Question about option 124 usage
Shawn R. wrote us:
The arguments to the error messages for HOOKS_CALLOUT_ERROR and HOOKS_CALLOUT_EXCEPTION are in the wrong order. The first two argument (index and hook point) provided by the code (callout_manager.cc:call_callouts() are swapped compared to the messages.
You may want to change the order in the message to make them consistent with HOOKS_CALLOUT_CALLED.
The above is being dealt with on #2020 (closed).
He came across this while in the process of troubleshooting a customer issue for his employers. Of that issue, he writes:
I'm still investigating but there may also be an issue with the option library's presentation code for option 124. We have a customer that has a client sending us the following for option 124
7c = 124 05 = length 5 00 00 04 03 = 4 byte enterprise id 00 = length opaque data (0)
and we are attempting to manipulate it in a hook and getting the following error (note this also shows the argument swap issue described above)
ERROR [kea-dhcp4.callouts.140636175726464] HOOKS_CALLOUT_EXCEPTION exception thrown by callout on hook 1 registered by library with index leases4_committed (callout address 0x7fe8644c9845): unable to obtain hexadecimal representation of option 124: failed to create on-wire format of the opaque data field, because the field appears to be empty (callout duration: 1.663 ms)