feat: Add DOH support

cmd/cli.go

@@ -68,10 +68,8 @@ func main() {
 			Destination: qFlags.QClasses,
 		},
 		&cli.BoolFlag{
-			Name:        "https",
-			Usage:       "Use the DNS-over-HTTPS protocol",
-			Destination: &qFlags.IsDOH,
-			DefaultText: "udp",
+			Name:  "https",
+			Usage: "Use the DNS-over-HTTPS protocol",
 		},
 		&cli.BoolFlag{
 			Name:        "verbose",

cmd/hub.go

@@ -39,6 +39,7 @@ func NewHub(logger *logrus.Logger, buildVersion string) *Hub {
 			QTypes:      cli.NewStringSlice(),
 			QClasses:    cli.NewStringSlice(),
 			Nameservers: cli.NewStringSlice(),
+			IsDOH:       false,
 		},
 	}
 	return hub

cmd/lookup.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/miekg/dns"
@@ -11,6 +12,7 @@ func (hub *Hub) Lookup(c *cli.Context) error {
 	hub.prepareQuestions()
 	err := hub.Resolver.Lookup(hub.Questions)
 	if err != nil {
+		fmt.Println(err)
 		hub.Logger.Error(err)
 	}
 	return nil

cmd/parse.go

@@ -8,7 +8,8 @@ import (
 )
 
 func (hub *Hub) loadQueryArgs(c *cli.Context) error {
-	err := hub.parseFreeArgs(c)
+	hub.loadTransportArgs(c)
+	err := hub.loadFreeArgs(c)
 	if err != nil {
 		cli.Exit("Error parsing arguments", -1)
 	}
@@ -20,14 +21,14 @@ func (hub *Hub) loadQueryArgs(c *cli.Context) error {
 	return err
 }
 
-// parseFreeArgs tries to parse all the arguments
+// loadFreeArgs tries to parse all the arguments
 // given to the CLI. These arguments don't have any specific
 // order so we have to deduce based on the pattern of argument.
 // For eg, a nameserver must always begin with `@`. In this
 // pattern we deduce the arguments and map it to internal query
 // options. In case an argument isn't able to fit in any of the existing
 // pattern it is considered to be a "query name".
-func (hub *Hub) parseFreeArgs(c *cli.Context) error {
+func (hub *Hub) loadFreeArgs(c *cli.Context) error {
 	for _, arg := range c.Args().Slice() {
 		if strings.HasPrefix(arg, "@") {
 			hub.QueryFlags.Nameservers.Set(strings.Trim(arg, "@"))
@@ -53,3 +54,11 @@ func (hub *Hub) loadFallbacks(c *cli.Context) {
 		hub.QueryFlags.QClasses.Set("IN")
 	}
 }
+
+// loadTransportArgs loads the query flags
+// for transport options.
+func (hub *Hub) loadTransportArgs(c *cli.Context) {
+	if c.Bool("https") {
+		hub.QueryFlags.IsDOH = true
+	}
+}

cmd/resolver.go

@@ -9,6 +9,20 @@ import (
 
 // loadResolver checks
 func (hub *Hub) loadResolver(c *cli.Context) error {
+	// check if DOH flag is set.
+	if hub.QueryFlags.IsDOH {
+		rslvr, err := resolvers.NewDOHResolver(hub.QueryFlags.Nameservers.Value())
+		if err != nil {
+			return err
+		}
+		hub.Resolver = rslvr
+		return nil
+	}
+	// check if DOT flag is set.
+
+	// check if TCP flag is set.
+
+	// fallback to good ol UDP.
 	if len(hub.QueryFlags.Nameservers.Value()) == 0 {
 		if runtime.GOOS == "windows" {
 			// TODO: Add a method for reading system default nameserver in windows.
@@ -18,10 +32,15 @@ func (hub *Hub) loadResolver(c *cli.Context) error {
 				return err
 			}
 			hub.Resolver = rslvr
+			return nil
 		}
 	} else {
-		rslvr := resolvers.NewResolver(hub.QueryFlags.Nameservers.Value())
+		rslvr, err := resolvers.NewClassicResolver(hub.QueryFlags.Nameservers.Value())
+		if err != nil {
+			return err
+		}
 		hub.Resolver = rslvr
+		return nil
 	}
 	return nil
 }