Merge branch 'master' into next
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2009 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 <signal.h>
10 #include <fnmatch.h>
11 #include "server.cmdline.h"
12 #include "para.h"
13 #include "error.h"
14 #include "string.h"
15 #include "afh.h"
16 #include "afs.h"
17 #include "server.h"
18 #include <dirent.h> /* readdir() */
19 #include <sys/mman.h>
20 #include <sys/time.h>
21 #include "net.h"
22 #include "ipc.h"
23 #include "list.h"
24 #include "sched.h"
25 #include "signal.h"
26 #include "fd.h"
27
28 /** The osl tables used by afs. \sa blob.c. */
29 enum afs_table_num {
30 /** Contains audio file information. See aft.c. */
31 TBLNUM_AUDIO_FILES,
32 /** The table for the paraslash attributes. See attribute.c. */
33 TBLNUM_ATTRIBUTES,
34 /**
35 * Paraslash's scoring system is based on Gaussian normal
36 * distributions, and the relevant data is stored in the rbtrees of an
37 * osl table containing only volatile columns. See score.c for
38 * details.
39 */
40 TBLNUM_SCORES,
41 /**
42 * A standard blob table containing the mood definitions. For details
43 * see mood.c.
44 */
45 TBLNUM_MOODS,
46 /** A blob table containing lyrics on a per-song basis. */
47 TBLNUM_LYRICS,
48 /** Another blob table for images (for example album cover art). */
49 TBLNUM_IMAGES,
50 /** Yet another blob table for storing standard playlists. */
51 TBLNUM_PLAYLIST,
52 /** How many tables are in use? */
53 NUM_AFS_TABLES
54 };
55
56 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
57 [TBLNUM_AUDIO_FILES] = {.init = aft_init},
58 [TBLNUM_ATTRIBUTES] = {.init = attribute_init},
59 [TBLNUM_SCORES] = {.init = score_init},
60 [TBLNUM_MOODS] = {.init = moods_init},
61 [TBLNUM_LYRICS] = {.init = lyrics_init},
62 [TBLNUM_IMAGES] = {.init = images_init},
63 [TBLNUM_PLAYLIST] = {.init = playlists_init},
64 };
65
66 struct command_task {
67 /** The file descriptor for the local socket. */
68 int fd;
69 /**
70 * Value sent by the command handlers to identify themselves as
71 * children of the running para_server.
72 */
73 uint32_t cookie;
74 /** The associated task structure. */
75 struct task task;
76 };
77
78 extern int mmd_mutex;
79 extern struct misc_meta_data *mmd;
80
81 static int server_socket;
82 static struct command_task command_task_struct;
83 static struct signal_task signal_task_struct;
84
85 static enum play_mode current_play_mode;
86 static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
87
88
89 /**
90 * A random number used to "authenticate" the connection.
91 *
92 * para_server picks this number by random before forking the afs process. The
93 * command handlers write this number together with the id of the shared memory
94 * area containing the query. This way, a malicious local user has to know this
95 * number to be able to cause the afs process to crash by sending fake queries.
96 */
97 extern uint32_t afs_socket_cookie;
98
99 /**
100 * Struct to let command handlers execute a callback in afs context.
101 *
102 * Commands that need to change the state of afs can't change the relevant data
103 * structures directly because commands are executed in a child process, i.e.
104 * they get their own virtual address space.
105 *
106 * This structure is used by \p send_callback_request() (executed from handler
107 * context) in order to let the afs process call the specified function. An
108 * instance of that structure is written to a shared memory area together with
109 * the arguments to the callback function. The identifier of the shared memory
110 * area is written to the command socket.
111 *
112 * The afs process accepts connections on the command socket and reads the
113 * shared memory id, attaches the corresponing area, calls the given handler to
114 * perform the desired action and to optionally compute a result.
115 *
116 * The result and a \p callback_result structure is then written to another
117 * shared memory area. The identifier for that area is written to the handler's
118 * command socket, so that the handler process can read the id, attach the
119 * shared memory area and use the result.
120 *
121 * \sa struct callback_result.
122 */
123 struct callback_query {
124 /** The function to be called. */
125 callback_function *handler;
126 /** The number of bytes of the query */
127 size_t query_size;
128 };
129
130 /**
131 * Structure embedded in the result of a callback.
132 *
133 * If the callback produced a result, an instance of that structure is embeeded
134 * into the shared memory area holding the result, mainly to let the command
135 * handler know the size of the result.
136 *
137 * \sa struct callback_query.
