freebsd-src/sys/kern/sys_generic.c
1995-05-30 08:16:23 +00:00

723 lines
16 KiB
C

/*
* 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
* $Id: sys_generic.c,v 1.12 1995/04/13 18:24:33 davidg Exp $
*/
#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/stat.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.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 <vm/vm.h>
#include <i386/ibcs2/ibcs2.h>
int selscan __P((struct proc *, fd_set *, fd_set *, int, int *));
/*
* Read system call.
*/
struct read_args {
int fd;
char *buf;
u_int nbyte;
};
/* ARGSUSED */
int
read(p, uap, retval)
struct proc *p;
register struct read_args *uap;
int *retval;
{
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)uap->fd) >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[uap->fd]) == NULL ||
(fp->f_flag & FREAD) == 0)
return (EBADF);
aiov.iov_base = (caddr_t)uap->buf;
aiov.iov_len = uap->nbyte;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_resid = uap->nbyte;
if (auio.uio_resid < 0)
return (EINVAL);
auio.uio_rw = UIO_READ;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_procp = p;
#ifdef KTRACE
/*
* if tracing, save a copy of iovec
*/
if (KTRPOINT(p, KTR_GENIO))
ktriov = aiov;
#endif
cnt = uap->nbyte;
if ((error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred)))
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, uap->fd, UIO_READ, &ktriov, cnt, error);
#endif
*retval = cnt;
return (error);
}
/*
* Scatter read system call.
*/
struct readv_args {
int fdes;
struct iovec *iovp;
u_int iovcnt;
};
int
readv(p, uap, retval)
struct proc *p;
register struct readv_args *uap;
int *retval;
{
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)uap->fdes) >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[uap->fdes]) == NULL ||
(fp->f_flag & FREAD) == 0)
return (EBADF);
/* note: can't use iovlen until iovcnt is validated */
iovlen = uap->iovcnt * sizeof (struct iovec);
if (uap->iovcnt > UIO_SMALLIOV) {
if (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 = uap->iovcnt;
auio.uio_rw = UIO_READ;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_procp = p;
if ((error = copyin((caddr_t)uap->iovp, (caddr_t)iov, iovlen)))
goto done;
auio.uio_resid = 0;
for (i = 0; i < uap->iovcnt; i++) {
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;
if ((error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred)))
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, uap->fdes, UIO_READ, ktriov,
cnt, error);
FREE(ktriov, M_TEMP);
}
#endif
*retval = cnt;
done:
if (needfree)
FREE(needfree, M_IOV);
return (error);
}
/*
* Write system call
*/
struct write_args {
int fd;
char *buf;
u_int nbyte;
};
int
write(p, uap, retval)
struct proc *p;
register struct write_args *uap;
int *retval;
{
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)uap->fd) >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[uap->fd]) == NULL ||
(fp->f_flag & FWRITE) == 0)
return (EBADF);
aiov.iov_base = (caddr_t)uap->buf;
aiov.iov_len = uap->nbyte;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_resid = uap->nbyte;
auio.uio_rw = UIO_WRITE;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_procp = p;
#ifdef KTRACE
/*
* if tracing, save a copy of iovec
*/
if (KTRPOINT(p, KTR_GENIO))
ktriov = aiov;
#endif
cnt = uap->nbyte;
if ((error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred))) {
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, uap->fd, UIO_WRITE,
&ktriov, cnt, error);
#endif
*retval = cnt;
return (error);
}
/*
* Gather write system call
*/
struct writev_args {
int fd;
struct iovec *iovp;
u_int iovcnt;
};
int
writev(p, uap, retval)
struct proc *p;
register struct writev_args *uap;
int *retval;
{
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)uap->fd) >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[uap->fd]) == NULL ||
(fp->f_flag & FWRITE) == 0)
return (EBADF);
/* note: can't use iovlen until iovcnt is validated */
iovlen = uap->iovcnt * sizeof (struct iovec);
if (uap->iovcnt > UIO_SMALLIOV) {
if (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 = uap->iovcnt;
auio.uio_rw = UIO_WRITE;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_procp = p;
if ((error = copyin((caddr_t)uap->iovp, (caddr_t)iov, iovlen)))
goto done;
auio.uio_resid = 0;
for (i = 0; i < uap->iovcnt; i++) {
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;
