From 4d2b5a5b84fd8f1ff666633e4a730133bf4f3e9e Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Fri, 23 Feb 2024 17:02:48 +0100
Subject: [serversetup-bwlp-ipxe] Add implementation of GRUB menu builder

---
 .../inc/scriptbuildergrub.inc.php                  | 330 +++++++++++++++++++++
 1 file changed, 330 insertions(+)
 create mode 100644 modules-available/serversetup-bwlp-ipxe/inc/scriptbuildergrub.inc.php

diff --git a/modules-available/serversetup-bwlp-ipxe/inc/scriptbuildergrub.inc.php b/modules-available/serversetup-bwlp-ipxe/inc/scriptbuildergrub.inc.php
new file mode 100644
index 00000000..9dce5214
--- /dev/null
+++ b/modules-available/serversetup-bwlp-ipxe/inc/scriptbuildergrub.inc.php
@@ -0,0 +1,330 @@
+<?php
+
+class ScriptBuilderGrub extends ScriptBuilderBase
+{
+
+	/** @var bool */
+	private $confCodeEmited = false;
+
+	public function __construct(?string $platform = null, ?string $serverIp = null)
+	{
+		if (empty($platform)) {
+			$platform = Request::any('platform', null, 'string');
+			if ($platform === 'pc' || stripos($platform, 'bios') !== false) {
+				$platform = 'PCBIOS';
+			}
+		}
+		parent::__construct($platform, $serverIp, false);
+	}
+
+	private function getConfCode(): string
+	{
+		if ($this->confCodeEmited)
+			return '';
+		$this->confCodeEmited = true;
+		$str = '
+if ! [ "$uuid" ] ; then
+  smbios --type 1 --get-uuid 8 --set uuid
+fi
+set serverip="' . $this->getLocalIp() . '"
+';
+		foreach (['mac', 'ip', 'domain', 'hostname'] as $var) {
+			$str .= <<<EOF
+if ! [ "\$$var" ] ; then
+	set $var="\$net_default_$var"
+fi
+if ! [ "\$$var" ] ; then
+	set $var="\$net_efinet0_dhcp_$var"
+fi
+
+EOF;
+
+		}
+		return $str;
+	}
+
+	private function getLocalIp(): string
+	{
+		if (isset($_SERVER['SCRIPT_URI']) && preg_match('#^\w+://([^/]+)#', $_SERVER['SCRIPT_URI'], $out)) {
+			$host = $out[1];
+		} elseif (isset($_SERVER['SERVER_NAME'])) {
+			$host = $_SERVER['SERVER_NAME'];
+		} elseif (isset($_SERVER['SERVER_ADDR'])) {
+			$host = $_SERVER['SERVER_ADDR'];
+		} else {
+			$host = $this->serverIp;
+		}
+		return $host;
+	}
+
+	private function getGrubBase(): string
+	{
+		return '(http,' . $this->getLocalIp() . ')';
+	}
+
+	private function getUrlBase(): string
+	{
+		$host = $this->getGrubBase();
+		if (isset($_SERVER['REQUEST_URI'])) {
+			$url = parse_url($_SERVER['REQUEST_URI']);
+			$path = $url['path'];
+		} else {
+			// Static fallback
+			$path = '/boot/ipxe';
+		}
+		return $host . $path;
+
+	}
+
+	private function getUrlFull(?string $key = null, ?string $value = null): string
+	{
+		$url = parse_url($_SERVER['REQUEST_URI']);
+		$urlbase = $this->getUrlBase();
+		if (empty($url['query'])) {
+			$fromQuery = [];
+		} else {
+			parse_str($url['query'], $fromQuery);
+			foreach ($fromQuery as &$v) {
+				$v = urlencode($v);
+			}
+			unset($v);
+		}
+		unset($fromQuery['entryid'], $fromQuery['special'], $fromQuery['redir']);
+		if ($key !== null) {
+			$fromQuery[$key] = $value;
+		}
+		$required = [
+			'type' => 'grub',
+			'uuid' => '$uuid',
+			'mac' => '$mac',
+			'platform' => '$grub_platform',
+		];
+		$fullQuery = '?';
+		foreach ($required + $fromQuery as $k => $v) { // Loop instead of http_build_query since we don't want escaping for the varnames!
