Merge remote branch 'refs/remotes/fml/master'
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2010 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file afs.c Paraslash's audio file selector. */
8
9 #include <regex.h>
10 #include <signal.h>
11 #include <fnmatch.h>
12 #include <openssl/rc4.h>
13 #include <osl.h>
14
15 #include "server.cmdline.h"
16 #include "para.h"
17 #include "error.h"
18 #include "crypt.h"
19 #include "string.h"
20 #include "afh.h"
21 #include "afs.h"
22 #include "server.h"
23 #include <dirent.h> /* readdir() */
24 #include <sys/mman.h>
25 #include <sys/time.h>
26 #include "net.h"
27 #include "ipc.h"
28 #include "list.h"
29 #include "sched.h"
30 #include "signal.h"
31 #include "fd.h"
32 #include "mood.h"
33
34 /** The osl tables used by afs. \sa blob.c. */
35 enum afs_table_num {
36 /** Contains audio file information. See aft.c. */
37 TBLNUM_AUDIO_FILES,
38 /** The table for the paraslash attributes. See attribute.c. */
39 TBLNUM_ATTRIBUTES,
40 /**
41 * Paraslash's scoring system is based on Gaussian normal
42 * distributions, and the relevant data is stored in the rbtrees of an
43 * osl table containing only volatile columns. See score.c for
44 * details.
45 */
46 TBLNUM_SCORES,
47 /**
48 * A standard blob table containing the mood definitions. For details
49 * see mood.c.
50 */
51 TBLNUM_MOODS,
52 /** A blob table containing lyrics on a per-song basis. */
53 TBLNUM_LYRICS,
54 /** Another blob table for images (for example album cover art). */
55 TBLNUM_IMAGES,
56 /** Yet another blob table for storing standard playlists. */
57 TBLNUM_PLAYLIST,
58 /** How many tables are in use? */
59 NUM_AFS_TABLES
60 };
61
62 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
63 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
64 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
65 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
66 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
67 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
68 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
69 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
70 };
71
72 struct command_task {
73 /** The file descriptor for the local socket. */
74 int fd;
75 /**
76 * Value sent by the command handlers to identify themselves as
77 * children of the running para_server.
78 */
79 uint32_t cookie;
80 /** The associated task structure. */
81 struct task task;
82 };
83
84 extern int mmd_mutex;
85 extern struct misc_meta_data *mmd;
86
87 static int server_socket;
88 static struct command_task command_task_struct;
89 static struct signal_task signal_task_struct;
90
91 static enum play_mode current_play_mode;
92 static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
93
94 /**
95 * A random number used to "authenticate" the connection.
96 *
97 * para_server picks this number by random before forking the afs process. The
98 * command handlers write this number together with the id of the shared memory
99 * area containing the query. This way, a malicious local user has to know this
100 * number to be able to cause the afs process to crash by sending fake queries.
101 */
102 extern uint32_t afs_socket_cookie;
103
104 /**
105 * Struct to let command handlers execute a callback in afs context.
106 *
107 * Commands that need to change the state of afs can't change the relevant data
108 * structures directly because commands are executed in a child process, i.e.
109 * they get their own virtual address space.
110 *
111 * This structure is used by \p send_callback_request() (executed from handler
112 * context) in order to let the afs process call the specified function. An
113 * instance of that structure is written to a shared memory area together with
114 * the arguments to the callback function. The identifier of the shared memory
115 * area is written to the command socket.
116 *
117 * The afs process accepts connections on the command socket and reads the
118 * shared memory id, attaches the corresponing area, calls the given handler to
119 * perform the desired action and to optionally compute a result.
120 *
121 * The result and a \p callback_result structure is then written to another
122 * shared memory area. The identifier for that area is written to the handler's
123 * command socket, so that the handler process can read the id, attach the
124 * shared memory area and use the result.
125 *
126 * \sa struct callback_result.
127 */
128 struct callback_query {
129 /** The function to be called. */
130 callback_function *handler;
131 /** The number of bytes of the query */
132 size_t query_size;
133 };
134
135 /**
136 * Structure embedded in the result of a callback.
137 *
138 * If the callback produced a result, an instance of that structure is embeeded
139 * into the shared memory area holding the result, mainly to let the command
140 * handler know the size of the result.
141 *
142 * \sa struct callback_query.
