feat(sol): UDP + HTTP listener

magicpacket/magicpacket.go

@@ -0,0 +1,89 @@
+package magicpacket
+
+import (
+	"bytes"
+	"strings"
+)
+
+const (
+	// Magic packet format: 6 bytes of 0xFF followed by 16 repetitions of the MAC address
+	MagicPacketHeader     = 6
+	MacAddressRepetitions = 16
+	MacAddressLength      = 6
+	// Authentication format for UDP: "AUTH:username:password:" followed by magic packet
+	AuthPrefix = "AUTH:"
+)
+
+// IsMagicPacket checks if the received data is a valid Wake-on-LAN Magic Packet
+// Format: 6 bytes of 0xFF followed by 16 repetitions of the MAC address (6 bytes each)
+func IsMagicPacket(data []byte) bool {
+	// Minimum size: 6 (header) + 16*6 (MAC repetitions) = 102 bytes
+	minSize := MagicPacketHeader + (MacAddressRepetitions * MacAddressLength)
+	if len(data) < minSize {
+		return false
+	}
+
+	// Check for 6 bytes of 0xFF at the beginning
+	header := data[:MagicPacketHeader]
+	for _, b := range header {
+		if b != 0xFF {
+			return false
+		}
+	}
+
+	// Extract the MAC address (first 6 bytes after header)
+	macAddr := data[MagicPacketHeader : MagicPacketHeader+MacAddressLength]
+
+	// Check if the MAC address is repeated 16 times
+	for i := 1; i < MacAddressRepetitions; i++ {
+		offset := MagicPacketHeader + (i * MacAddressLength)
+		if offset+MacAddressLength > len(data) {
+			return false
+		}
+		repeatedMac := data[offset : offset+MacAddressLength]
+		if !bytes.Equal(macAddr, repeatedMac) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// ExtractAuthFromPacket extracts username and password from an authenticated packet
+// Format: "AUTH:username:password:" followed by standard magic packet
+// Returns username, password, magicPacketData, and success status
+func ExtractAuthFromPacket(data []byte) (string, string, []byte, bool) {
+	dataStr := string(data)
+
+	// Check for authentication prefix
+	if !strings.HasPrefix(dataStr, AuthPrefix) {
+		return "", "", nil, false
+	}
+
+	// Extract authentication part
+	authEnd := strings.Index(dataStr[len(AuthPrefix):], ":")
+	if authEnd == -1 {
+		return "", "", nil, false
+	}
+	authEnd += len(AuthPrefix)
+
+	// Extract username and password
+	authPart := dataStr[len(AuthPrefix):authEnd]
+	parts := strings.Split(authPart, ":")
+	if len(parts) != 2 {
+		return "", "", nil, false
+	}
+
+	username := parts[0]
+	password := parts[1]
+
+	// Extract magic packet part (after "AUTH:username:password:")
+	magicPacketStart := authEnd + 1
+	if magicPacketStart >= len(data) {
+		return "", "", nil, false
+	}
+
+	magicPacketData := data[magicPacketStart:]
+
+	return username, password, magicPacketData, true
+}