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uipc_syscalls.c revision 1.112
      1 /*	$NetBSD: uipc_syscalls.c,v 1.112 2007/06/02 01:24:34 enami Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1982, 1986, 1989, 1990, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  *	@(#)uipc_syscalls.c	8.6 (Berkeley) 2/14/95
     32  */
     33 
     34 #include <sys/cdefs.h>
     35 __KERNEL_RCSID(0, "$NetBSD: uipc_syscalls.c,v 1.112 2007/06/02 01:24:34 enami Exp $");
     36 
     37 #include "opt_ktrace.h"
     38 #include "opt_pipe.h"
     39 
     40 #include <sys/param.h>
     41 #include <sys/systm.h>
     42 #include <sys/filedesc.h>
     43 #include <sys/proc.h>
     44 #include <sys/file.h>
     45 #include <sys/buf.h>
     46 #include <sys/malloc.h>
     47 #include <sys/mbuf.h>
     48 #include <sys/protosw.h>
     49 #include <sys/socket.h>
     50 #include <sys/socketvar.h>
     51 #include <sys/signalvar.h>
     52 #include <sys/un.h>
     53 #ifdef KTRACE
     54 #include <sys/ktrace.h>
     55 #endif
     56 #include <sys/event.h>
     57 
     58 #include <sys/mount.h>
     59 #include <sys/syscallargs.h>
     60 
     61 #include <uvm/uvm_extern.h>
     62 
     63 static void adjust_rights(struct mbuf *m, int len, struct lwp *l);
     64 
     65 /*
     66  * System call interface to the socket abstraction.
     67  */
     68 extern const struct fileops socketops;
     69 
     70 int
     71 sys___socket30(struct lwp *l, void *v, register_t *retval)
     72 {
     73 	struct sys___socket30_args /* {
     74 		syscallarg(int)	domain;
     75 		syscallarg(int)	type;
     76 		syscallarg(int)	protocol;
     77 	} */ *uap = v;
     78 
     79 	struct filedesc	*fdp;
     80 	struct socket	*so;
     81 	struct file	*fp;
     82 	int		fd, error;
     83 
     84 	fdp = l->l_proc->p_fd;
     85 	/* falloc() will use the desciptor for us */
     86 	if ((error = falloc(l, &fp, &fd)) != 0)
     87 		return (error);
     88 	fp->f_flag = FREAD|FWRITE;
     89 	fp->f_type = DTYPE_SOCKET;
     90 	fp->f_ops = &socketops;
     91 	error = socreate(SCARG(uap, domain), &so, SCARG(uap, type),
     92 			 SCARG(uap, protocol), l);
     93 	if (error) {
     94 		FILE_UNUSE(fp, l);
     95 		fdremove(fdp, fd);
     96 		ffree(fp);
     97 	} else {
     98 		fp->f_data = so;
     99 		FILE_SET_MATURE(fp);
    100 		FILE_UNUSE(fp, l);
    101 		*retval = fd;
    102 	}
    103 	return (error);
    104 }
    105 
    106 /* ARGSUSED */
    107 int
    108 sys_bind(struct lwp *l, void *v, register_t *retval)
    109 {
    110 	struct sys_bind_args /* {
    111 		syscallarg(int)				s;
    112 		syscallarg(const struct sockaddr *)	name;
    113 		syscallarg(unsigned int)		namelen;
    114 	} */ *uap = v;
    115 	struct mbuf	*nam;
    116 	int		error;
    117 
    118 	error = sockargs(&nam, SCARG(uap, name), SCARG(uap, namelen),
    119 	    MT_SONAME);
    120 	if (error)
    121 		return error;
    122 
    123 	return do_sys_bind(l, SCARG(uap, s), nam);
    124 }
    125 
    126 int
    127 do_sys_bind(struct lwp *l, int s, struct mbuf *nam)
    128 {
    129 	struct file	*fp;
    130 	int		error;
    131 
    132 	/* getsock() will use the descriptor for us */
    133 	if ((error = getsock(l->l_proc->p_fd, s, &fp)) != 0) {
    134 		m_freem(nam);
    135 		return (error);
    136 	}
    137 	MCLAIM(nam, ((struct socket *)fp->f_data)->so_mowner);
    138 	error = sobind(fp->f_data, nam, l);
    139 	m_freem(nam);
    140 	FILE_UNUSE(fp, l);
    141 	return error;
    142 }
    143 
    144 /* ARGSUSED */
    145 int
    146 sys_listen(struct lwp *l, void *v, register_t *retval)
    147 {
    148 	struct sys_listen_args /* {
    149 		syscallarg(int)	s;
    150 		syscallarg(int)	backlog;
    151 	} */ *uap = v;
    152 	struct file	*fp;
    153 	int		error;
    154 
    155 	/* getsock() will use the descriptor for us */
    156 	if ((error = getsock(l->l_proc->p_fd, SCARG(uap, s), &fp)) != 0)
    157 		return (error);
    158 	error = solisten(fp->f_data, SCARG(uap, backlog));
    159 	FILE_UNUSE(fp, l);
    160 	return error;
    161 }
    162 
    163 int
    164 sys_accept(struct lwp *l, void *v, register_t *retval)
    165 {
    166 	struct sys_accept_args /* {
    167 		syscallarg(int)			s;
    168 		syscallarg(struct sockaddr *)	name;
    169 		syscallarg(unsigned int *)	anamelen;
    170 	} */ *uap = v;
    171 	struct filedesc	*fdp;
    172 	struct file	*fp;
