin_len = sizeof(struct sockaddr_in);
525 	udp_in[1].sin_family = AF_INET;
526 	udp_in[1].sin_port = uh->uh_dport;
527 	udp_in[1].sin_addr = ip->ip_dst;
528 
529 	/*
530 	 * Make mbuf data length reflect UDP length.  If not enough data to
531 	 * reflect UDP length, drop.
532 	 */
533 	len = ntohs((u_short)uh->uh_ulen);
534 	ip_len = ntohs(ip->ip_len) - iphlen;
535 	if (proto == IPPROTO_UDPLITE && (len == 0 || len == ip_len)) {
536 		/* Zero means checksum over the complete packet. */
537 		if (len == 0)
538 			len = ip_len;
539 		cscov_partial = 0;
540 	}
541 	if (ip_len != len) {
542 		if (len > ip_len || len < sizeof(struct udphdr)) {
543 			UDPSTAT_INC(udps_badlen);
544 			goto badunlocked;
545 		}
546 		if (proto == IPPROTO_UDP)
547 			m_adj(m, len - ip_len);
548 	}
549 
550 	/*
551 	 * Checksum extended UDP header and data.
552 	 */
553 	if (uh->uh_sum) {
554 		u_short uh_sum;
555 
556 		if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
557 		    !cscov_partial) {
558 			if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
559 				uh_sum = m->m_pkthdr.csum_data;
560 			else
561 				uh_sum = in_pseudo(ip->ip_src.s_addr,
562 				    ip->ip_dst.s_addr, htonl((u_short)len +
563 				    m->m_pkthdr.csum_data + proto));
564 			uh_sum ^= 0xffff;
565 		} else if (m->m_pkthdr.csum_flags & CSUM_IP_UDP) {
566 			/*
567 			 * Packet from local host (maybe from a VM).
568 			 * Checksum not required.
569 			 */
570 			uh_sum = 0;
571 		} else {
572 			char b[offsetof(struct ipovly, ih_src)];
573 			struct ipovly *ipov = (struct ipovly *)ip;
574 
575 			memcpy(b, ipov, sizeof(b));
576 			bzero(ipov, sizeof(ipov->ih_x1));
577 			ipov->ih_len = (proto == IPPROTO_UDP) ?
578 			    uh->uh_ulen : htons(ip_len);
579 			uh_sum = in_cksum(m, len + sizeof (struct ip));
580 			memcpy(ipov, b, sizeof(b));
581 		}
582 		if (uh_sum) {
583 			UDPSTAT_INC(udps_badsum);
584 			m_freem(m);
585 			return (IPPROTO_DONE);
586 		}
587 	} else {
588 		if (proto == IPPROTO_UDP) {
589 			UDPSTAT_INC(udps_nosum);
590 		} else {
591 			/* UDPLite requires a checksum */
592 			/* XXX: What is the right UDPLite MIB counter here? */
593 			m_freem(m);
594 			return (IPPROTO_DONE);
595 		}
596 	}
597 
598 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
599 	    in_ifnet_broadcast(ip->ip_dst, ifp))
600 		return (udp_multi_input(m, proto, udp_in));
601 
602 	pcbinfo = udp_get_inpcbinfo(proto);
603 
604 	/*
605 	 * Locate pcb for datagram.
606 	 */
607 	lookupflags = INPLOOKUP_RLOCKPCB |
608 	    (V_udp_bind_all_fibs ? 0 : INPLOOKUP_FIB);
609 
610 	/*
611 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
612 	 */
613 	if ((m->m_flags & M_IP_NEXTHOP) &&
614 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
615 		struct sockaddr_in *next_hop;
616 
617 		next_hop = (struct sockaddr_in *)(fwd_tag + 1);
618 
619 		/*
620 		 * Transparently forwarded. Pretend to be the destination.
621 		 * Already got one like this?
622 		 */
623 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
624 		    ip->ip_dst, uh->uh_dport, lookupflags, ifp, m);
625 		if (!inp) {
626 			/*
627 			 * It's new.  Try to find the ambushing socket.
628 			 * Because we've rewritten the destination address,
629 			 * any hardware-generated hash is ignored.
630 			 */
631 			inp = in_pcblookup(pcbinfo, ip->ip_src,
632 			    uh->uh_sport, next_hop->sin_addr,
633 			    next_hop->sin_port ? htons(next_hop->sin_port) :
634 			    uh->uh_dport, INPLOOKUP_WILDCARD | lookupflags,
635 			    ifp);
636 		}
637 		/* Remove the tag from the packet. We don't need it anymore. */
638 		m_tag_delete(m, fwd_tag);
639 		m->m_flags &= ~M_IP_NEXTHOP;
640 	} else
641 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
642 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
643 		    lookupflags, ifp, m);
644 	if (inp == NULL) {
645 		if (V_udp_log_in_vain) {
646 			char src[INET_ADDRSTRLEN];
647 			char dst[INET_ADDRSTRLEN];
648 
649 			log(LOG_INFO,
650 			    "Connection attempt to UDP %s:%d from %s:%d\n",
651 			    inet_ntoa_r(ip->ip_dst, dst), ntohs(uh->uh_dport),
652 			    inet_ntoa_r(ip->ip_src, src), ntohs(uh->uh_sport));
653 		}
654 		if (proto == IPPROTO_UDPLITE)
655 			UDPLITE_PROBE(receive, NULL, NULL, ip, NULL, uh);
656 		else
657 			UDP_PROBE(receive, NULL, NULL, ip, NULL, uh);
658 		UDPSTAT_INC(udps_noport);
659 		if (m->m_flags & M_MCAST) {
660 			UDPSTAT_INC(udps_noportmcast);
661 			goto badunlocked;
662 		}
663 		if (m->m_flags & M_BCAST) {
664 			UDPSTAT_INC(udps_noportbcast);
665 			goto badunlocked;
666 		}
667 		if (V_udp_blackhole && (V_udp_blackhole_local ||
668 		    !in_localip(ip->ip_src)))
669 			goto badunlocked;
670 		if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
671 			goto badunlocked;
672 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
673 		return (IPPROTO_DONE);
674 	}
675 
676 	/*
677 	 * Check the minimum TTL for socket.
