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 "content_sao.h"
  24 #include "emerge.h"
  25 #include "mapblock.h"
  26 #include "modchannels.h"
  27 #include "nodedef.h"
  28 #include "remoteplayer.h"
  29 #include "rollback_interface.h"
  30 #include "scripting_server.h"
  31 #include "settings.h"
  32 #include "tool.h"
  33 #include "version.h"
  34 #include "network/connection.h"
  35 #include "network/networkprotocol.h"
  36 #include "network/serveropcodes.h"
  37 #include "util/auth.h"
  38 #include "util/base64.h"
  39 #include "util/pointedthing.h"
  40 #include "util/serialize.h"
  41 #include "util/srp.h"
  42
  43 void Server::handleCommand_Deprecated(NetworkPacket* pkt)
  44 {
  45         infostream << "Server: " << toServerCommandTable[pkt->getCommand()].name
  46                 << " not supported anymore" << std::endl;
  47 }
  48
  49 void Server::handleCommand_Init(NetworkPacket* pkt)
  50 {
  51
  52         if(pkt->getSize() < 1)
  53                 return;
  54
  55         RemoteClient* client = getClient(pkt->getPeerId(), CS_Created);
  56
  57         std::string addr_s;
  58         try {
  59                 Address address = getPeerAddress(pkt->getPeerId());
  60                 addr_s = address.serializeString();
  61         }
  62         catch (con::PeerNotFoundException &e) {
  63                 /*
  64                  * no peer for this packet found
  65                  * most common reason is peer timeout, e.g. peer didn't
  66                  * respond for some time, your server was overloaded or
  67                  * things like that.
  68                  */
  69                 infostream << "Server::ProcessData(): Canceling: peer "
  70                                 << pkt->getPeerId() << " not found" << std::endl;
  71                 return;
  72         }
  73
  74         // If net_proto_version is set, this client has already been handled
  75         if (client->getState() > CS_Created) {
  76                 verbosestream << "Server: Ignoring multiple TOSERVER_INITs from "
  77                                 << addr_s << " (peer_id=" << pkt->getPeerId() << ")" << std::endl;
  78                 return;
  79         }
  80
  81         verbosestream << "Server: Got TOSERVER_INIT from " << addr_s << " (peer_id="
  82                         << pkt->getPeerId() << ")" << std::endl;
  83
  84         // Do not allow multiple players in simple singleplayer mode.
  85         // This isn't a perfect way to do it, but will suffice for now
  86         if (m_simple_singleplayer_mode && m_clients.getClientIDs().size() > 1) {
  87                 infostream << "Server: Not allowing another client (" << addr_s
  88                                 << ") to connect in simple singleplayer mode" << std::endl;
  89                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_SINGLEPLAYER);
  90                 return;
  91         }
  92
  93         // First byte after command is maximum supported
  94         // serialization version
  95         u8 client_max;
  96         u16 supp_compr_modes;
  97         u16 min_net_proto_version = 0;
  98         u16 max_net_proto_version;
  99         std::string playerName;
 100
 101         *pkt >> client_max >> supp_compr_modes >> min_net_proto_version
 102                         >> max_net_proto_version >> playerName;
 103
 104         u8 our_max = SER_FMT_VER_HIGHEST_READ;
 105         // Use the highest version supported by both
 106         u8 depl_serial_v = std::min(client_max, our_max);
 107         // If it's lower than the lowest supported, give up.
 108         if (depl_serial_v < SER_FMT_VER_LOWEST_READ)
 109                 depl_serial_v = SER_FMT_VER_INVALID;
 110
 111         if (depl_serial_v == SER_FMT_VER_INVALID) {
 112                 actionstream << "Server: A mismatched client tried to connect from "
 113                                 << addr_s << std::endl;
 114                 infostream<<"Server: Cannot negotiate serialization version with "
 115                                 << addr_s << std::endl;
 116                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_WRONG_VERSION);
 117                 return;
 118         }
 119
 120         client->setPendingSerializationVersion(depl_serial_v);
 121
 122         /*
 123                 Read and check network protocol version
 124         */
 125
 126         u16 net_proto_version = 0;
 127
 128         // Figure out a working version if it is possible at all
 129         if (max_net_proto_version >= SERVER_PROTOCOL_VERSION_MIN ||
 130                         min_net_proto_version <= SERVER_PROTOCOL_VERSION_MAX) {
 131                 // If maximum is larger than our maximum, go with our maximum
 132                 if (max_net_proto_version > SERVER_PROTOCOL_VERSION_MAX)
 133                         net_proto_version = SERVER_PROTOCOL_VERSION_MAX;
 134                 // Else go with client's maximum
 135                 else
 136                         net_proto_version = max_net_proto_version;
 137         }
 138
 139         verbosestream << "Server: " << addr_s << ": Protocol version: min: "
 140                         << min_net_proto_version << ", max: " << max_net_proto_version
 141                         << ", chosen: " << net_proto_version << std::endl;
 142
 143         client->net_proto_version = net_proto_version;
 144
 145         if ((g_settings->getBool("strict_protocol_version_checking") &&
 146                         net_proto_version != LATEST_PROTOCOL_VERSION) ||
 147                         net_proto_version < SERVER_PROTOCOL_VERSION_MIN ||
 148                         net_proto_version > SERVER_PROTOCOL_VERSION_MAX) {
 149                 actionstream << "Server: A mismatched client tried to connect from "
 150                                 << addr_s << std::endl;
 151                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_WRONG_VERSION);
 152                 return;
 153         }
 154
 155         /*
 156                 Validate player name
 157         */
 158         const char* playername = playerName.c_str();
 159
 160         size_t pns = playerName.size();
 161         if (pns == 0 || pns > PLAYERNAME_SIZE) {
 162                 actionstream << "Server: Player with "
 163                         << ((pns > PLAYERNAME_SIZE) ? "a too long" : "an empty")
 164                         << " name tried to connect from " << addr_s << std::endl;
 165                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_WRONG_NAME);
 166                 return;
 167         }
 168
 169         if (!string_allowed(playerName, PLAYERNAME_ALLOWED_CHARS)) {
 170                 actionstream << "Server: Player with an invalid name "
 171                                 << "tried to connect from " << addr_s << std::endl;
 172                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_WRONG_CHARS_IN_NAME);
 173                 return;
 174         }
 175
 176         m_clients.setPlayerName(pkt->getPeerId(), playername);
 177         //TODO (later) case insensitivity
 178
 179         std::string legacyPlayerNameCasing = playerName;
 180
 181         if (!isSingleplayer() && strcasecmp(playername, "singleplayer") == 0) {
 182                 actionstream << "Server: Player with the name \"singleplayer\" "
 183                                 << "tried to connect from " << addr_s << std::endl;
 184                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_WRONG_NAME);
 185                 return;
 186         }
 187
 188         {
 189                 std::string reason;
 190                 if (m_script->on_prejoinplayer(playername, addr_s, &reason)) {
 191                         actionstream << "Server: Player with the name \"" << playerName << "\" "
 192                                         << "tried to connect from " << addr_s << " "
 193                                         << "but it was disallowed for the following reason: "
 194                                         << reason << std::endl;
 195                         DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_CUSTOM_STRING, reason);
 196                         return;
 197                 }
 198         }
 199
 200         infostream << "Server: New connection: \"" << playerName << "\" from "
 201                         << addr_s << " (peer_id=" << pkt->getPeerId() << ")" << std::endl;
 202
 203         // Enforce user limit.
 204         // Don't enforce for users that have some admin right or mod permits it.
 205         if (m_clients.isUserLimitReached() &&
 206                         playername != g_settings->get("name") &&
 207                         !m_script->can_bypass_userlimit(playername, addr_s)) {
 208                 actionstream << "Server: " << playername << " tried to join from "
 209                                 << addr_s << ", but there" << " are already max_users="
 210                                 << g_settings->getU16("max_users") << " players." << std::endl;
 211                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_TOO_MANY_USERS);
 212                 return;
 213         }
 214
 215         /*
 216                 Compose auth methods for answer
 217         */
 218         std::string encpwd; // encrypted Password field for the user
 219         bool has_auth = m_script->getAuth(playername, &encpwd, NULL);
 220         u32 auth_mechs = 0;
 221
 222         client->chosen_mech = AUTH_MECHANISM_NONE;
 223
 224         if (has_auth) {
 225                 std::vector<std::string> pwd_components = str_split(encpwd, '#');
 226                 if (pwd_components.size() == 4) {
 227                         if (pwd_components[1] == "1") { // 1 means srp
 228                                 auth_mechs |= AUTH_MECHANISM_SRP;
 229                                 client->enc_pwd = encpwd;
 230                         } else {
 231                                 actionstream << "User " << playername
 232                                         << " tried to log in, but password field"
 233                                         << " was invalid (unknown mechcode)." << std::endl;
 234                                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_SERVER_FAIL);
 235                                 return;
 236                         }
 237                 } else if (base64_is_valid(encpwd)) {
 238                         auth_mechs |= AUTH_MECHANISM_LEGACY_PASSWORD;
 239                         client->enc_pwd = encpwd;
 240                 } else {
 241                         actionstream << "User " << playername
 242                                 << " tried to log in, but password field"
 243                                 << " was invalid (invalid base64)." << std::endl;
 244                         DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_SERVER_FAIL);
 245                         return;
 246                 }
 247         } else {
 248                 std::string default_password = g_settings->get("default_password");
 249                 if (default_password.length() == 0) {
 250                         auth_mechs |= AUTH_MECHANISM_FIRST_SRP;
 251                 } else {
 252                         // Take care of default passwords.
