Merge branch 'refs/heads/t/xz'
[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
23 #include "para.h"
24 #include "error.h"
25 #include "portable_io.h"
26 #include "fec.h"
27 #include "string.h"
28 #include "afh.h"
29 #include "afs.h"
30 #include "server.h"
31 #include "net.h"
32 #include "server.cmdline.h"
33 #include "list.h"
34 #include "send.h"
35 #include "sched.h"
36 #include "vss.h"
37 #include "ipc.h"
38 #include "fd.h"
39
40 extern struct misc_meta_data *mmd;
41
42 extern void dccp_send_init(struct sender *);
43 extern void http_send_init(struct sender *);
44 extern void udp_send_init(struct sender *);
45
46 /** The list of supported senders. */
47 struct sender senders[] = {
48 {
49 .name = "http",
50 .init = http_send_init,
51 },
52 {
53 .name = "dccp",
54 .init = dccp_send_init,
55 },
56 {
57 .name = "udp",
58 .init = udp_send_init,
59 },
60 {
61 .name = NULL,
62 }
63 };
64
65 /** The possible states of the afs socket. */
66 enum afs_socket_status {
67 /** Socket is inactive. */
68 AFS_SOCKET_READY,
69 /** Socket fd was included in the write fd set for select(). */
70 AFS_SOCKET_CHECK_FOR_WRITE,
71 /** vss wrote a request to the socket and waits for reply from afs. */
72 AFS_SOCKET_AFD_PENDING
73 };
74
75 /** The task structure for the virtual streaming system. */
76 struct vss_task {
77 /** Copied from the -announce_time command line option. */
78 struct timeval announce_tv;
79 /** End of the announcing interval. */
80 struct timeval data_send_barrier;
81 /** End of the EOF interval. */
82 struct timeval eof_barrier;
83 /** Only used if --autoplay_delay was given. */
84 struct timeval autoplay_barrier;
85 /** Used for afs-server communication. */
86 int afs_socket;
87 /** The current state of \a afs_socket. */
88 enum afs_socket_status afsss;
89 /** The memory mapped audio file. */
90 char *map;
91 /** The size of the memory mapping. */
92 size_t mapsize;
93 /** Used by the scheduler. */
94 struct task *task;
95 /** Pointer to the header of the mapped audio file. */
96 char *header_buf;
97 /** Length of the audio file header. */
98 size_t header_len;
99 /** Time between audio file headers are sent. */
100 struct timeval header_interval;
101 /* Only used if afh supports dynamic chunks. */
102 void *afh_context;
103 };
104
105 /**
106 * The list of currently connected fec clients.
107 *
108 * Senders may use \ref vss_add_fec_client() to add entries to the list.
109 */
110 static struct list_head fec_client_list;
111
112 /**
113 * Data associated with one FEC group.
114 *
115 * A FEC group consists of a fixed number of slices and this number is given by
116 * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
117 * group contains a number of chunks of the current audio file.
118 *
119 * FEC slices directly correspond to the data packages sent by the paraslash
120 * senders that use FEC. Each slice is identified by its group number and its
121 * number within the group. All slices have the same size, but the last slice
122 * of the group may not be filled entirely.
123 */
124 struct fec_group {
125 /** The number of the FEC group. */
126 uint32_t num;
127 /** Number of bytes in this group. */
128 uint32_t bytes;
129 /** The first chunk of the current audio file belonging to the group. */
130 uint32_t first_chunk;
131 /** The number of chunks contained in this group. */
132 uint32_t num_chunks;
133 /** When the first chunk was sent. */
134 struct timeval start;
135 /** The duration of the full group. */
136 struct timeval duration;
137 /** The group duration divided by the number of slices. */
138 struct timeval slice_duration;
139 /** Group contains the audio file header that occupies that many slices. */
140 uint8_t num_header_slices;
141 /** Number of bytes per slice for this group. */
142 uint16_t slice_bytes;
143 };
144
145 /** A FEC client is always in one of these states. */
146 enum fec_client_state {
147 FEC_STATE_NONE = 0, /**< not initialized and not enabled */
148 FEC_STATE_DISABLED, /**< temporarily disabled */
149 FEC_STATE_READY_TO_RUN /**< initialized and enabled */
150 };
151
152 /**
153 * Describes one connected FEC client.
154 */
155 struct fec_client {
156 /** Current state of the client */
157 enum fec_client_state state;
158 /** The connected sender client (transport layer). */
159 struct sender_client *sc;
160 /** Parameters requested by the client. */
161 struct fec_client_parms *fcp;
162 /** Used by the core FEC code. */
163 struct fec_parms *parms;
164 /** The position of this client in the fec client list. */
165 struct list_head node;
166 /** When the first slice for this client was sent. */
167 struct timeval stream_start;
168 /** The first chunk sent to this FEC client. */
169 int first_stream_chunk;
170 /** Describes the current group. */
171 struct fec_group group;
172 /** The current slice. */
173 uint8_t current_slice_num;
174 /** The data to be FEC-encoded (point to a region within the mapped audio file). */
175 const unsigned char **src_data;
176 /** Last time an audio header was sent. */
177 struct timeval next_header_time;
178 /** Used for the last source pointer of an audio file. */
179 unsigned char *extra_src_buf;
180 /** Needed for the last slice of the audio file header. */
181 unsigned char *extra_header_buf;
182 /** Extra slices needed to store largest chunk + header. */
183 int num_extra_slices;
184 /** Contains the FEC-encoded data. */
185 unsigned char *enc_buf;
186 /** Maximal packet size. */
187 int mps;
188 };
189
190 /**
191 * Get the chunk time of the current audio file.
