mdb.c

DHCP服务器源码

	if (comp -> scope)
		binding_scope_dereference (&comp -> scope, MDL);
	if (lease -> scope) {
		binding_scope_reference (&comp -> scope, lease -> scope, MDL);
		binding_scope_dereference (&lease -> scope, MDL);
	}

	if (comp -> agent_options)
		option_chain_head_dereference (&comp -> agent_options, MDL);
	if (lease -> agent_options) {
		/* Only retain the agent options if the lease is still
		   affirmatively associated with a client. */
		if (lease -> next_binding_state == FTS_ACTIVE ||
		    lease -> next_binding_state == FTS_EXPIRED)
			option_chain_head_reference (&comp -> agent_options,
						     lease -> agent_options,
						     MDL);
		option_chain_head_dereference (&lease -> agent_options, MDL);
	}

	/* Record the hostname information in the lease. */
	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 && comp -> 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);
	}
	
#if defined (FAILOVER_PROTOCOL)
	comp -> cltt = lease -> cltt;
	comp -> tstp = lease -> tstp;
	comp -> tsfp = lease -> tsfp;
#endif /* FAILOVER_PROTOCOL */
	comp -> ends = lease -> ends;
	comp -> next_binding_state = lease -> next_binding_state;

      just_move_it:
	if (!comp -> pool) {
		log_error ("Supersede_lease: lease %s with no pool.",
			   piaddr (comp -> ip_addr));
		return 0;
	}

	/* Figure out which queue it's on. */
	switch (comp -> binding_state) {
	      case FTS_FREE:
		lq = &comp -> pool -> free;
		comp -> pool -> free_leases--;
		break;

	      case FTS_ACTIVE:
		lq = &comp -> pool -> active;
		break;

	      case FTS_EXPIRED:
	      case FTS_RELEASED:
	      case FTS_RESET:
		lq = &comp -> pool -> expired;
		break;

	      case FTS_ABANDONED:
		lq = &comp -> pool -> abandoned;
		break;

	      case FTS_BACKUP:
		lq = &comp -> pool -> backup;
		comp -> pool -> backup_leases--;
		break;

	      default:
		log_error ("Lease with bogus binding state: %d",
			   comp -> binding_state);
#if defined (BINDING_STATE_DEBUG)
		abort ();
#endif
		return 0;
	}

	/* Remove the lease from its current place in its current
	   timer sequence. */
	prev = (struct lease *)0;
	for (lp = *lq; lp; lp = lp -> next) {
		if (lp == comp)
			break;
		prev = lp;
	}

	if (!lp) {
		log_error ("Lease with binding state %s not on its queue.",
			   (comp -> binding_state < 1 ||
			    comp -> binding_state > FTS_LAST)
			   ? "unknown"
			   : binding_state_names [comp -> binding_state - 1]);
		return 0;
	}
	
	if (prev) {
		lease_dereference (&prev -> next, MDL);
		if (comp -> next) {
			lease_reference (&prev -> next, comp -> next, MDL);
			lease_dereference (&comp -> next, MDL);
		}
	} else {
		lease_dereference (lq, MDL);
		if (comp -> next) {
			lease_reference (lq, comp -> next, MDL);
			lease_dereference (&comp -> next, MDL);
		}
	}

	/* Make the state transition. */
	if (commit || !pimmediate)
		make_binding_state_transition (comp);

	/* Put the lease back on the appropriate queue.    If the lease
	   is corrupt (as detected by lease_enqueue), don't go any farther. */
	if (!lease_enqueue (comp))
		return 0;

	/* 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's next event will happen.
		   
	   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 ((commit || !pimmediate) &&
	    comp -> sort_time != MIN_TIME &&
	    comp -> sort_time > cur_time &&
	    (comp -> sort_time < comp -> pool -> next_event_time ||
	     comp -> pool -> next_event_time == MIN_TIME)) {
		comp -> pool -> next_event_time = comp -> sort_time;
		add_timeout (comp -> pool -> next_event_time,
			     pool_timer, comp -> pool,
			     (tvref_t)pool_reference,
			     (tvunref_t)pool_dereference);
	}

	if (commit) {
		if (!write_lease (comp))
			return 0;
		if (!commit_leases ())
			return 0;
	}

#if defined (FAILOVER_PROTOCOL)
	if (propogate) {
		comp -> desired_binding_state = comp -> binding_state;
		if (!dhcp_failover_queue_update (comp, pimmediate))
			return 0;
	}
#endif

	/* If the current binding state has already expired, do an
	   expiry event right now. */
	/* XXX At some point we should optimize this so that we don't
	   XXX write the lease twice, but this is a safe way to fix the
	   XXX problem for 3.0 (I hope!). */
	if ((commit || !pimmediate) &&
	    comp -> sort_time < cur_time &&
	    comp -> next_binding_state != comp -> binding_state)
		pool_timer (comp -> pool);

	return 1;
}

void make_binding_state_transition (struct lease *lease)
{
#if defined (FAILOVER_PROTOCOL)
	dhcp_failover_state_t *peer;

	if (lease && lease -> pool && lease -> pool -> failover_peer)
		peer = lease -> pool -> failover_peer;
	else
		peer = (dhcp_failover_state_t *)0;
#endif

