xref: /dragonfly/sys/kern/uipc_syscalls.c (revision 77b0c609)
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 extern int use_sendfile_async;
89 
90 /*
91  * System call interface to the socket abstraction.
92  */
93 
94 extern	struct fileops socketops;
95 
96 /*
97  * socket_args(int domain, int type, int protocol)
98  */
99 int
100 kern_socket(int domain, int type, int protocol, int *res)
101 {
102 	struct thread *td = curthread;
103 	struct filedesc *fdp = td->td_proc->p_fd;
104 	struct socket *so;
105 	struct file *fp;
106 	int fd, error;
107 
108 	KKASSERT(td->td_lwp);
109 
110 	error = falloc(td->td_lwp, &fp, &fd);
111 	if (error)
112 		return (error);
113 	error = socreate(domain, &so, type, protocol, td);
114 	if (error) {
115 		fsetfd(fdp, NULL, fd);
116 	} else {
117 		fp->f_type = DTYPE_SOCKET;
118 		fp->f_flag = FREAD | FWRITE;
119 		fp->f_ops = &socketops;
120 		fp->f_data = so;
121 		*res = fd;
122 		fsetfd(fdp, fp, fd);
123 	}
124 	fdrop(fp);
125 	return (error);
126 }
127 
128 /*
129  * MPALMOSTSAFE
130  */
131 int
132 sys_socket(struct socket_args *uap)
133 {
134 	int error;
135 
136 	error = kern_socket(uap->domain, uap->type, uap->protocol,
137 			    &uap->sysmsg_iresult);
138 
139 	return (error);
140 }
141 
142 int
143 kern_bind(int s, struct sockaddr *sa)
144 {
145 	struct thread *td = curthread;
146 	struct proc *p = td->td_proc;
147 	struct file *fp;
148 	int error;
149 
150 	KKASSERT(p);
151 	error = holdsock(p->p_fd, s, &fp);
152 	if (error)
153 		return (error);
154 	error = sobind((struct socket *)fp->f_data, sa, td);
155 	fdrop(fp);
156 	return (error);
157 }
158 
159 /*
160  * bind_args(int s, caddr_t name, int namelen)
161  *
162  * MPALMOSTSAFE
163  */
164 int
165 sys_bind(struct bind_args *uap)
166 {
167 	struct sockaddr *sa;
168 	int error;
169 
170 	error = getsockaddr(&sa, uap->name, uap->namelen);
171 	if (error)
172 		return (error);
173 	error = kern_bind(uap->s, sa);
174 	kfree(sa, M_SONAME);
175 
176 	return (error);
177 }
178 
179 int
180 kern_listen(int s, int backlog)
181 {
182 	struct thread *td = curthread;
183 	struct proc *p = td->td_proc;
184 	struct file *fp;
185 	int error;
186 
187 	KKASSERT(p);
188 	error = holdsock(p->p_fd, s, &fp);
189 	if (error)
190 		return (error);
191 	error = solisten((struct socket *)fp->f_data, backlog, td);
192 	fdrop(fp);
193 	return(error);
194 }
195 
196 /*
197  * listen_args(int s, int backlog)
198  *
199  * MPALMOSTSAFE
200  */
201 int
202 sys_listen(struct listen_args *uap)
203 {
204 	int error;
205 
206 	error = kern_listen(uap->s, uap->backlog);
207 	return (error);
208 }
209 
210 /*
211  * Returns the accepted socket as well.
212  *
213  * NOTE!  The sockets sitting on so_comp/so_incomp might have 0 refs, the
214  *	  pool token is absolutely required to avoid a sofree() race,
215  *	  as well as to avoid tailq handling races.
216  */
217 static boolean_t
218 soaccept_predicate(struct netmsg_so_notify *msg)
219 {
220 	struct socket *head = msg->base.nm_so;
221 	struct socket *so;
222 
223 	if (head->so_error != 0) {
224 		msg->base.lmsg.ms_error = head->so_error;
225 		return (TRUE);
226 	}
227 	lwkt_getpooltoken(head);
228 	if (!TAILQ_EMPTY(&head->so_comp)) {
229 		/* Abuse nm_so field as copy in/copy out parameter. XXX JH */
230 		so = TAILQ_FIRST(&head->so_comp);
231 		TAILQ_REMOVE(&head->so_comp, so, so_list);
232 		head->so_qlen--;
233 		soclrstate(so, SS_COMP);
234 		so->so_head = NULL;
235 		soreference(so);
236 
237 		lwkt_relpooltoken(head);
238 
239 		msg->base.lmsg.ms_error = 0;
240 		msg->base.nm_so = so;
241 		return (TRUE);
242 	}
243 	lwkt_relpooltoken(head);
244 	if (head->so_state & SS_CANTRCVMORE) {
245 		msg->base.lmsg.ms_error = ECONNABORTED;
246 		return (TRUE);
247 	}
248 	if (msg->nm_fflags & FNONBLOCK) {
249 		msg->base.lmsg.ms_error = EWOULDBLOCK;
250 		return (TRUE);
251 	}
252 
253 	return (FALSE);
254 }
255 
256 /*
257  * The second argument to kern_accept() is a handle to a struct sockaddr.
258  * This allows kern_accept() to return a pointer to an allocated struct
259  * sockaddr which must be freed later with FREE().  The caller must
260  * initialize *name to NULL.
261  */
262 int
263 kern_accept(int s, int fflags, struct sockaddr **name, int *namelen, int *res)
264 {
265 	struct thread *td = curthread;
266 	struct filedesc *fdp = td->td_proc->p_fd;
267 	struct file *lfp = NULL;
268 	struct file *nfp = NULL;
269 	struct sockaddr *sa;
270 	struct socket *head, *so;
271 	struct netmsg_so_notify msg;
272 	int fd;
273 	u_int fflag;		/* type must match fp->f_flag */
274 	int error, tmp;
275 
276 	*res = -1;
277 	if (name && namelen && *namelen < 0)
278 		return (EINVAL);
279 
280 	error = holdsock(td->td_proc->p_fd, s, &lfp);
281 	if (error)
282 		return (error);
283 
284 	error = falloc(td->td_lwp, &nfp, &fd);
285 	if (error) {		/* Probably ran out of file descriptors. */
286 		fdrop(lfp);
287 		return (error);
288 	}
289 	head = (struct socket *)lfp->f_data;
290 	if ((head->so_options & SO_ACCEPTCONN) == 0) {
291 		error = EINVAL;
292 		goto done;
293 	}
294 
295 	if (fflags & O_FBLOCKING)
296 		fflags |= lfp->f_flag & ~FNONBLOCK;
297 	else if (fflags & O_FNONBLOCKING)
298 		fflags |= lfp->f_flag | FNONBLOCK;
299 	else
300 		fflags = lfp->f_flag;
301 
302 	if (use_soaccept_pred_fast) {
303 		boolean_t pred;
304 
305 		/* Initialize necessary parts for soaccept_predicate() */
306 		netmsg_init(&msg.base, head, &netisr_apanic_rport, 0, NULL);
307 		msg.nm_fflags = fflags;
308 
309 		lwkt_getpooltoken(head);
310 		pred = soaccept_predicate(&msg);
311 		lwkt_relpooltoken(head);
312 
313 		if (pred) {
314 			error = msg.base.lmsg.ms_error;
315 			if (error)
316 				goto done;
317 			else
318 				goto accepted;
319 		}
320 	}
321 
322 	/* optimize for uniprocessor case later XXX JH */
323 	netmsg_init_abortable(&msg.base, head, &curthread->td_msgport,
324 			      0, netmsg_so_notify, netmsg_so_notify_doabort);
325 	msg.nm_predicate = soaccept_predicate;
326 	msg.nm_fflags = fflags;
327 	msg.nm_etype = NM_REVENT;
328 	error = lwkt_domsg(head->so_port, &msg.base.lmsg, PCATCH);
329 	if (error)
330 		goto done;
331 
332 accepted:
333 	/*
334 	 * At this point we have the connection that's ready to be accepted.
335 	 *
336 	 * NOTE! soaccept_predicate() ref'd so for us, and soaccept() expects
337 	 * 	 to eat the ref and turn it into a descriptor.
