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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 | ||
b1f6ca8c RK |
62 | /** @brief Base for timestamp */ |
63 | static uint32_t rtp_base; | |
64 | ||
dfa51bb7 RK |
65 | /** @brief RTP sequence number */ |
66 | static uint16_t rtp_sequence; | |
67 | ||
dfa51bb7 RK |
68 | /** @brief Network error count |
69 | * | |
70 | * If too many errors occur in too short a time, we give up. | |
71 | */ | |
72 | static int rtp_errors; | |
73 | ||
b1f6ca8c RK |
74 | /** @brief Set while paused */ |
75 | static volatile int rtp_paused; | |
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", | |
7a2c7068 RK |
84 | NULL |
85 | }; | |
86 | ||
76e72f65 RK |
87 | static void rtp_get_netconfig(const char *af, |
88 | const char *addr, | |
89 | const char *port, | |
90 | struct netaddress *na) { | |
91 | char *vec[3]; | |
92 | ||
93 | vec[0] = uaudio_get(af, NULL); | |
94 | vec[1] = uaudio_get(addr, NULL); | |
95 | vec[2] = uaudio_get(port, NULL); | |
96 | if(!*vec) | |
97 | na->af = -1; | |
98 | else | |
99 | if(netaddress_parse(na, 3, vec)) | |
100 | fatal(0, "invalid RTP address"); | |
101 | } | |
102 | ||
103 | static void rtp_set_netconfig(const char *af, | |
104 | const char *addr, | |
105 | const char *port, | |
106 | const struct netaddress *na) { | |
107 | uaudio_set(af, NULL); | |
108 | uaudio_set(addr, NULL); | |
109 | uaudio_set(port, NULL); | |
110 | if(na->af != -1) { | |
111 | int nvec; | |
112 | char **vec; | |
113 | ||
114 | netaddress_format(na, &nvec, &vec); | |
115 | if(nvec > 0) { | |
116 | uaudio_set(af, vec[0]); | |
117 | xfree(vec[0]); | |
118 | } | |
119 | if(nvec > 1) { | |
120 | uaudio_set(addr, vec[1]); | |
121 | xfree(vec[1]); | |
122 | } | |
123 | if(nvec > 2) { | |
124 | uaudio_set(port, vec[2]); | |
125 | xfree(vec[2]); | |
126 | } | |
127 | xfree(vec); | |
128 | } | |
129 | } | |
130 | ||
b1f6ca8c | 131 | static size_t rtp_play(void *buffer, size_t nsamples, unsigned flags) { |
dfa51bb7 RK |
132 | struct rtp_header header; |
133 | struct iovec vec[2]; | |
b1f6ca8c RK |
134 | |
135 | #if 0 | |
136 | if(flags & (UAUDIO_PAUSE|UAUDIO_RESUME)) | |
137 | fprintf(stderr, "rtp_play %zu samples%s%s%s%s\n", nsamples, | |
138 | flags & UAUDIO_PAUSE ? " UAUDIO_PAUSE" : "", | |
139 | flags & UAUDIO_RESUME ? " UAUDIO_RESUME" : "", | |
140 | flags & UAUDIO_PLAYING ? " UAUDIO_PLAYING" : "", | |
141 | flags & UAUDIO_PAUSED ? " UAUDIO_PAUSED" : ""); | |
142 | #endif | |
143 | ||
dfa51bb7 RK |
144 | /* We do as much work as possible before checking what time it is */ |
145 | /* Fill out header */ | |
146 | header.vpxcc = 2 << 6; /* V=2, P=0, X=0, CC=0 */ | |
147 | header.seq = htons(rtp_sequence++); | |
148 | header.ssrc = rtp_id; | |
b1f6ca8c RK |
149 | header.mpt = rtp_payload; |
150 | /* If we've come out of a pause, set the marker bit */ | |
151 | if(flags & UAUDIO_RESUME) | |
152 | header.mpt |= 0x80; | |
dfa51bb7 RK |
