[Iftop-users] Fwd: iftop compiled against ipv4-only libpcap

[Michael Orlitzky]

I initially sent this to Paul & Chris because I am unable to read
(sorry). Forwarded to the list.

--

It's possible to compile libpcap without ipv6 via a configure flag. This
is the default at least on the hardened flavor of Gentoo, but users are
able to disable ipv6, too, and a lot of people do.

For the moment, this results in a runtime crash:

  iftop-1.0pre2 $ ./configure && make
  iftop-1.0pre2 $ sudo ./iftop
  Password:
  interface: eth0
  Unable to get IP address for interface: eth0
  ioctl(SIOCGIFADDR): Cannot assign requested address
  MAC address is: e0:cb:4e:c3:cb:6b
  set_filter_code: ip6 not supported

Ideally, iftop could check for ipv6 support in libpcap and fall back to
ipv4-only if it doesn't exist. On the other hand, that's a pain in your
butt, and introduces another configuration you have to support.

It "should be" (ha ha!) easy enough to fail ./configure if libpcap is
missing ipv6 support though. Unfortunately, autotools are dark magic to
me, so I can't provide any insights there.