678 	 */
679 	INP_RLOCK_ASSERT(inp);
680 	if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
681 		if (proto == IPPROTO_UDPLITE)
682 			UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
683 		else
684 			UDP_PROBE(receive, NULL, inp, ip, inp, uh);
685 		INP_RUNLOCK(inp);
686 		m_freem(m);
687 		return (IPPROTO_DONE);
688 	}
689 	if (cscov_partial) {
690 		struct udpcb *up;
691 
692 		up = intoudpcb(inp);
693 		if (up->u_rxcslen == 0 || up->u_rxcslen > len) {
694 			INP_RUNLOCK(inp);
695 			m_freem(m);
696 			return (IPPROTO_DONE);
697 		}
698 	}
699 
700 	if (proto == IPPROTO_UDPLITE)
701 		UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
702 	else
703 		UDP_PROBE(receive, NULL, inp, ip, inp, uh);
704 	if (!udp_append(inp, ip, m, iphlen, udp_in))
705 		INP_RUNLOCK(inp);
706 	return (IPPROTO_DONE);
707 
708 badunlocked:
709 	m_freem(m);
710 	return (IPPROTO_DONE);
711 }
712 #endif /* INET */
713 
714 /*
715  * Notify a udp user of an asynchronous error; just wake up so that they can
716  * collect error status.
717  */
718 struct inpcb *
udp_notify(struct inpcb * inp,int errno)719 udp_notify(struct inpcb *inp, int errno)
720 {
721 
722 	INP_WLOCK_ASSERT(inp);
723 	if ((errno == EHOSTUNREACH || errno == ENETUNREACH ||
724 	     errno == EHOSTDOWN) && inp->inp_route.ro_nh) {
725 		NH_FREE(inp->inp_route.ro_nh);
726 		inp->inp_route.ro_nh = (struct nhop_object *)NULL;
727 	}
728 
729 	inp->inp_socket->so_error = errno;
730 	sorwakeup(inp->inp_socket);
731 	sowwakeup(inp->inp_socket);
732 	return (inp);
733 }
734 
735 #ifdef INET
736 static void
udp_common_ctlinput(struct icmp * icmp,struct inpcbinfo * pcbinfo)737 udp_common_ctlinput(struct icmp *icmp, struct inpcbinfo *pcbinfo)
738 {
739 	struct ip *ip = &icmp->icmp_ip;
740 	struct udphdr *uh;
741 	struct inpcb *inp;
742 
743 	if (icmp_errmap(icmp) == 0)
744 		return;
745 
746 	uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
747 	inp = in_pcblookup(pcbinfo, ip->ip_dst, uh->uh_dport, ip->ip_src,
748 	    uh->uh_sport, INPLOOKUP_WLOCKPCB, NULL);
749 	if (inp != NULL) {
750 		INP_WLOCK_ASSERT(inp);
751 		if (inp->inp_socket != NULL)
752 			udp_notify(inp, icmp_errmap(icmp));
753 		INP_WUNLOCK(inp);
754 	} else {
755 		inp = in_pcblookup(pcbinfo, ip->ip_dst, uh->uh_dport,
756 		    ip->ip_src, uh->uh_sport,
757 		    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
758 		if (inp != NULL) {
759 			struct udpcb *up;
760 			udp_tun_icmp_t *func;
761 
762 			up = intoudpcb(inp);
763 			func = up->u_icmp_func;
764 			INP_RUNLOCK(inp);
765 			if (func != NULL)
766 				func(icmp);
767 		}
768 	}
769 }
770 
771 static void
udp_ctlinput(struct icmp * icmp)772 udp_ctlinput(struct icmp *icmp)
773 {
774 
775 	return (udp_common_ctlinput(icmp, &V_udbinfo));
776 }
777 
778 static void
udplite_ctlinput(struct icmp * icmp)779 udplite_ctlinput(struct icmp *icmp)
780 {
781 
782 	return (udp_common_ctlinput(icmp, &V_ulitecbinfo));
783 }
784 #endif /* INET */
785 
786 static int
udp_pcblist(SYSCTL_HANDLER_ARGS)787 udp_pcblist(SYSCTL_HANDLER_ARGS)
788 {
789 	struct inpcbinfo *pcbinfo = udp_get_inpcbinfo(arg2);
790 	struct inpcb_iterator inpi = INP_ALL_ITERATOR(pcbinfo,
791 	    INPLOOKUP_RLOCKPCB);
792 	struct xinpgen xig;
793 	struct inpcb *inp;
794 	int error;
795 
796 	if (req->newptr != 0)
797 		return (EPERM);
798 
799 	if (req->oldptr == 0) {
800 		int n;
801 
802 		n = pcbinfo->ipi_count;
803 		n += imax(n / 8, 10);
804 		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
805 		return (0);
806 	}
807 
808 	if ((error = sysctl_wire_old_buffer(req, 0)) != 0)
809 		return (error);
810 
811 	bzero(&xig, sizeof(xig));
812 	xig.xig_len = sizeof xig;
813 	xig.xig_count = pcbinfo->ipi_count;
814 	xig.xig_gen = pcbinfo->ipi_gencnt;
815 	xig.xig_sogen = so_gencnt;
816 	error = SYSCTL_OUT(req, &xig, sizeof xig);
817 	if (error)
818 		return (error);
819 
820 	while ((inp = inp_next(&inpi)) != NULL) {
821 		if (inp->inp_gencnt <= xig.xig_gen &&
822 		    cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
823 			struct xinpcb xi;
824 
825 			in_pcbtoxinpcb(inp, &xi);
826 			error = SYSCTL_OUT(req, &xi, sizeof xi);
827 			if (error) {
828 				INP_RUNLOCK(inp);
829 				break;
830 			}
831 		}
832 	}
833 
834 	if (!error) {
835 		/*
836 		 * Give the user an updated idea of our state.  If the
837 		 * generation differs from what we told her before, she knows
838 		 * that something happened while we were processing this
839 		 * request, and it might be necessary to retry.
