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
security_compute_av(const char * scon,const char * tcon,security_class_t tclass,access_vector_t requested,struct av_decision * avd)13 int 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