Fix para_strerror() and use osl() wrapper for osl library calls.
[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 <osl.h>
12 #include "server.cmdline.h"
13 #include "para.h"
14 #include "error.h"
15 #include "string.h"
16 #include "afh.h"
17 #include "afs.h"
18 #include "server.h"
19 #include <dirent.h> /* readdir() */
20 #include <sys/mman.h>
21 #include <sys/time.h>
22 #include "net.h"
23 #include "ipc.h"
24 #include "list.h"
25 #include "sched.h"
26 #include "signal.h"
27 #include "fd.h"
28
29 /** The osl tables used by afs. \sa blob.c. */
30 enum afs_table_num {
31 /** Contains audio file information. See aft.c. */
32 TBLNUM_AUDIO_FILES,
33 /** The table for the paraslash attributes. See attribute.c. */
34 TBLNUM_ATTRIBUTES,
35 /**
36 * Paraslash's scoring system is based on Gaussian normal
37 * distributions, and the relevant data is stored in the rbtrees of an
38 * osl table containing only volatile columns. See score.c for
39 * details.
40 */
41 TBLNUM_SCORES,
42 /**
43 * A standard blob table containing the mood definitions. For details
44 * see mood.c.
45 */
46 TBLNUM_MOODS,
47 /** A blob table containing lyrics on a per-song basis. */
48 TBLNUM_LYRICS,
49 /** Another blob table for images (for example album cover art). */
50 TBLNUM_IMAGES,
51 /** Yet another blob table for storing standard playlists. */
52 TBLNUM_PLAYLIST,
53 /** How many tables are in use? */
54 NUM_AFS_TABLES
55 };
56
57 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
58 [TBLNUM_AUDIO_FILES] = {.init = aft_init},
59 [TBLNUM_ATTRIBUTES] = {.init = attribute_init},
60 [TBLNUM_SCORES] = {.init = score_init},
61 [TBLNUM_MOODS] = {.init = moods_init},
62 [TBLNUM_LYRICS] = {.init = lyrics_init},
63 [TBLNUM_IMAGES] = {.init = images_init},
64 [TBLNUM_PLAYLIST] = {.init = playlists_init},
65 };
66
67 struct command_task {
68 /** The file descriptor for the local socket. */
69 int fd;
70 /**
71 * Value sent by the command handlers to identify themselves as
72 * children of the running para_server.
73 */
74 uint32_t cookie;
75 /** The associated task structure. */
76 struct task task;
77 };
78
79 extern int mmd_mutex;
80 extern struct misc_meta_data *mmd;
81
82 static int server_socket;
83 static struct command_task command_task_struct;
84 static struct signal_task signal_task_struct;
85
86 static enum play_mode current_play_mode;
87 static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
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(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 Standard.
373 */
374 int for_each_matching_row(struct pattern_match_data *pmd)
375 {
376 if (pmd->pm_flags & PM_REVERSE_LOOP)
377 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
378 action_if_pattern_matches));
379 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
380 action_if_pattern_matches));
381 }
382
383 /**
384 * Compare two osl objects of string type.
385 *
386 * \param obj1 Pointer to the first object.
387 * \param obj2 Pointer to the second object.
388 *
389 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
390 * are taken into account.
391 *
392 * \return It returns an integer less than, equal to, or greater than zero if
393 * \a obj1 is found, respectively, to be less than, to match, or be greater than
394 * obj2.
395 *
396 * \sa strcmp(3), strncmp(3), osl_compare_func.
397 */
398 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
399 {
400 const char *str1 = (const char *)obj1->data;
401 const char *str2 = (const char *)obj2->data;
402 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
403 }
404
405 /*
406 * write input from fd to dynamically allocated buffer,
407 * but maximal max_size byte.
408 */
409 static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
410 {
411 const size_t chunk_size = 1024;
412 size_t size = 2048, received = 0;
413 int ret;
414 char *buf = para_malloc(size);
415
416 for (;;) {
417 ret = recv_bin_buffer(fd, buf + received, chunk_size);
418 if (ret <= 0)
419 break;
420 received += ret;
421 if (received + chunk_size >= size) {
422 size *= 2;
423 ret = -E_INPUT_TOO_LARGE;
424 if (size > max_size)
425 break;
426 buf = para_realloc(buf, size);
427 }
428 }
429 obj->data = buf;
430 obj->size = received;
431 if (ret < 0)
432 free(buf);
433 return ret;
434 }
435
436 /**
437 * Read data from a file descriptor, and send it to the afs process.
