server.c: Add some more Doxygen links.
[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 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 /**
145 * Ask the afs process to call a given function.
146 *
147 * \param f The function to be called.
148 * \param query Pointer to arbitrary data for the callback.
149 * \param result_handler Called for each shm area sent by the callback.
150 * \param private_result_data Passed verbatim to \a result_handler.
151 *
152 * This function creates a socket for communication with the afs process and a
153 * shared memory area (sma) to which the buffer pointed to by \a query is
154 * copied. It then notifies the afs process that the callback function \a f
155 * should be executed by sending the shared memory identifier (shmid) to the
156 * socket.
157
158 * If the callback produces a result, it sends any number of shared memory
159 * identifiers back via the socket. For each such identifier received, \a
160 * result_handler is called. The contents of the sma identified by the received
161 * shmid are passed to that function as an osl object. The private_result_data
162 * pointer is passed as the second argument to \a result_handler.
163 *
164 * \return Negative, on errors, the return value of the callback function
165 * otherwise.
166 *
167 * \sa send_option_arg_callback_request(), send_standard_callback_request().
168 */
169 int send_callback_request(callback_function *f, struct osl_object *query,
170 callback_result_handler *result_handler,
171 void *private_result_data)
172 {
173 struct callback_query *cq;
174 int num_results = 0, ret, fd = -1, query_shmid, result_shmid;
175 void *query_shm, *result_shm;
176 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
177 size_t query_shm_size = sizeof(*cq);
178
179 if (query)
180 query_shm_size += query->size;
181 ret = shm_new(query_shm_size);
182 if (ret < 0)
183 return ret;
184 query_shmid = ret;
185 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
186 if (ret < 0)
187 goto out;
188 cq = query_shm;
189 cq->handler = f;
190 cq->query_size = query_shm_size - sizeof(*cq);
191
192 if (query)
193 memcpy(query_shm + sizeof(*cq), query->data, query->size);
194 ret = shm_detach(query_shm);
195 if (ret < 0)
196 goto out;
197
198 *(uint32_t *) buf = afs_socket_cookie;
199 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
200
201 ret = create_remote_socket(conf.afs_socket_arg);
202 if (ret < 0)
203 goto out;
204 fd = ret;
205 ret = send_bin_buffer(fd, buf, sizeof(buf));
206 if (ret < 0)
207 goto out;
208 for (;;) {
209 ret = recv_bin_buffer(fd, buf, sizeof(int));
210 if (ret <= 0)
211 goto out;
212 if (ret != sizeof(int)) {
213 ret = -E_AFS_SHORT_READ;
214 goto out;
215 }
216 ret = *(int *) buf;
217 if (ret <= 0)
218 goto out;
219 result_shmid = ret;
220 ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
221 if (ret >= 0) {
222 struct callback_result *cr = result_shm;
223 struct osl_object result;
224 num_results++;
225 result.size = cr->result_size;
226 result.data = result_shm + sizeof(*cr);
227 if (result.size) {
228 assert(result_handler);
229 ret = result_handler(&result, private_result_data);
230 if (shm_detach(result_shm) < 0)
231 PARA_ERROR_LOG("can not detach result\n");
232 }
233 } else
234 PARA_ERROR_LOG("attach result failed: %d\n", ret);
235 if (shm_destroy(result_shmid) < 0)
236 PARA_ERROR_LOG("destroy result failed\n");
237 if (ret < 0)
238 break;
239 }
240 out:
241 if (shm_destroy(query_shmid) < 0)
242 PARA_ERROR_LOG("%s\n", "shm destroy error");
243 if (fd >= 0)
244 close(fd);
245 if (ret >= 0)
246 ret = num_results;
247 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
248 return ret;
249 }
250
251 /**
252 * Send a callback request passing an options structure and an argument vector.
253 *
254 * \param options pointer to an arbitrary data structure.
255 * \param argc Argument count.
256 * \param argv Standard argument vector.
257 * \param f The callback function.
258 * \param result_handler See \ref send_callback_request.
259 * \param private_result_data See \ref send_callback_request.
260 *
261 * Some commands have a couple of options that are parsed in child context for
262 * syntactic correctness and are stored in a special options structure for that
263 * command. This function allows to pass such a structure together with a list
264 * of further arguments (often a list of audio files) to the parent process.
