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7a2c7068 RK |
1 | /* |
2 | * This file is part of DisOrder. | |
3 | * Copyright (C) 2009 Richard Kettlewell | |
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 3 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, | |
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 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
17 | */ | |
e8c185c3 | 18 | /** @file lib/uaudio-rtp.c |
7a2c7068 RK |
19 | * @brief Support for RTP network play backend */ |
20 | #include "common.h" | |
21 | ||
dfa51bb7 | 22 | #include <errno.h> |
60e5bc86 | 23 | #include <sys/socket.h> |
dfa51bb7 RK |
24 | #include <ifaddrs.h> |
25 | #include <net/if.h> | |
adeb58a0 RK |
26 | #include <arpa/inet.h> |
27 | #include <netinet/in.h> | |
dfa51bb7 RK |
28 | #include <gcrypt.h> |
29 | #include <unistd.h> | |
30 | #include <time.h> | |
60e5bc86 | 31 | #include <sys/uio.h> |
7a2c7068 RK |
32 | |
33 | #include "uaudio.h" | |
34 | #include "mem.h" | |
35 | #include "log.h" | |
36 | #include "syscalls.h" | |
dfa51bb7 RK |
37 | #include "rtp.h" |
38 | #include "addr.h" | |
39 | #include "ifreq.h" | |
40 | #include "timeval.h" | |
ba70caca | 41 | #include "configuration.h" |
dfa51bb7 RK |
42 | |
43 | /** @brief Bytes to send per network packet | |
44 | * | |
45 | * This is the maximum number of bytes we pass to write(2); to determine actual | |
46 | * packet sizes, add a UDP header and an IP header (and a link layer header if | |
47 | * it's the link layer size you care about). | |
48 | * | |
49 | * Don't make this too big or arithmetic will start to overflow. | |
50 | */ | |
51 | #define NETWORK_BYTES (1500-8/*UDP*/-40/*IP*/-8/*conservatism*/) | |
52 | ||
53 | /** @brief RTP payload type */ | |
54 | static int rtp_payload; | |
55 | ||
56 | /** @brief RTP output socket */ | |
57 | static int rtp_fd; | |
58 | ||
59 | /** @brief RTP SSRC */ | |
60 | static uint32_t rtp_id; | |
61 | ||
62 | /** @brief RTP sequence number */ | |
63 | static uint16_t rtp_sequence; | |
64 | ||
dfa51bb7 RK |
65 | /** @brief Network error count |
66 | * | |
67 | * If too many errors occur in too short a time, we give up. | |
68 | */ | |
69 | static int rtp_errors; | |
70 | ||
71 | /** @brief Delay threshold in microseconds | |
72 | * | |
73 | * rtp_play() never attempts to introduce a delay shorter than this. | |
74 | */ | |
75 | static int64_t rtp_delay_threshold; | |
7a2c7068 RK |
76 | |
77 | static const char *const rtp_options[] = { | |
dfa51bb7 RK |
78 | "rtp-destination", |
79 | "rtp-destination-port", | |
80 | "rtp-source", | |
81 | "rtp-source-port", | |
82 | "multicast-ttl", | |
83 | "multicast-loop", | |
ec57f6c9 | 84 | "delay-threshold", |
7a2c7068 RK |
85 | NULL |
86 | }; | |
87 | ||
dfa51bb7 RK |
88 | static size_t rtp_play(void *buffer, size_t nsamples) { |
89 | struct rtp_header header; | |
90 | struct iovec vec[2]; | |
dfa51bb7 RK |
91 | |
92 | /* We do as much work as possible before checking what time it is */ | |
93 | /* Fill out header */ | |
94 | header.vpxcc = 2 << 6; /* V=2, P=0, X=0, CC=0 */ | |
95 | header.seq = htons(rtp_sequence++); | |
96 | header.ssrc = rtp_id; | |
ec57f6c9 | 97 | header.mpt = (uaudio_schedule_reactivated ? 0x80 : 0x00) | rtp_payload; |
