isc-dhcp/server/mdb.c

/* mdb.c

   Server-specific in-memory database support. */

/*
 * Copyright (c) 1996-1999 Internet Software Consortium.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of The Internet Software Consortium nor the names
 *    of its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This software has been written for the Internet Software Consortium
 * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
 * To learn more about the Internet Software Consortium, see
 * ``http://www.isc.org/''.  To learn more about Vixie Enterprises,
 * see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
 * ``http://www.nominum.com''.
 */

#ifndef lint
static char copyright[] =
"$Id: mdb.c,v 1.32 2000/05/16 23:03:46 mellon Exp $ Copyright (c) 1996-2000 The Internet Software Consortium.  All rights reserved.\n";
#endif /* not lint */

#include "dhcpd.h"

struct subnet *subnets;
struct shared_network *shared_networks;
struct hash_table *host_hw_addr_hash;
struct hash_table *host_uid_hash;
struct hash_table *lease_uid_hash;
struct hash_table *lease_ip_addr_hash;
struct hash_table *lease_hw_addr_hash;
struct hash_table *host_name_hash;
static struct lease *dangling_leases;

omapi_object_type_t *dhcp_type_host;

isc_result_t enter_host (hd, dynamicp, commit)
	struct host_decl *hd;
	int dynamicp;
	int commit;
{
	struct host_decl *hp = (struct host_decl *)0;
	struct host_decl *np = (struct host_decl *)0;
	struct executable_statement *esp;

	if (!host_name_hash) {
		host_name_hash =
			new_hash ((hash_reference)host_reference,
				  (hash_dereference)host_dereference, 0);
		if (!host_name_hash)
			log_fatal ("Can't allocate host name hash");
	} else {
		host_hash_lookup (&hp, host_name_hash,
				  (unsigned char *)hd -> name,
				  strlen (hd -> name), MDL);

		/* If it's deleted, we can supersede it. */
		if (hp && (hp -> flags & HOST_DECL_DELETED)) {
			host_hash_delete (host_name_hash,
					  (unsigned char *)hd -> name,
					  strlen (hd -> name), MDL);
			/* If the old entry wasn't dynamic, then we
			   always have to keep the deletion. */
			if (!hp -> flags & HOST_DECL_DYNAMIC)
				hd -> flags |= HOST_DECL_STATIC;
		}

		/* If there isn't already a host decl matching this
		   address, add it to the hash table. */
		if (!hp) {
			host_hash_add (host_name_hash,
				       (unsigned char *)hd -> name,
				       strlen (hd -> name), hd, MDL);
		} else {
			/* XXX actually, we have to delete the old one
			   XXX carefully and replace it.   Not done yet. */
			host_dereference (&hp, MDL);
			return ISC_R_EXISTS;
		}
	}

	if (hd -> n_ipaddr)
		host_dereference (&hd -> n_ipaddr, MDL);

	if (!hd -> type)
		hd -> type = dhcp_type_host;

	if (hd -> interface.hlen) {
		if (!host_hw_addr_hash) {
			host_hw_addr_hash =
				new_hash ((hash_reference)host_reference,
					  (hash_dereference)host_dereference,
					  0);
			if (!host_hw_addr_hash)
				log_fatal ("Can't allocate host/hw hash");
		} else {
			/* If there isn't already a host decl matching this
			   address, add it to the hash table. */
			if (!host_hash_lookup (&hp, host_hw_addr_hash,
					       hd -> interface.hbuf,
					       hd -> interface.hlen, MDL)) {
				host_hash_add (host_hw_addr_hash,
					       hd -> interface.hbuf,
					       hd -> interface.hlen,
					       hd, MDL);
			}
		}
	}

	/* If there was already a host declaration for this hardware
	   address, add this one to the end of the list. */

	if (hp) {
		for (np = hp; np -> n_ipaddr; np = np -> n_ipaddr)
			;
		host_reference (&np -> n_ipaddr, hd, MDL);
		host_dereference (&hp, MDL);
	}

	/* See if there's a statement that sets the client identifier.
	   This is a kludge - the client identifier really shouldn't be
	   set with an executable statement. */
	for (esp = hd -> group -> statements; esp; esp = esp -> next) {
		if (esp -> op == supersede_option_statement &&
		    esp -> data.option &&
		    (esp -> data.option -> option -> universe ==
		     &dhcp_universe) &&
		    (esp -> data.option -> option -> code ==
		     DHO_DHCP_CLIENT_IDENTIFIER)) {
			evaluate_option_cache
				(&hd -> client_identifier, (struct packet *)0,
				 (struct lease *)0, (struct option_state *)0,
				 (struct option_state *)0, &global_scope,
				 esp -> data.option, MDL);
			break;
		}
	}

	/* If we got a client identifier, hash this entry by
	   client identifier. */
	if (hd -> client_identifier.len) {
		/* If there's no uid hash, make one; otherwise, see if
		   there's already an entry in the hash for this host. */
		if (!host_uid_hash) {
			host_uid_hash =
				new_hash ((hash_reference)host_reference,
					  (hash_dereference)host_dereference,
					  0);
			if (!host_uid_hash)
				log_fatal ("Can't allocate host/uid hash");
		} else {
			/* If there's already a host declaration for this
			   client identifier, add this one to the end of the
			   list.  Otherwise, add it to the hash table. */
			if (host_hash_lookup (&hp, host_uid_hash,
					      hd -> client_identifier.data,
					      hd -> client_identifier.len,
					      MDL)) {
				/* Don't link it in twice... */
				if (!np) {
					for (np = hp; np -> n_ipaddr;
					     np = np -> n_ipaddr)
						;
					host_reference (&np -> n_ipaddr,
							hd, MDL);
				}
				host_dereference (&hp, MDL);
			} else {
				host_hash_add (host_uid_hash,
					       hd -> client_identifier.data,
					       hd -> client_identifier.len,
					       hd, MDL);
			}
		}
	}

	if (dynamicp && commit) {
		if (!write_host (hd))
			return ISC_R_IOERROR;
		if (!commit_leases ())
			return ISC_R_IOERROR;
	}

	return ISC_R_SUCCESS;
}

isc_result_t delete_host (hd, commit)
	struct host_decl *hd;
	int commit;
{
	struct host_decl *hp = (struct host_decl *)0;
	struct host_decl *np = (struct host_decl *)0;
	struct host_decl *foo;
	struct executable_statement *esp;
	int hw_head = 0, uid_head = 1;

	/* Don't need to do it twice. */
	if (hd -> flags & HOST_DECL_DELETED)
		return ISC_R_SUCCESS;

	/* But we do need to do it once!   :') */
	hd -> flags |= HOST_DECL_DELETED;

	if (hd -> interface.hlen) {
	    if (host_hw_addr_hash) {
		if (host_hash_lookup (&hp, host_hw_addr_hash,
			hd -> interface.hbuf,
			hd -> interface.hlen, MDL)) {
		    if (hp == hd) {
			host_hash_delete (host_hw_addr_hash,
					  hd -> interface.hbuf,
					  hd -> interface.hlen, MDL);
			hw_head = 1;
		    } else {
			for (foo = hp; foo; foo = foo -> n_ipaddr) {
			    if (foo == hd)
				    break;
			    np = foo;
			}
			if (foo) {
			    host_dereference (&np -> n_ipaddr, MDL);
			    if (hd -> n_ipaddr)
				host_reference (&np -> n_ipaddr,
						hd -> n_ipaddr, MDL);
			}
		    }
		    host_dereference (&hp, MDL);
		}
	    }
	}