438 *
439 * \param fd File descriptor to read data from.
440 * \param arg_obj Pointer to the arguments to \a f.
441 * \param f The callback function.
442 * \param max_len Don't read more than that many bytes from stdin.
443 * \param result_handler See \ref send_callback_request.
444 * \param private_result_data See \ref send_callback_request.
445 *
446 * This function is used by commands that wish to let para_server store
447 * arbitrary data specified by the user (for instance the add_blob family of
448 * commands). First, at most \a max_len bytes are read from \a fd, the result
449 * is concatenated with the buffer given by \a arg_obj, and the combined buffer
450 * is made available to the afs process via the callback method. See \ref
451 * send_callback_request for details.
452 *
453 * \return Negative on errors, the return value of the underlying call to
454 * send_callback_request() otherwise.
455 */
456 int stdin_command(int fd, struct osl_object *arg_obj, callback_function *f,
457 unsigned max_len, callback_result_handler *result_handler,
458 void *private_result_data)
459 {
460 struct osl_object query, stdin_obj;
461 int ret;
462
463 ret = send_buffer(fd, AWAITING_DATA_MSG);
464 if (ret < 0)
465 return ret;
466 ret = fd2buf(fd, max_len, &stdin_obj);
467 if (ret < 0)
468 return ret;
469 query.size = arg_obj->size + stdin_obj.size;
470 query.data = para_malloc(query.size);
471 memcpy(query.data, arg_obj->data, arg_obj->size);
472 memcpy((char *)query.data + arg_obj->size, stdin_obj.data, stdin_obj.size);
473 free(stdin_obj.data);
474 ret = send_callback_request(f, &query, result_handler, private_result_data);
475 free(query.data);
476 return ret;
477 }
478
479 static int pass_afd(int fd, char *buf, size_t size)
480 {
481 struct msghdr msg = {.msg_iov = NULL};
482 struct cmsghdr *cmsg;
483 char control[255];
484 int ret;
485 struct iovec iov;
486
487 iov.iov_base = buf;
488 iov.iov_len = size;
489
490 msg.msg_iov = &iov;
491 msg.msg_iovlen = 1;
492
493 msg.msg_control = control;
494 msg.msg_controllen = sizeof(control);
495
496 cmsg = CMSG_FIRSTHDR(&msg);
497 cmsg->cmsg_level = SOL_SOCKET;
498 cmsg->cmsg_type = SCM_RIGHTS;
499 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
500 *(int *)CMSG_DATA(cmsg) = fd;
501
502 /* Sum of the length of all control messages in the buffer */
503 msg.msg_controllen = cmsg->cmsg_len;
504 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
505 ret = sendmsg(server_socket, &msg, 0);
506 if (ret < 0) {
507 ret = -ERRNO_TO_PARA_ERROR(errno);
508 return ret;
509 }
510 return 1;
511 }
512
513 /**
514 * Open the audio file with highest score.
515 *
516 * This stores all information for streaming the "best" audio file in a shared
517 * memory area. The id of that area and an open file descriptor for the next
518 * audio file are passed to the server process.
519 *
520 * \return Standard.
521 *
522 * \sa open_and_update_audio_file().