143 */
144 struct callback_result {
145 /** The number of bytes of the result. */
146 size_t result_size;
147 };
148
149 static int dispatch_result(int result_shmid, callback_result_handler *handler,
150 void *private_result_data)
151 {
152 struct osl_object result;
153 void *result_shm;
154 int ret2, ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
155 struct callback_result *cr = result_shm;
156
157 if (ret < 0) {
158 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
159 return ret;
160 }
161 result.size = cr->result_size;
162 result.data = result_shm + sizeof(*cr);
163 if (result.size) {
164 assert(handler);
165 ret = handler(&result, private_result_data);
166 if (ret < 0)
167 PARA_NOTICE_LOG("result handler error: %s\n",
168 para_strerror(-ret));
169 }
170 ret2 = shm_detach(result_shm);
171 if (ret2 < 0) {
172 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
173 if (ret >= 0)
174 ret = ret2;
175 }
176 return ret;
177 }
178
179 /**
180 * Ask the afs process to call a given function.
181 *
182 * \param f The function to be called.
183 * \param query Pointer to arbitrary data for the callback.
184 * \param result_handler Called for each shm area sent by the callback.
185 * \param private_result_data Passed verbatim to \a result_handler.
186 *
187 * This function creates a socket for communication with the afs process and a
188 * shared memory area (sma) to which the buffer pointed to by \a query is
189 * copied. It then notifies the afs process that the callback function \a f
190 * should be executed by sending the shared memory identifier (shmid) to the
191 * socket.
192
193 * If the callback produces a result, it sends any number of shared memory
194 * identifiers back via the socket. For each such identifier received, \a
195 * result_handler is called. The contents of the sma identified by the received
196 * shmid are passed to that function as an osl object. The private_result_data
197 * pointer is passed as the second argument to \a result_handler.
198 *
199 * \return Standard.
200 *
201 * \sa send_option_arg_callback_request(), send_standard_callback_request().
202 */
203 int send_callback_request(callback_function *f, struct osl_object *query,
204 callback_result_handler *result_handler,
205 void *private_result_data)
206 {
207 struct callback_query *cq;
208 int ret, fd = -1, query_shmid, result_shmid;
209 void *query_shm;
210 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
211 size_t query_shm_size = sizeof(*cq);
212 int dispatch_error = 0;
213
214 if (query)
215 query_shm_size += query->size;
216 ret = shm_new(query_shm_size);
217 if (ret < 0)
218 return ret;
219 query_shmid = ret;
220 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
221 if (ret < 0)
222 goto out;
223 cq = query_shm;
224 cq->handler = f;
225 cq->query_size = query_shm_size - sizeof(*cq);
226
227 if (query)
228 memcpy(query_shm + sizeof(*cq), query->data, query->size);
229 ret = shm_detach(query_shm);
230 if (ret < 0)
231 goto out;
232
233 *(uint32_t *) buf = afs_socket_cookie;
234 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
235
236 ret = connect_local_socket(conf.afs_socket_arg);
237 if (ret < 0)
238 goto out;
239 fd = ret;
240 ret = send_bin_buffer(fd, buf, sizeof(buf));
241 if (ret < 0)
242 goto out;
243 /*
244 * Read all shmids from afs.
245 *
246 * Even if the dispatcher returns an error we _must_ continue to read
247 * shmids from fd so that we can destroy all shared memory areas that
248 * have been created for us by the afs process.
249 */
250 for (;;) {
251 ret = recv_bin_buffer(fd, buf, sizeof(int));
252 if (ret <= 0)
253 goto out;
254 assert(ret == sizeof(int));
255 ret = *(int *) buf;
256 assert(ret > 0);
257 result_shmid = ret;
258 if (!dispatch_error) {
259 ret = dispatch_result(result_shmid, result_handler,
260 private_result_data);
261 if (ret < 0)
262 dispatch_error = 1;
263 }
264 ret = shm_destroy(result_shmid);
265 if (ret < 0)
266 PARA_CRIT_LOG("destroy result failed: %s\n",
267 para_strerror(-ret));
268 }
269 out:
270 if (shm_destroy(query_shmid) < 0)
271 PARA_CRIT_LOG("shm destroy error\n");
272 if (fd >= 0)
273 close(fd);
274 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
275 return ret;
276 }
277
278 /**
279 * Send a callback request passing an options structure and an argument vector.
280 *
281 * \param options pointer to an arbitrary data structure.
282 * \param argc Argument count.
283 * \param argv Standard argument vector.
284 * \param f The callback function.
285 * \param result_handler See \ref send_callback_request.
286 * \param private_result_data See \ref send_callback_request.
