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Commit 38030d7cb779 ("net/tls: avoid NULL-deref on resync during device removal")
tried to fix a potential NULL-dereference by taking the
context rwsem. Unfortunately the RX resync may get called
from soft IRQ, so we can't use the rwsem to protect from
the device disappearing. Because we are guaranteed there
can be only one resync at a time (it's called from strparser)
use a bit to indicate resync is busy and make device
removal wait for the bit to get cleared.
Note that there is a leftover "flags" field in struct
tls_context already.
Fixes: 4799ac81e52a ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This reverts commit 38030d7cb77963ba84cdbe034806e2b81245339f.
Unfortunately the RX resync may get called from soft IRQ,
so we can't take the rwsem to protect from the device
disappearing.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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On device surprise removal path (the notifier) we can't
bail just because the features are disabled. They may
have been enabled during the lifetime of the device.
This bug leads to leaking netdev references and
use-after-frees if there are active connections while
device features are cleared.
Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
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>
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TLS offload drivers shouldn't (and currently don't) block
the TLS offload feature changes based on whether there are
active offloaded connections or not.
This seems to be a good idea, because we want the admin to
be able to disable the TLS offload at any time, and there
is no clean way of disabling it for active connections
(TX side is quite problematic). So if features are cleared
existing connections will stay offloaded until they close,
and new connections will not attempt offload to a given
device.
However, the offload state removal handling is currently
broken if feature flags get cleared while there are
active TLS offloads.
RX side will completely bail from cleanup, even on normal
remove path, leaving device state dangling, potentially
causing issues when the 5-tuple is reused. It will also
fail to release the netdev reference.
Remove the RX-side warning message, in next release cycle
it should be printed when features are disabled, rather
than when connection dies, but for that we need a more
efficient method of finding connection of a given netdev
(a'la BPF offload code).
Fixes: 4799ac81e52a ("tls: Add rx inline crypto offload")
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>
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When netdev with active kTLS sockets in unregistered
notifier callback walks the offloaded sockets and
cleans up offload state. RX data may still be processed,
however, and if resync was requested prior to device
removal we would hit a NULL pointer dereference on
ctx->netdev use.
Make sure resync is under the device offload lock
and NULL-check the netdev pointer.
This should be safe, because the pointer is set to
NULL either in the netdev notifier (under said lock)
or when socket is completely dead and no resync can
happen.
The other access to ctx->netdev in tls_validate_xmit_skb()
does not dereference the pointer, it just checks it against
other device pointer, so it should be pretty safe (perhaps
we can add a READ_ONCE/WRITE_ONCE there, if paranoid).
Fixes: 4799ac81e52a ("tls: Add rx inline crypto offload")
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>
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Commit 4504ab0e6eb8 ("net/tls: Inform user space about send buffer availability")
made us report write_space regardless whether partial record
push was successful or not. Remove the now unused return value
to clean up the following W=1 warning:
net/tls/tls_device.c: In function ‘tls_device_write_space’:
net/tls/tls_device.c:546:6: warning: variable ‘rc’ set but not used [-Wunused-but-set-variable]
int rc = 0;
^~
CC: Vakul Garg <vakul.garg@nxp.com>
CC: Boris Pismenny <borisp@mellanox.com>
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>
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User space can flip the clean_acked_data_enabled static branch
on and off with TLS offload when CONFIG_TLS_DEVICE is enabled.
jump_label.h suggests we use the delayed version in this case.
Deferred branches now also don't take the branch mutex on
decrement, so we avoid potential locking issues.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Three trivial overlapping conflicts.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Fragments may contain data from other records so we have to account
for that when we calculate the destination and max length of copy we
can perform. Note that 'offset' is the offset within the message,
so it can't be passed as offset within the frag..
Here skb_store_bits() would have realised the call is wrong and
simply not copy data.
Fixes: 4799ac81e52a ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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There is no guarantee the record starts before the skb frags.
If we don't check for this condition copy amount will get
negative, leading to reads and writes to random memory locations.
