summaryrefslogtreecommitdiff
path: root/udev/sd-daemon.c
blob: e12fb0483abfb8c4d690ffc62ee51622daa245fb (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
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  Copyright 2010 Lennart Poettering

  Permission is hereby granted, free of charge, to any person
  obtaining a copy of this software and associated documentation files
  (the "Software"), to deal in the Software without restriction,
  including without limitation the rights to use, copy, modify, merge,
  publish, distribute, sublicense, and/or sell copies of the Software,
  and to permit persons to whom the Software is furnished to do so,
  subject to the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
***/

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/fcntl.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h>
#include <stddef.h>

#include "sd-daemon.h"

int sd_listen_fds(int unset_environment) {

#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
        return 0;
#else
        int r, fd;
        const char *e;
        char *p = NULL;
        unsigned long l;

        if (!(e = getenv("LISTEN_PID"))) {
                r = 0;
                goto finish;
        }

        errno = 0;
        l = strtoul(e, &p, 10);

        if (errno != 0) {
                r = -errno;
                goto finish;
        }

        if (!p || *p || l <= 0) {
                r = -EINVAL;
                goto finish;
        }

        /* Is this for us? */
        if (getpid() != (pid_t) l) {
                r = 0;
                goto finish;
        }

        if (!(e = getenv("LISTEN_FDS"))) {
                r = 0;
                goto finish;
        }

        errno = 0;
        l = strtoul(e, &p, 10);

        if (errno != 0) {
                r = -errno;
                goto finish;
        }

        if (!p || *p) {
                r = -EINVAL;
                goto finish;
        }

        for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + (int) l; fd ++) {
                int flags;

                if ((flags = fcntl(fd, F_GETFD)) < 0) {
                        r = -errno;
                        goto finish;
                }

                if (flags & FD_CLOEXEC)
                        continue;

                if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0) {
                        r = -errno;
                        goto finish;
                }
        }

        r = (int) l;

finish:
        if (unset_environment) {
                unsetenv("LISTEN_PID");
                unsetenv("LISTEN_FDS");
        }

        return r;
#endif
}

int sd_is_fifo(int fd, const char *path) {
        struct stat st_fd;

        if (fd < 0)
                return -EINVAL;

        memset(&st_fd, 0, sizeof(st_fd));
        if (fstat(fd, &st_fd) < 0)
                return -errno;

        if (!S_ISFIFO(st_fd.st_mode))
                return 0;

        if (path) {
                struct stat st_path;

                memset(&st_path, 0, sizeof(st_path));
                if (stat(path, &st_path) < 0) {

                        if (errno == ENOENT || errno == ENOTDIR)
                                return 0;

                        return -errno;
                }

                return
                        st_path.st_dev == st_fd.st_dev &&
                        st_path.st_ino == st_fd.st_ino;
        }

        return 1;
}

static int sd_is_socket_internal(int fd, int type, int listening) {
        struct stat st_fd;

        if (fd < 0 || type < 0)
                return -EINVAL;

        if (fstat(fd, &st_fd) < 0)
                return -errno;

        if (!S_ISSOCK(st_fd.st_mode))
                return 0;

        if (type != 0) {
                int other_type = 0;
                socklen_t l = sizeof(other_type);

                if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &other_type, &l) < 0)
                        return -errno;

                if (l != sizeof(other_type))
                        return -EINVAL;

                if (other_type != type)
                        return 0;
        }

        if (listening >= 0) {
                int accepting = 0;
                socklen_t l = sizeof(accepting);

                if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &accepting, &l) < 0)
                        return -errno;

                if (l != sizeof(accepting))
                        return -EINVAL;

                if (!accepting != !listening)
                        return 0;
        }

        return 1;
}

union sockaddr_union {
        struct sockaddr sa;
        struct sockaddr_in in4;
        struct sockaddr_in6 in6;
        struct sockaddr_un un;
        struct sockaddr_storage storage;
};

int sd_is_socket(int fd, int family, int type, int listening) {
        int r;

        if (family < 0)
                return -EINVAL;

        if ((r = sd_is_socket_internal(fd, type, listening)) <= 0)
                return r;

        if (family > 0) {
                union sockaddr_union sockaddr;
                socklen_t l;

                memset(&sockaddr, 0, sizeof(sockaddr));
                l = sizeof(sockaddr);

                if (getsockname(fd, &sockaddr.sa, &l) < 0)
                        return -errno;

                if (l < offsetof(struct sockaddr_un, sun_path))
                        return -EINVAL;

                return sockaddr.sa.sa_family == family;
        }

        return 1;
}

int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port) {
        union sockaddr_union sockaddr;
        socklen_t l;
        int r;

        if (family != 0 && family != AF_INET && family != AF_INET6)
                return -EINVAL;

        if ((r = sd_is_socket_internal(fd, type, listening)) <= 0)
                return r;

