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Diffstat (limited to 'private/ntos/nbt/vxd/fileio.c')
| -rw-r--r-- | private/ntos/nbt/vxd/fileio.c | 476 |
1 files changed, 476 insertions, 0 deletions
diff --git a/private/ntos/nbt/vxd/fileio.c b/private/ntos/nbt/vxd/fileio.c new file mode 100644 index 000000000..b319ce290 --- /dev/null +++ b/private/ntos/nbt/vxd/fileio.c @@ -0,0 +1,476 @@ +/*++ + +Copyright (c) 1991 Microsoft Corporation + +Module Name: + + fileio.c + +Abstract: + + This source implements a stdio-like facility. + +Author: + + Eric Chin (ericc) April 28, 1992 + John Ludeman (johnl) Oct 8, 1993 - Rewrote for Vxd + +Revision History: + +--*/ + +#include <nbtprocs.h> +#include "hosts.h" + +// +// The maximum line length for a file in the lmhosts file is 256 bytes for +// the Vxd +// +#define MAX_LMHOSTS_LINE 256 + +// +// The number of bytes we buffer on each read +// +#define LMHOSTS_READ_BUFF_SIZE 256 + +UCHAR GetNextChar( PLM_FILE pFile ) ; + +VOID RestoreOldData( PLM_FILE pFile ); + +BackupCurrentData( PLM_FILE pFile ); + +//******************* Pageable Routine Declarations **************** +#ifdef ALLOC_PRAGMA +#pragma CTEMakePageable(PAGE, LmCloseFile) +#pragma CTEMakePageable(PAGE, LmFgets) +#pragma CTEMakePageable(PAGE, GetNextChar) +#pragma CTEMakePageable(PAGE, LmOpenFile) +#pragma CTEMakePageable(PAGE, BackupCurrentData) +#pragma CTEMakePageable(PAGE, RestoreOldData) +#endif + +#ifdef CHICAGO +// +// In case of chicago, use only linear addresses (Allocate_Global_V86_Data_Area +// call is available only at init time, not if vnbt is load dynamically!) +// +#define pMappedFileBuff pFileBuff +#define pMappedFilePath pFilePath + +#else +// +// In case of snowball, this is the address of the V86 mapped memory for +// the file read buffer and lmhosts file path +// +PVOID pMappedFileBuff = NULL ; +PVOID pMappedFilePath = NULL ; +#endif + +// +// Linear address for file buffer and path (accessible from Vxd) +// +PUCHAR pFileBuff = NULL ; +PUCHAR pFilePath = NULL ; + + +/******************************************************************* + + NAME: VxdInitLmHostsSupport + + SYNOPSIS: This function just allocates memory to read the contents + of file into. + (trying to minimize on changes to snowball side of code + whic has already shipped: that's why this function!) + + ENTRY: pchLmHostPath - path to lmhosts file (not used here) + ulPathSize - size, in chars, of the path + + RETURNS: TRUE if it works, FALSE if it doesn't. + COMMENTS: This is Chicago version of the function. Snowball's + version is in vxdfile.asm + + HISTORY: + Koti Oct 10, 94 + +********************************************************************/ + +#ifdef CHICAGO +BOOL +VxdInitLmHostsSupport( PUCHAR pchLmHostPath, USHORT ulPathSize ) +{ + + USHORT Size; + + Size = ulPathSize + LMHOSTS_READ_BUFF_SIZE; + + pFileBuff = CTEAllocInitMem( Size ); + if (pFileBuff == NULL) + { + DbgPrint("VxdInitLmHostsSupport: failed to allocate memory") ; + return( FALSE ); + } + + pFilePath = pFileBuff + LMHOSTS_READ_BUFF_SIZE; + + return( TRUE ); + +} + +#endif +//---------------------------------------------------------------------------- + +NTSTATUS +LmCloseFile ( + IN PLM_FILE pfile + ) + +/*++ + +Routine Description: + + This function closes a file opened via LmOpenFile(), and frees its + LM_FILE object. + +Arguments: + + pfile - pointer to the LM_FILE object + +Return Value: + + An NTSTATUS value. + +--*/ + + +{ + CTEPagedCode(); + + CDbgPrint(DBGFLAG_LMHOST, "LmCloseFile entered\r\n") ; + CTEFreeMem( pfile->f_linebuffer ); + + VxdFileClose( pfile->f_handle ) ; + + CTEFreeMem(pfile); + + CDbgPrint(DBGFLAG_LMHOST, "LmCloseFile leaving\r\n") ; + return STATUS_SUCCESS ; + +} // LmCloseFile + + + +//---------------------------------------------------------------------------- + +PUCHAR +LmFgets ( + IN PLM_FILE pfile, + OUT int *nbytes + ) + +/*++ + +Routine Description: + + This function is vaguely similar to fgets(3). + + Starting at the current seek position, it reads through a newline + character, or the end of the file. If a newline is encountered, it + is replaced with a NULL character. + +Arguments: + + pfile - file to read from + nbytes - the number of characters read, excluding the NULL character + +Return Value: + + A pointer to the beginning of the line, or NULL if we are at or past + the end of the file. + +--*/ +{ + ULONG cbLine = 0 ; + UCHAR ch ; + BOOL fDone = FALSE ; + BOOL fEOL = FALSE ; + + + CTEPagedCode(); + + while ( TRUE ) + { + switch ( ch = GetNextChar( pfile )) + { + case '\n': // End of line + if ( !cbLine ) // If it's just a '\n' by itself, ignore it + continue ; + // + // Fall through + // + + case '\0': // End of file + pfile->f_linebuffer[cbLine] = '\0' ; + fDone = TRUE ; + fEOL = TRUE ; + break ; + + case '\r': // Ignore + continue ; + + default: + pfile->f_linebuffer[cbLine] = ch ; + if ( cbLine == (MAX_LMHOSTS_LINE-1) ) + { + pfile->f_linebuffer[cbLine--] = '\0' ; + fDone = TRUE ; + } + break ; + } + + if ( fDone ) + break ; + + cbLine++ ; + } + + // + // Scan till the end of this line + // + if ( !fEOL ) + { + while ( (ch = GetNextChar(pfile)) && ch != '\n' ) + ; + } + + if ( cbLine ) + { + (pfile->f_lineno)++ ; + *nbytes = cbLine ; + + CDbgPrint( DBGFLAG_LMHOST, "LmFgets returning \"") ; + CDbgPrint( DBGFLAG_LMHOST, pfile->f_linebuffer ) ; + CDbgPrint( DBGFLAG_LMHOST, "\", nbytes = 0x") ; + CDbgPrintNum( DBGFLAG_LMHOST, *nbytes ) ; + CDbgPrint( DBGFLAG_LMHOST, "\r\n") ; + + return pfile->f_linebuffer ; + } + + return NULL ; +} + +/******************************************************************* + + NAME: GetNextChar + + SYNOPSIS: Gets the next character from the file or the line buffer + + ENTRY: pFile - File we are operating on + + RETURNS: Next character or '\0' if at the end of file (or there is an + embedded '\0' in the file). + + NOTES: + +********************************************************************/ + +UCHAR GetNextChar( PLM_FILE pFile ) +{ + ULONG BytesRead ; + + CTEPagedCode(); + + if ( pFile->f_CurPos < pFile->f_EndOfData ) + return pFile->f_buffer[pFile->f_CurPos++] ; + + if ( pFile->f_EOF ) + return '\0' ; + + // + // We've reached the end of the buffer, get more data + // + BytesRead = VxdFileRead( pFile->f_handle, + LMHOSTS_READ_BUFF_SIZE, + pMappedFileBuff ) ; + pFile->f_CurPos = 0 ; + if ( BytesRead < LMHOSTS_READ_BUFF_SIZE ) + pFile->f_EOF = TRUE ; + + // + // If haven't hit the end of the file, return the next character + // + if ( (pFile->f_EndOfData = BytesRead) ) + return pFile->f_buffer[pFile->f_CurPos++] ; + + return '\0' ; +} + + + +//---------------------------------------------------------------------------- + +PLM_FILE +LmOpenFile ( + IN PUCHAR path + ) + +/*++ + +Routine Description: + + This function opens a file for use by LmFgets(). + +Arguments: + + path - a fully specified, complete path to the file. + +Return Value: + + A pointer to an LM_FILE object, or NULL if unsuccessful. + +Notes: + + The first time through, we map the lmhosts memory to vm memory and + allocate a read buffer and map that to VM memory. Note that this means + the path must not change and this routine is not reentrant!! + + The reason for this is because the mapping is an expensive operation + (and there isn't a way to unmap when using Map_Lin_To_VM_Addr). + +--*/ + + +{ + HANDLE handle; + PLM_FILE pfile; + PCHAR pLineBuff = CTEAllocMem( MAX_LMHOSTS_LINE ) ; + static int fInRoutine = 0 ; + + CTEPagedCode(); + + + if (fInRoutine++) + { + CDbgPrint( DBGFLAG_LMHOST, "exiting LmOpenFile: not reentrant!\r\n") ; + goto ErrorExit; // We're not reentrant + } + + CDbgPrint( DBGFLAG_LMHOST, "LmOpenFile entered\r\n") ; + + strcpy( pFilePath, path ) ; + + if ( !pLineBuff || !pFileBuff ) + goto ErrorExit ; + + handle = (HANDLE) VxdFileOpen( pMappedFilePath ) ; + + if ( handle == NULL ) + { + goto ErrorExit ; + } + + pfile = (PLM_FILE) CTEAllocMem( sizeof(LM_FILE) ); + + if (!pfile) + { + VxdFileClose( handle ) ; + goto ErrorExit ; + } + + pfile->f_handle = handle; + pfile->f_lineno = 0; + pfile->f_buffer = pFileBuff ; + pfile->f_linebuffer = pLineBuff ; + pfile->f_EndOfData = 0 ; + pfile->f_CurPos = 0 ; + pfile->f_EOF = FALSE ; + + CDbgPrint( DBGFLAG_LMHOST, "LmOpenFile returning\r\n") ; + + fInRoutine-- ; + + return pfile ; + +ErrorExit: + + fInRoutine--; + + if ( pLineBuff ) + CTEFreeMem( pLineBuff ) ; + + return NULL ; + +} // LmOpenFile + + +//---------------------------------------------------------------------------- + +BOOL +BackupCurrentData( PLM_FILE pFile ) + +/*++ + +Routine Description: + + This function backs up all the data from lmhosts file into another buffer + (which is allocated). + This function is called before opening the next file that we encountered + via #INCLUDE. Since the same buffer is used to store the VxdReadFile data, + we need to save this data. + +Arguments: + + pFile - LMfile pointer + +Return Value: + + TRUE if everything went ok + FALSE if memory couldn't be allocated + +--*/ +{ + + CTEPagedCode(); + + pFile->f_BackUp = CTEAllocMem( MAX_LMHOSTS_LINE ) ; + if (pFile->f_BackUp == NULL ) + { + return( FALSE ); + } + + CTEMemCopy( pFile->f_BackUp, pFile->f_buffer, LMHOSTS_READ_BUFF_SIZE ); + + return( TRUE ); +} + + +//---------------------------------------------------------------------------- + +VOID RestoreOldData( PLM_FILE pFile ) +/*++ + +Routine Description: + + This function restores all the data we backed up in BackupCurrentData + +Arguments: + + pFile - LMfile pointer + +Return Value: + + TRUE if everything went ok + FALSE if memory couldn't be allocated + +--*/ +{ + + CTEPagedCode(); + + CTEMemCopy( pFile->f_buffer, pFile->f_BackUp, LMHOSTS_READ_BUFF_SIZE ); + + CTEFreeMem( pFile->f_BackUp ) ; + +} + + |