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2021-01-19net: Disable NETIF_F_HW_TLS_RX when RXCSUM is disabledTariq Toukan
With NETIF_F_HW_TLS_RX packets are decrypted in HW. This cannot be logically done when RXCSUM offload is off. Fixes: 14136564c8ee ("net: Add TLS RX offload feature") Signed-off-by: Tariq Toukan <tariqt@nvidia.com> Reviewed-by: Boris Pismenny <borisp@nvidia.com> Link: https://lore.kernel.org/r/20210117151538.9411-1-tariqt@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-14net: Allow NETIF_F_HW_TLS_TX if IP_CSUM && IPV6_CSUMTariq Toukan
Cited patch below blocked the TLS TX device offload unless HW_CSUM is set. This broke devices that use IP_CSUM && IP6_CSUM. Here we fix it. Note that the single HW_TLS_TX feature flag indicates support for both IPv4/6, hence it should still be disabled in case only one of (IP_CSUM | IPV6_CSUM) is set. Fixes: ae0b04b238e2 ("net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled") Signed-off-by: Tariq Toukan <tariqt@nvidia.com> Reported-by: Rohit Maheshwari <rohitm@chelsio.com> Reviewed-by: Maxim Mikityanskiy <maximmi@mellanox.com> Link: https://lore.kernel.org/r/20210114151215.7061-1-tariqt@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-14net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabledTariq Toukan
With NETIF_F_HW_TLS_TX packets are encrypted in HW. This cannot be logically done when HW_CSUM offload is off. Fixes: 2342a8512a1e ("net: Add TLS TX offload features") Signed-off-by: Tariq Toukan <tariqt@nvidia.com> Reviewed-by: Boris Pismenny <borisp@nvidia.com> Link: https://lore.kernel.org/r/20201213143929.26253-1-tariqt@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-06-27net/mlx5e: kTLS, Add kTLS RX statsTariq Toukan
Add global and per-channel ethtool SW stats for the device offload. Document the new counters in tls-offload.rst. Signed-off-by: Tariq Toukan <tariqt@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-11-05Documentation: TLS: Add missing counter descriptionTariq Toukan
Add TLS TX counter description for the handshake retransmitted packets that triggers the resync procedure then skip it, going into the regular transmit flow. Fixes: 46a3ea98074e ("net/mlx5e: kTLS, Enhance TX resync flow") Signed-off-by: Tariq Toukan <tariqt@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-08net/tls: prevent skb_orphan() from leaking TLS plain text with offloadJakub Kicinski
sk_validate_xmit_skb() and drivers depend on the sk member of struct sk_buff to identify segments requiring encryption. Any operation which removes or does not preserve the original TLS socket such as skb_orphan() or skb_clone() will cause clear text leaks. Make the TCP socket underlying an offloaded TLS connection mark all skbs as decrypted, if TLS TX is in offload mode. Then in sk_validate_xmit_skb() catch skbs which have no socket (or a socket with no validation) and decrypted flag set. Note that CONFIG_SOCK_VALIDATE_XMIT, CONFIG_TLS_DEVICE and sk->sk_validate_xmit_skb are slightly interchangeable right now, they all imply TLS offload. The new checks are guarded by CONFIG_TLS_DEVICE because that's the option guarding the sk_buff->decrypted member. Second, smaller issue with orphaning is that it breaks the guarantee that packets will be delivered to device queues in-order. All TLS offload drivers depend on that scheduling property. This means skb_orphan_partial()'s trick of preserving partial socket references will cause issues in the drivers. We need a full orphan, and as a result netem delay/throttling will cause all TLS offload skbs to be dropped. Reusing the sk_buff->decrypted flag also protects from leaking clear text when incoming, decrypted skb is redirected (e.g. by TC). See commit 0608c69c9a80 ("bpf: sk_msg, sock{map|hash} redirect through ULP") for justification why the internal flag is safe. The only location which could leak the flag in is tcp_bpf_sendmsg(), which is taken care of by clearing the previously unused bit. v2: - remove superfluous decrypted mark copy (Willem); - remove the stale doc entry (Boris); - rely entirely on EOR marking to prevent coalescing (Boris); - use an internal sendpages flag instead of marking the socket (Boris). v3 (Willem): - reorganize the can_skb_orphan_partial() condition; - fix the flag leak-in through tcp_bpf_sendmsg. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-05net/tls: partially revert fix transition through disconnect with closeJakub Kicinski
Looks like we were slightly overzealous with the shutdown() cleanup. Even though the sock->sk_state can reach CLOSED again, socket->state will not got back to SS_UNCONNECTED once connections is ESTABLISHED. Meaning we will see EISCONN if we try to reconnect, and EINVAL if we try to listen. Only listen sockets can be shutdown() and reused, but since ESTABLISHED sockets can never be re-connected() or used for listen() we don't need to try to clean up the ULP state early. Fixes: 32857cf57f92 ("net/tls: fix transition through disconnect with close") Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-26Merge tag 'mlx5-fixes-2019-07-25' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux Saeed Mahameed says: ==================== Mellanox, mlx5 fixes 2019-07-25 This series introduces some fixes to mlx5 driver. 1) Ariel is addressing an issue with enacp flow counter race condition 2) Aya fixes ethtool speed handling 3) Edward fixes modify_cq hw bits alignment 4) Maor fixes RDMA_RX capabilities handling 5) Mark reverses unregister devices order to address an issue with LAG 6) From Tariq, - wrong max num channels indication regression - TLS counters naming and documentation as suggested by Jakub - kTLS, Call WARN_ONCE on netdev mismatch There is one patch in this series that touches nfp driver to align TLS statistics names with latest documentation, Jakub is CC'ed. Please pull and let me know if there is any problem. For -stable v4.9: ('net/mlx5: Use reversed order when unregister devices') For -stable v4.20 ('net/mlx5e: Prevent encap flow counter update async to user query') ('net/mlx5: Fix modify_cq_in alignment') For -stable v5.1 ('net/mlx5e: Fix matching of speed to PRM link modes') For -stable v5.2 ('net/mlx5: Add missing RDMA_RX capabilities') ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-25Documentation: TLS: fix stat counters descriptionTariq Toukan
