src/packet.c

   1 /*
   2  *  ircd-ratbox: A slightly useful ircd.
   3  *  packet.c: Packet handlers.
   4  *
   5  *  Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
   6  *  Copyright (C) 1996-2002 Hybrid Development Team
   7  *  Copyright (C) 2002-2005 ircd-ratbox development team
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software
  21  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
  22  *  USA
  23  */
  24 #include "stdinc.h"
  25 #include "tools.h"
  26 #include "commio.h"
  27 #include "s_conf.h"
  28 #include "s_serv.h"
  29 #include "client.h"
  30 #include "common.h"
  31 #include "ircd.h"
  32 #include "parse.h"
  33 #include "packet.h"
  34 #include "irc_string.h"
  35 #include "memory.h"
  36 #include "hook.h"
  37 #include "send.h"
  38
  39 static char readBuf[READBUF_SIZE];
  40 static void client_dopacket(struct Client *client_p, char *buffer, size_t length);
  41
  42
  43 /*
  44  * parse_client_queued - parse client queued messages
  45  */
  46 static void
  47 parse_client_queued(struct Client *client_p)
  48 {
  49         int dolen = 0;
  50         int checkflood = 1;
  51
  52         if(IsAnyDead(client_p))
  53                 return;
  54
  55         if(IsUnknown(client_p))
  56         {
  57                 int i = 0;
  58
  59                 for (;;)
  60                 {
  61                         /* rate unknown clients at MAX_FLOOD per loop */
  62                         if(i >= MAX_FLOOD)
  63                                 break;
  64
  65                         dolen = linebuf_get(&client_p->localClient->
  66                                             buf_recvq, readBuf, READBUF_SIZE,
  67                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
  68
  69                         if(dolen <= 0 || IsDead(client_p))
  70                                 break;
  71
  72                         client_dopacket(client_p, readBuf, dolen);
  73                         i++;
  74
  75                         /* He's dead cap'n */
  76                         if(IsAnyDead(client_p))
  77                                 return;
  78                         /* if theyve dropped out of the unknown state, break and move
  79                          * to the parsing for their appropriate status.  --fl
  80                          */
  81                         if(!IsUnknown(client_p))
  82                                 break;
  83
  84                 }
  85         }
  86
  87         if(IsAnyServer(client_p) || IsExemptFlood(client_p))
  88         {
  89                 while (!IsAnyDead(client_p) && (dolen = linebuf_get(&client_p->localClient->buf_recvq,
  90                                            readBuf, READBUF_SIZE, LINEBUF_COMPLETE,
  91                                            LINEBUF_PARSED)) > 0)
  92                 {
  93                         client_dopacket(client_p, readBuf, dolen);
  94                 }
  95         }
  96         else if(IsClient(client_p))
  97         {
  98
  99                 if(IsOper(client_p) && ConfigFileEntry.no_oper_flood)
 100                         checkflood = 0;
 101                 /*
 102                  * Handle flood protection here - if we exceed our flood limit on
 103                  * messages in this loop, we simply drop out of the loop prematurely.
 104                  *   -- adrian
 105                  */
 106                 for (;;)
 107                 {
 108                         /* This flood protection works as follows:
 109                          *
 110                          * A client is given allow_read lines to send to the server.  Every
 111                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 112                          * is decreased by 1 every time flood_recalc is called.
 113                          *
 114                          * Thus a client can 'burst' allow_read lines to the server, any
 115                          * excess lines will be parsed one per flood_recalc() call.
 116                          *
 117                          * Therefore a client will be penalised more if they keep flooding,
 118                          * as sent_parsed will always hover around the allow_read limit
 119                          * and no 'bursts' will be permitted.
 120                          */
 121                         if(checkflood)
 122                         {
 123                                 if(client_p->localClient->sent_parsed >= client_p->localClient->allow_read)
 124                                         break;
 125                         }
 126
 127                         /* allow opers 4 times the amount of messages as users. why 4?
 128                          * why not. :) --fl_
 129                          */
 130                         else if(client_p->localClient->sent_parsed >= (4 * client_p->localClient->allow_read))
 131                                 break;
 132
 133                         dolen = linebuf_get(&client_p->localClient->
 134                                             buf_recvq, readBuf, READBUF_SIZE,
 135                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 136
 137                         if(!dolen)
 138                                 break;
 139
 140                         client_dopacket(client_p, readBuf, dolen);
 141                         if(IsAnyDead(client_p))
 142                                 return;
 143                         client_p->localClient->sent_parsed++;
 144                 }
 145         }
 146 }
 147
 148 /* flood_endgrace()
 149  *
 150  * marks the end of the clients grace period
 151  */
 152 void
 153 flood_endgrace(struct Client *client_p)
 154 {
 155         SetFloodDone(client_p);
 156
 157         /* Drop their flood limit back down */
 158         client_p->localClient->allow_read = MAX_FLOOD;
 159
 160         /* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
 161          * so reset it.
 162          */
 163         client_p->localClient->sent_parsed = 0;
 164 }
 165
 166 /*
 167  * flood_recalc
 168  *
 169  * recalculate the number of allowed flood lines. this should be called
 170  * once a second on any given client. We then attempt to flush some data.
