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 "selinux_internal.h"
9#include "policy.h"
10#include <limits.h>
11
12int security_canonicalize_context_raw(const char * con,
13				      char ** canoncon)
14{
15	char path[PATH_MAX];
16	char *buf;
17	size_t size;
18	int fd, ret;
19
20	if (!selinux_mnt) {
21		errno = ENOENT;
22		return -1;
23	}
24
25	snprintf(path, sizeof path, "%s/context", selinux_mnt);
26	fd = open(path, O_RDWR | O_CLOEXEC);
27	if (fd < 0)
28		return -1;
29
30	size = selinux_page_size;
31	buf = malloc(size);
32	if (!buf) {
33		ret = -1;
34		goto out;
35	}
36	if (strlcpy(buf, con, size) >= size) {
37		errno = EOVERFLOW;
38		ret = -1;
39		goto out2;
40	}
41
42	ret = write(fd, buf, strlen(buf) + 1);
43	if (ret < 0)
44		goto out2;
45
46	memset(buf, 0, size);
47	ret = read(fd, buf, size - 1);
48	if (ret < 0 && errno == EINVAL) {
49		/* Fall back to the original context for kernels
50		   that do not support the extended interface. */
51		strncpy(buf, con, size);
52	}
53
54	*canoncon = strdup(buf);
55	if (!(*canoncon)) {
56		ret = -1;
57		goto out2;
58	}
59	ret = 0;
60      out2:
61	free(buf);
62      out:
63	close(fd);
64	return ret;
65}
66
67
68int security_canonicalize_context(const char * con,
69				      char ** canoncon)
70{
71	int ret;
72	char * rcon;
73	char * rcanoncon;
74
75	if (selinux_trans_to_raw_context(con, &rcon))
76		return -1;
77
78	ret = security_canonicalize_context_raw(rcon, &rcanoncon);
79
80	freecon(rcon);
81	if (!ret) {
82		ret = selinux_raw_to_trans_context(rcanoncon, canoncon);
83		freecon(rcanoncon);
84	}
85
86	return ret;
87}
88
89