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1c3f1e73 | 1 | /* |
2 | * This file is part of DisOrder | |
5aff007d | 3 | * Copyright (C) 2005-2008 Richard Kettlewell |
1c3f1e73 | 4 | * |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
18 | * USA | |
19 | */ | |
20 | /** @file server/speaker-network.c | |
21 | * @brief Support for @ref BACKEND_NETWORK */ | |
22 | ||
05b75f8d | 23 | #include "common.h" |
1c3f1e73 | 24 | |
25 | #include <unistd.h> | |
26 | #include <poll.h> | |
27 | #include <netdb.h> | |
28 | #include <gcrypt.h> | |
29 | #include <sys/socket.h> | |
30 | #include <sys/uio.h> | |
81b1bf12 | 31 | #include <net/if.h> |
db2c19dc | 32 | #include <ifaddrs.h> |
6d2d327c | 33 | #include <errno.h> |
edbd470f | 34 | #include <netinet/in.h> |
1c3f1e73 | 35 | |
36 | #include "configuration.h" | |
37 | #include "syscalls.h" | |
38 | #include "log.h" | |
39 | #include "addr.h" | |
40 | #include "timeval.h" | |
41 | #include "rtp.h" | |
81b1bf12 | 42 | #include "ifreq.h" |
1c3f1e73 | 43 | #include "speaker-protocol.h" |
44 | #include "speaker.h" | |
45 | ||
46 | /** @brief Network socket | |
47 | * | |
48 | * This is the file descriptor to write to for @ref BACKEND_NETWORK. | |
49 | */ | |
50 | static int bfd = -1; | |
51 | ||
52 | /** @brief RTP timestamp | |
53 | * | |
54 | * This counts the number of samples played (NB not the number of frames | |
55 | * played). | |
56 | * | |
57 | * The timestamp in the packet header is only 32 bits wide. With 44100Hz | |
58 | * stereo, that only gives about half a day before wrapping, which is not | |
59 | * particularly convenient for certain debugging purposes. Therefore the | |
60 | * timestamp is maintained as a 64-bit integer, giving around six million years | |
61 | * before wrapping, and truncated to 32 bits when transmitting. | |
62 | */ | |
63 | static uint64_t rtp_time; | |
64 | ||
65 | /** @brief RTP base timestamp | |
66 | * | |
67 | * This is the real time correspoding to an @ref rtp_time of 0. It is used | |
68 | * to recalculate the timestamp after idle periods. | |
69 | */ | |
70 | static struct timeval rtp_time_0; | |
71 | ||
72 | /** @brief RTP packet sequence number */ | |
73 | static uint16_t rtp_seq; | |
74 | ||
75 | /** @brief RTP SSRC */ | |
76 | static uint32_t rtp_id; | |
77 | ||
78 | /** @brief Error counter */ | |
79 | static int audio_errors; | |
80 | ||
81 | /** @brief Network backend initialization */ | |
82 | static void network_init(void) { | |
83 | struct addrinfo *res, *sres; | |
84 | static const struct addrinfo pref = { | |
66613034 RK |
85 | .ai_flags = 0, |
86 | .ai_family = PF_INET, | |
87 | .ai_socktype = SOCK_DGRAM, | |
88 | .ai_protocol = IPPROTO_UDP, | |
1c3f1e73 | 89 | }; |
90 | static const struct addrinfo prefbind = { | |
66613034 RK |
91 | .ai_flags = AI_PASSIVE, |
92 | .ai_family = PF_INET, | |
93 | .ai_socktype = SOCK_DGRAM, | |
94 | .ai_protocol = IPPROTO_UDP, | |
1c3f1e73 | 95 | }; |
96 | static const int one = 1; | |
db2c19dc | 97 | int sndbuf, target_sndbuf = 131072; |
1c3f1e73 | 98 | socklen_t len; |
99 | char *sockname, *ssockname; | |
100 | ||
101 | res = get_address(&config->broadcast, &pref, &sockname); | |
102 | if(!res) exit(-1); | |
103 | if(config->broadcast_from.n) { | |
104 | sres = get_address(&config->broadcast_from, &prefbind, &ssockname); | |
105 | if(!sres) exit(-1); | |
106 | } else | |
107 | sres = 0; | |
108 | if((bfd = socket(res->ai_family, | |
109 | res->ai_socktype, | |
110 | res->ai_protocol)) < 0) | |
111 | fatal(errno, "error creating broadcast socket"); | |
6fba990c | 112 | if(multicast(res->ai_addr)) { |
23205f9c RK |
113 | /* Multicasting */ |
