Merge tag 'net-next-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core
  ----

   - Support TCPv6 segmentation offload with super-segments larger than
     64k bytes using the IPv6 Jumbogram extension header (AKA BIG TCP).

   - Generalize skb freeing deferral to per-cpu lists, instead of
     per-socket lists.

   - Add a netdev statistic for packets dropped due to L2 address
     mismatch (rx_otherhost_dropped).

   - Continue work annotating skb drop reasons.

   - Accept alternative netdev names (ALT_IFNAME) in more netlink
     requests.

   - Add VLAN support for AF_PACKET SOCK_RAW GSO.

   - Allow receiving skb mark from the socket as a cmsg.

   - Enable memcg accounting for veth queues, sysctl tables and IPv6.

  BPF
  ---

   - Add libbpf support for User Statically-Defined Tracing (USDTs).

   - Speed up symbol resolution for kprobes multi-link attachments.

   - Support storing typed pointers to referenced and unreferenced
     objects in BPF maps.

   - Add support for BPF link iterator.

   - Introduce access to remote CPU map elements in BPF per-cpu map.

   - Allow middle-of-the-road settings for the
     kernel.unprivileged_bpf_disabled sysctl.

   - Implement basic types of dynamic pointers e.g. to allow for
     dynamically sized ringbuf reservations without extra memory copies.

  Protocols
  ---------

   - Retire port only listening_hash table, add a second bind table
     hashed by port and address. Avoid linear list walk when binding to
     very popular ports (e.g. 443).

   - Add bridge FDB bulk flush filtering support allowing user space to
     remove all FDB entries matching a condition.

   - Introduce accept_unsolicited_na sysctl for IPv6 to implement
     router-side changes for RFC9131.

   - Support for MPTCP path manager in user space.

   - Add MPTCP support for fallback to regular TCP for connections that
     have never connected additional subflows or transmitted
     out-of-sequence data (partial support for RFC8684 fallback).

   - Avoid races in MPTCP-level window tracking, stabilize and improve
     throughput.

   - Support lockless operation of GRE tunnels with seq numbers enabled.

   - WiFi support for host based BSS color collision detection.

   - Add support for SO_TXTIME/SCM_TXTIME on CAN sockets.

   - Support transmission w/o flow control in CAN ISOTP (ISO 15765-2).

   - Support zero-copy Tx with TLS 1.2 crypto offload (sendfile).

   - Allow matching on the number of VLAN tags via tc-flower.

   - Add tracepoint for tcp_set_ca_state().

  Driver API
  ----------

   - Improve error reporting from classifier and action offload.

   - Add support for listing line cards in switches (devlink).

   - Add helpers for reporting page pool statistics with ethtool -S.

   - Add support for reading clock cycles when using PTP virtual clocks,
     instead of having the driver convert to time before reporting. This
     makes it possible to report time from different vclocks.

   - Support configuring low-latency Tx descriptor push via ethtool.

   - Separate Clause 22 and Clause 45 MDIO accesses more explicitly.

  New hardware / drivers
  ----------------------

   - Ethernet:
      - Marvell's Octeon NIC PCI Endpoint support (octeon_ep)
      - Sunplus SP7021 SoC (sp7021_emac)
      - Add support for Renesas RZ/V2M (in ravb)
      - Add support for MediaTek mt7986 switches (in mtk_eth_soc)

   - Ethernet PHYs:
      - ADIN1100 industrial PHYs (w/ 10BASE-T1L and SQI reporting)
      - TI DP83TD510 PHY
      - Microchip LAN8742/LAN88xx PHYs

   - WiFi:
      - Driver for pureLiFi X, XL, XC devices (plfxlc)
      - Driver for Silicon Labs devices (wfx)
      - Support for WCN6750 (in ath11k)
      - Support Realtek 8852ce devices (in rtw89)

   - Mobile:
      - MediaTek T700 modems (Intel 5G 5000 M.2 cards)

   - CAN:
      - ctucanfd: add support for CTU CAN FD open-source IP core from
        Czech Technical University in Prague

  Drivers
  -------

   - Delete a number of old drivers still using virt_to_bus().

