usb-darwin.c   [plain text]

/*
 "$Id: usb-darwin.c,v 1.13.2.3 2005/12/20 21:05:06 jlovell Exp $"

© Copyright 2005 Apple Computer, Inc. All rights reserved.

IMPORTANT:  This Apple software is supplied to you by Apple Computer,
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redistribute this Apple software.

In consideration of your agreement to abide by the following terms, and
subject to these terms, Apple grants you a personal, non-exclusive
license, under AppleÕs copyrights in this original Apple software (the
"Apple Software"), to use, reproduce, modify and redistribute the Apple
Software, with or without modifications, in source and/or binary forms;
provided that if you redistribute the Apple Software in its entirety and
without modifications, you must retain this notice and the following
text and disclaimers in all such redistributions of the Apple Software. 
Neither the name, trademarks, service marks or logos of Apple Computer,
Inc. may be used to endorse or promote products derived from the Apple
Software without specific prior written permission from Apple.  Except
as expressly stated in this notice, no other rights or licenses, express
or implied, are granted by Apple herein, including but not limited to
any patent rights that may be infringed by your derivative works or by
other works in which the Apple Software may be incorporated.

The Apple Software is provided by Apple on an "AS IS" basis.  APPLE
MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND
OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.

IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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  */

/*
*   USB port on Darwin backend for the Common UNIX Printing System (CUPS).
*
*
* Contents:
*
*   main()         - Send a file to the specified USB port.
*   list_devices() - List all USB devices.
*/

#include <CoreFoundation/CoreFoundation.h>
#include <ApplicationServices/ApplicationServices.h>

#include <IOKit/usb/IOUSBLib.h>
#include <IOKit/IOCFPlugIn.h>
#include <mach/mach.h>	
#include <mach/mach_error.h>
#include <mach/mach_time.h>

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#include <termios.h>
#include <unistd.h>
#include <pthread.h>	// Used for writegReadMutex
#include <sys/sysctl.h>
#include <libgen.h>


#ifndef kPMPrinterURI
#define	kPMPrinterURI					CFSTR("Printer URI")
#endif

// Panther/10.3 kIOUSBInterfaceInterfaceID190
// Jaguar/10.2 kIOUSBInterfaceInterfaceID182
#define		USB_INTERFACE_KIND 					CFUUIDGetUUIDBytes(kIOUSBInterfaceInterfaceID190)
#define     kUSBLanguageEnglish            		0x409

/*
**	Section 5.3 USB Printing Class spec
*/
#define		kUSBPrintingSubclass				1
#define		kUSBPrintingProtocolNoOpen			0
#define		kUSBPrintingProtocolUnidirectional	1
#define		kUSBPrintingProtocolBidirectional	2

#define 	kUSBPrintClassGetDeviceID			0
#define		kUSBPrintClassGetCentronicsStatus	1
#define		kUSBPrintClassSoftReset				2

/*
**	Apple MacOS X printer-class plugins
*/
#define 	kUSBPrinterClassTypeID				(CFUUIDGetConstantUUIDWithBytes(NULL, 0x06, 0x04, 0x7D, 0x16, 0x53, 0xA2, 0x11, 0xD6, 0x92, 0x06, 0x00, 0x30, 0x65, 0x52, 0x45, 0x92))

#define		kUSBPrinterClassInterfaceID			(CFUUIDGetConstantUUIDWithBytes(NULL, 0x03, 0x34, 0x6D, 0x74, 0x53, 0xA3, 0x11, 0xD6, 0x9E, 0xA1, 0x76, 0x30, 0x65, 0x52, 0x45, 0x92))

#define 	kUSBGenericPrinterClassDriver		CFSTR( "/System/Library/Printers/Libraries/USBGenericPrintingClass.plugin" )
#define 	kUSBGenericTOPrinterClassDriver		CFSTR( "/System/Library/Printers/Libraries/USBGenericTOPrintingClass.plugin" )

#define		kUSBClassDriverProperty				CFSTR( "USB Printing Class" )
#define		kUSBPrinterClassDeviceNotOpen		-9664	/*kPMInvalidIOMContext*/

typedef union {
	char			b;
	struct {
		unsigned	reserved0:2;
		unsigned	paperError:1;
		unsigned	select:1;
		unsigned	notError:1;
		unsigned	reserved1:3;
	} status;
} CentronicsStatusByte;

typedef struct
{
    CFStringRef		manufacturer;	// manufacturer name
    CFStringRef		product;		// product name
    CFStringRef		compatible;		// compatible product name
    CFStringRef		serial;			// serial number
    CFStringRef		command;		// command set
    CFStringRef		ppdURL;			// url of the selected PPD, if any
} USBPrinterAddress;

typedef IOUSBInterfaceInterface190	**USBPrinterInterface;

typedef struct 
{
	UInt8		requestType;
	UInt8		request;
	UInt16		value;
	UInt16		index;
	UInt16		length;
	void		*buffer;	
} USBIODeviceRequest;

typedef struct classDriverContext
{
    IUNKNOWN_C_GUTS;
    CFPlugInRef				plugin;				// release plugin
    IUnknownVTbl			**factory;	
    void					*vendorReference;	// vendor class specific usage
    UInt32					location;			// unique location in bus topology
    UInt8					interfaceNumber;
    UInt16					vendorID;
    UInt16					productID;
    USBPrinterInterface		interface;			// identify the device to IOKit
    UInt8		  			outpipe;			// mandatory bulkOut pipe
    UInt8					inpipe;				// optional bulkIn pipe   
    /*
    **	general class requests
    */
    kern_return_t 	(*DeviceRequest)( struct classDriverContext **printer, USBIODeviceRequest *iorequest, UInt16 timeout );
    kern_return_t	(*GetString)( struct classDriverContext **printer, UInt8 whichString, UInt16 language, UInt16 timeout, CFStringRef *result );
    /*
    **	standard printer class requests
    */
    kern_return_t	(*SoftReset)( struct classDriverContext **printer, UInt16 timeout );
    kern_return_t	(*GetCentronicsStatus)( struct classDriverContext **printer, CentronicsStatusByte *result, UInt16 timeout );
    kern_return_t	(*GetDeviceID)( struct classDriverContext **printer, CFStringRef *devid, UInt16 timeout );
    /*
    **	standard bulk device requests
    */
    kern_return_t 	(*ReadPipe)( struct classDriverContext **printer, UInt8 *buffer, UInt32 *count );
    kern_return_t 	(*WritePipe)( struct classDriverContext **printer, UInt8 *buffer, UInt32 *count, Boolean eoj );
    /*
    **	interface requests
    */
    kern_return_t 	(*Open)( struct classDriverContext **printer, UInt32 location, UInt8 protocol );
    kern_return_t 	(*Abort)( struct classDriverContext **printer );
    kern_return_t 	(*Close)( struct classDriverContext **printer );
    /*
    **	initialize and terminate
    */
    kern_return_t 	(*Initialize)( struct classDriverContext **printer, struct classDriverContext **baseclass );
    kern_return_t 	(*Terminate)( struct classDriverContext **printer );
} USBPrinterClassContext;


typedef struct usbPrinterClassType
{
	USBPrinterClassContext	*classdriver;
	CFUUIDRef				factoryID;
	UInt32					refCount;
} USBPrinterClassType;


/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        Constants
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/

/*
    Debugging output to Console
    DEBUG undefined or
    DEBUG=0		production code: suppress console output

    DEBUG=1		report errors (non-zero results)
    DEBUG=2		report all results, generate dumps
*/
#if DEBUG==2
#define DEBUG_ERR(c, x)						showint(x, c)
#define DEBUG_DUMP( text, buf, len )		dump( text, buf, len )
#define DEBUG_CFString( text, a )			showcfstring( text, a )
#define DEBUG_CFCompareString( text, a, b )	cmpcfs( text, a, b )
#elif DEBUG==1
#define DEBUG_ERR(c, x)						if (c) fprintf(stderr, x, c)
#define DEBUG_DUMP( text, buf, len )
#define DEBUG_CFString( text, a )
#define DEBUG_CFCompareString( text, a, b )
#else
#define DEBUG_ERR(c, x)
#define DEBUG_DUMP( text, buf, len )
#define DEBUG_CFString( text, a )
#define DEBUG_CFCompareString( text, a, b )
#endif

/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        Type Definitions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/

typedef struct
{
    //
    //	Tagged/Tranparent Binary Communications Protocol
    //	TBCP read
    Boolean					tbcpQuoteReads;			// enable tbcp on reads
    Boolean					escapeNextRead;			// last char of last read buffer was escape
    UInt8					*tbcpReadData;			// read buffer
    UInt32					readLength;				// read buffer length (all used)
    int						match_endoffset,		// partial match of end TBCP sequence
                            match_startoffset;		// partial match of start TBCP sequence
    // TBCP write
    UInt8					*tbcpWriteData;			// write buffer
    UInt32					tbcpBufferLength,		// write buffer allocated length
                            tbcpBufferRemaining;	// write buffer not used

    Boolean					sendStatusNextWrite;

} PostScriptData;

typedef struct 
{
    CFPlugInRef				plugin;			// valid until plugin is release 
    USBPrinterClassContext	**classdriver;	// usb printer class in user space
    CFStringRef				bundle;			// class driver URI
    UInt32					location;		// unique location in USB topology
    USBPrinterAddress		address;		// topology independent bus address
    CFURLRef				reference;		// internal use
    int				classdrivererror;	// result of trying to load class driver
} USBPrinterInfo;