	/* If the lease was active and is now no longer active, but isn't
	   released, then it just expired, so do the expiry event. */
	if (lease -> next_binding_state != lease -> binding_state &&
	    ((
#if defined (FAILOVER_PROTOCOL)
		    peer &&
		    lease -> binding_state == FTS_EXPIRED &&
		    (lease -> next_binding_state == FTS_FREE ||
		     lease -> next_binding_state == FTS_BACKUP)) ||
	     (!peer &&
#endif
	      lease -> binding_state == FTS_ACTIVE &&
	      lease -> next_binding_state != FTS_RELEASED))) {
#if defined (NSUPDATE)
		ddns_removals (lease);
#endif
		if (lease -> on_expiry) {
			execute_statements ((struct binding_value **)0,
					    (struct packet *)0, lease,
					    (struct client_state *)0,
					    (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);
		}
		
		/* No sense releasing a lease after it's expired. */
		if (lease -> on_release)
			executable_statement_dereference (&lease -> on_release,
							  MDL);
		/* Get rid of client-specific bindings that are only
		   correct when the lease is active. */
		if (lease -> billing_class)
			unbill_class (lease, lease -> billing_class);
		if (lease -> agent_options)
			option_chain_head_dereference (&lease -> agent_options,
						       MDL);
		if (lease -> client_hostname) {
			dfree (lease -> client_hostname, MDL);
			lease -> client_hostname = (char *)0;
		}
		if (lease -> host)
			host_dereference (&lease -> host, MDL);

		/* Send the expiry time to the peer. */
		lease -> tstp = lease -> ends;
	}

	/* If the lease was active and is now released, do the release
	   event. */
	if (lease -> next_binding_state != lease -> binding_state &&
	    ((
#if defined (FAILOVER_PROTOCOL)
		    peer &&
		    lease -> binding_state == FTS_RELEASED &&
		    (lease -> next_binding_state == FTS_FREE ||
		     lease -> next_binding_state == FTS_BACKUP)) ||
	     (!peer &&
#endif
	      lease -> binding_state == FTS_ACTIVE &&
	      lease -> next_binding_state == FTS_RELEASED))) {
#if defined (NSUPDATE)
		ddns_removals (lease);
#endif
		if (lease -> on_release) {
			execute_statements ((struct binding_value **)0,
					    (struct packet *)0, lease,
					    (struct client_state *)0,
					    (struct option_state *)0,
					    (struct option_state *)0, /* XXX */
					    &lease -> scope,
					    lease -> on_release);
			executable_statement_dereference (&lease -> on_release,
							  MDL);
		}
		
		/* A released lease can't expire. */
		if (lease -> on_expiry)
			executable_statement_dereference (&lease -> on_expiry,
							  MDL);

		/* Get rid of client-specific bindings that are only
		   correct when the lease is active. */
		if (lease -> billing_class)
			unbill_class (lease, lease -> billing_class);
		if (lease -> agent_options)
			option_chain_head_dereference (&lease -> agent_options,
						       MDL);
		if (lease -> client_hostname) {
			dfree (lease -> client_hostname, MDL);
			lease -> client_hostname = (char *)0;
		}
		if (lease -> host)
			host_dereference (&lease -> host, MDL);

		/* Send the release time (should be == cur_time) to the
		   peer. */
		lease -> tstp = lease -> ends;
	}

#if defined (DEBUG_LEASE_STATE_TRANSITIONS)
	log_debug ("lease %s moves from %s to %s",
		   piaddr (lease -> ip_addr),
		   binding_state_print (lease -> binding_state),
		   binding_state_print (lease -> next_binding_state));
#endif

	lease -> binding_state = lease -> next_binding_state;
	switch (lease -> binding_state) {
	      case FTS_ACTIVE:
#if defined (FAILOVER_PROTOCOL)
		if (lease -> pool && lease -> pool -> failover_peer)
			lease -> next_binding_state = FTS_EXPIRED;
		else
#endif
			lease -> next_binding_state = FTS_FREE;
		break;

	      case FTS_EXPIRED:
	      case FTS_RELEASED:
	      case FTS_ABANDONED:
	      case FTS_RESET:
		lease -> next_binding_state = FTS_FREE;
		/* If we are not in partner_down, leases don't go from
		   EXPIRED to FREE on a timeout - only on an update.
		   If we're in partner_down, they expire at mclt past
		   the time we entered partner_down. */
		if (lease -> pool -> failover_peer &&
		    lease -> pool -> failover_peer -> me.state == partner_down)
			lease -> tsfp =
			    (lease -> pool -> failover_peer -> me.stos +
			     lease -> pool -> failover_peer -> mclt);
		break;

	      case FTS_FREE:
	      case FTS_BACKUP:
		lease -> next_binding_state = lease -> binding_state;
		break;
	}
#if defined (DEBUG_LEASE_STATE_TRANSITIONS)
	log_debug ("lease %s: next binding state %s",
		   piaddr (lease -> ip_addr),
		   binding_state_print (lease -> next_binding_state));
#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 if (!lease -> uid_max) {
		lt -> uid = (unsigned char *)0;
	} 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 -> 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);
	}
	if (lease -> scope)
		binding_scope_reference (&lt -> scope, lease -> scope, MDL);
	if (lease -> agent_options)
		option_chain_head_reference (&lt -> agent_options,
					     lease -> agent_options, MDL);
	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;
	lt -> binding_state = lease -> binding_state;
	lt -> next_binding_state = lease -> next_binding_state;
	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;
{
	/* If there are statements to execute when the lease is
	   released, execute them. */
#if defined (NSUPDATE)
	ddns_removals (lease);
#endif
	if (lease -> on_release) {
		execute_statements ((struct binding_value **)0,
				    packet, lease, (struct client_state *)0,
				    packet -> options,