实现DNS域名验证

internal/utils/lookup.go

@@ -0,0 +1,123 @@
+package utils
+
+import (
+	"github.com/TeaOSLab/EdgeCommon/pkg/configutils"
+	"github.com/miekg/dns"
+)
+
+// LookupCNAME 查询CNAME记录
+// TODO 可以设置使用的DNS主机地址
+func LookupCNAME(host string) (string, error) {
+	config, err := dns.ClientConfigFromFile("/etc/resolv.conf")
+	if err != nil {
+		return "", err
+	}
+
+	var c = new(dns.Client)
+	var m = new(dns.Msg)
+
+	m.SetQuestion(host+".", dns.TypeCNAME)
+	m.RecursionDesired = true
+
+	var lastErr error
+	for _, serverAddr := range config.Servers {
+		r, _, err := c.Exchange(m, configutils.QuoteIP(serverAddr)+":"+config.Port)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		if len(r.Answer) == 0 {
+			continue
+		}
+
+		return r.Answer[0].(*dns.CNAME).Target, nil
+	}
+	return "", lastErr
+}
+
+// LookupNS 查询NS记录
+// TODO 可以设置使用的DNS主机地址
+func LookupNS(host string) ([]string, error) {
+	config, err := dns.ClientConfigFromFile("/etc/resolv.conf")
+	if err != nil {
+		return nil, err
+	}
+
+	var c = new(dns.Client)
+	var m = new(dns.Msg)
+
+	m.SetQuestion(host+".", dns.TypeNS)
+	m.RecursionDesired = true
+
+	var result = []string{}
+
+	var lastErr error
+	var hasValidServer = false
+	for _, serverAddr := range config.Servers {
+		r, _, err := c.Exchange(m, configutils.QuoteIP(serverAddr)+":"+config.Port)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+
+		hasValidServer = true
+
+		if len(r.Answer) == 0 {
+			continue
+		}
+
+		for _, answer := range r.Answer {
+			result = append(result, answer.(*dns.NS).Ns)
+		}
+		break
+	}
+
+	if hasValidServer {
+		return result, nil
+	}
+
+	return nil, lastErr
+}
+
+// LookupTXT 获取CNAME
+// TODO 可以设置使用的DNS主机地址
+func LookupTXT(host string) ([]string, error) {
+	config, err := dns.ClientConfigFromFile("/etc/resolv.conf")
+	if err != nil {
+		return nil, err
+	}
+
+	var c = new(dns.Client)
+	var m = new(dns.Msg)
+
+	m.SetQuestion(host + ".", dns.TypeTXT)
+	m.RecursionDesired = true
+
+	var lastErr error
+	var result = []string{}
+	var hasValidServer = false
+	for _, serverAddr := range config.Servers {
+		r, _, err := c.Exchange(m, configutils.QuoteIP(serverAddr)+":"+config.Port)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		hasValidServer = true
+
+		if len(r.Answer) == 0 {
+			continue
+		}
+
+		for _, answer := range r.Answer {
+			result = append(result, answer.(*dns.TXT).Txt...)
+		}
+
+		break
+	}
+
+	if hasValidServer {
+		return result, nil
+	}
+
+	return nil, lastErr
+}