338 	 */
339 	so = msg.base.nm_so;
340 
341 	fflag = lfp->f_flag;
342 
343 	/* connection has been removed from the listen queue */
344 	KNOTE(&head->so_rcv.ssb_kq.ki_note, 0);
345 
346 	if (head->so_sigio != NULL)
347 		fsetown(fgetown(&head->so_sigio), &so->so_sigio);
348 
349 	nfp->f_type = DTYPE_SOCKET;
350 	nfp->f_flag = fflag;
351 	nfp->f_ops = &socketops;
352 	nfp->f_data = so;
353 	/* Sync socket nonblocking/async state with file flags */
354 	tmp = fflag & FNONBLOCK;
355 	fo_ioctl(nfp, FIONBIO, (caddr_t)&tmp, td->td_ucred, NULL);
356 	tmp = fflag & FASYNC;
357 	fo_ioctl(nfp, FIOASYNC, (caddr_t)&tmp, td->td_ucred, NULL);
358 
359 	sa = NULL;
360 	if (so->so_faddr != NULL) {
361 		sa = so->so_faddr;
362 		so->so_faddr = NULL;
363 
364 		soaccept_generic(so);
365 		error = 0;
366 	} else {
367 		error = soaccept(so, &sa);
368 	}
369 
370 	/*
371 	 * Set the returned name and namelen as applicable.  Set the returned
372 	 * namelen to 0 for older code which might ignore the return value
373 	 * from accept.
374 	 */
375 	if (error == 0) {
376 		if (sa && name && namelen) {
377 			if (*namelen > sa->sa_len)
378 				*namelen = sa->sa_len;
379 			*name = sa;
380 		} else {
381 			if (sa)
382 				kfree(sa, M_SONAME);
383 		}
384 	}
385 
386 done:
387 	/*
388 	 * If an error occured clear the reserved descriptor, else associate
389 	 * nfp with it.
390 	 *
391 	 * Note that *res is normally ignored if an error is returned but
392 	 * a syscall message will still have access to the result code.
393 	 */
394 	if (error) {
395 		fsetfd(fdp, NULL, fd);
396 	} else {
397 		*res = fd;
398 		fsetfd(fdp, nfp, fd);
399 	}
400 	fdrop(nfp);
401 	fdrop(lfp);
402 	return (error);
403 }
404 
405 /*
406  * accept(int s, caddr_t name, int *anamelen)
407  *
408  * MPALMOSTSAFE
409  */
410 int
411 sys_accept(struct accept_args *uap)
412 {
413 	struct sockaddr *sa = NULL;
414 	int sa_len;
415 	int error;
416 
417 	if (uap->name) {
418 		error = copyin(uap->anamelen, &sa_len, sizeof(sa_len));
419 		if (error)
420 			return (error);
421 
422 		error = kern_accept(uap->s, 0, &sa, &sa_len,
423 				    &uap->sysmsg_iresult);
424 
425 		if (error == 0)
426 			error = copyout(sa, uap->name, sa_len);
427 		if (error == 0) {
428 			error = copyout(&sa_len, uap->anamelen,
429 			    sizeof(*uap->anamelen));
430 		}
431 		if (sa)
432 			kfree(sa, M_SONAME);
433 	} else {
434 		error = kern_accept(uap->s, 0, NULL, 0,
435 				    &uap->sysmsg_iresult);
436 	}
437 	return (error);
438 }
439 
440 /*
441  * extaccept(int s, int fflags, caddr_t name, int *anamelen)
442  *
443  * MPALMOSTSAFE
444  */
445 int
446 sys_extaccept(struct extaccept_args *uap)
447 {
448 	struct sockaddr *sa = NULL;
449 	int sa_len;
450 	int error;
451 	int fflags = uap->flags & O_FMASK;
452 
453 	if (uap->name) {
454 		error = copyin(uap->anamelen, &sa_len, sizeof(sa_len));
455 		if (error)
456 			return (error);
457 
458 		error = kern_accept(uap->s, fflags, &sa, &sa_len,
459 				    &uap->sysmsg_iresult);
460 
461 		if (error == 0)
462 			error = copyout(sa, uap->name, sa_len);
463 		if (error == 0) {
464 			error = copyout(&sa_len, uap->anamelen,
465 			    sizeof(*uap->anamelen));
466 		}
467 		if (sa)
468 			kfree(sa, M_SONAME);
469 	} else {
470 		error = kern_accept(uap->s, fflags, NULL, 0,
471 				    &uap->sysmsg_iresult);
472 	}
473 	return (error);
474 }
475 
476 
477 /*
478  * Returns TRUE if predicate satisfied.
479  */
480 static boolean_t
481 soconnected_predicate(struct netmsg_so_notify *msg)
482 {
483 	struct socket *so = msg->base.nm_so;
484 
485 	/* check predicate */
486 	if (!(so->so_state & SS_ISCONNECTING) || so->so_error != 0) {
487 		msg->base.lmsg.ms_error = so->so_error;
488 		return (TRUE);
489 	}
490 
491 	return (FALSE);
492 }
493 
494 int
495 kern_connect(int s, int fflags, struct sockaddr *sa)
496 {
497 	struct thread *td = curthread;
498 	struct proc *p = td->td_proc;
499 	struct file *fp;
500 	struct socket *so;
501 	int error, interrupted = 0;
502 
503 	error = holdsock(p->p_fd, s, &fp);
504 	if (error)
505 		return (error);
506 	so = (struct socket *)fp->f_data;
507 
508 	if (fflags & O_FBLOCKING)
509 		/* fflags &= ~FNONBLOCK; */;
510 	else if (fflags & O_FNONBLOCKING)
511 		fflags |= FNONBLOCK;
512 	else
513 		fflags = fp->f_flag;
514 
515 	if (so->so_state & SS_ISCONNECTING) {
516 		error = EALREADY;
517 		goto done;
518 	}
519 	error = soconnect(so, sa, td);
520 	if (error)
521 		goto bad;
522 	if ((fflags & FNONBLOCK) && (so->so_state & SS_ISCONNECTING)) {
523 		error = EINPROGRESS;
524 		goto done;
525 	}
526 	if ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
527 		struct netmsg_so_notify msg;
528 
529 		netmsg_init_abortable(&msg.base, so,
530 				      &curthread->td_msgport,
531 				      0,
532 				      netmsg_so_notify,
533 				      netmsg_so_notify_doabort);
534 		msg.nm_predicate = soconnected_predicate;
535 		msg.nm_etype = NM_REVENT;
536 		error = lwkt_domsg(so->so_port, &msg.base.lmsg, PCATCH);
537 		if (error == EINTR || error == ERESTART)
538 			interrupted = 1;
539 	}
540 	if (error == 0) {
541 		error = so->so_error;
542 		so->so_error = 0;
543 	}
544 bad:
545 	if (!interrupted)
546 		soclrstate(so, SS_ISCONNECTING);
547 	if (error == ERESTART)
548 		error = EINTR;
549 done:
550 	fdrop(fp);
551 	return (error);
552 }
553 
554 /*
555  * connect_args(int s, caddr_t name, int namelen)
556  *
557  * MPALMOSTSAFE
558  */
559 int
560 sys_connect(struct connect_args *uap)
561 {
562 	struct sockaddr *sa;
563 	int error;
564 
565 	error = getsockaddr(&sa, uap->name, uap->namelen);
566 	if (error)
567 		return (error);
568 	error = kern_connect(uap->s, 0, sa);
569 	kfree(sa, M_SONAME);
570 
571 	return (error);
572 }
573 
574 /*
575  * connect_args(int s, int fflags, caddr_t name, int namelen)
576  *
577  * MPALMOSTSAFE
578  */
579 int
580 sys_extconnect(struct extconnect_args *uap)
581 {
582 	struct sockaddr *sa;
583 	int error;
584 	int fflags = uap->flags & O_FMASK;
585 
586 	error = getsockaddr(&sa, uap->name, uap->namelen);
587 	if (error)
588 		return (error);
589 	error = kern_connect(uap->s, fflags, sa);
590 	kfree(sa, M_SONAME);
591 
592 	return (error);
593 }
594 
595 int
596 kern_socketpair(int domain, int type, int protocol, int *sv)
597 {
598 	struct thread *td = curthread;
599 	struct filedesc *fdp;
600 	struct file *fp1, *fp2;
601 	struct socket *so1, *so2;
602 	int fd1, fd2, error;
603 
604 	fdp = td->td_proc->p_fd;
605 	error = socreate(domain, &so1, type, protocol, td);
606 	if (error)
607 		return (error);
608 	error = socreate(domain, &so2, type, protocol, td);
609 	if (error)
610 		goto free1;
611 	error = falloc(td->td_lwp, &fp1, &fd1);
612 	if (error)
613 		goto free2;
614 	sv[0] = fd1;
615 	fp1->f_data = so1;
616 	error = falloc(td->td_lwp, &fp2, &fd2);
617 	if (error)
618 		goto free3;
619 	fp2->f_data = so2;
620 	sv[1] = fd2;
621 	error = soconnect2(so1, so2);
622 	if (error)
623 		goto free4;
624 	if (type == SOCK_DGRAM) {
625 		/*
626 		 * Datagram socket connection is asymmetric.
