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/* $OpenBSD: smtpfilter.c,v 1.5 2012/09/03 21:28:21 chl Exp $ */
/*
* Copyright (c) 2011 Gilles Chehade <gilles@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <stdlib.h>
#include "filter_api.h"
enum filter_status helo_cb(uint64_t, struct filter_helo *, void *);
enum filter_status ehlo_cb(uint64_t, struct filter_helo *, void *);
enum filter_status mail_cb(uint64_t, struct filter_mail *, void *);
enum filter_status rcpt_cb(uint64_t, struct filter_rcpt *, void *);
enum filter_status dataline_cb(uint64_t, struct filter_dataline *, void *);
/*
* *ALL* of the callbacks follow the same principle:
*
* First parameter is a unique identifier that has been assigned to the
* client session when it connected. The same client session entering a
* second callback will enter it with the same id.
*
* Second parameter is a callback-specific structure filled with all of
* the information necessary to handle filtering at the callback stage.
* Some of the callbacks allow envelope or data rewriting.
*
* Third parameter is a filter-specific argument. It can be NULL, or it
* can be anything the developer wants, typically a structure allocated
* in main() to keep various states.
* A different paramter can be registered for each callback.
*
* RETURN VALUES:
*
* callbacks return either one of:
*
* STATUS_IGNORE : do not take a decision to accept or reject
* STATUS_REJECT : reject the envelope / message depending on hook
* STATUS_ACCEPT : accept the envelope / message depending on hook
* STATUS_WAITING : the callback is waiting for an asynch. event
*
* -- gilles@
*
*/
enum filter_status
helo_cb(uint64_t id, struct filter_helo *helo, void *mystuff)
{
return STATUS_IGNORE;
}
enum filter_status
mail_cb(uint64_t id, struct filter_mail *mail, void *mystuff)
{
return STATUS_IGNORE;
}
enum filter_status
rcpt_cb(uint64_t id, struct filter_rcpt *rcpt, void *mystuff)
{
if (rcpt->user[0] == 'a')
return STATUS_REJECT;
return STATUS_IGNORE;
}
/*
* Not all callbacks need to be implemented !
*/
int
main(int argc, char *argv[])
{
void *mystuff;
/*
* this MUST be the first think your filter does.
* do not do anything before that call: NOTHING.
*/
filter_init();
/*
* NOW you can allocate your structures, read a configuration
* file or do anything required to prepare your filter before
* it starts handling requests.
*/
mystuff = malloc(42);
/*
* we only need to register for callbacks we're interested in
*/
filter_register_helo_callback(helo_cb, mystuff);
filter_register_mail_callback(mail_cb, mystuff);
filter_register_rcpt_callback(rcpt_cb, mystuff);
/*
* filter_register_ehlo_callback(helo_cb, mystuff);
* filter_register_rcpt_callback(rcpt_cb, mystuff);
* filter_register_dataline_callback(dataline_cb, mystuff);
* filter_register_quit_callback(quit_cb, mystuff);
*/
/*
* finally, enter the filter_loop().
* it will not return unless a critical failure happens.
* do not call exit() from a callback.
*/
filter_loop();
return 0;
}
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