Avoid member access within misaligned address for ancillary data buffer.
[paraslash.git] / vss.c
1 /*
2 * Copyright (C) 1997-2013 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 <osl.h>
16
17 #include "para.h"
18 #include "error.h"
19 #include "portable_io.h"
20 #include "fec.h"
21 #include "string.h"
22 #include "afh.h"
23 #include "afs.h"
24 #include "server.h"
25 #include "net.h"
26 #include "server.cmdline.h"
27 #include "list.h"
28 #include "send.h"
29 #include "sched.h"
30 #include "vss.h"
31 #include "ipc.h"
32 #include "fd.h"
33
34 extern struct misc_meta_data *mmd;
35
36 extern void dccp_send_init(struct sender *);
37 extern void http_send_init(struct sender *);
38 extern void udp_send_init(struct sender *);
39
40 /** The list of supported senders. */
41 struct sender senders[] = {
42 {
43 .name = "http",
44 .init = http_send_init,
45 },
46 {
47 .name = "dccp",
48 .init = dccp_send_init,
49 },
50 {
51 .name = "udp",
52 .init = udp_send_init,
53 },
54 {
55 .name = NULL,
56 }
57 };
58
59 /** The possible states of the afs socket. */
60 enum afs_socket_status {
61 /** Socket is inactive. */
62 AFS_SOCKET_READY,
63 /** Socket fd was included in the write fd set for select(). */
64 AFS_SOCKET_CHECK_FOR_WRITE,
65 /** vss wrote a request to the socket and waits for reply from afs. */
66 AFS_SOCKET_AFD_PENDING
67 };
68
69 /** The task structure for the virtual streaming system. */
70 struct vss_task {
71 /** Copied from the -announce_time command line option. */
72 struct timeval announce_tv;
73 /** End of the announcing interval. */
74 struct timeval data_send_barrier;
75 /** End of the EOF interval. */
76 struct timeval eof_barrier;
77 /** Only used if --autoplay_delay was given. */
78 struct timeval autoplay_barrier;
79 /** Used for afs-server communication. */
80 int afs_socket;
81 /** The current state of \a afs_socket. */
82 enum afs_socket_status afsss;
83 /** The memory mapped audio file. */
84 char *map;
85 /** Used by the scheduler. */
86 struct task task;
87 /** Pointer to the header of the mapped audio file. */
88 char *header_buf;
89 /** Length of the audio file header. */
90 size_t header_len;
91 /** Time between audio file headers are sent. */
92 struct timeval header_interval;
93 };
94
95 /**
96 * The list of currently connected fec clients.
97 *
98 * Senders may use \ref vss_add_fec_client() to add entries to the list.
99 */
100 static struct list_head fec_client_list;
101
102 /**
103 * Data associated with one FEC group.
104 *
105 * A FEC group consists of a fixed number of slices and this number is given by
106 * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
107 * group contains a number of chunks of the current audio file.
108 *
109 * FEC slices directly correspond to the data packages sent by the paraslash
110 * senders that use FEC. Each slice is identified by its group number and its
111 * number within the group. All slices have the same size, but the last slice
112 * of the group may not be filled entirely.
113 */
114 struct fec_group {
115 /** The number of the FEC group. */
116 uint32_t num;
117 /** Number of bytes in this group. */
118 uint32_t bytes;
119 /** The first chunk of the current audio file belonging to the group. */
120 uint32_t first_chunk;
121 /** The number of chunks contained in this group. */
122 uint32_t num_chunks;
123 /** When the first chunk was sent. */
124 struct timeval start;
125 /** The duration of the full group. */
126 struct timeval duration;
127 /** The group duration divided by the number of slices. */
128 struct timeval slice_duration;
129 /** Group contains the audio file header that occupies that many slices. */
130 uint8_t num_header_slices;
131 /** Number of bytes per slice for this group. */
132 uint16_t slice_bytes;
133 };
134
135 /** A FEC client is always in one of these states. */
136 enum fec_client_state {
137 FEC_STATE_NONE = 0, /**< not initialized and not enabled */
138 FEC_STATE_DISABLED, /**< temporarily disabled */
139 FEC_STATE_READY_TO_RUN /**< initialized and enabled */
140 };
141
142 /**
143 * Describes one connected FEC client.