    173 	struct mbuf	*nam;
    174 	unsigned int	namelen;
    175 	int		error, s, fd;
    176 	struct socket	*so;
    177 	int		fflag;
    178 
    179 	fdp = l->l_proc->p_fd;
    180 	if (SCARG(uap, name) && (error = copyin(SCARG(uap, anamelen),
    181 	    &namelen, sizeof(namelen))))
    182 		return (error);
    183 
    184 	/* getsock() will use the descriptor for us */
    185 	if ((error = getsock(fdp, SCARG(uap, s), &fp)) != 0)
    186 		return (error);
    187 	s = splsoftnet();
    188 	so = (struct socket *)fp->f_data;
    189 	FILE_UNUSE(fp, l);
    190 	if (!(so->so_proto->pr_flags & PR_LISTEN)) {
    191 		splx(s);
    192 		return (EOPNOTSUPP);
    193 	}
    194 	if ((so->so_options & SO_ACCEPTCONN) == 0) {
    195 		splx(s);
    196 		return (EINVAL);
    197 	}
    198 	if ((so->so_state & SS_NBIO) && so->so_qlen == 0) {
    199 		splx(s);
    200 		return (EWOULDBLOCK);
    201 	}
    202 	while (so->so_qlen == 0 && so->so_error == 0) {
    203 		if (so->so_state & SS_CANTRCVMORE) {
    204 			so->so_error = ECONNABORTED;
    205 			break;
    206 		}
    207 		error = tsleep(&so->so_timeo, PSOCK | PCATCH,
    208 		    netcon, 0);
    209 		if (error) {
    210 			splx(s);
    211 			return (error);
    212 		}
    213 	}
    214 	if (so->so_error) {
    215 		error = so->so_error;
    216 		so->so_error = 0;
    217 		splx(s);
    218 		return (error);
    219 	}
    220 	fflag = fp->f_flag;
    221 	/* falloc() will use the descriptor for us */
    222 	if ((error = falloc(l, &fp, &fd)) != 0) {
    223 		splx(s);
    224 		return (error);
    225 	}
    226 	*retval = fd;
    227 
    228 	/* connection has been removed from the listen queue */
    229 	KNOTE(&so->so_rcv.sb_sel.sel_klist, 0);
    230 
    231 	{ struct socket *aso = TAILQ_FIRST(&so->so_q);
    232 	  if (soqremque(aso, 1) == 0)
    233 		panic("accept");
    234 	  so = aso;
    235 	}
    236 	fp->f_type = DTYPE_SOCKET;
    237 	fp->f_flag = fflag;
    238 	fp->f_ops = &socketops;
    239 	fp->f_data = so;
    240 	nam = m_get(M_WAIT, MT_SONAME);
    241 	if ((error = soaccept(so, nam)) == 0 && SCARG(uap, name)) {
    242 		if (namelen > nam->m_len)
    243 			namelen = nam->m_len;
    244 		/* SHOULD COPY OUT A CHAIN HERE */
    245 		error = copyout(mtod(nam, void *), SCARG(uap, name), namelen);
    246 		if (error == 0) {
    247 			error = copyout(&namelen, SCARG(uap, anamelen),
    248 			    sizeof(*SCARG(uap, anamelen)));
    249 		}
    250 	}
    251 	/* if an error occurred, free the file descriptor */
    252 	if (error) {
    253 		fdremove(fdp, fd);
    254 		closef(fp, l);
    255 	} else {
    256 		FILE_SET_MATURE(fp);
    257 		FILE_UNUSE(fp, l);
    258 	}
    259 	m_freem(nam);
    260 	splx(s);
    261 	return (error);
    262 }
    263 
    264 /* ARGSUSED */
    265 int
    266 sys_connect(struct lwp *l, void *v, register_t *retval)
    267 {
    268 	struct sys_connect_args /* {
    269 		syscallarg(int)				s;
    270 		syscallarg(const struct sockaddr *)	name;
    271 		syscallarg(unsigned int)		namelen;
    272 	} */ *uap = v;
    273 	int		error;
    274 	struct mbuf	*nam;
    275 
    276 	error = sockargs(&nam, SCARG(uap, name), SCARG(uap, namelen),
    277 	    MT_SONAME);
    278 	if (error)
    279 		return error;
    280 	return do_sys_connect(l,  SCARG(uap, s), nam);
    281 }
    282 
    283 int
    284 do_sys_connect(struct lwp *l, int s, struct mbuf *nam)
    285 {
    286 	struct file	*fp;
    287 	struct socket	*so;
    288 	int		error;
    289 	int		interrupted = 0;
    290 
    291 	/* getsock() will use the descriptor for us */
    292 	if ((error = getsock(l->l_proc->p_fd, s, &fp)) != 0) {
    293 		m_freem(nam);
    294 		return (error);
    295 	}
    296 	so = fp->f_data;
    297 	MCLAIM(nam, so->so_mowner);
    298 	if (so->so_state & SS_ISCONNECTING) {
    299 		error = EALREADY;
    300 		goto out;
    301 	}
    302 
    303 	error = soconnect(so, nam, l);
    304 	if (error)
    305 		goto bad;
    306 	if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
    307 		error = EINPROGRESS;
    308 		goto out;
    309 	}
    310 	s = splsoftnet();
    311 	while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
    312 		error = tsleep(&so->so_timeo, PSOCK | PCATCH,
    313 			       netcon, 0);
    314 		if (error) {
    315 			if (error == EINTR || error == ERESTART)
    316 				interrupted = 1;
    317 			break;
    318 		}
