src/network/serverpackethandler.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2015 nerzhul, Loic Blot <loic.blot@unix-experience.fr>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "chatmessage.h"
  21 #include "server.h"
  22 #include "log.h"
  23 #include "emerge.h"
  24 #include "mapblock.h"
  25 #include "modchannels.h"
  26 #include "nodedef.h"
  27 #include "remoteplayer.h"
  28 #include "rollback_interface.h"
  29 #include "scripting_server.h"
  30 #include "settings.h"
  31 #include "tool.h"
  32 #include "version.h"
  33 #include "network/connection.h"
  34 #include "network/networkprotocol.h"
  35 #include "network/serveropcodes.h"
  36 #include "server/player_sao.h"
  37 #include "server/serverinventorymgr.h"
  38 #include "util/auth.h"
  39 #include "util/base64.h"
  40 #include "util/pointedthing.h"
  41 #include "util/serialize.h"
  42 #include "util/srp.h"
  43
  44 void Server::handleCommand_Deprecated(NetworkPacket* pkt)
  45 {
  46         infostream << "Server: " << toServerCommandTable[pkt->getCommand()].name
  47                 << " not supported anymore" << std::endl;
  48 }
  49
  50 void Server::handleCommand_Init(NetworkPacket* pkt)
  51 {
  52
  53         if(pkt->getSize() < 1)
  54                 return;
  55
  56         session_t peer_id = pkt->getPeerId();
  57         RemoteClient *client = getClient(peer_id, CS_Created);
  58
  59         Address addr;
  60         std::string addr_s;
  61         try {
  62                 addr = m_con->GetPeerAddress(peer_id);
  63                 addr_s = addr.serializeString();
  64         } catch (con::PeerNotFoundException &e) {
  65                 /*
  66                  * no peer for this packet found
  67                  * most common reason is peer timeout, e.g. peer didn't
  68                  * respond for some time, your server was overloaded or
  69                  * things like that.
  70                  */
  71                 infostream << "Server::ProcessData(): Canceling: peer " << peer_id <<
  72                         " not found" << std::endl;
  73                 return;
  74         }
  75
  76         if (client->getState() > CS_Created) {
  77                 verbosestream << "Server: Ignoring multiple TOSERVER_INITs from " <<
  78                         addr_s << " (peer_id=" << peer_id << ")" << std::endl;
  79                 return;
  80         }
  81
  82         client->setCachedAddress(addr);
  83
  84         verbosestream << "Server: Got TOSERVER_INIT from " << addr_s <<
  85                 " (peer_id=" << peer_id << ")" << std::endl;
  86
  87         // Do not allow multiple players in simple singleplayer mode.
  88         // This isn't a perfect way to do it, but will suffice for now
  89         if (m_simple_singleplayer_mode && m_clients.getClientIDs().size() > 1) {
  90                 infostream << "Server: Not allowing another client (" << addr_s <<
  91                         ") to connect in simple singleplayer mode" << std::endl;
  92                 DenyAccess(peer_id, SERVER_ACCESSDENIED_SINGLEPLAYER);
  93                 return;
  94         }
  95
  96         // First byte after command is maximum supported
  97         // serialization version
  98         u8 client_max;
  99         u16 supp_compr_modes;
 100         u16 min_net_proto_version = 0;
 101         u16 max_net_proto_version;
 102         std::string playerName;
 103
 104         *pkt >> client_max >> supp_compr_modes >> min_net_proto_version
 105                         >> max_net_proto_version >> playerName;
 106
 107         u8 our_max = SER_FMT_VER_HIGHEST_READ;
 108         // Use the highest version supported by both
 109         u8 depl_serial_v = std::min(client_max, our_max);
 110         // If it's lower than the lowest supported, give up.
 111         if (depl_serial_v < SER_FMT_VER_LOWEST_READ)
 112                 depl_serial_v = SER_FMT_VER_INVALID;
 113
 114         if (depl_serial_v == SER_FMT_VER_INVALID) {
 115                 actionstream << "Server: A mismatched client tried to connect from " <<
 116                         addr_s << " ser_fmt_max=" << (int)client_max << std::endl;
 117                 DenyAccess(peer_id, SERVER_ACCESSDENIED_WRONG_VERSION);
 118                 return;
 119         }
 120
 121         client->setPendingSerializationVersion(depl_serial_v);
 122
 123         /*
 124                 Read and check network protocol version
 125         */
 126
 127         u16 net_proto_version = 0;
 128
 129         // Figure out a working version if it is possible at all
 130         if (max_net_proto_version >= SERVER_PROTOCOL_VERSION_MIN ||
 131                         min_net_proto_version <= SERVER_PROTOCOL_VERSION_MAX) {
 132                 // If maximum is larger than our maximum, go with our maximum
 133                 if (max_net_proto_version > SERVER_PROTOCOL_VERSION_MAX)
 134                         net_proto_version = SERVER_PROTOCOL_VERSION_MAX;
 135                 // Else go with client's maximum
 136                 else
 137                         net_proto_version = max_net_proto_version;
 138         }
 139
 140         verbosestream << "Server: " << addr_s << ": Protocol version: min: "
 141                         << min_net_proto_version << ", max: " << max_net_proto_version
 142                         << ", chosen: " << net_proto_version << std::endl;
 143
 144         client->net_proto_version = net_proto_version;
 145
 146         if ((g_settings->getBool("strict_protocol_version_checking") &&
 147                         net_proto_version != LATEST_PROTOCOL_VERSION) ||
 148                         net_proto_version < SERVER_PROTOCOL_VERSION_MIN ||
 149                         net_proto_version > SERVER_PROTOCOL_VERSION_MAX) {
 150                 actionstream << "Server: A mismatched client tried to connect from " <<
 151                         addr_s << " proto_max=" << (int)max_net_proto_version << std::endl;
 152                 DenyAccess(peer_id, SERVER_ACCESSDENIED_WRONG_VERSION);
 153                 return;
 154         }
 155
 156         /*
 157                 Validate player name
 158         */
 159         const char* playername = playerName.c_str();
 160
 161         size_t pns = playerName.size();
 162         if (pns == 0 || pns > PLAYERNAME_SIZE) {
 163                 actionstream << "Server: Player with " <<
 164                         ((pns > PLAYERNAME_SIZE) ? "a too long" : "an empty") <<
 165                         " name tried to connect from " << addr_s << std::endl;
 166                 DenyAccess(peer_id, SERVER_ACCESSDENIED_WRONG_NAME);
 167                 return;
 168         }
 169
 170         if (!string_allowed(playerName, PLAYERNAME_ALLOWED_CHARS)) {
 171                 actionstream << "Server: Player with an invalid name tried to connect "
 172                         "from " << addr_s << std::endl;
 173                 DenyAccess(peer_id, SERVER_ACCESSDENIED_WRONG_CHARS_IN_NAME);
 174                 return;
 175         }
 176
 177         RemotePlayer *player = m_env->getPlayer(playername);
 178
 179         // If player is already connected, cancel
 180         if (player && player->getPeerId() != PEER_ID_INEXISTENT) {
 181                 actionstream << "Server: Player with name \"" << playername <<
 182                         "\" tried to connect, but player with same name is already connected" << std::endl;
 183                 DenyAccess(peer_id, SERVER_ACCESSDENIED_ALREADY_CONNECTED);
 184                 return;
 185         }
 186
 187         m_clients.setPlayerName(peer_id, playername);
 188         //TODO (later) case insensitivity
 189
 190         std::string legacyPlayerNameCasing = playerName;
 191
 192         if (!isSingleplayer() && strcasecmp(playername, "singleplayer") == 0) {
 193                 actionstream << "Server: Player with the name \"singleplayer\" tried "
 194                         "to connect from " << addr_s << std::endl;
 195                 DenyAccess(peer_id, SERVER_ACCESSDENIED_WRONG_NAME);
 196                 return;
 197         }
 198
 199         {
 200                 std::string reason;
 201                 if (m_script->on_prejoinplayer(playername, addr_s, &reason)) {
 202                         actionstream << "Server: Player with the name \"" << playerName <<
 203                                 "\" tried to connect from " << addr_s <<
 204                                 " but it was disallowed for the following reason: " << reason <<
 205                                 std::endl;
 206                         DenyAccess(peer_id, SERVER_ACCESSDENIED_CUSTOM_STRING, reason);
 207                         return;
 208                 }
 209         }
 210
 211         infostream << "Server: New connection: \"" << playerName << "\" from " <<
 212                 addr_s << " (peer_id=" << peer_id << ")" << std::endl;
 213
 214         // Enforce user limit.
 215         // Don't enforce for users that have some admin right or mod permits it.
