server: Convert com_check() 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 char *arg = aca->query.data;
642 int num_admissible, ret;
643
644 ret = clear_score_table();
645 if (ret < 0) {
646 para_printf(&aca->pbout, "could not clear score table: %s\n",
647 para_strerror(-ret));
648 return ret;
649 }
650 if (current_play_mode == PLAY_MODE_MOOD)
651 close_current_mood();
652 else
653 playlist_close();
654 ret = activate_mood_or_playlist(arg, &num_admissible);
655 if (ret >= 0)
656 goto out;
657 /* ignore subsequent errors (but log them) */
658 para_printf(&aca->pbout, "could not activate %s\n", arg);
659 if (current_mop) {
660 int ret2;
661 para_printf(&aca->pbout, "switching back to %s\n", current_mop);
662 ret2 = activate_mood_or_playlist(current_mop, &num_admissible);
663 if (ret2 >= 0)
664 goto out;
665 para_printf(&aca->pbout, "could not reactivate %s: %s\n",
666 current_mop, para_strerror(-ret2));
667 }
668 para_printf(&aca->pbout, "activating dummy mood\n");
669 activate_mood_or_playlist(NULL, &num_admissible);
670 out:
671 para_printf(&aca->pbout, "activated %s (%d admissible files)\n",
672 current_mop? current_mop : "dummy mood", num_admissible);
673 return ret;
674 }
675
676 int com_select(struct command_context *cc)
677 {
678 struct osl_object query;
679
680 if (cc->argc != 2)
681 return -E_AFS_SYNTAX;
682 query.data = cc->argv[1];
683 query.size = strlen(cc->argv[1]) + 1;
684 return send_callback_request(com_select_callback, &query,
685 &afs_cb_result_handler, cc);
686 }
687
688 static void init_admissible_files(char *arg)
689 {
690 if (activate_mood_or_playlist(arg, NULL) < 0)
691 activate_mood_or_playlist(NULL, NULL); /* always successful */
692 }
693
694 static int setup_command_socket_or_die(void)
695 {
696 int ret, socket_fd;
697 char *socket_name = conf.afs_socket_arg;
698
699 unlink(socket_name);
700 ret = create_local_socket(socket_name, 0);
701 if (ret < 0) {
702 ret = create_local_socket(socket_name,
703 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IROTH);
704 if (ret < 0) {
705 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret),
706 socket_name);
707 exit(EXIT_FAILURE);
708 }
709 }
710 socket_fd = ret;
711 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
712 socket_fd);
713 return socket_fd;
714 }
715
716 static void close_afs_tables(void)
717 {
718 int i;
719 PARA_NOTICE_LOG("closing afs_tables\n");
720 for (i = 0; i < NUM_AFS_TABLES; i++)
721 afs_tables[i].close();
722 }
723
724 static char *database_dir;
725
726 static void get_database_dir(void)
727 {
728 if (!database_dir) {
729 if (conf.afs_database_dir_given)
730 database_dir = para_strdup(conf.afs_database_dir_arg);
731 else {
732 char *home = para_homedir();
733 database_dir = make_message(
734 "%s/.paraslash/afs_database-0.4", home);
735 free(home);
736 }
737 }
738 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
739 }
740
741 static int make_database_dir(void)
742 {
743 int ret;
744
745 get_database_dir();
746 ret = para_mkdir(database_dir, 0777);
747 if (ret >= 0 || ret == -ERRNO_TO_PARA_ERROR(EEXIST))
748 return 1;
749 return ret;
750 }
751
752 static int open_afs_tables(void)
753 {
754 int i, ret;
755
756 get_database_dir();
757 PARA_NOTICE_LOG("opening %d osl tables in %s\n", NUM_AFS_TABLES,
758 database_dir);
759 for (i = 0; i < NUM_AFS_TABLES; i++) {
760 ret = afs_tables[i].open(database_dir);
761 if (ret >= 0)
762 continue;
763 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
764 para_strerror(-ret));
765 break;
766 }
767 if (ret >= 0)
768 return ret;
769 while (i)
770 afs_tables[--i].close();
771 return ret;
772 }
773
774 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
775 {
776 int signum, ret;
777
778 if (getppid() == 1) {
779 PARA_EMERG_LOG("para_server died\n");
780 goto shutdown;
781 }
782 signum = para_next_signal(&s->rfds);
