xref: /xnu-11417.140.69/bsd/netinet6/in6_pcb.c (revision 43a90889846e00bfb5cf1d255cdc0a701a1e05a4)
1 /*
2  * Copyright (c) 2003-2021 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /*
29  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
30  * All rights reserved.
31  *
32  * Redistribution and use in source and binary forms, with or without
33  * modification, are permitted provided that the following conditions
34  * are met:
35  * 1. Redistributions of source code must retain the above copyright
36  *    notice, this list of conditions and the following disclaimer.
37  * 2. Redistributions in binary form must reproduce the above copyright
38  *    notice, this list of conditions and the following disclaimer in the
39  *    documentation and/or other materials provided with the distribution.
40  * 3. Neither the name of the project nor the names of its contributors
41  *    may be used to endorse or promote products derived from this software
42  *    without specific prior written permission.
43  *
44  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
54  * SUCH DAMAGE.
55  *
56  */
57 
58 /*
59  * Copyright (c) 1982, 1986, 1991, 1993
60  *	The Regents of the University of California.  All rights reserved.
61  *
62  * Redistribution and use in source and binary forms, with or without
63  * modification, are permitted provided that the following conditions
64  * are met:
65  * 1. Redistributions of source code must retain the above copyright
66  *    notice, this list of conditions and the following disclaimer.
67  * 2. Redistributions in binary form must reproduce the above copyright
68  *    notice, this list of conditions and the following disclaimer in the
69  *    documentation and/or other materials provided with the distribution.
70  * 3. All advertising materials mentioning features or use of this software
71  *    must display the following acknowledgement:
72  *	This product includes software developed by the University of
73  *	California, Berkeley and its contributors.
74  * 4. Neither the name of the University nor the names of its contributors
75  *    may be used to endorse or promote products derived from this software
76  *    without specific prior written permission.
77  *
78  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
79  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
80  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
81  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
82  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
83  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
84  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
85  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
86  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
87  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
88  * SUCH DAMAGE.
89  *
90  *	@(#)in_pcb.c	8.2 (Berkeley) 1/4/94
91  */
92 
93 #include <sys/param.h>
94 #include <sys/systm.h>
95 #include <sys/malloc.h>
96 #include <sys/mbuf.h>
97 #include <sys/domain.h>
98 #include <sys/protosw.h>
99 #include <sys/socket.h>
100 #include <sys/socketvar.h>
101 #include <sys/sockio.h>
102 #include <sys/errno.h>
103 #include <sys/time.h>
104 #include <sys/proc.h>
105 #include <sys/kauth.h>
106 #include <sys/priv.h>
107 
108 #include <net/if.h>
109 #include <net/if_types.h>
110 #include <net/route.h>
111 #include <net/ntstat.h>
112 #include <net/restricted_in_port.h>
113 
114 #include <netinet/in.h>
115 #include <netinet/in_var.h>
116 #include <netinet/in_systm.h>
117 #include <netinet/ip6.h>
118 #include <netinet/ip_var.h>
119 
120 #include <netinet6/ip6_var.h>
121 #include <netinet6/nd6.h>
122 #include <netinet/in_pcb.h>
123 #include <netinet6/in6_pcb.h>
124 
125 #include <net/if_types.h>
126 #include <net/if_var.h>
127 
128 #include <kern/kern_types.h>
129 #include <kern/zalloc.h>
130 
131 #if IPSEC
132 #include <netinet6/ipsec.h>
133 #include <netinet6/ipsec6.h>
134 #include <netinet6/ah.h>
135 #include <netinet6/ah6.h>
136 #include <netkey/key.h>
137 #endif /* IPSEC */
138 
139 #if NECP
140 #include <net/necp.h>
141 #endif /* NECP */
142 
143 #include <net/sockaddr_utils.h>
144 
145 /*
146  * in6_pcblookup_local_and_cleanup does everything
147  * in6_pcblookup_local does but it checks for a socket
148  * that's going away. Since we know that the lock is
149  * held read+write when this function is called, we
150  * can safely dispose of this socket like the slow
151  * timer would usually do and return NULL. This is
152  * great for bind.
153  */
154 static struct inpcb *
in6_pcblookup_local_and_cleanup(struct inpcbinfo * pcbinfo,struct in6_addr * laddr,u_int lport_arg,uint32_t ifscope,int wild_okay)155 in6_pcblookup_local_and_cleanup(struct inpcbinfo *pcbinfo,
156     struct in6_addr *laddr, u_int lport_arg, uint32_t ifscope, int wild_okay)
157 {
158 	struct inpcb *__single inp;
159 
160 	/* Perform normal lookup */
161 	inp = in6_pcblookup_local(pcbinfo, laddr, lport_arg, ifscope, wild_okay);
162 
163 	/* Check if we found a match but it's waiting to be disposed */
164 	if (inp != NULL && inp->inp_wantcnt == WNT_STOPUSING) {
165 		struct socket *so = inp->inp_socket;
166 
167 		socket_lock(so, 0);
168 
169 		if (so->so_usecount == 0) {
170 			if (inp->inp_state != INPCB_STATE_DEAD) {
171 				in6_pcbdetach(inp);
172 			}
173 			in_pcbdispose(inp);     /* will unlock & destroy */
174 			inp = NULL;
175 		} else {
176 			socket_unlock(so, 0);
177 		}
178 	}
179 
180 	return inp;
181 }
182 
183 /*
184  * Bind an INPCB to an address and/or port.  This routine should not alter
185  * the caller-supplied local address "nam" or remote address "remote".
186  */
187 int
in6_pcbbind(struct inpcb * inp,struct sockaddr * nam,struct sockaddr * remote,struct proc * p)188 in6_pcbbind(struct inpcb *inp, struct sockaddr *nam, struct sockaddr *remote, struct proc *p)
189 {
190 	struct socket *__single so = inp->inp_socket;
191 	struct inpcbinfo *__single pcbinfo = inp->inp_pcbinfo;
192 	u_short lport = 0;
193 	int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);
194 	ifnet_ref_t outif = NULL;
195 	struct sockaddr_in6 sin6;
196 	uint32_t lifscope = IFSCOPE_NONE;
197 	int error = 0;
198 #if XNU_TARGET_OS_OSX
199 	kauth_cred_t __single cred;
200 #endif /* XNU_TARGET_OS_OSX */
201 
202 	ASSERT((inp->inp_flags2 & INP2_BIND_IN_PROGRESS) != 0);
203 
204 	if (TAILQ_EMPTY(&in6_ifaddrhead)) { /* XXX broken! */
205 		error = EADDRNOTAVAIL;
206 		goto done;
207 	}
208 	if (!(so->so_options & (SO_REUSEADDR | SO_REUSEPORT))) {
209 		wild = 1;
210 	}
211 
212 	in_pcb_check_management_entitled(inp);
213 	in_pcb_check_ultra_constrained_entitled(inp);
214 
215 	socket_unlock(so, 0); /* keep reference */
216 	lck_rw_lock_exclusive(&pcbinfo->ipi_lock);
217 	if (inp->inp_lport || !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
218 		/* another thread completed the bind */
219 		lck_rw_done(&pcbinfo->ipi_lock);
220 		socket_lock(so, 0);
221 		error = EINVAL;
222 		goto done;
223 	}
224 
225 	SOCKADDR_ZERO(&sin6, sizeof(sin6));
226 	if (nam != NULL) {
227 		if (nam->sa_len != sizeof(struct sockaddr_in6)) {
228 			lck_rw_done(&pcbinfo->ipi_lock);
229 			socket_lock(so, 0);
230 			error = EINVAL;
231 			goto done;
232 		}
233 		/*
234 		 * family check.
235 		 */
236 		if (nam->sa_family != AF_INET6) {
237 			lck_rw_done(&pcbinfo->ipi_lock);
238 			socket_lock(so, 0);
239 			error = EAFNOSUPPORT;
240 			goto done;
241 		}
242 		lport = SIN6(nam)->sin6_port;
243 
244 		*(&sin6) = *SIN6(nam);
245 
246 		/* KAME hack: embed scopeid */
247 		if (in6_embedscope(&sin6.sin6_addr, &sin6, inp, NULL,
248 		    NULL, &lifscope) != 0) {
249 			lck_rw_done(&pcbinfo->ipi_lock);
250 			socket_lock(so, 0);
251 			error = EINVAL;
252 			goto done;
253 		}
254 
255 		/* Sanitize local copy for address searches */
256 		sin6.sin6_flowinfo = 0;
257 		sin6.sin6_port = 0;
258 		if (in6_embedded_scope) {
259 			sin6.sin6_scope_id = 0;
260 		}
261 
262 		if (IN6_IS_ADDR_MULTICAST(&sin6.sin6_addr)) {
263 			/*
264 			 * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
265 			 * allow compepte duplication of binding if
266 			 * SO_REUSEPORT is set, or if SO_REUSEADDR is set
267 			 * and a multicast address is bound on both
268 			 * new and duplicated sockets.
