xref: /dragonfly/sys/kern/uipc_syscalls.c (revision 655933d6)
1 /*
2  * Copyright (c) 1982, 1986, 1989, 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * sendfile(2) and related extensions:
6  * Copyright (c) 1998, David Greenman. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)uipc_syscalls.c	8.4 (Berkeley) 2/21/94
33  * $FreeBSD: src/sys/kern/uipc_syscalls.c,v 1.65.2.17 2003/04/04 17:11:16 tegge Exp $
34  */
35 
36 #include "opt_ktrace.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/sysmsg.h>
42 #include <sys/malloc.h>
43 #include <sys/filedesc.h>
44 #include <sys/event.h>
45 #include <sys/proc.h>
46 #include <sys/fcntl.h>
47 #include <sys/file.h>
48 #include <sys/filio.h>
49 #include <sys/kern_syscall.h>
50 #include <sys/mbuf.h>
51 #include <sys/protosw.h>
52 #include <sys/sfbuf.h>
53 #include <sys/socket.h>
54 #include <sys/socketvar.h>
55 #include <sys/socketops.h>
56 #include <sys/uio.h>
57 #include <sys/vnode.h>
58 #include <sys/lock.h>
59 #include <sys/mount.h>
60 #include <sys/jail.h>
61 #ifdef KTRACE
62 #include <sys/ktrace.h>
63 #endif
64 #include <vm/vm.h>
65 #include <vm/vm_object.h>
66 #include <vm/vm_page.h>
67 #include <vm/vm_pageout.h>
68 #include <vm/vm_kern.h>
69 #include <vm/vm_extern.h>
70 #include <sys/file2.h>
71 #include <sys/signalvar.h>
72 #include <sys/serialize.h>
73 
74 #include <sys/thread2.h>
75 #include <sys/msgport2.h>
76 #include <sys/socketvar2.h>
77 #include <net/netmsg2.h>
78 #include <vm/vm_page2.h>
79 
80 extern int use_soaccept_pred_fast;
81 extern int use_sendfile_async;
82 extern int use_soconnect_async;
83 
84 /*
85  * System call interface to the socket abstraction.
86  */
87 
88 extern	struct fileops socketops;
89 
90 /*
91  * socket_args(int domain, int type, int protocol)
92  */
93 int
94 kern_socket(int domain, int type, int protocol, int *res)
95 {
96 	struct thread *td = curthread;
97 	struct filedesc *fdp = td->td_proc->p_fd;
98 	struct socket *so;
99 	struct file *fp;
100 	int fd, error;
101 	u_int fflags = 0;
102 	int oflags = 0;
103 
104 	KKASSERT(td->td_lwp);
105 
106 	if (type & SOCK_NONBLOCK) {
107 		type &= ~SOCK_NONBLOCK;
108 		fflags |= FNONBLOCK;
109 	}
110 	if (type & SOCK_CLOEXEC) {
111 		type &= ~SOCK_CLOEXEC;
112 		oflags |= O_CLOEXEC;
113 	}
114 
115 	error = falloc(td->td_lwp, &fp, &fd);
116 	if (error)
117 		return (error);
118 	error = socreate(domain, &so, type, protocol, td);
119 	if (error) {
120 		fsetfd(fdp, NULL, fd);
121 	} else {
122 		fp->f_type = DTYPE_SOCKET;
123 		fp->f_flag = FREAD | FWRITE | fflags;
124 		fp->f_ops = &socketops;
125 		fp->f_data = so;
126 		if (oflags & O_CLOEXEC)
127 			fdp->fd_files[fd].fileflags |= UF_EXCLOSE;
128 		*res = fd;
129 		fsetfd(fdp, fp, fd);
130 	}
131 	fdrop(fp);
132 	return (error);
133 }
134 
135 /*
136  * MPALMOSTSAFE
137  */
138 int
139 sys_socket(struct sysmsg *sysmsg, const struct socket_args *uap)
140 {
141 	int error;
142 
143 	error = kern_socket(uap->domain, uap->type, uap->protocol,
144 			    &sysmsg->sysmsg_iresult);
145 
146 	return (error);
147 }
148 
149 int
150 kern_bind(int s, struct sockaddr *sa)
151 {
152 	struct thread *td = curthread;
153 	struct file *fp;
154 	int error;
155 
156 	error = holdsock(td, s, &fp);
157 	if (error)
158 		return (error);
159 	error = sobind((struct socket *)fp->f_data, sa, td);
160 	dropfp(td, s, fp);
161 
162 	return (error);
163 }
164 
165 /*
166  * bind_args(int s, caddr_t name, int namelen)
167  *
168  * MPALMOSTSAFE
169  */
170 int
171 sys_bind(struct sysmsg *sysmsg, const struct bind_args *uap)
172 {
173 	struct sockaddr *sa;
174 	int error;
175 
176 	error = getsockaddr(&sa, uap->name, uap->namelen);
177 	if (error)
178 		return (error);
179 	if (!prison_remote_ip(curthread, sa)) {
180 		kfree(sa, M_SONAME);
181 		return EAFNOSUPPORT;
182 	}
183 	error = kern_bind(uap->s, sa);
184 	kfree(sa, M_SONAME);
185 
186 	return (error);
187 }
188 
189 int
190 kern_listen(int s, int backlog)
191 {
192 	struct thread *td = curthread;
193 	struct file *fp;
194 	int error;
195 
196 	error = holdsock(td, s, &fp);
197 	if (error)
198 		return (error);
199 	error = solisten((struct socket *)fp->f_data, backlog, td);
200 	dropfp(td, s, fp);
201 
202 	return (error);
203 }
204 
205 /*
206  * listen_args(int s, int backlog)
207  *
208  * MPALMOSTSAFE
209  */
210 int
211 sys_listen(struct sysmsg *sysmsg, const struct listen_args *uap)
212 {
213 	int error;
214 
215 	error = kern_listen(uap->s, uap->backlog);
216 	return (error);
217 }
218 
219 /*
220  * Returns the accepted socket as well.
221  *
222  * NOTE!  The sockets sitting on so_comp/so_incomp might have 0 refs, the
223  *	  pool token is absolutely required to avoid a sofree() race,
224  *	  as well as to avoid tailq handling races.
225  */
226 static boolean_t
227 soaccept_predicate(struct netmsg_so_notify *msg)
228 {
229 	struct socket *head = msg->base.nm_so;
230 	struct socket *so;
231 
232 	if (head->so_error != 0) {
233 		msg->base.lmsg.ms_error = head->so_error;
234 		return (TRUE);
235 	}
236 	lwkt_getpooltoken(head);
237 	if (!TAILQ_EMPTY(&head->so_comp)) {
238 		/* Abuse nm_so field as copy in/copy out parameter. XXX JH */
239 		so = TAILQ_FIRST(&head->so_comp);
240 		KKASSERT((so->so_state & (SS_INCOMP | SS_COMP)) == SS_COMP);
241 		TAILQ_REMOVE(&head->so_comp, so, so_list);
242 		head->so_qlen--;
243 		soclrstate(so, SS_COMP);
244 
245 		/*
246 		 * Keep a reference before clearing the so_head
247 		 * to avoid racing socket close in netisr.
248 		 */
249 		soreference(so);
250 		so->so_head = NULL;
251 
252 		lwkt_relpooltoken(head);
253 
254 		msg->base.lmsg.ms_error = 0;
255 		msg->base.nm_so = so;
256 		return (TRUE);
257 	}
258 	lwkt_relpooltoken(head);
259 	if (head->so_state & SS_CANTRCVMORE) {
260 		msg->base.lmsg.ms_error = ECONNABORTED;
261 		return (TRUE);
262 	}
263 	if (msg->nm_fflags & FNONBLOCK) {
264 		msg->base.lmsg.ms_error = EWOULDBLOCK;
265 		return (TRUE);
266 	}
267 
268 	return (FALSE);
269 }
270 
271 /*
272  * The second argument to kern_accept() is a handle to a struct sockaddr.
273  * This allows kern_accept() to return a pointer to an allocated struct
274  * sockaddr which must be freed later with FREE().  The caller must
275  * initialize *name to NULL.
