From cc792d86381a77b435a3f6ff4f28a27d95d55411 Mon Sep 17 00:00:00 2001
From: arvidn <arvid@libtorrent.org>
Date: Wed, 26 Feb 2020 09:04:37 +0100
Subject: [PATCH] improve error messages and error reporting of failing
 enum_routes()

---
 include/libtorrent/operations.hpp |  3 +++
 src/alert.cpp                     |  4 +++-
 src/session_impl.cpp              | 31 ++++++++++++++++++++++---------
 src/string_util.cpp               |  6 +++---
 test/enum_if.cpp                  |  4 ++--
 test/test_session_params.cpp      |  6 ++++--
 6 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/include/libtorrent/operations.hpp b/include/libtorrent/operations.hpp
index 4847184e1..10a1644db 100644
--- a/include/libtorrent/operations.hpp
+++ b/include/libtorrent/operations.hpp
@@ -172,6 +172,9 @@ namespace libtorrent {
 
 		// set socket option
 		sock_option,
+
+		// enumeration network routes
+		enum_route,
 	};
 
 	// maps an operation id (from peer_error_alert and peer_disconnected_alert)
diff --git a/src/alert.cpp b/src/alert.cpp
index d5cd080b1..bc4d42eb5 100644
--- a/src/alert.cpp
+++ b/src/alert.cpp
@@ -897,6 +897,7 @@ namespace {
 			case o::symlink: return -1;
 			case o::handshake: return -1;
 			case o::sock_option: return -1;
+			case o::enum_route: return -1;
 		}
 		return -1;
 	}
@@ -1564,7 +1565,8 @@ namespace {
 			"hostname_lookup",
 			"symlink",
 			"handshake",
-			"sock_option"
+			"sock_option",
+			"enum_route"
 		};
 
 		int const idx = static_cast<int>(op);
diff --git a/src/session_impl.cpp b/src/session_impl.cpp
index 077b2e687..4340e7435 100644
--- a/src/session_impl.cpp
+++ b/src/session_impl.cpp
@@ -1359,8 +1359,12 @@ namespace aux {
 #ifndef TORRENT_DISABLE_LOGGING
 		if (should_log())
 		{
-			session_log("attempting to open listen socket to: %s on device: %s ssl: %x"
-				, print_endpoint(bind_ep).c_str(), lep.device.c_str(), static_cast<int>(lep.ssl));
+			session_log("attempting to open listen socket to: %s on device: %s %s%s%s%s"
+				, print_endpoint(bind_ep).c_str(), lep.device.c_str()
+				, (lep.ssl == transport::ssl) ? "ssl " : ""
+				, (lep.flags & listen_socket_t::has_gateway) ? "has-gateway " : ""
+				, (lep.flags & listen_socket_t::accept_incoming) ? "accept-incoming " : "no-incoming "
+				, (lep.flags & listen_socket_t::was_expanded) ? "expanded-ip " : "");
 		}
 #endif
 
@@ -1806,6 +1810,20 @@ namespace aux {
 			? listen_socket_flags_t{}
 			: listen_socket_t::accept_incoming;
 
+		std::vector<ip_interface> const ifs = enum_net_interfaces(m_io_service, ec);
+		if (ec && m_alerts.should_post<listen_failed_alert>())
+		{
+			m_alerts.emplace_alert<listen_failed_alert>(""
+				, operation_t::enum_if, ec, socket_type_t::tcp);
+		}
+		auto const routes = enum_routes(m_io_service, ec);
+		if (ec && m_alerts.should_post<listen_failed_alert>())
+		{
+			m_alerts.emplace_alert<listen_failed_alert>(""
+				, operation_t::enum_route, ec, socket_type_t::tcp);
+		}
+
+		// expand device names and populate eps
 		for (auto const& iface : m_listen_interfaces)
 		{
 			std::string const& device = iface.device;
@@ -1847,13 +1865,8 @@ namespace aux {
 				, listen_socket_flags_t{});
 		}
 
-		std::vector<ip_interface> const ifs = enum_net_interfaces(m_io_service, ec);
-		if (!ec)
-		{
-			expand_unspecified_address(ifs, eps);
-			auto const routes = enum_routes(m_io_service, ec);
-			if (!ec) expand_devices(ifs, routes, eps);
-		}
+		expand_unspecified_address(ifs, eps);
+		expand_devices(ifs, routes, eps);
 
 		auto remove_iter = partition_listen_sockets(eps, m_listen_sockets);
 
diff --git a/src/string_util.cpp b/src/string_util.cpp
index f2b750940..215459fbd 100644
--- a/src/string_util.cpp
+++ b/src/string_util.cpp
@@ -278,9 +278,9 @@ namespace libtorrent {
 		return out;
 	}
 
-	// this parses the string that's used as the listen_interfaces setting.
-	// it is a comma-separated list of IP or device names with ports. For
-	// example: "eth0:6881,eth1:6881" or "127.0.0.1:6881"
+	// this parses the string that's used as the dht_bootstrap setting.
+	// it is a comma-separated list of IP or hostnames with ports. For
+	// example: "router.bittorrent.com:6881,router.utorrent.com:6881" or "127.0.0.1:6881"
 	void parse_comma_separated_string_port(std::string const& in
 		, std::vector<std::pair<std::string, int>>& out)
 	{
diff --git a/test/enum_if.cpp b/test/enum_if.cpp
index 481343045..00e407253 100644
--- a/test/enum_if.cpp
+++ b/test/enum_if.cpp
@@ -46,7 +46,7 @@ int main()
 	auto const routes = enum_routes(ios, ec);
 	if (ec)
 	{
-		std::printf("%s\n", ec.message().c_str());
+		std::printf("enum_routes: %s\n", ec.message().c_str());
 		return 1;
 	}
 
@@ -68,7 +68,7 @@ int main()
 	auto const net = enum_net_interfaces(ios, ec);
 	if (ec)
 	{
-		std::printf("%s\n", ec.message().c_str());
+		std::printf("enum_ifs: %s\n", ec.message().c_str());
 		return 1;
 	}
 
diff --git a/test/test_session_params.cpp b/test/test_session_params.cpp
index 986560a1b..5ce83e1cb 100644
--- a/test/test_session_params.cpp
+++ b/test/test_session_params.cpp
@@ -142,8 +142,10 @@ TORRENT_TEST(dht_state)
 
 	TEST_EQUAL(params1.dht_state.nids.size(), 1);
 
-	// not a chance the nid will be the fake initial ones
-	TEST_CHECK(params1.dht_state.nids[0].second != s.nids[0].second);
+	if (params1.dht_state.nids.size() >= 1) {
+		// not a chance the nid will be the fake initial ones
+		TEST_CHECK(params1.dht_state.nids[0].second != s.nids[0].second);
+	}
 }
 #endif