269 			 */
270 			if (so->so_options & SO_REUSEADDR) {
271 				reuseport = SO_REUSEADDR | SO_REUSEPORT;
272 			}
273 		} else if (!IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr)) {
274 			struct ifaddr *__single ifa;
275 
276 			ifa = ifa_ifwithaddr(SA(&sin6));
277 			if (ifa == NULL) {
278 				lck_rw_done(&pcbinfo->ipi_lock);
279 				socket_lock(so, 0);
280 				error = EADDRNOTAVAIL;
281 				goto done;
282 			} else {
283 				/*
284 				 * XXX: bind to an anycast address might
285 				 * accidentally cause sending a packet with
286 				 * anycast source address.  We should allow
287 				 * to bind to a deprecated address, since
288 				 * the application dare to use it.
289 				 */
290 				IFA_LOCK_SPIN(ifa);
291 				if ((ifatoia6(ifa))->ia6_flags &
292 				    (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY |
293 				    IN6_IFF_DETACHED | IN6_IFF_CLAT46)) {
294 					IFA_UNLOCK(ifa);
295 					ifa_remref(ifa);
296 					lck_rw_done(&pcbinfo->ipi_lock);
297 					socket_lock(so, 0);
298 					error = EADDRNOTAVAIL;
299 					goto done;
300 				}
301 				/*
302 				 * Opportunistically determine the outbound
303 				 * interface that may be used; this may not
304 				 * hold true if we end up using a route
305 				 * going over a different interface, e.g.
306 				 * when sending to a local address.  This
307 				 * will get updated again after sending.
308 				 */
309 				outif = ifa->ifa_ifp;
310 				IFA_UNLOCK(ifa);
311 				ifa_remref(ifa);
312 			}
313 		}
314 
315 #if SKYWALK
316 		if (inp->inp_flags2 & INP2_EXTERNAL_PORT) {
317 			// Extract the external flow info
318 			struct ns_flow_info nfi = {};
319 			int netns_error = necp_client_get_netns_flow_info(inp->necp_client_uuid,
320 			    &nfi);
321 			if (netns_error != 0) {
322 				lck_rw_done(&pcbinfo->ipi_lock);
323 				socket_lock(so, 0);
324 				error = netns_error;
325 				goto done;
326 			}
327 
328 			// Extract the reserved port
329 			u_int16_t reserved_lport = 0;
330 			if (nfi.nfi_laddr.sa.sa_family == AF_INET) {
331 				reserved_lport = nfi.nfi_laddr.sin.sin_port;
332 			} else if (nfi.nfi_laddr.sa.sa_family == AF_INET6) {
333 				reserved_lport = nfi.nfi_laddr.sin6.sin6_port;
334 			} else {
335 				lck_rw_done(&pcbinfo->ipi_lock);
336 				socket_lock(so, 0);
337 				error = EINVAL;
338 				goto done;
339 			}
340 
341 			// Validate or use the reserved port
342 			if (lport == 0) {
343 				lport = reserved_lport;
344 			} else if (lport != reserved_lport) {
345 				lck_rw_done(&pcbinfo->ipi_lock);
346 				socket_lock(so, 0);
347 				error = EINVAL;
348 				goto done;
349 			}
350 		}
351 
352 		/* Do not allow reserving a UDP port if remaining UDP port count is below 4096 */
353 		if (SOCK_PROTO(so) == IPPROTO_UDP && !allow_udp_port_exhaustion) {
354 			uint32_t current_reservations = 0;
355 			current_reservations = netns_lookup_reservations_count_in6(inp->in6p_laddr, IPPROTO_UDP);
356 			if (USHRT_MAX - UDP_RANDOM_PORT_RESERVE < current_reservations) {
357 				log(LOG_ERR, "UDP port not available, less than 4096 UDP ports left");
358 				lck_rw_done(&pcbinfo->ipi_lock);
359 				socket_lock(so, 0);
360 				error = EADDRNOTAVAIL;
361 				goto done;
362 			}
363 		}
364 
365 #endif /* SKYWALK */
366 
367 		if (lport != 0) {
368 			struct inpcb *__single t;
369 			uid_t u;
370 
371 #if XNU_TARGET_OS_OSX
372 			if (ntohs(lport) < IPV6PORT_RESERVED &&
373 			    !IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr) &&
374 			    !(inp->inp_flags2 & INP2_EXTERNAL_PORT)) {
375 				cred = kauth_cred_proc_ref(p);
376 				error = priv_check_cred(cred,
377 				    PRIV_NETINET_RESERVEDPORT, 0);
378 				kauth_cred_unref(&cred);
379 				if (error != 0) {
380 					lck_rw_done(&pcbinfo->ipi_lock);
381 					socket_lock(so, 0);
382 					error = EACCES;
383 					goto done;
384 				}
385 			}
386 #endif /* XNU_TARGET_OS_OSX */
387 			/*
388 			 * Check wether the process is allowed to bind to a restricted port
389 			 */
390 			if (!current_task_can_use_restricted_in_port(lport,
391 			    (uint8_t)SOCK_PROTO(so), PORT_FLAGS_BSD)) {
392 				lck_rw_done(&pcbinfo->ipi_lock);
393 				socket_lock(so, 0);
394 				error = EADDRINUSE;
395 				goto done;
396 			}
397 
398 			if (!IN6_IS_ADDR_MULTICAST(&sin6.sin6_addr) &&
399 			    (u = kauth_cred_getuid(so->so_cred)) != 0) {
400 				t = in6_pcblookup_local_and_cleanup(pcbinfo,
401 				    &sin6.sin6_addr, lport, sin6.sin6_scope_id,
402 				    INPLOOKUP_WILDCARD);
403 				if (t != NULL &&
404 				    (!IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr) ||
405 				    !IN6_IS_ADDR_UNSPECIFIED(&t->in6p_laddr) ||
406 				    !(t->inp_socket->so_options & SO_REUSEPORT)) &&
407 				    (u != kauth_cred_getuid(t->inp_socket->so_cred)) &&
408 				    !(t->inp_socket->so_flags & SOF_REUSESHAREUID) &&
409 				    (!(t->inp_flags2 & INP2_EXTERNAL_PORT) ||
410 				    !(inp->inp_flags2 & INP2_EXTERNAL_PORT) ||
411 				    uuid_compare(t->necp_client_uuid, inp->necp_client_uuid) != 0)) {
412 					lck_rw_done(&pcbinfo->ipi_lock);
413 					socket_lock(so, 0);
414 					error = EADDRINUSE;
415 					goto done;
416 				}
417 				if (!(inp->inp_flags & IN6P_IPV6_V6ONLY) &&
418 				    IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr)) {
419 					struct sockaddr_in sin;
420 
421 					in6_sin6_2_sin(&sin, &sin6);
422 					t = in_pcblookup_local_and_cleanup(
423 						pcbinfo, sin.sin_addr, lport,
424 						INPLOOKUP_WILDCARD);
425 					if (t != NULL &&
426 					    !(t->inp_socket->so_options & SO_REUSEPORT) &&
427 					    (kauth_cred_getuid(so->so_cred) !=
428 					    kauth_cred_getuid(t->inp_socket->so_cred)) &&
429 					    (t->inp_laddr.s_addr != INADDR_ANY ||
430 					    SOCK_DOM(so) == SOCK_DOM(t->inp_socket)) &&
431 					    (!(t->inp_flags2 & INP2_EXTERNAL_PORT) ||
432 					    !(inp->inp_flags2 & INP2_EXTERNAL_PORT) ||
433 					    uuid_compare(t->necp_client_uuid, inp->necp_client_uuid) != 0)) {
434 						lck_rw_done(&pcbinfo->ipi_lock);
435 						socket_lock(so, 0);
436 						error = EADDRINUSE;
437 						goto done;
438 					}
439 
440 #if SKYWALK
441 					VERIFY(!NETNS_TOKEN_VALID(
442 						    &inp->inp_wildcard_netns_token));
443 					if ((SOCK_PROTO(so) == IPPROTO_TCP ||
444 					    SOCK_PROTO(so) == IPPROTO_UDP) &&
445 					    !(inp->inp_flags2 & INP2_EXTERNAL_PORT)) {
446 						if (netns_reserve_in(&inp->
447 						    inp_wildcard_netns_token,
448 						    sin.sin_addr,
449 						    (uint8_t)SOCK_PROTO(so), lport,
450 						    NETNS_BSD, NULL) != 0) {
451 							lck_rw_done(&pcbinfo->ipi_lock);
452 							socket_lock(so, 0);
453 							error = EADDRINUSE;
454 							goto done;
455 						}
456 					}
457 #endif /* SKYWALK */
458 				}
459 			}
460 			t = in6_pcblookup_local_and_cleanup(pcbinfo,
461 			    &sin6.sin6_addr, lport, sin6.sin6_scope_id, wild);
462 			if (t != NULL &&
463 			    (reuseport & t->inp_socket->so_options) == 0 &&
464 			    (!(t->inp_flags2 & INP2_EXTERNAL_PORT) ||
465 			    !(inp->inp_flags2 & INP2_EXTERNAL_PORT) ||
