xref: /freebsd/sys/kern/uipc_syscalls.c (revision ec0ea6efa1ad229d75c394c1a9b9cac33af2b1d3)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1989, 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)uipc_syscalls.c	8.4 (Berkeley) 2/21/94
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "opt_capsicum.h"
38 #include "opt_inet.h"
39 #include "opt_inet6.h"
40 #include "opt_ktrace.h"
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/capsicum.h>
45 #include <sys/kernel.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/sysproto.h>
49 #include <sys/malloc.h>
50 #include <sys/filedesc.h>
51 #include <sys/proc.h>
52 #include <sys/filio.h>
53 #include <sys/jail.h>
54 #include <sys/mbuf.h>
55 #include <sys/protosw.h>
56 #include <sys/rwlock.h>
57 #include <sys/socket.h>
58 #include <sys/socketvar.h>
59 #include <sys/syscallsubr.h>
60 #include <sys/sysent.h>
61 #include <sys/uio.h>
62 #include <sys/un.h>
63 #include <sys/unpcb.h>
64 #ifdef KTRACE
65 #include <sys/ktrace.h>
66 #endif
67 #ifdef COMPAT_FREEBSD32
68 #include <compat/freebsd32/freebsd32_util.h>
69 #endif
70 
71 #include <net/vnet.h>
72 
73 #include <security/audit/audit.h>
74 #include <security/mac/mac_framework.h>
75 
76 static int sendit(struct thread *td, int s, struct msghdr *mp, int flags);
77 static int recvit(struct thread *td, int s, struct msghdr *mp, void *namelenp);
78 
79 static int accept1(struct thread *td, int s, struct sockaddr *uname,
80 		   socklen_t *anamelen, int flags);
81 static int sockargs(struct mbuf **, char *, socklen_t, int);
82 
83 /*
84  * Convert a user file descriptor to a kernel file entry and check if required
85  * capability rights are present.
86  * If required copy of current set of capability rights is returned.
87  * A reference on the file entry is held upon returning.
88  */
89 int
90 getsock_cap(struct thread *td, int fd, cap_rights_t *rightsp,
91     struct file **fpp, u_int *fflagp, struct filecaps *havecapsp)
92 {
93 	struct file *fp;
94 	int error;
95 
96 	error = fget_cap(td, fd, rightsp, &fp, havecapsp);
97 	if (error != 0)
98 		return (error);
99 	if (fp->f_type != DTYPE_SOCKET) {
100 		fdrop(fp, td);
101 		if (havecapsp != NULL)
102 			filecaps_free(havecapsp);
103 		return (ENOTSOCK);
104 	}
105 	if (fflagp != NULL)
106 		*fflagp = fp->f_flag;
107 	*fpp = fp;
108 	return (0);
109 }
110 
111 /*
112  * System call interface to the socket abstraction.
113  */
114 #if defined(COMPAT_43)
115 #define COMPAT_OLDSOCK
116 #endif
117 
118 int
119 sys_socket(struct thread *td, struct socket_args *uap)
120 {
121 
122 	return (kern_socket(td, uap->domain, uap->type, uap->protocol));
123 }
124 
125 int
126 kern_socket(struct thread *td, int domain, int type, int protocol)
127 {
128 	struct socket *so;
129 	struct file *fp;
130 	int fd, error, oflag, fflag;
131 
132 	AUDIT_ARG_SOCKET(domain, type, protocol);
133 
134 	oflag = 0;
135 	fflag = 0;
136 	if ((type & SOCK_CLOEXEC) != 0) {
137 		type &= ~SOCK_CLOEXEC;
138 		oflag |= O_CLOEXEC;
139 	}
140 	if ((type & SOCK_NONBLOCK) != 0) {
141 		type &= ~SOCK_NONBLOCK;
142 		fflag |= FNONBLOCK;
143 	}
144 
145 #ifdef MAC
146 	error = mac_socket_check_create(td->td_ucred, domain, type, protocol);
147 	if (error != 0)
148 		return (error);
149 #endif
150 	error = falloc(td, &fp, &fd, oflag);
151 	if (error != 0)
152 		return (error);
153 	/* An extra reference on `fp' has been held for us by falloc(). */
154 	error = socreate(domain, &so, type, protocol, td->td_ucred, td);
155 	if (error != 0) {
156 		fdclose(td, fp, fd);
157 	} else {
158 		finit(fp, FREAD | FWRITE | fflag, DTYPE_SOCKET, so, &socketops);
159 		if ((fflag & FNONBLOCK) != 0)
160 			(void) fo_ioctl(fp, FIONBIO, &fflag, td->td_ucred, td);
161 		td->td_retval[0] = fd;
162 	}
163 	fdrop(fp, td);
164 	return (error);
165 }
166 
167 int
168 sys_bind(struct thread *td, struct bind_args *uap)
169 {
170 	struct sockaddr *sa;
171 	int error;
172 
173 	error = getsockaddr(&sa, uap->name, uap->namelen);
174 	if (error == 0) {
175 		error = kern_bindat(td, AT_FDCWD, uap->s, sa);
176 		free(sa, M_SONAME);
177 	}
178 	return (error);
179 }
180 
181 int
182 kern_bindat(struct thread *td, int dirfd, int fd, struct sockaddr *sa)
183 {
184 	struct socket *so;
185 	struct file *fp;
186 	int error;
187 
188 #ifdef CAPABILITY_MODE
189 	if (IN_CAPABILITY_MODE(td) && (dirfd == AT_FDCWD))
190 		return (ECAPMODE);
191 #endif
192 
193 	AUDIT_ARG_FD(fd);
194 	AUDIT_ARG_SOCKADDR(td, dirfd, sa);
195 	error = getsock_cap(td, fd, &cap_bind_rights,
196 	    &fp, NULL, NULL);
197 	if (error != 0)
198 		return (error);
199 	so = fp->f_data;
200 #ifdef KTRACE
201 	if (KTRPOINT(td, KTR_STRUCT))
202 		ktrsockaddr(sa);
203 #endif
204 #ifdef MAC
205 	error = mac_socket_check_bind(td->td_ucred, so, sa);
206 	if (error == 0) {
207 #endif
208 		if (dirfd == AT_FDCWD)
209 			error = sobind(so, sa, td);
210 		else
211 			error = sobindat(dirfd, so, sa, td);
212 #ifdef MAC
213 	}
214 #endif
215 	fdrop(fp, td);
216 	return (error);
217 }
218 
219 int