 253                         client->enc_pwd = get_encoded_srp_verifier(playerName, default_password);
 254                         auth_mechs |= AUTH_MECHANISM_SRP;
 255                         // Allocate player in db, but only on successful login.
 256                         client->create_player_on_auth_success = true;
 257                 }
 258         }
 259
 260         /*
 261                 Answer with a TOCLIENT_HELLO
 262         */
 263
 264         verbosestream << "Sending TOCLIENT_HELLO with auth method field: "
 265                 << auth_mechs << std::endl;
 266
 267         NetworkPacket resp_pkt(TOCLIENT_HELLO, 1 + 4
 268                 + legacyPlayerNameCasing.size(), pkt->getPeerId());
 269
 270         u16 depl_compress_mode = NETPROTO_COMPRESSION_NONE;
 271         resp_pkt << depl_serial_v << depl_compress_mode << net_proto_version
 272                 << auth_mechs << legacyPlayerNameCasing;
 273
 274         Send(&resp_pkt);
 275
 276         client->allowed_auth_mechs = auth_mechs;
 277         client->setDeployedCompressionMode(depl_compress_mode);
 278
 279         m_clients.event(pkt->getPeerId(), CSE_Hello);
 280 }
 281
 282 void Server::handleCommand_Init2(NetworkPacket* pkt)
 283 {
 284         verbosestream << "Server: Got TOSERVER_INIT2 from "
 285                         << pkt->getPeerId() << std::endl;
 286
 287         m_clients.event(pkt->getPeerId(), CSE_GotInit2);
 288         u16 protocol_version = m_clients.getProtocolVersion(pkt->getPeerId());
 289
 290         std::string lang;
 291         if (pkt->getSize() > 0)
 292                 *pkt >> lang;
 293
 294         /*
 295                 Send some initialization data
 296         */
 297
 298         infostream << "Server: Sending content to "
 299                         << getPlayerName(pkt->getPeerId()) << std::endl;
 300
 301         // Send player movement settings
 302         SendMovement(pkt->getPeerId());
 303
 304         // Send item definitions
 305         SendItemDef(pkt->getPeerId(), m_itemdef, protocol_version);
 306
 307         // Send node definitions
 308         SendNodeDef(pkt->getPeerId(), m_nodedef, protocol_version);
 309
 310         m_clients.event(pkt->getPeerId(), CSE_SetDefinitionsSent);
 311
 312         // Send media announcement
 313         sendMediaAnnouncement(pkt->getPeerId(), lang);
 314
 315         // Send detached inventories
 316         sendDetachedInventories(pkt->getPeerId());
 317
 318         // Send time of day
 319         u16 time = m_env->getTimeOfDay();
 320         float time_speed = g_settings->getFloat("time_speed");
 321         SendTimeOfDay(pkt->getPeerId(), time, time_speed);
 322
 323         SendCSMRestrictionFlags(pkt->getPeerId());
 324
 325         // Warnings about protocol version can be issued here
 326         if (getClient(pkt->getPeerId())->net_proto_version < LATEST_PROTOCOL_VERSION) {
 327                 SendChatMessage(pkt->getPeerId(), ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
 328                                 L"# Server: WARNING: YOUR CLIENT'S VERSION MAY NOT BE FULLY COMPATIBLE "
 329                                 L"WITH THIS SERVER!"));
 330
 331         }
 332 }
 333
 334 void Server::handleCommand_RequestMedia(NetworkPacket* pkt)
 335 {
 336         std::vector<std::string> tosend;
 337         u16 numfiles;
 338
 339         *pkt >> numfiles;
 340
 341         infostream << "Sending " << numfiles << " files to "
 342                         << getPlayerName(pkt->getPeerId()) << std::endl;
 343         verbosestream << "TOSERVER_REQUEST_MEDIA: " << std::endl;
 344
 345         for (u16 i = 0; i < numfiles; i++) {
 346                 std::string name;
 347
 348                 *pkt >> name;
 349
 350                 tosend.push_back(name);
 351                 verbosestream << "TOSERVER_REQUEST_MEDIA: requested file "
 352                                 << name << std::endl;
 353         }
 354
 355         sendRequestedMedia(pkt->getPeerId(), tosend);
 356 }
 357
 358 void Server::handleCommand_ClientReady(NetworkPacket* pkt)
 359 {
 360         session_t peer_id = pkt->getPeerId();
 361
 362         PlayerSAO* playersao = StageTwoClientInit(peer_id);
 363
 364         if (playersao == NULL) {
 365                 actionstream
 366                         << "TOSERVER_CLIENT_READY stage 2 client init failed for peer_id: "
 367                         << peer_id << std::endl;
 368                 DisconnectPeer(peer_id);
 369                 return;
 370         }
 371
 372
 373         if (pkt->getSize() < 8) {
 374                 errorstream
 375                         << "TOSERVER_CLIENT_READY client sent inconsistent data, disconnecting peer_id: "
 376                         << peer_id << std::endl;
 377                 DisconnectPeer(peer_id);
 378                 return;
 379         }
 380
 381         u8 major_ver, minor_ver, patch_ver, reserved;
 382         std::string full_ver;
 383         *pkt >> major_ver >> minor_ver >> patch_ver >> reserved >> full_ver;
 384
 385         m_clients.setClientVersion(
 386                         peer_id, major_ver, minor_ver, patch_ver,
 387                         full_ver);
 388
 389         const std::vector<std::string> &players = m_clients.getPlayerNames();
 390         NetworkPacket list_pkt(TOCLIENT_UPDATE_PLAYER_LIST, 0, peer_id);
 391         list_pkt << (u8) PLAYER_LIST_INIT << (u16) players.size();
 392         for (const std::string &player: players) {
 393                 list_pkt <<  player;
 394         }
 395         m_clients.send(peer_id, 0, &list_pkt, true);
 396
 397         NetworkPacket notice_pkt(TOCLIENT_UPDATE_PLAYER_LIST, 0, PEER_ID_INEXISTENT);
 398         // (u16) 1 + std::string represents a pseudo vector serialization representation
 399         notice_pkt << (u8) PLAYER_LIST_ADD << (u16) 1 << std::string(playersao->getPlayer()->getName());
 400         m_clients.sendToAll(&notice_pkt);
 401
 402         m_clients.event(peer_id, CSE_SetClientReady);
 403         m_script->on_joinplayer(playersao);
 404         // Send shutdown timer if shutdown has been scheduled
 405         if (m_shutdown_state.isTimerRunning()) {
 406                 SendChatMessage(pkt->getPeerId(), m_shutdown_state.getShutdownTimerMessage());
 407         }
 408 }
 409
 410 void Server::handleCommand_GotBlocks(NetworkPacket* pkt)
 411 {
 412         if (pkt->getSize() < 1)
 413                 return;
 414
 415         /*
 416                 [0] u16 command
 417                 [2] u8 count
 418                 [3] v3s16 pos_0
 419                 [3+6] v3s16 pos_1
 420                 ...
