Merge remote-tracking branch 'net-next/master' into mac80211-next

Resolve the merge conflict between Felix's/my and Toke's patches
coming into the tree through net and mac80211-next respectively.
Most of Felix's changes go away due to Toke's new infrastructure
work, my patch changes to "goto begin" (the label wasn't there
before) instead of returning NULL so flow control towards drivers
is preserved better.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 432 insertions, 72 deletions

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 75af0bd316c7..3ad9f75031e3 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -37,12 +37,198 @@ static void rxrpc_proto_abort(const char *why,
 }
 
 /*
+ * Do TCP-style congestion management [RFC 5681].
+ */
+static void rxrpc_congestion_management(struct rxrpc_call *call,
+					struct sk_buff *skb,
+					struct rxrpc_ack_summary *summary,
+					rxrpc_serial_t acked_serial)
+{
+	enum rxrpc_congest_change change = rxrpc_cong_no_change;
+	unsigned int cumulative_acks = call->cong_cumul_acks;
+	unsigned int cwnd = call->cong_cwnd;
+	bool resend = false;
+
+	summary->flight_size =
+		(call->tx_top - call->tx_hard_ack) - summary->nr_acks;
+
+	if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) {
+		summary->retrans_timeo = true;
+		call->cong_ssthresh = max_t(unsigned int,
+					    summary->flight_size / 2, 2);
+		cwnd = 1;
+		if (cwnd >= call->cong_ssthresh &&
+		    call->cong_mode == RXRPC_CALL_SLOW_START) {
+			call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+			call->cong_tstamp = skb->tstamp;
+			cumulative_acks = 0;
+		}
+	}
+
+	cumulative_acks += summary->nr_new_acks;
+	cumulative_acks += summary->nr_rot_new_acks;
+	if (cumulative_acks > 255)
+		cumulative_acks = 255;
+
+	summary->mode = call->cong_mode;
+	summary->cwnd = call->cong_cwnd;
+	summary->ssthresh = call->cong_ssthresh;
+	summary->cumulative_acks = cumulative_acks;
+	summary->dup_acks = call->cong_dup_acks;
+
+	switch (call->cong_mode) {
+	case RXRPC_CALL_SLOW_START:
+		if (summary->nr_nacks > 0)
+			goto packet_loss_detected;
+		if (summary->cumulative_acks > 0)
+			cwnd += 1;
+		if (cwnd >= call->cong_ssthresh) {
+			call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+			call->cong_tstamp = skb->tstamp;
+		}
+		goto out;
+
+	case RXRPC_CALL_CONGEST_AVOIDANCE:
+		if (summary->nr_nacks > 0)
+			goto packet_loss_detected;
+
+		/* We analyse the number of packets that get ACK'd per RTT
+		 * period and increase the window if we managed to fill it.
+		 */
+		if (call->peer->rtt_usage == 0)
+			goto out;
+		if (ktime_before(skb->tstamp,
+				 ktime_add_ns(call->cong_tstamp,
+					      call->peer->rtt)))
+			goto out_no_clear_ca;
+		change = rxrpc_cong_rtt_window_end;
+		call->cong_tstamp = skb->tstamp;
+		if (cumulative_acks >= cwnd)
+			cwnd++;
+		goto out;
+
+	case RXRPC_CALL_PACKET_LOSS:
+		if (summary->nr_nacks == 0)
+			goto resume_normality;
+
+		if (summary->new_low_nack) {
+			change = rxrpc_cong_new_low_nack;
+			call->cong_dup_acks = 1;
+			if (call->cong_extra > 1)
+				call->cong_extra = 1;
+			goto send_extra_data;
+		}
+
+		call->cong_dup_acks++;
+		if (call->cong_dup_acks < 3)
+			goto send_extra_data;
+
+		change = rxrpc_cong_begin_retransmission;
+		call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT;
+		call->cong_ssthresh = max_t(unsigned int,
+					    summary->flight_size / 2, 2);
+		cwnd = call->cong_ssthresh + 3;
+		call->cong_extra = 0;
+		call->cong_dup_acks = 0;
+		resend = true;
+		goto out;
+
+	case RXRPC_CALL_FAST_RETRANSMIT:
+		if (!summary->new_low_nack) {
+			if (summary->nr_new_acks == 0)
+				cwnd += 1;
+			call->cong_dup_acks++;
+			if (call->cong_dup_acks == 2) {
+				change = rxrpc_cong_retransmit_again;
+				call->cong_dup_acks = 0;
+				resend = true;
+			}
+		} else {
+			change = rxrpc_cong_progress;
+			cwnd = call->cong_ssthresh;
+			if (summary->nr_nacks == 0)
+				goto resume_normality;
+		}
+		goto out;
+
+	default:
+		BUG();
+		goto out;
+	}
+
+resume_normality:
+	change = rxrpc_cong_cleared_nacks;
+	call->cong_dup_acks = 0;
+	call->cong_extra = 0;
+	call->cong_tstamp = skb->tstamp;
+	if (cwnd < call->cong_ssthresh)
+		call->cong_mode = RXRPC_CALL_SLOW_START;
+	else
+		call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+out:
+	cumulative_acks = 0;
+out_no_clear_ca:
+	if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1)
+		cwnd = RXRPC_RXTX_BUFF_SIZE - 1;
+	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);
+	return;
+
+packet_loss_detected:
+	change = rxrpc_cong_saw_nack;
+	call->cong_mode = RXRPC_CALL_PACKET_LOSS;
+	call->cong_dup_acks = 0;
+	goto send_extra_data;
+
+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) {
+		call->cong_extra++;
+		wake_up(&call->waitq);
+	}
+	goto out_no_clear_ca;
+}
+
+/*
+ * Ping the other end to fill our RTT cache and to retrieve the rwind
+ * and MTU parameters.
+ */
+static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb,
+			    int skew)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	ktime_t now = skb->tstamp;
+
+	if (call->peer->rtt_usage < 3 ||
+	    ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now))
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial,
+				  true, true,
+				  rxrpc_propose_ack_ping_for_params);
+}
+
+/*
  * Apply a hard ACK by advancing the Tx window.
  */
-static void rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to)
+static void rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
+				   struct rxrpc_ack_summary *summary)
 {
 	struct sk_buff *skb, *list = NULL;
 	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);
 
