afs: Introduce flush_and_free_pb().
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>
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 <netinet/in.h>
10 #include <sys/socket.h>
11 #include <regex.h>
12 #include <signal.h>
13 #include <fnmatch.h>
14 #include <osl.h>
15 #include <arpa/inet.h>
16 #include <sys/un.h>
17 #include <netdb.h>
18
19 #include "server.cmdline.h"
20 #include "para.h"
21 #include "error.h"
22 #include "crypt.h"
23 #include "string.h"
24 #include "afh.h"
25 #include "afs.h"
26 #include "server.h"
27 #include "net.h"
28 #include "ipc.h"
29 #include "list.h"
30 #include "sched.h"
31 #include "fd.h"
32 #include "signal.h"
33 #include "mood.h"
34 #include "sideband.h"
35 #include "command.h"
36
37 /** The osl tables used by afs. \sa blob.c. */
38 enum afs_table_num {
39 /** Contains audio file information. See aft.c. */
40 TBLNUM_AUDIO_FILES,
41 /** The table for the paraslash attributes. See attribute.c. */
42 TBLNUM_ATTRIBUTES,
43 /**
44 * Paraslash's scoring system is based on Gaussian normal
45 * distributions, and the relevant data is stored in the rbtrees of an
46 * osl table containing only volatile columns. See score.c for
47 * details.
48 */
49 TBLNUM_SCORES,
50 /**
51 * A standard blob table containing the mood definitions. For details
52 * see mood.c.
53 */
54 TBLNUM_MOODS,
55 /** A blob table containing lyrics on a per-song basis. */
56 TBLNUM_LYRICS,
57 /** Another blob table for images (for example album cover art). */
58 TBLNUM_IMAGES,
59 /** Yet another blob table for storing standard playlists. */
60 TBLNUM_PLAYLIST,
61 /** How many tables are in use? */
62 NUM_AFS_TABLES
63 };
64
65 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
66 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
67 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
68 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
69 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
70 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
71 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
72 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
73 };
74
75 struct command_task {
76 /** The file descriptor for the local socket. */
77 int fd;
78 /**
79 * Value sent by the command handlers to identify themselves as
80 * children of the running para_server.
81 */
82 uint32_t cookie;
83 /** The associated task structure. */
84 struct task *task;
85 };
86
87 extern int mmd_mutex;
88 extern struct misc_meta_data *mmd;
89
90 static int server_socket;
91 static struct command_task command_task_struct;
92 static struct signal_task *signal_task;
93
94 static enum play_mode current_play_mode;
95 static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
96
97 /**
98 * A random number used to "authenticate" the connection.
99 *
100 * para_server picks this number by random before forking the afs process. The
101 * command handlers write this number together with the id of the shared memory
102 * area containing the query. This way, a malicious local user has to know this
103 * number to be able to cause the afs process to crash by sending fake queries.
104 */
105 extern uint32_t afs_socket_cookie;
106
107 /**
108 * Struct to let command handlers execute a callback in afs context.
109 *
110 * Commands that need to change the state of afs can't change the relevant data
111 * structures directly because commands are executed in a child process, i.e.
112 * they get their own virtual address space.
113 *
114 * This structure is used by \p send_callback_request() (executed from handler
115 * context) in order to let the afs process call the specified function. An
116 * instance of that structure is written to a shared memory area together with
117 * the arguments to the callback function. The identifier of the shared memory
118 * area is written to the command socket.
119 *
120 * The afs process accepts connections on the command socket and reads the
121 * shared memory id, attaches the corresponding area, calls the given handler to
122 * perform the desired action and to optionally compute a result.
123 *
124 * The result and a \p callback_result structure is then written to another
125 * shared memory area. The identifier for that area is written to the handler's
126 * command socket, so that the handler process can read the id, attach the
127 * shared memory area and use the result.
128 *
129 * \sa struct callback_result.
130 */
131 struct callback_query {
132 /** The function to be called. */
133 callback_function *handler;
134 /** The number of bytes of the query */
135 size_t query_size;
136 };
137
138 /**
139 * Structure embedded in the result of a callback.
140 *
141 * If the callback produced a result, an instance of that structure is embedded
142 * into the shared memory area holding the result, mainly to let the command
143 * handler know the size of the result.
144 *
145 * \sa struct callback_query.
