1 files changed, 428 insertions, 900 deletions

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 721d847ba92b..367927a99881 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -1,35 +1,18 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
-/* RxRPC packet reception
+/* Processing of received RxRPC packets
  *
- * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
-#include <linux/module.h>
-#include <linux/net.h>
-#include <linux/skbuff.h>
-#include <linux/errqueue.h>
-#include <linux/udp.h>
-#include <linux/in.h>
-#include <linux/in6.h>
-#include <linux/icmp.h>
-#include <linux/gfp.h>
-#include <net/sock.h>
-#include <net/af_rxrpc.h>
-#include <net/ip.h>
-#include <net/udp.h>
-#include <net/net_namespace.h>
 #include "ar-internal.h"
 
-static void rxrpc_proto_abort(const char *why,
-			      struct rxrpc_call *call, rxrpc_seq_t seq)
+static void rxrpc_proto_abort(struct rxrpc_call *call, rxrpc_seq_t seq,
+			      enum rxrpc_abort_reason why)
 {
-	if (rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, -EBADMSG)) {
-		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
-		rxrpc_queue_call(call);
-	}
+	rxrpc_abort_call(call, seq, RX_PROTOCOL_ERROR, -EBADMSG, why);
 }
 
 /*
@@ -46,7 +29,7 @@ static void rxrpc_congestion_management(struct rxrpc_call *call,
 	bool resend = false;
 
 	summary->flight_size =
-		(call->tx_top - call->tx_hard_ack) - summary->nr_acks;
+		(call->tx_top - call->acks_hard_ack) - summary->nr_acks;
 
 	if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) {
 		summary->retrans_timeo = true;
@@ -74,7 +57,7 @@ static void rxrpc_congestion_management(struct rxrpc_call *call,
 
 	switch (call->cong_mode) {
 	case RXRPC_CALL_SLOW_START:
-		if (summary->nr_nacks > 0)
+		if (summary->saw_nacks)
 			goto packet_loss_detected;
 		if (summary->cumulative_acks > 0)
 			cwnd += 1;
@@ -85,7 +68,7 @@ static void rxrpc_congestion_management(struct rxrpc_call *call,
 		goto out;
 
 	case RXRPC_CALL_CONGEST_AVOIDANCE:
-		if (summary->nr_nacks > 0)
+		if (summary->saw_nacks)
 			goto packet_loss_detected;
 
 		/* We analyse the number of packets that get ACK'd per RTT
@@ -104,7 +87,7 @@ static void rxrpc_congestion_management(struct rxrpc_call *call,
 		goto out;
 
 	case RXRPC_CALL_PACKET_LOSS:
-		if (summary->nr_nacks == 0)
+		if (!summary->saw_nacks)
 			goto resume_normality;
 
 		if (summary->new_low_nack) {
@@ -142,7 +125,7 @@ static void rxrpc_congestion_management(struct rxrpc_call *call,
 		} else {
 			change = rxrpc_cong_progress;
 			cwnd = call->cong_ssthresh;
-			if (summary->nr_nacks == 0)
+			if (!summary->saw_nacks)
 				goto resume_normality;
 		}
 		goto out;
@@ -164,13 +147,13 @@ resume_normality:
 out:
 	cumulative_acks = 0;
 out_no_clear_ca:
-	if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1)
-		cwnd = RXRPC_RXTX_BUFF_SIZE - 1;
+	if (cwnd >= RXRPC_TX_MAX_WINDOW)
+		cwnd = RXRPC_TX_MAX_WINDOW;
 	call->cong_cwnd = cwnd;
 	call->cong_cumul_acks = cumulative_acks;
 	trace_rxrpc_congest(call, summary, acked_serial, change);
-	if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
-		rxrpc_queue_call(call);
+	if (resend)
+		rxrpc_resend(call, skb);
 	return;
 
 packet_loss_detected:
@@ -183,9 +166,8 @@ send_extra_data:
 	/* Send some previously unsent DATA if we have some to advance the ACK
 	 * state.
 	 */
-	if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
-	    RXRPC_TX_ANNO_LAST ||
-	    summary->nr_acks != call->tx_top - call->tx_hard_ack) {
+	if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) ||
+	    summary->nr_acks != call->tx_top - call->acks_hard_ack) {
 		call->cong_extra++;
 		wake_up(&call->waitq);
 	}
@@ -193,58 +175,71 @@ send_extra_data:
 }
 
 /*
+ * Degrade the congestion window if we haven't transmitted a packet for >1RTT.
+ */
+void rxrpc_congestion_degrade(struct rxrpc_call *call)
+{
+	ktime_t rtt, now;
+
+	if (call->cong_mode != RXRPC_CALL_SLOW_START &&
+	    call->cong_mode != RXRPC_CALL_CONGEST_AVOIDANCE)
+		return;
+	if (__rxrpc_call_state(call) == RXRPC_CALL_CLIENT_AWAIT_REPLY)
+		return;
+
+	rtt = ns_to_ktime(call->peer->srtt_us * (1000 / 8));
+	now = ktime_get_real();
+	if (!ktime_before(ktime_add(call->tx_last_sent, rtt), now))
+		return;
+
+	trace_rxrpc_reset_cwnd(call, now);
+	rxrpc_inc_stat(call->rxnet, stat_tx_data_cwnd_reset);
+	call->tx_last_sent = now;
+	call->cong_mode = RXRPC_CALL_SLOW_START;
+	call->cong_ssthresh = max_t(unsigned int, call->cong_ssthresh,
+				    call->cong_cwnd * 3 / 4);
+	call->cong_cwnd = max_t(unsigned int, call->cong_cwnd / 2, RXRPC_MIN_CWND);
+}
+
+/*
  * Apply a hard ACK by advancing the Tx window.
  */
 static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
 				   struct rxrpc_ack_summary *summary)
 {
-	struct sk_buff *skb, *list = NULL;
+	struct rxrpc_txbuf *txb;
 	bool rot_last = false;
-	int ix;
-	u8 annotation;
-
-	if (call->acks_lowest_nak == call->tx_hard_ack) {
-		call->acks_lowest_nak = to;
-	} else if (before_eq(call->acks_lowest_nak, to)) {
-		summary->new_low_nack = true;
-		call->acks_lowest_nak = to;
-	}
-
-	spin_lock(&call->lock);
-
-	while (before(call->tx_hard_ack, to)) {
-		call->tx_hard_ack++;
-		ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK;
-		skb = call->rxtx_buffer[ix];
-		annotation = call->rxtx_annotations[ix];
-		rxrpc_see_skb(skb, rxrpc_skb_rotated);
-		call->rxtx_buffer[ix] = NULL;
-		call->rxtx_annotations[ix] = 0;
-		skb->next = list;
-		list = skb;
 
-		if (annotation & RXRPC_TX_ANNO_LAST) {
+	list_for_each_entry_rcu(txb, &call->tx_buffer, call_link, false) {
+		if (before_eq(txb->seq, call->acks_hard_ack))
+			continue;
+		summary->nr_rot_new_acks++;
+		if (test_bit(RXRPC_TXBUF_LAST, &txb->flags)) {
 			set_bit(RXRPC_CALL_TX_LAST, &call->flags);
 			rot_last = true;
 		}
-		if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK)
-			summary->nr_rot_new_acks++;
+		if (txb->seq == to)
+			break;
 	}
 
-	spin_unlock(&call->lock);
+	if (rot_last)
+		set_bit(RXRPC_CALL_TX_ALL_ACKED, &call->flags);
 
