xref: /freebsd/sys/compat/linux/linux_socket.c (revision 100353cfbf882e23c911300ebd0cb458bd3ee975)
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_copyout_sockaddr(const struct sockaddr *sa, void *uaddr, size_t len)
398 {
399 	struct l_sockaddr *lsa;
400 	int error;
401 
402 	error = bsd_to_linux_sockaddr(sa, &lsa, len);
403 	if (error != 0)
404 		return (error);
405 
406 	error = copyout(lsa, uaddr, len);
407 	free(lsa, M_SONAME);
408 
409 	return (error);
410 }
411 
412 static int
413 linux_sendit(struct thread *td, int s, struct msghdr *mp, int flags,
414     struct mbuf *control, enum uio_seg segflg)
415 {
416 	struct sockaddr *to;
417 	int error, len;
418 
419 	if (mp->msg_name != NULL) {
420 		len = mp->msg_namelen;
421 		error = linux_to_bsd_sockaddr(mp->msg_name, &to, &len);
422 		if (error != 0)
423 			return (error);
424 		mp->msg_name = to;
425 	} else
426 		to = NULL;
427 
428 	error = kern_sendit(td, s, mp, linux_to_bsd_msg_flags(flags), control,
429 	    segflg);
430 
431 	if (to)
432 		free(to, M_SONAME);
433 	return (error);
434 }
435 
436 /* Return 0 if IP_HDRINCL is set for the given socket. */
437 static int
438 linux_check_hdrincl(struct thread *td, int s)
439 {
440 	int error, optval;
441 	socklen_t size_val;
442 
443 	size_val = sizeof(optval);
444 	error = kern_getsockopt(td, s, IPPROTO_IP, IP_HDRINCL,
445 	    &optval, UIO_SYSSPACE, &size_val);
446 	if (error != 0)
447 		return (error);
448 
449 	return (optval == 0);
450 }
451 
452 /*
453  * Updated sendto() when IP_HDRINCL is set:
454  * tweak endian-dependent fields in the IP packet.
455  */
456 static int
457 linux_sendto_hdrincl(struct thread *td, struct linux_sendto_args *linux_args)
458 {
459 /*
460  * linux_ip_copysize defines how many bytes we should copy
461  * from the beginning of the IP packet before we customize it for BSD.
462  * It should include all the fields we modify (ip_len and ip_off).
463  */
464 #define linux_ip_copysize	8
465 
466 	struct ip *packet;
467 	struct msghdr msg;
468 	struct iovec aiov[1];
469 	int error;
470 
471 	/* Check that the packet isn't too big or too small. */
472 	if (linux_args->len < linux_ip_copysize ||
473 	    linux_args->len > IP_MAXPACKET)
474 		return (EINVAL);
475 
476 	packet = (struct ip *)malloc(linux_args->len, M_LINUX, M_WAITOK);
477 
478 	/* Make kernel copy of the packet to be sent */
479 	if ((error = copyin(PTRIN(linux_args->msg), packet,
480 	    linux_args->len)))
481 		goto goout;
482 
483 	/* Convert fields from Linux to BSD raw IP socket format */
484 	packet->ip_len = linux_args->len;
485 	packet->ip_off = ntohs(packet->ip_off);
486 
487 	/* Prepare the msghdr and iovec structures describing the new packet */
488 	msg.msg_name = PTRIN(linux_args->to);
489 	msg.msg_namelen = linux_args->tolen;
490 	msg.msg_iov = aiov;
491 	msg.msg_iovlen = 1;
492 	msg.msg_control = NULL;
493 	msg.msg_flags = 0;
494 	aiov[0].iov_base = (char *)packet;
495 	aiov[0].iov_len = linux_args->len;
496 	error = linux_sendit(td, linux_args->s, &msg, linux_args->flags,
497 	    NULL, UIO_SYSSPACE);
498 goout:
499 	free(packet, M_LINUX);
500 	return (error);
501 }
502 
503 int
504 linux_socket(struct thread *td, struct linux_socket_args *args)
505 {
506 	int domain, retval_socket, type;
507 
508 	type = args->type & LINUX_SOCK_TYPE_MASK;
509 	if (type < 0 || type > LINUX_SOCK_MAX)
510 		return (EINVAL);
511 	retval_socket = linux_set_socket_flags(args->type & ~LINUX_SOCK_TYPE_MASK,
512 		&type);
513 	if (retval_socket != 0)
514 		return (retval_socket);
515 	domain = linux_to_bsd_domain(args->domain);
516 	if (domain == -1)
517 		return (EAFNOSUPPORT);
518 
519 	retval_socket = kern_socket(td, domain, type, args->protocol);
520 	if (retval_socket)
521 		return (retval_socket);
522 
523 	if (type == SOCK_RAW
524 	    && (args->protocol == IPPROTO_RAW || args->protocol == 0)
525 	    && domain == PF_INET) {
526 		/* It's a raw IP socket: set the IP_HDRINCL option. */
527 		int hdrincl;
528 
529 		hdrincl = 1;
530 		/* We ignore any error returned by kern_setsockopt() */
531 		kern_setsockopt(td, td->td_retval[0], IPPROTO_IP, IP_HDRINCL,
532 		    &hdrincl, UIO_SYSSPACE, sizeof(hdrincl));
533 	}
534 #ifdef INET6
535 	/*
536 	 * Linux AF_INET6 socket has IPV6_V6ONLY setsockopt set to 0 by default
537 	 * and some apps depend on this. So, set V6ONLY to 0 for Linux apps.
538 	 * For simplicity we do this unconditionally of the net.inet6.ip6.v6only
539 	 * sysctl value.
