1#include <errno.h>
2#include <stdio.h>
3#include <stdlib.h>
4#include <string.h>
5
6#include <sepol/policydb/services.h>
7#include <sepol/sepol.h>
8
9
10int main(int argc, char *argv[])
11{
12	FILE *fp;
13	sepol_security_id_t ssid, tsid, out_sid;
14	sepol_security_class_t tclass;
15	char *context;
16	size_t context_len;
17
18	if (argc != 5) {
19		printf("usage:  %s policy scontext tcontext tclass\n", argv[0]);
20		return 1;
21	}
22
23	fp = fopen(argv[1], "r");
24	if (!fp) {
25		fprintf(stderr, "Can't open policy %s:  %s\n", argv[1], strerror(errno));
26		return 1;
27	}
28	if (sepol_set_policydb_from_file(fp) < 0) {
29		fprintf(stderr, "Error while processing policy %s:  %s\n", argv[1], strerror(errno));
30		fclose(fp);
31		return 1;
32	}
33	fclose(fp);
34
35	if (sepol_context_to_sid(argv[2], strlen(argv[2]), &ssid) < 0) {
36		fprintf(stderr, "Invalid source context %s\n", argv[2]);
37		return 1;
38	}
39
40	if (sepol_context_to_sid(argv[3], strlen(argv[3]), &tsid) < 0) {
41		fprintf(stderr, "Invalid target context %s\n", argv[3]);
42		return 1;
43	}
44
45	if (sepol_string_to_security_class(argv[4], &tclass) < 0) {
46		fprintf(stderr, "Invalid security class %s\n", argv[4]);
47		return 1;
48	}
49
50	if (sepol_member_sid(ssid, tsid, tclass, &out_sid) < 0) {
51		fprintf(stderr, "Failed to compute member sid:  %s\n", strerror(errno));
52		return 1;
53	}
54
55	if (sepol_sid_to_context(out_sid, &context, &context_len) < 0) {
56		fprintf(stderr, "Failed to convert sid %u:  %s\n", out_sid, strerror(errno));
57		return 1;
58	}
59
60	printf("%s\n", context);
61	free(context);
62
63	return 0;
64}
65