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Commit | Line | Data |
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ba6929f6 KS |
1 | /* |
2 | * libudev - interface to udev device information | |
3 | * | |
065db052 | 4 | * Copyright (C) 2008-2009 Kay Sievers <kay.sievers@vrfy.org> |
ba6929f6 | 5 | * |
4061ab9f KS |
6 | * This library is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU Lesser General Public | |
8 | * License as published by the Free Software Foundation; either | |
9 | * version 2.1 of the License, or (at your option) any later version. | |
ba6929f6 KS |
10 | */ |
11 | ||
ba6929f6 KS |
12 | #include <stdio.h> |
13 | #include <stdlib.h> | |
14 | #include <stddef.h> | |
15 | #include <unistd.h> | |
16 | #include <errno.h> | |
17 | #include <string.h> | |
18 | #include <dirent.h> | |
e14bdd88 | 19 | #include <sys/poll.h> |
ba6929f6 KS |
20 | #include <sys/stat.h> |
21 | #include <sys/socket.h> | |
22 | #include <sys/un.h> | |
e14bdd88 | 23 | #include <arpa/inet.h> |
1c7047ea | 24 | #include <linux/netlink.h> |
e14bdd88 | 25 | #include <linux/filter.h> |
ba6929f6 KS |
26 | |
27 | #include "libudev.h" | |
28 | #include "libudev-private.h" | |
ba6929f6 | 29 | |
ce1d6d7f KS |
30 | /** |
31 | * SECTION:libudev-monitor | |
32 | * @short_description: device event source | |
33 | * | |
34 | * Connects to a device event source. | |
35 | */ | |
36 | ||
ce1d6d7f KS |
37 | /** |
38 | * udev_monitor: | |
39 | * | |
40 | * Opaque object handling one event source. | |
41 | */ | |
ba6929f6 KS |
42 | struct udev_monitor { |
43 | struct udev *udev; | |
44 | int refcount; | |
d59f11e1 | 45 | int sock; |
1c7047ea | 46 | struct sockaddr_nl snl; |
1e03b754 KS |
47 | struct sockaddr_nl snl_trusted_sender; |
48 | struct sockaddr_nl snl_destination; | |
1c7047ea | 49 | struct sockaddr_un sun; |
d59f11e1 | 50 | socklen_t addrlen; |
e14bdd88 | 51 | struct udev_list_node filter_subsystem_list; |
ba6929f6 KS |
52 | }; |
53 | ||
f2b93744 | 54 | enum udev_monitor_netlink_group { |
1e03b754 KS |
55 | UDEV_MONITOR_NONE, |
56 | UDEV_MONITOR_KERNEL, | |
57 | UDEV_MONITOR_UDEV, | |
f2b93744 KS |
58 | }; |
59 | ||
e14bdd88 KS |
60 | #define UDEV_MONITOR_MAGIC 0xcafe1dea |
61 | struct udev_monitor_netlink_header { | |
62 | /* udev version text */ | |
63 | char version[16]; | |
64 | /* | |
65 | * magic to protect against daemon <-> library message format mismatch | |
66 | * used in the kernel from socket filter rules; needs to be stored in network order | |
67 | */ | |
68 | unsigned int magic; | |
69 | /* properties buffer */ | |
70 | unsigned short properties_off; | |
71 | unsigned short properties_len; | |
72 | /* | |
dacea9ff | 73 | * hashes of some common device properties strings to filter with socket filters in |
c7dff03e KS |
74 | * the client used in the kernel from socket filter rules; needs to be stored in |
75 | * network order | |
e14bdd88 KS |
76 | */ |
77 | unsigned int filter_subsystem; | |
dacea9ff | 78 | unsigned int filter_devtype; |
e14bdd88 KS |
79 | }; |
80 | ||
81 | static struct udev_monitor *udev_monitor_new(struct udev *udev) | |
82 | { | |
83 | struct udev_monitor *udev_monitor; | |
84 | ||
85 | udev_monitor = calloc(1, sizeof(struct udev_monitor)); | |
86 | if (udev_monitor == NULL) | |
87 | return NULL; | |
88 | udev_monitor->refcount = 1; | |
89 | udev_monitor->udev = udev; | |
90 | udev_list_init(&udev_monitor->filter_subsystem_list); | |
91 | return udev_monitor; | |
92 | } | |
93 | ||
7d8787b3 KS |
94 | /** |
95 | * udev_monitor_new_from_socket: | |
96 | * @udev: udev library context | |
97 | * @socket_path: unix socket path | |
98 | * | |
ff109b8d KS |
99 | * Create new udev monitor and connect to a specified socket. The |
100 | * path to a socket either points to an existing socket file, or if | |
101 | * the socket path starts with a '@' character, an abstract namespace | |
7d8787b3 KS |
102 | * socket will be used. |
103 | * | |
ff109b8d KS |
104 | * A socket file will not be created. If it does not already exist, |
105 | * it will fall-back and connect to an abstract namespace socket with | |