144 */
145 struct fec_client {
146 /** Current state of the client */
147 enum fec_client_state state;
148 /** The connected sender client (transport layer). */
149 struct sender_client *sc;
150 /** Parameters requested by the client. */
151 struct fec_client_parms *fcp;
152 /** Used by the core FEC code. */
153 struct fec_parms *parms;
154 /** The position of this client in the fec client list. */
155 struct list_head node;
156 /** When the first slice for this client was sent. */
157 struct timeval stream_start;
158 /** The first chunk sent to this FEC client. */
159 int first_stream_chunk;
160 /** Describes the current group. */
161 struct fec_group group;
162 /** The current slice. */
163 uint8_t current_slice_num;
164 /** The data to be FEC-encoded (point to a region within the mapped audio file). */
165 const unsigned char **src_data;
166 /** Last time an audio header was sent. */
167 struct timeval next_header_time;
168 /** Used for the last source pointer of an audio file. */
169 unsigned char *extra_src_buf;
170 /** Needed for the last slice of the audio file header. */
171 unsigned char *extra_header_buf;
172 /** Extra slices needed to store largest chunk + header. */
173 int num_extra_slices;
174 /** Contains the FEC-encoded data. */
175 unsigned char *enc_buf;
176 /** Maximal packet size. */
177 int mps;
178 };
179
180 /**
181 * Get the chunk time of the current audio file.
182 *
183 * \return A pointer to a struct containing the chunk time, or NULL,
184 * if currently no audio file is selected.
185 */
186 struct timeval *vss_chunk_time(void)
187 {
188 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
189 mmd->afd.afhi.chunk_tv.tv_usec == 0)
190 return NULL;
191 return &mmd->afd.afhi.chunk_tv;
192 }
193
194 /**
195 * Write a fec header to a buffer.
196 *
197 * \param buf The buffer to write to.
198 * \param h The fec header to write.
199 */
200 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
201 {
202 char *buf = (char *)fc->enc_buf;
203 struct fec_group *g = &fc->group;
204 struct fec_client_parms *p = fc->fcp;
205
206 write_u32(buf, FEC_MAGIC);
207
208 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
209 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
210 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
211
212 write_u32(buf + 10, g->num);
213 write_u32(buf + 14, g->bytes);
214
215 write_u8(buf + 18, fc->current_slice_num);
216 write_u8(buf + 19, 0); /* unused */
217 write_u16(buf + 20, g->slice_bytes);
218 write_u8(buf + 22, g->first_chunk? 0 : 1);
219 write_u8(buf + 23, vsst->header_len? 1 : 0);
220 memset(buf + 24, 0, 8);
221 }
222
223 static bool need_audio_header(struct fec_client *fc, struct vss_task *vsst)
224 {
225 if (!mmd->current_chunk) {
226 tv_add(now, &vsst->header_interval, &fc->next_header_time);
227 return false;
228 }
229 if (!vsst->header_buf)
230 return false;
231 if (vsst->header_len == 0)
232 return false;
233 if (fc->group.num > 0) {
234 if (!fc->fcp->need_periodic_header)
235 return false;
236 if (tv_diff(&fc->next_header_time, now, NULL) > 0)
237 return false;
238 }
239 tv_add(now, &vsst->header_interval, &fc->next_header_time);
240 return true;
241 }
242
243 static bool need_data_slices(struct fec_client *fc, struct vss_task *vsst)
244 {
245 if (fc->group.num > 0)
246 return true;
247 if (!vsst->header_buf)
248 return true;
249 if (vsst->header_len == 0)
250 return true;
251 if (fc->fcp->need_periodic_header)
252 return true;
253 return false;
254 }
255
256 static int num_slices(long unsigned bytes, int max_payload, int rs)
257 {
258 int ret;
259
260 assert(max_payload > 0);
261 assert(rs > 0);
262 ret = DIV_ROUND_UP(bytes, max_payload);
263 if (ret + rs > 255)
264 return -E_BAD_CT;
265 return ret;
266 }
267
268 /* set group start and group duration */
269 static void set_group_timing(struct fec_client *fc, struct vss_task *vsst)
270 {
271 struct fec_group *g = &fc->group;
272 struct timeval *chunk_tv = vss_chunk_time();
273
274 if (!need_data_slices(fc, vsst))
275 ms2tv(200, &g->duration);
276 else
277 tv_scale(g->num_chunks, chunk_tv, &g->duration);
278 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
279 &g->duration, &g->slice_duration);
280 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
281 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
282 }
283
284 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
285 {
286 int k, n, ret;
287 int hs, ds, rs; /* header/data/redundant slices */
288 struct fec_client_parms *fcp = fc->fcp;
289
290 /* set mps */
291 if (fcp->init_fec) {
292 /*
293 * Set the maximum slice size to the Maximum Packet Size if the
294 * transport protocol allows to determine this value. The user
295 * can specify a slice size up to this value.