 216         if (m_clients.isUserLimitReached() &&
 217                         playername != g_settings->get("name") &&
 218                         !m_script->can_bypass_userlimit(playername, addr_s)) {
 219                 actionstream << "Server: " << playername << " tried to join from " <<
 220                         addr_s << ", but there are already max_users=" <<
 221                         g_settings->getU16("max_users") << " players." << std::endl;
 222                 DenyAccess(peer_id, SERVER_ACCESSDENIED_TOO_MANY_USERS);
 223                 return;
 224         }
 225
 226         /*
 227                 Compose auth methods for answer
 228         */
 229         std::string encpwd; // encrypted Password field for the user
 230         bool has_auth = m_script->getAuth(playername, &encpwd, NULL);
 231         u32 auth_mechs = 0;
 232
 233         client->chosen_mech = AUTH_MECHANISM_NONE;
 234
 235         if (has_auth) {
 236                 std::vector<std::string> pwd_components = str_split(encpwd, '#');
 237                 if (pwd_components.size() == 4) {
 238                         if (pwd_components[1] == "1") { // 1 means srp
 239                                 auth_mechs |= AUTH_MECHANISM_SRP;
 240                                 client->enc_pwd = encpwd;
 241                         } else {
 242                                 actionstream << "User " << playername << " tried to log in, "
 243                                         "but password field was invalid (unknown mechcode)." <<
 244                                         std::endl;
 245                                 DenyAccess(peer_id, SERVER_ACCESSDENIED_SERVER_FAIL);
 246                                 return;
 247                         }
 248                 } else if (base64_is_valid(encpwd)) {
 249                         auth_mechs |= AUTH_MECHANISM_LEGACY_PASSWORD;
 250                         client->enc_pwd = encpwd;
 251                 } else {
 252                         actionstream << "User " << playername << " tried to log in, but "
 253                                 "password field was invalid (invalid base64)." << std::endl;
 254                         DenyAccess(peer_id, SERVER_ACCESSDENIED_SERVER_FAIL);
 255                         return;
 256                 }
 257         } else {
 258                 std::string default_password = g_settings->get("default_password");
 259                 if (default_password.length() == 0) {
 260                         auth_mechs |= AUTH_MECHANISM_FIRST_SRP;
 261                 } else {
 262                         // Take care of default passwords.
 263                         client->enc_pwd = get_encoded_srp_verifier(playerName, default_password);
 264                         auth_mechs |= AUTH_MECHANISM_SRP;
 265                         // Allocate player in db, but only on successful login.
 266                         client->create_player_on_auth_success = true;
 267                 }
 268         }
 269
 270         /*
 271                 Answer with a TOCLIENT_HELLO
 272         */
 273
 274         verbosestream << "Sending TOCLIENT_HELLO with auth method field: "
 275                 << auth_mechs << std::endl;
 276
 277         NetworkPacket resp_pkt(TOCLIENT_HELLO,
 278                 1 + 4 + legacyPlayerNameCasing.size(), peer_id);
 279
 280         u16 depl_compress_mode = NETPROTO_COMPRESSION_NONE;
 281         resp_pkt << depl_serial_v << depl_compress_mode << net_proto_version
 282                 << auth_mechs << legacyPlayerNameCasing;
 283
 284         Send(&resp_pkt);
 285
 286         client->allowed_auth_mechs = auth_mechs;
 287         client->setDeployedCompressionMode(depl_compress_mode);
 288
 289         m_clients.event(peer_id, CSE_Hello);
 290 }
 291
 292 void Server::handleCommand_Init2(NetworkPacket* pkt)
 293 {
 294         session_t peer_id = pkt->getPeerId();
 295         verbosestream << "Server: Got TOSERVER_INIT2 from " << peer_id << std::endl;
 296
 297         m_clients.event(peer_id, CSE_GotInit2);
 298         u16 protocol_version = m_clients.getProtocolVersion(peer_id);
 299
 300         std::string lang;
 301         if (pkt->getSize() > 0)
 302                 *pkt >> lang;
 303
 304         /*
 305                 Send some initialization data
 306         */
 307
 308         infostream << "Server: Sending content to " << getPlayerName(peer_id) <<
 309                 std::endl;
 310
 311         // Send item definitions
 312         SendItemDef(peer_id, m_itemdef, protocol_version);
 313
 314         // Send node definitions
 315         SendNodeDef(peer_id, m_nodedef, protocol_version);
 316
 317         m_clients.event(peer_id, CSE_SetDefinitionsSent);
 318
 319         // Send media announcement
 320         sendMediaAnnouncement(peer_id, lang);
 321
 322         RemoteClient *client = getClient(peer_id, CS_InitDone);
 323
 324         // Keep client language for server translations
 325         client->setLangCode(lang);
 326
 327         // Send active objects
 328         {
 329                 PlayerSAO *sao = getPlayerSAO(peer_id);
 330                 if (sao)
 331                         SendActiveObjectRemoveAdd(client, sao);
 332         }
 333
 334         // Send detached inventories
 335         sendDetachedInventories(peer_id, false);
 336
 337         // Send player movement settings
 338         SendMovement(peer_id);
 339
 340         // Send time of day
 341         u16 time = m_env->getTimeOfDay();
 342         float time_speed = g_settings->getFloat("time_speed");
 343         SendTimeOfDay(peer_id, time, time_speed);
 344
 345         SendCSMRestrictionFlags(peer_id);
 346
 347         // Warnings about protocol version can be issued here
 348         if (client->net_proto_version < LATEST_PROTOCOL_VERSION) {
 349                 SendChatMessage(peer_id, ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
 350                         L"# Server: WARNING: YOUR CLIENT'S VERSION MAY NOT BE FULLY COMPATIBLE "
 351                         L"WITH THIS SERVER!"));
 352         }
 353 }
 354
 355 void Server::handleCommand_RequestMedia(NetworkPacket* pkt)
 356 {
 357         std::vector<std::string> tosend;
 358         u16 numfiles;
 359
 360         *pkt >> numfiles;
 361
 362         session_t peer_id = pkt->getPeerId();
 363         infostream << "Sending " << numfiles << " files to " <<
 364                 getPlayerName(peer_id) << std::endl;
 365         verbosestream << "TOSERVER_REQUEST_MEDIA: " << std::endl;
 366
 367         for (u16 i = 0; i < numfiles; i++) {
 368                 std::string name;
 369
 370                 *pkt >> name;
 371
 372                 tosend.push_back(name);
 373                 verbosestream << "TOSERVER_REQUEST_MEDIA: requested file "
 374                                 << name << std::endl;
 375         }
 376
 377         sendRequestedMedia(peer_id, tosend);
 378 }
 379
 380 void Server::handleCommand_ClientReady(NetworkPacket* pkt)
 381 {
 382         session_t peer_id = pkt->getPeerId();
 383
 384         PlayerSAO* playersao = StageTwoClientInit(peer_id);
 385
 386         if (playersao == NULL) {
 387                 errorstream << "TOSERVER_CLIENT_READY stage 2 client init failed "
 388                         "peer_id=" << peer_id << std::endl;
 389                 DisconnectPeer(peer_id);
 390                 return;
 391         }
 392
 393
 394         if (pkt->getSize() < 8) {
 395                 errorstream << "TOSERVER_CLIENT_READY client sent inconsistent data, "
 396                         "disconnecting peer_id: " << peer_id << std::endl;
 397                 DisconnectPeer(peer_id);
 398                 return;
 399         }
 400
 401         u8 major_ver, minor_ver, patch_ver, reserved;
 402         std::string full_ver;
 403         *pkt >> major_ver >> minor_ver >> patch_ver >> reserved >> full_ver;
 404
 405         m_clients.setClientVersion(peer_id, major_ver, minor_ver, patch_ver,
 406                 full_ver);
 407
 408         if (pkt->getRemainingBytes() >= 2)
 409                 *pkt >> playersao->getPlayer()->formspec_version;
 410
 411         const std::vector<std::string> &players = m_clients.getPlayerNames();
 412         NetworkPacket list_pkt(TOCLIENT_UPDATE_PLAYER_LIST, 0, peer_id);
 413         list_pkt << (u8) PLAYER_LIST_INIT << (u16) players.size();
 414         for (const std::string &player: players) {
 415                 list_pkt <<  player;
 416         }
 417         m_clients.send(peer_id, 0, &list_pkt, true);
 418
 419         NetworkPacket notice_pkt(TOCLIENT_UPDATE_PLAYER_LIST, 0, PEER_ID_INEXISTENT);
 420         // (u16) 1 + std::string represents a pseudo vector serialization representation
 421         notice_pkt << (u8) PLAYER_LIST_ADD << (u16) 1 << std::string(playersao->getPlayer()->getName());
 422         m_clients.sendToAll(&notice_pkt);
 423         m_clients.event(peer_id, CSE_SetClientReady);
 424
 425         s64 last_login;
 426         m_script->getAuth(playersao->getPlayer()->getName(), nullptr, nullptr, &last_login);
 427         m_script->on_joinplayer(playersao, last_login);
 428
 429         // Send shutdown timer if shutdown has been scheduled
 430         if (m_shutdown_state.isTimerRunning()) {
 431                 SendChatMessage(peer_id, m_shutdown_state.getShutdownTimerMessage());
 432         }
 433 }
 434
 435 void Server::handleCommand_GotBlocks(NetworkPacket* pkt)
 436 {
 437         if (pkt->getSize() < 1)
 438                 return;
 439
 440         /*
 441                 [0] u16 command
 442                 [2] u8 count
 443                 [3] v3s16 pos_0
 444                 [3+6] v3s16 pos_1
 445                 ...
