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