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package file
import (
"fmt"
"path/filepath"
"strings"
"sync"
"time"
"github.com/coredns/coredns/plugin/file/tree"
"github.com/coredns/coredns/plugin/pkg/upstream"
"github.com/miekg/dns"
)
// Zone is a structure that contains all data related to a DNS zone.
type Zone struct {
origin string
origLen int
file string
*tree.Tree
Apex
Expired bool
sync.RWMutex
StartupOnce sync.Once
TransferFrom []string
ReloadInterval time.Duration
reloadShutdown chan bool
Upstream *upstream.Upstream // Upstream for looking up external names during the resolution process.
}
// Apex contains the apex records of a zone: SOA, NS and their potential signatures.
type Apex struct {
SOA *dns.SOA
NS []dns.RR
SIGSOA []dns.RR
SIGNS []dns.RR
}
// NewZone returns a new zone.
func NewZone(name, file string) *Zone {
return &Zone{
origin: dns.Fqdn(name),
origLen: dns.CountLabel(dns.Fqdn(name)),
file: filepath.Clean(file),
Tree: &tree.Tree{},
reloadShutdown: make(chan bool),
}
}
// Copy copies a zone.
func (z *Zone) Copy() *Zone {
z1 := NewZone(z.origin, z.file)
z1.TransferFrom = z.TransferFrom
z1.Expired = z.Expired
z1.Apex = z.Apex
return z1
}
// CopyWithoutApex copies zone z without the Apex records.
func (z *Zone) CopyWithoutApex() *Zone {
z1 := NewZone(z.origin, z.file)
z1.TransferFrom = z.TransferFrom
z1.Expired = z.Expired
return z1
}
// Insert inserts r into z.
func (z *Zone) Insert(r dns.RR) error {
r.Header().Name = strings.ToLower(r.Header().Name)
switch h := r.Header().Rrtype; h {
case dns.TypeNS:
r.(*dns.NS).Ns = strings.ToLower(r.(*dns.NS).Ns)
if r.Header().Name == z.origin {
z.Apex.NS = append(z.Apex.NS, r)
return nil
}
case dns.TypeSOA:
r.(*dns.SOA).Ns = strings.ToLower(r.(*dns.SOA).Ns)
r.(*dns.SOA).Mbox = strings.ToLower(r.(*dns.SOA).Mbox)
z.Apex.SOA = r.(*dns.SOA)
return nil
case dns.TypeNSEC3, dns.TypeNSEC3PARAM:
return fmt.Errorf("NSEC3 zone is not supported, dropping RR: %s for zone: %s", r.Header().Name, z.origin)
case dns.TypeRRSIG:
x := r.(*dns.RRSIG)
switch x.TypeCovered {
case dns.TypeSOA:
z.Apex.SIGSOA = append(z.Apex.SIGSOA, x)
return nil
case dns.TypeNS:
if r.Header().Name == z.origin {
z.Apex.SIGNS = append(z.Apex.SIGNS, x)
return nil
}
}
case dns.TypeCNAME:
r.(*dns.CNAME).Target = strings.ToLower(r.(*dns.CNAME).Target)
case dns.TypeMX:
r.(*dns.MX).Mx = strings.ToLower(r.(*dns.MX).Mx)
case dns.TypeSRV:
r.(*dns.SRV).Target = strings.ToLower(r.(*dns.SRV).Target)
}
z.Tree.Insert(r)
return nil
}
// File retrieves the file path in a safe way.
func (z *Zone) File() string {
z.RLock()
defer z.RUnlock()
return z.file
}
// SetFile updates the file path in a safe way.
func (z *Zone) SetFile(path string) {
z.Lock()
z.file = path
z.Unlock()
}
// ApexIfDefined returns the apex nodes from z. The SOA record is the first record, if it does not exist, an error is returned.
func (z *Zone) ApexIfDefined() ([]dns.RR, error) {
z.RLock()
defer z.RUnlock()
if z.Apex.SOA == nil {
return nil, fmt.Errorf("no SOA")
}
rrs := []dns.RR{z.Apex.SOA}
if len(z.Apex.SIGSOA) > 0 {
rrs = append(rrs, z.Apex.SIGSOA...)
}
if len(z.Apex.NS) > 0 {
rrs = append(rrs, z.Apex.NS...)
}
if len(z.Apex.SIGNS) > 0 {
rrs = append(rrs, z.Apex.SIGNS...)
}
return rrs, nil
}
// NameFromRight returns the labels from the right, staring with the
// origin and then i labels extra. When we are overshooting the name
// the returned boolean is set to true.
func (z *Zone) nameFromRight(qname string, i int) (string, bool) {
if i <= 0 {
return z.origin, false
}
for j := 1; j <= z.origLen; j++ {
if _, shot := dns.PrevLabel(qname, j); shot {
return qname, shot
}
}
k := 0
var shot bool
for j := 1; j <= i; j++ {
k, shot = dns.PrevLabel(qname, j+z.origLen)
if shot {
return qname, shot
}
}
return qname[k:], false
}
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