From: Martin Schwenke <martin@meltin.net>
Date: Mon, 13 Jan 2020 10:04:54 +0000 (+1100)
Subject: ctdb-daemon: Shut down if interactive and stdin is closed
X-Git-Tag: ldb-2.1.1~235
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cf460bd9c4ae1e0de871a6c4980a2c365e82550a;p=thirdparty%2Fsamba.git

ctdb-daemon: Shut down if interactive and stdin is closed

This allows a test environment to simply close its end of a pipe to
cleanly shutdown ctdbd.  Like in smbd, this is only done if stdin is a
pipe or a socket.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>
---

diff --git a/ctdb/server/ctdb_daemon.c b/ctdb/server/ctdb_daemon.c
index cc688b07e9c..c4ab2dbc3d3 100644
--- a/ctdb/server/ctdb_daemon.c
+++ b/ctdb/server/ctdb_daemon.c
@@ -1389,6 +1389,56 @@ static void ctdb_set_my_pnn(struct ctdb_context *ctdb)
 	D_NOTICE("PNN is %u\n", ctdb->pnn);
 }
 
+static void stdin_handler(struct tevent_context *ev,
+			  struct tevent_fd *fde,
+			  uint16_t flags,
+			  void *private_data)
+{
+	struct ctdb_context *ctdb = talloc_get_type_abort(
+		private_data, struct ctdb_context);
+	ssize_t nread;
+	char c;
+
+	nread = read(STDIN_FILENO, &c, 1);
+	if (nread != 1) {
+		D_ERR("stdin closed, exiting\n");
+		talloc_free(fde);
+		ctdb_shutdown_sequence(ctdb, EPIPE);
+	}
+}
+
+static int setup_stdin_handler(struct ctdb_context *ctdb)
+{
+	struct tevent_fd *fde;
+	struct stat st;
+	int ret;
+
+	ret = fstat(STDIN_FILENO, &st);
+	if (ret != 0) {
+		/* Problem with stdin, ignore... */
+		DBG_INFO("Can't fstat() stdin\n");
+		return 0;
+	}
+
+	if (!S_ISFIFO(st.st_mode)) {
+		DBG_INFO("Not a pipe...\n");
+		return 0;
+	}
+
+	fde = tevent_add_fd(ctdb->ev,
+			    ctdb,
+			    STDIN_FILENO,
+			    TEVENT_FD_READ,
+			    stdin_handler,
+			    ctdb);
+	if (fde == NULL) {
+		return ENOMEM;
+	}
+
+	DBG_INFO("Set up stdin handler\n");
+	return 0;
+}
+
 /*
   start the protocol going as a daemon
 */
@@ -1448,6 +1498,15 @@ int ctdb_start_daemon(struct ctdb_context *ctdb, bool do_fork)
 		ctdb_set_child_logging(ctdb);
 	}
 
+	/* Exit if stdin is closed */
+	if (!do_fork) {
+		ret = setup_stdin_handler(ctdb);
+		if (ret != 0) {
+			DBG_ERR("Failed to setup stdin handler\n");
+			exit(1);
+		}
+	}
+
 	TALLOC_FREE(ctdb->srv);
 	if (srvid_init(ctdb, &ctdb->srv) != 0) {
 		DEBUG(DEBUG_CRIT,("Failed to setup message srvid context\n"));