udp_socket.cpp

#include"udp_socket.h"
#include"comm_socket.h"
UdpSocket::UdpSocket(){
}

UdpSocket::~UdpSocket(){
}
bool UdpSocket::Create(){
	socket_fd_ = socket(AF_INET, SOCK_DGRAM, 0);
	if (socket_fd_ < 0){
		perror("build udp socket failed!\n");
		return false;
	}
	return true;
}

int UdpSocket::SendTo(char* buf, int len, const char* dst_ip, uint16_t dst_port){
	struct sockaddr_in sock_addr;
	sock_addr.sin_family = AF_INET;
	sock_addr.sin_port = htons(dst_port);
	sock_addr.sin_addr.s_addr = inet_addr(dst_ip);
	int result = sendto(socket_fd_, buf, len, 0, (sockaddr*)&sock_addr, sizeof(sockaddr));
	if (result < 0){
		perror("udp send\n");
	}
	return result;
}
int UdpSocket::SendTo(char* buf, int len, const struct sockaddr_in& sock_addr){
	 int result = sendto(socket_fd_, buf, len, 0, (sockaddr*)&sock_addr, sizeof(sockaddr));
	if (result < 0){
		perror("udp send\n");
	}
	return result;
}

int UdpSocket::RecvFrom(char* buf, int buf_len, uint32_t* from_ip, uint16_t* from_port){
	struct sockaddr_in sock_addr;
#ifdef LINUX
	socklen_t addr_len = sizeof(sock_addr);
#else
	int addr_len = sizeof(sock_addr);
#endif
	int recv_bytes = recvfrom(socket_fd_, buf, buf_len, 0, (sockaddr*)&sock_addr, &addr_len);
	if (recv_bytes < 0){
		perror("udp recv\n");
	}
	if (from_ip){
		*from_ip = ntohl(sock_addr.sin_addr.s_addr);
	}
	if (from_port){
		*from_port = ntohs(sock_addr.sin_port);
	}

	return recv_bytes;
}
int UdpSocket::WaitMsg(int time_out, int *elapsed_time){
	const int MSG_IDLE = 0, MSG_ARRIVAL = 1;
	fd_set read_fds;
	FD_ZERO(&read_fds);
	FD_SET(socket_fd_, &read_fds);
	struct timeval time_val;
	time_val.tv_sec = time_out / 1000;
	time_val.tv_usec = time_out % 1000 * 1000;
	int ret = select(socket_fd_ + 1, &read_fds, NULL, NULL, &time_val);
	int result = MSG_IDLE;
	if (ret == -1){
		perror("udp select error\n");
		return result;
	}else if(ret == 0){
		//time out
		*elapsed_time = time_out;
	}else{
		if (FD_ISSET(socket_fd_, &read_fds)){
			*elapsed_time = time_out - (time_val.tv_sec * 1000 + time_val.tv_usec / 1000);
			result = MSG_ARRIVAL;
		}
	}
	return result;
}