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| author | Wilfred Mallawa <wilfred.mallawa@wdc.com> | 2025-10-22 03:19:36 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-10-28 02:13:42 +0300 |
| commit | 82cb5be6ad64198a3a028aeb49dcc7f6224d558a (patch) | |
| tree | a20a77d0eac5efa1b2c797b5d87b4e65b8e5b18e /include/uapi/linux | |
| parent | bfe62db5422b1a5f25752bd0877a097d436d876d (diff) | |
| download | linux-82cb5be6ad64198a3a028aeb49dcc7f6224d558a.tar.xz | |
net/tls: support setting the maximum payload size
During a handshake, an endpoint may specify a maximum record size limit.
Currently, the kernel defaults to TLS_MAX_PAYLOAD_SIZE (16KB) for the
maximum record size. Meaning that, the outgoing records from the kernel
can exceed a lower size negotiated during the handshake. In such a case,
the TLS endpoint must send a fatal "record_overflow" alert [1], and
thus the record is discarded.
Upcoming Western Digital NVMe-TCP hardware controllers implement TLS
support. For these devices, supporting TLS record size negotiation is
necessary because the maximum TLS record size supported by the controller
is less than the default 16KB currently used by the kernel.
Currently, there is no way to inform the kernel of such a limit. This patch
adds support to a new setsockopt() option `TLS_TX_MAX_PAYLOAD_LEN` that
allows for setting the maximum plaintext fragment size. Once set, outgoing
records are no larger than the size specified. This option can be used to
specify the record size limit.
[1] https://www.rfc-editor.org/rfc/rfc8449
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20251022001937.20155-1-wilfred.opensource@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/uapi/linux')
| -rw-r--r-- | include/uapi/linux/tls.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/uapi/linux/tls.h b/include/uapi/linux/tls.h index b66a800389cc..b8b9c42f848c 100644 --- a/include/uapi/linux/tls.h +++ b/include/uapi/linux/tls.h @@ -41,6 +41,7 @@ #define TLS_RX 2 /* Set receive parameters */ #define TLS_TX_ZEROCOPY_RO 3 /* TX zerocopy (only sendfile now) */ #define TLS_RX_EXPECT_NO_PAD 4 /* Attempt opportunistic zero-copy */ +#define TLS_TX_MAX_PAYLOAD_LEN 5 /* Maximum plaintext size */ /* Supported versions */ #define TLS_VERSION_MINOR(ver) ((ver) & 0xFF) @@ -194,6 +195,7 @@ enum { TLS_INFO_RXCONF, TLS_INFO_ZC_RO_TX, TLS_INFO_RX_NO_PAD, + TLS_INFO_TX_MAX_PAYLOAD_LEN, __TLS_INFO_MAX, }; #define TLS_INFO_MAX (__TLS_INFO_MAX - 1) |