vss: unify calls to the FEC layer
[paraslash.git] / vss.c
1 /*
2 * Copyright (C) 1997-2010 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file vss.c The virtual streaming system.
8 *
9 * This contains the audio streaming code of para_server which is independent
10 * of the current audio format, audio file selector and of the activated
11 * senders.
12 */
13
14 #include <regex.h>
15 #include <dirent.h>
16 #include <osl.h>
17
18 #include "para.h"
19 #include "error.h"
20 #include "portable_io.h"
21 #include "fec.h"
22 #include "string.h"
23 #include "afh.h"
24 #include "afs.h"
25 #include "server.h"
26 #include "net.h"
27 #include "server.cmdline.h"
28 #include "list.h"
29 #include "send.h"
30 #include "vss.h"
31 #include "ipc.h"
32 #include "fd.h"
33 #include "sched.h"
34
35 extern struct misc_meta_data *mmd;
36
37 extern void dccp_send_init(struct sender *);
38 extern void http_send_init(struct sender *);
39 extern void udp_send_init(struct sender *);
40
41 /** The list of supported senders. */
42 struct sender senders[] = {
43 {
44 .name = "http",
45 .init = http_send_init,
46 },
47 {
48 .name = "dccp",
49 .init = dccp_send_init,
50 },
51 {
52 .name = "udp",
53 .init = udp_send_init,
54 },
55 {
56 .name = NULL,
57 }
58 };
59
60 /** The possible states of the afs socket. */
61 enum afs_socket_status {
62 /** Socket is inactive. */
63 AFS_SOCKET_READY,
64 /** Socket fd was included in the write fd set for select(). */
65 AFS_SOCKET_CHECK_FOR_WRITE,
66 /** vss wrote a request to the socket and waits for reply from afs. */
67 AFS_SOCKET_AFD_PENDING
68 };
69
70 /** The task structure for the virtual streaming system. */
71 struct vss_task {
72 /** Copied from the -announce_time command line option. */
73 struct timeval announce_tv;
74 /** End of the announcing interval. */
75 struct timeval data_send_barrier;
76 /** End of the EOF interval. */
77 struct timeval eof_barrier;
78 /** Only used if --autoplay_delay was given. */
79 struct timeval autoplay_barrier;
80 /** Used for afs-server communication. */
81 int afs_socket;
82 /** The current state of \a afs_socket. */
83 enum afs_socket_status afsss;
84 /** The memory mapped audio file. */
85 char *map;
86 /** Used by the scheduler. */
87 struct task task;
88 /** Pointer to the header of the mapped audio file. */
89 const char *header_buf;
90 /** Length of the audio file header. */
91 size_t header_len;
92 /** Time between audio file headers are sent. */
93 struct timeval header_interval;
94 };
95
96 /**
97 * The list of currently connected fec clients.
98 *
99 * Senders may use \ref vss_add_fec_client() to add entries to the list.
100 */
101 static struct list_head fec_client_list;
102
103 /**
104 * Data associated with one FEC group.
105 *
106 * A FEC group consists of a fixed number of slices and this number is given by
107 * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
108 * group contains a number of chunks of the current audio file.
109 *
110 * FEC slices directly correspond to the data packages sent by the paraslash
111 * senders that use FEC. Each slice is identified by its group number and its
112 * number within the group. All slices have the same size, but the last slice
113 * of the group may not be filled entirely.
114 */
115 struct fec_group {
116 /** The number of the FEC group. */
117 uint32_t num;
118 /** Number of bytes in this group. */
119 uint32_t bytes;
120 /** The first chunk of the current audio file belonging to the group. */
121 uint32_t first_chunk;
122 /** The number of chunks contained in this group. */
123 uint32_t num_chunks;
124 /** When the first chunk was sent. */
125 struct timeval start;
126 /** The duration of the full group. */
127 struct timeval duration;
128 /** The group duration divided by the number of slices. */
129 struct timeval slice_duration;
130 /** Group contains the audio file header that occupies that many slices. */
131 uint8_t num_header_slices;
132 };
133
134 /**
135 * Describes one connected FEC client.
