Add examples

Completely modules after the examples of ldns.
Fist example is 'mx', print out the MX records of a domain.
More are coming, each is used to fine-tune the dns api

Changes

@@ -1,12 +0,0 @@
-Add resolver type and use the for querying
-IPv6 support
-DNSSEC support
-uint8 support
-base64 support (only for unpacking atm)
-hex support
-Split of the type definition into dnstypes.go
-
-make should build the package
-
-make restest
-builds a small sample program

Makefile

@@ -14,15 +14,14 @@ GOFILES=\
 
 include $(GOROOT)/src/Make.pkg
 
-p: restest manglertest ednstest dnssectest ednstest2
+.PHONY: examples
+
+examples:
+	(cd examples; make)
+
+progs: manglertest dnssectest
 
 # too lazy to lookup how this works again in Makefiles
-restest: restest.go $(GOFILES)
-	6g -I _obj restest.go && 6l -L _obj -o restest restest.6
-
-ednstest: ednstest.go $(GOFILES)
-	6g -I _obj ednstest.go && 6l -L _obj -o ednstest ednstest.6
-
 manglertest: manglertest.go $(GOFILES)
 	6g -I _obj manglertest.go && 6l -L _obj -o manglertest manglertest.6
 

ednstest.go

@@ -1,36 +0,0 @@
-package main
-
-// Test EDNS RR records
-import (
-        "fmt"
-        "dns"
-)
-
-func main() {
-        sig := new(dns.RR_RRSIG)
-        sig.Hdr.Name = "miek.nl."
-        sig.Hdr.Rrtype = dns.TypeRRSIG
-        sig.Hdr.Class = dns.ClassINET
-        sig.Hdr.Ttl = 3600
-        sig.TypeCovered = dns.TypeDNSKEY
-        sig.Algorithm = dns.AlgRSASHA1
-        sig.Labels = 2
-        sig.OrigTtl = 4000
-        sig.Expiration = 1000
-        sig.Inception = 800
-        sig.KeyTag = 34641
-        sig.SignerName = "miek.nl."
-        sig.Sig = "AwEAAaHIwpx3w4VHKi6i1LHnTaWeHCL154Jug0Rtc9ji5qwPXpBo6A5sRv7cSsPQKPIwxLpyCrbJ4mr2L0EPOdvP6z6YfljK2ZmTbogU9aSU2fiq/4wjxbdkLyoDVgtO+JsxNN4bjr4WcWhsmk1Hg93FV9ZpkWb0Tbad8DFqNDzr//kZ"
-
-        fmt.Printf("%v\n", sig)
-
-        edns := new(dns.RR_OPT)
-        edns.Hdr.Name = "miek.nl."
-        edns.Hdr.Rrtype = dns.TypeOPT
-        edns.Hdr.Class = dns.ClassINET
-        edns.Hdr.Ttl = 3600
-        edns.Option = make([]dns.Option, 1)
-        edns.Option[0].Code = dns.OptionCodeNSID
-        edns.Option[0].Data = "lalalala"
-        fmt.Printf("%v\n", edns)
-}

examples/Makefile

@@ -0,0 +1,9 @@
+# Copyright 2009 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+all: mx
+
+# too lazy to lookup how this works again in Makefiles
+mx: mx.go
+	6g -I ../_obj mx.go && 6l -L ../_obj -o mx mx.6

examples/mx.go

@@ -0,0 +1,42 @@
+package main
+
+// Print the MX records of a domain
+import (
+	"dns"
+        "os"
+        "fmt"
+)
+
+func main() {
+	r := new(dns.Resolver)
+	qr := dns.NewQuerier(r)
+        r.Servers = []string{"127.0.0.1"}
+        r.Timeout = 2
+        r.Attempts = 1
+
+        if len(os.Args) != 2 {
+                fmt.Printf("%s DOMAIN\n", os.Args[0])
+                os.Exit(1)
+        }
+
+        m := new(dns.Msg)
+        m.MsgHdr.Recursion_desired = true //only set this bit
+        m.Question = make([]dns.Question, 1)
+        m.Question[0] = dns.Question{os.Args[1], dns.TypeMX, dns.ClassINET}
+
+        qr <- dns.DnsMsg{m, nil}
+        in := <-qr
+
+        if in.Dns.Rcode != dns.RcodeSuccess {
+                fmt.Printf(" *** invalid answer name %s after MX query for %s\n", os.Args[1], os.Args[1])
+                os.Exit(1)
+        }
+        // Stuff must be in the answer section
+        for _, a := range in.Dns.Answer {
+                fmt.Printf("%v\n", a)
+        }
+
+        // Stop the resolver, send it a null mesg
+        qr <- dns.DnsMsg{nil, nil}
+        <-qr
+}

resolver.go

@@ -6,6 +6,7 @@
 // A dns resolver is to be run as a seperate goroutine. 
 // For every reply the resolver answers by sending the
 // received packet back on the channel.
+// TODO: resolverFromConf (/etc/resolv.conf) parsing??
 
 package dns
 
@@ -55,6 +56,8 @@ func query(res *Resolver, msg chan DnsMsg) {
 		case out := <-msg: //msg received
 			if out.Dns == nil {
 				// nil message, quit the goroutine
+                                msg <- DnsMsg{nil, nil}
+                                close(msg)
 				return
 			}
 

resolverEdns_test.go

@@ -2,7 +2,6 @@ package dns
 
 import (
 	"testing"
-	"time"
 )
 
 func TestResolverEdns(t *testing.T) {
@@ -42,5 +41,5 @@ func TestResolverEdns(t *testing.T) {
 		t.Fail()
 	}
 	ch <- DnsMsg{nil, nil}
-	time.Sleep(0.5e9)
+        <-ch
 }

resolver_test.go

@@ -2,7 +2,6 @@ package dns
 
 import (
 	"testing"
-	"time"
 )
 
 
@@ -41,5 +40,5 @@ func TestResolver(t *testing.T) {
 	}
 
 	ch <- DnsMsg{nil, nil}
-	time.Sleep(0.5e9)
+        <-ch
 }

restest.go

@@ -1,38 +0,0 @@
-package main
-
-import (
-	"dns"
-	"time"
-	"fmt"
-)
-
-const (
-	NLOOP = 5
-)
-
-func main() {
-	res := new(dns.Resolver)
-	ch  := dns.NewQuerier(res)
-
-	// configure the resolver
-	res.Servers = []string{"192.168.1.2"}
-	res.Timeout = 2
-	res.Attempts = 1
-
-	// Setup done, now for some real work
-	// Create a new message
-	m := new(dns.Msg)
-	m.MsgHdr.Recursion_desired = true //only set this bit
-	m.Question = make([]dns.Question, 1)
-
-	m.Question[0] = dns.Question{"pa1ton.nl", dns.TypeDS, dns.ClassINET}
-	ch <- dns.DnsMsg{m, nil}
-
-	// wait for an reply
-	in := <-ch
-	fmt.Printf("%v\n", in.Dns)
-
-	ch <- dns.DnsMsg{nil, nil}
-
-	time.Sleep(2.0e9) // wait for Go routine to do something
-}