276  */
277 int
278 kern_accept(int s, int fflags, struct sockaddr **name, int *namelen, int *res,
279     int sockflags)
280 {
281 	struct thread *td = curthread;
282 	struct filedesc *fdp = td->td_proc->p_fd;
283 	struct file *lfp = NULL;
284 	struct file *nfp = NULL;
285 	struct sockaddr *sa;
286 	struct socket *head, *so;
287 	struct netmsg_so_notify msg;
288 	int fd;
289 	u_int fflag;		/* type must match fp->f_flag */
290 	int error, tmp;
291 
292 	*res = -1;
293 	if (name && namelen && *namelen < 0)
294 		return (EINVAL);
295 
296 	error = holdsock(td, s, &lfp);
297 	if (error)
298 		return (error);
299 
300 	error = falloc(td->td_lwp, &nfp, &fd);
301 	if (error) {		/* Probably ran out of file descriptors. */
302 		fdrop(lfp);
303 		return (error);
304 	}
305 	head = (struct socket *)lfp->f_data;
306 	if ((head->so_options & SO_ACCEPTCONN) == 0) {
307 		error = EINVAL;
308 		goto done;
309 	}
310 
311 	if (fflags & O_FBLOCKING)
312 		fflags |= lfp->f_flag & ~FNONBLOCK;
313 	else if (fflags & O_FNONBLOCKING)
314 		fflags |= lfp->f_flag | FNONBLOCK;
315 	else
316 		fflags = lfp->f_flag;
317 
318 	if (use_soaccept_pred_fast) {
319 		boolean_t pred;
320 
321 		/* Initialize necessary parts for soaccept_predicate() */
322 		netmsg_init(&msg.base, head, &netisr_apanic_rport, 0, NULL);
323 		msg.nm_fflags = fflags;
324 
325 		lwkt_getpooltoken(head);
326 		pred = soaccept_predicate(&msg);
327 		lwkt_relpooltoken(head);
328 
329 		if (pred) {
330 			error = msg.base.lmsg.ms_error;
331 			if (error)
332 				goto done;
333 			else
334 				goto accepted;
335 		}
336 	}
337 
338 	/* optimize for uniprocessor case later XXX JH */
339 	netmsg_init_abortable(&msg.base, head, &curthread->td_msgport,
340 			      0, netmsg_so_notify, netmsg_so_notify_doabort);
341 	msg.nm_predicate = soaccept_predicate;
342 	msg.nm_fflags = fflags;
343 	msg.nm_etype = NM_REVENT;
344 	error = lwkt_domsg(head->so_port, &msg.base.lmsg, PCATCH);
345 	if (error)
346 		goto done;
347 
348 accepted:
349 	/*
350 	 * At this point we have the connection that's ready to be accepted.
351 	 *
352 	 * NOTE! soaccept_predicate() ref'd so for us, and soaccept() expects
353 	 * 	 to eat the ref and turn it into a descriptor.
354 	 */
355 	so = msg.base.nm_so;
356 
357 	fflag = lfp->f_flag;
358 
359 	/* connection has been removed from the listen queue */
360 	KNOTE(&head->so_rcv.ssb_kq.ki_note, 0);
361 
362 	if (sockflags & SOCK_KERN_NOINHERIT) {
363 		fflag &= ~(FASYNC | FNONBLOCK);
364 		if (sockflags & SOCK_NONBLOCK)
365 			fflag |= FNONBLOCK;
366 	} else {
367 		if (head->so_sigio != NULL)
368 			fsetown(fgetown(&head->so_sigio), &so->so_sigio);
369 	}
370 
371 	nfp->f_type = DTYPE_SOCKET;
372 	nfp->f_flag = fflag;
373 	nfp->f_ops = &socketops;
374 	nfp->f_data = so;
375 	/* Sync socket async state with file flags */
376 	tmp = fflag & FASYNC;
377 	fo_ioctl(nfp, FIOASYNC, (caddr_t)&tmp, td->td_ucred, NULL);
378 
379 	sa = NULL;
380 	if (so->so_faddr != NULL) {
381 		sa = so->so_faddr;
382 		so->so_faddr = NULL;
383 
384 		soaccept_generic(so);
385 		error = 0;
386 	} else {
387 		error = soaccept(so, &sa);
388 	}
389 
390 	/*
391 	 * Set the returned name and namelen as applicable.  Set the returned
392 	 * namelen to 0 for older code which might ignore the return value
393 	 * from accept.
394 	 */
395 	if (error == 0) {
396 		if (sa && name && namelen) {
397 			if (*namelen > sa->sa_len)
398 				*namelen = sa->sa_len;
399 			*name = sa;
400 		} else {
401 			if (sa)
402 				kfree(sa, M_SONAME);
403 		}
404 	}
405 
406 done:
407 	/*
408 	 * If an error occured clear the reserved descriptor, else associate
409 	 * nfp with it.
410 	 *
411 	 * Note that *res is normally ignored if an error is returned but
412 	 * a syscall message will still have access to the result code.
413 	 */
414 	if (error) {
415 		fsetfd(fdp, NULL, fd);
416 	} else {
417 		if (sockflags & SOCK_CLOEXEC)
418 			fdp->fd_files[fd].fileflags |= UF_EXCLOSE;
419 		*res = fd;
420 		fsetfd(fdp, nfp, fd);
421 	}
422 	fdrop(nfp);
423 	dropfp(td, s, lfp);
424 
425 	return (error);
426 }
427 
428 /*
429  * accept(int s, caddr_t name, int *anamelen)
430  *
431  * MPALMOSTSAFE
432  */
433 int
434 sys_accept(struct sysmsg *sysmsg, const struct accept_args *uap)
435 {
436 	struct sockaddr *sa = NULL;
437 	int sa_len;
438 	int error;
439 
440 	if (uap->name) {
441 		error = copyin(uap->anamelen, &sa_len, sizeof(sa_len));
442 		if (error)
443 			return (error);
444 
445 		error = kern_accept(uap->s, 0, &sa, &sa_len,
446 				    &sysmsg->sysmsg_iresult, 0);
447 
448 		if (error == 0) {
449 			prison_local_ip(curthread, sa);
450 			error = copyout(sa, uap->name, sa_len);
451 		}
452 		if (error == 0) {
453 			error = copyout(&sa_len, uap->anamelen,
454 					sizeof(*uap->anamelen));
455 		}
456 		if (sa)
457 			kfree(sa, M_SONAME);
458 	} else {
459 		error = kern_accept(uap->s, 0, NULL, 0,
460 				    &sysmsg->sysmsg_iresult, 0);
461 	}
462 	return (error);
463 }
464 
465 /*
466  * extaccept(int s, int fflags, caddr_t name, int *anamelen)
467  *
468  * MPALMOSTSAFE
469  */
470 int
471 sys_extaccept(struct sysmsg *sysmsg, const struct extaccept_args *uap)
472 {
473 	struct sockaddr *sa = NULL;
474 	int sa_len;
475 	int error;
476 	int fflags = uap->flags & O_FMASK;
477 
478 	if (uap->name) {
479 		error = copyin(uap->anamelen, &sa_len, sizeof(sa_len));
480 		if (error)
481 			return (error);
482 
483 		error = kern_accept(uap->s, fflags, &sa, &sa_len,
484 				    &sysmsg->sysmsg_iresult, 0);
485 
486 		if (error == 0) {
487 			prison_local_ip(curthread, sa);
488 			error = copyout(sa, uap->name, sa_len);
489 		}
490 		if (error == 0) {
491 			error = copyout(&sa_len, uap->anamelen,
492 			    sizeof(*uap->anamelen));
493 		}
494 		if (sa)
495 			kfree(sa, M_SONAME);
496 	} else {
497 		error = kern_accept(uap->s, fflags, NULL, 0,
498 				    &sysmsg->sysmsg_iresult, 0);
499 	}
500 	return (error);
501 }
502 
503 /*
504  * accept4(int s, caddr_t name, int *anamelen, int flags)
505  *
506  * MPALMOSTSAFE
507  */
508 int
509 sys_accept4(struct sysmsg *sysmsg, const struct accept4_args *uap)
510 {
511 	struct sockaddr *sa = NULL;
512 	int sa_len;
513 	int error;
514 	int sockflags;
515 
516 	if (uap->flags & ~(SOCK_NONBLOCK | SOCK_CLOEXEC))
517 		return (EINVAL);
518 	sockflags = uap->flags | SOCK_KERN_NOINHERIT;
519 
520 	if (uap->name) {
521 		error = copyin(uap->anamelen, &sa_len, sizeof(sa_len));
522 		if (error)
523 			return (error);
524 
525 		error = kern_accept(uap->s, 0, &sa, &sa_len,
526 				    &sysmsg->sysmsg_iresult, sockflags);
527 
528 		if (error == 0) {
529 			prison_local_ip(curthread, sa);
530 			error = copyout(sa, uap->name, sa_len);
531 		}
532 		if (error == 0) {
533 			error = copyout(&sa_len, uap->anamelen,
534 					sizeof(*uap->anamelen));
535 		}
536 		if (sa)
537 			kfree(sa, M_SONAME);
538 	} else {
539 		error = kern_accept(uap->s, 0, NULL, 0,
540 				    &sysmsg->sysmsg_iresult, sockflags);
541 	}
542 	return (error);
543 }
544 
545 /*
546  * Returns TRUE if predicate satisfied.