+			$fullQuery .= $k . '=' . $v . '&';
+		}
+		return $urlbase . $fullQuery;
+	}
+
+	/**
+	 * Redirect to same URL, but add our extended params
+	 */
+	private function redirect(string $key = null, string $value = null): string
+	{
+		// Redirect to self with added parameters
+		$urlfull = $this->getUrlFull($key, $value);
+		return $this->getConfCode() . <<<HERE
+
+set self="${urlfull}"
+echo "Chaining to \$self..."
+configfile \${self}redir=1
+
+HERE;
+	}
+
+	/**
+	 * Called when we handle a real client request, and don't just generate static data
+	 * for whatever use-case that might have. In the latter case, it wouldn't make much sense
+	 * to generate a redirect code snippet.
+	 *
+	 * @return string
+	 */
+	public function bootstrapLive()
+	{
+		// Check if required arguments are given; if not, spit out according script and chain to self
+		if ($this->uuid === null || $this->platform === '') {
+			// REQUIRED so we can hide incompatible entries
+			// but avoid redirect cycle
+			if (Request::any('redir', '', 'string') === '') {
+				return $this->redirect();
+			}
+		}
+		return false;
+	}
+
+	public function getBootEntry(?BootEntry $entry): string
+	{
+		if ($entry === null) {
+			return "echo Invalid boot entry id\nsleep --interruptible --verbose 10\n";
+		}
+		return $entry->toScript($this);
+	}
+
+	public function getMenu(IPxeMenu $menu, bool $bootstrap): string
+	{
+		$base = $this->getUrlFull();
+		return $this->getConfCode()
+			. "set self=\"{$base}\"\n"
+			. $this->menuToScript($menu);
+	}
+
+	public function menuToScript(IPxeMenu $menu): string
+	{
+		if ($menu->defaultEntryId === null) {
+			$output = <<<EOF
+set timeout=0
+
+EOF;
+
+		} else {
+			$secs = (int)($menu->timeoutMs / 1000);
+			$output = <<<EOF
+set timeout={$secs}
+set default="id-{$menu->defaultEntryId}"
+
+EOF;
+		}
+		$output .= $this->getConfCode();
+		foreach ($menu->items as $item) {
+			$output .= $this->getMenuItemScript($item);
+		}
+		return $output;
+	}
+
+	private function getMenuItemScript(MenuEntry $entry): string
+	{
+		$str = "menuentry '" . str_replace("'", '', $entry->title) . "' --id 'id-" . $entry->menuentryid . "' {\n";
+		if ($entry->gap) {
+			$str .= "true\n"; // AFAICT, not possible in GRUB
+		} elseif ($entry->bootEntry === null || (!empty($this->platform) && !$entry->bootEntry->supportsMode($this->platform))) {
+			$str .= "echo Type mismatch\n";
+		} elseif ($entry->hidden && $entry->hotkey === false) {
+			$str .= "echo Hidden entries without hotkey are illegal\n"; // Hidden entries without hotkey are illegal
+		} else {
+			if ($entry->hotkey !== false) {
+				// Not supported by grub...
+			}
+			if ($entry->bootEntry instanceof MenuBootEntry) {
+				// Link
+				$str .= "configfile \${self}entryid={$entry->menuentryid}\n";
+			} else {
+				// Embed directly
+				// TODO: Password. Use read etc.; might need hashsum.mod, in that case, don't embed entry directly but use configfile...
+				$str .= $this->getMenuEntry($entry, true);
+			}
+		}
+		return $str . "}\n";
+	}
+
+	public function getSpecial(string $special): string
+	{
+		if ($special === 'localboot') {
+			// Sync this with setup-scripts/grub_localboot occasionally...
+			$output = <<<'EOF'
+insmod chain
+if [ "$grub_platform" = "pc" ] ; then
+	chainloader (hd0)+1
+	chainloader (hd1)+1
+	chainloader (hd2)+1
+fi
+insmod fat
+insmod part_gpt
+echo "Scanning, first pass..."