   - Ethernet NICs:
      - intel: support TSO on tunnels MPLS
      - broadcom: support multi-buffer XDP
      - nfp: support VF rate limiting
      - sfc: use hardware tx timestamps for more than PTP
      - mlx5: multi-port eswitch support
      - hyper-v: add support for XDP_REDIRECT
      - atlantic: XDP support (including multi-buffer)
      - macb: improve real-time perf by deferring Tx processing to NAPI

   - High-speed Ethernet switches:
      - mlxsw: implement basic line card information querying
      - prestera: add support for traffic policing on ingress and egress

   - Embedded Ethernet switches:
      - lan966x: add support for packet DMA (FDMA)
      - lan966x: add support for PTP programmable pins
      - ti: cpsw_new: enable bc/mc storm prevention

   - Qualcomm 802.11ax WiFi (ath11k):
      - Wake-on-WLAN support for QCA6390 and WCN6855
      - device recovery (firmware restart) support
      - support setting Specific Absorption Rate (SAR) for WCN6855
      - read country code from SMBIOS for WCN6855/QCA6390
      - enable keep-alive during WoWLAN suspend
      - implement remain-on-channel support

   - MediaTek WiFi (mt76):
      - support Wireless Ethernet Dispatch offloading packet movement
        between the Ethernet switch and WiFi interfaces
      - non-standard VHT MCS10-11 support
      - mt7921 AP mode support
      - mt7921 IPv6 NS offload support

   - Ethernet PHYs:
      - micrel: ksz9031/ksz9131: cabletest support
      - lan87xx: SQI support for T1 PHYs
      - lan937x: add interrupt support for link detection"

* tag 'net-next-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1809 commits)
  ptp: ocp: Add firmware header checks
  ptp: ocp: fix PPS source selector debugfs reporting
  ptp: ocp: add .init function for sma_op vector
  ptp: ocp: vectorize the sma accessor functions
  ptp: ocp: constify selectors
  ptp: ocp: parameterize input/output sma selectors
  ptp: ocp: revise firmware display
  ptp: ocp: add Celestica timecard PCI ids
  ptp: ocp: Remove #ifdefs around PCI IDs
  ptp: ocp: 32-bit fixups for pci start address
  Revert "net/smc: fix listen processing for SMC-Rv2"
  ath6kl: Use cc-disable-warning to disable -Wdangling-pointer
  selftests/bpf: Dynptr tests
  bpf: Add dynptr data slices
  bpf: Add bpf_dynptr_read and bpf_dynptr_write
  bpf: Dynptr support for ring buffers
  bpf: Add bpf_dynptr_from_mem for local dynptrs
  bpf: Add verifier support for dynptrs
  bpf: Suppress 'passing zero to PTR_ERR' warning
  bpf: Introduce bpf_arch_text_invalidate for bpf_prog_pack
  ...

1 files changed, 99 insertions, 78 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 60f99e9fb6d1..3231af73e430 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -414,7 +414,7 @@ static void tcp_sndbuf_expand(struct sock *sk)
 	per_mss = roundup_pow_of_two(per_mss) +
 		  SKB_DATA_ALIGN(sizeof(struct sk_buff));
 
-	nr_segs = max_t(u32, TCP_INIT_CWND, tp->snd_cwnd);
+	nr_segs = max_t(u32, TCP_INIT_CWND, tcp_snd_cwnd(tp));
 	nr_segs = max_t(u32, nr_segs, tp->reordering + 1);
 
 	/* Fast Recovery (RFC 5681 3.2) :
@@ -909,12 +909,12 @@ static void tcp_update_pacing_rate(struct sock *sk)
 	 *	 If snd_cwnd >= (tp->snd_ssthresh / 2), we are approaching
 	 *	 end of slow start and should slow down.
 	 */
-	if (tp->snd_cwnd < tp->snd_ssthresh / 2)
+	if (tcp_snd_cwnd(tp) < tp->snd_ssthresh / 2)
 		rate *= sock_net(sk)->ipv4.sysctl_tcp_pacing_ss_ratio;
 	else
 		rate *= sock_net(sk)->ipv4.sysctl_tcp_pacing_ca_ratio;
 
