sc_send_result(): Error out on short writes.
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2012 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 <osl.h>
13
14 #include "server.cmdline.h"
15 #include "para.h"
16 #include "error.h"
17 #include "crypt.h"
18 #include "string.h"
19 #include "afh.h"
20 #include "afs.h"
21 #include "server.h"
22 #include "net.h"
23 #include "ipc.h"
24 #include "list.h"
25 #include "sched.h"
26 #include "signal.h"
27 #include "fd.h"
28 #include "mood.h"
29
30 /** The osl tables used by afs. \sa blob.c. */
31 enum afs_table_num {
32 /** Contains audio file information. See aft.c. */
33 TBLNUM_AUDIO_FILES,
34 /** The table for the paraslash attributes. See attribute.c. */
35 TBLNUM_ATTRIBUTES,
36 /**
37 * Paraslash's scoring system is based on Gaussian normal
38 * distributions, and the relevant data is stored in the rbtrees of an
39 * osl table containing only volatile columns. See score.c for
40 * details.
41 */
42 TBLNUM_SCORES,
43 /**
44 * A standard blob table containing the mood definitions. For details
45 * see mood.c.
46 */
47 TBLNUM_MOODS,
48 /** A blob table containing lyrics on a per-song basis. */
49 TBLNUM_LYRICS,
50 /** Another blob table for images (for example album cover art). */
51 TBLNUM_IMAGES,
52 /** Yet another blob table for storing standard playlists. */
53 TBLNUM_PLAYLIST,
54 /** How many tables are in use? */
55 NUM_AFS_TABLES
56 };
57
58 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
59 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
60 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
61 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
62 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
63 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
64 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
65 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
66 };
67
68 struct command_task {
69 /** The file descriptor for the local socket. */
70 int fd;
71 /**
72 * Value sent by the command handlers to identify themselves as
73 * children of the running para_server.
74 */
75 uint32_t cookie;
76 /** The associated task structure. */
77 struct task task;
78 };
79
80 extern int mmd_mutex;
81 extern struct misc_meta_data *mmd;
82
83 static int server_socket;
84 static struct command_task command_task_struct;
85 static struct signal_task signal_task_struct;
86
87 static enum play_mode current_play_mode;
88 static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
89
90 /**
91 * A random number used to "authenticate" the connection.
92 *
93 * para_server picks this number by random before forking the afs process. The
94 * command handlers write this number together with the id of the shared memory
95 * area containing the query. This way, a malicious local user has to know this
96 * number to be able to cause the afs process to crash by sending fake queries.
97 */
98 extern uint32_t afs_socket_cookie;
99
100 /**
101 * Struct to let command handlers execute a callback in afs context.
102 *
103 * Commands that need to change the state of afs can't change the relevant data
104 * structures directly because commands are executed in a child process, i.e.
105 * they get their own virtual address space.
106 *
107 * This structure is used by \p send_callback_request() (executed from handler
108 * context) in order to let the afs process call the specified function. An
109 * instance of that structure is written to a shared memory area together with
110 * the arguments to the callback function. The identifier of the shared memory
111 * area is written to the command socket.
112 *
113 * The afs process accepts connections on the command socket and reads the
114 * shared memory id, attaches the corresponing area, calls the given handler to
115 * perform the desired action and to optionally compute a result.
116 *
117 * The result and a \p callback_result structure is then written to another
118 * shared memory area. The identifier for that area is written to the handler's
119 * command socket, so that the handler process can read the id, attach the
120 * shared memory area and use the result.
121 *
122 * \sa struct callback_result.
123 */
124 struct callback_query {
125 /** The function to be called. */
126 callback_function *handler;
127 /** The number of bytes of the query */
128 size_t query_size;
129 };
130
131 /**
132 * Structure embedded in the result of a callback.
133 *
134 * If the callback produced a result, an instance of that structure is embeeded
135 * into the shared memory area holding the result, mainly to let the command
136 * handler know the size of the result.
137 *
138 * \sa struct callback_query.