466 			    uuid_compare(t->necp_client_uuid, inp->necp_client_uuid) != 0)) {
467 #if SKYWALK
468 				netns_release(&inp->inp_wildcard_netns_token);
469 #endif /* SKYWALK */
470 				lck_rw_done(&pcbinfo->ipi_lock);
471 				socket_lock(so, 0);
472 				error = EADDRINUSE;
473 				goto done;
474 			}
475 			if (!(inp->inp_flags & IN6P_IPV6_V6ONLY) &&
476 			    IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr)) {
477 				struct sockaddr_in sin;
478 
479 				in6_sin6_2_sin(&sin, &sin6);
480 				t = in_pcblookup_local_and_cleanup(pcbinfo,
481 				    sin.sin_addr, lport, wild);
482 				if (t != NULL && (reuseport &
483 				    t->inp_socket->so_options) == 0 &&
484 				    (t->inp_laddr.s_addr != INADDR_ANY ||
485 				    SOCK_DOM(so) == SOCK_DOM(t->inp_socket)) &&
486 				    (!(t->inp_flags2 & INP2_EXTERNAL_PORT) ||
487 				    !(inp->inp_flags2 & INP2_EXTERNAL_PORT) ||
488 				    uuid_compare(t->necp_client_uuid, inp->necp_client_uuid) != 0)) {
489 #if SKYWALK
490 					netns_release(&inp->inp_wildcard_netns_token);
491 #endif /* SKYWALK */
492 					lck_rw_done(&pcbinfo->ipi_lock);
493 					socket_lock(so, 0);
494 					error = EADDRINUSE;
495 					goto done;
496 				}
497 #if SKYWALK
498 				if ((SOCK_PROTO(so) == IPPROTO_TCP ||
499 				    SOCK_PROTO(so) == IPPROTO_UDP) &&
500 				    !(inp->inp_flags2 & INP2_EXTERNAL_PORT) &&
501 				    (!NETNS_TOKEN_VALID(
502 					    &inp->inp_wildcard_netns_token))) {
503 					if (netns_reserve_in(&inp->
504 					    inp_wildcard_netns_token,
505 					    sin.sin_addr,
506 					    (uint8_t)SOCK_PROTO(so), lport,
507 					    NETNS_BSD, NULL) != 0) {
508 						lck_rw_done(&pcbinfo->ipi_lock);
509 						socket_lock(so, 0);
510 						error = EADDRINUSE;
511 						goto done;
512 					}
513 				}
514 #endif /* SKYWALK */
515 			}
516 #if SKYWALK
517 			if ((SOCK_PROTO(so) == IPPROTO_TCP ||
518 			    SOCK_PROTO(so) == IPPROTO_UDP) &&
519 			    !(inp->inp_flags2 & INP2_EXTERNAL_PORT)) {
520 				if (netns_reserve_in6(&inp->inp_netns_token,
521 				    sin6.sin6_addr, (uint8_t)SOCK_PROTO(so), lport,
522 				    NETNS_BSD, NULL) != 0) {
523 					netns_release(&inp->inp_wildcard_netns_token);
524 					lck_rw_done(&pcbinfo->ipi_lock);
525 					socket_lock(so, 0);
526 					error = EADDRINUSE;
527 					goto done;
528 				}
529 			}
530 #endif /* SKYWALK */
531 		}
532 	}
533 
534 	socket_lock(so, 0);
535 	/*
536 	 * We unlocked socket's protocol lock for a long time.
537 	 * The socket might have been dropped/defuncted.
538 	 * Checking if world has changed since.
539 	 */
540 	if (inp->inp_state == INPCB_STATE_DEAD) {
541 #if SKYWALK
542 		netns_release(&inp->inp_netns_token);
543 		netns_release(&inp->inp_wildcard_netns_token);
544 #endif /* SKYWALK */
545 		lck_rw_done(&pcbinfo->ipi_lock);
546 		error = ECONNABORTED;
547 		goto done;
548 	}
549 
550 	/* check if the socket got bound when the lock was released */
551 	if (inp->inp_lport || !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
552 #if SKYWALK
553 		netns_release(&inp->inp_netns_token);
554 		netns_release(&inp->inp_wildcard_netns_token);
555 #endif /* SKYWALK */
556 		lck_rw_done(&pcbinfo->ipi_lock);
557 		error = EINVAL;
558 		goto done;
559 	}
560 
561 	if (!IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr)) {
562 		inp->in6p_laddr = sin6.sin6_addr;
563 		inp->in6p_last_outifp = outif;
564 		inp->inp_lifscope = lifscope;
565 		in6_verify_ifscope(&inp->in6p_laddr, lifscope);
566 #if SKYWALK
567 		if (NETNS_TOKEN_VALID(&inp->inp_netns_token)) {
568 			netns_set_ifnet(&inp->inp_netns_token,
569 			    inp->in6p_last_outifp);
570 		}
571 #endif /* SKYWALK */
572 	}
573 
574 	if (lport == 0) {
575 		int e;
576 		if ((e = in6_pcbsetport(&inp->in6p_laddr, remote, inp, p, 1)) != 0) {
577 			/* Undo any address bind from above. */
578 #if SKYWALK
579 			netns_release(&inp->inp_netns_token);
580 			netns_release(&inp->inp_wildcard_netns_token);
581 #endif /* SKYWALK */
582 			inp->in6p_laddr = in6addr_any;
583 			inp->in6p_last_outifp = NULL;
584 			inp->inp_lifscope = IFSCOPE_NONE;
585 			lck_rw_done(&pcbinfo->ipi_lock);
586 			error = e;
587 			goto done;
588 		}
589 	} else {
590 		inp->inp_lport = lport;
591 		if (in_pcbinshash(inp, remote, 1) != 0) {
592 #if SKYWALK
593 			netns_release(&inp->inp_netns_token);
594 			netns_release(&inp->inp_wildcard_netns_token);
595 #endif /* SKYWALK */
596 			inp->in6p_laddr = in6addr_any;
597 			inp->inp_lifscope = IFSCOPE_NONE;
598 			inp->inp_lport = 0;
599 			inp->in6p_last_outifp = NULL;
600 			lck_rw_done(&pcbinfo->ipi_lock);
601 			error = EAGAIN;
602 			goto done;
603 		}
604 	}
605 	lck_rw_done(&pcbinfo->ipi_lock);
606 	sflt_notify(so, sock_evt_bound, NULL);
607 done:
608 	return error;
609 }
610 
611 /*
612  * Transform old in6_pcbconnect() into an inner subroutine for new
613  * in6_pcbconnect(); do some validity-checking on the remote address
614  * (in "nam") and then determine local host address (i.e., which
615  * interface) to use to access that remote host.
616  *
617  * This routine may alter the caller-supplied remote address "nam".
618  *
619  * This routine might return an ifp with a reference held if the caller
620  * provides a non-NULL outif, even in the error case.  The caller is
621  * responsible for releasing its reference.
622  */
623 int
in6_pcbladdr(struct inpcb * inp,struct sockaddr * nam,struct in6_addr * plocal_addr6,struct ifnet ** outif)624 in6_pcbladdr(struct inpcb *inp, struct sockaddr *nam,
625     struct in6_addr *plocal_addr6, struct ifnet **outif)
626 {
627 	struct in6_addr *__single addr6 = NULL;
628 	struct in6_addr src_storage;
629 	int error = 0;
630 	unsigned int ifscope;
631 
632 	if (outif != NULL) {
633 		*outif = NULL;
634 	}
635 	if (nam->sa_len != sizeof(struct sockaddr_in6)) {
636 		return EINVAL;
637 	}
638 	if (SIN6(nam)->sin6_family != AF_INET6) {
639 		return EAFNOSUPPORT;
640 	}
641 	if (SIN6(nam)->sin6_port == 0) {
642 		return EADDRNOTAVAIL;
643 	}
644 
645 	/* KAME hack: embed scopeid */
646 	if (in6_embedscope(&SIN6(nam)->sin6_addr, SIN6(nam), inp, NULL, NULL, IN6_NULL_IF_EMBEDDED_SCOPE(&SIN6(nam)->sin6_scope_id)) != 0) {
647 		return EINVAL;
648 	}
649 
650 	in_pcb_check_management_entitled(inp);
651 	in_pcb_check_ultra_constrained_entitled(inp);
652 
653 	if (!TAILQ_EMPTY(&in6_ifaddrhead)) {
654 		/*
655 		 * If the destination address is UNSPECIFIED addr,
656 		 * use the loopback addr, e.g ::1.
657 		 */
658 		if (IN6_IS_ADDR_UNSPECIFIED(&SIN6(nam)->sin6_addr)) {
659 			SIN6(nam)->sin6_addr = in6addr_loopback;
660 		}
661 	}
662 
663 	ifscope = (inp->inp_flags & INP_BOUND_IF) ?
664 	    inp->inp_boundifp->if_index : IFSCOPE_NONE;
665 
666 	/*
667 	 * XXX: in6_selectsrc might replace the bound local address
668 	 * with the address specified by setsockopt(IPV6_PKTINFO).
669 	 * Is it the intended behavior?
670 	 *
671 	 * in6_selectsrc() might return outif with its reference held
672 	 * even in the error case; caller always needs to release it
673 	 * if non-NULL.