540 	 */
541 	if (domain == PF_INET6) {
542 		int v6only;
543 
544 		v6only = 0;
545 		/* We ignore any error returned by setsockopt() */
546 		kern_setsockopt(td, td->td_retval[0], IPPROTO_IPV6, IPV6_V6ONLY,
547 		    &v6only, UIO_SYSSPACE, sizeof(v6only));
548 	}
549 #endif
550 
551 	return (retval_socket);
552 }
553 
554 int
555 linux_bind(struct thread *td, struct linux_bind_args *args)
556 {
557 	struct sockaddr *sa;
558 	int error;
559 
560 	error = linux_to_bsd_sockaddr(PTRIN(args->name), &sa,
561 	    &args->namelen);
562 	if (error != 0)
563 		return (error);
564 
565 	error = kern_bindat(td, AT_FDCWD, args->s, sa);
566 	free(sa, M_SONAME);
567 
568 	/* XXX */
569 	if (error == EADDRNOTAVAIL && args->namelen != sizeof(struct sockaddr_in))
570 		return (EINVAL);
571 	return (error);
572 }
573 
574 int
575 linux_connect(struct thread *td, struct linux_connect_args *args)
576 {
577 	struct socket *so;
578 	struct sockaddr *sa;
579 	struct file *fp;
580 	u_int fflag;
581 	int error;
582 
583 	error = linux_to_bsd_sockaddr(PTRIN(args->name), &sa,
584 	    &args->namelen);
585 	if (error != 0)
586 		return (error);
587 
588 	error = kern_connectat(td, AT_FDCWD, args->s, sa);
589 	free(sa, M_SONAME);
590 	if (error != EISCONN)
591 		return (error);
592 
593 	/*
594 	 * Linux doesn't return EISCONN the first time it occurs,
595 	 * when on a non-blocking socket. Instead it returns the
596 	 * error getsockopt(SOL_SOCKET, SO_ERROR) would return on BSD.
597 	 */
598 	error = getsock_cap(td, args->s, &cap_connect_rights,
599 	    &fp, &fflag, NULL);
600 	if (error != 0)
601 		return (error);
602 
603 	error = EISCONN;
604 	so = fp->f_data;
605 	if (fflag & FNONBLOCK) {
606 		SOCK_LOCK(so);
607 		if (so->so_emuldata == 0)
608 			error = so->so_error;
609 		so->so_emuldata = (void *)1;
610 		SOCK_UNLOCK(so);
611 	}
612 	fdrop(fp, td);
613 
614 	return (error);
615 }
616 
617 int
618 linux_listen(struct thread *td, struct linux_listen_args *args)
619 {
620 
621 	return (kern_listen(td, args->s, args->backlog));
622 }
623 
624 static int
625 linux_accept_common(struct thread *td, int s, l_uintptr_t addr,
626     l_uintptr_t namelen, int flags)
627 {
628 	struct sockaddr *sa;
629 	struct file *fp, *fp1;
630 	int bflags, len;
631 	struct socket *so;
632 	int error, error1;
633 
634 	bflags = 0;
635 	fp = NULL;
636 	sa = NULL;
637 
638 	error = linux_set_socket_flags(flags, &bflags);
639 	if (error != 0)
640 		return (error);
641 
642 	if (PTRIN(addr) == NULL) {
643 		len = 0;
644 		error = kern_accept4(td, s, NULL, NULL, bflags, NULL);
645 	} else {
646 		error = copyin(PTRIN(namelen), &len, sizeof(len));
647 		if (error != 0)
648 			return (error);
649 		if (len < 0)
650 			return (EINVAL);
651 		error = kern_accept4(td, s, &sa, &len, bflags, &fp);
652 	}
653 
654 	/*
655 	 * Translate errno values into ones used by Linux.
656 	 */
657 	if (error != 0) {
658 		/*
659 		 * XXX. This is wrong, different sockaddr structures
660 		 * have different sizes.
661 		 */
662 		switch (error) {
663 		case EFAULT:
664 			if (namelen != sizeof(struct sockaddr_in))
665 				error = EINVAL;
666 			break;
667 		case EINVAL:
668 			error1 = getsock_cap(td, s, &cap_accept_rights, &fp1, NULL, NULL);
669 			if (error1 != 0) {
670 				error = error1;
671 				break;
672 			}
673 			so = fp1->f_data;
674 			if (so->so_type == SOCK_DGRAM)
675 				error = EOPNOTSUPP;
676 			fdrop(fp1, td);
677 			break;
678 		}
679 		return (error);
680 	}
681 
682 	if (len != 0) {
683 		error = linux_copyout_sockaddr(sa, PTRIN(addr), len);
684 
685 		/*
686 		 * XXX: We should also copyout the len, shouldn't we?
