Incorrect External Access Warning about octoprint

[foosel]

Fixed by the above commit, ready for 1.10.1.

As explained in #5006, I've decide to go with an either/or approach here with regards what is fetched from the address dict. netifaces2 might at some point change this back from mask to netmask to be fully compatible, or we might run into old netifaces installations out there at some point that end up getting loaded instead of netifaces2 (python can be a bit weird here), so better support both.

[cp2004]

Note: I did not include the systeminfo bundle here as it contains some public IPv6 addresses and also a domain name that I do not want to be shown publicly in the github issues. (I can share privately if needed or I can censor them.)

This may well be the cause of the warning. If your network is setup so that your access appears to be from a public IPv6 address, then OctoPrint will trigger the warning.

I'm not sure of what changed here in relation to OctoPrint 1.10.0, but there was also this report on the forum.

https://community.octoprint.org/t/how-is-external-access-checked/58170?u=charlie_powell

[steve1515]

My systems (both client and OctoPrint server) have IPv6 addresses allocated from a public range as that's pretty standard with IPv6.

I would think OctoPrint could check it's hosts directly attached IP networks and compare it to the client. If the networks match, then it could consider it a local connection.

Another solution might be to have a place to add trusted networks. In this case, I would manually add my local network ranges and OctoPrint would consider them local if a client is connecting from them.

[jneilliii]

Possibly validate against localNetworks in config.yaml and if there's a match don't prompt.

https://docs.octoprint.org/en/master/configuration/config_yaml.html#access-control

[steve1515]

I started to look through the code and I think there might be a bigger issue here.
It looks like the code does attempt to get a list of the directly attached network interfaces on the OctoPrint server, but this code seems to be failing.
My initial testing is showing that calls to subnets.append(to_ipnetwork(v4)) and subnets.append(to_ipnetwork(v6)) in the following locations are always throwing exceptions:

OctoPrint/src/octoprint/util/net.py

Line 74 in fed2dd7

subnets.append(to_ipnetwork(v4))

OctoPrint/src/octoprint/util/net.py

Line 86 in fed2dd7

subnets.append(to_ipnetwork(v6))

I'll keep looking, but I think this might be the cause of the issue.

[steve1515]

The problem is specifically this line:

OctoPrint/src/octoprint/util/net.py

Line 60 in fed2dd7

prefix = address["netmask"]

The element netmask does not exist but mask does. Changing to mask seems to make everything happy.

Here's the strange thing...
netifaces.ifaddresses() returns an object containing mask, but any documentation I can find shows that netmask is supposed to be correct.
One example here: https://pypi.org/project/netifaces/

Anyone have any thoughts on the correct way to proceed here?

[steve1515]

Even a little more confusing is it seems the source code for netifaces does actually use netmask. See here: https://github.com/al45tair/netifaces/blob/53fcdb6e5dccc84f6734939cfee1a95d3f470d7b/netifaces.c#L996

I'm really not sure why I'm seeing mask instead of netmask... 😕

[steve1515]

Even more findings...
If I create a simple script like the one below, when I run it with python3 in OctoPrint's venv I get objects with mask, but if I run it outside of the venv as my regular linux user I get the expected netmask. I checkd that netifaces is version 0.11.0 in both locations using pip list | grep netifaces.

This seems strange to me. Is OctoPrint using some kind of custom modified build of netifaces?

import os
import socket
import sys
import netifaces

for interface in netifaces.interfaces():
    addrs = netifaces.ifaddresses(interface)
    for v4 in addrs.get(socket.AF_INET, ()):
        try:
            print(f'v4 subnet = {v4}')
        except Exception:
            print("FAILED v4")

    for v6 in addrs.get(socket.AF_INET6, ()):
        try:
            print(f'v6 subnet = {v6}')
        except Exception:
            print("FAILED v6")

[cp2004]

OctoPrint switched to netifaces2 in 1.10.0

OctoPrint/setup.py

Line 55 in fed2dd7

"netifaces2>=0.0.21,<0.1",

Good catch!

[cp2004]

@ManuelMcLure ran into this issue as well - netifaces2 is returning mask instead of netmask.

https://discord.com/channels/704958479194128507/708230829050036236/1232770439416381463

Should at least be a simple fix in OctoPrint, and can be part of a bugfix release for 1.10 when that is required.

[GitIssueBot]

This issue has been mentioned on OctoPrint Community Forum. There might be relevant details there:

https://community.octoprint.org/t/how-is-external-access-checked/58170/5

[steve1515]

Aha!!! That means we should change the code to use mask I believe.

I could try to do a PR some time this week.

[ManuelMcLure]

What I did in my plugin was to try mask first and then tried netmask as a fallback, since the plugin might still be running on 1.9.x. For OP core it doesn't make sense to do it that way, I think.

[steve1515]

I'm not as familiar with python as I am with other languages. Is there any potential issue with both netifaces and netifaces2 being installed in the venv? How do we ensure that netifaces2 is loaded when both are found?

[jneilliii]

I think you could patch locally via SSH to the pi and edit the file directly.

nano ~/oprint/lib/python3.9/site-packages/octoprint/util/net.py

go to line 60 and change it from address["netmask"] to address["mask"]

ctrl+s to save ctrl+x to exit and then restart OctoPrint.