/* $OpenBSD: kern_descrip.c,v 1.76 2007/03/15 10:22:30 art Exp $ */
/* $NetBSD: kern_descrip.c,v 1.42 1996/03/30 22:24:38 christos Exp $ */
/*
* 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 8.6 (Berkeley) 4/19/94
*/
#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/socket.h>
#include <sys/socketvar.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#include <sys/ucred.h>
#include <sys/unistd.h>
#include <sys/resourcevar.h>
#include <sys/conf.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#include <sys/event.h>
#include <sys/pool.h>
#include <uvm/uvm_extern.h>
#include <sys/pipe.h>
/*
* Descriptor management.
*/
struct filelist filehead; /* head of list of open files */
int nfiles; /* actual number of open files */
static __inline void fd_used(struct filedesc *, int);
static __inline void fd_unused(struct filedesc *, int);
static __inline int find_next_zero(u_int *, int, u_int);
int finishdup(struct proc *, struct file *, int, int, register_t *);
int find_last_set(struct filedesc *, int);
struct pool file_pool;
struct pool fdesc_pool;
void
filedesc_init(void)
{
pool_init(&file_pool, sizeof(struct file), 0, 0, 0, "filepl",
&pool_allocator_nointr);
pool_init(&fdesc_pool, sizeof(struct filedesc0), 0, 0, 0, "fdescpl",
&pool_allocator_nointr);
LIST_INIT(&filehead);
}
static __inline int
find_next_zero (u_int *bitmap, int want, u_int bits)
{
int i, off, maxoff;
u_int sub;
if (want > bits)
return -1;
off = want >> NDENTRYSHIFT;
i = want & NDENTRYMASK;
if (i) {
sub = bitmap[off] | ((u_int)~0 >> (NDENTRIES - i));
if (sub != ~0)
goto found;
off++;
}
maxoff = NDLOSLOTS(bits);
while (off < maxoff) {
if ((sub = bitmap[off]) != ~0)
goto found;
off++;
}
return -1;
found:
return (off << NDENTRYSHIFT) + ffs(~sub) - 1;
}
int
find_last_set(struct filedesc *fd, int last)
{
int off, i;
struct file **ofiles = fd->fd_ofiles;
u_int *bitmap = fd->fd_lomap;
off = (last - 1) >> NDENTRYSHIFT;
while (off >= 0 && !bitmap[off])
off--;
if (off < 0)
return 0;
i = ((off + 1) << NDENTRYSHIFT) - 1;
if (i >= last)
i = last - 1;
while (i > 0 && ofiles[i] == NULL)
i--;
return i;
}
static __inline void
fd_used(struct filedesc *fdp, int fd)
{
u_int off = fd >> NDENTRYSHIFT;
fdp->fd_lomap[off] |= 1 << (fd & NDENTRYMASK);
if (fdp->fd_lomap[off] == ~0)
fdp->fd_himap[off >> NDENTRYSHIFT] |= 1 << (off & NDENTRYMASK);
if (fd > fdp->fd_lastfile)
fdp->fd_lastfile = fd;
}
static __inline void
fd_unused(struct filedesc *fdp, int fd)
{
u_int off = fd >> NDENTRYSHIFT;
if (fd < fdp->fd_freefile)
fdp->fd_freefile = fd;
if (fdp->fd_lomap[off] == ~0)
fdp->fd_himap[off >> NDENTRYSHIFT] &= ~(1 << (off & NDENTRYMASK));
fdp->fd_lomap[off] &= ~(1 << (fd & NDENTRYMASK));
#ifdef DIAGNOSTIC
if (fd > fdp->fd_lastfile)
panic("fd_unused: fd_lastfile inconsistent");
#endif
if (fd == fdp->fd_lastfile)
fdp->fd_lastfile = find_last_set(fdp, fd);
}
struct file *
fd_getfile(struct filedesc *fdp, int fd)
{
struct file *fp;
if ((u_int)fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL)
return (NULL);
if (!FILE_IS_USABLE(fp))
return (NULL);
return (fp);
}
/*
* System calls on descriptors.
