DNS name resolution for command line parameters

src/json_rpc_request.cpp

@@ -39,8 +39,13 @@ JSONRPCRequest::JSONRPCRequest(const char* address, int port, const char* req, C
 	uv_tcp_init(uv_default_loop_checked(), &m_socket);
 	uv_tcp_nodelay(&m_socket, 1);
 
-	sockaddr_in dest;
+	sockaddr_storage addr;
-	uv_ip4_addr(address, port, &dest);
+	if (uv_ip4_addr(address, port, reinterpret_cast<sockaddr_in*>(&addr)) != 0) {
+		const int err = uv_ip6_addr(address, port, reinterpret_cast<sockaddr_in6*>(&addr));
+		if (err) {
+			LOGERR(1, "invalid IP address " << address << " or port " << port);
+		}
+	}
 
 	m_socket.data = this;
 	m_connect.data = this;
@@ -59,7 +64,10 @@ JSONRPCRequest::JSONRPCRequest(const char* address, int port, const char* req, C
 
 	m_response.reserve(sizeof(m_readBuf));
 
-	uv_tcp_connect(&m_connect, &m_socket, reinterpret_cast<const sockaddr*>(&dest), on_connect);
+	const int err = uv_tcp_connect(&m_connect, &m_socket, reinterpret_cast<const sockaddr*>(&addr), on_connect);
+	if (err) {
+		LOGERR(1, "failed to initiate tcp connection to " << address << ", error " << uv_err_name(err));
+	}
 }
 
 void JSONRPCRequest::on_connect(uv_connect_t* req, int status)

src/p2p_server.cpp

@@ -135,9 +135,11 @@ void P2PServer::store_in_cache(const PoolBlock& block)
 void P2PServer::connect_to_peers(const std::string& peer_list)
 {
 	parse_address_list(peer_list,
-		[this](bool is_v6, const std::string& /*address*/, const std::string& ip, int port)
+		[this](bool is_v6, const std::string& /*address*/, std::string ip, int port)
 		{
+			if (resolve_host(ip, is_v6)) {
 				connect_to_peer(is_v6, ip.c_str(), port);
+			}
 		});
 }
 
@@ -313,10 +315,9 @@ void P2PServer::save_peer_list()
 
 void P2PServer::load_peer_list()
 {
-	// First take peers from the command line
+	std::string saved_list;
-	std::string saved_list = m_pool->params().m_p2pPeerList;
 
-	// Then load peers from seed nodes if we're on the default sidechain
+	// Load peers from seed nodes if we're on the default sidechain
 	if (m_pool->side_chain().is_default()) {
 		for (size_t i = 0; i < array_size(seed_nodes); ++i) {
 			LOGINFO(4, "loading peers from " << seed_nodes[i]);

src/p2pool.cpp

@@ -55,6 +55,12 @@ p2pool::p2pool(int argc, char* argv[])
 		panic();
 	}
 
+	bool is_v6;
+	if (!resolve_host(m_params->m_host, is_v6)) {
+		LOGERR(1, "resolve_host failed for " << m_params->m_host);
+		panic();
+	}
+
 	hash pub, sec, eph_public_key;
 	generate_keys(pub, sec);
 
@@ -384,7 +390,7 @@ void p2pool::submit_block() const
 	const uint32_t nonce = submit_data.nonce;
 	const uint32_t extra_nonce = submit_data.extra_nonce;
 
-	JSONRPCRequest::call(m_params->m_host, m_params->m_rpcPort, request.c_str(),
+	JSONRPCRequest::call(m_params->m_host.c_str(), m_params->m_rpcPort, request.c_str(),
 		[height, diff, template_id, nonce, extra_nonce](const char* data, size_t size)
 		{
 			rapidjson::Document doc;
@@ -465,7 +471,7 @@ void p2pool::download_block_headers(uint64_t current_height)
 		s.m_pos = 0;
 		s << "{\"jsonrpc\":\"2.0\",\"id\":\"0\",\"method\":\"get_block_header_by_height\",\"params\":{\"height\":" << height << "}}\0";
 
-		JSONRPCRequest::call(m_params->m_host, m_params->m_rpcPort, buf,
+		JSONRPCRequest::call(m_params->m_host.c_str(), m_params->m_rpcPort, buf,
 			[this, prev_seed_height, height](const char* data, size_t size)
 			{
 				ChainMain block;
@@ -485,7 +491,7 @@ void p2pool::download_block_headers(uint64_t current_height)
 	s.m_pos = 0;
 	s << "{\"jsonrpc\":\"2.0\",\"id\":\"0\",\"method\":\"get_block_headers_range\",\"params\":{\"start_height\":" << current_height - BLOCK_HEADERS_REQUIRED << ",\"end_height\":" << current_height - 1 << "}}\0";
 
