Fix testing on windows, add better Plan 9 support

Signed-off-by: Sam Therapy <sam@samtherapy.net>

cli.go

@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: BSD-3-Clause
+
 package main
 
 import (

cli_test.go

@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: BSD-3-Clause
+
 package main
 
 import (

conf/notwin.go

@@ -7,7 +7,6 @@ package conf
 import (
 	"os"
 	"runtime"
-	"strings"
 
 	"github.com/miekg/dns"
 )
@@ -24,29 +23,3 @@ func GetDNSConfig() (*dns.ClientConfig, error) {
 		return dns.ClientConfigFromFile("/etc/resolv.conf")
 	}
 }
-
-// Plan 9 stores its network data in /net/ndb, which seems to be formatted a specific way
-func getPlan9Config(str string) (*dns.ClientConfig, error) {
-	str = strings.ReplaceAll(str, "\n", "")
-	spl := strings.FieldsFunc(str, split)
-	servers := []string{}
-	for _, option := range spl {
-		if strings.HasPrefix(option, "dns=") {
-			servers = append(servers, strings.TrimPrefix(option, "dns="))
-		}
-	}
-
-	// TODO: read more about how customizable Plan 9 is
-	return &dns.ClientConfig{
-		Servers:  servers,
-		Search:   []string{},
-		Port:     "53",
-		Ndots:    1,
-		Timeout:  5,
-		Attempts: 1,
-	}, nil
-}
-
-func split(r rune) bool {
-	return r == ' ' || r == '\t'
-}

conf/notwin_test.go

@@ -1,18 +0,0 @@
-// SPDX-License-Identifier: BSD-3-Clause
-package conf
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestGetPlan9Config(t *testing.T) {
-	ndb := `ip=192.168.122.45 ipmask=255.255.255.0 ipgw=192.168.122.1
-	sys=chog9
-	dns=192.168.122.1`
-
-	act, err := getPlan9Config(ndb)
-	assert.Nil(t, err)
-	assert.Equal(t, act.Servers[0], "192.168.122.1")
-}

conf/plan9.go

@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: BSD-3-Clause
+
+package conf
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/miekg/dns"
+)
+
+// Plan 9 stores its network data in /net/ndb, which seems to be formatted a specific way
+// Yoink it and use it.
+//
+// See ndb(7).
+func getPlan9Config(str string) (*dns.ClientConfig, error) {
+	str = strings.ReplaceAll(str, "\n", "")
+	spl := strings.FieldsFunc(str, splitChars)
+	var servers []string
+	for _, option := range spl {
+		if strings.HasPrefix(option, "dns=") {
+			servers = append(servers, strings.TrimPrefix(option, "dns="))
+		}
+	}
+	if len(servers) == 0 {
+		return nil, fmt.Errorf("plan9: no DNS servers found")
+	}
+
+	// TODO: read more about how customizable Plan 9 is
+	return &dns.ClientConfig{
+		Servers: servers,
+		Search:  []string{},
+		Port:    "53",
+	}, nil
+}
+
+// Split the string at either space or tabs
+func splitChars(r rune) bool {
+	return r == ' ' || r == '\t'
+}

conf/plan9_test.go

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: BSD-3-Clause
+
+package conf
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetPlan9Config(t *testing.T) {
+	ndbs := []struct {
+		in   string
+		want string
+	}{
+		{`ip=192.168.122.45 ipmask=255.255.255.0 ipgw=192.168.122.1
+	sys=chog9
+	dns=192.168.122.1`, "192.168.122.1"},
+		{`ipnet=murray-hill ip=135.104.0.0 ipmask=255.255.0.0
+	dns=135.104.10.1
+	ntp=ntp.cs.bell-labs.com
+	ipnet=plan9 ip=135.104.9.0 ipmask=255.255.255.0
+	ntp=oncore.cs.bell-labs.com
+	smtp=smtp1.cs.bell-labs.com
+	ip=135.104.9.6 sys=anna dom=anna.cs.bell-labs.com
+	smtp=smtp2.cs.bell-labs.com`, "135.104.10.1"},
+	}
+
+	for _, ndb := range ndbs {
+		act, err := getPlan9Config(ndb.in)
+		assert.Nil(t, err)
+		assert.Equal(t, ndb.want, act.Servers[0])
+	}
+
+	invalid := `sys = spindle
+	dom=spindle.research.bell-labs.com
+	bootf=/mips/9powerboot
+	ip=135.104.117.32 ether=080069020677
+	proto=il`
+
+	act, err := getPlan9Config(invalid)
+	assert.ErrorContains(t, err, "no DNS servers found")
+	assert.Nil(t, act)
+
+}

go.mod

@@ -30,7 +30,7 @@ require (
 	github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 // indirect
 	golang.org/x/crypto v0.0.0-20220622213112-05595931fe9d // indirect
 	golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 // indirect
-	golang.org/x/sys v0.0.0-20220627191245-f75cf1eec38b // indirect
+	golang.org/x/sys v0.0.0-20220627191245-f75cf1eec38b
 	golang.org/x/text v0.3.7 // indirect
 	golang.org/x/tools v0.1.11 // indirect
 	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 // indirect