util_win32.c

apache 安装教程 apache 安装教程

        }
    }
    *p = '\0';

    /*  Blow away any final trailing '.' since on Win32
     *  foo.bat == foo.bat. == foo.bat... etc.
     *  Also blow away any trailing spaces since
     *  "filename" == "filename "
     */
    q = p;
    while (p > pNewStr && (*(p-1) == '.' || *(p-1) == ' '))
        p--;
    if ((p > pNewStr) ||
        (p == pNewStr && q-p > 2))
        *p = '\0';
        

    /*  One more security issue to deal with.  Win32 allows
     *  you to create long filenames.  However, alias filenames
     *  are always created so that the filename will
     *  conform to 8.3 rules.  According to the Microsoft
     *  Developer's network CD (1/98) 
     *  "Automatically generated aliases are composed of the 
     *   first six characters of the filename plus ~n 
     *   (where n is a number) and the first three characters 
     *   after the last period."
     *  Here, we attempt to detect and decode these names.
     *
     *  XXX: Netware network clients may have alternate short names,
     *  simply truncated, with no embedded '~'.  Further, this behavior
     *  can be modified on WinNT volumes.  This was not a safe test,
     *  therefore exclude the '~' pretest.
     */
#ifdef WIN32_SHORT_FILENAME_INSECURE_BEHAVIOR
     p = strchr(pNewStr, '~');
     if (p != NULL)
#endif
    /* ap_os_systemcase_filename now changes the case of only
     * the pathname elements that are found.
     */
        pNewStr = ap_os_systemcase_filename(pPool, pNewStr);

    return pNewStr;
}

/*  Perform complete canonicalization.
 */
API_EXPORT(char *) ap_os_canonical_filename(pool *pPool, const char *szFile)
{
    char *pNewName;
    pNewName = ap_os_case_canonical_filename(pPool, szFile);
    strlwr(pNewName);
    return pNewName;
}


/*
 * ap_os_is_filename_valid is given a filename, and returns 0 if the filename
 * is not valid for use on this system. On Windows, this means it fails any
 * of the tests below. Otherwise returns 1.
 *
 * Test for filename validity on Win32. This is of tests come in part from
 * the MSDN article at "Technical Articles, Windows Platform, Base Services,
 * Guidelines, Making Room for Long Filenames" although the information
 * in MSDN about filename testing is incomplete or conflicting. There is a
 * similar set of tests in "Technical Articles, Windows Platform, Base Services,
 * Guidelines, Moving Unix Applications to Windows NT".
 *
 * The tests are:
 *
 * 1) total path length greater than MAX_PATH
 *
 * 2) anything using the octets 0-31 or characters " < > | :
 *    (these are reserved for Windows use in filenames. In addition
 *     each file system has its own additional characters that are
 *     invalid. See KB article Q100108 for more details).
 *
 * 3) anything ending in "." (no matter how many)
 *    (filename doc, doc. and doc... all refer to the same file)
 *
 * 4) any segment in which the basename (before first period) matches
 *    one of the DOS device names
 *    (the list comes from KB article Q100108 although some people
 *     reports that additional names such as "COM5" are also special
 *     devices).
 *
 * If the path fails ANY of these tests, the result must be to deny access.
 */

API_EXPORT(int) ap_os_is_filename_valid(const char *file)
{
    const char *segstart;
    unsigned int seglength;
    const char *pos;
    static const char * const invalid_characters = "?\"<>*|:";
    static const char * const invalid_filenames[] = { 
	"CON", "AUX", "COM1", "COM2", "COM3", 
	"COM4", "LPT1", "LPT2", "LPT3", "PRN", "NUL", NULL 
    };

    /* Test 1 */
    if (strlen(file) >= MAX_PATH) {
	/* Path too long for Windows. Note that this test is not valid
	 * if the path starts with //?/ or \\?\. */
	return 0;
    }

    pos = file;