136 */
137 struct fec_client {
138 /** If negative, this client is temporarily disabled. */
139 int error;
140 /** Whether the sender client is ready to push out data. */
141 bool ready;
142 /** The connected sender client (transport layer). */
143 struct sender_client *sc;
144 /** Parameters requested by the client. */
145 struct fec_client_parms *fcp;
146 /** Used by the core FEC code. */
147 struct fec_parms *parms;
148 /** The position of this client in the fec client list. */
149 struct list_head node;
150 /** When the first slice for this client was sent. */
151 struct timeval stream_start;
152 /** The first chunk sent to this FEC client. */
153 int first_stream_chunk;
154 /** Describes the current group. */
155 struct fec_group group;
156 /** The current slice. */
157 uint8_t current_slice_num;
158 /** The data to be FEC-encoded (point to a region within the mapped audio file). */
159 const unsigned char **src_data;
160 /** Last time an audio header was sent. */
161 struct timeval next_header_time;
162 /** Used for the last source pointer of an audio file. */
163 unsigned char *extra_src_buf;
164 /** Extra slices needed to store largest chunk + header. */
165 int num_extra_slices;
166 /** Contains the FEC-encoded data. */
167 unsigned char *enc_buf;
168 /** Pointer obtained from sender when the client is added. */
169 void *private_data;
170 };
171
172 /**
173 * Get the chunk time of the current audio file.
174 *
175 * \return A pointer to a struct containing the chunk time, or NULL,
176 * if currently no audio file is selected.
177 */
178 struct timeval *vss_chunk_time(void)
179 {
180 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
181 mmd->afd.afhi.chunk_tv.tv_usec == 0)
182 return NULL;
183 return &mmd->afd.afhi.chunk_tv;
184 }
185
186 /**
187 * Write a fec header to a buffer.
188 *
189 * \param buf The buffer to write to.
190 * \param h The fec header to write.
191 */
192 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
193 {
194 char *buf = (char *)fc->enc_buf;
195 struct fec_group *g = &fc->group;
196 struct fec_client_parms *p = fc->fcp;
197
198 write_u32(buf, FEC_MAGIC);
199
200 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
201 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
202 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
203
204 write_u32(buf + 10, g->num);
205 write_u32(buf + 14, g->bytes);
206
207 write_u8(buf + 18, fc->current_slice_num);
208 write_u16(buf + 20, p->max_slice_bytes - FEC_HEADER_SIZE);
209 write_u8(buf + 22, g->first_chunk? 0 : 1);
210 write_u8(buf + 23, vsst->header_len? 1 : 0);
211 memset(buf + 24, 0, 7);
212 }
213
214 static int need_audio_header(struct fec_client *fc, struct vss_task *vsst)
215 {
216 if (!mmd->current_chunk) {
217 tv_add(now, &vsst->header_interval, &fc->next_header_time);
218 return 0;
219 }
220 if (!vsst->header_buf)
221 return 0;
222 if (!vsst->header_len)
223 return 0;
224 if (fc->group.num && tv_diff(&fc->next_header_time, now, NULL) > 0)
225 return 0;
226 tv_add(now, &vsst->header_interval, &fc->next_header_time);
227 return 1;
228 }
229
230 static int num_slices(long unsigned bytes, struct fec_client *fc, uint8_t *result)
231 {
232 unsigned long m = fc->fcp->max_slice_bytes - FEC_HEADER_SIZE;
233 unsigned rv, redundant_slices = fc->fcp->slices_per_group
234 - fc->fcp->data_slices_per_group;
235
236 if (!m)
237 return -E_BAD_CT;
238 rv = (bytes + m - 1) / m;
239 if (rv + redundant_slices > 255)
240 return -E_BAD_CT;
241 *result = rv;
242 return 1;