-	trace_rxrpc_transmit(call, (rot_last ?
-				    rxrpc_transmit_rotate_last :
-				    rxrpc_transmit_rotate));
-	wake_up(&call->waitq);
+	_enter("%x,%x,%x,%d", to, call->acks_hard_ack, call->tx_top, rot_last);
 
-	while (list) {
-		skb = list;
-		list = skb->next;
-		skb_mark_not_on_list(skb);
-		rxrpc_free_skb(skb, rxrpc_skb_freed);
+	if (call->acks_lowest_nak == call->acks_hard_ack) {
+		call->acks_lowest_nak = to;
+	} else if (after(to, call->acks_lowest_nak)) {
+		summary->new_low_nack = true;
+		call->acks_lowest_nak = to;
 	}
 
+	smp_store_release(&call->acks_hard_ack, to);
+
+	trace_rxrpc_txqueue(call, (rot_last ?
+				   rxrpc_txqueue_rotate_last :
+				   rxrpc_txqueue_rotate));
+	wake_up(&call->waitq);
 	return rot_last;
 }
 
@@ -254,47 +249,34 @@ static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
  * This occurs when we get an ACKALL packet, the first DATA packet of a reply,
  * or a final ACK packet.
  */
-static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
-			       const char *abort_why)
+static void rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
+			       enum rxrpc_abort_reason abort_why)
 {
-	unsigned int state;
-
 	ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
 
-	write_lock(&call->state_lock);
-
-	state = call->state;
-	switch (state) {
+	switch (__rxrpc_call_state(call)) {
 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
 	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
-		if (reply_begun)
-			call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY;
-		else
-			call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
+		if (reply_begun) {
+			rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_RECV_REPLY);
+			trace_rxrpc_txqueue(call, rxrpc_txqueue_end);
+			break;
+		}
+
+		rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_REPLY);
+		trace_rxrpc_txqueue(call, rxrpc_txqueue_await_reply);
 		break;
 
 	case RXRPC_CALL_SERVER_AWAIT_ACK:
-		__rxrpc_call_completed(call);
-		state = call->state;
+		rxrpc_call_completed(call);
+		trace_rxrpc_txqueue(call, rxrpc_txqueue_end);
 		break;
 
 	default:
-		goto bad_state;
+		kdebug("end_tx %s", rxrpc_call_states[__rxrpc_call_state(call)]);
+		rxrpc_proto_abort(call, call->tx_top, abort_why);
+		break;
 	}
-
-	write_unlock(&call->state_lock);
-	if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
-		trace_rxrpc_transmit(call, rxrpc_transmit_await_reply);
-	else
-		trace_rxrpc_transmit(call, rxrpc_transmit_end);
-	_leave(" = ok");
-	return true;
-
-bad_state:
-	write_unlock(&call->state_lock);
-	kdebug("end_tx %s", rxrpc_call_states[call->state]);
-	rxrpc_proto_abort(abort_why, call, call->tx_top);
-	return false;
 }
 
 /*
@@ -307,312 +289,328 @@ static bool rxrpc_receiving_reply(struct rxrpc_call *call)
 	rxrpc_seq_t top = READ_ONCE(call->tx_top);
 
 	if (call->ackr_reason) {
-		spin_lock_bh(&call->lock);
-		call->ackr_reason = 0;
-		spin_unlock_bh(&call->lock);
 		now = jiffies;
 		timo = now + MAX_JIFFY_OFFSET;
-		WRITE_ONCE(call->resend_at, timo);
-		WRITE_ONCE(call->ack_at, timo);
+
+		WRITE_ONCE(call->delay_ack_at, timo);
 		trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now);
 	}
 
 	if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
 		if (!rxrpc_rotate_tx_window(call, top, &summary)) {
-			rxrpc_proto_abort("TXL", call, top);
+			rxrpc_proto_abort(call, top, rxrpc_eproto_early_reply);
 			return false;
 		}
 	}
-	if (!rxrpc_end_tx_phase(call, true, "ETD"))
-		return false;
-	call->tx_phase = false;
+
+	rxrpc_end_tx_phase(call, true, rxrpc_eproto_unexpected_reply);
 	return true;
 }
 
 /*
- * Scan a data packet to validate its structure and to work out how many
- * subpackets it contains.
- *
- * A jumbo packet is a collection of consecutive packets glued together with
- * little headers between that indicate how to change the initial header for
- * each subpacket.
- *
- * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but
- * the last are RXRPC_JUMBO_DATALEN in size.  The last subpacket may be of any
- * size.
+ * End the packet reception phase.
  */
-static bool rxrpc_validate_data(struct sk_buff *skb)
+static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial)
 {
-	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	unsigned int offset = sizeof(struct rxrpc_wire_header);
-	unsigned int len = skb->len;
-	u8 flags = sp->hdr.flags;
+	rxrpc_seq_t whigh = READ_ONCE(call->rx_highest_seq);
 
-	for (;;) {
-		if (flags & RXRPC_REQUEST_ACK)
-			__set_bit(sp->nr_subpackets, sp->rx_req_ack);
-		sp->nr_subpackets++;
+	_enter("%d,%s", call->debug_id, rxrpc_call_states[__rxrpc_call_state(call)]);
 
-		if (!(flags & RXRPC_JUMBO_PACKET))
-			break;
+	trace_rxrpc_receive(call, rxrpc_receive_end, 0, whigh);
 
-		if (len - offset < RXRPC_JUMBO_SUBPKTLEN)
-			goto protocol_error;
-		if (flags & RXRPC_LAST_PACKET)
-			goto protocol_error;
-		offset += RXRPC_JUMBO_DATALEN;
-		if (skb_copy_bits(skb, offset, &flags, 1) < 0)
-			goto protocol_error;
-		offset += sizeof(struct rxrpc_jumbo_header);
-	}
+	switch (__rxrpc_call_state(call)) {
+	case RXRPC_CALL_CLIENT_RECV_REPLY:
+		rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_terminal_ack);
+		rxrpc_call_completed(call);
+		break;
 
-	if (flags & RXRPC_LAST_PACKET)
-		sp->rx_flags |= RXRPC_SKB_INCL_LAST;
-	return true;
+	case RXRPC_CALL_SERVER_RECV_REQUEST:
+		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_ACK_REQUEST);
+		call->expect_req_by = jiffies + MAX_JIFFY_OFFSET;
+		rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_processing_op);
+		break;
 
-protocol_error:
-	return false;
+	default:
+		break;
+	}
+}
+
+static void rxrpc_input_update_ack_window(struct rxrpc_call *call,
+					  rxrpc_seq_t window, rxrpc_seq_t wtop)
+{
+	atomic64_set_release(&call->ackr_window, ((u64)wtop) << 32 | window);
 }
 
 /*
- * Handle reception of a duplicate packet.
- *
- * We have to take care to avoid an attack here whereby we're given a series of
- * jumbograms, each with a sequence number one before the preceding one and
- * filled up to maximum UDP size.  If they never send us the first packet in
- * the sequence, they can cause us to have to hold on to around 2MiB of kernel
- * space until the call times out.
- *
- * We limit the space usage by only accepting three duplicate jumbo packets per
- * call.  After that, we tell the other side we're no longer accepting jumbos
- * (that information is encoded in the ACK packet).
+ * Push a DATA packet onto the Rx queue.
  */
-static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
-				 bool is_jumbo, bool *_jumbo_bad)
+static void rxrpc_input_queue_data(struct rxrpc_call *call, struct sk_buff *skb,
+				   rxrpc_seq_t window, rxrpc_seq_t wtop,
+				   enum rxrpc_receive_trace why)
 {
-	/* Discard normal packets that are duplicates. */
-	if (is_jumbo)
-		return;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
 
