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freebsd/sys/kern/kern_descrip.c
Konstantin Belousov 1744fe5048 When growing the file descriptor table, new larger memory chunk is 
allocated, but the old table is kept around to handle the case of
threads still performing unlocked accesses to it.

Grow the table exponentially instead of increasing its size by
sizeof(long) * 8 chunks when overflowing. This mode significantly
reduces the total memory use for the processes consuming large numbers
of the file descriptors which open them one by one.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Approved by:	re (marius)
2013-10-09 18:41:35 +00:00

4055 lines
92 KiB
C
Raw Blame History

/*-
* 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.
* 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_capsicum.h"
#include "opt_compat.h"
#include "opt_ddb.h"
#include "opt_ktrace.h"
#include "opt_procdesc.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/capability.h>
#include <sys/conf.h>
#include <sys/domain.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/filio.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/ksem.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/mqueue.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/selinfo.h>
#include <sys/pipe.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/procdesc.h>
#include <sys/protosw.h>
#include <sys/racct.h>
#include <sys/resourcevar.h>
#include <sys/sbuf.h>
#include <sys/signalvar.h>
#include <sys/socketvar.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysproto.h>
#include <sys/tty.h>
#include <sys/unistd.h>
#include <sys/un.h>
#include <sys/unpcb.h>
#include <sys/user.h>
#include <sys/vnode.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <security/audit/audit.h>
#include <vm/uma.h>
#include <vm/vm.h>
#include <ddb/ddb.h>
static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table");
static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader",
"file desc to leader structures");
static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities");
MALLOC_DECLARE(M_FADVISE);
static uma_zone_t file_zone;
void (*ksem_info)(struct ksem *ks, char *path, size_t size, uint32_t *value);
static int closefp(struct filedesc *fdp, int fd, struct file *fp,
struct thread *td, int holdleaders);
static int fd_first_free(struct filedesc *fdp, int low, int size);
static int fd_last_used(struct filedesc *fdp, int size);
static void fdgrowtable(struct filedesc *fdp, int nfd);
static void fdgrowtable_exp(struct filedesc *fdp, int nfd);
static void fdunused(struct filedesc *fdp, int fd);
static void fdused(struct filedesc *fdp, int fd);
static int fill_pipe_info(struct pipe *pi, struct kinfo_file *kif);
static int fill_procdesc_info(struct procdesc *pdp,
struct kinfo_file *kif);
static int fill_pts_info(struct tty *tp, struct kinfo_file *kif);
static int fill_sem_info(struct file *fp, struct kinfo_file *kif);
static int fill_shm_info(struct file *fp, struct kinfo_file *kif);
static int fill_socket_info(struct socket *so, struct kinfo_file *kif);
static int fill_vnode_info(struct vnode *vp, struct kinfo_file *kif);
static int getmaxfd(struct proc *p);
/*
* Each process has:
*
* - An array of open file descriptors (fd_ofiles)
* - An array of file flags (fd_ofileflags)
* - A bitmap recording which descriptors are in use (fd_map)
*
* A process starts out with NDFILE descriptors. The value of NDFILE has
* been selected based the historical limit of 20 open files, and an
* assumption that the majority of processes, especially short-lived
* processes like shells, will never need more.
*
* If this initial allocation is exhausted, a larger descriptor table and
* map are allocated dynamically, and the pointers in the process's struct
* filedesc are updated to point to those. This is repeated every time
* the process runs out of file descriptors (provided it hasn't hit its
* resource limit).
*
* Since threads may hold references to individual descriptor table
* entries, the tables are never freed. Instead, they are placed on a
* linked list and freed only when the struct filedesc is released.
*/
#define NDFILE 20
#define NDSLOTSIZE sizeof(NDSLOTTYPE)
#define NDENTRIES (NDSLOTSIZE * __CHAR_BIT)
#define NDSLOT(x) ((x) / NDENTRIES)
#define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES))
#define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES)
/*
* SLIST entry used to keep track of ofiles which must be reclaimed when
* the process exits.
*/
struct freetable {
struct filedescent *ft_table;
SLIST_ENTRY(freetable) ft_next;
};
/*
* Initial allocation: a filedesc structure + the head of SLIST used to
* keep track of old ofiles + enough space for NDFILE descriptors.
*/
struct filedesc0 {
struct filedesc fd_fd;
SLIST_HEAD(, freetable) fd_free;
struct filedescent fd_dfiles[NDFILE];
NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)];
};
/*
* Descriptor management.
*/
volatile int openfiles; /* actual number of open files */
struct mtx sigio_lock; /* mtx to protect pointers to sigio */
void (*mq_fdclose)(struct thread *td, int fd, struct file *fp);
/* A mutex to protect the association between a proc and filedesc. */
static struct mtx fdesc_mtx;
/*
* If low >= size, just return low. Otherwise find the first zero bit in the
* given bitmap, starting at low and not exceeding size - 1. Return size if
* not found.
*/
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 0 and
* not exceeding size - 1. Return -1 if not found.
*/
static int
fd_last_used(struct filedesc *fdp, int size)
{
NDSLOTTYPE *map = fdp->fd_map;
NDSLOTTYPE mask;
int off, minoff;
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(0); off >= minoff; --off)
if (map[off] != 0)
return (off * NDENTRIES + flsl(map[off]) - 1);
return (-1);
}
static int
fdisused(struct filedesc *fdp, int fd)
{
FILEDESC_LOCK_ASSERT(fdp);
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.
*/
static void
fdused(struct filedesc *fdp, int fd)
{
FILEDESC_XLOCK_ASSERT(fdp);
KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd));
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.
*/
static void
fdunused(struct filedesc *fdp, int fd)
{
FILEDESC_XLOCK_ASSERT(fdp);
KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd));
KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
("fd=%d is still in use", fd));
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, fd);
}
/*
* Free a file descriptor.
*/
static inline void
fdfree(struct filedesc *fdp, int fd)
{
struct filedescent *fde;
fde = &fdp->fd_ofiles[fd];
filecaps_free(&fde->fde_caps);
bzero(fde, sizeof(*fde));
fdunused(fdp, fd);
}
/*
* System calls on descriptors.
*/
#ifndef _SYS_SYSPROTO_H_
struct getdtablesize_args {
int dummy;
};
#endif
/* ARGSUSED */
int
sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap)
{
struct proc *p = td->td_proc;
uint64_t lim;
PROC_LOCK(p);
td->td_retval[0] =
min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
lim = racct_get_limit(td->td_proc, RACCT_NOFILE);
PROC_UNLOCK(p);
if (lim < td->td_retval[0])
td->td_retval[0] = lim;
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
/* ARGSUSED */
int
sys_dup2(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
/* ARGSUSED */
int
sys_dup(struct thread *td, struct dup_args *uap)
{
return (do_dup(td, 0, (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
/* ARGSUSED */
int
sys_fcntl(struct thread *td, struct fcntl_args *uap)
{
struct flock fl;
struct __oflock ofl;
intptr_t arg;
int error;
int cmd;
error = 0;
cmd = uap->cmd;
switch (uap->cmd) {
case F_OGETLK:
case F_OSETLK:
case F_OSETLKW:
/*
* Convert old flock structure to new.
*/
error = copyin((void *)(intptr_t)uap->arg, &ofl, sizeof(ofl));
fl.l_start = ofl.l_start;
fl.l_len = ofl.l_len;
fl.l_pid = ofl.l_pid;
fl.l_type = ofl.l_type;
fl.l_whence = ofl.l_whence;
fl.l_sysid = 0;
switch (uap->cmd) {
case F_OGETLK:
cmd = F_GETLK;
break;
case F_OSETLK:
cmd = F_SETLK;
break;
case F_OSETLKW:
cmd = F_SETLKW;
break;
}
arg = (intptr_t)&fl;
break;
case F_GETLK:
case F_SETLK:
case F_SETLKW:
case F_SETLK_REMOTE:
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, cmd, arg);
if (error)
return (error);
if (uap->cmd == F_OGETLK) {
ofl.l_start = fl.l_start;
ofl.l_len = fl.l_len;
ofl.l_pid = fl.l_pid;
ofl.l_type = fl.l_type;
ofl.l_whence = fl.l_whence;
error = copyout(&ofl, (void *)(intptr_t)uap->arg, sizeof(ofl));
} else 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, *fp2;
struct filedescent *fde;
struct proc *p;
struct vnode *vp;
cap_rights_t rights;
int error, flg, tmp;
u_int old, new;
uint64_t bsize;
off_t foffset;
error = 0;
flg = F_POSIX;
p = td->td_proc;
fdp = p->p_fd;
switch (cmd) {
case F_DUPFD:
tmp = arg;
error = do_dup(td, DUP_FCNTL, fd, tmp, td->td_retval);
break;
case F_DUPFD_CLOEXEC:
tmp = arg;
error = do_dup(td, DUP_FCNTL | DUP_CLOEXEC, fd, tmp,
td->td_retval);
break;
case F_DUP2FD:
tmp = arg;
error = do_dup(td, DUP_FIXED, fd, tmp, td->td_retval);
break;
case F_DUP2FD_CLOEXEC:
tmp = arg;
error = do_dup(td, DUP_FIXED | DUP_CLOEXEC, fd, tmp,
td->td_retval);
break;
case F_GETFD:
FILEDESC_SLOCK(fdp);
if ((fp = fget_locked(fdp, fd)) == NULL) {
FILEDESC_SUNLOCK(fdp);
error = EBADF;
break;
}
fde = &fdp->fd_ofiles[fd];
td->td_retval[0] =
(fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0;
FILEDESC_SUNLOCK(fdp);
break;
case F_SETFD:
FILEDESC_XLOCK(fdp);
if ((fp = fget_locked(fdp, fd)) == NULL) {
FILEDESC_XUNLOCK(fdp);
error = EBADF;
break;
}
fde = &fdp->fd_ofiles[fd];
fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) |
(arg & FD_CLOEXEC ? UF_EXCLOSE : 0);
FILEDESC_XUNLOCK(fdp);
break;
case F_GETFL:
error = fget_unlocked(fdp, fd,
cap_rights_init(&rights, CAP_FCNTL), F_GETFL, &fp, NULL);
if (error != 0)
break;
td->td_retval[0] = OFLAGS(fp->f_flag);
fdrop(fp, td);
break;
case F_SETFL:
error = fget_unlocked(fdp, fd,
cap_rights_init(&rights, CAP_FCNTL), F_SETFL, &fp, NULL);
if (error != 0)
break;
do {
tmp = flg = fp->f_flag;
tmp &= ~FCNTLFLAGS;
tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS;
} while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
tmp = fp->f_flag & FNONBLOCK;
error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
if (error != 0) {
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;
}
atomic_clear_int(&fp->f_flag, FNONBLOCK);
tmp = 0;
(void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
fdrop(fp, td);
break;
case F_GETOWN:
error = fget_unlocked(fdp, fd,
cap_rights_init(&rights, CAP_FCNTL), F_GETOWN, &fp, NULL);
if (error != 0)
break;
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:
error = fget_unlocked(fdp, fd,
cap_rights_init(&rights, CAP_FCNTL), F_SETOWN, &fp, NULL);
if (error != 0)
break;
tmp = arg;
error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td);
fdrop(fp, td);
break;
case F_SETLK_REMOTE:
error = priv_check(td, PRIV_NFS_LOCKD);
if (error)
return (error);
flg = F_REMOTE;
goto do_setlk;
case F_SETLKW:
flg |= F_WAIT;
/* FALLTHROUGH F_SETLK */
case F_SETLK:
do_setlk:
cap_rights_init(&rights, CAP_FLOCK);
error = fget_unlocked(fdp, fd, &rights, 0, &fp, NULL);
if (error != 0)
break;
if (fp->f_type != DTYPE_VNODE) {
error = EBADF;
fdrop(fp, td);
break;
}
flp = (struct flock *)arg;
if (flp->l_whence == SEEK_CUR) {
foffset = foffset_get(fp);
if (foffset < 0 ||
(flp->l_start > 0 &&
foffset > OFF_MAX - flp->l_start)) {
FILEDESC_SUNLOCK(fdp);
error = EOVERFLOW;
fdrop(fp, td);
break;
}
flp->l_start += foffset;
}
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, flg);
break;
case F_UNLCKSYS:
/*
* Temporary api for testing remote lock
* infrastructure.