627 		 */
628 		 error = soconnect2(so2, so1);
629 		 if (error)
630 			goto free4;
631 	}
632 	fp1->f_type = fp2->f_type = DTYPE_SOCKET;
633 	fp1->f_flag = fp2->f_flag = FREAD|FWRITE;
634 	fp1->f_ops = fp2->f_ops = &socketops;
635 	fsetfd(fdp, fp1, fd1);
636 	fsetfd(fdp, fp2, fd2);
637 	fdrop(fp1);
638 	fdrop(fp2);
639 	return (error);
640 free4:
641 	fsetfd(fdp, NULL, fd2);
642 	fdrop(fp2);
643 free3:
644 	fsetfd(fdp, NULL, fd1);
645 	fdrop(fp1);
646 free2:
647 	(void)soclose(so2, 0);
648 free1:
649 	(void)soclose(so1, 0);
650 	return (error);
651 }
652 
653 /*
654  * socketpair(int domain, int type, int protocol, int *rsv)
655  */
656 int
657 sys_socketpair(struct socketpair_args *uap)
658 {
659 	int error, sockv[2];
660 
661 	error = kern_socketpair(uap->domain, uap->type, uap->protocol, sockv);
662 
663 	if (error == 0) {
664 		error = copyout(sockv, uap->rsv, sizeof(sockv));
665 
666 		if (error != 0) {
667 			kern_close(sockv[0]);
668 			kern_close(sockv[1]);
669 		}
670 	}
671 
672 	return (error);
673 }
674 
675 int
676 kern_sendmsg(int s, struct sockaddr *sa, struct uio *auio,
677 	     struct mbuf *control, int flags, size_t *res)
678 {
679 	struct thread *td = curthread;
680 	struct lwp *lp = td->td_lwp;
681 	struct proc *p = td->td_proc;
682 	struct file *fp;
683 	size_t len;
684 	int error;
685 	struct socket *so;
686 #ifdef KTRACE
687 	struct iovec *ktriov = NULL;
688 	struct uio ktruio;
689 #endif
690 
691 	error = holdsock(p->p_fd, s, &fp);
692 	if (error)
693 		return (error);
694 #ifdef KTRACE
695 	if (KTRPOINT(td, KTR_GENIO)) {
696 		int iovlen = auio->uio_iovcnt * sizeof (struct iovec);
697 
698 		ktriov = kmalloc(iovlen, M_TEMP, M_WAITOK);
699 		bcopy((caddr_t)auio->uio_iov, (caddr_t)ktriov, iovlen);
700 		ktruio = *auio;
701 	}
702 #endif
703 	len = auio->uio_resid;
704 	so = (struct socket *)fp->f_data;
705 	if ((flags & (MSG_FNONBLOCKING|MSG_FBLOCKING)) == 0) {
706 		if (fp->f_flag & FNONBLOCK)
707 			flags |= MSG_FNONBLOCKING;
708 	}
709 	error = so_pru_sosend(so, sa, auio, NULL, control, flags, td);
710 	if (error) {
711 		if (auio->uio_resid != len && (error == ERESTART ||
712 		    error == EINTR || error == EWOULDBLOCK))
713 			error = 0;
714 		if (error == EPIPE && !(flags & MSG_NOSIGNAL))
715 			lwpsignal(p, lp, SIGPIPE);
716 	}
717 #ifdef KTRACE
718 	if (ktriov != NULL) {
719 		if (error == 0) {
720 			ktruio.uio_iov = ktriov;
721 			ktruio.uio_resid = len - auio->uio_resid;
722 			ktrgenio(lp, s, UIO_WRITE, &ktruio, error);
723 		}
724 		kfree(ktriov, M_TEMP);
725 	}
726 #endif
727 	if (error == 0)
728 		*res  = len - auio->uio_resid;
729 	fdrop(fp);
730 	return (error);
731 }
732 
733 /*
734  * sendto_args(int s, caddr_t buf, size_t len, int flags, caddr_t to, int tolen)
735  *
736  * MPALMOSTSAFE
737  */
738 int
739 sys_sendto(struct sendto_args *uap)
740 {
741 	struct thread *td = curthread;
742 	struct uio auio;
743 	struct iovec aiov;
744 	struct sockaddr *sa = NULL;
745 	int error;
746 
747 	if (uap->to) {
748 		error = getsockaddr(&sa, uap->to, uap->tolen);
749 		if (error)
750 			return (error);
751 	}
752 	aiov.iov_base = uap->buf;
753 	aiov.iov_len = uap->len;
754 	auio.uio_iov = &aiov;
755 	auio.uio_iovcnt = 1;
756 	auio.uio_offset = 0;
757 	auio.uio_resid = uap->len;
758 	auio.uio_segflg = UIO_USERSPACE;
759 	auio.uio_rw = UIO_WRITE;
760 	auio.uio_td = td;
761 
762 	error = kern_sendmsg(uap->s, sa, &auio, NULL, uap->flags,
763 			     &uap->sysmsg_szresult);
764 
765 	if (sa)
766 		kfree(sa, M_SONAME);
767 	return (error);
768 }
769 
770 /*
771  * sendmsg_args(int s, caddr_t msg, int flags)
772  *
773  * MPALMOSTSAFE
774  */
775 int
776 sys_sendmsg(struct sendmsg_args *uap)
777 {
778 	struct thread *td = curthread;
779 	struct msghdr msg;
780 	struct uio auio;
781 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
782 	struct sockaddr *sa = NULL;
783 	struct mbuf *control = NULL;
784 	int error;
785 
786 	error = copyin(uap->msg, (caddr_t)&msg, sizeof(msg));
787 	if (error)
788 		return (error);
789 
790 	/*
791 	 * Conditionally copyin msg.msg_name.
792 	 */
793 	if (msg.msg_name) {
794 		error = getsockaddr(&sa, msg.msg_name, msg.msg_namelen);
795 		if (error)
796 			return (error);
797 	}
798 
799 	/*
800 	 * Populate auio.
801 	 */
802 	error = iovec_copyin(msg.msg_iov, &iov, aiov, msg.msg_iovlen,
803 			     &auio.uio_resid);
804 	if (error)
805 		goto cleanup2;
806 	auio.uio_iov = iov;
807 	auio.uio_iovcnt = msg.msg_iovlen;
808 	auio.uio_offset = 0;
809 	auio.uio_segflg = UIO_USERSPACE;
810 	auio.uio_rw = UIO_WRITE;
811 	auio.uio_td = td;
812 
813 	/*
814 	 * Conditionally copyin msg.msg_control.
815 	 */
816 	if (msg.msg_control) {
817 		if (msg.msg_controllen < sizeof(struct cmsghdr) ||
818 		    msg.msg_controllen > MLEN) {
819 			error = EINVAL;
820 			goto cleanup;
821 		}
822 		control = m_get(MB_WAIT, MT_CONTROL);
823 		if (control == NULL) {
824 			error = ENOBUFS;
825 			goto cleanup;
826 		}
827 		control->m_len = msg.msg_controllen;
828 		error = copyin(msg.msg_control, mtod(control, caddr_t),
829 			       msg.msg_controllen);
830 		if (error) {
831 			m_free(control);
832 			goto cleanup;
833 		}
834 	}
835 
836 	error = kern_sendmsg(uap->s, sa, &auio, control, uap->flags,
837 			     &uap->sysmsg_szresult);
838 
839 cleanup:
840 	iovec_free(&iov, aiov);
841 cleanup2:
842 	if (sa)
843 		kfree(sa, M_SONAME);
844 	return (error);
845 }
846 
847 /*
848  * kern_recvmsg() takes a handle to sa and control.  If the handle is non-
849  * null, it returns a dynamically allocated struct sockaddr and an mbuf.