	/* If we got a client identifier, hash this entry by
	   client identifier. */
	if (hd -> client_identifier.len) {
	    if (host_uid_hash) {
		if (host_hash_lookup (&hp, host_uid_hash,
				      hd -> client_identifier.data,
				      hd -> client_identifier.len, MDL)) {
		    if (hp == hd) {
			host_hash_delete (host_uid_hash,
					  hd -> client_identifier.data,
					  hd -> client_identifier.len, MDL);
			uid_head = 1;
		    } else {
			for (foo = hp; foo; foo = foo -> n_ipaddr) {
			    if (foo == hd)
				break;
			    np = foo;
			}
			if (foo) {
			    if (np -> n_ipaddr)
				host_dereference (&np -> n_ipaddr, MDL);
			    host_reference (&np -> n_ipaddr,
					    hd -> n_ipaddr, MDL);
			}
		    }
		    host_dereference (&hp, MDL);
		}
	    }
	}

	if (hd -> n_ipaddr) {
		if (uid_head && hd -> n_ipaddr -> client_identifier.len) {
			host_hash_add
				(host_uid_hash,
				 hd -> n_ipaddr -> client_identifier.data,
				 hd -> n_ipaddr -> client_identifier.len,
				 hd -> n_ipaddr, MDL);
		}
		if (hw_head && hd -> n_ipaddr -> interface.hlen) {
			host_hash_add (host_hw_addr_hash,
				       hd -> n_ipaddr -> interface.hbuf,
				       hd -> n_ipaddr -> interface.hlen,
				       hd -> n_ipaddr, MDL);
		}
		host_dereference (&hd -> n_ipaddr, MDL);
	}

	if (host_name_hash) {
		if (host_hash_lookup (&hp, host_name_hash,
				      (unsigned char *)hd -> name,
				      strlen (hd -> name), MDL)) {
			if (hp == hd && !(hp -> flags & HOST_DECL_STATIC)) {
				host_hash_delete (host_name_hash,
						  (unsigned char *)hd -> name,
						  strlen (hd -> name), MDL);
			}
			host_dereference (&hp, MDL);
		}
	}

	if (commit) {
		if (!write_host (hd))
			return ISC_R_IOERROR;
		if (!commit_leases ())
			return ISC_R_IOERROR;
	}
	return ISC_R_SUCCESS;
}

int find_hosts_by_haddr (struct host_decl **hp, int htype,
			 const unsigned char *haddr, unsigned hlen,
			 const char *file, int line)
{
	struct host_decl *foo;
	struct hardware h;

	h.hlen = hlen + 1;
	h.hbuf [0] = htype;
	memcpy (&h.hbuf [1], haddr, hlen);

	return host_hash_lookup (hp, host_hw_addr_hash,
				 h.hbuf, h.hlen, file, line);
}

int find_hosts_by_uid (struct host_decl **hp,
		       const unsigned char *data, unsigned len,
		       const char *file, int line)
{
	return host_hash_lookup (hp, host_uid_hash, data, len, file, line);
}

/* More than one host_decl can be returned by find_hosts_by_haddr or
   find_hosts_by_uid, and each host_decl can have multiple addresses.
   Loop through the list of hosts, and then for each host, through the
   list of addresses, looking for an address that's in the same shared
   network as the one specified.    Store the matching address through
   the addr pointer, update the host pointer to point at the host_decl
   that matched, and return the subnet that matched. */

int find_host_for_network (struct subnet **sp, struct host_decl **host,
			   struct iaddr *addr, struct shared_network *share)
{
	int i;
	struct subnet *subnet;
	struct iaddr ip_address;
	struct host_decl *hp;
	struct data_string fixed_addr;

	memset (&fixed_addr, 0, sizeof fixed_addr);

	for (hp = *host; hp; hp = hp -> n_ipaddr) {
		if (!hp -> fixed_addr)
			continue;
		if (!evaluate_option_cache (&fixed_addr, (struct packet *)0,
					    (struct lease *)0,
					    (struct option_state *)0,
					    (struct option_state *)0,
					    &global_scope,
					    hp -> fixed_addr, MDL))
			continue;
		for (i = 0; i < fixed_addr.len; i += 4) {
			ip_address.len = 4;
			memcpy (ip_address.iabuf,
				fixed_addr.data + i, 4);
			if (find_grouped_subnet (sp, share, ip_address, MDL)) {
				struct host_decl *tmp = (struct host_decl *)0;
				*addr = ip_address;
				/* This is probably not necessary, but
				   just in case *host is the only reference
				   to that host declaration, make a temporary
				   reference so that dereferencing it doesn't
				   dereference hp out from under us. */
				host_reference (&tmp, *host, MDL);
				host_dereference (host, MDL);
				host_reference (host, hp, MDL);
				host_dereference (&tmp, MDL);
				data_string_forget (&fixed_addr, MDL);
				return 1;
			}
		}
		data_string_forget (&fixed_addr, MDL);
	}
	return 0;
}

void new_address_range (low, high, subnet, pool)
	struct iaddr low, high;
	struct subnet *subnet;
	struct pool *pool;
{
	struct lease *address_range, *lp, *plp;
	struct iaddr net;
	unsigned min, max, i;
	char lowbuf [16], highbuf [16], netbuf [16];
	struct shared_network *share = subnet -> shared_network;
	isc_result_t status;

	/* All subnets should have attached shared network structures. */
	if (!share) {
		strcpy (netbuf, piaddr (subnet -> net));
		log_fatal ("No shared network for network %s (%s)",
		       netbuf, piaddr (subnet -> netmask));
	}

	/* Initialize the hash table if it hasn't been done yet. */
	if (!lease_uid_hash) {
		lease_uid_hash =
			new_hash ((hash_reference)lease_reference,
				  (hash_dereference)lease_dereference, 0);
		if (!lease_uid_hash)
			log_fatal ("Can't allocate lease/uid hash");
	}
	if (!lease_ip_addr_hash) {
		lease_ip_addr_hash =
			new_hash ((hash_reference)lease_reference,
				  (hash_dereference)lease_dereference, 0);
		if (!lease_uid_hash)
			log_fatal ("Can't allocate lease/ip hash");
	}
	if (!lease_hw_addr_hash) {
		lease_hw_addr_hash =
			new_hash ((hash_reference)lease_reference,
				  (hash_dereference)lease_dereference, 0);
		if (!lease_uid_hash)
			log_fatal ("Can't allocate lease/hw hash");
	}

	/* Make sure that high and low addresses are in same subnet. */
	net = subnet_number (low, subnet -> netmask);
	if (!addr_eq (net, subnet_number (high, subnet -> netmask))) {
		strcpy (lowbuf, piaddr (low));
		strcpy (highbuf, piaddr (high));
		strcpy (netbuf, piaddr (subnet -> netmask));
		log_fatal ("Address range %s to %s, netmask %s spans %s!",
		       lowbuf, highbuf, netbuf, "multiple subnets");
	}

	/* Make sure that the addresses are on the correct subnet. */
	if (!addr_eq (net, subnet -> net)) {
		strcpy (lowbuf, piaddr (low));
		strcpy (highbuf, piaddr (high));
		strcpy (netbuf, piaddr (subnet -> netmask));
		log_fatal ("Address range %s to %s not on net %s/%s!",
		       lowbuf, highbuf, piaddr (subnet -> net), netbuf);
	}

