merged lt_tex fix from RC_0_16

ChangeLog

@@ -39,6 +39,7 @@
 	* fix uTP edge case where udp socket buffer fills up
 	* fix nagle implementation in uTP
 
+	* make lt_tex more robust against bugs and malicious behavior
 	* HTTP chunked encoding fix
 	* expose file_granularity flag to python bindings
 	* fix DHT memory error

include/libtorrent/escape_string.hpp

@@ -53,6 +53,8 @@ namespace libtorrent
 	// it will be encoded
 	TORRENT_EXTRA_EXPORT std::string maybe_url_encode(std::string const& url);
 
+	// returns true if the given string (not null terminated) contains
+	// characters that would need to be escaped if used in a URL
 	TORRENT_EXTRA_EXPORT bool need_encoding(char const* str, int len);
 
 	// encodes a string using the base64 scheme

include/libtorrent/parse_url.hpp

@@ -50,6 +50,7 @@ POSSIBILITY OF SUCH DAMAGE.
 namespace libtorrent
 {
 
+	// returns protocol, auth, hostname, port, path
 	TORRENT_EXTRA_EXPORT boost::tuple<std::string, std::string
 		, std::string, int, std::string>
 		parse_url_components(std::string url, error_code& ec);

include/libtorrent/torrent.hpp

@@ -741,7 +741,11 @@ namespace libtorrent
 		{ return m_trackers; }
 
 		void replace_trackers(std::vector<announce_entry> const& urls);
-		void add_tracker(announce_entry const& url);
+
+		// returns true if the tracker was added, and false if it was already
+		// in the tracker list (in which case the source was added to the
+		// entry in the list)
+		bool add_tracker(announce_entry const& url);
 
 		torrent_handle get_handle();
 

src/lt_trackers.cpp

@@ -57,6 +57,8 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/extensions.hpp"
 #include "libtorrent/extensions/ut_metadata.hpp"
 #include "libtorrent/alert_types.hpp"
+#include "libtorrent/escape_string.hpp"
+#include "libtorrent/parse_url.hpp"
 #ifdef TORRENT_STATS
 #include "libtorrent/aux_/session_impl.hpp"
 #endif
@@ -78,6 +80,7 @@ namespace libtorrent { namespace
 			: m_torrent(t)
 			, m_updates(0)
 			, m_2_minutes(110)
+			, m_num_trackers(0)
 		{
 			m_old_trackers = t.trackers();
 			update_list_hash();
@@ -133,6 +136,9 @@ namespace libtorrent { namespace
 
 		std::vector<announce_entry> const& trackers() const { return m_old_trackers; }
 
+		void increment_tracker_counter() { m_num_trackers++; }
+		int num_tex_trackers() const { return m_num_trackers; }
+
 	private:
 		torrent& m_torrent;
 		std::vector<announce_entry> m_old_trackers;
@@ -140,6 +146,7 @@ namespace libtorrent { namespace
 		int m_2_minutes;
 		std::vector<char> m_lt_trackers_msg;
 		sha1_hash m_list_hash;
+		int m_num_trackers;
 	};
 
 
@@ -203,12 +210,6 @@ namespace libtorrent { namespace
 
 			lazy_entry const* added = msg.dict_find_list("added");
 
-#ifdef TORRENT_VERBOSE_LOGGING
-			std::stringstream log_line;
-			log_line << time_now_string() << " <== LT_TEX [ "
-				"added: ";
-#endif
-
 			// invalid tex message
 			if (added == 0)
 			{
@@ -218,14 +219,66 @@ namespace libtorrent { namespace
 				return true;
 			}
 
