src/ngircd/irc-server.c

   1 /*
   2  * ngIRCd -- The Next Generation IRC Daemon
   3  * Copyright (c)2001-2022 Alexander Barton (alex@barton.de) and Contributors.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  * Please read the file COPYING, README and AUTHORS for more information.
  10  */
  11
  12 #include "portab.h"
  13
  14 /**
  15  * @file
  16  * IRC commands for server links
  17  */
  18
  19 #include <assert.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <strings.h>
  24
  25 #include "conn-func.h"
  26 #include "conn-zip.h"
  27 #include "conf.h"
  28 #include "channel.h"
  29 #include "log.h"
  30 #include "messages.h"
  31 #include "parse.h"
  32 #include "numeric.h"
  33 #include "ngircd.h"
  34 #include "irc.h"
  35 #include "irc-channel.h"
  36 #include "irc-info.h"
  37 #include "irc-write.h"
  38 #include "op.h"
  39
  40 #include "irc-server.h"
  41
  42 /**
  43  * Handler for the IRC "SERVER" command.
  44  *
  45  * @param Client The client from which this command has been received.
  46  * @param Req Request structure with prefix and all parameters.
  47  * @return CONNECTED or DISCONNECTED.
  48  */
  49 GLOBAL bool
  50 IRC_SERVER( CLIENT *Client, REQUEST *Req )
  51 {
  52         char str[100];
  53         CLIENT *from, *c;
  54         int i;
  55
  56         assert( Client != NULL );
  57         assert( Req != NULL );
  58
  59         /* Return an error if this is not a local client */
  60         if (Client_Conn(Client) <= NONE)
  61                 return IRC_WriteErrClient(Client, ERR_UNKNOWNCOMMAND_MSG,
  62                                           Client_ID(Client), Req->command);
  63
  64         if (Client_Type(Client) == CLIENT_GOTPASS ||
  65             Client_Type(Client) == CLIENT_GOTPASS_2813) {
  66                 /* We got a PASS command from the peer, and now a SERVER
  67                  * command: the peer tries to register itself as a server. */
  68                 LogDebug("Connection %d: got SERVER command (new server link) ...",
  69                         Client_Conn(Client));
  70
  71                 if (Req->argc != 2 && Req->argc != 3)
  72                         return IRC_WriteErrClient(Client, ERR_NEEDMOREPARAMS_MSG,
  73                                                   Client_ID(Client),
  74                                                   Req->command);
  75
  76                 /* Get configuration index of new remote server ... */
  77                 for (i = 0; i < MAX_SERVERS; i++)
  78                         if (strcasecmp(Req->argv[0], Conf_Server[i].name) == 0)
  79                                 break;
  80
  81                 /* Make sure the remote server is configured here */
  82                 if (i >= MAX_SERVERS) {
  83                         Log(LOG_ERR,
  84                             "Connection %d: Server \"%s\" not configured here!",
  85                             Client_Conn(Client), Req->argv[0]);
  86                         Conn_Close(Client_Conn(Client), NULL,
  87                                    "Server not configured here", true);
  88                         return DISCONNECTED;
  89                 }
  90
  91                 /* Check server password */
  92                 if (strcmp(Conn_Password(Client_Conn(Client)),
  93                     Conf_Server[i].pwd_in) != 0) {
  94                         Log(LOG_ERR,
  95                             "Connection %d: Got bad password from server \"%s\"!",
  96                             Client_Conn(Client), Req->argv[0]);
  97                         Conn_Close(Client_Conn(Client), NULL,
  98                                    "Bad password", true);
  99                         return DISCONNECTED;
 100                 }
 101
 102                 /* Is there a registered server with this ID? */
 103                 if (!Client_CheckID(Client, Req->argv[0]))
 104                         return DISCONNECTED;
 105
 106                 /* Mark this connection as belonging to an configured server */
 107                 if (!Conf_SetServer(i, Client_Conn(Client)))
 108                         return DISCONNECTED;
 109
 110                 Client_SetID( Client, Req->argv[0] );
 111                 Client_SetHops( Client, 1 );
