server: Rename init_vss_task() to vss_init().
[paraslash.git] / vss.c
1 /*
2 * Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>
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 <sys/socket.h>
15 #include <netinet/in.h>
16 #include <regex.h>
17 #include <osl.h>
18 #include <sys/types.h>
19 #include <arpa/inet.h>
20 #include <sys/un.h>
21 #include <netdb.h>
22 #include <lopsub.h>
23
24 #include "server.lsg.h"
25 #include "para.h"
26 #include "error.h"
27 #include "portable_io.h"
28 #include "fec.h"
29 #include "string.h"
30 #include "afh.h"
31 #include "afs.h"
32 #include "server.h"
33 #include "net.h"
34 #include "list.h"
35 #include "send.h"
36 #include "sched.h"
37 #include "vss.h"
38 #include "ipc.h"
39 #include "fd.h"
40
41 extern struct misc_meta_data *mmd;
42
43 extern void dccp_send_init(struct sender *);
44 extern void http_send_init(struct sender *);
45 extern void udp_send_init(struct sender *);
46
47 /** The list of supported senders. */
48 struct sender senders[] = {
49 {
50 .name = "http",
51 .init = http_send_init,
52 },
53 {
54 .name = "dccp",
55 .init = dccp_send_init,
56 },
57 {
58 .name = "udp",
59 .init = udp_send_init,
60 },
61 {
62 .name = NULL,
63 }
64 };
65
66 /** The possible states of the afs socket. */
67 enum afs_socket_status {
68 /** Socket is inactive. */
69 AFS_SOCKET_READY,
70 /** Socket fd was included in the write fd set for select(). */
71 AFS_SOCKET_CHECK_FOR_WRITE,
72 /** vss wrote a request to the socket and waits for reply from afs. */
73 AFS_SOCKET_AFD_PENDING
74 };
75
76 /** The task structure for the virtual streaming system. */
77 struct vss_task {
78 /** Copied from the -announce_time command line option. */
79 struct timeval announce_tv;
80 /** End of the announcing interval. */
81 struct timeval data_send_barrier;
82 /** End of the EOF interval. */
83 struct timeval eof_barrier;
84 /** Only used if --autoplay_delay was given. */
85 struct timeval autoplay_barrier;
86 /** Used for afs-server communication. */
87 int afs_socket;
88 /** The current state of \a afs_socket. */
89 enum afs_socket_status afsss;
90 /** The memory mapped audio file. */
91 char *map;
92 /** The size of the memory mapping. */
93 size_t mapsize;
94 /** Used by the scheduler. */
95 struct task *task;
96 /** Pointer to the header of the mapped audio file. */
97 char *header_buf;
98 /** Length of the audio file header. */
99 size_t header_len;
100 /** Time between audio file headers are sent. */
101 struct timeval header_interval;
102 /* Only used if afh supports dynamic chunks. */
103 void *afh_context;
104 };
105
106 /**
107 * The list of currently connected fec clients.
108 *
109 * Senders may use \ref vss_add_fec_client() to add entries to the list.
110 */
111 static struct list_head fec_client_list;
112
113 /**
114 * Data associated with one FEC group.
115 *
116 * A FEC group consists of a fixed number of slices and this number is given by
117 * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
118 * group contains a number of chunks of the current audio file.
119 *
120 * FEC slices directly correspond to the data packages sent by the paraslash
121 * senders that use FEC. Each slice is identified by its group number and its
122 * number within the group. All slices have the same size, but the last slice
123 * of the group may not be filled entirely.
124 */
125 struct fec_group {
126 /** The number of the FEC group. */
127 uint32_t num;
128 /** Number of bytes in this group. */
129 uint32_t bytes;
130 /** The first chunk of the current audio file belonging to the group. */
131 uint32_t first_chunk;
132 /** The number of chunks contained in this group. */
133 uint32_t num_chunks;
134 /** When the first chunk was sent. */
135 struct timeval start;
136 /** The duration of the full group. */
137 struct timeval duration;
138 /** The group duration divided by the number of slices. */
139 struct timeval slice_duration;
140 /** Group contains the audio file header that occupies that many slices. */
141 uint8_t num_header_slices;
142 /** Number of bytes per slice for this group. */
143 uint16_t slice_bytes;
144 };
145
146 /** A FEC client is always in one of these states. */
147 enum fec_client_state {
148 FEC_STATE_NONE = 0, /**< not initialized and not enabled */
149 FEC_STATE_DISABLED, /**< temporarily disabled */
150 FEC_STATE_READY_TO_RUN /**< initialized and enabled */
151 };
152
153 /**
154 * Describes one connected FEC client.
