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>
This commit is contained in:
Gerrit Renker 2008-09-04 07:30:19 +02:00
parent 4861a35443
commit 2faae5587f
2 changed files with 12 additions and 1 deletions

View File

@ -74,6 +74,18 @@ static int dccp_hdlr_seq_win(struct sock *sk, u64 seq_win, bool rx)
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

View File

@ -189,7 +189,6 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
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);