/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        Functions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/

/*
**	IOKit to CF functions
*/
USBPrinterInfo		*UsbCopyPrinter( USBPrinterInfo *aPrinter );
CFMutableArrayRef	UsbGetAllPrinters( void );
void				UsbReleasePrinter( USBPrinterInfo *aPrinter );
void				UsbReleaseAllPrinters( CFMutableArrayRef printers );
kern_return_t		UsbRegistryOpen( USBPrinterAddress *usbAddress, USBPrinterInfo **result );
kern_return_t		UsbUnloadClassDriver( USBPrinterInfo *printer );
kern_return_t		UsbLoadClassDriver( USBPrinterInfo *printer, CFUUIDRef interfaceID, CFStringRef classDriverBundle );
CFStringRef			UsbMakeFullUriAddress( USBPrinterInfo *aPrinter );

int			UsbSamePrinter( const USBPrinterAddress *lastTime, const USBPrinterAddress *thisTime ); 

OSStatus	UsbGetPrinterAddress( USBPrinterInfo *thePrinter, USBPrinterAddress *address, UInt16 timeout );

static void setupCFLanguage(void);

#if defined(__i386__)
static pid_t child_pid;						/* Child PID */
static void run_ppc_backend(int argc, char *argv[], int fd);	/* Starts child backend process running as a ppc executable */
static void sigterm_handler(int sig);				/* SIGTERM handler */
#endif /* __i386__ */

/*******************************************************************************
	Contains:	Support IEEE-1284 DeviceID as a CFString.

	Copyright 2000-2005 by Apple Computer, Inc., all rights reserved.

	Description:
		IEEE-1284 Device ID is referenced in USB and PPDT (1394.3). It allows
		a computer peripheral to convey information about its required software
		to the host system.
		
		DeviceID is defined as a stream of ASCII bytes, commencing with one 16-bit
		binary integer in Little-Endian format which describes how many bytes
		of data are required by the entire DeviceID.
		
		The stream of bytes is further characterized as a series of
		key-value list pairs. In other words each key can be followed by one
		or more values. Multiple key-value list pairs fill out the DeviceID stream.
		
		Some keys are required: COMMAND SET (or CMD), MANUFACTURER (or MFG),
		and MODEL (or MDL).
		
		One needs to read the first two bytes of DeviceID to allocate storage
		for the complete DeviceID string. Then a second read operation can
		retrieve the entire string.
		
		Often DeviceID is not very large. By allocating a reasonable buffer one
		can fetch most device's DeviceID string on the first read.
	
	A more formal definition of DeviceID.

		<DeviceID> = <Length><Key_ValueList_Pair>+

		<Length> = <low byte of 16 bit integer><high byte of 16 bit integer>
		<Key_ValueList_Pair> = <Key>:<Value>[,<Value>]*;

		<Key> = <ASCII Byte>+
		<Value> = <ASCII Byte>+
		
		Some keys are defined in the standard. The standard specifies that
		keys are case sensitive. White space is allowed in the key.
		
		The standard does not say that values are case-sensitive.
		Lexmark is known to ship printers with mixed-case value:
			i.e., 'CLASS:Printer'

		Required Keys:
			'COMMAND SET' or CMD
			MANUFACTURER or MFG
			MODEL or MDL
		
		Optional Keys:
			CLASS
				Value PRINTER is referenced in the standard.
				
		Observed Keys:
			SN,SERN
				Used by Hewlett-Packard for the serial number.
		
		
*******************************************************************************/

/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	Pragmas
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/


/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	Constants
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
#define kDeviceIDKeyCommand				CFSTR("COMMAND SET:")
#define kDeviceIDKeyCommandAbbrev		CFSTR( "CMD:" )

#define kDeviceIDKeyManufacturer  		CFSTR("MANUFACTURER:")
#define kDeviceIDKeyManufacturerAbbrev  CFSTR( "MFG:" )

#define kDeviceIDKeyModel  				CFSTR("MODEL:")
#define kDeviceIDKeyModelAbbrev  		CFSTR( "MDL:" )

#define kDeviceIDKeySerial				CFSTR("SN:")
#define kDeviceIDKeySerialAbbrev  		CFSTR("SERN:")

#define kDeviceIDKeyCompatible  		CFSTR("COMPATIBLITY ID:")
#define kDeviceIDKeyCompatibleAbbrev	CFSTR("CID:")

// delimiters
#define kDeviceIDKeyValuePairDelimiter  CFSTR(";")

/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	Type definitions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/

/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	Function prototypes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/

static CFStringRef CreateEncodedCFString(CFStringRef string);
static CFRange	DelimitSubstring( CFStringRef stringToSearch, CFStringRef delim, CFRange bounds, CFStringCompareFlags options );
static void parseOptions(const char *options, char *serial, UInt32 *location);

CFStringRef
DeviceIDCreateValueList(	const CFStringRef deviceID,
							const CFStringRef abbrevKey,
							const CFStringRef key );

static int addPercentEscapes(const unsigned char* src, char* dst, int dstMax);
static int removePercentEscapes(const char* src, unsigned char* dst, int dstMax);

/* Required to suppress redefinition warnings for these two symbols 
*/
#if defined(TCP_NODELAY)
#undef TCP_NODELAY
#endif
#if defined(TCP_MAXSEG)
#undef TCP_MAXSEG
#endif

#include <cups/cups.h>


#define PRINTER_POLLING_INTERVAL		5	/* seconds */
#define INITIAL_LOG_INTERVAL			(PRINTER_POLLING_INTERVAL)
#define SUBSEQUENT_LOG_INTERVAL			(3*INITIAL_LOG_INTERVAL)

// WAITEOF_DELAY is number of seconds we'll wait for responses from the printer
//	after we've finished sending all the data
#define WAITEOF_DELAY			7

#define USB_MAX_STR_SIZE		1024


static volatile int done = 0;
static int gWaitEOF = false;
static int gBidi = true;
static pthread_cond_t *gReadCompleteConditionPtr = NULL;
static pthread_mutex_t *gReadMutexPtr = NULL;



#if DEBUG==2  

static char
hexdigit( char c )
{
    return ( c < 0 || c > 15 )? '?': (c < 10)? c + '0': c - 10 + 'A';
}

static char
asciidigit( char c )
{
    return (c< 20 || c > 0x7E)? '.': c;
}

void
dump( char *text, void *s, int len )
{
    int i;
    char *p = (char *) s;
    char m[1+2*16+1+16+1];

    fprintf(stderr, "%s pointer %x len %d\n", text, (unsigned int) p, len );

    for ( ; len > 0; len -= 16 )
    {
        char *q = p;
        char *out = m;
        *out++ = '\t';
        for ( i = 0; i < 16 && i < len; ++i, ++p )
        {
            *out++ = hexdigit( (*p >> 4) & 0x0F );
                                 *out++ = hexdigit( *p & 0x0F );
        }
        for ( ;i < 16; ++i )
        {
            *out++ = ' ';
            *out++ = ' ';
        }
        *out++ = '\t';
        for ( i = 0; i < 16 && i < len; ++i, ++q )
            *out++ = asciidigit( *q );
        *out = 0;
        m[ strlen( m ) ] = '\0';
        fprintf(stderr,  "%s\n", m );
    }
}

void 
printcfs( char *text, CFStringRef s )
{
    char dest[1024];
    if ( s != NULL )
    {
        if ( CFStringGetCString(s, dest, sizeof(dest), kCFStringEncodingUTF8) )
            sprintf( dest,  "%s <%s>\n", text, dest );
        else
            sprintf( dest,  "%s [Unknown string]\n", text );
    } else {
       sprintf( dest,  "%s [NULL]\n", text );
    }
	perror( dest );
}

void
cmpcfs( char *text, CFStringRef a, CFStringRef b )
{
    CFRange found = {0, 0};
    
    printcfs( text, a );
    printcfs( " ", b );

    if (a != NULL && b != NULL) {
        found = CFStringFind( a, b, kCFCompareCaseInsensitive );
	
    } else if (a == NULL && b == NULL) {
        found.length = 1;	// Match
        found.location = 0;
    } else {
        found.length = 0;	// No match.
    }
    
    if ( found.length > 0 )
        fprintf(stderr,  "matched @%d:%d\n", (int) found.location, (int) found.length);
    else
        fprintf(stderr,  "not matched\n" );
}
#endif //DEBUG==2

