From f01ae9f07574f8f0ca6c5635f11bcfbfeb3bd5a0 Mon Sep 17 00:00:00 2001 From: Amaury Denoyelle Date: Thu, 15 Feb 2024 18:43:44 +0100 Subject: [PATCH] DOC: quic: fix recommandation for bind on multiple address Documentation falsely mentions that binding on multiple addresses is forbidden for QUIC listeners. This is not the case. Moreover, this behavior is reliable when using destination address retrieval on receive via IP_PKTINFO, which allows to determine the proper source address for response. This should be backported up to 2.7. On 2.6 specific source address definition on sendmsg via IP_PKTINFO is not implemented. As such, bind on multiple addresses should remain forbidden for this release. --- doc/configuration.txt | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/doc/configuration.txt b/doc/configuration.txt index 1065e6098..1b35e0141 100644 --- a/doc/configuration.txt +++ b/doc/configuration.txt @@ -5383,10 +5383,12 @@ bind / [, ...] [param*] listen on. If unset, all IPv4 addresses of the system will be listened on. The same will apply for '*' or the system's special address "0.0.0.0". The IPv6 equivalent is '::'. Note - that if you bind a frontend to multiple UDP addresses you have - no guarantee about the address which will be used to respond. - This is why "0.0.0.0" addresses and lists of comma-separated - IP addresses have been forbidden to bind QUIC addresses. + that for UDP, specific OS features are required when binding + on multiple addresses to ensure the correct network interface + and source address will be used on response. In other way, + for QUIC listeners only bind on multiple addresses if running + with a modern enough systems. + Optionally, an address family prefix may be used before the address to force the family regardless of the address format, which can be useful to specify a path to a unix socket with