 446         */
 447
 448         u8 count;
 449         *pkt >> count;
 450
 451         if ((s16)pkt->getSize() < 1 + (int)count * 6) {
 452                 throw con::InvalidIncomingDataException
 453                                 ("GOTBLOCKS length is too short");
 454         }
 455
 456         m_clients.lock();
 457         RemoteClient *client = m_clients.lockedGetClientNoEx(pkt->getPeerId());
 458
 459         for (u16 i = 0; i < count; i++) {
 460                 v3s16 p;
 461                 *pkt >> p;
 462                 client->GotBlock(p);
 463         }
 464         m_clients.unlock();
 465 }
 466
 467 void Server::process_PlayerPos(RemotePlayer *player, PlayerSAO *playersao,
 468         NetworkPacket *pkt)
 469 {
 470         if (pkt->getRemainingBytes() < 12 + 12 + 4 + 4 + 4 + 1 + 1)
 471                 return;
 472
 473         v3s32 ps, ss;
 474         s32 f32pitch, f32yaw;
 475         u8 f32fov;
 476
 477         *pkt >> ps;
 478         *pkt >> ss;
 479         *pkt >> f32pitch;
 480         *pkt >> f32yaw;
 481
 482         f32 pitch = (f32)f32pitch / 100.0f;
 483         f32 yaw = (f32)f32yaw / 100.0f;
 484         u32 keyPressed = 0;
 485
 486         // default behavior (in case an old client doesn't send these)
 487         f32 fov = 0;
 488         u8 wanted_range = 0;
 489
 490         *pkt >> keyPressed;
 491         *pkt >> f32fov;
 492         fov = (f32)f32fov / 80.0f;
 493         *pkt >> wanted_range;
 494
 495         v3f position((f32)ps.X / 100.0f, (f32)ps.Y / 100.0f, (f32)ps.Z / 100.0f);
 496         v3f speed((f32)ss.X / 100.0f, (f32)ss.Y / 100.0f, (f32)ss.Z / 100.0f);
 497
 498         pitch = modulo360f(pitch);
 499         yaw = wrapDegrees_0_360(yaw);
 500
 501         if (!playersao->isAttached()) {
 502                 // Only update player positions when moving freely
 503                 // to not interfere with attachment handling
 504                 playersao->setBasePosition(position);
 505                 player->setSpeed(speed);
 506         }
 507         playersao->setLookPitch(pitch);
 508         playersao->setPlayerYaw(yaw);
 509         playersao->setFov(fov);
 510         playersao->setWantedRange(wanted_range);
 511
 512         player->keyPressed = keyPressed;
 513         player->control.jump  = (keyPressed & (0x1 << 4));
 514         player->control.aux1  = (keyPressed & (0x1 << 5));
 515         player->control.sneak = (keyPressed & (0x1 << 6));
 516         player->control.dig   = (keyPressed & (0x1 << 7));
 517         player->control.place = (keyPressed & (0x1 << 8));
 518         player->control.zoom  = (keyPressed & (0x1 << 9));
 519
 520         if (playersao->checkMovementCheat()) {
 521                 // Call callbacks
 522                 m_script->on_cheat(playersao, "moved_too_fast");
 523                 SendMovePlayer(pkt->getPeerId());
 524         }
 525 }
 526
 527 void Server::handleCommand_PlayerPos(NetworkPacket* pkt)
 528 {
 529         session_t peer_id = pkt->getPeerId();
 530         RemotePlayer *player = m_env->getPlayer(peer_id);
 531         if (player == NULL) {
 532                 errorstream <<
 533                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 534                         peer_id << " disconnecting peer!" << std::endl;
 535                 DisconnectPeer(peer_id);
 536                 return;
 537         }
 538
 539         PlayerSAO *playersao = player->getPlayerSAO();
 540         if (playersao == NULL) {
 541                 errorstream <<
 542                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
 543                         peer_id << " disconnecting peer!" << std::endl;
 544                 DisconnectPeer(peer_id);
 545                 return;
 546         }
 547
 548         // If player is dead we don't care of this packet
 549         if (playersao->isDead()) {
 550                 verbosestream << "TOSERVER_PLAYERPOS: " << player->getName()
 551                                 << " is dead. Ignoring packet";
 552                 return;
 553         }
 554
 555         process_PlayerPos(player, playersao, pkt);
 556 }
 557
 558 void Server::handleCommand_DeletedBlocks(NetworkPacket* pkt)
 559 {
 560         if (pkt->getSize() < 1)
 561                 return;
 562
 563         /*
 564                 [0] u16 command
 565                 [2] u8 count
 566                 [3] v3s16 pos_0
 567                 [3+6] v3s16 pos_1
 568                 ...
 569         */
 570
 571         u8 count;
 572         *pkt >> count;
 573
 574         RemoteClient *client = getClient(pkt->getPeerId());
 575
 576         if ((s16)pkt->getSize() < 1 + (int)count * 6) {
 577                 throw con::InvalidIncomingDataException
 578                                 ("DELETEDBLOCKS length is too short");
 579         }
 580
 581         for (u16 i = 0; i < count; i++) {
 582                 v3s16 p;
 583                 *pkt >> p;
 584                 client->SetBlockNotSent(p);
 585         }
 586 }
 587
 588 void Server::handleCommand_InventoryAction(NetworkPacket* pkt)
 589 {
 590         session_t peer_id = pkt->getPeerId();
 591         RemotePlayer *player = m_env->getPlayer(peer_id);
 592
 593         if (player == NULL) {
 594                 errorstream <<
 595                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 596                         peer_id << " disconnecting peer!" << std::endl;
 597                 DisconnectPeer(peer_id);
 598                 return;
 599         }
 600
 601         PlayerSAO *playersao = player->getPlayerSAO();
 602         if (playersao == NULL) {
 603                 errorstream <<
 604                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
 605                         peer_id << " disconnecting peer!" << std::endl;
 606                 DisconnectPeer(peer_id);
 607                 return;
 608         }
 609
 610         // Strip command and create a stream
 611         std::string datastring(pkt->getString(0), pkt->getSize());
 612         verbosestream << "TOSERVER_INVENTORY_ACTION: data=" << datastring
 613                 << std::endl;
 614         std::istringstream is(datastring, std::ios_base::binary);
 615         // Create an action
 616         std::unique_ptr<InventoryAction> a(InventoryAction::deSerialize(is));
 617         if (!a) {
 618                 infostream << "TOSERVER_INVENTORY_ACTION: "
 619                                 << "InventoryAction::deSerialize() returned NULL"
 620                                 << std::endl;
 621                 return;
 622         }
 623
 624         // If something goes wrong, this player is to blame
 625         RollbackScopeActor rollback_scope(m_rollback,
 626                         std::string("player:")+player->getName());
 627
 628         /*
 629                 Note: Always set inventory not sent, to repair cases
 630                 where the client made a bad prediction.
