xref: /freebsd/sys/compat/linux/linux_socket.c (revision 9e4c35f867aca020df8d01fb7371bf5ae1cc8a2d)
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/filedesc.h>
44 #include <sys/limits.h>
45 #include <sys/lock.h>
46 #include <sys/malloc.h>
47 #include <sys/mutex.h>
48 #include <sys/mbuf.h>
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/syscallsubr.h>
52 #include <sys/uio.h>
53 #include <sys/stat.h>
54 #include <sys/syslog.h>
55 #include <sys/un.h>
56 #include <sys/unistd.h>
57 
58 #include <security/audit/audit.h>
59 
60 #include <net/if.h>
61 #include <net/vnet.h>
62 #include <netinet/in.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/ip.h>
65 #include <netinet/tcp.h>
66 #ifdef INET6
67 #include <netinet/ip6.h>
68 #include <netinet6/ip6_var.h>
69 #endif
70 
71 #ifdef COMPAT_LINUX32
72 #include <machine/../linux32/linux.h>
73 #include <machine/../linux32/linux32_proto.h>
74 #else
75 #include <machine/../linux/linux.h>
76 #include <machine/../linux/linux_proto.h>
77 #endif
78 #include <compat/linux/linux_common.h>
79 #include <compat/linux/linux_file.h>
80 #include <compat/linux/linux_mib.h>
81 #include <compat/linux/linux_socket.h>
82 #include <compat/linux/linux_timer.h>
83 #include <compat/linux/linux_util.h>
84 
85 static int linux_sendmsg_common(struct thread *, l_int, struct l_msghdr *,
86 					l_uint);
87 static int linux_recvmsg_common(struct thread *, l_int, struct l_msghdr *,
88 					l_uint, struct msghdr *);
89 static int linux_set_socket_flags(int, int *);
90 
91 static int
92 linux_to_bsd_sockopt_level(int level)
93 {
94 
95 	if (level == LINUX_SOL_SOCKET)
96 		return (SOL_SOCKET);
97 	/* Remaining values are RFC-defined protocol numbers. */
98 	return (level);
99 }
100 
101 static int
102 bsd_to_linux_sockopt_level(int level)
103 {
104 
105 	if (level == SOL_SOCKET)
106 		return (LINUX_SOL_SOCKET);
107 	return (level);
108 }
109 
110 static int
111 linux_to_bsd_ip_sockopt(int opt)
112 {
113 
114 	switch (opt) {
115 	case LINUX_IP_TOS:
116 		return (IP_TOS);
117 	case LINUX_IP_TTL:
118 		return (IP_TTL);
119 	case LINUX_IP_OPTIONS:
120 		return (IP_OPTIONS);
121 	case LINUX_IP_MULTICAST_IF:
122 		return (IP_MULTICAST_IF);
123 	case LINUX_IP_MULTICAST_TTL:
124 		return (IP_MULTICAST_TTL);
125 	case LINUX_IP_MULTICAST_LOOP:
126 		return (IP_MULTICAST_LOOP);
127 	case LINUX_IP_ADD_MEMBERSHIP:
128 		return (IP_ADD_MEMBERSHIP);
129 	case LINUX_IP_DROP_MEMBERSHIP:
130 		return (IP_DROP_MEMBERSHIP);
131 	case LINUX_IP_HDRINCL:
132 		return (IP_HDRINCL);
133 	}
134 	return (-1);
135 }
136 
137 static int
138 linux_to_bsd_ip6_sockopt(int opt)
139 {
140 
141 	switch (opt) {
142 	case LINUX_IPV6_NEXTHOP:
143 		return (IPV6_NEXTHOP);
144 	case LINUX_IPV6_UNICAST_HOPS:
145 		return (IPV6_UNICAST_HOPS);
146 	case LINUX_IPV6_MULTICAST_IF:
147 		return (IPV6_MULTICAST_IF);
148 	case LINUX_IPV6_MULTICAST_HOPS:
149 		return (IPV6_MULTICAST_HOPS);
150 	case LINUX_IPV6_MULTICAST_LOOP:
151 		return (IPV6_MULTICAST_LOOP);
152 	case LINUX_IPV6_ADD_MEMBERSHIP:
153 		return (IPV6_JOIN_GROUP);
154 	case LINUX_IPV6_DROP_MEMBERSHIP:
155 		return (IPV6_LEAVE_GROUP);
156 	case LINUX_IPV6_V6ONLY:
157 		return (IPV6_V6ONLY);
158 	case LINUX_IPV6_DONTFRAG:
159 		return (IPV6_DONTFRAG);
160 #if 0
161 	case LINUX_IPV6_CHECKSUM:
162 		return (IPV6_CHECKSUM);
163 	case LINUX_IPV6_RECVPKTINFO:
164 		return (IPV6_RECVPKTINFO);
165 	case LINUX_IPV6_PKTINFO:
166 		return (IPV6_PKTINFO);
167 	case LINUX_IPV6_RECVHOPLIMIT:
168 		return (IPV6_RECVHOPLIMIT);
169 	case LINUX_IPV6_HOPLIMIT:
170 		return (IPV6_HOPLIMIT);
171 	case LINUX_IPV6_RECVHOPOPTS:
172 		return (IPV6_RECVHOPOPTS);
173 	case LINUX_IPV6_HOPOPTS:
174 		return (IPV6_HOPOPTS);
175 	case LINUX_IPV6_RTHDRDSTOPTS:
176 		return (IPV6_RTHDRDSTOPTS);
177 	case LINUX_IPV6_RECVRTHDR:
178 		return (IPV6_RECVRTHDR);
179 	case LINUX_IPV6_RTHDR:
180 		return (IPV6_RTHDR);
181 	case LINUX_IPV6_RECVDSTOPTS:
182 		return (IPV6_RECVDSTOPTS);
183 	case LINUX_IPV6_DSTOPTS:
184 		return (IPV6_DSTOPTS);
185 	case LINUX_IPV6_RECVPATHMTU:
186 		return (IPV6_RECVPATHMTU);
187 	case LINUX_IPV6_PATHMTU:
188 		return (IPV6_PATHMTU);
189 #endif
190 	}
191 	return (-1);
192 }
193 
194 static int
195 linux_to_bsd_so_sockopt(int opt)
196 {
197 
198 	switch (opt) {
199 	case LINUX_SO_DEBUG:
200 		return (SO_DEBUG);
201 	case LINUX_SO_REUSEADDR:
202 		return (SO_REUSEADDR);
203 	case LINUX_SO_TYPE:
204 		return (SO_TYPE);
205 	case LINUX_SO_ERROR:
206 		return (SO_ERROR);
207 	case LINUX_SO_DONTROUTE:
208 		return (SO_DONTROUTE);
209 	case LINUX_SO_BROADCAST:
210 		return (SO_BROADCAST);
211 	case LINUX_SO_SNDBUF:
212 	case LINUX_SO_SNDBUFFORCE:
213 		return (SO_SNDBUF);
214 	case LINUX_SO_RCVBUF:
215 	case LINUX_SO_RCVBUFFORCE:
216 		return (SO_RCVBUF);
217 	case LINUX_SO_KEEPALIVE:
218 		return (SO_KEEPALIVE);
219 	case LINUX_SO_OOBINLINE:
220 		return (SO_OOBINLINE);
221 	case LINUX_SO_LINGER:
222 		return (SO_LINGER);
223 	case LINUX_SO_REUSEPORT:
224 		return (SO_REUSEPORT_LB);
225 	case LINUX_SO_PEERCRED:
226 		return (LOCAL_PEERCRED);
227 	case LINUX_SO_RCVLOWAT:
228 		return (SO_RCVLOWAT);
229 	case LINUX_SO_SNDLOWAT:
230 		return (SO_SNDLOWAT);
231 	case LINUX_SO_RCVTIMEO:
232 		return (SO_RCVTIMEO);
233 	case LINUX_SO_SNDTIMEO:
234 		return (SO_SNDTIMEO);
235 	case LINUX_SO_TIMESTAMP:
236 		return (SO_TIMESTAMP);
237 	case LINUX_SO_ACCEPTCONN:
238 		return (SO_ACCEPTCONN);
239 	case LINUX_SO_PROTOCOL:
