1 files changed, 363 insertions, 0 deletions
diff --git a/servers/slapd/txn.c b/servers/slapd/txn.c
new file mode 100644
index 0000000..d81de95
--- /dev/null
+++ b/servers/slapd/txn.c
@@ -0,0 +1,363 @@
+/* txn.c - LDAP Transactions */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 1998-2022 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 <stdio.h>
+
+#include <ac/socket.h>
+#include <ac/string.h>
+#include <ac/unistd.h>
+
+#include "slap.h"
+
+#include <lber_pvt.h>
+#include <lutil.h>
+
+const struct berval slap_EXOP_TXN_START = BER_BVC(LDAP_EXOP_TXN_START);
+const struct berval slap_EXOP_TXN_END = BER_BVC(LDAP_EXOP_TXN_END);
+
+int txn_start_extop(
+	Operation *op, SlapReply *rs )
+{
+	int rc;
+	struct berval *bv;
+
+	Debug( LDAP_DEBUG_STATS, "%s TXN START\n",
+		op->o_log_prefix );
+
+	if( op->ore_reqdata != NULL ) {
+		rs->sr_text = "no request data expected";
+		return LDAP_PROTOCOL_ERROR;
+	}
+
+	op->o_bd = op->o_conn->c_authz_backend;
+	if( backend_check_restrictions( op, rs,
+		(struct berval *)&slap_EXOP_TXN_START ) != LDAP_SUCCESS )
+	{
+		return rs->sr_err;
+	}
+
+	/* acquire connection lock */
+	ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
+
+	if( op->o_conn->c_txn != CONN_TXN_INACTIVE ) {
+		rs->sr_text = "Too many transactions";
+		rc = LDAP_BUSY;
+		goto done;
+	}
+
+	assert( op->o_conn->c_txn_backend == NULL );
+	op->o_conn->c_txn = CONN_TXN_SPECIFY;
+
+	bv = (struct berval *) ch_malloc( sizeof (struct berval) );
+	bv->bv_len = 0;
+	bv->bv_val = NULL;
+
+	rs->sr_rspdata = bv;
+	rc = LDAP_SUCCESS;
+
+done:
+	/* release connection lock */
+	ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
+	return rc;
+}
+
+int txn_spec_ctrl(
+	Operation *op, SlapReply *rs, LDAPControl *ctrl )
+{
+	if ( !ctrl->ldctl_iscritical ) {
+		rs->sr_text = "txnSpec control must be marked critical";
+		return LDAP_PROTOCOL_ERROR;
+	}
+	if( op->o_txnSpec ) {
+		rs->sr_text = "txnSpec control provided multiple times";
+		return LDAP_PROTOCOL_ERROR;
+	}
+
+	if ( ctrl->ldctl_value.bv_val == NULL ) {
+		rs->sr_text = "no transaction identifier provided";
+		return LDAP_PROTOCOL_ERROR;
+	}
+	if ( ctrl->ldctl_value.bv_len != 0 ) {
+		rs->sr_text = "invalid transaction identifier";
+		return LDAP_TXN_ID_INVALID;
+	}
+
+	if ( op->o_preread ) { /* temporary limitation */
+		rs->sr_text = "cannot perform pre-read in transaction";
+		return LDAP_UNWILLING_TO_PERFORM;
+	} 
+	if ( op->o_postread ) { /* temporary limitation */
+		rs->sr_text = "cannot perform post-read in transaction";
+		return LDAP_UNWILLING_TO_PERFORM;
+	}
+
+	op->o_txnSpec = SLAP_CONTROL_CRITICAL;
+	return LDAP_SUCCESS;
+}
+
+typedef struct txn_rctrls {
+	struct txn_rctrls *tr_next;
+	ber_int_t	tr_msgid;
+	LDAPControl ** tr_ctrls;
+} txn_rctrls;
+
+static int txn_result( Operation *op, SlapReply *rs )
+{
+	if ( rs->sr_ctrls ) {
+		txn_rctrls **t0, *tr;
+		for ( t0 = (txn_rctrls **) &op->o_callback->sc_private; *t0;
+			t0 = &(*t0)->tr_next )
+			;
+		tr = op->o_tmpalloc( sizeof( txn_rctrls ), op->o_tmpmemctx );
+		tr->tr_next = NULL;
+		*t0 = tr;
