Merge branch 'maint'
[paraslash.git] / afs.c
1 /* Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
2
3 /** \file afs.c Paraslash's audio file selector. */
4
5 #include <netinet/in.h>
6 #include <sys/socket.h>
7 #include <regex.h>
8 #include <signal.h>
9 #include <fnmatch.h>
10 #include <osl.h>
11 #include <lopsub.h>
12 #include <arpa/inet.h>
13 #include <sys/un.h>
14 #include <netdb.h>
15 #include <lopsub.h>
16
17 #include "server.lsg.h"
18 #include "server_cmd.lsg.h"
19 #include "para.h"
20 #include "error.h"
21 #include "crypt.h"
22 #include "string.h"
23 #include "afh.h"
24 #include "afs.h"
25 #include "server.h"
26 #include "net.h"
27 #include "ipc.h"
28 #include "list.h"
29 #include "sched.h"
30 #include "fd.h"
31 #include "signal.h"
32 #include "mood.h"
33 #include "sideband.h"
34 #include "command.h"
35
36 /** The osl tables used by afs. \sa \ref blob.c. */
37 enum afs_table_num {
38 /** Contains audio file information. See \ref aft.c. */
39 TBLNUM_AUDIO_FILES,
40 /** The table for the paraslash attributes. See \ref attribute.c. */
41 TBLNUM_ATTRIBUTES,
42 /**
43 * Paraslash's scoring system is based on Gaussian normal
44 * distributions, and the relevant data is stored in the rbtrees of an
45 * osl table containing only volatile columns. See \ref score.c for
46 * details.
47 */
48 TBLNUM_SCORES,
49 /**
50 * A standard blob table containing the mood definitions. For details
51 * see \ref mood.c.
52 */
53 TBLNUM_MOODS,
54 /** A blob table containing lyrics on a per-song basis. */
55 TBLNUM_LYRICS,
56 /** Another blob table for images (for example album cover art). */
57 TBLNUM_IMAGES,
58 /** Yet another blob table for storing standard playlists. */
59 TBLNUM_PLAYLIST,
60 /** How many tables are in use? */
61 NUM_AFS_TABLES
62 };
63
64 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
65 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
66 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
67 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
68 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
69 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
70 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
71 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
72 };
73
74 struct command_task {
75 /** The file descriptor for the local socket. */
76 int fd;
77 /**
78 * Value sent by the command handlers to identify themselves as
79 * children of the running para_server.
80 */
81 uint32_t cookie;
82 /** The associated task structure. */
83 struct task *task;
84 };
85
86 extern int mmd_mutex;
87 extern struct misc_meta_data *mmd;
88
89 static int server_socket;
90 static struct command_task command_task_struct;
91 static struct signal_task *signal_task;
92
93 static enum play_mode current_play_mode;
94 static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
95
96 /**
97 * A random number used to "authenticate" the connection.
98 *
99 * para_server picks this number by random before it forks the afs process. The
100 * command handlers know this number as well and write it to the afs socket,
101 * together with the id of the shared memory area which contains the payload of
102 * the afs command. A local process has to know this number to abuse the afs
103 * service provided by the local socket.
104 */
105 extern uint32_t afs_socket_cookie;
106
107 /**
108 * Struct to let command handlers execute a callback in afs context.
109 *
110 * Commands that need to change the state of afs can't change the relevant data
111 * structures directly because commands are executed in a child process, i.e.
112 * they get their own virtual address space.
113 *
114 * This structure is used by \p send_callback_request() (executed from handler
115 * context) in order to let the afs process call the specified function. An
116 * instance of that structure is written to a shared memory area together with
117 * the arguments to the callback function. The identifier of the shared memory
118 * area is written to the command socket.
119 *
120 * The afs process accepts connections on the command socket and reads the
121 * shared memory id, attaches the corresponding area, calls the given handler to
122 * perform the desired action and to optionally compute a result.
123 *
124 * The result and a \p callback_result structure is then written to another
125 * shared memory area. The identifier for that area is written to the handler's
126 * command socket, so that the handler process can read the id, attach the
127 * shared memory area and use the result.
128 *
129 * \sa \ref struct callback_result.
130 */
131 struct callback_query {
132 /** The function to be called. */
133 afs_callback *handler;
134 /** The number of bytes of the query */
135 size_t query_size;
136 };
137
138 /**
139 * Structure embedded in the result of a callback.
140 *
141 * If the callback produced a result, an instance of that structure is embedded
142 * into the shared memory area holding the result, mainly to let the command
143 * handler know the size of the result.
144 *
145 * \sa \ref struct callback_query.