-	rate *= max(tp->snd_cwnd, tp->packets_out);
+	rate *= max(tcp_snd_cwnd(tp), tp->packets_out);
 
 	if (likely(tp->srtt_us))
 		do_div(rate, tp->srtt_us);
@@ -2147,12 +2147,12 @@ void tcp_enter_loss(struct sock *sk)
 	    !after(tp->high_seq, tp->snd_una) ||
 	    (icsk->icsk_ca_state == TCP_CA_Loss && !icsk->icsk_retransmits)) {
 		tp->prior_ssthresh = tcp_current_ssthresh(sk);
-		tp->prior_cwnd = tp->snd_cwnd;
+		tp->prior_cwnd = tcp_snd_cwnd(tp);
 		tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk);
 		tcp_ca_event(sk, CA_EVENT_LOSS);
 		tcp_init_undo(tp);
 	}
-	tp->snd_cwnd	   = tcp_packets_in_flight(tp) + 1;
+	tcp_snd_cwnd_set(tp, tcp_packets_in_flight(tp) + 1);
 	tp->snd_cwnd_cnt   = 0;
 	tp->snd_cwnd_stamp = tcp_jiffies32;
 
@@ -2458,7 +2458,7 @@ static void DBGUNDO(struct sock *sk, const char *msg)
 		pr_debug("Undo %s %pI4/%u c%u l%u ss%u/%u p%u\n",
 			 msg,
 			 &inet->inet_daddr, ntohs(inet->inet_dport),
-			 tp->snd_cwnd, tcp_left_out(tp),
+			 tcp_snd_cwnd(tp), tcp_left_out(tp),
 			 tp->snd_ssthresh, tp->prior_ssthresh,
 			 tp->packets_out);
 	}
@@ -2467,7 +2467,7 @@ static void DBGUNDO(struct sock *sk, const char *msg)
 		pr_debug("Undo %s %pI6/%u c%u l%u ss%u/%u p%u\n",
 			 msg,
 			 &sk->sk_v6_daddr, ntohs(inet->inet_dport),
-			 tp->snd_cwnd, tcp_left_out(tp),
+			 tcp_snd_cwnd(tp), tcp_left_out(tp),
 			 tp->snd_ssthresh, tp->prior_ssthresh,
 			 tp->packets_out);
 	}
@@ -2492,7 +2492,7 @@ static void tcp_undo_cwnd_reduction(struct sock *sk, bool unmark_loss)
 	if (tp->prior_ssthresh) {
 		const struct inet_connection_sock *icsk = inet_csk(sk);
 
-		tp->snd_cwnd = icsk->icsk_ca_ops->undo_cwnd(sk);
+		tcp_snd_cwnd_set(tp, icsk->icsk_ca_ops->undo_cwnd(sk));
 
 		if (tp->prior_ssthresh > tp->snd_ssthresh) {
 			tp->snd_ssthresh = tp->prior_ssthresh;
@@ -2599,7 +2599,7 @@ static void tcp_init_cwnd_reduction(struct sock *sk)
 	tp->high_seq = tp->snd_nxt;
 	tp->tlp_high_seq = 0;
 	tp->snd_cwnd_cnt = 0;
-	tp->prior_cwnd = tp->snd_cwnd;
+	tp->prior_cwnd = tcp_snd_cwnd(tp);
 	tp->prr_delivered = 0;
 	tp->prr_out = 0;
 	tp->snd_ssthresh = inet_csk(sk)->icsk_ca_ops->ssthresh(sk);
@@ -2620,16 +2620,16 @@ void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int newly_lost,
 		u64 dividend = (u64)tp->snd_ssthresh * tp->prr_delivered +
 			       tp->prior_cwnd - 1;
 		sndcnt = div_u64(dividend, tp->prior_cwnd) - tp->prr_out;
-	} else if (flag & FLAG_SND_UNA_ADVANCED && !newly_lost) {
-		sndcnt = min_t(int, delta,
-			       max_t(int, tp->prr_delivered - tp->prr_out,
-				     newly_acked_sacked) + 1);
 	} else {
-		sndcnt = min(delta, newly_acked_sacked);
+		sndcnt = max_t(int, tp->prr_delivered - tp->prr_out,
+			       newly_acked_sacked);
+		if (flag & FLAG_SND_UNA_ADVANCED && !newly_lost)
+			sndcnt++;
+		sndcnt = min(delta, sndcnt);
 	}
 	/* Force a fast retransmit upon entering fast recovery */
 	sndcnt = max(sndcnt, (tp->prr_out ? 0 : 1));
-	tp->snd_cwnd = tcp_packets_in_flight(tp) + sndcnt;
+	tcp_snd_cwnd_set(tp, tcp_packets_in_flight(tp) + sndcnt);
 }
 
