1 files changed, 67 insertions, 43 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index c765d47986..570e87ad9a 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -72,6 +72,7 @@
 #include <linux/prefetch.h>
 #include <net/dst.h>
 #include <net/tcp.h>
+#include <net/proto_memory.h>
 #include <net/inet_common.h>
 #include <linux/ipsec.h>
 #include <asm/unaligned.h>
@@ -563,19 +564,20 @@ static void tcp_init_buffer_space(struct sock *sk)
 	maxwin = tcp_full_space(sk);
 
 	if (tp->window_clamp >= maxwin) {
-		tp->window_clamp = maxwin;
+		WRITE_ONCE(tp->window_clamp, maxwin);
 
 		if (tcp_app_win && maxwin > 4 * tp->advmss)
-			tp->window_clamp = max(maxwin -
-					       (maxwin >> tcp_app_win),
-					       4 * tp->advmss);
+			WRITE_ONCE(tp->window_clamp,
+				   max(maxwin - (maxwin >> tcp_app_win),
+				       4 * tp->advmss));
 	}
 
 	/* Force reservation of one segment. */
 	if (tcp_app_win &&
 	    tp->window_clamp > 2 * tp->advmss &&
 	    tp->window_clamp + tp->advmss > maxwin)
-		tp->window_clamp = max(2 * tp->advmss, maxwin - tp->advmss);
+		WRITE_ONCE(tp->window_clamp,
+			   max(2 * tp->advmss, maxwin - tp->advmss));
 
 	tp->rcv_ssthresh = min(tp->rcv_ssthresh, tp->window_clamp);
 	tp->snd_cwnd_stamp = tcp_jiffies32;
@@ -773,7 +775,8 @@ void tcp_rcv_space_adjust(struct sock *sk)
 			WRITE_ONCE(sk->sk_rcvbuf, rcvbuf);
 
 			/* Make the window clamp follow along.  */
-			tp->window_clamp = tcp_win_from_space(sk, rcvbuf);
+			WRITE_ONCE(tp->window_clamp,
+				   tcp_win_from_space(sk, rcvbuf));
 		}
 	}
 	tp->rcvq_space.space = copied;
@@ -911,7 +914,7 @@ static void tcp_rtt_estimator(struct sock *sk, long mrtt_us)
 			tp->rtt_seq = tp->snd_nxt;
 			tp->mdev_max_us = tcp_rto_min_us(sk);
 
-			tcp_bpf_rtt(sk);
+			tcp_bpf_rtt(sk, mrtt_us, srtt);
 		}
 	} else {
 		/* no previous measure. */
@@ -921,7 +924,7 @@ static void tcp_rtt_estimator(struct sock *sk, long mrtt_us)
 		tp->mdev_max_us = tp->rttvar_us;
 		tp->rtt_seq = tp->snd_nxt;
 
-		tcp_bpf_rtt(sk);
+		tcp_bpf_rtt(sk, mrtt_us, srtt);
 	}
 	tp->srtt_us = max(1U, srtt);
 }
@@ -3565,7 +3568,7 @@ static void tcp_cong_control(struct sock *sk, u32 ack, u32 acked_sacked,
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 
 	if (icsk->icsk_ca_ops->cong_control) {
-		icsk->icsk_ca_ops->cong_control(sk, rs);
+		icsk->icsk_ca_ops->cong_control(sk, ack, flag, rs);
 		return;
 	}
 
@@ -4466,9 +4469,26 @@ static enum skb_drop_reason tcp_sequence(const struct tcp_sock *tp,
 	return SKB_NOT_DROPPED_YET;
 }
 
+
+void tcp_done_with_error(struct sock *sk, int err)
+{
+	/* This barrier is coupled with smp_rmb() in tcp_poll() */
+	WRITE_ONCE(sk->sk_err, err);
+	smp_wmb();
+
+	tcp_write_queue_purge(sk);
+	tcp_done(sk);
+
+	if (!sock_flag(sk, SOCK_DEAD))
+		sk_error_report(sk);
+}
+EXPORT_SYMBOL(tcp_done_with_error);
+
 /* When we get a reset we do this. */
 void tcp_reset(struct sock *sk, struct sk_buff *skb)
 {
+	int err;
+
 	trace_tcp_receive_reset(sk);
 
 	/* mptcp can't tell us to ignore reset pkts,
@@ -4480,24 +4500,17 @@ void tcp_reset(struct sock *sk, struct sk_buff *skb)
 	/* We want the right error as BSD sees it (and indeed as we do). */
 	switch (sk->sk_state) {
 	case TCP_SYN_SENT:
-		WRITE_ONCE(sk->sk_err, ECONNREFUSED);
+		err = ECONNREFUSED;
 		break;
 	case TCP_CLOSE_WAIT:
-		WRITE_ONCE(sk->sk_err, EPIPE);
+		err = EPIPE;
 		break;
 	case TCP_CLOSE:
 		return;
 	default:
-		WRITE_ONCE(sk->sk_err, ECONNRESET);
+		err = ECONNRESET;
 	}
-	/* This barrier is coupled with smp_rmb() in tcp_poll() */
-	smp_wmb();
-
-	tcp_write_queue_purge(sk);
-	tcp_done(sk);
-
-	if (!sock_flag(sk, SOCK_DEAD))
-		sk_error_report(sk);
+	tcp_done_with_error(sk, err);
 }
 