687 		 */
688 
689 		if (error != 0) {
690 			fdclose(td, fp, td->td_retval[0]);
691 			td->td_retval[0] = 0;
692 		}
693 	}
694 	if (fp != NULL)
695 		fdrop(fp, td);
696 	free(sa, M_SONAME);
697 	return (error);
698 }
699 
700 int
701 linux_accept(struct thread *td, struct linux_accept_args *args)
702 {
703 
704 	return (linux_accept_common(td, args->s, args->addr,
705 	    args->namelen, 0));
706 }
707 
708 int
709 linux_accept4(struct thread *td, struct linux_accept4_args *args)
710 {
711 
712 	return (linux_accept_common(td, args->s, args->addr,
713 	    args->namelen, args->flags));
714 }
715 
716 int
717 linux_getsockname(struct thread *td, struct linux_getsockname_args *args)
718 {
719 	struct sockaddr *sa;
720 	int len, error;
721 
722 	error = copyin(PTRIN(args->namelen), &len, sizeof(len));
723 	if (error != 0)
724 		return (error);
725 
726 	error = kern_getsockname(td, args->s, &sa, &len);
727 	if (error != 0)
728 		return (error);
729 
730 	if (len != 0)
731 		error = linux_copyout_sockaddr(sa, PTRIN(args->addr), len);
732 
733 	free(sa, M_SONAME);
734 	if (error == 0)
735 		error = copyout(&len, PTRIN(args->namelen), sizeof(len));
736 	return (error);
737 }
738 
739 int
740 linux_getpeername(struct thread *td, struct linux_getpeername_args *args)
741 {
742 	struct sockaddr *sa;
743 	int len, error;
744 
745 	error = copyin(PTRIN(args->namelen), &len, sizeof(len));
746 	if (error != 0)
747 		return (error);
748 	if (len < 0)
749 		return (EINVAL);
750 
751 	error = kern_getpeername(td, args->s, &sa, &len);
752 	if (error != 0)
753 		return (error);
754 
755 	if (len != 0)
756 		error = linux_copyout_sockaddr(sa, PTRIN(args->addr), len);
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 sockaddr *sa;
899 	struct msghdr msg;
900 	struct iovec aiov;
901 	int error, fromlen;
902 
903 	if (PTRIN(args->fromlen) != NULL) {
904 		error = copyin(PTRIN(args->fromlen), &fromlen,
905 		    sizeof(fromlen));
906 		if (error != 0)
907 			return (error);
908 		if (fromlen < 0)
909 			return (EINVAL);
910 		sa = malloc(fromlen, M_SONAME, M_WAITOK);
911 	} else {
912 		fromlen = 0;
913 		sa = NULL;
914 	}
915 
916 	msg.msg_name = sa;
917 	msg.msg_namelen = fromlen;
918 	msg.msg_iov = &aiov;
919 	msg.msg_iovlen = 1;
920 	aiov.iov_base = PTRIN(args->buf);
921 	aiov.iov_len = args->len;
922 	msg.msg_control = 0;
923 	msg.msg_flags = linux_to_bsd_msg_flags(args->flags);
924 
925 	error = kern_recvit(td, args->s, &msg, UIO_SYSSPACE, NULL);
926 	if (error != 0)
927 		goto out;
928 
929 	if (PTRIN(args->from) != NULL)
930 		error = linux_copyout_sockaddr(sa, PTRIN(args->from), msg.msg_namelen);
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_msghdr;
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_msghdr, sizeof(linux_msghdr));
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_msghdr.msg_control) != NULL &&
973 	    linux_msghdr.msg_controllen == 0)
974 		linux_msghdr.msg_control = PTROUT(NULL);
975 
976 	error = linux_to_bsd_msghdr(&msg, &linux_msghdr);
977 	if (error != 0)
978 		return (error);
979 
980 #ifdef COMPAT_LINUX32
981 	error = linux32_copyiniov(PTRIN(msg.msg_iov), msg.msg_iovlen,
982 	    &iov, EMSGSIZE);
983 #else
984 	error = copyiniov(msg.msg_iov, msg.msg_iovlen, &iov, EMSGSIZE);
985 #endif
986 	if (error != 0)
987 		return (error);
988 
989 	control = NULL;
990 
991 	error = kern_getsockname(td, s, &sa, &datalen);
992 	if (error != 0)
993 		goto bad;
994 	sa_family = sa->sa_family;
995 	free(sa, M_SONAME);
996 
997 	if (flags & LINUX_MSG_OOB) {
998 		error = EOPNOTSUPP;
999 		if (sa_family == AF_UNIX)
1000 			goto bad;
1001 
1002 		error = getsock_cap(td, s, &cap_send_rights, &fp,
1003 		    &fflag, NULL);
1004 		if (error != 0)
1005 			goto bad;
1006 		so = fp->f_data;
1007 		if (so->so_type != SOCK_STREAM)
1008 			error = EOPNOTSUPP;
1009 		fdrop(fp, td);
1010 		if (error != 0)
1011 			goto bad;
1012 	}
1013 
1014 	if (linux_msghdr.msg_controllen >= sizeof(struct l_cmsghdr)) {
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_msghdr.msg_control);
1022 		clen = linux_msghdr.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 				linux_msg(curthread,
1049 				    "unsupported sendmsg cmsg level %d type %d",
1050 				    linux_cmsg.cmsg_level, linux_cmsg.cmsg_type);
1051 				goto bad;
1052 			}
1053 
1054 			/*
1055 			 * Some applications (e.g. pulseaudio) attempt to
1056 			 * send ancillary data even if the underlying protocol
1057 			 * doesn't support it which is not allowed in the
1058 			 * FreeBSD system call interface.
