vpp/src/plugins/dpdk/ipsec/dpdk_crypto_ipsec_doc.md

# VPP IPSec implementation using DPDK Cryptodev API    {#dpdk_crypto_ipsec_doc}

This document is meant to contain all related information about implementation and usability.


## VPP IPsec with DPDK Cryptodev

DPDK Cryptodev is an asynchronous crypto API that supports both Hardware and Software implementations (for more details refer to [DPDK Cryptography Device Library documentation](http://dpdk.org/doc/guides/prog_guide/cryptodev_lib.html)).

When DPDK support is enabled and there are enough Cryptodev resources for all workers, the node graph is reconfigured by adding and changing default next nodes.

The following nodes are added:
* dpdk-crypto-input : polling input node, basically dequeuing from crypto devices.
* dpdk-esp-encrypt : internal node.
* dpdk-esp-decrypt : internal node.
* dpdk-esp-encrypt-post : internal node.
* dpdk-esp-decrypt-post : internal node.

Set new default next nodes:
* for esp encryption: esp-encrypt -> dpdk-esp-encrypt
* for esp decryption: esp-decrypt -> dpdk-esp-decrypt


### How to enable VPP IPSec with DPDK Cryptodev support

DPDK Cryptodev is supported in DPDK enabled VPP and by default only HW Cryptodev is supported.
To enable SW Cryptodev support (AESNI-MB-PMD and GCM-PMD), we need the following env option:

    vpp_uses_dpdk_cryptodev_sw=yes

A couple of ways to achive this:
* uncomment/add it in the platforms config (ie. build-data/platforms/vpp.mk)
* set the option when building vpp (ie. make vpp_uses_dpdk_cryptodev_sw=yes build-release)

When enabling SW Cryptodev support, it means that you need to pre-build the required crypto libraries needed by those SW Cryptodev PMDs. This requires nasm, see nasm section below.


### Crypto Resources allocation

VPP allocates crypto resources based on a best effort approach:
* first allocate Hardware crypto resources, then Software.
* if there are not enough crypto resources for all workers, the graph node is not modifed and the default VPP IPsec implementation based in OpenSSL is used. The following message is displayed:

      0: dpdk_ipsec_init: not enough Cryptodevs, default to OpenSSL IPsec


### Configuration example

To enable DPDK Cryptodev the user just need to provide cryptodevs int the
startup.conf.

Example startup.conf:

```
dpdk {
    socket-mem 1024,1024
    num-mbufs 131072
    dev 0000:81:00.0
    dev 0000:81:00.1
    enable-cryptodev
    dev 0000:85:01.0
    dev 0000:85:01.1
    vdev cryptodev_aesni_mb_pmd,socket_id=1
    vdev cryptodev_aesni_mb_pmd,socket_id=1
}
```

In the above configuration:
* 0000:85:01.0 and 0000:85:01.1 are crypto BDFs and they require the same driver binding as DPDK Ethernet devices but they do not support any extra configuration options.
* Two AESNI-MB Software Cryptodev PMDs are created in NUMA node 1.

For further details refer to [DPDK Crypto Device Driver documentation](http://dpdk.org/doc/guides/cryptodevs/index.html)

### Operational data

The following CLI command displays the Cryptodev/Worker mapping:

    show crypto device mapping [verbose]


### nasm

Building the DPDK Crypto Libraries requires the open source project nasm (The Netwide
Assembler) to be installed. Recommended version of nasm is 2.12.02. Minimum supported
version of nasm is 2.11.06. Use the following command to determine the current nasm version:

    nasm -v

CentOS 7.3 and earlier and Fedora 21 and earlier use unsupported versions
of nasm. Use the following set of commands to build a supported version:

    wget http://www.nasm.us/pub/nasm/releasebuilds/2.12.02/nasm-2.12.02.tar.bz2
    tar -xjvf nasm-2.12.02.tar.bz2
    cd nasm-2.12.02/
    ./configure
    make
    sudo make install