265 *
266 * \sa send_standard_callback_request(), send_callback_request().
267 */
268 int send_option_arg_callback_request(struct osl_object *options,
269 int argc, char * const * const argv, callback_function *f,
270 callback_result_handler *result_handler,
271 void *private_result_data)
272 {
273 char *p;
274 int i, ret;
275 struct osl_object query = {.size = options? options->size : 0};
276
277 for (i = 0; i < argc; i++)
278 query.size += strlen(argv[i]) + 1;
279 query.data = para_malloc(query.size);
280 p = query.data;
281 if (options) {
282 memcpy(query.data, options->data, options->size);
283 p += options->size;
284 }
285 for (i = 0; i < argc; i++) {
286 strcpy(p, argv[i]); /* OK */
287 p += strlen(argv[i]) + 1;
288 }
289 ret = send_callback_request(f, &query, result_handler,
290 private_result_data);
291 free(query.data);
292 return ret;
293 }
294
295 /**
296 * Send a callback request with an argument vector only.
297 *
298 * \param argc The same meaning as in send_option_arg_callback_request().
299 * \param argv The same meaning as in send_option_arg_callback_request().
300 * \param f The same meaning as in send_option_arg_callback_request().
301 * \param result_handler See \ref send_callback_request.
302 * \param private_result_data See \ref send_callback_request.
303 *
304 * This is similar to send_option_arg_callback_request(), but no options buffer
305 * is passed to the parent process.
306 *
307 * \return The return value of the underlying call to
308 * send_option_arg_callback_request().
309 */
310 int send_standard_callback_request(int argc, char * const * const argv,
311 callback_function *f, callback_result_handler *result_handler,
312 void *private_result_data)
313 {
314 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
315 private_result_data);
316 }
317
318 static int action_if_pattern_matches(struct osl_row *row, void *data)
319 {
320 struct pattern_match_data *pmd = data;
321 struct osl_object name_obj;
322 const char *p, *name;
323 int ret = osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj);
324 const char *pattern_txt = (const char *)pmd->patterns.data;
325
326 if (ret < 0)
327 return ret;
328 name = (char *)name_obj.data;
329 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
330 return 1;
331 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
332 return pmd->action(pmd->table, row, name, pmd->data);
333 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
334 p += strlen(p) + 1) {
335 ret = fnmatch(p, name, pmd->fnmatch_flags);
336 if (ret == FNM_NOMATCH)
337 continue;
338 if (ret)
339 return -E_FNMATCH;
340 return pmd->action(pmd->table, row, name, pmd->data);
341 }
342 return 1;
343 }
344
345 /**
346 * Execute the given function for each matching row.
347 *
348 * \param pmd Describes what to match and how.
349 *
350 * \return The return value of the underlying call to osl_rbtree_loop()
351 * or osl_rbtree_loop_reverse().
352 */
353 int for_each_matching_row(struct pattern_match_data *pmd)
354 {
355 if (pmd->pm_flags & PM_REVERSE_LOOP)
356 return osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
357 action_if_pattern_matches);
358 return osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
359 action_if_pattern_matches);
360 }
361
362 /**
363 * Compare two osl objects of string type.
364 *
365 * \param obj1 Pointer to the first object.
366 * \param obj2 Pointer to the second object.
367 *
368 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
369 * are taken into account.
370 *
371 * \return It returns an integer less than, equal to, or greater than zero if
372 * \a obj1 is found, respectively, to be less than, to match, or be greater than
373 * obj2.
374 *
375 * \sa strcmp(3), strncmp(3), osl_compare_func.
376 */
377 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
378 {
379 const char *str1 = (const char *)obj1->data;
380 const char *str2 = (const char *)obj2->data;
381 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
382 }
383
384 /*
385 * write input from fd to dynamically allocated buffer,
386 * but maximal max_size byte.
