146 lines
2.9 KiB
Go
146 lines
2.9 KiB
Go
package main
|
|
|
|
import (
|
|
"context"
|
|
"crypto/tls"
|
|
"net"
|
|
"sync"
|
|
|
|
"github.com/fumiama/terasu"
|
|
)
|
|
|
|
type dnsstat struct {
|
|
A string
|
|
E bool
|
|
}
|
|
|
|
type dnsservers struct {
|
|
sync.RWMutex
|
|
m map[string][]*dnsstat
|
|
}
|
|
|
|
// hasrecord no lock, use under lock
|
|
func hasrecord(lst []*dnsstat, a string) bool {
|
|
for _, addr := range lst {
|
|
if addr.A == a {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (ds *dnsservers) add(m map[string][]string) {
|
|
ds.Lock()
|
|
defer ds.Unlock()
|
|
addList := map[string][]*dnsstat{}
|
|
for host, addrs := range m {
|
|
for _, addr := range addrs {
|
|
if !hasrecord(ds.m[host], addr) && !hasrecord(addList[host], addr) {
|
|
addList[host] = append(addList[host], &dnsstat{addr, true})
|
|
}
|
|
}
|
|
}
|
|
for host, addrs := range addList {
|
|
ds.m[host] = append(ds.m[host], addrs...)
|
|
}
|
|
}
|
|
|
|
func (ds *dnsservers) dial(ctx context.Context) (tlsConn *tls.Conn, err error) {
|
|
ds.RLock()
|
|
defer ds.RUnlock()
|
|
|
|
if dialer.Timeout != 0 {
|
|
var cancel context.CancelFunc
|
|
ctx, cancel = context.WithTimeout(ctx, dialer.Timeout)
|
|
defer cancel()
|
|
}
|
|
|
|
if !dialer.Deadline.IsZero() {
|
|
var cancel context.CancelFunc
|
|
ctx, cancel = context.WithDeadline(ctx, dialer.Deadline)
|
|
defer cancel()
|
|
}
|
|
|
|
var conn net.Conn
|
|
for host, addrs := range ds.m {
|
|
for _, addr := range addrs {
|
|
if !addr.E {
|
|
continue
|
|
}
|
|
conn, err = dialer.DialContext(ctx, "tcp", addr.A)
|
|
if err != nil {
|
|
addr.E = false // no need to acquire write lock
|
|
continue
|
|
}
|
|
tlsConn = tls.Client(conn, &tls.Config{ServerName: host})
|
|
err = terasu.Use(tlsConn).HandshakeContext(ctx)
|
|
if err == nil {
|
|
return
|
|
}
|
|
_ = tlsConn.Close()
|
|
addr.E = false // no need to acquire write lock
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
var dotv6servers = dnsservers{
|
|
m: map[string][]*dnsstat{
|
|
"dot.sb": {
|
|
{"[2a09::]:853", true},
|
|
{"[2a11::]:853", true},
|
|
},
|
|
"dns.google": {
|
|
{"[2001:4860:4860::8888]:853", true},
|
|
{"[2001:4860:4860::8844]:853", true},
|
|
},
|
|
"cloudflare-dns.com": {
|
|
{"[2606:4700:4700::1111]:853", true},
|
|
{"[2606:4700:4700::1001]:853", true},
|
|
},
|
|
"dns.umbrella.com": {
|
|
{"[2620:0:ccc::2]:853", true},
|
|
{"[2620:0:ccd::2]:853", true},
|
|
},
|
|
"dns10.quad9.net": {
|
|
{"[2620:fe::10]:853", true},
|
|
{"[2620:fe::fe:10]:853", true},
|
|
},
|
|
},
|
|
}
|
|
|
|
var dotv4servers = dnsservers{
|
|
m: map[string][]*dnsstat{
|
|
"dot.sb": {
|
|
{"185.222.222.222:853", true},
|
|
{"45.11.45.11:853", true},
|
|
},
|
|
"dns.google": {
|
|
{"8.8.8.8:853", true},
|
|
{"8.8.4.4:853", true},
|
|
},
|
|
"cloudflare-dns.com": {
|
|
{"1.1.1.1:853", true},
|
|
{"1.0.0.1:853", true},
|
|
},
|
|
"dns.umbrella.com": {
|
|
{"208.67.222.222:853", true},
|
|
{"208.67.220.220:853", true},
|
|
},
|
|
"dns10.quad9.net": {
|
|
{"9.9.9.10:853", true},
|
|
{"149.112.112.10:853", true},
|
|
},
|
|
},
|
|
}
|
|
|
|
var resolver = &net.Resolver{
|
|
PreferGo: true,
|
|
Dial: func(ctx context.Context, _, _ string) (net.Conn, error) {
|
|
if canUseIPv6.Get() {
|
|
return dotv6servers.dial(ctx)
|
|
}
|
|
return dotv4servers.dial(ctx)
|
|
},
|
|
}
|