146 */
147 struct callback_result {
148 /** The number of bytes of the result. */
149 size_t result_size;
150 /** The band designator (loglevel for the result). */
151 uint8_t band;
152 };
153
154 static int dispatch_result(int result_shmid, callback_result_handler *handler,
155 void *private_result_data)
156 {
157 struct osl_object result;
158 void *result_shm;
159 /* must attach r/w as result.data might get encrypted in-place. */
160 int ret2, ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
161 struct callback_result *cr = result_shm;
162
163 if (ret < 0) {
164 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
165 return ret;
166 }
167 result.size = cr->result_size;
168 result.data = result_shm + sizeof(*cr);
169 if (result.size) {
170 assert(handler);
171 ret = handler(&result, cr->band, private_result_data);
172 if (ret < 0)
173 PARA_NOTICE_LOG("result handler error: %s\n",
174 para_strerror(-ret));
175 }
176 ret2 = shm_detach(result_shm);
177 if (ret2 < 0) {
178 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
179 if (ret >= 0)
180 ret = ret2;
181 }
182 return ret;
183 }
184
185 /**
186 * Ask the afs process to call a given function.
187 *
188 * \param f The function to be called.
189 * \param query Pointer to arbitrary data for the callback.
190 * \param result_handler Called for each shm area sent by the callback.
191 * \param private_result_data Passed verbatim to \a result_handler.
192 *
193 * This function creates a socket for communication with the afs process and a
194 * shared memory area (sma) to which the buffer pointed to by \a query is
195 * copied. It then notifies the afs process that the callback function \a f
196 * should be executed by sending the shared memory identifier (shmid) to the
197 * socket.
198 *
199 * If the callback produces a result, it sends any number of shared memory
200 * identifiers back via the socket. For each such identifier received, \a
201 * result_handler is called. The contents of the sma identified by the received
202 * shmid are passed to that function as an osl object. The private_result_data
203 * pointer is passed as the second argument to \a result_handler.
204 *
205 * \return Number of shared memory areas dispatched on success, negative on errors.
206 *
207 * \sa send_option_arg_callback_request(), send_standard_callback_request().
208 */
209 int send_callback_request(callback_function *f, struct osl_object *query,
210 callback_result_handler *result_handler,
211 void *private_result_data)
212 {
213 struct callback_query *cq;
214 int ret, fd = -1, query_shmid, result_shmid;
215 void *query_shm;
216 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
217 size_t query_shm_size = sizeof(*cq);
218 int dispatch_error = 0, num_dispatched = 0;
219
220 if (query)
221 query_shm_size += query->size;
222 ret = shm_new(query_shm_size);
223 if (ret < 0)
224 return ret;
225 query_shmid = ret;
226 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
227 if (ret < 0)
228 goto out;
229 cq = query_shm;
230 cq->handler = f;
231 cq->query_size = query_shm_size - sizeof(*cq);
232
233 if (query)
234 memcpy(query_shm + sizeof(*cq), query->data, query->size);
235 ret = shm_detach(query_shm);
236 if (ret < 0)
237 goto out;
238
239 *(uint32_t *)buf = afs_socket_cookie;
240 *(int *)(buf + sizeof(afs_socket_cookie)) = query_shmid;
241
242 ret = connect_local_socket(conf.afs_socket_arg);
243 if (ret < 0)
244 goto out;
245 fd = ret;
246 ret = write_all(fd, buf, sizeof(buf));
247 if (ret < 0)
248 goto out;
249 /*
250 * Read all shmids from afs.
251 *
252 * Even if the dispatcher returns an error we _must_ continue to read
253 * shmids from fd so that we can destroy all shared memory areas that
254 * have been created for us by the afs process.
255 */
256 for (;;) {
257 ret = recv_bin_buffer(fd, buf, sizeof(int));
258 if (ret <= 0)
259 goto out;
260 assert(ret == sizeof(int));
261 ret = *(int *) buf;
262 assert(ret > 0);
263 result_shmid = ret;
264 if (!dispatch_error) {
265 ret = dispatch_result(result_shmid, result_handler,
266 private_result_data);
267 if (ret < 0)
268 dispatch_error = 1;
269 }
270 ret = shm_destroy(result_shmid);
271 if (ret < 0)
272 PARA_CRIT_LOG("destroy result failed: %s\n",
273 para_strerror(-ret));
274 num_dispatched++;
275 }
276 out:
277 if (shm_destroy(query_shmid) < 0)
278 PARA_CRIT_LOG("shm destroy error\n");
279 if (fd >= 0)
280 close(fd);
281 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
282 return ret < 0? ret : num_dispatched;
283 }
284
285 /**
286 * Send a callback request passing an options structure and an argument vector.
287 *
288 * \param options pointer to an arbitrary data structure.
289 * \param argc Argument count.
