Add Zmodem/BINKP/EMSI

app/Classes/Protocol/BinkpMessage.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Classes\Protocol;
+
+final class BinkpMessage
+{
+	public const BLK_HDR_SIZE	= 2;						/* header size */
+
+	private int $id;
+	private string $body;
+
+	public function __construct(int $id,string $body)
+	{
+		$this->id = $id;
+		$this->body = $body;
+	}
+
+	public function __get($key)
+	{
+		switch ($key) {
+			case 'len':
+				return strlen($this->body)+1+self::BLK_HDR_SIZE;
+
+			case 'msg':
+				$buf = self::mkheader((strlen($this->body)+1) | 0x8000);
+				$buf .= chr($this->id);
+				$buf .= $this->body;
+
+				return $buf;
+
+			default:
+				throw new \Exception('Unknown key :'.$key);
+		}
+	}
+
+	public static function mkheader(int $l): string
+	{
+		$buf = chr(($l>>8)&0xff);
+		$buf .= chr($l&0xff);
+
+		return $buf;
+	}
+}