reactos/dll/appcompat/apphelp/sdbread.c

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/*
* PROJECT: ReactOS Application compatibility module
* LICENSE: GPL-2.0+ (https://spdx.org/licenses/GPL-2.0+)
* PURPOSE: Shim database query functions
* COPYRIGHT: Copyright 2011 André Hentschel
* Copyright 2013 Mislav Blaževic
* Copyright 2015-2018 Mark Jansen (mark.jansen@reactos.org)
*/
#include "windef.h"
#include "apphelp.h"
BOOL WINAPI SdbpReadData(PDB pdb, PVOID dest, DWORD offset, DWORD num)
{
DWORD size = offset + num;
/* Either overflow or no data to read */
if (size <= offset)
return FALSE;
/* Overflow */
if (pdb->size < size)
return FALSE;
memcpy(dest, pdb->data + offset, num);
return TRUE;
}
static DWORD WINAPI SdbpGetTagSize(PDB pdb, TAGID tagid)
{
WORD type;
DWORD size;
type = SdbGetTagFromTagID(pdb, tagid) & TAG_TYPE_MASK;
if (type == TAG_NULL)
return 0;
size = SdbGetTagDataSize(pdb, tagid);
if (type <= TAG_TYPE_STRINGREF)
return size += sizeof(TAG);
else size += (sizeof(TAG) + sizeof(DWORD));
return size;
}
LPWSTR WINAPI SdbpGetString(PDB pdb, TAGID tagid, PDWORD size)
{
TAG tag;
TAGID offset;
tag = SdbGetTagFromTagID(pdb, tagid);
if (tag == TAG_NULL)
return NULL;
if ((tag & TAG_TYPE_MASK) == TAG_TYPE_STRINGREF)
{
/* No stringtable; all references are invalid */
if (pdb->stringtable == TAGID_NULL)
return NULL;
/* TAG_TYPE_STRINGREF contains offset of string relative to stringtable */
if (!SdbpReadData(pdb, &tagid, tagid + sizeof(TAG), sizeof(TAGID)))
return NULL;
offset = pdb->stringtable + tagid + sizeof(TAG) + sizeof(TAGID);
}
else if ((tag & TAG_TYPE_MASK) == TAG_TYPE_STRING)
{
offset = tagid + sizeof(TAG) + sizeof(TAGID);
}
else
{
SHIM_ERR("Tag 0x%u at tagid %u is neither a string or reference to string\n", tag, tagid);
return NULL;
}
/* Optionally read string size */
if (size && !SdbpReadData(pdb, size, offset - sizeof(TAGID), sizeof(*size)))
return FALSE;
return (LPWSTR)(&pdb->data[offset]);
}
/**
* Searches shim database for the tag associated with specified tagid.
*
* @param [in] pdb Handle to the shim database.
* @param [in] tagid The TAGID of the tag.
*
* @return Success: The tag associated with specified tagid, Failure: TAG_NULL.
*/
TAG WINAPI SdbGetTagFromTagID(PDB pdb, TAGID tagid)
{
TAG data;
if (!SdbpReadData(pdb, &data, tagid, sizeof(data)))
return TAG_NULL;
return data;
}
/**
* Retrieves size of data at specified tagid.
*
* @param [in] pdb Handle to the shim database.
* @param [in] tagid Tagid of tag whose size is queried.
*
* @return Success: Size of data at specified tagid, Failure: 0.
*/
DWORD WINAPI SdbGetTagDataSize(PDB pdb, TAGID tagid)
{
/* sizes of data types with fixed size */
static const SIZE_T sizes[6] = {
0, /* NULL */ 1, /* BYTE */
2, /* WORD */ 4, /* DWORD */
8, /* QWORD */ 4 /* STRINGREF */
};
WORD type;
DWORD size;
type = SdbGetTagFromTagID(pdb, tagid) & TAG_TYPE_MASK;
if (type == TAG_NULL)
return 0;
if (type <= TAG_TYPE_STRINGREF)
return sizes[(type >> 12) - 1];
/* tag with dynamic size (e.g. list): must read size */
if (!SdbpReadData(pdb, &size, tagid + sizeof(TAG), sizeof(size)))
return 0;
return size;
}
/**
* Searches shim database for a child of specified parent tag.
*
* @param [in] pdb Handle to the shim database.
* @param [in] parent TAGID of parent.
*
* @return Success: TAGID of child tag, Failure: TAGID_NULL.
