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  */
  25 #include "stdinc.h"
  26 #include "s_conf.h"
  27 #include "s_serv.h"
  28 #include "client.h"
  29 #include "common.h"
  30 #include "ircd.h"
  31 #include "parse.h"
  32 #include "packet.h"
  33 #include "match.h"
  34 #include "hook.h"
  35 #include "send.h"
  36
  37 static char readBuf[READBUF_SIZE];
  38 static void client_dopacket(struct Client *client_p, char *buffer, size_t length);
  39
  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 checkflood = 1;
  49
  50         if(IsAnyDead(client_p))
  51                 return;
  52
  53         if(IsUnknown(client_p))
  54         {
  55                 for (;;)
  56                 {
  57                         if(client_p->localClient->sent_parsed >= client_p->localClient->allow_read)
  58                                 break;
  59
  60                         dolen = rb_linebuf_get(&client_p->localClient->
  61                                             buf_recvq, readBuf, READBUF_SIZE,
  62                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
  63
  64                         if(dolen <= 0 || IsDead(client_p))
  65                                 break;
  66
  67                         client_dopacket(client_p, readBuf, dolen);
  68                         client_p->localClient->sent_parsed++;
  69
  70                         /* He's dead cap'n */
  71                         if(IsAnyDead(client_p))
  72                                 return;
  73                         /* if theyve dropped out of the unknown state, break and move
  74                          * to the parsing for their appropriate status.  --fl
  75                          */
  76                         if(!IsUnknown(client_p))
  77                         {
  78                                 /* reset their flood limits, they're now
  79                                  * graced to flood
  80                                  */
  81                                 client_p->localClient->sent_parsed = 0;
  82                                 break;
  83                         }
  84
  85                 }
  86         }
  87
  88         if(IsAnyServer(client_p) || IsExemptFlood(client_p))
  89         {
  90                 while (!IsAnyDead(client_p) && (dolen = rb_linebuf_get(&client_p->localClient->buf_recvq,
  91                                            readBuf, READBUF_SIZE, LINEBUF_COMPLETE,
  92                                            LINEBUF_PARSED)) > 0)
  93                 {
  94                         client_dopacket(client_p, readBuf, dolen);
  95                 }
  96         }
  97         else if(IsClient(client_p))
  98         {
  99
 100                 if(IsOper(client_p) && ConfigFileEntry.no_oper_flood)
 101                 {
 102                         if (ConfigFileEntry.true_no_oper_flood)
 103                                 checkflood = -1;
 104                         else
 105                                 checkflood = 0;
 106                 }
 107                 /*
 108                  * Handle flood protection here - if we exceed our flood limit on
 109                  * messages in this loop, we simply drop out of the loop prematurely.
 110                  *   -- adrian
 111                  */
 112                 for (;;)
 113                 {
 114                         /* This flood protection works as follows:
 115                          *
 116                          * A client is given allow_read lines to send to the server.  Every
 117                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 118                          * is decreased by 1 every time flood_recalc is called.
 119                          *
 120                          * Thus a client can 'burst' allow_read lines to the server, any
 121                          * excess lines will be parsed one per flood_recalc() call.
 122                          *
 123                          * Therefore a client will be penalised more if they keep flooding,
 124                          * as sent_parsed will always hover around the allow_read limit
 125                          * and no 'bursts' will be permitted.
 126                          */
 127                         if(checkflood)
 128                         {
 129                                 if(client_p->localClient->sent_parsed >= client_p->localClient->allow_read)
 130                                         break;
 131                         }
 132
 133                         /* allow opers 4 times the amount of messages as users. why 4?
 134                          * why not. :) --fl_
 135                          */
 136                         else if(client_p->localClient->sent_parsed >= (4 * client_p->localClient->allow_read) && checkflood != -1)
 137                                 break;
 138
 139                         dolen = rb_linebuf_get(&client_p->localClient->
 140                                             buf_recvq, readBuf, READBUF_SIZE,
 141                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 142
 143                         if(!dolen)
 144                                 break;
 145
 146                         client_dopacket(client_p, readBuf, dolen);
 147                         if(IsAnyDead(client_p))
 148                                 return;
 149                         client_p->localClient->sent_parsed++;
 150                 }
 151         }
 152 }
 153
 154 /* flood_endgrace()
 155  *
 156  * marks the end of the clients grace period
 157  */
 158 void
 159 flood_endgrace(struct Client *client_p)
 160 {
 161         SetFloodDone(client_p);
 162
 163         /* Drop their flood limit back down */
 164         client_p->localClient->allow_read = MAX_FLOOD;
 165
 166         /* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
 167          * so reset it.
 168          */
 169         client_p->localClient->sent_parsed = 0;
 170 }
 171
 172 /*
 173  * flood_recalc
 174  *
 175  * recalculate the number of allowed flood lines. this should be called
 176  * once a second on any given client. We then attempt to flush some data.