-	/* Skip jumbo subpackets that are duplicates.  When we've had three or
-	 * more partially duplicate jumbo packets, we refuse to take any more
-	 * jumbos for this call.
-	 */
-	if (!*_jumbo_bad) {
-		call->nr_jumbo_bad++;
-		*_jumbo_bad = true;
-	}
+	__skb_queue_tail(&call->recvmsg_queue, skb);
+	rxrpc_input_update_ack_window(call, window, wtop);
+	trace_rxrpc_receive(call, last ? why + 1 : why, sp->hdr.serial, sp->hdr.seq);
+	if (last)
+		rxrpc_end_rx_phase(call, sp->hdr.serial);
 }
 
 /*
- * Process a DATA packet, adding the packet to the Rx ring.  The caller's
- * packet ref must be passed on or discarded.
+ * Process a DATA packet.
  */
-static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
+static void rxrpc_input_data_one(struct rxrpc_call *call, struct sk_buff *skb,
+				 bool *_notify)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	enum rxrpc_call_state state;
-	unsigned int j, nr_subpackets, nr_unacked = 0;
-	rxrpc_serial_t serial = sp->hdr.serial, ack_serial = serial;
-	rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack;
-	bool immediate_ack = false, jumbo_bad = false;
-	u8 ack = 0;
-
-	_enter("{%u,%u},{%u,%u}",
-	       call->rx_hard_ack, call->rx_top, skb->len, seq0);
-
-	_proto("Rx DATA %%%u { #%u f=%02x n=%u }",
-	       sp->hdr.serial, seq0, sp->hdr.flags, sp->nr_subpackets);
-
-	state = READ_ONCE(call->state);
-	if (state >= RXRPC_CALL_COMPLETE) {
-		rxrpc_free_skb(skb, rxrpc_skb_freed);
-		return;
+	struct sk_buff *oos;
+	rxrpc_serial_t serial = sp->hdr.serial;
+	u64 win = atomic64_read(&call->ackr_window);
+	rxrpc_seq_t window = lower_32_bits(win);
+	rxrpc_seq_t wtop = upper_32_bits(win);
+	rxrpc_seq_t wlimit = window + call->rx_winsize - 1;
+	rxrpc_seq_t seq = sp->hdr.seq;
+	bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
+	int ack_reason = -1;
+
+	rxrpc_inc_stat(call->rxnet, stat_rx_data);
+	if (sp->hdr.flags & RXRPC_REQUEST_ACK)
+		rxrpc_inc_stat(call->rxnet, stat_rx_data_reqack);
+	if (sp->hdr.flags & RXRPC_JUMBO_PACKET)
+		rxrpc_inc_stat(call->rxnet, stat_rx_data_jumbo);
+
+	if (last) {
+		if (test_and_set_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+		    seq + 1 != wtop)
+			return rxrpc_proto_abort(call, seq, rxrpc_eproto_different_last);
+	} else {
+		if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+		    after_eq(seq, wtop)) {
+			pr_warn("Packet beyond last: c=%x q=%x window=%x-%x wlimit=%x\n",
+				call->debug_id, seq, window, wtop, wlimit);
+			return rxrpc_proto_abort(call, seq, rxrpc_eproto_data_after_last);
+		}
 	}
 
-	if (state == RXRPC_CALL_SERVER_RECV_REQUEST) {
-		unsigned long timo = READ_ONCE(call->next_req_timo);
-		unsigned long now, expect_req_by;
+	if (after(seq, call->rx_highest_seq))
+		call->rx_highest_seq = seq;
 
-		if (timo) {
-			now = jiffies;
-			expect_req_by = now + timo;
-			WRITE_ONCE(call->expect_req_by, expect_req_by);
-			rxrpc_reduce_call_timer(call, expect_req_by, now,
-						rxrpc_timer_set_for_idle);
-		}
+	trace_rxrpc_rx_data(call->debug_id, seq, serial, sp->hdr.flags);
+
+	if (before(seq, window)) {
+		ack_reason = RXRPC_ACK_DUPLICATE;
+		goto send_ack;
+	}
+	if (after(seq, wlimit)) {
+		ack_reason = RXRPC_ACK_EXCEEDS_WINDOW;
+		goto send_ack;
 	}
 
-	spin_lock(&call->input_lock);
+	/* Queue the packet. */
+	if (seq == window) {
+		rxrpc_seq_t reset_from;
+		bool reset_sack = false;
 
-	/* Received data implicitly ACKs all of the request packets we sent
-	 * when we're acting as a client.
-	 */
-	if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
-	     state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
-	    !rxrpc_receiving_reply(call))
-		goto unlock;
-
-	hard_ack = READ_ONCE(call->rx_hard_ack);
-
-	nr_subpackets = sp->nr_subpackets;
-	if (nr_subpackets > 1) {
-		if (call->nr_jumbo_bad > 3) {
-			ack = RXRPC_ACK_NOSPACE;
-			ack_serial = serial;
-			goto ack;
-		}
-	}
+		if (sp->hdr.flags & RXRPC_REQUEST_ACK)
+			ack_reason = RXRPC_ACK_REQUESTED;
+		/* Send an immediate ACK if we fill in a hole */
+		else if (!skb_queue_empty(&call->rx_oos_queue))
+			ack_reason = RXRPC_ACK_DELAY;
+		else
+			atomic_inc_return(&call->ackr_nr_unacked);
 
-	for (j = 0; j < nr_subpackets; j++) {
-		rxrpc_serial_t serial = sp->hdr.serial + j;
-		rxrpc_seq_t seq = seq0 + j;
-		unsigned int ix = seq & RXRPC_RXTX_BUFF_MASK;
-		bool terminal = (j == nr_subpackets - 1);
-		bool last = terminal && (sp->rx_flags & RXRPC_SKB_INCL_LAST);
-		u8 flags, annotation = j;
-
-		_proto("Rx DATA+%u %%%u { #%x t=%u l=%u }",
-		     j, serial, seq, terminal, last);
-
-		if (last) {
-			if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
-			    seq != call->rx_top) {
-				rxrpc_proto_abort("LSN", call, seq);
-				goto unlock;
-			}
-		} else {
-			if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
-			    after_eq(seq, call->rx_top)) {
-				rxrpc_proto_abort("LSA", call, seq);
-				goto unlock;
+		window++;
+		if (after(window, wtop))
+			wtop = window;
+
+		rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg);
+
+		spin_lock(&call->recvmsg_queue.lock);
+		rxrpc_input_queue_data(call, skb, window, wtop, rxrpc_receive_queue);
+		*_notify = true;
+
+		while ((oos = skb_peek(&call->rx_oos_queue))) {
+			struct rxrpc_skb_priv *osp = rxrpc_skb(oos);
+
+			if (after(osp->hdr.seq, window))
+				break;
+
+			__skb_unlink(oos, &call->rx_oos_queue);
+			last = osp->hdr.flags & RXRPC_LAST_PACKET;
+			seq = osp->hdr.seq;
+			if (!reset_sack) {
+				reset_from = seq;
+				reset_sack = true;
 			}
-		}
 
-		flags = 0;
-		if (last)
-			flags |= RXRPC_LAST_PACKET;
-		if (!terminal)
-			flags |= RXRPC_JUMBO_PACKET;
-		if (test_bit(j, sp->rx_req_ack))
-			flags |= RXRPC_REQUEST_ACK;
-		trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation);
-
-		if (before_eq(seq, hard_ack)) {
-			ack = RXRPC_ACK_DUPLICATE;
-			ack_serial = serial;
-			continue;
+			window++;
+			rxrpc_input_queue_data(call, oos, window, wtop,
+						 rxrpc_receive_queue_oos);
 		}
 