290 * \param argv Standard argument vector.
291 * \param f The callback function.
292 * \param result_handler See \ref send_callback_request.
293 * \param private_result_data See \ref send_callback_request.
294 *
295 * Some command handlers pass command-specific options to a callback, together
296 * with a list of further arguments (often a list of audio files). This
297 * function allows to pass an arbitrary structure (given as an osl object) and
298 * a usual argument vector to the specified callback.
299 *
300 * \return The return value of the underlying call to \ref
301 * send_callback_request().
302 *
303 * \sa send_standard_callback_request(), send_callback_request().
304 */
305 int send_option_arg_callback_request(struct osl_object *options,
306 int argc, char * const * const argv, callback_function *f,
307 callback_result_handler *result_handler,
308 void *private_result_data)
309 {
310 char *p;
311 int i, ret;
312 struct osl_object query = {.size = options? options->size : 0};
313
314 for (i = 0; i < argc; i++)
315 query.size += strlen(argv[i]) + 1;
316 query.data = para_malloc(query.size);
317 p = query.data;
318 if (options) {
319 memcpy(query.data, options->data, options->size);
320 p += options->size;
321 }
322 for (i = 0; i < argc; i++) {
323 strcpy(p, argv[i]); /* OK */
324 p += strlen(argv[i]) + 1;
325 }
326 ret = send_callback_request(f, &query, result_handler,
327 private_result_data);
328 free(query.data);
329 return ret;
330 }
331
332 /**
333 * Send a callback request with an argument vector only.
334 *
335 * \param argc The same meaning as in send_option_arg_callback_request().
336 * \param argv The same meaning as in send_option_arg_callback_request().
337 * \param f The same meaning as in send_option_arg_callback_request().
338 * \param result_handler See \ref send_callback_request.
339 * \param private_result_data See \ref send_callback_request.
340 *
341 * This is similar to send_option_arg_callback_request(), but no options buffer
342 * is passed to the parent process.
343 *
344 * \return The return value of the underlying call to
345 * send_option_arg_callback_request().
346 */
347 int send_standard_callback_request(int argc, char * const * const argv,
348 callback_function *f, callback_result_handler *result_handler,
349 void *private_result_data)
350 {
351 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
352 private_result_data);
353 }
354
355 static int action_if_pattern_matches(struct osl_row *row, void *data)
356 {
357 struct pattern_match_data *pmd = data;
358 struct osl_object name_obj;
359 const char *p, *name;
360 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
361 const char *pattern_txt = (const char *)pmd->patterns.data;
362
363 if (ret < 0)
364 return ret;
365 name = (char *)name_obj.data;
366 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
367 return 1;
368 if (pmd->patterns.size == 0 &&
369 (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING)) {
370 pmd->num_matches++;
371 return pmd->action(pmd->table, row, name, pmd->data);
372 }
373 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
374 p += strlen(p) + 1) {
375 ret = fnmatch(p, name, pmd->fnmatch_flags);
376 if (ret == FNM_NOMATCH)
377 continue;
378 if (ret)
379 return -E_FNMATCH;
380 ret = pmd->action(pmd->table, row, name, pmd->data);
381 if (ret >= 0)
382 pmd->num_matches++;
383 return ret;
384 }
385 return 1;
386 }
387
388 /**
389 * Execute the given function for each matching row.
390 *
391 * \param pmd Describes what to match and how.
392 *
393 * \return Standard.
394 */
395 int for_each_matching_row(struct pattern_match_data *pmd)
396 {
397 if (pmd->pm_flags & PM_REVERSE_LOOP)
398 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
399 action_if_pattern_matches));
400 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
401 action_if_pattern_matches));
402 }
403
404 /**
405 * Compare two osl objects of string type.
406 *
407 * \param obj1 Pointer to the first object.
408 * \param obj2 Pointer to the second object.
409 *
410 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
411 * are taken into account.
412 *
413 * \return It returns an integer less than, equal to, or greater than zero if
414 * \a obj1 is found, respectively, to be less than, to match, or be greater than
415 * obj2.
416 *
417 * \sa strcmp(3), strncmp(3), osl_compare_func.