 static inline void tcp_end_cwnd_reduction(struct sock *sk)
@@ -2642,7 +2642,7 @@ static inline void tcp_end_cwnd_reduction(struct sock *sk)
 	/* Reset cwnd to ssthresh in CWR or Recovery (unless it's undone) */
 	if (tp->snd_ssthresh < TCP_INFINITE_SSTHRESH &&
 	    (inet_csk(sk)->icsk_ca_state == TCP_CA_CWR || tp->undo_marker)) {
-		tp->snd_cwnd = tp->snd_ssthresh;
+		tcp_snd_cwnd_set(tp, tp->snd_ssthresh);
 		tp->snd_cwnd_stamp = tcp_jiffies32;
 	}
 	tcp_ca_event(sk, CA_EVENT_COMPLETE_CWR);
@@ -2709,9 +2709,9 @@ static void tcp_mtup_probe_success(struct sock *sk)
 
 	/* FIXME: breaks with very large cwnd */
 	tp->prior_ssthresh = tcp_current_ssthresh(sk);
-	tp->snd_cwnd = tp->snd_cwnd *
-		       tcp_mss_to_mtu(sk, tp->mss_cache) /
-		       icsk->icsk_mtup.probe_size;
+	tcp_snd_cwnd_set(tp, tcp_snd_cwnd(tp) *
+			     tcp_mss_to_mtu(sk, tp->mss_cache) /
+			     icsk->icsk_mtup.probe_size);
 	tp->snd_cwnd_cnt = 0;
 	tp->snd_cwnd_stamp = tcp_jiffies32;
 	tp->snd_ssthresh = tcp_current_ssthresh(sk);
@@ -3034,7 +3034,7 @@ static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una,
 		    tp->snd_una == tp->mtu_probe.probe_seq_start) {
 			tcp_mtup_probe_failed(sk);
 			/* Restores the reduction we did in tcp_mtup_probe() */
-			tp->snd_cwnd++;
+			tcp_snd_cwnd_set(tp, tcp_snd_cwnd(tp) + 1);
 			tcp_simple_retransmit(sk);
 			return;
 		}
@@ -3766,7 +3766,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 		if (before(ack, prior_snd_una - tp->max_window)) {
 			if (!(flag & FLAG_NO_CHALLENGE_ACK))
 				tcp_send_challenge_ack(sk);
-			return -1;
+			return -SKB_DROP_REASON_TCP_TOO_OLD_ACK;
 		}
 		goto old_ack;
 	}
@@ -3775,7 +3775,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 	 * this segment (RFC793 Section 3.9).
 	 */
 	if (after(ack, tp->snd_nxt))
-		return -1;
+		return -SKB_DROP_REASON_TCP_ACK_UNSENT_DATA;
 
 	if (after(ack, prior_snd_una)) {
 		flag |= FLAG_SND_UNA_ADVANCED;
@@ -4675,7 +4675,7 @@ static bool tcp_ooo_try_coalesce(struct sock *sk,
 {
 	bool res = tcp_try_coalesce(sk, to, from, fragstolen);
 
-	/* In case tcp_drop() is called later, update to->gso_segs */
+	/* In case tcp_drop_reason() is called later, update to->gso_segs */
 	if (res) {
 		u32 gso_segs = max_t(u16, 1, skb_shinfo(to)->gso_segs) +
 			       max_t(u16, 1, skb_shinfo(from)->gso_segs);
@@ -4692,11 +4692,6 @@ static void tcp_drop_reason(struct sock *sk, struct sk_buff *skb,
 	kfree_skb_reason(skb, reason);
 }
 