138 */
139 struct callback_result {
140 /** The number of bytes of the result. */
141 size_t result_size;
142 };
143
144 static int dispatch_result(int result_shmid, callback_result_handler *handler,
145 void *private_result_data)
146 {
147 struct osl_object result;
148 void *result_shm;
149 int ret2, ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
150 struct callback_result *cr = result_shm;
151
152 if (ret < 0) {
153 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
154 return ret;
155 }
156 result.size = cr->result_size;
157 result.data = result_shm + sizeof(*cr);
158 if (result.size) {
159 assert(handler);
160 ret = handler(&result, private_result_data);
161 if (ret < 0)
162 PARA_NOTICE_LOG("result handler error: %s\n",
163 para_strerror(-ret));
164 }
165 ret2 = shm_detach(result_shm);
166 if (ret2 < 0) {
167 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
168 if (ret >= 0)
169 ret = ret2;
170 }
171 return ret;
172 }
173
174 /**
175 * Ask the afs process to call a given function.
176 *
177 * \param f The function to be called.
178 * \param query Pointer to arbitrary data for the callback.
179 * \param result_handler Called for each shm area sent by the callback.
180 * \param private_result_data Passed verbatim to \a result_handler.
181 *
182 * This function creates a socket for communication with the afs process and a
183 * shared memory area (sma) to which the buffer pointed to by \a query is
184 * copied. It then notifies the afs process that the callback function \a f
185 * should be executed by sending the shared memory identifier (shmid) to the
186 * socket.
187
188 * If the callback produces a result, it sends any number of shared memory
189 * identifiers back via the socket. For each such identifier received, \a
190 * result_handler is called. The contents of the sma identified by the received
191 * shmid are passed to that function as an osl object. The private_result_data
192 * pointer is passed as the second argument to \a result_handler.
193 *
194 * \return Standard.
195 *
196 * \sa send_option_arg_callback_request(), send_standard_callback_request().
197 */
198 int send_callback_request(callback_function *f, struct osl_object *query,
199 callback_result_handler *result_handler,
200 void *private_result_data)
201 {
202 struct callback_query *cq;
203 int ret, fd = -1, query_shmid, result_shmid;
204 void *query_shm;
205 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
206 size_t query_shm_size = sizeof(*cq);
207 int dispatch_error = 0;
208
209 if (query)
210 query_shm_size += query->size;
211 ret = shm_new(query_shm_size);
212 if (ret < 0)
213 return ret;
214 query_shmid = ret;
215 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
216 if (ret < 0)
217 goto out;
218 cq = query_shm;
219 cq->handler = f;
220 cq->query_size = query_shm_size - sizeof(*cq);
221
222 if (query)
223 memcpy(query_shm + sizeof(*cq), query->data, query->size);
224 ret = shm_detach(query_shm);
225 if (ret < 0)
226 goto out;
227
228 *(uint32_t *) buf = afs_socket_cookie;
229 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
230
231 ret = create_remote_socket(conf.afs_socket_arg);
232 if (ret < 0)
233 goto out;
234 fd = ret;
235 ret = send_bin_buffer(fd, buf, sizeof(buf));
236 if (ret < 0)
237 goto out;
238 /*
239 * Read all shmids from afs.
240 *
241 * Even if the dispatcher returns an error we _must_ continue to read
242 * shmids from fd so that we can destroy all shared memory areas that
243 * have been created for us by the afs process.
244 */
245 for (;;) {
246 ret = recv_bin_buffer(fd, buf, sizeof(int));
247 if (ret <= 0)
248 goto out;
249 assert(ret == sizeof(int));
250 ret = *(int *) buf;
251 assert(ret > 0);
252 result_shmid = ret;
253 if (!dispatch_error) {
254 ret = dispatch_result(result_shmid, result_handler,
255 private_result_data);
256 if (ret < 0)
257 dispatch_error = 1;
258 }
259 ret = shm_destroy(result_shmid);
260 if (ret < 0)
261 PARA_CRIT_LOG("destroy result failed: %s\n",
262 para_strerror(-ret));
263 }
264 out:
265 if (shm_destroy(query_shmid) < 0)
266 PARA_CRIT_LOG("shm destroy error\n");
267 if (fd >= 0)
268 close(fd);
269 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
270 return ret;
271 }
272
273 /**
274 * Send a callback request passing an options structure and an argument vector.
275 *
276 * \param options pointer to an arbitrary data structure.
277 * \param argc Argument count.
278 * \param argv Standard argument vector.
279 * \param f The callback function.
280 * \param result_handler See \ref send_callback_request.
281 * \param private_result_data See \ref send_callback_request.
282 *
283 * Some commands have a couple of options that are parsed in child context for
284 * syntactic correctness and are stored in a special options structure for that
285 * command. This function allows to pass such a structure together with a list
286 * of further arguments (often a list of audio files) to the parent process.
287 *
288 * \sa send_standard_callback_request(), send_callback_request().