*/
/*
* Duplicate a file descriptor.
*/
/* ARGSUSED */
int
sys_dup(struct proc *p, void *v, register_t *retval)
{
struct sys_dup_args /* {
syscallarg(int) fd;
} */ *uap = v;
struct filedesc *fdp = p->p_fd;
int old = SCARG(uap, fd);
struct file *fp;
int new;
int error;
restart:
if ((fp = fd_getfile(fdp, old)) == NULL)
return (EBADF);
FREF(fp);
fdplock(fdp);
if ((error = fdalloc(p, 0, &new)) != 0) {
FRELE(fp);
if (error == ENOSPC) {
fdexpand(p);
fdpunlock(fdp);
goto restart;
}
goto out;
}
error = finishdup(p, fp, old, new, retval);
out:
fdpunlock(fdp);
return (error);
}
/*
* Duplicate a file descriptor to a particular value.
*/
/* ARGSUSED */
int
sys_dup2(struct proc *p, void *v, register_t *retval)
{
struct sys_dup2_args /* {
syscallarg(int) from;
syscallarg(int) to;
} */ *uap = v;
int old = SCARG(uap, from), new = SCARG(uap, to);
struct filedesc *fdp = p->p_fd;
struct file *fp;
int i, error;
restart:
if ((fp = fd_getfile(fdp, old)) == NULL)
return (EBADF);
if ((u_int)new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
(u_int)new >= maxfiles)
return (EBADF);
if (old == new) {
/*
* NOTE! This doesn't clear the close-on-exec flag. This might
* or might not be the intended behavior from the start, but
* this is what everyone else does.
*/
*retval = new;
return (0);
}
FREF(fp);
fdplock(fdp);
if (new >= fdp->fd_nfiles) {
if ((error = fdalloc(p, new, &i)) != 0) {
FRELE(fp);
if (error == ENOSPC) {
fdexpand(p);
fdpunlock(fdp);
goto restart;
}
goto out;
}
if (new != i)
panic("dup2: fdalloc");
}
/* finishdup() does FRELE */
error = finishdup(p, fp, old, new, retval);
out:
fdpunlock(fdp);
return (error);
}
/*
* The file control system call.
*/
/* ARGSUSED */
int
sys_fcntl(struct proc *p, void *v, register_t *retval)
{
struct sys_fcntl_args /* {
syscallarg(int) fd;
syscallarg(int) cmd;
syscallarg(void *) arg;
} */ *uap = v;
int fd = SCARG(uap, fd);
struct filedesc *fdp = p->p_fd;
struct file *fp;
struct vnode *vp;
int i, tmp, newmin, flg = F_POSIX;
struct flock fl;
int error = 0;
restart:
if ((fp = fd_getfile(fdp, fd)) == NULL)
return (EBADF);
FREF(fp);
switch (SCARG(uap, cmd)) {
case F_DUPFD:
newmin = (long)SCARG(uap, arg);
if ((u_int)newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
(u_int)newmin >= maxfiles) {
error = EINVAL;
break;
}
fdplock(fdp);
if ((error = fdalloc(p, newmin, &i)) != 0) {
if (error == ENOSPC) {
fdexpand(p);
FRELE(fp);
fdpunlock(fdp);
goto restart;
}
}
/* finishdup will FRELE for us. */
if (!error)
error = finishdup(p, fp, fd, i, retval);
else
FRELE(fp);
fdpunlock(fdp);
return (error);
case F_GETFD:
*retval = fdp->fd_ofileflags[fd] & UF_EXCLOSE ? 1 : 0;
break;
case F_SETFD:
if ((long)SCARG(uap, arg) & 1)
fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
else
fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE;
break;
case F_GETFL:
*retval = OFLAGS(fp->f_flag);
break;
case F_SETFL:
fp->f_flag &= ~FCNTLFLAGS;
fp->f_flag |= FFLAGS((long)SCARG(uap, arg)) & FCNTLFLAGS;
tmp = fp->f_flag & FNONBLOCK;
error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p);
if (error)
break;
