openldap/servers/lloadd/client.c
2020-11-17 17:55:46 +00:00

385 lines
11 KiB
C

/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 1998-2020 The OpenLDAP Foundation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in the file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
#include "portable.h"
#include <ac/socket.h>
#include <ac/errno.h>
#include <ac/string.h>
#include <ac/time.h>
#include <ac/unistd.h>
#include "lutil.h"
#include "slap.h"
slap_c_head clients = LDAP_CIRCLEQ_HEAD_INITIALIZER( clients );
ldap_pvt_thread_mutex_t clients_mutex;
typedef int (*RequestHandler)( Connection *c, Operation *op );
static void
client_read_cb( evutil_socket_t s, short what, void *arg )
{
Connection *c = arg;
BerElement *ber;
ber_tag_t tag;
ber_len_t len;
CONNECTION_LOCK(c);
if ( !c->c_live ) {
event_del( c->c_read_event );
CONNECTION_UNLOCK(c);
return;
}
Debug( LDAP_DEBUG_CONNS, "client_read_cb: "
"connection %lu ready to read\n",
c->c_connid );
ber = c->c_currentber;
if ( ber == NULL && (ber = ber_alloc()) == NULL ) {
Debug( LDAP_DEBUG_ANY, "client_read_cb: "
"ber_alloc failed\n" );
CLIENT_DESTROY(c);
return;
}
c->c_currentber = ber;
tag = ber_get_next( c->c_sb, &len, ber );
if ( tag != LDAP_TAG_MESSAGE ) {
int err = sock_errno();
if ( err != EWOULDBLOCK && err != EAGAIN ) {
if ( err ) {
char ebuf[128];
Debug( LDAP_DEBUG_ANY, "client_read_cb: "
"ber_get_next on fd %d failed errno=%d (%s)\n",
c->c_fd, err,
sock_errstr( err, ebuf, sizeof(ebuf) ) );
}
c->c_currentber = NULL;
ber_free( ber, 1 );
event_del( c->c_read_event );
CLIENT_DESTROY(c);
return;
}
event_add( c->c_read_event, NULL );
CONNECTION_UNLOCK(c);
return;
}
if ( !slap_conn_max_pdus_per_cycle ||
ldap_pvt_thread_pool_submit(
&connection_pool, handle_requests, c ) ) {
/* If we're overloaded or configured as such, process one and resume in
* the next cycle.
*
* handle_one_request re-locks the mutex in the
* process, need to test it's still alive */
if ( handle_one_request( c ) == LDAP_SUCCESS ) {
CLIENT_UNLOCK_OR_DESTROY(c);
}
return;
}
event_del( c->c_read_event );
CONNECTION_UNLOCK(c);
return;
}
void *
handle_requests( void *ctx, void *arg )
{
Connection *c = arg;
int requests_handled = 0;
CONNECTION_LOCK(c);
for ( ; requests_handled < slap_conn_max_pdus_per_cycle;
requests_handled++ ) {
BerElement *ber;
ber_tag_t tag;
ber_len_t len;
/* handle_one_response may unlock the connection in the process, we
* need to expect that might be our responsibility to destroy it */
if ( handle_one_request( c ) ) {
/* Error, connection is unlocked and might already have been
* destroyed */
return NULL;
}
/* Otherwise, handle_one_request leaves the connection locked */
if ( (ber = ber_alloc()) == NULL ) {
Debug( LDAP_DEBUG_ANY, "client_read_cb: "
"ber_alloc failed\n" );
CLIENT_DESTROY(c);
return NULL;
}
c->c_currentber = ber;
tag = ber_get_next( c->c_sb, &len, ber );
if ( tag != LDAP_TAG_MESSAGE ) {
int err = sock_errno();
if ( err != EWOULDBLOCK && err != EAGAIN ) {
if ( err ) {
char ebuf[128];
Debug( LDAP_DEBUG_ANY, "handle_requests: "
"ber_get_next on fd %d failed errno=%d (%s)\n",
c->c_fd, err,
sock_errstr( err, ebuf, sizeof(ebuf) ) );
}
c->c_currentber = NULL;
ber_free( ber, 1 );
CLIENT_DESTROY(c);
return NULL;
}
break;
}
}
event_add( c->c_read_event, NULL );
CLIENT_UNLOCK_OR_DESTROY(c);
return NULL;
}
int
handle_one_request( Connection *c )
{
BerElement *ber;
Operation *op = NULL;
RequestHandler handler = NULL;
ber = c->c_currentber;
c->c_currentber = NULL;
op = operation_init( c, ber );
if ( !op ) {
Debug( LDAP_DEBUG_ANY, "handle_one_request: "
"operation_init failed\n" );
CLIENT_DESTROY(c);
ber_free( ber, 1 );
return -1;
}
switch ( op->o_tag ) {
case LDAP_REQ_UNBIND:
/* There is never a response for this operation */
operation_destroy_from_client( op );
Debug( LDAP_DEBUG_STATS, "handle_one_request: "
"received unbind, closing client connid=%lu\n",
c->c_connid );
CLIENT_DESTROY(c);
return -1;
case LDAP_REQ_BIND:
handler = client_bind;
break;
case LDAP_REQ_ABANDON:
/* FIXME: We need to be able to abandon a Bind request, handling
* ExOps (esp. Cancel) will be different */
handler = request_abandon;
break;
default:
if ( c->c_state == SLAP_C_BINDING ) {