 171  */
 172 void
 173 flood_recalc(int fd, void *data)
 174 {
 175         struct Client *client_p = data;
 176         struct LocalUser *lclient_p = client_p->localClient;
 177
 178         /* This can happen in the event that the client detached. */
 179         if(!lclient_p)
 180                 return;
 181
 182         /* allow a bursting client their allocation per second, allow
 183          * a client whos flooding an extra 2 per second
 184          */
 185         if(IsFloodDone(client_p))
 186                 lclient_p->sent_parsed -= 2;
 187         else
 188                 lclient_p->sent_parsed = 0;
 189
 190         if(lclient_p->sent_parsed < 0)
 191                 lclient_p->sent_parsed = 0;
 192
 193         if(--lclient_p->actually_read < 0)
 194                 lclient_p->actually_read = 0;
 195
 196         parse_client_queued(client_p);
 197
 198         if(IsAnyDead(client_p))
 199                 return;
 200
 201         /* and finally, reset the flood check */
 202         comm_setflush(fd, 1000, flood_recalc, client_p);
 203 }
 204
 205 /*
 206  * read_ctrl_packet - Read a 'packet' of data from a servlink control
 207  *                    link and process it.
 208  */
 209 void
 210 read_ctrl_packet(int fd, void *data)
 211 {
 212         struct Client *server = data;
 213         struct LocalUser *lserver = server->localClient;
 214         struct SlinkRpl *reply;
 215         int length = 0;
 216         unsigned char tmp[2];
 217         unsigned char *len = tmp;
 218         struct SlinkRplDef *replydef;
 219 #ifdef USE_IODEBUG_HOOKS
 220         hook_data_int hdata;
 221 #endif
 222
 223         s_assert(lserver != NULL);
 224         if(IsAnyDead(server))
 225                 return;
 226
 227         reply = &lserver->slinkrpl;
 228
 229
 230         if(!reply->command)
 231         {
 232                 reply->gotdatalen = 0;
 233                 reply->readdata = 0;
 234                 reply->data = NULL;
 235
 236                 length = read(fd, tmp, 1);
 237
 238                 if(length <= 0)
 239                 {
 240                         if((length == -1) && ignoreErrno(errno))
 241                                 goto nodata;
 242                         error_exit_client(server, length);
 243                         return;
 244                 }
 245
 246                 reply->command = tmp[0];
 247         }
 248
 249         for (replydef = slinkrpltab; replydef->handler; replydef++)
 250         {
 251                 if((int)replydef->replyid == reply->command)
 252                         break;
 253         }
 254
 255         /* we should be able to trust a local slink process...
 256          * and if it sends an invalid command, that's a bug.. */
 257         s_assert(replydef->handler);
 258
 259         if((replydef->flags & SLINKRPL_FLAG_DATA) && (reply->gotdatalen < 2))
 260         {
 261                 /* we need a datalen u16 which we don't have yet... */
 262                 length = read(fd, len, (2 - reply->gotdatalen));
 263                 if(length <= 0)
 264                 {
 265                         if((length == -1) && ignoreErrno(errno))
 266                                 goto nodata;
 267                         error_exit_client(server, length);
 268                         return;
 269                 }
 270
 271                 if(reply->gotdatalen == 0)
 272                 {
 273                         reply->datalen = *len << 8;
 274                         reply->gotdatalen++;
 275                         length--;
 276                         len++;
 277                 }
 278                 if(length && (reply->gotdatalen == 1))
 279                 {
 280                         reply->datalen |= *len;
 281                         reply->gotdatalen++;
 282                         if(reply->datalen > 0)
 283                                 reply->data = MyMalloc(reply->datalen);
 284                 }
 285
 286                 if(reply->gotdatalen < 2)
 287                         return; /* wait for more data */
 288         }
 289
 290         if(reply->readdata < reply->datalen)    /* try to get any remaining data */
 291         {
 292                 length = read(fd, (reply->data + reply->readdata),
 293                               (reply->datalen - reply->readdata));
 294                 if(length <= 0)
 295                 {
 296                         if((length == -1) && ignoreErrno(errno))
 297                                 goto nodata;
 298                         error_exit_client(server, length);
 299                         return;
 300                 }
 301
 302                 reply->readdata += length;
 303                 if(reply->readdata < reply->datalen)
 304                         return; /* wait for more data */
 305         }
 306
 307 #ifdef USE_IODEBUG_HOOKS
 308         hdata.client = server;
 309         hdata.arg1 = NULL;
 310         hdata.arg2 = reply->command;
 311         hdata.data = NULL;
 312         call_hook(h_iorecvctrl_id, &hdata);
 313 #endif
 314
 315         /* we now have the command and any data, pass it off to the handler */
 316         (*replydef->handler) (reply->command, reply->datalen, reply->data, server);
 317
 318         /* reset SlinkRpl */
 319         if(reply->datalen > 0)
 320                 MyFree(reply->data);
 321         reply->command = 0;
 322
 323         if(IsAnyDead(server))
 324                 return;
 325
 326       nodata:
 327         /* If we get here, we need to register for another COMM_SELECT_READ */
 328         comm_setselect(fd, FDLIST_SERVER, COMM_SELECT_READ, read_ctrl_packet, server, 0);
 329 }
 330
 331 /*
 332  * read_packet - Read a 'packet' of data from a connection and process it.
