Lines Matching +full:no +full:- +full:hw +full:- +full:checksum
1 .. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
13 For details regarding the user-facing interface refer to the TLS
18 * Software crypto mode (``TLS_SW``) - CPU handles the cryptography.
24 * Packet-based NIC offload mode (``TLS_HW``) - the NIC handles crypto
28 (``ethtool`` flags ``tls-hw-tx-offload`` and ``tls-hw-rx-offload``).
29 * Full TCP NIC offload mode (``TLS_HW_RECORD``) - mode of operation where
33 abilities or QoS and packet scheduling (``ethtool`` flag ``tls-hw-record``).
36 offload opt-in or opt-out on per-connection basis is not currently supported.
39 --
52 --
63 .. kernel-figure:: tls-offload-layers.svg
82 network device is offload-capable and attempts the offload. In case offload
89 .. code-block:: c
98 to retrieve the connection 5-tuple and socket family (IPv4 vs IPv6).
108 --
121 --
138 There are no guarantees on record length or record segmentation. In particular
142 to be possible, the device has to keep a small amount of segment-to-segment
155 --
164 a connection identifier (note that a 5-tuple lookup is insufficient to identify
165 packets requiring HW offload, see the :ref:`5tuple_problems` section)
169 It replaces the authentication tag and TCP checksum with correct values.
172 --
176 checksum and performs a 5-tuple lookup to find any TLS connection the packet
177 may belong to (technically a 4-tuple
178 lookup is sufficient - IP addresses and TCP port numbers, as the protocol
184 per-packet context (descriptor) passed to the host.
189 and non-decrypted segments do not get coalesced (e.g. by GRO or socket layer)
206 --
209 in similar ways to the receive side-retransmissions - local drops
228 with the previous stream state - assuming that the out of order segment
245 .. code-block:: c
253 .. code-block:: c
263 --
269 .. kernel-figure:: tls-offload-reorder-good.svg
270 :alt: reorder of non-header segment
273 Reorder of non-header segment
294 .. kernel-figure:: tls-offload-reorder-bad.svg
323 and counting all records since the just-confirmed one, it adds the number
329 headers and never hear back from the kernel (there is no negative
331 restart scan. Given how unlikely falsely-matching stream is, however,
338 Stack-driven resynchronization
342 whenever it sees the records are no longer getting decrypted.
358 --
374 --
388 The Linux networking stack does not provide a way of reporting per-packet
409 --------------------
415 -------------------------------
420 significant performance impact on non-offloaded streams.
425 Following minimum set of TLS-related statistics should be reported
428 * ``rx_tls_decrypted_packets`` - number of successfully decrypted RX packets
430 * ``rx_tls_decrypted_bytes`` - number of TLS payload bytes in RX packets
432 * ``rx_tls_ctx`` - number of TLS RX HW offload contexts added to device for
434 * ``rx_tls_del`` - number of TLS RX HW offload contexts deleted from device
436 * ``rx_tls_resync_req_pkt`` - number of received TLS packets with a resync
438 * ``rx_tls_resync_req_start`` - number of times the TLS async resync request
440 * ``rx_tls_resync_req_end`` - number of times the TLS async resync request
441 properly ended with providing the HW tracked tcp-seq.
442 * ``rx_tls_resync_req_skip`` - number of times the TLS async resync request
444 * ``rx_tls_resync_res_ok`` - number of times the TLS resync response call to
446 * ``rx_tls_resync_res_skip`` - number of times the TLS resync response call to
448 * ``rx_tls_err`` - number of RX packets which were part of a TLS stream
450 * ``tx_tls_encrypted_packets`` - number of TX packets passed to the device
452 * ``tx_tls_encrypted_bytes`` - number of TLS payload bytes in TX packets
454 * ``tx_tls_ctx`` - number of TLS TX HW offload contexts added to device for
456 * ``tx_tls_ooo`` - number of TX packets which were part of a TLS stream
458 * ``tx_tls_skip_no_sync_data`` - number of TX packets which were part of
459 a TLS stream and arrived out-of-order, but skipped the HW offload routine
462 * ``tx_tls_drop_no_sync_data`` - number of TX packets which were part of
465 * ``tx_tls_drop_bypass_req`` - number of TX packets which were part of a TLS
474 5-tuple matching limitations
475 ----------------------------
477 The device can only recognize received packets based on the 5-tuple
482 any intermediate software device, therefore a 5-tuple match may
488 ------------
495 ---------------
502 -----------------------------------------------------
509 ----------------------------
518 -------------
526 -------------------
533 TLS encryption cannot be offloaded to devices without checksum calculation
535 Disabling the latter implies clearing the former. Disabling TX checksum offload
536 should not affect old connections, and drivers should make sure checksum
538 Similarly, device-offloaded TLS decryption implies doing RXCSUM. If the user