    319 	}
    320 	if (error == 0) {
    321 		error = so->so_error;
    322 		so->so_error = 0;
    323 	}
    324 	splx(s);
    325  bad:
    326 	if (!interrupted)
    327 		so->so_state &= ~SS_ISCONNECTING;
    328 	if (error == ERESTART)
    329 		error = EINTR;
    330  out:
    331 	FILE_UNUSE(fp, l);
    332 	m_freem(nam);
    333 	return (error);
    334 }
    335 
    336 int
    337 sys_socketpair(struct lwp *l, void *v, register_t *retval)
    338 {
    339 	struct sys_socketpair_args /* {
    340 		syscallarg(int)		domain;
    341 		syscallarg(int)		type;
    342 		syscallarg(int)		protocol;
    343 		syscallarg(int *)	rsv;
    344 	} */ *uap = v;
    345 	struct filedesc	*fdp;
    346 	struct file	*fp1, *fp2;
    347 	struct socket	*so1, *so2;
    348 	int		fd, error, sv[2];
    349 
    350 	fdp = l->l_proc->p_fd;
    351 	error = socreate(SCARG(uap, domain), &so1, SCARG(uap, type),
    352 	    SCARG(uap, protocol), l);
    353 	if (error)
    354 		return (error);
    355 	error = socreate(SCARG(uap, domain), &so2, SCARG(uap, type),
    356 	    SCARG(uap, protocol), l);
    357 	if (error)
    358 		goto free1;
    359 	/* falloc() will use the descriptor for us */
    360 	if ((error = falloc(l, &fp1, &fd)) != 0)
    361 		goto free2;
    362 	sv[0] = fd;
    363 	fp1->f_flag = FREAD|FWRITE;
    364 	fp1->f_type = DTYPE_SOCKET;
    365 	fp1->f_ops = &socketops;
    366 	fp1->f_data = so1;
    367 	if ((error = falloc(l, &fp2, &fd)) != 0)
    368 		goto free3;
    369 	fp2->f_flag = FREAD|FWRITE;
    370 	fp2->f_type = DTYPE_SOCKET;
    371 	fp2->f_ops = &socketops;
    372 	fp2->f_data = so2;
    373 	sv[1] = fd;
    374 	if ((error = soconnect2(so1, so2)) != 0)
    375 		goto free4;
    376 	if (SCARG(uap, type) == SOCK_DGRAM) {
    377 		/*
    378 		 * Datagram socket connection is asymmetric.
    379 		 */
    380 		 if ((error = soconnect2(so2, so1)) != 0)
    381 			goto free4;
    382 	}
    383 	error = copyout(sv, SCARG(uap, rsv), 2 * sizeof(int));
    384 	FILE_SET_MATURE(fp1);
    385 	FILE_SET_MATURE(fp2);
    386 	FILE_UNUSE(fp1, l);
    387 	FILE_UNUSE(fp2, l);
    388 	return (error);
    389  free4:
    390 	FILE_UNUSE(fp2, l);
    391 	ffree(fp2);
    392 	fdremove(fdp, sv[1]);
    393  free3:
    394 	FILE_UNUSE(fp1, l);
    395 	ffree(fp1);
    396 	fdremove(fdp, sv[0]);
    397  free2:
    398 	(void)soclose(so2);
    399  free1:
    400 	(void)soclose(so1);
    401 	return (error);
    402 }
    403 
    404 int
    405 sys_sendto(struct lwp *l, void *v, register_t *retval)
    406 {
    407 	struct sys_sendto_args /* {
    408 		syscallarg(int)				s;
    409 		syscallarg(const void *)		buf;
    410 		syscallarg(size_t)			len;
    411 		syscallarg(int)				flags;
    412 		syscallarg(const struct sockaddr *)	to;
    413 		syscallarg(unsigned int)		tolen;
    414 	} */ *uap = v;
    415 	struct msghdr	msg;
    416 	struct iovec	aiov;
    417 
    418 	msg.msg_name = __UNCONST(SCARG(uap, to)); /* XXXUNCONST kills const */
    419 	msg.msg_namelen = SCARG(uap, tolen);
    420 	msg.msg_iov = &aiov;
    421 	msg.msg_iovlen = 1;
    422 	msg.msg_control = 0;
    423 	msg.msg_flags = 0;
    424 	aiov.iov_base = __UNCONST(SCARG(uap, buf)); /* XXXUNCONST kills const */
    425 	aiov.iov_len = SCARG(uap, len);
    426 	return do_sys_sendmsg(l, SCARG(uap, s), &msg, SCARG(uap, flags), retval);
    427 }
    428 
    429 int
    430 sys_sendmsg(struct lwp *l, void *v, register_t *retval)
    431 {
    432 	struct sys_sendmsg_args /* {
    433 		syscallarg(int)				s;
    434 		syscallarg(const struct msghdr *)	msg;
    435 		syscallarg(int)				flags;
    436 	} */ *uap = v;
    437 	struct msghdr	msg;
    438 	int		error;
    439 
    440 	error = copyin(SCARG(uap, msg), &msg, sizeof(msg));
    441 	if (error)
    442 		return (error);
    443 
    444 	msg.msg_flags = MSG_IOVUSRSPACE;
    445 	return do_sys_sendmsg(l, SCARG(uap, s), &msg, SCARG(uap, flags), retval);
    446 }
    447 
    448 int
    449 do_sys_sendmsg(struct lwp *l, int s, struct msghdr *mp, int flags,
    450 		register_t *retsize)
    451 {
    452 	struct file	*fp;
    453 	struct uio	auio;
    454 	int		i, len, error;
    455 	struct mbuf	*to, *control;
    456 	struct socket	*so;
    457 	struct iovec	*tiov;
    458 	struct iovec	aiov[UIO_SMALLIOV], *iov = aiov;
    459 #ifdef KTRACE
    460 	struct iovec	*ktriov;
    461 #endif
    462 
    463 	/* If the caller passed us stuff in mbufs, we must free them */
