0
0
mirror of https://github.com/python/cpython.git synced 2024-11-28 16:45:42 +01:00
cpython/PC/import_nt.c
Barry Warsaw 58ab084ac6 PyWin_FindRegisteredModule(): Conversion of sprintf() to
PyOS_snprintf() for buffer overrun avoidance.
2001-11-28 21:03:37 +00:00

86 lines
2.4 KiB
C

/********************************************************************
import_nt.c
Win32 specific import code.
*/
#include "Python.h"
#include "osdefs.h"
#include <windows.h>
#include "importdl.h"
#include "malloc.h" /* for alloca */
/* a string loaded from the DLL at startup */
extern const char *PyWin_DLLVersionString;
FILE *PyWin_FindRegisteredModule(const char *moduleName,
struct filedescr **ppFileDesc,
char *pathBuf,
int pathLen)
{
char *moduleKey;
const char keyPrefix[] = "Software\\Python\\PythonCore\\";
const char keySuffix[] = "\\Modules\\";
#ifdef _DEBUG
/* In debugging builds, we _must_ have the debug version
* registered.
*/
const char debugString[] = "\\Debug";
#else
const char debugString[] = "";
#endif
struct filedescr *fdp = NULL;
FILE *fp;
HKEY keyBase = HKEY_CURRENT_USER;
int modNameSize;
long regStat;
/* Calculate the size for the sprintf buffer.
* Get the size of the chars only, plus 1 NULL.
*/
size_t bufSize = sizeof(keyPrefix)-1 +
strlen(PyWin_DLLVersionString) +
sizeof(keySuffix) +
strlen(moduleName) +
sizeof(debugString) - 1;
/* alloca == no free required, but memory only local to fn,
* also no heap fragmentation!
*/
moduleKey = alloca(bufSize);
PyOS_snprintf(moduleKey, bufSize,
"Software\\Python\\PythonCore\\%s\\Modules\\%s%s",
PyWin_DLLVersionString, moduleName, debugString);
modNameSize = pathLen;
regStat = RegQueryValue(keyBase, moduleKey, pathBuf, &modNameSize);
if (regStat != ERROR_SUCCESS) {
/* No user setting - lookup in machine settings */
keyBase = HKEY_LOCAL_MACHINE;
/* be anal - failure may have reset size param */
modNameSize = pathLen;
regStat = RegQueryValue(keyBase, moduleKey,
pathBuf, &modNameSize);
if (regStat != ERROR_SUCCESS)
return NULL;
}
/* use the file extension to locate the type entry. */
for (fdp = _PyImport_Filetab; fdp->suffix != NULL; fdp++) {
size_t extLen = strlen(fdp->suffix);
assert(modNameSize >= 0); /* else cast to size_t is wrong */
if ((size_t)modNameSize > extLen &&
strnicmp(pathBuf + ((size_t)modNameSize-extLen-1),
fdp->suffix,
extLen) == 0)
break;
}
if (fdp->suffix == NULL)
return NULL;
fp = fopen(pathBuf, fdp->mode);
if (fp != NULL)
*ppFileDesc = fdp;
return fp;
}