[pve-devel] applied: [PATCH proxmox-acme] fix #3390: standalone: explicitly bind to '::'

[Thomas Lamprecht]

On 12.05.21 21:04, Stoiko Ivanov wrote:
> This patch follows 2f8be3bfda203065b22e60862e5f98d831a46921 from
> pve-common:
> Instead of not specifying a listen address, we first try to bind on
> '::', which usually accepts connections for both ipv4 and ipv6,
> and fall back to '0.0.0.0' if this fails (if ipv6 is disabled via
> kernel commandline).
> 
> The arguments are the same for HTTP::Daemon as for IO::Socket::IP,
> since the former has IO::Socket::IP as base.
> 
> Additionally, by setting 'V6Only' explicitly to '0', the listening
> socket will also accept ipv4 connections, even if the sysctl
> 'net.ipv6.bindv6only' is set to 1 - the sysctl provides a default
> value, which can be overridden by a socket-option (see ipv6(7) -
> IPV6_ONLY).
> 
> setting this option results in the following setsockopt-call being
> added:
> setsockopt(3, SOL_IPV6, IPV6_V6ONLY, [0], 4) = 0
> 
> AFAICT the socket option is available and overridable on Linux > 2.4
> see [0] for an explanation of why this might not be wanted
> 
> Overriding the default setting set by an admin might be debateable,
> but considering that the http-listener for the ACME challenge is
> rather short-lived I think this is justified. The only other option
> would be to create 2 listening sockets and binding on both - which
> would mean reorganizing our perl-deamons to deal with multiple listen
> sockets.
> 
> quickly tested on a publicly reachable test-machine of mine with:
> * ipv6.domain.test (only AAAA record)
> * ip46.domain.test (both AAAA and A)
> * ipv4.domain.test (only A record)
> with:
> * sysctl net.ipv6.bindv6only=1 (for all 3 domains)
> * disabling ipv6 via kernel-commandline (only ipv4 tested)
> * disabling ipv6 via sysctl (only ipv4 tested)
> * only configuring an ipv6 address (only ipv6 tested)
> 
> [0] https://man.openbsd.org/inet6.4
> Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
> ---
>  src/PVE/ACME/StandAlone.pm | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
>

applied, thanks!