xref: /third_party/pulseaudio/src/modules/rtp/sdp.c (revision 53a5a1b3)
1/***
2  This file is part of PulseAudio.
3
4  Copyright 2006 Lennart Poettering
5
6  PulseAudio is free software; you can redistribute it and/or modify
7  it under the terms of the GNU Lesser General Public License as published
8  by the Free Software Foundation; either version 2.1 of the License,
9  or (at your option) any later version.
10
11  PulseAudio is distributed in the hope that it will be useful, but
12  WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  General Public License for more details.
15
16  You should have received a copy of the GNU Lesser General Public License
17  along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
18***/
19
20#ifdef HAVE_CONFIG_H
21#include <config.h>
22#endif
23
24#include <time.h>
25#include <stdlib.h>
26#include <sys/types.h>
27#include <sys/socket.h>
28#include <netinet/in.h>
29#include <string.h>
30
31#include <pulse/xmalloc.h>
32#include <pulse/util.h>
33
34#include <pulsecore/core-util.h>
35#include <pulsecore/log.h>
36#include <pulsecore/macro.h>
37#include <pulsecore/arpa-inet.h>
38
39#include "sdp.h"
40#include "rtp.h"
41
42char *pa_sdp_build(int af, const void *src, const void *dst, const char *name, uint16_t port, uint8_t payload, const pa_sample_spec *ss, bool enable_opus) {
43    uint32_t ntp;
44    uint32_t rate, channels;
45    char buf_src[64], buf_dst[64], un[64];
46    const char *u, *f;
47
48    pa_assert(src);
49    pa_assert(dst);
50
51#ifdef HAVE_IPV6
52    pa_assert(af == AF_INET || af == AF_INET6);
53#else
54    pa_assert(af == AF_INET);
55#endif
56
57    if (enable_opus) {
58        f = "OPUS";
59        rate = 48000;
60        channels = 2;
61    } else {
62        pa_assert_se(f = pa_rtp_format_to_string(ss->format));
63        rate = ss->rate;
64        channels = ss->channels;
65    }
66
67    if (!(u = pa_get_user_name(un, sizeof(un))))
68        u = "-";
69
70    ntp = (uint32_t) time(NULL) + 2208988800U;
71
72    pa_assert_se(inet_ntop(af, src, buf_src, sizeof(buf_src)));
73    pa_assert_se(inet_ntop(af, dst, buf_dst, sizeof(buf_dst)));
74
75    return pa_sprintf_malloc(
76            PA_SDP_HEADER
77            "o=%s %lu 0 IN %s %s\n"
78            "s=%s\n"
79            "c=IN %s %s\n"
80            "t=%lu 0\n"
81            "a=recvonly\n"
82            "m=audio %u RTP/AVP %i\n"
83            "a=rtpmap:%i %s/%u/%u\n"
84            "a=type:broadcast\n",
85            u, (unsigned long) ntp, af == AF_INET ? "IP4" : "IP6", buf_src,
86            name,
87            af == AF_INET ? "IP4" : "IP6", buf_dst,
88            (unsigned long) ntp,
89            port, payload,
90            payload, f, rate, channels);
91}
92
93static pa_sample_spec *parse_sdp_sample_spec(pa_sample_spec *ss, char *c) {
94    unsigned rate, channels;
95    pa_assert(ss);
96    pa_assert(c);
97
98    if (pa_startswith(c, "L16/")) {
99        ss->format = PA_SAMPLE_S16BE;
100        c += 4;
101    } else if (pa_startswith(c, "OPUS/")) {
102        ss->format = PA_SAMPLE_S16LE;
103        c += 5;
104    } else
105        return NULL;
106
107    if (sscanf(c, "%u/%u", &rate, &channels) == 2) {
108        ss->rate = (uint32_t) rate;
109        ss->channels = (uint8_t) channels;
110    } else if (sscanf(c, "%u", &rate) == 2) {
111        ss->rate = (uint32_t) rate;
112        ss->channels = 1;
113    } else
114        return NULL;
115
116    if (!pa_sample_spec_valid(ss))
117        return NULL;
118
119    return ss;
120}
121
122pa_sdp_info *pa_sdp_parse(const char *t, pa_sdp_info *i, int is_goodbye) {
123    uint16_t port = 0;
124    bool ss_valid = false;
125
126    pa_assert(t);
127    pa_assert(i);
128
129    i->origin = i->session_name = NULL;
130    i->salen = 0;
131    i->payload = 255;
132    i->enable_opus = false;
133
134    if (!pa_startswith(t, PA_SDP_HEADER)) {
135        pa_log("Failed to parse SDP data: invalid header.");
136        goto fail;
137    }
138
139    t += sizeof(PA_SDP_HEADER)-1;
140
141    while (*t) {
142        size_t l;
143
144        l = strcspn(t, "\n");
145
146        if (l <= 2) {
147            pa_log("Failed to parse SDP data: line too short: >%s<.", t);
148            goto fail;
149        }
150
