af_rxrpc: Add sysctls for configuring RxRPC parameters
Add sysctls for configuring RxRPC protocol handling, specifically controls on
delays before ack generation, the delay before resending a packet, the maximum
lifetime of a call and the expiration times of calls, connections and
transports that haven't been recently used.
More info added in Documentation/networking/rxrpc.txt.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/ar-ack.c b/net/rxrpc/ar-ack.c
index cd97a0c..732b82f 100644
--- a/net/rxrpc/ar-ack.c
+++ b/net/rxrpc/ar-ack.c
@@ -19,7 +19,29 @@
#include <net/af_rxrpc.h>
#include "ar-internal.h"
-static unsigned int rxrpc_ack_defer = 1;
+/*
+ * How long to wait before scheduling ACK generation after seeing a
+ * packet with RXRPC_REQUEST_ACK set (in jiffies).
+ */
+unsigned rxrpc_requested_ack_delay = 1;
+
+/*
+ * How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
+ *
+ * We use this when we've received new data packets. If those packets aren't
+ * all consumed within this time we will send a DELAY ACK if an ACK was not
+ * requested to let the sender know it doesn't need to resend.
+ */
+unsigned rxrpc_soft_ack_delay = 1 * HZ;
+
+/*
+ * How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
+ *
+ * We use this when we've consumed some previously soft-ACK'd packets when
+ * further packets aren't immediately received to decide when to send an IDLE
+ * ACK let the other end know that it can free up its Tx buffer space.
+ */
+unsigned rxrpc_idle_ack_delay = 1;
static const char *rxrpc_acks(u8 reason)
{
@@ -82,24 +104,23 @@
switch (ack_reason) {
case RXRPC_ACK_DELAY:
_debug("run delay timer");
- call->ack_timer.expires = jiffies + rxrpc_ack_timeout * HZ;
- add_timer(&call->ack_timer);
- return;
+ expiry = rxrpc_soft_ack_delay;
+ goto run_timer;
case RXRPC_ACK_IDLE:
if (!immediate) {
_debug("run defer timer");
- expiry = 1;
+ expiry = rxrpc_idle_ack_delay;
goto run_timer;
}
goto cancel_timer;
case RXRPC_ACK_REQUESTED:
- if (!rxrpc_ack_defer)
+ expiry = rxrpc_requested_ack_delay;
+ if (!expiry)
goto cancel_timer;
if (!immediate || serial == cpu_to_be32(1)) {
_debug("run defer timer");
- expiry = rxrpc_ack_defer;
goto run_timer;
}