server: Introduce server_command_task.
[paraslash.git] / server.c
1 /*
2 * Copyright (C) 1997-2008 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file server.c Paraslash's main server. */
8
9
10 /**
11 * \mainpage Paraslash API Reference
12 *
13 * Starting points for getting an overview are
14 *
15 * probably:
16 *
17 * - The main programs: \ref server.c, \ref audiod.c, \ref client.c,
18 * \ref audioc.c, \ref fsck.c,
19 * - Server: \ref server_command, \ref sender,
20 * - Audio file selector: \ref audio_format_handler, \ref mood, \ref afs_table,
21 * - Client: \ref receiver, \ref receiver_node, \ref filter, \ref filter_node.
22 *
23 *
24 * The gory details, listed by topic:
25 *
26 * - Audio format handlers: \ref mp3_afh.c, \ref ogg_afh.c, \ref aac_afh.c,
27 * - Decoders: \ref mp3dec.c, \ref oggdec.c, \ref aacdec.c,
28 * - Volume normalizer: \ref compress.c,
29 * - Output: \ref alsa_write.c, \ref osx_write.c,
30 * - http: \ref http_recv.c, \ref http_send.c,
31 * - ortp: \ref ortp_recv.c, \ref ortp_send.c,
32 * - dccp: \ref dccp_recv.c, \ref dccp_send.c,
33 * - Audio file selector: \ref afs.c, \ref aft.c, \ref mood.c,
34 * - Afs structures: \ref afs_table, \ref audio_file_data,
35 * \ref afs_info \ref afh_info,
36 * - Afs tables: \ref aft.c, \ref mood.c, \ref playlist.c,
37 * \ref attribute.c, \ref score.c,
38 * - The virtual streaming system: \ref vss.c, \ref chunk_queue.c.
39 *
40 * Lower levels:
41 *
42 * - Scheduling: \ref sched.c, \ref sched.h,
43 * - Networking: \ref net.c,
44 * - File descriptors: \ref fd.c,
45 * - Signals: \ref signal.c,
46 * - Daemons: \ref daemon.c,
47 * - Strings: \ref string.c, \ref string.h,
48 * - Time: \ref time.c,
49 * - Spawning processes: \ref exec.c,
50 * - Inter process communication: \ref ipc.c,
51 * - The object storage layer: \ref osl.c,
52 * - Blob tables: \ref blob.c,
53 * - The error subssystem: \ref error.h.
54 * - Access control for paraslash senders: \ref acl.c, \ref acl.h.
55 *
56 * Low-level data structures:
57 *
58 * - Doubly linked lists: \ref list.h,
59 * - Red-black trees: \ref rbtree.h, \ref rbtree.c,
60 * - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
61 * - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c,
62 * - Crypto: \ref crypt.c.
63 *
64 */
65
66 #include <signal.h>
67 #include <sys/types.h>
68 #include <dirent.h>
69
70 #include "para.h"
71 #include "error.h"
72 #include "server.cmdline.h"
73 #include "afh.h"
74 #include "string.h"
75 #include "afs.h"
76 #include "server.h"
77 #include "vss.h"
78 #include "config.h"
79 #include "close_on_fork.h"
80 #include "list.h"
81 #include "send.h"
82 #include "net.h"
83 #include "daemon.h"
84 #include "ipc.h"
85 #include "fd.h"
86 #include "sched.h"
87 #include "signal.h"
88 #include "user_list.h"
89
90 /** define the array of error lists needed by para_server */
91 INIT_SERVER_ERRLISTS;
92
93 /** shut down non-authorized connections after that many seconds */
94 #define ALARM_TIMEOUT 10
95
96 /**
97 * Pointer to shared memory area for communication between para_server
98 * and its children. Exported to vss.c. command.c and to afs.
99 */
100 struct misc_meta_data *mmd;
101
102 /**
103 * the configuration of para_server
104 *
105 * It also contains the options for the audio file selector, audio format
106 * handler and all supported senders.
107 */
108 struct server_args_info conf;
109
110 /** the file containing user information (public key, permissions) */
111 char *user_list_file = NULL;
112
113 /* global variables for server-internal use */
114 static FILE *logfile;
115 static int mmd_mutex, mmd_shm_id;
116 static int signal_pipe;
117
118 struct server_command_task {
119 /** TCP port on which para_server listens for connections. */
120 int listen_fd;
121 /** Copied from para_server's main function. */
122 int argc;
123 /** Argument vector passed to para_server's main function. */
124 char **argv;
125 /** The command task structure for scheduling. */
126 //struct task task;
127 char dummy;
128 };
129
130 /**
131 * para_server's log function
132 *
133 * \param ll the log level
134 * \param fmt the format string describing the log message
135 */
136 void para_log(int ll, const char* fmt,...)