 112                 Client_SetInfo( Client, Req->argv[Req->argc - 1] );
 113
 114                 /* Is this server registering on our side, or are we connecting to
 115                  * a remote server? */
 116                 if (Client_Token(Client) != TOKEN_OUTBOUND) {
 117                         /* Incoming connection, send user/pass */
 118                         if (!IRC_WriteStrClient(Client, "PASS %s %s",
 119                                                 Conf_Server[i].pwd_out,
 120                                                 NGIRCd_ProtoID)
 121                             || !IRC_WriteStrClient(Client, "SERVER %s 1 :%s",
 122                                                    Conf_ServerName,
 123                                                    Conf_ServerInfo)) {
 124                                     Conn_Close(Client_Conn(Client),
 125                                                "Unexpected server behavior!",
 126                                                NULL, false);
 127                                     return DISCONNECTED;
 128                         }
 129                         Client_SetIntroducer(Client, Client);
 130                         Client_SetToken(Client, 1);
 131                 } else {
 132                         /* outgoing connect, we already sent a SERVER and PASS
 133                          * command to the peer */
 134                         Client_SetToken(Client, atoi(Req->argv[1]));
 135                 }
 136
 137                 /* Check protocol level */
 138                 if (Client_Type(Client) == CLIENT_GOTPASS) {
 139                         /* We got a "simple" PASS command, so the peer is
 140                          * using the protocol as defined in RFC 1459. */
 141                         if (! (Conn_Options(Client_Conn(Client)) & CONN_RFC1459))
 142                                 Log(LOG_INFO,
 143                                     "Switching connection %d (\"%s\") to RFC 1459 compatibility mode.",
 144                                     Client_Conn(Client), Client_ID(Client));
 145                         Conn_SetOption(Client_Conn(Client), CONN_RFC1459);
 146                 }
 147
 148                 Client_SetType(Client, CLIENT_UNKNOWNSERVER);
 149
 150 #ifdef ZLIB
 151                 if (Client_HasFlag(Client, 'Z')
 152                     && !Zip_InitConn(Client_Conn(Client))) {
 153                         Conn_Close(Client_Conn(Client),
 154                                    "Can't initialize compression (zlib)!",
 155                                    NULL, false );
 156                         return DISCONNECTED;
 157                 }
 158 #endif
 159
 160 #ifdef IRCPLUS
 161                 if (Client_HasFlag(Client, 'H')) {
 162                         LogDebug("Peer supports IRC+ extended server handshake ...");
 163                         if (!IRC_Send_ISUPPORT(Client))
 164                                 return DISCONNECTED;
 165                         return IRC_WriteStrClient(Client, RPL_ENDOFMOTD_MSG,
 166                                                   Client_ID(Client));
 167                 } else {
 168 #endif
 169                         if (Conf_MaxNickLength != CLIENT_NICK_LEN_DEFAULT)
 170                                 Log(LOG_CRIT,
 171                                     "Attention: this server uses a non-standard nick length, but the peer doesn't support the IRC+ extended server handshake!");
 172 #ifdef IRCPLUS
 173                 }
 174 #endif
 175
 176                 return IRC_Num_ENDOFMOTD(Client, Req);
 177         }
 178         else if( Client_Type( Client ) == CLIENT_SERVER )
 179         {
 180                 /* New server is being introduced to the network */
 181
 182                 if (Req->argc != 4)
 183                         return IRC_WriteErrClient(Client, ERR_NEEDMOREPARAMS_MSG,
 184                                                   Client_ID(Client), Req->command);
 185
 186                 /* check for existing server with same ID */
 187                 if (!Client_CheckID(Client, Req->argv[0]))
 188                         return DISCONNECTED;
 189
 190                 if (!Req->prefix) {
 191                         /* We definitely need a prefix here! */