287 *
288 * Some commands have a couple of options that are parsed in child context for
289 * syntactic correctness and are stored in a special options structure for that
290 * command. This function allows to pass such a structure together with a list
291 * of further arguments (often a list of audio files) to the parent process.
292 *
293 * \sa send_standard_callback_request(), send_callback_request().
294 */
295 int send_option_arg_callback_request(struct osl_object *options,
296 int argc, char * const * const argv, callback_function *f,
297 callback_result_handler *result_handler,
298 void *private_result_data)
299 {
300 char *p;
301 int i, ret;
302 struct osl_object query = {.size = options? options->size : 0};
303
304 for (i = 0; i < argc; i++)
305 query.size += strlen(argv[i]) + 1;
306 query.data = para_malloc(query.size);
307 p = query.data;
308 if (options) {
309 memcpy(query.data, options->data, options->size);
310 p += options->size;
311 }
312 for (i = 0; i < argc; i++) {
313 strcpy(p, argv[i]); /* OK */
314 p += strlen(argv[i]) + 1;
315 }
316 ret = send_callback_request(f, &query, result_handler,
317 private_result_data);
318 free(query.data);
319 return ret;
320 }
321
322 /**
323 * Send a callback request with an argument vector only.
324 *
325 * \param argc The same meaning as in send_option_arg_callback_request().
326 * \param argv The same meaning as in send_option_arg_callback_request().
327 * \param f The same meaning as in send_option_arg_callback_request().
328 * \param result_handler See \ref send_callback_request.
329 * \param private_result_data See \ref send_callback_request.
330 *
331 * This is similar to send_option_arg_callback_request(), but no options buffer
332 * is passed to the parent process.
333 *
334 * \return The return value of the underlying call to
335 * send_option_arg_callback_request().
336 */
337 int send_standard_callback_request(int argc, char * const * const argv,
338 callback_function *f, callback_result_handler *result_handler,
339 void *private_result_data)
340 {
341 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
342 private_result_data);
343 }
344
345 static int action_if_pattern_matches(struct osl_row *row, void *data)
346 {
347 struct pattern_match_data *pmd = data;
348 struct osl_object name_obj;
349 const char *p, *name;
350 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
351 const char *pattern_txt = (const char *)pmd->patterns.data;
352
353 if (ret < 0)
354 return ret;
355 name = (char *)name_obj.data;
356 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
357 return 1;
358 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
359 return pmd->action(pmd->table, row, name, pmd->data);
360 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
361 p += strlen(p) + 1) {
362 ret = fnmatch(p, name, pmd->fnmatch_flags);
363 if (ret == FNM_NOMATCH)
364 continue;
365 if (ret)
366 return -E_FNMATCH;
367 return pmd->action(pmd->table, row, name, pmd->data);
368 }
369 return 1;
370 }
371
372 /**
373 * Execute the given function for each matching row.
374 *
375 * \param pmd Describes what to match and how.
376 *
377 * \return Standard.
378 */
379 int for_each_matching_row(struct pattern_match_data *pmd)
380 {
381 if (pmd->pm_flags & PM_REVERSE_LOOP)
382 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
383 action_if_pattern_matches));
384 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
385 action_if_pattern_matches));
386 }
387
388 /**
389 * Compare two osl objects of string type.
390 *
391 * \param obj1 Pointer to the first object.
392 * \param obj2 Pointer to the second object.
393 *
394 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
395 * are taken into account.
396 *
397 * \return It returns an integer less than, equal to, or greater than zero if
398 * \a obj1 is found, respectively, to be less than, to match, or be greater than
399 * obj2.
400 *
401 * \sa strcmp(3), strncmp(3), osl_compare_func.
402 */
403 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
404 {
405 const char *str1 = (const char *)obj1->data;
406 const char *str2 = (const char *)obj2->data;
407 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
408 }
409
410 static int pass_afd(int fd, char *buf, size_t size)
411 {
412 struct msghdr msg = {.msg_iov = NULL};
413 struct cmsghdr *cmsg;
414 char control[255];
415 int ret;
416 struct iovec iov;
417
418 iov.iov_base = buf;
419 iov.iov_len = size;
420
421 msg.msg_iov = &iov;
422 msg.msg_iovlen = 1;
423
424 msg.msg_control = control;
425 msg.msg_controllen = sizeof(control);
426
427 cmsg = CMSG_FIRSTHDR(&msg);
428 cmsg->cmsg_level = SOL_SOCKET;
429 cmsg->cmsg_type = SCM_RIGHTS;
430 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
431 *(int *)CMSG_DATA(cmsg) = fd;
432
433 /* Sum of the length of all control messages in the buffer */
434 msg.msg_controllen = cmsg->cmsg_len;
435 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
436 ret = sendmsg(server_socket, &msg, 0);
437 if (ret < 0) {
438 ret = -ERRNO_TO_PARA_ERROR(errno);
439 return ret;
440 }
441 return 1;
442 }
443
444 /**
445 * Open the audio file with highest score.