-	JSONRPCRequest::call(m_params->m_host, m_params->m_rpcPort, buf,
+	JSONRPCRequest::call(m_params->m_host.c_str(), m_params->m_rpcPort, buf,
 		[this, current_height](const char* data, size_t size)
 		{
 			if (parse_block_headers_range(data, size) == BLOCK_HEADERS_REQUIRED) {
@@ -572,7 +578,7 @@ void p2pool::stratum_on_block()
 
 void p2pool::get_info()
 {
-	JSONRPCRequest::call(m_params->m_host, m_params->m_rpcPort, "{\"jsonrpc\":\"2.0\",\"id\":\"0\",\"method\":\"get_info\"}",
+	JSONRPCRequest::call(m_params->m_host.c_str(), m_params->m_rpcPort, "{\"jsonrpc\":\"2.0\",\"id\":\"0\",\"method\":\"get_info\"}",
 		[this](const char* data, size_t size)
 		{
 			parse_get_info_rpc(data, size);
@@ -658,7 +664,7 @@ void p2pool::parse_get_info_rpc(const char* data, size_t size)
 
 void p2pool::get_miner_data()
 {
-	JSONRPCRequest::call(m_params->m_host, m_params->m_rpcPort, "{\"jsonrpc\":\"2.0\",\"id\":\"0\",\"method\":\"get_miner_data\"}",
+	JSONRPCRequest::call(m_params->m_host.c_str(), m_params->m_rpcPort, "{\"jsonrpc\":\"2.0\",\"id\":\"0\",\"method\":\"get_miner_data\"}",
 		[this](const char* data, size_t size)
 		{
 			parse_get_miner_data_rpc(data, size);
@@ -1076,7 +1082,7 @@ int p2pool::run()
 	}
 
 	try {
-		ZMQReader z(m_params->m_host, m_params->m_zmqPort, this);
+		ZMQReader z(m_params->m_host.c_str(), m_params->m_zmqPort, this);
 		get_info();
 		const int rc = uv_run(uv_default_loop_checked(), UV_RUN_DEFAULT);
 		LOGINFO(1, "uv_run exited, result = " << rc);

src/params.cpp

@@ -72,7 +72,7 @@ Params::Params(int argc, char* argv[])
 
 bool Params::ok() const
 {
-	return m_host && m_rpcPort && m_zmqPort && m_wallet.valid();
+	return !m_host.empty() && m_rpcPort && m_zmqPort && m_wallet.valid();
 }
 
 } // namespace p2pool

src/params.h

@@ -27,7 +27,7 @@ struct Params
 
 	bool ok() const;
 
-	const char* m_host = "127.0.0.1";
+	std::string m_host = "127.0.0.1";
 	uint32_t m_rpcPort = 18081;
 	uint32_t m_zmqPort = 18083;
 	bool m_lightMode = false;

src/util.cpp

@@ -325,4 +325,42 @@ void BackgroundJobTracker::print_status()
 BackgroundJobTracker bkg_jobs_tracker;
 thread_local bool is_main_thread = false;
 
+bool resolve_host(std::string& host, bool& is_v6)
+{
+	addrinfo hints{};
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_V4MAPPED | AI_ADDRCONFIG;
+
+	addrinfo* r = nullptr;
+	const int err = getaddrinfo(host.c_str(), nullptr, &hints, &r);
+	if ((err == 0) && r) {
+		const char* addr_str = nullptr;
+		char addr_str_buf[64];
+
+		void* addr;
+		if (r->ai_family == AF_INET6) {
+			addr = &reinterpret_cast<sockaddr_in6*>(r->ai_addr)->sin6_addr;
+			is_v6 = true;
+		}
+		else {
+			addr = &reinterpret_cast<sockaddr_in*>(r->ai_addr)->sin_addr;
+			is_v6 = false;
+		}
+
+		addr_str = inet_ntop(r->ai_family, addr, addr_str_buf, sizeof(addr_str_buf));
+		if (addr_str) {
+			LOGINFO(5, log::LightCyan() << host << log::NoColor() << " resolved to " << log::Gray() << addr_str);
+			host = addr_str;
+		}
+		freeaddrinfo(r);
+	}
+	else {
+		LOGWARN(4, "getaddrinfo failed for " << host << ": " << gai_strerror(err));
+		return false;
+	}
+
+	return true;
+}
+
 } // namespace p2pool

src/util.h

@@ -117,6 +117,8 @@ private:
 extern BackgroundJobTracker bkg_jobs_tracker;
 extern thread_local bool is_main_thread;
 
+bool resolve_host(std::string& host, bool& is_v6);
+
 } // namespace p2pool
 
 template<>