同一埠監聽tcp和udp請求
阿新 • • 發佈：2019-01-10
問題：
眾所周知，同一臺機器的同一個埠只可以被一個程序使用，一般用於tcp，或者udp。那一個程序使用同一個埠同時監聽tcp、udp請求，是否可以呢？答案：可以。
程式碼：
server
為了同時監聽，server使用select進行多路訪問控制。
server端程式碼如下：
/*
TCP
INET
use select
*/
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<errno.h>
#include<sys/types.h>
#include<sys/socket.h> client
tcp client 程式碼如下：
/*
TCP
client
API
usage:
./client 192.168.1.78
notes:
client 端connect()成功之後，此時立刻關閉sockfd斷開連線，
server 端recv()會立刻返回，其返回值為0；
*/
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<errno.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#define SERVER_PORT 8888
#define MAXLINE 4096
int main(int argc, char** argv)
{
int sockfd, n;
char recvline[MAXLINE], sendline[MAXLINE];
struct sockaddr_in servaddr;
int recv_len;
int ret;
memset(recvline, 0, MAXLINE);
memset(sendline, 0, MAXLINE);
if (argc != 2) {
printf("usage: ./client <ipaddress>\n");
exit(0);
}
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
printf("create socket error: %s(errno: %d)\n", strerror(errno),errno);
exit(0);
}
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(SERVER_PORT);
if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0) {
printf("inet_pton error for %s/n",argv[1]);
close(sockfd);
exit(0);
}
if(connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0) {
printf("connect error: %s(errno: %d)/n",strerror(errno),errno);
close(sockfd);
exit(0);
}
/*sleep(10);close(sockfd);exit(0);*/
printf("send msg to server: \n");
fgets(sendline, MAXLINE - 1, stdin);
ret = send(sockfd, sendline, strlen(sendline), 0);
printf("the len of send data = %d.\n", ret);
if (ret < 0)
{
printf("send msg error: %s(errno: %d)\n", strerror(errno), errno);
close(sockfd);
exit(0);
} else if (ret == 0) {//return 0
printf("socket disconnnect(or the other side shutdown socket fd, or network problem) and send error: %s(errno: %d)\n",
strerror(errno), errno);
close(sockfd);
exit(0);
}
recv_len = recv(sockfd, recvline, MAXLINE - 1, 0);
if (recv_len < 0) {
printf("recv socket error: %s(errno: %d)\n",strerror(errno),errno);
close(sockfd);
exit(0);
} else if (recv_len == 0) {//return 0
printf("socket disconnnect(or the other side shutdown socket fd, or network problem) and recv error: %s(errno: %d)\n",
strerror(errno), errno);
close(sockfd);
exit(0);
}
recvline[recv_len] = '\0';
printf("from server: %s\n", recvline);
close(sockfd);
exit(0);
}
udp client 程式碼如下：
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<netdb.h>
#include<errno.h>
#include<sys/types.h>
int port=8888;
int main(int argc,char *argv[]){
int sockfd;
int i=0;
int z;
char buf[80],str1[80];
struct hostent *host;
struct sockaddr_in adr_srvr;
if(argc<2){
fprintf(stderr,"please enter the server's hostname!\n");
exit(1);
}
if((host=gethostbyname(argv[1]))==NULL){
herror("gethostbyname error!");
exit(1);
}
adr_srvr.sin_family=AF_INET;
adr_srvr.sin_port=htons(port);
adr_srvr.sin_addr=*((struct in_addr *)host->h_addr);
bzero(&(adr_srvr.sin_zero),8);
sockfd=socket(AF_INET,SOCK_DGRAM,0);
if(sockfd==-1){
perror("socket error!");
exit(1);
}
printf("msg to server:\n");
fgets(buf, sizeof(buf) - 1, stdin);
printf("send ....\n");
z=sendto(sockfd,buf,sizeof(buf),0,(struct sockaddr *)&adr_srvr,sizeof(adr_srvr));
if(z<0){
perror("sendto error");
exit(1);
}
sprintf(buf,"stop\n");
z=sendto(sockfd,buf,sizeof(buf),0,(struct sockaddr *)&adr_srvr,sizeof(adr_srvr));
if(z<0){
perror("sendto error");
exit(1);
}
close(sockfd);
exit(0);
}測試：
編譯
$ gcc server_tcp_udp.c -o server_tcp_udp.c
$ gcc tcp_client.c -o tcp_client.c
$ gcc udp_client.c -o udp_client.c啟動server
$ ./server_tcp_udp
$ ./server_tcp_udp
----------waiting for client's request---------
accept a new connection from client IP: 127.0.0.1, port: 60858
tcp recv:recv len = 30
recv msg 30 byte from client: Hello Server, I'm tcp client.
udp recv:recv msg 0 byte from client: Hello server, I'm udp client.
udp recv:recv msg 0 byte from client: stop
啟動tcp udp client
$ ./client_tcp 127.0.0.1
send msg to server:
Hello Server, I'm tcp client.
the len of send data = 30.
from server: recv well done.$ ./client_udp 127.0.0.1
msg to server:
Hello server, I'm udp client.
send ....可以看到，server端接到tcp client和udp client傳送的請求。