1 /*
2  * Copyright 2003-2021 The Music Player Daemon Project
3  * http://www.musicpd.org
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License along
16  * with this program; if not, write to the Free Software Foundation, Inc.,
17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18  */
19 
20 #include "IcyMetaDataServer.hxx"
21 #include "tag/Tag.hxx"
22 #include "util/FormatString.hxx"
23 #include "util/AllocatedString.hxx"
24 #include "util/TruncateString.hxx"
25 
26 #include <iterator>
27 
28 #include <string.h>
29 
30 AllocatedString
icy_server_metadata_header(const char * name,const char * genre,const char * url,const char * content_type,int metaint)31 icy_server_metadata_header(const char *name,
32 			   const char *genre, const char *url,
33 			   const char *content_type, int metaint) noexcept
34 {
35 	return FormatString("HTTP/1.1 200 OK\r\n"
36 			    "icy-notice1:<BR>This stream requires an audio player!<BR>\r\n" /* TODO */
37 			    "icy-notice2:MPD - The music player daemon<BR>\r\n"
38 			    "icy-name: %s\r\n"             /* TODO */
39 			    "icy-genre: %s\r\n"            /* TODO */
40 			    "icy-url: %s\r\n"              /* TODO */
41 			    "icy-pub:1\r\n"
42 			    "icy-metaint:%d\r\n"
43 			    /* TODO "icy-br:%d\r\n" */
44 			    "Content-Type: %s\r\n"
45 			    "Connection: close\r\n"
46 			    "Pragma: no-cache\r\n"
47 			    "Cache-Control: no-cache, no-store\r\n"
48 			    "Access-Control-Allow-Origin: *\r\n"
49 			    "\r\n",
50 			    name,
51 			    genre,
52 			    url,
53 			    metaint,
54 			    /* bitrate, */
55 			    content_type);
56 }
57 
58 static AllocatedString
icy_server_metadata_string(const char * stream_title,const char * stream_url)59 icy_server_metadata_string(const char *stream_title,
60 			   const char* stream_url) noexcept
61 {
62 	// The leading n is a placeholder for the length information
63 	auto icy_metadata = FormatString("nStreamTitle='%s';"
64 					 "StreamUrl='%s';"
65 					 /* pad 15 spaces just in case
66 					    the length needs to be
67 					    rounded up */
68 					 "               ",
69 					 stream_title,
70 					 stream_url);
71 
72 	size_t meta_length = strlen(icy_metadata.c_str());
73 
74 	meta_length--; // subtract placeholder
75 
76 	meta_length = meta_length / 16;
77 
78 	icy_metadata[0] = meta_length;
79 
80 	if (meta_length > 255)
81 		return nullptr;
82 
83 	return icy_metadata;
84 }
85 
86 PagePtr
icy_server_metadata_page(const Tag & tag,const TagType * types)87 icy_server_metadata_page(const Tag &tag, const TagType *types) noexcept
88 {
89 	const char *tag_items[TAG_NUM_OF_ITEM_TYPES];
90 
91 	int last_item = -1;
92 	while (*types != TAG_NUM_OF_ITEM_TYPES) {
93 		const char *tag_item = tag.GetValue(*types++);
94 		if (tag_item)
95 			tag_items[++last_item] = tag_item;
96 	}
97 
98 	int item = 0;
99 
100 	// Length + Metadata - "StreamTitle='';StreamUrl='';" = 4081 - 28
101 	char stream_title[(1 + 255 - 28) * 16];
102 	char *p = stream_title, *const end = stream_title + std::size(stream_title);
103 	stream_title[0] =  '\0';
104 
105 	while (p < end && item <= last_item) {
106 		p = CopyTruncateString(p, tag_items[item++], end - p);
107 
108 		if (item <= last_item)
109 			p = CopyTruncateString(p, " - ", end - p);
110 	}
111 
112 	const auto icy_string = icy_server_metadata_string(stream_title, "");
113 
114 	if (icy_string == nullptr)
115 		return nullptr;
116 
117 	return std::make_shared<Page>(ConstBuffer<std::byte>{(const std::byte *)icy_string.c_str(), uint8_t(icy_string[0]) * 16U + 1U});
118 }
119