sock.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/******************************************************************************/
/*
 *	Add one to allow the user to write exactly SOCKET_BUFSIZ
 */

void socketSetBufferSize(int sid, int in, int line, int out)
{
	socket_t	*sp;

	if ((sp = socketPtr(sid)) == NULL) {
		return;
	}

	if (in >= 0) {
		ringqClose(&sp->inBuf);
		in++;
		ringqOpen(&sp->inBuf, in, in);
	}

	if (line >= 0) {
		ringqClose(&sp->lineBuf);
		line++;
		ringqOpen(&sp->lineBuf, line, line);
	}

	if (out >= 0) {
		ringqClose(&sp->outBuf);
		out++;
		ringqOpen(&sp->outBuf, out, out);
	}
}

/******************************************************************************/
/*
 *	Create a user handler for this socket. The handler called whenever there
 *	is an event of interest as defined by handlerMask (SOCKET_READABLE, ...)
 */

void socketCreateHandler(int sid, int handlerMask, socketHandler_t handler, 
		int data)
{
	socket_t	*sp;

	if ((sp = socketPtr(sid)) == NULL) {
		return;
	}
	sp->handler = handler;
	sp->handler_data = data;
	socketRegisterInterest(sp, handlerMask);
}

/******************************************************************************/
/*
 *	Delete a handler
 */

void socketDeleteHandler(int sid)
{
	socket_t	*sp;

	if ((sp = socketPtr(sid)) == NULL) {
		return;
	}
	sp->handler = NULL;
	socketRegisterInterest(sp, 0);
}

/******************************************************************************/
/*
 *	Socket output procedure. Return -1 on errors otherwise return the number
 *	of bytes written.
 */

static int socketDoOutput(socket_t *sp, char *buf, int toWrite, int *errCode)
{
	struct sockaddr_in	server;
	int					bytes;

	a_assert(sp);
	a_assert(buf);
	a_assert(toWrite > 0);
	a_assert(errCode);

	*errCode = 0;

#if WIN || CE
	if ((sp->flags & SOCKET_ASYNC)
			&& ! socketWaitForEvent(sp,  FD_CONNECT, errCode)) {
		return -1;
	}
#endif

/*
 *	Write the data
 */
	if (sp->flags & SOCKET_BROADCAST) {
		server.sin_family = AF_INET;
#if UEMF || LITTLEFOOT
		server.sin_addr.s_addr = INADDR_BROADCAST;
#else
		server.sin_addr.s_addr = inet_addr(basicGetBroadcastAddress());
#endif
		server.sin_port = htons((short)(sp->port & 0xFFFF));
		if ((bytes = sendto(sp->sock, buf, toWrite, 0,
			(struct sockaddr *) &server, sizeof(server))) < 0) {
			bytes = tryAlternateSendTo(sp->sock, buf, toWrite, 0,
			(struct sockaddr *) &server);
		}
	} else if (sp->flags & SOCKET_DATAGRAM) {
		server.sin_family = AF_INET;
		server.sin_addr.s_addr = inet_addr(sp->host);
		server.sin_port = htons((short)(sp->port & 0xFFFF));
		bytes = sendto(sp->sock, buf, toWrite, 0,
			(struct sockaddr *) &server, sizeof(server));

	} else {
		bytes = send(sp->sock, buf, toWrite, 0);
	}

	if (bytes < 0) {
		*errCode = socketGetError();
#if WIN || CE 
		sp->currentEvents &= ~FD_WRITE;
#endif

		return -1;

	} else if (bytes == 0 && bytes != toWrite) {
		*errCode = EWOULDBLOCK;
#if WIN || CE
		sp->currentEvents &= ~FD_WRITE;
#endif
		return -1;
	}

/*
 *	Ensure we get to write some more data real soon if the socket can absorb
 *	more data
 */
#if !UEMF
#if WIN 
	if (sp->interestEvents & FD_WRITE) {
		emfTime_t blockTime = { 0, 0 };
		emfSetMaxBlockTime(&blockTime);
	}
#endif /* WIN */
#endif
	return bytes;
}

/******************************************************************************/
/*
 *		If the sendto failed, swap the first two bytes in the 
 *		sockaddr structure.  This is a kludge due to a change in
 *		VxWorks between versions 5.3 and 5.4, but we want the 
 *		product to run on either.
 */
static int tryAlternateSendTo(int sock, char *buf, int toWrite, int i,
			struct sockaddr *server)
{
#if VXWORKS
	char *ptr;

	ptr = (char *)server;
	*ptr = *(ptr+1);
	*(ptr+1) = 0;
	return sendto(sock, buf, toWrite, i, server, sizeof(struct sockaddr));
#else
	return -1;
#endif /* VXWORKS */
}