674 	 */
675 	addr6 = in6_selectsrc(SIN6(nam), inp->in6p_outputopts, inp,
676 	    &inp->in6p_route, outif, &src_storage, ifscope, &error);
677 
678 	if (outif != NULL) {
679 		rtentry_ref_t rt = inp->in6p_route.ro_rt;
680 		/*
681 		 * If in6_selectsrc() returns a route, it should be one
682 		 * which points to the same ifp as outif.  Just in case
683 		 * it isn't, use the one from the route for consistency.
684 		 * Otherwise if there is no route, leave outif alone as
685 		 * it could still be useful to the caller.
686 		 */
687 		if (rt != NULL && rt->rt_ifp != *outif) {
688 			ifnet_reference(rt->rt_ifp);    /* for caller */
689 			if (*outif != NULL) {
690 				ifnet_release(*outif);
691 			}
692 			*outif = rt->rt_ifp;
693 		}
694 	}
695 
696 	if (addr6 == NULL) {
697 		if (outif != NULL && (*outif) != NULL &&
698 		    inp_restricted_send(inp, *outif)) {
699 			soevent(inp->inp_socket,
700 			    (SO_FILT_HINT_LOCKED | SO_FILT_HINT_IFDENIED));
701 			error = EHOSTUNREACH;
702 		}
703 		if (error == 0) {
704 			error = EADDRNOTAVAIL;
705 		}
706 		return error;
707 	}
708 
709 	*plocal_addr6 = *addr6;
710 	/*
711 	 * Don't do pcblookup call here; return interface in
712 	 * plocal_addr6 and exit to caller, that will do the lookup.
713 	 */
714 	return 0;
715 }
716 
717 /*
718  * Outer subroutine:
719  * Connect from a socket to a specified address.
720  * Both address and port must be specified in argument sin.
721  * If don't have a local address for this socket yet,
722  * then pick one.
723  */
724 int
in6_pcbconnect(struct inpcb * inp,struct sockaddr * nam,struct proc * p)725 in6_pcbconnect(struct inpcb *inp, struct sockaddr *nam, struct proc *p)
726 {
727 	struct in6_addr addr6;
728 	struct sockaddr_in6 *__single sin6 = SIN6(nam);
729 	struct inpcb *__single pcb;
730 	int error = 0;
731 	ifnet_ref_t outif = NULL;
732 	struct socket *so = inp->inp_socket;
733 
734 #if CONTENT_FILTER
735 	so->so_state_change_cnt++;
736 #endif
737 
738 	if (SOCK_CHECK_PROTO(so, IPPROTO_UDP) &&
739 	    sin6->sin6_port == htons(53) && !(so->so_flags1 & SOF1_DNS_COUNTED)) {
740 		so->so_flags1 |= SOF1_DNS_COUNTED;
741 		INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_inet_dgram_dns);
742 	}
743 
744 	/*
745 	 * Call inner routine, to assign local interface address.
746 	 * in6_pcbladdr() may automatically fill in sin6_scope_id.
747 	 *
748 	 * in6_pcbladdr() might return an ifp with its reference held
749 	 * even in the error case, so make sure that it's released
750 	 * whenever it's non-NULL.
751 	 */
752 	if ((error = in6_pcbladdr(inp, nam, &addr6, &outif)) != 0) {
753 		if (outif != NULL && inp_restricted_send(inp, outif)) {
754 			soevent(so,
755 			    (SO_FILT_HINT_LOCKED | SO_FILT_HINT_IFDENIED));
756 		}
757 		goto done;
758 	}
759 	socket_unlock(so, 0);
760 
761 	uint32_t lifscope;
762 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
763 		lifscope = inp->inp_lifscope;
764 	} else if (outif != NULL) {
765 		lifscope = in6_addr2scopeid(outif, &addr6);
766 	} else {
767 		lifscope = sin6->sin6_scope_id;
768 	}
769 
770 	pcb = in6_pcblookup_hash(inp->inp_pcbinfo, &sin6->sin6_addr,
771 	    sin6->sin6_port, sin6->sin6_scope_id, IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) ?
772 	    &addr6 : &inp->in6p_laddr, inp->inp_lport, lifscope, 0, NULL);
773 	socket_lock(so, 0);
774 	if (pcb != NULL) {
775 		in_pcb_checkstate(pcb, WNT_RELEASE, pcb == inp ? 1 : 0);
776 		error = EADDRINUSE;
777 		goto done;
778 	}
779 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
780 		if (inp->inp_lport == 0) {
781 			error = in6_pcbbind(inp, NULL, nam, p);
782 			if (error) {
783 				goto done;
784 			}
785 		}
786 		inp->in6p_laddr = addr6;
787 		inp->in6p_last_outifp = outif;  /* no reference needed */
788 		if (IN6_IS_SCOPE_EMBED(&inp->in6p_laddr) &&
789 		    IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &sin6->sin6_addr)) {
790 			inp->inp_lifscope = sin6->sin6_scope_id;
791 		} else {
792 			inp->inp_lifscope = lifscope;
793 		}
794 		in6_verify_ifscope(&inp->in6p_laddr, inp->inp_lifscope);
795 #if SKYWALK
796 		if (NETNS_TOKEN_VALID(&inp->inp_netns_token)) {
797 			netns_set_ifnet(&inp->inp_netns_token,
798 			    inp->in6p_last_outifp);
799 		}
800 #endif /* SKYWALK */
801 		inp->in6p_flags |= INP_IN6ADDR_ANY;
802 	}
803 	if (!lck_rw_try_lock_exclusive(&inp->inp_pcbinfo->ipi_lock)) {
804 		/* lock inversion issue, mostly with udp multicast packets */
805 		socket_unlock(so, 0);
806 		lck_rw_lock_exclusive(&inp->inp_pcbinfo->ipi_lock);
807 		socket_lock(so, 0);
808 	}
809 	inp->in6p_faddr = sin6->sin6_addr;
810 	inp->inp_fport = sin6->sin6_port;
811 	inp->inp_fifscope = sin6->sin6_scope_id;
812 	in6_verify_ifscope(&inp->in6p_faddr, inp->inp_fifscope);
813 	if (nstat_collect && SOCK_PROTO(so) == IPPROTO_UDP) {
814 		nstat_pcb_invalidate_cache(inp);
815 	}
816 	in_pcbrehash(inp);
817 	lck_rw_done(&inp->inp_pcbinfo->ipi_lock);
818 
819 done:
820 	if (outif != NULL) {
821 		ifnet_release(outif);
822 	}
823 
824 	return error;
825 }
826 
827 void
in6_pcbdisconnect(struct inpcb * inp)828 in6_pcbdisconnect(struct inpcb *inp)
829 {
830 	struct socket *__single so = inp->inp_socket;
831 
832 #if CONTENT_FILTER
833 	if (so) {
834 		so->so_state_change_cnt++;
835 	}
836 #endif
837 
838 	if (!lck_rw_try_lock_exclusive(&inp->inp_pcbinfo->ipi_lock)) {
839 		/* lock inversion issue, mostly with udp multicast packets */
840 		socket_unlock(so, 0);
841 		lck_rw_lock_exclusive(&inp->inp_pcbinfo->ipi_lock);
842 		socket_lock(so, 0);
843 	}
844 	if (nstat_collect && SOCK_PROTO(so) == IPPROTO_UDP) {
845 		nstat_pcb_cache(inp);
846 	}
847 	bzero((caddr_t)&inp->in6p_faddr, sizeof(inp->in6p_faddr));
848 	inp->inp_fport = 0;
849 	/* clear flowinfo - RFC 6437 */
850 	inp->inp_flow &= ~IPV6_FLOWLABEL_MASK;
851 	in_pcbrehash(inp);
852 	lck_rw_done(&inp->inp_pcbinfo->ipi_lock);
853 	/*
854 	 * A multipath subflow socket would have its SS_NOFDREF set by default,
855 	 * so check for SOF_MP_SUBFLOW socket flag before detaching the PCB;
856 	 * when the socket is closed for real, SOF_MP_SUBFLOW would be cleared.
857 	 */
858 	if (!(so->so_flags & SOF_MP_SUBFLOW) && (so->so_state & SS_NOFDREF)) {
859 		in6_pcbdetach(inp);
860 	}
861 }
862 
863 void
in6_pcbdetach(struct inpcb * inp)864 in6_pcbdetach(struct inpcb *inp)
865 {
866 	struct socket *__single so = inp->inp_socket;
867 
868 	if (so->so_pcb == NULL) {
869 		/* PCB has been disposed */
870 		panic("%s: inp=%p so=%p proto=%d so_pcb is null!", __func__,
871 		    inp, so, SOCK_PROTO(so));
872 		/* NOTREACHED */
873 	}
874 
875 #if IPSEC
876 	if (inp->in6p_sp != NULL) {
877 		(void) ipsec6_delete_pcbpolicy(inp);
878 	}
879 #endif /* IPSEC */
880 
881 	if (inp->inp_stat != NULL && SOCK_PROTO(so) == IPPROTO_UDP) {
882 		if (inp->inp_stat->rxpackets == 0 && inp->inp_stat->txpackets == 0) {
883 			INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_inet6_dgram_no_data);
884 		}
885 	}
886 
887 	/*
888 	 * Let NetworkStatistics know this PCB is going away
889 	 * before we detach it.
