Feature #17524: resolv: add some more characters in IPv6 link local zone id

• Status: Assigned
• Priority: Normal
• Assignee: akr (Akira Tanaka)
• Target version: -

[no6v (Nobuhiro IMAI)]

According to RFC6874, IPv6 link local zone id is:

   ZoneID = 1*( unreserved / pct-encoded )

where unreserved in RFC3986 is as follow.

   unreserved  = ALPHA / DIGIT / "-" / "." / "_" / "~"

Actually, docker can create such an interface.

$ docker network create --ipv6 --subnet fe80::/64 --opt com.docker.network.bridge.name=ruby_3.0.0-1 ruby
$ ruby -rsocket -e 'p Socket.ip_address_list.last'
#<Addrinfo: fe80::1%ruby_3.0.0-1>

This makes TestResolvAddr#test_valid_socket_ip_address_list failure.
Supporting a pct-encoded may be overwork, but adding the all of unreserved to

• Resolv::IPv6::Regex_8HexLinkLocal and
• Resolv::IPv6::Regex_CompressedHexLinkLocal

sounds reasonable for me. What do you think?

[jeremyevans0 (Jeremy Evans)]

• Assignee set to akr (Akira Tanaka)
• Status changed from Open to Assigned

This seems reasonable to me. I chose a more conservative approach in the initial implementation, but we've already had to expand it once for s390, and if adding the rest of the unreserved characters fixes docker, we should do that.

I've submitted a pull request upstream for this: https://github.com/ruby/resolv/pull/2

[no6v (Nobuhiro IMAI)]

Thanks for your comment and pull request. That is what I expected.
I'm looking forward it to be merged.

[jaruga (Jun Aruga)]

I just faced this issue where cni-podman0 including - is used as string matching with Resolv::IPv6::Regex_CompressedHexLinkLocal.

$ ruby -rsocket -e 'p Socket.ip_address_list[8]'
#<Addrinfo: fe80::9856:24ff:fe1b:f759%cni-podman0>