Add missing description of counters. Split tx_tls_encrypted counter into two, to give packets and bytes indications. Fixes: f42c104f2ec9 ("Documentation: add TLS offload documentation") Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Tariq Toukan <tariqt@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-07-22net/tls: fix transition through disconnect with closeJohn Fastabend
It is possible (via shutdown()) for TCP socks to go through TCP_CLOSE state via tcp_disconnect() without actually calling tcp_close which would then call the tls close callback. Because of this a user could disconnect a socket then put it in a LISTEN state which would break our assumptions about sockets always being ESTABLISHED state. More directly because close() can call unhash() and unhash is implemented by sockmap if a sockmap socket has TLS enabled we can incorrectly destroy the psock from unhash() and then call its close handler again. But because the psock (sockmap socket representation) is already destroyed we call close handler in sk->prot. However, in some cases (TLS BASE/BASE case) this will still point at the sockmap close handler resulting in a circular call and crash reported by syzbot. To fix both above issues implement the unhash() routine for TLS. v4: - add note about tls offload still needing the fix; - move sk_proto to the cold cache line; - split TX context free into "release" and "free", otherwise the GC work itself is in already freed memory; - more TX before RX for consistency; - reuse tls_ctx_free(); - schedule the GC work after we're done with context to avoid UAF; - don't set the unhash in all modes, all modes "inherit" TLS_BASE's callbacks anyway; - disable the unhash hook for TLS_HW. Fixes: 3c4d7559159bf ("tls: kernel TLS support") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-11net/tls: add kernel-driven resync mechanism for TXJakub Kicinski
TLS offload drivers keep track of TCP seq numbers to make sure the packets are fed into the HW in order. When packets get dropped on the way through the stack, the driver will get out of sync and have to use fallback encryption, but unless TCP seq number is resynced it will never match the packets correctly (or even worse - use incorrect record sequence number after TCP seq wraps). Existing drivers (mlx5) feed the entire record on every out-of-order event, allowing FW/HW to always be in sync. This patch adds an alternative, more akin to the RX resync. When driver sees a frame which is past its expected sequence number the stream must have gotten out of order (if the sequence number is smaller than expected its likely a retransmission which doesn't require resync). Driver will ask the stack to perform TX sync before it submits the next full record, and fall back to software crypto until stack has performed the sync. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-11net/tls: add kernel-driven TLS RX resyncJakub Kicinski
TLS offload device may lose sync with the TCP stream if packets arrive out of order. Drivers can currently request a resync at a specific TCP sequence number. When a record is found starting at that sequence number kernel will inform the device of the corresponding record number. This requires the device to constantly scan the stream for a known pattern (constant bytes of the header) after sync is lost. This patch adds an alternative approach which is entirely under the control of the kernel. Kernel tracks records it had to fully decrypt, even though TLS socket is in TLS_HW mode. If multiple records did not have any decrypted parts - it's a pretty strong indication that the device is out of sync. We choose the min number of fully encrypted records to be 2, which should hopefully be more than will get retransmitted at a time. After kernel decides the device is out of sync it schedules a resync request. If the TCP socket is empty the resync gets performed immediately. If socket is not empty we leave the record parser to resync when next record comes. Before resync in message parser we peek at the TCP socket and don't attempt the sync if the socket already has some of the next record queued. On resync failure (encrypted data continues to flow in) we retry with exponential backoff, up to once every 128 records (with a 16k record thats at most once every 2M of data). Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-04net/tls: remove false positive warningJakub Kicinski
It's possible that TCP stack will decide to retransmit a packet right when that packet's data gets acked, especially in presence of packet reordering. This means that packets may be in flight, even though tls_device code has already freed their record state. Make fill_sg_in() and in turn tls_sw_fallback() not generate a warning in that case, and quietly proceed to drop such frames. Make the exit path from tls_sw_fallback() drop monitor friendly, for users to be able to troubleshoot dropped retransmissions. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-22Documentation: add TLS offload documentationJakub Kicinski
Describe existing kernel TLS offload (added back in Linux 4.19) - the mechanism, the expected behavior and the notable corner cases. This documentation is mostly targeting hardware vendors who want to implement offload, to ensure consistency between implementations. v2: - add emphasis around TLS_SW/TLS_HW/TLS_HW_RECORD; - remove mentions of ongoing work (Boris); - split the flow of data in SW vs. HW cases in TX overview (Boris); - call out which fields are updated by the device and which are filled by the stack (Boris); - move error handling into it's own section (Boris); - add more words about fallback (Boris); - note that checksum validation is required (Alexei); - note that drivers shouldn't pay attention to the TLS device features. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Dave Watson <davejwatson@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>