NetBSD/sys/kern/sys_descrip.c

734 lines
16 KiB
C

/* $NetBSD: sys_descrip.c,v 1.51 2024/05/20 09:37:34 martin Exp $ */
/*-
* Copyright (c) 2008, 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 1982, 1986, 1989, 1991, 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. 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.
*
* @(#)kern_descrip.c 8.8 (Berkeley) 2/14/95
*/
/*
* System calls on descriptors.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sys_descrip.c,v 1.51 2024/05/20 09:37:34 martin Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <sys/kmem.h>
#include <sys/pool.h>
#include <sys/syslog.h>
#include <sys/unistd.h>
#include <sys/resourcevar.h>
#include <sys/conf.h>
#include <sys/event.h>
#include <sys/kauth.h>
#include <sys/atomic.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#include <uvm/uvm_readahead.h>
/*
* Duplicate a file descriptor.
*/
int
sys_dup(struct lwp *l, const struct sys_dup_args *uap, register_t *retval)
{
/* {
syscallarg(int) fd;
} */
int error, newfd, oldfd;
file_t *fp;
oldfd = SCARG(uap, fd);
if ((fp = fd_getfile(oldfd)) == NULL) {
return EBADF;
}
error = fd_dup(fp, 0, &newfd, false);
fd_putfile(oldfd);
*retval = newfd;
return error;
}
/*
* Duplicate a file descriptor to a particular value.
*/
int
dodup(struct lwp *l, int from, int to, int flags, register_t *retval)
{
int error;
file_t *fp;
if ((fp = fd_getfile(from)) == NULL)
return EBADF;
mutex_enter(&fp->f_lock);
fp->f_count++;
mutex_exit(&fp->f_lock);
fd_putfile(from);
if ((u_int)to >= curproc->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
(u_int)to >= maxfiles)
error = EBADF;
else if (from == to)
error = 0;
else
error = fd_dup2(fp, to, flags);
closef(fp);
*retval = to;
return error;
}
int
sys___dup3100(struct lwp *l, const struct sys___dup3100_args *uap, register_t *retval)
{
/* {
syscallarg(int) from;
syscallarg(int) to;
syscallarg(int) flags;
} */
if (SCARG(uap, from) == SCARG(uap, to))
return EINVAL;
return dodup(l, SCARG(uap, from), SCARG(uap, to), SCARG(uap, flags),
retval);
}
int
sys_dup2(struct lwp *l, const struct sys_dup2_args *uap, register_t *retval)
{
/* {
syscallarg(int) from;
syscallarg(int) to;
} */
return dodup(l, SCARG(uap, from), SCARG(uap, to), 0, retval);
}
/*
* fcntl call which is being passed to the file's fs.
*/
static int
fcntl_forfs(int fd, file_t *fp, int cmd, void *arg)
{
int error;
u_int size;
void *data, *memp;
#define STK_PARAMS 128
char stkbuf[STK_PARAMS];
if ((fp->f_flag & (FREAD | FWRITE)) == 0)
return (EBADF);
/*
* Interpret high order word to find amount of data to be
* copied to/from the user's address space.
*/
size = (size_t)F_PARAM_LEN(cmd);
if (size > F_PARAM_MAX)
return (EINVAL);
memp = NULL;
if (size > sizeof(stkbuf)) {
memp = kmem_alloc(size, KM_SLEEP);
data = memp;
} else
data = stkbuf;
if (cmd & F_FSIN) {
if (size) {
error = copyin(arg, data, size);
if (error) {
if (memp)
kmem_free(memp, size);
return (error);
}
} else
*(void **)data = arg;
} else if ((cmd & F_FSOUT) != 0 && size != 0) {
/*
* Zero the buffer so the user always
* gets back something deterministic.
*/
memset(data, 0, size);
} else if (cmd & F_FSVOID)
*(void **)data = arg;
error = (*fp->f_ops->fo_fcntl)(fp, cmd, data);
/*
* Copy any data to user, size was
* already set and checked above.