1059 			 */
1060 			if (sa_family != AF_UNIX)
1061 				goto next;
1062 
1063 			if (cmsg->cmsg_type == SCM_CREDS) {
1064 				len = sizeof(struct cmsgcred);
1065 				if (datalen + CMSG_SPACE(len) > MCLBYTES)
1066 					goto bad;
1067 
1068 				/*
1069 				 * The lower levels will fill in the structure
1070 				 */
1071 				memset(CMSG_DATA(data), 0, len);
1072 			} else {
1073 				len = linux_cmsg.cmsg_len - L_CMSG_HDRSZ;
1074 				if (datalen + CMSG_SPACE(len) < datalen ||
1075 				    datalen + CMSG_SPACE(len) > MCLBYTES)
1076 					goto bad;
1077 
1078 				error = copyin(LINUX_CMSG_DATA(ptr_cmsg),
1079 				    CMSG_DATA(data), len);
1080 				if (error != 0)
1081 					goto bad;
1082 			}
1083 
1084 			cmsg->cmsg_len = CMSG_LEN(len);
1085 			data = (char *)data + CMSG_SPACE(len);
1086 			datalen += CMSG_SPACE(len);
1087 
1088 next:
1089 			if (clen <= LINUX_CMSG_ALIGN(linux_cmsg.cmsg_len))
1090 				break;
1091 
1092 			clen -= LINUX_CMSG_ALIGN(linux_cmsg.cmsg_len);
1093 			ptr_cmsg = (struct l_cmsghdr *)((char *)ptr_cmsg +
1094 			    LINUX_CMSG_ALIGN(linux_cmsg.cmsg_len));
1095 		} while(clen >= sizeof(struct l_cmsghdr));
1096 
1097 		control->m_len = datalen;
1098 		if (datalen == 0) {
1099 			m_freem(control);
1100 			control = NULL;
1101 		}
1102 	}
1103 
1104 	msg.msg_iov = iov;
1105 	msg.msg_flags = 0;
1106 	error = linux_sendit(td, s, &msg, flags, control, UIO_USERSPACE);
1107 	control = NULL;
1108 
1109 bad:
1110 	m_freem(control);
1111 	free(iov, M_IOV);
1112 	return (error);
1113 }
1114 
1115 int
1116 linux_sendmsg(struct thread *td, struct linux_sendmsg_args *args)
1117 {
1118 
1119 	return (linux_sendmsg_common(td, args->s, PTRIN(args->msg),
1120 	    args->flags));
1121 }
1122 
1123 int
1124 linux_sendmmsg(struct thread *td, struct linux_sendmmsg_args *args)
1125 {
1126 	struct l_mmsghdr *msg;
1127 	l_uint retval;
1128 	int error, datagrams;
1129 
1130 	if (args->vlen > UIO_MAXIOV)
1131 		args->vlen = UIO_MAXIOV;
1132 
1133 	msg = PTRIN(args->msg);
1134 	datagrams = 0;
1135 	while (datagrams < args->vlen) {
1136 		error = linux_sendmsg_common(td, args->s, &msg->msg_hdr,
1137 		    args->flags);
1138 		if (error != 0)
1139 			break;
1140 
1141 		retval = td->td_retval[0];
1142 		error = copyout(&retval, &msg->msg_len, sizeof(msg->msg_len));
1143 		if (error != 0)
1144 			break;
1145 		++msg;
1146 		++datagrams;
1147 	}
1148 	if (error == 0)
1149 		td->td_retval[0] = datagrams;
1150 	return (error);
1151 }
1152 
1153 static int
1154 linux_recvmsg_common(struct thread *td, l_int s, struct l_msghdr *msghdr,
1155     l_uint flags, struct msghdr *msg)
1156 {
1157 	struct cmsghdr *cm;
1158 	struct cmsgcred *cmcred;
1159 	struct l_cmsghdr *linux_cmsg = NULL;
1160 	struct l_ucred linux_ucred;
1161 	socklen_t datalen, maxlen, outlen;
1162 	struct l_msghdr linux_msghdr;
1163 	struct iovec *iov, *uiov;
1164 	struct mbuf *control = NULL;
1165 	struct mbuf **controlp;
1166 	struct timeval *ftmvl;
1167 	struct sockaddr *sa;
1168 	l_timeval ltmvl;
1169 	caddr_t outbuf;
1170 	void *data;
1171 	int error, i, fd, fds, *fdp;
1172 
1173 	error = copyin(msghdr, &linux_msghdr, sizeof(linux_msghdr));
1174 	if (error != 0)
1175 		return (error);
1176 
1177 	error = linux_to_bsd_msghdr(msg, &linux_msghdr);
1178 	if (error != 0)
1179 		return (error);
1180 
1181 #ifdef COMPAT_LINUX32
1182 	error = linux32_copyiniov(PTRIN(msg->msg_iov), msg->msg_iovlen,
1183 	    &iov, EMSGSIZE);
1184 #else
1185 	error = copyiniov(msg->msg_iov, msg->msg_iovlen, &iov, EMSGSIZE);
1186 #endif
1187 	if (error != 0)
1188 		return (error);
1189 
1190 	if (msg->msg_name != NULL && msg->msg_namelen > 0) {
1191 		msg->msg_namelen = min(msg->msg_namelen, SOCK_MAXADDRLEN);
1192 		sa = malloc(msg->msg_namelen, M_SONAME, M_WAITOK);
1193 		msg->msg_name = sa;
1194 	} else {
1195 		sa = NULL;
1196 		msg->msg_name = NULL;
1197 	}
1198 
1199 	uiov = msg->msg_iov;
1200 	msg->msg_iov = iov;
1201 	controlp = (msg->msg_control != NULL) ? &control : NULL;
1202 	error = kern_recvit(td, s, msg, UIO_SYSSPACE, controlp);
1203 	msg->msg_iov = uiov;
1204 	if (error != 0)
1205 		goto bad;
1206 
1207 	/*
1208 	 * Note that kern_recvit() updates msg->msg_namelen.
