82 lines
1.9 KiB
Go
82 lines
1.9 KiB
Go
package nameresolver
|
|
|
|
import (
|
|
"github.com/miekg/dns"
|
|
"net"
|
|
"strings"
|
|
"encoding/json"
|
|
)
|
|
|
|
// serializedEntry is used as a proxy to generate a JSON representation of an entry, using the json go module.
|
|
type serializedEntry struct {
|
|
Name string `json:"name"`
|
|
Alias *string `json:"alias,omitempty"`
|
|
Addrs *[]net.IP `json:"addrs,omitempty"`
|
|
}
|
|
|
|
// Entry represents the resolution of a name, either into an alias (CNAME) or a list of IP addresses (both v4 and v6).
|
|
type Entry struct {
|
|
owner string
|
|
cNAMETarget string
|
|
addrs []net.IP
|
|
}
|
|
|
|
// NewAliasEntry is the constructor of an entry whose content symbolizes a domain name owning just a CNAME.
|
|
func NewAliasEntry(owner, CNAMETarget string) *Entry {
|
|
e := new(Entry)
|
|
e.owner = strings.ToLower(dns.Fqdn(owner))
|
|
e.cNAMETarget = strings.ToLower(dns.Fqdn(CNAMETarget))
|
|
return e
|
|
}
|
|
|
|
// NewIPEntry is the constructor of an entry whose content is a domain name and its associated IP addresses.
|
|
func NewIPEntry(name string, addrs []net.IP) *Entry {
|
|
e := new(Entry)
|
|
e.owner = strings.ToLower(dns.Fqdn(name))
|
|
e.cNAMETarget = ""
|
|
e.addrs = addrs
|
|
return e
|
|
}
|
|
|
|
// Implements json.Marshaler
|
|
func (e *Entry) MarshalJSON() ([]byte, error) {
|
|
sre := new(serializedEntry)
|
|
sre.Name = e.owner
|
|
if e.cNAMETarget != "" {
|
|
sre.Alias = new(string)
|
|
*sre.Alias = e.cNAMETarget
|
|
} else if len(e.addrs) > 0 {
|
|
sre.Addrs = new([]net.IP)
|
|
*sre.Addrs = e.addrs
|
|
}
|
|
return json.Marshal(sre)
|
|
}
|
|
|
|
// Implements json.Unmarshaler
|
|
func (e *Entry) UnmarshalJSON(bstr []byte) error {
|
|
sre := new(serializedEntry)
|
|
err := json.Unmarshal(bstr, sre)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
e.owner = sre.Name
|
|
if sre.Alias != nil {
|
|
e.cNAMETarget = *sre.Alias
|
|
}
|
|
if sre.Addrs != nil {
|
|
e.addrs = *sre.Addrs
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (e *Entry) Owner() string {
|
|
return e.owner
|
|
}
|
|
|
|
func (e *Entry) CNAMETarget() string {
|
|
return e.cNAMETarget
|
|
}
|
|
|
|
func (e *Entry) Addrs() []net.IP {
|
|
return e.addrs
|
|
}
|