The Slipstream server currently binds its DNS listener to the wildcard IPv4 address (0.0.0.0:53), but there is no option to specify a particular local listen address.
This creates an unnecessary conflict with systemd-resolved and other local DNS services that commonly listen on 127.0.0.53:53.
Steps to reproduce
On a modern Linux system using the default systemd-resolved stub listener, verify:
For example:
UNCONN 0 0 127.0.0.53:53 0.0.0.0:* users:(("systemd-resolve",...))
Start Slipstream with its default DNS listen configuration:
slipstream-server \
--domain=example.com \
--target-address=127.0.0.1:1080The server attempts to bind:
and fails with:
bind(... sin_port=htons(53), sin_addr=inet_addr("0.0.0.0")) = -1 EADDRINUSE
Even though systemd-resolved is only bound to 127.0.0.53:53.
Expected behavior
The server should allow the administrator to specify the local address on which the DNS listener should bind, for example:
--dns-listen-address=1.2.3.4
This would allow:
Slipstream 1.2.3.4:53
systemd-resolved 127.0.0.53:53
to coexist without requiring changes to the system's DNS resolver configuration.
The existing --dns-listen-port option should remain independent of the listen address.
Actual behavior
The server binds to 0.0.0.0:53 and therefore conflicts with a listener on 127.0.0.53:53.
The administrator currently has to modify or disable systemd-resolved, introduce additional socket/proxy configuration, or otherwise work around the wildcard bind.
This is undesirable on Linux servers where systemd-resolved is part of the standard system configuration.
Suggested improvement
Add a command-line option such as:
--dns-listen-address ADDRESS
with the current wildcard behavior retained as the default for backwards compatibility.
At minimum, the option should accept an IPv4/IPv6 address. Supporting an interface name could be considered separately.
Being able to bind only to the intended public/local interface would also provide a useful security and deployment benefit by avoiding unnecessary wildcard exposure.
The Slipstream server currently binds its DNS listener to the wildcard IPv4 address (
0.0.0.0:53), but there is no option to specify a particular local listen address.This creates an unnecessary conflict with
systemd-resolvedand other local DNS services that commonly listen on127.0.0.53:53.Steps to reproduce
On a modern Linux system using the default
systemd-resolvedstub listener, verify:For example:
Start Slipstream with its default DNS listen configuration:
slipstream-server \ --domain=example.com \ --target-address=127.0.0.1:1080The server attempts to bind:
and fails with:
Even though
systemd-resolvedis only bound to127.0.0.53:53.Expected behavior
The server should allow the administrator to specify the local address on which the DNS listener should bind, for example:
This would allow:
to coexist without requiring changes to the system's DNS resolver configuration.
The existing
--dns-listen-portoption should remain independent of the listen address.Actual behavior
The server binds to
0.0.0.0:53and therefore conflicts with a listener on127.0.0.53:53.The administrator currently has to modify or disable
systemd-resolved, introduce additional socket/proxy configuration, or otherwise work around the wildcard bind.This is undesirable on Linux servers where
systemd-resolvedis part of the standard system configuration.Suggested improvement
Add a command-line option such as:
with the current wildcard behavior retained as the default for backwards compatibility.
At minimum, the option should accept an IPv4/IPv6 address. Supporting an interface name could be considered separately.
Being able to bind only to the intended public/local interface would also provide a useful security and deployment benefit by avoiding unnecessary wildcard exposure.