Merge pull request #40280 from nextcloud/backport/40233/stable26

[stable26] Detect aborted connection in OC\Files\View and stop writing data to the output buffer

2 files changed, 16 insertions, 4 deletions

diff --git a/lib/private/Files/View.php b/lib/private/Files/View.php
index 95ad46ec554..0cf5e24616a 100644
--- a/lib/private/Files/View.php
+++ b/lib/private/Files/View.php
@@ -55,6 +55,7 @@ use OC\User\User;
 use OCA\Files_Sharing\SharedMount;
 use OCP\Constants;
 use OCP\Files\Cache\ICacheEntry;
+use OCP\Files\ConnectionLostException;
 use OCP\Files\EmptyFileNameException;
 use OCP\Files\FileNameTooLongException;
 use OCP\Files\InvalidCharacterInPathException;
@@ -427,10 +428,11 @@ class View {
 		}
 		$handle = $this->fopen($path, 'rb');
 		if ($handle) {
-			$chunkSize = 524288; // 512 kB chunks
+			$chunkSize = 524288; // 512 kiB chunks
 			while (!feof($handle)) {
 				echo fread($handle, $chunkSize);
 				flush();
+				$this->checkConnectionStatus();
 			}
 			fclose($handle);
 			return $this->filesize($path);
@@ -483,6 +485,7 @@ class View {
 					}
 					echo fread($handle, $len);
 					flush();
+					$this->checkConnectionStatus();
 				}
 				return ftell($handle) - $from;
 			}
@@ -492,6 +495,14 @@ class View {
 		return false;
 	}
 
+
+	private function checkConnectionStatus(): void {
+		$connectionStatus = \connection_status();
+		if ($connectionStatus !== CONNECTION_NORMAL) {
+			throw new ConnectionLostException("Connection lost. Status: $connectionStatus");
+		}
+	}
+
 	/**
 	 * @param string $path
 	 * @return mixed
diff --git a/lib/private/legacy/OC_Files.php b/lib/private/legacy/OC_Files.php
index 5655139b24a..2fa0f6d1b77 100644
--- a/lib/private/legacy/OC_Files.php
+++ b/lib/private/legacy/OC_Files.php
@@ -230,14 +230,15 @@ class OC_Files {
 			OC::$server->getLogger()->logException($ex);
 			$l = \OC::$server->getL10N('lib');
 			\OC_Template::printErrorPage($l->t('Cannot download file'), $ex->getMessage(), 200);
+		} catch (\OCP\Files\ConnectionLostException $ex) {
+			self::unlockAllTheFiles($dir, $files, $getType, $view, $filename);
+			OC::$server->getLogger()->logException($ex, ['level' => \OCP\ILogger::DEBUG]);
+			\OC_Template::printErrorPage('Connection lost', $ex->getMessage(), 200);
 		} catch (\Exception $ex) {
 			self::unlockAllTheFiles($dir, $files, $getType, $view, $filename);
 			OC::$server->getLogger()->logException($ex);
 			$l = \OC::$server->getL10N('lib');
 			$hint = method_exists($ex, 'getHint') ? $ex->getHint() : '';
-			if ($event && $event->getErrorMessage() !== null) {
-				$hint .= ' ' . $event->getErrorMessage();
-			}
 			\OC_Template::printErrorPage($l->t('Cannot download file'), $hint, 200);
 		}
 	}