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Commit | Line | Data |
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7fafc032 | 1 | /* |
53921bfa | 2 | * udevd.c - hotplug event serializer |
7fafc032 | 3 | * |
7fafc032 | 4 | * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> |
2f6cbd19 | 5 | * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca> |
7fafc032 KS |
6 | * |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the | |
10 | * Free Software Foundation version 2 of the License. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, but | |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License along | |
18 | * with this program; if not, write to the Free Software Foundation, Inc., | |
19 | * 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | * | |
21 | */ | |
22 | ||
a695feae | 23 | #include <stddef.h> |
90c210eb | 24 | #include <sys/wait.h> |
7fafc032 KS |
25 | #include <signal.h> |
26 | #include <unistd.h> | |
27 | #include <errno.h> | |
28 | #include <stdio.h> | |
29 | #include <stdlib.h> | |
30 | #include <string.h> | |
a695feae | 31 | #include <time.h> |
53921bfa KS |
32 | #include <sys/types.h> |
33 | #include <sys/socket.h> | |
34 | #include <sys/un.h> | |
2f6cbd19 | 35 | #include <sys/time.h> |
7fafc032 | 36 | |
a695feae | 37 | #include "list.h" |
7fafc032 | 38 | #include "udev.h" |
35b7d88c | 39 | #include "udev_version.h" |
7fafc032 KS |
40 | #include "udevd.h" |
41 | #include "logging.h" | |
42 | ||
53921bfa | 43 | static int expected_seqnum = 0; |
2f6cbd19 KS |
44 | volatile static int children_waiting; |
45 | volatile static int msg_q_timeout; | |
7fafc032 | 46 | |
a695feae | 47 | LIST_HEAD(msg_list); |
53921bfa | 48 | LIST_HEAD(exec_list); |
35b7d88c | 49 | LIST_HEAD(running_list); |
7fafc032 | 50 | |
2f6cbd19 KS |
51 | static void exec_queue_manager(void); |
52 | static void msg_queue_manager(void); | |
7fafc032 | 53 | |
51a8bb2f GKH |
54 | unsigned char logname[42]; |
55 | ||
56 | int log_ok(void) | |
57 | { | |
58 | return 1; | |
59 | } | |
60 | ||
53921bfa | 61 | static void msg_dump_queue(void) |
7fafc032 | 62 | { |
53921bfa | 63 | struct hotplug_msg *msg; |
7fafc032 | 64 | |
53921bfa KS |
65 | list_for_each_entry(msg, &msg_list, list) |
66 | dbg("sequence %d in queue", msg->seqnum); | |
35b7d88c KS |
67 | } |
68 | ||
53921bfa | 69 | static void msg_dump(struct hotplug_msg *msg) |
35b7d88c | 70 | { |
53921bfa KS |
71 | dbg("sequence %d, '%s', '%s', '%s'", |
72 | msg->seqnum, msg->action, msg->devpath, msg->subsystem); | |
35b7d88c KS |
73 | } |
74 | ||
53921bfa | 75 | static struct hotplug_msg *msg_create(void) |
35b7d88c | 76 | { |
53921bfa | 77 | struct hotplug_msg *new_msg; |
35b7d88c | 78 | |
53921bfa | 79 | new_msg = malloc(sizeof(struct hotplug_msg)); |
2f6cbd19 | 80 | if (new_msg == NULL) |
53921bfa | 81 | dbg("error malloc"); |
53921bfa | 82 | return new_msg; |
35b7d88c KS |
83 | } |
84 | ||
2f6cbd19 | 85 | static void run_queue_delete(struct hotplug_msg *msg) |
8e2229c4 | 86 | { |
2f6cbd19 KS |
87 | list_del(&msg->list); |
88 | free(msg); | |
