summaryrefslogtreecommitdiffstats
path: root/daemon/main.c
diff options
context:
space:
mode:
Diffstat (limited to 'daemon/main.c')
-rw-r--r--daemon/main.c618
1 files changed, 0 insertions, 618 deletions
diff --git a/daemon/main.c b/daemon/main.c
deleted file mode 100644
index 140bee1..0000000
--- a/daemon/main.c
+++ /dev/null
@@ -1,618 +0,0 @@
1/*
2 usbmuxd - iPhone/iPod Touch USB multiplex server daemon
3
4Copyright (C) 2009 Hector Martin "marcan" <hector@marcansoft.com>
5Copyright (C) 2009 Nikias Bassen <nikias@gmx.li>
6Copyright (C) 2009 Paul Sladen <libiphone@paul.sladen.org>
7
8This program is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation, either version 2 or version 3.
11
12This program is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with this program; if not, write to the Free Software
19Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
21*/
22
23#define _BSD_SOURCE
24#define _GNU_SOURCE
25
26#ifdef HAVE_CONFIG_H
27#include <config.h>
28#endif
29
30#include <stdio.h>
31#include <errno.h>
32#include <string.h>
33#include <stdlib.h>
34#include <signal.h>
35#include <unistd.h>
36#include <sys/socket.h>
37#include <sys/un.h>
38#include <sys/stat.h>
39#include <sys/types.h>
40#include <fcntl.h>
41#include <getopt.h>
42#include <pwd.h>
43#include <grp.h>
44
45#include "log.h"
46#include "usb.h"
47#include "device.h"
48#include "client.h"
49
50static const char *socket_path = "/var/run/usbmuxd";
51static const char *lockfile = "/var/run/usbmuxd.pid";
52
53int should_exit;
54int should_discover;
55
56static int verbose = 0;
57static int foreground = 0;
58static int drop_privileges = 0;
59static const char *drop_user = NULL;
60static int opt_udev = 0;
61static int opt_exit = 0;
62static int exit_signal = 0;
63static int daemon_pipe;
64
65static int report_to_parent = 0;
66
67int create_socket(void) {
68 struct sockaddr_un bind_addr;
69 int listenfd;
70
71 if(unlink(socket_path) == -1 && errno != ENOENT) {
72 usbmuxd_log(LL_FATAL, "unlink(%s) failed: %s", socket_path, strerror(errno));
73 return -1;
74 }
75
76 listenfd = socket(AF_UNIX, SOCK_STREAM, 0);
77 if (listenfd == -1) {
78 usbmuxd_log(LL_FATAL, "socket() failed: %s", strerror(errno));
79 return -1;
80 }
81
82 bzero(&bind_addr, sizeof(bind_addr));
83 bind_addr.sun_family = AF_UNIX;
84 strcpy(bind_addr.sun_path, socket_path);
85 if (bind(listenfd, (struct sockaddr*)&bind_addr, sizeof(bind_addr)) != 0) {
86 usbmuxd_log(LL_FATAL, "bind() failed: %s", strerror(errno));
87 return -1;
88 }
89
90 // Start listening
91 if (listen(listenfd, 5) != 0) {
92 usbmuxd_log(LL_FATAL, "listen() failed: %s", strerror(errno));
93 return -1;
94 }
95
96 chmod(socket_path, 0666);
97
98 return listenfd;
99}
100
101void handle_signal(int sig)
102{
103 if (sig != SIGUSR1 && sig != SIGUSR2) {
104 usbmuxd_log(LL_NOTICE,"Caught signal %d, exiting", sig);
105 should_exit = 1;
106 } else {
107 if(opt_udev) {
108 if (sig == SIGUSR1) {
109 usbmuxd_log(LL_INFO, "Caught SIGUSR1, checking if we can terminate (no more devices attached)...");
110 if (device_get_count() > 0) {
111 // we can't quit, there are still devices attached.
112 usbmuxd_log(LL_NOTICE, "Refusing to terminate, there are still devices attached. Kill me with signal 15 (TERM) to force quit.");
113 } else {
114 // it's safe to quit
115 should_exit = 1;
116 }
117 } else if (sig == SIGUSR2) {
118 usbmuxd_log(LL_INFO, "Caught SIGUSR2, scheduling device discovery");
119 should_discover = 1;
120 }
121 } else {
122 usbmuxd_log(LL_INFO, "Caught SIGUSR1/2 but we weren't started in --udev mode, ignoring");
123 }
124 }
125}
126
127void set_signal_handlers(void)
128{
129 struct sigaction sa;
130 sigset_t set;
131
132 // Mask all signals we handle. They will be unmasked by ppoll().
