1/*
 2 * Copyright (c) 2019 Alexey Dobriyan <adobriyan@gmail.com>
 3 *
 4 * Permission to use, copy, modify, and distribute this software for any
 5 * purpose with or without fee is hereby granted, provided that the above
 6 * copyright notice and this permission notice appear in all copies.
 7 *
 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16/* Test that pointing #! script interpreter to self doesn't recurse. */
17#include <errno.h>
18#include <sched.h>
19#include <stdio.h>
20#include <string.h>
21#include <sys/types.h>
22#include <sys/stat.h>
23#include <fcntl.h>
24#include <sys/mount.h>
25#include <unistd.h>
26
27int main(void)
28{
29	if (unshare(CLONE_NEWNS) == -1) {
30		if (errno == ENOSYS || errno == EPERM) {
31			fprintf(stderr, "error: unshare, errno %d\n", errno);
32			return 4;
33		}
34		fprintf(stderr, "error: unshare, errno %d\n", errno);
35		return 1;
36	}
37	if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
38		fprintf(stderr, "error: mount '/', errno %d\n", errno);
39		return 1;
40	}
41	/* Require "exec" filesystem. */
42	if (mount(NULL, "/tmp", "ramfs", 0, NULL) == -1) {
43		fprintf(stderr, "error: mount ramfs, errno %d\n", errno);
44		return 1;
45	}
46
47#define FILENAME "/tmp/1"
48
49	int fd = creat(FILENAME, 0700);
50	if (fd == -1) {
51		fprintf(stderr, "error: creat, errno %d\n", errno);
52		return 1;
53	}
54#define S "#!" FILENAME "\n"
55	if (write(fd, S, strlen(S)) != strlen(S)) {
56		fprintf(stderr, "error: write, errno %d\n", errno);
57		return 1;
58	}
59	close(fd);
60
61	int rv = execve(FILENAME, NULL, NULL);
62	if (rv == -1 && errno == ELOOP) {
63		return 0;
64	}
65	fprintf(stderr, "error: execve, rv %d, errno %d\n", rv, errno);
66	return 1;
67}