523 */
524 static int open_next_audio_file(void)
525 {
526 struct osl_row *aft_row;
527 struct audio_file_data afd;
528 int ret, shmid;
529 char buf[8];
530 long score;
531 again:
532 PARA_NOTICE_LOG("getting next audio file\n");
533 ret = score_get_best(&aft_row, &score);
534 if (ret < 0) {
535 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
536 goto no_admissible_files;
537 }
538 ret = open_and_update_audio_file(aft_row, score, &afd);
539 if (ret < 0) {
540 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
541 ret = score_delete(aft_row);
542 if (ret < 0) {
543 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
544 goto no_admissible_files;
545 }
546 goto again;
547 }
548 shmid = ret;
549 if (!write_ok(server_socket)) {
550 ret = -E_AFS_SOCKET;
551 goto destroy;
552 }
553 *(uint32_t *)buf = NEXT_AUDIO_FILE;
554 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
555 ret = pass_afd(afd.fd, buf, 8);
556 close(afd.fd);
557 if (ret >= 0)
558 return ret;
559 destroy:
560 shm_destroy(shmid);
561 return ret;
562 no_admissible_files:
563 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
564 *(uint32_t *)(buf + 4) = (uint32_t)0;
565 return send_bin_buffer(server_socket, buf, 8);
566 }
567
568 /* Never fails if arg == NULL */
569 static int activate_mood_or_playlist(char *arg, int *num_admissible)
570 {
571 enum play_mode mode;
572 int ret;
573
574 if (!arg) {
575 ret = change_current_mood(NULL); /* always successful */
576 mode = PLAY_MODE_MOOD;
577 } else {
578 if (!strncmp(arg, "p/", 2)) {
579 ret = playlist_open(arg + 2);
580 mode = PLAY_MODE_PLAYLIST;
581 } else if (!strncmp(arg, "m/", 2)) {
582 ret = change_current_mood(arg + 2);
583 mode = PLAY_MODE_MOOD;
584 } else
585 return -E_AFS_SYNTAX;
586 if (ret < 0)
587 return ret;
588 }
589 if (num_admissible)
590 *num_admissible = ret;
591 current_play_mode = mode;
592 if (arg != current_mop) {
593 free(current_mop);
594 if (arg) {
595 current_mop = para_strdup(arg);
596 mutex_lock(mmd_mutex);
597 strncpy(mmd->afs_mode_string, arg,
598 sizeof(mmd->afs_mode_string));
599 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
600 mutex_unlock(mmd_mutex);
601 } else {
602 mutex_lock(mmd_mutex);
603 strcpy(mmd->afs_mode_string, "dummy");
604 mutex_unlock(mmd_mutex);
605 current_mop = NULL;
606 }
607 }
608 return 1;
609 }
610
611 static void com_select_callback(int fd, const struct osl_object *query)
612 {
613 struct para_buffer pb = {
614 .max_size = SHMMAX,
615 .private_data = &fd,
616 .max_size_handler = pass_buffer_as_shm
617 };
618 char *arg = query->data;
619 int num_admissible, ret, ret2;
620
621 ret = clear_score_table();
622 if (ret < 0) {
623 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
624 goto out;
625 }
626 if (current_play_mode == PLAY_MODE_MOOD)
627 close_current_mood();
628 else
629 playlist_close();
630 ret = activate_mood_or_playlist(arg, &num_admissible);
631 if (ret < 0) {
632 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
633 para_strerror(-ret), current_mop?
634 current_mop : "dummy");
635 ret = activate_mood_or_playlist(current_mop, &num_admissible);
636 if (ret < 0) {
637 if (ret2 >= 0)
638 ret2 = para_printf(&pb, "failed, switching to dummy\n");
639 activate_mood_or_playlist(NULL, &num_admissible);
640 }
641 } else
642 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
643 current_mop : "dummy mood", num_admissible);
644 out:
645 if (ret2 >= 0 && pb.offset)
646 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
647 free(pb.buf);
648 }
649
650 /**
651 * Result handler for sending data to the para_client process.
652 *
653 * \param result The data to be sent.
654 * \param fd_ptr Pointer to the file descriptor.
655 *
656 * \return The return value of the underlying call to send_bin_buffer().
657 *
658 * \sa \ref callback_result_handler.
