xref: /freebsd/sys/kern/uipc_syscalls.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
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  * $FreeBSD$
38  */
39 
40 #include "opt_compat.h"
41 #include "opt_ktrace.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/mbuf.h>
54 #include <sys/protosw.h>
55 #include <sys/socket.h>
56 #include <sys/socketvar.h>
57 #include <sys/signalvar.h>
58 #include <sys/uio.h>
59 #include <sys/vnode.h>
60 #include <sys/lock.h>
61 #include <sys/mount.h>
62 #ifdef KTRACE
63 #include <sys/ktrace.h>
64 #endif
65 #include <vm/vm.h>
66 #include <vm/vm_object.h>
67 #include <vm/vm_page.h>
68 #include <vm/vm_pageout.h>
69 #include <vm/vm_kern.h>
70 #include <vm/vm_extern.h>
71 
72 static void sf_buf_init(void *arg);
73 SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL)
74 static struct sf_buf *sf_buf_alloc(void);
75 static void sf_buf_free(caddr_t addr, void *args);
76 
77 static int sendit __P((struct proc *p, int s, struct msghdr *mp, int flags));
78 static int recvit __P((struct proc *p, int s, struct msghdr *mp,
79 		       caddr_t namelenp));
80 
81 static int accept1 __P((struct proc *p, struct accept_args *uap, int compat));
82 static int getsockname1 __P((struct proc *p, struct getsockname_args *uap,
83 			     int compat));
84 static int getpeername1 __P((struct proc *p, struct getpeername_args *uap,
85 			     int compat));
86 
87 /*
88  * Expanded sf_freelist head. Really an SLIST_HEAD() in disguise, with the
89  * additional sf_lock mutex.
90  */
91 static struct {
92 	struct sf_buf *slh_first;
93 	struct mtx sf_lock;
94 } sf_freelist;
95 
96 static vm_offset_t sf_base;
97 static struct sf_buf *sf_bufs;
98 static u_int sf_buf_alloc_want;
99 
100 /*
101  * System call interface to the socket abstraction.
102  */
103 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
104 #define COMPAT_OLDSOCK
105 #endif
106 
107 extern	struct fileops socketops;
108 
109 int
110 socket(p, uap)
111 	struct proc *p;
112 	register struct socket_args /* {
113 		int	domain;
114 		int	type;
115 		int	protocol;
116 	} */ *uap;
117 {
118 	struct filedesc *fdp = p->p_fd;
119 	struct socket *so;
120 	struct file *fp;
121 	int fd, error;
122 
123 	error = falloc(p, &fp, &fd);
124 	if (error)
125 		return (error);
126 	fhold(fp);
127 	error = socreate(uap->domain, &so, uap->type, uap->protocol, p);
128 	if (error) {
129 		if (fdp->fd_ofiles[fd] == fp) {
130 			fdp->fd_ofiles[fd] = NULL;
131 			fdrop(fp, p);
132 		}
133 	} else {
134 		fp->f_data = (caddr_t)so;
135 		fp->f_flag = FREAD|FWRITE;
136 		fp->f_ops = &socketops;
137 		fp->f_type = DTYPE_SOCKET;
138 		p->p_retval[0] = fd;
139 	}
140 	fdrop(fp, p);
141 	return (error);
142 }
143 
144 /* ARGSUSED */
145 int
146 bind(p, uap)
147 	struct proc *p;
148 	register struct bind_args /* {
149 		int	s;
150 		caddr_t	name;
151 		int	namelen;
152 	} */ *uap;
153 {
154 	struct file *fp;
155 	struct sockaddr *sa;
156 	int error;
157 
158 	error = holdsock(p->p_fd, uap->s, &fp);
159 	if (error)
160 		return (error);
161 	error = getsockaddr(&sa, uap->name, uap->namelen);
162 	if (error) {
163 		fdrop(fp, p);
164 		return (error);
165 	}
166 	error = sobind((struct socket *)fp->f_data, sa, p);
167 	FREE(sa, M_SONAME);
168 	fdrop(fp, p);
169 	return (error);
170 }
171 
172 /* ARGSUSED */
173 int
174 listen(p, uap)
175 	struct proc *p;
176 	register struct listen_args /* {
177 		int	s;
178 		int	backlog;
179 	} */ *uap;
180 {
181 	struct file *fp;
182 	int error;
183 
184 	error = holdsock(p->p_fd, uap->s, &fp);
185 	if (error)
186 		return (error);
187 	error = solisten((struct socket *)fp->f_data, uap->backlog, p);
188 	fdrop(fp, p);
189 	return(error);
190 }
191 
192 static int
193 accept1(p, uap, compat)
194 	struct proc *p;
195 	register struct accept_args /* {
196 		int	s;
197 		caddr_t	name;
198 		int	*anamelen;
199 	} */ *uap;
200 	int compat;
201 {
202 	struct filedesc *fdp = p->p_fd;
203 	struct file *lfp = NULL;
204 	struct file *nfp = NULL;
205 	struct sockaddr *sa;
206 	int namelen, error, s;
207 	struct socket *head, *so;
208 	int fd;
209 	short fflag;		/* type must match fp->f_flag */
210 
211 	if (uap->name) {
212 		error = copyin((caddr_t)uap->anamelen, (caddr_t)&namelen,
213 			sizeof (namelen));
214 		if(error)
215 			return (error);
216 	}
217 	error = holdsock(fdp, uap->s, &lfp);
218 	if (error)
219 		return (error);
220 	s = splnet();
221 	head = (struct socket *)lfp->f_data;
222 	if ((head->so_options & SO_ACCEPTCONN) == 0) {
223 		splx(s);
224 		error = EINVAL;
225 		goto done;
226 	}
227 	if ((head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->so_comp)) {
228 		splx(s);
229 		error = EWOULDBLOCK;
230 		goto done;
231 	}
232 	while (TAILQ_EMPTY(&head->so_comp) && head->so_error == 0) {
233 		if (head->so_state & SS_CANTRCVMORE) {
234 			head->so_error = ECONNABORTED;
235 			break;
236 		}
237 		error = tsleep((caddr_t)&head->so_timeo, PSOCK | PCATCH,
238 		    "accept", 0);
239 		if (error) {
240 			splx(s);
241 			goto done;
242 		}
243 	}
244 	if (head->so_error) {
245 		error = head->so_error;
246 		head->so_error = 0;
247 		splx(s);
248 		goto done;
249 	}
250 
251 	/*
252 	 * At this point we know that there is at least one connection
253 	 * ready to be accepted. Remove it from the queue prior to
254 	 * allocating the file descriptor for it since falloc() may
255 	 * block allowing another process to accept the connection
256 	 * instead.
257 	 */
258 	so = TAILQ_FIRST(&head->so_comp);
259 	TAILQ_REMOVE(&head->so_comp, so, so_list);
260 	head->so_qlen--;
261 
262 	fflag = lfp->f_flag;
263 	error = falloc(p, &nfp, &fd);
264 	if (error) {
265 		/*
266 		 * Probably ran out of file descriptors. Put the
267 		 * unaccepted connection back onto the queue and
268 		 * do another wakeup so some other process might
269 		 * have a chance at it.