387 */
388 static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
389 {
390 const size_t chunk_size = 1024;
391 size_t size = 2048, received = 0;
392 int ret;
393 char *buf = para_malloc(size);
394
395 for (;;) {
396 ret = recv_bin_buffer(fd, buf + received, chunk_size);
397 if (ret <= 0)
398 break;
399 received += ret;
400 if (received + chunk_size >= size) {
401 size *= 2;
402 ret = -E_INPUT_TOO_LARGE;
403 if (size > max_size)
404 break;
405 buf = para_realloc(buf, size);
406 }
407 }
408 obj->data = buf;
409 obj->size = received;
410 if (ret < 0)
411 free(buf);
412 return ret;
413 }
414
415 /**
416 * Read data from a file descriptor, and send it to the afs process.
417 *
418 * \param fd File descriptor to read data from.
419 * \param arg_obj Pointer to the arguments to \a f.
420 * \param f The callback function.
421 * \param max_len Don't read more than that many bytes from stdin.
422 * \param result_handler See \ref send_callback_request.
423 * \param private_result_data See \ref send_callback_request.
424 *
425 * This function is used by commands that wish to let para_server store
426 * arbitrary data specified by the user (for instance the add_blob family of
427 * commands). First, at most \a max_len bytes are read from \a fd, the result
428 * is concatenated with the buffer given by \a arg_obj, and the combined buffer
429 * is made available to the afs process via the callback method. See \ref
430 * send_callback_request for details.
431 *
432 * \return Negative on errors, the return value of the underlying call to
433 * send_callback_request() otherwise.
434 */
435 int stdin_command(int fd, struct osl_object *arg_obj, callback_function *f,
436 unsigned max_len, callback_result_handler *result_handler,
437 void *private_result_data)
438 {
439 struct osl_object query, stdin_obj;
440 int ret;
441
442 ret = send_buffer(fd, AWAITING_DATA_MSG);
443 if (ret < 0)
444 return ret;
445 ret = fd2buf(fd, max_len, &stdin_obj);
446 if (ret < 0)
447 return ret;
448 query.size = arg_obj->size + stdin_obj.size;
449 query.data = para_malloc(query.size);
450 memcpy(query.data, arg_obj->data, arg_obj->size);
451 memcpy((char *)query.data + arg_obj->size, stdin_obj.data, stdin_obj.size);
452 free(stdin_obj.data);
453 ret = send_callback_request(f, &query, result_handler, private_result_data);
454 free(query.data);
455 return ret;
456 }
457
458 static int pass_afd(int fd, char *buf, size_t size)
459 {
460 struct msghdr msg = {.msg_iov = NULL};
461 struct cmsghdr *cmsg;
462 char control[255];
463 int ret;
464 struct iovec iov;
465
466 iov.iov_base = buf;
467 iov.iov_len = size;
468
469 msg.msg_iov = &iov;
470 msg.msg_iovlen = 1;
471
472 msg.msg_control = control;
473 msg.msg_controllen = sizeof(control);
474
475 cmsg = CMSG_FIRSTHDR(&msg);
476 cmsg->cmsg_level = SOL_SOCKET;
477 cmsg->cmsg_type = SCM_RIGHTS;
478 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
479 *(int *)CMSG_DATA(cmsg) = fd;
480
481 /* Sum of the length of all control messages in the buffer */
482 msg.msg_controllen = cmsg->cmsg_len;
483 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
484 ret = sendmsg(server_socket, &msg, 0);
485 if (ret < 0) {
486 ret = -ERRNO_TO_PARA_ERROR(errno);
487 return ret;
488 }
489 return 1;
490 }
491
492 /**
493 * Open the audio file with highest score.
494 *
495 * This stores all information for streaming the "best" audio file in a shared
496 * memory area. The id of that area and an open file descriptor for the next
497 * audio file are passed to the server process.
498 *
499 * \return Standard.
500 *
501 * \sa open_and_update_audio_file().