296 */
297 ret = fcp->init_fec(fc->sc);
298 if (ret < 0)
299 return ret;
300 fc->mps = ret;
301 } else
302 fc->mps = generic_max_transport_msg_size(fc->sc->fd);
303 if (fc->mps <= FEC_HEADER_SIZE)
304 return -ERRNO_TO_PARA_ERROR(EINVAL);
305
306 rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
307 ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
308 if (ret < 0)
309 return ret;
310 hs = ret;
311 ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
312 if (ret < 0)
313 return ret;
314 ds = ret;
315 if (fc->fcp->need_periodic_header)
316 k = hs + ds;
317 else
318 k = PARA_MAX(hs, ds);
319 if (k < fc->fcp->data_slices_per_group)
320 k = fc->fcp->data_slices_per_group;
321 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
322 n = k + rs;
323 fec_free(fc->parms);
324 ret = fec_new(k, n, &fc->parms);
325 if (ret < 0)
326 return ret;
327 PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
328 fc->mps, k, n, fc->num_extra_slices);
329 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
330 fc->enc_buf = para_realloc(fc->enc_buf, fc->mps);
331 fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->mps);
332 fc->extra_header_buf = para_realloc(fc->extra_header_buf, fc->mps);
333
334 fc->state = FEC_STATE_READY_TO_RUN;
335 fc->next_header_time.tv_sec = 0;
336 fc->stream_start = *now;
337 fc->first_stream_chunk = mmd->current_chunk;
338 return 1;
339 }
340
341 static void vss_get_chunk(int chunk_num, struct vss_task *vsst,
342 char **buf, size_t *sz)
343 {
344 /*
345 * Chunk zero is special for header streams: It is the first portion of
346 * the audio file which consists of the audio file header. It may be
347 * arbitrary large due to embedded meta data. Audio format handlers may
348 * replace the header by a stripped one with meta data omitted which is
349 * of bounded size. We always use the stripped header for streaming
350 * rather than the unmodified header (chunk zero).
351 */
352 if (chunk_num == 0 && vsst->header_len > 0) {
353 *buf = vsst->header_buf; /* stripped header */
354 *sz = vsst->header_len;
355 return;
356 }
357 afh_get_chunk(chunk_num, &mmd->afd.afhi, vsst->map, (const char **)buf,
358 sz);
359 }
360
361 static void compute_group_size(struct vss_task *vsst, struct fec_group *g,
362 int max_bytes)
363 {
364 char *buf;
365 size_t len;
366 int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
367
368 if (g->first_chunk == 0) {
369 g->num_chunks = 1;
370 vss_get_chunk(0, vsst, &buf, &len);
371 g->bytes = len;
372 return;
373 }
374
375 g->num_chunks = 0;
376 g->bytes = 0;
377 /*
378 * Include chunks into the group until the group duration is at least
379 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
380 * super frame) is already larger than 150ms, so a FEC group consists
381 * of exactly one chunk for these audio formats.
382 */
383 for (i = 0;; i++) {
384 int chunk_num = g->first_chunk + i;
385
386 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
387 break;
388 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
389 break;
390 vss_get_chunk(chunk_num, vsst, &buf, &len);
391 if (g->bytes + len > max_bytes)
392 break;
393 /* Include this chunk */
394 g->bytes += len;
395 g->num_chunks++;
396 }
397 assert(g->num_chunks);
398 }
399
400 /*
401 * Compute the slice size of the next group.
402 *
403 * The FEC parameters n and k are fixed but the slice size varies per
404 * FEC group. We'd like to choose slices as small as possible to avoid
405 * unnecessary FEC calculations but large enough to guarantee that the
406 * k data slices suffice to encode the header (if needed) and the data
407 * chunk(s).
408 *
409 * Once we know the payload of the next group, we define the number s
410 * of bytes per slice for this group by
411 *
412 * s = ceil(payload / k)
413 *
414 * However, for header streams, computing s is more complicated since no
415 * overlapping of header and data slices is possible. Hence we have k >=
416 * 2 and s must satisfy
417 *
418 * (*) ceil(h / s) + ceil(d / s) <= k
419 *
420 * where h and d are payload of the header and the data chunk(s)
421 * respectively. In general there is no value for s such that (*)
422 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
423 *
424 * We use the following approach for computing a suitable value for s:
425 *
426 * Let
427 * k1 := ceil(k * min(h, d) / (h + d)),
428 * k2 := k - k1.
429 *
430 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
431 *
432 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
433 *
434 * is well-defined. Inequality (*) holds for this value of s since k1
435 * slices suffice to store min(h, d) while k2 slices suffice to store
436 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
437 * second by k2.
438 *
439 * For the above example we obtain
440 *
441 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
442 * s = max(4000 / 5, 5000 / 5) = 1000,
443 *
444 * which is optimal since a slice size of 999 bytes would already require
445 * 11 slices.