240 		return (SO_PROTOCOL);
241 	}
242 	return (-1);
243 }
244 
245 static int
246 linux_to_bsd_tcp_sockopt(int opt)
247 {
248 
249 	switch (opt) {
250 	case LINUX_TCP_NODELAY:
251 		return (TCP_NODELAY);
252 	case LINUX_TCP_MAXSEG:
253 		return (TCP_MAXSEG);
254 	case LINUX_TCP_CORK:
255 		return (TCP_NOPUSH);
256 	case LINUX_TCP_KEEPIDLE:
257 		return (TCP_KEEPIDLE);
258 	case LINUX_TCP_KEEPINTVL:
259 		return (TCP_KEEPINTVL);
260 	case LINUX_TCP_KEEPCNT:
261 		return (TCP_KEEPCNT);
262 	case LINUX_TCP_MD5SIG:
263 		return (TCP_MD5SIG);
264 	}
265 	return (-1);
266 }
267 
268 static int
269 linux_to_bsd_msg_flags(int flags)
270 {
271 	int ret_flags = 0;
272 
273 	if (flags & LINUX_MSG_OOB)
274 		ret_flags |= MSG_OOB;
275 	if (flags & LINUX_MSG_PEEK)
276 		ret_flags |= MSG_PEEK;
277 	if (flags & LINUX_MSG_DONTROUTE)
278 		ret_flags |= MSG_DONTROUTE;
279 	if (flags & LINUX_MSG_CTRUNC)
280 		ret_flags |= MSG_CTRUNC;
281 	if (flags & LINUX_MSG_TRUNC)
282 		ret_flags |= MSG_TRUNC;
283 	if (flags & LINUX_MSG_DONTWAIT)
284 		ret_flags |= MSG_DONTWAIT;
285 	if (flags & LINUX_MSG_EOR)
286 		ret_flags |= MSG_EOR;
287 	if (flags & LINUX_MSG_WAITALL)
288 		ret_flags |= MSG_WAITALL;
289 	if (flags & LINUX_MSG_NOSIGNAL)
290 		ret_flags |= MSG_NOSIGNAL;
291 #if 0 /* not handled */
292 	if (flags & LINUX_MSG_PROXY)
293 		;
294 	if (flags & LINUX_MSG_FIN)
295 		;
296 	if (flags & LINUX_MSG_SYN)
297 		;
298 	if (flags & LINUX_MSG_CONFIRM)
299 		;
300 	if (flags & LINUX_MSG_RST)
301 		;
302 	if (flags & LINUX_MSG_ERRQUEUE)
303 		;
304 #endif
305 	return (ret_flags);
306 }
307 
308 static int
309 linux_to_bsd_cmsg_type(int cmsg_type)
310 {
311 
312 	switch (cmsg_type) {
313 	case LINUX_SCM_RIGHTS:
314 		return (SCM_RIGHTS);
315 	case LINUX_SCM_CREDENTIALS:
316 		return (SCM_CREDS);
317 	}
318 	return (-1);
319 }
320 
321 static int
322 bsd_to_linux_cmsg_type(int cmsg_type)
323 {
324 
325 	switch (cmsg_type) {
326 	case SCM_RIGHTS:
327 		return (LINUX_SCM_RIGHTS);
328 	case SCM_CREDS:
329 		return (LINUX_SCM_CREDENTIALS);
330 	case SCM_TIMESTAMP:
331 		return (LINUX_SCM_TIMESTAMP);
332 	}
333 	return (-1);
334 }
335 
336 static int
337 linux_to_bsd_msghdr(struct msghdr *bhdr, const struct l_msghdr *lhdr)
338 {
339 	if (lhdr->msg_controllen > INT_MAX)
340 		return (ENOBUFS);
341 
342 	bhdr->msg_name		= PTRIN(lhdr->msg_name);
343 	bhdr->msg_namelen	= lhdr->msg_namelen;
344 	bhdr->msg_iov		= PTRIN(lhdr->msg_iov);
345 	bhdr->msg_iovlen	= lhdr->msg_iovlen;
346 	bhdr->msg_control	= PTRIN(lhdr->msg_control);
347 
348 	/*
349 	 * msg_controllen is skipped since BSD and LINUX control messages
350 	 * are potentially different sizes (e.g. the cred structure used
351 	 * by SCM_CREDS is different between the two operating system).
352 	 *
353 	 * The caller can set it (if necessary) after converting all the
354 	 * control messages.
355 	 */
356 
357 	bhdr->msg_flags		= linux_to_bsd_msg_flags(lhdr->msg_flags);
358 	return (0);
359 }
360 
361 static int
362 bsd_to_linux_msghdr(const struct msghdr *bhdr, struct l_msghdr *lhdr)
363 {
364 	lhdr->msg_name		= PTROUT(bhdr->msg_name);
365 	lhdr->msg_namelen	= bhdr->msg_namelen;
366 	lhdr->msg_iov		= PTROUT(bhdr->msg_iov);
367 	lhdr->msg_iovlen	= bhdr->msg_iovlen;
368 	lhdr->msg_control	= PTROUT(bhdr->msg_control);
369 
370 	/*
371 	 * msg_controllen is skipped since BSD and LINUX control messages
372 	 * are potentially different sizes (e.g. the cred structure used
373 	 * by SCM_CREDS is different between the two operating system).
374 	 *
375 	 * The caller can set it (if necessary) after converting all the
376 	 * control messages.
377 	 */
378 
379 	/* msg_flags skipped */
380 	return (0);
381 }
382 
383 static int
384 linux_set_socket_flags(int lflags, int *flags)
385 {
386 
387 	if (lflags & ~(LINUX_SOCK_CLOEXEC | LINUX_SOCK_NONBLOCK))
388 		return (EINVAL);
389 	if (lflags & LINUX_SOCK_NONBLOCK)
390 		*flags |= SOCK_NONBLOCK;
391 	if (lflags & LINUX_SOCK_CLOEXEC)
392 		*flags |= SOCK_CLOEXEC;
393 	return (0);
394 }
395 
396 static int
397 linux_sendit(struct thread *td, int s, struct msghdr *mp, int flags,
398     struct mbuf *control, enum uio_seg segflg)
399 {
400 	struct sockaddr *to;
401 	int error, len;
402 
403 	if (mp->msg_name != NULL) {
404 		len = mp->msg_namelen;
405 		error = linux_to_bsd_sockaddr(mp->msg_name, &to, &len);
406 		if (error != 0)
407 			return (error);
408 		mp->msg_name = to;
409 	} else
410 		to = NULL;
411 
412 	error = kern_sendit(td, s, mp, linux_to_bsd_msg_flags(flags), control,
413 	    segflg);
414 
415 	if (to)
416 		free(to, M_SONAME);
417 	return (error);
418 }
419 
420 /* Return 0 if IP_HDRINCL is set for the given socket. */
421 static int
422 linux_check_hdrincl(struct thread *td, int s)
423 {
424 	int error, optval;
425 	socklen_t size_val;
426 
427 	size_val = sizeof(optval);
428 	error = kern_getsockopt(td, s, IPPROTO_IP, IP_HDRINCL,
429 	    &optval, UIO_SYSSPACE, &size_val);
430 	if (error != 0)
431 		return (error);
432 
433 	return (optval == 0);
434 }
435 
436 /*
437  * Updated sendto() when IP_HDRINCL is set:
438  * tweak endian-dependent fields in the IP packet.
439  */
440 static int
441 linux_sendto_hdrincl(struct thread *td, struct linux_sendto_args *linux_args)
442 {
443 /*
444  * linux_ip_copysize defines how many bytes we should copy
445  * from the beginning of the IP packet before we customize it for BSD.
446  * It should include all the fields we modify (ip_len and ip_off).