/******************************************************************************/
/*
 *	Allocate a new socket structure
 */

int socketAlloc(char *host, int port, socketAccept_t accept, int flags)
{
	socket_t	*sp;
	int			sid;

	if ((sid = hAllocEntry((void***) &socketList, &socketMax,
			sizeof(socket_t))) < 0) {
		return -1;
	}
	sp = socketList[sid];

	sp->sid = sid;
	sp->accept = accept;
	sp->port = port;
	sp->fileHandle = -1;
	sp->saveMask = -1;

	if (host) {
		strncpy(sp->host, host, sizeof(sp->host));
	}

/*
 *	Preserve only specified flags from the callers open
 */
	a_assert((flags & ~(SOCKET_BROADCAST|SOCKET_DATAGRAM|SOCKET_BLOCK|
						SOCKET_LISTENING)) == 0);
	sp->flags = flags & (SOCKET_BROADCAST | SOCKET_DATAGRAM | SOCKET_BLOCK|
						SOCKET_LISTENING);

/*
 *	Add one to allow the user to write exactly SOCKET_BUFSIZ
 */
	ringqOpen(&sp->inBuf, SOCKET_BUFSIZ, SOCKET_BUFSIZ);
	ringqOpen(&sp->outBuf, SOCKET_BUFSIZ + 1, SOCKET_BUFSIZ + 1);
	ringqOpen(&sp->lineBuf, SOCKET_BUFSIZ, -1);

	return sid;
}

/******************************************************************************/
/*
 *	Free a socket structure
 */

void socketFree(int sid)
{
	socket_t	*sp;
	char_t		buf[256];
	int			i;

	if ((sp = socketPtr(sid)) == NULL) {
		return;
	}

/*
 *	To close a socket, remove any registered interests, set it to
 *	non-blocking so that the recv which follows won't block, do a
 *	shutdown on it so peers on the other end will receive a FIN,
 *	then read any data not yet retrieved from the receive buffer,
 *	and finally close it.  If these steps are not all performed
 *	RESETs may be sent to the other end causing problems.
 */
	socketRegisterInterest(sp, 0);
	if (sp->sock >= 0) {
		socketSetBlock(sid, 0);
		if (shutdown(sp->sock, 1) >= 0) {
			recv(sp->sock, buf, sizeof(buf), 0);
		}
#if WIN || CE
		closesocket(sp->sock);
#else
		close(sp->sock);
#endif
	}

	ringqClose(&sp->inBuf);
	ringqClose(&sp->outBuf);
	ringqClose(&sp->lineBuf);

	bfree(B_L, sp);
	socketMax = hFree((void***) &socketList, sid);

/*
 *	Calculate the new highest socket number
 */
	socketHighestFd = -1;
	for (i = 0; i < socketMax; i++) {
		if ((sp = socketList[i]) == NULL) {
			continue;
		} 
		socketHighestFd = max(socketHighestFd, sp->sock);
	}
}

/******************************************************************************/
/*
 *	Validate a socket handle
 */

socket_t *socketPtr(int sid)
{
	if (sid < 0 || sid >= socketMax || socketList[sid] == NULL) {
		a_assert(NULL);
		errno = EBADF;
		return NULL;
	}

	a_assert(socketList[sid]);
	return socketList[sid];
}

/******************************************************************************/
/*
 *	Get the operating system error code
 */

int socketGetError()
{
#if WIN || CE
	switch (WSAGetLastError()) {
	case WSAEWOULDBLOCK:
		return EWOULDBLOCK;
	case WSAECONNRESET:
		return ECONNRESET;
	case WSAENETDOWN:
		return ENETDOWN;
	case WSAEPROCLIM:
		return EAGAIN;
	case WSAEINTR:
		return EINTR;
	default:
		return EINVAL;
	}
#else
	return errno;
#endif
}

/******************************************************************************/
/*
 *	Return the underlying socket handle
 */

int socketGetHandle(int sid)
{
	socket_t	*sp;

	if ((sp = socketPtr(sid)) == NULL) {
		return -1;
	}
	return sp->sock;
}

/******************************************************************************/
/*
 *	Get blocking mode
 */

int socketGetBlock(int sid)
{
	socket_t	*sp;

	if ((sp = socketPtr(sid)) == NULL) {
		a_assert(0);
		return 0;
	}
	return (sp->flags & SOCKET_BLOCK);
}

/******************************************************************************/
/*
 *	Get mode
 */

int socketGetMode(int sid)
{
	socket_t	*sp;

	if ((sp = socketPtr(sid)) == NULL) {
		a_assert(0);
		return 0;
	}
	return sp->flags;
}

/******************************************************************************/
/*
 *	Set mode
 */

void socketSetMode(int sid, int mode)
{
	socket_t	*sp;

	if ((sp = socketPtr(sid)) == NULL) {
		a_assert(0);
		return;
	}
	sp->flags = mode;
}

/******************************************************************************/
/*
 *	Get port.
 */

int socketGetPort(int sid)
{
	socket_t	*sp;

	if ((sp = socketPtr(sid)) == NULL) {
		return -1;
	}
	return sp->port;
}

/******************************************************************************/