1209 	 */
1210 	if (msg->msg_name != NULL && msg->msg_namelen > 0) {
1211 		msg->msg_name = PTRIN(linux_msghdr.msg_name);
1212 		error = linux_copyout_sockaddr(sa,
1213 		    PTRIN(msg->msg_name), msg->msg_namelen);
1214 		if (error != 0)
1215 			goto bad;
1216 	}
1217 
1218 	error = bsd_to_linux_msghdr(msg, &linux_msghdr);
1219 	if (error != 0)
1220 		goto bad;
1221 
1222 	maxlen = linux_msghdr.msg_controllen;
1223 	linux_msghdr.msg_controllen = 0;
1224 	if (control) {
1225 		linux_cmsg = malloc(L_CMSG_HDRSZ, M_LINUX, M_WAITOK | M_ZERO);
1226 
1227 		msg->msg_control = mtod(control, struct cmsghdr *);
1228 		msg->msg_controllen = control->m_len;
1229 
1230 		cm = CMSG_FIRSTHDR(msg);
1231 		outbuf = PTRIN(linux_msghdr.msg_control);
1232 		outlen = 0;
1233 		while (cm != NULL) {
1234 			linux_cmsg->cmsg_type =
1235 			    bsd_to_linux_cmsg_type(cm->cmsg_type);
1236 			linux_cmsg->cmsg_level =
1237 			    bsd_to_linux_sockopt_level(cm->cmsg_level);
1238 			if (linux_cmsg->cmsg_type == -1 ||
1239 			    cm->cmsg_level != SOL_SOCKET) {
1240 				linux_msg(curthread,
1241 				    "unsupported recvmsg cmsg level %d type %d",
1242 				    cm->cmsg_level, cm->cmsg_type);
1243 				error = EINVAL;
1244 				goto bad;
1245 			}
1246 
1247 			data = CMSG_DATA(cm);
1248 			datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1249 
1250 			switch (cm->cmsg_type) {
1251 			case SCM_RIGHTS:
1252 				if (flags & LINUX_MSG_CMSG_CLOEXEC) {
1253 					fds = datalen / sizeof(int);
1254 					fdp = data;
1255 					for (i = 0; i < fds; i++) {
1256 						fd = *fdp++;
1257 						(void)kern_fcntl(td, fd,
1258 						    F_SETFD, FD_CLOEXEC);
1259 					}
1260 				}
1261 				break;
1262 
1263 			case SCM_CREDS:
1264 				/*
1265 				 * Currently LOCAL_CREDS is never in
1266 				 * effect for Linux so no need to worry
1267 				 * about sockcred
1268 				 */
1269 				if (datalen != sizeof(*cmcred)) {
1270 					error = EMSGSIZE;
1271 					goto bad;
1272 				}
1273 				cmcred = (struct cmsgcred *)data;
1274 				bzero(&linux_ucred, sizeof(linux_ucred));
1275 				linux_ucred.pid = cmcred->cmcred_pid;
1276 				linux_ucred.uid = cmcred->cmcred_uid;
1277 				linux_ucred.gid = cmcred->cmcred_gid;
1278 				data = &linux_ucred;
1279 				datalen = sizeof(linux_ucred);
1280 				break;
1281 
1282 			case SCM_TIMESTAMP:
1283 				if (datalen != sizeof(struct timeval)) {
1284 					error = EMSGSIZE;
1285 					goto bad;
1286 				}
1287 				ftmvl = (struct timeval *)data;
1288 				ltmvl.tv_sec = ftmvl->tv_sec;
1289 				ltmvl.tv_usec = ftmvl->tv_usec;
1290 				data = &ltmvl;
1291 				datalen = sizeof(ltmvl);
1292 				break;
1293 			}
1294 
1295 			if (outlen + LINUX_CMSG_LEN(datalen) > maxlen) {
1296 				if (outlen == 0) {
1297 					error = EMSGSIZE;
1298 					goto bad;
1299 				} else {
1300 					linux_msghdr.msg_flags |= LINUX_MSG_CTRUNC;
1301 					m_dispose_extcontrolm(control);
1302 					goto out;
1303 				}
1304 			}
1305 
1306 			linux_cmsg->cmsg_len = LINUX_CMSG_LEN(datalen);
1307 
1308 			error = copyout(linux_cmsg, outbuf, L_CMSG_HDRSZ);
1309 			if (error != 0)
1310 				goto bad;
1311 			outbuf += L_CMSG_HDRSZ;
1312 
1313 			error = copyout(data, outbuf, datalen);
1314 			if (error != 0)
1315 				goto bad;
1316 
1317 			outbuf += LINUX_CMSG_ALIGN(datalen);
1318 			outlen += LINUX_CMSG_LEN(datalen);
1319 
1320 			cm = CMSG_NXTHDR(msg, cm);
1321 		}
1322 		linux_msghdr.msg_controllen = outlen;
1323 	}
1324 
1325 out:
1326 	error = copyout(&linux_msghdr, msghdr, sizeof(linux_msghdr));
1327 
1328 bad:
1329 	if (control != NULL) {
1330 		if (error != 0)
1331 			m_dispose_extcontrolm(control);
1332 		m_freem(control);
1333 	}
1334 	free(iov, M_IOV);
1335 	free(linux_cmsg, M_LINUX);
1336 	free(sa, M_SONAME);
1337 
1338 	return (error);
1339 }
1340 
1341 int
1342 linux_recvmsg(struct thread *td, struct linux_recvmsg_args *args)
1343 {
1344 	struct msghdr bsd_msg;
1345 
1346 	return (linux_recvmsg_common(td, args->s, PTRIN(args->msg),
1347 	    args->flags, &bsd_msg));
1348 }
1349 
1350 int
1351 linux_recvmmsg(struct thread *td, struct linux_recvmmsg_args *args)
1352 {
1353 	struct l_mmsghdr *msg;
1354 	struct msghdr bsd_msg;
1355 	struct l_timespec lts;
1356 	struct timespec ts, tts;
1357 	l_uint retval;
1358 	int error, datagrams;
1359 
1360 	if (args->timeout) {
1361 		error = copyin(args->timeout, &lts, sizeof(struct l_timespec));
1362 		if (error != 0)
1363 			return (error);
1364 		error = linux_to_native_timespec(&ts, &lts);
1365 		if (error != 0)
1366 			return (error);
1367 		getnanotime(&tts);
1368 		timespecadd(&tts, &ts, &tts);
1369 	}
1370 
1371 	msg = PTRIN(args->msg);
1372 	datagrams = 0;
1373 	while (datagrams < args->vlen) {
1374 		error = linux_recvmsg_common(td, args->s, &msg->msg_hdr,
1375 		    args->flags & ~LINUX_MSG_WAITFORONE, &bsd_msg);
1376 		if (error != 0)
1377 			break;
1378 
1379 		retval = td->td_retval[0];
1380 		error = copyout(&retval, &msg->msg_len, sizeof(msg->msg_len));
1381 		if (error != 0)
1382 			break;
1383 		++msg;
1384 		++datagrams;
1385 
1386 		/*
1387 		 * MSG_WAITFORONE turns on MSG_DONTWAIT after one packet.