*/
TAGID WINAPI SdbGetFirstChild(PDB pdb, TAGID parent)
{
/* if we are at beginning of database */
if (parent == TAGID_ROOT)
{
/* header only database: no tags */
if (pdb->size <= _TAGID_ROOT)
return TAGID_NULL;
/* return *real* root tagid */
else return _TAGID_ROOT;
}
/* only list tag can have children */
if ((SdbGetTagFromTagID(pdb, parent) & TAG_TYPE_MASK) != TAG_TYPE_LIST)
return TAGID_NULL;
/* first child is sizeof(TAG) + sizeof(DWORD) bytes after beginning of list */
return parent + sizeof(TAG) + sizeof(DWORD);
}
/**
* Searches shim database for next child of specified parent tag.
*
* @param [in] pdb Handle to the shim database.
* @param [in] parent TAGID of parent.
* @param [in] prev_child TAGID of previous child.
*
* @return Success: TAGID of next child tag, Failure: TAGID_NULL.
*/
TAGID WINAPI SdbGetNextChild(PDB pdb, TAGID parent, TAGID prev_child)
{
TAGID next_child;
DWORD prev_child_size, parent_size;
prev_child_size = SdbpGetTagSize(pdb, prev_child);
if (prev_child_size == 0)
return TAGID_NULL;
/* Bound check */
next_child = prev_child + prev_child_size;
if (next_child >= pdb->size)
return TAGID_NULL;
if (parent == TAGID_ROOT)
return next_child;
parent_size = SdbpGetTagSize(pdb, parent);
if (parent_size == 0)
return TAGID_NULL;
/* Specified parent has no more children */
if (next_child >= parent + parent_size)
return TAGID_NULL;
return next_child;
}
/**
* Searches shim database for a tag within specified domain.
*
* @param [in] pdb Handle to the shim database.
* @param [in] parent TAGID of parent.
* @param [in] tag TAG to be located.
*
* @return Success: TAGID of first matching tag, Failure: TAGID_NULL.
*/
TAGID WINAPI SdbFindFirstTag(PDB pdb, TAGID parent, TAG tag)
{
TAGID iter;
iter = SdbGetFirstChild(pdb, parent);
while (iter != TAGID_NULL)
{
if (SdbGetTagFromTagID(pdb, iter) == tag)
return iter;
iter = SdbGetNextChild(pdb, parent, iter);
}
return TAGID_NULL;
}
/**
* Searches shim database for a next tag which matches prev_child within parent's domain.
*
* @param [in] pdb Handle to the shim database.
* @param [in] parent TAGID of parent.
* @param [in] prev_child TAGID of previous match.
*
* @return Success: TAGID of next match, Failure: TAGID_NULL.
*/
TAGID WINAPI SdbFindNextTag(PDB pdb, TAGID parent, TAGID prev_child)
{
TAG tag;
TAGID iter;
tag = SdbGetTagFromTagID(pdb, prev_child);
iter = SdbGetNextChild(pdb, parent, prev_child);
while (iter != TAGID_NULL)
{
if (SdbGetTagFromTagID(pdb, iter) == tag)
return iter;
iter = SdbGetNextChild(pdb, parent, iter);
}
return TAGID_NULL;
}
/**
* Searches shim database for string associated with specified tagid and copies string into a
* buffer.
*
* If size parameter is less than number of characters in string, this function shall fail and
* no data shall be copied.
*
* @param [in] pdb Handle to the shim database.
* @param [in] tagid TAGID of string or stringref associated with the string.
* @param [out] buffer Buffer in which string will be copied.
* @param [in] size Number of characters to copy.
*
* @return TRUE if string was successfully copied to the buffer FALSE if string was not copied
* to the buffer.
*/
BOOL WINAPI SdbReadStringTag(PDB pdb, TAGID tagid, LPWSTR buffer, DWORD size)
{
LPWSTR string;
DWORD string_size;
string = SdbpGetString(pdb, tagid, &string_size);
if (!string)
return FALSE;
/* Check if buffer is too small */
if (size * sizeof(WCHAR) < string_size)
return FALSE;
memcpy(buffer, string, string_size);
return TRUE;
}
/**
* Reads WORD value at specified tagid.
*
* @param [in] pdb Handle to the shim database.
* @param [in] tagid TAGID of WORD value.
* @param [in] ret Default return value in case function fails.
*
* @return Success: WORD value at specified tagid, or ret on failure.