106 | * the given path. The permissions adjustment of a socket file, as | |
107 | * well as the later cleanup, needs to be done by the caller. | |
108 | * | |
7d8787b3 | 109 | * The initial refcount is 1, and needs to be decremented to |
be7de409 | 110 | * release the resources of the udev monitor. |
7d8787b3 KS |
111 | * |
112 | * Returns: a new udev monitor, or #NULL, in case of an error | |
113 | **/ | |
ba6929f6 KS |
114 | struct udev_monitor *udev_monitor_new_from_socket(struct udev *udev, const char *socket_path) |
115 | { | |
116 | struct udev_monitor *udev_monitor; | |
9925ab04 | 117 | struct stat statbuf; |
ba6929f6 KS |
118 | |
119 | if (udev == NULL) | |
120 | return NULL; | |
121 | if (socket_path == NULL) | |
122 | return NULL; | |
e14bdd88 | 123 | udev_monitor = udev_monitor_new(udev); |
ba6929f6 KS |
124 | if (udev_monitor == NULL) |
125 | return NULL; | |
ba6929f6 | 126 | |
1c7047ea | 127 | udev_monitor->sun.sun_family = AF_LOCAL; |
81d9e221 | 128 | if (socket_path[0] == '@') { |
9925ab04 | 129 | /* translate leading '@' to abstract namespace */ |
065db052 | 130 | util_strscpy(udev_monitor->sun.sun_path, sizeof(udev_monitor->sun.sun_path), socket_path); |
1c7047ea | 131 | udev_monitor->sun.sun_path[0] = '\0'; |
9925ab04 | 132 | udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(socket_path); |
81d9e221 | 133 | } else if (stat(socket_path, &statbuf) == 0 && S_ISSOCK(statbuf.st_mode)) { |
9925ab04 | 134 | /* existing socket file */ |
065db052 | 135 | util_strscpy(udev_monitor->sun.sun_path, sizeof(udev_monitor->sun.sun_path), socket_path); |
9925ab04 KS |
136 | udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(socket_path); |
137 | } else { | |
138 | /* no socket file, assume abstract namespace socket */ | |
065db052 | 139 | util_strscpy(&udev_monitor->sun.sun_path[1], sizeof(udev_monitor->sun.sun_path)-1, socket_path); |
9925ab04 KS |
140 | udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(socket_path)+1; |
141 | } | |
d59f11e1 KS |
142 | udev_monitor->sock = socket(AF_LOCAL, SOCK_DGRAM, 0); |
143 | if (udev_monitor->sock == -1) { | |
659353f5 | 144 | err(udev, "error getting socket: %m\n"); |
ba6929f6 KS |
145 | free(udev_monitor); |
146 | return NULL; | |
147 | } | |
4b09a2fc AJ |
148 | util_set_fd_cloexec(udev_monitor->sock); |
149 | ||
86b57788 | 150 | dbg(udev, "monitor %p created with '%s'\n", udev_monitor, socket_path); |
d59f11e1 KS |
151 | return udev_monitor; |
152 | } | |
ba6929f6 | 153 | |
ff109b8d KS |
154 | /** |
155 | * udev_monitor_new_from_netlink: | |
156 | * @udev: udev library context | |
157 | * @name: name of event source | |
158 | * | |
159 | * Create new udev monitor and connect to a specified event | |
160 | * source. Valid sources identifiers are "udev" and "kernel". | |
161 | * | |
162 | * Applications should usually not connect directly to the | |
163 | * "kernel" events, because the devices might not be useable | |
164 | * at that time, before udev has configured them, and created | |
165 | * device nodes. | |
166 | * | |
167 | * Accessing devices at the same time as udev, might result | |
168 | * in unpredictable behavior. | |
169 | * | |
170 | * The "udev" events are sent out after udev has finished its | |
171 | * event processing, all rules have been processed, and needed | |
172 | * device nodes are created. | |
173 | * | |
174 | * The initial refcount is 1, and needs to be decremented to | |
175 | * release the resources of the udev monitor. | |
176 | * | |
177 | * Returns: a new udev monitor, or #NULL, in case of an error | |
178 | **/ | |
f2b93744 | 179 | struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, const char *name) |
1c7047ea KS |
180 | { |
181 | struct udev_monitor *udev_monitor; | |
f2b93744 | 182 | unsigned int group; |
1c7047ea KS |
183 | |
184 | if (udev == NULL) | |
185 | return NULL; | |
f2b93744 KS |
186 | |
187 | if (name == NULL) | |
1e03b754 | 188 | group = UDEV_MONITOR_NONE; |
f2b93744 KS |
189 | else if (strcmp(name, "udev") == 0) |
190 | group = UDEV_MONITOR_UDEV; | |
1e03b754 KS |
