afs.c: Get rid of unregister_tasks().
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2008 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 struct misc_meta_data *mmd;
79
80 static int server_socket;
81 static struct command_task command_task_struct;
82 static struct signal_task signal_task_struct;
83
84 static enum play_mode current_play_mode;
85 static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
86
87
88 /**
89 * A random number used to "authenticate" the connection.
90 *
91 * para_server picks this number by random before forking the afs process. The
92 * command handlers write this number together with the id of the shared memory
93 * area containing the query. This way, a malicious local user has to know this
94 * number to be able to cause the afs process to crash by sending fake queries.
95 */
96 extern uint32_t afs_socket_cookie;
97
98 /**
99 * Struct to let command handlers execute a callback in afs context.
100 *
101 * Commands that need to change the state of afs can't change the relevant data
102 * structures directly because commands are executed in a child process, i.e.
103 * they get their own virtual address space.
104 *
105 * This structure is used by \p send_callback_request() (executed from handler
106 * context) in order to let the afs process call the specified function. An
107 * instance of that structure is written to a shared memory area together with
108 * the arguments to the callback function. The identifier of the shared memory
109 * area is written to the command socket.
110 *
111 * The afs process accepts connections on the command socket and reads the
112 * shared memory id, attaches the corresponing area, calls the given handler to
113 * perform the desired action and to optionally compute a result.
114 *
115 * The result and a \p callback_result structure is then written to another
116 * shared memory area. The identifier for that area is written to the handler's
117 * command socket, so that the handler process can read the id, attach the
118 * shared memory area and use the result.
119 *
120 * \sa struct callback_result.
121 */
122 struct callback_query {
123 /** The function to be called. */
124 callback_function *handler;
125 /** The number of bytes of the query */
126 size_t query_size;
127 };
128
129 /**
130 * Structure embedded in the result of a callback.
131 *
132 * If the callback produced a result, an instance of that structure is embeeded
133 * into the shared memory area holding the result, mainly to let the command
134 * handler know the size of the result.
135 *
136 * \sa struct callback_query.
137 */
138 struct callback_result {
139 /** The number of bytes of the result. */
140 size_t result_size;
141 };
142
143 /**
144 * Ask the afs process to call a given function.
145 *
146 * \param f The function to be called.
147 * \param query Pointer to arbitrary data for the callback.
148 * \param result_handler Called for each shm area sent by the callback.
149 * \param private_result_data Passed verbatim to \a result_handler.
150 *
151 * This function creates a socket for communication with the afs process and a
152 * shared memory area (sma) to which the buffer pointed to by \a query is
153 * copied. It then notifies the afs process that the callback function \a f
154 * should be executed by sending the shared memory identifier (shmid) to the
155 * socket.
156
157 * If the callback produces a result, it sends any number of shared memory
158 * identifiers back via the socket. For each such identifier received, \a
159 * result_handler is called. The contents of the sma identified by the received
160 * shmid are passed to that function as an osl object. The private_result_data
161 * pointer is passed as the second argument to \a result_handler.
162 *
163 * \return Negative, on errors, the return value of the callback function
164 * otherwise.
165 *
166 * \sa send_option_arg_callback_request(), send_standard_callback_request().
