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.up    = (keyPressed & (0x1 << 0));
 514         player->control.down  = (keyPressed & (0x1 << 1));
 515         player->control.left  = (keyPressed & (0x1 << 2));
 516         player->control.right = (keyPressed & (0x1 << 3));
 517         player->control.jump  = (keyPressed & (0x1 << 4));
 518         player->control.aux1  = (keyPressed & (0x1 << 5));
 519         player->control.sneak = (keyPressed & (0x1 << 6));
 520         player->control.dig   = (keyPressed & (0x1 << 7));
 521         player->control.place = (keyPressed & (0x1 << 8));
 522         player->control.zoom  = (keyPressed & (0x1 << 9));
 523
 524         if (playersao->checkMovementCheat()) {
 525                 // Call callbacks
 526                 m_script->on_cheat(playersao, "moved_too_fast");
 527                 SendMovePlayer(pkt->getPeerId());
 528         }
 529 }
 530
 531 void Server::handleCommand_PlayerPos(NetworkPacket* pkt)
 532 {
 533         session_t peer_id = pkt->getPeerId();
 534         RemotePlayer *player = m_env->getPlayer(peer_id);
 535         if (player == NULL) {
 536                 errorstream <<
 537                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 538                         peer_id << " disconnecting peer!" << std::endl;
 539                 DisconnectPeer(peer_id);
 540                 return;
 541         }
 542
 543         PlayerSAO *playersao = player->getPlayerSAO();
 544         if (playersao == NULL) {
 545                 errorstream <<
 546                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
 547                         peer_id << " disconnecting peer!" << std::endl;
 548                 DisconnectPeer(peer_id);
 549                 return;
 550         }
 551
 552         // If player is dead we don't care of this packet
 553         if (playersao->isDead()) {
 554                 verbosestream << "TOSERVER_PLAYERPOS: " << player->getName()
 555                                 << " is dead. Ignoring packet";
 556                 return;
 557         }
 558
 559         process_PlayerPos(player, playersao, pkt);
 560 }
 561
 562 void Server::handleCommand_DeletedBlocks(NetworkPacket* pkt)
 563 {
 564         if (pkt->getSize() < 1)
 565                 return;
 566
 567         /*
 568                 [0] u16 command
 569                 [2] u8 count
 570                 [3] v3s16 pos_0
 571                 [3+6] v3s16 pos_1
 572                 ...
 573         */
 574
 575         u8 count;
 576         *pkt >> count;
 577
 578         RemoteClient *client = getClient(pkt->getPeerId());
 579
 580         if ((s16)pkt->getSize() < 1 + (int)count * 6) {
 581                 throw con::InvalidIncomingDataException
 582                                 ("DELETEDBLOCKS length is too short");
 583         }
 584
 585         for (u16 i = 0; i < count; i++) {
 586                 v3s16 p;
 587                 *pkt >> p;
 588                 client->SetBlockNotSent(p);
 589         }
 590 }
 591
 592 void Server::handleCommand_InventoryAction(NetworkPacket* pkt)
 593 {
 594         session_t peer_id = pkt->getPeerId();
 595         RemotePlayer *player = m_env->getPlayer(peer_id);
 596
 597         if (player == NULL) {
 598                 errorstream <<
 599                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 600                         peer_id << " disconnecting peer!" << std::endl;
 601                 DisconnectPeer(peer_id);
 602                 return;
 603         }
 604
 605         PlayerSAO *playersao = player->getPlayerSAO();
 606         if (playersao == NULL) {
 607                 errorstream <<
 608                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
 609                         peer_id << " disconnecting peer!" << std::endl;
 610                 DisconnectPeer(peer_id);
 611                 return;
 612         }
 613
 614         // Strip command and create a stream
 615         std::string datastring(pkt->getString(0), pkt->getSize());
 616         verbosestream << "TOSERVER_INVENTORY_ACTION: data=" << datastring
 617                 << std::endl;
 618         std::istringstream is(datastring, std::ios_base::binary);
 619         // Create an action
 620         std::unique_ptr<InventoryAction> a(InventoryAction::deSerialize(is));
 621         if (!a) {
 622                 infostream << "TOSERVER_INVENTORY_ACTION: "
 623                                 << "InventoryAction::deSerialize() returned NULL"
 624                                 << std::endl;
 625                 return;
 626         }
 627
 628         // If something goes wrong, this player is to blame
 629         RollbackScopeActor rollback_scope(m_rollback,
 630                         std::string("player:")+player->getName());
 631
 632         /*
 633                 Note: Always set inventory not sent, to repair cases
 634                 where the client made a bad prediction.
 635         */
 636
 637         const bool player_has_interact = checkPriv(player->getName(), "interact");
 638
 639         auto check_inv_access = [player, player_has_interact, this] (
 640                         const InventoryLocation &loc) -> bool {
 641
 642                 // Players without interact may modify their own inventory
 643                 if (!player_has_interact && loc.type != InventoryLocation::PLAYER) {
 644                         infostream << "Cannot modify foreign inventory: "
 645                                         << "No interact privilege" << std::endl;
 646                         return false;
 647                 }
 648
 649                 switch (loc.type) {
 650                 case InventoryLocation::CURRENT_PLAYER:
 651                         // Only used internally on the client, never sent
 652                         return false;
 653                 case InventoryLocation::PLAYER:
 654                         // Allow access to own inventory in all cases
 655                         return loc.name == player->getName();
 656                 case InventoryLocation::NODEMETA:
 657                         {
 658                                 // Check for out-of-range interaction
 659                                 v3f node_pos   = intToFloat(loc.p, BS);
 660                                 v3f player_pos = player->getPlayerSAO()->getEyePosition();
 661                                 f32 d = player_pos.getDistanceFrom(node_pos);
 662                                 return checkInteractDistance(player, d, "inventory");
 663                         }
 664                 case InventoryLocation::DETACHED:
 665                         return getInventoryMgr()->checkDetachedInventoryAccess(loc, player->getName());
 666                 default:
 667                         return false;
 668                 }
 669         };
 670
 671         /*
 672                 Handle restrictions and special cases of the move action
 673         */
 674         if (a->getType() == IAction::Move) {
 675                 IMoveAction *ma = (IMoveAction*)a.get();
 676
 677                 ma->from_inv.applyCurrentPlayer(player->getName());
 678                 ma->to_inv.applyCurrentPlayer(player->getName());
 679
 680                 m_inventory_mgr->setInventoryModified(ma->from_inv);
 681                 if (ma->from_inv != ma->to_inv)
 682                         m_inventory_mgr->setInventoryModified(ma->to_inv);
 683
 684                 if (!check_inv_access(ma->from_inv) ||
 685                                 !check_inv_access(ma->to_inv))
 686                         return;
 687
 688                 /*
 689                         Disable moving items out of craftpreview
 690                 */
 691                 if (ma->from_list == "craftpreview") {
 692                         infostream << "Ignoring IMoveAction from "
