data.c

网络数据管理协议的开发

 *   env_len   (input) - length of env_val.
 *
 * Returns:
 *   NDMP_NO_ERR - backup successfully started.
 *   otherwise - error code of backup start error.
 */
static ndmp_error
startBackup(NdmpdSession*		session,
			char*				bu_type,
			ndmp_pval*			env_val,
			u_long				env_len)
{
	ndmp_data_start_backup_reply	reply;
	NdmpdModuleParams				params;
	int								err;
	
	Debug(DBG_CAT_DATA|DBG_FOC_FLOW,
		  "startBackup: bu_type:%s\n",
		  bu_type);

	memset((void*)&reply, 0, sizeof(reply));
	
	if (session->data.state != NDMP_DATA_STATE_CONNECTED)
	{
		Error(LOG_ERR,
			  "startBackup: can't start new backup in current state.\n");
		return(NDMP_ILLEGAL_STATE_ERR);
	}

	if (session->data.moverAddr.addr_type == NDMP_ADDR_LOCAL)
	{
		if (session->tape.mode == NDMP_TAPE_READ_MODE)
		{
			Error(LOG_ERR,
				  "startBackup: write protected device.\n");
			return(NDMP_WRITE_PROTECT_ERR);
		}
	}

	if (strcmp(bu_type, "dump") != 0)
	{
		Error(LOG_ERR,
			  "startBackup: Invalid backup type:%s specified.\n",
			  bu_type);
		return(NDMP_ILLEGAL_ARGS_ERR);
	}
	
	if ((err = ndmpdSaveEnv(session,
							env_val,
							env_len)) != NDMP_NO_ERR)
	{
		return(err);
	}
	
	params.daemonCookie          = (void *)session;
	params.moduleCookie          = &session->data.module.moduleCookie;
	params.protocolVersion       = session->protocolVersion;
	params.operation             = NDMP_DATA_OP_BACKUP;
	params.getEnvFunc            = ndmpdApiGetEnv;
	params.addEnvFunc            = ndmpdApiAddEnv;
	params.getNameFunc           = ndmpdApiGetName;
	params.dispatchFunc          = ndmpdApiDispatch;
	params.doneFunc              = ndmpdApiDone;
	params.logFunc               = ndmpdApiLog;
	params.addFileHandlerFunc    = ndmpdApiAddFileHandler;
	params.removeFileHandlerFunc = ndmpdApiRemoveFileHandler;
	params.writeFunc             = ndmpdApiWrite;
	params.fileHistoryFileFunc   = ndmpdApiFileHistoryFile;
	params.fileHistoryDirFunc    = ndmpdApiFileHistoryDir;
	params.fileHistoryNodeFunc   = ndmpdApiFileHistoryNode;
	params.readFunc              = 0;
	params.fileRecoveredFunc     = 0;
	params.stats                 = &session->data.module.stats;
	
	session->data.module.moduleCookie            = 0;
	session->data.module.startFunc               = simpleStart;
	session->data.module.abortFunc               = simpleAbort;
	session->data.module.stats.bytesProcessed    = 0;
	session->data.module.stats.estBytesRemaining = 0;
	session->data.module.stats.estTimeRemaining  = 0;
	session->data.nlist           = 0;
	session->data.nlistLen        = 0;
	session->data.readOffset      = 0;
	session->data.readLength      = 0;
	
	reply.error = NDMP_NO_ERR;
	if (ndmpSendReply(session->connection, NDMP_NO_ERR, (void *)&reply) < 0)
	{
		Error(LOG_ERR,
			  "startBackup: error sending data_start_backup reply.\n");
		return(NDMP_NO_ERR);
	}

	session->data.state     = NDMP_DATA_STATE_ACTIVE;
	session->data.operation = NDMP_DATA_OP_BACKUP;
	session->data.abortFlag = FALSE;

