fix: EDNS cookies work properly (#98)

also slight refactors :)

closes #96

Co-authored-by: Sam Therapy <sam@samtherapy.net>
Reviewed-on: #98
Reviewed-by: grumbulon <grumbulon@grumbulon.xyz>

.goreleaser.yaml

@@ -13,9 +13,22 @@ builds:
       - linux
       - windows
       - darwin
+      - freebsd
     goarch:
       - amd64
+      - arm
       - arm64
+    ignore:
+      # Windows on ARM, maybe someday
+      - goos: windows
+        goarch: arm64
+      - goos: windows
+        goarch: arm
+
+      - goos: darwin
+        goarch: arm
+      - goos: freebsd
+        goarch: arm
 
 universal_binaries:
   - replace: true

GNUmakefile

@@ -9,6 +9,13 @@ else
 	EXE := $(PROG)
 endif
 
+doc/$(PROG).1: doc/$(PROG).1.scd
+	$(SCDOC) <$< >$@
+
+doc/wiki/$(PROG).1.md: doc/$(PROG).1
+	pandoc --from man --to gfm -o $@ $<
+
+
 ## install: installs awl
 .PHONY: install
 ifeq ($(OS),Windows_NT)

Makefile

@@ -5,6 +5,12 @@ include template.mk
 
 EXE := $(PROG)
 
+doc/$(PROG).1: doc/$(PROG).1.scd
+	$(SCDOC) <doc/$(PROG).1.scd >$@
+
+doc/wiki/$(PROG).1.md: doc/$(PROG).1
+	pandoc --from man --to gfm -o $@ doc/$(PROG).1
+
 ## install: installs awl
 .PHONY: install
 install: all

cli/cli.go

@@ -62,7 +62,8 @@ func ParseCLI(args []string, version string) (util.Options, error) {
 		subnet       = flag.String("subnet", "", "set EDNS client subnet")
 		padding      = flag.Bool("pad", false, "set EDNS padding")
 
-		truncate = flag.Bool("no-truncate", false, "ignore truncation if a UDP request truncates (default: retry with TCP)")
+		badCookie = flag.Bool("no-bad-cookie", false, "ignore BADCOOKIE EDNS responses (default: retry with correct cookie")
+		truncate  = flag.Bool("no-truncate", false, "ignore truncation if a UDP request truncates (default: retry with TCP)")
 
 		tcp      = flag.Bool("tcp", false, "use TCP")
 		dnscrypt = flag.Bool("dnscrypt", false, "use DNSCrypt")
@@ -126,6 +127,7 @@ func ParseCLI(args []string, version string) (util.Options, error) {
 		HTTPS:       *https,
 		QUIC:        *quic,
 		Truncate:    *truncate,
+		BadCookie:   *badCookie,
 		Reverse:     *reverse,
 		JSON:        *json,
 		XML:         *xml,

cli/dig.go

@@ -73,6 +73,8 @@ func ParseDig(arg string, opts *util.Options) error {
 		opts.TCP = isNo
 	case "ignore":
 		opts.Truncate = isNo
+	case "badcookie":
+		opts.BadCookie = !isNo
 	case "tls":
 		opts.TLS = isNo
 	case "dnscrypt":

cli/dig_test.go

@@ -40,6 +40,7 @@ func FuzzDig(f *testing.F) {
 		"tries=2", "tries=b", "tries",
 		"tcp", "vc", "notcp", "novc",
 		"ignore", "noignore",
+		"badcookie", "nobadcookie",
 		"tls", "notls",
 		"dnscrypt", "nodnscrypt",
 		"https", "nohttps",

cli/misc.go

@@ -29,7 +29,7 @@ func ParseMiscArgs(args []string, opts *util.Options) error {
 			switch {
 			case strings.HasPrefix(arg, "tls://"):
 				opts.TLS = true
-				opts.Request.Server = strings.TrimPrefix(opts.Request.Server, "tls://")
+				opts.Request.Server = strings.TrimPrefix(arg, "tls://")
 				opts.Logger.Info("DNS-over-TLS implicitly set")
 			case strings.HasPrefix(arg, "https://"):
 				opts.HTTPS = true
@@ -37,12 +37,18 @@ func ParseMiscArgs(args []string, opts *util.Options) error {
 				opts.Logger.Info("DNS-over-HTTPS implicitly set")
 			case strings.HasPrefix(arg, "quic://"):
 				opts.QUIC = true
-				opts.Request.Server = strings.TrimPrefix(opts.Request.Server, "quic://")
+				opts.Request.Server = strings.TrimPrefix(arg, "quic://")
 				opts.Logger.Info("DNS-over-QUIC implicitly set.")
 			case strings.HasPrefix(arg, "sdns://"):
 				opts.DNSCrypt = true
 				opts.Request.Server = arg
 				opts.Logger.Info("DNSCrypt implicitly set")
+			case strings.HasPrefix(arg, "tcp://"):
+				opts.TCP = true
+				opts.Request.Server = strings.TrimPrefix(arg, "udp://")
+				opts.Logger.Info("TCP implicitly set")
+			case strings.HasPrefix(arg, "udp://"):
+				opts.Request.Server = strings.TrimPrefix(arg, "udp://")
 			default:
 				opts.Request.Server = arg
 			}
@@ -117,7 +123,7 @@ func ParseMiscArgs(args []string, opts *util.Options) error {
 