89 | exec_queue_manager(); | |
8e2229c4 KS |
90 | } |
91 | ||
53921bfa KS |
92 | /* orders the message in the queue by sequence number */ |
93 | static void msg_queue_insert(struct hotplug_msg *msg) | |
35b7d88c | 94 | { |
53921bfa | 95 | struct hotplug_msg *loop_msg; |
35b7d88c | 96 | |
53921bfa KS |
97 | /* sort message by sequence number into list*/ |
98 | list_for_each_entry(loop_msg, &msg_list, list) | |
99 | if (loop_msg->seqnum > msg->seqnum) | |
100 | break; | |
101 | list_add_tail(&msg->list, &loop_msg->list); | |
102 | dbg("queued message seq %d", msg->seqnum); | |
35b7d88c | 103 | |
53921bfa KS |
104 | /* store timestamp of queuing */ |
105 | msg->queue_time = time(NULL); | |
35b7d88c | 106 | |
2f6cbd19 KS |
107 | /* run msg queue manager */ |
108 | msg_queue_manager(); | |
7fafc032 | 109 | |
53921bfa | 110 | return ; |
7fafc032 KS |
111 | } |
112 | ||
53921bfa | 113 | /* forks event and removes event from run queue when finished */ |
2f6cbd19 | 114 | static void udev_run(struct hotplug_msg *msg) |
7fafc032 | 115 | { |
90c210eb | 116 | pid_t pid; |
a695feae KS |
117 | setenv("ACTION", msg->action, 1); |
118 | setenv("DEVPATH", msg->devpath, 1); | |
90c210eb KS |
119 | |
120 | pid = fork(); | |
121 | switch (pid) { | |
122 | case 0: | |
33db4b8d | 123 | /* child */ |
35b7d88c | 124 | execl(UDEV_BIN, "udev", msg->subsystem, NULL); |
33db4b8d KS |
125 | dbg("exec of child failed"); |
126 | exit(1); | |
90c210eb KS |
127 | break; |
128 | case -1: | |
33db4b8d | 129 | dbg("fork of child failed"); |
2f6cbd19 KS |
130 | run_queue_delete(msg); |
131 | break; | |
90c210eb | 132 | default: |
2f6cbd19 KS |
133 | /* get SIGCHLD in main loop */ |
134 | dbg("==> exec seq %d [%d] working at '%s'", msg->seqnum, pid, msg->devpath); | |
135 | msg->pid = pid; | |
90c210eb | 136 | } |
7fafc032 KS |
137 | } |
138 | ||
53921bfa KS |
139 | /* returns already running task with devpath */ |
140 | static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg) | |
7fafc032 | 141 | { |
53921bfa | 142 | struct hotplug_msg *loop_msg; |
2f6cbd19 | 143 | list_for_each_entry(loop_msg, &running_list, list) |
53921bfa KS |
144 | if (strncmp(loop_msg->devpath, msg->devpath, sizeof(loop_msg->devpath)) == 0) |
145 | return loop_msg; | |
146 | return NULL; | |
7fafc032 KS |
147 | } |
148 | ||
2f6cbd19 KS |
149 | /* exec queue management routine executes the events and delays events for the same devpath */ |
150 | static void exec_queue_manager() | |
7fafc032 | 151 | { |
53921bfa KS |
152 | struct hotplug_msg *loop_msg; |
153 | struct hotplug_msg *tmp_msg; | |
a695feae | 154 | struct hotplug_msg *msg; |
53921bfa | 155 | |
2f6cbd19 KS |
156 | list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) { |
157 | msg = running_with_devpath(loop_msg); | |
158 | if (!msg) { | |
159 | /* move event to run list */ | |
160 | list_move_tail(&loop_msg->list, &running_list); | |
161 | udev_run(loop_msg); | |
162 | dbg("moved seq %d to running list", loop_msg->seqnum); | |
163 | } else { | |
164 | dbg("delay seq %d, cause seq %d already working on '%s'", | |
