add reverse flag

natesales · Apr 21, 2021 · 439bb23 · 439bb23
1 parent 0067796
commit 439bb23
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diff --git a/README.md b/README.md
@@ -21,6 +21,7 @@ Application Options:
   -q, --qname=      Query name
   -s, --server=     DNS server
   -t, --type=       RR type
+  -x, --reverse     Reverse lookup
   -d, --dnssec      Request DNSSEC
   -r, --raw         Output raw DNS format
   -c, --chaos       Use CHAOS query class

diff --git a/main.go b/main.go
@@ -17,6 +17,7 @@ var opts struct {
 	Name      string   `short:"q" long:"qname" description:"Query name"`
 	Server    string   `short:"s" long:"server" description:"DNS server"`
 	Types     []string `short:"t" long:"type" description:"RR type"`
+	Reverse   bool     `short:"x" long:"reverse" description:"Reverse lookup"`
 	DNSSEC    bool     `short:"d" long:"dnssec" description:"Request DNSSEC"`
 	Raw       bool     `short:"r" long:"raw" description:"Output raw DNS format"`
 	Chaos     bool     `short:"c" long:"chaos" description:"Use CHAOS query class"`
@@ -108,6 +109,15 @@ func main() {
 		}
 	}
 
+	// Reverse address if required
+	if opts.Reverse {
+		opts.Name, err = dns.ReverseAddr(opts.Name)
+		if err != nil {
+			log.Fatal(err)
+		}
+		rrTypes = append(rrTypes, dns.StringToType["PTR"])
+	}
+
 	log.Debugf("qname %s", opts.Name)
 
 	// Create the upstream server