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experimental and untested reimplementation of sql based IP pool

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uses address preallocation and separate address/lease tables for linear lookup time
This commit is contained in:
Martin Willi
2008-07-22 14:56:15 +00:00
parent 32f5ee159e
commit f7198e7e8c
4 changed files with 319 additions and 251 deletions
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src/charon/plugins/sql/sql_attribute.c
+160 -178
View File
@@ -18,7 +18,6 @@
#include "sql_attribute.h"
#include <daemon.h>
#include <utils/mutex.h>
typedef struct private_sql_attribute_t private_sql_attribute_t;
@@ -36,187 +35,152 @@ struct private_sql_attribute_t {
* database connection
*/
database_t *db;
/**
* mutex to simulate transactions
*/
mutex_t *mutex;
};
/**
* convert a address blob to an ip of the correct family
/**
* read a host_t address from the addresses table
*/
static host_t *ip_from_chunk(chunk_t address)
static host_t *host_from_chunk(chunk_t chunk)
{
switch (address.len)
switch (chunk.len)
{
case 4:
return host_create_from_chunk(AF_INET, address, 0);
return host_create_from_chunk(AF_INET, chunk, 0);
case 16:
return host_create_from_chunk(AF_INET6, address, 0);
return host_create_from_chunk(AF_INET6, chunk, 0);
default:
return NULL;
}
}
/**
* increment a chunk, as it would reprensent a network order integer
*/
static void increment_chunk(chunk_t chunk)
{
int i;
for (i = chunk.len - 1; i >= 0; i--)
{
if (++chunk.ptr[i] != 0)
{
return;
}
}
}
/**
* Lookup if we have an existing lease
* lookup/insert an identity
*/
static host_t* get_lease(private_sql_attribute_t *this,
char *name, identification_t *id)
static u_int get_identity(private_sql_attribute_t *this, identification_t *id)
{
enumerator_t *e;
chunk_t address;
host_t *ip = NULL;
int lease;
/* 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 "
"JOIN identities AS i ON l.identity = i.id "
"WHERE p.name = ? AND i.type = ? AND i.data = ? "
"AND (l.released IS NULL OR p.timeout = 0 "
" OR (l.released >= (? - p.timeout))) "
"ORDER BY l.acquired LIMIT 1", DB_TEXT, name,
DB_INT, id->get_type(id), DB_BLOB, id->get_encoding(id),
DB_UINT, time(NULL),
DB_UINT, DB_BLOB);
if (e)
{
if (e->enumerate(e, &lease, &address))
{
/* found one, set the lease to active */
if (this->db->execute(this->db, NULL,
"UPDATE leases SET released = NULL WHERE id = ?",
DB_UINT, lease) > 0)
{
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;
}
/**
* Create a new lease entry for client
*/
static host_t* create_lease(private_sql_attribute_t *this,
char *name, identification_t *id)
{
enumerator_t *e;
chunk_t address;
host_t *ip = NULL;
u_int pool, identity = 0, released, timeout;
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. The HAVING clause filters
* out leases which are active (released = NULL) or not expired */
e = this->db->query(this->db,
"SELECT pool, address, released, timeout FROM leases "
"JOIN pools ON leases.pool = pools.id "
"WHERE name = ? and timeout > 0 "
"GROUP BY address HAVING COUNT(released) = COUNT(*) "
"AND MAX(released) < (? - timeout) LIMIT 1",
DB_TEXT, name, DB_UINT, time(NULL),
DB_UINT, DB_BLOB, DB_UINT, DB_UINT);
if (!e || !e->enumerate(e, &pool, &address, &released, &timeout))
{
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_UINT, DB_BLOB);
