espintcp: recv() should return 0 when the peer socket is closed

man 2 recv says: RETURN VALUE When a stream socket peer has performed an orderly shutdown, the return value will be 0 (the traditional "end-of-file" return). Currently, this works for blocking reads, but non-blocking reads will return -EAGAIN. This patch overwrites that return value when the peer won't send us any more data. Fixes: e27cca9 ("xfrm: add espintcp (RFC 8229)") Reported-by: Andrew Cagney <[email protected]> Tested-by: Andrew Cagney <[email protected]> Signed-off-by: Sabrina Dubroca <[email protected]> Signed-off-by: Steffen Klassert <[email protected]>
akvadrako · Jul 17, 2020 · e229c87 · e229c87
1 parent ac1321e
commit e229c87
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/net/xfrm/espintcp.c b/net/xfrm/espintcp.c
@@ -109,8 +109,11 @@ static int espintcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 	flags |= nonblock ? MSG_DONTWAIT : 0;
 
 	skb = __skb_recv_datagram(sk, &ctx->ike_queue, flags, &off, &err);
-	if (!skb)
+	if (!skb) {
+		if (err == -EAGAIN && sk->sk_shutdown & RCV_SHUTDOWN)
+			return 0;
 		return err;
+	}
 
 	copied = len;
 	if (copied > skb->len)