Fix dnstt-client not found: check current directory and improve error messages

Author: SamNet-dev

GUIDE.md

@@ -33,6 +33,51 @@ findns همه این‌ها را به صورت خودکار تست می‌کند
 
 **خیر!** findns به تنهایی تمام تست‌های DNS را انجام می‌دهد. فقط اگر بخواهید تست واقعی تانل (e2e) انجام دهید، به dnstt-client یا slipstream-client نیاز دارید. بدون آن‌ها هم اسکنر کامل کار می‌کند.
 
+### dnstt-client چیست و چطور نصبش کنم؟
+
+`dnstt-client` برنامه کلاینت پروژه [DNSTT](https://www.bamsoftware.com/software/dnstt/) است. این برنامه یک تانل DNS-over-UDP یا DNS-over-HTTPS درست می‌کند. findns از این برنامه برای **تست واقعی تانل** (e2e) استفاده می‌کند — یعنی واقعاً یک تانل می‌سازد و بررسی می‌کند اتصال برقرار می‌شود یا نه.
+
+**نصب با Go (ساده‌ترین روش):**
+
+</div>
+
+```bash
+go install www.bamsoftware.com/git/dnstt.git/dnstt-client@latest
+```
+
+<div dir="rtl">
+
+**دانلود دستی:**
+
+از [صفحه پروژه DNSTT](https://www.bamsoftware.com/software/dnstt/) باینری آماده دانلود کنید.
+
+**بعد از دانلود، حتماً فایل را در PATH قرار دهید:**
+
+</div>
+
+```bash
+# لینوکس/macOS:
+sudo mv dnstt-client /usr/local/bin/
+sudo chmod +x /usr/local/bin/dnstt-client
+
+# یا PATH را به پوشه فعلی اضافه کنید:
+export PATH=$PATH:$(pwd)
+```
+
+<div dir="rtl">
+
+> **نکته مهم:** فقط گذاشتن فایل کنار findns روی لینوکس **کافی نیست** مگر اینکه پوشه فعلی در PATH باشد. روی ویندوز این مشکل وجود ندارد.
+
+### کدام resolverها برای dnstt کار می‌کنند؟
+
+بدون فلگ `--pubkey` هم findns بررسی می‌کند کدام resolverها **قابلیت** کار با تانل DNS را دارند:
+
+- **resolve/tunnel**: بررسی می‌کند resolver می‌تواند NS record دامنه تانل شما را ببیند
+- **edns**: بررسی می‌کند سایز payload بزرگ (1232 بایت) پشتیبانی می‌شود
+- **nxdomain**: بررسی می‌کند resolver جواب جعلی نمی‌دهد
+
+resolverهایی که همه این مراحل را پاس کنند، **با احتمال بالا** برای dnstt کار می‌کنند. فلگ `--pubkey` فقط تأیید نهایی (e2e) را اضافه می‌کند.
+
 ---
 
 ## 2. نصب و راه‌اندازی

README.md

@@ -80,9 +80,13 @@ chmod +x findns-linux-amd64
 ### Requirements
 
 - **Go 1.24+** for building from source
-- **dnstt-client** in PATH (for e2e DNSTT tests)
-- **slipstream-client** in PATH (for e2e Slipstream tests)
-- **curl** in PATH (for e2e connectivity verification)
+- **dnstt-client** — only for e2e tunnel tests (`--pubkey`). Install: `go install www.bamsoftware.com/git/dnstt.git/dnstt-client@latest`
+- **slipstream-client** — only for e2e Slipstream tests (`--cert`)
+- **curl** — for e2e connectivity verification
+
+> **Important:** On Linux, you must place `dnstt-client` in PATH (e.g. `/usr/local/bin/`). Just putting it next to the scanner is not enough. Run: `sudo mv dnstt-client /usr/local/bin/ && sudo chmod +x /usr/local/bin/dnstt-client`
+>
+> Without `--pubkey`, the scanner still finds resolvers compatible with DNS tunneling — it tests ping, resolve, NXDOMAIN, EDNS, and tunnel delegation without needing dnstt-client.
 
