1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1995 Søren Schmidt
5  * 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  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 /* XXX we use functions that might not exist. */
33 #include "opt_compat.h"
34 #include "opt_inet6.h"
35 
36 #include <sys/param.h>
37 #include <sys/proc.h>
38 #include <sys/systm.h>
39 #include <sys/sysproto.h>
40 #include <sys/capsicum.h>
41 #include <sys/fcntl.h>
42 #include <sys/file.h>
43 #include <sys/limits.h>
44 #include <sys/lock.h>
45 #include <sys/malloc.h>
46 #include <sys/mutex.h>
47 #include <sys/mbuf.h>
48 #include <sys/socket.h>
49 #include <sys/socketvar.h>
50 #include <sys/syscallsubr.h>
51 #include <sys/uio.h>
52 #include <sys/stat.h>
53 #include <sys/syslog.h>
54 #include <sys/un.h>
55 #include <sys/unistd.h>
56 
57 #include <security/audit/audit.h>
58 
59 #include <net/if.h>
60 #include <net/vnet.h>
61 #include <netinet/in.h>
62 #include <netinet/in_systm.h>
63 #include <netinet/ip.h>
64 #include <netinet/tcp.h>
65 #ifdef INET6
66 #include <netinet/ip6.h>
67 #include <netinet6/ip6_var.h>
68 #endif
69 
70 #ifdef COMPAT_LINUX32
71 #include <machine/../linux32/linux.h>
72 #include <machine/../linux32/linux32_proto.h>
73 #else
74 #include <machine/../linux/linux.h>
75 #include <machine/../linux/linux_proto.h>
76 #endif
77 #include <compat/linux/linux_common.h>
78 #include <compat/linux/linux_file.h>
79 #include <compat/linux/linux_mib.h>
80 #include <compat/linux/linux_socket.h>
81 #include <compat/linux/linux_timer.h>
82 #include <compat/linux/linux_util.h>
83 
84 static int linux_sendmsg_common(struct thread *, l_int, struct l_msghdr *,
85 					l_uint);
86 static int linux_recvmsg_common(struct thread *, l_int, struct l_msghdr *,
87 					l_uint, struct msghdr *);
88 static int linux_set_socket_flags(int, int *);
89 
90 
91 static int
92 linux_to_bsd_sockopt_level(int level)
93 {
94 
95 	switch (level) {
96 	case LINUX_SOL_SOCKET:
97 		return (SOL_SOCKET);
98 	}
99 	return (level);
100 }
101 
102 static int
103 bsd_to_linux_sockopt_level(int level)
104 {
105 
106 	switch (level) {
107 	case SOL_SOCKET:
108 		return (LINUX_SOL_SOCKET);
109 	}
110 	return (level);
111 }
112 
113 static int
114 linux_to_bsd_ip_sockopt(int opt)
115 {
116 
117 	switch (opt) {
118 	case LINUX_IP_TOS:
119 		return (IP_TOS);
120 	case LINUX_IP_TTL:
121 		return (IP_TTL);
122 	case LINUX_IP_OPTIONS:
123 		return (IP_OPTIONS);
124 	case LINUX_IP_MULTICAST_IF:
125 		return (IP_MULTICAST_IF);
126 	case LINUX_IP_MULTICAST_TTL:
127 		return (IP_MULTICAST_TTL);
128 	case LINUX_IP_MULTICAST_LOOP:
129 		return (IP_MULTICAST_LOOP);
130 	case LINUX_IP_ADD_MEMBERSHIP:
131 		return (IP_ADD_MEMBERSHIP);
132 	case LINUX_IP_DROP_MEMBERSHIP:
133 		return (IP_DROP_MEMBERSHIP);
134 	case LINUX_IP_HDRINCL:
135 		return (IP_HDRINCL);
136 	}
137 	return (-1);
138 }
139 
140 static int
141 linux_to_bsd_ip6_sockopt(int opt)
142 {
143 
144 	switch (opt) {
145 	case LINUX_IPV6_NEXTHOP:
146 		return (IPV6_NEXTHOP);
147 	case LINUX_IPV6_UNICAST_HOPS:
148 		return (IPV6_UNICAST_HOPS);
149 	case LINUX_IPV6_MULTICAST_IF:
150 		return (IPV6_MULTICAST_IF);
151 	case LINUX_IPV6_MULTICAST_HOPS:
152 		return (IPV6_MULTICAST_HOPS);
153 	case LINUX_IPV6_MULTICAST_LOOP:
154 		return (IPV6_MULTICAST_LOOP);
155 	case LINUX_IPV6_ADD_MEMBERSHIP:
156 		return (IPV6_JOIN_GROUP);
157 	case LINUX_IPV6_DROP_MEMBERSHIP:
158 		return (IPV6_LEAVE_GROUP);
159 	case LINUX_IPV6_V6ONLY:
160 		return (IPV6_V6ONLY);
161 	case LINUX_IPV6_DONTFRAG:
162 		return (IPV6_DONTFRAG);
163 #if 0
164 	case LINUX_IPV6_CHECKSUM:
165 		return (IPV6_CHECKSUM);
166 	case LINUX_IPV6_RECVPKTINFO:
167 		return (IPV6_RECVPKTINFO);
168 	case LINUX_IPV6_PKTINFO:
169 		return (IPV6_PKTINFO);
170 	case LINUX_IPV6_RECVHOPLIMIT:
171 		return (IPV6_RECVHOPLIMIT);
172 	case LINUX_IPV6_HOPLIMIT:
173 		return (IPV6_HOPLIMIT);
174 	case LINUX_IPV6_RECVHOPOPTS:
175 		return (IPV6_RECVHOPOPTS);
176 	case LINUX_IPV6_HOPOPTS:
177 		return (IPV6_HOPOPTS);
178 	case LINUX_IPV6_RTHDRDSTOPTS:
179 		return (IPV6_RTHDRDSTOPTS);
180 	case LINUX_IPV6_RECVRTHDR:
181 		return (IPV6_RECVRTHDR);
182 	case LINUX_IPV6_RTHDR:
183 		return (IPV6_RTHDR);
184 	case LINUX_IPV6_RECVDSTOPTS:
185 		return (IPV6_RECVDSTOPTS);
186 	case LINUX_IPV6_DSTOPTS:
187 		return (IPV6_DSTOPTS);
188 	case LINUX_IPV6_RECVPATHMTU:
189 		return (IPV6_RECVPATHMTU);
190 	case LINUX_IPV6_PATHMTU:
191 		return (IPV6_PATHMTU);
192 #endif
193 	}
194 	return (-1);
195 }
196 
197 static int
198 linux_to_bsd_so_sockopt(int opt)
199 {
200 
201 	switch (opt) {
202 	case LINUX_SO_DEBUG:
203 		return (SO_DEBUG);
204 	case LINUX_SO_REUSEADDR:
205 		return (SO_REUSEADDR);
206 	case LINUX_SO_TYPE:
207 		return (SO_TYPE);
208 	case LINUX_SO_ERROR:
209 		return (SO_ERROR);
210 	case LINUX_SO_DONTROUTE:
211 		return (SO_DONTROUTE);
212 	case LINUX_SO_BROADCAST:
213 		return (SO_BROADCAST);
214 	case LINUX_SO_SNDBUF:
215 	case LINUX_SO_SNDBUFFORCE:
216 		return (SO_SNDBUF);
217 	case LINUX_SO_RCVBUF:
218 	case LINUX_SO_RCVBUFFORCE:
219 		return (SO_RCVBUF);
220 	case LINUX_SO_KEEPALIVE:
221 		return (SO_KEEPALIVE);
222 	case LINUX_SO_OOBINLINE:
223 		return (SO_OOBINLINE);
224 	case LINUX_SO_LINGER:
225 		return (SO_LINGER);
226 	case LINUX_SO_REUSEPORT:
227 		return (SO_REUSEPORT_LB);
228 	case LINUX_SO_PEERCRED:
229 		return (LOCAL_PEERCRED);
230 	case LINUX_SO_RCVLOWAT:
231 		return (SO_RCVLOWAT);
232 	case LINUX_SO_SNDLOWAT:
233 		return (SO_SNDLOWAT);
234 	case LINUX_SO_RCVTIMEO:
235 		return (SO_RCVTIMEO);
236 	case LINUX_SO_SNDTIMEO:
237 		return (SO_SNDTIMEO);
238 	case LINUX_SO_TIMESTAMP:
239 		return (SO_TIMESTAMP);
240 	case LINUX_SO_ACCEPTCONN:
241 		return (SO_ACCEPTCONN);
242 	}
243 	return (-1);
244 }
245 
246 static int
247 linux_to_bsd_tcp_sockopt(int opt)
248 {
249 
250 	switch (opt) {
251 	case LINUX_TCP_NODELAY:
252 		return (TCP_NODELAY);
253 	case LINUX_TCP_MAXSEG:
254 		return (TCP_MAXSEG);
255 	case LINUX_TCP_CORK:
256 		return (TCP_NOPUSH);
257 	case LINUX_TCP_KEEPIDLE:
258 		return (TCP_KEEPIDLE);
259 	case LINUX_TCP_KEEPINTVL:
260 		return (TCP_KEEPINTVL);
261 	case LINUX_TCP_KEEPCNT:
262 		return (TCP_KEEPCNT);
263 	case LINUX_TCP_MD5SIG:
264 		return (TCP_MD5SIG);
265 	}
266 	return (-1);
267 }
268 
269 static int
270 linux_to_bsd_msg_flags(int flags)
271 {
272 	int ret_flags = 0;
273 
274 	if (flags & LINUX_MSG_OOB)
275 		ret_flags |= MSG_OOB;
276 	if (flags & LINUX_MSG_PEEK)
277 		ret_flags |= MSG_PEEK;
278 	if (flags & LINUX_MSG_DONTROUTE)
279 		ret_flags |= MSG_DONTROUTE;
280 	if (flags & LINUX_MSG_CTRUNC)
281 		ret_flags |= MSG_CTRUNC;
282 	if (flags & LINUX_MSG_TRUNC)
283 		ret_flags |= MSG_TRUNC;
284 	if (flags & LINUX_MSG_DONTWAIT)
285 		ret_flags |= MSG_DONTWAIT;
286 	if (flags & LINUX_MSG_EOR)
287 		ret_flags |= MSG_EOR;
288 	if (flags & LINUX_MSG_WAITALL)
289 		ret_flags |= MSG_WAITALL;
290 	if (flags & LINUX_MSG_NOSIGNAL)
291 		ret_flags |= MSG_NOSIGNAL;
292 #if 0 /* not handled */
293 	if (flags & LINUX_MSG_PROXY)
294 		;
295 	if (flags & LINUX_MSG_FIN)
296 		;
297 	if (flags & LINUX_MSG_SYN)
298 		;
299 	if (flags & LINUX_MSG_CONFIRM)
300 		;
301 	if (flags & LINUX_MSG_RST)
302 		;
303 	if (flags & LINUX_MSG_ERRQUEUE)
304 		;
305 #endif
306 	return (ret_flags);
307 }
308 
309 static int
310 linux_to_bsd_cmsg_type(int cmsg_type)
311 {
312 
313 	switch (cmsg_type) {
314 	case LINUX_SCM_RIGHTS:
315 		return (SCM_RIGHTS);
316 	case LINUX_SCM_CREDENTIALS:
317 		return (SCM_CREDS);
318 	}
319 	return (-1);
320 }
321 
322 static int
323 bsd_to_linux_cmsg_type(int cmsg_type)
324 {
325 
326 	switch (cmsg_type) {
327 	case SCM_RIGHTS:
328 		return (LINUX_SCM_RIGHTS);
329 	case SCM_CREDS:
330 		return (LINUX_SCM_CREDENTIALS);
331 	case SCM_TIMESTAMP:
332 		return (LINUX_SCM_TIMESTAMP);
333 	}
334 	return (-1);
335 }
336 
337 static int
338 linux_to_bsd_msghdr(struct msghdr *bhdr, const struct l_msghdr *lhdr)
339 {
340 	if (lhdr->msg_controllen > INT_MAX)
341 		return (ENOBUFS);
342 
343 	bhdr->msg_name		= PTRIN(lhdr->msg_name);
344 	bhdr->msg_namelen	= lhdr->msg_namelen;
345 	bhdr->msg_iov		= PTRIN(lhdr->msg_iov);
346 	bhdr->msg_iovlen	= lhdr->msg_iovlen;
347 	bhdr->msg_control	= PTRIN(lhdr->msg_control);
348 
349 	/*
350 	 * msg_controllen is skipped since BSD and LINUX control messages
351 	 * are potentially different sizes (e.g. the cred structure used
352 	 * by SCM_CREDS is different between the two operating system).
353 	 *
354 	 * The caller can set it (if necessary) after converting all the
355 	 * control messages.
356 	 */
357 
358 	bhdr->msg_flags		= linux_to_bsd_msg_flags(lhdr->msg_flags);
359 	return (0);
360 }
361 
362 static int
363 bsd_to_linux_msghdr(const struct msghdr *bhdr, struct l_msghdr *lhdr)
364 {
365 	lhdr->msg_name		= PTROUT(bhdr->msg_name);
366 	lhdr->msg_namelen	= bhdr->msg_namelen;
367 	lhdr->msg_iov		= PTROUT(bhdr->msg_iov);
368 	lhdr->msg_iovlen	= bhdr->msg_iovlen;
369 	lhdr->msg_control	= PTROUT(bhdr->msg_control);
370 
371 	/*
372 	 * msg_controllen is skipped since BSD and LINUX control messages
373 	 * are potentially different sizes (e.g. the cred structure used
374 	 * by SCM_CREDS is different between the two operating system).
375 	 *
376 	 * The caller can set it (if necessary) after converting all the
377 	 * control messages.
378 	 */
379 
380 	/* msg_flags skipped */
381 	return (0);
382 }
383 
384 static int
385 linux_set_socket_flags(int lflags, int *flags)
386 {
387 
388 	if (lflags & ~(LINUX_SOCK_CLOEXEC | LINUX_SOCK_NONBLOCK))
389 		return (EINVAL);
390 	if (lflags & LINUX_SOCK_NONBLOCK)
391 		*flags |= SOCK_NONBLOCK;
392 	if (lflags & LINUX_SOCK_CLOEXEC)
393 		*flags |= SOCK_CLOEXEC;
394 	return (0);
395 }
396 
397 static int
398 linux_sendit(struct thread *td, int s, struct msghdr *mp, int flags,
399     struct mbuf *control, enum uio_seg segflg)
400 {
401 	struct sockaddr *to;
402 	int error, len;
403 
404 	if (mp->msg_name != NULL) {
405 		len = mp->msg_namelen;
406 		error = linux_to_bsd_sockaddr(mp->msg_name, &to, &len);
407 		if (error != 0)
408 			return (error);
409 		mp->msg_name = to;
410 	} else
411 		to = NULL;
412 
413 	error = kern_sendit(td, s, mp, linux_to_bsd_msg_flags(flags), control,
414 	    segflg);
415 
416 	if (to)
417 		free(to, M_SONAME);
418 	return (error);
419 }
420 
421 /* Return 0 if IP_HDRINCL is set for the given socket. */
422 static int
423 linux_check_hdrincl(struct thread *td, int s)
424 {
425 	int error, optval;
426 	socklen_t size_val;
427 
428 	size_val = sizeof(optval);
429 	error = kern_getsockopt(td, s, IPPROTO_IP, IP_HDRINCL,
430 	    &optval, UIO_SYSSPACE, &size_val);
431 	if (error != 0)
432 		return (error);
433 
434 	return (optval == 0);
435 }
436 
437 /*
438  * Updated sendto() when IP_HDRINCL is set:
439  * tweak endian-dependent fields in the IP packet.
440  */
441 static int
442 linux_sendto_hdrincl(struct thread *td, struct linux_sendto_args *linux_args)
443 {
444 /*
445  * linux_ip_copysize defines how many bytes we should copy
446  * from the beginning of the IP packet before we customize it for BSD.
447  * It should include all the fields we modify (ip_len and ip_off).