	/* Perform the dump. */
	err = (*session->data.module.startFunc)(&params);
	if (err != 0)
		ndmpdApiDone((void*)session, err);
	
	return(NDMP_NO_ERR);
}


/*
 * startRecover
 *
 * Parameters:
 *   session (input) - session pointer.
 *   bu_type   (input) - backup type.
 *   env_val   (input) - environment variable array.
 *   env_len   (input) - length of env_val.
 *
 * Returns:
 *   NDMP_NO_ERR - recover successfully started.
 *   otherwise   - error code of recover start error.
 */
static ndmp_error
startRecover(NdmpdSession*		session,
			 char*				bu_type,
			 ndmp_pval*			env_val,
			 u_long				env_len,
			 ndmp_name*			nlist_val,
			 u_long				nlist_len)
{
	ndmp_data_start_recover_reply	reply;

	NdmpdModuleParams				params;
	int								err;
	
	Debug(DBG_CAT_DATA|DBG_FOC_FLOW,
		  "startRecover: bu_type:%s\n",
		  bu_type);

	memset((void*)&reply, 0, sizeof(reply));
	
	if (session->data.state != NDMP_DATA_STATE_CONNECTED)
	{
		Error(LOG_ERR,
			  "startRecover: can't start new recover in current state.\n");
		return(NDMP_ILLEGAL_STATE_ERR);
	}
	
	if ((reply.error = ndmpdSaveEnv(session,
									env_val,
									env_len)) != NDMP_NO_ERR)
	{
		return(NDMP_NO_MEM_ERR);
	}

	if ((reply.error = ndmpdSaveNlist(session,
									  nlist_val,
									  nlist_len)) != NDMP_NO_ERR)
	{
		return(NDMP_NO_MEM_ERR);
	}

	reply.error = NDMP_NO_ERR;
	if (ndmpSendReply(session->connection, NDMP_NO_ERR, (void *)&reply) < 0)
	{
		Error(LOG_ERR,
			  "startRecover: error sending ndmp_data_start_recover_reply.\n");
		ndmpdDataError(session, NDMP_DATA_HALT_INTERNAL_ERROR);
		return(NDMP_NO_ERR);
	}

	/*
	 * Setup restore parameters.
	 */
	params.daemonCookie          = (void *)session;
	params.moduleCookie          = &session->data.module.moduleCookie;
	params.protocolVersion       = session->protocolVersion;
	params.operation             = NDMP_DATA_OP_RESTORE;
	params.getEnvFunc            = ndmpdApiGetEnv;
	params.addEnvFunc            = ndmpdApiAddEnv;
	params.getNameFunc           = ndmpdApiGetName;
	params.dispatchFunc          = ndmpdApiDispatch;
	params.doneFunc              = ndmpdApiDone;
	params.logFunc               = ndmpdApiLog;
	params.addFileHandlerFunc    = ndmpdApiAddFileHandler;
	params.removeFileHandlerFunc = ndmpdApiRemoveFileHandler;
	params.writeFunc             = 0;
	params.fileHistoryFileFunc   = 0;
	params.fileHistoryDirFunc    = 0;
	params.fileHistoryNodeFunc   = 0;
	params.readFunc              = ndmpdApiRead;
	params.seekFunc              = ndmpdApiSeek;
	params.fileRecoveredFunc     = ndmpdApiFileRecovered;
	params.stats                 = &session->data.module.stats;
	
	session->data.module.moduleCookie            = 0;
	session->data.module.startFunc               = simpleStart;
	session->data.module.abortFunc               = simpleAbort;
	session->data.module.stats.bytesProcessed    = 0;
	session->data.module.stats.estBytesRemaining = 0;
	session->data.module.stats.estTimeRemaining  = 0;
	session->data.readOffset                     = 0;
	session->data.readLength                     = 0;
	session->data.state                          = NDMP_DATA_STATE_ACTIVE;
	session->data.operation                      = NDMP_DATA_OP_RESTORE;
	session->data.abortFlag                      = FALSE;

	err = 0;
	