	/* Get the high and low host addresses... */
	max = host_addr (high, subnet -> netmask);
	min = host_addr (low, subnet -> netmask);

	/* Allow range to be specified high-to-low as well as low-to-high. */
	if (min > max) {
		max = min;
		min = host_addr (high, subnet -> netmask);
	}

	/* Get a lease structure for each address in the range. */
#if defined (COMPACT_LEASES)
	address_range = new_leases (max - min + 1, MDL);
	if (!address_range) {
		strcpy (lowbuf, piaddr (low));
		strcpy (highbuf, piaddr (high));
		log_fatal ("No memory for address range %s-%s.",
			   lowbuf, highbuf);
	}
#endif

	/* Fill out the lease structures with some minimal information. */
	for (i = 0; i < max - min + 1; i++) {
		struct lease *lp = (struct lease *)0;
#if defined (COMPACT_LEASES)
		omapi_object_initialize ((omapi_object_t *)&address_range [i],
					 dhcp_type_lease,
					 0, sizeof (struct lease), MDL);
		lease_reference (&lp, &address_range [i], MDL);
#else
		status = lease_allocate (&lp, MDL);
		if (status != ISC_R_SUCCESS)
			log_fatal ("No memory for lease %s: %s",
				   piaddr (ip_addr (subnet -> net,
						    subnet -> netmask,
						    i + min)),
				   isc_result_totext (status));
		/* Fill in the last lease if it hasn't been already... */
		if (!pool -> last_lease) {
			lease_reference (&pool -> last_lease, lp, MDL);
		}
#endif
		lp -> ip_addr = ip_addr (subnet -> net,
				      subnet -> netmask, i + min);
		lp -> starts = lp -> timestamp = MIN_TIME;
		lp -> ends = MIN_TIME;
		subnet_reference (&lp -> subnet, subnet, MDL);
		pool_reference (&lp -> pool, pool, MDL);
#if defined (FAILOVER_PROTOCOL)
		if (pool -> failover_peer &&
		    pool -> failover_peer -> i_am == secondary)
			lp -> flags = PEER_IS_OWNER;
		else
			lp -> flags = 0;
#endif

		/* Link this entry into the list. */
		if (pool -> leases) {
			lease_reference (&lp -> next, pool -> leases, MDL);
			lease_dereference (&pool -> leases, MDL);
		}
		lease_reference (&pool -> leases, lp, MDL);
		if (lp -> next)
			lease_reference (&lp -> next -> prev,
					 pool -> leases, MDL);
		lease_hash_add (lease_ip_addr_hash, lp -> ip_addr.iabuf,
				lp -> ip_addr.len, lp, MDL);
	}

#if defined (COMPACT_LEASES)
	/* Fill in the last lease if it hasn't been already... */
	if (!pool -> last_lease) {
		lease_reference (&pool -> last_lease, &address_range [0], MDL);
	}
#endif

	/* Find out if any dangling leases are in range... */
	plp = (struct lease *)0;
	for (lp = dangling_leases; lp; lp = lp -> next) {
		struct iaddr lnet;
		int lhost;

		lnet = subnet_number (lp -> ip_addr, subnet -> netmask);
		lhost = host_addr (lp -> ip_addr, subnet -> netmask);

		/* If it's in range, fill in the real lease structure with
		   the dangling lease's values, and remove the lease from
		   the list of dangling leases. */
		if (addr_eq (lnet, subnet -> net) &&
		    lhost >= i && lhost <= max) {
			struct lease *lt = (struct lease *)0;
			if (plp) {
				if (plp -> next)
					lease_dereference (&plp -> next, MDL);
				lease_reference (&plp -> next,
						 lp -> next, MDL);
			} else {
				lease_dereference (&dangling_leases, MDL);
				lease_reference (&dangling_leases,
						 lp -> next, MDL);
			}
			lease_dereference (&lp -> next, MDL);
			if (find_lease_by_ip_addr (&lt, lp -> ip_addr, MDL)) {
				lt -> hostname = lp -> hostname;
				lp -> hostname = (char *)0;
				lt -> client_hostname = lp -> client_hostname;
				lp -> client_hostname = (char *)0;
				supersede_lease (lt, lp, 0, 0);
				lease_dereference (&lt, MDL);
			}
			lease_dereference (&lp, MDL);
		} else
			plp = lp;
	}
}

/* There's really no way to free a lease, because of the aggregate way
   we allocate them. */

isc_result_t dhcp_lease_free (omapi_object_t *lease,
			      const char *file, int line)
{
	return ISC_R_SUCCESS;
}

int find_subnet (struct subnet **sp,
		 struct iaddr addr, const char *file, int line)
{
	struct subnet *rv;

	for (rv = subnets; rv; rv = rv -> next_subnet) {
		if (addr_eq (subnet_number (addr, rv -> netmask), rv -> net)) {
			if (subnet_reference (sp, rv,
					      file, line) != ISC_R_SUCCESS)
				return 0;
			return 1;
		}
	}
	return 0;
}

int find_grouped_subnet (struct subnet **sp,
			 struct shared_network *share, struct iaddr addr,
			 const char *file, int line)
{
	struct subnet *rv;

	for (rv = share -> subnets; rv; rv = rv -> next_sibling) {
		if (addr_eq (subnet_number (addr, rv -> netmask), rv -> net)) {
			if (subnet_reference (sp, rv,
					      file, line) != ISC_R_SUCCESS)
				return 0;
			return 1;
		}
	}
	return 0;
}

int subnet_inner_than (subnet, scan, warnp)
	struct subnet *subnet, *scan;
	int warnp;
{
	if (addr_eq (subnet_number (subnet -> net, scan -> netmask),
		     scan -> net) ||
	    addr_eq (subnet_number (scan -> net, subnet -> netmask),
		     subnet -> net)) {
		char n1buf [16];
		int i, j;
		for (i = 0; i < 32; i++)
			if (subnet -> netmask.iabuf [3 - (i >> 3)]
			    & (1 << (i & 7)))
				break;
		for (j = 0; j < 32; j++)
			if (scan -> netmask.iabuf [3 - (j >> 3)] &
			    (1 << (j & 7)))
				break;
		strcpy (n1buf, piaddr (subnet -> net));
		if (warnp)
			log_error ("%ssubnet %s/%d overlaps subnet %s/%d",
			      "Warning: ", n1buf, 32 - i,
			      piaddr (scan -> net), 32 - j);
		if (i < j)
			return 1;
	}
	return 0;
}

/* Enter a new subnet into the subnet list. */
void enter_subnet (subnet)
	struct subnet *subnet;
{
	struct subnet *scan, *prev = (struct subnet *)0;

	/* Check for duplicates... */
	for (scan = subnets; scan; scan = scan -> next_subnet) {
		/* When we find a conflict, make sure that the
		   subnet with the narrowest subnet mask comes
		   first. */
		if (subnet_inner_than (subnet, scan, 1)) {
			if (prev) {
				subnet_reference (&prev -> next_subnet,
						  subnet, MDL);
			} else
				subnet_reference (&subnets, subnet, MDL);
			subnet_reference (&subnet -> next_subnet, scan, MDL);
			return;
		}
		prev = scan;
	}

	/* XXX use the BSD radix tree code instead of a linked list. */
	subnet -> next_subnet = subnets;
	subnets = subnet;
}
	