155 */
156 struct fec_client {
157 /** Current state of the client */
158 enum fec_client_state state;
159 /** The connected sender client (transport layer). */
160 struct sender_client *sc;
161 /** Parameters requested by the client. */
162 struct fec_client_parms *fcp;
163 /** Used by the core FEC code. */
164 struct fec_parms *parms;
165 /** The position of this client in the fec client list. */
166 struct list_head node;
167 /** When the first slice for this client was sent. */
168 struct timeval stream_start;
169 /** The first chunk sent to this FEC client. */
170 int first_stream_chunk;
171 /** Describes the current group. */
172 struct fec_group group;
173 /** The current slice. */
174 uint8_t current_slice_num;
175 /** The data to be FEC-encoded (point to a region within the mapped audio file). */
176 const unsigned char **src_data;
177 /** Last time an audio header was sent. */
178 struct timeval next_header_time;
179 /** Used for the last source pointer of an audio file. */
180 unsigned char *extra_src_buf;
181 /** Needed for the last slice of the audio file header. */
182 unsigned char *extra_header_buf;
183 /** Extra slices needed to store largest chunk + header. */
184 int num_extra_slices;
185 /** Contains the FEC-encoded data. */
186 unsigned char *enc_buf;
187 /** Maximal packet size. */
188 int mps;
189 };
190
191 /**
192 * Get the chunk time of the current audio file.
193 *
194 * \return A pointer to a struct containing the chunk time, or NULL,
195 * if currently no audio file is selected.
196 */
197 struct timeval *vss_chunk_time(void)
198 {
199 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
200 mmd->afd.afhi.chunk_tv.tv_usec == 0)
201 return NULL;
202 return &mmd->afd.afhi.chunk_tv;
203 }
204
205 /**
206 * Write a fec header to a buffer.
207 *
208 * \param buf The buffer to write to.
209 * \param h The fec header to write.
210 */
211 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
212 {
213 char *buf = (char *)fc->enc_buf;
214 struct fec_group *g = &fc->group;
215 struct fec_client_parms *p = fc->fcp;
216
217 write_u32(buf, FEC_MAGIC);
218
219 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
220 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
221 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
222
223 write_u32(buf + 10, g->num);
224 write_u32(buf + 14, g->bytes);
225
226 write_u8(buf + 18, fc->current_slice_num);
227 write_u8(buf + 19, 0); /* unused */
228 write_u16(buf + 20, g->slice_bytes);
229 write_u8(buf + 22, g->first_chunk? 0 : 1);
230 write_u8(buf + 23, vsst->header_len? 1 : 0);
231 memset(buf + 24, 0, 8);
232 }
233
234 static bool need_audio_header(struct fec_client *fc, struct vss_task *vsst)
235 {
236 if (!mmd->current_chunk) {
237 tv_add(now, &vsst->header_interval, &fc->next_header_time);
238 return false;
239 }
240 if (!vsst->header_buf)
241 return false;
242 if (vsst->header_len == 0)
243 return false;
244 if (fc->group.num > 0) {
245 if (!fc->fcp->need_periodic_header)
246 return false;
247 if (tv_diff(&fc->next_header_time, now, NULL) > 0)
248 return false;
249 }
250 tv_add(now, &vsst->header_interval, &fc->next_header_time);
251 return true;
252 }
253
254 static bool need_data_slices(struct fec_client *fc, struct vss_task *vsst)
255 {
256 if (fc->group.num > 0)
257 return true;
258 if (!vsst->header_buf)
259 return true;
260 if (vsst->header_len == 0)
261 return true;
262 if (fc->fcp->need_periodic_header)
263 return true;
264 return false;
265 }
266
267 static int num_slices(long unsigned bytes, int max_payload, int rs)
268 {
269 int ret;
270
271 assert(max_payload > 0);
272 assert(rs > 0);
273 ret = DIV_ROUND_UP(bytes, max_payload);
274 if (ret + rs > 255)
275 return -E_BAD_CT;
276 return ret;
277 }
278
279 /* set group start and group duration */
280 static void set_group_timing(struct fec_client *fc, struct vss_task *vsst)
281 {
282 struct fec_group *g = &fc->group;
283 struct timeval *chunk_tv = vss_chunk_time();
284
285 if (!need_data_slices(fc, vsst))
286 ms2tv(200, &g->duration);
287 else
288 tv_scale(g->num_chunks, chunk_tv, &g->duration);
289 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
290 &g->duration, &g->slice_duration);
291 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
292 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
293 }
294
295 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
296 {
297 int k, n, ret;
298 int hs, ds, rs; /* header/data/redundant slices */
299 struct fec_client_parms *fcp = fc->fcp;
300
301 /* set mps */
302 if (fcp->init_fec) {
303 /*
304 * Set the maximum slice size to the Maximum Packet Size if the
305 * transport protocol allows to determine this value. The user
306 * can specify a slice size up to this value.