*/
if (flg != F_REMOTE) {
error = EINVAL;
break;
}
error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
F_UNLCKSYS, flp, flg);
break;
default:
error = EINVAL;
break;
}
if (error != 0 || flp->l_type == F_UNLCK ||
flp->l_type == F_UNLCKSYS) {
fdrop(fp, td);
break;
}
/*
* Check for a race with close.
*
* The vnode is now advisory locked (or unlocked, but this case
* is not really important) as the caller requested.
* We had to drop the filedesc lock, so we need to recheck if
* the descriptor is still valid, because if it was closed
* in the meantime we need to remove advisory lock from the
* vnode - close on any descriptor leading to an advisory
* locked vnode, removes that lock.
* We will return 0 on purpose in that case, as the result of
* successful advisory lock might have been externally visible
* already. This is fine - effectively we pretend to the caller
* that the closing thread was a bit slower and that the
* advisory lock succeeded before the close.
*/
error = fget_unlocked(fdp, fd, &rights, 0, &fp2, NULL);
if (error != 0) {
fdrop(fp, td);
break;
}
if (fp != fp2) {
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);
}
fdrop(fp, td);
fdrop(fp2, td);
break;
case F_GETLK:
error = fget_unlocked(fdp, fd,
cap_rights_init(&rights, CAP_FLOCK), 0, &fp, NULL);
if (error != 0)
break;
if (fp->f_type != DTYPE_VNODE) {
error = EBADF;
fdrop(fp, td);
break;
}
flp = (struct flock *)arg;
if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK &&
flp->l_type != F_UNLCK) {
error = EINVAL;
fdrop(fp, td);
break;
}
if (flp->l_whence == SEEK_CUR) {
foffset = foffset_get(fp);
if ((flp->l_start > 0 &&
foffset > OFF_MAX - flp->l_start) ||
(flp->l_start < 0 &&
foffset < OFF_MIN - flp->l_start)) {
FILEDESC_SUNLOCK(fdp);
error = EOVERFLOW;
fdrop(fp, td);
break;
}
flp->l_start += foffset;
}
vp = fp->f_vnode;
error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp,
F_POSIX);
fdrop(fp, td);
break;
case F_RDAHEAD:
arg = arg ? 128 * 1024: 0;
/* FALLTHROUGH */
case F_READAHEAD:
error = fget_unlocked(fdp, fd, NULL, 0, &fp, NULL);
if (error != 0)
break;
if (fp->f_type != DTYPE_VNODE) {
fdrop(fp, td);
error = EBADF;
break;
}
if (arg >= 0) {
vp = fp->f_vnode;
error = vn_lock(vp, LK_SHARED);
if (error != 0) {
fdrop(fp, td);
break;
}
bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize;
VOP_UNLOCK(vp, 0);
fp->f_seqcount = (arg + bsize - 1) / bsize;
do {
new = old = fp->f_flag;
new |= FRDAHEAD;
} while (!atomic_cmpset_rel_int(&fp->f_flag, old, new));
} else {
do {
new = old = fp->f_flag;
new &= ~FRDAHEAD;
} while (!atomic_cmpset_rel_int(&fp->f_flag, old, new));
}
fdrop(fp, td);
break;
default:
error = EINVAL;
break;
}
return (error);
}
static int
getmaxfd(struct proc *p)
{
int maxfd;
PROC_LOCK(p);
maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
PROC_UNLOCK(p);
return (maxfd);
}
/*
* Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
*/
int
do_dup(struct thread *td, int flags, int old, int new,
register_t *retval)
{
struct filedesc *fdp;
struct filedescent *oldfde, *newfde;
struct proc *p;
struct file *fp;
struct file *delfp;
int error, maxfd;
p = td->td_proc;
fdp = p->p_fd;
/*
* Verify we have a valid descriptor to dup from and possibly to
* dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should
* return EINVAL when the new descriptor is out of bounds.
*/
if (old < 0)
return (EBADF);
if (new < 0)
return (flags & DUP_FCNTL ? EINVAL : EBADF);
maxfd = getmaxfd(p);
if (new >= maxfd)
return (flags & DUP_FCNTL ? EINVAL : EBADF);
FILEDESC_XLOCK(fdp);
if (fget_locked(fdp, old) == NULL) {
FILEDESC_XUNLOCK(fdp);
return (EBADF);
}
oldfde = &fdp->fd_ofiles[old];
if (flags & DUP_FIXED && old == new) {
*retval = new;
if (flags & DUP_CLOEXEC)
fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE;
FILEDESC_XUNLOCK(fdp);
return (0);
}
fp = oldfde->fde_file;
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.
*/
if (flags & DUP_FIXED) {
if (new >= fdp->fd_nfiles) {
/*
* The resource limits are here instead of e.g.
* fdalloc(), because the file descriptor table may be
* shared between processes, so we can't really use
* racct_add()/racct_sub(). Instead of counting the
* number of actually allocated descriptors, just put
* the limit on the size of the file descriptor table.
*/
#ifdef RACCT
PROC_LOCK(p);
error = racct_set(p, RACCT_NOFILE, new + 1);
PROC_UNLOCK(p);
if (error != 0) {
FILEDESC_XUNLOCK(fdp);
fdrop(fp, td);
return (EMFILE);
}
#endif
fdgrowtable_exp(fdp, new + 1);
oldfde = &fdp->fd_ofiles[old];
}
newfde = &fdp->fd_ofiles[new];
if (newfde->fde_file == NULL)
fdused(fdp, new);
} else {
if ((error = fdalloc(td, new, &new)) != 0) {
FILEDESC_XUNLOCK(fdp);
fdrop(fp, td);
return (error);
}
newfde = &fdp->fd_ofiles[new];
}
KASSERT(fp == oldfde->fde_file, ("old fd has been modified"));
KASSERT(old != new, ("new fd is same as old"));
delfp = newfde->fde_file;
/*
* Duplicate the source descriptor.
*/
*newfde = *oldfde;
filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps);
if ((flags & DUP_CLOEXEC) != 0)
newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE;
else
newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE;
if (new > fdp->fd_lastfile)
fdp->fd_lastfile = new;
*retval = new;
if (delfp != NULL) {
(void) closefp(fdp, new, delfp, td, 1);
/* closefp() drops the FILEDESC lock for us. */
} else {
FILEDESC_XUNLOCK(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(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
* inaccessible to callers of fsetown and therefore do not need to lock
* the proc or pgrp struct for the list manipulation.
*/
void
funsetownlst(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(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. */
sigio = malloc(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);
}
/*
* Function drops the filedesc lock on return.
*/
static int
closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
int holdleaders)
{
int error;
FILEDESC_XLOCK_ASSERT(fdp);
if (holdleaders) {
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++;
} else {
holdleaders = 0;
}
}
/*
* We now hold the fp reference that used to be owned by the
* descriptor array. We have to unlock the FILEDESC *AFTER*
* knote_fdclose to prevent a race of the fd getting opened, a knote
* added, and deleteing a knote for the new fd.
*/
knote_fdclose(td, fd);
/*
* We need to notify mqueue if the object is of type mqueue.
*/
if (fp->f_type == DTYPE_MQUEUE)
mq_fdclose(td, fd, fp);
FILEDESC_XUNLOCK(fdp);
error = closef(fp, td);
if (holdleaders) {
FILEDESC_XLOCK(fdp);
fdp->fd_holdleaderscount--;
if (fdp->fd_holdleaderscount == 0 &&
fdp->fd_holdleaderswakeup != 0) {
fdp->fd_holdleaderswakeup = 0;
wakeup(&fdp->fd_holdleaderscount);
}
FILEDESC_XUNLOCK(fdp);
}
return (error);
}
/*
* Close a file descriptor.
*/
#ifndef _SYS_SYSPROTO_H_
struct close_args {
int fd;
};
#endif
/* ARGSUSED */
int
sys_close(td, uap)
struct thread *td;
struct close_args *uap;
{
return (kern_close(td, uap->fd));
}
int
kern_close(td, fd)
struct thread *td;
int fd;
{
struct filedesc *fdp;
struct file *fp;
fdp = td->td_proc->p_fd;
AUDIT_SYSCLOSE(td, fd);
FILEDESC_XLOCK(fdp);
if ((fp = fget_locked(fdp, fd)) == NULL) {
FILEDESC_XUNLOCK(fdp);
return (EBADF);
}
fdfree(fdp, fd);
/* closefp() drops the FILEDESC lock for us. */
return (closefp(fdp, fd, fp, td, 1));
}
/*
* Close open file descriptors.
*/
#ifndef _SYS_SYSPROTO_H_
struct closefrom_args {
int lowfd;
};
#endif
/* ARGSUSED */
int
sys_closefrom(struct thread *td, struct closefrom_args *uap)
{
struct filedesc *fdp;
int fd;
fdp = td->td_proc->p_fd;
AUDIT_ARG_FD(uap->lowfd);
/*
* Treat negative starting file descriptor values identical to
* closefrom(0) which closes all files.
*/
if (uap->lowfd < 0)
uap->lowfd = 0;
FILEDESC_SLOCK(fdp);
for (fd = uap->lowfd; fd < fdp->fd_nfiles; fd++) {
if (fdp->fd_ofiles[fd].fde_file != NULL) {
FILEDESC_SUNLOCK(fdp);
(void)kern_close(td, fd);
FILEDESC_SLOCK(fdp);
}
}
FILEDESC_SUNLOCK(fdp);
return (0);
}
#if defined(COMPAT_43)
/*
* Return status information about a file descriptor.