167 */
168 int send_callback_request(callback_function *f, struct osl_object *query,
169 callback_result_handler *result_handler,
170 void *private_result_data)
171 {
172 struct callback_query *cq;
173 int num_results = 0, ret, fd = -1, query_shmid, result_shmid;
174 void *query_shm, *result_shm;
175 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
176 size_t query_shm_size = sizeof(*cq);
177
178 if (query)
179 query_shm_size += query->size;
180 ret = shm_new(query_shm_size);
181 if (ret < 0)
182 return ret;
183 query_shmid = ret;
184 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
185 if (ret < 0)
186 goto out;
187 cq = query_shm;
188 cq->handler = f;
189 cq->query_size = query_shm_size - sizeof(*cq);
190
191 if (query)
192 memcpy(query_shm + sizeof(*cq), query->data, query->size);
193 ret = shm_detach(query_shm);
194 if (ret < 0)
195 goto out;
196
197 *(uint32_t *) buf = afs_socket_cookie;
198 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
199
200 ret = create_remote_socket(conf.afs_socket_arg);
201 if (ret < 0)
202 goto out;
203 fd = ret;
204 ret = send_bin_buffer(fd, buf, sizeof(buf));
205 if (ret < 0)
206 goto out;
207 for (;;) {
208 ret = recv_bin_buffer(fd, buf, sizeof(int));
209 if (ret <= 0)
210 goto out;
211 if (ret != sizeof(int)) {
212 ret = -E_AFS_SHORT_READ;
213 goto out;
214 }
215 ret = *(int *) buf;
216 if (ret <= 0)
217 goto out;
218 result_shmid = ret;
219 ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
220 if (ret >= 0) {
221 struct callback_result *cr = result_shm;
222 struct osl_object result;
223 num_results++;
224 result.size = cr->result_size;
225 result.data = result_shm + sizeof(*cr);
226 if (result.size) {
227 assert(result_handler);
228 ret = result_handler(&result, private_result_data);
229 if (shm_detach(result_shm) < 0)
230 PARA_ERROR_LOG("can not detach result\n");
231 }
232 } else
233 PARA_ERROR_LOG("attach result failed: %d\n", ret);
234 if (shm_destroy(result_shmid) < 0)
235 PARA_ERROR_LOG("destroy result failed\n");
236 if (ret < 0)
237 break;
238 }
239 out:
240 if (shm_destroy(query_shmid) < 0)
241 PARA_ERROR_LOG("%s\n", "shm destroy error");
242 if (fd >= 0)
243 close(fd);
244 if (ret >= 0)
245 ret = num_results;
246 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
247 return ret;
248 }
249
250 /**
251 * Send a callback request passing an options structure and an argument vector.
252 *
253 * \param options pointer to an arbitrary data structure.
254 * \param argc Argument count.
255 * \param argv Standard argument vector.
256 * \param f The callback function.
257 * \param result_handler See \ref send_callback_request.
258 * \param private_result_data See \ref send_callback_request.
259 *
260 * Some commands have a couple of options that are parsed in child context for
261 * syntactic correctness and are stored in a special options structure for that
262 * command. This function allows to pass such a structure together with a list
263 * of further arguments (often a list of audio files) to the parent process.
264 *
265 * \sa send_standard_callback_request(), send_callback_request().
266 */
267 int send_option_arg_callback_request(struct osl_object *options,
268 int argc, char * const * const argv, callback_function *f,
269 callback_result_handler *result_handler,
270 void *private_result_data)
271 {
272 char *p;
273 int i, ret;
274 struct osl_object query = {.size = options? options->size : 0};
275
276 for (i = 0; i < argc; i++)
277 query.size += strlen(argv[i]) + 1;
278 query.data = para_malloc(query.size);
279 p = query.data;
280 if (options) {
281 memcpy(query.data, options->data, options->size);
282 p += options->size;
283 }
284 for (i = 0; i < argc; i++) {
285 strcpy(p, argv[i]); /* OK */
286 p += strlen(argv[i]) + 1;
287 }
288 ret = send_callback_request(f, &query, result_handler,
289 private_result_data);
290 free(query.data);
291 return ret;
292 }
293
294 /**
295 * Send a callback request with an argument vector only.
296 *
297 * \param argc The same meaning as in send_option_arg_callback_request().
298 * \param argv The same meaning as in send_option_arg_callback_request().
299 * \param f The same meaning as in send_option_arg_callback_request().
300 * \param result_handler See \ref send_callback_request.
301 * \param private_result_data See \ref send_callback_request.
302 *
303 * This is similar to send_option_arg_callback_request(), but no options buffer
304 * is passed to the parent process.
305 *
306 * \return The return value of the underlying call to
307 * send_option_arg_callback_request().
308 */
309 int send_standard_callback_request(int argc, char * const * const argv,
310 callback_function *f, callback_result_handler *result_handler,
311 void *private_result_data)
312 {
313 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
314 private_result_data);
315 }
316
317 static int action_if_pattern_matches(struct osl_row *row, void *data)
318 {
319 struct pattern_match_data *pmd = data;
320 struct osl_object name_obj;
321 const char *p, *name;
322 int ret = osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj);
323 const char *pattern_txt = (const char *)pmd->patterns.data;
324
325 if (ret < 0)
326 return ret;
327 name = (char *)name_obj.data;
328 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
329 return 1;
330 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
331 return pmd->action(pmd->table, row, name, pmd->data);
332 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
333 p += strlen(p) + 1) {
334 ret = fnmatch(p, name, pmd->fnmatch_flags);
335 if (ret == FNM_NOMATCH)
336 continue;
337 if (ret)
338 return -E_FNMATCH;
339 return pmd->action(pmd->table, row, name, pmd->data);
340 }
341 return 1;
342 }
343
344 /**
345 * Execute the given function for each matching row.
