Bug#1064539: systemd: DHCPPrefixDelegation does not allow zero value in Token=

[Fabian Müller]

Package: systemd
Version: 252.19-1~deb12u1
Severity: normal
Tags: ipv6
X-Debbugs-Cc: fmu+debian at never-afk.de

Dear Maintainer,


   * What led up to the situation?

I wanted systemd-networkd to select the first address (zero) from the ipv6
prefix that was delegated to me. My provider (Vodafone Kabel / Germany) offers
me a /56 prefix via prefix delegation.

My .network file looks like this:

[Match]
Name=enp1s0

[Network]
IPv6AcceptRA=yes
DHCP=yes
DHCPPrefixDelegation=yes

[DHCPv6]
PrefixDelegationHint=::/56
UseDNS=no
UseAddress=no

[DHCPPrefixDelegation]
Token=static:::


   * What exactly did you do (or not do) that was effective (or
     ineffective)?

I tried to set the "Token=" option in the [DHCPPrefixDelegation] section of my
.network file as follows:

[DHCPPrefixDelegation]
Token=static:::

   * What was the outcome of this action?

The resulting ipv6 address is selects via eui64 instead of static.
So i get a address like this 2001:db8::a60:6eff:feda:858a/64

   * What outcome did you expect instead?

I expected the address to be zero. More like this: 2001:db8::/64 (which is a
valid ipv6 address).

I also tried the following values:
Token=static:::0 # does not work
Token=:: # does not work
Token=static:::0000 # does not work
Token=static:::1 # works as expected, but is not what i want, address would be
2001:db8::1/64


-- Package-specific info:

-- System Information:
Debian Release: 12.4
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 6.1.0-15-amd64 (SMP w/4 CPU threads; PREEMPT)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages systemd depends on:
ii  libacl1            2.3.1-3
ii  libaudit1          1:3.0.9-1
ii  libblkid1          2.38.1-5+b1
ii  libc6              2.36-9+deb12u3
ii  libcap2            1:2.66-4
ii  libcryptsetup12    2:2.6.1-4~deb12u1
ii  libfdisk1          2.38.1-5+b1
ii  libgcrypt20        1.10.1-3
ii  libkmod2           30+20221128-1
ii  liblz4-1           1.9.4-1
ii  liblzma5           5.4.1-0.2
ii  libmount1          2.38.1-5+b1
ii  libp11-kit0        0.24.1-2
ii  libseccomp2        2.5.4-1+b3
ii  libselinux1        3.4-1+b6
ii  libssl3            3.0.11-1~deb12u2
ii  libsystemd-shared  252.19-1~deb12u1
ii  libsystemd0        252.19-1~deb12u1
ii  libzstd1           1.5.4+dfsg2-5
ii  mount              2.38.1-5+b1

Versions of packages systemd recommends:
ii  dbus [default-dbus-system-bus]   1.14.10-1~deb12u1
ii  systemd-timesyncd [time-daemon]  252.19-1~deb12u1

Versions of packages systemd suggests:
ii  libfido2-1            1.12.0-2+b1
ii  libqrencode4          4.1.1-1
pn  libtss2-esys-3.0.2-0  <none>
pn  libtss2-mu0           <none>
pn  libtss2-rc0           <none>
ii  policykit-1           122-3
ii  polkitd               122-3
pn  systemd-boot          <none>
ii  systemd-container     252.19-1~deb12u1
pn  systemd-homed         <none>
ii  systemd-resolved      252.19-1~deb12u1
pn  systemd-userdbd       <none>

Versions of packages systemd is related to:
ii  dbus-user-session  1.14.10-1~deb12u1
pn  dracut             <none>
ii  initramfs-tools    0.142
pn  libnss-systemd     <none>
ii  libpam-systemd     252.19-1~deb12u1
ii  udev               252.19-1~deb12u1

-- no debconf information