Merge branch 'tcp-disable-header-prediction-for-md5'

Kuniyuki Iwashima says:

====================
tcp: Disable header prediction for MD5.

The 1st patch disable header prediction for MD5 flow and the 2nd
patch updates the stale comment in tcp_parse_options().
====================

Link: https://lore.kernel.org/r/20230803224552.69398-1-kuniyu@amazon.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/ipv4/tcp_input.c

@@ -4126,9 +4126,8 @@ void tcp_parse_options(const struct net *net,
 				break;
 #ifdef CONFIG_TCP_MD5SIG
 			case TCPOPT_MD5SIG:
-				/*
-				 * The MD5 Hash has already been
-				 * checked (see tcp_v{4,6}_do_rcv()).
+				/* The MD5 Hash has already been
+				 * checked (see tcp_v{4,6}_rcv()).
 				 */
 				break;
 #endif

net/ipv4/tcp_minisocks.c

@@ -570,8 +570,6 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
 	newtp->tsoffset = treq->ts_off;
 #ifdef CONFIG_TCP_MD5SIG
 	newtp->md5sig_info = NULL;	/*XXX*/
-	if (treq->af_specific->req_md5_lookup(sk, req_to_sk(req)))
-		newtp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED;
 #endif
 	if (skb->len >= TCP_MSS_DEFAULT + newtp->tcp_header_len)
 		newicsk->icsk_ack.last_seg_size = skb->len - newtp->tcp_header_len;

net/ipv4/tcp_output.c

@@ -3741,11 +3741,6 @@ static void tcp_connect_init(struct sock *sk)
 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_timestamps))
 		tp->tcp_header_len += TCPOLEN_TSTAMP_ALIGNED;
 
-#ifdef CONFIG_TCP_MD5SIG
-	if (tp->af_specific->md5_lookup(sk, sk))
-		tp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED;
-#endif
-
 	/* If user gave his TCP_MAXSEG, record it to clamp */
 	if (tp->rx_opt.user_mss)
 		tp->rx_opt.mss_clamp = tp->rx_opt.user_mss;