153 | #if !WORDS_BIGENDIAN |
154 | /* Convert samples to network byte order */ | |
155 | uint16_t *u = buffer, *const limit = u + nsamples; | |
156 | while(u < limit) { | |
157 | *u = htons(*u); | |
158 | ++u; | |
159 | } | |
160 | #endif | |
161 | vec[0].iov_base = (void *)&header; | |
162 | vec[0].iov_len = sizeof header; | |
163 | vec[1].iov_base = buffer; | |
164 | vec[1].iov_len = nsamples * uaudio_sample_size; | |
b1f6ca8c RK |
165 | const uint32_t timestamp = uaudio_schedule_sync(); |
166 | header.timestamp = htonl(rtp_base + (uint32_t)timestamp); | |
167 | /* If we're paused don't actually end a packet, we just pretend */ | |
168 | if(flags & UAUDIO_PAUSED) { | |
169 | uaudio_schedule_sent(nsamples); | |
170 | return nsamples; | |
171 | } | |
dfa51bb7 RK |
172 | int written_bytes; |
173 | do { | |
174 | written_bytes = writev(rtp_fd, vec, 2); | |
175 | } while(written_bytes < 0 && errno == EINTR); | |
176 | if(written_bytes < 0) { | |
177 | error(errno, "error transmitting audio data"); | |
178 | ++rtp_errors; | |
179 | if(rtp_errors == 10) | |
180 | fatal(0, "too many audio tranmission errors"); | |
181 | return 0; | |
182 | } else | |
183 | rtp_errors /= 2; /* gradual decay */ | |
b1f6ca8c RK |
184 | /* TODO what can we sensibly do about short writes here? Really that's just |
185 | * an error and we ought to be using smaller packets. */ | |
186 | uaudio_schedule_sent(nsamples); | |
187 | return nsamples; | |
dfa51bb7 RK |
188 | } |
189 | ||
190 | static void rtp_open(void) { | |
191 | struct addrinfo *res, *sres; | |
dfa51bb7 RK |
192 | static const int one = 1; |
193 | int sndbuf, target_sndbuf = 131072; | |
194 | socklen_t len; | |
76e72f65 | 195 | struct netaddress dst[1], src[1]; |
dfa51bb7 RK |
196 | |
197 | /* Get configuration */ | |
76e72f65 RK |
198 | rtp_get_netconfig("rtp-destination-af", |
199 | "rtp-destination", | |
200 | "rtp-destination-port", | |
201 | dst); | |
202 | rtp_get_netconfig("rtp-source-af", | |
203 | "rtp-source", | |
204 | "rtp-source-port", | |
205 | src); | |
b50cfb8a | 206 | /* ...microseconds */ |
dfa51bb7 RK |
207 | |
208 | /* Resolve addresses */ | |
76e72f65 RK |
209 | res = netaddress_resolve(dst, 0, IPPROTO_UDP); |
210 | if(!res) | |
211 | exit(-1); | |
212 | if(src->af != -1) { | |
213 | sres = netaddress_resolve(src, 1, IPPROTO_UDP); | |
214 | if(!sres) | |
215 | exit(-1); | |
dfa51bb7 RK |
216 | } else |
217 | sres = 0; | |
218 | /* Create the socket */ | |
219 | if((rtp_fd = socket(res->ai_family, | |
220 | res->ai_socktype, | |
221 | res->ai_protocol)) < 0) | |
222 | fatal(errno, "error creating broadcast socket"); | |
223 | if(multicast(res->ai_addr)) { | |
224 | /* Enable multicast options */ | |
b50cfb8a RK |
225 | const int ttl = atoi(uaudio_get("multicast-ttl", "1")); |
226 | const int loop = !strcmp(uaudio_get("multicast-loop", "yes"), "yes"); | |
dfa51bb7 RK |
227 | switch(res->ai_family) { |
228 | case PF_INET: { | |