 421         */
 422
 423         u8 count;
 424         *pkt >> count;
 425
 426         RemoteClient *client = getClient(pkt->getPeerId());
 427
 428         if ((s16)pkt->getSize() < 1 + (int)count * 6) {
 429                 throw con::InvalidIncomingDataException
 430                                 ("GOTBLOCKS length is too short");
 431         }
 432
 433         for (u16 i = 0; i < count; i++) {
 434                 v3s16 p;
 435                 *pkt >> p;
 436                 client->GotBlock(p);
 437         }
 438 }
 439
 440 void Server::process_PlayerPos(RemotePlayer *player, PlayerSAO *playersao,
 441         NetworkPacket *pkt)
 442 {
 443         if (pkt->getRemainingBytes() < 12 + 12 + 4 + 4 + 4 + 1 + 1)
 444                 return;
 445
 446         v3s32 ps, ss;
 447         s32 f32pitch, f32yaw;
 448         u8 f32fov;
 449
 450         *pkt >> ps;
 451         *pkt >> ss;
 452         *pkt >> f32pitch;
 453         *pkt >> f32yaw;
 454
 455         f32 pitch = (f32)f32pitch / 100.0f;
 456         f32 yaw = (f32)f32yaw / 100.0f;
 457         u32 keyPressed = 0;
 458
 459         // default behavior (in case an old client doesn't send these)
 460         f32 fov = 0;
 461         u8 wanted_range = 0;
 462
 463         *pkt >> keyPressed;
 464         *pkt >> f32fov;
 465         fov = (f32)f32fov / 80.0f;
 466         *pkt >> wanted_range;
 467
 468         v3f position((f32)ps.X / 100.0f, (f32)ps.Y / 100.0f, (f32)ps.Z / 100.0f);
 469         v3f speed((f32)ss.X / 100.0f, (f32)ss.Y / 100.0f, (f32)ss.Z / 100.0f);
 470
 471         pitch = modulo360f(pitch);
 472         yaw = wrapDegrees_0_360(yaw);
 473
 474         playersao->setBasePosition(position);
 475         player->setSpeed(speed);
 476         playersao->setLookPitch(pitch);
 477         playersao->setPlayerYaw(yaw);
 478         playersao->setFov(fov);
 479         playersao->setWantedRange(wanted_range);
 480         player->keyPressed = keyPressed;
 481         player->control.up = (keyPressed & 1);
 482         player->control.down = (keyPressed & 2);
 483         player->control.left = (keyPressed & 4);
 484         player->control.right = (keyPressed & 8);
 485         player->control.jump = (keyPressed & 16);
 486         player->control.aux1 = (keyPressed & 32);
 487         player->control.sneak = (keyPressed & 64);
 488         player->control.LMB = (keyPressed & 128);
 489         player->control.RMB = (keyPressed & 256);
 490
 491         if (playersao->checkMovementCheat()) {
 492                 // Call callbacks
 493                 m_script->on_cheat(playersao, "moved_too_fast");
 494                 SendMovePlayer(pkt->getPeerId());
 495         }
 496 }
 497
 498 void Server::handleCommand_PlayerPos(NetworkPacket* pkt)
 499 {
 500         RemotePlayer *player = m_env->getPlayer(pkt->getPeerId());
 501         if (player == NULL) {
 502                 errorstream << "Server::ProcessData(): Canceling: "
 503                                 "No player for peer_id=" << pkt->getPeerId()
 504                                 << " disconnecting peer!" << std::endl;
 505                 DisconnectPeer(pkt->getPeerId());
 506                 return;
 507         }
 508
 509         PlayerSAO *playersao = player->getPlayerSAO();
 510         if (playersao == NULL) {
 511                 errorstream << "Server::ProcessData(): Canceling: "
 512                                 "No player object for peer_id=" << pkt->getPeerId()
 513                                 << " disconnecting peer!" << std::endl;
 514                 DisconnectPeer(pkt->getPeerId());
 515                 return;
 516         }
 517
 518         // If player is dead we don't care of this packet
 519         if (playersao->isDead()) {
 520                 verbosestream << "TOSERVER_PLAYERPOS: " << player->getName()
 521                                 << " is dead. Ignoring packet";
 522                 return;
 523         }
 524
 525         process_PlayerPos(player, playersao, pkt);
 526 }
 527
 528 void Server::handleCommand_DeletedBlocks(NetworkPacket* pkt)
 529 {
 530         if (pkt->getSize() < 1)
 531                 return;
 532
 533         /*
 534                 [0] u16 command
 535                 [2] u8 count
 536                 [3] v3s16 pos_0
 537                 [3+6] v3s16 pos_1
 538                 ...
 539         */
 540
 541         u8 count;
 542         *pkt >> count;
 543
 544         RemoteClient *client = getClient(pkt->getPeerId());
 545
 546         if ((s16)pkt->getSize() < 1 + (int)count * 6) {
 547                 throw con::InvalidIncomingDataException
 548                                 ("DELETEDBLOCKS length is too short");
 549         }
 550
 551         for (u16 i = 0; i < count; i++) {
 552                 v3s16 p;
 553                 *pkt >> p;
 554                 client->SetBlockNotSent(p);
 555         }
 556 }
 557
 558 void Server::handleCommand_InventoryAction(NetworkPacket* pkt)
 559 {
 560         RemotePlayer *player = m_env->getPlayer(pkt->getPeerId());
 561
 562         if (player == NULL) {
 563                 errorstream << "Server::ProcessData(): Canceling: "
 564                                 "No player for peer_id=" << pkt->getPeerId()
 565                                 << " disconnecting peer!" << std::endl;
 566                 DisconnectPeer(pkt->getPeerId());
 567                 return;
 568         }
 569
 570         PlayerSAO *playersao = player->getPlayerSAO();
 571         if (playersao == NULL) {
 572                 errorstream << "Server::ProcessData(): Canceling: "
 573                                 "No player object for peer_id=" << pkt->getPeerId()
 574                                 << " disconnecting peer!" << std::endl;
 575                 DisconnectPeer(pkt->getPeerId());
 576                 return;
 577         }
 578
 579         // Strip command and create a stream
 580         std::string datastring(pkt->getString(0), pkt->getSize());
 581         verbosestream << "TOSERVER_INVENTORY_ACTION: data=" << datastring
 582                 << std::endl;
 583         std::istringstream is(datastring, std::ios_base::binary);
 584         // Create an action
 585         InventoryAction *a = InventoryAction::deSerialize(is);
 586         if (!a) {
 587                 infostream << "TOSERVER_INVENTORY_ACTION: "
 588                                 << "InventoryAction::deSerialize() returned NULL"
 589                                 << std::endl;
 590                 return;
 591         }
 592
 593         // If something goes wrong, this player is to blame
 594         RollbackScopeActor rollback_scope(m_rollback,
 595                         std::string("player:")+player->getName());
 596
 597         /*
 598                 Note: Always set inventory not sent, to repair cases
 599                 where the client made a bad prediction.
 600         */
 601
 602         /*
 603                 Handle restrictions and special cases of the move action
 604         */
 605         if (a->getType() == IAction::Move) {
 606                 IMoveAction *ma = (IMoveAction*)a;
 607
 608                 ma->from_inv.applyCurrentPlayer(player->getName());
 609                 ma->to_inv.applyCurrentPlayer(player->getName());
 610
 611                 setInventoryModified(ma->from_inv, false);
 612                 if (ma->from_inv != ma->to_inv) {
 613                         setInventoryModified(ma->to_inv, false);
 614                 }
 615
 616                 bool from_inv_is_current_player =
 617                         (ma->from_inv.type == InventoryLocation::PLAYER) &&
 618                         (ma->from_inv.name == player->getName());
 619
 620                 bool to_inv_is_current_player =
 621                         (ma->to_inv.type == InventoryLocation::PLAYER) &&
 622                         (ma->to_inv.name == player->getName());
 623
 624                 InventoryLocation *remote = from_inv_is_current_player ?
 625                         &ma->to_inv : &ma->from_inv;
 626
 627                 // Check for out-of-range interaction
 628                 if (remote->type == InventoryLocation::NODEMETA) {
 629                         v3f node_pos   = intToFloat(remote->p, BS);
 630                         v3f player_pos = player->getPlayerSAO()->getEyePosition();
 631                         f32 d = player_pos.getDistanceFrom(node_pos);
 632                         if (!checkInteractDistance(player, d, "inventory"))
 633                                 return;
 634                 }
 635
 636                 /*
 637                         Disable moving items out of craftpreview
 638                 */
 639                 if (ma->from_list == "craftpreview") {
 640                         infostream << "Ignoring IMoveAction from "
 641                                         << (ma->from_inv.dump()) << ":" << ma->from_list
 642                                         << " to " << (ma->to_inv.dump()) << ":" << ma->to_list
 643                                         << " because src is " << ma->from_list << std::endl;
 644                         delete a;
 645                         return;
 646                 }
 647
 648                 /*
 649                         Disable moving items into craftresult and craftpreview
 650                 */
 651                 if (ma->to_list == "craftpreview" || ma->to_list == "craftresult") {
 652                         infostream << "Ignoring IMoveAction from "
 653                                         << (ma->from_inv.dump()) << ":" << ma->from_list
 654                                         << " to " << (ma->to_inv.dump()) << ":" << ma->to_list
 655                                         << " because dst is " << ma->to_list << std::endl;
 656                         delete a;
 657                         return;
 658                 }
 659
 660                 // Disallow moving items in elsewhere than player's inventory
 661                 // if not allowed to interact
 662                 if (!checkPriv(player->getName(), "interact") &&
 663                                 (!from_inv_is_current_player ||
 664                                 !to_inv_is_current_player)) {
 665                         infostream << "Cannot move outside of player's inventory: "
 666                                         << "No interact privilege" << std::endl;
 667                         delete a;
 668                         return;
 669                 }
 670         }
 671         /*
 672                 Handle restrictions and special cases of the drop action
 673         */
 674         else if (a->getType() == IAction::Drop) {
 675                 IDropAction *da = (IDropAction*)a;
 676
 677                 da->from_inv.applyCurrentPlayer(player->getName());
 678
 679                 setInventoryModified(da->from_inv, false);
 680
 681                 /*
 682                         Disable dropping items out of craftpreview
 683                 */
 684                 if (da->from_list == "craftpreview") {
 685                         infostream << "Ignoring IDropAction from "
 686                                         << (da->from_inv.dump()) << ":" << da->from_list
 687                                         << " because src is " << da->from_list << std::endl;
 688                         delete a;
 689                         return;
 690                 }
 691
 692                 // Disallow dropping items if not allowed to interact