307 */
308 ret = fcp->init_fec(fc->sc);
309 if (ret < 0)
310 return ret;
311 fc->mps = ret;
312 } else
313 fc->mps = generic_max_transport_msg_size(fc->sc->fd);
314 if (fc->mps <= FEC_HEADER_SIZE)
315 return -ERRNO_TO_PARA_ERROR(EINVAL);
316
317 rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
318 ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
319 if (ret < 0)
320 return ret;
321 hs = ret;
322 ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
323 if (ret < 0)
324 return ret;
325 ds = ret;
326 if (fc->fcp->need_periodic_header)
327 k = hs + ds;
328 else
329 k = PARA_MAX(hs, ds);
330 if (k < fc->fcp->data_slices_per_group)
331 k = fc->fcp->data_slices_per_group;
332 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
333 n = k + rs;
334 fec_free(fc->parms);
335 ret = fec_new(k, n, &fc->parms);
336 if (ret < 0)
337 return ret;
338 PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
339 fc->mps, k, n, fc->num_extra_slices);
340 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
341 fc->enc_buf = para_realloc(fc->enc_buf, fc->mps);
342 fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->mps);
343 fc->extra_header_buf = para_realloc(fc->extra_header_buf, fc->mps);
344
345 fc->state = FEC_STATE_READY_TO_RUN;
346 fc->next_header_time.tv_sec = 0;
347 fc->stream_start = *now;
348 fc->first_stream_chunk = mmd->current_chunk;
349 return 1;
350 }
351
352 static void vss_get_chunk(int chunk_num, struct vss_task *vsst,
353 char **buf, size_t *sz)
354 {
355 int ret;
356
357 /*
358 * Chunk zero is special for header streams: It is the first portion of
359 * the audio file which consists of the audio file header. It may be
360 * arbitrary large due to embedded meta data. Audio format handlers may
361 * replace the header by a stripped one with meta data omitted which is
362 * of bounded size. We always use the stripped header for streaming
363 * rather than the unmodified header (chunk zero).
364 */
365 if (chunk_num == 0 && vsst->header_len > 0) {
366 assert(vsst->header_buf);
367 *buf = vsst->header_buf; /* stripped header */
368 *sz = vsst->header_len;
369 return;
370 }
371 ret = afh_get_chunk(chunk_num, &mmd->afd.afhi,
372 mmd->afd.audio_format_id, vsst->map, vsst->mapsize,
373 (const char **)buf, sz, &vsst->afh_context);
374 if (ret < 0) {
375 PARA_WARNING_LOG("could not get chunk %d: %s\n",
376 chunk_num, para_strerror(-ret));
377 *buf = NULL;
378 *sz = 0;
379 }
380 }
381
382 static void compute_group_size(struct vss_task *vsst, struct fec_group *g,
383 int max_bytes)
384 {
385 char *buf;
386 size_t len;
387 int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
388
389 if (g->first_chunk == 0) {
390 g->num_chunks = 1;
391 vss_get_chunk(0, vsst, &buf, &len);
392 g->bytes = len;
393 return;
394 }
395
396 g->num_chunks = 0;
397 g->bytes = 0;
398 /*
399 * Include chunks into the group until the group duration is at least
400 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
401 * super frame) is already larger than 150ms, so a FEC group consists
402 * of exactly one chunk for these audio formats.
403 */
404 for (i = 0;; i++) {
405 int chunk_num = g->first_chunk + i;
406
407 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
408 break;
409 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
410 break;
411 vss_get_chunk(chunk_num, vsst, &buf, &len);
412 if (g->bytes + len > max_bytes)
413 break;
414 /* Include this chunk */
415 g->bytes += len;
416 g->num_chunks++;
417 }
418 assert(g->num_chunks);
419 }
420
421 /*
422 * Compute the slice size of the next group.
423 *
424 * The FEC parameters n and k are fixed but the slice size varies per
425 * FEC group. We'd like to choose slices as small as possible to avoid
426 * unnecessary FEC calculations but large enough to guarantee that the
427 * k data slices suffice to encode the header (if needed) and the data
428 * chunk(s).
429 *
430 * Once we know the payload of the next group, we define the number s
431 * of bytes per slice for this group by
432 *
433 * s = ceil(payload / k)
434 *
435 * However, for header streams, computing s is more complicated since no
436 * overlapping of header and data slices is possible. Hence we have k >=
437 * 2 and s must satisfy
438 *
439 * (*) ceil(h / s) + ceil(d / s) <= k
440 *
441 * where h and d are payload of the header and the data chunk(s)
442 * respectively. In general there is no value for s such that (*)
443 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
444 *
445 * We use the following approach for computing a suitable value for s:
446 *
447 * Let
448 * k1 := ceil(k * min(h, d) / (h + d)),
449 * k2 := k - k1.
450 *
451 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
452 *
453 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
454 *
455 * is well-defined. Inequality (*) holds for this value of s since k1
456 * slices suffice to store min(h, d) while k2 slices suffice to store
457 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
458 * second by k2.
459 *
460 * For the above example we obtain
461 *
462 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
463 * s = max(4000 / 5, 5000 / 5) = 1000,
464 *
465 * which is optimal since a slice size of 999 bytes would already require
466 * 11 slices.