191 | else if (strcmp(name, "kernel") == 0) |
192 | group = UDEV_MONITOR_KERNEL; | |
f2b93744 KS |
193 | else |
194 | return NULL; | |
195 | ||
e14bdd88 | 196 | udev_monitor = udev_monitor_new(udev); |
1c7047ea KS |
197 | if (udev_monitor == NULL) |
198 | return NULL; | |
1c7047ea KS |
199 | |
200 | udev_monitor->sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT); | |
201 | if (udev_monitor->sock == -1) { | |
659353f5 | 202 | err(udev, "error getting socket: %m\n"); |
1c7047ea KS |
203 | free(udev_monitor); |
204 | return NULL; | |
205 | } | |
4b09a2fc | 206 | util_set_fd_cloexec(udev_monitor->sock); |
1c7047ea KS |
207 | |
208 | udev_monitor->snl.nl_family = AF_NETLINK; | |
11625409 | 209 | udev_monitor->snl.nl_groups = group; |
1e03b754 KS |
210 | |
211 | /* default destination for sending */ | |
212 | udev_monitor->snl_destination.nl_family = AF_NETLINK; | |
213 | udev_monitor->snl_destination.nl_groups = UDEV_MONITOR_UDEV; | |
1c7047ea | 214 | |
11625409 | 215 | dbg(udev, "monitor %p created with NETLINK_KOBJECT_UEVENT (%u)\n", udev_monitor, group); |
1c7047ea KS |
216 | return udev_monitor; |
217 | } | |
218 | ||
e14bdd88 KS |
219 | static inline void bpf_stmt(struct sock_filter *inss, unsigned int *i, |
220 | unsigned short code, unsigned int data) | |
221 | { | |
222 | struct sock_filter *ins = &inss[*i]; | |
223 | ||
224 | ins->code = code; | |
225 | ins->k = data; | |
226 | (*i)++; | |
227 | } | |
228 | ||
229 | static inline void bpf_jmp(struct sock_filter *inss, unsigned int *i, | |
230 | unsigned short code, unsigned int data, | |
231 | unsigned short jt, unsigned short jf) | |
232 | { | |
233 | struct sock_filter *ins = &inss[*i]; | |
234 | ||
235 | ins->code = code; | |
236 | ins->jt = jt; | |
237 | ins->jf = jf; | |
238 | ins->k = data; | |
239 | (*i)++; | |
240 | } | |
241 | ||
ce1d6d7f KS |
242 | /** |
243 | * udev_monitor_filter_update: | |
244 | * @udev_monitor: monitor | |
245 | * | |
246 | * Update the installed filter. This might only be needed, if the filter was removed or changed. | |
247 | * | |
248 | * Returns: 0 on success, otherwise a negative error value. | |
249 | */ | |
19d7e87c | 250 | int udev_monitor_filter_update(struct udev_monitor *udev_monitor) |
e14bdd88 KS |
251 | { |
252 | static struct sock_filter ins[256]; | |
253 | static struct sock_fprog filter; | |
254 | unsigned int i; | |
255 | struct udev_list_entry *list_entry; | |
256 | int err; | |
257 | ||
258 | if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL) | |
259 | return 0; | |
260 | ||
261 | memset(ins, 0x00, sizeof(ins)); | |
262 | i = 0; | |
263 | ||
dacea9ff | 264 | /* load magic in A */ |
e14bdd88 KS |
265 | bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, magic)); |
266 | /* jump if magic matches */ | |
267 | bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, UDEV_MONITOR_MAGIC, 1, 0); | |
e93c38c3 KS |
268 | /* wrong magic, pass packet */ |
269 | bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff); | |
e14bdd88 | 270 | |
e14bdd88 KS |
271 | /* add all subsystem match values */ |
272 | udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) { | |
c7dff03e | 273 | unsigned int hash; |
e14bdd88 | 274 | |
dacea9ff KS |
275 | /* load filter_subsystem value in A */ |
276 | bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_subsystem)); | |
277 | hash = util_string_hash32(udev_list_entry_get_name(list_entry)); | |
278 | if (udev_list_entry_get_value(list_entry) == NULL) { | |
279 | /* jump if subsystem does not match */ | |
280 | bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1); | |
281 | } else { | |
282 | /* jump if subsystem does not match */ | |
283 | bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 3); | |
284 | ||
285 | /* load filter_devtype value in A */ | |
286 | bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_devtype)); | |
287 | /* jump if value does not match */ | |
288 | hash = util_string_hash32(udev_list_entry_get_value(list_entry)); | |
289 | bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1); | |
290 | } | |
291 | ||
e14bdd88 KS |
292 | /* matched, pass packet */ |