840 		 */
841 		xig.xig_gen = pcbinfo->ipi_gencnt;
842 		xig.xig_sogen = so_gencnt;
843 		xig.xig_count = pcbinfo->ipi_count;
844 		error = SYSCTL_OUT(req, &xig, sizeof xig);
845 	}
846 
847 	return (error);
848 }
849 
850 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
851     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, IPPROTO_UDP,
852     udp_pcblist, "S,xinpcb",
853     "List of active UDP sockets");
854 
855 SYSCTL_PROC(_net_inet_udplite, OID_AUTO, pcblist,
856     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, IPPROTO_UDPLITE,
857     udp_pcblist, "S,xinpcb",
858     "List of active UDP-Lite sockets");
859 
860 #ifdef INET
861 static int
udp_getcred(SYSCTL_HANDLER_ARGS)862 udp_getcred(SYSCTL_HANDLER_ARGS)
863 {
864 	struct xucred xuc;
865 	struct sockaddr_in addrs[2];
866 	struct epoch_tracker et;
867 	struct inpcb *inp;
868 	int error;
869 
870 	if (req->newptr == NULL)
871 		return (EINVAL);
872 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
873 	if (error)
874 		return (error);
875 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
876 	if (error)
877 		return (error);
878 	NET_EPOCH_ENTER(et);
879 	inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
880 	    addrs[0].sin_addr, addrs[0].sin_port,
881 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
882 	NET_EPOCH_EXIT(et);
883 	if (inp != NULL) {
884 		INP_RLOCK_ASSERT(inp);
885 		if (inp->inp_socket == NULL)
886 			error = ENOENT;
887 		if (error == 0)
888 			error = cr_canseeinpcb(req->td->td_ucred, inp);
889 		if (error == 0)
890 			cru2x(inp->inp_cred, &xuc);
891 		INP_RUNLOCK(inp);
892 	} else
893 		error = ENOENT;
894 	if (error == 0)
895 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
896 	return (error);
897 }
898 
899 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
900     CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
901     0, 0, udp_getcred, "S,xucred",
902     "Get the xucred of a UDP connection");
903 #endif /* INET */
904 
905 int
udp_ctloutput(struct socket * so,struct sockopt * sopt)906 udp_ctloutput(struct socket *so, struct sockopt *sopt)
907 {
908 	struct inpcb *inp;
909 	struct udpcb *up;
910 	int isudplite, error, optval;
911 
912 	error = 0;
913 	isudplite = (so->so_proto->pr_protocol == IPPROTO_UDPLITE) ? 1 : 0;
914 	inp = sotoinpcb(so);
915 	KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
916 	INP_WLOCK(inp);
917 	if (sopt->sopt_level != so->so_proto->pr_protocol) {
918 #ifdef INET6
919 		if (INP_CHECK_SOCKAF(so, AF_INET6)) {
920 			INP_WUNLOCK(inp);
921 			error = ip6_ctloutput(so, sopt);
922 		}
923 #endif
924 #if defined(INET) && defined(INET6)
925 		else
926 #endif
927 #ifdef INET
928 		{
929 			INP_WUNLOCK(inp);
930 			error = ip_ctloutput(so, sopt);
931 		}
932 #endif
933 		return (error);
934 	}
935 
936 	switch (sopt->sopt_dir) {
937 	case SOPT_SET:
938 		switch (sopt->sopt_name) {
939 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
940 #if defined(INET) || defined(INET6)
941 		case UDP_ENCAP:
942 #ifdef INET
943 			if (INP_SOCKAF(so) == AF_INET) {
944 				if (!IPSEC_ENABLED(ipv4)) {
945 					INP_WUNLOCK(inp);
946 					return (ENOPROTOOPT);
947 				}
948 				error = UDPENCAP_PCBCTL(ipv4, inp, sopt);
949 				break;
950 			}
951 #endif /* INET */
952 #ifdef INET6
953 			if (INP_SOCKAF(so) == AF_INET6) {
954 				if (!IPSEC_ENABLED(ipv6)) {
955 					INP_WUNLOCK(inp);
956 					return (ENOPROTOOPT);
957 				}
958 				error = UDPENCAP_PCBCTL(ipv6, inp, sopt);
959 				break;
960 			}
961 #endif /* INET6 */
962 			INP_WUNLOCK(inp);
963 			return (EINVAL);
964 #endif /* INET || INET6 */
965 
966 #endif /* IPSEC */
967 		case UDPLITE_SEND_CSCOV:
968 		case UDPLITE_RECV_CSCOV:
969 			if (!isudplite) {
970 				INP_WUNLOCK(inp);
971 				error = ENOPROTOOPT;
972 				break;
973 			}
974 			INP_WUNLOCK(inp);
975 			error = sooptcopyin(sopt, &optval, sizeof(optval),
976 			    sizeof(optval));
977 			if (error != 0)
978 				break;
979 			inp = sotoinpcb(so);
980 			KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
981 			INP_WLOCK(inp);
982 			up = intoudpcb(inp);
983 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
984 			if ((optval != 0 && optval < 8) || (optval > 65535)) {
985 				INP_WUNLOCK(inp);
986 				error = EINVAL;
987 				break;
988 			}
989 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
990 				up->u_txcslen = optval;
991 			else
992 				up->u_rxcslen = optval;
993 			INP_WUNLOCK(inp);
994 			break;
995 		default:
996 			INP_WUNLOCK(inp);
997 			error = ENOPROTOOPT;
998 			break;
999 		}
1000 		break;
1001 	case SOPT_GET:
1002 		switch (sopt->sopt_name) {
1003 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1004 #if defined(INET) || defined(INET6)
1005 		case UDP_ENCAP:
1006 #ifdef INET
1007 			if (INP_SOCKAF(so) == AF_INET) {
1008 				if (!IPSEC_ENABLED(ipv4)) {
1009 					INP_WUNLOCK(inp);
1010 					return (ENOPROTOOPT);
1011 				}
1012 				error = UDPENCAP_PCBCTL(ipv4, inp, sopt);
1013 				break;
1014 			}
1015 #endif /* INET */
1016 #ifdef INET6
1017 			if (INP_SOCKAF(so) == AF_INET6) {
1018 				if (!IPSEC_ENABLED(ipv6)) {