        memset(&sockaddr, 0, sizeof(sockaddr));
        l = sizeof(sockaddr);

        if (getsockname(fd, &sockaddr.sa, &l) < 0)
                return -errno;

        if (l < offsetof(struct sockaddr_un, sun_path))
                return -EINVAL;

        if (sockaddr.sa.sa_family != AF_INET &&
            sockaddr.sa.sa_family != AF_INET6)
                return 0;

        if (family > 0)
                if (sockaddr.sa.sa_family != family)
                        return 0;

        if (port > 0) {
                if (sockaddr.sa.sa_family == AF_INET) {
                        if (l < sizeof(struct sockaddr_in))
                                return -EINVAL;

                        return htons(port) == sockaddr.in4.sin_port;
                } else {
                        if (l < sizeof(struct sockaddr_in6))
                                return -EINVAL;

                        return htons(port) == sockaddr.in6.sin6_port;
                }
        }

        return 1;
}

int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length) {
        union sockaddr_union sockaddr;
        socklen_t l;
        int r;

        if ((r = sd_is_socket_internal(fd, type, listening)) <= 0)
                return r;

        memset(&sockaddr, 0, sizeof(sockaddr));
        l = sizeof(sockaddr);

        if (getsockname(fd, &sockaddr.sa, &l) < 0)
                return -errno;

        if (l < offsetof(struct sockaddr_un, sun_path))
                return -EINVAL;

        if (sockaddr.sa.sa_family != AF_UNIX)
                return 0;

        if (path) {
                if (length <= 0)
                        length = strlen(path);

                if (length <= 0)
                        /* Unnamed socket */
                        return l == offsetof(struct sockaddr_un, sun_path);

                if (path[0])
                        /* Normal path socket */
                        return
                                (l >= offsetof(struct sockaddr_un, sun_path) + length + 1) &&
                                memcmp(path, sockaddr.un.sun_path, length+1) == 0;
                else
                        /* Abstract namespace socket */
                        return
                                (l == offsetof(struct sockaddr_un, sun_path) + length) &&
                                memcmp(path, sockaddr.un.sun_path, length) == 0;
        }

        return 1;
}

int sd_notify(int unset_environment, const char *state) {
#if defined(DISABLE_SYSTEMD) || !defined(__linux__) || !defined(SOCK_CLOEXEC)
        return 0;
#else
        int fd = -1, r;
        struct msghdr msghdr;
        struct iovec iovec;
        union sockaddr_union sockaddr;
        const char *e;

        if (!state) {
                r = -EINVAL;
                goto finish;
        }

        if (!(e = getenv("NOTIFY_SOCKET")))
                return 0;

        /* Must be an abstract socket, or an absolute path */
        if ((e[0] != '@' && e[0] != '/') || e[1] == 0) {
                r = -EINVAL;
                goto finish;
        }

        if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
                r = -errno;
                goto finish;
        }

        memset(&sockaddr, 0, sizeof(sockaddr));
        sockaddr.sa.sa_family = AF_UNIX;
        strncpy(sockaddr.un.sun_path, e, sizeof(sockaddr.un.sun_path));

        if (sockaddr.un.sun_path[0] == '@')
                sockaddr.un.sun_path[0] = 0;

        memset(&iovec, 0, sizeof(iovec));
        iovec.iov_base = (char*) state;
        iovec.iov_len = strlen(state);

        memset(&msghdr, 0, sizeof(msghdr));
        msghdr.msg_name = &sockaddr;
        msghdr.msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(e);

        if (msghdr.msg_namelen > sizeof(struct sockaddr_un))
                msghdr.msg_namelen = sizeof(struct sockaddr_un);

        msghdr.msg_iov = &iovec;
        msghdr.msg_iovlen = 1;

        if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) {
                r = -errno;
                goto finish;
        }

        r = 1;

finish:
        if (unset_environment)
                unsetenv("NOTIFY_SOCKET");

        if (fd >= 0)
                close(fd);

        return r;
#endif
}

int sd_notifyf(int unset_environment, const char *format, ...) {
#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
        return 0;
#else
        va_list ap;
        char *p = NULL;
        int r;

        va_start(ap, format);
        r = vasprintf(&p, format, ap);
        va_end(ap);

        if (r < 0 || !p)
                return -ENOMEM;

        r = sd_notify(unset_environment, p);
        free(p);

        return r;
#endif
}

int sd_booted(void) {
#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
        return 0;
#else

        struct stat a, b;

        /* We simply test whether the systemd cgroup hierarchy is
         * mounted */

        if (lstat("/sys/fs/cgroup", &a) < 0)
                return 0;

        if (lstat("/sys/fs/cgroup/systemd", &b) < 0)
                return 0;

        return a.st_dev != b.st_dev;
#endif
}