src/Model/GServer.php

   1 <?php
   2
   3 /**
   4  * @file src/Model/GServer.php
   5  * This file includes the GServer class to handle with servers
   6  */
   7 namespace Friendica\Model;
   8
   9 use DOMDocument;
  10 use DOMXPath;
  11 use Friendica\Core\Config;
  12 use Friendica\Core\Protocol;
  13 use Friendica\Core\Worker;
  14 use Friendica\Database\DBA;
  15 use Friendica\DI;
  16 use Friendica\Module\Register;
  17 use Friendica\Network\CurlResult;
  18 use Friendica\Util\Network;
  19 use Friendica\Util\DateTimeFormat;
  20 use Friendica\Util\Strings;
  21 use Friendica\Util\XML;
  22 use Friendica\Core\Logger;
  23 use Friendica\Protocol\PortableContact;
  24 use Friendica\Protocol\Diaspora;
  25 use Friendica\Network\Probe;
  26
  27 /**
  28  * This class handles GServer related functions
  29  */
  30 class GServer
  31 {
  32         // Directory types
  33         const DT_NONE = 0;
  34         const DT_POCO = 1;
  35         const DT_MASTODON = 2;
  36         /**
  37          * Checks if the given server is reachable
  38          *
  39          * @param string  $profile URL of the given profile
  40          * @param string  $server  URL of the given server (If empty, taken from profile)
  41          * @param string  $network Network value that is used, when detection failed
  42          * @param boolean $force   Force an update.
  43          *
  44          * @return boolean 'true' if server seems vital
  45          */
  46         public static function reachable(string $profile, string $server = '', string $network = '', bool $force = false)
  47         {
  48                 if ($server == '') {
  49                         $server = GContact::getBasepath($profile);
  50                 }
  51
  52                 if ($server == '') {
  53                         return true;
  54                 }
  55
  56                 return self::check($server, $network, $force);
  57         }
  58
  59         /**
  60          * Decides if a server needs to be updated, based upon several date fields
  61          *
  62          * @param date $created      Creation date of that server entry
  63          * @param date $updated      When had the server entry be updated
  64          * @param date $last_failure Last failure when contacting that server
  65          * @param date $last_contact Last time the server had been contacted
  66          *
  67          * @return boolean Does the server record needs an update?
  68          */
  69         public static function updateNeeded($created, $updated, $last_failure, $last_contact)
  70         {
  71                 $now = strtotime(DateTimeFormat::utcNow());
  72
  73                 if ($updated > $last_contact) {
  74                         $contact_time = strtotime($updated);
  75                 } else {
  76                         $contact_time = strtotime($last_contact);
  77                 }
  78
  79                 $failure_time = strtotime($last_failure);
  80                 $created_time = strtotime($created);
  81
  82                 // If there is no "created" time then use the current time
  83                 if ($created_time <= 0) {
  84                         $created_time = $now;
  85                 }
  86
  87                 // If the last contact was less than 24 hours then don't update
  88                 if (($now - $contact_time) < (60 * 60 * 24)) {
  89                         return false;
  90                 }
  91
  92                 // If the last failure was less than 24 hours then don't update
  93                 if (($now - $failure_time) < (60 * 60 * 24)) {
  94                         return false;
  95                 }
  96
  97                 // If the last contact was less than a week ago and the last failure is older than a week then don't update
  98                 //if ((($now - $contact_time) < (60 * 60 * 24 * 7)) && ($contact_time > $failure_time))
  99                 //      return false;
 100
 101                 // If the last contact time was more than a week ago and the contact was created more than a week ago, then only try once a week
 102                 if ((($now - $contact_time) > (60 * 60 * 24 * 7)) && (($now - $created_time) > (60 * 60 * 24 * 7)) && (($now - $failure_time) < (60 * 60 * 24 * 7))) {
 103                         return false;
 104                 }
 105
 106                 // If the last contact time was more than a month ago and the contact was created more than a month ago, then only try once a month
 107                 if ((($now - $contact_time) > (60 * 60 * 24 * 30)) && (($now - $created_time) > (60 * 60 * 24 * 30)) && (($now - $failure_time) < (60 * 60 * 24 * 30))) {
 108                         return false;
 109                 }
 110
 111                 return true;
 112         }
 113
 114         /**
 115          * Checks the state of the given server.
 116          *
 117          * @param string  $server_url URL of the given server
 118          * @param string  $network    Network value that is used, when detection failed
 119          * @param boolean $force      Force an update.
 120          *
 121          * @return boolean 'true' if server seems vital
 122          */
 123         public static function check(string $server_url, string $network = '', bool $force = false)
 124         {
 125                 // Unify the server address
 126                 $server_url = trim($server_url, '/');
 127                 $server_url = str_replace('/index.php', '', $server_url);
 128
 129                 if ($server_url == '') {
 130                         return false;
 131                 }
 132
 133                 $gserver = DBA::selectFirst('gserver', [], ['nurl' => Strings::normaliseLink($server_url)]);
 134                 if (DBA::isResult($gserver)) {
 135                         if ($gserver['created'] <= DBA::NULL_DATETIME) {
 136                                 $fields = ['created' => DateTimeFormat::utcNow()];
 137                                 $condition = ['nurl' => Strings::normaliseLink($server_url)];
 138                                 DBA::update('gserver', $fields, $condition);
 139                         }
 140
 141                         $last_contact = $gserver['last_contact'];
 142                         $last_failure = $gserver['last_failure'];
 143
 144                         // See discussion under https://forum.friendi.ca/display/0b6b25a8135aabc37a5a0f5684081633
 145                         // It can happen that a zero date is in the database, but storing it again is forbidden.
 146                         if ($last_contact < DBA::NULL_DATETIME) {
 147                                 $last_contact = DBA::NULL_DATETIME;
 148                         }
 149
 150                         if ($last_failure < DBA::NULL_DATETIME) {
 151                                 $last_failure = DBA::NULL_DATETIME;
 152                         }
 153
 154                         if (!$force && !self::updateNeeded($gserver['created'], '', $last_failure, $last_contact)) {
 155                                 Logger::info('No update needed', ['server' => $server_url]);
 156                                 return ($last_contact >= $last_failure);
 157                         }
 158                         Logger::info('Server is outdated. Start discovery.', ['Server' => $server_url, 'Force' => $force, 'Created' => $gserver['created'], 'Failure' => $last_failure, 'Contact' => $last_contact]);
 159                 } else {
 160                         Logger::info('Server is unknown. Start discovery.', ['Server' => $server_url]);
 161                 }
 162
 163                 return self::detect($server_url, $network);
 164         }
 165
 166         /**
 167          * Detect server data (type, protocol, version number, ...)
 168          * The detected data is then updated or inserted in the gserver table.