1019 					INP_WUNLOCK(inp);
1020 					return (ENOPROTOOPT);
1021 				}
1022 				error = UDPENCAP_PCBCTL(ipv6, inp, sopt);
1023 				break;
1024 			}
1025 #endif /* INET6 */
1026 			INP_WUNLOCK(inp);
1027 			return (EINVAL);
1028 #endif /* INET || INET6 */
1029 
1030 #endif /* IPSEC */
1031 		case UDPLITE_SEND_CSCOV:
1032 		case UDPLITE_RECV_CSCOV:
1033 			if (!isudplite) {
1034 				INP_WUNLOCK(inp);
1035 				error = ENOPROTOOPT;
1036 				break;
1037 			}
1038 			up = intoudpcb(inp);
1039 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
1040 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1041 				optval = up->u_txcslen;
1042 			else
1043 				optval = up->u_rxcslen;
1044 			INP_WUNLOCK(inp);
1045 			error = sooptcopyout(sopt, &optval, sizeof(optval));
1046 			break;
1047 		default:
1048 			INP_WUNLOCK(inp);
1049 			error = ENOPROTOOPT;
1050 			break;
1051 		}
1052 		break;
1053 	}
1054 	return (error);
1055 }
1056 
1057 #ifdef INET
1058 #ifdef INET6
1059 /* The logic here is derived from ip6_setpktopt(). See comments there. */
1060 static int
udp_v4mapped_pktinfo(struct cmsghdr * cm,struct sockaddr_in * src,struct inpcb * inp,int flags)1061 udp_v4mapped_pktinfo(struct cmsghdr *cm, struct sockaddr_in * src,
1062     struct inpcb *inp, int flags)
1063 {
1064 	struct ifnet *ifp;
1065 	struct in6_pktinfo *pktinfo;
1066 	struct in_addr ia;
1067 
1068 	NET_EPOCH_ASSERT();
1069 
1070 	if ((flags & PRUS_IPV6) == 0)
1071 		return (0);
1072 
1073 	if (cm->cmsg_level != IPPROTO_IPV6)
1074 		return (0);
1075 
1076 	if  (cm->cmsg_type != IPV6_2292PKTINFO &&
1077 	    cm->cmsg_type != IPV6_PKTINFO)
1078 		return (0);
1079 
1080 	if (cm->cmsg_len !=
1081 	    CMSG_LEN(sizeof(struct in6_pktinfo)))
1082 		return (EINVAL);
1083 
1084 	pktinfo = (struct in6_pktinfo *)CMSG_DATA(cm);
1085 	if (!IN6_IS_ADDR_V4MAPPED(&pktinfo->ipi6_addr) &&
1086 	    !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr))
1087 		return (EINVAL);
1088 
1089 	/* Validate the interface index if specified. */
1090 	if (pktinfo->ipi6_ifindex) {
1091 		ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
1092 		if (ifp == NULL)
1093 			return (ENXIO);
1094 	} else
1095 		ifp = NULL;
1096 	if (ifp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
1097 		ia.s_addr = pktinfo->ipi6_addr.s6_addr32[3];
1098 		if (!in_ifhasaddr(ifp, ia))
1099 			return (EADDRNOTAVAIL);
1100 	}
1101 
1102 	bzero(src, sizeof(*src));
1103 	src->sin_family = AF_INET;
1104 	src->sin_len = sizeof(*src);
1105 	src->sin_port = inp->inp_lport;
1106 	src->sin_addr.s_addr = pktinfo->ipi6_addr.s6_addr32[3];
1107 
1108 	return (0);
1109 }
1110 #endif	/* INET6 */
1111 
1112 int
udp_send(struct socket * so,int flags,struct mbuf * m,struct sockaddr * addr,struct mbuf * control,struct thread * td)1113 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1114     struct mbuf *control, struct thread *td)
1115 {
1116 	struct inpcb *inp;
1117 	struct udpiphdr *ui;
1118 	int len, error = 0;
1119 	struct in_addr faddr, laddr;
1120 	struct cmsghdr *cm;
1121 	struct inpcbinfo *pcbinfo;
1122 	struct sockaddr_in *sin, src;
1123 	struct epoch_tracker et;
1124 	int cscov_partial = 0;
1125 	int ipflags = 0;
1126 	u_short fport, lport;
1127 	u_char tos, vflagsav;
1128 	uint8_t pr;
1129 	uint16_t cscov = 0;
1130 	uint32_t flowid = 0;
1131 	uint8_t flowtype = M_HASHTYPE_NONE;
1132 	bool use_cached_route;
1133 
1134 	inp = sotoinpcb(so);
1135 	KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1136 
1137 	if (addr != NULL) {
1138 		if (addr->sa_family != AF_INET)
1139 			error = EAFNOSUPPORT;
1140 		else if (addr->sa_len != sizeof(struct sockaddr_in))
1141 			error = EINVAL;
1142 		if (__predict_false(error != 0)) {
1143 			m_freem(control);
1144 			m_freem(m);
1145 			return (error);
1146 		}
1147 	}
1148 
1149 	len = m->m_pkthdr.len;
1150 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1151 		if (control)
1152 			m_freem(control);
1153 		m_freem(m);
1154 		return (EMSGSIZE);
1155 	}
1156 
1157 	src.sin_family = 0;
1158 	sin = (struct sockaddr_in *)addr;
1159 
1160 	/*
1161 	 * udp_send() may need to bind the current inpcb.  As such, we don't
1162 	 * know up front whether we will need the pcbinfo lock or not.  Do any
1163 	 * work to decide what is needed up front before acquiring any locks.
1164 	 *
1165 	 * We will need network epoch in either case, to safely lookup into
1166 	 * pcb hash.
1167 	 */
1168 	use_cached_route = sin == NULL || (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0);
1169 	if (use_cached_route || (flags & PRUS_IPV6) != 0)
1170 		INP_WLOCK(inp);
1171 	else
1172 		INP_RLOCK(inp);
1173 	NET_EPOCH_ENTER(et);
1174 #ifdef INET6
1175 	if ((flags & PRUS_IPV6) != 0) {
1176 		if ((inp->in6p_outputopts != NULL) &&
1177 		    (inp->in6p_outputopts->ip6po_tclass != -1))
1178 			tos = (u_char)inp->in6p_outputopts->ip6po_tclass;
1179 		else
1180 			tos = 0;
1181 	} else {
1182 		tos = inp->inp_ip_tos;
1183 	}
1184 #else
1185 	tos = inp->inp_ip_tos;
1186 #endif
1187 	if (control != NULL) {
1188 		/*
1189 		 * XXX: Currently, we assume all the optional information is
1190 		 * stored in a single mbuf.