890 	 */
891 	if (nstat_collect &&
892 	    (SOCK_PROTO(so) == IPPROTO_TCP || SOCK_PROTO(so) == IPPROTO_UDP)) {
893 		nstat_pcb_detach(inp);
894 	}
895 	/* mark socket state as dead */
896 	if (in_pcb_checkstate(inp, WNT_STOPUSING, 1) != WNT_STOPUSING) {
897 		panic("%s: so=%p proto=%d couldn't set to STOPUSING",
898 		    __func__, so, SOCK_PROTO(so));
899 		/* NOTREACHED */
900 	}
901 
902 #if SKYWALK
903 	/* Free up the port in the namespace registrar if not in TIME_WAIT */
904 	if (!(inp->inp_flags2 & INP2_TIMEWAIT)) {
905 		netns_release(&inp->inp_netns_token);
906 		netns_release(&inp->inp_wildcard_netns_token);
907 	}
908 #endif /* SKYWALK */
909 
910 	if (!(so->so_flags & SOF_PCBCLEARING)) {
911 		struct ip_moptions *__single imo;
912 		struct ip6_moptions *__single im6o;
913 
914 		inp->inp_vflag = 0;
915 		if (inp->in6p_options != NULL) {
916 			m_freem(inp->in6p_options);
917 			inp->in6p_options = NULL;
918 		}
919 		ip6_freepcbopts(inp->in6p_outputopts);
920 		inp->in6p_outputopts = NULL;
921 		ROUTE_RELEASE(&inp->in6p_route);
922 		/* free IPv4 related resources in case of mapped addr */
923 		if (inp->inp_options != NULL) {
924 			(void) m_free(inp->inp_options);
925 			inp->inp_options = NULL;
926 		}
927 		im6o = inp->in6p_moptions;
928 		inp->in6p_moptions = NULL;
929 		if (im6o != NULL) {
930 			IM6O_REMREF(im6o);
931 		}
932 		imo = inp->inp_moptions;
933 		inp->inp_moptions = NULL;
934 		if (imo != NULL) {
935 			IMO_REMREF(imo);
936 		}
937 
938 		sofreelastref(so, 0);
939 		inp->inp_state = INPCB_STATE_DEAD;
940 		/* makes sure we're not called twice from so_close */
941 		so->so_flags |= SOF_PCBCLEARING;
942 
943 		inpcb_gc_sched(inp->inp_pcbinfo, INPCB_TIMER_FAST);
944 	}
945 }
946 
947 struct sockaddr *
in6_sockaddr(in_port_t port,struct in6_addr * addr_p,uint32_t ifscope)948 in6_sockaddr(in_port_t port, struct in6_addr *addr_p, uint32_t ifscope)
949 {
950 	struct sockaddr_in6 *__single sin6;
951 
952 	sin6 = (struct sockaddr_in6 *)(alloc_sockaddr(sizeof(*sin6),
953 	    Z_WAITOK | Z_NOFAIL));
954 
955 	sin6->sin6_family = AF_INET6;
956 	sin6->sin6_port = port;
957 	sin6->sin6_addr = *addr_p;
958 
959 	/* would be good to use sa6_recoverscope(), except for locking  */
960 	if (IN6_IS_SCOPE_EMBED(&sin6->sin6_addr)) {
961 		sin6->sin6_scope_id = ifscope;
962 		if (in6_embedded_scope) {
963 			in6_verify_ifscope(&sin6->sin6_addr, ifscope);
964 			sin6->sin6_scope_id = ntohs(sin6->sin6_addr.s6_addr16[1]);
965 		}
966 	} else {
967 		sin6->sin6_scope_id = 0;        /* XXX */
968 	}
969 	if (in6_embedded_scope && IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr)) {
970 		sin6->sin6_addr.s6_addr16[1] = 0;
971 	}
972 
973 	return SA(sin6);
974 }
975 
976 void
in6_sockaddr_s(in_port_t port,struct in6_addr * addr_p,struct sockaddr_in6 * sin6,uint32_t ifscope)977 in6_sockaddr_s(in_port_t port, struct in6_addr *addr_p,
978     struct sockaddr_in6 *sin6, uint32_t ifscope)
979 {
980 	SOCKADDR_ZERO(sin6, sizeof(*sin6));
981 	sin6->sin6_family = AF_INET6;
982 	sin6->sin6_len = sizeof(*sin6);
983 	sin6->sin6_port = port;
984 	sin6->sin6_addr = *addr_p;
985 
986 	/* would be good to use sa6_recoverscope(), except for locking  */
987 	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr)) {
988 		sin6->sin6_scope_id = ifscope;
989 		if (in6_embedded_scope) {
990 			in6_verify_ifscope(&sin6->sin6_addr, ifscope);
991 			sin6->sin6_scope_id = ntohs(sin6->sin6_addr.s6_addr16[1]);
992 		}
993 	} else {
994 		sin6->sin6_scope_id = 0;        /* XXX */
995 	}
996 	if (in6_embedded_scope && IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr)) {
997 		sin6->sin6_addr.s6_addr16[1] = 0;
998 	}
999 }
1000 
1001 /*
1002  * The calling convention of in6_getsockaddr() and in6_getpeeraddr() was
1003  * modified to match the pru_sockaddr() and pru_peeraddr() entry points
1004  * in struct pr_usrreqs, so that protocols can just reference then directly
1005  * without the need for a wrapper function.
1006  */
1007 int
in6_getsockaddr(struct socket * so,struct sockaddr ** nam)1008 in6_getsockaddr(struct socket *so, struct sockaddr **nam)
1009 {
1010 	struct inpcb *__single inp;
1011 	struct in6_addr addr;
1012 	in_port_t port;
1013 
1014 	if ((inp = sotoinpcb(so)) == NULL) {
1015 		return EINVAL;
1016 	}
1017 
1018 	port = inp->inp_lport;
1019 	addr = inp->in6p_laddr;
1020 
1021 	*nam = in6_sockaddr(port, &addr, inp->inp_lifscope);
1022 	if (*nam == NULL) {
1023 		return ENOBUFS;
1024 	}
1025 	return 0;
1026 }
1027 
1028 int
in6_getsockaddr_s(struct socket * so,struct sockaddr_in6 * ss)1029 in6_getsockaddr_s(struct socket *so, struct sockaddr_in6 *ss)
1030 {
1031 	struct inpcb *__single inp;
1032 	struct in6_addr addr;
1033 	in_port_t port;
1034 
1035 	VERIFY(ss != NULL);
1036 	SOCKADDR_ZERO(ss, sizeof(*ss));
1037 
1038 	if ((inp = sotoinpcb(so)) == NULL) {
1039 		return EINVAL;
1040 	}
1041 
1042 	port = inp->inp_lport;
1043 	addr = inp->in6p_laddr;
1044 
1045 	in6_sockaddr_s(port, &addr, ss, inp->inp_lifscope);
1046 	return 0;
1047 }
1048 
1049 int
in6_getpeeraddr(struct socket * so,struct sockaddr ** nam)1050 in6_getpeeraddr(struct socket *so, struct sockaddr **nam)
1051 {
1052 	struct inpcb *__single inp;
1053 	struct in6_addr addr;
1054 	in_port_t port;
1055 
1056 	if ((inp = sotoinpcb(so)) == NULL) {
1057 		return EINVAL;
1058 	}
1059 
1060 	port = inp->inp_fport;
1061 	addr = inp->in6p_faddr;
1062 
1063 	*nam = in6_sockaddr(port, &addr, inp->inp_fifscope);
1064 	if (*nam == NULL) {
1065 		return ENOBUFS;
1066 	}
1067 	return 0;
1068 }
1069 
1070 int
in6_mapped_sockaddr(struct socket * so,struct sockaddr ** nam)1071 in6_mapped_sockaddr(struct socket *so, struct sockaddr **nam)
1072 {
1073 	struct  inpcb *__single inp = sotoinpcb(so);
1074 	int     error;
1075 
1076 	if (inp == NULL) {
1077 		return EINVAL;
1078 	}
1079 	if (inp->inp_vflag & INP_IPV4) {
1080 		error = in_getsockaddr(so, nam);
1081 		if (error == 0) {
1082 			error = in6_sin_2_v4mapsin6_in_sock(nam);
1083 		}
1084 	} else {
1085 		/* scope issues will be handled in in6_getsockaddr(). */
1086 		error = in6_getsockaddr(so, nam);
1087 	}
1088 	return error;
1089 }
1090 
1091 int
in6_mapped_peeraddr(struct socket * so,struct sockaddr ** nam)1092 in6_mapped_peeraddr(struct socket *so, struct sockaddr **nam)
1093 {
1094 	struct  inpcb *inp = sotoinpcb(so);
1095 	int     error;
1096 
1097 	if (inp == NULL) {
1098 		return EINVAL;
1099 	}
1100 	if (inp->inp_vflag & INP_IPV4) {
1101 		error = in_getpeeraddr(so, nam);
1102 		if (error == 0) {
1103 			error = in6_sin_2_v4mapsin6_in_sock(nam);
1104 		}
1105 	} else {
1106 		/* scope issues will be handled in in6_getpeeraddr(). */
1107 		error = in6_getpeeraddr(so, nam);
1108 	}
1109 	return error;
1110 }
1111 
1112 /*
1113  * Pass some notification to all connections of a protocol
1114  * associated with address dst.  The local address and/or port numbers
1115  * may be specified to limit the search.  The "usual action" will be
1116  * taken, depending on the ctlinput cmd.  The caller must filter any
1117  * cmds that are uninteresting (e.g., no error in the map).