 169          *
 170          * @param string  $url     URL of the given server
 171          * @param string  $network Network value that is used, when detection failed
 172          *
 173          * @return boolean 'true' if server could be detected
 174          */
 175         public static function detect(string $url, string $network = '')
 176         {
 177                 Logger::info('Detect server type', ['server' => $url]);
 178                 $serverdata = [];
 179
 180                 $original_url = $url;
 181
 182                 // Remove URL content that is not supposed to exist for a server url
 183                 $urlparts = parse_url($url);
 184                 unset($urlparts['user']);
 185                 unset($urlparts['pass']);
 186                 unset($urlparts['query']);
 187                 unset($urlparts['fragment']);
 188                 $url = Network::unparseURL($urlparts);
 189
 190                 // If the URL missmatches, then we mark the old entry as failure
 191                 if ($url != $original_url) {
 192                         DBA::update('gserver', ['last_failure' => DateTimeFormat::utcNow()], ['nurl' => Strings::normaliseLink($original_url)]);
 193                 }
 194
 195                 // When a nodeinfo is present, we don't need to dig further
 196                 $xrd_timeout = DI::config()->get('system', 'xrd_timeout');
 197                 $curlResult = Network::curl($url . '/.well-known/nodeinfo', false, ['timeout' => $xrd_timeout]);
 198                 if ($curlResult->isTimeout()) {
 199                         DBA::update('gserver', ['last_failure' => DateTimeFormat::utcNow()], ['nurl' => Strings::normaliseLink($url)]);
 200                         return false;
 201                 }
 202
 203                 $nodeinfo = self::fetchNodeinfo($url, $curlResult);
 204
 205                 // When nodeinfo isn't present, we use the older 'statistics.json' endpoint
 206                 if (empty($nodeinfo)) {
 207                         $nodeinfo = self::fetchStatistics($url);
 208                 }
 209
 210                 // If that didn't work out well, we use some protocol specific endpoints
 211                 // For Friendica and Zot based networks we have to dive deeper to reveal more details
 212                 if (empty($nodeinfo['network']) || in_array($nodeinfo['network'], [Protocol::DFRN, Protocol::ZOT])) {
 213                         // Fetch the landing page, possibly it reveals some data
 214                         if (empty($nodeinfo['network'])) {
 215                                 $curlResult = Network::curl($url, false, ['timeout' => $xrd_timeout]);
 216                                 if ($curlResult->isSuccess()) {
 217                                         $serverdata = self::analyseRootHeader($curlResult, $serverdata);
 218                                         $serverdata = self::analyseRootBody($curlResult, $serverdata, $url);
 219                                 }
 220
 221                                 if (!$curlResult->isSuccess() || empty($curlResult->getBody()) || self::invalidBody($curlResult->getBody())) {
 222                                         DBA::update('gserver', ['last_failure' => DateTimeFormat::utcNow()], ['nurl' => Strings::normaliseLink($url)]);
 223                                         return false;
 224                                 }
 225                         }
 226
 227                         if (empty($serverdata['network']) || ($serverdata['network'] == Protocol::ACTIVITYPUB)) {
 228                                 $serverdata = self::detectMastodonAlikes($url, $serverdata);
 229                         }
 230
 231                         // All following checks are done for systems that always have got a "host-meta" endpoint.
 232                         // With this check we don't have to waste time and ressources for dead systems.
 233                         // Also this hopefully prevents us from receiving abuse messages.
 234                         if (empty($serverdata['network']) && !self::validHostMeta($url)) {
 235                                 DBA::update('gserver', ['last_failure' => DateTimeFormat::utcNow()], ['nurl' => Strings::normaliseLink($url)]);
 236                                 return false;
 237                         }
 238
 239                         if (empty($serverdata['network']) || in_array($serverdata['network'], [Protocol::DFRN, Protocol::ACTIVITYPUB])) {
 240                                 $serverdata = self::detectFriendica($url, $serverdata);
 241                         }
 242
 243                         // the 'siteinfo.json' is some specific endpoint of Hubzilla and Red
 244                         if (empty($serverdata['network']) || ($serverdata['network'] == Protocol::ZOT)) {
 245                                 $serverdata = self::fetchSiteinfo($url, $serverdata);
 246                         }
 247
 248                         // The 'siteinfo.json' doesn't seem to be present on older Hubzilla installations
 249                         if (empty($serverdata['network'])) {
 250                                 $serverdata = self::detectHubzilla($url, $serverdata);
 251                         }
 252
 253                         if (empty($serverdata['network'])) {
 254                                 $serverdata = self::detectNextcloud($url, $serverdata);
 255                         }
 256
 257                         if (empty($serverdata['network'])) {
 258                                 $serverdata = self::detectGNUSocial($url, $serverdata);
 259                         }
 260                 } else {
 261                         $serverdata = $nodeinfo;
 262                 }
 263
 264                 // Detect the directory type
 265                 $serverdata['directory-type'] = self::DT_NONE;
 266                 $serverdata = self::checkPoCo($url, $serverdata);
 267                 $serverdata = self::checkMastodonDirectory($url, $serverdata);
 268
 269                 // We can't detect the network type. Possibly it is some system that we don't know yet
 270                 if (empty($serverdata['network'])) {
 271                         $serverdata['network'] = Protocol::PHANTOM;
 272                 }
 273
 274                 // When we hadn't been able to detect the network type, we use the hint from the parameter
 275                 if (($serverdata['network'] == Protocol::PHANTOM) && !empty($network)) {
 276                         $serverdata['network'] = $network;
 277                 }
 278
 279                 $serverdata['url'] = $url;
 280                 $serverdata['nurl'] = Strings::normaliseLink($url);
 281
 282                 // We take the highest number that we do find
 283                 $registeredUsers = $serverdata['registered-users'] ?? 0;
 284
 285                 // On an active server there has to be at least a single user
 286                 if (($serverdata['network'] != Protocol::PHANTOM) && ($registeredUsers == 0)) {
 287                         $registeredUsers = 1;
 288                 }
 289
 290                 if ($serverdata['network'] != Protocol::PHANTOM) {
 291                         $gcontacts = DBA::count('gcontact', ['server_url' => [$url, $serverdata['nurl']]]);
 292                         $apcontacts = DBA::count('apcontact', ['baseurl' => [$url, $serverdata['nurl']]]);
 293                         $contacts = DBA::count('contact', ['uid' => 0, 'baseurl' => [$url, $serverdata['nurl']]]);
 294                         $serverdata['registered-users'] = max($gcontacts, $apcontacts, $contacts, $registeredUsers);
 295                 } else {
 296                         $serverdata['registered-users'] = $registeredUsers;
 297                         $serverdata = self::detectNetworkViaContacts($url, $serverdata);
 298                 }
 299
 300                 $serverdata['last_contact'] = DateTimeFormat::utcNow();
 301
 302                 $gserver = DBA::selectFirst('gserver', ['network'], ['nurl' => Strings::normaliseLink($url)]);
 303                 if (!DBA::isResult($gserver)) {
 304                         $serverdata['created'] = DateTimeFormat::utcNow();
 305                         $ret = DBA::insert('gserver', $serverdata);
 306                 } else {
 307                         // Don't override the network with 'unknown' when there had been a valid entry before
 308                         if (($serverdata['network'] == Protocol::PHANTOM) && !empty($gserver['network'])) {
 309                                 unset($serverdata['network']);
 310                         }
 311
 312                         $ret = DBA::update('gserver', $serverdata, ['nurl' => $serverdata['nurl']]);
 313                 }
 314
 315                 if (!empty($serverdata['network']) && in_array($serverdata['network'], [Protocol::DFRN, Protocol::DIASPORA])) {
 316                         self::discoverRelay($url);
 317                 }
 318
 319                 return $ret;
 320         }
 321
 322         /**
 323          * Fetch relay data from a given server url
 324          *
 325          * @param string $server_url address of the server
 326          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 327          */
 328         private static function discoverRelay(string $server_url)
 329         {
 330                 Logger::info('Discover relay data', ['server' => $server_url]);
 331
 332                 $curlResult = Network::curl($server_url . '/.well-known/x-social-relay');
 333                 if (!$curlResult->isSuccess()) {
 334                         return;
 335                 }
