Refactored detection logic to include ports and a confidence score

protocol/match.go

@@ -0,0 +1,77 @@
+package protocol
+
+// MatchPattern checks if the byte slice matches the magic string pattern.
+//
+// '?' matches any single character
+// '*' matches zero or more characters
+// '\' escapes special characters ('?', '*', '\')
+// All other characters must match exactly
+//
+// Returns true if all magic bytes are matched, even if input has extra bytes.
+func Match(magic string, input []byte) bool {
+	return match(magic, input, 0, 0)
+}
+
+// match is a recursive helper function that implements the matching logic
+func match(magic string, input []byte, magicIndex, inputIndex int) bool {
+	// If we've reached the end of magic string, we've successfully matched all magic bytes
+	// It doesn't matter if there are extra bytes in the input
+	if magicIndex == len(magic) {
+		return true
+	}
+
+	// Handle escape character
+	if magic[magicIndex] == '\\' {
+		// Check if there's a next character in magic
+		if magicIndex+1 >= len(magic) {
+			// Backslash at end of magic string - treat as literal backslash
+			if inputIndex >= len(input) || input[inputIndex] != '\\' {
+				return false
+			}
+			return match(magic, input, magicIndex+1, inputIndex+1)
+		}
+
+		// Escape the next character - we need to match it literally
+		escapedChar := magic[magicIndex+1]
+		if inputIndex >= len(input) || input[inputIndex] != escapedChar {
+			return false
+		}
+		// Skip both the backslash and the escaped character in magic, move one in input
+		return match(magic, input, magicIndex+2, inputIndex+1)
+	}
+
+	// If we've reached the end of input but not magic string
+	if inputIndex == len(input) {
+		// If we have '*' at the current position, it can match zero characters
+		if magic[magicIndex] == '*' {
+			return match(magic, input, magicIndex+1, inputIndex)
+		}
+		return false
+	}
+
+	// Handle '*' character - matches zero or more characters
+	if magic[magicIndex] == '*' {
+		// Try matching zero characters
+		if match(magic, input, magicIndex+1, inputIndex) {
+			return true
+		}
+		// Try matching one or more characters
+		if inputIndex < len(input) && match(magic, input, magicIndex, inputIndex+1) {
+			return true
+		}
+		return false
+	}
+
+	// Handle '?' character - matches any single character
+	if magic[magicIndex] == '?' {
+		return match(magic, input, magicIndex+1, inputIndex+1)
+	}
+
+	// Handle exact character match
+	if magic[magicIndex] == input[inputIndex] {
+		return match(magic, input, magicIndex+1, inputIndex+1)
+	}
+
+	// No match found
+	return false
+}