*/
WORD WINAPI SdbReadWORDTag(PDB pdb, TAGID tagid, WORD ret)
{
if (SdbpCheckTagIDType(pdb, tagid, TAG_TYPE_WORD))
SdbpReadData(pdb, &ret, tagid + 2, sizeof(WORD));
return ret;
}
/**
* Reads DWORD value at specified tagid.
*
* @param [in] pdb Handle to the shim database.
* @param [in] tagid TAGID of DWORD value.
* @param [in] ret Default return value in case function fails.
*
* @return Success: DWORD value at specified tagid, otherwise ret.
*/
DWORD WINAPI SdbReadDWORDTag(PDB pdb, TAGID tagid, DWORD ret)
{
if (SdbpCheckTagIDType(pdb, tagid, TAG_TYPE_DWORD))
SdbpReadData(pdb, &ret, tagid + 2, sizeof(DWORD));
return ret;
}
/**
* Reads QWORD value at specified tagid.
*
* @param [in] pdb Handle to the shim database.
* @param [in] tagid TAGID of QWORD value.
* @param [in] ret Default return value in case function fails.
*
* @return Success: QWORD value at specified tagid, otherwise ret.
*/
QWORD WINAPI SdbReadQWORDTag(PDB pdb, TAGID tagid, QWORD ret)
{
if (SdbpCheckTagIDType(pdb, tagid, TAG_TYPE_QWORD))
SdbpReadData(pdb, &ret, tagid + sizeof(TAG), sizeof(QWORD));
return ret;
}
/**
* Reads binary data at specified tagid.
*
* @param [in] pdb Handle to the shim database.
* @param [in] tagid TAGID of binary data.
* @param [out] buffer Buffer in which data will be copied.
* @param [in] size Size of the buffer.
*
* @return TRUE if data was successfully written, or FALSE otherwise.
*/
BOOL WINAPI SdbReadBinaryTag(PDB pdb, TAGID tagid, PBYTE buffer, DWORD size)
{
DWORD data_size = 0;
if (SdbpCheckTagIDType(pdb, tagid, TAG_TYPE_BINARY))
{
SdbpReadData(pdb, &data_size, tagid + sizeof(TAG), sizeof(data_size));
if (size >= data_size)
return SdbpReadData(pdb, buffer, tagid + sizeof(TAG) + sizeof(data_size), data_size);
}
return FALSE;
}
/**
* Retrieves binary data at specified tagid.
*
* @param [in] pdb Handle to the shim database.
* @param [in] tagid TAGID of binary data.
*
* @return Success: Pointer to binary data at specified tagid, or NULL on failure.
*/
PVOID WINAPI SdbGetBinaryTagData(PDB pdb, TAGID tagid)
{
if (!SdbpCheckTagIDType(pdb, tagid, TAG_TYPE_BINARY))
return NULL;
return &pdb->data[tagid + sizeof(TAG) + sizeof(DWORD)];
}
/**
* Searches shim database for string associated with specified tagid.
*
* @param [in] pdb Handle to the shim database.
* @param [in] tagid TAGID of string or stringref associated with the string.
*
* @return the LPWSTR associated with specified tagid, or NULL on failure.
*/
LPWSTR WINAPI SdbGetStringTagPtr(PDB pdb, TAGID tagid)
{
return SdbpGetString(pdb, tagid, NULL);
}
/**
* Reads binary data at specified tagid.
*
* @param [in] pdb Handle to the shim database.
* @param [out] Guid Database ID.
*
* @return true if the ID was found FALSE otherwise.
*/
BOOL WINAPI SdbGetDatabaseID(PDB pdb, GUID* Guid)
{
if(SdbIsNullGUID(&pdb->database_id))
{
TAGID root = SdbFindFirstTag(pdb, TAGID_ROOT, TAG_DATABASE);
if(root != TAGID_NULL)
{
TAGID id = SdbFindFirstTag(pdb, root, TAG_DATABASE_ID);
if(id != TAGID_NULL)
{
if(!SdbReadBinaryTag(pdb, id, (PBYTE)&pdb->database_id, sizeof(pdb->database_id)))
{
memset(&pdb->database_id, 0, sizeof(pdb->database_id));
}
}
else
{
/* Should we silence this if we are opening a system db? */
SHIM_ERR("Failed to get the database id\n");
}
}
else
{
/* Should we silence this if we are opening a system db? */
SHIM_ERR("Failed to get root tag\n");
}
}
if(!SdbIsNullGUID(&pdb->database_id))
{
memcpy(Guid, &pdb->database_id, sizeof(pdb->database_id));
return TRUE;
}
return FALSE;
}