summaryrefslogtreecommitdiff
path: root/src/label.c
blob: a5994622c70ecef5e7ef03efb5e78503348a6151 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <errno.h>
#include <sys/stat.h>
#include <unistd.h>
#include <malloc.h>

#include "label.h"
#include "util.h"

#ifdef HAVE_SELINUX
#include <selinux/selinux.h>
#include <selinux/label.h>

static struct selabel_handle *label_hnd = NULL;

static inline bool use_selinux(void) {
        static int use_selinux_cached = -1;

        if (use_selinux_cached < 0)
                use_selinux_cached = is_selinux_enabled() > 0;

        return use_selinux_cached;
}

#endif

int label_init(void) {
        int r = 0;

#ifdef HAVE_SELINUX
        usec_t before_timestamp, after_timestamp;
        struct mallinfo before_mallinfo, after_mallinfo;

        if (!use_selinux())
                return 0;

        if (label_hnd)
                return 0;

        before_mallinfo = mallinfo();
        before_timestamp = now(CLOCK_MONOTONIC);

        label_hnd = selabel_open(SELABEL_CTX_FILE, NULL, 0);
        if (!label_hnd) {
                log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
                         "Failed to initialize SELinux context: %m");
                r = security_getenforce() == 1 ? -errno : 0;
        } else  {
                char timespan[FORMAT_TIMESPAN_MAX];
                int l;

                after_timestamp = now(CLOCK_MONOTONIC);
                after_mallinfo = mallinfo();

                l = after_mallinfo.uordblks > before_mallinfo.uordblks ? after_mallinfo.uordblks - before_mallinfo.uordblks : 0;

                log_info("Successfully loaded SELinux database in %s, size on heap is %iK.",
                         format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp),
                         (l+1023)/1024);
        }
#endif

        return r;
}

int label_fix(const char *path, bool ignore_enoent) {
        int r = 0;

#ifdef HAVE_SELINUX
        struct stat st;
        security_context_t fcon;

        if (!use_selinux() || !label_hnd)
                return 0;

        r = lstat(path, &st);
        if (r == 0) {
                r = selabel_lookup_raw(label_hnd, &fcon, path, st.st_mode);

                /* If there's no label to set, then exit without warning */
                if (r < 0 && errno == ENOENT)
                        return 0;

                if (r == 0) {
                        r = setfilecon(path, fcon);
                        freecon(fcon);

                        /* If the FS doesn't support labels, then exit without warning */
                        if (r < 0 && errno == ENOTSUP)
                                return 0;
                }
        }

        if (r < 0) {
                /* Ignore ENOENT in some cases */
                if (ignore_enoent && errno == ENOENT)
                        return 0;

                log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
                         "Unable to fix label of %s: %m", path);
                r = security_getenforce() == 1 ? -errno : 0;
        }
#endif

        return r;
}

void label_finish(void) {

#ifdef HAVE_SELINUX
        if (use_selinux() && label_hnd)
                selabel_close(label_hnd);
#endif
}

int label_get_create_label_from_exe(const char *exe, char **label) {

        int r = 0;

#ifdef HAVE_SELINUX
        security_context_t mycon = NULL, fcon = NULL;
        security_class_t sclass;

        if (!use_selinux()) {
                *label = NULL;
                return 0;
        }

        r = getcon(&mycon);
        if (r < 0)
                goto fail;

        r = getfilecon(exe, &fcon);
        if (r < 0)
                goto fail;

        sclass = string_to_security_class("process");
        r = security_compute_create(mycon, fcon, sclass, (security_context_t *) label);
        if (r == 0)
                log_debug("SELinux Socket context for %s will be set to %s", exe, *label);

fail:
        if (r < 0 && security_getenforce() == 1)
                r = -errno;

        freecon(mycon);
        freecon(fcon);
#endif

        return r;
}

int label_fifofile_set(const char *path) {
        int r = 0;

#ifdef HAVE_SELINUX
        security_context_t filecon = NULL;

        if (!use_selinux() || !label_hnd)
                return 0;

        if ((r = selabel_lookup_raw(label_hnd, &filecon, path, S_IFIFO)) == 0) {
                if ((r = setfscreatecon(filecon)) < 0) {
                        log_error("Failed to set SELinux file context on %s: %m", path);
                        r = -errno;
                }

                freecon(filecon);
        }

        if (r < 0 && security_getenforce() == 0)
                r = 0;
#endif

        return r;
}

int label_symlinkfile_set(const char *path) {
        int r = 0;

#ifdef HAVE_SELINUX
        security_context_t filecon = NULL;

        if (!use_selinux() || !label_hnd)
                return 0;

        if ((r = selabel_lookup_raw(label_hnd, &filecon, path, S_IFLNK)) == 0) {
                if ((r = setfscreatecon(filecon)) < 0) {
                        log_error("Failed to set SELinux file context on %s: %m", path);
                        r = -errno;
                }

                freecon(filecon);
        }

        if (r < 0 && security_getenforce() == 0)
                r = 0;
#endif

        return r;
}

int label_socket_set(const char *label) {

#ifdef HAVE_SELINUX
        if (!use_selinux())
                return 0;

        if (setsockcreatecon((security_context_t) label) < 0) {
                log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
                         "Failed to set SELinux context (%s) on socket: %m", label);

                if (security_getenforce() == 1)
                        return -errno;
        }
#endif

        return 0;
}

void label_file_clear(void) {

#ifdef HAVE_SELINUX
        if (!use_selinux())
                return;

        setfscreatecon(NULL);
#endif
}

void label_socket_clear(void) {

#ifdef HAVE_SELINUX
        if (!use_selinux())
                return;

        setsockcreatecon(NULL);
#endif
}

void label_free(const char *label) {

#ifdef HAVE_SELINUX
        if (!use_selinux())
                return;

        freecon((security_context_t) label);
#endif
}

int label_mkdir(
        const char *path,
        mode_t mode) {

        /* Creates a directory and labels it according to the SELinux policy */

#ifdef HAVE_SELINUX
        int r;
        security_context_t fcon = NULL;

        if (use_selinux() && label_hnd) {

                if (path_is_absolute(path))
                        r = selabel_lookup_raw(label_hnd, &fcon, path, mode);
                else {
                        char *newpath = NULL;

                        if (!(newpath = path_make_absolute_cwd(path)))
                                return -ENOMEM;

                        r = selabel_lookup_raw(label_hnd, &fcon, newpath, mode);
                        free(newpath);
                }

                if (r == 0)
                        r = setfscreatecon(fcon);

                if (r < 0 && errno != ENOENT) {
                        log_error("Failed to set security context %s for %s: %m", fcon, path);
                        r = -errno;

                        if (security_getenforce() == 1)
                                goto finish;
                }
        }

        if ((r = mkdir(path, mode)) < 0)
                r = -errno;

finish:
        if (use_selinux() && label_hnd) {
                setfscreatecon(NULL);
                freecon(fcon);
        }

        return r;
#else
        return mkdir(path, mode);
#endif
}