783 if (signum == 0)
784 return 0;
785 if (signum == SIGHUP) {
786 close_afs_tables();
787 parse_config_or_die(1);
788 ret = open_afs_tables();
789 if (ret < 0)
790 return ret;
791 init_admissible_files(current_mop);
792 return 0;
793 }
794 PARA_EMERG_LOG("terminating on signal %d\n", signum);
795 shutdown:
796 task_notify_all(s, E_AFS_SIGNAL);
797 return -E_AFS_SIGNAL;
798 }
799
800 static void register_signal_task(struct sched *s)
801 {
802 para_sigaction(SIGPIPE, SIG_IGN);
803 signal_task = signal_init_or_die();
804 para_install_sighandler(SIGINT);
805 para_install_sighandler(SIGTERM);
806 para_install_sighandler(SIGHUP);
807
808 signal_task->task = task_register(&(struct task_info) {
809 .name = "signal",
810 .pre_select = signal_pre_select,
811 .post_select = afs_signal_post_select,
812 .context = signal_task,
813
814 }, s);
815 }
816
817 static struct list_head afs_client_list;
818
819 /** Describes one connected afs client. */
820 struct afs_client {
821 /** Position in the afs client list. */
822 struct list_head node;
823 /** The socket file descriptor for this client. */
824 int fd;
825 /** The time the client connected. */
826 struct timeval connect_time;
827 };
828
829 static void command_pre_select(struct sched *s, void *context)
830 {
831 struct command_task *ct = context;
832 struct afs_client *client;
833
834 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
835 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
836 list_for_each_entry(client, &afs_client_list, node)
837 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
838 }
839
840 /**
841 * Send data as shared memory to a file descriptor.
842 *
843 * \param fd File descriptor to send the shmid to.
844 * \param band The band designator for this data.
845 * \param buf The buffer holding the data to be sent.
846 * \param size The size of \a buf.
847 *
848 * This function creates a shared memory area large enough to hold
849 * the content given by \a buf and \a size and sends the identifier
850 * of this area to the file descriptor \a fd.
851 *
852 * It is called by the AFS max_size handler as well as directly by the AFS
853 * command callbacks to send command output to the command handlers.
854 *
855 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
856 * and positive on success.
857 */
858 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
859 {
860 int ret, shmid;
861 void *shm;
862 struct callback_result *cr;
863
864 if (size == 0)
865 assert(band != SBD_OUTPUT);
866 ret = shm_new(size + sizeof(*cr));
867 if (ret < 0)
868 return ret;
869 shmid = ret;
870 ret = shm_attach(shmid, ATTACH_RW, &shm);
871 if (ret < 0)
872 goto err;
873 cr = shm;
874 cr->result_size = size;
875 cr->band = band;
876 if (size > 0)
877 memcpy(shm + sizeof(*cr), buf, size);
878 ret = shm_detach(shm);
879 if (ret < 0)
880 goto err;
881 ret = write_all(fd, (char *)&shmid, sizeof(int));
882 if (ret >= 0)
883 return ret;
884 err:
885 if (shm_destroy(shmid) < 0)
886 PARA_ERROR_LOG("destroy result failed\n");
887 return ret;
888 }
889
890 static int call_callback(int fd, int query_shmid)
891 {
892 void *query_shm;
893 struct callback_query *cq;
894 int ret, ret2;
895 struct afs_callback_arg aca = {.fd = fd};
896
897 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
898 if (ret < 0)
899 return ret;
900 cq = query_shm;
901 aca.query.data = (char *)query_shm + sizeof(*cq);
902 aca.query.size = cq->query_size;
903 aca.pbout.max_size = shm_get_shmmax();
904 aca.pbout.max_size_handler = afs_max_size_handler;
905 aca.pbout.private_data = &(struct afs_max_size_handler_data) {
906 .fd = fd,
907 .band = SBD_OUTPUT
908 };
909 ret = cq->handler(&aca);
910 ret2 = shm_detach(query_shm);
911 if (ret2 < 0) {
912 if (ret < 0) /* ignore (but log) detach error */
913 PARA_ERROR_LOG("could not detach sma: %s\n",
