47934cef8f
the syscall arguments and does the suser() permission check, and kern_mlock(), which does the resource limit checking and calls vm_map_wire(). Split munlock() in a similar way. Enable the RLIMIT_MEMLOCK checking code in kern_mlock(). Replace calls to vslock() and vsunlock() in the sysctl code with calls to kern_mlock() and kern_munlock() so that the sysctl code will obey the wired memory limits. Nuke the vslock() and vsunlock() implementations, which are no longer used. Add a member to struct sysctl_req to track the amount of memory that is wired to handle the request. Modify sysctl_wire_old_buffer() to return an error if its call to kern_mlock() fails. Only wire the minimum of the length specified in the sysctl request and the length specified in its argument list. It is recommended that sysctl handlers that use sysctl_wire_old_buffer() should specify reasonable estimates for the amount of data they want to return so that only the minimum amount of memory is wired no matter what length has been specified by the request. Modify the callers of sysctl_wire_old_buffer() to look for the error return. Modify sysctl_old_user to obey the wired buffer length and clean up its implementation. Reviewed by: bms
2514 lines
56 KiB
C
2514 lines
56 KiB
C
/*
|
|
* 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. 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.
|
|
*
|
|
* @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include "opt_compat.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/limits.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/syscallsubr.h>
|
|
#include <sys/sysproto.h>
|
|
#include <sys/conf.h>
|
|
#include <sys/filedesc.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/limits.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/vnode.h>
|
|
#include <sys/mount.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/namei.h>
|
|
#include <sys/file.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/filio.h>
|
|
#include <sys/fcntl.h>
|
|
#include <sys/unistd.h>
|
|
#include <sys/resourcevar.h>
|
|
#include <sys/event.h>
|
|
#include <sys/sx.h>
|
|
#include <sys/socketvar.h>
|
|
#include <sys/signalvar.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_extern.h>
|
|
#include <vm/uma.h>
|
|
|
|
static MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table");
|
|
static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "file desc to leader",
|
|
"file desc to leader structures");
|
|
static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
|
|
|
|
static uma_zone_t file_zone;
|
|
|
|
static d_open_t fdopen;
|
|
#define NUMFDESC 64
|
|
|
|
#define CDEV_MAJOR 22
|
|
static struct cdevsw fildesc_cdevsw = {
|
|
.d_version = D_VERSION,
|
|
.d_flags = D_NEEDGIANT,
|
|
.d_open = fdopen,
|
|
.d_name = "FD",
|
|
.d_maj = CDEV_MAJOR,
|
|
};
|
|
|
|
/* How to treat 'new' parameter when allocating a fd for do_dup(). */
|
|
enum dup_type { DUP_VARIABLE, DUP_FIXED };
|
|
|
|
static int do_dup(struct thread *td, enum dup_type type, int old, int new,
|
|
register_t *retval);
|
|
static int fd_first_free(struct filedesc *, int, int);
|
|
static int fd_last_used(struct filedesc *, int, int);
|
|
static void fdgrowtable(struct filedesc *, int);
|
|
|
|
/*
|
|
* Descriptor management.
|
|
*/
|
|
struct filelist filehead; /* head of list of open files */
|
|
int nfiles; /* actual number of open files */
|
|
struct sx filelist_lock; /* sx to protect filelist */
|
|
struct mtx sigio_lock; /* mtx to protect pointers to sigio */
|
|
|
|
/*
|
|
* Find the first zero bit in the given bitmap, starting at low and not
|
|
* exceeding size - 1.
|
|
*/
|
|
static int
|
|
fd_first_free(struct filedesc *fdp, int low, int size)
|
|
{
|
|
NDSLOTTYPE *map = fdp->fd_map;
|
|
NDSLOTTYPE mask;
|
|
int off, maxoff;
|
|
|
|
if (low >= size)
|
|
return (low);
|
|
|
|
off = NDSLOT(low);
|
|
if (low % NDENTRIES) {
|
|
mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES)));
|
|
if ((mask &= ~map[off]) != 0UL)
|
|
return (off * NDENTRIES + ffsl(mask) - 1);
|
|
++off;
|
|
}
|
|
for (maxoff = NDSLOTS(size); off < maxoff; ++off)
|
|
if (map[off] != ~0UL)
|
|
return (off * NDENTRIES + ffsl(~map[off]) - 1);
|
|
return (size);
|
|
}
|
|
|
|
/*
|
|
* Find the highest non-zero bit in the given bitmap, starting at low and
|
|
* not exceeding size - 1.
|
|
*/
|
|
static int
|
|
fd_last_used(struct filedesc *fdp, int low, int size)
|
|
{
|
|
NDSLOTTYPE *map = fdp->fd_map;
|
|
NDSLOTTYPE mask;
|
|
int off, minoff;
|
|
|
|
if (low >= size)
|
|
return (-1);
|
|
|
|
off = NDSLOT(size);
|
|
if (size % NDENTRIES) {
|
|
mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES));
|
|
if ((mask &= map[off]) != 0)
|
|
return (off * NDENTRIES + flsl(mask) - 1);
|
|
--off;
|
|
}
|
|
for (minoff = NDSLOT(low); off >= minoff; --off)
|
|
if (map[off] != 0)
|
|
return (off * NDENTRIES + flsl(map[off]) - 1);
|
|
return (size - 1);
|
|
}
|
|
|
|
static int
|
|
fdisused(struct filedesc *fdp, int fd)
|
|
{
|
|
KASSERT(fd >= 0 && fd < fdp->fd_nfiles,
|
|
("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles));
|
|
return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0);
|
|
}
|
|
|
|
/*
|
|
* Mark a file descriptor as used.
|
|
*/
|
|
void
|
|
fdused(struct filedesc *fdp, int fd)
|
|
{
|
|
FILEDESC_LOCK_ASSERT(fdp, MA_OWNED);
|
|
KASSERT(!fdisused(fdp, fd),
|
|
("fd already used"));
|
|
fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd);
|
|
if (fd > fdp->fd_lastfile)
|
|
fdp->fd_lastfile = fd;
|
|
if (fd == fdp->fd_freefile)
|
|
fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles);
|
|
}
|
|
|
|
/*
|
|
* Mark a file descriptor as unused.
|
|
*/
|
|
void
|
|
fdunused(struct filedesc *fdp, int fd)
|
|
{
|
|
FILEDESC_LOCK_ASSERT(fdp, MA_OWNED);
|
|
KASSERT(fdisused(fdp, fd),
|
|
("fd is already unused"));
|
|
KASSERT(fdp->fd_ofiles[fd] == NULL,
|
|
("fd is still in use"));
|
|
fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd);
|
|
if (fd < fdp->fd_freefile)
|
|
fdp->fd_freefile = fd;
|
|
if (fd == fdp->fd_lastfile)
|
|
fdp->fd_lastfile = fd_last_used(fdp, 0, fd);
|
|
}
|
|
|
|
/*
|
|
* System calls on descriptors.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct getdtablesize_args {
|
|
int dummy;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
getdtablesize(td, uap)
|
|
struct thread *td;
|
|
struct getdtablesize_args *uap;
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
|
|
PROC_LOCK(p);
|
|
td->td_retval[0] =
|
|
min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
|
|
PROC_UNLOCK(p);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Duplicate a file descriptor to a particular value.
|
|
*
|
|
* note: keep in mind that a potential race condition exists when closing
|
|
* descriptors from a shared descriptor table (via rfork).
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct dup2_args {
|
|
u_int from;
|
|
u_int to;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
dup2(td, uap)
|
|
struct thread *td;
|
|
struct dup2_args *uap;
|
|
{
|
|
|
|
return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to,
|
|
td->td_retval));
|
|
}
|
|
|
|
/*
|
|
* Duplicate a file descriptor.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct dup_args {
|
|
u_int fd;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
dup(td, uap)
|
|
struct thread *td;
|
|
struct dup_args *uap;
|
|
{
|
|
|
|
return (do_dup(td, DUP_VARIABLE, (int)uap->fd, 0, td->td_retval));
|
|
}
|
|
|
|
/*
|
|
* The file control system call.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct fcntl_args {
|
|
int fd;
|
|
int cmd;
|
|
long arg;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
fcntl(td, uap)
|
|
struct thread *td;
|
|
struct fcntl_args *uap;
|
|
{
|
|
struct flock fl;
|
|
intptr_t arg;
|
|
int error;
|
|
|
|
error = 0;
|
|
switch (uap->cmd) {
|
|
case F_GETLK:
|
|
case F_SETLK:
|
|
case F_SETLKW:
|
|
error = copyin((void *)(intptr_t)uap->arg, &fl, sizeof(fl));
|
|
arg = (intptr_t)&fl;
|
|
break;
|
|
default:
|
|
arg = uap->arg;
|
|
break;
|
|
}
|
|
if (error)
|
|
return (error);
|
|
error = kern_fcntl(td, uap->fd, uap->cmd, arg);
|
|
if (error)
|
|
return (error);
|
|
if (uap->cmd == F_GETLK)
|
|
error = copyout(&fl, (void *)(intptr_t)uap->arg, sizeof(fl));
|
|
return (error);
|
|
}
|
|
|
|
int
|
|
kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
|
|
{
|
|
struct filedesc *fdp;
|
|
struct flock *flp;
|
|
struct file *fp;
|
|
struct proc *p;
|
|
char *pop;
|
|
struct vnode *vp;
|
|
u_int newmin;
|
|
int error, flg, tmp;
|
|
|
|
error = 0;
|
|
flg = F_POSIX;
|
|
p = td->td_proc;
|
|
fdp = p->p_fd;
|
|
mtx_lock(&Giant);
|
|
FILEDESC_LOCK(fdp);
|
|
if ((unsigned)fd >= fdp->fd_nfiles ||
|
|
(fp = fdp->fd_ofiles[fd]) == NULL) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
error = EBADF;
|
|
goto done2;
|
|
}
|
|
pop = &fdp->fd_ofileflags[fd];
|
|
|
|
switch (cmd) {
|
|
case F_DUPFD:
|
|
FILEDESC_UNLOCK(fdp);
|
|
newmin = arg;
|
|
PROC_LOCK(p);
|
|
if (newmin >= lim_cur(p, RLIMIT_NOFILE) ||
|
|
newmin >= maxfilesperproc) {
|
|
PROC_UNLOCK(p);
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
PROC_UNLOCK(p);
|
|
error = do_dup(td, DUP_VARIABLE, fd, newmin, td->td_retval);
|
|
break;
|
|
|
|
case F_GETFD:
|
|
td->td_retval[0] = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0;
|
|
FILEDESC_UNLOCK(fdp);
|
|
break;
|
|
|
|
case F_SETFD:
|
|
*pop = (*pop &~ UF_EXCLOSE) |
|
|
(arg & FD_CLOEXEC ? UF_EXCLOSE : 0);
|
|
FILEDESC_UNLOCK(fdp);
|
|
break;
|
|
|
|
case F_GETFL:
|
|
FILE_LOCK(fp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
td->td_retval[0] = OFLAGS(fp->f_flag);
|
|
FILE_UNLOCK(fp);
|
|
break;
|
|
|
|
case F_SETFL:
|
|
FILE_LOCK(fp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
fhold_locked(fp);
|
|
fp->f_flag &= ~FCNTLFLAGS;
|
|
fp->f_flag |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS;
|
|
FILE_UNLOCK(fp);
|
|
tmp = fp->f_flag & FNONBLOCK;
|
|
error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
|
|
if (error) {
|
|
fdrop(fp, td);
|
|
break;
|
|
}
|
|
tmp = fp->f_flag & FASYNC;
|
|
error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td);
|
|
if (error == 0) {
|
|
fdrop(fp, td);
|
|
break;
|
|
}
|
|
FILE_LOCK(fp);
|
|
fp->f_flag &= ~FNONBLOCK;
|
|
FILE_UNLOCK(fp);
|
|
tmp = 0;
|
|
(void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
|
|
fdrop(fp, td);
|
|
break;
|
|
|
|
case F_GETOWN:
|
|
fhold(fp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td);
|
|
if (error == 0)
|
|
td->td_retval[0] = tmp;
|
|
fdrop(fp, td);
|
|
break;
|
|
|
|
case F_SETOWN:
|
|
fhold(fp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
tmp = arg;
|
|
error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td);
|
|
fdrop(fp, td);
|
|
break;
|
|
|
|
case F_SETLKW:
|
|
flg |= F_WAIT;
|
|
/* FALLTHROUGH F_SETLK */
|
|
|
|
case F_SETLK:
|
|
if (fp->f_type != DTYPE_VNODE) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
error = EBADF;
|
|
break;
|
|
}
|
|
|
|
flp = (struct flock *)arg;
|
|
if (flp->l_whence == SEEK_CUR) {
|
|
if (fp->f_offset < 0 ||
|
|
(flp->l_start > 0 &&
|
|
fp->f_offset > OFF_MAX - flp->l_start)) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
error = EOVERFLOW;
|
|
break;
|
|
}
|
|
flp->l_start += fp->f_offset;
|
|
}
|
|
|
|
/*
|
|
* VOP_ADVLOCK() may block.