tmp = fp->f_flag & FASYNC;
error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p);
if (!error)
break;
fp->f_flag &= ~FNONBLOCK;
tmp = 0;
(void) (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p);
break;
case F_GETOWN:
if (fp->f_type == DTYPE_SOCKET) {
*retval = ((struct socket *)fp->f_data)->so_pgid;
break;
}
error = (*fp->f_ops->fo_ioctl)
(fp, TIOCGPGRP, (caddr_t)&tmp, p);
*retval = -tmp;
break;
case F_SETOWN:
if (fp->f_type == DTYPE_SOCKET) {
struct socket *so = (struct socket *)fp->f_data;
so->so_pgid = (long)SCARG(uap, arg);
so->so_siguid = p->p_cred->p_ruid;
so->so_sigeuid = p->p_ucred->cr_uid;
break;
}
if ((long)SCARG(uap, arg) <= 0) {
SCARG(uap, arg) = (void *)(-(long)SCARG(uap, arg));
} else {
struct proc *p1 = pfind((long)SCARG(uap, arg));
if (p1 == 0) {
error = ESRCH;
break;
}
SCARG(uap, arg) = (void *)(long)p1->p_pgrp->pg_id;
}
error = ((*fp->f_ops->fo_ioctl)
(fp, TIOCSPGRP, (caddr_t)&SCARG(uap, arg), p));
break;
case F_SETLKW:
flg |= F_WAIT;
/* FALLTHROUGH */
case F_SETLK:
if (fp->f_type != DTYPE_VNODE) {
error = EBADF;
break;
}
vp = (struct vnode *)fp->f_data;
/* Copy in the lock structure */
error = copyin((caddr_t)SCARG(uap, arg), (caddr_t)&fl,
sizeof (fl));
if (error)
break;
if (fl.l_whence == SEEK_CUR) {
if (fl.l_start == 0 && fl.l_len < 0) {
/* lockf(3) compliance hack */
fl.l_len = -fl.l_len;
fl.l_start = fp->f_offset - fl.l_len;
} else
fl.l_start += fp->f_offset;
}
switch (fl.l_type) {
case F_RDLCK:
if ((fp->f_flag & FREAD) == 0) {
error = EBADF;
goto out;
}
atomic_setbits_int(&p->p_flag, P_ADVLOCK);
error = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg));
goto out;
case F_WRLCK:
if ((fp->f_flag & FWRITE) == 0) {
error = EBADF;
goto out;
}
atomic_setbits_int(&p->p_flag, P_ADVLOCK);
error = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg));
goto out;
case F_UNLCK:
error = (VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &fl,
F_POSIX));
goto out;
default:
error = EINVAL;
goto out;
}
case F_GETLK:
if (fp->f_type != DTYPE_VNODE) {
error = EBADF;
break;
}
vp = (struct vnode *)fp->f_data;
/* Copy in the lock structure */
error = copyin((caddr_t)SCARG(uap, arg), (caddr_t)&fl,
sizeof (fl));
if (error)
break;
if (fl.l_whence == SEEK_CUR) {
if (fl.l_start == 0 && fl.l_len < 0) {
/* lockf(3) compliance hack */
fl.l_len = -fl.l_len;
fl.l_start = fp->f_offset - fl.l_len;
} else
fl.l_start += fp->f_offset;
}
if (fl.l_type != F_RDLCK &&
fl.l_type != F_WRLCK &&
fl.l_type != F_UNLCK &&
fl.l_type != 0) {
error = EINVAL;
break;
}
error = VOP_ADVLOCK(vp, (caddr_t)p, F_GETLK, &fl, F_POSIX);
if (error)
break;
error = (copyout((caddr_t)&fl, (caddr_t)SCARG(uap, arg),
sizeof (fl)));
break;
default:
error = EINVAL;
break;
}
out:
FRELE(fp);
return (error);
}
/*
* Common code for dup, dup2, and fcntl(F_DUPFD).
*/
int
finishdup(struct proc *p, struct file *fp, int old, int new, register_t *retval)
{
struct file *oldfp;
struct filedesc *fdp = p->p_fd;
if (fp->f_count == LONG_MAX-2) {
FRELE(fp);
return (EDEADLK);
}
/*
* Don't fd_getfile here. We want to closef LARVAL files and
* closef can deal with that.