192 *
193 * \return A pointer to a struct containing the chunk time, or NULL,
194 * if currently no audio file is selected.
195 */
196 struct timeval *vss_chunk_time(void)
197 {
198 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
199 mmd->afd.afhi.chunk_tv.tv_usec == 0)
200 return NULL;
201 return &mmd->afd.afhi.chunk_tv;
202 }
203
204 /**
205 * Write a fec header to a buffer.
206 *
207 * \param buf The buffer to write to.
208 * \param h The fec header to write.
209 */
210 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
211 {
212 char *buf = (char *)fc->enc_buf;
213 struct fec_group *g = &fc->group;
214 struct fec_client_parms *p = fc->fcp;
215
216 write_u32(buf, FEC_MAGIC);
217
218 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
219 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
220 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
221
222 write_u32(buf + 10, g->num);
223 write_u32(buf + 14, g->bytes);
224
225 write_u8(buf + 18, fc->current_slice_num);
226 write_u8(buf + 19, 0); /* unused */
227 write_u16(buf + 20, g->slice_bytes);
228 write_u8(buf + 22, g->first_chunk? 0 : 1);
229 write_u8(buf + 23, vsst->header_len? 1 : 0);
230 memset(buf + 24, 0, 8);
231 }
232
233 static bool need_audio_header(struct fec_client *fc, struct vss_task *vsst)
234 {
235 if (!mmd->current_chunk) {
236 tv_add(now, &vsst->header_interval, &fc->next_header_time);
237 return false;
238 }
239 if (!vsst->header_buf)
240 return false;
241 if (vsst->header_len == 0)
242 return false;
243 if (fc->group.num > 0) {
244 if (!fc->fcp->need_periodic_header)
245 return false;
246 if (tv_diff(&fc->next_header_time, now, NULL) > 0)
247 return false;
248 }
249 tv_add(now, &vsst->header_interval, &fc->next_header_time);
250 return true;
251 }
252
253 static bool need_data_slices(struct fec_client *fc, struct vss_task *vsst)
254 {
255 if (fc->group.num > 0)
256 return true;
257 if (!vsst->header_buf)
258 return true;
259 if (vsst->header_len == 0)
260 return true;
261 if (fc->fcp->need_periodic_header)
262 return true;
263 return false;
264 }
265
266 static int num_slices(long unsigned bytes, int max_payload, int rs)
267 {
268 int ret;
269
270 assert(max_payload > 0);
271 assert(rs > 0);
272 ret = DIV_ROUND_UP(bytes, max_payload);
273 if (ret + rs > 255)
274 return -E_BAD_CT;
275 return ret;
276 }
277
278 /* set group start and group duration */
279 static void set_group_timing(struct fec_client *fc, struct vss_task *vsst)
280 {
281 struct fec_group *g = &fc->group;
282 struct timeval *chunk_tv = vss_chunk_time();
283
284 if (!need_data_slices(fc, vsst))
285 ms2tv(200, &g->duration);
286 else
287 tv_scale(g->num_chunks, chunk_tv, &g->duration);
288 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
289 &g->duration, &g->slice_duration);
290 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
291 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
292 }
293
294 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
295 {
296 int k, n, ret;
297 int hs, ds, rs; /* header/data/redundant slices */
298 struct fec_client_parms *fcp = fc->fcp;
299
300 /* set mps */
301 if (fcp->init_fec) {
302 /*
303 * Set the maximum slice size to the Maximum Packet Size if the
304 * transport protocol allows to determine this value. The user
305 * can specify a slice size up to this value.
