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[newlib-cygwin] cygwin: try unprivileged symlink creation on W10 1703 and later
- From: Corinna Vinschen <corinna at sourceware dot org>
- To: cygwin-cvs at sourceware dot org
- Date: 24 Apr 2017 15:17:49 -0000
- Subject: [newlib-cygwin] cygwin: try unprivileged symlink creation on W10 1703 and later
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=ffcfbf4b66904529635d0b85687a1be48392ca15
commit ffcfbf4b66904529635d0b85687a1be48392ca15
Author: Corinna Vinschen <corinna@vinschen.de>
Date: Mon Apr 24 17:17:29 2017 +0200
cygwin: try unprivileged symlink creation on W10 1703 and later
Add new SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE flag to
CreateSymbolicLinkW call when running on W10 1703 or later.
Don't do that on older versions to avoid ERROR_INVALID_PARAMETER.
Preliminary, needs testing. There's an off-chance that the
flag results in the same ERROR_INVALID_PARAMETER on 1703 if the
developer settings are not enabled.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Diff:
---
winsup/cygwin/path.cc | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 16de025..7d1d23d 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -1621,6 +1621,10 @@ cnt_bs (PWCHAR s, PWCHAR e)
return num;
}
+#ifndef SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE
+#define SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE 2
+#endif
+
static int
symlink_native (const char *oldpath, path_conv &win32_newpath)
{
@@ -1628,6 +1632,7 @@ symlink_native (const char *oldpath, path_conv &win32_newpath)
path_conv win32_oldpath;
PUNICODE_STRING final_oldpath, final_newpath;
UNICODE_STRING final_oldpath_buf;
+ DWORD flags;
if (isabspath (oldpath))
{
@@ -1724,9 +1729,11 @@ symlink_native (const char *oldpath, path_conv &win32_newpath)
final_oldpath->Buffer[1] = L'\\';
}
/* Try to create native symlink. */
+ flags = win32_oldpath.isdir () ? SYMBOLIC_LINK_FLAG_DIRECTORY : 0;
+ if (wincap.has_unprivileged_createsymlink ())
+ flags |= SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE;
if (!CreateSymbolicLinkW (final_newpath->Buffer, final_oldpath->Buffer,
- win32_oldpath.isdir ()
- ? SYMBOLIC_LINK_FLAG_DIRECTORY : 0))
+ flags))
{
/* Repair native newpath, we still need it. */
final_newpath->Buffer[1] = L'?';