*/
oldfp = fdp->fd_ofiles[new];
if (oldfp != NULL)
FREF(oldfp);
fdp->fd_ofiles[new] = fp;
fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] & ~UF_EXCLOSE;
fp->f_count++;
FRELE(fp);
if (oldfp == NULL)
fd_used(fdp, new);
*retval = new;
if (oldfp != NULL) {
if (new < fdp->fd_knlistsize)
knote_fdclose(p, new);
closef(oldfp, p);
}
return (0);
}
void
fdremove(struct filedesc *fdp, int fd)
{
fdp->fd_ofiles[fd] = NULL;
fd_unused(fdp, fd);
}
int
fdrelease(struct proc *p, int fd)
{
struct filedesc *fdp = p->p_fd;
struct file **fpp, *fp;
/*
* Don't fd_getfile here. We want to closef LARVAL files and closef
* can deal with that.
*/
fpp = &fdp->fd_ofiles[fd];
fp = *fpp;
if (fp == NULL)
return (EBADF);
FREF(fp);
*fpp = NULL;
fdp->fd_ofileflags[fd] = 0;
fd_unused(fdp, fd);
if (fd < fdp->fd_knlistsize)
knote_fdclose(p, fd);
return (closef(fp, p));
}
/*
* Close a file descriptor.
*/
/* ARGSUSED */
int
sys_close(struct proc *p, void *v, register_t *retval)
{
struct sys_close_args /* {
syscallarg(int) fd;
} */ *uap = v;
int fd = SCARG(uap, fd), error;
struct filedesc *fdp = p->p_fd;
if (fd_getfile(fdp, fd) == NULL)
return (EBADF);
fdplock(fdp);
error = fdrelease(p, fd);
fdpunlock(fdp);
return (error);
}
/*
* Return status information about a file descriptor.
*/
/* ARGSUSED */
int
sys_fstat(struct proc *p, void *v, register_t *retval)
{
struct sys_fstat_args /* {
syscallarg(int) fd;
syscallarg(struct stat *) sb;
} */ *uap = v;
int fd = SCARG(uap, fd);
struct filedesc *fdp = p->p_fd;
struct file *fp;
struct stat ub;
int error;
if ((fp = fd_getfile(fdp, fd)) == NULL)
return (EBADF);
FREF(fp);
error = (*fp->f_ops->fo_stat)(fp, &ub, p);
FRELE(fp);
if (error == 0) {
/*
* Don't let non-root see generation numbers
* (for NFS security)
*/
if (suser(p, 0))
ub.st_gen = 0;
error = copyout((caddr_t)&ub, (caddr_t)SCARG(uap, sb),
sizeof (ub));
}
return (error);
}
/*
* Return pathconf information about a file descriptor.
*/
/* ARGSUSED */
int
sys_fpathconf(struct proc *p, void *v, register_t *retval)
{
struct sys_fpathconf_args /* {
syscallarg(int) fd;
syscallarg(int) name;
} */ *uap = v;
int fd = SCARG(uap, fd);
struct filedesc *fdp = p->p_fd;
struct file *fp;
struct vnode *vp;
int error;
if ((fp = fd_getfile(fdp, fd)) == NULL)
return (EBADF);
FREF(fp);
switch (fp->f_type) {
case DTYPE_PIPE:
case DTYPE_SOCKET:
if (SCARG(uap, name) != _PC_PIPE_BUF) {
error = EINVAL;
break;
}
*retval = PIPE_BUF;
error = 0;
break;
case DTYPE_VNODE:
vp = (struct vnode *)fp->f_data;
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
error = VOP_PATHCONF(vp, SCARG(uap, name), retval);
VOP_UNLOCK(vp, 0, p);
break;
default:
error = EOPNOTSUPP;
break;
}
FRELE(fp);
return (error);
}
/*
* Allocate a file descriptor for the process.