|
|
*/
|
|
fhold(fp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
vp = fp->f_vnode;
|
|
|
|
switch (flp->l_type) {
|
|
case F_RDLCK:
|
|
if ((fp->f_flag & FREAD) == 0) {
|
|
error = EBADF;
|
|
break;
|
|
}
|
|
PROC_LOCK(p->p_leader);
|
|
p->p_leader->p_flag |= P_ADVLOCK;
|
|
PROC_UNLOCK(p->p_leader);
|
|
error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
|
|
flp, flg);
|
|
break;
|
|
case F_WRLCK:
|
|
if ((fp->f_flag & FWRITE) == 0) {
|
|
error = EBADF;
|
|
break;
|
|
}
|
|
PROC_LOCK(p->p_leader);
|
|
p->p_leader->p_flag |= P_ADVLOCK;
|
|
PROC_UNLOCK(p->p_leader);
|
|
error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
|
|
flp, flg);
|
|
break;
|
|
case F_UNLCK:
|
|
error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
|
|
flp, F_POSIX);
|
|
break;
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
/* Check for race with close */
|
|
FILEDESC_LOCK(fdp);
|
|
if ((unsigned) fd >= fdp->fd_nfiles ||
|
|
fp != fdp->fd_ofiles[fd]) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
flp->l_whence = SEEK_SET;
|
|
flp->l_start = 0;
|
|
flp->l_len = 0;
|
|
flp->l_type = F_UNLCK;
|
|
(void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
|
|
F_UNLCK, flp, F_POSIX);
|
|
} else
|
|
FILEDESC_UNLOCK(fdp);
|
|
fdrop(fp, td);
|
|
break;
|
|
|
|
case F_GETLK:
|
|
if (fp->f_type != DTYPE_VNODE) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
error = EBADF;
|
|
break;
|
|
}
|
|
flp = (struct flock *)arg;
|
|
if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK &&
|
|
flp->l_type != F_UNLCK) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
if (flp->l_whence == SEEK_CUR) {
|
|
if ((flp->l_start > 0 &&
|
|
fp->f_offset > OFF_MAX - flp->l_start) ||
|
|
(flp->l_start < 0 &&
|
|
fp->f_offset < OFF_MIN - flp->l_start)) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
error = EOVERFLOW;
|
|
break;
|
|
}
|
|
flp->l_start += fp->f_offset;
|
|
}
|
|
/*
|
|
* VOP_ADVLOCK() may block.
|
|
*/
|
|
fhold(fp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
vp = fp->f_vnode;
|
|
error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp,
|
|
F_POSIX);
|
|
fdrop(fp, td);
|
|
break;
|
|
default:
|
|
FILEDESC_UNLOCK(fdp);
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
done2:
|
|
mtx_unlock(&Giant);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Common code for dup, dup2, and fcntl(F_DUPFD).
|
|
*/
|
|
static int
|
|
do_dup(td, type, old, new, retval)
|
|
enum dup_type type;
|
|
int old, new;
|
|
register_t *retval;
|
|
struct thread *td;
|
|
{
|
|
struct filedesc *fdp;
|
|
struct proc *p;
|
|
struct file *fp;
|
|
struct file *delfp;
|
|
int error, holdleaders, maxfd;
|
|
|
|
KASSERT((type == DUP_VARIABLE || type == DUP_FIXED),
|
|
("invalid dup type %d", type));
|
|
|
|
p = td->td_proc;
|
|
fdp = p->p_fd;
|
|
|
|
/*
|
|
* Verify we have a valid descriptor to dup from and possibly to
|
|
* dup to.
|
|
*/
|
|
if (old < 0 || new < 0)
|
|
return (EBADF);
|
|
PROC_LOCK(p);
|
|
maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
|
|
PROC_UNLOCK(p);
|
|
if (new >= maxfd)
|
|
return (EMFILE);
|
|
|
|
FILEDESC_LOCK(fdp);
|
|
if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
return (EBADF);
|
|
}
|
|
if (type == DUP_FIXED && old == new) {
|
|
*retval = new;
|
|
FILEDESC_UNLOCK(fdp);
|
|
return (0);
|
|
}
|
|
fp = fdp->fd_ofiles[old];
|
|
fhold(fp);
|
|
|
|
/*
|
|
* If the caller specified a file descriptor, make sure the file
|
|
* table is large enough to hold it, and grab it. Otherwise, just
|
|
* allocate a new descriptor the usual way. Since the filedesc
|
|
* lock may be temporarily dropped in the process, we have to look
|
|
* out for a race.
|
|
*/
|
|
if (type == DUP_FIXED) {
|
|
if (new >= fdp->fd_nfiles)
|
|
fdgrowtable(fdp, new + 1);
|
|
if (fdp->fd_ofiles[new] == NULL)
|
|
fdused(fdp, new);
|
|
} else {
|
|
if ((error = fdalloc(td, new, &new)) != 0) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
fdrop(fp, td);
|
|
return (error);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If the old file changed out from under us then treat it as a
|
|
* bad file descriptor. Userland should do its own locking to
|
|
* avoid this case.
|
|
*/
|
|
if (fdp->fd_ofiles[old] != fp) {
|
|
/* we've allocated a descriptor which we won't use */
|
|
if (fdp->fd_ofiles[new] == NULL)
|
|
fdunused(fdp, new);
|
|
FILEDESC_UNLOCK(fdp);
|
|
fdrop(fp, td);
|
|
return (EBADF);
|
|
}
|
|
KASSERT(old != new,
|
|
("new fd is same as old"));
|
|
|
|
/*
|
|
* Save info on the descriptor being overwritten. We cannot close
|
|
* it without introducing an ownership race for the slot, since we
|
|
* need to drop the filedesc lock to call closef().
|
|
*
|
|
* XXX this duplicates parts of close().
|
|
*/
|
|
delfp = fdp->fd_ofiles[new];
|
|
holdleaders = 0;
|
|
if (delfp != NULL) {
|
|
if (td->td_proc->p_fdtol != NULL) {
|
|
/*
|
|
* Ask fdfree() to sleep to ensure that all relevant
|
|
* process leaders can be traversed in closef().
|
|
*/
|
|
fdp->fd_holdleaderscount++;
|
|
holdleaders = 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Duplicate the source descriptor
|
|
*/
|
|
fdp->fd_ofiles[new] = fp;
|
|
fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE;
|
|
if (new > fdp->fd_lastfile)
|
|
fdp->fd_lastfile = new;
|
|
FILEDESC_UNLOCK(fdp);
|
|
*retval = new;
|
|
|
|
/*
|
|
* If we dup'd over a valid file, we now own the reference to it
|
|
* and must dispose of it using closef() semantics (as if a
|
|
* close() were performed on it).
|
|
*
|
|
* XXX this duplicates parts of close().
|
|
*/
|
|
if (delfp != NULL) {
|
|
/* XXX need to call knote_fdclose() */
|
|
mtx_lock(&Giant);
|
|
(void) closef(delfp, td);
|
|
mtx_unlock(&Giant);
|
|
if (holdleaders) {
|
|
FILEDESC_LOCK(fdp);
|
|
fdp->fd_holdleaderscount--;
|
|
if (fdp->fd_holdleaderscount == 0 &&
|
|
fdp->fd_holdleaderswakeup != 0) {
|
|
fdp->fd_holdleaderswakeup = 0;
|
|
wakeup(&fdp->fd_holdleaderscount);
|
|
}
|
|
FILEDESC_UNLOCK(fdp);
|
|
}
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* If sigio is on the list associated with a process or process group,
|
|
* disable signalling from the device, remove sigio from the list and
|
|
* free sigio.