447  */
448 #define linux_ip_copysize	8
449 
450 	struct ip *packet;
451 	struct msghdr msg;
452 	struct iovec aiov[1];
453 	int error;
454 
455 	/* Check that the packet isn't too big or too small. */
456 	if (linux_args->len < linux_ip_copysize ||
457 	    linux_args->len > IP_MAXPACKET)
458 		return (EINVAL);
459 
460 	packet = (struct ip *)malloc(linux_args->len, M_LINUX, M_WAITOK);
461 
462 	/* Make kernel copy of the packet to be sent */
463 	if ((error = copyin(PTRIN(linux_args->msg), packet,
464 	    linux_args->len)))
465 		goto goout;
466 
467 	/* Convert fields from Linux to BSD raw IP socket format */
468 	packet->ip_len = linux_args->len;
469 	packet->ip_off = ntohs(packet->ip_off);
470 
471 	/* Prepare the msghdr and iovec structures describing the new packet */
472 	msg.msg_name = PTRIN(linux_args->to);
473 	msg.msg_namelen = linux_args->tolen;
474 	msg.msg_iov = aiov;
475 	msg.msg_iovlen = 1;
476 	msg.msg_control = NULL;
477 	msg.msg_flags = 0;
478 	aiov[0].iov_base = (char *)packet;
479 	aiov[0].iov_len = linux_args->len;
480 	error = linux_sendit(td, linux_args->s, &msg, linux_args->flags,
481 	    NULL, UIO_SYSSPACE);
482 goout:
483 	free(packet, M_LINUX);
484 	return (error);
485 }
486 
487 int
488 linux_socket(struct thread *td, struct linux_socket_args *args)
489 {
490 	int domain, retval_socket, type;
491 
492 	type = args->type & LINUX_SOCK_TYPE_MASK;
493 	if (type < 0 || type > LINUX_SOCK_MAX)
494 		return (EINVAL);
495 	retval_socket = linux_set_socket_flags(args->type & ~LINUX_SOCK_TYPE_MASK,
496 		&type);
497 	if (retval_socket != 0)
498 		return (retval_socket);
499 	domain = linux_to_bsd_domain(args->domain);
500 	if (domain == -1)
501 		return (EAFNOSUPPORT);
502 
503 	retval_socket = kern_socket(td, domain, type, args->protocol);
504 	if (retval_socket)
505 		return (retval_socket);
506 
507 	if (type == SOCK_RAW
508 	    && (args->protocol == IPPROTO_RAW || args->protocol == 0)
509 	    && domain == PF_INET) {
510 		/* It's a raw IP socket: set the IP_HDRINCL option. */
511 		int hdrincl;
512 
513 		hdrincl = 1;
514 		/* We ignore any error returned by kern_setsockopt() */
515 		kern_setsockopt(td, td->td_retval[0], IPPROTO_IP, IP_HDRINCL,
516 		    &hdrincl, UIO_SYSSPACE, sizeof(hdrincl));
517 	}
518 #ifdef INET6
519 	/*
520 	 * Linux AF_INET6 socket has IPV6_V6ONLY setsockopt set to 0 by default
521 	 * and some apps depend on this. So, set V6ONLY to 0 for Linux apps.
522 	 * For simplicity we do this unconditionally of the net.inet6.ip6.v6only
523 	 * sysctl value.
524 	 */
525 	if (domain == PF_INET6) {
526 		int v6only;
527 
528 		v6only = 0;
529 		/* We ignore any error returned by setsockopt() */
530 		kern_setsockopt(td, td->td_retval[0], IPPROTO_IPV6, IPV6_V6ONLY,
531 		    &v6only, UIO_SYSSPACE, sizeof(v6only));
532 	}
533 #endif
534 
535 	return (retval_socket);
536 }
537 
538 int
539 linux_bind(struct thread *td, struct linux_bind_args *args)
540 {
541 	struct sockaddr *sa;
542 	int error;
543 
544 	error = linux_to_bsd_sockaddr(PTRIN(args->name), &sa,
545 	    &args->namelen);
546 	if (error != 0)
547 		return (error);
548 
549 	error = kern_bindat(td, AT_FDCWD, args->s, sa);
550 	free(sa, M_SONAME);
551 
552 	/* XXX */
553 	if (error == EADDRNOTAVAIL && args->namelen != sizeof(struct sockaddr_in))
554 		return (EINVAL);
555 	return (error);
556 }
557 
558 int
559 linux_connect(struct thread *td, struct linux_connect_args *args)
560 {
561 	struct socket *so;
562 	struct sockaddr *sa;
563 	struct file *fp;
564 	u_int fflag;
565 	int error;
566 
567 	error = linux_to_bsd_sockaddr(PTRIN(args->name), &sa,
568 	    &args->namelen);
569 	if (error != 0)
570 		return (error);
571 
572 	error = kern_connectat(td, AT_FDCWD, args->s, sa);
573 	free(sa, M_SONAME);
574 	if (error != EISCONN)
575 		return (error);
576 
577 	/*
578 	 * Linux doesn't return EISCONN the first time it occurs,
579 	 * when on a non-blocking socket. Instead it returns the
580 	 * error getsockopt(SOL_SOCKET, SO_ERROR) would return on BSD.
581 	 */
582 	error = getsock_cap(td, args->s, &cap_connect_rights,
583 	    &fp, &fflag, NULL);
584 	if (error != 0)
585 		return (error);
586 
587 	error = EISCONN;
588 	so = fp->f_data;
589 	if (fflag & FNONBLOCK) {
590 		SOCK_LOCK(so);
591 		if (so->so_emuldata == 0)
592 			error = so->so_error;
593 		so->so_emuldata = (void *)1;
594 		SOCK_UNLOCK(so);
595 	}
596 	fdrop(fp, td);
597 
598 	return (error);
599 }
600 
601 int
602 linux_listen(struct thread *td, struct linux_listen_args *args)
603 {
604 
605 	return (kern_listen(td, args->s, args->backlog));
606 }
607 
608 static int
609 linux_accept_common(struct thread *td, int s, l_uintptr_t addr,
610     l_uintptr_t namelen, int flags)
611 {
612 	struct l_sockaddr *lsa;
613 	struct sockaddr *sa;
614 	struct file *fp, *fp1;
615 	int bflags, len;
616 	struct socket *so;
617 	int error, error1;
618 
619 	bflags = 0;
620 	fp = NULL;
621 	sa = NULL;
622 
623 	error = linux_set_socket_flags(flags, &bflags);
624 	if (error != 0)
625 		return (error);
626 
627 	if (PTRIN(addr) == NULL) {
628 		len = 0;
629 		error = kern_accept4(td, s, NULL, NULL, bflags, NULL);
630 	} else {
631 		error = copyin(PTRIN(namelen), &len, sizeof(len));
632 		if (error != 0)
633 			return (error);
634 		if (len < 0)
635 			return (EINVAL);
636 		error = kern_accept4(td, s, &sa, &len, bflags, &fp);
637 	}
638 
639 	/*
640 	 * Translate errno values into ones used by Linux.
641 	 */
642 	if (error != 0) {
643 		/*
644 		 * XXX. This is wrong, different sockaddr structures
645 		 * have different sizes.
646 		 */
647 		switch (error) {
648 		case EFAULT:
649 			if (namelen != sizeof(struct sockaddr_in))
650 				error = EINVAL;
651 			break;
652 		case EINVAL:
653 			error1 = getsock_cap(td, s, &cap_accept_rights, &fp1, NULL, NULL);
654 			if (error1 != 0) {
655 				error = error1;
656 				break;
657 			}
658 			so = fp1->f_data;
659 			if (so->so_type == SOCK_DGRAM)
660 				error = EOPNOTSUPP;
661 			fdrop(fp1, td);
662 			break;
663 		}
664 		return (error);
665 	}
666 
667 	if (len != 0) {
668 		error = bsd_to_linux_sockaddr(sa, &lsa, len);
669 		if (error == 0)
670 			error = copyout(lsa, PTRIN(addr), len);
671 		free(lsa, M_SONAME);
672 
673 		/*
674 		 * XXX: We should also copyout the len, shouldn't we?
675 		 */
676 
677 		if (error != 0) {
678 			fdclose(td, fp, td->td_retval[0]);
679 			td->td_retval[0] = 0;
680 		}
681 	}
682 	if (fp != NULL)
683 		fdrop(fp, td);
684 	free(sa, M_SONAME);
685 	return (error);
686 }
687 
688 int
689 linux_accept(struct thread *td, struct linux_accept_args *args)
690 {
691 
692 	return (linux_accept_common(td, args->s, args->addr,
693 	    args->namelen, 0));
694 }
695 
696 int
697 linux_accept4(struct thread *td, struct linux_accept4_args *args)
698 {
699 
700 	return (linux_accept_common(td, args->s, args->addr,
701 	    args->namelen, args->flags));
702 }
703 
704 int
705 linux_getsockname(struct thread *td, struct linux_getsockname_args *args)
706 {
707 	struct l_sockaddr *lsa;
708 	struct sockaddr *sa;
709 	int len, error;
710 
711 	error = copyin(PTRIN(args->namelen), &len, sizeof(len));
712 	if (error != 0)
713 		return (error);
714 
715 	error = kern_getsockname(td, args->s, &sa, &len);
716 	if (error != 0)
717 		return (error);
718 
719 	if (len != 0) {
720 		error = bsd_to_linux_sockaddr(sa, &lsa, len);
721 		if (error == 0)
722 			error = copyout(lsa, PTRIN(args->addr),
723 			    len);
724 		free(lsa, M_SONAME);
725 	}
726 
727 	free(sa, M_SONAME);
728 	if (error == 0)
729 		error = copyout(&len, PTRIN(args->namelen), sizeof(len));
730 	return (error);
731 }
732 
733 int
734 linux_getpeername(struct thread *td, struct linux_getpeername_args *args)
735 {
736 	struct l_sockaddr *lsa;
737 	struct sockaddr *sa;
738 	int len, error;
739 
740 	error = copyin(PTRIN(args->namelen), &len, sizeof(len));
741 	if (error != 0)
742 		return (error);
743 	if (len < 0)
744 		return (EINVAL);
745 
746 	error = kern_getpeername(td, args->s, &sa, &len);
747 	if (error != 0)
748 		return (error);
749 
750 	if (len != 0) {
751 		error = bsd_to_linux_sockaddr(sa, &lsa, len);
752 		if (error == 0)
753 			error = copyout(lsa, PTRIN(args->addr),
754 			    len);
755 		free(lsa, M_SONAME);
756 	}
757 
758 	free(sa, M_SONAME);
759 	if (error == 0)
760 		error = copyout(&len, PTRIN(args->namelen), sizeof(len));
761 	return (error);
762 }
763 
764 int
765 linux_socketpair(struct thread *td, struct linux_socketpair_args *args)
766 {
767 	int domain, error, sv[2], type;
768 
769 	domain = linux_to_bsd_domain(args->domain);
770 	if (domain != PF_LOCAL)
771 		return (EAFNOSUPPORT);
772 	type = args->type & LINUX_SOCK_TYPE_MASK;
773 	if (type < 0 || type > LINUX_SOCK_MAX)
774 		return (EINVAL);
775 	error = linux_set_socket_flags(args->type & ~LINUX_SOCK_TYPE_MASK,
776 	    &type);
777 	if (error != 0)
778 		return (error);
779 	if (args->protocol != 0 && args->protocol != PF_UNIX) {
780 		/*
781 		 * Use of PF_UNIX as protocol argument is not right,
782 		 * but Linux does it.
