lg_update_blocker/app/index.js

/**
 * LG Update Blocker - frontend.
 *
 * No frameworks and no build step: Luna calls go straight through
 * PalmServiceBridge, which every webOS webapp gets injected for free.
 */
(function () {
  'use strict';

  var SERVICE = 'luna://__SERVICE_ID__';
  var HBCHANNEL = 'luna://org.webosbrew.hbchannel.service';
  var HBCHANNEL_ELEVATE =
    '/media/developer/apps/usr/palm/services/org.webosbrew.hbchannel.service/elevate-service';

  var TOGGLES = [
    {
      key: 'blockHosts',
      title: 'Block LG update servers',
      desc: 'Points snu/su/nsu.lge.com at 127.0.0.1 in /etc/hosts, re-applied on every boot'
    },
    {
      key: 'dismissPopup',
      title: 'Close the update popup',
      desc: 'The TV asks LG about updates ~20s before homebrew starts, so the popup is closed instead'
    },
    {
      key: 'purgeCache',
      title: 'Delete staged firmware',
      desc: 'Wipes an already downloaded update - the usual reason the popup keeps returning'
    },
    {
      key: 'lockCache',
      title: 'Lock the staging folder',
      desc: 'Mounts an empty read-only folder over it so no update can be staged again'
    },
    {
      key: 'disableSettings',
      title: 'Turn off auto-update settings',
      desc: 'Switches off every update-related key com.webos.settingsservice exposes'
    }
  ];

  var ACTIONS = [
    { key: 'apply', label: 'Apply protection', primary: true },
    { key: 'purge', label: 'Purge staged update' },
    { key: 'revert', label: 'Remove protection' },
    { key: 'refresh', label: 'Refresh status' },
    { key: 'diagnostics', label: 'Diagnostics' }
  ];

  var config = {
    blockHosts: true,
    dismissPopup: true,
    purgeCache: true,
    lockCache: false,
    disableSettings: true
  };

  var focusables = [];
  var focusIndex = 0;
  var busy = false;
  var bridges = [];

  /* ----------------------------------------------------------- luna calls */

  function luna(uri, params, onSuccess, onFailure) {
    if (typeof PalmServiceBridge === 'undefined') {
      if (onFailure) onFailure({ returnValue: false, errorText: 'no Luna bus (not running on a TV)' });
      return;
    }
    var bridge = new PalmServiceBridge();
    bridges.push(bridge);
    bridge.onservicecallback = function (raw) {
      var index = bridges.indexOf(bridge);
      if (index !== -1) bridges.splice(index, 1);
      var response;
      try {
        response = JSON.parse(raw);
      } catch (err) {
        response = { returnValue: false, errorText: 'malformed response: ' + raw };
      }
      if (response.returnValue === false || response.errorText) {
        if (onFailure) onFailure(response);
      } else if (onSuccess) {
        onSuccess(response);
      }
    };
    bridge.call(uri, JSON.stringify(params || {}));
  }

  /* ------------------------------------------------------------------- ui */

  function el(id) {
    return document.getElementById(id);
  }

  function log(text) {
    var pane = el('log');
    var stamp = new Date().toTimeString().slice(0, 8);
    pane.textContent += '[' + stamp + '] ' + text + '\n';
    pane.scrollTop = pane.scrollHeight;
  }

  function logLines(lines) {
    (lines || []).forEach(function (line) {
      log(line);
    });
  }

  function setHint(text, isBusy) {
    var hint = el('hint');
    hint.textContent = text || '';
    hint.className = isBusy ? 'busy' : '';
  }

  function setBusy(state, text) {
    busy = state;
    setHint(text || (state ? 'working…' : ''), state);
  }

  function bytes(value) {
    if (!value) return '0 B';
    var units = ['B', 'kB', 'MB', 'GB'];
    var index = 0;
    var size = value;
    while (size >= 1024 && index < units.length - 1) {
      size /= 1024;
      index += 1;
    }
    return (index === 0 ? size : size.toFixed(1)) + ' ' + units[index];
  }