467 */
468 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
469 {
470 struct fec_group *g = &fc->group;
471 int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
472 int n = fc->fcp->slices_per_group + fc->num_extra_slices;
473 int ret, k1, k2, h, d, min, max, sum;
474 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
475 int max_group_bytes;
476
477 if (!need_audio_header(fc, vsst)) {
478 max_group_bytes = k * max_slice_bytes;
479 g->num_header_slices = 0;
480 compute_group_size(vsst, g, max_group_bytes);
481 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
482 if (g->slice_bytes == 0)
483 g->slice_bytes = 1;
484 return 1;
485 }
486 if (!need_data_slices(fc, vsst)) {
487 g->bytes = 0;
488 g->num_chunks = 0;
489 g->slice_bytes = DIV_ROUND_UP(vsst->header_len, k);
490 g->num_header_slices = k;
491 return 1;
492 }
493 h = vsst->header_len;
494 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
495 * max_slice_bytes;
496 compute_group_size(vsst, g, max_group_bytes);
497 d = g->bytes;
498 if (d == 0) {
499 g->slice_bytes = DIV_ROUND_UP(h, k);
500 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
501 if (ret < 0)
502 return ret;
503 g->num_header_slices = ret;
504 return 1;
505 }
506 min = PARA_MIN(h, d);
507 max = PARA_MAX(h, d);
508 sum = h + d;
509 k1 = DIV_ROUND_UP(k * min, sum);
510 k2 = k - k1;
511 assert(k1 > 0);
512 assert(k2 > 0);
513
514 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
515 /*
516 * This value of s := g->slice_bytes satisfies inequality (*) above,
517 * but it might be larger than max_slice_bytes. However, we know that
518 * max_slice_bytes are sufficient to store header and data, so:
519 */
520 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
521
522 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
523 if (ret < 0)
524 return ret;
525 g->num_header_slices = ret;
526 return 1;
527 }
528
529 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
530 {
531 int ret, i, k, n, data_slices;
532 size_t len;
533 char *buf, *p;
534 struct fec_group *g = &fc->group;
535
536 if (fc->state == FEC_STATE_NONE) {
537 ret = initialize_fec_client(fc, vsst);
538 if (ret < 0)
539 return ret;
540 g->first_chunk = mmd->current_chunk;
541 g->num = 0;
542 g->start = *now;
543 } else {
544 struct timeval tmp;
545 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
546 return 0;
547 /*
548 * Start and duration of this group depend only on the previous
549 * group. Compute the new group start as g->start += g->duration.
550 */
551 tmp = g->start;
552 tv_add(&tmp, &g->duration, &g->start);
553 set_group_timing(fc, vsst);
554 g->first_chunk += g->num_chunks;
555 g->num++;
556 }
557 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
558 n = fc->fcp->slices_per_group + fc->num_extra_slices;
559
560 compute_slice_size(fc, vsst);
561 assert(g->slice_bytes > 0);
562 ret = num_slices(g->bytes, g->slice_bytes, n - k);
563 if (ret < 0)
564 return ret;
565 data_slices = ret;
566 assert(g->num_header_slices + data_slices <= k);
567 fc->current_slice_num = 0;
568 if (g->num == 0)
569 set_group_timing(fc, vsst);
570 /* setup header slices */
571 buf = vsst->header_buf;
572 for (i = 0; i < g->num_header_slices; i++) {
573 uint32_t payload_size;
574 if (buf + g->slice_bytes <= vsst->header_buf + vsst->header_len) {
575 fc->src_data[i] = (const unsigned char *)buf;
576 buf += g->slice_bytes;
577 continue;
578 }
579 /*
580 * Can not use vss->header_buf for this slice as it
581 * goes beyond the buffer. This slice will not be fully
582 * used.
583 */
584 payload_size = vsst->header_buf + vsst->header_len - buf;
585 memcpy(fc->extra_header_buf, buf, payload_size);
586 if (payload_size < g->slice_bytes)
587 memset(fc->extra_header_buf + payload_size, 0,
588 g->slice_bytes - payload_size);
589 /*
590 * There might be more than one header slice to fill although
591 * only the first one will be used. Set all header slices to
592 * our extra buffer.
593 */
594 while (i < g->num_header_slices)
595 fc->src_data[i++] = fc->extra_header_buf;
596 break; /* we don't want i to be increased. */
597 }
598
599 /*
600 * Setup data slices. Note that for ogg streams chunk 0 points to a
601 * buffer on the heap rather than to the mapped audio file.
602 */
603 vss_get_chunk(g->first_chunk, vsst, &buf, &len);
604 for (p = buf; i < g->num_header_slices + data_slices; i++) {
605 if (p + g->slice_bytes > buf + g->bytes) {
606 /*
607 * We must make a copy for this slice since using p
608 * directly would exceed the buffer.
