Files
netbird/shared/management/networkmap/peers_custom_zone.go
2026-08-03 17:27:24 +02:00

112 lines
3.2 KiB
Go

package networkmap
import (
"context"
"fmt"
"strings"
"github.com/hashicorp/go-multierror"
"github.com/miekg/dns"
log "github.com/sirupsen/logrus"
nbdns "github.com/netbirdio/netbird/dns"
"github.com/netbirdio/netbird/shared/management/networkmap/nmdata"
)
const peersZoneRecordTTL = 300
// PeersCustomZone builds the peers DNS zone from twin peer rows. It is the
// single source of the zone-record logic; Account.GetPeersCustomZone delegates
// here via twins.
func PeersCustomZone(ctx context.Context, accountID string, dnsDomain string, peers map[string]*nmdata.Peer, ipv6AllowedPeers map[string]struct{}) nmdata.CustomZone {
var merr *multierror.Error
if dnsDomain == "" {
log.WithContext(ctx).Error("no dns domain is set, returning empty zone")
return nmdata.CustomZone{}
}
customZone := nmdata.CustomZone{
Domain: dns.Fqdn(dnsDomain),
Records: make([]nmdata.SimpleRecord, 0, len(peers)),
}
domainSuffix := "." + dnsDomain
var sb strings.Builder
for _, peer := range peers {
if peer == nil {
continue
}
if peer.DNSLabel == "" {
merr = multierror.Append(merr, fmt.Errorf("peer %s has an empty DNS label", peer.ID))
continue
}
sb.Grow(len(peer.DNSLabel) + len(domainSuffix))
sb.WriteString(peer.DNSLabel)
sb.WriteString(domainSuffix)
fqdn := sb.String()
customZone.Records = append(customZone.Records, nmdata.SimpleRecord{
Name: fqdn,
Type: int(dns.TypeA),
Class: nbdns.DefaultClass,
TTL: peersZoneRecordTTL,
RData: peer.IP.String(),
})
// Only advertise AAAA for peers that have a valid IPv6, whose client supports it,
// and that belong to an IPv6-enabled group. Old clients don't configure v6 on their
// WireGuard interface, so resolving their AAAA causes connections to hang.
// Capability changes (client upgrade/downgrade, --disable-ipv6 toggle) propagate
// to other peers via SyncPeer/LoginPeer regardless of version change, so AAAA
// records refresh when a peer first reports the IPv6 overlay capability.
_, peerAllowed := ipv6AllowedPeers[peer.ID]
hasIPv6 := peer.IPv6.IsValid() && peer.SupportsIPv6() && peerAllowed
if hasIPv6 {
customZone.Records = append(customZone.Records, nmdata.SimpleRecord{
Name: fqdn,
Type: int(dns.TypeAAAA),
Class: nbdns.DefaultClass,
TTL: peersZoneRecordTTL,
RData: peer.IPv6.String(),
})
}
sb.Reset()
for _, extraLabel := range peer.ExtraDNSLabels {
sb.Grow(len(extraLabel) + len(domainSuffix))
sb.WriteString(extraLabel)
sb.WriteString(domainSuffix)
extraFqdn := sb.String()
customZone.Records = append(customZone.Records, nmdata.SimpleRecord{
Name: extraFqdn,
Type: int(dns.TypeA),
Class: nbdns.DefaultClass,
TTL: peersZoneRecordTTL,
RData: peer.IP.String(),
})
if hasIPv6 {
customZone.Records = append(customZone.Records, nmdata.SimpleRecord{
Name: extraFqdn,
Type: int(dns.TypeAAAA),
Class: nbdns.DefaultClass,
TTL: peersZoneRecordTTL,
RData: peer.IPv6.String(),
})
}
sb.Reset()
}
}
go func() {
if merr != nil {
log.WithContext(ctx).Errorf("error generating custom zone for account %s: %v", accountID, merr)
}
}()
return customZone
}