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  *  $Id: packet.c 3446 2007-05-14 22:21:16Z jilles $
  25  */
  26 #include "stdinc.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 "hook.h"
  36 #include "send.h"
  37
  38 static char readBuf[READBUF_SIZE];
  39 static void client_dopacket(struct Client *client_p, char *buffer, size_t length);
  40
  41
  42 /*
  43  * parse_client_queued - parse client queued messages
  44  */
  45 static void
  46 parse_client_queued(struct Client *client_p)
  47 {
  48         int dolen = 0;
  49         int checkflood = 1;
  50
  51         if(IsAnyDead(client_p))
  52                 return;
  53
  54         if(IsUnknown(client_p))
  55         {
  56                 for (;;)
  57                 {
  58                         if(client_p->localClient->sent_parsed >= client_p->localClient->allow_read)
  59                                 break;
  60
  61                         dolen = rb_linebuf_get(&client_p->localClient->
  62                                             buf_recvq, readBuf, READBUF_SIZE,
  63                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
  64
  65                         if(dolen <= 0 || IsDead(client_p))
  66                                 break;
  67
  68                         client_dopacket(client_p, readBuf, dolen);
  69                         client_p->localClient->sent_parsed++;
  70
  71                         /* He's dead cap'n */
  72                         if(IsAnyDead(client_p))
  73                                 return;
  74                         /* if theyve dropped out of the unknown state, break and move
  75                          * to the parsing for their appropriate status.  --fl
  76                          */
  77                         if(!IsUnknown(client_p))
  78                         {
  79                                 /* reset their flood limits, they're now
  80                                  * graced to flood
  81                                  */
  82                                 client_p->localClient->sent_parsed = 0;
  83                                 break;
  84                         }
  85
  86                 }
  87         }
  88
  89         if(IsAnyServer(client_p) || IsExemptFlood(client_p))
  90         {
  91                 while (!IsAnyDead(client_p) && (dolen = rb_linebuf_get(&client_p->localClient->buf_recvq,
  92                                            readBuf, READBUF_SIZE, LINEBUF_COMPLETE,
  93                                            LINEBUF_PARSED)) > 0)
  94                 {
  95                         client_dopacket(client_p, readBuf, dolen);
  96                 }
  97         }
  98         else if(IsClient(client_p))
  99         {
 100
 101                 if(IsOper(client_p) && ConfigFileEntry.no_oper_flood)
 102                         checkflood = 0;
 103                 /*
 104                  * Handle flood protection here - if we exceed our flood limit on
 105                  * messages in this loop, we simply drop out of the loop prematurely.
 106                  *   -- adrian
 107                  */
 108                 for (;;)
 109                 {
 110                         /* This flood protection works as follows:
 111                          *
 112                          * A client is given allow_read lines to send to the server.  Every
 113                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 114                          * is decreased by 1 every time flood_recalc is called.
 115                          *
 116                          * Thus a client can 'burst' allow_read lines to the server, any
 117                          * excess lines will be parsed one per flood_recalc() call.
 118                          *
 119                          * Therefore a client will be penalised more if they keep flooding,
 120                          * as sent_parsed will always hover around the allow_read limit
 121                          * and no 'bursts' will be permitted.
 122                          */
 123                         if(checkflood)
 124                         {
 125                                 if(client_p->localClient->sent_parsed >= client_p->localClient->allow_read)
 126                                         break;
 127                         }
 128
 129                         /* allow opers 4 times the amount of messages as users. why 4?
 130                          * why not. :) --fl_
 131                          */
 132                         else if(client_p->localClient->sent_parsed >= (4 * client_p->localClient->allow_read))
 133                                 break;
 134
 135                         dolen = rb_linebuf_get(&client_p->localClient->
 136                                             buf_recvq, readBuf, READBUF_SIZE,
 137                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 138
 139                         if(!dolen)
 140                                 break;
 141
 142                         client_dopacket(client_p, readBuf, dolen);
 143                         if(IsAnyDead(client_p))
 144                                 return;
 145                         client_p->localClient->sent_parsed++;
 146                 }
 147         }
 148 }
 149
 150 /* flood_endgrace()
 151  *
 152  * marks the end of the clients grace period
 153  */
 154 void
 155 flood_endgrace(struct Client *client_p)
 156 {
 157         SetFloodDone(client_p);
 158
 159         /* Drop their flood limit back down */
 160         client_p->localClient->allow_read = MAX_FLOOD;
 161
 162         /* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
 163          * so reset it.
 164          */
 165         client_p->localClient->sent_parsed = 0;
 166 }
 167
 168 /*
 169  * flood_recalc
 170  *
 171  * recalculate the number of allowed flood lines. this should be called
 172  * once a second on any given client. We then attempt to flush some data.
