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| author | Jason Baron <jbaron@akamai.com> | 2019-05-29 18:34:00 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-05-30 22:41:26 +0200 |
| commit | 2dc7e48dee68219dd8921824473306036ea45152 (patch) | |
| tree | 34caa508f761a70985830a0a8b3716346d0905c4 /Documentation/networking | |
| parent | tcp: add support for optional TFO backup key to net.ipv4.tcp_fastopen_key (diff) | |
| download | linux-2dc7e48dee68219dd8921824473306036ea45152.tar.xz linux-2dc7e48dee68219dd8921824473306036ea45152.zip | |
Documentation: ip-sysctl.txt: Document tcp_fastopen_key
Add docs for /proc/sys/net/ipv4/tcp_fastopen_key
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Cc: Jeremy Sowden <jeremy@azazel.net>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 14fe93049d28..a73b3a02e49a 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -648,6 +648,26 @@ tcp_fastopen_blackhole_timeout_sec - INTEGER 0 to disable the blackhole detection. By default, it is set to 1hr. +tcp_fastopen_key - list of comma separated 32-digit hexadecimal INTEGERs + The list consists of a primary key and an optional backup key. The + primary key is used for both creating and validating cookies, while the + optional backup key is only used for validating cookies. The purpose of + the backup key is to maximize TFO validation when keys are rotated. + + A randomly chosen primary key may be configured by the kernel if + the tcp_fastopen sysctl is set to 0x400 (see above), or if the + TCP_FASTOPEN setsockopt() optname is set and a key has not been + previously configured via sysctl. If keys are configured via + setsockopt() by using the TCP_FASTOPEN_KEY optname, then those + per-socket keys will be used instead of any keys that are specified via + sysctl. + + A key is specified as 4 8-digit hexadecimal integers which are separated + by a '-' as: xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxxxx. Leading zeros may be + omitted. A primary and a backup key may be specified by separating them + by a comma. If only one key is specified, it becomes the primary key and + any previously configured backup keys are removed. + 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 |