1#include <cap-ng.h>
2#include <err.h>
3#include <linux/capability.h>
4#include <stdbool.h>
5#include <string.h>
6#include <stdio.h>
7#include <sys/prctl.h>
8#include <sys/auxv.h>
9
10#ifndef PR_CAP_AMBIENT
11#define PR_CAP_AMBIENT			47
12# define PR_CAP_AMBIENT_IS_SET		1
13# define PR_CAP_AMBIENT_RAISE		2
14# define PR_CAP_AMBIENT_LOWER		3
15# define PR_CAP_AMBIENT_CLEAR_ALL	4
16#endif
17
18#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 19)
19# define HAVE_GETAUXVAL
20#endif
21
22static bool bool_arg(char **argv, int i)
23{
24	if (!strcmp(argv[i], "0"))
25		return false;
26	else if (!strcmp(argv[i], "1"))
27		return true;
28	else
29		errx(1, "wrong argv[%d]", i);
30}
31
32int main(int argc, char **argv)
33{
34	const char *atsec = "";
35
36	/*
37	 * Be careful just in case a setgid or setcapped copy of this
38	 * helper gets out.
39	 */
40
41	if (argc != 5)
42		errx(1, "wrong argc");
43
44#ifdef HAVE_GETAUXVAL
45	if (getauxval(AT_SECURE))
46		atsec = " (AT_SECURE is set)";
47	else
48		atsec = " (AT_SECURE is not set)";
49#endif
50
51	capng_get_caps_process();
52
53	if (capng_have_capability(CAPNG_EFFECTIVE, CAP_NET_BIND_SERVICE) != bool_arg(argv, 1)) {
54		printf("[FAIL]\tWrong effective state%s\n", atsec);
55		return 1;
56	}
57	if (capng_have_capability(CAPNG_PERMITTED, CAP_NET_BIND_SERVICE) != bool_arg(argv, 2)) {
58		printf("[FAIL]\tWrong permitted state%s\n", atsec);
59		return 1;
60	}
61	if (capng_have_capability(CAPNG_INHERITABLE, CAP_NET_BIND_SERVICE) != bool_arg(argv, 3)) {
62		printf("[FAIL]\tWrong inheritable state%s\n", atsec);
63		return 1;
64	}
65
66	if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_NET_BIND_SERVICE, 0, 0, 0) != bool_arg(argv, 4)) {
67		printf("[FAIL]\tWrong ambient state%s\n", atsec);
68		return 1;
69	}
70
71	printf("[OK]\tCapabilities after execve were correct\n");
72	return 0;
73}
74