rxrpc: Correctly initialise, limit and transmit call->rx_winsize

call->rx_winsize should be initialised to the sysctl setting and the sysctl
setting should be limited to the maximum we want to permit.  Further, we
need to place this in the ACK info instead of the sysctl setting.

Furthermore, discard the idea of accepting the subpackets of a jumbo packet
that lie beyond the receive window when the first packet of the jumbo is
within the window.  Just discard the excess subpackets instead.  This
allows the receive window to be opened up right to the buffer size less one
for the dead slot.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 16 insertions, 7 deletions

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 8e529afcd6c1..75af0bd316c7 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -164,7 +164,7 @@ protocol_error:
  * (that information is encoded in the ACK packet).
  */
 static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
-				 u8 annotation, bool *_jumbo_dup)
+				 u8 annotation, bool *_jumbo_bad)
 {
 	/* Discard normal packets that are duplicates. */
 	if (annotation == 0)
@@ -174,9 +174,9 @@ static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
 	 * more partially duplicate jumbo packets, we refuse to take any more
 	 * jumbos for this call.
 	 */
-	if (!*_jumbo_dup) {
-		call->nr_jumbo_dup++;
-		*_jumbo_dup = true;
+	if (!*_jumbo_bad) {
+		call->nr_jumbo_bad++;
+		*_jumbo_bad = true;
 	}
 }
 
@@ -191,7 +191,7 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
 	unsigned int ix;
 	rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
 	rxrpc_seq_t seq = sp->hdr.seq, hard_ack;
-	bool immediate_ack = false, jumbo_dup = false, queued;
+	bool immediate_ack = false, jumbo_bad = false, queued;
 	u16 len;
 	u8 ack = 0, flags, annotation = 0;
 
@@ -222,7 +222,7 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
 
 	flags = sp->hdr.flags;
 	if (flags & RXRPC_JUMBO_PACKET) {
-		if (call->nr_jumbo_dup > 3) {
+		if (call->nr_jumbo_bad > 3) {
 			ack = RXRPC_ACK_NOSPACE;
 			ack_serial = serial;
 			goto ack;
@@ -259,7 +259,7 @@ next_subpacket:
 	}
 
 	if (call->rxtx_buffer[ix]) {
-		rxrpc_input_dup_data(call, seq, annotation, &jumbo_dup);
+		rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad);
 		if (ack != RXRPC_ACK_DUPLICATE) {
 			ack = RXRPC_ACK_DUPLICATE;
 			ack_serial = serial;
@@ -304,6 +304,15 @@ skip:
 		annotation++;
 		if (flags & RXRPC_JUMBO_PACKET)
 			annotation |= RXRPC_RX_ANNO_JLAST;
+		if (after(seq, hard_ack + call->rx_winsize)) {
+			ack = RXRPC_ACK_EXCEEDS_WINDOW;
+			ack_serial = serial;
+			if (!jumbo_bad) {
+				call->nr_jumbo_bad++;
+				jumbo_bad = true;
+			}
+			goto ack;
+		}
 
 		_proto("Rx DATA Jumbo %%%u", serial);
 		goto next_subpacket;