850  * Don't forget to FREE() and m_free() these if they are returned.
851  */
852 int
853 kern_recvmsg(int s, struct sockaddr **sa, struct uio *auio,
854 	     struct mbuf **control, int *flags, size_t *res)
855 {
856 	struct thread *td = curthread;
857 	struct proc *p = td->td_proc;
858 	struct file *fp;
859 	size_t len;
860 	int error;
861 	int lflags;
862 	struct socket *so;
863 #ifdef KTRACE
864 	struct iovec *ktriov = NULL;
865 	struct uio ktruio;
866 #endif
867 
868 	error = holdsock(p->p_fd, s, &fp);
869 	if (error)
870 		return (error);
871 #ifdef KTRACE
872 	if (KTRPOINT(td, KTR_GENIO)) {
873 		int iovlen = auio->uio_iovcnt * sizeof (struct iovec);
874 
875 		ktriov = kmalloc(iovlen, M_TEMP, M_WAITOK);
876 		bcopy(auio->uio_iov, ktriov, iovlen);
877 		ktruio = *auio;
878 	}
879 #endif
880 	len = auio->uio_resid;
881 	so = (struct socket *)fp->f_data;
882 
883 	if (flags == NULL || (*flags & (MSG_FNONBLOCKING|MSG_FBLOCKING)) == 0) {
884 		if (fp->f_flag & FNONBLOCK) {
885 			if (flags) {
886 				*flags |= MSG_FNONBLOCKING;
887 			} else {
888 				lflags = MSG_FNONBLOCKING;
889 				flags = &lflags;
890 			}
891 		}
892 	}
893 
894 	error = so_pru_soreceive(so, sa, auio, NULL, control, flags);
895 	if (error) {
896 		if (auio->uio_resid != len && (error == ERESTART ||
897 		    error == EINTR || error == EWOULDBLOCK))
898 			error = 0;
899 	}
900 #ifdef KTRACE
901 	if (ktriov != NULL) {
902 		if (error == 0) {
903 			ktruio.uio_iov = ktriov;
904 			ktruio.uio_resid = len - auio->uio_resid;
905 			ktrgenio(td->td_lwp, s, UIO_READ, &ktruio, error);
906 		}
907 		kfree(ktriov, M_TEMP);
908 	}
909 #endif
910 	if (error == 0)
911 		*res = len - auio->uio_resid;
912 	fdrop(fp);
913 	return (error);
914 }
915 
916 /*
917  * recvfrom_args(int s, caddr_t buf, size_t len, int flags,
918  *			caddr_t from, int *fromlenaddr)
919  *
920  * MPALMOSTSAFE
921  */
922 int
923 sys_recvfrom(struct recvfrom_args *uap)
924 {
925 	struct thread *td = curthread;
926 	struct uio auio;
927 	struct iovec aiov;
928 	struct sockaddr *sa = NULL;
929 	int error, fromlen;
930 
931 	if (uap->from && uap->fromlenaddr) {
932 		error = copyin(uap->fromlenaddr, &fromlen, sizeof(fromlen));
933 		if (error)
934 			return (error);
935 		if (fromlen < 0)
936 			return (EINVAL);
937 	} else {
938 		fromlen = 0;
939 	}
940 	aiov.iov_base = uap->buf;
941 	aiov.iov_len = uap->len;
942 	auio.uio_iov = &aiov;
943 	auio.uio_iovcnt = 1;
944 	auio.uio_offset = 0;
945 	auio.uio_resid = uap->len;
946 	auio.uio_segflg = UIO_USERSPACE;
947 	auio.uio_rw = UIO_READ;
948 	auio.uio_td = td;
949 
950 	error = kern_recvmsg(uap->s, uap->from ? &sa : NULL, &auio, NULL,
951 			     &uap->flags, &uap->sysmsg_szresult);
952 
953 	if (error == 0 && uap->from) {
954 		/* note: sa may still be NULL */
955 		if (sa) {
956 			fromlen = MIN(fromlen, sa->sa_len);
957 			error = copyout(sa, uap->from, fromlen);
958 		} else {
959 			fromlen = 0;
960 		}
961 		if (error == 0) {
962 			error = copyout(&fromlen, uap->fromlenaddr,
963 					sizeof(fromlen));
964 		}
965 	}
966 	if (sa)
967 		kfree(sa, M_SONAME);
968 
969 	return (error);
970 }
971 
972 /*
973  * recvmsg_args(int s, struct msghdr *msg, int flags)
974  *
975  * MPALMOSTSAFE
976  */
977 int
978 sys_recvmsg(struct recvmsg_args *uap)
979 {
980 	struct thread *td = curthread;
981 	struct msghdr msg;
982 	struct uio auio;
983 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
984 	struct mbuf *m, *control = NULL;
985 	struct sockaddr *sa = NULL;
986 	caddr_t ctlbuf;
987 	socklen_t *ufromlenp, *ucontrollenp;
988 	int error, fromlen, controllen, len, flags, *uflagsp;
989 
990 	/*
991 	 * This copyin handles everything except the iovec.
992 	 */
993 	error = copyin(uap->msg, &msg, sizeof(msg));
994 	if (error)
995 		return (error);
996 
997 	if (msg.msg_name && msg.msg_namelen < 0)
998 		return (EINVAL);
999 	if (msg.msg_control && msg.msg_controllen < 0)
1000 		return (EINVAL);
1001 
1002 	ufromlenp = (socklen_t *)((caddr_t)uap->msg + offsetof(struct msghdr,
1003 		    msg_namelen));
1004 	ucontrollenp = (socklen_t *)((caddr_t)uap->msg + offsetof(struct msghdr,
1005 		       msg_controllen));
1006 	uflagsp = (int *)((caddr_t)uap->msg + offsetof(struct msghdr,
1007 							msg_flags));
1008 
1009 	/*
1010 	 * Populate auio.
1011 	 */
1012 	error = iovec_copyin(msg.msg_iov, &iov, aiov, msg.msg_iovlen,
1013 			     &auio.uio_resid);
1014 	if (error)
1015 		return (error);
1016 	auio.uio_iov = iov;
1017 	auio.uio_iovcnt = msg.msg_iovlen;
1018 	auio.uio_offset = 0;
1019 	auio.uio_segflg = UIO_USERSPACE;
1020 	auio.uio_rw = UIO_READ;
1021 	auio.uio_td = td;
1022 
1023 	flags = uap->flags;
1024 
1025 	error = kern_recvmsg(uap->s,
1026 			     (msg.msg_name ? &sa : NULL), &auio,
1027 			     (msg.msg_control ? &control : NULL), &flags,
1028 			     &uap->sysmsg_szresult);
1029 
1030 	/*
1031 	 * Conditionally copyout the name and populate the namelen field.
1032 	 */
1033 	if (error == 0 && msg.msg_name) {
1034 		/* note: sa may still be NULL */
1035 		if (sa != NULL) {
1036 			fromlen = MIN(msg.msg_namelen, sa->sa_len);
1037 			error = copyout(sa, msg.msg_name, fromlen);
1038 		} else {
1039 			fromlen = 0;
1040 		}
1041 		if (error == 0)
1042 			error = copyout(&fromlen, ufromlenp,
1043 			    sizeof(*ufromlenp));
1044 	}
1045 
1046 	/*
1047 	 * Copyout msg.msg_control and msg.msg_controllen.
