ANDROID: net: ip-sysctl: Document tcp_fwmark_accept

This documentation patch is the part of original tcp_fwmark_accept
implementation, Change-Id: I26bc1eceefd2c588d73b921865ab70e4645ade57
("net: support marking accepting TCP sockets").

The implementation since then got upstreamed, 84f39b08d786
("net: support marking accepting TCP sockets"), without this
documentation part.

Change-Id: I26bc1eceefd2c588d73b921865ab70e4645ade57
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
[AmitP: Refactored the commit log.
        Fixes: 84f39b08d786 ("net: support marking accepting TCP sockets")
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 77f4de59dc9ceb3cdb36692d1ea41e1d861468b0..b0930d4b099b53a361817ce88d9983cb5429c905 100644 (file)
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -608,6 +608,16 @@ tcp_fastopen_blackhole_timeout_sec - INTEGER
        initial value when the blackhole issue goes away.
        By default, it is set to 1hr.
 
+tcp_fwmark_accept - BOOLEAN
+       If set, incoming connections to listening sockets that do not have a
+       socket mark will set the mark of the accepting socket to the fwmark of
+       the incoming SYN packet. This will cause all packets on that connection
+       (starting from the first SYNACK) to be sent with that fwmark. The
+       listening socket's mark is unchanged. Listening sockets that already
+       have a fwmark set via setsockopt(SOL_SOCKET, SO_MARK, ...) are
+       unaffected.
+       Default: 0
+
 tcp_syn_retries - INTEGER
        Number of times initial SYNs for an active TCP connection attempt
        will be retransmitted. Should not be higher than 127. Default value