 192                         Log(LOG_ALERT, "Got SERVER command without prefix! (on connection %d)",
 193                             Client_Conn(Client));
 194                         Conn_Close(Client_Conn(Client), NULL,
 195                                    "SERVER command without prefix", true);
 196                         return DISCONNECTED;
 197                 }
 198
 199                 from = Client_Search( Req->prefix );
 200                 if (! from) {
 201                         /* Uh, Server, that introduced the new server is unknown?! */
 202                         Log(LOG_ALERT,
 203                             "Unknown ID in prefix of SERVER: \"%s\"! (on connection %d)",
 204                             Req->prefix, Client_Conn(Client));
 205                         Conn_Close(Client_Conn(Client), NULL,
 206                                    "Unknown ID in prefix of SERVER", true);
 207                         return DISCONNECTED;
 208                 }
 209
 210                 c = Client_NewRemoteServer(Client, Req->argv[0], from,
 211                                            atoi(Req->argv[1]), atoi(Req->argv[2]),
 212                                            Req->argv[3], true);
 213                 if (!c) {
 214                         Log(LOG_ALERT,
 215                             "Can't create client structure for server! (on connection %d)",
 216                             Client_Conn(Client));
 217                         Conn_Close(Client_Conn(Client), NULL,
 218                                    "Can't allocate client structure for remote server",
 219                                    true);
 220                         return DISCONNECTED;
 221                 }
 222
 223                 if (Client_Hops(c) > 1 && Req->prefix[0])
 224                         snprintf(str, sizeof(str), "connected to %s, ",
 225                                  Client_ID(from));
 226                 else
 227                         strcpy(str, "");
 228                 Log(LOG_NOTICE|LOG_snotice,
 229                     "Server \"%s\" registered (via %s, %s%d hop%s).",
 230                     Client_ID(c), Client_ID(Client), str, Client_Hops(c),
 231                     Client_Hops(c) > 1 ? "s": "" );
 232
 233                 /* notify other servers */
 234                 IRC_WriteStrServersPrefix(Client, from, "SERVER %s %d %d :%s",
 235                                           Client_ID(c), Client_Hops(c) + 1,
 236                                           Client_MyToken(c), Client_Info(c));
 237
 238                 return CONNECTED;
 239         } else
 240                 return IRC_WriteErrClient(Client, ERR_NEEDMOREPARAMS_MSG,
 241                                           Client_ID(Client), Req->command);
 242 } /* IRC_SERVER */
 243
 244 /*
 245  * Handler for the IRC "NJOIN" command.
 246  *
 247  * @param Client The client from which this command has been received.
 248  * @param Req Request structure with prefix and all parameters.
 249  * @return CONNECTED or DISCONNECTED.
 250  */
 251 GLOBAL bool
 252 IRC_NJOIN( CLIENT *Client, REQUEST *Req )
 253 {
 254         char nick_in[COMMAND_LEN], nick_out[COMMAND_LEN], *channame, *ptr, modes[8];
 255         bool is_owner, is_chanadmin, is_op, is_halfop, is_voiced;
 256         CHANNEL *chan;
 257         CLIENT *c;
 258
 259         assert(Client != NULL);
 260         assert(Req != NULL);
 261
 262         strlcpy(nick_in, Req->argv[1], sizeof(nick_in));
 263         strcpy(nick_out, "");
 264
 265         channame = Req->argv[0];
 266
 267         ptr = strtok(nick_in, ",");
 268         while (ptr) {
 269                 is_owner = is_chanadmin = is_op = is_halfop = is_voiced = false;
 270
 271                 /* cut off prefixes */
 272                 while ((*ptr == '~') || (*ptr == '&') || (*ptr == '@') ||
 273                        (*ptr == '%') || (*ptr == '+')) {
 274                         if (*ptr == '~')
 275                                 is_owner = true;
 276                         if (*ptr == '&')
 277                                 is_chanadmin = true;
 278                         if (*ptr == '@')
 279                                 is_op = true;
