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_relabel_raw(const char * scon,const char * tcon,security_class_t tclass,char ** newcon)13 int security_compute_relabel_raw(const char * scon,
14 const char * tcon,
15 security_class_t tclass,
16 char ** newcon)
17 {
18 char path[PATH_MAX];
19 char *buf;
20 size_t size;
21 int fd, ret;
22
23 if (!selinux_mnt) {
24 errno = ENOENT;
25 return -1;
26 }
27
28 snprintf(path, sizeof path, "%s/relabel", selinux_mnt);
29 fd = open(path, O_RDWR | O_CLOEXEC);
30 if (fd < 0)
31 return -1;
32
33 size = selinux_page_size;
34 buf = malloc(size);
35 if (!buf) {
36 ret = -1;
37 goto out;
38 }
39
40 ret = snprintf(buf, size, "%s %s %hu", scon, tcon, unmap_class(tclass));
41 if (ret < 0 || (size_t)ret >= size) {
42 errno = EOVERFLOW;
43 ret = -1;
44 goto out2;
45 }
46
47 ret = write(fd, buf, strlen(buf));
48 if (ret < 0)
49 goto out2;
50
51 memset(buf, 0, size);
52 ret = read(fd, buf, size - 1);
53 if (ret < 0)
54 goto out2;
55
56 *newcon = strdup(buf);
57 if (!*newcon) {
58 ret = -1;
59 goto out2;
60 }
61 ret = 0;
62 out2:
63 free(buf);
64 out:
65 close(fd);
66 return ret;
67 }
68
69
security_compute_relabel(const char * scon,const char * tcon,security_class_t tclass,char ** newcon)70 int security_compute_relabel(const char * scon,
71 const char * tcon,
72 security_class_t tclass,
73 char ** newcon)
74 {
75 int ret;
76 char * rscon;
77 char * rtcon;
78 char * rnewcon;
79
80 if (selinux_trans_to_raw_context(scon, &rscon))
81 return -1;
82 if (selinux_trans_to_raw_context(tcon, &rtcon)) {
83 freecon(rscon);
84 return -1;
85 }
86
87 ret = security_compute_relabel_raw(rscon, rtcon, tclass, &rnewcon);
88
89 freecon(rscon);
90 freecon(rtcon);
91 if (!ret) {
92 ret = selinux_raw_to_trans_context(rnewcon, newcon);
93 freecon(rnewcon);
94 }
95
96 return ret;
97 }
98