-		if (call->rxtx_buffer[ix]) {
-			rxrpc_input_dup_data(call, seq, nr_subpackets > 1,
-					     &jumbo_bad);
-			if (ack != RXRPC_ACK_DUPLICATE) {
-				ack = RXRPC_ACK_DUPLICATE;
-				ack_serial = serial;
-			}
-			immediate_ack = true;
-			continue;
+		spin_unlock(&call->recvmsg_queue.lock);
+
+		if (reset_sack) {
+			do {
+				call->ackr_sack_table[reset_from % RXRPC_SACK_SIZE] = 0;
+			} while (reset_from++, before(reset_from, window));
 		}
+	} else {
+		bool keep = false;
 
-		if (after(seq, hard_ack + call->rx_winsize)) {
-			ack = RXRPC_ACK_EXCEEDS_WINDOW;
-			ack_serial = serial;
-			if (flags & RXRPC_JUMBO_PACKET) {
-				if (!jumbo_bad) {
-					call->nr_jumbo_bad++;
-					jumbo_bad = true;
-				}
-			}
+		ack_reason = RXRPC_ACK_OUT_OF_SEQUENCE;
 
-			goto ack;
+		if (!call->ackr_sack_table[seq % RXRPC_SACK_SIZE]) {
+			call->ackr_sack_table[seq % RXRPC_SACK_SIZE] = 1;
+			keep = 1;
 		}
 
-		if (flags & RXRPC_REQUEST_ACK && !ack) {
-			ack = RXRPC_ACK_REQUESTED;
-			ack_serial = serial;
+		if (after(seq + 1, wtop)) {
+			wtop = seq + 1;
+			rxrpc_input_update_ack_window(call, window, wtop);
 		}
 
-		if (after(seq0, call->ackr_highest_seq))
-			call->ackr_highest_seq = seq0;
+		if (!keep) {
+			ack_reason = RXRPC_ACK_DUPLICATE;
+			goto send_ack;
+		}
 
-		/* Queue the packet.  We use a couple of memory barriers here as need
-		 * to make sure that rx_top is perceived to be set after the buffer
-		 * pointer and that the buffer pointer is set after the annotation and
-		 * the skb data.
-		 *
-		 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
-		 * and also rxrpc_fill_out_ack().
-		 */
-		if (!terminal)
-			rxrpc_get_skb(skb, rxrpc_skb_got);
-		call->rxtx_annotations[ix] = annotation;
-		smp_wmb();
-		call->rxtx_buffer[ix] = skb;
-		if (after(seq, call->rx_top)) {
-			smp_store_release(&call->rx_top, seq);
-		} else if (before(seq, call->rx_top)) {
-			/* Send an immediate ACK if we fill in a hole */
-			if (!ack) {
-				ack = RXRPC_ACK_DELAY;
-				ack_serial = serial;
+		skb_queue_walk(&call->rx_oos_queue, oos) {
+			struct rxrpc_skb_priv *osp = rxrpc_skb(oos);
+
+			if (after(osp->hdr.seq, seq)) {
+				rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos);
+				__skb_queue_before(&call->rx_oos_queue, oos, skb);
+				goto oos_queued;
 			}
-			immediate_ack = true;
 		}
 
-		if (terminal) {
-			/* From this point on, we're not allowed to touch the
-			 * packet any longer as its ref now belongs to the Rx
-			 * ring.
-			 */
-			skb = NULL;
-			sp = NULL;
-		}
+		rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos);
+		__skb_queue_tail(&call->rx_oos_queue, skb);
+	oos_queued:
+		trace_rxrpc_receive(call, last ? rxrpc_receive_oos_last : rxrpc_receive_oos,
+				    sp->hdr.serial, sp->hdr.seq);
+	}
 
-		nr_unacked++;
+send_ack:
+	if (ack_reason >= 0)
+		rxrpc_send_ACK(call, ack_reason, serial,
+			       rxrpc_propose_ack_input_data);
+	else
+		rxrpc_propose_delay_ACK(call, serial,
+					rxrpc_propose_ack_input_data);
+}
 
-		if (last) {
-			set_bit(RXRPC_CALL_RX_LAST, &call->flags);
-			if (!ack) {
-				ack = RXRPC_ACK_DELAY;
-				ack_serial = serial;
-			}
-			trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
-		} else {
-			trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
+/*
+ * Split a jumbo packet and file the bits separately.
+ */
+static bool rxrpc_input_split_jumbo(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_jumbo_header jhdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb), *jsp;
+	struct sk_buff *jskb;
+	unsigned int offset = sizeof(struct rxrpc_wire_header);
+	unsigned int len = skb->len - offset;
+	bool notify = false;
+
+	while (sp->hdr.flags & RXRPC_JUMBO_PACKET) {
+		if (len < RXRPC_JUMBO_SUBPKTLEN)
+			goto protocol_error;
+		if (sp->hdr.flags & RXRPC_LAST_PACKET)
+			goto protocol_error;
+		if (skb_copy_bits(skb, offset + RXRPC_JUMBO_DATALEN,
+				  &jhdr, sizeof(jhdr)) < 0)
+			goto protocol_error;
+
+		jskb = skb_clone(skb, GFP_NOFS);
+		if (!jskb) {
+			kdebug("couldn't clone");
+			return false;
 		}
+		rxrpc_new_skb(jskb, rxrpc_skb_new_jumbo_subpacket);
+		jsp = rxrpc_skb(jskb);
+		jsp->offset = offset;
+		jsp->len = RXRPC_JUMBO_DATALEN;
+		rxrpc_input_data_one(call, jskb, &notify);
+		rxrpc_free_skb(jskb, rxrpc_skb_put_jumbo_subpacket);
+
+		sp->hdr.flags = jhdr.flags;
+		sp->hdr._rsvd = ntohs(jhdr._rsvd);
+		sp->hdr.seq++;
+		sp->hdr.serial++;
+		offset += RXRPC_JUMBO_SUBPKTLEN;
+		len -= RXRPC_JUMBO_SUBPKTLEN;
+	}
 
-		if (after_eq(seq, call->rx_expect_next)) {
-			if (after(seq, call->rx_expect_next)) {
-				_net("OOS %u > %u", seq, call->rx_expect_next);
-				ack = RXRPC_ACK_OUT_OF_SEQUENCE;
-				ack_serial = serial;
-			}
-			call->rx_expect_next = seq + 1;
+	sp->offset = offset;
+	sp->len    = len;
+	rxrpc_input_data_one(call, skb, &notify);
+	if (notify) {
+		trace_rxrpc_notify_socket(call->debug_id, sp->hdr.serial);
+		rxrpc_notify_socket(call);
+	}
+	return true;
+
+protocol_error:
+	return false;
+}
+
+/*
+ * Process a DATA packet, adding the packet to the Rx ring.  The caller's
+ * packet ref must be passed on or discarded.
+ */
+static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	rxrpc_serial_t serial = sp->hdr.serial;
+	rxrpc_seq_t seq0 = sp->hdr.seq;
+
+	_enter("{%llx,%x},{%u,%x}",
+	       atomic64_read(&call->ackr_window), call->rx_highest_seq,
+	       skb->len, seq0);
+
+	if (__rxrpc_call_is_complete(call))
+		return;
+
+	switch (__rxrpc_call_state(call)) {
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+		/* Received data implicitly ACKs all of the request
+		 * packets we sent when we're acting as a client.
+		 */
+		if (!rxrpc_receiving_reply(call))
+			goto out_notify;
+		break;
+
+	case RXRPC_CALL_SERVER_RECV_REQUEST: {
+		unsigned long timo = READ_ONCE(call->next_req_timo);
+		unsigned long now, expect_req_by;
+
+		if (timo) {
+			now = jiffies;
+			expect_req_by = now + timo;
+			WRITE_ONCE(call->expect_req_by, expect_req_by);
+			rxrpc_reduce_call_timer(call, expect_req_by, now,
+						rxrpc_timer_set_for_idle);
 		}
-		if (!ack)
-			ack_serial = serial;
+		break;
 	}
 
