话不多说，直接上源码。
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/**
*@author walker
*@date 2012.9
*/
#include <unistd.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define UDP_PORT 6000 //预定义的端口号
#define MAXSIZE 8192
//实际使用端口号
int
g_udp_port = UDP_PORT;
//用于回显的函数
void
echo_fn(
int
sockfd);
int
main(
int
argc,
char
*argv[])
{
//获取用户输入的端口号
if
(argc > 1)
{
g_udp_port =
atoi
(argv[1]);
}
if
(g_udp_port <= 0 || g_udp_port > 65535)
{
perror
(
"Invalid port.\n"
);
return
-1;
}
int
sockfd;
//套接字描述符
struct
sockaddr_in6 addr;
//用于UDP的IPv6地址结构
if
((sockfd = socket(AF_INET6, SOCK_DGRAM,0)) == -1)
{
printf
(
"Error in socket\n"
);
return
-1;
}
bzero(&addr,
sizeof
(addr));
addr.sin6_family = AF_INET6;
addr.sin6_port = htons(g_udp_port);
addr.sin6_addr = in6addr_any;
if
(bind(sockfd, (
struct
sockaddr *)&addr,
sizeof
(
struct
sockaddr_in6)) == -1)
{
printf
(
"Error in binding\n"
);
return
-1;
}
echo_fn(sockfd);
//调用回显函数
close(sockfd);
//关闭套接字
return
-1;
}
//用于回显的函数
void
echo_fn(
int
sockfd)
{
char
data[MAXSIZE];
int
n = 0;
socklen_t len =
sizeof
(
struct
sockaddr_in6);
struct
sockaddr_in6 addr;
while
(1)
{
printf
(
"Waiting for data...\n"
);
//接受从客户端发来的数据
if
((n = recvfrom(sockfd, data, MAXSIZE, 0, (
struct
sockaddr *)&addr, &len)) == -1)
{
printf
(
"Error in receiving\n"
);
exit
(-1);
}
data[n] =
'\0'
;
printf
(
"Received data: %s\n"
, data);
//将收到的数据再发送回去
sendto(sockfd, data, n, 0, (
struct
sockaddr *)&addr, len);
//存储用"冒号十六进制记法"表示的IPv6地址
char
buf_addr[40];
//将IPv6地址转为"冒号十六进制记法"(colon hexadecimal notation)表示
inet_ntop(AF_INET6, &addr.sin6_addr, buf_addr, 64);
printf
(
"Client ip: %s\n"
, buf_addr);
printf
(
"Client port: %d\n"
, ntohs(addr.sin6_port));
printf
(
"\n"
);
}
}
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*** walker ***
本文转自walker snapshot博客51CTO博客，原文链接http://blog.51cto.com/walkerqt/1006583如需转载请自行联系原作者
RQSLT