220 sys_bindat(struct thread *td, struct bindat_args *uap)
221 {
222 	struct sockaddr *sa;
223 	int error;
224 
225 	error = getsockaddr(&sa, uap->name, uap->namelen);
226 	if (error == 0) {
227 		error = kern_bindat(td, uap->fd, uap->s, sa);
228 		free(sa, M_SONAME);
229 	}
230 	return (error);
231 }
232 
233 int
234 sys_listen(struct thread *td, struct listen_args *uap)
235 {
236 
237 	return (kern_listen(td, uap->s, uap->backlog));
238 }
239 
240 int
241 kern_listen(struct thread *td, int s, int backlog)
242 {
243 	struct socket *so;
244 	struct file *fp;
245 	int error;
246 
247 	AUDIT_ARG_FD(s);
248 	error = getsock_cap(td, s, &cap_listen_rights,
249 	    &fp, NULL, NULL);
250 	if (error == 0) {
251 		so = fp->f_data;
252 #ifdef MAC
253 		error = mac_socket_check_listen(td->td_ucred, so);
254 		if (error == 0)
255 #endif
256 			error = solisten(so, backlog, td);
257 		fdrop(fp, td);
258 	}
259 	return (error);
260 }
261 
262 /*
263  * accept1()
264  */
265 static int
266 accept1(td, s, uname, anamelen, flags)
267 	struct thread *td;
268 	int s;
269 	struct sockaddr *uname;
270 	socklen_t *anamelen;
271 	int flags;
272 {
273 	struct sockaddr *name;
274 	socklen_t namelen;
275 	struct file *fp;
276 	int error;
277 
278 	if (uname == NULL)
279 		return (kern_accept4(td, s, NULL, NULL, flags, NULL));
280 
281 	error = copyin(anamelen, &namelen, sizeof (namelen));
282 	if (error != 0)
283 		return (error);
284 
285 	error = kern_accept4(td, s, &name, &namelen, flags, &fp);
286 
287 	if (error != 0)
288 		return (error);
289 
290 	if (error == 0 && uname != NULL) {
291 #ifdef COMPAT_OLDSOCK
292 		if (SV_PROC_FLAG(td->td_proc, SV_AOUT) &&
293 		    (flags & ACCEPT4_COMPAT) != 0)
294 			((struct osockaddr *)name)->sa_family =
295 			    name->sa_family;
296 #endif
297 		error = copyout(name, uname, namelen);
298 	}
299 	if (error == 0)
300 		error = copyout(&namelen, anamelen,
301 		    sizeof(namelen));
302 	if (error != 0)
303 		fdclose(td, fp, td->td_retval[0]);
304 	fdrop(fp, td);
305 	free(name, M_SONAME);
306 	return (error);
307 }
308 
309 int
310 kern_accept(struct thread *td, int s, struct sockaddr **name,
311     socklen_t *namelen, struct file **fp)
312 {
313 	return (kern_accept4(td, s, name, namelen, ACCEPT4_INHERIT, fp));
314 }
315 
316 int
317 kern_accept4(struct thread *td, int s, struct sockaddr **name,
318     socklen_t *namelen, int flags, struct file **fp)
319 {
320 	struct file *headfp, *nfp = NULL;
321 	struct sockaddr *sa = NULL;
322 	struct socket *head, *so;
323 	struct filecaps fcaps;
324 	u_int fflag;
325 	pid_t pgid;
326 	int error, fd, tmp;
327 
328 	if (name != NULL)
329 		*name = NULL;
330 
331 	AUDIT_ARG_FD(s);
332 	error = getsock_cap(td, s, &cap_accept_rights,
333 	    &headfp, &fflag, &fcaps);
334 	if (error != 0)
335 		return (error);
336 	head = headfp->f_data;
337 	if (!SOLISTENING(head)) {
338 		error = EINVAL;
339 		goto done;
340 	}
341 #ifdef MAC
342 	error = mac_socket_check_accept(td->td_ucred, head);
343 	if (error != 0)
344 		goto done;
345 #endif
346 	error = falloc_caps(td, &nfp, &fd,
347 	    (flags & SOCK_CLOEXEC) ? O_CLOEXEC : 0, &fcaps);
348 	if (error != 0)
349 		goto done;
350 	SOCK_LOCK(head);
351 	if (!SOLISTENING(head)) {
352 		SOCK_UNLOCK(head);
353 		error = EINVAL;
354 		goto noconnection;
355 	}
356 
357 	error = solisten_dequeue(head, &so, flags);
358 	if (error != 0)
359 		goto noconnection;
360 
361 	/* An extra reference on `nfp' has been held for us by falloc(). */
362 	td->td_retval[0] = fd;
363 
364 	/* Connection has been removed from the listen queue. */
365 	KNOTE_UNLOCKED(&head->so_rdsel.si_note, 0);
366 
367 	if (flags & ACCEPT4_INHERIT) {
368 		pgid = fgetown(&head->so_sigio);
369 		if (pgid != 0)
370 			fsetown(pgid, &so->so_sigio);
371 	} else {
372 		fflag &= ~(FNONBLOCK | FASYNC);
373 		if (flags & SOCK_NONBLOCK)
374 			fflag |= FNONBLOCK;
375 	}
376 
377 	finit(nfp, fflag, DTYPE_SOCKET, so, &socketops);
378 	/* Sync socket nonblocking/async state with file flags */
379 	tmp = fflag & FNONBLOCK;
380 	(void) fo_ioctl(nfp, FIONBIO, &tmp, td->td_ucred, td);
381 	tmp = fflag & FASYNC;
382 	(void) fo_ioctl(nfp, FIOASYNC, &tmp, td->td_ucred, td);
383 	error = soaccept(so, &sa);
384 	if (error != 0)
385 		goto noconnection;
386 	if (sa == NULL) {
387 		if (name)
388 			*namelen = 0;
389 		goto done;
390 	}
391 	AUDIT_ARG_SOCKADDR(td, AT_FDCWD, sa);
392 	if (name) {
393 		/* check sa_len before it is destroyed */
394 		if (*namelen > sa->sa_len)
395 			*namelen = sa->sa_len;
396 #ifdef KTRACE
397 		if (KTRPOINT(td, KTR_STRUCT))
398 			ktrsockaddr(sa);
399 #endif
400 		*name = sa;
401 		sa = NULL;
402 	}
403 noconnection:
404 	free(sa, M_SONAME);
405 
406 	/*
407 	 * close the new descriptor, assuming someone hasn't ripped it
408 	 * out from under us.
409 	 */
410 	if (error != 0)
411 		fdclose(td, nfp, fd);
412 
413 	/*
414 	 * Release explicitly held references before returning.  We return
415 	 * a reference on nfp to the caller on success if they request it.