783 		 * Do not map PF_UNIX as its Linux value is identical
784 		 * to FreeBSD one.
785 		 */
786 		return (EPROTONOSUPPORT);
787 	}
788 	error = kern_socketpair(td, domain, type, 0, sv);
789 	if (error != 0)
790                 return (error);
791         error = copyout(sv, PTRIN(args->rsv), 2 * sizeof(int));
792         if (error != 0) {
793                 (void)kern_close(td, sv[0]);
794                 (void)kern_close(td, sv[1]);
795         }
796 	return (error);
797 }
798 
799 #if defined(__i386__) || (defined(__amd64__) && defined(COMPAT_LINUX32))
800 struct linux_send_args {
801 	register_t s;
802 	register_t msg;
803 	register_t len;
804 	register_t flags;
805 };
806 
807 static int
808 linux_send(struct thread *td, struct linux_send_args *args)
809 {
810 	struct sendto_args /* {
811 		int s;
812 		caddr_t buf;
813 		int len;
814 		int flags;
815 		caddr_t to;
816 		int tolen;
817 	} */ bsd_args;
818 	struct file *fp;
819 	int error, fflag;
820 
821 	bsd_args.s = args->s;
822 	bsd_args.buf = (caddr_t)PTRIN(args->msg);
823 	bsd_args.len = args->len;
824 	bsd_args.flags = args->flags;
825 	bsd_args.to = NULL;
826 	bsd_args.tolen = 0;
827 	error = sys_sendto(td, &bsd_args);
828 	if (error == ENOTCONN) {
829 		/*
830 		 * Linux doesn't return ENOTCONN for non-blocking sockets.
831 		 * Instead it returns the EAGAIN.
832 		 */
833 		error = getsock_cap(td, args->s, &cap_send_rights, &fp,
834 		    &fflag, NULL);
835 		if (error == 0) {
836 			if (fflag & FNONBLOCK)
837 				error = EAGAIN;
838 			fdrop(fp, td);
839 		}
840 	}
841 	return (error);
842 }
843 
844 struct linux_recv_args {
845 	register_t s;
846 	register_t msg;
847 	register_t len;
848 	register_t flags;
849 };
850 
851 static int
852 linux_recv(struct thread *td, struct linux_recv_args *args)
853 {
854 	struct recvfrom_args /* {
855 		int s;
856 		caddr_t buf;
857 		int len;
858 		int flags;
859 		struct sockaddr *from;
860 		socklen_t fromlenaddr;
861 	} */ bsd_args;
862 
863 	bsd_args.s = args->s;
864 	bsd_args.buf = (caddr_t)PTRIN(args->msg);
865 	bsd_args.len = args->len;
866 	bsd_args.flags = linux_to_bsd_msg_flags(args->flags);
867 	bsd_args.from = NULL;
868 	bsd_args.fromlenaddr = 0;
869 	return (sys_recvfrom(td, &bsd_args));
870 }
871 #endif /* __i386__ || (__amd64__ && COMPAT_LINUX32) */
872 
873 int
874 linux_sendto(struct thread *td, struct linux_sendto_args *args)
875 {
876 	struct msghdr msg;
877 	struct iovec aiov;
878 
879 	if (linux_check_hdrincl(td, args->s) == 0)
880 		/* IP_HDRINCL set, tweak the packet before sending */
881 		return (linux_sendto_hdrincl(td, args));
882 
883 	msg.msg_name = PTRIN(args->to);
884 	msg.msg_namelen = args->tolen;
885 	msg.msg_iov = &aiov;
886 	msg.msg_iovlen = 1;
887 	msg.msg_control = NULL;
888 	msg.msg_flags = 0;
889 	aiov.iov_base = PTRIN(args->msg);
890 	aiov.iov_len = args->len;
891 	return (linux_sendit(td, args->s, &msg, args->flags, NULL,
892 	    UIO_USERSPACE));
893 }
894 
895 int
896 linux_recvfrom(struct thread *td, struct linux_recvfrom_args *args)
897 {
898 	struct l_sockaddr *lsa;
899 	struct sockaddr *sa;
900 	struct msghdr msg;
901 	struct iovec aiov;
902 	int error, fromlen;
903 
904 	if (PTRIN(args->fromlen) != NULL) {
905 		error = copyin(PTRIN(args->fromlen), &fromlen,
906 		    sizeof(fromlen));
907 		if (error != 0)
908 			return (error);
909 		if (fromlen < 0)
910 			return (EINVAL);
911 		sa = malloc(fromlen, M_SONAME, M_WAITOK);
912 	} else {
913 		fromlen = 0;
914 		sa = NULL;
915 	}
916 
917 	msg.msg_name = sa;
918 	msg.msg_namelen = fromlen;
919 	msg.msg_iov = &aiov;
920 	msg.msg_iovlen = 1;
921 	aiov.iov_base = PTRIN(args->buf);
922 	aiov.iov_len = args->len;
923 	msg.msg_control = 0;
924 	msg.msg_flags = linux_to_bsd_msg_flags(args->flags);
925 
926 	error = kern_recvit(td, args->s, &msg, UIO_SYSSPACE, NULL);
927 	if (error != 0)
928 		goto out;
929 
930 	if (PTRIN(args->from) != NULL) {
931 		error = bsd_to_linux_sockaddr(sa, &lsa, msg.msg_namelen);
932 		if (error == 0)
933 			error = copyout(lsa, PTRIN(args->from),
934 			    msg.msg_namelen);
935 		free(lsa, M_SONAME);
936 	}
937 
938 	if (error == 0 && PTRIN(args->fromlen) != NULL)
939 		error = copyout(&msg.msg_namelen, PTRIN(args->fromlen),
940 		    sizeof(msg.msg_namelen));
941 out:
942 	free(sa, M_SONAME);
943 	return (error);
944 }
945 
946 static int
947 linux_sendmsg_common(struct thread *td, l_int s, struct l_msghdr *msghdr,
948     l_uint flags)
949 {
950 	struct cmsghdr *cmsg;
951 	struct mbuf *control;
952 	struct msghdr msg;
953 	struct l_cmsghdr linux_cmsg;
954 	struct l_cmsghdr *ptr_cmsg;
955 	struct l_msghdr linux_msghdr;
956 	struct iovec *iov;
957 	socklen_t datalen;
958 	struct sockaddr *sa;
959 	struct socket *so;
960 	sa_family_t sa_family;
961 	struct file *fp;
962 	void *data;
963 	l_size_t len;
964 	l_size_t clen;
965 	int error, fflag;
966 
967 	error = copyin(msghdr, &linux_msghdr, sizeof(linux_msghdr));
968 	if (error != 0)
969 		return (error);
970 
971 	/*
972 	 * Some Linux applications (ping) define a non-NULL control data
973 	 * pointer, but a msg_controllen of 0, which is not allowed in the
974 	 * FreeBSD system call interface.  NULL the msg_control pointer in
975 	 * order to handle this case.  This should be checked, but allows the
976 	 * Linux ping to work.