/* Enter a new shared network into the shared network list. */

void enter_shared_network (share)
	struct shared_network *share;
{
	if (shared_networks) {
		shared_network_reference (&share -> next,
					  shared_networks, MDL);
		shared_network_dereference (&shared_networks, MDL);
	}
	shared_network_reference (&shared_networks, share, MDL);
}
	
void new_shared_network_interface (cfile, share, name)
	struct parse *cfile;
	struct shared_network *share;
	const char *name;
{
	struct interface_info *ip;
	isc_result_t status;

	if (share -> interface) {
		parse_warn (cfile, 
			    "A subnet or shared network can't be connected %s",
			    "to two interfaces.");
		return;
	}
	
	for (ip = interfaces; ip; ip = ip -> next)
		if (!strcmp (ip -> name, name))
			break;
	if (!ip) {
		status = interface_allocate (&ip, MDL);
		if (status != ISC_R_SUCCESS)
			log_fatal ("new_shared_network_interface %s: %s",
				   name, isc_result_totext (status));
		if (strlen (name) > sizeof ip -> name) {
			memcpy (ip -> name, name, (sizeof ip -> name) - 1);
			ip -> name [(sizeof ip -> name) - 1] = 0;
		} else
			strcpy (ip -> name, name);
		if (interfaces) {
			interface_reference (&ip -> next, interfaces, MDL);
			interface_dereference (&interfaces, MDL);
		}
		interface_reference (&interfaces, ip, MDL);
		ip -> flags = INTERFACE_REQUESTED;
		/* XXX this is a reference loop. */
		shared_network_reference (&ip -> shared_network, share, MDL);
		interface_reference (&share -> interface, ip, MDL);
	}
}

/* Enter a lease into the system.   This is called by the parser each
   time it reads in a new lease.   If the subnet for that lease has
   already been read in (usually the case), just update that lease;
   otherwise, allocate temporary storage for the lease and keep it around
   until we're done reading in the config file. */

void enter_lease (lease)
	struct lease *lease;
{
	struct lease *comp = (struct lease *)0;
	isc_result_t status;

	/* If we don't have a place for this lease yet, save it for
	   later. */
	if (!find_lease_by_ip_addr (&comp, lease -> ip_addr, MDL)) {
		if (comp -> next)
			lease_dereference (&comp -> next, MDL);
		if (dangling_leases)
			lease_reference (&comp -> next, dangling_leases, MDL);
		lease_reference (&dangling_leases, comp, MDL);
		if (comp -> prev)
			lease_dereference (&comp -> prev, MDL);
	} else {
		supersede_lease (comp, lease, 0, 0);
	}
}

/* Replace the data in an existing lease with the data in a new lease;
   adjust hash tables to suit, and insertion sort the lease into the
   list of leases by expiry time so that we can always find the oldest
   lease. */

int supersede_lease (comp, lease, commit, propogate)
	struct lease *comp, *lease;
	int commit;
	int propogate;
{
	int enter_uid = 0;
	int enter_hwaddr = 0;
	struct lease *lp;

	/* Static leases are not currently kept in the database... */
	if (lease -> flags & STATIC_LEASE)
		return 1;

	/* If the existing lease hasn't expired and has a different
	   unique identifier or, if it doesn't have a unique
	   identifier, a different hardware address, then the two
	   leases are in conflict.  If the existing lease has a uid
	   and the new one doesn't, but they both have the same
	   hardware address, and dynamic bootp is allowed on this
	   lease, then we allow that, in case a dynamic BOOTP lease is
	   requested *after* a DHCP lease has been assigned. */

	if (!(lease -> flags & ABANDONED_LEASE) &&
	    comp -> ends > cur_time &&
	    (((comp -> uid && lease -> uid) &&
	      (comp -> uid_len != lease -> uid_len ||
	       memcmp (comp -> uid, lease -> uid, comp -> uid_len))) ||
	     (!comp -> uid &&
	      ((comp -> hardware_addr.hlen !=
		lease -> hardware_addr.hlen) ||
	       memcmp (comp -> hardware_addr.hbuf,
		       lease -> hardware_addr.hbuf,
		       comp -> hardware_addr.hlen))))) {
		log_error ("Lease conflict at %s",
		      piaddr (comp -> ip_addr));
		return 0;
	}

	/* If there's a Unique ID, dissociate it from the hash
	   table and free it if necessary. */
	if (comp -> uid) {
		uid_hash_delete (comp);
		enter_uid = 1;
		if (comp -> uid != &comp -> uid_buf [0]) {
			dfree (comp -> uid, MDL);
			comp -> uid_max = 0;
			comp -> uid_len = 0;
		}
		comp -> uid = (unsigned char *)0;
	} else
		enter_uid = 1;
	
	if (comp -> hardware_addr.hlen &&
	    ((comp -> hardware_addr.hlen !=
	      lease -> hardware_addr.hlen) ||
	     memcmp (comp -> hardware_addr.hbuf,
		     lease -> hardware_addr.hbuf,
		     comp -> hardware_addr.hlen))) {
		hw_hash_delete (comp);
		enter_hwaddr = 1;
	} else if (!comp -> hardware_addr.hlen)
		enter_hwaddr = 1;
	
	/* If the lease has been billed to a class, remove the billing. */
	if (comp -> billing_class &&
	    comp -> billing_class != lease -> billing_class)
 		unbill_class (comp, comp -> billing_class);

	/* Copy the data files, but not the linkages. */
	comp -> starts = lease -> starts;
	if (lease -> uid) {
		if (lease -> uid_len <= sizeof (lease -> uid_buf)) {
			memcpy (comp -> uid_buf,
				lease -> uid, lease -> uid_len);
			comp -> uid = &comp -> uid_buf [0];
			comp -> uid_max = sizeof comp -> uid_buf;
		} else if (lease -> uid != &lease -> uid_buf [0]) {
			comp -> uid = lease -> uid;
			comp -> uid_max = lease -> uid_max;
			lease -> uid = (unsigned char *)0;
			lease -> uid_max = 0;
		} else {
			log_fatal ("corrupt lease uid."); /* XXX */
		}
	} else {
		comp -> uid = (unsigned char *)0;
		comp -> uid_max = 0;
	}
	comp -> uid_len = lease -> uid_len;
	if (comp -> host)
		host_dereference (&comp -> host, MDL);
	host_reference (&comp -> host, lease -> host, MDL);
	comp -> hardware_addr = lease -> hardware_addr;
	comp -> flags = ((lease -> flags & ~PERSISTENT_FLAGS) |
			 (comp -> flags & ~EPHEMERAL_FLAGS));
	if (comp -> scope.bindings)
		free_bindings (&comp -> scope, MDL);
	comp -> scope.bindings = lease -> scope.bindings;
	lease -> scope.bindings = (struct binding *)0;

	/* Record the hostname information in the lease. */
	if (comp -> hostname)
		dfree (comp -> hostname, MDL);
	comp -> hostname = lease -> hostname;
	lease -> hostname = (char *)0;
	if (comp -> client_hostname)
		dfree (comp -> client_hostname, MDL);
	comp -> client_hostname = lease -> client_hostname;
	lease -> client_hostname = (char *)0;

	if (lease -> on_expiry) {
		if (comp -> on_expiry)
			executable_statement_dereference (&comp -> on_expiry,
							  MDL);
		executable_statement_reference (&comp -> on_expiry,
						lease -> on_expiry,
						MDL);
	}
	if (lease -> on_commit) {
		if (comp -> on_commit)
			executable_statement_dereference (&comp -> on_commit,
							  MDL);
		executable_statement_reference (&comp -> on_commit,
						lease -> on_commit,
						MDL);
	}
	if (lease -> on_release) {
		if (comp -> on_release)
			executable_statement_dereference (&comp -> on_release,
							  MDL);
		executable_statement_reference (&comp -> on_release,
						lease -> on_release, MDL);
	}
	