1388 		 */
1389 		if (args->flags & LINUX_MSG_WAITFORONE)
1390 			args->flags |= LINUX_MSG_DONTWAIT;
1391 
1392 		/*
1393 		 * See BUGS section of recvmmsg(2).
1394 		 */
1395 		if (args->timeout) {
1396 			getnanotime(&ts);
1397 			timespecsub(&ts, &tts, &ts);
1398 			if (!timespecisset(&ts) || ts.tv_sec > 0)
1399 				break;
1400 		}
1401 		/* Out of band data, return right away. */
1402 		if (bsd_msg.msg_flags & MSG_OOB)
1403 			break;
1404 	}
1405 	if (error == 0)
1406 		td->td_retval[0] = datagrams;
1407 	return (error);
1408 }
1409 
1410 int
1411 linux_shutdown(struct thread *td, struct linux_shutdown_args *args)
1412 {
1413 
1414 	return (kern_shutdown(td, args->s, args->how));
1415 }
1416 
1417 int
1418 linux_setsockopt(struct thread *td, struct linux_setsockopt_args *args)
1419 {
1420 	l_timeval linux_tv;
1421 	struct sockaddr *sa;
1422 	struct timeval tv;
1423 	socklen_t len;
1424 	int error, level, name;
1425 
1426 	level = linux_to_bsd_sockopt_level(args->level);
1427 	switch (level) {
1428 	case SOL_SOCKET:
1429 		name = linux_to_bsd_so_sockopt(args->optname);
1430 		switch (name) {
1431 		case SO_RCVTIMEO:
1432 			/* FALLTHROUGH */
1433 		case SO_SNDTIMEO:
1434 			error = copyin(PTRIN(args->optval), &linux_tv,
1435 			    sizeof(linux_tv));
1436 			if (error != 0)
1437 				return (error);
1438 			tv.tv_sec = linux_tv.tv_sec;
1439 			tv.tv_usec = linux_tv.tv_usec;
1440 			return (kern_setsockopt(td, args->s, level,
1441 			    name, &tv, UIO_SYSSPACE, sizeof(tv)));
1442 			/* NOTREACHED */
1443 		default:
1444 			break;
1445 		}
1446 		break;
1447 	case IPPROTO_IP:
1448 		if (args->optname == LINUX_IP_RECVERR &&
1449 		    linux_ignore_ip_recverr) {
1450 			/*
1451 			 * XXX: This is a hack to unbreak DNS resolution
1452 			 *	with glibc 2.30 and above.
1453 			 */
1454 			return (0);
1455 		}
1456 		name = linux_to_bsd_ip_sockopt(args->optname);
1457 		break;
1458 	case IPPROTO_IPV6:
1459 		name = linux_to_bsd_ip6_sockopt(args->optname);
1460 		break;
1461 	case IPPROTO_TCP:
1462 		name = linux_to_bsd_tcp_sockopt(args->optname);
1463 		break;
1464 	default:
1465 		name = -1;
1466 		break;
1467 	}
1468 	if (name == -1) {
1469 		linux_msg(curthread,
1470 		    "unsupported setsockopt level %d optname %d",
1471 		    args->level, args->optname);
1472 		return (ENOPROTOOPT);
1473 	}
1474 
1475 	if (name == IPV6_NEXTHOP) {
1476 		len = args->optlen;
1477 		error = linux_to_bsd_sockaddr(PTRIN(args->optval), &sa, &len);
1478 		if (error != 0)
1479 			return (error);
1480 
1481 		error = kern_setsockopt(td, args->s, level,
1482 		    name, sa, UIO_SYSSPACE, len);
1483 		free(sa, M_SONAME);
1484 	} else {
1485 		error = kern_setsockopt(td, args->s, level,
1486 		    name, PTRIN(args->optval), UIO_USERSPACE, args->optlen);
1487 	}
1488 
1489 	return (error);
1490 }
1491 
1492 int
1493 linux_getsockopt(struct thread *td, struct linux_getsockopt_args *args)
1494 {
1495 	l_timeval linux_tv;
1496 	struct timeval tv;
1497 	socklen_t tv_len, xulen, len;
1498 	struct sockaddr *sa;
1499 	struct xucred xu;
1500 	struct l_ucred lxu;
1501 	int error, level, name, newval;
1502 
1503 	level = linux_to_bsd_sockopt_level(args->level);
1504 	switch (level) {
1505 	case SOL_SOCKET:
1506 		name = linux_to_bsd_so_sockopt(args->optname);
1507 		switch (name) {
1508 		case SO_RCVTIMEO:
1509 			/* FALLTHROUGH */
1510 		case SO_SNDTIMEO:
1511 			tv_len = sizeof(tv);
1512 			error = kern_getsockopt(td, args->s, level,
1513 			    name, &tv, UIO_SYSSPACE, &tv_len);
1514 			if (error != 0)
1515 				return (error);
1516 			linux_tv.tv_sec = tv.tv_sec;
1517 			linux_tv.tv_usec = tv.tv_usec;
1518 			return (copyout(&linux_tv, PTRIN(args->optval),
1519 			    sizeof(linux_tv)));
1520 			/* NOTREACHED */
1521 		case LOCAL_PEERCRED:
1522 			if (args->optlen < sizeof(lxu))
1523 				return (EINVAL);
1524 			/*
1525 			 * LOCAL_PEERCRED is not served at the SOL_SOCKET level,
1526 			 * but by the Unix socket's level 0.
