server: Convert com_select() to lopsub.
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>
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 <netinet/in.h>
10 #include <sys/socket.h>
11 #include <regex.h>
12 #include <signal.h>
13 #include <fnmatch.h>
14 #include <osl.h>
15 #include <lopsub.h>
16 #include <arpa/inet.h>
17 #include <sys/un.h>
18 #include <netdb.h>
19 #include <lopsub.h>
20
21 #include "server_cmd.lsg.h"
22 #include "server.cmdline.h"
23 #include "para.h"
24 #include "error.h"
25 #include "crypt.h"
26 #include "string.h"
27 #include "afh.h"
28 #include "afs.h"
29 #include "server.h"
30 #include "net.h"
31 #include "ipc.h"
32 #include "list.h"
33 #include "sched.h"
34 #include "fd.h"
35 #include "signal.h"
36 #include "mood.h"
37 #include "sideband.h"
38 #include "command.h"
39
40 /** The osl tables used by afs. \sa blob.c. */
41 enum afs_table_num {
42 /** Contains audio file information. See aft.c. */
43 TBLNUM_AUDIO_FILES,
44 /** The table for the paraslash attributes. See attribute.c. */
45 TBLNUM_ATTRIBUTES,
46 /**
47 * Paraslash's scoring system is based on Gaussian normal
48 * distributions, and the relevant data is stored in the rbtrees of an
49 * osl table containing only volatile columns. See score.c for
50 * details.
51 */
52 TBLNUM_SCORES,
53 /**
54 * A standard blob table containing the mood definitions. For details
55 * see mood.c.
56 */
57 TBLNUM_MOODS,
58 /** A blob table containing lyrics on a per-song basis. */
59 TBLNUM_LYRICS,
60 /** Another blob table for images (for example album cover art). */
61 TBLNUM_IMAGES,
62 /** Yet another blob table for storing standard playlists. */
63 TBLNUM_PLAYLIST,
64 /** How many tables are in use? */
65 NUM_AFS_TABLES
66 };
67
68 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
69 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
70 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
71 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
72 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
73 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
74 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
75 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
76 };
77
78 struct command_task {
79 /** The file descriptor for the local socket. */
80 int fd;
81 /**
82 * Value sent by the command handlers to identify themselves as
83 * children of the running para_server.
84 */
85 uint32_t cookie;
86 /** The associated task structure. */
87 struct task *task;
88 };
89
90 extern int mmd_mutex;
91 extern struct misc_meta_data *mmd;
92
93 static int server_socket;
94 static struct command_task command_task_struct;
95 static struct signal_task *signal_task;
96
97 static enum play_mode current_play_mode;
98 static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
99
100 /**
101 * A random number used to "authenticate" the connection.
102 *
103 * para_server picks this number by random before it forks the afs process. The
104 * command handlers know this number as well and write it to the afs socket,
105 * together with the id of the shared memory area which contains the payload of
106 * the afs command. A local process has to know this number to abuse the afs
107 * service provided by the local socket.
108 */
109 extern uint32_t afs_socket_cookie;
110
111 /**
112 * Struct to let command handlers execute a callback in afs context.
113 *
114 * Commands that need to change the state of afs can't change the relevant data
115 * structures directly because commands are executed in a child process, i.e.
116 * they get their own virtual address space.
117 *
118 * This structure is used by \p send_callback_request() (executed from handler
119 * context) in order to let the afs process call the specified function. An
120 * instance of that structure is written to a shared memory area together with
121 * the arguments to the callback function. The identifier of the shared memory
122 * area is written to the command socket.
123 *
124 * The afs process accepts connections on the command socket and reads the
125 * shared memory id, attaches the corresponding area, calls the given handler to
126 * perform the desired action and to optionally compute a result.
127 *
128 * The result and a \p callback_result structure is then written to another
129 * shared memory area. The identifier for that area is written to the handler's
130 * command socket, so that the handler process can read the id, attach the
131 * shared memory area and use the result.
132 *
133 * \sa struct callback_result.
134 */
135 struct callback_query {
136 /** The function to be called. */
137 afs_callback *handler;
138 /** The number of bytes of the query */
139 size_t query_size;
140 };
141
142 /**
143 * Structure embedded in the result of a callback.
144 *
145 * If the callback produced a result, an instance of that structure is embedded
146 * into the shared memory area holding the result, mainly to let the command
147 * handler know the size of the result.
148 *
149 * \sa struct callback_query.