 693                 if (!checkPriv(player->getName(), "interact")) {
 694                         delete a;
 695                         return;
 696                 }
 697
 698                 // Disallow dropping items if dead
 699                 if (playersao->isDead()) {
 700                         infostream << "Ignoring IDropAction from "
 701                                         << (da->from_inv.dump()) << ":" << da->from_list
 702                                         << " because player is dead." << std::endl;
 703                         delete a;
 704                         return;
 705                 }
 706         }
 707         /*
 708                 Handle restrictions and special cases of the craft action
 709         */
 710         else if (a->getType() == IAction::Craft) {
 711                 ICraftAction *ca = (ICraftAction*)a;
 712
 713                 ca->craft_inv.applyCurrentPlayer(player->getName());
 714
 715                 setInventoryModified(ca->craft_inv, false);
 716
 717                 //bool craft_inv_is_current_player =
 718                 //      (ca->craft_inv.type == InventoryLocation::PLAYER) &&
 719                 //      (ca->craft_inv.name == player->getName());
 720
 721                 // Disallow crafting if not allowed to interact
 722                 if (!checkPriv(player->getName(), "interact")) {
 723                         infostream << "Cannot craft: "
 724                                         << "No interact privilege" << std::endl;
 725                         delete a;
 726                         return;
 727                 }
 728         }
 729
 730         // Do the action
 731         a->apply(this, playersao, this);
 732         // Eat the action
 733         delete a;
 734
 735         SendInventory(playersao);
 736 }
 737
 738 void Server::handleCommand_ChatMessage(NetworkPacket* pkt)
 739 {
 740         /*
 741                 u16 command
 742                 u16 length
 743                 wstring message
 744         */
 745         u16 len;
 746         *pkt >> len;
 747
 748         std::wstring message;
 749         for (u16 i = 0; i < len; i++) {
 750                 u16 tmp_wchar;
 751                 *pkt >> tmp_wchar;
 752
 753                 message += (wchar_t)tmp_wchar;
 754         }
 755
 756         RemotePlayer *player = m_env->getPlayer(pkt->getPeerId());
 757         if (player == NULL) {
 758                 errorstream << "Server::ProcessData(): Canceling: "
 759                                 "No player for peer_id=" << pkt->getPeerId()
 760                                 << " disconnecting peer!" << std::endl;
 761                 DisconnectPeer(pkt->getPeerId());
 762                 return;
 763         }
 764
 765         // Get player name of this client
 766         std::string name = player->getName();
 767         std::wstring wname = narrow_to_wide(name);
 768
 769         std::wstring answer_to_sender = handleChat(name, wname, message, true, player);
 770         if (!answer_to_sender.empty()) {
 771                 // Send the answer to sender
 772                 SendChatMessage(pkt->getPeerId(), ChatMessage(CHATMESSAGE_TYPE_NORMAL,
 773                                 answer_to_sender, wname));
 774         }
 775 }
 776
 777 void Server::handleCommand_Damage(NetworkPacket* pkt)
 778 {
 779         u16 damage;
 780
 781         *pkt >> damage;
 782
 783         RemotePlayer *player = m_env->getPlayer(pkt->getPeerId());
 784
 785         if (player == NULL) {
 786                 errorstream << "Server::ProcessData(): Canceling: "
 787                                 "No player for peer_id=" << pkt->getPeerId()
 788                                 << " disconnecting peer!" << std::endl;
 789                 DisconnectPeer(pkt->getPeerId());
 790                 return;
 791         }
 792
 793         PlayerSAO *playersao = player->getPlayerSAO();
 794         if (playersao == NULL) {
 795                 errorstream << "Server::ProcessData(): Canceling: "
 796                                 "No player object for peer_id=" << pkt->getPeerId()
 797                                 << " disconnecting peer!" << std::endl;
 798                 DisconnectPeer(pkt->getPeerId());
 799                 return;
 800         }
 801
 802         if (!playersao->isImmortal()) {
 803                 if (playersao->isDead()) {
 804                         verbosestream << "Server::ProcessData(): Info: "
 805                                 "Ignoring damage as player " << player->getName()
 806                                 << " is already dead." << std::endl;
 807                         return;
 808                 }
 809
 810                 actionstream << player->getName() << " damaged by "
 811                                 << (int)damage << " hp at " << PP(playersao->getBasePosition() / BS)
 812                                 << std::endl;
 813
 814                 PlayerHPChangeReason reason(PlayerHPChangeReason::FALL);
 815                 playersao->setHP((s32)playersao->getHP() - (s32)damage, reason);
 816                 SendPlayerHPOrDie(playersao, reason);
 817         }
 818 }
 819
 820 void Server::handleCommand_Password(NetworkPacket* pkt)
 821 {
 822         if (pkt->getSize() != PASSWORD_SIZE * 2)
 823                 return;
 824
 825         std::string oldpwd;
 826         std::string newpwd;
 827
 828         // Deny for clients using the new protocol
 829         RemoteClient* client = getClient(pkt->getPeerId(), CS_Created);
 830         if (client->net_proto_version >= 25) {
 831                 infostream << "Server::handleCommand_Password(): Denying change: "
 832                         << " Client protocol version for peer_id=" << pkt->getPeerId()
 833                         << " too new!" << std::endl;
 834                 return;
 835         }
 836
 837         for (u16 i = 0; i < PASSWORD_SIZE - 1; i++) {
 838                 char c = pkt->getChar(i);
 839                 if (c == 0)
 840                         break;
 841                 oldpwd += c;
 842         }
 843
 844         for (u16 i = 0; i < PASSWORD_SIZE - 1; i++) {
 845                 char c = pkt->getChar(PASSWORD_SIZE + i);
 846                 if (c == 0)
 847                         break;
 848                 newpwd += c;
 849         }
 850
 851         RemotePlayer *player = m_env->getPlayer(pkt->getPeerId());
 852         if (player == NULL) {
 853                 errorstream << "Server::ProcessData(): Canceling: "
 854                                 "No player for peer_id=" << pkt->getPeerId()
 855                                 << " disconnecting peer!" << std::endl;
 856                 DisconnectPeer(pkt->getPeerId());
 857                 return;
 858         }
 859
 860         if (!base64_is_valid(newpwd)) {
 861                 infostream<<"Server: " << player->getName() <<
 862                                 " supplied invalid password hash" << std::endl;
 863                 // Wrong old password supplied!!
 864                 SendChatMessage(pkt->getPeerId(), ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
 865                                 L"Invalid new password hash supplied. Password NOT changed."));
 866                 return;
 867         }
 868
 869         infostream << "Server: Client requests a password change from "
 870                         << "'" << oldpwd << "' to '" << newpwd << "'" << std::endl;
 871
 872         std::string playername = player->getName();
 873
 874         std::string checkpwd;
 875         m_script->getAuth(playername, &checkpwd, NULL);
 876
 877         if (oldpwd != checkpwd) {
 878                 infostream << "Server: invalid old password" << std::endl;
 879                 // Wrong old password supplied!!
 880                 SendChatMessage(pkt->getPeerId(), ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
 881                                 L"Invalid old password supplied. Password NOT changed."));
 882                 return;
 883         }
 884
 885         bool success = m_script->setPassword(playername, newpwd);
 886         if (success) {
 887                 actionstream << player->getName() << " changes password" << std::endl;
 888                 SendChatMessage(pkt->getPeerId(), ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
 889                                 L"Password change successful."));
 890         } else {
 891                 actionstream << player->getName() << " tries to change password but "
 892                                 << "it fails" << std::endl;
 893                 SendChatMessage(pkt->getPeerId(), ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
 894                                 L"Password change failed or unavailable."));
 895         }
 896 }
 897
 898 void Server::handleCommand_PlayerItem(NetworkPacket* pkt)
 899 {
 900         if (pkt->getSize() < 2)
 901                 return;
 902
 903         RemotePlayer *player = m_env->getPlayer(pkt->getPeerId());
 904
 905         if (player == NULL) {
 906                 errorstream << "Server::ProcessData(): Canceling: "
 907                                 "No player for peer_id=" << pkt->getPeerId()
 908                                 << " disconnecting peer!" << std::endl;
 909                 DisconnectPeer(pkt->getPeerId());
 910                 return;
 911         }
 912
 913         PlayerSAO *playersao = player->getPlayerSAO();
 914         if (playersao == NULL) {
 915                 errorstream << "Server::ProcessData(): Canceling: "
 916                                 "No player object for peer_id=" << pkt->getPeerId()
 917                                 << " disconnecting peer!" << std::endl;
 918                 DisconnectPeer(pkt->getPeerId());
 919                 return;
 920         }
 921
 922         u16 item;
 923
 924         *pkt >> item;
 925
 926         playersao->setWieldIndex(item);
 927 }
 928
 929 void Server::handleCommand_Respawn(NetworkPacket* pkt)
 930 {
 931         RemotePlayer *player = m_env->getPlayer(pkt->getPeerId());
 932         if (player == NULL) {
 933                 errorstream << "Server::ProcessData(): Canceling: "
 934                                 "No player for peer_id=" << pkt->getPeerId()
 935                                 << " disconnecting peer!" << std::endl;
 936                 DisconnectPeer(pkt->getPeerId());
 937                 return;
 938         }
 939
 940         PlayerSAO *playersao = player->getPlayerSAO();
 941         assert(playersao);
 942
 943         if (!playersao->isDead())
 944                 return;
 945
 946         RespawnPlayer(pkt->getPeerId());
 947
 948         actionstream << player->getName() << " respawns at "
 949                         << PP(playersao->getBasePosition() / BS) << std::endl;
 950
 951         // ActiveObject is added to environment in AsyncRunStep after
 952         // the previous addition has been successfully removed
 953 }
 954
 955 bool Server::checkInteractDistance(RemotePlayer *player, const f32 d, const std::string &what)
 956 {
 957         PlayerSAO *playersao = player->getPlayerSAO();
 958         const InventoryList *hlist = playersao->getInventory()->getList("hand");
 959         const ItemDefinition &playeritem_def =
 960                 playersao->getWieldedItem().getDefinition(m_itemdef);
 961         const ItemDefinition &hand_def =
 962                 hlist ? hlist->getItem(0).getDefinition(m_itemdef) : m_itemdef->get("");