146 */
147 struct callback_result {
148 /** The number of bytes of the result. */
149 size_t result_size;
150 /** The band designator (loglevel for the result). */
151 uint8_t band;
152 };
153
154 static int dispatch_result(int result_shmid, callback_result_handler *handler,
155 void *private_result_data)
156 {
157 struct osl_object result;
158 void *result_shm;
159 /* must attach r/w as result.data might get encrypted in-place. */
160 int ret2, ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
161 struct callback_result *cr = result_shm;
162
163 if (ret < 0) {
164 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
165 return ret;
166 }
167 result.size = cr->result_size;
168 result.data = result_shm + sizeof(*cr);
169 assert(handler);
170 ret = handler(&result, cr->band, private_result_data);
171 ret2 = shm_detach(result_shm);
172 if (ret2 < 0) {
173 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
174 if (ret >= 0)
175 ret = ret2;
176 }
177 return ret;
178 }
179
180 /**
181 * Ask the afs process to call a given function.
182 *
183 * \param f The function to be called.
184 * \param query Pointer to arbitrary data for the callback.
185 * \param result_handler Called for each shm area sent by the callback.
186 * \param private_result_data Passed verbatim to \a result_handler.
187 *
188 * This function creates a socket for communication with the afs process and a
189 * shared memory area (sma) to which the buffer pointed to by \a query is
190 * copied. It then notifies the afs process that the callback function \a f
191 * should be executed by sending the shared memory identifier (shmid) to the
192 * socket.
193 *
194 * If the callback produces a result, it sends any number of shared memory
195 * identifiers back via the socket. For each such identifier received, \a
196 * result_handler is called. The contents of the sma identified by the received
197 * shmid are passed to that function as an osl object. The private_result_data
198 * pointer is passed as the second argument to \a result_handler.
199 *
200 * \return Number of shared memory areas dispatched on success, negative on
201 * errors.
202 */
203 int send_callback_request(afs_callback *f, struct osl_object *query,
204 callback_result_handler *result_handler,
205 void *private_result_data)
206 {
207 struct callback_query *cq;
208 int ret, fd = -1, query_shmid, result_shmid;
209 void *query_shm;
210 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
211 size_t query_shm_size = sizeof(*cq);
212 int dispatch_error = 0, num_dispatched = 0;
213
214 if (query)
215 query_shm_size += query->size;
216 ret = shm_new(query_shm_size);
217 if (ret < 0)
218 return ret;
219 query_shmid = ret;
220 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
221 if (ret < 0)
222 goto out;
223 cq = query_shm;
224 cq->handler = f;
225 cq->query_size = query_shm_size - sizeof(*cq);
226
227 if (query)
228 memcpy(query_shm + sizeof(*cq), query->data, query->size);
229 ret = shm_detach(query_shm);
230 if (ret < 0)
231 goto out;
232
233 *(uint32_t *)buf = afs_socket_cookie;
234 *(int *)(buf + sizeof(afs_socket_cookie)) = query_shmid;
235
236 ret = connect_local_socket(OPT_STRING_VAL(AFS_SOCKET));
237 if (ret < 0)
238 goto out;
239 fd = ret;
240 ret = write_all(fd, buf, sizeof(buf));
241 if (ret < 0)
242 goto out;
243 /*
244 * Read all shmids from afs.
245 *
246 * Even if the dispatcher returns an error we _must_ continue to read
247 * shmids from fd so that we can destroy all shared memory areas that
248 * have been created for us by the afs process.
249 */
250 for (;;) {
251 ret = recv_bin_buffer(fd, buf, sizeof(int));
252 if (ret <= 0)
253 goto out;
254 assert(ret == sizeof(int));
255 ret = *(int *) buf;
256 assert(ret > 0);
257 result_shmid = ret;
258 ret = dispatch_result(result_shmid, result_handler,
259 private_result_data);
260 if (ret < 0 && dispatch_error >= 0)
261 dispatch_error = ret;
262 ret = shm_destroy(result_shmid);
263 if (ret < 0)
264 PARA_CRIT_LOG("destroy result failed: %s\n",
265 para_strerror(-ret));
266 num_dispatched++;
267 }
268 out:
269 if (shm_destroy(query_shmid) < 0)
270 PARA_CRIT_LOG("shm destroy error\n");
271 if (fd >= 0)
272 close(fd);
273 if (dispatch_error < 0)
274 return dispatch_error;
275 if (ret < 0)
276 return ret;
277 return num_dispatched;
278 }
279
280 /**
281 * Wrapper for send_callback_request() which passes a lopsub parse result.
282 *
283 * \param f The callback function.
284 * \param cmd Needed for (de-)serialization.
285 * \param lpr Must match cmd.
286 * \param private_result_data Passed to send_callback_request().
287 *
288 * This function serializes the parse result given by the lpr pointer into a
289 * buffer. The buffer is sent as the query to the afs process with the callback
290 * mechanism.
291 *
292 * \return The return value of the underlying call to send_callback_request().