 			if err != nil {
 				// :^)
-				opts.Logger.Warn("Could not query system for server. Using localhost")
+				opts.Logger.Warn("Could not query system for server. Using localhost\n", "Error:", err)
 				opts.Request.Server = "127.0.0.1"
 			} else {
 				// Make sure that if IPv4 or IPv6 is asked for it actually uses it

cli/misc_test.go

@@ -127,6 +127,8 @@ func TestFlagSetting(t *testing.T) {
 		{[]string{"@tls://dns.google"}},
 		{[]string{"@https://dns.cloudflare.com/dns-query"}},
 		{[]string{"@quic://dns.adguard.com"}},
+		{[]string{"@tcp://dns.froth.zone"}},
+		{[]string{"@udp://dns.example.com"}},
 	}
 
 	for i, test := range tests {
@@ -147,6 +149,10 @@ func TestFlagSetting(t *testing.T) {
 				assert.Assert(t, opts.HTTPS)
 			case 3:
 				assert.Assert(t, opts.QUIC)
+			case 4:
+				assert.Assert(t, opts.TCP)
+			case 5:
+				assert.Assert(t, true)
 			}
 		})
 	}

completions/zsh.zsh

@@ -13,6 +13,7 @@ local -a alts args
   '*+'{no,}'aaonly[set aa flag in the query]'
   '*+'{no,}'additional[print additional section of a reply]'
   '*+'{no,}'adflag[set the AD (authentic data) bit in the query]'
+  '*+'{no,}'badcookie[retry BADCOOKIE responses]'
   '*+'{no,}'cdflag[set the CD (checking disabled) bit in the query]'
   '*+'{no,}'cookie[add a COOKIE option to the request]'
   '*+edns=[specify EDNS version for query]:version (0-255)'

doc/awl.1.scd

@@ -80,6 +80,9 @@ Anything in [brackets] is optional.
 *--no-truncate*, *+ignore*
 	Ignore UDP truncation (by default, awl *retries with TCP*).
 
+*--no-bad-cookie*, *+[no]badcookie*
+	\[Do not\] ignore BADCOOKIE responses
+
 *--tcp*, *+tcp*, *+vc*
 	Use TCP for the query (see RFC 7766).
 

doc/wiki

@@ -1 +1 @@
-Subproject commit 6f3070f5933d0cc48bc8bb5290a1d0cc1825cd75
+Subproject commit d41f6197e638d7f0c0b203bd8b7f1fa0fc4b7f97

logawl/docs.go

@@ -14,7 +14,7 @@ because awl is a cli utility it writes directly to std err.
 // You can call specific logging levels from your new logger using
 //
 //	logger.Debug("Message to log")
-//	logger.Fatal("Message to log")
+//	logger.Warning("Message to log")
 //	logger.Info("Message to log")
 //	logger.Error("Message to log")
 //

query/general.go

@@ -52,13 +52,31 @@ func (r *StandardResolver) LookUp(msg *dns.Msg) (util.Response, error) {
 		}
 	}
 
-	r.opts.Logger.Debug("Using", dnsClient.Net, "for making the request")
+	r.opts.Logger.Info("Using", dnsClient.Net, "for making the request")
 
 	resp.DNS, resp.RTT, err = dnsClient.Exchange(msg, r.opts.Request.Server)
 	if err != nil {
 		return util.Response{}, fmt.Errorf("standard: DNS exchange: %w", err)
 	}
 
+	switch dns.RcodeToString[resp.DNS.MsgHdr.Rcode] {
+	case "BADCOOKIE":
+		if !r.opts.BadCookie {
+			fmt.Printf(";; BADCOOKIE, retrying.\n\n")
+
+			msg.Extra = resp.DNS.Extra
+
+			resp.DNS, resp.RTT, err = dnsClient.Exchange(msg, r.opts.Request.Server)
+
+			if err != nil {
+				return util.Response{}, fmt.Errorf("badcookie: DNS exchange: %w", err)
+			}
+		}
+
+	case "NOERR":
+		break
+	}
+
 	r.opts.Logger.Info("Request successful")
 
 	if resp.DNS.MsgHdr.Truncated && !r.opts.Truncate {

query/general_test.go

@@ -19,7 +19,7 @@ func TestResolve(t *testing.T) {
 		Logger: util.InitLogger(0),
 		Request: util.Request{
 			Server:  "8.8.4.1",
-			Port:    53,
+			Port:    1,
 			Type:    dns.TypeA,
 			Name:    "example.com.",
 			Timeout: time.Second / 2,

query/query.go

@@ -35,64 +35,64 @@ func CreateQuery(opts util.Options) (util.Response, error) {
 
 	// EDNS time :)
 	if opts.EDNS.EnableEDNS {
-		o := new(dns.OPT)
-		o.Hdr.Name = "."
-		o.Hdr.Rrtype = dns.TypeOPT
+		edns := new(dns.OPT)
+		edns.Hdr.Name = "."
+		edns.Hdr.Rrtype = dns.TypeOPT
 
