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path: root/net/tls/Kconfig
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2018-05-01net/tls: Add generic NIC offload infrastructureIlya Lesokhin
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>
2018-03-23tls: RX path for ktlsDave Watson
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: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17tls: update KconfigDave Watson
Missing crypto deps for some platforms. Default to n for new module. config: m68k-amcore_defconfig (attached as .config) compiler: m68k-linux-gcc (GCC) 4.9.0 make.cross ARCH=m68k All errors (new ones prefixed by >>): net/built-in.o: In function `tls_set_sw_offload': >> (.text+0x732f8): undefined reference to `crypto_alloc_aead' net/built-in.o: In function `tls_set_sw_offload': >> (.text+0x7333c): undefined reference to `crypto_aead_setkey' net/built-in.o: In function `tls_set_sw_offload': >> (.text+0x73354): undefined reference to `crypto_aead_setauthsize' Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16tls: Depend upon INET not plain NET.David S. Miller
We refer to TCP et al. symbols so have to use INET as the dependency. ERROR: "tcp_prot" [net/tls/tls.ko] undefined! >> ERROR: "tcp_rate_check_app_limited" [net/tls/tls.ko] undefined! ERROR: "tcp_register_ulp" [net/tls/tls.ko] undefined! ERROR: "tcp_unregister_ulp" [net/tls/tls.ko] undefined! ERROR: "do_tcp_sendpages" [net/tls/tls.ko] undefined! Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-15tls: kernel TLS supportDave Watson
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: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com> Signed-off-by: Aviad Yehezkel <aviadye@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>