superseded-by: https://lore.proxmox.com/pve-devel/[email protected]/T/#m344301ba0d2a23f23715a1ce7a5c0aa3cbc6da16
On 2026-09-05 11:21, Hannes Laimer wrote: > Mapping edits through the API only wrote the IPAM record and the > cache, the dhcp backend was never told, so dnsmasq kept serving > stale reservations until a later guest start in the zone happened > to sweep them. The same held for a guest whose NIC moved to another > bridge, the old records were released and new ones allocated without > the backend hearing of either. > > Push the MAC's current answer after every record change, removing > the old reservation first, since a re-add alone leaves a stale > address behind when only one of the MAC's two addresses was > deleted. The push is best effort, the record write stays > authoritative. Mapping removal was dispatched to the plugins but > implemented nowhere and never called, add the dnsmasq > implementation for it. > > Signed-off-by: Hannes Laimer <[email protected]> > --- > > v2: > - one push helper in the dhcp dispatcher instead of the push repeated > in the ips API handlers > - the guest allocation and release paths push too, so a bridge change > on a running guest reaches the backend > - a guest start pushes once, only for what it allocated > - the update goes through a plugin hook, remove then add stays the > default for dnsmasq > > src/PVE/API2/Network/SDN/Ips.pm | 7 +++++++ > src/PVE/Network/SDN/Dhcp.pm | 21 +++++++++++++++++++ > src/PVE/Network/SDN/Dhcp/Dnsmasq.pm | 32 ++++++++++++++++++++++++++++- > src/PVE/Network/SDN/Dhcp/Plugin.pm | 13 ++++++++++++ > src/PVE/Network/SDN/Vnets.pm | 17 ++++++++++----- > 5 files changed, 84 insertions(+), 6 deletions(-) > > diff --git a/src/PVE/API2/Network/SDN/Ips.pm b/src/PVE/API2/Network/SDN/Ips.pm > index 5ff05e7..d7b682d 100644 > --- a/src/PVE/API2/Network/SDN/Ips.pm > +++ b/src/PVE/API2/Network/SDN/Ips.pm > @@ -46,6 +46,8 @@ __PACKAGE__->register_method({ > eval { PVE::Network::SDN::Vnets::del_ip($vnet, $ip, '', $mac); }; > die "$@\n" if $@; > > + PVE::Network::SDN::Dhcp::update_mapping($vnet, $mac); > + > return undef; > }, > }); > @@ -82,6 +84,8 @@ __PACKAGE__->register_method({ > > PVE::Network::SDN::Vnets::add_ip($vnet, $ip, '', $mac, undef); > > + PVE::Network::SDN::Dhcp::update_mapping($vnet, $mac); > + > return undef; > }, > }); > @@ -132,6 +136,9 @@ __PACKAGE__->register_method({ > } > > die "$error\n" if $error; > + > + PVE::Network::SDN::Dhcp::update_mapping($vnet, $mac); > + > return undef; > }, > }); > diff --git a/src/PVE/Network/SDN/Dhcp.pm b/src/PVE/Network/SDN/Dhcp.pm > index 65e40d4..a9459b4 100644 > --- a/src/PVE/Network/SDN/Dhcp.pm > +++ b/src/PVE/Network/SDN/Dhcp.pm > @@ -55,6 +55,27 @@ sub remove_mapping { > $dhcp_plugin->del_ip_mapping($zoneid, $mac); > } > > +# re-apply a MAC's mapping on this node from the current records, best > +# effort, the record write stays authoritative > +sub update_mapping { > + my ($vnetid, $mac) = @_; > + > + eval { > + my $vnet = PVE::Network::SDN::Vnets::get_vnet($vnetid); > + return if !$vnet; > + > + my $zoneid = $vnet->{zone}; > + my $zone = PVE::Network::SDN::Zones::get_zone($zoneid); > + return if !$zone->{ipam} || !$zone->{dhcp}; > + > + my ($ip4, $ip6) = > PVE::Network::SDN::Vnets::get_ips_from_mac($vnetid, $mac); > + my $macdb = PVE::Network::SDN::Ipams::read_macdb(); > + my $dhcp_plugin = > PVE::Network::SDN::Dhcp::Plugin->lookup($zone->{dhcp}); > + $dhcp_plugin->update_ip_mapping($zoneid, $macdb, $mac, $ip4, $ip6); > + }; > + warn "could not update dhcp mapping for $mac: $@" if $@; > +} > + > sub regenerate_config { > my ($reload) = @_; > > diff --git a/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm > b/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm > index 477b700..4677330 