-ack:
-	if (atomic_add_return(nr_unacked, &call->ackr_nr_unacked) > 2 && !ack)
-		ack = RXRPC_ACK_IDLE;
+	default:
+		break;
+	}
 
-	if (ack)
-		rxrpc_propose_ACK(call, ack, ack_serial,
-				  immediate_ack, true,
-				  rxrpc_propose_ack_input_data);
-	else
-		rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial,
-				  false, true,
-				  rxrpc_propose_ack_input_data);
+	if (!rxrpc_input_split_jumbo(call, skb)) {
+		rxrpc_proto_abort(call, sp->hdr.seq, rxrpc_badmsg_bad_jumbo);
+		goto out_notify;
+	}
+	skb = NULL;
 
+out_notify:
 	trace_rxrpc_notify_socket(call->debug_id, serial);
 	rxrpc_notify_socket(call);
-
-unlock:
-	spin_unlock(&call->input_lock);
-	rxrpc_free_skb(skb, rxrpc_skb_freed);
 	_leave(" [queued]");
 }
 
@@ -671,55 +669,6 @@ static void rxrpc_complete_rtt_probe(struct rxrpc_call *call,
 }
 
 /*
- * Process the response to a ping that we sent to find out if we lost an ACK.
- *
- * If we got back a ping response that indicates a lower tx_top than what we
- * had at the time of the ping transmission, we adjudge all the DATA packets
- * sent between the response tx_top and the ping-time tx_top to have been lost.
- */
-static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call)
-{
-	rxrpc_seq_t top, bottom, seq;
-	bool resend = false;
-
-	spin_lock_bh(&call->lock);
-
-	bottom = call->tx_hard_ack + 1;
-	top = call->acks_lost_top;
-	if (before(bottom, top)) {
-		for (seq = bottom; before_eq(seq, top); seq++) {
-			int ix = seq & RXRPC_RXTX_BUFF_MASK;
-			u8 annotation = call->rxtx_annotations[ix];
-			u8 anno_type = annotation & RXRPC_TX_ANNO_MASK;
-
-			if (anno_type != RXRPC_TX_ANNO_UNACK)
-				continue;
-			annotation &= ~RXRPC_TX_ANNO_MASK;
-			annotation |= RXRPC_TX_ANNO_RETRANS;
-			call->rxtx_annotations[ix] = annotation;
-			resend = true;
-		}
-	}
-
-	spin_unlock_bh(&call->lock);
-
-	if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
-		rxrpc_queue_call(call);
-}
-
-/*
- * Process a ping response.
- */
-static void rxrpc_input_ping_response(struct rxrpc_call *call,
-				      ktime_t resp_time,
-				      rxrpc_serial_t acked_serial,
-				      rxrpc_serial_t ack_serial)
-{
-	if (acked_serial == call->acks_lost_ping)
-		rxrpc_input_check_for_lost_ack(call);
-}
-
-/*
  * Process the extra information that may be appended to an ACK packet
  */
 static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
@@ -731,13 +680,8 @@ static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
 	bool wake = false;
 	u32 rwind = ntohl(ackinfo->rwind);
 
-	_proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
-	       sp->hdr.serial,
-	       ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU),
-	       rwind, ntohl(ackinfo->jumbo_max));
-
-	if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
-		rwind = RXRPC_RXTX_BUFF_SIZE - 1;
+	if (rwind > RXRPC_TX_MAX_WINDOW)
+		rwind = RXRPC_TX_MAX_WINDOW;
 	if (call->tx_winsize != rwind) {
 		if (rwind > call->tx_winsize)
 			wake = true;
@@ -752,11 +696,10 @@ static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
 
 	peer = call->peer;
 	if (mtu < peer->maxdata) {
-		spin_lock_bh(&peer->lock);
+		spin_lock(&peer->lock);
 		peer->maxdata = mtu;
 		peer->mtu = mtu + peer->hdrsize;
-		spin_unlock_bh(&peer->lock);
-		_net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
+		spin_unlock(&peer->lock);
 	}
 
 	if (wake)
@@ -776,40 +719,19 @@ static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
 				  rxrpc_seq_t seq, int nr_acks,
 				  struct rxrpc_ack_summary *summary)
 {
-	int ix;
-	u8 annotation, anno_type;
-
-	for (; nr_acks > 0; nr_acks--, seq++) {
-		ix = seq & RXRPC_RXTX_BUFF_MASK;
-		annotation = call->rxtx_annotations[ix];
-		anno_type = annotation & RXRPC_TX_ANNO_MASK;
-		annotation &= ~RXRPC_TX_ANNO_MASK;
-		switch (*acks++) {
-		case RXRPC_ACK_TYPE_ACK:
+	unsigned int i;
+
+	for (i = 0; i < nr_acks; i++) {
+		if (acks[i] == RXRPC_ACK_TYPE_ACK) {
 			summary->nr_acks++;
-			if (anno_type == RXRPC_TX_ANNO_ACK)
-				continue;
 			summary->nr_new_acks++;
-			call->rxtx_annotations[ix] =
-				RXRPC_TX_ANNO_ACK | annotation;
-			break;
-		case RXRPC_ACK_TYPE_NACK:
-			if (!summary->nr_nacks &&
-			    call->acks_lowest_nak != seq) {
-				call->acks_lowest_nak = seq;
+		} else {
+			if (!summary->saw_nacks &&
+			    call->acks_lowest_nak != seq + i) {
+				call->acks_lowest_nak = seq + i;
 				summary->new_low_nack = true;
 			}
-			summary->nr_nacks++;
-			if (anno_type == RXRPC_TX_ANNO_NAK)
-				continue;
-			summary->nr_new_nacks++;
-			if (anno_type == RXRPC_TX_ANNO_RETRANS)
-				continue;
-			call->rxtx_annotations[ix] =
-				RXRPC_TX_ANNO_NAK | annotation;
-			break;
-		default:
-			return rxrpc_proto_abort("SFT", call, 0);
+			summary->saw_nacks = true;
 		}
 	}
 }
@@ -851,12 +773,9 @@ static bool rxrpc_is_ack_valid(struct rxrpc_call *call,
 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_ack_summary summary = { 0 };
+	struct rxrpc_ackpacket ack;
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	union {
-		struct rxrpc_ackpacket ack;
-		struct rxrpc_ackinfo info;
-		u8 acks[RXRPC_MAXACKS];
-	} buf;
+	struct rxrpc_ackinfo info;
 	rxrpc_serial_t ack_serial, acked_serial;
 	rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
 	int nr_acks, offset, ioffset;
@@ -864,29 +783,26 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 	_enter("");
 
 	offset = sizeof(struct rxrpc_wire_header);
-	if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) {
-		_debug("extraction failure");
-		return rxrpc_proto_abort("XAK", call, 0);
-	}
-	offset += sizeof(buf.ack);
+	if (skb_copy_bits(skb, offset, &ack, sizeof(ack)) < 0)
+		return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack);
+	offset += sizeof(ack);
 
 	ack_serial = sp->hdr.serial;
-	acked_serial = ntohl(buf.ack.serial);
-	first_soft_ack = ntohl(buf.ack.firstPacket);
-	prev_pkt = ntohl(buf.ack.previousPacket);
+	acked_serial = ntohl(ack.serial);
+	first_soft_ack = ntohl(ack.firstPacket);
+	prev_pkt = ntohl(ack.previousPacket);
 	hard_ack = first_soft_ack - 1;
-	nr_acks = buf.ack.nAcks;
-	summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
-			      buf.ack.reason : RXRPC_ACK__INVALID);
+	nr_acks = ack.nAcks;
+	summary.ack_reason = (ack.reason < RXRPC_ACK__INVALID ?
+			      ack.reason : RXRPC_ACK__INVALID);
 
 	trace_rxrpc_rx_ack(call, ack_serial, acked_serial,
 			   first_soft_ack, prev_pkt,
 			   summary.ack_reason, nr_acks);
+	rxrpc_inc_stat(call->rxnet, stat_rx_acks[ack.reason]);
 
