linux *** 作系统tcp时间戳不敏感的设置

1、要将net.ipv4.tcp_timestamps的值设置为0，请运行sysctl-wnet.ipv4.tcp_timestamps=0命令。

2、在默认sysctl.conf文件中添加net.ipv4.tcp_timestamps=0值。

如果你确定,真的不需要等这么久,或者用户希望可以随时中上连接过程,那么一般是用 非阻塞模式来做的. 看看我的这段连接代码(节选),可以作为TCP连接的典范:

bool CRemoteLink::Connect()

{

OnDisconnected() // 如果已经连接，则断开

if(!m_bUseProxy)

{

m_iConnStatus = SS_CONNECTING // 正在连接状态

GNTRACE ("开始连接到远程服务器[%s][%ld]...\n", m_strip.c_str(), m_port)

// 建立套接字, 准备连接到服务器

m_socket = ::socket(AF_INET, SOCK_STREAM, 0)

if (socket <0) {

if(m_pCallBack)

m_pCallBack->OnSocketError(SE_CREATE, MSG_SE_CREATE)

return false

}

// 设为异步 *** 作方式

unsigned long on = 1

if (::ioctlsocket(m_socket, FIONBIO, &on) <0) {

::closesocket(m_socket)

if(m_pCallBack)

m_pCallBack->OnSocketError(SE_CREATE, MSG_SE_CREATE)

return false

}

sockaddr_in addr

memset(&addr, 0, sizeof(addr))

addr.sin_family = AF_INET

addr.sin_addr.s_addr = inet_addr(m_strip.c_str())

addr.sin_port = htons(m_port)

int rt

rt = ::connect(m_socket, (sockaddr *) &addr, sizeof(addr))

if (rt == 0) {

OnConnected()

return true

}

// ==================================================================

timeval to

// 首先建立连接

fd_set wfds

fd_set efds

FD_ZERO(&wfds)

FD_ZERO(&efds)

// test shutdown event each 100ms.

to.tv_sec = 0

// CONNECT_TIMEOUT

to.tv_usec = 100000

int it = 0

while(!m_meShutdown.Wait(0) &&!m_meConnStop.Wait(0))

{

FD_SET(m_socket, &wfds)

FD_SET(m_socket, &efds)

int n = select(m_socket + 1, NULL, &wfds, &efds, &to)

if (n >0) {

if(FD_ISSET(m_socket, &wfds))

{

OnConnected()

return true

}

else

{

//int err = ::WSAGetLastError()

//const char* msg = GetLastErrorMessage(err)

GNTRACE ("CRemoteLink::Connect : connection attempt failed!\n")

if(m_pCallBack)

m_pCallBack->OnSocketError(SE_CONN, MSG_SE_CONN)

break

}

} else if (n <0) { // Select Error

int err = ::WSAGetLastError()

const char* msg = GetLastErrorMessage(err)

GNTRACE ("CRemoteLink::Connect : Select Error.[%d] - %s\n", err, msg)

if(m_pCallBack)

m_pCallBack->OnSocketError(err, msg)

break

}

else

{

it += 100

if(it >30000) // 连接超时 -- (30S)

{

GNTRACE ("CRemoteLink::Connect : Time out.\n")

if(m_pCallBack)

m_pCallBack->OnSocketError(SE_TIMEOUT, MSG_SE_TIMEOUT)

break

}

}

}

if(m_meConnStop.Wait(0))

{

GNTRACE("连接过程进行时被取消。\n")

}

}

else

{

// 通过代理服务器连接

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