114 | switch(res->ai_family) { | |
115 | case PF_INET: { | |
116 | const int mttl = config->multicast_ttl; | |
117 | if(setsockopt(bfd, IPPROTO_IP, IP_MULTICAST_TTL, &mttl, sizeof mttl) < 0) | |
118 | fatal(errno, "error setting IP_MULTICAST_TTL on multicast socket"); | |
61941295 RK |
119 | if(setsockopt(bfd, IPPROTO_IP, IP_MULTICAST_LOOP, |
120 | &config->multicast_loop, sizeof one) < 0) | |
121 | fatal(errno, "error setting IP_MULTICAST_LOOP on multicast socket"); | |
23205f9c RK |
122 | break; |
123 | } | |
124 | case PF_INET6: { | |
125 | const int mttl = config->multicast_ttl; | |
126 | if(setsockopt(bfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, | |
127 | &mttl, sizeof mttl) < 0) | |
128 | fatal(errno, "error setting IPV6_MULTICAST_HOPS on multicast socket"); | |
61941295 RK |
129 | if(setsockopt(bfd, IPPROTO_IP, IPV6_MULTICAST_LOOP, |
130 | &config->multicast_loop, sizeof (int)) < 0) | |
131 | fatal(errno, "error setting IPV6_MULTICAST_LOOP on multicast socket"); | |
23205f9c RK |
132 | break; |
133 | } | |
134 | default: | |
135 | fatal(0, "unsupported address family %d", res->ai_family); | |
136 | } | |
81b1bf12 | 137 | info("multicasting on %s", sockname); |
23205f9c | 138 | } else { |
db2c19dc | 139 | struct ifaddrs *ifs; |
81b1bf12 | 140 | |
db2c19dc RK |
141 | if(getifaddrs(&ifs) < 0) |
142 | fatal(errno, "error calling getifaddrs"); | |
143 | while(ifs) { | |
3aa6f359 RK |
144 | /* (At least on Darwin) IFF_BROADCAST might be set but ifa_broadaddr |
145 | * still a null pointer. It turns out that there's a subsequent entry | |
146 | * for he same interface which _does_ have ifa_broadaddr though... */ | |
db2c19dc | 147 | if((ifs->ifa_flags & IFF_BROADCAST) |
3aa6f359 | 148 | && ifs->ifa_broadaddr |
db2c19dc | 149 | && sockaddr_equal(ifs->ifa_broadaddr, res->ai_addr)) |
81b1bf12 | 150 | break; |
db2c19dc | 151 | ifs = ifs->ifa_next; |
81b1bf12 | 152 | } |
db2c19dc | 153 | if(ifs) { |
81b1bf12 RK |
154 | if(setsockopt(bfd, SOL_SOCKET, SO_BROADCAST, &one, sizeof one) < 0) |
155 | fatal(errno, "error setting SO_BROADCAST on broadcast socket"); | |
db2c19dc | 156 | info("broadcasting on %s (%s)", sockname, ifs->ifa_name); |
81b1bf12 RK |
157 | } else |
158 | info("unicasting on %s", sockname); | |
23205f9c | 159 | } |
1c3f1e73 | 160 | len = sizeof sndbuf; |
161 | if(getsockopt(bfd, SOL_SOCKET, SO_SNDBUF, | |
162 | &sndbuf, &len) < 0) | |
163 | fatal(errno, "error getting SO_SNDBUF"); | |
164 | if(target_sndbuf > sndbuf) { | |
165 | if(setsockopt(bfd, SOL_SOCKET, SO_SNDBUF, | |
166 | &target_sndbuf, sizeof target_sndbuf) < 0) | |
167 | error(errno, "error setting SO_SNDBUF to %d", target_sndbuf); | |
168 | else | |
169 | info("changed socket send buffer size from %d to %d", | |
170 | sndbuf, target_sndbuf); | |
171 | } else | |
172 | info("default socket send buffer is %d", | |
173 | sndbuf); | |
174 | /* We might well want to set additional broadcast- or multicast-related | |
175 | * options here */ | |
176 | if(sres && bind(bfd, sres->ai_addr, sres->ai_addrlen) < 0) | |
177 | fatal(errno, "error binding broadcast socket to %s", ssockname); | |
178 | if(connect(bfd, res->ai_addr, res->ai_addrlen) < 0) | |
179 | fatal(errno, "error connecting broadcast socket to %s", sockname); | |
180 | /* Select an SSRC */ | |
181 | gcry_randomize(&rtp_id, sizeof rtp_id, GCRY_STRONG_RANDOM); | |
1c3f1e73 | 182 | } |
183 | ||
184 | /** @brief Play over the network */ | |
185 | static size_t network_play(size_t frames) { | |
186 | struct rtp_header header; | |
187 | struct iovec vec[2]; | |
6d2d327c | 188 | size_t bytes = frames * bpf, written_frames; |
1c3f1e73 | 189 | int written_bytes; |