609 */
610 uint32_t payload_size = buf + g->bytes - p;
611 assert(payload_size + FEC_HEADER_SIZE <= fc->mps);
612 memcpy(fc->extra_src_buf, p, payload_size);
613 if (payload_size < g->slice_bytes)
614 memset(fc->extra_src_buf + payload_size, 0,
615 g->slice_bytes - payload_size);
616 fc->src_data[i] = fc->extra_src_buf;
617 i++;
618 break;
619 }
620 fc->src_data[i] = (const unsigned char *)p;
621 p += g->slice_bytes;
622 }
623 if (i < k) {
624 /* use arbitrary data for all remaining slices */
625 buf = vsst->map;
626 for (; i < k; i++)
627 fc->src_data[i] = (const unsigned char *)buf;
628 }
629 PARA_DEBUG_LOG("FEC group %u: %u chunks (%u - %u), %u bytes\n",
630 g->num, g->num_chunks, g->first_chunk,
631 g->first_chunk + g->num_chunks - 1, g->bytes
632 );
633 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
634 g->slice_bytes, g->num_header_slices, data_slices
635 );
636 return 1;
637 }
638
639 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
640 {
641 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
642 == fc->fcp->slices_per_group + fc->num_extra_slices) {
643 int ret = setup_next_fec_group(fc, vsst);
644 if (ret == 0)
645 return 0;
646 if (ret < 0) {
647 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
648 PARA_ERROR_LOG("FEC client temporarily disabled\n");
649 fc->state = FEC_STATE_DISABLED;
650 return ret;
651 }
652 }
653 write_fec_header(fc, vsst);
654 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
655 fc->current_slice_num, fc->group.slice_bytes);
656 return 1;
657 }
658
659 /**
660 * Return a buffer that marks the end of the stream.
661 *
662 * \param buf Result pointer.
663 * \return The length of the eof buffer.
664 *
665 * This is used for (multicast) udp streaming where closing the socket on the
666 * sender might not give rise to an eof condition at the peer.
667 */
668 size_t vss_get_fec_eof_packet(const char **buf)
669 {
670 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
671 *buf = fec_eof_packet;
672 return FEC_HEADER_SIZE;
673 }
674
675 /**
676 * Add one entry to the list of active fec clients.
677 *
678 * \param sc Generic sender_client data of the transport layer.
679 * \param fcp FEC parameters as supplied by the transport layer.
680 *
681 * \return Newly allocated fec_client struct.
682 */
683 struct fec_client *vss_add_fec_client(struct sender_client *sc,
684 struct fec_client_parms *fcp)
685 {
686 struct fec_client *fc = para_calloc(sizeof(*fc));
687
688 fc->sc = sc;
689 fc->fcp = fcp;
690 para_list_add(&fc->node, &fec_client_list);
691 return fc;
692 }
693
694 /**
695 * Remove one entry from the list of active fec clients.
696 *
697 * \param fc The client to be removed.
698 */
699 void vss_del_fec_client(struct fec_client *fc)
700 {
701 list_del(&fc->node);
702 free(fc->src_data);
703 free(fc->enc_buf);
704 free(fc->extra_src_buf);
705 free(fc->extra_header_buf);
706 fec_free(fc->parms);
707 free(fc);
708 }
709
710 /*
711 * Compute if/when next slice is due. If it isn't due yet and \a diff is
712 * not \p Null, compute the time difference next - now, where
713 *
714 * next = stream_start + (first_group_chunk - first_stream_chunk)
715 * * chunk_time + slice_num * slice_time
716 */
717 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
718 {
719 struct timeval tmp, next;
720 int ret;
721
722 if (fc->state == FEC_STATE_NONE)
723 return 1;
724 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
725 tv_add(&tmp, &fc->group.start, &next);
726 ret = tv_diff(&next, now, diff);
727 return ret < 0? 1 : 0;
728 }
729
730 static void set_eof_barrier(struct vss_task *vsst)
731 {
732 struct fec_client *fc;
733 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
734
735 if (!chunk_tv)
736 goto out;
737 list_for_each_entry(fc, &fec_client_list, node) {
738 struct timeval group_duration;
739
740 if (fc->state != FEC_STATE_READY_TO_RUN)
741 continue;
742 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
743 if (tv_diff(&timeout, &group_duration, NULL) < 0)
744 timeout = group_duration;
745 }
746 out:
747 tv_add(now, &timeout, &vsst->eof_barrier);
748 }
749
750 /**
751 * Check if vss status flag \a P (playing) is set.
752 *
753 * \return Greater than zero if playing, zero otherwise.
754 *
755 */
756 unsigned int vss_playing(void)
757 {
758 return mmd->new_vss_status_flags & VSS_PLAYING;
759 }
760
761 /**
762 * Check if the \a N (next) status flag is set.
763 *
764 * \return Greater than zero if set, zero if not.
765 *
766 */
767 unsigned int vss_next(void)
768 {
769 return mmd->new_vss_status_flags & VSS_NEXT;
770 }
771
772 /**
773 * Check if a reposition request is pending.
774 *
775 * \return Greater than zero if true, zero otherwise.
776 *
777 */
778 unsigned int vss_repos(void)
779 {
780 return mmd->new_vss_status_flags & VSS_REPOS;
781 }
782
783 /**
784 * Check if the vss is currently paused.
785 *
786 * \return Greater than zero if paused, zero otherwise.