 631         */
 632
 633         const bool player_has_interact = checkPriv(player->getName(), "interact");
 634
 635         auto check_inv_access = [player, player_has_interact, this] (
 636                         const InventoryLocation &loc) -> bool {
 637
 638                 // Players without interact may modify their own inventory
 639                 if (!player_has_interact && loc.type != InventoryLocation::PLAYER) {
 640                         infostream << "Cannot modify foreign inventory: "
 641                                         << "No interact privilege" << std::endl;
 642                         return false;
 643                 }
 644
 645                 switch (loc.type) {
 646                 case InventoryLocation::CURRENT_PLAYER:
 647                         // Only used internally on the client, never sent
 648                         return false;
 649                 case InventoryLocation::PLAYER:
 650                         // Allow access to own inventory in all cases
 651                         return loc.name == player->getName();
 652                 case InventoryLocation::NODEMETA:
 653                         {
 654                                 // Check for out-of-range interaction
 655                                 v3f node_pos   = intToFloat(loc.p, BS);
 656                                 v3f player_pos = player->getPlayerSAO()->getEyePosition();
 657                                 f32 d = player_pos.getDistanceFrom(node_pos);
 658                                 return checkInteractDistance(player, d, "inventory");
 659                         }
 660                 case InventoryLocation::DETACHED:
 661                         return getInventoryMgr()->checkDetachedInventoryAccess(loc, player->getName());
 662                 default:
 663                         return false;
 664                 }
 665         };
 666
 667         /*
 668                 Handle restrictions and special cases of the move action
 669         */
 670         if (a->getType() == IAction::Move) {
 671                 IMoveAction *ma = (IMoveAction*)a.get();
 672
 673                 ma->from_inv.applyCurrentPlayer(player->getName());
 674                 ma->to_inv.applyCurrentPlayer(player->getName());
 675
 676                 m_inventory_mgr->setInventoryModified(ma->from_inv);
 677                 if (ma->from_inv != ma->to_inv)
 678                         m_inventory_mgr->setInventoryModified(ma->to_inv);
 679
 680                 if (!check_inv_access(ma->from_inv) ||
 681                                 !check_inv_access(ma->to_inv))
 682                         return;
 683
 684                 /*
 685                         Disable moving items out of craftpreview
 686                 */
 687                 if (ma->from_list == "craftpreview") {
 688                         infostream << "Ignoring IMoveAction from "
 689                                         << (ma->from_inv.dump()) << ":" << ma->from_list
 690                                         << " to " << (ma->to_inv.dump()) << ":" << ma->to_list
 691                                         << " because src is " << ma->from_list << std::endl;
 692                         return;
 693                 }
 694
 695                 /*
 696                         Disable moving items into craftresult and craftpreview
 697                 */
 698                 if (ma->to_list == "craftpreview" || ma->to_list == "craftresult") {
 699                         infostream << "Ignoring IMoveAction from "
 700                                         << (ma->from_inv.dump()) << ":" << ma->from_list
 701                                         << " to " << (ma->to_inv.dump()) << ":" << ma->to_list
 702                                         << " because dst is " << ma->to_list << std::endl;
 703                         return;
 704                 }
 705         }
 706         /*
 707                 Handle restrictions and special cases of the drop action
 708         */
 709         else if (a->getType() == IAction::Drop) {
 710                 IDropAction *da = (IDropAction*)a.get();
 711
 712                 da->from_inv.applyCurrentPlayer(player->getName());
 713
 714                 m_inventory_mgr->setInventoryModified(da->from_inv);
 715
 716                 /*
 717                         Disable dropping items out of craftpreview
 718                 */
 719                 if (da->from_list == "craftpreview") {
 720                         infostream << "Ignoring IDropAction from "
 721                                         << (da->from_inv.dump()) << ":" << da->from_list
 722                                         << " because src is " << da->from_list << std::endl;
 723                         return;
 724                 }
 725
 726                 // Disallow dropping items if not allowed to interact
 727                 if (!player_has_interact || !check_inv_access(da->from_inv))
 728                         return;
 729
 730                 // Disallow dropping items if dead
 731                 if (playersao->isDead()) {
 732                         infostream << "Ignoring IDropAction from "
 733                                         << (da->from_inv.dump()) << ":" << da->from_list
 734                                         << " because player is dead." << std::endl;
 735                         return;
 736                 }
 737         }
 738         /*
 739                 Handle restrictions and special cases of the craft action
 740         */
 741         else if (a->getType() == IAction::Craft) {
 742                 ICraftAction *ca = (ICraftAction*)a.get();
 743
 744                 ca->craft_inv.applyCurrentPlayer(player->getName());
 745
 746                 m_inventory_mgr->setInventoryModified(ca->craft_inv);
 747
 748                 // Disallow crafting if not allowed to interact
 749                 if (!player_has_interact) {
 750                         infostream << "Cannot craft: "
 751                                         << "No interact privilege" << std::endl;
 752                         return;
 753                 }
 754
 755                 if (!check_inv_access(ca->craft_inv))
 756                         return;
 757         } else {
 758                 // Unknown action. Ignored.
 759                 return;
 760         }
 761
 762         // Do the action
 763         a->apply(m_inventory_mgr.get(), playersao, this);
 764 }
 765
 766 void Server::handleCommand_ChatMessage(NetworkPacket* pkt)
 767 {
 768         std::wstring message;
 769         *pkt >> message;
 770
 771         session_t peer_id = pkt->getPeerId();
 772         RemotePlayer *player = m_env->getPlayer(peer_id);
 773         if (player == NULL) {
 774                 errorstream <<
 775                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 776                         peer_id << " disconnecting peer!" << std::endl;
 777                 DisconnectPeer(peer_id);
 778                 return;
 779         }
 780
 781         std::string name = player->getName();
 782
 783         std::wstring answer_to_sender = handleChat(name, message, true, player);
 784         if (!answer_to_sender.empty()) {
 785                 // Send the answer to sender
 786                 SendChatMessage(peer_id, ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
 787                         answer_to_sender));
 788         }
 789 }
 790
 791 void Server::handleCommand_Damage(NetworkPacket* pkt)
 792 {
 793         u16 damage;
 794
 795         *pkt >> damage;
 796
 797         session_t peer_id = pkt->getPeerId();
 798         RemotePlayer *player = m_env->getPlayer(peer_id);
 799
 800         if (player == NULL) {
 801                 errorstream <<
 802                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 803                         peer_id << " disconnecting peer!" << std::endl;
 804                 DisconnectPeer(peer_id);
 805                 return;
 806         }
 807
 808         PlayerSAO *playersao = player->getPlayerSAO();
 809         if (playersao == NULL) {
 810                 errorstream <<
 811                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
 812                         peer_id << " disconnecting peer!" << std::endl;
 813                 DisconnectPeer(peer_id);
 814                 return;
 815         }
 816
 817         if (!playersao->isImmortal()) {
 818                 if (playersao->isDead()) {
 819                         verbosestream << "Server::ProcessData(): Info: "
 820                                 "Ignoring damage as player " << player->getName()
 821                                 << " is already dead." << std::endl;
 822                         return;
 823                 }
 824
 825                 actionstream << player->getName() << " damaged by "
 826                                 << (int)damage << " hp at " << PP(playersao->getBasePosition() / BS)
 827                                 << std::endl;
 828
 829                 PlayerHPChangeReason reason(PlayerHPChangeReason::FALL);
 830                 playersao->setHP((s32)playersao->getHP() - (s32)damage, reason);
 831         }
 832 }
 833
 834 void Server::handleCommand_PlayerItem(NetworkPacket* pkt)
 835 {
 836         if (pkt->getSize() < 2)
 837                 return;
 838
 839         session_t peer_id = pkt->getPeerId();
 840         RemotePlayer *player = m_env->getPlayer(peer_id);
 841
 842         if (player == NULL) {
 843                 errorstream <<
 844                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 845                         peer_id << " disconnecting peer!" << std::endl;
 846                 DisconnectPeer(peer_id);
 847                 return;
 848         }
 849
 850         PlayerSAO *playersao = player->getPlayerSAO();
 851         if (playersao == NULL) {
 852                 errorstream <<
 853                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
 854                         peer_id << " disconnecting peer!" << std::endl;
 855                 DisconnectPeer(peer_id);
 856                 return;
 857         }
 858
 859         u16 item;
 860
 861         *pkt >> item;
 862
 863         if (item >= player->getHotbarItemcount()) {
 864                 actionstream << "Player: " << player->getName()
 865                         << " tried to access item=" << item
 866                         << " out of hotbar_itemcount="
 867                         << player->getHotbarItemcount()
 868                         << "; ignoring." << std::endl;
 869                 return;
 870         }
 871
 872         playersao->getPlayer()->setWieldIndex(item);
 873 }
 874
 875 void Server::handleCommand_Respawn(NetworkPacket* pkt)
 876 {
 877         session_t peer_id = pkt->getPeerId();
 878         RemotePlayer *player = m_env->getPlayer(peer_id);
 879         if (player == NULL) {
 880                 errorstream <<
 881                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 882                         peer_id << " disconnecting peer!" << std::endl;
 883                 DisconnectPeer(peer_id);
 884                 return;
 885         }
 886
 887         PlayerSAO *playersao = player->getPlayerSAO();
 888         assert(playersao);
 889
 890         if (!playersao->isDead())
 891                 return;
 892
 893         RespawnPlayer(peer_id);
 894
 895         actionstream << player->getName() << " respawns at "
 896                         << PP(playersao->getBasePosition() / BS) << std::endl;
 897
 898         // ActiveObject is added to environment in AsyncRunStep after
 899         // the previous addition has been successfully removed
 900 }
 901
 902 bool Server::checkInteractDistance(RemotePlayer *player, const f32 d, const std::string &what)
 903 {
 904         ItemStack selected_item, hand_item;
 905         player->getWieldedItem(&selected_item, &hand_item);
 906         f32 max_d = BS * getToolRange(selected_item.getDefinition(m_itemdef),
 907                         hand_item.getDefinition(m_itemdef));
 908
 909         // Cube diagonal * 1.5 for maximal supported node extents:
 910         // sqrt(3) * 1.5 ≅ 2.6
 911         if (d > max_d + 2.6f * BS) {
 912                 actionstream << "Player " << player->getName()
 913                                 << " tried to access " << what
 914                                 << " from too far: "
 915                                 << "d=" << d << ", max_d=" << max_d
 916                                 << "; ignoring." << std::endl;
 917                 // Call callbacks
 918                 m_script->on_cheat(player->getPlayerSAO(), "interacted_too_far");
 919                 return false;
 920         }
 921         return true;
 922 }
 923