139 */
140 struct callback_result {
141 /** The number of bytes of the result. */
142 size_t result_size;
143 };
144
145 static int dispatch_result(int result_shmid, callback_result_handler *handler,
146 void *private_result_data)
147 {
148 struct osl_object result;
149 void *result_shm;
150 int ret2, ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
151 struct callback_result *cr = result_shm;
152
153 if (ret < 0) {
154 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
155 return ret;
156 }
157 result.size = cr->result_size;
158 result.data = result_shm + sizeof(*cr);
159 if (result.size) {
160 assert(handler);
161 ret = handler(&result, private_result_data);
162 if (ret < 0)
163 PARA_NOTICE_LOG("result handler error: %s\n",
164 para_strerror(-ret));
165 }
166 ret2 = shm_detach(result_shm);
167 if (ret2 < 0) {
168 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
169 if (ret >= 0)
170 ret = ret2;
171 }
172 return ret;
173 }
174
175 /**
176 * Ask the afs process to call a given function.
177 *
178 * \param f The function to be called.
179 * \param query Pointer to arbitrary data for the callback.
180 * \param result_handler Called for each shm area sent by the callback.
181 * \param private_result_data Passed verbatim to \a result_handler.
182 *
183 * This function creates a socket for communication with the afs process and a
184 * shared memory area (sma) to which the buffer pointed to by \a query is
185 * copied. It then notifies the afs process that the callback function \a f
186 * should be executed by sending the shared memory identifier (shmid) to the
187 * socket.
188
189 * If the callback produces a result, it sends any number of shared memory
190 * identifiers back via the socket. For each such identifier received, \a
191 * result_handler is called. The contents of the sma identified by the received
192 * shmid are passed to that function as an osl object. The private_result_data
193 * pointer is passed as the second argument to \a result_handler.
194 *
195 * \return Number of shared memory areas dispatched on success, negative on errors.
196 *
197 * \sa send_option_arg_callback_request(), send_standard_callback_request().
198 */
199 int send_callback_request(callback_function *f, struct osl_object *query,
200 callback_result_handler *result_handler,
201 void *private_result_data)
202 {
203 struct callback_query *cq;
204 int ret, fd = -1, query_shmid, result_shmid;
205 void *query_shm;
206 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
207 size_t query_shm_size = sizeof(*cq);
208 int dispatch_error = 0, num_dispatched = 0;
209
210 if (query)
211 query_shm_size += query->size;
212 ret = shm_new(query_shm_size);
213 if (ret < 0)
214 return ret;
215 query_shmid = ret;
216 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
217 if (ret < 0)
218 goto out;
219 cq = query_shm;
220 cq->handler = f;
221 cq->query_size = query_shm_size - sizeof(*cq);
222
223 if (query)
224 memcpy(query_shm + sizeof(*cq), query->data, query->size);
225 ret = shm_detach(query_shm);
226 if (ret < 0)
227 goto out;
228
229 *(uint32_t *) buf = afs_socket_cookie;
230 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
231
232 ret = connect_local_socket(conf.afs_socket_arg);
233 if (ret < 0)
234 goto out;
235 fd = ret;
236 ret = write_all(fd, buf, sizeof(buf));
237 if (ret < 0)
238 goto out;
239 /*
240 * Read all shmids from afs.
241 *
242 * Even if the dispatcher returns an error we _must_ continue to read
243 * shmids from fd so that we can destroy all shared memory areas that
244 * have been created for us by the afs process.
245 */
246 for (;;) {
247 ret = recv_bin_buffer(fd, buf, sizeof(int));
248 if (ret <= 0)
249 goto out;
250 assert(ret == sizeof(int));
251 ret = *(int *) buf;
252 assert(ret > 0);
253 result_shmid = ret;
254 if (!dispatch_error) {
255 ret = dispatch_result(result_shmid, result_handler,
256 private_result_data);
257 if (ret < 0)
258 dispatch_error = 1;
259 }
260 ret = shm_destroy(result_shmid);
261 if (ret < 0)
262 PARA_CRIT_LOG("destroy result failed: %s\n",
263 para_strerror(-ret));
264 num_dispatched++;
265 }
266 out:
267 if (shm_destroy(query_shmid) < 0)
268 PARA_CRIT_LOG("shm destroy error\n");
269 if (fd >= 0)
270 close(fd);
271 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
272 return ret < 0? ret : num_dispatched;
273 }
274
275 /**
276 * Send a callback request passing an options structure and an argument vector.