dfa51bb7 RK |
98 | #if !WORDS_BIGENDIAN |
99 | /* Convert samples to network byte order */ | |
100 | uint16_t *u = buffer, *const limit = u + nsamples; | |
101 | while(u < limit) { | |
102 | *u = htons(*u); | |
103 | ++u; | |
104 | } | |
105 | #endif | |
106 | vec[0].iov_base = (void *)&header; | |
107 | vec[0].iov_len = sizeof header; | |
108 | vec[1].iov_base = buffer; | |
109 | vec[1].iov_len = nsamples * uaudio_sample_size; | |
ec57f6c9 RK |
110 | uaudio_schedule_synchronize(); |
111 | header.timestamp = htonl((uint32_t)uaudio_schedule_timestamp); | |
dfa51bb7 RK |
112 | int written_bytes; |
113 | do { | |
114 | written_bytes = writev(rtp_fd, vec, 2); | |
115 | } while(written_bytes < 0 && errno == EINTR); | |
116 | if(written_bytes < 0) { | |
117 | error(errno, "error transmitting audio data"); | |
118 | ++rtp_errors; | |
119 | if(rtp_errors == 10) | |
120 | fatal(0, "too many audio tranmission errors"); | |
121 | return 0; | |
122 | } else | |
123 | rtp_errors /= 2; /* gradual decay */ | |
124 | written_bytes -= sizeof (struct rtp_header); | |
ec57f6c9 RK |
125 | const size_t written_samples = written_bytes / uaudio_sample_size; |
126 | uaudio_schedule_update(written_samples); | |
dfa51bb7 RK |
127 | return written_samples; |
128 | } | |
129 | ||
130 | static void rtp_open(void) { | |
131 | struct addrinfo *res, *sres; | |
132 | static const struct addrinfo pref = { | |
133 | .ai_flags = 0, | |
134 | .ai_family = PF_INET, | |
135 | .ai_socktype = SOCK_DGRAM, | |
136 | .ai_protocol = IPPROTO_UDP, | |
137 | }; | |
138 | static const struct addrinfo prefbind = { | |
139 | .ai_flags = AI_PASSIVE, | |
140 | .ai_family = PF_INET, | |
141 | .ai_socktype = SOCK_DGRAM, | |
142 | .ai_protocol = IPPROTO_UDP, | |
143 | }; | |
144 | static const int one = 1; | |
145 | int sndbuf, target_sndbuf = 131072; | |
146 | socklen_t len; | |
147 | char *sockname, *ssockname; | |
148 | struct stringlist dst, src; | |
dfa51bb7 RK |
149 | |
150 | /* Get configuration */ | |
151 | dst.n = 2; | |
152 | dst.s = xcalloc(2, sizeof *dst.s); | |
b50cfb8a RK |
153 | dst.s[0] = uaudio_get("rtp-destination", NULL); |
154 | dst.s[1] = uaudio_get("rtp-destination-port", NULL); | |
dfa51bb7 RK |
155 | src.n = 2; |
156 | src.s = xcalloc(2, sizeof *dst.s); | |
b50cfb8a RK |
157 | src.s[0] = uaudio_get("rtp-source", NULL); |
158 | src.s[1] = uaudio_get("rtp-source-port", NULL); | |
dfa51bb7 RK |
159 | if(!dst.s[0]) |
160 | fatal(0, "'rtp-destination' not set"); | |
161 | if(!dst.s[1]) | |
162 | fatal(0, "'rtp-destination-port' not set"); | |
163 | if(src.s[0]) { | |
164 | if(!src.s[1]) | |
165 | fatal(0, "'rtp-source-port' not set"); | |
166 | src.n = 2; | |
167 | } else | |
168 | src.n = 0; | |
b50cfb8a RK |
169 | rtp_delay_threshold = atoi(uaudio_get("rtp-delay-threshold", "1000")); |
170 | /* ...microseconds */ | |
dfa51bb7 RK |
171 | |
172 | /* Resolve addresses */ | |
173 | res = get_address(&dst, &pref, &sockname); | |
174 | if(!res) exit(-1); | |
175 | if(src.n) { | |
176 | sres = get_address(&src, &prefbind, &ssockname); | |
177 | if(!sres) exit(-1); | |
178 | } else | |
179 | sres = 0; | |
180 | /* Create the socket */ | |
181 | if((rtp_fd = socket(res->ai_family, | |
182 | res->ai_socktype, | |
