afs: Pass sideband error packet on callback failures.
[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 assert(handler);
170 ret = handler(&result, cr->band, private_result_data);
171 ret2 = shm_detach(result_shm);
172 if (ret2 < 0) {
173 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
174 if (ret >= 0)
175 ret = ret2;
176 }
177 return ret;
178 }
179
180 /**
181 * Ask the afs process to call a given function.
182 *
183 * \param f The function to be called.
184 * \param query Pointer to arbitrary data for the callback.
185 * \param result_handler Called for each shm area sent by the callback.
186 * \param private_result_data Passed verbatim to \a result_handler.
187 *
188 * This function creates a socket for communication with the afs process and a
189 * shared memory area (sma) to which the buffer pointed to by \a query is
190 * copied. It then notifies the afs process that the callback function \a f
191 * should be executed by sending the shared memory identifier (shmid) to the
192 * socket.
193 *
194 * If the callback produces a result, it sends any number of shared memory
195 * identifiers back via the socket. For each such identifier received, \a
196 * result_handler is called. The contents of the sma identified by the received
197 * shmid are passed to that function as an osl object. The private_result_data
198 * pointer is passed as the second argument to \a result_handler.
199 *
200 * \return Number of shared memory areas dispatched on success, negative on errors.
201 *
202 * \sa send_option_arg_callback_request(), send_standard_callback_request().
203 */
204 int send_callback_request(callback_function *f, struct osl_object *query,
205 callback_result_handler *result_handler,
206 void *private_result_data)
207 {
208 struct callback_query *cq;
209 int ret, fd = -1, query_shmid, result_shmid;
210 void *query_shm;
211 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
212 size_t query_shm_size = sizeof(*cq);
213 int dispatch_error = 0, num_dispatched = 0;
214
215 if (query)
216 query_shm_size += query->size;
217 ret = shm_new(query_shm_size);
218 if (ret < 0)
219 return ret;
220 query_shmid = ret;
221 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
222 if (ret < 0)
223 goto out;
224 cq = query_shm;
225 cq->handler = f;
226 cq->query_size = query_shm_size - sizeof(*cq);
227
228 if (query)
229 memcpy(query_shm + sizeof(*cq), query->data, query->size);
230 ret = shm_detach(query_shm);
231 if (ret < 0)
232 goto out;
233
234 *(uint32_t *)buf = afs_socket_cookie;
235 *(int *)(buf + sizeof(afs_socket_cookie)) = query_shmid;
236
237 ret = connect_local_socket(conf.afs_socket_arg);
238 if (ret < 0)
239 goto out;
240 fd = ret;
241 ret = write_all(fd, buf, sizeof(buf));
242 if (ret < 0)
243 goto out;
244 /*
245 * Read all shmids from afs.
246 *
247 * Even if the dispatcher returns an error we _must_ continue to read
248 * shmids from fd so that we can destroy all shared memory areas that
249 * have been created for us by the afs process.
250 */
251 for (;;) {
252 ret = recv_bin_buffer(fd, buf, sizeof(int));
253 if (ret <= 0)
254 goto out;
255 assert(ret == sizeof(int));
256 ret = *(int *) buf;
257 assert(ret > 0);
258 result_shmid = ret;
259 ret = dispatch_result(result_shmid, result_handler,
260 private_result_data);
261 if (ret < 0 && dispatch_error >= 0)
262 dispatch_error = ret;
263 ret = shm_destroy(result_shmid);
264 if (ret < 0)
265 PARA_CRIT_LOG("destroy result failed: %s\n",
266 para_strerror(-ret));
267 num_dispatched++;
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 if (dispatch_error < 0)
275 return dispatch_error;
276 if (ret < 0)
277 return ret;
278 return num_dispatched;
279 }
280
281 /**
282 * Send a callback request passing an options structure and an argument vector.
283 *
284 * \param options pointer to an arbitrary data structure.
285 * \param argc Argument count.
286 * \param argv Standard argument vector.
287 * \param f The callback function.
288 * \param result_handler See \ref send_callback_request.
289 * \param private_result_data See \ref send_callback_request.
290 *
291 * Some command handlers pass command-specific options to a callback, together
292 * with a list of further arguments (often a list of audio files). This
293 * function allows to pass an arbitrary structure (given as an osl object) and
294 * a usual argument vector to the specified callback.