446 *
447 * This stores all information for streaming the "best" audio file in a shared
448 * memory area. The id of that area and an open file descriptor for the next
449 * audio file are passed to the server process.
450 *
451 * \return Standard.
452 *
453 * \sa open_and_update_audio_file().
454 */
455 static int open_next_audio_file(void)
456 {
457 struct osl_row *aft_row;
458 struct audio_file_data afd;
459 int ret, shmid;
460 char buf[8];
461 long score;
462 again:
463 PARA_NOTICE_LOG("getting next audio file\n");
464 ret = score_get_best(&aft_row, &score);
465 if (ret < 0) {
466 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
467 goto no_admissible_files;
468 }
469 ret = open_and_update_audio_file(aft_row, score, &afd);
470 if (ret < 0) {
471 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
472 ret = score_delete(aft_row);
473 if (ret < 0) {
474 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
475 goto no_admissible_files;
476 }
477 goto again;
478 }
479 shmid = ret;
480 if (!write_ok(server_socket)) {
481 ret = -E_AFS_SOCKET;
482 goto destroy;
483 }
484 *(uint32_t *)buf = NEXT_AUDIO_FILE;
485 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
486 ret = pass_afd(afd.fd, buf, 8);
487 close(afd.fd);
488 if (ret >= 0)
489 return ret;
490 destroy:
491 shm_destroy(shmid);
492 return ret;
493 no_admissible_files:
494 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
495 *(uint32_t *)(buf + 4) = (uint32_t)0;
496 return send_bin_buffer(server_socket, buf, 8);
497 }
498
499 /* Never fails if arg == NULL */
500 static int activate_mood_or_playlist(char *arg, int *num_admissible)
501 {
502 enum play_mode mode;
503 int ret;
504
505 if (!arg) {
506 ret = change_current_mood(NULL); /* always successful */
507 mode = PLAY_MODE_MOOD;
508 } else {
509 if (!strncmp(arg, "p/", 2)) {
510 ret = playlist_open(arg + 2);
511 mode = PLAY_MODE_PLAYLIST;
512 } else if (!strncmp(arg, "m/", 2)) {
513 ret = change_current_mood(arg + 2);
514 mode = PLAY_MODE_MOOD;
515 } else
516 return -E_AFS_SYNTAX;
517 if (ret < 0)
518 return ret;
519 }
520 if (num_admissible)
521 *num_admissible = ret;
522 current_play_mode = mode;
523 if (arg != current_mop) {
524 free(current_mop);
525 if (arg) {
526 current_mop = para_strdup(arg);
527 mutex_lock(mmd_mutex);
528 strncpy(mmd->afs_mode_string, arg,
529 sizeof(mmd->afs_mode_string));
530 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
531 mutex_unlock(mmd_mutex);
532 } else {
533 mutex_lock(mmd_mutex);
534 strcpy(mmd->afs_mode_string, "dummy");
535 mutex_unlock(mmd_mutex);
536 current_mop = NULL;
537 }
538 }
539 return 1;
540 }
541
542 static void com_select_callback(int fd, const struct osl_object *query)
543 {
544 struct para_buffer pb = {
545 .max_size = SHMMAX,
546 .private_data = &fd,
547 .max_size_handler = pass_buffer_as_shm
548 };
549 char *arg = query->data;
550 int num_admissible, ret, ret2;
551
552 ret = clear_score_table();
553 if (ret < 0) {
554 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
555 goto out;
556 }
557 if (current_play_mode == PLAY_MODE_MOOD)
558 close_current_mood();
559 else
560 playlist_close();
561 ret = activate_mood_or_playlist(arg, &num_admissible);
562 if (ret < 0) {
563 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
564 para_strerror(-ret), current_mop?
565 current_mop : "dummy");
566 ret = activate_mood_or_playlist(current_mop, &num_admissible);
567 if (ret < 0) {
568 if (ret2 >= 0)
569 ret2 = para_printf(&pb, "failed, switching to dummy\n");
570 activate_mood_or_playlist(NULL, &num_admissible);
571 }
572 } else
573 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
574 current_mop : "dummy mood", num_admissible);
575 out:
576 if (ret2 >= 0 && pb.offset)
577 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
578 free(pb.buf);
579 }
580
581 /**
582 * Result handler for sending data to the para_client process.
