TCP_INFO usage on Windows

socket.cpp

#define WIN32_LEAN_AND_MEAN

#define _CRT_SECURE_NO_WARNINGS
#define _WINSOCK_DEPRECATED_NO_WARNINGS

#include <windows.h>
#include <winsock2.h>
#include <mstcpip.h>

#include <iostream>

#pragma comment(lib, "ws2_32.lib")

int main(int argc, char** argv) {

	WSADATA wsaData;
	int rc = WSAStartup(MAKEWORD(2, 2), &wsaData);

	auto sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (sockfd == INVALID_SOCKET)
	{
		rc = WSAGetLastError();
		std::cout << "Failed to create socket with error: " << rc << std::endl;
		return rc;
	}

	struct sockaddr_in server;
	server.sin_addr.s_addr = inet_addr("1.1.1.1");
	server.sin_family = AF_INET;
	server.sin_port = htons(80);

	//Connect to remote server
	rc = connect(sockfd, (struct sockaddr*)&server, sizeof(server));
	if (rc == SOCKET_ERROR)
	{
		rc = WSAGetLastError();
		std::cout << "Failed to connect socket with error: " << rc << std::endl;
		WSACleanup();
		return rc;
	}

	TCP_INFO_v0 tcpinfo;
	DWORD infoVersion = 0;
	DWORD bytesReturned = 0;
	rc = ::WSAIoctl(sockfd, SIO_TCP_INFO, &infoVersion, sizeof(infoVersion), &tcpinfo, sizeof(tcpinfo), &bytesReturned, nullptr, nullptr);
	if (rc == SOCKET_ERROR) {
		rc = WSAGetLastError();
		std::cout << "Failed to query for TCP_INFO with error: " << rc << std::endl;
		WSACleanup();
		return rc;
	}

	rc = closesocket(sockfd);
	if (rc == SOCKET_ERROR) {
		rc = WSAGetLastError();
		std::cout << "Failed to close socket with error: " << rc << std::endl;
		WSACleanup();
		return rc;
	}

	return 1;
}