 336
 337                 $data = json_decode($curlResult->getBody(), true);
 338                 if (!is_array($data)) {
 339                         return;
 340                 }
 341
 342                 $gserver = DBA::selectFirst('gserver', ['id', 'relay-subscribe', 'relay-scope'], ['nurl' => Strings::normaliseLink($server_url)]);
 343                 if (!DBA::isResult($gserver)) {
 344                         return;
 345                 }
 346
 347                 if (($gserver['relay-subscribe'] != $data['subscribe']) || ($gserver['relay-scope'] != $data['scope'])) {
 348                         $fields = ['relay-subscribe' => $data['subscribe'], 'relay-scope' => $data['scope']];
 349                         DBA::update('gserver', $fields, ['id' => $gserver['id']]);
 350                 }
 351
 352                 DBA::delete('gserver-tag', ['gserver-id' => $gserver['id']]);
 353
 354                 if ($data['scope'] == 'tags') {
 355                         // Avoid duplicates
 356                         $tags = [];
 357                         foreach ($data['tags'] as $tag) {
 358                                 $tag = mb_strtolower($tag);
 359                                 if (strlen($tag) < 100) {
 360                                         $tags[$tag] = $tag;
 361                                 }
 362                         }
 363
 364                         foreach ($tags as $tag) {
 365                                 DBA::insert('gserver-tag', ['gserver-id' => $gserver['id'], 'tag' => $tag], true);
 366                         }
 367                 }
 368
 369                 // Create or update the relay contact
 370                 $fields = [];
 371                 if (isset($data['protocols'])) {
 372                         if (isset($data['protocols']['diaspora'])) {
 373                                 $fields['network'] = Protocol::DIASPORA;
 374
 375                                 if (isset($data['protocols']['diaspora']['receive'])) {
 376                                         $fields['batch'] = $data['protocols']['diaspora']['receive'];
 377                                 } elseif (is_string($data['protocols']['diaspora'])) {
 378                                         $fields['batch'] = $data['protocols']['diaspora'];
 379                                 }
 380                         }
 381
 382                         if (isset($data['protocols']['dfrn'])) {
 383                                 $fields['network'] = Protocol::DFRN;
 384
 385                                 if (isset($data['protocols']['dfrn']['receive'])) {
 386                                         $fields['batch'] = $data['protocols']['dfrn']['receive'];
 387                                 } elseif (is_string($data['protocols']['dfrn'])) {
 388                                         $fields['batch'] = $data['protocols']['dfrn'];
 389                                 }
 390                         }
 391                 }
 392                 Diaspora::setRelayContact($server_url, $fields);
 393         }
 394
 395         /**
 396          * Fetch server data from '/statistics.json' on the given server
 397          *
 398          * @param string $url URL of the given server
 399          *
 400          * @return array server data
 401          */
 402         private static function fetchStatistics(string $url)
 403         {
 404                 $curlResult = Network::curl($url . '/statistics.json');
 405                 if (!$curlResult->isSuccess()) {
 406                         return [];
 407                 }
 408
 409                 $data = json_decode($curlResult->getBody(), true);
 410                 if (empty($data)) {
 411                         return [];
 412                 }
 413
 414                 $serverdata = [];
 415
 416                 if (!empty($data['version'])) {
 417                         $serverdata['version'] = $data['version'];
 418                         // Version numbers on statistics.json are presented with additional info, e.g.:
 419                         // 0.6.3.0-p1702cc1c, 0.6.99.0-p1b9ab160 or 3.4.3-2-1191.
 420                         $serverdata['version'] = preg_replace('=(.+)-(.{4,})=ism', '$1', $serverdata['version']);
 421                 }
 422
 423                 if (!empty($data['name'])) {
 424                         $serverdata['site_name'] = $data['name'];
 425                 }
 426
 427                 if (!empty($data['network'])) {
 428                         $serverdata['platform'] = strtolower($data['network']);
 429
 430                         if ($serverdata['platform'] == 'diaspora') {
 431                                 $serverdata['network'] = Protocol::DIASPORA;
 432                         } elseif ($serverdata['platform'] == 'friendica') {
 433                                 $serverdata['network'] = Protocol::DFRN;
 434                         } elseif ($serverdata['platform'] == 'hubzilla') {
 435                                 $serverdata['network'] = Protocol::ZOT;
 436                         } elseif ($serverdata['platform'] == 'redmatrix') {
 437                                 $serverdata['network'] = Protocol::ZOT;
 438                         }
 439                 }
 440
 441
 442                 if (!empty($data['registrations_open'])) {
 443                         $serverdata['register_policy'] = Register::OPEN;
 444                 } else {
 445                         $serverdata['register_policy'] = Register::CLOSED;
 446                 }
 447
 448                 return $serverdata;
 449         }
 450
 451         /**
 452          * Detect server type by using the nodeinfo data
 453          *
 454          * @param string     $url        address of the server
 455          * @param CurlResult $curlResult
 456          * @return array Server data
 457          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 458          */
 459         private static function fetchNodeinfo(string $url, CurlResult $curlResult)
 460         {
 461                 $nodeinfo = json_decode($curlResult->getBody(), true);
 462
 463                 if (!is_array($nodeinfo) || empty($nodeinfo['links'])) {
 464                         return [];
 465                 }
 466
 467                 $nodeinfo1_url = '';
 468                 $nodeinfo2_url = '';
 469
 470                 foreach ($nodeinfo['links'] as $link) {
 471                         if (!is_array($link) || empty($link['rel']) || empty($link['href'])) {
 472                                 Logger::info('Invalid nodeinfo format', ['url' => $url]);
 473                                 continue;
 474                         }
 475                         if ($link['rel'] == 'http://nodeinfo.diaspora.software/ns/schema/1.0') {
 476                                 $nodeinfo1_url = $link['href'];
 477                         } elseif ($link['rel'] == 'http://nodeinfo.diaspora.software/ns/schema/2.0') {
 478                                 $nodeinfo2_url = $link['href'];
 479                         }
 480                 }
 481
 482                 if ($nodeinfo1_url . $nodeinfo2_url == '') {
 483                         return [];
 484                 }
 485
 486                 $server = [];
 487
 488                 // When the nodeinfo url isn't on the same host, then there is obviously something wrong
 489                 if (!empty($nodeinfo2_url) && (parse_url($url, PHP_URL_HOST) == parse_url($nodeinfo2_url, PHP_URL_HOST))) {
 490                         $server = self::parseNodeinfo2($nodeinfo2_url);
 491                 }
 492
 493                 // When the nodeinfo url isn't on the same host, then there is obviously something wrong
 494                 if (empty($server) && !empty($nodeinfo1_url) && (parse_url($url, PHP_URL_HOST) == parse_url($nodeinfo1_url, PHP_URL_HOST))) {
 495                         $server = self::parseNodeinfo1($nodeinfo1_url);
 496                 }
 497
 498                 return $server;
 499         }
 500
 501         /**
 502          * Parses Nodeinfo 1
 503          *
 504          * @param string $nodeinfo_url address of the nodeinfo path
 505          * @return array Server data
 506          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 507          */
 508         private static function parseNodeinfo1(string $nodeinfo_url)
 509         {
 510                 $curlResult = Network::curl($nodeinfo_url);
 511
 512                 if (!$curlResult->isSuccess()) {
 513                         return [];
 514                 }
 515
 516                 $nodeinfo = json_decode($curlResult->getBody(), true);
 517
 518                 if (!is_array($nodeinfo)) {
 519                         return [];
 520                 }
 521
 522                 $server = [];
 523
 524                 $server['register_policy'] = Register::CLOSED;
 525
 526                 if (!empty($nodeinfo['openRegistrations'])) {
 527                         $server['register_policy'] = Register::OPEN;
 528                 }
 529
 530                 if (is_array($nodeinfo['software'])) {
 531                         if (!empty($nodeinfo['software']['name'])) {
 532                                 $server['platform'] = strtolower($nodeinfo['software']['name']);
 533                         }
 534
 535                         if (!empty($nodeinfo['software']['version'])) {
 536                                 $server['version'] = $nodeinfo['software']['version'];
 537                                 // Version numbers on Nodeinfo are presented with additional info, e.g.:
 538                                 // 0.6.3.0-p1702cc1c, 0.6.99.0-p1b9ab160 or 3.4.3-2-1191.