346 *
347 * \param pmd Describes what to match and how.
348 *
349 * \return The return value of the underlying call to osl_rbtree_loop()
350 * or osl_rbtree_loop_reverse().
351 */
352 int for_each_matching_row(struct pattern_match_data *pmd)
353 {
354 if (pmd->pm_flags & PM_REVERSE_LOOP)
355 return osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
356 action_if_pattern_matches);
357 return osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
358 action_if_pattern_matches);
359 }
360
361 /**
362 * Compare two osl objects of string type.
363 *
364 * \param obj1 Pointer to the first object.
365 * \param obj2 Pointer to the second object.
366 *
367 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
368 * are taken into account.
369 *
370 * \return It returns an integer less than, equal to, or greater than zero if
371 * \a obj1 is found, respectively, to be less than, to match, or be greater than
372 * obj2.
373 *
374 * \sa strcmp(3), strncmp(3), osl_compare_func.
375 */
376 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
377 {
378 const char *str1 = (const char *)obj1->data;
379 const char *str2 = (const char *)obj2->data;
380 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
381 }
382
383 /*
384 * write input from fd to dynamically allocated buffer,
385 * but maximal max_size byte.
386 */
387 static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
388 {
389 const size_t chunk_size = 1024;
390 size_t size = 2048, received = 0;
391 int ret;
392 char *buf = para_malloc(size);
393
394 for (;;) {
395 ret = recv_bin_buffer(fd, buf + received, chunk_size);
396 if (ret <= 0)
397 break;
398 received += ret;
399 if (received + chunk_size >= size) {
400 size *= 2;
401 ret = -E_INPUT_TOO_LARGE;
402 if (size > max_size)
403 break;
404 buf = para_realloc(buf, size);
405 }
406 }
407 obj->data = buf;
408 obj->size = received;
409 if (ret < 0)
410 free(buf);
411 return ret;
412 }
413
414 /**
415 * Read data from a file descriptor, and send it to the afs process.
416 *
417 * \param fd File descriptor to read data from.
418 * \param arg_obj Pointer to the arguments to \a f.
419 * \param f The callback function.
420 * \param max_len Don't read more than that many bytes from stdin.
421 * \param result_handler See \ref send_callback_request.
422 * \param private_result_data See \ref send_callback_request.
423 *
424 * This function is used by commands that wish to let para_server store
425 * arbitrary data specified by the user (for instance the add_blob family of
426 * commands). First, at most \a max_len bytes are read from \a fd, the result
427 * is concatenated with the buffer given by \a arg_obj, and the combined buffer
428 * is made available to the afs process via the callback method. See \ref
429 * send_callback_request for details.
430 *
431 * \return Negative on errors, the return value of the underlying call to
432 * send_callback_request() otherwise.
433 */
434 int stdin_command(int fd, struct osl_object *arg_obj, callback_function *f,
435 unsigned max_len, callback_result_handler *result_handler,
436 void *private_result_data)
437 {
438 struct osl_object query, stdin_obj;
439 int ret;
440
441 ret = send_buffer(fd, AWAITING_DATA_MSG);
442 if (ret < 0)
443 return ret;
444 ret = fd2buf(fd, max_len, &stdin_obj);
445 if (ret < 0)
446 return ret;
447 query.size = arg_obj->size + stdin_obj.size;
448 query.data = para_malloc(query.size);
449 memcpy(query.data, arg_obj->data, arg_obj->size);
450 memcpy((char *)query.data + arg_obj->size, stdin_obj.data, stdin_obj.size);
451 free(stdin_obj.data);
452 ret = send_callback_request(f, &query, result_handler, private_result_data);
453 free(query.data);
454 return ret;
455 }
456
457 static int pass_afd(int fd, char *buf, size_t size)
458 {
459 struct msghdr msg = {.msg_iov = NULL};
460 struct cmsghdr *cmsg;
461 char control[255];
462 int ret;
463 struct iovec iov;
464
465 iov.iov_base = buf;
466 iov.iov_len = size;
467
468 msg.msg_iov = &iov;
469 msg.msg_iovlen = 1;
470
471 msg.msg_control = control;
472 msg.msg_controllen = sizeof(control);
473
474 cmsg = CMSG_FIRSTHDR(&msg);
475 cmsg->cmsg_level = SOL_SOCKET;
476 cmsg->cmsg_type = SCM_RIGHTS;
477 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
478 *(int *)CMSG_DATA(cmsg) = fd;
479
480 /* Sum of the length of all control messages in the buffer */
481 msg.msg_controllen = cmsg->cmsg_len;
482 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
483 ret = sendmsg(server_socket, &msg, 0);
484 if (ret < 0) {
485 ret = -ERRNO_TO_PARA_ERROR(errno);
486 return ret;
487 }
488 return 1;
489 }
490
491 /**
492 * Open the audio file with highest score.
