Commit Graph

14 Commits

Author SHA1 Message Date
Vakul Garg
4504ab0e6e net/tls: Inform user space about send buffer availability
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: 7463d3a2db ("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>
2019-03-13 14:16:44 -07:00
Boris Pismenny
7463d3a2db tls: Fix write space handling
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: a42055e8d2 ("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>
2019-03-03 22:10:16 -08:00
Boris Pismenny
94850257cf tls: Fix tls_device handling of partial records
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: a42055e8d2 ("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>
2019-03-03 22:10:16 -08:00
Vakul Garg
4509de1468 net/tls: Move protocol constants from cipher context to tls context
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>
2019-02-19 10:40:36 -08:00
Dave Watson
130b392c6c net: tls: Add tls 1.3 support
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>
2019-02-01 15:00:55 -08:00
David Howells
aa563d7bca iov_iter: Separate type from direction and use accessor functions
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>
2018-10-24 00:41:07 +01:00
Daniel Borkmann
d829e9c411 tls: convert to generic sk_msg interface
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 80ece6a03a
("tls: Remove redundant vars from tls record structure") and
4e6d47206c ("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>
2018-10-15 12:23:19 -07:00
Sabrina Dubroca
86029d10af tls: zero the crypto information from tls_context before freeing
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: 3c4d755915 ("tls: kernel TLS support")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 12:03:47 -07:00
zhong jiang
969d509003 net/tls: Use kmemdup to simplify the code
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>
2018-08-01 09:47:47 -07:00
Gustavo A. R. Silva
eecd685770 tls: Fix copy-paste error in tls_device_reencrypt
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: 4799ac81e5 ("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>
2018-07-20 12:12:45 -07:00
Boris Pismenny
4799ac81e5 tls: Add rx inline crypto offload
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>
2018-07-16 00:13:11 -07:00
Boris Pismenny
d80a1b9d18 tls: Refactor tls_offload variable names
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>
2018-07-16 00:12:09 -07:00
Boris Pismenny
895262d857 tls: Fix tls_device initialization
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>
2018-05-10 17:54:20 -04:00
Ilya Lesokhin
e8f6979981 net/tls: Add generic NIC offload infrastructure
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>
2018-05-01 09:42:47 -04:00