NetBSD/sys/kern/sys_generic.c
cgd f41d0a3d9b in select(), if it's a small number of file descriptors use a
automatic array rather than an array allocated with alloca().
(This was the only use of alloca() in the kernel, and it wasn't
necessary or consistent with the way other functions in this file
work.)
1996-06-13 05:08:47 +00:00

733 lines
17 KiB
C

/* $NetBSD: sys_generic.c,v 1.26 1996/06/13 05:08:47 cgd Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)sys_generic.c 8.5 (Berkeley) 1/21/94
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/socketvar.h>
#include <sys/signalvar.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <sys/mount.h>
#include <sys/syscallargs.h>
int selscan __P((struct proc *, fd_mask *, fd_mask *, int, register_t *));
int seltrue __P((dev_t, int, struct proc *));
/*
* Read system call.
*/
/* ARGSUSED */
int
sys_read(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
register struct sys_read_args /* {
syscallarg(int) fd;
syscallarg(char *) buf;
syscallarg(u_int) nbyte;
} */ *uap = v;
register struct file *fp;
register struct filedesc *fdp = p->p_fd;
struct uio auio;
struct iovec aiov;
long cnt, error = 0;
#ifdef KTRACE
struct iovec ktriov;
#endif
if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL ||
(fp->f_flag & FREAD) == 0)
return (EBADF);
aiov.iov_base = (caddr_t)SCARG(uap, buf);
aiov.iov_len = SCARG(uap, nbyte);
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_resid = SCARG(uap, nbyte);
auio.uio_rw = UIO_READ;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_procp = p;
if (auio.uio_resid < 0)
return EINVAL;
#ifdef KTRACE
/*
* if tracing, save a copy of iovec
*/
if (KTRPOINT(p, KTR_GENIO))
ktriov = aiov;
#endif
cnt = SCARG(uap, nbyte);
error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred);
if (error)
if (auio.uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
cnt -= auio.uio_resid;
#ifdef KTRACE
if (KTRPOINT(p, KTR_GENIO) && error == 0)
ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_READ, &ktriov,
cnt, error);
#endif
*retval = cnt;
return (error);
}
/*
* Scatter read system call.
*/
int
sys_readv(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
register struct sys_readv_args /* {
syscallarg(int) fd;
syscallarg(struct iovec *) iovp;
syscallarg(u_int) iovcnt;
} */ *uap = v;
register struct file *fp;
register struct filedesc *fdp = p->p_fd;
struct uio auio;
register struct iovec *iov;
struct iovec *needfree;
struct iovec aiov[UIO_SMALLIOV];
long i, cnt, error = 0;
u_int iovlen;
#ifdef KTRACE
struct iovec *ktriov = NULL;
#endif
if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL ||
(fp->f_flag & FREAD) == 0)
return (EBADF);
/* note: can't use iovlen until iovcnt is validated */
iovlen = SCARG(uap, iovcnt) * sizeof (struct iovec);
if (SCARG(uap, iovcnt) > UIO_SMALLIOV) {
if (SCARG(uap, iovcnt) > UIO_MAXIOV)
return (EINVAL);
MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK);
needfree = iov;
} else {
iov = aiov;
needfree = NULL;
}
auio.uio_iov = iov;
auio.uio_iovcnt = SCARG(uap, iovcnt);
auio.uio_rw = UIO_READ;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_procp = p;
error = copyin((caddr_t)SCARG(uap, iovp), (caddr_t)iov, iovlen);
if (error)
goto done;
auio.uio_resid = 0;
for (i = 0; i < SCARG(uap, iovcnt); i++) {
#if 0
/* Cannot happen iov_len is unsigned */
if (iov->iov_len < 0) {
error = EINVAL;
goto done;
}
#endif
auio.uio_resid += iov->iov_len;
if (auio.uio_resid < 0) {
error = EINVAL;
goto done;
}
iov++;
}
#ifdef KTRACE
/*
* if tracing, save a copy of iovec
*/
if (KTRPOINT(p, KTR_GENIO)) {
MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen);
}
#endif
cnt = auio.uio_resid;
error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred);
if (error)
if (auio.uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
cnt -= auio.uio_resid;
#ifdef KTRACE
if (ktriov != NULL) {
if (error == 0)
ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_READ, ktriov,
cnt, error);
FREE(ktriov, M_TEMP);
}
#endif
*retval = cnt;
done:
if (needfree)
FREE(needfree, M_IOV);
return (error);
}
/*
* Write system call
*/
int
sys_write(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
