[newlib-cygwin] Cygwin: add AF_UNIX reparse points to path handling

[Corinna Vinschen <corinna at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=aa467e6e3305a63a06161374d3ebb0c56f6c6193

commit aa467e6e3305a63a06161374d3ebb0c56f6c6193
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Thu Mar 1 16:54:57 2018 +0100

    Cygwin: add AF_UNIX reparse points to path handling
    
    * check_reparse_point_target returns a path flag mask, rather than
      just 1.  Return PATH_SYMLINK | PATH_REP for symlinks and directory
      mount points, PATH_SOCKET | PATH_REP for AF_UNIX sockets.
    
    * Define Cygwin AF_UNIX socket reparse tag and GUID in ntdll.h.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/ntdll.h |  3 +++
 winsup/cygwin/path.cc | 25 ++++++++++++++++++-------
 winsup/cygwin/path.h  |  3 ++-
 3 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/winsup/cygwin/ntdll.h b/winsup/cygwin/ntdll.h
index 0112349..b77fa39 100644
--- a/winsup/cygwin/ntdll.h
+++ b/winsup/cygwin/ntdll.h
@@ -10,6 +10,9 @@
 
 #include <w32api/ntstatus.h>
 
+/* Special values for Cygwin AF_UNIX socket reparse points. */
+#define IO_REPARSE_TAG_CYGUNIX	(0x00006375)
+#define CYGWIN_SOCKET_UUID	L"efc1714d-7b19-4407-bab3-c5b1f92cb88c"
 
 /* custom status code: */
 #define STATUS_ILLEGAL_DLL_PSEUDO_RELOCATION ((NTSTATUS) 0xe0000269)
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 025acd6..f608257 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -951,8 +951,9 @@ path_conv::check (const char *src, unsigned opt,
 		      return;
 		    }
 		  fileattr = sym.fileattr;
-		  dev.parse (FH_LOCAL);
+		  dev.parse ((sym.pflags & PATH_REP) ? FH_UNIX : FH_LOCAL);
 		  dev.setfs (1);
+		  path_flags = sym.pflags;
 		  goto out;
 		}
 
@@ -2329,7 +2330,7 @@ check_reparse_point_target (HANDLE h, bool remote, PREPARSE_DATA_BUFFER rp,
 		rp->SymbolicLinkReparseBuffer.SubstituteNameLength);
       if ((rp->SymbolicLinkReparseBuffer.Flags & SYMLINK_FLAG_RELATIVE) ||
           check_reparse_point_string (psymbuf))
-	return 1;
+	return PATH_SYMLINK | PATH_REP;
     }
   else if (!remote && rp->ReparseTag == IO_REPARSE_TAG_MOUNT_POINT)
     {
@@ -2350,7 +2351,16 @@ check_reparse_point_target (HANDLE h, bool remote, PREPARSE_DATA_BUFFER rp,
 	  return -EPERM;
 	}
       if (check_reparse_point_string (psymbuf))
-	return 1;
+	return PATH_SYMLINK | PATH_REP;
+    }
+  else if (rp->ReparseTag == IO_REPARSE_TAG_CYGUNIX)
+    {
+      PREPARSE_GUID_DATA_BUFFER rgp = (PREPARSE_GUID_DATA_BUFFER) rp;
+      UUID uuid;
+
+      uuid_from_string (CYGWIN_SOCKET_UUID, uuid);
+      if (memcmp (&uuid, &rgp->ReparseGuid, sizeof (UUID)) == 0)
+	return PATH_SOCKET | PATH_REP;
     }
   return 0;
 }
@@ -2377,10 +2387,11 @@ symlink_info::check_reparse_point (HANDLE h, bool remote)
       fileattr &= ~FILE_ATTRIBUTE_REPARSE_POINT;
       return ret;
     }
-  /* ret is > 0, so it's a reparse point, path in symbuf. */
-  sys_wcstombs (srcbuf, SYMLINK_MAX + 7, symbuf.Buffer,
-		symbuf.Length / sizeof (WCHAR));
-  pflags |= PATH_SYMLINK | PATH_REP;
+  /* ret is > 0, so it's a known reparse point, path in symbuf. */
+  pflags |= ret;
+  if (ret & PATH_SYMLINK)
+    sys_wcstombs (srcbuf, SYMLINK_MAX + 7, symbuf.Buffer,
+		  symbuf.Length / sizeof (WCHAR));
   /* A symlink is never a directory. */
   fileattr &= ~FILE_ATTRIBUTE_DIRECTORY;
   return posixify (srcbuf);
diff --git a/winsup/cygwin/path.h b/winsup/cygwin/path.h
index f55804d..dca1e04 100644
--- a/winsup/cygwin/path.h
+++ b/winsup/cygwin/path.h
@@ -192,7 +192,8 @@ class path_conv
   int is_fs_device () const {return isdevice () && is_fs_special ();}
   int is_fs_special () const {return dev.is_fs_special ();}
   int is_lnk_special () const {return is_fs_device () || isfifo () || is_lnk_symlink ();}
-  int issocket () const {return dev.is_device (FH_LOCAL);}
+  int issocket () const {return dev.is_device (FH_LOCAL)
+				|| dev.is_device (FH_UNIX);}
   int iscygexec () const {return path_flags & PATH_CYGWIN_EXEC;}
   int isopen () const {return path_flags & PATH_OPEN;}
   int isctty_capable () const {return path_flags & PATH_CTTY;}