 693                                         << (ma->from_inv.dump()) << ":" << ma->from_list
 694                                         << " to " << (ma->to_inv.dump()) << ":" << ma->to_list
 695                                         << " because src is " << ma->from_list << std::endl;
 696                         return;
 697                 }
 698
 699                 /*
 700                         Disable moving items into craftresult and craftpreview
 701                 */
 702                 if (ma->to_list == "craftpreview" || ma->to_list == "craftresult") {
 703                         infostream << "Ignoring IMoveAction from "
 704                                         << (ma->from_inv.dump()) << ":" << ma->from_list
 705                                         << " to " << (ma->to_inv.dump()) << ":" << ma->to_list
 706                                         << " because dst is " << ma->to_list << std::endl;
 707                         return;
 708                 }
 709         }
 710         /*
 711                 Handle restrictions and special cases of the drop action
 712         */
 713         else if (a->getType() == IAction::Drop) {
 714                 IDropAction *da = (IDropAction*)a.get();
 715
 716                 da->from_inv.applyCurrentPlayer(player->getName());
 717
 718                 m_inventory_mgr->setInventoryModified(da->from_inv);
 719
 720                 /*
 721                         Disable dropping items out of craftpreview
 722                 */
 723                 if (da->from_list == "craftpreview") {
 724                         infostream << "Ignoring IDropAction from "
 725                                         << (da->from_inv.dump()) << ":" << da->from_list
 726                                         << " because src is " << da->from_list << std::endl;
 727                         return;
 728                 }
 729
 730                 // Disallow dropping items if not allowed to interact
 731                 if (!player_has_interact || !check_inv_access(da->from_inv))
 732                         return;
 733
 734                 // Disallow dropping items if dead
 735                 if (playersao->isDead()) {
 736                         infostream << "Ignoring IDropAction from "
 737                                         << (da->from_inv.dump()) << ":" << da->from_list
 738                                         << " because player is dead." << std::endl;
 739                         return;
 740                 }
 741         }
 742         /*
 743                 Handle restrictions and special cases of the craft action
 744         */
 745         else if (a->getType() == IAction::Craft) {
 746                 ICraftAction *ca = (ICraftAction*)a.get();
 747
 748                 ca->craft_inv.applyCurrentPlayer(player->getName());
 749
 750                 m_inventory_mgr->setInventoryModified(ca->craft_inv);
 751
 752                 // Disallow crafting if not allowed to interact
 753                 if (!player_has_interact) {
 754                         infostream << "Cannot craft: "
 755                                         << "No interact privilege" << std::endl;
 756                         return;
 757                 }
 758
 759                 if (!check_inv_access(ca->craft_inv))
 760                         return;
 761         } else {
 762                 // Unknown action. Ignored.
 763                 return;
 764         }
 765
 766         // Do the action
 767         a->apply(m_inventory_mgr.get(), playersao, this);
 768 }
 769
 770 void Server::handleCommand_ChatMessage(NetworkPacket* pkt)
 771 {
 772         std::wstring message;
 773         *pkt >> message;
 774
 775         session_t peer_id = pkt->getPeerId();
 776         RemotePlayer *player = m_env->getPlayer(peer_id);
 777         if (player == NULL) {
 778                 errorstream <<
 779                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 780                         peer_id << " disconnecting peer!" << std::endl;
 781                 DisconnectPeer(peer_id);
 782                 return;
 783         }
 784
 785         std::string name = player->getName();
 786
 787         std::wstring answer_to_sender = handleChat(name, message, true, player);
 788         if (!answer_to_sender.empty()) {
 789                 // Send the answer to sender
 790                 SendChatMessage(peer_id, ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
 791                         answer_to_sender));
 792         }
 793 }
 794
 795 void Server::handleCommand_Damage(NetworkPacket* pkt)
 796 {
 797         u16 damage;
 798
 799         *pkt >> damage;
 800
 801         session_t peer_id = pkt->getPeerId();
 802         RemotePlayer *player = m_env->getPlayer(peer_id);
 803
 804         if (player == NULL) {
 805                 errorstream <<
 806                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 807                         peer_id << " disconnecting peer!" << std::endl;
 808                 DisconnectPeer(peer_id);
 809                 return;
 810         }
 811
 812         PlayerSAO *playersao = player->getPlayerSAO();
 813         if (playersao == NULL) {
 814                 errorstream <<
 815                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
 816                         peer_id << " disconnecting peer!" << std::endl;
 817                 DisconnectPeer(peer_id);
 818                 return;
 819         }
 820
 821         if (!playersao->isImmortal()) {
 822                 if (playersao->isDead()) {
 823                         verbosestream << "Server::ProcessData(): Info: "
 824                                 "Ignoring damage as player " << player->getName()
 825                                 << " is already dead." << std::endl;
 826                         return;
 827                 }
 828
 829                 actionstream << player->getName() << " damaged by "
 830                                 << (int)damage << " hp at " << PP(playersao->getBasePosition() / BS)
 831                                 << std::endl;
 832
 833                 PlayerHPChangeReason reason(PlayerHPChangeReason::FALL);
 834                 playersao->setHP((s32)playersao->getHP() - (s32)damage, reason);
 835                 SendPlayerHPOrDie(playersao, reason);
 836         }
 837 }
 838
 839 void Server::handleCommand_PlayerItem(NetworkPacket* pkt)
 840 {
 841         if (pkt->getSize() < 2)
 842                 return;
 843
 844         session_t peer_id = pkt->getPeerId();
 845         RemotePlayer *player = m_env->getPlayer(peer_id);
 846
 847         if (player == NULL) {
 848                 errorstream <<
 849                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 850                         peer_id << " disconnecting peer!" << std::endl;
 851                 DisconnectPeer(peer_id);
 852                 return;
 853         }
 854
 855         PlayerSAO *playersao = player->getPlayerSAO();
 856         if (playersao == NULL) {
 857                 errorstream <<
 858                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
 859                         peer_id << " disconnecting peer!" << std::endl;
 860                 DisconnectPeer(peer_id);
 861                 return;
 862         }
 863
 864         u16 item;
 865
 866         *pkt >> item;
 867
 868         if (item >= player->getHotbarItemcount()) {
 869                 actionstream << "Player: " << player->getName()
 870                         << " tried to access item=" << item
 871                         << " out of hotbar_itemcount="
 872                         << player->getHotbarItemcount()
 873                         << "; ignoring." << std::endl;
 874                 return;
 875         }
 876
 877         playersao->getPlayer()->setWieldIndex(item);
 878 }
 879
 880 void Server::handleCommand_Respawn(NetworkPacket* pkt)
