聊一聊网络的那点事

最近在抓一些基础，所以偶尔也会写一些实例程序，可能写的有点糙，所以拿上来大伙品评品评。

服务端代码：

#include 
#include 
#include 
#pragma comment(lib,"ws2_32")
#define PORT 5150
#define DATA_BUFSIZE 8192
typedef struct _SOCKET_INFORMATION {
	OVERLAPPED Overlapped;
	SOCKET Socket;
	CHAR Buffer[DATA_BUFSIZE];
	WSABUF DataBuf;
	DWORD BytesSEND;
	DWORD BytesRECV;
} SOCKET_INFORMATION, *LPSOCKET_INFORMATION;
void CALLBACK WorkerRoutine(DWORD Error, DWORD BytesTransferred, LPWSAOVERLAPPED Overlapped, DWORD InFlags);
DWORD WINAPI WorkerThread(LPVOID lpParameter);
SOCKET AcceptSocket;
int main(int argc, char **argv)
{
	WSADATA wsaData;
	SOCKET ListenSocket;
	SOCKADDR_IN InternetAddr;
	INT Ret;
	HANDLE ThreadHandle;
	DWORD ThreadId;
	WSAEVENT AcceptEvent;
	if ((Ret = WSAStartup((2, 2), &wsaData)) != 0)
	{
		printf("WSAStartup() failed with error %d\n", Ret);
		WSACleanup();
		return 1;
	}
	else
		printf("WSAStartup() is OK!\n");
	if ((ListenSocket = WSASocket(AF_INET, SOCK_STREAM, 0, NULL, 0, WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET)
	{
		printf("Failed to get a socket %d\n", WSAGetLastError());
		return 1;
	}
	else
		printf("WSASocket() is pretty fine!\n");
	InternetAddr.sin_family = AF_INET;
	InternetAddr.sin_addr.s_addr = htonl(INADDR_ANY);
	InternetAddr.sin_port = htons(PORT);
	if (bind(ListenSocket, (PSOCKADDR)&InternetAddr, sizeof(InternetAddr)) == SOCKET_ERROR)
	{
		printf("bind() failed with error %d\n", WSAGetLastError());
		return 1;
	}
	else
		printf("bind() is OK!\n");
	if (listen(ListenSocket, 5))
	{
		printf("listen() failed with error %d\n", WSAGetLastError());
		return 1;
	}
	else
		printf("listen() is OK!\n");
	if ((AcceptEvent = WSACreateEvent()) == WSA_INVALID_EVENT)
	{
		printf("WSACreateEvent() failed with error %d\n", WSAGetLastError());
		return 1;
	}
	else
		printf("WSACreateEvent() is OK!\n");
	// Create a worker thread to service completed I/O requests
	if ((ThreadHandle = CreateThread(NULL, 0, WorkerThread, (LPVOID)AcceptEvent, 0, &ThreadId)) == NULL)
	{
		printf("CreateThread() failed with error %d\n", GetLastError());
		return 1;
	}
	else
		printf("CreateThread() should be fine!\n");
	while (TRUE)
	{
		AcceptSocket = accept(ListenSocket, NULL, NULL);
		if (WSASetEvent(AcceptEvent) == FALSE)
		{
			printf("WSASetEvent() failed with error %d\n", WSAGetLastError());
			return 1;
		}
		else
			printf("WSASetEvent() should be working!\n");
	}
}
DWORD WINAPI WorkerThread(LPVOID lpParameter)
{
	DWORD Flags;
	LPSOCKET_INFORMATION SocketInfo;
	WSAEVENT EventArray[1];
	DWORD Index;
	DWORD RecvBytes;
	// Save the accept event in the event array
	EventArray[0] = (WSAEVENT)lpParameter;
	while (TRUE)
	{
		// Wait for accept() to signal an event and also process WorkerRoutine() returns
		while (TRUE)
		{
			Index = WSAWaitForMultipleEvents(1, EventArray, FALSE, WSA_INFINITE, TRUE);
			if (Index == WSA_WAIT_FAILED)
			{
				printf("WSAWaitForMultipleEvents() failed with error %d\n", WSAGetLastError());
				return FALSE;
			}
			else
				printf("WSAWaitForMultipleEvents() should be OK!\n");
			if (Index != WAIT_IO_COMPLETION)
			{
				// An accept() call event is ready - break the wait loop
				break;
			}
		}
		WSAResetEvent(EventArray[Index - WSA_WAIT_EVENT_0]);
		// Create a socket information structure to associate with the accepted socket
		if ((SocketInfo = (LPSOCKET_INFORMATION)GlobalAlloc(GPTR, sizeof(SOCKET_INFORMATION))) == NULL)
		{
			printf("GlobalAlloc() failed with error %d\n", GetLastError());
			return FALSE;
		}
		else
			printf("GlobalAlloc() for SOCKET_INFORMATION is OK!\n");
		// Fill in the details of our accepted socket
		SocketInfo->Socket = AcceptSocket;
		ZeroMemory(&(SocketInfo->Overlapped), sizeof(WSAOVERLAPPED));
		SocketInfo->BytesSEND = 0;
		SocketInfo->BytesRECV = 0;
		SocketInfo->DataBuf.len = DATA_BUFSIZE;
		SocketInfo->DataBuf.buf = SocketInfo->Buffer;
		Flags = 0;
		if (WSARecv(SocketInfo->Socket, &(SocketInfo->DataBuf), 1, &RecvBytes, &Flags,
			&(SocketInfo->Overlapped), WorkerRoutine) == SOCKET_ERROR)
		{
			if (WSAGetLastError() != WSA_IO_PENDING)
			{
				printf("WSARecv() failed with error %d\n", WSAGetLastError());
				return FALSE;
			}
		}
		else
			printf("recv socket s %d ,WSARecv() is OK! the recv is %s\n",SocketInfo->Socket,SocketInfo->DataBuf.buf);
		printf("Socket %d got connected...\n", AcceptSocket);
	}
	return TRUE;
}
void CALLBACK WorkerRoutine(DWORD Error, DWORD BytesTransferred, LPWSAOVERLAPPED Overlapped, DWORD InFlags)
{
	DWORD SendBytes, RecvBytes;
	DWORD Flags;
	// Reference the WSAOVERLAPPED structure as a SOCKET_INFORMATION structure
	LPSOCKET_INFORMATION SI = (LPSOCKET_INFORMATION)Overlapped;
	if (Error != 0)
	{
		printf("I/O operation failed with error %d\n", Error);
	}
	if (BytesTransferred == 0)
	{
		printf("Closing socket %d\n\n", SI->Socket);
	}
	if (Error != 0 || BytesTransferred == 0)
	{
		closesocket(SI->Socket);
		GlobalFree(SI);
		return;
	}
	// Check to see if the BytesRECV field equals zero. If this is so, then
	// this means a WSARecv call just completed so update the BytesRECV field
	// with the BytesTransferred value from the completed WSARecv() call
	if (SI->BytesRECV == 0)
	{
		SI->BytesRECV = BytesTransferred;
		SI->BytesSEND = 0;
	}
	else
	{
		SI->BytesSEND += BytesTransferred;
	}
	if (SI->BytesRECV > SI->BytesSEND)
	{

