- int getsockopt(int sockfd,int level,int optname,void *optval,socklen_t *optlen)
- int setsockopt(int sockfd,int level,int optname,const void *optval,socklen_t *optlen)
level指定控制套接字的层次.可以取三种值:
1)SOL_SOCKET:通用套接字选项.
2)IPPROTO_IP:IP选项.
3)IPPROTO_TCP:TCP选项.
optname指定控制的方式(选项的名称),我们下面详细解释
optval获得或者是设置套接字选项.根据选项名称的数据类型进行转换
选项名称 说明 数据类型
========================================================================
SOL_SOCKET
------------------------------------------------------------------------
SO_BROADCAST 允许发送广播数据 int
SO_DEBUG 允许调试 int
SO_DONTROUTE 不查找路由 int
SO_ERROR 获得套接字错误 int
SO_KEEPALIVE 保持连接 int
SO_LINGER 延迟关闭连接 struct linger
SO_OOBINLINE 带外数据放入正常数据流 int
SO_RCVBUF 接收缓冲区大小 int
SO_SNDBUF 发送缓冲区大小 int
SO_RCVLOWAT 接收缓冲区下限 int
SO_SNDLOWAT 发送缓冲区下限 int
SO_RCVTIMEO 接收超时 struct timeval
SO_SNDTIMEO 发送超时 struct timeval
SO_REUSERADDR 允许重用本地地址和端口 int
SO_TYPE 获得套接字类型 int
SO_BSDCOMPAT 与BSD系统兼容 int
==========================================================================
IPPROTO_IP
--------------------------------------------------------------------------
IP_HDRINCL 在数据包中包含IP首部 int
IP_OPTINOS IP首部选项 int
IP_TOS 服务类型
IP_TTL 生存时间 int
==========================================================================
IPPRO_TCP
--------------------------------------------------------------------------
TCP_MAXSEG TCP最大数据段的大小 int
TCP_NODELAY 不使用Nagle算法 int
=========================================================================
{
//////////////////////////////////////////////////////////////////////////
// SocketOptionSrv.cpp
// 套接字选项 —— 设置缓冲大小（扩大10倍）
#include <iostream.h>
#include <winsock2.H>
#define BUF_SIZE 64
#pragma comment(lib,"ws2_32.lib")
int main(int argc,char* argv[])
{
WSADATA wsd;
SOCKET s;
SOCKADDR_IN servAddr;
char bufRecv[BUF_SIZE];
char bufSend[BUF_SIZE];
// 初始化套接字
if(WSAStartup(MAKEWORD(2,2),&wsd))
{
cout<<"WSAStartup failed !/n"<<endl;
return 1;
}
// 连理套接字
s = socket(AF_INET,SOCK_DGRAM,0);
if(INVALID_SOCKET == s)
{
cout<<"socket failed !/n"<<endl;
WSACleanup();
return 1;
}
int nErrorCode;
int nBufLen;
int nOptLen = sizeof(nBufLen);
// 获取当前套接字s的接受数据缓冲区大小
nErrorCode = getsockopt(s,SOL_SOCKET,SO_RCVBUF,(char*)&nBufLen,&nOptLen);
if(SOCKET_ERROR == nErrorCode)
{
cout<<"getsockopt failed !/n"<<endl;
WSACleanup();
return 1;
}
// 设置当前套接字s的接受数据缓冲区为原来的10倍
nBufLen *= 10;
nErrorCode = setsockopt(s,SOL_SOCKET,SO_RCVBUF,(char*)&nBufLen,nOptLen);
if(SOCKET_ERROR == nErrorCode)
{
cout<<"setsockopt failed !/n"<<endl;
WSACleanup();
return 1;
}
// 检查套接字s的接受缓冲区是否设置成功
int uiNewRcvBuf;