306 */
307 ret = fcp->init_fec(fc->sc);
308 if (ret < 0)
309 return ret;
310 fc->mps = ret;
311 } else
312 fc->mps = generic_max_transport_msg_size(fc->sc->fd);
313 if (fc->mps <= FEC_HEADER_SIZE)
314 return -ERRNO_TO_PARA_ERROR(EINVAL);
315
316 rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
317 ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
318 if (ret < 0)
319 return ret;
320 hs = ret;
321 ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
322 if (ret < 0)
323 return ret;
324 ds = ret;
325 if (fc->fcp->need_periodic_header)
326 k = hs + ds;
327 else
328 k = PARA_MAX(hs, ds);
329 if (k < fc->fcp->data_slices_per_group)
330 k = fc->fcp->data_slices_per_group;
331 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
332 n = k + rs;
333 fec_free(fc->parms);
334 ret = fec_new(k, n, &fc->parms);
335 if (ret < 0)
336 return ret;
337 PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
338 fc->mps, k, n, fc->num_extra_slices);
339 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
340 fc->enc_buf = para_realloc(fc->enc_buf, fc->mps);
341 fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->mps);
342 fc->extra_header_buf = para_realloc(fc->extra_header_buf, fc->mps);
343
344 fc->state = FEC_STATE_READY_TO_RUN;
345 fc->next_header_time.tv_sec = 0;
346 fc->stream_start = *now;
347 fc->first_stream_chunk = mmd->current_chunk;
348 return 1;
349 }
350
351 static void vss_get_chunk(int chunk_num, struct vss_task *vsst,
352 char **buf, size_t *sz)
353 {
354 int ret;
355
356 /*
357 * Chunk zero is special for header streams: It is the first portion of
358 * the audio file which consists of the audio file header. It may be
359 * arbitrary large due to embedded meta data. Audio format handlers may
360 * replace the header by a stripped one with meta data omitted which is
361 * of bounded size. We always use the stripped header for streaming
362 * rather than the unmodified header (chunk zero).
363 */
364 if (chunk_num == 0 && vsst->header_len > 0) {
365 *buf = vsst->header_buf; /* stripped header */
366 *sz = vsst->header_len;
367 return;
368 }
369 ret = afh_get_chunk(chunk_num, &mmd->afd.afhi,
370 mmd->afd.audio_format_id, vsst->map, vsst->mapsize,
371 (const char **)buf, sz, &vsst->afh_context);
372 if (ret < 0) {
373 PARA_WARNING_LOG("could not get chunk %d: %s\n",
374 chunk_num, para_strerror(-ret));
375 *buf = NULL;
376 *sz = 0;
377 }
378 }
379
380 static void compute_group_size(struct vss_task *vsst, struct fec_group *g,
381 int max_bytes)
382 {
383 char *buf;
384 size_t len;
385 int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
386
387 if (g->first_chunk == 0) {
388 g->num_chunks = 1;
389 vss_get_chunk(0, vsst, &buf, &len);
390 g->bytes = len;
391 return;
392 }
393
394 g->num_chunks = 0;
395 g->bytes = 0;
396 /*
397 * Include chunks into the group until the group duration is at least
398 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
399 * super frame) is already larger than 150ms, so a FEC group consists
400 * of exactly one chunk for these audio formats.
401 */
402 for (i = 0;; i++) {
403 int chunk_num = g->first_chunk + i;
404
405 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
406 break;
407 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
408 break;
409 vss_get_chunk(chunk_num, vsst, &buf, &len);
410 if (g->bytes + len > max_bytes)
411 break;
412 /* Include this chunk */
413 g->bytes += len;
414 g->num_chunks++;
415 }
416 assert(g->num_chunks);
417 }
418
419 /*
420 * Compute the slice size of the next group.
421 *
422 * The FEC parameters n and k are fixed but the slice size varies per
423 * FEC group. We'd like to choose slices as small as possible to avoid
424 * unnecessary FEC calculations but large enough to guarantee that the
425 * k data slices suffice to encode the header (if needed) and the data
426 * chunk(s).
427 *
428 * Once we know the payload of the next group, we define the number s
429 * of bytes per slice for this group by
430 *
431 * s = ceil(payload / k)
432 *
433 * However, for header streams, computing s is more complicated since no
434 * overlapping of header and data slices is possible. Hence we have k >=
435 * 2 and s must satisfy
436 *
437 * (*) ceil(h / s) + ceil(d / s) <= k
438 *
439 * where h and d are payload of the header and the data chunk(s)
440 * respectively. In general there is no value for s such that (*)
441 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
442 *
443 * We use the following approach for computing a suitable value for s:
444 *
445 * Let
446 * k1 := ceil(k * min(h, d) / (h + d)),
447 * k2 := k - k1.
448 *
449 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
450 *
451 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
452 *
453 * is well-defined. Inequality (*) holds for this value of s since k1
454 * slices suffice to store min(h, d) while k2 slices suffice to store
455 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
456 * second by k2.
457 *
458 * For the above example we obtain
459 *
460 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
461 * s = max(4000 / 5, 5000 / 5) = 1000,
462 *
463 * which is optimal since a slice size of 999 bytes would already require
464 * 11 slices.
