The .rst documentation contains a brief description of the user interface and includes kernel-doc generated from uapi header.
Signed-off-by: Leonard Crestez cdleonard@gmail.com --- Documentation/networking/index.rst | 1 + Documentation/networking/tcp_authopt.rst | 44 ++++++++++++++++++++++++ 2 files changed, 45 insertions(+) create mode 100644 Documentation/networking/tcp_authopt.rst
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst index 58bc8cd367c6..f5c324a060d8 100644 --- a/Documentation/networking/index.rst +++ b/Documentation/networking/index.rst @@ -100,10 +100,11 @@ Contents: strparser switchdev sysfs-tagging tc-actions-env-rules tcp-thin + tcp_authopt team timestamping tipc tproxy tuntap diff --git a/Documentation/networking/tcp_authopt.rst b/Documentation/networking/tcp_authopt.rst new file mode 100644 index 000000000000..484f66f41ad5 --- /dev/null +++ b/Documentation/networking/tcp_authopt.rst @@ -0,0 +1,44 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========================= +TCP Authentication Option +========================= + +The TCP Authentication option specified by RFC5925 replaces the TCP MD5 +Signature option. It similar in goals but not compatible in either wire formats +or ABI. + +Interface +========= + +Individual keys can be added to or removed from a TCP socket by using +TCP_AUTHOPT_KEY setsockopt and a ``struct tcp_authopt_key``. There is no +support for reading back keys and updates always replace the old key. These +structures represent "Master Key Tuples (MKTs)" as described by the RFC. + +Per-socket options can set or read using the TCP_AUTHOPT sockopt and a ``struct +tcp_authopt``. This is optional: doing setsockopt TCP_AUTHOPT_KEY is +sufficient to enable the feature. + +Configuration associated with TCP Authentication is indepedently attached to +each TCP socket. After listen and accept the newly returned socket gets an +independent copy of relevant settings from the listen socket. + +Key binding +----------- + +Keys can be bound to remote addresses in a way that is similar to TCP_MD5. + + * The full address must match (/32 or /128) + * Ports are ignored + * Address binding is optional, by default keys match all addresses + +RFC5925 requires that key ids do not overlap when tcp identifiers (addr/port) +overlap. This is not enforced by linux, configuring ambiguous keys will result +in packet drops and lost connections. + +ABI Reference +============= + +.. kernel-doc:: include/uapi/linux/tcp.h + :identifiers: tcp_authopt tcp_authopt_flag tcp_authopt_key tcp_authopt_key_flag tcp_authopt_alg