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: 46a3ea9807 ("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>
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 0608c69c9a ("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>
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: 32857cf57f ("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>
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Merge tag 'mlx5-fixes-2019-07-25' of 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>
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: 3c4d755915 ("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>
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>
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>
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>
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>
Tariq Toukan