1118  * Call the protocol specific routine (if any) to report
1119  * any errors for each matching socket.
1120  */
1121 void
in6_pcbnotify(struct inpcbinfo * pcbinfo,struct sockaddr * dst,u_int fport_arg,const struct sockaddr * src,u_int lport_arg,int cmd,void * cmdarg,void (* notify)(struct inpcb *,int))1122 in6_pcbnotify(struct inpcbinfo *pcbinfo, struct sockaddr *dst, u_int fport_arg,
1123     const struct sockaddr *src, u_int lport_arg, int cmd, void *cmdarg,
1124     void (*notify)(struct inpcb *, int))
1125 {
1126 	struct inpcbhead *__single head = pcbinfo->ipi_listhead;
1127 	struct inpcb *__single inp, *__single ninp;
1128 	struct sockaddr_in6 sa6_src;
1129 	struct sockaddr_in6 *__single sa6_dst;
1130 	uint16_t fport = (uint16_t)fport_arg, lport = (uint16_t)lport_arg;
1131 	u_int32_t flowinfo;
1132 	int errno;
1133 
1134 	if ((unsigned)cmd >= PRC_NCMDS || dst->sa_family != AF_INET6) {
1135 		return;
1136 	}
1137 
1138 	sa6_dst = SIN6(dst);
1139 	if (IN6_IS_ADDR_UNSPECIFIED(&sa6_dst->sin6_addr)) {
1140 		return;
1141 	}
1142 
1143 	/*
1144 	 * note that src can be NULL when we get notify by local fragmentation.
1145 	 */
1146 	sa6_src = (src == NULL) ?
1147 	    sa6_any : *SIN6(src);
1148 	flowinfo = sa6_src.sin6_flowinfo;
1149 
1150 	/*
1151 	 * Redirects go to all references to the destination,
1152 	 * and use in6_rtchange to invalidate the route cache.
1153 	 * Dead host indications: also use in6_rtchange to invalidate
1154 	 * the cache, and deliver the error to all the sockets.
1155 	 * Otherwise, if we have knowledge of the local port and address,
1156 	 * deliver only to that socket.
1157 	 */
1158 	if (PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) {
1159 		fport = 0;
1160 		lport = 0;
1161 		bzero((caddr_t)&sa6_src.sin6_addr, sizeof(sa6_src.sin6_addr));
1162 
1163 		if (cmd != PRC_HOSTDEAD) {
1164 			notify = in6_rtchange;
1165 		}
1166 	}
1167 	errno = inet6ctlerrmap[cmd];
1168 	lck_rw_lock_shared(&pcbinfo->ipi_lock);
1169 	for (inp = LIST_FIRST(head); inp != NULL; inp = ninp) {
1170 		ninp = LIST_NEXT(inp, inp_list);
1171 
1172 		if (!(inp->inp_vflag & INP_IPV6)) {
1173 			continue;
1174 		}
1175 
1176 		/*
1177 		 * If the error designates a new path MTU for a destination
1178 		 * and the application (associated with this socket) wanted to
1179 		 * know the value, notify. Note that we notify for all
1180 		 * disconnected sockets if the corresponding application
1181 		 * wanted. This is because some UDP applications keep sending
1182 		 * sockets disconnected.
1183 		 * XXX: should we avoid to notify the value to TCP sockets?
1184 		 */
1185 		if (cmd == PRC_MSGSIZE && cmdarg != NULL) {
1186 			socket_lock(inp->inp_socket, 1);
1187 			ip6_notify_pmtu(inp, SIN6(dst),
1188 			    (u_int32_t *)cmdarg);
1189 			socket_unlock(inp->inp_socket, 1);
1190 		}
1191 
1192 		/*
1193 		 * Detect if we should notify the error. If no source and
1194 		 * destination ports are specifed, but non-zero flowinfo and
1195 		 * local address match, notify the error. This is the case
1196 		 * when the error is delivered with an encrypted buffer
1197 		 * by ESP. Otherwise, just compare addresses and ports
1198 		 * as usual.
1199 		 */
1200 		if (lport == 0 && fport == 0 && flowinfo &&
1201 		    inp->inp_socket != NULL &&
1202 		    flowinfo == (inp->inp_flow & IPV6_FLOWLABEL_MASK) &&
1203 		    in6_are_addr_equal_scoped(&inp->in6p_laddr, &sa6_src.sin6_addr, inp->inp_lifscope, sa6_src.sin6_scope_id)) {
1204 			goto do_notify;
1205 		} else if (!in6_are_addr_equal_scoped(&inp->in6p_faddr, &sa6_dst->sin6_addr,
1206 		    inp->inp_fifscope, sa6_dst->sin6_scope_id) || inp->inp_socket == NULL ||
1207 		    (lport && inp->inp_lport != lport) ||
1208 		    (!IN6_IS_ADDR_UNSPECIFIED(&sa6_src.sin6_addr) &&
1209 		    !in6_are_addr_equal_scoped(&inp->in6p_laddr, &sa6_src.sin6_addr, inp->inp_lifscope, sa6_src.sin6_scope_id)) || (fport && inp->inp_fport != fport)) {
1210 			continue;
1211 		}
1212 
1213 do_notify:
1214 		if (notify) {
1215 			if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) ==
1216 			    WNT_STOPUSING) {
1217 				continue;
1218 			}
1219 			socket_lock(inp->inp_socket, 1);
1220 			(*notify)(inp, errno);
1221 			(void) in_pcb_checkstate(inp, WNT_RELEASE, 1);
1222 			socket_unlock(inp->inp_socket, 1);
1223 		}
1224 	}
1225 	lck_rw_done(&pcbinfo->ipi_lock);
1226 }
1227 
1228 /*
1229  * Lookup a PCB based on the local address and port.
1230  */
1231 struct inpcb *
in6_pcblookup_local(struct inpcbinfo * pcbinfo,struct in6_addr * laddr,u_int lport_arg,uint32_t ifscope,int wild_okay)1232 in6_pcblookup_local(struct inpcbinfo *pcbinfo, struct in6_addr *laddr,
1233     u_int lport_arg, uint32_t ifscope, int wild_okay)
1234 {
1235 	struct inpcb *__single inp;
1236 	int matchwild = 3, wildcard;
1237 	uint16_t lport = (uint16_t)lport_arg;
1238 	struct inpcbporthead *__single porthash;
1239 	struct inpcb *__single match = NULL;
1240 	struct inpcbport *__single phd;
1241 
1242 	if (!wild_okay) {
1243 		struct inpcbhead *__single head;
1244 		/*
1245 		 * Look for an unconnected (wildcard foreign addr) PCB that
1246 		 * matches the local address and port we're looking for.
1247 		 */
1248 		head = &pcbinfo->ipi_hashbase[INP_PCBHASH(INADDR_ANY, lport, 0,
1249 		    pcbinfo->ipi_hashmask)];
1250 		LIST_FOREACH(inp, head, inp_hash) {
1251 			if (!(inp->inp_vflag & INP_IPV6)) {
1252 				continue;
1253 			}
1254 			if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
1255 			    in6_are_addr_equal_scoped(&inp->in6p_laddr, laddr, inp->inp_lifscope, ifscope) &&
1256 			    inp->inp_lport == lport) {
1257 				/*
1258 				 * Found.
1259 				 */
1260 				return inp;
1261 			}
1262 		}
1263 		/*
1264 		 * Not found.
1265 		 */
1266 		return NULL;
1267 	}
1268 	/*
1269 	 * Best fit PCB lookup.
1270 	 *
1271 	 * First see if this local port is in use by looking on the
1272 	 * port hash list.
1273 	 */
1274 	porthash = &pcbinfo->ipi_porthashbase[INP_PCBPORTHASH(lport,
1275 	    pcbinfo->ipi_porthashmask)];
1276 	LIST_FOREACH(phd, porthash, phd_hash) {
1277 		if (phd->phd_port == lport) {
1278 			break;
1279 		}
1280 	}
1281 
1282 	if (phd != NULL) {
1283 		/*
1284 		 * Port is in use by one or more PCBs. Look for best
1285 		 * fit.
