/*	$Id: zmodem.h,v 1.2 2001/10/25 23:56:29 efalk Exp $	*/#ifndef	ZMODEM_H#define	ZMODEM_H/* Master header file for Zmodem protocol driver routines */#if	0These routines are intended to be incorportated into other programs,and do not constitute a zmodem program by themselves, although ademo zmodem program that uses these routines has been included.All information pertaining to a transfer session is kept in a datastructure defined by the caller.  This makes it possible for thecaller to drive multiple simultaneous sessions.Caller provides I/O, timing and query routines.  Caller remainsin control at all times.  Typical use is to call these routinesfrom a select(2) loop.Overview:Transmit files:1 Init ZModem structure and open communications channel.2 Call ZmTInit() to begin protocol.3 Read characters from remote end and pass them to  ZmRcv() until ZmRcv() returns ZmDone or an error.4 Call ZmTFile() to begin transfer of a file.5 Read characters from remote end and pass them to  ZmRcv() until ZmRcv() returns ZmDone or an error.6 repeat steps 4&5 for all files.7 Call ZmTFinish() to indicate that all files have been  transfered.8 Read characters from remote end and pass them to  ZmRcv() until ZmRcv() returns ZmDone or an error.Receive files:1 Init ZModem structure and open communications channel.2 Call ZmRInit() to begin protocol.3 Read characters from remote end and pass them to  ZmRcv() until ZmRcv() returns ZmDone or an error.In detail:   1) Create a ZModem structure as defined below and fill it in.      'ifd', 'ofd' are the file descriptors used for input and output.	The interpretation of ifd and ofd is entirely up to the calling	routines, since the caller will be providing I/O functions.      'zrinitflags' is composed of the flags described below.	They describe the receive channel capabilities	and affect how the protocol will be carried out.	Define these to receive files.  When sending files, these	flags will be defined from the remote end.      'zsinitflags' is composed of the flags described below.	They describe the transmit channel capabilities	and affect how the protocol will be carried out.	Define these to send files.  When receiving files, these	flags will be defined from the remote end.      'attn': For transmit, this is the optional nul-terminated	attention string to be sent by the receiver to interrupt the	transmission.  For example, it might simply contain ^O to flush	the buffers, or it might interrupt the sending program.  Caller	needs to handle this interrupt properly and call ZmAttention().	For receive, this is the optional nul-terminated attention string	defined at the remote end.  Caller needs to provide a function that	can execute this sequence.      'timeout' is read-only, set by the zmodem package.  It is the	timeout value in seconds.  If this much time passes without	anything being received, caller should call the ZmTimeout()	function.  Note that timeout may be zero, in which case the	ZTimeout function should be called immediately if no characters	are ready to be received.      'packetsize' is set to the preferred data packet size.  Define	this when sending files.  Recommended length values are 256	bytes below 2400 bps, 512 at 2400 bps, and 1024 above 4800 bps	or when the data link is known to be relatively error free.	Ignored during receive.      'bufsize' is set to the size of the receive buffer size.  Define	this when receiving files.  When sending files, this will be	defined at the other end.      'windowsize' is used to prevent network connections from	buffering too many characters during transmit.  Setting	'windowsize' to nonzero causes zmodem to request status reports	from the receiver during transmit, and to pause if more than	this many bytes have been sent but not yet acknowledged.  Set	to zero to turn off windowing.  Ignored during receive.      Other fields are used to track the internal state of the zmodem      driver functions.     Since this is a source package, you are, of course, free to extend     the ZModem structure as you see fit.   2) Define the following functions:	int	ZXmitStr(u_char *str, int len, ZModem *info)		Transmit a buffer.  Return 0 on success, ZmErrSys on error.	void	ZIFlush(ZModem *info)		Flush all unread input on receive channel.  Do nothing if		this is not possible.	void	ZOFlush(ZModem *info)		Flush all buffered but not-yet-transmitted output		on transmit channel.  Do nothing if this is not possible.	int	ZAttn(ZModem *info)		Send attention signal defined in ZModem->attn.  Do		nothing if this field is NULL.  Otherwise, this field		is a nul-terminated character string to be		transmitted.  