 881 {
 882         session_t peer_id = pkt->getPeerId();
 883         RemotePlayer *player = m_env->getPlayer(peer_id);
 884         if (player == NULL) {
 885                 errorstream <<
 886                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 887                         peer_id << " disconnecting peer!" << std::endl;
 888                 DisconnectPeer(peer_id);
 889                 return;
 890         }
 891
 892         PlayerSAO *playersao = player->getPlayerSAO();
 893         assert(playersao);
 894
 895         if (!playersao->isDead())
 896                 return;
 897
 898         RespawnPlayer(peer_id);
 899
 900         actionstream << player->getName() << " respawns at "
 901                         << PP(playersao->getBasePosition() / BS) << std::endl;
 902
 903         // ActiveObject is added to environment in AsyncRunStep after
 904         // the previous addition has been successfully removed
 905 }
 906
 907 bool Server::checkInteractDistance(RemotePlayer *player, const f32 d, const std::string &what)
 908 {
 909         ItemStack selected_item, hand_item;
 910         player->getWieldedItem(&selected_item, &hand_item);
 911         f32 max_d = BS * getToolRange(selected_item.getDefinition(m_itemdef),
 912                         hand_item.getDefinition(m_itemdef));
 913
 914         // Cube diagonal * 1.5 for maximal supported node extents:
 915         // sqrt(3) * 1.5 ≅ 2.6
 916         if (d > max_d + 2.6f * BS) {
 917                 actionstream << "Player " << player->getName()
 918                                 << " tried to access " << what
 919                                 << " from too far: "
 920                                 << "d=" << d << ", max_d=" << max_d
 921                                 << "; ignoring." << std::endl;
 922                 // Call callbacks
 923                 m_script->on_cheat(player->getPlayerSAO(), "interacted_too_far");
 924                 return false;
 925         }
 926         return true;
 927 }
 928
 929 void Server::handleCommand_Interact(NetworkPacket *pkt)
 930 {
 931         /*
 932                 [0] u16 command
 933                 [2] u8 action
 934                 [3] u16 item
 935                 [5] u32 length of the next item (plen)
 936                 [9] serialized PointedThing
 937                 [9 + plen] player position information
 938         */
 939
 940         InteractAction action;
 941         u16 item_i;
 942
 943         *pkt >> (u8 &)action;
 944         *pkt >> item_i;
 945
 946         std::istringstream tmp_is(pkt->readLongString(), std::ios::binary);
 947         PointedThing pointed;
 948         pointed.deSerialize(tmp_is);
 949
 950         verbosestream << "TOSERVER_INTERACT: action=" << (int)action << ", item="
 951                         << item_i << ", pointed=" << pointed.dump() << std::endl;
 952
 953         session_t peer_id = pkt->getPeerId();
 954         RemotePlayer *player = m_env->getPlayer(peer_id);
 955
 956         if (player == NULL) {
 957                 errorstream <<
 958                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
 959                         peer_id << " disconnecting peer!" << std::endl;
 960                 DisconnectPeer(peer_id);
 961                 return;
 962         }
 963
 964         PlayerSAO *playersao = player->getPlayerSAO();
 965         if (playersao == NULL) {
 966                 errorstream <<
 967                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
 968                         peer_id << " disconnecting peer!" << std::endl;
 969                 DisconnectPeer(peer_id);
 970                 return;
 971         }
 972
 973         if (playersao->isDead()) {
 974                 actionstream << "Server: " << player->getName()
 975                                 << " tried to interact while dead; ignoring." << std::endl;
 976                 if (pointed.type == POINTEDTHING_NODE) {
 977                         // Re-send block to revert change on client-side
 978                         RemoteClient *client = getClient(peer_id);
 979                         v3s16 blockpos = getNodeBlockPos(pointed.node_undersurface);
 980                         client->SetBlockNotSent(blockpos);
 981                 }
 982                 // Call callbacks
 983                 m_script->on_cheat(playersao, "interacted_while_dead");
 984                 return;
 985         }
 986
 987         process_PlayerPos(player, playersao, pkt);
 988
 989         v3f player_pos = playersao->getLastGoodPosition();
 990
 991         // Update wielded item
 992
 993         if (item_i >= player->getHotbarItemcount()) {
 994                 actionstream << "Player: " << player->getName()
 995                         << " tried to access item=" << item_i
 996                         << " out of hotbar_itemcount="
 997                         << player->getHotbarItemcount()
 998                         << "; ignoring." << std::endl;
 999                 return;
1000         }
1001
1002         playersao->getPlayer()->setWieldIndex(item_i);
1003
1004         // Get pointed to object (NULL if not POINTEDTYPE_OBJECT)
1005         ServerActiveObject *pointed_object = NULL;
1006         if (pointed.type == POINTEDTHING_OBJECT) {
1007                 pointed_object = m_env->getActiveObject(pointed.object_id);
1008                 if (pointed_object == NULL) {
1009                         verbosestream << "TOSERVER_INTERACT: "
1010                                 "pointed object is NULL" << std::endl;
1011                         return;
1012                 }
1013
1014         }
1015
1016         /*
1017                 Make sure the player is allowed to do it
1018         */
1019         if (!checkPriv(player->getName(), "interact")) {
1020                 actionstream << player->getName() << " attempted to interact with " <<
1021                                 pointed.dump() << " without 'interact' privilege" << std::endl;
1022
1023                 if (pointed.type != POINTEDTHING_NODE)
1024                         return;
1025
1026                 // Re-send block to revert change on client-side
1027                 RemoteClient *client = getClient(peer_id);
1028                 // Digging completed -> under
1029                 if (action == INTERACT_DIGGING_COMPLETED) {
1030                         v3s16 blockpos = getNodeBlockPos(pointed.node_undersurface);
1031                         client->SetBlockNotSent(blockpos);
1032                 }
1033                 // Placement -> above
1034                 else if (action == INTERACT_PLACE) {
1035                         v3s16 blockpos = getNodeBlockPos(pointed.node_abovesurface);
1036                         client->SetBlockNotSent(blockpos);
1037                 }
1038                 return;
1039         }
1040
1041         /*
1042                 Check that target is reasonably close
1043         */
1044         static thread_local const bool enable_anticheat =
1045                         !g_settings->getBool("disable_anticheat");
1046
1047         if ((action == INTERACT_START_DIGGING || action == INTERACT_DIGGING_COMPLETED ||
1048                         action == INTERACT_PLACE || action == INTERACT_USE) &&
1049                         enable_anticheat && !isSingleplayer()) {
1050                 v3f target_pos = player_pos;
1051                 if (pointed.type == POINTEDTHING_NODE) {
1052                         target_pos = intToFloat(pointed.node_undersurface, BS);
1053                 } else if (pointed.type == POINTEDTHING_OBJECT) {
1054                         if (playersao->getId() == pointed_object->getId()) {
1055                                 actionstream << "Server: " << player->getName()
1056                                         << " attempted to interact with themselves" << std::endl;