416 	 */
417 done:
418 	if (nfp == NULL)
419 		filecaps_free(&fcaps);
420 	if (fp != NULL) {
421 		if (error == 0) {
422 			*fp = nfp;
423 			nfp = NULL;
424 		} else
425 			*fp = NULL;
426 	}
427 	if (nfp != NULL)
428 		fdrop(nfp, td);
429 	fdrop(headfp, td);
430 	return (error);
431 }
432 
433 int
434 sys_accept(td, uap)
435 	struct thread *td;
436 	struct accept_args *uap;
437 {
438 
439 	return (accept1(td, uap->s, uap->name, uap->anamelen, ACCEPT4_INHERIT));
440 }
441 
442 int
443 sys_accept4(td, uap)
444 	struct thread *td;
445 	struct accept4_args *uap;
446 {
447 
448 	if (uap->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
449 		return (EINVAL);
450 
451 	return (accept1(td, uap->s, uap->name, uap->anamelen, uap->flags));
452 }
453 
454 #ifdef COMPAT_OLDSOCK
455 int
456 oaccept(struct thread *td, struct oaccept_args *uap)
457 {
458 
459 	return (accept1(td, uap->s, uap->name, uap->anamelen,
460 	    ACCEPT4_INHERIT | ACCEPT4_COMPAT));
461 }
462 #endif /* COMPAT_OLDSOCK */
463 
464 int
465 sys_connect(struct thread *td, struct connect_args *uap)
466 {
467 	struct sockaddr *sa;
468 	int error;
469 
470 	error = getsockaddr(&sa, uap->name, uap->namelen);
471 	if (error == 0) {
472 		error = kern_connectat(td, AT_FDCWD, uap->s, sa);
473 		free(sa, M_SONAME);
474 	}
475 	return (error);
476 }
477 
478 int
479 kern_connectat(struct thread *td, int dirfd, int fd, struct sockaddr *sa)
480 {
481 	struct socket *so;
482 	struct file *fp;
483 	int error;
484 
485 #ifdef CAPABILITY_MODE
486 	if (IN_CAPABILITY_MODE(td) && (dirfd == AT_FDCWD))
487 		return (ECAPMODE);
488 #endif
489 
490 	AUDIT_ARG_FD(fd);
491 	AUDIT_ARG_SOCKADDR(td, dirfd, sa);
492 	error = getsock_cap(td, fd, &cap_connect_rights,
493 	    &fp, NULL, NULL);
494 	if (error != 0)
495 		return (error);
496 	so = fp->f_data;
497 	if (so->so_state & SS_ISCONNECTING) {
498 		error = EALREADY;
499 		goto done1;
500 	}
501 #ifdef KTRACE
502 	if (KTRPOINT(td, KTR_STRUCT))
503 		ktrsockaddr(sa);
504 #endif
505 #ifdef MAC
506 	error = mac_socket_check_connect(td->td_ucred, so, sa);
507 	if (error != 0)
508 		goto bad;
509 #endif
510 	error = soconnectat(dirfd, so, sa, td);
511 	if (error != 0)
512 		goto bad;
513 	if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
514 		error = EINPROGRESS;
515 		goto done1;
516 	}
517 	SOCK_LOCK(so);
518 	while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
519 		error = msleep(&so->so_timeo, &so->so_lock, PSOCK | PCATCH,
520 		    "connec", 0);
521 		if (error != 0)
522 			break;
523 	}
524 	if (error == 0) {
525 		error = so->so_error;
526 		so->so_error = 0;
527 	}
528 	SOCK_UNLOCK(so);
529 bad:
530 	if (error == ERESTART)
531 		error = EINTR;
532 done1:
533 	fdrop(fp, td);
534 	return (error);
535 }
536 
537 int
538 sys_connectat(struct thread *td, struct connectat_args *uap)
539 {
540 	struct sockaddr *sa;
541 	int error;
542 
543 	error = getsockaddr(&sa, uap->name, uap->namelen);
544 	if (error == 0) {
545 		error = kern_connectat(td, uap->fd, uap->s, sa);
546 		free(sa, M_SONAME);
547 	}
548 	return (error);
549 }
550 
551 int
552 kern_socketpair(struct thread *td, int domain, int type, int protocol,
553     int *rsv)
554 {
555 	struct file *fp1, *fp2;
556 	struct socket *so1, *so2;
557 	int fd, error, oflag, fflag;
558 
559 	AUDIT_ARG_SOCKET(domain, type, protocol);
560 
561 	oflag = 0;
562 	fflag = 0;
563 	if ((type & SOCK_CLOEXEC) != 0) {
564 		type &= ~SOCK_CLOEXEC;
565 		oflag |= O_CLOEXEC;
566 	}
567 	if ((type & SOCK_NONBLOCK) != 0) {
568 		type &= ~SOCK_NONBLOCK;
569 		fflag |= FNONBLOCK;
570 	}
571 #ifdef MAC
572 	/* We might want to have a separate check for socket pairs. */
573 	error = mac_socket_check_create(td->td_ucred, domain, type,
574 	    protocol);
575 	if (error != 0)
576 		return (error);
577 #endif
578 	error = socreate(domain, &so1, type, protocol, td->td_ucred, td);
579 	if (error != 0)
580 		return (error);
581 	error = socreate(domain, &so2, type, protocol, td->td_ucred, td);
582 	if (error != 0)
583 		goto free1;
584 	/* On success extra reference to `fp1' and 'fp2' is set by falloc. */
585 	error = falloc(td, &fp1, &fd, oflag);
586 	if (error != 0)
587 		goto free2;
588 	rsv[0] = fd;
589 	fp1->f_data = so1;	/* so1 already has ref count */
590 	error = falloc(td, &fp2, &fd, oflag);
591 	if (error != 0)
592 		goto free3;
593 	fp2->f_data = so2;	/* so2 already has ref count */
594 	rsv[1] = fd;
595 	error = soconnect2(so1, so2);
596 	if (error != 0)
597 		goto free4;
598 	if (type == SOCK_DGRAM) {
599 		/*
600 		 * Datagram socket connection is asymmetric.
601 		 */
602 		 error = soconnect2(so2, so1);
603 		 if (error != 0)
604 			goto free4;
605 	} else if (so1->so_proto->pr_flags & PR_CONNREQUIRED) {
606 		struct unpcb *unp, *unp2;
607 		unp = sotounpcb(so1);
608 		unp2 = sotounpcb(so2);
609 		/*
610 		 * No need to lock the unps, because the sockets are brand-new.