*/
#ifndef _SYS_SYSPROTO_H_
struct ofstat_args {
int fd;
struct ostat *sb;
};
#endif
/* ARGSUSED */
int
ofstat(struct thread *td, struct ofstat_args *uap)
{
struct ostat oub;
struct stat ub;
int error;
error = kern_fstat(td, uap->fd, &ub);
if (error == 0) {
cvtstat(&ub, &oub);
error = copyout(&oub, uap->sb, sizeof(oub));
}
return (error);
}
#endif /* COMPAT_43 */
/*
* Return status information about a file descriptor.
*/
#ifndef _SYS_SYSPROTO_H_
struct fstat_args {
int fd;
struct stat *sb;
};
#endif
/* ARGSUSED */
int
sys_fstat(struct thread *td, struct fstat_args *uap)
{
struct stat ub;
int error;
error = kern_fstat(td, uap->fd, &ub);
if (error == 0)
error = copyout(&ub, uap->sb, sizeof(ub));
return (error);
}
int
kern_fstat(struct thread *td, int fd, struct stat *sbp)
{
struct file *fp;
cap_rights_t rights;
int error;
AUDIT_ARG_FD(fd);
error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp);
if (error != 0)
return (error);
AUDIT_ARG_FILE(td->td_proc, fp);
error = fo_stat(fp, sbp, td->td_ucred, td);
fdrop(fp, td);
#ifdef KTRACE
if (error == 0 && KTRPOINT(td, KTR_STRUCT))
ktrstat(sbp);
#endif
return (error);
}
/*
* Return status information about a file descriptor.
*/
#ifndef _SYS_SYSPROTO_H_
struct nfstat_args {
int fd;
struct nstat *sb;
};
#endif
/* ARGSUSED */
int
sys_nfstat(struct thread *td, struct nfstat_args *uap)
{
struct nstat nub;
struct stat ub;
int error;
error = kern_fstat(td, uap->fd, &ub);
if (error == 0) {
cvtnstat(&ub, &nub);
error = copyout(&nub, uap->sb, sizeof(nub));
}
return (error);
}
/*
* Return pathconf information about a file descriptor.
*/
#ifndef _SYS_SYSPROTO_H_
struct fpathconf_args {
int fd;
int name;
};
#endif
/* ARGSUSED */
int
sys_fpathconf(struct thread *td, struct fpathconf_args *uap)
{
struct file *fp;
struct vnode *vp;
cap_rights_t rights;
int error;
error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp);
if (error != 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) {
vn_lock(vp, LK_SHARED | LK_RETRY);
error = VOP_PATHCONF(vp, uap->name, td->td_retval);
VOP_UNLOCK(vp, 0);
} 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);
}
/*
* Initialize filecaps structure.
*/
void
filecaps_init(struct filecaps *fcaps)
{
bzero(fcaps, sizeof(*fcaps));
fcaps->fc_nioctls = -1;
}
/*
* Copy filecaps structure allocating memory for ioctls array if needed.
*/
void
filecaps_copy(const struct filecaps *src, struct filecaps *dst)
{
size_t size;
*dst = *src;
if (src->fc_ioctls != NULL) {
KASSERT(src->fc_nioctls > 0,
("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls));
size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK);
bcopy(src->fc_ioctls, dst->fc_ioctls, size);
}
}
/*
* Move filecaps structure to the new place and clear the old place.
*/
void
filecaps_move(struct filecaps *src, struct filecaps *dst)
{
*dst = *src;
bzero(src, sizeof(*src));
}
/*
* Fill the given filecaps structure with full rights.
*/
static void
filecaps_fill(struct filecaps *fcaps)
{
CAP_ALL(&fcaps->fc_rights);
fcaps->fc_ioctls = NULL;
fcaps->fc_nioctls = -1;
fcaps->fc_fcntls = CAP_FCNTL_ALL;
}
/*
* Free memory allocated within filecaps structure.
*/
void
filecaps_free(struct filecaps *fcaps)
{
free(fcaps->fc_ioctls, M_FILECAPS);
bzero(fcaps, sizeof(*fcaps));
}
/*
* Validate the given filecaps structure.
*/
static void
filecaps_validate(const struct filecaps *fcaps, const char *func)
{
KASSERT(cap_rights_is_valid(&fcaps->fc_rights),
("%s: invalid rights", func));
KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0,
("%s: invalid fcntls", func));
KASSERT(fcaps->fc_fcntls == 0 ||
cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL),
("%s: fcntls without CAP_FCNTL", func));
KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 :
(fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0),
("%s: invalid ioctls", func));
KASSERT(fcaps->fc_nioctls == 0 ||
cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL),
("%s: ioctls without CAP_IOCTL", func));
}
static void
fdgrowtable_exp(struct filedesc *fdp, int nfd)
{
int nfd1, maxfd;
FILEDESC_XLOCK_ASSERT(fdp);
nfd1 = fdp->fd_nfiles * 2;
if (nfd1 < nfd)
nfd1 = nfd;
maxfd = getmaxfd(curproc);
if (maxfd < nfd1)
nfd1 = maxfd;
KASSERT(nfd <= nfd1,
("too low nfd1 %d %d %d %d", nfd, fdp->fd_nfiles, maxfd, nfd1));
fdgrowtable(fdp, nfd1);
}
/*
* Grow the file table to accomodate (at least) nfd descriptors.
*/
static void
fdgrowtable(struct filedesc *fdp, int nfd)
{
struct filedesc0 *fdp0;
struct freetable *ft;
struct filedescent *ntable;
struct filedescent *otable;
int nnfiles, onfiles;
NDSLOTTYPE *nmap, *omap;
FILEDESC_XLOCK_ASSERT(fdp);
KASSERT(fdp->fd_nfiles > 0, ("zero-length file table"));
/* save old values */
onfiles = fdp->fd_nfiles;
otable = fdp->fd_ofiles;
omap = fdp->fd_map;
/* compute the size of the new table */
nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */
if (nnfiles <= onfiles)
/* the table is already large enough */
return;
/*
* Allocate a new table and map. We need enough space for the
* file entries themselves and the struct freetable we will use
* when we decommission the table and place it on the freelist.
* We place the struct freetable in the middle so we don't have
* to worry about padding.
*/
ntable = malloc(nnfiles * sizeof(ntable[0]) + sizeof(struct freetable),
M_FILEDESC, M_ZERO | M_WAITOK);
nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC,
M_ZERO | M_WAITOK);
/* copy the old data over and point at the new tables */
memcpy(ntable, otable, onfiles * sizeof(*otable));
memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap));
/* update the pointers and counters */
memcpy(ntable, otable, onfiles * sizeof(ntable[0]));
fdp->fd_ofiles = ntable;
fdp->fd_map = nmap;
/*
* In order to have a valid pattern for fget_unlocked()
* fdp->fd_nfiles must be the last member to be updated, otherwise
* fget_unlocked() consumers may reference a new, higher value for
* fdp->fd_nfiles before to access the fdp->fd_ofiles array,
* resulting in OOB accesses.
*/
atomic_store_rel_int(&fdp->fd_nfiles, nnfiles);
/*
* Do not free the old file table, as some threads may still
* reference entries within it. Instead, place it on a freelist
* which will be processed when the struct filedesc is released.
*
* Do, however, free the old map.
*
* Note that if onfiles == NDFILE, we're dealing with the original
* static allocation contained within (struct filedesc0 *)fdp,
* which must not be freed.
*/
if (onfiles > NDFILE) {
ft = (struct freetable *)&otable[onfiles];
fdp0 = (struct filedesc0 *)fdp;
ft->ft_table = otable;
SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next);
free(omap, M_FILEDESC);
}
}
/*
* 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, allocfd;
#ifdef RACCT
int error;
#endif
FILEDESC_XLOCK_ASSERT(fdp);
if (fdp->fd_freefile > minfd)
minfd = fdp->fd_freefile;
maxfd = getmaxfd(p);
/*
* Search the bitmap for a free descriptor starting at minfd.
* If none is found, grow the file table.
*/
fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
if (fd >= maxfd)
return (EMFILE);
if (fd >= fdp->fd_nfiles) {
allocfd = min(fd * 2, maxfd);
#ifdef RACCT
PROC_LOCK(p);
error = racct_set(p, RACCT_NOFILE, allocfd);
PROC_UNLOCK(p);
if (error != 0)
return (EMFILE);
#endif
/*
* fd is already equal to first free descriptor >= minfd, so
* we only need to grow the table and we are done.
*/
fdgrowtable_exp(fdp, allocfd);
}
/*
* Perform some sanity checks, then mark the file descriptor as
* used and return it to the caller.
*/
KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles),
("invalid descriptor %d", fd));
KASSERT(!fdisused(fdp, fd),
("fd_first_free() returned non-free descriptor"));
KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
("file descriptor isn't free"));
KASSERT(fdp->fd_ofiles[fd].fde_flags == 0, ("file flags are set"));
fdused(fdp, fd);
*result = fd;
return (0);
}
/*
* Allocate n file descriptors for the process.
*/
int
fdallocn(struct thread *td, int minfd, int *fds, int n)
{
struct proc *p = td->td_proc;
struct filedesc *fdp = p->p_fd;
int i;
FILEDESC_XLOCK_ASSERT(fdp);
if (!fdavail(td, n))
return (EMFILE);
for (i = 0; i < n; i++)
if (fdalloc(td, 0, &fds[i]) != 0)
break;
if (i < n) {
for (i--; i >= 0; i--)
fdunused(fdp, fds[i]);
return (EMFILE);
}
return (0);
}
/*
* Check to see whether n user file descriptors are available to the process
* p.
*/
int
fdavail(struct thread *td, int n)
{
struct proc *p = td->td_proc;
struct filedesc *fdp = td->td_proc->p_fd;
int i, lim, last;
FILEDESC_LOCK_ASSERT(fdp);
/*
* XXX: This is only called from uipc_usrreq.c:unp_externalize();
* call racct_add() from there instead of dealing with containers
* here.
*/
lim = getmaxfd(p);
if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0)
return (1);
last = min(fdp->fd_nfiles, lim);
for (i = fdp->fd_freefile; i < last; i++) {
if (fdp->fd_ofiles[i].fde_file == 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 preempted and the entry in the descriptor table closed after we
* release the FILEDESC lock.
*/
int
falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags)
{
struct file *fp;
int error, fd;
error = falloc_noinstall(td, &fp);
if (error)
return (error); /* no reference held on error */
error = finstall(td, fp, &fd, flags, NULL);
if (error) {
fdrop(fp, td); /* one reference (fp only) */
return (error);
}
if (resultfp != NULL)
*resultfp = fp; /* copy out result */
else
fdrop(fp, td); /* release local reference */
if (resultfd != NULL)
*resultfd = fd;
return (0);
}
/*
* Create a new open file structure without allocating a file descriptor.