-	switch (buf.ack.reason) {
+	switch (ack.reason) {
 	case RXRPC_ACK_PING_RESPONSE:
-		rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
-					  ack_serial);
 		rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
 					 rxrpc_rtt_rx_ping_response);
 		break;
@@ -901,22 +817,19 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 		break;
 	}
 
-	if (buf.ack.reason == RXRPC_ACK_PING) {
-		_proto("Rx ACK %%%u PING Request", ack_serial);
-		rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
-				  ack_serial, true, true,
-				  rxrpc_propose_ack_respond_to_ping);
+	if (ack.reason == RXRPC_ACK_PING) {
+		rxrpc_send_ACK(call, RXRPC_ACK_PING_RESPONSE, ack_serial,
+			       rxrpc_propose_ack_respond_to_ping);
 	} else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
-		rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
-				  ack_serial, true, true,
-				  rxrpc_propose_ack_respond_to_ack);
+		rxrpc_send_ACK(call, RXRPC_ACK_REQUESTED, ack_serial,
+			       rxrpc_propose_ack_respond_to_ack);
 	}
 
 	/* If we get an EXCEEDS_WINDOW ACK from the server, it probably
 	 * indicates that the client address changed due to NAT.  The server
 	 * lost the call because it switched to a different peer.
 	 */
-	if (unlikely(buf.ack.reason == RXRPC_ACK_EXCEEDS_WINDOW) &&
+	if (unlikely(ack.reason == RXRPC_ACK_EXCEEDS_WINDOW) &&
 	    first_soft_ack == 1 &&
 	    prev_pkt == 0 &&
 	    rxrpc_is_client_call(call)) {
@@ -929,10 +842,10 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 	 * indicate a change of address.  However, we can retransmit the call
 	 * if we still have it buffered to the beginning.
 	 */
-	if (unlikely(buf.ack.reason == RXRPC_ACK_OUT_OF_SEQUENCE) &&
+	if (unlikely(ack.reason == RXRPC_ACK_OUT_OF_SEQUENCE) &&
 	    first_soft_ack == 1 &&
 	    prev_pkt == 0 &&
-	    call->tx_hard_ack == 0 &&
+	    call->acks_hard_ack == 0 &&
 	    rxrpc_is_client_call(call)) {
 		rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
 					  0, -ENETRESET);
@@ -947,83 +860,73 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 		return;
 	}
 
-	buf.info.rxMTU = 0;
+	info.rxMTU = 0;
 	ioffset = offset + nr_acks + 3;
-	if (skb->len >= ioffset + sizeof(buf.info) &&
-	    skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0)
-		return rxrpc_proto_abort("XAI", call, 0);
+	if (skb->len >= ioffset + sizeof(info) &&
+	    skb_copy_bits(skb, ioffset, &info, sizeof(info)) < 0)
+		return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack_info);
 
-	spin_lock(&call->input_lock);
+	if (nr_acks > 0)
+		skb_condense(skb);
 
-	/* Discard any out-of-order or duplicate ACKs (inside lock). */
-	if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
-		trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
-					   first_soft_ack, call->acks_first_seq,
-					   prev_pkt, call->acks_prev_seq);
-		goto out;
-	}
 	call->acks_latest_ts = skb->tstamp;
-
 	call->acks_first_seq = first_soft_ack;
 	call->acks_prev_seq = prev_pkt;
 
+	switch (ack.reason) {
+	case RXRPC_ACK_PING:
+		break;
+	default:
+		if (after(acked_serial, call->acks_highest_serial))
+			call->acks_highest_serial = acked_serial;
+		break;
+	}
+
 	/* Parse rwind and mtu sizes if provided. */
-	if (buf.info.rxMTU)
-		rxrpc_input_ackinfo(call, skb, &buf.info);
+	if (info.rxMTU)
+		rxrpc_input_ackinfo(call, skb, &info);
 
-	if (first_soft_ack == 0) {
-		rxrpc_proto_abort("AK0", call, 0);
-		goto out;
-	}
+	if (first_soft_ack == 0)
+		return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_zero);
 
 	/* Ignore ACKs unless we are or have just been transmitting. */
-	switch (READ_ONCE(call->state)) {
+	switch (__rxrpc_call_state(call)) {
 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
 	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
 	case RXRPC_CALL_SERVER_SEND_REPLY:
 	case RXRPC_CALL_SERVER_AWAIT_ACK:
 		break;
 	default:
-		goto out;
+		return;
 	}
 
-	if (before(hard_ack, call->tx_hard_ack) ||
-	    after(hard_ack, call->tx_top)) {
-		rxrpc_proto_abort("AKW", call, 0);
-		goto out;
-	}
-	if (nr_acks > call->tx_top - hard_ack) {
-		rxrpc_proto_abort("AKN", call, 0);
-		goto out;
-	}
+	if (before(hard_ack, call->acks_hard_ack) ||
+	    after(hard_ack, call->tx_top))
+		return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_outside_window);
+	if (nr_acks > call->tx_top - hard_ack)
+		return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_sack_overflow);
 
-	if (after(hard_ack, call->tx_hard_ack)) {
+	if (after(hard_ack, call->acks_hard_ack)) {
 		if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
-			rxrpc_end_tx_phase(call, false, "ETA");
-			goto out;
+			rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ack);
+			return;
 		}
 	}
 
 	if (nr_acks > 0) {
-		if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) {
-			rxrpc_proto_abort("XSA", call, 0);
-			goto out;
-		}
-		rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
-				      &summary);
+		if (offset > (int)skb->len - nr_acks)
+			return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_short_sack);
+		rxrpc_input_soft_acks(call, skb->data + offset, first_soft_ack,
+				      nr_acks, &summary);
 	}
 
-	if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
-	    RXRPC_TX_ANNO_LAST &&
+	if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) &&
 	    summary.nr_acks == call->tx_top - hard_ack &&
 	    rxrpc_is_client_call(call))
-		rxrpc_propose_ACK(call, RXRPC_ACK_PING, ack_serial,
-				  false, true,
-				  rxrpc_propose_ack_ping_for_lost_reply);
+		rxrpc_propose_ping(call, ack_serial,
+				   rxrpc_propose_ack_ping_for_lost_reply);
 
 	rxrpc_congestion_management(call, skb, &summary, acked_serial);
-out:
-	spin_unlock(&call->input_lock);
 }
 