@@ -50,22 +236,31 @@ static void rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to)
 		call->tx_hard_ack++;
 		ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK;
 		skb = call->rxtx_buffer[ix];
-		rxrpc_see_skb(skb);
+		annotation = call->rxtx_annotations[ix];
+		rxrpc_see_skb(skb, rxrpc_skb_tx_rotated);
 		call->rxtx_buffer[ix] = NULL;
 		call->rxtx_annotations[ix] = 0;
 		skb->next = list;
 		list = skb;
+
+		if (annotation & RXRPC_TX_ANNO_LAST)
+			set_bit(RXRPC_CALL_TX_LAST, &call->flags);
+		if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK)
+			summary->nr_rot_new_acks++;
 	}
 
 	spin_unlock(&call->lock);
 
+	trace_rxrpc_transmit(call, (test_bit(RXRPC_CALL_TX_LAST, &call->flags) ?
+				    rxrpc_transmit_rotate_last :
+				    rxrpc_transmit_rotate));
 	wake_up(&call->waitq);
 
 	while (list) {
 		skb = list;
 		list = skb->next;
 		skb->next = NULL;
-		rxrpc_free_skb(skb);
+		rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 	}
 }
 
@@ -75,40 +270,78 @@ static void 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, const char *abort_why)
+static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
+			       const char *abort_why)
 {
-	_enter("");
 