293 */
294 int send_lls_callback_request(afs_callback *f,
295 const struct lls_command * const cmd,
296 struct lls_parse_result *lpr, void *private_result_data)
297 {
298 struct osl_object query;
299 char *buf = NULL;
300 int ret = lls_serialize_parse_result(lpr, cmd, &buf, &query.size);
301
302 assert(ret >= 0);
303 query.data = buf;
304 ret = send_callback_request(f, &query, afs_cb_result_handler,
305 private_result_data);
306 free(buf);
307 return ret;
308 }
309
310 static int action_if_pattern_matches(struct osl_row *row, void *data)
311 {
312 struct pattern_match_data *pmd = data;
313 struct osl_object name_obj;
314 const char *p, *name;
315 int i, ret;
316
317 ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num,
318 &name_obj));
319 if (ret < 0)
320 return ret;
321 name = (char *)name_obj.data;
322 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
323 return 1;
324 if (lls_num_inputs(pmd->lpr) == 0) {
325 if (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING) {
326 pmd->num_matches++;
327 return pmd->action(pmd->table, row, name, pmd->data);
328 }
329 }
330 i = pmd->input_skip;
331 for (;;) {
332 if (i >= lls_num_inputs(pmd->lpr))
333 break;
334 p = lls_input(i, pmd->lpr);
335 ret = fnmatch(p, name, pmd->fnmatch_flags);
336 if (ret != FNM_NOMATCH) {
337 if (ret != 0)
338 return -E_FNMATCH;
339 ret = pmd->action(pmd->table, row, name, pmd->data);
340 if (ret >= 0)
341 pmd->num_matches++;
342 return ret;
343
344 }
345 i++;
346 }
347 return 1;
348 }
349
350 /**
351 * Execute the given function for each matching row.
352 *
353 * \param pmd Describes what to match and how.
354 *
355 * \return Standard.
356 */
357 int for_each_matching_row(struct pattern_match_data *pmd)
358 {
359 if (pmd->pm_flags & PM_REVERSE_LOOP)
360 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
361 action_if_pattern_matches));
362 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
363 action_if_pattern_matches));
364 }
365
366 /**
367 * Compare two osl objects of string type.
368 *
369 * \param obj1 Pointer to the first object.
370 * \param obj2 Pointer to the second object.
371 *
372 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
373 * are taken into account.
374 *
375 * \return It returns an integer less than, equal to, or greater than zero if
376 * \a obj1 is found, respectively, to be less than, to match, or be greater than
377 * obj2.
378 *
379 * \sa strcmp(3), strncmp(3).
380 */
381 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
382 {
383 const char *str1 = (const char *)obj1->data;
384 const char *str2 = (const char *)obj2->data;
385 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
386 }
387
388 static int pass_afd(int fd, char *buf, size_t size)
389 {
390 struct msghdr msg = {.msg_iov = NULL};
391 struct cmsghdr *cmsg;
392 char control[255] __a_aligned(8);
393 int ret;
394 struct iovec iov;
395
396 iov.iov_base = buf;
397 iov.iov_len = size;
398
399 msg.msg_iov = &iov;
400 msg.msg_iovlen = 1;
401
402 msg.msg_control = control;
403 msg.msg_controllen = sizeof(control);
404
405 cmsg = CMSG_FIRSTHDR(&msg);
406 cmsg->cmsg_level = SOL_SOCKET;
407 cmsg->cmsg_type = SCM_RIGHTS;
408 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
409 *(int *)CMSG_DATA(cmsg) = fd;
410
411 /* Sum of the length of all control messages in the buffer */
412 msg.msg_controllen = cmsg->cmsg_len;
413 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
414 ret = sendmsg(server_socket, &msg, 0);
415 if (ret < 0) {
416 ret = -ERRNO_TO_PARA_ERROR(errno);
417 return ret;
418 }
419 return 1;
420 }
421
422 /**
423 * Pass the fd of the next audio file to the server process.
424 *
425 * This stores all information for streaming the "best" audio file in a shared
426 * memory area. The id of that area and an open file descriptor for the next
427 * audio file are passed to the server process.
428 *
429 * \return Standard.
430 *
431 * \sa \ref open_and_update_audio_file().
