ircd/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 "match.h"
  35 #include "hook.h"
  36 #include "send.h"
  37 #include "s_assert.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  * 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 allow_read;
  50
  51         if(IsAnyDead(client_p))
  52                 return;
  53
  54         if(IsUnknown(client_p))
  55         {
  56                 allow_read = ConfigFileEntry.client_flood_burst_max;
  57                 for (;;)
  58                 {
  59                         if(client_p->localClient->sent_parsed >= allow_read)
  60                                 break;
  61
  62                         dolen = rb_linebuf_get(&client_p->localClient->
  63                                             buf_recvq, readBuf, READBUF_SIZE,
  64                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
  65
  66                         if(dolen <= 0 || IsDead(client_p))
  67                                 break;
  68
  69                         client_dopacket(client_p, readBuf, dolen);
  70                         client_p->localClient->sent_parsed++;
  71
  72                         /* He's dead cap'n */
  73                         if(IsAnyDead(client_p))
  74                                 return;
  75                         /* if theyve dropped out of the unknown state, break and move
  76                          * to the parsing for their appropriate status.  --fl
  77                          */
  78                         if(!IsUnknown(client_p))
  79                         {
  80                                 /* reset their flood limits, they're now
  81                                  * graced to flood
  82                                  */
  83                                 client_p->localClient->sent_parsed = 0;
  84                                 break;
  85                         }
  86
  87                 }
  88                 /* If sent_parsed is impossibly high, drop it down.
  89                  * This is useful if the configuration is changed.
  90                  */
  91                 if(client_p->localClient->sent_parsed > allow_read)
  92                         client_p->localClient->sent_parsed = allow_read;
  93         }
  94
  95         if(IsAnyServer(client_p) || IsExemptFlood(client_p))
  96         {
  97                 while (!IsAnyDead(client_p) && (dolen = rb_linebuf_get(&client_p->localClient->buf_recvq,
  98                                            readBuf, READBUF_SIZE, LINEBUF_COMPLETE,
  99                                            LINEBUF_PARSED)) > 0)
 100                 {
 101                         client_dopacket(client_p, readBuf, dolen);
 102                 }
 103         }
 104         else if(IsClient(client_p))
 105         {
 106                 if(IsFloodDone(client_p))
 107                         allow_read = ConfigFileEntry.client_flood_burst_max;
 108                 else
 109                         allow_read = ConfigFileEntry.client_flood_burst_rate;
 110                 allow_read *= ConfigFileEntry.client_flood_message_time;
 111
 112                 /* allow opers 4 times the amount of messages as users. why 4?
 113                  * why not. :) --fl_
 114                  */
 115                 if(IsOper(client_p) && ConfigFileEntry.no_oper_flood)
 116                         allow_read *= 4;
 117                 else
 118                 {
 119                         /*
 120                          * If a client's sendq is greater than the soft limit, do not allow any
 121                          * more messages to be read.  This allows us to safely handle commands like
 122                          * LIST without harming the server.  --kaniini
 123                          */
 124                         if (rb_linebuf_len(&client_p->localClient->buf_sendq) > (get_sendq(client_p)))
 125                                 allow_read = 0;
 126                 }
 127
 128                 /*
 129                  * Handle flood protection here - if we exceed our flood limit on
 130                  * messages in this loop, we simply drop out of the loop prematurely.
 131                  *   -- adrian
 132                  */
 133                 for (;;)
 134                 {
 135                         /* This flood protection works as follows:
 136                          *
 137                          * A client is given allow_read lines to send to the server.  Every
 138                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 139                          * is decreased by 1 every time flood_recalc is called.
 140                          *
 141                          * Thus a client can 'burst' allow_read lines to the server, any
 142                          * excess lines will be parsed one per flood_recalc() call.
 143                          *
 144                          * Therefore a client will be penalised more if they keep flooding,
 145                          * as sent_parsed will always hover around the allow_read limit
 146                          * and no 'bursts' will be permitted.
 147                          */
 148                         if(client_p->localClient->sent_parsed >= allow_read)
 149                                 break;
 150
 151                         dolen = rb_linebuf_get(&client_p->localClient->
 152                                             buf_recvq, readBuf, READBUF_SIZE,
 153                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 154
 155                         if(!dolen)
 156                                 break;
 157
 158                         client_dopacket(client_p, readBuf, dolen);
 159                         if(IsAnyDead(client_p))
 160                                 return;
 161
 162                         client_p->localClient->sent_parsed += ConfigFileEntry.client_flood_message_time;
 163                 }
 164                 /* If sent_parsed is impossibly high, drop it down.
 165                  * This is useful if the configuration is changed.
 166                  */
 167                 if(client_p->localClient->sent_parsed > allow_read +
 168                                 ConfigFileEntry.client_flood_message_time - 1)
 169                         client_p->localClient->sent_parsed = allow_read +
 170                                 ConfigFileEntry.client_flood_message_time - 1;
 171         }
 172 }
 173
 174 /* flood_endgrace()
 175  *
 176  * marks the end of the clients grace period
 177  */
 178 void
 179 flood_endgrace(struct Client *client_p)
 180 {
 181         SetFloodDone(client_p);
 182
 183         /* sent_parsed could be way over client_flood_burst_max but under
 184          * client_flood_burst_rate so reset it.
 185          */
 186         client_p->localClient->sent_parsed = 0;
 187 }
 188
 189 /*
 190  * flood_recalc
 191  *
 192  * recalculate the number of allowed flood lines. this should be called
 193  * once a second on any given client. We then attempt to flush some data.
