Files
Archive/brook/dohclient.go
T
2024-03-05 02:32:38 -08:00

116 lines
2.4 KiB
Go

// Copyright (c) 2016-present Cloud <cloud@txthinking.com>
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of version 3 of the GNU General Public
// License as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
package brook
import (
"bytes"
"errors"
"io"
"net"
"net/http"
"net/url"
"github.com/miekg/dns"
)
type DOHClient struct {
Client *http.Client
DOH string
}
func NewDOHClient(doh string) (*DOHClient, error) {
u, err := url.Parse(doh)
if err != nil {
return nil, err
}
a := u.Query().Get("address")
if a == "" {
return nil, errors.New("no address")
}
q := u.Query()
q.Del("address")
u.RawQuery = q.Encode()
c := &http.Client{
Transport: &http.Transport{
Dial: func(network, addr string) (net.Conn, error) {
return DialTCP("tcp", "", a)
},
},
}
return &DOHClient{
Client: c,
DOH: u.String(),
}, nil
}
func (c *DOHClient) Exchange(m *dns.Msg) (*dns.Msg, error) {
b, err := m.Pack()
if err != nil {
return nil, err
}
hr, err := http.NewRequest("POST", c.DOH, bytes.NewReader(b))
if err != nil {
return nil, err
}
hr.Header.Set("Accept", "application/dns-message")
hr.Header.Set("Content-Type", "application/dns-message")
res, err := c.Client.Do(hr)
if err != nil {
return nil, err
}
defer res.Body.Close()
b, err = io.ReadAll(res.Body)
if err != nil {
return nil, err
}
r := &dns.Msg{}
if err := r.Unpack(b); err != nil {
return nil, err
}
return r, nil
}
// if no AAAA, return nil
func (c *DOHClient) AAAA(domain string) (net.IP, error) {
m := &dns.Msg{}
m.SetQuestion(domain+".", dns.TypeAAAA)
m, err := c.Exchange(m)
if err != nil {
return nil, err
}
for _, v := range m.Answer {
if t, ok := v.(*dns.AAAA); ok {
return t.AAAA, nil
}
}
return nil, nil
}
// if no A, return nil
func (c *DOHClient) A(domain string) (net.IP, error) {
m := &dns.Msg{}
m.SetQuestion(domain+".", dns.TypeA)
m, err := c.Exchange(m)
if err != nil {
return nil, err
}
for _, v := range m.Answer {
if t, ok := v.(*dns.A); ok {
return t.A, nil
}
}
return nil, nil
}