+		tr->tr_msgid = op->o_msgid;
+		tr->tr_ctrls = ldap_controls_dup( rs->sr_ctrls );
+	}
+	return rs->sr_err;
+}
+
+static int txn_put_ctrls( Operation *op, BerElement *ber, txn_rctrls *tr )
+{
+	txn_rctrls *next;
+	int i;
+	ber_printf( ber, "{" );
+	for ( ; tr; tr  = next ) {
+		next = tr->tr_next;
+		ber_printf( ber, "{it{", tr->tr_msgid, LDAP_TAG_CONTROLS );
+		for ( i = 0; tr->tr_ctrls[i]; i++ )
+			ldap_pvt_put_control( tr->tr_ctrls[i], ber );
+		ber_printf( ber, "}}" );
+		ldap_controls_free( tr->tr_ctrls );
+		op->o_tmpfree( tr, op->o_tmpmemctx );
+	}
+	ber_printf( ber, "}" );
+	return 0;
+}
+
+int txn_end_extop(
+	Operation *op, SlapReply *rs )
+{
+	int rc;
+	BerElementBuffer berbuf;
+	BerElement *ber = (BerElement *)&berbuf;
+	ber_tag_t tag;
+	ber_len_t len;
+	ber_int_t commit=1;
+	struct berval txnid;
+	Operation *o, *p;
+	Connection *c = op->o_conn;
+
+	Debug( LDAP_DEBUG_STATS, "%s TXN END\n",
+		op->o_log_prefix );
+
+	if( op->ore_reqdata == NULL ) {
+		rs->sr_text = "request data expected";
+		return LDAP_PROTOCOL_ERROR;
+	}
+	if( op->ore_reqdata->bv_len == 0 ) {
+		rs->sr_text = "empty request data";
+		return LDAP_PROTOCOL_ERROR;
+	}
+
+	op->o_bd = c->c_authz_backend;
+	if( backend_check_restrictions( op, rs,
+		(struct berval *)&slap_EXOP_TXN_END ) != LDAP_SUCCESS )
+	{
+		return rs->sr_err;
+	}
+
+	ber_init2( ber, op->ore_reqdata, 0 );
+
+	tag = ber_scanf( ber, "{" /*}*/ );
+	if( tag == LBER_ERROR ) {
+		rs->sr_text = "request data decoding error";
+		return LDAP_PROTOCOL_ERROR;
+	}
+
+	tag = ber_peek_tag( ber, &len );
+	if( tag == LBER_BOOLEAN ) {
+		tag = ber_scanf( ber, "b", &commit );
+		if( tag == LBER_ERROR ) {
+			rs->sr_text = "request data decoding error";
+			return LDAP_PROTOCOL_ERROR;
+		}
+	}
+
+	tag = ber_scanf( ber, /*{*/ "m}", &txnid );
+	if( tag == LBER_ERROR ) {
+		rs->sr_text = "request data decoding error";
+		return LDAP_PROTOCOL_ERROR;
+	}
+
+	if( txnid.bv_len ) {
+		rs->sr_text = "invalid transaction identifier";
+		return LDAP_TXN_ID_INVALID;
+	}
+
+	/* acquire connection lock */
+	ldap_pvt_thread_mutex_lock( &c->c_mutex );
+
+	if( c->c_txn != CONN_TXN_SPECIFY ) {
+		rs->sr_text = "invalid transaction identifier";
+		rc = LDAP_TXN_ID_INVALID;
+		goto done;
+	}
+	c->c_txn = CONN_TXN_SETTLE;
+
+	if( commit ) {
+		slap_callback cb = {0};
+		OpExtra *txn = NULL;
+		if ( op->o_abandon ) {
+			goto drain;
+		}
+
+		if( LDAP_STAILQ_EMPTY(&c->c_txn_ops) ) {
+			/* no updates to commit */
+			rs->sr_text = "no updates to commit";
+			rc = LDAP_OPERATIONS_ERROR;
+			goto settled;
+		}
+
+		cb.sc_response = txn_result;
+		LDAP_STAILQ_FOREACH( o, &c->c_txn_ops, o_next ) {
+			o->o_bd = c->c_txn_backend;
+			p = o;
+			if ( !txn ) {
+				rc = o->o_bd->bd_info->bi_op_txn(o, SLAP_TXN_BEGIN, &txn );
+				if ( rc ) {
+					rs->sr_text = "couldn't start DB transaction";
+					rc = LDAP_OTHER;
+					goto drain;
+				}
+			} else {
+				LDAP_SLIST_INSERT_HEAD( &o->o_extra, txn, oe_next );
+			}
+			cb.sc_next = o->o_callback;
+			o->o_callback = &cb;
+			{
+				SlapReply rs = {REP_RESULT};