Familiar hilarity ensues.
Fixes: 4799ac81e52a ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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To avoid a sparse warning byteswap the be32 sequence number
before it's stored in the atomic value. While at it drop
unnecessary brackets and use kernel's u64 type.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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tls_device_sk_destruct being set on a socket used to indicate
that socket is a kTLS device one. That is no longer true -
now we use sk_validate_xmit_skb pointer for that purpose.
Remove the export. tls_device_attach() needs to be moved.
While at it, remove the dead declaration of tls_sk_destruct().
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Currently when CONFIG_TLS_DEVICE is set each time kTLS
connection is opened and the offload is not successful
(either because the underlying device doesn't support
it or e.g. it's tables are full) a rate limited error
will be printed to the logs.
There is nothing wrong with failing TLS offload. SW
path will process the packets just fine, drop the
noisy messages.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When device refuses the offload in tls_set_device_offload_rx()
it calls tls_sw_free_resources_rx() to clean up software context
state.
Unfortunately, tls_sw_free_resources_rx() does not free all
the state tls_set_sw_offload() allocated - it leaks IV and
sequence number buffers. All other code paths which lead to
tls_sw_release_resources_rx() (which tls_sw_free_resources_rx()
calls) free those right before the call.
Avoid the leak by moving freeing of iv and rec_seq into
tls_sw_release_resources_rx().
Fixes: 4799ac81e52a ("tls: Add rx inline crypto offload")
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>
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If device supports offload, but offload fails tls_set_device_offload_rx()
will call tls_sw_free_resources_rx() which (unhelpfully) releases
and reacquires the socket lock.
For a small fix release and reacquire the device_offload_lock.
Fixes: 4799ac81e52a ("tls: Add rx inline crypto offload")
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>
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David reports that tls triggers warnings related to
sk->sk_forward_alloc not being zero at destruction time:
WARNING: CPU: 5 PID: 6831 at net/core/stream.c:206 sk_stream_kill_queues+0x103/0x110
WARNING: CPU: 5 PID: 6831 at net/ipv4/af_inet.c:160 inet_sock_destruct+0x15b/0x170
When sender fills up the write buffer and dies from
SIGPIPE. This is due to the device implementation
not cleaning up the partially_sent_record.
This is because commit a42055e8d2c3 ("net/tls: Add support for async encryption of records for performance")
moved the partial record cleanup to the SW-only path.
Fixes: a42055e8d2c3 ("net/tls: Add support for async encryption of records for performance")
Reported-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Commit f66de3ee2c16 ("net/tls: Split conf to rx + tx") made
freeing of IV and record sequence number conditional to SW
path only, but commit e8f69799810c ("net/tls: Add generic NIC
offload infrastructure") also allocates that state for the
device offload configuration. Remember to free it.
Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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A previous fix ("tls: Fix write space handling") assumed that
user space application gets informed about the socket send buffer
availability when tls_push_sg() gets called. Inside tls_push_sg(), in
case do_tcp_sendpages() returns 0, the function returns without calling
ctx->sk_write_space. Further, the new function tls_sw_write_space()
did not invoke ctx->sk_write_space. This leads to situation that user
space application encounters a lockup always waiting for socket send
buffer to become available.
Rather than call ctx->sk_write_space from tls_push_sg(), it should be
called from tls_write_space. So whenever tcp stack invokes
sk->sk_write_space after freeing socket send buffer, we always declare
the same to user space by the way of invoking ctx->sk_write_space.
Fixes: 7463d3a2db0ef ("tls: Fix write space handling")
Signed-off-by: Vakul Garg <vakul.garg@nxp.com>
Reviewed-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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TLS device cannot use the sw context. This patch returns the original
tls device write space handler and moves the sw/device specific portions
to the relevant files.
Also, we remove the write_space call for the tls_sw flow, because it
handles partial records in its delayed tx work handler.
Fixes: a42055e8d2c3 ("net/tls: Add support for async encryption of records for performance")
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Cleanup the handling of partial records while fixing a bug where the
tls_push_pending_closed_record function is using the software tls
context instead of the hardware context.