502 */
503 static int open_next_audio_file(void)
504 {
505 struct osl_row *aft_row;
506 struct audio_file_data afd;
507 int ret, shmid;
508 char buf[8];
509 long score;
510 again:
511 PARA_NOTICE_LOG("getting next audio file\n");
512 ret = score_get_best(&aft_row, &score);
513 if (ret < 0) {
514 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
515 goto no_admissible_files;
516 }
517 ret = open_and_update_audio_file(aft_row, score, &afd);
518 if (ret < 0) {
519 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
520 ret = score_delete(aft_row);
521 if (ret < 0) {
522 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
523 goto no_admissible_files;
524 }
525 goto again;
526 }
527 shmid = ret;
528 if (!write_ok(server_socket)) {
529 ret = -E_AFS_SOCKET;
530 goto destroy;
531 }
532 *(uint32_t *)buf = NEXT_AUDIO_FILE;
533 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
534 ret = pass_afd(afd.fd, buf, 8);
535 close(afd.fd);
536 if (ret >= 0)
537 return ret;
538 destroy:
539 shm_destroy(shmid);
540 return ret;
541 no_admissible_files:
542 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
543 *(uint32_t *)(buf + 4) = (uint32_t)0;
544 return send_bin_buffer(server_socket, buf, 8);
545 }
546
547 /* Never fails if arg == NULL */
548 static int activate_mood_or_playlist(char *arg, int *num_admissible)
549 {
550 enum play_mode mode;
551 int ret;
552
553 if (!arg) {
554 ret = change_current_mood(NULL); /* always successful */
555 mode = PLAY_MODE_MOOD;
556 } else {
557 if (!strncmp(arg, "p/", 2)) {
558 ret = playlist_open(arg + 2);
559 mode = PLAY_MODE_PLAYLIST;
560 } else if (!strncmp(arg, "m/", 2)) {
561 ret = change_current_mood(arg + 2);
562 mode = PLAY_MODE_MOOD;
563 } else
564 return -E_AFS_SYNTAX;
565 if (ret < 0)
566 return ret;
567 }
568 if (num_admissible)
569 *num_admissible = ret;
570 current_play_mode = mode;
571 if (arg != current_mop) {
572 free(current_mop);
573 if (arg) {
574 current_mop = para_strdup(arg);
575 mutex_lock(mmd_mutex);
576 strncpy(mmd->afs_mode_string, arg,
577 sizeof(mmd->afs_mode_string));
578 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
579 mutex_unlock(mmd_mutex);
580 } else {
581 mutex_lock(mmd_mutex);
582 strcpy(mmd->afs_mode_string, "dummy");
583 mutex_unlock(mmd_mutex);
584 current_mop = NULL;
585 }
586 }
587 return 1;
588 }
589
590 static void com_select_callback(int fd, const struct osl_object *query)
591 {
592 struct para_buffer pb = {
593 .max_size = SHMMAX,
594 .private_data = &fd,
595 .max_size_handler = pass_buffer_as_shm
596 };
597 char *arg = query->data;
598 int num_admissible, ret, ret2;
599
600 ret = clear_score_table();
601 if (ret < 0) {
602 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
603 goto out;
604 }
605 if (current_play_mode == PLAY_MODE_MOOD)
606 close_current_mood();
607 else
608 playlist_close();
609 ret = activate_mood_or_playlist(arg, &num_admissible);
610 if (ret < 0) {
611 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
612 para_strerror(-ret), current_mop?
613 current_mop : "dummy");
614 ret = activate_mood_or_playlist(current_mop, &num_admissible);
615 if (ret < 0) {
616 if (ret2 >= 0)
617 ret2 = para_printf(&pb, "failed, switching to dummy\n");
618 activate_mood_or_playlist(NULL, &num_admissible);
619 }
620 } else
621 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
622 current_mop : "dummy mood", num_admissible);
623 out:
624 if (ret2 >= 0 && pb.offset)
625 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
626 free(pb.buf);
627 }
628
629 /**
630 * Result handler for sending data to the para_client process.
631 *
632 * \param result The data to be sent.
633 * \param fd_ptr Pointer to the file descriptor.
634 *
635 * \return The return value of the underlying call to send_bin_buffer().
636 *
637 * \sa \ref callback_result_handler.
