Merge branch 't/testsuite'
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2011 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 ret = score_delete(aft_row);
472 if (ret < 0) {
473 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
474 goto no_admissible_files;
475 }
476 goto again;
477 }
478 shmid = ret;
479 if (!write_ok(server_socket)) {
480 ret = -E_AFS_SOCKET;
481 goto destroy;
482 }
483 *(uint32_t *)buf = NEXT_AUDIO_FILE;
484 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
485 ret = pass_afd(afd.fd, buf, 8);
486 close(afd.fd);
487 if (ret >= 0)
488 return ret;
489 destroy:
490 shm_destroy(shmid);
491 return ret;
492 no_admissible_files:
493 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
494 *(uint32_t *)(buf + 4) = (uint32_t)0;
495 return send_bin_buffer(server_socket, buf, 8);
496 }
497
498 /* Never fails if arg == NULL */
499 static int activate_mood_or_playlist(char *arg, int *num_admissible)
500 {
501 enum play_mode mode;
502 int ret;
503
504 if (!arg) {
505 ret = change_current_mood(NULL); /* always successful */
506 mode = PLAY_MODE_MOOD;
507 } else {
508 if (!strncmp(arg, "p/", 2)) {
509 ret = playlist_open(arg + 2);
510 mode = PLAY_MODE_PLAYLIST;
511 } else if (!strncmp(arg, "m/", 2)) {
512 ret = change_current_mood(arg + 2);
513 mode = PLAY_MODE_MOOD;
514 } else
515 return -E_AFS_SYNTAX;
516 if (ret < 0)
517 return ret;
518 }
519 if (num_admissible)
520 *num_admissible = ret;
521 current_play_mode = mode;
522 if (arg != current_mop) {
523 free(current_mop);
524 if (arg) {
525 current_mop = para_strdup(arg);
526 mutex_lock(mmd_mutex);
527 strncpy(mmd->afs_mode_string, arg,
528 sizeof(mmd->afs_mode_string));
529 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
530 mutex_unlock(mmd_mutex);
531 } else {
532 mutex_lock(mmd_mutex);
533 strcpy(mmd->afs_mode_string, "dummy");
534 mutex_unlock(mmd_mutex);
535 current_mop = NULL;
536 }
537 }
538 return 1;
539 }
540
541 static void com_select_callback(int fd, const struct osl_object *query)
542 {
543 struct para_buffer pb = {
544 .max_size = SHMMAX,
545 .private_data = &fd,
546 .max_size_handler = pass_buffer_as_shm
547 };
548 char *arg = query->data;
549 int num_admissible, ret, ret2;
550
551 ret = clear_score_table();
552 if (ret < 0) {
553 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
554 goto out;
555 }
556 if (current_play_mode == PLAY_MODE_MOOD)
557 close_current_mood();
558 else
559 playlist_close();
560 ret = activate_mood_or_playlist(arg, &num_admissible);
561 if (ret < 0) {
562 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
563 para_strerror(-ret), current_mop?
564 current_mop : "dummy");
565 ret = activate_mood_or_playlist(current_mop, &num_admissible);
566 if (ret < 0) {
567 if (ret2 >= 0)
568 ret2 = para_printf(&pb, "failed, switching to dummy\n");
569 activate_mood_or_playlist(NULL, &num_admissible);
570 }
571 } else
572 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
573 current_mop : "dummy mood", num_admissible);
574 out:
575 if (ret2 >= 0 && pb.offset)
576 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
577 free(pb.buf);
578 }
579
580 /**
581 * Result handler for sending data to the para_client process.
582 *
583 * \param result The data to be sent.
584 * \param private Pointer to rc4 context.
585 *
586 * \return The return value of the underlying call to rc4_send_bin_buffer().
587 *
588 * \sa \ref callback_result_handler, \ref rc4_send_bin_buffer().