914 para_strerror(-ret2));
915 else
916 ret = ret2;
917 }
918 flush_and_free_pb(&aca.pbout);
919 if (ret < 0) {
920 ret2 = pass_buffer_as_shm(fd, SBD_AFS_CB_FAILURE,
921 (const char *)&ret, sizeof(ret));
922 if (ret2 < 0)
923 PARA_ERROR_LOG("could not pass cb failure packet: %s\n",
924 para_strerror(-ret));
925 }
926 return ret;
927 }
928
929 static int execute_server_command(fd_set *rfds)
930 {
931 char buf[8];
932 size_t n;
933 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
934
935 if (ret < 0 || n == 0)
936 return ret;
937 buf[n] = '\0';
938 if (strcmp(buf, "new"))
939 return -ERRNO_TO_PARA_ERROR(EINVAL);
940 return open_next_audio_file();
941 }
942
943 /* returns 0 if no data available, 1 else */
944 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
945 {
946 uint32_t cookie;
947 int query_shmid;
948 char buf[sizeof(cookie) + sizeof(query_shmid)];
949 size_t n;
950 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
951
952 if (ret < 0)
953 goto err;
954 if (n == 0)
955 return 0;
956 if (n != sizeof(buf)) {
957 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
958 ret, (long unsigned) sizeof(buf));
959 return 1;
960 }
961 cookie = *(uint32_t *)buf;
962 if (cookie != expected_cookie) {
963 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
964 (unsigned)cookie, (unsigned)expected_cookie);
965 return 1;
966 }
967 query_shmid = *(int *)(buf + sizeof(cookie));
968 if (query_shmid < 0) {
969 PARA_WARNING_LOG("received invalid query shmid %d)\n",
970 query_shmid);
971 return 1;
972 }
973 ret = call_callback(fd, query_shmid);
974 if (ret >= 0)
975 return 1;
976 err:
977 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
978 return 1;
979 }
980
981 /** Shutdown connection if query has not arrived until this many seconds. */
982 #define AFS_CLIENT_TIMEOUT 3
983
984 static int command_post_select(struct sched *s, void *context)
985 {
986 struct command_task *ct = context;
987 struct sockaddr_un unix_addr;
988 struct afs_client *client, *tmp;
989 int fd, ret;
990
991 ret = task_get_notification(ct->task);
992 if (ret < 0)
993 return ret;
994 ret = execute_server_command(&s->rfds);
995 if (ret < 0) {
996 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
997 task_notify_all(s, -ret);
998 return ret;
999 }
1000 /* Check the list of connected clients. */
1001 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
1002 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
1003 if (ret == 0) { /* prevent bogus connection flooding */
1004 struct timeval diff;
1005 tv_diff(now, &client->connect_time, &diff);
1006 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
1007 continue;
1008 PARA_WARNING_LOG("connection timeout\n");
1009 }
1010 close(client->fd);
1011 list_del(&client->node);
1012 free(client);
1013 }
1014 /* Accept connections on the local socket. */
1015 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
1016 if (ret < 0)
1017 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1018 if (ret <= 0)
1019 return 0;
1020 ret = mark_fd_nonblocking(fd);
1021 if (ret < 0) {
1022 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1023 close(fd);
1024 return 0;
1025 }
1026 client = para_malloc(sizeof(*client));
1027 client->fd = fd;
1028 client->connect_time = *now;
1029 para_list_add(&client->node, &afs_client_list);
1030 return 0;
1031 }
1032
1033 static void register_command_task(uint32_t cookie, struct sched *s)
1034 {
1035 struct command_task *ct = &command_task_struct;
1036 ct->fd = setup_command_socket_or_die();
1037 ct->cookie = cookie;
1038
1039 ct->task = task_register(&(struct task_info) {
1040 .name = "afs command",
1041 .pre_select = command_pre_select,
1042 .post_select = command_post_select,
1043 .context = ct,
1044 }, s);
1045 }
1046
1047 /**
1048 * Initialize the audio file selector process.