150 */
151 struct callback_result {
152 /** The number of bytes of the result. */
153 size_t result_size;
154 /** The band designator (loglevel for the result). */
155 uint8_t band;
156 };
157
158 static int dispatch_result(int result_shmid, callback_result_handler *handler,
159 void *private_result_data)
160 {
161 struct osl_object result;
162 void *result_shm;
163 /* must attach r/w as result.data might get encrypted in-place. */
164 int ret2, ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
165 struct callback_result *cr = result_shm;
166
167 if (ret < 0) {
168 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
169 return ret;
170 }
171 result.size = cr->result_size;
172 result.data = result_shm + sizeof(*cr);
173 assert(handler);
174 ret = handler(&result, cr->band, private_result_data);
175 ret2 = shm_detach(result_shm);
176 if (ret2 < 0) {
177 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
178 if (ret >= 0)
179 ret = ret2;
180 }
181 return ret;
182 }
183
184 /**
185 * Ask the afs process to call a given function.
186 *
187 * \param f The function to be called.
188 * \param query Pointer to arbitrary data for the callback.
189 * \param result_handler Called for each shm area sent by the callback.
190 * \param private_result_data Passed verbatim to \a result_handler.
191 *
192 * This function creates a socket for communication with the afs process and a
193 * shared memory area (sma) to which the buffer pointed to by \a query is
194 * copied. It then notifies the afs process that the callback function \a f
195 * should be executed by sending the shared memory identifier (shmid) to the
196 * socket.
197 *
198 * If the callback produces a result, it sends any number of shared memory
199 * identifiers back via the socket. For each such identifier received, \a
200 * result_handler is called. The contents of the sma identified by the received
201 * shmid are passed to that function as an osl object. The private_result_data
202 * pointer is passed as the second argument to \a result_handler.
203 *
204 * \return Number of shared memory areas dispatched on success, negative on errors.
205 *
206 * \sa send_option_arg_callback_request(), send_standard_callback_request().
207 */
208 int send_callback_request(afs_callback *f, struct osl_object *query,
209 callback_result_handler *result_handler,
210 void *private_result_data)
211 {
212 struct callback_query *cq;
213 int ret, fd = -1, query_shmid, result_shmid;
214 void *query_shm;
215 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
216 size_t query_shm_size = sizeof(*cq);
217 int dispatch_error = 0, num_dispatched = 0;
218
219 if (query)
220 query_shm_size += query->size;
221 ret = shm_new(query_shm_size);
222 if (ret < 0)
223 return ret;
224 query_shmid = ret;
225 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
226 if (ret < 0)
227 goto out;
228 cq = query_shm;
229 cq->handler = f;
230 cq->query_size = query_shm_size - sizeof(*cq);
231
232 if (query)
233 memcpy(query_shm + sizeof(*cq), query->data, query->size);
234 ret = shm_detach(query_shm);
235 if (ret < 0)
236 goto out;
237
238 *(uint32_t *)buf = afs_socket_cookie;
239 *(int *)(buf + sizeof(afs_socket_cookie)) = query_shmid;
240
241 ret = connect_local_socket(conf.afs_socket_arg);
242 if (ret < 0)
243 goto out;
244 fd = ret;
245 ret = write_all(fd, buf, sizeof(buf));
246 if (ret < 0)
247 goto out;
248 /*
249 * Read all shmids from afs.
250 *
251 * Even if the dispatcher returns an error we _must_ continue to read
252 * shmids from fd so that we can destroy all shared memory areas that
253 * have been created for us by the afs process.
254 */
255 for (;;) {
256 ret = recv_bin_buffer(fd, buf, sizeof(int));
257 if (ret <= 0)
258 goto out;
259 assert(ret == sizeof(int));
260 ret = *(int *) buf;
261 assert(ret > 0);
262 result_shmid = ret;
263 ret = dispatch_result(result_shmid, result_handler,
264 private_result_data);
265 if (ret < 0 && dispatch_error >= 0)
266 dispatch_error = ret;
267 ret = shm_destroy(result_shmid);
268 if (ret < 0)
269 PARA_CRIT_LOG("destroy result failed: %s\n",
270 para_strerror(-ret));
271 num_dispatched++;
272 }
273 out:
274 if (shm_destroy(query_shmid) < 0)
275 PARA_CRIT_LOG("shm destroy error\n");
276 if (fd >= 0)
277 close(fd);
278 if (dispatch_error < 0)
279 return dispatch_error;
280 if (ret < 0)
281 return ret;
282 return num_dispatched;
283 }
284
285 /**
286 * Wrapper for send_callback_request() which passes a lopsub parse result.
287 *
288 * \param f The callback function.
289 * \param cmd Needed for (de-)serialization.
290 * \param lpr Must match cmd.
291 * \param private_result_data Passed to send_callback_request().
292 *
293 * This function serializes the parse result given by the lpr pointer into a
294 * buffer. The buffer is sent as the query to the afs process with the callback
295 * mechanism.
296 *
297 * \return The return value of the underlying call to send_callback_request().