446 */
447 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
448 {
449 struct fec_group *g = &fc->group;
450 int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
451 int n = fc->fcp->slices_per_group + fc->num_extra_slices;
452 int ret, k1, k2, h, d, min, max, sum;
453 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
454 int max_group_bytes;
455
456 if (!need_audio_header(fc, vsst)) {
457 max_group_bytes = k * max_slice_bytes;
458 g->num_header_slices = 0;
459 compute_group_size(vsst, g, max_group_bytes);
460 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
461 if (g->slice_bytes == 0)
462 g->slice_bytes = 1;
463 return 1;
464 }
465 if (!need_data_slices(fc, vsst)) {
466 g->bytes = 0;
467 g->num_chunks = 0;
468 g->slice_bytes = DIV_ROUND_UP(vsst->header_len, k);
469 g->num_header_slices = k;
470 return 1;
471 }
472 h = vsst->header_len;
473 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
474 * max_slice_bytes;
475 compute_group_size(vsst, g, max_group_bytes);
476 d = g->bytes;
477 if (d == 0) {
478 g->slice_bytes = DIV_ROUND_UP(h, k);
479 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
480 if (ret < 0)
481 return ret;
482 g->num_header_slices = ret;
483 return 1;
484 }
485 min = PARA_MIN(h, d);
486 max = PARA_MAX(h, d);
487 sum = h + d;
488 k1 = DIV_ROUND_UP(k * min, sum);
489 k2 = k - k1;
490 assert(k1 > 0);
491 assert(k2 > 0);
492
493 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
494 /*
495 * This value of s := g->slice_bytes satisfies inequality (*) above,
496 * but it might be larger than max_slice_bytes. However, we know that
497 * max_slice_bytes are sufficient to store header and data, so:
498 */
499 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
500
501 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
502 if (ret < 0)
503 return ret;
504 g->num_header_slices = ret;
505 return 1;
506 }
507
508 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
509 {
510 int ret, i, k, n, data_slices;
511 size_t len;
512 char *buf, *p;
513 struct fec_group *g = &fc->group;
514
515 if (fc->state == FEC_STATE_NONE) {
516 ret = initialize_fec_client(fc, vsst);
517 if (ret < 0)
518 return ret;
519 g->first_chunk = mmd->current_chunk;
520 g->num = 0;
521 g->start = *now;
522 } else {
523 struct timeval tmp;
524 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
525 return 0;
526 /*
527 * Start and duration of this group depend only on the previous
528 * group. Compute the new group start as g->start += g->duration.
529 */
530 tmp = g->start;
531 tv_add(&tmp, &g->duration, &g->start);
532 set_group_timing(fc, vsst);
533 g->first_chunk += g->num_chunks;
534 g->num++;
535 }
536 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
537 n = fc->fcp->slices_per_group + fc->num_extra_slices;
538
539 compute_slice_size(fc, vsst);
540 assert(g->slice_bytes > 0);
541 ret = num_slices(g->bytes, g->slice_bytes, n - k);
542 if (ret < 0)
543 return ret;
544 data_slices = ret;
545 assert(g->num_header_slices + data_slices <= k);
546 fc->current_slice_num = 0;
547 if (g->num == 0)
548 set_group_timing(fc, vsst);
549 /* setup header slices */
550 buf = vsst->header_buf;
551 for (i = 0; i < g->num_header_slices; i++) {
552 uint32_t payload_size;
553 if (buf + g->slice_bytes <= vsst->header_buf + vsst->header_len) {
554 fc->src_data[i] = (const unsigned char *)buf;
555 buf += g->slice_bytes;
556 continue;
557 }
558 /*
559 * Can not use vss->header_buf for this slice as it
560 * goes beyond the buffer. This slice will not be fully
561 * used.
562 */
563 payload_size = vsst->header_buf + vsst->header_len - buf;
564 memcpy(fc->extra_header_buf, buf, payload_size);
565 if (payload_size < g->slice_bytes)
566 memset(fc->extra_header_buf + payload_size, 0,
567 g->slice_bytes - payload_size);
568 /*
569 * There might be more than one header slice to fill although
570 * only the first one will be used. Set all header slices to
571 * our extra buffer.
572 */
573 while (i < g->num_header_slices)
574 fc->src_data[i++] = fc->extra_header_buf;
575 break; /* we don't want i to be increased. */
576 }
577
578 /*
579 * Setup data slices. Note that for ogg streams chunk 0 points to a
580 * buffer on the heap rather than to the mapped audio file.
581 */
582 vss_get_chunk(g->first_chunk, vsst, &buf, &len);
583 for (p = buf; i < g->num_header_slices + data_slices; i++) {
584 if (p + g->slice_bytes > buf + g->bytes) {
585 /*
586 * We must make a copy for this slice since using p
587 * directly would exceed the buffer.
588 */
589 uint32_t payload_size = buf + g->bytes - p;
590 assert(payload_size + FEC_HEADER_SIZE <= fc->mps);
591 memcpy(fc->extra_src_buf, p, payload_size);
592 if (payload_size < g->slice_bytes)
593 memset(fc->extra_src_buf + payload_size, 0,
594 g->slice_bytes - payload_size);
595 fc->src_data[i] = fc->extra_src_buf;
596 i++;
597 break;
598 }
599 fc->src_data[i] = (const unsigned char *)p;
600 p += g->slice_bytes;
601 }
602 if (i < k) {
603 /* use arbitrary data for all remaining slices */
604 buf = vsst->map;
605 for (; i < k; i++)
606 fc->src_data[i] = (const unsigned char *)buf;
607 }
608 PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), %d bytes\n",
609 g->num, g->num_chunks, g->first_chunk,
610 g->first_chunk + g->num_chunks - 1, g->bytes
611 );
612 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
613 g->slice_bytes, g->num_header_slices, data_slices
614 );
615 return 1;
616 }
617
618 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
619 {
620 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
621 == fc->fcp->slices_per_group + fc->num_extra_slices) {
622 int ret = setup_next_fec_group(fc, vsst);
623 if (ret == 0)
624 return 0;
625 if (ret < 0) {
626 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
627 PARA_ERROR_LOG("FEC client temporarily disabled\n");
628 fc->state = FEC_STATE_DISABLED;
629 return ret;
630 }
631 }
632 write_fec_header(fc, vsst);
633 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
634 fc->current_slice_num, fc->group.slice_bytes);
635 return 1;
636 }
637
638 /**
639 * Return a buffer that marks the end of the stream.
