Codechange: allow Connect() to bind to a local address

2 files changed, 16 insertions, 4 deletions

diff --git a/src/network/core/tcp.h b/src/network/core/tcp.h
index bbd0bc2a9..b4b4398de 100644
--- a/src/network/core/tcp.h
+++ b/src/network/core/tcp.h
@@ -98,6 +98,7 @@ private:
 	std::chrono::steady_clock::time_point last_attempt; ///< Time we last tried to connect.
 
 	std::string connection_string;                      ///< Current address we are connecting to (before resolving).
+	NetworkAddress bind_address;                        ///< Address we're binding to, if any.
 
 	void Resolve();
 	void OnResolved(addrinfo *ai);
@@ -113,7 +114,7 @@ private:
 
 public:
 	TCPConnecter() {};
-	TCPConnecter(const std::string &connection_string, uint16 default_port);
+	TCPConnecter(const std::string &connection_string, uint16 default_port, NetworkAddress bind_address = {});
 	virtual ~TCPConnecter();
 
 	/**
diff --git a/src/network/core/tcp_connect.cpp b/src/network/core/tcp_connect.cpp
index 0e8e2e125..6db2500f3 100644
--- a/src/network/core/tcp_connect.cpp
+++ b/src/network/core/tcp_connect.cpp
@@ -24,10 +24,13 @@
 static std::vector<TCPConnecter *> _tcp_connecters;
 
 /**
- * Create a new connecter for the given address
- * @param connection_string the address to connect to
+ * Create a new connecter for the given address.
+ * @param connection_string The address to connect to.
+ * @param default_port If not indicated in connection_string, what port to use.
+ * @param bind_address The local bind address to use. Defaults to letting the OS find one.
  */
-TCPConnecter::TCPConnecter(const std::string &connection_string, uint16 default_port)
+TCPConnecter::TCPConnecter(const std::string &connection_string, uint16 default_port, NetworkAddress bind_address) :
+	bind_address(bind_address)
 {
 	this->connection_string = NormalizeConnectionString(connection_string, default_port);
 
@@ -96,6 +99,14 @@ void TCPConnecter::Connect(addrinfo *address)
 		return;
 	}
 
+	if (this->bind_address.GetPort() > 0) {
+		if (bind(sock, (const sockaddr *)this->bind_address.GetAddress(), this->bind_address.GetAddressLength()) != 0) {
+			Debug(net, 1, "Could not bind socket on {}: {}", this->bind_address.GetAddressAsString(), NetworkError::GetLast().AsString());
+			closesocket(sock);
+			return;
+		}
+	}
+
 	if (!SetNoDelay(sock)) {
 		Debug(net, 1, "Setting TCP_NODELAY failed: {}", NetworkError::GetLast().AsString());
 	}