begin work on OpenDNS resolver at www.openresolve.com

odns.go

@@ -0,0 +1,71 @@
+/**
+ * dingo: a DNS caching proxy written in Go
+ * This file implements an OpenDNS www.openresolve.com client
+ *
+ * Copyright (C) 2016 Pawel Foremski <[email protected]>
+ * Licensed under GNU GPL v3
+ */
+
+package main
+
+import "fmt"
+import "net/http"
+import "time"
+import "io/ioutil"
+import "encoding/json"
+import "crypto/tls"
+import "flag"
+import "github.com/miekg/dns"
+
+/* command-line arguments */
+var (
+	odns_workers = flag.Int("odns:workers", 0,
+		"OpenDNS: number of independent workers")
+	odns_server  = flag.String("odns:server", "67.215.70.81",
+		"OpenDNS: web server address")
+	odns_sni     = flag.String("odns:sni", "www.openresolve.com",
+		"OpenDNS: SNI string to send (should match server certificate)")
+)
+
+/**********************************************************************/
+
+func odns_start() {
+	for i := 0; i < *odns_workers; i++ { go odns_resolver(*odns_server) }
+}
+
+func odns_resolver(server string) {
+	/* setup the HTTP client */
+	var httpTr = http.DefaultTransport.(*http.Transport)
+	var tlsCfg = &tls.Config{ ServerName: *odns_sni }
+	httpTr.TLSClientConfig = tlsCfg;
+	var httpClient = &http.Client{ Timeout: time.Second*10, Transport: httpTr }
+
+	for q := range qchan {
+		/* make the new response object */
+		r := Reply{ Status: -1 }
+
+		/* prepare request, send proper HTTP 'Host:' header */
+		addr := fmt.Sprintf("https://%s/%s/%s", server, dns.Type(q.Type).String(), q.Name)
+		dbg(7, "  query: %s", addr)
+		hreq,_ := http.NewRequest("GET", addr, nil)
+		hreq.Host = "api.openresolve.com"
+
+		/* send the query */
+		resp,err := httpClient.Do(hreq)
+		if (err == nil) {
+			dbg(2, "[%s/%d] %s %s", q.Name, q.Type, resp.Status, resp.Proto)
+
+			/* read */
+			buf,_ := ioutil.ReadAll(resp.Body)
+			resp.Body.Close()
+			dbg(7, "  reply: %s", buf)
+
+			/* parse JSON? */
+			if (resp.StatusCode == 200) { json.Unmarshal(buf, &r) }
+			r.Now = time.Now()
+		} else { dbg(1, "[%s/%d] error: %s", q.Name, q.Type, err.Error()) }
+
+		/* write the reply */
+		*q.rchan <- r
+	}
+}