 539                                 $server['version'] = preg_replace('=(.+)-(.{4,})=ism', '$1', $server['version']);
 540                         }
 541                 }
 542
 543                 if (!empty($nodeinfo['metadata']['nodeName'])) {
 544                         $server['site_name'] = $nodeinfo['metadata']['nodeName'];
 545                 }
 546
 547                 if (!empty($nodeinfo['usage']['users']['total'])) {
 548                         $server['registered-users'] = $nodeinfo['usage']['users']['total'];
 549                 }
 550
 551                 if (!empty($nodeinfo['protocols']['inbound']) && is_array($nodeinfo['protocols']['inbound'])) {
 552                         $protocols = [];
 553                         foreach ($nodeinfo['protocols']['inbound'] as $protocol) {
 554                                 $protocols[$protocol] = true;
 555                         }
 556
 557                         if (!empty($protocols['friendica'])) {
 558                                 $server['network'] = Protocol::DFRN;
 559                         } elseif (!empty($protocols['activitypub'])) {
 560                                 $server['network'] = Protocol::ACTIVITYPUB;
 561                         } elseif (!empty($protocols['diaspora'])) {
 562                                 $server['network'] = Protocol::DIASPORA;
 563                         } elseif (!empty($protocols['ostatus'])) {
 564                                 $server['network'] = Protocol::OSTATUS;
 565                         } elseif (!empty($protocols['gnusocial'])) {
 566                                 $server['network'] = Protocol::OSTATUS;
 567                         } elseif (!empty($protocols['zot'])) {
 568                                 $server['network'] = Protocol::ZOT;
 569                         }
 570                 }
 571
 572                 if (empty($server)) {
 573                         return [];
 574                 }
 575
 576                 return $server;
 577         }
 578
 579         /**
 580          * Parses Nodeinfo 2
 581          *
 582          * @param string $nodeinfo_url address of the nodeinfo path
 583          * @return array Server data
 584          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 585          */
 586         private static function parseNodeinfo2(string $nodeinfo_url)
 587         {
 588                 $curlResult = Network::curl($nodeinfo_url);
 589                 if (!$curlResult->isSuccess()) {
 590                         return [];
 591                 }
 592
 593                 $nodeinfo = json_decode($curlResult->getBody(), true);
 594
 595                 if (!is_array($nodeinfo)) {
 596                         return [];
 597                 }
 598
 599                 $server = [];
 600
 601                 $server['register_policy'] = Register::CLOSED;
 602
 603                 if (!empty($nodeinfo['openRegistrations'])) {
 604                         $server['register_policy'] = Register::OPEN;
 605                 }
 606
 607                 if (is_array($nodeinfo['software'])) {
 608                         if (!empty($nodeinfo['software']['name'])) {
 609                                 $server['platform'] = strtolower($nodeinfo['software']['name']);
 610                         }
 611
 612                         if (!empty($nodeinfo['software']['version'])) {
 613                                 $server['version'] = $nodeinfo['software']['version'];
 614                                 // Version numbers on Nodeinfo are presented with additional info, e.g.:
 615                                 // 0.6.3.0-p1702cc1c, 0.6.99.0-p1b9ab160 or 3.4.3-2-1191.
 616                                 $server['version'] = preg_replace('=(.+)-(.{4,})=ism', '$1', $server['version']);
 617                         }
 618                 }
 619
 620                 if (!empty($nodeinfo['metadata']['nodeName'])) {
 621                         $server['site_name'] = $nodeinfo['metadata']['nodeName'];
 622                 }
 623
 624                 if (!empty($nodeinfo['usage']['users']['total'])) {
 625                         $server['registered-users'] = $nodeinfo['usage']['users']['total'];
 626                 }
 627
 628                 if (!empty($nodeinfo['protocols'])) {
 629                         $protocols = [];
 630                         foreach ($nodeinfo['protocols'] as $protocol) {
 631                                 $protocols[$protocol] = true;
 632                         }
 633
 634                         if (!empty($protocols['dfrn'])) {
 635                                 $server['network'] = Protocol::DFRN;
 636                         } elseif (!empty($protocols['activitypub'])) {
 637                                 $server['network'] = Protocol::ACTIVITYPUB;
 638                         } elseif (!empty($protocols['diaspora'])) {
 639                                 $server['network'] = Protocol::DIASPORA;
 640                         } elseif (!empty($protocols['ostatus'])) {
 641                                 $server['network'] = Protocol::OSTATUS;
 642                         } elseif (!empty($protocols['gnusocial'])) {
 643                                 $server['network'] = Protocol::OSTATUS;
 644                         } elseif (!empty($protocols['zot'])) {
 645                                 $server['network'] = Protocol::ZOT;
 646                         }
 647                 }
 648
 649                 if (empty($server)) {
 650                         return [];
 651                 }
 652
 653                 return $server;
 654         }
 655
 656         /**
 657          * Fetch server information from a 'siteinfo.json' file on the given server
 658          *
 659          * @param string $url        URL of the given server
 660          * @param array  $serverdata array with server data
 661          *
 662          * @return array server data
 663          */
 664         private static function fetchSiteinfo(string $url, array $serverdata)
 665         {
 666                 $curlResult = Network::curl($url . '/siteinfo.json');
 667                 if (!$curlResult->isSuccess()) {
 668                         return $serverdata;
 669                 }
 670
 671                 $data = json_decode($curlResult->getBody(), true);
 672                 if (empty($data)) {
 673                         return $serverdata;
 674                 }
 675
 676                 if (!empty($data['url'])) {
 677                         $serverdata['platform'] = strtolower($data['platform']);
 678                         $serverdata['version'] = $data['version'];
 679                 }
 680
 681                 if (!empty($data['plugins'])) {
 682                         if (in_array('pubcrawl', $data['plugins'])) {
 683                                 $serverdata['network'] = Protocol::ACTIVITYPUB;
 684                         } elseif (in_array('diaspora', $data['plugins'])) {
 685                                 $serverdata['network'] = Protocol::DIASPORA;
 686                         } elseif (in_array('gnusoc', $data['plugins'])) {
 687                                 $serverdata['network'] = Protocol::OSTATUS;