611 		 * No other threads can be using them yet
612 		 */
613 		unp_copy_peercred(td, unp, unp2, unp);
614 	}
615 	finit(fp1, FREAD | FWRITE | fflag, DTYPE_SOCKET, fp1->f_data,
616 	    &socketops);
617 	finit(fp2, FREAD | FWRITE | fflag, DTYPE_SOCKET, fp2->f_data,
618 	    &socketops);
619 	if ((fflag & FNONBLOCK) != 0) {
620 		(void) fo_ioctl(fp1, FIONBIO, &fflag, td->td_ucred, td);
621 		(void) fo_ioctl(fp2, FIONBIO, &fflag, td->td_ucred, td);
622 	}
623 	fdrop(fp1, td);
624 	fdrop(fp2, td);
625 	return (0);
626 free4:
627 	fdclose(td, fp2, rsv[1]);
628 	fdrop(fp2, td);
629 free3:
630 	fdclose(td, fp1, rsv[0]);
631 	fdrop(fp1, td);
632 free2:
633 	if (so2 != NULL)
634 		(void)soclose(so2);
635 free1:
636 	if (so1 != NULL)
637 		(void)soclose(so1);
638 	return (error);
639 }
640 
641 int
642 sys_socketpair(struct thread *td, struct socketpair_args *uap)
643 {
644 	int error, sv[2];
645 
646 	error = kern_socketpair(td, uap->domain, uap->type,
647 	    uap->protocol, sv);
648 	if (error != 0)
649 		return (error);
650 	error = copyout(sv, uap->rsv, 2 * sizeof(int));
651 	if (error != 0) {
652 		(void)kern_close(td, sv[0]);
653 		(void)kern_close(td, sv[1]);
654 	}
655 	return (error);
656 }
657 
658 static int
659 sendit(struct thread *td, int s, struct msghdr *mp, int flags)
660 {
661 	struct mbuf *control;
662 	struct sockaddr *to;
663 	int error;
664 
665 #ifdef CAPABILITY_MODE
666 	if (IN_CAPABILITY_MODE(td) && (mp->msg_name != NULL))
667 		return (ECAPMODE);
668 #endif
669 
670 	if (mp->msg_name != NULL) {
671 		error = getsockaddr(&to, mp->msg_name, mp->msg_namelen);
672 		if (error != 0) {
673 			to = NULL;
674 			goto bad;
675 		}
676 		mp->msg_name = to;
677 	} else {
678 		to = NULL;
679 	}
680 
681 	if (mp->msg_control) {
682 		if (mp->msg_controllen < sizeof(struct cmsghdr)
683 #ifdef COMPAT_OLDSOCK
684 		    && (mp->msg_flags != MSG_COMPAT ||
685 		    !SV_PROC_FLAG(td->td_proc, SV_AOUT))
686 #endif
687 		) {
688 			error = EINVAL;
689 			goto bad;
690 		}
691 		error = sockargs(&control, mp->msg_control,
692 		    mp->msg_controllen, MT_CONTROL);
693 		if (error != 0)
694 			goto bad;
695 #ifdef COMPAT_OLDSOCK
696 		if (mp->msg_flags == MSG_COMPAT &&
697 		    SV_PROC_FLAG(td->td_proc, SV_AOUT)) {
698 			struct cmsghdr *cm;
699 
700 			M_PREPEND(control, sizeof(*cm), M_WAITOK);
701 			cm = mtod(control, struct cmsghdr *);
702 			cm->cmsg_len = control->m_len;
703 			cm->cmsg_level = SOL_SOCKET;
704 			cm->cmsg_type = SCM_RIGHTS;
705 		}
706 #endif
707 	} else {
708 		control = NULL;
709 	}
710 
711 	error = kern_sendit(td, s, mp, flags, control, UIO_USERSPACE);
712 
713 bad:
714 	free(to, M_SONAME);
715 	return (error);
716 }
717 
718 int
719 kern_sendit(struct thread *td, int s, struct msghdr *mp, int flags,
720     struct mbuf *control, enum uio_seg segflg)
721 {
722 	struct file *fp;
723 	struct uio auio;
724 	struct iovec *iov;
725 	struct socket *so;
726 	cap_rights_t *rights;
727 #ifdef KTRACE
728 	struct uio *ktruio = NULL;
729 #endif
730 	ssize_t len;
731 	int i, error;
732 
733 	AUDIT_ARG_FD(s);
734 	rights = &cap_send_rights;
735 	if (mp->msg_name != NULL) {
736 		AUDIT_ARG_SOCKADDR(td, AT_FDCWD, mp->msg_name);
737 		rights = &cap_send_connect_rights;
738 	}
739 	error = getsock_cap(td, s, rights, &fp, NULL, NULL);
740 	if (error != 0) {
741 		m_freem(control);
742 		return (error);
743 	}
744 	so = (struct socket *)fp->f_data;
745 
746 #ifdef KTRACE
747 	if (mp->msg_name != NULL && KTRPOINT(td, KTR_STRUCT))
748 		ktrsockaddr(mp->msg_name);
749 #endif
750 #ifdef MAC
751 	if (mp->msg_name != NULL) {
752 		error = mac_socket_check_connect(td->td_ucred, so,
753 		    mp->msg_name);
754 		if (error != 0) {
755 			m_freem(control);
756 			goto bad;
757 		}
758 	}
759 	error = mac_socket_check_send(td->td_ucred, so);
760 	if (error != 0) {
761 		m_freem(control);
762 		goto bad;
763 	}
764 #endif
765 
766 	auio.uio_iov = mp->msg_iov;
767 	auio.uio_iovcnt = mp->msg_iovlen;
768 	auio.uio_segflg = segflg;
769 	auio.uio_rw = UIO_WRITE;
770 	auio.uio_td = td;
771 	auio.uio_offset = 0;			/* XXX */
772 	auio.uio_resid = 0;
773 	iov = mp->msg_iov;
774 	for (i = 0; i < mp->msg_iovlen; i++, iov++) {
775 		if ((auio.uio_resid += iov->iov_len) < 0) {
776 			error = EINVAL;
777 			m_freem(control);
778 			goto bad;
779 		}
780 	}
781 #ifdef KTRACE
782 	if (KTRPOINT(td, KTR_GENIO))
783 		ktruio = cloneuio(&auio);
784 #endif
785 	len = auio.uio_resid;
786 	error = sosend(so, mp->msg_name, &auio, 0, control, flags, td);
787 	if (error != 0) {
788 		if (auio.uio_resid != len && (error == ERESTART ||
789 		    error == EINTR || error == EWOULDBLOCK))
790 			error = 0;
791 		/* Generation of SIGPIPE can be controlled per socket */
792 		if (error == EPIPE && !(so->so_options & SO_NOSIGPIPE) &&
793 		    !(flags & MSG_NOSIGNAL)) {
794 			PROC_LOCK(td->td_proc);
795 			tdsignal(td, SIGPIPE);
796 			PROC_UNLOCK(td->td_proc);
797 		}
798 	}
799 	if (error == 0)
800 		td->td_retval[0] = len - auio.uio_resid;
801 #ifdef KTRACE
802 	if (ktruio != NULL) {
803 		ktruio->uio_resid = td->td_retval[0];
804 		ktrgenio(s, UIO_WRITE, ktruio, error);
805 	}
806 #endif
