From b4d4f7c70fd3361c6c889752e08ea9be304cf5f4 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 13 Dec 2007 12:37:19 -0200 Subject: [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 Acked-by: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- net/dccp/minisocks.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'net/dccp/minisocks.c') diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c index b1d5da6..027d181 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); -- cgit v1.1