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1c3f1e73 | 1 | /* |
2 | * This file is part of DisOrder | |
5aff007d | 3 | * Copyright (C) 2005-2008 Richard Kettlewell |
1c3f1e73 | 4 | * |
e7eb3a27 | 5 | * This program is free software: you can redistribute it and/or modify |
1c3f1e73 | 6 | * it under the terms of the GNU General Public License as published by |
e7eb3a27 | 7 | * the Free Software Foundation, either version 3 of the License, or |
1c3f1e73 | 8 | * (at your option) any later version. |
9 | * | |
e7eb3a27 RK |
10 | * This program is distributed in the hope that it will be useful, |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
1c3f1e73 | 15 | * You should have received a copy of the GNU General Public License |
e7eb3a27 | 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
1c3f1e73 | 17 | */ |
18 | /** @file server/speaker-network.c | |
19 | * @brief Support for @ref BACKEND_NETWORK */ | |
20 | ||
05b75f8d | 21 | #include "common.h" |
1c3f1e73 | 22 | |
23 | #include <unistd.h> | |
24 | #include <poll.h> | |
25 | #include <netdb.h> | |
26 | #include <gcrypt.h> | |
27 | #include <sys/socket.h> | |
28 | #include <sys/uio.h> | |
81b1bf12 | 29 | #include <net/if.h> |
db2c19dc | 30 | #include <ifaddrs.h> |
6d2d327c | 31 | #include <errno.h> |
edbd470f | 32 | #include <netinet/in.h> |
1c3f1e73 | 33 | |
34 | #include "configuration.h" | |
35 | #include "syscalls.h" | |
36 | #include "log.h" | |
37 | #include "addr.h" | |
38 | #include "timeval.h" | |
39 | #include "rtp.h" | |
81b1bf12 | 40 | #include "ifreq.h" |
1c3f1e73 | 41 | #include "speaker-protocol.h" |
42 | #include "speaker.h" | |
43 | ||
44 | /** @brief Network socket | |
45 | * | |
46 | * This is the file descriptor to write to for @ref BACKEND_NETWORK. | |
47 | */ | |
48 | static int bfd = -1; | |
49 | ||
50 | /** @brief RTP timestamp | |
51 | * | |
52 | * This counts the number of samples played (NB not the number of frames | |
53 | * played). | |
54 | * | |
55 | * The timestamp in the packet header is only 32 bits wide. With 44100Hz | |
56 | * stereo, that only gives about half a day before wrapping, which is not | |
57 | * particularly convenient for certain debugging purposes. Therefore the | |
58 | * timestamp is maintained as a 64-bit integer, giving around six million years | |
59 | * before wrapping, and truncated to 32 bits when transmitting. | |
60 | */ | |
61 | static uint64_t rtp_time; | |
62 | ||
63 | /** @brief RTP base timestamp | |
64 | * | |
65 | * This is the real time correspoding to an @ref rtp_time of 0. It is used | |
66 | * to recalculate the timestamp after idle periods. | |
67 | */ | |
68 | static struct timeval rtp_time_0; | |
69 | ||
70 | /** @brief RTP packet sequence number */ | |
71 | static uint16_t rtp_seq; | |
72 | ||
73 | /** @brief RTP SSRC */ | |
74 | static uint32_t rtp_id; | |
75 | ||
76 | /** @brief Error counter */ | |
77 | static int audio_errors; | |
78 | ||
79 | /** @brief Network backend initialization */ | |
80 | static void network_init(void) { | |
81 | struct addrinfo *res, *sres; | |
82 | static const struct addrinfo pref = { | |
66613034 RK |
83 | .ai_flags = 0, |
84 | .ai_family = PF_INET, | |
85 | .ai_socktype = SOCK_DGRAM, | |
86 | .ai_protocol = IPPROTO_UDP, | |
1c3f1e73 | 87 | }; |
88 | static const struct addrinfo prefbind = { | |
66613034 RK |
89 | .ai_flags = AI_PASSIVE, |
90 | .ai_family = PF_INET, | |
91 | .ai_socktype = SOCK_DGRAM, | |
92 | .ai_protocol = IPPROTO_UDP, | |
1c3f1e73 | 93 | }; |
94 | static const int one = 1; | |
db2c19dc | 95 | int sndbuf, target_sndbuf = 131072; |
1c3f1e73 | 96 | socklen_t len; |
97 | char *sockname, *ssockname; | |
98 | ||
99 | res = get_address(&config->broadcast, &pref, &sockname); | |
100 | if(!res) exit(-1); | |
101 | if(config->broadcast_from.n) { | |
