summaryrefslogtreecommitdiff
path: root/src/modules/rtp/sap.c
blob: b5d9df62c3f3491891765f3888a04c28d74dfbe7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
/***
  This file is part of PulseAudio.

  Copyright 2006 Lennart Poettering

  PulseAudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2 of the License,
  or (at your option) any later version.

  PulseAudio is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with PulseAudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <time.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>

#ifdef HAVE_SYS_FILIO_H
#include <sys/filio.h>
#endif

#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif

#include <pulse/xmalloc.h>

#include <pulsecore/core-error.h>
#include <pulsecore/core-util.h>
#include <pulsecore/log.h>
#include <pulsecore/macro.h>

#include "sap.h"
#include "sdp.h"

#define MIME_TYPE "application/sdp"

pa_sap_context* pa_sap_context_init_send(pa_sap_context *c, int fd, char *sdp_data) {
    pa_assert(c);
    pa_assert(fd >= 0);
    pa_assert(sdp_data);

    c->fd = fd;
    c->sdp_data = sdp_data;
    c->msg_id_hash = (uint16_t) (rand()*rand());

    return c;
}

void pa_sap_context_destroy(pa_sap_context *c) {
    pa_assert(c);

    pa_close(c->fd);
    pa_xfree(c->sdp_data);
}

int pa_sap_send(pa_sap_context *c, pa_bool_t goodbye) {
    uint32_t header;
    struct sockaddr_storage sa_buf;
    struct sockaddr *sa = (struct sockaddr*) &sa_buf;
    socklen_t salen = sizeof(sa_buf);
    struct iovec iov[4];
    struct msghdr m;
    ssize_t k;

    if (getsockname(c->fd, sa, &salen) < 0) {
        pa_log("getsockname() failed: %s\n", pa_cstrerror(errno));
        return -1;
    }

#ifdef HAVE_IPV6
    pa_assert(sa->sa_family == AF_INET || sa->sa_family == AF_INET6);
#else
    pa_assert(sa->sa_family == AF_INET);
#endif

    header = htonl(((uint32_t) 1 << 29) |
#ifdef HAVE_IPV6
                   (sa->sa_family == AF_INET6 ? (uint32_t) 1 << 28 : 0) |
#endif
                   (goodbye ? (uint32_t) 1 << 26 : 0) |
                   (c->msg_id_hash));

    iov[0].iov_base = &header;
    iov[0].iov_len = sizeof(header);

    if (sa->sa_family == AF_INET) {
        iov[1].iov_base = (void*) &((struct sockaddr_in*) sa)->sin_addr;
        iov[1].iov_len = 4U;
#ifdef HAVE_IPV6
    } else {
        iov[1].iov_base = (void*) &((struct sockaddr_in6*) sa)->sin6_addr;
        iov[1].iov_len = 16U;
#endif
    }

    iov[2].iov_base = (char*) MIME_TYPE;
    iov[2].iov_len = sizeof(MIME_TYPE);

    iov[3].iov_base = c->sdp_data;
    iov[3].iov_len = strlen(c->sdp_data);

    m.msg_name = NULL;
    m.msg_namelen = 0;
    m.msg_iov = iov;
    m.msg_iovlen = 4;
    m.msg_control = NULL;
    m.msg_controllen = 0;
    m.msg_flags = 0;

    if ((k = sendmsg(c->fd, &m, MSG_DONTWAIT)) < 0)
        pa_log_warn("sendmsg() failed: %s\n", pa_cstrerror(errno));

    return (int) k;
}

pa_sap_context* pa_sap_context_init_recv(pa_sap_context *c, int fd) {
    pa_assert(c);
    pa_assert(fd >= 0);

    c->fd = fd;
    c->sdp_data = NULL;
    return c;
}

int pa_sap_recv(pa_sap_context *c, pa_bool_t *goodbye) {
    struct msghdr m;
    struct iovec iov;
    int size;
    char *buf = NULL, *e;
    uint32_t header;
    unsigned six, ac, k;
    ssize_t r;

    pa_assert(c);
    pa_assert(goodbye);

    if (ioctl(c->fd, FIONREAD, &size) < 0) {
        pa_log_warn("FIONREAD failed: %s", pa_cstrerror(errno));
        goto fail;
    }

    buf = pa_xnew(char, (unsigned) size+1);
    buf[size] = 0;

    iov.iov_base = buf;
    iov.iov_len = (size_t) size;

    m.msg_name = NULL;
    m.msg_namelen = 0;
    m.msg_iov = &iov;
    m.msg_iovlen = 1;
    m.msg_control = NULL;
    m.msg_controllen = 0;
    m.msg_flags = 0;

    if ((r = recvmsg(c->fd, &m, 0)) != size) {
        pa_log_warn("recvmsg() failed: %s", r < 0 ? pa_cstrerror(errno) : "size mismatch");
        goto fail;
    }

    if (size < 4) {
        pa_log_warn("SAP packet too short.");
        goto fail;
    }

    memcpy(&header, buf, sizeof(uint32_t));
    header = ntohl(header);

    if (header >> 29 != 1) {
        pa_log_warn("Unsupported SAP version.");
        goto fail;
    }

    if ((header >> 25) & 1) {
        pa_log_warn("Encrypted SAP not supported.");
        goto fail;
    }

    if ((header >> 24) & 1) {
        pa_log_warn("Compressed SAP not supported.");
        goto fail;
    }

    six = (header >> 28) & 1U;
    ac = (header >> 16) & 0xFFU;

    k = 4 + (six ? 16U : 4U) + ac*4U;
    if ((unsigned) size < k) {
        pa_log_warn("SAP packet too short (AD).");
        goto fail;
    }

    e = buf + k;
    size -= (int) k;

    if ((unsigned) size >= sizeof(MIME_TYPE) && !strcmp(e, MIME_TYPE)) {
        e += sizeof(MIME_TYPE);
        size -= (int) sizeof(MIME_TYPE);
    } else if ((unsigned) size < sizeof(PA_SDP_HEADER)-1 || strncmp(e, PA_SDP_HEADER, sizeof(PA_SDP_HEADER)-1)) {
        pa_log_warn("Invalid SDP header.");
        goto fail;
    }

    if (c->sdp_data)
        pa_xfree(c->sdp_data);

    c->sdp_data = pa_xstrndup(e, (unsigned) size);
    pa_xfree(buf);

    *goodbye = !!((header >> 26) & 1);

    return 0;

fail:
    pa_xfree(buf);

    return -1;
}