The bug resulted in the following crash:
[ 88.791229] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[ 88.793271] #PF error: [normal kernel read fault]
[ 88.794449] PGD 800000022a426067 P4D 800000022a426067 PUD 22a156067 PMD 0
[ 88.795958] Oops: 0000 [#1] SMP PTI
[ 88.796884] CPU: 2 PID: 4973 Comm: openssl Not tainted 5.0.0-rc4+ #3
[ 88.798314] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[ 88.800067] RIP: 0010:tls_tx_records+0xef/0x1d0 [tls]
[ 88.801256] Code: 00 02 48 89 43 08 e8 a0 0b 96 d9 48 89 df e8 48 dd
4d d9 4c 89 f8 4d 8b bf 98 00 00 00 48 05 98 00 00 00 48 89 04 24 49 39
c7 <49> 8b 1f 4d 89 fd 0f 84 af 00 00 00 41 8b 47 10 85 c0 0f 85 8d 00
[ 88.805179] RSP: 0018:ffffbd888186fca8 EFLAGS: 00010213
[ 88.806458] RAX: ffff9af1ed657c98 RBX: ffff9af1e88a1980 RCX: 0000000000000000
[ 88.808050] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9af1e88a1980
[ 88.809724] RBP: ffff9af1e88a1980 R08: 0000000000000017 R09: ffff9af1ebeeb700
[ 88.811294] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[ 88.812917] R13: ffff9af1e88a1980 R14: ffff9af1ec13f800 R15: 0000000000000000
[ 88.814506] FS: 00007fcad2240740(0000) GS:ffff9af1f7880000(0000) knlGS:0000000000000000
[ 88.816337] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 88.817717] CR2: 0000000000000000 CR3: 0000000228b3e000 CR4: 00000000001406e0
[ 88.819328] Call Trace:
[ 88.820123] tls_push_data+0x628/0x6a0 [tls]
[ 88.821283] ? remove_wait_queue+0x20/0x60
[ 88.822383] ? n_tty_read+0x683/0x910
[ 88.823363] tls_device_sendmsg+0x53/0xa0 [tls]
[ 88.824505] sock_sendmsg+0x36/0x50
[ 88.825492] sock_write_iter+0x87/0x100
[ 88.826521] __vfs_write+0x127/0x1b0
[ 88.827499] vfs_write+0xad/0x1b0
[ 88.828454] ksys_write+0x52/0xc0
[ 88.829378] do_syscall_64+0x5b/0x180
[ 88.830369] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 88.831603] RIP: 0033:0x7fcad1451680
[ 1248.470626] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[ 1248.472564] #PF error: [normal kernel read fault]
[ 1248.473790] PGD 0 P4D 0
[ 1248.474642] Oops: 0000 [#1] SMP PTI
[ 1248.475651] CPU: 3 PID: 7197 Comm: openssl Tainted: G OE 5.0.0-rc4+ #3
[ 1248.477426] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[ 1248.479310] RIP: 0010:tls_tx_records+0x110/0x1f0 [tls]
[ 1248.480644] Code: 00 02 48 89 43 08 e8 4f cb 63 d7 48 89 df e8 f7 9c
1b d7 4c 89 f8 4d 8b bf 98 00 00 00 48 05 98 00 00 00 48 89 04 24 49 39
c7 <49> 8b 1f 4d 89 fd 0f 84 af 00 00 00 41 8b 47 10 85 c0 0f 85 8d 00
[ 1248.484825] RSP: 0018:ffffaa0a41543c08 EFLAGS: 00010213
[ 1248.486154] RAX: ffff955a2755dc98 RBX: ffff955a36031980 RCX: 0000000000000006
[ 1248.487855] RDX: 0000000000000000 RSI: 000000000000002b RDI: 0000000000000286
[ 1248.489524] RBP: ffff955a36031980 R08: 0000000000000000 R09: 00000000000002b1
[ 1248.491394] R10: 0000000000000003 R11: 00000000ad55ad55 R12: 0000000000000000
[ 1248.493162] R13: 0000000000000000 R14: ffff955a2abe6c00 R15: 0000000000000000
[ 1248.494923] FS: 0000000000000000(0000) GS:ffff955a378c0000(0000) knlGS:0000000000000000
[ 1248.496847] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1248.498357] CR2: 0000000000000000 CR3: 000000020c40e000 CR4: 00000000001406e0
[ 1248.500136] Call Trace:
[ 1248.500998] ? tcp_check_oom+0xd0/0xd0
[ 1248.502106] tls_sk_proto_close+0x127/0x1e0 [tls]
[ 1248.503411] inet_release+0x3c/0x60
[ 1248.504530] __sock_release+0x3d/0xb0
[ 1248.505611] sock_close+0x11/0x20
[ 1248.506612] __fput+0xb4/0x220
[ 1248.507559] task_work_run+0x88/0xa0
[ 1248.508617] do_exit+0x2cb/0xbc0
