udfs_rec.c File Reference

#include "fs_rec.h"
#include "udfs_rec.h"

Go to the source code of this file.

Defines
#define	Dbg   (FSREC_DEBUG_LEVEL_UDFS)
Functions
NTSTATUS	UdfsRecFsControl (IN PDEVICE_OBJECT DeviceObject, IN PIRP Irp)
BOOLEAN	IsUdfsVolume (IN PDEVICE_OBJECT DeviceObject, IN ULONG SectorSize)
ULONG	UdfsFindInParseTable (IN PPARSE_KEYVALUE ParseTable, IN PCHAR Id, IN ULONG MaxIdLen)
Variables
PARSE_KEYVALUE	VsdIdentParseTable []

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Define Documentation

#define Dbg   (FSREC_DEBUG_LEVEL_UDFS)

Definition at line 33 of file udfs_rec.c.

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Function Documentation

BOOLEAN IsUdfsVolume (  IN PDEVICE_OBJECT  DeviceObject, IN ULONG  SectorSize )

Definition at line 157 of file udfs_rec.c. References Dbg, DebugTrace, ExFreePool(), FALSE, FsRecReadBlock(), NULL, Offset, PAGED_CODE, PVSD_GENERIC, SectorAlignN, SectorSize, TRUE, UdfsFindInParseTable(), VRA_BOUNDARY_LOCATION, VSD_GENERIC, VSD_LENGTH_IDENT, VsdIdentBEA01, VsdIdentBOOT2, VsdIdentCD001, VsdIdentCDROM, VsdIdentCDW01, VsdIdentCDW02, VsdIdentNSR01, VsdIdentNSR02, VsdIdentParseTable, and VsdIdentTEA01. Referenced by UdfsRecFsControl(). : This routine walks the Volume Recognition Sequence to determine whether this volume contains an NSR02 (ISO 13346 Section 4) image. Note: this routine is pretty much diked out of UdfsRecognizeVolume in the real filesystem, modulo fitting it into the fs recognizer. Arguments: DeviceObject - device we are checking SectorSize - size of a physical sector on this device Return Value: Boolean TRUE if we found NSR02, FALSE otherwise. --*/ { BOOLEAN FoundNSR = FALSE; BOOLEAN FoundBEA = FALSE; BOOLEAN Resolved = FALSE; PVSD_GENERIC VolumeStructureDescriptor = NULL; ULONGLONG Offset = SectorAlignN( SectorSize, VRA_BOUNDARY_LOCATION ); PAGED_CODE(); DebugTrace(( +1, Dbg, "IsUdfsVolume, DevObj %08x SectorSize %08x\n", DeviceObject, SectorSize )); while (!Resolved) { if (!FsRecReadBlock( DeviceObject, (PLARGE_INTEGER)&Offset, sizeof(VSD_GENERIC), SectorSize, (PVOID) &VolumeStructureDescriptor, NULL )) { break; } // // Now check the type of the descriptor. All ISO 13346 VSDs are // of Type 0, 9660 PVDs are Type 1, 9660 SVDs are Type 2, and 9660 // terminating descriptors are Type 255. // if (VolumeStructureDescriptor->Type == 0) { // // In order to properly recognize the volume, we must know all of the // Structure identifiers in ISO 13346 so that we can terminate if a // badly formatted (or, shockingly, non 13346) volume is presented to us. // switch (UdfsFindInParseTable( VsdIdentParseTable, VolumeStructureDescriptor->Ident, VSD_LENGTH_IDENT )) { case VsdIdentBEA01: // // Only one BEA may exist and its version must be 1 (2/9.2.3) // DebugTrace(( 0, Dbg, "IsUdfsVolume, got a BEA01\n" )); if ((FoundBEA && DebugTrace(( 0, Dbg, "IsUdfsVolume, ... but it is a duplicate!\n" ))) || (VolumeStructureDescriptor->Version != 1 && DebugTrace(( 0, Dbg, "IsUdfsVolume, ... but it has a wacky version number %02x != 1!