243 }
244
245 /* set group start and group duration */
246 static void set_group_timing(struct fec_client *fc, struct fec_group *g)
247 {
248 struct timeval *chunk_tv = vss_chunk_time();
249
250 tv_scale(g->num_chunks, chunk_tv, &g->duration);
251 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
252 &g->duration, &g->slice_duration);
253 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
254 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
255 }
256
257 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
258 {
259 int ret, i, k, data_slices;
260 size_t len;
261 const char *buf, *start_buf;
262 struct fec_group *g = &fc->group;
263 unsigned slice_bytes = fc->fcp->max_slice_bytes - FEC_HEADER_SIZE;
264 uint32_t max_data_size;
265
266 if (fc->first_stream_chunk < 0) {
267 uint8_t hs, ds; /* needed header/data slices */
268 uint8_t rs = fc->fcp->slices_per_group
269 - fc->fcp->data_slices_per_group; /* redundant slices */
270 int n;
271
272 ret = num_slices(vsst->header_len, fc, &hs);
273 if (ret < 0)
274 return ret;
275 ret = num_slices(afh_get_largest_chunk_size(&mmd->afd.afhi),
276 fc, &ds);
277 if (ret < 0)
278 return ret;
279 k = (int)hs + ds;
280 if (k > 255)
281 return -E_BAD_CT;
282 if (k < fc->fcp->data_slices_per_group)
283 k = fc->fcp->data_slices_per_group;
284 n = k + rs;
285 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
286 PARA_NOTICE_LOG("fec parms %d:%d:%d (%d extra slices)\n",
287 slice_bytes, k, n, fc->num_extra_slices);
288 fec_free(fc->parms);
289 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
290 ret = fec_new(k, n, &fc->parms);
291 if (ret < 0)
292 return ret;
293 fc->stream_start = *now;
294 fc->first_stream_chunk = mmd->current_chunk;
295 g->first_chunk = mmd->current_chunk;
296 g->num = 0;
297 g->start = *now;
298 } else {
299 struct timeval tmp;
300 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
301 return 0;
302 /*
303 * Start and duration of this group depend only on the previous
304 * group. Compute the new group start as g->start += g->duration.
305 */
306 tmp = g->start;
307 tv_add(&tmp, &g->duration, &g->start);
308 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
309 set_group_timing(fc, g);
310 g->first_chunk += g->num_chunks;
311 g->num++;
312 }
313 if (need_audio_header(fc, vsst)) {
314 ret = num_slices(vsst->header_len, fc, &g->num_header_slices);
315 if (ret < 0)
316 return ret;
317 } else
318 g->num_header_slices = 0;
319 afh_get_chunk(g->first_chunk, &mmd->afd.afhi, vsst->map, &start_buf,
320 &len);
321 data_slices = k - g->num_header_slices;
322 assert(data_slices);
323 max_data_size = slice_bytes * data_slices;
324 g->bytes = 0;
325 for (i = g->first_chunk; i < mmd->afd.afhi.chunks_total; i++) {
326 afh_get_chunk(i, &mmd->afd.afhi, vsst->map, &buf, &len);
327 if (g->bytes + len > max_data_size)
328 break;
329 g->bytes += len;
330 }
331 g->num_chunks = i - g->first_chunk;
332 assert(g->num_chunks);
333 fc->current_slice_num = 0;
334 if (g->num == 0)
335 set_group_timing(fc, g);
336
337 /* setup header slices */
338 buf = vsst->header_buf;
339 for (i = 0; i < g->num_header_slices; i++) {
340 fc->src_data[i] = (const unsigned char *)buf;
341 buf += slice_bytes;
342 }
343
344 /* setup data slices */
345 buf = start_buf;
346 for (i = g->num_header_slices; i < k; i++) {
347 if (buf + slice_bytes > vsst->map + mmd->size)
348 /*
349 * Can not use the memory mapped audio file for this
350 * slice as it goes beyond the map. This slice will not
351 * be fully used.