 173  */
 174 void
 175 flood_recalc(void *unused)
 176 {
 177         rb_dlink_node *ptr, *next;
 178         struct Client *client_p;
 179
 180         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 181         {
 182                 client_p = ptr->data;
 183
 184                 if(unlikely(IsMe(client_p)))
 185                         continue;
 186
 187                 if(unlikely(client_p->localClient == NULL))
 188                         continue;
 189
 190                 if(IsFloodDone(client_p))
 191                         client_p->localClient->sent_parsed -= 2;
 192                 else
 193                         client_p->localClient->sent_parsed = 0;
 194
 195                 if(client_p->localClient->sent_parsed < 0)
 196                         client_p->localClient->sent_parsed = 0;
 197
 198                 if(--client_p->localClient->actually_read < 0)
 199                         client_p->localClient->actually_read = 0;
 200
 201                 parse_client_queued(client_p);
 202
 203                 if(unlikely(IsAnyDead(client_p)))
 204                         continue;
 205
 206         }
 207
 208         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 209         {
 210                 client_p = ptr->data;
 211
 212                 if(client_p->localClient == NULL)
 213                         continue;
 214
 215                 client_p->localClient->sent_parsed--;
 216
 217                 if(client_p->localClient->sent_parsed < 0)
 218                         client_p->localClient->sent_parsed = 0;
 219
 220                 if(--client_p->localClient->actually_read < 0)
 221                         client_p->localClient->actually_read = 0;
 222
 223                 parse_client_queued(client_p);
 224         }
 225 }
 226
 227 /*
 228  * read_ctrl_packet - Read a 'packet' of data from a servlink control
 229  *                    link and process it.
 230  */
 231 void
 232 read_ctrl_packet(int fd, void *data)
 233 {
 234         struct Client *server = data;
 235         struct LocalUser *lserver = server->localClient;
 236         struct SlinkRpl *reply;
 237         int length = 0;
 238         unsigned char tmp[2];
 239         unsigned char *len = tmp;
 240         struct SlinkRplDef *replydef;
 241 #ifdef USE_IODEBUG_HOOKS
 242         hook_data_int hdata;
 243 #endif
 244
 245         s_assert(lserver != NULL);
 246         if(IsAnyDead(server))
 247                 return;
 248
 249         reply = &lserver->slinkrpl;
 250
 251
 252         if(!reply->command)
 253         {
 254                 reply->gotdatalen = 0;
 255                 reply->readdata = 0;
 256                 reply->data = NULL;
 257
 258                 length = read(fd, tmp, 1);
 259
 260                 if(length <= 0)
 261                 {
 262                         if((length == -1) && ignoreErrno(errno))
 263                                 goto nodata;
 264                         error_exit_client(server, length);
 265                         return;
 266                 }
 267
 268                 reply->command = tmp[0];
 269         }
 270
 271         for (replydef = slinkrpltab; replydef->handler; replydef++)
 272         {
 273                 if((int)replydef->replyid == reply->command)
 274                         break;
 275         }
 276
 277         /* we should be able to trust a local slink process...
 278          * and if it sends an invalid command, that's a bug.. */
 279         s_assert(replydef->handler);
 280
 281         if((replydef->flags & SLINKRPL_FLAG_DATA) && (reply->gotdatalen < 2))
 282         {
 283                 /* we need a datalen u16 which we don't have yet... */
 284                 length = read(fd, len, (2 - reply->gotdatalen));
 285                 if(length <= 0)
 286                 {
 287                         if((length == -1) && ignoreErrno(errno))
 288                                 goto nodata;
 289                         error_exit_client(server, length);
 290                         return;
 291                 }
 292
 293                 if(reply->gotdatalen == 0)
 294                 {
 295                         reply->datalen = *len << 8;
 296                         reply->gotdatalen++;
 297                         length--;
 298                         len++;
 299                 }
 300                 if(length && (reply->gotdatalen == 1))
 301                 {
 302                         reply->datalen |= *len;
 303                         reply->gotdatalen++;
 304                         if(reply->datalen > 0)
 305                                 reply->data = rb_malloc(reply->datalen);
 306                 }
 307
 308                 if(reply->gotdatalen < 2)
 309                         return; /* wait for more data */
 310         }
 311
 312         if(reply->readdata < reply->datalen)    /* try to get any remaining data */
 313         {
 314                 length = read(fd, (reply->data + reply->readdata),
 315                               (reply->datalen - reply->readdata));
 316                 if(length <= 0)
 317                 {
 318                         if((length == -1) && ignoreErrno(errno))
 319                                 goto nodata;
 320                         error_exit_client(server, length);
 321                         return;
 322                 }
 323
 324                 reply->readdata += length;
 325                 if(reply->readdata < reply->datalen)
 326                         return; /* wait for more data */
 327         }
 328
 329 #ifdef USE_IODEBUG_HOOKS
 330         hdata.client = server;
 331         hdata.arg1 = NULL;
 332         hdata.arg2 = reply->command;
 333         hdata.data = NULL;
 334         call_hook(h_iorecvctrl_id, &hdata);
 335 #endif
 336
 337         /* we now have the command and any data, pass it off to the handler */
 338         (*replydef->handler) (reply->command, reply->datalen, reply->data, server);
 339
 340         /* reset SlinkRpl */
 341         if(reply->datalen > 0)
 342                 rb_free(reply->data);
 343         reply->command = 0;
 344
 345         if(IsAnyDead(server))
 346                 return;
 347
 348       nodata:
 349         /* If we get here, we need to register for another COMM_SELECT_READ */
 350         rb_setselect(fd, FDLIST_SERVER, COMM_SELECT_READ, read_ctrl_packet, server, 0);
 351 }
 352
 353 /*
 354  * read_packet - Read a 'packet' of data from a connection and process it.