 /*
@@ -1032,16 +935,9 @@ out:
 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_ack_summary summary = { 0 };
-	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-
-	_proto("Rx ACKALL %%%u", sp->hdr.serial);
-
-	spin_lock(&call->input_lock);
 
 	if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
-		rxrpc_end_tx_phase(call, false, "ETL");
-
-	spin_unlock(&call->input_lock);
+		rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ackall);
 }
 
 /*
@@ -1050,35 +946,30 @@ static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	__be32 wtmp;
-	u32 abort_code = RX_CALL_DEAD;
 
-	_enter("");
-
-	if (skb->len >= 4 &&
-	    skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
-			  &wtmp, sizeof(wtmp)) >= 0)
-		abort_code = ntohl(wtmp);
-
-	trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code);
-
-	_proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
+	trace_rxrpc_rx_abort(call, sp->hdr.serial, skb->priority);
 
 	rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
-				  abort_code, -ECONNABORTED);
+				  skb->priority, -ECONNABORTED);
 }
 
 /*
  * Process an incoming call packet.
  */
-static void rxrpc_input_call_packet(struct rxrpc_call *call,
-				    struct sk_buff *skb)
+void rxrpc_input_call_packet(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	unsigned long timo;
 
 	_enter("%p,%p", call, skb);
 
+	if (sp->hdr.serviceId != call->dest_srx.srx_service)
+		call->dest_srx.srx_service = sp->hdr.serviceId;
+	if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
+		call->rx_serial = sp->hdr.serial;
+	if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
+		set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
+
 	timo = READ_ONCE(call->next_rx_timo);
 	if (timo) {
 		unsigned long now = jiffies, expect_rx_by;
@@ -1091,37 +982,27 @@ static void rxrpc_input_call_packet(struct rxrpc_call *call,
 
 	switch (sp->hdr.type) {
 	case RXRPC_PACKET_TYPE_DATA:
-		rxrpc_input_data(call, skb);
-		goto no_free;
+		return rxrpc_input_data(call, skb);
 
 	case RXRPC_PACKET_TYPE_ACK:
-		rxrpc_input_ack(call, skb);
-		break;
+		return rxrpc_input_ack(call, skb);
 
 	case RXRPC_PACKET_TYPE_BUSY:
-		_proto("Rx BUSY %%%u", sp->hdr.serial);
-
 		/* Just ignore BUSY packets from the server; the retry and
 		 * lifespan timers will take care of business.  BUSY packets
 		 * from the client don't make sense.
 		 */
-		break;
+		return;
 
 	case RXRPC_PACKET_TYPE_ABORT:
-		rxrpc_input_abort(call, skb);
-		break;
+		return rxrpc_input_abort(call, skb);
 
 	case RXRPC_PACKET_TYPE_ACKALL:
-		rxrpc_input_ackall(call, skb);
-		break;
+		return rxrpc_input_ackall(call, skb);
 
 	default:
 		break;
 	}
-
-	rxrpc_free_skb(skb, rxrpc_skb_freed);
-no_free:
-	_leave("");
 }
 
 /*
@@ -1130,373 +1011,20 @@ no_free:
  *
  * TODO: If callNumber > call_id + 1, renegotiate security.
  */
-static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx,
-					  struct rxrpc_connection *conn,
-					  struct rxrpc_call *call)
+void rxrpc_implicit_end_call(struct rxrpc_call *call, struct sk_buff *skb)
 {
-	switch (READ_ONCE(call->state)) {
+	switch (__rxrpc_call_state(call)) {
 	case RXRPC_CALL_SERVER_AWAIT_ACK:
 		rxrpc_call_completed(call);
 		fallthrough;
 	case RXRPC_CALL_COMPLETE:
 		break;
 	default:
-		if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) {
-			set_bit(RXRPC_CALL_EV_ABORT, &call->events);
-			rxrpc_queue_call(call);
-		}
+		rxrpc_abort_call(call, 0, RX_CALL_DEAD, -ESHUTDOWN,
+				 rxrpc_eproto_improper_term);
 		trace_rxrpc_improper_term(call);
 		break;
 	}
 
