mdb.c

DHCP服务器源码

				    (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 -> binding_state != FTS_FREE &&
	    lease -> binding_state != FTS_BACKUP &&
	    lease -> binding_state != FTS_RELEASED &&
	    lease -> binding_state != FTS_EXPIRED &&
	    lease -> binding_state != FTS_RESET) {
		if (lease -> on_commit)
			executable_statement_dereference (&lease -> on_commit,
							  MDL);

		/* Blow away any bindings. */
		if (lease -> scope)
			binding_scope_dereference (&lease -> scope, MDL);
		lease -> ends = cur_time;
#if defined (FAILOVER_PROTOCOL)
		if (lease -> pool && lease -> pool -> failover_peer) {
			lease -> next_binding_state = FTS_RELEASED;
		} else {
			lease -> next_binding_state = FTS_FREE;
		}
#else
		lease -> next_binding_state = FTS_FREE;
#endif
		supersede_lease (lease, (struct lease *)0, 1, 1, 1);
	}
}

/* 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;

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

	lt -> ends = cur_time; /* XXX */
	lt -> next_binding_state = FTS_ABANDONED;

	log_error ("Abandoning IP address %s: %s",
	      piaddr (lease -> ip_addr), message);
	lt -> hardware_addr.hlen = 0;
	if (lt -> uid && lt -> uid != lt -> uid_buf)
		dfree (lt -> uid, MDL);
	lt -> uid = (unsigned char *)0;
	lt -> uid_len = 0;
	lt -> uid_max = 0;
	supersede_lease (lease, lt, 1, 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 defined (FAILOVER_PROTOCOL)
	if (lease -> pool && lease -> pool -> failover_peer) {
		lt -> next_binding_state = FTS_RESET;
	} else {
		lt -> next_binding_state = FTS_FREE;
	}
#else
	lt -> next_binding_state = FTS_FREE;
#endif
	lt -> ends = cur_time; /* XXX */
	lt -> hardware_addr.hlen = 0;
	if (lt -> uid && lt -> uid != lt -> uid_buf)
		dfree (lt -> uid, MDL);
	lt -> uid = (unsigned char *)0;
	lt -> uid_len = 0;
	lt -> uid_max = 0;
	supersede_lease (lease, lt, 1, 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 *lt = (struct lease *)0;
	struct lease *next = (struct lease *)0;
	struct lease *lease = (struct lease *)0;
	struct lease **lptr [5];
	TIME next_expiry = MAX_TIME;
	int i;

	pool = (struct pool *)vpool;

#define FREE_LEASES 0
	lptr [FREE_LEASES] = &pool -> free;
#define ACTIVE_LEASES 1
	lptr [ACTIVE_LEASES] = &pool -> active;
#define EXPIRED_LEASES 2
	lptr [EXPIRED_LEASES] = &pool -> expired;
#define ABANDONED_LEASES 3
	lptr [ABANDONED_LEASES] = &pool -> abandoned;
#define BACKUP_LEASES 4
	lptr [BACKUP_LEASES] = &pool -> backup;

	for (i = FREE_LEASES; i <= BACKUP_LEASES; i++) {
		/* If there's nothing on the queue, skip it. */
		if (!*(lptr [i]))
			continue;

#if defined (FAILOVER_PROTOCOL)
		if (pool -> failover_peer &&
		    pool -> failover_peer -> me.state != partner_down) {
			/* The secondary can't remove a lease from the
			   active state except in partner_down. */
			if (i == ACTIVE_LEASES &&
			    pool -> failover_peer -> i_am == secondary)
				continue;
			/* Leases in an expired state don't move to
			   free because of a timeout unless we're in
			   partner_down. */
			if (i == EXPIRED_LEASES)
				continue;
		}
#endif		
		lease_reference (&lease, *(lptr [i]), MDL);

		while (lease) {
			/* Remember the next lease in the list. */
			if (next)
				lease_dereference (&next, MDL);
			if (lease -> next)
				lease_reference (&next, lease -> next, MDL);

			/* If we've run out of things to expire on this list,
			   stop. */
			if (lease -> sort_time > cur_time) {
				if (lease -> sort_time < next_expiry)
					next_expiry = lease -> sort_time;
				break;
			}

			/* If there is a pending state change, and
			   this lease has gotten to the time when the
			   state change should happen, just call
			   supersede_lease on it to make the change
			   happen. */
			if (lease -> next_binding_state !=
			    lease -> binding_state)
				supersede_lease (lease,
						 (struct lease *)0, 1, 1, 1);

			lease_dereference (&lease, MDL);
			if (next)
				lease_reference (&lease, next, MDL);
		}
		if (next)
			lease_dereference (&next, MDL);
		if (lease)
			lease_dereference (&lease, MDL);
	}
	if (next_expiry != MAX_TIME) {
		pool -> next_event_time = next_expiry;
		add_timeout (pool -> next_event_time, pool_timer, pool,
			     (tvref_t)pool_reference,
			     (tvunref_t)pool_dereference);
	} else
		pool -> next_event_time = MIN_TIME;

}

/* 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 *next = (struct lease *)0;


	/* 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. */
		while (head -> n_uid) {
			lease_reference (&next, head -> n_uid, MDL);
			lease_dereference (&head, MDL);
			lease_reference (&head, next, MDL);
			lease_dereference (&next, MDL);
		}
		lease_reference (&head -> 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 *next = (struct lease *)0;

	/* 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. */
		while (head -> n_hw) {
			lease_reference (&next, head -> n_hw, MDL);
			lease_dereference (&head, MDL);
			lease_reference (&head, next, MDL);
			lease_dereference (&next, MDL);
		}

		lease_reference (&head -> 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 *next = (struct lease *)0;

	/* 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. */
		while (head -> n_hw) {
			if (head -> n_hw == lease) {
				lease_dereference (&head -> n_hw, MDL);
				if (lease -> n_hw) {
					lease_reference (&head -> n_hw,
							 lease -> n_hw, MDL);
					lease_dereference (&lease -> n_hw,
							   MDL);
				}
				break;
			}
			lease_reference (&next, head -> n_hw, MDL);
			lease_dereference (&head, MDL);
			lease_reference (&head, next, MDL);
			lease_dereference (&next, MDL);
		}
	}
	if (head)
		lease_dereference (&head, MDL);
}

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

int 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;
	struct lease **lptr [5];

	/* 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))) {
				if (!write_group (gp))
					return 0;
				++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))) {
				if (!write_host (hp))
					return 0;
				++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)) {
				if (!write_host (hp))
					++num_written;
			}
		}
	    }
	    log_info ("Wrote %d new dynamic host decls to leases file.",
		      num_written);
	}

#if defined (FAILOVER_PROTOCOL)
	/* Write all the failover states. */
	if (!dhcp_failover_write_all_states ())
		return 0;
#endif

	/* Write all the leases. */
	num_written = 0;
	for (s = shared_networks; s; s = s -> next) {