For ITS#6157: Catch most invalid cancels/abandons, and honor them before waits

[openldap] / servers / slapd / cancel.c

diff --git a/servers/slapd/cancel.c b/servers/slapd/cancel.c
index 5e65e090db6d4a9e305656a1fc7c14b8455cc2c6..6d27d1756a5b32fe4f6ab674bbcf2687838bc738 100644 (file)
--- 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;