589 */
590 int rc4_send_result(struct osl_object *result, void *private)
591 {
592 struct rc4_context *rc4c = private;
593
594 if (!result->size)
595 return 1;
596 return rc4_send_bin_buffer(rc4c, result->data, result->size);
597 }
598
599 int com_select(struct rc4_context *rc4c, int argc, char * const * const argv)
600 {
601 struct osl_object query;
602
603 if (argc != 2)
604 return -E_AFS_SYNTAX;
605 query.data = argv[1];
606 query.size = strlen(argv[1]) + 1;
607 return send_callback_request(com_select_callback, &query,
608 &rc4_send_result, rc4c);
609 }
610
611 static void init_admissible_files(char *arg)
612 {
613 if (activate_mood_or_playlist(arg, NULL) < 0)
614 activate_mood_or_playlist(NULL, NULL); /* always successful */
615 }
616
617 static int setup_command_socket_or_die(void)
618 {
619 int ret, socket_fd;
620 char *socket_name = conf.afs_socket_arg;
621 struct sockaddr_un unix_addr;
622
623 unlink(socket_name);
624 ret = create_local_socket(socket_name, &unix_addr,
625 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
626 if (ret < 0) {
627 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
628 exit(EXIT_FAILURE);
629 }
630 socket_fd = ret;
631 if (listen(socket_fd , 5) < 0) {
632 PARA_EMERG_LOG("can not listen on socket\n");
633 exit(EXIT_FAILURE);
634 }
635 ret = mark_fd_nonblocking(socket_fd);
636 if (ret < 0) {
637 close(socket_fd);
638 return ret;
639 }
640 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
641 socket_fd);
642 return socket_fd;
643 }
644
645 static void close_afs_tables(void)
646 {
647 int i;
648 PARA_NOTICE_LOG("closing afs_tables\n");
649 for (i = 0; i < NUM_AFS_TABLES; i++)
650 afs_tables[i].close();
651 }
652
653 static char *database_dir;
654
655 static void get_database_dir(void)
656 {
657 if (!database_dir) {
658 if (conf.afs_database_dir_given)
659 database_dir = para_strdup(conf.afs_database_dir_arg);
660 else {
661 char *home = para_homedir();
662 database_dir = make_message(
663 "%s/.paraslash/afs_database-0.4", home);
664 free(home);
665 }
666 }
667 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
668 }
669
670 static int make_database_dir(void)
671 {
672 int ret;
673
674 get_database_dir();
675 ret = para_mkdir(database_dir, 0777);
676 if (ret >= 0 || is_errno(-ret, EEXIST))
677 return 1;
678 return ret;
679 }
680
681 static int open_afs_tables(void)
682 {
683 int i, ret;
684
685 get_database_dir();
686 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
687 database_dir);
688 for (i = 0; i < NUM_AFS_TABLES; i++) {
689 ret = afs_tables[i].open(database_dir);
690 if (ret >= 0)
691 continue;
692 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
693 para_strerror(-ret));
694 break;
695 }
696 if (ret >= 0)
697 return ret;
698 while (i)
699 afs_tables[--i].close();
700 return ret;
701 }
702
703 static void signal_pre_select(struct sched *s, struct task *t)
704 {
705 struct signal_task *st = container_of(t, struct signal_task, task);
706 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
707 }
708
709 static void afs_signal_post_select(struct sched *s, struct task *t)
710 {
711 int signum;
712
713 if (getppid() == 1) {
714 PARA_EMERG_LOG("para_server died\n");
715 goto shutdown;
716 }
717 signum = para_next_signal(&s->rfds);
718 if (signum == 0)
719 return;
720 if (signum == SIGHUP) {
721 close_afs_tables();
722 parse_config_or_die(1);
723 t->error = open_afs_tables();
724 if (t->error < 0)
725 return;
726 init_admissible_files(current_mop);
727 return;
728 }
729 PARA_EMERG_LOG("terminating on signal %d\n", signum);
730 shutdown:
731 sched_shutdown();
732 t->error = -E_AFS_SIGNAL;
733 }
734
735 static void register_signal_task(void)
736 {
737 struct signal_task *st = &signal_task_struct;
738
739 para_sigaction(SIGPIPE, SIG_IGN);
740 st->fd = para_signal_init();
741 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
742 para_install_sighandler(SIGINT);
743 para_install_sighandler(SIGTERM);
744 para_install_sighandler(SIGHUP);
745
746 st->task.pre_select = signal_pre_select;
747 st->task.post_select = afs_signal_post_select;
748 sprintf(st->task.status, "signal task");
749 register_task(&st->task);
750 }
751
752 static struct list_head afs_client_list;
753
754 /** Describes on connected afs client. */
755 struct afs_client {
756 /** Position in the afs client list. */
757 struct list_head node;
758 /** The socket file descriptor for this client. */
759 int fd;
760 /** The time the client connected. */
761 struct timeval connect_time;
762 };
763
764 static void command_pre_select(struct sched *s, struct task *t)
765 {
766 struct command_task *ct = container_of(t, struct command_task, task);
767 struct afs_client *client;
768
769 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
770 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
771 list_for_each_entry(client, &afs_client_list, node)
772 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
773 }
774
775 /**
776 * Send data as shared memory to a file descriptor.