432 */
433 static int open_next_audio_file(void)
434 {
435 struct audio_file_data afd;
436 int ret, shmid;
437 char buf[8];
438
439 ret = open_and_update_audio_file(&afd);
440 if (ret < 0) {
441 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
442 goto no_admissible_files;
443 }
444 shmid = ret;
445 if (!write_ok(server_socket)) {
446 ret = -E_AFS_SOCKET;
447 goto destroy;
448 }
449 *(uint32_t *)buf = NEXT_AUDIO_FILE;
450 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
451 ret = pass_afd(afd.fd, buf, 8);
452 close(afd.fd);
453 if (ret >= 0)
454 return ret;
455 destroy:
456 shm_destroy(shmid);
457 return ret;
458 no_admissible_files:
459 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
460 *(uint32_t *)(buf + 4) = (uint32_t)0;
461 return write_all(server_socket, buf, 8);
462 }
463
464 /* Never fails if arg == NULL */
465 static int activate_mood_or_playlist(const char *arg, int *num_admissible,
466 char **errmsg)
467 {
468 enum play_mode mode;
469 int ret;
470
471 if (!arg) {
472 ret = change_current_mood(NULL, NULL); /* always successful */
473 mode = PLAY_MODE_MOOD;
474 } else {
475 if (!strncmp(arg, "p/", 2)) {
476 ret = playlist_open(arg + 2);
477 if (ret < 0 && errmsg)
478 *errmsg = make_message( "could not open %s",
479 arg);
480 mode = PLAY_MODE_PLAYLIST;
481 } else if (!strncmp(arg, "m/", 2)) {
482 ret = change_current_mood(arg + 2, errmsg);
483 mode = PLAY_MODE_MOOD;
484 } else {
485 if (errmsg)
486 *errmsg = make_message("%s: parse error", arg);
487 return -ERRNO_TO_PARA_ERROR(EINVAL);
488 }
489 if (ret < 0)
490 return ret;
491 }
492 if (num_admissible)
493 *num_admissible = ret;
494 current_play_mode = mode;
495 if (arg != current_mop) {
496 free(current_mop);
497 if (arg) {
498 current_mop = para_strdup(arg);
499 mutex_lock(mmd_mutex);
500 strncpy(mmd->afs_mode_string, arg,
501 sizeof(mmd->afs_mode_string));
502 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
503 mmd->events++;
504 mutex_unlock(mmd_mutex);
505 } else {
506 mutex_lock(mmd_mutex);
507 strcpy(mmd->afs_mode_string, "dummy");
508 mmd->events++;
509 mutex_unlock(mmd_mutex);
510 current_mop = NULL;
511 }
512 }
513 return 1;
514 }
515
516 /**
517 * Result handler for sending data to the para_client process.
518 *
519 * \param result The data to be sent.
520 * \param band The band designator.
521 * \param private Pointer to the command context.
522 *
523 * \return The return value of the underlying call to \ref command.c::send_sb.
524 *
525 * \sa \ref callback_result_handler, \ref command.c::send_sb.
526 */
527 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
528 void *private)
529 {
530 struct command_context *cc = private;
531
532 assert(cc);
533 switch (band) {
534 case SBD_OUTPUT:
535 case SBD_DEBUG_LOG:
536 case SBD_INFO_LOG:
537 case SBD_NOTICE_LOG:
538 case SBD_WARNING_LOG:
539 case SBD_ERROR_LOG:
540 case SBD_CRIT_LOG:
541 case SBD_EMERG_LOG:
542 assert(result->size > 0);
543 return send_sb(&cc->scc, result->data, result->size, band, true);
544 case SBD_AFS_CB_FAILURE:
545 return *(int *)(result->data);
546 default:
547 return -E_BAD_BAND;
548 }
549 }
550
551 static void flush_and_free_pb(struct para_buffer *pb)
552 {
553 int ret;
554 struct afs_max_size_handler_data *amshd = pb->private_data;
555
556 if (pb->buf && pb->size > 0) {
557 ret = pass_buffer_as_shm(amshd->fd, amshd->band, pb->buf,
558 pb->offset);
559 if (ret < 0)
560 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
561 }
562 free(pb->buf);
563 }
564
565 static int com_select_callback(struct afs_callback_arg *aca)
566 {
567 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
568 const char *arg;
569 int num_admissible, ret;
570 char *errmsg;
571
572 ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
573 assert(ret >= 0);
574 arg = lls_input(0, aca->lpr);
575 ret = clear_score_table();
576 if (ret < 0) {
577 para_printf(&aca->pbout, "could not clear score table\n");
578 goto free_lpr;
579 }
580 if (current_play_mode == PLAY_MODE_MOOD)
581 close_current_mood();
582 else
583 playlist_close();
584 ret = activate_mood_or_playlist(arg, &num_admissible, &errmsg);
585 if (ret >= 0)
586 goto out;
587 /* ignore subsequent errors (but log them) */
588 para_printf(&aca->pbout, "%s\n", errmsg);
589 free(errmsg);
590 para_printf(&aca->pbout, "could not activate %s\n", arg);
591 if (current_mop && strcmp(current_mop, arg) != 0) {
592 int ret2;
593 para_printf(&aca->pbout, "switching back to %s\n", current_mop);
594 ret2 = activate_mood_or_playlist(current_mop, &num_admissible,
595 &errmsg);
596 if (ret2 >= 0)
597 goto out;
598 para_printf(&aca->pbout, "%s\n", errmsg);
599 free(errmsg);
600 para_printf(&aca->pbout, "could not reactivate %s: %s\n",
601 current_mop, para_strerror(-ret2));