|
|
*/
|
|
void
|
|
funsetown(sigiop)
|
|
struct sigio **sigiop;
|
|
{
|
|
struct sigio *sigio;
|
|
|
|
SIGIO_LOCK();
|
|
sigio = *sigiop;
|
|
if (sigio == NULL) {
|
|
SIGIO_UNLOCK();
|
|
return;
|
|
}
|
|
*(sigio->sio_myref) = NULL;
|
|
if ((sigio)->sio_pgid < 0) {
|
|
struct pgrp *pg = (sigio)->sio_pgrp;
|
|
PGRP_LOCK(pg);
|
|
SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio,
|
|
sigio, sio_pgsigio);
|
|
PGRP_UNLOCK(pg);
|
|
} else {
|
|
struct proc *p = (sigio)->sio_proc;
|
|
PROC_LOCK(p);
|
|
SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio,
|
|
sigio, sio_pgsigio);
|
|
PROC_UNLOCK(p);
|
|
}
|
|
SIGIO_UNLOCK();
|
|
crfree(sigio->sio_ucred);
|
|
FREE(sigio, M_SIGIO);
|
|
}
|
|
|
|
/*
|
|
* Free a list of sigio structures.
|
|
* We only need to lock the SIGIO_LOCK because we have made ourselves
|
|
* inaccessable to callers of fsetown and therefore do not need to lock
|
|
* the proc or pgrp struct for the list manipulation.
|
|
*/
|
|
void
|
|
funsetownlst(sigiolst)
|
|
struct sigiolst *sigiolst;
|
|
{
|
|
struct proc *p;
|
|
struct pgrp *pg;
|
|
struct sigio *sigio;
|
|
|
|
sigio = SLIST_FIRST(sigiolst);
|
|
if (sigio == NULL)
|
|
return;
|
|
p = NULL;
|
|
pg = NULL;
|
|
|
|
/*
|
|
* Every entry of the list should belong
|
|
* to a single proc or pgrp.
|
|
*/
|
|
if (sigio->sio_pgid < 0) {
|
|
pg = sigio->sio_pgrp;
|
|
PGRP_LOCK_ASSERT(pg, MA_NOTOWNED);
|
|
} else /* if (sigio->sio_pgid > 0) */ {
|
|
p = sigio->sio_proc;
|
|
PROC_LOCK_ASSERT(p, MA_NOTOWNED);
|
|
}
|
|
|
|
SIGIO_LOCK();
|
|
while ((sigio = SLIST_FIRST(sigiolst)) != NULL) {
|
|
*(sigio->sio_myref) = NULL;
|
|
if (pg != NULL) {
|
|
KASSERT(sigio->sio_pgid < 0,
|
|
("Proc sigio in pgrp sigio list"));
|
|
KASSERT(sigio->sio_pgrp == pg,
|
|
("Bogus pgrp in sigio list"));
|
|
PGRP_LOCK(pg);
|
|
SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio,
|
|
sio_pgsigio);
|
|
PGRP_UNLOCK(pg);
|
|
} else /* if (p != NULL) */ {
|
|
KASSERT(sigio->sio_pgid > 0,
|
|
("Pgrp sigio in proc sigio list"));
|
|
KASSERT(sigio->sio_proc == p,
|
|
("Bogus proc in sigio list"));
|
|
PROC_LOCK(p);
|
|
SLIST_REMOVE(&p->p_sigiolst, sigio, sigio,
|
|
sio_pgsigio);
|
|
PROC_UNLOCK(p);
|
|
}
|
|
SIGIO_UNLOCK();
|
|
crfree(sigio->sio_ucred);
|
|
FREE(sigio, M_SIGIO);
|
|
SIGIO_LOCK();
|
|
}
|
|
SIGIO_UNLOCK();
|
|
}
|
|
|
|
/*
|
|
* This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
|
|
*
|
|
* After permission checking, add a sigio structure to the sigio list for
|
|
* the process or process group.
|
|
*/
|
|
int
|
|
fsetown(pgid, sigiop)
|
|
pid_t pgid;
|
|
struct sigio **sigiop;
|
|
{
|
|
struct proc *proc;
|
|
struct pgrp *pgrp;
|
|
struct sigio *sigio;
|
|
int ret;
|
|
|
|
if (pgid == 0) {
|
|
funsetown(sigiop);
|
|
return (0);
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
/* Allocate and fill in the new sigio out of locks. */
|
|
MALLOC(sigio, struct sigio *, sizeof(struct sigio), M_SIGIO, M_WAITOK);
|
|
sigio->sio_pgid = pgid;
|
|
sigio->sio_ucred = crhold(curthread->td_ucred);
|
|
sigio->sio_myref = sigiop;
|
|
|
|
sx_slock(&proctree_lock);
|
|
if (pgid > 0) {
|
|
proc = pfind(pgid);
|
|
if (proc == NULL) {
|
|
ret = ESRCH;
|
|
goto fail;
|
|
}
|
|
|
|
/*
|
|
* Policy - Don't allow a process to FSETOWN a process
|
|
* in another session.
|
|
*
|
|
* Remove this test to allow maximum flexibility or
|
|
* restrict FSETOWN to the current process or process
|
|
* group for maximum safety.
|
|
*/
|
|
PROC_UNLOCK(proc);
|
|
if (proc->p_session != curthread->td_proc->p_session) {
|
|
ret = EPERM;
|
|
goto fail;
|
|
}
|
|
|
|
pgrp = NULL;
|
|
} else /* if (pgid < 0) */ {
|
|
pgrp = pgfind(-pgid);
|
|
if (pgrp == NULL) {
|
|
ret = ESRCH;
|
|
goto fail;
|
|
}
|
|
PGRP_UNLOCK(pgrp);
|
|
|
|
/*
|
|
* Policy - Don't allow a process to FSETOWN a process
|
|
* in another session.
|
|
*
|
|
* Remove this test to allow maximum flexibility or
|
|
* restrict FSETOWN to the current process or process
|
|
* group for maximum safety.
|
|
*/
|
|
if (pgrp->pg_session != curthread->td_proc->p_session) {
|
|
ret = EPERM;
|
|
goto fail;
|
|
}
|
|
|
|
proc = NULL;
|
|
}
|
|
funsetown(sigiop);
|
|
if (pgid > 0) {
|
|
PROC_LOCK(proc);
|
|
/*
|
|
* Since funsetownlst() is called without the proctree
|
|
* locked, we need to check for P_WEXIT.
|
|
* XXX: is ESRCH correct?
|
|
*/
|
|
if ((proc->p_flag & P_WEXIT) != 0) {
|
|
PROC_UNLOCK(proc);
|
|
ret = ESRCH;
|
|
goto fail;
|
|
}
|
|
SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio);
|
|
sigio->sio_proc = proc;
|
|
PROC_UNLOCK(proc);
|
|
} else {
|
|
PGRP_LOCK(pgrp);
|
|
SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio);
|
|
sigio->sio_pgrp = pgrp;
|
|
PGRP_UNLOCK(pgrp);
|
|
}
|
|
sx_sunlock(&proctree_lock);
|
|
SIGIO_LOCK();
|
|
*sigiop = sigio;
|
|
SIGIO_UNLOCK();
|
|
return (0);
|
|
|
|
fail:
|
|
sx_sunlock(&proctree_lock);
|
|
crfree(sigio->sio_ucred);
|
|
FREE(sigio, M_SIGIO);
|
|
return (ret);
|
|
}
|
|
|
|
/*
|
|
* This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
|
|
*/
|
|
pid_t
|
|
fgetown(sigiop)
|
|
struct sigio **sigiop;
|
|
{
|
|
pid_t pgid;
|
|
|
|
SIGIO_LOCK();
|
|
pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0;
|
|
SIGIO_UNLOCK();
|
|
return (pgid);
|
|
}
|
|
|
|
/*
|
|
* Close a file descriptor.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct close_args {
|
|
int fd;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
close(td, uap)
|
|
struct thread *td;
|
|
struct close_args *uap;
|
|
{
|
|
struct filedesc *fdp;
|
|
struct file *fp;
|
|
int fd, error;
|
|
int holdleaders;
|
|
|
|
fd = uap->fd;
|
|
error = 0;
|
|
holdleaders = 0;
|
|
fdp = td->td_proc->p_fd;
|
|
mtx_lock(&Giant);
|
|
FILEDESC_LOCK(fdp);
|
|
if ((unsigned)fd >= fdp->fd_nfiles ||
|
|
(fp = fdp->fd_ofiles[fd]) == NULL) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
mtx_unlock(&Giant);
|
|
return (EBADF);
|
|
}
|
|
fdp->fd_ofiles[fd] = NULL;
|
|
fdp->fd_ofileflags[fd] = 0;
|
|
fdunused(fdp, fd);
|
|
if (td->td_proc->p_fdtol != NULL) {
|
|
/*
|
|
* Ask fdfree() to sleep to ensure that all relevant
|
|
* process leaders can be traversed in closef().
|
|
*/
|
|
fdp->fd_holdleaderscount++;
|
|
holdleaders = 1;
|
|
}
|
|
|
|
/*
|
|
* we now hold the fp reference that used to be owned by the descriptor
|
|
* array.