-	switch (call->state) {
-	case RXRPC_CALL_CLIENT_RECV_REPLY:
-		return true;
-	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
-	case RXRPC_CALL_SERVER_AWAIT_ACK:
-		break;
-	default:
-		rxrpc_proto_abort(abort_why, call, call->tx_top);
-		return false;
-	}
-
-	rxrpc_rotate_tx_window(call, call->tx_top);
+	ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
 
 	write_lock(&call->state_lock);
 
 	switch (call->state) {
-	default:
-		break;
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
 	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
-		call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
+		if (reply_begun)
+			call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
+		else
+			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 		break;
+
 	case RXRPC_CALL_SERVER_AWAIT_ACK:
 		__rxrpc_call_completed(call);
 		rxrpc_notify_socket(call);
 		break;
+
+	default:
+		goto bad_state;
 	}
 
 	write_unlock(&call->state_lock);
+	if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) {
+		rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, 0, false, true,
+				  rxrpc_propose_ack_client_tx_end);
+		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;
+}
+
+/*
+ * Begin the reply reception phase of a call.
+ */
+static bool rxrpc_receiving_reply(struct rxrpc_call *call)
+{
+	struct rxrpc_ack_summary summary = { 0 };
+	rxrpc_seq_t top = READ_ONCE(call->tx_top);
+
+	if (call->ackr_reason) {
+		spin_lock_bh(&call->lock);
+		call->ackr_reason = 0;
+		call->resend_at = call->expire_at;
+		call->ack_at = call->expire_at;
+		spin_unlock_bh(&call->lock);
+		rxrpc_set_timer(call, rxrpc_timer_init_for_reply,
+				ktime_get_real());
+	}
+
+	if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags))
+		rxrpc_rotate_tx_window(call, top, &summary);
+	if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
+		rxrpc_proto_abort("TXL", call, top);
+		return false;
+	}
+	if (!rxrpc_end_tx_phase(call, true, "ETD"))
+		return false;
+	call->tx_phase = false;
+	return true;
 }
 
 /*
@@ -126,7 +359,7 @@ static bool rxrpc_end_tx_phase(struct rxrpc_call *call, const char *abort_why)
 static bool rxrpc_validate_jumbo(struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	unsigned int offset = sp->offset;
+	unsigned int offset = sizeof(struct rxrpc_wire_header);
 	unsigned int len = skb->len;
 	int nr_jumbo = 1;
 	u8 flags = sp->hdr.flags;
@@ -187,7 +420,7 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
 			     u16 skew)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	unsigned int offset = sp->offset;
+	unsigned int offset = sizeof(struct rxrpc_wire_header);
 	unsigned int ix;
 	rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
 	rxrpc_seq_t seq = sp->hdr.seq, hard_ack;
@@ -207,8 +440,9 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
 	/* Received data implicitly ACKs all of the request packets we sent
 	 * when we're acting as a client.
 	 */
-	if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY &&
-	    !rxrpc_end_tx_phase(call, "ETD"))
+	if ((call->state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
+	     call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
+	    !rxrpc_receiving_reply(call))
 		return;
 
 	call->ackr_prev_seq = seq;
@@ -238,7 +472,7 @@ next_subpacket:
 		len = RXRPC_JUMBO_DATALEN;
 
 	if (flags & RXRPC_LAST_PACKET) {
-		if (test_and_set_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+		if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
 		    seq != call->rx_top)
 			return rxrpc_proto_abort("LSN", call, seq);
 	} else {
@@ -276,12 +510,26 @@ next_subpacket:
 	 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
 	 * and also rxrpc_fill_out_ack().
 	 */
-	rxrpc_get_skb(skb);
+	rxrpc_get_skb(skb, rxrpc_skb_rx_got);
 	call->rxtx_annotations[ix] = annotation;
 	smp_wmb();
 	call->rxtx_buffer[ix] = skb;
-	if (after(seq, call->rx_top))
+	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;
+		}
+		immediate_ack = true;
+	}
+	if (flags & RXRPC_LAST_PACKET) {
+		set_bit(RXRPC_CALL_RX_LAST, &call->flags);
+		trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
+	} else {
+		trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
+	}
 	queued = true;
 
 	if (after_eq(seq, call->rx_expect_next)) {
@@ -326,7 +574,8 @@ skip:
 ack:
 	if (ack)
 		rxrpc_propose_ACK(call, ack, skew, ack_serial,
-				  immediate_ack, true);
+				  immediate_ack, true,
+				  rxrpc_propose_ack_input_data);
 
 	if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1)
 		rxrpc_notify_socket(call);
@@ -334,6 +583,64 @@ ack:
 }
 