1057                                 m_script->on_cheat(playersao, "interacted_with_self");
1058                                 return;
1059                         }
1060                         target_pos = pointed_object->getBasePosition();
1061                 }
1062                 float d = playersao->getEyePosition().getDistanceFrom(target_pos);
1063
1064                 if (!checkInteractDistance(player, d, pointed.dump())) {
1065                         if (pointed.type == POINTEDTHING_NODE) {
1066                                 // Re-send block to revert change on client-side
1067                                 RemoteClient *client = getClient(peer_id);
1068                                 v3s16 blockpos = getNodeBlockPos(pointed.node_undersurface);
1069                                 client->SetBlockNotSent(blockpos);
1070                         }
1071                         return;
1072                 }
1073         }
1074
1075         /*
1076                 If something goes wrong, this player is to blame
1077         */
1078         RollbackScopeActor rollback_scope(m_rollback,
1079                         std::string("player:")+player->getName());
1080
1081         switch (action) {
1082         // Start digging or punch object
1083         case INTERACT_START_DIGGING: {
1084                 if (pointed.type == POINTEDTHING_NODE) {
1085                         MapNode n(CONTENT_IGNORE);
1086                         bool pos_ok;
1087
1088                         v3s16 p_under = pointed.node_undersurface;
1089                         n = m_env->getMap().getNode(p_under, &pos_ok);
1090                         if (!pos_ok) {
1091                                 infostream << "Server: Not punching: Node not found. "
1092                                         "Adding block to emerge queue." << std::endl;
1093                                 m_emerge->enqueueBlockEmerge(peer_id,
1094                                         getNodeBlockPos(pointed.node_abovesurface), false);
1095                         }
1096
1097                         if (n.getContent() != CONTENT_IGNORE)
1098                                 m_script->node_on_punch(p_under, n, playersao, pointed);
1099
1100                         // Cheat prevention
1101                         playersao->noCheatDigStart(p_under);
1102
1103                         return;
1104                 }
1105
1106                 // Skip if the object can't be interacted with anymore
1107                 if (pointed.type != POINTEDTHING_OBJECT || pointed_object->isGone())
1108                         return;
1109
1110                 ItemStack selected_item, hand_item;
1111                 ItemStack tool_item = playersao->getWieldedItem(&selected_item, &hand_item);
1112                 ToolCapabilities toolcap =
1113                                 tool_item.getToolCapabilities(m_itemdef);
1114                 v3f dir = (pointed_object->getBasePosition() -
1115                                 (playersao->getBasePosition() + playersao->getEyeOffset())
1116                                         ).normalize();
1117                 float time_from_last_punch =
1118                         playersao->resetTimeFromLastPunch();
1119
1120                 u16 src_original_hp = pointed_object->getHP();
1121                 u16 dst_origin_hp = playersao->getHP();
1122
1123                 u16 wear = pointed_object->punch(dir, &toolcap, playersao,
1124                                 time_from_last_punch);
1125
1126                 // Callback may have changed item, so get it again
1127                 playersao->getWieldedItem(&selected_item);
1128                 bool changed = selected_item.addWear(wear, m_itemdef);
1129                 if (changed)
1130                         playersao->setWieldedItem(selected_item);
1131
1132                 // If the object is a player and its HP changed
1133                 if (src_original_hp != pointed_object->getHP() &&
1134                                 pointed_object->getType() == ACTIVEOBJECT_TYPE_PLAYER) {
1135                         SendPlayerHPOrDie((PlayerSAO *)pointed_object,
1136                                         PlayerHPChangeReason(PlayerHPChangeReason::PLAYER_PUNCH, playersao));
1137                 }
1138
1139                 // If the puncher is a player and its HP changed
1140                 if (dst_origin_hp != playersao->getHP())
1141                         SendPlayerHPOrDie(playersao,
1142                                         PlayerHPChangeReason(PlayerHPChangeReason::PLAYER_PUNCH, pointed_object));
1143
1144                 return;
1145         } // action == INTERACT_START_DIGGING
1146
1147         case INTERACT_STOP_DIGGING:
1148                 // Nothing to do
1149                 return;
1150
1151         case INTERACT_DIGGING_COMPLETED: {
1152                 // Only digging of nodes
1153                 if (pointed.type != POINTEDTHING_NODE)
1154                         return;
1155                 bool pos_ok;
1156                 v3s16 p_under = pointed.node_undersurface;
1157                 MapNode n = m_env->getMap().getNode(p_under, &pos_ok);
1158                 if (!pos_ok) {
1159                         infostream << "Server: Not finishing digging: Node not found. "
1160                                 "Adding block to emerge queue." << std::endl;
1161                         m_emerge->enqueueBlockEmerge(peer_id,
1162                                 getNodeBlockPos(pointed.node_abovesurface), false);
1163                 }
1164
1165                 /* Cheat prevention */
1166                 bool is_valid_dig = true;
1167                 if (enable_anticheat && !isSingleplayer()) {
1168                         v3s16 nocheat_p = playersao->getNoCheatDigPos();
1169                         float nocheat_t = playersao->getNoCheatDigTime();
1170                         playersao->noCheatDigEnd();
1171                         // If player didn't start digging this, ignore dig
1172                         if (nocheat_p != p_under) {
1173                                 infostream << "Server: " << player->getName()
1174                                                 << " started digging "
1175                                                 << PP(nocheat_p) << " and completed digging "
1176                                                 << PP(p_under) << "; not digging." << std::endl;
1177                                 is_valid_dig = false;
1178                                 // Call callbacks
1179                                 m_script->on_cheat(playersao, "finished_unknown_dig");
1180                         }
1181
1182                         // Get player's wielded item
1183                         // See also: Game::handleDigging
1184                         ItemStack selected_item, hand_item;
1185                         playersao->getPlayer()->getWieldedItem(&selected_item, &hand_item);
1186
1187                         // Get diggability and expected digging time
1188                         DigParams params = getDigParams(m_nodedef->get(n).groups,
1189                                         &selected_item.getToolCapabilities(m_itemdef));
1190                         // If can't dig, try hand
1191                         if (!params.diggable) {
1192                                 params = getDigParams(m_nodedef->get(n).groups,
1193                                         &hand_item.getToolCapabilities(m_itemdef));
1194                         }
1195                         // If can't dig, ignore dig
1196                         if (!params.diggable) {
1197                                 infostream << "Server: " << player->getName()
1198                                                 << " completed digging " << PP(p_under)
1199                                                 << ", which is not diggable with tool; not digging."