151        if (pa_startswith(t, "o="))
152            i->origin = pa_xstrndup(t+2, l-2);
153        else if (pa_startswith(t, "s="))
154            i->session_name = pa_xstrndup(t+2, l-2);
155        else if (pa_startswith(t, "c=IN IP4 ")) {
156            char a[64];
157            size_t k;
158
159            k = l-8 > sizeof(a) ? sizeof(a) : l-8;
160
161            pa_strlcpy(a, t+9, k);
162            a[strcspn(a, "/")] = 0;
163
164            if (inet_pton(AF_INET, a, &((struct sockaddr_in*) &i->sa)->sin_addr) <= 0) {
165                pa_log("Failed to parse SDP data: bad address: >%s<.", a);
166                goto fail;
167            }
168
169            ((struct sockaddr_in*) &i->sa)->sin_family = AF_INET;
170            ((struct sockaddr_in*) &i->sa)->sin_port = 0;
171            i->salen = sizeof(struct sockaddr_in);
172#ifdef HAVE_IPV6
173        } else if (pa_startswith(t, "c=IN IP6 ")) {
174            char a[64];
175            size_t k;
176
177            k = l-8 > sizeof(a) ? sizeof(a) : l-8;
178
179            pa_strlcpy(a, t+9, k);
180            a[strcspn(a, "/")] = 0;
181
182            if (inet_pton(AF_INET6, a, &((struct sockaddr_in6*) &i->sa)->sin6_addr) <= 0) {
183                pa_log("Failed to parse SDP data: bad address: >%s<.", a);
184                goto fail;
185            }
186
187            ((struct sockaddr_in6*) &i->sa)->sin6_family = AF_INET6;
188            ((struct sockaddr_in6*) &i->sa)->sin6_port = 0;
189            i->salen = sizeof(struct sockaddr_in6);
190#endif
191        } else if (pa_startswith(t, "m=audio ")) {
192
193            if (i->payload > 127) {
194                int _port, _payload;
195
196                if (sscanf(t+8, "%i RTP/AVP %i", &_port, &_payload) == 2) {
197
198                    if (_port <= 0 || _port > 0xFFFF) {
199                        pa_log("Failed to parse SDP data: invalid port %i.", _port);
200                        goto fail;
201                    }
202
203                    if (_payload < 0 || _payload > 127) {
204                        pa_log("Failed to parse SDP data: invalid payload %i.", _payload);
205                        goto fail;
206                    }
207
208                    port = (uint16_t) _port;
209                    i->payload = (uint8_t) _payload;
210
211                    if (pa_rtp_sample_spec_from_payload(i->payload, &i->sample_spec))
212                        ss_valid = true;
213                }
214            }
215        } else if (pa_startswith(t, "a=rtpmap:")) {
216
217            if (i->payload <= 127) {
218                char c[64];
219                int _payload;
220                int len;
221
222                if (sscanf(t + 9, "%i %n", &_payload, &len) == 1) {
223                    if (_payload < 0 || _payload > 127) {
224                        pa_log("Failed to parse SDP data: invalid payload %i.", _payload);
225                        goto fail;
226                    }
227                    if (_payload == i->payload) {
228                        strncpy(c, t + 9 + len, 63);
229                        c[63] = 0;
230                        c[strcspn(c, "\n")] = 0;
231
232                        if (parse_sdp_sample_spec(&i->sample_spec, c))
233                            ss_valid = true;
234
235                        if (pa_startswith(c, "OPUS/"))
236                            i->enable_opus = true;
237                    }
238                }
239            }
240        }
241
242        t += l;
243
244        if (*t == '\n')
245            t++;
246    }
247
248    if (!i->origin || (!is_goodbye && (!i->salen || i->payload > 127 || !ss_valid || port == 0))) {
249        pa_log("Failed to parse SDP data: missing data.");
250        goto fail;
251    }
252
253    if (((struct sockaddr*) &i->sa)->sa_family == AF_INET)
254        ((struct sockaddr_in*) &i->sa)->sin_port = htons(port);
255    else
256        ((struct sockaddr_in6*) &i->sa)->sin6_port = htons(port);
257
258    return i;
259
260fail:
261    pa_xfree(i->origin);
262    pa_xfree(i->session_name);
263
264    return NULL;
265}
266
267void pa_sdp_info_destroy(pa_sdp_info *i) {
268    pa_assert(i);
269
270    pa_xfree(i->origin);
271    pa_xfree(i->session_name);
272}
273