293 | bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff); | |
294 | ||
295 | if (i+1 >= ARRAY_SIZE(ins)) | |
296 | return -1; | |
297 | } | |
298 | /* nothing matched, drop packet */ | |
299 | bpf_stmt(ins, &i, BPF_RET|BPF_K, 0); | |
300 | ||
301 | /* install filter */ | |
302 | filter.len = i; | |
303 | filter.filter = ins; | |
304 | err = setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)); | |
305 | return err; | |
306 | } | |
307 | ||
1e03b754 KS |
308 | int udev_monitor_allow_unicast_sender(struct udev_monitor *udev_monitor, struct udev_monitor *sender) |
309 | { | |
310 | udev_monitor->snl_trusted_sender.nl_pid = sender->snl.nl_pid; | |
311 | return 0; | |
312 | } | |
ce1d6d7f KS |
313 | /** |
314 | * udev_monitor_enable_receiving: | |
315 | * @udev_monitor: the monitor which should receive events | |
316 | * | |
317 | * Binds the @udev_monitor socket to the event source. | |
318 | * | |
319 | * Returns: 0 on success, otherwise a negative error value. | |
320 | */ | |
d59f11e1 KS |
321 | int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor) |
322 | { | |
323 | int err; | |
324 | const int on = 1; | |
325 | ||
e14bdd88 | 326 | if (udev_monitor->sun.sun_family != 0) { |
11625409 KS |
327 | err = bind(udev_monitor->sock, |
328 | (struct sockaddr *)&udev_monitor->sun, udev_monitor->addrlen); | |
e14bdd88 | 329 | } else if (udev_monitor->snl.nl_family != 0) { |
19d7e87c | 330 | udev_monitor_filter_update(udev_monitor); |
e2b362d9 KS |
331 | err = bind(udev_monitor->sock, |
332 | (struct sockaddr *)&udev_monitor->snl, sizeof(struct sockaddr_nl)); | |
1e03b754 KS |
333 | if (err == 0) { |
334 | struct sockaddr_nl snl; | |
335 | socklen_t addrlen; | |
336 | ||
337 | /* | |
338 | * get the address the kernel has assigned us | |
339 | * it is usually, but not neccessarily the pid | |
340 | */ | |
341 | addrlen = sizeof(struct sockaddr_nl); | |
342 | err = getsockname(udev_monitor->sock, (struct sockaddr *)&snl, &addrlen); | |
343 | if (err == 0) | |
344 | udev_monitor->snl.nl_pid = snl.nl_pid; | |
345 | } | |
e14bdd88 | 346 | } else { |
e2b362d9 | 347 | return -EINVAL; |
e14bdd88 | 348 | } |
e2b362d9 KS |
349 | |
350 | if (err < 0) { | |
351 | err(udev_monitor->udev, "bind failed: %m\n"); | |
352 | return err; | |
ba6929f6 | 353 | } |
e2b362d9 KS |
354 | |
355 | /* enable receiving of sender credentials */ | |
356 | setsockopt(udev_monitor->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); | |
d59f11e1 | 357 | return 0; |
ba6929f6 KS |
358 | } |
359 | ||
cb25a958 KS |
360 | int udev_monitor_set_receive_buffer_size(struct udev_monitor *udev_monitor, int size) |
361 | { | |
362 | if (udev_monitor == NULL) | |
363 | return -1; | |
364 | return setsockopt(udev_monitor->sock, SOL_SOCKET, SO_RCVBUFFORCE, &size, sizeof(size)); | |
365 | } | |
366 | ||
1e03b754 KS |
367 | int udev_monitor_disconnect(struct udev_monitor *udev_monitor) |
368 | { | |
369 | int err; | |
370 | ||
371 | err = close(udev_monitor->sock); | |
372 | udev_monitor->sock = -1; | |
373 | return err; | |
374 | } | |
375 | ||
7d8787b3 KS |
376 | /** |
377 | * udev_monitor_ref: | |
378 | * @udev_monitor: udev monitor | |
379 | * | |
380 | * Take a reference of a udev monitor. | |
381 | * | |
382 | * Returns: the passed udev monitor | |
383 | **/ | |
ba6929f6 KS |
384 | struct udev_monitor *udev_monitor_ref(struct udev_monitor *udev_monitor) |
385 | { | |
386 | if (udev_monitor == NULL) | |
387 | return NULL; | |
388 | udev_monitor->refcount++; | |
389 | return udev_monitor; | |
390 | } | |
391 | ||
7d8787b3 KS |
392 | /** |
393 | * udev_monitor_unref: | |
394 | * @udev_monitor: udev monitor | |
395 | * | |
ff109b8d | 396 | * Drop a reference of a udev monitor. If the refcount reaches zero, |
be7de409 | 397 | * the bound socket will be closed, and the resources of the monitor |
7d8787b3 KS |
398 | * will be released. |
399 | * | |
400 | **/ | |
ba6929f6 KS |
401 | void udev_monitor_unref(struct udev_monitor *udev_monitor) |
402 | { | |
403 | if (udev_monitor == NULL) | |
404 | return; | |
405 | udev_monitor->refcount--; | |