102 | sres = get_address(&config->broadcast_from, &prefbind, &ssockname); | |
103 | if(!sres) exit(-1); | |
104 | } else | |
105 | sres = 0; | |
106 | if((bfd = socket(res->ai_family, | |
107 | res->ai_socktype, | |
108 | res->ai_protocol)) < 0) | |
109 | fatal(errno, "error creating broadcast socket"); | |
6fba990c | 110 | if(multicast(res->ai_addr)) { |
23205f9c RK |
111 | /* Multicasting */ |
112 | switch(res->ai_family) { | |
113 | case PF_INET: { | |
114 | const int mttl = config->multicast_ttl; | |
115 | if(setsockopt(bfd, IPPROTO_IP, IP_MULTICAST_TTL, &mttl, sizeof mttl) < 0) | |
116 | fatal(errno, "error setting IP_MULTICAST_TTL on multicast socket"); | |
61941295 RK |
117 | if(setsockopt(bfd, IPPROTO_IP, IP_MULTICAST_LOOP, |
118 | &config->multicast_loop, sizeof one) < 0) | |
119 | fatal(errno, "error setting IP_MULTICAST_LOOP on multicast socket"); | |
23205f9c RK |
120 | break; |
121 | } | |
122 | case PF_INET6: { | |
123 | const int mttl = config->multicast_ttl; | |
124 | if(setsockopt(bfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, | |
125 | &mttl, sizeof mttl) < 0) | |
126 | fatal(errno, "error setting IPV6_MULTICAST_HOPS on multicast socket"); | |
61941295 RK |
127 | if(setsockopt(bfd, IPPROTO_IP, IPV6_MULTICAST_LOOP, |
128 | &config->multicast_loop, sizeof (int)) < 0) | |
129 | fatal(errno, "error setting IPV6_MULTICAST_LOOP on multicast socket"); | |
23205f9c RK |
130 | break; |
131 | } | |
132 | default: | |
133 | fatal(0, "unsupported address family %d", res->ai_family); | |
134 | } | |
81b1bf12 | 135 | info("multicasting on %s", sockname); |
23205f9c | 136 | } else { |
db2c19dc | 137 | struct ifaddrs *ifs; |
81b1bf12 | 138 | |
db2c19dc RK |
139 | if(getifaddrs(&ifs) < 0) |
140 | fatal(errno, "error calling getifaddrs"); | |
141 | while(ifs) { | |
3aa6f359 RK |
142 | /* (At least on Darwin) IFF_BROADCAST might be set but ifa_broadaddr |
143 | * still a null pointer. It turns out that there's a subsequent entry | |
144 | * for he same interface which _does_ have ifa_broadaddr though... */ | |
db2c19dc | 145 | if((ifs->ifa_flags & IFF_BROADCAST) |
3aa6f359 | 146 | && ifs->ifa_broadaddr |
db2c19dc | 147 | && sockaddr_equal(ifs->ifa_broadaddr, res->ai_addr)) |
81b1bf12 | 148 | break; |
db2c19dc | 149 | ifs = ifs->ifa_next; |
81b1bf12 | 150 | } |
db2c19dc | 151 | if(ifs) { |
81b1bf12 RK |
152 | if(setsockopt(bfd, SOL_SOCKET, SO_BROADCAST, &one, sizeof one) < 0) |
153 | fatal(errno, "error setting SO_BROADCAST on broadcast socket"); | |
db2c19dc | 154 | info("broadcasting on %s (%s)", sockname, ifs->ifa_name); |
81b1bf12 RK |
155 | } else |
156 | info("unicasting on %s", sockname); | |
23205f9c | 157 | } |
1c3f1e73 | 158 | len = sizeof sndbuf; |
159 | if(getsockopt(bfd, SOL_SOCKET, SO_SNDBUF, | |
160 | &sndbuf, &len) < 0) | |
161 | fatal(errno, "error getting SO_SNDBUF"); | |
162 | if(target_sndbuf > sndbuf) { | |
163 | if(setsockopt(bfd, SOL_SOCKET, SO_SNDBUF, | |
164 | &target_sndbuf, sizeof target_sndbuf) < 0) | |
165 | error(errno, "error setting SO_SNDBUF to %d", target_sndbuf); | |
166 | else | |
167 | info("changed socket send buffer size from %d to %d", | |
168 | sndbuf, target_sndbuf); | |
169 | } else | |
170 | info("default socket send buffer is %d", | |
171 | sndbuf); | |
172 | /* We might well want to set additional broadcast- or multicast-related | |
173 | * options here */ | |
174 | if(sres && bind(bfd, sres->ai_addr, sres->ai_addrlen) < 0) | |
175 | fatal(errno, "error binding broadcast socket to %s", ssockname); | |
176 | if(connect(bfd, res->ai_addr, res->ai_addrlen) < 0) | |
177 | fatal(errno, "error connecting broadcast socket to %s", sockname); | |
178 | /* Select an SSRC */ | |
179 | gcry_randomize(&rtp_id, sizeof rtp_id, GCRY_STRONG_RANDOM); | |
1c3f1e73 | 180 | } |
181 | ||