 280                         if (*ptr == '%')
 281                                 is_halfop = true;
 282                         if (*ptr == '+')
 283                                 is_voiced = true;
 284                         ptr++;
 285                 }
 286
 287                 c = Client_Search(ptr);
 288                 if (!c) {
 289                         /* Client not found? */
 290                         Log(LOG_ERR,
 291                             "Got NJOIN for unknown nick \"%s\" for channel \"%s\"!",
 292                             ptr, channame);
 293                         goto skip_njoin;
 294                 }
 295
 296                 if (!Channel_Join(c, channame)) {
 297                         /* Failed to join channel. Ooops!? */
 298                         Log(LOG_ALERT,
 299                             "Failed to join client \"%s\" to channel \"%s\" (NJOIN): killing it!",
 300                             ptr, channame);
 301                         IRC_KillClient(NULL, NULL, ptr, "Internal NJOIN error!");
 302                         LogDebug("... done.");
 303                         goto skip_njoin;
 304                 }
 305
 306                 chan = Channel_Search(channame);
 307                 assert(chan != NULL);
 308
 309                 if (is_owner)
 310                         Channel_UserModeAdd(chan, c, 'q');
 311                 if (is_chanadmin)
 312                         Channel_UserModeAdd(chan, c, 'a');
 313                 if (is_op)
 314                         Channel_UserModeAdd(chan, c, 'o');
 315                 if (is_halfop)
 316                         Channel_UserModeAdd(chan, c, 'h');
 317                 if (is_voiced)
 318                         Channel_UserModeAdd(chan, c, 'v');
 319
 320                 /* Announce client to the channel */
 321                 IRC_WriteStrChannelPrefix(Client, chan, c, false,
 322                                           "JOIN :%s", channame);
 323
 324                 /* If the client is connected to this server, it was remotely
 325                  * joined to the channel by another server/service: So send
 326                  * TOPIC and NAMES messages like on a regular JOIN command! */
 327                 if(Client_Conn(c) != NONE)
 328                         IRC_Send_Channel_Info(c, chan);
 329
 330                 /* Announce "channel user modes" to the channel, if any */
 331                 strlcpy(modes, Channel_UserModes(chan, c), sizeof(modes));
 332                 if (modes[0])
 333                         IRC_WriteStrChannelPrefix(Client, chan, Client, false,
 334                                                   "MODE %s +%s %s", channame,
 335                                                   modes, Client_ID(c));
 336
 337                 /* Build nick list for forwarding command */
 338                 if (nick_out[0] != '\0')
 339                         strlcat(nick_out, ",", sizeof(nick_out));
 340                 if (is_owner)
 341                         strlcat(nick_out, "~", sizeof(nick_out));
 342                 if (is_chanadmin)
 343                         strlcat(nick_out, "&", sizeof(nick_out));
 344                 if (is_op)
 345                         strlcat(nick_out, "@", sizeof(nick_out));
 346                 if (is_halfop)
 347                         strlcat(nick_out, "%", sizeof(nick_out));
 348                 if (is_voiced)
 349                         strlcat(nick_out, "+", sizeof(nick_out));
 350                 strlcat(nick_out, ptr, sizeof(nick_out));
 351
 352               skip_njoin:
 353                 /* Get next nick, if any ... */
 354                 ptr = strtok(NULL, ",");
 355         }
 356
 357         /* forward to other servers */
 358         if (nick_out[0] != '\0')
 359                 IRC_WriteStrServersPrefix(Client, Client_ThisServer(),
 360                                           "NJOIN %s :%s", Req->argv[0], nick_out);
 361
 362         return CONNECTED;
 363 } /* IRC_NJOIN */
 364
 365 /**
 366  * Handler for the IRC "SQUIT" command.
 367  *
 368  * @param Client The client from which this command has been received.
 369  * @param Req Request structure with prefix and all parameters.
 370  * @return CONNECTED or DISCONNECTED.
