PXEd[pxed] CRITICAL: Padding overflow
Lionel-snoopy63 opened this issue · comments
Hello. I need your help because I try to use bootp protocol but each time I get an error message.
I've tried to dig inside the code but I don't know how to fix this issue. You will find below the output. Thanks in advance for any help.
17:37:18 PXEd[daemons] INFO: pybootd-1.7.1
<pybootd.util.EasyConfigParser object at 0x000001D904CDE1C8>
17:37:06 PXEd[pxed] INFO: Using ifname:{A5E9C4C2-457E-4842-87E8-CF9297BADB4D}, mask:255.255.255.0, net:192.168.1.0, server:192.168.1.58
17:37:06 PXEd[pxed] INFO: Listening to 0.0.0.0:67
17:37:18 PXEd[pxed] INFO: Sender: ('0.0.0.0', 68) on socket ('0.0.0.0', 67)
17:37:18 PXEd[pxed] INFO: PXE UUID not present in request
17:37:18 PXEd[pxed] INFO: 00:0A:86:A2:2F:3E access is authorized, request will be satisfied
17:37:18 PXEd[pxed] INFO: Client needs its address
17:37:18 PXEd[pxed] INFO: Reply to: 192.168.1.255:68
17:37:18 PXEd[pxed] INFO: Offering lease for MAC 00:0A:86:A2:2F:3E: IP 192.168.1.65
17:37:18 PXEd[pxed] INFO: Sender: ('0.0.0.0', 68) on socket ('0.0.0.0', 67)
17:37:18 PXEd[pxed] CRITICAL: Padding overflow
Hi. Can you enable DEBUG traces?
Which kind of DHCP client is it?
Which kind of DHCP client is it?
Client is an EtherNet communication module (this module is installed on a drive to be able to communicate with a PLC). When the module is out the box, bootp protocol is enable.
Hi. Can you enable DEBUG traces?
Yes of course. See below the output.
C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108>pybootd.py -c C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108\pybootd\etc\pybootd.ini -p -d
16:01:24 PXEd[daemons] INFO: pybootd-1.7.1
16:01:24 PXEd[pxed] INFO: Using ifname:{A5E9C4C2-457E-4842-87E8-CF9297BADB4D}, mask:255.255.255.0, net:192.168.1.0, server:192.168.1.58
16:01:24 PXEd[pxed] INFO: Listening to 0.0.0.0:67
16:01:30 PXEd[pxed] INFO: Sender: ('0.0.0.0', 68) on socket ('0.0.0.0', 67)
16:01:30 PXEd[pxed] INFO: PXE UUID not present in request
16:01:30 PXEd[pxed] INFO: 00:0A:86:A2:2F:3E access is authorized, request will be satisfied
16:01:30 PXEd[pxed] INFO: Client needs its address
16:01:30 PXEd[pxed] INFO: Reply to: 192.168.1.255:68
16:01:30 PXEd[pxed] INFO: Offering lease for MAC 00:0A:86:A2:2F:3E: IP 192.168.1.25
16:01:30 PXEd[pxed] INFO: Sender: ('0.0.0.0', 68) on socket ('0.0.0.0', 67)
16:01:30 PXEd[pxed] CRITICAL: Padding overflow
Traceback (most recent call last):
File "C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108\pybootd\pxed.py", line 279, in start
self.handle(sock, addr, data)
File "C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108\pybootd\pxed.py", line 358, in handle
options = self.parse_options(tail)
File "C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108\pybootd\pxed.py", line 297, in parse_options
raise ValueError('Padding overflow')
ValueError: Padding overflow
16:01:35 PXEd[pxed] INFO: Sender: ('0.0.0.0', 68) on socket ('0.0.0.0', 67)
16:01:35 PXEd[pxed] CRITICAL: Padding overflow
Traceback (most recent call last):
File "C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108\pybootd\pxed.py", line 279, in start
self.handle(sock, addr, data)
File "C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108\pybootd\pxed.py", line 358, in handle
options = self.parse_options(tail)
File "C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108\pybootd\pxed.py", line 297, in parse_options
raise ValueError('Padding overflow')
ValueError: Padding overflow
Aborting...