298 */
299 int send_lls_callback_request(afs_callback *f,
300 const struct lls_command * const cmd,
301 struct lls_parse_result *lpr, void *private_result_data)
302 {
303 struct osl_object query;
304 char *buf = NULL;
305 int ret = lls_serialize_parse_result(lpr, cmd, &buf, &query.size);
306
307 assert(ret >= 0);
308 query.data = buf;
309 ret = send_callback_request(f, &query, afs_cb_result_handler,
310 private_result_data);
311 free(buf);
312 return ret;
313 }
314
315 /**
316 * Send a callback request passing an options structure and an argument vector.
317 *
318 * \param options pointer to an arbitrary data structure.
319 * \param argc Argument count.
320 * \param argv Standard argument vector.
321 * \param f The callback function.
322 * \param result_handler See \ref send_callback_request.
323 * \param private_result_data See \ref send_callback_request.
324 *
325 * Some command handlers pass command-specific options to a callback, together
326 * with a list of further arguments (often a list of audio files). This
327 * function allows to pass an arbitrary structure (given as an osl object) and
328 * a usual argument vector to the specified callback.
329 *
330 * \return The return value of the underlying call to \ref
331 * send_callback_request().
332 *
333 * \sa send_standard_callback_request(), send_callback_request().
334 */
335 int send_option_arg_callback_request(struct osl_object *options,
336 int argc, char * const * const argv, afs_callback *f,
337 callback_result_handler *result_handler,
338 void *private_result_data)
339 {
340 char *p;
341 int i, ret;
342 struct osl_object query = {.size = options? options->size : 0};
343
344 for (i = 0; i < argc; i++)
345 query.size += strlen(argv[i]) + 1;
346 query.data = para_malloc(query.size);
347 p = query.data;
348 if (options) {
349 memcpy(query.data, options->data, options->size);
350 p += options->size;
351 }
352 for (i = 0; i < argc; i++) {
353 strcpy(p, argv[i]); /* OK */
354 p += strlen(argv[i]) + 1;
355 }
356 ret = send_callback_request(f, &query, result_handler,
357 private_result_data);
358 free(query.data);
359 return ret;
360 }
361
362 /**
363 * Send a callback request with an argument vector only.
364 *
365 * \param argc The same meaning as in send_option_arg_callback_request().
366 * \param argv The same meaning as in send_option_arg_callback_request().
367 * \param f The same meaning as in send_option_arg_callback_request().
368 * \param result_handler See \ref send_callback_request.
369 * \param private_result_data See \ref send_callback_request.
370 *
371 * This is similar to send_option_arg_callback_request(), but no options buffer
372 * is passed to the parent process.
373 *
374 * \return The return value of the underlying call to
375 * send_option_arg_callback_request().
376 */
377 int send_standard_callback_request(int argc, char * const * const argv,
378 afs_callback *f, callback_result_handler *result_handler,
379 void *private_result_data)
380 {
381 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
382 private_result_data);
383 }
384
385 static int action_if_pattern_matches(struct osl_row *row, void *data)
386 {
387 struct pattern_match_data *pmd = data;
388 struct osl_object name_obj;
389 const char *p, *name;
390 int i, ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
391 const char *pattern_txt = (const char *)pmd->patterns.data;
392
393 if (ret < 0)
394 return ret;
395 name = (char *)name_obj.data;
396 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
397 return 1;
398 if ((pmd->lpr && lls_num_inputs(pmd->lpr) == 0) || pmd->patterns.size == 0) {
399 if (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING) {
400 pmd->num_matches++;
401 return pmd->action(pmd->table, row, name, pmd->data);
402 }
403 }
404 p = pattern_txt;
405 i = pmd->input_skip;
406 for (;;) {
407 if (pmd->lpr) {
408 if (i >= lls_num_inputs(pmd->lpr))
409 break;
410 p = lls_input(i, pmd->lpr);
411 } else {
412 if (p >= pattern_txt + pmd->patterns.size)
413 break;
414 }
415 ret = fnmatch(p, name, pmd->fnmatch_flags);
416 if (ret != FNM_NOMATCH) {
417 if (ret != 0)
418 return -E_FNMATCH;
419 ret = pmd->action(pmd->table, row, name, pmd->data);
420 if (ret >= 0)
421 pmd->num_matches++;
422 return ret;
423
424 }
425 if (pmd->lpr)
426 i++;
427 else
428 p += strlen(p) + 1;
429 }
430 return 1;
431 }
432
433 /**
434 * Execute the given function for each matching row.
435 *
436 * \param pmd Describes what to match and how.
437 *
438 * \return Standard.
439 */
440 int for_each_matching_row(struct pattern_match_data *pmd)
441 {
442 if (pmd->pm_flags & PM_REVERSE_LOOP)
443 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
444 action_if_pattern_matches));
445 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
446 action_if_pattern_matches));
447 }
448
449 /**
450 * Compare two osl objects of string type.
451 *
452 * \param obj1 Pointer to the first object.