448  */
449 #define linux_ip_copysize	8
450 
451 	struct ip *packet;
452 	struct msghdr msg;
453 	struct iovec aiov[1];
454 	int error;
455 
456 	/* Check that the packet isn't too big or too small. */
457 	if (linux_args->len < linux_ip_copysize ||
458 	    linux_args->len > IP_MAXPACKET)
459 		return (EINVAL);
460 
461 	packet = (struct ip *)malloc(linux_args->len, M_LINUX, M_WAITOK);
462 
463 	/* Make kernel copy of the packet to be sent */
464 	if ((error = copyin(PTRIN(linux_args->msg), packet,
465 	    linux_args->len)))
466 		goto goout;
467 
468 	/* Convert fields from Linux to BSD raw IP socket format */
469 	packet->ip_len = linux_args->len;
470 	packet->ip_off = ntohs(packet->ip_off);
471 
472 	/* Prepare the msghdr and iovec structures describing the new packet */
473 	msg.msg_name = PTRIN(linux_args->to);
474 	msg.msg_namelen = linux_args->tolen;
475 	msg.msg_iov = aiov;
476 	msg.msg_iovlen = 1;
477 	msg.msg_control = NULL;
478 	msg.msg_flags = 0;
479 	aiov[0].iov_base = (char *)packet;
480 	aiov[0].iov_len = linux_args->len;
481 	error = linux_sendit(td, linux_args->s, &msg, linux_args->flags,
482 	    NULL, UIO_SYSSPACE);
483 goout:
484 	free(packet, M_LINUX);
485 	return (error);
486 }
487 
488 int
489 linux_socket(struct thread *td, struct linux_socket_args *args)
490 {
491 	int domain, retval_socket, type;
492 
493 	type = args->type & LINUX_SOCK_TYPE_MASK;
494 	if (type < 0 || type > LINUX_SOCK_MAX)
495 		return (EINVAL);
496 	retval_socket = linux_set_socket_flags(args->type & ~LINUX_SOCK_TYPE_MASK,
497 		&type);
498 	if (retval_socket != 0)
499 		return (retval_socket);
500 	domain = linux_to_bsd_domain(args->domain);
501 	if (domain == -1)
502 		return (EAFNOSUPPORT);
503 
504 	retval_socket = kern_socket(td, domain, type, args->protocol);
505 	if (retval_socket)
506 		return (retval_socket);
507 
508 	if (type == SOCK_RAW
509 	    && (args->protocol == IPPROTO_RAW || args->protocol == 0)
510 	    && domain == PF_INET) {
511 		/* It's a raw IP socket: set the IP_HDRINCL option. */
512 		int hdrincl;
513 
514 		hdrincl = 1;
515 		/* We ignore any error returned by kern_setsockopt() */
516 		kern_setsockopt(td, td->td_retval[0], IPPROTO_IP, IP_HDRINCL,
517 		    &hdrincl, UIO_SYSSPACE, sizeof(hdrincl));
518 	}
519 #ifdef INET6
520 	/*
521 	 * Linux AF_INET6 socket has IPV6_V6ONLY setsockopt set to 0 by default
522 	 * and some apps depend on this. So, set V6ONLY to 0 for Linux apps.
523 	 * For simplicity we do this unconditionally of the net.inet6.ip6.v6only
524 	 * sysctl value.
525 	 */
526 	if (domain == PF_INET6) {
527 		int v6only;
528 
529 		v6only = 0;
530 		/* We ignore any error returned by setsockopt() */
531 		kern_setsockopt(td, td->td_retval[0], IPPROTO_IPV6, IPV6_V6ONLY,
532 		    &v6only, UIO_SYSSPACE, sizeof(v6only));
533 	}
534 #endif
535 
536 	return (retval_socket);
537 }
538 
539 int
540 linux_bind(struct thread *td, struct linux_bind_args *args)
541 {
542 	struct sockaddr *sa;
543 	int error;
544 
545 	error = linux_to_bsd_sockaddr(PTRIN(args->name), &sa,
546 	    &args->namelen);
547 	if (error != 0)
548 		return (error);
549 
550 	error = kern_bindat(td, AT_FDCWD, args->s, sa);
551 	free(sa, M_SONAME);
552 
553 	/* XXX */
554 	if (error == EADDRNOTAVAIL && args->namelen != sizeof(struct sockaddr_in))
555 		return (EINVAL);
556 	return (error);
557 }
558 
559 int
560 linux_connect(struct thread *td, struct linux_connect_args *args)
561 {
562 	struct socket *so;
563 	struct sockaddr *sa;
564 	struct file *fp;
565 	u_int fflag;
566 	int error;
567 
568 	error = linux_to_bsd_sockaddr(PTRIN(args->name), &sa,
569 	    &args->namelen);
570 	if (error != 0)
571 		return (error);
572 
573 	error = kern_connectat(td, AT_FDCWD, args->s, sa);
574 	free(sa, M_SONAME);
575 	if (error != EISCONN)
576 		return (error);
577 
578 	/*
579 	 * Linux doesn't return EISCONN the first time it occurs,
580 	 * when on a non-blocking socket. Instead it returns the
581 	 * error getsockopt(SOL_SOCKET, SO_ERROR) would return on BSD.
582 	 */
583 	error = getsock_cap(td, args->s, &cap_connect_rights,
584 	    &fp, &fflag, NULL);
585 	if (error != 0)
586 		return (error);
587 
588 	error = EISCONN;
589 	so = fp->f_data;
590 	if (fflag & FNONBLOCK) {
591 		SOCK_LOCK(so);
592 		if (so->so_emuldata == 0)
593 			error = so->so_error;
594 		so->so_emuldata = (void *)1;
595 		SOCK_UNLOCK(so);
596 	}
597 	fdrop(fp, td);
598 
599 	return (error);
600 }
601 
602 int
603 linux_listen(struct thread *td, struct linux_listen_args *args)
604 {
605 
606 	return (kern_listen(td, args->s, args->backlog));
607 }
608 
609 static int
610 linux_accept_common(struct thread *td, int s, l_uintptr_t addr,
611     l_uintptr_t namelen, int flags)
612 {
613 	struct l_sockaddr *lsa;
614 	struct sockaddr *sa;
615 	struct file *fp;
616 	int bflags, len;
617 	struct socket *so;
618 	int error, error1;
619 
620 	bflags = 0;
621 	error = linux_set_socket_flags(flags, &bflags);
622 	if (error != 0)
623 		return (error);
624 
625 	sa = NULL;
626 	if (PTRIN(addr) == NULL) {
627 		len = 0;
628 		error = kern_accept4(td, s, NULL, NULL, bflags, NULL);
629 	} else {
630 		error = copyin(PTRIN(namelen), &len, sizeof(len));
631 		if (error != 0)
632 			return (error);
633 		if (len < 0)
634 			return (EINVAL);
635 		error = kern_accept4(td, s, &sa, &len, bflags, &fp);
636 		if (error == 0)
637 			fdrop(fp, td);
638 	}
639 
640 	if (error != 0) {
641 		/*
642 		 * XXX. This is wrong, different sockaddr structures
643 		 * have different sizes.
644 		 */
645 		if (error == EFAULT && namelen != sizeof(struct sockaddr_in))
646 		{
647 			error = EINVAL;
648 			goto out;
649 		}
650 		if (error == EINVAL) {
651 			error1 = getsock_cap(td, s, &cap_accept_rights, &fp, NULL, NULL);
652 			if (error1 != 0) {
653 				error = error1;
654 				goto out;
655 			}
656 			so = fp->f_data;
657 			if (so->so_type == SOCK_DGRAM)
658 				error = EOPNOTSUPP;
659 			fdrop(fp, td);
660 		}
661 		goto out;
662 	}
663 
664 	if (len != 0 && error == 0) {
665 		error = bsd_to_linux_sockaddr(sa, &lsa, len);
666 		if (error == 0)
667 			error = copyout(lsa, PTRIN(addr), len);
668 		free(lsa, M_SONAME);
669 	}
670 
671 	free(sa, M_SONAME);
672 
673 out:
674 	if (error != 0) {
675 		(void)kern_close(td, td->td_retval[0]);
676 		td->td_retval[0] = 0;
677 	}
678 	return (error);
679 }
680 
681 int
682 linux_accept(struct thread *td, struct linux_accept_args *args)
683 {
684 
685 	return (linux_accept_common(td, args->s, args->addr,
686 	    args->namelen, 0));
687 }
688 
689 int
690 linux_accept4(struct thread *td, struct linux_accept4_args *args)
691 {
692 
693 	return (linux_accept_common(td, args->s, args->addr,
694 	    args->namelen, args->flags));
695 }
696 
697 int
698 linux_getsockname(struct thread *td, struct linux_getsockname_args *args)
699 {
700 	struct l_sockaddr *lsa;
701 	struct sockaddr *sa;
702 	int len, error;
703 
704 	error = copyin(PTRIN(args->namelen), &len, sizeof(len));
705 	if (error != 0)
706 		return (error);
707 
708 	error = kern_getsockname(td, args->s, &sa, &len);
709 	if (error != 0)
710 		return (error);
711 
712 	if (len != 0) {
713 		error = bsd_to_linux_sockaddr(sa, &lsa, len);
714 		if (error == 0)
715 			error = copyout(lsa, PTRIN(args->addr),
716 			    len);
717 		free(lsa, M_SONAME);
718 	}
719 
720 	free(sa, M_SONAME);
721 	if (error == 0)
722 		error = copyout(&len, PTRIN(args->namelen), sizeof(len));
723 	return (error);
724 }
725 
726 int
727 linux_getpeername(struct thread *td, struct linux_getpeername_args *args)
728 {
729 	struct l_sockaddr *lsa;
730 	struct sockaddr *sa;
731 	int len, error;
732 
733 	error = copyin(PTRIN(args->namelen), &len, sizeof(len));
734 	if (error != 0)
735 		return (error);
736 	if (len < 0)
737 		return (EINVAL);
738 
739 	error = kern_getpeername(td, args->s, &sa, &len);
740 	if (error != 0)
741 		return (error);
742 
743 	if (len != 0) {
744 		error = bsd_to_linux_sockaddr(sa, &lsa, len);
745 		if (error == 0)
746 			error = copyout(lsa, PTRIN(args->addr),
747 			    len);
748 		free(lsa, M_SONAME);
749 	}
750 
751 	free(sa, M_SONAME);
752 	if (error == 0)
753 		error = copyout(&len, PTRIN(args->namelen), sizeof(len));
754 	return (error);
755 }
756 
757 int
758 linux_socketpair(struct thread *td, struct linux_socketpair_args *args)
759 {
760 	int domain, error, sv[2], type;
761 
762 	domain = linux_to_bsd_domain(args->domain);
763 	if (domain != PF_LOCAL)
764 		return (EAFNOSUPPORT);
765 	type = args->type & LINUX_SOCK_TYPE_MASK;
766 	if (type < 0 || type > LINUX_SOCK_MAX)
767 		return (EINVAL);
768 	error = linux_set_socket_flags(args->type & ~LINUX_SOCK_TYPE_MASK,
769 	    &type);
770 	if (error != 0)
771 		return (error);
772 	if (args->protocol != 0 && args->protocol != PF_UNIX) {
773 
774 		/*
775 		 * Use of PF_UNIX as protocol argument is not right,
776 		 * but Linux does it.