547  */
548 static boolean_t
549 soconnected_predicate(struct netmsg_so_notify *msg)
550 {
551 	struct socket *so = msg->base.nm_so;
552 
553 	/* check predicate */
554 	if (!(so->so_state & SS_ISCONNECTING) || so->so_error != 0) {
555 		msg->base.lmsg.ms_error = so->so_error;
556 		return (TRUE);
557 	}
558 
559 	return (FALSE);
560 }
561 
562 int
563 kern_connect(int s, int fflags, struct sockaddr *sa)
564 {
565 	struct thread *td = curthread;
566 	struct file *fp;
567 	struct socket *so;
568 	int error, interrupted = 0;
569 
570 	error = holdsock(td, s, &fp);
571 	if (error)
572 		return (error);
573 	so = (struct socket *)fp->f_data;
574 
575 	if (fflags & O_FBLOCKING)
576 		/* fflags &= ~FNONBLOCK; */;
577 	else if (fflags & O_FNONBLOCKING)
578 		fflags |= FNONBLOCK;
579 	else
580 		fflags = fp->f_flag;
581 
582 	if (so->so_state & SS_ISCONNECTING) {
583 		error = EALREADY;
584 		goto done;
585 	}
586 	error = soconnect(so, sa, td, use_soconnect_async ? FALSE : TRUE);
587 	if (error)
588 		goto bad;
589 	if ((fflags & FNONBLOCK) && (so->so_state & SS_ISCONNECTING)) {
590 		error = EINPROGRESS;
591 		goto done;
592 	}
593 	if ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
594 		struct netmsg_so_notify msg;
595 
596 		netmsg_init_abortable(&msg.base, so,
597 				      &curthread->td_msgport,
598 				      0,
599 				      netmsg_so_notify,
600 				      netmsg_so_notify_doabort);
601 		msg.nm_predicate = soconnected_predicate;
602 		msg.nm_etype = NM_REVENT;
603 		error = lwkt_domsg(so->so_port, &msg.base.lmsg, PCATCH);
604 		if (error == EINTR || error == ERESTART)
605 			interrupted = 1;
606 	}
607 	if (error == 0) {
608 		error = so->so_error;
609 		so->so_error = 0;
610 	}
611 bad:
612 	if (!interrupted)
613 		soclrstate(so, SS_ISCONNECTING);
614 	if (error == ERESTART)
615 		error = EINTR;
616 done:
617 	dropfp(td, s, fp);
618 
619 	return (error);
620 }
621 
622 /*
623  * connect_args(int s, caddr_t name, int namelen)
624  *
625  * MPALMOSTSAFE
626  */
627 int
628 sys_connect(struct sysmsg *sysmsg, const struct connect_args *uap)
629 {
630 	struct sockaddr *sa;
631 	int error;
632 
633 	error = getsockaddr(&sa, uap->name, uap->namelen);
634 	if (error)
635 		return (error);
636 	if (!prison_remote_ip(curthread, sa)) {
637 		kfree(sa, M_SONAME);
638 		return EAFNOSUPPORT;
639 	}
640 	error = kern_connect(uap->s, 0, sa);
641 	kfree(sa, M_SONAME);
642 
643 	return (error);
644 }
645 
646 /*
647  * connect_args(int s, int fflags, caddr_t name, int namelen)
648  *
649  * MPALMOSTSAFE
650  */
651 int
652 sys_extconnect(struct sysmsg *sysmsg, const struct extconnect_args *uap)
653 {
654 	struct sockaddr *sa;
655 	int error;
656 	int fflags = uap->flags & O_FMASK;
657 
658 	error = getsockaddr(&sa, uap->name, uap->namelen);
659 	if (error)
660 		return (error);
661 	if (!prison_remote_ip(curthread, sa)) {
662 		kfree(sa, M_SONAME);
663 		return EAFNOSUPPORT;
664 	}
665 	error = kern_connect(uap->s, fflags, sa);
666 	kfree(sa, M_SONAME);
667 
668 	return (error);
669 }
670 
671 int
672 kern_socketpair(int domain, int type, int protocol, int *sv)
673 {
674 	struct thread *td = curthread;
675 	struct filedesc *fdp;
676 	struct file *fp1, *fp2;
677 	struct socket *so1, *so2;
678 	struct ucred *cred = curthread->td_ucred;
679 	int fd1, fd2, error;
680 	u_int fflags = 0;
681 	int oflags = 0;
682 
683 	if (type & SOCK_NONBLOCK) {
684 		type &= ~SOCK_NONBLOCK;
685 		fflags |= FNONBLOCK;
686 	}
687 	if (type & SOCK_CLOEXEC) {
688 		type &= ~SOCK_CLOEXEC;
689 		oflags |= O_CLOEXEC;
690 	}
691 
692 	fdp = td->td_proc->p_fd;
693 	error = socreate(domain, &so1, type, protocol, td);
694 	if (error)
695 		return (error);
696 	error = socreate(domain, &so2, type, protocol, td);
697 	if (error)
698 		goto free1;
699 	error = falloc(td->td_lwp, &fp1, &fd1);
700 	if (error)
701 		goto free2;
702 	sv[0] = fd1;
703 	fp1->f_data = so1;
704 	error = falloc(td->td_lwp, &fp2, &fd2);
705 	if (error)
706 		goto free3;
707 	fp2->f_data = so2;
708 	sv[1] = fd2;
709 	error = soconnect2(so1, so2, cred);
710 	if (error)
711 		goto free4;
712 	if (type == SOCK_DGRAM) {
713 		/*
714 		 * Datagram socket connection is asymmetric.
715 		 */
716 		 error = soconnect2(so2, so1, cred);
717 		 if (error)
718 			goto free4;
719 	}
720 	fp1->f_type = fp2->f_type = DTYPE_SOCKET;
721 	fp1->f_flag = fp2->f_flag = FREAD|FWRITE|fflags;
722 	fp1->f_ops = fp2->f_ops = &socketops;
723 	if (oflags & O_CLOEXEC) {
724 		fdp->fd_files[fd1].fileflags |= UF_EXCLOSE;
725 		fdp->fd_files[fd2].fileflags |= UF_EXCLOSE;
726 	}
727 	fsetfd(fdp, fp1, fd1);
728 	fsetfd(fdp, fp2, fd2);
729 	fdrop(fp1);
730 	fdrop(fp2);
731 	return (error);
732 free4:
733 	fsetfd(fdp, NULL, fd2);
734 	fdrop(fp2);
735 free3:
736 	fsetfd(fdp, NULL, fd1);
737 	fdrop(fp1);
738 free2:
739 	(void)soclose(so2, 0);
740 free1:
741 	(void)soclose(so1, 0);
742 	return (error);
743 }
744 
745 /*
746  * socketpair(int domain, int type, int protocol, int *rsv)
747  */
748 int
749 sys_socketpair(struct sysmsg *sysmsg, const struct socketpair_args *uap)
750 {
751 	int error, sockv[2];
752 
753 	error = kern_socketpair(uap->domain, uap->type, uap->protocol, sockv);
754 
755 	if (error == 0) {
756 		error = copyout(sockv, uap->rsv, sizeof(sockv));
757 
758 		if (error != 0) {
759 			kern_close(sockv[0]);
760 			kern_close(sockv[1]);
761 		}
762 	}
763 
764 	return (error);
765 }
766 
767 int
768 kern_sendmsg(int s, struct sockaddr *sa, struct uio *auio,
769 	     struct mbuf *control, int flags, size_t *res)
770 {
771 	struct thread *td = curthread;
772 	struct lwp *lp = td->td_lwp;
773 	struct proc *p = td->td_proc;
774 	struct file *fp;
775 	size_t len;
776 	int error;
777 	struct socket *so;
778 #ifdef KTRACE
779 	struct iovec *ktriov = NULL;
780 	struct uio ktruio;
781 #endif
782 
783 	error = holdsock(td, s, &fp);
784 	if (error)
785 		return (error);
786 #ifdef KTRACE
787 	if (KTRPOINT(td, KTR_GENIO)) {
788 		int iovlen = auio->uio_iovcnt * sizeof (struct iovec);
789 
790 		ktriov = kmalloc(iovlen, M_TEMP, M_WAITOK);
791 		bcopy((caddr_t)auio->uio_iov, (caddr_t)ktriov, iovlen);
792 		ktruio = *auio;
793 	}
794 #endif
795 	len = auio->uio_resid;
796 	so = (struct socket *)fp->f_data;
797 	if ((flags & (MSG_FNONBLOCKING|MSG_FBLOCKING)) == 0) {
798 		if (fp->f_flag & FNONBLOCK)
799 			flags |= MSG_FNONBLOCKING;
800 	}
801 	error = so_pru_sosend(so, sa, auio, NULL, control, flags, td);
802 	if (error) {
803 		if (auio->uio_resid != len && (error == ERESTART ||
804 		    error == EINTR || error == EWOULDBLOCK))
805 			error = 0;
806 		if (error == EPIPE && !(flags & MSG_NOSIGNAL) &&
807 		    !(so->so_options & SO_NOSIGPIPE))
808 			lwpsignal(p, lp, SIGPIPE);
809 	}
810 #ifdef KTRACE
811 	if (ktriov != NULL) {
812 		if (error == 0) {
813 			ktruio.uio_iov = ktriov;
814 			ktruio.uio_resid = len - auio->uio_resid;
815 			ktrgenio(lp, s, UIO_WRITE, &ktruio, error);
816 		}
817 		kfree(ktriov, M_TEMP);
818 	}
819 #endif
820 	if (error == 0)
821 		*res  = len - auio->uio_resid;
822 	dropfp(td, s, fp);
823 
824 	return (error);
825 }
826 
827 /*