638 */
639 int send_result(struct osl_object *result, void *fd_ptr)
640 {
641 int fd = *(int *)fd_ptr;
642 if (!result->size)
643 return 1;
644 return send_bin_buffer(fd, result->data, result->size);
645 }
646
647 int com_select(int fd, int argc, char * const * const argv)
648 {
649 struct osl_object query;
650
651 if (argc != 2)
652 return -E_AFS_SYNTAX;
653 query.data = argv[1];
654 query.size = strlen(argv[1]) + 1;
655 return send_callback_request(com_select_callback, &query,
656 &send_result, &fd);
657 }
658
659 static void init_admissible_files(char *arg)
660 {
661 if (activate_mood_or_playlist(arg, NULL) < 0)
662 activate_mood_or_playlist(NULL, NULL); /* always successful */
663 }
664
665 static int setup_command_socket_or_die(void)
666 {
667 int ret, socket_fd;
668 char *socket_name = conf.afs_socket_arg;
669 struct sockaddr_un unix_addr;
670
671 unlink(socket_name);
672 ret = create_local_socket(socket_name, &unix_addr,
673 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
674 if (ret < 0) {
675 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
676 exit(EXIT_FAILURE);
677 }
678 socket_fd = ret;
679 if (listen(socket_fd , 5) < 0) {
680 PARA_EMERG_LOG("can not listen on socket\n");
681 exit(EXIT_FAILURE);
682 }
683 ret = mark_fd_nonblocking(socket_fd);
684 if (ret < 0) {
685 close(socket_fd);
686 return ret;
687 }
688 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
689 socket_fd);
690 return socket_fd;
691 }
692
693 static void close_afs_tables(void)
694 {
695 int i;
696 PARA_NOTICE_LOG("closing afs_tables\n");
697 for (i = 0; i < NUM_AFS_TABLES; i++)
698 afs_tables[i].close();
699 }
700
701 static char *database_dir;
702
703 static void get_database_dir(void)
704 {
705 if (!database_dir) {
706 if (conf.afs_database_dir_given)
707 database_dir = para_strdup(conf.afs_database_dir_arg);
708 else {
709 char *home = para_homedir();
710 database_dir = make_message(
711 "%s/.paraslash/afs_database", home);
712 free(home);
713 }
714 }
715 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
716 }
717
718 static int make_database_dir(void)
719 {
720 int ret;
721
722 get_database_dir();
723 ret = para_mkdir(database_dir, 0777);
724 if (ret >= 0 || is_errno(-ret, EEXIST))
725 return 1;
726 return ret;
727 }
728
729 static int open_afs_tables(void)
730 {
731 int i, ret;
732
733 get_database_dir();
734 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
735 database_dir);
736 for (i = 0; i < NUM_AFS_TABLES; i++) {
737 ret = afs_tables[i].open(database_dir);
738 if (ret >= 0)
739 continue;
740 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
741 para_strerror(-ret));
742 break;
743 }
744 if (ret >= 0)
745 return ret;
746 while (i)
747 afs_tables[--i].close();
748 return ret;
749 }
750
751 static void signal_pre_select(struct sched *s, struct task *t)
752 {
753 struct signal_task *st = container_of(t, struct signal_task, task);
754 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
755 }
756
757 static void signal_post_select(struct sched *s, struct task *t)
758 {
759 struct signal_task *st = container_of(t, struct signal_task, task);
760 if (getppid() == 1) {
761 PARA_EMERG_LOG("para_server died\n");
762 goto shutdown;
763 }
764 if (!FD_ISSET(st->fd, &s->rfds))
765 return;
766 st->signum = para_next_signal();
767 if (st->signum == SIGHUP) {
768 close_afs_tables();
769 t->error = open_afs_tables();
770 if (t->error < 0)
771 return;
772 init_admissible_files(current_mop);
773 return;
774 }
775 PARA_EMERG_LOG("terminating on signal %d\n", st->signum);
776 shutdown:
777 sched_shutdown();
778 t->error = -E_AFS_SIGNAL;
779 }
780
781 static void register_signal_task(void)
782 {
783 struct signal_task *st = &signal_task_struct;
784
785 if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
786 PARA_EMERG_LOG("failed to ignore SIGPIPE\n");
787 exit(EXIT_FAILURE);
788 }
789 if (signal(SIGUSR1, SIG_IGN) == SIG_ERR) {
790 PARA_EMERG_LOG("failed to ignore SIGUSR1\n");
791 exit(EXIT_FAILURE);
792 }
793 st->fd = para_signal_init();
794 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
795 para_install_sighandler(SIGINT);
796 para_install_sighandler(SIGTERM);
797 para_install_sighandler(SIGHUP);
798
799 st->task.pre_select = signal_pre_select;
800 st->task.post_select = signal_post_select;
801 sprintf(st->task.status, "signal task");
802 register_task(&st->task);
803 }
804
805 static struct list_head afs_client_list;
806
807 /** Describes on connected afs client. */
808 struct afs_client {
809 /** Position in the afs client list. */
810 struct list_head node;
811 /** The socket file descriptor for this client. */
812 int fd;
813 /** The time the client connected. */
814 struct timeval connect_time;
815 };
816
817 static void command_pre_select(struct sched *s, struct task *t)
818 {
819 struct command_task *ct = container_of(t, struct command_task, task);
820 struct afs_client *client;
821
822 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
823 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
824 list_for_each_entry(client, &afs_client_list, node)
825 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
826 }
827
828 /**
829 * Send data as shared memory to a file descriptor.