 177  */
 178 void
 179 flood_recalc(void *unused)
 180 {
 181         rb_dlink_node *ptr, *next;
 182         struct Client *client_p;
 183
 184         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 185         {
 186                 client_p = ptr->data;
 187
 188                 if(rb_unlikely(IsMe(client_p)))
 189                         continue;
 190
 191                 if(rb_unlikely(client_p->localClient == NULL))
 192                         continue;
 193
 194                 if(IsFloodDone(client_p))
 195                         client_p->localClient->sent_parsed -= 2;
 196                 else
 197                         client_p->localClient->sent_parsed = 0;
 198
 199                 if(client_p->localClient->sent_parsed < 0)
 200                         client_p->localClient->sent_parsed = 0;
 201
 202                 if(--client_p->localClient->actually_read < 0)
 203                         client_p->localClient->actually_read = 0;
 204
 205                 parse_client_queued(client_p);
 206
 207                 if(rb_unlikely(IsAnyDead(client_p)))
 208                         continue;
 209
 210         }
 211
 212         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 213         {
 214                 client_p = ptr->data;
 215
 216                 if(client_p->localClient == NULL)
 217                         continue;
 218
 219                 client_p->localClient->sent_parsed--;
 220
 221                 if(client_p->localClient->sent_parsed < 0)
 222                         client_p->localClient->sent_parsed = 0;
 223
 224                 if(--client_p->localClient->actually_read < 0)
 225                         client_p->localClient->actually_read = 0;
 226
 227                 parse_client_queued(client_p);
 228         }
 229 }
 230
 231 /*
 232  * read_packet - Read a 'packet' of data from a connection and process it.
 233  */
 234 void
 235 read_packet(rb_fde_t * F, void *data)
 236 {
 237         struct Client *client_p = data;
 238         struct LocalUser *lclient_p = client_p->localClient;
 239         int length = 0;
 240         int lbuf_len;
 241
 242         int binary = 0;
 243 #ifdef USE_IODEBUG_HOOKS
 244         hook_data_int hdata;
 245 #endif
 246
 247         while(1)
 248         {
 249                 if(IsAnyDead(client_p))
 250                         return;
 251
 252                 /*
 253                  * Read some data. We *used to* do anti-flood protection here, but
 254                  * I personally think it makes the code too hairy to make sane.
 255                  *     -- adrian
 256                  */
 257                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 258
 259                 if(length < 0)
 260                 {
 261                         if(rb_ignore_errno(errno))
 262                                 rb_setselect(client_p->localClient->F,
 263                                                 RB_SELECT_READ, read_packet, client_p);
 264                         else
 265                                 error_exit_client(client_p, length);
 266                         return;
 267                 }
 268                 else if(length == 0)
 269                 {
 270                         error_exit_client(client_p, length);
 271                         return;
 272                 }
 273
 274 #ifdef USE_IODEBUG_HOOKS
 275                 hdata.client = client_p;
 276                 hdata.arg1 = readBuf;
 277                 hdata.arg2 = length;
 278                 call_hook(h_iorecv_id, &hdata);
 279 #endif
 280
 281                 if(client_p->localClient->lasttime < rb_current_time())
 282                         client_p->localClient->lasttime = rb_current_time();
 283                 client_p->flags &= ~FLAGS_PINGSENT;
 284
 285                 /*
 286                  * Before we even think of parsing what we just read, stick
 287                  * it on the end of the receive queue and do it when its
 288                  * turn comes around.
 289                  */
 290                 if(IsHandshake(client_p) || IsUnknown(client_p))
 291                         binary = 1;
 292
 293                 lbuf_len = rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 294
 295                 lclient_p->actually_read += lbuf_len;
 296
 297                 if(IsAnyDead(client_p))
 298                         return;
 299
 300                 /* Attempt to parse what we have */
 301                 parse_client_queued(client_p);
 302
 303                 if(IsAnyDead(client_p))
 304                         return;
 305
 306                 /* Check to make sure we're not flooding */
 307                 if(!IsAnyServer(client_p) &&
 308                    (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood))
 309                 {
 310                         if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 311                         {
 312                                 exit_client(client_p, client_p, client_p, "Excess Flood");
 313                                 return;
 314                         }
 315                 }
 316
 317                 /* bail if short read */
 318                 if(length < READBUF_SIZE)
 319                 {
 320                         rb_setselect(client_p->localClient->F, RB_SELECT_READ, read_packet, client_p);
 321                         return;
 322                 }
 323         }
 324 }
 325
 326 /*
 327  * client_dopacket - copy packet to client buf and parse it
 328  *      client_p - pointer to client structure for which the buffer data
 329  *             applies.
 330  *      buffer - pointr to the buffer containing the newly read data
 331  *      length - number of valid bytes of data in the buffer
 332  *
 333  * Note:
 334  *      It is implicitly assumed that dopacket is called only
 335  *      with client_p of "local" variation, which contains all the
 336  *      necessary fields (buffer etc..)
 337  */
 338 void
 339 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 340 {
 341         s_assert(client_p != NULL);
 342         s_assert(buffer != NULL);
 343
 344         if(client_p == NULL || buffer == NULL)
 345                 return;
 346         if(IsAnyDead(client_p))
 347                 return;
 348         /*
 349          * Update messages received
 350          */
 351         ++me.localClient->receiveM;
 352         ++client_p->localClient->receiveM;
 353
 354         /*
 355          * Update bytes received
 356          */
 357         client_p->localClient->receiveB += length;
 358
 359         if(client_p->localClient->receiveB > 1023)
 360         {
 361                 client_p->localClient->receiveK += (client_p->localClient->receiveB >> 10);
 362                 client_p->localClient->receiveB &= 0x03ff;      /* 2^10 = 1024, 3ff = 1023 */
 363         }
 364
 365         me.localClient->receiveB += length;
 366
 367         if(me.localClient->receiveB > 1023)
 368         {
 369                 me.localClient->receiveK += (me.localClient->receiveB >> 10);
 370                 me.localClient->receiveB &= 0x03ff;
 371         }
 372
 373         parse(client_p, buffer, buffer + length);
 374 }