 ---
 
@@ -634,9 +638,13 @@ go install github.com/SamNet-dev/findns/cmd@latest
 ### پیش‌نیازها
 
 - **Go 1.24+** برای بیلد از سورس
-- **dnstt-client** در PATH (برای تست e2e DNSTT)
-- **slipstream-client** در PATH (برای تست e2e Slipstream)
-- **curl** در PATH (برای تأیید اتصال e2e)
+- **dnstt-client** — فقط برای تست e2e تانل (`--pubkey`). نصب: `go install www.bamsoftware.com/git/dnstt.git/dnstt-client@latest`
+- **slipstream-client** — فقط برای تست e2e Slipstream (`--cert`)
+- **curl** — برای تأیید اتصال e2e
+
+> **مهم:** در لینوکس باید `dnstt-client` را در PATH قرار دهید (مثلاً `/usr/local/bin/`). فقط گذاشتن کنار اسکنر کافی نیست. اجرا کنید: `sudo mv dnstt-client /usr/local/bin/ && sudo chmod +x /usr/local/bin/dnstt-client`
+>
+> بدون `--pubkey` هم اسکنر resolverهای سازگار با تانل DNS را پیدا می‌کند (ping, resolve, nxdomain, edns, tunnel delegation بدون نیاز به dnstt-client).
 
 ---
 

cmd/chain.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"fmt"
-	"os/exec"
 	"strconv"
 	"strings"
 	"time"
@@ -51,7 +50,7 @@ func parseStepFlag(raw string) (stepConfig, error) {
 	return stepConfig{name: name, params: params}, nil
 }
 
-func buildStep(cfg stepConfig, defaultTimeout, defaultCount int, ports chan int) (scanner.Step, error) {
+func buildStep(cfg stepConfig, defaultTimeout, defaultCount int, ports chan int, binPaths map[string]string) (scanner.Step, error) {
 	stepTimeout := defaultTimeout
 	if v, ok := cfg.params["timeout"]; ok {
 		t, err := strconv.Atoi(v)
@@ -102,7 +101,7 @@ func buildStep(cfg stepConfig, defaultTimeout, defaultCount int, ports chan int)
 		if v, ok := cfg.params["test-url"]; ok {
 			testURL = v
 		}
-		return scanner.Step{Name: "e2e/dnstt", Timeout: dur, Check: scanner.DnsttCheck(domain, pubkey, testURL, ports), SortBy: "e2e_ms"}, nil
+		return scanner.Step{Name: "e2e/dnstt", Timeout: dur, Check: scanner.DnsttCheckBin(binPaths["dnstt-client"], domain, pubkey, testURL, ports), SortBy: "e2e_ms"}, nil
 
 	case "e2e/slipstream":
 		domain, ok := cfg.params["domain"]
@@ -114,7 +113,7 @@ func buildStep(cfg stepConfig, defaultTimeout, defaultCount int, ports chan int)
 		if v, ok := cfg.params["test-url"]; ok {
 			testURL = v
 		}
-		return scanner.Step{Name: "e2e/slipstream", Timeout: dur, Check: scanner.SlipstreamCheck(domain, cert, testURL, ports), SortBy: "e2e_ms"}, nil
+		return scanner.Step{Name: "e2e/slipstream", Timeout: dur, Check: scanner.SlipstreamCheckBin(binPaths["slipstream-client"], domain, cert, testURL, ports), SortBy: "e2e_ms"}, nil
 
