diff options
author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2007-12-13 12:37:19 -0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2008-01-28 14:57:51 -0800 |
commit | b4d4f7c70fd3361c6c889752e08ea9be304cf5f4 (patch) | |
tree | b84c712184dfcdde4b68980f4eff21bcaefbfcf3 /net/dccp/minisocks.c | |
parent | 8109616e2ef978d142ea45850efd4f102b9bdce4 (diff) |
[DCCP]: Handle timestamps on Request/Response exchange separately
In DCCP, timestamps can occur on packets anytime, CCID3 uses a timestamp(/echo) on the Request/Response
exchange. This patch addresses the following situation:
* timestamps are recorded on the listening socket;
* Responses are sent from dccp_request_sockets;
* suppose two connections reach the listening socket with very small time in between:
* the first timestamp value gets overwritten by the second connection request.
This is not really good, so this patch separates timestamps into
* those which are received by the server during the initial handshake (on dccp_request_sock);
* those which are received by the client or the client after connection establishment.
As before, a timestamp of 0 is regarded as indicating that no (meaningful) timestamp has been
received (in addition, a warning message is printed if hosts send 0-valued timestamps).
The timestamp-echoing now works as follows:
* when a timestamp is present on the initial Request, it is placed into dreq, due to the
call to dccp_parse_options in dccp_v{4,6}_conn_request;
* when a timestamp is present on the Ack leading from RESPOND => OPEN, it is copied over
from the request_sock into the child cocket in dccp_create_openreq_child;
* timestamps received on an (established) dccp_sock are treated as before.
Since Elapsed Time is measured in hundredths of milliseconds (13.2), the new dccp_timestamp()
function is used, as it is expected that the time between receiving the timestamp and
sending the timestamp echo will be very small against the wrap-around time. As a byproduct,
this allows smaller timestamping-time fields.
Furthermore, inserting the Timestamp Echo option has been taken out of the block starting with
'!dccp_packet_without_ack()', since Timestamp Echo can be carried on any packet (5.8 and 13.3).
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp/minisocks.c')
-rw-r--r-- | net/dccp/minisocks.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c index b1d5da61f6af..027d1814e1ab 100644 --- a/net/dccp/minisocks.c +++ b/net/dccp/minisocks.c @@ -117,11 +117,13 @@ struct sock *dccp_create_openreq_child(struct sock *sk, struct dccp_sock *newdp = dccp_sk(newsk); struct dccp_minisock *newdmsk = dccp_msk(newsk); - newdp->dccps_role = DCCP_ROLE_SERVER; - newdp->dccps_hc_rx_ackvec = NULL; - newdp->dccps_service_list = NULL; - newdp->dccps_service = dreq->dreq_service; - newicsk->icsk_rto = DCCP_TIMEOUT_INIT; + newdp->dccps_role = DCCP_ROLE_SERVER; + newdp->dccps_hc_rx_ackvec = NULL; + newdp->dccps_service_list = NULL; + newdp->dccps_service = dreq->dreq_service; + newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo; + newdp->dccps_timestamp_time = dreq->dreq_timestamp_time; + newicsk->icsk_rto = DCCP_TIMEOUT_INIT; if (dccp_feat_clone(sk, newsk)) goto out_free; @@ -303,9 +305,12 @@ EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack); void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb) { - inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport; - inet_rsk(req)->acked = 0; - req->rcv_wnd = sysctl_dccp_feat_sequence_window; + struct dccp_request_sock *dreq = dccp_rsk(req); + + inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport; + inet_rsk(req)->acked = 0; + req->rcv_wnd = sysctl_dccp_feat_sequence_window; + dreq->dreq_timestamp_echo = 0; } EXPORT_SYMBOL_GPL(dccp_reqsk_init); |