602 }
603 para_printf(&aca->pbout, "activating dummy mood\n");
604 activate_mood_or_playlist(NULL, &num_admissible, NULL);
605 out:
606 para_printf(&aca->pbout, "activated %s (%d admissible files)\n",
607 current_mop? current_mop : "dummy mood", num_admissible);
608 free_lpr:
609 lls_free_parse_result(aca->lpr, cmd);
610 return ret;
611 }
612
613 static int com_select(struct command_context *cc, struct lls_parse_result *lpr)
614 {
615 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
616 char *errctx;
617 int ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
618
619 if (ret < 0) {
620 send_errctx(cc, errctx);
621 return ret;
622 }
623 return send_lls_callback_request(com_select_callback, cmd, lpr, cc);
624 }
625 EXPORT_SERVER_CMD_HANDLER(select);
626
627 static void init_admissible_files(const char *arg)
628 {
629 int ret = activate_mood_or_playlist(arg, NULL, NULL);
630 if (ret < 0) {
631 assert(arg);
632 PARA_WARNING_LOG("could not activate %s: %s\n", arg,
633 para_strerror(-ret));
634 activate_mood_or_playlist(NULL, NULL, NULL);
635 }
636 }
637
638 static int setup_command_socket_or_die(void)
639 {
640 int ret, socket_fd;
641 const char *socket_name = OPT_STRING_VAL(AFS_SOCKET);
642
643 unlink(socket_name);
644 ret = create_local_socket(socket_name);
645 if (ret < 0) {
646 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
647 exit(EXIT_FAILURE);
648 }
649 socket_fd = ret;
650 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
651 socket_fd);
652 return socket_fd;
653 }
654
655 static void close_afs_tables(void)
656 {
657 int i;
658 PARA_NOTICE_LOG("closing afs_tables\n");
659 for (i = 0; i < NUM_AFS_TABLES; i++)
660 afs_tables[i].close();
661 }
662
663 static char *database_dir;
664
665 static void get_database_dir(void)
666 {
667 if (!database_dir) {
668 if (OPT_GIVEN(AFS_DATABASE_DIR))
669 database_dir = para_strdup(OPT_STRING_VAL(AFS_DATABASE_DIR));
670 else {
671 char *home = para_homedir();
672 database_dir = make_message(
673 "%s/.paraslash/afs_database-0.4", home);
674 free(home);
675 }
676 }
677 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
678 }
679
680 static int make_database_dir(void)
681 {
682 int ret;
683
684 get_database_dir();
685 ret = para_mkdir(database_dir, 0777);
686 if (ret >= 0 || ret == -ERRNO_TO_PARA_ERROR(EEXIST))
687 return 1;
688 return ret;
689 }
690
691 static int open_afs_tables(void)
692 {
693 int i, ret;
694
695 get_database_dir();
696 PARA_NOTICE_LOG("opening %d osl tables in %s\n", NUM_AFS_TABLES,
697 database_dir);
698 for (i = 0; i < NUM_AFS_TABLES; i++) {
699 ret = afs_tables[i].open(database_dir);
700 if (ret >= 0)
701 continue;
702 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
703 para_strerror(-ret));
704 break;
705 }
706 if (ret >= 0)
707 return ret;
708 while (i)
709 afs_tables[--i].close();
710 return ret;
711 }
712
713 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
714 {
715 int signum, ret;
716
717 if (getppid() == 1) {
718 PARA_EMERG_LOG("para_server died\n");
719 goto shutdown;
720 }
721 signum = para_next_signal(&s->rfds);
722 if (signum == 0)
723 return 0;
724 if (signum == SIGHUP) {
725 close_afs_tables();
726 parse_config_or_die(1);
727 ret = open_afs_tables();
728 if (ret < 0)
729 return ret;
730 init_admissible_files(current_mop);
731 return 0;
732 }
733 PARA_EMERG_LOG("terminating on signal %d\n", signum);
734 shutdown:
735 task_notify_all(s, E_AFS_SIGNAL);
736 return -E_AFS_SIGNAL;
737 }
738
739 static void register_signal_task(struct sched *s)
740 {
741 para_sigaction(SIGPIPE, SIG_IGN);
742 signal_task = signal_init_or_die();
743 para_install_sighandler(SIGINT);
744 para_install_sighandler(SIGTERM);
745 para_install_sighandler(SIGHUP);
746
747 signal_task->task = task_register(&(struct task_info) {
748 .name = "signal",
749 .pre_select = signal_pre_select,
750 .post_select = afs_signal_post_select,
751 .context = signal_task,
752
753 }, s);
754 }
755
756 static struct list_head afs_client_list;
757
758 /** Describes one connected afs client. */
759 struct afs_client {
760 /** Position in the afs client list. */
761 struct list_head node;
762 /** The socket file descriptor for this client. */
763 int fd;
764 /** The time the client connected. */
765 struct timeval connect_time;
766 };
767
768 static void command_pre_select(struct sched *s, void *context)
769 {
770 struct command_task *ct = context;
771 struct afs_client *client;
772
773 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
774 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
775 list_for_each_entry(client, &afs_client_list, node)
776 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
777 }
778
779 /**
780 * Send data as shared memory to a file descriptor.