1191 		 */
1192 		if (control->m_next) {
1193 			m_freem(control);
1194 			error = EINVAL;
1195 			goto release;
1196 		}
1197 		for (; control->m_len > 0;
1198 		    control->m_data += CMSG_ALIGN(cm->cmsg_len),
1199 		    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1200 			cm = mtod(control, struct cmsghdr *);
1201 			if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1202 			    || cm->cmsg_len > control->m_len) {
1203 				error = EINVAL;
1204 				break;
1205 			}
1206 #ifdef INET6
1207 			error = udp_v4mapped_pktinfo(cm, &src, inp, flags);
1208 			if (error != 0)
1209 				break;
1210 			if (((flags & PRUS_IPV6) != 0) &&
1211 			    (cm->cmsg_level == IPPROTO_IPV6) &&
1212 			    (cm->cmsg_type == IPV6_TCLASS)) {
1213 				int tclass;
1214 
1215 				if (cm->cmsg_len != CMSG_LEN(sizeof(int))) {
1216 					error = EINVAL;
1217 					break;
1218 				}
1219 				tclass = *(int *)CMSG_DATA(cm);
1220 				if (tclass < -1 || tclass > 255) {
1221 					error = EINVAL;
1222 					break;
1223 				}
1224 				if (tclass != -1)
1225 					tos = (u_char)tclass;
1226 			}
1227 #endif
1228 			if (cm->cmsg_level != IPPROTO_IP)
1229 				continue;
1230 
1231 			switch (cm->cmsg_type) {
1232 			case IP_SENDSRCADDR:
1233 				if (cm->cmsg_len !=
1234 				    CMSG_LEN(sizeof(struct in_addr))) {
1235 					error = EINVAL;
1236 					break;
1237 				}
1238 				bzero(&src, sizeof(src));
1239 				src.sin_family = AF_INET;
1240 				src.sin_len = sizeof(src);
1241 				src.sin_port = inp->inp_lport;
1242 				src.sin_addr =
1243 				    *(struct in_addr *)CMSG_DATA(cm);
1244 				break;
1245 
1246 			case IP_TOS:
1247 				if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1248 					error = EINVAL;
1249 					break;
1250 				}
1251 				tos = *(u_char *)CMSG_DATA(cm);
1252 				break;
1253 
1254 			case IP_FLOWID:
1255 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1256 					error = EINVAL;
1257 					break;
1258 				}
1259 				flowid = *(uint32_t *) CMSG_DATA(cm);
1260 				break;
1261 
1262 			case IP_FLOWTYPE:
1263 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1264 					error = EINVAL;
1265 					break;
1266 				}
1267 				flowtype = *(uint32_t *) CMSG_DATA(cm);
1268 				break;
1269 
1270 #ifdef	RSS
1271 			case IP_RSSBUCKETID:
1272 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1273 					error = EINVAL;
1274 					break;
1275 				}
1276 				/* This is just a placeholder for now */
1277 				break;
1278 #endif	/* RSS */
1279 			default:
1280 				error = ENOPROTOOPT;
1281 				break;
1282 			}
1283 			if (error)
1284 				break;
1285 		}
1286 		m_freem(control);
1287 		control = NULL;
1288 	}
1289 	if (error)
1290 		goto release;
1291 
1292 	pr = inp->inp_socket->so_proto->pr_protocol;
1293 	pcbinfo = udp_get_inpcbinfo(pr);
1294 
1295 	/*
1296 	 * If the IP_SENDSRCADDR control message was specified, override the
1297 	 * source address for this datagram.  Its use is invalidated if the
1298 	 * address thus specified is incomplete or clobbers other inpcbs.
1299 	 */
1300 	laddr = inp->inp_laddr;
1301 	lport = inp->inp_lport;
1302 	if (src.sin_family == AF_INET) {
1303 		if ((lport == 0) ||
1304 		    (laddr.s_addr == INADDR_ANY &&
1305 		     src.sin_addr.s_addr == INADDR_ANY)) {
1306 			error = EINVAL;
1307 			goto release;
1308 		}
1309 		if ((flags & PRUS_IPV6) != 0) {
1310 			vflagsav = inp->inp_vflag;
1311 			inp->inp_vflag |= INP_IPV4;
1312 			inp->inp_vflag &= ~INP_IPV6;
1313 		}
1314 		INP_HASH_WLOCK(pcbinfo);
1315 		error = in_pcbbind_setup(inp, &src, &laddr.s_addr, &lport,
1316 		    V_udp_bind_all_fibs ? 0 : INPBIND_FIB, td->td_ucred);
1317 		INP_HASH_WUNLOCK(pcbinfo);
1318 		if ((flags & PRUS_IPV6) != 0)
1319 			inp->inp_vflag = vflagsav;
1320 		if (error)
1321 			goto release;
1322 	}
1323 
1324 	/*
1325 	 * If a UDP socket has been connected, then a local address/port will
1326 	 * have been selected and bound.
1327 	 *
1328 	 * If a UDP socket has not been connected to, then an explicit
1329 	 * destination address must be used, in which case a local
1330 	 * address/port may not have been selected and bound.
1331 	 */
1332 	if (sin != NULL) {
1333 		INP_LOCK_ASSERT(inp);
1334 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1335 			error = EISCONN;
1336 			goto release;
1337 		}
1338 
1339 		/*
1340 		 * Jail may rewrite the destination address, so let it do
1341 		 * that before we use it.
1342 		 */
1343 		error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1344 		if (error)
1345 			goto release;
1346 		/*
1347 		 * sendto(2) on unconnected UDP socket results in implicit
1348 		 * binding to INADDR_ANY and anonymous port.  This has two
1349 		 * side effects:
1350 		 * 1) after first sendto(2) the socket will receive datagrams
1351 		 *    destined to the selected port.
1352 		 * 2) subsequent sendto(2) calls will use the same source port.
