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 "match.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  * parse_client_queued - parse client queued messages
  43  */
  44 static void
  45 parse_client_queued(struct Client *client_p)
  46 {
  47         int dolen = 0;
  48         int allow_read;
  49
  50         if(IsAnyDead(client_p))
  51                 return;
  52
  53         if(IsUnknown(client_p))
  54         {
  55                 allow_read = ConfigFileEntry.client_flood_burst_max;
  56                 for (;;)
  57                 {
  58                         if(client_p->localClient->sent_parsed >= 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                 /* If sent_parsed is impossibly high, drop it down.
  88                  * This is useful if the configuration is changed.
  89                  */
  90                 if(client_p->localClient->sent_parsed > allow_read)
  91                         client_p->localClient->sent_parsed = allow_read;
  92         }
  93
  94         if(IsAnyServer(client_p) || IsExemptFlood(client_p))
  95         {
  96                 while (!IsAnyDead(client_p) && (dolen = rb_linebuf_get(&client_p->localClient->buf_recvq,
  97                                            readBuf, READBUF_SIZE, LINEBUF_COMPLETE,
  98                                            LINEBUF_PARSED)) > 0)
  99                 {
 100                         client_dopacket(client_p, readBuf, dolen);
 101                 }
 102         }
 103         else if(IsClient(client_p))
 104         {
 105                 if(IsFloodDone(client_p))
 106                         allow_read = ConfigFileEntry.client_flood_burst_max;
 107                 else
 108                         allow_read = ConfigFileEntry.client_flood_burst_rate;
 109                 allow_read *= ConfigFileEntry.client_flood_message_time;
 110                 /* allow opers 4 times the amount of messages as users. why 4?
 111                  * why not. :) --fl_
 112                  */
 113                 if(IsOper(client_p) && ConfigFileEntry.no_oper_flood)
 114                         allow_read *= 4;
 115                 /*
 116                  * Handle flood protection here - if we exceed our flood limit on
 117                  * messages in this loop, we simply drop out of the loop prematurely.
 118                  *   -- adrian
 119                  */
 120                 for (;;)
 121                 {
 122                         /* This flood protection works as follows:
 123                          *
 124                          * A client is given allow_read lines to send to the server.  Every
 125                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 126                          * is decreased by 1 every time flood_recalc is called.
 127                          *
 128                          * Thus a client can 'burst' allow_read lines to the server, any
 129                          * excess lines will be parsed one per flood_recalc() call.
 130                          *
 131                          * Therefore a client will be penalised more if they keep flooding,
 132                          * as sent_parsed will always hover around the allow_read limit
 133                          * and no 'bursts' will be permitted.
 134                          */
 135                         if(client_p->localClient->sent_parsed >= allow_read)
 136                                 break;
 137
 138                         dolen = rb_linebuf_get(&client_p->localClient->
 139                                             buf_recvq, readBuf, READBUF_SIZE,
 140                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 141
 142                         if(!dolen)
 143                                 break;
 144
 145                         client_dopacket(client_p, readBuf, dolen);
 146                         if(IsAnyDead(client_p))
 147                                 return;
 148
 149                         client_p->localClient->sent_parsed += ConfigFileEntry.client_flood_message_time;
 150                 }
 151                 /* If sent_parsed is impossibly high, drop it down.
 152                  * This is useful if the configuration is changed.
 153                  */
 154                 if(client_p->localClient->sent_parsed > allow_read +
 155                                 ConfigFileEntry.client_flood_message_time - 1)
 156                         client_p->localClient->sent_parsed = allow_read +
 157                                 ConfigFileEntry.client_flood_message_time - 1;
 158         }
 159 }
 160
 161 /* flood_endgrace()
 162  *
 163  * marks the end of the clients grace period
 164  */
 165 void
 166 flood_endgrace(struct Client *client_p)
 167 {
 168         SetFloodDone(client_p);
 169
 170         /* sent_parsed could be way over client_flood_burst_max but under
 171          * client_flood_burst_rate so reset it.
 172          */
 173         client_p->localClient->sent_parsed = 0;
 174 }
 175
 176 /*
 177  * flood_recalc
 178  *
 179  * recalculate the number of allowed flood lines. this should be called
 180  * once a second on any given client. We then attempt to flush some data.
 181  */
 182 void
 183 flood_recalc(void *unused)
 184 {
 185         rb_dlink_node *ptr, *next;
 186         struct Client *client_p;
 187
 188         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 189         {
 190                 client_p = ptr->data;
 191
 192                 if(rb_unlikely(IsMe(client_p)))
 193                         continue;
 194
 195                 if(rb_unlikely(client_p->localClient == NULL))
 196                         continue;
 197
 198                 if(IsFloodDone(client_p))
 199                         client_p->localClient->sent_parsed -= ConfigFileEntry.client_flood_message_num;
 200                 else
 201                         client_p->localClient->sent_parsed = 0;
 202
 203                 if(client_p->localClient->sent_parsed < 0)
 204                         client_p->localClient->sent_parsed = 0;
 205
 206                 parse_client_queued(client_p);
 207
 208                 if(rb_unlikely(IsAnyDead(client_p)))
 209                         continue;
 210
 211         }
 212
 213         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 214         {
 215                 client_p = ptr->data;
 216
 217                 if(client_p->localClient == NULL)
 218                         continue;
 219
 220                 client_p->localClient->sent_parsed--;
 221
 222                 if(client_p->localClient->sent_parsed < 0)
 223                         client_p->localClient->sent_parsed = 0;
 224
 225                 parse_client_queued(client_p);
 226         }
 227 }
 228
 229 /*
 230  * read_packet - Read a 'packet' of data from a connection and process it.