*/
int
fdalloc(struct proc *p, int want, int *result)
{
struct filedesc *fdp = p->p_fd;
int lim, last, i;
u_int new, off;
/*
* Search for a free descriptor starting at the higher
* of want or fd_freefile. If that fails, consider
* expanding the ofile array.
*/
restart:
lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles);
last = min(fdp->fd_nfiles, lim);
if ((i = want) < fdp->fd_freefile)
i = fdp->fd_freefile;
off = i >> NDENTRYSHIFT;
new = find_next_zero(fdp->fd_himap, off,
(last + NDENTRIES - 1) >> NDENTRYSHIFT);
if (new != -1) {
i = find_next_zero(&fdp->fd_lomap[new],
new > off ? 0 : i & NDENTRYMASK,
NDENTRIES);
if (i == -1) {
/*
* Free file descriptor in this block was
* below want, try again with higher want.
*/
want = (new + 1) << NDENTRYSHIFT;
goto restart;
}
i += (new << NDENTRYSHIFT);
if (i < last) {
fd_used(fdp, i);
if (want <= fdp->fd_freefile)
fdp->fd_freefile = i;
*result = i;
return (0);
}
}
if (fdp->fd_nfiles >= lim)
return (EMFILE);
return (ENOSPC);
}
void
fdexpand(struct proc *p)
{
struct filedesc *fdp = p->p_fd;
int nfiles, i;
struct file **newofile;
char *newofileflags;
u_int *newhimap, *newlomap;
/*
* No space in current array.
*/
if (fdp->fd_nfiles < NDEXTENT)
nfiles = NDEXTENT;
else
nfiles = 2 * fdp->fd_nfiles;
newofile = malloc(nfiles * OFILESIZE, M_FILEDESC, M_WAITOK);
newofileflags = (char *) &newofile[nfiles];
/*
* Copy the existing ofile and ofileflags arrays
* and zero the new portion of each array.
*/
bcopy(fdp->fd_ofiles, newofile,
(i = sizeof(struct file *) * fdp->fd_nfiles));
bzero((char *)newofile + i, nfiles * sizeof(struct file *) - i);
bcopy(fdp->fd_ofileflags, newofileflags,
(i = sizeof(char) * fdp->fd_nfiles));
bzero(newofileflags + i, nfiles * sizeof(char) - i);
if (fdp->fd_nfiles > NDFILE)
free(fdp->fd_ofiles, M_FILEDESC);
if (NDHISLOTS(nfiles) > NDHISLOTS(fdp->fd_nfiles)) {
newhimap = malloc(NDHISLOTS(nfiles) * sizeof(u_int),
M_FILEDESC, M_WAITOK);
newlomap = malloc(NDLOSLOTS(nfiles) * sizeof(u_int),
M_FILEDESC, M_WAITOK);
bcopy(fdp->fd_himap, newhimap,
(i = NDHISLOTS(fdp->fd_nfiles) * sizeof(u_int)));
bzero((char *)newhimap + i,
NDHISLOTS(nfiles) * sizeof(u_int) - i);
bcopy(fdp->fd_lomap, newlomap,
(i = NDLOSLOTS(fdp->fd_nfiles) * sizeof(u_int)));
bzero((char *)newlomap + i,
NDLOSLOTS(nfiles) * sizeof(u_int) - i);
if (NDHISLOTS(fdp->fd_nfiles) > NDHISLOTS(NDFILE)) {
free(fdp->fd_himap, M_FILEDESC);
free(fdp->fd_lomap, M_FILEDESC);
}
fdp->fd_himap = newhimap;
fdp->fd_lomap = newlomap;
}
fdp->fd_ofiles = newofile;
fdp->fd_ofileflags = newofileflags;
fdp->fd_nfiles = nfiles;
}
/*
* Create a new open file structure and allocate
* a file descriptor for the process that refers to it.
*/
int
falloc(struct proc *p, struct file **resultfp, int *resultfd)
{
struct file *fp, *fq;
int error, i;
restart:
if ((error = fdalloc(p, 0, &i)) != 0) {
if (error == ENOSPC) {
fdexpand(p);
goto restart;
}
return (error);
}
if (nfiles >= maxfiles) {
fd_unused(p->p_fd, i);
tablefull("file");
return (ENFILE);
}
/*
* Allocate a new file descriptor.