270 		 */
271 		TAILQ_INSERT_HEAD(&head->so_comp, so, so_list);
272 		head->so_qlen++;
273 		wakeup_one(&head->so_timeo);
274 		splx(s);
275 		goto done;
276 	}
277 	fhold(nfp);
278 	p->p_retval[0] = fd;
279 
280 	/* connection has been removed from the listen queue */
281 	KNOTE(&head->so_rcv.sb_sel.si_note, 0);
282 
283 	so->so_state &= ~SS_COMP;
284 	so->so_head = NULL;
285 	if (head->so_sigio != NULL)
286 		fsetown(fgetown(head->so_sigio), &so->so_sigio);
287 
288 	nfp->f_data = (caddr_t)so;
289 	nfp->f_flag = fflag;
290 	nfp->f_ops = &socketops;
291 	nfp->f_type = DTYPE_SOCKET;
292 	sa = 0;
293 	(void) soaccept(so, &sa);
294 	if (sa == NULL) {
295 		namelen = 0;
296 		if (uap->name)
297 			goto gotnoname;
298 		splx(s);
299 		error = 0;
300 		goto done;
301 	}
302 	if (uap->name) {
303 		/* check sa_len before it is destroyed */
304 		if (namelen > sa->sa_len)
305 			namelen = sa->sa_len;
306 #ifdef COMPAT_OLDSOCK
307 		if (compat)
308 			((struct osockaddr *)sa)->sa_family =
309 			    sa->sa_family;
310 #endif
311 		error = copyout(sa, (caddr_t)uap->name, (u_int)namelen);
312 		if (!error)
313 gotnoname:
314 			error = copyout((caddr_t)&namelen,
315 			    (caddr_t)uap->anamelen, sizeof (*uap->anamelen));
316 	}
317 	if (sa)
318 		FREE(sa, M_SONAME);
319 
320 	/*
321 	 * close the new descriptor, assuming someone hasn't ripped it
322 	 * out from under us.
323 	 */
324 	if (error) {
325 		if (fdp->fd_ofiles[fd] == nfp) {
326 			fdp->fd_ofiles[fd] = NULL;
327 			fdrop(nfp, p);
328 		}
329 	}
330 	splx(s);
331 
332 	/*
333 	 * Release explicitly held references before returning.
334 	 */
335 done:
336 	if (nfp != NULL)
337 		fdrop(nfp, p);
338 	fdrop(lfp, p);
339 	return (error);
340 }
341 
342 int
343 accept(p, uap)
344 	struct proc *p;
345 	struct accept_args *uap;
346 {
347 
348 	return (accept1(p, uap, 0));
349 }
350 
351 #ifdef COMPAT_OLDSOCK
352 int
353 oaccept(p, uap)
354 	struct proc *p;
355 	struct accept_args *uap;
356 {
357 
358 	return (accept1(p, uap, 1));
359 }
360 #endif /* COMPAT_OLDSOCK */
361 
362 /* ARGSUSED */
363 int
364 connect(p, uap)
365 	struct proc *p;
366 	register struct connect_args /* {
367 		int	s;
368 		caddr_t	name;
369 		int	namelen;
370 	} */ *uap;
371 {
372 	struct file *fp;
373 	register struct socket *so;
374 	struct sockaddr *sa;
375 	int error, s;
376 
377 	error = holdsock(p->p_fd, uap->s, &fp);
378 	if (error)
379 		return (error);
380 	so = (struct socket *)fp->f_data;
381 	if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
382 		error = EALREADY;
383 		goto done;
384 	}
385 	error = getsockaddr(&sa, uap->name, uap->namelen);
386 	if (error)
387 		goto done;
388 	error = soconnect(so, sa, p);
389 	if (error)
390 		goto bad;
391 	if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
392 		FREE(sa, M_SONAME);
393 		error = EINPROGRESS;
394 		goto done;
395 	}
396 	s = splnet();
397 	while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
398 		error = tsleep((caddr_t)&so->so_timeo, PSOCK | PCATCH,
399 		    "connec", 0);
400 		if (error)
401 			break;
402 	}
403 	if (error == 0) {
404 		error = so->so_error;
405 		so->so_error = 0;
406 	}
407 	splx(s);
408 bad:
409 	so->so_state &= ~SS_ISCONNECTING;
410 	FREE(sa, M_SONAME);
411 	if (error == ERESTART)
412 		error = EINTR;
413 done:
414 	fdrop(fp, p);
415 	return (error);
416 }
417 
418 int
419 socketpair(p, uap)
420 	struct proc *p;
421 	register struct socketpair_args /* {
422 		int	domain;
423 		int	type;
424 		int	protocol;
425 		int	*rsv;
426 	} */ *uap;
427 {
428 	register struct filedesc *fdp = p->p_fd;
429 	struct file *fp1, *fp2;
430 	struct socket *so1, *so2;
431 	int fd, error, sv[2];
432 
433 	error = socreate(uap->domain, &so1, uap->type, uap->protocol, p);
434 	if (error)
435 		return (error);
436 	error = socreate(uap->domain, &so2, uap->type, uap->protocol, p);
437 	if (error)
438 		goto free1;
439 	error = falloc(p, &fp1, &fd);
440 	if (error)
441 		goto free2;
442 	fhold(fp1);
443 	sv[0] = fd;
444 	fp1->f_data = (caddr_t)so1;
445 	error = falloc(p, &fp2, &fd);
446 	if (error)
447 		goto free3;
448 	fhold(fp2);
449 	fp2->f_data = (caddr_t)so2;
450 	sv[1] = fd;
451 	error = soconnect2(so1, so2);
452 	if (error)
453 		goto free4;
454 	if (uap->type == SOCK_DGRAM) {
455 		/*
456 		 * Datagram socket connection is asymmetric.
457 		 */
458 		 error = soconnect2(so2, so1);
459 		 if (error)
460 			goto free4;
461 	}
462 	fp1->f_flag = fp2->f_flag = FREAD|FWRITE;
463 	fp1->f_ops = fp2->f_ops = &socketops;
464 	fp1->f_type = fp2->f_type = DTYPE_SOCKET;
465 	error = copyout((caddr_t)sv, (caddr_t)uap->rsv, 2 * sizeof (int));
466 	fdrop(fp1, p);
467 	fdrop(fp2, p);
468 	return (error);
469 free4:
470 	if (fdp->fd_ofiles[sv[1]] == fp2) {
471 		fdp->fd_ofiles[sv[1]] = NULL;
472 		fdrop(fp2, p);
473 	}
474 	fdrop(fp2, p);
475 free3:
476 	if (fdp->fd_ofiles[sv[0]] == fp1) {
477 		fdp->fd_ofiles[sv[0]] = NULL;
478 		fdrop(fp1, p);
479 	}
480 	fdrop(fp1, p);
481 free2:
482 	(void)soclose(so2);
483 free1:
484 	(void)soclose(so1);
485 	return (error);
486 }
487 
488 static int
489 sendit(p, s, mp, flags)
490 	register struct proc *p;
491 	int s;
492 	register struct msghdr *mp;
493 	int flags;
494 {
495 	struct file *fp;
496 	struct uio auio;
497 	register struct iovec *iov;
498 	register int i;
499 	struct mbuf *control;
500 	struct sockaddr *to;
501 	int len, error;
502 	struct socket *so;
503 #ifdef KTRACE
504 	struct iovec *ktriov = NULL;
505 	struct uio ktruio;
506 #endif
507 
508 	error = holdsock(p->p_fd, s, &fp);
509 	if (error)
510 		return (error);
511 	auio.uio_iov = mp->msg_iov;
512 	auio.uio_iovcnt = mp->msg_iovlen;
513 	auio.uio_segflg = UIO_USERSPACE;
514 	auio.uio_rw = UIO_WRITE;
515 	auio.uio_procp = p;
516 	auio.uio_offset = 0;			/* XXX */