[ 1248.509597] ? core_sys_select+0x17a/0x280
[ 1248.510740] do_group_exit+0x39/0xb0
[ 1248.511789] get_signal+0x1d0/0x630
[ 1248.512823] do_signal+0x36/0x620
[ 1248.513822] exit_to_usermode_loop+0x5c/0xc6
[ 1248.515003] do_syscall_64+0x157/0x180
[ 1248.516094] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1248.517456] RIP: 0033:0x7fb398bd3f53
[ 1248.518537] Code: Bad RIP value.
Fixes: a42055e8d2c3 ("net/tls: Add support for async encryption of records for performance")
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Each tls context maintains two cipher contexts (one each for tx and rx
directions). For each tls session, the constants such as protocol
version, ciphersuite, iv size, associated data size etc are same for
both the directions and need to be stored only once per tls context.
Hence these are moved from 'struct cipher_context' to 'struct
tls_prot_info' and stored only once in 'struct tls_context'.
Signed-off-by: Vakul Garg <vakul.garg@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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TLS 1.3 has minor changes from TLS 1.2 at the record layer.
* Header now hardcodes the same version and application content type in
the header.
* The real content type is appended after the data, before encryption (or
after decryption).
* The IV is xored with the sequence number, instead of concatinating four
bytes of IV with the explicit IV.
* Zero-padding: No exlicit length is given, we search backwards from the
end of the decrypted data for the first non-zero byte, which is the
content type. Currently recv supports reading zero-padding, but there
is no way for send to add zero padding.
Signed-off-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.
Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements. This makes it easier to add further
iterator types. Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.
Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself. Only the direction is required.
Signed-off-by: David Howells <dhowells@redhat.com>
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Convert kTLS over to make use of sk_msg interface for plaintext and
encrypted scattergather data, so it reuses all the sk_msg helpers
and data structure which later on in a second step enables to glue
this to BPF.
This also allows to remove quite a bit of open coded helpers which
are covered by the sk_msg API. Recent changes in kTLs 80ece6a03aaf
("tls: Remove redundant vars from tls record structure") and
4e6d47206c32 ("tls: Add support for inplace records encryption")
changed the data path handling a bit; while we've kept the latter
optimization intact, we had to undo the former change to better
fit the sk_msg model, hence the sg_aead_in and sg_aead_out have
been brought back and are linked into the sk_msg sgs. Now the kTLS
record contains a msg_plaintext and msg_encrypted sk_msg each.
In the original code, the zerocopy_from_iter() has been used out
of TX but also RX path. For the strparser skb-based RX path,
we've left the zerocopy_from_iter() in decrypt_internal() mostly
untouched, meaning it has been moved into tls_setup_from_iter()
with charging logic removed (as not used from RX). Given RX path
is not based on sk_msg objects, we haven't pursued setting up a
dummy sk_msg to call into sk_msg_zerocopy_from_iter(), but it
could be an option to prusue in a later step.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This contains key material in crypto_send_aes_gcm_128 and
crypto_recv_aes_gcm_128.
