1 files changed, 156 insertions, 80 deletions

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index ef10fbf71b15..721d847ba92b 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;
@@ -275,7 +275,6 @@ static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
 
 	case RXRPC_CALL_SERVER_AWAIT_ACK:
 		__rxrpc_call_completed(call);
-		rxrpc_notify_socket(call);
 		state = call->state;
 		break;
 
@@ -413,8 +412,8 @@ 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;
-	unsigned int j, nr_subpackets;
-	rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
+	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;
@@ -431,7 +430,7 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 		return;
 	}
 
-	if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) {
+	if (state == RXRPC_CALL_SERVER_RECV_REQUEST) {
 		unsigned long timo = READ_ONCE(call->next_req_timo);
 		unsigned long now, expect_req_by;
 
@@ -454,7 +453,6 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 	    !rxrpc_receiving_reply(call))
 		goto unlock;
 
-	call->ackr_prev_seq = seq0;
 	hard_ack = READ_ONCE(call->rx_hard_ack);
 
 	nr_subpackets = sp->nr_subpackets;
@@ -535,6 +533,9 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 			ack_serial = serial;
 		}
 
+		if (after(seq0, call->ackr_highest_seq))
+			call->ackr_highest_seq = seq0;
+
 		/* 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
@@ -568,6 +569,8 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 			sp = NULL;
 		}
 
+		nr_unacked++;
+
 		if (last) {
 			set_bit(RXRPC_CALL_RX_LAST, &call->flags);
 			if (!ack) {
@@ -587,9 +590,14 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 			}
 			call->rx_expect_next = seq + 1;
 		}
+		if (!ack)
+			ack_serial = serial;
 	}
 
 ack:
+	if (atomic_add_return(nr_unacked, &call->ackr_nr_unacked) > 2 && !ack)
+		ack = RXRPC_ACK_IDLE;
+
 	if (ack)
 		rxrpc_propose_ACK(call, ack, ack_serial,
 				  immediate_ack, true,
@@ -609,36 +617,57 @@ unlock:
 }
 
 /*
- * Process a requested ACK.
+ * See if there's a cached RTT probe to complete.
  */
-static void rxrpc_input_requested_ack(struct rxrpc_call *call,
-				      ktime_t resp_time,
-				      rxrpc_serial_t orig_serial,
-				      rxrpc_serial_t ack_serial)
+static void rxrpc_complete_rtt_probe(struct rxrpc_call *call,
+				     ktime_t resp_time,
+				     rxrpc_serial_t acked_serial,
+				     rxrpc_serial_t ack_serial,
+				     enum rxrpc_rtt_rx_trace type)
 {
-	struct rxrpc_skb_priv *sp;
-	struct sk_buff *skb;
+	rxrpc_serial_t orig_serial;
+	unsigned long avail;
 	ktime_t sent_at;
-	int ix;
+	bool matched = false;
+	int i;
 
-	for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
-		skb = call->rxtx_buffer[ix];
-		if (!skb)
-			continue;
+	avail = READ_ONCE(call->rtt_avail);
+	smp_rmb(); /* Read avail bits before accessing data. */
 
-		sent_at = skb->tstamp;
-		smp_rmb(); /* Read timestamp before serial. */
-		sp = rxrpc_skb(skb);
-		if (sp->hdr.serial != orig_serial)
+	for (i = 0; i < ARRAY_SIZE(call->rtt_serial); i++) {
+		if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail))
 			continue;
-		goto found;
-	}
 
-	return;
+		sent_at = call->rtt_sent_at[i];
+		orig_serial = call->rtt_serial[i];
+
+		if (orig_serial == acked_serial) {
+			clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+			smp_mb(); /* Read data before setting avail bit */
+			set_bit(i, &call->rtt_avail);
+			if (type != rxrpc_rtt_rx_cancel)
+				rxrpc_peer_add_rtt(call, type, i, acked_serial, ack_serial,
+						   sent_at, resp_time);
+			else
+				trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_cancel, i,
+						   orig_serial, acked_serial, 0, 0);
+			matched = true;
+		}
 
-found:
-	rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
-			   orig_serial, ack_serial, sent_at, resp_time);
+		/* If a later serial is being acked, then mark this slot as
+		 * being available.
+		 */
+		if (after(acked_serial, orig_serial)) {
+			trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_obsolete, i,
+					   orig_serial, acked_serial, 0, 0);
+			clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+			smp_wmb();
+			set_bit(i, &call->rtt_avail);
+		}
+	}
+
+	if (!matched)
+		trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_lost, 9, 0, acked_serial, 0, 0);
 }
 
 /*
@@ -683,27 +712,11 @@ static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call)
  */
 static void rxrpc_input_ping_response(struct rxrpc_call *call,
 				      ktime_t resp_time,
-				      rxrpc_serial_t orig_serial,
+				      rxrpc_serial_t acked_serial,
 				      rxrpc_serial_t ack_serial)
 {
-	rxrpc_serial_t ping_serial;
-	ktime_t ping_time;
-
-	ping_time = call->ping_time;
-	smp_rmb();
-	ping_serial = READ_ONCE(call->ping_serial);
-
-	if (orig_serial == call->acks_lost_ping)
+	if (acked_serial == call->acks_lost_ping)
 		rxrpc_input_check_for_lost_ack(call);
-
-	if (before(orig_serial, ping_serial) ||
-	    !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags))
-		return;
-	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);
 }
 
