From: Jeremy Drake <cygwin@jdrake.com>
To: cygwin-patches@cygwin.com
Subject: [PATCH v3] Cygwin: respect PC_SYM_FOLLOW and PC_SYM_NOFOLLOW_REP with inner links
Date: Thu, 3 Jun 2021 13:29:32 -0700 (PDT) [thread overview]
Message-ID: <alpine.BSO.2.21.2106031321380.30039@resin.csoft.net> (raw)
In-Reply-To: <YLSYIC/yYFz2IdMS@calimero.vinschen.de>
[-- Attachment #1: Type: text/plain, Size: 344 bytes --]
Just updated for formatting.
> Formatting should try to stick to 80 chars max line length, if possible.
> Kind of like this, just with TABs:
>
> - for (unsigned pc_flags = opt & (PC_NO_ACCESS_CHECK | PC_KEEP_HANDLE);
> + for (unsigned pc_flags = opt & (PC_NO_ACCESS_CHECK | PC_KEEP_HANDLE
> | PC_SYM_FOLLOW | PC_SYM_NOFOLLOW_REP);
>
[-- Attachment #2: Type: text/plain, Size: 1216 bytes --]
From 4bb959b57606465d5a7abe7d3ae168db66f5f6fa Mon Sep 17 00:00:00 2001
From: Jeremy Drake <cygwin@jdrake.com>
Date: Sat, 29 May 2021 13:17:08 -0700
Subject: [PATCH 1/2] Revert "Cygwin: Handle virtual drives as non-symlinks"
This reverts commit c8949d04001e3dbc03651475b6cd1c5623400835.
---
winsup/cygwin/path.cc | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 6a07f0d06..e62f8fe2b 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -3505,9 +3505,14 @@ restart:
subst X: C:\foo\bar
- Treat it as a normal file. */
+ Treat it like a symlink. This is required to tell an
+ lstat caller that the "drive" is actually pointing
+ somewhere else, thus, it's a symlink in POSIX speak. */
if (upath.Length == 14) /* \??\X:\ */
- goto file_not_symlink;
+ {
+ fileattr &= ~FILE_ATTRIBUTE_DIRECTORY;
+ path_flags |= PATH_SYMLINK;
+ }
/* For final paths differing in inner path components return
length as negative value. This informs path_conv::check
to skip realpath handling on the last path component. */
--
2.31.1.windows.1
[-- Attachment #3: Type: text/plain, Size: 2278 bytes --]
From ea36ccb13b2080663535d867e6fe8edf246efe83 Mon Sep 17 00:00:00 2001
From: Jeremy Drake <github@jdrake.com>
Date: Sat, 29 May 2021 11:48:11 -0700
Subject: [PATCH 2/2] Cygwin: respect PC_SYM_FOLLOW and PC_SYM_NOFOLLOW_REP
with inner links.
The new GetFinalPathNameW handling for native symlinks in inner path
components is disabled if caller doesn't want to follow symlinks, or
doesn't want to follow reparse points. Set flag to not follow reparse
points in chdir, allowing native processes to see their cwd potentially
including native symlinks, rather than dereferencing them.
---
winsup/cygwin/path.cc | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index e62f8fe2b..a6bb3aeff 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -722,9 +722,10 @@ path_conv::check (const char *src, unsigned opt,
int symlen = 0;
/* Make sure to check certain flags on last component only. */
- for (unsigned pc_flags = opt & (PC_NO_ACCESS_CHECK | PC_KEEP_HANDLE);
+ for (unsigned pc_flags = opt & (PC_NO_ACCESS_CHECK | PC_KEEP_HANDLE
+ | PC_SYM_FOLLOW | PC_SYM_NOFOLLOW_REP);
;
- pc_flags = 0)
+ pc_flags = opt & (PC_SYM_FOLLOW | PC_SYM_NOFOLLOW_REP))
{
const suffix_info *suff;
char *full_path;
@@ -3452,6 +3453,8 @@ restart:
break;
}
+ if ((pc_flags & (PC_SYM_FOLLOW | PC_SYM_NOFOLLOW_REP)) == PC_SYM_FOLLOW)
+ {
/* Check if the inner path components contain native symlinks or
junctions, or if the drive is a virtual drive. Compare incoming
path with path returned by GetFinalPathNameByHandleA. If they
@@ -3522,6 +3525,7 @@ restart:
}
}
}
+ }
/* Normal file. */
file_not_symlink:
@@ -3704,7 +3708,8 @@ chdir (const char *in_dir)
/* Convert path. PC_NONULLEMPTY ensures that we don't check for
NULL/empty/invalid again. */
- path_conv path (in_dir, PC_SYM_FOLLOW | PC_POSIX | PC_NONULLEMPTY);
+ path_conv path (in_dir, PC_SYM_FOLLOW | PC_POSIX | PC_NONULLEMPTY
+ | PC_SYM_NOFOLLOW_REP);
if (path.error)
{
set_errno (path.error);
--
2.31.1.windows.1
next prev parent reply other threads:[~2021-06-03 20:29 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-29 20:34 [PATCH] Cygwin: tweak handling of native symlinks from chdir Jeremy Drake
2021-05-29 23:15 ` Jeremy Drake
2021-05-30 6:05 ` Jeremy Drake
2021-05-30 19:58 ` [PATCH v2] Cygwin: respect PC_SYM_FOLLOW and PC_SYM_NOFOLLOW_REP with inner links Jeremy Drake
2021-05-31 8:02 ` Corinna Vinschen
2021-05-31 8:17 ` Corinna Vinschen
2021-05-31 17:55 ` Jeremy Drake
2021-07-03 21:01 ` Jeremy Drake
2021-07-07 18:52 ` Jeremy Drake
2021-07-08 14:48 ` Corinna Vinschen
2021-06-03 20:29 ` Jeremy Drake [this message]
2021-06-03 20:57 ` [PATCH v3] " Jeremy Drake
2021-07-06 14:57 ` Corinna Vinschen
2021-07-06 17:38 ` Jeremy Drake
2021-07-06 17:40 ` [PATCH v4] " Jeremy Drake
2021-07-07 8:47 ` Corinna Vinschen
2021-07-07 6:50 ` [PATCH v3] " Jeremy Drake
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.BSO.2.21.2106031321380.30039@resin.csoft.net \
--to=cygwin@jdrake.com \
--cc=cygwin-patches@cygwin.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).