1048 	 */
1049 	if (error == 0 && msg.msg_control) {
1050 		len = msg.msg_controllen;
1051 		m = control;
1052 		ctlbuf = (caddr_t)msg.msg_control;
1053 
1054 		while(m && len > 0) {
1055 			unsigned int tocopy;
1056 
1057 			if (len >= m->m_len) {
1058 				tocopy = m->m_len;
1059 			} else {
1060 				msg.msg_flags |= MSG_CTRUNC;
1061 				tocopy = len;
1062 			}
1063 
1064 			error = copyout(mtod(m, caddr_t), ctlbuf, tocopy);
1065 			if (error)
1066 				goto cleanup;
1067 
1068 			ctlbuf += tocopy;
1069 			len -= tocopy;
1070 			m = m->m_next;
1071 		}
1072 		controllen = ctlbuf - (caddr_t)msg.msg_control;
1073 		error = copyout(&controllen, ucontrollenp,
1074 		    sizeof(*ucontrollenp));
1075 	}
1076 
1077 	if (error == 0)
1078 		error = copyout(&flags, uflagsp, sizeof(*uflagsp));
1079 
1080 cleanup:
1081 	if (sa)
1082 		kfree(sa, M_SONAME);
1083 	iovec_free(&iov, aiov);
1084 	if (control)
1085 		m_freem(control);
1086 	return (error);
1087 }
1088 
1089 /*
1090  * If sopt->sopt_td == NULL, then sopt->sopt_val is treated as an
1091  * in kernel pointer instead of a userland pointer.  This allows us
1092  * to manipulate socket options in the emulation code.
1093  */
1094 int
1095 kern_setsockopt(int s, struct sockopt *sopt)
1096 {
1097 	struct thread *td = curthread;
1098 	struct proc *p = td->td_proc;
1099 	struct file *fp;
1100 	int error;
1101 
1102 	if (sopt->sopt_val == NULL && sopt->sopt_valsize != 0)
1103 		return (EFAULT);
1104 	if (sopt->sopt_val != NULL && sopt->sopt_valsize == 0)
1105 		return (EINVAL);
1106 	if (sopt->sopt_valsize > SOMAXOPT_SIZE)	/* unsigned */
1107 		return (EINVAL);
1108 
1109 	error = holdsock(p->p_fd, s, &fp);
1110 	if (error)
1111 		return (error);
1112 
1113 	error = sosetopt((struct socket *)fp->f_data, sopt);
1114 	fdrop(fp);
1115 	return (error);
1116 }
1117 
1118 /*
1119  * setsockopt_args(int s, int level, int name, caddr_t val, int valsize)
1120  *
1121  * MPALMOSTSAFE
1122  */
1123 int
1124 sys_setsockopt(struct setsockopt_args *uap)
1125 {
1126 	struct thread *td = curthread;
1127 	struct sockopt sopt;
1128 	int error;
1129 
1130 	sopt.sopt_level = uap->level;
1131 	sopt.sopt_name = uap->name;
1132 	sopt.sopt_valsize = uap->valsize;
1133 	sopt.sopt_td = td;
1134 	sopt.sopt_val = NULL;
1135 
1136 	if (sopt.sopt_valsize > SOMAXOPT_SIZE) /* unsigned */
1137 		return (EINVAL);
1138 	if (uap->val) {
1139 		sopt.sopt_val = kmalloc(sopt.sopt_valsize, M_TEMP, M_WAITOK);
1140 		error = copyin(uap->val, sopt.sopt_val, sopt.sopt_valsize);
1141 		if (error)
1142 			goto out;
1143 	}
1144 
1145 	error = kern_setsockopt(uap->s, &sopt);
1146 out:
1147 	if (uap->val)
1148 		kfree(sopt.sopt_val, M_TEMP);
1149 	return(error);
1150 }
1151 
1152 /*
1153  * If sopt->sopt_td == NULL, then sopt->sopt_val is treated as an
1154  * in kernel pointer instead of a userland pointer.  This allows us
1155  * to manipulate socket options in the emulation code.
1156  */
1157 int
1158 kern_getsockopt(int s, struct sockopt *sopt)
1159 {
1160 	struct thread *td = curthread;
1161 	struct proc *p = td->td_proc;
1162 	struct file *fp;
1163 	int error;
1164 
1165 	if (sopt->sopt_val == NULL && sopt->sopt_valsize != 0)
1166 		return (EFAULT);
1167 	if (sopt->sopt_val != NULL && sopt->sopt_valsize == 0)
1168 		return (EINVAL);
1169 	if (sopt->sopt_valsize > SOMAXOPT_SIZE) /* unsigned */
1170 		return (EINVAL);
1171 
1172 	error = holdsock(p->p_fd, s, &fp);
1173 	if (error)
1174 		return (error);
1175 
1176 	error = sogetopt((struct socket *)fp->f_data, sopt);
1177 	fdrop(fp);
1178 	return (error);
1179 }
1180 
1181 /*
1182  * getsockopt_args(int s, int level, int name, caddr_t val, int *avalsize)
1183  *
1184  * MPALMOSTSAFE
1185  */
1186 int
1187 sys_getsockopt(struct getsockopt_args *uap)
1188 {
1189 	struct thread *td = curthread;
1190 	struct	sockopt sopt;
1191 	int	error, valsize;
1192 
1193 	if (uap->val) {
1194 		error = copyin(uap->avalsize, &valsize, sizeof(valsize));
1195 		if (error)
1196 			return (error);
1197 	} else {
1198 		valsize = 0;
1199 	}
1200 
1201 	sopt.sopt_level = uap->level;
1202 	sopt.sopt_name = uap->name;
1203 	sopt.sopt_valsize = valsize;
1204 	sopt.sopt_td = td;
1205 	sopt.sopt_val = NULL;
1206 
1207 	if (sopt.sopt_valsize > SOMAXOPT_SIZE) /* unsigned */
1208 		return (EINVAL);
1209 	if (uap->val) {
1210 		sopt.sopt_val = kmalloc(sopt.sopt_valsize, M_TEMP, M_WAITOK);
1211 		error = copyin(uap->val, sopt.sopt_val, sopt.sopt_valsize);
1212 		if (error)
1213 			goto out;
1214 	}
1215 
1216 	error = kern_getsockopt(uap->s, &sopt);
1217 	if (error)
1218 		goto out;
1219 	valsize = sopt.sopt_valsize;
1220 	error = copyout(&valsize, uap->avalsize, sizeof(valsize));
1221 	if (error)
1222 		goto out;
1223 	if (uap->val)
1224 		error = copyout(sopt.sopt_val, uap->val, sopt.sopt_valsize);
1225 out:
1226 	if (uap->val)
1227 		kfree(sopt.sopt_val, M_TEMP);
1228 	return (error);
1229 }
1230 
1231 /*
1232  * The second argument to kern_getsockname() is a handle to a struct sockaddr.
1233  * This allows kern_getsockname() to return a pointer to an allocated struct
1234  * sockaddr which must be freed later with FREE().  The caller must
1235  * initialize *name to NULL.
1236  */
1237 int
1238 kern_getsockname(int s, struct sockaddr **name, int *namelen)
1239 {
1240 	struct thread *td = curthread;
1241 	struct proc *p = td->td_proc;
1242 	struct file *fp;
1243 	struct socket *so;
1244 	struct sockaddr *sa = NULL;
1245 	int error;
1246 
1247 	error = holdsock(p->p_fd, s, &fp);
1248 	if (error)
1249 		return (error);
1250 	if (*namelen < 0) {
1251 		fdrop(fp);
1252 		return (EINVAL);
1253 	}
1254 	so = (struct socket *)fp->f_data;
1255 	error = so_pru_sockaddr(so, &sa);
1256 	if (error == 0) {
1257 		if (sa == NULL) {
1258 			*namelen = 0;
1259 		} else {
1260 			*namelen = MIN(*namelen, sa->sa_len);
1261 			*name = sa;
1262 		}
1263 	}
1264 
1265 	fdrop(fp);
1266 	return (error);
1267 }
1268 
1269 /*
1270  * getsockname_args(int fdes, caddr_t asa, int *alen)
1271  *
1272  * Get socket name.
