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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/net | |
| 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/net')
| -rw-r--r-- | include/net/tls.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/net/tls.h b/include/net/tls.h index 857340338b69..f2af113728aa 100644 --- a/include/net/tls.h +++ b/include/net/tls.h @@ -53,6 +53,8 @@ struct tls_rec; /* Maximum data size carried in a TLS record */ #define TLS_MAX_PAYLOAD_SIZE ((size_t)1 << 14) +/* Minimum record size limit as per RFC8449 */ +#define TLS_MIN_RECORD_SIZE_LIM ((size_t)1 << 6) #define TLS_HEADER_SIZE 5 #define TLS_NONCE_OFFSET TLS_HEADER_SIZE @@ -226,6 +228,7 @@ struct tls_context { u8 rx_conf:3; u8 zerocopy_sendfile:1; u8 rx_no_pad:1; + u16 tx_max_payload_len; int (*push_pending_record)(struct sock *sk, int flags); void (*sk_write_space)(struct sock *sk); |