/*
 * check.c
 * - consistency checks
 */
/*
 *  This file is
 *    Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
 *
 *  It is part of adns, which is
 *    Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
 *    Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
 *  
 *  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, 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. 
 *
 * $Id: check.c,v 1.2 2003/06/14 13:55:50 tr-ircd Exp $
 */

#include "struct.h"
#include "fileio.h"
#include "internal.h"

void adns_checkconsistency(adns_state ads, adns_query qu)
{
    adns__consistency(ads, qu, cc_user);
}

#define DLIST_CHECK(list, nodevar, part, body)					\
  if ((list).head) {								\
    assert(! (list).head->part back);						\
    for ((nodevar)= (list).head; (nodevar); (nodevar)= (nodevar)->part next) {	\
      assert((nodevar)->part next						\
	     ? (nodevar) == (nodevar)->part next->part back			\
	     : (nodevar) == (list).tail);					\
      body									\
    }										\
  }

#define DLIST_CHECK_PARTLESS(list, nodevar, body)                               \
  if ((list).head) {                                                            \
    assert(! (list).head->back);                                                \
    for ((nodevar)= (list).head; (nodevar); (nodevar)= (nodevar)->next) {       \
      assert((nodevar)->next                                                    \
             ? (nodevar) == (nodevar)->next->back                               \
             : (nodevar) == (list).tail);                                       \
      body                                                                      \
    }                                                                           \
  }

#define DLIST_ASSERTON(node, nodevar, list, part)				\
  do {										\
    for ((nodevar)= (list).head;						\
	 (nodevar) != (node);							\
	 (nodevar)= (nodevar)->part next) {					\
      assert((nodevar));							\
    }										\
  } while(0)

#define DLIST_ASSERTON_PARTLESS(node, nodevar, list)                            \
  do {                                                                          \
    for ((nodevar)= (list).head;                                                \
         (nodevar) != (node);                                                   \
         (nodevar)= (nodevar)->next) {                                          \
      assert((nodevar));                                                        \
    }                                                                           \
  } while(0)

static void checkc_query_alloc(adns_state ads, adns_query qu)
{
allocnode *an;

    DLIST_CHECK_PARTLESS(qu->allocations, an, {
			 });
}

static void checkc_query(adns_state ads, adns_query qu)
{
adns_query child;

    assert(qu->udpnextserver < ads->nservers);
    assert(!(qu->udpsent & (~0UL << ads->nservers)));
    assert(qu->search_pos <= ads->nsearchlist);
    if (qu->parent)
	DLIST_ASSERTON(qu, child, qu->parent->children, siblings.);
}

static void checkc_notcpbuf(adns_state ads)
{
    assert(!ads->tcpsend.used);
    assert(!ads->tcprecv.used);
    assert(!ads->tcprecv_skip);
}

static void checkc_global(adns_state ads)
{
int i;

    assert(ads->udpsocket >= 0);

    for (i = 0; i < ads->nsortlist; i++)
	assert(!(ads->sortlist[i].base.s_addr & ~ads->sortlist[i].mask.s_addr));

    assert(ads->tcpserver >= 0 && ads->tcpserver < ads->nservers);

    switch (ads->tcpstate) {
	case server_connecting:
	    assert(ads->tcpsocket >= 0);
	    checkc_notcpbuf(ads);
	    break;
	case server_disconnected:
	case server_broken:
	    assert(ads->tcpsocket == -1);
	    checkc_notcpbuf(ads);
	    break;
	case server_ok:
	    assert(ads->tcpsocket >= 0);
	    assert(ads->tcprecv_skip <= ads->tcprecv.used);
	    break;
	default:
	    assert(!"ads->tcpstate value");
    }

    assert(ads->searchlist || !ads->nsearchlist);
}

static void checkc_queue_udpw(adns_state ads)
{
adns_query qu;

    DLIST_CHECK_PARTLESS(ads->udpw, qu, {
			 assert(qu->state == query_tosend);
			 assert(qu->retries <= UDPMAXRETRIES);
			 assert(qu->udpsent);
			 assert(!qu->children.head && !qu->children.tail);
			 checkc_query(ads, qu); checkc_query_alloc(ads, qu);});
}

static void checkc_queue_tcpw(adns_state ads)
{
adns_query qu;

    DLIST_CHECK_PARTLESS(ads->tcpw, qu, {
			 assert(qu->state == query_tcpw);
			 assert(!qu->children.head && !qu->children.tail);
			 assert(qu->retries <= ads->nservers + 1);
			 checkc_query(ads, qu); checkc_query_alloc(ads, qu);});
}

static void checkc_queue_childw(adns_state ads)
{
adns_query parent, child;

    DLIST_CHECK_PARTLESS(ads->childw, parent, {
			 assert(parent->state == query_childw);
			 assert(parent->children.head);
			 DLIST_CHECK(parent->children, child, siblings., {
				     assert(child->parent == parent);
				     assert(child->state != query_done);});
			 checkc_query(ads, parent); checkc_query_alloc(ads, parent);});
}

static void checkc_queue_output(adns_state ads)
{
adns_query qu;

    DLIST_CHECK_PARTLESS(ads->output, qu, {
			 assert(qu->state == query_done);
			 assert(!qu->children.head && !qu->children.tail);
			 assert(!qu->parent);
			 assert(!qu->allocations.head && !qu->allocations.tail);
			 checkc_query(ads, qu);});
}

void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc)
{
adns_query search;

    switch (cc) {
	case cc_user:
	    break;
	case cc_entex:
	    if (!(ads->iflags & adns_if_checkc_entex))
		return;
	    break;
	case cc_freq:
	    if ((ads->iflags & adns_if_checkc_freq) != adns_if_checkc_freq)
		return;
	    break;
	default:
	    abort();
    }

    checkc_global(ads);
    checkc_queue_udpw(ads);
    checkc_queue_tcpw(ads);
    checkc_queue_childw(ads);
    checkc_queue_output(ads);

    if (qu) {
	switch (qu->state) {
	    case query_tosend:
		DLIST_ASSERTON_PARTLESS(qu, search, ads->udpw);
		break;
	    case query_tcpw:
		DLIST_ASSERTON_PARTLESS(qu, search, ads->tcpw);
		break;
	    case query_childw:
		DLIST_ASSERTON_PARTLESS(qu, search, ads->childw);
		break;
	    case query_done:
		DLIST_ASSERTON_PARTLESS(qu, search, ads->output);
		break;
	    default:
		assert(!"specific query state");
	}
    }
}