 924 void Server::handleCommand_Interact(NetworkPacket *pkt)
 925 {
 926         /*
 927                 [0] u16 command
 928                 [2] u8 action
 929                 [3] u16 item
 930                 [5] u32 length of the next item (plen)
 931                 [9] serialized PointedThing
 932                 [9 + plen] player position information
 933         */
 934
 935         InteractAction action;
 936         u16 item_i;
 937
 938         *pkt >> (u8 &)action;
 939         *pkt >> item_i;
 940
 941         std::istringstream tmp_is(pkt->readLongString(), std::ios::binary);
 942         PointedThing pointed;
 943         pointed.deSerialize(tmp_is);
 944
 945         verbosestream << "TOSERVER_INTERACT: action=" << (int)action << ", item="
 946                         << item_i << ", pointed=" << pointed.dump() << std::endl;
 947
 948         session_t peer_id = pkt->getPeerId();
 949         RemotePlayer *player = m_env->getPlayer(peer_id);
 950
 951         if (player == NULL) {
 952                 errorstream <<
 953                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 954                         peer_id << " disconnecting peer!" << std::endl;
 955                 DisconnectPeer(peer_id);
 956                 return;
 957         }
 958
 959         PlayerSAO *playersao = player->getPlayerSAO();
 960         if (playersao == NULL) {
 961                 errorstream <<
 962                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
 963                         peer_id << " disconnecting peer!" << std::endl;
 964                 DisconnectPeer(peer_id);
 965                 return;
 966         }
 967
 968         if (playersao->isDead()) {
 969                 actionstream << "Server: " << player->getName()
 970                                 << " tried to interact while dead; ignoring." << std::endl;
 971                 if (pointed.type == POINTEDTHING_NODE) {
 972                         // Re-send block to revert change on client-side
 973                         RemoteClient *client = getClient(peer_id);
 974                         v3s16 blockpos = getNodeBlockPos(pointed.node_undersurface);
 975                         client->SetBlockNotSent(blockpos);
 976                 }
 977                 // Call callbacks
 978                 m_script->on_cheat(playersao, "interacted_while_dead");
 979                 return;
 980         }
 981
 982         process_PlayerPos(player, playersao, pkt);
 983
 984         v3f player_pos = playersao->getLastGoodPosition();
 985
 986         // Update wielded item
 987
 988         if (item_i >= player->getHotbarItemcount()) {
 989                 actionstream << "Player: " << player->getName()
 990                         << " tried to access item=" << item_i
 991                         << " out of hotbar_itemcount="
 992                         << player->getHotbarItemcount()
 993                         << "; ignoring." << std::endl;
 994                 return;
 995         }
 996
 997         playersao->getPlayer()->setWieldIndex(item_i);
 998
 999         // Get pointed to object (NULL if not POINTEDTYPE_OBJECT)
1000         ServerActiveObject *pointed_object = NULL;
1001         if (pointed.type == POINTEDTHING_OBJECT) {
1002                 pointed_object = m_env->getActiveObject(pointed.object_id);
1003                 if (pointed_object == NULL) {
1004                         verbosestream << "TOSERVER_INTERACT: "
1005                                 "pointed object is NULL" << std::endl;
1006                         return;
1007                 }
1008
1009         }
1010
1011         /*
1012                 Make sure the player is allowed to do it
1013         */
1014         if (!checkPriv(player->getName(), "interact")) {
1015                 actionstream << player->getName() << " attempted to interact with " <<
1016                                 pointed.dump() << " without 'interact' privilege" << std::endl;
1017
1018                 if (pointed.type != POINTEDTHING_NODE)
1019                         return;
1020
1021                 // Re-send block to revert change on client-side
1022                 RemoteClient *client = getClient(peer_id);
1023                 // Digging completed -> under
1024                 if (action == INTERACT_DIGGING_COMPLETED) {
1025                         v3s16 blockpos = getNodeBlockPos(pointed.node_undersurface);
1026                         client->SetBlockNotSent(blockpos);
1027                 }
1028                 // Placement -> above
1029                 else if (action == INTERACT_PLACE) {
1030                         v3s16 blockpos = getNodeBlockPos(pointed.node_abovesurface);
1031                         client->SetBlockNotSent(blockpos);
1032                 }
1033                 return;
1034         }
1035
1036         /*
1037                 Check that target is reasonably close
1038         */
1039         static thread_local const bool enable_anticheat =
1040                         !g_settings->getBool("disable_anticheat");
1041
1042         if ((action == INTERACT_START_DIGGING || action == INTERACT_DIGGING_COMPLETED ||
1043                         action == INTERACT_PLACE || action == INTERACT_USE) &&
1044                         enable_anticheat && !isSingleplayer()) {
1045                 v3f target_pos = player_pos;
1046                 if (pointed.type == POINTEDTHING_NODE) {
1047                         target_pos = intToFloat(pointed.node_undersurface, BS);
1048                 } else if (pointed.type == POINTEDTHING_OBJECT) {
1049                         if (playersao->getId() == pointed_object->getId()) {
1050                                 actionstream << "Server: " << player->getName()
1051                                         << " attempted to interact with themselves" << std::endl;
1052                                 m_script->on_cheat(playersao, "interacted_with_self");
1053                                 return;
1054                         }
1055                         target_pos = pointed_object->getBasePosition();
1056                 }
1057                 float d = playersao->getEyePosition().getDistanceFrom(target_pos);
1058
1059                 if (!checkInteractDistance(player, d, pointed.dump())) {
1060                         if (pointed.type == POINTEDTHING_NODE) {
1061                                 // Re-send block to revert change on client-side
1062                                 RemoteClient *client = getClient(peer_id);
1063                                 v3s16 blockpos = getNodeBlockPos(pointed.node_undersurface);
1064                                 client->SetBlockNotSent(blockpos);
1065                         }
1066                         return;
1067                 }
1068         }
1069
1070         /*
1071                 If something goes wrong, this player is to blame
1072         */
1073         RollbackScopeActor rollback_scope(m_rollback,
1074                         std::string("player:")+player->getName());
1075
1076         switch (action) {
1077         // Start digging or punch object
1078         case INTERACT_START_DIGGING: {
1079                 if (pointed.type == POINTEDTHING_NODE) {
1080                         MapNode n(CONTENT_IGNORE);
1081                         bool pos_ok;
1082
1083                         v3s16 p_under = pointed.node_undersurface;
1084                         n = m_env->getMap().getNode(p_under, &pos_ok);
1085                         if (!pos_ok) {
1086                                 infostream << "Server: Not punching: Node not found. "
1087                                         "Adding block to emerge queue." << std::endl;
1088                                 m_emerge->enqueueBlockEmerge(peer_id,
1089                                         getNodeBlockPos(pointed.node_abovesurface), false);
1090                         }
1091
1092                         if (n.getContent() != CONTENT_IGNORE)
1093                                 m_script->node_on_punch(p_under, n, playersao, pointed);
1094
1095                         // Cheat prevention
1096                         playersao->noCheatDigStart(p_under);
1097
1098                         return;
1099                 }
1100
1101                 // Skip if the object can't be interacted with anymore
1102                 if (pointed.type != POINTEDTHING_OBJECT || pointed_object->isGone())
1103                         return;
1104
1105                 ItemStack selected_item, hand_item;
1106                 ItemStack tool_item = playersao->getWieldedItem(&selected_item, &hand_item);
1107                 ToolCapabilities toolcap =
1108                                 tool_item.getToolCapabilities(m_itemdef);
1109                 v3f dir = (pointed_object->getBasePosition() -
1110                                 (playersao->getBasePosition() + playersao->getEyeOffset())
1111                                         ).normalize();
1112                 float time_from_last_punch =
1113                         playersao->resetTimeFromLastPunch();
1114
1115                 u16 wear = pointed_object->punch(dir, &toolcap, playersao,
1116                                 time_from_last_punch);
1117
1118                 // Callback may have changed item, so get it again
1119                 playersao->getWieldedItem(&selected_item);
1120                 bool changed = selected_item.addWear(wear, m_itemdef);
1121                 if (changed)
1122                         playersao->setWieldedItem(selected_item);
1123
1124                 return;
1125         } // action == INTERACT_START_DIGGING
1126
1127         case INTERACT_STOP_DIGGING:
1128                 // Nothing to do
1129                 return;
1130
1131         case INTERACT_DIGGING_COMPLETED: {
1132                 // Only digging of nodes
1133                 if (pointed.type != POINTEDTHING_NODE)
1134                         return;
1135                 bool pos_ok;
1136                 v3s16 p_under = pointed.node_undersurface;
1137                 MapNode n = m_env->getMap().getNode(p_under, &pos_ok);
1138                 if (!pos_ok) {
1139                         infostream << "Server: Not finishing digging: Node not found. "
1140                                 "Adding block to emerge queue." << std::endl;
1141                         m_emerge->enqueueBlockEmerge(peer_id,
1142                                 getNodeBlockPos(pointed.node_abovesurface), false);
1143                 }
1144
1145                 /* Cheat prevention */
1146                 bool is_valid_dig = true;
1147                 if (enable_anticheat && !isSingleplayer()) {
1148                         v3s16 nocheat_p = playersao->getNoCheatDigPos();
1149                         float nocheat_t = playersao->getNoCheatDigTime();
1150                         playersao->noCheatDigEnd();
1151                         // If player didn't start digging this, ignore dig
1152                         if (nocheat_p != p_under) {
1153                                 infostream << "Server: " << player->getName()
1154                                                 << " started digging "
1155                                                 << PP(nocheat_p) << " and completed digging "
1156                                                 << PP(p_under) << "; not digging." << std::endl;
1157                                 is_valid_dig = false;
1158                                 // Call callbacks
1159                                 m_script->on_cheat(playersao, "finished_unknown_dig");
1160                         }
1161
1162                         // Get player's wielded item
1163                         // See also: Game::handleDigging
1164                         ItemStack selected_item, hand_item;
1165                         playersao->getPlayer()->getWieldedItem(&selected_item, &hand_item);
1166
1167                         // Get diggability and expected digging time
1168                         DigParams params = getDigParams(m_nodedef->get(n).groups,
1169                                         &selected_item.getToolCapabilities(m_itemdef));
1170                         // If can't dig, try hand
1171                         if (!params.diggable) {
1172                                 params = getDigParams(m_nodedef->get(n).groups,
1173                                         &hand_item.getToolCapabilities(m_itemdef));
1174                         }
1175                         // If can't dig, ignore dig
1176                         if (!params.diggable) {
1177                                 infostream << "Server: " << player->getName()
1178                                                 << " completed digging " << PP(p_under)
1179                                                 << ", which is not diggable with tool; not digging."