277 *
278 * \param options pointer to an arbitrary data structure.
279 * \param argc Argument count.
280 * \param argv Standard argument vector.
281 * \param f The callback function.
282 * \param result_handler See \ref send_callback_request.
283 * \param private_result_data See \ref send_callback_request.
284 *
285 * Some commands have a couple of options that are parsed in child context for
286 * syntactic correctness and are stored in a special options structure for that
287 * command. This function allows to pass such a structure together with a list
288 * of further arguments (often a list of audio files) to the parent process.
289 *
290 * \return The return value of the underlying call to \ref
291 * send_callback_request().
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 ret = pmd->action(pmd->table, row, name, pmd->data);
368 if (ret >= 0)
369 pmd->num_matches++;
370 return ret;
371 }
372 return 1;
373 }
374
375 /**
376 * Execute the given function for each matching row.
377 *
378 * \param pmd Describes what to match and how.
379 *
380 * \return Standard.
381 */
382 int for_each_matching_row(struct pattern_match_data *pmd)
383 {
384 if (pmd->pm_flags & PM_REVERSE_LOOP)
385 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
386 action_if_pattern_matches));
387 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
388 action_if_pattern_matches));
389 }
390
391 /**
392 * Compare two osl objects of string type.
393 *
394 * \param obj1 Pointer to the first object.
395 * \param obj2 Pointer to the second object.
396 *
397 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
398 * are taken into account.
399 *
400 * \return It returns an integer less than, equal to, or greater than zero if
401 * \a obj1 is found, respectively, to be less than, to match, or be greater than
402 * obj2.
403 *
404 * \sa strcmp(3), strncmp(3), osl_compare_func.
405 */
406 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
407 {
408 const char *str1 = (const char *)obj1->data;
409 const char *str2 = (const char *)obj2->data;
410 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
411 }
412
413 static int pass_afd(int fd, char *buf, size_t size)
414 {
415 struct msghdr msg = {.msg_iov = NULL};
416 struct cmsghdr *cmsg;
417 char control[255];
418 int ret;
419 struct iovec iov;
420
421 iov.iov_base = buf;
422 iov.iov_len = size;
423
424 msg.msg_iov = &iov;
425 msg.msg_iovlen = 1;
426
427 msg.msg_control = control;
428 msg.msg_controllen = sizeof(control);
429
430 cmsg = CMSG_FIRSTHDR(&msg);
431 cmsg->cmsg_level = SOL_SOCKET;
432 cmsg->cmsg_type = SCM_RIGHTS;
433 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
434 *(int *)CMSG_DATA(cmsg) = fd;
435
436 /* Sum of the length of all control messages in the buffer */
437 msg.msg_controllen = cmsg->cmsg_len;
438 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
439 ret = sendmsg(server_socket, &msg, 0);
440 if (ret < 0) {
441 ret = -ERRNO_TO_PARA_ERROR(errno);
442 return ret;
443 }
444 return 1;
445 }
446
447 /**
448 * Open the audio file with highest score.
449 *
450 * This stores all information for streaming the "best" audio file in a shared
451 * memory area. The id of that area and an open file descriptor for the next
452 * audio file are passed to the server process.
453 *
454 * \return Standard.
455 *
456 * \sa open_and_update_audio_file().