-		o.SetVersion(opts.EDNS.Version)
+		edns.SetVersion(opts.EDNS.Version)
 
 		if opts.EDNS.Cookie {
-			e := new(dns.EDNS0_COOKIE)
-			e.Code = dns.EDNS0COOKIE
-			e.Cookie = uniuri.NewLenChars(8, []byte("1234567890abcdef"))
-			o.Option = append(o.Option, e)
+			cookie := new(dns.EDNS0_COOKIE)
+			cookie.Code = dns.EDNS0COOKIE
+			cookie.Cookie = uniuri.NewLenChars(16, []byte("1234567890abcdef"))
+			edns.Option = append(edns.Option, cookie)
 
-			opts.Logger.Info("Setting EDNS cookie to", e.Cookie)
+			opts.Logger.Info("Setting EDNS cookie to", cookie.Cookie)
 		}
 
 		if opts.EDNS.Expire {
-			o.Option = append(o.Option, new(dns.EDNS0_EXPIRE))
+			edns.Option = append(edns.Option, new(dns.EDNS0_EXPIRE))
 
 			opts.Logger.Info("Setting EDNS Expire option")
 		}
 
 		if opts.EDNS.KeepOpen {
-			o.Option = append(o.Option, new(dns.EDNS0_TCP_KEEPALIVE))
+			edns.Option = append(edns.Option, new(dns.EDNS0_TCP_KEEPALIVE))
 
 			opts.Logger.Info("Setting EDNS TCP Keepalive option")
 		}
 
 		if opts.EDNS.Nsid {
-			o.Option = append(o.Option, new(dns.EDNS0_NSID))
+			edns.Option = append(edns.Option, new(dns.EDNS0_NSID))
 
 			opts.Logger.Info("Setting EDNS NSID option")
 		}
 
 		if opts.EDNS.Padding {
-			o.Option = append(o.Option, new(dns.EDNS0_PADDING))
+			edns.Option = append(edns.Option, new(dns.EDNS0_PADDING))
 
 			opts.Logger.Info("Setting EDNS padding")
 		}
 
-		o.SetUDPSize(opts.EDNS.BufSize)
+		edns.SetUDPSize(opts.EDNS.BufSize)
 
 		opts.Logger.Info("EDNS UDP buffer set to", opts.EDNS.BufSize)
 
-		o.SetZ(opts.EDNS.ZFlag)
+		edns.SetZ(opts.EDNS.ZFlag)
 
 		opts.Logger.Info("EDNS Z flag set to", opts.EDNS.ZFlag)
 
 		if opts.EDNS.DNSSEC {
-			o.SetDo()
+			edns.SetDo()
 
 			opts.Logger.Info("EDNS DNSSEC OK set")
 		}
 
 		if opts.EDNS.Subnet.Address != nil {
-			o.Option = append(o.Option, &opts.EDNS.Subnet)
+			edns.Option = append(edns.Option, &opts.EDNS.Subnet)
 		}
 
-		req.Extra = append(req.Extra, o)
+		req.Extra = append(req.Extra, edns)
 	} else if opts.EDNS.DNSSEC {
 		req.SetEdns0(1232, true)
 		opts.Logger.Warn("DNSSEC implies EDNS, EDNS enabled")

template.mk

@@ -28,12 +28,6 @@ all: $(PROG) doc/$(PROG).1
 $(PROG): $(SOURCES)
 	$(GO) build -o $(EXE) $(GOFLAGS) .
 
-doc/$(PROG).1: doc/$(PROG).1.scd
-	$(SCDOC) <$< >$@
-
-doc/wiki/$(PROG).1.md: doc/$(PROG).1
-	pandoc --from man --to gfm -o $@ $<
-
 ## update_doc: update documentation (requires pandoc)
 update_doc: doc/wiki/$(PROG).1.md
 

util/options.go

@@ -27,6 +27,8 @@ type Options struct {
 	Display Display
 	// Ignore Truncation
 	Truncate bool `json:"ignoreTruncate" example:"false"`
+	// Ignore BADCOOKIE
+	BadCookie bool `json:"ignoreBadCookie" example:"false"`
 	// Print only the answer
 	Short bool `json:"short" example:"false"`
 	// When Short is true, display where the query came from