406 | if (udev_monitor->refcount > 0) | |
407 | return; | |
d59f11e1 KS |
408 | if (udev_monitor->sock >= 0) |
409 | close(udev_monitor->sock); | |
e14bdd88 | 410 | udev_list_cleanup_entries(udev_monitor->udev, &udev_monitor->filter_subsystem_list); |
86b57788 | 411 | dbg(udev_monitor->udev, "monitor %p released\n", udev_monitor); |
ba6929f6 KS |
412 | free(udev_monitor); |
413 | } | |
414 | ||
7d8787b3 KS |
415 | /** |
416 | * udev_monitor_get_udev: | |
417 | * @udev_monitor: udev monitor | |
418 | * | |
b98fd840 | 419 | * Retrieve the udev library context the monitor was created with. |
7d8787b3 KS |
420 | * |
421 | * Returns: the udev library context | |
422 | **/ | |
ba6929f6 KS |
423 | struct udev *udev_monitor_get_udev(struct udev_monitor *udev_monitor) |
424 | { | |
425 | if (udev_monitor == NULL) | |
426 | return NULL; | |
427 | return udev_monitor->udev; | |
428 | } | |
429 | ||
7d8787b3 KS |
430 | /** |
431 | * udev_monitor_get_fd: | |
432 | * @udev_monitor: udev monitor | |
433 | * | |
434 | * Retrieve the socket file descriptor associated with the monitor. | |
435 | * | |
436 | * Returns: the socket file descriptor | |
437 | **/ | |
ba6929f6 KS |
438 | int udev_monitor_get_fd(struct udev_monitor *udev_monitor) |
439 | { | |
440 | if (udev_monitor == NULL) | |
441 | return -1; | |
d59f11e1 | 442 | return udev_monitor->sock; |
ba6929f6 KS |
443 | } |
444 | ||
e14bdd88 KS |
445 | static int passes_filter(struct udev_monitor *udev_monitor, struct udev_device *udev_device) |
446 | { | |
447 | struct udev_list_entry *list_entry; | |
e14bdd88 KS |
448 | |
449 | if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL) | |
450 | return 1; | |
451 | ||
452 | udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) { | |
dacea9ff KS |
453 | const char *subsys = udev_list_entry_get_name(list_entry); |
454 | const char *dsubsys = udev_device_get_subsystem(udev_device); | |
455 | const char *devtype; | |
456 | const char *ddevtype; | |
e14bdd88 | 457 | |
dacea9ff KS |
458 | if (strcmp(dsubsys, subsys) != 0) |
459 | continue; | |
460 | ||
461 | devtype = udev_list_entry_get_value(list_entry); | |
462 | if (devtype == NULL) | |
463 | return 1; | |
464 | ddevtype = udev_device_get_devtype(udev_device); | |
465 | if (ddevtype == NULL) | |
466 | continue; | |
467 | if (strcmp(ddevtype, devtype) == 0) | |
468 | return 1; | |
e14bdd88 | 469 | } |
dacea9ff | 470 | return 0; |
e14bdd88 KS |
471 | } |
472 | ||
7d8787b3 | 473 | /** |
d59f11e1 | 474 | * udev_monitor_receive_device: |
7d8787b3 KS |
475 | * @udev_monitor: udev monitor |
476 | * | |
d59f11e1 | 477 | * Receive data from the udev monitor socket, allocate a new udev |
b98fd840 | 478 | * device, fill in the received data, and return the device. |
7d8787b3 KS |
479 | * |
480 | * Only socket connections with uid=0 are accepted. The caller | |
be7de409 AJ |
481 | * needs to make sure that there is data to read from the socket. |
482 | * The call will block until the socket becomes readable. | |
7d8787b3 KS |
483 | * |
484 | * The initial refcount is 1, and needs to be decremented to | |
be7de409 | 485 | * release the resources of the udev device. |
7d8787b3 KS |
486 | * |
487 | * Returns: a new udev device, or #NULL, in case of an error | |
488 | **/ | |
d59f11e1 | 489 | struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monitor) |
ba6929f6 KS |
490 | { |
491 | struct udev_device *udev_device; | |
492 | struct msghdr smsg; | |
ba6929f6 | 493 | struct iovec iov; |
ba6929f6 | 494 | char cred_msg[CMSG_SPACE(sizeof(struct ucred))]; |
e2b362d9 | 495 | struct cmsghdr *cmsg; |
e86a923d | 496 | struct sockaddr_nl snl; |
e2b362d9 | 497 | struct ucred *cred; |
c7dff03e KS |
498 | char buf[8192]; |
499 | ssize_t buflen; | |
500 | ssize_t bufpos; | |
e14bdd88 | 501 | struct udev_monitor_netlink_header *nlh; |
81d9e221 | 502 | int devpath_set = 0; |
31f4b036 KS |
503 | int subsystem_set = 0; |
504 | int action_set = 0; | |
37372bbc KS |
505 | int maj = 0; |
506 | int min = 0; | |
ba6929f6 | 507 | |
e14bdd88 | 508 | retry: |
ba6929f6 KS |
509 | if (udev_monitor == NULL) |