457 */
458 static int open_next_audio_file(void)
459 {
460 struct osl_row *aft_row;
461 struct audio_file_data afd;
462 int ret, shmid;
463 char buf[8];
464 long score;
465 again:
466 PARA_NOTICE_LOG("getting next audio file\n");
467 ret = score_get_best(&aft_row, &score);
468 if (ret < 0) {
469 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
470 goto no_admissible_files;
471 }
472 ret = open_and_update_audio_file(aft_row, score, &afd);
473 if (ret < 0) {
474 ret = score_delete(aft_row);
475 if (ret < 0) {
476 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
477 goto no_admissible_files;
478 }
479 goto again;
480 }
481 shmid = ret;
482 if (!write_ok(server_socket)) {
483 ret = -E_AFS_SOCKET;
484 goto destroy;
485 }
486 *(uint32_t *)buf = NEXT_AUDIO_FILE;
487 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
488 ret = pass_afd(afd.fd, buf, 8);
489 close(afd.fd);
490 if (ret >= 0)
491 return ret;
492 destroy:
493 shm_destroy(shmid);
494 return ret;
495 no_admissible_files:
496 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
497 *(uint32_t *)(buf + 4) = (uint32_t)0;
498 return write_all(server_socket, buf, 8);
499 }
500
501 /* Never fails if arg == NULL */
502 static int activate_mood_or_playlist(char *arg, int *num_admissible)
503 {
504 enum play_mode mode;
505 int ret;
506
507 if (!arg) {
508 ret = change_current_mood(NULL); /* always successful */
509 mode = PLAY_MODE_MOOD;
510 } else {
511 if (!strncmp(arg, "p/", 2)) {
512 ret = playlist_open(arg + 2);
513 mode = PLAY_MODE_PLAYLIST;
514 } else if (!strncmp(arg, "m/", 2)) {
515 ret = change_current_mood(arg + 2);
516 mode = PLAY_MODE_MOOD;
517 } else
518 return -E_AFS_SYNTAX;
519 if (ret < 0)
520 return ret;
521 }
522 if (num_admissible)
523 *num_admissible = ret;
524 current_play_mode = mode;
525 if (arg != current_mop) {
526 free(current_mop);
527 if (arg) {
528 current_mop = para_strdup(arg);
529 mutex_lock(mmd_mutex);
530 strncpy(mmd->afs_mode_string, arg,
531 sizeof(mmd->afs_mode_string));
532 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
533 mutex_unlock(mmd_mutex);
534 } else {
535 mutex_lock(mmd_mutex);
536 strcpy(mmd->afs_mode_string, "dummy");
537 mutex_unlock(mmd_mutex);
538 current_mop = NULL;
539 }
540 }
541 return 1;
542 }
543
544 static void com_select_callback(int fd, const struct osl_object *query)
545 {
546 struct para_buffer pb = {
547 .max_size = shm_get_shmmax(),
548 .private_data = &fd,
549 .max_size_handler = pass_buffer_as_shm
550 };
551 char *arg = query->data;
552 int num_admissible, ret, ret2;
553
554 ret = clear_score_table();
555 if (ret < 0) {
556 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
557 goto out;
558 }
559 if (current_play_mode == PLAY_MODE_MOOD)
560 close_current_mood();
561 else
562 playlist_close();
563 ret = activate_mood_or_playlist(arg, &num_admissible);
564 if (ret < 0) {
565 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
566 para_strerror(-ret), current_mop?
567 current_mop : "dummy");
568 ret = activate_mood_or_playlist(current_mop, &num_admissible);
569 if (ret < 0) {
570 if (ret2 >= 0)
571 ret2 = para_printf(&pb, "failed, switching to dummy\n");
572 activate_mood_or_playlist(NULL, &num_admissible);
573 }
574 } else
575 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
576 current_mop : "dummy mood", num_admissible);
577 out:
578 if (ret2 >= 0 && pb.offset)
579 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
580 free(pb.buf);
581 }
582
583 /**
584 * Result handler for sending data to the para_client process.
585 *
586 * \param result The data to be sent.
587 * \param private Pointer to the context.
588 *
589 * \return The return value of the underlying call to sc_send_bin_buffer().