517 	auio.uio_resid = 0;
518 	iov = mp->msg_iov;
519 	for (i = 0; i < mp->msg_iovlen; i++, iov++) {
520 		if ((auio.uio_resid += iov->iov_len) < 0) {
521 			fdrop(fp, p);
522 			return (EINVAL);
523 		}
524 	}
525 	if (mp->msg_name) {
526 		error = getsockaddr(&to, mp->msg_name, mp->msg_namelen);
527 		if (error) {
528 			fdrop(fp, p);
529 			return (error);
530 		}
531 	} else {
532 		to = 0;
533 	}
534 	if (mp->msg_control) {
535 		if (mp->msg_controllen < sizeof(struct cmsghdr)
536 #ifdef COMPAT_OLDSOCK
537 		    && mp->msg_flags != MSG_COMPAT
538 #endif
539 		) {
540 			error = EINVAL;
541 			goto bad;
542 		}
543 		error = sockargs(&control, mp->msg_control,
544 		    mp->msg_controllen, MT_CONTROL);
545 		if (error)
546 			goto bad;
547 #ifdef COMPAT_OLDSOCK
548 		if (mp->msg_flags == MSG_COMPAT) {
549 			register struct cmsghdr *cm;
550 
551 			M_PREPEND(control, sizeof(*cm), M_WAIT);
552 			if (control == 0) {
553 				error = ENOBUFS;
554 				goto bad;
555 			} else {
556 				cm = mtod(control, struct cmsghdr *);
557 				cm->cmsg_len = control->m_len;
558 				cm->cmsg_level = SOL_SOCKET;
559 				cm->cmsg_type = SCM_RIGHTS;
560 			}
561 		}
562 #endif
563 	} else {
564 		control = 0;
565 	}
566 #ifdef KTRACE
567 	if (KTRPOINT(p, KTR_GENIO)) {
568 		int iovlen = auio.uio_iovcnt * sizeof (struct iovec);
569 
570 		MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
571 		bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen);
572 		ktruio = auio;
573 	}
574 #endif
575 	len = auio.uio_resid;
576 	so = (struct socket *)fp->f_data;
577 	error = so->so_proto->pr_usrreqs->pru_sosend(so, to, &auio, 0, control,
578 						     flags, p);
579 	if (error) {
580 		if (auio.uio_resid != len && (error == ERESTART ||
581 		    error == EINTR || error == EWOULDBLOCK))
582 			error = 0;
583 		if (error == EPIPE)
584 			psignal(p, SIGPIPE);
585 	}
586 	if (error == 0)
587 		p->p_retval[0] = len - auio.uio_resid;
588 #ifdef KTRACE
589 	if (ktriov != NULL) {
590 		if (error == 0) {
591 			ktruio.uio_iov = ktriov;
592 			ktruio.uio_resid = p->p_retval[0];
593 			ktrgenio(p->p_tracep, s, UIO_WRITE, &ktruio, error);
594 		}
595 		FREE(ktriov, M_TEMP);
596 	}
597 #endif
598 bad:
599 	fdrop(fp, p);
600 	if (to)
601 		FREE(to, M_SONAME);
602 	return (error);
603 }
604 
605 int
606 sendto(p, uap)
607 	struct proc *p;
608 	register struct sendto_args /* {
609 		int	s;
610 		caddr_t	buf;
611 		size_t	len;
612 		int	flags;
613 		caddr_t	to;
614 		int	tolen;
615 	} */ *uap;
616 {
617 	struct msghdr msg;
618 	struct iovec aiov;
619 
620 	msg.msg_name = uap->to;
621 	msg.msg_namelen = uap->tolen;
622 	msg.msg_iov = &aiov;
623 	msg.msg_iovlen = 1;
624 	msg.msg_control = 0;
625 #ifdef COMPAT_OLDSOCK
626 	msg.msg_flags = 0;
627 #endif
628 	aiov.iov_base = uap->buf;
629 	aiov.iov_len = uap->len;
630 	return (sendit(p, uap->s, &msg, uap->flags));
631 }
632 
633 #ifdef COMPAT_OLDSOCK
634 int
635 osend(p, uap)
636 	struct proc *p;
637 	register struct osend_args /* {
638 		int	s;
639 		caddr_t	buf;
640 		int	len;
641 		int	flags;
642 	} */ *uap;
643 {
644 	struct msghdr msg;
645 	struct iovec aiov;
646 
647 	msg.msg_name = 0;
648 	msg.msg_namelen = 0;
649 	msg.msg_iov = &aiov;
650 	msg.msg_iovlen = 1;
651 	aiov.iov_base = uap->buf;
652 	aiov.iov_len = uap->len;
653 	msg.msg_control = 0;
654 	msg.msg_flags = 0;
655 	return (sendit(p, uap->s, &msg, uap->flags));
656 }
657 
658 int
659 osendmsg(p, uap)
660 	struct proc *p;
661 	register struct osendmsg_args /* {
662 		int	s;
663 		caddr_t	msg;
664 		int	flags;
665 	} */ *uap;
666 {
667 	struct msghdr msg;
668 	struct iovec aiov[UIO_SMALLIOV], *iov;
669 	int error;
670 
671 	error = copyin(uap->msg, (caddr_t)&msg, sizeof (struct omsghdr));
672 	if (error)
673 		return (error);
674 	if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
675 		if ((u_int)msg.msg_iovlen >= UIO_MAXIOV)
676 			return (EMSGSIZE);
677 		MALLOC(iov, struct iovec *,
678 		      sizeof(struct iovec) * (u_int)msg.msg_iovlen, M_IOV,
679 		      M_WAITOK);
680 	} else
681 		iov = aiov;
682 	error = copyin((caddr_t)msg.msg_iov, (caddr_t)iov,
683 	    (unsigned)(msg.msg_iovlen * sizeof (struct iovec)));
684 	if (error)
685 		goto done;
686 	msg.msg_flags = MSG_COMPAT;
687 	msg.msg_iov = iov;
688 	error = sendit(p, uap->s, &msg, uap->flags);
689 done:
690 	if (iov != aiov)
691 		FREE(iov, M_IOV);
692 	return (error);
693 }
694 #endif
695 
696 int
697 sendmsg(p, uap)
698 	struct proc *p;
699 	register struct sendmsg_args /* {
700 		int	s;
701 		caddr_t	msg;
702 		int	flags;
703 	} */ *uap;
704 {
705 	struct msghdr msg;
706 	struct iovec aiov[UIO_SMALLIOV], *iov;
707 	int error;
708 
709 	error = copyin(uap->msg, (caddr_t)&msg, sizeof (msg));
710 	if (error)
711 		return (error);
712 	if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
713 		if ((u_int)msg.msg_iovlen >= UIO_MAXIOV)
714 			return (EMSGSIZE);
715 		MALLOC(iov, struct iovec *,
716 		       sizeof(struct iovec) * (u_int)msg.msg_iovlen, M_IOV,
717 		       M_WAITOK);
718 	} else
719 		iov = aiov;
720 	if (msg.msg_iovlen &&
721 	    (error = copyin((caddr_t)msg.msg_iov, (caddr_t)iov,
722 	    (unsigned)(msg.msg_iovlen * sizeof (struct iovec)))))
723 		goto done;
724 	msg.msg_iov = iov;
725 #ifdef COMPAT_OLDSOCK
726 	msg.msg_flags = 0;
727 #endif
728 	error = sendit(p, uap->s, &msg, uap->flags);
729 done:
730 	if (iov != aiov)
731 		FREE(iov, M_IOV);
732 	return (error);
733 }
734 
735 static int
736 recvit(p, s, mp, namelenp)
737 	register struct proc *p;
738 	int s;
739 	register struct msghdr *mp;
740 	caddr_t namelenp;
741 {
742 	struct file *fp;
743 	struct uio auio;
744 	register struct iovec *iov;
745 	register int i;
746 	int len, error;
747 	struct mbuf *m, *control = 0;