There are two special characters defined		below: ATTNBRK (0335) indicates that a BREAK signal		should be sent, and ATTNPSE (0336) represents a		1-second pause.	void	ZFlowControl(int onoff, ZModem *info)		Turn flow control on or off depending on the onoff flag.	void	ZStatus(int type, int value, char *status)		Called to provide status information.  Ignore or display		at your option.  Status string is not static, so copy		it if you need it beyond this call.  Type is defined		below under "ZStatus() types".	void *	ZOpenFile(char *name, u_long crc, ZModem *info, int write)		Called when receiving files, this function decides		whether or not to accept the specified file, and		if so, opens it for writing and returns the stdio		file handle.  If this function decides not to accept		the file, or cannot open the file, it returns NULL		and the remote sender is told to skip this file.		info->f0-f3 are the transfer flags, described below under		"ZFILE transfer flags".  These describe the type of		transfer desired (binary/ascii), and conditions for the		transfer, such as 'transfer if source newer or longer'.		info->len is the length of the file in bytes.  info->date is		the last modification date of the file, in seconds since		1-jan-1970.  info->mode is the unix file mode + 01000000, or		zero if not known.  info->filesRem and info->bytesRem are the		number of files and bytes remaining to be transferred		if known, zero otherwise.  'crc' is the file crc-32 value.		This is only provided if F1 contains ZMCRC.	int	ZWriteFile(u_char *buffer, int len, void *file, ZModem *info)		Write a buffer of data to the file.  Normally, you would		simply call fwrite(buffer, 1, len, file), but you may		want to translate line endings, etc.  File transfer		flags are available as info->f0,f1,f2,f3.		Return 0 on success, ZmErrSys on failure, with errno		describing the failure.	int	ZCloseFile(ZModem *info)		Close file after successful completion.  File modification		date and modes should be set at this time.		void	ZIdleStr(u_char *buffer, int len, ZModem *info)		Called to pass text that is received out-of-protocol.		This function may ignore or display this text at your		option.  3) Open the communications channel.	If possible, this should be a full-duplex channel with full	8-bit transmission.  Hardware flow control and/or XON/XOFF	flow control should be enabled.  4) Call these routines:	All functions return 0 on success, nonzero on failure.  See	"error code definitions", below.    Send:	int	ZmTInit(ZModem *info)		Begin a Zmodem transmit session.	int	ZmRcv(u_char *buffer, int len, ZModem *info)		Call whenever characters are received.  If this function		returns ZmDone, previous function has completed successfully,		either call ZmTFile() to start next file, or call		ZmTFinish() to terminate the session.	int	ZmTimeout(ZModem *info)		Call whenever the timeout period expires and no		characters have been received.	int	ZmAttention(ZModem *info)		Call whenever the attention sequence has been received		from the remote end.  It is safe to call this function		from an interrupt handler.	int	ZmTFile(char *filename, char *rfilename, 	  u_char f0,f1,f2,f3, int filesRem, int bytesRem, ZModem *info)		Begin transmitting a file.  If filename is not NULL,		then this function will open it.  Otherwise, info->file		must point to a stdio stream that is open for input.		It is preferable to provide the filename, so that		Zmodem can transmit file size and other information.		'rfilename' is the filename given to the remote end.		This may be the same as filename, the file part of		filename, or something else alltogether.  'rfilename'		must not be longer than the smallest data packet the		remote end might be willing to receive (about 200		characters).  f0-f3 are transfer flags, see "ZCBIN"		below.  'filesRem' and 'bytesRem' are the number of files		and bytes remaining to be transmitted, if known; zero if		not.		If 'filename' cannot be accessed, ZmTFile() returns		ZmErrCantOpen.  The link is still established, so you		need to either proceed with the next file or call		ZmTFinish().	int	ZmTFinish(ZModem *info)		Call after final file transfer has completed successfully.	int	ZmAbort(ZModem *info)		Call to abort transfer.  Physical connection remains		open until you close it.    Receive:	int	ZmRInit(ZModem *info)		Call to get ready to receive first file.  This function		will inform the sender that we are ready to receive.	int	ZmRcv(u_char *buffer, int len, ZModem *info)		Call whenever characters are received.  