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