feat(scale): auto-discover gateway on local network

- api/scale_discover.php: async TCP scan of whole /24 subnet on port 8765, confirms with WebSocket handshake, returns found ws:// URLs in ~1.5s - index.html: '🔍 Auto' button next to gateway URL field - app.js: discoverScaleGateway() — calls relay, fills URL field and auto-saves settings + reconnects on success
2026-04-15 20:56:54 +00:00
parent 099a6cc4e8
commit 55c5b34381
3 changed files with 186 additions and 2 deletions
@@ -0,0 +1,142 @@
+<?php
+/**
+ * EverShelf Scale Gateway — Auto-discovery
+ *
+ * Scans the server's local /24 subnet for any host responding on the gateway
+ * port (default 8765) and confirms it with a WebSocket handshake.
+ *
+ * Returns: {"found": ["ws://192.168.1.100:8765", ...]}
+ */
+
+header('Content-Type: application/json');
+header('Cache-Control: no-cache');
+
+$port = (int)($_GET['port'] ?? 8765);
+if ($port < 1 || $port > 65535) $port = 8765;
+
+// ── Determine server LAN IP ────────────────────────────────────────────────
+// SERVER_ADDR may be 127.0.0.1 when accessed via internal vhost — fall back
+// to a UDP trick (no actual packet sent) to find the default-route interface IP.
+function localLanIp(): string {
+    $sock = @socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
+    if ($sock) {
+        @socket_connect($sock, '8.8.8.8', 53);
+        @socket_getsockname($sock, $ip);
+        socket_close($sock);
+        if (isset($ip) && filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) return $ip;
+    }
+    // Fallback: parse /proc/net/route for default gateway interface then ip neigh
+    $ifaces = @net_get_interfaces();
+    if ($ifaces) {
+        foreach ($ifaces as $name => $info) {
+            if ($name === 'lo') continue;
+            foreach ($info['unicast'] ?? [] as $u) {
+                $ip = $u['address'] ?? '';
+                if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4 | FILTER_FLAG_NO_PRIV_RANGE)) continue;
+                if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) return $ip;
+            }
+        }
+    }
+    return '';
+}
+
+$serverIp = localLanIp();
+$parts = explode('.', $serverIp);
+if (count($parts) !== 4) {
+    echo json_encode(['error' => 'Cannot determine local subnet', 'server_ip' => $serverIp]);
+    exit;
+}
+$subnet = $parts[0] . '.' . $parts[1] . '.' . $parts[2] . '.';
+
+// ── Phase 1: Async TCP connect to all 254 hosts ────────────────────────────
+// Non-blocking stream_socket_client + stream_select to detect open ports quickly.
+// Total scan budget: 1.5 seconds.
+
+$candidates = [];
+for ($i = 1; $i <= 254; $i++) {
+    $ip = $subnet . $i;
+    $sock = @stream_socket_client(
+        "tcp://{$ip}:{$port}", $errno, $errstr, 0,
+        STREAM_CLIENT_ASYNC_CONNECT | STREAM_CLIENT_CONNECT
+    );
+    if ($sock !== false) {
+        stream_set_blocking($sock, false);
+        $candidates[$ip] = $sock;
+    }
+}
+
+$found_tcp = [];
+$deadline = microtime(true) + 1.5;
+
+while (!empty($candidates) && microtime(true) < $deadline) {
+    $write  = array_values($candidates);
+    $except = array_values($candidates);
+    $read   = null;
+    $usec   = (int)(max(0, $deadline - microtime(true)) * 1_000_000);
+    $n = @stream_select($read, $write, $except, 0, $usec);
+    if ($n === false || $n === 0) break;
+
+    // Sockets in $except = connection refused/error
+    $failed = [];
+    foreach ($except as $s) {
+        $ip = array_search($s, $candidates, true);
+        if ($ip !== false) $failed[$ip] = true;
+    }
+    // Sockets in $write = connection complete (may overlap with $except on error)
+    foreach ($write as $s) {
+        $ip = array_search($s, $candidates, true);
+        if ($ip === false) continue;
+        if (!isset($failed[$ip])) {
+            $found_tcp[] = $ip;
+        }
+        @fclose($s);
+        unset($candidates[$ip]);
+    }
+    // Close failed sockets too
+    foreach ($failed as $ip => $_) {
+        if (isset($candidates[$ip])) {
+            @fclose($candidates[$ip]);
+            unset($candidates[$ip]);
+        }
+    }
+}
+foreach ($candidates as $s) @fclose($s); // close remaining (timeout)
+
+// ── Phase 2: WebSocket handshake to confirm each TCP responder ─────────────
+$gateways = [];
+foreach ($found_tcp as $ip) {
+    $sock = @stream_socket_client("tcp://{$ip}:{$port}", $errno, $errstr, 2);
+    if (!$sock) continue;
+    stream_set_timeout($sock, 2);
+
+    $key = base64_encode(random_bytes(16));
+    fwrite($sock,
+        "GET / HTTP/1.1\r\n" .
+        "Host: {$ip}:{$port}\r\n" .
+        "Upgrade: websocket\r\n" .
+        "Connection: Upgrade\r\n" .
+        "Sec-WebSocket-Key: {$key}\r\n" .
+        "Sec-WebSocket-Version: 13\r\n" .
+        "\r\n"
+    );
+
+    $resp = '';
+    $dl = microtime(true) + 2;
+    while (microtime(true) < $dl && !feof($sock)) {
+        $line = fgets($sock, 256);
+        if ($line === false) break;
+        $resp .= $line;
+        if ($line === "\r\n") break;
+    }
+    fclose($sock);
+
+    if (str_contains($resp, '101')) {
+        $gateways[] = "ws://{$ip}:{$port}";
+    }
+}
+
+echo json_encode([
+    'found'  => $gateways,
+    'subnet' => rtrim($subnet, '.') . '.0/24',
+    'server_ip' => $serverIp,
+]);