If this		function returns ZmDone, all file transfers have		completed successfully.	int	ZmTimeout(ZModem *info)		Call whenever the timeout period expires and no		characters have been received.	int	ZmAbort(ZModem *info)		Call to abort transfer.    Ymodem and Xmodem:	int YmodemTInit(ZModem *info)	int XmodemTInit(ZModem *info)	int YmodemRInit(ZModem *info)	int XmodemRInit(ZModem *info)		Same semantics as ZmTInit and ZmRInit.  It is		not normally necessary to call the Ymodem*Init() functions		as the Zmodem protocol will automatically switch to Ymodem		when needed.    Utility:	u_long	FileCrc(char *name)		Return CRC-32 of file.  5) Return Values:	ZmDone		Done.  Proceed with next file or ZmTFinish			(transmit) or exit (receive).	ZmErrInt	Internal error.  Link has been closed.	ZmErrSys	System error, see errno.  Link is closed.	ZmErrNotOpen	not used.	ZmFileTooLong	not used.	ZmFileCantWrite	not used.	ZmErrCantOpen	Can not open file, see errno.  Link is still open.	ZmErrInitTo	Transmitter failed to respond to init req.  Link closed.	ZmErrSequence	Packet received out of sequence.  Link is closed.	ZmErrCancel	Cancelled by remote end.  Link is closed.	ZmErrRcvTo	Remote end timed out during transfer.  Link is closed.	ZmErrSndTo	Remote end timed out during transfer.  Link is closed.	ZmErrCmdTo	Remote end timed out during transfer.  Link is closed.	Note that "link is closed" means that the remote end is (presumably)	no longer operating.  The actual communications channel is not	closed unless you close it.  "Link is still open" means that the	remote end is still ready to receive the next file.#endif	/* PARAMETERS	 *	 * The following #defines control the behavior of the Zmodem	 * package.  Note that these may be replaced with variables	 * if you like.  For example, "#define DoInitRZ" may be replaced	 * with "extern int DoInitRz" to use a global variable, or with	 * "#define DoInitRZ (info->doInitRz)" to use a variable you	 * add to the ZModem structure.	 *	 * It is assumed that the compiler is good enough to optimize	 * "if( 0 )" and "if( 1 )" cases.  If not, you may wish to modify	 * the source code to use #ifdef instead.	 */#define	DoInitRZ	1	/* send initial "rz\r" when transmitting */#define	AllowCommand	0	/* allow remote end to execute commands */#define	SendSample	1	/* sender can sample reverse channel */#define	SendAttn	1	/* sender can be interrupted with Attn signal */#define	ResponseTime	10	/* reasonable response time for sender to				 * respond to requests from receiver */#define	SerialNo	1	/* receiver serial # */#define	MaxNoise	64	/* max "noise" characters before transmission				 * pauses */#define	MaxErrs	  1000000	/* Max receive errors before cancel *//* original value equal 20 */#define	AlwaysSinit	1	/* always send ZSINIT header, even if not				 * needed, this makes protocol more robust */#define SendOnly	0	/* compiles smaller version for send only */#define RcvOnly		0	/* compiles smaller version for receive only */	/* Internal State */typedef enum zmstate {  /* receive */  RStart,			/* sent RINIT, waiting for ZFILE or SINIT */  RSinitWait,			/* got SINIT, waiting for data */  RFileName,			/* got ZFILE, waiting for filename & info */  RCrc,				/* got filename, want crc too */  RFile,			/* got filename, ready to read */  RData,			/* reading data */  RDataErr,			/* encountered error, ignoring input */  RFinish,			/* sent ZFIN, waiting for 'OO' */  /* transmit */  TStart,			/* waiting for INIT frame from other end */  TInit,			/* received INIT, sent INIT, waiting for ZACK */  FileWait,			/* sent file header, waiting for ZRPOS */  CrcWait,			/* sent file crc, waiting for ZRPOS */  Sending,			/* sending data subpackets, ready for int */  SendWait,			/* waiting for ZACK */  SendDone,			/* file finished, need to send EOF */  SendEof,			/* sent EOF, waiting for ZACK */  TFinish,			/* sent ZFIN, waiting for ZFIN */  /* general */  CommandData,			/* waiting for command data */  CommandWait,			/* waiting for command to execute */  StderrData,			/* waiting for stderr data */  Done,  /* x/ymodem transmit */  YTStart,			/* waiting for 'G', 'C' or NAK */  YTFile,			/* sent filename, waiting for ACK */  YTDataWait,			/* ready to send data, waiting for 'C' */  YTData,			/* sent data, waiting for ACK */  YTEOF,			/* sent eof, waiting for ACK */  YTFin,			/* sent null filename, waiting for ACK */  /* x/ymodem receive */  YRStart,			/* sent 'C', waiting for filename */  YRDataWait,			/* received filename, waiting for data */  YRData,			/* receiving filename or data */  YREOF				/* received first EOT, waiting for 2nd */} ZMState ;typedef enum zminputstate{