register struct sys_write_args /* {
syscallarg(int) fd;
syscallarg(char *) buf;
syscallarg(u_int) nbyte;
} */ *uap = v;
register struct file *fp;
register struct filedesc *fdp = p->p_fd;
struct uio auio;
struct iovec aiov;
long cnt, error = 0;
#ifdef KTRACE
struct iovec ktriov;
#endif
if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL ||
(fp->f_flag & FWRITE) == 0)
return (EBADF);
aiov.iov_base = (caddr_t)SCARG(uap, buf);
aiov.iov_len = SCARG(uap, nbyte);
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_resid = SCARG(uap, nbyte);
auio.uio_rw = UIO_WRITE;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_procp = p;
if (auio.uio_resid < 0)
return EINVAL;
#ifdef KTRACE
/*
* if tracing, save a copy of iovec
*/
if (KTRPOINT(p, KTR_GENIO))
ktriov = aiov;
#endif
cnt = SCARG(uap, nbyte);
error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred);
if (error) {
if (auio.uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
if (error == EPIPE)
psignal(p, SIGPIPE);
}
cnt -= auio.uio_resid;
#ifdef KTRACE
if (KTRPOINT(p, KTR_GENIO) && error == 0)
ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_WRITE,
&ktriov, cnt, error);
#endif
*retval = cnt;
return (error);
}
/*
* Gather write system call
*/
int
sys_writev(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
register struct sys_writev_args /* {
syscallarg(int) fd;
syscallarg(struct iovec *) iovp;
syscallarg(u_int) iovcnt;
} */ *uap = v;
register struct file *fp;
register struct filedesc *fdp = p->p_fd;
struct uio auio;
register struct iovec *iov;
struct iovec *needfree;
struct iovec aiov[UIO_SMALLIOV];
long i, cnt, error = 0;
u_int iovlen;
#ifdef KTRACE
struct iovec *ktriov = NULL;
#endif
if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL ||
(fp->f_flag & FWRITE) == 0)
return (EBADF);
/* note: can't use iovlen until iovcnt is validated */
iovlen = SCARG(uap, iovcnt) * sizeof (struct iovec);
if (SCARG(uap, iovcnt) > UIO_SMALLIOV) {
if (SCARG(uap, iovcnt) > UIO_MAXIOV)
return (EINVAL);
MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK);
needfree = iov;
} else {
iov = aiov;
needfree = NULL;
}
auio.uio_iov = iov;
auio.uio_iovcnt = SCARG(uap, iovcnt);
auio.uio_rw = UIO_WRITE;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_procp = p;
error = copyin((caddr_t)SCARG(uap, iovp), (caddr_t)iov, iovlen);
if (error)
goto done;
auio.uio_resid = 0;
for (i = 0; i < SCARG(uap, iovcnt); i++) {
#if 0
/* Cannot happen iov_len is unsigned */
if (iov->iov_len < 0) {
error = EINVAL;
goto done;
}
#endif
auio.uio_resid += iov->iov_len;
if (auio.uio_resid < 0) {
error = EINVAL;
goto done;
}
iov++;
}
#ifdef KTRACE
/*
* if tracing, save a copy of iovec
*/
if (KTRPOINT(p, KTR_GENIO)) {
MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen);
}
#endif
cnt = auio.uio_resid;
error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred);
if (error) {
if (auio.uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
if (error == EPIPE)
psignal(p, SIGPIPE);
}
cnt -= auio.uio_resid;
#ifdef KTRACE
if (ktriov != NULL) {
if (error == 0)
ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_WRITE,
ktriov, cnt, error);
FREE(ktriov, M_TEMP);
}
#endif
*retval = cnt;
done:
if (needfree)
FREE(needfree, M_IOV);
return (error);
}
/*
* Ioctl system call
*/
/* ARGSUSED */
int
sys_ioctl(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
register struct sys_ioctl_args /* {
syscallarg(int) fd;
syscallarg(u_long) com;
syscallarg(caddr_t) data;
} */ *uap = v;
register struct file *fp;
register struct filedesc *fdp;
register u_long com;
register int error;
register u_int size;
caddr_t data, memp;
int tmp;
#define STK_PARAMS 128
char stkbuf[STK_PARAMS];
fdp = p->p_fd;
if ((u_int)SCARG(uap, fd) >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL)
return (EBADF);
if ((fp->f_flag & (FREAD | FWRITE)) == 0)
return (EBADF);
switch (com = SCARG(uap, com)) {
case FIONCLEX:
fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE;
return (0);
case FIOCLEX:
fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE;
return (0);
}
/*
* Interpret high order word to find amount of data to be
* copied to/from the user's address space.