807 bad:
808 	fdrop(fp, td);
809 	return (error);
810 }
811 
812 int
813 sys_sendto(struct thread *td, struct sendto_args *uap)
814 {
815 	struct msghdr msg;
816 	struct iovec aiov;
817 
818 	msg.msg_name = __DECONST(void *, uap->to);
819 	msg.msg_namelen = uap->tolen;
820 	msg.msg_iov = &aiov;
821 	msg.msg_iovlen = 1;
822 	msg.msg_control = 0;
823 #ifdef COMPAT_OLDSOCK
824 	if (SV_PROC_FLAG(td->td_proc, SV_AOUT))
825 		msg.msg_flags = 0;
826 #endif
827 	aiov.iov_base = __DECONST(void *, uap->buf);
828 	aiov.iov_len = uap->len;
829 	return (sendit(td, uap->s, &msg, uap->flags));
830 }
831 
832 #ifdef COMPAT_OLDSOCK
833 int
834 osend(struct thread *td, struct osend_args *uap)
835 {
836 	struct msghdr msg;
837 	struct iovec aiov;
838 
839 	msg.msg_name = 0;
840 	msg.msg_namelen = 0;
841 	msg.msg_iov = &aiov;
842 	msg.msg_iovlen = 1;
843 	aiov.iov_base = __DECONST(void *, uap->buf);
844 	aiov.iov_len = uap->len;
845 	msg.msg_control = 0;
846 	msg.msg_flags = 0;
847 	return (sendit(td, uap->s, &msg, uap->flags));
848 }
849 
850 int
851 osendmsg(struct thread *td, struct osendmsg_args *uap)
852 {
853 	struct msghdr msg;
854 	struct iovec *iov;
855 	int error;
856 
857 	error = copyin(uap->msg, &msg, sizeof (struct omsghdr));
858 	if (error != 0)
859 		return (error);
860 	error = copyiniov(msg.msg_iov, msg.msg_iovlen, &iov, EMSGSIZE);
861 	if (error != 0)
862 		return (error);
863 	msg.msg_iov = iov;
864 	msg.msg_flags = MSG_COMPAT;
865 	error = sendit(td, uap->s, &msg, uap->flags);
866 	free(iov, M_IOV);
867 	return (error);
868 }
869 #endif
870 
871 int
872 sys_sendmsg(struct thread *td, struct sendmsg_args *uap)
873 {
874 	struct msghdr msg;
875 	struct iovec *iov;
876 	int error;
877 
878 	error = copyin(uap->msg, &msg, sizeof (msg));
879 	if (error != 0)
880 		return (error);
881 	error = copyiniov(msg.msg_iov, msg.msg_iovlen, &iov, EMSGSIZE);
882 	if (error != 0)
883 		return (error);
884 	msg.msg_iov = iov;
885 #ifdef COMPAT_OLDSOCK
886 	if (SV_PROC_FLAG(td->td_proc, SV_AOUT))
887 		msg.msg_flags = 0;
888 #endif
889 	error = sendit(td, uap->s, &msg, uap->flags);
890 	free(iov, M_IOV);
891 	return (error);
892 }
893 
894 int
895 kern_recvit(struct thread *td, int s, struct msghdr *mp, enum uio_seg fromseg,
896     struct mbuf **controlp)
897 {
898 	struct uio auio;
899 	struct iovec *iov;
900 	struct mbuf *control, *m;
901 	caddr_t ctlbuf;
902 	struct file *fp;
903 	struct socket *so;
904 	struct sockaddr *fromsa = NULL;
905 #ifdef KTRACE
906 	struct uio *ktruio = NULL;
907 #endif
908 	ssize_t len;
909 	int error, i;
910 
911 	if (controlp != NULL)
912 		*controlp = NULL;
913 
914 	AUDIT_ARG_FD(s);
915 	error = getsock_cap(td, s, &cap_recv_rights,
916 	    &fp, NULL, NULL);
917 	if (error != 0)
918 		return (error);
919 	so = fp->f_data;
920 
921 #ifdef MAC
922 	error = mac_socket_check_receive(td->td_ucred, so);
923 	if (error != 0) {
924 		fdrop(fp, td);
925 		return (error);
926 	}
927 #endif
928 
929 	auio.uio_iov = mp->msg_iov;
930 	auio.uio_iovcnt = mp->msg_iovlen;
931 	auio.uio_segflg = UIO_USERSPACE;
932 	auio.uio_rw = UIO_READ;
933 	auio.uio_td = td;
934 	auio.uio_offset = 0;			/* XXX */
935 	auio.uio_resid = 0;
936 	iov = mp->msg_iov;
937 	for (i = 0; i < mp->msg_iovlen; i++, iov++) {
938 		if ((auio.uio_resid += iov->iov_len) < 0) {
939 			fdrop(fp, td);
940 			return (EINVAL);
941 		}
942 	}
943 #ifdef KTRACE
944 	if (KTRPOINT(td, KTR_GENIO))
945 		ktruio = cloneuio(&auio);
946 #endif
947 	control = NULL;
948 	len = auio.uio_resid;
949 	error = soreceive(so, &fromsa, &auio, NULL,
950 	    (mp->msg_control || controlp) ? &control : NULL,
951 	    &mp->msg_flags);
952 	if (error != 0) {
953 		if (auio.uio_resid != len && (error == ERESTART ||
954 		    error == EINTR || error == EWOULDBLOCK))
955 			error = 0;
956 	}
957 	if (fromsa != NULL)
958 		AUDIT_ARG_SOCKADDR(td, AT_FDCWD, fromsa);
959 #ifdef KTRACE
960 	if (ktruio != NULL) {
961 		ktruio->uio_resid = len - auio.uio_resid;
962 		ktrgenio(s, UIO_READ, ktruio, error);
963 	}
964 #endif
965 	if (error != 0)
966 		goto out;
967 	td->td_retval[0] = len - auio.uio_resid;
968 	if (mp->msg_name) {
969 		len = mp->msg_namelen;
970 		if (len <= 0 || fromsa == NULL)
971 			len = 0;
972 		else {
973 			/* save sa_len before it is destroyed by MSG_COMPAT */
974 			len = MIN(len, fromsa->sa_len);
975 #ifdef COMPAT_OLDSOCK
976 			if ((mp->msg_flags & MSG_COMPAT) != 0 &&
977 			    SV_PROC_FLAG(td->td_proc, SV_AOUT))
978 				((struct osockaddr *)fromsa)->sa_family =
979 				    fromsa->sa_family;
980 #endif
981 			if (fromseg == UIO_USERSPACE) {
982 				error = copyout(fromsa, mp->msg_name,
983 				    (unsigned)len);
984 				if (error != 0)
985 					goto out;
986 			} else
987 				bcopy(fromsa, mp->msg_name, len);
988 		}
989 		mp->msg_namelen = len;
990 	}
991 	if (mp->msg_control && controlp == NULL) {
992 #ifdef COMPAT_OLDSOCK
993 		/*
994 		 * We assume that old recvmsg calls won't receive access
995 		 * rights and other control info, esp. as control info
996 		 * is always optional and those options didn't exist in 4.3.
997 		 * If we receive rights, trim the cmsghdr; anything else
998 		 * is tossed.