|
|
*/
|
|
if (fd < fdp->fd_knlistsize) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
knote_fdclose(td, fd);
|
|
} else
|
|
FILEDESC_UNLOCK(fdp);
|
|
|
|
error = closef(fp, td);
|
|
mtx_unlock(&Giant);
|
|
if (holdleaders) {
|
|
FILEDESC_LOCK(fdp);
|
|
fdp->fd_holdleaderscount--;
|
|
if (fdp->fd_holdleaderscount == 0 &&
|
|
fdp->fd_holdleaderswakeup != 0) {
|
|
fdp->fd_holdleaderswakeup = 0;
|
|
wakeup(&fdp->fd_holdleaderscount);
|
|
}
|
|
FILEDESC_UNLOCK(fdp);
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
|
|
/*
|
|
* Return status information about a file descriptor.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ofstat_args {
|
|
int fd;
|
|
struct ostat *sb;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
ofstat(td, uap)
|
|
struct thread *td;
|
|
struct ofstat_args *uap;
|
|
{
|
|
struct file *fp;
|
|
struct stat ub;
|
|
struct ostat oub;
|
|
int error;
|
|
|
|
if ((error = fget(td, uap->fd, &fp)) != 0)
|
|
goto done2;
|
|
mtx_lock(&Giant);
|
|
error = fo_stat(fp, &ub, td->td_ucred, td);
|
|
mtx_unlock(&Giant);
|
|
if (error == 0) {
|
|
cvtstat(&ub, &oub);
|
|
error = copyout(&oub, uap->sb, sizeof(oub));
|
|
}
|
|
fdrop(fp, td);
|
|
done2:
|
|
return (error);
|
|
}
|
|
#endif /* COMPAT_43 || COMPAT_SUNOS */
|
|
|
|
/*
|
|
* Return status information about a file descriptor.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct fstat_args {
|
|
int fd;
|
|
struct stat *sb;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
fstat(td, uap)
|
|
struct thread *td;
|
|
struct fstat_args *uap;
|
|
{
|
|
struct file *fp;
|
|
struct stat ub;
|
|
int error;
|
|
|
|
if ((error = fget(td, uap->fd, &fp)) != 0)
|
|
goto done2;
|
|
mtx_lock(&Giant);
|
|
error = fo_stat(fp, &ub, td->td_ucred, td);
|
|
mtx_unlock(&Giant);
|
|
if (error == 0)
|
|
error = copyout(&ub, uap->sb, sizeof(ub));
|
|
fdrop(fp, td);
|
|
done2:
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Return status information about a file descriptor.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct nfstat_args {
|
|
int fd;
|
|
struct nstat *sb;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
nfstat(td, uap)
|
|
struct thread *td;
|
|
struct nfstat_args *uap;
|
|
{
|
|
struct file *fp;
|
|
struct stat ub;
|
|
struct nstat nub;
|
|
int error;
|
|
|
|
if ((error = fget(td, uap->fd, &fp)) != 0)
|
|
goto done2;
|
|
mtx_lock(&Giant);
|
|
error = fo_stat(fp, &ub, td->td_ucred, td);
|
|
mtx_unlock(&Giant);
|
|
if (error == 0) {
|
|
cvtnstat(&ub, &nub);
|
|
error = copyout(&nub, uap->sb, sizeof(nub));
|
|
}
|
|
fdrop(fp, td);
|
|
done2:
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Return pathconf information about a file descriptor.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct fpathconf_args {
|
|
int fd;
|
|
int name;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
fpathconf(td, uap)
|
|
struct thread *td;
|
|
struct fpathconf_args *uap;
|
|
{
|
|
struct file *fp;
|
|
struct vnode *vp;
|
|
int error;
|
|
|
|
if ((error = fget(td, uap->fd, &fp)) != 0)
|
|
return (error);
|
|
|
|
/* If asynchronous I/O is available, it works for all descriptors. */
|
|
if (uap->name == _PC_ASYNC_IO) {
|
|
td->td_retval[0] = async_io_version;
|
|
goto out;
|
|
}
|
|
vp = fp->f_vnode;
|
|
if (vp != NULL) {
|
|
mtx_lock(&Giant);
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
error = VOP_PATHCONF(vp, uap->name, td->td_retval);
|
|
VOP_UNLOCK(vp, 0, td);
|
|
mtx_unlock(&Giant);
|
|
} else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) {
|
|
if (uap->name != _PC_PIPE_BUF) {
|
|
error = EINVAL;
|
|
} else {
|
|
td->td_retval[0] = PIPE_BUF;
|
|
error = 0;
|
|
}
|
|
} else {
|
|
error = EOPNOTSUPP;
|
|
}
|
|
out:
|
|
fdrop(fp, td);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Grow the file table to accomodate (at least) nfd descriptors. This may
|
|
* block and drop the filedesc lock, but it will reacquire it before
|
|
* returing.
|
|
*/
|
|
static void
|
|
fdgrowtable(struct filedesc *fdp, int nfd)
|
|
{
|
|
struct file **ntable;
|
|
char *nfileflags;
|
|
int nnfiles, onfiles;
|
|
NDSLOTTYPE *nmap;
|
|
|
|
FILEDESC_LOCK_ASSERT(fdp, MA_OWNED);
|
|
|
|
KASSERT(fdp->fd_nfiles > 0,
|
|
("zero-length file table"));
|
|
|
|
/* compute the size of the new table */
|
|
onfiles = fdp->fd_nfiles;
|
|
nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */
|
|
if (nnfiles <= onfiles)
|
|
/* the table is already large enough */
|
|
return;
|
|
|
|
/* allocate a new table and (if required) new bitmaps */
|
|
FILEDESC_UNLOCK(fdp);
|
|
MALLOC(ntable, struct file **, nnfiles * OFILESIZE,
|
|
M_FILEDESC, M_ZERO | M_WAITOK);
|
|
nfileflags = (char *)&ntable[nnfiles];
|
|
if (NDSLOTS(nnfiles) > NDSLOTS(onfiles))
|
|
MALLOC(nmap, NDSLOTTYPE *, NDSLOTS(nnfiles) * NDSLOTSIZE,
|
|
M_FILEDESC, M_ZERO | M_WAITOK);
|
|
else
|
|
nmap = NULL;
|
|
FILEDESC_LOCK(fdp);
|
|
|
|
/*
|
|
* We now have new tables ready to go. Since we dropped the
|
|
* filedesc lock to call malloc(), watch out for a race.
|
|
*/
|
|
onfiles = fdp->fd_nfiles;
|
|
if (onfiles >= nnfiles) {
|
|
/* we lost the race, but that's OK */
|
|
free(ntable, M_FILEDESC);
|
|
if (nmap != NULL)
|
|
free(nmap, M_FILEDESC);
|
|
return;
|
|
}
|
|
bcopy(fdp->fd_ofiles, ntable, onfiles * sizeof(*ntable));
|
|
bcopy(fdp->fd_ofileflags, nfileflags, onfiles);
|
|
if (onfiles > NDFILE)
|
|
free(fdp->fd_ofiles, M_FILEDESC);
|
|
fdp->fd_ofiles = ntable;
|
|
fdp->fd_ofileflags = nfileflags;
|
|
if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) {
|
|
bcopy(fdp->fd_map, nmap, NDSLOTS(onfiles) * sizeof(*nmap));
|
|
if (NDSLOTS(onfiles) > NDSLOTS(NDFILE))
|
|
free(fdp->fd_map, M_FILEDESC);
|
|
fdp->fd_map = nmap;
|
|
}
|
|
fdp->fd_nfiles = nnfiles;
|
|
}
|
|
|
|
/*
|
|
* Allocate a file descriptor for the process.
|
|
*/
|
|
int
|
|
fdalloc(struct thread *td, int minfd, int *result)
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
struct filedesc *fdp = p->p_fd;
|
|
int fd = -1, maxfd;
|
|
|
|
FILEDESC_LOCK_ASSERT(fdp, MA_OWNED);
|
|
|
|
PROC_LOCK(p);
|
|
maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
|
|
PROC_UNLOCK(p);
|
|
|
|
/*
|
|
* Search the bitmap for a free descriptor. If none is found, try
|
|
* to grow the file table. Keep at it until we either get a file
|
|
* descriptor or run into process or system limits; fdgrowtable()
|
|
* may drop the filedesc lock, so we're in a race.
|
|
*/
|
|
for (;;) {
|
|
fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
|
|
if (fd >= maxfd)
|
|
return (EMFILE);
|
|
if (fd < fdp->fd_nfiles)
|
|
break;
|
|
fdgrowtable(fdp, min(fdp->fd_nfiles * 2, maxfd));
|
|
}
|
|
|
|
/*
|
|
* Perform some sanity checks, then mark the file descriptor as
|
|
* used and return it to the caller.
|
|
*/
|
|
KASSERT(!fdisused(fdp, fd),
|
|
("fd_first_free() returned non-free descriptor"));
|
|
KASSERT(fdp->fd_ofiles[fd] == NULL,
|
|
("free descriptor isn't"));
|
|
fdp->fd_ofileflags[fd] = 0; /* XXX needed? */
|
|
fdused(fdp, fd);
|
|
fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles);
|
|
*result = fd;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Check to see whether n user file descriptors
|
|
* are available to the process p.
|
|
*/
|
|
int
|
|
fdavail(td, n)
|
|
struct thread *td;
|
|
int n;
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
struct filedesc *fdp = td->td_proc->p_fd;
|
|
struct file **fpp;
|
|
int i, lim, last;
|
|
|
|
FILEDESC_LOCK_ASSERT(fdp, MA_OWNED);
|
|
|
|
PROC_LOCK(p);
|
|
lim = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
|
|
PROC_UNLOCK(p);
|
|
if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0)
|
|
return (1);
|
|
last = min(fdp->fd_nfiles, lim);
|
|
fpp = &fdp->fd_ofiles[fdp->fd_freefile];
|
|
for (i = last - fdp->fd_freefile; --i >= 0; fpp++) {
|
|
if (*fpp == NULL && --n <= 0)
|
|
return (1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Create a new open file structure and allocate
|
|
* a file decriptor for the process that refers to it.
|
|
* We add one reference to the file for the descriptor table
|
|
* and one reference for resultfp. This is to prevent us being
|
|
* prempted and the entry in the descriptor table closed after
|
|
* we release the FILEDESC lock.
|
|
*/
|
|
int
|
|
falloc(td, resultfp, resultfd)
|
|
struct thread *td;
|
|
struct file **resultfp;
|
|
int *resultfd;
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
struct file *fp, *fq;
|
|
int error, i;
|
|
int maxuserfiles = maxfiles - (maxfiles / 20);
|
|
static struct timeval lastfail;
|
|
static int curfail;
|
|
|
|
fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO);
|
|
sx_xlock(&filelist_lock);
|
|
if ((nfiles >= maxuserfiles && td->td_ucred->cr_ruid != 0)
|
|
|| nfiles >= maxfiles) {
|
|
if (ppsratecheck(&lastfail, &curfail, 1)) {
|
|
printf("kern.maxfiles limit exceeded by uid %i, please see tuning(7).\n",
|
|
td->td_ucred->cr_ruid);
|
|
}
|
|
sx_xunlock(&filelist_lock);
|
|
uma_zfree(file_zone, fp);
|
|
return (ENFILE);
|
|
}
|
|
nfiles++;
|
|
|
|
/*
|
|
* If the process has file descriptor zero open, add the new file
|
|
* descriptor to the list of open files at that point, otherwise
|
|
* put it at the front of the list of open files.