748 	caddr_t ctlbuf;
749 	struct socket *so;
750 	struct sockaddr *fromsa = 0;
751 #ifdef KTRACE
752 	struct iovec *ktriov = NULL;
753 	struct uio ktruio;
754 #endif
755 
756 	error = holdsock(p->p_fd, s, &fp);
757 	if (error)
758 		return (error);
759 	auio.uio_iov = mp->msg_iov;
760 	auio.uio_iovcnt = mp->msg_iovlen;
761 	auio.uio_segflg = UIO_USERSPACE;
762 	auio.uio_rw = UIO_READ;
763 	auio.uio_procp = p;
764 	auio.uio_offset = 0;			/* XXX */
765 	auio.uio_resid = 0;
766 	iov = mp->msg_iov;
767 	for (i = 0; i < mp->msg_iovlen; i++, iov++) {
768 		if ((auio.uio_resid += iov->iov_len) < 0) {
769 			fdrop(fp, p);
770 			return (EINVAL);
771 		}
772 	}
773 #ifdef KTRACE
774 	if (KTRPOINT(p, KTR_GENIO)) {
775 		int iovlen = auio.uio_iovcnt * sizeof (struct iovec);
776 
777 		MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
778 		bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen);
779 		ktruio = auio;
780 	}
781 #endif
782 	len = auio.uio_resid;
783 	so = (struct socket *)fp->f_data;
784 	error = so->so_proto->pr_usrreqs->pru_soreceive(so, &fromsa, &auio,
785 	    (struct mbuf **)0, mp->msg_control ? &control : (struct mbuf **)0,
786 	    &mp->msg_flags);
787 	if (error) {
788 		if (auio.uio_resid != len && (error == ERESTART ||
789 		    error == EINTR || error == EWOULDBLOCK))
790 			error = 0;
791 	}
792 #ifdef KTRACE
793 	if (ktriov != NULL) {
794 		if (error == 0) {
795 			ktruio.uio_iov = ktriov;
796 			ktruio.uio_resid = len - auio.uio_resid;
797 			ktrgenio(p->p_tracep, s, UIO_READ, &ktruio, error);
798 		}
799 		FREE(ktriov, M_TEMP);
800 	}
801 #endif
802 	if (error)
803 		goto out;
804 	p->p_retval[0] = len - auio.uio_resid;
805 	if (mp->msg_name) {
806 		len = mp->msg_namelen;
807 		if (len <= 0 || fromsa == 0)
808 			len = 0;
809 		else {
810 #ifndef MIN
811 #define MIN(a,b) ((a)>(b)?(b):(a))
812 #endif
813 			/* save sa_len before it is destroyed by MSG_COMPAT */
814 			len = MIN(len, fromsa->sa_len);
815 #ifdef COMPAT_OLDSOCK
816 			if (mp->msg_flags & MSG_COMPAT)
817 				((struct osockaddr *)fromsa)->sa_family =
818 				    fromsa->sa_family;
819 #endif
820 			error = copyout(fromsa,
821 			    (caddr_t)mp->msg_name, (unsigned)len);
822 			if (error)
823 				goto out;
824 		}
825 		mp->msg_namelen = len;
826 		if (namelenp &&
827 		    (error = copyout((caddr_t)&len, namelenp, sizeof (int)))) {
828 #ifdef COMPAT_OLDSOCK
829 			if (mp->msg_flags & MSG_COMPAT)
830 				error = 0;	/* old recvfrom didn't check */
831 			else
832 #endif
833 			goto out;
834 		}
835 	}
836 	if (mp->msg_control) {
837 #ifdef COMPAT_OLDSOCK
838 		/*
839 		 * We assume that old recvmsg calls won't receive access
840 		 * rights and other control info, esp. as control info
841 		 * is always optional and those options didn't exist in 4.3.
842 		 * If we receive rights, trim the cmsghdr; anything else
843 		 * is tossed.
844 		 */
845 		if (control && mp->msg_flags & MSG_COMPAT) {
846 			if (mtod(control, struct cmsghdr *)->cmsg_level !=
847 			    SOL_SOCKET ||
848 			    mtod(control, struct cmsghdr *)->cmsg_type !=
849 			    SCM_RIGHTS) {
850 				mp->msg_controllen = 0;
851 				goto out;
852 			}
853 			control->m_len -= sizeof (struct cmsghdr);
854 			control->m_data += sizeof (struct cmsghdr);
855 		}
856 #endif
857 		len = mp->msg_controllen;
858 		m = control;
859 		mp->msg_controllen = 0;
860 		ctlbuf = (caddr_t) mp->msg_control;
861 
862 		while (m && len > 0) {
863 			unsigned int tocopy;
864 
865 			if (len >= m->m_len)
866 				tocopy = m->m_len;
867 			else {
868 				mp->msg_flags |= MSG_CTRUNC;
869 				tocopy = len;
870 			}
871 
872 			if ((error = copyout((caddr_t)mtod(m, caddr_t),
873 					ctlbuf, tocopy)) != 0)
874 				goto out;
875 
876 			ctlbuf += tocopy;
877 			len -= tocopy;
878 			m = m->m_next;
879 		}
880 		mp->msg_controllen = ctlbuf - (caddr_t)mp->msg_control;
881 	}
882 out:
883 	fdrop(fp, p);
884 	if (fromsa)
885 		FREE(fromsa, M_SONAME);
886 	if (control)
887 		m_freem(control);
888 	return (error);
889 }
890 
891 int
892 recvfrom(p, uap)
893 	struct proc *p;
894 	register struct recvfrom_args /* {
895 		int	s;
896 		caddr_t	buf;
897 		size_t	len;
898 		int	flags;
899 		caddr_t	from;
900 		int	*fromlenaddr;
901 	} */ *uap;
902 {
903 	struct msghdr msg;
904 	struct iovec aiov;
905 	int error;
906 
907 	if (uap->fromlenaddr) {
908 		error = copyin((caddr_t)uap->fromlenaddr,
909 		    (caddr_t)&msg.msg_namelen, sizeof (msg.msg_namelen));
910 		if (error)
911 			return (error);
912 	} else
913 		msg.msg_namelen = 0;
914 	msg.msg_name = uap->from;
915 	msg.msg_iov = &aiov;
916 	msg.msg_iovlen = 1;
917 	aiov.iov_base = uap->buf;
918 	aiov.iov_len = uap->len;
919 	msg.msg_control = 0;
920 	msg.msg_flags = uap->flags;
921 	return (recvit(p, uap->s, &msg, (caddr_t)uap->fromlenaddr));
922 }
923 
924 #ifdef COMPAT_OLDSOCK
925 int
926 orecvfrom(p, uap)
927 	struct proc *p;
928 	struct recvfrom_args *uap;
929 {
930 
931 	uap->flags |= MSG_COMPAT;
932 	return (recvfrom(p, uap));
933 }
934 #endif
935 
936 
937 #ifdef COMPAT_OLDSOCK
938 int
939 orecv(p, uap)
940 	struct proc *p;
941 	register struct orecv_args /* {
942 		int	s;
943 		caddr_t	buf;
944 		int	len;
945 		int	flags;
946 	} */ *uap;
947 {
948 	struct msghdr msg;
949 	struct iovec aiov;
950 
951 	msg.msg_name = 0;
952 	msg.msg_namelen = 0;
953 	msg.msg_iov = &aiov;
954 	msg.msg_iovlen = 1;
955 	aiov.iov_base = uap->buf;
956 	aiov.iov_len = uap->len;
957 	msg.msg_control = 0;
958 	msg.msg_flags = uap->flags;
959 	return (recvit(p, uap->s, &msg, (caddr_t)0));
960 }
961 
962 /*
963  * Old recvmsg.  This code takes advantage of the fact that the old msghdr
964  * overlays the new one, missing only the flags, and with the (old) access
965  * rights where the control fields are now.