787 *
788 */
789 unsigned int vss_paused(void)
790 {
791 return !(mmd->new_vss_status_flags & VSS_NEXT)
792 && !(mmd->new_vss_status_flags & VSS_PLAYING);
793 }
794
795 /**
796 * Check if the vss is currently stopped.
797 *
798 * \return Greater than zero if paused, zero otherwise.
799 *
800 */
801 unsigned int vss_stopped(void)
802 {
803 return (mmd->new_vss_status_flags & VSS_NEXT)
804 && !(mmd->new_vss_status_flags & VSS_PLAYING);
805 }
806
807 static int chk_barrier(const char *bname, const struct timeval *barrier,
808 struct timeval *diff, int print_log)
809 {
810 long ms;
811
812 if (tv_diff(now, barrier, diff) > 0)
813 return 1;
814 ms = tv2ms(diff);
815 if (print_log && ms)
816 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
817 return -1;
818 }
819
820 static void vss_compute_timeout(struct sched *s, struct vss_task *vsst)
821 {
822 struct timeval tv;
823 struct fec_client *fc;
824
825 if (!vss_playing() || !vsst->map)
826 return;
827 if (vss_next() && vsst->map) /* only sleep a bit, nec*/
828 return sched_request_timeout_ms(100, s);
829
830 /* Each of these barriers must have passed until we may proceed */
831 if (sched_request_barrier(&vsst->autoplay_barrier, s) == 1)
832 return;
833 if (sched_request_barrier(&vsst->eof_barrier, s) == 1)
834 return;
835 if (sched_request_barrier(&vsst->data_send_barrier, s) == 1)
836 return;
837 /*
838 * Compute the select timeout as the minimal time until the next
839 * chunk/slice is due for any client.
840 */
841 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
842 &mmd->stream_start, &tv);
843 if (sched_request_barrier_or_min_delay(&tv, s) == 0)
844 return;
845 list_for_each_entry(fc, &fec_client_list, node) {
846 if (fc->state != FEC_STATE_READY_TO_RUN)
847 continue;
848 if (next_slice_is_due(fc, &tv))
849 return sched_min_delay(s);
850 sched_request_timeout(&tv, s);
851 }
852 }
853
854 static void vss_eof(struct vss_task *vsst)
855 {
856
857 if (!vsst->map)
858 return;
859 if (mmd->new_vss_status_flags & VSS_NOMORE)
860 mmd->new_vss_status_flags = VSS_NEXT;
861 set_eof_barrier(vsst);
862 afh_free_header(vsst->header_buf, mmd->afd.audio_format_id);
863 vsst->header_buf = NULL;
864 para_munmap(vsst->map, vsst->mapsize);
865 vsst->map = NULL;
866 mmd->chunks_sent = 0;
867 //mmd->offset = 0;
868 mmd->afd.afhi.seconds_total = 0;
869 mmd->afd.afhi.chunk_tv.tv_sec = 0;
870 mmd->afd.afhi.chunk_tv.tv_usec = 0;
871 free(mmd->afd.afhi.chunk_table);
872 mmd->afd.afhi.chunk_table = NULL;
873 vsst->mapsize = 0;
874 afh_close(vsst->afh_context, mmd->afd.audio_format_id);
875 vsst->afh_context = NULL;
876 mmd->events++;
877 }
878
879 static int need_to_request_new_audio_file(struct vss_task *vsst)
880 {
881 struct timeval diff;
882
883 if (vsst->map) /* have audio file */
884 return 0;
885 if (!vss_playing()) /* don't need one */
886 return 0;
887 if (mmd->new_vss_status_flags & VSS_NOMORE)
888 return 0;
889 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
890 return 0;
891 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
892 &diff, 1) < 0)
893 return 0;
894 return 1;
895 }
896
897 static void set_mmd_offset(void)
898 {
899 struct timeval offset;
900 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
901 mmd->offset = tv2ms(&offset);
902 }
903
904 static void vss_pre_select(struct sched *s, void *context)
905 {
906 int i;
907 struct vss_task *vsst = context;
908
909 if (need_to_request_new_audio_file(vsst)) {
910 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
911 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
912 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
913 } else
914 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
915 for (i = 0; senders[i].name; i++) {
916 if (!senders[i].pre_select)
917 continue;
918 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
919 }
920 vss_compute_timeout(s, vsst);
921 }
922
923 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
924 {
925 char control[255] __a_aligned(8), buf[8];
926 struct msghdr msg = {.msg_iov = NULL};
927 struct cmsghdr *cmsg;
928 struct iovec iov;
929 int ret = 0;
930
931 *fd = -1;
932 iov.iov_base = buf;
933 iov.iov_len = sizeof(buf);
934 msg.msg_iov = &iov;
935 msg.msg_iovlen = 1;
936 msg.msg_control = control;