 963
 964         float max_d = BS * playeritem_def.range;
 965         float max_d_hand = BS * hand_def.range;
 966
 967         if (max_d < 0 && max_d_hand >= 0)
 968                 max_d = max_d_hand;
 969         else if (max_d < 0)
 970                 max_d = BS * 4.0f;
 971
 972         // Cube diagonal * 1.5 for maximal supported node extents:
 973         // sqrt(3) * 1.5 ≅ 2.6
 974         if (d > max_d + 2.6f * BS) {
 975                 actionstream << "Player " << player->getName()
 976                                 << " tried to access " << what
 977                                 << " from too far: "
 978                                 << "d=" << d <<", max_d=" << max_d
 979                                 << ". ignoring." << std::endl;
 980                 // Call callbacks
 981                 m_script->on_cheat(playersao, "interacted_too_far");
 982                 return false;
 983         }
 984         return true;
 985 }
 986
 987 void Server::handleCommand_Interact(NetworkPacket* pkt)
 988 {
 989         /*
 990                 [0] u16 command
 991                 [2] u8 action
 992                 [3] u16 item
 993                 [5] u32 length of the next item (plen)
 994                 [9] serialized PointedThing
 995                 [9 + plen] player position information
 996                 actions:
 997                 0: start digging (from undersurface) or use
 998                 1: stop digging (all parameters ignored)
 999                 2: digging completed
1000                 3: place block or item (to abovesurface)
1001                 4: use item
1002                 5: rightclick air ("activate")
1003         */
1004         u8 action;
1005         u16 item_i;
1006         *pkt >> action;
1007         *pkt >> item_i;
1008         std::istringstream tmp_is(pkt->readLongString(), std::ios::binary);
1009         PointedThing pointed;
1010         pointed.deSerialize(tmp_is);
1011
1012         verbosestream << "TOSERVER_INTERACT: action=" << (int)action << ", item="
1013                         << item_i << ", pointed=" << pointed.dump() << std::endl;
1014
1015         RemotePlayer *player = m_env->getPlayer(pkt->getPeerId());
1016
1017         if (player == NULL) {
1018                 errorstream << "Server::ProcessData(): Canceling: "
1019                                 "No player for peer_id=" << pkt->getPeerId()
1020                                 << " disconnecting peer!" << std::endl;
1021                 DisconnectPeer(pkt->getPeerId());
1022                 return;
1023         }
1024
1025         PlayerSAO *playersao = player->getPlayerSAO();
1026         if (playersao == NULL) {
1027                 errorstream << "Server::ProcessData(): Canceling: "
1028                                 "No player object for peer_id=" << pkt->getPeerId()
1029                                 << " disconnecting peer!" << std::endl;
1030                 DisconnectPeer(pkt->getPeerId());
1031                 return;
1032         }
1033
1034         if (playersao->isDead()) {
1035                 actionstream << "Server: NoCheat: " << player->getName()
1036                                 << " tried to interact while dead; ignoring." << std::endl;
1037                 if (pointed.type == POINTEDTHING_NODE) {
1038                         // Re-send block to revert change on client-side
1039                         RemoteClient *client = getClient(pkt->getPeerId());
1040                         v3s16 blockpos = getNodeBlockPos(pointed.node_undersurface);
1041                         client->SetBlockNotSent(blockpos);
1042                 }
1043                 // Call callbacks
1044                 m_script->on_cheat(playersao, "interacted_while_dead");
1045                 return;
1046         }
1047
1048         process_PlayerPos(player, playersao, pkt);
1049
1050         v3f player_pos = playersao->getLastGoodPosition();
1051
1052         // Update wielded item
1053         playersao->setWieldIndex(item_i);
1054
1055         // Get pointed to node (undefined if not POINTEDTYPE_NODE)
1056         v3s16 p_under = pointed.node_undersurface;
1057         v3s16 p_above = pointed.node_abovesurface;
1058
1059         // Get pointed to object (NULL if not POINTEDTYPE_OBJECT)
1060         ServerActiveObject *pointed_object = NULL;
1061         if (pointed.type == POINTEDTHING_OBJECT) {
1062                 pointed_object = m_env->getActiveObject(pointed.object_id);
1063                 if (pointed_object == NULL) {
1064                         verbosestream << "TOSERVER_INTERACT: "
1065                                 "pointed object is NULL" << std::endl;
1066                         return;
1067                 }
1068
1069         }
1070
1071         v3f pointed_pos_under = player_pos;
1072         v3f pointed_pos_above = player_pos;
1073         if (pointed.type == POINTEDTHING_NODE) {
1074                 pointed_pos_under = intToFloat(p_under, BS);
1075                 pointed_pos_above = intToFloat(p_above, BS);
1076         }
1077         else if (pointed.type == POINTEDTHING_OBJECT) {
1078                 pointed_pos_under = pointed_object->getBasePosition();
1079                 pointed_pos_above = pointed_pos_under;
1080         }
1081
1082         /*
1083                 Make sure the player is allowed to do it
1084         */
1085         if (!checkPriv(player->getName(), "interact")) {
1086                 actionstream<<player->getName()<<" attempted to interact with "
1087                                 <<pointed.dump()<<" without 'interact' privilege"
1088                                 <<std::endl;
1089                 // Re-send block to revert change on client-side
1090                 RemoteClient *client = getClient(pkt->getPeerId());
1091                 // Digging completed -> under
1092                 if (action == 2) {
1093                         v3s16 blockpos = getNodeBlockPos(floatToInt(pointed_pos_under, BS));
1094                         client->SetBlockNotSent(blockpos);
1095                 }
1096                 // Placement -> above
1097                 else if (action == 3) {
1098                         v3s16 blockpos = getNodeBlockPos(floatToInt(pointed_pos_above, BS));
1099                         client->SetBlockNotSent(blockpos);
1100                 }
1101                 return;
1102         }
1103
1104         /*
1105                 Check that target is reasonably close
1106                 (only when digging or placing things)
1107         */
1108         static thread_local const bool enable_anticheat =
1109                         !g_settings->getBool("disable_anticheat");
1110
1111         if ((action == 0 || action == 2 || action == 3 || action == 4) &&
1112                         enable_anticheat && !isSingleplayer()) {
1113                 float d = playersao->getEyePosition()
1114                         .getDistanceFrom(pointed_pos_under);
1115
1116                 if (!checkInteractDistance(player, d, pointed.dump())) {
1117                         // Re-send block to revert change on client-side
1118                         RemoteClient *client = getClient(pkt->getPeerId());
1119                         v3s16 blockpos = getNodeBlockPos(floatToInt(pointed_pos_under, BS));
1120                         client->SetBlockNotSent(blockpos);
1121                         return;
1122                 }
1123         }
1124
1125         /*
1126                 If something goes wrong, this player is to blame
1127         */
1128         RollbackScopeActor rollback_scope(m_rollback,
1129                         std::string("player:")+player->getName());
1130
1131         /*
1132                 0: start digging or punch object
1133         */
1134         if (action == 0) {
1135                 if (pointed.type == POINTEDTHING_NODE) {
1136                         MapNode n(CONTENT_IGNORE);
1137                         bool pos_ok;
1138
1139                         n = m_env->getMap().getNodeNoEx(p_under, &pos_ok);
1140                         if (!pos_ok) {
1141                                 infostream << "Server: Not punching: Node not found."
1142                                                 << " Adding block to emerge queue."
1143                                                 << std::endl;
1144                                 m_emerge->enqueueBlockEmerge(pkt->getPeerId(),
1145                                         getNodeBlockPos(p_above), false);
1146                         }
1147
1148                         if (n.getContent() != CONTENT_IGNORE)
1149                                 m_script->node_on_punch(p_under, n, playersao, pointed);
1150
1151                         // Cheat prevention
1152                         playersao->noCheatDigStart(p_under);
1153                 }
1154                 else if (pointed.type == POINTEDTHING_OBJECT) {
1155                         // Skip if object can't be interacted with anymore
1156                         if (pointed_object->isGone())
1157                                 return;
1158
1159                         ItemStack punchitem = playersao->getWieldedItemOrHand();
1160                         ToolCapabilities toolcap =
1161                                         punchitem.getToolCapabilities(m_itemdef);
1162                         v3f dir = (pointed_object->getBasePosition() -
1163                                         (playersao->getBasePosition() + playersao->getEyeOffset())
1164                                                 ).normalize();
1165                         float time_from_last_punch =
1166                                 playersao->resetTimeFromLastPunch();
1167
1168                         u16 src_original_hp = pointed_object->getHP();
1169                         u16 dst_origin_hp = playersao->getHP();
1170
1171                         pointed_object->punch(dir, &toolcap, playersao,
1172                                         time_from_last_punch);
1173
1174                         // If the object is a player and its HP changed
1175                         if (src_original_hp != pointed_object->getHP() &&
1176                                         pointed_object->getType() == ACTIVEOBJECT_TYPE_PLAYER) {
1177                                 SendPlayerHPOrDie((PlayerSAO *)pointed_object,
1178                                                 PlayerHPChangeReason(PlayerHPChangeReason::PLAYER_PUNCH, playersao));
1179                         }
1180
1181                         // If the puncher is a player and its HP changed
1182                         if (dst_origin_hp != playersao->getHP())
1183                                 SendPlayerHPOrDie(playersao,
1184                                                 PlayerHPChangeReason(PlayerHPChangeReason::PLAYER_PUNCH, pointed_object));
1185                 }
1186
1187         } // action == 0
1188
1189         /*
1190                 1: stop digging
1191         */
1192         else if (action == 1) {
1193         } // action == 1
1194
1195         /*
1196                 2: Digging completed
1197         */
1198         else if (action == 2) {
1199                 // Only digging of nodes
1200                 if (pointed.type == POINTEDTHING_NODE) {
1201                         bool pos_ok;
1202                         MapNode n = m_env->getMap().getNodeNoEx(p_under, &pos_ok);
1203                         if (!pos_ok) {
1204                                 infostream << "Server: Not finishing digging: Node not found."