289 */
290 int send_option_arg_callback_request(struct osl_object *options,
291 int argc, char * const * const argv, callback_function *f,
292 callback_result_handler *result_handler,
293 void *private_result_data)
294 {
295 char *p;
296 int i, ret;
297 struct osl_object query = {.size = options? options->size : 0};
298
299 for (i = 0; i < argc; i++)
300 query.size += strlen(argv[i]) + 1;
301 query.data = para_malloc(query.size);
302 p = query.data;
303 if (options) {
304 memcpy(query.data, options->data, options->size);
305 p += options->size;
306 }
307 for (i = 0; i < argc; i++) {
308 strcpy(p, argv[i]); /* OK */
309 p += strlen(argv[i]) + 1;
310 }
311 ret = send_callback_request(f, &query, result_handler,
312 private_result_data);
313 free(query.data);
314 return ret;
315 }
316
317 /**
318 * Send a callback request with an argument vector only.
319 *
320 * \param argc The same meaning as in send_option_arg_callback_request().
321 * \param argv The same meaning as in send_option_arg_callback_request().
322 * \param f The same meaning as in send_option_arg_callback_request().
323 * \param result_handler See \ref send_callback_request.
324 * \param private_result_data See \ref send_callback_request.
325 *
326 * This is similar to send_option_arg_callback_request(), but no options buffer
327 * is passed to the parent process.
328 *
329 * \return The return value of the underlying call to
330 * send_option_arg_callback_request().
331 */
332 int send_standard_callback_request(int argc, char * const * const argv,
333 callback_function *f, callback_result_handler *result_handler,
334 void *private_result_data)
335 {
336 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
337 private_result_data);
338 }
339
340 static int action_if_pattern_matches(struct osl_row *row, void *data)
341 {
342 struct pattern_match_data *pmd = data;
343 struct osl_object name_obj;
344 const char *p, *name;
345 int ret = osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj);
346 const char *pattern_txt = (const char *)pmd->patterns.data;
347
348 if (ret < 0)
349 return ret;
350 name = (char *)name_obj.data;
351 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
352 return 1;
353 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
354 return pmd->action(pmd->table, row, name, pmd->data);
355 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
356 p += strlen(p) + 1) {
357 ret = fnmatch(p, name, pmd->fnmatch_flags);
358 if (ret == FNM_NOMATCH)
359 continue;
360 if (ret)
361 return -E_FNMATCH;
362 return pmd->action(pmd->table, row, name, pmd->data);
363 }
364 return 1;
365 }
366
367 /**
368 * Execute the given function for each matching row.
369 *
370 * \param pmd Describes what to match and how.
371 *
372 * \return The return value of the underlying call to osl_rbtree_loop()
373 * or osl_rbtree_loop_reverse().
374 */
375 int for_each_matching_row(struct pattern_match_data *pmd)
376 {
377 if (pmd->pm_flags & PM_REVERSE_LOOP)
378 return osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
379 action_if_pattern_matches);
380 return osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
381 action_if_pattern_matches);
382 }
383
384 /**
385 * Compare two osl objects of string type.
386 *
387 * \param obj1 Pointer to the first object.
388 * \param obj2 Pointer to the second object.
389 *
390 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
391 * are taken into account.
392 *
393 * \return It returns an integer less than, equal to, or greater than zero if
394 * \a obj1 is found, respectively, to be less than, to match, or be greater than
395 * obj2.
396 *
397 * \sa strcmp(3), strncmp(3), osl_compare_func.
398 */
399 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
400 {
401 const char *str1 = (const char *)obj1->data;
402 const char *str2 = (const char *)obj2->data;
403 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
404 }
405
406 /*
407 * write input from fd to dynamically allocated buffer,
408 * but maximal max_size byte.
409 */
410 static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
411 {
412 const size_t chunk_size = 1024;
413 size_t size = 2048, received = 0;
414 int ret;
415 char *buf = para_malloc(size);
416
417 for (;;) {
418 ret = recv_bin_buffer(fd, buf + received, chunk_size);
419 if (ret <= 0)
420 break;
421 received += ret;
422 if (received + chunk_size >= size) {
423 size *= 2;
424 ret = -E_INPUT_TOO_LARGE;
425 if (size > max_size)
426 break;
427 buf = para_realloc(buf, size);
428 }
429 }
430 obj->data = buf;
431 obj->size = received;
432 if (ret < 0)
433 free(buf);
434 return ret;
435 }
436
437 /**
438 * Read data from a file descriptor, and send it to the afs process.
439 *
440 * \param fd File descriptor to read data from.
441 * \param arg_obj Pointer to the arguments to \a f.
442 * \param f The callback function.
443 * \param max_len Don't read more than that many bytes from stdin.
444 * \param result_handler See \ref send_callback_request.
445 * \param private_result_data See \ref send_callback_request.
446 *
447 * This function is used by commands that wish to let para_server store
448 * arbitrary data specified by the user (for instance the add_blob family of
449 * commands). First, at most \a max_len bytes are read from \a fd, the result
450 * is concatenated with the buffer given by \a arg_obj, and the combined buffer
451 * is made available to the afs process via the callback method. See \ref
452 * send_callback_request for details.
