freebsd-nq/sys/dev/cxgbe
Gleb Smirnoff 0c39d38d21 Historically we have two fields in tcpcb to describe sender MSS: t_maxopd,
and t_maxseg. This dualism emerged with T/TCP, but was not properly cleaned
up after T/TCP removal. After all permutations over the years the result is
that t_maxopd stores a minimum of peer offered MSS and MTU reduced by minimum
protocol header. And t_maxseg stores (t_maxopd - TCPOLEN_TSTAMP_APPA) if
timestamps are in action, or is equal to t_maxopd otherwise. That's a very
rough estimate of MSS reduced by options length. Throughout the code it
was used in places, where preciseness was not important, like cwnd or
ssthresh calculations.

With this change:

- t_maxopd goes away.
- t_maxseg now stores MSS not adjusted by options.
- new function tcp_maxseg() is provided, that calculates MSS reduced by
  options length. The functions gives a better estimate, since it takes
  into account SACK state as well.

Reviewed by:	jtl
Differential Revision:	https://reviews.freebsd.org/D3593
2016-01-07 00:14:42 +00:00
..
common Add support for configuring additional virtual interfaces (VIs) on a port. 2015-12-03 00:02:01 +00:00
cxgbei cxgbei: Hardware accelerated iSCSI target and initiator for TOE capable 2015-12-26 06:05:21 +00:00
firmware cxgbe/t4_tom: add a knob to the default configuration file to tune 2015-11-10 02:29:19 +00:00
iw_cxgbe iw_cxgbe: Shut down the socket but do not close the fd in case of error. 2016-01-05 01:32:40 +00:00
tom Historically we have two fields in tcpcb to describe sender MSS: t_maxopd, 2016-01-07 00:14:42 +00:00
adapter.h cxgbe(4): Updates to the base NIC driver and t4_tom to support the iSCSI 2015-12-26 00:26:02 +00:00
if_cxl.c cxgbe(4): Add a minimal if_cxl module that pulls in the real driver as 2015-02-06 01:10:04 +00:00
offload.h cxgbe(4): Updates to the base NIC driver and t4_tom to support the iSCSI 2015-12-26 00:26:02 +00:00
osdep.h Add hooks in base cxgbe(4) for the iWARP upper-layer driver. Update a 2013-08-28 20:45:45 +00:00
t4_ioctl.h cxgbe(4): T4_SET_SCHED_CLASS and T4_SET_SCHED_QUEUE ioctls to program 2013-12-03 18:34:52 +00:00
t4_l2t.c Revert r279934, r279938; this is going to be fixed in sbuf instead. 2015-03-14 13:04:39 +00:00
t4_l2t.h
t4_main.c cxgbe(4): Updates to the base NIC driver and t4_tom to support the iSCSI 2015-12-26 00:26:02 +00:00
t4_mp_ring.c Allow cxgbe(4) to be built on i386. Driver attach will succeed only on a subset 2015-01-16 01:32:40 +00:00
t4_mp_ring.h cxgbe(4): major tx rework. 2014-12-31 23:19:16 +00:00
t4_netmap.c Add support for configuring additional virtual interfaces (VIs) on a port. 2015-12-03 00:02:01 +00:00
t4_sge.c Add support for configuring additional virtual interfaces (VIs) on a port. 2015-12-03 00:02:01 +00:00
t4_tracer.c cxgbe(4): Remove stray if_up from the code that creates the tracing ifnet. 2014-05-23 01:45:44 +00:00