418 */
419 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
420 {
421 const char *str1 = (const char *)obj1->data;
422 const char *str2 = (const char *)obj2->data;
423 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
424 }
425
426 static int pass_afd(int fd, char *buf, size_t size)
427 {
428 struct msghdr msg = {.msg_iov = NULL};
429 struct cmsghdr *cmsg;
430 char control[255];
431 int ret;
432 struct iovec iov;
433
434 iov.iov_base = buf;
435 iov.iov_len = size;
436
437 msg.msg_iov = &iov;
438 msg.msg_iovlen = 1;
439
440 msg.msg_control = control;
441 msg.msg_controllen = sizeof(control);
442
443 cmsg = CMSG_FIRSTHDR(&msg);
444 cmsg->cmsg_level = SOL_SOCKET;
445 cmsg->cmsg_type = SCM_RIGHTS;
446 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
447 *(int *)CMSG_DATA(cmsg) = fd;
448
449 /* Sum of the length of all control messages in the buffer */
450 msg.msg_controllen = cmsg->cmsg_len;
451 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
452 ret = sendmsg(server_socket, &msg, 0);
453 if (ret < 0) {
454 ret = -ERRNO_TO_PARA_ERROR(errno);
455 return ret;
456 }
457 return 1;
458 }
459
460 /**
461 * Pass the fd of the next audio file to the server process.
462 *
463 * This stores all information for streaming the "best" audio file in a shared
464 * memory area. The id of that area and an open file descriptor for the next
465 * audio file are passed to the server process.
466 *
467 * \return Standard.
468 *
469 * \sa open_and_update_audio_file().
470 */
471 static int open_next_audio_file(void)
472 {
473 struct audio_file_data afd;
474 int ret, shmid;
475 char buf[8];
476
477 ret = open_and_update_audio_file(&afd);
478 if (ret < 0) {
479 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
480 goto no_admissible_files;
481 }
482 shmid = ret;
483 if (!write_ok(server_socket)) {
484 ret = -E_AFS_SOCKET;
485 goto destroy;
486 }
487 *(uint32_t *)buf = NEXT_AUDIO_FILE;
488 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
489 ret = pass_afd(afd.fd, buf, 8);
490 close(afd.fd);
491 if (ret >= 0)
492 return ret;
493 destroy:
494 shm_destroy(shmid);
495 return ret;
496 no_admissible_files:
497 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
498 *(uint32_t *)(buf + 4) = (uint32_t)0;
499 return write_all(server_socket, buf, 8);
500 }
501
502 /* Never fails if arg == NULL */
503 static int activate_mood_or_playlist(char *arg, int *num_admissible)
504 {
505 enum play_mode mode;
506 int ret;
507
508 if (!arg) {
509 ret = change_current_mood(NULL); /* always successful */
510 mode = PLAY_MODE_MOOD;
511 } else {
512 if (!strncmp(arg, "p/", 2)) {
513 ret = playlist_open(arg + 2);
514 mode = PLAY_MODE_PLAYLIST;
515 } else if (!strncmp(arg, "m/", 2)) {
516 ret = change_current_mood(arg + 2);
517 mode = PLAY_MODE_MOOD;
518 } else
519 return -E_AFS_SYNTAX;
520 if (ret < 0)
521 return ret;
522 }
523 if (num_admissible)
524 *num_admissible = ret;
525 current_play_mode = mode;
526 if (arg != current_mop) {
527 free(current_mop);
528 if (arg) {
529 current_mop = para_strdup(arg);
530 mutex_lock(mmd_mutex);
531 strncpy(mmd->afs_mode_string, arg,
532 sizeof(mmd->afs_mode_string));
533 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
534 mutex_unlock(mmd_mutex);
535 } else {
536 mutex_lock(mmd_mutex);
537 strcpy(mmd->afs_mode_string, "dummy");
538 mutex_unlock(mmd_mutex);
539 current_mop = NULL;
540 }
541 }
542 return 1;
543 }
544
545 /**
546 * Result handler for sending data to the para_client process.
547 *
548 * \param result The data to be sent.
549 * \param band The band designator.
550 * \param private Pointer to the command context.
551 *
552 * \return The return value of the underlying call to \ref command.c::send_sb.
553 *
554 * \sa \ref callback_result_handler, \ref command.c::send_sb.
