xref: /dragonfly/sys/kern/uipc_syscalls.c (revision 16fb0422)
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. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)uipc_syscalls.c	8.4 (Berkeley) 2/21/94
37  * $FreeBSD: src/sys/kern/uipc_syscalls.c,v 1.65.2.17 2003/04/04 17:11:16 tegge Exp $
38  */
39 
40 #include "opt_ktrace.h"
41 #include "opt_sctp.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/sysproto.h>
47 #include <sys/malloc.h>
48 #include <sys/filedesc.h>
49 #include <sys/event.h>
50 #include <sys/proc.h>
51 #include <sys/fcntl.h>
52 #include <sys/file.h>
53 #include <sys/filio.h>
54 #include <sys/kern_syscall.h>
55 #include <sys/mbuf.h>
56 #include <sys/protosw.h>
57 #include <sys/sfbuf.h>
58 #include <sys/socket.h>
59 #include <sys/socketvar.h>
60 #include <sys/socketops.h>
61 #include <sys/uio.h>
62 #include <sys/vnode.h>
63 #include <sys/lock.h>
64 #include <sys/mount.h>
65 #ifdef KTRACE
66 #include <sys/ktrace.h>
67 #endif
68 #include <vm/vm.h>
69 #include <vm/vm_object.h>
70 #include <vm/vm_page.h>
71 #include <vm/vm_pageout.h>
72 #include <vm/vm_kern.h>
73 #include <vm/vm_extern.h>
74 #include <sys/file2.h>
75 #include <sys/signalvar.h>
76 #include <sys/serialize.h>
77 
78 #include <sys/thread2.h>
79 #include <sys/msgport2.h>
80 #include <sys/socketvar2.h>
81 #include <net/netmsg2.h>
82 
83 #ifdef SCTP
84 #include <netinet/sctp_peeloff.h>
85 #endif /* SCTP */
86 
87 extern int use_soaccept_pred_fast;
88 
89 /*
90  * System call interface to the socket abstraction.
91  */
92 
93 extern	struct fileops socketops;
94 
95 /*
96  * socket_args(int domain, int type, int protocol)
97  */
98 int
99 kern_socket(int domain, int type, int protocol, int *res)
100 {
101 	struct thread *td = curthread;
102 	struct filedesc *fdp = td->td_proc->p_fd;
103 	struct socket *so;
104 	struct file *fp;
105 	int fd, error;
106 
107 	KKASSERT(td->td_lwp);
108 
109 	error = falloc(td->td_lwp, &fp, &fd);
110 	if (error)
111 		return (error);
112 	error = socreate(domain, &so, type, protocol, td);
113 	if (error) {
114 		fsetfd(fdp, NULL, fd);
115 	} else {
116 		fp->f_type = DTYPE_SOCKET;
117 		fp->f_flag = FREAD | FWRITE;
118 		fp->f_ops = &socketops;
119 		fp->f_data = so;
120 		*res = fd;
121 		fsetfd(fdp, fp, fd);
122 	}
123 	fdrop(fp);
124 	return (error);
125 }
126 
127 /*
128  * MPALMOSTSAFE
129  */
130 int
131 sys_socket(struct socket_args *uap)
132 {
133 	int error;
134 
135 	error = kern_socket(uap->domain, uap->type, uap->protocol,
136 			    &uap->sysmsg_iresult);
137 
138 	return (error);
139 }
140 
141 int
142 kern_bind(int s, struct sockaddr *sa)
143 {
144 	struct thread *td = curthread;
145 	struct proc *p = td->td_proc;
146 	struct file *fp;
147 	int error;
148 
149 	KKASSERT(p);
150 	error = holdsock(p->p_fd, s, &fp);
151 	if (error)
152 		return (error);
153 	error = sobind((struct socket *)fp->f_data, sa, td);
154 	fdrop(fp);
155 	return (error);
156 }
157 
158 /*
159  * bind_args(int s, caddr_t name, int namelen)
160  *
161  * MPALMOSTSAFE
162  */
163 int
164 sys_bind(struct bind_args *uap)
165 {
166 	struct sockaddr *sa;
167 	int error;
168 
169 	error = getsockaddr(&sa, uap->name, uap->namelen);
170 	if (error)
171 		return (error);
172 	error = kern_bind(uap->s, sa);
173 	kfree(sa, M_SONAME);
174 
175 	return (error);
176 }
177 
178 int
179 kern_listen(int s, int backlog)
180 {
181 	struct thread *td = curthread;
182 	struct proc *p = td->td_proc;
183 	struct file *fp;
184 	int error;
185 
186 	KKASSERT(p);
187 	error = holdsock(p->p_fd, s, &fp);
188 	if (error)
189 		return (error);
190 	error = solisten((struct socket *)fp->f_data, backlog, td);
191 	fdrop(fp);
192 	return(error);
193 }
194 
195 /*
196  * listen_args(int s, int backlog)
197  *
198  * MPALMOSTSAFE
199  */
200 int
201 sys_listen(struct listen_args *uap)
202 {
203 	int error;
204 
205 	error = kern_listen(uap->s, uap->backlog);
206 	return (error);
207 }
208 
209 /*
210  * Returns the accepted socket as well.
211  *
212  * NOTE!  The sockets sitting on so_comp/so_incomp might have 0 refs, the
213  *	  pool token is absolutely required to avoid a sofree() race,
214  *	  as well as to avoid tailq handling races.
215  */
216 static boolean_t
217 soaccept_predicate(struct netmsg_so_notify *msg)
218 {
219 	struct socket *head = msg->base.nm_so;
220 	struct socket *so;
221 
222 	if (head->so_error != 0) {
223 		msg->base.lmsg.ms_error = head->so_error;
224 		return (TRUE);
225 	}
226 	lwkt_getpooltoken(head);
227 	if (!TAILQ_EMPTY(&head->so_comp)) {
228 		/* Abuse nm_so field as copy in/copy out parameter. XXX JH */
229 		so = TAILQ_FIRST(&head->so_comp);
230 		TAILQ_REMOVE(&head->so_comp, so, so_list);
231 		head->so_qlen--;
232 		soclrstate(so, SS_COMP);
233 		so->so_head = NULL;
234 		soreference(so);
235 
236 		lwkt_relpooltoken(head);
237 
238 		msg->base.lmsg.ms_error = 0;
239 		msg->base.nm_so = so;
240 		return (TRUE);
241 	}
242 	lwkt_relpooltoken(head);
243 	if (head->so_state & SS_CANTRCVMORE) {
244 		msg->base.lmsg.ms_error = ECONNABORTED;
245 		return (TRUE);
246 	}
247 	if (msg->nm_fflags & FNONBLOCK) {
248 		msg->base.lmsg.ms_error = EWOULDBLOCK;
249 		return (TRUE);
250 	}
251 
252 	return (FALSE);
253 }
254 
255 /*
256  * The second argument to kern_accept() is a handle to a struct sockaddr.
257  * This allows kern_accept() to return a pointer to an allocated struct
258  * sockaddr which must be freed later with FREE().  The caller must
259  * initialize *name to NULL.