453 *
454 * \return Negative on errors, the return value of the underlying call to
455 * send_callback_request() otherwise.
456 */
457 int stdin_command(int fd, struct osl_object *arg_obj, callback_function *f,
458 unsigned max_len, callback_result_handler *result_handler,
459 void *private_result_data)
460 {
461 struct osl_object query, stdin_obj;
462 int ret;
463
464 ret = send_buffer(fd, AWAITING_DATA_MSG);
465 if (ret < 0)
466 return ret;
467 ret = fd2buf(fd, max_len, &stdin_obj);
468 if (ret < 0)
469 return ret;
470 query.size = arg_obj->size + stdin_obj.size;
471 query.data = para_malloc(query.size);
472 memcpy(query.data, arg_obj->data, arg_obj->size);
473 memcpy((char *)query.data + arg_obj->size, stdin_obj.data, stdin_obj.size);
474 free(stdin_obj.data);
475 ret = send_callback_request(f, &query, result_handler, private_result_data);
476 free(query.data);
477 return ret;
478 }
479
480 static int pass_afd(int fd, char *buf, size_t size)
481 {
482 struct msghdr msg = {.msg_iov = NULL};
483 struct cmsghdr *cmsg;
484 char control[255];
485 int ret;
486 struct iovec iov;
487
488 iov.iov_base = buf;
489 iov.iov_len = size;
490
491 msg.msg_iov = &iov;
492 msg.msg_iovlen = 1;
493
494 msg.msg_control = control;
495 msg.msg_controllen = sizeof(control);
496
497 cmsg = CMSG_FIRSTHDR(&msg);
498 cmsg->cmsg_level = SOL_SOCKET;
499 cmsg->cmsg_type = SCM_RIGHTS;
500 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
501 *(int *)CMSG_DATA(cmsg) = fd;
502
503 /* Sum of the length of all control messages in the buffer */
504 msg.msg_controllen = cmsg->cmsg_len;
505 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
506 ret = sendmsg(server_socket, &msg, 0);
507 if (ret < 0) {
508 ret = -ERRNO_TO_PARA_ERROR(errno);
509 return ret;
510 }
511 return 1;
512 }
513
514 /**
515 * Open the audio file with highest score.
516 *
517 * This stores all information for streaming the "best" audio file in a shared
518 * memory area. The id of that area and an open file descriptor for the next
519 * audio file are passed to the server process.
520 *
521 * \return Standard.
522 *
523 * \sa open_and_update_audio_file().
524 */
525 static int open_next_audio_file(void)
526 {
527 struct osl_row *aft_row;
528 struct audio_file_data afd;
529 int ret, shmid;
530 char buf[8];
531 long score;
532 again:
533 PARA_NOTICE_LOG("getting next audio file\n");
534 ret = score_get_best(&aft_row, &score);
535 if (ret < 0) {
536 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
537 goto no_admissible_files;
538 }
539 ret = open_and_update_audio_file(aft_row, score, &afd);
540 if (ret < 0) {
541 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
542 ret = score_delete(aft_row);
543 if (ret < 0) {
544 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
545 goto no_admissible_files;
546 }
547 goto again;
548 }
549 shmid = ret;
550 if (!write_ok(server_socket)) {
551 ret = -E_AFS_SOCKET;
552 goto destroy;
553 }
554 *(uint32_t *)buf = NEXT_AUDIO_FILE;
555 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
556 ret = pass_afd(afd.fd, buf, 8);
557 close(afd.fd);
558 if (ret >= 0)
559 return ret;
560 destroy:
561 shm_destroy(shmid);
562 return ret;
563 no_admissible_files:
564 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
565 *(uint32_t *)(buf + 4) = (uint32_t)0;
566 return send_bin_buffer(server_socket, buf, 8);
567 }
568
569 /* Never fails if arg == NULL */
570 static int activate_mood_or_playlist(char *arg, int *num_admissible)
571 {
572 enum play_mode mode;
573 int ret;
574
575 if (!arg) {
576 ret = change_current_mood(NULL); /* always successful */
577 mode = PLAY_MODE_MOOD;
578 } else {
579 if (!strncmp(arg, "p/", 2)) {
580 ret = playlist_open(arg + 2);
581 mode = PLAY_MODE_PLAYLIST;
582 } else if (!strncmp(arg, "m/", 2)) {
583 ret = change_current_mood(arg + 2);
584 mode = PLAY_MODE_MOOD;
585 } else
586 return -E_AFS_SYNTAX;
587 if (ret < 0)
588 return ret;
589 }
590 if (num_admissible)
591 *num_admissible = ret;
592 current_play_mode = mode;
593 if (arg != current_mop) {
594 free(current_mop);
595 if (arg) {
596 current_mop = para_strdup(arg);
597 mutex_lock(mmd_mutex);
598 strncpy(mmd->afs_mode_string, arg,
599 sizeof(mmd->afs_mode_string));
600 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
601 mutex_unlock(mmd_mutex);
602 } else {
603 mutex_lock(mmd_mutex);
604 strcpy(mmd->afs_mode_string, "dummy");
605 mutex_unlock(mmd_mutex);
606 current_mop = NULL;
607 }
608 }
609 return 1;
610 }
611
612 static void com_select_callback(int fd, const struct osl_object *query)
613 {
614 struct para_buffer pb = {
615 .max_size = SHMMAX,
616 .private_data = &fd,
617 .max_size_handler = pass_buffer_as_shm
618 };
619 char *arg = query->data;
620 int num_admissible, ret, ret2;
621
622 ret = clear_score_table();
623 if (ret < 0) {
624 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
625 goto out;
626 }
627 if (current_play_mode == PLAY_MODE_MOOD)
628 close_current_mood();
629 else
630 playlist_close();
631 ret = activate_mood_or_playlist(arg, &num_admissible);
632 if (ret < 0) {
633 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
634 para_strerror(-ret), current_mop?
