ttttttttt.c

来自「串口代理」· C语言 代码 · 共 195 行

#include "tcpsock.h"
int InitPassiveSock(char * servicename) 
/* Initialize Passive Socket. If succeed then return 1, else return error code (<0) */
/* 此函数用于需要被动套接字的服务器程序，它除了获取服务信息外，还建立
一个被动套接字。*/
{
	int mainsock, flag=1;
	struct servent *servrec;
	struct sockaddr_in serv_addr;
	if ((servrec = getservbyname(servicename, "tcp")) == NULL) 
	{
		return(-1);
	}
	bzero((char *)&Mysock, sizeof(Sockets));
	Mysock.Port = servrec->s_port; /* Service Port in Network Byte Order */
	if((mainsock = socket(AF_INET, SOCK_STREAM, 0)) < 0) 
	{
		return(-2);
	}
	bzero((char *)&serv_addr, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY); /* 任意网络接口 */
	serv_addr.sin_port = servrec->s_port;
	if (bind(mainsock, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) < 0)
	{
		close(mainsock);
		return(-3);
	}
	if (listen(mainsock, 5) == -1)
	{ /* 将主动套接字变为被动套接字，准备好接收连接 */

		close(mainsock);
		return(-4);
	}
/* Set this socket as a Non-blocking socket. */
	if (ioctl(mainsock, FIONBIO, &flag) == -1) {
	close(mainsock);
	return(-5);
	}
	Mysock.DaemonSock = mainsock;
	FD_SET(mainsock, &Mysock.readfds); /* 申明对主套接字"可读"感兴趣 */
	FD_SET(mainsock, &Mysock.exceptfds); /* 申明对主套接字上例外事件感兴趣 */
	return(1); 
}
void CloseMainSock()
// 关闭主套接字，并清除对它上面事件的申明。在程序结束前关闭主套接字是一个好习惯
{
	close(Mysock.DaemonSock);
	FD_CLR(Mysock.DaemonSock, &Mysock.readfds);
	FD_CLR(Mysock.DaemonSock, &Mysock.exceptfds);
}

