Documentation: Describe net.ipv4.tcp_reflect_tos.

The tcp_reflect_tos option was introduced in Linux 5.10 but was still
undocumented.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 3c39776728b9fdc445190f6d8cabdeb8f5c4b056..56cd4ea059b2a33cde01d8db598b160762db1478 100644 (file)
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -636,6 +636,16 @@ tcp_recovery - INTEGER
 
        Default: 0x1
 
+tcp_reflect_tos - BOOLEAN
+       For listening sockets, reuse the DSCP value of the initial SYN message
+       for outgoing packets. This allows to have both directions of a TCP
+       stream to use the same DSCP value, assuming DSCP remains unchanged for
+       the lifetime of the connection.
+
+       This options affects both IPv4 and IPv6.
+
+       Default: 0 (disabled)
+
 tcp_reordering - INTEGER
        Initial reordering level of packets in a TCP stream.
        TCP stack can then dynamically adjust flow reordering level