777 		 * Do not map PF_UNIX as its Linux value is identical
778 		 * to FreeBSD one.
779 		 */
780 		return (EPROTONOSUPPORT);
781 	}
782 	error = kern_socketpair(td, domain, type, 0, sv);
783 	if (error != 0)
784                 return (error);
785         error = copyout(sv, PTRIN(args->rsv), 2 * sizeof(int));
786         if (error != 0) {
787                 (void)kern_close(td, sv[0]);
788                 (void)kern_close(td, sv[1]);
789         }
790 	return (error);
791 }
792 
793 #if defined(__i386__) || (defined(__amd64__) && defined(COMPAT_LINUX32))
794 struct linux_send_args {
795 	register_t s;
796 	register_t msg;
797 	register_t len;
798 	register_t flags;
799 };
800 
801 static int
802 linux_send(struct thread *td, struct linux_send_args *args)
803 {
804 	struct sendto_args /* {
805 		int s;
806 		caddr_t buf;
807 		int len;
808 		int flags;
809 		caddr_t to;
810 		int tolen;
811 	} */ bsd_args;
812 	struct file *fp;
813 	int error, fflag;
814 
815 	bsd_args.s = args->s;
816 	bsd_args.buf = (caddr_t)PTRIN(args->msg);
817 	bsd_args.len = args->len;
818 	bsd_args.flags = args->flags;
819 	bsd_args.to = NULL;
820 	bsd_args.tolen = 0;
821 	error = sys_sendto(td, &bsd_args);
822 	if (error == ENOTCONN) {
823 		/*
824 		 * Linux doesn't return ENOTCONN for non-blocking sockets.
825 		 * Instead it returns the EAGAIN.
826 		 */
827 		error = getsock_cap(td, args->s, &cap_send_rights, &fp,
828 		    &fflag, NULL);
829 		if (error == 0) {
830 			if (fflag & FNONBLOCK)
831 				error = EAGAIN;
832 			fdrop(fp, td);
833 		}
834 	}
835 	return (error);
836 }
837 
838 struct linux_recv_args {
839 	register_t s;
840 	register_t msg;
841 	register_t len;
842 	register_t flags;
843 };
844 
845 static int
846 linux_recv(struct thread *td, struct linux_recv_args *args)
847 {
848 	struct recvfrom_args /* {
849 		int s;
850 		caddr_t buf;
851 		int len;
852 		int flags;
853 		struct sockaddr *from;
854 		socklen_t fromlenaddr;
855 	} */ bsd_args;
856 
857 	bsd_args.s = args->s;
858 	bsd_args.buf = (caddr_t)PTRIN(args->msg);
859 	bsd_args.len = args->len;
860 	bsd_args.flags = linux_to_bsd_msg_flags(args->flags);
861 	bsd_args.from = NULL;
862 	bsd_args.fromlenaddr = 0;
863 	return (sys_recvfrom(td, &bsd_args));
864 }
865 #endif /* __i386__ || (__amd64__ && COMPAT_LINUX32) */
866 
867 int
868 linux_sendto(struct thread *td, struct linux_sendto_args *args)
869 {
870 	struct msghdr msg;
871 	struct iovec aiov;
872 
873 	if (linux_check_hdrincl(td, args->s) == 0)
874 		/* IP_HDRINCL set, tweak the packet before sending */
875 		return (linux_sendto_hdrincl(td, args));
876 
877 	msg.msg_name = PTRIN(args->to);
878 	msg.msg_namelen = args->tolen;
879 	msg.msg_iov = &aiov;
880 	msg.msg_iovlen = 1;
881 	msg.msg_control = NULL;
882 	msg.msg_flags = 0;
883 	aiov.iov_base = PTRIN(args->msg);
884 	aiov.iov_len = args->len;
885 	return (linux_sendit(td, args->s, &msg, args->flags, NULL,
886 	    UIO_USERSPACE));
887 }
888 
889 int
890 linux_recvfrom(struct thread *td, struct linux_recvfrom_args *args)
891 {
892 	struct l_sockaddr *lsa;
893 	struct sockaddr *sa;
894 	struct msghdr msg;
895 	struct iovec aiov;
896 	int error, fromlen;
897 
898 	if (PTRIN(args->fromlen) != NULL) {
899 		error = copyin(PTRIN(args->fromlen), &fromlen,
900 		    sizeof(fromlen));
901 		if (error != 0)
902 			return (error);
903 		if (fromlen < 0)
904 			return (EINVAL);
905 		sa = malloc(fromlen, M_SONAME, M_WAITOK);
906 	} else {
907 		fromlen = 0;
908 		sa = NULL;
909 	}
910 
911 	msg.msg_name = sa;
912 	msg.msg_namelen = fromlen;
913 	msg.msg_iov = &aiov;
914 	msg.msg_iovlen = 1;
915 	aiov.iov_base = PTRIN(args->buf);
916 	aiov.iov_len = args->len;
917 	msg.msg_control = 0;
918 	msg.msg_flags = linux_to_bsd_msg_flags(args->flags);
919 
920 	error = kern_recvit(td, args->s, &msg, UIO_SYSSPACE, NULL);
921 	if (error != 0)
922 		goto out;
923 
924 	if (PTRIN(args->from) != NULL) {
925 		error = bsd_to_linux_sockaddr(sa, &lsa, msg.msg_namelen);
926 		if (error == 0)
927 			error = copyout(lsa, PTRIN(args->from),
928 			    msg.msg_namelen);
929 		free(lsa, M_SONAME);
930 	}
931 
932 	if (error == 0 && PTRIN(args->fromlen) != NULL)
933 		error = copyout(&msg.msg_namelen, PTRIN(args->fromlen),
934 		    sizeof(msg.msg_namelen));
935 out:
936 	free(sa, M_SONAME);
937 	return (error);
938 }
939 
940 static int
941 linux_sendmsg_common(struct thread *td, l_int s, struct l_msghdr *msghdr,
942     l_uint flags)
943 {
944 	struct cmsghdr *cmsg;
945 	struct mbuf *control;
946 	struct msghdr msg;
947 	struct l_cmsghdr linux_cmsg;
948 	struct l_cmsghdr *ptr_cmsg;
949 	struct l_msghdr linux_msg;
950 	struct iovec *iov;
951 	socklen_t datalen;
952 	struct sockaddr *sa;
953 	struct socket *so;
954 	sa_family_t sa_family;
955 	struct file *fp;
956 	void *data;
957 	l_size_t len;
958 	l_size_t clen;
959 	int error, fflag;
960 
961 	error = copyin(msghdr, &linux_msg, sizeof(linux_msg));
962 	if (error != 0)
963 		return (error);
964 
965 	/*
966 	 * Some Linux applications (ping) define a non-NULL control data
967 	 * pointer, but a msg_controllen of 0, which is not allowed in the
968 	 * FreeBSD system call interface.  NULL the msg_control pointer in
969 	 * order to handle this case.  This should be checked, but allows the
970 	 * Linux ping to work.