137 {
138 va_list argp;
139 FILE *outfd;
140 struct tm *tm;
141 time_t t1;
142 char str[MAXLINE] = "";
143 pid_t mypid;
144
145 if (ll < conf.loglevel_arg)
146 return;
147 outfd = logfile? logfile : stderr;
148 time(&t1);
149 tm = localtime(&t1);
150 strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
151 fprintf(outfd, "%s ", str);
152 if (conf.loglevel_arg <= INFO)
153 fprintf(outfd, "%i: ", ll);
154 mypid = getpid();
155 if (conf.loglevel_arg <= INFO)
156 fprintf(outfd, "(%d) ", (int)mypid);
157 va_start(argp, fmt);
158 vfprintf(outfd, fmt, argp);
159 va_end(argp);
160 }
161
162 /*
163 * setup shared memory area and get mutex for locking
164 */
165 static void shm_init(void)
166 {
167 void *shm;
168 int ret = shm_new(sizeof(struct misc_meta_data));
169
170 if (ret < 0)
171 goto err_out;
172
173 ret = shm_attach(ret, ATTACH_RW, &shm);
174 if (ret < 0)
175 goto err_out;
176 mmd = shm;
177 mmd_shm_id = ret;
178
179 ret = mutex_new();
180 if (ret < 0)
181 goto err_out;
182 mmd_mutex = ret;
183
184 mmd->num_played = 0;
185 mmd->num_commands = 0;
186 mmd->events = 0;
187 mmd->num_connects = 0;
188 mmd->active_connections = 0;
189 mmd->vss_status_flags = VSS_NEXT;
190 mmd->new_vss_status_flags = VSS_NEXT;
191 return;
192 err_out:
193 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
194 exit(EXIT_FAILURE);
195 }
196
197 /**
198 * lock the shared memory area containing the mmd struct
199 *
200 * \sa semop(2), struct misc_meta_data.
201 */
202 void mmd_lock(void)
203 {
204 mutex_lock(mmd_mutex);
205 }
206
207 /**
208 * unlock the shared memory area containing the mmd struct
209 *
210 * \sa semop(2), struct misc_meta_data
211 */
212
213 void mmd_unlock(void)
214 {
215 mutex_unlock(mmd_mutex);
216 }
217
218 static void parse_config(int override)
219 {
220 char *home = para_homedir();
221 struct stat statbuf;
222 int ret;
223 char *cf;
224
225 if (conf.config_file_given)
226 cf = para_strdup(conf.config_file_arg);
227 else
228 cf = make_message("%s/.paraslash/server.conf", home);
229 free(user_list_file);
230 if (!conf.user_list_given)
231 user_list_file = make_message("%s/.paraslash/server.users", home);
232 else
233 user_list_file = para_strdup(conf.user_list_arg);
234 ret = stat(cf, &statbuf);
235 if (ret && conf.config_file_given) {
236 ret = -1;
237 PARA_EMERG_LOG("can not stat config file %s\n", cf);
238 goto out;
239 }
240 if (!ret) {
241 int tmp = conf.daemon_given;
242 struct server_cmdline_parser_params params = {
243 .override = override,
244 .initialize = 0,
245 .check_required = 1,
246 .check_ambiguity = 0,
247 .print_errors = 1
248 };
249 server_cmdline_parser_config_file(cf, &conf, &params);
250 conf.daemon_given = tmp;
251 }
252 if (conf.logfile_given)
253 logfile = open_log(conf.logfile_arg);
254 ret = 1;
255 out:
256 free(cf);
257 free(home);
258 if (ret > 0)
259 return;
260 free(user_list_file);
261 user_list_file = NULL;
262 exit(EXIT_FAILURE);
263 }
264
265 static void setup_signal_handling(void)
266 {
267 signal_pipe = para_signal_init(); /* always successful */
268
269 PARA_NOTICE_LOG("setting up signal handlers\n");
270 if (para_install_sighandler(SIGINT) < 0)
271 goto err;
272 if (para_install_sighandler(SIGTERM) < 0)
273 goto err;
274 if (para_install_sighandler(SIGHUP) < 0)
275 goto err;
276 if (para_install_sighandler(SIGCHLD) < 0)
277 goto err;
278 if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
279 goto err;