\n", VolumeStructureDescriptor->Version )))) { Resolved = TRUE; break; } FoundBEA = TRUE; break; case VsdIdentTEA01: // // If we reach the TEA it must be the case that we don't recognize // DebugTrace(( 0, Dbg, "IsUdfsVolume, got a TEA01\n" )); Resolved = TRUE; break; case VsdIdentNSR02: // // We recognize NSR02 version 1 embedded after a BEA (3/9.1.3). For // simplicity we will not bother being a complete nitpick and check // for a bounding TEA, although we will be optimistic in the case where // we fail to match the version. // DebugTrace(( 0, Dbg, "IsUdfsVolume, got an NSR02\n" )); if ((FoundBEA || !DebugTrace(( 0, Dbg, "IsUdfsVolume, ... but we haven't seen a BEA01 yet!\n" ))) && (VolumeStructureDescriptor->Version == 1 || !DebugTrace(( 0, Dbg, "IsUdfsVolume, ... but it has a wacky version number %02x != 1\n", VolumeStructureDescriptor->Version )))) { FoundNSR = Resolved = TRUE; break; } break; case VsdIdentCD001: case VsdIdentCDW01: case VsdIdentNSR01: case VsdIdentCDW02: case VsdIdentBOOT2: DebugTrace(( 0, Dbg, "IsUdfsVolume, got a valid but uninteresting 13346 descriptor\n" )); // // Valid but uninteresting (to us) descriptors // break; default: DebugTrace(( 0, Dbg, "IsUdfsVolume, got an invalid 13346 descriptor\n" )); // // Stumbling across something we don't know, it must be that this // is not a valid 13346 image // Resolved = TRUE; break; } } else if (!FoundBEA && (VolumeStructureDescriptor->Type < 3 || VolumeStructureDescriptor->Type == 255)) { DebugTrace(( 0, Dbg, "IsUdfsVolume, got a 9660 descriptor\n" )); // // Only HSG (CDROM) and 9660 (CD001) are possible, and they are only legal // before the ISO 13346 BEA/TEA extent. By design, an ISO 13346 VSD precisely // overlaps a 9660 PVD/SVD in the appropriate fields. // // Note that we aren't being strict about the structure of the 9660 descriptors // since that really isn't very interesting. We care more about the 13346. // // switch (UdfsFindInParseTable( VsdIdentParseTable, VolumeStructureDescriptor->Ident, VSD_LENGTH_IDENT )) { case VsdIdentCDROM: case VsdIdentCD001: DebugTrace(( 0, Dbg, "IsUdfsVolume, ... seems we have 9660 here\n" )); // // Note to our caller that we seem to have ISO 9660 here // break; default: DebugTrace(( 0, Dbg, "IsUdfsVolume, ... but it looks wacky\n" )); // // This probably was a false alert, but in any case there is nothing // on this volume for us. // Resolved = TRUE; break; } } else { // // Something else must be recorded on this volume. // DebugTrace(( 0, Dbg, "IsUdfsVolume, got an unrecognizeable descriptor, probably not 13346/9660\n" )); break; } // // Align our next read with the sector following the current descriptor // Offset += SectorAlignN( SectorSize, sizeof(VSD_GENERIC) ); } DebugTrace(( -1, Dbg, "IsUdfsVolume -> %c\n", ( FoundNSR ? 'T' : 'F' ))); // // Free up our temporary buffer // if (VolumeStructureDescriptor) { ExFreePool( VolumeStructureDescriptor ); } return FoundNSR; }

ULONG UdfsFindInParseTable (  IN PPARSE_KEYVALUE  ParseTable, IN PCHAR  Id, IN ULONG  MaxIdLen )

