获取socket远程和本地IP端口

IPV4：

class Net
{
public:
	static int getPeerToString(SOCKET sock, std::string &ip, unsigned short &port)
	{
		struct sockaddr_storage sa;
		int salen = sizeof(sa);
		if (::getpeername(sock, (struct sockaddr*)&sa, &salen) == -1) {
			ip = "?";
			port = 0;
			return -1;
		}

		if (sa.ss_family == AF_INET) {
			struct sockaddr_in *s = (struct sockaddr_in*)&sa;
			ip = ::inet_ntoa(s->sin_addr);
			port = ::ntohs(s->sin_port);
			return 0;
		}
		return -1;
	}

	static int getLocalToString(SOCKET sock, std::string &ip, unsigned short &port)
	{
		struct sockaddr_storage sa;
		int salen = sizeof(sa);

		if (::getsockname(sock, (struct sockaddr*)&sa, &salen) == -1) {
			ip = "?";
			port = 0;
			return -1;
		}

		if (sa.ss_family == AF_INET) {
			struct sockaddr_in *s = (struct sockaddr_in*)&sa;
			ip = ::inet_ntoa(s->sin_addr);
			port = ::ntohs(s->sin_port);
			return 0;
		}
		return -1;
	}
};