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/* uroot - User's root
* child.c Source file for child with unshared resources
*
* Copyright (C) 2018-2019 Karel Kočí
*
* 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.
*/
#define _GNU_SOURCE
#include "child.h"
#include <stdlib.h>
#include <sys/mount.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include "utils.h"
#define PROC_BINFMT "/proc/sys/fs/binfmt_misc"
int child_main(void *_args) {
struct child_args *args = _args;
sigpipe_wait(args->sigpipe);
// Change all mount points to private
mount("none", "/", NULL, MS_REC | MS_PRIVATE, NULL);
assert_perror(errno);
// Mount new proc filesystem for this namespace
if (args->binfmt) {
mount(PROC_BINFMT, "/tmp", NULL, MS_BIND, NULL);
assert_perror(errno);
}
mount("proc", "/proc", "proc", MS_NOSUID | MS_NODEV | MS_NOEXEC, NULL);
assert_perror(errno);
if (args->binfmt) {
mount("/tmp", PROC_BINFMT, NULL, MS_MOVE, NULL);
assert_perror(errno);
}
if (args->argc <= 1) {
const char *shell = get_shell();
execl(shell, shell, NULL);
} else {
execvp(args->argv[0], args->argv);
assert_perror(errno);
}
return 1;
}
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