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| author | Jakub Kicinski <kuba@kernel.org> | 2022-06-10 11:02:12 -0700 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2022-06-14 11:14:17 +0200 |
| commit | 7e5e8ec7dbd8504fdd04b5f6c9b6a207e54c4c6c (patch) | |
| tree | 44cc6507d41f1a774776e98ad65092a45ecb8d4c /Documentation | |
| parent | 19d62f5eeaa0fd912cc179530084403f90a5535a (diff) | |
docs: tls: document the TLS_TX_ZEROCOPY_RO
Add missing documentation for the TLS_TX_ZEROCOPY_RO opt-in.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Link: https://lore.kernel.org/r/20220610180212.110590-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/tls.rst | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/networking/tls.rst b/Documentation/networking/tls.rst index 8cb2cd4e2a80..be8e10c14b05 100644 --- a/Documentation/networking/tls.rst +++ b/Documentation/networking/tls.rst @@ -214,6 +214,31 @@ of calling send directly after a handshake using gnutls. Since it doesn't implement a full record layer, control messages are not supported. +Optional optimizations +---------------------- + +There are certain condition-specific optimizations the TLS ULP can make, +if requested. Those optimizations are either not universally beneficial +or may impact correctness, hence they require an opt-in. +All options are set per-socket using setsockopt(), and their +state can be checked using getsockopt() and via socket diag (``ss``). + +TLS_TX_ZEROCOPY_RO +~~~~~~~~~~~~~~~~~~ + +For device offload only. Allow sendfile() data to be transmitted directly +to the NIC without making an in-kernel copy. This allows true zero-copy +behavior when device offload is enabled. + +The application must make sure that the data is not modified between being +submitted and transmission completing. In other words this is mostly +applicable if the data sent on a socket via sendfile() is read-only. + +Modifying the data may result in different versions of the data being used +for the original TCP transmission and TCP retransmissions. To the receiver +this will look like TLS records had been tampered with and will result +in record authentication failures. + Statistics ========== |