555 */
556 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
557 void *private)
558 {
559 struct command_context *cc = private;
560
561 assert(cc);
562 if (!result->size)
563 return 1;
564 return send_sb(&cc->scc, result->data, result->size, band, true);
565 }
566
567 void flush_and_free_pb(struct para_buffer *pb)
568 {
569 int ret;
570 struct afs_max_size_handler_data *amshd = pb->private_data;
571
572 if (pb->buf && pb->size > 0) {
573 ret = pass_buffer_as_shm(amshd->fd, amshd->band, pb->buf,
574 pb->offset);
575 if (ret < 0)
576 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
577 }
578 free(pb->buf);
579 }
580
581 static void com_select_callback(int fd, const struct osl_object *query)
582 {
583 struct para_buffer pb = {
584 .max_size = shm_get_shmmax(),
585 .private_data = &(struct afs_max_size_handler_data) {
586 .fd = fd,
587 .band = SBD_OUTPUT
588 },
589 .max_size_handler = afs_max_size_handler,
590 };
591 char *arg = query->data;
592 int num_admissible, ret;
593
594 ret = clear_score_table();
595 if (ret < 0) {
596 para_printf(&pb, "%s\n", para_strerror(-ret));
597 goto out;
598 }
599 if (current_play_mode == PLAY_MODE_MOOD)
600 close_current_mood();
601 else
602 playlist_close();
603 ret = activate_mood_or_playlist(arg, &num_admissible);
604 if (ret < 0) {
605 para_printf(&pb, "%s\nswitching back to %s\n",
606 para_strerror(-ret), current_mop?
607 current_mop : "dummy");
608 ret = activate_mood_or_playlist(current_mop, &num_admissible);
609 if (ret < 0) {
610 para_printf(&pb, "failed (%s), switching to dummy\n",
611 para_strerror(-ret));
612 activate_mood_or_playlist(NULL, &num_admissible);
613 }
614 } else
615 para_printf(&pb, "activated %s (%d admissible files)\n",
616 current_mop? current_mop : "dummy mood",
617 num_admissible);
618 out:
619 flush_and_free_pb(&pb);
620 }
621
622 int com_select(struct command_context *cc)
623 {
624 struct osl_object query;
625
626 if (cc->argc != 2)
627 return -E_AFS_SYNTAX;
628 query.data = cc->argv[1];
629 query.size = strlen(cc->argv[1]) + 1;
630 return send_callback_request(com_select_callback, &query,
631 &afs_cb_result_handler, cc);
632 }
633
634 static void init_admissible_files(char *arg)
635 {
636 if (activate_mood_or_playlist(arg, NULL) < 0)
637 activate_mood_or_playlist(NULL, NULL); /* always successful */
638 }
639
640 static int setup_command_socket_or_die(void)
641 {
642 int ret, socket_fd;
643 char *socket_name = conf.afs_socket_arg;
644
645 unlink(socket_name);
646 ret = create_local_socket(socket_name, 0);
647 if (ret < 0) {
648 ret = create_local_socket(socket_name,
649 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
650 if (ret < 0) {
651 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret),
652 socket_name);
653 exit(EXIT_FAILURE);
654 }
655 }
656 socket_fd = ret;
657 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
658 socket_fd);
659 return socket_fd;
660 }
661
662 static void close_afs_tables(void)
663 {
664 int i;
665 PARA_NOTICE_LOG("closing afs_tables\n");
666 for (i = 0; i < NUM_AFS_TABLES; i++)
667 afs_tables[i].close();
668 }
669
670 static char *database_dir;
671
672 static void get_database_dir(void)
673 {
674 if (!database_dir) {
675 if (conf.afs_database_dir_given)
676 database_dir = para_strdup(conf.afs_database_dir_arg);
677 else {
678 char *home = para_homedir();
679 database_dir = make_message(
680 "%s/.paraslash/afs_database-0.4", home);
681 free(home);
682 }
683 }
684 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
685 }
686
687 static int make_database_dir(void)
688 {
689 int ret;
690
691 get_database_dir();
692 ret = para_mkdir(database_dir, 0777);
693 if (ret >= 0 || is_errno(-ret, EEXIST))
694 return 1;
695 return ret;
696 }
697
698 static int open_afs_tables(void)
699 {
700 int i, ret;
701
702 get_database_dir();
703 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
704 database_dir);
705 for (i = 0; i < NUM_AFS_TABLES; i++) {
706 ret = afs_tables[i].open(database_dir);
707 if (ret >= 0)
708 continue;
709 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
710 para_strerror(-ret));
711 break;
712 }
713 if (ret >= 0)
714 return ret;
715 while (i)
716 afs_tables[--i].close();
717 return ret;
718 }
719
720 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
721 {
722 int signum, ret;
723
724 if (getppid() == 1) {
725 PARA_EMERG_LOG("para_server died\n");
726 goto shutdown;
727 }
728 signum = para_next_signal(&s->rfds);
729 if (signum == 0)
730 return 0;
731 if (signum == SIGHUP) {
732 close_afs_tables();
733 parse_config_or_die(1);
734 ret = open_afs_tables();
735 if (ret < 0)
736 return ret;
737 init_admissible_files(current_mop);
738 return 0;