op->o_client_refcnt++;
CONNECTION_UNLOCK_INCREF(c);
operation_send_reject(
op, LDAP_PROTOCOL_ERROR, "bind in progress", 0 );
CONNECTION_LOCK_DECREF(c);
op->o_client_refcnt--;
operation_destroy_from_client( op );
return LDAP_SUCCESS;
}
handler = request_process;
break;
}
return handler( c, op );
}
void
client_write_cb( evutil_socket_t s, short what, void *arg )
{
Connection *c = arg;
CONNECTION_LOCK(c);
if ( !c->c_live ) {
CONNECTION_UNLOCK(c);
return;
}
CONNECTION_UNLOCK_INCREF(c);
ldap_pvt_thread_mutex_lock( &c->c_io_mutex );
Debug( LDAP_DEBUG_CONNS, "client_write_cb: "
"have something to write to client %lu\n",
c->c_connid );
/* We might have been beaten to flushing the data by another thread */
if ( c->c_pendingber && ber_flush( c->c_sb, c->c_pendingber, 1 ) ) {
int err = sock_errno();
if ( err != EWOULDBLOCK && err != EAGAIN ) {
char ebuf[128];
ldap_pvt_thread_mutex_unlock( &c->c_io_mutex );
Debug( LDAP_DEBUG_ANY, "client_write_cb: "
"ber_flush on fd %d failed errno=%d (%s)\n",
c->c_fd, err, sock_errstr( err, ebuf, sizeof(ebuf) ) );
CLIENT_LOCK_DESTROY(c);
return;
}
event_add( c->c_write_event, NULL );
} else {
c->c_pendingber = NULL;
}
ldap_pvt_thread_mutex_unlock( &c->c_io_mutex );
CONNECTION_LOCK_DECREF(c);
CLIENT_UNLOCK_OR_DESTROY(c);
}
Connection *
client_init(
ber_socket_t s,
Listener *listener,
const char *peername,
struct event_base *base,
int flags )
{
Connection *c;
struct event *event;
assert( listener != NULL );
c = connection_init( s, peername, flags );
c->c_state = SLAP_C_READY;
event = event_new( base, s, EV_READ|EV_PERSIST, client_read_cb, c );
if ( !event ) {
Debug( LDAP_DEBUG_ANY, "client_init: "
"Read event could not be allocated\n" );
goto fail;
}
event_add( event, NULL );
c->c_read_event = event;
event = event_new( base, s, EV_WRITE, client_write_cb, c );
if ( !event ) {
Debug( LDAP_DEBUG_ANY, "client_init: "
"Write event could not be allocated\n" );
goto fail;
}
/* We only register the write event when we have data pending */
c->c_write_event = event;
c->c_private = listener;
/* There should be no lock inversion yet since no other thread could
* approach it from clients side */
ldap_pvt_thread_mutex_lock( &clients_mutex );
LDAP_CIRCLEQ_INSERT_TAIL( &clients, c, c_next );
ldap_pvt_thread_mutex_unlock( &clients_mutex );
CONNECTION_UNLOCK(c);
return c;
fail:
if ( c->c_write_event ) {
event_free( c->c_write_event );
c->c_write_event = NULL;
}
if ( c->c_read_event ) {
event_free( c->c_read_event );
c->c_read_event = NULL;
}
c->c_state = SLAP_C_INVALID;
connection_destroy( c );
return NULL;
}
void
client_destroy( Connection *c )
{
enum sc_state state;
Debug( LDAP_DEBUG_CONNS, "client_destroy: "
"destroying client connid=%lu\n",
c->c_connid );
assert( c->c_state != SLAP_C_INVALID );
state = c->c_state;
c->c_state = SLAP_C_INVALID;
if ( c->c_read_event ) {
event_free( c->c_read_event );
c->c_read_event = NULL;
}
if ( c->c_write_event ) {
event_free( c->c_write_event );
c->c_write_event = NULL;
}
if ( state != SLAP_C_CLOSING ) {
ldap_pvt_thread_mutex_lock( &clients_mutex );
LDAP_CIRCLEQ_REMOVE( &clients, c, c_next );
ldap_pvt_thread_mutex_unlock( &clients_mutex );
}
client_reset( c );
/*
* If we attempted to destroy any operations, we might have lent a new
* refcnt token for a thread that raced us to that, let them call us again
* later
*/
assert( c->c_refcnt >= 0 );
if ( c->c_refcnt ) {
c->c_state = SLAP_C_CLOSING;
Debug( LDAP_DEBUG_CONNS, "client_destroy: "
"connid=%lu aborting with refcnt=%d\n",
c->c_connid, c->c_refcnt );
CONNECTION_UNLOCK(c);
return;
}
connection_destroy( c );
}
void
clients_destroy( void )
{
ldap_pvt_thread_mutex_lock( &clients_mutex );
while ( !LDAP_CIRCLEQ_EMPTY( &clients ) ) {
Connection *c = LDAP_CIRCLEQ_FIRST( &clients );
ldap_pvt_thread_mutex_unlock( &clients_mutex );
CONNECTION_LOCK(c);
/* We have shut down all processing, a dying connection connection
* should have been reclaimed by now! */
assert( c->c_live );
/* Upstream connections have already been destroyed, there should be no
* ops left */
assert( !c->c_ops );
CLIENT_DESTROY(c);
ldap_pvt_thread_mutex_lock( &clients_mutex );
}
ldap_pvt_thread_mutex_unlock( &clients_mutex );
}