Issue #20258 has been updated by marek22k (Marek Küthe). `Socket::IPV6_MTU_DISCOVER` is also missing in the current Ruby version. ---------------------------------------- Bug #20258: Socket::IPV6_RECVERR for IPv6 https://bugs.ruby-lang.org/issues/20258#change-106920 * Author: marek22k (Marek Küthe) * Status: Open * Priority: Normal * ruby -v: ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-linux] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Hello, I am currently trying to receive ICMP error messages in Ruby. For IPv4 there is the `Socket::IP_RECVERR` flag, which can be set, but not for IPv6 (not found unter https://docs.ruby-lang.org/en/3.2/Socket/Constants.html for example), although this is provided for in POSIX (see https://manned.org/ipv6.7 under IPV6_RECVERR). The following can therefore be done for IPv4: ```rb sock.setsockopt Socket::IPPROTO_IP, Socket::IP_RECVERR, 1 ``` But not for IPv6: ``` sock.setsockopt Socket::IPPROTO_IPV6, Socket::IPV6_RECVERR, 1 ``` Could IPV6_RECVERR be included? Background: I want to try to build a traceroute implementation in Ruby. So far I have the following code: ```rb # frozen_string_literal: true # sharable_constant_value: literal require 'socket' sock = Socket.open(Socket::AF_INET6, Socket::SOCK_DGRAM, Socket::IPPROTO_UDP) sock.setsockopt Socket::IPPROTO_IPV6, Socket::IPV6_UNICAST_HOPS, 1 # sock.setsockopt Socket::IPPROTO_IPV6, Socket::IPV6_RECVERR, 1 dest = Socket.sockaddr_in 33435, '2a00:1450:4001:806::2003' pp sock.send "Test", 0, dest pp sock.recvmsg 1000, Socket::MSG_ERRQUEUE, 1000 ``` However, the `recvmsg` function is blocking (still receiving the ICMP error message) forever. I could imagine that this is due to the missing flag. Hence this request. -- https://bugs.ruby-lang.org/