#ifdef PARSE_PS_ERRORS
static const char *nextLine (const char *buffer);
static void parsePSError (char *sockBuffer, int len);


static const char *nextLine (const char *buffer)
{
	const char *cptr, *lptr = NULL;
	for (cptr = buffer; *cptr && lptr == NULL; cptr++)
		if (*cptr == '\n' || *cptr == '\r')
			lptr = cptr;
	return lptr;
}

static void parsePSError (char *sockBuffer, int len)
{
	static char  gErrorBuffer[1024] = "";
	static char *gErrorBufferPtr = gErrorBuffer;
	static char *gErrorBufferEndPtr = gErrorBuffer + sizeof(gErrorBuffer);

	char *pCommentBegin, *pCommentEnd, *pLineEnd;
	char *logLevel;
	char logstr[1024];
	int  logstrlen;

	if (gErrorBufferPtr + len > gErrorBufferEndPtr - 1)
		gErrorBufferPtr = gErrorBuffer;
	if (len > sizeof(gErrorBuffer) - 1)
		len = sizeof(gErrorBuffer) - 1;

	memcpy(gErrorBufferPtr, (const void *)sockBuffer, len);
	gErrorBufferPtr += len;
	*(gErrorBufferPtr + 1) = '\0';


	pLineEnd = (char *)nextLine((const char *)gErrorBuffer);
	while (pLineEnd != NULL)
	{
		*pLineEnd++ = '\0';

		pCommentBegin = strstr(gErrorBuffer,"%%[");
		pCommentEnd = strstr(gErrorBuffer, "]%%");
		if (pCommentBegin != gErrorBuffer && pCommentEnd != NULL)
		{
			pCommentEnd += 3;            /* Skip past "]%%" */
			*pCommentEnd = '\0';         /* There's always room for the nul */

			if (strncasecmp(pCommentBegin, "%%[ Error:", 10) == 0)
				logLevel = "DEBUG";
			else if (strncasecmp(pCommentBegin, "%%[ Flushing", 12) == 0)
				logLevel = "DEBUG";
			else
				logLevel = "INFO";
			
			if ((logstrlen = snprintf(logstr, sizeof(logstr), "%s: %s\n", logLevel, pCommentBegin)) >= sizeof(logstr))
			{
				/* If the string was trucnated make sure it has a linefeed before the nul */
				logstrlen = sizeof(logstr) - 1;
				logstr[logstrlen - 1] = '\n';
			}
			write(STDERR_FILENO, logstr, logstrlen);
		}

		// move everything over...
		strcpy(gErrorBuffer, pLineEnd);
		gErrorBufferPtr = gErrorBuffer;
		pLineEnd = (char *)nextLine((const char *)gErrorBuffer);
	}
}
#endif // PARSE_PS_ERRORS

void *
readthread( void *reference )
{
	/*
	**	post a read to the device and write results to stdout
	**	the final pending read will be Aborted in the main thread
	*/
	UInt8					readbuffer[512];
	UInt32					rbytes;
	kern_return_t			readstatus;
	USBPrinterClassContext	**classdriver = (USBPrinterClassContext	**) reference;


	struct mach_timebase_info	timeBaseInfo;
	uint64_t					start,
								delay;

   /*
	* Calculate what 250 milliSeconds are in mach absolute time...
	*/

	mach_timebase_info(&timeBaseInfo);
	delay = ((uint64_t)250000000 * (uint64_t)timeBaseInfo.denom) / (uint64_t)timeBaseInfo.numer;

	do
	{
	   /*
		* Remember when we started so we can throttle the loop after the read call...
		*/

		start = mach_absolute_time();

		rbytes = sizeof(readbuffer) - 1;
		readstatus = (*classdriver)->ReadPipe( classdriver, readbuffer, &rbytes );
		if ( kIOReturnSuccess == readstatus && rbytes > 0 )
		{
			write( STDOUT_FILENO, readbuffer, rbytes );
			/* cntrl-d is echoed by the printer.
			* NOTES: 
			*   Xerox Phaser 6250D doesn't echo the cntrl-d.
			*   Xerox Phaser 6250D doesn't always send the product query.
			*/
			if (gWaitEOF && readbuffer[rbytes-1] == 0x4)
				break;
#ifdef PARSE_PS_ERRORS
			parsePSError(readbuffer, rbytes);
#endif
		}

	   /*
		* Make sure this loop executes no more than once every 250 miliseconds...
		*/

		if ((readstatus != kIOReturnSuccess || rbytes == 0) && (gWaitEOF || !done))
			mach_wait_until(start + delay);

	} while ( gWaitEOF || !done );	// Abort from main thread tests error here

	/* Let the other thread (main thread) know that we have
	* completed the read thread...
	*/
	pthread_mutex_lock(gReadMutexPtr);
    pthread_cond_signal(gReadCompleteConditionPtr);
	pthread_mutex_unlock(gReadMutexPtr);

	return NULL;
}

/*
* 'print_device()' - Send a file to the specified USB port.
*/
int print_device(const char *uri, const char *hostname, const char *resource, const char *options, int fd, int copies, int argc, char *argv[])
{
	UInt32		wbytes,			/* Number of bytes written */
				buffersize = 2048;
	ssize_t		nbytes;			/* Number of bytes read */
	off_t		tbytes;			/* Total number of bytes written */
	char		*buffer,		/* Output buffer */
				*bufptr;		/* Pointer into buffer */

   pthread_cond_t   readCompleteCondition;
   pthread_mutex_t  readMutex;
   pthread_t		thr;
   int				thread_created = 0;

    USBPrinterInfo		*targetPrinter = NULL;
    USBPrinterInfo		*potentialPrinter = NULL;
    CFMutableArrayRef	usbPrinters;
	char				manufacturer_buf[USB_MAX_STR_SIZE],
						product_buf[USB_MAX_STR_SIZE],
						serial_buf[USB_MAX_STR_SIZE];
	CFStringRef			manufacturer;
	CFStringRef			product;
	CFStringRef			serial;
	UInt32				location = 0;
	OSStatus			status = noErr;


	#if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
		struct sigaction action;	/* Actions for POSIX signals */
	#endif /* HAVE_SIGACTION && !HAVE_SIGSET */

	setupCFLanguage();
	fprintf(stderr, "INFO: Opening connection\n");

	parseOptions(options, serial_buf, &location);

	if (resource[0] == '/')
	  resource++;

	removePercentEscapes(hostname,	(unsigned char*)manufacturer_buf,	sizeof(manufacturer_buf));
	removePercentEscapes(resource,	(unsigned char*)product_buf,		sizeof(product_buf));

	manufacturer = CFStringCreateWithCString(NULL, manufacturer_buf, kCFStringEncodingUTF8);
	product	     = CFStringCreateWithCString(NULL, product_buf,		 kCFStringEncodingUTF8);
	serial	     = CFStringCreateWithCString(NULL, serial_buf,		 kCFStringEncodingUTF8);

	USBPrinterInfo			*activePrinter = NULL;
	USBPrinterClassContext	**classdriver;
	int						countdown = INITIAL_LOG_INTERVAL;
	do
	{
		//
		//	given a manufacturer and product, bind to a specific printer on the bus
		//
		usbPrinters = UsbGetAllPrinters();
		//
		//	if we have at least one element of the URI, find a printer module that matches
		//
		if ( NULL != usbPrinters && (manufacturer || product ) )
		{
			int i,
				numPrinters =  CFArrayGetCount(usbPrinters);
			for ( i = 0; i < numPrinters; ++i ) 
			{
				int				match = FALSE;
				USBPrinterInfo	*printer = (USBPrinterInfo *) CFArrayGetValueAtIndex( usbPrinters, i );
				if ( printer )
				{
					match = printer->address.manufacturer && manufacturer? CFEqual(printer->address.manufacturer, manufacturer ): FALSE;
					if ( match )
					{
						match = printer->address.product && product? CFEqual(printer->address.product, product ): FALSE;
					}
					if ( match )
					{
						if (serial != NULL && CFStringGetLength(serial))  
						{
							// Note with old queues (pre Panther) the CUPS uri may have no serial number (serial==NULL).
							//	In this case, we will ignore serial number (as before), and we'll match to the first
							//	printer that agrees with manufacturer and product.
							// If the CUPS uri does include a serial number, we'll enter this clause
							//	which requires the printer's serial number to match the CUPS serial number.
							// The net effect is that for printers with a serial number,
							//	new queues must match the serial number, while old queues match any printer 
							//	that satisfies the manufacturer/product match.
							//
							match = printer->address.serial? CFEqual(printer->address.serial, serial ): FALSE;
						}
						else if (location != 0 && printer->location != 0)
						{
							match = (printer->location == location);
							if (!match && potentialPrinter == NULL)
								potentialPrinter = UsbCopyPrinter( printer );
						}
					}

					if ( match )
					{
						targetPrinter = UsbCopyPrinter( printer );
						break;	// for, compare partial address to address for each printer on usb bus
					}
				}
			}
			
			if (potentialPrinter != nil)
			{
				if (targetPrinter == nil)
					targetPrinter = potentialPrinter;
				else
					UsbReleasePrinter(potentialPrinter);
				
				potentialPrinter = nil;
			}
				
		}
		UsbReleaseAllPrinters( usbPrinters );
		if ( NULL != targetPrinter )
		{
#if defined(__i386__)
			/*
			 * If we were unable to load the class drivers for this printer it's probably because they're ppc-only.
			 * In this case try to fork & exec this backend as a ppc executable so we can use them...
			 */
			if (targetPrinter->classdrivererror)	// kPMInvalidIOMContext when loading ppc class drivers
			{
				run_ppc_backend(argc, argv, fd);
				/* Never returns here */
			}
#endif /* __i386__ */

			status = UsbRegistryOpen( &targetPrinter->address, &activePrinter );
		}

		if ( NULL == activePrinter )
		{
			sleep( PRINTER_POLLING_INTERVAL );
			countdown -= PRINTER_POLLING_INTERVAL;
			if ( !countdown )
			{
				// periodically, write to the log so someone knows we're waiting
				if (NULL == targetPrinter)
					fprintf(stderr, "WARNING: Printer not responding\n" );
				else
					fprintf(stderr, "INFO: Printer busy\n" );
				countdown = SUBSEQUENT_LOG_INTERVAL;	// subsequent log entries, every 30 minutes
			}
		}
	} while ( NULL == activePrinter );

	classdriver = activePrinter->classdriver;
	if ( NULL == classdriver )
	{
		perror("ERROR: Unable to open USB Printing Class port");
		return (status);
	}
	