510 | return NULL; | |
511 | memset(buf, 0x00, sizeof(buf)); | |
512 | iov.iov_base = &buf; | |
513 | iov.iov_len = sizeof(buf); | |
514 | memset (&smsg, 0x00, sizeof(struct msghdr)); | |
515 | smsg.msg_iov = &iov; | |
516 | smsg.msg_iovlen = 1; | |
517 | smsg.msg_control = cred_msg; | |
518 | smsg.msg_controllen = sizeof(cred_msg); | |
519 | ||
e86a923d SJR |
520 | if (udev_monitor->snl.nl_family != 0) { |
521 | smsg.msg_name = &snl; | |
e14bdd88 | 522 | smsg.msg_namelen = sizeof(snl); |
e86a923d SJR |
523 | } |
524 | ||
c7dff03e KS |
525 | buflen = recvmsg(udev_monitor->sock, &smsg, 0); |
526 | if (buflen < 0) { | |
ba6929f6 | 527 | if (errno != EINTR) |
e86a923d | 528 | info(udev_monitor->udev, "unable to receive message\n"); |
ba6929f6 KS |
529 | return NULL; |
530 | } | |
ba6929f6 | 531 | |
c7dff03e KS |
532 | if (buflen < 32 || (size_t)buflen >= sizeof(buf)) { |
533 | info(udev_monitor->udev, "invalid message length\n"); | |
534 | return NULL; | |
535 | } | |
536 | ||
e86a923d SJR |
537 | if (udev_monitor->snl.nl_family != 0) { |
538 | if (snl.nl_groups == 0) { | |
1e03b754 KS |
539 | /* unicast message, check if we trust the sender */ |
540 | if (udev_monitor->snl_trusted_sender.nl_pid == 0 || | |
541 | snl.nl_pid != udev_monitor->snl_trusted_sender.nl_pid) { | |
542 | info(udev_monitor->udev, "unicast netlink message ignored\n"); | |
543 | return NULL; | |
544 | } | |
545 | } else if (snl.nl_groups == UDEV_MONITOR_KERNEL) { | |
cb14f454 | 546 | if (snl.nl_pid > 0) { |
9cc94b15 KS |
547 | info(udev_monitor->udev, "multicast kernel netlink message from pid %d ignored\n", |
548 | snl.nl_pid); | |
cb14f454 KS |
549 | return NULL; |
550 | } | |
e86a923d SJR |
551 | } |
552 | } | |
553 | ||
e2b362d9 KS |
554 | cmsg = CMSG_FIRSTHDR(&smsg); |
555 | if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) { | |
e86a923d | 556 | info(udev_monitor->udev, "no sender credentials received, message ignored\n"); |
e2b362d9 KS |
557 | return NULL; |
558 | } | |
1c7047ea | 559 | |
e2b362d9 KS |
560 | cred = (struct ucred *)CMSG_DATA(cmsg); |
561 | if (cred->uid != 0) { | |
e86a923d | 562 | info(udev_monitor->udev, "sender uid=%d, message ignored\n", cred->uid); |
e2b362d9 | 563 | return NULL; |
ba6929f6 KS |
564 | } |
565 | ||
c7dff03e KS |
566 | if (strncmp(buf, "udev-", 5) == 0) { |
567 | /* udev message needs proper version magic */ | |
568 | nlh = (struct udev_monitor_netlink_header *) buf; | |
569 | if (nlh->magic != htonl(UDEV_MONITOR_MAGIC)) | |
570 | return NULL; | |
e14bdd88 KS |
571 | if (nlh->properties_off < sizeof(struct udev_monitor_netlink_header)) |
572 | return NULL; | |
93ee84ce | 573 | if (nlh->properties_off+32 > buflen) |
e14bdd88 KS |
574 | return NULL; |
575 | bufpos = nlh->properties_off; | |
576 | } else { | |
577 | /* kernel message with header */ | |
578 | bufpos = strlen(buf) + 1; | |
c7dff03e | 579 | if ((size_t)bufpos < sizeof("a@/d") || bufpos >= buflen) { |
e14bdd88 KS |
580 | info(udev_monitor->udev, "invalid message length\n"); |
581 | return NULL; | |
582 | } | |
ba6929f6 | 583 | |
e14bdd88 KS |
584 | /* check message header */ |
585 | if (strstr(buf, "@/") == NULL) { | |
586 | info(udev_monitor->udev, "unrecognized message header\n"); | |
587 | return NULL; | |
588 | } | |
ba6929f6 KS |
589 | } |
590 | ||
a5710160 | 591 | udev_device = udev_device_new(udev_monitor->udev); |
9cc94b15 | 592 | if (udev_device == NULL) |
ba6929f6 | 593 | return NULL; |
ba6929f6 | 594 | |
c7dff03e | 595 | while (bufpos < buflen) { |
ba6929f6 KS |
596 | char *key; |
597 | size_t keylen; | |
598 | ||
599 | key = &buf[bufpos]; | |
600 | keylen = strlen(key); | |
601 | if (keylen == 0) | |
602 | break; | |
603 | bufpos += keylen + 1; | |
604 | ||
605 | if (strncmp(key, "DEVPATH=", 8) == 0) { | |
8753fadf KS |
606 | char path[UTIL_PATH_SIZE]; |
607 | ||
065db052 | 608 | util_strscpyl(path, sizeof(path), udev_get_sys_path(udev_monitor->udev), &key[8], NULL); |
8cd2e972 | 609 | udev_device_set_syspath(udev_device, path); |
81d9e221 | 610 | devpath_set = 1; |
ba6929f6 | 611 | } else if (strncmp(key, "SUBSYSTEM=", 10) == 0) { |
