From: volpol <volpol@packet-gain.de>
Date: Sat, 16 Jun 2018 15:34:29 +0000 (+0200)
Subject: /hostip - query current IP address of user host
X-Git-Url: https://git.packet-gain.de/?a=commitdiff_plain;h=f582482cffbb62794cc2a5af34676a7329693816;p=ddnset.git

/hostip - query current IP address of user host
---

diff --git a/ddnset.go b/ddnset.go
index 416a9a7..4328d78 100644
--- a/ddnset.go
+++ b/ddnset.go
@@ -6,6 +6,7 @@ import (
 	"encoding/base64"
 	"flag"
 	"fmt"
+	"github.com/miekg/dns"
 	"io"
 	"io/ioutil"
 	"log"
@@ -17,16 +18,18 @@ import (
 )
 
 const (
-	DefaultAccFile    = "/usr/local/etc/ddnset/ddnset.acc"
-	DefaultZoneFile   = "/usr/local/etc/ddnset/ddnset.zon"
-	DefaultLogFile    = "/var/log/ddnset/default.log"
-	DefaultListenPort = 1980
+	DefaultAccFile      = "/usr/local/etc/ddnset/ddnset.acc"
+	DefaultZoneFile     = "/usr/local/etc/ddnset/ddnset.zon"
+	DefaultLogFile      = "/var/log/ddnset/default.log"
+	DefaultListenPort   = 1980
+	DefaultAuthorityDNS = "localhost"
 )
 
 var AccFile = flag.String("a", DefaultAccFile, "Path to account file")
 var ZoneFile = flag.String("z", DefaultZoneFile, "Path to zone file")
 var LogFile = flag.String("l", DefaultLogFile, "Path to log file")
 var ListenPort = flag.Uint("p", DefaultListenPort, "Port to listen on")
+var AuthorityDNS = flag.String("s", DefaultAuthorityDNS, "Authoritative name server")
 
 var Help = flag.Bool("h", false, "Show usage")
 
@@ -190,6 +193,50 @@ func knsupdate(host, ip, zone string, ver int) bool {
 	return true
 }
 
+func resolveWithAuthority(target, rectype string) string {
+	res := ""
+	c := dns.Client{}
+	m := dns.Msg{}
+
+	if rectype == "A" || rectype == "" {
+		m.SetQuestion(target+".", dns.TypeA)
+		r, _, err := c.Exchange(&m, *AuthorityDNS+":53")
+
+		if err == nil {
+			if len(r.Answer) == 0 {
+				log.Printf("%s. has no A record", target)
+			}
+
+			for _, ans := range r.Answer {
+				record := ans.(*dns.A)
+				log.Printf("%s. has IP %s", target, record.A)
+				res = res + record.A.String() + ","
+			}
+		} else {
+			log.Print(err)
+		}
+	}
+
+	if rectype == "AAAA" || rectype == "" {
+		m.SetQuestion(target+".", dns.TypeAAAA)
+		r, _, err := c.Exchange(&m, *AuthorityDNS+":53")
+
+		if err == nil {
+			if len(r.Answer) == 0 {
+				log.Print(target, ". has no AAAA record")
+			}
+			for _, ans := range r.Answer {
+				record := ans.(*dns.AAAA)
+				log.Printf("%s. has IPv6 %s", target, record.AAAA)
+				res = res + record.AAAA.String() + ","
+			}
+		} else {
+			log.Print(err)
+		}
+	}
+	return strings.TrimSuffix(res, ",")
+}
+
 func myipHandle(w http.ResponseWriter, r *http.Request) {
 	log.Print(r.RemoteAddr, " ", r.Method, " ", r.URL.String())
 	clientIP, _, err := net.SplitHostPort(r.RemoteAddr)
@@ -215,6 +262,8 @@ func rootHandle(w http.ResponseWriter, r *http.Request) {
 	//check auth
 	authok := false
 	hosts := ""
+	hostip := (r.URL.Path == "/hostip")
+
 	if hdr_auth, ok := r.Header["Authorization"]; ok {
 		log.Print("Authorization header present")
 		for _, auth := range hdr_auth {
@@ -240,16 +289,31 @@ func rootHandle(w http.ResponseWriter, r *http.Request) {
 	log.Print("User hosts: ", hosts)
 	//check ip
 	q := r.URL.Query()
+
+	myip := "0.0.0.0"
+	ver := 4
+	valid := false
+	myip_count := len(q["myip"])
+	log.Print("myips: ", myip_count)
+	if !hostip {
+		if myip_count == 1 {
+			myip, ver, valid = checkIP(q["myip"][0]) //one IP to rule them all
+		}
+		log.Printf("IP: %s (valid:%v, ver:%d)", myip, valid, ver)
+		if !valid {
+			log.Print("StatusBadIP")
+			io.WriteString(w, StatusBadIP+"\n")
+			return
+		}
+	}
+	//update or reportip
 	hostnames := q["hostname"]
-	myip, ver, valid := checkIP(q["myip"][0]) //one IP to rule them all
-	log.Printf("IP: %s (valid:%v, ver:%d)", myip, valid, ver)
-	if !valid {
-		log.Print("StatusBadIP")
-		io.WriteString(w, StatusBadIP+"\n")
-		return
+	rectype := ""
+	if len(q["rectype"]) == 1 {
+		rectype = q["rectype"][0]
 	}
-	//update
 	for _, host := range hostnames {
+		log.Print("Host:", host)
 		if !isDomainName(host) {
 			log.Print("StatusNotFQHN")
 			io.WriteString(w, StatusNotFQHN+"\n")
@@ -262,14 +326,18 @@ func rootHandle(w http.ResponseWriter, r *http.Request) {
 			continue
 		}
 		if strings.Contains(hosts, host) {
-			log.Printf("Updating %s to IP %s", host, myip)
-			updated := knsupdate(host, myip, zone, ver)
-			if updated {
-				log.Print("StatusGood")
-				io.WriteString(w, StatusGood+"\n")
+			if !hostip {
+				log.Printf("Updating %s to IP %s", host, myip)
+				updated := knsupdate(host, myip, zone, ver)
+				if updated {
+					log.Print("StatusGood")
+					io.WriteString(w, StatusGood+"\n")
+				} else {
+					log.Print("StatusBadDay")
+					io.WriteString(w, StatusBadDay+"\n")
+				}
 			} else {
-				log.Print("StatusBadDay")
-				io.WriteString(w, StatusBadDay+"\n")
+				io.WriteString(w, resolveWithAuthority(host, rectype)+"\n")
 			}
 		} else {
 			log.Print("StatusBadHost")
@@ -290,6 +358,7 @@ func main() {
 	http.HandleFunc("/myip", myipHandle)
 	http.HandleFunc("/myip.php", myipHandle)
 	http.HandleFunc("/", rootHandle)
+	http.HandleFunc("/hostip", rootHandle)
 	logf, err := os.OpenFile(*LogFile, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
 	if nil == err {
 		defer logf.Close()