Using in-band `ipmbdev` interface

[mahendrapaipuri]

Hello,

Thanks a lot for this lib. It helped me to understand the IPMI spec better.

I am trying to make the in-band ipmbdev interface work with the library without much success. I am interested in dcmi power readings and I am using the following script:

$ cat ipmi.py
import sys
import logging

import pyipmi
import pyipmi.interfaces

# Set logging to DEBUG
pyipmi.logger.set_log_level(logging.DEBUG)


def main():

    interface = pyipmi.interfaces.create_interface('ipmbdev', port='/dev/ipmi0')
    ipmi = pyipmi.create_connection(interface)
    ipmi.session.establish()
    ipmi.target = pyipmi.Target(ipmb_address=0x20)

    rsp = ipmi.get_power_reading(1)

    print('Power Reading')
    print('  current:   {}'.format(rsp.current_power))
    print('  minimum:   {}'.format(rsp.minimum_power))
    print('  maximum:   {}'.format(rsp.maximum_power))
    print('  average:   {}'.format(rsp.average_power))
    print('  timestamp: {}'.format(rsp.timestamp))
    print('  period:    {}'.format(rsp.period))
    print('  state:     {}'.format(rsp.reading_state))


if __name__ == '__main__':
    main() 

The device file exists with proper permissions on the machine I am testing this script:

 ls -la /dev/ipmi0
crw----rw- 1 root root 246, 0 Oct 15 07:09 /dev/ipmi0

I get timeout error when I execute the script:

$ python ipmi.py 
Traceback (most recent call last):
  File "ipmi.py", line 31, in <module>
    main() 
  File "ipmi.py", line 18, in main
    rsp = ipmi.get_power_reading(1)
  File "/home/mpaipuri/miniconda3/envs/test/lib/python3.8/site-packages/pyipmi/dcmi.py", line 35, in get_power_reading
    rsp = self.send_message_with_name('GetPowerReading',
  File "/home/mpaipuri/miniconda3/envs/test/lib/python3.8/site-packages/pyipmi/__init__.py", line 212, in send_message_with_name
    rsp = self.send_message(req)
  File "/home/mpaipuri/miniconda3/envs/test/lib/python3.8/site-packages/pyipmi/__init__.py", line 196, in send_message
    rsp = self.interface.send_and_receive(req)
  File "/home/mpaipuri/miniconda3/envs/test/lib/python3.8/site-packages/pyipmi/interfaces/ipmbdev.py", line 162, in send_and_receive
    rx_data = self._send_and_receive(target=req.target,
  File "/home/mpaipuri/miniconda3/envs/test/lib/python3.8/site-packages/pyipmi/interfaces/ipmbdev.py", line 132, in _send_and_receive
    raise IpmiTimeoutError()
pyipmi.errors.IpmiTimeoutError

I can verify the device file is working using ipmitool:

$ ipmitool -vvvvvv dcmi power reading
Using ipmi device 0
Set IPMB address to 0x20
OpenIPMI Request Message Header:
  netfn     = 0x6
  cmd       = 0x1
Sending request 0x1 to System Interface
Got message:  type      = 1
  channel   = 0xf
  msgid     = 0
  netfn     = 0x7
  cmd       = 0x1
  data_len  = 16
  data      = 002081026502dfa202000001000f4141
Iana: 674
Running Get PICMG Properties my_addr 0x20, transit 0, target 0
OpenIPMI Request Message Header:
  netfn     = 0x2c
  cmd       = 0x0
OpenIPMI Request Message Data (1 bytes)
 00
Sending request 0x0 to System Interface
Got message:  type      = 1
  channel   = 0xf
  msgid     = 1
  netfn     = 0x2d
  cmd       = 0x0
  data_len  = 1
  data      = c1
Error response 0xc1 from Get PICMG Properities
Running Get VSO Capabilities my_addr 0x20, transit 0, target 0
OpenIPMI Request Message Header:
  netfn     = 0x2c
  cmd       = 0x0
OpenIPMI Request Message Data (1 bytes)
 03
Sending request 0x0 to System Interface
Got message:  type      = 1
  channel   = 0xf
  msgid     = 2
  netfn     = 0x2d
  cmd       = 0x0
  data_len  = 1
  data      = c1
Invalid completion code received: Invalid command
Acquire IPMB address
Discovered IPMB address 0x0
Interface address: my_addr 0x20 transit 0:0 target 0x20:0 ipmb_target 0

OpenIPMI Request Message Header:
  netfn     = 0x2c
  cmd       = 0x2
OpenIPMI Request Message Data (4 bytes)
 dc 01 00 00
Sending request 0x2 to System Interface
Got message:  type      = 1
  channel   = 0xf
  msgid     = 3
  netfn     = 0x2d
  cmd       = 0x2
  data_len  = 19
  data      = 00dc63004d00d1006a0054180e67e803000040

    Instantaneous power reading:                    99 Watts
    Minimum during sampling period:                 77 Watts
    Maximum during sampling period:                209 Watts
    Average power reading over sample period:      106 Watts
    IPMI timestamp:                           Tue Oct 15 07:23:00 2024
    Sampling period:                          00000001 Seconds.
    Power reading state is:                   activated

I am not an expert in the IPMI spec but I can see that ipmitool is sending only netfn and cmd in the headers where as python-ipmi sends more headers. I have checked that the payload by both ipmitool and python-ipmi matches.

Could you please help me out or give me directions where I need to look to make it work?

Cheers!