777 *
778 * \param buf The buffer holding the data to be sent.
779 * \param size The size of \a buf.
780 * \param fd_ptr A pointer to the file descriptor.
781 *
782 * This function is used as the \a max_size handler in a \ref para_buffer
783 * structure. If used this way, it is called by \ref para_printf() whenever
784 * the buffer passed to para_printf() is about to exceed its maximal size.
785 *
786 * This function creates a shared memory area large enough to hold
787 * the content given by \a buf and \a size and sends the identifier
788 * of this area to the file descriptor given by \a fd_ptr.
789 *
790 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
791 * and positive on success.
792 */
793 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
794 {
795 int ret, shmid, fd = *(int *)fd_ptr;
796 void *shm;
797 struct callback_result *cr;
798
799 if (!buf || !size)
800 return 0;
801 ret = shm_new(size + sizeof(struct callback_result));
802 if (ret < 0)
803 return ret;
804 shmid = ret;
805 ret = shm_attach(shmid, ATTACH_RW, &shm);
806 if (ret < 0)
807 goto err;
808 cr = shm;
809 cr->result_size = size;
810 memcpy(shm + sizeof(*cr), buf, size);
811 ret = shm_detach(shm);
812 if (ret < 0)
813 goto err;
814 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
815 if (ret >= 0)
816 return ret;
817 err:
818 if (shm_destroy(shmid) < 0)
819 PARA_ERROR_LOG("destroy result failed\n");
820 return ret;
821 }
822
823 /*
824 * On errors, negative value is written to fd.
825 * On success: If query produced a result, the result_shmid is written to fd.
826 * Otherwise, zero is written.
827 */
828 static int call_callback(int fd, int query_shmid)
829 {
830 void *query_shm;
831 struct callback_query *cq;
832 struct osl_object query;
833 int ret;
834
835 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
836 if (ret < 0)
837 return ret;
838 cq = query_shm;
839 query.data = (char *)query_shm + sizeof(*cq);
840 query.size = cq->query_size;
841 cq->handler(fd, &query);
842 return shm_detach(query_shm);
843 }
844
845 static int execute_server_command(fd_set *rfds)
846 {
847 char buf[8];
848 size_t n;
849 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
850
851 if (ret < 0 || n == 0)
852 return ret;
853 buf[n] = '\0';
854 if (strcmp(buf, "new"))
855 return -E_BAD_CMD;
856 return open_next_audio_file();
857 }
858
859 /* returns 0 if no data available, 1 else */
860 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
861 {
862 uint32_t cookie;
863 int query_shmid;
864 char buf[sizeof(cookie) + sizeof(query_shmid)];
865 size_t n;
866 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
867
868 if (ret < 0)
869 goto err;
870 if (n == 0)
871 return 0;
872 if (n != sizeof(buf)) {
873 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
874 ret, (long unsigned) sizeof(buf));
875 return 1;
876 }
877 cookie = *(uint32_t *)buf;
878 if (cookie != expected_cookie) {
879 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
880 (unsigned)cookie, (unsigned)expected_cookie);
881 return 1;
882 }
883 query_shmid = *(int *)(buf + sizeof(cookie));
884 if (query_shmid < 0) {
885 PARA_WARNING_LOG("received invalid query shmid %d)\n",
886 query_shmid);
887 return 1;
888 }
889 ret = call_callback(fd, query_shmid);
890 if (ret >= 0)
891 return 1;
892 err:
893 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
894 return 1;
895 }
896
897 /** Shutdown connection if query has not arrived until this many seconds. */
898 #define AFS_CLIENT_TIMEOUT 3
899
900 static void command_post_select(struct sched *s, struct task *t)
901 {
902 struct command_task *ct = container_of(t, struct command_task, task);
903 struct sockaddr_un unix_addr;
904 struct afs_client *client, *tmp;
905 int fd, ret;
906
907 ret = execute_server_command(&s->rfds);
908 if (ret < 0) {
909 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
910 sched_shutdown();
911 return;
912 }
913 /* Check the list of connected clients. */
914 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