182 | /** @brief Play over the network */ | |
183 | static size_t network_play(size_t frames) { | |
184 | struct rtp_header header; | |
185 | struct iovec vec[2]; | |
6d2d327c | 186 | size_t bytes = frames * bpf, written_frames; |
1c3f1e73 | 187 | int written_bytes; |
188 | /* We transmit using RTP (RFC3550) and attempt to conform to the internet | |
189 | * AVT profile (RFC3551). */ | |
190 | ||
23741390 RK |
191 | /* If we're starting then initialize the base time */ |
192 | if(!rtp_time) | |
193 | xgettimeofday(&rtp_time_0, 0); | |
1c3f1e73 | 194 | if(idled) { |
195 | /* There may have been a gap. Fix up the RTP time accordingly. */ | |
196 | struct timeval now; | |
197 | uint64_t delta; | |
198 | uint64_t target_rtp_time; | |
199 | ||
200 | /* Find the current time */ | |
201 | xgettimeofday(&now, 0); | |
202 | /* Find the number of microseconds elapsed since rtp_time=0 */ | |
203 | delta = tvsub_us(now, rtp_time_0); | |
23741390 | 204 | if(delta > UINT64_MAX / 88200) |
74cfbeaa | 205 | fatal(0, "rtp_time=%"PRIu64" now=%ld.%06ld rtp_time_0=%ld.%06ld delta=%"PRIu64" (%"PRId64")", |
23741390 RK |
206 | rtp_time, |
207 | (long)now.tv_sec, (long)now.tv_usec, | |
208 | (long)rtp_time_0.tv_sec, (long)rtp_time_0.tv_usec, | |
209 | delta, delta); | |
6d2d327c RK |
210 | target_rtp_time = (delta * config->sample_format.rate |
211 | * config->sample_format.channels) / 1000000; | |
1c3f1e73 | 212 | /* Overflows at ~6 years uptime with 44100Hz stereo */ |
213 | ||
214 | /* rtp_time is the number of samples we've played. NB that we play | |
215 | * RTP_AHEAD_MS ahead of ourselves, so it may legitimately be ahead of | |
216 | * the value we deduce from time comparison. | |
217 | * | |
218 | * Suppose we have 1s track started at t=0, and another track begins to | |
24d6fd25 RK |
219 | * play at t=2s. Suppose 44100Hz stereo. We send 1s of audio over the |
220 | * next (about) one second, giving rtp_time=88200. rtp_time stops at this | |
221 | * point. | |
1c3f1e73 | 222 | * |
223 | * At t=2s we'll have calculated target_rtp_time=176400. In this case we | |
224 | * set rtp_time=176400 and the player can correctly conclude that it | |
225 | * should leave 1s between the tracks. | |
226 | * | |
24d6fd25 RK |
227 | * It's never right to reduce rtp_time, for that would imply packets with |
228 | * overlapping timestamp ranges, which does not make sense. | |
1c3f1e73 | 229 | */ |
230 | target_rtp_time &= ~(uint64_t)1; /* stereo! */ | |
231 | if(target_rtp_time > rtp_time) { | |
232 | /* More time has elapsed than we've transmitted samples. That implies | |
233 | * we've been 'sending' silence. */ | |
234 | info("advancing rtp_time by %"PRIu64" samples", | |
235 | target_rtp_time - rtp_time); | |
236 | rtp_time = target_rtp_time; | |
237 | } else if(target_rtp_time < rtp_time) { | |
24d6fd25 RK |
238 | info("would reverse rtp_time by %"PRIu64" samples", |
239 | rtp_time - target_rtp_time); | |
1c3f1e73 | 240 | } |
241 | } | |
242 | header.vpxcc = 2 << 6; /* V=2, P=0, X=0, CC=0 */ | |
243 | header.seq = htons(rtp_seq++); | |
244 | header.timestamp = htonl((uint32_t)rtp_time); | |
245 | header.ssrc = rtp_id; | |
246 | header.mpt = (idled ? 0x80 : 0x00) | 10; | |
247 | /* 10 = L16 = 16-bit x 2 x 44100KHz. We ought to deduce this value from | |
248 | * the sample rate (in a library somewhere so that configuration.c can rule | |
249 | * out invalid rates). | |
250 | */ | |
251 | idled = 0; | |
252 | if(bytes > NETWORK_BYTES - sizeof header) { | |
253 | bytes = NETWORK_BYTES - sizeof header; | |
254 | /* Always send a whole number of frames */ | |
6d2d327c | 255 | bytes -= bytes % bpf; |
1c3f1e73 | 256 | } |
257 | /* "The RTP clock rate used for generating the RTP timestamp is independent | |
258 | * of the number of channels and the encoding; it equals the number of | |