183 | res->ai_protocol)) < 0) | |
184 | fatal(errno, "error creating broadcast socket"); | |
185 | if(multicast(res->ai_addr)) { | |
186 | /* Enable multicast options */ | |
b50cfb8a RK |
187 | const int ttl = atoi(uaudio_get("multicast-ttl", "1")); |
188 | const int loop = !strcmp(uaudio_get("multicast-loop", "yes"), "yes"); | |
dfa51bb7 RK |
189 | switch(res->ai_family) { |
190 | case PF_INET: { | |
191 | if(setsockopt(rtp_fd, IPPROTO_IP, IP_MULTICAST_TTL, | |
192 | &ttl, sizeof ttl) < 0) | |
193 | fatal(errno, "error setting IP_MULTICAST_TTL on multicast socket"); | |
194 | if(setsockopt(rtp_fd, IPPROTO_IP, IP_MULTICAST_LOOP, | |
195 | &loop, sizeof loop) < 0) | |
196 | fatal(errno, "error setting IP_MULTICAST_LOOP on multicast socket"); | |
197 | break; | |
198 | } | |
199 | case PF_INET6: { | |
200 | if(setsockopt(rtp_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, | |
201 | &ttl, sizeof ttl) < 0) | |
202 | fatal(errno, "error setting IPV6_MULTICAST_HOPS on multicast socket"); | |
203 | if(setsockopt(rtp_fd, IPPROTO_IP, IPV6_MULTICAST_LOOP, | |
204 | &loop, sizeof loop) < 0) | |
205 | fatal(errno, "error setting IPV6_MULTICAST_LOOP on multicast socket"); | |
206 | break; | |
207 | } | |
208 | default: | |
209 | fatal(0, "unsupported address family %d", res->ai_family); | |
210 | } | |
211 | info("multicasting on %s TTL=%d loop=%s", | |
212 | sockname, ttl, loop ? "yes" : "no"); | |
213 | } else { | |
214 | struct ifaddrs *ifs; | |
215 | ||
216 | if(getifaddrs(&ifs) < 0) | |
217 | fatal(errno, "error calling getifaddrs"); | |
218 | while(ifs) { | |
219 | /* (At least on Darwin) IFF_BROADCAST might be set but ifa_broadaddr | |
220 | * still a null pointer. It turns out that there's a subsequent entry | |
221 | * for he same interface which _does_ have ifa_broadaddr though... */ | |
222 | if((ifs->ifa_flags & IFF_BROADCAST) | |
223 | && ifs->ifa_broadaddr | |
224 | && sockaddr_equal(ifs->ifa_broadaddr, res->ai_addr)) | |
225 | break; | |
226 | ifs = ifs->ifa_next; | |
227 | } | |
228 | if(ifs) { | |
229 | if(setsockopt(rtp_fd, SOL_SOCKET, SO_BROADCAST, &one, sizeof one) < 0) | |
230 | fatal(errno, "error setting SO_BROADCAST on broadcast socket"); | |
231 | info("broadcasting on %s (%s)", sockname, ifs->ifa_name); | |
232 | } else | |
233 | info("unicasting on %s", sockname); | |
234 | } | |
235 | /* Enlarge the socket buffer */ | |
236 | len = sizeof sndbuf; | |
237 | if(getsockopt(rtp_fd, SOL_SOCKET, SO_SNDBUF, | |
238 | &sndbuf, &len) < 0) | |
239 | fatal(errno, "error getting SO_SNDBUF"); | |
240 | if(target_sndbuf > sndbuf) { | |
241 | if(setsockopt(rtp_fd, SOL_SOCKET, SO_SNDBUF, | |
242 | &target_sndbuf, sizeof target_sndbuf) < 0) | |
243 | error(errno, "error setting SO_SNDBUF to %d", target_sndbuf); | |
244 | else | |
245 | info("changed socket send buffer size from %d to %d", | |
246 | sndbuf, target_sndbuf); | |
247 | } else | |
248 | info("default socket send buffer is %d", | |
249 | sndbuf); | |
250 | /* We might well want to set additional broadcast- or multicast-related | |
251 | * options here */ | |
252 | if(sres && bind(rtp_fd, sres->ai_addr, sres->ai_addrlen) < 0) | |
253 | fatal(errno, "error binding broadcast socket to %s", ssockname); | |
