linux/net/dccp
Gerrit Renker b4d4f7c70f [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>
2008-01-28 14:57:51 -08:00
..
ccids [TFRC]: Remove previous loss intervals implementation 2008-01-28 14:57:20 -08:00
ackvec.c [ACKVEC]: Reduce length of identifiers 2008-01-28 14:54:51 -08:00
ackvec.h [ACKVEC]: Reduce length of identifiers 2008-01-28 14:54:51 -08:00
ccid.c [DCCP]: fix theoretical ccids_{read,write}_lock() race 2007-08-13 22:52:09 -07:00
ccid.h [DCCP] ccid: Deprecate ccid_hc_tx_insert_options 2006-12-11 14:34:49 -08:00
dccp.h [DCCP]: Use maximum-RTO backoff from DCCP spec 2008-01-28 14:57:47 -08:00
diag.c [INET]: Let inet_diag and friends autoload 2007-10-22 02:59:54 -07:00
feat.c [DCCP]: fix memory leak and clean up style - dccp_feat_empty_confirm() 2007-08-13 22:52:10 -07:00
feat.h [NET] DCCP: Fix whitespace errors. 2007-02-10 23:19:27 -08:00
input.c [DCCP]: Allow to parse options on Request Sockets 2008-01-28 14:57:50 -08:00
ipv4.c [DCCP]: Allow to parse options on Request Sockets 2008-01-28 14:57:50 -08:00
ipv6.c [DCCP]: Allow to parse options on Request Sockets 2008-01-28 14:57:50 -08:00
ipv6.h Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
Kconfig [DCCP]: Promote CCID2 as default CCID 2008-01-28 14:54:46 -08:00
Makefile [DCCPv6]: Resolve conditional build problem 2006-12-02 21:22:28 -08:00
minisocks.c [DCCP]: Handle timestamps on Request/Response exchange separately 2008-01-28 14:57:51 -08:00
options.c [DCCP]: Handle timestamps on Request/Response exchange separately 2008-01-28 14:57:51 -08:00
output.c [DCCP]: Support for server holding timewait state 2008-01-28 14:57:48 -08:00
probe.c [NET]: Make /proc/net per network namespace 2007-10-10 16:49:06 -07:00
proto.c [DCCP]: Collapse repeated `len' statements into one 2008-01-28 14:57:49 -08:00
sysctl.c [DCCP]: fix link error with !CONFIG_SYSCTL 2007-10-17 19:33:06 -07:00
timer.c [NET]: Convert init_timer into setup_timer 2008-01-28 14:53:35 -08:00