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2ba45a60 DM |
1 | /* |
2 | * SRTP network protocol | |
3 | * Copyright (c) 2012 Martin Storsjo | |
4 | * | |
5 | * This file is part of FFmpeg. | |
6 | * | |
7 | * FFmpeg is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; either | |
10 | * version 2.1 of the License, or (at your option) any later version. | |
11 | * | |
12 | * FFmpeg is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with FFmpeg; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | #include "libavutil/opt.h" | |
23 | #include "avformat.h" | |
24 | #include "avio_internal.h" | |
25 | #include "url.h" | |
26 | ||
27 | #include "internal.h" | |
28 | #include "rtpdec.h" | |
29 | #include "srtp.h" | |
30 | ||
31 | typedef struct SRTPProtoContext { | |
32 | const AVClass *class; | |
33 | URLContext *rtp_hd; | |
34 | const char *out_suite, *out_params; | |
35 | const char *in_suite, *in_params; | |
36 | struct SRTPContext srtp_out, srtp_in; | |
37 | uint8_t encryptbuf[RTP_MAX_PACKET_LENGTH]; | |
38 | } SRTPProtoContext; | |
39 | ||
40 | #define D AV_OPT_FLAG_DECODING_PARAM | |
41 | #define E AV_OPT_FLAG_ENCODING_PARAM | |
42 | static const AVOption options[] = { | |
43 | { "srtp_out_suite", "", offsetof(SRTPProtoContext, out_suite), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E }, | |
44 | { "srtp_out_params", "", offsetof(SRTPProtoContext, out_params), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E }, | |
45 | { "srtp_in_suite", "", offsetof(SRTPProtoContext, in_suite), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E }, | |
46 | { "srtp_in_params", "", offsetof(SRTPProtoContext, in_params), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E }, | |
47 | { NULL } | |
48 | }; | |
49 | ||
50 | static const AVClass srtp_context_class = { | |
51 | .class_name = "srtp", | |
52 | .item_name = av_default_item_name, | |
53 | .option = options, | |
54 | .version = LIBAVUTIL_VERSION_INT, | |
55 | }; | |
56 | ||
57 | static int srtp_close(URLContext *h) | |
58 | { | |
59 | SRTPProtoContext *s = h->priv_data; | |
60 | ff_srtp_free(&s->srtp_out); | |
61 | ff_srtp_free(&s->srtp_in); | |
62 | ffurl_close(s->rtp_hd); | |
63 | s->rtp_hd = NULL; | |
64 | return 0; | |
65 | } | |
66 | ||
67 | static int srtp_open(URLContext *h, const char *uri, int flags) | |
68 | { | |
69 | SRTPProtoContext *s = h->priv_data; | |
70 | char hostname[256], buf[1024], path[1024]; | |
71 | int rtp_port, ret; | |
72 | ||
73 | if (s->out_suite && s->out_params) | |
74 | if ((ret = ff_srtp_set_crypto(&s->srtp_out, s->out_suite, s->out_params)) < 0) | |
75 | goto fail; | |
76 | if (s->in_suite && s->in_params) | |
77 | if ((ret = ff_srtp_set_crypto(&s->srtp_in, s->in_suite, s->in_params)) < 0) | |
78 | goto fail; | |
79 | ||
80 | av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &rtp_port, | |
81 | path, sizeof(path), uri); | |
82 | ff_url_join(buf, sizeof(buf), "rtp", NULL, hostname, rtp_port, "%s", path); | |
83 | if ((ret = ffurl_open(&s->rtp_hd, buf, flags, &h->interrupt_callback, NULL)) < 0) | |
84 | goto fail; | |
85 | ||
86 | h->max_packet_size = FFMIN(s->rtp_hd->max_packet_size, | |
87 | sizeof(s->encryptbuf)) - 14; | |
88 | h->is_streamed = 1; | |
89 | return 0; | |
90 | ||
91 | fail: | |
92 | srtp_close(h); | |
93 | return ret; | |
94 | } | |
95 | ||
96 | static int srtp_read(URLContext *h, uint8_t *buf, int size) | |
97 | { | |
98 | SRTPProtoContext *s = h->priv_data; | |
99 | int ret; | |
100 | start: | |
101 | ret = ffurl_read(s->rtp_hd, buf, size); | |
102 | if (ret > 0 && s->srtp_in.aes) { | |
103 | if (ff_srtp_decrypt(&s->srtp_in, buf, &ret) < 0) | |
104 | goto start; | |
105 | } | |
106 | return ret; | |
107 | } | |
108 | ||
109 | static int srtp_write(URLContext *h, const uint8_t *buf, int size) | |
110 | { | |
111 | SRTPProtoContext *s = h->priv_data; | |
112 | if (!s->srtp_out.aes) | |
113 | return ffurl_write(s->rtp_hd, buf, size); | |
114 | size = ff_srtp_encrypt(&s->srtp_out, buf, size, s->encryptbuf, | |
115 | sizeof(s->encryptbuf)); | |
116 | if (size < 0) | |
117 | return size; | |
118 | return ffurl_write(s->rtp_hd, s->encryptbuf, size); | |
119 | } | |
120 | ||
121 | static int srtp_get_file_handle(URLContext *h) | |
122 | { | |
123 | SRTPProtoContext *s = h->priv_data; | |
124 | return ffurl_get_file_handle(s->rtp_hd); | |
125 | } | |
126 | ||
127 | static int srtp_get_multi_file_handle(URLContext *h, int **handles, | |
128 | int *numhandles) | |
129 | { | |
130 | SRTPProtoContext *s = h->priv_data; | |
131 | return ffurl_get_multi_file_handle(s->rtp_hd, handles, numhandles); | |
132 | } | |
133 | ||
134 | URLProtocol ff_srtp_protocol = { | |
135 | .name = "srtp", | |
136 | .url_open = srtp_open, | |
137 | .url_read = srtp_read, | |
138 | .url_write = srtp_write, | |
139 | .url_close = srtp_close, | |
140 | .url_get_file_handle = srtp_get_file_handle, | |
141 | .url_get_multi_file_handle = srtp_get_multi_file_handle, | |
142 | .priv_data_size = sizeof(SRTPProtoContext), | |
143 | .priv_data_class = &srtp_context_class, | |
144 | .flags = URL_PROTOCOL_FLAG_NETWORK, | |
145 | }; |