+				int opidx = slap_req2op( o->o_tag );
+				assert( opidx != SLAP_OP_LAST );
+				o->o_threadctx = op->o_threadctx;
+				o->o_tid = op->o_tid;
+				ldap_pvt_thread_mutex_unlock( &c->c_mutex );
+				rc = (&o->o_bd->bd_info->bi_op_bind)[opidx]( o, &rs );
+				ldap_pvt_thread_mutex_lock( &c->c_mutex );
+			}
+			if ( rc ) {
+				struct berval *bv = NULL;
+				BerElementBuffer berbuf;
+				BerElement *ber = (BerElement *)&berbuf;
+
+				ber_init_w_nullc( ber, LBER_USE_DER );
+				ber_printf( ber, "{i", o->o_msgid );
+				if ( cb.sc_private )
+					txn_put_ctrls( op, ber, cb.sc_private );
+				ber_printf( ber, "}" );
+				ber_flatten( ber, &bv );
+				ber_free_buf( ber );
+				rs->sr_rspdata = bv;
+				o->o_bd->bd_info->bi_op_txn(o, SLAP_TXN_ABORT, &txn );
+				goto drain;
+			}
+		}
+		if ( cb.sc_private ) {
+			struct berval *bv = NULL;
+			BerElementBuffer berbuf;
+			BerElement *ber = (BerElement *)&berbuf;
+
+			ber_init_w_nullc( ber, LBER_USE_DER );
+			ber_printf( ber, "{" );
+			txn_put_ctrls( op, ber, cb.sc_private );
+			ber_printf( ber, "}" );
+			ber_flatten( ber, &bv );
+			ber_free_buf( ber );
+			rs->sr_rspdata = bv;
+		}
+		o = p;
+		rc = o->o_bd->bd_info->bi_op_txn(o, SLAP_TXN_COMMIT, &txn );
+		if ( rc ) {
+			rs->sr_text = "transaction commit failed";
+			rc = LDAP_OTHER;
+		}
+	} else {
+		rs->sr_text = "transaction aborted";
+		rc = LDAP_SUCCESS;
+	}
+
+drain:
+	/* drain txn ops list */
+	while (( o = LDAP_STAILQ_FIRST( &c->c_txn_ops )) != NULL ) {
+		LDAP_STAILQ_REMOVE_HEAD( &c->c_txn_ops, o_next );
+		LDAP_STAILQ_NEXT( o, o_next ) = NULL;
+		slap_op_free( o, NULL );
+	}
+
+settled:
+	assert( LDAP_STAILQ_EMPTY(&c->c_txn_ops) );
+	assert( c->c_txn == CONN_TXN_SETTLE );
+	c->c_txn = CONN_TXN_INACTIVE;
+	c->c_txn_backend = NULL;
+
+done:
+	/* release connection lock */
+	ldap_pvt_thread_mutex_unlock( &c->c_mutex );
+
+	return rc;
+}
+
+int txn_preop( Operation *op, SlapReply *rs )
+{
+	/* acquire connection lock */
+	ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
+	if( op->o_conn->c_txn == CONN_TXN_INACTIVE ) {
+		rs->sr_text = "invalid transaction identifier";
+		rs->sr_err = LDAP_TXN_ID_INVALID;
+		goto txnReturn;
+	}
+
+	if( op->o_conn->c_txn_backend == NULL ) {
+		op->o_conn->c_txn_backend = op->o_bd;
+
+	} else if( op->o_conn->c_txn_backend != op->o_bd ) {
+		rs->sr_text = "transaction cannot span multiple database contexts";
+		rs->sr_err = LDAP_AFFECTS_MULTIPLE_DSAS;
+		goto txnReturn;
+	}
+
+	if ( !SLAP_TXNS( op->o_bd )) {
+		rs->sr_text = "backend doesn't support transactions";
+		rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
+		goto txnReturn;
+	}
+
+	/* insert operation into transaction */
+	LDAP_STAILQ_REMOVE( &op->o_conn->c_ops, op, Operation, o_next );
+	LDAP_STAILQ_INSERT_TAIL( &op->o_conn->c_txn_ops, op, o_next );
+
+txnReturn:
+	/* release connection lock */
+	ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
+
+	if ( op->o_tag != LDAP_REQ_EXTENDED )
+		send_ldap_result( op, rs );
+	if ( !rs->sr_err )
+		rs->sr_err = LDAP_TXN_SPECIFY_OKAY;
+	return rs->sr_err;
+}