966  */
967 int
968 orecvmsg(p, uap)
969 	struct proc *p;
970 	register struct orecvmsg_args /* {
971 		int	s;
972 		struct	omsghdr *msg;
973 		int	flags;
974 	} */ *uap;
975 {
976 	struct msghdr msg;
977 	struct iovec aiov[UIO_SMALLIOV], *iov;
978 	int error;
979 
980 	error = copyin((caddr_t)uap->msg, (caddr_t)&msg,
981 	    sizeof (struct omsghdr));
982 	if (error)
983 		return (error);
984 	if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
985 		if ((u_int)msg.msg_iovlen >= UIO_MAXIOV)
986 			return (EMSGSIZE);
987 		MALLOC(iov, struct iovec *,
988 		      sizeof(struct iovec) * (u_int)msg.msg_iovlen, M_IOV,
989 		      M_WAITOK);
990 	} else
991 		iov = aiov;
992 	msg.msg_flags = uap->flags | MSG_COMPAT;
993 	error = copyin((caddr_t)msg.msg_iov, (caddr_t)iov,
994 	    (unsigned)(msg.msg_iovlen * sizeof (struct iovec)));
995 	if (error)
996 		goto done;
997 	msg.msg_iov = iov;
998 	error = recvit(p, uap->s, &msg, (caddr_t)&uap->msg->msg_namelen);
999 
1000 	if (msg.msg_controllen && error == 0)
1001 		error = copyout((caddr_t)&msg.msg_controllen,
1002 		    (caddr_t)&uap->msg->msg_accrightslen, sizeof (int));
1003 done:
1004 	if (iov != aiov)
1005 		FREE(iov, M_IOV);
1006 	return (error);
1007 }
1008 #endif
1009 
1010 int
1011 recvmsg(p, uap)
1012 	struct proc *p;
1013 	register struct recvmsg_args /* {
1014 		int	s;
1015 		struct	msghdr *msg;
1016 		int	flags;
1017 	} */ *uap;
1018 {
1019 	struct msghdr msg;
1020 	struct iovec aiov[UIO_SMALLIOV], *uiov, *iov;
1021 	register int error;
1022 
1023 	error = copyin((caddr_t)uap->msg, (caddr_t)&msg, sizeof (msg));
1024 	if (error)
1025 		return (error);
1026 	if ((u_int)msg.msg_iovlen >= UIO_SMALLIOV) {
1027 		if ((u_int)msg.msg_iovlen >= UIO_MAXIOV)
1028 			return (EMSGSIZE);
1029 		MALLOC(iov, struct iovec *,
1030 		       sizeof(struct iovec) * (u_int)msg.msg_iovlen, M_IOV,
1031 		       M_WAITOK);
1032 	} else
1033 		iov = aiov;
1034 #ifdef COMPAT_OLDSOCK
1035 	msg.msg_flags = uap->flags &~ MSG_COMPAT;
1036 #else
1037 	msg.msg_flags = uap->flags;
1038 #endif
1039 	uiov = msg.msg_iov;
1040 	msg.msg_iov = iov;
1041 	error = copyin((caddr_t)uiov, (caddr_t)iov,
1042 	    (unsigned)(msg.msg_iovlen * sizeof (struct iovec)));
1043 	if (error)
1044 		goto done;
1045 	error = recvit(p, uap->s, &msg, (caddr_t)0);
1046 	if (!error) {
1047 		msg.msg_iov = uiov;
1048 		error = copyout((caddr_t)&msg, (caddr_t)uap->msg, sizeof(msg));
1049 	}
1050 done:
1051 	if (iov != aiov)
1052 		FREE(iov, M_IOV);
1053 	return (error);
1054 }
1055 
1056 /* ARGSUSED */
1057 int
1058 shutdown(p, uap)
1059 	struct proc *p;
1060 	register struct shutdown_args /* {
1061 		int	s;
1062 		int	how;
1063 	} */ *uap;
1064 {
1065 	struct file *fp;
1066 	int error;
1067 
1068 	error = holdsock(p->p_fd, uap->s, &fp);
1069 	if (error)
1070 		return (error);
1071 	error = soshutdown((struct socket *)fp->f_data, uap->how);
1072 	fdrop(fp, p);
1073 	return(error);
1074 }
1075 
1076 /* ARGSUSED */
1077 int
1078 setsockopt(p, uap)
1079 	struct proc *p;
1080 	register struct setsockopt_args /* {
1081 		int	s;
1082 		int	level;
1083 		int	name;
1084 		caddr_t	val;
1085 		int	valsize;
1086 	} */ *uap;
1087 {
1088 	struct file *fp;
1089 	struct sockopt sopt;
1090 	int error;
1091 
1092 	if (uap->val == 0 && uap->valsize != 0)
1093 		return (EFAULT);
1094 	if (uap->valsize < 0)
1095 		return (EINVAL);
1096 
1097 	error = holdsock(p->p_fd, uap->s, &fp);
1098 	if (error)
1099 		return (error);
1100 
1101 	sopt.sopt_dir = SOPT_SET;
1102 	sopt.sopt_level = uap->level;
1103 	sopt.sopt_name = uap->name;
1104 	sopt.sopt_val = uap->val;
1105 	sopt.sopt_valsize = uap->valsize;
1106 	sopt.sopt_p = p;
1107 	error = sosetopt((struct socket *)fp->f_data, &sopt);
1108 	fdrop(fp, p);
1109 	return(error);
1110 }
1111 
1112 /* ARGSUSED */
1113 int
1114 getsockopt(p, uap)
1115 	struct proc *p;
1116 	register struct getsockopt_args /* {
1117 		int	s;
1118 		int	level;
1119 		int	name;
1120 		caddr_t	val;
1121 		int	*avalsize;
1122 	} */ *uap;
1123 {
1124 	int	valsize, error;
1125 	struct	file *fp;
1126 	struct	sockopt sopt;
1127 
1128 	error = holdsock(p->p_fd, uap->s, &fp);
1129 	if (error)
1130 		return (error);
1131 	if (uap->val) {
1132 		error = copyin((caddr_t)uap->avalsize, (caddr_t)&valsize,
1133 		    sizeof (valsize));
1134 		if (error) {
1135 			fdrop(fp, p);
1136 			return (error);
1137 		}
1138 		if (valsize < 0) {
1139 			fdrop(fp, p);
1140 			return (EINVAL);
1141 		}
1142 	} else {
1143 		valsize = 0;
1144 	}
1145 
1146 	sopt.sopt_dir = SOPT_GET;
1147 	sopt.sopt_level = uap->level;
1148 	sopt.sopt_name = uap->name;
1149 	sopt.sopt_val = uap->val;
1150 	sopt.sopt_valsize = (size_t)valsize; /* checked non-negative above */
1151 	sopt.sopt_p = p;
1152 
1153 	error = sogetopt((struct socket *)fp->f_data, &sopt);
1154 	if (error == 0) {
1155 		valsize = sopt.sopt_valsize;
1156 		error = copyout((caddr_t)&valsize,
1157 				(caddr_t)uap->avalsize, sizeof (valsize));
1158 	}
1159 	fdrop(fp, p);
1160 	return (error);
1161 }
1162 
1163 /*
1164  * Get socket name.