1200                                                 << std::endl;
1201                                 is_valid_dig = false;
1202                                 // Call callbacks
1203                                 m_script->on_cheat(playersao, "dug_unbreakable");
1204                         }
1205                         // Check digging time
1206                         // If already invalidated, we don't have to
1207                         if (!is_valid_dig) {
1208                                 // Well not our problem then
1209                         }
1210                         // Clean and long dig
1211                         else if (params.time > 2.0 && nocheat_t * 1.2 > params.time) {
1212                                 // All is good, but grab time from pool; don't care if
1213                                 // it's actually available
1214                                 playersao->getDigPool().grab(params.time);
1215                         }
1216                         // Short or laggy dig
1217                         // Try getting the time from pool
1218                         else if (playersao->getDigPool().grab(params.time)) {
1219                                 // All is good
1220                         }
1221                         // Dig not possible
1222                         else {
1223                                 infostream << "Server: " << player->getName()
1224                                                 << " completed digging " << PP(p_under)
1225                                                 << "too fast; not digging." << std::endl;
1226                                 is_valid_dig = false;
1227                                 // Call callbacks
1228                                 m_script->on_cheat(playersao, "dug_too_fast");
1229                         }
1230                 }
1231
1232                 /* Actually dig node */
1233
1234                 if (is_valid_dig && n.getContent() != CONTENT_IGNORE)
1235                         m_script->node_on_dig(p_under, n, playersao);
1236
1237                 v3s16 blockpos = getNodeBlockPos(p_under);
1238                 RemoteClient *client = getClient(peer_id);
1239                 // Send unusual result (that is, node not being removed)
1240                 if (m_env->getMap().getNode(p_under).getContent() != CONTENT_AIR)
1241                         // Re-send block to revert change on client-side
1242                         client->SetBlockNotSent(blockpos);
1243                 else
1244                         client->ResendBlockIfOnWire(blockpos);
1245
1246                 return;
1247         } // action == INTERACT_DIGGING_COMPLETED
1248
1249         // Place block or right-click object
1250         case INTERACT_PLACE: {
1251                 ItemStack selected_item;
1252                 playersao->getWieldedItem(&selected_item, nullptr);
1253
1254                 // Reset build time counter
1255                 if (pointed.type == POINTEDTHING_NODE &&
1256                                 selected_item.getDefinition(m_itemdef).type == ITEM_NODE)
1257                         getClient(peer_id)->m_time_from_building = 0.0;
1258
1259                 if (pointed.type == POINTEDTHING_OBJECT) {
1260                         // Right click object
1261
1262                         // Skip if object can't be interacted with anymore
1263                         if (pointed_object->isGone())
1264                                 return;
1265
1266                         actionstream << player->getName() << " right-clicks object "
1267                                         << pointed.object_id << ": "
1268                                         << pointed_object->getDescription() << std::endl;
1269
1270                         // Do stuff
1271                         if (m_script->item_OnSecondaryUse(
1272                                         selected_item, playersao, pointed)) {
1273                                 if (playersao->setWieldedItem(selected_item)) {
1274                                         SendInventory(playersao, true);
1275                                 }
1276                         }
1277
1278                         pointed_object->rightClick(playersao);
1279                 } else if (m_script->item_OnPlace(selected_item, playersao, pointed)) {
1280                         // Placement was handled in lua
1281
1282                         // Apply returned ItemStack
1283                         if (playersao->setWieldedItem(selected_item))
1284                                 SendInventory(playersao, true);
1285                 }
1286
1287                 if (pointed.type != POINTEDTHING_NODE)
1288                         return;
1289
1290                 // If item has node placement prediction, always send the
1291                 // blocks to make sure the client knows what exactly happened
1292                 RemoteClient *client = getClient(peer_id);
1293                 v3s16 blockpos = getNodeBlockPos(pointed.node_abovesurface);
1294                 v3s16 blockpos2 = getNodeBlockPos(pointed.node_undersurface);
1295                 if (!selected_item.getDefinition(m_itemdef
1296                                 ).node_placement_prediction.empty()) {
1297                         client->SetBlockNotSent(blockpos);
1298                         if (blockpos2 != blockpos)
1299                                 client->SetBlockNotSent(blockpos2);
1300                 } else {
1301                         client->ResendBlockIfOnWire(blockpos);
1302                         if (blockpos2 != blockpos)
1303                                 client->ResendBlockIfOnWire(blockpos2);
1304                 }
1305
1306                 return;
1307         } // action == INTERACT_PLACE
1308
1309         case INTERACT_USE: {
1310                 ItemStack selected_item;
1311                 playersao->getWieldedItem(&selected_item, nullptr);
1312
1313                 actionstream << player->getName() << " uses " << selected_item.name
1314                                 << ", pointing at " << pointed.dump() << std::endl;
1315
1316                 if (m_script->item_OnUse(selected_item, playersao, pointed)) {
1317                         // Apply returned ItemStack
1318                         if (playersao->setWieldedItem(selected_item))
1319                                 SendInventory(playersao, true);
1320                 }
1321
1322                 return;
1323         }
1324
1325         // Rightclick air
1326         case INTERACT_ACTIVATE: {
1327                 ItemStack selected_item;
1328                 playersao->getWieldedItem(&selected_item, nullptr);
1329
1330                 actionstream << player->getName() << " activates "
1331                                 << selected_item.name << std::endl;
1332
1333                 pointed.type = POINTEDTHING_NOTHING; // can only ever be NOTHING
1334
1335                 if (m_script->item_OnSecondaryUse(selected_item, playersao, pointed)) {
1336                         if (playersao->setWieldedItem(selected_item))
1337                                 SendInventory(playersao, true);
1338                 }
1339
1340                 return;
1341         }
1342
1343         default:
1344                 warningstream << "Server: Invalid action " << action << std::endl;
1345
1346         }
1347 }
1348
1349 void Server::handleCommand_RemovedSounds(NetworkPacket* pkt)
1350 {
1351         u16 num;
1352         *pkt >> num;
1353         for (u16 k = 0; k < num; k++) {
1354                 s32 id;
1355
1356                 *pkt >> id;
1357
1358                 std::unordered_map<s32, ServerPlayingSound>::iterator i =
1359                         m_playing_sounds.find(id);
1360                 if (i == m_playing_sounds.end())