1205                                                 << " Adding block to emerge queue."
1206                                                 << std::endl;
1207                                 m_emerge->enqueueBlockEmerge(pkt->getPeerId(),
1208                                         getNodeBlockPos(p_above), false);
1209                         }
1210
1211                         /* Cheat prevention */
1212                         bool is_valid_dig = true;
1213                         if (enable_anticheat && !isSingleplayer()) {
1214                                 v3s16 nocheat_p = playersao->getNoCheatDigPos();
1215                                 float nocheat_t = playersao->getNoCheatDigTime();
1216                                 playersao->noCheatDigEnd();
1217                                 // If player didn't start digging this, ignore dig
1218                                 if (nocheat_p != p_under) {
1219                                         infostream << "Server: NoCheat: " << player->getName()
1220                                                         << " started digging "
1221                                                         << PP(nocheat_p) << " and completed digging "
1222                                                         << PP(p_under) << "; not digging." << std::endl;
1223                                         is_valid_dig = false;
1224                                         // Call callbacks
1225                                         m_script->on_cheat(playersao, "finished_unknown_dig");
1226                                 }
1227                                 // Get player's wielded item
1228                                 ItemStack playeritem = playersao->getWieldedItemOrHand();
1229                                 ToolCapabilities playeritem_toolcap =
1230                                                 playeritem.getToolCapabilities(m_itemdef);
1231                                 // Get diggability and expected digging time
1232                                 DigParams params = getDigParams(m_nodedef->get(n).groups,
1233                                                 &playeritem_toolcap);
1234                                 // If can't dig, try hand
1235                                 if (!params.diggable) {
1236                                         InventoryList *hlist = playersao->getInventory()->getList("hand");
1237                                         const ToolCapabilities *tp = hlist
1238                                                 ? &hlist->getItem(0).getToolCapabilities(m_itemdef)
1239                                                 : m_itemdef->get("").tool_capabilities;
1240
1241                                         if (tp)
1242                                                 params = getDigParams(m_nodedef->get(n).groups, tp);
1243                                 }
1244                                 // If can't dig, ignore dig
1245                                 if (!params.diggable) {
1246                                         infostream << "Server: NoCheat: " << player->getName()
1247                                                         << " completed digging " << PP(p_under)
1248                                                         << ", which is not diggable with tool. not digging."
1249                                                         << std::endl;
1250                                         is_valid_dig = false;
1251                                         // Call callbacks
1252                                         m_script->on_cheat(playersao, "dug_unbreakable");
1253                                 }
1254                                 // Check digging time
1255                                 // If already invalidated, we don't have to
1256                                 if (!is_valid_dig) {
1257                                         // Well not our problem then
1258                                 }
1259                                 // Clean and long dig
1260                                 else if (params.time > 2.0 && nocheat_t * 1.2 > params.time) {
1261                                         // All is good, but grab time from pool; don't care if
1262                                         // it's actually available
1263                                         playersao->getDigPool().grab(params.time);
1264                                 }
1265                                 // Short or laggy dig
1266                                 // Try getting the time from pool
1267                                 else if (playersao->getDigPool().grab(params.time)) {
1268                                         // All is good
1269                                 }
1270                                 // Dig not possible
1271                                 else {
1272                                         infostream << "Server: NoCheat: " << player->getName()
1273                                                         << " completed digging " << PP(p_under)
1274                                                         << "too fast; not digging." << std::endl;
1275                                         is_valid_dig = false;
1276                                         // Call callbacks
1277                                         m_script->on_cheat(playersao, "dug_too_fast");
1278                                 }
1279                         }
1280
1281                         /* Actually dig node */
1282
1283                         if (is_valid_dig && n.getContent() != CONTENT_IGNORE)
1284                                 m_script->node_on_dig(p_under, n, playersao);
1285
1286                         v3s16 blockpos = getNodeBlockPos(floatToInt(pointed_pos_under, BS));
1287                         RemoteClient *client = getClient(pkt->getPeerId());
1288                         // Send unusual result (that is, node not being removed)
1289                         if (m_env->getMap().getNodeNoEx(p_under).getContent() != CONTENT_AIR) {
1290                                 // Re-send block to revert change on client-side
1291                                 client->SetBlockNotSent(blockpos);
1292                         }
1293                         else {
1294                                 client->ResendBlockIfOnWire(blockpos);
1295                         }
1296                 }
1297         } // action == 2
1298
1299         /*
1300                 3: place block or right-click object
1301         */
1302         else if (action == 3) {
1303                 ItemStack item = playersao->getWieldedItem();
1304
1305                 // Reset build time counter
1306                 if (pointed.type == POINTEDTHING_NODE &&
1307                                 item.getDefinition(m_itemdef).type == ITEM_NODE)
1308                         getClient(pkt->getPeerId())->m_time_from_building = 0.0;
1309
1310                 if (pointed.type == POINTEDTHING_OBJECT) {
1311                         // Right click object
1312
1313                         // Skip if object can't be interacted with anymore
1314                         if (pointed_object->isGone())
1315                                 return;
1316
1317                         actionstream << player->getName() << " right-clicks object "
1318                                         << pointed.object_id << ": "
1319                                         << pointed_object->getDescription() << std::endl;
1320
1321                         // Do stuff
1322                         pointed_object->rightClick(playersao);
1323                 }
1324                 else if (m_script->item_OnPlace(
1325                                 item, playersao, pointed)) {
1326                         // Placement was handled in lua
1327
1328                         // Apply returned ItemStack
1329                         if (playersao->setWieldedItem(item)) {
1330                                 SendInventory(playersao);
1331                         }
1332                 }
1333
1334                 // If item has node placement prediction, always send the
1335                 // blocks to make sure the client knows what exactly happened
1336                 RemoteClient *client = getClient(pkt->getPeerId());
1337                 v3s16 blockpos = getNodeBlockPos(floatToInt(pointed_pos_above, BS));
1338                 v3s16 blockpos2 = getNodeBlockPos(floatToInt(pointed_pos_under, BS));
1339                 if (!item.getDefinition(m_itemdef).node_placement_prediction.empty()) {
1340                         client->SetBlockNotSent(blockpos);
1341                         if (blockpos2 != blockpos) {
1342                                 client->SetBlockNotSent(blockpos2);
1343                         }
1344                 }
1345                 else {
1346                         client->ResendBlockIfOnWire(blockpos);
1347                         if (blockpos2 != blockpos) {
1348                                 client->ResendBlockIfOnWire(blockpos2);
1349                         }
1350                 }
1351         } // action == 3
1352
1353         /*
1354                 4: use
1355         */
1356         else if (action == 4) {
1357                 ItemStack item = playersao->getWieldedItem();
1358
1359                 actionstream << player->getName() << " uses " << item.name
1360                                 << ", pointing at " << pointed.dump() << std::endl;
1361
1362                 if (m_script->item_OnUse(
1363                                 item, playersao, pointed)) {
1364                         // Apply returned ItemStack
1365                         if (playersao->setWieldedItem(item)) {
1366                                 SendInventory(playersao);
1367                         }
1368                 }
1369
1370         } // action == 4
1371
1372         /*
1373                 5: rightclick air
1374         */
1375         else if (action == 5) {
1376                 ItemStack item = playersao->getWieldedItem();
1377
1378                 actionstream << player->getName() << " activates "
1379                                 << item.name << std::endl;
1380
1381                 if (m_script->item_OnSecondaryUse(
1382                                 item, playersao)) {
1383                         if( playersao->setWieldedItem(item)) {
1384                                 SendInventory(playersao);
1385                         }
1386                 }
1387         }
1388
1389
1390         /*
1391                 Catch invalid actions
1392         */
1393         else {
1394                 warningstream << "Server: Invalid action "
1395                                 << action << std::endl;
1396         }
1397 }
1398
1399 void Server::handleCommand_RemovedSounds(NetworkPacket* pkt)
1400 {
1401         u16 num;
1402         *pkt >> num;