1180                                                 << std::endl;
1181                                 is_valid_dig = false;
1182                                 // Call callbacks
1183                                 m_script->on_cheat(playersao, "dug_unbreakable");
1184                         }
1185                         // Check digging time
1186                         // If already invalidated, we don't have to
1187                         if (!is_valid_dig) {
1188                                 // Well not our problem then
1189                         }
1190                         // Clean and long dig
1191                         else if (params.time > 2.0 && nocheat_t * 1.2 > params.time) {
1192                                 // All is good, but grab time from pool; don't care if
1193                                 // it's actually available
1194                                 playersao->getDigPool().grab(params.time);
1195                         }
1196                         // Short or laggy dig
1197                         // Try getting the time from pool
1198                         else if (playersao->getDigPool().grab(params.time)) {
1199                                 // All is good
1200                         }
1201                         // Dig not possible
1202                         else {
1203                                 infostream << "Server: " << player->getName()
1204                                                 << " completed digging " << PP(p_under)
1205                                                 << "too fast; not digging." << std::endl;
1206                                 is_valid_dig = false;
1207                                 // Call callbacks
1208                                 m_script->on_cheat(playersao, "dug_too_fast");
1209                         }
1210                 }
1211
1212                 /* Actually dig node */
1213
1214                 if (is_valid_dig && n.getContent() != CONTENT_IGNORE)
1215                         m_script->node_on_dig(p_under, n, playersao);
1216
1217                 v3s16 blockpos = getNodeBlockPos(p_under);
1218                 RemoteClient *client = getClient(peer_id);
1219                 // Send unusual result (that is, node not being removed)
1220                 if (m_env->getMap().getNode(p_under).getContent() != CONTENT_AIR)
1221                         // Re-send block to revert change on client-side
1222                         client->SetBlockNotSent(blockpos);
1223                 else
1224                         client->ResendBlockIfOnWire(blockpos);
1225
1226                 return;
1227         } // action == INTERACT_DIGGING_COMPLETED
1228
1229         // Place block or right-click object
1230         case INTERACT_PLACE: {
1231                 ItemStack selected_item;
1232                 playersao->getWieldedItem(&selected_item, nullptr);
1233
1234                 // Reset build time counter
1235                 if (pointed.type == POINTEDTHING_NODE &&
1236                                 selected_item.getDefinition(m_itemdef).type == ITEM_NODE)
1237                         getClient(peer_id)->m_time_from_building = 0.0;
1238
1239                 if (pointed.type == POINTEDTHING_OBJECT) {
1240                         // Right click object
1241
1242                         // Skip if object can't be interacted with anymore
1243                         if (pointed_object->isGone())
1244                                 return;
1245
1246                         actionstream << player->getName() << " right-clicks object "
1247                                         << pointed.object_id << ": "
1248                                         << pointed_object->getDescription() << std::endl;
1249
1250                         // Do stuff
1251                         if (m_script->item_OnSecondaryUse(
1252                                         selected_item, playersao, pointed)) {
1253                                 if (playersao->setWieldedItem(selected_item)) {
1254                                         SendInventory(playersao, true);
1255                                 }
1256                         }
1257
1258                         pointed_object->rightClick(playersao);
1259                 } else if (m_script->item_OnPlace(selected_item, playersao, pointed)) {
1260                         // Placement was handled in lua
1261
1262                         // Apply returned ItemStack
1263                         if (playersao->setWieldedItem(selected_item))
1264                                 SendInventory(playersao, true);
1265                 }
1266
1267                 if (pointed.type != POINTEDTHING_NODE)
1268                         return;
1269
1270                 // If item has node placement prediction, always send the
1271                 // blocks to make sure the client knows what exactly happened
1272                 RemoteClient *client = getClient(peer_id);
1273                 v3s16 blockpos = getNodeBlockPos(pointed.node_abovesurface);
1274                 v3s16 blockpos2 = getNodeBlockPos(pointed.node_undersurface);
1275                 if (!selected_item.getDefinition(m_itemdef
1276                                 ).node_placement_prediction.empty()) {
1277                         client->SetBlockNotSent(blockpos);
1278                         if (blockpos2 != blockpos)
1279                                 client->SetBlockNotSent(blockpos2);
1280                 } else {
1281                         client->ResendBlockIfOnWire(blockpos);
1282                         if (blockpos2 != blockpos)
1283                                 client->ResendBlockIfOnWire(blockpos2);
1284                 }
1285
1286                 return;
1287         } // action == INTERACT_PLACE
1288
1289         case INTERACT_USE: {
1290                 ItemStack selected_item;
1291                 playersao->getWieldedItem(&selected_item, nullptr);
1292
1293                 actionstream << player->getName() << " uses " << selected_item.name
1294                                 << ", pointing at " << pointed.dump() << std::endl;
1295
1296                 if (m_script->item_OnUse(selected_item, playersao, pointed)) {
1297                         // Apply returned ItemStack
1298                         if (playersao->setWieldedItem(selected_item))
1299                                 SendInventory(playersao, true);
1300                 }
1301
1302                 return;
1303         }
1304
1305         // Rightclick air
1306         case INTERACT_ACTIVATE: {
1307                 ItemStack selected_item;
1308                 playersao->getWieldedItem(&selected_item, nullptr);
1309
1310                 actionstream << player->getName() << " activates "
1311                                 << selected_item.name << std::endl;
1312
1313                 pointed.type = POINTEDTHING_NOTHING; // can only ever be NOTHING
1314
1315                 if (m_script->item_OnSecondaryUse(selected_item, playersao, pointed)) {
1316                         if (playersao->setWieldedItem(selected_item))
1317                                 SendInventory(playersao, true);
1318                 }
1319
1320                 return;
1321         }
1322
1323         default:
1324                 warningstream << "Server: Invalid action " << action << std::endl;
1325
1326         }
1327 }
1328
1329 void Server::handleCommand_RemovedSounds(NetworkPacket* pkt)
1330 {
1331         u16 num;
1332         *pkt >> num;
1333         for (u16 k = 0; k < num; k++) {
1334                 s32 id;
1335
1336                 *pkt >> id;
1337
1338                 std::unordered_map<s32, ServerPlayingSound>::iterator i =
1339                         m_playing_sounds.find(id);
1340                 if (i == m_playing_sounds.end())
1341                         continue;
1342
1343                 ServerPlayingSound &psound = i->second;
1344                 psound.clients.erase(pkt->getPeerId());
1345                 if (psound.clients.empty())
1346                         m_playing_sounds.erase(i++);
1347         }
1348 }
1349
1350 void Server::handleCommand_NodeMetaFields(NetworkPacket* pkt)
1351 {
1352         v3s16 p;
1353         std::string formname;
1354         u16 num;
1355
1356         *pkt >> p >> formname >> num;
1357
1358         StringMap fields;
1359         for (u16 k = 0; k < num; k++) {
1360                 std::string fieldname;
1361                 *pkt >> fieldname;
1362                 fields[fieldname] = pkt->readLongString();
1363         }
1364
1365         session_t peer_id = pkt->getPeerId();
1366         RemotePlayer *player = m_env->getPlayer(peer_id);
1367
1368         if (player == NULL) {
1369                 errorstream <<
1370                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
1371                         peer_id << " disconnecting peer!" << std::endl;
1372                 DisconnectPeer(peer_id);
1373                 return;
1374         }
1375
1376         PlayerSAO *playersao = player->getPlayerSAO();
1377         if (playersao == NULL) {
1378                 errorstream <<
1379                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
1380                         peer_id << " disconnecting peer!" << std::endl;
1381                 DisconnectPeer(peer_id);
1382                 return;
1383         }
1384
1385         // If something goes wrong, this player is to blame
1386         RollbackScopeActor rollback_scope(m_rollback,
1387                         std::string("player:")+player->getName());
1388
1389         // Check the target node for rollback data; leave others unnoticed
1390         RollbackNode rn_old(&m_env->getMap(), p, this);
1391
1392         m_script->node_on_receive_fields(p, formname, fields, playersao);
1393
1394         // Report rollback data
1395         RollbackNode rn_new(&m_env->getMap(), p, this);
1396         if (rollback() && rn_new != rn_old) {
1397                 RollbackAction action;
1398                 action.setSetNode(p, rn_old, rn_new);
1399                 rollback()->reportAction(action);
1400         }
1401 }
1402
1403 void Server::handleCommand_InventoryFields(NetworkPacket* pkt)
1404 {
1405         std::string client_formspec_name;
1406         u16 num;
1407
1408         *pkt >> client_formspec_name >> num;
1409
1410         StringMap fields;
1411         for (u16 k = 0; k < num; k++) {
1412                 std::string fieldname;
1413                 *pkt >> fieldname;