 /*
@@ -723,13 +736,12 @@ 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;
 	}
 
@@ -803,6 +815,30 @@ 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->acks_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->acks_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
@@ -821,7 +857,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 		struct rxrpc_ackinfo info;
 		u8 acks[RXRPC_MAXACKS];
 	} buf;
-	rxrpc_serial_t acked_serial;
+	rxrpc_serial_t ack_serial, acked_serial;
 	rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
 	int nr_acks, offset, ioffset;
 
@@ -834,6 +870,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 	}
 	offset += sizeof(buf.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);
@@ -842,32 +879,73 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
 	summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
 			      buf.ack.reason : RXRPC_ACK__INVALID);
 
-	trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial,
+	trace_rxrpc_rx_ack(call, ack_serial, acked_serial,
 			   first_soft_ack, prev_pkt,
 			   summary.ack_reason, nr_acks);
 
-	if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
+	switch (buf.ack.reason) {
+	case 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);
+					  ack_serial);
+		rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
+					 rxrpc_rtt_rx_ping_response);
+		break;
+	case RXRPC_ACK_REQUESTED:
+		rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
+					 rxrpc_rtt_rx_requested_ack);
+		break;
+	default:
+		if (acked_serial != 0)
+			rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
+						 rxrpc_rtt_rx_cancel);
+		break;
+	}
 
 	if (buf.ack.reason == RXRPC_ACK_PING) {
-		_proto("Rx ACK %%%u PING Request", sp->hdr.serial);
+		_proto("Rx ACK %%%u PING Request", ack_serial);
 		rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
-				  sp->hdr.serial, true, true,
+				  ack_serial, true, true,
 				  rxrpc_propose_ack_respond_to_ping);
 	} else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
 		rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
-				  sp->hdr.serial, true, true,
+				  ack_serial, true, true,
 				  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) &&
+	    first_soft_ack == 1 &&
+	    prev_pkt == 0 &&
+	    rxrpc_is_client_call(call)) {
+		rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
+					  0, -ENETRESET);
+		return;
+	}
+
+	/* If we get an OUT_OF_SEQUENCE ACK from the server, that can also
+	 * 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) &&
+	    first_soft_ack == 1 &&
+	    prev_pkt == 0 &&
+	    call->tx_hard_ack == 0 &&
+	    rxrpc_is_client_call(call)) {
+		rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
+					  0, -ENETRESET);
+		return;
+	}
+
 	/* 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, ack_serial,
+					   first_soft_ack, call->acks_first_seq,
+					   prev_pkt, call->acks_prev_seq);
 		return;
+	}
 
 	buf.info.rxMTU = 0;
 	ioffset = offset + nr_acks + 3;
@@ -878,14 +956,16 @@ 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, 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_latest = sp->hdr.serial;
 
-	call->ackr_first_seq = first_soft_ack;
-	call->ackr_prev_seq = prev_pkt;
+	call->acks_first_seq = first_soft_ack;
+	call->acks_prev_seq = prev_pkt;
 
 	/* Parse rwind and mtu sizes if provided. */
 	if (buf.info.rxMTU)
@@ -937,7 +1017,7 @@ 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, sp->hdr.serial,
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, ack_serial,
 				  false, true,
 				  rxrpc_propose_ack_ping_for_lost_reply);
 
@@ -984,9 +1064,8 @@ static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
 
 	_proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
 
-	if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
-				      abort_code, -ECONNABORTED))
-		rxrpc_notify_socket(call);
+	rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
+				  abort_code, -ECONNABORTED);
 }
 
 /*
@@ -1058,7 +1137,7 @@ static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx,
 	switch (READ_ONCE(call->state)) {
 	case RXRPC_CALL_SERVER_AWAIT_ACK:
 		rxrpc_call_completed(call);
-		/* Fall through */
+		fallthrough;
 	case RXRPC_CALL_COMPLETE:
 		break;
 	default:
@@ -1073,7 +1152,6 @@ static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx,
 	spin_lock(&rx->incoming_lock);
 	__rxrpc_disconnect_call(conn, call);
 	spin_unlock(&rx->incoming_lock);
-	rxrpc_notify_socket(call);
 }
 
 /*
@@ -1112,8 +1190,6 @@ static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
  */
 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
 {
-	CHECK_SLAB_OKAY(&local->usage);
-
 	if (rxrpc_get_local_maybe(local)) {
 		skb_queue_tail(&local->reject_queue, skb);
 		rxrpc_queue_local(local);
@@ -1218,12 +1294,12 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
 	case RXRPC_PACKET_TYPE_BUSY:
 		if (rxrpc_to_server(sp))
 			goto discard;
-		/* Fall through */
+		fallthrough;
 	case RXRPC_PACKET_TYPE_ACK:
 	case RXRPC_PACKET_TYPE_ACKALL:
 		if (sp->hdr.callNumber == 0)
 			goto bad_message;
-		/* Fall through */
+		fallthrough;
 	case RXRPC_PACKET_TYPE_ABORT:
 		break;
 
@@ -1371,7 +1447,7 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
 		}
 	}
 
-	if (!call || atomic_read(&call->usage) == 0) {
+	if (!call || refcount_read(&call->ref) == 0) {
 		if (rxrpc_to_client(sp) ||
 		    sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
 			goto bad_message;