 /*
+ * Process a requested ACK.
+ */
+static void rxrpc_input_requested_ack(struct rxrpc_call *call,
+				      ktime_t resp_time,
+				      rxrpc_serial_t orig_serial,
+				      rxrpc_serial_t ack_serial)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	ktime_t sent_at;
+	int ix;
+
+	for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
+		skb = call->rxtx_buffer[ix];
+		if (!skb)
+			continue;
+
+		sp = rxrpc_skb(skb);
+		if (sp->hdr.serial != orig_serial)
+			continue;
+		smp_rmb();
+		sent_at = skb->tstamp;
+		goto found;
+	}
+	return;
+
+found:
+	rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
+			   orig_serial, ack_serial, sent_at, resp_time);
+}
+
+/*
+ * Process a ping response.
+ */
+static void rxrpc_input_ping_response(struct rxrpc_call *call,
+				      ktime_t resp_time,
+				      rxrpc_serial_t orig_serial,
+				      rxrpc_serial_t ack_serial)
+{
+	rxrpc_serial_t ping_serial;
+	ktime_t ping_time;
+
+	ping_time = call->ackr_ping_time;
+	smp_rmb();
+	ping_serial = call->ackr_ping;
+
+	if (!test_bit(RXRPC_CALL_PINGING, &call->flags) ||
+	    before(orig_serial, ping_serial))
+		return;
+	clear_bit(RXRPC_CALL_PINGING, &call->flags);
+	if (after(orig_serial, ping_serial))
+		return;
+
+	rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response,
+			   orig_serial, ack_serial, ping_time, resp_time);
+}
+
+/*
  * 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,
@@ -352,6 +659,8 @@ static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
 	if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
 		rwind = RXRPC_RXTX_BUFF_SIZE - 1;
 	call->tx_winsize = rwind;
+	if (call->cong_ssthresh > rwind)
+		call->cong_ssthresh = rwind;
 
 	mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
 
@@ -375,31 +684,45 @@ static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
  * the time the ACK was sent.
  */
 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
-				  rxrpc_seq_t seq, int nr_acks)
+				  rxrpc_seq_t seq, int nr_acks,
+				  struct rxrpc_ack_summary *summary)
 {
-	bool resend = false;
 	int ix;
+	u8 annotation, anno_type;
 
 	for (; nr_acks > 0; nr_acks--, seq++) {
 		ix = seq & RXRPC_RXTX_BUFF_MASK;
-		switch (*acks) {
+		annotation = call->rxtx_annotations[ix];
+		anno_type = annotation & RXRPC_TX_ANNO_MASK;
+		annotation &= ~RXRPC_TX_ANNO_MASK;
+		switch (*acks++) {
 		case RXRPC_ACK_TYPE_ACK:
-			call->rxtx_annotations[ix] = RXRPC_TX_ANNO_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 (call->rxtx_annotations[ix] == RXRPC_TX_ANNO_NAK)
+			if (!summary->nr_nacks &&
+			    call->acks_lowest_nak != seq) {
+				call->acks_lowest_nak = seq;
+				summary->new_low_nack = true;
+			}
+			summary->nr_nacks++;
+			if (anno_type == RXRPC_TX_ANNO_NAK)
 				continue;
-			call->rxtx_annotations[ix] = RXRPC_TX_ANNO_NAK;
-			resend = true;
+			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);
 		}
 	}
-
-	if (resend &&
-	    !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
-		rxrpc_queue_call(call);
 }
 