260  */
261 int
262 kern_accept(int s, int fflags, struct sockaddr **name, int *namelen, int *res)
263 {
264 	struct thread *td = curthread;
265 	struct filedesc *fdp = td->td_proc->p_fd;
266 	struct file *lfp = NULL;
267 	struct file *nfp = NULL;
268 	struct sockaddr *sa;
269 	struct socket *head, *so;
270 	struct netmsg_so_notify msg;
271 	int fd;
272 	u_int fflag;		/* type must match fp->f_flag */
273 	int error, tmp;
274 
275 	*res = -1;
276 	if (name && namelen && *namelen < 0)
277 		return (EINVAL);
278 
279 	error = holdsock(td->td_proc->p_fd, s, &lfp);
280 	if (error)
281 		return (error);
282 
283 	error = falloc(td->td_lwp, &nfp, &fd);
284 	if (error) {		/* Probably ran out of file descriptors. */
285 		fdrop(lfp);
286 		return (error);
287 	}
288 	head = (struct socket *)lfp->f_data;
289 	if ((head->so_options & SO_ACCEPTCONN) == 0) {
290 		error = EINVAL;
291 		goto done;
292 	}
293 
294 	if (fflags & O_FBLOCKING)
295 		fflags |= lfp->f_flag & ~FNONBLOCK;
296 	else if (fflags & O_FNONBLOCKING)
297 		fflags |= lfp->f_flag | FNONBLOCK;
298 	else
299 		fflags = lfp->f_flag;
300 
301 	if (use_soaccept_pred_fast) {
302 		boolean_t pred;
303 
304 		/* Initialize necessary parts for soaccept_predicate() */
305 		netmsg_init(&msg.base, head, &netisr_apanic_rport, 0, NULL);
306 		msg.nm_fflags = fflags;
307 
308 		lwkt_getpooltoken(head);
309 		pred = soaccept_predicate(&msg);
310 		lwkt_relpooltoken(head);
311 
312 		if (pred) {
313 			error = msg.base.lmsg.ms_error;
314 			if (error)
315 				goto done;
316 			else
317 				goto accepted;
318 		}
319 	}
320 
321 	/* optimize for uniprocessor case later XXX JH */
322 	netmsg_init_abortable(&msg.base, head, &curthread->td_msgport,
323 			      0, netmsg_so_notify, netmsg_so_notify_doabort);
324 	msg.nm_predicate = soaccept_predicate;
325 	msg.nm_fflags = fflags;
326 	msg.nm_etype = NM_REVENT;
327 	error = lwkt_domsg(head->so_port, &msg.base.lmsg, PCATCH);
328 	if (error)
329 		goto done;
330 
331 accepted:
332 	/*
333 	 * At this point we have the connection that's ready to be accepted.
334 	 *
335 	 * NOTE! soaccept_predicate() ref'd so for us, and soaccept() expects
336 	 * 	 to eat the ref and turn it into a descriptor.
337 	 */
338 	so = msg.base.nm_so;
339 
340 	fflag = lfp->f_flag;
341 
342 	/* connection has been removed from the listen queue */
343 	KNOTE(&head->so_rcv.ssb_kq.ki_note, 0);
344 
345 	if (head->so_sigio != NULL)
346 		fsetown(fgetown(&head->so_sigio), &so->so_sigio);
347 
348 	nfp->f_type = DTYPE_SOCKET;
349 	nfp->f_flag = fflag;
350 	nfp->f_ops = &socketops;
351 	nfp->f_data = so;
352 	/* Sync socket nonblocking/async state with file flags */
353 	tmp = fflag & FNONBLOCK;
354 	fo_ioctl(nfp, FIONBIO, (caddr_t)&tmp, td->td_ucred, NULL);
355 	tmp = fflag & FASYNC;
356 	fo_ioctl(nfp, FIOASYNC, (caddr_t)&tmp, td->td_ucred, NULL);
357 
358 	sa = NULL;
359 	if (so->so_faddr != NULL) {
360 		sa = so->so_faddr;
361 		so->so_faddr = NULL;
362 
363 		soaccept_generic(so);
364 		error = 0;
365 	} else {
366 		error = soaccept(so, &sa);
367 	}
368 
369 	/*
370 	 * Set the returned name and namelen as applicable.  Set the returned
371 	 * namelen to 0 for older code which might ignore the return value
372 	 * from accept.
373 	 */
374 	if (error == 0) {
375 		if (sa && name && namelen) {
376 			if (*namelen > sa->sa_len)
377 				*namelen = sa->sa_len;
378 			*name = sa;
379 		} else {
380 			if (sa)
381 				kfree(sa, M_SONAME);
382 		}
383 	}
384 
385 done:
386 	/*
387 	 * If an error occured clear the reserved descriptor, else associate
388 	 * nfp with it.
389 	 *
390 	 * Note that *res is normally ignored if an error is returned but
391 	 * a syscall message will still have access to the result code.
392 	 */
393 	if (error) {
394 		fsetfd(fdp, NULL, fd);
395 	} else {
396 		*res = fd;
397 		fsetfd(fdp, nfp, fd);
398 	}
399 	fdrop(nfp);
400 	fdrop(lfp);
401 	return (error);
402 }
403 
404 /*
405  * accept(int s, caddr_t name, int *anamelen)
406  *
407  * MPALMOSTSAFE
408  */
409 int
410 sys_accept(struct accept_args *uap)
411 {
412 	struct sockaddr *sa = NULL;
413 	int sa_len;
414 	int error;
415 
416 	if (uap->name) {
417 		error = copyin(uap->anamelen, &sa_len, sizeof(sa_len));
418 		if (error)
419 			return (error);
420 
421 		error = kern_accept(uap->s, 0, &sa, &sa_len,
422 				    &uap->sysmsg_iresult);
423 
424 		if (error == 0)
425 			error = copyout(sa, uap->name, sa_len);
426 		if (error == 0) {
427 			error = copyout(&sa_len, uap->anamelen,
428 			    sizeof(*uap->anamelen));
429 		}
430 		if (sa)
431 			kfree(sa, M_SONAME);
432 	} else {
433 		error = kern_accept(uap->s, 0, NULL, 0,
434 				    &uap->sysmsg_iresult);
435 	}
436 	return (error);
437 }
438 
439 /*
440  * extaccept(int s, int fflags, caddr_t name, int *anamelen)
441  *
442  * MPALMOSTSAFE
443  */
444 int
445 sys_extaccept(struct extaccept_args *uap)
446 {
447 	struct sockaddr *sa = NULL;
448 	int sa_len;
449 	int error;
450 	int fflags = uap->flags & O_FMASK;
451 
452 	if (uap->name) {
453 		error = copyin(uap->anamelen, &sa_len, sizeof(sa_len));
454 		if (error)
455 			return (error);
456 
457 		error = kern_accept(uap->s, fflags, &sa, &sa_len,
458 				    &uap->sysmsg_iresult);
459 
460 		if (error == 0)
461 			error = copyout(sa, uap->name, sa_len);
462 		if (error == 0) {
463 			error = copyout(&sa_len, uap->anamelen,
464 			    sizeof(*uap->anamelen));
465 		}
466 		if (sa)
467 			kfree(sa, M_SONAME);
468 	} else {
469 		error = kern_accept(uap->s, fflags, NULL, 0,
470 				    &uap->sysmsg_iresult);
471 	}
472 	return (error);
473 }
474 
475 
476 /*
477  * Returns TRUE if predicate satisfied.
