This patch adds support for drive mappings added with SUBST and NET USE.
Example: After
subst p: C:\Users\Public
net use t: \\larid\tmp
the test program now prints:
??? C:\ ??? NFTS local
??? P:\ C:\Users\Public NFTS local
??? T:\ \\larid\tmp NTFS remote
2025-03-19 Bruno Haible <br...@clisp.org>
mountlist: Improve implementation on native Windows.
* lib/mountlist.c (read_file_system_list) [_WIN32 && !__CYGWIN__]:
Return the mntroot of drives mapped by SUBST or NET USE.
diff --git a/lib/mountlist.c b/lib/mountlist.c
index 1385db43fd..23ebdf6750 100644
--- a/lib/mountlist.c
+++ b/lib/mountlist.c
@@ -1131,8 +1131,58 @@ read_file_system_list (bool need_fs_type)
/* Check if drive is remote. See:
<https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getdrivetypea>.
*/
me->me_remote = GetDriveType (mountdir) == DRIVE_REMOTE;
+ /* Here we could use
+ QueryDosDeviceW -> returns something like
'\Device\HarddiskVolume2'
+ GetVolumeNameForVolumeMountPointW -> return something like
'\\?\Volume{...}'
+ */
me->me_devname = NULL;
- me->me_mntroot = NULL;
+ {
+ /* Find the SUBST or NET USE mapping of the given drive.
+
<https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-querydosdevicew>
+ For testing of SUBST: <https://ss64.com/nt/subst.html>
+ For testing of NET USE:
<https://ss64.com/nt/net-use.html> */
+ wchar_t drive[3];
+ wchar_t mapping[MAX_PATH + 1];
+ drive[0] = L'A' + i;
+ drive[1] = L':';
+ drive[2] = L'\0';
+ DWORD mapping_len = QueryDosDeviceW (drive, mapping, sizeof
(mapping) / sizeof (mapping[0]));
+ if (mapping_len > 4 && wcsncmp (mapping, L"\\??\\", 4) == 0)
+ {
+ /* It's a SUBSTed drive. */
+ char subst_dir[MAX_PATH + 1];
+ size_t subst_dir_len = wcstombs (subst_dir, mapping + 4,
sizeof (subst_dir));
+ if (subst_dir_len > 0 && subst_dir_len <= MAX_PATH)
+ me->me_mntroot = xstrdup (subst_dir);
+ else
+ /* mapping is too long or not convertible to the
+ locale encoding. */
+ me->me_mntroot = NULL;
+ }
+ else if (mapping_len > 26
+ && wcsncmp (mapping,
L"\\Device\\LanmanRedirector\\;", 26) == 0)
+ {
+ wchar_t *next_backslash = wcschr (mapping + 26, L'\\');
+ if (next_backslash != NULL)
+ {
+ *--next_backslash = L'\\';
+ char share_dir[MAX_PATH + 1];
+ size_t share_dir_len = wcstombs (share_dir,
next_backslash, sizeof (share_dir));
+ if (share_dir_len > 0 && share_dir_len <= MAX_PATH)
+ me->me_mntroot = xstrdup (share_dir);
+ else
+ /* mapping is too long or not convertible to the
+ locale encoding. */
+ me->me_mntroot = NULL;
+ }
+ else
+ /* mapping does not have the expected form. */
+ me->me_mntroot = NULL;
+ }
+ else
+ /* It's neither a SUBSTed nor a NET USEd drive. */
+ me->me_mntroot = NULL;
+ }
me->me_dev = (dev_t) -1;
me->me_dummy = 0;
me->me_type = xstrdup (fs_name);