 355  */
 356 void
 357 read_packet(int fd, void *data)
 358 {
 359         struct Client *client_p = data;
 360         struct LocalUser *lclient_p = client_p->localClient;
 361         int length = 0;
 362         int lbuf_len;
 363
 364         int binary = 0;
 365 #ifdef USE_IODEBUG_HOOKS
 366         hook_data_int hdata;
 367 #endif
 368         if(IsAnyDead(client_p))
 369                 return;
 370
 371         /*
 372          * Read some data. We *used to* do anti-flood protection here, but
 373          * I personally think it makes the code too hairy to make sane.
 374          *     -- adrian
 375          */
 376         length = client_p->localClient->F->read_impl(client_p->localClient->F, readBuf, READBUF_SIZE);
 377
 378         if(length <= 0)
 379         {
 380                 if((length == -1) && ignoreErrno(errno))
 381                 {
 382                         rb_setselect(client_p->localClient->F->fd, FDLIST_IDLECLIENT,
 383                                        COMM_SELECT_READ, read_packet, client_p, 0);
 384                         return;
 385                 }
 386                 error_exit_client(client_p, length);
 387                 return;
 388         }
 389
 390 #ifdef USE_IODEBUG_HOOKS
 391         hdata.client = client_p;
 392         hdata.arg1 = readBuf;
 393         hdata.arg2 = length;
 394         call_hook(h_iorecv_id, &hdata);
 395 #endif
 396
 397         if(client_p->localClient->lasttime < rb_current_time())
 398                 client_p->localClient->lasttime = rb_current_time();
 399         client_p->flags &= ~FLAGS_PINGSENT;
 400
 401         /*
 402          * Before we even think of parsing what we just read, stick
 403          * it on the end of the receive queue and do it when its
 404          * turn comes around.
 405          */
 406         if(IsHandshake(client_p) || IsUnknown(client_p))
 407                 binary = 1;
 408
 409         lbuf_len = rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 410
 411         lclient_p->actually_read += lbuf_len;
 412
 413         if(IsAnyDead(client_p))
 414                 return;
 415
 416         /* Attempt to parse what we have */
 417         parse_client_queued(client_p);
 418
 419         if(IsAnyDead(client_p))
 420                 return;
 421
 422         /* Check to make sure we're not flooding */
 423         if(!IsAnyServer(client_p) &&
 424            (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood))
 425         {
 426                 if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 427                 {
 428                         exit_client(client_p, client_p, client_p, "Excess Flood");
 429                         return;
 430                 }
 431         }
 432
 433         /* If we get here, we need to register for another COMM_SELECT_READ */
 434         if(PARSE_AS_SERVER(client_p))
 435         {
 436                 rb_setselect(client_p->localClient->F->fd, FDLIST_SERVER, COMM_SELECT_READ,
 437                               read_packet, client_p, 0);
 438         }
 439         else
 440         {
 441                 rb_setselect(client_p->localClient->F->fd, FDLIST_IDLECLIENT,
 442                                COMM_SELECT_READ, read_packet, client_p, 0);
 443         }
 444 }
 445
 446 /*
 447  * client_dopacket - copy packet to client buf and parse it
 448  *      client_p - pointer to client structure for which the buffer data
 449  *             applies.
 450  *      buffer - pointr to the buffer containing the newly read data
 451  *      length - number of valid bytes of data in the buffer
 452  *
 453  * Note:
 454  *      It is implicitly assumed that dopacket is called only
 455  *      with client_p of "local" variation, which contains all the
 456  *      necessary fields (buffer etc..)
 457  */
 458 void
 459 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 460 {
 461         s_assert(client_p != NULL);
 462         s_assert(buffer != NULL);
 463
 464         if(client_p == NULL || buffer == NULL)
 465                 return;
 466         if(IsAnyDead(client_p))
 467                 return;
 468         /*
 469          * Update messages received
 470          */
 471         ++me.localClient->receiveM;
 472         ++client_p->localClient->receiveM;
 473
 474         /*
 475          * Update bytes received
 476          */
 477         client_p->localClient->receiveB += length;
 478
 479         if(client_p->localClient->receiveB > 1023)
 480         {
 481                 client_p->localClient->receiveK += (client_p->localClient->receiveB >> 10);
 482                 client_p->localClient->receiveB &= 0x03ff;      /* 2^10 = 1024, 3ff = 1023 */
 483         }
 484
 485         me.localClient->receiveB += length;
 486
 487         if(me.localClient->receiveB > 1023)
 488         {
 489                 me.localClient->receiveK += (me.localClient->receiveB >> 10);
 490                 me.localClient->receiveB &= 0x03ff;
 491         }
 492
 493         parse(client_p, buffer, buffer + length);
 494 }