478  */
479 static boolean_t
480 soconnected_predicate(struct netmsg_so_notify *msg)
481 {
482 	struct socket *so = msg->base.nm_so;
483 
484 	/* check predicate */
485 	if (!(so->so_state & SS_ISCONNECTING) || so->so_error != 0) {
486 		msg->base.lmsg.ms_error = so->so_error;
487 		return (TRUE);
488 	}
489 
490 	return (FALSE);
491 }
492 
493 int
494 kern_connect(int s, int fflags, struct sockaddr *sa)
495 {
496 	struct thread *td = curthread;
497 	struct proc *p = td->td_proc;
498 	struct file *fp;
499 	struct socket *so;
500 	int error, interrupted = 0;
501 
502 	error = holdsock(p->p_fd, s, &fp);
503 	if (error)
504 		return (error);
505 	so = (struct socket *)fp->f_data;
506 
507 	if (fflags & O_FBLOCKING)
508 		/* fflags &= ~FNONBLOCK; */;
509 	else if (fflags & O_FNONBLOCKING)
510 		fflags |= FNONBLOCK;
511 	else
512 		fflags = fp->f_flag;
513 
514 	if (so->so_state & SS_ISCONNECTING) {
515 		error = EALREADY;
516 		goto done;
517 	}
518 	error = soconnect(so, sa, td);
519 	if (error)
520 		goto bad;
521 	if ((fflags & FNONBLOCK) && (so->so_state & SS_ISCONNECTING)) {
522 		error = EINPROGRESS;
523 		goto done;
524 	}
525 	if ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
526 		struct netmsg_so_notify msg;
527 
528 		netmsg_init_abortable(&msg.base, so,
529 				      &curthread->td_msgport,
530 				      0,
531 				      netmsg_so_notify,
532 				      netmsg_so_notify_doabort);
533 		msg.nm_predicate = soconnected_predicate;
534 		msg.nm_etype = NM_REVENT;
535 		error = lwkt_domsg(so->so_port, &msg.base.lmsg, PCATCH);
536 		if (error == EINTR || error == ERESTART)
537 			interrupted = 1;
538 	}
539 	if (error == 0) {
540 		error = so->so_error;
541 		so->so_error = 0;
542 	}
543 bad:
544 	if (!interrupted)
545 		soclrstate(so, SS_ISCONNECTING);
546 	if (error == ERESTART)
547 		error = EINTR;
548 done:
549 	fdrop(fp);
550 	return (error);
551 }
552 
553 /*
554  * connect_args(int s, caddr_t name, int namelen)
555  *
556  * MPALMOSTSAFE
557  */
558 int
559 sys_connect(struct connect_args *uap)
560 {
561 	struct sockaddr *sa;
562 	int error;
563 
564 	error = getsockaddr(&sa, uap->name, uap->namelen);
565 	if (error)
566 		return (error);
567 	error = kern_connect(uap->s, 0, sa);
568 	kfree(sa, M_SONAME);
569 
570 	return (error);
571 }
572 
573 /*
574  * connect_args(int s, int fflags, caddr_t name, int namelen)
575  *
576  * MPALMOSTSAFE
577  */
578 int
579 sys_extconnect(struct extconnect_args *uap)
580 {
581 	struct sockaddr *sa;
582 	int error;
583 	int fflags = uap->flags & O_FMASK;
584 
585 	error = getsockaddr(&sa, uap->name, uap->namelen);
586 	if (error)
587 		return (error);
588 	error = kern_connect(uap->s, fflags, sa);
589 	kfree(sa, M_SONAME);
590 
591 	return (error);
592 }
593 
594 int
595 kern_socketpair(int domain, int type, int protocol, int *sv)
596 {
597 	struct thread *td = curthread;
598 	struct filedesc *fdp;
599 	struct file *fp1, *fp2;
600 	struct socket *so1, *so2;
601 	int fd1, fd2, error;
602 
603 	fdp = td->td_proc->p_fd;
604 	error = socreate(domain, &so1, type, protocol, td);
605 	if (error)
606 		return (error);
607 	error = socreate(domain, &so2, type, protocol, td);
608 	if (error)
609 		goto free1;
610 	error = falloc(td->td_lwp, &fp1, &fd1);
611 	if (error)
612 		goto free2;
613 	sv[0] = fd1;
614 	fp1->f_data = so1;
615 	error = falloc(td->td_lwp, &fp2, &fd2);
616 	if (error)
617 		goto free3;
618 	fp2->f_data = so2;
619 	sv[1] = fd2;
620 	error = soconnect2(so1, so2);
621 	if (error)
622 		goto free4;
623 	if (type == SOCK_DGRAM) {
624 		/*
625 		 * Datagram socket connection is asymmetric.
626 		 */
627 		 error = soconnect2(so2, so1);
628 		 if (error)
629 			goto free4;
630 	}
631 	fp1->f_type = fp2->f_type = DTYPE_SOCKET;
632 	fp1->f_flag = fp2->f_flag = FREAD|FWRITE;
633 	fp1->f_ops = fp2->f_ops = &socketops;
634 	fsetfd(fdp, fp1, fd1);
635 	fsetfd(fdp, fp2, fd2);
636 	fdrop(fp1);
637 	fdrop(fp2);
638 	return (error);
639 free4:
640 	fsetfd(fdp, NULL, fd2);
641 	fdrop(fp2);
642 free3:
643 	fsetfd(fdp, NULL, fd1);
644 	fdrop(fp1);
645 free2:
646 	(void)soclose(so2, 0);
647 free1:
648 	(void)soclose(so1, 0);
649 	return (error);
650 }
651 
652 /*
653  * socketpair(int domain, int type, int protocol, int *rsv)
654  */
655 int
656 sys_socketpair(struct socketpair_args *uap)
657 {
658 	int error, sockv[2];
659 
660 	error = kern_socketpair(uap->domain, uap->type, uap->protocol, sockv);
661 
662 	if (error == 0) {
663 		error = copyout(sockv, uap->rsv, sizeof(sockv));
664 
665 		if (error != 0) {
666 			kern_close(sockv[0]);
667 			kern_close(sockv[1]);
668 		}
669 	}
670 
671 	return (error);
672 }
673 
674 int
675 kern_sendmsg(int s, struct sockaddr *sa, struct uio *auio,
676 	     struct mbuf *control, int flags, size_t *res)
677 {
678 	struct thread *td = curthread;
679 	struct lwp *lp = td->td_lwp;
680 	struct proc *p = td->td_proc;
681 	struct file *fp;
682 	size_t len;
683 	int error;
684 	struct socket *so;
685 #ifdef KTRACE
686 	struct iovec *ktriov = NULL;
687 	struct uio ktruio;
688 #endif
689 
690 	error = holdsock(p->p_fd, s, &fp);
691 	if (error)
692 		return (error);
693 #ifdef KTRACE
694 	if (KTRPOINT(td, KTR_GENIO)) {
695 		int iovlen = auio->uio_iovcnt * sizeof (struct iovec);
696 
697 		ktriov = kmalloc(iovlen, M_TEMP, M_WAITOK);
698 		bcopy((caddr_t)auio->uio_iov, (caddr_t)ktriov, iovlen);
699 		ktruio = *auio;
700 	}
701 #endif
702 	len = auio->uio_resid;
703 	so = (struct socket *)fp->f_data;
704 	if ((flags & (MSG_FNONBLOCKING|MSG_FBLOCKING)) == 0) {
705 		if (fp->f_flag & FNONBLOCK)
706 			flags |= MSG_FNONBLOCKING;
707 	}
708 	error = so_pru_sosend(so, sa, auio, NULL, control, flags, td);
709 	if (error) {
710 		if (auio->uio_resid != len && (error == ERESTART ||
711 		    error == EINTR || error == EWOULDBLOCK))
712 			error = 0;
713 		if (error == EPIPE && !(flags & MSG_NOSIGNAL))
714 			lwpsignal(p, lp, SIGPIPE);
715 	}
716 #ifdef KTRACE
717 	if (ktriov != NULL) {
718 		if (error == 0) {
719 			ktruio.uio_iov = ktriov;
720 			ktruio.uio_resid = len - auio->uio_resid;
721 			ktrgenio(lp, s, UIO_WRITE, &ktruio, error);
722 		}
723 		kfree(ktriov, M_TEMP);
724 	}
725 #endif
726 	if (error == 0)
727 		*res  = len - auio->uio_resid;
728 	fdrop(fp);
729 	return (error);
730 }
731 
732 /*
733  * sendto_args(int s, caddr_t buf, size_t len, int flags, caddr_t to, int tolen)
734  *
735  * MPALMOSTSAFE
736  */
737 int
738 sys_sendto(struct sendto_args *uap)
739 {
740 	struct thread *td = curthread;
741 	struct uio auio;
742 	struct iovec aiov;
743 	struct sockaddr *sa = NULL;
744 	int error;
745 
746 	if (uap->to) {
747 		error = getsockaddr(&sa, uap->to, uap->tolen);
748 		if (error)
749 			return (error);
750 	}
751 	aiov.iov_base = uap->buf;
752 	aiov.iov_len = uap->len;
753 	auio.uio_iov = &aiov;
754 	auio.uio_iovcnt = 1;
755 	auio.uio_offset = 0;
756 	auio.uio_resid = uap->len;
757 	auio.uio_segflg = UIO_USERSPACE;
758 	auio.uio_rw = UIO_WRITE;
759 	auio.uio_td = td;
760 
761 	error = kern_sendmsg(uap->s, sa, &auio, NULL, uap->flags,
762 			     &uap->sysmsg_szresult);
763 
764 	if (sa)
765 		kfree(sa, M_SONAME);
766 	return (error);
767 }
768 
769 /*
770  * sendmsg_args(int s, caddr_t msg, int flags)
771  *
772  * MPALMOSTSAFE
773  */
774 int
775 sys_sendmsg(struct sendmsg_args *uap)
776 {
777 	struct thread *td = curthread;
778 	struct msghdr msg;
779 	struct uio auio;
780 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
781 	struct sockaddr *sa = NULL;
782 	struct mbuf *control = NULL;
783 	int error;
784 
785 	error = copyin(uap->msg, (caddr_t)&msg, sizeof(msg));
786 	if (error)
787 		return (error);
788 
789 	/*
790 	 * Conditionally copyin msg.msg_name.