999 		 */
1000 		if (control && (mp->msg_flags & MSG_COMPAT) != 0 &&
1001 		    SV_PROC_FLAG(td->td_proc, SV_AOUT)) {
1002 			if (mtod(control, struct cmsghdr *)->cmsg_level !=
1003 			    SOL_SOCKET ||
1004 			    mtod(control, struct cmsghdr *)->cmsg_type !=
1005 			    SCM_RIGHTS) {
1006 				mp->msg_controllen = 0;
1007 				goto out;
1008 			}
1009 			control->m_len -= sizeof (struct cmsghdr);
1010 			control->m_data += sizeof (struct cmsghdr);
1011 		}
1012 #endif
1013 		ctlbuf = mp->msg_control;
1014 		len = mp->msg_controllen;
1015 		mp->msg_controllen = 0;
1016 		for (m = control; m != NULL && len >= m->m_len; m = m->m_next) {
1017 			if ((error = copyout(mtod(m, caddr_t), ctlbuf,
1018 			    m->m_len)) != 0)
1019 				goto out;
1020 
1021 			ctlbuf += m->m_len;
1022 			len -= m->m_len;
1023 			mp->msg_controllen += m->m_len;
1024 		}
1025 		if (m != NULL) {
1026 			mp->msg_flags |= MSG_CTRUNC;
1027 			m_dispose_extcontrolm(m);
1028 		}
1029 	}
1030 out:
1031 	fdrop(fp, td);
1032 #ifdef KTRACE
1033 	if (fromsa && KTRPOINT(td, KTR_STRUCT))
1034 		ktrsockaddr(fromsa);
1035 #endif
1036 	free(fromsa, M_SONAME);
1037 
1038 	if (error == 0 && controlp != NULL)
1039 		*controlp = control;
1040 	else if (control != NULL) {
1041 		if (error != 0)
1042 			m_dispose_extcontrolm(control);
1043 		m_freem(control);
1044 	}
1045 
1046 	return (error);
1047 }
1048 
1049 static int
1050 recvit(struct thread *td, int s, struct msghdr *mp, void *namelenp)
1051 {
1052 	int error;
1053 
1054 	error = kern_recvit(td, s, mp, UIO_USERSPACE, NULL);
1055 	if (error != 0)
1056 		return (error);
1057 	if (namelenp != NULL) {
1058 		error = copyout(&mp->msg_namelen, namelenp, sizeof (socklen_t));
1059 #ifdef COMPAT_OLDSOCK
1060 		if ((mp->msg_flags & MSG_COMPAT) != 0 &&
1061 		    SV_PROC_FLAG(td->td_proc, SV_AOUT))
1062 			error = 0;	/* old recvfrom didn't check */
1063 #endif
1064 	}
1065 	return (error);
1066 }
1067 
1068 static int
1069 kern_recvfrom(struct thread *td, int s, void *buf, size_t len, int flags,
1070     struct sockaddr *from, socklen_t *fromlenaddr)
1071 {
1072 	struct msghdr msg;
1073 	struct iovec aiov;
1074 	int error;
1075 
1076 	if (fromlenaddr != NULL) {
1077 		error = copyin(fromlenaddr, &msg.msg_namelen,
1078 		    sizeof (msg.msg_namelen));
1079 		if (error != 0)
1080 			goto done2;
1081 	} else {
1082 		msg.msg_namelen = 0;
1083 	}
1084 	msg.msg_name = from;
1085 	msg.msg_iov = &aiov;
1086 	msg.msg_iovlen = 1;
1087 	aiov.iov_base = buf;
1088 	aiov.iov_len = len;
1089 	msg.msg_control = 0;
1090 	msg.msg_flags = flags;
1091 	error = recvit(td, s, &msg, fromlenaddr);
1092 done2:
1093 	return (error);
1094 }
1095 
1096 int
1097 sys_recvfrom(struct thread *td, struct recvfrom_args *uap)
1098 {
1099 	return (kern_recvfrom(td, uap->s, uap->buf, uap->len,
1100 	    uap->flags, uap->from, uap->fromlenaddr));
1101 }
1102 
1103 
1104 #ifdef COMPAT_OLDSOCK
1105 int
1106 orecvfrom(struct thread *td, struct orecvfrom_args *uap)
1107 {
1108 	return (kern_recvfrom(td, uap->s, uap->buf, uap->len,
1109 	    uap->flags | MSG_COMPAT, uap->from, uap->fromlenaddr));
1110 }
1111 #endif
1112 
1113 #ifdef COMPAT_OLDSOCK
1114 int
1115 orecv(struct thread *td, struct orecv_args *uap)
1116 {
1117 	struct msghdr msg;
1118 	struct iovec aiov;
1119 
1120 	msg.msg_name = 0;
1121 	msg.msg_namelen = 0;
1122 	msg.msg_iov = &aiov;
1123 	msg.msg_iovlen = 1;
1124 	aiov.iov_base = uap->buf;
1125 	aiov.iov_len = uap->len;
1126 	msg.msg_control = 0;
1127 	msg.msg_flags = uap->flags;
1128 	return (recvit(td, uap->s, &msg, NULL));
1129 }
1130 
1131 /*
1132  * Old recvmsg.  This code takes advantage of the fact that the old msghdr
1133  * overlays the new one, missing only the flags, and with the (old) access
1134  * rights where the control fields are now.
1135  */
1136 int
1137 orecvmsg(struct thread *td, struct orecvmsg_args *uap)
1138 {
1139 	struct msghdr msg;
1140 	struct iovec *iov;
1141 	int error;
1142 
1143 	error = copyin(uap->msg, &msg, sizeof (struct omsghdr));
1144 	if (error != 0)
1145 		return (error);
1146 	error = copyiniov(msg.msg_iov, msg.msg_iovlen, &iov, EMSGSIZE);
1147 	if (error != 0)
1148 		return (error);
1149 	msg.msg_flags = uap->flags | MSG_COMPAT;
1150 	msg.msg_iov = iov;
1151 	error = recvit(td, uap->s, &msg, &uap->msg->msg_namelen);
1152 	if (msg.msg_controllen && error == 0)
1153 		error = copyout(&msg.msg_controllen,
1154 		    &uap->msg->msg_accrightslen, sizeof (int));
1155 	free(iov, M_IOV);
1156 	return (error);
1157 }
1158 #endif
1159 
1160 int
1161 sys_recvmsg(struct thread *td, struct recvmsg_args *uap)
1162 {
1163 	struct msghdr msg;
1164 	struct iovec *uiov, *iov;
1165 	int error;
1166 
1167 	error = copyin(uap->msg, &msg, sizeof (msg));
1168 	if (error != 0)
1169 		return (error);
1170 	error = copyiniov(msg.msg_iov, msg.msg_iovlen, &iov, EMSGSIZE);
1171 	if (error != 0)
1172 		return (error);
1173 	msg.msg_flags = uap->flags;
1174 #ifdef COMPAT_OLDSOCK
1175 	if (SV_PROC_FLAG(td->td_proc, SV_AOUT))
1176 		msg.msg_flags &= ~MSG_COMPAT;
1177 #endif
1178 	uiov = msg.msg_iov;
1179 	msg.msg_iov = iov;
1180 	error = recvit(td, uap->s, &msg, NULL);
1181 	if (error == 0) {
1182 		msg.msg_iov = uiov;
1183 		error = copyout(&msg, uap->msg, sizeof(msg));
1184 	}
1185 	free(iov, M_IOV);
1186 	return (error);
1187 }
1188 
1189 int
1190 sys_shutdown(struct thread *td, struct shutdown_args *uap)
1191 {
1192 
1193 	return (kern_shutdown(td, uap->s, uap->how));
1194 }
1195 
1196 int
1197 kern_shutdown(struct thread *td, int s, int how)
1198 {
1199 	struct socket *so;
1200 	struct file *fp;
1201 	int error;
1202 
1203 	AUDIT_ARG_FD(s);
1204 	error = getsock_cap(td, s, &cap_shutdown_rights,
1205 	    &fp, NULL, NULL);
1206 	if (error == 0) {
1207 		so = fp->f_data;
1208 		error = soshutdown(so, how);
1209 		/*
1210 		 * Previous versions did not return ENOTCONN, but 0 in
1211 		 * case the socket was not connected. Some important
1212 		 * programs like syslogd up to r279016, 2015-02-19,
1213 		 * still depend on this behavior.