583 *
584 * \param result The data to be sent.
585 * \param private Pointer to rc4 context.
586 *
587 * \return The return value of the underlying call to rc4_send_bin_buffer().
588 *
589 * \sa \ref callback_result_handler, \ref rc4_send_bin_buffer().
590 */
591 int rc4_send_result(struct osl_object *result, void *private)
592 {
593 struct rc4_context *rc4c = private;
594
595 if (!result->size)
596 return 1;
597 return rc4_send_bin_buffer(rc4c, result->data, result->size);
598 }
599
600 int com_select(struct rc4_context *rc4c, int argc, char * const * const argv)
601 {
602 struct osl_object query;
603
604 if (argc != 2)
605 return -E_AFS_SYNTAX;
606 query.data = argv[1];
607 query.size = strlen(argv[1]) + 1;
608 return send_callback_request(com_select_callback, &query,
609 &rc4_send_result, rc4c);
610 }
611
612 static void init_admissible_files(char *arg)
613 {
614 if (activate_mood_or_playlist(arg, NULL) < 0)
615 activate_mood_or_playlist(NULL, NULL); /* always successful */
616 }
617
618 static int setup_command_socket_or_die(void)
619 {
620 int ret, socket_fd;
621 char *socket_name = conf.afs_socket_arg;
622 struct sockaddr_un unix_addr;
623
624 unlink(socket_name);
625 ret = create_local_socket(socket_name, &unix_addr,
626 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
627 if (ret < 0) {
628 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
629 exit(EXIT_FAILURE);
630 }
631 socket_fd = ret;
632 if (listen(socket_fd , 5) < 0) {
633 PARA_EMERG_LOG("can not listen on socket\n");
634 exit(EXIT_FAILURE);
635 }
636 ret = mark_fd_nonblocking(socket_fd);
637 if (ret < 0) {
638 close(socket_fd);
639 return ret;
640 }
641 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
642 socket_fd);
643 return socket_fd;
644 }
645
646 static void close_afs_tables(void)
647 {
648 int i;
649 PARA_NOTICE_LOG("closing afs_tables\n");
650 for (i = 0; i < NUM_AFS_TABLES; i++)
651 afs_tables[i].close();
652 }
653
654 static char *database_dir;
655
656 static void get_database_dir(void)
657 {
658 if (!database_dir) {
659 if (conf.afs_database_dir_given)
660 database_dir = para_strdup(conf.afs_database_dir_arg);
661 else {
662 char *home = para_homedir();
663 database_dir = make_message(
664 "%s/.paraslash/afs_database-0.4", home);
665 free(home);
666 }
667 }
668 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
669 }
670
671 static int make_database_dir(void)
672 {
673 int ret;
674
675 get_database_dir();
676 ret = para_mkdir(database_dir, 0777);
677 if (ret >= 0 || is_errno(-ret, EEXIST))
678 return 1;
679 return ret;
680 }
681
682 static int open_afs_tables(void)
683 {
684 int i, ret;
685
686 get_database_dir();
687 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
688 database_dir);
689 for (i = 0; i < NUM_AFS_TABLES; i++) {
690 ret = afs_tables[i].open(database_dir);
691 if (ret >= 0)
692 continue;
693 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
694 para_strerror(-ret));
695 break;
696 }
697 if (ret >= 0)
698 return ret;
699 while (i)
700 afs_tables[--i].close();
701 return ret;
702 }
703
704 static void signal_pre_select(struct sched *s, struct task *t)
705 {
706 struct signal_task *st = container_of(t, struct signal_task, task);
707 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
708 }
709
710 static void afs_signal_post_select(struct sched *s, struct task *t)
711 {
712 int signum;
713
714 if (getppid() == 1) {
715 PARA_EMERG_LOG("para_server died\n");
716 goto shutdown;
717 }
718 signum = para_next_signal(&s->rfds);
719 if (signum == 0)
720 return;
721 if (signum == SIGHUP) {
722 close_afs_tables();
723 parse_config_or_die(1);
724 t->error = open_afs_tables();
725 if (t->error < 0)
726 return;
727 init_admissible_files(current_mop);
728 return;
729 }
730 PARA_EMERG_LOG("terminating on signal %d\n", signum);
731 shutdown:
732 sched_shutdown();
733 t->error = -E_AFS_SIGNAL;
734 }
735
736 static void register_signal_task(void)
737 {
738 struct signal_task *st = &signal_task_struct;
739
740 para_sigaction(SIGPIPE, SIG_IGN);
741 st->fd = para_signal_init();
742 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
743 para_install_sighandler(SIGINT);
744 para_install_sighandler(SIGTERM);
745 para_install_sighandler(SIGHUP);
746
747 st->task.pre_select = signal_pre_select;
748 st->task.post_select = afs_signal_post_select;
749 sprintf(st->task.status, "signal task");
750 register_task(&st->task);
751 }
752
753 static struct list_head afs_client_list;
754
755 /** Describes on connected afs client. */
756 struct afs_client {
757 /** Position in the afs client list. */
758 struct list_head node;
759 /** The socket file descriptor for this client. */
760 int fd;
761 /** The time the client connected. */
762 struct timeval connect_time;
763 };
764
765 static void command_pre_select(struct sched *s, struct task *t)
766 {
767 struct command_task *ct = container_of(t, struct command_task, task);
768 struct afs_client *client;
769
770 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
771 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
772 list_for_each_entry(client, &afs_client_list, node)
773 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
774 }
775
776 /**
777 * Send data as shared memory to a file descriptor.