8cd2e972 | 612 | udev_device_set_subsystem(udev_device, &key[10]); |
31f4b036 | 613 | subsystem_set = 1; |
bf8b2ae1 MH |
614 | } else if (strncmp(key, "DEVTYPE=", 8) == 0) { |
615 | udev_device_set_devtype(udev_device, &key[8]); | |
ba6929f6 | 616 | } else if (strncmp(key, "DEVNAME=", 8) == 0) { |
9cc94b15 | 617 | if (key[8] == '/') |
cb14f454 | 618 | udev_device_set_devnode(udev_device, &key[8]); |
9cc94b15 KS |
619 | else |
620 | udev_device_set_knodename(udev_device, &key[8]); | |
ba6929f6 | 621 | } else if (strncmp(key, "DEVLINKS=", 9) == 0) { |
1e61ff54 KS |
622 | char devlinks[UTIL_PATH_SIZE]; |
623 | char *slink; | |
624 | char *next; | |
ba6929f6 | 625 | |
065db052 | 626 | util_strscpy(devlinks, sizeof(devlinks), &key[9]); |
1e61ff54 KS |
627 | slink = devlinks; |
628 | next = strchr(slink, ' '); | |
ba6929f6 KS |
629 | while (next != NULL) { |
630 | next[0] = '\0'; | |
8cd2e972 | 631 | udev_device_add_devlink(udev_device, slink); |
ba6929f6 KS |
632 | slink = &next[1]; |
633 | next = strchr(slink, ' '); | |
634 | } | |
635 | if (slink[0] != '\0') | |
8cd2e972 | 636 | udev_device_add_devlink(udev_device, slink); |
37372bbc | 637 | } else if (strncmp(key, "DRIVER=", 7) == 0) { |
8cd2e972 | 638 | udev_device_set_driver(udev_device, &key[7]); |
37372bbc | 639 | } else if (strncmp(key, "ACTION=", 7) == 0) { |
8cd2e972 | 640 | udev_device_set_action(udev_device, &key[7]); |
31f4b036 | 641 | action_set = 1; |
37372bbc KS |
642 | } else if (strncmp(key, "MAJOR=", 6) == 0) { |
643 | maj = strtoull(&key[6], NULL, 10); | |
644 | } else if (strncmp(key, "MINOR=", 6) == 0) { | |
645 | min = strtoull(&key[6], NULL, 10); | |
646 | } else if (strncmp(key, "DEVPATH_OLD=", 12) == 0) { | |
8cd2e972 | 647 | udev_device_set_devpath_old(udev_device, &key[12]); |
37372bbc | 648 | } else if (strncmp(key, "SEQNUM=", 7) == 0) { |
8cd2e972 | 649 | udev_device_set_seqnum(udev_device, strtoull(&key[7], NULL, 10)); |
37372bbc | 650 | } else if (strncmp(key, "TIMEOUT=", 8) == 0) { |
8cd2e972 | 651 | udev_device_set_timeout(udev_device, strtoull(&key[8], NULL, 10)); |
31f4b036 KS |
652 | } else { |
653 | udev_device_add_property_from_string(udev_device, key); | |
654 | } | |
ba6929f6 | 655 | } |
31f4b036 KS |
656 | if (!devpath_set || !subsystem_set || !action_set) { |
657 | info(udev_monitor->udev, "missing values, skip\n"); | |
81d9e221 KS |
658 | udev_device_unref(udev_device); |
659 | return NULL; | |
660 | } | |
e14bdd88 KS |
661 | |
662 | /* skip device, if it does not pass the current filter */ | |
663 | if (!passes_filter(udev_monitor, udev_device)) { | |
664 | struct pollfd pfd[1]; | |
665 | int rc; | |
666 | ||
667 | udev_device_unref(udev_device); | |
668 | ||
669 | /* if something is queued, get next device */ | |
670 | pfd[0].fd = udev_monitor->sock; | |
671 | pfd[0].events = POLLIN; | |
672 | rc = poll(pfd, 1, 0); | |
673 | if (rc > 0) | |
674 | goto retry; | |
675 | return NULL; | |
676 | } | |
677 | ||
3361a0f1 KS |
678 | if (maj > 0) |
679 | udev_device_set_devnum(udev_device, makedev(maj, min)); | |
8cd2e972 | 680 | udev_device_set_info_loaded(udev_device); |
ba6929f6 KS |
681 | return udev_device; |
682 | } | |
9925ab04 | 683 | |
1e03b754 KS |
684 | int udev_monitor_send_device(struct udev_monitor *udev_monitor, |
685 | struct udev_monitor *destination, struct udev_device *udev_device) | |
9925ab04 | 686 | { |
e14bdd88 KS |
687 | struct msghdr smsg; |
688 | struct iovec iov[2]; | |
c2654402 | 689 | const char *buf; |
e14bdd88 | 690 | ssize_t blen; |
9925ab04 KS |
691 | ssize_t count; |
692 | ||
e14bdd88 KS |
693 | blen = udev_device_get_properties_monitor_buf(udev_device, &buf); |
694 | if (blen < 32) | |
3c67f7d2 | 695 | return -1; |
e14bdd88 KS |
696 | |
697 | if (udev_monitor->sun.sun_family != 0) { | |
698 | const char *action; | |
699 | char header[2048]; | |
065db052 | 700 | char *s; |
e14bdd88 KS |
701 | |
702 | /* header <action>@<devpath> */ | |
703 | action = udev_device_get_action(udev_device); | |
704 | if (action == NULL) | |
705 | return -EINVAL; | |
065db052 KS |
706 | s = header; |