280 if (signal(SIGUSR1, SIG_IGN) == SIG_ERR)
281 goto err;
282 add_close_on_fork_list(signal_pipe);
283 return;
284 err:
285 PARA_EMERG_LOG("could not install signal handlers\n");
286 exit(EXIT_FAILURE);
287 }
288
289 static void init_command_task(struct server_command_task *sct)
290 {
291 int ret;
292
293 PARA_NOTICE_LOG("initializing tcp command socket\n");
294 ret = para_listen(AF_UNSPEC, IPPROTO_TCP, conf.port_arg);
295 if (ret < 0)
296 goto err;
297 sct->listen_fd = ret;
298 ret = mark_fd_nonblocking(sct->listen_fd);
299 if (ret < 0)
300 goto err;
301 add_close_on_fork_list(sct->listen_fd); /* child doesn't need the listener */
302 return;
303 err:
304 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
305 exit(EXIT_FAILURE);
306 }
307
308 static void init_random_seed(void)
309 {
310 unsigned int seed;
311 int fd, ret = para_open("/dev/urandom", O_RDONLY, 0);
312
313 if (ret < 0)
314 goto err;
315 fd = ret;
316 ret = read(fd, &seed, sizeof(seed));
317 if (ret < 0) {
318 ret = -ERRNO_TO_PARA_ERROR(errno);
319 goto out;
320 }
321 if (ret != sizeof(seed)) {
322 ret = -ERRNO_TO_PARA_ERROR(EIO);
323 goto out;
324 }
325 srandom(seed);
326 ret = 1;
327 out:
328 close(fd);
329 if (ret >= 0)
330 return;
331 err:
332 PARA_EMERG_LOG("can not seed pseudo random number generator: %s\n",
333 para_strerror(-ret));
334 exit(EXIT_FAILURE);
335 }
336
337 uint32_t afs_socket_cookie;
338 int afs_socket;
339 static pid_t afs_pid;
340
341 static void init_afs(void)
342 {
343 int ret, afs_server_socket[2];
344
345 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
346 if (ret < 0)
347 exit(EXIT_FAILURE);
348 afs_socket_cookie = para_random((uint32_t)-1);
349 afs_pid = fork();
350 if (afs_pid < 0)
351 exit(EXIT_FAILURE);
352 if (!afs_pid) { /* child (afs) */
353 close(afs_server_socket[0]);
354 afs_init(afs_socket_cookie, afs_server_socket[1]);
355 }
356 close(afs_server_socket[1]);
357 afs_socket = afs_server_socket[0];
358 ret = mark_fd_nonblocking(afs_socket);
359 if (ret < 0)
360 exit(EXIT_FAILURE);
361 add_close_on_fork_list(afs_socket);
362 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
363 (unsigned) afs_socket_cookie);
364 }
365
366 static void server_init(int argc, char **argv)
367 {
368 /* connector's address information */
369 struct server_cmdline_parser_params params = {
370 .override = 0,
371 .initialize = 1,
372 .check_required = 0,
373 .check_ambiguity = 0,
374 .print_errors = 1
375 };
376 init_random_seed();
377 /* parse command line options */
378 server_cmdline_parser_ext(argc, argv, &conf, &params);
379 HANDLE_VERSION_FLAG("server", conf);
380 para_drop_privileges(conf.user_arg, conf.group_arg);
381 /* parse config file, open log and set defaults */
382 parse_config(0);
383 log_welcome("para_server", conf.loglevel_arg);
384 shm_init(); /* init mmd struct */
385 server_uptime(UPTIME_SET); /* reset server uptime */
386 init_user_list(user_list_file);
387 /* become daemon */
388 if (conf.daemon_given)
389 daemon_init();
390 PARA_NOTICE_LOG("initializing audio format handlers\n");
391 afh_init();
392 mmd->server_pid = getpid();
393 setup_signal_handling();
394 PARA_NOTICE_LOG("initializing the audio file selector\n");
395 init_afs();
396 PARA_NOTICE_LOG("initializing virtual streaming system\n");
397 vss_init();
398 mmd_lock();
399 PARA_NOTICE_LOG("server init complete\n");
400 }
401
402 /*
403 * called when server gets SIGHUP or when client invokes hup command.
