From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate001.proxmox.com (gate001.proxmox.com [45.144.208.40]) by lore.proxmox.com (Postfix) with ESMTPS id 537671FF0AA for ; Tue, 20 Oct 2026 15:09:56 +0200 (CEST) Received: from gate001.proxmox.com (localhost.localdomain [127.0.0.1]) by gate001.proxmox.com (Proxmox) with ESMTP id EB2F9216B5; Tue, 20 Oct 2026 15:09:52 +0200 (CEST) Message-ID: Date: Tue, 20 Oct 2026 15:09:45 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Stefan Hanreich Subject: Re: [PATCH pve-network v3 11/17] sdn: dhcp: push IP mapping edits to the guest's node To: pve-devel@lists.proxmox.com References: <20261020080005.470757-1-h.laimer@proxmox.com> <20261020080005.470757-12-h.laimer@proxmox.com> Content-Language: en-US In-Reply-To: <20261020080005.470757-12-h.laimer@proxmox.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.257 Adjusted score from AWL reputation of From: address DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment (newer systems) POISEN_SPAM_PILL 0.1 Meta: its spam POISEN_SPAM_PILL_1 0.1 random spam to be learned in bayes POISEN_SPAM_PILL_3 0.1 random spam to be learned in bayes RCVD_IN_DNSWL_MED -2.3 Sender listed at https://www.dnswl.org/, medium trust SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: 3HEWSA2UKL2OZOJ6DPI7LZGNX7NAKSUV X-Message-ID-Hash: 3HEWSA2UKL2OZOJ6DPI7LZGNX7NAKSUV X-MailFrom: s.hanreich@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On 10/20/26 10:02 AM, Hannes Laimer wrote: > IP mappings live in the cluster-wide IPAM and can be edited through > the API on any node. The DHCP backends hold their copy on each node, > dnsmasq in a reservation file and the ebpf responder in a kernel map. > An edit only updated the backend of the node it was made on, so a > guest on another node kept getting the old mapping. > > The new endpoint POST /nodes/{node}/sdn/dhcp-mapping updates the > mapping of one MAC on that node from the current records. An edit > made on a node other than the guest's calls it on the guest's node. > Only that node answers the guest's DHCP requests, so no other node is > called. The others catch up when the guest starts on one of them. > > The call runs in the background, so the request returns without > waiting on the other node. A call that fails logs its error to the > journal of the node the edit was made on. One that gets no answer is > stopped after a minute. The record stays as written either way, and > the guest's node picks it up at the latest when the guest next starts > there. > > Signed-off-by: Hannes Laimer > --- > src/PVE/API2/Network/SDN/Ips.pm | 3 + > src/PVE/API2/Network/SDN/Nodes/Status.pm | 37 ++++++++++ > src/PVE/Network/SDN/Dhcp.pm | 74 +++++++++++++++++++ > src/test/run_test_vnets_blackbox.pl | 90 ++++++++++++++++++++++++ > 4 files changed, 204 insertions(+) > > diff --git a/src/PVE/API2/Network/SDN/Ips.pm b/src/PVE/API2/Network/SDN/Ips.pm > index d7b682dd..5b45de7c 100644 > --- a/src/PVE/API2/Network/SDN/Ips.pm > +++ b/src/PVE/API2/Network/SDN/Ips.pm > @@ -47,6 +47,7 @@ __PACKAGE__->register_method({ > die "$@\n" if $@; > > PVE::Network::SDN::Dhcp::update_mapping($vnet, $mac); > + PVE::Network::SDN::Dhcp::notify_guest_node($vnet, $mac); > > return undef; > }, > @@ -85,6 +86,7 @@ __PACKAGE__->register_method({ > PVE::Network::SDN::Vnets::add_ip($vnet, $ip, '', $mac, undef); > > PVE::Network::SDN::Dhcp::update_mapping($vnet, $mac); > + PVE::Network::SDN::Dhcp::notify_guest_node($vnet, $mac); > > return undef; > }, > @@ -138,6 +140,7 @@ __PACKAGE__->register_method({ > die "$error\n" if $error; > > PVE::Network::SDN::Dhcp::update_mapping($vnet, $mac); > + PVE::Network::SDN::Dhcp::notify_guest_node($vnet, $mac); > > return undef; > }, > diff --git a/src/PVE/API2/Network/SDN/Nodes/Status.pm b/src/PVE/API2/Network/SDN/Nodes/Status.pm > index 7977e0c8..fe750a85 