635 current_mop : "dummy");
636 ret = activate_mood_or_playlist(current_mop, &num_admissible);
637 if (ret < 0) {
638 if (ret2 >= 0)
639 ret2 = para_printf(&pb, "failed, switching to dummy\n");
640 activate_mood_or_playlist(NULL, &num_admissible);
641 }
642 } else
643 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
644 current_mop : "dummy mood", num_admissible);
645 out:
646 if (ret2 >= 0 && pb.offset)
647 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
648 free(pb.buf);
649 }
650
651 /**
652 * Result handler for sending data to the para_client process.
653 *
654 * \param result The data to be sent.
655 * \param fd_ptr Pointer to the file descriptor.
656 *
657 * \return The return value of the underlying call to send_bin_buffer().
658 *
659 * \sa \ref callback_result_handler.
660 */
661 int send_result(struct osl_object *result, void *fd_ptr)
662 {
663 int fd = *(int *)fd_ptr;
664 if (!result->size)
665 return 1;
666 return send_bin_buffer(fd, result->data, result->size);
667 }
668
669 int com_select(int fd, int argc, char * const * const argv)
670 {
671 struct osl_object query;
672
673 if (argc != 2)
674 return -E_AFS_SYNTAX;
675 query.data = argv[1];
676 query.size = strlen(argv[1]) + 1;
677 return send_callback_request(com_select_callback, &query,
678 &send_result, &fd);
679 }
680
681 static void init_admissible_files(char *arg)
682 {
683 if (activate_mood_or_playlist(arg, NULL) < 0)
684 activate_mood_or_playlist(NULL, NULL); /* always successful */
685 }
686
687 static int setup_command_socket_or_die(void)
688 {
689 int ret, socket_fd;
690 char *socket_name = conf.afs_socket_arg;
691 struct sockaddr_un unix_addr;
692
693 unlink(socket_name);
694 ret = create_local_socket(socket_name, &unix_addr,
695 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
696 if (ret < 0) {
697 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
698 exit(EXIT_FAILURE);
699 }
700 socket_fd = ret;
701 if (listen(socket_fd , 5) < 0) {
702 PARA_EMERG_LOG("can not listen on socket\n");
703 exit(EXIT_FAILURE);
704 }
705 ret = mark_fd_nonblocking(socket_fd);
706 if (ret < 0) {
707 close(socket_fd);
708 return ret;
709 }
710 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
711 socket_fd);
712 return socket_fd;
713 }
714
715 static void close_afs_tables(void)
716 {
717 int i;
718 PARA_NOTICE_LOG("closing afs_tables\n");
719 for (i = 0; i < NUM_AFS_TABLES; i++)
720 afs_tables[i].close();
721 }
722
723 static char *database_dir;
724
725 static void get_database_dir(void)
726 {
727 if (!database_dir) {
728 if (conf.afs_database_dir_given)
729 database_dir = para_strdup(conf.afs_database_dir_arg);
730 else {
731 char *home = para_homedir();
732 database_dir = make_message(
733 "%s/.paraslash/afs_database", home);
734 free(home);
735 }
736 }
737 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
738 }
739
740 static int make_database_dir(void)
741 {
742 int ret;
743
744 get_database_dir();
745 ret = para_mkdir(database_dir, 0777);
746 if (ret >= 0 || is_errno(-ret, EEXIST))
747 return 1;
748 return ret;
749 }
750
751 static int open_afs_tables(void)
752 {
753 int i, ret;
754
755 get_database_dir();
756 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
757 database_dir);
758 for (i = 0; i < NUM_AFS_TABLES; i++) {
759 ret = afs_tables[i].open(database_dir);
760 if (ret >= 0)
761 continue;
762 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
763 para_strerror(-ret));
764 break;
765 }
766 if (ret >= 0)
767 return ret;
768 while (i)
769 afs_tables[--i].close();
770 return ret;
771 }
772
773 static void signal_pre_select(struct sched *s, struct task *t)
774 {
775 struct signal_task *st = container_of(t, struct signal_task, task);