*/
int
falloc_noinstall(struct thread *td, struct file **resultfp)
{
struct file *fp;
int maxuserfiles = maxfiles - (maxfiles / 20);
static struct timeval lastfail;
static int curfail;
KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__));
if ((openfiles >= maxuserfiles &&
priv_check(td, PRIV_MAXFILES) != 0) ||
openfiles >= maxfiles) {
if (ppsratecheck(&lastfail, &curfail, 1)) {
printf("kern.maxfiles limit exceeded by uid %i, "
"please see tuning(7).\n", td->td_ucred->cr_ruid);
}
return (ENFILE);
}
atomic_add_int(&openfiles, 1);
fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO);
refcount_init(&fp->f_count, 1);
fp->f_cred = crhold(td->td_ucred);
fp->f_ops = &badfileops;
fp->f_data = NULL;
fp->f_vnode = NULL;
*resultfp = fp;
return (0);
}
/*
* Install a file in a file descriptor table.
*/
int
finstall(struct thread *td, struct file *fp, int *fd, int flags,
struct filecaps *fcaps)
{
struct filedesc *fdp = td->td_proc->p_fd;
struct filedescent *fde;
int error;
KASSERT(fd != NULL, ("%s: fd == NULL", __func__));
KASSERT(fp != NULL, ("%s: fp == NULL", __func__));
if (fcaps != NULL)
filecaps_validate(fcaps, __func__);
FILEDESC_XLOCK(fdp);
if ((error = fdalloc(td, 0, fd))) {
FILEDESC_XUNLOCK(fdp);
return (error);
}
fhold(fp);
fde = &fdp->fd_ofiles[*fd];
fde->fde_file = fp;
if ((flags & O_CLOEXEC) != 0)
fde->fde_flags |= UF_EXCLOSE;
if (fcaps != NULL)
filecaps_move(fcaps, &fde->fde_caps);
else
filecaps_fill(&fde->fde_caps);
FILEDESC_XUNLOCK(fdp);
return (0);
}
/*
* Build a new filedesc structure from another.
* Copy the current, root, and jail root vnode references.
*/
struct filedesc *
fdinit(struct filedesc *fdp)
{
struct filedesc0 *newfdp;
newfdp = malloc(sizeof *newfdp, M_FILEDESC, M_WAITOK | M_ZERO);
FILEDESC_LOCK_INIT(&newfdp->fd_fd);
if (fdp != NULL) {
FILEDESC_XLOCK(fdp);
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);
FILEDESC_XUNLOCK(fdp);
}
/* Create the file descriptor table. */
newfdp->fd_fd.fd_refcnt = 1;
newfdp->fd_fd.fd_holdcnt = 1;
newfdp->fd_fd.fd_cmask = CMASK;
newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles;
newfdp->fd_fd.fd_nfiles = NDFILE;
newfdp->fd_fd.fd_map = newfdp->fd_dmap;
newfdp->fd_fd.fd_lastfile = -1;
return (&newfdp->fd_fd);
}
static struct filedesc *
fdhold(struct proc *p)
{
struct filedesc *fdp;
mtx_lock(&fdesc_mtx);
fdp = p->p_fd;
if (fdp != NULL)
fdp->fd_holdcnt++;
mtx_unlock(&fdesc_mtx);
return (fdp);
}
static void
fddrop(struct filedesc *fdp)
{
struct filedesc0 *fdp0;
struct freetable *ft;
int i;
mtx_lock(&fdesc_mtx);
i = --fdp->fd_holdcnt;
mtx_unlock(&fdesc_mtx);
if (i > 0)
return;
FILEDESC_LOCK_DESTROY(fdp);
fdp0 = (struct filedesc0 *)fdp;
while ((ft = SLIST_FIRST(&fdp0->fd_free)) != NULL) {
SLIST_REMOVE_HEAD(&fdp0->fd_free, ft_next);
free(ft->ft_table, M_FILEDESC);
}
free(fdp, M_FILEDESC);
}
/*
* Share a filedesc structure.
*/
struct filedesc *
fdshare(struct filedesc *fdp)
{
FILEDESC_XLOCK(fdp);
fdp->fd_refcnt++;
FILEDESC_XUNLOCK(fdp);
return (fdp);
}
/*
* Unshare a filedesc structure, if necessary by making a copy
*/
void
fdunshare(struct proc *p, struct thread *td)
{
FILEDESC_XLOCK(p->p_fd);
if (p->p_fd->fd_refcnt > 1) {
struct filedesc *tmp;
FILEDESC_XUNLOCK(p->p_fd);
tmp = fdcopy(p->p_fd);
fdescfree(td);
p->p_fd = tmp;
} else
FILEDESC_XUNLOCK(p->p_fd);
}
/*
* Copy a filedesc structure. A NULL pointer in returns a NULL reference,
* this is to ease callers, not catch errors.
*/
struct filedesc *
fdcopy(struct filedesc *fdp)
{
struct filedesc *newfdp;
struct filedescent *nfde, *ofde;
int i;
/* Certain daemons might not have file descriptors. */
if (fdp == NULL)
return (NULL);
newfdp = fdinit(fdp);
FILEDESC_SLOCK(fdp);
while (fdp->fd_lastfile >= newfdp->fd_nfiles) {
FILEDESC_SUNLOCK(fdp);
FILEDESC_XLOCK(newfdp);
fdgrowtable(newfdp, fdp->fd_lastfile + 1);
FILEDESC_XUNLOCK(newfdp);
FILEDESC_SLOCK(fdp);
}
/* copy all passable descriptors (i.e. not kqueue) */
newfdp->fd_freefile = -1;
for (i = 0; i <= fdp->fd_lastfile; ++i) {
ofde = &fdp->fd_ofiles[i];
if (fdisused(fdp, i) &&
(ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) &&
ofde->fde_file->f_ops != &badfileops) {
nfde = &newfdp->fd_ofiles[i];
*nfde = *ofde;
filecaps_copy(&ofde->fde_caps, &nfde->fde_caps);
fhold(nfde->fde_file);
newfdp->fd_lastfile = i;
} else {
if (newfdp->fd_freefile == -1)
newfdp->fd_freefile = i;
}
}
newfdp->fd_cmask = fdp->fd_cmask;
FILEDESC_SUNLOCK(fdp);
FILEDESC_XLOCK(newfdp);
for (i = 0; i <= newfdp->fd_lastfile; ++i) {
if (newfdp->fd_ofiles[i].fde_file != NULL)
fdused(newfdp, i);
}
if (newfdp->fd_freefile == -1)
newfdp->fd_freefile = i;
FILEDESC_XUNLOCK(newfdp);
return (newfdp);
}
/*
* Release a filedesc structure.
*/
void
fdescfree(struct thread *td)
{
struct filedesc *fdp;
int i;
struct filedesc_to_leader *fdtol;
struct file *fp;
struct vnode *cdir, *jdir, *rdir, *vp;
struct flock lf;
/* Certain daemons might not have file descriptors. */
fdp = td->td_proc->p_fd;
if (fdp == NULL)
return;
#ifdef RACCT
PROC_LOCK(td->td_proc);
racct_set(td->td_proc, RACCT_NOFILE, 0);
PROC_UNLOCK(td->td_proc);
#endif
/* Check for special need to clear POSIX style locks */
fdtol = td->td_proc->p_fdtol;
if (fdtol != NULL) {
FILEDESC_XLOCK(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) {
for (i = 0; i <= fdp->fd_lastfile; i++) {
fp = fdp->fd_ofiles[i].fde_file;
if (fp == NULL || fp->f_type != DTYPE_VNODE)
continue;
fhold(fp);
FILEDESC_XUNLOCK(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_XLOCK(fdp);
fdrop(fp, td);
}
}
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;
sx_sleep(&fdp->fd_holdleaderscount,
FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0);
goto retry;
}
if (fdtol->fdl_holdcount > 0) {
/*
* Ensure that fdtol->fdl_leader remains
* valid in closef().
*/
fdtol->fdl_wakeup = 1;
sx_sleep(fdtol, FILEDESC_LOCK(fdp), 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_XUNLOCK(fdp);
if (fdtol != NULL)
free(fdtol, M_FILEDESC_TO_LEADER);
}
FILEDESC_XLOCK(fdp);
i = --fdp->fd_refcnt;
FILEDESC_XUNLOCK(fdp);
if (i > 0)
return;
for (i = 0; i <= fdp->fd_lastfile; i++) {
fp = fdp->fd_ofiles[i].fde_file;
if (fp != NULL) {
FILEDESC_XLOCK(fdp);
fdfree(fdp, i);
FILEDESC_XUNLOCK(fdp);
(void) closef(fp, td);
}
}
FILEDESC_XLOCK(fdp);
/* 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);
fdp->fd_nfiles = 0;
cdir = fdp->fd_cdir;
fdp->fd_cdir = NULL;
rdir = fdp->fd_rdir;
fdp->fd_rdir = NULL;
jdir = fdp->fd_jdir;
fdp->fd_jdir = NULL;
FILEDESC_XUNLOCK(fdp);
if (cdir != NULL)
vrele(cdir);
if (rdir != NULL)
vrele(rdir);
if (jdir != NULL)
vrele(jdir);
fddrop(fdp);
}
/*
* 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 check for 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(struct thread *td)
{
struct filedesc *fdp;
struct file *fp;
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_XLOCK(fdp);
for (i = 0; i <= fdp->fd_lastfile; i++) {
if (i > 2)
break;
fp = fdp->fd_ofiles[i].fde_file;
if (fp != NULL && is_unsafe(fp)) {
knote_fdclose(td, i);
/*
* NULL-out descriptor prior to close to avoid
* a race while close blocks.
*/
fdfree(fdp, i);
FILEDESC_XUNLOCK(fdp);
(void) closef(fp, td);
FILEDESC_XLOCK(fdp);
}
}
FILEDESC_XUNLOCK(fdp);
}
/*
* If a specific file object occupies a specific file descriptor, close the
* file descriptor entry and drop a reference on the file object. This is a
* convenience function to handle a subsequent error in a function that calls
* falloc() that handles the race that another thread might have closed the
* file descriptor out from under the thread creating the file object.
*/
void
fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td)
{
FILEDESC_XLOCK(fdp);
if (fdp->fd_ofiles[idx].fde_file == fp) {
fdfree(fdp, idx);
FILEDESC_XUNLOCK(fdp);
fdrop(fp, td);
} else
FILEDESC_XUNLOCK(fdp);
}
/*
* Close any files on exec?
*/
void
fdcloseexec(struct thread *td)
{
struct filedesc *fdp;
struct filedescent *fde;
struct file *fp;
int i;
/* Certain daemons might not have file descriptors. */
fdp = td->td_proc->p_fd;
if (fdp == NULL)
return;
/*
* We cannot cache fd_ofiles since operations
* may block and rip them out from under us.