295 *
296 * \return The return value of the underlying call to \ref
297 * send_callback_request().
298 *
299 * \sa send_standard_callback_request(), send_callback_request().
300 */
301 int send_option_arg_callback_request(struct osl_object *options,
302 int argc, char * const * const argv, callback_function *f,
303 callback_result_handler *result_handler,
304 void *private_result_data)
305 {
306 char *p;
307 int i, ret;
308 struct osl_object query = {.size = options? options->size : 0};
309
310 for (i = 0; i < argc; i++)
311 query.size += strlen(argv[i]) + 1;
312 query.data = para_malloc(query.size);
313 p = query.data;
314 if (options) {
315 memcpy(query.data, options->data, options->size);
316 p += options->size;
317 }
318 for (i = 0; i < argc; i++) {
319 strcpy(p, argv[i]); /* OK */
320 p += strlen(argv[i]) + 1;
321 }
322 ret = send_callback_request(f, &query, result_handler,
323 private_result_data);
324 free(query.data);
325 return ret;
326 }
327
328 /**
329 * Send a callback request with an argument vector only.
330 *
331 * \param argc The same meaning as in send_option_arg_callback_request().
332 * \param argv The same meaning as in send_option_arg_callback_request().
333 * \param f The same meaning as in send_option_arg_callback_request().
334 * \param result_handler See \ref send_callback_request.
335 * \param private_result_data See \ref send_callback_request.
336 *
337 * This is similar to send_option_arg_callback_request(), but no options buffer
338 * is passed to the parent process.
339 *
340 * \return The return value of the underlying call to
341 * send_option_arg_callback_request().
342 */
343 int send_standard_callback_request(int argc, char * const * const argv,
344 callback_function *f, callback_result_handler *result_handler,
345 void *private_result_data)
346 {
347 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
348 private_result_data);
349 }
350
351 static int action_if_pattern_matches(struct osl_row *row, void *data)
352 {
353 struct pattern_match_data *pmd = data;
354 struct osl_object name_obj;
355 const char *p, *name;
356 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
357 const char *pattern_txt = (const char *)pmd->patterns.data;
358
359 if (ret < 0)
360 return ret;
361 name = (char *)name_obj.data;
362 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
363 return 1;
364 if (pmd->patterns.size == 0 &&
365 (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING)) {
366 pmd->num_matches++;
367 return pmd->action(pmd->table, row, name, pmd->data);
368 }
369 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
370 p += strlen(p) + 1) {
371 ret = fnmatch(p, name, pmd->fnmatch_flags);
372 if (ret == FNM_NOMATCH)
373 continue;
374 if (ret)
375 return -E_FNMATCH;
376 ret = pmd->action(pmd->table, row, name, pmd->data);
377 if (ret >= 0)
378 pmd->num_matches++;
379 return ret;
380 }
381 return 1;
382 }
383
384 /**
385 * Execute the given function for each matching row.
386 *
387 * \param pmd Describes what to match and how.
388 *
389 * \return Standard.
390 */
391 int for_each_matching_row(struct pattern_match_data *pmd)
392 {
393 if (pmd->pm_flags & PM_REVERSE_LOOP)
394 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
395 action_if_pattern_matches));
396 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
397 action_if_pattern_matches));
398 }
399
400 /**
401 * Compare two osl objects of string type.
402 *
403 * \param obj1 Pointer to the first object.
404 * \param obj2 Pointer to the second object.
405 *
406 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
407 * are taken into account.
408 *
409 * \return It returns an integer less than, equal to, or greater than zero if
410 * \a obj1 is found, respectively, to be less than, to match, or be greater than
411 * obj2.
412 *
413 * \sa strcmp(3), strncmp(3), osl_compare_func.