 /*
@@ -415,48 +738,65 @@ static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
 			    u16 skew)
 {
+	struct rxrpc_ack_summary summary = { 0 };
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	union {
 		struct rxrpc_ackpacket ack;
 		struct rxrpc_ackinfo info;
 		u8 acks[RXRPC_MAXACKS];
 	} buf;
+	rxrpc_serial_t acked_serial;
 	rxrpc_seq_t first_soft_ack, hard_ack;
-	int nr_acks, offset;
+	int nr_acks, offset, ioffset;
 
 	_enter("");
 
-	if (skb_copy_bits(skb, sp->offset, &buf.ack, sizeof(buf.ack)) < 0) {
+	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);
 	}
-	sp->offset += sizeof(buf.ack);
+	offset += sizeof(buf.ack);
 
+	acked_serial = ntohl(buf.ack.serial);
 	first_soft_ack = ntohl(buf.ack.firstPacket);
 	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);
+
+	trace_rxrpc_rx_ack(call, first_soft_ack, summary.ack_reason, nr_acks);
 
 	_proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
 	       sp->hdr.serial,
 	       ntohs(buf.ack.maxSkew),
 	       first_soft_ack,
 	       ntohl(buf.ack.previousPacket),
-	       ntohl(buf.ack.serial),
-	       rxrpc_acks(buf.ack.reason),
+	       acked_serial,
+	       rxrpc_ack_names[summary.ack_reason],
 	       buf.ack.nAcks);
 
+	if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
+		rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
+					  sp->hdr.serial);
+	if (buf.ack.reason == RXRPC_ACK_REQUESTED)
+		rxrpc_input_requested_ack(call, skb->tstamp, acked_serial,
+					  sp->hdr.serial);
+
 	if (buf.ack.reason == RXRPC_ACK_PING) {
 		_proto("Rx ACK %%%u PING Request", sp->hdr.serial);
 		rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
-				  skew, sp->hdr.serial, true, true);
+				  skew, sp->hdr.serial, true, true,
+				  rxrpc_propose_ack_respond_to_ping);
 	} else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
 		rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
-				  skew, sp->hdr.serial, true, true);
+				  skew, sp->hdr.serial, true, true,
+				  rxrpc_propose_ack_respond_to_ack);
 	}
 
-	offset = sp->offset + nr_acks + 3;
-	if (skb->len >= offset + sizeof(buf.info)) {
-		if (skb_copy_bits(skb, offset, &buf.info, sizeof(buf.info)) < 0)
+	ioffset = offset + nr_acks + 3;
+	if (skb->len >= ioffset + sizeof(buf.info)) {
+		if (skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0)
 			return rxrpc_proto_abort("XAI", call, 0);
 		rxrpc_input_ackinfo(call, skb, &buf.info);
 	}
@@ -476,34 +816,43 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
 	}
 
 	/* Discard any out-of-order or duplicate ACKs. */
-	if ((int)sp->hdr.serial - (int)call->acks_latest <= 0) {
+	if (before_eq(sp->hdr.serial, call->acks_latest)) {
 		_debug("discard ACK %d <= %d",
 		       sp->hdr.serial, call->acks_latest);
 		return;
 	}
+	call->acks_latest_ts = skb->tstamp;
 	call->acks_latest = sp->hdr.serial;
 
-	if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) &&
-	    hard_ack == call->tx_top) {
-		rxrpc_end_tx_phase(call, "ETA");
-		return;
-	}
-
 	if (before(hard_ack, call->tx_hard_ack) ||
 	    after(hard_ack, call->tx_top))
 		return rxrpc_proto_abort("AKW", call, 0);
+	if (nr_acks > call->tx_top - hard_ack)
+		return rxrpc_proto_abort("AKN", call, 0);
 
 	if (after(hard_ack, call->tx_hard_ack))
-		rxrpc_rotate_tx_window(call, hard_ack);
+		rxrpc_rotate_tx_window(call, hard_ack, &summary);
+
+	if (nr_acks > 0) {
+		if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0)
+			return rxrpc_proto_abort("XSA", call, 0);
+		rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
+				      &summary);
+	}
 
