Bug#964783: /usr/sbin/update-exim4.conf: Upgrade of package silently adds dc_local_interfaces to update-exim4.conf.conf

[Andreas Feldner]

Package: exim4-config
Version: 4.94-5
Severity: normal
File: /usr/sbin/update-exim4.conf

Dear Maintainer,

My requirement is to have no binding to a specified IP, therefore dc_local_interfaces must not be set.

When updating exim4 packages, including exim4-config, a line dc_local_interfaces is added,
in effect restricting access to localhost (ip4 and ip6).

I expect that an existing configuration is not effectively modified by an update script.



-- Package-specific info:
Exim version 4.94 #2 built 03-Jul-2020 06:20:07
Copyright (c) University of Cambridge, 1995 - 2018
(c) The Exim Maintainers and contributors in ACKNOWLEDGMENTS file, 2007 - 2018
Berkeley DB: Berkeley DB 5.3.28: (September 9, 2013)
Support for: crypteq iconv() IPv6 GnuTLS move_frozen_messages DANE DKIM DNSSEC Event I18N OCSP PIPE_CONNECT PRDR SOCKS TCP_Fast_Open
Lookups (built-in): lsearch wildlsearch nwildlsearch iplsearch cdb dbm dbmjz dbmnz dnsdb dsearch nis nis0 passwd
Authenticators: cram_md5 plaintext
Routers: accept dnslookup ipliteral manualroute queryprogram redirect
Transports: appendfile/maildir/mailstore autoreply lmtp pipe smtp
Fixed never_users: 0
Configure owner: 0:0
Size of off_t: 8
Configuration file search path is /etc/exim4/exim4.conf:/var/lib/exim4/config.autogenerated
Configuration file is /var/lib/exim4/config.autogenerated

-- System Information:
Debian Release: bullseye/sid
APT prefers testing
APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 5.6.0-2-amd64 (SMP w/4 CPU cores)
Kernel taint flags: TAINT_WARN, TAINT_FIRMWARE_WORKAROUND
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages exim4-config depends on:
ii adduser 3.118
ii debconf [debconf-2.0] 1.5.74

exim4-config recommends no packages.

exim4-config suggests no packages.

-- Configuration Files:
/etc/exim4/passwd.client [Errno 13] Keine Berechtigung: '/etc/exim4/passwd.client'

-- debconf information excluded

[Marc Haber]

Post by Andreas Feldner
My requirement is to have no binding to a specified IP, therefore dc_local_interfaces must not be set.

From update-exim4.conf(8) man page:

dc_local_interfaces
List of IP addresses the Exim daemon should listen on. If this
is left empty, Exim listens on all interfaces. Sets macro
MAIN_LOCAL_INTERFACES only if there is a non-empty value.

"left empty" is something other than "must not be set".

Try

dc_local_interface=""

instead of completely removing the value. Does that work?

Greetings
Marc