1/*
2 * Copyright (c) 2012 Nicolas George
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public License
8 * as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include <string.h>
22#include "libavutil/avstring.h"
23#include "libavutil/base64.h"
24#include "url.h"
25
26typedef struct {
27    const uint8_t *data;
28    void *tofree;
29    size_t size;
30    size_t pos;
31} DataContext;
32
33static av_cold int data_open(URLContext *h, const char *uri, int flags)
34{
35    DataContext *dc = h->priv_data;
36    const char *data, *opt, *next;
37    char *ddata;
38    int ret, base64 = 0;
39    size_t in_size;
40
41    /* data:content/type[;base64],payload */
42
43    av_strstart(uri, "data:", &uri);
44    data = strchr(uri, ',');
45    if (!data) {
46        av_log(h, AV_LOG_ERROR, "No ',' delimiter in URI\n");
47        return AVERROR(EINVAL);
48    }
49    opt = uri;
50    while (opt < data) {
51        next = av_x_if_null(memchr(opt, ';', data - opt), data);
52        if (opt == uri) {
53            if (!memchr(opt, '/', next - opt)) { /* basic validity check */
54                av_log(h, AV_LOG_ERROR, "Invalid content-type '%.*s'\n",
55                       (int)(next - opt), opt);
56                return AVERROR(EINVAL);
57            }
58            av_log(h, AV_LOG_VERBOSE, "Content-type: %.*s\n",
59                   (int)(next - opt), opt);
60        } else {
61            if (!av_strncasecmp(opt, "base64", next - opt)) {
62                base64 = 1;
63            } else {
64                av_log(h, AV_LOG_VERBOSE, "Ignoring option '%.*s'\n",
65                       (int)(next - opt), opt);
66            }
67        }
68        opt = next + 1;
69    }
70
71    data++;
72    in_size = strlen(data);
73    if (base64) {
74        size_t out_size = 3 * (in_size / 4) + 1;
75
76        if (out_size > INT_MAX || !(ddata = av_malloc(out_size)))
77            return AVERROR(ENOMEM);
78        if ((ret = av_base64_decode(ddata, data, out_size)) < 0) {
79            av_free(ddata);
80            av_log(h, AV_LOG_ERROR, "Invalid base64 in URI\n");
81            return ret;
82        }
83        dc->data = dc->tofree = ddata;
84        dc->size = ret;
85    } else {
86        dc->data = data;
87        dc->size = in_size;
88    }
89    return 0;
90}
91
92static av_cold int data_close(URLContext *h)
93{
94    DataContext *dc = h->priv_data;
95
96    av_freep(&dc->tofree);
97    return 0;
98}
99
100static int data_read(URLContext *h, unsigned char *buf, int size)
101{
102    DataContext *dc = h->priv_data;
103
104    if (dc->pos >= dc->size)
105        return AVERROR_EOF;
106    size = FFMIN(size, dc->size - dc->pos);
107    memcpy(buf, dc->data + dc->pos, size);
108    dc->pos += size;
109    return size;
110}
111
112URLProtocol ff_data_protocol = {
113    .name           = "data",
114    .url_open       = data_open,
115    .url_close      = data_close,
116    .url_read       = data_read,
117    .priv_data_size = sizeof(DataContext),
118};
119