640 *
641 * \param buf Result pointer.
642 * \return The length of the eof buffer.
643 *
644 * This is used for (multicast) udp streaming where closing the socket on the
645 * sender might not give rise to an eof condition at the peer.
646 */
647 size_t vss_get_fec_eof_packet(const char **buf)
648 {
649 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
650 *buf = fec_eof_packet;
651 return FEC_HEADER_SIZE;
652 }
653
654 /**
655 * Add one entry to the list of active fec clients.
656 *
657 * \param sc Generic sender_client data of the transport layer.
658 * \param fcp FEC parameters as supplied by the transport layer.
659 *
660 * \return Newly allocated fec_client struct.
661 */
662 struct fec_client *vss_add_fec_client(struct sender_client *sc,
663 struct fec_client_parms *fcp)
664 {
665 struct fec_client *fc = para_calloc(sizeof(*fc));
666
667 fc->sc = sc;
668 fc->fcp = fcp;
669 para_list_add(&fc->node, &fec_client_list);
670 return fc;
671 }
672
673 /**
674 * Remove one entry from the list of active fec clients.
675 *
676 * \param fc The client to be removed.
677 */
678 void vss_del_fec_client(struct fec_client *fc)
679 {
680 list_del(&fc->node);
681 free(fc->src_data);
682 free(fc->enc_buf);
683 free(fc->extra_src_buf);
684 free(fc->extra_header_buf);
685 fec_free(fc->parms);
686 free(fc);
687 }
688
689 /*
690 * Compute if/when next slice is due. If it isn't due yet and \a diff is
691 * not \p Null, compute the time difference next - now, where
692 *
693 * next = stream_start + (first_group_chunk - first_stream_chunk)
694 * * chunk_time + slice_num * slice_time
695 */
696 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
697 {
698 struct timeval tmp, next;
699 int ret;
700
701 if (fc->state == FEC_STATE_NONE)
702 return 1;
703 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
704 tv_add(&tmp, &fc->group.start, &next);
705 ret = tv_diff(&next, now, diff);
706 return ret < 0? 1 : 0;
707 }
708
709 static void set_eof_barrier(struct vss_task *vsst)
710 {
711 struct fec_client *fc;
712 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
713
714 if (!chunk_tv)
715 goto out;
716 list_for_each_entry(fc, &fec_client_list, node) {
717 struct timeval group_duration;
718
719 if (fc->state != FEC_STATE_READY_TO_RUN)
720 continue;
721 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
722 if (tv_diff(&timeout, &group_duration, NULL) < 0)
723 timeout = group_duration;
724 }
725 out:
726 tv_add(now, &timeout, &vsst->eof_barrier);
727 }
728
729 /**
730 * Check if vss status flag \a P (playing) is set.
731 *
732 * \return Greater than zero if playing, zero otherwise.
733 *
734 */
735 unsigned int vss_playing(void)
736 {
737 return mmd->new_vss_status_flags & VSS_PLAYING;
738 }
739
740 /**
741 * Check if the \a N (next) status flag is set.
742 *
743 * \return Greater than zero if set, zero if not.
744 *
745 */
746 unsigned int vss_next(void)
747 {
748 return mmd->new_vss_status_flags & VSS_NEXT;
749 }
750
751 /**
752 * Check if a reposition request is pending.
753 *
754 * \return Greater than zero if true, zero otherwise.
755 *
756 */
757 unsigned int vss_repos(void)
758 {
759 return mmd->new_vss_status_flags & VSS_REPOS;
760 }
761
762 /**
763 * Check if the vss is currently paused.
764 *
765 * \return Greater than zero if paused, zero otherwise.
766 *
767 */
768 unsigned int vss_paused(void)
769 {
770 return !(mmd->new_vss_status_flags & VSS_NEXT)
771 && !(mmd->new_vss_status_flags & VSS_PLAYING);
772 }
773
774 /**
775 * Check if the vss is currently stopped.
776 *
777 * \return Greater than zero if paused, zero otherwise.