1273  *
1274  * MPALMOSTSAFE
1275  */
1276 int
1277 sys_getsockname(struct getsockname_args *uap)
1278 {
1279 	struct sockaddr *sa = NULL;
1280 	int error, sa_len;
1281 
1282 	error = copyin(uap->alen, &sa_len, sizeof(sa_len));
1283 	if (error)
1284 		return (error);
1285 
1286 	error = kern_getsockname(uap->fdes, &sa, &sa_len);
1287 
1288 	if (error == 0)
1289 		error = copyout(sa, uap->asa, sa_len);
1290 	if (error == 0)
1291 		error = copyout(&sa_len, uap->alen, sizeof(*uap->alen));
1292 	if (sa)
1293 		kfree(sa, M_SONAME);
1294 	return (error);
1295 }
1296 
1297 /*
1298  * The second argument to kern_getpeername() is a handle to a struct sockaddr.
1299  * This allows kern_getpeername() to return a pointer to an allocated struct
1300  * sockaddr which must be freed later with FREE().  The caller must
1301  * initialize *name to NULL.
1302  */
1303 int
1304 kern_getpeername(int s, struct sockaddr **name, int *namelen)
1305 {
1306 	struct thread *td = curthread;
1307 	struct proc *p = td->td_proc;
1308 	struct file *fp;
1309 	struct socket *so;
1310 	struct sockaddr *sa = NULL;
1311 	int error;
1312 
1313 	error = holdsock(p->p_fd, s, &fp);
1314 	if (error)
1315 		return (error);
1316 	if (*namelen < 0) {
1317 		fdrop(fp);
1318 		return (EINVAL);
1319 	}
1320 	so = (struct socket *)fp->f_data;
1321 	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
1322 		fdrop(fp);
1323 		return (ENOTCONN);
1324 	}
1325 	error = so_pru_peeraddr(so, &sa);
1326 	if (error == 0) {
1327 		if (sa == NULL) {
1328 			*namelen = 0;
1329 		} else {
1330 			*namelen = MIN(*namelen, sa->sa_len);
1331 			*name = sa;
1332 		}
1333 	}
1334 
1335 	fdrop(fp);
1336 	return (error);
1337 }
1338 
1339 /*
1340  * getpeername_args(int fdes, caddr_t asa, int *alen)
1341  *
1342  * Get name of peer for connected socket.
1343  *
1344  * MPALMOSTSAFE
1345  */
1346 int
1347 sys_getpeername(struct getpeername_args *uap)
1348 {
1349 	struct sockaddr *sa = NULL;
1350 	int error, sa_len;
1351 
1352 	error = copyin(uap->alen, &sa_len, sizeof(sa_len));
1353 	if (error)
1354 		return (error);
1355 
1356 	error = kern_getpeername(uap->fdes, &sa, &sa_len);
1357 
1358 	if (error == 0)
1359 		error = copyout(sa, uap->asa, sa_len);
1360 	if (error == 0)
1361 		error = copyout(&sa_len, uap->alen, sizeof(*uap->alen));
1362 	if (sa)
1363 		kfree(sa, M_SONAME);
1364 	return (error);
1365 }
1366 
1367 int
1368 getsockaddr(struct sockaddr **namp, caddr_t uaddr, size_t len)
1369 {
1370 	struct sockaddr *sa;
1371 	int error;
1372 
1373 	*namp = NULL;
1374 	if (len > SOCK_MAXADDRLEN)
1375 		return ENAMETOOLONG;
1376 	if (len < offsetof(struct sockaddr, sa_data[0]))
1377 		return EDOM;
1378 	sa = kmalloc(len, M_SONAME, M_WAITOK);
1379 	error = copyin(uaddr, sa, len);
1380 	if (error) {
1381 		kfree(sa, M_SONAME);
1382 	} else {
1383 #if BYTE_ORDER != BIG_ENDIAN
1384 		/*
1385 		 * The bind(), connect(), and sendto() syscalls were not
1386 		 * versioned for COMPAT_43.  Thus, this check must stay.
1387 		 */
1388 		if (sa->sa_family == 0 && sa->sa_len < AF_MAX)
1389 			sa->sa_family = sa->sa_len;
1390 #endif
1391 		sa->sa_len = len;
1392 		*namp = sa;
1393 	}
1394 	return error;
1395 }
1396 
1397 /*
1398  * Detach a mapped page and release resources back to the system.
1399  * We must release our wiring and if the object is ripped out
1400  * from under the vm_page we become responsible for freeing the
1401  * page.
1402  *
1403  * MPSAFE
1404  */
1405 static void
1406 sf_buf_mfree(void *arg)
1407 {
1408 	struct sf_buf *sf = arg;
1409 	vm_page_t m;
1410 
1411 	m = sf_buf_page(sf);
1412 	if (sf_buf_free(sf)) {
1413 		/* sf invalid now */
1414 		vm_page_busy_wait(m, FALSE, "sockpgf");
1415 		vm_page_unwire(m, 0);
1416 		if (m->object == NULL &&
1417 		    m->wire_count == 0 &&
1418 		    (m->flags & PG_NEED_COMMIT) == 0) {
1419 			vm_page_free(m);
1420 		} else {
1421 			vm_page_wakeup(m);
1422 		}
1423 	}
1424 }
1425 
1426 /*
1427  * sendfile(2).
1428  * int sendfile(int fd, int s, off_t offset, size_t nbytes,
1429  *	 struct sf_hdtr *hdtr, off_t *sbytes, int flags)
1430  *
1431  * Send a file specified by 'fd' and starting at 'offset' to a socket
1432  * specified by 's'. Send only 'nbytes' of the file or until EOF if
1433  * nbytes == 0. Optionally add a header and/or trailer to the socket
1434  * output. If specified, write the total number of bytes sent into *sbytes.
1435  *
1436  * In FreeBSD kern/uipc_syscalls.c,v 1.103, a bug was fixed that caused
1437  * the headers to count against the remaining bytes to be sent from
1438  * the file descriptor.  We may wish to implement a compatibility syscall
1439  * in the future.
1440  *
1441  * MPALMOSTSAFE
1442  */
1443 int
1444 sys_sendfile(struct sendfile_args *uap)
1445 {
1446 	struct thread *td = curthread;
1447 	struct proc *p = td->td_proc;
1448 	struct file *fp;
1449 	struct vnode *vp = NULL;
1450 	struct sf_hdtr hdtr;
1451 	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
1452 	struct uio auio;
1453 	struct mbuf *mheader = NULL;
1454 	size_t hbytes = 0;
1455 	size_t tbytes;
1456 	off_t hdtr_size = 0;
1457 	off_t sbytes;
1458 	int error;
1459 
1460 	KKASSERT(p);
1461 
1462 	/*
1463 	 * Do argument checking. Must be a regular file in, stream
1464 	 * type and connected socket out, positive offset.
1465 	 */
1466 	fp = holdfp(p->p_fd, uap->fd, FREAD);
1467 	if (fp == NULL) {
1468 		return (EBADF);
1469 	}
1470 	if (fp->f_type != DTYPE_VNODE) {
1471 		fdrop(fp);
1472 		return (EINVAL);
1473 	}
1474 	vp = (struct vnode *)fp->f_data;
1475 	vref(vp);
1476 	fdrop(fp);
1477 
1478 	/*
1479 	 * If specified, get the pointer to the sf_hdtr struct for
1480 	 * any headers/trailers.
1481 	 */
1482 	if (uap->hdtr) {
1483 		error = copyin(uap->hdtr, &hdtr, sizeof(hdtr));
1484 		if (error)
1485 			goto done;
1486 		/*
1487 		 * Send any headers.
1488 		 */
1489 		if (hdtr.headers) {
1490 			error = iovec_copyin(hdtr.headers, &iov, aiov,
1491 					     hdtr.hdr_cnt, &hbytes);
1492 			if (error)
1493 				goto done;
1494 			auio.uio_iov = iov;
1495 			auio.uio_iovcnt = hdtr.hdr_cnt;
1496 			auio.uio_offset = 0;
1497 			auio.uio_segflg = UIO_USERSPACE;
1498 			auio.uio_rw = UIO_WRITE;
1499 			auio.uio_td = td;
1500 			auio.uio_resid = hbytes;
1501 
1502 			mheader = m_uiomove(&auio);
1503 
1504 			iovec_free(&iov, aiov);
1505 			if (mheader == NULL)
1506 				goto done;
1507 		}
1508 	}
1509 
1510 	error = kern_sendfile(vp, uap->s, uap->offset, uap->nbytes, mheader,
1511 			      &sbytes, uap->flags);
1512 	if (error)
1513 		goto done;
1514 
1515 	/*
1516 	 * Send trailers. Wimp out and use writev(2).