-static void tcp_drop(struct sock *sk, struct sk_buff *skb)
-{
-	tcp_drop_reason(sk, skb, SKB_DROP_REASON_NOT_SPECIFIED);
-}
-
 /* This one checks to see if we can put data from the
  * out_of_order queue into the receive_queue.
  */
@@ -4724,7 +4719,7 @@ static void tcp_ofo_queue(struct sock *sk)
 		rb_erase(&skb->rbnode, &tp->out_of_order_queue);
 
 		if (unlikely(!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))) {
-			tcp_drop(sk, skb);
+			tcp_drop_reason(sk, skb, SKB_DROP_REASON_TCP_OFO_DROP);
 			continue;
 		}
 
@@ -5335,7 +5330,8 @@ static bool tcp_prune_ofo_queue(struct sock *sk)
 		prev = rb_prev(node);
 		rb_erase(node, &tp->out_of_order_queue);
 		goal -= rb_to_skb(node)->truesize;
-		tcp_drop(sk, rb_to_skb(node));
+		tcp_drop_reason(sk, rb_to_skb(node),
+				SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE);
 		if (!prev || goal <= 0) {
 			sk_mem_reclaim(sk);
 			if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
@@ -5437,7 +5433,7 @@ static bool tcp_should_expand_sndbuf(struct sock *sk)
 		return false;
 
 	/* If we filled the congestion window, do not expand.  */
-	if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
+	if (tcp_packets_in_flight(tp) >= tcp_snd_cwnd(tp))
 		return false;
 
 	return true;
@@ -5678,7 +5674,7 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
 				  const struct tcphdr *th, int syn_inerr)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
-	bool rst_seq_match = false;
+	SKB_DR(reason);
 
 	/* RFC1323: H1. Apply PAWS check first. */
 	if (tcp_fast_parse_options(sock_net(sk), skb, th, tp) &&
@@ -5690,6 +5686,7 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
 						  LINUX_MIB_TCPACKSKIPPEDPAWS,
 						  &tp->last_oow_ack_time))
 				tcp_send_dupack(sk, skb);
+			SKB_DR_SET(reason, TCP_RFC7323_PAWS);
 			goto discard;
 		}
 		/* Reset is accepted even if it did not pass PAWS. */
@@ -5711,8 +5708,9 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
 						  &tp->last_oow_ack_time))
 				tcp_send_dupack(sk, skb);
 		} else if (tcp_reset_check(sk, skb)) {
-			tcp_reset(sk, skb);
+			goto reset;
 		}
+		SKB_DR_SET(reason, TCP_INVALID_SEQUENCE);
 		goto discard;
 	}
 
@@ -5728,9 +5726,10 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
 		 *     Send a challenge ACK
 		 */
 		if (TCP_SKB_CB(skb)->seq == tp->rcv_nxt ||
-		    tcp_reset_check(sk, skb)) {
-			rst_seq_match = true;
-		} else if (tcp_is_sack(tp) && tp->rx_opt.num_sacks > 0) {
+		    tcp_reset_check(sk, skb))
+			goto reset;
+
+		if (tcp_is_sack(tp) && tp->rx_opt.num_sacks > 0) {
 			struct tcp_sack_block *sp = &tp->selective_acks[0];
 			int max_sack = sp[0].end_seq;
 			int this_sack;
@@ -5743,21 +5742,18 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
 			}
 
 			if (TCP_SKB_CB(skb)->seq == max_sack)
-				rst_seq_match = true;
+				goto reset;
 		}
 
-		if (rst_seq_match)
-			tcp_reset(sk, skb);
-		else {
-			/* Disable TFO if RST is out-of-order
-			 * and no data has been received
-			 * for current active TFO socket
-			 */
-			if (tp->syn_fastopen && !tp->data_segs_in &&
-			    sk->sk_state == TCP_ESTABLISHED)
-				tcp_fastopen_active_disable(sk);
-			tcp_send_challenge_ack(sk);
-		}
+		/* Disable TFO if RST is out-of-order
+		 * and no data has been received
+		 * for current active TFO socket
+		 */
+		if (tp->syn_fastopen && !tp->data_segs_in &&
+		    sk->sk_state == TCP_ESTABLISHED)
+			tcp_fastopen_active_disable(sk);
+		tcp_send_challenge_ack(sk);
+		SKB_DR_SET(reason, TCP_RESET);
 		goto discard;
 	}
 