778 *
779 */
780 unsigned int vss_stopped(void)
781 {
782 return (mmd->new_vss_status_flags & VSS_NEXT)
783 && !(mmd->new_vss_status_flags & VSS_PLAYING);
784 }
785
786 static int chk_barrier(const char *bname, const struct timeval *barrier,
787 struct timeval *diff, int print_log)
788 {
789 long ms;
790
791 if (tv_diff(now, barrier, diff) > 0)
792 return 1;
793 ms = tv2ms(diff);
794 if (print_log && ms)
795 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
796 return -1;
797 }
798
799 static void vss_compute_timeout(struct sched *s, struct vss_task *vsst)
800 {
801 struct timeval tv;
802 struct fec_client *fc;
803
804 if (!vss_playing() || !vsst->map)
805 return;
806 if (vss_next() && vsst->map) /* only sleep a bit, nec*/
807 return sched_request_timeout_ms(100, s);
808
809 /* Each of these barriers must have passed until we may proceed */
810 if (sched_request_barrier(&vsst->autoplay_barrier, s) == 1)
811 return;
812 if (sched_request_barrier(&vsst->eof_barrier, s) == 1)
813 return;
814 if (sched_request_barrier(&vsst->data_send_barrier, s) == 1)
815 return;
816 /*
817 * Compute the select timeout as the minimal time until the next
818 * chunk/slice is due for any client.
819 */
820 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
821 &mmd->stream_start, &tv);
822 if (sched_request_barrier_or_min_delay(&tv, s) == 0)
823 return;
824 list_for_each_entry(fc, &fec_client_list, node) {
825 if (fc->state != FEC_STATE_READY_TO_RUN)
826 continue;
827 if (next_slice_is_due(fc, &tv))
828 return sched_min_delay(s);
829 sched_request_timeout(&tv, s);
830 }
831 }
832
833 static void vss_eof(struct vss_task *vsst)
834 {
835
836 if (!vsst->map)
837 return;
838 if (mmd->new_vss_status_flags & VSS_NOMORE)
839 mmd->new_vss_status_flags = VSS_NEXT;
840 set_eof_barrier(vsst);
841 afh_free_header(vsst->header_buf, mmd->afd.audio_format_id);
842 vsst->header_buf = NULL;
843 para_munmap(vsst->map, mmd->size);
844 vsst->map = NULL;
845 mmd->chunks_sent = 0;
846 //mmd->offset = 0;
847 mmd->afd.afhi.seconds_total = 0;
848 mmd->afd.afhi.chunk_tv.tv_sec = 0;
849 mmd->afd.afhi.chunk_tv.tv_usec = 0;
850 free(mmd->afd.afhi.chunk_table);
851 mmd->afd.afhi.chunk_table = NULL;
852 mmd->mtime = 0;
853 mmd->size = 0;
854 mmd->events++;
855 }
856
857 static int need_to_request_new_audio_file(struct vss_task *vsst)
858 {
859 struct timeval diff;
860
861 if (vsst->map) /* have audio file */
862 return 0;
863 if (!vss_playing()) /* don't need one */
864 return 0;
865 if (mmd->new_vss_status_flags & VSS_NOMORE)
866 return 0;
867 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
868 return 0;
869 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
870 &diff, 1) < 0)
871 return 0;
872 return 1;
873 }
874
875 static void set_mmd_offset(void)
876 {
877 struct timeval offset;
878 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
879 mmd->offset = tv2ms(&offset);
880 }
881
882 /**
883 * Compute the timeout for the main select-loop of the scheduler.
884 *
885 * \param s Pointer to the server scheduler.
886 * \param t Pointer to the vss task structure.
887 *
888 * Before the timeout is computed, the current vss status flags are evaluated
889 * and acted upon by calling appropriate functions from the lower layers.
890 * Possible actions include
891 *
892 * - request a new audio file from afs,
893 * - shutdown of all senders (stop/pause command),
894 * - reposition the stream (ff/jmp command).
