scsi-linux-sg.c

创建一个符合iso-9660标准的iso文件系统

/* @(#)scsi-linux-sg.c	1.52 00/07/03 Copyright 1997 J. Schilling */
#ifndef lint
static	char __sccsid[] =
	"@(#)scsi-linux-sg.c	1.52 00/07/03 Copyright 1997 J. Schilling";
#endif
/*
 *	Interface for Linux generic SCSI implementation (sg).
 *
 *	This is the interface for the broken Linux SCSI generic driver.
 *	This is a hack, that tries to emulate the functionality
 *	of the scg driver.
 *
 *	Design flaws of the sg driver:
 *	-	cannot see if SCSI command could not be send
 *	-	cannot get SCSI status byte
 *	-	cannot get real dma count of tranfer
 *	-	cannot get number of bytes valid in auto sense data
 *	-	to few data in auto sense (CCS/SCSI-2/SCSI-3 needs >= 18)
 *
 *	This code contains support for the sg driver version 2 by
 *		H. Ei遞eld & J. Schilling
 *	Although this enhanced version has been announced to Linus and Alan,
 *	there was no reaction at all.
 *
 *	About half a year later there occured a version in the official
 *	Linux that was also called version 2. The interface of this version
 *	looks like a playground - the enhancements from this version are
 *	more or less useless for a portable real-world program.
 *
 *	With Linux 2.4 the official version of the sg driver is called 3.x
 *	and seems to be usable again. The main problem now is the curious
 *	interface that is provided to raise the DMA limit from 32 kB to a
 *	more reasonable value. To do this in a reliable way, a lot of actions
 *	are required.
 *
 *	Warning: you may change this source, but if you do that
 *	you need to change the _scg_version and _scg_auth* string below.
 *	You may not return "schily" for an SCG_AUTHOR request anymore.
 *	Choose your name instead of "schily" and make clear that the version
 *	string is related to a modified source.
 *
 *	Copyright (c) 1997 J. Schilling
 */
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/version.h>

#ifndef LINUX_VERSION_CODE	/* Very old kernel? */
#	define LINUX_VERSION_CODE 0
#endif

#if LINUX_VERSION_CODE >= 0x01031a /* <linux/scsi.h> introduced in 1.3.26 */
#if LINUX_VERSION_CODE >= 0x020000 /* <scsi/scsi.h> introduced somewhere. */
/* Need to fine tune the ifdef so we get the transition point right. */
#include <scsi/scsi.h>
#else
#include <linux/scsi.h>
#endif
#else
#define __KERNEL__
#include <linux/fs.h>
#undef __KERNEL__
#include "block/blk.h"
#include "scsi/scsi.h"
#endif

#include "scsi/sg.h"

/*
 *	Warning: you may change this source, but if you do that
 *	you need to change the _scg_version and _scg_auth* string below.
 *	You may not return "schily" for an SCG_AUTHOR request anymore.
 *	Choose your name instead of "schily" and make clear that the version
 *	string is related to a modified source.
 */
LOCAL	char	_scg_trans_version[] = "scsi-linux-sg.c-1.52";	/* The version for this transport*/

#ifndef	SCSI_IOCTL_GET_BUS_NUMBER
#define SCSI_IOCTL_GET_BUS_NUMBER 0x5386
#endif

/*
 * XXX There must be a better way than duplicating things from system include
 * XXX files. This is stolen from /usr/src/linux/drivers/scsi/scsi.h
 */
#ifndef	DID_OK
#define DID_OK          0x00 /* NO error                                */
#define DID_NO_CONNECT  0x01 /* Couldn't connect before timeout period  */
#define DID_BUS_BUSY    0x02 /* BUS stayed busy through time out period */
#define DID_TIME_OUT    0x03 /* TIMED OUT for other reason              */
#define DID_BAD_TARGET  0x04 /* BAD target.                             */
#define DID_ABORT       0x05 /* Told to abort for some other reason     */
#define DID_PARITY      0x06 /* Parity error                            */
#define DID_ERROR       0x07 /* Internal error                          */
#define DID_RESET       0x08 /* Reset by somebody.                      */
#define DID_BAD_INTR    0x09 /* Got an interrupt we weren't expecting.  */ 
#endif

/*
 *  These indicate the error that occurred, and what is available.
 */
#ifndef DRIVER_BUSY
#define DRIVER_BUSY         0x01
#define DRIVER_SOFT         0x02
#define DRIVER_MEDIA        0x03
#define DRIVER_ERROR        0x04
 
#define DRIVER_INVALID      0x05
#define DRIVER_TIMEOUT      0x06
#define DRIVER_HARD         0x07
#define DRIVER_SENSE        0x08
#endif