830 *
831 * \param buf The buffer holding the data to be sent.
832 * \param size The size of \a buf.
833 * \param fd_ptr A pointer to the file descriptor.
834 *
835 * This function is used as the \a max_size handler in a \ref para_buffer
836 * structure. If used this way, it is called by \ref para_printf() whenever
837 * the buffer passed to para_printf() is about to exceed its maximal size.
838 *
839 * This function creates a shared memory area large enough to hold
840 * the content given by \a buf and \a size and sends the identifier
841 * of this area to the file descriptor given by \a fd_ptr.
842 *
843 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
844 * and positive on success.
845 */
846 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
847 {
848 int ret, shmid, fd = *(int *)fd_ptr;
849 void *shm;
850 struct callback_result *cr;
851
852 if (!buf || !size)
853 return 0;
854 ret = shm_new(size + sizeof(struct callback_result));
855 if (ret < 0)
856 return ret;
857 shmid = ret;
858 ret = shm_attach(shmid, ATTACH_RW, &shm);
859 if (ret < 0)
860 goto err;
861 cr = shm;
862 cr->result_size = size;
863 memcpy(shm + sizeof(*cr), buf, size);
864 ret = shm_detach(shm);
865 if (ret < 0)
866 goto err;
867 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
868 if (ret >= 0)
869 return ret;
870 err:
871 if (shm_destroy(shmid) < 0)
872 PARA_ERROR_LOG("destroy result failed\n");
873 return ret;
874 }
875
876 /*
877 * On errors, negative value is written to fd.
878 * On success: If query produced a result, the result_shmid is written to fd.
879 * Otherwise, zero is written.
880 */
881 static int call_callback(int fd, int query_shmid)
882 {
883 void *query_shm;
884 struct callback_query *cq;
885 struct osl_object query;
886 int ret;
887
888 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
889 if (ret < 0)
890 return ret;
891 cq = query_shm;
892 query.data = (char *)query_shm + sizeof(*cq);
893 query.size = cq->query_size;
894 cq->handler(fd, &query);
895 return 1;
896 }
897
898 static int execute_server_command(void)
899 {
900 char buf[8];
901 int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
902
903 if (ret <= 0) {
904 if (!ret)
905 ret = -ERRNO_TO_PARA_ERROR(ECONNRESET);
906 goto err;
907 }
908 buf[ret] = '\0';
909 PARA_DEBUG_LOG("received: %s\n", buf);
910 ret = -E_BAD_CMD;
911 if (strcmp(buf, "new"))
912 goto err;
913 ret = open_next_audio_file();
914 err:
915 return ret;
916 }
917
918 static void execute_afs_command(int fd, uint32_t expected_cookie)
919 {
920 uint32_t cookie;
921 int query_shmid;
922 char buf[sizeof(cookie) + sizeof(query_shmid)];
923 int ret = recv_bin_buffer(fd, buf, sizeof(buf));
924
925 if (ret < 0)
926 goto err;
927 if (ret != sizeof(buf)) {
928 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
929 ret, (long unsigned) sizeof(buf));
930 return;
931 }
932 cookie = *(uint32_t *)buf;
933 if (cookie != expected_cookie) {
934 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
935 (unsigned)cookie, (unsigned)expected_cookie);
936 return;
937 }
938 query_shmid = *(int *)(buf + sizeof(cookie));
939 if (query_shmid < 0) {
940 PARA_WARNING_LOG("received invalid query shmid %d)\n",
941 query_shmid);
942 return;
943 }
944 ret = call_callback(fd, query_shmid);
945 if (ret >= 0)
946 return;
947 err:
948 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
949 }
950
951 /** Shutdown connection if query has not arrived until this many seconds. */