590 *
591 * \sa \ref callback_result_handler, \ref sc_send_bin_buffer().
592 */
593 int sc_send_result(struct osl_object *result, void *private)
594 {
595 struct stream_cipher_context *scc = private;
596 int ret;
597
598 if (!result->size)
599 return 1;
600 ret = sc_send_bin_buffer(scc, result->data, result->size);
601 if (ret < 0 || ret == result->size)
602 return ret;
603 return -E_SHORT_WRITE;
604 }
605
606 int com_select(struct stream_cipher_context *scc, int argc, char * const * const argv)
607 {
608 struct osl_object query;
609
610 if (argc != 2)
611 return -E_AFS_SYNTAX;
612 query.data = argv[1];
613 query.size = strlen(argv[1]) + 1;
614 return send_callback_request(com_select_callback, &query,
615 &sc_send_result, scc);
616 }
617
618 static void init_admissible_files(char *arg)
619 {
620 if (activate_mood_or_playlist(arg, NULL) < 0)
621 activate_mood_or_playlist(NULL, NULL); /* always successful */
622 }
623
624 static int setup_command_socket_or_die(void)
625 {
626 int ret, socket_fd;
627 char *socket_name = conf.afs_socket_arg;
628 struct sockaddr_un unix_addr;
629
630 unlink(socket_name);
631 ret = create_local_socket(socket_name, &unix_addr,
632 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
633 if (ret < 0) {
634 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
635 exit(EXIT_FAILURE);
636 }
637 socket_fd = ret;
638 if (listen(socket_fd , 5) < 0) {
639 PARA_EMERG_LOG("can not listen on socket\n");
640 exit(EXIT_FAILURE);
641 }
642 ret = mark_fd_nonblocking(socket_fd);
643 if (ret < 0) {
644 close(socket_fd);
645 return ret;
646 }
647 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
648 socket_fd);
649 return socket_fd;
650 }
651
652 static void close_afs_tables(void)
653 {
654 int i;
655 PARA_NOTICE_LOG("closing afs_tables\n");
656 for (i = 0; i < NUM_AFS_TABLES; i++)
657 afs_tables[i].close();
658 }
659
660 static char *database_dir;
661
662 static void get_database_dir(void)
663 {
664 if (!database_dir) {
665 if (conf.afs_database_dir_given)
666 database_dir = para_strdup(conf.afs_database_dir_arg);
667 else {
668 char *home = para_homedir();
669 database_dir = make_message(
670 "%s/.paraslash/afs_database-0.4", home);
671 free(home);
672 }
673 }
674 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
675 }
676
677 static int make_database_dir(void)
678 {
679 int ret;
680
681 get_database_dir();
682 ret = para_mkdir(database_dir, 0777);
683 if (ret >= 0 || is_errno(-ret, EEXIST))
684 return 1;
685 return ret;
686 }
687
688 static int open_afs_tables(void)
689 {
690 int i, ret;
691
692 get_database_dir();
693 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
694 database_dir);
695 for (i = 0; i < NUM_AFS_TABLES; i++) {
696 ret = afs_tables[i].open(database_dir);
697 if (ret >= 0)
698 continue;
699 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
700 para_strerror(-ret));
701 break;
702 }
703 if (ret >= 0)
704 return ret;
705 while (i)
706 afs_tables[--i].close();
707 return ret;
708 }
709
710 static void signal_pre_select(struct sched *s, struct task *t)
711 {
712 struct signal_task *st = container_of(t, struct signal_task, task);
713 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
714 }
715
716 static void afs_signal_post_select(struct sched *s, struct task *t)
717 {
718 int signum;
719
720 if (getppid() == 1) {
721 PARA_EMERG_LOG("para_server died\n");
722 goto shutdown;
723 }