1165  */
1166 /* ARGSUSED */
1167 static int
1168 getsockname1(p, uap, compat)
1169 	struct proc *p;
1170 	register struct getsockname_args /* {
1171 		int	fdes;
1172 		caddr_t	asa;
1173 		int	*alen;
1174 	} */ *uap;
1175 	int compat;
1176 {
1177 	struct file *fp;
1178 	register struct socket *so;
1179 	struct sockaddr *sa;
1180 	int len, error;
1181 
1182 	error = holdsock(p->p_fd, uap->fdes, &fp);
1183 	if (error)
1184 		return (error);
1185 	error = copyin((caddr_t)uap->alen, (caddr_t)&len, sizeof (len));
1186 	if (error) {
1187 		fdrop(fp, p);
1188 		return (error);
1189 	}
1190 	so = (struct socket *)fp->f_data;
1191 	sa = 0;
1192 	error = (*so->so_proto->pr_usrreqs->pru_sockaddr)(so, &sa);
1193 	if (error)
1194 		goto bad;
1195 	if (sa == 0) {
1196 		len = 0;
1197 		goto gotnothing;
1198 	}
1199 
1200 	len = MIN(len, sa->sa_len);
1201 #ifdef COMPAT_OLDSOCK
1202 	if (compat)
1203 		((struct osockaddr *)sa)->sa_family = sa->sa_family;
1204 #endif
1205 	error = copyout(sa, (caddr_t)uap->asa, (u_int)len);
1206 	if (error == 0)
1207 gotnothing:
1208 		error = copyout((caddr_t)&len, (caddr_t)uap->alen,
1209 		    sizeof (len));
1210 bad:
1211 	if (sa)
1212 		FREE(sa, M_SONAME);
1213 	fdrop(fp, p);
1214 	return (error);
1215 }
1216 
1217 int
1218 getsockname(p, uap)
1219 	struct proc *p;
1220 	struct getsockname_args *uap;
1221 {
1222 
1223 	return (getsockname1(p, uap, 0));
1224 }
1225 
1226 #ifdef COMPAT_OLDSOCK
1227 int
1228 ogetsockname(p, uap)
1229 	struct proc *p;
1230 	struct getsockname_args *uap;
1231 {
1232 
1233 	return (getsockname1(p, uap, 1));
1234 }
1235 #endif /* COMPAT_OLDSOCK */
1236 
1237 /*
1238  * Get name of peer for connected socket.
1239  */
1240 /* ARGSUSED */
1241 static int
1242 getpeername1(p, uap, compat)
1243 	struct proc *p;
1244 	register struct getpeername_args /* {
1245 		int	fdes;
1246 		caddr_t	asa;
1247 		int	*alen;
1248 	} */ *uap;
1249 	int compat;
1250 {
1251 	struct file *fp;
1252 	register struct socket *so;
1253 	struct sockaddr *sa;
1254 	int len, error;
1255 
1256 	error = holdsock(p->p_fd, uap->fdes, &fp);
1257 	if (error)
1258 		return (error);
1259 	so = (struct socket *)fp->f_data;
1260 	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
1261 		fdrop(fp, p);
1262 		return (ENOTCONN);
1263 	}
1264 	error = copyin((caddr_t)uap->alen, (caddr_t)&len, sizeof (len));
1265 	if (error) {
1266 		fdrop(fp, p);
1267 		return (error);
1268 	}
1269 	sa = 0;
1270 	error = (*so->so_proto->pr_usrreqs->pru_peeraddr)(so, &sa);
1271 	if (error)
1272 		goto bad;
1273 	if (sa == 0) {
1274 		len = 0;
1275 		goto gotnothing;
1276 	}
1277 	len = MIN(len, sa->sa_len);
1278 #ifdef COMPAT_OLDSOCK
1279 	if (compat)
1280 		((struct osockaddr *)sa)->sa_family =
1281 		    sa->sa_family;
1282 #endif
1283 	error = copyout(sa, (caddr_t)uap->asa, (u_int)len);
1284 	if (error)
1285 		goto bad;
1286 gotnothing:
1287 	error = copyout((caddr_t)&len, (caddr_t)uap->alen, sizeof (len));
1288 bad:
1289 	if (sa)
1290 		FREE(sa, M_SONAME);
1291 	fdrop(fp, p);
1292 	return (error);
1293 }
1294 
1295 int
1296 getpeername(p, uap)
1297 	struct proc *p;
1298 	struct getpeername_args *uap;
1299 {
1300 
1301 	return (getpeername1(p, uap, 0));
1302 }
1303 
1304 #ifdef COMPAT_OLDSOCK
1305 int
1306 ogetpeername(p, uap)
1307 	struct proc *p;
1308 	struct ogetpeername_args *uap;
1309 {
1310 
1311 	/* XXX uap should have type `getpeername_args *' to begin with. */
1312 	return (getpeername1(p, (struct getpeername_args *)uap, 1));
1313 }
1314 #endif /* COMPAT_OLDSOCK */
1315 
1316 int
1317 sockargs(mp, buf, buflen, type)
1318 	struct mbuf **mp;
1319 	caddr_t buf;
1320 	int buflen, type;
1321 {
1322 	register struct sockaddr *sa;
1323 	register struct mbuf *m;
1324 	int error;
1325 
1326 	if ((u_int)buflen > MLEN) {
1327 #ifdef COMPAT_OLDSOCK
1328 		if (type == MT_SONAME && (u_int)buflen <= 112)
1329 			buflen = MLEN;		/* unix domain compat. hack */
1330 		else
1331 #endif
1332 		return (EINVAL);
1333 	}
1334 	m = m_get(M_WAIT, type);
1335 	if (m == NULL)
1336 		return (ENOBUFS);
1337 	m->m_len = buflen;
1338 	error = copyin(buf, mtod(m, caddr_t), (u_int)buflen);
1339 	if (error)
1340 		(void) m_free(m);
1341 	else {
1342 		*mp = m;
1343 		if (type == MT_SONAME) {
1344 			sa = mtod(m, struct sockaddr *);
1345 
1346 #if defined(COMPAT_OLDSOCK) && BYTE_ORDER != BIG_ENDIAN
1347 			if (sa->sa_family == 0 && sa->sa_len < AF_MAX)
1348 				sa->sa_family = sa->sa_len;
1349 #endif
1350 			sa->sa_len = buflen;
1351 		}
1352 	}
1353 	return (error);
1354 }
1355 
1356 int
1357 getsockaddr(namp, uaddr, len)
1358 	struct sockaddr **namp;
1359 	caddr_t uaddr;
1360 	size_t len;
1361 {
1362 	struct sockaddr *sa;
1363 	int error;
1364 
1365 	if (len > SOCK_MAXADDRLEN)
1366 		return ENAMETOOLONG;
1367 	MALLOC(sa, struct sockaddr *, len, M_SONAME, M_WAITOK);
1368 	error = copyin(uaddr, sa, len);
1369 	if (error) {
1370 		FREE(sa, M_SONAME);
1371 	} else {
1372 #if defined(COMPAT_OLDSOCK) && BYTE_ORDER != BIG_ENDIAN
1373 		if (sa->sa_family == 0 && sa->sa_len < AF_MAX)
1374 			sa->sa_family = sa->sa_len;
1375 #endif
1376 		sa->sa_len = len;
1377 		*namp = sa;
1378 	}
1379 	return error;
1380 }
1381 
1382 /*
1383  * holdsock() - load the struct file pointer associated
1384  * with a socket into *fpp.  If an error occurs, non-zero
1385  * will be returned and *fpp will be set to NULL.
1386  */
1387 int
1388 holdsock(fdp, fdes, fpp)
1389 	struct filedesc *fdp;
1390 	int fdes;
1391 	struct file **fpp;
1392 {
1393 	register struct file *fp = NULL;
1394 	int error = 0;
1395 
1396 	if ((unsigned)fdes >= fdp->fd_nfiles ||
1397 	    (fp = fdp->fd_ofiles[fdes]) == NULL) {
1398 		error = EBADF;
1399 	} else if (fp->f_type != DTYPE_SOCKET) {
1400 		error = ENOTSOCK;
1401 		fp = NULL;
1402 	} else {
1403 		fhold(fp);
1404 	}
1405 	*fpp = fp;
1406 	return(error);
1407 }
1408 
1409 /*
1410  * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-))
1411  * XXX - The sf_buf functions are currently private to sendfile(2), so have
1412  * been made static, but may be useful in the future for doing zero-copy in
1413  * other parts of the networking code.