getsockopt(s,SOL_SOCKET,SO_RCVBUF,(char*)&uiNewRcvBuf,&nOptLen);
if(SOCKET_ERROR == nErrorCode || uiNewRcvBuf != nBufLen)
{
cout<<"The buf isn't same from Recv."<<endl;
WSACleanup();
return 1;
}
// 设置服务器现象
servAddr.sin_family = AF_INET;
servAddr.sin_port = htons(5000);
servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
// 绑定套接字
if(bind(s,(SOCKADDR *)&servAddr,sizeof(SOCKADDR)) == SOCKET_ERROR)
{
cout<<"bind failed:"<<WSAGetLastError()<<endl;
closesocket(s);
WSACleanup();
return 1;
}
SOCKADDR_IN clientAddr;
int nClientLen;
// 缓冲区待发送的数据
ZeroMemory(bufRecv,BUF_SIZE);
ZeroMemory(bufSend,BUF_SIZE);
strcpy(bufSend,"Hello World !");
nClientLen = sizeof(clientAddr);
while(1)
{
// 从客户端接受数据
if(recvfrom(s,bufRecv,BUF_SIZE,0,(SOCKADDR *)&clientAddr,&nClientLen) == SOCKET_ERROR)
{
cout<<"recv failed:"<<WSAGetLastError()<<endl;
closesocket(s);
WSACleanup();
return 1;
}
cout<<"Recv From Client:"<<bufRecv<<endl;
// 向服务器发送数据
if(sendto(s,bufSend,BUF_SIZE,0,(SOCKADDR *)&clientAddr,nClientLen) == SOCKET_ERROR)
{
cout<<"send to Client failed:"<<WSAGetLastError()<<endl;
closesocket(s);
WSACleanup();
return 1;
}
}
// 关闭套接字，释放资源
closesocket(s);
WSACleanup();
return 0;
}
{
//////////////////////////////////////////////////////////////////////////
// SocketOptionClient.cpp
// 套接字选项 —— 设置缓冲大小（扩大10倍）
#include <iostream.h>
#include <winsock2.H>
#define BUF_SIZE 64
#pragma comment(lib,"ws2_32.lib")
int main(int argc,char* argv[])
{
WSADATA wsd;
SOCKET s;
SOCKADDR_IN servAddr;
char bufRecv[BUF_SIZE];
char bufSend[BUF_SIZE];
// 初始化套接字
if(WSAStartup(MAKEWORD(2,2),&wsd))
{
cout<<"WSAStartup failed !/n"<<endl;
return 1;
}
// 建立套接字
s = socket(AF_INET,SOCK_DGRAM,0);
if(INVALID_SOCKET == s)
{
cout<<"socket failed !/n"<<endl;
WSACleanup();
return 1;
}
// 缓冲区待发送的数据
ZeroMemory(bufSend,BUF_SIZE);
ZeroMemory(bufRecv,BUF_SIZE);
strcpy(bufSend,"Hello World !");
// 设置服务器选项
servAddr.sin_family = AF_INET;
servAddr.sin_addr.s_addr = inet_addr("192.168.1.254");
servAddr.sin_port = htons(5000);
int nServerlen = sizeof(servAddr);
while(1)
{
// 向服务器发送数据
if(sendto(s,bufSend,BUF_SIZE,0,(SOCKADDR *)&servAddr,nServerlen) == SOCKET_ERROR)
{
cout<<"sendto failed:"<<WSAGetLastError()<<endl;
closesocket(s);
WSACleanup();
return 1;
}
// 从服务器接受数据
if(recvfrom(s,bufRecv,BUF_SIZE,0,(SOCKADDR *)&servAddr,&nServerlen) == SOCKET_ERROR)
{
cout<<"recv failed:"<<WSAGetLastError()<<endl;
closesocket(s);
WSACleanup();
return 1;
}
cout<<"Recv From Server:"<<bufRecv<<endl;
}
// 关闭套接字，释放资源
closesocket(s);
WSACleanup();
return 0;
}
}
}