465 */
466 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
467 {
468 struct fec_group *g = &fc->group;
469 int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
470 int n = fc->fcp->slices_per_group + fc->num_extra_slices;
471 int ret, k1, k2, h, d, min, max, sum;
472 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
473 int max_group_bytes;
474
475 if (!need_audio_header(fc, vsst)) {
476 max_group_bytes = k * max_slice_bytes;
477 g->num_header_slices = 0;
478 compute_group_size(vsst, g, max_group_bytes);
479 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
480 if (g->slice_bytes == 0)
481 g->slice_bytes = 1;
482 return 1;
483 }
484 if (!need_data_slices(fc, vsst)) {
485 g->bytes = 0;
486 g->num_chunks = 0;
487 g->slice_bytes = DIV_ROUND_UP(vsst->header_len, k);
488 g->num_header_slices = k;
489 return 1;
490 }
491 h = vsst->header_len;
492 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
493 * max_slice_bytes;
494 compute_group_size(vsst, g, max_group_bytes);
495 d = g->bytes;
496 if (d == 0) {
497 g->slice_bytes = DIV_ROUND_UP(h, k);
498 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
499 if (ret < 0)
500 return ret;
501 g->num_header_slices = ret;
502 return 1;
503 }
504 min = PARA_MIN(h, d);
505 max = PARA_MAX(h, d);
506 sum = h + d;
507 k1 = DIV_ROUND_UP(k * min, sum);
508 k2 = k - k1;
509 assert(k1 > 0);
510 assert(k2 > 0);
511
512 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
513 /*
514 * This value of s := g->slice_bytes satisfies inequality (*) above,
515 * but it might be larger than max_slice_bytes. However, we know that
516 * max_slice_bytes are sufficient to store header and data, so:
517 */
518 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
519
520 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
521 if (ret < 0)
522 return ret;
523 g->num_header_slices = ret;
524 return 1;
525 }
526
527 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
528 {
529 int ret, i, k, n, data_slices;
530 size_t len;
531 char *buf, *p;
532 struct fec_group *g = &fc->group;
533
534 if (fc->state == FEC_STATE_NONE) {
535 ret = initialize_fec_client(fc, vsst);
536 if (ret < 0)
537 return ret;
538 g->first_chunk = mmd->current_chunk;
539 g->num = 0;
540 g->start = *now;
541 } else {
542 struct timeval tmp;
543 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
544 return 0;
545 /*
546 * Start and duration of this group depend only on the previous
547 * group. Compute the new group start as g->start += g->duration.
548 */
549 tmp = g->start;
550 tv_add(&tmp, &g->duration, &g->start);
551 set_group_timing(fc, vsst);
552 g->first_chunk += g->num_chunks;
553 g->num++;
554 }
555 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
556 n = fc->fcp->slices_per_group + fc->num_extra_slices;
557
558 compute_slice_size(fc, vsst);
559 assert(g->slice_bytes > 0);
560 ret = num_slices(g->bytes, g->slice_bytes, n - k);
561 if (ret < 0)
562 return ret;
563 data_slices = ret;
564 assert(g->num_header_slices + data_slices <= k);
565 fc->current_slice_num = 0;
566 if (g->num == 0)
567 set_group_timing(fc, vsst);
568 /* setup header slices */
569 buf = vsst->header_buf;
570 for (i = 0; i < g->num_header_slices; i++) {
571 uint32_t payload_size;
572 if (buf + g->slice_bytes <= vsst->header_buf + vsst->header_len) {
573 fc->src_data[i] = (const unsigned char *)buf;
574 buf += g->slice_bytes;
575 continue;
576 }
577 /*
578 * Can not use vss->header_buf for this slice as it
579 * goes beyond the buffer. This slice will not be fully
580 * used.
581 */
582 payload_size = vsst->header_buf + vsst->header_len - buf;
583 memcpy(fc->extra_header_buf, buf, payload_size);
584 if (payload_size < g->slice_bytes)
585 memset(fc->extra_header_buf + payload_size, 0,
586 g->slice_bytes - payload_size);
587 /*
588 * There might be more than one header slice to fill although
589 * only the first one will be used. Set all header slices to
590 * our extra buffer.
591 */
592 while (i < g->num_header_slices)
593 fc->src_data[i++] = fc->extra_header_buf;
594 break; /* we don't want i to be increased. */
595 }
596
597 /*
598 * Setup data slices. Note that for ogg streams chunk 0 points to a
599 * buffer on the heap rather than to the mapped audio file.
600 */
601 vss_get_chunk(g->first_chunk, vsst, &buf, &len);
602 for (p = buf; i < g->num_header_slices + data_slices; i++) {
603 if (p + g->slice_bytes > buf + g->bytes) {
604 /*
605 * We must make a copy for this slice since using p
606 * directly would exceed the buffer.