 194  */
 195 void
 196 flood_recalc(void *unused)
 197 {
 198         rb_dlink_node *ptr, *next;
 199         struct Client *client_p;
 200
 201         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 202         {
 203                 client_p = ptr->data;
 204
 205                 if(rb_unlikely(IsMe(client_p)))
 206                         continue;
 207
 208                 if(rb_unlikely(client_p->localClient == NULL))
 209                         continue;
 210
 211                 if(IsFloodDone(client_p))
 212                         client_p->localClient->sent_parsed -= ConfigFileEntry.client_flood_message_num;
 213                 else
 214                         client_p->localClient->sent_parsed = 0;
 215
 216                 if(client_p->localClient->sent_parsed < 0)
 217                         client_p->localClient->sent_parsed = 0;
 218
 219                 parse_client_queued(client_p);
 220
 221                 if(rb_unlikely(IsAnyDead(client_p)))
 222                         continue;
 223
 224         }
 225
 226         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 227         {
 228                 client_p = ptr->data;
 229
 230                 if(client_p->localClient == NULL)
 231                         continue;
 232
 233                 client_p->localClient->sent_parsed--;
 234
 235                 if(client_p->localClient->sent_parsed < 0)
 236                         client_p->localClient->sent_parsed = 0;
 237
 238                 parse_client_queued(client_p);
 239         }
 240 }
 241
 242 /*
 243  * read_packet - Read a 'packet' of data from a connection and process it.
 244  */
 245 void
 246 read_packet(rb_fde_t * F, void *data)
 247 {
 248         struct Client *client_p = data;
 249         int length = 0;
 250
 251         int binary = 0;
 252 #ifdef USE_IODEBUG_HOOKS
 253         hook_data_int hdata;
 254 #endif
 255
 256         while(1)
 257         {
 258                 if(IsAnyDead(client_p))
 259                         return;
 260
 261                 /*
 262                  * Read some data. We *used to* do anti-flood protection here, but
 263                  * I personally think it makes the code too hairy to make sane.
 264                  *     -- adrian
 265                  */
 266                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 267
 268                 if(length < 0)
 269                 {
 270                         if(rb_ignore_errno(errno))
 271                                 rb_setselect(client_p->localClient->F,
 272                                                 RB_SELECT_READ, read_packet, client_p);
 273                         else
 274                                 error_exit_client(client_p, length);
 275                         return;
 276                 }
 277                 else if(length == 0)
 278                 {
 279                         error_exit_client(client_p, length);
 280                         return;
 281                 }
 282
 283 #ifdef USE_IODEBUG_HOOKS
 284                 hdata.client = client_p;
 285                 hdata.arg1 = readBuf;
 286                 hdata.arg2 = length;
 287                 call_hook(h_iorecv_id, &hdata);
 288 #endif
 289
 290                 if(client_p->localClient->lasttime < rb_current_time())
 291                         client_p->localClient->lasttime = rb_current_time();
 292                 client_p->flags &= ~FLAGS_PINGSENT;
 293
 294                 /*
 295                  * Before we even think of parsing what we just read, stick
 296                  * it on the end of the receive queue and do it when its
 297                  * turn comes around.
 298                  */
 299                 if(IsHandshake(client_p) || IsUnknown(client_p))
 300                         binary = 1;
 301
 302                 (void) rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 303
 304                 if(IsAnyDead(client_p))
 305                         return;
 306
 307                 /* Attempt to parse what we have */
 308                 parse_client_queued(client_p);
 309
 310                 if(IsAnyDead(client_p))
 311                         return;
 312
 313                 /* Check to make sure we're not flooding */
 314                 if(!IsAnyServer(client_p) &&
 315                    (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood_max_lines))
 316                 {
 317                         if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 318                         {
 319                                 exit_client(client_p, client_p, client_p, "Excess Flood");
 320                                 return;
 321                         }
 322                 }
 323
 324                 /* bail if short read */
 325                 if(length < READBUF_SIZE)
 326                 {
 327                         rb_setselect(client_p->localClient->F, RB_SELECT_READ, read_packet, client_p);
 328                         return;
 329                 }
 330         }
 331 }
 332
 333 /*
 334  * client_dopacket - copy packet to client buf and parse it
 335  *      client_p - pointer to client structure for which the buffer data
 336  *             applies.
 337  *      buffer - pointr to the buffer containing the newly read data
 338  *      length - number of valid bytes of data in the buffer
 339  *
 340  * Note:
 341  *      It is implicitly assumed that dopacket is called only
 342  *      with client_p of "local" variation, which contains all the
 343  *      necessary fields (buffer etc..)
 344  */
 345 void
 346 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 347 {
 348         s_assert(client_p != NULL);
 349         s_assert(buffer != NULL);
 350
 351         if(client_p == NULL || buffer == NULL)
 352                 return;
 353         if(IsAnyDead(client_p))
 354                 return;
 355         /*
 356          * Update messages received
 357          */
 358         ++me.localClient->receiveM;
 359         ++client_p->localClient->receiveM;
 360
 361         /*
 362          * Update bytes received
 363          */
 364         client_p->localClient->receiveB += length;
 365
 366         if(client_p->localClient->receiveB > 1023)
 367         {
 368                 client_p->localClient->receiveK += (client_p->localClient->receiveB >> 10);
 369                 client_p->localClient->receiveB &= 0x03ff;      /* 2^10 = 1024, 3ff = 1023 */
 370         }
 371
 372         me.localClient->receiveB += length;
 373
 374         if(me.localClient->receiveB > 1023)
 375         {
 376                 me.localClient->receiveK += (me.localClient->receiveB >> 10);
 377                 me.localClient->receiveB &= 0x03ff;
 378         }
 379
 380         parse(client_p, buffer, buffer + length);
 381 }