971 	 */
972 	if (PTRIN(linux_msg.msg_control) != NULL && linux_msg.msg_controllen == 0)
973 		linux_msg.msg_control = PTROUT(NULL);
974 
975 	error = linux_to_bsd_msghdr(&msg, &linux_msg);
976 	if (error != 0)
977 		return (error);
978 
979 #ifdef COMPAT_LINUX32
980 	error = linux32_copyiniov(PTRIN(msg.msg_iov), msg.msg_iovlen,
981 	    &iov, EMSGSIZE);
982 #else
983 	error = copyiniov(msg.msg_iov, msg.msg_iovlen, &iov, EMSGSIZE);
984 #endif
985 	if (error != 0)
986 		return (error);
987 
988 	control = NULL;
989 
990 	error = kern_getsockname(td, s, &sa, &datalen);
991 	if (error != 0)
992 		goto bad;
993 	sa_family = sa->sa_family;
994 	free(sa, M_SONAME);
995 
996 	if (flags & LINUX_MSG_OOB) {
997 		error = EOPNOTSUPP;
998 		if (sa_family == AF_UNIX)
999 			goto bad;
1000 
1001 		error = getsock_cap(td, s, &cap_send_rights, &fp,
1002 		    &fflag, NULL);
1003 		if (error != 0)
1004 			goto bad;
1005 		so = fp->f_data;
1006 		if (so->so_type != SOCK_STREAM)
1007 			error = EOPNOTSUPP;
1008 		fdrop(fp, td);
1009 		if (error != 0)
1010 			goto bad;
1011 	}
1012 
1013 	if (linux_msg.msg_controllen >= sizeof(struct l_cmsghdr)) {
1014 
1015 		error = ENOBUFS;
1016 		control = m_get(M_WAITOK, MT_CONTROL);
1017 		MCLGET(control, M_WAITOK);
1018 		data = mtod(control, void *);
1019 		datalen = 0;
1020 
1021 		ptr_cmsg = PTRIN(linux_msg.msg_control);
1022 		clen = linux_msg.msg_controllen;
1023 		do {
1024 			error = copyin(ptr_cmsg, &linux_cmsg,
1025 			    sizeof(struct l_cmsghdr));
1026 			if (error != 0)
1027 				goto bad;
1028 
1029 			error = EINVAL;
1030 			if (linux_cmsg.cmsg_len < sizeof(struct l_cmsghdr) ||
1031 			    linux_cmsg.cmsg_len > clen)
1032 				goto bad;
1033 
1034 			if (datalen + CMSG_HDRSZ > MCLBYTES)
1035 				goto bad;
1036 
1037 			/*
1038 			 * Now we support only SCM_RIGHTS and SCM_CRED,
1039 			 * so return EINVAL in any other cmsg_type
1040 			 */
1041 			cmsg = data;
1042 			cmsg->cmsg_type =
1043 			    linux_to_bsd_cmsg_type(linux_cmsg.cmsg_type);
1044 			cmsg->cmsg_level =
1045 			    linux_to_bsd_sockopt_level(linux_cmsg.cmsg_level);
1046 			if (cmsg->cmsg_type == -1
1047 			    || cmsg->cmsg_level != SOL_SOCKET)
1048 				goto bad;
1049 
1050 			/*
1051 			 * Some applications (e.g. pulseaudio) attempt to
1052 			 * send ancillary data even if the underlying protocol
1053 			 * doesn't support it which is not allowed in the
1054 			 * FreeBSD system call interface.
1055 			 */
1056 			if (sa_family != AF_UNIX)
1057 				continue;
1058 
1059 			if (cmsg->cmsg_type == SCM_CREDS) {
1060 				len = sizeof(struct cmsgcred);
1061 				if (datalen + CMSG_SPACE(len) > MCLBYTES)
1062 					goto bad;
1063 
1064 				/*
1065 				 * The lower levels will fill in the structure
1066 				 */
1067 				memset(CMSG_DATA(data), 0, len);
1068 			} else {
1069 				len = linux_cmsg.cmsg_len - L_CMSG_HDRSZ;
1070 				if (datalen + CMSG_SPACE(len) < datalen ||
1071 				    datalen + CMSG_SPACE(len) > MCLBYTES)
1072 					goto bad;
1073 
1074 				error = copyin(LINUX_CMSG_DATA(ptr_cmsg),
1075 				    CMSG_DATA(data), len);
1076 				if (error != 0)
1077 					goto bad;
1078 			}
1079 
1080 			cmsg->cmsg_len = CMSG_LEN(len);
1081 			data = (char *)data + CMSG_SPACE(len);
1082 			datalen += CMSG_SPACE(len);
1083 
1084 			if (clen <= LINUX_CMSG_ALIGN(linux_cmsg.cmsg_len))
1085 				break;
1086 
1087 			clen -= LINUX_CMSG_ALIGN(linux_cmsg.cmsg_len);
1088 			ptr_cmsg = (struct l_cmsghdr *)((char *)ptr_cmsg +
1089 			    LINUX_CMSG_ALIGN(linux_cmsg.cmsg_len));
1090 		} while(clen >= sizeof(struct l_cmsghdr));
1091 
1092 		control->m_len = datalen;
1093 		if (datalen == 0) {
1094 			m_freem(control);
1095 			control = NULL;
1096 		}
1097 	}
1098 
1099 	msg.msg_iov = iov;
1100 	msg.msg_flags = 0;
1101 	error = linux_sendit(td, s, &msg, flags, control, UIO_USERSPACE);
1102 	control = NULL;
1103 
1104 bad:
1105 	m_freem(control);
1106 	free(iov, M_IOV);
1107 	return (error);
1108 }
1109 
1110 int
1111 linux_sendmsg(struct thread *td, struct linux_sendmsg_args *args)
1112 {
1113 
1114 	return (linux_sendmsg_common(td, args->s, PTRIN(args->msg),
1115 	    args->flags));
1116 }
1117 
1118 int
1119 linux_sendmmsg(struct thread *td, struct linux_sendmmsg_args *args)
1120 {
1121 	struct l_mmsghdr *msg;
1122 	l_uint retval;
1123 	int error, datagrams;
1124 
1125 	if (args->vlen > UIO_MAXIOV)
1126 		args->vlen = UIO_MAXIOV;
1127 
1128 	msg = PTRIN(args->msg);
1129 	datagrams = 0;
1130 	while (datagrams < args->vlen) {
1131 		error = linux_sendmsg_common(td, args->s, &msg->msg_hdr,
1132 		    args->flags);
1133 		if (error != 0)
1134 			break;
1135 
1136 		retval = td->td_retval[0];
1137 		error = copyout(&retval, &msg->msg_len, sizeof(msg->msg_len));
1138 		if (error != 0)
1139 			break;
1140 		++msg;
1141 		++datagrams;
1142 	}
1143 	if (error == 0)
1144 		td->td_retval[0] = datagrams;
1145 	return (error);
1146 }
1147 
1148 static int
1149 linux_recvmsg_common(struct thread *td, l_int s, struct l_msghdr *msghdr,
1150     l_uint flags, struct msghdr *msg)
1151 {
1152 	struct cmsghdr *cm;
1153 	struct cmsgcred *cmcred;
1154 	struct l_cmsghdr *linux_cmsg = NULL;
1155 	struct l_ucred linux_ucred;
1156 	socklen_t datalen, maxlen, outlen;
1157 	struct l_msghdr linux_msg;
1158 	struct iovec *iov, *uiov;
1159 	struct mbuf *control = NULL;
1160 	struct mbuf **controlp;
1161 	struct timeval *ftmvl;
1162 	struct l_sockaddr *lsa;
1163 	struct sockaddr *sa;
1164 	l_timeval ltmvl;
1165 	caddr_t outbuf;
1166 	void *data;
1167 	int error, i, fd, fds, *fdp;
1168 
1169 	error = copyin(msghdr, &linux_msg, sizeof(linux_msg));
1170 	if (error != 0)
1171 		return (error);
1172 
1173 	error = linux_to_bsd_msghdr(msg, &linux_msg);
1174 	if (error != 0)
1175 		return (error);
1176 
1177 #ifdef COMPAT_LINUX32