    464 	if (mp->msg_flags & MSG_NAMEMBUF)
    465 		to = mp->msg_name;
    466 	else
    467 		to = NULL;
    468 
    469 	if (mp->msg_flags & MSG_CONTROLMBUF)
    470 		control = mp->msg_control;
    471 	else
    472 		control = NULL;
    473 
    474 	if (mp->msg_flags & MSG_IOVUSRSPACE) {
    475 		if ((unsigned int)mp->msg_iovlen > UIO_SMALLIOV) {
    476 			if ((unsigned int)mp->msg_iovlen > IOV_MAX) {
    477 				error = EMSGSIZE;
    478 				goto bad;
    479 			}
    480 			iov = malloc(sizeof(struct iovec) * mp->msg_iovlen,
    481 			    M_IOV, M_WAITOK);
    482 		}
    483 		if (mp->msg_iovlen != 0) {
    484 			error = copyin(mp->msg_iov, iov,
    485 			    (size_t)(mp->msg_iovlen * sizeof(struct iovec)));
    486 			if (error)
    487 				goto bad;
    488 		}
    489 		mp->msg_iov = iov;
    490 	}
    491 
    492 #ifdef KTRACE
    493 	ktriov = NULL;
    494 #endif
    495 
    496 	auio.uio_iov = mp->msg_iov;
    497 	auio.uio_iovcnt = mp->msg_iovlen;
    498 	auio.uio_rw = UIO_WRITE;
    499 	auio.uio_offset = 0;			/* XXX */
    500 	auio.uio_resid = 0;
    501 	KASSERT(l == curlwp);
    502 	auio.uio_vmspace = l->l_proc->p_vmspace;
    503 
    504 	for (i = 0, tiov = mp->msg_iov; i < mp->msg_iovlen; i++, tiov++) {
    505 #if 0
    506 		/* cannot happen; iov_len is unsigned */
    507 		if (tiov->iov_len < 0) {
    508 			error = EINVAL;
    509 			goto bad;
    510 		}
    511 #endif
    512 		/*
    513 		 * Writes return ssize_t because -1 is returned on error.
    514 		 * Therefore, we must restrict the length to SSIZE_MAX to
    515 		 * avoid garbage return values.
    516 		 */
    517 		auio.uio_resid += tiov->iov_len;
    518 		if (tiov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) {
    519 			error = EINVAL;
    520 			goto bad;
    521 		}
    522 	}
    523 
    524 	if (mp->msg_name && to == NULL) {
    525 		error = sockargs(&to, mp->msg_name, mp->msg_namelen,
    526 		    MT_SONAME);
    527 		if (error)
    528 			goto bad;
    529 	}
    530 
    531 	if (mp->msg_control) {
    532 		if (mp->msg_controllen < CMSG_ALIGN(sizeof(struct cmsghdr))) {
    533 			error = EINVAL;
    534 			goto bad;
    535 		}
    536 		if (control == NULL) {
    537 			error = sockargs(&control, mp->msg_control,
    538 			    mp->msg_controllen, MT_CONTROL);
    539 			if (error)
    540 				goto bad;
    541 		}
    542 	}
    543 
    544 #ifdef KTRACE
    545 	if (KTRPOINT(l->l_proc, KTR_GENIO)) {
    546 		int iovlen = auio.uio_iovcnt * sizeof(struct iovec);
    547 
    548 		ktriov = malloc(iovlen, M_TEMP, M_WAITOK);
    549 		memcpy(ktriov, auio.uio_iov, iovlen);
    550 	}
    551 #endif
    552 
    553 	/* getsock() will use the descriptor for us */
    554 	if ((error = getsock(l->l_proc->p_fd, s, &fp)) != 0)
    555 		goto bad;
    556 	so = (struct socket *)fp->f_data;
    557 
    558 	if (mp->msg_name)
    559 		MCLAIM(to, so->so_mowner);
    560 	if (mp->msg_control)
    561 		MCLAIM(control, so->so_mowner);
    562 
    563 	len = auio.uio_resid;
    564 	error = (*so->so_send)(so, to, &auio, NULL, control, flags, l);
    565 	/* Protocol is responsible for freeing 'control' */
    566 	control = NULL;
    567 
    568 	FILE_UNUSE(fp, l);
    569 
    570 	if (error) {
    571 		if (auio.uio_resid != len && (error == ERESTART ||
    572 		    error == EINTR || error == EWOULDBLOCK))
    573 			error = 0;
    574 		if (error == EPIPE && (flags & MSG_NOSIGNAL) == 0) {
    575 			mutex_enter(&proclist_mutex);
    576 			psignal(l->l_proc, SIGPIPE);
    577 			mutex_exit(&proclist_mutex);
    578 		}
    579 	}
    580 	if (error == 0)
    581 		*retsize = len - auio.uio_resid;
    582 
    583 #ifdef KTRACE
    584 	if (ktriov != NULL) {
    585 		if (error == 0)
    586 			ktrgenio(l, s, UIO_WRITE, ktriov, *retsize, error);
    587 		free(ktriov, M_TEMP);
    588 	}
    589 #endif
    590 
    591  bad:
    592 	if (iov != aiov)
    593 		free(iov, M_IOV);
    594 	if (to)
    595 		m_freem(to);
    596 	if (control != NULL)
    597 		m_freem(control);
    598 
    599 	return (error);
    600 }
    601 
    602 int
    603 sys_recvfrom(struct lwp *l, void *v, register_t *retval)
    604 {
    605 	struct sys_recvfrom_args /* {
    606 		syscallarg(int)			s;
    607 		syscallarg(void *)		buf;
    608 		syscallarg(size_t)		len;
    609 		syscallarg(int)			flags;
    610 		syscallarg(struct sockaddr *)	from;
