Read and Write Registers With the CLI

+--+      +--+     ++-+
|h1+------+s1+-----+h2+
		      +
		       |
		       +
		       h3
		       +
+--+      +-++     +--+

Introduction

This example shows how to read and write registers using the Runtime CLI.

You can also run into the register by sending packets to the switch. For every packet that the switch receives it will save in the register the content of the TOS field at the same index than the TOS. E.g register[TOS] = TOS.

How to run

Start topology

sudo p4run

Send a packet with a modified tos field from h1:

mx h1
python send.py 10.0.1.2 50

Open CLI

simple_switch_CLI --thrift-port 9090

Read the register number 50:

RuntimeCmd: register_read MyIngress.tos_register 50
MyIngress.tos_register[50]= 50

Read and write from the CLI

Set register values

RuntimeCmd: register_write tos_register 0 10
RuntimeCmd: register_write tos_register 1 20
RuntimeCmd: register_write tos_register 2 30
RuntimeCmd: register_write tos_register 3 40
RuntimeCmd: register_write tos_register 4 50

Read Registers

tos_register[0]= 10                            
RuntimeCmd: register_read  tos_register 1      
tos_register[1]= 20                            
RuntimeCmd: register_read  tos_register 2      
tos_register[2]= 30

Read bulk

register_read tos_register