socket/socket_impl/udpsocket.cpp

#include <arpa/inet.h>
#include <iostream>
#include <stdexcept>
#include <netdb.h>  //printf
#include <stdlib.h> //exit(0);
#include <cstring> //memset
#include <sys/socket.h>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <vector>

#define SERVER "127.0.0.1"
#define BUFLEN 1024 // Max length of buffer
#define PORT 8888   // The port on which to send data
class udpsocket {
	struct sockaddr_in addr;
	int s, slen = sizeof(addr);
	public:
	udpsocket(int port);
	udpsocket(const udpsocket&) = delete;
	udpsocket& operator=(const udpsocket&) = delete;
	udpsocket(udpsocket&&);
	udpsocket& operator=(udpsocket&&);
	void write(const std::string&,const std::string& dest, int port);
	void write(const std::vector<char>&,const std::string& dest, int port);
	std::vector<char> receive();
	void close();
};
udpsocket::udpsocket(int port) {
	if ((s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
		throw std::logic_error(std::string("Socket creation failed: ") + strerror(errno));
	}
	std::memset((char*)&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	addr.sin_port = htons(port);

	if (bind(s, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
		throw std::logic_error(std::string("Socket binding failed: ") + strerror(errno));
	}
}
udpsocket::udpsocket(udpsocket&& o) : addr(o.addr),s(o.s) {
	o.s = 0;
}
udpsocket& udpsocket::operator=(udpsocket&& o){
	addr = o.addr;
	s = o.s;
	o.s = 0;
	return *this;
}
void udpsocket::write(const std::string& msg, const std::string& dest, int port){
	std::vector<char> _msg(msg.begin(), msg.end());
	write(_msg, dest, port);
}
void udpsocket::write(const std::vector<char>& msg, const std::string& dest, int port){
	hostent *server_host;
	errno = 0;
	server_host = gethostbyname(dest.c_str());
	if(errno){
		throw std::logic_error("Could not resolve hostname " + dest + ": " + strerror(errno));
	}
	/* configure the server address */
	struct sockaddr_in server_addr;
	server_addr.sin_family = AF_INET; // IPv4
	memcpy(&server_addr.sin_addr, server_host->h_addr,
			sizeof(struct in_addr)); server_addr.sin_port = htons(port);
	/* send a message */
	if(sendto(s, msg.data(), msg.size(), 0,(const sockaddr*)&server_addr, sizeof(server_addr)) < 0){
		throw std::logic_error(std::string("Could not send packet: ") + strerror(errno));
	}
}
std::vector<char> udpsocket::receive(){
	std::vector<char> ret(1024);
	if (read(s, ret.data(), 1024) <= 0) {
		throw std::logic_error(std::string("Could not receive packet: ") + strerror(errno));
	}
	return ret;
}
void udpsocket::close(){
	shutdown(s, 2);
}
void die(const std::string& s) {
	perror(s.c_str());
	exit(1);
}

int main() {
	udpsocket sock(5566);
	std::vector<char> d(23,'a');
	while(true)
	sock.write(d.data(), "127.0.0.1" ,5555);
	std::cin.get();
	return 0;
}