1361                         continue;
1362
1363                 ServerPlayingSound &psound = i->second;
1364                 psound.clients.erase(pkt->getPeerId());
1365                 if (psound.clients.empty())
1366                         m_playing_sounds.erase(i++);
1367         }
1368 }
1369
1370 void Server::handleCommand_NodeMetaFields(NetworkPacket* pkt)
1371 {
1372         v3s16 p;
1373         std::string formname;
1374         u16 num;
1375
1376         *pkt >> p >> formname >> num;
1377
1378         StringMap fields;
1379         for (u16 k = 0; k < num; k++) {
1380                 std::string fieldname;
1381                 *pkt >> fieldname;
1382                 fields[fieldname] = pkt->readLongString();
1383         }
1384
1385         session_t peer_id = pkt->getPeerId();
1386         RemotePlayer *player = m_env->getPlayer(peer_id);
1387
1388         if (player == NULL) {
1389                 errorstream <<
1390                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
1391                         peer_id << " disconnecting peer!" << std::endl;
1392                 DisconnectPeer(peer_id);
1393                 return;
1394         }
1395
1396         PlayerSAO *playersao = player->getPlayerSAO();
1397         if (playersao == NULL) {
1398                 errorstream <<
1399                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
1400                         peer_id << " disconnecting peer!" << std::endl;
1401                 DisconnectPeer(peer_id);
1402                 return;
1403         }
1404
1405         // If something goes wrong, this player is to blame
1406         RollbackScopeActor rollback_scope(m_rollback,
1407                         std::string("player:")+player->getName());
1408
1409         // Check the target node for rollback data; leave others unnoticed
1410         RollbackNode rn_old(&m_env->getMap(), p, this);
1411
1412         m_script->node_on_receive_fields(p, formname, fields, playersao);
1413
1414         // Report rollback data
1415         RollbackNode rn_new(&m_env->getMap(), p, this);
1416         if (rollback() && rn_new != rn_old) {
1417                 RollbackAction action;
1418                 action.setSetNode(p, rn_old, rn_new);
1419                 rollback()->reportAction(action);
1420         }
1421 }
1422
1423 void Server::handleCommand_InventoryFields(NetworkPacket* pkt)
1424 {
1425         std::string client_formspec_name;
1426         u16 num;
1427
1428         *pkt >> client_formspec_name >> num;
1429
1430         StringMap fields;
1431         for (u16 k = 0; k < num; k++) {
1432                 std::string fieldname;
1433                 *pkt >> fieldname;
1434                 fields[fieldname] = pkt->readLongString();
1435         }
1436
1437         session_t peer_id = pkt->getPeerId();
1438         RemotePlayer *player = m_env->getPlayer(peer_id);
1439
1440         if (player == NULL) {
1441                 errorstream <<
1442                         "Server::ProcessData(): Canceling: No player for peer_id=" <<
1443                         peer_id << " disconnecting peer!" << std::endl;
1444                 DisconnectPeer(peer_id);
1445                 return;
1446         }
1447
1448         PlayerSAO *playersao = player->getPlayerSAO();
1449         if (playersao == NULL) {
1450                 errorstream <<
1451                         "Server::ProcessData(): Canceling: No player object for peer_id=" <<
1452                         peer_id << " disconnecting peer!" << std::endl;
1453                 DisconnectPeer(peer_id);
1454                 return;
1455         }
1456
1457         if (client_formspec_name.empty()) { // pass through inventory submits
1458                 m_script->on_playerReceiveFields(playersao, client_formspec_name, fields);
1459                 return;
1460         }
1461
1462         // verify that we displayed the formspec to the user
1463         const auto peer_state_iterator = m_formspec_state_data.find(peer_id);
1464         if (peer_state_iterator != m_formspec_state_data.end()) {
1465                 const std::string &server_formspec_name = peer_state_iterator->second;
1466                 if (client_formspec_name == server_formspec_name) {
1467                         auto it = fields.find("quit");
1468                         if (it != fields.end() && it->second == "true")
1469                                 m_formspec_state_data.erase(peer_state_iterator);
1470
1471                         m_script->on_playerReceiveFields(playersao, client_formspec_name, fields);
1472                         return;
1473                 }
1474                 actionstream << "'" << player->getName()
1475                         << "' submitted formspec ('" << client_formspec_name
1476                         << "') but the name of the formspec doesn't match the"
1477                         " expected name ('" << server_formspec_name << "')";
1478
1479         } else {
1480                 actionstream << "'" << player->getName()
1481                         << "' submitted formspec ('" << client_formspec_name
1482                         << "') but server hasn't sent formspec to client";
1483         }
1484         actionstream << ", possible exploitation attempt" << std::endl;
1485 }
1486
1487 void Server::handleCommand_FirstSrp(NetworkPacket* pkt)
1488 {
1489         session_t peer_id = pkt->getPeerId();
1490         RemoteClient *client = getClient(peer_id, CS_Invalid);
1491         ClientState cstate = client->getState();
1492
1493         std::string playername = client->getName();
1494
1495         std::string salt;
1496         std::string verification_key;
1497
1498         std::string addr_s = getPeerAddress(peer_id).serializeString();
1499         u8 is_empty;
1500
1501         *pkt >> salt >> verification_key >> is_empty;
1502
1503         verbosestream << "Server: Got TOSERVER_FIRST_SRP from " << addr_s
1504                 << ", with is_empty=" << (is_empty == 1) << std::endl;
1505
1506         // Either this packet is sent because the user is new or to change the password
1507         if (cstate == CS_HelloSent) {
1508                 if (!client->isMechAllowed(AUTH_MECHANISM_FIRST_SRP)) {
1509                         actionstream << "Server: Client from " << addr_s
1510                                         << " tried to set password without being "
1511                                         << "authenticated, or the username being new." << std::endl;
1512                         DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1513                         return;
1514                 }
1515
1516                 if (!isSingleplayer() &&
1517                                 g_settings->getBool("disallow_empty_password") &&
1518                                 is_empty == 1) {
1519                         actionstream << "Server: " << playername
1520                                         << " supplied empty password from " << addr_s << std::endl;
1521                         DenyAccess(peer_id, SERVER_ACCESSDENIED_EMPTY_PASSWORD);
1522                         return;
1523                 }
1524
1525                 std::string initial_ver_key;
1526
1527                 initial_ver_key = encode_srp_verifier(verification_key, salt);
1528                 m_script->createAuth(playername, initial_ver_key);
1529                 m_script->on_authplayer(playername, addr_s, true);
1530
1531                 acceptAuth(peer_id, false);
1532         } else {
1533                 if (cstate < CS_SudoMode) {
1534                         infostream << "Server::ProcessData(): Ignoring TOSERVER_FIRST_SRP from "
1535                                         << addr_s << ": " << "Client has wrong state " << cstate << "."
