/*
* Copyright (C) 2003-2004 Perolo Silantico <per.sil@gmx.it>
* Copyright (C) 2006 Roberto Alsina <ralsina@kde.org>
* Copyright (C) 2007 Sebastian Werner <blackwing@blackwing.de> 
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later
* version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/

#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include "bstrlib.h"
#include <sys/types.h>
#include <unistd.h>

int
check_rbl (bstring lookup_addr, const char *rbl)
{
  struct addrinfo *ai = NULL;

  bstring lookupname = bformat ("%s.%s", lookup_addr->data, rbl);
  if (getaddrinfo (lookupname->data, NULL, NULL, &ai))
    {
      if (ai)
        freeaddrinfo (ai);
      return 0;
    }
  freeaddrinfo (ai);
  return 1;
}

int
check_rwl (bstring lookup_addr, const char *rbl)
{
  bstring lookupname = bformat ("%s.%s", lookup_addr->data, rbl);
  if (gethostbyname (lookupname->data))
    {
      return 1;
    }
  return 0;
}


bstring
envtostr (char *vname)
{
  bstring retval;
  retval = bfromcstr (getenv (vname));
  if (!retval)
    retval = bfromcstr ("");

  return retval;
}


int
main (int argc, char *argv[])
{
  bstring ip = bfromcstr (getenv ("TCPREMOTEIP"));
  unsigned long address;
  int i;
  int ppid = getppid ();

  if (!ip)                      //Somehow we are running in a bad situation
    {
      printf ("D\n");
      fprintf (stderr, "rblchecks: pid %d - no TCPREMOTEIP\n", ppid);
      exit (0);
    }

  /* User disabled plugin via tcp.smtp - so exit */
  if (getenv ("SKIP_RBL"))
    {
      fprintf (stderr,
               "rblchecks: pid %d - rblchecks skipped.\n",
               ppid);
      exit (0);
    }

  // be IPv6 safe and just exit if PROTO = TCP6
  if (strcmp(getenv ("PROTO"),"TCP6"))
    {
	fprintf (stderr, "rblchecks: pid %d - IPv6 not subject to RBL! Accepted %s\n", ppid, ip->data);
	exit (0);
    }

  // Lets convert address to the RBL lookup format - reverse it!
  address = inet_addr (ip->data);
  bstring addr = bformat ("%lu.%lu.%lu.%lu",
                          (address & 0xff000000) >> 24,
                          (address & 0x00ff0000) >> 16,
                          (address & 0x0000ff00) >> 8,
                          (address & 0x000000ff) >> 0);


  //Check, if host is in white list
  bstring rwl = bfromcstr (getenv ("RWLSERVERS"));
  if (rwl)
    {
      struct bstrList *wlist = bsplit (rwl, ':');
      for (i = 0; i < wlist->qty; i++)
      {
        bstring serv = wlist->entry[i];
        if (serv->slen == 0)
          continue;
        if (check_rwl (addr, serv->data))
          {
            printf ("A\n");
            fprintf (stderr, "rblchecks: pid %d - No checks performed, because %s whitelists %s\n",
                     ppid, serv->data, ip->data);
            exit (0);
          }
      }
    }

  //Check for occurence in blacklist
  bstring rbl = bfromcstr (getenv ("RBLSERVERS"));
  if (!rbl)
    rbl = bfromcstr ("bl.spamcop.net");

  struct bstrList *blist = bsplit (rbl, ':');

  for (i = 0; i < blist->qty; i++)
    {
      bstring serv = blist->entry[i];
      if (serv->slen == 0)
        continue;
      if (check_rbl (addr, serv->data))
        {
          printf
            ("E541 Your IP (%s) is blocked, more information at http://%s\n",
             ip->data, serv->data);
          fprintf (stderr, "rblchecks: pid %d - 541 Blocked by %s (%s)\n",
                   ppid, serv->data, ip->data);
          exit (0);
        }
    }

  // No RBL issues
  fprintf (stderr, "rblchecks: pid %d - Accepted %s\n", ppid, ip->data);
  exit (0);
}