*/
FILEDESC_XLOCK(fdp);
for (i = 0; i <= fdp->fd_lastfile; i++) {
fde = &fdp->fd_ofiles[i];
fp = fde->fde_file;
if (fp != NULL && (fp->f_type == DTYPE_MQUEUE ||
(fde->fde_flags & UF_EXCLOSE))) {
fdfree(fdp, i);
(void) closefp(fdp, i, fp, td, 0);
/* closefp() drops the FILEDESC lock. */
FILEDESC_XLOCK(fdp);
}
}
FILEDESC_XUNLOCK(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(struct thread *td)
{
struct filedesc *fdp;
register_t retval, save;
int i, error, 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].fde_file != NULL)
continue;
if (devnull < 0) {
save = td->td_retval[0];
error = kern_open(td, "/dev/null", UIO_SYSSPACE,
O_RDWR, 0);
devnull = td->td_retval[0];
td->td_retval[0] = save;
if (error)
break;
KASSERT(devnull == i, ("oof, we didn't get our fd"));
} 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.
*
* XXXRW: Giant is not required for the caller, but often will be held; this
* makes it moderately likely the Giant will be recursed in the VFS case.
*/
int
closef(struct file *fp, struct thread *td)
{
struct vnode *vp;
struct flock lf;
struct filedesc_to_leader *fdtol;
struct filedesc *fdp;
/*
* 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, and the thread pointer
* will be NULL. Callers should be careful only to pass a
* NULL thread pointer when there really is no owning
* context that might have locks, or the locks will be
* leaked.
*/
if (fp->f_type == DTYPE_VNODE && td != NULL) {
vp = fp->f_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;
(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_XLOCK(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_XUNLOCK(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_XLOCK(fdp);
fdtol->fdl_holdcount--;
if (fdtol->fdl_holdcount == 0 &&
fdtol->fdl_wakeup != 0) {
fdtol->fdl_wakeup = 0;
wakeup(fdtol);
}
}
FILEDESC_XUNLOCK(fdp);
}
}
return (fdrop(fp, td));
}
/*
* Initialize the file pointer with the specified properties.
*
* The ops are set with release semantics to be certain that the flags, type,
* and data are visible when ops is. This is to prevent ops methods from being
* called with bad data.
*/
void
finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops)
{
fp->f_data = data;
fp->f_flag = flag;
fp->f_type = type;
atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops);
}
int
fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
int needfcntl, struct file **fpp, cap_rights_t *haverightsp)
{
struct file *fp;
u_int count;
#ifdef CAPABILITIES
cap_rights_t haverights;
int error;
#endif
/*
* Avoid reads reordering and then a first access to the
* fdp->fd_ofiles table which could result in OOB operation.
*/
if (fd < 0 || fd >= atomic_load_acq_int(&fdp->fd_nfiles))
return (EBADF);
/*
* Fetch the descriptor locklessly. We avoid fdrop() races by
* never raising a refcount above 0. To accomplish this we have
* to use a cmpset loop rather than an atomic_add. The descriptor
* must be re-verified once we acquire a reference to be certain
* that the identity is still correct and we did not lose a race
* due to preemption.
*/
for (;;) {
fp = fdp->fd_ofiles[fd].fde_file;
if (fp == NULL)
return (EBADF);
#ifdef CAPABILITIES
haverights = *cap_rights(fdp, fd);
if (needrightsp != NULL) {
error = cap_check(&haverights, needrightsp);
if (error != 0)
return (error);
if (cap_rights_is_set(needrightsp, CAP_FCNTL)) {
error = cap_fcntl_check(fdp, fd, needfcntl);
if (error != 0)
return (error);
}
}
#endif
count = fp->f_count;
if (count == 0)
continue;
/*
* Use an acquire barrier to prevent caching of fd_ofiles
* so it is refreshed for verification.
*/
if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) != 1)
continue;
if (fp == fdp->fd_ofiles[fd].fde_file)
break;
fdrop(fp, curthread);
}
*fpp = fp;
if (haverightsp != NULL) {
#ifdef CAPABILITIES
*haverightsp = haverights;
#else
CAP_ALL(haverightsp);
#endif
}
return (0);
}
/*
* Extract the file pointer associated with the specified descriptor for the
* current user process.
*
* If the descriptor doesn't exist or doesn't match 'flags', EBADF is
* returned.
*
* File's rights will be checked against the capability rights mask.
*
* If an error occured the non-zero error is returned and *fpp is set to
* NULL. Otherwise *fpp is held and set and zero is returned. Caller is
* responsible for fdrop().
*/
static __inline int
_fget(struct thread *td, int fd, struct file **fpp, int flags,
cap_rights_t *needrightsp, u_char *maxprotp)
{
struct filedesc *fdp;
struct file *fp;
cap_rights_t haverights, needrights;
int error;
*fpp = NULL;
if (td == NULL || (fdp = td->td_proc->p_fd) == NULL)
return (EBADF);
if (needrightsp != NULL)
needrights = *needrightsp;
else
cap_rights_init(&needrights);
if (maxprotp != NULL)
cap_rights_set(&needrights, CAP_MMAP);
error = fget_unlocked(fdp, fd, &needrights, 0, &fp, &haverights);
if (error != 0)
return (error);
if (fp->f_ops == &badfileops) {
fdrop(fp, td);
return (EBADF);
}
#ifdef CAPABILITIES
/*
* If requested, convert capability rights to access flags.
*/
if (maxprotp != NULL)
*maxprotp = cap_rights_to_vmprot(&haverights);
#else /* !CAPABILITIES */
if (maxprotp != NULL)
*maxprotp = VM_PROT_ALL;
#endif /* CAPABILITIES */
/*
* FREAD and FWRITE failure return EBADF as per POSIX.
*/
error = 0;
switch (flags) {
case FREAD:
case FWRITE:
if ((fp->f_flag & flags) == 0)
error = EBADF;
break;
case FEXEC:
if ((fp->f_flag & (FREAD | FEXEC)) == 0 ||
((fp->f_flag & FWRITE) != 0))
error = EBADF;
break;
case 0:
break;
default:
KASSERT(0, ("wrong flags"));
}
if (error != 0) {
fdrop(fp, td);
return (error);
}
*fpp = fp;
return (0);
}
int
fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
{
return(_fget(td, fd, fpp, 0, rightsp, NULL));
}
int
fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp,
struct file **fpp)
{
return (_fget(td, fd, fpp, 0, rightsp, maxprotp));
}
int
fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
{
return(_fget(td, fd, fpp, FREAD, rightsp, NULL));
}
int
fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
{
return (_fget(td, fd, fpp, FWRITE, rightsp, NULL));
}
/*
* 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. The returned vnode will be vref()'d.
*
* XXX: what about the unused flags ?
*/
static __inline int
_fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp,
struct vnode **vpp)
{
struct file *fp;
int error;
*vpp = NULL;
error = _fget(td, fd, &fp, flags, needrightsp, NULL);
if (error != 0)
return (error);
if (fp->f_vnode == NULL) {
error = EINVAL;
} else {
*vpp = fp->f_vnode;
vref(*vpp);
}
fdrop(fp, td);
return (error);
}
int
fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
{
return (_fgetvp(td, fd, 0, rightsp, vpp));
}
int
fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp,
struct filecaps *havecaps, struct vnode **vpp)
{
struct filedesc *fdp;
struct file *fp;
#ifdef CAPABILITIES
int error;
#endif
if (td == NULL || (fdp = td->td_proc->p_fd) == NULL)
return (EBADF);
fp = fget_locked(fdp, fd);
if (fp == NULL || fp->f_ops == &badfileops)
return (EBADF);
#ifdef CAPABILITIES
if (needrightsp != NULL) {
error = cap_check(cap_rights(fdp, fd), needrightsp);
if (error != 0)
return (error);
}
#endif
if (fp->f_vnode == NULL)
return (EINVAL);
*vpp = fp->f_vnode;
vref(*vpp);
filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecaps);
return (0);
}
int
fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
{
return (_fgetvp(td, fd, FREAD, rightsp, vpp));
}
int
fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
{
return (_fgetvp(td, fd, FEXEC, rightsp, vpp));
}
#ifdef notyet
int
fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp,
struct vnode **vpp)
{
return (_fgetvp(td, fd, FWRITE, rightsp, vpp));
}
#endif
/*
* 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.
*
* Note: fgetsock() and fputsock() are deprecated, as consumers should rely
* on their file descriptor reference to prevent the socket from being free'd
* during use.
*/
int
fgetsock(struct thread *td, int fd, cap_rights_t *rightsp, 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, rightsp, NULL)) != 0)
return (error);
if (fp->f_type != DTYPE_SOCKET) {
error = ENOTSOCK;
} else {
*spp = fp->f_data;
if (fflagp)
*fflagp = fp->f_flag;
SOCK_LOCK(*spp);
soref(*spp);
SOCK_UNLOCK(*spp);
}
fdrop(fp, td);
return (error);
}
/*
* Drop the reference count on the socket and XXX release the SX lock in the
* future. The last reference closes the socket.
*
* Note: fputsock() is deprecated, see comment for fgetsock().
*/
void
fputsock(struct socket *so)
{
ACCEPT_LOCK();
SOCK_LOCK(so);
CURVNET_SET(so->so_vnet);
sorele(so);
CURVNET_RESTORE();
}
/*
* Handle the last reference to a file being closed.
*/
int
_fdrop(struct file *fp, struct thread *td)
{
int error;
error = 0;
if (fp->f_count != 0)
panic("fdrop: count %d", fp->f_count);
if (fp->f_ops != &badfileops)
error = fo_close(fp, td);
atomic_subtract_int(&openfiles, 1);
crfree(fp->f_cred);
free(fp->f_advice, M_FADVISE);
uma_zfree(file_zone, 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).
*/
#ifndef _SYS_SYSPROTO_H_
struct flock_args {
int fd;
int how;
};
#endif
/* ARGSUSED */
int
sys_flock(struct thread *td, struct flock_args *uap)
{
struct file *fp;
struct vnode *vp;
struct flock lf;
cap_rights_t rights;
int error;
error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp);
if (error != 0)
return (error);
if (fp->f_type != DTYPE_VNODE) {
fdrop(fp, td);
return (EOPNOTSUPP);
}
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;
atomic_clear_int(&fp->f_flag, FHASLOCK);
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;
}
atomic_set_int(&fp->f_flag, FHASLOCK);
error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
(uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
done2:
fdrop(fp, td);
return (error);
}
/*
* Duplicate the specified descriptor to a free descriptor.
*/
int
dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode,
int openerror, int *indxp)
{
struct file *fp;
int error, indx;
KASSERT(openerror == ENODEV || openerror == ENXIO,
("unexpected error %d in %s", openerror, __func__));
/*
* 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_XLOCK(fdp);
if ((fp = fget_locked(fdp, dfd)) == NULL) {
FILEDESC_XUNLOCK(fdp);
return (EBADF);
}
error = fdalloc(td, 0, &indx);
if (error != 0) {
FILEDESC_XUNLOCK(fdp);
return (error);
}
/*
* 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.
