#include "sql_attribute.h"
#include <daemon.h>
+#include <utils/mutex.h>
typedef struct private_sql_attribute_t private_sql_attribute_t;
* database connection
*/
database_t *db;
+
+ /**
+ * mutex to simulate transactions
+ */
+ mutex_t *mutex;
};
/**
host_t *ip = NULL;
int lease;
- POS;
+ /* transaction simulation, see create_lease() */
+ this->mutex->lock(this->mutex);
+
+ /* select a lease for "id" which still valid */
e = this->db->query(this->db,
"SELECT l.id, l.address FROM leases AS l "
"JOIN pools AS p ON l.pool = p.id "
{
if (e->enumerate(e, &lease, &address))
{
+ /* found one, set the lease to active */
if (this->db->execute(this->db, NULL,
"UPDATE leases SET release = NULL WHERE id = ?",
DB_INT, lease) > 0)
{
- POS;
ip = ip_from_chunk(address);
+ DBG1(DBG_CFG, "reassigning address from valid lease "
+ "from pool %s", name);
}
}
e->destroy(e);
}
+ this->mutex->unlock(this->mutex);
return ip;
}
static host_t* create_lease(private_sql_attribute_t *this,
char *name, identification_t *id)
{
- enumerator_t *e, *f;
+ enumerator_t *e;
chunk_t address;
host_t *ip = NULL;
int pool, identity = 0;
- POS;
+ bool new = FALSE;
+
+ /* we currently do not use database transactions. While this would be
+ * the clean way, there is no real advantage, but some disadvantages:
+ * - we would require InnoDB for mysql, as MyISAM does not support trans.
+ * - the mysql plugin uses connection pooling, and we would need a
+ * mechanism to lock transactions to a single connection.
+ */
+ this->mutex->lock(this->mutex);
+ /* find an address which has outdated leases only */
e = this->db->query(this->db,
- "SELECT id, next FROM pools WHERE name = ? AND next <= end",
- DB_TEXT, name,
- DB_INT, DB_BLOB);
- if (!e)
+ "SELECT pool, address FROM leases "
+ "JOIN pools ON leases.pool = pools.id "
+ "WHERE name = ? "
+ "GROUP BY address HAVING release NOTNULL "
+ "AND MAX(release) < ? + pools.timeout LIMIT 1",
+ DB_TEXT, name, DB_UINT, time(NULL),
+ DB_INT, DB_BLOB);
+
+ if (!e || !e->enumerate(e, &pool, &address))
{
- return NULL;
+ DESTROY_IF(e);
+ /* no outdated lease found, acquire new address */
+ e = this->db->query(this->db,
+ "SELECT id, next FROM pools WHERE name = ? AND next <= end",
+ DB_TEXT, name,
+ DB_INT, DB_BLOB);
+ if (!e || !e->enumerate(e, &pool, &address))
+ {
+ /* pool seems full */
+ DESTROY_IF(e);
+ this->mutex->unlock(this->mutex);
+ return NULL;
+ }
+ new = TRUE;
}
- if (e->enumerate(e, &pool, &address))
- {
- f = this->db->query(this->db,
+ address = chunk_clonea(address);
+ e->destroy(e);
+
+ /* look for peer identity in the identities table */
+ e = this->db->query(this->db,
"SELECT id FROM identities WHERE type = ? AND data = ?",
DB_INT, id->get_type(id), DB_BLOB, id->get_encoding(id),
DB_INT);
- if (f)
- {
- if (!f->enumerate(f, &identity))
- {
- this->db->execute(this->db, &identity,
+ if (!e || !e->enumerate(e, &identity))
+ {
+ DESTROY_IF(e);
+ /* not found, insert new one */
+ this->db->execute(this->db, &identity,
"INSERT INTO identities (type, data) VALUES (?, ?)",
DB_INT, id->get_type(id), DB_BLOB, id->get_encoding(id));
- }
- f->destroy(f);
- }
- if (identity)
+ }
+ else
+ {
+ e->destroy(e);
+ }
+ /* if we have an identity, insert a new lease */
+ if (identity)
+ {
+ if (this->db->execute(this->db, NULL,
+ "INSERT INTO leases (pool, address, identity, acquire) "
+ "VALUES (?, ?, ?, ?)",
+ DB_INT, pool, DB_BLOB, address, DB_INT, identity,
+ DB_UINT, time(NULL)) > 0)
{
- if (this->db->execute(this->db, NULL,
- "INSERT INTO leases "
- "(pool, address, identity) VALUES (?, ?, ?)",
- DB_INT, pool, DB_BLOB, address, DB_INT, identity) > 0)
- {
- POS;
- ip = ip_from_chunk(address);
+ ip = ip_from_chunk(address);
+ if (new)
+ { /* update next address, as we have consumed one */
increment_chunk(address);
this->db->execute(this->db, NULL,
"UPDATE pools set next = ? WHERE id = ?",
DB_BLOB, address, DB_INT, pool);
+ DBG1(DBG_CFG, "assigning lease with new address "
+ "from pool %s", name);
+ }
+ else
+ {
+ DBG1(DBG_CFG, "reassigning address from expired lease "
+ "from pool %s", name);
}
}
}
- e->destroy(e);
+ this->mutex->unlock(this->mutex);
return ip;
}
char *name, host_t *address)
{
if (this->db->execute(this->db, NULL,
- "UPDATE leases SET release = DATE('NOW') WHERE "
+ "UPDATE leases SET release = ? WHERE "
"pool IN (SELECT id FROM pools WHERE name = ?) AND "
- "address = ? "
- "ORDER BY acquire LIMIT 1",
+ "address = ? AND release ISNULL",
+ DB_UINT, time(NULL),
DB_TEXT, name, DB_BLOB, address->get_address(address)) > 0)
{
- POS;
return TRUE;
}
return FALSE;
*/
static void destroy(private_sql_attribute_t *this)
{
+ this->mutex->destroy(this->mutex);
free(this);
}
this->public.destroy = (void(*)(sql_attribute_t*))destroy;
this->db = db;
+ this->mutex = mutex_create(MUTEX_DEFAULT);
return &this->public;
}