|
|
*/
|
|
fp->f_mtxp = mtx_pool_alloc(mtxpool_sleep);
|
|
fp->f_count = 1;
|
|
if (resultfp)
|
|
fp->f_count++;
|
|
fp->f_cred = crhold(td->td_ucred);
|
|
fp->f_ops = &badfileops;
|
|
FILEDESC_LOCK(p->p_fd);
|
|
if ((fq = p->p_fd->fd_ofiles[0])) {
|
|
LIST_INSERT_AFTER(fq, fp, f_list);
|
|
} else {
|
|
LIST_INSERT_HEAD(&filehead, fp, f_list);
|
|
}
|
|
sx_xunlock(&filelist_lock);
|
|
if ((error = fdalloc(td, 0, &i))) {
|
|
FILEDESC_UNLOCK(p->p_fd);
|
|
fdrop(fp, td);
|
|
if (resultfp)
|
|
fdrop(fp, td);
|
|
return (error);
|
|
}
|
|
p->p_fd->fd_ofiles[i] = fp;
|
|
FILEDESC_UNLOCK(p->p_fd);
|
|
if (resultfp)
|
|
*resultfp = fp;
|
|
if (resultfd)
|
|
*resultfd = i;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Free a file descriptor.
|
|
*/
|
|
void
|
|
ffree(fp)
|
|
struct file *fp;
|
|
{
|
|
|
|
KASSERT(fp->f_count == 0, ("ffree: fp_fcount not 0!"));
|
|
sx_xlock(&filelist_lock);
|
|
LIST_REMOVE(fp, f_list);
|
|
nfiles--;
|
|
sx_xunlock(&filelist_lock);
|
|
crfree(fp->f_cred);
|
|
uma_zfree(file_zone, fp);
|
|
}
|
|
|
|
/*
|
|
* Build a new filedesc structure from another.
|
|
* Copy the current, root, and jail root vnode references.
|
|
*/
|
|
struct filedesc *
|
|
fdinit(fdp)
|
|
struct filedesc *fdp;
|
|
{
|
|
struct filedesc0 *newfdp;
|
|
|
|
FILEDESC_LOCK_ASSERT(fdp, MA_OWNED);
|
|
|
|
FILEDESC_UNLOCK(fdp);
|
|
MALLOC(newfdp, struct filedesc0 *, sizeof(struct filedesc0),
|
|
M_FILEDESC, M_WAITOK | M_ZERO);
|
|
FILEDESC_LOCK(fdp);
|
|
mtx_init(&newfdp->fd_fd.fd_mtx, FILEDESC_LOCK_DESC, NULL, MTX_DEF);
|
|
newfdp->fd_fd.fd_cdir = fdp->fd_cdir;
|
|
if (newfdp->fd_fd.fd_cdir)
|
|
VREF(newfdp->fd_fd.fd_cdir);
|
|
newfdp->fd_fd.fd_rdir = fdp->fd_rdir;
|
|
if (newfdp->fd_fd.fd_rdir)
|
|
VREF(newfdp->fd_fd.fd_rdir);
|
|
newfdp->fd_fd.fd_jdir = fdp->fd_jdir;
|
|
if (newfdp->fd_fd.fd_jdir)
|
|
VREF(newfdp->fd_fd.fd_jdir);
|
|
|
|
/* Create the file descriptor table. */
|
|
newfdp->fd_fd.fd_refcnt = 1;
|
|
newfdp->fd_fd.fd_cmask = CMASK;
|
|
newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles;
|
|
newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags;
|
|
newfdp->fd_fd.fd_nfiles = NDFILE;
|
|
newfdp->fd_fd.fd_knlistsize = -1;
|
|
newfdp->fd_fd.fd_map = newfdp->fd_dmap;
|
|
return (&newfdp->fd_fd);
|
|
}
|
|
|
|
/*
|
|
* Share a filedesc structure.
|
|
*/
|
|
struct filedesc *
|
|
fdshare(fdp)
|
|
struct filedesc *fdp;
|
|
{
|
|
FILEDESC_LOCK(fdp);
|
|
fdp->fd_refcnt++;
|
|
FILEDESC_UNLOCK(fdp);
|
|
return (fdp);
|
|
}
|
|
|
|
/*
|
|
* Copy a filedesc structure.
|
|
* A NULL pointer in returns a NULL reference, this is to ease callers,
|
|
* not catch errors.
|
|
*/
|
|
struct filedesc *
|
|
fdcopy(fdp)
|
|
struct filedesc *fdp;
|
|
{
|
|
struct filedesc *newfdp;
|
|
int i;
|
|
|
|
/* Certain daemons might not have file descriptors. */
|
|
if (fdp == NULL)
|
|
return (NULL);
|
|
|
|
FILEDESC_LOCK_ASSERT(fdp, MA_OWNED);
|
|
newfdp = fdinit(fdp);
|
|
while (fdp->fd_lastfile >= newfdp->fd_nfiles) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
FILEDESC_LOCK(newfdp);
|
|
fdgrowtable(newfdp, fdp->fd_lastfile + 1);
|
|
FILEDESC_UNLOCK(newfdp);
|
|
FILEDESC_LOCK(fdp);
|
|
}
|
|
/* copy everything except kqueue descriptors */
|
|
newfdp->fd_freefile = -1;
|
|
for (i = 0; i <= fdp->fd_lastfile; ++i) {
|
|
if (fdisused(fdp, i) &&
|
|
fdp->fd_ofiles[i]->f_type != DTYPE_KQUEUE) {
|
|
newfdp->fd_ofiles[i] = fdp->fd_ofiles[i];
|
|
newfdp->fd_ofileflags[i] = fdp->fd_ofileflags[i];
|
|
fhold(newfdp->fd_ofiles[i]);
|
|
newfdp->fd_lastfile = i;
|
|
} else {
|
|
if (newfdp->fd_freefile == -1)
|
|
newfdp->fd_freefile = i;
|
|
}
|
|
}
|
|
FILEDESC_UNLOCK(fdp);
|
|
FILEDESC_LOCK(newfdp);
|
|
for (i = 0; i <= newfdp->fd_lastfile; ++i)
|
|
if (newfdp->fd_ofiles[i] != NULL)
|
|
fdused(newfdp, i);
|
|
FILEDESC_UNLOCK(newfdp);
|
|
FILEDESC_LOCK(fdp);
|
|
if (newfdp->fd_freefile == -1)
|
|
newfdp->fd_freefile = i;
|
|
newfdp->fd_cmask = fdp->fd_cmask;
|
|
return (newfdp);
|
|
}
|
|
|
|
/* A mutex to protect the association between a proc and filedesc. */
|
|
struct mtx fdesc_mtx;
|
|
MTX_SYSINIT(fdesc, &fdesc_mtx, "fdesc", MTX_DEF);
|
|
|
|
/*
|
|
* Release a filedesc structure.
|
|
*/
|
|
void
|
|
fdfree(td)
|
|
struct thread *td;
|
|
{
|
|
struct filedesc *fdp;
|
|
struct file **fpp;
|
|
int i;
|
|
struct filedesc_to_leader *fdtol;
|
|
struct file *fp;
|
|
struct vnode *vp;
|
|
struct flock lf;
|
|
|
|
/* Certain daemons might not have file descriptors. */
|
|
fdp = td->td_proc->p_fd;
|
|
if (fdp == NULL)
|
|
return;
|
|
|
|
/* Check for special need to clear POSIX style locks */
|
|
fdtol = td->td_proc->p_fdtol;
|
|
if (fdtol != NULL) {
|
|
FILEDESC_LOCK(fdp);
|
|
KASSERT(fdtol->fdl_refcount > 0,
|
|
("filedesc_to_refcount botch: fdl_refcount=%d",
|
|
fdtol->fdl_refcount));
|
|
if (fdtol->fdl_refcount == 1 &&
|
|
(td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
|
|
i = 0;
|
|
fpp = fdp->fd_ofiles;
|
|
for (i = 0, fpp = fdp->fd_ofiles;
|
|
i <= fdp->fd_lastfile;
|
|
i++, fpp++) {
|
|
if (*fpp == NULL ||
|
|
(*fpp)->f_type != DTYPE_VNODE)
|
|
continue;
|
|
fp = *fpp;
|
|
fhold(fp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
lf.l_whence = SEEK_SET;
|
|
lf.l_start = 0;
|
|
lf.l_len = 0;
|
|
lf.l_type = F_UNLCK;
|
|
vp = fp->f_vnode;
|
|
(void) VOP_ADVLOCK(vp,
|
|
(caddr_t)td->td_proc->
|
|
p_leader,
|
|
F_UNLCK,
|
|
&lf,
|
|
F_POSIX);
|
|
FILEDESC_LOCK(fdp);
|
|
fdrop(fp, td);
|
|
fpp = fdp->fd_ofiles + i;
|
|
}
|
|
}
|
|
retry:
|
|
if (fdtol->fdl_refcount == 1) {
|
|
if (fdp->fd_holdleaderscount > 0 &&
|
|
(td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
|
|
/*
|
|
* close() or do_dup() has cleared a reference
|
|
* in a shared file descriptor table.
|
|
*/
|
|
fdp->fd_holdleaderswakeup = 1;
|
|
msleep(&fdp->fd_holdleaderscount, &fdp->fd_mtx,
|
|
PLOCK, "fdlhold", 0);
|
|
goto retry;
|
|
}
|
|
if (fdtol->fdl_holdcount > 0) {
|
|
/*
|
|
* Ensure that fdtol->fdl_leader
|
|
* remains valid in closef().
|
|
*/
|
|
fdtol->fdl_wakeup = 1;
|
|
msleep(fdtol, &fdp->fd_mtx,
|
|
PLOCK, "fdlhold", 0);
|
|
goto retry;
|
|
}
|
|
}
|
|
fdtol->fdl_refcount--;
|
|
if (fdtol->fdl_refcount == 0 &&
|
|
fdtol->fdl_holdcount == 0) {
|
|
fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
|
|
fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
|
|
} else
|
|
fdtol = NULL;
|
|
td->td_proc->p_fdtol = NULL;
|
|
FILEDESC_UNLOCK(fdp);
|
|
if (fdtol != NULL)
|
|
FREE(fdtol, M_FILEDESC_TO_LEADER);
|
|
}
|
|
FILEDESC_LOCK(fdp);
|
|
if (--fdp->fd_refcnt > 0) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* We are the last reference to the structure, so we can
|
|
* safely assume it will not change out from under us.