165 | loop_msg->seqnum, msg->seqnum, msg->devpath); | |
53921bfa | 166 | } |
53921bfa KS |
167 | } |
168 | } | |
169 | ||
2f6cbd19 | 170 | static void msg_move_exec(struct hotplug_msg *msg) |
86590cd5 | 171 | { |
2f6cbd19 KS |
172 | list_move_tail(&msg->list, &exec_list); |
173 | exec_queue_manager(); | |
174 | expected_seqnum = msg->seqnum+1; | |
175 | dbg("moved seq %d to exec, next expected is %d", | |
176 | msg->seqnum, expected_seqnum); | |
86590cd5 KS |
177 | } |
178 | ||
2f6cbd19 KS |
179 | /* msg queue management routine handles the timeouts and dispatches the events */ |
180 | static void msg_queue_manager() | |
53921bfa KS |
181 | { |
182 | struct hotplug_msg *loop_msg; | |
a695feae | 183 | struct hotplug_msg *tmp_msg; |
53921bfa | 184 | time_t msg_age = 0; |
a695feae | 185 | |
2f6cbd19 | 186 | dbg("msg queue manager, next expected is %d", expected_seqnum); |
a695feae | 187 | recheck: |
2f6cbd19 KS |
188 | list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) { |
189 | /* move event with expected sequence to the exec list */ | |
190 | if (loop_msg->seqnum == expected_seqnum) { | |
191 | msg_move_exec(loop_msg); | |
192 | continue; | |
a695feae | 193 | } |
35b7d88c | 194 | |
2f6cbd19 KS |
195 | /* move event with expired timeout to the exec list */ |
196 | msg_age = time(NULL) - loop_msg->queue_time; | |
197 | if (msg_age > EVENT_TIMEOUT_SEC-1) { | |
198 | msg_move_exec(loop_msg); | |
199 | goto recheck; | |
53921bfa | 200 | } else { |
2f6cbd19 | 201 | break; |
53921bfa | 202 | } |
2f6cbd19 KS |
203 | } |
204 | ||
205 | msg_dump_queue(); | |
206 | ||
207 | if (list_empty(&msg_list) == 0) { | |
208 | /* set timeout for remaining queued events */ | |
209 | struct itimerval itv = {{0, 0}, {EVENT_TIMEOUT_SEC - msg_age, 0}}; | |
210 | dbg("next event expires in %li seconds", | |
211 | EVENT_TIMEOUT_SEC - msg_age); | |
212 | setitimer(ITIMER_REAL, &itv, 0); | |
7fafc032 | 213 | } |
7fafc032 KS |
214 | } |
215 | ||
2f6cbd19 KS |
216 | /* receive the msg, do some basic sanity checks, and queue it */ |
217 | static void handle_msg(int sock) | |
7fafc032 | 218 | { |
53921bfa KS |
219 | struct hotplug_msg *msg; |
220 | int retval; | |
a695feae | 221 | |
53921bfa KS |
222 | msg = msg_create(); |
223 | if (msg == NULL) { | |
224 | dbg("unable to store message"); | |
2f6cbd19 | 225 | return; |
7fafc032 | 226 | } |
7fafc032 | 227 | |
53921bfa KS |
228 | retval = recv(sock, msg, sizeof(struct hotplug_msg), 0); |
229 | if (retval < 0) { | |
2f6cbd19 KS |
230 | if (errno != EINTR) |
231 | dbg("unable to receive message"); | |
232 | return; | |
53921bfa | 233 | } |
2f6cbd19 | 234 | |
53921bfa KS |
235 | if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) { |
236 | dbg("message magic '%s' doesn't match, ignore it", msg->magic); | |
2f6cbd19 KS |
237 | free(msg); |
238 | return; | |
53921bfa | 239 | } |
a695feae | 240 | |
86590cd5 | 241 | /* if no seqnum is given, we move straight to exec queue */ |
2f6cbd19 | 242 | if (msg->seqnum == -1) { |
86590cd5 | 243 | list_add(&msg->list, &exec_list); |
2f6cbd19 | 244 | exec_queue_manager(); |