659 */
660 int send_result(struct osl_object *result, void *fd_ptr)
661 {
662 int fd = *(int *)fd_ptr;
663 if (!result->size)
664 return 1;
665 return send_bin_buffer(fd, result->data, result->size);
666 }
667
668 int com_select(int fd, int argc, char * const * const argv)
669 {
670 struct osl_object query;
671
672 if (argc != 2)
673 return -E_AFS_SYNTAX;
674 query.data = argv[1];
675 query.size = strlen(argv[1]) + 1;
676 return send_callback_request(com_select_callback, &query,
677 &send_result, &fd);
678 }
679
680 static void init_admissible_files(char *arg)
681 {
682 if (activate_mood_or_playlist(arg, NULL) < 0)
683 activate_mood_or_playlist(NULL, NULL); /* always successful */
684 }
685
686 static int setup_command_socket_or_die(void)
687 {
688 int ret, socket_fd;
689 char *socket_name = conf.afs_socket_arg;
690 struct sockaddr_un unix_addr;
691
692 unlink(socket_name);
693 ret = create_local_socket(socket_name, &unix_addr,
694 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
695 if (ret < 0) {
696 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
697 exit(EXIT_FAILURE);
698 }
699 socket_fd = ret;
700 if (listen(socket_fd , 5) < 0) {
701 PARA_EMERG_LOG("can not listen on socket\n");
702 exit(EXIT_FAILURE);
703 }
704 ret = mark_fd_nonblocking(socket_fd);
705 if (ret < 0) {
706 close(socket_fd);
707 return ret;
708 }
709 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
710 socket_fd);
711 return socket_fd;
712 }
713
714 static void close_afs_tables(void)
715 {
716 int i;
717 PARA_NOTICE_LOG("closing afs_tables\n");
718 for (i = 0; i < NUM_AFS_TABLES; i++)
719 afs_tables[i].close();
720 }
721
722 static char *database_dir;
723
724 static void get_database_dir(void)
725 {
726 if (!database_dir) {
727 if (conf.afs_database_dir_given)
728 database_dir = para_strdup(conf.afs_database_dir_arg);
729 else {
730 char *home = para_homedir();
731 database_dir = make_message(
732 "%s/.paraslash/afs_database", home);
733 free(home);
734 }
735 }
736 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
737 }
738
739 static int make_database_dir(void)
740 {
741 int ret;
742
743 get_database_dir();
744 ret = para_mkdir(database_dir, 0777);
745 if (ret >= 0 || is_errno(-ret, EEXIST))
746 return 1;
747 return ret;
748 }
749
750 static int open_afs_tables(void)
751 {
752 int i, ret;
753
754 get_database_dir();
755 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
756 database_dir);
757 for (i = 0; i < NUM_AFS_TABLES; i++) {
758 ret = afs_tables[i].open(database_dir);
759 if (ret >= 0)
760 continue;
761 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
762 para_strerror(-ret));
763 break;
764 }
765 if (ret >= 0)
766 return ret;
767 while (i)
768 afs_tables[--i].close();
769 return ret;
770 }
771
772 static void signal_pre_select(struct sched *s, struct task *t)
773 {
774 struct signal_task *st = container_of(t, struct signal_task, task);
775 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
776 }
777
778 static void afs_signal_post_select(struct sched *s, struct task *t)
779 {
780 struct signal_task *st = container_of(t, struct signal_task, task);
781 if (getppid() == 1) {
782 PARA_EMERG_LOG("para_server died\n");
783 goto shutdown;
784 }
785 if (!FD_ISSET(st->fd, &s->rfds))
786 return;
787 st->signum = para_next_signal();
788 if (st->signum == SIGHUP) {
789 close_afs_tables();
790 parse_config_or_die(1);
791 t->error = open_afs_tables();
792 if (t->error < 0)
793 return;
794 init_admissible_files(current_mop);
795 return;
796 }
797 PARA_EMERG_LOG("terminating on signal %d\n", st->signum);
798 shutdown:
799 sched_shutdown();
800 t->error = -E_AFS_SIGNAL;
801 }
802
803 static void register_signal_task(void)
804 {
805 struct signal_task *st = &signal_task_struct;
806
807 para_sigaction(SIGPIPE, SIG_IGN);
808 st->fd = para_signal_init();
809 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
810 para_install_sighandler(SIGINT);
811 para_install_sighandler(SIGTERM);
812 para_install_sighandler(SIGHUP);
813
814 st->task.pre_select = signal_pre_select;
815 st->task.post_select = afs_signal_post_select;
816 sprintf(st->task.status, "signal task");
817 register_task(&st->task);
818 }
819
820 static struct list_head afs_client_list;
821
822 /** Describes on connected afs client. */
823 struct afs_client {
824 /** Position in the afs client list. */
825 struct list_head node;
826 /** The socket file descriptor for this client. */
827 int fd;
828 /** The time the client connected. */
829 struct timeval connect_time;
830 };
831
832 static void command_pre_select(struct sched *s, struct task *t)
833 {
834 struct command_task *ct = container_of(t, struct command_task, task);
835 struct afs_client *client;
836
837 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
838 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
839 list_for_each_entry(client, &afs_client_list, node)
840 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
841 }
842
843 /**
844 * Send data as shared memory to a file descriptor.
