CIFS extensions for UNIX

[Jeremy Allison]

On Fri, Feb 01, 2002 at 03:21:21PM +1100, John Newbigin wrote:
> I have implemented follow_link which makes symlinks work properly on the 
> client but it highligts a problem with SMB_QUERY_FILE_UNIX_BASIC.
> 
> There needs to be a version which always does an lstat 
> (SMB_QUERY_FILE_UNIX_LINK_BASIC?) (does_this_name_look_to_long?).  This 
> needs to be the same as SMB_QUERY_FILE_UNIX_BASIC in all respects except 
> that it does an lstat.
> 
> There are also other stat v lstat problems with the current samba code. 
> SMB_QUERY_FILE_UNIX_LINK currently does no do an lstat.
> 
> In trans2.c call_trans2qfilepathinfo() there is some code which is 
> perhaps meant to address this but I can't see how/what it is attempting 
> to do:

Yes this was broken. I've (hopefully) fixed this in SAMBA_2_2 CVS
today. Please check out and test asap. I won't hold the release
for this.

> At any rate, the server needs to allow the client do request a stat or 
> an lstat when it does a query.

The new code always does a lstat for UNIX extensions.

> Another issue relating to links is that samba appears to not want to 
> create dangling symlinks.  If symlinks are for the clients to resolve 
> then this will prevent the creation of symlinks.  This needs to be 
> addressed.  If it is a security issue then a config option to turn it on 
> and off is probably required.

Yes this is a security issue - allowing dangling symlinks means
clients that don't resolve symlinks could open any file on the
system. A config option has already been discussed but I wasn't
going to make 2.2.3 wait for it.

Jeremy.