739 }
740 PARA_EMERG_LOG("terminating on signal %d\n", signum);
741 shutdown:
742 task_notify_all(s, E_AFS_SIGNAL);
743 return -E_AFS_SIGNAL;
744 }
745
746 static void register_signal_task(struct sched *s)
747 {
748 para_sigaction(SIGPIPE, SIG_IGN);
749 signal_task = signal_init_or_die();
750 para_install_sighandler(SIGINT);
751 para_install_sighandler(SIGTERM);
752 para_install_sighandler(SIGHUP);
753
754 signal_task->task = task_register(&(struct task_info) {
755 .name = "signal",
756 .pre_select = signal_pre_select,
757 .post_select = afs_signal_post_select,
758 .context = signal_task,
759
760 }, s);
761 }
762
763 static struct list_head afs_client_list;
764
765 /** Describes one connected afs client. */
766 struct afs_client {
767 /** Position in the afs client list. */
768 struct list_head node;
769 /** The socket file descriptor for this client. */
770 int fd;
771 /** The time the client connected. */
772 struct timeval connect_time;
773 };
774
775 static void command_pre_select(struct sched *s, void *context)
776 {
777 struct command_task *ct = context;
778 struct afs_client *client;
779
780 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
781 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
782 list_for_each_entry(client, &afs_client_list, node)
783 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
784 }
785
786 /**
787 * Send data as shared memory to a file descriptor.
788 *
789 * \param fd File descriptor to send the shmid to.
790 * \param band The band designator for this data.
791 * \param buf The buffer holding the data to be sent.
792 * \param size The size of \a buf.
793 *
794 * This function creates a shared memory area large enough to hold
795 * the content given by \a buf and \a size and sends the identifier
796 * of this area to the file descriptor \a fd.
797 *
798 * It is called by the AFS max_size handler as well as directly by the AFS
799 * command callbacks to send command output to the command handlers.
800 *
801 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
802 * and positive on success.
803 */
804 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
805 {
806 int ret, shmid;
807 void *shm;
808 struct callback_result *cr;
809
810 if (!buf || !size)
811 return 0;
812 ret = shm_new(size + sizeof(*cr));
813 if (ret < 0)
814 return ret;
815 shmid = ret;
816 ret = shm_attach(shmid, ATTACH_RW, &shm);
817 if (ret < 0)
818 goto err;
819 cr = shm;
820 cr->result_size = size;
821 cr->band = band;
822 memcpy(shm + sizeof(*cr), buf, size);
823 ret = shm_detach(shm);
824 if (ret < 0)
825 goto err;
826 ret = write_all(fd, (char *)&shmid, sizeof(int));
827 if (ret >= 0)
828 return ret;
829 err:
830 if (shm_destroy(shmid) < 0)
831 PARA_ERROR_LOG("destroy result failed\n");
832 return ret;
833 }
834
835 static int call_callback(int fd, int query_shmid)
836 {
837 void *query_shm;
838 struct callback_query *cq;
839 struct osl_object query;
840 int ret;
841
842 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
843 if (ret < 0)
844 return ret;
845 cq = query_shm;
846 query.data = (char *)query_shm + sizeof(*cq);
847 query.size = cq->query_size;
848 cq->handler(fd, &query);
849 return shm_detach(query_shm);
850 }
851
852 static int execute_server_command(fd_set *rfds)
853 {
854 char buf[8];
855 size_t n;
856 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
857
858 if (ret < 0 || n == 0)
859 return ret;
860 buf[n] = '\0';
861 if (strcmp(buf, "new"))
862 return -E_BAD_CMD;
863 return open_next_audio_file();
864 }
865
866 /* returns 0 if no data available, 1 else */
867 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
868 {
869 uint32_t cookie;
870 int query_shmid;
871 char buf[sizeof(cookie) + sizeof(query_shmid)];
872 size_t n;
873 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
874
875 if (ret < 0)
876 goto err;
877 if (n == 0)
878 return 0;
879 if (n != sizeof(buf)) {
880 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
881 ret, (long unsigned) sizeof(buf));
882 return 1;
883 }
884 cookie = *(uint32_t *)buf;
885 if (cookie != expected_cookie) {
886 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
887 (unsigned)cookie, (unsigned)expected_cookie);
888 return 1;
889 }
890 query_shmid = *(int *)(buf + sizeof(cookie));
891 if (query_shmid < 0) {
892 PARA_WARNING_LOG("received invalid query shmid %d)\n",
893 query_shmid);
894 return 1;
895 }
896 ret = call_callback(fd, query_shmid);
897 if (ret >= 0)
898 return 1;
899 err:
900 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
901 return 1;
902 }
903
904 /** Shutdown connection if query has not arrived until this many seconds. */
905 #define AFS_CLIENT_TIMEOUT 3