    611 		syscallarg(unsigned int *)	fromlenaddr;
    612 	} */ *uap = v;
    613 	struct msghdr	msg;
    614 	struct iovec	aiov;
    615 	int		error;
    616 
    617 	if (SCARG(uap, fromlenaddr)) {
    618 		error = copyin(SCARG(uap, fromlenaddr), &msg.msg_namelen,
    619 			       sizeof(msg.msg_namelen));
    620 		if (error)
    621 			return (error);
    622 	} else
    623 		msg.msg_namelen = 0;
    624 	msg.msg_name = SCARG(uap, from);
    625 	msg.msg_iov = &aiov;
    626 	msg.msg_iovlen = 1;
    627 	aiov.iov_base = SCARG(uap, buf);
    628 	aiov.iov_len = SCARG(uap, len);
    629 	msg.msg_control = 0;
    630 	msg.msg_flags = SCARG(uap, flags);
    631 	return recvit(l, SCARG(uap, s), &msg, SCARG(uap, fromlenaddr), retval);
    632 }
    633 
    634 int
    635 sys_recvmsg(struct lwp *l, void *v, register_t *retval)
    636 {
    637 	struct sys_recvmsg_args /* {
    638 		syscallarg(int)			s;
    639 		syscallarg(struct msghdr *)	msg;
    640 		syscallarg(int)			flags;
    641 	} */ *uap = v;
    642 	struct iovec	aiov[UIO_SMALLIOV], *uiov, *iov;
    643 	struct msghdr	msg;
    644 	int		error;
    645 
    646 	error = copyin(SCARG(uap, msg), &msg, sizeof(msg));
    647 	if (error)
    648 		return (error);
    649 	if ((unsigned int)msg.msg_iovlen > UIO_SMALLIOV) {
    650 		if ((unsigned int)msg.msg_iovlen > IOV_MAX)
    651 			return (EMSGSIZE);
    652 		iov = malloc(sizeof(struct iovec) * msg.msg_iovlen,
    653 		    M_IOV, M_WAITOK);
    654 	} else
    655 		iov = aiov;
    656 	if ((unsigned int)msg.msg_iovlen > 0) {
    657 		error = copyin(msg.msg_iov, iov,
    658 		    (size_t)(msg.msg_iovlen * sizeof(struct iovec)));
    659 		if (error)
    660 			goto done;
    661 	}
    662 	uiov = msg.msg_iov;
    663 	msg.msg_iov = iov;
    664 	msg.msg_flags = SCARG(uap, flags);
    665 	if ((error = recvit(l, SCARG(uap, s), &msg, NULL, retval)) == 0) {
    666 		msg.msg_iov = uiov;
    667 		error = copyout(&msg, SCARG(uap, msg), sizeof(msg));
    668 	}
    669 done:
    670 	if (iov != aiov)
    671 		free(iov, M_IOV);
    672 	return (error);
    673 }
    674 
    675 /*
    676  * Adjust for a truncated SCM_RIGHTS control message.  This means
    677  *  closing any file descriptors that aren't entirely present in the
    678  *  returned buffer.  m is the mbuf holding the (already externalized)
    679  *  SCM_RIGHTS message; len is the length it is being truncated to.  p
    680  *  is the affected process.
    681  */
    682 static void
    683 adjust_rights(struct mbuf *m, int len, struct lwp *l)
    684 {
    685 	int nfd;
    686 	int i;
    687 	int nok;
    688 	int *fdv;
    689 
    690 	nfd = m->m_len < CMSG_SPACE(sizeof(int)) ? 0
    691 	    : (m->m_len - CMSG_SPACE(sizeof(int))) / sizeof(int) + 1;
    692 	nok = (len < CMSG_LEN(0)) ? 0 : ((len - CMSG_LEN(0)) / sizeof(int));
    693 	fdv = (int *) CMSG_DATA(mtod(m,struct cmsghdr *));
    694 	for (i = nok; i < nfd; i++)
    695 		fdrelease(l,fdv[i]);
    696 }
    697 
    698 int
    699 recvit(struct lwp *l, int s, struct msghdr *mp, void *namelenp,
    700 	register_t *retsize)
    701 {
    702 	struct proc	*p;
    703 	struct file	*fp;
    704 	struct uio	auio;
    705 	struct iovec	*iov;
    706 	int		i, len, error;
    707 	struct mbuf	*from, *control;
    708 	struct socket	*so;
    709 #ifdef KTRACE
    710 	struct iovec	*ktriov;
    711 #endif
    712 
    713 	p = l->l_proc;
    714 	from = 0;
    715 	control = 0;
    716 #ifdef KTRACE
    717 	ktriov = NULL;
    718 #endif
    719 
    720 	/* getsock() will use the descriptor for us */
    721 	if ((error = getsock(p->p_fd, s, &fp)) != 0)
    722 		return (error);
    723 	so = (struct socket *)fp->f_data;
    724 	auio.uio_iov = mp->msg_iov;
    725 	auio.uio_iovcnt = mp->msg_iovlen;
    726 	auio.uio_rw = UIO_READ;
    727 	auio.uio_offset = 0;			/* XXX */
    728 	auio.uio_resid = 0;
    729 	KASSERT(l == curlwp);
    730 	auio.uio_vmspace = l->l_proc->p_vmspace;
    731 	iov = mp->msg_iov;
    732 	for (i = 0; i < mp->msg_iovlen; i++, iov++) {
    733 #if 0
    734 		/* cannot happen iov_len is unsigned */
    735 		if (iov->iov_len < 0) {
    736 			error = EINVAL;
    737 			goto out1;
    738 		}
    739 #endif
    740 		/*
    741 		 * Reads return ssize_t because -1 is returned on error.
    742 		 * Therefore we must restrict the length to SSIZE_MAX to
    743 		 * avoid garbage return values.