*/
size = IOCPARM_LEN(com);
if (size > IOCPARM_MAX)
return (ENOTTY);
memp = NULL;
if (size > sizeof (stkbuf)) {
memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
data = memp;
} else
data = stkbuf;
if (com&IOC_IN) {
if (size) {
error = copyin(SCARG(uap, data), data, (u_int)size);
if (error) {
if (memp)
free(memp, M_IOCTLOPS);
return (error);
}
} else
*(caddr_t *)data = SCARG(uap, data);
} else if ((com&IOC_OUT) && size)
/*
* Zero the buffer so the user always
* gets back something deterministic.
*/
bzero(data, size);
else if (com&IOC_VOID)
*(caddr_t *)data = SCARG(uap, data);
switch (com) {
case FIONBIO:
if ((tmp = *(int *)data) != 0)
fp->f_flag |= FNONBLOCK;
else
fp->f_flag &= ~FNONBLOCK;
error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p);
break;
case FIOASYNC:
if ((tmp = *(int *)data) != 0)
fp->f_flag |= FASYNC;
else
fp->f_flag &= ~FASYNC;
error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p);
break;
case FIOSETOWN:
tmp = *(int *)data;
if (fp->f_type == DTYPE_SOCKET) {
((struct socket *)fp->f_data)->so_pgid = tmp;
error = 0;
break;
}
if (tmp <= 0) {
tmp = -tmp;
} else {
struct proc *p1 = pfind(tmp);
if (p1 == 0) {
error = ESRCH;
break;
}
tmp = p1->p_pgrp->pg_id;
}
error = (*fp->f_ops->fo_ioctl)
(fp, TIOCSPGRP, (caddr_t)&tmp, p);
break;
case FIOGETOWN:
if (fp->f_type == DTYPE_SOCKET) {
error = 0;
*(int *)data = ((struct socket *)fp->f_data)->so_pgid;
break;
}
error = (*fp->f_ops->fo_ioctl)(fp, TIOCGPGRP, data, p);
*(int *)data = -*(int *)data;
break;
default:
error = (*fp->f_ops->fo_ioctl)(fp, com, data, p);
/*
* Copy any data to user, size was
* already set and checked above.
*/
if (error == 0 && (com&IOC_OUT) && size)
error = copyout(data, SCARG(uap, data), (u_int)size);
break;
}
if (memp)
free(memp, M_IOCTLOPS);
return (error);
}
int selwait, nselcoll;
/*
* Select system call.
*/
int
sys_select(p, v, retval)
register struct proc *p;
void *v;
register_t *retval;
{
register struct sys_select_args /* {
syscallarg(u_int) nd;
syscallarg(fd_set *) in;
syscallarg(fd_set *) ou;
syscallarg(fd_set *) ex;
syscallarg(struct timeval *) tv;
} */ *uap = v;
caddr_t bits;
char smallbits[howmany(FD_SETSIZE, NFDBITS) * sizeof(fd_mask) * 6];
struct timeval atv;
int s, ncoll, error = 0, timo;
u_int ni;
if (SCARG(uap, nd) > p->p_fd->fd_nfiles) {
/* forgiving; slightly wrong */
SCARG(uap, nd) = p->p_fd->fd_nfiles;
}
ni = howmany(SCARG(uap, nd), NFDBITS) * sizeof(fd_mask);
if (SCARG(uap, nd) > FD_SETSIZE)
bits = malloc(ni * 6, M_TEMP, M_WAITOK);
else
bits = smallbits;
#define getbits(name, x) \
if (SCARG(uap, name)) { \
error = copyin((caddr_t)SCARG(uap, name), bits + ni * x, ni); \
if (error) \
goto done; \
} else \
bzero(bits + ni * x, ni);
getbits(in, 0);
getbits(ou, 1);
getbits(ex, 2);
#undef getbits
if (SCARG(uap, tv)) {
error = copyin((caddr_t)SCARG(uap, tv), (caddr_t)&atv,
sizeof (atv));
if (error)
goto done;
if (itimerfix(&atv)) {
error = EINVAL;
goto done;
}
s = splclock();
timeradd(&atv, &time, &atv);
timo = hzto(&atv);
/*
* Avoid inadvertently sleeping forever.