906
907 static int command_post_select(struct sched *s, void *context)
908 {
909 struct command_task *ct = context;
910 struct sockaddr_un unix_addr;
911 struct afs_client *client, *tmp;
912 int fd, ret;
913
914 ret = task_get_notification(ct->task);
915 if (ret < 0)
916 return ret;
917 ret = execute_server_command(&s->rfds);
918 if (ret < 0) {
919 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
920 task_notify_all(s, -ret);
921 return ret;
922 }
923 /* Check the list of connected clients. */
924 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
925 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
926 if (ret == 0) { /* prevent bogus connection flooding */
927 struct timeval diff;
928 tv_diff(now, &client->connect_time, &diff);
929 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
930 continue;
931 PARA_WARNING_LOG("connection timeout\n");
932 }
933 close(client->fd);
934 list_del(&client->node);
935 free(client);
936 }
937 /* Accept connections on the local socket. */
938 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
939 if (ret < 0)
940 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
941 if (ret <= 0)
942 return 0;
943 ret = mark_fd_nonblocking(fd);
944 if (ret < 0) {
945 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
946 close(fd);
947 return 0;
948 }
949 client = para_malloc(sizeof(*client));
950 client->fd = fd;
951 client->connect_time = *now;
952 para_list_add(&client->node, &afs_client_list);
953 return 0;
954 }
955
956 static void register_command_task(uint32_t cookie, struct sched *s)
957 {
958 struct command_task *ct = &command_task_struct;
959 ct->fd = setup_command_socket_or_die();
960 ct->cookie = cookie;
961
962 ct->task = task_register(&(struct task_info) {
963 .name = "afs command",
964 .pre_select = command_pre_select,
965 .post_select = command_post_select,
966 .context = ct,
967 }, s);
968 }
969
970 /**
971 * Initialize the audio file selector process.
972 *
973 * \param cookie The value used for "authentication".
974 * \param socket_fd File descriptor used for communication with the server.
975 */
976 __noreturn void afs_init(uint32_t cookie, int socket_fd)
977 {
978 static struct sched s;
979 int i, ret;
980
981 register_signal_task(&s);
982 INIT_LIST_HEAD(&afs_client_list);
983 for (i = 0; i < NUM_AFS_TABLES; i++)
984 afs_tables[i].init(&afs_tables[i]);
985 ret = open_afs_tables();
986 if (ret < 0)
987 goto out;
988 server_socket = socket_fd;
989 ret = mark_fd_nonblocking(server_socket);
990 if (ret < 0)
991 goto out_close;
992 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
993 server_socket, (unsigned) cookie);
994 init_admissible_files(conf.afs_initial_mode_arg);
995 register_command_task(cookie, &s);
996 s.default_timeout.tv_sec = 0;
997 s.default_timeout.tv_usec = 999 * 1000;
998 ret = schedule(&s);
999 sched_shutdown(&s);
1000 out_close:
1001 close_afs_tables();
1002 out:
1003 if (ret < 0)
1004 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1005 exit(EXIT_FAILURE);
1006 }
1007
1008 static void create_tables_callback(int fd, const struct osl_object *query)
1009 {
1010 uint32_t table_mask = *(uint32_t *)query->data;
1011 int i, ret;
1012 struct para_buffer pb = {
1013 .max_size = shm_get_shmmax(),
1014 .private_data = &(struct afs_max_size_handler_data) {
1015 .fd = fd,
1016 .band = SBD_OUTPUT
1017 }
1018 };
1019
1020 close_afs_tables();
1021 for (i = 0; i < NUM_AFS_TABLES; i++) {
1022 struct afs_table *t = &afs_tables[i];
1023
1024 if (!(table_mask & (1 << i)))
1025 continue;
1026 if (!t->create)
1027 continue;
1028 ret = t->create(database_dir);
1029 if (ret < 0)
1030 goto out;
1031 para_printf(&pb, "successfully created %s table\n", t->name);
1032 }
1033 ret = open_afs_tables();
1034 out:
1035 if (ret < 0)
1036 para_printf(&pb, "%s\n", para_strerror(-ret));
1037 flush_and_free_pb(&pb);
1038 }
1039
1040 int com_init(struct command_context *cc)
1041 {
1042 int i, j, ret;
1043 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1044 struct osl_object query = {.data = &table_mask,
1045 .size = sizeof(table_mask)};
1046
1047 ret = make_database_dir();
1048 if (ret < 0)
1049 return ret;
1050 if (cc->argc != 1) {
1051 table_mask = 0;
1052 for (i = 1; i < cc->argc; i++) {
1053 for (j = 0; j < NUM_AFS_TABLES; j++) {
1054 struct afs_table *t = &afs_tables[j];
1055
1056 if (strcmp(cc->argv[i], t->name))
1057 continue;
1058 table_mask |= (1 << j);
1059 break;
1060 }
1061 if (j == NUM_AFS_TABLES)
1062 return -E_BAD_TABLE_NAME;
1063 }
1064 }
1065 return send_callback_request(create_tables_callback, &query,
1066 afs_cb_result_handler, cc);
1067 }
1068
1069 /**
1070 * Flags for the check command.
