Bug #20258: Socket::IPV6_RECVERR for IPv6 - Ruby master - Ruby Issue Tracking System

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Bug #20258

closed

Socket::IPV6_RECVERR for IPv6

Added by marek22k (Marek Küthe) 3 months ago. Updated 3 months ago.

Status:

Closed

Assignee:

Target version:

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

[ruby-core:116676]

Description

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:

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:

# 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.