1414  */
1415 static void
1416 sf_buf_init(void *arg)
1417 {
1418 	int i;
1419 
1420 	mtx_init(&sf_freelist.sf_lock, "sf_bufs list lock", MTX_DEF);
1421 	mtx_enter(&sf_freelist.sf_lock, MTX_DEF);
1422 	SLIST_INIT(&sf_freelist);
1423 	sf_base = kmem_alloc_pageable(kernel_map, nsfbufs * PAGE_SIZE);
1424 	sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP, M_NOWAIT);
1425 	bzero(sf_bufs, nsfbufs * sizeof(struct sf_buf));
1426 	for (i = 0; i < nsfbufs; i++) {
1427 		sf_bufs[i].kva = sf_base + i * PAGE_SIZE;
1428 		SLIST_INSERT_HEAD(&sf_freelist, &sf_bufs[i], free_list);
1429 	}
1430 	sf_buf_alloc_want = 0;
1431 	mtx_exit(&sf_freelist.sf_lock, MTX_DEF);
1432 }
1433 
1434 /*
1435  * Get an sf_buf from the freelist. Will block if none are available.
1436  */
1437 static struct sf_buf *
1438 sf_buf_alloc()
1439 {
1440 	struct sf_buf *sf;
1441 
1442 	mtx_enter(&sf_freelist.sf_lock, MTX_DEF);
1443 	while ((sf = SLIST_FIRST(&sf_freelist)) == NULL) {
1444 		sf_buf_alloc_want++;
1445 		msleep(&sf_freelist, &sf_freelist.sf_lock, PVM, "sfbufa", 0);
1446 	}
1447 	SLIST_REMOVE_HEAD(&sf_freelist, free_list);
1448 	mtx_exit(&sf_freelist.sf_lock, MTX_DEF);
1449 	return (sf);
1450 }
1451 
1452 #define dtosf(x)	(&sf_bufs[((uintptr_t)(x) - (uintptr_t)sf_base) >> PAGE_SHIFT])
1453 
1454 /*
1455  * Detatch mapped page and release resources back to the system.
1456  */
1457 static void
1458 sf_buf_free(caddr_t addr, void *args)
1459 {
1460 	struct sf_buf *sf;
1461 	struct vm_page *m;
1462 	int s;
1463 
1464 	sf = dtosf(addr);
1465 	pmap_qremove((vm_offset_t)addr, 1);
1466 	m = sf->m;
1467 	s = splvm();
1468 	vm_page_unwire(m, 0);
1469 	/*
1470 	 * Check for the object going away on us. This can
1471 	 * happen since we don't hold a reference to it.
1472 	 * If so, we're responsible for freeing the page.
1473 	 */
1474 	if (m->wire_count == 0 && m->object == NULL)
1475 		vm_page_free(m);
1476 	splx(s);
1477 	sf->m = NULL;
1478 	mtx_enter(&sf_freelist.sf_lock, MTX_DEF);
1479 	SLIST_INSERT_HEAD(&sf_freelist, sf, free_list);
1480 	if (sf_buf_alloc_want) {
1481 		sf_buf_alloc_want--;
1482 		wakeup_one(&sf_freelist);
1483 	}
1484 	mtx_exit(&sf_freelist.sf_lock, MTX_DEF);
1485 }
1486 
1487 /*
1488  * sendfile(2)
1489  * int sendfile(int fd, int s, off_t offset, size_t nbytes,
1490  *	 struct sf_hdtr *hdtr, off_t *sbytes, int flags)
1491  *
1492  * Send a file specified by 'fd' and starting at 'offset' to a socket
1493  * specified by 's'. Send only 'nbytes' of the file or until EOF if
1494  * nbytes == 0. Optionally add a header and/or trailer to the socket
1495  * output. If specified, write the total number of bytes sent into *sbytes.
1496  */
1497 int
1498 sendfile(struct proc *p, struct sendfile_args *uap)
1499 {
1500 	struct file *fp;
1501 	struct filedesc *fdp = p->p_fd;
1502 	struct vnode *vp;
1503 	struct vm_object *obj;
1504 	struct socket *so;
1505 	struct mbuf *m;
1506 	struct sf_buf *sf;
1507 	struct vm_page *pg;
1508 	struct writev_args nuap;
1509 	struct sf_hdtr hdtr;
1510 	off_t off, xfsize, sbytes = 0;
1511 	int error = 0, s;
1512 
1513 	vp = NULL;
1514 	/*
1515 	 * Do argument checking. Must be a regular file in, stream
1516 	 * type and connected socket out, positive offset.
1517 	 */
1518 	fp = holdfp(fdp, uap->fd, FREAD);
1519 	if (fp == NULL) {
1520 		error = EBADF;
1521 		goto done;
1522 	}
1523 	if (fp->f_type != DTYPE_VNODE) {
1524 		error = EINVAL;
1525 		goto done;
1526 	}
1527 	vp = (struct vnode *)fp->f_data;
1528 	vref(vp);
1529 	if (vp->v_type != VREG || VOP_GETVOBJECT(vp, &obj) != 0) {
1530 		error = EINVAL;
1531 		goto done;
1532 	}
1533 	fdrop(fp, p);
1534 	error = holdsock(p->p_fd, uap->s, &fp);
1535 	if (error)
1536 		goto done;
1537 	so = (struct socket *)fp->f_data;
1538 	if (so->so_type != SOCK_STREAM) {
1539 		error = EINVAL;
1540 		goto done;
1541 	}
1542 	if ((so->so_state & SS_ISCONNECTED) == 0) {
1543 		error = ENOTCONN;
1544 		goto done;
1545 	}
1546 	if (uap->offset < 0) {
1547 		error = EINVAL;
1548 		goto done;
1549 	}
1550 
1551 	/*
1552 	 * If specified, get the pointer to the sf_hdtr struct for
1553 	 * any headers/trailers.
1554 	 */
1555 	if (uap->hdtr != NULL) {
1556 		error = copyin(uap->hdtr, &hdtr, sizeof(hdtr));
1557 		if (error)
1558 			goto done;
1559 		/*
1560 		 * Send any headers. Wimp out and use writev(2).
1561 		 */
1562 		if (hdtr.headers != NULL) {
1563 			nuap.fd = uap->s;
1564 			nuap.iovp = hdtr.headers;
1565 			nuap.iovcnt = hdtr.hdr_cnt;
1566 			error = writev(p, &nuap);
1567 			if (error)
1568 				goto done;
1569 			sbytes += p->p_retval[0];
1570 		}
1571 	}
1572 
1573 	/*
1574 	 * Protect against multiple writers to the socket.
1575 	 */
1576 	(void) sblock(&so->so_snd, M_WAITOK);
1577 
1578 	/*
1579 	 * Loop through the pages in the file, starting with the requested
1580 	 * offset. Get a file page (do I/O if necessary), map the file page
1581 	 * into an sf_buf, attach an mbuf header to the sf_buf, and queue
1582 	 * it on the socket.
1583 	 */
1584 	for (off = uap->offset; ; off += xfsize, sbytes += xfsize) {
1585 		vm_pindex_t pindex;
1586 		vm_offset_t pgoff;
1587 
1588 		pindex = OFF_TO_IDX(off);
1589 retry_lookup:
1590 		/*
1591 		 * Calculate the amount to transfer. Not to exceed a page,
1592 		 * the EOF, or the passed in nbytes.
1593 		 */
1594 		xfsize = obj->un_pager.vnp.vnp_size - off;
1595 		if (xfsize > PAGE_SIZE)
1596 			xfsize = PAGE_SIZE;
1597 		pgoff = (vm_offset_t)(off & PAGE_MASK);
1598 		if (PAGE_SIZE - pgoff < xfsize)
1599 			xfsize = PAGE_SIZE - pgoff;
1600 		if (uap->nbytes && xfsize > (uap->nbytes - sbytes))
1601 			xfsize = uap->nbytes - sbytes;
1602 		if (xfsize <= 0)
1603 			break;
1604 		/*
1605 		 * Optimize the non-blocking case by looking at the socket space
1606 		 * before going to the extra work of constituting the sf_buf.