828  * sendto_args(int s, caddr_t buf, size_t len, int flags, caddr_t to, int tolen)
829  *
830  * MPALMOSTSAFE
831  */
832 int
833 sys_sendto(struct sysmsg *sysmsg, const struct sendto_args *uap)
834 {
835 	struct thread *td = curthread;
836 	struct uio auio;
837 	struct iovec aiov;
838 	struct sockaddr *sa = NULL;
839 	int error;
840 
841 	if (uap->to) {
842 		error = getsockaddr(&sa, uap->to, uap->tolen);
843 		if (error)
844 			return (error);
845 		if (!prison_remote_ip(curthread, sa)) {
846 			kfree(sa, M_SONAME);
847 			return EAFNOSUPPORT;
848 		}
849 	}
850 	aiov.iov_base = uap->buf;
851 	aiov.iov_len = uap->len;
852 	auio.uio_iov = &aiov;
853 	auio.uio_iovcnt = 1;
854 	auio.uio_offset = 0;
855 	auio.uio_resid = uap->len;
856 	auio.uio_segflg = UIO_USERSPACE;
857 	auio.uio_rw = UIO_WRITE;
858 	auio.uio_td = td;
859 
860 	error = kern_sendmsg(uap->s, sa, &auio, NULL, uap->flags,
861 			     &sysmsg->sysmsg_szresult);
862 
863 	if (sa)
864 		kfree(sa, M_SONAME);
865 	return (error);
866 }
867 
868 /*
869  * sendmsg_args(int s, caddr_t msg, int flags)
870  *
871  * MPALMOSTSAFE
872  */
873 int
874 sys_sendmsg(struct sysmsg *sysmsg, const struct sendmsg_args *uap)
875 {
876 	struct thread *td = curthread;
877 	struct msghdr msg;
878 	struct uio auio;
879 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
880 	struct sockaddr *sa = NULL;
881 	struct mbuf *control = NULL;
882 	int error;
883 
884 	error = copyin(uap->msg, (caddr_t)&msg, sizeof(msg));
885 	if (error)
886 		return (error);
887 
888 	/*
889 	 * Conditionally copyin msg.msg_name.
890 	 */
891 	if (msg.msg_name) {
892 		error = getsockaddr(&sa, msg.msg_name, msg.msg_namelen);
893 		if (error)
894 			return (error);
895 		if (!prison_remote_ip(curthread, sa)) {
896 			kfree(sa, M_SONAME);
897 			return EAFNOSUPPORT;
898 		}
899 	}
900 
901 	/*
902 	 * Populate auio.
903 	 */
904 	error = iovec_copyin(msg.msg_iov, &iov, aiov, msg.msg_iovlen,
905 			     &auio.uio_resid);
906 	if (error)
907 		goto cleanup2;
908 	auio.uio_iov = iov;
909 	auio.uio_iovcnt = msg.msg_iovlen;
910 	auio.uio_offset = 0;
911 	auio.uio_segflg = UIO_USERSPACE;
912 	auio.uio_rw = UIO_WRITE;
913 	auio.uio_td = td;
914 
915 	/*
916 	 * Conditionally copyin msg.msg_control.
917 	 */
918 	if (msg.msg_control) {
919 		if (msg.msg_controllen < sizeof(struct cmsghdr) ||
920 		    msg.msg_controllen > MLEN) {
921 			error = EINVAL;
922 			goto cleanup;
923 		}
924 		control = m_get(M_WAITOK, MT_CONTROL);
925 		if (control == NULL) {
926 			error = ENOBUFS;
927 			goto cleanup;
928 		}
929 		control->m_len = msg.msg_controllen;
930 		error = copyin(msg.msg_control, mtod(control, caddr_t),
931 			       msg.msg_controllen);
932 		if (error) {
933 			m_free(control);
934 			goto cleanup;
935 		}
936 	}
937 
938 	error = kern_sendmsg(uap->s, sa, &auio, control, uap->flags,
939 			     &sysmsg->sysmsg_szresult);
940 
941 cleanup:
942 	iovec_free(&iov, aiov);
943 cleanup2:
944 	if (sa)
945 		kfree(sa, M_SONAME);
946 	return (error);
947 }
948 
949 /*
950  * kern_recvmsg() takes a handle to sa and control.  If the handle is non-
951  * null, it returns a dynamically allocated struct sockaddr and an mbuf.
952  * Don't forget to FREE() and m_free() these if they are returned.
953  */
954 int
955 kern_recvmsg(int s, struct sockaddr **sa, struct uio *auio,
956 	     struct mbuf **control, int *flags, size_t *res)
957 {
958 	struct thread *td = curthread;
959 	struct file *fp;
960 	size_t len;
961 	int error;
962 	int lflags;
963 	struct socket *so;
964 #ifdef KTRACE
965 	struct iovec *ktriov = NULL;
966 	struct uio ktruio;
967 #endif
968 
969 	error = holdsock(td, s, &fp);
970 	if (error)
971 		return (error);
972 #ifdef KTRACE
973 	if (KTRPOINT(td, KTR_GENIO)) {
974 		int iovlen = auio->uio_iovcnt * sizeof (struct iovec);
975 
976 		ktriov = kmalloc(iovlen, M_TEMP, M_WAITOK);
977 		bcopy(auio->uio_iov, ktriov, iovlen);
978 		ktruio = *auio;
979 	}
980 #endif
981 	len = auio->uio_resid;
982 	so = (struct socket *)fp->f_data;
983 
984 	if (flags == NULL || (*flags & (MSG_FNONBLOCKING|MSG_FBLOCKING)) == 0) {
985 		if (fp->f_flag & FNONBLOCK) {
986 			if (flags) {
987 				*flags |= MSG_FNONBLOCKING;
988 			} else {
989 				lflags = MSG_FNONBLOCKING;
990 				flags = &lflags;
991 			}
992 		}
993 	}
994 
995 	error = so_pru_soreceive(so, sa, auio, NULL, control, flags);
996 	if (error) {
997 		if (auio->uio_resid != len && (error == ERESTART ||
998 		    error == EINTR || error == EWOULDBLOCK))
999 			error = 0;
1000 	}
1001 #ifdef KTRACE
1002 	if (ktriov != NULL) {
1003 		if (error == 0) {
1004 			ktruio.uio_iov = ktriov;
1005 			ktruio.uio_resid = len - auio->uio_resid;
1006 			ktrgenio(td->td_lwp, s, UIO_READ, &ktruio, error);
1007 		}
1008 		kfree(ktriov, M_TEMP);
1009 	}
1010 #endif
1011 	if (error == 0)
1012 		*res = len - auio->uio_resid;
1013 	dropfp(td, s, fp);
1014 
1015 	return (error);
1016 }
1017 
1018 /*
1019  * recvfrom_args(int s, caddr_t buf, size_t len, int flags,
1020  *			caddr_t from, int *fromlenaddr)
1021  *
1022  * MPALMOSTSAFE
1023  */
1024 int
1025 sys_recvfrom(struct sysmsg *sysmsg, const struct recvfrom_args *uap)
1026 {
1027 	struct thread *td = curthread;
1028 	struct uio auio;
1029 	struct iovec aiov;
1030 	struct sockaddr *sa = NULL;
1031 	int error, fromlen;
1032 	int flags;
1033 
1034 	if (uap->from && uap->fromlenaddr) {
1035 		error = copyin(uap->fromlenaddr, &fromlen, sizeof(fromlen));
1036 		if (error)
1037 			return (error);
1038 		if (fromlen < 0)
1039 			return (EINVAL);
1040 	} else {
1041 		fromlen = 0;
1042 	}
1043 	aiov.iov_base = uap->buf;
1044 	aiov.iov_len = uap->len;
1045 	auio.uio_iov = &aiov;
1046 	auio.uio_iovcnt = 1;
1047 	auio.uio_offset = 0;
1048 	auio.uio_resid = uap->len;
1049 	auio.uio_segflg = UIO_USERSPACE;
1050 	auio.uio_rw = UIO_READ;
1051 	auio.uio_td = td;
1052 	flags = uap->flags;
1053 
1054 	error = kern_recvmsg(uap->s, uap->from ? &sa : NULL, &auio, NULL,
1055 			     &flags, &sysmsg->sysmsg_szresult);
1056 
1057 	if (error == 0 && uap->from) {
1058 		/* note: sa may still be NULL */
1059 		if (sa) {
1060 			fromlen = MIN(fromlen, sa->sa_len);
1061 			prison_local_ip(curthread, sa);
1062 			error = copyout(sa, uap->from, fromlen);
1063 		} else {
1064 			fromlen = 0;
1065 		}
1066 		if (error == 0) {
1067 			error = copyout(&fromlen, uap->fromlenaddr,
1068 					sizeof(fromlen));
1069 		}
1070 	}
1071 	if (sa)
1072 		kfree(sa, M_SONAME);
1073 
1074 	return (error);
1075 }
1076 
1077 /*
1078  * recvmsg_args(int s, struct msghdr *msg, int flags)
1079  *
1080  * MPALMOSTSAFE
1081  */
1082 int
1083 sys_recvmsg(struct sysmsg *sysmsg, const struct recvmsg_args *uap)
1084 {
1085 	struct thread *td = curthread;
1086 	struct msghdr msg;
1087 	struct uio auio;
1088 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
1089 	struct mbuf *m, *control = NULL;
1090 	struct sockaddr *sa = NULL;
1091 	caddr_t ctlbuf;
1092 	socklen_t *ufromlenp, *ucontrollenp;
1093 	int error, fromlen, controllen, len, flags, *uflagsp;
1094 
1095 	/*
1096 	 * This copyin handles everything except the iovec.
