73 lines
2.3 KiB
Go
73 lines
2.3 KiB
Go
package dnsserver
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"strings"
|
|
)
|
|
|
|
type zoneAddr struct {
|
|
Zone string
|
|
Port string
|
|
Transport string // dns, tls or grpc
|
|
Address string // used for bound zoneAddr - validation of overlapping
|
|
}
|
|
|
|
// String returns the string representation of z.
|
|
func (z zoneAddr) String() string {
|
|
s := z.Transport + "://" + z.Zone + ":" + z.Port
|
|
if z.Address != "" {
|
|
s += " on " + z.Address
|
|
}
|
|
return s
|
|
}
|
|
|
|
// SplitProtocolHostPort splits a full formed address like "dns://[::1]:53" into parts.
|
|
func SplitProtocolHostPort(address string) (protocol string, ip string, port string, err error) {
|
|
parts := strings.Split(address, "://")
|
|
switch len(parts) {
|
|
case 1:
|
|
ip, port, err := net.SplitHostPort(parts[0])
|
|
return "", ip, port, err
|
|
case 2:
|
|
ip, port, err := net.SplitHostPort(parts[1])
|
|
return parts[0], ip, port, err
|
|
default:
|
|
return "", "", "", fmt.Errorf("provided value is not in an address format : %s", address)
|
|
}
|
|
}
|
|
|
|
type zoneOverlap struct {
|
|
registeredAddr map[zoneAddr]zoneAddr // each zoneAddr is registered once by its key
|
|
unboundOverlap map[zoneAddr]zoneAddr // the "no bind" equiv ZoneAddr is registered by its original key
|
|
}
|
|
|
|
func newOverlapZone() *zoneOverlap {
|
|
return &zoneOverlap{registeredAddr: make(map[zoneAddr]zoneAddr), unboundOverlap: make(map[zoneAddr]zoneAddr)}
|
|
}
|
|
|
|
// registerAndCheck adds a new zoneAddr for validation, it returns information about existing or overlapping with already registered
|
|
// we consider that an unbound address is overlapping all bound addresses for same zone, same port
|
|
func (zo *zoneOverlap) registerAndCheck(z zoneAddr) (existingZone *zoneAddr, overlappingZone *zoneAddr) {
|
|
|
|
if exist, ok := zo.registeredAddr[z]; ok {
|
|
// exact same zone already registered
|
|
return &exist, nil
|
|
}
|
|
uz := zoneAddr{Zone: z.Zone, Address: "", Port: z.Port, Transport: z.Transport}
|
|
if already, ok := zo.unboundOverlap[uz]; ok {
|
|
if z.Address == "" {
|
|
// current is not bound to an address, but there is already another zone with a bind address registered
|
|
return nil, &already
|
|
}
|
|
if _, ok := zo.registeredAddr[uz]; ok {
|
|
// current zone is bound to an address, but there is already an overlapping zone+port with no bind address
|
|
return nil, &uz
|
|
}
|
|
}
|
|
// there is no overlap, keep the current zoneAddr for future checks
|
|
zo.registeredAddr[z] = z
|
|
zo.unboundOverlap[uz] = z
|
|
return nil, nil
|
|
}
|