1 files changed, 55 insertions, 58 deletions

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index ee95d1cd1cdf..5df738d527c9 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -91,11 +91,11 @@ static void rxrpc_congestion_management(struct rxrpc_call *call,
 		/* 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)
+		if (call->peer->rtt_count == 0)
 			goto out;
 		if (ktime_before(skb->tstamp,
-				 ktime_add_ns(call->cong_tstamp,
-					      call->peer->rtt)))
+				 ktime_add_us(call->cong_tstamp,
+					      call->peer->srtt_us >> 3)))
 			goto out_no_clear_ca;
 		change = rxrpc_cong_rtt_window_end;
 		call->cong_tstamp = skb->tstamp;
@@ -193,23 +193,6 @@ send_extra_data:
 }
 
 /*
- * 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 bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
@@ -419,8 +402,7 @@ static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
 /*
  * Process a DATA packet, adding the packet to the Rx ring.
  */
-static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
-			     u16 skew)
+static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	enum rxrpc_call_state state;
@@ -600,18 +582,16 @@ skip:
 
 ack:
 	if (ack)
-		rxrpc_propose_ACK(call, ack, skew, ack_serial,
+		rxrpc_propose_ACK(call, ack, ack_serial,
 				  immediate_ack, true,
 				  rxrpc_propose_ack_input_data);
 	else
-		rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, skew, serial,
+		rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial,
 				  false, true,
 				  rxrpc_propose_ack_input_data);
 
-	if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1) {
-		trace_rxrpc_notify_socket(call->debug_id, serial);
-		rxrpc_notify_socket(call);
-	}
+	trace_rxrpc_notify_socket(call->debug_id, serial);
+	rxrpc_notify_socket(call);
 
 unlock:
 	spin_unlock(&call->input_lock);
@@ -733,13 +713,12 @@ static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
 	       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 (call->tx_winsize != rwind) {
-		if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
-			rwind = RXRPC_RXTX_BUFF_SIZE - 1;
 		if (rwind > call->tx_winsize)
 			wake = true;
-		trace_rxrpc_rx_rwind_change(call, sp->hdr.serial,
-					    ntohl(ackinfo->rwind), wake);
+		trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake);
 		call->tx_winsize = rwind;
 	}
 
@@ -813,6 +792,30 @@ static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
 }
 
 /*
+ * Return true if the ACK is valid - ie. it doesn't appear to have regressed
+ * with respect to the ack state conveyed by preceding ACKs.
+ */
+static bool rxrpc_is_ack_valid(struct rxrpc_call *call,
+			       rxrpc_seq_t first_pkt, rxrpc_seq_t prev_pkt)
+{
+	rxrpc_seq_t base = READ_ONCE(call->ackr_first_seq);
+
+	if (after(first_pkt, base))
+		return true; /* The window advanced */
+
+	if (before(first_pkt, base))
+		return false; /* firstPacket regressed */
+
+	if (after_eq(prev_pkt, call->ackr_prev_seq))
+		return true; /* previousPacket hasn't regressed. */
+
+	/* Some rx implementations put a serial number in previousPacket. */
+	if (after_eq(prev_pkt, base + call->tx_winsize))
+		return false;
+	return true;
+}
+
+/*
  * Process an ACK packet.
  *
  * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
@@ -822,8 +825,7 @@ static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
  * soft-ACK means that the packet may be discarded and retransmission
  * requested.  A phase is complete when all packets are hard-ACK'd.
  */
-static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
-			    u16 skew)
+static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 {
 	struct rxrpc_ack_summary summary = { 0 };
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
@@ -867,18 +869,21 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
 	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,
+				  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,
+				  sp->hdr.serial, true, true,
 				  rxrpc_propose_ack_respond_to_ack);
 	}
 
 	/* Discard any out-of-order or duplicate ACKs (outside lock). */
-	if (before(first_soft_ack, call->ackr_first_seq) ||
-	    before(prev_pkt, call->ackr_prev_seq))
+	if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
+		trace_rxrpc_rx_discard_ack(call->debug_id, sp->hdr.serial,
+					   first_soft_ack, call->ackr_first_seq,
+					   prev_pkt, call->ackr_prev_seq);
 		return;
+	}
 
 	buf.info.rxMTU = 0;
 	ioffset = offset + nr_acks + 3;
@@ -889,11 +894,13 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
 	spin_lock(&call->input_lock);
 
 	/* Discard any out-of-order or duplicate ACKs (inside lock). */
-	if (before(first_soft_ack, call->ackr_first_seq) ||
-	    before(prev_pkt, call->ackr_prev_seq))
+	if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
+		trace_rxrpc_rx_discard_ack(call->debug_id, sp->hdr.serial,
+					   first_soft_ack, call->ackr_first_seq,
+					   prev_pkt, call->ackr_prev_seq);
 		goto out;
+	}
 	call->acks_latest_ts = skb->tstamp;
-	call->acks_latest = sp->hdr.serial;
 
 	call->ackr_first_seq = first_soft_ack;
 	call->ackr_prev_seq = prev_pkt;
@@ -948,7 +955,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
 	    RXRPC_TX_ANNO_LAST &&
 	    summary.nr_acks == call->tx_top - hard_ack &&
 	    rxrpc_is_client_call(call))
-		rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial,
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial,
 				  false, true,
 				  rxrpc_propose_ack_ping_for_lost_reply);
 
@@ -1004,7 +1011,7 @@ static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
  * Process an incoming call packet.
  */
 static void rxrpc_input_call_packet(struct rxrpc_call *call,
-				    struct sk_buff *skb, u16 skew)
+				    struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	unsigned long timo;
@@ -1023,11 +1030,11 @@ static void rxrpc_input_call_packet(struct rxrpc_call *call,
 
 	switch (sp->hdr.type) {
 	case RXRPC_PACKET_TYPE_DATA:
-		rxrpc_input_data(call, skb, skew);
+		rxrpc_input_data(call, skb);
 		break;
 
 	case RXRPC_PACKET_TYPE_ACK:
-		rxrpc_input_ack(call, skb, skew);
+		rxrpc_input_ack(call, skb);
 		break;
 
 	case RXRPC_PACKET_TYPE_BUSY:
@@ -1181,7 +1188,6 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
 	struct rxrpc_peer *peer = NULL;
 	struct rxrpc_sock *rx = NULL;
 	unsigned int channel;
-	int skew = 0;
 
 	_enter("%p", udp_sk);
 
@@ -1309,15 +1315,8 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
 			goto out;
 		}
 
-		/* Note the serial number skew here */
-		skew = (int)sp->hdr.serial - (int)conn->hi_serial;
-		if (skew >= 0) {
-			if (skew > 0)
-				conn->hi_serial = sp->hdr.serial;
-		} else {
-			skew = -skew;
-			skew = min(skew, 65535);
-		}
+		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;
@@ -1380,11 +1379,9 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
 		call = rxrpc_new_incoming_call(local, rx, skb);
 		if (!call)
 			goto reject_packet;
-		rxrpc_send_ping(call, skb, skew);
-		mutex_unlock(&call->user_mutex);
 	}
 
-	rxrpc_input_call_packet(call, skb, skew);
+	rxrpc_input_call_packet(call, skb);
 	goto discard;
 
 discard: