lavf: make avio_read_partial() public
[libav.git] / libavformat / srtpproto.c
1 /*
2 * SRTP network protocol
3 * Copyright (c) 2012 Martin Storsjo
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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, D },
46 { "srtp_in_params", "", offsetof(SRTPProtoContext, in_params), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D },
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,
84 h->protocols, h)) < 0)
85 goto fail;
86
87 h->max_packet_size = FFMIN(s->rtp_hd->max_packet_size,
88 sizeof(s->encryptbuf)) - 14;
89 h->is_streamed = 1;
90 return 0;
91
92 fail:
93 srtp_close(h);
94 return ret;
95 }
96
97 static int srtp_read(URLContext *h, uint8_t *buf, int size)
98 {
99 SRTPProtoContext *s = h->priv_data;
100 int ret;
101 start:
102 ret = ffurl_read(s->rtp_hd, buf, size);
103 if (ret > 0 && s->srtp_in.aes) {
104 if (ff_srtp_decrypt(&s->srtp_in, buf, &ret) < 0)
105 goto start;
106 }
107 return ret;
108 }
109
110 static int srtp_write(URLContext *h, const uint8_t *buf, int size)
111 {
112 SRTPProtoContext *s = h->priv_data;
113 if (!s->srtp_out.aes)
114 return ffurl_write(s->rtp_hd, buf, size);
115 size = ff_srtp_encrypt(&s->srtp_out, buf, size, s->encryptbuf,
116 sizeof(s->encryptbuf));
117 if (size < 0)
118 return size;
119 return ffurl_write(s->rtp_hd, s->encryptbuf, size);
120 }
121
122 static int srtp_get_file_handle(URLContext *h)
123 {
124 SRTPProtoContext *s = h->priv_data;
125 return ffurl_get_file_handle(s->rtp_hd);
126 }
127
128 static int srtp_get_multi_file_handle(URLContext *h, int **handles,
129 int *numhandles)
130 {
131 SRTPProtoContext *s = h->priv_data;
132 return ffurl_get_multi_file_handle(s->rtp_hd, handles, numhandles);
133 }
134
135 const URLProtocol ff_srtp_protocol = {
136 .name = "srtp",
137 .url_open = srtp_open,
138 .url_read = srtp_read,
139 .url_write = srtp_write,
140 .url_close = srtp_close,
141 .url_get_file_handle = srtp_get_file_handle,
142 .url_get_multi_file_handle = srtp_get_multi_file_handle,
143 .priv_data_size = sizeof(SRTPProtoContext),
144 .priv_data_class = &srtp_context_class,
145 .flags = URL_PROTOCOL_FLAG_NETWORK,
146 };