getmacbyip6 final cases are broken

[dkg]

in scapy/layers/inet6.py, the function getmacbyip6() ends with the following:

    res = neighsol(ip6, a, iff, chainCC=chainCC)

    if res is not None:
        if ICMPv6NDOptDstLLAddr in res:
            mac = res[ICMPv6NDOptDstLLAddr].lladdr
    else:
        mac = res.src
        conf.netcache.in6_neighbor[ip6] = mac
        return mac

    return None

This doesn't make sense. in the stanza following if statement, mac is set but never used (and None is returned). In the else stanza -- where res must be None -- it references a subfield of res , which is guaranteed to fail.

[gpotter2]

Hi ! This bug is fixed on the official scapy repo (secdev/scapy), which now supports Python 3. I recommend you to have a look https://github.com/secdev/scapy

Good day

[gpotter2]

@GhostOfGoes To avoid "confuse emojis", I'll provide the proof.

Here's current secdev/scapy implementation of the getmacbyip6 function: https://github.com/secdev/scapy/blob/0aeb049606bee9335e62afea58479915bd6e2344/scapy/layers/inet6.py#L116-L155

    res = neighsol(ip6, a, iff, chainCC=chainCC)

    if res is not None:
        if ICMPv6NDOptDstLLAddr in res:
            mac = res[ICMPv6NDOptDstLLAddr].lladdr
        else:
            mac = res.src
        conf.netcache.in6_neighbor[ip6] = mac
        return mac

    return None

What I'm saying is only the truth: this has INDEED been fixed on the main branch. Now please either contribute to scapy3k, or let me point out to users how outdated this fork is.

[GhostofGoes]

Thanks for clearing that up, and the link to the fix is appreciated. 😄

I just wasn't sure if the specific issues raised here were fixed in mainline scapy, due to the same message being used across issues.

[gpotter2]

Thanks for clarifying :)

[phaethon]

Issue fixed in the latest commit.

[gpotter2]

@phaethon Good luck