1097 	 */
1098 	error = copyin(uap->msg, &msg, sizeof(msg));
1099 	if (error)
1100 		return (error);
1101 
1102 	if (msg.msg_name && msg.msg_namelen < 0)
1103 		return (EINVAL);
1104 	if (msg.msg_control && msg.msg_controllen < 0)
1105 		return (EINVAL);
1106 
1107 	ufromlenp = (socklen_t *)((caddr_t)uap->msg + offsetof(struct msghdr,
1108 		    msg_namelen));
1109 	ucontrollenp = (socklen_t *)((caddr_t)uap->msg + offsetof(struct msghdr,
1110 		       msg_controllen));
1111 	uflagsp = (int *)((caddr_t)uap->msg + offsetof(struct msghdr,
1112 							msg_flags));
1113 
1114 	/*
1115 	 * Populate auio.
1116 	 */
1117 	error = iovec_copyin(msg.msg_iov, &iov, aiov, msg.msg_iovlen,
1118 			     &auio.uio_resid);
1119 	if (error)
1120 		return (error);
1121 	auio.uio_iov = iov;
1122 	auio.uio_iovcnt = msg.msg_iovlen;
1123 	auio.uio_offset = 0;
1124 	auio.uio_segflg = UIO_USERSPACE;
1125 	auio.uio_rw = UIO_READ;
1126 	auio.uio_td = td;
1127 
1128 	flags = uap->flags;
1129 
1130 	error = kern_recvmsg(uap->s,
1131 			     (msg.msg_name ? &sa : NULL), &auio,
1132 			     (msg.msg_control ? &control : NULL), &flags,
1133 			     &sysmsg->sysmsg_szresult);
1134 
1135 	/*
1136 	 * Conditionally copyout the name and populate the namelen field.
1137 	 */
1138 	if (error == 0 && msg.msg_name) {
1139 		/* note: sa may still be NULL */
1140 		if (sa != NULL) {
1141 			fromlen = MIN(msg.msg_namelen, sa->sa_len);
1142 			prison_local_ip(curthread, sa);
1143 			error = copyout(sa, msg.msg_name, fromlen);
1144 		} else {
1145 			fromlen = 0;
1146 		}
1147 		if (error == 0)
1148 			error = copyout(&fromlen, ufromlenp,
1149 			    sizeof(*ufromlenp));
1150 	}
1151 
1152 	/*
1153 	 * Copyout msg.msg_control and msg.msg_controllen.
1154 	 */
1155 	if (error == 0 && msg.msg_control) {
1156 		len = msg.msg_controllen;
1157 		m = control;
1158 		ctlbuf = (caddr_t)msg.msg_control;
1159 
1160 		while(m && len > 0) {
1161 			unsigned int tocopy;
1162 
1163 			if (len >= m->m_len) {
1164 				tocopy = m->m_len;
1165 			} else {
1166 				msg.msg_flags |= MSG_CTRUNC;
1167 				tocopy = len;
1168 			}
1169 
1170 			error = copyout(mtod(m, caddr_t), ctlbuf, tocopy);
1171 			if (error)
1172 				goto cleanup;
1173 
1174 			ctlbuf += tocopy;
1175 			len -= tocopy;
1176 			m = m->m_next;
1177 		}
1178 		controllen = ctlbuf - (caddr_t)msg.msg_control;
1179 		error = copyout(&controllen, ucontrollenp,
1180 		    sizeof(*ucontrollenp));
1181 	}
1182 
1183 	if (error == 0)
1184 		error = copyout(&flags, uflagsp, sizeof(*uflagsp));
1185 
1186 cleanup:
1187 	if (sa)
1188 		kfree(sa, M_SONAME);
1189 	iovec_free(&iov, aiov);
1190 	if (control)
1191 		m_freem(control);
1192 	return (error);
1193 }
1194 
1195 /*
1196  * If sopt->sopt_td == NULL, then sopt->sopt_val is treated as an
1197  * in kernel pointer instead of a userland pointer.  This allows us
1198  * to manipulate socket options in the emulation code.
1199  */
1200 int
1201 kern_setsockopt(int s, struct sockopt *sopt)
1202 {
1203 	struct thread *td = curthread;
1204 	struct file *fp;
1205 	int error;
1206 
1207 	if (sopt->sopt_val == NULL && sopt->sopt_valsize != 0)
1208 		return (EFAULT);
1209 	if (sopt->sopt_val != NULL && sopt->sopt_valsize == 0)
1210 		return (EINVAL);
1211 	if (sopt->sopt_valsize > SOMAXOPT_SIZE)	/* unsigned */
1212 		return (EINVAL);
1213 
1214 	error = holdsock(td, s, &fp);
1215 	if (error)
1216 		return (error);
1217 
1218 	error = sosetopt((struct socket *)fp->f_data, sopt);
1219 	dropfp(td, s, fp);
1220 
1221 	return (error);
1222 }
1223 
1224 /*
1225  * setsockopt_args(int s, int level, int name, caddr_t val, int valsize)
1226  *
1227  * MPALMOSTSAFE
1228  */
1229 int
1230 sys_setsockopt(struct sysmsg *sysmsg, const struct setsockopt_args *uap)
1231 {
1232 	struct thread *td = curthread;
1233 	struct sockopt sopt;
1234 	int error;
1235 
1236 	sopt.sopt_level = uap->level;
1237 	sopt.sopt_name = uap->name;
1238 	sopt.sopt_valsize = uap->valsize;
1239 	sopt.sopt_td = td;
1240 	sopt.sopt_val = NULL;
1241 
1242 	if (sopt.sopt_valsize > SOMAXOPT_SIZE) /* unsigned */
1243 		return (EINVAL);
1244 	if (uap->val) {
1245 		sopt.sopt_val = kmalloc(sopt.sopt_valsize, M_TEMP, M_WAITOK);
1246 		error = copyin(uap->val, sopt.sopt_val, sopt.sopt_valsize);
1247 		if (error)
1248 			goto out;
1249 	}
1250 
1251 	error = kern_setsockopt(uap->s, &sopt);
1252 out:
1253 	if (uap->val)
1254 		kfree(sopt.sopt_val, M_TEMP);
1255 	return(error);
1256 }
1257 
1258 /*
1259  * If sopt->sopt_td == NULL, then sopt->sopt_val is treated as an
1260  * in kernel pointer instead of a userland pointer.  This allows us
1261  * to manipulate socket options in the emulation code.
