DTS testpmd and SCAPY integration

["Etelson, Gregory" <getelson@nvidia.com>]

Hello,

Consider an option to describe DTS test with testpmd and SCAPY plain text 
commands.

For example:

Scenario:
  - Configure UDP packet in SCAPY and a flow in testpmd.
  - Send UDP packet and validate testpmd output triggered by that packet.

```yaml
phase_0:
     name: CONFIGURATION
     tg: |
         udp_pkt = Ether()/IP()/UDP(sport=31)/Raw('== TEST ==')
         print('packet is ready')
     dut: |
         start
         set verbose 1
         flow create 0 ingress pattern eth / ipv4 / udp src is 31 / end actions queue index 1 / end
     result:
         dut: 'Flow rule #0 created'
         tg: 'packet is ready'

phase_1:
     name: SEND and VALIDATE
     tg: sendp(udp_pkt, iface=pf0)
     result:
         dut: '- RSS queue=0x1 -'
```

Test described as a sequence of phases.

Phase definition:
~~~~~~~~~~~~~~~~

```
<phase id>: # unique phase ID
     name: <phase name>                       # phase name
     <application ID (APP1)>: <APP1 commands> # application APP1 commands
     ...
     <application ID (APPy)>: <APPy commands> # application APPy commands
     ...
     <application ID (APPx)>: <APPx commands> # application APPx commands

     result:                # optional phase results verification section
         <application ID APPx>: <expected output>  # APPx expected output
         ...
         <application ID APPy>: <expected output>  # APPy expected output
```

- Application commands in a phase executed sequentially,
   in order of application IDs: <APPy> commands executed
   before <APPx> commands.

- Application results in a phase validated sequentially,
   in order of application IDs: <APPx> result validated
   before APPy result.

- Application result is a regular expression.


Test application definition:
~~~~~~~~~~~~~~~~~~~~~~~~~~~

```
<application ID>: # unique application ID
     agent:        # mandatory application type identifier: {testpmd|scapy}
     cmd:          # optional application command template
```

Example:

```yaml

dut:
     agent: testpmd
     cmd: 'dpdk-testpmd -a pci0 -- -i --rxq=4 --txq=4'

tg:
     agent: scapy
```

Test commands do not bound to a specific setup.
Therefore, testpmd commad line and SCAPY sendp() function use encoding
to describe relative interface position in a tested HBA.

PCI encoding scheme for testpmd:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

- PF PCI: `pciX`
   Example: `pci0: '0000:08:00.0'`


- PCI SR-IOV: `pciXvfY`
   Example: `pci0vf0: '0000:08:00.2'`

Network devices encoding scheme for SCAPY:
- PF: `pfX`
   Example: `pf0: enp8s0f0np0`


- PCI SR-IOV: `pfXvfY`
   Example: `pf0vf0: enp5s0f0v0`


- Network device representor: `pfXrfY`

      Example: `pf0rf0: enp5s0f0npf0vf0`


Test execution requires an additional file to describe tested setup.

Setup file format:
~~~~~~~~~~~~~~~~~

```
<application id>: # unique application ID
     host:         # hostname or IPvX address
     path:         # optional application path
     hba:          # optional HBA description
         pmd:      # PMD
         hw:       # HW type
```

Example:

```yaml
dut:
     host: 1.2.3.4
     path: /opt/dpdk.org/build/app
     hba:
         pmd: mlx5
         hw: mt4125
tg:
     host: ::1234
```

```yaml
dut:
     agent: testpmd
     cmd: 'dpdk-testpmd -a pci0 -- -i --rxq=4 --txq=4'
tg:
     agent: scapy

test:
     -
         phases: [ *ref_phase0 ]
         repeat: 1
     -
         phases: [ *ref_phase1 ]
         repeat: 3

phase_0: &ref_phase0
     name: CONFIGURATION
     tg: |
         udp_pkt = Ether()/IP()/UDP(sport=31)/Raw('== TEST ==')
         print('packet is ready')
     dut: |
         start
         set verbose 1
         flow create 0 ingress pattern eth / ipv4 / udp src is 31 / end actions queue index 1 / end
     result:
         dut: 'Flow rule #0 created'
         tg: 'packet is ready'

phase_1: &ref_phase1
     name: SEND and VALIDATE
     tg: sendp(udp_pkt, iface=pf0)
     result:
         dut: '- RSS queue=0x1 -'
```

The plain text format provides minimalistic and intuitive framework for DTS 
tests.
DTS can use plan text testpmd/scapy command format in addition to Python 
framework.

Regards,
Gregory