100644 > --- a/src/PVE/API2/Network/SDN/Nodes/Status.pm > +++ b/src/PVE/API2/Network/SDN/Nodes/Status.pm > @@ -9,6 +9,9 @@ use PVE::API2::Network::SDN::Nodes::Vnets; > > use PVE::JSONSchema qw(get_standard_option); > > +use PVE::Network::SDN::Vnets; > +use PVE::Network::SDN::Dhcp; > + > use PVE::RESTHandler; > use base qw(PVE::RESTHandler); > > @@ -27,6 +30,40 @@ __PACKAGE__->register_method({ > path => 'vnets', > }); > > +__PACKAGE__->register_method({ > + name => 'dhcp_mapping', > + path => 'dhcp-mapping', > + method => 'POST', > + description => > + 'Re-apply the DHCP mapping of a MAC address on this node from the current records.', > + permissions => { > + check => ['perm', '/sdn/zones/{zone}/{vnet}', ['SDN.Allocate']], > + }, > + protected => 1, > + proxyto => 'node', > + parameters => { > + additionalProperties => 0, > + properties => { > + node => get_standard_option('pve-node'), > + zone => get_standard_option('pve-sdn-zone-id'), > + vnet => get_standard_option('pve-sdn-vnet-id'), > + mac => get_standard_option('mac-addr'), > + }, > + }, > + returns => { type => 'null' }, > + code => sub { > + my ($param) = @_; > + > + my $vnet = PVE::Network::SDN::Vnets::get_vnet($param->{vnet}, 1); > + die "vnet '$param->{vnet}' does not exist in zone '$param->{zone}'\n" > + if !$vnet || $vnet->{zone} ne $param->{zone}; > + > + PVE::Network::SDN::Dhcp::update_mapping($param->{vnet}, $param->{mac}); > + > + return undef; > + }, > +}); > + > __PACKAGE__->register_method({ > name => 'sdnindex', > path => '', > diff --git a/src/PVE/Network/SDN/Dhcp.pm b/src/PVE/Network/SDN/Dhcp.pm > index cf805a03..1f43745f 100644 > --- a/src/PVE/Network/SDN/Dhcp.pm > +++ b/src/PVE/Network/SDN/Dhcp.pm > @@ -3,6 +3,8 @@ package PVE::Network::SDN::Dhcp; > use strict; > use warnings; > > +use POSIX qw(); > + > use PVE::Cluster; > > use PVE::Network::SDN; > @@ -86,6 +88,78 @@ sub guest_nics { > return $nics; > } > > +sub guest_node_by_mac { > + my ($vnetid, $mac) = @_; > + > + for my $nic (guest_nics()->@*) { > + return $nic->{node} > + if lc($nic->{mac} // '') eq lc($mac) && $nic->{bridge} eq $vnetid; > + } > + > + return undef; > +} seems like we're always (or at least most of the time) querying by MAC so would assembling a hash keyed by MAC addresses in the first place be sensible? > +sub notify_guest_node { > + my ($vnetid, $mac) = @_; > + > + return if !$mac; > + > + # best effort like the push itself, since the record is written by now > + my ($zoneid, $node) = eval { > + my $vnet = PVE::Network::SDN::Vnets::get_vnet($vnetid, 1); > + return if !$vnet; > + > + my $zone = PVE::Network::SDN::Zones::get_zone($vnet->{zone}, 1); > + return if !$zone || !$zone->{ipam} || !$zone->{dhcp}; > + > + return ($vnet->{zone}, guest_node_by_mac($vnetid, $mac)); > + }; > + if ($@) { > + warn "could not find the node to push the dhcp mapping of $mac to: $@"; > + return; > + } > + return if !$node || $node eq PVE::INotify::nodename(); > + > + # double fork, the grandchild is reparented to init so nothing on > + # the request path ever waits on it > + my $pid = fork(); > + if (!defined($pid)) { > + warn "could not fork for the dhcp mapping push to $node: $!\n"; > + return; > + } > + if ($pid) { > + waitpid($pid, 0); > + return; > + } > + > + POSIX::setsid(); > + my $child = fork(); > + POSIX::_exit(1) if !defined($child); > + POSIX::_exit(0) if $child; > + > + # nothing of the request stays with the push, and since the daemon's > + # stderr is closed a failed push reports through the journal > + open(STDIN, '<', '/dev/null') or POSIX::_exit(1); > + open(STDOUT, '>', '/dev/null') or POSIX::_exit(1); > + open(STDERR, '|-', 'logger', '-t', 'pve-sdn', '-p', 'daemon.warning') > + or POSIX::_exit(1); > + # a node that takes the connection but never answers must not keep the > + # push around > + exec( > + 'timeout', > + '60', > + 