845 *
846 * \param buf The buffer holding the data to be sent.
847 * \param size The size of \a buf.
848 * \param fd_ptr A pointer to the file descriptor.
849 *
850 * This function is used as the \a max_size handler in a \ref para_buffer
851 * structure. If used this way, it is called by \ref para_printf() whenever
852 * the buffer passed to para_printf() is about to exceed its maximal size.
853 *
854 * This function creates a shared memory area large enough to hold
855 * the content given by \a buf and \a size and sends the identifier
856 * of this area to the file descriptor given by \a fd_ptr.
857 *
858 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
859 * and positive on success.
860 */
861 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
862 {
863 int ret, shmid, fd = *(int *)fd_ptr;
864 void *shm;
865 struct callback_result *cr;
866
867 if (!buf || !size)
868 return 0;
869 ret = shm_new(size + sizeof(struct callback_result));
870 if (ret < 0)
871 return ret;
872 shmid = ret;
873 ret = shm_attach(shmid, ATTACH_RW, &shm);
874 if (ret < 0)
875 goto err;
876 cr = shm;
877 cr->result_size = size;
878 memcpy(shm + sizeof(*cr), buf, size);
879 ret = shm_detach(shm);
880 if (ret < 0)
881 goto err;
882 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
883 if (ret >= 0)
884 return ret;
885 err:
886 if (shm_destroy(shmid) < 0)
887 PARA_ERROR_LOG("destroy result failed\n");
888 return ret;
889 }
890
891 /*
892 * On errors, negative value is written to fd.
893 * On success: If query produced a result, the result_shmid is written to fd.
894 * Otherwise, zero is written.
895 */
896 static int call_callback(int fd, int query_shmid)
897 {
898 void *query_shm;
899 struct callback_query *cq;
900 struct osl_object query;
901 int ret;
902
903 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
904 if (ret < 0)
905 return ret;
906 cq = query_shm;
907 query.data = (char *)query_shm + sizeof(*cq);
908 query.size = cq->query_size;
909 cq->handler(fd, &query);
910 return shm_detach(query_shm);
911 }
912
913 static int execute_server_command(void)
914 {
915 char buf[8];
916 int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
917
918 if (ret <= 0) {
919 if (!ret)
920 ret = -ERRNO_TO_PARA_ERROR(ECONNRESET);
921 goto err;
922 }
923 buf[ret] = '\0';
924 PARA_DEBUG_LOG("received: %s\n", buf);
925 ret = -E_BAD_CMD;
926 if (strcmp(buf, "new"))
927 goto err;
928 ret = open_next_audio_file();
929 err:
930 return ret;
931 }
932
933 static void execute_afs_command(int fd, uint32_t expected_cookie)
934 {
935 uint32_t cookie;
936 int query_shmid;
937 char buf[sizeof(cookie) + sizeof(query_shmid)];
938 int ret = recv_bin_buffer(fd, buf, sizeof(buf));
939
940 if (ret < 0)
941 goto err;
942 if (ret != sizeof(buf)) {
943 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
944 ret, (long unsigned) sizeof(buf));
945 return;
946 }
947 cookie = *(uint32_t *)buf;
948 if (cookie != expected_cookie) {
949 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
950 (unsigned)cookie, (unsigned)expected_cookie);
951 return;
952 }
953 query_shmid = *(int *)(buf + sizeof(cookie));
954 if (query_shmid < 0) {
955 PARA_WARNING_LOG("received invalid query shmid %d)\n",
956 query_shmid);
957 return;
958 }
959 ret = call_callback(fd, query_shmid);
960 if (ret >= 0)
961 return;
962 err:
963 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
964 }
965
966 /** Shutdown connection if query has not arrived until this many seconds. */
967 #define AFS_CLIENT_TIMEOUT 3
968
969 static void command_post_select(struct sched *s, struct task *t)
970 {
971 struct command_task *ct = container_of(t, struct command_task, task);
972 struct sockaddr_un unix_addr;
973 struct afs_client *client, *tmp;
974 int fd, ret;
975
976 if (FD_ISSET(server_socket, &s->rfds)) {
977 ret = execute_server_command();
978 if (ret < 0) {
979 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
980 sched_shutdown();
981 return;
982 }
983 }
984
985 /* Check the list of connected clients. */
986 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
987 if (FD_ISSET(client->fd, &s->rfds))