 231  */
 232 void
 233 read_packet(rb_fde_t * F, void *data)
 234 {
 235         struct Client *client_p = data;
 236         int length = 0;
 237         int lbuf_len;
 238
 239         int binary = 0;
 240 #ifdef USE_IODEBUG_HOOKS
 241         hook_data_int hdata;
 242 #endif
 243
 244         while(1)
 245         {
 246                 if(IsAnyDead(client_p))
 247                         return;
 248
 249                 /*
 250                  * Read some data. We *used to* do anti-flood protection here, but
 251                  * I personally think it makes the code too hairy to make sane.
 252                  *     -- adrian
 253                  */
 254                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 255
 256                 if(length < 0)
 257                 {
 258                         if(rb_ignore_errno(errno))
 259                                 rb_setselect(client_p->localClient->F,
 260                                                 RB_SELECT_READ, read_packet, client_p);
 261                         else
 262                                 error_exit_client(client_p, length);
 263                         return;
 264                 }
 265                 else if(length == 0)
 266                 {
 267                         error_exit_client(client_p, length);
 268                         return;
 269                 }
 270
 271 #ifdef USE_IODEBUG_HOOKS
 272                 hdata.client = client_p;
 273                 hdata.arg1 = readBuf;
 274                 hdata.arg2 = length;
 275                 call_hook(h_iorecv_id, &hdata);
 276 #endif
 277
 278                 if(client_p->localClient->lasttime < rb_current_time())
 279                         client_p->localClient->lasttime = rb_current_time();
 280                 client_p->flags &= ~FLAGS_PINGSENT;
 281
 282                 /*
 283                  * Before we even think of parsing what we just read, stick
 284                  * it on the end of the receive queue and do it when its
 285                  * turn comes around.
 286                  */
 287                 if(IsHandshake(client_p) || IsUnknown(client_p))
 288                         binary = 1;
 289
 290                 lbuf_len = rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 291
 292                 if(IsAnyDead(client_p))
 293                         return;
 294
 295                 /* Attempt to parse what we have */
 296                 parse_client_queued(client_p);
 297
 298                 if(IsAnyDead(client_p))
 299                         return;
 300
 301                 /* Check to make sure we're not flooding */
 302                 if(!IsAnyServer(client_p) &&
 303                    (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood_max_lines))
 304                 {
 305                         if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 306                         {
 307                                 exit_client(client_p, client_p, client_p, "Excess Flood");
 308                                 return;
 309                         }
 310                 }
 311
 312                 /* bail if short read */
 313                 if(length < READBUF_SIZE)
 314                 {
 315                         rb_setselect(client_p->localClient->F, RB_SELECT_READ, read_packet, client_p);
 316                         return;
 317                 }
 318         }
 319 }
 320
 321 /*
 322  * client_dopacket - copy packet to client buf and parse it
 323  *      client_p - pointer to client structure for which the buffer data
 324  *             applies.
 325  *      buffer - pointr to the buffer containing the newly read data
 326  *      length - number of valid bytes of data in the buffer
 327  *
 328  * Note:
 329  *      It is implicitly assumed that dopacket is called only
 330  *      with client_p of "local" variation, which contains all the
 331  *      necessary fields (buffer etc..)
 332  */
 333 void
 334 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 335 {
 336         s_assert(client_p != NULL);
 337         s_assert(buffer != NULL);
 338
 339         if(client_p == NULL || buffer == NULL)
 340                 return;
 341         if(IsAnyDead(client_p))
 342                 return;
 343         /*
 344          * Update messages received
 345          */
 346         ++me.localClient->receiveM;
 347         ++client_p->localClient->receiveM;
 348
 349         /*
 350          * Update bytes received
 351          */
 352         client_p->localClient->receiveB += length;
 353
 354         if(client_p->localClient->receiveB > 1023)
 355         {
 356                 client_p->localClient->receiveK += (client_p->localClient->receiveB >> 10);
 357                 client_p->localClient->receiveB &= 0x03ff;      /* 2^10 = 1024, 3ff = 1023 */
 358         }
 359
 360         me.localClient->receiveB += length;
 361
 362         if(me.localClient->receiveB > 1023)
 363         {
 364                 me.localClient->receiveK += (me.localClient->receiveB >> 10);
 365                 me.localClient->receiveB &= 0x03ff;
 366         }
 367
 368         parse(client_p, buffer, buffer + length);
 369 }