1527 			 */
1528 			level = 0;
1529 			xulen = sizeof(xu);
1530 			error = kern_getsockopt(td, args->s, level,
1531 			    name, &xu, UIO_SYSSPACE, &xulen);
1532 			if (error != 0)
1533 				return (error);
1534 			lxu.pid = xu.cr_pid;
1535 			lxu.uid = xu.cr_uid;
1536 			lxu.gid = xu.cr_gid;
1537 			return (copyout(&lxu, PTRIN(args->optval), sizeof(lxu)));
1538 			/* NOTREACHED */
1539 		case SO_ERROR:
1540 			len = sizeof(newval);
1541 			error = kern_getsockopt(td, args->s, level,
1542 			    name, &newval, UIO_SYSSPACE, &len);
1543 			if (error != 0)
1544 				return (error);
1545 			newval = -linux_to_bsd_errno(newval);
1546 			return (copyout(&newval, PTRIN(args->optval), len));
1547 			/* NOTREACHED */
1548 		default:
1549 			break;
1550 		}
1551 		break;
1552 	case IPPROTO_IP:
1553 		name = linux_to_bsd_ip_sockopt(args->optname);
1554 		break;
1555 	case IPPROTO_IPV6:
1556 		name = linux_to_bsd_ip6_sockopt(args->optname);
1557 		break;
1558 	case IPPROTO_TCP:
1559 		name = linux_to_bsd_tcp_sockopt(args->optname);
1560 		break;
1561 	default:
1562 		name = -1;
1563 		break;
1564 	}
1565 	if (name == -1) {
1566 		linux_msg(curthread,
1567 		    "unsupported getsockopt level %d optname %d",
1568 		    args->level, args->optname);
1569 		return (EINVAL);
1570 	}
1571 
1572 	if (name == IPV6_NEXTHOP) {
1573 		error = copyin(PTRIN(args->optlen), &len, sizeof(len));
1574                 if (error != 0)
1575                         return (error);
1576 		sa = malloc(len, M_SONAME, M_WAITOK);
1577 
1578 		error = kern_getsockopt(td, args->s, level,
1579 		    name, sa, UIO_SYSSPACE, &len);
1580 		if (error != 0)
1581 			goto out;
1582 
1583 		error = linux_copyout_sockaddr(sa, PTRIN(args->optval), len);
1584 		if (error == 0)
1585 			error = copyout(&len, PTRIN(args->optlen),
1586 			    sizeof(len));
1587 out:
1588 		free(sa, M_SONAME);
1589 	} else {
1590 		if (args->optval) {
1591 			error = copyin(PTRIN(args->optlen), &len, sizeof(len));
1592 			if (error != 0)
1593 				return (error);
1594 		}
1595 		error = kern_getsockopt(td, args->s, level,
1596 		    name, PTRIN(args->optval), UIO_USERSPACE, &len);
1597 		if (error == 0)
1598 			error = copyout(&len, PTRIN(args->optlen),
1599 			    sizeof(len));
1600 	}
1601 
1602 	return (error);
1603 }
1604 
1605 static int
1606 linux_sendfile_common(struct thread *td, l_int out, l_int in,
1607     l_loff_t *offset, l_size_t count)
1608 {
1609 	off_t bytes_read;
1610 	int error;
1611 	l_loff_t current_offset;
1612 	struct file *fp;
1613 
1614 	AUDIT_ARG_FD(in);
1615 	error = fget_read(td, in, &cap_pread_rights, &fp);
1616 	if (error != 0)
1617 		return (error);
1618 
1619 	if (offset != NULL) {
1620 		current_offset = *offset;
1621 	} else {
1622 		error = (fp->f_ops->fo_flags & DFLAG_SEEKABLE) != 0 ?
1623 		    fo_seek(fp, 0, SEEK_CUR, td) : ESPIPE;
1624 		if (error != 0)
1625 			goto drop;
1626 		current_offset = td->td_uretoff.tdu_off;
1627 	}
1628 
1629 	bytes_read = 0;
1630 
1631 	/* Linux cannot have 0 count. */
1632 	if (count <= 0 || current_offset < 0) {
1633 		error = EINVAL;
1634 		goto drop;
1635 	}
1636 
1637 	error = fo_sendfile(fp, out, NULL, NULL, current_offset, count,
1638 	    &bytes_read, 0, td);
1639 	if (error != 0)
1640 		goto drop;
1641 	current_offset += bytes_read;
1642 
1643 	if (offset != NULL) {
1644 		*offset = current_offset;
1645 	} else {
1646 		error = fo_seek(fp, current_offset, SEEK_SET, td);
1647 		if (error != 0)
1648 			goto drop;
1649 	}
1650 
1651 	td->td_retval[0] = (ssize_t)bytes_read;
1652 drop:
1653 	fdrop(fp, td);
1654 	return (error);
1655 }
1656 
1657 int
1658 linux_sendfile(struct thread *td, struct linux_sendfile_args *arg)
1659 {
1660 	/*
1661 	 * Differences between FreeBSD and Linux sendfile:
1662 	 * - Linux doesn't send anything when count is 0 (FreeBSD uses 0 to
1663 	 *   mean send the whole file.)  In linux_sendfile given fds are still
1664 	 *   checked for validity when the count is 0.
1665 	 * - Linux can send to any fd whereas FreeBSD only supports sockets.
1666 	 *   The same restriction follows for linux_sendfile.
1667 	 * - Linux doesn't have an equivalent for FreeBSD's flags and sf_hdtr.
1668 	 * - Linux takes an offset pointer and updates it to the read location.
1669 	 *   FreeBSD takes in an offset and a 'bytes read' parameter which is
1670 	 *   only filled if it isn't NULL.  We use this parameter to update the
1671 	 *   offset pointer if it exists.
1672 	 * - Linux sendfile returns bytes read on success while FreeBSD
1673 	 *   returns 0.  We use the 'bytes read' parameter to get this value.