1414                 fields[fieldname] = pkt->readLongString();
1415         }
1416
1417         session_t peer_id = pkt->getPeerId();
1418         RemotePlayer *player = m_env->getPlayer(peer_id);
1419
1420         if (player == NULL) {
1421                 errorstream <<
1422                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
1423                         peer_id << " disconnecting peer!" << std::endl;
1424                 DisconnectPeer(peer_id);
1425                 return;
1426         }
1427
1428         PlayerSAO *playersao = player->getPlayerSAO();
1429         if (playersao == NULL) {
1430                 errorstream <<
1431                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
1432                         peer_id << " disconnecting peer!" << std::endl;
1433                 DisconnectPeer(peer_id);
1434                 return;
1435         }
1436
1437         if (client_formspec_name.empty()) { // pass through inventory submits
1438                 m_script->on_playerReceiveFields(playersao, client_formspec_name, fields);
1439                 return;
1440         }
1441
1442         // verify that we displayed the formspec to the user
1443         const auto peer_state_iterator = m_formspec_state_data.find(peer_id);
1444         if (peer_state_iterator != m_formspec_state_data.end()) {
1445                 const std::string &server_formspec_name = peer_state_iterator->second;
1446                 if (client_formspec_name == server_formspec_name) {
1447                         auto it = fields.find("quit");
1448                         if (it != fields.end() && it->second == "true")
1449                                 m_formspec_state_data.erase(peer_state_iterator);
1450
1451                         m_script->on_playerReceiveFields(playersao, client_formspec_name, fields);
1452                         return;
1453                 }
1454                 actionstream << "'" << player->getName()
1455                         << "' submitted formspec ('" << client_formspec_name
1456                         << "') but the name of the formspec doesn't match the"
1457                         " expected name ('" << server_formspec_name << "')";
1458
1459         } else {
1460                 actionstream << "'" << player->getName()
1461                         << "' submitted formspec ('" << client_formspec_name
1462                         << "') but server hasn't sent formspec to client";
1463         }
1464         actionstream << ", possible exploitation attempt" << std::endl;
1465 }
1466
1467 void Server::handleCommand_FirstSrp(NetworkPacket* pkt)
1468 {
1469         session_t peer_id = pkt->getPeerId();
1470         RemoteClient *client = getClient(peer_id, CS_Invalid);
1471         ClientState cstate = client->getState();
1472
1473         std::string playername = client->getName();
1474
1475         std::string salt;
1476         std::string verification_key;
1477
1478         std::string addr_s = getPeerAddress(peer_id).serializeString();
1479         u8 is_empty;
1480
1481         *pkt >> salt >> verification_key >> is_empty;
1482
1483         verbosestream << "Server: Got TOSERVER_FIRST_SRP from " << addr_s
1484                 << ", with is_empty=" << (is_empty == 1) << std::endl;
1485
1486         // Either this packet is sent because the user is new or to change the password
1487         if (cstate == CS_HelloSent) {
1488                 if (!client->isMechAllowed(AUTH_MECHANISM_FIRST_SRP)) {
1489                         actionstream << "Server: Client from " << addr_s
1490                                         << " tried to set password without being "
1491                                         << "authenticated, or the username being new." << std::endl;
1492                         DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1493                         return;
1494                 }
1495
1496                 if (!isSingleplayer() &&
1497                                 g_settings->getBool("disallow_empty_password") &&
1498                                 is_empty == 1) {
1499                         actionstream << "Server: " << playername
1500                                         << " supplied empty password from " << addr_s << std::endl;
1501                         DenyAccess(peer_id, SERVER_ACCESSDENIED_EMPTY_PASSWORD);
1502                         return;
1503                 }
1504
1505                 std::string initial_ver_key;
1506
1507                 initial_ver_key = encode_srp_verifier(verification_key, salt);
1508                 m_script->createAuth(playername, initial_ver_key);
1509                 m_script->on_authplayer(playername, addr_s, true);
1510
1511                 acceptAuth(peer_id, false);
1512         } else {
1513                 if (cstate < CS_SudoMode) {
1514                         infostream << "Server::ProcessData(): Ignoring TOSERVER_FIRST_SRP from "
1515                                         << addr_s << ": " << "Client has wrong state " << cstate << "."
1516                                         << std::endl;
1517                         return;
1518                 }
1519                 m_clients.event(peer_id, CSE_SudoLeave);
1520                 std::string pw_db_field = encode_srp_verifier(verification_key, salt);
1521                 bool success = m_script->setPassword(playername, pw_db_field);
1522                 if (success) {
1523                         actionstream << playername << " changes password" << std::endl;
1524                         SendChatMessage(peer_id, ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
1525                                 L"Password change successful."));
1526                 } else {
1527                         actionstream << playername <<
1528                                 " tries to change password but it fails" << std::endl;
1529                         SendChatMessage(peer_id, ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
1530                                 L"Password change failed or unavailable."));
1531                 }
1532         }
1533 }
1534
1535 void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
1536 {
1537         session_t peer_id = pkt->getPeerId();
1538         RemoteClient *client = getClient(peer_id, CS_Invalid);
1539         ClientState cstate = client->getState();
1540
1541         bool wantSudo = (cstate == CS_Active);
1542
1543         if (!((cstate == CS_HelloSent) || (cstate == CS_Active))) {
1544                 actionstream << "Server: got SRP _A packet in wrong state " << cstate <<
1545                         " from " << getPeerAddress(peer_id).serializeString() <<
1546                         ". Ignoring." << std::endl;
1547                 return;
1548         }
1549
1550         if (client->chosen_mech != AUTH_MECHANISM_NONE) {
1551                 actionstream << "Server: got SRP _A packet, while auth is already "
1552                         "going on with mech " << client->chosen_mech << " from " <<
1553                         getPeerAddress(peer_id).serializeString() <<
1554                         " (wantSudo=" << wantSudo << "). Ignoring." << std::endl;
1555                 if (wantSudo) {
1556                         DenySudoAccess(peer_id);
1557                         return;
1558                 }
1559
1560                 DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1561                 return;
1562         }
1563
1564         std::string bytes_A;
1565         u8 based_on;
1566         *pkt >> bytes_A >> based_on;
1567
1568         infostream << "Server: TOSERVER_SRP_BYTES_A received with "
1569                 << "based_on=" << int(based_on) << " and len_A="
1570                 << bytes_A.length() << "." << std::endl;
1571
1572         AuthMechanism chosen = (based_on == 0) ?
1573                 AUTH_MECHANISM_LEGACY_PASSWORD : AUTH_MECHANISM_SRP;
1574
1575         if (wantSudo) {
1576                 if (!client->isSudoMechAllowed(chosen)) {
1577                         actionstream << "Server: Player \"" << client->getName() <<
1578                                 "\" at " << getPeerAddress(peer_id).serializeString() <<
1579                                 " tried to change password using unallowed mech " << chosen <<
1580                                 "." << std::endl;
1581                         DenySudoAccess(peer_id);
1582                         return;
1583                 }
1584         } else {
1585                 if (!client->isMechAllowed(chosen)) {
1586                         actionstream << "Server: Client tried to authenticate from " <<
1587                                 getPeerAddress(peer_id).serializeString() <<
1588                                 " using unallowed mech " << chosen << "." << std::endl;
1589                         DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1590                         return;
1591                 }
1592         }
1593
1594         client->chosen_mech = chosen;
1595
1596         std::string salt;
1597         std::string verifier;
1598
1599         if (based_on == 0) {
1600
1601                 generate_srp_verifier_and_salt(client->getName(), client->enc_pwd,
1602                         &verifier, &salt);
1603         } else if (!decode_srp_verifier_and_salt(client->enc_pwd, &verifier, &salt)) {
1604                 // Non-base64 errors should have been catched in the init handler
1605                 actionstream << "Server: User " << client->getName() <<
1606                         " tried to log in, but srp verifier field was invalid (most likely "
1607                         "invalid base64)." << std::endl;
1608                 DenyAccess(peer_id, SERVER_ACCESSDENIED_SERVER_FAIL);
1609                 return;
1610         }
1611
1612         char *bytes_B = 0;
1613         size_t len_B = 0;
1614
1615         client->auth_data = srp_verifier_new(SRP_SHA256, SRP_NG_2048,
1616                 client->getName().c_str(),
1617                 (const unsigned char *) salt.c_str(), salt.size(),
1618                 (const unsigned char *) verifier.c_str(), verifier.size(),
1619                 (const unsigned char *) bytes_A.c_str(), bytes_A.size(),
1620                 NULL, 0,
1621                 (unsigned char **) &bytes_B, &len_B, NULL, NULL);
1622
1623         if (!bytes_B) {
1624                 actionstream << "Server: User " << client->getName()
1625                         << " tried to log in, SRP-6a safety check violated in _A handler."