1049 *
1050 * \param cookie The value used for "authentication".
1051 * \param socket_fd File descriptor used for communication with the server.
1052 */
1053 __noreturn void afs_init(uint32_t cookie, int socket_fd)
1054 {
1055 static struct sched s;
1056 int i, ret;
1057
1058 register_signal_task(&s);
1059 INIT_LIST_HEAD(&afs_client_list);
1060 for (i = 0; i < NUM_AFS_TABLES; i++)
1061 afs_tables[i].init(&afs_tables[i]);
1062 ret = open_afs_tables();
1063 if (ret < 0)
1064 goto out;
1065 server_socket = socket_fd;
1066 ret = mark_fd_nonblocking(server_socket);
1067 if (ret < 0)
1068 goto out_close;
1069 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1070 server_socket, (unsigned) cookie);
1071 init_admissible_files(conf.afs_initial_mode_arg);
1072 register_command_task(cookie, &s);
1073 s.default_timeout.tv_sec = 0;
1074 s.default_timeout.tv_usec = 999 * 1000;
1075 ret = write(socket_fd, "\0", 1);
1076 if (ret != 1) {
1077 if (ret == 0)
1078 errno = EINVAL;
1079 ret = -ERRNO_TO_PARA_ERROR(errno);
1080 goto out_close;
1081 }
1082 ret = schedule(&s);
1083 sched_shutdown(&s);
1084 out_close:
1085 close_afs_tables();
1086 out:
1087 if (ret < 0)
1088 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1089 exit(EXIT_FAILURE);
1090 }
1091
1092 static int com_init_callback(struct afs_callback_arg *aca)
1093 {
1094 uint32_t table_mask = *(uint32_t *)aca->query.data;
1095 int i, ret;
1096
1097 close_afs_tables();
1098 for (i = 0; i < NUM_AFS_TABLES; i++) {
1099 struct afs_table *t = &afs_tables[i];
1100
1101 if (!(table_mask & (1 << i)))
1102 continue;
1103 if (!t->create)
1104 continue;
1105 ret = t->create(database_dir);
1106 if (ret < 0) {
1107 para_printf(&aca->pbout, "cannot create table %s\n",
1108 t->name);
1109 goto out;
1110 }
1111 para_printf(&aca->pbout, "successfully created %s table\n",
1112 t->name);
1113 }
1114 ret = open_afs_tables();
1115 if (ret < 0)
1116 para_printf(&aca->pbout, "cannot open afs tables\n");
1117 out:
1118 return ret;
1119 }
1120
1121 static int com_init(struct command_context *cc, struct lls_parse_result *lpr)
1122 {
1123 int i, j, ret;
1124 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1125 struct osl_object query = {.data = &table_mask,
1126 .size = sizeof(table_mask)};
1127 unsigned num_inputs = lls_num_inputs(lpr);
1128
1129 ret = make_database_dir();
1130 if (ret < 0)
1131 return ret;
1132 if (num_inputs > 0) {
1133 table_mask = 0;
1134 for (i = 0; i < num_inputs; i++) {
1135 for (j = 0; j < NUM_AFS_TABLES; j++) {
1136 struct afs_table *t = &afs_tables[j];
1137
1138 if (strcmp(lls_input(i, lpr), t->name))
1139 continue;
1140 table_mask |= (1 << j);
1141 break;
1142 }
1143 if (j == NUM_AFS_TABLES)
1144 return -E_BAD_TABLE_NAME;
1145 }
1146 }
1147 return send_callback_request(com_init_callback, &query,
1148 afs_cb_result_handler, cc);
1149 }
1150 EXPORT_SERVER_CMD_HANDLER(init);
1151
1152 static int com_check(struct command_context *cc, struct lls_parse_result *lpr)
1153 {
1154 const struct lls_opt_result *r_a = SERVER_CMD_OPT_RESULT(CHECK, AFT, lpr);
