mirror of
https://github.com/netbirdio/netbird.git
synced 2024-11-28 11:03:30 +01:00
111 lines
2.9 KiB
Go
111 lines
2.9 KiB
Go
// Package dns implement dns types and standard methods and functions
|
|
// to parse and normalize dns records and configuration
|
|
package dns
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"regexp"
|
|
"strings"
|
|
|
|
"github.com/miekg/dns"
|
|
"golang.org/x/net/idna"
|
|
)
|
|
|
|
const (
|
|
// DefaultDNSPort well-known port number
|
|
DefaultDNSPort = 53
|
|
// RootZone is a string representation of the root zone
|
|
RootZone = "."
|
|
// DefaultClass is the class supported by the system
|
|
DefaultClass = "IN"
|
|
)
|
|
|
|
const invalidHostLabel = "[^a-zA-Z0-9-]+"
|
|
|
|
// Config represents a dns configuration that is exchanged between management and peers
|
|
type Config struct {
|
|
// ServiceEnable indicates if the service should be enabled
|
|
ServiceEnable bool
|
|
// NameServerGroups contains a list of nameserver group
|
|
NameServerGroups []*NameServerGroup
|
|
// CustomZones contains a list of custom zone
|
|
CustomZones []CustomZone
|
|
}
|
|
|
|
// CustomZone represents a custom zone to be resolved by the dns server
|
|
type CustomZone struct {
|
|
// Domain is the zone's domain
|
|
Domain string
|
|
// Records custom zone records
|
|
Records []SimpleRecord
|
|
}
|
|
|
|
// SimpleRecord provides a simple DNS record specification for CNAME, A and AAAA records
|
|
type SimpleRecord struct {
|
|
// Name domain name
|
|
Name string
|
|
// Type of record, 1 for A, 5 for CNAME, 28 for AAAA. see https://pkg.go.dev/github.com/miekg/dns@v1.1.41#pkg-constants
|
|
Type int
|
|
// Class dns class, currently use the DefaultClass for all records
|
|
Class string
|
|
// TTL time-to-live for the record
|
|
TTL int
|
|
// RData is the actual value resolved in a dns query
|
|
RData string
|
|
}
|
|
|
|
// String returns a string of the simple record formatted as:
|
|
// <Name> <TTL> <Class> <Type> <RDATA>
|
|
func (s SimpleRecord) String() string {
|
|
fqdn := dns.Fqdn(s.Name)
|
|
return fmt.Sprintf("%s %d %s %s %s", fqdn, s.TTL, s.Class, dns.Type(s.Type).String(), s.RData)
|
|
}
|
|
|
|
// Len returns the length of the RData field, based on its type
|
|
func (s SimpleRecord) Len() uint16 {
|
|
emptyString := s.RData == ""
|
|
switch s.Type {
|
|
case 1:
|
|
if emptyString {
|
|
return 0
|
|
}
|
|
return net.IPv4len
|
|
case 5:
|
|
if emptyString || s.RData == "." {
|
|
return 1
|
|
}
|
|
return uint16(len(s.RData) + 1)
|
|
case 28:
|
|
if emptyString {
|
|
return 0
|
|
}
|
|
return net.IPv6len
|
|
default:
|
|
return 0
|
|
}
|
|
}
|
|
|
|
var invalidHostMatcher = regexp.MustCompile(invalidHostLabel)
|
|
|
|
// GetParsedDomainLabel returns a domain label with max 59 characters,
|
|
// parsed for old Hosts.txt requirements, and converted to ASCII and lowercase
|
|
func GetParsedDomainLabel(name string) (string, error) {
|
|
labels := dns.SplitDomainName(name)
|
|
if len(labels) == 0 {
|
|
return "", fmt.Errorf("got empty label list for name \"%s\"", name)
|
|
}
|
|
rawLabel := labels[0]
|
|
ascii, err := idna.Punycode.ToASCII(rawLabel)
|
|
if err != nil {
|
|
return "", fmt.Errorf("unable to convert host label to ASCII, error: %v", err)
|
|
}
|
|
|
|
validHost := strings.ToLower(invalidHostMatcher.ReplaceAllString(ascii, "-"))
|
|
if len(validHost) > 58 {
|
|
validHost = validHost[:59]
|
|
}
|
|
|
|
return validHost, nil
|
|
}
|