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/*
* Copyright (C) 2014-2021 Firejail Authors
*
* This file is part of firejail project
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "firejail.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <grp.h>
#include <sys/wait.h>
#include <string.h>
#ifdef HAVE_GCOV
#include <gcov.h>
#endif
static void check(const char *fname) {
// manufacture /run/user directory
char *runuser;
if (asprintf(&runuser, "/run/user/%d/", getuid()) == -1)
errExit("asprintf");
if (strncmp(fname, cfg.homedir, strlen(cfg.homedir)) != 0 &&
strncmp(fname, "/tmp", 4) != 0 &&
strncmp(fname, runuser, strlen(runuser)) != 0) {
fprintf(stderr, "Error: only files or directories in user home, /tmp, or /run/user/<UID> are supported by mkdir\n");
exit(1);
}
free(runuser);
}
static void mkdir_recursive(char *path) {
char *subdir = NULL;
struct stat s;
if (chdir("/")) {
fprintf(stderr, "Error: can't chdir to /\n");
return;
}
subdir = strtok(path, "/");
while(subdir) {
if (stat(subdir, &s) == -1) {
/* coverity[toctou] */
if (mkdir(subdir, 0700) == -1) {
fwarning("cannot create %s directory\n", subdir);
return;
}
} else if (!S_ISDIR(s.st_mode)) {
fwarning("'%s exists, but is not a directory\n", subdir);
return;
}
if (chdir(subdir)) {
fprintf(stderr, "Error: can't chdir to %s\n", subdir);
return;
}
subdir = strtok(NULL, "/");
}
}
void fs_mkdir(const char *name) {
EUID_ASSERT();
// check directory name
invalid_filename(name, 0); // no globbing
char *expanded = expand_macros(name);
check(expanded); // will exit if wrong path
struct stat s;
if (stat(expanded, &s) == 0) {
// file exists, do nothing
goto doexit;
}
// create directory
pid_t child = fork();
if (child < 0)
errExit("fork");
if (child == 0) {
// drop privileges
drop_privs(0);
// create directory
mkdir_recursive(expanded);
#ifdef HAVE_GCOV
__gcov_flush();
#endif
_exit(0);
}
// wait for the child to finish
waitpid(child, NULL, 0);
doexit:
free(expanded);
}
void fs_mkfile(const char *name) {
EUID_ASSERT();
// check file name
invalid_filename(name, 0); // no globbing
char *expanded = expand_macros(name);
check(expanded); // will exit if wrong path
struct stat s;
if (stat(expanded, &s) == 0) {
// file exists, do nothing
goto doexit;
}
// create file
touch_file_as_user(expanded, 0600);
doexit:
free(expanded);
}
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