Docfix: cleanup

cmd/dpi-protocol-probe/main.go

@@ -1,3 +1,4 @@
+// Command dpi-protocol-probe for probing network server protocols.
 package main
 
 import (

protocol/detect/dns/detect.go

@@ -1,3 +1,12 @@
+// Package dns implements DNS protocol detection.
+//
+// This package doesn't expose any public functions, but registers itself for use in protocol detection.
+//
+// # How to use this package
+//
+// Import this package into your project in order to enable DNS protocol detection:
+//
+//	import _ "git.maze.io/go/dpi/protocol/detect/dns" // Register DNS protocol detection
 package dns
 
 import (
@@ -11,8 +20,8 @@ import (
 	"git.maze.io/go/dpi/protocol"
 )
 
-// Name is the DNS protocol name.
+// protocolName is the DNS protocol name.
-const Name = "dns"
+const protocolName = "dns"
 
 var (
 	classTypeScoreUnknown = -.15
@@ -47,10 +56,11 @@ var (
 func init() {
 	// Every DNS packet (query or answer) has a 12-byte header.
 	log.Println("register DetectDNS")
-	protocol.Register(protocol.Both, "????????????", DetectDNS)
+	protocol.Register(protocol.Both, "????????????", detectDNS)
 }
 
-func DetectDNS(dir protocol.Direction, data []byte, srcPort, dstPort int) (proto *protocol.Protocol, confidence float64) {
+// detectDNS can detect DNS queries and answersr from the provided data.
+func detectDNS(dir protocol.Direction, data []byte, srcPort, dstPort int) (proto *protocol.Protocol, confidence float64) {
 	log.Printf("detect dns: %q", hex.EncodeToString(data))
 
 	// Parsing using miekg/dns
@@ -146,6 +156,6 @@ func DetectDNS(dir protocol.Direction, data []byte, srcPort, dstPort int) (proto
 	// to exfiltrate data using malicious queries, etc.
 
 	return &protocol.Protocol{
-		Name: Name,
+		Name: protocolName,
 	}, confidence
 }

protocol/detect/dns/detect_test.go

@@ -72,8 +72,8 @@ func TestDetectDNS(t *testing.T) {
 			return
 		}
 		t.Logf("detected %s confidence %g%%", p.Name, c*100)
-		if p.Name != Name {
+		if p.Name != protocolName {
-			t.Errorf("expected %q protocol, got %q", Name, p.Name)
+			t.Errorf("expected %q protocol, got %q", protocolName, p.Name)
 		}
 	})
 
@@ -84,8 +84,8 @@ func TestDetectDNS(t *testing.T) {
 			return
 		}
 		t.Logf("detected %s confidence %g%%", p.Name, c*100)
-		if p.Name != Name {
+		if p.Name != protocolName {
-			t.Errorf("expected %q protocol, got %q", Name, p.Name)
+			t.Errorf("expected %q protocol, got %q", protocolName, p.Name)
 		}
 	})
 
@@ -96,8 +96,8 @@ func TestDetectDNS(t *testing.T) {
 			return
 		}
 		t.Logf("detected %s confidence %g%%", p.Name, c*100)
-		if p.Name != Name {
+		if p.Name != protocolName {
-			t.Errorf("expected %q protocol, got %q", Name, p.Name)
+			t.Errorf("expected %q protocol, got %q", protocolName, p.Name)
 		}
 	})
 
@@ -108,8 +108,8 @@ func TestDetectDNS(t *testing.T) {
 			return
 		}
 		t.Logf("detected %s confidence %g%%", p.Name, c*100)
-		if p.Name != Name {
+		if p.Name != protocolName {
-			t.Errorf("expected %q protocol, got %q", Name, p.Name)
+			t.Errorf("expected %q protocol, got %q", protocolName, p.Name)
 		}
 	})
 }

protocol/match.go

@@ -2,12 +2,12 @@ package protocol
 
 // Match the input against the magic string pattern.
 //
-// '?' matches any single character
+//   - '?' matches any single character
-// '*' matches zero or more characters
+//   - '*' matches zero or more characters
-// '\' escapes special characters ('?', '*', '\')
+//   - '\' escapes special characters ('?', '*', '\')
-// All other characters must match exactly
+//   - all other characters must match exactly
 //
-// Returns true if all magic bytes are matched, even if input has extra bytes.
+// Returns true if all magic bytes are matched, even if the input has extra bytes.
 func Match(magic string, input []byte) bool {
 	if len(magic) == 0 {
 		return true

protocol/match_example_test.go

@@ -0,0 +1,20 @@
+package protocol_test
+
+import (
+	"fmt"
+
+	"git.maze.io/go/dpi/protocol"
+)
+
+func ExampleMatch() {
+	fmt.Println(protocol.Match("t?s?", []byte("test")))
+	fmt.Println(protocol.Match("t?s?", []byte("test with more data")))
+	fmt.Println(protocol.Match("t?s?", []byte("text with more data")))
+	fmt.Println(protocol.Match("select * from user", []byte("select an apple from user")))
+	fmt.Println(protocol.Match("select * from user", []byte("select an apple from the user")))
+	// Output: true
+	// true
+	// false
+	// true
+	// false
+}