 	case "nxdomain":
 		return scanner.Step{Name: "nxdomain", Timeout: dur, Check: scanner.NXDomainCheck(stepCount), SortBy: "hijack"}, nil
@@ -153,7 +152,7 @@ func buildStep(cfg stepConfig, defaultTimeout, defaultCount int, ports chan int)
 		if v, ok := cfg.params["test-url"]; ok {
 			testURL = v
 		}
-		return scanner.Step{Name: "doh/e2e", Timeout: dur, Check: scanner.DoHDnsttCheck(domain, pubkey, testURL, ports), SortBy: "e2e_ms"}, nil
+		return scanner.Step{Name: "doh/e2e", Timeout: dur, Check: scanner.DoHDnsttCheckBin(binPaths["dnstt-client"], domain, pubkey, testURL, ports), SortBy: "e2e_ms"}, nil
 
 	default:
 		return scanner.Step{}, fmt.Errorf("unknown step type %q", cfg.name)
@@ -175,20 +174,29 @@ func runChain(cmd *cobra.Command, args []string) error {
 	}
 
 	// Pre-flight: check required binaries for e2e steps
+	binPaths := make(map[string]string) // "dnstt-client" -> resolved path
 	for _, cfg := range configs {
 		switch cfg.name {
 		case "e2e/dnstt", "doh/e2e":
-			if _, err := exec.LookPath("dnstt-client"); err != nil {
-				return fmt.Errorf("step %q requires dnstt-client in PATH (not found)", cfg.name)
+			if _, ok := binPaths["dnstt-client"]; !ok {
+				bin, err := findBinary("dnstt-client")
+				if err != nil {
+					return fmt.Errorf("step %q requires dnstt-client: %w", cfg.name, err)
+				}
+				binPaths["dnstt-client"] = bin
 			}
-			if _, err := exec.LookPath("curl"); err != nil {
+			if _, err := findBinary("curl"); err != nil {
 				return fmt.Errorf("step %q requires curl in PATH (not found)", cfg.name)
 			}
 		case "e2e/slipstream":
-			if _, err := exec.LookPath("slipstream-client"); err != nil {
-				return fmt.Errorf("step %q requires slipstream-client in PATH (not found)", cfg.name)
+			if _, ok := binPaths["slipstream-client"]; !ok {
+				bin, err := findBinary("slipstream-client")
+				if err != nil {
+					return fmt.Errorf("step %q requires slipstream-client: %w", cfg.name, err)
+				}
+				binPaths["slipstream-client"] = bin
 			}
-			if _, err := exec.LookPath("curl"); err != nil {
+			if _, err := findBinary("curl"); err != nil {
 				return fmt.Errorf("step %q requires curl in PATH (not found)", cfg.name)
 			}
 		}
@@ -200,7 +208,7 @@ func runChain(cmd *cobra.Command, args []string) error {
 	// Build all steps
 	steps := make([]scanner.Step, 0, len(configs))
 	for _, cfg := range configs {
-		s, err := buildStep(cfg, timeout, count, ports)
+		s, err := buildStep(cfg, timeout, count, ports, binPaths)
 		if err != nil {
 			return err
 		}

cmd/doh_e2e.go

@@ -27,14 +27,19 @@ func runDoHE2E(cmd *cobra.Command, args []string) error {
 	pubkey, _ := cmd.Flags().GetString("pubkey")
 	testURL, _ := cmd.Flags().GetString("test-url")
 
+	bin, err := findBinary("dnstt-client")
+	if err != nil {
+		return err
+	}
+
 	urls, err := loadInput()
 	if err != nil {
 		return err
 	}
 
 	dur := time.Duration(e2eTimeout) * time.Second
 	ports := scanner.PortPool(30000, workers)
-	check := scanner.DoHDnsttCheck(domain, pubkey, testURL, ports)
+	check := scanner.DoHDnsttCheckBin(bin, domain, pubkey, testURL, ports)
 
 	start := time.Now()
 	results := scanner.RunPool(urls, workers, dur, check, newProgress("doh/e2e"))

cmd/e2e_dnstt.go

@@ -27,14 +27,19 @@ func runE2EDnstt(cmd *cobra.Command, args []string) error {
 	pubkey, _ := cmd.Flags().GetString("pubkey")
 	testURL, _ := cmd.Flags().GetString("test-url")
 
