Bug #21512: Socket.tcp_with_fast_fallback('example.com', 80, '127.0.0.1') fails with unknown socket domain: ipv4 (SocketError) - Ruby
closed
Socket.tcp_with_fast_fallback('example.com', 80, '127.0.0.1') fails with unknown socket domain: ipv4 (SocketError)
1
ruby -v:
ruby 3.5.0dev (2025-07-13T04:37:15Z master f03cc0b514) +PRISM [x86_64-linux]
Description
The following code is expected to open a socket bound to the local IPv4 interface, but raises an SocketError.
require 'socket'
Socket.tcp_with_fast_fallback('localhost', 8080, '127.0.0.1')
Expected behavior: Returns a Socket object
Actuai behavior: Causes a SocketError (unknown socket domain: ipv4)
I believe this is because Socket.tcp_with_fast_fallback is calling Addrinfo.getaddrinfo with :ipv4 / :ipv6 as its third argument, instead of Socket::AF_INET / Socket::AF_INET6.
https://github.com/ruby/ruby/blob/b2a7b7699261d2a4ef8a9d5d38d3fb9dc99c8253/ext/socket/lib/socket.rb#L707
- Status changed from Open to Assigned
- Assignee set to shioimm (Misaki Shioi)
- Status changed from Assigned to Closed
Applied in changeset git|b896f80598cc096c84d57b2024813e994637af3b.
[Bug #21512] Socket.tcp_with_fast_fallback: Pass proper addr family to getaddrinfo (#13878)
Socket.tcp_with_fast_fallback: Pass proper addr family to getaddrinfo
Addrinfo.getaddrinfo expects Socket::AF_INET or Socket::AF_INET6 as its
third argument (family). However Socket.tcp_with_fast_fallback was
incorrectly passing :ipv4 or :ipv6.
Repro:
require 'socket'
Socket.tcp_with_fast_fallback('example.com', 80, '127.0.0.1')
Expected behavior: Returns a Socket object
Actual: Raises unknown socket domain: ipv4 (SocketError)
I merged this fix. Thank you!