*/
if (error == 0 && (cmd & F_FSOUT) && size)
error = copyout(data, arg, size);
if (memp)
kmem_free(memp, size);
return (error);
}
int
do_fcntl_lock(int fd, int cmd, struct flock *fl)
{
struct file *fp = NULL;
proc_t *p;
int (*fo_advlock)(struct file *, void *, int, struct flock *, int);
int error, flg;
if ((fp = fd_getfile(fd)) == NULL) {
error = EBADF;
goto out;
}
if ((fo_advlock = fp->f_ops->fo_advlock) == NULL) {
error = EINVAL;
goto out;
}
flg = F_POSIX;
p = curproc;
switch (cmd) {
case F_SETLKW:
flg |= F_WAIT;
/* Fall into F_SETLK */
/* FALLTHROUGH */
case F_SETLK:
switch (fl->l_type) {
case F_RDLCK:
if ((fp->f_flag & FREAD) == 0) {
error = EBADF;
break;
}
if ((p->p_flag & PK_ADVLOCK) == 0) {
mutex_enter(p->p_lock);
p->p_flag |= PK_ADVLOCK;
mutex_exit(p->p_lock);
}
error = (*fo_advlock)(fp, p, F_SETLK, fl, flg);
break;
case F_WRLCK:
if ((fp->f_flag & FWRITE) == 0) {
error = EBADF;
break;
}
if ((p->p_flag & PK_ADVLOCK) == 0) {
mutex_enter(p->p_lock);
p->p_flag |= PK_ADVLOCK;
mutex_exit(p->p_lock);
}
error = (*fo_advlock)(fp, p, F_SETLK, fl, flg);
break;
case F_UNLCK:
error = (*fo_advlock)(fp, p, F_UNLCK, fl, F_POSIX);
break;
default:
error = EINVAL;
break;
}
break;
case F_GETLK:
if (fl->l_type != F_RDLCK &&
fl->l_type != F_WRLCK &&
fl->l_type != F_UNLCK) {
error = EINVAL;
break;
}
error = (*fo_advlock)(fp, p, F_GETLK, fl, F_POSIX);
break;
default:
error = EINVAL;
break;
}
out: if (fp)
fd_putfile(fd);
return error;
}
/*
* The file control system call.
*/
int
sys_fcntl(struct lwp *l, const struct sys_fcntl_args *uap, register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(int) cmd;
syscallarg(void *) arg;
} */
int fd, i, tmp, error, cmd, newmin;
filedesc_t *fdp;
fdtab_t *dt;
file_t *fp;
char *kpath;
struct flock fl;
bool cloexec = false;
fd = SCARG(uap, fd);
cmd = SCARG(uap, cmd);
fdp = l->l_fd;
error = 0;
switch (cmd) {
case F_CLOSEM:
if (fd < 0)
return EBADF;
while ((i = fdp->fd_lastfile) >= fd) {
if (fd_getfile(i) == NULL) {
/* Another thread has updated. */
continue;
}
fd_close(i);
}
return 0;
case F_MAXFD:
*retval = fdp->fd_lastfile;
return 0;
case F_SETLKW:
case F_SETLK:
case F_GETLK:
error = copyin(SCARG(uap, arg), &fl, sizeof(fl));
if (error)
return error;
error = do_fcntl_lock(fd, cmd, &fl);
if (cmd == F_GETLK && error == 0)
error = copyout(&fl, SCARG(uap, arg), sizeof(fl));
return error;
default:
/* Handled below */
break;
}
if ((fp = fd_getfile(fd)) == NULL)
return EBADF;
if ((cmd & F_FSCTL)) {
error = fcntl_forfs(fd, fp, cmd, SCARG(uap, arg));
fd_putfile(fd);
return error;
}
switch (cmd) {
case F_DUPFD_CLOEXEC:
cloexec = true;
/*FALLTHROUGH*/
case F_DUPFD:
newmin = (long)SCARG(uap, arg);
if ((u_int)newmin >=
l->l_proc->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
(u_int)newmin >= maxfiles) {
fd_putfile(fd);
return EINVAL;
}
error = fd_dup(fp, newmin, &i, cloexec);
