Revamp Profile Domains and Ports to Endpoints and ServiceEndpoints

intel/reverse.go

@@ -0,0 +1,72 @@
+package intel
+
+import (
+	"errors"
+	"strings"
+
+	"github.com/Safing/portbase/log"
+	"github.com/miekg/dns"
+)
+
+// ResolveIPAndValidate finds (reverse DNS), validates (forward DNS) and returns the domain name assigned to the given IP.
+func ResolveIPAndValidate(ip string, securityLevel uint8) (domain string, err error) {
+	// get reversed DNS address
+	rQ, err := dns.ReverseAddr(ip)
+	if err != nil {
+		log.Tracef("intel: failed to get reverse address of %s: %s", ip, err)
+		return "", err
+	}
+
+	// get PTR record
+	rrCache := Resolve(rQ, dns.Type(dns.TypePTR), securityLevel)
+	if rrCache == nil {
+		return "", errors.New("querying for PTR record failed (may be NXDomain)")
+	}
+
+	// get result from record
+	var ptrName string
+	for _, rr := range rrCache.Answer {
+		ptrRec, ok := rr.(*dns.PTR)
+		if ok {
+			ptrName = ptrRec.Ptr
+			break
+		}
+	}
+
+	// check for nxDomain
+	if ptrName == "" {
+		return "", errors.New("no PTR record for IP (nxDomain)")
+	}
+
+	log.Infof("ptrName: %s", ptrName)
+
+	// get forward record
+	if strings.Contains(ip, ":") {
+		rrCache = Resolve(ptrName, dns.Type(dns.TypeAAAA), securityLevel)
+	} else {
+		rrCache = Resolve(ptrName, dns.Type(dns.TypeA), securityLevel)
+	}
+	if rrCache == nil {
+		return "", errors.New("querying for A/AAAA record failed (may be NXDomain)")
+	}
+
+	// check for matching A/AAAA record
+	log.Infof("rr: %s", rrCache)
+	for _, rr := range rrCache.Answer {
+		switch v := rr.(type) {
+		case *dns.A:
+			log.Infof("A: %s", v.A.String())
+			if ip == v.A.String() {
+				return ptrName, nil
+			}
+		case *dns.AAAA:
+			log.Infof("AAAA: %s", v.AAAA.String())
+			if ip == v.AAAA.String() {
+				return ptrName, nil
+			}
+		}
+	}
+
+	// no match
+	return "", errors.New("validation failed")
+}