952 #define AFS_CLIENT_TIMEOUT 3
953
954 static void command_post_select(struct sched *s, struct task *t)
955 {
956 struct command_task *ct = container_of(t, struct command_task, task);
957 struct sockaddr_un unix_addr;
958 struct afs_client *client, *tmp;
959 int fd, ret;
960
961 if (FD_ISSET(server_socket, &s->rfds)) {
962 ret = execute_server_command();
963 if (ret < 0) {
964 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
965 sched_shutdown();
966 return;
967 }
968 }
969
970 /* Check the list of connected clients. */
971 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
972 if (FD_ISSET(client->fd, &s->rfds))
973 execute_afs_command(client->fd, ct->cookie);
974 else { /* prevent bogus connection flooding */
975 struct timeval diff;
976 tv_diff(now, &client->connect_time, &diff);
977 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
978 continue;
979 PARA_WARNING_LOG("connection timeout\n");
980 }
981 close(client->fd);
982 list_del(&client->node);
983 free(client);
984 }
985 /* Accept connections on the local socket. */
986 if (!FD_ISSET(ct->fd, &s->rfds))
987 return;
988 ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
989 if (ret < 0) {
990 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
991 return;
992 }
993 fd = ret;
994 ret = mark_fd_nonblocking(fd);
995 if (ret < 0) {
996 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
997 close(fd);
998 return;
999 }
1000 client = para_malloc(sizeof(*client));
1001 client->fd = fd;
1002 client->connect_time = *now;
1003 para_list_add(&client->node, &afs_client_list);
1004 }
1005
1006 static void register_command_task(uint32_t cookie)
1007 {
1008 struct command_task *ct = &command_task_struct;
1009 ct->fd = setup_command_socket_or_die();
1010 ct->cookie = cookie;
1011
1012 ct->task.pre_select = command_pre_select;
1013 ct->task.post_select = command_post_select;
1014 sprintf(ct->task.status, "command task");
1015 register_task(&ct->task);
1016 }
1017
1018 /**
1019 * Initialize the audio file selector process.
1020 *
1021 * \param cookie The value used for "authentication".
1022 * \param socket_fd File descriptor used for communication with the server.
1023 */
1024 __noreturn void afs_init(uint32_t cookie, int socket_fd)
1025 {
1026 static struct sched s;
1027 int i, ret;
1028
1029 register_signal_task();
1030 INIT_LIST_HEAD(&afs_client_list);
1031 for (i = 0; i < NUM_AFS_TABLES; i++)
1032 afs_tables[i].init(&afs_tables[i]);
1033 ret = open_afs_tables();
1034 if (ret < 0)
1035 goto out;
1036 server_socket = socket_fd;
1037 ret = mark_fd_nonblocking(server_socket);
1038 if (ret < 0)
1039 goto out_close;
1040 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1041 server_socket, (unsigned) cookie);
1042 init_admissible_files(conf.afs_initial_mode_arg);
1043 register_command_task(cookie);
1044 s.default_timeout.tv_sec = 0;
1045 s.default_timeout.tv_usec = 999 * 1000;
1046 ret = schedule(&s);
1047 out_close:
1048 close_afs_tables();
1049 out:
1050 if (ret < 0)
1051 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1052 exit(EXIT_FAILURE);
1053 }
1054
1055 static void create_tables_callback(int fd, const struct osl_object *query)
1056 {
1057 uint32_t table_mask = *(uint32_t *)query->data;
1058 int i, ret;
1059 char *buf;
1060
1061 close_afs_tables();
1062 for (i = 0; i < NUM_AFS_TABLES; i++) {
1063 struct afs_table *t = &afs_tables[i];