607 */
608 uint32_t payload_size = buf + g->bytes - p;
609 assert(payload_size + FEC_HEADER_SIZE <= fc->mps);
610 memcpy(fc->extra_src_buf, p, payload_size);
611 if (payload_size < g->slice_bytes)
612 memset(fc->extra_src_buf + payload_size, 0,
613 g->slice_bytes - payload_size);
614 fc->src_data[i] = fc->extra_src_buf;
615 i++;
616 break;
617 }
618 fc->src_data[i] = (const unsigned char *)p;
619 p += g->slice_bytes;
620 }
621 if (i < k) {
622 /* use arbitrary data for all remaining slices */
623 buf = vsst->map;
624 for (; i < k; i++)
625 fc->src_data[i] = (const unsigned char *)buf;
626 }
627 PARA_DEBUG_LOG("FEC group %u: %u chunks (%u - %u), %u bytes\n",
628 g->num, g->num_chunks, g->first_chunk,
629 g->first_chunk + g->num_chunks - 1, g->bytes
630 );
631 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
632 g->slice_bytes, g->num_header_slices, data_slices
633 );
634 return 1;
635 }
636
637 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
638 {
639 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
640 == fc->fcp->slices_per_group + fc->num_extra_slices) {
641 int ret = setup_next_fec_group(fc, vsst);
642 if (ret == 0)
643 return 0;
644 if (ret < 0) {
645 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
646 PARA_ERROR_LOG("FEC client temporarily disabled\n");
647 fc->state = FEC_STATE_DISABLED;
648 return ret;
649 }
650 }
651 write_fec_header(fc, vsst);
652 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
653 fc->current_slice_num, fc->group.slice_bytes);
654 return 1;
655 }
656
657 /**
658 * Return a buffer that marks the end of the stream.
659 *
660 * \param buf Result pointer.
661 * \return The length of the eof buffer.
662 *
663 * This is used for (multicast) udp streaming where closing the socket on the
664 * sender might not give rise to an eof condition at the peer.
665 */
666 size_t vss_get_fec_eof_packet(const char **buf)
667 {
668 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
669 *buf = fec_eof_packet;
670 return FEC_HEADER_SIZE;
671 }
672
673 /**
674 * Add one entry to the list of active fec clients.
675 *
676 * \param sc Generic sender_client data of the transport layer.
677 * \param fcp FEC parameters as supplied by the transport layer.
678 *
679 * \return Newly allocated fec_client struct.
680 */
681 struct fec_client *vss_add_fec_client(struct sender_client *sc,
682 struct fec_client_parms *fcp)
683 {
684 struct fec_client *fc = para_calloc(sizeof(*fc));
685
686 fc->sc = sc;
687 fc->fcp = fcp;
688 para_list_add(&fc->node, &fec_client_list);
689 return fc;
690 }
691
692 /**
693 * Remove one entry from the list of active fec clients.
694 *
695 * \param fc The client to be removed.
696 */
697 void vss_del_fec_client(struct fec_client *fc)
698 {
699 list_del(&fc->node);
700 free(fc->src_data);
701 free(fc->enc_buf);
702 free(fc->extra_src_buf);
703 free(fc->extra_header_buf);
704 fec_free(fc->parms);
705 free(fc);
706 }
707
708 /*
709 * Compute if/when next slice is due. If it isn't due yet and \a diff is
710 * not \p Null, compute the time difference next - now, where
711 *
712 * next = stream_start + (first_group_chunk - first_stream_chunk)
713 * * chunk_time + slice_num * slice_time
714 */
715 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
716 {
717 struct timeval tmp, next;
718 int ret;
719
720 if (fc->state == FEC_STATE_NONE)
721 return 1;
722 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
723 tv_add(&tmp, &fc->group.start, &next);
724 ret = tv_diff(&next, now, diff);
725 return ret < 0? 1 : 0;
726 }
727
728 static void set_eof_barrier(struct vss_task *vsst)
729 {
730 struct fec_client *fc;
731 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
732
733 if (!chunk_tv)
734 goto out;
735 list_for_each_entry(fc, &fec_client_list, node) {
736 struct timeval group_duration;
737
738 if (fc->state != FEC_STATE_READY_TO_RUN)
739 continue;
740 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
741 if (tv_diff(&timeout, &group_duration, NULL) < 0)
742 timeout = group_duration;
743 }
744 out:
745 tv_add(now, &timeout, &vsst->eof_barrier);
746 }
747
748 /**
749 * Check if vss status flag \a P (playing) is set.
750 *
751 * \return Greater than zero if playing, zero otherwise.
752 *
753 */
754 unsigned int vss_playing(void)
755 {
756 return mmd->new_vss_status_flags & VSS_PLAYING;
757 }
758
759 /**
760 * Check if the \a N (next) status flag is set.
761 *
762 * \return Greater than zero if set, zero if not.
763 *
764 */
765 unsigned int vss_next(void)
766 {
767 return mmd->new_vss_status_flags & VSS_NEXT;
768 }
769
770 /**
771 * Check if a reposition request is pending.
772 *
773 * \return Greater than zero if true, zero otherwise.
774 *
775 */
776 unsigned int vss_repos(void)
777 {
778 return mmd->new_vss_status_flags & VSS_REPOS;
779 }
780
781 /**
782 * Check if the vss is currently paused.
783 *
784 * \return Greater than zero if paused, zero otherwise.
785 *
786 */
787 unsigned int vss_paused(void)
788 {
789 return !(mmd->new_vss_status_flags & VSS_NEXT)
790 && !(mmd->new_vss_status_flags & VSS_PLAYING);
791 }
792
793 /**
794 * Check if the vss is currently stopped.