1517 	 */
1518 	if (uap->hdtr != NULL && hdtr.trailers != NULL) {
1519 		error = iovec_copyin(hdtr.trailers, &iov, aiov,
1520 				     hdtr.trl_cnt, &auio.uio_resid);
1521 		if (error)
1522 			goto done;
1523 		auio.uio_iov = iov;
1524 		auio.uio_iovcnt = hdtr.trl_cnt;
1525 		auio.uio_offset = 0;
1526 		auio.uio_segflg = UIO_USERSPACE;
1527 		auio.uio_rw = UIO_WRITE;
1528 		auio.uio_td = td;
1529 
1530 		error = kern_sendmsg(uap->s, NULL, &auio, NULL, 0, &tbytes);
1531 
1532 		iovec_free(&iov, aiov);
1533 		if (error)
1534 			goto done;
1535 		hdtr_size += tbytes;	/* trailer bytes successfully sent */
1536 	}
1537 
1538 done:
1539 	if (vp)
1540 		vrele(vp);
1541 	if (uap->sbytes != NULL) {
1542 		sbytes += hdtr_size;
1543 		copyout(&sbytes, uap->sbytes, sizeof(off_t));
1544 	}
1545 	return (error);
1546 }
1547 
1548 int
1549 kern_sendfile(struct vnode *vp, int sfd, off_t offset, size_t nbytes,
1550 	      struct mbuf *mheader, off_t *sbytes, int flags)
1551 {
1552 	struct thread *td = curthread;
1553 	struct proc *p = td->td_proc;
1554 	struct vm_object *obj;
1555 	struct socket *so;
1556 	struct file *fp;
1557 	struct mbuf *m, *mp;
1558 	struct sf_buf *sf;
1559 	struct vm_page *pg;
1560 	off_t off, xfsize;
1561 	off_t hbytes = 0;
1562 	int error = 0;
1563 
1564 	if (vp->v_type != VREG) {
1565 		error = EINVAL;
1566 		goto done0;
1567 	}
1568 	if ((obj = vp->v_object) == NULL) {
1569 		error = EINVAL;
1570 		goto done0;
1571 	}
1572 	error = holdsock(p->p_fd, sfd, &fp);
1573 	if (error)
1574 		goto done0;
1575 	so = (struct socket *)fp->f_data;
1576 	if (so->so_type != SOCK_STREAM) {
1577 		error = EINVAL;
1578 		goto done;
1579 	}
1580 	if ((so->so_state & SS_ISCONNECTED) == 0) {
1581 		error = ENOTCONN;
1582 		goto done;
1583 	}
1584 	if (offset < 0) {
1585 		error = EINVAL;
1586 		goto done;
1587 	}
1588 
1589 	*sbytes = 0;
1590 	/*
1591 	 * Protect against multiple writers to the socket.
1592 	 */
1593 	ssb_lock(&so->so_snd, M_WAITOK);
1594 
1595 	/*
1596 	 * Loop through the pages in the file, starting with the requested
1597 	 * offset. Get a file page (do I/O if necessary), map the file page
1598 	 * into an sf_buf, attach an mbuf header to the sf_buf, and queue
1599 	 * it on the socket.
1600 	 */
1601 	for (off = offset; ; off += xfsize, *sbytes += xfsize + hbytes) {
1602 		vm_pindex_t pindex;
1603 		vm_offset_t pgoff;
1604 		int space;
1605 
1606 		pindex = OFF_TO_IDX(off);
1607 retry_lookup:
1608 		/*
1609 		 * Calculate the amount to transfer. Not to exceed a page,
1610 		 * the EOF, or the passed in nbytes.
1611 		 */
1612 		xfsize = vp->v_filesize - off;
1613 		if (xfsize > PAGE_SIZE)
1614 			xfsize = PAGE_SIZE;
1615 		pgoff = (vm_offset_t)(off & PAGE_MASK);
1616 		if (PAGE_SIZE - pgoff < xfsize)
1617 			xfsize = PAGE_SIZE - pgoff;
1618 		if (nbytes && xfsize > (nbytes - *sbytes))
1619 			xfsize = nbytes - *sbytes;
1620 		if (xfsize <= 0)
1621 			break;
1622 		/*
1623 		 * Optimize the non-blocking case by looking at the socket space
1624 		 * before going to the extra work of constituting the sf_buf.
1625 		 */
1626 		if ((fp->f_flag & FNONBLOCK) &&
1627 		    ssb_space_prealloc(&so->so_snd) <= 0) {
1628 			if (so->so_state & SS_CANTSENDMORE)
1629 				error = EPIPE;
1630 			else
1631 				error = EAGAIN;
1632 			ssb_unlock(&so->so_snd);
1633 			goto done;
1634 		}
1635 		/*
1636 		 * Attempt to look up the page.
1637 		 *
1638 		 *	Allocate if not found, wait and loop if busy, then
1639 		 *	wire the page.  critical section protection is
1640 		 * 	required to maintain the object association (an
1641 		 *	interrupt can free the page) through to the
1642 		 *	vm_page_wire() call.
1643 		 */
1644 		vm_object_hold(obj);
1645 		pg = vm_page_lookup_busy_try(obj, pindex, TRUE, &error);
1646 		if (error) {
1647 			vm_page_sleep_busy(pg, TRUE, "sfpbsy");
1648 			vm_object_drop(obj);
1649 			goto retry_lookup;
1650 		}
1651 		if (pg == NULL) {
1652 			pg = vm_page_alloc(obj, pindex, VM_ALLOC_NORMAL |
1653 							VM_ALLOC_NULL_OK);
1654 			if (pg == NULL) {
1655 				vm_wait(0);
1656 				vm_object_drop(obj);
1657 				goto retry_lookup;
1658 			}
1659 		}
1660 		vm_page_wire(pg);
1661 		vm_object_drop(obj);
1662 
1663 		/*
1664 		 * If page is not valid for what we need, initiate I/O
1665 		 */
1666 
1667 		if (!pg->valid || !vm_page_is_valid(pg, pgoff, xfsize)) {
1668 			struct uio auio;
1669 			struct iovec aiov;
1670 			int bsize;
1671 
1672 			/*
1673 			 * Ensure that our page is still around when the I/O
1674 			 * completes.
1675 			 */
1676 			vm_page_io_start(pg);
1677 			vm_page_wakeup(pg);
1678 
1679 			/*
1680 			 * Get the page from backing store.
1681 			 */
1682 			bsize = vp->v_mount->mnt_stat.f_iosize;
1683 			auio.uio_iov = &aiov;
1684 			auio.uio_iovcnt = 1;
1685 			aiov.iov_base = 0;
1686 			aiov.iov_len = MAXBSIZE;
1687 			auio.uio_resid = MAXBSIZE;
1688 			auio.uio_offset = trunc_page(off);
1689 			auio.uio_segflg = UIO_NOCOPY;
1690 			auio.uio_rw = UIO_READ;
1691 			auio.uio_td = td;
1692 			vn_lock(vp, LK_SHARED | LK_RETRY);
1693 			error = VOP_READ(vp, &auio,
1694 				    IO_VMIO | ((MAXBSIZE / bsize) << 16),
1695 				    td->td_ucred);
1696 			vn_unlock(vp);
1697 			vm_page_flag_clear(pg, PG_ZERO);
1698 			vm_page_busy_wait(pg, FALSE, "sockpg");
1699 			vm_page_io_finish(pg);
1700 			if (error) {
1701 				vm_page_unwire(pg, 0);
1702 				vm_page_wakeup(pg);
1703 				vm_page_try_to_free(pg);
1704 				ssb_unlock(&so->so_snd);
1705 				goto done;
1706 			}
1707 		}
1708 
1709 
1710 		/*
1711 		 * Get a sendfile buf. We usually wait as long as necessary,
1712 		 * but this wait can be interrupted.