133 sigemptyset(&set);
134 sigaddset(&set, SIGINT);
135 sigaddset(&set, SIGQUIT);
136 sigaddset(&set, SIGTERM);
137 sigaddset(&set, SIGUSR1);
138 sigaddset(&set, SIGUSR2);
139 sigprocmask(SIG_SETMASK, &set, NULL);
140
141 memset(&sa, 0, sizeof(struct sigaction));
142 sa.sa_handler = handle_signal;
143 sigaction(SIGINT, &sa, NULL);
144 sigaction(SIGQUIT, &sa, NULL);
145 sigaction(SIGTERM, &sa, NULL);
146 sigaction(SIGUSR1, &sa, NULL);
147 sigaction(SIGUSR2, &sa, NULL);
148}
149
150#if defined(__FreeBSD__) || defined(__APPLE__)
151static int ppoll(struct pollfd *fds, nfds_t nfds, const struct timespec *timeout, const sigset_t *sigmask)
152{
153 int ready;
154 sigset_t origmask;
155 int to = timeout->tv_sec*1000 + timeout->tv_nsec/1000000;
156
157 sigprocmask(SIG_SETMASK, sigmask, &origmask);
158 ready = poll(fds, nfds, to);
159 sigprocmask(SIG_SETMASK, &origmask, NULL);
160
161 return ready;
162}
163#endif
164
165int main_loop(int listenfd)
166{
167 int to, cnt, i, dto;
168 struct fdlist pollfds;
169 struct timespec tspec;
170
171 sigset_t empty_sigset;
172 sigemptyset(&empty_sigset); // unmask all signals
173
174 fdlist_create(&pollfds);
175 while(!should_exit) {
176 usbmuxd_log(LL_FLOOD, "main_loop iteration");
177 to = usb_get_timeout();
178 usbmuxd_log(LL_FLOOD, "USB timeout is %d ms", to);
179 dto = device_get_timeout();
180 usbmuxd_log(LL_FLOOD, "Device timeout is %d ms", to);
181 if(dto < to)
182 to = dto;
183
184 fdlist_reset(&pollfds);
185 fdlist_add(&pollfds, FD_LISTEN, listenfd, POLLIN);
186 usb_get_fds(&pollfds);
187 client_get_fds(&pollfds);
188 usbmuxd_log(LL_FLOOD, "fd count is %d", pollfds.count);
189
190 tspec.tv_sec = to / 1000;
191 tspec.tv_nsec = (to % 1000) * 1000000;
192 cnt = ppoll(pollfds.fds, pollfds.count, &tspec, &empty_sigset);
193 usbmuxd_log(LL_FLOOD, "poll() returned %d", cnt);
194 if(cnt == -1) {
195 if(errno == EINTR) {
196 if(should_exit) {
197 usbmuxd_log(LL_INFO, "Event processing interrupted");
198 break;
199 }
200 if(should_discover) {
201 should_discover = 0;
202 usbmuxd_log(LL_INFO, "Device discovery triggered by udev");
203 usb_discover();
204 }
205 }
206 } else if(cnt == 0) {
207 if(usb_process() < 0) {
208 usbmuxd_log(LL_FATAL, "usb_process() failed");
209 fdlist_free(&pollfds);
210 return -1;
211 }
212 device_check_timeouts();
213 } else {
214 int done_usb = 0;
215 for(i=0; i<pollfds.count; i++) {
216 if(pollfds.fds[i].revents) {
217 if(!done_usb && pollfds.owners[i] == FD_USB) {
218 if(usb_process() < 0) {
219 usbmuxd_log(LL_FATAL, "usb_process() failed");
220 fdlist_free(&pollfds);
221 return -1;
222 }
223 done_usb = 1;
224 }
225 if(pollfds.owners[i] == FD_LISTEN) {
226 if(client_accept(listenfd) < 0) {
227 usbmuxd_log(LL_FATAL, "client_accept() failed");
228 fdlist_free(&pollfds);
229 return -1;
230 }
231 }
232 if(pollfds.owners[i] == FD_CLIENT) {
233 client_process(pollfds.fds[i].fd, pollfds.fds[i].revents);
234 }
235 }
236 }
237 }
238 }
239 fdlist_free(&pollfds);
240 return 0;
241}
242
243/**
244 * make this program run detached from the current console
245 */
246static int daemonize(void)
247{
248 pid_t pid;
249 pid_t sid;
250 int pfd[2];
251 int res;
252
253 // already a daemon