1353 		 */
1354 		if (inp->inp_lport == 0) {
1355 			struct sockaddr_in wild = {
1356 				.sin_family = AF_INET,
1357 				.sin_len = sizeof(struct sockaddr_in),
1358 			};
1359 
1360 			INP_HASH_WLOCK(pcbinfo);
1361 			error = in_pcbbind(inp, &wild, V_udp_bind_all_fibs ?
1362 			    0 : INPBIND_FIB, td->td_ucred);
1363 			INP_HASH_WUNLOCK(pcbinfo);
1364 			if (error)
1365 				goto release;
1366 			lport = inp->inp_lport;
1367 			laddr = inp->inp_laddr;
1368 		}
1369 		if (laddr.s_addr == INADDR_ANY) {
1370 			error = in_pcbladdr(inp, &sin->sin_addr, &laddr,
1371 			    td->td_ucred);
1372 			if (error)
1373 				goto release;
1374 		}
1375 		faddr = sin->sin_addr;
1376 		fport = sin->sin_port;
1377 	} else {
1378 		INP_LOCK_ASSERT(inp);
1379 		faddr = inp->inp_faddr;
1380 		fport = inp->inp_fport;
1381 		if (faddr.s_addr == INADDR_ANY) {
1382 			error = ENOTCONN;
1383 			goto release;
1384 		}
1385 	}
1386 
1387 	/*
1388 	 * Calculate data length and get a mbuf for UDP, IP, and possible
1389 	 * link-layer headers.  Immediate slide the data pointer back forward
1390 	 * since we won't use that space at this layer.
1391 	 */
1392 	M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1393 	if (m == NULL) {
1394 		error = ENOBUFS;
1395 		goto release;
1396 	}
1397 	m->m_data += max_linkhdr;
1398 	m->m_len -= max_linkhdr;
1399 	m->m_pkthdr.len -= max_linkhdr;
1400 
1401 	/*
1402 	 * Fill in mbuf with extended UDP header and addresses and length put
1403 	 * into network format.
1404 	 */
1405 	ui = mtod(m, struct udpiphdr *);
1406 	/*
1407 	 * Filling only those fields of udpiphdr that participate in the
1408 	 * checksum calculation. The rest must be zeroed and will be filled
1409 	 * later.
1410 	 */
1411 	bzero(ui->ui_x1, sizeof(ui->ui_x1));
1412 	ui->ui_pr = pr;
1413 	ui->ui_src = laddr;
1414 	ui->ui_dst = faddr;
1415 	ui->ui_sport = lport;
1416 	ui->ui_dport = fport;
1417 	ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1418 	if (pr == IPPROTO_UDPLITE) {
1419 		struct udpcb *up;
1420 		uint16_t plen;
1421 
1422 		up = intoudpcb(inp);
1423 		cscov = up->u_txcslen;
1424 		plen = (u_short)len + sizeof(struct udphdr);
1425 		if (cscov >= plen)
1426 			cscov = 0;
1427 		ui->ui_len = htons(plen);
1428 		ui->ui_ulen = htons(cscov);
1429 		/*
1430 		 * For UDP-Lite, checksum coverage length of zero means
1431 		 * the entire UDPLite packet is covered by the checksum.
1432 		 */
1433 		cscov_partial = (cscov == 0) ? 0 : 1;
1434 	}
1435 
1436 	if (inp->inp_socket->so_options & SO_DONTROUTE)
1437 		ipflags |= IP_ROUTETOIF;
1438 	if (inp->inp_socket->so_options & SO_BROADCAST)
1439 		ipflags |= IP_ALLOWBROADCAST;
1440 	if (inp->inp_flags & INP_ONESBCAST)
1441 		ipflags |= IP_SENDONES;
1442 
1443 #ifdef MAC
1444 	mac_inpcb_create_mbuf(inp, m);
1445 #endif
1446 
1447 	/*
1448 	 * Set up checksum and output datagram.
1449 	 */
1450 	ui->ui_sum = 0;
1451 	if (pr == IPPROTO_UDPLITE) {
1452 		if (inp->inp_flags & INP_ONESBCAST)
1453 			faddr.s_addr = INADDR_BROADCAST;
1454 		if (cscov_partial) {
1455 			if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
1456 				ui->ui_sum = 0xffff;
1457 		} else {
1458 			if ((ui->ui_sum = in_cksum(m, sizeof(struct udpiphdr) + len)) == 0)
1459 				ui->ui_sum = 0xffff;
1460 		}
1461 	} else if (V_udp_cksum) {
1462 		if (inp->inp_flags & INP_ONESBCAST)
1463 			faddr.s_addr = INADDR_BROADCAST;
1464 		ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1465 		    htons((u_short)len + sizeof(struct udphdr) + pr));
1466 		m->m_pkthdr.csum_flags = CSUM_UDP;
1467 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1468 	}
1469 	/*
1470 	 * After finishing the checksum computation, fill the remaining fields
1471 	 * of udpiphdr.
1472 	 */
1473 	((struct ip *)ui)->ip_v = IPVERSION;
1474 	((struct ip *)ui)->ip_tos = tos;
1475 	((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1476 	if (inp->inp_flags & INP_DONTFRAG)
1477 		((struct ip *)ui)->ip_off |= htons(IP_DF);
1478 	((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;
1479 	UDPSTAT_INC(udps_opackets);
1480 
1481 	/*
1482 	 * Setup flowid / RSS information for outbound socket.
1483 	 *
1484 	 * Once the UDP code decides to set a flowid some other way,
1485 	 * this allows the flowid to be overridden by userland.
1486 	 */
1487 	if (flowtype != M_HASHTYPE_NONE) {
1488 		m->m_pkthdr.flowid = flowid;
1489 		M_HASHTYPE_SET(m, flowtype);
1490 	}
1491 #if defined(ROUTE_MPATH) || defined(RSS)
1492 	else if (CALC_FLOWID_OUTBOUND_SENDTO) {
1493 		uint32_t hash_val, hash_type;
1494 
1495 		hash_val = fib4_calc_packet_hash(laddr, faddr,
1496 		    lport, fport, pr, &hash_type);
1497 		m->m_pkthdr.flowid = hash_val;
1498 		M_HASHTYPE_SET(m, hash_type);
1499 	}
1500 
1501 	/*
1502 	 * Don't override with the inp cached flowid value.