	/* Record the lease in the uid hash if necessary. */
	if (enter_uid && lease -> uid) {
		uid_hash_add (comp);
	}
	
	/* Record it in the hardware address hash if necessary. */
	if (enter_hwaddr && lease -> hardware_addr.hlen) {
		hw_hash_add (comp);
	}
	
	/* Remove the lease from its current place in the 
	   timeout sequence. */
	if (comp -> prev) {
		lease_dereference (&comp -> prev -> next, MDL);
		if (comp -> next) {
			lease_reference (&comp -> prev -> next,
					 comp -> next, MDL);
			lease_dereference (&comp -> next, MDL);
		}
	} else {
		lease_dereference (&comp -> pool -> leases, MDL);
		if (comp -> next) {
			lease_reference (&comp -> pool -> leases,
					 comp -> next, MDL);
		}
	}
	if (comp -> next) {
		lease_dereference (&comp -> next -> prev, MDL);
		if (comp -> prev) {
			lease_reference (&comp -> next -> prev,
					 comp -> prev, MDL);
		}
	}
	if (comp -> pool -> last_lease == comp) {
		lease_dereference (&comp -> pool -> last_lease, MDL);
		if (comp -> prev)
			lease_reference (&comp -> pool -> last_lease,
					 comp -> prev, MDL);
	}
	if (comp -> prev)
		lease_dereference (&comp -> prev, MDL);
	if (comp -> next)
		lease_dereference (&comp -> next, MDL);


	/* If there's an expiry event on this lease, get rid of it
	   (we may wind up putting it back, but we can't count on
	   that here without too much additional complexity). */
	if (comp -> pool -> next_expiry == comp) {
#if defined (FAILOVER_PROTOCOL)
		lp = comp -> prev;
#else
		for (lp = comp -> prev; lp; lp = lp -> prev)
			if (lp -> on_expiry)
				break;
#endif
		if (lp
#if !defined (FAILOVER_PROTOCOL)
		    && lp -> on_expiry
#endif
			) {
			lease_dereference (&comp -> pool -> next_expiry, MDL);
			lease_reference (&comp -> pool -> next_expiry,
					 lp, MDL);
			if (commit)
				add_timeout (lp -> ends,
					     pool_timer, lp -> pool,
					     (tvref_t)pool_reference,
					     (tvunref_t)pool_dereference);
		} else {
			lease_dereference (&comp -> pool -> next_expiry, MDL);
			if (commit)
				cancel_timeout (pool_timer, comp -> pool);
		}
	}
	
	/* Find the last insertion point... */
	if (comp == comp -> pool -> insertion_point ||
	    !comp -> pool -> insertion_point) {
		lp = comp -> pool -> leases;
	} else {
		lp = comp -> pool -> insertion_point;
	}
	
	if (!lp) {
		/* Nothing on the list yet?    Just make comp the
		   head of the list. */
		lease_reference (&comp -> pool -> leases, comp, MDL);
		if (comp -> pool -> last_lease) {
			lease_dereference (&comp -> pool -> last_lease, MDL);
			lease_reference (&comp -> pool -> last_lease,
					 comp, MDL);
		}
	} else if (lp -> ends > lease -> ends) {
		/* Skip down the list until we run out of list
		   or find a place for comp. */
		while (lp -> next && lp -> ends > lease -> ends) {
			lp = lp -> next;
		}
		if (lp -> ends > lease -> ends) {
			/* If we ran out of list, put comp at the end. */
			lease_reference (&lp -> next, comp, MDL);
			lease_reference (&comp -> prev, lp, MDL);
			if (comp -> pool -> last_lease)
				lease_dereference (&comp -> pool -> last_lease,
						   MDL);
			lease_reference (&comp -> pool -> last_lease,
					 comp, MDL);
		} else {
			/* If we didn't, put it between lp and
			   the previous item on the list. */
			if (lp -> prev) {
				lease_reference (&comp -> prev,
						 lp -> prev, MDL);
				lease_dereference (&lp -> prev -> next, MDL);
				lease_reference (&comp -> prev -> next,
						 comp, MDL);
				lease_dereference (&lp -> prev, MDL);
			} else {
				if (comp -> pool -> leases)
					lease_dereference
						(&comp -> pool -> leases, MDL);
				lease_reference (&comp -> pool -> leases,
						 comp, MDL);
			}
			lease_reference (&comp -> next, lp, MDL);
			lease_reference (&lp -> prev, comp, MDL);
		}
	} else {
		/* Skip up the list until we run out of list
		   or find a place for comp. */
		while (lp -> prev && lp -> ends < lease -> ends) {
			lp = lp -> prev;
		}
		if (lp -> ends < lease -> ends) {
			/* If we ran out of list, put comp at the beginning. */
			lease_reference (&lp -> prev, comp, MDL);
			lease_reference (&comp -> next, lp, MDL);
			if (comp -> pool -> leases)
				lease_dereference (&comp -> pool -> leases,
						   MDL);
			lease_reference (&comp -> pool -> leases, comp, MDL);
		} else {
			/* If we didn't, put it between lp and
			   the next item on the list. */
			if (lp -> next) {
				lease_reference (&comp -> next,
						 lp -> next, MDL);
				lease_dereference (&lp -> next -> prev, MDL);
				lease_reference (&lp -> next -> prev,
						 comp, MDL);
				lease_dereference (&lp -> next, MDL);
			} else {
				/* XXX are we really supposed to
				   XXX be doing this? */
				if (comp -> pool -> last_lease)
					lease_dereference
						(&comp -> pool -> last_lease,
						 MDL);
				lease_reference (&comp -> pool -> last_lease,
						 comp, MDL);
			}
			lease_reference (&comp -> prev, lp, MDL);
			lease_reference (&lp -> next, comp, MDL);
		}
	}
	if (comp -> pool -> insertion_point)
		lease_dereference (&comp -> pool -> insertion_point, MDL);
	lease_reference (&comp -> pool -> insertion_point, comp, MDL);
#if defined (FAILOVER_PROTOCOL)
	if (comp -> ends <= cur_time && lease -> ends > cur_time) {
		if (lease -> flags & PEER_IS_OWNER)
			comp -> pool -> peer_leases--;
		else
			comp -> pool -> local_leases--;
	} else if (comp -> ends > cur_time && lease -> ends <= cur_time) {
		if (lease -> flags & PEER_IS_OWNER)
			comp -> pool -> peer_leases++;
		else
			comp -> pool -> local_leases++;
	}		
	comp -> cltt = lease -> cltt;
	comp -> tstp = lease -> tstp;
	comp -> tsfp = lease -> tsfp;
#endif /* FAILOVER_PROTOCOL */
	comp -> ends = lease -> ends;

	/* If there's an expiry event on this lease, process it or
	   queue it. */
#if !defined (FAILOVER_PROTOCOL)
	if (comp -> on_expiry) {
#endif
		if (comp -> ends <= cur_time && commit) {
		    if (comp -> on_expiry) {
			execute_statements ((struct packet *)0, lease,
					    (struct option_state *)0,
					    (struct option_state *)0, /* XXX */
					    &lease -> scope,
					    comp -> on_expiry);
			executable_statement_dereference (&comp -> on_expiry,
							  MDL);
		    }

		    /* No sense releasing a lease after it's expired. */
		    if (comp -> on_release)
			    executable_statement_dereference
				    (&comp -> on_release, MDL);
		} else {
			/* If this is the next lease that will timeout on the
			   pool, zap the old timeout and set the timeout on
			   this pool to the time that the lease ends.
			   