1626                         << std::endl;
1627                 if (wantSudo) {
1628                         DenySudoAccess(peer_id);
1629                         return;
1630                 }
1631
1632                 DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1633                 return;
1634         }
1635
1636         NetworkPacket resp_pkt(TOCLIENT_SRP_BYTES_S_B, 0, peer_id);
1637         resp_pkt << salt << std::string(bytes_B, len_B);
1638         Send(&resp_pkt);
1639 }
1640
1641 void Server::handleCommand_SrpBytesM(NetworkPacket* pkt)
1642 {
1643         session_t peer_id = pkt->getPeerId();
1644         RemoteClient *client = getClient(peer_id, CS_Invalid);
1645         ClientState cstate = client->getState();
1646         std::string addr_s = getPeerAddress(pkt->getPeerId()).serializeString();
1647         std::string playername = client->getName();
1648
1649         bool wantSudo = (cstate == CS_Active);
1650
1651         verbosestream << "Server: Received TOSERVER_SRP_BYTES_M." << std::endl;
1652
1653         if (!((cstate == CS_HelloSent) || (cstate == CS_Active))) {
1654                 warningstream << "Server: got SRP_M packet in wrong state "
1655                         << cstate << " from " << addr_s << ". Ignoring." << std::endl;
1656                 return;
1657         }
1658
1659         if (client->chosen_mech != AUTH_MECHANISM_SRP &&
1660                         client->chosen_mech != AUTH_MECHANISM_LEGACY_PASSWORD) {
1661                 warningstream << "Server: got SRP_M packet, while auth "
1662                         "is going on with mech " << client->chosen_mech << " from "
1663                         << addr_s << " (wantSudo=" << wantSudo << "). Denying." << std::endl;
1664                 if (wantSudo) {
1665                         DenySudoAccess(peer_id);
1666                         return;
1667                 }
1668
1669                 DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1670                 return;
1671         }
1672
1673         std::string bytes_M;
1674         *pkt >> bytes_M;
1675
1676         if (srp_verifier_get_session_key_length((SRPVerifier *) client->auth_data)
1677                         != bytes_M.size()) {
1678                 actionstream << "Server: User " << playername << " at " << addr_s
1679                         << " sent bytes_M with invalid length " << bytes_M.size() << std::endl;
1680                 DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1681                 return;
1682         }
1683
1684         unsigned char *bytes_HAMK = 0;
1685
1686         srp_verifier_verify_session((SRPVerifier *) client->auth_data,
1687                 (unsigned char *)bytes_M.c_str(), &bytes_HAMK);
1688
1689         if (!bytes_HAMK) {
1690                 if (wantSudo) {
1691                         actionstream << "Server: User " << playername << " at " << addr_s
1692                                 << " tried to change their password, but supplied wrong"
1693                                 << " (SRP) password for authentication." << std::endl;
1694                         DenySudoAccess(peer_id);
1695                         return;
1696                 }
1697
1698                 actionstream << "Server: User " << playername << " at " << addr_s
1699                         << " supplied wrong password (auth mechanism: SRP)." << std::endl;
1700                 m_script->on_authplayer(playername, addr_s, false);
1701                 DenyAccess(peer_id, SERVER_ACCESSDENIED_WRONG_PASSWORD);
1702                 return;
1703         }
1704
1705         if (client->create_player_on_auth_success) {
1706                 m_script->createAuth(playername, client->enc_pwd);
1707
1708                 std::string checkpwd; // not used, but needed for passing something
1709                 if (!m_script->getAuth(playername, &checkpwd, NULL)) {
1710                         errorstream << "Server: " << playername <<
1711                                 " cannot be authenticated (auth handler does not work?)" <<
1712                                 std::endl;
1713                         DenyAccess(peer_id, SERVER_ACCESSDENIED_SERVER_FAIL);
1714                         return;
1715                 }
1716                 client->create_player_on_auth_success = false;
1717         }
1718
1719         m_script->on_authplayer(playername, addr_s, true);
1720         acceptAuth(peer_id, wantSudo);
1721 }
1722
1723 /*
1724  * Mod channels
1725  */
1726
1727 void Server::handleCommand_ModChannelJoin(NetworkPacket *pkt)
1728 {
1729         std::string channel_name;
1730         *pkt >> channel_name;
1731
1732         session_t peer_id = pkt->getPeerId();
1733         NetworkPacket resp_pkt(TOCLIENT_MODCHANNEL_SIGNAL,
1734                 1 + 2 + channel_name.size(), peer_id);
1735
1736         // Send signal to client to notify join succeed or not
1737         if (g_settings->getBool("enable_mod_channels") &&
1738                         m_modchannel_mgr->joinChannel(channel_name, peer_id)) {
1739                 resp_pkt << (u8) MODCHANNEL_SIGNAL_JOIN_OK;
1740                 infostream << "Peer " << peer_id << " joined channel " <<
1741                         channel_name << std::endl;
1742         }
1743         else {
1744                 resp_pkt << (u8)MODCHANNEL_SIGNAL_JOIN_FAILURE;
1745                 infostream << "Peer " << peer_id << " tried to join channel " <<
1746                         channel_name << ", but was already registered." << std::endl;
1747         }
1748         resp_pkt << channel_name;
1749         Send(&resp_pkt);
1750 }
1751
1752 void Server::handleCommand_ModChannelLeave(NetworkPacket *pkt)
1753 {
1754         std::string channel_name;
1755         *pkt >> channel_name;
1756
1757         session_t peer_id = pkt->getPeerId();
1758         NetworkPacket resp_pkt(TOCLIENT_MODCHANNEL_SIGNAL,
1759                 1 + 2 + channel_name.size(), peer_id);
1760
1761         // Send signal to client to notify join succeed or not
1762         if (g_settings->getBool("enable_mod_channels") &&
1763                         m_modchannel_mgr->leaveChannel(channel_name, peer_id)) {
1764                 resp_pkt << (u8)MODCHANNEL_SIGNAL_LEAVE_OK;
1765                 infostream << "Peer " << peer_id << " left channel " << channel_name <<
1766                         std::endl;
1767         } else {
1768                 resp_pkt << (u8) MODCHANNEL_SIGNAL_LEAVE_FAILURE;
1769                 infostream << "Peer " << peer_id << " left channel " << channel_name <<
1770                         ", but was not registered." << std::endl;
1771         }
1772         resp_pkt << channel_name;
1773         Send(&resp_pkt);
1774 }
1775
1776 void Server::handleCommand_ModChannelMsg(NetworkPacket *pkt)
1777 {
1778         std::string channel_name, channel_msg;
1779         *pkt >> channel_name >> channel_msg;
1780
1781         session_t peer_id = pkt->getPeerId();
1782         verbosestream << "Mod channel message received from peer " << peer_id <<
1783                 " on channel " << channel_name << " message: " << channel_msg <<
1784                 std::endl;
1785
1786         // If mod channels are not enabled, discard message
1787         if (!g_settings->getBool("enable_mod_channels")) {
1788                 return;
1789         }
1790
1791         // If channel not registered, signal it and ignore message
1792         if (!m_modchannel_mgr->channelRegistered(channel_name)) {
1793                 NetworkPacket resp_pkt(TOCLIENT_MODCHANNEL_SIGNAL,
1794                         1 + 2 + channel_name.size(), peer_id);
1795                 resp_pkt << (u8)MODCHANNEL_SIGNAL_CHANNEL_NOT_REGISTERED << channel_name;
1796                 Send(&resp_pkt);
1797                 return;
1798         }
1799
1800         // @TODO: filter, rate limit
1801
1802         broadcastModChannelMessage(channel_name, channel_msg, peer_id);
1803 }