dccp ccid-2: Use feature-negotiation to report Ack Ratio changes
This uses the new feature-negotiation framework to signal Ack Ratio changes,
as required by RFC 4341, sec. 6.1.2.
This raises some problems for CCID-2 since it can at the moment not cope
gracefully with Ack Ratio of e.g. 2. A FIXME has thus been added which
reverts to the existing policy of bypassing the Ack Ratio sysctl.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
diff --git a/net/dccp/feat.c b/net/dccp/feat.c
index c847c80..f94c7c9 100644
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -74,6 +74,18 @@
static int dccp_hdlr_ack_ratio(struct sock *sk, u64 ratio, bool rx)
{
+#ifndef __CCID2_COPES_GRACEFULLY_WITH_DYNAMIC_ACK_RATIO_UPDATES__
+ /*
+ * FIXME: This is required until several problems in the CCID-2 code are
+ * resolved. The CCID-2 code currently does not cope well; using dynamic
+ * Ack Ratios greater than 1 caused instabilities. These were manifest
+ * in hangups and long RTO timeouts (1...3 seconds). Until this has been
+ * stabilised, it is safer not to activate dynamic Ack Ratio changes.
+ */
+ dccp_pr_debug("Not changing %s Ack Ratio from 1 to %u\n",
+ rx ? "RX" : "TX", (u16)ratio);
+ ratio = 1;
+#endif
if (rx)
dccp_sk(sk)->dccps_r_ack_ratio = ratio;
else
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 392a5d8..11905e0 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -189,7 +189,6 @@
dp->dccps_rate_last = jiffies;
dp->dccps_role = DCCP_ROLE_UNDEFINED;
dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
- dp->dccps_l_ack_ratio = dp->dccps_r_ack_ratio = 1;
dccp_init_xmit_timers(sk);