  function buildUi() {
    var toggles = el('toggles');
    TOGGLES.forEach(function (toggle) {
      var row = document.createElement('div');
      row.className = 'row';
      row.innerHTML =
        '<div class="text"><div class="title"></div><div class="desc"></div></div>' +
        '<div class="state"></div>';
      row.querySelector('.title').textContent = toggle.title;
      row.querySelector('.desc').textContent = toggle.desc;
      row.dataset.toggle = toggle.key;
      row.onActivate = function () {
        config[toggle.key] = !config[toggle.key];
        renderToggles();
        log((config[toggle.key] ? 'enabled: ' : 'disabled: ') + toggle.title +
          ' (press Apply protection to write it to the TV)');
      };
      toggles.appendChild(row);
      focusables.push(row);
    });

    var actions = el('actions');
    ACTIONS.forEach(function (action) {
      var button = document.createElement('div');
      button.className = 'button' + (action.primary ? ' primary' : '');
      button.textContent = action.label;
      button.onActivate = function () {
        runAction(action.key);
      };
      actions.appendChild(button);
      focusables.push(button);
    });

    renderToggles();
    renderFocus();
  }

  function renderToggles() {
    TOGGLES.forEach(function (toggle, index) {
      var row = focusables[index];
      var on = !!config[toggle.key];
      row.className = 'row' + (on ? ' on' : '') + (index === focusIndex ? ' focused' : '');
      row.querySelector('.state').textContent = on ? 'ON' : 'OFF';
    });
  }

  function renderFocus() {
    focusables.forEach(function (node, index) {
      var focused = index === focusIndex;
      if (focused) {
        if (node.className.indexOf('focused') === -1) node.className += ' focused';
        if (node.scrollIntoView) node.scrollIntoView(false);
      } else {
        node.className = node.className.replace(/\s*focused/g, '');
      }
    });
  }

  function move(delta) {
    focusIndex = (focusIndex + delta + focusables.length) % focusables.length;
    renderFocus();
  }

  function badge(id, text, kind) {
    var node = el(id);
    node.textContent = text;
    node.className = 'badge' + (kind ? ' badge-' + kind : '');
  }

  function renderStatus(status) {
    var list = el('status');
    list.innerHTML = '';

    function row(label, value) {
      var wrapper = document.createElement('div');
      var dt = document.createElement('dt');
      var dd = document.createElement('dd');
      dt.textContent = label;
      dd.textContent = value;
      wrapper.appendChild(dt);
      wrapper.appendChild(dd);
      list.appendChild(wrapper);
    }

    var staged = 0;
    var stagedDirs = 0;
    var locked = 0;
    (status.cache || []).forEach(function (entry) {
      stagedDirs += 1;
      staged += entry.bytes || 0;
      if (entry.locked) locked += 1;
    });

    row('Service user', status.root ? 'root' : 'uid ' + status.uid + ' (not elevated)');
    row('Hosts entries', status.hosts.blockedDomains + ' / ' + status.hosts.totalDomains +
      (status.hosts.bindMounted ? ' (bind-mounted)' : ''));
    row('Staging folders', stagedDirs ? stagedDirs + ' found' : 'none on this TV');
    row('Staged firmware', stagedDirs ? bytes(staged) : '-');
    row('Staging locked', stagedDirs ? locked + ' / ' + stagedDirs : '-');
    var popup = status.popup || {};
    row('Update popup this boot', popup.lastAlertId ? 'raised, then closed' : 'none raised');
    row('Popup watcher', popup.watcherPid ? 'running (pid ' + popup.watcherPid + ')' : 'not running');
    row('Boot hook', status.bootHook.installed ? 'installed' : 'not installed');

    var settings = status.settings || [];
    if (settings.length) {
      settings.forEach(function (entry) {
        row(entry.category + '/' + entry.key, JSON.stringify(entry.value));
      });
    } else {
      row('Update settings', 'none exposed');
    }

    badge('badge-root', status.root ? 'root' : 'no root', status.root ? 'ok' : 'bad');
    badge('badge-version', 'v' + status.version);

    if (status.config) {
      Object.keys(config).forEach(function (key) {
        if (typeof status.config[key] === 'boolean') config[key] = status.config[key];
      });
      renderToggles();
    }
  }