493 *
494 * This stores all information for streaming the "best" audio file in a shared
495 * memory area. The id of that area and an open file descriptor for the next
496 * audio file are passed to the server process.
497 *
498 * \return Standard.
499 *
500 * \sa open_and_update_audio_file().
501 */
502 int open_next_audio_file(void)
503 {
504 struct osl_row *aft_row;
505 struct audio_file_data afd;
506 int ret, shmid;
507 char buf[8];
508 long score;
509 again:
510 PARA_NOTICE_LOG("getting next audio file\n");
511 ret = score_get_best(&aft_row, &score);
512 if (ret < 0) {
513 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
514 goto no_admissible_files;
515 }
516 ret = open_and_update_audio_file(aft_row, score, &afd);
517 if (ret < 0) {
518 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
519 ret = score_delete(aft_row);
520 if (ret < 0) {
521 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
522 goto no_admissible_files;
523 }
524 goto again;
525 }
526 shmid = ret;
527 if (!write_ok(server_socket)) {
528 ret = -E_AFS_SOCKET;
529 goto destroy;
530 }
531 *(uint32_t *)buf = NEXT_AUDIO_FILE;
532 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
533 ret = pass_afd(afd.fd, buf, 8);
534 close(afd.fd);
535 if (ret >= 0)
536 return ret;
537 destroy:
538 shm_destroy(shmid);
539 return ret;
540 no_admissible_files:
541 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
542 *(uint32_t *)(buf + 4) = (uint32_t)0;
543 return send_bin_buffer(server_socket, buf, 8);
544 }
545
546 /* Never fails if arg == NULL */
547 static int activate_mood_or_playlist(char *arg, int *num_admissible)
548 {
549 enum play_mode mode;
550 int ret;
551
552 if (!arg) {
553 ret = change_current_mood(NULL); /* always successful */
554 mode = PLAY_MODE_MOOD;
555 } else {
556 if (!strncmp(arg, "p/", 2)) {
557 ret = playlist_open(arg + 2);
558 mode = PLAY_MODE_PLAYLIST;
559 } else if (!strncmp(arg, "m/", 2)) {
560 ret = change_current_mood(arg + 2);
561 mode = PLAY_MODE_MOOD;
562 } else
563 return -E_AFS_SYNTAX;
564 if (ret < 0)
565 return ret;
566 }
567 if (num_admissible)
568 *num_admissible = ret;
569 current_play_mode = mode;
570 if (arg != current_mop) {
571 free(current_mop);
572 if (arg) {
573 current_mop = para_strdup(arg);
574 mmd_lock();
575 strncpy(mmd->afs_mode_string, arg,
576 sizeof(mmd->afs_mode_string));
577 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
578 mmd_unlock();
579 } else {
580 mmd_lock();
581 strcpy(mmd->afs_mode_string, "dummy");
582 mmd_unlock();
583 current_mop = NULL;
584 }
585 }
586 return 1;
587 }
588
589 static void com_select_callback(int fd, const struct osl_object *query)
590 {
591 struct para_buffer pb = {
592 .max_size = SHMMAX,
593 .private_data = &fd,
594 .max_size_handler = pass_buffer_as_shm
595 };
596 char *arg = query->data;
597 int num_admissible, ret, ret2;
598
599 ret = clear_score_table();
600 if (ret < 0) {
601 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
602 goto out;
603 }
604 if (current_play_mode == PLAY_MODE_MOOD)
605 close_current_mood();
606 else
607 playlist_close();
608 ret = activate_mood_or_playlist(arg, &num_admissible);
609 if (ret < 0) {
610 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
611 para_strerror(-ret), current_mop?