795 *
796 * \return Greater than zero if paused, zero otherwise.
797 *
798 */
799 unsigned int vss_stopped(void)
800 {
801 return (mmd->new_vss_status_flags & VSS_NEXT)
802 && !(mmd->new_vss_status_flags & VSS_PLAYING);
803 }
804
805 static int chk_barrier(const char *bname, const struct timeval *barrier,
806 struct timeval *diff, int print_log)
807 {
808 long ms;
809
810 if (tv_diff(now, barrier, diff) > 0)
811 return 1;
812 ms = tv2ms(diff);
813 if (print_log && ms)
814 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
815 return -1;
816 }
817
818 static void vss_compute_timeout(struct sched *s, struct vss_task *vsst)
819 {
820 struct timeval tv;
821 struct fec_client *fc;
822
823 if (!vss_playing() || !vsst->map)
824 return;
825 if (vss_next() && vsst->map) /* only sleep a bit, nec*/
826 return sched_request_timeout_ms(100, s);
827
828 /* Each of these barriers must have passed until we may proceed */
829 if (sched_request_barrier(&vsst->autoplay_barrier, s) == 1)
830 return;
831 if (sched_request_barrier(&vsst->eof_barrier, s) == 1)
832 return;
833 if (sched_request_barrier(&vsst->data_send_barrier, s) == 1)
834 return;
835 /*
836 * Compute the select timeout as the minimal time until the next
837 * chunk/slice is due for any client.
838 */
839 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
840 &mmd->stream_start, &tv);
841 if (sched_request_barrier_or_min_delay(&tv, s) == 0)
842 return;
843 list_for_each_entry(fc, &fec_client_list, node) {
844 if (fc->state != FEC_STATE_READY_TO_RUN)
845 continue;
846 if (next_slice_is_due(fc, &tv))
847 return sched_min_delay(s);
848 sched_request_timeout(&tv, s);
849 }
850 }
851
852 static void vss_eof(struct vss_task *vsst)
853 {
854
855 if (!vsst->map)
856 return;
857 if (mmd->new_vss_status_flags & VSS_NOMORE)
858 mmd->new_vss_status_flags = VSS_NEXT;
859 set_eof_barrier(vsst);
860 afh_free_header(vsst->header_buf, mmd->afd.audio_format_id);
861 vsst->header_buf = NULL;
862 para_munmap(vsst->map, vsst->mapsize);
863 vsst->map = NULL;
864 mmd->chunks_sent = 0;
865 //mmd->offset = 0;
866 mmd->afd.afhi.seconds_total = 0;
867 mmd->afd.afhi.chunk_tv.tv_sec = 0;
868 mmd->afd.afhi.chunk_tv.tv_usec = 0;
869 free(mmd->afd.afhi.chunk_table);
870 mmd->afd.afhi.chunk_table = NULL;
871 vsst->mapsize = 0;
872 afh_close(vsst->afh_context, mmd->afd.audio_format_id);
873 vsst->afh_context = NULL;
874 mmd->events++;
875 }
876
877 static int need_to_request_new_audio_file(struct vss_task *vsst)
878 {
879 struct timeval diff;
880
881 if (vsst->map) /* have audio file */
882 return 0;
883 if (!vss_playing()) /* don't need one */
884 return 0;
885 if (mmd->new_vss_status_flags & VSS_NOMORE)
886 return 0;
887 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
888 return 0;
889 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
890 &diff, 1) < 0)
891 return 0;
892 return 1;
893 }
894
895 static void set_mmd_offset(void)
896 {
897 struct timeval offset;
898 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
899 mmd->offset = tv2ms(&offset);
900 }
901
902 static void vss_pre_select(struct sched *s, void *context)
903 {
904 int i;
905 struct vss_task *vsst = context;
906
907 if (need_to_request_new_audio_file(vsst)) {
908 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
909 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
910 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
911 } else
912 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
913 for (i = 0; senders[i].name; i++) {
914 if (!senders[i].pre_select)
915 continue;
916 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
917 }
918 vss_compute_timeout(s, vsst);
919 }
920
921 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
922 {
923 char control[255] __a_aligned(8), buf[8];
924 struct msghdr msg = {.msg_iov = NULL};
925 struct cmsghdr *cmsg;
926 struct iovec iov;
927 int ret = 0;
928
929 *fd = -1;
930 iov.iov_base = buf;
931 iov.iov_len = sizeof(buf);
932 msg.msg_iov = &iov;
933 msg.msg_iovlen = 1;
934 msg.msg_control = control;
935 msg.msg_controllen = sizeof(control);
936 memset(buf, 0, sizeof(buf));
937 ret = recvmsg(afs_socket, &msg, 0);
938 if (ret < 0)
939 return -ERRNO_TO_PARA_ERROR(errno);
940 if (iov.iov_len != sizeof(buf))
941 return -E_AFS_SHORT_READ;
942 *code = *(uint32_t*)buf;
943 *data = *(uint32_t*)(buf + 4);
944 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
945 if (cmsg->cmsg_level != SOL_SOCKET
946 || cmsg->cmsg_type != SCM_RIGHTS)
947 continue;
948 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