 371  */
 372 GLOBAL bool
 373 IRC_SQUIT(CLIENT * Client, REQUEST * Req)
 374 {
 375         char msg[COMMAND_LEN], logmsg[COMMAND_LEN];
 376         CLIENT *from, *target;
 377         CONN_ID con, client_con;
 378         int loglevel;
 379
 380         assert(Client != NULL);
 381         assert(Req != NULL);
 382
 383         if (Client_Type(Client) != CLIENT_SERVER
 384             && !Client_HasMode(Client, 'o'))
 385                 return Op_NoPrivileges(Client, Req);
 386
 387         if (Client_Type(Client) == CLIENT_SERVER && Req->prefix) {
 388                 from = Client_Search(Req->prefix);
 389                 if (Client_Type(from) != CLIENT_SERVER
 390                     && !Op_Check(Client, Req))
 391                         return Op_NoPrivileges(Client, Req);
 392         } else
 393                 from = Client;
 394         if (!from)
 395                 return IRC_WriteErrClient(Client, ERR_NOSUCHNICK_MSG,
 396                                           Client_ID(Client), Req->prefix);
 397
 398         if (Client_Type(Client) == CLIENT_USER)
 399                 loglevel = LOG_NOTICE | LOG_snotice;
 400         else
 401                 loglevel = LOG_DEBUG;
 402         Log(loglevel, "Got SQUIT from %s for \"%s\": \"%s\" ...",
 403             Client_ID(from), Req->argv[0], Req->argv[1]);
 404
 405         target = Client_Search(Req->argv[0]);
 406         if (Client_Type(Client) != CLIENT_SERVER &&
 407             target == Client_ThisServer())
 408                 return Op_NoPrivileges(Client, Req);
 409         if (!target) {
 410                 /* The server is (already) unknown */
 411                 Log(LOG_WARNING,
 412                     "Got SQUIT from %s for unknown server \"%s\"!?",
 413                     Client_ID(Client), Req->argv[0]);
 414                 return CONNECTED;
 415         }
 416
 417         client_con = Client_Conn(Client);
 418         con = Client_Conn(target);
 419
 420         if (Req->argv[1][0])
 421                 if (Client_NextHop(from) != Client || con > NONE)
 422                         snprintf(msg, sizeof(msg), "\"%s\" (SQUIT from %s)",
 423                                  Req->argv[1], Client_ID(from));
 424                 else
 425                         strlcpy(msg, Req->argv[1], sizeof(msg));
 426         else
 427                 snprintf(msg, sizeof(msg), "Got SQUIT from %s",
 428                          Client_ID(from));
 429
 430         if (con > NONE) {
 431                 /* We are directly connected to the target server, so we
 432                  * have to tear down the connection and to inform all the
 433                  * other remaining servers in the network */
 434                 IRC_SendWallops(Client_ThisServer(), Client_ThisServer(),
 435                                 "Received SQUIT %s from %s: %s",
 436                                 Req->argv[0], Client_ID(from),
 437                                 Req->argv[1][0] ? Req->argv[1] : "-");
 438                 Conn_Close(con, NULL, msg, true);
 439                 if (con == client_con)
 440                         return DISCONNECTED;
 441         } else {
 442                 /* This server is not directly connected, so the SQUIT must
 443                  * be forwarded ... */
 444                 if (Client_Type(from) != CLIENT_SERVER) {
 445                         /* The origin is not an IRC server, so don't evaluate
 446                          * this SQUIT but simply forward it */
 447                         IRC_WriteStrClientPrefix(Client_NextHop(target),
 448                             from, "SQUIT %s :%s", Req->argv[0], Req->argv[1]);
 449                 } else {
 450                         /* SQUIT has been generated by another server, so
 451                          * remove the target server from the network! */
 452                         logmsg[0] = '\0';
 453                         if (!strchr(msg, '('))
 454                                 snprintf(logmsg, sizeof(logmsg),
 455                                          "\"%s\" (SQUIT from %s)", Req->argv[1],
 456                                          Client_ID(from));
 457                         Client_Destroy(target, logmsg[0] ? logmsg : msg,
 458                                        msg, false);
 459                 }
 460         }
 461         return CONNECTED;
 462 } /* IRC_SQUIT */
 463
 464 /* -eof- */