Milter-greylist

On Fri, Oct 21, 2005 at 02:18:36PM +0300, Fredrik Nyberg DC wrote:
> OK, I see your point. Of course, the problem could also be solved using 
> a persistent datastore. SQLLite has been mentioned, I also saw it on the 
> todo list on the milter-greylist homepage. Where do you think efforts 
> should be concentrated?

IMO the first step is to change autowhite.c and pending.c so that
there is a clean separation between the storage backend and milter-greylist.

The two files shouldbe merged into a unique file for the local storage
backend. it could be named storage_local.c for instance.

Then we would define a structure containing function pointers for the
various methods. storage_local.c would define an instance of the structure 
for the local storage backend, and we could add a file for a SQLite backend.

An idea for the structure, after a quick look at the code
struct storage {
	/* Initialization */
	void (*s_init)(void); 

	/* Autowhitelist management */
	struct autowhite *(*s_awget)(struct sockaddr *, 
				     socklen_t, char *, char *, time_t *);
	void (*s_awput)(struct autowhite *);
	void (*s_awadd)(struct sockaddr *, socklen_t, char *, 
			char *, time_t *, char *);
	int (*s_awcheck)(struct sockaddr *, socklen_t, char *, char *, char *);
	int (*s_awtextdump)(FILE *);

	/* greylist management */
	struct pending *(*s_pget)(struct sockaddr *, socklen_t, 
				  char *, char *, time_t);
	int (*s_pcheck)(struct sockaddr *, socklen_t, char *, 
		        char *, time_t *, time_t *, char *);
	void (*s_pdel)(struct sockaddr *, socklen_t, char *, char *, time_t);  
	void (*s_pput)(struct pending *);
	int (*s_ptextdump)(FILE *);
};

storage_local.c would define
struct storage storage_local = {
	local_init, 	/* Would call former autowhite_init and pending_init */
	local_awget,	/* former autowhite_get */
	local_awput,	/* former autowhite_put */
	...
};

Next step is to have a field in struct conf for the storage:
	struct storage *c_storage;

And set defconf so that this field defaults to &storage_local.

Then you have to change any call to autowhite_* or pending_* in the
code to a reference through the the conf.c_storage structure:
	pending = pending_get(sa, salen, from, rcpt, (time_t)0) 
turns into
	pending = (*conf.c_storage->s_pget)(sa, salen, from, rcpt, (time_t)0);


Then you can start writing the SQLite backend, in storage_sqlite.c. At some 
point you'll have to change the config file parser to add a storage keyword.

Of course you might discover that the API I just defined isn't suited for 
other use, or that it bounds to a lot of code duplication. We might have 
to refactor the code to avoid that.

Do you want to give it a try?

-- 
Emmanuel Dreyfus
manu@...