+#ifdef TORRENT_VERBOSE_LOGGING
+			std::stringstream log_line;
+#endif
+			if (m_tp.num_tex_trackers() >= 50)
+			{
+#ifdef TORRENT_VERBOSE_LOGGING
+				log_line << time_now_string() << " <== LT_TEX [ "
+				"we already have " << m_tp.num_tex_trackers() << " trackers "
+				"from tex, don't add any more";
+				(*m_pc.m_logger) << log_line.str();
+#endif
+				return true;
+			}
+
+#ifdef TORRENT_VERBOSE_LOGGING
+			log_line << time_now_string() << " <== LT_TEX [ "
+				"added: ";
+#endif
+
 			for (int i = 0; i < added->list_size(); ++i)
 			{
 				announce_entry e(added->list_string_value_at(i));
 				if (e.url.empty()) continue;
-				e.fail_limit = 3;
+
+				// ignore urls with binary data in them
+				if (need_encoding(e.url.c_str(), e.url.size())) continue;
+
+				// ignore invalid URLs
+				error_code ec;
+				std::string protocol;
+				std::string auth;
+				std::string hostname;
+				int port;
+				std::string path;
+				boost::tie(protocol, auth, hostname, port, path)
+					= parse_url_components(e.url, ec);
+				if (ec) continue;
+
+				// ignore unknown protocols
+				if (protocol != "udp" && protocol != "http" && protocol != "https")
+					continue;
+
+				// ignore invalid ports
+				if (port == 0)
+					continue;
+
+				if (m_tp.num_tex_trackers() >= 50)
+				{
+#ifdef TORRENT_VERBOSE_LOGGING
+					log_line << "**reached-limit** ";
+#endif
+					break;
+				}
+
+				e.fail_limit = 1;
 				e.send_stats = false;
 				e.source = announce_entry::source_tex;
-				m_torrent.add_tracker(e);
+				if (m_torrent.add_tracker(e))
+					m_tp.increment_tracker_counter();
+
 #ifdef TORRENT_VERBOSE_LOGGING
 				log_line << e.url << " ";
 #endif

src/parse_url.cpp

@@ -112,6 +112,12 @@ namespace libtorrent
 		{
 			hostname.assign(start, port_pos);
 			++port_pos;
+			for (std::string::iterator i = port_pos; i < end; ++i)
+			{
+				if (is_digit(*i)) continue;
+				ec = errors::invalid_port;
+				goto exit;
+			}
 			port = std::atoi(std::string(port_pos, end).c_str());
 		}
 		else

src/storage.cpp

@@ -1221,7 +1221,10 @@ ret:
 				return -1;
 			}
 
-			if (m_allocate_files && (op.mode & file::rw_mask) != file::read_only)
+			// if the file has priority 0, don't allocate it
+			int file_index = files().file_index(*file_iter);
+			if (m_allocate_files && (op.mode & file::rw_mask) != file::read_only
+				&& (m_file_priority.size() < file_index || m_file_priority[file_index] > 0))
 			{
 				TORRENT_ASSERT(m_file_created.size() == files().num_files());
 				if (m_file_created[file_index] == false)
@@ -1420,6 +1423,12 @@ ret:
 		bool lock_files = m_settings ? settings().lock_files : false;
 		if (lock_files) mode |= file::lock_file;
 		if (!m_allocate_files) mode |= file::sparse;
+
+		// files with priority 0 should always be sparse
+		int file_index = fe - files().begin();
+		if (m_file_priority.size() > file_index && m_file_priority[file_index] == 0)
+			mode |= file::sparse;
+
 		if (m_settings && settings().no_atime_storage) mode |= file::no_atime;
 
 		return m_pool.open_file(const_cast<default_storage*>(this), m_save_path, file_index, files(), mode, ec);

src/torrent.cpp

@@ -4268,14 +4268,14 @@ namespace libtorrent
 		}
 	}
 
-	void torrent::add_tracker(announce_entry const& url)
+	bool torrent::add_tracker(announce_entry const& url)
 	{
 		std::vector<announce_entry>::iterator k = std::find_if(m_trackers.begin()
 			, m_trackers.end(), boost::bind(&announce_entry::url, _1) == url.url);
 		if (k != m_trackers.end()) 
 		{
 			k->source |= url.source;
-			return;
+			return false;
 		}
 		k = std::upper_bound(m_trackers.begin(), m_trackers.end(), url
 			, boost::bind(&announce_entry::tier, _1) < boost::bind(&announce_entry::tier, _2));
@@ -4283,6 +4283,7 @@ namespace libtorrent
 		k = m_trackers.insert(k, url);
 		if (k->source == 0) k->source = announce_entry::source_client;
 		if (!m_trackers.empty()) announce_with_tracker();
+		return true;
 	}
 
 	bool torrent::choke_peer(peer_connection& c)