414 */
415 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
416 {
417 const char *str1 = (const char *)obj1->data;
418 const char *str2 = (const char *)obj2->data;
419 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
420 }
421
422 static int pass_afd(int fd, char *buf, size_t size)
423 {
424 struct msghdr msg = {.msg_iov = NULL};
425 struct cmsghdr *cmsg;
426 char control[255];
427 int ret;
428 struct iovec iov;
429
430 iov.iov_base = buf;
431 iov.iov_len = size;
432
433 msg.msg_iov = &iov;
434 msg.msg_iovlen = 1;
435
436 msg.msg_control = control;
437 msg.msg_controllen = sizeof(control);
438
439 cmsg = CMSG_FIRSTHDR(&msg);
440 cmsg->cmsg_level = SOL_SOCKET;
441 cmsg->cmsg_type = SCM_RIGHTS;
442 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
443 *(int *)CMSG_DATA(cmsg) = fd;
444
445 /* Sum of the length of all control messages in the buffer */
446 msg.msg_controllen = cmsg->cmsg_len;
447 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
448 ret = sendmsg(server_socket, &msg, 0);
449 if (ret < 0) {
450 ret = -ERRNO_TO_PARA_ERROR(errno);
451 return ret;
452 }
453 return 1;
454 }
455
456 /**
457 * Pass the fd of the next audio file to the server process.
458 *
459 * This stores all information for streaming the "best" audio file in a shared
460 * memory area. The id of that area and an open file descriptor for the next
461 * audio file are passed to the server process.
462 *
463 * \return Standard.
464 *
465 * \sa open_and_update_audio_file().
466 */
467 static int open_next_audio_file(void)
468 {
469 struct audio_file_data afd;
470 int ret, shmid;
471 char buf[8];
472
473 ret = open_and_update_audio_file(&afd);
474 if (ret < 0) {
475 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
476 goto no_admissible_files;
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 write_all(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 /**
542 * Result handler for sending data to the para_client process.
543 *
544 * \param result The data to be sent.
545 * \param band The band designator.
546 * \param private Pointer to the command context.
547 *
548 * \return The return value of the underlying call to \ref command.c::send_sb.
549 *
550 * \sa \ref callback_result_handler, \ref command.c::send_sb.
551 */
552 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
553 void *private)
554 {
555 struct command_context *cc = private;
556
557 assert(cc);
558 switch (band) {
559 case SBD_OUTPUT:
560 case SBD_DEBUG_LOG:
561 case SBD_INFO_LOG:
562 case SBD_NOTICE_LOG:
563 case SBD_WARNING_LOG:
564 case SBD_ERROR_LOG:
565 case SBD_CRIT_LOG:
566 case SBD_EMERG_LOG:
567 assert(result->size > 0);
568 return send_sb(&cc->scc, result->data, result->size, band, true);
569 case SBD_AFS_CB_FAILURE:
570 return *(int *)(result->data);
571 default:
572 return -E_BAD_BAND;
573 }
574 }
575
576 void flush_and_free_pb(struct para_buffer *pb)
577 {
578 int ret;
579 struct afs_max_size_handler_data *amshd = pb->private_data;
580
581 if (pb->buf && pb->size > 0) {
582 ret = pass_buffer_as_shm(amshd->fd, amshd->band, pb->buf,
583 pb->offset);
584 if (ret < 0)
585 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
586 }
587 free(pb->buf);
588 }
589
590 static int com_select_callback(int fd, const struct osl_object *query)
591 {
592 struct para_buffer pb = {
593 .max_size = shm_get_shmmax(),
594 .private_data = &(struct afs_max_size_handler_data) {
595 .fd = fd,
596 .band = SBD_OUTPUT
597 },
598 .max_size_handler = afs_max_size_handler,
599 };
600 char *arg = query->data;
601 int num_admissible, ret;
602
603 ret = clear_score_table();
604 if (ret < 0) {
605 para_printf(&pb, "%s\n", para_strerror(-ret));
606 goto out;
607 }
608 if (current_play_mode == PLAY_MODE_MOOD)
609 close_current_mood();
610 else
611 playlist_close();
612 ret = activate_mood_or_playlist(arg, &num_admissible);
613 if (ret < 0) {
614 para_printf(&pb, "%s\nswitching back to %s\n",
615 para_strerror(-ret), current_mop?