352 */
353 break;
354 fc->src_data[i] = (const unsigned char *)buf;
355 buf += slice_bytes;
356 }
357 if (i < k) {
358 uint32_t payload_size = vsst->map + mmd->size - buf;
359 memcpy(fc->extra_src_buf, buf, payload_size);
360 fc->src_data[i] = fc->extra_src_buf;
361 i++;
362 /* use arbitrary data for all remaining slices */
363 buf = vsst->map;
364 for (; i < k; i++)
365 fc->src_data[i] = (const unsigned char *)buf;
366 }
367 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), "
368 "%d header slices, %d data slices\n",
369 g->num, g->num_chunks, g->first_chunk,
370 g->first_chunk + g->num_chunks - 1,
371 g->num_header_slices, data_slices
372 );
373 return 1;
374 }
375
376 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
377 {
378 assert(fc->error >= 0);
379 if (fc->first_stream_chunk < 0 || fc->current_slice_num
380 == fc->fcp->slices_per_group + fc->num_extra_slices) {
381 int ret = setup_next_fec_group(fc, vsst);
382 if (ret == 0)
383 return 0;
384 if (ret < 0) {
385 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
386 PARA_ERROR_LOG("FEC client temporarily disabled\n");
387 fc->error = ret;
388 return fc->error;
389 }
390 }
391 write_fec_header(fc, vsst);
392 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
393 fc->current_slice_num,
394 fc->fcp->max_slice_bytes - FEC_HEADER_SIZE);
395 return 1;
396 }
397
398 /**
399 * Return a buffer that marks the end of the stream.
400 *
401 * \param buf Result pointer.
402 * \return The length of the eof buffer.
403 *
404 * This is used for (multicast) udp streaming where closing the socket on the
405 * sender might not give rise to an eof condition at the peer.
406 */
407 size_t vss_get_fec_eof_packet(const char **buf)
408 {
409 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
410 *buf = fec_eof_packet;
411 return FEC_HEADER_SIZE;
412 }
413
414 /**
415 * Add one entry to the list of active fec clients.
416 *
417 * \param sc Generic sender_client data of the transport layer.
418 * \param fcp FEC parameters as supplied by the transport layer.
419 *
420 * \return Newly allocated fec_client struct.
421 */
422 struct fec_client *vss_add_fec_client(struct sender_client *sc,
423 struct fec_client_parms *fcp)
424 {
425 struct fec_client *fc = para_calloc(sizeof(*fc));
426
427 fc->sc = sc;
428 fc->fcp = fcp;
429 para_list_add(&fc->node, &fec_client_list);
430 return fc;
431 }
432
433 /**
434 * Remove one entry from the list of active fec clients.
435 *
436 * \param fc The client to be removed.
437 */
438 void vss_del_fec_client(struct fec_client *fc)
439 {
440 list_del(&fc->node);
441 free(fc->src_data);
442 free(fc->enc_buf);
443 free(fc->extra_src_buf);
444 fec_free(fc->parms);
445 free(fc);
446 }
447
448 /*
449 * Compute if/when next slice is due. If it isn't due yet and \a diff is
450 * not \p Null, compute the time difference next - now, where
451 *
452 * next = stream_start + (first_group_chunk - first_stream_chunk)
453 * * chunk_time + slice_num * slice_time
454 */
455 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
456 {
457 struct timeval tmp, next;
458 int ret;
459
460 if (fc->first_stream_chunk < 0)
461 return 1;
462 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
463 tv_add(&tmp, &fc->group.start, &next);
464 ret = tv_diff(&next, now, diff);
465 return ret < 0? 1 : 0;
466 }
467
468 static void compute_slice_timeout(struct timeval *timeout)
469 {
470 struct fec_client *fc;
471
472 assert(vss_playing());
473 list_for_each_entry(fc, &fec_client_list, node) {
474 struct timeval diff;
475
476 if (fc->error < 0)
477 continue;
478 if (next_slice_is_due(fc, &diff)) {
479 timeout->tv_sec = 0;
480 timeout->tv_usec = 0;
481 return;
482 }
483 /* timeout = min(timeout, diff) */
484 if (tv_diff(&diff, timeout, NULL) < 0)
485 *timeout = diff;
486 }
487 }
488
489 static void set_eof_barrier(struct vss_task *vsst)
490 {
491 struct fec_client *fc;
492 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
493
494 if (!chunk_tv)
495 goto out;
496 list_for_each_entry(fc, &fec_client_list, node) {
497 struct timeval group_duration;
498
499 if (fc->error < 0)
500 continue;
501 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
502 if (tv_diff(&timeout, &group_duration, NULL) < 0)
503 timeout = group_duration;
504 }
505 out:
506 tv_add(now, &timeout, &vsst->eof_barrier);
507 }
508
509 /**
510 * Check if vss status flag \a P (playing) is set.
511 *
512 * \return Greater than zero if playing, zero otherwise.