453 * \param obj2 Pointer to the second object.
454 *
455 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
456 * are taken into account.
457 *
458 * \return It returns an integer less than, equal to, or greater than zero if
459 * \a obj1 is found, respectively, to be less than, to match, or be greater than
460 * obj2.
461 *
462 * \sa strcmp(3), strncmp(3), osl_compare_func.
463 */
464 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
465 {
466 const char *str1 = (const char *)obj1->data;
467 const char *str2 = (const char *)obj2->data;
468 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
469 }
470
471 static int pass_afd(int fd, char *buf, size_t size)
472 {
473 struct msghdr msg = {.msg_iov = NULL};
474 struct cmsghdr *cmsg;
475 char control[255] __a_aligned(8);
476 int ret;
477 struct iovec iov;
478
479 iov.iov_base = buf;
480 iov.iov_len = size;
481
482 msg.msg_iov = &iov;
483 msg.msg_iovlen = 1;
484
485 msg.msg_control = control;
486 msg.msg_controllen = sizeof(control);
487
488 cmsg = CMSG_FIRSTHDR(&msg);
489 cmsg->cmsg_level = SOL_SOCKET;
490 cmsg->cmsg_type = SCM_RIGHTS;
491 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
492 *(int *)CMSG_DATA(cmsg) = fd;
493
494 /* Sum of the length of all control messages in the buffer */
495 msg.msg_controllen = cmsg->cmsg_len;
496 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
497 ret = sendmsg(server_socket, &msg, 0);
498 if (ret < 0) {
499 ret = -ERRNO_TO_PARA_ERROR(errno);
500 return ret;
501 }
502 return 1;
503 }
504
505 /**
506 * Pass the fd of the next audio file to the server process.
507 *
508 * This stores all information for streaming the "best" audio file in a shared
509 * memory area. The id of that area and an open file descriptor for the next
510 * audio file are passed to the server process.
511 *
512 * \return Standard.
513 *
514 * \sa open_and_update_audio_file().
515 */
516 static int open_next_audio_file(void)
517 {
518 struct audio_file_data afd;
519 int ret, shmid;
520 char buf[8];
521
522 ret = open_and_update_audio_file(&afd);
523 if (ret < 0) {
524 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
525 goto no_admissible_files;
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 write_all(server_socket, buf, 8);
545 }
546
547 /* Never fails if arg == NULL */
548 static int activate_mood_or_playlist(const 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 /**
591 * Result handler for sending data to the para_client process.
592 *
593 * \param result The data to be sent.
594 * \param band The band designator.
595 * \param private Pointer to the command context.
596 *
597 * \return The return value of the underlying call to \ref command.c::send_sb.
598 *
599 * \sa \ref callback_result_handler, \ref command.c::send_sb.
600 */
601 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
602 void *private)
603 {
604 struct command_context *cc = private;
605
606 assert(cc);
607 switch (band) {
608 case SBD_OUTPUT:
609 case SBD_DEBUG_LOG:
610 case SBD_INFO_LOG:
611 case SBD_NOTICE_LOG:
612 case SBD_WARNING_LOG:
613 case SBD_ERROR_LOG:
614 case SBD_CRIT_LOG:
615 case SBD_EMERG_LOG:
616 assert(result->size > 0);
617 return send_sb(&cc->scc, result->data, result->size, band, true);
618 case SBD_AFS_CB_FAILURE:
619 return *(int *)(result->data);
620 default:
621 return -E_BAD_BAND;
622 }
623 }
624
625 static void flush_and_free_pb(struct para_buffer *pb)
626 {
627 int ret;
628 struct afs_max_size_handler_data *amshd = pb->private_data;
629
630 if (pb->buf && pb->size > 0) {
631 ret = pass_buffer_as_shm(amshd->fd, amshd->band, pb->buf,
632 pb->offset);
633 if (ret < 0)
634 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
635 }
636 free(pb->buf);
637 }
638
639 static int com_select_callback(struct afs_callback_arg *aca)
640 {
641 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
642 const char *arg;
643 int num_admissible, ret;
644
645 ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
646 assert(ret >= 0);
647 arg = lls_input(0, aca->lpr);
648 ret = clear_score_table();
649 if (ret < 0) {
650 para_printf(&aca->pbout, "could not clear score table\n");
651 goto free_lpr;
652 }
653 if (current_play_mode == PLAY_MODE_MOOD)
654 close_current_mood();
655 else
656 playlist_close();
657 ret = activate_mood_or_playlist(arg, &num_admissible);
658 if (ret >= 0)
659 goto out;
660 /* ignore subsequent errors (but log them) */
661 para_printf(&aca->pbout, "could not activate %s\n", arg);
662 if (current_mop) {
663 int ret2;
664 para_printf(&aca->pbout, "switching back to %s\n", current_mop);
665 ret2 = activate_mood_or_playlist(current_mop, &num_admissible);
666 if (ret2 >= 0)
667 goto out;
668 para_printf(&aca->pbout, "could not reactivate %s: %s\n",
669 current_mop, para_strerror(-ret2));