-	spin_lock(&rx->incoming_lock);
-	__rxrpc_disconnect_call(conn, call);
-	spin_unlock(&rx->incoming_lock);
-}
-
-/*
- * post connection-level events to the connection
- * - this includes challenges, responses, some aborts and call terminal packet
- *   retransmission.
- */
-static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
-				      struct sk_buff *skb)
-{
-	_enter("%p,%p", conn, skb);
-
-	skb_queue_tail(&conn->rx_queue, skb);
-	rxrpc_queue_conn(conn);
-}
-
-/*
- * post endpoint-level events to the local endpoint
- * - this includes debug and version messages
- */
-static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
-				       struct sk_buff *skb)
-{
-	_enter("%p,%p", local, skb);
-
-	if (rxrpc_get_local_maybe(local)) {
-		skb_queue_tail(&local->event_queue, skb);
-		rxrpc_queue_local(local);
-	} else {
-		rxrpc_free_skb(skb, rxrpc_skb_freed);
-	}
-}
-
-/*
- * put a packet up for transport-level abort
- */
-static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
-{
-	if (rxrpc_get_local_maybe(local)) {
-		skb_queue_tail(&local->reject_queue, skb);
-		rxrpc_queue_local(local);
-	} else {
-		rxrpc_free_skb(skb, rxrpc_skb_freed);
-	}
-}
-
-/*
- * Extract the wire header from a packet and translate the byte order.
- */
-static noinline
-int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
-{
-	struct rxrpc_wire_header whdr;
-
-	/* dig out the RxRPC connection details */
-	if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) {
-		trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
-				      tracepoint_string("bad_hdr"));
-		return -EBADMSG;
-	}
-
-	memset(sp, 0, sizeof(*sp));
-	sp->hdr.epoch		= ntohl(whdr.epoch);
-	sp->hdr.cid		= ntohl(whdr.cid);
-	sp->hdr.callNumber	= ntohl(whdr.callNumber);
-	sp->hdr.seq		= ntohl(whdr.seq);
-	sp->hdr.serial		= ntohl(whdr.serial);
-	sp->hdr.flags		= whdr.flags;
-	sp->hdr.type		= whdr.type;
-	sp->hdr.userStatus	= whdr.userStatus;
-	sp->hdr.securityIndex	= whdr.securityIndex;
-	sp->hdr._rsvd		= ntohs(whdr._rsvd);
-	sp->hdr.serviceId	= ntohs(whdr.serviceId);
-	return 0;
-}
-
-/*
- * handle data received on the local endpoint
- * - may be called in interrupt context
- *
- * [!] Note that as this is called from the encap_rcv hook, the socket is not
- * held locked by the caller and nothing prevents sk_user_data on the UDP from
- * being cleared in the middle of processing this function.
- *
- * Called with the RCU read lock held from the IP layer via UDP.
- */
-int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
-{
-	struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
-	struct rxrpc_connection *conn;
-	struct rxrpc_channel *chan;
-	struct rxrpc_call *call = NULL;
-	struct rxrpc_skb_priv *sp;
-	struct rxrpc_peer *peer = NULL;
-	struct rxrpc_sock *rx = NULL;
-	unsigned int channel;
-
-	_enter("%p", udp_sk);
-
-	if (unlikely(!local)) {
-		kfree_skb(skb);
-		return 0;
-	}
-	if (skb->tstamp == 0)
-		skb->tstamp = ktime_get_real();
-
-	rxrpc_new_skb(skb, rxrpc_skb_received);
-
-	skb_pull(skb, sizeof(struct udphdr));
-
-	/* The UDP protocol already released all skb resources;
-	 * we are free to add our own data there.
-	 */
-	sp = rxrpc_skb(skb);
-
-	/* dig out the RxRPC connection details */
-	if (rxrpc_extract_header(sp, skb) < 0)
-		goto bad_message;
-
-	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
-		static int lose;
-		if ((lose++ & 7) == 7) {
-			trace_rxrpc_rx_lose(sp);
-			rxrpc_free_skb(skb, rxrpc_skb_lost);
-			return 0;
-		}
-	}
-
-	if (skb->tstamp == 0)
-		skb->tstamp = ktime_get_real();
-	trace_rxrpc_rx_packet(sp);
-
-	switch (sp->hdr.type) {
-	case RXRPC_PACKET_TYPE_VERSION:
-		if (rxrpc_to_client(sp))
-			goto discard;
-		rxrpc_post_packet_to_local(local, skb);
-		goto out;
-
-	case RXRPC_PACKET_TYPE_BUSY:
-		if (rxrpc_to_server(sp))
-			goto discard;
-		fallthrough;
-	case RXRPC_PACKET_TYPE_ACK:
-	case RXRPC_PACKET_TYPE_ACKALL:
-		if (sp->hdr.callNumber == 0)
-			goto bad_message;
-		fallthrough;
-	case RXRPC_PACKET_TYPE_ABORT:
-		break;
-
-	case RXRPC_PACKET_TYPE_DATA:
-		if (sp->hdr.callNumber == 0 ||
-		    sp->hdr.seq == 0)
-			goto bad_message;
-		if (!rxrpc_validate_data(skb))
-			goto bad_message;
-
-		/* Unshare the packet so that it can be modified for in-place
-		 * decryption.
-		 */
-		if (sp->hdr.securityIndex != 0) {
-			struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
-			if (!nskb) {
-				rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
-				goto out;
-			}
-
-			if (nskb != skb) {
-				rxrpc_eaten_skb(skb, rxrpc_skb_received);
-				skb = nskb;
-				rxrpc_new_skb(skb, rxrpc_skb_unshared);
-				sp = rxrpc_skb(skb);
-			}
-		}
-		break;
-
-	case RXRPC_PACKET_TYPE_CHALLENGE:
-		if (rxrpc_to_server(sp))
-			goto discard;
-		break;
-	case RXRPC_PACKET_TYPE_RESPONSE:
-		if (rxrpc_to_client(sp))
-			goto discard;
-		break;
-
-		/* Packet types 9-11 should just be ignored. */
-	case RXRPC_PACKET_TYPE_PARAMS:
-	case RXRPC_PACKET_TYPE_10:
-	case RXRPC_PACKET_TYPE_11:
-		goto discard;
-
-	default:
-		_proto("Rx Bad Packet Type %u", sp->hdr.type);
-		goto bad_message;
-	}
-
-	if (sp->hdr.serviceId == 0)
-		goto bad_message;
-
-	if (rxrpc_to_server(sp)) {
-		/* Weed out packets to services we're not offering.  Packets
-		 * that would begin a call are explicitly rejected and the rest
-		 * are just discarded.
-		 */
-		rx = rcu_dereference(local->service);
-		if (!rx || (sp->hdr.serviceId != rx->srx.srx_service &&
-			    sp->hdr.serviceId != rx->second_service)) {
-			if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
-			    sp->hdr.seq == 1)
-				goto unsupported_service;
-			goto discard;
-		}
-	}
-
-	conn = rxrpc_find_connection_rcu(local, skb, &peer);
-	if (conn) {
-		if (sp->hdr.securityIndex != conn->security_ix)
-			goto wrong_security;
-
-		if (sp->hdr.serviceId != conn->service_id) {
-			int old_id;
-
-			if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
-				goto reupgrade;
-			old_id = cmpxchg(&conn->service_id, conn->params.service_id,
-					 sp->hdr.serviceId);
-
-			if (old_id != conn->params.service_id &&
-			    old_id != sp->hdr.serviceId)
-				goto reupgrade;
-		}
-
-		if (sp->hdr.callNumber == 0) {
-			/* Connection-level packet */
-			_debug("CONN %p {%d}", conn, conn->debug_id);
-			rxrpc_post_packet_to_conn(conn, skb);
-			goto out;
-		}
-
-		if ((int)sp->hdr.serial - (int)conn->hi_serial > 0)
-			conn->hi_serial = sp->hdr.serial;
-
-		/* Call-bound packets are routed by connection channel. */
-		channel = sp->hdr.cid & RXRPC_CHANNELMASK;
-		chan = &conn->channels[channel];
-
-		/* Ignore really old calls */
-		if (sp->hdr.callNumber < chan->last_call)
-			goto discard;
-
-		if (sp->hdr.callNumber == chan->last_call) {
-			if (chan->call ||
-			    sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
-				goto discard;
-
-			/* For the previous service call, if completed
-			 * successfully, we discard all further packets.
-			 */
-			if (rxrpc_conn_is_service(conn) &&
-			    chan->last_type == RXRPC_PACKET_TYPE_ACK)
-				goto discard;
-
-			/* But otherwise we need to retransmit the final packet
-			 * from data cached in the connection record.
-			 */
-			if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
-				trace_rxrpc_rx_data(chan->call_debug_id,
-						    sp->hdr.seq,
-						    sp->hdr.serial,
-						    sp->hdr.flags, 0);
-			rxrpc_post_packet_to_conn(conn, skb);
-			goto out;
-		}
-
-		call = rcu_dereference(chan->call);
-
-		if (sp->hdr.callNumber > chan->call_id) {
-			if (rxrpc_to_client(sp))
-				goto reject_packet;
-			if (call)
-				rxrpc_input_implicit_end_call(rx, conn, call);
-			call = NULL;
-		}
-
-		if (call) {
-			if (sp->hdr.serviceId != call->service_id)
-				call->service_id = sp->hdr.serviceId;
-			if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
-				call->rx_serial = sp->hdr.serial;
-			if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
-				set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
-		}
-	}
-
-	if (!call || refcount_read(&call->ref) == 0) {
-		if (rxrpc_to_client(sp) ||
-		    sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
-			goto bad_message;
-		if (sp->hdr.seq != 1)
-			goto discard;
-		call = rxrpc_new_incoming_call(local, rx, skb);
-		if (!call)
-			goto reject_packet;
-	}
-
-	/* Process a call packet; this either discards or passes on the ref
-	 * elsewhere.
-	 */
-	rxrpc_input_call_packet(call, skb);
-	goto out;
-
-discard:
-	rxrpc_free_skb(skb, rxrpc_skb_freed);
-out:
-	trace_rxrpc_rx_done(0, 0);
-	return 0;
-
-wrong_security:
-	trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
-			  RXKADINCONSISTENCY, EBADMSG);
-	skb->priority = RXKADINCONSISTENCY;
-	goto post_abort;
-
-unsupported_service:
-	trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
-			  RX_INVALID_OPERATION, EOPNOTSUPP);
-	skb->priority = RX_INVALID_OPERATION;
-	goto post_abort;
-
-reupgrade:
-	trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
-			  RX_PROTOCOL_ERROR, EBADMSG);
-	goto protocol_error;
-
-bad_message:
-	trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
-			  RX_PROTOCOL_ERROR, EBADMSG);
-protocol_error:
-	skb->priority = RX_PROTOCOL_ERROR;
-post_abort:
-	skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
-reject_packet:
-	trace_rxrpc_rx_done(skb->mark, skb->priority);
-	rxrpc_reject_packet(local, skb);
-	_leave(" [badmsg]");
-	return 0;
+	rxrpc_input_call_event(call, skb);
 }