			   We do not actually set the timeout unless commit is
			   true - we don't want to thrash the timer queue when
			   reading the lease database.  Instead, the database
			   code calls the expiry event on each pool after
			   reading in the lease file, and the expiry code sets
			   the timer if there's anything left to expire after
			   it's run any outstanding expiry events on the
			   pool. */
			if (comp -> pool) {
			    if (!comp -> pool -> next_expiry ||
				(comp -> ends <
				 comp -> pool -> next_expiry -> ends)) {
				    if (comp -> pool -> next_expiry)
					lease_dereference
						(&comp -> pool -> next_expiry,
						 MDL);
				    lease_reference
					    (&comp -> pool -> next_expiry,
					     comp, MDL);
				    if (commit)
					add_timeout (comp -> ends,
						     pool_timer,
						     comp -> pool,
						     (tvref_t)pool_reference,
						     (tvunref_t)
						     pool_dereference);
                            } else if (comp -> ends ==
                                       comp -> pool -> next_expiry -> ends) {
                                    /* If there are other leases that expire at
                                       the same time as comp, we need to make
                                       sure that we have the one that appears
                                       last on the list that needs an expiry
                                       event - otherwise we'll miss expiry
                                       events until the server restarts. */
                                    struct lease *foo;
                                    struct lease *install = comp;
                                    for (foo = comp;
					 foo && foo -> ends == comp -> ends;
                                         foo = foo -> next) {
#if !defined (FAILOVER_PROTOCOL)
                                            if (foo -> on_expiry)
#endif
                                                    install = foo;
                                    }
				    lease_dereference
					    (&comp -> pool -> next_expiry,
					     MDL);
                                    lease_reference
					    (&comp -> pool -> next_expiry,
					     install, MDL);
                            }
			}
		}
#if !defined (FAILOVER_PROTOCOL)
	}
#endif

	/* Return zero if we didn't commit the lease to permanent storage;
	   nonzero if we did. */
	return commit && write_lease (comp) && commit_leases ()
#if defined (FAILOVER_PROTOCOL)
		&& (!propogate || dhcp_failover_queue_update (comp))
#endif
		;
}

/* Copy the contents of one lease into another, correctly maintaining
   reference counts. */
int lease_copy (struct lease **lp,
		struct lease *lease, const char *file, int line)
{
	struct lease *lt = (struct lease *)0;
	isc_result_t status;

	status = lease_allocate (&lt, MDL);
	if (status != ISC_R_SUCCESS)
		return 0;

	lt -> ip_addr = lease -> ip_addr;
	lt -> starts = lease -> starts;
	lt -> ends = lease -> ends;
	lt -> timestamp = lease -> timestamp;
	lt -> uid_len = lease -> uid_len;
	lt -> uid_max = lease -> uid_max;
	if (lease -> uid == lease -> uid_buf) {
		lt -> uid = lt -> uid_buf;
		memcpy (lt -> uid_buf, lease -> uid_buf, sizeof lt -> uid_buf);
	} else {
		lt -> uid = dmalloc (lt -> uid_max, MDL);
		if (!lt -> uid) {
			lease_dereference (&lt, MDL);
			return 0;
		}
		memcpy (lt -> uid, lease -> uid, lease -> uid_max);
	}
	if (lease -> hostname) {
		lt -> hostname = dmalloc (strlen (lease -> hostname) + 1, MDL);
		if (!lt -> hostname) {
			lease_dereference (&lt, MDL);
			return 0;
		}
		strcpy (lt -> hostname, lease -> hostname);
	}
	if (lease -> client_hostname) {
		lt -> client_hostname =
			dmalloc (strlen (lease -> client_hostname) + 1, MDL);
		if (!lt -> client_hostname) {
			lease_dereference (&lt, MDL);
			return 0;
		}
		strcpy (lt -> client_hostname, lease -> client_hostname);
	}
	lt -> scope = lease -> scope;
	host_reference (&lt -> host, lease -> host, file, line);
	subnet_reference (&lt -> subnet, lease -> subnet, file, line);
	pool_reference (&lt -> pool, lease -> pool, file, line);
	class_reference (&lt -> billing_class,
			 lease -> billing_class, file, line);
	lt -> hardware_addr = lease -> hardware_addr;
	if (lease -> on_expiry)
		executable_statement_reference (&lt -> on_expiry,
						lease -> on_expiry,
						file, line);
	if (lease -> on_commit)
		executable_statement_reference (&lt -> on_commit,
						lease -> on_commit,
						file, line);
	if (lease -> on_release)
		executable_statement_reference (&lt -> on_release,
						lease -> on_release,
						file, line);
	lt -> flags = lease -> flags;
	lt -> tstp = lease -> tstp;
	lt -> tsfp = lease -> tsfp;
	lt -> cltt = lease -> cltt;
	status = lease_reference (lp, lt, file, line);
	lease_dereference (&lt, MDL);
	return status == ISC_R_SUCCESS;
}

/* Release the specified lease and re-hash it as appropriate. */
void release_lease (lease, packet)
	struct lease *lease;
	struct packet *packet;
{
	struct lease *lt;

	/* If there are statements to execute when the lease is
	   released, execute them. */
	if (lease -> on_release) {
		execute_statements (packet, lease, packet -> options,
				    (struct option_state *)0, /* XXX */
				    &lease -> scope, lease -> on_release);
		if (lease -> on_release)
			executable_statement_dereference (&lease -> on_release,
							  MDL);
	}

	/* We do either the on_release or the on_expiry events, but
	   not both (it's possible that they could be the same,
	   in any case). */
	if (lease -> on_expiry)
		executable_statement_dereference (&lease -> on_expiry, MDL);

	if (lease -> ends > cur_time) {
		if (!lease_copy (&lt, lease, MDL))
			return;

		if (lt -> on_commit)
			executable_statement_dereference (&lt -> on_commit,
							  MDL);

		/* Blow away any bindings. */
		lt -> scope.bindings = (struct binding *)0;

		lt -> ends = cur_time;
		if (lt -> billing_class)
			class_dereference (&lt -> billing_class, MDL);
		supersede_lease (lease, lt, 1, 1);
		lease_dereference (&lt, MDL);
	}
}

/* Abandon the specified lease (set its timeout to infinity and its
   particulars to zero, and re-hash it as appropriate. */

void abandon_lease (lease, message)
	struct lease *lease;
	const char *message;
{
	struct lease *lt = (struct lease *)0;

	lease -> flags |= ABANDONED_LEASE;
	if (!lease_copy (&lt, lease, MDL))
		return;

	if (lt -> on_expiry)
		executable_statement_dereference (&lease -> on_expiry, MDL);
	if (lt -> on_release)
		executable_statement_dereference (&lease -> on_release, MDL);
	if (lt -> on_commit)
		executable_statement_dereference (&lease -> on_commit, MDL);