1503 	 *
1504 	 * Depending upon the kind of send being done, the inp
1505 	 * flowid/flowtype values may actually not be appropriate
1506 	 * for this particular socket send.
1507 	 *
1508 	 * We should either leave the flowid at zero (which is what is
1509 	 * currently done) or set it to some software generated
1510 	 * hash value based on the packet contents.
1511 	 */
1512 	ipflags |= IP_NODEFAULTFLOWID;
1513 #endif	/* RSS */
1514 
1515 	if (pr == IPPROTO_UDPLITE)
1516 		UDPLITE_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1517 	else
1518 		UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1519 	error = ip_output(m, inp->inp_options,
1520 	    use_cached_route ? &inp->inp_route : NULL, ipflags,
1521 	    inp->inp_moptions, inp);
1522 	INP_UNLOCK(inp);
1523 	NET_EPOCH_EXIT(et);
1524 	return (error);
1525 
1526 release:
1527 	INP_UNLOCK(inp);
1528 	NET_EPOCH_EXIT(et);
1529 	m_freem(m);
1530 	return (error);
1531 }
1532 
1533 void
udp_abort(struct socket * so)1534 udp_abort(struct socket *so)
1535 {
1536 	struct inpcb *inp;
1537 	struct inpcbinfo *pcbinfo;
1538 
1539 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1540 	inp = sotoinpcb(so);
1541 	KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1542 	INP_WLOCK(inp);
1543 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1544 		INP_HASH_WLOCK(pcbinfo);
1545 		in_pcbdisconnect(inp);
1546 		INP_HASH_WUNLOCK(pcbinfo);
1547 		soisdisconnected(so);
1548 	}
1549 	INP_WUNLOCK(inp);
1550 }
1551 
1552 static int
udp_attach(struct socket * so,int proto,struct thread * td)1553 udp_attach(struct socket *so, int proto, struct thread *td)
1554 {
1555 	static uint32_t udp_flowid;
1556 	struct inpcbinfo *pcbinfo;
1557 	struct inpcb *inp;
1558 	struct udpcb *up;
1559 	int error;
1560 
1561 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1562 	inp = sotoinpcb(so);
1563 	KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1564 	error = soreserve(so, udp_sendspace, udp_recvspace);
1565 	if (error)
1566 		return (error);
1567 	error = in_pcballoc(so, pcbinfo);
1568 	if (error)
1569 		return (error);
1570 
1571 	inp = sotoinpcb(so);
1572 	inp->inp_ip_ttl = V_ip_defttl;
1573 	inp->inp_flowid = atomic_fetchadd_int(&udp_flowid, 1);
1574 	inp->inp_flowtype = M_HASHTYPE_OPAQUE;
1575 	up = intoudpcb(inp);
1576 	bzero(&up->u_start_zero, u_zero_size);
1577 	INP_WUNLOCK(inp);
1578 
1579 	return (0);
1580 }
1581 #endif /* INET */
1582 
1583 int
udp_set_kernel_tunneling(struct socket * so,udp_tun_func_t f,udp_tun_icmp_t i,void * ctx)1584 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f, udp_tun_icmp_t i, void *ctx)
1585 {
1586 	struct inpcb *inp;
1587 	struct udpcb *up;
1588 
1589 	KASSERT(so->so_type == SOCK_DGRAM,
1590 	    ("udp_set_kernel_tunneling: !dgram"));
1591 	inp = sotoinpcb(so);
1592 	KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1593 	INP_WLOCK(inp);
1594 	up = intoudpcb(inp);
1595 	if ((f != NULL || i != NULL) && ((up->u_tun_func != NULL) ||
1596 	    (up->u_icmp_func != NULL))) {
1597 		INP_WUNLOCK(inp);
1598 		return (EBUSY);
1599 	}
1600 	up->u_tun_func = f;
1601 	up->u_icmp_func = i;
1602 	up->u_tun_ctx = ctx;
1603 	INP_WUNLOCK(inp);
1604 	return (0);
1605 }
1606 
1607 #ifdef INET
1608 static int
udp_bind(struct socket * so,struct sockaddr * nam,struct thread * td)1609 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1610 {
1611 	struct inpcb *inp;
1612 	struct inpcbinfo *pcbinfo;
1613 	struct sockaddr_in *sinp;
1614 	int error;
1615 
1616 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1617 	inp = sotoinpcb(so);
1618 	KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1619 
1620 	sinp = (struct sockaddr_in *)nam;
1621 	if (nam->sa_family != AF_INET) {
1622 		/*
1623 		 * Preserve compatibility with old programs.