513 *
514 */
515 unsigned int vss_playing(void)
516 {
517 return mmd->new_vss_status_flags & VSS_PLAYING;
518 }
519
520 /**
521 * Check if the \a N (next) status flag is set.
522 *
523 * \return Greater than zero if set, zero if not.
524 *
525 */
526 unsigned int vss_next(void)
527 {
528 return mmd->new_vss_status_flags & VSS_NEXT;
529 }
530
531 /**
532 * Check if a reposition request is pending.
533 *
534 * \return Greater than zero if true, zero otherwise.
535 *
536 */
537 unsigned int vss_repos(void)
538 {
539 return mmd->new_vss_status_flags & VSS_REPOS;
540 }
541
542 /**
543 * Check if the vss is currently paused.
544 *
545 * \return Greater than zero if paused, zero otherwise.
546 *
547 */
548 unsigned int vss_paused(void)
549 {
550 return !(mmd->new_vss_status_flags & VSS_NEXT)
551 && !(mmd->new_vss_status_flags & VSS_PLAYING);
552 }
553
554 /**
555 * Check if the vss is currently stopped.
556 *
557 * \return Greater than zero if paused, zero otherwise.
558 *
559 */
560 unsigned int vss_stopped(void)
561 {
562 return (mmd->new_vss_status_flags & VSS_NEXT)
563 && !(mmd->new_vss_status_flags & VSS_PLAYING);
564 }
565
566 static int chk_barrier(const char *bname, const struct timeval *barrier,
567 struct timeval *diff, int print_log)
568 {
569 long ms;
570
571 if (tv_diff(now, barrier, diff) > 0)
572 return 1;
573 ms = tv2ms(diff);
574 if (print_log && ms)
575 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
576 return -1;
577 }
578
579 /*
580 * != NULL: timeout for next chunk
581 * NULL: nothing to do
582 */
583 static struct timeval *vss_compute_timeout(struct vss_task *vsst)
584 {
585 static struct timeval the_timeout;
586 struct timeval next_chunk;
587
588 if (vss_next() && vsst->map) {
589 /* only sleep a bit, nec*/
590 the_timeout.tv_sec = 0;
591 the_timeout.tv_usec = 100;
592 return &the_timeout;
593 }
594 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
595 &the_timeout, 1) < 0)
596 return &the_timeout;
597 if (chk_barrier("eof", &vsst->eof_barrier, &the_timeout, 1) < 0)
598 return &the_timeout;
599 if (chk_barrier("data send", &vsst->data_send_barrier,
600 &the_timeout, 1) < 0)
601 return &the_timeout;
602 if (!vss_playing() || !vsst->map)
603 return NULL;
604 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
605 &mmd->stream_start, &next_chunk);
606 if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) >= 0) {
607 /* chunk is due or bof */
608 the_timeout.tv_sec = 0;
609 the_timeout.tv_usec = 0;
610 return &the_timeout;
611 }
612 /* compute min of current timeout and next slice time */
613 compute_slice_timeout(&the_timeout);
614 return &the_timeout;
615 }
616
617 static void vss_eof(struct vss_task *vsst)
618 {
619
620 if (!vsst->map)
621 return;
622 if (mmd->new_vss_status_flags & VSS_NOMORE)
623 mmd->new_vss_status_flags = VSS_NEXT;
624 set_eof_barrier(vsst);
625 para_munmap(vsst->map, mmd->size);
626 vsst->map = NULL;
627 mmd->chunks_sent = 0;
628 //mmd->offset = 0;
629 mmd->afd.afhi.seconds_total = 0;
630 mmd->afd.afhi.chunk_tv.tv_sec = 0;
631 mmd->afd.afhi.chunk_tv.tv_usec = 0;
632 free(mmd->afd.afhi.chunk_table);
633 mmd->afd.afhi.chunk_table = NULL;
634 mmd->mtime = 0;
635 mmd->size = 0;
636 mmd->events++;
637 }
638
639 /**
640 * Get the list of all supported audio formats.
641 *
642 * \return Aa space separated list of all supported audio formats
643 * It is not allocated at runtime, i.e. there is no need to free
644 * the returned string in the caller.
