selftests: mptcp: explicitly tests aggregate counters

Update the existing sockopt test-case to do some basic checks
on the newly added counters.

Link: #385
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>

tools/testing/selftests/net/mptcp/mptcp_sockopt.c

@@ -51,6 +51,11 @@ struct mptcp_info {
 	__u8	mptcpi_local_addr_used;
 	__u8	mptcpi_local_addr_max;
 	__u8	mptcpi_csum_enabled;
+	__u32	mptcpi_retransmits;
+	__u64	mptcpi_bytes_retrans;
+	__u64	mptcpi_bytes_sent;
+	__u64	mptcpi_bytes_received;
+	__u64	mptcpi_bytes_acked;
 };
 
 struct mptcp_subflow_data {
@@ -83,8 +88,10 @@ struct mptcp_subflow_addrs {
 
 struct so_state {
 	struct mptcp_info mi;
+	struct mptcp_info last_sample;
 	uint64_t mptcpi_rcv_delta;
 	uint64_t tcpi_rcv_delta;
+	bool pkt_stats_avail;
 };
 
 #ifndef MIN
@@ -322,8 +329,9 @@ static void do_getsockopt_mptcp_info(struct so_state *s, int fd, size_t w)
 	if (ret < 0)
 		die_perror("getsockopt MPTCP_INFO");
 
-	assert(olen == sizeof(i));
+	s->pkt_stats_avail = olen >= sizeof(i);
 
+	s->last_sample = i;
 	if (s->mi.mptcpi_write_seq == 0)
 		s->mi = i;
 
@@ -562,6 +570,23 @@ static void process_one_client(int fd, int pipefd)
 	do_getsockopts(&s, fd, ret, ret2);
 	if (s.mptcpi_rcv_delta != (uint64_t)ret + 1)
 		xerror("mptcpi_rcv_delta %" PRIu64 ", expect %" PRIu64, s.mptcpi_rcv_delta, ret + 1, s.mptcpi_rcv_delta - ret);
+
+	/* be nice when running on top of older kernel */
+	if (s.pkt_stats_avail) {
+		if (s.last_sample.mptcpi_bytes_sent != ret2)
+			xerror("mptcpi_bytes_sent %" PRIu64 ", expect %" PRIu64,
+			       s.last_sample.mptcpi_bytes_sent, ret2,
+			       s.last_sample.mptcpi_bytes_sent - ret2);
+		if (s.last_sample.mptcpi_bytes_received != ret)
+			xerror("mptcpi_bytes_received %" PRIu64 ", expect %" PRIu64,
+			       s.last_sample.mptcpi_bytes_received, ret,
+			       s.last_sample.mptcpi_bytes_received - ret);
+		if (s.last_sample.mptcpi_bytes_acked != ret)
+			xerror("mptcpi_bytes_acked %" PRIu64 ", expect %" PRIu64,
+			       s.last_sample.mptcpi_bytes_acked, ret2,
+			       s.last_sample.mptcpi_bytes_acked - ret2);
+	}
+
 	close(fd);
 }