776 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
777 }
778
779 static void signal_post_select(struct sched *s, struct task *t)
780 {
781 struct signal_task *st = container_of(t, struct signal_task, task);
782 if (getppid() == 1) {
783 PARA_EMERG_LOG("para_server died\n");
784 goto shutdown;
785 }
786 if (!FD_ISSET(st->fd, &s->rfds))
787 return;
788 st->signum = para_next_signal();
789 if (st->signum == SIGHUP) {
790 close_afs_tables();
791 parse_config_or_die(1);
792 t->error = open_afs_tables();
793 if (t->error < 0)
794 return;
795 init_admissible_files(current_mop);
796 return;
797 }
798 PARA_EMERG_LOG("terminating on signal %d\n", st->signum);
799 shutdown:
800 sched_shutdown();
801 t->error = -E_AFS_SIGNAL;
802 }
803
804 static void register_signal_task(void)
805 {
806 struct signal_task *st = &signal_task_struct;
807
808 para_sigaction(SIGPIPE, SIG_IGN);
809 st->fd = para_signal_init();
810 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
811 para_install_sighandler(SIGINT);
812 para_install_sighandler(SIGTERM);
813 para_install_sighandler(SIGHUP);
814
815 st->task.pre_select = signal_pre_select;
816 st->task.post_select = signal_post_select;
817 sprintf(st->task.status, "signal task");
818 register_task(&st->task);
819 }
820
821 static struct list_head afs_client_list;
822
823 /** Describes on connected afs client. */
824 struct afs_client {
825 /** Position in the afs client list. */
826 struct list_head node;
827 /** The socket file descriptor for this client. */
828 int fd;
829 /** The time the client connected. */
830 struct timeval connect_time;
831 };
832
833 static void command_pre_select(struct sched *s, struct task *t)
834 {
835 struct command_task *ct = container_of(t, struct command_task, task);
836 struct afs_client *client;
837
838 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
839 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
840 list_for_each_entry(client, &afs_client_list, node)
841 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
842 }
843
844 /**
845 * Send data as shared memory to a file descriptor.
846 *
847 * \param buf The buffer holding the data to be sent.
848 * \param size The size of \a buf.
849 * \param fd_ptr A pointer to the file descriptor.
850 *
851 * This function is used as the \a max_size handler in a \ref para_buffer
852 * structure. If used this way, it is called by \ref para_printf() whenever
853 * the buffer passed to para_printf() is about to exceed its maximal size.
854 *
855 * This function creates a shared memory area large enough to hold
856 * the content given by \a buf and \a size and sends the identifier
857 * of this area to the file descriptor given by \a fd_ptr.
858 *
859 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
860 * and positive on success.
861 */
862 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
863 {
864 int ret, shmid, fd = *(int *)fd_ptr;
865 void *shm;
866 struct callback_result *cr;
867
868 if (!buf || !size)
869 return 0;
870 ret = shm_new(size + sizeof(struct callback_result));
871 if (ret < 0)
872 return ret;
873 shmid = ret;
874 ret = shm_attach(shmid, ATTACH_RW, &shm);
875 if (ret < 0)
876 goto err;
877 cr = shm;
878 cr->result_size = size;
879 memcpy(shm + sizeof(*cr), buf, size);
880 ret = shm_detach(shm);
881 if (ret < 0)
882 goto err;
883 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
884 if (ret >= 0)
885 return ret;
886 err:
887 if (shm_destroy(shmid) < 0)
888 PARA_ERROR_LOG("destroy result failed\n");
889 return ret;
890 }
891
892 /*
893 * On errors, negative value is written to fd.
894 * On success: If query produced a result, the result_shmid is written to fd.
895 * Otherwise, zero is written.