|
|
*/
|
|
FILEDESC_UNLOCK(fdp);
|
|
fpp = fdp->fd_ofiles;
|
|
for (i = fdp->fd_lastfile; i-- >= 0; fpp++) {
|
|
if (*fpp)
|
|
(void) closef(*fpp, td);
|
|
}
|
|
|
|
/* XXX This should happen earlier. */
|
|
mtx_lock(&fdesc_mtx);
|
|
td->td_proc->p_fd = NULL;
|
|
mtx_unlock(&fdesc_mtx);
|
|
|
|
if (fdp->fd_nfiles > NDFILE)
|
|
FREE(fdp->fd_ofiles, M_FILEDESC);
|
|
if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE))
|
|
FREE(fdp->fd_map, M_FILEDESC);
|
|
if (fdp->fd_cdir)
|
|
vrele(fdp->fd_cdir);
|
|
if (fdp->fd_rdir)
|
|
vrele(fdp->fd_rdir);
|
|
if (fdp->fd_jdir)
|
|
vrele(fdp->fd_jdir);
|
|
if (fdp->fd_knlist)
|
|
FREE(fdp->fd_knlist, M_KQUEUE);
|
|
if (fdp->fd_knhash)
|
|
FREE(fdp->fd_knhash, M_KQUEUE);
|
|
mtx_destroy(&fdp->fd_mtx);
|
|
FREE(fdp, M_FILEDESC);
|
|
}
|
|
|
|
/*
|
|
* For setugid programs, we don't want to people to use that setugidness
|
|
* to generate error messages which write to a file which otherwise would
|
|
* otherwise be off-limits to the process. We check for filesystems where
|
|
* the vnode can change out from under us after execve (like [lin]procfs).
|
|
*
|
|
* Since setugidsafety calls this only for fd 0, 1 and 2, this check is
|
|
* sufficient. We also don't for check setugidness since we know we are.
|
|
*/
|
|
static int
|
|
is_unsafe(struct file *fp)
|
|
{
|
|
if (fp->f_type == DTYPE_VNODE) {
|
|
struct vnode *vp = fp->f_vnode;
|
|
|
|
if ((vp->v_vflag & VV_PROCDEP) != 0)
|
|
return (1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Make this setguid thing safe, if at all possible.
|
|
*/
|
|
void
|
|
setugidsafety(td)
|
|
struct thread *td;
|
|
{
|
|
struct filedesc *fdp;
|
|
int i;
|
|
|
|
/* Certain daemons might not have file descriptors. */
|
|
fdp = td->td_proc->p_fd;
|
|
if (fdp == NULL)
|
|
return;
|
|
|
|
/*
|
|
* Note: fdp->fd_ofiles may be reallocated out from under us while
|
|
* we are blocked in a close. Be careful!
|
|
*/
|
|
FILEDESC_LOCK(fdp);
|
|
for (i = 0; i <= fdp->fd_lastfile; i++) {
|
|
if (i > 2)
|
|
break;
|
|
if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) {
|
|
struct file *fp;
|
|
|
|
if (i < fdp->fd_knlistsize) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
knote_fdclose(td, i);
|
|
FILEDESC_LOCK(fdp);
|
|
}
|
|
/*
|
|
* NULL-out descriptor prior to close to avoid
|
|
* a race while close blocks.
|
|
*/
|
|
fp = fdp->fd_ofiles[i];
|
|
fdp->fd_ofiles[i] = NULL;
|
|
fdp->fd_ofileflags[i] = 0;
|
|
fdunused(fdp, i);
|
|
FILEDESC_UNLOCK(fdp);
|
|
(void) closef(fp, td);
|
|
FILEDESC_LOCK(fdp);
|
|
}
|
|
}
|
|
FILEDESC_UNLOCK(fdp);
|
|
}
|
|
|
|
/*
|
|
* Close any files on exec?
|
|
*/
|
|
void
|
|
fdcloseexec(td)
|
|
struct thread *td;
|
|
{
|
|
struct filedesc *fdp;
|
|
int i;
|
|
|
|
/* Certain daemons might not have file descriptors. */
|
|
fdp = td->td_proc->p_fd;
|
|
if (fdp == NULL)
|
|
return;
|
|
|
|
FILEDESC_LOCK(fdp);
|
|
|
|
/*
|
|
* We cannot cache fd_ofiles or fd_ofileflags since operations
|
|
* may block and rip them out from under us.
|
|
*/
|
|
for (i = 0; i <= fdp->fd_lastfile; i++) {
|
|
if (fdp->fd_ofiles[i] != NULL &&
|
|
(fdp->fd_ofileflags[i] & UF_EXCLOSE)) {
|
|
struct file *fp;
|
|
|
|
if (i < fdp->fd_knlistsize) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
knote_fdclose(td, i);
|
|
FILEDESC_LOCK(fdp);
|
|
}
|
|
/*
|
|
* NULL-out descriptor prior to close to avoid
|
|
* a race while close blocks.
|
|
*/
|
|
fp = fdp->fd_ofiles[i];
|
|
fdp->fd_ofiles[i] = NULL;
|
|
fdp->fd_ofileflags[i] = 0;
|
|
fdunused(fdp, i);
|
|
FILEDESC_UNLOCK(fdp);
|
|
(void) closef(fp, td);
|
|
FILEDESC_LOCK(fdp);
|
|
}
|
|
}
|
|
FILEDESC_UNLOCK(fdp);
|
|
}
|
|
|
|
/*
|
|
* It is unsafe for set[ug]id processes to be started with file
|
|
* descriptors 0..2 closed, as these descriptors are given implicit
|
|
* significance in the Standard C library. fdcheckstd() will create a
|
|
* descriptor referencing /dev/null for each of stdin, stdout, and
|
|
* stderr that is not already open.
|
|
*/
|
|
int
|
|
fdcheckstd(td)
|
|
struct thread *td;
|
|
{
|
|
struct nameidata nd;
|
|
struct filedesc *fdp;
|
|
struct file *fp;
|
|
register_t retval;
|
|
int fd, i, error, flags, devnull;
|
|
|
|
fdp = td->td_proc->p_fd;
|
|
if (fdp == NULL)
|
|
return (0);
|
|
KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared"));
|
|
devnull = -1;
|
|
error = 0;
|
|
for (i = 0; i < 3; i++) {
|
|
if (fdp->fd_ofiles[i] != NULL)
|
|
continue;
|
|
if (devnull < 0) {
|
|
error = falloc(td, &fp, &fd);
|
|
if (error != 0)
|
|
break;
|
|
/* Note extra ref on `fp' held for us by falloc(). */
|
|
KASSERT(fd == i, ("oof, we didn't get our fd"));
|
|
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/dev/null",
|
|
td);
|
|
flags = FREAD | FWRITE;
|
|
error = vn_open(&nd, &flags, 0, -1);
|
|
if (error != 0) {
|
|
/*
|
|
* Someone may have closed the entry in the
|
|
* file descriptor table, so check it hasn't
|
|
* changed before dropping the reference count.
|
|
*/
|
|
FILEDESC_LOCK(fdp);
|
|
KASSERT(fdp->fd_ofiles[fd] == fp,
|
|
("table not shared, how did it change?"));
|
|
fdp->fd_ofiles[fd] = NULL;
|
|
fdunused(fdp, fd);
|
|
FILEDESC_UNLOCK(fdp);
|
|
fdrop(fp, td);
|
|
fdrop(fp, td);
|
|
break;
|
|
}
|
|
NDFREE(&nd, NDF_ONLY_PNBUF);
|
|
fp->f_vnode = nd.ni_vp;
|
|
fp->f_data = nd.ni_vp;
|
|
fp->f_flag = flags;
|
|
fp->f_ops = &vnops;
|
|
fp->f_type = DTYPE_VNODE;
|
|
VOP_UNLOCK(nd.ni_vp, 0, td);
|
|
devnull = fd;
|
|
fdrop(fp, td);
|
|
} else {
|
|
error = do_dup(td, DUP_FIXED, devnull, i, &retval);
|
|
if (error != 0)
|
|
break;
|
|
}
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Internal form of close.
|
|
* Decrement reference count on file structure.
|
|
* Note: td may be NULL when closing a file
|
|
* that was being passed in a message.
|
|
*/
|
|
int
|
|
closef(fp, td)
|
|
struct file *fp;
|
|
struct thread *td;
|
|
{
|
|
struct vnode *vp;
|
|
struct flock lf;
|
|
struct filedesc_to_leader *fdtol;
|
|
struct filedesc *fdp;
|
|
|
|
if (fp == NULL)
|
|
return (0);
|
|
/*
|
|
* POSIX record locking dictates that any close releases ALL
|
|
* locks owned by this process. This is handled by setting
|
|
* a flag in the unlock to free ONLY locks obeying POSIX
|
|
* semantics, and not to free BSD-style file locks.
|
|
* If the descriptor was in a message, POSIX-style locks
|
|
* aren't passed with the descriptor.
|
|
*/
|
|
if (td != NULL &&
|
|
fp->f_type == DTYPE_VNODE) {
|
|
if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
|
|
lf.l_whence = SEEK_SET;
|
|
lf.l_start = 0;
|
|
lf.l_len = 0;
|
|
lf.l_type = F_UNLCK;
|
|
vp = fp->f_vnode;
|
|
(void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader,
|
|
F_UNLCK, &lf, F_POSIX);
|
|
}
|
|
fdtol = td->td_proc->p_fdtol;
|
|
if (fdtol != NULL) {
|
|
/*
|
|
* Handle special case where file descriptor table
|
|
* is shared between multiple process leaders.
|
|
*/
|
|
fdp = td->td_proc->p_fd;
|
|
FILEDESC_LOCK(fdp);
|
|
for (fdtol = fdtol->fdl_next;
|
|
fdtol != td->td_proc->p_fdtol;
|
|
fdtol = fdtol->fdl_next) {
|
|
if ((fdtol->fdl_leader->p_flag &
|
|
P_ADVLOCK) == 0)
|
|
continue;
|
|
fdtol->fdl_holdcount++;
|
|
FILEDESC_UNLOCK(fdp);
|
|
lf.l_whence = SEEK_SET;
|
|
lf.l_start = 0;
|
|
lf.l_len = 0;
|
|
lf.l_type = F_UNLCK;
|
|
vp = fp->f_vnode;
|
|
(void) VOP_ADVLOCK(vp,
|
|
(caddr_t)fdtol->fdl_leader,
|
|
F_UNLCK, &lf, F_POSIX);
|
|
FILEDESC_LOCK(fdp);
|
|
fdtol->fdl_holdcount--;
|
|
if (fdtol->fdl_holdcount == 0 &&
|
|
fdtol->fdl_wakeup != 0) {
|
|
fdtol->fdl_wakeup = 0;
|
|
wakeup(fdtol);
|
|
}
|
|
}
|
|
FILEDESC_UNLOCK(fdp);
|
|
}
|
|
}
|
|
return (fdrop(fp, td));
|
|
}
|
|
|
|
/*
|
|
* Drop reference on struct file passed in, may call closef if the
|
|
* reference hits zero.