645 */
646 const char *supported_audio_formats(void)
647 {
648 return SUPPORTED_AUDIO_FORMATS;
649 }
650
651 static int need_to_request_new_audio_file(struct vss_task *vsst)
652 {
653 struct timeval diff;
654
655 if (vsst->map) /* have audio file */
656 return 0;
657 if (!vss_playing()) /* don't need one */
658 return 0;
659 if (mmd->new_vss_status_flags & VSS_NOMORE)
660 return 0;
661 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
662 return 0;
663 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
664 &diff, 1) < 0)
665 return 0;
666 return 1;
667 }
668
669 static void set_mmd_offset(void)
670 {
671 struct timeval offset;
672 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
673 mmd->offset = tv2ms(&offset);
674 }
675
676 /**
677 * Compute the timeout for the main select-loop of the scheduler.
678 *
679 * \param s Pointer to the server scheduler.
680 * \param t Pointer to the vss task structure.
681 *
682 * Before the timeout is computed, the current vss status flags are evaluated
683 * and acted upon by calling appropriate functions from the lower layers.
684 * Possible actions include
685 *
686 * - request a new audio file from afs,
687 * - shutdown of all senders (stop/pause command),
688 * - reposition the stream (ff/jmp command).
689 */
690 static void vss_pre_select(struct sched *s, struct task *t)
691 {
692 int i;
693 struct timeval *tv, diff;
694 struct vss_task *vsst = container_of(t, struct vss_task, task);
695
696 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
697 struct fec_client *fc, *tmp;
698 for (i = 0; senders[i].name; i++)
699 if (senders[i].shutdown_clients)
700 senders[i].shutdown_clients();
701 list_for_each_entry_safe(fc, tmp, &fec_client_list, node) {
702 fc->first_stream_chunk = -1;
703 fc->error = 0;
704 }
705 mmd->stream_start.tv_sec = 0;
706 mmd->stream_start.tv_usec = 0;
707 }
708 if (vss_next())
709 vss_eof(vsst);
710 else if (vss_paused()) {
711 if (mmd->chunks_sent)
712 set_eof_barrier(vsst);
713 mmd->chunks_sent = 0;
714 } else if (vss_repos()) {
715 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
716 set_eof_barrier(vsst);
717 mmd->chunks_sent = 0;
718 mmd->current_chunk = mmd->repos_request;
719 mmd->new_vss_status_flags &= ~VSS_REPOS;
720 set_mmd_offset();
721 }
722 if (need_to_request_new_audio_file(vsst)) {
723 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
724 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
725 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
726 } else
727 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
728 for (i = 0; senders[i].name; i++) {
729 if (!senders[i].pre_select)
730 continue;
731 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
732 }
733 tv = vss_compute_timeout(vsst);
734 if (tv && tv_diff(tv, &s->timeout, &diff) < 0)
735 s->timeout = *tv;
736 }
737
738 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
739 {
740 char control[255], buf[8];
741 struct msghdr msg = {.msg_iov = NULL};
742 struct cmsghdr *cmsg;
743 struct iovec iov;
744 int ret = 0;
745
746 *fd = -1;
747 iov.iov_base = buf;
748 iov.iov_len = sizeof(buf);
749 msg.msg_iov = &iov;
750 msg.msg_iovlen = 1;
751 msg.msg_control = control;
752 msg.msg_controllen = sizeof(control);
753 memset(buf, 0, sizeof(buf));
754 ret = recvmsg(afs_socket, &msg, 0);
755 if (ret < 0)
756 return -ERRNO_TO_PARA_ERROR(errno);
757 if (iov.iov_len != sizeof(buf))
758 return -E_AFS_SHORT_READ;
759 *code = *(uint32_t*)buf;