int CreateConnection(struct in_addr *sin_addr)
/* Create a Connection to remote host which IP address is in sin_addr. 
Param: sin_addr indicates the IP address in Network Byte Order. 
if succeed return the socket number which indicates this connection,
else return error code (<0) */
{
	struct sockaddr_in server; /* server address */
	int tmpsock, flag=1, i;
	if ((tmpsock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	return(-1);
	server.sin_family = AF_INET;
	server.sin_port = Mysock.Port;
	server.sin_addr.s_addr = sin_addr->s_addr;
	/* Set this socket as a Non-blocking socket. */
	if (ioctl(tmpsock, FIONBIO, &flag) == -1) 
	{
		close(tmpsock);
		return(-2);
	}
/* Connect to the server. */
	if (connect(tmpsock, (struct sockaddr *)&server, sizeof(server)) < 0) 
	{
		if ((errno != EWOULDBLOCK) && (errno != EINPROGRESS))
		{
		/* 如果错误代码是EWOULDBLOCK和EINPROGRESS，则不用关闭套接字，因为系统将在之后继续为套接字建立连接，连接是否建立成功可用select()函数来检测套接字是否"可写"来确定。*/
			close(tmpsock);
			return(-3); /* Connect error. */
		}
	}
	FD_SET(tmpsock, &Mysock.readfds);
	FD_SET(tmpsock, &Mysock.writefds);
	FD_SET(tmpsock, &Mysock.exceptfds);
	i = 0;
	while (Mysock.Sockets[i] != 0) i++; /* look for a blank sockets position */
	if (i >= 64) 
	{
		close(tmpsock);
		return(-4); /* too many connections */
	}
	Mysock.Sockets[i] = tmpsock;
	Mysock.SockNum++;
	return(i);
}
int AcceptConnection(struct in_addr *IPaddr)
/* Accept a connection. If succeed, return the data sockets number, else return -1. */
{
	int newsock, len, flag=1, i;
	struct sockaddr_in addr;
	len = sizeof(addr);
	bzero((char *)&addr, len);< BR>if ((newsock = accept(Mysock.DaemonSock, &addr, &len)) == -1) 
	return(-1); /* Accept error. */
	/* Set this socket as a Non-blocking socket. */
	ioctl(newsock, FIONBIO, &flag);
	FD_SET(newsock, &Mysock.readfds);
	FD_SET(newsock, &Mysock.writefds);
	FD_SET(newsock, &Mysock.exceptfds);
	/* Return IP address in the Parameter. */
	IPaddr->s_addr = addr.sin_addr.s_addr;
	i = 0;
	while (Mysock.Sockets[i] != 0) i++; /* look for a blank sockets position */
	if (i >= 64) 
	{
		close(newsock);
		return(-4); /* too many connections */
	}
	Mysock.Sockets[i] = newsock;
	Mysock.SockNum++;
	return(i);
}
int CloseConnection(int Sockno)
/* Close a connection indicated by Sockno. */
{
	int retcode;
	if ((Sockno >= 64) || (Sockno < 0) || (Mysock.Sockets[Sockno] == 0))
	return(0);
	retcode = close(Mysock.Sockets[Sockno]);
	FD_CLR(Mysock.Sockets[Sockno], &Mysock.readfds);
	FD_CLR(Mysock.Sockets[Sockno], &Mysock.writefds);
	FD_CLR(Mysock.Sockets[Sockno], &Mysock.exceptfds);
	Mysock.Sockets[Sockno] = 0;
	Mysock.SockNum--;
	return(retcode);
}
int QuerySocketsMsg()
/* Query Sockets Message. If succeed return message number, else return -1.
The message information stored in struct SockMsg. */
{
	fd_set rfds, wfds, efds;
	int retcode, i;
	struct timeval TimeOut;
	rfds = Mysock.readfds;
	wfds = Mysock.writefds;
	efds = Mysock.exceptfds;
	TimeOut.tv_sec = 0; /* 立即返回，不阻塞。*/	
	TimeOut.tv_usec = 0;
	bzero((char *)&SockMsg, sizeof(SockMsg));
	if ((retcode = select(64, &rfds, &wfds, &efds, &TimeOut)) == 0)
		return(0);
	if (FD_ISSET(Mysock.DaemonSock, &rfds))
		SockMsg.AcceptNum = 1; /* some client call server. */
	for (i=0; i<64; i++) /* Data in message */
	{
		if ((Mysock.Sockets[i] > 0) && (FD_ISSET(Mysock.Sockets[i], &rfds))) 
		SockMsg.ReadQueue[SockMsg.ReadNum++] = i;
	}
	for (i=0; i<64; i++) /* Data out ready message */
	{
		if ((Mysock.Sockets[i] > 0) && (FD_ISSET(Mysock.Sockets[i], &wfds))) 
		SockMsg.WriteQueue[SockMsg.WriteNum++] = i;
	}
	if (FD_ISSET(Mysock.DaemonSock, &efds))
		SockMsg.AcceptNum = -1; /* server socket error. */
	for (i=0; i<64; i++) /* Error message */
	{
		if ((Mysock.Sockets[i] > 0) && (FD_ISSET(Mysock.Sockets[i], &efds))) 
		SockMsg.ExceptQueue[SockMsg.ExceptNum++] = i;
	}
		return(retcode);
}

int SendPacket(int Sockno, void *buf, int len)
	/* Send a packet. If succeed return the number of send data, else return -1 */ 
{
		int actlen;
		if ((Sockno >= 64) || (Sockno < 0) || (Mysock.Sockets[Sockno] == 0))
		return(0);
		if ((actlen = send(Mysock.Sockets[Sockno], buf, len, 0)) < 0)
		return(-1);
		return(actlen);
}

int RecvPacket(int Sockno, void *buf, int size)
	/* Receive a packet. If succeed return the number of receive data, elseif the connection
	is shutdown by peer then return 0, otherwise return 0-errno */ 
{
	int actlen;
	if ((Sockno >= 64) || (Sockno < 0) || (Mysock.Sockets[Sockno] == 0))
	return(0);
	if ((actlen = recv(Mysock.Sockets[Sockno], buf, size, 0)) < 0)
	return(0-errno);
	return(actlen); /* actlen是接收的数据长度，如果为零，指示连接被对方关闭。*/
}