616 current_mop : "dummy");
617 ret = activate_mood_or_playlist(current_mop, &num_admissible);
618 if (ret < 0) {
619 para_printf(&pb, "failed (%s), switching to dummy\n",
620 para_strerror(-ret));
621 activate_mood_or_playlist(NULL, &num_admissible);
622 }
623 } else
624 para_printf(&pb, "activated %s (%d admissible files)\n",
625 current_mop? current_mop : "dummy mood",
626 num_admissible);
627 out:
628 flush_and_free_pb(&pb);
629 return 0;
630 }
631
632 int com_select(struct command_context *cc)
633 {
634 struct osl_object query;
635
636 if (cc->argc != 2)
637 return -E_AFS_SYNTAX;
638 query.data = cc->argv[1];
639 query.size = strlen(cc->argv[1]) + 1;
640 return send_callback_request(com_select_callback, &query,
641 &afs_cb_result_handler, cc);
642 }
643
644 static void init_admissible_files(char *arg)
645 {
646 if (activate_mood_or_playlist(arg, NULL) < 0)
647 activate_mood_or_playlist(NULL, NULL); /* always successful */
648 }
649
650 static int setup_command_socket_or_die(void)
651 {
652 int ret, socket_fd;
653 char *socket_name = conf.afs_socket_arg;
654
655 unlink(socket_name);
656 ret = create_local_socket(socket_name, 0);
657 if (ret < 0) {
658 ret = create_local_socket(socket_name,
659 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
660 if (ret < 0) {
661 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret),
662 socket_name);
663 exit(EXIT_FAILURE);
664 }
665 }
666 socket_fd = ret;
667 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
668 socket_fd);
669 return socket_fd;
670 }
671
672 static void close_afs_tables(void)
673 {
674 int i;
675 PARA_NOTICE_LOG("closing afs_tables\n");
676 for (i = 0; i < NUM_AFS_TABLES; i++)
677 afs_tables[i].close();
678 }
679
680 static char *database_dir;
681
682 static void get_database_dir(void)
683 {
684 if (!database_dir) {
685 if (conf.afs_database_dir_given)
686 database_dir = para_strdup(conf.afs_database_dir_arg);
687 else {
688 char *home = para_homedir();
689 database_dir = make_message(
690 "%s/.paraslash/afs_database-0.4", home);
691 free(home);
692 }
693 }
694 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
695 }
696
697 static int make_database_dir(void)
698 {
699 int ret;
700
701 get_database_dir();
702 ret = para_mkdir(database_dir, 0777);
703 if (ret >= 0 || is_errno(-ret, EEXIST))
704 return 1;
705 return ret;
706 }
707
708 static int open_afs_tables(void)
709 {
710 int i, ret;
711
712 get_database_dir();
713 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
714 database_dir);
715 for (i = 0; i < NUM_AFS_TABLES; i++) {
716 ret = afs_tables[i].open(database_dir);
717 if (ret >= 0)
718 continue;
719 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
720 para_strerror(-ret));
721 break;
722 }
723 if (ret >= 0)
724 return ret;
725 while (i)
726 afs_tables[--i].close();
727 return ret;
728 }
729
730 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
731 {
732 int signum, ret;
733
734 if (getppid() == 1) {
735 PARA_EMERG_LOG("para_server died\n");
736 goto shutdown;
737 }
738 signum = para_next_signal(&s->rfds);
739 if (signum == 0)
740 return 0;
741 if (signum == SIGHUP) {
742 close_afs_tables();
743 parse_config_or_die(1);
744 ret = open_afs_tables();
745 if (ret < 0)
746 return ret;
747 init_admissible_files(current_mop);
748 return 0;
749 }
750 PARA_EMERG_LOG("terminating on signal %d\n", signum);
751 shutdown:
752 task_notify_all(s, E_AFS_SIGNAL);
753 return -E_AFS_SIGNAL;
754 }
755
756 static void register_signal_task(struct sched *s)
757 {
758 para_sigaction(SIGPIPE, SIG_IGN);
759 signal_task = signal_init_or_die();
760 para_install_sighandler(SIGINT);
761 para_install_sighandler(SIGTERM);
762 para_install_sighandler(SIGHUP);
763
764 signal_task->task = task_register(&(struct task_info) {
765 .name = "signal",
766 .pre_select = signal_pre_select,
767 .post_select = afs_signal_post_select,
768 .context = signal_task,
769
770 }, s);
771 }
772
773 static struct list_head afs_client_list;
774
775 /** Describes one connected afs client. */
776 struct afs_client {
777 /** Position in the afs client list. */
778 struct list_head node;
779 /** The socket file descriptor for this client. */
780 int fd;
781 /** The time the client connected. */
782 struct timeval connect_time;
783 };
784
785 static void command_pre_select(struct sched *s, void *context)
786 {
787 struct command_task *ct = context;
788 struct afs_client *client;
789
790 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
791 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
792 list_for_each_entry(client, &afs_client_list, node)
793 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
794 }
795
796 /**
797 * Send data as shared memory to a file descriptor.
