1#include <unistd.h>
2#include <sys/types.h>
3#include <fcntl.h>
4#include <stdlib.h>
5#include <stdio.h>
6#include <errno.h>
7#include <string.h>
8#include <limits.h>
9#include "selinux_internal.h"
10#include "policy.h"
11#include "mapping.h"
12
13int security_compute_av(const char * scon,
14			const char * tcon,
15			security_class_t tclass,
16			access_vector_t requested,
17			struct av_decision *avd)
18{
19	char path[PATH_MAX];
20	char *buf;
21	size_t len;
22	int fd, ret;
23
24	if (!selinux_mnt) {
25		errno = ENOENT;
26		return -1;
27	}
28
29	snprintf(path, sizeof path, "%s/access", selinux_mnt);
30	fd = open(path, O_RDWR);
31	if (fd < 0)
32		return -1;
33
34	len = selinux_page_size;
35	buf = malloc(len);
36	if (!buf) {
37		ret = -1;
38		goto out;
39	}
40
41	snprintf(buf, len, "%s %s %hu %x", scon, tcon,
42		 unmap_class(tclass), unmap_perm(tclass, requested));
43
44	ret = write(fd, buf, strlen(buf));
45	if (ret < 0)
46		goto out2;
47
48	memset(buf, 0, len);
49	ret = read(fd, buf, len - 1);
50	if (ret < 0)
51		goto out2;
52
53	ret = sscanf(buf, "%x %x %x %x %u %x",
54		     &avd->allowed, &avd->decided,
55		     &avd->auditallow, &avd->auditdeny,
56		     &avd->seqno, &avd->flags);
57	if (ret < 5) {
58		ret = -1;
59		goto out2;
60	} else if (ret < 6)
61		avd->flags = 0;
62
63	map_decision(tclass, avd);
64
65	ret = 0;
66      out2:
67	free(buf);
68      out:
69	close(fd);
70	return ret;
71}
72
73