本文主要是介绍Linux网络编程(四) 同时处理一个端口的UDP与TCP连接,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
从bind
系统调用的参数来看,一个socket
只能与一个socket
地址绑定,即一个socket
只能用来监听一个端口。因此,服务器如果要同时监听多个端口,就必须创建多个socket,并将它们分别绑定到各个端口上。这样一来,服务器程序就需要同时管理多个监听socket,I/O复用技术就有了用武之地。
即使是同一个端口,如果服务器要同时处理该端口上的TCP和UDP请求,则也需要创建两个不同的socket:一个是流socket,另一个是数据报socket,并将它们都绑定到该端口上。
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/epoll.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>#define MAX_EVENT_NUMBER 1024
#define TCP_BUFFER_SIZE 512
#define UDP_BUFFER_SIZE 1024/* 设置文件为非阻塞 */
int setnonblocking(int fd)
{int old_option = fcntl(fd, F_GETFL);int new_option = old_option | O_NONBLOCK;fcntl(fd, F_SETFL, new_option);return old_option;
}/* 添加epoll事件,ET边缘触发模式 */
void addfd(int epollfd, int fd)
{struct epoll_event event;event.data.fd = fd;event.events = EPOLLIN | EPOLLET;epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event);setnonblocking(fd);
}int main()
{const char *ip = "127.0.0.1";int port = 8080;int ret = 0;struct sockaddr_in address;bzero(&address, sizeof(address));address.sin_family = AF_INET;inet_pton(AF_INET, ip, &address.sin_addr);address.sin_port = htons(port);/*创建TCP socket,并将其绑定到端口port上*/int tcpfd = socket(PF_INET, SOCK_STREAM, 0);ret = bind(tcpfd, (struct sockaddr *)&address, sizeof(address));assert(ret != -1);ret = listen(tcpfd, 5);assert(ret != -1);/*创建UDP socket,并将其绑定到端口port上*/bzero(&address, sizeof(address));address.sin_family = AF_INET;inet_pton(AF_INET, ip, &address.sin_addr);address.sin_port = htons(port);int udpfd = socket(PF_INET, SOCK_DGRAM, 0);ret = bind(udpfd, (struct sockaddr *)&address, sizeof(address));assert(ret != -1);/* 创建epoll事件表 */struct epoll_event events[MAX_EVENT_NUMBER];int epollfd = epoll_create(256);assert(epollfd != -1);/* 注册TCP socket和UDP socket上的可读事件 */addfd(epollfd, tcpfd);addfd(epollfd, udpfd);while (1){int number = epoll_wait(epollfd, events, MAX_EVENT_NUMBER, -1);if (number < 0){printf("epoll failure\n");break;}// 处理事件for (int i = 0; i < number; i++){int sockfd = events[i].data.fd;// 如果是tcp连接事件,那么将其注册到epoll事件表中if (sockfd == tcpfd){struct sockaddr_in client_address;socklen_t client_addrlength = sizeof(client_address);int connfd = accept(tcpfd, (struct sockaddr *)&client_address, &client_addrlength);addfd(epollfd, connfd);}// 如果是udp连接事件,那么else if (sockfd == udpfd){char buf[UDP_BUFFER_SIZE];memset(buf, '\0', UDP_BUFFER_SIZE);struct sockaddr_in client_address;socklen_t client_addrlength = sizeof(client_address);// 将udp中的数据读取到buf中ret = recvfrom(udpfd, buf, UDP_BUFFER_SIZE - 1, 0,(struct sockaddr *)&client_address, &client_addrlength);// 如果收到了数据,打印if (ret > 0){printf("%s\n",buf);}}// 如果是一个socket有数据输入else if (events[i].events & EPOLLIN){char buf[TCP_BUFFER_SIZE];while (1){memset(buf, '\0', TCP_BUFFER_SIZE);ret = recv(sockfd, buf, TCP_BUFFER_SIZE - 1, 0);if (ret < 0){ // 如果当前操作非阻塞,操作无法立即完成,那么先不做处理if ((errno == EAGAIN) || (errno == EWOULDBLOCK)) break;// 如果是出现了其他错误,那么关闭socketclose(sockfd);break;}// 如果数据已经读完else if (ret == 0){close(sockfd);}// 如果是其他情况,那么返回收到的数据else{printf("%s\n",buf);}}}else{printf("something else happened\n");}}}close(tcpfd);return 0;
}
主要的精髓在这里
int tcpfd = socket(PF_INET, SOCK_STREAM, 0);
int udpfd = socket(PF_INET, SOCK_DGRAM, 0);
看一下客户端:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h> #define SERVER_IP "127.0.0.1"
#define SERVER_PORT 8080
#define BUFFER_SIZE 1024 int main() { int tcp_socket, udp_socket; struct sockaddr_in server_addr; char buffer[BUFFER_SIZE]; ssize_t bytes_sent; // 创建TCP socket tcp_socket = socket(AF_INET, SOCK_STREAM, 0); if (tcp_socket == -1) { perror("TCP socket creation failed"); exit(EXIT_FAILURE); } // 创建UDP socket udp_socket = socket(AF_INET, SOCK_DGRAM, 0); if (udp_socket == -1) { perror("UDP socket creation failed"); exit(EXIT_FAILURE); } // 设置服务器地址信息 memset(&server_addr, 0, sizeof(server_addr)); server_addr.sin_family = AF_INET; server_addr.sin_port = htons(SERVER_PORT); if (inet_pton(AF_INET, SERVER_IP, &server_addr.sin_addr) <= 0) { perror("Invalid server address"); close(tcp_socket); close(udp_socket); exit(EXIT_FAILURE); } // 连接到TCP服务器 if (connect(tcp_socket, (struct sockaddr *) &server_addr, sizeof(server_addr)) == -1) { perror("TCP connection failed"); close(tcp_socket); close(udp_socket); exit(EXIT_FAILURE); } printf("Connected to server\n"); // 发送TCP消息给服务器 const char *tcp_message = "Hello, this is TCP message!\n";bytes_sent = send(tcp_socket, tcp_message, strlen(tcp_message), 0); if (bytes_sent == -1) {perror("TCP send failed");close(tcp_socket);close(udp_socket);exit(EXIT_FAILURE);}// 发送UDP消息给服务器 const char *udp_message = "Hello, this is UDP message!\n";bytes_sent = sendto(udp_socket, udp_message, strlen(udp_message), 0, (struct sockaddr *) &server_addr, sizeof(server_addr));if (bytes_sent == -1) {perror("UDP sendto failed");close(tcp_socket);close(udp_socket);exit(EXIT_FAILURE);}// 关闭连接close(tcp_socket);close(udp_socket);return 0;
}
仿真
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