670 }
671 para_printf(&aca->pbout, "activating dummy mood\n");
672 activate_mood_or_playlist(NULL, &num_admissible);
673 out:
674 para_printf(&aca->pbout, "activated %s (%d admissible files)\n",
675 current_mop? current_mop : "dummy mood", num_admissible);
676 free_lpr:
677 lls_free_parse_result(aca->lpr, cmd);
678 return ret;
679 }
680
681 static int com_select(struct command_context *cc, struct lls_parse_result *lpr)
682 {
683 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
684 char *errctx;
685 int ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
686
687 if (ret < 0) {
688 send_errctx(cc, errctx);
689 return ret;
690 }
691 return send_lls_callback_request(com_select_callback, cmd, lpr, cc);
692 }
693 EXPORT_SERVER_CMD_HANDLER(select);
694
695 static void init_admissible_files(char *arg)
696 {
697 if (activate_mood_or_playlist(arg, NULL) < 0)
698 activate_mood_or_playlist(NULL, NULL); /* always successful */
699 }
700
701 static int setup_command_socket_or_die(void)
702 {
703 int ret, socket_fd;
704 char *socket_name = conf.afs_socket_arg;
705
706 unlink(socket_name);
707 ret = create_local_socket(socket_name, 0);
708 if (ret < 0) {
709 ret = create_local_socket(socket_name,
710 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IROTH);
711 if (ret < 0) {
712 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret),
713 socket_name);
714 exit(EXIT_FAILURE);
715 }
716 }
717 socket_fd = ret;
718 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
719 socket_fd);
720 return socket_fd;
721 }
722
723 static void close_afs_tables(void)
724 {
725 int i;
726 PARA_NOTICE_LOG("closing afs_tables\n");
727 for (i = 0; i < NUM_AFS_TABLES; i++)
728 afs_tables[i].close();
729 }
730
731 static char *database_dir;
732
733 static void get_database_dir(void)
734 {
735 if (!database_dir) {
736 if (conf.afs_database_dir_given)
737 database_dir = para_strdup(conf.afs_database_dir_arg);
738 else {
739 char *home = para_homedir();
740 database_dir = make_message(
741 "%s/.paraslash/afs_database-0.4", home);
742 free(home);
743 }
744 }
745 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
746 }
747
748 static int make_database_dir(void)
749 {
750 int ret;
751
752 get_database_dir();
753 ret = para_mkdir(database_dir, 0777);
754 if (ret >= 0 || ret == -ERRNO_TO_PARA_ERROR(EEXIST))
755 return 1;
756 return ret;
757 }
758
759 static int open_afs_tables(void)
760 {
761 int i, ret;
762
763 get_database_dir();
764 PARA_NOTICE_LOG("opening %d osl tables in %s\n", NUM_AFS_TABLES,
765 database_dir);
766 for (i = 0; i < NUM_AFS_TABLES; i++) {
767 ret = afs_tables[i].open(database_dir);
768 if (ret >= 0)
769 continue;
770 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
771 para_strerror(-ret));
772 break;
773 }
774 if (ret >= 0)
775 return ret;
776 while (i)
777 afs_tables[--i].close();
778 return ret;
779 }
780
781 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
782 {
783 int signum, ret;
784
785 if (getppid() == 1) {
786 PARA_EMERG_LOG("para_server died\n");
787 goto shutdown;
788 }
789 signum = para_next_signal(&s->rfds);
790 if (signum == 0)
791 return 0;
792 if (signum == SIGHUP) {
793 close_afs_tables();
794 parse_config_or_die(1);
795 ret = open_afs_tables();
796 if (ret < 0)
797 return ret;
798 init_admissible_files(current_mop);
799 return 0;
800 }
801 PARA_EMERG_LOG("terminating on signal %d\n", signum);
802 shutdown:
803 task_notify_all(s, E_AFS_SIGNAL);
804 return -E_AFS_SIGNAL;
805 }
806
807 static void register_signal_task(struct sched *s)
808 {
809 para_sigaction(SIGPIPE, SIG_IGN);
810 signal_task = signal_init_or_die();
811 para_install_sighandler(SIGINT);
812 para_install_sighandler(SIGTERM);
813 para_install_sighandler(SIGHUP);
814
815 signal_task->task = task_register(&(struct task_info) {
816 .name = "signal",
817 .pre_select = signal_pre_select,
818 .post_select = afs_signal_post_select,
819 .context = signal_task,
820
821 }, s);
822 }
823
824 static struct list_head afs_client_list;
825
826 /** Describes one connected afs client. */
827 struct afs_client {
828 /** Position in the afs client list. */
829 struct list_head node;
830 /** The socket file descriptor for this client. */
831 int fd;
832 /** The time the client connected. */
833 struct timeval connect_time;
834 };
835
836 static void command_pre_select(struct sched *s, void *context)
837 {
838 struct command_task *ct = context;
839 struct afs_client *client;
840
841 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
842 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
843 list_for_each_entry(client, &afs_client_list, node)
844 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
845 }
846
847 /**
848 * Send data as shared memory to a file descriptor.