915 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
916 if (ret == 0) { /* prevent bogus connection flooding */
917 struct timeval diff;
918 tv_diff(now, &client->connect_time, &diff);
919 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
920 continue;
921 PARA_WARNING_LOG("connection timeout\n");
922 }
923 close(client->fd);
924 list_del(&client->node);
925 free(client);
926 }
927 /* Accept connections on the local socket. */
928 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
929 if (ret < 0)
930 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
931 if (ret <= 0)
932 return;
933 ret = mark_fd_nonblocking(fd);
934 if (ret < 0) {
935 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
936 close(fd);
937 return;
938 }
939 client = para_malloc(sizeof(*client));
940 client->fd = fd;
941 client->connect_time = *now;
942 para_list_add(&client->node, &afs_client_list);
943 }
944
945 static void register_command_task(uint32_t cookie)
946 {
947 struct command_task *ct = &command_task_struct;
948 ct->fd = setup_command_socket_or_die();
949 ct->cookie = cookie;
950
951 ct->task.pre_select = command_pre_select;
952 ct->task.post_select = command_post_select;
953 sprintf(ct->task.status, "afs command task");
954 register_task(&ct->task);
955 }
956
957 /**
958 * Initialize the audio file selector process.
959 *
960 * \param cookie The value used for "authentication".
961 * \param socket_fd File descriptor used for communication with the server.
962 */
963 __noreturn void afs_init(uint32_t cookie, int socket_fd)
964 {
965 static struct sched s;
966 int i, ret;
967
968 register_signal_task();
969 INIT_LIST_HEAD(&afs_client_list);
970 for (i = 0; i < NUM_AFS_TABLES; i++)
971 afs_tables[i].init(&afs_tables[i]);
972 ret = open_afs_tables();
973 if (ret < 0)
974 goto out;
975 server_socket = socket_fd;
976 ret = mark_fd_nonblocking(server_socket);
977 if (ret < 0)
978 goto out_close;
979 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
980 server_socket, (unsigned) cookie);
981 init_admissible_files(conf.afs_initial_mode_arg);
982 register_command_task(cookie);
983 s.default_timeout.tv_sec = 0;
984 s.default_timeout.tv_usec = 999 * 1000;
985 ret = schedule(&s);
986 out_close:
987 close_afs_tables();
988 out:
989 if (ret < 0)
990 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
991 exit(EXIT_FAILURE);
992 }
993
994 static void create_tables_callback(int fd, const struct osl_object *query)
995 {
996 uint32_t table_mask = *(uint32_t *)query->data;
997 int i, ret;
998 struct para_buffer pb = {.buf = NULL};
999
1000 close_afs_tables();
1001 for (i = 0; i < NUM_AFS_TABLES; i++) {
1002 struct afs_table *t = &afs_tables[i];
1003
1004 if (!(table_mask & (1 << i)))
1005 continue;
1006 if (!t->create)
1007 continue;
1008 ret = t->create(database_dir);
1009 if (ret < 0)
1010 goto out;
1011 para_printf(&pb, "successfully created %s table\n", t->name);
1012 }
1013 ret = open_afs_tables();
1014 out:
1015 if (ret < 0)
1016 para_printf(&pb, "%s\n", para_strerror(-ret));
1017 if (pb.buf)
1018 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
1019 free(pb.buf);
1020 }
1021
1022 int com_init(struct rc4_context *rc4c, int argc, char * const * const argv)
1023 {
1024 int i, j, ret;
1025 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1026 struct osl_object query = {.data = &table_mask,
1027 .size = sizeof(table_mask)};
1028
1029 ret = make_database_dir();
1030 if (ret < 0)
1031 return ret;
1032 if (argc != 1) {
1033 table_mask = 0;
1034 for (i = 1; i < argc; i++) {
1035 for (j = 0; j < NUM_AFS_TABLES; j++) {
1036 struct afs_table *t = &afs_tables[j];
1037
1038 if (strcmp(argv[i], t->name))
1039 continue;
1040 table_mask |= (1 << j);
1041 break;
1042 }
1043 if (j == NUM_AFS_TABLES)
1044 return -E_BAD_TABLE_NAME;
1045 }
1046 }
1047 ret = send_callback_request(create_tables_callback, &query,
1048 rc4_send_result, rc4c);
1049 if (ret < 0)
1050 return rc4_send_va_buffer(rc4c, "%s\n", para_strerror(-ret));
1051 return ret;
1052 }
1053
1054 /**
1055 * Flags for the check command.