791 	 */
792 	if (msg.msg_name) {
793 		error = getsockaddr(&sa, msg.msg_name, msg.msg_namelen);
794 		if (error)
795 			return (error);
796 	}
797 
798 	/*
799 	 * Populate auio.
800 	 */
801 	error = iovec_copyin(msg.msg_iov, &iov, aiov, msg.msg_iovlen,
802 			     &auio.uio_resid);
803 	if (error)
804 		goto cleanup2;
805 	auio.uio_iov = iov;
806 	auio.uio_iovcnt = msg.msg_iovlen;
807 	auio.uio_offset = 0;
808 	auio.uio_segflg = UIO_USERSPACE;
809 	auio.uio_rw = UIO_WRITE;
810 	auio.uio_td = td;
811 
812 	/*
813 	 * Conditionally copyin msg.msg_control.
814 	 */
815 	if (msg.msg_control) {
816 		if (msg.msg_controllen < sizeof(struct cmsghdr) ||
817 		    msg.msg_controllen > MLEN) {
818 			error = EINVAL;
819 			goto cleanup;
820 		}
821 		control = m_get(MB_WAIT, MT_CONTROL);
822 		if (control == NULL) {
823 			error = ENOBUFS;
824 			goto cleanup;
825 		}
826 		control->m_len = msg.msg_controllen;
827 		error = copyin(msg.msg_control, mtod(control, caddr_t),
828 			       msg.msg_controllen);
829 		if (error) {
830 			m_free(control);
831 			goto cleanup;
832 		}
833 	}
834 
835 	error = kern_sendmsg(uap->s, sa, &auio, control, uap->flags,
836 			     &uap->sysmsg_szresult);
837 
838 cleanup:
839 	iovec_free(&iov, aiov);
840 cleanup2:
841 	if (sa)
842 		kfree(sa, M_SONAME);
843 	return (error);
844 }
845 
846 /*
847  * kern_recvmsg() takes a handle to sa and control.  If the handle is non-
848  * null, it returns a dynamically allocated struct sockaddr and an mbuf.
849  * Don't forget to FREE() and m_free() these if they are returned.
850  */
851 int
852 kern_recvmsg(int s, struct sockaddr **sa, struct uio *auio,
853 	     struct mbuf **control, int *flags, size_t *res)
854 {
855 	struct thread *td = curthread;
856 	struct proc *p = td->td_proc;
857 	struct file *fp;
858 	size_t len;
859 	int error;
860 	int lflags;
861 	struct socket *so;
862 #ifdef KTRACE
863 	struct iovec *ktriov = NULL;
864 	struct uio ktruio;
865 #endif
866 
867 	error = holdsock(p->p_fd, s, &fp);
868 	if (error)
869 		return (error);
870 #ifdef KTRACE
871 	if (KTRPOINT(td, KTR_GENIO)) {
872 		int iovlen = auio->uio_iovcnt * sizeof (struct iovec);
873 
874 		ktriov = kmalloc(iovlen, M_TEMP, M_WAITOK);
875 		bcopy(auio->uio_iov, ktriov, iovlen);
876 		ktruio = *auio;
877 	}
878 #endif
879 	len = auio->uio_resid;
880 	so = (struct socket *)fp->f_data;
881 
882 	if (flags == NULL || (*flags & (MSG_FNONBLOCKING|MSG_FBLOCKING)) == 0) {
883 		if (fp->f_flag & FNONBLOCK) {
884 			if (flags) {
885 				*flags |= MSG_FNONBLOCKING;
886 			} else {
887 				lflags = MSG_FNONBLOCKING;
888 				flags = &lflags;
889 			}
890 		}
891 	}
892 
893 	error = so_pru_soreceive(so, sa, auio, NULL, control, flags);
894 	if (error) {
895 		if (auio->uio_resid != len && (error == ERESTART ||
896 		    error == EINTR || error == EWOULDBLOCK))
897 			error = 0;
898 	}
899 #ifdef KTRACE
900 	if (ktriov != NULL) {
901 		if (error == 0) {
902 			ktruio.uio_iov = ktriov;
903 			ktruio.uio_resid = len - auio->uio_resid;
904 			ktrgenio(td->td_lwp, s, UIO_READ, &ktruio, error);
905 		}
906 		kfree(ktriov, M_TEMP);
907 	}
908 #endif
909 	if (error == 0)
910 		*res = len - auio->uio_resid;
911 	fdrop(fp);
912 	return (error);
913 }
914 
915 /*
916  * recvfrom_args(int s, caddr_t buf, size_t len, int flags,
917  *			caddr_t from, int *fromlenaddr)
918  *
919  * MPALMOSTSAFE
920  */
921 int
922 sys_recvfrom(struct recvfrom_args *uap)
923 {
924 	struct thread *td = curthread;
925 	struct uio auio;
926 	struct iovec aiov;
927 	struct sockaddr *sa = NULL;
928 	int error, fromlen;
929 
930 	if (uap->from && uap->fromlenaddr) {
931 		error = copyin(uap->fromlenaddr, &fromlen, sizeof(fromlen));
932 		if (error)
933 			return (error);
934 		if (fromlen < 0)
935 			return (EINVAL);
936 	} else {
937 		fromlen = 0;
938 	}
939 	aiov.iov_base = uap->buf;
940 	aiov.iov_len = uap->len;
941 	auio.uio_iov = &aiov;
942 	auio.uio_iovcnt = 1;
943 	auio.uio_offset = 0;
944 	auio.uio_resid = uap->len;
945 	auio.uio_segflg = UIO_USERSPACE;
946 	auio.uio_rw = UIO_READ;
947 	auio.uio_td = td;
948 
949 	error = kern_recvmsg(uap->s, uap->from ? &sa : NULL, &auio, NULL,
950 			     &uap->flags, &uap->sysmsg_szresult);
951 
952 	if (error == 0 && uap->from) {
953 		/* note: sa may still be NULL */
954 		if (sa) {
955 			fromlen = MIN(fromlen, sa->sa_len);
956 			error = copyout(sa, uap->from, fromlen);
957 		} else {
958 			fromlen = 0;
959 		}
960 		if (error == 0) {
961 			error = copyout(&fromlen, uap->fromlenaddr,
962 					sizeof(fromlen));
963 		}
964 	}
965 	if (sa)
966 		kfree(sa, M_SONAME);
967 
968 	return (error);
969 }
970 
971 /*
972  * recvmsg_args(int s, struct msghdr *msg, int flags)
973  *
974  * MPALMOSTSAFE
975  */
976 int
977 sys_recvmsg(struct recvmsg_args *uap)
978 {
979 	struct thread *td = curthread;
980 	struct msghdr msg;
981 	struct uio auio;
982 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
983 	struct mbuf *m, *control = NULL;
984 	struct sockaddr *sa = NULL;
985 	caddr_t ctlbuf;
986 	socklen_t *ufromlenp, *ucontrollenp;
987 	int error, fromlen, controllen, len, flags, *uflagsp;
988 
989 	/*
990 	 * This copyin handles everything except the iovec.
991 	 */
992 	error = copyin(uap->msg, &msg, sizeof(msg));
993 	if (error)
994 		return (error);
995 
996 	if (msg.msg_name && msg.msg_namelen < 0)
997 		return (EINVAL);
998 	if (msg.msg_control && msg.msg_controllen < 0)
999 		return (EINVAL);
1000 
1001 	ufromlenp = (socklen_t *)((caddr_t)uap->msg + offsetof(struct msghdr,
1002 		    msg_namelen));
1003 	ucontrollenp = (socklen_t *)((caddr_t)uap->msg + offsetof(struct msghdr,
1004 		       msg_controllen));
1005 	uflagsp = (int *)((caddr_t)uap->msg + offsetof(struct msghdr,
1006 							msg_flags));
1007 
1008 	/*
1009 	 * Populate auio.
1010 	 */
1011 	error = iovec_copyin(msg.msg_iov, &iov, aiov, msg.msg_iovlen,
1012 			     &auio.uio_resid);
1013 	if (error)
1014 		return (error);
1015 	auio.uio_iov = iov;
1016 	auio.uio_iovcnt = msg.msg_iovlen;
1017 	auio.uio_offset = 0;
1018 	auio.uio_segflg = UIO_USERSPACE;
1019 	auio.uio_rw = UIO_READ;
1020 	auio.uio_td = td;
1021 
1022 	flags = uap->flags;
1023 
1024 	error = kern_recvmsg(uap->s,
1025 			     (msg.msg_name ? &sa : NULL), &auio,
1026 			     (msg.msg_control ? &control : NULL), &flags,
1027 			     &uap->sysmsg_szresult);
1028 
1029 	/*
1030 	 * Conditionally copyout the name and populate the namelen field.