	/* Blow away any bindings. */
	lt -> scope.bindings = (struct binding *)0;

	lt -> ends = cur_time; /* XXX */
	log_error ("Abandoning IP address %s: %s",
	      piaddr (lease -> ip_addr), message);
	lt -> hardware_addr.hlen = 0;
	if (lt -> uid != lt -> uid_buf)
		dfree (lt -> uid, MDL);
	lt -> uid = (unsigned char *)0;
	lt -> uid_len = 0;
	lt -> uid_max = 0;
	if (lt -> billing_class)
		class_dereference (&lt -> billing_class, MDL);
	supersede_lease (lease, lt, 1, 1);
	lease_dereference (&lt, MDL);
}

/* Abandon the specified lease (set its timeout to infinity and its
   particulars to zero, and re-hash it as appropriate. */

void dissociate_lease (lease)
	struct lease *lease;
{
	struct lease *lt = (struct lease *)0;

	if (!lease_copy (&lt, lease, MDL))
		return;

	if (lt -> on_expiry)
		executable_statement_dereference (&lease -> on_expiry, MDL);
	if (lt -> on_release)
		executable_statement_dereference (&lease -> on_release, MDL);
	if (lt -> on_commit)
		executable_statement_dereference (&lease -> on_commit, MDL);

	/* Blow away any bindings. */
	lt -> scope.bindings = (struct binding *)0;

	lt -> ends = cur_time; /* XXX */
	lt -> hardware_addr.hlen = 0;
	if (lt -> uid != lt -> uid_buf)
		dfree (lt -> uid, MDL);
	lt -> uid = (unsigned char *)0;
	lt -> uid_len = 0;
	lt -> uid_max = 0;
	if (lt -> billing_class)
		class_dereference (&lt -> billing_class, MDL);
	supersede_lease (lease, lt, 1, 1);
	lease_dereference (&lt, MDL);
}

/* Timer called when a lease in a particular pool expires. */
void pool_timer (vpool)
	void *vpool;
{
	struct pool *pool;
	struct lease *lease;

	pool = (struct pool *)vpool;
	for (lease = pool -> next_expiry; lease; lease = lease -> prev) {
		/* Stop processing when we get to the first lease that has not
                   yet expired. */
		if (lease -> ends > cur_time)
			break;

		/* Skip entries that aren't set to expire. */
		if (lease -> on_expiry) {
			/* Okay, the current lease needs to expire, so
                           do it. */
			execute_statements ((struct packet *)0, lease,
					    (struct option_state *)0,
					    (struct option_state *)0, /* XXX */
					    &lease -> scope,
					    lease -> on_expiry);
			if (lease -> on_expiry)
				executable_statement_dereference
					(&lease -> on_expiry, MDL);
		}			

		/* If there's an on_release event, blow it away. */
		if (lease -> on_release)
			executable_statement_dereference (&lease -> on_release,
							  MDL);
		
		/* There are two problems with writing the lease out here.

		   The first is that we've just done a commit, and the write
		   may fail, in which case we will redo the operation.  If the
		   operation is not idempotent, we're in trouble here.  I have
		   no proposed solution for this problem - make the event
		   idempotent, or make sure that it at least isn't harmful to
		   do it twice.

		   The second is that if we just read in the lease file and ran
		   all the expiry events, we're going to rewrite all expiring
		   leases twice.  There's no real answer for this - if we
		   postpone writing until we've expired all leases, we're
		   increasing the window to lose as described above.  I guess a
		   dirty bit on the lease would work.  Hm. */
		if (!write_lease (lease)) {
			log_error ("Error updating lease %s after expiry",
				   piaddr (lease -> ip_addr));
		}
		if (!commit_leases ()) {
			log_error ("Error committing after writing lease %s",
				   piaddr (lease -> ip_addr));
		}
#if defined (FAILOVER_PROTOCOL)
		if (lease -> flags & PEER_IS_OWNER)
			pool -> peer_leases++;
		else
			pool -> local_leases++;
#endif
	}
	if (pool -> next_expiry)
		lease_dereference (&pool -> next_expiry, MDL);
	if (lease) {
		lease_reference (&pool -> next_expiry, lease, MDL);
		add_timeout (lease -> ends, pool_timer, pool,
			     (tvref_t)pool_reference,
			     (tvunref_t)pool_dereference);
	}
}

/* Locate the lease associated with a given IP address... */

int find_lease_by_ip_addr (struct lease **lp, struct iaddr addr,
			   const char *file, int line)
{
	return lease_hash_lookup (lp, lease_ip_addr_hash,
				  addr.iabuf, addr.len, file, line);
}

int find_lease_by_uid (struct lease **lp, const unsigned char *uid,
		       unsigned len, const char *file, int line)
{
	if (len == 0)
		return 0;
	return lease_hash_lookup (lp, lease_uid_hash, uid, len, file, line);
}

int find_lease_by_hw_addr (struct lease **lp,
			   const unsigned char *hwaddr, unsigned hwlen,
			   const char *file, int line)
{
	if (hwlen == 0)
		return 0;
	return lease_hash_lookup (lp, lease_hw_addr_hash,
				  hwaddr, hwlen, file, line);
}

/* Add the specified lease to the uid hash. */

void uid_hash_add (lease)
	struct lease *lease;
{
	struct lease *head = (struct lease *)0;
	struct lease *scan;


	/* If it's not in the hash, just add it. */
	if (!find_lease_by_uid (&head, lease -> uid, lease -> uid_len, MDL))
		lease_hash_add (lease_uid_hash, lease -> uid,
				lease -> uid_len, lease, MDL);
	else {
		/* Otherwise, attach it to the end of the list. */
		for (scan = head; scan -> n_uid; scan = scan -> n_uid)
			;
		lease_reference (&scan -> n_uid, lease, MDL);
		lease_dereference (&head, MDL);
	}
}

/* Delete the specified lease from the uid hash. */

void uid_hash_delete (lease)
	struct lease *lease;
{
	struct lease *head = (struct lease *)0;
	struct lease *scan;

	/* If it's not in the hash, we have no work to do. */
	if (!find_lease_by_uid (&head, lease -> uid, lease -> uid_len, MDL)) {
		if (lease -> n_uid)
			lease_dereference (&lease -> n_uid, MDL);
		return;
	}

	/* If the lease we're freeing is at the head of the list,
	   remove the hash table entry and add a new one with the
	   next lease on the list (if there is one). */
	if (head == lease) {
		lease_hash_delete (lease_uid_hash,
				   lease -> uid, lease -> uid_len, MDL);
		if (lease -> n_uid) {
			lease_hash_add (lease_uid_hash,
					lease -> n_uid -> uid,
					lease -> n_uid -> uid_len,
					lease -> n_uid, MDL);
			lease_dereference (&lease -> n_uid, MDL);
		}
	} else {
		/* Otherwise, look for the lease in the list of leases
		   attached to the hash table entry, and remove it if
		   we find it. */
		for (scan = head; scan -> n_uid; scan = scan -> n_uid) {
			if (scan -> n_uid == lease) {
				lease_dereference (&scan -> n_uid, MDL);
				if (lease -> n_uid) {
					lease_reference (&scan -> n_uid,
							 lease -> n_uid, MDL);
					lease_dereference (&lease -> n_uid,
							   MDL);
				}
				break;
			}
		}
		lease_dereference (&head, MDL);
	}
}

/* Add the specified lease to the hardware address hash. */

void hw_hash_add (lease)
	struct lease *lease;
{
	struct lease *head = (struct lease *)0;
	struct lease *scan;