1607 		 */
1608 		if ((so->so_state & SS_NBIO) && sbspace(&so->so_snd) <= 0) {
1609 			if (so->so_state & SS_CANTSENDMORE)
1610 				error = EPIPE;
1611 			else
1612 				error = EAGAIN;
1613 			sbunlock(&so->so_snd);
1614 			goto done;
1615 		}
1616 		/*
1617 		 * Attempt to look up the page.
1618 		 *
1619 		 *	Allocate if not found
1620 		 *
1621 		 *	Wait and loop if busy.
1622 		 */
1623 		pg = vm_page_lookup(obj, pindex);
1624 
1625 		if (pg == NULL) {
1626 			pg = vm_page_alloc(obj, pindex, VM_ALLOC_NORMAL);
1627 			if (pg == NULL) {
1628 				VM_WAIT;
1629 				goto retry_lookup;
1630 			}
1631 			vm_page_wakeup(pg);
1632 		} else if (vm_page_sleep_busy(pg, TRUE, "sfpbsy")) {
1633 			goto retry_lookup;
1634 		}
1635 
1636 		/*
1637 		 * Wire the page so it does not get ripped out from under
1638 		 * us.
1639 		 */
1640 
1641 		vm_page_wire(pg);
1642 
1643 		/*
1644 		 * If page is not valid for what we need, initiate I/O
1645 		 */
1646 
1647 		if (!pg->valid || !vm_page_is_valid(pg, pgoff, xfsize)) {
1648 			struct uio auio;
1649 			struct iovec aiov;
1650 			int bsize;
1651 
1652 			/*
1653 			 * Ensure that our page is still around when the I/O
1654 			 * completes.
1655 			 */
1656 			vm_page_io_start(pg);
1657 
1658 			/*
1659 			 * Get the page from backing store.
1660 			 */
1661 			bsize = vp->v_mount->mnt_stat.f_iosize;
1662 			auio.uio_iov = &aiov;
1663 			auio.uio_iovcnt = 1;
1664 			aiov.iov_base = 0;
1665 			aiov.iov_len = MAXBSIZE;
1666 			auio.uio_resid = MAXBSIZE;
1667 			auio.uio_offset = trunc_page(off);
1668 			auio.uio_segflg = UIO_NOCOPY;
1669 			auio.uio_rw = UIO_READ;
1670 			auio.uio_procp = p;
1671 			vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, p);
1672 			error = VOP_READ(vp, &auio, IO_VMIO | ((MAXBSIZE / bsize) << 16),
1673 			        p->p_ucred);
1674 			VOP_UNLOCK(vp, 0, p);
1675 			vm_page_flag_clear(pg, PG_ZERO);
1676 			vm_page_io_finish(pg);
1677 			if (error) {
1678 				vm_page_unwire(pg, 0);
1679 				/*
1680 				 * See if anyone else might know about this page.
1681 				 * If not and it is not valid, then free it.
1682 				 */
1683 				if (pg->wire_count == 0 && pg->valid == 0 &&
1684 				    pg->busy == 0 && !(pg->flags & PG_BUSY) &&
1685 				    pg->hold_count == 0) {
1686 					vm_page_busy(pg);
1687 					vm_page_free(pg);
1688 				}
1689 				sbunlock(&so->so_snd);
1690 				goto done;
1691 			}
1692 		}
1693 
1694 		/*
1695 		 * Allocate a kernel virtual page and insert the physical page
1696 		 * into it.
1697 		 */
1698 
1699 		sf = sf_buf_alloc();
1700 		sf->m = pg;
1701 		pmap_qenter(sf->kva, &pg, 1);
1702 		/*
1703 		 * Get an mbuf header and set it up as having external storage.
1704 		 */
1705 		MGETHDR(m, M_WAIT, MT_DATA);
1706 		if (m == NULL) {
1707 			error = ENOBUFS;
1708 			goto done;
1709 		}
1710 		/*
1711 		 * Setup external storage for mbuf.
1712 		 */
1713 		MEXTADD(m, sf->kva, PAGE_SIZE, sf_buf_free, NULL, M_RDONLY,
1714 		    EXT_SFBUF);
1715 		m->m_data = (char *) sf->kva + pgoff;
1716 		m->m_pkthdr.len = m->m_len = xfsize;
1717 		/*
1718 		 * Add the buffer to the socket buffer chain.
1719 		 */
1720 		s = splnet();
1721 retry_space:
1722 		/*
1723 		 * Make sure that the socket is still able to take more data.
1724 		 * CANTSENDMORE being true usually means that the connection
1725 		 * was closed. so_error is true when an error was sensed after
1726 		 * a previous send.
1727 		 * The state is checked after the page mapping and buffer
1728 		 * allocation above since those operations may block and make
1729 		 * any socket checks stale. From this point forward, nothing
1730 		 * blocks before the pru_send (or more accurately, any blocking
1731 		 * results in a loop back to here to re-check).
1732 		 */
1733 		if ((so->so_state & SS_CANTSENDMORE) || so->so_error) {
1734 			if (so->so_state & SS_CANTSENDMORE) {
1735 				error = EPIPE;
1736 			} else {
1737 				error = so->so_error;
1738 				so->so_error = 0;
1739 			}
1740 			m_freem(m);
1741 			sbunlock(&so->so_snd);
1742 			splx(s);
1743 			goto done;
1744 		}
1745 		/*
1746 		 * Wait for socket space to become available. We do this just
1747 		 * after checking the connection state above in order to avoid
1748 		 * a race condition with sbwait().
1749 		 */
1750 		if (sbspace(&so->so_snd) < so->so_snd.sb_lowat) {
1751 			if (so->so_state & SS_NBIO) {
1752 				m_freem(m);
1753 				sbunlock(&so->so_snd);
1754 				splx(s);
1755 				error = EAGAIN;
1756 				goto done;
1757 			}
1758 			error = sbwait(&so->so_snd);
1759 			/*
1760 			 * An error from sbwait usually indicates that we've
1761 			 * been interrupted by a signal. If we've sent anything
1762 			 * then return bytes sent, otherwise return the error.
1763 			 */
1764 			if (error) {
1765 				m_freem(m);
1766 				sbunlock(&so->so_snd);
1767 				splx(s);
1768 				goto done;
1769 			}
1770 			goto retry_space;
1771 		}
1772 		error = (*so->so_proto->pr_usrreqs->pru_send)(so, 0, m, 0, 0, p);
1773 		splx(s);
1774 		if (error) {
1775 			sbunlock(&so->so_snd);
1776 			goto done;
1777 		}
1778 	}
1779 	sbunlock(&so->so_snd);
1780 
1781 	/*
1782 	 * Send trailers. Wimp out and use writev(2).
1783 	 */
1784 	if (uap->hdtr != NULL && hdtr.trailers != NULL) {
1785 			nuap.fd = uap->s;
1786 			nuap.iovp = hdtr.trailers;
1787 			nuap.iovcnt = hdtr.trl_cnt;
1788 			error = writev(p, &nuap);
1789 			if (error)
1790 				goto done;
1791 			sbytes += p->p_retval[0];
1792 	}
1793 
1794 done:
1795 	if (uap->sbytes != NULL) {
1796 		copyout(&sbytes, uap->sbytes, sizeof(off_t));
1797 	}
1798 	if (vp)
1799 		vrele(vp);
1800 	if (fp)
1801 		fdrop(fp, p);
1802 	return (error);
1803 }
1804