1031 	 */
1032 	if (error == 0 && msg.msg_name) {
1033 		/* note: sa may still be NULL */
1034 		if (sa != NULL) {
1035 			fromlen = MIN(msg.msg_namelen, sa->sa_len);
1036 			error = copyout(sa, msg.msg_name, fromlen);
1037 		} else {
1038 			fromlen = 0;
1039 		}
1040 		if (error == 0)
1041 			error = copyout(&fromlen, ufromlenp,
1042 			    sizeof(*ufromlenp));
1043 	}
1044 
1045 	/*
1046 	 * Copyout msg.msg_control and msg.msg_controllen.
1047 	 */
1048 	if (error == 0 && msg.msg_control) {
1049 		len = msg.msg_controllen;
1050 		m = control;
1051 		ctlbuf = (caddr_t)msg.msg_control;
1052 
1053 		while(m && len > 0) {
1054 			unsigned int tocopy;
1055 
1056 			if (len >= m->m_len) {
1057 				tocopy = m->m_len;
1058 			} else {
1059 				msg.msg_flags |= MSG_CTRUNC;
1060 				tocopy = len;
1061 			}
1062 
1063 			error = copyout(mtod(m, caddr_t), ctlbuf, tocopy);
1064 			if (error)
1065 				goto cleanup;
1066 
1067 			ctlbuf += tocopy;
1068 			len -= tocopy;
1069 			m = m->m_next;
1070 		}
1071 		controllen = ctlbuf - (caddr_t)msg.msg_control;
1072 		error = copyout(&controllen, ucontrollenp,
1073 		    sizeof(*ucontrollenp));
1074 	}
1075 
1076 	if (error == 0)
1077 		error = copyout(&flags, uflagsp, sizeof(*uflagsp));
1078 
1079 cleanup:
1080 	if (sa)
1081 		kfree(sa, M_SONAME);
1082 	iovec_free(&iov, aiov);
1083 	if (control)
1084 		m_freem(control);
1085 	return (error);
1086 }
1087 
1088 /*
1089  * If sopt->sopt_td == NULL, then sopt->sopt_val is treated as an
1090  * in kernel pointer instead of a userland pointer.  This allows us
1091  * to manipulate socket options in the emulation code.
1092  */
1093 int
1094 kern_setsockopt(int s, struct sockopt *sopt)
1095 {
1096 	struct thread *td = curthread;
1097 	struct proc *p = td->td_proc;
1098 	struct file *fp;
1099 	int error;
1100 
1101 	if (sopt->sopt_val == NULL && sopt->sopt_valsize != 0)
1102 		return (EFAULT);
1103 	if (sopt->sopt_val != NULL && sopt->sopt_valsize == 0)
1104 		return (EINVAL);
1105 	if (sopt->sopt_valsize > SOMAXOPT_SIZE)	/* unsigned */
1106 		return (EINVAL);
1107 
1108 	error = holdsock(p->p_fd, s, &fp);
1109 	if (error)
1110 		return (error);
1111 
1112 	error = sosetopt((struct socket *)fp->f_data, sopt);
1113 	fdrop(fp);
1114 	return (error);
1115 }
1116 
1117 /*
1118  * setsockopt_args(int s, int level, int name, caddr_t val, int valsize)
1119  *
1120  * MPALMOSTSAFE
1121  */
1122 int
1123 sys_setsockopt(struct setsockopt_args *uap)
1124 {
1125 	struct thread *td = curthread;
1126 	struct sockopt sopt;
1127 	int error;
1128 
1129 	sopt.sopt_level = uap->level;
1130 	sopt.sopt_name = uap->name;
1131 	sopt.sopt_valsize = uap->valsize;
1132 	sopt.sopt_td = td;
1133 	sopt.sopt_val = NULL;
1134 
1135 	if (sopt.sopt_valsize > SOMAXOPT_SIZE) /* unsigned */
1136 		return (EINVAL);
1137 	if (uap->val) {
1138 		sopt.sopt_val = kmalloc(sopt.sopt_valsize, M_TEMP, M_WAITOK);
1139 		error = copyin(uap->val, sopt.sopt_val, sopt.sopt_valsize);
1140 		if (error)
1141 			goto out;
1142 	}
1143 
1144 	error = kern_setsockopt(uap->s, &sopt);
1145 out:
1146 	if (uap->val)
1147 		kfree(sopt.sopt_val, M_TEMP);
1148 	return(error);
1149 }
1150 
1151 /*
1152  * If sopt->sopt_td == NULL, then sopt->sopt_val is treated as an
1153  * in kernel pointer instead of a userland pointer.  This allows us
1154  * to manipulate socket options in the emulation code.
1155  */
1156 int
1157 kern_getsockopt(int s, struct sockopt *sopt)
1158 {
1159 	struct thread *td = curthread;
1160 	struct proc *p = td->td_proc;
1161 	struct file *fp;
1162 	int error;
1163 
1164 	if (sopt->sopt_val == NULL && sopt->sopt_valsize != 0)
1165 		return (EFAULT);
1166 	if (sopt->sopt_val != NULL && sopt->sopt_valsize == 0)
1167 		return (EINVAL);
1168 	if (sopt->sopt_valsize > SOMAXOPT_SIZE) /* unsigned */
1169 		return (EINVAL);
1170 
1171 	error = holdsock(p->p_fd, s, &fp);
1172 	if (error)
1173 		return (error);
1174 
1175 	error = sogetopt((struct socket *)fp->f_data, sopt);
1176 	fdrop(fp);
1177 	return (error);
1178 }
1179 
1180 /*
1181  * getsockopt_args(int s, int level, int name, caddr_t val, int *avalsize)
1182  *
1183  * MPALMOSTSAFE
1184  */
1185 int
1186 sys_getsockopt(struct getsockopt_args *uap)
1187 {
1188 	struct thread *td = curthread;
1189 	struct	sockopt sopt;
1190 	int	error, valsize;
1191 
1192 	if (uap->val) {
1193 		error = copyin(uap->avalsize, &valsize, sizeof(valsize));
1194 		if (error)
1195 			return (error);
1196 	} else {
1197 		valsize = 0;
1198 	}
1199 
1200 	sopt.sopt_level = uap->level;
1201 	sopt.sopt_name = uap->name;
1202 	sopt.sopt_valsize = valsize;
1203 	sopt.sopt_td = td;
1204 	sopt.sopt_val = NULL;
1205 
1206 	if (sopt.sopt_valsize > SOMAXOPT_SIZE) /* unsigned */
1207 		return (EINVAL);
1208 	if (uap->val) {
1209 		sopt.sopt_val = kmalloc(sopt.sopt_valsize, M_TEMP, M_WAITOK);
1210 		error = copyin(uap->val, sopt.sopt_val, sopt.sopt_valsize);
1211 		if (error)
1212 			goto out;
1213 	}
1214 
1215 	error = kern_getsockopt(uap->s, &sopt);
1216 	if (error)
1217 		goto out;
1218 	valsize = sopt.sopt_valsize;
1219 	error = copyout(&valsize, uap->avalsize, sizeof(valsize));
1220 	if (error)
1221 		goto out;
1222 	if (uap->val)
1223 		error = copyout(sopt.sopt_val, uap->val, sopt.sopt_valsize);
1224 out:
1225 	if (uap->val)
1226 		kfree(sopt.sopt_val, M_TEMP);
1227 	return (error);
1228 }
1229 
1230 /*
1231  * The second argument to kern_getsockname() is a handle to a struct sockaddr.
1232  * This allows kern_getsockname() to return a pointer to an allocated struct
1233  * sockaddr which must be freed later with FREE().  The caller must
1234  * initialize *name to NULL.