 333  */
 334 void
 335 read_packet(int fd, void *data)
 336 {
 337         struct Client *client_p = data;
 338         struct LocalUser *lclient_p = client_p->localClient;
 339         int length = 0;
 340         int lbuf_len;
 341
 342         int binary = 0;
 343 #ifdef USE_IODEBUG_HOOKS
 344         hook_data_int hdata;
 345 #endif
 346         if(IsAnyDead(client_p))
 347                 return;
 348
 349         /*
 350          * Read some data. We *used to* do anti-flood protection here, but
 351          * I personally think it makes the code too hairy to make sane.
 352          *     -- adrian
 353          */
 354         length = read(client_p->localClient->fd, readBuf, READBUF_SIZE);
 355
 356         if(length <= 0)
 357         {
 358                 if((length == -1) && ignoreErrno(errno))
 359                 {
 360                         comm_setselect(client_p->localClient->fd, FDLIST_IDLECLIENT,
 361                                        COMM_SELECT_READ, read_packet, client_p, 0);
 362                         return;
 363                 }
 364                 error_exit_client(client_p, length);
 365                 return;
 366         }
 367
 368 #ifdef USE_IODEBUG_HOOKS
 369         hdata.client = client_p;
 370         hdata.arg1 = readBuf;
 371         hdata.arg2 = length;
 372         call_hook(h_iorecv_id, &hdata);
 373 #endif
 374
 375         if(client_p->localClient->lasttime < CurrentTime)
 376                 client_p->localClient->lasttime = CurrentTime;
 377         client_p->flags &= ~FLAGS_PINGSENT;
 378
 379         /*
 380          * Before we even think of parsing what we just read, stick
 381          * it on the end of the receive queue and do it when its
 382          * turn comes around.
 383          */
 384         if(IsHandshake(client_p) || IsUnknown(client_p))
 385                 binary = 1;
 386
 387         lbuf_len = linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 388
 389         lclient_p->actually_read += lbuf_len;
 390
 391         if(IsAnyDead(client_p))
 392                 return;
 393
 394         /* Attempt to parse what we have */
 395         parse_client_queued(client_p);
 396
 397         if(IsAnyDead(client_p))
 398                 return;
 399
 400         /* Check to make sure we're not flooding */
 401         if(!IsAnyServer(client_p) &&
 402            (linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood))
 403         {
 404                 if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 405                 {
 406                         exit_client(client_p, client_p, client_p, "Excess Flood");
 407                         return;
 408                 }
 409         }
 410
 411         /* If we get here, we need to register for another COMM_SELECT_READ */
 412         if(PARSE_AS_SERVER(client_p))
 413         {
 414                 comm_setselect(client_p->localClient->fd, FDLIST_SERVER, COMM_SELECT_READ,
 415                               read_packet, client_p, 0);
 416         }
 417         else
 418         {
 419                 comm_setselect(client_p->localClient->fd, FDLIST_IDLECLIENT,
 420                                COMM_SELECT_READ, read_packet, client_p, 0);
 421         }
 422 }
 423
 424 /*
 425  * client_dopacket - copy packet to client buf and parse it
 426  *      client_p - pointer to client structure for which the buffer data
 427  *             applies.
 428  *      buffer - pointr to the buffer containing the newly read data
 429  *      length - number of valid bytes of data in the buffer
 430  *
 431  * Note:
 432  *      It is implicitly assumed that dopacket is called only
 433  *      with client_p of "local" variation, which contains all the
 434  *      necessary fields (buffer etc..)
 435  */
 436 void
 437 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 438 {
 439         s_assert(client_p != NULL);
 440         s_assert(buffer != NULL);
 441
 442         if(client_p == NULL || buffer == NULL)
 443                 return;
 444         if(IsAnyDead(client_p))
 445                 return;
 446         /*
 447          * Update messages received
 448          */
 449         ++me.localClient->receiveM;
 450         ++client_p->localClient->receiveM;
 451
 452         /*
 453          * Update bytes received
 454          */
 455         client_p->localClient->receiveB += length;
 456
 457         if(client_p->localClient->receiveB > 1023)
 458         {
 459                 client_p->localClient->receiveK += (client_p->localClient->receiveB >> 10);
 460                 client_p->localClient->receiveB &= 0x03ff;      /* 2^10 = 1024, 3ff = 1023 */
 461         }
 462
 463         me.localClient->receiveB += length;
 464
 465         if(me.localClient->receiveB > 1023)
 466         {
 467                 me.localClient->receiveK += (me.localClient->receiveB >> 10);
 468                 me.localClient->receiveB &= 0x03ff;
 469         }
 470
 471         parse(client_p, buffer, buffer + length);
 472 }