254 if (getppid() == 1)
255 return 0;
256
257 if((res = pipe(pfd)) < 0) {
258 usbmuxd_log(LL_FATAL, "pipe() failed.");
259 return res;
260 }
261
262 pid = fork();
263 if (pid < 0) {
264 usbmuxd_log(LL_FATAL, "fork() failed.");
265 return pid;
266 }
267
268 if (pid > 0) {
269 // exit parent process
270 int status;
271 close(pfd[1]);
272
273 if((res = read(pfd[0],&status,sizeof(int))) != sizeof(int)) {
274 fprintf(stderr, "usbmuxd: ERROR: Failed to get init status from child, check syslog for messages.\n");
275 exit(1);
276 }
277 if(status != 0)
278 fprintf(stderr, "usbmuxd: ERROR: Child process exited with error %d, check syslog for messages.\n", status);
279 exit(status);
280 }
281 // At this point we are executing as the child process
282 // but we need to do one more fork
283
284 daemon_pipe = pfd[1];
285 close(pfd[0]);
286 report_to_parent = 1;
287
288 // Change the file mode mask
289 umask(0);
290
291 // Create a new SID for the child process
292 sid = setsid();
293 if (sid < 0) {
294 usbmuxd_log(LL_FATAL, "setsid() failed.");
295 return -1;
296 }
297
298 pid = fork();
299 if (pid < 0) {
300 usbmuxd_log(LL_FATAL, "fork() failed (second).");
301 return pid;
302 }
303
304 if (pid > 0) {
305 // exit parent process
306 close(daemon_pipe);
307 exit(0);
308 }
309
310 // Change the current working directory.
311 if ((chdir("/")) < 0) {
312 usbmuxd_log(LL_FATAL, "chdir() failed");
313 return -2;
314 }
315 // Redirect standard files to /dev/null
316 if (!freopen("/dev/null", "r", stdin)) {
317 usbmuxd_log(LL_FATAL, "Redirection of stdin failed.");
318 return -3;
319 }
320 if (!freopen("/dev/null", "w", stdout)) {
321 usbmuxd_log(LL_FATAL, "Redirection of stdout failed.");
322 return -3;
323 }
324
325 return 0;
326}
327
328static int notify_parent(int status)
329{
330 int res;
331
332 report_to_parent = 0;
333 if ((res = write(daemon_pipe, &status, sizeof(int))) != sizeof(int)) {
334 usbmuxd_log(LL_FATAL, "Could not notify parent!");
335 if(res >= 0)
336 return -2;
337 else
338 return res;
339 }
340 close(daemon_pipe);
341 if (!freopen("/dev/null", "w", stderr)) {
342 usbmuxd_log(LL_FATAL, "Redirection of stderr failed.");
343 return -1;
344 }
345 return 0;
346}
347
348static void usage()
349{
350 printf("usage: usbmuxd [options]\n");
351 printf("\t-h|--help Print this message.\n");
352 printf("\t-v|--verbose Be verbose (use twice or more to increase).\n");
353 printf("\t-f|--foreground Do not daemonize (implies one -v).\n");
354 printf("\t-U|--user USER Change to this user after startup (needs usb privileges).\n");
355 printf("\t-u|--udev Run in udev operation mode.\n");
356 printf("\t-x|--exit Tell a running instance to exit if there are no devices\n");
357 printf("\t connected (must be in udev mode).\n");
358 printf("\t-X|--force-exit Tell a running instance to exit, even if there are still\n");
359 printf("\t devices connected (always works).\n");
360 printf("\n");
361}
362
363static void parse_opts(int argc, char **argv)
364{
365 static struct option longopts[] = {
366 {"help", 0, NULL, 'h'},
367 {"foreground", 0, NULL, 'f'},
368 {"verbose", 0, NULL, 'v'},
369 {"user", 2, NULL, 'U'},
370 {"udev", 0, NULL, 'u'},