    744 		 */
    745 		auio.uio_resid += iov->iov_len;
    746 		if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) {
    747 			error = EINVAL;
    748 			goto out1;
    749 		}
    750 	}
    751 #ifdef KTRACE
    752 	if (KTRPOINT(p, KTR_GENIO)) {
    753 		int iovlen = auio.uio_iovcnt * sizeof(struct iovec);
    754 
    755 		ktriov = malloc(iovlen, M_TEMP, M_WAITOK);
    756 		memcpy(ktriov, auio.uio_iov, iovlen);
    757 	}
    758 #endif
    759 	len = auio.uio_resid;
    760 	error = (*so->so_receive)(so, &from, &auio, NULL,
    761 			  mp->msg_control ? &control : NULL, &mp->msg_flags);
    762 	if (error) {
    763 		if (auio.uio_resid != len && (error == ERESTART ||
    764 		    error == EINTR || error == EWOULDBLOCK))
    765 			error = 0;
    766 	}
    767 #ifdef KTRACE
    768 	if (ktriov != NULL) {
    769 		if (error == 0)
    770 			ktrgenio(l, s, UIO_READ, ktriov,
    771 			    len - auio.uio_resid, error);
    772 		free(ktriov, M_TEMP);
    773 	}
    774 #endif
    775 	if (error)
    776 		goto out;
    777 	*retsize = len - auio.uio_resid;
    778 	if (mp->msg_name) {
    779 		len = mp->msg_namelen;
    780 		if (len <= 0 || from == 0)
    781 			len = 0;
    782 		else {
    783 			if (len > from->m_len)
    784 				len = from->m_len;
    785 			/* else if len < from->m_len ??? */
    786 			error = copyout(mtod(from, void *),
    787 					mp->msg_name, (unsigned)len);
    788 			if (error)
    789 				goto out;
    790 		}
    791 		mp->msg_namelen = len;
    792 		if (namelenp &&
    793 		    (error = copyout(&len, namelenp, sizeof(int))))
    794 			goto out;
    795 	}
    796 	if (mp->msg_control) {
    797 		len = mp->msg_controllen;
    798 		if (len <= 0 || control == 0)
    799 			len = 0;
    800 		else {
    801 			struct mbuf *m = control;
    802 			char *q = (char *)mp->msg_control;
    803 
    804 			do {
    805 				i = m->m_len;
    806 				if (len < i) {
    807 					mp->msg_flags |= MSG_CTRUNC;
    808 					i = len;
    809 					if (mtod(m, struct cmsghdr *)->
    810 					    cmsg_type == SCM_RIGHTS)
    811 						adjust_rights(m, len, l);
    812 				}
    813 				error = copyout(mtod(m, void *), q,
    814 				    (unsigned)i);
    815 				m = m->m_next;
    816 				if (m)
    817 					i = ALIGN(i);
    818 				q += i;
    819 				len -= i;
    820 				if (error != 0 || len <= 0)
    821 					break;
    822 			} while (m != NULL);
    823 			while (m) {
    824 				if (mtod(m, struct cmsghdr *)->
    825 				    cmsg_type == SCM_RIGHTS)
    826 					adjust_rights(m, 0, l);
    827 				m = m->m_next;
    828 			}
    829 			len = q - (char *)mp->msg_control;
    830 		}
    831 		mp->msg_controllen = len;
    832 	}
    833  out:
    834 	if (from)
    835 		m_freem(from);
    836 	if (control)
    837 		m_freem(control);
    838  out1:
    839 	FILE_UNUSE(fp, l);
    840 	return (error);
    841 }
    842 
    843 /* ARGSUSED */
    844 int
    845 sys_shutdown(struct lwp *l, void *v, register_t *retval)
    846 {
    847 	struct sys_shutdown_args /* {
    848 		syscallarg(int)	s;
    849 		syscallarg(int)	how;
    850 	} */ *uap = v;
    851 	struct proc	*p;
    852 	struct file	*fp;
    853 	int		error;
    854 
    855 	p = l->l_proc;
    856 	/* getsock() will use the descriptor for us */
    857 	if ((error = getsock(p->p_fd, SCARG(uap, s), &fp)) != 0)
    858 		return (error);
    859 	error = soshutdown((struct socket *)fp->f_data, SCARG(uap, how));
    860 	FILE_UNUSE(fp, l);
    861 	return (error);
    862 }
    863 
    864 /* ARGSUSED */
    865 int
    866 sys_setsockopt(struct lwp *l, void *v, register_t *retval)
    867 {
    868 	struct sys_setsockopt_args /* {
    869 		syscallarg(int)			s;
    870 		syscallarg(int)			level;
    871 		syscallarg(int)			name;
    872 		syscallarg(const void *)	val;
    873 		syscallarg(unsigned int)	valsize;
    874 	} */ *uap = v;
    875 	struct proc	*p;
    876 	struct file	*fp;
    877 	struct mbuf	*m;
    878 	struct socket	*so;
    879 	int		error;
    880 	unsigned int	len;
    881 
    882 	p = l->l_proc;
    883 	m = NULL;
    884 	/* getsock() will use the descriptor for us */
    885 	if ((error = getsock(p->p_fd, SCARG(uap, s), &fp)) != 0)
    886 		return (error);
    887 	so = (struct socket *)fp->f_data;
    888 	len = SCARG(uap, valsize);
    889 	if (len > MCLBYTES) {
    890 		error = EINVAL;
    891 		goto out;
    892 	}
    893 	if (SCARG(uap, val)) {
    894 		m = m_get(M_WAIT, MT_SOOPTS);
    895 		MCLAIM(m, so->so_mowner);
    896 		if (len > MLEN)
    897 			m_clget(m, M_WAIT);
    898 		error = copyin(SCARG(uap, val), mtod(m, void *), len);
    899 		if (error) {
    900 			(void) m_free(m);
    901 			goto out;
    902 		}
    903 		m->m_len = SCARG(uap, valsize);
    904 	}
    905 	error = sosetopt(so, SCARG(uap, level), SCARG(uap, name), m);
    906  out:
    907 	FILE_UNUSE(fp, l);