937 msg.msg_controllen = sizeof(control);
938 memset(buf, 0, sizeof(buf));
939 ret = recvmsg(afs_socket, &msg, 0);
940 if (ret < 0)
941 return -ERRNO_TO_PARA_ERROR(errno);
942 if (iov.iov_len != sizeof(buf))
943 return -E_AFS_SHORT_READ;
944 *code = *(uint32_t*)buf;
945 *data = *(uint32_t*)(buf + 4);
946 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
947 if (cmsg->cmsg_level != SOL_SOCKET
948 || cmsg->cmsg_type != SCM_RIGHTS)
949 continue;
950 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
951 continue;
952 *fd = *(int *)CMSG_DATA(cmsg);
953 }
954 return 1;
955 }
956
957 #ifndef MAP_POPULATE
958 #define MAP_POPULATE 0
959 #endif
960
961 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
962 {
963 int ret, passed_fd, shmid;
964 uint32_t afs_code = 0, afs_data = 0;
965 struct stat statbuf;
966
967 if (!FD_ISSET(vsst->afs_socket, rfds))
968 return;
969 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
970 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
971 return;
972 if (ret < 0)
973 goto err;
974 vsst->afsss = AFS_SOCKET_READY;
975 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
976 afs_data);
977 ret = -E_NOFD;
978 if (afs_code != NEXT_AUDIO_FILE)
979 goto err;
980 if (passed_fd < 0)
981 goto err;
982 shmid = afs_data;
983 ret = load_afd(shmid, &mmd->afd);
984 if (ret < 0)
985 goto err;
986 shm_destroy(shmid);
987 ret = fstat(passed_fd, &statbuf);
988 if (ret < 0) {
989 PARA_ERROR_LOG("fstat error:\n");
990 ret = -ERRNO_TO_PARA_ERROR(errno);
991 goto err;
992 }
993 ret = para_mmap(statbuf.st_size, PROT_READ, MAP_PRIVATE | MAP_POPULATE,
994 passed_fd, 0, &vsst->map);
995 if (ret < 0)
996 goto err;
997 vsst->mapsize = statbuf.st_size;
998 close(passed_fd);
999 mmd->chunks_sent = 0;
1000 mmd->current_chunk = 0;
1001 mmd->offset = 0;
1002 mmd->events++;
1003 mmd->num_played++;
1004 mmd->new_vss_status_flags &= (~VSS_NEXT);
1005 afh_get_header(&mmd->afd.afhi, mmd->afd.audio_format_id,
1006 vsst->map, vsst->mapsize, &vsst->header_buf, &vsst->header_len);
1007 return;
1008 err:
1009 free(mmd->afd.afhi.chunk_table);
1010 if (passed_fd >= 0)
1011 close(passed_fd);
1012 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1013 mmd->new_vss_status_flags = VSS_NEXT;
1014 }
1015
1016 /**
1017 * Main sending function.
1018 *
1019 * This function gets called from vss_post_select(). It checks whether the next
1020 * chunk of data should be pushed out. It obtains a pointer to the data to be
1021 * sent out as well as its length from mmd->afd.afhi. This information is then
1022 * passed to each supported sender's send() function as well as to the send()
1023 * functions of each registered fec client.
1024 */
1025 static void vss_send(struct vss_task *vsst)
1026 {
1027 int i;
1028 bool fec_active = false;
1029 struct timeval due;
1030 struct fec_client *fc, *tmp_fc;
1031
1032 if (!vsst->map || !vss_playing())
1033 return;
1034 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
1035 return;
1036 if (chk_barrier("data send", &vsst->data_send_barrier, &due, 1) < 0)
1037 return;
1038 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
1039 if (fc->state == FEC_STATE_DISABLED)
1040 continue;
1041 if (!next_slice_is_due(fc, NULL)) {
1042 fec_active = true;
1043 continue;
1044 }
1045 if (compute_next_fec_slice(fc, vsst) <= 0)
1046 continue;
1047 PARA_DEBUG_LOG("sending %u:%u (%u bytes)\n", fc->group.num,
1048 fc->current_slice_num, fc->group.slice_bytes);
1049 fc->current_slice_num++;
1050 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1051 fc->group.slice_bytes + FEC_HEADER_SIZE);
1052 fec_active = true;
1053 }
1054 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1055 if (!fec_active)
1056 mmd->new_vss_status_flags |= VSS_NEXT;
1057 return;
1058 }
1059 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1060 &mmd->stream_start, &due);
1061 if (tv_diff(&due, now, NULL) <= 0) {
1062 char *buf;
1063 size_t len;
1064
1065 if (!mmd->chunks_sent) {
1066 mmd->stream_start = *now;
1067 mmd->events++;
1068 set_mmd_offset();
1069 }
1070 vss_get_chunk(mmd->current_chunk, vsst, &buf, &len);
1071 for (i = 0; senders[i].name; i++) {
1072 /*
1073 * We call ->send() even if len is zero because senders
1074 * might have data queued which can be sent now.