977 	 */
978 	if (PTRIN(linux_msghdr.msg_control) != NULL &&
979 	    linux_msghdr.msg_controllen == 0)
980 		linux_msghdr.msg_control = PTROUT(NULL);
981 
982 	error = linux_to_bsd_msghdr(&msg, &linux_msghdr);
983 	if (error != 0)
984 		return (error);
985 
986 #ifdef COMPAT_LINUX32
987 	error = linux32_copyiniov(PTRIN(msg.msg_iov), msg.msg_iovlen,
988 	    &iov, EMSGSIZE);
989 #else
990 	error = copyiniov(msg.msg_iov, msg.msg_iovlen, &iov, EMSGSIZE);
991 #endif
992 	if (error != 0)
993 		return (error);
994 
995 	control = NULL;
996 
997 	error = kern_getsockname(td, s, &sa, &datalen);
998 	if (error != 0)
999 		goto bad;
1000 	sa_family = sa->sa_family;
1001 	free(sa, M_SONAME);
1002 
1003 	if (flags & LINUX_MSG_OOB) {
1004 		error = EOPNOTSUPP;
1005 		if (sa_family == AF_UNIX)
1006 			goto bad;
1007 
1008 		error = getsock_cap(td, s, &cap_send_rights, &fp,
1009 		    &fflag, NULL);
1010 		if (error != 0)
1011 			goto bad;
1012 		so = fp->f_data;
1013 		if (so->so_type != SOCK_STREAM)
1014 			error = EOPNOTSUPP;
1015 		fdrop(fp, td);
1016 		if (error != 0)
1017 			goto bad;
1018 	}
1019 
1020 	if (linux_msghdr.msg_controllen >= sizeof(struct l_cmsghdr)) {
1021 		error = ENOBUFS;
1022 		control = m_get(M_WAITOK, MT_CONTROL);
1023 		MCLGET(control, M_WAITOK);
1024 		data = mtod(control, void *);
1025 		datalen = 0;
1026 
1027 		ptr_cmsg = PTRIN(linux_msghdr.msg_control);
1028 		clen = linux_msghdr.msg_controllen;
1029 		do {
1030 			error = copyin(ptr_cmsg, &linux_cmsg,
1031 			    sizeof(struct l_cmsghdr));
1032 			if (error != 0)
1033 				goto bad;
1034 
1035 			error = EINVAL;
1036 			if (linux_cmsg.cmsg_len < sizeof(struct l_cmsghdr) ||
1037 			    linux_cmsg.cmsg_len > clen)
1038 				goto bad;
1039 
1040 			if (datalen + CMSG_HDRSZ > MCLBYTES)
1041 				goto bad;
1042 
1043 			/*
1044 			 * Now we support only SCM_RIGHTS and SCM_CRED,
1045 			 * so return EINVAL in any other cmsg_type
1046 			 */
1047 			cmsg = data;
1048 			cmsg->cmsg_type =
1049 			    linux_to_bsd_cmsg_type(linux_cmsg.cmsg_type);
1050 			cmsg->cmsg_level =
1051 			    linux_to_bsd_sockopt_level(linux_cmsg.cmsg_level);
1052 			if (cmsg->cmsg_type == -1
1053 			    || cmsg->cmsg_level != SOL_SOCKET) {
1054 				linux_msg(curthread,
1055 				    "unsupported sendmsg cmsg level %d type %d",
1056 				    linux_cmsg.cmsg_level, linux_cmsg.cmsg_type);
1057 				goto bad;
1058 			}
1059 
1060 			/*
1061 			 * Some applications (e.g. pulseaudio) attempt to
1062 			 * send ancillary data even if the underlying protocol
1063 			 * doesn't support it which is not allowed in the
1064 			 * FreeBSD system call interface.
1065 			 */
1066 			if (sa_family != AF_UNIX)
1067 				goto next;
1068 
1069 			if (cmsg->cmsg_type == SCM_CREDS) {
1070 				len = sizeof(struct cmsgcred);
1071 				if (datalen + CMSG_SPACE(len) > MCLBYTES)
1072 					goto bad;
1073 
1074 				/*
1075 				 * The lower levels will fill in the structure
1076 				 */
1077 				memset(CMSG_DATA(data), 0, len);
1078 			} else {
1079 				len = linux_cmsg.cmsg_len - L_CMSG_HDRSZ;
1080 				if (datalen + CMSG_SPACE(len) < datalen ||
1081 				    datalen + CMSG_SPACE(len) > MCLBYTES)
1082 					goto bad;
1083 
1084 				error = copyin(LINUX_CMSG_DATA(ptr_cmsg),
1085 				    CMSG_DATA(data), len);
1086 				if (error != 0)
1087 					goto bad;
1088 			}
1089 
1090 			cmsg->cmsg_len = CMSG_LEN(len);
1091 			data = (char *)data + CMSG_SPACE(len);
1092 			datalen += CMSG_SPACE(len);
1093 
1094 next:
1095 			if (clen <= LINUX_CMSG_ALIGN(linux_cmsg.cmsg_len))
1096 				break;
1097 
1098 			clen -= LINUX_CMSG_ALIGN(linux_cmsg.cmsg_len);
1099 			ptr_cmsg = (struct l_cmsghdr *)((char *)ptr_cmsg +
1100 			    LINUX_CMSG_ALIGN(linux_cmsg.cmsg_len));
1101 		} while(clen >= sizeof(struct l_cmsghdr));
1102 
1103 		control->m_len = datalen;
1104 		if (datalen == 0) {
1105 			m_freem(control);
1106 			control = NULL;
1107 		}
1108 	}
1109 
1110 	msg.msg_iov = iov;
1111 	msg.msg_flags = 0;
1112 	error = linux_sendit(td, s, &msg, flags, control, UIO_USERSPACE);
1113 	control = NULL;
1114 
1115 bad:
1116 	m_freem(control);
1117 	free(iov, M_IOV);
1118 	return (error);
1119 }
1120 
1121 int
1122 linux_sendmsg(struct thread *td, struct linux_sendmsg_args *args)
1123 {
1124 
1125 	return (linux_sendmsg_common(td, args->s, PTRIN(args->msg),
1126 	    args->flags));
1127 }
1128 
1129 int
1130 linux_sendmmsg(struct thread *td, struct linux_sendmmsg_args *args)
1131 {
1132 	struct l_mmsghdr *msg;
1133 	l_uint retval;
1134 	int error, datagrams;
1135 
1136 	if (args->vlen > UIO_MAXIOV)
1137 		args->vlen = UIO_MAXIOV;
1138 
1139 	msg = PTRIN(args->msg);
1140 	datagrams = 0;
1141 	while (datagrams < args->vlen) {
1142 		error = linux_sendmsg_common(td, args->s, &msg->msg_hdr,
1143 		    args->flags);
1144 		if (error != 0)
1145 			break;
1146 
1147 		retval = td->td_retval[0];
1148 		error = copyout(&retval, &msg->msg_len, sizeof(msg->msg_len));
1149 		if (error != 0)
1150 			break;
1151 		++msg;
1152 		++datagrams;
1153 	}
1154 	if (error == 0)
1155 		td->td_retval[0] = datagrams;
1156 	return (error);
1157 }
1158 
1159 static int
1160 linux_recvmsg_common(struct thread *td, l_int s, struct l_msghdr *msghdr,
1161     l_uint flags, struct msghdr *msg)
1162 {
1163 	struct cmsghdr *cm;
1164 	struct cmsgcred *cmcred;
1165 	struct l_cmsghdr *linux_cmsg = NULL;
1166 	struct l_ucred linux_ucred;
1167 	socklen_t datalen, maxlen, outlen;
1168 	struct l_msghdr linux_msghdr;
1169 	struct iovec *iov, *uiov;
1170 	struct mbuf *control = NULL;
1171 	struct mbuf **controlp;
1172 	struct timeval *ftmvl;
1173 	struct l_sockaddr *lsa;
1174 	struct sockaddr *sa;
1175 	l_timeval ltmvl;
1176 	caddr_t outbuf;
1177 	void *data;
1178 	int error, i, fd, fds, *fdp;
1179 
1180 	error = copyin(msghdr, &linux_msghdr, sizeof(linux_msghdr));
1181 	if (error != 0)
1182 		return (error);
1183 
1184 	error = linux_to_bsd_msghdr(msg, &linux_msghdr);
1185 	if (error != 0)
1186 		return (error);
1187 
1188 #ifdef COMPAT_LINUX32
1189 	error = linux32_copyiniov(PTRIN(msg->msg_iov), msg->msg_iovlen,
1190 	    &iov, EMSGSIZE);
1191 #else
1192 	error = copyiniov(msg->msg_iov, msg->msg_iovlen, &iov, EMSGSIZE);
1193 #endif
1194 	if (error != 0)
1195 		return (error);
1196 
1197 	if (msg->msg_name != NULL && msg->msg_namelen > 0) {
1198 		msg->msg_namelen = min(msg->msg_namelen, SOCK_MAXADDRLEN);
1199 		sa = malloc(msg->msg_namelen, M_SONAME, M_WAITOK);
1200 		msg->msg_name = sa;
1201 	} else {
1202 		sa = NULL;
1203 		msg->msg_name = NULL;
1204 	}
1205 
1206 	uiov = msg->msg_iov;
1207 	msg->msg_iov = iov;
1208 	controlp = (msg->msg_control != NULL) ? &control : NULL;
1209 	error = kern_recvit(td, s, msg, UIO_SYSSPACE, controlp);
1210 	msg->msg_iov = uiov;
1211 	if (error != 0)
1212 		goto bad;
1213 
1214 	/*
1215 	 * Note that kern_recvit() updates msg->msg_namelen.
