From: Stefan Metzmacher <metze@samba.org>
Date: Fri, 23 Mar 2018 13:48:46 +0000 (+0100)
Subject: s3:messages: allow messaging_{dgm,ctdb}_register_tevent_context() to use wrapper... 
X-Git-Tag: tdb-1.3.16~51
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=660cf86639753edaa7a7a21a5b5ae207ae7d4260;p=thirdparty%2Fsamba.git

s3:messages: allow messaging_{dgm,ctdb}_register_tevent_context() to use wrapper tevent_context

This is only allowed if the raw tevent context is already registered.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
---

diff --git a/source3/lib/messages_ctdb.c b/source3/lib/messages_ctdb.c
index a1aeb37af19..11fe72661cc 100644
--- a/source3/lib/messages_ctdb.c
+++ b/source3/lib/messages_ctdb.c
@@ -209,14 +209,6 @@ struct messaging_ctdb_fde *messaging_ctdb_register_tevent_context(
 		return NULL;
 	}
 
-	if (tevent_context_is_wrapper(ev)) {
-		/*
-		 * This is really a programmer error!
-		 */
-		DBG_ERR("Should not be used with a wrapper tevent context\n");
-		return NULL;
-	}
-
 	fde = talloc(mem_ctx, struct messaging_ctdb_fde);
 	if (fde == NULL) {
 		return NULL;
@@ -234,7 +226,24 @@ struct messaging_ctdb_fde *messaging_ctdb_register_tevent_context(
 			 */
 			continue;
 		}
-		if (fde_ev->ev == ev) {
+
+		/*
+		 * We can only have one tevent_fd
+		 * per low level tevent_context.
+		 *
+		 * This means any wrapper tevent_context
+		 * needs to share the structure with
+		 * the main tevent_context and/or
+		 * any sibling wrapper tevent_context.
+		 *
+		 * This means we need to use tevent_context_same_loop()
+		 * instead of just (fde_ev->ev == ev).
+		 *
+		 * Note: the tevent_context_is_wrapper() check below
+		 * makes sure that fde_ev->ev is always a raw
+		 * tevent context.
+		 */
+		if (tevent_context_same_loop(fde_ev->ev, ev)) {
 			break;
 		}
 	}
@@ -242,6 +251,17 @@ struct messaging_ctdb_fde *messaging_ctdb_register_tevent_context(
 	if (fde_ev == NULL) {
 		int sock = ctdbd_conn_get_fd(ctx->conn);
 
+		if (tevent_context_is_wrapper(ev)) {
+			/*
+			 * This is really a programmer error!
+			 *
+			 * The main/raw tevent context should
+			 * have been registered first!
+			 */
+			DBG_ERR("Should not be used with a wrapper tevent context\n");
+			return NULL;
+		}
+
 		fde_ev = talloc(fde, struct messaging_ctdb_fde_ev);
 		if (fde_ev == NULL) {
 			return NULL;
diff --git a/source3/lib/messages_dgm.c b/source3/lib/messages_dgm.c
index 1c76615093c..0ad8f46e09f 100644
--- a/source3/lib/messages_dgm.c
+++ b/source3/lib/messages_dgm.c
@@ -1679,14 +1679,6 @@ struct messaging_dgm_fde *messaging_dgm_register_tevent_context(
 		return NULL;
 	}
 
-	if (tevent_context_is_wrapper(ev)) {
-		/*
-		 * This is really a programmer error!
-		 */
-		DBG_ERR("Should not be used with a wrapper tevent context\n");
-		return NULL;
-	}
-
 	fde = talloc(mem_ctx, struct messaging_dgm_fde);
 	if (fde == NULL) {
 		return NULL;
@@ -1704,12 +1696,40 @@ struct messaging_dgm_fde *messaging_dgm_register_tevent_context(
 			 */
 			continue;
 		}
-		if (fde_ev->ev == ev) {
+
+		/*
+		 * We can only have one tevent_fd
+		 * per low level tevent_context.
+		 *
+		 * This means any wrapper tevent_context
+		 * needs to share the structure with
+		 * the main tevent_context and/or
+		 * any sibling wrapper tevent_context.
+		 *
+		 * This means we need to use tevent_context_same_loop()
+		 * instead of just (fde_ev->ev == ev).
+		 *
+		 * Note: the tevent_context_is_wrapper() check below
+		 * makes sure that fde_ev->ev is always a raw
+		 * tevent context.
+		 */
+		if (tevent_context_same_loop(fde_ev->ev, ev)) {
 			break;
 		}
 	}
 
 	if (fde_ev == NULL) {
+		if (tevent_context_is_wrapper(ev)) {
+			/*
+			 * This is really a programmer error!
+			 *
+			 * The main/raw tevent context should
+			 * have been registered first!
+			 */
+			DBG_ERR("Should not be used with a wrapper tevent context\n");
+			return NULL;
+		}
+
 		fde_ev = talloc(fde, struct messaging_dgm_fde_ev);
 		if (fde_ev == NULL) {
 			return NULL;