798 *
799 * \param fd File descriptor to send the shmid to.
800 * \param band The band designator for this data.
801 * \param buf The buffer holding the data to be sent.
802 * \param size The size of \a buf.
803 *
804 * This function creates a shared memory area large enough to hold
805 * the content given by \a buf and \a size and sends the identifier
806 * of this area to the file descriptor \a fd.
807 *
808 * It is called by the AFS max_size handler as well as directly by the AFS
809 * command callbacks to send command output to the command handlers.
810 *
811 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
812 * and positive on success.
813 */
814 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
815 {
816 int ret, shmid;
817 void *shm;
818 struct callback_result *cr;
819
820 if (size == 0)
821 assert(band != SBD_OUTPUT);
822 ret = shm_new(size + sizeof(*cr));
823 if (ret < 0)
824 return ret;
825 shmid = ret;
826 ret = shm_attach(shmid, ATTACH_RW, &shm);
827 if (ret < 0)
828 goto err;
829 cr = shm;
830 cr->result_size = size;
831 cr->band = band;
832 if (size > 0)
833 memcpy(shm + sizeof(*cr), buf, size);
834 ret = shm_detach(shm);
835 if (ret < 0)
836 goto err;
837 ret = write_all(fd, (char *)&shmid, sizeof(int));
838 if (ret >= 0)
839 return ret;
840 err:
841 if (shm_destroy(shmid) < 0)
842 PARA_ERROR_LOG("destroy result failed\n");
843 return ret;
844 }
845
846 static int call_callback(int fd, int query_shmid)
847 {
848 void *query_shm;
849 struct callback_query *cq;
850 struct osl_object query;
851 int ret, ret2;
852
853 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
854 if (ret < 0)
855 return ret;
856 cq = query_shm;
857 query.data = (char *)query_shm + sizeof(*cq);
858 query.size = cq->query_size;
859 ret = cq->handler(fd, &query);
860 ret2 = shm_detach(query_shm);
861 if (ret2 < 0) {
862 if (ret < 0) /* ignore (but log) detach error */
863 PARA_ERROR_LOG("could not detach sma: %s\n",
864 para_strerror(-ret2));
865 else
866 ret = ret2;
867 }
868 if (ret < 0) {
869 ret2 = pass_buffer_as_shm(fd, SBD_AFS_CB_FAILURE,
870 (const char *)&ret, sizeof(ret));
871 if (ret2 < 0)
872 PARA_ERROR_LOG("could not pass cb failure packet: %s\n",
873 para_strerror(-ret));
874 }
875 return ret;
876 }
877
878 static int execute_server_command(fd_set *rfds)
879 {
880 char buf[8];
881 size_t n;
882 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
883
884 if (ret < 0 || n == 0)
885 return ret;
886 buf[n] = '\0';
887 if (strcmp(buf, "new"))
888 return -E_BAD_CMD;
889 return open_next_audio_file();
890 }
891
892 /* returns 0 if no data available, 1 else */
893 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
894 {
895 uint32_t cookie;
896 int query_shmid;
897 char buf[sizeof(cookie) + sizeof(query_shmid)];
898 size_t n;
899 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
900
901 if (ret < 0)
902 goto err;
903 if (n == 0)
904 return 0;
905 if (n != sizeof(buf)) {
906 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
907 ret, (long unsigned) sizeof(buf));
908 return 1;
909 }
910 cookie = *(uint32_t *)buf;
911 if (cookie != expected_cookie) {
912 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
913 (unsigned)cookie, (unsigned)expected_cookie);
914 return 1;
915 }
916 query_shmid = *(int *)(buf + sizeof(cookie));
917 if (query_shmid < 0) {
918 PARA_WARNING_LOG("received invalid query shmid %d)\n",
919 query_shmid);
920 return 1;
921 }
922 ret = call_callback(fd, query_shmid);
923 if (ret >= 0)
924 return 1;
925 err:
926 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
927 return 1;
928 }
929
930 /** Shutdown connection if query has not arrived until this many seconds. */
931 #define AFS_CLIENT_TIMEOUT 3
932
933 static int command_post_select(struct sched *s, void *context)
934 {
935 struct command_task *ct = context;
936 struct sockaddr_un unix_addr;
937 struct afs_client *client, *tmp;
938 int fd, ret;
939
940 ret = task_get_notification(ct->task);
941 if (ret < 0)
942 return ret;
943 ret = execute_server_command(&s->rfds);
944 if (ret < 0) {
945 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
946 task_notify_all(s, -ret);
947 return ret;
948 }
949 /* Check the list of connected clients. */