*/
switch (openerror) {
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)) | fp->f_flag) != fp->f_flag) {
fdunused(fdp, indx);
FILEDESC_XUNLOCK(fdp);
return (EACCES);
}
fhold(fp);
fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd];
filecaps_copy(&fdp->fd_ofiles[dfd].fde_caps,
&fdp->fd_ofiles[indx].fde_caps);
break;
case ENXIO:
/*
* Steal away the file pointer from dfd and stuff it into indx.
*/
fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd];
bzero(&fdp->fd_ofiles[dfd], sizeof(fdp->fd_ofiles[dfd]));
fdunused(fdp, dfd);
break;
}
FILEDESC_XUNLOCK(fdp);
*indxp = indx;
return (0);
}
/*
* Scan all active processes and prisons to see if any of them have a current
* or root directory of `olddp'. If so, replace them with the new mount point.
*/
void
mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
{
struct filedesc *fdp;
struct prison *pr;
struct proc *p;
int nrele;
if (vrefcnt(olddp) == 1)
return;
nrele = 0;
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
fdp = fdhold(p);
if (fdp == NULL)
continue;
FILEDESC_XLOCK(fdp);
if (fdp->fd_cdir == olddp) {
vref(newdp);
fdp->fd_cdir = newdp;
nrele++;
}
if (fdp->fd_rdir == olddp) {
vref(newdp);
fdp->fd_rdir = newdp;
nrele++;
}
if (fdp->fd_jdir == olddp) {
vref(newdp);
fdp->fd_jdir = newdp;
nrele++;
}
FILEDESC_XUNLOCK(fdp);
fddrop(fdp);
}
sx_sunlock(&allproc_lock);
if (rootvnode == olddp) {
vref(newdp);
rootvnode = newdp;
nrele++;
}
mtx_lock(&prison0.pr_mtx);
if (prison0.pr_root == olddp) {
vref(newdp);
prison0.pr_root = newdp;
nrele++;
}
mtx_unlock(&prison0.pr_mtx);
sx_slock(&allprison_lock);
TAILQ_FOREACH(pr, &allprison, pr_list) {
mtx_lock(&pr->pr_mtx);
if (pr->pr_root == olddp) {
vref(newdp);
pr->pr_root = newdp;
nrele++;
}
mtx_unlock(&pr->pr_mtx);
}
sx_sunlock(&allprison_lock);
while (nrele--)
vrele(olddp);
}
struct filedesc_to_leader *
filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader)
{
struct filedesc_to_leader *fdtol;
fdtol = malloc(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_XLOCK(fdp);
fdtol->fdl_next = old->fdl_next;
fdtol->fdl_prev = old;
old->fdl_next = fdtol;
fdtol->fdl_next->fdl_prev = fdtol;
FILEDESC_XUNLOCK(fdp);
} else {
fdtol->fdl_next = fdtol;
fdtol->fdl_prev = fdtol;
}
return (fdtol);
}
/*
* Get file structures globally.
*/
static int
sysctl_kern_file(SYSCTL_HANDLER_ARGS)
{
struct xfile xf;
struct filedesc *fdp;
struct file *fp;
struct proc *p;
int error, n;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
if (req->oldptr == NULL) {
n = 0;
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
if (p->p_state == PRS_NEW)
continue;
fdp = fdhold(p);
if (fdp == NULL)
continue;
/* overestimates sparse tables. */
if (fdp->fd_lastfile > 0)
n += fdp->fd_lastfile;
fddrop(fdp);
}
sx_sunlock(&allproc_lock);
return (SYSCTL_OUT(req, 0, n * sizeof(xf)));
}
error = 0;
bzero(&xf, sizeof(xf));
xf.xf_size = sizeof(xf);
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
PROC_LOCK(p);
if (p->p_state == PRS_NEW) {
PROC_UNLOCK(p);
continue;
}
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);
fdp = fdhold(p);
if (fdp == NULL)
continue;
FILEDESC_SLOCK(fdp);
for (n = 0; fdp->fd_refcnt > 0 && n < fdp->fd_nfiles; ++n) {
if ((fp = fdp->fd_ofiles[n].fde_file) == NULL)
continue;
xf.xf_fd = n;
xf.xf_file = fp;
xf.xf_data = fp->f_data;
xf.xf_vnode = fp->f_vnode;
xf.xf_type = fp->f_type;
xf.xf_count = fp->f_count;
xf.xf_msgcount = 0;
xf.xf_offset = foffset_get(fp);
xf.xf_flag = fp->f_flag;
error = SYSCTL_OUT(req, &xf, sizeof(xf));
if (error)
break;
}
FILEDESC_SUNLOCK(fdp);
fddrop(fdp);
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");
#ifdef KINFO_OFILE_SIZE
CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE);
#endif
#ifdef COMPAT_FREEBSD7
static int
export_vnode_for_osysctl(struct vnode *vp, int type,
struct kinfo_ofile *kif, struct filedesc *fdp, struct sysctl_req *req)
{
int error;
char *fullpath, *freepath;
bzero(kif, sizeof(*kif));
kif->kf_structsize = sizeof(*kif);
vref(vp);
kif->kf_fd = type;
kif->kf_type = KF_TYPE_VNODE;
/* This function only handles directories. */
if (vp->v_type != VDIR) {
vrele(vp);
return (ENOTDIR);
}
kif->kf_vnode_type = KF_VTYPE_VDIR;
/*
* This is not a true file descriptor, so we set a bogus refcount
* and offset to indicate these fields should be ignored.
*/
kif->kf_ref_count = -1;
kif->kf_offset = -1;
freepath = NULL;
fullpath = "-";
FILEDESC_SUNLOCK(fdp);
vn_fullpath(curthread, vp, &fullpath, &freepath);
vrele(vp);
strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
if (freepath != NULL)
free(freepath, M_TEMP);
error = SYSCTL_OUT(req, kif, sizeof(*kif));
FILEDESC_SLOCK(fdp);
return (error);
}
/*
* Get per-process file descriptors for use by procstat(1), et al.
*/
static int
sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
{
char *fullpath, *freepath;
struct kinfo_ofile *kif;
struct filedesc *fdp;
int error, i, *name;
struct shmfd *shmfd;
struct socket *so;
struct vnode *vp;
struct ksem *ks;
struct file *fp;
struct proc *p;
struct tty *tp;
name = (int *)arg1;
error = pget((pid_t)name[0], PGET_CANDEBUG, &p);
if (error != 0)
return (error);
fdp = fdhold(p);
PROC_UNLOCK(p);
if (fdp == NULL)
return (ENOENT);
kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
FILEDESC_SLOCK(fdp);
if (fdp->fd_cdir != NULL)
export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif,
fdp, req);
if (fdp->fd_rdir != NULL)
export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif,
fdp, req);
if (fdp->fd_jdir != NULL)
export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif,
fdp, req);
for (i = 0; i < fdp->fd_nfiles; i++) {
if ((fp = fdp->fd_ofiles[i].fde_file) == NULL)
continue;
bzero(kif, sizeof(*kif));
kif->kf_structsize = sizeof(*kif);
ks = NULL;
vp = NULL;
so = NULL;
tp = NULL;
shmfd = NULL;
kif->kf_fd = i;
switch (fp->f_type) {
case DTYPE_VNODE:
kif->kf_type = KF_TYPE_VNODE;
vp = fp->f_vnode;
break;
case DTYPE_SOCKET:
kif->kf_type = KF_TYPE_SOCKET;
so = fp->f_data;
break;
case DTYPE_PIPE:
kif->kf_type = KF_TYPE_PIPE;
break;
case DTYPE_FIFO:
kif->kf_type = KF_TYPE_FIFO;
vp = fp->f_vnode;
break;
case DTYPE_KQUEUE:
kif->kf_type = KF_TYPE_KQUEUE;
break;
case DTYPE_CRYPTO:
kif->kf_type = KF_TYPE_CRYPTO;
break;
case DTYPE_MQUEUE:
kif->kf_type = KF_TYPE_MQUEUE;
break;
case DTYPE_SHM:
kif->kf_type = KF_TYPE_SHM;
shmfd = fp->f_data;
break;
case DTYPE_SEM:
kif->kf_type = KF_TYPE_SEM;
ks = fp->f_data;
break;
case DTYPE_PTS:
kif->kf_type = KF_TYPE_PTS;
tp = fp->f_data;
break;
#ifdef PROCDESC
case DTYPE_PROCDESC:
kif->kf_type = KF_TYPE_PROCDESC;
break;
#endif
default:
kif->kf_type = KF_TYPE_UNKNOWN;
break;
}
kif->kf_ref_count = fp->f_count;
if (fp->f_flag & FREAD)
kif->kf_flags |= KF_FLAG_READ;
if (fp->f_flag & FWRITE)
kif->kf_flags |= KF_FLAG_WRITE;
if (fp->f_flag & FAPPEND)
kif->kf_flags |= KF_FLAG_APPEND;
if (fp->f_flag & FASYNC)
kif->kf_flags |= KF_FLAG_ASYNC;
if (fp->f_flag & FFSYNC)
kif->kf_flags |= KF_FLAG_FSYNC;
if (fp->f_flag & FNONBLOCK)
kif->kf_flags |= KF_FLAG_NONBLOCK;
if (fp->f_flag & O_DIRECT)
kif->kf_flags |= KF_FLAG_DIRECT;
if (fp->f_flag & FHASLOCK)
kif->kf_flags |= KF_FLAG_HASLOCK;
kif->kf_offset = foffset_get(fp);
if (vp != NULL) {
vref(vp);
switch (vp->v_type) {
case VNON:
kif->kf_vnode_type = KF_VTYPE_VNON;
break;
case VREG:
kif->kf_vnode_type = KF_VTYPE_VREG;
break;
case VDIR:
kif->kf_vnode_type = KF_VTYPE_VDIR;
break;
case VBLK:
kif->kf_vnode_type = KF_VTYPE_VBLK;
break;
case VCHR:
kif->kf_vnode_type = KF_VTYPE_VCHR;
break;
case VLNK:
kif->kf_vnode_type = KF_VTYPE_VLNK;
break;
case VSOCK:
kif->kf_vnode_type = KF_VTYPE_VSOCK;
break;
case VFIFO:
kif->kf_vnode_type = KF_VTYPE_VFIFO;
break;
case VBAD:
kif->kf_vnode_type = KF_VTYPE_VBAD;
break;
default:
kif->kf_vnode_type = KF_VTYPE_UNKNOWN;
break;
}
/*
* It is OK to drop the filedesc lock here as we will
* re-validate and re-evaluate its properties when
* the loop continues.
