dhcp: fix killing wrong process ID on dhclient release

The prototype of dhclient_start() changed in 30cdd1248 but that
commit didn't update stop() correctly.  Clearly treating a gboolean
as pid_t isn't going to work.  Second, we don't want to watch the
child process on DHCP release because we're just going to kill it
shortly after.

2 files changed, 14 insertions, 9 deletions

diff --git a/src/dhcp-manager/nm-dhcp-client.c b/src/dhcp-manager/nm-dhcp-client.c
index 29584b0662..dc23490a79 100644
--- a/src/dhcp-manager/nm-dhcp-client.c
+++ b/src/dhcp-manager/nm-dhcp-client.c
@@ -214,6 +214,8 @@ nm_dhcp_client_stop_pid (pid_t pid, const char *iface)
 {
 	char *name = iface ? g_strdup_printf ("dhcp-client-%s", iface) : NULL;
 
+	g_return_if_fail (pid > 25);
+
 	nm_utils_kill_child_sync (pid, SIGTERM, LOGD_DHCP, name ? name : "dhcp-client", NULL,
 	                          1000 / 2, 1000 / 20);
 	g_free (name);
@@ -232,9 +234,8 @@ stop (NMDhcpClient *self, gboolean release, const GByteArray *duid)
 		/* Clean up the watch handler since we're explicitly killing the daemon */
 		watch_cleanup (self);
 		nm_dhcp_client_stop_pid (priv->pid, priv->iface);
-		priv->pid = -1;
 	}
-
+	priv->pid = -1;
 	priv->info_only = FALSE;
 }
 
diff --git a/src/dhcp-manager/nm-dhcp-dhclient.c b/src/dhcp-manager/nm-dhcp-dhclient.c
index 41f597f668..f2fe29057d 100644
--- a/src/dhcp-manager/nm-dhcp-dhclient.c
+++ b/src/dhcp-manager/nm-dhcp-dhclient.c
@@ -328,7 +328,8 @@ static gboolean
 dhclient_start (NMDhcpClient *client,
                 const char *mode_opt,
                 const GByteArray *duid,
-                gboolean release)
+                gboolean release,
+                pid_t *out_pid)
 {
 	NMDhcpDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE (client);
 	GPtrArray *argv = NULL;
@@ -461,7 +462,8 @@ dhclient_start (NMDhcpClient *client,
 	                    &dhclient_child_setup, NULL, &pid, &error)) {
 		g_assert (pid > 0);
 		nm_log_info (log_domain, "dhclient started with pid %d", pid);
-		nm_dhcp_client_watch_child (client, pid);
+		if (release == FALSE)
+			nm_dhcp_client_watch_child (client, pid);
 		priv->pid_file = pid_file;
 	} else {
 		nm_log_warn (log_domain, "dhclient failed to start: '%s'", error->message);
@@ -469,6 +471,9 @@ dhclient_start (NMDhcpClient *client,
 		g_free (pid_file);
 	}
 
+	if (out_pid)
+		*out_pid = pid;
+
 	g_ptr_array_free (argv, TRUE);
 	g_free (system_bus_address_env);
 	return pid > 0 ? TRUE : FALSE;
@@ -492,7 +497,7 @@ ip4_start (NMDhcpClient *client,
 		return FALSE;
 	}
 
-	return dhclient_start (client, NULL, NULL, FALSE);
+	return dhclient_start (client, NULL, NULL, FALSE, NULL);
 }
 
 static gboolean
@@ -515,7 +520,7 @@ ip6_start (NMDhcpClient *client,
 		return FALSE;
 	}
 
-	return dhclient_start (client, info_only ? "-S" : "-N", duid, FALSE);
+	return dhclient_start (client, info_only ? "-S" : "-N", duid, FALSE, NULL);
 }
 
 static void
@@ -537,10 +542,9 @@ stop (NMDhcpClient *client, gboolean release, const GByteArray *duid)
 	}
 
 	if (release) {
-		pid_t rpid;
+		pid_t rpid = -1;
 
-		rpid = dhclient_start (client, NULL, duid, TRUE);
-		if (rpid > 0) {
+		if (dhclient_start (client, NULL, duid, TRUE, &rpid)) {
 			/* Wait a few seconds for the release to happen */
 			nm_dhcp_client_stop_pid (rpid, nm_dhcp_client_get_iface (client));
 		}