988 execute_afs_command(client->fd, ct->cookie);
989 else { /* prevent bogus connection flooding */
990 struct timeval diff;
991 tv_diff(now, &client->connect_time, &diff);
992 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
993 continue;
994 PARA_WARNING_LOG("connection timeout\n");
995 }
996 close(client->fd);
997 list_del(&client->node);
998 free(client);
999 }
1000 /* Accept connections on the local socket. */
1001 if (!FD_ISSET(ct->fd, &s->rfds))
1002 return;
1003 ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
1004 if (ret < 0) {
1005 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1006 return;
1007 }
1008 fd = ret;
1009 ret = mark_fd_nonblocking(fd);
1010 if (ret < 0) {
1011 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1012 close(fd);
1013 return;
1014 }
1015 client = para_malloc(sizeof(*client));
1016 client->fd = fd;
1017 client->connect_time = *now;
1018 para_list_add(&client->node, &afs_client_list);
1019 }
1020
1021 static void register_command_task(uint32_t cookie)
1022 {
1023 struct command_task *ct = &command_task_struct;
1024 ct->fd = setup_command_socket_or_die();
1025 ct->cookie = cookie;
1026
1027 ct->task.pre_select = command_pre_select;
1028 ct->task.post_select = command_post_select;
1029 sprintf(ct->task.status, "command task");
1030 register_task(&ct->task);
1031 }
1032
1033 /**
1034 * Initialize the audio file selector process.
1035 *
1036 * \param cookie The value used for "authentication".
1037 * \param socket_fd File descriptor used for communication with the server.
1038 */
1039 __noreturn void afs_init(uint32_t cookie, int socket_fd)
1040 {
1041 static struct sched s;
1042 int i, ret;
1043
1044 register_signal_task();
1045 INIT_LIST_HEAD(&afs_client_list);
1046 for (i = 0; i < NUM_AFS_TABLES; i++)
1047 afs_tables[i].init(&afs_tables[i]);
1048 ret = open_afs_tables();
1049 if (ret < 0)
1050 goto out;
1051 server_socket = socket_fd;
1052 ret = mark_fd_nonblocking(server_socket);
1053 if (ret < 0)
1054 goto out_close;
1055 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1056 server_socket, (unsigned) cookie);
1057 init_admissible_files(conf.afs_initial_mode_arg);
1058 register_command_task(cookie);
1059 s.default_timeout.tv_sec = 0;
1060 s.default_timeout.tv_usec = 999 * 1000;
1061 ret = schedule(&s);
1062 out_close:
1063 close_afs_tables();
1064 out:
1065 if (ret < 0)
1066 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1067 exit(EXIT_FAILURE);
1068 }
1069
1070 static void create_tables_callback(int fd, const struct osl_object *query)
1071 {
1072 uint32_t table_mask = *(uint32_t *)query->data;
1073 int i, ret;
1074 char *buf;
1075
1076 close_afs_tables();
1077 for (i = 0; i < NUM_AFS_TABLES; i++) {
1078 struct afs_table *t = &afs_tables[i];
1079
1080 if (!(table_mask & (1 << i)))
1081 continue;
1082 if (!t->create)
1083 continue;
1084 ret = t->create(database_dir);
1085 if (ret < 0)
1086 goto out;
1087 }
1088 ret = open_afs_tables();
1089 out:
1090 if (ret >= 0)
1091 buf = make_message("successfully created afs table(s)\n");
1092 else
1093 buf = make_message("%s\n", para_strerror(-ret));
1094 pass_buffer_as_shm(buf, strlen(buf), &fd);
1095 free(buf);
1096 }
1097
1098 int com_init(int fd, int argc, char * const * const argv)
1099 {
1100 int i, j, ret;
1101 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1102 struct osl_object query = {.data = &table_mask,
1103 .size = sizeof(table_mask)};
1104
1105 ret = make_database_dir();
1106 if (ret < 0)
1107 return ret;
1108 if (argc != 1) {
1109 table_mask = 0;
1110 for (i = 1; i < argc; i++) {
1111 for (j = 0; j < NUM_AFS_TABLES; j++) {
1112 struct afs_table *t = &afs_tables[j];
1113
1114 if (strcmp(argv[i], t->name))
1115 continue;
1116 table_mask |= (1 << j);
1117 break;
1118 }
1119 if (j == NUM_AFS_TABLES)
1120 return -E_BAD_TABLE_NAME;
1121 }
1122 }
1123 ret = send_callback_request(create_tables_callback, &query, &send_result, &fd);
1124 if (ret < 0)
1125 return send_va_buffer(fd, "%s\n", para_strerror(-ret));
1126 return ret;
1127 }
1128
1129 /**
1130 * Flags for the check command.