1536                                         << std::endl;
1537                         return;
1538                 }
1539                 m_clients.event(peer_id, CSE_SudoLeave);
1540                 std::string pw_db_field = encode_srp_verifier(verification_key, salt);
1541                 bool success = m_script->setPassword(playername, pw_db_field);
1542                 if (success) {
1543                         actionstream << playername << " changes password" << std::endl;
1544                         SendChatMessage(peer_id, ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
1545                                 L"Password change successful."));
1546                 } else {
1547                         actionstream << playername <<
1548                                 " tries to change password but it fails" << std::endl;
1549                         SendChatMessage(peer_id, ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
1550                                 L"Password change failed or unavailable."));
1551                 }
1552         }
1553 }
1554
1555 void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
1556 {
1557         session_t peer_id = pkt->getPeerId();
1558         RemoteClient *client = getClient(peer_id, CS_Invalid);
1559         ClientState cstate = client->getState();
1560
1561         bool wantSudo = (cstate == CS_Active);
1562
1563         if (!((cstate == CS_HelloSent) || (cstate == CS_Active))) {
1564                 actionstream << "Server: got SRP _A packet in wrong state " << cstate <<
1565                         " from " << getPeerAddress(peer_id).serializeString() <<
1566                         ". Ignoring." << std::endl;
1567                 return;
1568         }
1569
1570         if (client->chosen_mech != AUTH_MECHANISM_NONE) {
1571                 actionstream << "Server: got SRP _A packet, while auth is already "
1572                         "going on with mech " << client->chosen_mech << " from " <<
1573                         getPeerAddress(peer_id).serializeString() <<
1574                         " (wantSudo=" << wantSudo << "). Ignoring." << std::endl;
1575                 if (wantSudo) {
1576                         DenySudoAccess(peer_id);
1577                         return;
1578                 }
1579
1580                 DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1581                 return;
1582         }
1583
1584         std::string bytes_A;
1585         u8 based_on;
1586         *pkt >> bytes_A >> based_on;
1587
1588         infostream << "Server: TOSERVER_SRP_BYTES_A received with "
1589                 << "based_on=" << int(based_on) << " and len_A="
1590                 << bytes_A.length() << "." << std::endl;
1591
1592         AuthMechanism chosen = (based_on == 0) ?
1593                 AUTH_MECHANISM_LEGACY_PASSWORD : AUTH_MECHANISM_SRP;
1594
1595         if (wantSudo) {
1596                 if (!client->isSudoMechAllowed(chosen)) {
1597                         actionstream << "Server: Player \"" << client->getName() <<
1598                                 "\" at " << getPeerAddress(peer_id).serializeString() <<
1599                                 " tried to change password using unallowed mech " << chosen <<
1600                                 "." << std::endl;
1601                         DenySudoAccess(peer_id);
1602                         return;
1603                 }
1604         } else {
1605                 if (!client->isMechAllowed(chosen)) {
1606                         actionstream << "Server: Client tried to authenticate from " <<
1607                                 getPeerAddress(peer_id).serializeString() <<
1608                                 " using unallowed mech " << chosen << "." << std::endl;
1609                         DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1610                         return;
1611                 }
1612         }
1613
1614         client->chosen_mech = chosen;
1615
1616         std::string salt;
1617         std::string verifier;
1618
1619         if (based_on == 0) {
1620
1621                 generate_srp_verifier_and_salt(client->getName(), client->enc_pwd,
1622                         &verifier, &salt);
1623         } else if (!decode_srp_verifier_and_salt(client->enc_pwd, &verifier, &salt)) {
1624                 // Non-base64 errors should have been catched in the init handler
1625                 actionstream << "Server: User " << client->getName() <<
1626                         " tried to log in, but srp verifier field was invalid (most likely "
1627                         "invalid base64)." << std::endl;
1628                 DenyAccess(peer_id, SERVER_ACCESSDENIED_SERVER_FAIL);
1629                 return;
1630         }
1631
1632         char *bytes_B = 0;
1633         size_t len_B = 0;
1634
1635         client->auth_data = srp_verifier_new(SRP_SHA256, SRP_NG_2048,
1636                 client->getName().c_str(),
1637                 (const unsigned char *) salt.c_str(), salt.size(),
1638                 (const unsigned char *) verifier.c_str(), verifier.size(),
1639                 (const unsigned char *) bytes_A.c_str(), bytes_A.size(),
1640                 NULL, 0,
1641                 (unsigned char **) &bytes_B, &len_B, NULL, NULL);
1642
1643         if (!bytes_B) {
1644                 actionstream << "Server: User " << client->getName()
1645                         << " tried to log in, SRP-6a safety check violated in _A handler."