'pvesh', > + 'create', > + "/nodes/$node/sdn/dhcp-mapping", > + '--zone', > + $zoneid, > + '--vnet', > + $vnetid, > + '--mac', > + $mac, > + ) or POSIX::_exit(1); > +} > + There've been efforts of moving away from pvesh - see my other patch series introducing the api client instead of calling pvesh here: https://lore.proxmox.com/all/20260709140625.275618-1-s.hanreich@proxmox.com/ Might be the better option here as well? Also, there is proxyto_callback which we could use to proxy to the correct node in the first place? > sub tap_plug { > my ($bridge, $iface, $mac) = @_; > > diff --git a/src/test/run_test_vnets_blackbox.pl b/src/test/run_test_vnets_blackbox.pl > index 783d0d47..9a4dbb9c 100755 > --- a/src/test/run_test_vnets_blackbox.pl > +++ b/src/test/run_test_vnets_blackbox.pl > @@ -49,6 +49,7 @@ sub clear_test_state { > dnsmasq_calls => [], > ebpf_calls => [], > order => [], > + notify_calls => [], > warnings => [], > ipam_config => { > 'ids' => { > @@ -238,6 +239,11 @@ $mocked_sdn_dhcp_dnsmasq->mock( > update_lease => sub { }, > ); > > +my $mocked_sdn_dhcp = Test::MockModule->new('PVE::Network::SDN::Dhcp'); > +$mocked_sdn_dhcp->mock( > + notify_guest_node => sub { push $test_state->{notify_calls}->@*, [@_]; }, > +); > + > my $mocked_pve_rs_dhcp = Test::MockModule->new('PVE::RS::SDN::Dhcp'); > $mocked_pve_rs_dhcp->mock( > detach => sub { > @@ -1280,6 +1286,90 @@ sub test_dhcp_backend_needed_per_node { > > run_test(\&test_dhcp_backend_needed_per_node); > > +sub test_mapping_push_target { > + my $test_name = (split(/::/, (caller(0))[3]))[-1]; > + my $zoneid = "TESTZONE"; > + my $vnetid = "testvnet"; > + my $mac = "da:65:8f:18:9b:6f"; > + > + create_zone({ > + type => "simple", > + dhcp => "dnsmasq", > + ipam => "pve", > + zone => $zoneid, > + }); > + create_vnet({ > + type => "vnet", > + zone => $zoneid, > + vnet => $vnetid, > + }); > + create_subnet({ > + type => "subnet", > + vnet => $vnetid, > + subnet => "10.0.0.0/24", > + gateway => "10.0.0.1", > + }); > + > + # the guest behind a MAC is found by its NIC on the vnet, and the config > + # writes the MAC in upper case > + $test_state->{vmlist} = { > + ids => { > + 100 => { type => 'qemu', node => 'other' }, > + 101 => { type => 'lxc', node => 'third' }, > + }, > + }; > + $test_state->{guest_nets} = { > + 1 => { net0 => "virtio=$mac,bridge=$vnetid" }, > + 100 => { net0 => "virtio=" . uc($mac) . ",bridge=$vnetid" }, > + 101 => { net0 => "name=eth0,bridge=vmbr0,hwaddr=00:11:22:33:44:55" }, > + }; > + is( > + PVE::Network::SDN::Dhcp::guest_node_by_mac($vnetid, $mac), > + 'other', > + "$test_name: the MAC resolves to the node of its guest, a guest the list lacks is skipped", > + ); > + is( > + PVE::Network::SDN::Dhcp::guest_node_by_mac($vnetid, '00:11:22:33:44:55'), > + undef, > + "$test_name: a MAC on another bridge does not resolve", > + ); > + is( > + PVE::Network::SDN::Dhcp::guest_node_by_mac($vnetid, '00:11:22:33:44:66'), > + undef, > + "$test_name: an unknown MAC does not resolve", > + ); > + > + # every mapping edit through the API pokes the guest's node once > + $test_state->{notify_calls} = []; > + create_ip({ > + zone => $zoneid, > + vnet => $vnetid, > + mac => $mac, > + ip => "10.0.0.50", > + }); > + update_ip({ > + zone => $zoneid, > + vnet => $vnetid, > + mac => $mac, > + ip => "10.0.0.51", > + }); > + delete_ip({ > + zone => $zoneid, > + vnet => $vnetid, > + mac => $mac, > + ip => "10.0.0.51", > + }); > + eq_or_diff( > + $test_state->{notify_calls}, > + [[$vnetid, $mac], [$vnetid, $mac], [$vnetid, $mac]], > + "$test_name: create, edit and delete each poke the guest's node", > + ); > + delete $test_state->{vmlist}; > + delete $test_state->{guest_nets}; > +} > + > +run_test(\&test_mapping_push_target); > + > sub test_ipam_cache_misses { > my $test_name = (split(/::/, (caller(0))[3]))[-1]; > my $zoneid = "TESTZONE";