From 0d8a5a8a444a402c0627aa10212bfed7dea791f1 Mon Sep 17 00:00:00 2001
From: arvidn <arvid@libtorrent.org>
Date: Mon, 19 Nov 2018 01:56:30 +0100
Subject: [PATCH] add support for &ipv4= tracker argument

---
 ChangeLog                              |  1 +
 include/libtorrent/tracker_manager.hpp |  1 +
 simulation/test_tracker.cpp            | 25 ++++++++++++++++++-------
 src/http_tracker_connection.cpp        | 11 +++++++++++
 src/torrent.cpp                        | 12 +++++++-----
 5 files changed, 38 insertions(+), 12 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 33ff51dd7..b464801fe 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,6 @@
 1.2 release
 
+	* support &ipv4= tracker argument for private torrents
 	* renamed debug_notification to connect_notification
 	* when updating listen sockets, only post alerts for new ones
 	* deprecate anonymous_mode_alert
diff --git a/include/libtorrent/tracker_manager.hpp b/include/libtorrent/tracker_manager.hpp
index 0b5a0f6be..86331adbc 100644
--- a/include/libtorrent/tracker_manager.hpp
+++ b/include/libtorrent/tracker_manager.hpp
@@ -144,6 +144,7 @@ namespace libtorrent {
 		std::uint32_t key;
 		int num_want;
 		std::vector<address_v6> ipv6;
+		std::vector<address_v4> ipv4;
 		sha1_hash info_hash;
 		peer_id pid;
 
diff --git a/simulation/test_tracker.cpp b/simulation/test_tracker.cpp
index f83329bd9..9907422d5 100644
--- a/simulation/test_tracker.cpp
+++ b/simulation/test_tracker.cpp
@@ -970,11 +970,13 @@ TORRENT_TEST(tracker_ipv6_argument)
 {
 	bool got_announce = false;
 	bool got_ipv6 = false;
+	bool got_ipv4 = false;
 	tracker_test(
 		[](lt::add_torrent_params& p, lt::session& ses)
 		{
 			settings_pack pack;
 			pack.set_bool(settings_pack::anonymous_mode, false);
+			pack.set_str(settings_pack::listen_interfaces, "10.0.0.3:0,[ffff::1337]:0");
 			ses.apply_settings(pack);
 			p.ti = make_torrent(true);
 			return 60;
@@ -984,13 +986,22 @@ TORRENT_TEST(tracker_ipv6_argument)
 		{
 			got_announce = true;
 			bool const stop_event = req.find("&event=stopped") != std::string::npos;
-			// stop events don't need to advertise the IPv6 address
-			std::string::size_type pos = req.find("&ipv6=");
-			TEST_CHECK(pos != std::string::npos || stop_event);
-			got_ipv6 |= pos != std::string::npos;
-			// make sure the IPv6 argument is url encoded
-			TEST_CHECK(req.substr(pos + 6, req.substr(pos + 6).find_first_of('&'))
-				== "ffff%3a%3a1337");
+			// stop events don't need to advertise the IPv6/IPv4 address
+			{
+				std::string::size_type const pos = req.find("&ipv6=");
+				TEST_CHECK(pos != std::string::npos || stop_event);
+				got_ipv6 |= pos != std::string::npos;
+				// make sure the IPv6 argument is url encoded
+				TEST_EQUAL(req.substr(pos + 6, req.substr(pos + 6).find_first_of('&'))
+					, "ffff%3a%3a1337");
+			}
+
+			{
+				std::string::size_type const pos = req.find("&ipv4=");
+				TEST_CHECK(pos != std::string::npos || stop_event);
+				got_ipv4 |= pos != std::string::npos;
+				TEST_EQUAL(req.substr(pos + 6, req.substr(pos + 6).find_first_of('&')), "10.0.0.3");
+			}
 			return sim::send_response(200, "OK", 11) + "d5:peers0:e";
 		}
 		, [](torrent_handle) {}
diff --git a/src/http_tracker_connection.cpp b/src/http_tracker_connection.cpp
index 3f527e813..f1d1e934e 100644
--- a/src/http_tracker_connection.cpp
+++ b/src/http_tracker_connection.cpp
@@ -172,6 +172,17 @@ namespace libtorrent {
 			}
 		}
 
+		if (!tracker_req().ipv4.empty() && !i2p)
+		{
+			for (auto const& v4 : tracker_req().ipv4)
+			{
+				error_code err;
+				std::string const ip = v4.to_string(err);
+				if (err) continue;
+				url += "&ipv4=";
+				url += escape_string(ip);
+			}
+		}
 		if (!tracker_req().ipv6.empty() && !i2p)
 		{
 			for (auto const& v6 : tracker_req().ipv6)
diff --git a/src/torrent.cpp b/src/torrent.cpp
index b50df9d9c..ca216a0fc 100644
--- a/src/torrent.cpp
+++ b/src/torrent.cpp
@@ -2782,11 +2782,13 @@ bool is_downloading_state(int const st)
 		{
 			m_ses.for_each_listen_socket([&](aux::listen_socket_handle const& s)
 			{
-				if (s.is_ssl() != is_ssl_torrent())
-					return;
-				if (!is_v6(s.get_local_endpoint()))
-					return;
-				req.ipv6.push_back(s.get_local_endpoint().address().to_v6());
+				if (s.is_ssl() != is_ssl_torrent()) return;
+				tcp::endpoint const ep = s.get_local_endpoint();
+				if (is_any(ep.address())) return;
+				if (is_v6(ep))
+					req.ipv6.push_back(ep.address().to_v6());
+				else
+					req.ipv4.push_back(ep.address().to_v4());
 			});
 		}