+	bin, err := findBinary("dnstt-client")
+	if err != nil {
+		return err
+	}
+
 	ips, err := loadInput()
 	if err != nil {
 		return err
 	}
 
 	dur := time.Duration(e2eTimeout) * time.Second
 	ports := scanner.PortPool(30000, workers)
-	check := scanner.DnsttCheck(domain, pubkey, testURL, ports)
+	check := scanner.DnsttCheckBin(bin, domain, pubkey, testURL, ports)
 
 	start := time.Now()
 	results := scanner.RunPool(ips, workers, dur, check, newProgress("e2e/dnstt"))

cmd/e2e_slipstream.go

@@ -26,14 +26,19 @@ func runE2ESlipstream(cmd *cobra.Command, args []string) error {
 	certPath, _ := cmd.Flags().GetString("cert")
 	testURL, _ := cmd.Flags().GetString("test-url")
 
+	bin, err := findBinary("slipstream-client")
+	if err != nil {
+		return err
+	}
+
 	ips, err := loadInput()
 	if err != nil {
 		return err
 	}
 
 	dur := time.Duration(e2eTimeout) * time.Second
 	ports := scanner.PortPool(30000, workers)
-	check := scanner.SlipstreamCheck(domain, certPath, testURL, ports)
+	check := scanner.SlipstreamCheckBin(bin, domain, certPath, testURL, ports)
 
 	start := time.Now()
 	results := scanner.RunPool(ips, workers, dur, check, newProgress("e2e/slipstream"))

cmd/root.go

@@ -3,6 +3,9 @@ package main
 import (
 	"fmt"
 	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
 	"time"
 
 	"github.com/SamNet-dev/findns/internal/scanner"
@@ -84,6 +87,37 @@ func writeReport(mode string, results []scanner.Result, elapsed time.Duration, s
 	return nil
 }
 
+// findBinary looks for a binary in PATH first, then in the current directory.
+// On Linux, exec.LookPath does NOT check the current directory, so users placing
+// dnstt-client next to the scanner get "not found". This fixes that.
+func findBinary(name string) (string, error) {
+	// Check PATH first
+	if p, err := exec.LookPath(name); err == nil {
+		return p, nil
+	}
+
+	// Check current directory
+	local := name
+	if runtime.GOOS == "windows" && filepath.Ext(name) == "" {
+		local = name + ".exe"
+	}
+	if abs, err := filepath.Abs(local); err == nil {
+		if _, err := os.Stat(abs); err == nil {
+			return abs, nil
+		}
+	}
+
+	hint := ""
+	switch name {
+	case "dnstt-client":
+		hint = "\n\nTo install dnstt-client:\n  go install www.bamsoftware.com/git/dnstt.git/dnstt-client@latest\n\nOr download from: https://www.bamsoftware.com/software/dnstt/"
+	case "slipstream-client":
+		hint = "\n\nDownload from: https://github.com/Mygod/slipstream-rust/releases"
+	}
+
+	return "", fmt.Errorf("%s not found in PATH or current directory.%s\n\nIf already downloaded, either:\n  1. Move it to a folder in PATH:  sudo mv %s /usr/local/bin/\n  2. Or add current directory to PATH:  export PATH=$PATH:$(pwd)", name, hint, name)
+}
+
 func isTTY() bool {
 	fi, err := os.Stderr.Stat()
 	if err != nil {

cmd/scan.go

@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 	"os"
-	"os/exec"
 	"sort"
 	"strings"
 	"time"
@@ -72,18 +71,23 @@ func runScan(cmd *cobra.Command, args []string) error {
 	}
 