1214 		 */
1215 		if (error == ENOTCONN &&
1216 		    td->td_proc->p_osrel < P_OSREL_SHUTDOWN_ENOTCONN)
1217 			error = 0;
1218 		fdrop(fp, td);
1219 	}
1220 	return (error);
1221 }
1222 
1223 int
1224 sys_setsockopt(struct thread *td, struct setsockopt_args *uap)
1225 {
1226 
1227 	return (kern_setsockopt(td, uap->s, uap->level, uap->name,
1228 	    uap->val, UIO_USERSPACE, uap->valsize));
1229 }
1230 
1231 int
1232 kern_setsockopt(struct thread *td, int s, int level, int name, const void *val,
1233     enum uio_seg valseg, socklen_t valsize)
1234 {
1235 	struct socket *so;
1236 	struct file *fp;
1237 	struct sockopt sopt;
1238 	int error;
1239 
1240 	if (val == NULL && valsize != 0)
1241 		return (EFAULT);
1242 	if ((int)valsize < 0)
1243 		return (EINVAL);
1244 
1245 	sopt.sopt_dir = SOPT_SET;
1246 	sopt.sopt_level = level;
1247 	sopt.sopt_name = name;
1248 	sopt.sopt_val = __DECONST(void *, val);
1249 	sopt.sopt_valsize = valsize;
1250 	switch (valseg) {
1251 	case UIO_USERSPACE:
1252 		sopt.sopt_td = td;
1253 		break;
1254 	case UIO_SYSSPACE:
1255 		sopt.sopt_td = NULL;
1256 		break;
1257 	default:
1258 		panic("kern_setsockopt called with bad valseg");
1259 	}
1260 
1261 	AUDIT_ARG_FD(s);
1262 	error = getsock_cap(td, s, &cap_setsockopt_rights,
1263 	    &fp, NULL, NULL);
1264 	if (error == 0) {
1265 		so = fp->f_data;
1266 		error = sosetopt(so, &sopt);
1267 		fdrop(fp, td);
1268 	}
1269 	return(error);
1270 }
1271 
1272 int
1273 sys_getsockopt(struct thread *td, struct getsockopt_args *uap)
1274 {
1275 	socklen_t valsize;
1276 	int error;
1277 
1278 	if (uap->val) {
1279 		error = copyin(uap->avalsize, &valsize, sizeof (valsize));
1280 		if (error != 0)
1281 			return (error);
1282 	}
1283 
1284 	error = kern_getsockopt(td, uap->s, uap->level, uap->name,
1285 	    uap->val, UIO_USERSPACE, &valsize);
1286 
1287 	if (error == 0)
1288 		error = copyout(&valsize, uap->avalsize, sizeof (valsize));
1289 	return (error);
1290 }
1291 
1292 /*
1293  * Kernel version of getsockopt.
1294  * optval can be a userland or userspace. optlen is always a kernel pointer.
1295  */
1296 int
1297 kern_getsockopt(struct thread *td, int s, int level, int name, void *val,
1298     enum uio_seg valseg, socklen_t *valsize)
1299 {
1300 	struct socket *so;
1301 	struct file *fp;
1302 	struct sockopt sopt;
1303 	int error;
1304 
1305 	if (val == NULL)
1306 		*valsize = 0;
1307 	if ((int)*valsize < 0)
1308 		return (EINVAL);
1309 
1310 	sopt.sopt_dir = SOPT_GET;
1311 	sopt.sopt_level = level;
1312 	sopt.sopt_name = name;
1313 	sopt.sopt_val = val;
1314 	sopt.sopt_valsize = (size_t)*valsize; /* checked non-negative above */
1315 	switch (valseg) {
1316 	case UIO_USERSPACE:
1317 		sopt.sopt_td = td;
1318 		break;
1319 	case UIO_SYSSPACE:
1320 		sopt.sopt_td = NULL;
1321 		break;
1322 	default:
1323 		panic("kern_getsockopt called with bad valseg");
1324 	}
1325 
1326 	AUDIT_ARG_FD(s);
1327 	error = getsock_cap(td, s, &cap_getsockopt_rights,
1328 	    &fp, NULL, NULL);
1329 	if (error == 0) {
1330 		so = fp->f_data;
1331 		error = sogetopt(so, &sopt);
1332 		*valsize = sopt.sopt_valsize;
1333 		fdrop(fp, td);
1334 	}
1335 	return (error);
1336 }
1337 
1338 static int
1339 user_getsockname(struct thread *td, int fdes, struct sockaddr *asa,
1340     socklen_t *alen, bool compat)
1341 {
1342 	struct sockaddr *sa;
1343 	socklen_t len;
1344 	int error;
1345 
1346 	error = copyin(alen, &len, sizeof(len));
1347 	if (error != 0)
1348 		return (error);
1349 
1350 	error = kern_getsockname(td, fdes, &sa, &len);
1351 	if (error != 0)
1352 		return (error);
1353 
1354 	if (len != 0) {
1355 #ifdef COMPAT_OLDSOCK
1356 		if (compat && SV_PROC_FLAG(td->td_proc, SV_AOUT))
1357 			((struct osockaddr *)sa)->sa_family = sa->sa_family;
1358 #endif
1359 		error = copyout(sa, asa, len);
1360 	}
1361 	free(sa, M_SONAME);
1362 	if (error == 0)
1363 		error = copyout(&len, alen, sizeof(len));
1364 	return (error);
1365 }
1366 
1367 int
1368 kern_getsockname(struct thread *td, int fd, struct sockaddr **sa,
1369     socklen_t *alen)
1370 {
1371 	struct socket *so;
1372 	struct file *fp;
1373 	socklen_t len;
1374 	int error;
1375 
1376 	AUDIT_ARG_FD(fd);
1377 	error = getsock_cap(td, fd, &cap_getsockname_rights,
1378 	    &fp, NULL, NULL);
1379 	if (error != 0)
1380 		return (error);
1381 	so = fp->f_data;
1382 	*sa = NULL;
1383 	CURVNET_SET(so->so_vnet);
1384 	error = (*so->so_proto->pr_usrreqs->pru_sockaddr)(so, sa);
1385 	CURVNET_RESTORE();
1386 	if (error != 0)
1387 		goto bad;
1388 	if (*sa == NULL)
1389 		len = 0;
1390 	else
1391 		len = MIN(*alen, (*sa)->sa_len);
1392 	*alen = len;
1393 #ifdef KTRACE
1394 	if (KTRPOINT(td, KTR_STRUCT))
1395 		ktrsockaddr(*sa);
1396 #endif
1397 bad:
1398 	fdrop(fp, td);
1399 	if (error != 0 && *sa != NULL) {
1400 		free(*sa, M_SONAME);
1401 		*sa = NULL;
1402 	}
1403 	return (error);
1404 }
1405 
1406 int
1407 sys_getsockname(struct thread *td, struct getsockname_args *uap)
1408 {
1409 	return (user_getsockname(td, uap->fdes, uap->asa, uap->alen, false));
1410 }
1411 
1412 #ifdef COMPAT_OLDSOCK
1413 int
1414 ogetsockname(struct thread *td, struct ogetsockname_args *uap)
1415 {
1416 	return (user_getsockname(td, uap->fdes, uap->asa, uap->alen, true));
1417 }
1418 #endif /* COMPAT_OLDSOCK */
1419 
1420 static int
1421 user_getpeername(struct thread *td, int fdes, struct sockaddr *asa,