 /*
@@ -4836,10 +4849,8 @@ static bool tcp_try_coalesce(struct sock *sk,
 	if (!mptcp_skb_can_collapse(to, from))
 		return false;
 
-#ifdef CONFIG_TLS_DEVICE
-	if (from->decrypted != to->decrypted)
+	if (skb_cmp_decrypted(from, to))
 		return false;
-#endif
 
 	if (!skb_try_coalesce(to, from, fragstolen, &delta))
 		return false;
@@ -5207,6 +5218,16 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
 	 */
 	if (TCP_SKB_CB(skb)->seq == tp->rcv_nxt) {
 		if (tcp_receive_window(tp) == 0) {
+			/* Some stacks are known to send bare FIN packets
+			 * in a loop even if we send RWIN 0 in our ACK.
+			 * Accepting this FIN does not hurt memory pressure
+			 * because the FIN flag will simply be merged to the
+			 * receive queue tail skb in most cases.
+			 */
+			if (!skb->len &&
+			    (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN))
+				goto queue_and_out;
+
 			reason = SKB_DROP_REASON_TCP_ZEROWINDOW;
 			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPZEROWINDOWDROP);
 			goto out_of_window;
@@ -5221,7 +5242,7 @@ queue_and_out:
 			inet_csk_schedule_ack(sk);
 			sk->sk_data_ready(sk);
 
-			if (skb_queue_len(&sk->sk_receive_queue)) {
+			if (skb_queue_len(&sk->sk_receive_queue) && skb->len) {
 				reason = SKB_DROP_REASON_PROTO_MEM;
 				NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVQDROP);
 				goto drop;
@@ -5408,9 +5429,7 @@ restart:
 			break;
 
 		memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
-#ifdef CONFIG_TLS_DEVICE
-		nskb->decrypted = skb->decrypted;
-#endif
+		skb_copy_decrypted(nskb, skb);
 		TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start;
 		if (list)
 			__skb_queue_before(list, skb, nskb);
@@ -5440,10 +5459,8 @@ restart:
 				    !mptcp_skb_can_collapse(nskb, skb) ||
 				    (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)))
 					goto end;
-#ifdef CONFIG_TLS_DEVICE
-				if (skb->decrypted != nskb->decrypted)
+				if (skb_cmp_decrypted(skb, nskb))
 					goto end;
-#endif
 			}
 		}
 	}
@@ -6459,7 +6476,8 @@ consume:
 
 		if (!tp->rx_opt.wscale_ok) {
 			tp->rx_opt.snd_wscale = tp->rx_opt.rcv_wscale = 0;
-			tp->window_clamp = min(tp->window_clamp, 65535U);
+			WRITE_ONCE(tp->window_clamp,
+				   min(tp->window_clamp, 65535U));
 		}
 
 		if (tp->rx_opt.saw_tstamp) {
@@ -7034,7 +7052,7 @@ EXPORT_SYMBOL(inet_reqsk_alloc);
 /*
  * Return true if a syncookie should be sent
  */
-static bool tcp_syn_flood_action(const struct sock *sk, const char *proto)
+static bool tcp_syn_flood_action(struct sock *sk, const char *proto)
 {
 	struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
 	const char *msg = "Dropping request";
@@ -7135,7 +7153,6 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
 		     struct sock *sk, struct sk_buff *skb)
 {
 	struct tcp_fastopen_cookie foc = { .len = -1 };
-	__u32 isn = TCP_SKB_CB(skb)->tcp_tw_isn;
 	struct tcp_options_received tmp_opt;
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct net *net = sock_net(sk);
@@ -7145,21 +7162,28 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
 	struct dst_entry *dst;
 	struct flowi fl;
 	u8 syncookies;
+	u32 isn;
 
 #ifdef CONFIG_TCP_AO
 	const struct tcp_ao_hdr *aoh;
 #endif
 
-	syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies);
+	isn = __this_cpu_read(tcp_tw_isn);
+	if (isn) {
+		/* TW buckets are converted to open requests without
+		 * limitations, they conserve resources and peer is
+		 * evidently real one.
+		 */
+		__this_cpu_write(tcp_tw_isn, 0);
+	} else {
+		syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies);
 
-	/* TW buckets are converted to open requests without
-	 * limitations, they conserve resources and peer is
-	 * evidently real one.
-	 */
-	if ((syncookies == 2 || inet_csk_reqsk_queue_is_full(sk)) && !isn) {
-		want_cookie = tcp_syn_flood_action(sk, rsk_ops->slab_name);
-		if (!want_cookie)
-			goto drop;
+		if (syncookies == 2 || inet_csk_reqsk_queue_is_full(sk)) {
+			want_cookie = tcp_syn_flood_action(sk,
+							   rsk_ops->slab_name);
+			if (!want_cookie)
+				goto drop;
+		}
 	}
 
 	if (sk_acceptq_is_full(sk)) {
@@ -7198,7 +7222,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
 	/* Note: tcp_v6_init_req() might override ir_iif for link locals */
 	inet_rsk(req)->ir_iif = inet_request_bound_dev_if(sk, skb);
 
-	dst = af_ops->route_req(sk, skb, &fl, req);
+	dst = af_ops->route_req(sk, skb, &fl, req, isn);
 	if (!dst)
 		goto drop_and_free;