1403         for (u16 k = 0; k < num; k++) {
1404                 s32 id;
1405
1406                 *pkt >> id;
1407
1408                 std::unordered_map<s32, ServerPlayingSound>::iterator i =
1409                         m_playing_sounds.find(id);
1410                 if (i == m_playing_sounds.end())
1411                         continue;
1412
1413                 ServerPlayingSound &psound = i->second;
1414                 psound.clients.erase(pkt->getPeerId());
1415                 if (psound.clients.empty())
1416                         m_playing_sounds.erase(i++);
1417         }
1418 }
1419
1420 void Server::handleCommand_NodeMetaFields(NetworkPacket* pkt)
1421 {
1422         v3s16 p;
1423         std::string formname;
1424         u16 num;
1425
1426         *pkt >> p >> formname >> num;
1427
1428         StringMap fields;
1429         for (u16 k = 0; k < num; k++) {
1430                 std::string fieldname;
1431                 *pkt >> fieldname;
1432                 fields[fieldname] = pkt->readLongString();
1433         }
1434
1435         RemotePlayer *player = m_env->getPlayer(pkt->getPeerId());
1436
1437         if (player == NULL) {
1438                 errorstream << "Server::ProcessData(): Canceling: "
1439                                 "No player for peer_id=" << pkt->getPeerId()
1440                                 << " disconnecting peer!" << std::endl;
1441                 DisconnectPeer(pkt->getPeerId());
1442                 return;
1443         }
1444
1445         PlayerSAO *playersao = player->getPlayerSAO();
1446         if (playersao == NULL) {
1447                 errorstream << "Server::ProcessData(): Canceling: "
1448                                 "No player object for peer_id=" << pkt->getPeerId()
1449                                 << " disconnecting peer!"  << std::endl;
1450                 DisconnectPeer(pkt->getPeerId());
1451                 return;
1452         }
1453
1454         // If something goes wrong, this player is to blame
1455         RollbackScopeActor rollback_scope(m_rollback,
1456                         std::string("player:")+player->getName());
1457
1458         // Check the target node for rollback data; leave others unnoticed
1459         RollbackNode rn_old(&m_env->getMap(), p, this);
1460
1461         m_script->node_on_receive_fields(p, formname, fields, playersao);
1462
1463         // Report rollback data
1464         RollbackNode rn_new(&m_env->getMap(), p, this);
1465         if (rollback() && rn_new != rn_old) {
1466                 RollbackAction action;
1467                 action.setSetNode(p, rn_old, rn_new);
1468                 rollback()->reportAction(action);
1469         }
1470 }
1471
1472 void Server::handleCommand_InventoryFields(NetworkPacket* pkt)
1473 {
1474         std::string client_formspec_name;
1475         u16 num;
1476
1477         *pkt >> client_formspec_name >> num;
1478
1479         StringMap fields;
1480         for (u16 k = 0; k < num; k++) {
1481                 std::string fieldname;
1482                 *pkt >> fieldname;
1483                 fields[fieldname] = pkt->readLongString();
1484         }
1485
1486         RemotePlayer *player = m_env->getPlayer(pkt->getPeerId());
1487
1488         if (player == NULL) {
1489                 errorstream << "Server::ProcessData(): Canceling: "
1490                                 "No player for peer_id=" << pkt->getPeerId()
1491                                 << " disconnecting peer!" << std::endl;
1492                 DisconnectPeer(pkt->getPeerId());
1493                 return;
1494         }
1495
1496         PlayerSAO *playersao = player->getPlayerSAO();
1497         if (playersao == NULL) {
1498                 errorstream << "Server::ProcessData(): Canceling: "
1499                                 "No player object for peer_id=" << pkt->getPeerId()
1500                                 << " disconnecting peer!" << std::endl;
1501                 DisconnectPeer(pkt->getPeerId());
1502                 return;
1503         }
1504
1505         if (client_formspec_name.empty()) { // pass through inventory submits
1506                 m_script->on_playerReceiveFields(playersao, client_formspec_name, fields);
1507                 return;
1508         }
1509
1510         // verify that we displayed the formspec to the user
1511         const auto peer_state_iterator = m_formspec_state_data.find(pkt->getPeerId());
1512         if (peer_state_iterator != m_formspec_state_data.end()) {
1513                 const std::string &server_formspec_name = peer_state_iterator->second;
1514                 if (client_formspec_name == server_formspec_name) {
1515                         auto it = fields.find("quit");
1516                         if (it != fields.end() && it->second == "true")
1517                                 m_formspec_state_data.erase(peer_state_iterator);
1518
1519                         m_script->on_playerReceiveFields(playersao, client_formspec_name, fields);
1520                         return;
1521                 }
1522                 actionstream << "'" << player->getName()
1523                         << "' submitted formspec ('" << client_formspec_name
1524                         << "') but the name of the formspec doesn't match the"
1525                         " expected name ('" << server_formspec_name << "')";
1526
1527         } else {
1528                 actionstream << "'" << player->getName()
1529                         << "' submitted formspec ('" << client_formspec_name
1530                         << "') but server hasn't sent formspec to client";
1531         }
1532         actionstream << ", possible exploitation attempt" << std::endl;
1533 }
1534
1535 void Server::handleCommand_FirstSrp(NetworkPacket* pkt)
1536 {
1537         RemoteClient* client = getClient(pkt->getPeerId(), CS_Invalid);
1538         ClientState cstate = client->getState();
1539
1540         std::string playername = client->getName();
1541
1542         std::string salt;
1543         std::string verification_key;
1544
1545         std::string addr_s = getPeerAddress(pkt->getPeerId()).serializeString();
1546         u8 is_empty;
1547
1548         *pkt >> salt >> verification_key >> is_empty;
1549
1550         verbosestream << "Server: Got TOSERVER_FIRST_SRP from " << addr_s
1551                 << ", with is_empty=" << (is_empty == 1) << std::endl;
1552
1553         // Either this packet is sent because the user is new or to change the password
1554         if (cstate == CS_HelloSent) {
1555                 if (!client->isMechAllowed(AUTH_MECHANISM_FIRST_SRP)) {
1556                         actionstream << "Server: Client from " << addr_s
1557                                         << " tried to set password without being "
1558                                         << "authenticated, or the username being new." << std::endl;
1559                         DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1560                         return;
1561                 }
1562
1563                 if (!isSingleplayer() &&
1564                                 g_settings->getBool("disallow_empty_password") &&
1565                                 is_empty == 1) {
1566                         actionstream << "Server: " << playername
1567                                         << " supplied empty password from " << addr_s << std::endl;
1568                         DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_EMPTY_PASSWORD);
1569                         return;
1570                 }
1571
1572                 std::string initial_ver_key;
1573
1574                 initial_ver_key = encode_srp_verifier(verification_key, salt);
1575                 m_script->createAuth(playername, initial_ver_key);
1576
1577                 acceptAuth(pkt->getPeerId(), false);
1578         } else {
1579                 if (cstate < CS_SudoMode) {
1580                         infostream << "Server::ProcessData(): Ignoring TOSERVER_FIRST_SRP from "
1581                                         << addr_s << ": " << "Client has wrong state " << cstate << "."
1582                                         << std::endl;
1583                         return;
1584                 }
1585                 m_clients.event(pkt->getPeerId(), CSE_SudoLeave);
1586                 std::string pw_db_field = encode_srp_verifier(verification_key, salt);
1587                 bool success = m_script->setPassword(playername, pw_db_field);
1588                 if (success) {
1589                         actionstream << playername << " changes password" << std::endl;
1590                         SendChatMessage(pkt->getPeerId(), ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
1591                                         L"Password change successful."));
1592                 } else {
1593                         actionstream << playername << " tries to change password but "
1594                                 << "it fails" << std::endl;
1595                         SendChatMessage(pkt->getPeerId(), ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
1596                                         L"Password change failed or unavailable."));
1597                 }
1598         }
1599 }
1600
1601 void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
1602 {
1603         RemoteClient* client = getClient(pkt->getPeerId(), CS_Invalid);
1604         ClientState cstate = client->getState();
1605
1606         bool wantSudo = (cstate == CS_Active);
1607
1608         if (!((cstate == CS_HelloSent) || (cstate == CS_Active))) {
1609                 actionstream << "Server: got SRP _A packet in wrong state "
1610                         << cstate << " from "
1611                         << getPeerAddress(pkt->getPeerId()).serializeString()
1612                         << ". Ignoring." << std::endl;
1613                 return;
1614         }
1615
1616         if (client->chosen_mech != AUTH_MECHANISM_NONE) {
1617                 actionstream << "Server: got SRP _A packet, while auth"
1618                         << "is already going on with mech " << client->chosen_mech
1619                         << " from " << getPeerAddress(pkt->getPeerId()).serializeString()
1620                         << " (wantSudo=" << wantSudo << "). Ignoring." << std::endl;
1621                 if (wantSudo) {
1622                         DenySudoAccess(pkt->getPeerId());
1623                         return;
1624                 }
1625
1626                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1627                 return;
1628         }
1629
1630         std::string bytes_A;
1631         u8 based_on;
1632         *pkt >> bytes_A >> based_on;
1633
1634         infostream << "Server: TOSERVER_SRP_BYTES_A received with "
1635                 << "based_on=" << int(based_on) << " and len_A="
1636                 << bytes_A.length() << "." << std::endl;
