msdfs on 3.0.25b - incorrect PATH_NOT_FOUND on deep links

[Jan Martin]

Note: This is the second one of three similar msdfs problems. To avoid
confusion, we call this one the "deep link problem"


Hi all,

Samba 3.0.25b incorrectly answers PATH_NOT_FOUND when being asked about
something in a sub-subdirectory of a DFS link.

This is because dfs_path_lookop() in smbd/msdfs.c issues a call to
unix_convert() (line 390) which does many things, including a sanity
check of the whole path (except the last component). For example, it
returns an error if the local(!) path doesn't exist at all. This result
is correct and valueable - if there is no msdfs redirection in between.
Otherwise, the result is wrong - dfs_path_lookup() gives up too early.
It should return PATH_NOT_COVERED instead of PATH_NOT_FOUND.

To fix that problem, we postponed the return of the error message to the
end of dfs_path_lookup(), after all DFS stuff is done.
This is our patch:
-------------------------------------------------
diff -rU5 samba-3.0.25b-orig/source/smbd/msdfs.c
samba-3.0.25b-deeplink-fix/source/smbd/msdfs.c
--- samba-3.0.25b-orig/source/smbd/msdfs.c      2007-05-11
00:09:34.000000000 +0200
+++ samba-3.0.25b-deeplink-fix/source/smbd/msdfs.c      2007-08-06
15:37:29.000000000 +0200
@@ -386,13 +386,17 @@
         * think this is needed. JRA.
         */
 
        pstrcpy(localpath, pdp->reqpath);
        status = unix_convert(conn, localpath, search_flag, NULL,
&sbuf);
-       if (!NT_STATUS_IS_OK(status)) {
-               return status;
-       }
+       /* the unix conversion is done (and needed) even if the file
+        * doesn't exist locally
+         * 'status' is the best we know now about the path
+         * keep it for function return, but try our DFS stuff before
...
+         * ... if successful, we return the new NT_STATUS_* immediately
+         *     and don't use our old status
+         */
 
        /* Optimization - check if we can redirect the whole path. */
 
        if (is_msdfs_link(conn, localpath, targetpath, NULL)) {
                if (search_flag) {
@@ -458,11 +462,12 @@
                        /* And in the canonicalized dfs path. */
                        q = strrchr_m(canon_dfspath, '/');
                }
        }
 
-       return NT_STATUS_OK;
+       /* We didn't find a DFS link, so consider it a local resource */
+       return status;
 }
 
 /*****************************************************************
  Decides if a dfs pathname should be redirected or not.
  If not, the pathname is converted to a tcon-relative local unix path
-------------------------------------------------

With this patch, our installation does not show the problem any more.
Would you please check and add it (or a better one, of course) to the
Samba sources?

Thank you very much in advance

And again - this is the second one of three similar problems; please
don't get confused. This one is the deep link problem.


Jan Martin