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
|
/*
* rtp.c
*
* library functions for the real-time transport protocol
*
* David A. McGrew
* Cisco Systems, Inc.
*/
/*
*
* Copyright (c) 2001-2017, Cisco Systems, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* Neither the name of the Cisco Systems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "rtp.h"
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include "cipher_priv.h"
#define PRINT_DEBUG 0 /* set to 1 to print out debugging data */
#define VERBOSE_DEBUG 0 /* set to 1 to print out more data */
int rtp_sendto(rtp_sender_t sender, const void *msg, int len)
{
int octets_sent;
srtp_err_status_t stat;
int pkt_len = len + RTP_HEADER_LEN;
/* marshal data */
strncpy(sender->message.body, msg, len);
/* update header */
sender->message.header.seq = ntohs(sender->message.header.seq) + 1;
sender->message.header.seq = htons(sender->message.header.seq);
sender->message.header.ts = ntohl(sender->message.header.ts) + 1;
sender->message.header.ts = htonl(sender->message.header.ts);
/* apply srtp */
stat = srtp_protect(sender->srtp_ctx, &sender->message.header, &pkt_len);
if (stat) {
#if PRINT_DEBUG
fprintf(stderr, "error: srtp protection failed with code %d\n", stat);
#endif
return -1;
}
#if VERBOSE_DEBUG
srtp_print_packet(&sender->message.header, pkt_len);
#endif
octets_sent =
sendto(sender->socket, (void *)&sender->message, pkt_len, 0,
(struct sockaddr *)&sender->addr, sizeof(struct sockaddr_in));
if (octets_sent != pkt_len) {
#if PRINT_DEBUG
fprintf(stderr, "error: couldn't send message %s", (char *)msg);
perror("");
#endif
}
return octets_sent;
}
int rtp_recvfrom(rtp_receiver_t receiver, void *msg, int *len)
{
int octets_recvd;
srtp_err_status_t stat;
octets_recvd = recvfrom(receiver->socket, (void *)&receiver->message, *len,
0, (struct sockaddr *)NULL, 0);
if (octets_recvd == -1) {
*len = 0;
return -1;
}
/* verify rtp header */
if (receiver->message.header.version != 2) {
*len = 0;
return -1;
}
#if PRINT_DEBUG
fprintf(stderr, "%d octets received from SSRC %u\n", octets_recvd,
receiver->message.header.ssrc);
#endif
#if VERBOSE_DEBUG
srtp_print_packet(&receiver->message.header, octets_recvd);
#endif
/* apply srtp */
stat = srtp_unprotect(receiver->srtp_ctx, &receiver->message.header,
&octets_recvd);
if (stat) {
fprintf(stderr, "error: srtp unprotection failed with code %d%s\n",
stat,
stat == srtp_err_status_replay_fail
? " (replay check failed)"
: stat == srtp_err_status_auth_fail ? " (auth check failed)"
: "");
return -1;
}
strncpy(msg, receiver->message.body, octets_recvd);
return octets_recvd;
}
int rtp_sender_init(rtp_sender_t sender,
int sock,
struct sockaddr_in addr,
unsigned int ssrc)
{
/* set header values */
sender->message.header.ssrc = htonl(ssrc);
sender->message.header.ts = 0;
sender->message.header.seq = (uint16_t)srtp_cipher_rand_u32_for_tests();
sender->message.header.m = 0;
sender->message.header.pt = 0x1;
sender->message.header.version = 2;
sender->message.header.p = 0;
sender->message.header.x = 0;
sender->message.header.cc = 0;
/* set other stuff */
sender->socket = sock;
sender->addr = addr;
return 0;
}
int rtp_receiver_init(rtp_receiver_t rcvr,
int sock,
struct sockaddr_in addr,
unsigned int ssrc)
{
/* set header values */
rcvr->message.header.ssrc = htonl(ssrc);
rcvr->message.header.ts = 0;
rcvr->message.header.seq = 0;
rcvr->message.header.m = 0;
rcvr->message.header.pt = 0x1;
rcvr->message.header.version = 2;
rcvr->message.header.p = 0;
rcvr->message.header.x = 0;
rcvr->message.header.cc = 0;
/* set other stuff */
rcvr->socket = sock;
rcvr->addr = addr;
return 0;
}
int rtp_sender_init_srtp(rtp_sender_t sender, const srtp_policy_t *policy)
{
return srtp_create(&sender->srtp_ctx, policy);
}
int rtp_sender_deinit_srtp(rtp_sender_t sender)
{
return srtp_dealloc(sender->srtp_ctx);
}
int rtp_receiver_init_srtp(rtp_receiver_t sender, const srtp_policy_t *policy)
{
return srtp_create(&sender->srtp_ctx, policy);
}
int rtp_receiver_deinit_srtp(rtp_receiver_t sender)
{
return srtp_dealloc(sender->srtp_ctx);
}
rtp_sender_t rtp_sender_alloc(void)
{
return (rtp_sender_t)malloc(sizeof(rtp_sender_ctx_t));
}
void rtp_sender_dealloc(rtp_sender_t rtp_ctx)
{
free(rtp_ctx);
}
rtp_receiver_t rtp_receiver_alloc(void)
{
return (rtp_receiver_t)malloc(sizeof(rtp_receiver_ctx_t));
}
void rtp_receiver_dealloc(rtp_receiver_t rtp_ctx)
{
free(rtp_ctx);
}
|