*retval = i;
break;
case F_GETFD:
dt = atomic_load_consume(&fdp->fd_dt);
*retval = dt->dt_ff[fd]->ff_exclose;
break;
case F_SETFD:
fd_set_exclose(l, fd,
((long)SCARG(uap, arg) & FD_CLOEXEC) != 0);
break;
case F_GETNOSIGPIPE:
*retval = (fp->f_flag & FNOSIGPIPE) != 0;
break;
case F_SETNOSIGPIPE:
if (SCARG(uap, arg))
atomic_or_uint(&fp->f_flag, FNOSIGPIPE);
else
atomic_and_uint(&fp->f_flag, ~FNOSIGPIPE);
*retval = 0;
break;
case F_GETFL:
*retval = OFLAGS(fp->f_flag);
break;
case F_SETFL:
/* XXX not guaranteed to be atomic. */
tmp = FFLAGS((long)SCARG(uap, arg)) & FCNTLFLAGS;
error = (*fp->f_ops->fo_fcntl)(fp, F_SETFL, &tmp);
if (error)
break;
i = tmp ^ fp->f_flag;
if (i & FNONBLOCK) {
int flgs = tmp & FNONBLOCK;
error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, &flgs);
if (error) {
(*fp->f_ops->fo_fcntl)(fp, F_SETFL,
&fp->f_flag);
break;
}
}
if (i & FASYNC) {
int flgs = tmp & FASYNC;
error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, &flgs);
if (error) {
if (i & FNONBLOCK) {
tmp = fp->f_flag & FNONBLOCK;
(void)(*fp->f_ops->fo_ioctl)(fp,
FIONBIO, &tmp);
}
(*fp->f_ops->fo_fcntl)(fp, F_SETFL,
&fp->f_flag);
break;
}
}
fp->f_flag = (fp->f_flag & ~FCNTLFLAGS) | tmp;
break;
case F_GETOWN:
error = (*fp->f_ops->fo_ioctl)(fp, FIOGETOWN, &tmp);
*retval = tmp;
break;
case F_SETOWN:
tmp = (int)(uintptr_t) SCARG(uap, arg);
error = (*fp->f_ops->fo_ioctl)(fp, FIOSETOWN, &tmp);
break;
case F_GETPATH:
kpath = PNBUF_GET();
/* vnodes need extra context, so are handled separately */
if (fp->f_type == DTYPE_VNODE)
error = vnode_to_path(kpath, MAXPATHLEN, fp->f_vnode,
l, l->l_proc);
else
error = (*fp->f_ops->fo_fcntl)(fp, F_GETPATH, kpath);
if (error == 0)
error = copyoutstr(kpath, SCARG(uap, arg), MAXPATHLEN,
NULL);
PNBUF_PUT(kpath);
break;
case F_ADD_SEALS:
tmp = (int)(uintptr_t) SCARG(uap, arg);
error = (*fp->f_ops->fo_fcntl)(fp, F_ADD_SEALS, &tmp);
break;
case F_GET_SEALS:
error = (*fp->f_ops->fo_fcntl)(fp, F_GET_SEALS, &tmp);
*retval = tmp;
break;
default:
error = EINVAL;
}
fd_putfile(fd);
return (error);
}
/*
* Close a file descriptor.
*/
int
sys_close(struct lwp *l, const struct sys_close_args *uap, register_t *retval)
{
/* {
syscallarg(int) fd;
} */
int error;
int fd = SCARG(uap, fd);
if (fd_getfile(fd) == NULL) {
return EBADF;
}
error = fd_close(fd);
if (error == ERESTART) {
#ifdef DIAGNOSTIC
printf("%s[%d]: close(%d) returned ERESTART\n",
l->l_proc->p_comm, (int)l->l_proc->p_pid, fd);
#endif
error = EINTR;
}
return error;
}
/*
* Return status information about a file descriptor.
* Common function for compat code.
*/
int
do_sys_fstat(int fd, struct stat *sb)
{
file_t *fp;
int error;
if ((fp = fd_getfile(fd)) == NULL) {
return EBADF;
}
error = (*fp->f_ops->fo_stat)(fp, sb);
fd_putfile(fd);
return error;
}
/*
* Return status information about a file descriptor.