	/*
	* Now that we are "connected" to the port, ignore SIGTERM so that we
	* can finish out any page data the driver sends (e.g. to eject the
	* current page...  Only ignore SIGTERM if we are printing data from
	* stdin (otherwise you can't cancel raw jobs...)
	*/
	
	if (!fd)
	{
#ifdef HAVE_SIGSET /* Use System V signals over POSIX to avoid bugs */
		sigset(SIGTERM, SIG_IGN);
#elif defined(HAVE_SIGACTION)
		memset(&action, 0, sizeof(action));
		
		sigemptyset(&action.sa_mask);
		action.sa_handler = SIG_IGN;
		sigaction(SIGTERM, &action, NULL);
#else
		signal(SIGTERM, SIG_IGN);
#endif /* HAVE_SIGSET */
	}

	buffer = malloc( buffersize );
	if ( !buffer ) {
		fprintf(stderr, "ERROR: Couldn't allocate internal buffer\n" );
		status = -1;
	}
	else
	{
		if (gBidi)
		{
		    if (pthread_cond_init(&readCompleteCondition, NULL) == 0)
		    {
			    gReadCompleteConditionPtr = &readCompleteCondition;
			    
			    if (pthread_mutex_init(&readMutex, NULL) == 0)
			    {
				    gReadMutexPtr = &readMutex;
    
				    if (pthread_create(&thr, NULL, readthread, classdriver ) > 0)
					    fprintf(stderr, "WARNING: Couldn't create read channel\n");
				    else
					    thread_created = 1;
			    }
		    }
		}
	}
	/*
	* the main thread sends the print file...
	*/

	fprintf(stderr, "INFO: Sending data\n");

	while (noErr == status && copies > 0)
	{
		copies --;
		if (STDIN_FILENO != fd)
		{
			fputs("PAGE: 1 1", stderr);
			lseek( fd, 0, SEEK_SET );   // rewind
		}

		tbytes = 0;
		while (noErr == status && (nbytes = read(fd, buffer, buffersize)) > 0)
		{
			/*
			* Write the print data to the printer...
			*/

			tbytes += nbytes;
			bufptr = buffer;

			while (nbytes > 0 && noErr == status )
			{
				wbytes = nbytes;
				status = (*classdriver)->WritePipe( classdriver, (UInt8*)bufptr, &wbytes, 0 /*nbytes > wbytes? 0: feof(fp)*/ );
				if (wbytes < 0 || noErr != status)
				{
					OSStatus err;
					err = (*classdriver)->Abort( classdriver );
					fprintf(stderr, "ERROR: %ld: Unable to send print file to printer (canceled %ld)\n", status, err );
					break;
				}

				nbytes -= wbytes;
				bufptr += wbytes;
			}

			if (fd != 0 && noErr == status)
				fprintf(stderr, "DEBUG: Sending print file, %qd bytes...\n", (off_t)tbytes);
		}
	}
	done = 1;	// stop scheduling reads

	if ( thread_created )
	{
		/* Give the read thread WAITEOF_DELAY seconds to complete all the data. If
		* we are not signaled in that time then force the thread to exit by setting
		* the waiteof to be false. Plese note that this relies on us using the timeout
		* class driver.
		*/
		struct timespec sleepUntil = { time(NULL) + WAITEOF_DELAY, 0 };
		pthread_mutex_lock(&readMutex);
		if (pthread_cond_timedwait(&readCompleteCondition, &readMutex, (const struct timespec *)&sleepUntil) != 0)
			gWaitEOF = false;
		pthread_mutex_unlock(&readMutex);
		pthread_join( thr,NULL);				/* wait for the child thread to return */
	}

	(*classdriver)->Close( classdriver );	// forces the read to stop incase we are doing a blocking read
	UsbUnloadClassDriver( activePrinter );
	/*
	* Close the socket connection and input file and return...
	*/
	free( buffer );

	if (STDIN_FILENO != fd)
		close(fd);

	if (gReadCompleteConditionPtr != NULL)
		pthread_cond_destroy(gReadCompleteConditionPtr);
	if (gReadMutexPtr != NULL)
		pthread_mutex_destroy(gReadMutexPtr);

	return status == kIOReturnSuccess? 0: status;
}

static Boolean
encodecfstr( CFStringRef cfsrc, char *dst, long len )
{
	return CFStringGetCString(cfsrc? cfsrc:CFSTR("Unknown"), dst, len, kCFStringEncodingUTF8 );
}

/*
* 'list_devices()' - List all USB devices.
*/
void list_devices(void)
{
	char				encodedManufacturer[1024];
	char				encodedProduct[1024];
	char				uri[1024];
    CFMutableArrayRef	usbBusPrinters = UsbGetAllPrinters();
    CFIndex				i, numPrinters = NULL != usbBusPrinters? CFArrayGetCount( usbBusPrinters ): 0;
    
 	puts("direct usb \"Unknown\" \"USB Printer (usb)\"");
    for ( i = 0;  i < numPrinters; ++i )
    {
        USBPrinterInfo		*printer = (USBPrinterInfo *) CFArrayGetValueAtIndex( usbBusPrinters, i );

		if ( printer ) 
		{
			CFStringRef	addressRef = UsbMakeFullUriAddress( printer );
			if ( addressRef )
			{
				if ( CFStringGetCString(addressRef, uri, sizeof(uri), kCFStringEncodingUTF8) ) {
			
					encodecfstr( printer->address.manufacturer, encodedManufacturer, sizeof(encodedManufacturer) );
					encodecfstr( printer->address.product, encodedProduct, sizeof(encodedProduct) );
					printf("direct %s \"%s %s\" \"%s\"\n", uri, encodedManufacturer, encodedProduct, encodedProduct);
				}
			}
		}
    }
    UsbReleaseAllPrinters( usbBusPrinters );
	fflush(NULL);
}


static void parseOptions(const char *options, char *serial, UInt32 *location)
{
	char	*serialnumber;	/* ?serial=<serial> or ?location=<location> */
	char	optionName[255],	/* Name of option */
			value[255],			/* Value of option */
			*ptr;				/* Pointer into name or value */

	if (serial)
		*serial = '\0';
	if (location)
		*location = 0;

	if (!options)
		return;

	serialnumber = NULL;

	while (*options != '\0')
	{
		/*
		* Get the name...
		*/
		for (ptr = optionName; *options && *options != '=' && *options != '+'; )
			*ptr++ = *options++;

		*ptr = '\0';
		value[0] = '\0';

		if (*options == '=')
		{
			/*
			* Get the value...
			*/
			
			options ++;
			
			for (ptr = value; *options && *options != '+';)
				*ptr++ = *options++;

			*ptr = '\0';
			
			if (*options == '+')
				options ++;
		}
		else if (*options == '+')
		{
			options ++;
		}

		/*
		* Process the option...
		*/
		if (strcasecmp(optionName, "waiteof") == 0)
		{
			if (strcasecmp(value, "on") == 0 ||
				strcasecmp(value, "yes") == 0 ||
				strcasecmp(value, "true") == 0)
			{
				gWaitEOF = true;
			}
			else if (strcasecmp(value, "off") == 0 ||
					strcasecmp(value, "no") == 0 ||
					strcasecmp(value, "false") == 0)
			{
				gWaitEOF = false;
			}
			else
			{
				fprintf(stderr, "WARNING: Boolean expected for waiteof option \"%s\"\n", value);
			}
		}
		else if (strcasecmp(optionName, "serial") == 0)
		{
			strcpy(serial, value);
			serialnumber = serial;
		}
		else if (strcasecmp(optionName, "location") == 0 && location)
		{
			*location = strtol(value, NULL, 16);
		}
		else if (strcasecmp(optionName, "bidi") == 0)
		{
			if (strcasecmp(value, "on") == 0 ||
				strcasecmp(value, "yes") == 0 ||
				strcasecmp(value, "true") == 0)
			{
				gBidi = true;
			}
			else if (strcasecmp(value, "off") == 0 ||
					strcasecmp(value, "no") == 0 ||
					strcasecmp(value, "false") == 0)
			{
				gBidi = false;
			}
			else
			{
				fprintf(stderr, "WARNING: Boolean expected for bidi option \"%s\"\n", value);
			}
		}
	}

	return;
}


/*!
 * @function  addPercentEscapes
 * @abstract  Encode a string with percent escapes
 *
 * @param  src		The source C string
 * @param  dst		Desination buffer
 * @param  dstMax	Size of desination buffer
 *
 * @result    A non-zero return value for errors
 */
static int addPercentEscapes(const unsigned char* src, char* dst, int dstMax)
{
  unsigned char	c;
  char		*dstEnd = dst + dstMax - 1;	/* -1 to leave room for the NUL */

  while (*src)
  {
    c = *src++;

    if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || 
        (c >= '0' && c <= '9') || (c == '.' || c == '-'  || c == '*' || c == '_'))
    {
      if (dst >= dstEnd)
        return -1;