 688                         } else {
 689                                 $serverdata['network'] = Protocol::ZOT;
 690                         }
 691                 }
 692
 693                 if (!empty($data['site_name'])) {
 694                         $serverdata['site_name'] = $data['site_name'];
 695                 }
 696
 697                 if (!empty($data['channels_total'])) {
 698                         $serverdata['registered-users'] = $data['channels_total'];
 699                 }
 700
 701                 if (!empty($data['register_policy'])) {
 702                         switch ($data['register_policy']) {
 703                                 case 'REGISTER_OPEN':
 704                                         $serverdata['register_policy'] = Register::OPEN;
 705                                         break;
 706
 707                                 case 'REGISTER_APPROVE':
 708                                         $serverdata['register_policy'] = Register::APPROVE;
 709                                         break;
 710
 711                                 case 'REGISTER_CLOSED':
 712                                 default:
 713                                         $serverdata['register_policy'] = Register::CLOSED;
 714                                         break;
 715                         }
 716                 }
 717
 718                 return $serverdata;
 719         }
 720
 721         /**
 722          * Checks if the server contains a valid host meta file
 723          *
 724          * @param string $url URL of the given server
 725          *
 726          * @return boolean 'true' if the server seems to be vital
 727          */
 728         private static function validHostMeta(string $url)
 729         {
 730                 $xrd_timeout = DI::config()->get('system', 'xrd_timeout');
 731                 $curlResult = Network::curl($url . '/.well-known/host-meta', false, ['timeout' => $xrd_timeout]);
 732                 if (!$curlResult->isSuccess()) {
 733                         return false;
 734                 }
 735
 736                 $xrd = XML::parseString($curlResult->getBody(), false);
 737                 if (!is_object($xrd)) {
 738                         return false;
 739                 }
 740
 741                 $elements = XML::elementToArray($xrd);
 742                 if (empty($elements) || empty($elements['xrd']) || empty($elements['xrd']['link'])) {
 743                         return false;
 744                 }
 745
 746                 $valid = false;
 747                 foreach ($elements['xrd']['link'] as $link) {
 748                         // When there is more than a single "link" element, the array looks slightly different
 749                         if (!empty($link['@attributes'])) {
 750                                 $link = $link['@attributes'];
 751                         }
 752
 753                         if (empty($link['rel']) || empty($link['template'])) {
 754                                 continue;
 755                         }
 756
 757                         if ($link['rel'] == 'lrdd') {
 758                                 // When the webfinger host is the same like the system host, it should be ok.
 759                                 $valid = (parse_url($url, PHP_URL_HOST) == parse_url($link['template'], PHP_URL_HOST));
 760                         }
 761                 }
 762
 763                 return $valid;
 764         }
 765
 766         /**
 767          * Detect the network of the given server via their known contacts
 768          *
 769          * @param string $url        URL of the given server
 770          * @param array  $serverdata array with server data
 771          *
 772          * @return array server data
 773          */
 774         private static function detectNetworkViaContacts(string $url, array $serverdata)
 775         {
 776                 $contacts = [];
 777
 778                 $gcontacts = DBA::select('gcontact', ['url', 'nurl'], ['server_url' => [$url, $serverdata['nurl']]]);
 779                 while ($gcontact = DBA::fetch($gcontacts)) {
 780                         $contacts[$gcontact['nurl']] = $gcontact['url'];
 781                 }
 782                 DBA::close($gcontacts);
 783
 784                 $apcontacts = DBA::select('apcontact', ['url'], ['baseurl' => [$url, $serverdata['nurl']]]);
 785                 while ($gcontact = DBA::fetch($gcontacts)) {
 786                         $contacts[Strings::normaliseLink($apcontact['url'])] = $apcontact['url'];
 787                 }
 788                 DBA::close($apcontacts);
 789
 790                 $pcontacts = DBA::select('contact', ['url', 'nurl'], ['uid' => 0, 'baseurl' => [$url, $serverdata['nurl']]]);
 791                 while ($gcontact = DBA::fetch($gcontacts)) {
 792                         $contacts[$pcontact['nurl']] = $pcontact['url'];
 793                 }
 794                 DBA::close($pcontacts);
 795
 796                 if (empty($contacts)) {
 797                         return $serverdata;
 798                 }
 799
 800                 foreach ($contacts as $contact) {
 801                         $probed = Probe::uri($contact);
 802                         if (in_array($probed['network'], Protocol::FEDERATED)) {
 803                                 $serverdata['network'] = $probed['network'];
 804                                 break;
 805                         }
 806                 }
 807
 808                 $serverdata['registered-users'] = max($serverdata['registered-users'], count($contacts));
 809
 810                 return $serverdata;
 811         }
 812
 813         /**
 814          * Checks if the given server does have a '/poco' endpoint.
 815          * This is used for the 'PortableContact' functionality,
 816          * which is used by both Friendica and Hubzilla.
 817          *
 818          * @param string $url        URL of the given server
 819          * @param array  $serverdata array with server data
 820          *
 821          * @return array server data
 822          */
 823         private static function checkPoCo(string $url, array $serverdata)
 824         {
 825                 $serverdata['poco'] = '';
 826
 827                 $curlResult = Network::curl($url. '/poco');
 828                 if (!$curlResult->isSuccess()) {
 829                         return $serverdata;
 830                 }
 831
 832                 $data = json_decode($curlResult->getBody(), true);
 833                 if (empty($data)) {
 834                         return $serverdata;
 835                 }
 836
 837                 if (!empty($data['totalResults'])) {
 838                         $registeredUsers = $serverdata['registered-users'] ?? 0;
 839                         $serverdata['registered-users'] = max($data['totalResults'], $registeredUsers);
 840                         $serverdata['directory-type'] = self::DT_POCO;
 841                         $serverdata['poco'] = $url . '/poco';
 842                 }
 843
 844                 return $serverdata;
 845         }
 846
 847         /**
 848          * Checks if the given server does have a Mastodon style directory endpoint.