1637
1638         AuthMechanism chosen = (based_on == 0) ?
1639                 AUTH_MECHANISM_LEGACY_PASSWORD : AUTH_MECHANISM_SRP;
1640
1641         if (wantSudo) {
1642                 if (!client->isSudoMechAllowed(chosen)) {
1643                         actionstream << "Server: Player \"" << client->getName()
1644                                 << "\" at " << getPeerAddress(pkt->getPeerId()).serializeString()
1645                                 << " tried to change password using unallowed mech "
1646                                 << chosen << "." << std::endl;
1647                         DenySudoAccess(pkt->getPeerId());
1648                         return;
1649                 }
1650         } else {
1651                 if (!client->isMechAllowed(chosen)) {
1652                         actionstream << "Server: Client tried to authenticate from "
1653                                 << getPeerAddress(pkt->getPeerId()).serializeString()
1654                                 << " using unallowed mech " << chosen << "." << std::endl;
1655                         DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1656                         return;
1657                 }
1658         }
1659
1660         client->chosen_mech = chosen;
1661
1662         std::string salt;
1663         std::string verifier;
1664
1665         if (based_on == 0) {
1666
1667                 generate_srp_verifier_and_salt(client->getName(), client->enc_pwd,
1668                         &verifier, &salt);
1669         } else if (!decode_srp_verifier_and_salt(client->enc_pwd, &verifier, &salt)) {
1670                 // Non-base64 errors should have been catched in the init handler
1671                 actionstream << "Server: User " << client->getName()
1672                         << " tried to log in, but srp verifier field"
1673                         << " was invalid (most likely invalid base64)." << std::endl;
1674                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_SERVER_FAIL);
1675                 return;
1676         }
1677
1678         char *bytes_B = 0;
1679         size_t len_B = 0;
1680
1681         client->auth_data = srp_verifier_new(SRP_SHA256, SRP_NG_2048,
1682                 client->getName().c_str(),
1683                 (const unsigned char *) salt.c_str(), salt.size(),
1684                 (const unsigned char *) verifier.c_str(), verifier.size(),
1685                 (const unsigned char *) bytes_A.c_str(), bytes_A.size(),
1686                 NULL, 0,
1687                 (unsigned char **) &bytes_B, &len_B, NULL, NULL);
1688
1689         if (!bytes_B) {
1690                 actionstream << "Server: User " << client->getName()
1691                         << " tried to log in, SRP-6a safety check violated in _A handler."
1692                         << std::endl;
1693                 if (wantSudo) {
1694                         DenySudoAccess(pkt->getPeerId());
1695                         return;
1696                 }
1697
1698                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1699                 return;
1700         }
1701
1702         NetworkPacket resp_pkt(TOCLIENT_SRP_BYTES_S_B, 0, pkt->getPeerId());
1703         resp_pkt << salt << std::string(bytes_B, len_B);
1704         Send(&resp_pkt);
1705 }
1706
1707 void Server::handleCommand_SrpBytesM(NetworkPacket* pkt)
1708 {
1709         RemoteClient* client = getClient(pkt->getPeerId(), CS_Invalid);
1710         ClientState cstate = client->getState();
1711
1712         bool wantSudo = (cstate == CS_Active);
1713
1714         verbosestream << "Server: Received TOCLIENT_SRP_BYTES_M." << std::endl;
1715
1716         if (!((cstate == CS_HelloSent) || (cstate == CS_Active))) {
1717                 actionstream << "Server: got SRP _M packet in wrong state "
1718                         << cstate << " from "
1719                         << getPeerAddress(pkt->getPeerId()).serializeString()
1720                         << ". Ignoring." << std::endl;
1721                 return;
1722         }
1723
1724         if (client->chosen_mech != AUTH_MECHANISM_SRP &&
1725                         client->chosen_mech != AUTH_MECHANISM_LEGACY_PASSWORD) {
1726                 actionstream << "Server: got SRP _M packet, while auth"
1727                         << "is going on with mech " << client->chosen_mech
1728                         << " from " << getPeerAddress(pkt->getPeerId()).serializeString()
1729                         << " (wantSudo=" << wantSudo << "). Denying." << std::endl;
1730                 if (wantSudo) {
1731                         DenySudoAccess(pkt->getPeerId());
1732                         return;
1733                 }
1734
1735                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1736                 return;
1737         }
1738
1739         std::string bytes_M;
1740         *pkt >> bytes_M;
1741
1742         if (srp_verifier_get_session_key_length((SRPVerifier *) client->auth_data)
1743                         != bytes_M.size()) {
1744                 actionstream << "Server: User " << client->getName()
1745                         << " at " << getPeerAddress(pkt->getPeerId()).serializeString()
1746                         << " sent bytes_M with invalid length " << bytes_M.size() << std::endl;
1747                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_UNEXPECTED_DATA);
1748                 return;
1749         }
1750
1751         unsigned char *bytes_HAMK = 0;
1752
1753         srp_verifier_verify_session((SRPVerifier *) client->auth_data,
1754                 (unsigned char *)bytes_M.c_str(), &bytes_HAMK);
1755
1756         if (!bytes_HAMK) {
1757                 if (wantSudo) {
1758                         actionstream << "Server: User " << client->getName()
1759                                 << " at " << getPeerAddress(pkt->getPeerId()).serializeString()
1760                                 << " tried to change their password, but supplied wrong"
1761                                 << " (SRP) password for authentication." << std::endl;
1762                         DenySudoAccess(pkt->getPeerId());
1763                         return;
1764                 }
1765
1766                 std::string ip = getPeerAddress(pkt->getPeerId()).serializeString();
1767                 actionstream << "Server: User " << client->getName()
1768                         << " at " << ip
1769                         << " supplied wrong password (auth mechanism: SRP)."
1770                         << std::endl;
1771                 m_script->on_auth_failure(client->getName(), ip);
1772                 DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_WRONG_PASSWORD);
1773                 return;
1774         }
1775
1776         if (client->create_player_on_auth_success) {
1777                 std::string playername = client->getName();
1778                 m_script->createAuth(playername, client->enc_pwd);
1779
1780                 std::string checkpwd; // not used, but needed for passing something
1781                 if (!m_script->getAuth(playername, &checkpwd, NULL)) {
1782                         actionstream << "Server: " << playername << " cannot be authenticated"
1783                                 << " (auth handler does not work?)" << std::endl;
1784                         DenyAccess(pkt->getPeerId(), SERVER_ACCESSDENIED_SERVER_FAIL);
1785                         return;
1786                 }
1787                 client->create_player_on_auth_success = false;
1788         }
1789
1790         acceptAuth(pkt->getPeerId(), wantSudo);
1791 }
1792
1793 /*
1794  * Mod channels
1795  */
1796
1797 void Server::handleCommand_ModChannelJoin(NetworkPacket *pkt)
1798 {
1799         std::string channel_name;
1800         *pkt >> channel_name;
1801
1802         NetworkPacket resp_pkt(TOCLIENT_MODCHANNEL_SIGNAL, 1 + 2 + channel_name.size(),
1803                 pkt->getPeerId());
1804
1805         // Send signal to client to notify join succeed or not
1806         if (g_settings->getBool("enable_mod_channels") &&
1807                         m_modchannel_mgr->joinChannel(channel_name, pkt->getPeerId())) {
1808                 resp_pkt << (u8) MODCHANNEL_SIGNAL_JOIN_OK;
1809                 infostream << "Peer " << pkt->getPeerId() << " joined channel " << channel_name
1810                                 << std::endl;
1811         }
1812         else {
1813                 resp_pkt << (u8)MODCHANNEL_SIGNAL_JOIN_FAILURE;
1814                 infostream << "Peer " << pkt->getPeerId() << " tried to join channel "
1815                         << channel_name << ", but was already registered." << std::endl;
1816         }
1817         resp_pkt << channel_name;
1818         Send(&resp_pkt);
1819 }
1820
1821 void Server::handleCommand_ModChannelLeave(NetworkPacket *pkt)
1822 {
1823         std::string channel_name;
1824         *pkt >> channel_name;
1825
1826         NetworkPacket resp_pkt(TOCLIENT_MODCHANNEL_SIGNAL, 1 + 2 + channel_name.size(),
1827                 pkt->getPeerId());
1828
1829         // Send signal to client to notify join succeed or not
1830         if (g_settings->getBool("enable_mod_channels") &&
1831                         m_modchannel_mgr->leaveChannel(channel_name, pkt->getPeerId())) {
1832                 resp_pkt << (u8)MODCHANNEL_SIGNAL_LEAVE_OK;
1833                 infostream << "Peer " << pkt->getPeerId() << " left channel " << channel_name
1834                                 << std::endl;
1835         } else {
1836                 resp_pkt << (u8) MODCHANNEL_SIGNAL_LEAVE_FAILURE;
1837                 infostream << "Peer " << pkt->getPeerId() << " left channel " << channel_name
1838                                 << ", but was not registered." << std::endl;
1839         }
1840         resp_pkt << channel_name;
1841         Send(&resp_pkt);
1842 }
1843
1844 void Server::handleCommand_ModChannelMsg(NetworkPacket *pkt)
1845 {
1846         std::string channel_name, channel_msg;
1847         *pkt >> channel_name >> channel_msg;
1848
1849         verbosestream << "Mod channel message received from peer " << pkt->getPeerId()
1850                         << " on channel " << channel_name << " message: " << channel_msg << std::endl;
1851
1852         // If mod channels are not enabled, discard message
1853         if (!g_settings->getBool("enable_mod_channels")) {
1854                 return;
1855         }
1856
1857         // If channel not registered, signal it and ignore message
1858         if (!m_modchannel_mgr->channelRegistered(channel_name)) {
1859                 NetworkPacket resp_pkt(TOCLIENT_MODCHANNEL_SIGNAL, 1 + 2 + channel_name.size(),
1860                         pkt->getPeerId());
1861                 resp_pkt << (u8)MODCHANNEL_SIGNAL_CHANNEL_NOT_REGISTERED << channel_name;
1862                 Send(&resp_pkt);
1863                 return;
1864         }
1865
1866         // @TODO: filter, rate limit
1867
1868         broadcastModChannelMessage(channel_name, channel_msg, pkt->getPeerId());
1869 }