msm: Create shadow files under /sys/kernel/ipv4

The TCP delayed ack parameters can be configured from user space
application which runs with non-root credentials and does not have
direct write access to /proc entries. This commit creates shadow
files under /sys/kernel/ipv4 which maps to /proc/sys/net/ipv4.

CRs-Fixed: 628139
Change-Id: If9f5e8f1f5f31c39090555b7b0c40efcdf6ccd08
Signed-off-by: Ravi Joshi <ravij@codeaurora.org>
Merge branch 'cm-11.0-wip' into cm-11.0
tcp: RFC2988bis + taking RTT sample from 3WHS for the passive open side

This patch lowers the default initRTO from 3secs to 1sec per
RFC2988bis. It falls back to 3secs if the SYN or SYN-ACK packet
has been retransmitted, AND the TCP timestamp option is not on.

It also adds support to take RTT sample during 3WHS on the passive
open side, just like its active open counterpart, and uses it, if
valid, to seed the initRTO for the data transmission phase.

The patch also resets ssthresh to its initial default at the
beginning of the data transmission phase, and reduces cwnd to 1 if
there has been MORE THAN ONE retransmission during 3WHS per RFC5681.

Signed-off-by: H.K. Jerry Chu <hkchu@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
WLAN subsystem: Sysctl support for key TCP/IP parameters

It has been observed that default values for some of key tcp/ip
parameters are affecting the tput/performance of the system. Hence
extending configuration capabilities to TCP/Ip stack through
sysctl interface.

Change-Id: I0c99d5b50cbe0d6496e40d391eacc12b0c62dbed
CRs-Fixed: 507581
Signed-off-by: Mahesh A Saptasagar <msapta@codeaurora.org>
Merge branch 'cm-11.0-wip' into cm-11.0