190 | /* We transmit using RTP (RFC3550) and attempt to conform to the internet | |
191 | * AVT profile (RFC3551). */ | |
192 | ||
23741390 RK |
193 | /* If we're starting then initialize the base time */ |
194 | if(!rtp_time) | |
195 | xgettimeofday(&rtp_time_0, 0); | |
1c3f1e73 | 196 | if(idled) { |
197 | /* There may have been a gap. Fix up the RTP time accordingly. */ | |
198 | struct timeval now; | |
199 | uint64_t delta; | |
200 | uint64_t target_rtp_time; | |
201 | ||
202 | /* Find the current time */ | |
203 | xgettimeofday(&now, 0); | |
204 | /* Find the number of microseconds elapsed since rtp_time=0 */ | |
205 | delta = tvsub_us(now, rtp_time_0); | |
23741390 RK |
206 | if(delta > UINT64_MAX / 88200) |
207 | fatal(0, "rtp_time=%llu now=%ld.%06ld rtp_time_0=%ld.%06ld delta=%llu (%lld)", | |
208 | rtp_time, | |
209 | (long)now.tv_sec, (long)now.tv_usec, | |
210 | (long)rtp_time_0.tv_sec, (long)rtp_time_0.tv_usec, | |
211 | delta, delta); | |
6d2d327c RK |
212 | target_rtp_time = (delta * config->sample_format.rate |
213 | * config->sample_format.channels) / 1000000; | |
1c3f1e73 | 214 | /* Overflows at ~6 years uptime with 44100Hz stereo */ |
215 | ||
216 | /* rtp_time is the number of samples we've played. NB that we play | |
217 | * RTP_AHEAD_MS ahead of ourselves, so it may legitimately be ahead of | |
218 | * the value we deduce from time comparison. | |
219 | * | |
220 | * Suppose we have 1s track started at t=0, and another track begins to | |
24d6fd25 RK |
221 | * play at t=2s. Suppose 44100Hz stereo. We send 1s of audio over the |
222 | * next (about) one second, giving rtp_time=88200. rtp_time stops at this | |
223 | * point. | |
1c3f1e73 | 224 | * |
225 | * At t=2s we'll have calculated target_rtp_time=176400. In this case we | |
226 | * set rtp_time=176400 and the player can correctly conclude that it | |
227 | * should leave 1s between the tracks. | |
228 | * | |
24d6fd25 RK |
229 | * It's never right to reduce rtp_time, for that would imply packets with |
230 | * overlapping timestamp ranges, which does not make sense. | |
1c3f1e73 | 231 | */ |
232 | target_rtp_time &= ~(uint64_t)1; /* stereo! */ | |
233 | if(target_rtp_time > rtp_time) { | |
234 | /* More time has elapsed than we've transmitted samples. That implies | |
235 | * we've been 'sending' silence. */ | |
236 | info("advancing rtp_time by %"PRIu64" samples", | |
237 | target_rtp_time - rtp_time); | |
238 | rtp_time = target_rtp_time; | |
239 | } else if(target_rtp_time < rtp_time) { | |
24d6fd25 RK |
240 | info("would reverse rtp_time by %"PRIu64" samples", |
241 | rtp_time - target_rtp_time); | |
1c3f1e73 | 242 | } |
243 | } | |
244 | header.vpxcc = 2 << 6; /* V=2, P=0, X=0, CC=0 */ | |
245 | header.seq = htons(rtp_seq++); | |
246 | header.timestamp = htonl((uint32_t)rtp_time); | |
247 | header.ssrc = rtp_id; | |
248 | header.mpt = (idled ? 0x80 : 0x00) | 10; | |
249 | /* 10 = L16 = 16-bit x 2 x 44100KHz. We ought to deduce this value from | |
250 | * the sample rate (in a library somewhere so that configuration.c can rule | |
251 | * out invalid rates). | |
252 | */ | |
253 | idled = 0; | |
254 | if(bytes > NETWORK_BYTES - sizeof header) { | |
255 | bytes = NETWORK_BYTES - sizeof header; | |
256 | /* Always send a whole number of frames */ | |
6d2d327c | 257 | bytes -= bytes % bpf; |
1c3f1e73 | 258 | } |
259 | /* "The RTP clock rate used for generating the RTP timestamp is independent | |
260 | * of the number of channels and the encoding; it equals the number of | |
261 | * sampling periods per second. For N-channel encodings, each sampling | |
262 | * period (say, 1/8000 of a second) generates N samples. (This terminology | |