781 *
782 * \param fd File descriptor to send the shmid to.
783 * \param band The band designator for this data.
784 * \param buf The buffer holding the data to be sent.
785 * \param size The size of \a buf.
786 *
787 * This function creates a shared memory area large enough to hold
788 * the content given by \a buf and \a size and sends the identifier
789 * of this area to the file descriptor \a fd.
790 *
791 * It is called by the AFS max_size handler as well as directly by the AFS
792 * command callbacks to send command output to the command handlers.
793 *
794 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
795 * and positive on success.
796 */
797 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
798 {
799 int ret, shmid;
800 void *shm;
801 struct callback_result *cr;
802
803 if (size == 0)
804 assert(band != SBD_OUTPUT);
805 ret = shm_new(size + sizeof(*cr));
806 if (ret < 0)
807 return ret;
808 shmid = ret;
809 ret = shm_attach(shmid, ATTACH_RW, &shm);
810 if (ret < 0)
811 goto err;
812 cr = shm;
813 cr->result_size = size;
814 cr->band = band;
815 if (size > 0)
816 memcpy(shm + sizeof(*cr), buf, size);
817 ret = shm_detach(shm);
818 if (ret < 0)
819 goto err;
820 ret = write_all(fd, (char *)&shmid, sizeof(int));
821 if (ret >= 0)
822 return ret;
823 err:
824 if (shm_destroy(shmid) < 0)
825 PARA_ERROR_LOG("destroy result failed\n");
826 return ret;
827 }
828
829 static int call_callback(int fd, int query_shmid)
830 {
831 void *query_shm;
832 struct callback_query *cq;
833 int ret, ret2;
834 struct afs_callback_arg aca = {.fd = fd};
835
836 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
837 if (ret < 0)
838 return ret;
839 cq = query_shm;
840 aca.query.data = (char *)query_shm + sizeof(*cq);
841 aca.query.size = cq->query_size;
842 aca.pbout.max_size = shm_get_shmmax();
843 aca.pbout.max_size_handler = afs_max_size_handler;
844 aca.pbout.private_data = &(struct afs_max_size_handler_data) {
845 .fd = fd,
846 .band = SBD_OUTPUT
847 };
848 ret = cq->handler(&aca);
849 ret2 = shm_detach(query_shm);
850 if (ret2 < 0) {
851 if (ret < 0) /* ignore (but log) detach error */
852 PARA_ERROR_LOG("could not detach sma: %s\n",
853 para_strerror(-ret2));
854 else
855 ret = ret2;
856 }
857 flush_and_free_pb(&aca.pbout);
858 if (ret < 0) {
859 ret2 = pass_buffer_as_shm(fd, SBD_AFS_CB_FAILURE,
860 (const char *)&ret, sizeof(ret));
861 if (ret2 < 0)
862 PARA_ERROR_LOG("could not pass cb failure packet: %s\n",
863 para_strerror(-ret));
864 }
865 return ret;
866 }
867
868 static int execute_server_command(fd_set *rfds)
869 {
870 char buf[8];
871 size_t n;
872 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
873
874 if (ret < 0 || n == 0)
875 return ret;
876 buf[n] = '\0';
877 if (strcmp(buf, "new"))
878 return -ERRNO_TO_PARA_ERROR(EINVAL);
879 return open_next_audio_file();
880 }
881
882 /* returns 0 if no data available, 1 else */
883 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
884 {
885 uint32_t cookie;
886 int query_shmid;
887 char buf[sizeof(cookie) + sizeof(query_shmid)];
888 size_t n;
889 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
890
891 if (ret < 0)
892 goto err;
893 if (n == 0)
894 return 0;
895 if (n != sizeof(buf)) {
896 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
897 ret, (long unsigned) sizeof(buf));
898 return 1;
899 }
900 cookie = *(uint32_t *)buf;
901 if (cookie != expected_cookie) {
902 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
903 (unsigned)cookie, (unsigned)expected_cookie);
904 return 1;
905 }
906 query_shmid = *(int *)(buf + sizeof(cookie));
907 if (query_shmid < 0) {
908 PARA_WARNING_LOG("received invalid query shmid %d)\n",
909 query_shmid);
910 return 1;
911 }
912 ret = call_callback(fd, query_shmid);
913 if (ret >= 0)
914 return 1;
915 err:
916 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
917 return 1;
918 }
919
920 /** Shutdown connection if query has not arrived until this many seconds. */
921 #define AFS_CLIENT_TIMEOUT 3
922