@@ -5772,6 +5768,7 @@ syn_challenge:
 			TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSYNCHALLENGE);
 		tcp_send_challenge_ack(sk);
+		SKB_DR_SET(reason, TCP_INVALID_SYN);
 		goto discard;
 	}
 
@@ -5780,7 +5777,12 @@ syn_challenge:
 	return true;
 
 discard:
-	tcp_drop(sk, skb);
+	tcp_drop_reason(sk, skb, reason);
+	return false;
+
+reset:
+	tcp_reset(sk, skb);
+	__kfree_skb(skb);
 	return false;
 }
 
@@ -5926,6 +5928,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
 			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPHPHITS);
 
 			/* Bulk data transfer: receiver */
+			skb_dst_drop(skb);
 			__skb_pull(skb, tcp_header_len);
 			eaten = tcp_queue_rcv(sk, skb, &fragstolen);
 
@@ -5967,9 +5970,11 @@ slow_path:
 		return;
 
 step5:
-	if (tcp_ack(sk, skb, FLAG_SLOWPATH | FLAG_UPDATE_TS_RECENT) < 0)
+	reason = tcp_ack(sk, skb, FLAG_SLOWPATH | FLAG_UPDATE_TS_RECENT);
+	if ((int)reason < 0) {
+		reason = -reason;
 		goto discard;
-
+	}
 	tcp_rcv_rtt_measure_ts(sk, skb);
 
 	/* Process urgent data. */
@@ -6009,9 +6014,9 @@ void tcp_init_transfer(struct sock *sk, int bpf_op, struct sk_buff *skb)
 	 * retransmission has occurred.
 	 */
 	if (tp->total_retrans > 1 && tp->undo_marker)
-		tp->snd_cwnd = 1;
+		tcp_snd_cwnd_set(tp, 1);
 	else
-		tp->snd_cwnd = tcp_init_cwnd(tp, __sk_dst_get(sk));
+		tcp_snd_cwnd_set(tp, tcp_init_cwnd(tp, __sk_dst_get(sk)));
 	tp->snd_cwnd_stamp = tcp_jiffies32;
 
 	bpf_skops_established(sk, bpf_op, skb);
@@ -6147,6 +6152,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
 	struct tcp_fastopen_cookie foc = { .len = -1 };
 	int saved_clamp = tp->rx_opt.mss_clamp;
 	bool fastopen_fail;
+	SKB_DR(reason);
 
 	tcp_parse_options(sock_net(sk), skb, &tp->rx_opt, 0, &foc);
 	if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr)
@@ -6189,7 +6195,9 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
 
 		if (th->rst) {
 			tcp_reset(sk, skb);
-			goto discard;
+consume:
+			__kfree_skb(skb);
+			return 0;
 		}
 
 		/* rfc793:
@@ -6199,9 +6207,10 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
 		 *    See note below!
 		 *                                        --ANK(990513)
 		 */
-		if (!th->syn)
+		if (!th->syn) {
+			SKB_DR_SET(reason, TCP_FLAGS);
 			goto discard_and_undo;
-
+		}
 		/* rfc793:
 		 *   "If the SYN bit is on ...
 		 *    are acceptable then ...
@@ -6278,13 +6287,9 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
 			tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS);
 			inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
 						  TCP_DELACK_MAX, TCP_RTO_MAX);
-
-discard:
-			tcp_drop(sk, skb);
-			return 0;
-		} else {
-			tcp_send_ack(sk);
+			goto consume;
 		}
+		tcp_send_ack(sk);
 		return -1;
 	}
 
@@ -6296,15 +6301,16 @@ discard:
 		 *
 		 *      Otherwise (no ACK) drop the segment and return."
 		 */
-
+		SKB_DR_SET(reason, TCP_RESET);
 		goto discard_and_undo;
 	}
 