1235  */
1236 int
1237 kern_getsockname(int s, struct sockaddr **name, int *namelen)
1238 {
1239 	struct thread *td = curthread;
1240 	struct proc *p = td->td_proc;
1241 	struct file *fp;
1242 	struct socket *so;
1243 	struct sockaddr *sa = NULL;
1244 	int error;
1245 
1246 	error = holdsock(p->p_fd, s, &fp);
1247 	if (error)
1248 		return (error);
1249 	if (*namelen < 0) {
1250 		fdrop(fp);
1251 		return (EINVAL);
1252 	}
1253 	so = (struct socket *)fp->f_data;
1254 	error = so_pru_sockaddr(so, &sa);
1255 	if (error == 0) {
1256 		if (sa == NULL) {
1257 			*namelen = 0;
1258 		} else {
1259 			*namelen = MIN(*namelen, sa->sa_len);
1260 			*name = sa;
1261 		}
1262 	}
1263 
1264 	fdrop(fp);
1265 	return (error);
1266 }
1267 
1268 /*
1269  * getsockname_args(int fdes, caddr_t asa, int *alen)
1270  *
1271  * Get socket name.
1272  *
1273  * MPALMOSTSAFE
1274  */
1275 int
1276 sys_getsockname(struct getsockname_args *uap)
1277 {
1278 	struct sockaddr *sa = NULL;
1279 	int error, sa_len;
1280 
1281 	error = copyin(uap->alen, &sa_len, sizeof(sa_len));
1282 	if (error)
1283 		return (error);
1284 
1285 	error = kern_getsockname(uap->fdes, &sa, &sa_len);
1286 
1287 	if (error == 0)
1288 		error = copyout(sa, uap->asa, sa_len);
1289 	if (error == 0)
1290 		error = copyout(&sa_len, uap->alen, sizeof(*uap->alen));
1291 	if (sa)
1292 		kfree(sa, M_SONAME);
1293 	return (error);
1294 }
1295 
1296 /*
1297  * The second argument to kern_getpeername() is a handle to a struct sockaddr.
1298  * This allows kern_getpeername() to return a pointer to an allocated struct
1299  * sockaddr which must be freed later with FREE().  The caller must
1300  * initialize *name to NULL.
1301  */
1302 int
1303 kern_getpeername(int s, struct sockaddr **name, int *namelen)
1304 {
1305 	struct thread *td = curthread;
1306 	struct proc *p = td->td_proc;
1307 	struct file *fp;
1308 	struct socket *so;
1309 	struct sockaddr *sa = NULL;
1310 	int error;
1311 
1312 	error = holdsock(p->p_fd, s, &fp);
1313 	if (error)
1314 		return (error);
1315 	if (*namelen < 0) {
1316 		fdrop(fp);
1317 		return (EINVAL);
1318 	}
1319 	so = (struct socket *)fp->f_data;
1320 	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
1321 		fdrop(fp);
1322 		return (ENOTCONN);
1323 	}
1324 	error = so_pru_peeraddr(so, &sa);
1325 	if (error == 0) {
1326 		if (sa == NULL) {
1327 			*namelen = 0;
1328 		} else {
1329 			*namelen = MIN(*namelen, sa->sa_len);
1330 			*name = sa;
1331 		}
1332 	}
1333 
1334 	fdrop(fp);
1335 	return (error);
1336 }
1337 
1338 /*
1339  * getpeername_args(int fdes, caddr_t asa, int *alen)
1340  *
1341  * Get name of peer for connected socket.
1342  *
1343  * MPALMOSTSAFE
1344  */
1345 int
1346 sys_getpeername(struct getpeername_args *uap)
1347 {
1348 	struct sockaddr *sa = NULL;
1349 	int error, sa_len;
1350 
1351 	error = copyin(uap->alen, &sa_len, sizeof(sa_len));
1352 	if (error)
1353 		return (error);
1354 
1355 	error = kern_getpeername(uap->fdes, &sa, &sa_len);
1356 
1357 	if (error == 0)
1358 		error = copyout(sa, uap->asa, sa_len);
1359 	if (error == 0)
1360 		error = copyout(&sa_len, uap->alen, sizeof(*uap->alen));
1361 	if (sa)
1362 		kfree(sa, M_SONAME);
1363 	return (error);
1364 }
1365 
1366 int
1367 getsockaddr(struct sockaddr **namp, caddr_t uaddr, size_t len)
1368 {
1369 	struct sockaddr *sa;
1370 	int error;
1371 
1372 	*namp = NULL;
1373 	if (len > SOCK_MAXADDRLEN)
1374 		return ENAMETOOLONG;
1375 	if (len < offsetof(struct sockaddr, sa_data[0]))
1376 		return EDOM;
1377 	sa = kmalloc(len, M_SONAME, M_WAITOK);
1378 	error = copyin(uaddr, sa, len);
1379 	if (error) {
1380 		kfree(sa, M_SONAME);
1381 	} else {
1382 #if BYTE_ORDER != BIG_ENDIAN
1383 		/*
1384 		 * The bind(), connect(), and sendto() syscalls were not
1385 		 * versioned for COMPAT_43.  Thus, this check must stay.
1386 		 */
1387 		if (sa->sa_family == 0 && sa->sa_len < AF_MAX)
1388 			sa->sa_family = sa->sa_len;
1389 #endif
1390 		sa->sa_len = len;
1391 		*namp = sa;
1392 	}
1393 	return error;
1394 }
1395 
1396 /*
1397  * Detach a mapped page and release resources back to the system.
1398  * We must release our wiring and if the object is ripped out
1399  * from under the vm_page we become responsible for freeing the
1400  * page.
1401  *
1402  * MPSAFE
1403  */
1404 static void
1405 sf_buf_mfree(void *arg)
1406 {
1407 	struct sf_buf *sf = arg;
1408 	vm_page_t m;
1409 
1410 	m = sf_buf_page(sf);
1411 	if (sf_buf_free(sf)) {
1412 		/* sf invalid now */
1413 		vm_page_busy_wait(m, FALSE, "sockpgf");
1414 		vm_page_unwire(m, 0);
1415 		if (m->wire_count == 0 && m->object == NULL) {
1416 			vm_page_free(m);
1417 		} else {
1418 			vm_page_wakeup(m);
1419 		}
1420 	}
1421 }
1422 
1423 /*
1424  * sendfile(2).
1425  * int sendfile(int fd, int s, off_t offset, size_t nbytes,
1426  *	 struct sf_hdtr *hdtr, off_t *sbytes, int flags)
1427  *
1428  * Send a file specified by 'fd' and starting at 'offset' to a socket
1429  * specified by 's'. Send only 'nbytes' of the file or until EOF if
1430  * nbytes == 0. Optionally add a header and/or trailer to the socket
1431  * output. If specified, write the total number of bytes sent into *sbytes.
1432  *
1433  * In FreeBSD kern/uipc_syscalls.c,v 1.103, a bug was fixed that caused
1434  * the headers to count against the remaining bytes to be sent from
1435  * the file descriptor.  We may wish to implement a compatibility syscall
1436  * in the future.
1437  *
1438  * MPALMOSTSAFE
1439  */
1440 int
1441 sys_sendfile(struct sendfile_args *uap)
1442 {
1443 	struct thread *td = curthread;
1444 	struct proc *p = td->td_proc;
1445 	struct file *fp;
1446 	struct vnode *vp = NULL;
1447 	struct sf_hdtr hdtr;
1448 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
1449 	struct uio auio;
1450 	struct mbuf *mheader = NULL;
1451 	size_t hbytes = 0;
1452 	size_t tbytes;
1453 	off_t hdtr_size = 0;
1454 	off_t sbytes;
1455 	int error;
1456 
1457 	KKASSERT(p);
1458 
1459 	/*
1460 	 * Do argument checking. Must be a regular file in, stream
1461 	 * type and connected socket out, positive offset.
1462 	 */
1463 	fp = holdfp(p->p_fd, uap->fd, FREAD);
1464 	if (fp == NULL) {
1465 		return (EBADF);
1466 	}
1467 	if (fp->f_type != DTYPE_VNODE) {
1468 		fdrop(fp);
1469 		return (EINVAL);
1470 	}
1471 	vp = (struct vnode *)fp->f_data;
1472 	vref(vp);
1473 	fdrop(fp);
1474 
1475 	/*
1476 	 * If specified, get the pointer to the sf_hdtr struct for
1477 	 * any headers/trailers.
1478 	 */
1479 	if (uap->hdtr) {
1480 		error = copyin(uap->hdtr, &hdtr, sizeof(hdtr));
1481 		if (error)
1482 			goto done;
1483 		/*
1484 		 * Send any headers.