724 signum = para_next_signal(&s->rfds);
725 if (signum == 0)
726 return;
727 if (signum == SIGHUP) {
728 close_afs_tables();
729 parse_config_or_die(1);
730 t->error = open_afs_tables();
731 if (t->error < 0)
732 return;
733 init_admissible_files(current_mop);
734 return;
735 }
736 PARA_EMERG_LOG("terminating on signal %d\n", signum);
737 shutdown:
738 sched_shutdown(s);
739 t->error = -E_AFS_SIGNAL;
740 }
741
742 static void register_signal_task(struct sched *s)
743 {
744 struct signal_task *st = &signal_task_struct;
745
746 para_sigaction(SIGPIPE, SIG_IGN);
747 st->fd = para_signal_init();
748 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
749 para_install_sighandler(SIGINT);
750 para_install_sighandler(SIGTERM);
751 para_install_sighandler(SIGHUP);
752
753 st->task.pre_select = signal_pre_select;
754 st->task.post_select = afs_signal_post_select;
755 sprintf(st->task.status, "signal task");
756 register_task(s, &st->task);
757 }
758
759 static struct list_head afs_client_list;
760
761 /** Describes on connected afs client. */
762 struct afs_client {
763 /** Position in the afs client list. */
764 struct list_head node;
765 /** The socket file descriptor for this client. */
766 int fd;
767 /** The time the client connected. */
768 struct timeval connect_time;
769 };
770
771 static void command_pre_select(struct sched *s, struct task *t)
772 {
773 struct command_task *ct = container_of(t, struct command_task, task);
774 struct afs_client *client;
775
776 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
777 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
778 list_for_each_entry(client, &afs_client_list, node)
779 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
780 }
781
782 /**
783 * Send data as shared memory to a file descriptor.
784 *
785 * \param buf The buffer holding the data to be sent.
786 * \param size The size of \a buf.
787 * \param fd_ptr A pointer to the file descriptor.
788 *
789 * This function is used as the \a max_size handler in a \ref para_buffer
790 * structure. If used this way, it is called by \ref para_printf() whenever
791 * the buffer passed to para_printf() is about to exceed its maximal size.
792 *
793 * This function creates a shared memory area large enough to hold
794 * the content given by \a buf and \a size and sends the identifier
795 * of this area to the file descriptor given by \a fd_ptr.
796 *
797 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
798 * and positive on success.
799 */
800 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
801 {
802 int ret, shmid, fd = *(int *)fd_ptr;
803 void *shm;
804 struct callback_result *cr;
805
806 if (!buf || !size)
807 return 0;
808 ret = shm_new(size + sizeof(struct callback_result));
809 if (ret < 0)
810 return ret;
811 shmid = ret;
812 ret = shm_attach(shmid, ATTACH_RW, &shm);
813 if (ret < 0)
814 goto err;
815 cr = shm;
816 cr->result_size = size;
817 memcpy(shm + sizeof(*cr), buf, size);
818 ret = shm_detach(shm);
819 if (ret < 0)
820 goto err;
821 ret = write_all(fd, (char *)&shmid, sizeof(int));
822 if (ret >= 0)
823 return ret;
824 err:
825 if (shm_destroy(shmid) < 0)
826 PARA_ERROR_LOG("destroy result failed\n");
827 return ret;
828 }
829
830 /*
831 * On errors, negative value is written to fd.
832 * On success: If query produced a result, the result_shmid is written to fd.
833 * Otherwise, zero is written.