1178 	error = linux32_copyiniov(PTRIN(msg->msg_iov), msg->msg_iovlen,
1179 	    &iov, EMSGSIZE);
1180 #else
1181 	error = copyiniov(msg->msg_iov, msg->msg_iovlen, &iov, EMSGSIZE);
1182 #endif
1183 	if (error != 0)
1184 		return (error);
1185 
1186 	if (msg->msg_name) {
1187 		sa = malloc(msg->msg_namelen, M_SONAME, M_WAITOK);
1188 		msg->msg_name = sa;
1189 	} else
1190 		sa = NULL;
1191 
1192 	uiov = msg->msg_iov;
1193 	msg->msg_iov = iov;
1194 	controlp = (msg->msg_control != NULL) ? &control : NULL;
1195 	error = kern_recvit(td, s, msg, UIO_SYSSPACE, controlp);
1196 	msg->msg_iov = uiov;
1197 	if (error != 0)
1198 		goto bad;
1199 
1200 	if (msg->msg_name) {
1201 		msg->msg_name = PTRIN(linux_msg.msg_name);
1202 		error = bsd_to_linux_sockaddr(sa, &lsa, msg->msg_namelen);
1203 		if (error == 0)
1204 			error = copyout(lsa, PTRIN(msg->msg_name),
1205 			    msg->msg_namelen);
1206 		free(lsa, M_SONAME);
1207 		if (error != 0)
1208 			goto bad;
1209 	}
1210 
1211 	error = bsd_to_linux_msghdr(msg, &linux_msg);
1212 	if (error != 0)
1213 		goto bad;
1214 
1215 	maxlen = linux_msg.msg_controllen;
1216 	linux_msg.msg_controllen = 0;
1217 	if (control) {
1218 		linux_cmsg = malloc(L_CMSG_HDRSZ, M_LINUX, M_WAITOK | M_ZERO);
1219 
1220 		msg->msg_control = mtod(control, struct cmsghdr *);
1221 		msg->msg_controllen = control->m_len;
1222 
1223 		cm = CMSG_FIRSTHDR(msg);
1224 		outbuf = PTRIN(linux_msg.msg_control);
1225 		outlen = 0;
1226 		while (cm != NULL) {
1227 			linux_cmsg->cmsg_type =
1228 			    bsd_to_linux_cmsg_type(cm->cmsg_type);
1229 			linux_cmsg->cmsg_level =
1230 			    bsd_to_linux_sockopt_level(cm->cmsg_level);
1231 			if (linux_cmsg->cmsg_type == -1 ||
1232 			    cm->cmsg_level != SOL_SOCKET) {
1233 				error = EINVAL;
1234 				goto bad;
1235 			}
1236 
1237 			data = CMSG_DATA(cm);
1238 			datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1239 
1240 			switch (cm->cmsg_type) {
1241 			case SCM_RIGHTS:
1242 				if (flags & LINUX_MSG_CMSG_CLOEXEC) {
1243 					fds = datalen / sizeof(int);
1244 					fdp = data;
1245 					for (i = 0; i < fds; i++) {
1246 						fd = *fdp++;
1247 						(void)kern_fcntl(td, fd,
1248 						    F_SETFD, FD_CLOEXEC);
1249 					}
1250 				}
1251 				break;
1252 
1253 			case SCM_CREDS:
1254 				/*
1255 				 * Currently LOCAL_CREDS is never in
1256 				 * effect for Linux so no need to worry
1257 				 * about sockcred
1258 				 */
1259 				if (datalen != sizeof(*cmcred)) {
1260 					error = EMSGSIZE;
1261 					goto bad;
1262 				}
1263 				cmcred = (struct cmsgcred *)data;
1264 				bzero(&linux_ucred, sizeof(linux_ucred));
1265 				linux_ucred.pid = cmcred->cmcred_pid;
1266 				linux_ucred.uid = cmcred->cmcred_uid;
1267 				linux_ucred.gid = cmcred->cmcred_gid;
1268 				data = &linux_ucred;
1269 				datalen = sizeof(linux_ucred);
1270 				break;
1271 
1272 			case SCM_TIMESTAMP:
1273 				if (datalen != sizeof(struct timeval)) {
1274 					error = EMSGSIZE;
1275 					goto bad;
1276 				}
1277 				ftmvl = (struct timeval *)data;
1278 				ltmvl.tv_sec = ftmvl->tv_sec;
1279 				ltmvl.tv_usec = ftmvl->tv_usec;
1280 				data = &ltmvl;
1281 				datalen = sizeof(ltmvl);
1282 				break;
1283 			}
1284 
1285 			if (outlen + LINUX_CMSG_LEN(datalen) > maxlen) {
1286 				if (outlen == 0) {
1287 					error = EMSGSIZE;
1288 					goto bad;
1289 				} else {
1290 					linux_msg.msg_flags |= LINUX_MSG_CTRUNC;
1291 					m_dispose_extcontrolm(control);
1292 					goto out;
1293 				}
1294 			}
1295 
1296 			linux_cmsg->cmsg_len = LINUX_CMSG_LEN(datalen);
1297 
1298 			error = copyout(linux_cmsg, outbuf, L_CMSG_HDRSZ);
1299 			if (error != 0)
1300 				goto bad;
1301 			outbuf += L_CMSG_HDRSZ;
1302 
1303 			error = copyout(data, outbuf, datalen);
1304 			if (error != 0)
1305 				goto bad;
1306 
1307 			outbuf += LINUX_CMSG_ALIGN(datalen);
1308 			outlen += LINUX_CMSG_LEN(datalen);
1309 
1310 			cm = CMSG_NXTHDR(msg, cm);
1311 		}
1312 		linux_msg.msg_controllen = outlen;
1313 	}
1314 
1315 out:
1316 	error = copyout(&linux_msg, msghdr, sizeof(linux_msg));
1317 
1318 bad:
1319 	if (control != NULL) {
1320 		if (error != 0)
1321 			m_dispose_extcontrolm(control);
1322 		m_freem(control);
1323 	}
1324 	free(iov, M_IOV);
1325 	free(linux_cmsg, M_LINUX);
1326 	free(sa, M_SONAME);
1327 
1328 	return (error);
1329 }
1330 
1331 int
1332 linux_recvmsg(struct thread *td, struct linux_recvmsg_args *args)
1333 {
1334 	struct msghdr bsd_msg;
1335 
1336 	return (linux_recvmsg_common(td, args->s, PTRIN(args->msg),
1337 	    args->flags, &bsd_msg));
1338 }
1339 
1340 int
1341 linux_recvmmsg(struct thread *td, struct linux_recvmmsg_args *args)
1342 {
1343 	struct l_mmsghdr *msg;
1344 	struct msghdr bsd_msg;
1345 	struct l_timespec lts;
1346 	struct timespec ts, tts;
1347 	l_uint retval;
1348 	int error, datagrams;
1349 
1350 	if (args->timeout) {
1351 		error = copyin(args->timeout, &lts, sizeof(struct l_timespec));
1352 		if (error != 0)
1353 			return (error);
1354 		error = linux_to_native_timespec(&ts, &lts);
1355 		if (error != 0)
1356 			return (error);
1357 		getnanotime(&tts);
1358 		timespecadd(&tts, &ts, &tts);
1359 	}
1360 
1361 	msg = PTRIN(args->msg);
1362 	datagrams = 0;
1363 	while (datagrams < args->vlen) {
1364 		error = linux_recvmsg_common(td, args->s, &msg->msg_hdr,
1365 		    args->flags & ~LINUX_MSG_WAITFORONE, &bsd_msg);
1366 		if (error != 0)
1367 			break;
1368 
1369 		retval = td->td_retval[0];
1370 		error = copyout(&retval, &msg->msg_len, sizeof(msg->msg_len));
1371 		if (error != 0)
1372 			break;
1373 		++msg;
1374 		++datagrams;
1375 
1376 		/*
1377 		 * MSG_WAITFORONE turns on MSG_DONTWAIT after one packet.
1378 		 */
1379 		if (args->flags & LINUX_MSG_WAITFORONE)
1380 			args->flags |= LINUX_MSG_DONTWAIT;
1381 
1382 		/*
1383 		 * See BUGS section of recvmmsg(2).