1262  */
1263 int
1264 kern_getsockopt(int s, struct sockopt *sopt)
1265 {
1266 	struct thread *td = curthread;
1267 	struct file *fp;
1268 	int error;
1269 
1270 	if (sopt->sopt_val == NULL && sopt->sopt_valsize != 0)
1271 		return (EFAULT);
1272 	if (sopt->sopt_val != NULL && sopt->sopt_valsize == 0)
1273 		return (EINVAL);
1274 
1275 	error = holdsock(td, s, &fp);
1276 	if (error)
1277 		return (error);
1278 
1279 	error = sogetopt((struct socket *)fp->f_data, sopt);
1280 	dropfp(td, s, fp);
1281 
1282 	return (error);
1283 }
1284 
1285 /*
1286  * getsockopt_args(int s, int level, int name, caddr_t val, int *avalsize)
1287  *
1288  * MPALMOSTSAFE
1289  */
1290 int
1291 sys_getsockopt(struct sysmsg *sysmsg, const struct getsockopt_args *uap)
1292 {
1293 	struct thread *td = curthread;
1294 	struct sockopt sopt;
1295 	int error, valsize, valszmax, mflag = 0;
1296 
1297 	if (uap->val) {
1298 		error = copyin(uap->avalsize, &valsize, sizeof(valsize));
1299 		if (error)
1300 			return (error);
1301 	} else {
1302 		valsize = 0;
1303 	}
1304 
1305 	sopt.sopt_level = uap->level;
1306 	sopt.sopt_name = uap->name;
1307 	sopt.sopt_valsize = valsize;
1308 	sopt.sopt_td = td;
1309 	sopt.sopt_val = NULL;
1310 
1311 	if (td->td_proc->p_ucred->cr_uid == 0) {
1312 		valszmax = SOMAXOPT_SIZE0;
1313 		mflag = M_NULLOK;
1314 	} else {
1315 		valszmax = SOMAXOPT_SIZE;
1316 	}
1317 	if (sopt.sopt_valsize > valszmax) /* unsigned */
1318 		return (EINVAL);
1319 	if (uap->val) {
1320 		sopt.sopt_val = kmalloc(sopt.sopt_valsize, M_TEMP,
1321 		    M_WAITOK | mflag);
1322 		if (sopt.sopt_val == NULL)
1323 			return (ENOBUFS);
1324 		error = copyin(uap->val, sopt.sopt_val, sopt.sopt_valsize);
1325 		if (error)
1326 			goto out;
1327 	}
1328 
1329 	error = kern_getsockopt(uap->s, &sopt);
1330 	if (error)
1331 		goto out;
1332 	valsize = sopt.sopt_valsize;
1333 	error = copyout(&valsize, uap->avalsize, sizeof(valsize));
1334 	if (error)
1335 		goto out;
1336 	if (uap->val)
1337 		error = copyout(sopt.sopt_val, uap->val, sopt.sopt_valsize);
1338 out:
1339 	if (uap->val)
1340 		kfree(sopt.sopt_val, M_TEMP);
1341 	return (error);
1342 }
1343 
1344 /*
1345  * The second argument to kern_getsockname() is a handle to a struct sockaddr.
1346  * This allows kern_getsockname() to return a pointer to an allocated struct
1347  * sockaddr which must be freed later with FREE().  The caller must
1348  * initialize *name to NULL.
1349  */
1350 int
1351 kern_getsockname(int s, struct sockaddr **name, int *namelen)
1352 {
1353 	struct thread *td = curthread;
1354 	struct file *fp;
1355 	struct socket *so;
1356 	struct sockaddr *sa = NULL;
1357 	int error;
1358 
1359 	error = holdsock(td, s, &fp);
1360 	if (error)
1361 		return (error);
1362 	if (*namelen < 0) {
1363 		fdrop(fp);
1364 		return (EINVAL);
1365 	}
1366 	so = (struct socket *)fp->f_data;
1367 	error = so_pru_sockaddr(so, &sa);
1368 	if (error == 0) {
1369 		if (sa == NULL) {
1370 			*namelen = 0;
1371 		} else {
1372 			*namelen = MIN(*namelen, sa->sa_len);
1373 			*name = sa;
1374 		}
1375 	}
1376 	dropfp(td, s, fp);
1377 
1378 	return (error);
1379 }
1380 
1381 /*
1382  * getsockname_args(int fdes, caddr_t asa, int *alen)
1383  *
1384  * Get socket name.
1385  *
1386  * MPALMOSTSAFE
1387  */
1388 int
1389 sys_getsockname(struct sysmsg *sysmsg, const struct getsockname_args *uap)
1390 {
1391 	struct sockaddr *sa = NULL;
1392 	struct sockaddr satmp;
1393 	int error, sa_len_in, sa_len_out;
1394 
1395 	error = copyin(uap->alen, &sa_len_in, sizeof(sa_len_in));
1396 	if (error)
1397 		return (error);
1398 
1399 	sa_len_out = sa_len_in;
1400 	error = kern_getsockname(uap->fdes, &sa, &sa_len_out);
1401 
1402 	if (error == 0) {
1403 		if (sa) {
1404 			prison_local_ip(curthread, sa);
1405 			error = copyout(sa, uap->asa, sa_len_out);
1406 		} else {
1407 			/*
1408 			 * unnamed uipc sockets don't bother storing
1409 			 * sockaddr, simulate an AF_LOCAL sockaddr.
1410 			 */
1411 			sa_len_out = sizeof(satmp);
1412 			if (sa_len_out > sa_len_in)
1413 				sa_len_out = sa_len_in;
1414 			if (sa_len_out < 0)
1415 				sa_len_out = 0;
1416 			bzero(&satmp, sizeof(satmp));
1417 			satmp.sa_len = sa_len_out;
1418 			satmp.sa_family = AF_LOCAL;
1419 			error = copyout(&satmp, uap->asa, sa_len_out);
1420 		}
1421 	}
1422 	if (error == 0 && sa_len_out != sa_len_in)
1423 		error = copyout(&sa_len_out, uap->alen, sizeof(*uap->alen));
1424 	if (sa)
1425 		kfree(sa, M_SONAME);
1426 	return (error);
1427 }
1428 
1429 /*
1430  * The second argument to kern_getpeername() is a handle to a struct sockaddr.
1431  * This allows kern_getpeername() to return a pointer to an allocated struct
1432  * sockaddr which must be freed later with FREE().  The caller must
1433  * initialize *name to NULL.
1434  */
1435 int
1436 kern_getpeername(int s, struct sockaddr **name, int *namelen)
1437 {
1438 	struct thread *td = curthread;
1439 	struct file *fp;
1440 	struct socket *so;
1441 	struct sockaddr *sa = NULL;
1442 	int error;
1443 
1444 	error = holdsock(td, s, &fp);
1445 	if (error)
1446 		return (error);
1447 	if (*namelen < 0) {
1448 		fdrop(fp);
1449 		return (EINVAL);
1450 	}
1451 	so = (struct socket *)fp->f_data;
1452 	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
1453 		fdrop(fp);
1454 		return (ENOTCONN);
1455 	}
1456 	error = so_pru_peeraddr(so, &sa);
1457 	if (error == 0) {
1458 		if (sa == NULL) {
1459 			*namelen = 0;
1460 		} else {
1461 			*namelen = MIN(*namelen, sa->sa_len);
1462 			*name = sa;
1463 		}
1464 	}
1465 	dropfp(td, s, fp);
1466 
1467 	return (error);
1468 }
1469 
1470 /*
1471  * getpeername_args(int fdes, caddr_t asa, int *alen)
1472  *
1473  * Get name of peer for connected socket.
1474  *
1475  * MPALMOSTSAFE
1476  */
1477 int
1478 sys_getpeername(struct sysmsg *sysmsg, const struct getpeername_args *uap)
1479 {
1480 	struct sockaddr *sa = NULL;
1481 	int error, sa_len;
1482 
1483 	error = copyin(uap->alen, &sa_len, sizeof(sa_len));
1484 	if (error)
1485 		return (error);
1486 
1487 	error = kern_getpeername(uap->fdes, &sa, &sa_len);
1488 
1489 	if (error == 0) {
1490 		prison_local_ip(curthread, sa);
1491 		error = copyout(sa, uap->asa, sa_len);
1492 	}
1493 	if (error == 0)
1494 		error = copyout(&sa_len, uap->alen, sizeof(*uap->alen));
1495 	if (sa)
1496 		kfree(sa, M_SONAME);
1497 	return (error);
1498 }
1499 
1500 int
1501 getsockaddr(struct sockaddr **namp, caddr_t uaddr, size_t len)
1502 {
1503 	struct sockaddr *sa;
1504 	int error;
1505 
1506 	*namp = NULL;
1507 	if (len > SOCK_MAXADDRLEN)
1508 		return ENAMETOOLONG;
1509 	if (len < offsetof(struct sockaddr, sa_data[0]))
1510 		return EDOM;
1511 	sa = kmalloc(len, M_SONAME, M_WAITOK);
1512 	error = copyin(uaddr, sa, len);
1513 	if (error) {
1514 		kfree(sa, M_SONAME);
1515 	} else {
1516 		sa->sa_len = len;
1517 		*namp = sa;
1518 	}
1519 	return error;
1520 }
1521 
1522 /*
1523  * Detach a mapped page and release resources back to the system.