    908 	return (error);
    909 }
    910 
    911 /* ARGSUSED */
    912 int
    913 sys_getsockopt(struct lwp *l, void *v, register_t *retval)
    914 {
    915 	struct sys_getsockopt_args /* {
    916 		syscallarg(int)			s;
    917 		syscallarg(int)			level;
    918 		syscallarg(int)			name;
    919 		syscallarg(void *)		val;
    920 		syscallarg(unsigned int *)	avalsize;
    921 	} */ *uap = v;
    922 	struct file	*fp;
    923 	struct mbuf	*m;
    924 	unsigned int	op, i, valsize;
    925 	int		error;
    926 
    927 	m = NULL;
    928 	/* getsock() will use the descriptor for us */
    929 	if ((error = getsock(l->l_proc->p_fd, SCARG(uap, s), &fp)) != 0)
    930 		return (error);
    931 	if (SCARG(uap, val)) {
    932 		error = copyin(SCARG(uap, avalsize),
    933 			       &valsize, sizeof(valsize));
    934 		if (error)
    935 			goto out;
    936 	} else
    937 		valsize = 0;
    938 	if ((error = sogetopt((struct socket *)fp->f_data, SCARG(uap, level),
    939 	    SCARG(uap, name), &m)) == 0 && SCARG(uap, val) && valsize &&
    940 	    m != NULL) {
    941 		op = 0;
    942 		while (m && !error && op < valsize) {
    943 			i = min(m->m_len, (valsize - op));
    944 			error = copyout(mtod(m, void *), SCARG(uap, val), i);
    945 			op += i;
    946 			SCARG(uap, val) = ((uint8_t *)SCARG(uap, val)) + i;
    947 			m = m_free(m);
    948 		}
    949 		valsize = op;
    950 		if (error == 0)
    951 			error = copyout(&valsize,
    952 					SCARG(uap, avalsize), sizeof(valsize));
    953 	}
    954 	if (m != NULL)
    955 		(void) m_freem(m);
    956  out:
    957 	FILE_UNUSE(fp, l);
    958 	return (error);
    959 }
    960 
    961 #ifdef PIPE_SOCKETPAIR
    962 /* ARGSUSED */
    963 int
    964 sys_pipe(struct lwp *l, void *v, register_t *retval)
    965 {
    966 	struct filedesc	*fdp;
    967 	struct file	*rf, *wf;
    968 	struct socket	*rso, *wso;
    969 	int		fd, error;
    970 
    971 	fdp = l->l_proc->p_fd;
    972 	if ((error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, l)) != 0)
    973 		return (error);
    974 	if ((error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, l)) != 0)
    975 		goto free1;
    976 	/* remember this socket pair implements a pipe */
    977 	wso->so_state |= SS_ISAPIPE;
    978 	rso->so_state |= SS_ISAPIPE;
    979 	/* falloc() will use the descriptor for us */
    980 	if ((error = falloc(l, &rf, &fd)) != 0)
    981 		goto free2;
    982 	retval[0] = fd;
    983 	rf->f_flag = FREAD;
    984 	rf->f_type = DTYPE_SOCKET;
    985 	rf->f_ops = &socketops;
    986 	rf->f_data = rso;
    987 	if ((error = falloc(l, &wf, &fd)) != 0)
    988 		goto free3;
    989 	wf->f_flag = FWRITE;
    990 	wf->f_type = DTYPE_SOCKET;
    991 	wf->f_ops = &socketops;
    992 	wf->f_data = wso;
    993 	retval[1] = fd;
    994 	if ((error = unp_connect2(wso, rso, PRU_CONNECT2)) != 0)
    995 		goto free4;
    996 	FILE_SET_MATURE(rf);
    997 	FILE_SET_MATURE(wf);
    998 	FILE_UNUSE(rf, l);
    999 	FILE_UNUSE(wf, l);
   1000 	return (0);
   1001  free4:
   1002 	FILE_UNUSE(wf, l);
   1003 	ffree(wf);
   1004 	fdremove(fdp, retval[1]);
   1005  free3:
   1006 	FILE_UNUSE(rf, l);
   1007 	ffree(rf);
   1008 	fdremove(fdp, retval[0]);
   1009  free2:
   1010 	(void)soclose(wso);
   1011  free1:
   1012 	(void)soclose(rso);
   1013 	return (error);
   1014 }
   1015 #endif /* PIPE_SOCKETPAIR */
   1016 
   1017 /*
   1018  * Get socket name.
   1019  */
   1020 /* ARGSUSED */
   1021 int
   1022 sys_getsockname(struct lwp *l, void *v, register_t *retval)
   1023 {
   1024 	struct sys_getsockname_args /* {
   1025 		syscallarg(int)			fdes;
   1026 		syscallarg(struct sockaddr *)	asa;
   1027 		syscallarg(unsigned int *)	alen;
   1028 	} */ *uap = v;
   1029 	struct proc	*p;
   1030 	struct file	*fp;
   1031 	struct socket	*so;
   1032 	struct mbuf	*m;
   1033 	unsigned int	len;
   1034 	int		error;
   1035 
   1036 	p = l->l_proc;
   1037 	/* getsock() will use the descriptor for us */
   1038 	if ((error = getsock(p->p_fd, SCARG(uap, fdes), &fp)) != 0)
   1039 		return (error);
   1040 	error = copyin(SCARG(uap, alen), &len, sizeof(len));
   1041 	if (error)
   1042 		goto out;
   1043 	so = (struct socket *)fp->f_data;
   1044 	m = m_getclr(M_WAIT, MT_SONAME);
   1045 	MCLAIM(m, so->so_mowner);
   1046 	error = (*so->so_proto->pr_usrreq)(so, PRU_SOCKADDR, (struct mbuf *)0,
   1047 	    m, (struct mbuf *)0, (struct lwp *)0);
   1048 	if (error)
   1049 		goto bad;
   1050 	if (len > m->m_len)
   1051 		len = m->m_len;
   1052 	error = copyout(mtod(m, void *), SCARG(uap, asa), len);
   1053 	if (error == 0)
   1054 		error = copyout(&len, SCARG(uap, alen), sizeof(len));
   1055  bad:
   1056 	m_freem(m);
   1057  out:
   1058 	FILE_UNUSE(fp, l);
   1059 	return (error);
   1060 }
   1061 
   1062 /*
   1063  * Get name of peer for connected socket.