+for efi in (*,gpt*)/efi/grub/grubx64.efi (*,gpt*)/efi/boot/bootx64.efi (*,gpt*)/efi/*/*/bootmgfw.efi (*,gpt*)/efi/*/*.efi \
+		(*,msdos*)/efi/grub/grubx64.efi (*,msdos*)/efi/boot/bootx64.efi (*,msdos*)/efi/*/*/bootmgfw.efi (*,msdos*)/efi/*/*.efi; do
+	regexp --set=1:efi_device '^\((.*)\)/' "${efi}"
+done
+
+echo "Scanning, second pass..."
+for efi in (*,gpt*)/efi/grub/grubx64.efi (*,gpt*)/efi/boot/bootx64.efi (*,gpt*)/efi/*/*/bootmgfw.efi (*,gpt*)/efi/*/*.efi \
+		(*,msdos*)/efi/grub/grubx64.efi (*,msdos*)/efi/boot/bootx64.efi (*,msdos*)/efi/*/*/bootmgfw.efi (*,msdos*)/efi/*/*.efi; do
+	if [ -e "${efi}" ]; then
+		#regexp --set=1:efi_device '^\((.*)\)/' "${efi}"
+		regexp --set=1:root '^(\(.*\))/' "${efi}"
+		regexp --set=1:efi_path '^\(.*\)(/.*)$' "${efi}"
+		echo " >> Found operating system! <<"
+		echo " Path: '${efi}' on '${root}'"
+		echo " Fallback '${efi_path}'"
+		chainloader "${efi}"
+		boot
+		echo " That failed..."
+	fi
+done
+
+echo "No EFI known OS found. Exiting."
+exit
+EOF;
+
+		} else {
+			$output = <<<EOF
+echo "Unknown special command: $special"
+sleep --interruptible --verbose 10
+EOF;
+		}
+		return $output;
+	}
+
+	public function output(string $string): void
+	{
+		Header('Content-Type: text/plain; charset=UTF-8');
+		echo $string;
+	}
+
+	public function getMenuEntry(?MenuEntry $entry, bool $honorPassword = true): string
+	{
+		if ($entry === null)
+			return "echo Invalid menu entry id\nsleep --interruptible --verbose 10\n";
+		// TODO: Check for password
+		if ($honorPassword && !empty($entry->md5pass)) {
+			return "echo TODO: Implement password check...\nsleep --interruptible --verbose 10\n";
+		}
+		$meid = $entry->menuEntryId();
+		$output = $this->getConfCode() . "set menuentryid=$meid\n";
+		// Output actual entry
+		$output .= str_replace('%fail%', 'fail', $entry->getBootEntryScript($this));
+		return $output;
+	}
+
+	public function execDataToScript(?ExecData $agnostic, ?ExecData $bios, ?ExecData $efi): string
+	{
+		if ($agnostic !== null)
+			return $this->execDataToScriptInternal($agnostic);
+
+		if ($efi !== null && $this->platform === BootEntry::EFI)
+			return $this->execDataToScriptInternal($efi);
+		// Unknown or not EFI, should be BIOS at this point
+		return $this->execDataToScriptInternal($bios ?? $efi ?? new ExecData());
+	}
+
+	private function execDataToScriptInternal(ExecData $entry): string
+	{
+		$entry->sanitize();
+		$base = $this->getGrubBase();
+		$script = '';
+		// Overriding dhcpOpts probably not possible/necessary
+		$initrds = [];
+		if (!empty($entry->initRd)) {
+			foreach ($entry->initRd as $initrd) {
+				if (empty($initrd))
+					continue;
+				$initrds[] = $this->combineUrl($base, $initrd);
+			}
+		}
+		$file = $this->combineUrl($base, $entry->executable);
+		$script .= "linux $file {$entry->commandLine} slx.ipxe.id=\${menuentryid}\n";
+		if (!empty($initrds)) {
+			$script .= "initrd " . implode(' ', $initrds) . "\n";
+		}
+		return $script;
+	}
+
+	private function combineUrl(string $base, string $path): string
+	{
+		$url = parse_url($path);
+		if (isset($url['host'])) {
+			$scheme = $url['scheme'] ?? 'http';
+			$host = $url['host'];
+			$base = "($scheme,$host)";
+			$path = $url['path'] ?? '/';
+			if (isset($url['query'])) {
+				$path .= '?' . $url['query'];
+			}
+		} else {
+			if ($path[0] !== '/') {
+				$path = '/' . $path;
+			}
+		}
+		return $base . $path;
+	}
+
+}
-- 
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