1131 *
1132 * \sa com_check().
1133 */
1134 enum com_check_flags {
1135 /** Check the audio file table. */
1136 CHECK_AFT = 1,
1137 /** Check the mood table. */
1138 CHECK_MOODS = 2,
1139 /** Check the playlist table. */
1140 CHECK_PLAYLISTS = 4
1141 };
1142
1143 int com_check(int fd, int argc, char * const * const argv)
1144 {
1145 unsigned flags = 0;
1146 int i, ret;
1147
1148 for (i = 1; i < argc; i++) {
1149 const char *arg = argv[i];
1150 if (arg[0] != '-')
1151 break;
1152 if (!strcmp(arg, "--")) {
1153 i++;
1154 break;
1155 }
1156 if (!strcmp(arg, "-a")) {
1157 flags |= CHECK_AFT;
1158 continue;
1159 }
1160 if (!strcmp(arg, "-p")) {
1161 flags |= CHECK_PLAYLISTS;
1162 continue;
1163 }
1164 if (!strcmp(arg, "-m")) {
1165 flags |= CHECK_MOODS;
1166 continue;
1167 }
1168 return -E_AFS_SYNTAX;
1169 }
1170 if (i < argc)
1171 return -E_AFS_SYNTAX;
1172 if (!flags)
1173 flags = ~0U;
1174 if (flags & CHECK_AFT) {
1175 ret = send_callback_request(aft_check_callback, NULL, send_result, &fd);
1176 if (ret < 0)
1177 return ret;
1178 }
1179 if (flags & CHECK_PLAYLISTS) {
1180 ret = send_callback_request(playlist_check_callback, NULL, send_result, &fd);
1181 if (ret < 0)
1182 return ret;
1183 }
1184 if (flags & CHECK_MOODS) {
1185 ret = send_callback_request(mood_check_callback, NULL, send_result, &fd);
1186 if (ret < 0)
1187 return ret;
1188 }
1189 return 1;
1190 }
1191
1192 /**
1193 * The afs event dispatcher.
1194 *
1195 * \param event Type of the event.
1196 * \param pb May be \p NULL.
1197 * \param data Type depends on \a event.
1198 *
1199 * This function calls the table handlers of all tables and passes \a pb and \a
1200 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1201 */
1202 void afs_event(enum afs_events event, struct para_buffer *pb,
1203 void *data)
1204 {
1205 int i, ret;
1206
1207 for (i = 0; i < NUM_AFS_TABLES; i++) {
1208 struct afs_table *t = &afs_tables[i];
1209 if (!t->event_handler)
1210 continue;
1211 ret = t->event_handler(event, pb, data);
1212 if (ret < 0)
1213 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1214 event, para_strerror(-ret));
1215 }
1216 }
1217
1218 int images_event_handler(__a_unused enum afs_events event,
1219 __a_unused struct para_buffer *pb, __a_unused void *data)
1220 {
1221 return 1;
1222 }
1223
1224 int lyrics_event_handler(__a_unused enum afs_events event,
1225 __a_unused struct para_buffer *pb, __a_unused void *data)
1226 {
1227 return 1;
1228 }