1485 		 */
1486 		if (hdtr.headers) {
1487 			error = iovec_copyin(hdtr.headers, &iov, aiov,
1488 					     hdtr.hdr_cnt, &hbytes);
1489 			if (error)
1490 				goto done;
1491 			auio.uio_iov = iov;
1492 			auio.uio_iovcnt = hdtr.hdr_cnt;
1493 			auio.uio_offset = 0;
1494 			auio.uio_segflg = UIO_USERSPACE;
1495 			auio.uio_rw = UIO_WRITE;
1496 			auio.uio_td = td;
1497 			auio.uio_resid = hbytes;
1498 
1499 			mheader = m_uiomove(&auio);
1500 
1501 			iovec_free(&iov, aiov);
1502 			if (mheader == NULL)
1503 				goto done;
1504 		}
1505 	}
1506 
1507 	error = kern_sendfile(vp, uap->s, uap->offset, uap->nbytes, mheader,
1508 			      &sbytes, uap->flags);
1509 	if (error)
1510 		goto done;
1511 
1512 	/*
1513 	 * Send trailers. Wimp out and use writev(2).
1514 	 */
1515 	if (uap->hdtr != NULL && hdtr.trailers != NULL) {
1516 		error = iovec_copyin(hdtr.trailers, &iov, aiov,
1517 				     hdtr.trl_cnt, &auio.uio_resid);
1518 		if (error)
1519 			goto done;
1520 		auio.uio_iov = iov;
1521 		auio.uio_iovcnt = hdtr.trl_cnt;
1522 		auio.uio_offset = 0;
1523 		auio.uio_segflg = UIO_USERSPACE;
1524 		auio.uio_rw = UIO_WRITE;
1525 		auio.uio_td = td;
1526 
1527 		error = kern_sendmsg(uap->s, NULL, &auio, NULL, 0, &tbytes);
1528 
1529 		iovec_free(&iov, aiov);
1530 		if (error)
1531 			goto done;
1532 		hdtr_size += tbytes;	/* trailer bytes successfully sent */
1533 	}
1534 
1535 done:
1536 	if (vp)
1537 		vrele(vp);
1538 	if (uap->sbytes != NULL) {
1539 		sbytes += hdtr_size;
1540 		copyout(&sbytes, uap->sbytes, sizeof(off_t));
1541 	}
1542 	return (error);
1543 }
1544 
1545 int
1546 kern_sendfile(struct vnode *vp, int sfd, off_t offset, size_t nbytes,
1547 	      struct mbuf *mheader, off_t *sbytes, int flags)
1548 {
1549 	struct thread *td = curthread;
1550 	struct proc *p = td->td_proc;
1551 	struct vm_object *obj;
1552 	struct socket *so;
1553 	struct file *fp;
1554 	struct mbuf *m;
1555 	struct sf_buf *sf;
1556 	struct vm_page *pg;
1557 	off_t off, xfsize;
1558 	off_t hbytes = 0;
1559 	int error = 0;
1560 
1561 	if (vp->v_type != VREG) {
1562 		error = EINVAL;
1563 		goto done0;
1564 	}
1565 	if ((obj = vp->v_object) == NULL) {
1566 		error = EINVAL;
1567 		goto done0;
1568 	}
1569 	error = holdsock(p->p_fd, sfd, &fp);
1570 	if (error)
1571 		goto done0;
1572 	so = (struct socket *)fp->f_data;
1573 	if (so->so_type != SOCK_STREAM) {
1574 		error = EINVAL;
1575 		goto done;
1576 	}
1577 	if ((so->so_state & SS_ISCONNECTED) == 0) {
1578 		error = ENOTCONN;
1579 		goto done;
1580 	}
1581 	if (offset < 0) {
1582 		error = EINVAL;
1583 		goto done;
1584 	}
1585 
1586 	*sbytes = 0;
1587 	/*
1588 	 * Protect against multiple writers to the socket.
1589 	 */
1590 	ssb_lock(&so->so_snd, M_WAITOK);
1591 
1592 	/*
1593 	 * Loop through the pages in the file, starting with the requested
1594 	 * offset. Get a file page (do I/O if necessary), map the file page
1595 	 * into an sf_buf, attach an mbuf header to the sf_buf, and queue
1596 	 * it on the socket.
1597 	 */
1598 	for (off = offset; ; off += xfsize, *sbytes += xfsize + hbytes) {
1599 		vm_pindex_t pindex;
1600 		vm_offset_t pgoff;
1601 
1602 		pindex = OFF_TO_IDX(off);
1603 retry_lookup:
1604 		/*
1605 		 * Calculate the amount to transfer. Not to exceed a page,
1606 		 * the EOF, or the passed in nbytes.
1607 		 */
1608 		xfsize = vp->v_filesize - off;
1609 		if (xfsize > PAGE_SIZE)
1610 			xfsize = PAGE_SIZE;
1611 		pgoff = (vm_offset_t)(off & PAGE_MASK);
1612 		if (PAGE_SIZE - pgoff < xfsize)
1613 			xfsize = PAGE_SIZE - pgoff;
1614 		if (nbytes && xfsize > (nbytes - *sbytes))
1615 			xfsize = nbytes - *sbytes;
1616 		if (xfsize <= 0)
1617 			break;
1618 		/*
1619 		 * Optimize the non-blocking case by looking at the socket space
1620 		 * before going to the extra work of constituting the sf_buf.
1621 		 */
1622 		if ((fp->f_flag & FNONBLOCK) && ssb_space(&so->so_snd) <= 0) {
1623 			if (so->so_state & SS_CANTSENDMORE)
1624 				error = EPIPE;
1625 			else
1626 				error = EAGAIN;
1627 			ssb_unlock(&so->so_snd);
1628 			goto done;
1629 		}
1630 		/*
1631 		 * Attempt to look up the page.
1632 		 *
1633 		 *	Allocate if not found, wait and loop if busy, then
1634 		 *	wire the page.  critical section protection is
1635 		 * 	required to maintain the object association (an
1636 		 *	interrupt can free the page) through to the
1637 		 *	vm_page_wire() call.
1638 		 */
1639 		vm_object_hold(obj);
1640 		pg = vm_page_lookup_busy_try(obj, pindex, TRUE, &error);
1641 		if (error) {
1642 			vm_page_sleep_busy(pg, TRUE, "sfpbsy");
1643 			vm_object_drop(obj);
1644 			goto retry_lookup;
1645 		}
1646 		if (pg == NULL) {
1647 			pg = vm_page_alloc(obj, pindex, VM_ALLOC_NORMAL |
1648 							VM_ALLOC_NULL_OK);
1649 			if (pg == NULL) {
1650 				vm_wait(0);
1651 				vm_object_drop(obj);
1652 				goto retry_lookup;
1653 			}
1654 		}
1655 		vm_page_wire(pg);
1656 		vm_object_drop(obj);
1657 
1658 		/*
1659 		 * If page is not valid for what we need, initiate I/O
1660 		 */
1661 
1662 		if (!pg->valid || !vm_page_is_valid(pg, pgoff, xfsize)) {
1663 			struct uio auio;
1664 			struct iovec aiov;
1665 			int bsize;
1666 
1667 			/*
1668 			 * Ensure that our page is still around when the I/O
1669 			 * completes.
1670 			 */
1671 			vm_page_io_start(pg);
1672 			vm_page_wakeup(pg);
1673 
1674 			/*
1675 			 * Get the page from backing store.
1676 			 */
1677 			bsize = vp->v_mount->mnt_stat.f_iosize;
1678 			auio.uio_iov = &aiov;
1679 			auio.uio_iovcnt = 1;
1680 			aiov.iov_base = 0;
1681 			aiov.iov_len = MAXBSIZE;
1682 			auio.uio_resid = MAXBSIZE;
1683 			auio.uio_offset = trunc_page(off);
1684 			auio.uio_segflg = UIO_NOCOPY;
1685 			auio.uio_rw = UIO_READ;
1686 			auio.uio_td = td;
1687 			vn_lock(vp, LK_SHARED | LK_RETRY);
1688 			error = VOP_READ(vp, &auio,
1689 				    IO_VMIO | ((MAXBSIZE / bsize) << 16),
1690 				    td->td_ucred);
1691 			vn_unlock(vp);
1692 			vm_page_flag_clear(pg, PG_ZERO);
1693 			vm_page_busy_wait(pg, FALSE, "sockpg");
1694 			vm_page_io_finish(pg);
1695 			if (error) {
1696 				vm_page_unwire(pg, 0);
1697 				vm_page_wakeup(pg);
1698 				vm_page_try_to_free(pg);
1699 				ssb_unlock(&so->so_snd);
1700 				goto done;
1701 			}
1702 		}
1703 
1704 
1705 		/*
1706 		 * Get a sendfile buf. We usually wait as long as necessary,
1707 		 * but this wait can be interrupted.