1524  * We must release our wiring and if the object is ripped out
1525  * from under the vm_page we become responsible for freeing the
1526  * page.
1527  *
1528  * MPSAFE
1529  */
1530 static void
1531 sf_buf_mfree(void *arg)
1532 {
1533 	struct sf_buf *sf = arg;
1534 	vm_page_t m;
1535 
1536 	m = sf_buf_page(sf);
1537 	if (sf_buf_free(sf)) {
1538 		/* sf invalid now */
1539 		vm_page_sbusy_drop(m);
1540 #if 0
1541 		if (m->object == NULL &&
1542 		    m->wire_count == 0 &&
1543 		    (m->flags & PG_NEED_COMMIT) == 0) {
1544 			vm_page_free(m);
1545 		} else {
1546 			vm_page_wakeup(m);
1547 		}
1548 #endif
1549 	}
1550 }
1551 
1552 /*
1553  * sendfile(2).
1554  * int sendfile(int fd, int s, off_t offset, size_t nbytes,
1555  *	 struct sf_hdtr *hdtr, off_t *sbytes, int flags)
1556  *
1557  * Send a file specified by 'fd' and starting at 'offset' to a socket
1558  * specified by 's'. Send only 'nbytes' of the file or until EOF if
1559  * nbytes == 0. Optionally add a header and/or trailer to the socket
1560  * output. If specified, write the total number of bytes sent into *sbytes.
1561  *
1562  * In FreeBSD kern/uipc_syscalls.c,v 1.103, a bug was fixed that caused
1563  * the headers to count against the remaining bytes to be sent from
1564  * the file descriptor.  We may wish to implement a compatibility syscall
1565  * in the future.
1566  *
1567  * MPALMOSTSAFE
1568  */
1569 int
1570 sys_sendfile(struct sysmsg *sysmsg, const struct sendfile_args *uap)
1571 {
1572 	struct thread *td = curthread;
1573 	struct file *fp;
1574 	struct vnode *vp = NULL;
1575 	struct sf_hdtr hdtr;
1576 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
1577 	struct uio auio;
1578 	struct mbuf *mheader = NULL;
1579 	size_t hbytes = 0;
1580 	size_t tbytes;
1581 	off_t hdtr_size = 0;
1582 	off_t sbytes;
1583 	int error;
1584 
1585 	/*
1586 	 * Do argument checking. Must be a regular file in, stream
1587 	 * type and connected socket out, positive offset.
1588 	 */
1589 	fp = holdfp(td, uap->fd, FREAD);
1590 	if (fp == NULL) {
1591 		return (EBADF);
1592 	}
1593 	if (fp->f_type != DTYPE_VNODE) {
1594 		fdrop(fp);
1595 		return (EINVAL);
1596 	}
1597 	vp = (struct vnode *)fp->f_data;
1598 	vref(vp);
1599 	dropfp(td, uap->fd, fp);
1600 
1601 	/*
1602 	 * If specified, get the pointer to the sf_hdtr struct for
1603 	 * any headers/trailers.
1604 	 */
1605 	if (uap->hdtr) {
1606 		error = copyin(uap->hdtr, &hdtr, sizeof(hdtr));
1607 		if (error)
1608 			goto done;
1609 		/*
1610 		 * Send any headers.
1611 		 */
1612 		if (hdtr.headers) {
1613 			error = iovec_copyin(hdtr.headers, &iov, aiov,
1614 					     hdtr.hdr_cnt, &hbytes);
1615 			if (error)
1616 				goto done;
1617 			auio.uio_iov = iov;
1618 			auio.uio_iovcnt = hdtr.hdr_cnt;
1619 			auio.uio_offset = 0;
1620 			auio.uio_segflg = UIO_USERSPACE;
1621 			auio.uio_rw = UIO_WRITE;
1622 			auio.uio_td = td;
1623 			auio.uio_resid = hbytes;
1624 
1625 			mheader = m_uiomove(&auio);
1626 
1627 			iovec_free(&iov, aiov);
1628 			if (mheader == NULL)
1629 				goto done;
1630 		}
1631 	}
1632 
1633 	error = kern_sendfile(vp, uap->s, uap->offset, uap->nbytes, mheader,
1634 			      &sbytes, uap->flags);
1635 	if (error)
1636 		goto done;
1637 
1638 	/*
1639 	 * Send trailers. Wimp out and use writev(2).
1640 	 */
1641 	if (uap->hdtr != NULL && hdtr.trailers != NULL) {
1642 		error = iovec_copyin(hdtr.trailers, &iov, aiov,
1643 				     hdtr.trl_cnt, &auio.uio_resid);
1644 		if (error)
1645 			goto done;
1646 		auio.uio_iov = iov;
1647 		auio.uio_iovcnt = hdtr.trl_cnt;
1648 		auio.uio_offset = 0;
1649 		auio.uio_segflg = UIO_USERSPACE;
1650 		auio.uio_rw = UIO_WRITE;
1651 		auio.uio_td = td;
1652 
1653 		tbytes = 0;	/* avoid gcc warnings */
1654 		error = kern_sendmsg(uap->s, NULL, &auio, NULL, 0, &tbytes);
1655 
1656 		iovec_free(&iov, aiov);
1657 		if (error)
1658 			goto done;
1659 		hdtr_size += tbytes;	/* trailer bytes successfully sent */
1660 	}
1661 
1662 done:
1663 	if (vp)
1664 		vrele(vp);
1665 	if (uap->sbytes != NULL) {
1666 		sbytes += hdtr_size;
1667 		copyout(&sbytes, uap->sbytes, sizeof(off_t));
1668 	}
1669 	return (error);
1670 }
1671 
1672 int
1673 kern_sendfile(struct vnode *vp, int sfd, off_t offset, size_t nbytes,
1674 	      struct mbuf *mheader, off_t *sbytes, int flags)
1675 {
1676 	struct thread *td = curthread;
1677 	struct vm_object *obj;
1678 	struct socket *so;
1679 	struct file *fp;
1680 	struct mbuf *m, *mp;
1681 	struct sf_buf *sf;
1682 	struct vm_page *pg;
1683 	off_t off, xfsize, xbytes;
1684 	off_t hbytes = 0;
1685 	int error = 0;
1686 
1687 	if (vp->v_type != VREG) {
1688 		error = EINVAL;
1689 		goto done0;
1690 	}
1691 	if ((obj = vp->v_object) == NULL) {
1692 		error = EINVAL;
1693 		goto done0;
1694 	}
1695 	error = holdsock(td, sfd, &fp);
1696 	if (error)
1697 		goto done0;
1698 	so = (struct socket *)fp->f_data;
1699 	if (so->so_type != SOCK_STREAM) {
1700 		error = EINVAL;
1701 		goto done1;
1702 	}
1703 	if ((so->so_state & SS_ISCONNECTED) == 0) {
1704 		error = ENOTCONN;
1705 		goto done1;
1706 	}
1707 	if (offset < 0) {
1708 		error = EINVAL;
1709 		goto done1;
1710 	}
1711 
1712 	/*
1713 	 * preallocation is required for asynchronous passing of mbufs,
1714 	 * otherwise we can wind up building up an infinite number of
1715 	 * mbufs during the asynchronous latency.
1716 	 */
1717 	if ((so->so_snd.ssb_flags & (SSB_PREALLOC | SSB_STOPSUPP)) == 0) {
1718 		error = EINVAL;
1719 		goto done1;
1720 	}
1721 
1722 	*sbytes = 0;
1723 	xbytes = 0;
1724 
1725 	/*
1726 	 * Protect against multiple writers to the socket.
1727 	 * We need at least a shared lock on the VM object
1728 	 */
1729 	ssb_lock(&so->so_snd, M_WAITOK);
1730 	vm_object_hold_shared(obj);
1731 
1732 	/*
1733 	 * Loop through the pages in the file, starting with the requested
1734 	 * offset. Get a file page (do I/O if necessary), map the file page
1735 	 * into an sf_buf, attach an mbuf header to the sf_buf, and queue
1736 	 * it on the socket.
1737 	 */
1738 	for (off = offset; ;
1739 	     off += xfsize, *sbytes += xfsize + hbytes, xbytes += xfsize) {
1740 		vm_pindex_t pindex;
1741 		vm_offset_t pgoff;
1742 		long space;
1743 		int loops;
1744 
1745 		pindex = OFF_TO_IDX(off);
1746 		loops = 0;
1747 
1748 retry_lookup:
1749 		/*
1750 		 * Calculate the amount to transfer. Not to exceed a page,
1751 		 * the EOF, or the passed in nbytes.