	/* Perform the restore. */
	err = (*session->data.module.startFunc)(&params);
	if (err != 0)
		ndmpdApiDone((void*)session, err);
	
	return(NDMP_NO_ERR);
}


/*
 * dataListen
 *   Creates a socket for listening for TCP/IP data connections
 *   initiated by a remote mover. Configures the server to listen
 *   and accept a connection.
 *
 * Parameters:
 *   session (input)  - session pointer.
 *   addr    (output) - location to store address of socket.
 *   port    (output) - location to store port of socket.
 *
 * Returns:
 *   0 - success.
 *  -1 - error.
 */
static int
dataListen(NdmpdSession*	session,
		   u_long			*addr,
		   u_short			*port)
{
	struct hostent*		hp;
	struct sockaddr_in	sin;
	struct utsname		uts;
	int					length;
	
	if (uname(&uts) < 0)
	{
		Error(LOG_ERR, "dataListen: uname error: %s\n",
			  strerror(errno));
		return(-1);
	}
	
	if ((hp = gethostbyname(uts.nodename)) == 0)
	{
		Error(LOG_ERR, "dataListen: unknown host: %s\n",
			  uts.nodename);
		return(-1);
	}

	*addr = ((struct in_addr*)(hp->h_addr))->s_addr;

	session->data.listenSock = socket(AF_INET, SOCK_STREAM, 0);
	if (session->data.listenSock < 0)
	{
		Error(LOG_ERR,
			  "dataListen: socket error: %s.\n",
			  strerror(errno));
		return(-1);
	}

	sin.sin_family      = AF_INET;
	sin.sin_addr.s_addr = INADDR_ANY;
	sin.sin_port        = 0;

	if (bind(session->data.listenSock,
			 (struct sockaddr *) &sin,
			 sizeof(sin)) < 0)
	{
		Error(LOG_ERR,
			  "dataListen: bind error: %s.\n",
			  strerror(errno));

		(void)close(session->data.listenSock);
		session->data.listenSock = -1;
		return(-1);
	}
		
	length = sizeof(sin);
	if (getsockname(session->data.listenSock,
					(struct sockaddr *) &sin,
					&length) < 0)
	{
		Error(LOG_ERR,
			  "dataListen: getsockname error: %s.\n",
			  strerror(errno));

		(void)close(session->data.listenSock);
		session->data.listenSock = -1;
		return(-1);
	}

	if (listen(session->data.listenSock, 5) < 0)
	{
		Error(LOG_ERR, "dataListen: listen error: %s.\n",
			  strerror(errno));

		(void)close(session->data.listenSock);
		session->data.listenSock = -1;
		return(-1);
	}

	/*
	 * Add a file handler for the listen socket.
	 * ndmpdSelect will call dataAcceptConnection when a
	 * connection is ready to be accepted.
	 */
	if (ndmpdAddFileHandler(session, (void*)session,
							session->data.listenSock,
							NDMPD_SELECT_MODE_READ,
							HC_MOVER,
							dataAcceptConnection) < 0)
	{
		(void)close(session->data.listenSock);
		session->data.listenSock = -1;
		return(-1);
	}
	
	*port = sin.sin_port;
	return(0);
}


/*
 * dataAcceptConnection
 *   Accept a data connection from a remote mover.
 *   Called by ndmpdSelect when a connection is pending on
 *   the data listen socket.
 *
 * Parameters:
 *   cookie  (input) - session pointer.
 *   fd      (input) - file descriptor.
 *   mode    (input) - select mode.
 *
 * Returns:
 *   void.
 */
static void
dataAcceptConnection(void*		cookie,
					 int		fd,
					 u_long		mode __attribute__ ((unused)))
{
	NdmpdSession*	session = (NdmpdSession*)cookie;

	struct sockaddr_in					from;
	int									from_len = sizeof(from);
	int									flags;
		
