coredns/middleware/file/zone.go
2016-04-15 20:29:32 +01:00

149 lines
3.2 KiB
Go

package file
import (
"fmt"
"log"
"os"
"path"
"sync"
"github.com/miekg/coredns/middleware"
"github.com/miekg/coredns/middleware/file/tree"
"github.com/fsnotify/fsnotify"
"github.com/miekg/dns"
)
type Zone struct {
SOA *dns.SOA
SIG []dns.RR
origin string
file string
*tree.Tree
TransferTo []string
StartupOnce sync.Once
TransferFrom []string
Expired *bool
NoReload bool
reloadMu sync.RWMutex
// TODO: shutdown watcher channel
}
// NewZone returns a new zone.
func NewZone(name, file string) *Zone {
z := &Zone{origin: dns.Fqdn(name), file: path.Clean(file), Tree: &tree.Tree{}, Expired: new(bool)}
*z.Expired = false
return z
}
// Copy copies a zone *without* copying the zone's content. It is not a deep copy.
func (z *Zone) Copy() *Zone {
z1 := NewZone(z.origin, z.file)
z1.TransferTo = z.TransferTo
z1.TransferFrom = z.TransferFrom
z1.Expired = z.Expired
z1.SOA = z.SOA
z1.SIG = z.SIG
return z1
}
// Insert inserts r into z.
func (z *Zone) Insert(r dns.RR) error {
switch h := r.Header().Rrtype; h {
case dns.TypeSOA:
z.SOA = r.(*dns.SOA)
return nil
case dns.TypeNSEC3, dns.TypeNSEC3PARAM:
return fmt.Errorf("NSEC3 zone is not supported, dropping")
case dns.TypeRRSIG:
if x, ok := r.(*dns.RRSIG); ok && x.TypeCovered == dns.TypeSOA {
z.SIG = append(z.SIG, x)
return nil
}
fallthrough
default:
z.Tree.Insert(r)
}
return nil
}
// Delete deletes r from z.
func (z *Zone) Delete(r dns.RR) { z.Tree.Delete(r) }
// TransferAllowed checks if incoming request for transferring the zone is allowed according to the ACLs.
func (z *Zone) TransferAllowed(state middleware.State) bool {
for _, t := range z.TransferTo {
if t == "*" {
return true
}
}
// TODO(miek): future matching against IP/CIDR notations
return false
}
// All returns all records from the zone, the first record will be the SOA record,
// otionally followed by all RRSIG(SOA)s.
func (z *Zone) All() []dns.RR {
z.reloadMu.RLock()
defer z.reloadMu.RUnlock()
records := []dns.RR{}
allNodes := z.Tree.All()
for _, a := range allNodes {
records = append(records, a.All()...)
}
if len(z.SIG) > 0 {
records = append(z.SIG, records...)
}
return append([]dns.RR{z.SOA}, records...)
}
func (z *Zone) Reload(shutdown chan bool) error {
if z.NoReload {
return nil
}
watcher, err := fsnotify.NewWatcher()
if err != nil {
return err
}
err = watcher.Add(path.Dir(z.file))
if err != nil {
return err
}
go func() {
// TODO(miek): needs to be killed on reload.
for {
select {
case event := <-watcher.Events:
if path.Clean(event.Name) == z.file {
reader, err := os.Open(z.file)
if err != nil {
log.Printf("[ERROR] Failed to open `%s' for `%s': %v", z.file, z.origin, err)
continue
}
z.reloadMu.Lock()
zone, err := Parse(reader, z.origin, z.file)
if err != nil {
log.Printf("[ERROR] Failed to parse `%s': %v", z.origin, err)
z.reloadMu.Unlock()
continue
}
// copy elements we need
z.SOA = zone.SOA
z.SIG = zone.SIG
z.Tree = zone.Tree
z.reloadMu.Unlock()
log.Printf("[INFO] Successfully reloaded zone `%s'", z.origin)
z.Notify()
}
case <-shutdown:
watcher.Close()
return
}
}
}()
return nil
}