Use server returned TTL for cache, instead of 600

This commit is contained in:
风扇滑翔翼 2024-09-15 13:37:57 +00:00 committed by GitHub
parent 83cffab45f
commit 9357bed8cf
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194

View File

@ -26,7 +26,7 @@ func ApplyECH(c *Config, config *tls.Config) error {
if err != nil {
return errors.New("invalid ECH config")
}
} else {
} else { // ECH config > DOH lookup
if c.ServerName == "" {
return errors.New("Using DOH for ECH needs serverName")
}
@ -58,54 +58,58 @@ func QueryRecord(domain string, server string) (string, error) {
}
mutex.Lock()
defer mutex.Unlock()
record, err := dohQuery(server, domain)
record, ttl, err := dohQuery(server, domain)
if err != nil {
return "", err
}
// Use TTL for good, but many HTTPS records have TTL 60, too short
if ttl < 600 {
ttl = 600
}
rec.record = record
rec.expire = time.Now().Add(time.Second * 600)
rec.expire = time.Now().Add(time.Second * time.Duration(ttl))
dnsCache[domain] = rec
return record, nil
}
func dohQuery(server string, domain string) (string, error) {
func dohQuery(server string, domain string) (string, uint32, error) {
m := new(dns.Msg)
m.SetQuestion(dns.Fqdn(domain), dns.TypeHTTPS)
msg, err := m.Pack()
if err != nil {
return "", err
return "", 0, err
}
client := &http.Client{
Timeout: 5 * time.Second,
}
req, err := http.NewRequest("POST", server, bytes.NewReader(msg))
if err != nil {
return "", err
return "", 0, err
}
req.Header.Set("Content-Type", "application/dns-message")
resp, err := client.Do(req)
if err != nil {
return "", err
return "", 0, err
}
defer resp.Body.Close()
respBody, err := io.ReadAll(resp.Body)
if err != nil {
return "", err
return "", 0, err
}
if resp.StatusCode != http.StatusOK {
return "", errors.New("query failed with response code:", resp.StatusCode)
return "", 0, errors.New("query failed with response code:", resp.StatusCode)
}
respMsg := new(dns.Msg)
err = respMsg.Unpack(respBody)
if err != nil {
return "", err
return "", 0, err
}
if len(respMsg.Answer) > 0 {
re := regexp.MustCompile(`ech="([^"]+)"`)
match := re.FindStringSubmatch(respMsg.Answer[0].String())
if match[1] != "" {
return match[1], nil
return match[1], respMsg.Answer[0].Header().Ttl, nil
}
}
return "", errors.New("no ech record found")
return "", 0, errors.New("no ech record found")
}