	Debug(DBG_CAT_DATA|DBG_FOC_FLOW,
		  "dataAcceptConnection\n");

	session->data.sock = accept(fd, (struct sockaddr *)&from, &from_len);

	(void)ndmpdRemoveFileHandler(session, fd);
	(void)close(session->data.listenSock);
	session->data.listenSock = -1;

	if (session->data.sock < 0)
	{
		Error(LOG_ERR, "dataAcceptConnection: accept error: %s.\n",
			  strerror(errno));
		ndmpdDataError(session, NDMP_DATA_HALT_CONNECT_ERROR);
		return;
	}

	/*
	 * Set the O_NDELAY flag on the socket to prevent
	 * reads and writes from blocking.
	 */
	if ((flags = fcntl(session->data.sock, F_GETFL)) < 0)
	{
		Error(LOG_ERR, "dataAcceptConnection: fcntl(F_GETFL) error: %s.\n",
			  strerror(errno));
		ndmpdDataError(session, NDMP_DATA_HALT_CONNECT_ERROR);
		return;
	}
		
	if ((flags = fcntl(session->data.sock,
					   F_SETFL, flags|O_NDELAY|O_NONBLOCK)) < 0)
	{
		Error(LOG_ERR, "dataAcceptConnection: fcntl(F_SETFL) error: %s.\n",
			  strerror(errno));
		ndmpdDataError(session, NDMP_DATA_HALT_CONNECT_ERROR);
		return;
	}

	
	Debug(DBG_CAT_DATA|DBG_FOC_FLOW,
		  "dataAcceptConnection: Received connection from %s\n",
		  inet_ntoa(from.sin_addr));

	session->data.state = NDMP_DATA_STATE_CONNECTED;
}


/*
 * dataReady
 *   File handler that is called when the data server side of
 *   of the data connection is ready for I/O.
 *
 * Parameters:
 *   cookie  (input) - session pointer.
 *   fd      (input) - file descriptor.
 *   mode    (input) - select mode.
 *
 * Returns:
 *   void.
 */
static void
dataReady(void*			cookie,
		  int			fd,
		  u_long		mode __attribute__ ((unused)))
{
	NdmpdSession*	session = (NdmpdSession*)cookie;

	Debug(DBG_CAT_MOVER|DBG_FOC_FLOW,
		  "dataReady.\n");
	
	session->data.ioReady = TRUE;
	(void)ndmpdRemoveFileHandler(session, fd);
}


/*
 * discardData
 *   Read and discard data from the data connection.
 *   Called when a module has called ndmpdSeek() prior to
 *   reading all of the data from the previous seek.
 *
 * Parameters:
 *   session (input) - session pointer.
 *
 * Returns:
 *   number of bytes read and discarded.
 *  -1 - error.
 */
static int
discardData(NdmpdSession*	session,
			u_long			length)
{
	int		fd;
	caddr_t	addr;
	int		n;
	
	if ((fd = open("/dev/zero", O_RDWR)) < 0)
	{
		Error(LOG_ERR,
			  "discardData: error opening /dev/zero: %s.\n",
			  strerror(errno));
		return(-1);
	}

	addr = mmap(0, length, PROT_WRITE, MAP_PRIVATE, fd, 0);
	if (addr == MAP_FAILED)
	{
		Error(LOG_ERR,
			  "discardData: error mapping /dev/zero: %s.\n",
			  strerror(errno));
		(void)close(fd);
		return(-1);
	}

	/* Read and discard the data. */
	n = read(session->data.sock, addr, length);
	if (n < 0)
	{
		Error(LOG_ERR,
			  "discardData: read error: %s.\n",
			  strerror(errno));
		(void)munmap(addr, length);
		(void)close(fd);
		return(-1);
	}
			
	(void)munmap(addr, length);
	(void)close(fd);
	return(n);
}