612 current_mop : "dummy");
613 ret = activate_mood_or_playlist(current_mop, &num_admissible);
614 if (ret < 0) {
615 if (ret2 >= 0)
616 ret2 = para_printf(&pb, "failed, switching to dummy\n");
617 activate_mood_or_playlist(NULL, &num_admissible);
618 }
619 } else
620 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
621 current_mop : "dummy mood", num_admissible);
622 out:
623 if (ret2 >= 0 && pb.offset)
624 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
625 free(pb.buf);
626 }
627
628 /**
629 * Result handler for sending data to the para_client process.
630 *
631 * \param result The data to be sent.
632 * \param fd_ptr Pointer to the file descriptor.
633 *
634 * \return The return value of the underlying call to send_bin_buffer().
635 *
636 * \sa \ref callback_result_handler.
637 */
638 int send_result(struct osl_object *result, void *fd_ptr)
639 {
640 int fd = *(int *)fd_ptr;
641 if (!result->size)
642 return 1;
643 return send_bin_buffer(fd, result->data, result->size);
644 }
645
646 int com_select(int fd, int argc, char * const * const argv)
647 {
648 struct osl_object query;
649
650 if (argc != 2)
651 return -E_AFS_SYNTAX;
652 query.data = argv[1];
653 query.size = strlen(argv[1]) + 1;
654 return send_callback_request(com_select_callback, &query,
655 &send_result, &fd);
656 }
657
658 static void init_admissible_files(char *arg)
659 {
660 if (activate_mood_or_playlist(arg, NULL) < 0)
661 activate_mood_or_playlist(NULL, NULL); /* always successful */
662 }
663
664 static int setup_command_socket_or_die(void)
665 {
666 int ret, socket_fd;
667 char *socket_name = conf.afs_socket_arg;
668 struct sockaddr_un unix_addr;
669
670 unlink(socket_name);
671 ret = create_local_socket(socket_name, &unix_addr,
672 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
673 if (ret < 0) {
674 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
675 exit(EXIT_FAILURE);
676 }
677 socket_fd = ret;
678 if (listen(socket_fd , 5) < 0) {
679 PARA_EMERG_LOG("can not listen on socket\n");
680 exit(EXIT_FAILURE);
681 }
682 ret = mark_fd_nonblocking(socket_fd);
683 if (ret < 0) {
684 close(socket_fd);
685 return ret;
686 }
687 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
688 socket_fd);
689 return socket_fd;
690 }
691
692 static void close_afs_tables(void)
693 {
694 int i;
695 PARA_NOTICE_LOG("closing afs_tables\n");
696 for (i = 0; i < NUM_AFS_TABLES; i++)
697 afs_tables[i].close();
698 }
699
700 static char *database_dir;
701
702 static void get_database_dir(void)
703 {
704 if (!database_dir) {
705 if (conf.afs_database_dir_given)
706 database_dir = para_strdup(conf.afs_database_dir_arg);
707 else {
708 char *home = para_homedir();
709 database_dir = make_message(
710 "%s/.paraslash/afs_database", home);
711 free(home);
712 }
713 }
714 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
715 }
716
717 static int make_database_dir(void)
718 {
719 int ret;
720
721 get_database_dir();
722 ret = para_mkdir(database_dir, 0777);
723 if (ret >= 0 || is_errno(-ret, EEXIST))
724 return 1;
725 return ret;
726 }
727
728 static int open_afs_tables(void)
729 {
730 int i, ret;
731
732 get_database_dir();
733 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
734 database_dir);
735 for (i = 0; i < NUM_AFS_TABLES; i++) {
736 ret = afs_tables[i].open(database_dir);
737 if (ret >= 0)
738 continue;
739 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
740 para_strerror(-ret));
741 break;
742 }
743 if (ret >= 0)
744 return ret;
745 while (i)
746 afs_tables[--i].close();
747 return ret;
748 }
749
750 static void signal_pre_select(struct sched *s, struct task *t)
751 {
752 struct signal_task *st = container_of(t, struct signal_task, task);
753 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
