access.c

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/*
 * COPYRIGHT:        See COPYRIGHT.TXT
 * PROJECT:          Ext2 File System Driver for WinNT/2K/XP
 * FILE:             access.c
 * PROGRAMMER:       Matt Wu <mattwu@163.com>
 * HOMEPAGE:         http://www.ext2fsd.com
 * UPDATE HISTORY:
 */
 
/* INCLUDES *****************************************************************/
 
#include "ext2fs.h"
 
/* GLOBALS ***************************************************************/
 
extern PEXT2_GLOBAL Ext2Global;
 
/* DEFINITIONS *************************************************************/
 
int Ext2CheckInodeAccess(PEXT2_VCB Vcb, struct inode *in, int attempt)
{
    int granted = 0;
 
    uid_t uid = Vcb->uid;
    gid_t gid = Vcb->gid;
 
    if (IsFlagOn(Vcb->Flags, VCB_USER_EIDS)) {
        uid = Vcb->euid;
        gid = Vcb->egid;
    }
 
    if (!uid || uid == in->i_uid) {
        /* grant all access for inode owner or root */
        granted = Ext2FileCanRead | Ext2FileCanWrite | Ext2FileCanExecute;
    } else if (gid == in->i_gid) {
        if (Ext2IsGroupReadOnly(in->i_mode))
            granted = Ext2FileCanRead | Ext2FileCanExecute;
        else if (Ext2IsGroupWritable(in->i_mode))
            granted = Ext2FileCanRead | Ext2FileCanWrite | Ext2FileCanExecute;
    } else {
        if (Ext2IsOtherReadOnly(in->i_mode))
            granted = Ext2FileCanRead | Ext2FileCanExecute;
        else if (Ext2IsOtherWritable(in->i_mode))
            granted = Ext2FileCanRead | Ext2FileCanWrite | Ext2FileCanExecute;
 
    }
 
    return IsFlagOn(granted, attempt);
}
 
int Ext2CheckFileAccess(PEXT2_VCB Vcb, PEXT2_MCB Mcb, int attempt)
{
    return Ext2CheckInodeAccess(Vcb, &Mcb->Inode, attempt);
}