1384 		 */
1385 		if (args->timeout) {
1386 			getnanotime(&ts);
1387 			timespecsub(&ts, &tts, &ts);
1388 			if (!timespecisset(&ts) || ts.tv_sec > 0)
1389 				break;
1390 		}
1391 		/* Out of band data, return right away. */
1392 		if (bsd_msg.msg_flags & MSG_OOB)
1393 			break;
1394 	}
1395 	if (error == 0)
1396 		td->td_retval[0] = datagrams;
1397 	return (error);
1398 }
1399 
1400 int
1401 linux_shutdown(struct thread *td, struct linux_shutdown_args *args)
1402 {
1403 
1404 	return (kern_shutdown(td, args->s, args->how));
1405 }
1406 
1407 int
1408 linux_setsockopt(struct thread *td, struct linux_setsockopt_args *args)
1409 {
1410 	l_timeval linux_tv;
1411 	struct sockaddr *sa;
1412 	struct timeval tv;
1413 	socklen_t len;
1414 	int error, level, name;
1415 
1416 	level = linux_to_bsd_sockopt_level(args->level);
1417 	switch (level) {
1418 	case SOL_SOCKET:
1419 		name = linux_to_bsd_so_sockopt(args->optname);
1420 		switch (name) {
1421 		case SO_RCVTIMEO:
1422 			/* FALLTHROUGH */
1423 		case SO_SNDTIMEO:
1424 			error = copyin(PTRIN(args->optval), &linux_tv,
1425 			    sizeof(linux_tv));
1426 			if (error != 0)
1427 				return (error);
1428 			tv.tv_sec = linux_tv.tv_sec;
1429 			tv.tv_usec = linux_tv.tv_usec;
1430 			return (kern_setsockopt(td, args->s, level,
1431 			    name, &tv, UIO_SYSSPACE, sizeof(tv)));
1432 			/* NOTREACHED */
1433 		default:
1434 			break;
1435 		}
1436 		break;
1437 	case IPPROTO_IP:
1438 		if (args->optname == LINUX_IP_RECVERR &&
1439 		    linux_ignore_ip_recverr) {
1440 			/*
1441 			 * XXX: This is a hack to unbreak DNS resolution
1442 			 *	with glibc 2.30 and above.
1443 			 */
1444 			return (0);
1445 		}
1446 		name = linux_to_bsd_ip_sockopt(args->optname);
1447 		break;
1448 	case IPPROTO_IPV6:
1449 		name = linux_to_bsd_ip6_sockopt(args->optname);
1450 		break;
1451 	case IPPROTO_TCP:
1452 		name = linux_to_bsd_tcp_sockopt(args->optname);
1453 		break;
1454 	default:
1455 		name = -1;
1456 		break;
1457 	}
1458 	if (name == -1) {
1459 		linux_msg(curthread,
1460 		    "unsupported setsockopt level %d optname %d",
1461 		    args->level, args->optname);
1462 		return (ENOPROTOOPT);
1463 	}
1464 
1465 	if (name == IPV6_NEXTHOP) {
1466 		len = args->optlen;
1467 		error = linux_to_bsd_sockaddr(PTRIN(args->optval), &sa, &len);
1468 		if (error != 0)
1469 			return (error);
1470 
1471 		error = kern_setsockopt(td, args->s, level,
1472 		    name, sa, UIO_SYSSPACE, len);
1473 		free(sa, M_SONAME);
1474 	} else {
1475 		error = kern_setsockopt(td, args->s, level,
1476 		    name, PTRIN(args->optval), UIO_USERSPACE, args->optlen);
1477 	}
1478 
1479 	return (error);
1480 }
1481 
1482 int
1483 linux_getsockopt(struct thread *td, struct linux_getsockopt_args *args)
1484 {
1485 	l_timeval linux_tv;
1486 	struct timeval tv;
1487 	socklen_t tv_len, xulen, len;
1488 	struct l_sockaddr *lsa;
1489 	struct sockaddr *sa;
1490 	struct xucred xu;
1491 	struct l_ucred lxu;
1492 	int error, level, name, newval;
1493 
1494 	level = linux_to_bsd_sockopt_level(args->level);
1495 	switch (level) {
1496 	case SOL_SOCKET:
1497 		name = linux_to_bsd_so_sockopt(args->optname);
1498 		switch (name) {
1499 		case SO_RCVTIMEO:
1500 			/* FALLTHROUGH */
1501 		case SO_SNDTIMEO:
1502 			tv_len = sizeof(tv);
1503 			error = kern_getsockopt(td, args->s, level,
1504 			    name, &tv, UIO_SYSSPACE, &tv_len);
1505 			if (error != 0)
1506 				return (error);
1507 			linux_tv.tv_sec = tv.tv_sec;
1508 			linux_tv.tv_usec = tv.tv_usec;
1509 			return (copyout(&linux_tv, PTRIN(args->optval),
1510 			    sizeof(linux_tv)));
1511 			/* NOTREACHED */
1512 		case LOCAL_PEERCRED:
1513 			if (args->optlen < sizeof(lxu))
1514 				return (EINVAL);
1515 			/*
1516 			 * LOCAL_PEERCRED is not served at the SOL_SOCKET level,
1517 			 * but by the Unix socket's level 0.
1518 			 */
1519 			level = 0;
1520 			xulen = sizeof(xu);
1521 			error = kern_getsockopt(td, args->s, level,
1522 			    name, &xu, UIO_SYSSPACE, &xulen);
1523 			if (error != 0)
1524 				return (error);
1525 			lxu.pid = xu.cr_pid;
1526 			lxu.uid = xu.cr_uid;
1527 			lxu.gid = xu.cr_gid;
1528 			return (copyout(&lxu, PTRIN(args->optval), sizeof(lxu)));
1529 			/* NOTREACHED */
1530 		case SO_ERROR:
1531 			len = sizeof(newval);
1532 			error = kern_getsockopt(td, args->s, level,
1533 			    name, &newval, UIO_SYSSPACE, &len);
1534 			if (error != 0)
1535 				return (error);
1536 			newval = -SV_ABI_ERRNO(td->td_proc, newval);
1537 			return (copyout(&newval, PTRIN(args->optval), len));
1538 			/* NOTREACHED */
1539 		default:
1540 			break;
1541 		}
1542 		break;
1543 	case IPPROTO_IP:
1544 		name = linux_to_bsd_ip_sockopt(args->optname);
1545 		break;
1546 	case IPPROTO_IPV6:
1547 		name = linux_to_bsd_ip6_sockopt(args->optname);
1548 		break;
1549 	case IPPROTO_TCP:
1550 		name = linux_to_bsd_tcp_sockopt(args->optname);
1551 		break;
1552 	default:
1553 		name = -1;
1554 		break;
1555 	}
1556 	if (name == -1) {
1557 		linux_msg(curthread,
1558 		    "unsupported getsockopt level %d optname %d",
1559 		    args->level, args->optname);
1560 		return (EINVAL);
1561 	}
1562 
1563 	if (name == IPV6_NEXTHOP) {
1564 		error = copyin(PTRIN(args->optlen), &len, sizeof(len));
1565                 if (error != 0)
1566                         return (error);
1567 		sa = malloc(len, M_SONAME, M_WAITOK);
1568 
1569 		error = kern_getsockopt(td, args->s, level,
1570 		    name, sa, UIO_SYSSPACE, &len);
1571 		if (error != 0)
1572 			goto out;
1573 
1574 		error = bsd_to_linux_sockaddr(sa, &lsa, len);
1575 		if (error == 0)
1576 			error = copyout(lsa, PTRIN(args->optval), len);
1577 		free(lsa, M_SONAME);
1578 		if (error == 0)
1579 			error = copyout(&len, PTRIN(args->optlen),
1580 			    sizeof(len));
1581 out:
1582 		free(sa, M_SONAME);
1583 	} else {
1584 		if (args->optval) {
1585 			error = copyin(PTRIN(args->optlen), &len, sizeof(len));
1586 			if (error != 0)
1587 				return (error);
1588 		}
1589 		error = kern_getsockopt(td, args->s, level,
1590 		    name, PTRIN(args->optval), UIO_USERSPACE, &len);
1591 		if (error == 0)
1592 			error = copyout(&len, PTRIN(args->optlen),
1593 			    sizeof(len));
1594 	}
1595 
1596 	return (error);
1597 }
1598 
1599 static int
1600 linux_sendfile_common(struct thread *td, l_int out, l_int in,
1601     l_loff_t *offset, l_size_t count)
1602 {
1603 	off_t bytes_read;
1604 	int error;
1605 	l_loff_t current_offset;
1606 	struct file *fp;
1607 
1608 	AUDIT_ARG_FD(in);
1609 	error = fget_read(td, in, &cap_pread_rights, &fp);
1610 	if (error != 0)
1611 		return (error);
1612 
1613 	if (offset != NULL) {
1614 		current_offset = *offset;
1615 	} else {
1616 		error = (fp->f_ops->fo_flags & DFLAG_SEEKABLE) != 0 ?