949 continue;
950 *fd = *(int *)CMSG_DATA(cmsg);
951 }
952 return 1;
953 }
954
955 #ifndef MAP_POPULATE
956 #define MAP_POPULATE 0
957 #endif
958
959 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
960 {
961 int ret, passed_fd, shmid;
962 uint32_t afs_code = 0, afs_data = 0;
963 struct stat statbuf;
964
965 if (!FD_ISSET(vsst->afs_socket, rfds))
966 return;
967 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
968 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
969 return;
970 if (ret < 0)
971 goto err;
972 vsst->afsss = AFS_SOCKET_READY;
973 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
974 afs_data);
975 ret = -E_NOFD;
976 if (afs_code != NEXT_AUDIO_FILE)
977 goto err;
978 if (passed_fd < 0)
979 goto err;
980 shmid = afs_data;
981 ret = load_afd(shmid, &mmd->afd);
982 if (ret < 0)
983 goto err;
984 shm_destroy(shmid);
985 ret = fstat(passed_fd, &statbuf);
986 if (ret < 0) {
987 PARA_ERROR_LOG("fstat error:\n");
988 ret = -ERRNO_TO_PARA_ERROR(errno);
989 goto err;
990 }
991 ret = para_mmap(statbuf.st_size, PROT_READ, MAP_PRIVATE | MAP_POPULATE,
992 passed_fd, 0, &vsst->map);
993 if (ret < 0)
994 goto err;
995 vsst->mapsize = statbuf.st_size;
996 close(passed_fd);
997 mmd->chunks_sent = 0;
998 mmd->current_chunk = 0;
999 mmd->offset = 0;
1000 mmd->events++;
1001 mmd->num_played++;
1002 mmd->new_vss_status_flags &= (~VSS_NEXT);
1003 afh_get_header(&mmd->afd.afhi, mmd->afd.audio_format_id,
1004 vsst->map, vsst->mapsize, &vsst->header_buf, &vsst->header_len);
1005 return;
1006 err:
1007 free(mmd->afd.afhi.chunk_table);
1008 if (passed_fd >= 0)
1009 close(passed_fd);
1010 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1011 mmd->new_vss_status_flags = VSS_NEXT;
1012 }
1013
1014 /**
1015 * Main sending function.
1016 *
1017 * This function gets called from vss_post_select(). It checks whether the next
1018 * chunk of data should be pushed out. It obtains a pointer to the data to be
1019 * sent out as well as its length from mmd->afd.afhi. This information is then
1020 * passed to each supported sender's send() function as well as to the send()
1021 * functions of each registered fec client.
1022 */
1023 static void vss_send(struct vss_task *vsst)
1024 {
1025 int i, fec_active = 0;
1026 struct timeval due;
1027 struct fec_client *fc, *tmp_fc;
1028
1029 if (!vsst->map || !vss_playing())
1030 return;
1031 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
1032 return;
1033 if (chk_barrier("data send", &vsst->data_send_barrier,
1034 &due, 1) < 0)
1035 return;
1036 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
1037 if (fc->state == FEC_STATE_DISABLED)
1038 continue;
1039 if (!next_slice_is_due(fc, NULL)) {
1040 fec_active = 1;
1041 continue;
1042 }
1043 if (compute_next_fec_slice(fc, vsst) <= 0)
1044 continue;
1045 PARA_DEBUG_LOG("sending %u:%u (%u bytes)\n", fc->group.num,
1046 fc->current_slice_num, fc->group.slice_bytes);
1047 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1048 fc->group.slice_bytes + FEC_HEADER_SIZE);
1049 fc->current_slice_num++;
1050 fec_active = 1;
1051 }
1052 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1053 if (!fec_active)
1054 mmd->new_vss_status_flags |= VSS_NEXT;
1055 return;
1056 }
1057 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1058 &mmd->stream_start, &due);
1059 if (tv_diff(&due, now, NULL) <= 0) {
1060 char *buf;
1061 size_t len;
1062
1063 if (!mmd->chunks_sent) {
1064 mmd->stream_start = *now;
1065 mmd->events++;
1066 set_mmd_offset();
1067 }
1068 /*
1069 * We call the send function also in case of empty chunks as
1070 * they might have still some data queued which can be sent in
1071 * this case.
1072 */
1073 vss_get_chunk(mmd->current_chunk, vsst, &buf, &len);
1074 for (i = 0; senders[i].name; i++) {
1075 if (!senders[i].send)
1076 continue;
1077 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1078 buf, len, vsst->header_buf, vsst->header_len);
1079 }
1080 /*
1081 * Prefault next chunk(s)
1082 *
1083 * If the backing device of the memory-mapped audio file is
1084 * slow and read-ahead is turned off or prevented for some
1085 * reason, e.g. due to memory pressure, it may take much longer
1086 * than the chunk interval to get the next chunk on the wire,
1087 * causing buffer underruns on the client side. Mapping the
1088 * file with MAP_POPULATE seems to help a bit, but it does not
1089 * eliminate the delays completely. Moreover, it is supported
1090 * only on Linux. So we do our own read-ahead here.