	/* If it's not in the hash, just add it. */
	if (!find_lease_by_hw_addr (&head, lease -> hardware_addr.hbuf,
				    lease -> hardware_addr.hlen, MDL))
		lease_hash_add (lease_hw_addr_hash,
				lease -> hardware_addr.hbuf,
				lease -> hardware_addr.hlen,
				lease, MDL);
	else {
		/* Otherwise, attach it to the end of the list. */
		for (scan = head; scan -> n_hw; scan = scan -> n_hw)
			;
		lease_reference (&scan -> n_hw, lease, MDL);
		lease_dereference (&head, MDL);
	}
}

/* Delete the specified lease from the hardware address hash. */

void hw_hash_delete (lease)
	struct lease *lease;
{
	struct lease *head = (struct lease *)0;
	struct lease *scan;

	/* If it's not in the hash, we have no work to do. */
	if (!find_lease_by_hw_addr (&head, lease -> hardware_addr.hbuf,
				    lease -> hardware_addr.hlen, MDL)) {
		if (lease -> n_hw)
			lease_dereference (&lease -> n_hw, MDL);
		return;
	}

	/* If the lease we're freeing is at the head of the list,
	   remove the hash table entry and add a new one with the
	   next lease on the list (if there is one). */
	if (head == lease) {
		lease_hash_delete (lease_hw_addr_hash,
				   lease -> hardware_addr.hbuf,
				   lease -> hardware_addr.hlen, MDL);
		if (lease -> n_hw) {
			lease_hash_add (lease_hw_addr_hash,
					lease -> n_hw -> hardware_addr.hbuf,
					lease -> n_hw -> hardware_addr.hlen,
					lease -> n_hw, MDL);
			lease_dereference (&lease -> n_hw, MDL);
		}
	} else {
		/* Otherwise, look for the lease in the list of leases
		   attached to the hash table entry, and remove it if
		   we find it. */
		for (scan = head; scan -> n_hw; scan = scan -> n_hw) {
			if (scan -> n_hw == lease) {
				lease_dereference (&scan -> n_hw, MDL);
				if (lease -> n_hw) {
					lease_reference (&scan -> n_hw,
							 lease -> n_hw, MDL);
					lease_dereference (&lease -> n_hw,
							   MDL);
				}
				break;
			}
		}
	}
	lease_dereference (&head, MDL);
}

/* Write all interesting leases to permanent storage. */

void write_leases ()
{
	struct lease *l;
	struct shared_network *s;
	struct pool *p;
	struct host_decl *hp;
	struct group_object *gp;
	struct hash_bucket *hb;
	int i;
	int num_written;

	/* Write all the dynamically-created group declarations. */
	if (group_name_hash) {
	    num_written = 0;
	    for (i = 0; i < group_name_hash -> hash_count; i++) {
		for (hb = group_name_hash -> buckets [i];
		     hb; hb = hb -> next) {
			gp = (struct group_object *)hb -> value;
			if ((gp -> flags & GROUP_OBJECT_DYNAMIC) ||
			    ((gp -> flags & GROUP_OBJECT_STATIC) &&
			     (gp -> flags & GROUP_OBJECT_DELETED))) {
				write_group (gp);
				++num_written;
			}
		}
	    }
	    log_info ("Wrote %d group decls to leases file.", num_written);
	}

	/* Write all the deleted host declarations. */
	if (host_name_hash) {
	    num_written = 0;
	    for (i = 0; i < host_name_hash -> hash_count; i++) {
		for (hb = host_name_hash -> buckets [i];
		     hb; hb = hb -> next) {
			hp = (struct host_decl *)hb -> value;
			if (((hp -> flags & HOST_DECL_STATIC) &&
			     (hp -> flags & HOST_DECL_DELETED))) {
				write_host (hp);
				++num_written;
			}
		}
	    }
	    log_info ("Wrote %d deleted host decls to leases file.",
		      num_written);
	}

	/* Write all the new, dynamic host declarations. */
	if (host_name_hash) {
	    num_written = 0;
	    for (i = 0; i < host_name_hash -> hash_count; i++) {
		for (hb = host_name_hash -> buckets [i];
		     hb; hb = hb -> next) {
			hp = (struct host_decl *)hb -> value;
			if ((hp -> flags & HOST_DECL_DYNAMIC)) {
				write_host (hp);
				++num_written;
			}
		}
	    }
	    log_info ("Wrote %d new dynamic host decls to leases file.",
		      num_written);
	}

	/* XXX Write all the billing classes. */

#if defined (FAILOVER_PROTOCOL)
	/* Write all the failover states. */
	dhcp_failover_write_all_states ();
#endif

	/* Write all the leases. */
	num_written = 0;
	for (s = shared_networks; s; s = s -> next) {
		for (p = s -> pools; p; p = p -> next) {
			for (l = p -> leases; l; l = l -> next) {
				if (l -> hardware_addr.hlen ||
				    l -> uid_len ||
				    (l -> flags & ABANDONED_LEASE)) {
					if (!write_lease (l))
						log_fatal ("Can't rewrite %s",
							   "lease database");
					num_written++;
				}
			}
		}
	}
	log_info ("Wrote %d leases to leases file.", num_written);
	if (!commit_leases ())
		log_fatal ("Can't commit leases to new database: %m");
}

/* Run expiry events on every pool.   This is called on startup so that
   any expiry events that occurred after the server stopped and before it
   was restarted can be run.   At the same time, if failover support is
   compiled in, we compute the balance of leases for the pool. */

void expire_all_pools ()
{
	struct shared_network *s;
	struct pool *p;
	struct hash_bucket *hb;
	int i;
	struct lease *l;

	/* Loop through each pool in each shared network and call the
	   expiry routine on the pool. */
	for (s = shared_networks; s; s = s -> next) {
	    for (p = s -> pools; p; p = p -> next) {
		pool_timer (p);

#if defined (FAILOVER_PROTOCOL)
		p -> lease_count = 0;
		p -> local_leases = 0;
		p -> peer_leases = 0;
		
		for (l = p -> leases; l; l = l -> next) {
			p -> lease_count++;
			if (l -> ends <= cur_time) {
				if (l -> flags & PEER_IS_OWNER)
					p -> peer_leases++;
				else
					p -> local_leases++;
			}
			if (p -> failover_peer &&
			    l -> tstp > l -> tsfp &&
			    !(l -> flags & ON_UPDATE_QUEUE))
				dhcp_failover_queue_update (l);
		}
#endif
	    }
	}
}

void dump_subnets ()
{
	struct lease *l;
	struct shared_network *s;
	struct subnet *n;
	struct pool *p;

	log_info ("Subnets:");
	for (n = subnets; n; n = n -> next_subnet) {
		log_debug ("  Subnet %s", piaddr (n -> net));
		log_debug ("     netmask %s",
		       piaddr (n -> netmask));
	}
	log_info ("Shared networks:");
	for (s = shared_networks; s; s = s -> next) {
		log_info ("  %s", s -> name);
		for (p = s -> pools; p; p = p -> next) {
			for (l = p -> leases; l; l = l -> next) {
				print_lease (l);
			}
			log_debug ("Last Lease:");
			print_lease (p -> last_lease);
		}
	}
}

HASH_FUNCTIONS (lease, const unsigned char *, struct lease)
HASH_FUNCTIONS (host, const unsigned char *, struct host_decl)
HASH_FUNCTIONS (class, const char *, struct class)