 849          *
 850          * @param string $url        URL of the given server
 851          * @param array  $serverdata array with server data
 852          *
 853          * @return array server data
 854          */
 855         public static function checkMastodonDirectory(string $url, array $serverdata)
 856         {
 857                 $curlResult = Network::curl($url . '/api/v1/directory?limit=1');
 858                 if (!$curlResult->isSuccess()) {
 859                         return $serverdata;
 860                 }
 861
 862                 $data = json_decode($curlResult->getBody(), true);
 863                 if (empty($data)) {
 864                         return $serverdata;
 865                 }
 866
 867                 if (count($data) == 1) {
 868                         $serverdata['directory-type'] = self::DT_MASTODON;
 869                 }
 870
 871                 return $serverdata;
 872         }
 873
 874         /**
 875          * Detects the version number of a given server when it was a NextCloud installation
 876          *
 877          * @param string $url        URL of the given server
 878          * @param array  $serverdata array with server data
 879          *
 880          * @return array server data
 881          */
 882         private static function detectNextcloud(string $url, array $serverdata)
 883         {
 884                 $curlResult = Network::curl($url . '/status.php');
 885
 886                 if (!$curlResult->isSuccess() || ($curlResult->getBody() == '')) {
 887                         return $serverdata;
 888                 }
 889
 890                 $data = json_decode($curlResult->getBody(), true);
 891                 if (empty($data)) {
 892                         return $serverdata;
 893                 }
 894
 895                 if (!empty($data['version'])) {
 896                         $serverdata['platform'] = 'nextcloud';
 897                         $serverdata['version'] = $data['version'];
 898                         $serverdata['network'] = Protocol::ACTIVITYPUB;
 899                 }
 900
 901                 return $serverdata;
 902         }
 903
 904         /**
 905          * Detects data from a given server url if it was a mastodon alike system
 906          *
 907          * @param string $url        URL of the given server
 908          * @param array  $serverdata array with server data
 909          *
 910          * @return array server data
 911          */
 912         private static function detectMastodonAlikes(string $url, array $serverdata)
 913         {
 914                 $curlResult = Network::curl($url . '/api/v1/instance');
 915
 916                 if (!$curlResult->isSuccess() || ($curlResult->getBody() == '')) {
 917                         return $serverdata;
 918                 }
 919
 920                 $data = json_decode($curlResult->getBody(), true);
 921                 if (empty($data)) {
 922                         return $serverdata;
 923                 }
 924
 925                 if (!empty($data['version'])) {
 926                         $serverdata['platform'] = 'mastodon';
 927                         $serverdata['version'] = $data['version'] ?? '';
 928                         $serverdata['network'] = Protocol::ACTIVITYPUB;
 929                 }
 930
 931                 if (!empty($data['title'])) {
 932                         $serverdata['site_name'] = $data['title'];
 933                 }
 934
 935                 if (!empty($data['title']) && empty($serverdata['platform']) && empty($serverdata['network'])) {
 936                         $serverdata['platform'] = 'mastodon';
 937                         $serverdata['network'] = Protocol::ACTIVITYPUB;
 938                 }
 939
 940                 if (!empty($data['description'])) {
 941                         $serverdata['info'] = trim($data['description']);
 942                 }
 943
 944                 if (!empty($data['stats']['user_count'])) {
 945                         $serverdata['registered-users'] = $data['stats']['user_count'];
 946                 }
 947
 948                 if (!empty($serverdata['version']) && preg_match('/.*?\(compatible;\s(.*)\s(.*)\)/ism', $serverdata['version'], $matches)) {
 949                         $serverdata['platform'] = strtolower($matches[1]);
 950                         $serverdata['version'] = $matches[2];
 951                 }
 952
 953                 if (!empty($serverdata['version']) && strstr(strtolower($serverdata['version']), 'pleroma')) {
 954                         $serverdata['platform'] = 'pleroma';
 955                         $serverdata['version'] = trim(str_ireplace('pleroma', '', $serverdata['version']));
 956                 }
 957
 958                 if (!empty($serverdata['platform']) && strstr($serverdata['platform'], 'pleroma')) {
 959                         $serverdata['version'] = trim(str_ireplace('pleroma', '', $serverdata['platform']));
 960                         $serverdata['platform'] = 'pleroma';
 961                 }
 962
 963                 return $serverdata;
 964         }
 965
 966         /**
 967          * Detects data from typical Hubzilla endpoints
 968          *
 969          * @param string $url        URL of the given server
 970          * @param array  $serverdata array with server data
 971          *
 972          * @return array server data
 973          */
 974         private static function detectHubzilla(string $url, array $serverdata)
 975         {
 976                 $curlResult = Network::curl($url . '/api/statusnet/config.json');
 977                 if (!$curlResult->isSuccess() || ($curlResult->getBody() == '')) {
 978                         return $serverdata;
 979                 }
 980
 981                 $data = json_decode($curlResult->getBody(), true);
 982                 if (empty($data)) {
 983                         return $serverdata;
 984                 }
 985
 986                 if (!empty($data['site']['name'])) {
 987                         $serverdata['site_name'] = $data['site']['name'];
 988                 }
 989
 990                 if (!empty($data['site']['platform'])) {
 991                         $serverdata['platform'] = strtolower($data['site']['platform']['PLATFORM_NAME']);
 992                         $serverdata['version'] = $data['site']['platform']['STD_VERSION'];
 993                         $serverdata['network'] = Protocol::ZOT;
 994                 }
 995
 996                 if (!empty($data['site']['hubzilla'])) {
 997                         $serverdata['platform'] = strtolower($data['site']['hubzilla']['PLATFORM_NAME']);
 998                         $serverdata['version'] = $data['site']['hubzilla']['RED_VERSION'];
 999                         $serverdata['network'] = Protocol::ZOT;
1000                 }
1001
1002                 if (!empty($data['site']['redmatrix'])) {
1003                         if (!empty($data['site']['redmatrix']['PLATFORM_NAME'])) {
1004                                 $serverdata['platform'] = strtolower($data['site']['redmatrix']['PLATFORM_NAME']);
1005                         } elseif (!empty($data['site']['redmatrix']['RED_PLATFORM'])) {
1006                                 $serverdata['platform'] = strtolower($data['site']['redmatrix']['RED_PLATFORM']);
1007                         }
1008
1009                         $serverdata['version'] = $data['site']['redmatrix']['RED_VERSION'];
1010                         $serverdata['network'] = Protocol::ZOT;
1011                 }
1012
1013                 $private = false;
1014                 $inviteonly = false;
1015                 $closed = false;
1016
1017                 if (!empty($data['site']['closed'])) {
1018                         $closed = self::toBoolean($data['site']['closed']);
1019                 }
1020
1021                 if (!empty($data['site']['private'])) {
1022                         $private = self::toBoolean($data['site']['private']);
1023                 }
1024
1025                 if (!empty($data['site']['inviteonly'])) {
1026                         $inviteonly = self::toBoolean($data['site']['inviteonly']);
1027                 }
1028
1029                 if (!$closed && !$private and $inviteonly) {
1030                         $register_policy = Register::APPROVE;
1031                 } elseif (!$closed && !$private) {
1032                         $register_policy = Register::OPEN;
1033                 } else {
1034                         $register_policy = Register::CLOSED;
1035                 }
1036
1037                 return $serverdata;
1038         }
1039
1040         /**
1041          * Converts input value to a boolean value
1042          *
1043          * @param string|integer $val
1044          *
1045          * @return boolean
1046          */
1047         private static function toBoolean($val)
1048         {
1049                 if (($val == 'true') || ($val == 1)) {
1050                         return true;
1051                 } elseif (($val == 'false') || ($val == 0)) {
1052                         return false;
1053                 }
1054
1055                 return $val;
1056         }
1057
1058         /**
1059          * Detect if the URL belongs to a GNU Social server
1060          *
1061          * @param string $url        URL of the given server
1062          * @param array  $serverdata array with server data
1063          *
1064          * @return array server data
1065          */
1066         private static function detectGNUSocial(string $url, array $serverdata)
1067         {
1068                 // Test for GNU Social
1069                 $curlResult = Network::curl($url . '/api/gnusocial/version.json');
1070                 if ($curlResult->isSuccess() && ($curlResult->getBody() != '{"error":"not implemented"}') &&
1071                         ($curlResult->getBody() != '') && (strlen($curlResult->getBody()) < 30)) {
1072                         $serverdata['platform'] = 'gnusocial';
1073                         // Remove junk that some GNU Social servers return
1074                         $serverdata['version'] = str_replace(chr(239) . chr(187) . chr(191), '', $curlResult->getBody());
1075                         $serverdata['version'] = str_replace(["\r", "\n", "\t"], '', $serverdata['version']);
1076                         $serverdata['version'] = trim($serverdata['version'], '"');
1077                         $serverdata['network'] = Protocol::OSTATUS;
1078                         return $serverdata;
1079                 }
1080
1081                 // Test for Statusnet