1713 		 */
1714 		if ((sf = sf_buf_alloc(pg)) == NULL) {
1715 			vm_page_unwire(pg, 0);
1716 			vm_page_wakeup(pg);
1717 			vm_page_try_to_free(pg);
1718 			ssb_unlock(&so->so_snd);
1719 			error = EINTR;
1720 			goto done;
1721 		}
1722 		vm_page_wakeup(pg);
1723 
1724 		/*
1725 		 * Get an mbuf header and set it up as having external storage.
1726 		 */
1727 		MGETHDR(m, MB_WAIT, MT_DATA);
1728 		if (m == NULL) {
1729 			error = ENOBUFS;
1730 			sf_buf_free(sf);
1731 			ssb_unlock(&so->so_snd);
1732 			goto done;
1733 		}
1734 
1735 		m->m_ext.ext_free = sf_buf_mfree;
1736 		m->m_ext.ext_ref = sf_buf_ref;
1737 		m->m_ext.ext_arg = sf;
1738 		m->m_ext.ext_buf = (void *)sf_buf_kva(sf);
1739 		m->m_ext.ext_size = PAGE_SIZE;
1740 		m->m_data = (char *)sf_buf_kva(sf) + pgoff;
1741 		m->m_flags |= M_EXT;
1742 		m->m_pkthdr.len = m->m_len = xfsize;
1743 		KKASSERT((m->m_flags & (M_EXT_CLUSTER)) == 0);
1744 
1745 		if (mheader != NULL) {
1746 			hbytes = mheader->m_pkthdr.len;
1747 			mheader->m_pkthdr.len += m->m_pkthdr.len;
1748 			m_cat(mheader, m);
1749 			m = mheader;
1750 			mheader = NULL;
1751 		} else
1752 			hbytes = 0;
1753 
1754 		/*
1755 		 * Add the buffer to the socket buffer chain.
1756 		 */
1757 		crit_enter();
1758 retry_space:
1759 		/*
1760 		 * Make sure that the socket is still able to take more data.
1761 		 * CANTSENDMORE being true usually means that the connection
1762 		 * was closed. so_error is true when an error was sensed after
1763 		 * a previous send.
1764 		 * The state is checked after the page mapping and buffer
1765 		 * allocation above since those operations may block and make
1766 		 * any socket checks stale. From this point forward, nothing
1767 		 * blocks before the pru_send (or more accurately, any blocking
1768 		 * results in a loop back to here to re-check).
1769 		 */
1770 		if ((so->so_state & SS_CANTSENDMORE) || so->so_error) {
1771 			if (so->so_state & SS_CANTSENDMORE) {
1772 				error = EPIPE;
1773 			} else {
1774 				error = so->so_error;
1775 				so->so_error = 0;
1776 			}
1777 			m_freem(m);
1778 			ssb_unlock(&so->so_snd);
1779 			crit_exit();
1780 			goto done;
1781 		}
1782 		/*
1783 		 * Wait for socket space to become available. We do this just
1784 		 * after checking the connection state above in order to avoid
1785 		 * a race condition with ssb_wait().
1786 		 */
1787 		space = ssb_space_prealloc(&so->so_snd);
1788 		if (space < m->m_pkthdr.len && space < so->so_snd.ssb_lowat) {
1789 			if (fp->f_flag & FNONBLOCK) {
1790 				m_freem(m);
1791 				ssb_unlock(&so->so_snd);
1792 				crit_exit();
1793 				error = EAGAIN;
1794 				goto done;
1795 			}
1796 			error = ssb_wait(&so->so_snd);
1797 			/*
1798 			 * An error from ssb_wait usually indicates that we've
1799 			 * been interrupted by a signal. If we've sent anything
1800 			 * then return bytes sent, otherwise return the error.
1801 			 */
1802 			if (error) {
1803 				m_freem(m);
1804 				ssb_unlock(&so->so_snd);
1805 				crit_exit();
1806 				goto done;
1807 			}
1808 			goto retry_space;
1809 		}
1810 
1811 		for (mp = m; mp != NULL; mp = mp->m_next)
1812 			ssb_preallocstream(&so->so_snd, mp);
1813 		if (use_sendfile_async)
1814 			error = so_pru_senda(so, 0, m, NULL, NULL, td);
1815 		else
1816 			error = so_pru_send(so, 0, m, NULL, NULL, td);
1817 
1818 		crit_exit();
1819 		if (error) {
1820 			ssb_unlock(&so->so_snd);
1821 			goto done;
1822 		}
1823 	}
1824 	if (mheader != NULL) {
1825 		*sbytes += mheader->m_pkthdr.len;
1826 
1827 		for (mp = mheader; mp != NULL; mp = mp->m_next)
1828 			ssb_preallocstream(&so->so_snd, mp);
1829 		if (use_sendfile_async)
1830 			error = so_pru_senda(so, 0, mheader, NULL, NULL, td);
1831 		else
1832 			error = so_pru_send(so, 0, mheader, NULL, NULL, td);
1833 
1834 		mheader = NULL;
1835 	}
1836 	ssb_unlock(&so->so_snd);
1837 
1838 done:
1839 	fdrop(fp);
1840 done0:
1841 	if (mheader != NULL)
1842 		m_freem(mheader);
1843 	return (error);
1844 }
1845 
1846 /*
1847  * MPALMOSTSAFE
1848  */
1849 int
1850 sys_sctp_peeloff(struct sctp_peeloff_args *uap)
1851 {
1852 #ifdef SCTP
1853 	struct thread *td = curthread;
1854 	struct filedesc *fdp = td->td_proc->p_fd;
1855 	struct file *lfp = NULL;
1856 	struct file *nfp = NULL;
1857 	int error;
1858 	struct socket *head, *so;
1859 	caddr_t assoc_id;
1860 	int fd;
1861 	short fflag;		/* type must match fp->f_flag */
1862 
1863 	assoc_id = uap->name;
1864 	error = holdsock(td->td_proc->p_fd, uap->sd, &lfp);
1865 	if (error)
1866 		return (error);
1867 
1868 	crit_enter();
1869 	head = (struct socket *)lfp->f_data;
1870 	error = sctp_can_peel_off(head, assoc_id);
1871 	if (error) {
1872 		crit_exit();
1873 		goto done;
1874 	}
1875 	/*
1876 	 * At this point we know we do have a assoc to pull
1877 	 * we proceed to get the fd setup. This may block
1878 	 * but that is ok.
1879 	 */
1880 
1881 	fflag = lfp->f_flag;
1882 	error = falloc(td->td_lwp, &nfp, &fd);
1883 	if (error) {
1884 		/*
1885 		 * Probably ran out of file descriptors. Put the
1886 		 * unaccepted connection back onto the queue and
1887 		 * do another wakeup so some other process might
1888 		 * have a chance at it.
1889 		 */
1890 		crit_exit();
1891 		goto done;
1892 	}
1893 	uap->sysmsg_iresult = fd;
1894 
1895 	so = sctp_get_peeloff(head, assoc_id, &error);
1896 	if (so == NULL) {
1897 		/*
1898 		 * Either someone else peeled it off OR
1899 		 * we can't get a socket.
1900 		 */
1901 		goto noconnection;
1902 	}
1903 	soreference(so);			/* reference needed */
1904 	soclrstate(so, SS_NOFDREF | SS_COMP);	/* when clearing NOFDREF */
1905 	so->so_head = NULL;
1906 	if (head->so_sigio != NULL)
1907 		fsetown(fgetown(&head->so_sigio), &so->so_sigio);
1908 
1909 	nfp->f_type = DTYPE_SOCKET;
1910 	nfp->f_flag = fflag;
1911 	nfp->f_ops = &socketops;
1912 	nfp->f_data = so;
1913 
1914 noconnection:
1915 	/*
1916 	 * Assign the file pointer to the reserved descriptor, or clear
1917 	 * the reserved descriptor if an error occured.
1918 	 */
1919 	if (error)
1920 		fsetfd(fdp, NULL, fd);
1921 	else
1922 		fsetfd(fdp, nfp, fd);
1923 	crit_exit();
1924 	/*
1925 	 * Release explicitly held references before returning.
1926 	 */
1927 done:
1928 	if (nfp != NULL)
1929 		fdrop(nfp);
1930 	fdrop(lfp);
1931 	return (error);
1932 #else /* SCTP */
1933 	return(EOPNOTSUPP);
1934 #endif /* SCTP */
1935 }
1936