*/
if (timo == 0)
timo = 1;
splx(s);
} else
timo = 0;
retry:
ncoll = nselcoll;
p->p_flag |= P_SELECT;
error = selscan(p, (fd_mask *)(bits + ni * 0),
(fd_mask *)(bits + ni * 3), SCARG(uap, nd), retval);
if (error || *retval)
goto done;
s = splhigh();
/* this should be timercmp(&time, &atv, >=) */
if (SCARG(uap, tv) && (time.tv_sec > atv.tv_sec ||
(time.tv_sec == atv.tv_sec && time.tv_usec >= atv.tv_usec))) {
splx(s);
goto done;
}
if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) {
splx(s);
goto retry;
}
p->p_flag &= ~P_SELECT;
error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo);
splx(s);
if (error == 0)
goto retry;
done:
p->p_flag &= ~P_SELECT;
/* select is not restarted after signals... */
if (error == ERESTART)
error = EINTR;
if (error == EWOULDBLOCK)
error = 0;
#define putbits(name, x) \
if (SCARG(uap, name) && (error2 = copyout(bits + ni * x, \
(caddr_t)SCARG(uap, name), ni))) \
error = error2;
if (error == 0) {
int error2;
putbits(in, 3);
putbits(ou, 4);
putbits(ex, 5);
#undef putbits
}
if (SCARG(uap, nd) > FD_SETSIZE)
free(bits, M_TEMP);
return (error);
}
int
selscan(p, ibitp, obitp, nfd, retval)
struct proc *p;
fd_mask *ibitp, *obitp;
int nfd;
register_t *retval;
{
register struct filedesc *fdp = p->p_fd;
register int msk, i, j, fd;
register fd_mask ibits, obits;
struct file *fp;
int n = 0;
static int flag[3] = { FREAD, FWRITE, 0 };
for (msk = 0; msk < 3; msk++) {
for (i = 0; i < nfd; i += NFDBITS) {
ibits = *ibitp++;
obits = 0;
while ((j = ffs(ibits)) && (fd = i + --j) < nfd) {
ibits &= ~(1 << j);
fp = fdp->fd_ofiles[fd];
if (fp == NULL)
return (EBADF);
if ((*fp->f_ops->fo_select)(fp, flag[msk], p)) {
obits |= (1 << j);
n++;
}
}
*obitp++ = obits;
}
}
*retval = n;
return (0);
}
/*ARGSUSED*/
int
seltrue(dev, flag, p)
dev_t dev;
int flag;
struct proc *p;
{
return (1);
}
/*
* Record a select request.
*/
void
selrecord(selector, sip)
struct proc *selector;
struct selinfo *sip;
{
struct proc *p;
pid_t mypid;
mypid = selector->p_pid;
if (sip->si_pid == mypid)
return;
if (sip->si_pid && (p = pfind(sip->si_pid)) &&
p->p_wchan == (caddr_t)&selwait)
sip->si_flags |= SI_COLL;
else
sip->si_pid = mypid;
}
/*
* Do a wakeup when a selectable event occurs.
*/
void
selwakeup(sip)
register struct selinfo *sip;
{
register struct proc *p;
int s;
if (sip->si_pid == 0)
return;
if (sip->si_flags & SI_COLL) {
nselcoll++;
sip->si_flags &= ~SI_COLL;
wakeup((caddr_t)&selwait);
}
p = pfind(sip->si_pid);
sip->si_pid = 0;
if (p != NULL) {
s = splhigh();
if (p->p_wchan == (caddr_t)&selwait) {
if (p->p_stat == SSLEEP)
setrunnable(p);
else
unsleep(p);
} else if (p->p_flag & P_SELECT)
p->p_flag &= ~P_SELECT;
splx(s);
}
}