896 */
897 static int call_callback(int fd, int query_shmid)
898 {
899 void *query_shm;
900 struct callback_query *cq;
901 struct osl_object query;
902 int ret;
903
904 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
905 if (ret < 0)
906 return ret;
907 cq = query_shm;
908 query.data = (char *)query_shm + sizeof(*cq);
909 query.size = cq->query_size;
910 cq->handler(fd, &query);
911 return shm_detach(query_shm);
912 }
913
914 static int execute_server_command(void)
915 {
916 char buf[8];
917 int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
918
919 if (ret <= 0) {
920 if (!ret)
921 ret = -ERRNO_TO_PARA_ERROR(ECONNRESET);
922 goto err;
923 }
924 buf[ret] = '\0';
925 PARA_DEBUG_LOG("received: %s\n", buf);
926 ret = -E_BAD_CMD;
927 if (strcmp(buf, "new"))
928 goto err;
929 ret = open_next_audio_file();
930 err:
931 return ret;
932 }
933
934 static void execute_afs_command(int fd, uint32_t expected_cookie)
935 {
936 uint32_t cookie;
937 int query_shmid;
938 char buf[sizeof(cookie) + sizeof(query_shmid)];
939 int ret = recv_bin_buffer(fd, buf, sizeof(buf));
940
941 if (ret < 0)
942 goto err;
943 if (ret != sizeof(buf)) {
944 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
945 ret, (long unsigned) sizeof(buf));
946 return;
947 }
948 cookie = *(uint32_t *)buf;
949 if (cookie != expected_cookie) {
950 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
951 (unsigned)cookie, (unsigned)expected_cookie);
952 return;
953 }
954 query_shmid = *(int *)(buf + sizeof(cookie));
955 if (query_shmid < 0) {
956 PARA_WARNING_LOG("received invalid query shmid %d)\n",
957 query_shmid);
958 return;
959 }
960 ret = call_callback(fd, query_shmid);
961 if (ret >= 0)
962 return;
963 err:
964 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
965 }
966
967 /** Shutdown connection if query has not arrived until this many seconds. */
968 #define AFS_CLIENT_TIMEOUT 3
969
970 static void command_post_select(struct sched *s, struct task *t)
971 {
972 struct command_task *ct = container_of(t, struct command_task, task);
973 struct sockaddr_un unix_addr;
974 struct afs_client *client, *tmp;
975 int fd, ret;
976
977 if (FD_ISSET(server_socket, &s->rfds)) {
978 ret = execute_server_command();
979 if (ret < 0) {
980 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
981 sched_shutdown();
982 return;
983 }
984 }
985
986 /* Check the list of connected clients. */
987 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
988 if (FD_ISSET(client->fd, &s->rfds))
989 execute_afs_command(client->fd, ct->cookie);
990 else { /* prevent bogus connection flooding */
991 struct timeval diff;
992 tv_diff(now, &client->connect_time, &diff);
993 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
994 continue;
995 PARA_WARNING_LOG("connection timeout\n");
996 }
997 close(client->fd);
998 list_del(&client->node);
999 free(client);
1000 }
1001 /* Accept connections on the local socket. */
1002 if (!FD_ISSET(ct->fd, &s->rfds))
1003 return;
1004 ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
1005 if (ret < 0) {
1006 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1007 return;
1008 }
1009 fd = ret;
1010 ret = mark_fd_nonblocking(fd);
1011 if (ret < 0) {
1012 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1013 close(fd);
1014 return;
1015 }
1016 client = para_malloc(sizeof(*client));
1017 client->fd = fd;
1018 client->connect_time = *now;
1019 para_list_add(&client->node, &afs_client_list);
1020 }
1021
1022 static void register_command_task(uint32_t cookie)
1023 {
1024 struct command_task *ct = &command_task_struct;
1025 ct->fd = setup_command_socket_or_die();
1026 ct->cookie = cookie;
1027
1028 ct->task.pre_select = command_pre_select;
1029 ct->task.post_select = command_post_select;
1030 sprintf(ct->task.status, "command task");
1031 register_task(&ct->task);
1032 }
1033
1034 /**
1035 * Initialize the audio file selector process.
1036 *
1037 * \param cookie The value used for "authentication".
1038 * \param socket_fd File descriptor used for communication with the server.
