1 /*
2 
3 Copyright (c) 2003-2018, Arvid Norberg
4 All rights reserved.
5 
6 Redistribution and use in source and binary forms, with or without
7 modification, are permitted provided that the following conditions
8 are met:
9 
10     * Redistributions of source code must retain the above copyright
11       notice, this list of conditions and the following disclaimer.
12     * Redistributions in binary form must reproduce the above copyright
13       notice, this list of conditions and the following disclaimer in
14       the documentation and/or other materials provided with the distribution.
15     * Neither the name of the author nor the names of its
16       contributors may be used to endorse or promote products derived
17       from this software without specific prior written permission.
18 
19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
23 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 POSSIBILITY OF SUCH DAMAGE.
30 
31 */
32 
33 #ifndef TORRENT_WEB_PEER_CONNECTION_HPP_INCLUDED
34 #define TORRENT_WEB_PEER_CONNECTION_HPP_INCLUDED
35 
36 #include <ctime>
37 #include <algorithm>
38 #include <vector>
39 #include <deque>
40 #include <string>
41 #include <cstdint>
42 
43 #include "libtorrent/config.hpp"
44 #include "libtorrent/web_connection_base.hpp"
45 #include "libtorrent/piece_block_progress.hpp"
46 #include "libtorrent/operations.hpp" // for operation_t enum
47 #include "libtorrent/aux_/vector.hpp"
48 
49 namespace libtorrent {
50 
51 	class TORRENT_EXTRA_EXPORT web_peer_connection
52 		: public web_connection_base
53 	{
54 	friend class invariant_access;
55 	public:
56 
57 		// this is the constructor where the we are the active part.
58 		// The peer_connection should handshake and verify that the
59 		// other end has the correct id
60 		web_peer_connection(peer_connection_args const& pack
61 			, web_seed_t& web);
62 
63 		void on_connected() override;
64 
type() const65 		connection_type type() const override
66 		{ return connection_type::url_seed; }
67 
68 		// called from the main loop when this connection has any
69 		// work to do.
70 		void on_receive(error_code const& error
71 			, std::size_t bytes_transferred) override;
72 
url() const73 		std::string const& url() const override { return m_url; }
74 
75 		void get_specific_peer_info(peer_info& p) const override;
76 		void disconnect(error_code const& ec
77 			, operation_t op, disconnect_severity_t error = peer_connection_interface::normal) override;
78 
79 		void write_request(peer_request const& r) override;
80 
81 		bool received_invalid_data(piece_index_t index, bool single_peer) override;
82 
83 	private:
84 
85 		void on_receive_padfile();
86 		void incoming_payload(char const* buf, int len);
87 		void incoming_zeroes(int len);
88 		void handle_redirect(int bytes_left);
89 		void handle_error(int bytes_left);
90 		void maybe_harvest_piece();
91 
92 		// returns the block currently being
93 		// downloaded. And the progress of that
94 		// block. If the peer isn't downloading
95 		// a piece for the moment, the boost::optional
96 		// will be invalid.
97 		piece_block_progress downloading_piece_progress() const override;
98 
99 		void handle_padfile();
100 
101 		// this has one entry per http-request
102 		// (might be more than the bt requests)
103 		struct file_request_t
104 		{
105 			file_index_t file_index;
106 			int length;
107 			std::int64_t start;
108 		};
109 		std::deque<file_request_t> m_file_requests;
110 
111 		std::string m_url;
112 
113 		web_seed_t* m_web;
114 
115 		// this is used for intermediate storage of pieces to be delivered to the
116 		// bittorrent engine
117 		// TODO: 3 if we make this be a disk_buffer_holder instead
118 		// we would save a copy
119 		// use allocate_disk_receive_buffer and release_disk_receive_buffer
120 		aux::vector<char> m_piece;
121 
122 		// the number of bytes we've forwarded to the incoming_payload() function
123 		// in the current HTTP response. used to know where in the buffer the
124 		// next response starts
125 		int m_received_body;
126 
127 		// this is the offset inside the current receive
128 		// buffer where the next chunk header will be.
129 		// this is updated for each chunk header that's
130 		// parsed. It does not necessarily point to a valid
131 		// offset in the receive buffer, if we haven't received
132 		// it yet. This offset never includes the HTTP header
133 		int m_chunk_pos;
134 
135 		// this is the number of bytes we've already received
136 		// from the next chunk header we're waiting for
137 		int m_partial_chunk_header;
138 
139 		// the number of responses we've received so far on
140 		// this connection
141 		int m_num_responses;
142 	};
143 }
144 
145 #endif // TORRENT_WEB_PEER_CONNECTION_HPP_INCLUDED
146