707 | if (util_strpcpyl(&s, sizeof(header), action, "@", udev_device_get_devpath(udev_device), NULL) == 0) | |
e14bdd88 KS |
708 | return -EINVAL; |
709 | iov[0].iov_base = header; | |
065db052 | 710 | iov[0].iov_len = (s - header)+1; |
e14bdd88 KS |
711 | |
712 | /* add properties list */ | |
713 | iov[1].iov_base = (char *)buf; | |
714 | iov[1].iov_len = blen; | |
715 | ||
716 | memset(&smsg, 0x00, sizeof(struct msghdr)); | |
717 | smsg.msg_iov = iov; | |
718 | smsg.msg_iovlen = 2; | |
719 | smsg.msg_name = &udev_monitor->sun; | |
720 | smsg.msg_namelen = udev_monitor->addrlen; | |
721 | } else if (udev_monitor->snl.nl_family != 0) { | |
722 | const char *val; | |
e14bdd88 KS |
723 | struct udev_monitor_netlink_header nlh; |
724 | ||
725 | ||
726 | /* add versioned header */ | |
727 | memset(&nlh, 0x00, sizeof(struct udev_monitor_netlink_header)); | |
065db052 | 728 | util_strscpy(nlh.version, sizeof(nlh.version), "udev-" VERSION); |
e14bdd88 KS |
729 | nlh.magic = htonl(UDEV_MONITOR_MAGIC); |
730 | val = udev_device_get_subsystem(udev_device); | |
c7dff03e | 731 | nlh.filter_subsystem = htonl(util_string_hash32(val)); |
dacea9ff KS |
732 | val = udev_device_get_devtype(udev_device); |
733 | if (val != NULL) | |
734 | nlh.filter_devtype = htonl(util_string_hash32(val)); | |
e14bdd88 KS |
735 | iov[0].iov_base = &nlh; |
736 | iov[0].iov_len = sizeof(struct udev_monitor_netlink_header); | |
737 | ||
738 | /* add properties list */ | |
739 | nlh.properties_off = iov[0].iov_len; | |
740 | nlh.properties_len = blen; | |
741 | iov[1].iov_base = (char *)buf; | |
742 | iov[1].iov_len = blen; | |
743 | ||
744 | memset(&smsg, 0x00, sizeof(struct msghdr)); | |
745 | smsg.msg_iov = iov; | |
746 | smsg.msg_iovlen = 2; | |
1e03b754 KS |
747 | /* |
748 | * Use custom address for target, or the default one. | |
749 | * | |
750 | * If we send to a muticast group, we will get | |
751 | * ECONNREFUSED, which is expected. | |
752 | */ | |
753 | if (destination != NULL) | |
754 | smsg.msg_name = &destination->snl; | |
755 | else | |
756 | smsg.msg_name = &udev_monitor->snl_destination; | |
e14bdd88 KS |
757 | smsg.msg_namelen = sizeof(struct sockaddr_nl); |
758 | } else { | |
e2b362d9 | 759 | return -1; |
e14bdd88 | 760 | } |
e2b362d9 | 761 | |
e14bdd88 | 762 | count = sendmsg(udev_monitor->sock, &smsg, 0); |
e86a923d | 763 | info(udev_monitor->udev, "passed %zi bytes to monitor %p\n", count, udev_monitor); |
9925ab04 KS |
764 | return count; |
765 | } | |
e14bdd88 | 766 | |
ce1d6d7f KS |
767 | /** |
768 | * udev_monitor_filter_add_match_subsystem_devtype: | |
769 | * @udev_monitor: the monitor | |
770 | * @subsystem: the subsystem value to match the incoming devices against | |
771 | * @devtype: the devtype value to matvh the incoming devices against | |
772 | * | |
773 | * The filter must be installed before the monitor is switched to listening mode. | |
774 | * | |
775 | * Returns: 0 on success, otherwise a negative error value. | |
776 | */ | |
dacea9ff | 777 | int udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_monitor, const char *subsystem, const char *devtype) |
e14bdd88 KS |
778 | { |
779 | if (udev_monitor == NULL) | |
780 | return -EINVAL; | |
781 | if (subsystem == NULL) | |
782 | return 0; | |
783 | if (udev_list_entry_add(udev_monitor->udev, | |
dacea9ff | 784 | &udev_monitor->filter_subsystem_list, subsystem, devtype, 0, 0) == NULL) |
e14bdd88 KS |
785 | return -ENOMEM; |
786 | return 0; | |
787 | } | |
08a7a795 | 788 | |
ce1d6d7f KS |
789 | /** |
790 | * udev_monitor_filter_remove: | |
791 | * @udev_monitor: monitor | |
792 | * | |
793 | * Remove all filters from monitor. | |
794 | * | |
795 | * Returns: 0 on success, otherwise a negative error value. | |
796 | */ | |
08a7a795 KS |
797 | int udev_monitor_filter_remove(struct udev_monitor *udev_monitor) |
798 | { | |
799 | static struct sock_fprog filter = { 0, NULL }; | |
800 | ||
801 | udev_list_cleanup_entries(udev_monitor->udev, &udev_monitor->filter_subsystem_list); | |
802 | return setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)); | |
803 | } |