100644 > --- a/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm > +++ b/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm > @@ -6,7 +6,7 @@ use warnings; > use base qw(PVE::Network::SDN::Dhcp::Plugin); > > use Net::IP qw(:PROC); > -use PVE::Tools qw(file_set_contents run_command lock_file); > +use PVE::Tools qw(file_get_contents file_set_contents run_command lock_file); > > use File::Copy; > use Net::DBus; > @@ -136,6 +136,36 @@ sub add_ip_mapping { > update_lease($dhcpid, $ip4, $mac); > } > > +sub del_ip_mapping { > + my ($class, $dhcpid, $mac) = @_; > + > + my $ethers_file = ethers_file($dhcpid); > + > + my $reload = undef; > + > + my $removeFn = sub { > + my @lines = split(/\n/, file_get_contents($ethers_file)); > + my @remaining = grep { > + my ($parsed_mac) = split(/,/, $_); > + !defined($parsed_mac) || $parsed_mac ne $mac; > + } @lines; > + > + return if scalar(@remaining) == scalar(@lines); > + > + file_set_contents($ethers_file, join("\n", @remaining) . "\n", 0644); > + $reload = 1; > + }; > + > + PVE::Tools::lock_file($ethers_file, 10, $removeFn); > + > + if ($@) { > + warn "Unable to remove $mac from the dnsmasq configuration: $@\n"; > + return; > + } > + > + systemctl_service('reload', "dnsmasq\@$dhcpid") if $reload; > +} > + > sub configure_subnet { > my ($class, $config, $dhcpid, $vnetid, $subnet_config) = @_; > > diff --git a/src/PVE/Network/SDN/Dhcp/Plugin.pm > b/src/PVE/Network/SDN/Dhcp/Plugin.pm > index b5d32fa..659c938 100644 > --- a/src/PVE/Network/SDN/Dhcp/Plugin.pm > +++ b/src/PVE/Network/SDN/Dhcp/Plugin.pm > @@ -27,6 +27,19 @@ sub add_ip_mapping { > die 'implement in sub class'; > } > > +sub del_ip_mapping { > + my ($class, $dhcpid, $mac) = @_; > + die 'implement in sub class'; > +} > + > +# the MAC's records changed, make the backend serve the current ones > +sub update_ip_mapping { > + my ($class, $dhcpid, $macdb, $mac, $ip4, $ip6) = @_; > + > + $class->del_ip_mapping($dhcpid, $mac); > + $class->add_ip_mapping($dhcpid, $macdb, $mac, $ip4, $ip6) if $ip4 || > $ip6; > +} > + > sub configure_range { > my ($class, $config, $dhcpid, $vnetid, $subnet_config, $range_config) = > @_; > die 'implement in sub class'; > diff --git a/src/PVE/Network/SDN/Vnets.pm b/src/PVE/Network/SDN/Vnets.pm > index c327a4b..daf6654 100644 > --- a/src/PVE/Network/SDN/Vnets.pm > +++ b/src/PVE/Network/SDN/Vnets.pm > @@ -154,6 +154,8 @@ sub add_next_free_cidr { > die "can't find any free ip in zone $zoneid for IPv$ipversion"; > } > } > + > + PVE::Network::SDN::Dhcp::update_mapping($vnetid, $mac) if %$ips; > } > > sub add_ip { > @@ -211,6 +213,8 @@ sub del_ips_from_mac { > PVE::Network::SDN::Vnets::del_ip($vnetid, $ip4, $hostname, $mac) if $ip4; > PVE::Network::SDN::Vnets::del_ip($vnetid, $ip6, $hostname, $mac) if $ip6; > > + PVE::Network::SDN::Dhcp::update_mapping($vnetid, $mac) if $ip4 || $ip6; > + > return ($ip4, $ip6); > } > > @@ -224,12 +228,15 @@ sub add_dhcp_mapping { > > return if !$zone->{ipam} || !$zone->{dhcp}; > > + # an allocation pushes the mapping itself, a guest whose records exist > + # already has to be pushed here > my ($ip4, $ip6) = PVE::Network::SDN::Vnets::get_ips_from_mac($vnetid, > $mac); > - add_next_free_cidr($vnetid, $name, $mac, "$vmid", undef, 1, 4) if !$ip4; > - add_next_free_cidr($vnetid, $name, $mac, "$vmid", undef, 1, 6) if !$ip6; > - > - ($ip4, $ip6) = PVE::Network::SDN::Vnets::get_ips_from_mac($vnetid, $mac); > - PVE::Network::SDN::Dhcp::add_mapping($vnetid, $mac, $ip4, $ip6) if $ip4 > || $ip6; > + if (!$ip4 || !$ip6) { > + add_next_free_cidr($vnetid, $name, $mac, "$vmid", undef, 1, 4) if > !$ip4; > + add_next_free_cidr($vnetid, $name, $mac, "$vmid", undef, 1, 6) if > !$ip6; > + } else { > + PVE::Network::SDN::Dhcp::update_mapping($vnetid, $mac); > + } > } > > 1;