754 }
755
756 static void signal_post_select(struct sched *s, struct task *t)
757 {
758 struct signal_task *st = container_of(t, struct signal_task, task);
759 if (getppid() == 1) {
760 t->error = -E_AFS_PARENT_DIED;
761 return;
762 }
763 if (!FD_ISSET(st->fd, &s->rfds))
764 return;
765 st->signum = para_next_signal();
766 if (st->signum == SIGHUP) {
767 close_afs_tables();
768 t->error = open_afs_tables();
769 if (t->error < 0)
770 return;
771 init_admissible_files(current_mop);
772 return;
773 }
774 sched_shutdown();
775 t->error = -E_AFS_SIGNAL;
776 }
777
778 static void register_signal_task(void)
779 {
780 struct signal_task *st = &signal_task_struct;
781
782 if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
783 PARA_EMERG_LOG("failed to ignore SIGPIPE\n");
784 exit(EXIT_FAILURE);
785 }
786 if (signal(SIGUSR1, SIG_IGN) == SIG_ERR) {
787 PARA_EMERG_LOG("failed to ignore SIGUSR1\n");
788 exit(EXIT_FAILURE);
789 }
790 st->fd = para_signal_init();
791 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
792 para_install_sighandler(SIGINT);
793 para_install_sighandler(SIGTERM);
794 para_install_sighandler(SIGHUP);
795
796 st->task.pre_select = signal_pre_select;
797 st->task.post_select = signal_post_select;
798 sprintf(st->task.status, "signal task");
799 register_task(&st->task);
800 }
801
802 static struct list_head afs_client_list;
803
804 /** Describes on connected afs client. */
805 struct afs_client {
806 /** Position in the afs client list. */
807 struct list_head node;
808 /** The socket file descriptor for this client. */
809 int fd;
810 /** The time the client connected. */
811 struct timeval connect_time;
812 };
813
814 static void command_pre_select(struct sched *s, struct task *t)
815 {
816 struct command_task *ct = container_of(t, struct command_task, task);
817 struct afs_client *client;
818
819 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
820 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
821 list_for_each_entry(client, &afs_client_list, node)
822 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
823 }
824
825 /**
826 * Send data as shared memory to a file descriptor.
827 *
828 * \param buf The buffer holding the data to be sent.
829 * \param size The size of \a buf.
830 * \param fd_ptr A pointer to the file descriptor.
831 *
832 * This function is used as the \a max_size handler in a \ref para_buffer
833 * structure. If used this way, it is called by \ref para_printf() whenever
834 * the buffer passed to para_printf() is about to exceed its maximal size.
835 *
836 * This function creates a shared memory area large enough to hold
837 * the content given by \a buf and \a size and sends the identifier
838 * of this area to the file descriptor given by \a fd_ptr.
839 *
840 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
841 * and positive on success.
842 */
843 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
844 {
845 int ret, shmid, fd = *(int *)fd_ptr;
846 void *shm;
847 struct callback_result *cr;
848
849 if (!buf || !size)
850 return 0;
851 ret = shm_new(size + sizeof(struct callback_result));
852 if (ret < 0)
853 return ret;
854 shmid = ret;
855 ret = shm_attach(shmid, ATTACH_RW, &shm);
856 if (ret < 0)
857 goto err;
858 cr = shm;
859 cr->result_size = size;
860 memcpy(shm + sizeof(*cr), buf, size);
861 ret = shm_detach(shm);
862 if (ret < 0)
863 goto err;
864 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
865 if (ret >= 0)
866 return ret;
867 err:
868 if (shm_destroy(shmid) < 0)
869 PARA_ERROR_LOG("destroy result failed\n");
870 return ret;
871 }
872
873 /*
874 * On errors, negative value is written to fd.
875 * On success: If query produced a result, the result_shmid is written to fd.
876 * Otherwise, zero is written.