/*
 * XXX Should add extra space in buscookies and scgfiles for a "PP bus"
 * XXX and for two "ATAPI busses".
 */
#define	MAX_SCG		16	/* Max # of SCSI controllers */
#define	MAX_TGT		16
#define	MAX_LUN		8

struct scg_local {
	int	scgfile;		/* Used for SG_GET_BUFSIZE ioctl()*/
	short	scgfiles[MAX_SCG][MAX_TGT][MAX_LUN];
	short	buscookies[MAX_SCG];
	int	pgbus;
	int	pack_id;		/* Should be a random number	*/
	int	drvers;
	int	isold;
	long	xbufsize;
	char	*xbuf;
	char	*SCSIbuf;
};
#define scglocal(p)	((struct scg_local *)((p)->local)) 

#ifdef	SG_BIG_BUFF
#define	MAX_DMA_LINUX	SG_BIG_BUFF	/* Defined in include/scsi/sg.h	*/
#else
#define	MAX_DMA_LINUX	(4*1024)	/* Old Linux versions		*/
#endif

#ifndef	SG_MAX_SENSE
#	define	SG_MAX_SENSE	16	/* Too small for CCS / SCSI-2	*/
#endif					/* But cannot be changed	*/

#if	!defined(__i386) && !defined(i386) && !defined(mc68000)
#define	MISALIGN
#endif
/*#define	MISALIGN*/
/*#undef	SG_GET_BUFSIZE*/

#if	defined(USE_PG) && !defined(USE_PG_ONLY)
#include "scsi-linux-pg.c"
#endif

#ifdef	MISALIGN
LOCAL	int	scsi_getint	__PR((int *ip));
#endif
LOCAL	int	scsi_send	__PR((SCSI *scgp, int f, struct scg_cmd *sp));
#ifdef	SG_IO
LOCAL	int	scsi_rwsend	__PR((SCSI *scgp, int f, struct scg_cmd *sp));
#endif
LOCAL	BOOL	sg_setup	__PR((SCSI *scgp, int f, int busno, int tgt, int tlun));
LOCAL	void	sg_initdev	__PR((SCSI *scgp, int f));
LOCAL	int	sg_mapbus	__PR((SCSI *scgp, int busno, int ino));
LOCAL	BOOL	sg_mapdev	__PR((SCSI *scgp, int f, int *busp, int *tgtp, int *lunp,
							int *chanp, int *inop));
LOCAL	void	sg_settimeout	__PR((int f, int timeout));

/*
 * Return version information for the low level SCSI transport code.
 * This has been introduced to make it easier to trace down problems
 * in applications.
 */
EXPORT char *
scg__version(scgp, what)
	SCSI	*scgp;
	int	what;
{
	if (scgp != (SCSI *)0) {
		switch (what) {

		case SCG_VERSION:
			return (_scg_trans_version);
		/*
		 * If you changed this source, you are not allowed to
		 * return "schily" for the SCG_AUTHOR request.
		 */
		case SCG_AUTHOR:
			return (_scg_auth_schily);
		case SCG_SCCS_ID:
			return (__sccsid);
		}
	}
	return ((char *)0);
}

EXPORT int
scsi_open(scgp, device, busno, tgt, tlun)
	SCSI	*scgp;
	char	*device;
	int	busno;
	int	tgt;
	int	tlun;
{
	register int	f;
	register int	i;
	register int	b;
	register int	t;
	register int	l;
	register int	nopen = 0;
	char		devname[64];

	if (busno >= MAX_SCG || tgt >= MAX_TGT || tlun >= MAX_LUN) {
		errno = EINVAL;
		if (scgp->errstr)
			js_snprintf(scgp->errstr, SCSI_ERRSTR_SIZE,
				"Illegal value for busno, target or lun '%d,%d,%d'",
				busno, tgt, tlun);
		return (-1);
	}

	if (scgp->local == NULL) {
		scgp->local = malloc(sizeof(struct scg_local));
		if (scgp->local == NULL)
			return (0);

		scglocal(scgp)->scgfile = -1;
		scglocal(scgp)->pgbus = -2;
		scglocal(scgp)->SCSIbuf = (char *)-1;
		scglocal(scgp)->pack_id = 5;
		scglocal(scgp)->drvers = -1;
		scglocal(scgp)->isold = -1;
		scglocal(scgp)->xbufsize = 0L;
		scglocal(scgp)->xbuf = NULL;

		for (b=0; b < MAX_SCG; b++) {
			scglocal(scgp)->buscookies[b] = (short)-1;
			for (t=0; t < MAX_TGT; t++) {
				for (l=0; l < MAX_LUN ; l++)
					scglocal(scgp)->scgfiles[b][t][l] = (short)-1;
			}
		}
	}

	if ((device != NULL && *device != '\0') || (busno == -2 && tgt == -2))
		goto openbydev;