86590cd5 | 245 | } else { |
86590cd5 | 246 | msg_queue_insert(msg); |
86590cd5 | 247 | } |
a695feae | 248 | } |
1c5c245e | 249 | |
53921bfa | 250 | static void sig_handler(int signum) |
7fafc032 | 251 | { |
53921bfa KS |
252 | switch (signum) { |
253 | case SIGINT: | |
254 | case SIGTERM: | |
53921bfa KS |
255 | exit(20 + signum); |
256 | break; | |
2f6cbd19 KS |
257 | case SIGALRM: |
258 | msg_q_timeout = 1; | |
259 | break; | |
260 | case SIGCHLD: | |
261 | children_waiting = 1; | |
262 | break; | |
53921bfa KS |
263 | default: |
264 | dbg("unhandled signal"); | |
7fafc032 | 265 | } |
33db4b8d | 266 | } |
7fafc032 | 267 | |
2f6cbd19 KS |
268 | static void udev_done(int pid) |
269 | { | |
270 | /* find msg associated with pid and delete it */ | |
271 | struct hotplug_msg *msg; | |
272 | ||
273 | list_for_each_entry(msg, &running_list, list) { | |
274 | if (msg->pid == pid) { | |
275 | dbg("<== exec seq %d came back", msg->seqnum); | |
276 | run_queue_delete(msg); | |
277 | return; | |
278 | } | |
279 | } | |
280 | } | |
281 | ||
33db4b8d KS |
282 | int main(int argc, char *argv[]) |
283 | { | |
53921bfa | 284 | int ssock; |
53921bfa | 285 | struct sockaddr_un saddr; |
1dadabd7 | 286 | socklen_t addrlen; |
53921bfa KS |
287 | int retval; |
288 | ||
95a6f4c8 GKH |
289 | init_logging("udevd"); |
290 | ||
7fafc032 KS |
291 | signal(SIGINT, sig_handler); |
292 | signal(SIGTERM, sig_handler); | |
2f6cbd19 KS |
293 | signal(SIGALRM, sig_handler); |
294 | signal(SIGCHLD, sig_handler); | |
295 | ||
296 | /* we want these two to interrupt system calls */ | |
297 | siginterrupt(SIGALRM, 1); | |
298 | siginterrupt(SIGCHLD, 1); | |
7fafc032 | 299 | |
53921bfa KS |
300 | memset(&saddr, 0x00, sizeof(saddr)); |
301 | saddr.sun_family = AF_LOCAL; | |
872344c4 KS |
302 | /* use abstract namespace for socket path */ |
303 | strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH); | |
1dadabd7 | 304 | addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1; |
53921bfa | 305 | |
2f6cbd19 | 306 | ssock = socket(AF_LOCAL, SOCK_DGRAM, 0); |
53921bfa KS |
307 | if (ssock == -1) { |
308 | dbg("error getting socket"); | |
309 | exit(1); | |
310 | } | |
311 | ||
2f6cbd19 | 312 | /* the bind takes care of ensuring only one copy running */ |
1dadabd7 | 313 | retval = bind(ssock, &saddr, addrlen); |
53921bfa KS |
314 | if (retval < 0) { |
315 | dbg("bind failed\n"); | |
316 | goto exit; | |
317 | } | |
318 | ||
2f6cbd19 KS |
319 | while (1) { |
320 | handle_msg(ssock); | |
53921bfa | 321 | |
2f6cbd19 KS |
322 | while(msg_q_timeout) { |
323 | msg_q_timeout = 0; | |
324 | msg_queue_manager(); | |
325 | } | |
53921bfa | 326 | |
2f6cbd19 KS |
327 | while(children_waiting) { |
328 | children_waiting = 0; | |
329 | /* reap all dead children */ | |
330 | while(1) { | |
331 | int pid = waitpid(-1, 0, WNOHANG); | |
332 | if ((pid == -1) || (pid == 0)) | |
333 | break; | |
334 | udev_done(pid); | |
335 | } | |
53921bfa | 336 | } |
53921bfa KS |
337 | } |
338 | exit: | |
339 | close(ssock); | |
53921bfa | 340 | exit(1); |
7fafc032 | 341 | } |