A duplicated null check on sgout is redundant as it is known to be
already true because of the identical earlier check. Remove it.
Detected by cppcheck:

net/tls/tls_sw.c:696: (warning) Identical inner 'if' condition is always
true.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the quest to remove VLAs from the kernel[1], this replaces the VLA
size with the only possible size used in the code, and adds a mechanism
to double-check future IV sizes.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.comSigned-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NDave Watson <davejwatson@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add rx path for tls software implementation.

recvmsg, splice_read, and poll implemented.

An additional sockopt TLS_RX is added, with the same interface as
TLS_TX.  Either TLX_RX or TLX_TX may be provided separately, or
together (with two different setsockopt calls with appropriate keys).

Control messages are passed via CMSG in a similar way to transmit.
If no cmsg buffer is passed, then only application data records
will be passed to userspace, and EIO is returned for other types of
alerts.

EBADMSG is passed for decryption errors, and EMSGSIZE is passed for
framing too big, and EBADMSG for framing too small (matching openssl
semantics). EINVAL is returned for TLS versions that do not match the
original setsockopt call.  All are unrecoverable.

strparser is used to parse TLS framing.   Decryption is done directly
in to userspace buffers if they are large enough to support it, otherwise
sk_cow_data is called (similar to ipsec), and buffers are decrypted in
place and copied.  splice_read always decrypts in place, since no
buffers are provided to decrypt in to.

sk_poll is overridden, and only returns POLLIN if a full TLS message is
received.  Otherwise we wait for strparser to finish reading a full frame.
Actual decryption is only done during recvmsg or splice_read calls.
Signed-off-by: NDave Watson <davejwatson@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass EBADMSG explicitly to tls_err_abort.  Receive path will
pass additional codes - EMSGSIZE if framing is larger than max
TLS record size, EINVAL if TLS version mismatch.
Signed-off-by: NDave Watson <davejwatson@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Separate tx crypto parameters to a separate cipher_context struct.
The same parameters will be used for rx using the same struct.

tls_advance_record_sn is modified to only take the cipher info.
Signed-off-by: NDave Watson <davejwatson@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Refactor zerocopy_from_iter to take arguments for pages and size,
such that it can be used for both tx and rx. RX will also support
zerocopy direct to output iter, as long as the full message can
be copied at once (a large enough userspace buffer was provided).
Signed-off-by: NDave Watson <davejwatson@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current implementation of sk_alloc_sg expects scatterlist to always
start at entry 0 and complete at entry MAX_SKB_FRAGS.

Future patches will want to support starting at arbitrary offset into
scatterlist so add an additional sg_start parameters and then default
to the current values in TLS code paths.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The TLS ULP module builds scatterlists from a sock using
page_frag_refill(). This is going to be useful for other ULPs
so move it into sock file for more general use.

In the process remove useless goto at end of while loop.
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Async crypto accelerators (e.g. drivers/crypto/caam) support offloading
GCM operation. If they are enabled, crypto_aead_encrypt() return error
code -EINPROGRESS. In this case tls_do_encryption() needs to wait on a
completion till the time the response for crypto offload request is
received.
Signed-off-by: NVakul Garg <vakul.garg@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The scatterlist is reused by both sendmsg and sendfile.
If a sendmsg of smaller number of pages is followed by a sendfile
of larger number of pages, the scatterlist may be too short, resulting
in a crash in gcm_encrypt.

Add sg_unmark_end to make the list the correct length.

tls_sw_sendmsg already calls sg_unmark_end correctly when it allocates
memory in alloc_sg, or in zerocopy_from_iter.
Signed-off-by: NDave Watson <davejwatson@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During setsockopt(SOL_TCP, TLS_TX), if initialization of the software
context fails in tls_set_sw_offload(), we leak sw_ctx. We also don't
reassign ctx->priv_ctx to NULL, so we can't even do another attempt to
set it up on the same socket, as it will fail with -EEXIST.

Fixes: 3c4d7559 ('tls: kernel TLS support')
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sendfile() calls can hang endless with using Kernel TLS if a socket error occurs.
Socket error codes must be inverted by Kernel TLS before returning because
they are stored with positive sign. If returned non-inverted they are
interpreted as number of bytes sent, causing endless looping of the
splice mechanic behind sendfile().
Signed-off-by: NRobert Hering <r.hering@avm.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

move tls_make_aad as it is going to be reused
by the device offload code and rx path.
Remove unused recv parameter.
Signed-off-by: NIlya Lesokhin <ilyal@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously the TLS ulp context would leak if we attached a TLS ulp
to a socket but did not use the TLS_TX setsockopt,
or did use it but it failed.
This patch solves the issue by overriding prot[TLS_BASE_TX].close
and fixing tls_sk_proto_close to work properly
when its called with ctx->tx_conf == TLS_BASE_TX.
This patch also removes ctx->free_resources as we can use ctx->tx_conf
to obtain the relevant information.

Fixes: 3c4d7559 ('tls: kernel TLS support')
Signed-off-by: NIlya Lesokhin <ilyal@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use kzalloc for aead_request allocation as
we don't set all the bits in the request.

Fixes: 3c4d7559 ('tls: kernel TLS support')
Signed-off-by: NIlya Lesokhin <ilyal@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make the needlessly global function tls_sw_free_resources static to fix
a gcc/sparse warning.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Software implementation of transport layer security, implemented using ULP
infrastructure.  tcp proto_ops are replaced with tls equivalents of sendmsg and
sendpage.

Only symmetric crypto is done in the kernel, keys are passed by setsockopt
after the handshake is complete.  All control messages are supported via CMSG
data - the actual symmetric encryption is the same, just the message type needs
to be passed separately.

For user API, please see Documentation patch.

Pieces that can be shared between hw and sw implementation
are in tls_main.c
Signed-off-by: NBoris Pismenny <borisp@mellanox.com>
Signed-off-by: NIlya Lesokhin <ilyal@mellanox.com>
Signed-off-by: NAviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: NDave Watson <davejwatson@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>