254 | if(connect(rtp_fd, res->ai_addr, res->ai_addrlen) < 0) | |
255 | fatal(errno, "error connecting broadcast socket to %s", sockname); | |
dfa51bb7 RK |
256 | } |
257 | ||
7a2c7068 RK |
258 | static void rtp_start(uaudio_callback *callback, |
259 | void *userdata) { | |
dfa51bb7 RK |
260 | /* We only support L16 (but we do stereo and mono and will convert sign) */ |
261 | if(uaudio_channels == 2 | |
262 | && uaudio_bits == 16 | |
263 | && uaudio_rate == 44100) | |
264 | rtp_payload = 10; | |
265 | else if(uaudio_channels == 1 | |
266 | && uaudio_bits == 16 | |
267 | && uaudio_rate == 44100) | |
268 | rtp_payload = 11; | |
269 | else | |
270 | fatal(0, "asked for %d/%d/%d 16/44100/1 and 16/44100/2", | |
271 | uaudio_bits, uaudio_rate, uaudio_channels); | |
ec57f6c9 RK |
272 | /* Various fields are required to have random initial values by RFC3550. The |
273 | * packet contents are highly public so there's no point asking for very | |
274 | * strong randomness. */ | |
275 | gcry_create_nonce(&rtp_id, sizeof rtp_id); | |
276 | gcry_create_nonce(&rtp_sequence, sizeof rtp_sequence); | |
dfa51bb7 | 277 | rtp_open(); |
ec57f6c9 | 278 | uaudio_schedule_init(); |
dfa51bb7 RK |
279 | uaudio_thread_start(callback, |
280 | userdata, | |
281 | rtp_play, | |
282 | 256 / uaudio_sample_size, | |
283 | (NETWORK_BYTES - sizeof(struct rtp_header)) | |
284 | / uaudio_sample_size); | |
7a2c7068 RK |
285 | } |
286 | ||
287 | static void rtp_stop(void) { | |
dfa51bb7 RK |
288 | uaudio_thread_stop(); |
289 | close(rtp_fd); | |
290 | rtp_fd = -1; | |
7a2c7068 RK |
291 | } |
292 | ||
293 | static void rtp_activate(void) { | |
ec57f6c9 | 294 | uaudio_schedule_reactivated = 1; |
dfa51bb7 | 295 | uaudio_thread_activate(); |
7a2c7068 RK |
296 | } |
297 | ||
298 | static void rtp_deactivate(void) { | |
dfa51bb7 | 299 | uaudio_thread_deactivate(); |
7a2c7068 RK |
300 | } |
301 | ||
ba70caca RK |
302 | static void rtp_configure(void) { |
303 | char buffer[64]; | |
304 | ||
305 | uaudio_set("rtp-destination", config->broadcast.s[0]); | |
306 | uaudio_set("rtp-destination-port", config->broadcast.s[1]); | |
307 | if(config->broadcast_from.n) { | |
308 | uaudio_set("rtp-source", config->broadcast_from.s[0]); | |
309 | uaudio_set("rtp-source-port", config->broadcast_from.s[0]); | |
310 | } else { | |
311 | uaudio_set("rtp-source", NULL); | |
312 | uaudio_set("rtp-source-port", NULL); | |
313 | } | |
314 | snprintf(buffer, sizeof buffer, "%ld", config->multicast_ttl); | |
315 | uaudio_set("multicast-ttl", buffer); | |
316 | uaudio_set("multicast-loop", config->multicast_loop ? "yes" : "no"); | |
317 | snprintf(buffer, sizeof buffer, "%ld", config->rtp_delay_threshold); | |
318 | uaudio_set("delay-threshold", buffer); | |
319 | } | |
320 | ||
7a2c7068 RK |
321 | const struct uaudio uaudio_rtp = { |
322 | .name = "rtp", | |
323 | .options = rtp_options, | |
324 | .start = rtp_start, | |
325 | .stop = rtp_stop, | |
326 | .activate = rtp_activate, | |
ba70caca RK |
327 | .deactivate = rtp_deactivate, |
328 | .configure = rtp_configure, | |
7a2c7068 RK |
329 | }; |
330 | ||
331 | /* | |
332 | Local Variables: | |
333 | c-basic-offset:2 | |
334 | comment-column:40 | |
335 | fill-column:79 | |
336 | indent-tabs-mode:nil | |
337 | End: | |
338 | */ |