1752 		 */
1753 		xfsize = vp->v_filesize - off;
1754 		if (xfsize > PAGE_SIZE)
1755 			xfsize = PAGE_SIZE;
1756 		pgoff = (vm_offset_t)(off & PAGE_MASK);
1757 		if (PAGE_SIZE - pgoff < xfsize)
1758 			xfsize = PAGE_SIZE - pgoff;
1759 		if (nbytes && xfsize > (nbytes - xbytes))
1760 			xfsize = nbytes - xbytes;
1761 		if (xfsize <= 0)
1762 			break;
1763 		/*
1764 		 * Optimize the non-blocking case by looking at the socket space
1765 		 * before going to the extra work of constituting the sf_buf.
1766 		 */
1767 		if (so->so_snd.ssb_flags & SSB_PREALLOC)
1768 			space = ssb_space_prealloc(&so->so_snd);
1769 		else
1770 			space = ssb_space(&so->so_snd);
1771 
1772 		if ((fp->f_flag & FNONBLOCK) && space <= 0) {
1773 			if (so->so_state & SS_CANTSENDMORE)
1774 				error = EPIPE;
1775 			else
1776 				error = EAGAIN;
1777 			goto done;
1778 		}
1779 
1780 		/*
1781 		 * Attempt to look up the page.
1782 		 *
1783 		 * Try to find the data using a shared vm_object token and
1784 		 * vm_page_lookup_sbusy_try() first.
1785 		 *
1786 		 * If data is missing, use a UIO_NOCOPY VOP_READ to load
1787 		 * the missing data and loop back up.  We avoid all sorts
1788 		 * of problems by not trying to hold onto the page during
1789 		 * the I/O.
1790 		 *
1791 		 * NOTE: The soft-busy will temporary block filesystem
1792 		 *	 truncation operations when a file is removed
1793 		 *	 while the sendfile is running.
1794 		 */
1795 		pg = vm_page_lookup_sbusy_try(obj, pindex, pgoff, xfsize);
1796 		if (pg == NULL) {
1797 			struct uio auio;
1798 			struct iovec aiov;
1799 			int bsize;
1800 
1801 			if (++loops > 100000) {
1802 				kprintf("sendfile: VOP operation failed "
1803 					"to retain page\n");
1804 				error = EIO;
1805 				goto done;
1806 			}
1807 
1808 			vm_object_drop(obj);
1809 			bsize = vp->v_mount->mnt_stat.f_iosize;
1810 			auio.uio_iov = &aiov;
1811 			auio.uio_iovcnt = 1;
1812 			aiov.iov_base = 0;
1813 			aiov.iov_len = MAXBSIZE;
1814 			auio.uio_resid = MAXBSIZE;
1815 			auio.uio_offset = trunc_page(off);
1816 			auio.uio_segflg = UIO_NOCOPY;
1817 			auio.uio_rw = UIO_READ;
1818 			auio.uio_td = td;
1819 
1820 			vn_lock(vp, LK_SHARED | LK_RETRY);
1821 			error = VOP_READ_FP(vp, &auio,
1822 					 IO_VMIO | ((MAXBSIZE / bsize) << 16),
1823 					 td->td_ucred, fp);
1824 			vn_unlock(vp);
1825 			vm_object_hold_shared(obj);
1826 
1827 			if (error)
1828 				goto done;
1829 			goto retry_lookup;
1830 		}
1831 
1832 		/*
1833 		 * Get a sendfile buf. We usually wait as long as necessary,
1834 		 * but this wait can be interrupted.
1835 		 */
1836 		if ((sf = sf_buf_alloc(pg)) == NULL) {
1837 			vm_page_sbusy_drop(pg);
1838 			/* vm_page_try_to_free(pg); */
1839 			error = EINTR;
1840 			goto done;
1841 		}
1842 
1843 		/*
1844 		 * Get an mbuf header and set it up as having external storage.
1845 		 */
1846 		MGETHDR(m, M_WAITOK, MT_DATA);
1847 		if (m == NULL) {
1848 			error = ENOBUFS;
1849 			vm_page_sbusy_drop(pg);
1850 			/* vm_page_try_to_free(pg); */
1851 			sf_buf_free(sf);
1852 			goto done;
1853 		}
1854 
1855 		m->m_ext.ext_free = sf_buf_mfree;
1856 		m->m_ext.ext_ref = sf_buf_ref;
1857 		m->m_ext.ext_arg = sf;
1858 		m->m_ext.ext_buf = (void *)sf_buf_kva(sf);
1859 		m->m_ext.ext_size = PAGE_SIZE;
1860 		m->m_data = (char *)sf_buf_kva(sf) + pgoff;
1861 		m->m_flags |= M_EXT;
1862 		m->m_pkthdr.len = m->m_len = xfsize;
1863 		KKASSERT((m->m_flags & (M_EXT_CLUSTER)) == 0);
1864 
1865 		if (mheader != NULL) {
1866 			hbytes = mheader->m_pkthdr.len;
1867 			mheader->m_pkthdr.len += m->m_pkthdr.len;
1868 			m_cat(mheader, m);
1869 			m = mheader;
1870 			mheader = NULL;
1871 		} else {
1872 			hbytes = 0;
1873 		}
1874 
1875 		/*
1876 		 * Add the buffer to the socket buffer chain.
1877 		 */
1878 		crit_enter();
1879 retry_space:
1880 		/*
1881 		 * Make sure that the socket is still able to take more data.
1882 		 * CANTSENDMORE being true usually means that the connection
1883 		 * was closed. so_error is true when an error was sensed after
1884 		 * a previous send.
1885 		 * The state is checked after the page mapping and buffer
1886 		 * allocation above since those operations may block and make
1887 		 * any socket checks stale. From this point forward, nothing
1888 		 * blocks before the pru_send (or more accurately, any blocking
1889 		 * results in a loop back to here to re-check).
1890 		 */
1891 		if ((so->so_state & SS_CANTSENDMORE) || so->so_error) {
1892 			if (so->so_state & SS_CANTSENDMORE) {
1893 				error = EPIPE;
1894 			} else {
1895 				error = so->so_error;
1896 				so->so_error = 0;
1897 			}
1898 			m_freem(m);
1899 			crit_exit();
1900 			goto done;
1901 		}
1902 		/*
1903 		 * Wait for socket space to become available. We do this just
1904 		 * after checking the connection state above in order to avoid
1905 		 * a race condition with ssb_wait().
1906 		 */
1907 		if (so->so_snd.ssb_flags & SSB_PREALLOC)
1908 			space = ssb_space_prealloc(&so->so_snd);
1909 		else
1910 			space = ssb_space(&so->so_snd);
1911 
1912 		if (space < m->m_pkthdr.len && space < so->so_snd.ssb_lowat) {
1913 			if (fp->f_flag & FNONBLOCK) {
1914 				m_freem(m);
1915 				crit_exit();
1916 				error = EAGAIN;
1917 				goto done;
1918 			}
1919 			error = ssb_wait(&so->so_snd);
1920 			/*
1921 			 * An error from ssb_wait usually indicates that we've
1922 			 * been interrupted by a signal. If we've sent anything
1923 			 * then return bytes sent, otherwise return the error.
1924 			 */
1925 			if (error) {
1926 				m_freem(m);
1927 				crit_exit();
1928 				goto done;
1929 			}
1930 			goto retry_space;
1931 		}
1932 
1933 		if (so->so_snd.ssb_flags & SSB_PREALLOC) {
1934 			for (mp = m; mp != NULL; mp = mp->m_next)
1935 				ssb_preallocstream(&so->so_snd, mp);
1936 		}
1937 		if (use_sendfile_async)
1938 			error = so_pru_senda(so, 0, m, NULL, NULL, td);
1939 		else
1940 			error = so_pru_send(so, 0, m, NULL, NULL, td);
1941 
1942 		crit_exit();
1943 		if (error)
1944 			goto done;
1945 	}
1946 	if (mheader != NULL) {
1947 		*sbytes += mheader->m_pkthdr.len;
1948 
1949 		if (so->so_snd.ssb_flags & SSB_PREALLOC) {
1950 			for (mp = mheader; mp != NULL; mp = mp->m_next)
1951 				ssb_preallocstream(&so->so_snd, mp);
1952 		}
1953 		if (use_sendfile_async)
1954 			error = so_pru_senda(so, 0, mheader, NULL, NULL, td);
1955 		else
1956 			error = so_pru_send(so, 0, mheader, NULL, NULL, td);
1957 
1958 		mheader = NULL;
1959 	}
1960 done:
1961 	vm_object_drop(obj);
1962 	ssb_unlock(&so->so_snd);
1963 done1:
1964 	dropfp(td, sfd, fp);
1965 done0:
1966 	if (mheader != NULL)
1967 		m_freem(mheader);
1968 	return (error);
1969 }
1970