C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108>
The error would be raised when the DHCP data received from the client is malformed - or there is a bug in pybootd :-)
in handle(self, sock, addr, data), add a log trace to dump the received data, such as
def handle(self, sock, addr, data):
self.log.info('Sender: %s on socket %s' % (addr, sock.getsockname()))
self.log.info('DHCP data (%d): %s', len(data), hexlify(data).decode())
# ...
and post the results
The error would be raised when the DHCP data received from the client is malformed - or there is a bug in pybootd :-)
in
handle(self, sock, addr, data), add a log trace to dump the received data, such asdef handle(self, sock, addr, data): self.log.info('Sender: %s on socket %s' % (addr, sock.getsockname())) self.log.info('DHCP data (%d): %s', len(data), hexlify(data).decode()) # ...and post the results
Below the results
18:14:07 PXEd[daemons] INFO: pybootd-1.7.1
18:14:07 PXEd[pxed] INFO: Using ifname:{A5E9C4C2-457E-4842-87E8-CF9297BADB4D}, mask:255.255.255.0, net:192.168.1.0, server:192.168.1.58
18:14:07 PXEd[pxed] INFO: Listening to 0.0.0.0:67
18:14:14 PXEd[pxed] INFO: Sender: ('0.0.0.0', 68) on socket ('0.0.0.0', 67)
18:14:14 PXEd[pxed] INFO: DHCP data (300): 010106002233445a0000800000000000000000000000000000000000000a86a22f3e0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000063825363ff0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
18:14:14 PXEd[pxed] INFO: PXE UUID not present in request
18:14:14 PXEd[pxed] INFO: 00:0A:86:A2:2F:3E access is authorized, request will be satisfied
18:14:14 PXEd[pxed] INFO: Client needs its address
18:14:14 PXEd[pxed] INFO: Reply to: 192.168.1.255:68
18:14:14 PXEd[pxed] INFO: Offering lease for MAC 00:0A:86:A2:2F:3E: IP 192.168.1.25
18:14:14 PXEd[pxed] INFO: Sender: ('0.0.0.0', 68) on socket ('0.0.0.0', 67)
18:14:14 PXEd[pxed] INFO: DHCP data (548): 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
18:14:14 PXEd[pxed] CRITICAL: Padding overflow
Traceback (most recent call last):
File "C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108\pybootd\pxed.py", line 279, in start
self.handle(sock, addr, data)
File "C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108\pybootd\pxed.py", line 359, in handle
options = self.parse_options(tail)
File "C:\Users\Fxxx\AppData\Local\Programs\Python\Python37\Test_pybootd_20200108\pybootd\pxed.py", line 297, in parse_options
raise ValueError('Padding overflow')
ValueError: Padding overflow
Wow, never saw that much (useless) padding.
I’ll check tomorrow this part of the code, even if the client is dumb, pybootd should be able to cope with it. Thanks for the traces, it helps a lot to understand/reproduce the issue.
Quick update: I've started writing a unit test so I can reproduce this error from the hex data you captured.
I've tested your update and that works well. See the result below for your info.
Thanks a lot for your help.
18:02:10 PXEd[daemons] INFO: pybootd-1.7.2
18:02:10 PXEd[pxed] INFO: Using ifname:{A5E9C4C2-457E-4842-87E8-CF9297BADB4D}, mask:255.255.255.0, net:192.168.1.0, server:192.168.1.58
18:02:10 PXEd[pxed] INFO: Listening to 0.0.0.0:67
18:02:19 PXEd[pxed] INFO: Sender: ('0.0.0.0', 68) on socket ('0.0.0.0', 67)
18:02:19 PXEd[pxed] INFO: PXE UUID not present in request
18:02:19 PXEd[pxed] INFO: 00:0A:86:A2:2F:3E access is authorized, request will be satisfied
18:02:19 PXEd[pxed] INFO: Client needs its address
18:02:19 PXEd[pxed] INFO: Reply to: 192.168.1.255:68
18:02:19 PXEd[pxed] INFO: Offering lease for MAC 00:0A:86:A2:2F:3E: IP 192.168.1.25
18:02:19 PXEd[pxed] INFO: Sender: ('0.0.0.0', 68) on socket ('0.0.0.0', 67)
18:02:19 PXEd[pxed] INFO: PXE UUID not present in request
18:02:19 PXEd[pxed] INFO: 00:0A:86:A2:2F:3E access is authorized, request will be satisfied
18:02:19 PXEd[pxed] INFO: Client needs its address
18:02:19 PXEd[pxed] INFO: Lease for MAC 00:0A:86:A2:2F:3E already defined as IP 192.168.1.25
18:02:19 PXEd[pxed] INFO: Reply to: 192.168.1.255:68
18:02:19 PXEd[pxed] INFO: New lease for MAC 00:0A:86:A2:2F:3E: IP 192.168.1.25
Aborting...
Ok thanks for letting me know.