849 *
850 * \param fd File descriptor to send the shmid to.
851 * \param band The band designator for this data.
852 * \param buf The buffer holding the data to be sent.
853 * \param size The size of \a buf.
854 *
855 * This function creates a shared memory area large enough to hold
856 * the content given by \a buf and \a size and sends the identifier
857 * of this area to the file descriptor \a fd.
858 *
859 * It is called by the AFS max_size handler as well as directly by the AFS
860 * command callbacks to send command output to the command handlers.
861 *
862 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
863 * and positive on success.
864 */
865 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
866 {
867 int ret, shmid;
868 void *shm;
869 struct callback_result *cr;
870
871 if (size == 0)
872 assert(band != SBD_OUTPUT);
873 ret = shm_new(size + sizeof(*cr));
874 if (ret < 0)
875 return ret;
876 shmid = ret;
877 ret = shm_attach(shmid, ATTACH_RW, &shm);
878 if (ret < 0)
879 goto err;
880 cr = shm;
881 cr->result_size = size;
882 cr->band = band;
883 if (size > 0)
884 memcpy(shm + sizeof(*cr), buf, size);
885 ret = shm_detach(shm);
886 if (ret < 0)
887 goto err;
888 ret = write_all(fd, (char *)&shmid, sizeof(int));
889 if (ret >= 0)
890 return ret;
891 err:
892 if (shm_destroy(shmid) < 0)
893 PARA_ERROR_LOG("destroy result failed\n");
894 return ret;
895 }
896
897 static int call_callback(int fd, int query_shmid)
898 {
899 void *query_shm;
900 struct callback_query *cq;
901 int ret, ret2;
902 struct afs_callback_arg aca = {.fd = fd};
903
904 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
905 if (ret < 0)
906 return ret;
907 cq = query_shm;
908 aca.query.data = (char *)query_shm + sizeof(*cq);
909 aca.query.size = cq->query_size;
910 aca.pbout.max_size = shm_get_shmmax();
911 aca.pbout.max_size_handler = afs_max_size_handler;
912 aca.pbout.private_data = &(struct afs_max_size_handler_data) {
913 .fd = fd,
914 .band = SBD_OUTPUT
915 };
916 ret = cq->handler(&aca);
917 ret2 = shm_detach(query_shm);
918 if (ret2 < 0) {
919 if (ret < 0) /* ignore (but log) detach error */
920 PARA_ERROR_LOG("could not detach sma: %s\n",
921 para_strerror(-ret2));
922 else
923 ret = ret2;
924 }
925 flush_and_free_pb(&aca.pbout);
926 if (ret < 0) {
927 ret2 = pass_buffer_as_shm(fd, SBD_AFS_CB_FAILURE,
928 (const char *)&ret, sizeof(ret));
929 if (ret2 < 0)
930 PARA_ERROR_LOG("could not pass cb failure packet: %s\n",
931 para_strerror(-ret));
932 }
933 return ret;
934 }
935
936 static int execute_server_command(fd_set *rfds)
937 {
938 char buf[8];
939 size_t n;
940 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
941
942 if (ret < 0 || n == 0)
943 return ret;
944 buf[n] = '\0';
945 if (strcmp(buf, "new"))
946 return -ERRNO_TO_PARA_ERROR(EINVAL);
947 return open_next_audio_file();
948 }
949
950 /* returns 0 if no data available, 1 else */
951 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
952 {
953 uint32_t cookie;
954 int query_shmid;
955 char buf[sizeof(cookie) + sizeof(query_shmid)];
956 size_t n;
957 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
958
959 if (ret < 0)
960 goto err;
961 if (n == 0)
962 return 0;
963 if (n != sizeof(buf)) {
964 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
965 ret, (long unsigned) sizeof(buf));
966 return 1;
967 }
968 cookie = *(uint32_t *)buf;
969 if (cookie != expected_cookie) {
970 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
971 (unsigned)cookie, (unsigned)expected_cookie);
972 return 1;
973 }
974 query_shmid = *(int *)(buf + sizeof(cookie));
975 if (query_shmid < 0) {
976 PARA_WARNING_LOG("received invalid query shmid %d)\n",
977 query_shmid);
978 return 1;
979 }
980 ret = call_callback(fd, query_shmid);
981 if (ret >= 0)
982 return 1;
983 err:
984 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
985 return 1;
986 }
987
988 /** Shutdown connection if query has not arrived until this many seconds. */
989 #define AFS_CLIENT_TIMEOUT 3
990