1082                 $curlResult = Network::curl($url . '/api/statusnet/version.json');
1083                 if ($curlResult->isSuccess() && ($curlResult->getBody() != '{"error":"not implemented"}') &&
1084                         ($curlResult->getBody() != '') && (strlen($curlResult->getBody()) < 30)) {
1085
1086                         // Remove junk that some GNU Social servers return
1087                         $serverdata['version'] = str_replace(chr(239).chr(187).chr(191), '', $curlResult->getBody());
1088                         $serverdata['version'] = str_replace(["\r", "\n", "\t"], '', $serverdata['version']);
1089                         $serverdata['version'] = trim($serverdata['version'], '"');
1090
1091                         if (!empty($serverdata['version']) && strtolower(substr($serverdata['version'], 0, 7)) == 'pleroma') {
1092                                 $serverdata['platform'] = 'pleroma';
1093                                 $serverdata['version'] = trim(str_ireplace('pleroma', '', $serverdata['version']));
1094                                 $serverdata['network'] = Protocol::ACTIVITYPUB;
1095                         } else {
1096                                 $serverdata['platform'] = 'statusnet';
1097                                 $serverdata['network'] = Protocol::OSTATUS;
1098                         }
1099                 }
1100
1101                 return $serverdata;
1102         }
1103
1104         /**
1105          * Detect if the URL belongs to a Friendica server
1106          *
1107          * @param string $url        URL of the given server
1108          * @param array  $serverdata array with server data
1109          *
1110          * @return array server data
1111          */
1112         private static function detectFriendica(string $url, array $serverdata)
1113         {
1114                 $curlResult = Network::curl($url . '/friendica/json');
1115                 if (!$curlResult->isSuccess()) {
1116                         $curlResult = Network::curl($url . '/friendika/json');
1117                 }
1118
1119                 if (!$curlResult->isSuccess()) {
1120                         return $serverdata;
1121                 }
1122
1123                 $data = json_decode($curlResult->getBody(), true);
1124                 if (empty($data) || empty($data['version'])) {
1125                         return $serverdata;
1126                 }
1127
1128                 $serverdata['network'] = Protocol::DFRN;
1129                 $serverdata['version'] = $data['version'];
1130
1131                 if (!empty($data['no_scrape_url'])) {
1132                         $serverdata['noscrape'] = $data['no_scrape_url'];
1133                 }
1134
1135                 if (!empty($data['site_name'])) {
1136                         $serverdata['site_name'] = $data['site_name'];
1137                 }
1138
1139                 if (!empty($data['info'])) {
1140                         $serverdata['info'] = trim($data['info']);
1141                 }
1142
1143                 $register_policy = ($data['register_policy'] ?? '') ?: 'REGISTER_CLOSED';
1144                 switch ($register_policy) {
1145                         case 'REGISTER_OPEN':
1146                                 $serverdata['register_policy'] = Register::OPEN;
1147                                 break;
1148
1149                         case 'REGISTER_APPROVE':
1150                                 $serverdata['register_policy'] = Register::APPROVE;
1151                                 break;
1152
1153                         case 'REGISTER_CLOSED':
1154                         case 'REGISTER_INVITATION':
1155                                 $serverdata['register_policy'] = Register::CLOSED;
1156                                 break;
1157                         default:
1158                                 Logger::info('Register policy is invalid', ['policy' => $register_policy, 'server' => $url]);
1159                                 $serverdata['register_policy'] = Register::CLOSED;
1160                                 break;
1161                 }
1162
1163                 $serverdata['platform'] = strtolower($data['platform'] ?? '');
1164
1165                 return $serverdata;
1166         }
1167
1168         /**
1169          * Analyses the landing page of a given server for hints about type and system of that server
1170          *
1171          * @param object $curlResult result of curl execution
1172          * @param array  $serverdata array with server data
1173          * @param string $url        Server URL
1174          *
1175          * @return array server data
1176          */
1177         private static function analyseRootBody($curlResult, array $serverdata, string $url)
1178         {
1179                 $doc = new DOMDocument();
1180                 @$doc->loadHTML($curlResult->getBody());
1181                 $xpath = new DOMXPath($doc);
1182
1183                 $title = trim(XML::getFirstNodeValue($xpath, '//head/title/text()'));
1184                 if (!empty($title)) {
1185                         $serverdata['site_name'] = $title;
1186                 }
1187
1188                 $list = $xpath->query('//meta[@name]');
1189
1190                 foreach ($list as $node) {
1191                         $attr = [];
1192                         if ($node->attributes->length) {
1193                                 foreach ($node->attributes as $attribute) {
1194                                         $value = trim($attribute->value);
1195                                         if (empty($value)) {
1196                                                 continue;
1197                                         }
1198
1199                                         $attr[$attribute->name] = $value;
1200                                 }
1201
1202                                 if (empty($attr['name']) || empty($attr['content'])) {
1203                                         continue;
1204                                 }
1205                         }
1206
1207                         if ($attr['name'] == 'description') {
1208                                 $serverdata['info'] = $attr['content'];
1209                         }
1210
1211                         if ($attr['name'] == 'application-name') {
1212                                 $serverdata['platform'] = strtolower($attr['content']);
1213                                 if (in_array($attr['content'], ['Misskey', 'Write.as'])) {
1214                                         $serverdata['network'] = Protocol::ACTIVITYPUB;
1215                                 }
1216                         }
1217                         if (($attr['name'] == 'generator') && (empty($serverdata['platform']) || (substr(strtolower($attr['content']), 0, 9) == 'wordpress'))) {
1218                                 $serverdata['platform'] = strtolower($attr['content']);
1219                                 $version_part = explode(' ', $attr['content']);
1220
1221                                 if (count($version_part) == 2) {
1222                                         if (in_array($version_part[0], ['WordPress'])) {
1223                                                 $serverdata['platform'] = strtolower($version_part[0]);
1224                                                 $serverdata['version'] = $version_part[1];
1225
1226                                                 // We still do need a reliable test if some AP plugin is activated
1227                                                 if (DBA::exists('apcontact', ['baseurl' => $url])) {
1228                                                         $serverdata['network'] = Protocol::ACTIVITYPUB;
1229                                                 } else {
1230                                                         $serverdata['network'] = Protocol::FEED;
1231                                                 }
1232                                         }
1233                                         if (in_array($version_part[0], ['Friendika', 'Friendica'])) {
1234                                                 $serverdata['platform'] = strtolower($version_part[0]);
1235                                                 $serverdata['version'] = $version_part[1];
1236                                                 $serverdata['network'] = Protocol::DFRN;
1237                                         }
1238                                 }
1239                         }
1240                 }
1241
1242                 $list = $xpath->query('//meta[@property]');
1243
1244                 foreach ($list as $node) {
1245                         $attr = [];
1246                         if ($node->attributes->length) {
1247                                 foreach ($node->attributes as $attribute) {
1248                                         $value = trim($attribute->value);
1249                                         if (empty($value)) {
1250                                                 continue;
1251                                         }
1252
1253                                         $attr[$attribute->name] = $value;
1254                                 }
1255
1256                                 if (empty($attr['property']) || empty($attr['content'])) {
1257                                         continue;
1258                                 }
1259                         }
1260
1261                         if ($attr['property'] == 'og:site_name') {
1262                                 $serverdata['site_name'] = $attr['content'];
1263                         }
1264
1265                         if ($attr['property'] == 'og:description') {
1266                                 $serverdata['info'] = $attr['content'];
1267                         }
1268
1269                         if ($attr['property'] == 'og:platform') {
1270                                 $serverdata['platform'] = strtolower($attr['content']);
1271
1272                                 if (in_array($attr['content'], ['PeerTube'])) {
1273                                         $serverdata['network'] = Protocol::ACTIVITYPUB;
1274                                 }
1275                         }
1276
1277                         if ($attr['property'] == 'generator') {
1278                                 $serverdata['platform'] = strtolower($attr['content']);
1279
1280                                 if (in_array($attr['content'], ['hubzilla'])) {
1281                                         // We later check which compatible protocol modules are loaded.