229 | if(setsockopt(rtp_fd, IPPROTO_IP, IP_MULTICAST_TTL, | |
230 | &ttl, sizeof ttl) < 0) | |
231 | fatal(errno, "error setting IP_MULTICAST_TTL on multicast socket"); | |
232 | if(setsockopt(rtp_fd, IPPROTO_IP, IP_MULTICAST_LOOP, | |
233 | &loop, sizeof loop) < 0) | |
234 | fatal(errno, "error setting IP_MULTICAST_LOOP on multicast socket"); | |
235 | break; | |
236 | } | |
237 | case PF_INET6: { | |
238 | if(setsockopt(rtp_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, | |
239 | &ttl, sizeof ttl) < 0) | |
240 | fatal(errno, "error setting IPV6_MULTICAST_HOPS on multicast socket"); | |
241 | if(setsockopt(rtp_fd, IPPROTO_IP, IPV6_MULTICAST_LOOP, | |
242 | &loop, sizeof loop) < 0) | |
243 | fatal(errno, "error setting IPV6_MULTICAST_LOOP on multicast socket"); | |
244 | break; | |
245 | } | |
246 | default: | |
247 | fatal(0, "unsupported address family %d", res->ai_family); | |
248 | } | |
249 | info("multicasting on %s TTL=%d loop=%s", | |
76e72f65 | 250 | format_sockaddr(res->ai_addr), ttl, loop ? "yes" : "no"); |
dfa51bb7 RK |
251 | } else { |
252 | struct ifaddrs *ifs; | |
253 | ||
254 | if(getifaddrs(&ifs) < 0) | |
255 | fatal(errno, "error calling getifaddrs"); | |
256 | while(ifs) { | |
257 | /* (At least on Darwin) IFF_BROADCAST might be set but ifa_broadaddr | |
258 | * still a null pointer. It turns out that there's a subsequent entry | |
259 | * for he same interface which _does_ have ifa_broadaddr though... */ | |
260 | if((ifs->ifa_flags & IFF_BROADCAST) | |
261 | && ifs->ifa_broadaddr | |
262 | && sockaddr_equal(ifs->ifa_broadaddr, res->ai_addr)) | |
263 | break; | |
264 | ifs = ifs->ifa_next; | |
265 | } | |
266 | if(ifs) { | |
267 | if(setsockopt(rtp_fd, SOL_SOCKET, SO_BROADCAST, &one, sizeof one) < 0) | |
268 | fatal(errno, "error setting SO_BROADCAST on broadcast socket"); | |
76e72f65 RK |
269 | info("broadcasting on %s (%s)", |
270 | format_sockaddr(res->ai_addr), ifs->ifa_name); | |
dfa51bb7 | 271 | } else |
76e72f65 | 272 | info("unicasting on %s", format_sockaddr(res->ai_addr)); |
dfa51bb7 RK |
273 | } |
274 | /* Enlarge the socket buffer */ | |
275 | len = sizeof sndbuf; | |
276 | if(getsockopt(rtp_fd, SOL_SOCKET, SO_SNDBUF, | |
277 | &sndbuf, &len) < 0) | |
278 | fatal(errno, "error getting SO_SNDBUF"); | |
279 | if(target_sndbuf > sndbuf) { | |
280 | if(setsockopt(rtp_fd, SOL_SOCKET, SO_SNDBUF, | |
281 | &target_sndbuf, sizeof target_sndbuf) < 0) | |
282 | error(errno, "error setting SO_SNDBUF to %d", target_sndbuf); | |
283 | else | |
284 | info("changed socket send buffer size from %d to %d", | |
285 | sndbuf, target_sndbuf); | |
286 | } else | |
287 | info("default socket send buffer is %d", | |
288 | sndbuf); | |
289 | /* We might well want to set additional broadcast- or multicast-related | |
290 | * options here */ | |
291 | if(sres && bind(rtp_fd, sres->ai_addr, sres->ai_addrlen) < 0) | |
76e72f65 RK |
292 | fatal(errno, "error binding broadcast socket to %s", |
