I/O复用的高级应用三:同时处理TCP和UDP服务
代码#
#include <sys/types.h>
#include <sys/socket.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>
#include <sys/epoll.h>
#include <pthread.h>
#define MAX_EVENT_NUMBER 1024
#define TCP_BUFFER_SIZE 512
#define UDP_BUFFER_SIZE 1024
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;
}
void addfd(int epollfd, int fd)
{
epoll_event event;
event.data.fd = fd;
event.events = EPOLLIN | EPOLLET;
epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event);
setnonblocking(fd);
}
int main(int argc, char* argv[])
{
if( argc <= 2 )
{
printf("Usage: %s ip_address port_number\n", basename(argv[0]));
return 1;
}
const char* ip = argv[1];
int port = atoi(argv[2]);
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 listenfd = socket(PF_INET, SOCK_STREAM, 0);
assert(listenfd >= 0);
ret = bind(listenfd, (struct sockaddr*)&address, sizeof(address));
assert(ret != -1);
ret = listen(listenfd, 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);
assert(udpfd >= 0);
ret = bind(udpfd, (struct sockaddr*)&address, sizeof(address));
assert(ret != -1);
epoll_event events[MAX_EVENT_NUMBER];
int epollfd = epoll_create(5);
assert(epollfd != -1);
/* 注册TCP socket和UDP socket上的可读事件 */
addfd(epollfd, listenfd);
addfd(epollfd, udpfd);
while(1)
{
int number = epoll_wait(epollfd, events, MAX_EVENT_NUMBER, -1);
if(number < 0)
{
printf("epoll failure\n");
break;
}
for(int i = 0; i < number; i++)
{
int sockfd = events[i].data.fd;
if(sockfd == listenfd)
{
struct sockaddr_in client_address;
socklen_t client_addrlength = sizeof(client_address);
int connfd = accept(listenfd, (struct sockaddr*)&client_address, &client_addrlength);
addfd(epollfd, connfd);
}
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);
ret = recvfrom(udpfd, buf, UDP_BUFFER_SIZE-1, 0, (struct sockaddr*)&client_address, &client_addrlength);
if(ret > 0)
{
const char *flag = "UDP data:";
sendto(udpfd, flag, 9, 0, (struct sockaddr*)&client_address, client_addrlength);
sendto(udpfd, buf, UDP_BUFFER_SIZE-1, 0, (struct sockaddr*)&client_address, client_addrlength);
}
}
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)
{
/* 如果读操作出错,则关闭连接 */
if((errno == EAGAIN) || (errno == EWOULDBLOCK))
{
break;
}
close(sockfd);
break;
}
else if(ret == 0)
{
close(sockfd);
}
else
{
const char *flag = "TCP data:";
send(sockfd, flag, 9, 0);
send(sockfd, buf, ret, 0);
}
}
}
else
{
printf("something else happened\n");
}
}
}
close(listenfd);
return 0;
}
运行#
modao@modao-hp:~/socket_io$ ./listen_tcp_and_udp 127.0.0.1 4523
使用telnet测试TCP:
modao@modao-hp:~/socket_io$ telnet 127.0.0.1 4523
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
123
TCP data:123
使用nc测试TCP和UDP:
modao@modao-hp:~/socket_io$ echo "Hello World!" | nc -4u 127.0.0.1 4523
UDP data:Hello World!
^C
modao@modao-hp:~/socket_io$ echo "Hello World!" | nc -4t 127.0.0.1 4523
TCP data:Hello World!
^C
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