1286 		 */
1287 		LIST_FOREACH(inp, &phd->phd_pcblist, inp_portlist) {
1288 			wildcard = 0;
1289 			if (!(inp->inp_vflag & INP_IPV6)) {
1290 				continue;
1291 			}
1292 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1293 				wildcard++;
1294 			}
1295 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
1296 				if (IN6_IS_ADDR_UNSPECIFIED(laddr)) {
1297 					wildcard++;
1298 				} else if (!in6_are_addr_equal_scoped(
1299 					    &inp->in6p_laddr, laddr, inp->inp_lifscope, ifscope)) {
1300 					continue;
1301 				}
1302 			} else {
1303 				if (!IN6_IS_ADDR_UNSPECIFIED(laddr)) {
1304 					wildcard++;
1305 				}
1306 			}
1307 			if (wildcard < matchwild) {
1308 				match = inp;
1309 				matchwild = wildcard;
1310 				if (matchwild == 0) {
1311 					break;
1312 				}
1313 			}
1314 		}
1315 	}
1316 	return match;
1317 }
1318 
1319 /*
1320  * Check for alternatives when higher level complains
1321  * about service problems.  For now, invalidate cached
1322  * routing information.  If the route was created dynamically
1323  * (by a redirect), time to try a default gateway again.
1324  */
1325 void
in6_losing(struct inpcb * in6p)1326 in6_losing(struct inpcb *in6p)
1327 {
1328 	rtentry_ref_t rt;
1329 
1330 	if ((rt = in6p->in6p_route.ro_rt) != NULL) {
1331 		RT_LOCK(rt);
1332 		if (rt->rt_flags & RTF_DYNAMIC) {
1333 			/*
1334 			 * Prevent another thread from modifying rt_key,
1335 			 * rt_gateway via rt_setgate() after the rt_lock
1336 			 * is dropped by marking the route as defunct.
1337 			 */
1338 			rt->rt_flags |= RTF_CONDEMNED;
1339 			RT_UNLOCK(rt);
1340 			(void) rtrequest(RTM_DELETE, rt_key(rt),
1341 			    rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
1342 		} else {
1343 			RT_UNLOCK(rt);
1344 		}
1345 		/*
1346 		 * A new route can be allocated
1347 		 * the next time output is attempted.
1348 		 */
1349 	}
1350 	ROUTE_RELEASE(&in6p->in6p_route);
1351 }
1352 
1353 /*
1354  * After a routing change, flush old routing
1355  * and allocate a (hopefully) better one.
1356  */
1357 void
in6_rtchange(struct inpcb * inp,int errno)1358 in6_rtchange(struct inpcb *inp, int errno)
1359 {
1360 #pragma unused(errno)
1361 	/*
1362 	 * A new route can be allocated the next time
1363 	 * output is attempted.
1364 	 */
1365 	ROUTE_RELEASE(&inp->in6p_route);
1366 }
1367 
1368 /*
1369  * Check if PCB exists hash list. Also returns uid and gid of socket
1370  */
1371 int
in6_pcblookup_hash_exists(struct inpcbinfo * pcbinfo,struct in6_addr * faddr,u_int fport_arg,uint32_t fifscope,struct in6_addr * laddr,u_int lport_arg,uint32_t lifscope,int wildcard,uid_t * uid,gid_t * gid,struct ifnet * ifp,bool relaxed)1372 in6_pcblookup_hash_exists(struct inpcbinfo *pcbinfo, struct in6_addr *faddr,
1373     u_int fport_arg, uint32_t fifscope, struct in6_addr *laddr, u_int lport_arg, uint32_t lifscope, int wildcard,
1374     uid_t *uid, gid_t *gid, struct ifnet *ifp, bool relaxed)
1375 {
1376 	struct inpcbhead *__single head;
1377 	struct inpcb *__single inp;
1378 	uint16_t fport = (uint16_t)fport_arg, lport = (uint16_t)lport_arg;
1379 	int found;
1380 
1381 	*uid = UID_MAX;
1382 	*gid = GID_MAX;
1383 
1384 	lck_rw_lock_shared(&pcbinfo->ipi_lock);
1385 
1386 	/*
1387 	 * First look for an exact match.
1388 	 */
1389 	head = &pcbinfo->ipi_hashbase[INP_PCBHASH(faddr->s6_addr32[3] /* XXX */,
1390 	    lport, fport, pcbinfo->ipi_hashmask)];
1391 	LIST_FOREACH(inp, head, inp_hash) {
1392 		if (!(inp->inp_vflag & INP_IPV6)) {
1393 			continue;
1394 		}
1395 
1396 		if (inp_restricted_recv(inp, ifp)) {
1397 			continue;
1398 		}
1399 
1400 #if NECP
1401 		if (!necp_socket_is_allowed_to_recv_on_interface(inp, ifp)) {
1402 			continue;
1403 		}
1404 #endif /* NECP */
1405 
1406 		if (((in6_are_addr_equal_scoped(&inp->in6p_faddr, faddr, inp->inp_fifscope, fifscope) &&
1407 		    in6_are_addr_equal_scoped(&inp->in6p_laddr, laddr, inp->inp_lifscope, lifscope)) ||
1408 		    (relaxed &&
1409 		    IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, faddr) &&
1410 		    IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, laddr))) &&
1411 		    inp->inp_fport == fport &&
1412 		    inp->inp_lport == lport) {
1413 			if ((found = (inp->inp_socket != NULL))) {
1414 				/*
1415 				 * Found. Check if pcb is still valid
1416 				 */
1417 				*uid = kauth_cred_getuid(
1418 					inp->inp_socket->so_cred);
1419 				*gid = kauth_cred_getgid(
1420 					inp->inp_socket->so_cred);
1421 			}
1422 			lck_rw_done(&pcbinfo->ipi_lock);
1423 			return found;
1424 		}
1425 	}
1426 	if (wildcard) {
1427 		struct inpcb *__single local_wild = NULL;
1428 
1429 		head = &pcbinfo->ipi_hashbase[INP_PCBHASH(INADDR_ANY, lport, 0,
1430 		    pcbinfo->ipi_hashmask)];
1431 		LIST_FOREACH(inp, head, inp_hash) {
1432 			if (!(inp->inp_vflag & INP_IPV6)) {
1433 				continue;
1434 			}
1435 
1436 			if (inp_restricted_recv(inp, ifp)) {
1437 				continue;
1438 			}
1439 
1440 #if NECP
1441 			if (!necp_socket_is_allowed_to_recv_on_interface(inp, ifp)) {
1442 				continue;
1443 			}
1444 #endif /* NECP */
1445 
1446 			if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
1447 			    inp->inp_lport == lport) {
1448 				if (in6_are_addr_equal_scoped(&inp->in6p_laddr,
1449 				    laddr, inp->inp_lifscope, lifscope) ||
1450 				    (relaxed && IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, laddr))) {
1451 					found = (inp->inp_socket != NULL);
1452 					if (found) {
1453 						*uid = kauth_cred_getuid(
1454 							inp->inp_socket->so_cred);
1455 						*gid = kauth_cred_getgid(
1456 							inp->inp_socket->so_cred);
1457 					}
1458 					lck_rw_done(&pcbinfo->ipi_lock);
1459 					return found;
1460 				} else if (IN6_IS_ADDR_UNSPECIFIED(
1461 					    &inp->in6p_laddr)) {
1462 					local_wild = inp;
1463 				}
1464 			}
1465 		}
1466 		if (local_wild) {
1467 			if ((found = (local_wild->inp_socket != NULL))) {
1468 				*uid = kauth_cred_getuid(
1469 					local_wild->inp_socket->so_cred);
1470 				*gid = kauth_cred_getgid(
1471 					local_wild->inp_socket->so_cred);
1472 			}
1473 			lck_rw_done(&pcbinfo->ipi_lock);
1474 			return found;
1475 		}
1476 	}
1477 
1478 	/*
1479 	 * Not found.
1480 	 */
1481 	lck_rw_done(&pcbinfo->ipi_lock);
1482 	return 0;
1483 }
1484 
1485 /*
1486  * Lookup PCB in hash list.
1487  */
1488 static struct inpcb *
in6_pcblookup_hash_locked(struct inpcbinfo * pcbinfo,struct in6_addr * faddr,u_int fport_arg,uint32_t fifscope,struct in6_addr * laddr,u_int lport_arg,uint32_t lifscope,int wildcard,struct ifnet * ifp)1489 in6_pcblookup_hash_locked(struct inpcbinfo *pcbinfo, struct in6_addr *faddr,
1490     u_int fport_arg, uint32_t fifscope, struct in6_addr *laddr, u_int lport_arg,
1491     uint32_t lifscope, int wildcard, struct ifnet *ifp)
1492 {
1493 	struct inpcbhead *__single head;
1494 	struct inpcb *__single inp;
1495 	uint16_t fport = (uint16_t)fport_arg, lport = (uint16_t)lport_arg;
1496 
1497 	/*
1498 	 * First look for an exact match.