*/
int
sys___fstat50(struct lwp *l, const struct sys___fstat50_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(struct stat *) sb;
} */
struct stat sb;
int error;
error = do_sys_fstat(SCARG(uap, fd), &sb);
if (error == 0) {
error = copyout(&sb, SCARG(uap, sb), sizeof(sb));
}
return error;
}
/*
* Return pathconf information about a file descriptor.
*/
int
sys_fpathconf(struct lwp *l, const struct sys_fpathconf_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(int) name;
} */
int fd, name, error;
file_t *fp;
fd = SCARG(uap, fd);
name = SCARG(uap, name);
error = 0;
if ((fp = fd_getfile(fd)) == NULL)
return EBADF;
if (fp->f_ops->fo_fpathconf == NULL)
error = EOPNOTSUPP;
else
error = (*fp->f_ops->fo_fpathconf)(fp, name, retval);
fd_putfile(fd);
return error;
}
/*
* Apply an advisory lock on a file descriptor.
*
* Just attempt to get a record lock of the requested type on
* the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0).
*/
/* ARGSUSED */
int
sys_flock(struct lwp *l, const struct sys_flock_args *uap, register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(int) how;
} */
int fd, how, error;
struct file *fp = NULL;
int (*fo_advlock)(struct file *, void *, int, struct flock *, int);
struct flock lf;
fd = SCARG(uap, fd);
how = SCARG(uap, how);
if ((fp = fd_getfile(fd)) == NULL) {
error = EBADF;
goto out;
}
if ((fo_advlock = fp->f_ops->fo_advlock) == NULL) {
KASSERT((atomic_load_relaxed(&fp->f_flag) & FHASLOCK) == 0);
error = EOPNOTSUPP;
goto out;
}
lf.l_whence = SEEK_SET;
lf.l_start = 0;
lf.l_len = 0;
switch (how & ~LOCK_NB) {
case LOCK_UN:
lf.l_type = F_UNLCK;
atomic_and_uint(&fp->f_flag, ~FHASLOCK);
error = (*fo_advlock)(fp, fp, F_UNLCK, &lf, F_FLOCK);
goto out;
case LOCK_EX:
lf.l_type = F_WRLCK;
break;
case LOCK_SH:
lf.l_type = F_RDLCK;
break;
default:
error = EINVAL;
goto out;
}
atomic_or_uint(&fp->f_flag, FHASLOCK);
if (how & LOCK_NB) {
error = (*fo_advlock)(fp, fp, F_SETLK, &lf, F_FLOCK);
} else {
error = (*fo_advlock)(fp, fp, F_SETLK, &lf, F_FLOCK|F_WAIT);
}
out: if (fp)
fd_putfile(fd);
return error;
}
int
do_posix_fadvise(int fd, off_t offset, off_t len, int advice)
{
file_t *fp;
int error;
if ((fp = fd_getfile(fd)) == NULL)
return EBADF;
if (fp->f_ops->fo_posix_fadvise == NULL) {
error = EOPNOTSUPP;
} else {
error = (*fp->f_ops->fo_posix_fadvise)(fp, offset, len,
advice);
}
fd_putfile(fd);
return error;
}
int
sys___posix_fadvise50(struct lwp *l,
const struct sys___posix_fadvise50_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(int) pad;
syscallarg(off_t) offset;
syscallarg(off_t) len;
syscallarg(int) advice;
} */
*retval = do_posix_fadvise(SCARG(uap, fd), SCARG(uap, offset),
SCARG(uap, len), SCARG(uap, advice));
return 0;
}
int
sys_pipe(struct lwp *l, const void *v, register_t *retval)
{
int fd[2], error;
if ((error = pipe1(l, fd, 0)) != 0)
return error;
retval[0] = fd[0];
retval[1] = fd[1];
return 0;
}
int
sys_pipe2(struct lwp *l, const struct sys_pipe2_args *uap, register_t *retval)
{
/* {
syscallarg(int[2]) fildes;
syscallarg(int) flags;
} */
int fd[2], error;
if ((error = pipe1(l, fd, SCARG(uap, flags))) != 0)
return error;
if ((error = copyout(fd, SCARG(uap, fildes), sizeof(fd))) != 0)
return error;
retval[0] = 0;
return 0;
}