1646                         << std::endl;
1647                 if (wantSudo) {
1648                         DenySudoAccess(peer_id);
1649                         return;
1650                 }
1651
1652                 DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1653                 return;
1654         }
1655
1656         NetworkPacket resp_pkt(TOCLIENT_SRP_BYTES_S_B, 0, peer_id);
1657         resp_pkt << salt << std::string(bytes_B, len_B);
1658         Send(&resp_pkt);
1659 }
1660
1661 void Server::handleCommand_SrpBytesM(NetworkPacket* pkt)
1662 {
1663         session_t peer_id = pkt->getPeerId();
1664         RemoteClient *client = getClient(peer_id, CS_Invalid);
1665         ClientState cstate = client->getState();
1666         std::string addr_s = getPeerAddress(pkt->getPeerId()).serializeString();
1667         std::string playername = client->getName();
1668
1669         bool wantSudo = (cstate == CS_Active);
1670
1671         verbosestream << "Server: Received TOSERVER_SRP_BYTES_M." << std::endl;
1672
1673         if (!((cstate == CS_HelloSent) || (cstate == CS_Active))) {
1674                 warningstream << "Server: got SRP_M packet in wrong state "
1675                         << cstate << " from " << addr_s << ". Ignoring." << std::endl;
1676                 return;
1677         }
1678
1679         if (client->chosen_mech != AUTH_MECHANISM_SRP &&
1680                         client->chosen_mech != AUTH_MECHANISM_LEGACY_PASSWORD) {
1681                 warningstream << "Server: got SRP_M packet, while auth "
1682                         "is going on with mech " << client->chosen_mech << " from "
1683                         << addr_s << " (wantSudo=" << wantSudo << "). Denying." << std::endl;
1684                 if (wantSudo) {
1685                         DenySudoAccess(peer_id);
1686                         return;
1687                 }
1688
1689                 DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1690                 return;
1691         }
1692
1693         std::string bytes_M;
1694         *pkt >> bytes_M;
1695
1696         if (srp_verifier_get_session_key_length((SRPVerifier *) client->auth_data)
1697                         != bytes_M.size()) {
1698                 actionstream << "Server: User " << playername << " at " << addr_s
1699                         << " sent bytes_M with invalid length " << bytes_M.size() << std::endl;
1700                 DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1701                 return;
1702         }
1703
1704         unsigned char *bytes_HAMK = 0;
1705
1706         srp_verifier_verify_session((SRPVerifier *) client->auth_data,
1707                 (unsigned char *)bytes_M.c_str(), &bytes_HAMK);
1708
1709         if (!bytes_HAMK) {
1710                 if (wantSudo) {
1711                         actionstream << "Server: User " << playername << " at " << addr_s
1712                                 << " tried to change their password, but supplied wrong"
1713                                 << " (SRP) password for authentication." << std::endl;
1714                         DenySudoAccess(peer_id);
1715                         return;
1716                 }
1717
1718                 actionstream << "Server: User " << playername << " at " << addr_s
1719                         << " supplied wrong password (auth mechanism: SRP)." << std::endl;
1720                 m_script->on_authplayer(playername, addr_s, false);
1721                 DenyAccess(peer_id, SERVER_ACCESSDENIED_WRONG_PASSWORD);
1722                 return;
1723         }
1724
1725         if (client->create_player_on_auth_success) {
1726                 m_script->createAuth(playername, client->enc_pwd);
1727
1728                 std::string checkpwd; // not used, but needed for passing something
1729                 if (!m_script->getAuth(playername, &checkpwd, NULL)) {
1730                         errorstream << "Server: " << playername <<
1731                                 " cannot be authenticated (auth handler does not work?)" <<
1732                                 std::endl;
1733                         DenyAccess(peer_id, SERVER_ACCESSDENIED_SERVER_FAIL);
1734                         return;
1735                 }
1736                 client->create_player_on_auth_success = false;
1737         }
1738
1739         m_script->on_authplayer(playername, addr_s, true);
1740         acceptAuth(peer_id, wantSudo);
1741 }
1742
1743 /*
1744  * Mod channels
1745  */
1746
1747 void Server::handleCommand_ModChannelJoin(NetworkPacket *pkt)
1748 {
1749         std::string channel_name;
1750         *pkt >> channel_name;
1751
1752         session_t peer_id = pkt->getPeerId();
1753         NetworkPacket resp_pkt(TOCLIENT_MODCHANNEL_SIGNAL,
1754                 1 + 2 + channel_name.size(), peer_id);
1755
1756         // Send signal to client to notify join succeed or not
1757         if (g_settings->getBool("enable_mod_channels") &&
1758                         m_modchannel_mgr->joinChannel(channel_name, peer_id)) {
1759                 resp_pkt << (u8) MODCHANNEL_SIGNAL_JOIN_OK;
1760                 infostream << "Peer " << peer_id << " joined channel " <<
1761                         channel_name << std::endl;
1762         }
1763         else {
1764                 resp_pkt << (u8)MODCHANNEL_SIGNAL_JOIN_FAILURE;
1765                 infostream << "Peer " << peer_id << " tried to join channel " <<
1766                         channel_name << ", but was already registered." << std::endl;
1767         }
1768         resp_pkt << channel_name;
1769         Send(&resp_pkt);
1770 }
1771
1772 void Server::handleCommand_ModChannelLeave(NetworkPacket *pkt)
1773 {
1774         std::string channel_name;
1775         *pkt >> channel_name;
1776
1777         session_t peer_id = pkt->getPeerId();
1778         NetworkPacket resp_pkt(TOCLIENT_MODCHANNEL_SIGNAL,
1779                 1 + 2 + channel_name.size(), peer_id);
1780
1781         // Send signal to client to notify join succeed or not
1782         if (g_settings->getBool("enable_mod_channels") &&
1783                         m_modchannel_mgr->leaveChannel(channel_name, peer_id)) {
1784                 resp_pkt << (u8)MODCHANNEL_SIGNAL_LEAVE_OK;
1785                 infostream << "Peer " << peer_id << " left channel " << channel_name <<
1786                         std::endl;
1787         } else {
1788                 resp_pkt << (u8) MODCHANNEL_SIGNAL_LEAVE_FAILURE;
1789                 infostream << "Peer " << peer_id << " left channel " << channel_name <<
1790                         ", but was not registered." << std::endl;
1791         }
1792         resp_pkt << channel_name;
1793         Send(&resp_pkt);
1794 }
1795
1796 void Server::handleCommand_ModChannelMsg(NetworkPacket *pkt)
1797 {
1798         std::string channel_name, channel_msg;
1799         *pkt >> channel_name >> channel_msg;
1800
1801         session_t peer_id = pkt->getPeerId();
1802         verbosestream << "Mod channel message received from peer " << peer_id <<
1803                 " on channel " << channel_name << " message: " << channel_msg <<
1804                 std::endl;
1805
1806         // If mod channels are not enabled, discard message
1807         if (!g_settings->getBool("enable_mod_channels")) {
1808                 return;
1809         }
1810
1811         // If channel not registered, signal it and ignore message
1812         if (!m_modchannel_mgr->channelRegistered(channel_name)) {
1813                 NetworkPacket resp_pkt(TOCLIENT_MODCHANNEL_SIGNAL,
1814                         1 + 2 + channel_name.size(), peer_id);
1815                 resp_pkt << (u8)MODCHANNEL_SIGNAL_CHANNEL_NOT_REGISTERED << channel_name;
1816                 Send(&resp_pkt);
1817                 return;
1818         }
1819
1820         // @TODO: filter, rate limit
1821
1822         broadcastModChannelMessage(channel_name, channel_msg, peer_id);
1823 }