760 *data = *(uint32_t*)(buf + 4);
761 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
762 if (cmsg->cmsg_level != SOL_SOCKET
763 || cmsg->cmsg_type != SCM_RIGHTS)
764 continue;
765 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
766 continue;
767 *fd = *(int *)CMSG_DATA(cmsg);
768 }
769 return 1;
770 }
771
772 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
773 {
774 int ret, passed_fd, shmid;
775 uint32_t afs_code = 0, afs_data = 0;
776 struct stat statbuf;
777
778 if (!FD_ISSET(vsst->afs_socket, rfds))
779 return;
780 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
781 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
782 return;
783 if (ret < 0)
784 goto err;
785 vsst->afsss = AFS_SOCKET_READY;
786 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
787 afs_data);
788 ret = -E_NOFD;
789 if (afs_code != NEXT_AUDIO_FILE)
790 goto err;
791 if (passed_fd < 0)
792 goto err;
793 shmid = afs_data;
794 ret = load_afd(shmid, &mmd->afd);
795 if (ret < 0)
796 goto err;
797 shm_destroy(shmid);
798 ret = fstat(passed_fd, &statbuf);
799 if (ret < 0) {
800 PARA_ERROR_LOG("fstat error:\n");
801 ret = -ERRNO_TO_PARA_ERROR(errno);
802 goto err;
803 }
804 mmd->size = statbuf.st_size;
805 mmd->mtime = statbuf.st_mtime;
806 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE, passed_fd,
807 0, &vsst->map);
808 if (ret < 0)
809 goto err;
810 close(passed_fd);
811 mmd->chunks_sent = 0;
812 mmd->current_chunk = 0;
813 mmd->offset = 0;
814 mmd->events++;
815 mmd->num_played++;
816 mmd->new_vss_status_flags &= (~VSS_NEXT);
817 afh_get_header(&mmd->afd.afhi, vsst->map, &vsst->header_buf,
818 &vsst->header_len);
819 return;
820 err:
821 free(mmd->afd.afhi.chunk_table);
822 if (passed_fd >= 0)
823 close(passed_fd);
824 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
825 mmd->new_vss_status_flags = VSS_NEXT;
826 }
827
828 static int initialize_fec_client(struct fec_client *fc)
829 {
830 int ret;
831 struct fec_client_parms *fcp = fc->fcp;
832
833 if (fcp->init_fec) {
834 /*
835 * Set the maximum slice size to the Maximum Packet Size if the
836 * transport protocol allows to determine this value. The user
837 * can specify a slice size up to this value.
838 */
839 ret = fcp->init_fec(fc->sc);
840 if (ret < 0)
841 return ret;
842 if (!fcp->max_slice_bytes || fcp->max_slice_bytes > ret)
843 fcp->max_slice_bytes = ret;
844 }
845 if (fcp->max_slice_bytes < FEC_HEADER_SIZE + fcp->data_slices_per_group)
846 return -ERRNO_TO_PARA_ERROR(EINVAL);
847 ret = fec_new(fcp->data_slices_per_group, fcp->slices_per_group,
848 &fc->parms);
849 if (ret < 0)
850 goto err;
851 fc->first_stream_chunk = -1; /* stream not yet started */
852 fc->src_data = para_malloc(fc->fcp->slices_per_group * sizeof(char *));
853 fc->enc_buf = para_calloc(fc->fcp->max_slice_bytes);
854 fc->num_extra_slices = 0;
855 fc->extra_src_buf = para_calloc(fc->fcp->max_slice_bytes);
856 fc->next_header_time.tv_sec = 0;
857 fc->ready = true;
858 return 1;
859 err:
860 fec_free(fc->parms);
861 return ret;
862 }
863
864 /**
865 * Main sending function.
866 *
867 * This function gets called from vss_post_select(). It checks whether the next
868 * chunk of data should be pushed out. It obtains a pointer to the data to be
869 * sent out as well as its length from mmd->afd.afhi. This information is then
870 * passed to each supported sender's send() function as well as to the send()
871 * functions of each registered fec client.