991 static int command_post_select(struct sched *s, void *context)
992 {
993 struct command_task *ct = context;
994 struct sockaddr_un unix_addr;
995 struct afs_client *client, *tmp;
996 int fd, ret;
997
998 ret = task_get_notification(ct->task);
999 if (ret < 0)
1000 return ret;
1001 ret = execute_server_command(&s->rfds);
1002 if (ret < 0) {
1003 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1004 task_notify_all(s, -ret);
1005 return ret;
1006 }
1007 /* Check the list of connected clients. */
1008 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
1009 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
1010 if (ret == 0) { /* prevent bogus connection flooding */
1011 struct timeval diff;
1012 tv_diff(now, &client->connect_time, &diff);
1013 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
1014 continue;
1015 PARA_WARNING_LOG("connection timeout\n");
1016 }
1017 close(client->fd);
1018 list_del(&client->node);
1019 free(client);
1020 }
1021 /* Accept connections on the local socket. */
1022 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
1023 if (ret < 0)
1024 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1025 if (ret <= 0)
1026 return 0;
1027 ret = mark_fd_nonblocking(fd);
1028 if (ret < 0) {
1029 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1030 close(fd);
1031 return 0;
1032 }
1033 client = para_malloc(sizeof(*client));
1034 client->fd = fd;
1035 client->connect_time = *now;
1036 para_list_add(&client->node, &afs_client_list);
1037 return 0;
1038 }
1039
1040 static void register_command_task(uint32_t cookie, struct sched *s)
1041 {
1042 struct command_task *ct = &command_task_struct;
1043 ct->fd = setup_command_socket_or_die();
1044 ct->cookie = cookie;
1045
1046 ct->task = task_register(&(struct task_info) {
1047 .name = "afs command",
1048 .pre_select = command_pre_select,
1049 .post_select = command_post_select,
1050 .context = ct,
1051 }, s);
1052 }
1053
1054 /**
1055 * Initialize the audio file selector process.
1056 *
1057 * \param cookie The value used for "authentication".
1058 * \param socket_fd File descriptor used for communication with the server.
1059 */
1060 __noreturn void afs_init(uint32_t cookie, int socket_fd)
1061 {
1062 static struct sched s;
1063 int i, ret;
1064
1065 register_signal_task(&s);
1066 INIT_LIST_HEAD(&afs_client_list);
1067 for (i = 0; i < NUM_AFS_TABLES; i++)
1068 afs_tables[i].init(&afs_tables[i]);
1069 ret = open_afs_tables();
1070 if (ret < 0)
1071 goto out;
1072 server_socket = socket_fd;
1073 ret = mark_fd_nonblocking(server_socket);
1074 if (ret < 0)
1075 goto out_close;
1076 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1077 server_socket, (unsigned) cookie);
1078 init_admissible_files(conf.afs_initial_mode_arg);
1079 register_command_task(cookie, &s);
1080 s.default_timeout.tv_sec = 0;
1081 s.default_timeout.tv_usec = 999 * 1000;
1082 ret = write(socket_fd, "\0", 1);
1083 if (ret != 1) {
1084 if (ret == 0)
1085 errno = EINVAL;
1086 ret = -ERRNO_TO_PARA_ERROR(errno);
1087 goto out_close;
1088 }
1089 ret = schedule(&s);
1090 sched_shutdown(&s);
1091 out_close:
1092 close_afs_tables();
1093 out:
1094 if (ret < 0)
1095 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1096 exit(EXIT_FAILURE);
1097 }
1098
1099 static int com_init_callback(struct afs_callback_arg *aca)
1100 {
1101 uint32_t table_mask = *(uint32_t *)aca->query.data;
1102 int i, ret;
1103
1104 close_afs_tables();
1105 for (i = 0; i < NUM_AFS_TABLES; i++) {
1106 struct afs_table *t = &afs_tables[i];
1107
1108 if (!(table_mask & (1 << i)))
1109 continue;
1110 if (!t->create)
1111 continue;
1112 ret = t->create(database_dir);
1113 if (ret < 0) {
1114 para_printf(&aca->pbout, "cannot create table %s\n",
1115 t->name);
1116 goto out;
1117 }
1118 para_printf(&aca->pbout, "successfully created %s table\n",
1119 t->name);
1120 }
1121 ret = open_afs_tables();
1122 if (ret < 0)
1123 para_printf(&aca->pbout, "cannot open afs tables\n");
1124 out:
1125 return ret;
1126 }
1127
