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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#pragma weak closefrom = _closefrom
#pragma weak fdwalk = _fdwalk
#include "synonyms.h"
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <dirent.h>
#include <limits.h>
#include <errno.h>
#include <alloca.h>
#include <sys/resource.h>
/* Initial size of the open file descriptor array */
#define FDS_SZ (1024 * sizeof (int))
/*
* Iterate over all open file descriptors, calling 'func' on each one.
* Terminate the iteration when 'func' returns non-zero or when all
* open file descriptors have been processed. Return the value of
* the last non-zero return from 'func' or zero.
*/
int
fdwalk(int (*func)(void *, int), void *cd)
{
int err = errno;
int rv = 0;
int max_fds = INT_MAX;
struct rlimit rl;
DIR *dirp;
struct dirent64 *dp;
int *fds;
size_t fds_sz;
int nfds;
int i;
nfds = 0;
fds = alloca(FDS_SZ);
fds_sz = FDS_SZ;
if ((dirp = opendir("/proc/self/fd")) != NULL) {
/*
* Collect all of the open file descriptors and close
* the directory before calling 'func' on any of them.
*/
while ((dp = readdir64(dirp)) != NULL) {
/* skip '.', '..' and the opendir() fd */
if (!isdigit(dp->d_name[0]) ||
(i = atoi(dp->d_name)) == dirp->dd_fd)
continue;
if (fds_sz <= nfds * sizeof (int)) {
fds = memcpy(alloca(fds_sz * 2), fds, fds_sz);
fds_sz *= 2;
}
fds[nfds++] = i;
}
(void) closedir(dirp);
} else {
/*
* We could not open the /proc file descriptor directory.
* We have to do it the hard way.
*/
if (getrlimit(RLIMIT_NOFILE, &rl) == 0)
max_fds = (rl.rlim_max == RLIM_INFINITY)?
INT_MAX : rl.rlim_max;
for (i = 0; i < max_fds; i++) {
if (fcntl(i, F_GETFD) < 0)
continue;
if (fds_sz <= nfds * sizeof (int)) {
fds = memcpy(alloca(fds_sz * 2), fds, fds_sz);
fds_sz *= 2;
}
fds[nfds++] = i;
}
}
/*
* Restore the original value of errno so that
* the caller sees only the value of errno set
* by the callback function.
*/
errno = err;
/*
* Perform the callbacks on all of the open files.
*/
for (i = 0; i < nfds; i++)
if ((rv = func(cd, fds[i])) != 0)
break;
return (rv);
}
/*
* Call-back function for closefrom(), below.
*/
static int
void_close(void *lowp, int fd)
{
if (fd >= *(int *)lowp)
(void) close(fd);
return (0);
}
/*
* Close all open file descriptors greater than or equal to lowfd.
*/
void
closefrom(int lowfd)
{
int low = (lowfd < 0)? 0 : lowfd;
/*
* Close lowfd right away as a hedge against failing
* to open the /proc file descriptor directory due
* all file descriptors being currently used up.
*/
(void) close(low++);
(void) fdwalk(void_close, &low);
}
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