Definition at line 392 of file udfs_rec.c. References NULL, and PAGED_CODE. Referenced by IsUdfsVolume(). : This routine walks a table of string key/value information for a match of the input Id. MaxIdLen can be set to get a prefix match. Arguments: Table - This is the table being searched. Id - Key value. MaxIdLen - Maximum possible length of Id. Return Value: Value of matching entry, or the terminating (NULL) entry's value. --*/ { PAGED_CODE(); while (ParseTable->Key != NULL) { if (RtlEqualMemory(ParseTable->Key, Id, MaxIdLen)) { break; } ParseTable++; } return ParseTable->Value; }

NTSTATUS UdfsRecFsControl (  IN PDEVICE_OBJECT  DeviceObject, IN PIRP  Irp )

Definition at line 60 of file udfs_rec.c. References FsRecGetDeviceSectorSize(), FsRecLoadFileSystem(), IO_NO_INCREMENT, IoCompleteRequest, IoGetCurrentIrpStackLocation, _IRP::IoStatus, Irp, IRP_MN_LOAD_FILE_SYSTEM, IRP_MN_MOUNT_VOLUME, IsUdfsVolume(), L, _IO_STACK_LOCATION::MinorFunction, NTSTATUS(), PAGED_CODE, and _IO_STACK_LOCATION::Parameters. Referenced by FsRecFsControl(). : This function performs the mount and driver reload functions for this mini- file system recognizer driver. Arguments: DeviceObject - Pointer to this driver's device object. Irp - Pointer to the I/O Request Packet (IRP) representing the function to be performed. Return Value: The function value is the final status of the operation. -*/ { NTSTATUS status; PIO_STACK_LOCATION irpSp; PDEVICE_EXTENSION deviceExtension; UNICODE_STRING driverName; ULONG bytesPerSector; PDEVICE_OBJECT targetDevice; PAGED_CODE(); // // Begin by determining what function that is to be performed. // deviceExtension = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension; irpSp = IoGetCurrentIrpStackLocation( Irp ); switch ( irpSp->MinorFunction ) { case IRP_MN_MOUNT_VOLUME: // // Attempt to mount a volume: There are two different cases here: // // 1) The device is being opened for DASD access, that is, no // file system is required, thus it is OK to allow RAW to // to open it. // // 2) We need to rummage the media to see if this is a UDF volume. // status = STATUS_UNRECOGNIZED_VOLUME; targetDevice = irpSp->Parameters.MountVolume.DeviceObject; if (FsRecGetDeviceSectorSize( targetDevice, &bytesPerSector )) { if (IsUdfsVolume( targetDevice, bytesPerSector )) { status = STATUS_FS_DRIVER_REQUIRED; } } break; case IRP_MN_LOAD_FILE_SYSTEM: status = FsRecLoadFileSystem( DeviceObject, L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\Udfs" ); break; default: status = STATUS_INVALID_DEVICE_REQUEST; } // // Finally, complete the request and return the same status code to the // caller. // Irp->IoStatus.Status = status; IoCompleteRequest( Irp, IO_NO_INCREMENT ); return status; }

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Variable Documentation

PARSE_KEYVALUE VsdIdentParseTable[]

Initial value: { { VSD_IDENT_BEA01, VsdIdentBEA01 }, { VSD_IDENT_TEA01, VsdIdentTEA01 }, { VSD_IDENT_CDROM, VsdIdentCDROM }, { VSD_IDENT_CD001, VsdIdentCD001 }, { VSD_IDENT_CDW01, VsdIdentCDW01 }, { VSD_IDENT_CDW02, VsdIdentCDW02 }, { VSD_IDENT_NSR01, VsdIdentNSR01 }, { VSD_IDENT_NSR02, VsdIdentNSR02 }, { VSD_IDENT_BOOT2, VsdIdentBOOT2 }, { NULL, VsdIdentBad } } Definition at line 39 of file udfs_rec.c. Referenced by IsUdfsVolume(), and UdfRecognizeVolume().

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