      *dst++ = c;
    }
    else
    {
      if (dst >= dstEnd - 2)
        return -1;

      snprintf(dst, dstEnd - dst, "%%%02x", c);
      dst += 3;
    }
  }

  *dst = '\0';
  return 0;
}

/*!
 * @function	setupCFLanguage
 * @abstract	Convert the contents of the CUPS 'LANG' environment
 *		variable into a one element CF array of languages.
 *
 * @discussion	Each submitted job comes with a natural language. CUPS passes
 * 		that language in an environment variable. We take that language
 * 		and jam it into the AppleLanguages array so that CF will use
 * 		it when reading localized resources. We need to do this before
 * 		any CF code reads and caches the languages array, so this function
 *		should be called early in main()
 */
static void setupCFLanguage(void)
{
    CFStringRef lang[1] = {NULL};
    CFArrayRef langArray = NULL;
    const char *requestedLang = NULL;

    requestedLang = getenv("LANG");
    if (requestedLang != NULL) {
        lang[0] = CFStringCreateWithCString(kCFAllocatorDefault, requestedLang, kCFStringEncodingUTF8);
        langArray = CFArrayCreate(kCFAllocatorDefault, (const void **)lang, sizeof(lang) / sizeof(lang[0]), &kCFTypeArrayCallBacks);

        CFPreferencesSetAppValue(CFSTR("AppleLanguages"), langArray, kCFPreferencesCurrentApplication);
        fprintf(stderr, "DEBUG: usb: AppleLanguages = \"%s\"\n", requestedLang);

        CFRelease(lang[0]);
        CFRelease(langArray);
    } else {
        fprintf(stderr, "DEBUG: usb: LANG environment variable missing.\n");
    }
}

/*!
 * @function	removePercentEscapes
 * @abstract	Returns a string with any percent escape sequences replaced with their equivalent character
 *
 * @param		src		Source buffer
 * @param		srclen	Number of bytes in source buffer
 * @param		dst		Desination buffer
 * @param		dstMax	Size of desination buffer
 *
 * @result		A non-zero return value for errors
 */
static int removePercentEscapes(const char* src, unsigned char* dst, int dstMax)
{
	int c;
	const unsigned char *dstEnd = dst + dstMax;

	while (*src && dst < dstEnd)
	{
		c = *src++;

		if (c == '%')
		{
			sscanf(src, "%02x", &c);
			src += 2;
		}
		*dst++ = (char)c;
	}

	if (dst >= dstEnd)
		return -1;

	*dst = '\0';
	return 0;
}

/*-----------------------------------------------------------------------------*

        DelimitSubstring

        Desc:	Search a string from a starting location, looking for a given
        		delimiter. Return the range from the start of the search to the
        		delimiter, or end of string (whichever is shorter).

        In:		stringToSearch		string which contains a substring that we search
        		delim				string which marks the end of the string 
        		bounds				start and length of substring of stringToSearch
        		options				case sensitive, anchored, etc.

        Out:	Range up to the delimiter.

*-----------------------------------------------------------------------------*/
static CFRange
DelimitSubstring( CFStringRef stringToSearch, CFStringRef delim, CFRange bounds, CFStringCompareFlags options )
{
    CFRange 	where_delim,	// where the delimiter was found
                value;
    //
    //	trim leading space by changing bounds
    //
    while ( bounds.length > 0 && CFStringFindWithOptions( stringToSearch, CFSTR(" "), bounds, kCFCompareAnchored, &where_delim ) )
    {
        ++bounds.location;	// drop a leading ' '
        --bounds.length;
    }
    value = bounds;			// assume match to the end of string, may be NULL
    //
    //	find the delimiter in the remaining string
    //
    if (  bounds.length > 0 && CFStringFindWithOptions( stringToSearch, delim, bounds, options, &where_delim ) )
    {
        //
        // match to the delimiter
        //
        value.length = where_delim.location /* delim */ - bounds.location /* start of search */;
    }
    DEBUG_CFString( "\tFind target", stringToSearch );
    DEBUG_CFString( "\tFind pattern", delim );
    DEBUG_ERR( (int) value.location, "\t\tFound %d\n" );
    DEBUG_ERR( (int) value.length, " length %d"  );

    return value;
}


/*-----------------------------------------------------------------------------*

        DeviceIDCreateValueList

        Desc:	Create a new string for the value list of the specified key.
        		The key may be specified as two strings (an abbreviated form
        		and a standard form). NULL can be passed for either form of 
        		the key.
        		
        		(Although passing NULL for both forms of the key is considered
        		 bad form[!] it is handled correctly.)

        In:		deviceID	the device's IEEE-1284 DeviceID key-value list
        		abbrevKey	the key we're interested in (NULL allowed)
        		key			

        Out:	CFString	the value list 
        		or NULL		key wasn't found in deviceID

*-----------------------------------------------------------------------------*/
CFStringRef
DeviceIDCreateValueList( const CFStringRef deviceID, const CFStringRef abbrevKey, const CFStringRef key )
{
    CFRange 	found = CFRangeMake( -1,0);   // note CFStringFind sets length 0 if string not found
    CFStringRef	valueList = NULL;

	DEBUG_CFString( "---------DeviceIDCreateValueList DeviceID:", deviceID );
    DEBUG_CFString( "---------DeviceIDCreateValueList key:", key );
	DEBUG_CFString( "---------DeviceIDCreateValueList abbrevkey:", abbrevKey );
   if ( NULL != deviceID && NULL != abbrevKey )
        found = CFStringFind( deviceID, abbrevKey, kCFCompareCaseInsensitive );
    if (  NULL != deviceID && NULL != key && found.length <= 0 )
        found = CFStringFind( deviceID, key, kCFCompareCaseInsensitive );
    if ( found.length > 0 )
    {
        // the key is at found
        // the value follows the key until we reach the semi-colon, or end of string
        //
        CFRange	search = CFRangeMake( found.location + found.length,
                                  CFStringGetLength( deviceID ) - (found.location + found.length) );
        //
        // finally extract the string
        //
        valueList = CFStringCreateWithSubstring ( kCFAllocatorDefault, deviceID,
                                                  DelimitSubstring( deviceID, kDeviceIDKeyValuePairDelimiter, search, kCFCompareCaseInsensitive ) );
	DEBUG_CFString( "---------DeviceIDCreateValueList:", valueList );
    }
    return valueList;

}



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

/*-----------------------------------------------------------------------------*

CompareSameString

Desc:	Return the CFCompare result for two strings, either or both of which
        can be NULL.

In:
        a		current value
        b		last value

Out:
        0		if the strings match
        non-zero	if the strings don't match

*-----------------------------------------------------------------------------*/
static int
CompareSameString( const CFStringRef a, const CFStringRef b )
{
    if ( NULL == a && NULL == b )
        return 0;
    else if ( NULL != a && NULL != b )
        return CFStringCompare( a, b, kCFCompareAnchored );
    else
        return 1;	// one of a or b is NULL this time, but wasn't last time
}


/******************************************************************************/
kern_return_t
UsbLoadClassDriver( USBPrinterInfo *printer, CFUUIDRef interfaceID, CFStringRef classDriverBundle )
{
	kern_return_t	kr = kUSBPrinterClassDeviceNotOpen;
	if ( NULL != classDriverBundle )
		printer->bundle = classDriverBundle;	// vendor-specific class override
	else
		classDriverBundle = kUSBGenericTOPrinterClassDriver;	//	supply the generic TIMEOUT class driver

	DEBUG_CFString( "UsbLoadClassDriver classDriverBundle", classDriverBundle );
    if ( NULL != classDriverBundle )
    {
        USBPrinterClassContext	**classdriver = NULL;
        CFURLRef				classDriverURL = CFURLCreateWithFileSystemPath( NULL, classDriverBundle, kCFURLPOSIXPathStyle, TRUE );
        CFPlugInRef 			plugin = NULL == classDriverURL? NULL: CFPlugInCreate( NULL, classDriverURL );
        if ( NULL != plugin)
        {
            // See if this plug-in implements the Test type.
            CFArrayRef factories =  CFPlugInFindFactoriesForPlugInTypeInPlugIn( kUSBPrinterClassTypeID, plugin );

            // If there are factories for the requested type, attempt to
            // get the IUnknown interface.
			DEBUG_ERR( 0, "UsbLoadClassDriver plugin %x\n" );
            if (NULL != factories && CFArrayGetCount(factories) > 0) 
            {
                // Get the factory ID for the first location in the array of IDs.
                CFUUIDRef factoryID = CFArrayGetValueAtIndex( factories, 0 );
                // Use the factory ID to get an IUnknown interface.
                // Here the code for the PlugIn is loaded.
                IUnknownVTbl **iunknown = CFPlugInInstanceCreate( NULL, factoryID, kUSBPrinterClassTypeID );
                // If this is an IUnknown interface, query for the Test interface.
				DEBUG_ERR( 0, "UsbLoadClassDriver factories %x\n" );
                if (NULL != iunknown)
                {
					DEBUG_ERR( 0, "UsbLoadClassDriver CFPlugInInstanceCreate %x\n" );
                    kr = (*iunknown)->QueryInterface( iunknown, CFUUIDGetUUIDBytes(interfaceID), (LPVOID *) &classdriver );