1071 *
1072 * \sa com_check().
1073 */
1074 enum com_check_flags {
1075 /** Check the audio file table. */
1076 CHECK_AFT = 1,
1077 /** Check the mood table. */
1078 CHECK_MOODS = 2,
1079 /** Check the playlist table. */
1080 CHECK_PLAYLISTS = 4
1081 };
1082
1083 int com_check(struct command_context *cc)
1084 {
1085 unsigned flags = 0;
1086 int i, ret;
1087
1088 for (i = 1; i < cc->argc; i++) {
1089 const char *arg = cc->argv[i];
1090 if (arg[0] != '-')
1091 break;
1092 if (!strcmp(arg, "--")) {
1093 i++;
1094 break;
1095 }
1096 if (!strcmp(arg, "-a")) {
1097 flags |= CHECK_AFT;
1098 continue;
1099 }
1100 if (!strcmp(arg, "-p")) {
1101 flags |= CHECK_PLAYLISTS;
1102 continue;
1103 }
1104 if (!strcmp(arg, "-m")) {
1105 flags |= CHECK_MOODS;
1106 continue;
1107 }
1108 return -E_AFS_SYNTAX;
1109 }
1110 if (i < cc->argc)
1111 return -E_AFS_SYNTAX;
1112 if (!flags)
1113 flags = ~0U;
1114 if (flags & CHECK_AFT) {
1115 ret = send_callback_request(aft_check_callback, NULL,
1116 afs_cb_result_handler, cc);
1117 if (ret < 0)
1118 return ret;
1119 }
1120 if (flags & CHECK_PLAYLISTS) {
1121 ret = send_callback_request(playlist_check_callback,
1122 NULL, afs_cb_result_handler, cc);
1123 if (ret < 0)
1124 return ret;
1125 }
1126 if (flags & CHECK_MOODS) {
1127 ret = send_callback_request(mood_check_callback, NULL,
1128 afs_cb_result_handler, cc);
1129 if (ret < 0)
1130 return ret;
1131 }
1132 return 1;
1133 }
1134
1135 /**
1136 * The afs event dispatcher.
1137 *
1138 * \param event Type of the event.
1139 * \param pb May be \p NULL.
1140 * \param data Type depends on \a event.
1141 *
1142 * This function calls the table handlers of all tables and passes \a pb and \a
1143 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1144 */
1145 void afs_event(enum afs_events event, struct para_buffer *pb,
1146 void *data)
1147 {
1148 int i, ret;
1149
1150 for (i = 0; i < NUM_AFS_TABLES; i++) {
1151 struct afs_table *t = &afs_tables[i];
1152 if (!t->event_handler)
1153 continue;
1154 ret = t->event_handler(event, pb, data);
1155 if (ret < 0)
1156 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1157 event, para_strerror(-ret));
1158 }
1159 }
1160
1161 /**
1162 * Dummy event handler for the images table.
1163 *
1164 * \param event Unused.
1165 * \param pb Unused.
1166 * \param data Unused.
1167 *
1168 * \return The images table does not honor events, so this handler always
1169 * returns success.
1170 */
1171 __a_const int images_event_handler(__a_unused enum afs_events event,
1172 __a_unused struct para_buffer *pb, __a_unused void *data)
1173 {
1174 return 1;
1175 }
1176
1177 /**
1178 * Dummy event handler for the lyrics table.
1179 *
1180 * \param event Unused.
1181 * \param pb Unused.
1182 * \param data Unused.
1183 *
1184 * \return The lyrics table does not honor events, so this handler always
1185 * returns success.
1186 */
1187 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1188 __a_unused struct para_buffer *pb, __a_unused void *data)
1189 {
1190 return 1;
1191 }