923 static int command_post_select(struct sched *s, void *context)
924 {
925 struct command_task *ct = context;
926 struct sockaddr_un unix_addr;
927 struct afs_client *client, *tmp;
928 int fd, ret;
929
930 ret = task_get_notification(ct->task);
931 if (ret < 0)
932 return ret;
933 ret = execute_server_command(&s->rfds);
934 if (ret < 0) {
935 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
936 task_notify_all(s, -ret);
937 return ret;
938 }
939 /* Check the list of connected clients. */
940 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
941 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
942 if (ret == 0) { /* prevent bogus connection flooding */
943 struct timeval diff;
944 tv_diff(now, &client->connect_time, &diff);
945 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
946 continue;
947 PARA_WARNING_LOG("connection timeout\n");
948 }
949 close(client->fd);
950 list_del(&client->node);
951 free(client);
952 }
953 /* Accept connections on the local socket. */
954 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
955 if (ret < 0)
956 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
957 if (ret <= 0)
958 return 0;
959 ret = mark_fd_nonblocking(fd);
960 if (ret < 0) {
961 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
962 close(fd);
963 return 0;
964 }
965 client = para_malloc(sizeof(*client));
966 client->fd = fd;
967 client->connect_time = *now;
968 para_list_add(&client->node, &afs_client_list);
969 return 0;
970 }
971
972 static void register_command_task(uint32_t cookie, struct sched *s)
973 {
974 struct command_task *ct = &command_task_struct;
975 ct->fd = setup_command_socket_or_die();
976 ct->cookie = cookie;
977
978 ct->task = task_register(&(struct task_info) {
979 .name = "afs command",
980 .pre_select = command_pre_select,
981 .post_select = command_post_select,
982 .context = ct,
983 }, s);
984 }
985
986 /**
987 * Initialize the audio file selector process.
988 *
989 * \param cookie The value used for "authentication".
990 * \param socket_fd File descriptor used for communication with the server.
991 */
992 __noreturn void afs_init(uint32_t cookie, int socket_fd)
993 {
994 static struct sched s;
995 int i, ret;
996
997 register_signal_task(&s);
998 INIT_LIST_HEAD(&afs_client_list);
999 for (i = 0; i < NUM_AFS_TABLES; i++)
1000 afs_tables[i].init(&afs_tables[i]);
1001 ret = open_afs_tables();
1002 if (ret < 0)
1003 goto out;
1004 server_socket = socket_fd;
1005 ret = mark_fd_nonblocking(server_socket);
1006 if (ret < 0)
1007 goto out_close;
1008 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1009 server_socket, (unsigned) cookie);
1010 init_admissible_files(OPT_STRING_VAL(AFS_INITIAL_MODE));
1011 register_command_task(cookie, &s);
1012 s.default_timeout.tv_sec = 0;
1013 s.default_timeout.tv_usec = 999 * 1000;
1014 ret = write(socket_fd, "\0", 1);
1015 if (ret != 1) {
1016 if (ret == 0)
1017 errno = EINVAL;
1018 ret = -ERRNO_TO_PARA_ERROR(errno);
1019 goto out_close;
1020 }
1021 ret = schedule(&s);
1022 sched_shutdown(&s);
1023 out_close:
1024 close_afs_tables();
1025 out:
1026 if (ret < 0)
1027 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1028 exit(EXIT_FAILURE);
1029 }
1030
1031 static int com_init_callback(struct afs_callback_arg *aca)
1032 {
1033 uint32_t table_mask = *(uint32_t *)aca->query.data;
1034 int i, ret;
1035
1036 close_afs_tables();
1037 for (i = 0; i < NUM_AFS_TABLES; i++) {
1038 struct afs_table *t = &afs_tables[i];
1039
1040 if (!(table_mask & (1 << i)))
1041 continue;
1042 if (!t->create)
1043 continue;
1044 ret = t->create(database_dir);
1045 if (ret < 0) {
1046 para_printf(&aca->pbout, "cannot create table %s\n",
1047 t->name);
1048 goto out;
1049 }
1050 para_printf(&aca->pbout, "successfully created %s table\n",
1051 t->name);
1052 }
1053 ret = open_afs_tables();
1054 if (ret < 0)
1055 para_printf(&aca->pbout, "cannot open afs tables\n");
1056 out:
1057 return ret;
1058 }
1059
1060 static int com_init(struct command_context *cc, struct lls_parse_result *lpr)