|
|
*/
|
|
int
|
|
fdrop(fp, td)
|
|
struct file *fp;
|
|
struct thread *td;
|
|
{
|
|
|
|
FILE_LOCK(fp);
|
|
return (fdrop_locked(fp, td));
|
|
}
|
|
|
|
/*
|
|
* Extract the file pointer associated with the specified descriptor for
|
|
* the current user process.
|
|
*
|
|
* If the descriptor doesn't exist, EBADF is returned.
|
|
*
|
|
* If the descriptor exists but doesn't match 'flags' then
|
|
* return EBADF for read attempts and EINVAL for write attempts.
|
|
*
|
|
* If 'hold' is set (non-zero) the file's refcount will be bumped on return.
|
|
* It should be droped with fdrop().
|
|
* If it is not set, then the refcount will not be bumped however the
|
|
* thread's filedesc struct will be returned locked (for fgetsock).
|
|
*
|
|
* If an error occured the non-zero error is returned and *fpp is set to NULL.
|
|
* Otherwise *fpp is set and zero is returned.
|
|
*/
|
|
static __inline int
|
|
_fget(struct thread *td, int fd, struct file **fpp, int flags, int hold)
|
|
{
|
|
struct filedesc *fdp;
|
|
struct file *fp;
|
|
|
|
*fpp = NULL;
|
|
if (td == NULL || (fdp = td->td_proc->p_fd) == NULL)
|
|
return (EBADF);
|
|
FILEDESC_LOCK(fdp);
|
|
if ((fp = fget_locked(fdp, fd)) == NULL || fp->f_ops == &badfileops) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
return (EBADF);
|
|
}
|
|
|
|
/*
|
|
* Note: FREAD failures returns EBADF to maintain backwards
|
|
* compatibility with what routines returned before.
|
|
*
|
|
* Only one flag, or 0, may be specified.
|
|
*/
|
|
if (flags == FREAD && (fp->f_flag & FREAD) == 0) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
return (EBADF);
|
|
}
|
|
if (flags == FWRITE && (fp->f_flag & FWRITE) == 0) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
return (EINVAL);
|
|
}
|
|
if (hold) {
|
|
fhold(fp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
}
|
|
*fpp = fp;
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
fget(struct thread *td, int fd, struct file **fpp)
|
|
{
|
|
|
|
return(_fget(td, fd, fpp, 0, 1));
|
|
}
|
|
|
|
int
|
|
fget_read(struct thread *td, int fd, struct file **fpp)
|
|
{
|
|
|
|
return(_fget(td, fd, fpp, FREAD, 1));
|
|
}
|
|
|
|
int
|
|
fget_write(struct thread *td, int fd, struct file **fpp)
|
|
{
|
|
|
|
return(_fget(td, fd, fpp, FWRITE, 1));
|
|
}
|
|
|
|
/*
|
|
* Like fget() but loads the underlying vnode, or returns an error if
|
|
* the descriptor does not represent a vnode. Note that pipes use vnodes
|
|
* but never have VM objects (so VOP_GETVOBJECT() calls will return an
|
|
* error). The returned vnode will be vref()d.
|
|
*/
|
|
static __inline int
|
|
_fgetvp(struct thread *td, int fd, struct vnode **vpp, int flags)
|
|
{
|
|
struct file *fp;
|
|
int error;
|
|
|
|
*vpp = NULL;
|
|
if ((error = _fget(td, fd, &fp, 0, 0)) != 0)
|
|
return (error);
|
|
if (fp->f_vnode == NULL) {
|
|
error = EINVAL;
|
|
} else {
|
|
*vpp = fp->f_vnode;
|
|
vref(*vpp);
|
|
}
|
|
FILEDESC_UNLOCK(td->td_proc->p_fd);
|
|
return (error);
|
|
}
|
|
|
|
int
|
|
fgetvp(struct thread *td, int fd, struct vnode **vpp)
|
|
{
|
|
|
|
return (_fgetvp(td, fd, vpp, 0));
|
|
}
|
|
|
|
int
|
|
fgetvp_read(struct thread *td, int fd, struct vnode **vpp)
|
|
{
|
|
|
|
return (_fgetvp(td, fd, vpp, FREAD));
|
|
}
|
|
|
|
int
|
|
fgetvp_write(struct thread *td, int fd, struct vnode **vpp)
|
|
{
|
|
|
|
return (_fgetvp(td, fd, vpp, FWRITE));
|
|
}
|
|
|
|
/*
|
|
* Like fget() but loads the underlying socket, or returns an error if
|
|
* the descriptor does not represent a socket.
|
|
*
|
|
* We bump the ref count on the returned socket. XXX Also obtain the SX
|
|
* lock in the future.
|
|
*/
|
|
int
|
|
fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp)
|
|
{
|
|
struct file *fp;
|
|
int error;
|
|
|
|
*spp = NULL;
|
|
if (fflagp != NULL)
|
|
*fflagp = 0;
|
|
if ((error = _fget(td, fd, &fp, 0, 0)) != 0)
|
|
return (error);
|
|
if (fp->f_type != DTYPE_SOCKET) {
|
|
error = ENOTSOCK;
|
|
} else {
|
|
*spp = fp->f_data;
|
|
if (fflagp)
|
|
*fflagp = fp->f_flag;
|
|
soref(*spp);
|
|
}
|
|
FILEDESC_UNLOCK(td->td_proc->p_fd);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Drop the reference count on the the socket and XXX release the SX lock in
|
|
* the future. The last reference closes the socket.
|
|
*/
|
|
void
|
|
fputsock(struct socket *so)
|
|
{
|
|
|
|
sorele(so);
|
|
}
|
|
|
|
/*
|
|
* Drop reference on struct file passed in, may call closef if the
|
|
* reference hits zero.
|
|
* Expects struct file locked, and will unlock it.
|
|
*/
|
|
int
|
|
fdrop_locked(fp, td)
|
|
struct file *fp;
|
|
struct thread *td;
|
|
{
|
|
struct flock lf;
|
|
struct vnode *vp;
|
|
int error;
|
|
|
|
FILE_LOCK_ASSERT(fp, MA_OWNED);
|
|
|
|
if (--fp->f_count > 0) {
|
|
FILE_UNLOCK(fp);
|
|
return (0);
|
|
}
|
|
/* We have the last ref so we can proceed without the file lock. */
|
|
FILE_UNLOCK(fp);
|
|
mtx_lock(&Giant);
|
|
if (fp->f_count < 0)
|
|
panic("fdrop: count < 0");
|
|
if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) {
|
|
lf.l_whence = SEEK_SET;
|
|
lf.l_start = 0;
|
|
lf.l_len = 0;
|
|
lf.l_type = F_UNLCK;
|
|
vp = fp->f_vnode;
|
|
(void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
|
|
}
|
|
if (fp->f_ops != &badfileops)
|
|
error = fo_close(fp, td);
|
|
else
|
|
error = 0;
|
|
ffree(fp);
|
|
mtx_unlock(&Giant);
|
|
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).
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct flock_args {
|
|
int fd;
|
|
int how;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
flock(td, uap)
|
|
struct thread *td;
|
|
struct flock_args *uap;
|
|
{
|
|
struct file *fp;
|
|
struct vnode *vp;
|
|
struct flock lf;
|
|
int error;
|
|
|
|
if ((error = fget(td, uap->fd, &fp)) != 0)
|
|
return (error);
|
|
if (fp->f_type != DTYPE_VNODE) {
|
|
fdrop(fp, td);
|
|
return (EOPNOTSUPP);
|
|
}
|
|
|
|
mtx_lock(&Giant);
|
|
vp = fp->f_vnode;
|
|
lf.l_whence = SEEK_SET;
|
|
lf.l_start = 0;
|
|
lf.l_len = 0;
|
|
if (uap->how & LOCK_UN) {
|
|
lf.l_type = F_UNLCK;
|
|
FILE_LOCK(fp);
|
|
fp->f_flag &= ~FHASLOCK;
|
|
FILE_UNLOCK(fp);
|
|
error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
|
|
goto done2;
|
|
}
|
|
if (uap->how & LOCK_EX)
|
|
lf.l_type = F_WRLCK;
|
|
else if (uap->how & LOCK_SH)
|
|
lf.l_type = F_RDLCK;
|
|
else {
|
|
error = EBADF;
|
|
goto done2;
|
|
}
|
|
FILE_LOCK(fp);
|
|
fp->f_flag |= FHASLOCK;
|
|
FILE_UNLOCK(fp);
|
|
error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
|
|
(uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
|
|
done2:
|
|
fdrop(fp, td);
|
|
mtx_unlock(&Giant);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* File Descriptor pseudo-device driver (/dev/fd/).
|
|
*
|
|
* Opening minor device N dup()s the file (if any) connected to file
|
|
* descriptor N belonging to the calling process. Note that this driver
|
|
* consists of only the ``open()'' routine, because all subsequent
|
|
* references to this file will be direct to the other driver.
|
|
*/
|
|
/* ARGSUSED */
|
|
static int
|
|
fdopen(dev, mode, type, td)
|
|
dev_t dev;
|
|
int mode, type;
|
|
struct thread *td;
|
|
{
|
|
|
|
/*
|
|
* XXX Kludge: set curthread->td_dupfd to contain the value of the
|
|
* the file descriptor being sought for duplication. The error
|
|
* return ensures that the vnode for this device will be released
|
|
* by vn_open. Open will detect this special error and take the
|
|
* actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
|
|
* will simply report the error.
|
|
*/
|
|
td->td_dupfd = dev2unit(dev);
|
|
return (ENODEV);
|
|
}
|
|
|
|
/*
|
|
* Duplicate the specified descriptor to a free descriptor.
|
|
*/
|
|
int
|
|
dupfdopen(td, fdp, indx, dfd, mode, error)
|
|
struct thread *td;
|
|
struct filedesc *fdp;
|
|
int indx, dfd;
|
|
int mode;
|
|
int error;
|
|
{
|
|
struct file *wfp;
|
|
struct file *fp;
|
|
|
|
/*
|
|
* If the to-be-dup'd fd number is greater than the allowed number
|
|
* of file descriptors, or the fd to be dup'd has already been
|
|
* closed, then reject.
|
|
*/
|
|
FILEDESC_LOCK(fdp);
|
|
if (dfd < 0 || dfd >= fdp->fd_nfiles ||
|
|
(wfp = fdp->fd_ofiles[dfd]) == NULL) {
|
|
FILEDESC_UNLOCK(fdp);
|
|
return (EBADF);
|
|
}
|
|
|
|
/*
|
|
* There are two cases of interest here.