1128 static int com_init(struct command_context *cc, struct lls_parse_result *lpr)
1129 {
1130 int i, j, ret;
1131 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1132 struct osl_object query = {.data = &table_mask,
1133 .size = sizeof(table_mask)};
1134 unsigned num_inputs = lls_num_inputs(lpr);
1135
1136 ret = make_database_dir();
1137 if (ret < 0)
1138 return ret;
1139 if (num_inputs > 0) {
1140 table_mask = 0;
1141 for (i = 0; i < num_inputs; i++) {
1142 for (j = 0; j < NUM_AFS_TABLES; j++) {
1143 struct afs_table *t = &afs_tables[j];
1144
1145 if (strcmp(lls_input(i, lpr), t->name))
1146 continue;
1147 table_mask |= (1 << j);
1148 break;
1149 }
1150 if (j == NUM_AFS_TABLES)
1151 return -E_BAD_TABLE_NAME;
1152 }
1153 }
1154 return send_callback_request(com_init_callback, &query,
1155 afs_cb_result_handler, cc);
1156 }
1157 EXPORT_SERVER_CMD_HANDLER(init);
1158
1159 static int com_check(struct command_context *cc, struct lls_parse_result *lpr)
1160 {
1161 const struct lls_opt_result *r_a = SERVER_CMD_OPT_RESULT(CHECK, AFT, lpr);
1162 const struct lls_opt_result *r_A = SERVER_CMD_OPT_RESULT(CHECK, ATTRIBUTE, lpr);
1163 const struct lls_opt_result *r_m = SERVER_CMD_OPT_RESULT(CHECK, MOOD, lpr);
1164 const struct lls_opt_result *r_p = SERVER_CMD_OPT_RESULT(CHECK, PLAYLIST, lpr);
1165 bool noopt = !lls_opt_given(r_a) && !lls_opt_given(r_A)
1166 && !lls_opt_given(r_m) && !lls_opt_given(r_p);
1167 int ret;
1168
1169 if (noopt || lls_opt_given(r_a)) {
1170 ret = send_callback_request(aft_check_callback, NULL,
1171 afs_cb_result_handler, cc);
1172 if (ret < 0)
1173 return ret;
1174 }
1175 if (noopt || lls_opt_given(r_A)) {
1176 ret = send_callback_request(attribute_check_callback, NULL,
1177 afs_cb_result_handler, cc);
1178 if (ret < 0)
1179 return ret;
1180 }
1181 if (noopt || lls_opt_given(r_p)) {
1182 ret = send_callback_request(playlist_check_callback,
1183 NULL, afs_cb_result_handler, cc);
1184 if (ret < 0)
1185 return ret;
1186 }
1187 if (noopt || lls_opt_given(r_m)) {
1188 ret = send_callback_request(mood_check_callback, NULL,
1189 afs_cb_result_handler, cc);
1190 if (ret < 0)
1191 return ret;
1192 }
1193 return 1;
1194 }
1195 EXPORT_SERVER_CMD_HANDLER(check);
1196
1197 /**
1198 * The afs event dispatcher.
1199 *
1200 * \param event Type of the event.
1201 * \param pb May be \p NULL.
1202 * \param data Type depends on \a event.
1203 *
1204 * This function calls each table event handler, passing \a pb and \a data
1205 * verbatim. It's up to the handlers to interpret the \a data pointer. If a
1206 * handler returns negative, the loop is aborted.
1207 *
1208 * \return The (negative) error code of the first handler that failed, or non-negative
1209 * if all handlers succeeded.
1210 */
1211 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
1212 void *data)
1213 {
1214 int i, ret;
1215
1216 for (i = 0; i < NUM_AFS_TABLES; i++) {
1217 struct afs_table *t = &afs_tables[i];
1218 if (!t->event_handler)
1219 continue;
1220 ret = t->event_handler(event, pb, data);
1221 if (ret < 0) {
1222 PARA_CRIT_LOG("table %s, event %u: %s\n", t->name,
1223 event, para_strerror(-ret));
1224 return ret;
1225 }
1226 }
1227 return 1;
1228 }
1229
1230 /**
1231 * Dummy event handler for the images table.
1232 *
1233 * \param event Unused.
1234 * \param pb Unused.
1235 * \param data Unused.
1236 *
1237 * \return The images table does not honor events, so this handler always
1238 * returns success.
1239 */
1240 __a_const int images_event_handler(__a_unused enum afs_events event,
1241 __a_unused struct para_buffer *pb, __a_unused void *data)
1242 {
1243 return 1;
1244 }
1245
1246 /**
1247 * Dummy event handler for the lyrics table.
1248 *
1249 * \param event Unused.
1250 * \param pb Unused.
1251 * \param data Unused.
1252 *
1253 * \return The lyrics table does not honor events, so this handler always
1254 * returns success.
1255 */
1256 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1257 __a_unused struct para_buffer *pb, __a_unused void *data)
1258 {
1259 return 1;
1260 }