1091 */
1092 if (mmd->current_chunk > 0) { /* chunk 0 might be on the heap */
1093 buf += len;
1094 for (i = 0; i < 5 && buf < vsst->map + vsst->mapsize; i++) {
1095 __a_unused volatile char x = *buf;
1096 buf += 4096;
1097 }
1098 }
1099 mmd->chunks_sent++;
1100 mmd->current_chunk++;
1101 }
1102 }
1103
1104 static int vss_post_select(struct sched *s, void *context)
1105 {
1106 int ret, i;
1107 struct vss_task *vsst = context;
1108
1109 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
1110 /* shut down senders and fec clients */
1111 struct fec_client *fc, *tmp;
1112 for (i = 0; senders[i].name; i++)
1113 if (senders[i].shutdown_clients)
1114 senders[i].shutdown_clients();
1115 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
1116 fc->state = FEC_STATE_NONE;
1117 mmd->stream_start.tv_sec = 0;
1118 mmd->stream_start.tv_usec = 0;
1119 }
1120 if (vss_next())
1121 vss_eof(vsst);
1122 else if (vss_paused()) {
1123 if (mmd->chunks_sent)
1124 set_eof_barrier(vsst);
1125 mmd->chunks_sent = 0;
1126 } else if (vss_repos()) { /* repositioning due to ff/jmp command */
1127 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1128 set_eof_barrier(vsst);
1129 mmd->chunks_sent = 0;
1130 mmd->current_chunk = afh_get_start_chunk(mmd->repos_request,
1131 &mmd->afd.afhi, mmd->afd.audio_format_id);
1132 mmd->new_vss_status_flags &= ~VSS_REPOS;
1133 set_mmd_offset();
1134 }
1135 /* If a sender command is pending, run it. */
1136 if (mmd->sender_cmd_data.cmd_num >= 0) {
1137 int num = mmd->sender_cmd_data.cmd_num,
1138 sender_num = mmd->sender_cmd_data.sender_num;
1139
1140 if (senders[sender_num].client_cmds[num]) {
1141 ret = senders[sender_num].client_cmds[num]
1142 (&mmd->sender_cmd_data);
1143 if (ret < 0)
1144 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1145 }
1146 mmd->sender_cmd_data.cmd_num = -1;
1147 }
1148 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1149 recv_afs_result(vsst, &s->rfds);
1150 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1151 PARA_NOTICE_LOG("requesting new fd from afs\n");
1152 ret = write_buffer(vsst->afs_socket, "new");
1153 if (ret < 0)
1154 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1155 else
1156 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1157 }
1158 for (i = 0; senders[i].name; i++) {
1159 if (!senders[i].post_select)
1160 continue;
1161 senders[i].post_select(&s->rfds, &s->wfds);
1162 }
1163 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1164 (vss_next() && vss_playing()))
1165 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1166 vss_send(vsst);
1167 return 0;
1168 }
1169
1170 /**
1171 * Initialize the virtual streaming system task.
1172 *
1173 * \param afs_socket The fd for communication with afs.
1174 * \param s The scheduler to register the vss task to.
1175 *
1176 * This also initializes all supported senders and starts streaming
1177 * if the --autoplay command line flag was given.
1178 */
1179 void init_vss_task(int afs_socket, struct sched *s)
1180 {
1181 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1182 int i;
1183 char *hn = para_hostname(), *home = para_homedir();
1184 long unsigned announce_time = conf.announce_time_arg > 0?
1185 conf.announce_time_arg : 300,
1186 autoplay_delay = conf.autoplay_delay_arg > 0?
1187 conf.autoplay_delay_arg : 0;
1188 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1189 vsst->afs_socket = afs_socket;
1190 ms2tv(announce_time, &vsst->announce_tv);
1191 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1192 INIT_LIST_HEAD(&fec_client_list);
1193 for (i = 0; senders[i].name; i++) {
1194 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1195 senders[i].init(&senders[i]);
1196 }
1197 free(hn);
1198 free(home);
1199 mmd->sender_cmd_data.cmd_num = -1;
1200 if (conf.autoplay_given) {
1201 struct timeval tmp;
1202 mmd->vss_status_flags |= VSS_PLAYING;
1203 mmd->new_vss_status_flags |= VSS_PLAYING;
1204 ms2tv(autoplay_delay, &tmp);
1205 tv_add(clock_get_realtime(NULL), &tmp, &vsst->autoplay_barrier);
1206 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1207 &vsst->data_send_barrier);
1208 }
1209 vsst->task = task_register(&(struct task_info) {
1210 .name = "vss task",
1211 .pre_select = vss_pre_select,
1212 .post_select = vss_post_select,
1213 .context = vsst,
1214 }, s);
1215 }