From 96f4c723a916cf20850679e1cce8bb2ceb601041 Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Thu, 4 Jun 2009 21:16:38 +0000
Subject: [PATCH] For ITS#6157: Catch most invalid cancels/abandons, and honor
 them before waits

---
 servers/slapd/abandon.c | 11 +++++++++++
 servers/slapd/bconfig.c | 18 ++++++++++++++++--
 servers/slapd/cancel.c  | 37 ++++++++++++++++++++++++++++++-------
 3 files changed, 57 insertions(+), 9 deletions(-)

diff --git a/servers/slapd/abandon.c b/servers/slapd/abandon.c
index 8e08707756..8b0156902c 100644
--- a/servers/slapd/abandon.c
+++ b/servers/slapd/abandon.c
@@ -96,6 +96,17 @@ do_abandon( Operation *op, SlapReply *rs )
 				break;
 			}
 		}
+
+	} else if ( o->o_tag == LDAP_REQ_BIND
+			|| o->o_tag == LDAP_REQ_UNBIND
+			|| o->o_tag == LDAP_REQ_ABANDON ) {
+		msg = "cannot be abandoned";
+
+#if 0 /* Would break o_abandon used as "suppress response" flag, ITS#6138 */
+	} else if ( o->o_abandon ) {
+		msg = "already being abandoned";
+#endif
+
 	} else {
 		msg = "found";
 		/* Set the o_abandon flag in the to-be-abandoned operation.
diff --git a/servers/slapd/bconfig.c b/servers/slapd/bconfig.c
index b259178efe..a3fd9aa19f 100644
--- a/servers/slapd/bconfig.c
+++ b/servers/slapd/bconfig.c
@@ -4783,6 +4783,10 @@ config_back_add( Operation *op, SlapReply *rs )
 		}
 	}
 
+	if ( op->o_abandon ) {
+		rs->sr_err = SLAPD_ABANDON;
+		goto out;
+	}
 	ldap_pvt_thread_pool_pause( &connection_pool );
 
 	/* Strategy:
@@ -5223,8 +5227,13 @@ config_back_modify( Operation *op, SlapReply *rs )
 
 	slap_mods_opattrs( op, &op->orm_modlist, 1 );
 
-	if ( do_pause )
+	if ( do_pause ) {
+		if ( op->o_abandon ) {
+			rs->sr_err = SLAPD_ABANDON;
+			goto out;
+		}
 		ldap_pvt_thread_pool_pause( &connection_pool );
+	}
 
 	/* Strategy:
 	 * 1) perform the Modify on the cached Entry.
@@ -5388,6 +5397,10 @@ config_back_modrdn( Operation *op, SlapReply *rs )
 		goto out;
 	}
 
+	if ( op->o_abandon ) {
+		rs->sr_err = SLAPD_ABANDON;
+		goto out;
+	}
 	ldap_pvt_thread_pool_pause( &connection_pool );
 
 	if ( ce->ce_type == Cft_Schema ) {
@@ -5477,6 +5490,8 @@ config_back_delete( Operation *op, SlapReply *rs )
 		rs->sr_err = LDAP_NO_SUCH_OBJECT;
 	} else if ( ce->ce_kids ) {
 		rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
+	} else if ( op->o_abandon ) {
+		rs->sr_err = SLAPD_ABANDON;
 	} else if ( ce->ce_type == Cft_Overlay || ce->ce_type == Cft_Database ){
 		char *iptr;
 		int count, ixold;
@@ -6655,4 +6670,3 @@ config_back_initialize( BackendInfo *bi )
 
 	return 0;
 }
-
diff --git a/servers/slapd/cancel.c b/servers/slapd/cancel.c
index 5e65e090db..6d27d1756a 100644
--- a/servers/slapd/cancel.c
+++ b/servers/slapd/cancel.c
@@ -66,16 +66,25 @@ int cancel_extop( Operation *op, SlapReply *rs )
 
 	ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
 
+	if ( op->o_abandon ) {
+		/* FIXME: Should instead reject the cancel/abandon of this op, but
+		 * it seems unsafe to reset op->o_abandon once it is set. ITS#6138.
+		 */
+		rc = LDAP_OPERATIONS_ERROR;
+		rs->sr_text = "tried to abandon or cancel this operation";
+		goto out;
+	}
+
 	LDAP_STAILQ_FOREACH( o, &op->o_conn->c_pending_ops, o_next ) {
 		if ( o->o_msgid == opid ) {
-			ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
 			/* TODO: We could instead remove the cancelled operation
 			 * from c_pending_ops like Abandon does, and send its
 			 * response here.  Not if it is pending because of a
 			 * congested connection though.
 			 */
+			rc = LDAP_CANNOT_CANCEL;
 			rs->sr_text = "too busy for Cancel, try Abandon instead";
-			return LDAP_CANNOT_CANCEL;
+			goto out;
 		}
 	}
 
@@ -88,15 +97,31 @@ int cancel_extop( Operation *op, SlapReply *rs )
 	if ( o == NULL ) {
 	 	rc = LDAP_NO_SUCH_OPERATION;
 		rs->sr_text = "message ID not found";
+
+	} else if ( o->o_tag == LDAP_REQ_BIND
+			|| o->o_tag == LDAP_REQ_UNBIND
+			|| o->o_tag == LDAP_REQ_ABANDON ) {
+		rc = LDAP_CANNOT_CANCEL;
+
 	} else if ( o->o_cancel != SLAP_CANCEL_NONE ) {
-		rc = LDAP_PROTOCOL_ERROR;
+		rc = LDAP_OPERATIONS_ERROR;
 		rs->sr_text = "message ID already being cancelled";
+
+#if 0
+	} else if ( o->o_abandon ) {
+		/* TODO: Would this break something when
+		 * o_abandon="suppress response"? (ITS#6138)
+		 */
+		rc = LDAP_TOO_LATE;
+#endif
+
 	} else {
 		rc = LDAP_SUCCESS;
 		o->o_cancel = SLAP_CANCEL_REQ;
 		o->o_abandon = 1;
 	}
 
+ out:
 	ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
 
 	if ( rc == LDAP_SUCCESS ) {
@@ -109,14 +134,12 @@ int cancel_extop( Operation *op, SlapReply *rs )
 			}
 		}
 
-		while ( o->o_cancel == SLAP_CANCEL_REQ ) {
+		while ( (rc = o->o_cancel) == SLAP_CANCEL_REQ ) {
 			ldap_pvt_thread_yield();
 		}
 
-		if ( o->o_cancel == SLAP_CANCEL_ACK ) {
+		if ( rc == SLAP_CANCEL_ACK ) {
 			rc = LDAP_SUCCESS;
-		} else {
-			rc = o->o_cancel;
 		}
 
 		o->o_cancel = SLAP_CANCEL_DONE;
-- 
2.39.5