generalising source of smb.conf

[Christopher R. Hertel]

Nigel,

We've had lots of discussions regarding this sort of thing.  I'm willing 
to put in my 2cents but I've found that it is difficult to make changes 
because the current mechanism is so deeply rooted.

Still, with several of us working on it...

Chris -)-----
Samba Team

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> Hi
> 
> I hope to implement access to Samba configuration parameters from LDAP 
> in the next few weeks.  I think generalising the way the configuration 
> source is specified could be the most simple method of integration. I 
> have written some notes suggesting how it may be done.  Is anybody 
> already working on this? Would this be of general use? If it could be 
> merged into Samba, are there any suggestions for simple modifications 
> that may make it more compatible. 
> 
> Nigel Williams
> 
> LDAP storage format
> -------------------
> 
> Hierarchical storage 
> 
> Split on type (application server, home server ...) then domain, then 
> hostname. (specific to this site)
> 
> To generate a config file start from root and follow path as far as 
> possible overlaying options. 
> 
> Updating the LDAP storage
> -------------------------
> 
> Initially. Store data in text format using directories to provide 
> structure. This will 
> provide text backup. 
> 
> Write a make script to update storage.
> 
> Eventually. Allow modification in place. 
> 
> locking ... 
> 
> Method
> ------
> 
> Create URL style syntax for configuration files.  Associate functions 
> with URL types 
> 
> e.g. smb.conf, file://localhost/etc/smb.conf, 
> ldap://[host=%m,hostdomain=nt.dev.uk,hosttype=core_server],U=Samba,OU=ap
> ps,l=eu,o=nomura.com
> 
> Dynamically load (dlopen(), dlsym()) modules to handle types (file, 
> ldap ...) specified in the URL (default to local file).
> 
> The module parses the name to provide a 
> 
> 1. path         (opaque argument to read/stat method. May locate host 
> in host type space.)
> 2. stat method  (get modification date)
> 3. read method  (extract data and write to local file.  Return path to 
> local file)
>  
> Functions to modify
> -------------------
> 
> param/loadparam.c
> -----------------
> 
> add_to_file_list()
> 
> Check file name format.  Set stat method for the file. Each entry in 
> the linked list could have a pointer to the stat method for its 
> associated file. The stat method would take the "path" as an argument. 
> 
> handle_include()
> 
> Get read file method for file name.  Call the read file method 
> associated with the file name.  This function 
> should take the "path" as an argument and return the name of a local 
> file that it has created.  This file will contain the configuration 
> data. The filename can then be passed on to lp_load().
> 
> As there may be many processes all accessing configuration data care 
> must be taken to ensure that configuration files are not created for 
> each process.  The filename of the file should contain the modification 
> date of the LDAP data.  The read method can check the modified date 
> using the stat method, fabricate the filename and then check for its 
> existence.  Old files should be deleted whenever a new one has been 
> created.
> 
> lp_file_list_changed
> 
> Use stat method for file to check modification date.
> 
> lp_load ?
> 
> A change to this function may be required. It is called directly (i.e. 
> not from reload services) in several pieces of Samba code and passed 
> the configuration file name.  It may be best to get a pointer to and 
> run the read-file method within this code so that all files are caught 
> including those given on the command line.      
> 
> smbd/server.c
> nmbd/server.c
> -------------
> 
> reload_services
> 
> This function calls lp_load() passing the return value of 
> lp_configfile().
> 
> It may be a good point to check for source type and read method.
> 
> --openmail-part-019afd0c-00000001--
> 


-- 
Christopher R. Hertel -)-----                   University of Minnesota
crh at nts.umn.edu              Networking and Telecommunications Services