|
|
*
|
|
* For ENODEV simply dup (dfd) to file descriptor
|
|
* (indx) and return.
|
|
*
|
|
* For ENXIO steal away the file structure from (dfd) and
|
|
* store it in (indx). (dfd) is effectively closed by
|
|
* this operation.
|
|
*
|
|
* Any other error code is just returned.
|
|
*/
|
|
switch (error) {
|
|
case ENODEV:
|
|
/*
|
|
* Check that the mode the file is being opened for is a
|
|
* subset of the mode of the existing descriptor.
|
|
*/
|
|
FILE_LOCK(wfp);
|
|
if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) {
|
|
FILE_UNLOCK(wfp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
return (EACCES);
|
|
}
|
|
fp = fdp->fd_ofiles[indx];
|
|
fdp->fd_ofiles[indx] = wfp;
|
|
fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
|
|
if (fp == NULL)
|
|
fdused(fdp, indx);
|
|
fhold_locked(wfp);
|
|
FILE_UNLOCK(wfp);
|
|
if (fp != NULL)
|
|
FILE_LOCK(fp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
/*
|
|
* We now own the reference to fp that the ofiles[] array
|
|
* used to own. Release it.
|
|
*/
|
|
if (fp != NULL)
|
|
fdrop_locked(fp, td);
|
|
return (0);
|
|
|
|
case ENXIO:
|
|
/*
|
|
* Steal away the file pointer from dfd and stuff it into indx.
|
|
*/
|
|
fp = fdp->fd_ofiles[indx];
|
|
fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd];
|
|
fdp->fd_ofiles[dfd] = NULL;
|
|
fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
|
|
fdp->fd_ofileflags[dfd] = 0;
|
|
fdunused(fdp, dfd);
|
|
if (fp == NULL)
|
|
fdused(fdp, indx);
|
|
if (fp != NULL)
|
|
FILE_LOCK(fp);
|
|
FILEDESC_UNLOCK(fdp);
|
|
|
|
/*
|
|
* we now own the reference to fp that the ofiles[] array
|
|
* used to own. Release it.
|
|
*/
|
|
if (fp != NULL)
|
|
fdrop_locked(fp, td);
|
|
return (0);
|
|
|
|
default:
|
|
FILEDESC_UNLOCK(fdp);
|
|
return (error);
|
|
}
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
struct filedesc_to_leader *
|
|
filedesc_to_leader_alloc(struct filedesc_to_leader *old,
|
|
struct filedesc *fdp,
|
|
struct proc *leader)
|
|
{
|
|
struct filedesc_to_leader *fdtol;
|
|
|
|
MALLOC(fdtol, struct filedesc_to_leader *,
|
|
sizeof(struct filedesc_to_leader),
|
|
M_FILEDESC_TO_LEADER,
|
|
M_WAITOK);
|
|
fdtol->fdl_refcount = 1;
|
|
fdtol->fdl_holdcount = 0;
|
|
fdtol->fdl_wakeup = 0;
|
|
fdtol->fdl_leader = leader;
|
|
if (old != NULL) {
|
|
FILEDESC_LOCK(fdp);
|
|
fdtol->fdl_next = old->fdl_next;
|
|
fdtol->fdl_prev = old;
|
|
old->fdl_next = fdtol;
|
|
fdtol->fdl_next->fdl_prev = fdtol;
|
|
FILEDESC_UNLOCK(fdp);
|
|
} else {
|
|
fdtol->fdl_next = fdtol;
|
|
fdtol->fdl_prev = fdtol;
|
|
}
|
|
return (fdtol);
|
|
}
|
|
|
|
/*
|
|
* Get file structures.
|
|
*/
|
|
static int
|
|
sysctl_kern_file(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
struct xfile xf;
|
|
struct filedesc *fdp;
|
|
struct file *fp;
|
|
struct proc *p;
|
|
int error, n;
|
|
|
|
/*
|
|
* Note: because the number of file descriptors is calculated
|
|
* in different ways for sizing vs returning the data,
|
|
* there is information leakage from the first loop. However,
|
|
* it is of a similar order of magnitude to the leakage from
|
|
* global system statistics such as kern.openfiles.
|
|
*/
|
|
error = sysctl_wire_old_buffer(req, 0);
|
|
if (error != 0)
|
|
return (error);
|
|
if (req->oldptr == NULL) {
|
|
n = 16; /* A slight overestimate. */
|
|
sx_slock(&filelist_lock);
|
|
LIST_FOREACH(fp, &filehead, f_list) {
|
|
/*
|
|
* We should grab the lock, but this is an
|
|
* estimate, so does it really matter?
|
|
*/
|
|
/* mtx_lock(fp->f_mtxp); */
|
|
n += fp->f_count;
|
|
/* mtx_unlock(f->f_mtxp); */
|
|
}
|
|
sx_sunlock(&filelist_lock);
|
|
return (SYSCTL_OUT(req, 0, n * sizeof(xf)));
|
|
}
|
|
error = 0;
|
|
bzero(&xf, sizeof(xf));
|
|
xf.xf_size = sizeof(xf);
|
|
sx_slock(&allproc_lock);
|
|
LIST_FOREACH(p, &allproc, p_list) {
|
|
PROC_LOCK(p);
|
|
if (p_cansee(req->td, p) != 0) {
|
|
PROC_UNLOCK(p);
|
|
continue;
|
|
}
|
|
xf.xf_pid = p->p_pid;
|
|
xf.xf_uid = p->p_ucred->cr_uid;
|
|
PROC_UNLOCK(p);
|
|
mtx_lock(&fdesc_mtx);
|
|
if ((fdp = p->p_fd) == NULL) {
|
|
mtx_unlock(&fdesc_mtx);
|
|
continue;
|
|
}
|
|
FILEDESC_LOCK(fdp);
|
|
for (n = 0; n < fdp->fd_nfiles; ++n) {
|
|
if ((fp = fdp->fd_ofiles[n]) == NULL)
|
|
continue;
|
|
xf.xf_fd = n;
|
|
xf.xf_file = fp;
|
|
xf.xf_data = fp->f_data;
|
|
xf.xf_type = fp->f_type;
|
|
xf.xf_count = fp->f_count;
|
|
xf.xf_msgcount = fp->f_msgcount;
|
|
xf.xf_offset = fp->f_offset;
|
|
xf.xf_flag = fp->f_flag;
|
|
error = SYSCTL_OUT(req, &xf, sizeof(xf));
|
|
if (error)
|
|
break;
|
|
}
|
|
FILEDESC_UNLOCK(fdp);
|
|
mtx_unlock(&fdesc_mtx);
|
|
if (error)
|
|
break;
|
|
}
|
|
sx_sunlock(&allproc_lock);
|
|
return (error);
|
|
}
|
|
|
|
SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD,
|
|
0, 0, sysctl_kern_file, "S,xfile", "Entire file table");
|
|
|
|
SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
|
|
&maxfilesperproc, 0, "Maximum files allowed open per process");
|
|
|
|
SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
|
|
&maxfiles, 0, "Maximum number of files");
|
|
|
|
SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
|
|
&nfiles, 0, "System-wide number of open files");
|
|
|
|
static void
|
|
fildesc_drvinit(void *unused)
|
|
{
|
|
dev_t dev;
|
|
|
|
dev = make_dev(&fildesc_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, "fd/0");
|
|
make_dev_alias(dev, "stdin");
|
|
dev = make_dev(&fildesc_cdevsw, 1, UID_ROOT, GID_WHEEL, 0666, "fd/1");
|
|
make_dev_alias(dev, "stdout");
|
|
dev = make_dev(&fildesc_cdevsw, 2, UID_ROOT, GID_WHEEL, 0666, "fd/2");
|
|
make_dev_alias(dev, "stderr");
|
|
}
|
|
|
|
static fo_rdwr_t badfo_readwrite;
|
|
static fo_ioctl_t badfo_ioctl;
|
|
static fo_poll_t badfo_poll;
|
|
static fo_kqfilter_t badfo_kqfilter;
|
|
static fo_stat_t badfo_stat;
|
|
static fo_close_t badfo_close;
|
|
|
|
struct fileops badfileops = {
|
|
.fo_read = badfo_readwrite,
|
|
.fo_write = badfo_readwrite,
|
|
.fo_ioctl = badfo_ioctl,
|
|
.fo_poll = badfo_poll,
|
|
.fo_kqfilter = badfo_kqfilter,
|
|
.fo_stat = badfo_stat,
|
|
.fo_close = badfo_close,
|
|
};
|
|
|
|
static int
|
|
badfo_readwrite(fp, uio, active_cred, flags, td)
|
|
struct file *fp;
|
|
struct uio *uio;
|
|
struct ucred *active_cred;
|
|
struct thread *td;
|
|
int flags;
|
|
{
|
|
|
|
return (EBADF);
|
|
}
|
|
|
|
static int
|
|
badfo_ioctl(fp, com, data, active_cred, td)
|
|
struct file *fp;
|
|
u_long com;
|
|
void *data;
|
|
struct ucred *active_cred;
|
|
struct thread *td;
|
|
{
|
|
|
|
return (EBADF);
|
|
}
|
|
|
|
static int
|
|
badfo_poll(fp, events, active_cred, td)
|
|
struct file *fp;
|
|
int events;
|
|
struct ucred *active_cred;
|
|
struct thread *td;
|
|
{
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
badfo_kqfilter(fp, kn)
|
|
struct file *fp;
|
|
struct knote *kn;
|
|
{
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
badfo_stat(fp, sb, active_cred, td)
|
|
struct file *fp;
|
|
struct stat *sb;
|
|
struct ucred *active_cred;
|
|
struct thread *td;
|
|
{
|
|
|
|
return (EBADF);
|
|
}
|
|
|
|
static int
|
|
badfo_close(fp, td)
|
|
struct file *fp;
|
|
struct thread *td;
|
|
{
|
|
|
|
return (EBADF);
|
|
}
|
|
|
|
SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,
|
|
fildesc_drvinit,NULL)
|
|
|
|
static void filelistinit(void *);
|
|
SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL)
|
|
|
|
/* ARGSUSED*/
|
|
static void
|
|
filelistinit(dummy)
|
|
void *dummy;
|
|
{
|
|
|
|
file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL,
|
|
NULL, NULL, UMA_ALIGN_PTR, 0);
|
|
sx_init(&filelist_lock, "filelist lock");
|
|
mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
|
|
}
|