From bf409dbab5f5910de6c2691f978bb8644532728a Mon Sep 17 00:00:00 2001

From: Rob Crittenden <rcritten@redhat.com>

Date: Mon, 18 May 2020 15:01:02 -0400

Subject: [PATCH] Adapt to the new behavior of disconnect in dbus-broker

The dbus server was replaced in Fedora-29 to use dbus-broker.

This server does not allow reconnects on a disconnect. certmonger

was crashing as a result.

The only way to directly pass a message between the dbus queue and

the main tevent handle is via a signal. So when a disconnect is

detected send a SIGTERM to getpid() in order to force a graceful

shutdown.

https://bugzilla.redhat.com/show_bug.cgi?id=1687698

---

 src/tdbus.c | 61 ++++++++++-------------------------------------------

 1 file changed, 11 insertions(+), 50 deletions(-)

diff --git a/src/tdbus.c b/src/tdbus.c

index a81b534..402022e 100644

--- a/src/tdbus.c

+++ b/src/tdbus.c

@@ -22,6 +22,7 @@

 #include <stdlib.h>

 #include <string.h>

 #include <unistd.h>

+#include <signal.h>

 #include <talloc.h>

 #include <tevent.h>

@@ -522,60 +523,24 @@ cm_tdbus_timeout_cleanup(void *data)

 }

 static void

-cm_tdbus_reconnect(struct tevent_context *ec, struct tevent_timer *timer,

+cm_tdbus_disconnected(struct tevent_context *ec, struct tevent_timer *timer,

 		   struct timeval current_time, void *pvt)

 {

-	const char *bus_desc;

 	struct tdbus_connection *tdb;

-	struct timeval later;

-	dbus_bool_t exit_on_disconnect = TRUE;

+	pid_t pid;

 	tdb = pvt;

 	talloc_free(timer);

 	if ((tdb->conn == NULL) ||

 	    !dbus_connection_get_is_connected(tdb->conn)) {

-		/* Close the current connection and open a new one. */

+		/* Close the current connection and exit. */

 		if (tdb->conn != NULL) {

 			dbus_connection_unref(tdb->conn);

 			tdb->conn = NULL;

 		}

-		bus_desc = NULL;

-		switch (tdb->conn_type) {

-		case cm_tdbus_system:

-			cm_log(1, "Attempting to reconnect to system bus.\n");

-			tdb->conn = dbus_bus_get(DBUS_BUS_SYSTEM, NULL);

-			cm_set_conn_ptr(tdb->data, tdb->conn);

-			/* Don't exit if we get disconnected. */

-			exit_on_disconnect = FALSE;

-			bus_desc = "system";

-			break;

-		case cm_tdbus_session:

-			cm_log(1, "Attempting to reconnect to session bus.\n");

-			tdb->conn = dbus_bus_get(DBUS_BUS_SESSION, NULL);

-			cm_set_conn_ptr(tdb->data, tdb->conn);

-			/* Exit if we get disconnected. */

-			exit_on_disconnect = TRUE;

-			bus_desc = "session";

-			break;

-		case cm_tdbus_private:

-			abort();

-			break;

-		}

-		if ((tdb->conn != NULL) &&

-		    dbus_connection_get_is_connected(tdb->conn)) {

-			/* We're reconnected; reset our handlers. */

-			cm_log(1, "Reconnected to %s bus.\n", bus_desc);

-			dbus_connection_set_exit_on_disconnect(tdb->conn,

-							       exit_on_disconnect);

-			cm_tdbus_setup_public_connection(tdb, tdb->conn,

-							 bus_desc, NULL);

-		} else {

-			/* Try reconnecting again later. */

-			later = tevent_timeval_current_ofs(CM_DBUS_RECONNECT_TIMEOUT, 0),

-			tevent_add_timer(ec, tdb, later,

-					 cm_tdbus_reconnect,

-					 tdb);

-		}

+		pid = getpid();

+		cm_log(0, "Disconnected from dbus, exiting with SIGTERM.\n");

+		kill(pid, SIGTERM);

 	}

 }

@@ -585,12 +550,12 @@ cm_tdbus_filter(DBusConnection *conn, DBusMessage *dmessage, void *data)

 	struct tdbus_connection *tdb = data;

 	const char *destination, *unique_name, *path, *interface, *member;

-	/* If we're disconnected, queue a reconnect. */

+	/* If we're disconnected, queue an exit. */

 	if ((tdb->conn_type != cm_tdbus_private) &&

 	    !dbus_connection_get_is_connected(conn)) {

 		tevent_add_timer(talloc_parent(tdb), tdb,

 				 tevent_timeval_current(),

-				 cm_tdbus_reconnect,

+				 cm_tdbus_disconnected,

 				 tdb);

 		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

 	}

@@ -745,7 +710,6 @@ cm_tdbus_setup_public(struct tevent_context *ec, enum cm_tdbus_type bus_type,

 	DBusError err;

 	const char *bus_desc;

 	struct tdbus_connection *tdb;

-	dbus_bool_t exit_on_disconnect;

 	/* Build our own context. */

 	tdb = talloc_ptrtype(ec, tdb);

@@ -764,15 +728,11 @@ cm_tdbus_setup_public(struct tevent_context *ec, enum cm_tdbus_type bus_type,

 	case cm_tdbus_system:

 		conn = dbus_bus_get(DBUS_BUS_SYSTEM, error);

 		cm_set_conn_ptr(data, conn);

-		/* Don't exit if we get disconnected. */

-		exit_on_disconnect = FALSE;

 		bus_desc = "system";

 		break;

 	case cm_tdbus_session:

 		conn = dbus_bus_get(DBUS_BUS_SESSION, error);

 		cm_set_conn_ptr(data, conn);

-		/* Exit if we get disconnected. */

-		exit_on_disconnect = TRUE;

 		bus_desc = "session";

 		break;

 	case cm_tdbus_private:

@@ -784,7 +744,8 @@ cm_tdbus_setup_public(struct tevent_context *ec, enum cm_tdbus_type bus_type,

 		talloc_free(tdb);

 		return -1;

 	}

-	dbus_connection_set_exit_on_disconnect(conn, exit_on_disconnect);

+	/* Exit on disconnect is handled in cm_tdbus_disconnected(). */

+	dbus_connection_set_exit_on_disconnect(conn, FALSE);

 	tdb->conn = conn;

 	tdb->conn_type = bus_type;

 	tdb->data = data;

-- 

2.21.1