if (!e || !e->enumerate(e, &pool, &address))
{
/* pool seems full */
DESTROY_IF(e);
this->mutex->unlock(this->mutex);
return NULL;
}
new = TRUE;
}
address = chunk_clonea(address);
e->destroy(e);
u_int row;
/* 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_UINT);
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));
}
else
if (e && e->enumerate(e, &row))
{
e->destroy(e);
return row;
}
/* if we have an identity, insert a new lease */
if (identity)
DESTROY_IF(e);
/* not found, insert new one */
if (this->db->execute(this->db, &row,
"INSERT INTO identities (type, data) VALUES (?, ?)",
DB_INT, id->get_type(id), DB_BLOB, id->get_encoding(id)) == 1)
{
if (this->db->execute(this->db, NULL,
"INSERT INTO leases (pool, address, identity, acquired) "
"VALUES (?, ?, ?, ?)",
DB_UINT, pool, DB_BLOB, address, DB_UINT, identity,
DB_UINT, time(NULL)) > 0)
return row;
}
return 0;
}
/**
* Lookup pool by name
*/
static u_int get_pool(private_sql_attribute_t *this, char *name, u_int *timeout)
{
enumerator_t *e;
u_int pool;
e = this->db->query(this->db, "SELECT id, timeout FROM pools WHERE name = ?",
DB_TEXT, name, DB_UINT, DB_UINT);
if (e && e->enumerate(e, &pool, timeout))
{
e->destroy(e);
return pool;
}
DBG1(DBG_CFG, "ip pool '%s' not found");
return 0;
}
/**
* Lookup a lease
*/
static host_t *get_address(private_sql_attribute_t *this, char *name,
u_int pool, u_int timeout, u_int identity)
{
enumerator_t *e;
u_int id;
chunk_t address;
host_t *host;
time_t now = time(NULL);
/* We check for leases for that identity first and for other expired
* leases afterwards. We select an address as a candidate, but double
* check if it is still valid in the update. This allows us to work
* without locking. */
/* check for an existing lease for that identity */
while (TRUE)
{
e = this->db->query(this->db,
"SELECT id, address FROM addresses "
"WHERE pool = ? AND identity = ? AND released != 0 LIMIT 1",
DB_UINT, pool, DB_UINT, identity, DB_UINT, DB_BLOB);
if (!e || !e->enumerate(e, &id, &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_UINT, pool);
DBG1(DBG_CFG, "assigning lease with new address "
"from pool '%s'", name);
}
else
DESTROY_IF(e);
break;
}
address = chunk_clonea(address);
e->destroy(e);
if (this->db->execute(this->db, NULL,
"UPDATE addresses SET acquired = ?, released = 0 "
"WHERE id = ? AND identity = ? AND released != 0",
DB_UINT, now, DB_UINT, id, DB_UINT, identity) > 0)
{
host = host_from_chunk(address);
if (host)
{
DBG1(DBG_CFG, "reassigning address from expired lease "
"from pool '%s'", name);
DBG1(DBG_CFG, "acquired existing lease "
"for address %H in pool '%s'", host, name);
return host;
}
}
}
this->mutex->unlock(this->mutex);
return ip;
/* check for an expired lease */
while (TRUE)
{
e = this->db->query(this->db,
"SELECT id, address FROM addresses "
"WHERE pool = ? AND released != 0 AND released < ? LIMIT 1",
DB_UINT, pool, DB_UINT, now - timeout, DB_UINT, DB_BLOB);
if (!e || !e->enumerate(e, &id, &address))
{
DESTROY_IF(e);
break;
}
address = chunk_clonea(address);
e->destroy(e);
if (this->db->execute(this->db, NULL,
"UPDATE addresses SET "
"acquired = ?, released = 0, identity = ? "
"WHERE id = ? AND released != 0 AND released < ?",
DB_UINT, now, DB_UINT, identity,
DB_UINT, id, DB_UINT, now - timeout) > 0)
{
host = host_from_chunk(address);
if (host)
{
DBG1(DBG_CFG, "acquired new lease "
"for address %H in pool '%s'", host, name);