 	/* PAWS check. */
 	if (tp->rx_opt.ts_recent_stamp && tp->rx_opt.saw_tstamp &&
-	    tcp_paws_reject(&tp->rx_opt, 0))
+	    tcp_paws_reject(&tp->rx_opt, 0)) {
+		SKB_DR_SET(reason, TCP_RFC7323_PAWS);
 		goto discard_and_undo;
-
+	}
 	if (th->syn) {
 		/* We see SYN without ACK. It is attempt of
 		 * simultaneous connect with crossed SYNs.
@@ -6353,7 +6359,7 @@ discard:
 		 */
 		return -1;
 #else
-		goto discard;
+		goto consume;
 #endif
 	}
 	/* "fifth, if neither of the SYN or RST bits is set then
@@ -6363,7 +6369,8 @@ discard:
 discard_and_undo:
 	tcp_clear_options(&tp->rx_opt);
 	tp->rx_opt.mss_clamp = saved_clamp;
-	goto discard;
+	tcp_drop_reason(sk, skb, reason);
+	return 0;
 
 reset_and_undo:
 	tcp_clear_options(&tp->rx_opt);
@@ -6418,21 +6425,26 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 	struct request_sock *req;
 	int queued = 0;
 	bool acceptable;
+	SKB_DR(reason);
 
 	switch (sk->sk_state) {
 	case TCP_CLOSE:
+		SKB_DR_SET(reason, TCP_CLOSE);
 		goto discard;
 
 	case TCP_LISTEN:
 		if (th->ack)
 			return 1;
 
-		if (th->rst)
+		if (th->rst) {
+			SKB_DR_SET(reason, TCP_RESET);
 			goto discard;
-
+		}
 		if (th->syn) {
-			if (th->fin)
+			if (th->fin) {
+				SKB_DR_SET(reason, TCP_FLAGS);
 				goto discard;
+			}
 			/* It is possible that we process SYN packets from backlog,
 			 * so we need to make sure to disable BH and RCU right there.
 			 */
@@ -6447,6 +6459,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 			consume_skb(skb);
 			return 0;
 		}
+		SKB_DR_SET(reason, TCP_FLAGS);
 		goto discard;
 
 	case TCP_SYN_SENT:
@@ -6473,13 +6486,16 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 		WARN_ON_ONCE(sk->sk_state != TCP_SYN_RECV &&
 		    sk->sk_state != TCP_FIN_WAIT1);
 
-		if (!tcp_check_req(sk, skb, req, true, &req_stolen))
+		if (!tcp_check_req(sk, skb, req, true, &req_stolen)) {
+			SKB_DR_SET(reason, TCP_FASTOPEN);
 			goto discard;
+		}
 	}
 
-	if (!th->ack && !th->rst && !th->syn)
+	if (!th->ack && !th->rst && !th->syn) {
+		SKB_DR_SET(reason, TCP_FLAGS);
 		goto discard;
-
+	}
 	if (!tcp_validate_incoming(sk, skb, th, 0))
 		return 0;
 
@@ -6492,6 +6508,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 		if (sk->sk_state == TCP_SYN_RECV)
 			return 1;	/* send one RST */
 		tcp_send_challenge_ack(sk);
+		SKB_DR_SET(reason, TCP_OLD_ACK);
 		goto discard;
 	}
 	switch (sk->sk_state) {
@@ -6585,7 +6602,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 			inet_csk_reset_keepalive_timer(sk, tmo);
 		} else {
 			tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
-			goto discard;
+			goto consume;
 		}
 		break;
 	}
@@ -6593,7 +6610,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 	case TCP_CLOSING:
 		if (tp->snd_una == tp->write_seq) {
 			tcp_time_wait(sk, TCP_TIME_WAIT, 0);
-			goto discard;
+			goto consume;
 		}
 		break;
 
@@ -6601,7 +6618,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 		if (tp->snd_una == tp->write_seq) {
 			tcp_update_metrics(sk);
 			tcp_done(sk);
-			goto discard;
+			goto consume;
 		}
 		break;
 	}
@@ -6652,9 +6669,13 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 
 	if (!queued) {
 discard:
-		tcp_drop(sk, skb);
+		tcp_drop_reason(sk, skb, reason);
 	}
 	return 0;
+
+consume:
+	__kfree_skb(skb);
+	return 0;
 }
 EXPORT_SYMBOL(tcp_rcv_state_process);