-	if (after(first_soft_ack, call->tx_top))
+	if (test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
+		rxrpc_end_tx_phase(call, false, "ETA");
 		return;
+	}
+
+	if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
+	    RXRPC_TX_ANNO_LAST &&
+	    summary.nr_acks == call->tx_top - hard_ack)
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial,
+				  false, true,
+				  rxrpc_propose_ack_ping_for_lost_reply);
 
-	if (nr_acks > call->tx_top - first_soft_ack + 1)
-		nr_acks = first_soft_ack - call->tx_top + 1;
-	if (skb_copy_bits(skb, sp->offset, buf.acks, nr_acks) < 0)
-		return rxrpc_proto_abort("XSA", call, 0);
-	rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks);
+	return rxrpc_congestion_management(call, skb, &summary, acked_serial);
 }
 
 /*
@@ -511,11 +860,14 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
  */
 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);
 
-	rxrpc_end_tx_phase(call, "ETL");
+	rxrpc_rotate_tx_window(call, call->tx_top, &summary);
+	if (test_bit(RXRPC_CALL_TX_LAST, &call->flags))
+		rxrpc_end_tx_phase(call, false, "ETL");
 }
 
 /*
@@ -530,7 +882,8 @@ static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
 	_enter("");
 
 	if (skb->len >= 4 &&
-	    skb_copy_bits(skb, sp->offset, &wtmp, sizeof(wtmp)) >= 0)
+	    skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+			  &wtmp, sizeof(wtmp)) >= 0)
 		abort_code = ntohl(wtmp);
 
 	_proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
@@ -646,7 +999,6 @@ int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
 	sp->hdr.securityIndex	= whdr.securityIndex;
 	sp->hdr._rsvd		= ntohs(whdr._rsvd);
 	sp->hdr.serviceId	= ntohs(whdr.serviceId);
-	sp->offset = sizeof(whdr);
 	return 0;
 }
 
@@ -681,13 +1033,13 @@ void rxrpc_data_ready(struct sock *udp_sk)
 		return;
 	}
 
-	rxrpc_new_skb(skb);
+	rxrpc_new_skb(skb, rxrpc_skb_rx_received);
 
 	_net("recv skb %p", skb);
 
 	/* we'll probably need to checksum it (didn't call sock_recvmsg) */
 	if (skb_checksum_complete(skb)) {
-		rxrpc_free_skb(skb);
+		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 		__UDP_INC_STATS(&init_net, UDP_MIB_INERRORS, 0);
 		_leave(" [CSUM failed]");
 		return;
@@ -701,12 +1053,19 @@ void rxrpc_data_ready(struct sock *udp_sk)
 	skb_orphan(skb);
 	sp = rxrpc_skb(skb);
 
-	_net("Rx UDP packet from %08x:%04hu",
-	     ntohl(ip_hdr(skb)->saddr), ntohs(udp_hdr(skb)->source));
-
 	/* 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_lose_skb(skb, rxrpc_skb_rx_lost);
+			return;
+		}
+	}
+
 	trace_rxrpc_rx_packet(sp);
 
 	_net("Rx RxRPC %s ep=%x call=%x:%x",
@@ -803,6 +1162,7 @@ void rxrpc_data_ready(struct sock *udp_sk)
 			rcu_read_unlock();
 			goto reject_packet;
 		}
+		rxrpc_send_ping(call, skb, skew);
 	}
 
 	rxrpc_input_call_packet(call, skb, skew);
@@ -811,7 +1171,7 @@ void rxrpc_data_ready(struct sock *udp_sk)
 discard_unlock:
 	rcu_read_unlock();
 discard:
-	rxrpc_free_skb(skb);
+	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 out:
 	trace_rxrpc_rx_done(0, 0);
 	return;