1499 	 */
1500 	head = &pcbinfo->ipi_hashbase[INP_PCBHASH(faddr->s6_addr32[3] /* XXX */,
1501 	    lport, fport, pcbinfo->ipi_hashmask)];
1502 	LIST_FOREACH(inp, head, inp_hash) {
1503 		if (!(inp->inp_vflag & INP_IPV6)) {
1504 			continue;
1505 		}
1506 
1507 		if (inp_restricted_recv(inp, ifp)) {
1508 			continue;
1509 		}
1510 
1511 #if NECP
1512 		if (!necp_socket_is_allowed_to_recv_on_interface(inp, ifp)) {
1513 			continue;
1514 		}
1515 #endif /* NECP */
1516 
1517 		if (in6_are_addr_equal_scoped(&inp->in6p_faddr, faddr, inp->inp_fifscope, fifscope) &&
1518 		    in6_are_addr_equal_scoped(&inp->in6p_laddr, laddr, inp->inp_lifscope, lifscope) &&
1519 		    inp->inp_fport == fport &&
1520 		    inp->inp_lport == lport) {
1521 			/*
1522 			 * Found. Check if pcb is still valid
1523 			 */
1524 			if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) !=
1525 			    WNT_STOPUSING) {
1526 				return inp;
1527 			} else {
1528 				/* it's there but dead, say it isn't found */
1529 				return NULL;
1530 			}
1531 		}
1532 	}
1533 	if (wildcard) {
1534 		struct inpcb *__single local_wild = NULL;
1535 
1536 		head = &pcbinfo->ipi_hashbase[INP_PCBHASH(INADDR_ANY, lport, 0,
1537 		    pcbinfo->ipi_hashmask)];
1538 		LIST_FOREACH(inp, head, inp_hash) {
1539 			if (!(inp->inp_vflag & INP_IPV6)) {
1540 				continue;
1541 			}
1542 
1543 			if (inp_restricted_recv(inp, ifp)) {
1544 				continue;
1545 			}
1546 
1547 #if NECP
1548 			if (!necp_socket_is_allowed_to_recv_on_interface(inp, ifp)) {
1549 				continue;
1550 			}
1551 #endif /* NECP */
1552 
1553 			if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
1554 			    inp->inp_lport == lport) {
1555 				if (in6_are_addr_equal_scoped(&inp->in6p_laddr,
1556 				    laddr, inp->inp_lifscope, lifscope)) {
1557 					if (in_pcb_checkstate(inp, WNT_ACQUIRE,
1558 					    0) != WNT_STOPUSING) {
1559 						return inp;
1560 					} else {
1561 						/* dead; say it isn't found */
1562 						return NULL;
1563 					}
1564 				} else if (IN6_IS_ADDR_UNSPECIFIED(
1565 					    &inp->in6p_laddr)) {
1566 					local_wild = inp;
1567 				}
1568 			}
1569 		}
1570 		if (local_wild && in_pcb_checkstate(local_wild,
1571 		    WNT_ACQUIRE, 0) != WNT_STOPUSING) {
1572 			return local_wild;
1573 		} else {
1574 			return NULL;
1575 		}
1576 	}
1577 
1578 	/*
1579 	 * Not found.
1580 	 */
1581 	return NULL;
1582 }
1583 
1584 struct inpcb *
in6_pcblookup_hash(struct inpcbinfo * pcbinfo,struct in6_addr * faddr,u_int fport_arg,uint32_t fifscope,struct in6_addr * laddr,u_int lport_arg,uint32_t lifscope,int wildcard,struct ifnet * ifp)1585 in6_pcblookup_hash(struct inpcbinfo *pcbinfo, struct in6_addr *faddr,
1586     u_int fport_arg, uint32_t fifscope, struct in6_addr *laddr, u_int lport_arg,
1587     uint32_t lifscope, int wildcard, struct ifnet *ifp)
1588 {
1589 	struct inpcb *inp;
1590 
1591 	lck_rw_lock_shared(&pcbinfo->ipi_lock);
1592 
1593 	inp = in6_pcblookup_hash_locked(pcbinfo, faddr, fport_arg, fifscope,
1594 	    laddr, lport_arg, lifscope, wildcard, ifp);
1595 
1596 	lck_rw_done(&pcbinfo->ipi_lock);
1597 
1598 	return inp;
1599 }
1600 
1601 struct inpcb *
in6_pcblookup_hash_try(struct inpcbinfo * pcbinfo,struct in6_addr * faddr,u_int fport_arg,uint32_t fifscope,struct in6_addr * laddr,u_int lport_arg,uint32_t lifscope,int wildcard,struct ifnet * ifp)1602 in6_pcblookup_hash_try(struct inpcbinfo *pcbinfo, struct in6_addr *faddr,
1603     u_int fport_arg, uint32_t fifscope, struct in6_addr *laddr, u_int lport_arg,
1604     uint32_t lifscope, int wildcard, struct ifnet *ifp)
1605 {
1606 	struct inpcb *inp;
1607 
1608 	if (!lck_rw_try_lock_shared(&pcbinfo->ipi_lock)) {
1609 		return NULL;
1610 	}
1611 
1612 	inp = in6_pcblookup_hash_locked(pcbinfo, faddr, fport_arg, fifscope,
1613 	    laddr, lport_arg, lifscope, wildcard, ifp);
1614 
1615 	lck_rw_done(&pcbinfo->ipi_lock);
1616 
1617 	return inp;
1618 }
1619 
1620 void
init_sin6(struct sockaddr_in6 * sin6,struct mbuf * m)1621 init_sin6(struct sockaddr_in6 *sin6, struct mbuf *m)
1622 {
1623 	struct ip6_hdr *__single ip;
1624 
1625 	ip = mtod(m, struct ip6_hdr *);
1626 	SOCKADDR_ZERO(sin6, sizeof(*sin6));
1627 	sin6->sin6_len = sizeof(*sin6);
1628 	sin6->sin6_family = AF_INET6;
1629 	sin6->sin6_addr = ip->ip6_src;
1630 	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr)) {
1631 		if (in6_embedded_scope) {
1632 			sin6->sin6_addr.s6_addr16[1] = 0;
1633 		}
1634 		if ((m->m_pkthdr.pkt_flags & (PKTF_LOOP | PKTF_IFAINFO)) ==
1635 		    (PKTF_LOOP | PKTF_IFAINFO)) {
1636 			sin6->sin6_scope_id = m->m_pkthdr.src_ifindex;
1637 		} else if (m->m_pkthdr.rcvif != NULL) {
1638 			sin6->sin6_scope_id = m->m_pkthdr.rcvif->if_index;
1639 		}
1640 	}
1641 }
1642 
1643 /*
1644  * The following routines implement this scheme:
1645  *
1646  * Callers of ip6_output() that intend to cache the route in the inpcb pass
1647  * a local copy of the struct route to ip6_output().  Using a local copy of
1648  * the cached route significantly simplifies things as IP no longer has to
1649  * worry about having exclusive access to the passed in struct route, since
1650  * it's defined in the caller's stack; in essence, this allows for a lock-
1651  * less operation when updating the struct route at the IP level and below,
1652  * whenever necessary. The scheme works as follows:
1653  *
1654  * Prior to dropping the socket's lock and calling ip6_output(), the caller
1655  * copies the struct route from the inpcb into its stack, and adds a reference
1656  * to the cached route entry, if there was any.  The socket's lock is then
1657  * dropped and ip6_output() is called with a pointer to the copy of struct
1658  * route defined on the stack (not to the one in the inpcb.)
1659  *
1660  * Upon returning from ip6_output(), the caller then acquires the socket's
1661  * lock and synchronizes the cache; if there is no route cached in the inpcb,
1662  * it copies the local copy of struct route (which may or may not contain any
1663  * route) back into the cache; otherwise, if the inpcb has a route cached in
1664  * it, the one in the local copy will be freed, if there's any.  Trashing the
1665  * cached route in the inpcb can be avoided because ip6_output() is single-
1666  * threaded per-PCB (i.e. multiple transmits on a PCB are always serialized
1667  * by the socket/transport layer.)
1668  */
1669 void
in6p_route_copyout(struct inpcb * inp,struct route_in6 * dst)1670 in6p_route_copyout(struct inpcb *inp, struct route_in6 *dst)
1671 {
1672 	struct route_in6 *__single src = &inp->in6p_route;
1673 
1674 	socket_lock_assert_owned(inp->inp_socket);
1675 
1676 	/* Minor sanity check */
1677 	if (src->ro_rt != NULL && rt_key(src->ro_rt)->sa_family != AF_INET6) {
1678 		panic("%s: wrong or corrupted route: %p", __func__, src);
1679 	}
1680 
1681 	route_copyout((struct route *)dst, (struct route *)src, sizeof(*dst));
1682 }
1683 
1684 void
in6p_route_copyin(struct inpcb * inp,struct route_in6 * src)1685 in6p_route_copyin(struct inpcb *inp, struct route_in6 *src)
1686 {
1687 	struct route_in6 *__single dst = &inp->in6p_route;
1688 
1689 	socket_lock_assert_owned(inp->inp_socket);
1690 
1691 	/* Minor sanity check */
1692 	if (src->ro_rt != NULL && rt_key(src->ro_rt)->sa_family != AF_INET6) {
1693 		panic("%s: wrong or corrupted route: %p", __func__, src);
1694 	}
1695 
1696 	route_copyin((struct route *)src, (struct route *)dst, sizeof(*src));
1697 }
1698