1075 */
1076 if (!senders[i].send)
1077 continue;
1078 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1079 buf, len, vsst->header_buf, vsst->header_len);
1080 }
1081 /*
1082 * Prefault next chunk(s)
1083 *
1084 * If the backing device of the memory-mapped audio file is
1085 * slow and read-ahead is turned off or prevented for some
1086 * reason, e.g. due to memory pressure, it may take much longer
1087 * than the chunk interval to get the next chunk on the wire,
1088 * causing buffer underruns on the client side. Mapping the
1089 * file with MAP_POPULATE seems to help a bit, but it does not
1090 * eliminate the delays completely. Moreover, it is supported
1091 * only on Linux. So we do our own read-ahead here.
1092 */
1093 if (mmd->current_chunk > 0) { /* chunk 0 might be on the heap */
1094 buf += len;
1095 for (i = 0; i < 5 && buf < vsst->map + vsst->mapsize; i++) {
1096 __a_unused volatile char x = *buf;
1097 buf += 4096;
1098 }
1099 }
1100 mmd->chunks_sent++;
1101 mmd->current_chunk++;
1102 }
1103 }
1104
1105 static int vss_post_select(struct sched *s, void *context)
1106 {
1107 int ret, i;
1108 struct vss_task *vsst = context;
1109
1110 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
1111 /* shut down senders and fec clients */
1112 struct fec_client *fc, *tmp;
1113 for (i = 0; senders[i].name; i++)
1114 if (senders[i].shutdown_clients)
1115 senders[i].shutdown_clients();
1116 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
1117 fc->state = FEC_STATE_NONE;
1118 mmd->stream_start.tv_sec = 0;
1119 mmd->stream_start.tv_usec = 0;
1120 }
1121 if (vss_next())
1122 vss_eof(vsst);
1123 else if (vss_paused()) {
1124 if (mmd->chunks_sent)
1125 set_eof_barrier(vsst);
1126 mmd->chunks_sent = 0;
1127 } else if (vss_repos()) { /* repositioning due to ff/jmp command */
1128 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1129 set_eof_barrier(vsst);
1130 mmd->chunks_sent = 0;
1131 mmd->current_chunk = afh_get_start_chunk(mmd->repos_request,
1132 &mmd->afd.afhi, mmd->afd.audio_format_id);
1133 mmd->new_vss_status_flags &= ~VSS_REPOS;
1134 set_mmd_offset();
1135 }
1136 /* If a sender command is pending, run it. */
1137 if (mmd->sender_cmd_data.cmd_num >= 0) {
1138 int num = mmd->sender_cmd_data.cmd_num,
1139 sender_num = mmd->sender_cmd_data.sender_num;
1140
1141 if (senders[sender_num].client_cmds[num]) {
1142 ret = senders[sender_num].client_cmds[num]
1143 (&mmd->sender_cmd_data);
1144 if (ret < 0)
1145 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1146 }
1147 mmd->sender_cmd_data.cmd_num = -1;
1148 }
1149 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1150 recv_afs_result(vsst, &s->rfds);
1151 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1152 PARA_NOTICE_LOG("requesting new fd from afs\n");
1153 ret = write_buffer(vsst->afs_socket, "new");
1154 if (ret < 0)
1155 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1156 else
1157 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1158 }
1159 for (i = 0; senders[i].name; i++) {
1160 if (!senders[i].post_select)
1161 continue;
1162 senders[i].post_select(&s->rfds, &s->wfds);
1163 }
1164 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1165 (vss_next() && vss_playing()))
1166 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1167 vss_send(vsst);
1168 return 0;
1169 }
1170
1171 /**
1172 * Initialize the virtual streaming system task.
1173 *
1174 * \param afs_socket The fd for communication with afs.
1175 * \param s The scheduler to register the vss task to.
1176 *
1177 * This also initializes all supported senders and starts streaming
1178 * if the --autoplay command line flag was given.
1179 */
1180 void vss_init(int afs_socket, struct sched *s)
1181 {
1182 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1183 int i;
1184 long unsigned announce_time = OPT_UINT32_VAL(ANNOUNCE_TIME),
1185 autoplay_delay = OPT_UINT32_VAL(AUTOPLAY_DELAY);
1186 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1187 vsst->afs_socket = afs_socket;
1188 ms2tv(announce_time, &vsst->announce_tv);
1189 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1190 INIT_LIST_HEAD(&fec_client_list);
1191 for (i = 0; senders[i].name; i++) {
1192 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1193 senders[i].init(&senders[i]);
1194 }
1195 mmd->sender_cmd_data.cmd_num = -1;
1196 if (OPT_GIVEN(AUTOPLAY)) {
1197 struct timeval tmp;
1198 mmd->vss_status_flags |= VSS_PLAYING;
1199 mmd->new_vss_status_flags |= VSS_PLAYING;
1200 ms2tv(autoplay_delay, &tmp);
1201 tv_add(clock_get_realtime(NULL), &tmp, &vsst->autoplay_barrier);
1202 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1203 &vsst->data_send_barrier);
1204 }
1205 vsst->task = task_register(&(struct task_info) {
1206 .name = "vss task",
1207 .pre_select = vss_pre_select,
1208 .post_select = vss_post_select,
1209 .context = vsst,
1210 }, s);
1211 }