                    (*iunknown)->Release( iunknown );
                    if ( S_OK == kr && NULL != classdriver )
                    {
						DEBUG_ERR( kr, "UsbLoadClassDriver QueryInterface %x\n" );
						printer->plugin = plugin;
                        kr = (*classdriver)->Initialize( classdriver, printer->classdriver );
						
						kr = kIOReturnSuccess;
						printer->classdriver = classdriver;
                    }
					else
					{
						DEBUG_ERR( kr, "UsbLoadClassDriver QueryInterface FAILED %x\n" );
					}
                }
				else
				{
					DEBUG_ERR( kr, "UsbLoadClassDriver CFPlugInInstanceCreate FAILED %x\n" );
				}
            }
			else
			{
				DEBUG_ERR( kr, "UsbLoadClassDriver factories FAILED %x\n" );
			}
        }
		else
		{
			DEBUG_ERR( kr, "UsbLoadClassDriver plugin FAILED %x\n" );
		}
        if ( kr != kIOReturnSuccess || NULL == plugin || NULL == classdriver )
        {
            UsbUnloadClassDriver( printer );
        }
    }
	
	return kr;
}


kern_return_t
UsbUnloadClassDriver( USBPrinterInfo *printer )
{
	DEBUG_ERR( kIOReturnSuccess, "UsbUnloadClassDriver %x\n" );
	if ( NULL != printer->classdriver )
		(*printer->classdriver)->Release( printer->classdriver );
	printer->classdriver = NULL;
	
	if ( NULL != printer->plugin )
		CFRelease( printer->plugin );
	printer->plugin = NULL;
	
	return kIOReturnSuccess;
}


/*-----------------------------------------------------------------------------*

	UsbAddressDispose

	Desc:	deallocates anything used to create a persistent printer address

	In:	address		the printer address we've created

	Out:	<none>

*-----------------------------------------------------------------------------*/
void
UsbAddressDispose( USBPrinterAddress *address )
{
	if ( address->product != NULL ) CFRelease( address->product );
	if ( address->manufacturer != NULL ) CFRelease( address->manufacturer );
	if ( address->serial != NULL ) CFRelease( address->serial );
	if ( address->command != NULL ) CFRelease( address->command );

	address->product =
	address->manufacturer =
	address->serial =
	address->command = NULL;

}

/*-----------------------------------------------------------------------------*

	UsbGetPrinterAddress

	Desc:	Given a printer we're enumerating, discover it's persistent
	reference.

	A "persistent reference" is one which enables us to identify
	a printer regardless of where it resides on the USB topology,
	and enumeration sequence.

	To do this, we actually construct a reference from information
	buried inside the printer. First we look at the USB device
	descripton: an ideally defined device will support strings for
	manufacturer and product id, and serial number. The serial number
	will be unique for each printer.

	Our prefered identification fetches the IEEE-1284 device id string.
	This transparently handled IEEE-1284 compatible printers which
	connected over a USB-parallel cable. Only if we can't get all the
	information to uniquely identify the printer do we try the strings
	referenced in the printer's USB device descriptor. (These strings
	are typically absent in a USB-parallel cable.)

	If a device doesn't support serial numbers we have a problem:
	we can't distinguish between two identical printers. Unique serial
	numbers allow us to distinguish between two same-model, same-manufacturer
	USB printers.

	In:
		thePrinter		iterator required for fetching device descriptor
		devRefNum		required to configure the interface

	Out:
		address->manufacturer
		address->product
		address->serial
				Any (and all) of these may be NULL if we can't retrieve
				information for IEEE1284 DeviceID or the USB device
				descriptor. Caller should be prepared to handle such a case.
		address->command
				May be updated.

*-----------------------------------------------------------------------------*/
OSStatus
UsbGetPrinterAddress( USBPrinterInfo *thePrinter, USBPrinterAddress *address, UInt16 timeout )
{

	//
	//	start by assuming the device is not IEEE-1284 compliant
	//	and that we can't read in the required strings.
	//
	OSStatus				err;
    CFStringRef				deviceId = NULL;
    USBPrinterClassContext	**printer = NULL == thePrinter? NULL: thePrinter->classdriver;
	
	address->manufacturer =
	address->product =
    address->compatible =
	address->serial =
    address->command = NULL;

    DEBUG_DUMP( "UsbGetPrinterAddress thePrinter", thePrinter, sizeof(USBPrinterInfo) );

    err = (*printer)->GetDeviceID( printer, &deviceId, timeout );
    if ( noErr == err && NULL != deviceId )
    {
        // the strings embedded here are defined in the IEEE1284 spec
        //
        //	use the MFG/MANUFACTURER for the manufacturer
        //	and the MDL/MODEL for the product
        //  there is no serial number defined in IEEE1284
        //		but it's been observed in recent HP printers
        //
        address->command = DeviceIDCreateValueList( deviceId, kDeviceIDKeyCommandAbbrev, kDeviceIDKeyCommand );

        address->product = DeviceIDCreateValueList( deviceId, kDeviceIDKeyModelAbbrev, kDeviceIDKeyModel );
        address->compatible = DeviceIDCreateValueList( deviceId, kDeviceIDKeyCompatibleAbbrev, kDeviceIDKeyCompatible );

        address->manufacturer = DeviceIDCreateValueList( deviceId, kDeviceIDKeyManufacturerAbbrev, kDeviceIDKeyManufacturer );

        address->serial = DeviceIDCreateValueList( deviceId, kDeviceIDKeySerialAbbrev, kDeviceIDKeySerial );
        CFRelease( deviceId );
    }
    DEBUG_CFString( "UsbGetPrinterAddress DeviceID address->product", address->product );
    DEBUG_CFString( "UsbGetPrinterAddress DeviceID address->compatible", address->compatible );
    DEBUG_CFString( "UsbGetPrinterAddress DeviceID address->manufacturer", address->manufacturer );
    DEBUG_CFString( "UsbGetPrinterAddress DeviceID address->serial", address->serial );

    if ( NULL == address->product || NULL == address->manufacturer || NULL == address->serial )
    {
        //
        //	if the manufacturer or the product or serial number were not specified in DeviceID
        //		try to construct the address using USB English string descriptors
        //
        IOUSBDeviceDescriptor	desc;
        USBIODeviceRequest		request;
                                
        request.requestType = USBmakebmRequestType( kUSBIn,  kUSBStandard, kUSBDevice );
        request.request = kUSBRqGetDescriptor;
        request.value = (kUSBDeviceDesc << 8) | 0;
        request.index = 0; 	/* not kUSBLanguageEnglish*/
        request.length = sizeof(desc);
        request.buffer = &desc;
        err = (*printer)->DeviceRequest( printer, &request, timeout );
        DEBUG_ERR( (kern_return_t) err, "UsbGetPrinterAddress: GetDescriptor %x" );
        if ( kIOReturnSuccess == err )
        {
            // once we've retrieved the device descriptor
            //	try to fill in missing pieces of information
            //
            //	Don't override any information already retrieved from DeviceID.

            if ( NULL == address->product)
            {
                err = (*printer)->GetString( printer, desc.iProduct, kUSBLanguageEnglish, timeout, &address->product );
                if ( kIOReturnSuccess != err || address->product == NULL) {
                    address->product = CFSTR("Unknown");
                }                
            }
            DEBUG_CFString( "UsbGetPrinterAddress: UsbGetString address->product\n", address->product );

            if ( NULL == address->manufacturer )
            {
                err = (*printer)->GetString( printer, desc.iManufacturer, kUSBLanguageEnglish, timeout, &address->manufacturer );
                if (kIOReturnSuccess != err || address->manufacturer == NULL) {
                    address->manufacturer = CFSTR("Unknown");
                }
            }
            DEBUG_CFString( "UsbGetPrinterAddress: UsbGetString address->manufacturer\n", address->manufacturer );

            if ( NULL == address->serial )
            {
				// if the printer doesn't have a serial number, use locationId
				if ( 0 == desc.iSerialNumber )
				{
					address->serial = CFStringCreateWithFormat( NULL, NULL, CFSTR("%lx"), (*printer)->location );
				}
				else
				{
					err = (*printer)->GetString( printer, desc.iSerialNumber, kUSBLanguageEnglish, timeout, &address->serial );
					// trailing NULs aren't handled correctly in URI
					if ( address->serial )
					{
						UniChar		nulbyte = { 0 };
						CFStringRef trim = CFStringCreateWithCharacters(NULL, &nulbyte, 1);
						CFMutableStringRef newserial = CFStringCreateMutableCopy(NULL, 0, address->serial);

						CFStringTrim( newserial, trim );

						CFRelease(trim);
						CFRelease( address->serial );

						address->serial = newserial;
					}
				}
            }
            DEBUG_CFString( "UsbGetPrinterAddress: UsbGetString address->serial\n", address->serial );
        }
    }
    if ( NULL != address->product)
        CFRetain(address->product);         // UsbGetString is really a UsbCopyString.
    if ( NULL != address->manufacturer )
        CFRetain( address->manufacturer );
    if ( NULL != address->serial )
        CFRetain( address->serial );
    return err;
}


/*-----------------------------------------------------------------------------*

UsbSamePrinter

        Desc:	match two Usb printer address; return TRUE if they are the same.