895 */
896 static void vss_pre_select(struct sched *s, struct task *t)
897 {
898 int i;
899 struct vss_task *vsst = container_of(t, struct vss_task, task);
900
901 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
902 struct fec_client *fc, *tmp;
903 for (i = 0; senders[i].name; i++)
904 if (senders[i].shutdown_clients)
905 senders[i].shutdown_clients();
906 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
907 fc->state = FEC_STATE_NONE;
908 mmd->stream_start.tv_sec = 0;
909 mmd->stream_start.tv_usec = 0;
910 }
911 if (vss_next())
912 vss_eof(vsst);
913 else if (vss_paused()) {
914 if (mmd->chunks_sent)
915 set_eof_barrier(vsst);
916 mmd->chunks_sent = 0;
917 } else if (vss_repos()) {
918 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
919 set_eof_barrier(vsst);
920 mmd->chunks_sent = 0;
921 mmd->current_chunk = mmd->repos_request;
922 mmd->new_vss_status_flags &= ~VSS_REPOS;
923 set_mmd_offset();
924 }
925 if (need_to_request_new_audio_file(vsst)) {
926 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
927 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
928 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
929 } else
930 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
931 for (i = 0; senders[i].name; i++) {
932 if (!senders[i].pre_select)
933 continue;
934 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
935 }
936 vss_compute_timeout(s, vsst);
937 }
938
939 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
940 {
941 char control[255] __a_aligned(8), buf[8];
942 struct msghdr msg = {.msg_iov = NULL};
943 struct cmsghdr *cmsg;
944 struct iovec iov;
945 int ret = 0;
946
947 *fd = -1;
948 iov.iov_base = buf;
949 iov.iov_len = sizeof(buf);
950 msg.msg_iov = &iov;
951 msg.msg_iovlen = 1;
952 msg.msg_control = control;
953 msg.msg_controllen = sizeof(control);
954 memset(buf, 0, sizeof(buf));
955 ret = recvmsg(afs_socket, &msg, 0);
956 if (ret < 0)
957 return -ERRNO_TO_PARA_ERROR(errno);
958 if (iov.iov_len != sizeof(buf))
959 return -E_AFS_SHORT_READ;
960 *code = *(uint32_t*)buf;
961 *data = *(uint32_t*)(buf + 4);
962 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
963 if (cmsg->cmsg_level != SOL_SOCKET
964 || cmsg->cmsg_type != SCM_RIGHTS)
965 continue;
966 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
967 continue;
968 *fd = *(int *)CMSG_DATA(cmsg);
969 }
970 return 1;
971 }
972
973 #ifndef MAP_POPULATE
974 #define MAP_POPULATE 0
975 #endif
976
977 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
978 {
979 int ret, passed_fd, shmid;
980 uint32_t afs_code = 0, afs_data = 0;
981 struct stat statbuf;
982
983 if (!FD_ISSET(vsst->afs_socket, rfds))
984 return;
985 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
986 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
987 return;
988 if (ret < 0)
989 goto err;
990 vsst->afsss = AFS_SOCKET_READY;
991 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
992 afs_data);
993 ret = -E_NOFD;
994 if (afs_code != NEXT_AUDIO_FILE)
995 goto err;
996 if (passed_fd < 0)
997 goto err;
998 shmid = afs_data;
999 ret = load_afd(shmid, &mmd->afd);
1000 if (ret < 0)
1001 goto err;
1002 shm_destroy(shmid);
1003 ret = fstat(passed_fd, &statbuf);
1004 if (ret < 0) {
1005 PARA_ERROR_LOG("fstat error:\n");
1006 ret = -ERRNO_TO_PARA_ERROR(errno);
1007 goto err;
1008 }
1009 mmd->size = statbuf.st_size;
1010 mmd->mtime = statbuf.st_mtime;
1011 ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE | MAP_POPULATE,
1012 passed_fd, 0, &vsst->map);
1013 if (ret < 0)
1014 goto err;
1015 close(passed_fd);
1016 mmd->chunks_sent = 0;
1017 mmd->current_chunk = 0;
1018 mmd->offset = 0;
1019 mmd->events++;
1020 mmd->num_played++;
1021 mmd->new_vss_status_flags &= (~VSS_NEXT);
1022 afh_get_header(&mmd->afd.afhi, mmd->afd.audio_format_id,
1023 vsst->map, mmd->size, &vsst->header_buf, &vsst->header_len);
1024 return;
1025 err:
1026 free(mmd->afd.afhi.chunk_table);
1027 if (passed_fd >= 0)
1028 close(passed_fd);
1029 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1030 mmd->new_vss_status_flags = VSS_NEXT;
1031 }
1032
1033 /**
1034 * Main sending function.
1035 *
1036 * This function gets called from vss_post_select(). It checks whether the next
1037 * chunk of data should be pushed out. It obtains a pointer to the data to be
1038 * sent out as well as its length from mmd->afd.afhi. This information is then
1039 * passed to each supported sender's send() function as well as to the send()
1040 * functions of each registered fec client.
1041 */
1042 static void vss_send(struct vss_task *vsst)
1043 {
1044 int i, fec_active = 0;
1045 struct timeval due;
1046 struct fec_client *fc, *tmp_fc;
1047
1048 if (!vsst->map || !vss_playing())
1049 return;
1050 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
1051 return;
1052 if (chk_barrier("data send", &vsst->data_send_barrier,
1053 &due, 1) < 0)
1054 return;
1055 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
1056 if (fc->state == FEC_STATE_DISABLED)
1057 continue;
1058 if (!next_slice_is_due(fc, NULL)) {
1059 fec_active = 1;
1060 continue;
1061 }
1062 if (compute_next_fec_slice(fc, vsst) <= 0)
1063 continue;
1064 PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
1065 fc->current_slice_num, fc->group.slice_bytes);
1066 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1067 fc->group.slice_bytes + FEC_HEADER_SIZE);
1068 fc->current_slice_num++;
1069 fec_active = 1;
1070 }
1071 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1072 if (!fec_active)
1073 mmd->new_vss_status_flags |= VSS_NEXT;
1074 return;
1075 }
1076 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1077 &mmd->stream_start, &due);
1078 if (tv_diff(&due, now, NULL) <= 0) {
1079 char *buf;
1080 size_t len;
1081
1082 if (!mmd->chunks_sent) {
1083 mmd->stream_start = *now;
1084 mmd->events++;
1085 set_mmd_offset();
1086 }
1087 /*
1088 * We call the send function also in case of empty chunks as
1089 * they might have still some data queued which can be sent in
1090 * this case.