1617 		    fo_seek(fp, 0, SEEK_CUR, td) : ESPIPE;
1618 		if (error != 0)
1619 			goto drop;
1620 		current_offset = td->td_uretoff.tdu_off;
1621 	}
1622 
1623 	bytes_read = 0;
1624 
1625 	/* Linux cannot have 0 count. */
1626 	if (count <= 0 || current_offset < 0) {
1627 		error = EINVAL;
1628 		goto drop;
1629 	}
1630 
1631 	error = fo_sendfile(fp, out, NULL, NULL, current_offset, count,
1632 	    &bytes_read, 0, td);
1633 	if (error != 0)
1634 		goto drop;
1635 	current_offset += bytes_read;
1636 
1637 	if (offset != NULL) {
1638 		*offset = current_offset;
1639 	} else {
1640 		error = fo_seek(fp, current_offset, SEEK_SET, td);
1641 		if (error != 0)
1642 			goto drop;
1643 	}
1644 
1645 	td->td_retval[0] = (ssize_t)bytes_read;
1646 drop:
1647 	fdrop(fp, td);
1648 	return (error);
1649 }
1650 
1651 int
1652 linux_sendfile(struct thread *td, struct linux_sendfile_args *arg)
1653 {
1654 	/*
1655 	 * Differences between FreeBSD and Linux sendfile:
1656 	 * - Linux doesn't send anything when count is 0 (FreeBSD uses 0 to
1657 	 *   mean send the whole file.)  In linux_sendfile given fds are still
1658 	 *   checked for validity when the count is 0.
1659 	 * - Linux can send to any fd whereas FreeBSD only supports sockets.
1660 	 *   The same restriction follows for linux_sendfile.
1661 	 * - Linux doesn't have an equivalent for FreeBSD's flags and sf_hdtr.
1662 	 * - Linux takes an offset pointer and updates it to the read location.
1663 	 *   FreeBSD takes in an offset and a 'bytes read' parameter which is
1664 	 *   only filled if it isn't NULL.  We use this parameter to update the
1665 	 *   offset pointer if it exists.
1666 	 * - Linux sendfile returns bytes read on success while FreeBSD
1667 	 *   returns 0.  We use the 'bytes read' parameter to get this value.
1668 	 */
1669 
1670 	l_loff_t offset64;
1671 	l_long offset;
1672 	int ret;
1673 	int error;
1674 
1675 	if (arg->offset != NULL) {
1676 		error = copyin(arg->offset, &offset, sizeof(offset));
1677 		if (error != 0)
1678 			return (error);
1679 		offset64 = (l_loff_t)offset;
1680 	}
1681 
1682 	ret = linux_sendfile_common(td, arg->out, arg->in,
1683 	    arg->offset != NULL ? &offset64 : NULL, arg->count);
1684 
1685 	if (arg->offset != NULL) {
1686 #if defined(__i386__) || defined(__arm__) || \
1687     (defined(__amd64__) && defined(COMPAT_LINUX32))
1688 		if (offset64 > INT32_MAX)
1689 			return (EOVERFLOW);
1690 #endif
1691 		offset = (l_long)offset64;
1692 		error = copyout(&offset, arg->offset, sizeof(offset));
1693 		if (error != 0)
1694 			return (error);
1695 	}
1696 
1697 	return (ret);
1698 }
1699 
1700 #if defined(__i386__) || defined(__arm__) || \
1701     (defined(__amd64__) && defined(COMPAT_LINUX32))
1702 
1703 int
1704 linux_sendfile64(struct thread *td, struct linux_sendfile64_args *arg)
1705 {
1706 	l_loff_t offset;
1707 	int ret;
1708 	int error;
1709 
1710 	if (arg->offset != NULL) {
1711 		error = copyin(arg->offset, &offset, sizeof(offset));
1712 		if (error != 0)
1713 			return (error);
1714 	}
1715 
1716 	ret = linux_sendfile_common(td, arg->out, arg->in,
1717 		arg->offset != NULL ? &offset : NULL, arg->count);
1718 
1719 	if (arg->offset != NULL) {
1720 		error = copyout(&offset, arg->offset, sizeof(offset));
1721 		if (error != 0)
1722 			return (error);
1723 	}
1724 
1725 	return (ret);
1726 }
1727 
1728 /* Argument list sizes for linux_socketcall */
1729 static const unsigned char lxs_args_cnt[] = {
1730 	0 /* unused*/,		3 /* socket */,
1731 	3 /* bind */,		3 /* connect */,
1732 	2 /* listen */,		3 /* accept */,
1733 	3 /* getsockname */,	3 /* getpeername */,
1734 	4 /* socketpair */,	4 /* send */,
1735 	4 /* recv */,		6 /* sendto */,
1736 	6 /* recvfrom */,	2 /* shutdown */,
1737 	5 /* setsockopt */,	5 /* getsockopt */,
1738 	3 /* sendmsg */,	3 /* recvmsg */,
1739 	4 /* accept4 */,	5 /* recvmmsg */,
1740 	4 /* sendmmsg */,	4 /* sendfile */
1741 };
1742 #define	LINUX_ARGS_CNT		(nitems(lxs_args_cnt) - 1)
1743 #define	LINUX_ARG_SIZE(x)	(lxs_args_cnt[x] * sizeof(l_ulong))
1744 
1745 int
1746 linux_socketcall(struct thread *td, struct linux_socketcall_args *args)
1747 {
1748 	l_ulong a[6];
1749 #if defined(__amd64__) && defined(COMPAT_LINUX32)
1750 	register_t l_args[6];
1751 #endif
1752 	void *arg;
1753 	int error;
1754 
1755 	if (args->what < LINUX_SOCKET || args->what > LINUX_ARGS_CNT)
1756 		return (EINVAL);
1757 	error = copyin(PTRIN(args->args), a, LINUX_ARG_SIZE(args->what));
1758 	if (error != 0)
1759 		return (error);
1760 
1761 #if defined(__amd64__) && defined(COMPAT_LINUX32)
1762 	for (int i = 0; i < lxs_args_cnt[args->what]; ++i)
1763 		l_args[i] = a[i];
1764 	arg = l_args;
1765 #else
1766 	arg = a;
1767 #endif
1768 	switch (args->what) {
1769 	case LINUX_SOCKET:
1770 		return (linux_socket(td, arg));
1771 	case LINUX_BIND:
1772 		return (linux_bind(td, arg));
1773 	case LINUX_CONNECT:
1774 		return (linux_connect(td, arg));
1775 	case LINUX_LISTEN:
1776 		return (linux_listen(td, arg));
1777 	case LINUX_ACCEPT:
1778 		return (linux_accept(td, arg));
1779 	case LINUX_GETSOCKNAME:
1780 		return (linux_getsockname(td, arg));
1781 	case LINUX_GETPEERNAME:
1782 		return (linux_getpeername(td, arg));
1783 	case LINUX_SOCKETPAIR:
1784 		return (linux_socketpair(td, arg));
1785 	case LINUX_SEND:
1786 		return (linux_send(td, arg));
1787 	case LINUX_RECV:
1788 		return (linux_recv(td, arg));
1789 	case LINUX_SENDTO:
1790 		return (linux_sendto(td, arg));
1791 	case LINUX_RECVFROM:
1792 		return (linux_recvfrom(td, arg));
1793 	case LINUX_SHUTDOWN:
1794 		return (linux_shutdown(td, arg));
1795 	case LINUX_SETSOCKOPT:
1796 		return (linux_setsockopt(td, arg));
1797 	case LINUX_GETSOCKOPT:
1798 		return (linux_getsockopt(td, arg));
1799 	case LINUX_SENDMSG:
1800 		return (linux_sendmsg(td, arg));
1801 	case LINUX_RECVMSG:
1802 		return (linux_recvmsg(td, arg));
1803 	case LINUX_ACCEPT4:
1804 		return (linux_accept4(td, arg));
1805 	case LINUX_RECVMMSG:
1806 		return (linux_recvmmsg(td, arg));
1807 	case LINUX_SENDMMSG:
1808 		return (linux_sendmmsg(td, arg));
1809 	case LINUX_SENDFILE:
1810 		return (linux_sendfile(td, arg));
1811 	}
1812 
1813 	uprintf("LINUX: 'socket' typ=%d not implemented\n", args->what);
1814 	return (ENOSYS);
1815 }
1816 #endif /* __i386__ || __arm__ || (__amd64__ && COMPAT_LINUX32) */
1817