1674 	 */
1675 
1676 	l_loff_t offset64;
1677 	l_long offset;
1678 	int ret;
1679 	int error;
1680 
1681 	if (arg->offset != NULL) {
1682 		error = copyin(arg->offset, &offset, sizeof(offset));
1683 		if (error != 0)
1684 			return (error);
1685 		offset64 = (l_loff_t)offset;
1686 	}
1687 
1688 	ret = linux_sendfile_common(td, arg->out, arg->in,
1689 	    arg->offset != NULL ? &offset64 : NULL, arg->count);
1690 
1691 	if (arg->offset != NULL) {
1692 #if defined(__i386__) || defined(__arm__) || \
1693     (defined(__amd64__) && defined(COMPAT_LINUX32))
1694 		if (offset64 > INT32_MAX)
1695 			return (EOVERFLOW);
1696 #endif
1697 		offset = (l_long)offset64;
1698 		error = copyout(&offset, arg->offset, sizeof(offset));
1699 		if (error != 0)
1700 			return (error);
1701 	}
1702 
1703 	return (ret);
1704 }
1705 
1706 #if defined(__i386__) || defined(__arm__) || \
1707     (defined(__amd64__) && defined(COMPAT_LINUX32))
1708 
1709 int
1710 linux_sendfile64(struct thread *td, struct linux_sendfile64_args *arg)
1711 {
1712 	l_loff_t offset;
1713 	int ret;
1714 	int error;
1715 
1716 	if (arg->offset != NULL) {
1717 		error = copyin(arg->offset, &offset, sizeof(offset));
1718 		if (error != 0)
1719 			return (error);
1720 	}
1721 
1722 	ret = linux_sendfile_common(td, arg->out, arg->in,
1723 		arg->offset != NULL ? &offset : NULL, arg->count);
1724 
1725 	if (arg->offset != NULL) {
1726 		error = copyout(&offset, arg->offset, sizeof(offset));
1727 		if (error != 0)
1728 			return (error);
1729 	}
1730 
1731 	return (ret);
1732 }
1733 
1734 /* Argument list sizes for linux_socketcall */
1735 static const unsigned char lxs_args_cnt[] = {
1736 	0 /* unused*/,		3 /* socket */,
1737 	3 /* bind */,		3 /* connect */,
1738 	2 /* listen */,		3 /* accept */,
1739 	3 /* getsockname */,	3 /* getpeername */,
1740 	4 /* socketpair */,	4 /* send */,
1741 	4 /* recv */,		6 /* sendto */,
1742 	6 /* recvfrom */,	2 /* shutdown */,
1743 	5 /* setsockopt */,	5 /* getsockopt */,
1744 	3 /* sendmsg */,	3 /* recvmsg */,
1745 	4 /* accept4 */,	5 /* recvmmsg */,
1746 	4 /* sendmmsg */,	4 /* sendfile */
1747 };
1748 #define	LINUX_ARGS_CNT		(nitems(lxs_args_cnt) - 1)
1749 #define	LINUX_ARG_SIZE(x)	(lxs_args_cnt[x] * sizeof(l_ulong))
1750 
1751 int
1752 linux_socketcall(struct thread *td, struct linux_socketcall_args *args)
1753 {
1754 	l_ulong a[6];
1755 #if defined(__amd64__) && defined(COMPAT_LINUX32)
1756 	register_t l_args[6];
1757 #endif
1758 	void *arg;
1759 	int error;
1760 
1761 	if (args->what < LINUX_SOCKET || args->what > LINUX_ARGS_CNT)
1762 		return (EINVAL);
1763 	error = copyin(PTRIN(args->args), a, LINUX_ARG_SIZE(args->what));
1764 	if (error != 0)
1765 		return (error);
1766 
1767 #if defined(__amd64__) && defined(COMPAT_LINUX32)
1768 	for (int i = 0; i < lxs_args_cnt[args->what]; ++i)
1769 		l_args[i] = a[i];
1770 	arg = l_args;
1771 #else
1772 	arg = a;
1773 #endif
1774 	switch (args->what) {
1775 	case LINUX_SOCKET:
1776 		return (linux_socket(td, arg));
1777 	case LINUX_BIND:
1778 		return (linux_bind(td, arg));
1779 	case LINUX_CONNECT:
1780 		return (linux_connect(td, arg));
1781 	case LINUX_LISTEN:
1782 		return (linux_listen(td, arg));
1783 	case LINUX_ACCEPT:
1784 		return (linux_accept(td, arg));
1785 	case LINUX_GETSOCKNAME:
1786 		return (linux_getsockname(td, arg));
1787 	case LINUX_GETPEERNAME:
1788 		return (linux_getpeername(td, arg));
1789 	case LINUX_SOCKETPAIR:
1790 		return (linux_socketpair(td, arg));
1791 	case LINUX_SEND:
1792 		return (linux_send(td, arg));
1793 	case LINUX_RECV:
1794 		return (linux_recv(td, arg));
1795 	case LINUX_SENDTO:
1796 		return (linux_sendto(td, arg));
1797 	case LINUX_RECVFROM:
1798 		return (linux_recvfrom(td, arg));
1799 	case LINUX_SHUTDOWN:
1800 		return (linux_shutdown(td, arg));
1801 	case LINUX_SETSOCKOPT:
1802 		return (linux_setsockopt(td, arg));
1803 	case LINUX_GETSOCKOPT:
1804 		return (linux_getsockopt(td, arg));
1805 	case LINUX_SENDMSG:
1806 		return (linux_sendmsg(td, arg));
1807 	case LINUX_RECVMSG:
1808 		return (linux_recvmsg(td, arg));
1809 	case LINUX_ACCEPT4:
1810 		return (linux_accept4(td, arg));
1811 	case LINUX_RECVMMSG:
1812 		return (linux_recvmmsg(td, arg));
1813 	case LINUX_SENDMMSG:
1814 		return (linux_sendmmsg(td, arg));
1815 	case LINUX_SENDFILE:
1816 		return (linux_sendfile(td, arg));
1817 	}
1818 
1819 	linux_msg(td, "socket type %d not implemented", args->what);
1820 	return (ENOSYS);
1821 }
1822 #endif /* __i386__ || __arm__ || (__amd64__ && COMPAT_LINUX32) */
1823