259 | * sampling periods per second. For N-channel encodings, each sampling | |
260 | * period (say, 1/8000 of a second) generates N samples. (This terminology | |
261 | * is standard, but somewhat confusing, as the total number of samples | |
262 | * generated per second is then the sampling rate times the channel | |
263 | * count.)" | |
264 | */ | |
265 | vec[0].iov_base = (void *)&header; | |
266 | vec[0].iov_len = sizeof header; | |
267 | vec[1].iov_base = playing->buffer + playing->start; | |
268 | vec[1].iov_len = bytes; | |
269 | do { | |
270 | written_bytes = writev(bfd, vec, 2); | |
271 | } while(written_bytes < 0 && errno == EINTR); | |
272 | if(written_bytes < 0) { | |
273 | error(errno, "error transmitting audio data"); | |
274 | ++audio_errors; | |
275 | if(audio_errors == 10) | |
276 | fatal(0, "too many audio errors"); | |
277 | return 0; | |
278 | } else | |
279 | audio_errors /= 2; | |
280 | written_bytes -= sizeof (struct rtp_header); | |
6d2d327c | 281 | written_frames = written_bytes / bpf; |
1c3f1e73 | 282 | /* Advance RTP's notion of the time */ |
6d2d327c | 283 | rtp_time += written_frames * config->sample_format.channels; |
1c3f1e73 | 284 | return written_frames; |
285 | } | |
286 | ||
287 | static int bfd_slot; | |
288 | ||
289 | /** @brief Set up poll array for network play */ | |
e84fb5f0 | 290 | static void network_beforepoll(int *timeoutp) { |
1c3f1e73 | 291 | struct timeval now; |
292 | uint64_t target_us; | |
293 | uint64_t target_rtp_time; | |
e84fb5f0 RK |
294 | const int64_t samples_per_second = config->sample_format.rate |
295 | * config->sample_format.channels; | |
e84fb5f0 | 296 | int64_t lead, ahead_ms; |
1c3f1e73 | 297 | |
298 | /* If we're starting then initialize the base time */ | |
299 | if(!rtp_time) | |
300 | xgettimeofday(&rtp_time_0, 0); | |
24d6fd25 | 301 | /* We send audio data whenever we would otherwise get behind */ |
1c3f1e73 | 302 | xgettimeofday(&now, 0); |
303 | target_us = tvsub_us(now, rtp_time_0); | |
23741390 | 304 | if(target_us > UINT64_MAX / 88200) |
74cfbeaa | 305 | fatal(0, "rtp_time=%"PRIu64" rtp_time_0=%ld.%06ld now=%ld.%06ld target_us=%"PRIu64" (%"PRId64")\n", |
23741390 RK |
306 | rtp_time, |
307 | (long)rtp_time_0.tv_sec, (long)rtp_time_0.tv_usec, | |
308 | (long)now.tv_sec, (long)now.tv_usec, | |
309 | target_us, target_us); | |
1c3f1e73 | 310 | target_rtp_time = (target_us * config->sample_format.rate |
311 | * config->sample_format.channels) | |
312 | / 1000000; | |
24d6fd25 | 313 | /* Lead is how far ahead we are */ |
e84fb5f0 | 314 | lead = rtp_time - target_rtp_time; |
24d6fd25 RK |
315 | if(lead <= 0) |
316 | /* We're behind or even, so we'll need to write as soon as we can */ | |
1c3f1e73 | 317 | bfd_slot = addfd(bfd, POLLOUT); |
e84fb5f0 | 318 | else { |
24d6fd25 RK |
319 | /* We've ahead, we can afford to wait a bit even if the IP stack thinks it |
320 | * can accept more. */ | |
321 | ahead_ms = 1000 * lead / samples_per_second; | |
e84fb5f0 RK |
322 | if(ahead_ms < *timeoutp) |
323 | *timeoutp = ahead_ms; | |
324 | } | |
1c3f1e73 | 325 | } |
326 | ||
327 | /** @brief Process poll() results for network play */ | |
328 | static int network_ready(void) { | |
329 | if(fds[bfd_slot].revents & (POLLOUT | POLLERR)) | |
330 | return 1; | |
331 | else | |
332 | return 0; | |
333 | } | |
334 | ||
335 | const struct speaker_backend network_backend = { | |
336 | BACKEND_NETWORK, | |
6d2d327c | 337 | 0, |
1c3f1e73 | 338 | network_init, |
339 | 0, /* activate */ | |
340 | network_play, | |
341 | 0, /* deactivate */ | |
342 | network_beforepoll, | |
343 | network_ready | |
344 | }; | |
345 | ||
346 | /* | |
347 | Local Variables: | |
348 | c-basic-offset:2 | |
349 | comment-column:40 | |
350 | fill-column:79 | |
351 | indent-tabs-mode:nil | |
352 | End: | |
353 | */ |