        In:		a	the persistent address found last time
                b	the persistent address found this time

        Out:	non-zero iff the addresses are the same

*-----------------------------------------------------------------------------*/
int
UsbSamePrinter( const USBPrinterAddress *a, const USBPrinterAddress *b )
{
    int result = 0;
    DEBUG_CFCompareString( "UsbSamePrinter serial", a->serial, b->serial );
    DEBUG_CFCompareString( "UsbSamePrinter product", a->product, b->product );
    DEBUG_CFCompareString( "UsbSamePrinter manufacturer", a->manufacturer, b->manufacturer );

    result = !CompareSameString( a->serial, b->serial );
    if ( result )  result = !CompareSameString( a->product, b->product );
    if ( result ) result = !CompareSameString( a->manufacturer, b->manufacturer );

    return result;
}


/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	Method:		UsbMakeFullUriAddress

	Input Parameters:

	Output Parameters:

	Description:
        Fill in missing address information

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
CFStringRef
UsbMakeFullUriAddress( USBPrinterInfo *printer )
{
    //
    //	fill in missing address information.
    //
    CFMutableStringRef printerUri = CFStringCreateMutableCopy(kCFAllocatorDefault, 0, CFSTR("usb://") );
    if ( NULL != printerUri )
    {
		CFStringRef serial = printer->address.serial;

		CFStringAppend(printerUri, printer->address.manufacturer? CreateEncodedCFString( printer->address.manufacturer ): CFSTR("Unknown") );
        CFStringAppend(printerUri, CFSTR("/") );

		CFStringAppend(printerUri, printer->address.product? CreateEncodedCFString( printer->address.product ): CFSTR("Unknown") );

        //Handle the common case where there is no serial number (S450?)
		CFStringAppend(printerUri, serial == NULL? CFSTR("?location="): CFSTR("?serial=") );
        if ( serial == NULL)
            serial = CFStringCreateWithFormat( NULL, NULL, CFSTR("%lx"), printer->location );

         CFStringAppend(printerUri,  serial? CreateEncodedCFString( serial ): CFSTR("Unknown") );
    }
    
    return printerUri;
}


/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	Method:		UsbGetAllPrinters

	Input Parameters:

	Output Parameters:
		array of all USB printers on the system

	Description:
        Build a list of USB printers by iterating IOKit USB objects

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
CFMutableArrayRef
UsbGetAllPrinters( void )
{
    kern_return_t		kr;		// kernel errors
    mach_port_t			master_device_port = 0;
    io_service_t		usbInterface = 0;
    io_iterator_t 		iter = 0;
    CFMutableArrayRef	printers = CFArrayCreateMutable( NULL, 0, NULL );	// all printers

    do
    {

        kr = IOMasterPort( bootstrap_port, &master_device_port );
        DEBUG_ERR( kr, "UsbGetAllPrinters IOMasterPort %x\n" );
        if(kIOReturnSuccess != kr)  break;

        {
            CFDictionaryRef 	usbMatch = NULL;
            
            // iterate over all interfaces. 
            usbMatch = IOServiceMatching(kIOUSBInterfaceClassName);
            if ( !usbMatch ) break;
            DEBUG_ERR( kr, "UsbGetAllPrinters IOServiceMatching %x\n" );
        
            // IOServiceGetMatchingServices() consumes the usbMatch reference so we don't need to release it.
            kr = IOServiceGetMatchingServices(master_device_port, usbMatch, &iter);
            usbMatch = NULL;
            
            DEBUG_ERR( kr, "UsbGetAllPrinters IOServiceGetMatchingServices %x\n" );
            if(kIOReturnSuccess != kr || iter == 0)  break;
        }
        
        while (  0 != (usbInterface = IOIteratorNext(iter))  )
        {
            IOCFPlugInInterface 	**iodev;
            USBPrinterInterface		intf;
            HRESULT 				res;
            SInt32 					score;
            CFMutableDictionaryRef	properties;
            CFStringRef				classDriver = NULL;

            kr = IORegistryEntryCreateCFProperties( usbInterface, &properties, kCFAllocatorDefault, kNilOptions);
            if ( kIOReturnSuccess == kr && NULL != properties)
            {
                classDriver = (CFStringRef) CFDictionaryGetValue( properties, kUSBClassDriverProperty );
                if ( NULL != classDriver )
                    CFRetain( classDriver );
                CFRelease( properties );
            }    

            kr = IOCreatePlugInInterfaceForService(	usbInterface,
                                                        kIOUSBInterfaceUserClientTypeID, 
                                                        kIOCFPlugInInterfaceID,
                                                        &iodev,
                                                        &score);
                
            DEBUG_ERR( kr, "UsbGetAllPrinters IOCreatePlugInInterfaceForService %x\n" );
            if ( kIOReturnSuccess == kr )
            {
                UInt8				intfClass = 0;
                UInt8				intfSubClass = 0;
 
                res = (*iodev)->QueryInterface( iodev, USB_INTERFACE_KIND, (LPVOID *) &intf);
                DEBUG_ERR( (kern_return_t) res, "UsbGetAllPrinters QueryInterface %x\n" );

               (*iodev)->Release(iodev);
                if ( noErr != res ) break;
 
                kr = (*intf)->GetInterfaceClass(intf, &intfClass);
                DEBUG_ERR(kr, "UsbGetAllPrinters GetInterfaceClass %x\n");
                if ( kIOReturnSuccess == kr )
                    kr = (*intf)->GetInterfaceSubClass(intf, &intfSubClass);
                DEBUG_ERR(kr, "UsbGetAllPrinters GetInterfaceSubClass %x\n");
                
                if ( kIOReturnSuccess == kr &&
                        kUSBPrintingClass == intfClass &&
                        kUSBPrintingSubclass == intfSubClass )
                {

                    USBPrinterInfo			printer,
                                            *printerInfo;
                    /*
                    For each type of printer specified in the lookup spec array, find
                    all of that type of printer and add the results to the list of found
                    printers.
                    */
                    // create this printer's persistent address
                    memset( &printer, 0, sizeof(USBPrinterInfo) );
                    kr = (*intf)->GetLocationID(intf, &printer.location);
                    DEBUG_ERR(kr, "UsbGetAllPrinters GetLocationID %x\n");
                    if ( kIOReturnSuccess == kr )
                    {
                        kr = UsbLoadClassDriver( &printer, kUSBPrinterClassInterfaceID, classDriver );

			if ( kIOReturnSuccess != kr && NULL != classDriver )
			{
				fprintf(stderr, "DEBUG: Unable to load USB class driver (%d), using generic class driver instead\n", (int)kr);
				printer.classdrivererror = kr;
				kr = UsbLoadClassDriver( &printer, kUSBPrinterClassInterfaceID, NULL ); // fallback to default class driver
			}

                        DEBUG_ERR(kr, "UsbGetAllPrinters UsbLoadClassDriver %x\n");
						if ( kIOReturnSuccess == kr && printer.classdriver )
						{
							(*(printer.classdriver))->interface = intf;
							kr = UsbGetPrinterAddress( &printer, &printer.address, 60000L );
							{ 
								// always unload the driver
								//	but don't mask last error
								kern_return_t unload_err = UsbUnloadClassDriver( &printer );
								if ( kIOReturnSuccess == kr )
									kr = unload_err;
							}
						}
                    }
                    
                    printerInfo = UsbCopyPrinter( &printer );
                    if ( NULL != printerInfo )
                        CFArrayAppendValue( printers, (const void *) printerInfo );		// keep track of it

                 } // if there's a printer
                kr = (*intf)->Release(intf);
            } // if IOCreatePlugInInterfaceForService
            
            IOObjectRelease(usbInterface);
            usbInterface = 0;
            
        } // while there's an interface
    } while ( 0 );

    if (iter) 
    {
        IOObjectRelease(iter);
        iter = 0;
    }

    if (master_device_port) 
    {
        mach_port_deallocate(mach_task_self(), master_device_port);
        master_device_port = 0;
    }
    return printers;

} // UsbGetAllPrinters

/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	Method:		UsbReleasePrinter

	Input Parameters:

	Output Parameters:

	Description:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
void
UsbReleasePrinter( USBPrinterInfo *printer )
{
    if ( printer )
    {
		UsbUnloadClassDriver( printer );
        if ( NULL != printer->address.manufacturer )
            CFRelease( printer->address.manufacturer );
        if ( NULL != printer->address.product )
            CFRelease( printer->address.product );
        if ( NULL != printer->address.serial )
            CFRelease( printer->address.serial );
        if ( NULL != printer->address.command )
            CFRelease( printer->address.command );
        if ( NULL != printer->bundle )
            CFRelease( printer->bundle );
        free( printer );
   }
}

/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	Method:		UsbReleaseAllPrinters

	Input Parameters:

	Output Parameters:

	Description:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
void
UsbReleaseAllPrinters( CFMutableArrayRef printers )
{
	if ( NULL != printers )
	{
		CFIndex i,
				numPrinters = CFArrayGetCount(printers);
		for ( i = 0; i < numPrinters; ++i ) 
			UsbReleasePrinter( (USBPrinterInfo *) CFArrayGetValueAtIndex( printers, i ) );
		CFRelease( printers );			
	}
}