  /* -------------------------------------------------------------- actions */

  function refresh(onDone) {
    luna(SERVICE + '/status', {}, function (status) {
      renderStatus(status);
      if (onDone) onDone(status);
    }, function (err) {
      log('status failed: ' + (err.errorText || JSON.stringify(err)));
      badge('badge-root', 'service error', 'bad');
      if (onDone) onDone(null);
    });
  }

  function runAction(key) {
    if (busy) return;

    if (key === 'refresh') {
      setBusy(true, 'refreshing…');
      refresh(function () {
        setBusy(false);
        log('status refreshed');
      });
      return;
    }

    if (key === 'diagnostics') {
      setBusy(true, 'collecting diagnostics…');
      luna(SERVICE + '/diagnostics', {}, function (res) {
        setBusy(false);
        log('--- diagnostics ---');
        log('os: ' + JSON.stringify(res.osInfo));
        log('mounts: ' + JSON.stringify(res.mounts));
        log('settings: ' + JSON.stringify(res.settings));
        log('hosts (tail):\n' + res.hostsFile);
        log('boot hook log (tail):\n' + res.bootLog);
        log('--- end ---');
      }, function (err) {
        setBusy(false);
        log('diagnostics failed: ' + (err.errorText || JSON.stringify(err)));
      });
      return;
    }

    var uri = SERVICE + '/' + key;
    var params = key === 'apply' ? config : {};
    setBusy(true, key === 'revert' ? 'removing…' : 'applying…');
    luna(uri, params, function (res) {
      setBusy(false);
      logLines(res.log);
      if (res.status) renderStatus(res.status);
      else refresh();
    }, function (err) {
      setBusy(false);
      logLines(err.log);
      log('failed: ' + (err.errorText || JSON.stringify(err)));
    });
  }

  /* ------------------------------------------------------------ elevation */

  function elevate(onDone) {
    log('service is not running as root, asking the Homebrew Channel to elevate it…');

    function afterElevation() {
      // The running instance keeps its old (unprivileged) process; quitting it
      // makes the bus start a fresh, elevated one on the next call.
      luna(SERVICE + '/quit', {}, function () {
        window.setTimeout(recheck, 2500);
      }, function () {
        window.setTimeout(recheck, 2500);
      });
    }

    function recheck() {
      refresh(function (status) {
        if (status && status.root) {
          log('service elevated - ready');
        } else {
          log('still not elevated. Open the Homebrew Channel, make sure "Root status" says ' +
            '"ok", then relaunch this app.');
        }
        setBusy(false);
        if (onDone) onDone();
      });
    }

    luna(HBCHANNEL + '/elevateService', { id: '__SERVICE_ID__' }, function () {
      log('elevateService succeeded, restarting our service…');
      afterElevation();
    }, function (err) {
      log('elevateService unavailable (' + (err.errorText || 'unknown') + '), trying exec fallback…');
      luna(HBCHANNEL + '/exec', { command: HBCHANNEL_ELEVATE + ' __SERVICE_ID__' }, function () {
        log('elevate-service executed, restarting our service…');
        afterElevation();
      }, function (execErr) {
        log('could not elevate: ' + (execErr.errorText || JSON.stringify(execErr)));
        log('Is the Homebrew Channel installed and rooted? Its service must be elevated first.');
        setBusy(false);
        if (onDone) onDone();
      });
    });
  }

  /* ---------------------------------------------------------------- input */

  document.addEventListener('keydown', function (event) {
    switch (event.keyCode) {
      case 38: // up
        move(-1);
        break;
      case 40: // down
        move(1);
        break;
      case 37: // left
        move(-1);
        break;
      case 39: // right
        move(1);
        break;
      case 13: // OK
      case 32: // space (keyboard/dev)
        if (!busy && focusables[focusIndex] && focusables[focusIndex].onActivate) {
          focusables[focusIndex].onActivate();
        }
        break;
      case 461: // back
      case 27: // esc
        window.close();
        break;
      default:
        return;
    }
    event.preventDefault();
  });

  /* ----------------------------------------------------------------- boot */

  buildUi();
  log('LG Update Blocker v__VERSION__');
  setBusy(true, 'checking service…');
  refresh(function (status) {
    if (!status) {
      setBusy(false);
      return;
    }
    if (status.root) {
      setBusy(false);
      log('service is running as root - ready');
    } else {
      elevate();
    }
  });
})();