* If the process has file descriptor zero open, add to the list
* of open files at that point, otherwise put it at the front of
* the list of open files.
*/
nfiles++;
fp = pool_get(&file_pool, PR_WAITOK);
bzero(fp, sizeof(struct file));
fp->f_iflags = FIF_LARVAL;
if ((fq = p->p_fd->fd_ofiles[0]) != NULL) {
LIST_INSERT_AFTER(fq, fp, f_list);
} else {
LIST_INSERT_HEAD(&filehead, fp, f_list);
}
p->p_fd->fd_ofiles[i] = fp;
fp->f_count = 1;
fp->f_cred = p->p_ucred;
crhold(fp->f_cred);
if (resultfp)
*resultfp = fp;
if (resultfd)
*resultfd = i;
FREF(fp);
return (0);
}
/*
* Build a new filedesc structure.
*/
struct filedesc *
fdinit(struct proc *p)
{
struct filedesc0 *newfdp;
extern int cmask;
newfdp = pool_get(&fdesc_pool, PR_WAITOK);
bzero(newfdp, sizeof(struct filedesc0));
if (p != NULL) {
struct filedesc *fdp = p->p_fd;
newfdp->fd_fd.fd_cdir = fdp->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);
}
rw_init(&newfdp->fd_fd.fd_lock, "fdlock");
/* 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_himap = newfdp->fd_dhimap;
newfdp->fd_fd.fd_lomap = newfdp->fd_dlomap;
newfdp->fd_fd.fd_knlistsize = -1;
newfdp->fd_fd.fd_freefile = 0;
newfdp->fd_fd.fd_lastfile = 0;
return (&newfdp->fd_fd);
}
/*
* Share a filedesc structure.
*/
struct filedesc *
fdshare(struct proc *p)
{
p->p_fd->fd_refcnt++;
return (p->p_fd);
}
/*
* Copy a filedesc structure.
*/
struct filedesc *
fdcopy(struct proc *p)
{
struct filedesc *newfdp, *fdp = p->p_fd;
struct file **fpp;
int i;
newfdp = pool_get(&fdesc_pool, PR_WAITOK);
bcopy(fdp, newfdp, sizeof(struct filedesc));
if (newfdp->fd_cdir)
VREF(newfdp->fd_cdir);
if (newfdp->fd_rdir)
VREF(newfdp->fd_rdir);
newfdp->fd_refcnt = 1;
/*
* If the number of open files fits in the internal arrays
* of the open file structure, use them, otherwise allocate
* additional memory for the number of descriptors currently
* in use.
*/
if (newfdp->fd_lastfile < NDFILE) {
newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles;
newfdp->fd_ofileflags =
((struct filedesc0 *) newfdp)->fd_dfileflags;
i = NDFILE;
} else {
/*
* Compute the smallest multiple of NDEXTENT needed
* for the file descriptors currently in use,
* allowing the table to shrink.
*/
i = newfdp->fd_nfiles;
while (i >= 2 * NDEXTENT && i > newfdp->fd_lastfile * 2)
i /= 2;
newfdp->fd_ofiles = malloc(i * OFILESIZE, M_FILEDESC, M_WAITOK);
newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i];
}
if (NDHISLOTS(i) <= NDHISLOTS(NDFILE)) {
newfdp->fd_himap =
((struct filedesc0 *) newfdp)->fd_dhimap;
newfdp->fd_lomap =
((struct filedesc0 *) newfdp)->fd_dlomap;
} else {
newfdp->fd_himap = malloc(NDHISLOTS(i) * sizeof(u_int),
M_FILEDESC, M_WAITOK);
newfdp->fd_lomap = malloc(NDLOSLOTS(i) * sizeof(u_int),
M_FILEDESC, M_WAITOK);
}
newfdp->fd_nfiles = i;
bcopy(fdp->fd_ofiles, newfdp->fd_ofiles, i * sizeof(struct file **));
bcopy(fdp->fd_ofileflags, newfdp->fd_ofileflags, i * sizeof(char));
bcopy(fdp->fd_himap, newfdp->fd_himap, NDHISLOTS(i) * sizeof(u_int));
bcopy(fdp->fd_lomap, newfdp->fd_lomap, NDLOSLOTS(i) * sizeof(u_int));
/*
* kq descriptors cannot be copied.