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 void command_post_select(struct sched *s, struct task *t)
908 {
909 struct command_task *ct = container_of(t, struct command_task, task);
910 struct sockaddr_un unix_addr;
911 struct afs_client *client, *tmp;
912 int fd, ret;
913
914 ret = execute_server_command(&s->rfds);
915 if (ret < 0) {
916 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
917 sched_shutdown(s);
918 return;
919 }
920 /* Check the list of connected clients. */
921 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
922 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
923 if (ret == 0) { /* prevent bogus connection flooding */
924 struct timeval diff;
925 tv_diff(now, &client->connect_time, &diff);
926 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
927 continue;
928 PARA_WARNING_LOG("connection timeout\n");
929 }
930 close(client->fd);
931 list_del(&client->node);
932 free(client);
933 }
934 /* Accept connections on the local socket. */
935 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
936 if (ret < 0)
937 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
938 if (ret <= 0)
939 return;
940 ret = mark_fd_nonblocking(fd);
941 if (ret < 0) {
942 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
943 close(fd);
944 return;
945 }
946 client = para_malloc(sizeof(*client));
947 client->fd = fd;
948 client->connect_time = *now;
949 para_list_add(&client->node, &afs_client_list);
950 }
951
952 static void register_command_task(uint32_t cookie, struct sched *s)
953 {
954 struct command_task *ct = &command_task_struct;
955 ct->fd = setup_command_socket_or_die();
956 ct->cookie = cookie;
957
958 ct->task.pre_select = command_pre_select;
959 ct->task.post_select = command_post_select;
960 sprintf(ct->task.status, "afs command task");
961 register_task(s, &ct->task);
962 }
963
964 /**
965 * Initialize the audio file selector process.
966 *
967 * \param cookie The value used for "authentication".
968 * \param socket_fd File descriptor used for communication with the server.
969 */
970 __noreturn void afs_init(uint32_t cookie, int socket_fd)
971 {
972 static struct sched s;
973 int i, ret;
974
975 register_signal_task(&s);
976 INIT_LIST_HEAD(&afs_client_list);
977 for (i = 0; i < NUM_AFS_TABLES; i++)
978 afs_tables[i].init(&afs_tables[i]);
979 ret = open_afs_tables();
980 if (ret < 0)
981 goto out;
982 server_socket = socket_fd;
983 ret = mark_fd_nonblocking(server_socket);
984 if (ret < 0)
985 goto out_close;
986 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
987 server_socket, (unsigned) cookie);
988 init_admissible_files(conf.afs_initial_mode_arg);
989 register_command_task(cookie, &s);
990 s.default_timeout.tv_sec = 0;
991 s.default_timeout.tv_usec = 999 * 1000;
992 ret = schedule(&s);
993 out_close:
994 close_afs_tables();
995 out:
996 if (ret < 0)
997 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
998 exit(EXIT_FAILURE);
999 }
1000
1001 static void create_tables_callback(int fd, const struct osl_object *query)
1002 {
1003 uint32_t table_mask = *(uint32_t *)query->data;
1004 int i, ret;
1005 struct para_buffer pb = {.buf = NULL};
1006
1007 close_afs_tables();
1008 for (i = 0; i < NUM_AFS_TABLES; i++) {
1009 struct afs_table *t = &afs_tables[i];
1010
1011 if (!(table_mask & (1 << i)))
1012 continue;
1013 if (!t->create)
1014 continue;
1015 ret = t->create(database_dir);
1016 if (ret < 0)
1017 goto out;
1018 para_printf(&pb, "successfully created %s table\n", t->name);
1019 }
1020 ret = open_afs_tables();
1021 out:
1022 if (ret < 0)
1023 para_printf(&pb, "%s\n", para_strerror(-ret));
1024 if (pb.buf)
1025 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
1026 free(pb.buf);
1027 }
1028
1029 int com_init(struct stream_cipher_context *scc, int argc, char * const * const argv)
1030 {
1031 int i, j, ret;
1032 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1033 struct osl_object query = {.data = &table_mask,
1034 .size = sizeof(table_mask)};
1035
1036 ret = make_database_dir();
1037 if (ret < 0)
1038 return ret;
1039 if (argc != 1) {
1040 table_mask = 0;
1041 for (i = 1; i < argc; i++) {
1042 for (j = 0; j < NUM_AFS_TABLES; j++) {
1043 struct afs_table *t = &afs_tables[j];
1044
1045 if (strcmp(argv[i], t->name))
1046 continue;
1047 table_mask |= (1 << j);
1048 break;
1049 }
1050 if (j == NUM_AFS_TABLES)
1051 return -E_BAD_TABLE_NAME;
1052 }
1053 }
1054 ret = send_callback_request(create_tables_callback, &query,
1055 sc_send_result, scc);
1056 if (ret < 0)
1057 /* ignore return value */
1058 sc_send_va_buffer(scc, "%s\n", para_strerror(-ret));
1059 return ret;
1060 }
1061
1062 /**
1063 * Flags for the check command.
