mptcp: tune re-injections for csum enabled mode

If the MPTCP-level checksum is enabled, on re-injections we must spool a complete DSS, or the receive side will not be able to compute the csum and process any data. Reviewed-by: Mat Martineau <[email protected]> Signed-off-by: Paolo Abeni <[email protected]>
multipath-tcp · May 6, 2021 · 7929c26 · 7929c26
1 parent ac7a5e6
commit 7929c26
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
@@ -2333,8 +2333,8 @@ static void __mptcp_retrans(struct sock *sk)
 
 	/* limit retransmission to the bytes already sent on some subflows */
 	info.sent = 0;
-	info.limit = dfrag->already_sent;
-	while (info.sent < dfrag->already_sent) {
+	info.limit = READ_ONCE(msk->csum_enabled) ? dfrag->data_len : dfrag->already_sent;
+	while (info.sent < info.limit) {
 		if (!mptcp_alloc_tx_skb(sk, ssk))
 			break;
 
@@ -2346,9 +2346,11 @@ static void __mptcp_retrans(struct sock *sk)
 		copied += ret;
 		info.sent += ret;
 	}
-	if (copied)
+	if (copied) {
+		dfrag->already_sent = max(dfrag->already_sent, info.sent);
 		tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
 			 info.size_goal);
+	}
 
 	mptcp_set_timeout(sk, ssk);
 	release_sock(ssk);