1216 	 */
1217 	if (msg->msg_name != NULL && msg->msg_namelen > 0) {
1218 		msg->msg_name = PTRIN(linux_msghdr.msg_name);
1219 		error = bsd_to_linux_sockaddr(sa, &lsa, msg->msg_namelen);
1220 		if (error == 0)
1221 			error = copyout(lsa, PTRIN(msg->msg_name),
1222 			    msg->msg_namelen);
1223 		free(lsa, M_SONAME);
1224 		if (error != 0)
1225 			goto bad;
1226 	}
1227 
1228 	error = bsd_to_linux_msghdr(msg, &linux_msghdr);
1229 	if (error != 0)
1230 		goto bad;
1231 
1232 	maxlen = linux_msghdr.msg_controllen;
1233 	linux_msghdr.msg_controllen = 0;
1234 	if (control) {
1235 		linux_cmsg = malloc(L_CMSG_HDRSZ, M_LINUX, M_WAITOK | M_ZERO);
1236 
1237 		msg->msg_control = mtod(control, struct cmsghdr *);
1238 		msg->msg_controllen = control->m_len;
1239 
1240 		cm = CMSG_FIRSTHDR(msg);
1241 		outbuf = PTRIN(linux_msghdr.msg_control);
1242 		outlen = 0;
1243 		while (cm != NULL) {
1244 			linux_cmsg->cmsg_type =
1245 			    bsd_to_linux_cmsg_type(cm->cmsg_type);
1246 			linux_cmsg->cmsg_level =
1247 			    bsd_to_linux_sockopt_level(cm->cmsg_level);
1248 			if (linux_cmsg->cmsg_type == -1 ||
1249 			    cm->cmsg_level != SOL_SOCKET) {
1250 				linux_msg(curthread,
1251 				    "unsupported recvmsg cmsg level %d type %d",
1252 				    cm->cmsg_level, cm->cmsg_type);
1253 				error = EINVAL;
1254 				goto bad;
1255 			}
1256 
1257 			data = CMSG_DATA(cm);
1258 			datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1259 
1260 			switch (cm->cmsg_type) {
1261 			case SCM_RIGHTS:
1262 				if (flags & LINUX_MSG_CMSG_CLOEXEC) {
1263 					fds = datalen / sizeof(int);
1264 					fdp = data;
1265 					for (i = 0; i < fds; i++) {
1266 						fd = *fdp++;
1267 						(void)kern_fcntl(td, fd,
1268 						    F_SETFD, FD_CLOEXEC);
1269 					}
1270 				}
1271 				break;
1272 
1273 			case SCM_CREDS:
1274 				/*
1275 				 * Currently LOCAL_CREDS is never in
1276 				 * effect for Linux so no need to worry
1277 				 * about sockcred
1278 				 */
1279 				if (datalen != sizeof(*cmcred)) {
1280 					error = EMSGSIZE;
1281 					goto bad;
1282 				}
1283 				cmcred = (struct cmsgcred *)data;
1284 				bzero(&linux_ucred, sizeof(linux_ucred));
1285 				linux_ucred.pid = cmcred->cmcred_pid;
1286 				linux_ucred.uid = cmcred->cmcred_uid;
1287 				linux_ucred.gid = cmcred->cmcred_gid;
1288 				data = &linux_ucred;
1289 				datalen = sizeof(linux_ucred);
1290 				break;
1291 
1292 			case SCM_TIMESTAMP:
1293 				if (datalen != sizeof(struct timeval)) {
1294 					error = EMSGSIZE;
1295 					goto bad;
1296 				}
1297 				ftmvl = (struct timeval *)data;
1298 				ltmvl.tv_sec = ftmvl->tv_sec;
1299 				ltmvl.tv_usec = ftmvl->tv_usec;
1300 				data = &ltmvl;
1301 				datalen = sizeof(ltmvl);
1302 				break;
1303 			}
1304 
1305 			if (outlen + LINUX_CMSG_LEN(datalen) > maxlen) {
1306 				if (outlen == 0) {
1307 					error = EMSGSIZE;
1308 					goto bad;
1309 				} else {
1310 					linux_msghdr.msg_flags |= LINUX_MSG_CTRUNC;
1311 					m_dispose_extcontrolm(control);
1312 					goto out;
1313 				}
1314 			}
1315 
1316 			linux_cmsg->cmsg_len = LINUX_CMSG_LEN(datalen);
1317 
1318 			error = copyout(linux_cmsg, outbuf, L_CMSG_HDRSZ);
1319 			if (error != 0)
1320 				goto bad;
1321 			outbuf += L_CMSG_HDRSZ;
1322 
1323 			error = copyout(data, outbuf, datalen);
1324 			if (error != 0)
1325 				goto bad;
1326 
1327 			outbuf += LINUX_CMSG_ALIGN(datalen);
1328 			outlen += LINUX_CMSG_LEN(datalen);
1329 
1330 			cm = CMSG_NXTHDR(msg, cm);
1331 		}
1332 		linux_msghdr.msg_controllen = outlen;
1333 	}
1334 
1335 out:
1336 	error = copyout(&linux_msghdr, msghdr, sizeof(linux_msghdr));
1337 
1338 bad:
1339 	if (control != NULL) {
1340 		if (error != 0)
1341 			m_dispose_extcontrolm(control);
1342 		m_freem(control);
1343 	}
1344 	free(iov, M_IOV);
1345 	free(linux_cmsg, M_LINUX);
1346 	free(sa, M_SONAME);
1347 
1348 	return (error);
1349 }
1350 
1351 int
1352 linux_recvmsg(struct thread *td, struct linux_recvmsg_args *args)
1353 {
1354 	struct msghdr bsd_msg;
1355 
1356 	return (linux_recvmsg_common(td, args->s, PTRIN(args->msg),
1357 	    args->flags, &bsd_msg));
1358 }
1359 
1360 int
1361 linux_recvmmsg(struct thread *td, struct linux_recvmmsg_args *args)
1362 {
1363 	struct l_mmsghdr *msg;
1364 	struct msghdr bsd_msg;
1365 	struct l_timespec lts;
1366 	struct timespec ts, tts;
1367 	l_uint retval;
1368 	int error, datagrams;
1369 
1370 	if (args->timeout) {
1371 		error = copyin(args->timeout, &lts, sizeof(struct l_timespec));
1372 		if (error != 0)
1373 			return (error);
1374 		error = linux_to_native_timespec(&ts, &lts);
1375 		if (error != 0)
1376 			return (error);
1377 		getnanotime(&tts);
1378 		timespecadd(&tts, &ts, &tts);
1379 	}
1380 
1381 	msg = PTRIN(args->msg);
1382 	datagrams = 0;
1383 	while (datagrams < args->vlen) {
1384 		error = linux_recvmsg_common(td, args->s, &msg->msg_hdr,
1385 		    args->flags & ~LINUX_MSG_WAITFORONE, &bsd_msg);
1386 		if (error != 0)
1387 			break;
1388 
1389 		retval = td->td_retval[0];
1390 		error = copyout(&retval, &msg->msg_len, sizeof(msg->msg_len));
1391 		if (error != 0)
1392 			break;
1393 		++msg;
1394 		++datagrams;
1395 
1396 		/*
1397 		 * MSG_WAITFORONE turns on MSG_DONTWAIT after one packet.
1398 		 */
1399 		if (args->flags & LINUX_MSG_WAITFORONE)
1400 			args->flags |= LINUX_MSG_DONTWAIT;
1401 
1402 		/*
1403 		 * See BUGS section of recvmmsg(2).