778 *
779 * \param buf The buffer holding the data to be sent.
780 * \param size The size of \a buf.
781 * \param fd_ptr A pointer to the file descriptor.
782 *
783 * This function is used as the \a max_size handler in a \ref para_buffer
784 * structure. If used this way, it is called by \ref para_printf() whenever
785 * the buffer passed to para_printf() is about to exceed its maximal size.
786 *
787 * This function creates a shared memory area large enough to hold
788 * the content given by \a buf and \a size and sends the identifier
789 * of this area to the file descriptor given by \a fd_ptr.
790 *
791 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
792 * and positive on success.
793 */
794 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
795 {
796 int ret, shmid, fd = *(int *)fd_ptr;
797 void *shm;
798 struct callback_result *cr;
799
800 if (!buf || !size)
801 return 0;
802 ret = shm_new(size + sizeof(struct callback_result));
803 if (ret < 0)
804 return ret;
805 shmid = ret;
806 ret = shm_attach(shmid, ATTACH_RW, &shm);
807 if (ret < 0)
808 goto err;
809 cr = shm;
810 cr->result_size = size;
811 memcpy(shm + sizeof(*cr), buf, size);
812 ret = shm_detach(shm);
813 if (ret < 0)
814 goto err;
815 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
816 if (ret >= 0)
817 return ret;
818 err:
819 if (shm_destroy(shmid) < 0)
820 PARA_ERROR_LOG("destroy result failed\n");
821 return ret;
822 }
823
824 /*
825 * On errors, negative value is written to fd.
826 * On success: If query produced a result, the result_shmid is written to fd.
827 * Otherwise, zero is written.
828 */
829 static int call_callback(int fd, int query_shmid)
830 {
831 void *query_shm;
832 struct callback_query *cq;
833 struct osl_object query;
834 int ret;
835
836 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
837 if (ret < 0)
838 return ret;
839 cq = query_shm;
840 query.data = (char *)query_shm + sizeof(*cq);
841 query.size = cq->query_size;
842 cq->handler(fd, &query);
843 return shm_detach(query_shm);
844 }
845
846 static int execute_server_command(fd_set *rfds)
847 {
848 char buf[8];
849 size_t n;
850 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
851
852 if (ret < 0 || n == 0)
853 return ret;
854 buf[n] = '\0';
855 if (strcmp(buf, "new"))
856 return -E_BAD_CMD;
857 return open_next_audio_file();
858 }
859
860 /* returns 0 if no data available, 1 else */
861 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
862 {
863 uint32_t cookie;
864 int query_shmid;
865 char buf[sizeof(cookie) + sizeof(query_shmid)];
866 size_t n;
867 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
868
869 if (ret < 0)
870 goto err;
871 if (n == 0)
872 return 0;
873 if (n != sizeof(buf)) {
874 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
875 ret, (long unsigned) sizeof(buf));
876 return 1;
877 }
878 cookie = *(uint32_t *)buf;
879 if (cookie != expected_cookie) {
880 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
881 (unsigned)cookie, (unsigned)expected_cookie);
882 return 1;
883 }
884 query_shmid = *(int *)(buf + sizeof(cookie));
885 if (query_shmid < 0) {
886 PARA_WARNING_LOG("received invalid query shmid %d)\n",
887 query_shmid);
888 return 1;
889 }
890 ret = call_callback(fd, query_shmid);
891 if (ret >= 0)
892 return 1;
893 err:
894 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
895 return 1;
896 }
897
898 /** Shutdown connection if query has not arrived until this many seconds. */
899 #define AFS_CLIENT_TIMEOUT 3
900
901 static void command_post_select(struct sched *s, struct task *t)
902 {
903 struct command_task *ct = container_of(t, struct command_task, task);
904 struct sockaddr_un unix_addr;
905 struct afs_client *client, *tmp;
906 int fd, ret;
907
908 ret = execute_server_command(&s->rfds);
909 if (ret < 0) {
910 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
911 sched_shutdown();
912 return;
913 }
914 /* Check the list of connected clients. */
915 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
