[PATCH 1/2] batctl: interface: report rtnl query failures

[Sven Eckelmann <sven@narfation.org>]

print_interfaces() ignores the query_rtnl_link() result. When the rtnl
socket setup or the dump request fails, batctl interface prints nothing and
exits with EXIT_SUCCESS. This is indistinguishable from a
meshif without any slave interfaces.

Check the result and fail with an error message instead.

Fixes: 60e519bfeaa3 ("batctl: Use rtnl to query list of softif devices")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
 interface.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/interface.c b/interface.c
index 7d3897c..c734eda 100644
--- a/interface.c
+++ b/interface.c
@@ -164,11 +164,17 @@ static int print_interfaces(struct state *state)
 	if (ret < 0)
 		return EXIT_FAILURE;
 
-	query_rtnl_link(state->mesh_ifindex, print_interfaces_rtnl_parse,
-			state);
+	ret = query_rtnl_link(state->mesh_ifindex, print_interfaces_rtnl_parse,
+			      state);
 
 	netlink_destroy(state);
 
+	if (ret < 0) {
+		fprintf(stderr, "Error - could not query interfaces: %s\n",
+			strerror(-ret));
+		return EXIT_FAILURE;
+	}
+
 	return EXIT_SUCCESS;
 }
 

-- 
2.47.3