    /* Skip any leading non-path components. This can be either a
     * drive letter such as C:, or a UNC path such as \\SERVER\SHARE\.
     * We continue and check the rest of the path based on the rules above.
     * This means we could eliminate valid filenames from servers which
     * are not running NT (such as Samba).
     */

    if (pos[0] && pos[1] == ':') {
	/* Skip leading drive letter */
	pos += 2;
    }
    else {
	if ((pos[0] == '\\' || pos[0] == '/') &&
	    (pos[1] == '\\' || pos[1] == '/')) {
	    /* Is a UNC, so skip the server name and share name */
	    pos += 2;
	    while (*pos && *pos != '/' && *pos != '\\')
		pos++;
	    if (!*pos) {
		/* No share name */
		return 0;
	    }
	    pos++;	/* Move to start of share name */
	    while (*pos && *pos != '/' && *pos != '\\')
		pos++;
	    if (!*pos) {
		/* No path information */
		return 0;
	    }
	}
    }

    while (*pos) {
	unsigned int idx;
	unsigned int baselength;

	while (*pos == '/' || *pos == '\\') {
    	    pos++;
	}
	if (*pos == '\0') {
	    break;
	}
	segstart = pos;	/* start of segment */
	while (*pos && *pos != '/' && *pos != '\\') {
	    pos++;
	}
	seglength = pos - segstart;
	/* 
	 * Now we have a segment of the path, starting at position "segstart"
	 * and length "seglength"
	 */

	/* Test 2 */
	for (idx = 0; idx < seglength; idx++) {
	    if ((segstart[idx] > 0 && segstart[idx] < 32) ||
		strchr(invalid_characters, segstart[idx])) {
		return 0;
	    }
	}

	/* Test 3 */
	if (segstart[seglength-1] == '.') {
	    return 0;
	}

	/* Test 4 */
	for (baselength = 0; baselength < seglength; baselength++) {
	    if (segstart[baselength] == '.') {
		break;
	    }
	}

	/* baselength is the number of characters in the base path of
	 * the segment (which could be the same as the whole segment length,
	 * if it does not include any dot characters). */
	if (baselength == 3 || baselength == 4) {
	    for (idx = 0; invalid_filenames[idx]; idx++) {
		if (strlen(invalid_filenames[idx]) == baselength &&
		    !strnicmp(invalid_filenames[idx], segstart, baselength)) {
		    return 0;
		}
	    }
	}
    }

    return 1;
}


API_EXPORT(ap_os_dso_handle_t) ap_os_dso_load(const char *module_name)
{
    UINT em;
    ap_os_dso_handle_t dsoh;
    char path[MAX_PATH], *p;
    /* Load the module...
     * per PR2555, the LoadLibraryEx function is very picky about slashes.
     * Debugging on NT 4 SP 6a reveals First Chance Exception within NTDLL.
     * LoadLibrary in the MS PSDK also reveals that it -explicitly- states
     * that backslashes must be used.
     *
     * Transpose '\' for '/' in the filename.
     */
    ap_cpystrn(path, module_name, MAX_PATH);
    p = path;
    while (p = strchr(p, '/'))
        *p = '\\';
    
    /* First assume the dso/dll's required by -this- dso are sitting in the 
     * same path or can be found in the usual places.  Failing that, let's
     * let that dso look in the apache root.
     */
    em = SetErrorMode(SEM_FAILCRITICALERRORS);
    dsoh = LoadLibraryEx(path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
    if (!dsoh) {
        dsoh = LoadLibraryEx(path, NULL, 0);
    }
    SetErrorMode(em);
    return dsoh;
}

API_EXPORT(const char *) ap_os_dso_error(void)
{
    int len, nErrorCode;
    static char errstr[120];
    /* This is -not- threadsafe code, but it's about the best we can do.
     * mostly a potential problem for isapi modules, since LoadModule
     * errors are handled within a single config thread.
     */
    
    nErrorCode = GetLastError();
    len = ap_snprintf(errstr, sizeof(errstr), "(%d) ", nErrorCode);

    len += FormatMessage( 
            FORMAT_MESSAGE_FROM_SYSTEM,
            NULL,
            nErrorCode,
            MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), /* Default language */
            (LPTSTR) errstr + len,
            sizeof(errstr) - len,
            NULL 
        );
        /* FormatMessage may have appended a newline (\r\n). So remove it 
         * and use ": " instead like the Unix errors. The error may also
         * end with a . before the return - if so, trash it.
         */
    if (len > 1 && errstr[len-2] == '\r' && errstr[len-1] == '\n') {
        if (len > 2 && errstr[len-3] == '.')
            len--;
        errstr[len-2] = ':';
        errstr[len-1] = ' ';
    }
    return errstr;
}

#endif /* WIN32 */