		ZeroMemory(&(SI->Overlapped), sizeof(WSAOVERLAPPED));
		SI->DataBuf.buf = SI->Buffer + SI->BytesSEND;
		SI->DataBuf.len = SI->BytesRECV - SI->BytesSEND;
		if (WSASend(SI->Socket, &(SI->DataBuf), 1, &SendBytes, 0, &(SI->Overlapped), WorkerRoutine) == SOCKET_ERROR)
		{
			if (WSAGetLastError() != WSA_IO_PENDING)
			{
				printf("WSASend() failed with error %d\n", WSAGetLastError());
				return;
			}
		}
		else
			printf("to say socket s %d, WSASend() is OK! the send buffer is %s\n",SI->Socket,SI->DataBuf.buf);
	}
	else
	{
		SI->BytesRECV = 0;
		Flags = 0;
		ZeroMemory(&(SI->Overlapped), sizeof(WSAOVERLAPPED));
		SI->DataBuf.len = DATA_BUFSIZE;
		SI->DataBuf.buf = SI->Buffer;
		if (WSARecv(SI->Socket, &(SI->DataBuf), 1, &RecvBytes, &Flags, &(SI->Overlapped), WorkerRoutine) == SOCKET_ERROR)
		{
			if (WSAGetLastError() != WSA_IO_PENDING)
			{
				printf("WSARecv() failed with error %d\n", WSAGetLastError());
				return;
			}
		}
		else
			printf("WSARecv() is fine!\n");
	}
}

客户端代码：

#include 
#include 
#include 



#ifdef WIN32
#include
#include 
#include 
#pragma comment(lib, "ws2_32")
#endif
#define TEST_BUFFER   "Hello World"

int main(int argc, char** argv) {

#ifdef WIN32
	WORD wVersionRequested;
	WSADATA wsaData;
	int err;
	wVersionRequested = MAKEWORD(2, 2);

	err = WSAStartup(wVersionRequested, &wsaData);
	if (err != 0) {
		return -1;
	}
#endif

	int s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (s == INVALID_SOCKET) {
		return -1;
	}
	struct sockaddr_in sockaddr;

	inet_pton(AF_INET, "127.0.0.1", &sockaddr.sin_addr.S_un.S_addr);
	sockaddr.sin_family = AF_INET;
	sockaddr.sin_port = htons(5150);

	int ret = connect(s, ((struct sockaddr*) &sockaddr), sizeof(sockaddr));
	if (ret != 0) {
		printf("connect error\n");
		closesocket(s);
		system("pause");
		goto out;
		return -1;
	}
	printf("connect success\n");

	char buffer[1024] = { 0 };
	memcpy(buffer, TEST_BUFFER, 1024);
	printf("socket s %d send buffer is %s\n", s,buffer);
	 ret = send(s, buffer, 1024, 0);
	 int iCount = 0;
	while (ret > 0 && iCount < 10)
	{
		memset(buffer, 0, 1024);
		ret = recv(s, buffer, 1024, 0);
		printf("socket s  %d recv buffer is %s\n", s,buffer);
		send(s, buffer, 1024, 0);
		iCount++;
	}
	system("pause");

	closesocket(s);
out:
#ifdef WIN32
	WSACleanup();
#endif
	return 0;
}

哈，权且记录下，持续学习中。