if ((error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred))) {
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, 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
*/
struct ioctl_args {
int fd;
int com;
caddr_t data;
};
/* ARGSUSED */
int
ioctl(p, uap, retval)
struct proc *p;
register struct ioctl_args *uap;
int *retval;
{
register struct file *fp;
register struct filedesc *fdp;
register int com, 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)uap->fd >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[uap->fd]) == NULL)
return (EBADF);
if ((fp->f_flag & (FREAD | FWRITE)) == 0)
return (EBADF);
switch (com = uap->com) {
case FIONCLEX:
fdp->fd_ofileflags[uap->fd] &= ~UF_EXCLOSE;
return (0);
case FIOCLEX:
fdp->fd_ofileflags[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;
#ifdef COMPAT_IBCS2
if (size + IBCS2_RETVAL_SIZE > sizeof (stkbuf)) {
memp = (caddr_t)malloc((u_long)size + IBCS2_RETVAL_SIZE,
M_IOCTLOPS, M_WAITOK);
data = memp + IBCS2_RETVAL_SIZE;
} else
data = stkbuf + IBCS2_RETVAL_SIZE;
*(int *)(data - IBCS2_RETVAL_SIZE) = IBCS2_MAGIC_IN;
*(int *)(data - (IBCS2_RETVAL_SIZE - sizeof(int))) = 0;
*(int *)(data - (IBCS2_RETVAL_SIZE - 2*sizeof(int))) = 0;
#else
if (size > sizeof (stkbuf)) {
memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
data = memp;
} else
data = stkbuf;
#endif
if (com&IOC_IN) {
if (size) {
error = copyin(uap->data, data, (u_int)size);
if (error) {
if (memp)
free(memp, M_IOCTLOPS);
return (error);
}
} else
*(caddr_t *)data = 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 = uap->data;
#ifdef COMPAT_IBCS2
else if (com)
/*
* Pick up such things as NIOCxx.
* Any copyouts will have to be done prior
* to return by their servicing code.
*/
*(caddr_t *)data = uap->data;
#endif
switch (com) {
case FIONBIO:
if ((tmp = *(int *)data))
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))
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, (int)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, (int)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, uap->data, (u_int)size);
break;
}
#ifdef COMPAT_IBCS2
if ((*(int *)(data - IBCS2_RETVAL_SIZE)) == IBCS2_MAGIC_OUT) {
retval[0] = *(int *)(data-(IBCS2_RETVAL_SIZE - sizeof(int)));
retval[1] = *(int *)(data-(IBCS2_RETVAL_SIZE - 2*sizeof(int)));
}
#endif
if (memp)
free(memp, M_IOCTLOPS);
return (error);
}
int selwait, nselcoll;
/*
* Select system call.
*/
struct select_args {
u_int nd;
fd_set *in, *ou, *ex;
struct timeval *tv;
};
int
select(p, uap, retval)
register struct proc *p;
register struct select_args *uap;
int *retval;
{
fd_set ibits[3], obits[3];
struct timeval atv;
int s, ncoll, error = 0, timo;
u_int ni;
bzero((caddr_t)ibits, sizeof(ibits));
bzero((caddr_t)obits, sizeof(obits));
if (uap->nd > FD_SETSIZE)
return (EINVAL);
if (uap->nd > p->p_fd->fd_nfiles)
uap->nd = p->p_fd->fd_nfiles; /* forgiving; slightly wrong */
ni = howmany(uap->nd, NFDBITS) * sizeof(fd_mask);
#define getbits(name, x) \
if (uap->name && \
(error = copyin((caddr_t)uap->name, (caddr_t)&ibits[x], ni))) \
goto done;
getbits(in, 0);
getbits(ou, 1);
getbits(ex, 2);
#undef getbits
if (uap->tv) {
error = copyin((caddr_t)uap->tv, (caddr_t)&atv,
sizeof (atv));
if (error)
goto done;
if (itimerfix(&atv)) {
error = EINVAL;
goto done;
}
s = splclock();
timevaladd(&atv, (struct timeval *)&time);
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, ibits, obits, uap->nd, retval);
if (error || *retval)
goto done;
s = splhigh();
/* this should be timercmp(&time, &atv, >=) */
if (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 (uap->name && \
(error2 = copyout((caddr_t)&obits[x], (caddr_t)uap->name, ni))) \
error = error2;
if (error == 0) {
int error2;
putbits(in, 0);
putbits(ou, 1);
putbits(ex, 2);
#undef putbits
}
return (error);
}
int
selscan(p, ibits, obits, nfd, retval)
struct proc *p;
fd_set *ibits, *obits;
int nfd, *retval;
{
register struct filedesc *fdp = p->p_fd;
register int msk, i, j, fd;
register fd_mask bits;
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) {
bits = ibits[msk].fds_bits[i/NFDBITS];
while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
bits &= ~(1 << j);
fp = fdp->fd_ofiles[fd];
if (fp == NULL)
return (EBADF);
if ((*fp->f_ops->fo_select)(fp, flag[msk], p)) {
FD_SET(fd, &obits[msk]);
n++;
}
}
}
}
*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);
}
}