877 */
878 static int call_callback(int fd, int query_shmid)
879 {
880 void *query_shm;
881 struct callback_query *cq;
882 struct osl_object query;
883 int ret;
884
885 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
886 if (ret < 0)
887 return ret;
888 cq = query_shm;
889 query.data = (char *)query_shm + sizeof(*cq);
890 query.size = cq->query_size;
891 cq->handler(fd, &query);
892 return 1;
893 }
894
895 static int execute_server_command(void)
896 {
897 char buf[8];
898 int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
899
900 if (ret <= 0) {
901 if (!ret)
902 ret = -ERRNO_TO_PARA_ERROR(ECONNRESET);
903 goto err;
904 }
905 buf[ret] = '\0';
906 PARA_DEBUG_LOG("received: %s\n", buf);
907 ret = -E_BAD_CMD;
908 if (strcmp(buf, "new"))
909 goto err;
910 ret = open_next_audio_file();
911 err:
912 return ret;
913 }
914
915 static void execute_afs_command(int fd, uint32_t expected_cookie)
916 {
917 uint32_t cookie;
918 int query_shmid;
919 char buf[sizeof(cookie) + sizeof(query_shmid)];
920 int ret = recv_bin_buffer(fd, buf, sizeof(buf));
921
922 if (ret < 0)
923 goto err;
924 if (ret != sizeof(buf)) {
925 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
926 ret, (long unsigned) sizeof(buf));
927 return;
928 }
929 cookie = *(uint32_t *)buf;
930 if (cookie != expected_cookie) {
931 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
932 (unsigned)cookie, (unsigned)expected_cookie);
933 return;
934 }
935 query_shmid = *(int *)(buf + sizeof(cookie));
936 if (query_shmid < 0) {
937 PARA_WARNING_LOG("received invalid query shmid %d)\n",
938 query_shmid);
939 return;
940 }
941 ret = call_callback(fd, query_shmid);
942 if (ret >= 0)
943 return;
944 err:
945 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
946 }
947
948 /** Shutdown connection if query has not arrived until this many seconds. */
949 #define AFS_CLIENT_TIMEOUT 3
950
951 static void command_post_select(struct sched *s, struct task *t)
952 {
953 struct command_task *ct = container_of(t, struct command_task, task);
954 struct sockaddr_un unix_addr;
955 struct afs_client *client, *tmp;
956 int fd, ret;
957
958 if (FD_ISSET(server_socket, &s->rfds)) {
959 ret = execute_server_command();
960 if (ret < 0) {
961 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
962 sched_shutdown();
963 return;
964 }
965 }
966
967 /* Check the list of connected clients. */
968 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
969 if (FD_ISSET(client->fd, &s->rfds))
970 execute_afs_command(client->fd, ct->cookie);
971 else { /* prevent bogus connection flooding */
972 struct timeval diff;
973 tv_diff(now, &client->connect_time, &diff);
974 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
975 continue;
976 PARA_WARNING_LOG("connection timeout\n");
977 }
978 close(client->fd);
979 list_del(&client->node);
980 free(client);
981 }
982 /* Accept connections on the local socket. */
983 if (!FD_ISSET(ct->fd, &s->rfds))
984 return;
985 ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
986 if (ret < 0) {
987 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
988 return;
989 }
990 fd = ret;
991 ret = mark_fd_nonblocking(fd);
992 if (ret < 0) {
993 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
994 close(fd);
995 return;
996 }
997 client = para_malloc(sizeof(*client));
998 client->fd = fd;
999 client->connect_time = *now;
1000 para_list_add(&client->node, &afs_client_list);
1001 }
1002
1003 static void register_command_task(uint32_t cookie)
1004 {
1005 struct command_task *ct = &command_task_struct;
1006 ct->fd = setup_command_socket_or_die();
1007 ct->cookie = cookie;
1008
1009 ct->task.pre_select = command_pre_select;
1010 ct->task.post_select = command_post_select;
1011 sprintf(ct->task.status, "command task");
1012 register_task(&ct->task);
1013 }
1014
1015 /**
1016 * Initialize the audio file selector process.
1017 *
1018 * \param cookie The value used for "authentication".
1019 * \param socket_fd File descriptor used for communication with the server.
1020 */
1021 __noreturn void afs_init(uint32_t cookie, int socket_fd)
1022 {
1023 struct sched s;
1024 int i, ret;
1025
1026 register_signal_task();
1027 INIT_LIST_HEAD(&afs_client_list);
1028 for (i = 0; i < NUM_AFS_TABLES; i++)
1029 afs_tables[i].init(&afs_tables[i]);
1030 ret = open_afs_tables();