293 | format_sockaddr(sres->ai_addr)); | |
dfa51bb7 | 294 | if(connect(rtp_fd, res->ai_addr, res->ai_addrlen) < 0) |
76e72f65 RK |
295 | fatal(errno, "error connecting broadcast socket to %s", |
296 | format_sockaddr(res->ai_addr)); | |
dfa51bb7 RK |
297 | } |
298 | ||
7a2c7068 RK |
299 | static void rtp_start(uaudio_callback *callback, |
300 | void *userdata) { | |
dfa51bb7 RK |
301 | /* We only support L16 (but we do stereo and mono and will convert sign) */ |
302 | if(uaudio_channels == 2 | |
303 | && uaudio_bits == 16 | |
304 | && uaudio_rate == 44100) | |
305 | rtp_payload = 10; | |
306 | else if(uaudio_channels == 1 | |
307 | && uaudio_bits == 16 | |
308 | && uaudio_rate == 44100) | |
309 | rtp_payload = 11; | |
310 | else | |
311 | fatal(0, "asked for %d/%d/%d 16/44100/1 and 16/44100/2", | |
312 | uaudio_bits, uaudio_rate, uaudio_channels); | |
ec57f6c9 RK |
313 | /* Various fields are required to have random initial values by RFC3550. The |
314 | * packet contents are highly public so there's no point asking for very | |
315 | * strong randomness. */ | |
316 | gcry_create_nonce(&rtp_id, sizeof rtp_id); | |
b1f6ca8c | 317 | gcry_create_nonce(&rtp_base, sizeof rtp_base); |
ec57f6c9 | 318 | gcry_create_nonce(&rtp_sequence, sizeof rtp_sequence); |
dfa51bb7 | 319 | rtp_open(); |
ec57f6c9 | 320 | uaudio_schedule_init(); |
dfa51bb7 RK |
321 | uaudio_thread_start(callback, |
322 | userdata, | |
323 | rtp_play, | |
324 | 256 / uaudio_sample_size, | |
325 | (NETWORK_BYTES - sizeof(struct rtp_header)) | |
63761c19 RK |
326 | / uaudio_sample_size, |
327 | 0); | |
7a2c7068 RK |
328 | } |
329 | ||
330 | static void rtp_stop(void) { | |
dfa51bb7 RK |
331 | uaudio_thread_stop(); |
332 | close(rtp_fd); | |
333 | rtp_fd = -1; | |
7a2c7068 RK |
334 | } |
335 | ||
ba70caca RK |
336 | static void rtp_configure(void) { |
337 | char buffer[64]; | |
338 | ||
76e72f65 RK |
339 | rtp_set_netconfig("rtp-destination-af", |
340 | "rtp-destination", | |
341 | "rtp-destination-port", &config->broadcast); | |
342 | rtp_set_netconfig("rtp-source-af", | |
343 | "rtp-source", | |
344 | "rtp-source-port", &config->broadcast_from); | |
ba70caca RK |
345 | snprintf(buffer, sizeof buffer, "%ld", config->multicast_ttl); |
346 | uaudio_set("multicast-ttl", buffer); | |
347 | uaudio_set("multicast-loop", config->multicast_loop ? "yes" : "no"); | |
ba70caca RK |
348 | } |
349 | ||
7a2c7068 RK |
350 | const struct uaudio uaudio_rtp = { |
351 | .name = "rtp", | |
352 | .options = rtp_options, | |
353 | .start = rtp_start, | |
354 | .stop = rtp_stop, | |
b1f6ca8c RK |
355 | .activate = uaudio_thread_activate, |
356 | .deactivate = uaudio_thread_deactivate, | |
ba70caca | 357 | .configure = rtp_configure, |
7a2c7068 RK |
358 | }; |
359 | ||
360 | /* | |
361 | Local Variables: | |
362 | c-basic-offset:2 | |
363 | comment-column:40 | |
364 | fill-column:79 | |
365 | indent-tabs-mode:nil | |
366 | End: | |
367 | */ |