*/
if (newfdp->fd_knlistsize != -1) {
fpp = newfdp->fd_ofiles;
for (i = 0; i <= newfdp->fd_lastfile; i++, fpp++)
if (*fpp != NULL && (*fpp)->f_type == DTYPE_KQUEUE)
fdremove(newfdp, i);
newfdp->fd_knlist = NULL;
newfdp->fd_knlistsize = -1;
newfdp->fd_knhash = NULL;
newfdp->fd_knhashmask = 0;
}
fpp = newfdp->fd_ofiles;
for (i = 0; i <= newfdp->fd_lastfile; i++, fpp++)
if (*fpp != NULL) {
/*
* XXX Gruesome hack. If count gets too high, fail
* to copy an fd, since fdcopy()'s callers do not
* permit it to indicate failure yet.
*/
if ((*fpp)->f_count == LONG_MAX-2)
fdremove(newfdp, i);
else
(*fpp)->f_count++;
}
return (newfdp);
}
/*
* Release a filedesc structure.
*/
void
fdfree(struct proc *p)
{
struct filedesc *fdp = p->p_fd;
struct file **fpp, *fp;
int i;
if (--fdp->fd_refcnt > 0)
return;
fpp = fdp->fd_ofiles;
for (i = fdp->fd_lastfile; i >= 0; i--, fpp++) {
fp = *fpp;
if (fp != NULL) {
FREF(fp);
*fpp = NULL;
(void) closef(fp, p);
}
}
p->p_fd = NULL;
if (fdp->fd_nfiles > NDFILE)
free(fdp->fd_ofiles, M_FILEDESC);
if (NDHISLOTS(fdp->fd_nfiles) > NDHISLOTS(NDFILE)) {
free(fdp->fd_himap, M_FILEDESC);
free(fdp->fd_lomap, M_FILEDESC);
}
if (fdp->fd_cdir)
vrele(fdp->fd_cdir);
if (fdp->fd_rdir)
vrele(fdp->fd_rdir);
if (fdp->fd_knlist)
FREE(fdp->fd_knlist, M_TEMP);
if (fdp->fd_knhash)
FREE(fdp->fd_knhash, M_TEMP);
pool_put(&fdesc_pool, fdp);
}
/*
* Internal form of close.
* Decrement reference count on file structure.
* Note: p may be NULL when closing a file
* that was being passed in a message.
*
* The fp must have its usecount bumped and will be FRELEd here.
*/
int
closef(struct file *fp, struct proc *p)
{
struct vnode *vp;
struct flock lf;
int error;
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 (p && (p->p_flag & P_ADVLOCK) && fp->f_type == DTYPE_VNODE) {
lf.l_whence = SEEK_SET;
lf.l_start = 0;
lf.l_len = 0;
lf.l_type = F_UNLCK;
vp = (struct vnode *)fp->f_data;
(void) VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_POSIX);
}
/*
* Some files passed to this function could be accessed
* without a FILE_IS_USABLE check (and in some cases it's perfectly
* legal), we must beware of files where someone already won the
* race to FIF_WANTCLOSE.