916 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
917 if (ret == 0) { /* prevent bogus connection flooding */
918 struct timeval diff;
919 tv_diff(now, &client->connect_time, &diff);
920 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
921 continue;
922 PARA_WARNING_LOG("connection timeout\n");
923 }
924 close(client->fd);
925 list_del(&client->node);
926 free(client);
927 }
928 /* Accept connections on the local socket. */
929 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
930 if (ret < 0)
931 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
932 if (ret <= 0)
933 return;
934 ret = mark_fd_nonblocking(fd);
935 if (ret < 0) {
936 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
937 close(fd);
938 return;
939 }
940 client = para_malloc(sizeof(*client));
941 client->fd = fd;
942 client->connect_time = *now;
943 para_list_add(&client->node, &afs_client_list);
944 }
945
946 static void register_command_task(uint32_t cookie)
947 {
948 struct command_task *ct = &command_task_struct;
949 ct->fd = setup_command_socket_or_die();
950 ct->cookie = cookie;
951
952 ct->task.pre_select = command_pre_select;
953 ct->task.post_select = command_post_select;
954 sprintf(ct->task.status, "command task");
955 register_task(&ct->task);
956 }
957
958 /**
959 * Initialize the audio file selector process.
960 *
961 * \param cookie The value used for "authentication".
962 * \param socket_fd File descriptor used for communication with the server.
963 */
964 __noreturn void afs_init(uint32_t cookie, int socket_fd)
965 {
966 static struct sched s;
967 int i, ret;
968
969 register_signal_task();
970 INIT_LIST_HEAD(&afs_client_list);
971 for (i = 0; i < NUM_AFS_TABLES; i++)
972 afs_tables[i].init(&afs_tables[i]);
973 ret = open_afs_tables();
974 if (ret < 0)
975 goto out;
976 server_socket = socket_fd;
977 ret = mark_fd_nonblocking(server_socket);
978 if (ret < 0)
979 goto out_close;
980 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
981 server_socket, (unsigned) cookie);
982 init_admissible_files(conf.afs_initial_mode_arg);
983 register_command_task(cookie);
984 s.default_timeout.tv_sec = 0;
985 s.default_timeout.tv_usec = 999 * 1000;
986 ret = schedule(&s);
987 out_close:
988 close_afs_tables();
989 out:
990 if (ret < 0)
991 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
992 exit(EXIT_FAILURE);
993 }
994
995 static void create_tables_callback(int fd, const struct osl_object *query)
996 {
997 uint32_t table_mask = *(uint32_t *)query->data;
998 int i, ret;
999 struct para_buffer pb = {.buf = NULL};
1000
1001 close_afs_tables();
1002 for (i = 0; i < NUM_AFS_TABLES; i++) {
1003 struct afs_table *t = &afs_tables[i];
1004
1005 if (!(table_mask & (1 << i)))
1006 continue;
1007 if (!t->create)
1008 continue;
1009 ret = t->create(database_dir);
1010 if (ret < 0)
1011 goto out;
1012 para_printf(&pb, "successfully created %s table\n", t->name);
1013 }
1014 ret = open_afs_tables();
1015 out:
1016 if (ret < 0)
1017 para_printf(&pb, "%s\n", para_strerror(-ret));
1018 if (pb.buf)
1019 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
1020 free(pb.buf);
1021 }
1022
1023 int com_init(struct rc4_context *rc4c, int argc, char * const * const argv)
1024 {
1025 int i, j, ret;
1026 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1027 struct osl_object query = {.data = &table_mask,
1028 .size = sizeof(table_mask)};
1029
1030 ret = make_database_dir();
1031 if (ret < 0)
1032 return ret;
1033 if (argc != 1) {
1034 table_mask = 0;
1035 for (i = 1; i < argc; i++) {
1036 for (j = 0; j < NUM_AFS_TABLES; j++) {
1037 struct afs_table *t = &afs_tables[j];
1038
1039 if (strcmp(argv[i], t->name))
1040 continue;
1041 table_mask |= (1 << j);
1042 break;
1043 }
1044 if (j == NUM_AFS_TABLES)
1045 return -E_BAD_TABLE_NAME;
1046 }
1047 }
1048 ret = send_callback_request(create_tables_callback, &query,
1049 rc4_send_result, rc4c);
1050 if (ret < 0)
1051 return rc4_send_va_buffer(rc4c, "%s\n", para_strerror(-ret));
1052 return ret;
1053 }
1054
1055 /**
1056 * Flags for the check command.
