From 2903a586a5f19e546ed12841e0c7a170320fd82b Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Wed, 26 Feb 2020 18:05:14 +0100
Subject: [minilinux] Show warning if stage4 cannot be replicated

---
 modules-available/minilinux/inc/minilinux.inc.php  | 75 ++++++++++++++++++++++
 modules-available/minilinux/page.inc.php           |  3 +
 .../minilinux/templates/filelist.html              |  3 +
 3 files changed, 81 insertions(+)

diff --git a/modules-available/minilinux/inc/minilinux.inc.php b/modules-available/minilinux/inc/minilinux.inc.php
index 7fe2035a..e79884f9 100644
--- a/modules-available/minilinux/inc/minilinux.inc.php
+++ b/modules-available/minilinux/inc/minilinux.inc.php
@@ -243,7 +243,9 @@ class MiniLinux
 		if ($task !== false) {
 			// Callback for db column
 			TaskmanagerCallback::addCallback($task, 'mlGotLinux', $versionid);
+			self::checkStage4($data);
 		}
+		// Race - someone else wrote a taskid to DB, just call self again to get that one
 		if ($aff === 0)
 			return self::downloadVersion($versionid);
 		return $task;
@@ -377,4 +379,77 @@ class MiniLinux
 		}
 	}
 
+	/**
+	 * Check whether an optionally required stage4 is available.
+	 * Return true if there is no stage4, otherwise check filesystem,
+	 * or try to request from local dnbd3-server.
+	 * @param array $data decoded data column from minilinux_version
+	 * @param string[] $errors in array of error messages if not available
+	 * @return bool true if stage4 is available or none required
+	 */
+	public static function checkStage4($data, &$errors = false)
+	{
+		$errors = [];
+		$image = false;
+		$rid = 0;
+		foreach (['agnostic', 'efi', 'bios'] as $type) {
+			if (!isset($data[$type]) || !isset($data[$type]['commandLine']))
+				continue;
+			if (!preg_match('/\bslx\.stage4\.path=(\S+)/', $data[$type]['commandLine'], $out))
+				continue;
+			$image = $out[1];
+			if (preg_match('/\bslx\.stage4\.rid=(\d+)/', $data[$type]['commandLine'], $out)) {
+				$rid = $out[1];
+			}
+			break;
+		}
+		if ($image === false)
+			return true; // No stage4
+		if (file_exists(CONFIG_VMSTORE_DIR . '/' . $image))
+			return true; // Already exists locally
+		// Not found locally -- try to replicate
+		$sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
+		if ($sock === false) {
+			$errors[] = 'Error creatring socket to connect to dnbd3-server';
+			return false;
+		}
+		socket_set_option($sock, SOL_SOCKET, SO_SNDTIMEO, array('sec' => 1, 'usec' => 0));
+		socket_set_option($sock, SOL_SOCKET, SO_RCVTIMEO, array('sec' => 5, 'usec' => 0));
+		if (@socket_connect($sock, '127.0.0.1', 5003) === false) {
+			$errors[] = 'Could not connect to local dnbd3-server';
+			socket_close($sock);
+			return false;
+		}
+		// proto-version(16), image name\0, rid(16), flags(8)
+		$payload = pack('vA*xvC', 3, $image, $rid, 0);
+		// magic(16), cmd(16), payload-len(32), offset(64), handle(64)
+		$packet = pack('A*vVPP', 'sr', 2, strlen($payload), 0, 1234) . $payload;
+		if (!socket_send($sock, $packet, strlen($packet), 0)) {
+			$errors[] = 'Cannot send request to dnbd3-server';
+			socket_close($sock);
+			return false;
+		}
+		$len = socket_recv($sock, $reply, 16, MSG_WAITALL);
+		if ($len === 0) {
+			$errors[] = 'Local dnbd3-server cannot replicate required stage4 from master-server';
+			socket_close($sock);
+			return false;
+		}
+		if ($len !== 16) {
+			$errors[] = 'Incomplete reply received from local dnbd3-server. Stage4 might not replicate!';
+			socket_close($sock);
+			return false;
+		}
+		socket_close($sock);
+		// Try to decode header
+		$reply = unpack('A2magic/vcmd/Vsize/Phandle', $reply);
+		if ($reply['magic'] !== 'sr') {
+			$errors[] = 'Reply has wrong magic';
+		}
+		if ($reply['cmd'] !== 2) {
+			$errors[] = 'Reply is not CMD_IMAGE_REPLY';
+		}
+		return empty($errors);
+	}
+
 }
\ No newline at end of file
diff --git a/modules-available/minilinux/page.inc.php b/modules-available/minilinux/page.inc.php
index 76bcb95f..faea7599 100644
--- a/modules-available/minilinux/page.inc.php
+++ b/modules-available/minilinux/page.inc.php
@@ -163,6 +163,9 @@ class Page_MiniLinux extends Page
 				MiniLinux::setInstalledState($versionid, true);
 			}
 		}
+		if ($data['dltask'] !== false || $ver['installed']) {
+			MiniLinux::checkStage4($data, $data['s4_errors']);
+		}
 		echo Render::parse('filelist', $data);
 	}
 
diff --git a/modules-available/minilinux/templates/filelist.html b/modules-available/minilinux/templates/filelist.html
index b006fd1e..fdbef4ad 100644
--- a/modules-available/minilinux/templates/filelist.html
+++ b/modules-available/minilinux/templates/filelist.html
@@ -41,6 +41,9 @@
 	</tr>
 {{/files}}
 </table>
+{{#s4_errors}}
+<div class="alert alert-warning">{{lang_maybeMissingStage4}}: {{.}}</div>
+{{/s4_errors}}
 {{#dltask}}
 <div class="hidden" data-tm-id="{{dltask}}" data-tm-callback="dlTmCb"></div>
 <pre class="collapse" id="error-{{dltask}}"></pre>
-- 
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