*/
if ((fp->f_iflags & FIF_WANTCLOSE) != 0) {
FRELE(fp);
return (0);
}
if (--fp->f_count > 0) {
FRELE(fp);
return (0);
}
#ifdef DIAGNOSTIC
if (fp->f_count < 0)
panic("closef: count < 0");
#endif
/* Wait for the last usecount to drain. */
fp->f_iflags |= FIF_WANTCLOSE;
while (fp->f_usecount > 1)
tsleep(&fp->f_usecount, PRIBIO, "closef", 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 = (struct vnode *)fp->f_data;
(void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
}
if (fp->f_ops)
error = (*fp->f_ops->fo_close)(fp, p);
else
error = 0;
/* Free fp */
LIST_REMOVE(fp, f_list);
crfree(fp->f_cred);
#ifdef DIAGNOSTIC
if (fp->f_count != 0 || fp->f_usecount != 1)
panic("closef: count: %d/%d", fp->f_count, fp->f_usecount);
#endif
nfiles--;
pool_put(&file_pool, fp);
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 proc *p, void *v, register_t *retval)
{
struct sys_flock_args /* {
syscallarg(int) fd;
syscallarg(int) how;
} */ *uap = v;
int fd = SCARG(uap, fd);
int how = SCARG(uap, how);
struct filedesc *fdp = p->p_fd;
struct file *fp;
struct vnode *vp;
struct flock lf;
int error;
if ((fp = fd_getfile(fdp, fd)) == NULL)
return (EBADF);
if (fp->f_type != DTYPE_VNODE)
return (EOPNOTSUPP);
vp = (struct vnode *)fp->f_data;
lf.l_whence = SEEK_SET;
lf.l_start = 0;
lf.l_len = 0;
if (how & LOCK_UN) {
lf.l_type = F_UNLCK;
fp->f_flag &= ~FHASLOCK;
error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
goto out;
}
if (how & LOCK_EX)
lf.l_type = F_WRLCK;
else if (how & LOCK_SH)
lf.l_type = F_RDLCK;
else {
error = EINVAL;
goto out;
}
fp->f_flag |= FHASLOCK;
if (how & LOCK_NB)
error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK);
else
error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK|F_WAIT);
out:
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 */
int
filedescopen(dev_t dev, int mode, int type, struct proc *p)
{
/*
* XXX Kludge: set curproc->p_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.
*/
p->p_dupfd = minor(dev);
return (ENODEV);
}
/*
* Duplicate the specified descriptor to a free descriptor.
*/
int
dupfdopen(struct filedesc *fdp, int indx, int dfd, int mode, int error)
{
struct file *wfp;
/*
* Assume that the filename was user-specified; applications do
* not tend to open /dev/fd/# when they can just call dup()
*/
if ((curproc->p_flag & (P_SUGIDEXEC | P_SUGID))) {
if (curproc->p_descfd == 255)
return (EPERM);
if (curproc->p_descfd != curproc->p_dupfd)
return (EPERM);
}
/*
* 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, reject. Note, there is no need to check for new == old
* because fd_getfile will return NULL if the file at indx is
* newly created by falloc (FIF_LARVAL).
*/
if ((wfp = fd_getfile(fdp, dfd)) == NULL)
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.
*/
if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag)
return (EACCES);
if (wfp->f_count == LONG_MAX-2)
return (EDEADLK);
fdp->fd_ofiles[indx] = wfp;
fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
wfp->f_count++;
fd_used(fdp, indx);
return (0);
case ENXIO:
/*
* Steal away the file pointer from dfd, and stuff it into indx.
*/
fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd];
fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
fdp->fd_ofiles[dfd] = NULL;
fdp->fd_ofileflags[dfd] = 0;
/*
* Complete the clean up of the filedesc structure by
* recomputing the various hints.
*/
fd_used(fdp, indx);
fd_unused(fdp, dfd);
return (0);
default:
return (error);
}
/* NOTREACHED */
}
/*
* Close any files on exec?
*/
void
fdcloseexec(struct proc *p)
{
struct filedesc *fdp = p->p_fd;
int fd;
for (fd = 0; fd <= fdp->fd_lastfile; fd++)
if (fdp->fd_ofileflags[fd] & UF_EXCLOSE)
(void) fdrelease(p, fd);
}
int
sys_closefrom(struct proc *p, void *v, register_t *retval)
{
struct sys_closefrom_args *uap = v;
struct filedesc *fdp = p->p_fd;
u_int startfd, i;
startfd = SCARG(uap, fd);
fdplock(fdp);
if (startfd > fdp->fd_lastfile) {
fdpunlock(fdp);
return (EBADF);
}
for (i = startfd; i <= fdp->fd_lastfile; i++)
fdrelease(p, i);
fdpunlock(fdp);
return (0);
}
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