1057 *
1058 * \sa com_check().
1059 */
1060 enum com_check_flags {
1061 /** Check the audio file table. */
1062 CHECK_AFT = 1,
1063 /** Check the mood table. */
1064 CHECK_MOODS = 2,
1065 /** Check the playlist table. */
1066 CHECK_PLAYLISTS = 4
1067 };
1068
1069 int com_check(struct rc4_context *rc4c, int argc, char * const * const argv)
1070 {
1071 unsigned flags = 0;
1072 int i, ret;
1073
1074 for (i = 1; i < argc; i++) {
1075 const char *arg = argv[i];
1076 if (arg[0] != '-')
1077 break;
1078 if (!strcmp(arg, "--")) {
1079 i++;
1080 break;
1081 }
1082 if (!strcmp(arg, "-a")) {
1083 flags |= CHECK_AFT;
1084 continue;
1085 }
1086 if (!strcmp(arg, "-p")) {
1087 flags |= CHECK_PLAYLISTS;
1088 continue;
1089 }
1090 if (!strcmp(arg, "-m")) {
1091 flags |= CHECK_MOODS;
1092 continue;
1093 }
1094 return -E_AFS_SYNTAX;
1095 }
1096 if (i < argc)
1097 return -E_AFS_SYNTAX;
1098 if (!flags)
1099 flags = ~0U;
1100 if (flags & CHECK_AFT) {
1101 ret = send_callback_request(aft_check_callback, NULL,
1102 rc4_send_result, rc4c);
1103 if (ret < 0)
1104 return ret;
1105 }
1106 if (flags & CHECK_PLAYLISTS) {
1107 ret = send_callback_request(playlist_check_callback,
1108 NULL, rc4_send_result, rc4c);
1109 if (ret < 0)
1110 return ret;
1111 }
1112 if (flags & CHECK_MOODS) {
1113 ret = send_callback_request(mood_check_callback, NULL,
1114 rc4_send_result, rc4c);
1115 if (ret < 0)
1116 return ret;
1117 }
1118 return 1;
1119 }
1120
1121 /**
1122 * The afs event dispatcher.
1123 *
1124 * \param event Type of the event.
1125 * \param pb May be \p NULL.
1126 * \param data Type depends on \a event.
1127 *
1128 * This function calls the table handlers of all tables and passes \a pb and \a
1129 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1130 */
1131 void afs_event(enum afs_events event, struct para_buffer *pb,
1132 void *data)
1133 {
1134 int i, ret;
1135
1136 for (i = 0; i < NUM_AFS_TABLES; i++) {
1137 struct afs_table *t = &afs_tables[i];
1138 if (!t->event_handler)
1139 continue;
1140 ret = t->event_handler(event, pb, data);
1141 if (ret < 0)
1142 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1143 event, para_strerror(-ret));
1144 }
1145 }
1146
1147 /**
1148 * Dummy event handler for the images table.
1149 *
1150 * \param event Unused.
1151 * \param pb Unused.
1152 * \param data Unused.
1153 *
1154 * This table does not honor events.
1155 */
1156 int images_event_handler(__a_unused enum afs_events event,
1157 __a_unused struct para_buffer *pb, __a_unused void *data)
1158 {
1159 return 1;
1160 }
1161
1162 /**
1163 * Dummy event handler for the lyrics table.
1164 *
1165 * \param event Unused.
1166 * \param pb Unused.
1167 * \param data Unused.
1168 *
1169 * This table does not honor events.
1170 */
1171 int lyrics_event_handler(__a_unused enum afs_events event,
1172 __a_unused struct para_buffer *pb, __a_unused void *data)
1173 {
1174 return 1;
1175 }