From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Date: Wed, 5 Feb 2020 05:58:34 +0100
Subject: samples: bpf: Allow for -ENETDOWN in xdpsock
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Patch-mainline: v5.6-rc1
Git-commit: 8ed47e140867a6e7d56170f325c8d4fdee6d6b66
References: bsc#1155518

ndo_xsk_wakeup() can return -ENETDOWN and there's no particular reason
to bail the whole application out on that case. Let's check in kick_tx()
whether errno was set to mentioned value and basically allow application
to further process frames.

Fixes: 248c7f9c0e21 ("samples/bpf: convert xdpsock to use libbpf for AF_XDP access")
Reported-by: Cameron Elliott <cameron@cameronelliott.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/20200205045834.56795-4-maciej.fijalkowski@intel.com
Acked-by: Gary Lin <glin@suse.com>
---
 samples/bpf/xdpsock_user.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -454,7 +454,8 @@ static void kick_tx(struct xsk_socket_in
 	int ret;
 
 	ret = sendto(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0);
-	if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN || errno == EBUSY)
+	if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN ||
+	    errno == EBUSY || errno == ENETDOWN)
 		return;
 	exit_with_error(errno);
 }