1039 */
1040 __noreturn void afs_init(uint32_t cookie, int socket_fd)
1041 {
1042 static struct sched s;
1043 int i, ret;
1044
1045 register_signal_task();
1046 INIT_LIST_HEAD(&afs_client_list);
1047 for (i = 0; i < NUM_AFS_TABLES; i++)
1048 afs_tables[i].init(&afs_tables[i]);
1049 ret = open_afs_tables();
1050 if (ret < 0)
1051 goto out;
1052 server_socket = socket_fd;
1053 ret = mark_fd_nonblocking(server_socket);
1054 if (ret < 0)
1055 goto out_close;
1056 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1057 server_socket, (unsigned) cookie);
1058 init_admissible_files(conf.afs_initial_mode_arg);
1059 register_command_task(cookie);
1060 s.default_timeout.tv_sec = 0;
1061 s.default_timeout.tv_usec = 999 * 1000;
1062 ret = schedule(&s);
1063 out_close:
1064 close_afs_tables();
1065 out:
1066 if (ret < 0)
1067 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1068 exit(EXIT_FAILURE);
1069 }
1070
1071 static void create_tables_callback(int fd, const struct osl_object *query)
1072 {
1073 uint32_t table_mask = *(uint32_t *)query->data;
1074 int i, ret;
1075 char *buf;
1076
1077 close_afs_tables();
1078 for (i = 0; i < NUM_AFS_TABLES; i++) {
1079 struct afs_table *t = &afs_tables[i];
1080
1081 if (!(table_mask & (1 << i)))
1082 continue;
1083 if (!t->create)
1084 continue;
1085 ret = t->create(database_dir);
1086 if (ret < 0)
1087 goto out;
1088 }
1089 ret = open_afs_tables();
1090 out:
1091 if (ret >= 0)
1092 buf = make_message("successfully created afs table(s)\n");
1093 else
1094 buf = make_message("%s\n", para_strerror(-ret));
1095 pass_buffer_as_shm(buf, strlen(buf), &fd);
1096 free(buf);
1097 }
1098
1099 int com_init(int fd, int argc, char * const * const argv)
1100 {
1101 int i, j, ret;
1102 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1103 struct osl_object query = {.data = &table_mask,
1104 .size = sizeof(table_mask)};
1105
1106 ret = make_database_dir();
1107 if (ret < 0)
1108 return ret;
1109 if (argc != 1) {
1110 table_mask = 0;
1111 for (i = 1; i < argc; i++) {
1112 for (j = 0; j < NUM_AFS_TABLES; j++) {
1113 struct afs_table *t = &afs_tables[j];
1114
1115 if (strcmp(argv[i], t->name))
1116 continue;
1117 table_mask |= (1 << j);
1118 break;
1119 }
1120 if (j == NUM_AFS_TABLES)
1121 return -E_BAD_TABLE_NAME;
1122 }
1123 }
1124 ret = send_callback_request(create_tables_callback, &query, &send_result, &fd);
1125 if (ret < 0)
1126 return send_va_buffer(fd, "%s\n", para_strerror(-ret));
1127 return ret;
1128 }
1129
1130 /**
1131 * Flags for the check command.
1132 *
1133 * \sa com_check().
1134 */
1135 enum com_check_flags {
1136 /** Check the audio file table. */
1137 CHECK_AFT = 1,
1138 /** Check the mood table. */
1139 CHECK_MOODS = 2,
1140 /** Check the playlist table. */
1141 CHECK_PLAYLISTS = 4
1142 };
1143
1144 int com_check(int fd, int argc, char * const * const argv)
1145 {
1146 unsigned flags = 0;
1147 int i, ret;
1148
1149 for (i = 1; i < argc; i++) {
1150 const char *arg = argv[i];
1151 if (arg[0] != '-')
1152 break;
1153 if (!strcmp(arg, "--")) {
1154 i++;
1155 break;
1156 }
1157 if (!strcmp(arg, "-a")) {
1158 flags |= CHECK_AFT;
1159 continue;
1160 }
1161 if (!strcmp(arg, "-p")) {
1162 flags |= CHECK_PLAYLISTS;
1163 continue;
1164 }
1165 if (!strcmp(arg, "-m")) {
1166 flags |= CHECK_MOODS;
1167 continue;
1168 }
1169 return -E_AFS_SYNTAX;
1170 }
1171 if (i < argc)
1172 return -E_AFS_SYNTAX;
1173 if (!flags)
1174 flags = ~0U;
1175 if (flags & CHECK_AFT) {
1176 ret = send_callback_request(aft_check_callback, NULL, send_result, &fd);
1177 if (ret < 0)
1178 return ret;
1179 }
1180 if (flags & CHECK_PLAYLISTS) {
1181 ret = send_callback_request(playlist_check_callback, NULL, send_result, &fd);
1182 if (ret < 0)
1183 return ret;
1184 }
1185 if (flags & CHECK_MOODS) {
1186 ret = send_callback_request(mood_check_callback, NULL, send_result, &fd);
1187 if (ret < 0)
1188 return ret;
1189 }
1190 return 1;
1191 }
1192
1193 /**
1194 * The afs event dispatcher.
1195 *
1196 * \param event Type of the event.
1197 * \param pb May be \p NULL.
1198 * \param data Type depends on \a event.
1199 *
1200 * This function calls the table handlers of all tables and passes \a pb and \a
1201 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1202 */
1203 void afs_event(enum afs_events event, struct para_buffer *pb,
1204 void *data)
1205 {
1206 int i, ret;
1207
1208 for (i = 0; i < NUM_AFS_TABLES; i++) {
1209 struct afs_table *t = &afs_tables[i];
1210 if (!t->event_handler)
1211 continue;
1212 ret = t->event_handler(event, pb, data);
1213 if (ret < 0)
1214 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1215 event, para_strerror(-ret));
1216 }
1217 }
1218
1219 int images_event_handler(__a_unused enum afs_events event,
1220 __a_unused struct para_buffer *pb, __a_unused void *data)
1221 {
1222 return 1;
1223 }
1224
1225 int lyrics_event_handler(__a_unused enum afs_events event,
1226 __a_unused struct para_buffer *pb, __a_unused void *data)
1227 {
1228 return 1;
1229 }