950 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
951 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
952 if (ret == 0) { /* prevent bogus connection flooding */
953 struct timeval diff;
954 tv_diff(now, &client->connect_time, &diff);
955 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
956 continue;
957 PARA_WARNING_LOG("connection timeout\n");
958 }
959 close(client->fd);
960 list_del(&client->node);
961 free(client);
962 }
963 /* Accept connections on the local socket. */
964 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
965 if (ret < 0)
966 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
967 if (ret <= 0)
968 return 0;
969 ret = mark_fd_nonblocking(fd);
970 if (ret < 0) {
971 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
972 close(fd);
973 return 0;
974 }
975 client = para_malloc(sizeof(*client));
976 client->fd = fd;
977 client->connect_time = *now;
978 para_list_add(&client->node, &afs_client_list);
979 return 0;
980 }
981
982 static void register_command_task(uint32_t cookie, struct sched *s)
983 {
984 struct command_task *ct = &command_task_struct;
985 ct->fd = setup_command_socket_or_die();
986 ct->cookie = cookie;
987
988 ct->task = task_register(&(struct task_info) {
989 .name = "afs command",
990 .pre_select = command_pre_select,
991 .post_select = command_post_select,
992 .context = ct,
993 }, s);
994 }
995
996 /**
997 * Initialize the audio file selector process.
998 *
999 * \param cookie The value used for "authentication".
1000 * \param socket_fd File descriptor used for communication with the server.
1001 */
1002 __noreturn void afs_init(uint32_t cookie, int socket_fd)
1003 {
1004 static struct sched s;
1005 int i, ret;
1006
1007 register_signal_task(&s);
1008 INIT_LIST_HEAD(&afs_client_list);
1009 for (i = 0; i < NUM_AFS_TABLES; i++)
1010 afs_tables[i].init(&afs_tables[i]);
1011 ret = open_afs_tables();
1012 if (ret < 0)
1013 goto out;
1014 server_socket = socket_fd;
1015 ret = mark_fd_nonblocking(server_socket);
1016 if (ret < 0)
1017 goto out_close;
1018 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1019 server_socket, (unsigned) cookie);
1020 init_admissible_files(conf.afs_initial_mode_arg);
1021 register_command_task(cookie, &s);
1022 s.default_timeout.tv_sec = 0;
1023 s.default_timeout.tv_usec = 999 * 1000;
1024 ret = schedule(&s);
1025 sched_shutdown(&s);
1026 out_close:
1027 close_afs_tables();
1028 out:
1029 if (ret < 0)
1030 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1031 exit(EXIT_FAILURE);
1032 }
1033
1034 static int create_tables_callback(int fd, const struct osl_object *query)
1035 {
1036 uint32_t table_mask = *(uint32_t *)query->data;
1037 int i, ret;
1038 struct para_buffer pb = {
1039 .max_size = shm_get_shmmax(),
1040 .private_data = &(struct afs_max_size_handler_data) {
1041 .fd = fd,
1042 .band = SBD_OUTPUT
1043 }
1044 };
1045
1046 close_afs_tables();
1047 for (i = 0; i < NUM_AFS_TABLES; i++) {
1048 struct afs_table *t = &afs_tables[i];
1049
1050 if (!(table_mask & (1 << i)))
1051 continue;
1052 if (!t->create)
1053 continue;
1054 ret = t->create(database_dir);
1055 if (ret < 0)
1056 goto out;
1057 para_printf(&pb, "successfully created %s table\n", t->name);
1058 }
1059 ret = open_afs_tables();
1060 out:
1061 if (ret < 0)
1062 para_printf(&pb, "%s\n", para_strerror(-ret));
1063 flush_and_free_pb(&pb);
1064 return 0;
1065 }
1066
1067 int com_init(struct command_context *cc)
1068 {
1069 int i, j, ret;
1070 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1071 struct osl_object query = {.data = &table_mask,
1072 .size = sizeof(table_mask)};
1073
1074 ret = make_database_dir();
1075 if (ret < 0)
1076 return ret;
1077 if (cc->argc != 1) {
1078 table_mask = 0;
1079 for (i = 1; i < cc->argc; i++) {
1080 for (j = 0; j < NUM_AFS_TABLES; j++) {
1081 struct afs_table *t = &afs_tables[j];
1082
1083 if (strcmp(cc->argv[i], t->name))
1084 continue;
1085 table_mask |= (1 << j);
1086 break;
1087 }
1088 if (j == NUM_AFS_TABLES)
1089 return -E_BAD_TABLE_NAME;
1090 }
1091 }
1092 return send_callback_request(create_tables_callback, &query,
1093 afs_cb_result_handler, cc);
1094 }
1095
1096 /**
1097 * Flags for the check command.