1091 */
1092 vss_get_chunk(mmd->current_chunk, vsst, &buf, &len);
1093 for (i = 0; senders[i].name; i++) {
1094 if (!senders[i].send)
1095 continue;
1096 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1097 buf, len, vsst->header_buf, vsst->header_len);
1098 }
1099 /*
1100 * Prefault next chunk(s)
1101 *
1102 * If the backing device of the memory-mapped audio file is
1103 * slow and read-ahead is turned off or prevented for some
1104 * reason, e.g. due to memory pressure, it may take much longer
1105 * than the chunk interval to get the next chunk on the wire,
1106 * causing buffer underruns on the client side. Mapping the
1107 * file with MAP_POPULATE seems to help a bit, but it does not
1108 * eliminate the delays completely. Moreover, it is supported
1109 * only on Linux. So we do our own read-ahead here.
1110 */
1111 if (mmd->current_chunk > 0) { /* chunk 0 might be on the heap */
1112 buf += len;
1113 for (i = 0; i < 5 && buf < vsst->map + mmd->size; i++) {
1114 __a_unused volatile char x = *buf;
1115 buf += 4096;
1116 }
1117 }
1118 mmd->chunks_sent++;
1119 mmd->current_chunk++;
1120 }
1121 }
1122
1123 static int vss_post_select(struct sched *s, struct task *t)
1124 {
1125 int ret, i;
1126 struct vss_task *vsst = container_of(t, struct vss_task, task);
1127
1128 if (mmd->sender_cmd_data.cmd_num >= 0) {
1129 int num = mmd->sender_cmd_data.cmd_num,
1130 sender_num = mmd->sender_cmd_data.sender_num;
1131
1132 if (senders[sender_num].client_cmds[num]) {
1133 ret = senders[sender_num].client_cmds[num]
1134 (&mmd->sender_cmd_data);
1135 if (ret < 0)
1136 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1137 }
1138 mmd->sender_cmd_data.cmd_num = -1;
1139 }
1140 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1141 recv_afs_result(vsst, &s->rfds);
1142 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1143 PARA_NOTICE_LOG("requesting new fd from afs\n");
1144 ret = write_buffer(vsst->afs_socket, "new");
1145 if (ret < 0)
1146 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1147 else
1148 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1149 }
1150 for (i = 0; senders[i].name; i++) {
1151 if (!senders[i].post_select)
1152 continue;
1153 senders[i].post_select(&s->rfds, &s->wfds);
1154 }
1155 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1156 (vss_next() && vss_playing()))
1157 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1158 vss_send(vsst);
1159 return 0;
1160 }
1161
1162 /**
1163 * Initialize the virtual streaming system task.
1164 *
1165 * \param afs_socket The fd for communication with afs.
1166 * \param s The scheduler to register the vss task to.
1167 *
1168 * This also initializes all supported senders and starts streaming
1169 * if the --autoplay command line flag was given.
1170 */
1171 void init_vss_task(int afs_socket, struct sched *s)
1172 {
1173 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1174 int i;
1175 char *hn = para_hostname(), *home = para_homedir();
1176 long unsigned announce_time = conf.announce_time_arg > 0?
1177 conf.announce_time_arg : 300,
1178 autoplay_delay = conf.autoplay_delay_arg > 0?
1179 conf.autoplay_delay_arg : 0;
1180 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1181 vsst->afs_socket = afs_socket;
1182 vsst->task.pre_select = vss_pre_select;
1183 vsst->task.post_select = vss_post_select;
1184 ms2tv(announce_time, &vsst->announce_tv);
1185 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1186 INIT_LIST_HEAD(&fec_client_list);
1187 for (i = 0; senders[i].name; i++) {
1188 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1189 senders[i].init(&senders[i]);
1190 }
1191 free(hn);
1192 free(home);
1193 mmd->sender_cmd_data.cmd_num = -1;
1194 if (conf.autoplay_given) {
1195 struct timeval tmp;
1196 mmd->vss_status_flags |= VSS_PLAYING;
1197 mmd->new_vss_status_flags |= VSS_PLAYING;
1198 ms2tv(autoplay_delay, &tmp);
1199 tv_add(now, &tmp, &vsst->autoplay_barrier);
1200 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1201 &vsst->data_send_barrier);
1202 }
1203 sprintf(vsst->task.status, "vss task");
1204 register_task(s, &vsst->task);
1205 }