1404 		 */
1405 		if (args->timeout) {
1406 			getnanotime(&ts);
1407 			timespecsub(&ts, &tts, &ts);
1408 			if (!timespecisset(&ts) || ts.tv_sec > 0)
1409 				break;
1410 		}
1411 		/* Out of band data, return right away. */
1412 		if (bsd_msg.msg_flags & MSG_OOB)
1413 			break;
1414 	}
1415 	if (error == 0)
1416 		td->td_retval[0] = datagrams;
1417 	return (error);
1418 }
1419 
1420 int
1421 linux_shutdown(struct thread *td, struct linux_shutdown_args *args)
1422 {
1423 
1424 	return (kern_shutdown(td, args->s, args->how));
1425 }
1426 
1427 int
1428 linux_setsockopt(struct thread *td, struct linux_setsockopt_args *args)
1429 {
1430 	l_timeval linux_tv;
1431 	struct sockaddr *sa;
1432 	struct timeval tv;
1433 	socklen_t len;
1434 	int error, level, name;
1435 
1436 	level = linux_to_bsd_sockopt_level(args->level);
1437 	switch (level) {
1438 	case SOL_SOCKET:
1439 		name = linux_to_bsd_so_sockopt(args->optname);
1440 		switch (name) {
1441 		case SO_RCVTIMEO:
1442 			/* FALLTHROUGH */
1443 		case SO_SNDTIMEO:
1444 			error = copyin(PTRIN(args->optval), &linux_tv,
1445 			    sizeof(linux_tv));
1446 			if (error != 0)
1447 				return (error);
1448 			tv.tv_sec = linux_tv.tv_sec;
1449 			tv.tv_usec = linux_tv.tv_usec;
1450 			return (kern_setsockopt(td, args->s, level,
1451 			    name, &tv, UIO_SYSSPACE, sizeof(tv)));
1452 			/* NOTREACHED */
1453 		default:
1454 			break;
1455 		}
1456 		break;
1457 	case IPPROTO_IP:
1458 		if (args->optname == LINUX_IP_RECVERR &&
1459 		    linux_ignore_ip_recverr) {
1460 			/*
1461 			 * XXX: This is a hack to unbreak DNS resolution
1462 			 *	with glibc 2.30 and above.
1463 			 */
1464 			return (0);
1465 		}
1466 		name = linux_to_bsd_ip_sockopt(args->optname);
1467 		break;
1468 	case IPPROTO_IPV6:
1469 		name = linux_to_bsd_ip6_sockopt(args->optname);
1470 		break;
1471 	case IPPROTO_TCP:
1472 		name = linux_to_bsd_tcp_sockopt(args->optname);
1473 		break;
1474 	default:
1475 		name = -1;
1476 		break;
1477 	}
1478 	if (name == -1) {
1479 		linux_msg(curthread,
1480 		    "unsupported setsockopt level %d optname %d",
1481 		    args->level, args->optname);
1482 		return (ENOPROTOOPT);
1483 	}
1484 
1485 	if (name == IPV6_NEXTHOP) {
1486 		len = args->optlen;
1487 		error = linux_to_bsd_sockaddr(PTRIN(args->optval), &sa, &len);
1488 		if (error != 0)
1489 			return (error);
1490 
1491 		error = kern_setsockopt(td, args->s, level,
1492 		    name, sa, UIO_SYSSPACE, len);
1493 		free(sa, M_SONAME);
1494 	} else {
1495 		error = kern_setsockopt(td, args->s, level,
1496 		    name, PTRIN(args->optval), UIO_USERSPACE, args->optlen);
1497 	}
1498 
1499 	return (error);
1500 }
1501 
1502 int
1503 linux_getsockopt(struct thread *td, struct linux_getsockopt_args *args)
1504 {
1505 	l_timeval linux_tv;
1506 	struct timeval tv;
1507 	socklen_t tv_len, xulen, len;
1508 	struct l_sockaddr *lsa;
1509 	struct sockaddr *sa;
1510 	struct xucred xu;
1511 	struct l_ucred lxu;
1512 	int error, level, name, newval;
1513 
1514 	level = linux_to_bsd_sockopt_level(args->level);
1515 	switch (level) {
1516 	case SOL_SOCKET:
1517 		name = linux_to_bsd_so_sockopt(args->optname);
1518 		switch (name) {
1519 		case SO_RCVTIMEO:
1520 			/* FALLTHROUGH */
1521 		case SO_SNDTIMEO:
1522 			tv_len = sizeof(tv);
1523 			error = kern_getsockopt(td, args->s, level,
1524 			    name, &tv, UIO_SYSSPACE, &tv_len);
1525 			if (error != 0)
1526 				return (error);
1527 			linux_tv.tv_sec = tv.tv_sec;
1528 			linux_tv.tv_usec = tv.tv_usec;
1529 			return (copyout(&linux_tv, PTRIN(args->optval),
1530 			    sizeof(linux_tv)));
1531 			/* NOTREACHED */
1532 		case LOCAL_PEERCRED:
1533 			if (args->optlen < sizeof(lxu))
1534 				return (EINVAL);
1535 			/*
1536 			 * LOCAL_PEERCRED is not served at the SOL_SOCKET level,
1537 			 * but by the Unix socket's level 0.
1538 			 */
1539 			level = 0;
1540 			xulen = sizeof(xu);
1541 			error = kern_getsockopt(td, args->s, level,
1542 			    name, &xu, UIO_SYSSPACE, &xulen);
1543 			if (error != 0)
1544 				return (error);
1545 			lxu.pid = xu.cr_pid;
1546 			lxu.uid = xu.cr_uid;
1547 			lxu.gid = xu.cr_gid;
1548 			return (copyout(&lxu, PTRIN(args->optval), sizeof(lxu)));
1549 			/* NOTREACHED */
1550 		case SO_ERROR:
1551 			len = sizeof(newval);
1552 			error = kern_getsockopt(td, args->s, level,
1553 			    name, &newval, UIO_SYSSPACE, &len);
1554 			if (error != 0)
1555 				return (error);
1556 			newval = -SV_ABI_ERRNO(td->td_proc, newval);
1557 			return (copyout(&newval, PTRIN(args->optval), len));
1558 			/* NOTREACHED */
1559 		default:
1560 			break;
1561 		}
1562 		break;
1563 	case IPPROTO_IP:
1564 		name = linux_to_bsd_ip_sockopt(args->optname);
1565 		break;
1566 	case IPPROTO_IPV6:
1567 		name = linux_to_bsd_ip6_sockopt(args->optname);
1568 		break;
1569 	case IPPROTO_TCP:
1570 		name = linux_to_bsd_tcp_sockopt(args->optname);
1571 		break;
1572 	default:
1573 		name = -1;
1574 		break;
1575 	}
1576 	if (name == -1) {
1577 		linux_msg(curthread,
1578 		    "unsupported getsockopt level %d optname %d",
1579 		    args->level, args->optname);
1580 		return (EINVAL);
1581 	}
1582 
1583 	if (name == IPV6_NEXTHOP) {
1584 		error = copyin(PTRIN(args->optlen), &len, sizeof(len));
1585                 if (error != 0)
1586                         return (error);
1587 		sa = malloc(len, M_SONAME, M_WAITOK);
1588 
1589 		error = kern_getsockopt(td, args->s, level,
1590 		    name, sa, UIO_SYSSPACE, &len);
1591 		if (error != 0)
1592 			goto out;
1593 
1594 		error = bsd_to_linux_sockaddr(sa, &lsa, len);
1595 		if (error == 0)
1596 			error = copyout(lsa, PTRIN(args->optval), len);
1597 		free(lsa, M_SONAME);
1598 		if (error == 0)
1599 			error = copyout(&len, PTRIN(args->optlen),
1600 			    sizeof(len));
1601 out:
1602 		free(sa, M_SONAME);
1603 	} else {
1604 		if (args->optval) {
1605 			error = copyin(PTRIN(args->optlen), &len, sizeof(len));
1606 			if (error != 0)
1607 				return (error);
1608 		}
1609 		error = kern_getsockopt(td, args->s, level,
1610 		    name, PTRIN(args->optval), UIO_USERSPACE, &len);
1611 		if (error == 0)
1612 			error = copyout(&len, PTRIN(args->optlen),
1613 			    sizeof(len));
1614 	}
1615 
1616 	return (error);
1617 }
1618 
1619 static int
1620 linux_sendfile_common(struct thread *td, l_int out, l_int in,
1621     l_loff_t *offset, l_size_t count)
1622 {
1623 	off_t bytes_read;
1624 	int error;
1625 	l_loff_t current_offset;
1626 	struct file *fp;
1627 
1628 	AUDIT_ARG_FD(in);
1629 	error = fget_read(td, in, &cap_pread_rights, &fp);
1630 	if (error != 0)
1631 		return (error);
1632 
1633 	if (offset != NULL) {
1634 		current_offset = *offset;
1635 	} else {
1636 		error = (fp->f_ops->fo_flags & DFLAG_SEEKABLE) != 0 ?
