Merge pull request #32 from graze/add-max-character-read

Add max read characters
graze · Dec 11, 2020 · 543f5f0 · 543f5f0
2 parents b8091d6 + 87b9201
commit 543f5f0
Show file tree

Hide file tree

Showing 2 changed files with 69 additions and 8 deletions.
diff --git a/src/TelnetClient.php b/src/TelnetClient.php
@@ -52,6 +52,11 @@ class TelnetClient implements TelnetClientInterface
      */
     protected $lineEnding = "\n";
 
+    /**
+     * @var int
+     */
+    protected $maxBytesRead = 0;
+
     /**
      * @var Socket
      */
@@ -151,6 +156,16 @@ public function setLineEnding($lineEnding)
         $this->lineEnding = $lineEnding;
     }
 
+    /**
+     * Set the maximum number of bytes that can be read per request
+     *
+     * @param int $maxBytesRead
+     */
+    public function setMaxBytesRead($maxBytesRead)
+    {
+        $this->maxBytesRead = $maxBytesRead;
+    }
+
     /**
      * @param Socket $socket
      */
@@ -225,23 +240,25 @@ protected function getResponse($prompt = null, $promptError = null)
     {
         $isError = false;
         $buffer = '';
+        $bytesRead = 0;
         do {
-            // process one character at a time
+            // process one byte at a time
             try {
-                $character = $this->socket->read(1);
+                $byte = $this->socket->read(1);
+                $bytesRead++;
             } catch (Exception $e) {
                 throw new TelnetException('failed reading from socket', 0, $e);
             }
 
-            if (in_array($character, [$this->NULL, $this->DC1])) {
+            if (in_array($byte, [$this->NULL, $this->DC1])) {
                 break;
             }
 
-            if ($this->interpretAsCommand->interpret($character, $this->socket)) {
+            if ($this->interpretAsCommand->interpret($byte, $this->socket)) {
                 continue;
             }
 
-            $buffer .= $character;
+            $buffer .= $byte;
 
             // check for prompt
             if ($this->promptMatcher->isMatch($prompt ?: $this->prompt, $buffer, $this->lineEnding)) {
@@ -253,6 +270,15 @@ protected function getResponse($prompt = null, $promptError = null)
                 $isError = true;
                 break;
             }
+
+            // throw an exception if the number of bytes read is greater than the limit
+            if ($this->maxBytesRead > 0 && $bytesRead >= $this->maxBytesRead) {
+                throw new TelnetException(sprintf(
+                    'Maximum number of bytes read (%d), the last bytes were %s',
+                    $this->maxBytesRead,
+                    substr($buffer, -10)
+                ));
+            }
         } while (true);
 
         return new TelnetResponse(

diff --git a/tests/unit/TelnetClientTest.php b/tests/unit/TelnetClientTest.php
@@ -122,7 +122,7 @@ public function testExecute(
             ->with($command.$lineEnding)
             ->once();
 
-        // echo the command back when reading each character one-by-one from the socket
+        // echo the command back when reading each byte one-by-one from the socket
         $commandResponse = str_split($command.$lineEnding.$promptResponse.$lineEnding);
         $socket = $socket
             ->shouldReceive('read')
@@ -190,7 +190,7 @@ public function testExecutePromptError(
             ->with($command.$lineEnding)
             ->once();
 
-        // echo the command back when reading each character one-by-one from the socket
+        // echo the command back when reading each byte one-by-one from the socket
         $commandResponse = str_split($command.$lineEnding.$promptResponse.$lineEnding);
         $socket = $socket
             ->shouldReceive('read')
@@ -271,7 +271,7 @@ public function testWriteException()
 
     public function testReadException()
     {
-        $this->setExpectedException(TelnetExceptionInterface::class);
+        $this->setExpectedException(TelnetExceptionInterface::class, 'failed reading from socket');
 
         $client = m::mock(TelnetClient::class)->makePartial();
 
@@ -286,6 +286,41 @@ public function testReadException()
         $client->execute('aCommand');
     }
 
+    public function testMaxBytesReadException()
+    {
+        $this->setExpectedException(
+            TelnetExceptionInterface::class, 
+            'Maximum number of bytes read (20), the last bytes were 0123456789'
+        );
+
+        $socket = m::mock(Socket::class)
+            ->shouldReceive('write')
+            ->shouldReceive('close')
+            ->shouldReceive('read');
+
+        call_user_func_array([$socket, 'andReturn'], str_split('0123456789012345678912'));
+        $socket = $socket->getMock();
+
+        $socketFactory = m::mock(SocketFactory::class)
+            ->shouldReceive('createClient')
+            ->andReturn($socket)
+            ->once()
+            ->getMock();
+
+        $promptMatcher = new PromptMatcher();
+
+        $interpretAsCommand = m::mock(InterpretAsCommand::class)
+            ->shouldReceive('interpret')
+            ->andReturn(false)
+            ->getMock();
+
+        $client = new TelnetClient($socketFactory, $promptMatcher, $interpretAsCommand);
+        $client->connect('dsn');
+        $client->setMaxBytesRead(20);
+
+        $client->execute('aCommand');
+    }
+
     public function testFactory()
     {
         $client = TelnetClient::factory();