TCPCT API update for 2.6.37

With the recent flurry of messages related to TCPCT, I devoted a nice
snowy Saturday afternoon to updating the socket option code.  Linux is
rather fair behind on TCPCT implementation, so this will help with
future software compatibility.

I'm not on this list, so anybody with comments should CC me.  Thanks.

Use most recently specified symbols of RFC-to-be-6013.

Permit setting either cookie or s_data or both (sequentially).

Allows different s_data limits for SYN and SYN_ACK.

Split the data value from socket option header, saving more than
1K of stack space in the handler by copying long data values
directly from user space into the kref block.

Signed-off-by: William.Allen.Simpson@gmail.com
---
 include/linux/tcp.h |   35 ++++++++++++++++-----
 net/ipv4/tcp.c      |   86 ++++++++++++++++++++++++++++++++++++--------------
 2 files changed, 89 insertions(+), 32 deletions(-)

Circa 15 months ago, my first submitted patch was a sysctl, and there was a
conflict that appeared in a later merge of trees.  Experts, am I in the right
ballpark this time around?

Later, I'll submit the manpage patch to linux-man@vger.kernel.org too.

===

Use most recently specified symbols of RFC-to-be-6013.

Allows different global s_data limits for SYN and SYN_ACK.

Signed-off-by: William.Allen.Simpson@gmail.com
---
 include/net/tcp.h          |    2 ++
 net/ipv4/sysctl_net_ipv4.c |   25 ++++++++++++++++++++++++-
 net/ipv4/tcp_output.c      |   19 +++++++++++++++++--
 3 files changed, 43 insertions(+), 3 deletions(-)