404 */
405 static void handle_sighup(void)
406 {
407 PARA_NOTICE_LOG("SIGHUP\n");
408 close_log(logfile); /* gets reopened if necessary by parse_config */
409 logfile = NULL;
410 parse_config(1); /* reopens log */
411 init_user_list(user_list_file); /* reload user list */
412 if (afs_pid)
413 kill(afs_pid, SIGHUP);
414 }
415
416 static void status_refresh(void)
417 {
418 static int prev_uptime = -1, prev_events = -1;
419 int uptime = server_uptime(UPTIME_GET), ret = 1;
420
421 if (prev_events != mmd->events)
422 goto out;
423 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
424 goto out;
425 if (uptime / 60 != prev_uptime / 60)
426 goto out;
427 ret = 0;
428 out:
429 prev_uptime = uptime;
430 prev_events = mmd->events;
431 mmd->vss_status_flags = mmd->new_vss_status_flags;
432 if (ret) {
433 PARA_DEBUG_LOG("%d events, forcing status update\n",
434 mmd->events);
435 killpg(0, SIGUSR1);
436 }
437 }
438
439 static int server_select(int max_fileno, fd_set *readfds, fd_set *writefds,
440 struct timeval *timeout_tv)
441 {
442 int ret;
443
444 status_refresh();
445 mmd_unlock();
446 ret = para_select(max_fileno + 1, readfds, writefds, timeout_tv);
447 mmd_lock();
448 return ret;
449 }
450
451 static void command_pre_select(int *max_fileno, fd_set *rfds, char *dummy_ptr)
452 {
453 struct server_command_task *sct = container_of(dummy_ptr, struct server_command_task, dummy);
454 para_fd_set(sct->listen_fd, rfds, max_fileno);
455 }
456
457 static void command_post_select(fd_set *rfds, char *dummy_ptr)
458 {
459 struct server_command_task *sct = container_of(dummy_ptr, struct server_command_task, dummy);
460
461 int new_fd, ret;
462 char *peer_name;
463 pid_t child_pid;
464
465 if (!FD_ISSET(sct->listen_fd, rfds))
466 return;
467 ret = para_accept(sct->listen_fd, NULL, 0);
468 if (ret < 0)
469 goto out;
470 new_fd = ret;
471 peer_name = remote_name(new_fd);
472 PARA_INFO_LOG("got connection from %s, forking\n", peer_name);
473 mmd->num_connects++;
474 mmd->active_connections++;
475 random();
476 child_pid = fork();
477 if (child_pid < 0) {
478 ret = -ERRNO_TO_PARA_ERROR(errno);
479 goto out;
480 }
481 if (child_pid) {
482 close(new_fd);
483 /* parent keeps accepting connections */
484 return;
485 }
486 alarm(ALARM_TIMEOUT);
487 close_listed_fds();
488 para_signal_shutdown();
489 /*
490 * put info on who we are serving into argv[0] to make
491 * client ip visible in top/ps
492 */
493 // for (i = argc - 1; i >= 0; i--)
494 // memset(argv[i], 0, strlen(argv[i]));
495 // sprintf(argv[0], "para_server (serving %s)", peer_name);
496 return handle_connect(new_fd, peer_name);
497 out:
498 if (ret < 0)
499 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
500 }
501
502 /**
503 * the main function of para_server
504 *
505 * \param argc usual argument count
506 * \param argv usual argument vector
507 *
508 * \return EXIT_SUCCESS or EXIT_FAILURE
509 *
510 */
511 int main(int argc, char *argv[])
512 {
513 int max_fileno, ret;
514 fd_set rfds, wfds;
515 struct timeval *timeout;
516 struct server_command_task server_command_task_struct;
517
518
519 valid_fd_012();
520 server_init(argc, argv);
521 init_command_task(&server_command_task_struct);
522 repeat:
523 FD_ZERO(&rfds);
524 FD_ZERO(&wfds);
525 max_fileno = -1;
526 command_pre_select(&max_fileno, &rfds, &server_command_task_struct.dummy);
527 para_fd_set(signal_pipe, &rfds, &max_fileno);
528 timeout = vss_preselect(&rfds, &wfds, &max_fileno);
529 server_select(max_fileno + 1, &rfds, &wfds, timeout);
530 vss_post_select(&rfds, &wfds);
531 if (FD_ISSET(signal_pipe, &rfds)) {
532 int sig;
533 pid_t pid;
534 sig = para_next_signal();
535 switch (sig) {
536 case SIGHUP:
537 handle_sighup();
538 break;
539 case SIGCHLD:
540 for (;;) {
541 ret = para_reap_child(&pid);
542 if (ret <= 0)
543 break;
544 if (pid != afs_pid)
545 continue;
546 PARA_EMERG_LOG("fatal: afs died\n");
547 goto genocide;
548 }
549 break;
550 /* die on sigint/sigterm. Kill all children too. */
551 case SIGINT:
552 case SIGTERM:
553 PARA_EMERG_LOG("terminating on signal %d\n", sig);
554 genocide:
555 kill(0, SIGTERM);
556 mutex_destroy(mmd_mutex);
557 shm_detach(mmd);
558 shm_destroy(mmd_shm_id);
559
560 exit(EXIT_FAILURE);
561 }
562 }
563 command_post_select(&rfds, &server_command_task_struct.dummy);
564 goto repeat;
565 }