   1064  */
   1065 /* ARGSUSED */
   1066 int
   1067 sys_getpeername(struct lwp *l, void *v, register_t *retval)
   1068 {
   1069 	struct sys_getpeername_args /* {
   1070 		syscallarg(int)			fdes;
   1071 		syscallarg(struct sockaddr *)	asa;
   1072 		syscallarg(unsigned int *)	alen;
   1073 	} */ *uap = v;
   1074 	struct proc	*p;
   1075 	struct file	*fp;
   1076 	struct socket	*so;
   1077 	struct mbuf	*m;
   1078 	unsigned int	len;
   1079 	int		error;
   1080 
   1081 	p = l->l_proc;
   1082 	/* getsock() will use the descriptor for us */
   1083 	if ((error = getsock(p->p_fd, SCARG(uap, fdes), &fp)) != 0)
   1084 		return (error);
   1085 	so = (struct socket *)fp->f_data;
   1086 	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
   1087 		error = ENOTCONN;
   1088 		goto out;
   1089 	}
   1090 	error = copyin(SCARG(uap, alen), &len, sizeof(len));
   1091 	if (error)
   1092 		goto out;
   1093 	m = m_getclr(M_WAIT, MT_SONAME);
   1094 	MCLAIM(m, so->so_mowner);
   1095 	error = (*so->so_proto->pr_usrreq)(so, PRU_PEERADDR, (struct mbuf *)0,
   1096 	    m, (struct mbuf *)0, (struct lwp *)0);
   1097 	if (error)
   1098 		goto bad;
   1099 	if (len > m->m_len)
   1100 		len = m->m_len;
   1101 	error = copyout(mtod(m, void *), SCARG(uap, asa), len);
   1102 	if (error)
   1103 		goto bad;
   1104 	error = copyout(&len, SCARG(uap, alen), sizeof(len));
   1105  bad:
   1106 	m_freem(m);
   1107  out:
   1108 	FILE_UNUSE(fp, l);
   1109 	return (error);
   1110 }
   1111 
   1112 /*
   1113  * XXX In a perfect world, we wouldn't pass around socket control
   1114  * XXX arguments in mbufs, and this could go away.
   1115  */
   1116 int
   1117 sockargs(struct mbuf **mp, const void *bf, size_t buflen, int type)
   1118 {
   1119 	struct sockaddr	*sa;
   1120 	struct mbuf	*m;
   1121 	int		error;
   1122 
   1123 	/*
   1124 	 * We can't allow socket names > UCHAR_MAX in length, since that
   1125 	 * will overflow sa_len.  Control data more than a page size in
   1126 	 * length is just too much.
   1127 	 */
   1128 	if (buflen > (type == MT_SONAME ? UCHAR_MAX : PAGE_SIZE))
   1129 		return (EINVAL);
   1130 
   1131 	/* Allocate an mbuf to hold the arguments. */
   1132 	m = m_get(M_WAIT, type);
   1133 	/* can't claim.  don't who to assign it to. */
   1134 	if (buflen > MLEN) {
   1135 		/*
   1136 		 * Won't fit into a regular mbuf, so we allocate just
   1137 		 * enough external storage to hold the argument.
   1138 		 */
   1139 		MEXTMALLOC(m, buflen, M_WAITOK);
   1140 	}
   1141 	m->m_len = buflen;
   1142 	error = copyin(bf, mtod(m, void *), buflen);
   1143 	if (error) {
   1144 		(void) m_free(m);
   1145 		return (error);
   1146 	}
   1147 	*mp = m;
   1148 	if (type == MT_SONAME) {
   1149 		sa = mtod(m, struct sockaddr *);
   1150 #if BYTE_ORDER != BIG_ENDIAN
   1151 		/*
   1152 		 * 4.3BSD compat thing - need to stay, since bind(2),
   1153 		 * connect(2), sendto(2) were not versioned for COMPAT_43.
   1154 		 */
   1155 		if (sa->sa_family == 0 && sa->sa_len < AF_MAX)
   1156 			sa->sa_family = sa->sa_len;
   1157 #endif
   1158 		sa->sa_len = buflen;
   1159 	}
   1160 	return (0);
   1161 }
   1162 
   1163 int
   1164 getsock(struct filedesc *fdp, int fdes, struct file **fpp)
   1165 {
   1166 	struct file	*fp;
   1167 
   1168 	if ((fp = fd_getfile(fdp, fdes)) == NULL)
   1169 		return (EBADF);
   1170 
   1171 	FILE_USE(fp);
   1172 
   1173 	if (fp->f_type != DTYPE_SOCKET) {
   1174 		FILE_UNUSE(fp, NULL);
   1175 		return (ENOTSOCK);
   1176 	}
   1177 	*fpp = fp;
   1178 	return (0);
   1179 }
   1180