1624 		 */
1625 		if (nam->sa_family != AF_UNSPEC ||
1626 		    nam->sa_len < offsetof(struct sockaddr_in, sin_zero) ||
1627 		    sinp->sin_addr.s_addr != INADDR_ANY)
1628 			return (EAFNOSUPPORT);
1629 		nam->sa_family = AF_INET;
1630 	}
1631 	if (nam->sa_len != sizeof(struct sockaddr_in))
1632 		return (EINVAL);
1633 
1634 	INP_WLOCK(inp);
1635 	INP_HASH_WLOCK(pcbinfo);
1636 	error = in_pcbbind(inp, sinp, V_udp_bind_all_fibs ? 0 : INPBIND_FIB,
1637 	    td->td_ucred);
1638 	INP_HASH_WUNLOCK(pcbinfo);
1639 	INP_WUNLOCK(inp);
1640 	return (error);
1641 }
1642 
1643 static void
udp_close(struct socket * so)1644 udp_close(struct socket *so)
1645 {
1646 	struct inpcb *inp;
1647 	struct inpcbinfo *pcbinfo;
1648 
1649 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1650 	inp = sotoinpcb(so);
1651 	KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1652 	INP_WLOCK(inp);
1653 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1654 		INP_HASH_WLOCK(pcbinfo);
1655 		in_pcbdisconnect(inp);
1656 		INP_HASH_WUNLOCK(pcbinfo);
1657 		soisdisconnected(so);
1658 	}
1659 	INP_WUNLOCK(inp);
1660 }
1661 
1662 static int
udp_connect(struct socket * so,struct sockaddr * nam,struct thread * td)1663 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1664 {
1665 	struct epoch_tracker et;
1666 	struct inpcb *inp;
1667 	struct inpcbinfo *pcbinfo;
1668 	struct sockaddr_in *sin;
1669 	int error;
1670 
1671 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1672 	inp = sotoinpcb(so);
1673 	KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1674 
1675 	sin = (struct sockaddr_in *)nam;
1676 	if (sin->sin_family != AF_INET)
1677 		return (EAFNOSUPPORT);
1678 	if (sin->sin_len != sizeof(*sin))
1679 		return (EINVAL);
1680 
1681 	INP_WLOCK(inp);
1682 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1683 		INP_WUNLOCK(inp);
1684 		return (EISCONN);
1685 	}
1686 	error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1687 	if (error != 0) {
1688 		INP_WUNLOCK(inp);
1689 		return (error);
1690 	}
1691 	NET_EPOCH_ENTER(et);
1692 	INP_HASH_WLOCK(pcbinfo);
1693 	error = in_pcbconnect(inp, sin, td->td_ucred);
1694 	INP_HASH_WUNLOCK(pcbinfo);
1695 	NET_EPOCH_EXIT(et);
1696 	if (error == 0)
1697 		soisconnected(so);
1698 	INP_WUNLOCK(inp);
1699 	return (error);
1700 }
1701 
1702 static void
udp_detach(struct socket * so)1703 udp_detach(struct socket *so)
1704 {
1705 	struct inpcb *inp;
1706 
1707 	inp = sotoinpcb(so);
1708 	KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1709 	KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1710 	    ("udp_detach: not disconnected"));
1711 	INP_WLOCK(inp);
1712 	in_pcbfree(inp);
1713 }
1714 
1715 int
udp_disconnect(struct socket * so)1716 udp_disconnect(struct socket *so)
1717 {
1718 	struct inpcb *inp;
1719 	struct inpcbinfo *pcbinfo;
1720 
1721 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1722 	inp = sotoinpcb(so);
1723 	KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1724 	INP_WLOCK(inp);
1725 	if (inp->inp_faddr.s_addr == INADDR_ANY) {
1726 		INP_WUNLOCK(inp);
1727 		return (ENOTCONN);
1728 	}
1729 	INP_HASH_WLOCK(pcbinfo);
1730 	in_pcbdisconnect(inp);
1731 	INP_HASH_WUNLOCK(pcbinfo);
1732 	SOCK_LOCK(so);
1733 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1734 	SOCK_UNLOCK(so);
1735 	INP_WUNLOCK(inp);
1736 	return (0);
1737 }
1738 #endif /* INET */
1739 
1740 int
udp_shutdown(struct socket * so,enum shutdown_how how)1741 udp_shutdown(struct socket *so, enum shutdown_how how)
1742 {
1743 	int error;
1744 
1745 	SOCK_LOCK(so);
1746 	if (!(so->so_state & SS_ISCONNECTED))
1747 		/*
1748 		 * POSIX mandates us to just return ENOTCONN when shutdown(2) is
1749 		 * invoked on a datagram sockets, however historically we would
1750 		 * actually tear socket down.  This is known to be leveraged by
1751 		 * some applications to unblock process waiting in recv(2) by
1752 		 * other process that it shares that socket with.  Try to meet
1753 		 * both backward-compatibility and POSIX requirements by forcing
1754 		 * ENOTCONN but still flushing buffers and performing wakeup(9).
1755 		 *
1756 		 * XXXGL: it remains unknown what applications expect this
1757 		 * behavior and is this isolated to unix/dgram or inet/dgram or
1758 		 * both.  See: D10351, D3039.
1759 		 */
1760 		error = ENOTCONN;
1761 	else
1762 		error = 0;
1763 	SOCK_UNLOCK(so);
1764 
1765 	switch (how) {
1766 	case SHUT_RD:
1767 		sorflush(so);
1768 		break;
1769 	case SHUT_RDWR:
1770 		sorflush(so);
1771 		/* FALLTHROUGH */
1772 	case SHUT_WR:
1773 		socantsendmore(so);
1774 	}
1775 
1776 	return (error);
1777 }
1778 
1779 #ifdef INET
1780 #define	UDP_PROTOSW							\
1781 	.pr_type =		SOCK_DGRAM,				\
1782 	.pr_flags =		PR_ATOMIC | PR_ADDR | PR_CAPATTACH,	\
1783 	.pr_ctloutput =		udp_ctloutput,				\
1784 	.pr_abort =		udp_abort,				\
1785 	.pr_attach =		udp_attach,				\
1786 	.pr_bind =		udp_bind,				\
1787 	.pr_connect =		udp_connect,				\
1788 	.pr_control =		in_control,				\
1789 	.pr_detach =		udp_detach,				\
1790 	.pr_disconnect =	udp_disconnect,				\
1791 	.pr_peeraddr =		in_getpeeraddr,				\
1792 	.pr_send =		udp_send,				\
1793 	.pr_soreceive =		soreceive_dgram,			\
1794 	.pr_sosend =		sosend_dgram,				\
1795 	.pr_shutdown =		udp_shutdown,				\
1796 	.pr_sockaddr =		in_getsockaddr,				\
1797 	.pr_sosetlabel =	in_pcbsosetlabel,			\
1798 	.pr_close =		udp_close
1799 
1800 struct protosw udp_protosw = {
1801 	.pr_protocol =		IPPROTO_UDP,
1802 	UDP_PROTOSW
1803 };
1804 
1805 struct protosw udplite_protosw = {
1806 	.pr_protocol =		IPPROTO_UDPLITE,
1807 	UDP_PROTOSW
1808 };
1809 
1810 static void
udp_init(void * arg __unused)1811 udp_init(void *arg __unused)
1812 {
1813 
1814 	IPPROTO_REGISTER(IPPROTO_UDP, udp_input, udp_ctlinput);
1815 	IPPROTO_REGISTER(IPPROTO_UDPLITE, udp_input, udplite_ctlinput);
1816 }
1817 SYSINIT(udp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, udp_init, NULL);
1818 #endif /* INET */
1819