1031 if (ret < 0)
1032 goto out;
1033 server_socket = socket_fd;
1034 ret = mark_fd_nonblocking(server_socket);
1035 if (ret < 0)
1036 goto out_close;
1037 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1038 server_socket, (unsigned) cookie);
1039 init_admissible_files(conf.afs_initial_mode_arg);
1040 register_command_task(cookie);
1041 s.default_timeout.tv_sec = 0;
1042 s.default_timeout.tv_usec = 999 * 1000;
1043 ret = schedule(&s);
1044 out_close:
1045 close_afs_tables();
1046 out:
1047 if (ret < 0)
1048 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1049 exit(EXIT_FAILURE);
1050 }
1051
1052 static void create_tables_callback(int fd, const struct osl_object *query)
1053 {
1054 uint32_t table_mask = *(uint32_t *)query->data;
1055 int i, ret;
1056 char *buf;
1057
1058 close_afs_tables();
1059 for (i = 0; i < NUM_AFS_TABLES; i++) {
1060 struct afs_table *t = &afs_tables[i];
1061
1062 if (!(table_mask & (1 << i)))
1063 continue;
1064 if (!t->create)
1065 continue;
1066 ret = t->create(database_dir);
1067 if (ret < 0)
1068 goto out;
1069 }
1070 ret = open_afs_tables();
1071 out:
1072 if (ret >= 0)
1073 buf = make_message("successfully created afs table(s)\n");
1074 else
1075 buf = make_message("%s\n", para_strerror(-ret));
1076 pass_buffer_as_shm(buf, strlen(buf), &fd);
1077 free(buf);
1078 }
1079
1080 int com_init(int fd, int argc, char * const * const argv)
1081 {
1082 int i, j, ret;
1083 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1084 struct osl_object query = {.data = &table_mask,
1085 .size = sizeof(table_mask)};
1086
1087 ret = make_database_dir();
1088 if (ret < 0)
1089 return ret;
1090 if (argc != 1) {
1091 table_mask = 0;
1092 for (i = 1; i < argc; i++) {
1093 for (j = 0; j < NUM_AFS_TABLES; j++) {
1094 struct afs_table *t = &afs_tables[j];
1095
1096 if (strcmp(argv[i], t->name))
1097 continue;
1098 table_mask |= (1 << j);
1099 break;
1100 }
1101 if (j == NUM_AFS_TABLES)
1102 return -E_BAD_TABLE_NAME;
1103 }
1104 }
1105 ret = send_callback_request(create_tables_callback, &query, NULL, NULL);
1106 if (ret < 0)
1107 return send_va_buffer(fd, "%s\n", para_strerror(-ret));
1108 return ret;
1109 }
1110
1111 /**
1112 * Flags for the check command.
1113 *
1114 * \sa com_check().
1115 */
1116 enum com_check_flags {
1117 /** Check the audio file table. */
1118 CHECK_AFT = 1,
1119 /** Check the mood table. */
1120 CHECK_MOODS = 2,
1121 /** Check the playlist table. */
1122 CHECK_PLAYLISTS = 4
1123 };
1124
1125 int com_check(int fd, int argc, char * const * const argv)
1126 {
1127 unsigned flags = 0;
1128 int i, ret;
1129
1130 for (i = 1; i < argc; i++) {
1131 const char *arg = argv[i];
1132 if (arg[0] != '-')
1133 break;
1134 if (!strcmp(arg, "--")) {
1135 i++;
1136 break;
1137 }
1138 if (!strcmp(arg, "-a")) {
1139 flags |= CHECK_AFT;
1140 continue;
1141 }
1142 if (!strcmp(arg, "-p")) {
1143 flags |= CHECK_PLAYLISTS;
1144 continue;
1145 }
1146 if (!strcmp(arg, "-m")) {
1147 flags |= CHECK_MOODS;
1148 continue;
1149 }
1150 return -E_AFS_SYNTAX;
1151 }
1152 if (i < argc)
1153 return -E_AFS_SYNTAX;
1154 if (!flags)
1155 flags = ~0U;
1156 if (flags & CHECK_AFT) {
1157 ret = send_callback_request(aft_check_callback, NULL, send_result, &fd);
1158 if (ret < 0)
1159 return ret;
1160 }
1161 if (flags & CHECK_PLAYLISTS) {
1162 ret = send_callback_request(playlist_check_callback, NULL, send_result, &fd);
1163 if (ret < 0)
1164 return ret;
1165 }
1166 if (flags & CHECK_MOODS) {
1167 ret = send_callback_request(mood_check_callback, NULL, send_result, &fd);
1168 if (ret < 0)
1169 return ret;
1170 }
1171 return 1;
1172 }
1173
1174 void afs_event(enum afs_events event, struct para_buffer *pb,
1175 void *data)
1176 {
1177 int i, ret;
1178
1179 for (i = 0; i < NUM_AFS_TABLES; i++) {
1180 struct afs_table *t = &afs_tables[i];
1181 if (!t->event_handler)
1182 continue;
1183 ret = t->event_handler(event, pb, data);
1184 if (ret < 0)
1185 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1186 }
1187 }
1188
1189 int images_event_handler(__a_unused enum afs_events event,
1190 __a_unused struct para_buffer *pb, __a_unused void *data)
1191 {
1192 return 1;
1193 }
1194
1195 int lyrics_event_handler(__a_unused enum afs_events event,
1196 __a_unused struct para_buffer *pb, __a_unused void *data)
1197 {
1198 return 1;
1199 }