	for (i=0; i < 32; i++) {
		sprintf(devname, "/dev/sg%d", i);
		f = open(devname, 2);
		if (f < 0) {
			if (errno != ENOENT && errno != ENXIO && errno != ENODEV) {
				if (scgp->errstr)
					js_snprintf(scgp->errstr, SCSI_ERRSTR_SIZE,
							"Cannot open '%s'", devname);
				return (0);
			}
		} else {
			if (sg_setup(scgp, f, busno, tgt, tlun))
				return (++nopen);
			if (busno < 0 && tgt < 0 && tlun < 0)
				nopen++;
		}
	}
	if (nopen == 0) for (i=0; i <= 25; i++) {
		sprintf(devname, "/dev/sg%c", i+'a');
		f = open(devname, 2);
		if (f < 0) {
			if (errno != ENOENT && errno != ENXIO && errno != ENODEV) {
				if (scgp->errstr)
					js_snprintf(scgp->errstr, SCSI_ERRSTR_SIZE,
						"Cannot open '%s'", devname);
				return (0);
			}
		} else {
			if (sg_setup(scgp, f, busno, tgt, tlun))
				return (++nopen);
			if (busno < 0 && tgt < 0 && tlun < 0)
				nopen++;
		}
	}
openbydev:
	if (device != NULL && *device != '\0') {
		f = open(device, 2);
		if (f < 0 && errno == ENOENT)
			goto openpg;

		if (f < 0) {
			if (scgp->errstr)
				js_snprintf(scgp->errstr, SCSI_ERRSTR_SIZE,
					"Cannot open '%s'",
					device);
			return (0);
		}

		if (!sg_mapdev(scgp, f, &busno, &tgt, &tlun, 0, 0)) {
			close(f);
			goto openpg;
		}

		if (scgp->scsibus < 0)
			scgp->scsibus = busno;
		if (scgp->target < 0)
			scgp->target = tgt;
		if (scgp->lun < 0)
			scgp->lun = tlun;

		if (sg_setup(scgp, f, busno, tgt, tlun))
			return (++nopen);
	}
openpg:
#ifdef	USE_PG
	nopen += pg_open(scgp, device, busno, tgt, tlun);
#endif
	if (scgp->debug) for (b=0; b < MAX_SCG; b++) {
		printf("Bus: %d cookie: %X\n", b, scglocal(scgp)->buscookies[b]);
		for (t=0; t < MAX_TGT; t++) {
			for (l=0; l < MAX_LUN ; l++)
				if (scglocal(scgp)->scgfiles[b][t][l] != (short)-1)
					printf("file (%d,%d,%d): %d\n",
						b, t, l, scglocal(scgp)->scgfiles[b][t][l]);
		}
	}
	return (nopen);
}

EXPORT int
scsi_close(scgp)
	SCSI	*scgp;
{
	register int	f;
	register int	b;
	register int	t;
	register int	l;

	if (scgp->local == NULL)
		return (-1);

	for (b=0; b < MAX_SCG; b++) {
		if (b == scglocal(scgp)->pgbus)
			continue;
		scglocal(scgp)->buscookies[b] = (short)-1;
		for (t=0; t < MAX_TGT; t++) {
			for (l=0; l < MAX_LUN ; l++) {
				f = scglocal(scgp)->scgfiles[b][t][l];
				if (f >= 0)
					close(f);
				scglocal(scgp)->scgfiles[b][t][l] = (short)-1;
			}
		}
	}
	if (scglocal(scgp)->xbuf != NULL) {
		free(scglocal(scgp)->xbuf);
		scglocal(scgp)->xbufsize = 0L;
		scglocal(scgp)->xbuf = NULL;
	}
#ifdef	USE_PG
	pg_close(scgp);
#endif
	return (0);
}

LOCAL BOOL
sg_setup(scgp, f, busno, tgt, tlun)
	SCSI	*scgp;
	int	f;
	int	busno;
	int	tgt;
	int	tlun;
{
	int	n;
	int	Chan;
	int	Ino;
	int	Bus;
	int	Target;
	int	Lun;
	BOOL	onetarget = FALSE;

#ifdef	SG_GET_VERSION_NUM
	if (scglocal(scgp)->drvers < 0) {
		scglocal(scgp)->drvers = 0;
		if (ioctl(f, SG_GET_VERSION_NUM, &n) >= 0) {
			scglocal(scgp)->drvers = n;
			if (scgp->overbose)
				printf("Linux sg driver version: %d.%d.%d\n",
        				n/10000, (n%10000)/100, n%100);
		}
	}
#endif
	if (scgp->scsibus >= 0 && scgp->target >= 0 && scgp->lun >= 0)
		onetarget = TRUE;

	sg_mapdev(scgp, f, &Bus, &Target, &Lun, &Chan, &Ino);

	/*
	 * For old kernels try to make the best guess.
	 */
	Ino |= Chan << 8;
	n = sg_mapbus(scgp, Bus, Ino);
	if (Bus == -1) {
		Bus = n;