1708 		 */
1709 		if ((sf = sf_buf_alloc(pg)) == NULL) {
1710 			vm_page_unwire(pg, 0);
1711 			vm_page_wakeup(pg);
1712 			vm_page_try_to_free(pg);
1713 			ssb_unlock(&so->so_snd);
1714 			error = EINTR;
1715 			goto done;
1716 		}
1717 		vm_page_wakeup(pg);
1718 
1719 		/*
1720 		 * Get an mbuf header and set it up as having external storage.
1721 		 */
1722 		MGETHDR(m, MB_WAIT, MT_DATA);
1723 		if (m == NULL) {
1724 			error = ENOBUFS;
1725 			sf_buf_free(sf);
1726 			ssb_unlock(&so->so_snd);
1727 			goto done;
1728 		}
1729 
1730 		m->m_ext.ext_free = sf_buf_mfree;
1731 		m->m_ext.ext_ref = sf_buf_ref;
1732 		m->m_ext.ext_arg = sf;
1733 		m->m_ext.ext_buf = (void *)sf_buf_kva(sf);
1734 		m->m_ext.ext_size = PAGE_SIZE;
1735 		m->m_data = (char *)sf_buf_kva(sf) + pgoff;
1736 		m->m_flags |= M_EXT;
1737 		m->m_pkthdr.len = m->m_len = xfsize;
1738 		KKASSERT((m->m_flags & (M_EXT_CLUSTER)) == 0);
1739 
1740 		if (mheader != NULL) {
1741 			hbytes = mheader->m_pkthdr.len;
1742 			mheader->m_pkthdr.len += m->m_pkthdr.len;
1743 			m_cat(mheader, m);
1744 			m = mheader;
1745 			mheader = NULL;
1746 		} else
1747 			hbytes = 0;
1748 
1749 		/*
1750 		 * Add the buffer to the socket buffer chain.
1751 		 */
1752 		crit_enter();
1753 retry_space:
1754 		/*
1755 		 * Make sure that the socket is still able to take more data.
1756 		 * CANTSENDMORE being true usually means that the connection
1757 		 * was closed. so_error is true when an error was sensed after
1758 		 * a previous send.
1759 		 * The state is checked after the page mapping and buffer
1760 		 * allocation above since those operations may block and make
1761 		 * any socket checks stale. From this point forward, nothing
1762 		 * blocks before the pru_send (or more accurately, any blocking
1763 		 * results in a loop back to here to re-check).
1764 		 */
1765 		if ((so->so_state & SS_CANTSENDMORE) || so->so_error) {
1766 			if (so->so_state & SS_CANTSENDMORE) {
1767 				error = EPIPE;
1768 			} else {
1769 				error = so->so_error;
1770 				so->so_error = 0;
1771 			}
1772 			m_freem(m);
1773 			ssb_unlock(&so->so_snd);
1774 			crit_exit();
1775 			goto done;
1776 		}
1777 		/*
1778 		 * Wait for socket space to become available. We do this just
1779 		 * after checking the connection state above in order to avoid
1780 		 * a race condition with ssb_wait().
1781 		 */
1782 		if (ssb_space(&so->so_snd) < so->so_snd.ssb_lowat) {
1783 			if (fp->f_flag & FNONBLOCK) {
1784 				m_freem(m);
1785 				ssb_unlock(&so->so_snd);
1786 				crit_exit();
1787 				error = EAGAIN;
1788 				goto done;
1789 			}
1790 			error = ssb_wait(&so->so_snd);
1791 			/*
1792 			 * An error from ssb_wait usually indicates that we've
1793 			 * been interrupted by a signal. If we've sent anything
1794 			 * then return bytes sent, otherwise return the error.
1795 			 */
1796 			if (error) {
1797 				m_freem(m);
1798 				ssb_unlock(&so->so_snd);
1799 				crit_exit();
1800 				goto done;
1801 			}
1802 			goto retry_space;
1803 		}
1804 		error = so_pru_senda(so, 0, m, NULL, NULL, td);
1805 		crit_exit();
1806 		if (error) {
1807 			ssb_unlock(&so->so_snd);
1808 			goto done;
1809 		}
1810 	}
1811 	if (mheader != NULL) {
1812 		*sbytes += mheader->m_pkthdr.len;
1813 		error = so_pru_senda(so, 0, mheader, NULL, NULL, td);
1814 		mheader = NULL;
1815 	}
1816 	ssb_unlock(&so->so_snd);
1817 
1818 done:
1819 	fdrop(fp);
1820 done0:
1821 	if (mheader != NULL)
1822 		m_freem(mheader);
1823 	return (error);
1824 }
1825 
1826 /*
1827  * MPALMOSTSAFE
1828  */
1829 int
1830 sys_sctp_peeloff(struct sctp_peeloff_args *uap)
1831 {
1832 #ifdef SCTP
1833 	struct thread *td = curthread;
1834 	struct filedesc *fdp = td->td_proc->p_fd;
1835 	struct file *lfp = NULL;
1836 	struct file *nfp = NULL;
1837 	int error;
1838 	struct socket *head, *so;
1839 	caddr_t assoc_id;
1840 	int fd;
1841 	short fflag;		/* type must match fp->f_flag */
1842 
1843 	assoc_id = uap->name;
1844 	error = holdsock(td->td_proc->p_fd, uap->sd, &lfp);
1845 	if (error)
1846 		return (error);
1847 
1848 	crit_enter();
1849 	head = (struct socket *)lfp->f_data;
1850 	error = sctp_can_peel_off(head, assoc_id);
1851 	if (error) {
1852 		crit_exit();
1853 		goto done;
1854 	}
1855 	/*
1856 	 * At this point we know we do have a assoc to pull
1857 	 * we proceed to get the fd setup. This may block
1858 	 * but that is ok.
1859 	 */
1860 
1861 	fflag = lfp->f_flag;
1862 	error = falloc(td->td_lwp, &nfp, &fd);
1863 	if (error) {
1864 		/*
1865 		 * Probably ran out of file descriptors. Put the
1866 		 * unaccepted connection back onto the queue and
1867 		 * do another wakeup so some other process might
1868 		 * have a chance at it.
1869 		 */
1870 		crit_exit();
1871 		goto done;
1872 	}
1873 	uap->sysmsg_iresult = fd;
1874 
1875 	so = sctp_get_peeloff(head, assoc_id, &error);
1876 	if (so == NULL) {
1877 		/*
1878 		 * Either someone else peeled it off OR
1879 		 * we can't get a socket.
1880 		 */
1881 		goto noconnection;
1882 	}
1883 	soreference(so);			/* reference needed */
1884 	soclrstate(so, SS_NOFDREF | SS_COMP);	/* when clearing NOFDREF */
1885 	so->so_head = NULL;
1886 	if (head->so_sigio != NULL)
1887 		fsetown(fgetown(&head->so_sigio), &so->so_sigio);
1888 
1889 	nfp->f_type = DTYPE_SOCKET;
1890 	nfp->f_flag = fflag;
1891 	nfp->f_ops = &socketops;
1892 	nfp->f_data = so;
1893 
1894 noconnection:
1895 	/*
1896 	 * Assign the file pointer to the reserved descriptor, or clear
1897 	 * the reserved descriptor if an error occured.
1898 	 */
1899 	if (error)
1900 		fsetfd(fdp, NULL, fd);
1901 	else
1902 		fsetfd(fdp, nfp, fd);
1903 	crit_exit();
1904 	/*
1905 	 * Release explicitly held references before returning.
1906 	 */
1907 done:
1908 	if (nfp != NULL)
1909 		fdrop(nfp);
1910 	fdrop(lfp);
1911 	return (error);
1912 #else /* SCTP */
1913 	return(EOPNOTSUPP);
1914 #endif /* SCTP */
1915 }
1916