263 | * is standard, but somewhat confusing, as the total number of samples | |
264 | * generated per second is then the sampling rate times the channel | |
265 | * count.)" | |
266 | */ | |
267 | vec[0].iov_base = (void *)&header; | |
268 | vec[0].iov_len = sizeof header; | |
269 | vec[1].iov_base = playing->buffer + playing->start; | |
270 | vec[1].iov_len = bytes; | |
271 | do { | |
272 | written_bytes = writev(bfd, vec, 2); | |
273 | } while(written_bytes < 0 && errno == EINTR); | |
274 | if(written_bytes < 0) { | |
275 | error(errno, "error transmitting audio data"); | |
276 | ++audio_errors; | |
277 | if(audio_errors == 10) | |
278 | fatal(0, "too many audio errors"); | |
279 | return 0; | |
280 | } else | |
281 | audio_errors /= 2; | |
282 | written_bytes -= sizeof (struct rtp_header); | |
6d2d327c | 283 | written_frames = written_bytes / bpf; |
1c3f1e73 | 284 | /* Advance RTP's notion of the time */ |
6d2d327c | 285 | rtp_time += written_frames * config->sample_format.channels; |
1c3f1e73 | 286 | return written_frames; |
287 | } | |
288 | ||
289 | static int bfd_slot; | |
290 | ||
291 | /** @brief Set up poll array for network play */ | |
e84fb5f0 | 292 | static void network_beforepoll(int *timeoutp) { |
1c3f1e73 | 293 | struct timeval now; |
294 | uint64_t target_us; | |
295 | uint64_t target_rtp_time; | |
e84fb5f0 RK |
296 | const int64_t samples_per_second = config->sample_format.rate |
297 | * config->sample_format.channels; | |
e84fb5f0 | 298 | int64_t lead, ahead_ms; |
1c3f1e73 | 299 | |
300 | /* If we're starting then initialize the base time */ | |
301 | if(!rtp_time) | |
302 | xgettimeofday(&rtp_time_0, 0); | |
24d6fd25 | 303 | /* We send audio data whenever we would otherwise get behind */ |
1c3f1e73 | 304 | xgettimeofday(&now, 0); |
305 | target_us = tvsub_us(now, rtp_time_0); | |
23741390 RK |
306 | if(target_us > UINT64_MAX / 88200) |
307 | fatal(0, "rtp_time=%llu rtp_time_0=%ld.%06ld now=%ld.%06ld target_us=%llu (%lld)\n", | |
308 | rtp_time, | |
309 | (long)rtp_time_0.tv_sec, (long)rtp_time_0.tv_usec, | |
310 | (long)now.tv_sec, (long)now.tv_usec, | |
311 | target_us, target_us); | |
1c3f1e73 | 312 | target_rtp_time = (target_us * config->sample_format.rate |
313 | * config->sample_format.channels) | |
314 | / 1000000; | |
24d6fd25 | 315 | /* Lead is how far ahead we are */ |
e84fb5f0 | 316 | lead = rtp_time - target_rtp_time; |
24d6fd25 RK |
317 | if(lead <= 0) |
318 | /* We're behind or even, so we'll need to write as soon as we can */ | |
1c3f1e73 | 319 | bfd_slot = addfd(bfd, POLLOUT); |
e84fb5f0 | 320 | else { |
24d6fd25 RK |
321 | /* We've ahead, we can afford to wait a bit even if the IP stack thinks it |
322 | * can accept more. */ | |
323 | ahead_ms = 1000 * lead / samples_per_second; | |
e84fb5f0 RK |
324 | if(ahead_ms < *timeoutp) |
325 | *timeoutp = ahead_ms; | |
326 | } | |
1c3f1e73 | 327 | } |
328 | ||
329 | /** @brief Process poll() results for network play */ | |
330 | static int network_ready(void) { | |
331 | if(fds[bfd_slot].revents & (POLLOUT | POLLERR)) | |
332 | return 1; | |
333 | else | |
334 | return 0; | |
335 | } | |
336 | ||
337 | const struct speaker_backend network_backend = { | |
338 | BACKEND_NETWORK, | |
6d2d327c | 339 | 0, |
1c3f1e73 | 340 | network_init, |
341 | 0, /* activate */ | |
342 | network_play, | |
343 | 0, /* deactivate */ | |
344 | network_beforepoll, | |
345 | network_ready | |
346 | }; | |
347 | ||
348 | /* | |
349 | Local Variables: | |
350 | c-basic-offset:2 | |
351 | comment-column:40 | |
352 | fill-column:79 | |
353 | indent-tabs-mode:nil | |
354 | End: | |
355 | */ |