1061 {
1062 int i, j, ret;
1063 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1064 struct osl_object query = {.data = &table_mask,
1065 .size = sizeof(table_mask)};
1066 unsigned num_inputs = lls_num_inputs(lpr);
1067
1068 ret = make_database_dir();
1069 if (ret < 0)
1070 return ret;
1071 if (num_inputs > 0) {
1072 table_mask = 0;
1073 for (i = 0; i < num_inputs; i++) {
1074 for (j = 0; j < NUM_AFS_TABLES; j++) {
1075 struct afs_table *t = &afs_tables[j];
1076
1077 if (strcmp(lls_input(i, lpr), t->name))
1078 continue;
1079 table_mask |= (1 << j);
1080 break;
1081 }
1082 if (j == NUM_AFS_TABLES)
1083 return -E_BAD_TABLE_NAME;
1084 }
1085 }
1086 return send_callback_request(com_init_callback, &query,
1087 afs_cb_result_handler, cc);
1088 }
1089 EXPORT_SERVER_CMD_HANDLER(init);
1090
1091 static int com_check(struct command_context *cc, struct lls_parse_result *lpr)
1092 {
1093 const struct lls_opt_result *r_a = SERVER_CMD_OPT_RESULT(CHECK, AFT, lpr);
1094 const struct lls_opt_result *r_A = SERVER_CMD_OPT_RESULT(CHECK, ATTRIBUTE, lpr);
1095 const struct lls_opt_result *r_m = SERVER_CMD_OPT_RESULT(CHECK, MOOD, lpr);
1096 const struct lls_opt_result *r_p = SERVER_CMD_OPT_RESULT(CHECK, PLAYLIST, lpr);
1097 bool noopt = !lls_opt_given(r_a) && !lls_opt_given(r_A)
1098 && !lls_opt_given(r_m) && !lls_opt_given(r_p);
1099 int ret;
1100
1101 if (noopt || lls_opt_given(r_a)) {
1102 ret = send_callback_request(aft_check_callback, NULL,
1103 afs_cb_result_handler, cc);
1104 if (ret < 0)
1105 return ret;
1106 }
1107 if (noopt || lls_opt_given(r_A)) {
1108 ret = send_callback_request(attribute_check_callback, NULL,
1109 afs_cb_result_handler, cc);
1110 if (ret < 0)
1111 return ret;
1112 }
1113 if (noopt || lls_opt_given(r_p)) {
1114 ret = send_callback_request(playlist_check_callback,
1115 NULL, afs_cb_result_handler, cc);
1116 if (ret < 0)
1117 return ret;
1118 }
1119 if (noopt || lls_opt_given(r_m)) {
1120 ret = send_callback_request(mood_check_callback, NULL,
1121 afs_cb_result_handler, cc);
1122 if (ret < 0)
1123 return ret;
1124 }
1125 return 1;
1126 }
1127 EXPORT_SERVER_CMD_HANDLER(check);
1128
1129 /**
1130 * The afs event dispatcher.
1131 *
1132 * \param event Type of the event.
1133 * \param pb May be \p NULL.
1134 * \param data Type depends on \a event.
1135 *
1136 * This function calls each table event handler, passing \a pb and \a data
1137 * verbatim. It's up to the handlers to interpret the \a data pointer. If a
1138 * handler returns negative, the loop is aborted.
1139 *
1140 * \return The (negative) error code of the first handler that failed, or non-negative
1141 * if all handlers succeeded.
1142 */
1143 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
1144 void *data)
1145 {
1146 int i, ret;
1147
1148 for (i = 0; i < NUM_AFS_TABLES; i++) {
1149 struct afs_table *t = &afs_tables[i];
1150 if (!t->event_handler)
1151 continue;
1152 ret = t->event_handler(event, pb, data);
1153 if (ret < 0) {
1154 PARA_CRIT_LOG("table %s, event %u: %s\n", t->name,
1155 event, para_strerror(-ret));
1156 return ret;
1157 }
1158 }
1159 return 1;
1160 }
1161
1162 /**
1163 * Dummy event handler for the images table.
1164 *
1165 * \param event Unused.
1166 * \param pb Unused.
1167 * \param data Unused.
1168 *
1169 * \return The images table does not honor events, so this handler always
1170 * returns success.
1171 */
1172 __a_const int images_event_handler(__a_unused enum afs_events event,
1173 __a_unused struct para_buffer *pb, __a_unused void *data)
1174 {
1175 return 1;
1176 }
1177
1178 /**
1179 * Dummy event handler for the lyrics table.
1180 *
1181 * \param event Unused.
1182 * \param pb Unused.
1183 * \param data Unused.
1184 *
1185 * \return The lyrics table does not honor events, so this handler always
1186 * returns success.
1187 */
1188 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1189 __a_unused struct para_buffer *pb, __a_unused void *data)
1190 {
1191 return 1;
1192 }