872 */
873 static void vss_send(struct vss_task *vsst)
874 {
875 int ret, i, fec_active = 0;
876 struct timeval due;
877 struct fec_client *fc, *tmp_fc;
878
879 if (!vsst->map || !vss_playing())
880 return;
881 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
882 return;
883 if (chk_barrier("data send", &vsst->data_send_barrier,
884 &due, 1) < 0)
885 return;
886 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
887 if (fc->error < 0)
888 continue;
889 if (!fc->ready) {
890 ret = initialize_fec_client(fc);
891 if (ret < 0) {
892 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
893 continue;
894 }
895 }
896 if (!next_slice_is_due(fc, NULL)) {
897 fec_active = 1;
898 continue;
899 }
900 if (compute_next_fec_slice(fc, vsst) <= 0)
901 continue;
902 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
903 fc->current_slice_num, fc->fcp->max_slice_bytes);
904 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
905 fc->fcp->max_slice_bytes);
906 fc->current_slice_num++;
907 fec_active = 1;
908 }
909 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
910 if (!fec_active)
911 mmd->new_vss_status_flags |= VSS_NEXT;
912 return;
913 }
914 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
915 &mmd->stream_start, &due);
916 if (tv_diff(&due, now, NULL) <= 0) {
917 const char *buf;
918 size_t len;
919
920 if (!mmd->chunks_sent) {
921 mmd->stream_start = *now;
922 mmd->events++;
923 set_mmd_offset();
924 }
925 /*
926 * We call the send function also in case of empty chunks as
927 * they might have still some data queued which can be sent in
928 * this case.
929 */
930 afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, vsst->map,
931 &buf, &len);
932 for (i = 0; senders[i].name; i++) {
933 if (!senders[i].send)
934 continue;
935 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
936 buf, len, vsst->header_buf, vsst->header_len);
937 }
938 mmd->chunks_sent++;
939 mmd->current_chunk++;
940 }
941 }
942
943 static void vss_post_select(struct sched *s, struct task *t)
944 {
945 int ret, i;
946 struct vss_task *vsst = container_of(t, struct vss_task, task);
947
948
949 if (mmd->sender_cmd_data.cmd_num >= 0) {
950 int num = mmd->sender_cmd_data.cmd_num,
951 sender_num = mmd->sender_cmd_data.sender_num;
952
953 if (senders[sender_num].client_cmds[num])
954 senders[sender_num].client_cmds[num](&mmd->sender_cmd_data);
955 mmd->sender_cmd_data.cmd_num = -1;
956 }
957 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
958 recv_afs_result(vsst, &s->rfds);
959 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
960 PARA_NOTICE_LOG("requesting new fd from afs\n");
961 ret = send_buffer(vsst->afs_socket, "new");
962 if (ret < 0)
963 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
964 else
965 vsst->afsss = AFS_SOCKET_AFD_PENDING;
966 }
967 for (i = 0; senders[i].name; i++) {
968 if (!senders[i].post_select)
969 continue;
970 senders[i].post_select(&s->rfds, &s->wfds);
971 }
972 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
973 (vss_next() && vss_playing()))
974 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
975 vss_send(vsst);
976 }
977
978 /**
979 * Initialize the virtual streaming system task.
980 *
981 * \param afs_socket The fd for communication with afs.
982 *
983 * This also initializes all supported senders and starts streaming
984 * if the --autoplay command line flag was given.
985 */
986 void init_vss_task(int afs_socket)
987 {
988 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
989 int i;
990 char *hn = para_hostname(), *home = para_homedir();
991 long unsigned announce_time = conf.announce_time_arg > 0?
992 conf.announce_time_arg : 300,
993 autoplay_delay = conf.autoplay_delay_arg > 0?
994 conf.autoplay_delay_arg : 0;
995 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
996 vsst->afs_socket = afs_socket;
997 vsst->task.pre_select = vss_pre_select;
998 vsst->task.post_select = vss_post_select;
999 ms2tv(announce_time, &vsst->announce_tv);
1000 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1001 INIT_LIST_HEAD(&fec_client_list);
1002 for (i = 0; senders[i].name; i++) {
1003 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1004 senders[i].init(&senders[i]);
1005 }
1006 free(hn);
1007 free(home);
1008 mmd->sender_cmd_data.cmd_num = -1;
1009 if (conf.autoplay_given) {
1010 struct timeval tmp;
1011 mmd->vss_status_flags |= VSS_PLAYING;
1012 mmd->new_vss_status_flags |= VSS_PLAYING;
1013 ms2tv(autoplay_delay, &tmp);
1014 tv_add(now, &tmp, &vsst->autoplay_barrier);
1015 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1016 &vsst->data_send_barrier);
1017 }
1018 register_task(&vsst->task);
1019 }