forked from coredns/coredns
/
zone.go
217 lines (187 loc) · 4.87 KB
/
zone.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
package file
import (
"fmt"
"net"
"path/filepath"
"strings"
"sync"
"time"
"github.com/coredns/coredns/plugin/file/tree"
"github.com/coredns/coredns/plugin/pkg/upstream"
"github.com/coredns/coredns/request"
"github.com/miekg/dns"
)
// Zone defines a structure that contains all data related to a DNS zone.
type Zone struct {
origin string
origLen int
file string
*tree.Tree
Apex Apex
TransferTo []string
StartupOnce sync.Once
TransferFrom []string
Expired *bool
ReloadInterval time.Duration
LastReloaded time.Time
reloadMu sync.RWMutex
reloadShutdown chan bool
Upstream upstream.Upstream // Upstream for looking up 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 {
z := &Zone{
origin: dns.Fqdn(name),
origLen: dns.CountLabel(dns.Fqdn(name)),
file: filepath.Clean(file),
Tree: &tree.Tree{},
Expired: new(bool),
reloadShutdown: make(chan bool),
LastReloaded: time.Now(),
}
*z.Expired = false
return z
}
// Copy copies a zone.
func (z *Zone) Copy() *Zone {
z1 := NewZone(z.origin, z.file)
z1.TransferTo = z.TransferTo
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.TransferTo = z.TransferTo
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
}
// Delete deletes r from z.
func (z *Zone) Delete(r dns.RR) { z.Tree.Delete(r) }
// File retrieves the file path in a safe way
func (z *Zone) File() string {
z.reloadMu.Lock()
defer z.reloadMu.Unlock()
return z.file
}
// SetFile updates the file path in a safe way
func (z *Zone) SetFile(path string) {
z.reloadMu.Lock()
z.file = path
z.reloadMu.Unlock()
}
// TransferAllowed checks if incoming request for transferring the zone is allowed according to the ACLs.
func (z *Zone) TransferAllowed(state request.Request) bool {
for _, t := range z.TransferTo {
if t == "*" {
return true
}
// If remote IP matches we accept.
remote := state.IP()
to, _, err := net.SplitHostPort(t)
if err != nil {
continue
}
if to == remote {
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 {
if z.ReloadInterval > 0 {
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.Apex.SIGNS) > 0 {
records = append(z.Apex.SIGNS, records...)
}
records = append(z.Apex.NS, records...)
if len(z.Apex.SIGSOA) > 0 {
records = append(z.Apex.SIGSOA, records...)
}
return append([]dns.RR{z.Apex.SOA}, records...)
}
// Print prints the zone's tree to stdout.
func (z *Zone) Print() {
z.Tree.Print()
}
// 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
}