USBPrinterInfo *
UsbCopyPrinter( USBPrinterInfo *aPrinter )
{
    //
    //	note this does not copy interface information, just address information
    //
    USBPrinterInfo *printerInfo = (USBPrinterInfo *) calloc( 1, sizeof(USBPrinterInfo));
    if ( NULL != printerInfo && NULL != aPrinter )
    {
        printerInfo->location = aPrinter->location;
        printerInfo->classdrivererror = aPrinter->classdrivererror;

        if ( NULL != (printerInfo->address.manufacturer = aPrinter->address.manufacturer) )
            CFRetain( printerInfo->address.manufacturer );
        if ( NULL != (printerInfo->address.product = aPrinter->address.product) )
            CFRetain( printerInfo->address.product );
        if ( NULL != (printerInfo->address.serial = aPrinter->address.serial) )
            CFRetain( printerInfo->address.serial );
        if ( NULL != (printerInfo->address.command = aPrinter->address.command) )
            CFRetain( printerInfo->address.command );
        if ( NULL != (printerInfo->bundle = aPrinter->bundle) )
            CFRetain( printerInfo->bundle );
    }
    
    return printerInfo;
}

/*-----------------------------------------------------------------------------*

        UsbRegistryOpen

        Desc:	opens the USB printer which matches the supplied printerAddress

        In:		myContext->printerAddress	persistent name which identifies the printer

        Out:	myContext->usbDeviceRef 	current IOKit address of this printer
*-----------------------------------------------------------------------------*/
kern_return_t
UsbRegistryOpen( USBPrinterAddress *usbAddress, USBPrinterInfo **result )
{
    kern_return_t		kr = -1;	// indeterminate failure
    CFMutableArrayRef	printers = UsbGetAllPrinters();
    CFIndex				numPrinters = NULL != printers? CFArrayGetCount( printers): 0;
    CFIndex				i;

    *result = NULL;	// nothing matched
    for ( i = 0; i < numPrinters; ++i )
    {
        USBPrinterInfo	*thisPrinter = (USBPrinterInfo *) CFArrayGetValueAtIndex( printers, i );
        if (  NULL != thisPrinter && UsbSamePrinter( usbAddress, &thisPrinter->address ) ) 
        {
            *result = UsbCopyPrinter( thisPrinter );	// retains reference
            if ( NULL != *result )
            {
                //
                //	if we can't find a bi-di interface, settle for a known uni-directional interface
                //
                USBPrinterClassContext **printer = NULL;
				//
                //	setup the default class driver
                //	If one is specified, allow the vendor driver to override our default implementation
				//
                kr = UsbLoadClassDriver( *result, kUSBPrinterClassInterfaceID, NULL );
				if ( kIOReturnSuccess == kr && (*result)->bundle )
					kr = UsbLoadClassDriver( *result, kUSBPrinterClassInterfaceID, (*result)->bundle );
                if ( kIOReturnSuccess == kr && NULL != (*result)->classdriver )
                {
                    printer = (*result)->classdriver;
                    kr = (*printer)->Open( printer, (*result)->location, kUSBPrintingProtocolBidirectional );
                    if ( kIOReturnSuccess != kr || NULL == (*printer)->interface )
                        kr = (*printer)->Open( printer, (*result)->location, kUSBPrintingProtocolUnidirectional );
                    //	it's possible kIOReturnSuccess == kr && NULL == (*printer)->interface
                    //		in the event that we can't open either Bidirectional or Unidirectional interface
                    if ( kIOReturnSuccess == kr )
                    {
                        if ( NULL == (*printer)->interface )
                        {
                            (*printer)->Close( printer );
                            UsbReleasePrinter( *result );
                            *result = NULL;
                        }
                    }
                }
            }
            break;
        }
    }
    UsbReleaseAllPrinters( printers ); // but, copied printer is retained
    DEBUG_ERR( kr, "UsbRegistryOpen return %x\n" );

    return kr;
}

/*!
 * @function	CreateEncodedCFString
 *
 * @abstract	Create an encoded version of the string parameter 
 *				so that it can be included in a URI.
 *
 * @param	string	A CFStringRef of the string to be encoded.
 * @result	An encoded CFString.
 *
 * @discussion	This function will change all characters in string into URL acceptable format
 *				by encoding the text using the US-ASCII coded character set.  The following
 *				are invalid characters: the octets 00-1F, 7F, and 80-FF hex.  Also called out
 *				are the chars "<", ">", """, "#", "{", "}", "|", "\", "^", "~", "[", "]", "`".
 *				The reserved characters for URL syntax are also to be encoded: (so don't pass
 *				in a full URL here!) ";", "/", "?", ":", "@", "=", "%", and "&".
 */
static CFStringRef CreateEncodedCFString(CFStringRef string)
{
	CFStringRef result = NULL;
	char *bufferUTF8 = NULL;
	char *bufferEncoded = NULL;

	if (string != NULL)
	{
		CFIndex bufferSizeUTF8 = (3 * CFStringGetLength(string));
		if ((bufferUTF8 = (char*)malloc(bufferSizeUTF8)) != NULL)
		{
			CFStringGetCString(string, bufferUTF8, bufferSizeUTF8, kCFStringEncodingUTF8);
            {
                UInt16 bufferSizeEncoded = (3 * strlen(bufferUTF8)) + 1;
                if ((bufferEncoded = (char*)malloc(bufferSizeEncoded)) != NULL)
                {
                    addPercentEscapes((unsigned char*)bufferUTF8, (char*)bufferEncoded, bufferSizeEncoded);
                    result = CFStringCreateWithCString(kCFAllocatorDefault, bufferEncoded, kCFStringEncodingUTF8);
                }
            }
		}
	}

	if (bufferUTF8)		free(bufferUTF8);
	if (bufferEncoded)	free(bufferEncoded);

	return result;
}


#if defined(__i386__)
/*!
 * @function	run_ppc_backend
 *
 * @abstract	Starts child backend process running as a ppc executable.
 *
 * @result	Never returns; always calls exit().
 *
 * @discussion	
 */
static void run_ppc_backend(int argc, char *argv[], int fd)
{
	int	i;
	int	exitstatus = 0;
	int	childstatus;
	pid_t	waitpid_status;
	char	*my_argv[32];
	char	*usb_ppc_status;

	/*
	* If we're running as i386 and couldn't load the class driver (because they'it's
	* ppc-only) then try to re-exec ourselves in ppc mode to try again. If we don't have
	* a ppc architecture we may be running i386 again so guard against this by setting
	* and testing an environment variable...
	*/

	usb_ppc_status = getenv("USB_PPC_STATUS");

	if (usb_ppc_status == NULL)
	{
		/*
		* Catch SIGTERM if we are _not_ printing data from
		* stdin (otherwise you can't cancel raw jobs...)
		*/
		
		if (fd != 0)
		{
	#ifdef HAVE_SIGSET /* Use System V signals over POSIX to avoid bugs */
			sigset(SIGTERM, sigterm_handler);
	#elif defined(HAVE_SIGACTION)
			struct sigaction action;	/* Actions for POSIX signals */
			memset(&action, 0, sizeof(action));
			sigaddset(&action.sa_mask, SIGTERM);
			action.sa_handler = sigterm_handler;
			sigaction(SIGTERM, &action, NULL);
	#else
			signal(SIGTERM, sigterm_handler);
	#endif /* HAVE_SIGSET */
		}
	
		if ((child_pid = fork()) == 0)
		{
			/* Child comes here. */

			setenv("USB_PPC_STATUS", "1", false);

			/*
			* Tell the kernel we want the next exec call to favor the ppc architecture...
			*/
	
			int mib[] = { CTL_KERN, KERN_AFFINITY, 1, 1 };
			int namelen = 4;
			sysctl(mib, namelen, NULL, NULL, NULL, 0);
	
			/*
			* Set up the arguments and call exec...
			*/
	
			for (i = 0; i < argc && i < (sizeof(my_argv)/sizeof(my_argv[0])) - 1; i++)
				my_argv[i] = argv[i];
	
			my_argv[i] = NULL;
	
			execv("/usr/libexec/cups/backend/usb", my_argv);
	
			fprintf(stderr, "DEBUG: execv: %s\n", strerror(errno));
			exitstatus = errno;
		}
		else if (child_pid > 0)
		{
			/* Parent comes here. 
			 *
			 * Close the fds we won't be using then wait for the child backend to exit.
			 */
	
			close(fd);
			close(1);
	
			fprintf(stderr, "DEBUG: Started usb(ppc) backend (PID %d)\n", (int)child_pid);
	
			 do {
				waitpid_status = waitpid(child_pid, &childstatus, 0);
			} while (waitpid_status == (pid_t)-1 && errno == EINTR);
	
			if (WIFSIGNALED(childstatus))
			{
				exitstatus = WTERMSIG(childstatus);
				fprintf(stderr, "DEBUG: usb(ppc) backend %d crashed on signal %d!\n", child_pid, exitstatus);
			}
			else
			{
				if ((exitstatus = WEXITSTATUS(childstatus)) != 0)
					fprintf(stderr, "DEBUG: usb(ppc) backend %d stopped with status %d!\n", child_pid, exitstatus);
				else
					fprintf(stderr, "DEBUG: PID %d exited with no errors\n", child_pid);
			}
		}
		else
		{
			/* fork() error */
			fprintf(stderr, "DEBUG: fork: %s\n", strerror(errno));
			exitstatus = errno;
		}
	}
	else
	{
		fprintf(stderr, "DEBUG: usb child running i386 again\n");
		exitstatus = ENOENT;
	}

	exit(exitstatus);
}

/*!
 * @function	sigterm_handler
 *
 * @abstract	Handle terminate signals.
 *
 */

static void sigterm_handler(int sig)
{
	/*
	 * If we started a child process pass the signal on to it...
	 */

	if (child_pid)
		kill(child_pid, sig);

	exit(1);
}

#endif /* __i386__ */

// eof