1155 const struct lls_opt_result *r_A = SERVER_CMD_OPT_RESULT(CHECK, ATTRIBUTE, lpr);
1156 const struct lls_opt_result *r_m = SERVER_CMD_OPT_RESULT(CHECK, MOOD, lpr);
1157 const struct lls_opt_result *r_p = SERVER_CMD_OPT_RESULT(CHECK, PLAYLIST, lpr);
1158 bool noopt = !lls_opt_given(r_a) && !lls_opt_given(r_A)
1159 && !lls_opt_given(r_m) && !lls_opt_given(r_p);
1160 int ret;
1161
1162 if (noopt || lls_opt_given(r_a)) {
1163 ret = send_callback_request(aft_check_callback, NULL,
1164 afs_cb_result_handler, cc);
1165 if (ret < 0)
1166 return ret;
1167 }
1168 if (noopt || lls_opt_given(r_A)) {
1169 ret = send_callback_request(attribute_check_callback, NULL,
1170 afs_cb_result_handler, cc);
1171 if (ret < 0)
1172 return ret;
1173 }
1174 if (noopt || lls_opt_given(r_p)) {
1175 ret = send_callback_request(playlist_check_callback,
1176 NULL, afs_cb_result_handler, cc);
1177 if (ret < 0)
1178 return ret;
1179 }
1180 if (noopt || lls_opt_given(r_m)) {
1181 ret = send_callback_request(mood_check_callback, NULL,
1182 afs_cb_result_handler, cc);
1183 if (ret < 0)
1184 return ret;
1185 }
1186 return 1;
1187 }
1188 EXPORT_SERVER_CMD_HANDLER(check);
1189
1190 /**
1191 * The afs event dispatcher.
1192 *
1193 * \param event Type of the event.
1194 * \param pb May be \p NULL.
1195 * \param data Type depends on \a event.
1196 *
1197 * This function calls each table event handler, passing \a pb and \a data
1198 * verbatim. It's up to the handlers to interpret the \a data pointer. If a
1199 * handler returns negative, the loop is aborted.
1200 *
1201 * \return The (negative) error code of the first handler that failed, or non-negative
1202 * if all handlers succeeded.
1203 */
1204 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
1205 void *data)
1206 {
1207 int i, ret;
1208
1209 for (i = 0; i < NUM_AFS_TABLES; i++) {
1210 struct afs_table *t = &afs_tables[i];
1211 if (!t->event_handler)
1212 continue;
1213 ret = t->event_handler(event, pb, data);
1214 if (ret < 0) {
1215 PARA_CRIT_LOG("table %s, event %u: %s\n", t->name,
1216 event, para_strerror(-ret));
1217 return ret;
1218 }
1219 }
1220 return 1;
1221 }
1222
1223 /**
1224 * Dummy event handler for the images table.
1225 *
1226 * \param event Unused.
1227 * \param pb Unused.
1228 * \param data Unused.
1229 *
1230 * \return The images table does not honor events, so this handler always
1231 * returns success.
1232 */
1233 __a_const int images_event_handler(__a_unused enum afs_events event,
1234 __a_unused struct para_buffer *pb, __a_unused void *data)
1235 {
1236 return 1;
1237 }
1238
1239 /**
1240 * Dummy event handler for the lyrics table.
1241 *
1242 * \param event Unused.
1243 * \param pb Unused.
1244 * \param data Unused.
1245 *
1246 * \return The lyrics table does not honor events, so this handler always
1247 * returns success.
1248 */
1249 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1250 __a_unused struct para_buffer *pb, __a_unused void *data)
1251 {
1252 return 1;
1253 }