1098 *
1099 * \sa com_check().
1100 */
1101 enum com_check_flags {
1102 /** Check the audio file table. */
1103 CHECK_AFT = 1,
1104 /** Check the mood table. */
1105 CHECK_MOODS = 2,
1106 /** Check the playlist table. */
1107 CHECK_PLAYLISTS = 4
1108 };
1109
1110 int com_check(struct command_context *cc)
1111 {
1112 unsigned flags = 0;
1113 int i, ret;
1114
1115 for (i = 1; i < cc->argc; i++) {
1116 const char *arg = cc->argv[i];
1117 if (arg[0] != '-')
1118 break;
1119 if (!strcmp(arg, "--")) {
1120 i++;
1121 break;
1122 }
1123 if (!strcmp(arg, "-a")) {
1124 flags |= CHECK_AFT;
1125 continue;
1126 }
1127 if (!strcmp(arg, "-p")) {
1128 flags |= CHECK_PLAYLISTS;
1129 continue;
1130 }
1131 if (!strcmp(arg, "-m")) {
1132 flags |= CHECK_MOODS;
1133 continue;
1134 }
1135 return -E_AFS_SYNTAX;
1136 }
1137 if (i < cc->argc)
1138 return -E_AFS_SYNTAX;
1139 if (!flags)
1140 flags = ~0U;
1141 if (flags & CHECK_AFT) {
1142 ret = send_callback_request(aft_check_callback, NULL,
1143 afs_cb_result_handler, cc);
1144 if (ret < 0)
1145 return ret;
1146 }
1147 if (flags & CHECK_PLAYLISTS) {
1148 ret = send_callback_request(playlist_check_callback,
1149 NULL, afs_cb_result_handler, cc);
1150 if (ret < 0)
1151 return ret;
1152 }
1153 if (flags & CHECK_MOODS) {
1154 ret = send_callback_request(mood_check_callback, NULL,
1155 afs_cb_result_handler, cc);
1156 if (ret < 0)
1157 return ret;
1158 }
1159 return 1;
1160 }
1161
1162 /**
1163 * The afs event dispatcher.
1164 *
1165 * \param event Type of the event.
1166 * \param pb May be \p NULL.
1167 * \param data Type depends on \a event.
1168 *
1169 * This function calls the table handlers of all tables and passes \a pb and \a
1170 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1171 */
1172 void afs_event(enum afs_events event, struct para_buffer *pb,
1173 void *data)
1174 {
1175 int i, ret;
1176
1177 for (i = 0; i < NUM_AFS_TABLES; i++) {
1178 struct afs_table *t = &afs_tables[i];
1179 if (!t->event_handler)
1180 continue;
1181 ret = t->event_handler(event, pb, data);
1182 if (ret < 0)
1183 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1184 event, para_strerror(-ret));
1185 }
1186 }
1187
1188 /**
1189 * Dummy event handler for the images table.
1190 *
1191 * \param event Unused.
1192 * \param pb Unused.
1193 * \param data Unused.
1194 *
1195 * \return The images table does not honor events, so this handler always
1196 * returns success.
1197 */
1198 __a_const int images_event_handler(__a_unused enum afs_events event,
1199 __a_unused struct para_buffer *pb, __a_unused void *data)
1200 {
1201 return 1;
1202 }
1203
1204 /**
1205 * Dummy event handler for the lyrics table.
1206 *
1207 * \param event Unused.
1208 * \param pb Unused.
1209 * \param data Unused.
1210 *
1211 * \return The lyrics table does not honor events, so this handler always
1212 * returns success.
1213 */
1214 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1215 __a_unused struct para_buffer *pb, __a_unused void *data)
1216 {
1217 return 1;
1218 }