[PATCH iproute2 11/11] ss: report a failed SCTP or MPTCP dump

[Stephen Hemminger <stephen@networkplumber.org>]

sctp_show() and mptcp_show() discarded the return of
inet_show_netlink(), unlike every other family, so ss -S and ss -M
printed only a header and exited 0 when the kernel could not dump.

Neither protocol is dumped unless asked for, and sock_diag_error()
already reports a missing module as lack of support, so this does
not add noise to a default run.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 misc/ss.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/misc/ss.c b/misc/ss.c
index 7c47d377..f4160f59 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -4105,7 +4105,8 @@ static int mptcp_show(struct filter *f)
 	if (!filter_af_get(f, AF_INET) && !filter_af_get(f, AF_INET6))
 		return 0;
 
-	inet_show_netlink(f, NULL, IPPROTO_MPTCP);
+	if (inet_show_netlink(f, NULL, IPPROTO_MPTCP))
+		return sock_diag_error("MPTCP");
 	return 0;
 }
 
@@ -4114,7 +4115,8 @@ static int sctp_show(struct filter *f)
 	if (!filter_af_get(f, AF_INET) && !filter_af_get(f, AF_INET6))
 		return 0;
 
-	inet_show_netlink(f, NULL, IPPROTO_SCTP);
+	if (inet_show_netlink(f, NULL, IPPROTO_SCTP))
+		return sock_diag_error("SCTP");
 	return 0;
 }
 
-- 
2.53.0