1637 		    fo_seek(fp, 0, SEEK_CUR, td) : ESPIPE;
1638 		if (error != 0)
1639 			goto drop;
1640 		current_offset = td->td_uretoff.tdu_off;
1641 	}
1642 
1643 	bytes_read = 0;
1644 
1645 	/* Linux cannot have 0 count. */
1646 	if (count <= 0 || current_offset < 0) {
1647 		error = EINVAL;
1648 		goto drop;
1649 	}
1650 
1651 	error = fo_sendfile(fp, out, NULL, NULL, current_offset, count,
1652 	    &bytes_read, 0, td);
1653 	if (error != 0)
1654 		goto drop;
1655 	current_offset += bytes_read;
1656 
1657 	if (offset != NULL) {
1658 		*offset = current_offset;
1659 	} else {
1660 		error = fo_seek(fp, current_offset, SEEK_SET, td);
1661 		if (error != 0)
1662 			goto drop;
1663 	}
1664 
1665 	td->td_retval[0] = (ssize_t)bytes_read;
1666 drop:
1667 	fdrop(fp, td);
1668 	return (error);
1669 }
1670 
1671 int
1672 linux_sendfile(struct thread *td, struct linux_sendfile_args *arg)
1673 {
1674 	/*
1675 	 * Differences between FreeBSD and Linux sendfile:
1676 	 * - Linux doesn't send anything when count is 0 (FreeBSD uses 0 to
1677 	 *   mean send the whole file.)  In linux_sendfile given fds are still
1678 	 *   checked for validity when the count is 0.
1679 	 * - Linux can send to any fd whereas FreeBSD only supports sockets.
1680 	 *   The same restriction follows for linux_sendfile.
1681 	 * - Linux doesn't have an equivalent for FreeBSD's flags and sf_hdtr.
1682 	 * - Linux takes an offset pointer and updates it to the read location.
1683 	 *   FreeBSD takes in an offset and a 'bytes read' parameter which is
1684 	 *   only filled if it isn't NULL.  We use this parameter to update the
1685 	 *   offset pointer if it exists.
1686 	 * - Linux sendfile returns bytes read on success while FreeBSD
1687 	 *   returns 0.  We use the 'bytes read' parameter to get this value.
1688 	 */
1689 
1690 	l_loff_t offset64;
1691 	l_long offset;
1692 	int ret;
1693 	int error;
1694 
1695 	if (arg->offset != NULL) {
1696 		error = copyin(arg->offset, &offset, sizeof(offset));
1697 		if (error != 0)
1698 			return (error);
1699 		offset64 = (l_loff_t)offset;
1700 	}
1701 
1702 	ret = linux_sendfile_common(td, arg->out, arg->in,
1703 	    arg->offset != NULL ? &offset64 : NULL, arg->count);
1704 
1705 	if (arg->offset != NULL) {
1706 #if defined(__i386__) || defined(__arm__) || \
1707     (defined(__amd64__) && defined(COMPAT_LINUX32))
1708 		if (offset64 > INT32_MAX)
1709 			return (EOVERFLOW);
1710 #endif
1711 		offset = (l_long)offset64;
1712 		error = copyout(&offset, arg->offset, sizeof(offset));
1713 		if (error != 0)
1714 			return (error);
1715 	}
1716 
1717 	return (ret);
1718 }
1719 
1720 #if defined(__i386__) || defined(__arm__) || \
1721     (defined(__amd64__) && defined(COMPAT_LINUX32))
1722 
1723 int
1724 linux_sendfile64(struct thread *td, struct linux_sendfile64_args *arg)
1725 {
1726 	l_loff_t offset;
1727 	int ret;
1728 	int error;
1729 
1730 	if (arg->offset != NULL) {
1731 		error = copyin(arg->offset, &offset, sizeof(offset));
1732 		if (error != 0)
1733 			return (error);
1734 	}
1735 
1736 	ret = linux_sendfile_common(td, arg->out, arg->in,
1737 		arg->offset != NULL ? &offset : NULL, arg->count);
1738 
1739 	if (arg->offset != NULL) {
1740 		error = copyout(&offset, arg->offset, sizeof(offset));
1741 		if (error != 0)
1742 			return (error);
1743 	}
1744 
1745 	return (ret);
1746 }
1747 
1748 /* Argument list sizes for linux_socketcall */
1749 static const unsigned char lxs_args_cnt[] = {
1750 	0 /* unused*/,		3 /* socket */,
1751 	3 /* bind */,		3 /* connect */,
1752 	2 /* listen */,		3 /* accept */,
1753 	3 /* getsockname */,	3 /* getpeername */,
1754 	4 /* socketpair */,	4 /* send */,
1755 	4 /* recv */,		6 /* sendto */,
1756 	6 /* recvfrom */,	2 /* shutdown */,
1757 	5 /* setsockopt */,	5 /* getsockopt */,
1758 	3 /* sendmsg */,	3 /* recvmsg */,
1759 	4 /* accept4 */,	5 /* recvmmsg */,
1760 	4 /* sendmmsg */,	4 /* sendfile */
1761 };
1762 #define	LINUX_ARGS_CNT		(nitems(lxs_args_cnt) - 1)
1763 #define	LINUX_ARG_SIZE(x)	(lxs_args_cnt[x] * sizeof(l_ulong))
1764 
1765 int
1766 linux_socketcall(struct thread *td, struct linux_socketcall_args *args)
1767 {
1768 	l_ulong a[6];
1769 #if defined(__amd64__) && defined(COMPAT_LINUX32)
1770 	register_t l_args[6];
1771 #endif
1772 	void *arg;
1773 	int error;
1774 
1775 	if (args->what < LINUX_SOCKET || args->what > LINUX_ARGS_CNT)
1776 		return (EINVAL);
1777 	error = copyin(PTRIN(args->args), a, LINUX_ARG_SIZE(args->what));
1778 	if (error != 0)
1779 		return (error);
1780 
1781 #if defined(__amd64__) && defined(COMPAT_LINUX32)
1782 	for (int i = 0; i < lxs_args_cnt[args->what]; ++i)
1783 		l_args[i] = a[i];
1784 	arg = l_args;
1785 #else
1786 	arg = a;
1787 #endif
1788 	switch (args->what) {
1789 	case LINUX_SOCKET:
1790 		return (linux_socket(td, arg));
1791 	case LINUX_BIND:
1792 		return (linux_bind(td, arg));
1793 	case LINUX_CONNECT:
1794 		return (linux_connect(td, arg));
1795 	case LINUX_LISTEN:
1796 		return (linux_listen(td, arg));
1797 	case LINUX_ACCEPT:
1798 		return (linux_accept(td, arg));
1799 	case LINUX_GETSOCKNAME:
1800 		return (linux_getsockname(td, arg));
1801 	case LINUX_GETPEERNAME:
1802 		return (linux_getpeername(td, arg));
1803 	case LINUX_SOCKETPAIR:
1804 		return (linux_socketpair(td, arg));
1805 	case LINUX_SEND:
1806 		return (linux_send(td, arg));
1807 	case LINUX_RECV:
1808 		return (linux_recv(td, arg));
1809 	case LINUX_SENDTO:
1810 		return (linux_sendto(td, arg));
1811 	case LINUX_RECVFROM:
1812 		return (linux_recvfrom(td, arg));
1813 	case LINUX_SHUTDOWN:
1814 		return (linux_shutdown(td, arg));
1815 	case LINUX_SETSOCKOPT:
1816 		return (linux_setsockopt(td, arg));
1817 	case LINUX_GETSOCKOPT:
1818 		return (linux_getsockopt(td, arg));
1819 	case LINUX_SENDMSG:
1820 		return (linux_sendmsg(td, arg));
1821 	case LINUX_RECVMSG:
1822 		return (linux_recvmsg(td, arg));
1823 	case LINUX_ACCEPT4:
1824 		return (linux_accept4(td, arg));
1825 	case LINUX_RECVMMSG:
1826 		return (linux_recvmmsg(td, arg));
1827 	case LINUX_SENDMMSG:
1828 		return (linux_sendmmsg(td, arg));
1829 	case LINUX_SENDFILE:
1830 		return (linux_sendfile(td, arg));
1831 	}
1832 
1833 	linux_msg(td, "socket type %d not implemented", args->what);
1834 	return (ENOSYS);
1835 }
1836 #endif /* __i386__ || __arm__ || (__amd64__ && COMPAT_LINUX32) */
1837