 	// Pre-flight: verify required binaries before wasting time scanning
+	var dnsttBin, slipstreamBin string
 	if pubkey != "" {
-		if _, err := exec.LookPath("dnstt-client"); err != nil {
-			return fmt.Errorf("--pubkey requires dnstt-client in PATH (not found)")
+		bin, err := findBinary("dnstt-client")
+		if err != nil {
+			return fmt.Errorf("--pubkey requires dnstt-client: %w", err)
 		}
+		dnsttBin = bin
 	}
 	if certPath != "" {
-		if _, err := exec.LookPath("slipstream-client"); err != nil {
-			return fmt.Errorf("--cert requires slipstream-client in PATH (not found)")
+		bin, err := findBinary("slipstream-client")
+		if err != nil {
+			return fmt.Errorf("--cert requires slipstream-client: %w", err)
 		}
+		slipstreamBin = bin
 	}
-	if (pubkey != "" || certPath != "") {
-		if _, err := exec.LookPath("curl"); err != nil {
+	if pubkey != "" || certPath != "" {
+		if _, err := findBinary("curl"); err != nil {
 			return fmt.Errorf("e2e tests require curl in PATH (not found)")
 		}
 	}
@@ -111,7 +115,7 @@ func runScan(cmd *cobra.Command, args []string) error {
 		if domain != "" && pubkey != "" {
 			steps = append(steps, scanner.Step{
 				Name: "doh/e2e", Timeout: time.Duration(e2eTimeout) * time.Second,
-				Check: scanner.DoHDnsttCheck(domain, pubkey, testURL, ports), SortBy: "e2e_ms",
+				Check: scanner.DoHDnsttCheckBin(dnsttBin, domain, pubkey, testURL, ports), SortBy: "e2e_ms",
 			})
 		}
 	} else {
@@ -144,13 +148,13 @@ func runScan(cmd *cobra.Command, args []string) error {
 		if domain != "" && pubkey != "" {
 			steps = append(steps, scanner.Step{
 				Name: "e2e/dnstt", Timeout: time.Duration(e2eTimeout) * time.Second,
-				Check: scanner.DnsttCheck(domain, pubkey, testURL, ports), SortBy: "e2e_ms",
+				Check: scanner.DnsttCheckBin(dnsttBin, domain, pubkey, testURL, ports), SortBy: "e2e_ms",
 			})
 		}
 		if domain != "" && certPath != "" {
 			steps = append(steps, scanner.Step{
 				Name: "e2e/slipstream", Timeout: time.Duration(e2eTimeout) * time.Second,
-				Check: scanner.SlipstreamCheck(domain, certPath, testURL, ports), SortBy: "e2e_ms",
+				Check: scanner.SlipstreamCheckBin(slipstreamBin, domain, certPath, testURL, ports), SortBy: "e2e_ms",
 			})
 		}
 	}

internal/scanner/doh.go

@@ -174,8 +174,17 @@ func DoHTunnelCheck(domain string, count int) CheckFunc {
 	}
 }
 
+// DoHDnsttCheckBin is like DoHDnsttCheck but uses an explicit binary path.
+func DoHDnsttCheckBin(bin, domain, pubkey, testURL string, ports chan int) CheckFunc {
+	return dohDnsttCheck(bin, domain, pubkey, testURL, ports)
+}
+
 // DoHDnsttCheck runs an e2e test using dnstt-client in DoH mode.
 func DoHDnsttCheck(domain, pubkey, testURL string, ports chan int) CheckFunc {
+	return dohDnsttCheck("dnstt-client", domain, pubkey, testURL, ports)
+}
+
+func dohDnsttCheck(bin, domain, pubkey, testURL string, ports chan int) CheckFunc {
 	return func(url string, timeout time.Duration) (bool, Metrics) {
 		ctx, cancel := context.WithTimeout(context.Background(), timeout)
 		defer cancel()
@@ -190,7 +199,7 @@ func DoHDnsttCheck(domain, pubkey, testURL string, ports chan int) CheckFunc {
 
 		start := time.Now()
 
-		cmd := execCommandContext(ctx, "dnstt-client",
+		cmd := execCommandContext(ctx, bin,
 			"-doh", url,
 			"-pubkey", pubkey,
 			domain,