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/*
* Unix SMB/CIFS implementation.
* Samba utility functions
* Copyright (C) Volker Lendecke 2016
*
* ** NOTE! The following LGPL license applies to the replace
* ** library. This does NOT imply that all of Samba is released
* ** under the LGPL
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include <dirent.h>
#include <unistd.h>
#include <limits.h>
static int closefrom_sysconf(int lower)
{
long max_files, fd;
max_files = sysconf(_SC_OPEN_MAX);
if (max_files == -1) {
max_files = 65536;
}
for (fd=lower; fd<max_files; fd++) {
close(fd);
}
return 0;
}
static int closefrom_procfs(int lower)
{
DIR *dirp;
int dir_fd;
struct dirent *dp;
int *fds = NULL;
size_t num_fds = 0;
size_t fd_array_size = 0;
size_t i;
int ret = ENOMEM;
dirp = opendir("/proc/self/fd");
if (dirp == NULL) {
return errno;
}
dir_fd = dirfd(dirp);
if (dir_fd == -1) {
ret = errno;
goto fail;
}
while ((dp = readdir(dirp)) != NULL) {
char *endptr;
unsigned long long fd;
errno = 0;
fd = strtoull(dp->d_name, &endptr, 10);
if ((fd == 0) && (errno == EINVAL)) {
continue;
}
if ((fd == ULLONG_MAX) && (errno == ERANGE)) {
continue;
}
if (*endptr != '\0') {
continue;
}
if (fd == dir_fd) {
continue;
}
if (fd > INT_MAX) {
continue;
}
if (fd < lower) {
continue;
}
if (num_fds >= (fd_array_size / sizeof(int))) {
void *tmp;
if (fd_array_size == 0) {
fd_array_size = 16 * sizeof(int);
} else {
if (fd_array_size + fd_array_size <
fd_array_size) {
/* overflow */
goto fail;
}
fd_array_size = fd_array_size + fd_array_size;
}
tmp = realloc(fds, fd_array_size);
if (tmp == NULL) {
goto fail;
}
fds = tmp;
}
fds[num_fds++] = fd;
}
for (i=0; i<num_fds; i++) {
close(fds[i]);
}
ret = 0;
fail:
closedir(dirp);
free(fds);
return ret;
}
int rep_closefrom(int lower)
{
int ret;
ret = closefrom_procfs(lower);
if (ret == 0) {
return 0;
}
return closefrom_sysconf(lower);
}
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