1282                                         $serverdata['network'] = Protocol::ZOT;
1283                                 }
1284                         }
1285                 }
1286
1287                 return $serverdata;
1288         }
1289
1290         /**
1291          * Analyses the header data of a given server for hints about type and system of that server
1292          *
1293          * @param object $curlResult result of curl execution
1294          * @param array  $serverdata array with server data
1295          *
1296          * @return array server data
1297          */
1298         private static function analyseRootHeader($curlResult, array $serverdata)
1299         {
1300                 if ($curlResult->getHeader('server') == 'Mastodon') {
1301                         $serverdata['platform'] = 'mastodon';
1302                         $serverdata['network'] = $network = Protocol::ACTIVITYPUB;
1303                 } elseif ($curlResult->inHeader('x-diaspora-version')) {
1304                         $serverdata['platform'] = 'diaspora';
1305                         $serverdata['network'] = $network = Protocol::DIASPORA;
1306                         $serverdata['version'] = $curlResult->getHeader('x-diaspora-version');
1307                 } elseif ($curlResult->inHeader('x-friendica-version')) {
1308                         $serverdata['platform'] = 'friendica';
1309                         $serverdata['network'] = $network = Protocol::DFRN;
1310                         $serverdata['version'] = $curlResult->getHeader('x-friendica-version');
1311                 }
1312                 return $serverdata;
1313         }
1314
1315         /**
1316          * Test if the body contains valid content
1317          *
1318          * @param string $body
1319          * @return boolean
1320          */
1321         private static function invalidBody(string $body)
1322         {
1323                 // Currently we only test for a HTML element.
1324                 // Possibly we enhance this in the future.
1325                 return !strpos($body, '>');
1326         }
1327
1328         /**
1329          * Update the user directory of a given gserver record
1330          *
1331          * @param array $gserver gserver record
1332          */
1333         public static function updateDirectory(array $gserver)
1334         {
1335                 /// @todo Add Mastodon API directory
1336
1337                 if (!empty($gserver['poco'])) {
1338                         PortableContact::discoverSingleServer($gserver['id']);
1339                 }
1340         }
1341
1342         /**
1343          * Update GServer entries
1344          */
1345         public static function discover()
1346         {
1347                 // Update the server list
1348                 self::discoverFederation();
1349
1350                 $no_of_queries = 5;
1351
1352                 $requery_days = intval(DI::config()->get('system', 'poco_requery_days'));
1353
1354                 if ($requery_days == 0) {
1355                         $requery_days = 7;
1356                 }
1357
1358                 $last_update = date('c', time() - (60 * 60 * 24 * $requery_days));
1359
1360                 $gservers = DBA::p("SELECT `id`, `url`, `nurl`, `network`, `poco`
1361                         FROM `gserver`
1362                         WHERE `last_contact` >= `last_failure`
1363                         AND `poco` != ''
1364                         AND `last_poco_query` < ?
1365                         ORDER BY RAND()", $last_update
1366                 );
1367
1368                 while ($gserver = DBA::fetch($gservers)) {
1369                         if (!GServer::check($gserver['url'], $gserver['network'])) {
1370                                 // The server is not reachable? Okay, then we will try it later
1371                                 $fields = ['last_poco_query' => DateTimeFormat::utcNow()];
1372                                 DBA::update('gserver', $fields, ['nurl' => $gserver['nurl']]);
1373                                 continue;
1374                         }
1375
1376                         Logger::info('Update directory', ['server' => $gserver['url'], 'id' => $gserver['id']]);
1377                         Worker::add(PRIORITY_LOW, 'UpdateServerDirectory', $gserver);
1378
1379                         if (--$no_of_queries == 0) {
1380                                 break;
1381                         }
1382                 }
1383
1384                 DBA::close($gservers);
1385         }
1386
1387         /**
1388          * Discover federated servers
1389          */
1390         private static function discoverFederation()
1391         {
1392                 $last = DI::config()->get('poco', 'last_federation_discovery');
1393
1394                 if ($last) {
1395                         $next = $last + (24 * 60 * 60);
1396
1397                         if ($next > time()) {
1398                                 return;
1399                         }
1400                 }
1401
1402                 // Discover federated servers
1403                 $curlResult = Network::fetchUrl("http://the-federation.info/pods.json");
1404
1405                 if (!empty($curlResult)) {
1406                         $servers = json_decode($curlResult, true);
1407
1408                         if (!empty($servers['pods'])) {
1409                                 foreach ($servers['pods'] as $server) {
1410                                         Worker::add(PRIORITY_LOW, 'UpdateGServer', 'https://' . $server['host']);
1411                                 }
1412                         }
1413                 }
1414
1415                 // Disvover Mastodon servers
1416                 $accesstoken = DI::config()->get('system', 'instances_social_key');
1417
1418                 if (!empty($accesstoken)) {
1419                         $api = 'https://instances.social/api/1.0/instances/list?count=0';
1420                         $header = ['Authorization: Bearer '.$accesstoken];
1421                         $curlResult = Network::curl($api, false, ['headers' => $header]);
1422
1423                         if ($curlResult->isSuccess()) {
1424                                 $servers = json_decode($curlResult->getBody(), true);
1425
1426                                 foreach ($servers['instances'] as $server) {
1427                                         $url = (is_null($server['https_score']) ? 'http' : 'https') . '://' . $server['name'];
1428                                         Worker::add(PRIORITY_LOW, 'UpdateGServer', $url);
1429                                 }
1430                         }
1431                 }
1432
1433                 DI::config()->set('poco', 'last_federation_discovery', time());
1434         }
1435 }