From 26425142ce9e8981e9f97e7d50e632c4f9ee9a03 Mon Sep 17 00:00:00 2001 From: Corinna Vinschen Date: Tue, 28 Jan 2020 17:40:40 +0100 Subject: [PATCH] Cygwin: path_conv: add PC_SYM_NOFOLLOW_DIR flag Usually a trailing slash requires to follow an existing symlink, even with PC_SYM_NOFOLLOW. The reason is that "foo/" is equivalent to "foo/." so the symlink is in fact not the last path component, "." is. This is default for almost all scenarios. PC_SYM_NOFOLLOW_DIR now allows the caller to request not to follow the symlink even if a trailing slash is given. This can be used in callers to perform certain functions Linux-compatible. Signed-off-by: Corinna Vinschen --- winsup/cygwin/path.cc | 27 ++++++++++++++++++++------- winsup/cygwin/path.h | 1 + 2 files changed, 21 insertions(+), 7 deletions(-) diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc index a00270210..5ebbddf3a 100644 --- a/winsup/cygwin/path.cc +++ b/winsup/cygwin/path.cc @@ -1022,20 +1022,33 @@ path_conv::check (const char *src, unsigned opt, these operations again on the newly derived path. */ else if (symlen > 0) { - if (component == 0 && !need_directory + if (component == 0 && (!(opt & PC_SYM_FOLLOW) || (is_known_reparse_point () && (opt & PC_SYM_NOFOLLOW_REP)))) { - /* last component of path is a symlink. */ - set_symlink (symlen); - if (opt & PC_SYM_CONTENTS) + /* Usually a trailing slash requires to follow a symlink, + even with PC_SYM_NOFOLLOW. The reason is that "foo/" + is equivalent to "foo/." so the symlink is in fact not + the last path component. + + PC_SYM_NOFOLLOW_DIR is used to indicate that the + last path component is the target symlink and the + trailing slash is supposed to be ignored. */ + if (!need_directory || (opt & PC_SYM_NOFOLLOW_DIR)) { - strcpy (THIS_path, sym.contents); + /* last component of path is a symlink. */ + set_symlink (symlen); + /* make sure not to set errno to ENOTDIR. */ + need_directory = 0; + if (opt & PC_SYM_CONTENTS) + { + strcpy (THIS_path, sym.contents); + goto out; + } + add_ext = true; goto out; } - add_ext = true; - goto out; } /* Following a symlink we can't trust the collected filesystem information any longer. */ diff --git a/winsup/cygwin/path.h b/winsup/cygwin/path.h index 72f4bda43..7b89b03a7 100644 --- a/winsup/cygwin/path.h +++ b/winsup/cygwin/path.h @@ -59,6 +59,7 @@ enum pathconv_arg PC_SYM_NOFOLLOW_PROCFD = _BIT (11), /* allow /proc/PID/fd redirection */ PC_KEEP_HANDLE = _BIT (12), /* keep handle for later stat calls */ PC_NO_ACCESS_CHECK = _BIT (13), /* helper flag for error check */ + PC_SYM_NOFOLLOW_DIR = _BIT (14), /* don't follow a trailing slash */ PC_DONT_USE = _BIT (31) /* conversion to signed happens. */ }; -- 2.43.5