371 {"exit", 0, NULL, 'x'},
372 {"force-exit", 0, NULL, 'X'},
373 {NULL, 0, NULL, 0}
374 };
375 int c;
376
377 while (1) {
378 c = getopt_long(argc, argv, "hfvuU:xX", longopts, (int *) 0);
379 if (c == -1) {
380 break;
381 }
382
383 switch (c) {
384 case 'h':
385 usage();
386 exit(0);
387 case 'f':
388 foreground = 1;
389 break;
390 case 'v':
391 ++verbose;
392 break;
393 case 'U':
394 drop_privileges = 1;
395 drop_user = optarg;
396 break;
397 case 'u':
398 opt_udev = 1;
399 break;
400 case 'x':
401 opt_exit = 1;
402 exit_signal = SIGUSR1;
403 break;
404 case 'X':
405 opt_exit = 1;
406 exit_signal = SIGTERM;
407 break;
408 default:
409 usage();
410 exit(2);
411 }
412 }
413}
414
415int main(int argc, char *argv[])
416{
417 int listenfd;
418 int res = 0;
419 int lfd;
420 struct flock lock;
421 char pids[10];
422
423 parse_opts(argc, argv);
424
425 argc -= optind;
426 argv += optind;
427
428 if (!foreground) {
429 verbose += LL_WARNING;
430 log_enable_syslog();
431 } else {
432 verbose += LL_NOTICE;
433 }
434
435 /* set log level to specified verbosity */
436 log_level = verbose;
437
438 usbmuxd_log(LL_NOTICE, "usbmuxd v%s starting up", USBMUXD_VERSION);
439 should_exit = 0;
440 should_discover = 0;
441
442 set_signal_handlers();
443 signal(SIGPIPE, SIG_IGN);
444
445 res = lfd = open(lockfile, O_WRONLY|O_CREAT, 0644);
446 if(res == -1) {
447 usbmuxd_log(LL_FATAL, "Could not open lockfile");
448 goto terminate;
449 }
450 lock.l_type = F_WRLCK;
451 lock.l_whence = SEEK_SET;
452 lock.l_start = 0;
453 lock.l_len = 0;
454 fcntl(lfd, F_GETLK, &lock);
455 close(lfd);
456 if (lock.l_type != F_UNLCK) {
457 if (opt_exit) {
458 if (lock.l_pid && !kill(lock.l_pid, 0)) {
459 usbmuxd_log(LL_NOTICE, "Sending signal %d to instance with pid %d", exit_signal, lock.l_pid);
460 res = 0;
461 if (kill(lock.l_pid, exit_signal) < 0) {
462 usbmuxd_log(LL_FATAL, "Could not deliver signal %d to pid %d", exit_signal, lock.l_pid);
463 res = -1;
464 }
465 goto terminate;
466 } else {
467 usbmuxd_log(LL_ERROR, "Could not determine pid of the other running instance!");
468 res = -1;
469 goto terminate;
470 }
471 } else {
472 if (!opt_udev) {
473 usbmuxd_log(LL_ERROR, "Another instance is already running (pid %d). exiting.", lock.l_pid);
474 res = -1;
475 } else {
476 usbmuxd_log(LL_NOTICE, "Another instance is already running (pid %d). Telling it to check for devices.", lock.l_pid);
477 if (lock.l_pid && !kill(lock.l_pid, 0)) {
478 usbmuxd_log(LL_NOTICE, "Sending signal SIGUSR2 to instance with pid %d", lock.l_pid);
479 res = 0;
480 if (kill(lock.l_pid, SIGUSR2) < 0) {
481 usbmuxd_log(LL_FATAL, "Could not deliver SIGUSR2 to pid %d", lock.l_pid);
482 res = -1;
483 }
484 } else {
485 usbmuxd_log(LL_ERROR, "Could not determine pid of the other running instance!");
486 res = -1;
487 }
488 }
489 goto terminate;
490 }
491 }
492 unlink(lockfile);
493
494 if (opt_exit) {
495 usbmuxd_log(LL_NOTICE, "No running instance found, none killed. exiting.");
496 goto terminate;
497 }
498
499 if (!foreground) {
500 if ((res = daemonize()) < 0) {
501 fprintf(stderr, "usbmuxd: FATAL: Could not daemonize!\n");
502 usbmuxd_log(LL_FATAL, "Could not daemonize!");
503 goto terminate;
504 }