*/
freepath = NULL;
fullpath = "-";
FILEDESC_SUNLOCK(fdp);
vn_fullpath(curthread, vp, &fullpath, &freepath);
vrele(vp);
strlcpy(kif->kf_path, fullpath,
sizeof(kif->kf_path));
if (freepath != NULL)
free(freepath, M_TEMP);
FILEDESC_SLOCK(fdp);
}
if (so != NULL) {
struct sockaddr *sa;
if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa)
== 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) {
bcopy(sa, &kif->kf_sa_local, sa->sa_len);
free(sa, M_SONAME);
}
if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa)
== 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) {
bcopy(sa, &kif->kf_sa_peer, sa->sa_len);
free(sa, M_SONAME);
}
kif->kf_sock_domain =
so->so_proto->pr_domain->dom_family;
kif->kf_sock_type = so->so_type;
kif->kf_sock_protocol = so->so_proto->pr_protocol;
}
if (tp != NULL) {
strlcpy(kif->kf_path, tty_devname(tp),
sizeof(kif->kf_path));
}
if (shmfd != NULL)
shm_path(shmfd, kif->kf_path, sizeof(kif->kf_path));
if (ks != NULL && ksem_info != NULL)
ksem_info(ks, kif->kf_path, sizeof(kif->kf_path), NULL);
error = SYSCTL_OUT(req, kif, sizeof(*kif));
if (error)
break;
}
FILEDESC_SUNLOCK(fdp);
fddrop(fdp);
free(kif, M_TEMP);
return (0);
}
static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, CTLFLAG_RD,
sysctl_kern_proc_ofiledesc, "Process ofiledesc entries");
#endif /* COMPAT_FREEBSD7 */
#ifdef KINFO_FILE_SIZE
CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
#endif
struct export_fd_buf {
struct filedesc *fdp;
struct sbuf *sb;
ssize_t remainder;
struct kinfo_file kif;
};
static int
export_fd_to_sb(void *data, int type, int fd, int fflags, int refcnt,
int64_t offset, cap_rights_t *rightsp, struct export_fd_buf *efbuf)
{
struct {
int fflag;
int kf_fflag;
} fflags_table[] = {
{ FAPPEND, KF_FLAG_APPEND },
{ FASYNC, KF_FLAG_ASYNC },
{ FFSYNC, KF_FLAG_FSYNC },
{ FHASLOCK, KF_FLAG_HASLOCK },
{ FNONBLOCK, KF_FLAG_NONBLOCK },
{ FREAD, KF_FLAG_READ },
{ FWRITE, KF_FLAG_WRITE },
{ O_CREAT, KF_FLAG_CREAT },
{ O_DIRECT, KF_FLAG_DIRECT },
{ O_EXCL, KF_FLAG_EXCL },
{ O_EXEC, KF_FLAG_EXEC },
{ O_EXLOCK, KF_FLAG_EXLOCK },
{ O_NOFOLLOW, KF_FLAG_NOFOLLOW },
{ O_SHLOCK, KF_FLAG_SHLOCK },
{ O_TRUNC, KF_FLAG_TRUNC }
};
#define NFFLAGS (sizeof(fflags_table) / sizeof(*fflags_table))
struct kinfo_file *kif;
struct vnode *vp;
int error, locked;
unsigned int i;
if (efbuf->remainder == 0)
return (0);
kif = &efbuf->kif;
bzero(kif, sizeof(*kif));
locked = efbuf->fdp != NULL;
switch (type) {
case KF_TYPE_FIFO:
case KF_TYPE_VNODE:
if (locked) {
FILEDESC_SUNLOCK(efbuf->fdp);
locked = 0;
}
vp = (struct vnode *)data;
error = fill_vnode_info(vp, kif);
vrele(vp);
break;
case KF_TYPE_SOCKET:
error = fill_socket_info((struct socket *)data, kif);
break;
case KF_TYPE_PIPE:
error = fill_pipe_info((struct pipe *)data, kif);
break;
case KF_TYPE_PTS:
error = fill_pts_info((struct tty *)data, kif);
break;
case KF_TYPE_PROCDESC:
error = fill_procdesc_info((struct procdesc *)data, kif);
break;
case KF_TYPE_SEM:
error = fill_sem_info((struct file *)data, kif);
break;
case KF_TYPE_SHM:
error = fill_shm_info((struct file *)data, kif);
break;
default:
error = 0;
}
if (error == 0)
kif->kf_status |= KF_ATTR_VALID;
/*
* Translate file access flags.
*/
for (i = 0; i < NFFLAGS; i++)
if (fflags & fflags_table[i].fflag)
kif->kf_flags |= fflags_table[i].kf_fflag;
if (rightsp != NULL)
kif->kf_cap_rights = *rightsp;
else
cap_rights_init(&kif->kf_cap_rights);
kif->kf_fd = fd;
kif->kf_type = type;
kif->kf_ref_count = refcnt;
kif->kf_offset = offset;
/* Pack record size down */
kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
strlen(kif->kf_path) + 1;
kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t));
if (efbuf->remainder != -1) {
if (efbuf->remainder < kif->kf_structsize) {
/* Terminate export. */
efbuf->remainder = 0;
if (efbuf->fdp != NULL && !locked)
FILEDESC_SLOCK(efbuf->fdp);
return (0);
}
efbuf->remainder -= kif->kf_structsize;
}
if (locked)
FILEDESC_SUNLOCK(efbuf->fdp);
error = sbuf_bcat(efbuf->sb, kif, kif->kf_structsize);
if (efbuf->fdp != NULL)
FILEDESC_SLOCK(efbuf->fdp);
return (error);
}
/*
* Store a process file descriptor information to sbuf.
*
* Takes a locked proc as argument, and returns with the proc unlocked.
*/
int
kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen)
{
struct file *fp;
struct filedesc *fdp;
struct export_fd_buf *efbuf;
struct vnode *cttyvp, *textvp, *tracevp;
int64_t offset;
void *data;
int error, i;
int type, refcnt, fflags;
cap_rights_t rights;
PROC_LOCK_ASSERT(p, MA_OWNED);
/* ktrace vnode */
tracevp = p->p_tracevp;
if (tracevp != NULL)
vref(tracevp);
/* text vnode */
textvp = p->p_textvp;
if (textvp != NULL)
vref(textvp);
/* Controlling tty. */
cttyvp = NULL;
if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) {
cttyvp = p->p_pgrp->pg_session->s_ttyvp;
if (cttyvp != NULL)
vref(cttyvp);
}
fdp = fdhold(p);
PROC_UNLOCK(p);
efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
efbuf->fdp = NULL;
efbuf->sb = sb;
efbuf->remainder = maxlen;
if (tracevp != NULL)
export_fd_to_sb(tracevp, KF_TYPE_VNODE, KF_FD_TYPE_TRACE,
FREAD | FWRITE, -1, -1, NULL, efbuf);
if (textvp != NULL)
export_fd_to_sb(textvp, KF_TYPE_VNODE, KF_FD_TYPE_TEXT,
FREAD, -1, -1, NULL, efbuf);
if (cttyvp != NULL)
export_fd_to_sb(cttyvp, KF_TYPE_VNODE, KF_FD_TYPE_CTTY,
FREAD | FWRITE, -1, -1, NULL, efbuf);
error = 0;
if (fdp == NULL)
goto fail;
efbuf->fdp = fdp;
FILEDESC_SLOCK(fdp);
/* working directory */
if (fdp->fd_cdir != NULL) {
vref(fdp->fd_cdir);
data = fdp->fd_cdir;
export_fd_to_sb(data, KF_TYPE_VNODE, KF_FD_TYPE_CWD,
FREAD, -1, -1, NULL, efbuf);
}
/* root directory */
if (fdp->fd_rdir != NULL) {
vref(fdp->fd_rdir);
data = fdp->fd_rdir;
export_fd_to_sb(data, KF_TYPE_VNODE, KF_FD_TYPE_ROOT,
FREAD, -1, -1, NULL, efbuf);
}
/* jail directory */
if (fdp->fd_jdir != NULL) {
vref(fdp->fd_jdir);
data = fdp->fd_jdir;
export_fd_to_sb(data, KF_TYPE_VNODE, KF_FD_TYPE_JAIL,
FREAD, -1, -1, NULL, efbuf);
}
for (i = 0; i < fdp->fd_nfiles; i++) {
if ((fp = fdp->fd_ofiles[i].fde_file) == NULL)
continue;
data = NULL;
#ifdef CAPABILITIES
rights = *cap_rights(fdp, i);
#else /* !CAPABILITIES */
cap_rights_init(&rights);
#endif
switch (fp->f_type) {
case DTYPE_VNODE:
type = KF_TYPE_VNODE;
vref(fp->f_vnode);
data = fp->f_vnode;
break;
case DTYPE_SOCKET:
type = KF_TYPE_SOCKET;
data = fp->f_data;
break;
case DTYPE_PIPE:
type = KF_TYPE_PIPE;
data = fp->f_data;
break;
case DTYPE_FIFO:
type = KF_TYPE_FIFO;
vref(fp->f_vnode);
data = fp->f_vnode;
break;
case DTYPE_KQUEUE:
type = KF_TYPE_KQUEUE;
break;
case DTYPE_CRYPTO:
type = KF_TYPE_CRYPTO;
break;
case DTYPE_MQUEUE:
type = KF_TYPE_MQUEUE;
break;
case DTYPE_SHM:
type = KF_TYPE_SHM;
data = fp;
break;
case DTYPE_SEM:
type = KF_TYPE_SEM;
data = fp;
break;
case DTYPE_PTS:
type = KF_TYPE_PTS;
data = fp->f_data;
break;
#ifdef PROCDESC
case DTYPE_PROCDESC:
type = KF_TYPE_PROCDESC;
data = fp->f_data;
break;
#endif
default:
type = KF_TYPE_UNKNOWN;
break;
}
refcnt = fp->f_count;
fflags = fp->f_flag;
offset = foffset_get(fp);
/*
* Create sysctl entry.
* It is OK to drop the filedesc lock here as we will
* re-validate and re-evaluate its properties when
* the loop continues.
*/
error = export_fd_to_sb(data, type, i, fflags, refcnt,
offset, &rights, efbuf);
if (error != 0)
break;
}
FILEDESC_SUNLOCK(fdp);
fddrop(fdp);
fail:
free(efbuf, M_TEMP);
return (error);
}
#define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5)
/*
* Get per-process file descriptors for use by procstat(1), et al.
*/
static int
sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)
{
struct sbuf sb;
struct proc *p;
ssize_t maxlen;
int error, error2, *name;
name = (int *)arg1;
sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req);
error = pget((pid_t)name[0], PGET_CANDEBUG, &p);
if (error != 0) {
sbuf_delete(&sb);
return (error);
}
maxlen = req->oldptr != NULL ? req->oldlen : -1;
error = kern_proc_filedesc_out(p, &sb, maxlen);
error2 = sbuf_finish(&sb);
sbuf_delete(&sb);
return (error != 0 ? error : error2);
}
int
vntype_to_kinfo(int vtype)
{
struct {
int vtype;
int kf_vtype;
} vtypes_table[] = {
{ VBAD, KF_VTYPE_VBAD },
{ VBLK, KF_VTYPE_VBLK },
{ VCHR, KF_VTYPE_VCHR },
{ VDIR, KF_VTYPE_VDIR },
{ VFIFO, KF_VTYPE_VFIFO },
{ VLNK, KF_VTYPE_VLNK },
{ VNON, KF_VTYPE_VNON },
{ VREG, KF_VTYPE_VREG },
{ VSOCK, KF_VTYPE_VSOCK }
};
#define NVTYPES (sizeof(vtypes_table) / sizeof(*vtypes_table))
unsigned int i;
/*
* Perform vtype translation.
