[PATCH iproute2] bridge: fdb: add an error print for unknown command

[Amit Cohen <amcohen@nvidia.com>]

Commit 6e1ca489c5a2 ("bridge: fdb: add new flush command") added support
for "bridge fdb flush" command. This commit did not handle unsupported
keywords, they are just ignored.

Add an error print to notify the user when a keyword which is not supported
is used. The kernel will be extended to support flush with VXLAN device,
so new attributes will be supported (e.g., vni, port). When iproute-2 does
not warn for unsupported keyword, user might think that the flush command
works, although the iproute-2 version is too old and it does not send VXLAN
attributes to the kernel.

Fixes: 6e1ca489c5a2 ("bridge: fdb: add new flush command")
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
---
 bridge/fdb.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/bridge/fdb.c b/bridge/fdb.c
index ae8f7b46..d7ef26fd 100644
--- a/bridge/fdb.c
+++ b/bridge/fdb.c
@@ -761,9 +761,13 @@ static int fdb_flush(int argc, char **argv)
 				duparg2("vlan", *argv);
 			NEXT_ARG();
 			vid = atoi(*argv);
+		} else if (strcmp(*argv, "help") == 0) {
+			NEXT_ARG();
 		} else {
-			if (strcmp(*argv, "help") == 0)
-				NEXT_ARG();
+			fprintf(stderr, "bridge fdb: unknown command \"%s\"?\n",
+				*argv);
+			usage();
+			return -1;
 		}
 		argc--; argv++;
 	}
-- 
2.40.1