1422     socklen_t *alen, int compat)
1423 {
1424 	struct sockaddr *sa;
1425 	socklen_t len;
1426 	int error;
1427 
1428 	error = copyin(alen, &len, sizeof (len));
1429 	if (error != 0)
1430 		return (error);
1431 
1432 	error = kern_getpeername(td, fdes, &sa, &len);
1433 	if (error != 0)
1434 		return (error);
1435 
1436 	if (len != 0) {
1437 #ifdef COMPAT_OLDSOCK
1438 		if (compat && SV_PROC_FLAG(td->td_proc, SV_AOUT))
1439 			((struct osockaddr *)sa)->sa_family = sa->sa_family;
1440 #endif
1441 		error = copyout(sa, asa, len);
1442 	}
1443 	free(sa, M_SONAME);
1444 	if (error == 0)
1445 		error = copyout(&len, alen, sizeof(len));
1446 	return (error);
1447 }
1448 
1449 int
1450 kern_getpeername(struct thread *td, int fd, struct sockaddr **sa,
1451     socklen_t *alen)
1452 {
1453 	struct socket *so;
1454 	struct file *fp;
1455 	socklen_t len;
1456 	int error;
1457 
1458 	AUDIT_ARG_FD(fd);
1459 	error = getsock_cap(td, fd, &cap_getpeername_rights,
1460 	    &fp, NULL, NULL);
1461 	if (error != 0)
1462 		return (error);
1463 	so = fp->f_data;
1464 	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
1465 		error = ENOTCONN;
1466 		goto done;
1467 	}
1468 	*sa = NULL;
1469 	CURVNET_SET(so->so_vnet);
1470 	error = (*so->so_proto->pr_usrreqs->pru_peeraddr)(so, sa);
1471 	CURVNET_RESTORE();
1472 	if (error != 0)
1473 		goto bad;
1474 	if (*sa == NULL)
1475 		len = 0;
1476 	else
1477 		len = MIN(*alen, (*sa)->sa_len);
1478 	*alen = len;
1479 #ifdef KTRACE
1480 	if (KTRPOINT(td, KTR_STRUCT))
1481 		ktrsockaddr(*sa);
1482 #endif
1483 bad:
1484 	if (error != 0 && *sa != NULL) {
1485 		free(*sa, M_SONAME);
1486 		*sa = NULL;
1487 	}
1488 done:
1489 	fdrop(fp, td);
1490 	return (error);
1491 }
1492 
1493 int
1494 sys_getpeername(struct thread *td, struct getpeername_args *uap)
1495 {
1496 	return (user_getpeername(td, uap->fdes, uap->asa, uap->alen, 0));
1497 }
1498 
1499 #ifdef COMPAT_OLDSOCK
1500 int
1501 ogetpeername(struct thread *td, struct ogetpeername_args *uap)
1502 {
1503 	return (user_getpeername(td, uap->fdes, uap->asa, uap->alen, 1));
1504 }
1505 #endif /* COMPAT_OLDSOCK */
1506 
1507 static int
1508 sockargs(struct mbuf **mp, char *buf, socklen_t buflen, int type)
1509 {
1510 	struct sockaddr *sa;
1511 	struct mbuf *m;
1512 	int error;
1513 
1514 	if (buflen > MLEN) {
1515 #ifdef COMPAT_OLDSOCK
1516 		if (type == MT_SONAME && buflen <= 112 &&
1517 		    SV_CURPROC_FLAG(SV_AOUT))
1518 			buflen = MLEN;		/* unix domain compat. hack */
1519 		else
1520 #endif
1521 			if (buflen > MCLBYTES)
1522 				return (EINVAL);
1523 	}
1524 	m = m_get2(buflen, M_WAITOK, type, 0);
1525 	m->m_len = buflen;
1526 	error = copyin(buf, mtod(m, void *), buflen);
1527 	if (error != 0)
1528 		(void) m_free(m);
1529 	else {
1530 		*mp = m;
1531 		if (type == MT_SONAME) {
1532 			sa = mtod(m, struct sockaddr *);
1533 
1534 #if defined(COMPAT_OLDSOCK) && BYTE_ORDER != BIG_ENDIAN
1535 			if (sa->sa_family == 0 && sa->sa_len < AF_MAX &&
1536 			    SV_CURPROC_FLAG(SV_AOUT))
1537 				sa->sa_family = sa->sa_len;
1538 #endif
1539 			sa->sa_len = buflen;
1540 		}
1541 	}
1542 	return (error);
1543 }
1544 
1545 int
1546 getsockaddr(struct sockaddr **namp, const struct sockaddr *uaddr, size_t len)
1547 {
1548 	struct sockaddr *sa;
1549 	int error;
1550 
1551 	if (len > SOCK_MAXADDRLEN)
1552 		return (ENAMETOOLONG);
1553 	if (len < offsetof(struct sockaddr, sa_data[0]))
1554 		return (EINVAL);
1555 	sa = malloc(len, M_SONAME, M_WAITOK);
1556 	error = copyin(uaddr, sa, len);
1557 	if (error != 0) {
1558 		free(sa, M_SONAME);
1559 	} else {
1560 #if defined(COMPAT_OLDSOCK) && BYTE_ORDER != BIG_ENDIAN
1561 		if (sa->sa_family == 0 && sa->sa_len < AF_MAX &&
1562 		    SV_CURPROC_FLAG(SV_AOUT))
1563 			sa->sa_family = sa->sa_len;
1564 #endif
1565 		sa->sa_len = len;
1566 		*namp = sa;
1567 	}
1568 	return (error);
1569 }
1570 
1571 /*
1572  * Dispose of externalized rights from an SCM_RIGHTS message.  This function
1573  * should be used in error or truncation cases to avoid leaking file descriptors
1574  * into the recipient's (the current thread's) table.
1575  */
1576 void
1577 m_dispose_extcontrolm(struct mbuf *m)
1578 {
1579 	struct cmsghdr *cm;
1580 	struct file *fp;
1581 	struct thread *td;
1582 	socklen_t clen, datalen;
1583 	int error, fd, *fds, nfd;
1584 
1585 	td = curthread;
1586 	for (; m != NULL; m = m->m_next) {
1587 		if (m->m_type != MT_EXTCONTROL)
1588 			continue;
1589 		cm = mtod(m, struct cmsghdr *);
1590 		clen = m->m_len;
1591 		while (clen > 0) {
1592 			if (clen < sizeof(*cm))
1593 				panic("%s: truncated mbuf %p", __func__, m);
1594 			datalen = CMSG_SPACE(cm->cmsg_len - CMSG_SPACE(0));
1595 			if (clen < datalen)
1596 				panic("%s: truncated mbuf %p", __func__, m);
1597 
1598 			if (cm->cmsg_level == SOL_SOCKET &&
1599 			    cm->cmsg_type == SCM_RIGHTS) {
1600 				fds = (int *)CMSG_DATA(cm);
1601 				nfd = (cm->cmsg_len - CMSG_SPACE(0)) /
1602 				    sizeof(int);
1603 
1604 				while (nfd-- > 0) {
1605 					fd = *fds++;
1606 					error = fget(td, fd, &cap_no_rights,
1607 					    &fp);
1608 					if (error == 0) {
1609 						fdclose(td, fp, fd);
1610 						fdrop(fp, td);
1611 					}
1612 				}
1613 			}
1614 			clen -= datalen;
1615 			cm = (struct cmsghdr *)((uint8_t *)cm + datalen);
1616 		}
1617 		m_chtype(m, MT_CONTROL);
1618 	}
1619 }
1620