1 /* wrap getfilecon, lgetfilecon, and fgetfilecon
2 Copyright (C) 2009-2021 Free Software Foundation, Inc.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3, or (at your option)
7 any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, see <https://www.gnu.org/licenses/>. */
16
17 /* written by Jim Meyering */
18
19 #include <config.h>
20
21 #include <selinux/selinux.h>
22
23 #include <sys/types.h>
24 #include <errno.h>
25 #include <string.h>
26
27 /* FIXME: remove this once there is an errno-gnu module
28 that guarantees the definition of ENODATA. */
29 #ifndef ENODATA
30 # define ENODATA ENOTSUP
31 #endif
32
33 #undef getfilecon
34 #undef lgetfilecon
35 #undef fgetfilecon
36 int getfilecon (char const *file, char **con);
37 int lgetfilecon (char const *file, char **con);
38 int fgetfilecon (int fd, char **con);
39
40 /* getfilecon, lgetfilecon, and fgetfilecon can all misbehave, be it
41 via an old version of libselinux where these would return 0 and set the
42 result context to NULL, or via a modern kernel+lib operating on a file
43 from a disk whose attributes were set by a kernel from around 2006.
44 In that latter case, the functions return a length of 10 for the
45 "unlabeled" context. Map both failures to a return value of -1, and
46 set errno to ENOTSUP in the first case, and ENODATA in the latter. */
47
48 static int
map_to_failure(int ret,char ** con)49 map_to_failure (int ret, char **con)
50 {
51 if (ret == 0)
52 {
53 errno = ENOTSUP;
54 return -1;
55 }
56
57 if (ret == 10 && strcmp (*con, "unlabeled") == 0)
58 {
59 freecon (*con);
60 *con = NULL;
61 errno = ENODATA;
62 return -1;
63 }
64
65 return ret;
66 }
67
68 int
rpl_getfilecon(char const * file,char ** con)69 rpl_getfilecon (char const *file, char **con)
70 {
71 int ret = getfilecon (file, con);
72 return map_to_failure (ret, con);
73 }
74
75 int
rpl_lgetfilecon(char const * file,char ** con)76 rpl_lgetfilecon (char const *file, char **con)
77 {
78 int ret = lgetfilecon (file, con);
79 return map_to_failure (ret, con);
80 }
81
82 int
rpl_fgetfilecon(int fd,char ** con)83 rpl_fgetfilecon (int fd, char**con)
84 {
85 int ret = fgetfilecon (fd, con);
86 return map_to_failure (ret, con);
87 }
88