1064
1065 if (!(table_mask & (1 << i)))
1066 continue;
1067 if (!t->create)
1068 continue;
1069 ret = t->create(database_dir);
1070 if (ret < 0)
1071 goto out;
1072 }
1073 ret = open_afs_tables();
1074 out:
1075 if (ret >= 0)
1076 buf = make_message("successfully created afs table(s)\n");
1077 else
1078 buf = make_message("%s\n", para_strerror(-ret));
1079 pass_buffer_as_shm(buf, strlen(buf), &fd);
1080 free(buf);
1081 }
1082
1083 int com_init(int fd, int argc, char * const * const argv)
1084 {
1085 int i, j, ret;
1086 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1087 struct osl_object query = {.data = &table_mask,
1088 .size = sizeof(table_mask)};
1089
1090 ret = make_database_dir();
1091 if (ret < 0)
1092 return ret;
1093 if (argc != 1) {
1094 table_mask = 0;
1095 for (i = 1; i < argc; i++) {
1096 for (j = 0; j < NUM_AFS_TABLES; j++) {
1097 struct afs_table *t = &afs_tables[j];
1098
1099 if (strcmp(argv[i], t->name))
1100 continue;
1101 table_mask |= (1 << j);
1102 break;
1103 }
1104 if (j == NUM_AFS_TABLES)
1105 return -E_BAD_TABLE_NAME;
1106 }
1107 }
1108 ret = send_callback_request(create_tables_callback, &query, NULL, NULL);
1109 if (ret < 0)
1110 return send_va_buffer(fd, "%s\n", para_strerror(-ret));
1111 return ret;
1112 }
1113
1114 /**
1115 * Flags for the check command.
1116 *
1117 * \sa com_check().
1118 */
1119 enum com_check_flags {
1120 /** Check the audio file table. */
1121 CHECK_AFT = 1,
1122 /** Check the mood table. */
1123 CHECK_MOODS = 2,
1124 /** Check the playlist table. */
1125 CHECK_PLAYLISTS = 4
1126 };
1127
1128 int com_check(int fd, int argc, char * const * const argv)
1129 {
1130 unsigned flags = 0;
1131 int i, ret;
1132
1133 for (i = 1; i < argc; i++) {
1134 const char *arg = argv[i];
1135 if (arg[0] != '-')
1136 break;
1137 if (!strcmp(arg, "--")) {
1138 i++;
1139 break;
1140 }
1141 if (!strcmp(arg, "-a")) {
1142 flags |= CHECK_AFT;
1143 continue;
1144 }
1145 if (!strcmp(arg, "-p")) {
1146 flags |= CHECK_PLAYLISTS;
1147 continue;
1148 }
1149 if (!strcmp(arg, "-m")) {
1150 flags |= CHECK_MOODS;
1151 continue;
1152 }
1153 return -E_AFS_SYNTAX;
1154 }
1155 if (i < argc)
1156 return -E_AFS_SYNTAX;
1157 if (!flags)
1158 flags = ~0U;
1159 if (flags & CHECK_AFT) {
1160 ret = send_callback_request(aft_check_callback, NULL, send_result, &fd);
1161 if (ret < 0)
1162 return ret;
1163 }
1164 if (flags & CHECK_PLAYLISTS) {
1165 ret = send_callback_request(playlist_check_callback, NULL, send_result, &fd);
1166 if (ret < 0)
1167 return ret;
1168 }
1169 if (flags & CHECK_MOODS) {
1170 ret = send_callback_request(mood_check_callback, NULL, send_result, &fd);
1171 if (ret < 0)
1172 return ret;
1173 }
1174 return 1;
1175 }
1176
1177 void afs_event(enum afs_events event, struct para_buffer *pb,
1178 void *data)
1179 {
1180 int i, ret;
1181
1182 for (i = 0; i < NUM_AFS_TABLES; i++) {
1183 struct afs_table *t = &afs_tables[i];
1184 if (!t->event_handler)
1185 continue;
1186 ret = t->event_handler(event, pb, data);
1187 if (ret < 0)
1188 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1189 }
1190 }
1191
1192 int images_event_handler(__a_unused enum afs_events event,
1193 __a_unused struct para_buffer *pb, __a_unused void *data)
1194 {
1195 return 1;
1196 }
1197
1198 int lyrics_event_handler(__a_unused enum afs_events event,
1199 __a_unused struct para_buffer *pb, __a_unused void *data)
1200 {
1201 return 1;
1202 }