Introduce union tls_crypto_context, and replace the two identical
unions directly embedded in struct tls_context with it. We can then
use this union to clean up the memory in the new tls_ctx_free()
function.
Fixes: 3c4d7559159b ("tls: kernel TLS support")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Kmemdup is better than kmalloc+memcpy. So replace them.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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It seems that the proper structure to use in this particular
case is *skb_iter* instead of skb.
Addresses-Coverity-ID: 1471906 ("Copy-paste error")
Fixes: 4799ac81e52a ("tls: Add rx inline crypto offload")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch completes the generic infrastructure to offload TLS crypto to a
network device. It enables the kernel to skip decryption and
authentication of some skbs marked as decrypted by the NIC. In the fast
path, all packets received are decrypted by the NIC and the performance
is comparable to plain TCP.
This infrastructure doesn't require a TCP offload engine. Instead, the
NIC only decrypts packets that contain the expected TCP sequence number.
Out-Of-Order TCP packets are provided unmodified. As a result, at the
worst case a received TLS record consists of both plaintext and ciphertext
packets. These partially decrypted records must be reencrypted,
only to be decrypted.
The notable differences between SW KTLS Rx and this offload are as
follows:
1. Partial decryption - Software must handle the case of a TLS record
that was only partially decrypted by HW. This can happen due to packet
reordering.
2. Resynchronization - tls_read_size calls the device driver to
resynchronize HW after HW lost track of TLS record framing in
the TCP stream.
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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For symmetry, we rename tls_offload_context to
tls_offload_context_tx before we add tls_offload_context_rx.
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add sg table initialization to fix a BUG_ON encountered when enabling
CONFIG_DEBUG_SG.
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch adds a generic infrastructure to offload TLS crypto to a
network device. It enables the kernel TLS socket to skip encryption
and authentication operations on the transmit side of the data path.
Leaving those computationally expensive operations to the NIC.
The NIC offload infrastructure builds TLS records and pushes them to
the TCP layer just like the SW KTLS implementation and using the same
API.
TCP segmentation is mostly unaffected. Currently the only exception is
that we prevent mixed SKBs where only part of the payload requires
offload. In the future we are likely to add a similar restriction
following a change cipher spec record.
The notable differences between SW KTLS and NIC offloaded TLS
implementations are as follows:
1. The offloaded implementation builds "plaintext TLS record", those
records contain plaintext instead of ciphertext and place holder bytes
instead of authentication tags.
2. The offloaded implementation maintains a mapping from TCP sequence
number to TLS records. Thus given a TCP SKB sent from a NIC offloaded
TLS socket, we can use the tls NIC offload infrastructure to obtain
enough context to encrypt the payload of the SKB.
A TLS record is released when the last byte of the record is ack'ed,
this is done through the new icsk_clean_acked callback.
The infrastructure should be extendable to support various NIC offload
implementations. However it is currently written with the
implementation below in mind:
The NIC assumes that packets from each offloaded stream are sent as
plaintext and in-order. It keeps track of the TLS records in the TCP
stream. When a packet marked for offload is transmitted, the NIC
encrypts the payload in-place and puts authentication tags in the
relevant place holders.
The responsibility for handling out-of-order packets (i.e. TCP
retransmission, qdisc drops) falls on the netdev driver.
The netdev driver keeps track of the expected TCP SN from the NIC's
perspective. If the next packet to transmit matches the expected TCP
SN, the driver advances the expected TCP SN, and transmits the packet
with TLS offload indication.
If the next packet to transmit does not match the expected TCP SN. The
driver calls the TLS layer to obtain the TLS record that includes the
TCP of the packet for transmission. Using this TLS record, the driver
posts a work entry on the transmit queue to reconstruct the NIC TLS
state required for the offload of the out-of-order packet. It updates
the expected TCP SN accordingly and transmits the now in-order packet.
The same queue is used for packet transmission and TLS context
reconstruction to avoid the need for flushing the transmit queue before
issuing the context reconstruction request.
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Aviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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