return host;
}
}
}
DBG1(DBG_CFG, "no available address found in pool '%s'", name);
return 0;
}
/**
@@ -227,24 +191,28 @@ static host_t* acquire_address(private_sql_attribute_t *this,
auth_info_t *auth, host_t *requested)
{
enumerator_t *enumerator;
host_t *ip = NULL;
u_int pool, timeout, identity;
host_t *address = NULL;
enumerator = enumerator_create_token(name, ",", " ");
while (enumerator->enumerate(enumerator, &name))
identity = get_identity(this, id);
if (identity)
{
ip = get_lease(this, name, id);
if (ip)
enumerator = enumerator_create_token(name, ",", " ");
while (enumerator->enumerate(enumerator, &name))
{
break;
}
ip = create_lease(this, name, id);
if (ip)
{
break;
pool = get_pool(this, name, &timeout);
if (pool)
{
address = get_address(this, name, pool, timeout, identity);
if (address)
{
break;
}
}
}
enumerator->destroy(enumerator);
}
enumerator->destroy(enumerator);
return ip;
return address;
}
/**
@@ -254,23 +222,35 @@ static bool release_address(private_sql_attribute_t *this,
char *name, host_t *address)
{
enumerator_t *enumerator;
bool found = FALSE;
time_t now = time(NULL);
enumerator = enumerator_create_token(name, ",", " ");
while (enumerator->enumerate(enumerator, &name))
{
if (this->db->execute(this->db, NULL,
"UPDATE leases SET released = ? WHERE "
"pool IN (SELECT id FROM pools WHERE name = ?) AND "
"address = ? AND released IS NULL",
DB_UINT, time(NULL),
DB_TEXT, name, DB_BLOB, address->get_address(address)) > 0)
u_int pool, timeout;
pool = get_pool(this, name, &timeout);
if (pool)
{
enumerator->destroy(enumerator);
return TRUE;
if (this->db->execute(this->db, NULL,
"INSERT INTO leases (address, identity, acquired, released)"
" SELECT id, identity, acquired, ? FROM addresses "
" WHERE pool = ? AND address = ?",
DB_UINT, now, DB_UINT, pool,
DB_BLOB, address->get_address(address)) > 0 &&
this->db->execute(this->db, NULL,
"UPDATE addresses SET released = ? WHERE "
"pool = ? AND address = ?", DB_UINT, time(NULL),
DB_UINT, pool, DB_BLOB, address->get_address(address)) > 0)
{
found = TRUE;
break;
}
}
}
enumerator->destroy(enumerator);
return FALSE;
return found;
}
/**
@@ -278,7 +258,6 @@ static bool release_address(private_sql_attribute_t *this,
*/
static void destroy(private_sql_attribute_t *this)
{
this->mutex->destroy(this->mutex);
free(this);
}
@@ -288,19 +267,22 @@ static void destroy(private_sql_attribute_t *this)
sql_attribute_t *sql_attribute_create(database_t *db)
{
private_sql_attribute_t *this = malloc_thing(private_sql_attribute_t);
time_t now = time(NULL);
this->public.provider.acquire_address = (host_t*(*)(attribute_provider_t *this, char*, identification_t *,auth_info_t *, host_t *))acquire_address;
this->public.provider.release_address = (bool(*)(attribute_provider_t *this, char*,host_t *))release_address;
this->public.destroy = (void(*)(sql_attribute_t*))destroy;
this->db = db;
this->mutex = mutex_create(MUTEX_DEFAULT);
/* close any "online" leases in the case we crashed */
this->db->execute(this->db, NULL,
"UPDATE leases SET released = ? WHERE released IS NULL",
DB_UINT, time(NULL));
"INSERT INTO leases (address, identity, acquired, released)"
" SELECT id, identity, acquired, ? FROM addresses "
" WHERE released = 0", DB_UINT, now);
this->db->execute(this->db, NULL,
"UPDATE addresses SET released = ? WHERE released = 0",
DB_UINT, now);
return &this->public;
}