1064 *
1065 * \sa com_check().
1066 */
1067 enum com_check_flags {
1068 /** Check the audio file table. */
1069 CHECK_AFT = 1,
1070 /** Check the mood table. */
1071 CHECK_MOODS = 2,
1072 /** Check the playlist table. */
1073 CHECK_PLAYLISTS = 4
1074 };
1075
1076 int com_check(struct stream_cipher_context *scc, int argc, char * const * const argv)
1077 {
1078 unsigned flags = 0;
1079 int i, ret;
1080
1081 for (i = 1; i < argc; i++) {
1082 const char *arg = argv[i];
1083 if (arg[0] != '-')
1084 break;
1085 if (!strcmp(arg, "--")) {
1086 i++;
1087 break;
1088 }
1089 if (!strcmp(arg, "-a")) {
1090 flags |= CHECK_AFT;
1091 continue;
1092 }
1093 if (!strcmp(arg, "-p")) {
1094 flags |= CHECK_PLAYLISTS;
1095 continue;
1096 }
1097 if (!strcmp(arg, "-m")) {
1098 flags |= CHECK_MOODS;
1099 continue;
1100 }
1101 return -E_AFS_SYNTAX;
1102 }
1103 if (i < argc)
1104 return -E_AFS_SYNTAX;
1105 if (!flags)
1106 flags = ~0U;
1107 if (flags & CHECK_AFT) {
1108 ret = send_callback_request(aft_check_callback, NULL,
1109 sc_send_result, scc);
1110 if (ret < 0)
1111 return ret;
1112 }
1113 if (flags & CHECK_PLAYLISTS) {
1114 ret = send_callback_request(playlist_check_callback,
1115 NULL, sc_send_result, scc);
1116 if (ret < 0)
1117 return ret;
1118 }
1119 if (flags & CHECK_MOODS) {
1120 ret = send_callback_request(mood_check_callback, NULL,
1121 sc_send_result, scc);
1122 if (ret < 0)
1123 return ret;
1124 }
1125 return 1;
1126 }
1127
1128 /**
1129 * The afs event dispatcher.
1130 *
1131 * \param event Type of the event.
1132 * \param pb May be \p NULL.
1133 * \param data Type depends on \a event.
1134 *
1135 * This function calls the table handlers of all tables and passes \a pb and \a
1136 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1137 */
1138 void afs_event(enum afs_events event, struct para_buffer *pb,
1139 void *data)
1140 {
1141 int i, ret;
1142
1143 for (i = 0; i < NUM_AFS_TABLES; i++) {
1144 struct afs_table *t = &afs_tables[i];
1145 if (!t->event_handler)
1146 continue;
1147 ret = t->event_handler(event, pb, data);
1148 if (ret < 0)
1149 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1150 event, para_strerror(-ret));
1151 }
1152 }
1153
1154 /**
1155 * Dummy event handler for the images table.
1156 *
1157 * \param event Unused.
1158 * \param pb Unused.
1159 * \param data Unused.
1160 *
1161 * \return The images table does not honor events, so this handler always
1162 * returns success.
1163 */
1164 __a_const int images_event_handler(__a_unused enum afs_events event,
1165 __a_unused struct para_buffer *pb, __a_unused void *data)
1166 {
1167 return 1;
1168 }
1169
1170 /**
1171 * Dummy event handler for the lyrics table.
1172 *
1173 * \param event Unused.
1174 * \param pb Unused.
1175 * \param data Unused.
1176 *
1177 * \return The lyrics table does not honor events, so this handler always
1178 * returns success.
1179 */
1180 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1181 __a_unused struct para_buffer *pb, __a_unused void *data)
1182 {
1183 return 1;
1184 }