pfroute: filter out routing messages with RTF_LLDATA

[evverx]

those routing messages contain MAC addresses and end up without source candidates. Without this patch scapy fails with

>>> sr1(IPv6()/UDP(dport=5353)/DNS(qd=[DNSQR(qname='vbox.local',qtype='ALL')]))
...
File ~/scapy/scapy/layers/inet6.py:341, in IPv6.route(self)
    339 if isinstance(dst, (Gen, list)):
    340     dst = next(iter(dst))
--> 341 return conf.route6.route(dst, dev=scope)

File ~/scapy/scapy/route6.py:273, in Route6.route(self, dst, dev, verbose)
    271     if in6_isincluded(dst, p, plen):
    272         paths.append((plen, me, (iface, cset, gw)))
--> 273     elif (in6_ismlladdr(dst) and in6_islladdr(p) and in6_islladdr(cset[0])):  # noqa: E501
    274         paths.append((plen, me, (iface, cset, gw)))
    276 if not paths:

IndexError: list index out of range

>>> sr1(IPv6(dst='fe80::2%wm0')/ICMPv6EchoRequest())
Begin emission
ERROR: --- Error sending packets
Traceback (most recent call last):
  File "/root/scapy/scapy/sendrecv.py", line 280, in _sndrcv_snd
    self.hsent.setdefault(p.hashret(), []).append(p)
                          ~~~~~~~~~^^
  File "/root/scapy/scapy/layers/inet6.py", line 440, in hashret
    ss = inet_pton(socket.AF_INET6, ss)
  File "/root/scapy/scapy/pton_ntop.py", line 92, in inet_pton
    return socket.inet_pton(af, addr)
           ~~~~~~~~~~~~~~~~^^^^^^^^^^
OSError: illegal IP address string passed to inet_pton

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.82%. Comparing base (190b4ba) to head (5946a21).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #5168   +/-   ##
=======================================
  Coverage   80.81%   80.82%           
=======================================
  Files         390      390           
  Lines       97736    97740    +4     
=======================================
+ Hits        78986    78994    +8     
+ Misses      18750    18746    -4     

Files with missing lines	Coverage Δ
scapy/arch/bpf/pfroute.py	92.73% <100.00%> (+0.08%)	⬆️

... and 5 files with indirect coverage changes

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• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[evverx]

Also with this patch applied the following tests no longer fail on NetBSD

###(003)=[failed] HSRP V2 with IPv6 and default text auth - build & dissection
###(051)=[failed] Layer binding
###(109)=[failed] ICMPv6MRD_Advertisement - Basic Dissection and overloading mechanisms
###(112)=[failed] ICMPv6MRD_Solicitation - Basic Dissection and overloading mechanisms
###(115)=[failed] ICMPv6MRD_Termination - Basic Dissection and overloading mechanisms
###(172)=[failed] ICMPv6ND_NS - IPv6 layer fields overloading
###(177)=[failed] ICMPv6ND_NS - IPv6 layer fields overloading
###(419)=[failed] Test NDP_Attack_Fake_Router
###(000)=[failed] ICMPv6NDOptRsaSig build and dissection
###(001)=[failed] ICMPv6NDOptCGA build and dissection
###(002)=[failed] ICMPv6NDOptTmstp build and dissection
###(003)=[failed] ICMPv6NDOptNonce build and dissection