505 }
506
507 // now open the lockfile and place the lock
508 res = lfd = open(lockfile, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL, 0644);
509 if(res < 0) {
510 usbmuxd_log(LL_FATAL, "Could not open lockfile");
511 goto terminate;
512 }
513 lock.l_type = F_WRLCK;
514 lock.l_whence = SEEK_SET;
515 lock.l_start = 0;
516 lock.l_len = 0;
517 if ((res = fcntl(lfd, F_SETLK, &lock)) < 0) {
518 usbmuxd_log(LL_FATAL, "Lockfile locking failed!");
519 goto terminate;
520 }
521 sprintf(pids, "%d", getpid());
522 if ((res = write(lfd, pids, strlen(pids))) != strlen(pids)) {
523 usbmuxd_log(LL_FATAL, "Could not write pidfile!");
524 if(res >= 0)
525 res = -2;
526 goto terminate;
527 }
528
529 usbmuxd_log(LL_INFO, "Creating socket");
530 res = listenfd = create_socket();
531 if(listenfd < 0)
532 goto terminate;
533
534 // drop elevated privileges
535 if (drop_privileges && (getuid() == 0 || geteuid() == 0)) {
536 struct passwd *pw;
537 if (!drop_user) {
538 usbmuxd_log(LL_FATAL, "No user to drop privileges to?");
539 res = -1;
540 goto terminate;
541 }
542 pw = getpwnam(drop_user);
543 if (!pw) {
544 usbmuxd_log(LL_FATAL, "Dropping privileges failed, check if user '%s' exists!", drop_user);
545 res = -1;
546 goto terminate;
547 }
548 if (pw->pw_uid == 0) {
549 usbmuxd_log(LL_INFO, "Not dropping privileges to root");
550 } else {
551 if ((res = initgroups(drop_user, pw->pw_gid)) < 0) {
552 usbmuxd_log(LL_FATAL, "Failed to drop privileges (cannot set supplementary groups)");
553 goto terminate;
554 }
555 if ((res = setgid(pw->pw_gid)) < 0) {
556 usbmuxd_log(LL_FATAL, "Failed to drop privileges (cannot set group ID to %d)", pw->pw_gid);
557 goto terminate;
558 }
559 if ((res = setuid(pw->pw_uid)) < 0) {
560 usbmuxd_log(LL_FATAL, "Failed to drop privileges (cannot set user ID to %d)", pw->pw_uid);
561 goto terminate;
562 }
563
564 // security check
565 if (setuid(0) != -1) {
566 usbmuxd_log(LL_FATAL, "Failed to drop privileges properly!");
567 res = -1;
568 goto terminate;
569 }
570 if (getuid() != pw->pw_uid || getgid() != pw->pw_gid) {
571 usbmuxd_log(LL_FATAL, "Failed to drop privileges properly!");
572 res = -1;
573 goto terminate;
574 }
575 usbmuxd_log(LL_NOTICE, "Successfully dropped privileges to '%s'", drop_user);
576 }
577 }
578
579 client_init();
580 device_init();
581 usbmuxd_log(LL_INFO, "Initializing USB");
582 if((res = usb_init()) < 0)
583 goto terminate;
584
585 usbmuxd_log(LL_INFO, "%d device%s detected", res, (res==1)?"":"s");
586
587 usbmuxd_log(LL_NOTICE, "Initialization complete");
588
589 if (report_to_parent)
590 if((res = notify_parent(0)) < 0)
591 goto terminate;
592
593 if(opt_udev)
594 usb_autodiscover(0); // discovery triggered by udev
595
596 res = main_loop(listenfd);
597 if(res < 0)
598 usbmuxd_log(LL_FATAL, "main_loop failed");
599
600 usbmuxd_log(LL_NOTICE, "usbmuxd shutting down");
601 device_kill_connections();
602 usb_shutdown();
603 device_shutdown();
604 client_shutdown();
605 usbmuxd_log(LL_NOTICE, "Shutdown complete");
606
607terminate:
608 log_disable_syslog();
609
610 if (res < 0)
611 res = -res;
612 else
613 res = 0;
614 if (report_to_parent)
615 notify_parent(res);
616
617 return res;
618}