*/
for (i = 0; i < NVTYPES; i++)
if (vtypes_table[i].vtype == vtype)
break;
if (i < NVTYPES)
return (vtypes_table[i].kf_vtype);
return (KF_VTYPE_UNKNOWN);
}
static int
fill_vnode_info(struct vnode *vp, struct kinfo_file *kif)
{
struct vattr va;
char *fullpath, *freepath;
int error;
if (vp == NULL)
return (1);
kif->kf_vnode_type = vntype_to_kinfo(vp->v_type);
freepath = NULL;
fullpath = "-";
error = vn_fullpath(curthread, vp, &fullpath, &freepath);
if (error == 0) {
strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
}
if (freepath != NULL)
free(freepath, M_TEMP);
/*
* Retrieve vnode attributes.
*/
va.va_fsid = VNOVAL;
va.va_rdev = NODEV;
vn_lock(vp, LK_SHARED | LK_RETRY);
error = VOP_GETATTR(vp, &va, curthread->td_ucred);
VOP_UNLOCK(vp, 0);
if (error != 0)
return (error);
if (va.va_fsid != VNOVAL)
kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
else
kif->kf_un.kf_file.kf_file_fsid =
vp->v_mount->mnt_stat.f_fsid.val[0];
kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
kif->kf_un.kf_file.kf_file_size = va.va_size;
kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
return (0);
}
static int
fill_socket_info(struct socket *so, struct kinfo_file *kif)
{
struct sockaddr *sa;
struct inpcb *inpcb;
struct unpcb *unpcb;
int error;
if (so == NULL)
return (1);
kif->kf_sock_domain = so->so_proto->pr_domain->dom_family;
kif->kf_sock_type = so->so_type;
kif->kf_sock_protocol = so->so_proto->pr_protocol;
kif->kf_un.kf_sock.kf_sock_pcb = (uintptr_t)so->so_pcb;
switch(kif->kf_sock_domain) {
case AF_INET:
case AF_INET6:
if (kif->kf_sock_protocol == IPPROTO_TCP) {
if (so->so_pcb != NULL) {
inpcb = (struct inpcb *)(so->so_pcb);
kif->kf_un.kf_sock.kf_sock_inpcb =
(uintptr_t)inpcb->inp_ppcb;
}
}
break;
case AF_UNIX:
if (so->so_pcb != NULL) {
unpcb = (struct unpcb *)(so->so_pcb);
if (unpcb->unp_conn) {
kif->kf_un.kf_sock.kf_sock_unpconn =
(uintptr_t)unpcb->unp_conn;
kif->kf_un.kf_sock.kf_sock_rcv_sb_state =
so->so_rcv.sb_state;
kif->kf_un.kf_sock.kf_sock_snd_sb_state =
so->so_snd.sb_state;
}
}
break;
}
error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
if (error == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) {
bcopy(sa, &kif->kf_sa_local, sa->sa_len);
free(sa, M_SONAME);
}
error = so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa);
if (error == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) {
bcopy(sa, &kif->kf_sa_peer, sa->sa_len);
free(sa, M_SONAME);
}
strncpy(kif->kf_path, so->so_proto->pr_domain->dom_name,
sizeof(kif->kf_path));
return (0);
}
static int
fill_pts_info(struct tty *tp, struct kinfo_file *kif)
{
if (tp == NULL)
return (1);
kif->kf_un.kf_pts.kf_pts_dev = tty_udev(tp);
strlcpy(kif->kf_path, tty_devname(tp), sizeof(kif->kf_path));
return (0);
}
static int
fill_pipe_info(struct pipe *pi, struct kinfo_file *kif)
{
if (pi == NULL)
return (1);
kif->kf_un.kf_pipe.kf_pipe_addr = (uintptr_t)pi;
kif->kf_un.kf_pipe.kf_pipe_peer = (uintptr_t)pi->pipe_peer;
kif->kf_un.kf_pipe.kf_pipe_buffer_cnt = pi->pipe_buffer.cnt;
return (0);
}
static int
fill_procdesc_info(struct procdesc *pdp, struct kinfo_file *kif)
{
if (pdp == NULL)
return (1);
kif->kf_un.kf_proc.kf_pid = pdp->pd_pid;
return (0);
}
static int
fill_sem_info(struct file *fp, struct kinfo_file *kif)
{
struct thread *td;
struct stat sb;
td = curthread;
if (fp->f_data == NULL)
return (1);
if (fo_stat(fp, &sb, td->td_ucred, td) != 0)
return (1);
if (ksem_info == NULL)
return (1);
ksem_info(fp->f_data, kif->kf_path, sizeof(kif->kf_path),
&kif->kf_un.kf_sem.kf_sem_value);
kif->kf_un.kf_sem.kf_sem_mode = sb.st_mode;
return (0);
}
static int
fill_shm_info(struct file *fp, struct kinfo_file *kif)
{
struct thread *td;
struct stat sb;
td = curthread;
if (fp->f_data == NULL)
return (1);
if (fo_stat(fp, &sb, td->td_ucred, td) != 0)
return (1);
shm_path(fp->f_data, kif->kf_path, sizeof(kif->kf_path));
kif->kf_un.kf_file.kf_file_mode = sb.st_mode;
kif->kf_un.kf_file.kf_file_size = sb.st_size;
return (0);
}
static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD,
sysctl_kern_proc_filedesc, "Process filedesc entries");
#ifdef DDB
/*
* For the purposes of debugging, generate a human-readable string for the
* file type.
*/
static const char *
file_type_to_name(short type)
{
switch (type) {
case 0:
return ("zero");
case DTYPE_VNODE:
return ("vnod");
case DTYPE_SOCKET:
return ("sock");
case DTYPE_PIPE:
return ("pipe");
case DTYPE_FIFO:
return ("fifo");
case DTYPE_KQUEUE:
return ("kque");
case DTYPE_CRYPTO:
return ("crpt");
case DTYPE_MQUEUE:
return ("mque");
case DTYPE_SHM:
return ("shm");
case DTYPE_SEM:
return ("ksem");
default:
return ("unkn");
}
}
/*
* For the purposes of debugging, identify a process (if any, perhaps one of
* many) that references the passed file in its file descriptor array. Return
* NULL if none.
*/
static struct proc *
file_to_first_proc(struct file *fp)
{
struct filedesc *fdp;
struct proc *p;
int n;
FOREACH_PROC_IN_SYSTEM(p) {
if (p->p_state == PRS_NEW)
continue;
fdp = p->p_fd;
if (fdp == NULL)
continue;
for (n = 0; n < fdp->fd_nfiles; n++) {
if (fp == fdp->fd_ofiles[n].fde_file)
return (p);
}
}
return (NULL);
}
static void
db_print_file(struct file *fp, int header)
{
struct proc *p;
if (header)
db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n",
"File", "Type", "Data", "Flag", "GCFl", "Count",
"MCount", "Vnode", "FPID", "FCmd");
p = file_to_first_proc(fp);
db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp,
file_type_to_name(fp->f_type), fp->f_data, fp->f_flag,
0, fp->f_count, 0, fp->f_vnode,
p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-");
}
DB_SHOW_COMMAND(file, db_show_file)
{
struct file *fp;
if (!have_addr) {
db_printf("usage: show file <addr>\n");
return;
}
fp = (struct file *)addr;
db_print_file(fp, 1);
}
DB_SHOW_COMMAND(files, db_show_files)
{
struct filedesc *fdp;
struct file *fp;
struct proc *p;
int header;
int n;
header = 1;
FOREACH_PROC_IN_SYSTEM(p) {
if (p->p_state == PRS_NEW)
continue;
if ((fdp = p->p_fd) == NULL)
continue;
for (n = 0; n < fdp->fd_nfiles; ++n) {
if ((fp = fdp->fd_ofiles[n].fde_file) == NULL)
continue;
db_print_file(fp, header);
header = 0;
}
}
}
#endif
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,
__DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files");
/* ARGSUSED*/
static void
filelistinit(void *dummy)
{
file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL,
NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF);
}
SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL);
/*-------------------------------------------------------------------*/
static int
badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred,
int flags, struct thread *td)
{
return (EBADF);
}
static int
badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
struct thread *td)
{
return (EINVAL);
}
static int
badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
struct thread *td)
{
return (EBADF);
}
static int
badfo_poll(struct file *fp, int events, struct ucred *active_cred,
struct thread *td)
{
return (0);
}
static int
badfo_kqfilter(struct file *fp, struct knote *kn)
{
return (EBADF);
}
static int
badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
struct thread *td)
{
return (EBADF);
}
static int
badfo_close(struct file *fp, struct thread *td)
{
return (EBADF);
}
static int
badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
struct thread *td)
{
return (EBADF);
}
static int
badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
struct thread *td)
{
return (EBADF);
}
static int
badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
int kflags, struct thread *td)
{
return (EBADF);
}
struct fileops badfileops = {
.fo_read = badfo_readwrite,
.fo_write = badfo_readwrite,
.fo_truncate = badfo_truncate,
.fo_ioctl = badfo_ioctl,
.fo_poll = badfo_poll,
.fo_kqfilter = badfo_kqfilter,
.fo_stat = badfo_stat,
.fo_close = badfo_close,
.fo_chmod = badfo_chmod,
.fo_chown = badfo_chown,
.fo_sendfile = badfo_sendfile,
};
int
invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
struct thread *td)
{
return (EINVAL);
}
int
invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
struct thread *td)
{
return (EINVAL);
}
int
invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
int kflags, struct thread *td)
{
return (EINVAL);
}
/*-------------------------------------------------------------------*/
/*
* 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.
*
* XXX: we could give this one a cloning event handler if necessary.
*/
/* ARGSUSED */
static int
fdopen(struct cdev *dev, int mode, int 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);
}
static struct cdevsw fildesc_cdevsw = {
.d_version = D_VERSION,
.d_open = fdopen,
.d_name = "FD",
};
static void
fildesc_drvinit(void *unused)
{
struct cdev *dev;
dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL,
UID_ROOT, GID_WHEEL, 0666, "fd/0");
make_dev_alias(dev, "stdin");
dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL,
UID_ROOT, GID_WHEEL, 0666, "fd/1");
make_dev_alias(dev, "stdout");
dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL,
UID_ROOT, GID_WHEEL, 0666, "fd/2");
make_dev_alias(dev, "stderr");
}
SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);
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