1056 *
1057 * \sa com_check().
1058 */
1059 enum com_check_flags {
1060 /** Check the audio file table. */
1061 CHECK_AFT = 1,
1062 /** Check the mood table. */
1063 CHECK_MOODS = 2,
1064 /** Check the playlist table. */
1065 CHECK_PLAYLISTS = 4
1066 };
1067
1068 int com_check(struct rc4_context *rc4c, int argc, char * const * const argv)
1069 {
1070 unsigned flags = 0;
1071 int i, ret;
1072
1073 for (i = 1; i < argc; i++) {
1074 const char *arg = argv[i];
1075 if (arg[0] != '-')
1076 break;
1077 if (!strcmp(arg, "--")) {
1078 i++;
1079 break;
1080 }
1081 if (!strcmp(arg, "-a")) {
1082 flags |= CHECK_AFT;
1083 continue;
1084 }
1085 if (!strcmp(arg, "-p")) {
1086 flags |= CHECK_PLAYLISTS;
1087 continue;
1088 }
1089 if (!strcmp(arg, "-m")) {
1090 flags |= CHECK_MOODS;
1091 continue;
1092 }
1093 return -E_AFS_SYNTAX;
1094 }
1095 if (i < argc)
1096 return -E_AFS_SYNTAX;
1097 if (!flags)
1098 flags = ~0U;
1099 if (flags & CHECK_AFT) {
1100 ret = send_callback_request(aft_check_callback, NULL,
1101 rc4_send_result, rc4c);
1102 if (ret < 0)
1103 return ret;
1104 }
1105 if (flags & CHECK_PLAYLISTS) {
1106 ret = send_callback_request(playlist_check_callback,
1107 NULL, rc4_send_result, rc4c);
1108 if (ret < 0)
1109 return ret;
1110 }
1111 if (flags & CHECK_MOODS) {
1112 ret = send_callback_request(mood_check_callback, NULL,
1113 rc4_send_result, rc4c);
1114 if (ret < 0)
1115 return ret;
1116 }
1117 return 1;
1118 }
1119
1120 /**
1121 * The afs event dispatcher.
1122 *
1123 * \param event Type of the event.
1124 * \param pb May be \p NULL.
1125 * \param data Type depends on \a event.
1126 *
1127 * This function calls the table handlers of all tables and passes \a pb and \a
1128 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1129 */
1130 void afs_event(enum afs_events event, struct para_buffer *pb,
1131 void *data)
1132 {
1133 int i, ret;
1134
1135 for (i = 0; i < NUM_AFS_TABLES; i++) {
1136 struct afs_table *t = &afs_tables[i];
1137 if (!t->event_handler)
1138 continue;
1139 ret = t->event_handler(event, pb, data);
1140 if (ret < 0)
1141 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1142 event, para_strerror(-ret));
1143 }
1144 }
1145
1146 /**
1147 * Dummy event handler for the images table.
1148 *
1149 * \param event Unused.
1150 * \param pb Unused.
1151 * \param data Unused.
1152 *
1153 * This table does not honor events.
1154 */
1155 int images_event_handler(__a_unused enum afs_events event,
1156 __a_unused struct para_buffer *pb, __a_unused void *data)
1157 {
1158 return 1;
1159 }
1160
1161 /**
1162 * Dummy event handler for the lyrics table.
1163 *
1164 * \param event Unused.
1165 * \param pb Unused.
1166 * \param data Unused.
1167 *
1168 * This table does not honor events.
1169 */
1170 int lyrics_event_handler(__a_unused enum afs_events event,
1171 __a_unused struct para_buffer *pb, __a_unused void *data)
1172 {
1173 return 1;
1174 }