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 #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                 /* allow opers 4 times the amount of messages as users. why 4?
 112                  * why not. :) --fl_
 113                  */
 114                 if(IsOper(client_p) && ConfigFileEntry.no_oper_flood)
 115                         allow_read *= 4;
 116                 /*
 117                  * Handle flood protection here - if we exceed our flood limit on
 118                  * messages in this loop, we simply drop out of the loop prematurely.
 119                  *   -- adrian
 120                  */
 121                 for (;;)
 122                 {
 123                         /* This flood protection works as follows:
 124                          *
 125                          * A client is given allow_read lines to send to the server.  Every
 126                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 127                          * is decreased by 1 every time flood_recalc is called.
 128                          *
 129                          * Thus a client can 'burst' allow_read lines to the server, any
 130                          * excess lines will be parsed one per flood_recalc() call.
 131                          *
 132                          * Therefore a client will be penalised more if they keep flooding,
 133                          * as sent_parsed will always hover around the allow_read limit
 134                          * and no 'bursts' will be permitted.
 135                          */
 136                         if(client_p->localClient->sent_parsed >= allow_read)
 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
 150                         client_p->localClient->sent_parsed += ConfigFileEntry.client_flood_message_time;
 151                 }
 152                 /* If sent_parsed is impossibly high, drop it down.
 153                  * This is useful if the configuration is changed.
 154                  */
 155                 if(client_p->localClient->sent_parsed > allow_read +
 156                                 ConfigFileEntry.client_flood_message_time - 1)
 157                         client_p->localClient->sent_parsed = allow_read +
 158                                 ConfigFileEntry.client_flood_message_time - 1;
 159         }
 160 }
 161
 162 /* flood_endgrace()
 163  *
 164  * marks the end of the clients grace period
 165  */
 166 void
 167 flood_endgrace(struct Client *client_p)
 168 {
 169         SetFloodDone(client_p);
 170
 171         /* sent_parsed could be way over client_flood_burst_max but under
 172          * client_flood_burst_rate so reset it.
 173          */
 174         client_p->localClient->sent_parsed = 0;
 175 }
 176
 177 /*
 178  * flood_recalc
 179  *
 180  * recalculate the number of allowed flood lines. this should be called
 181  * once a second on any given client. We then attempt to flush some data.
 182  */
 183 void
 184 flood_recalc(void *unused)
 185 {
 186         rb_dlink_node *ptr, *next;
 187         struct Client *client_p;
 188
 189         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 190         {
 191                 client_p = ptr->data;
 192
 193                 if(rb_unlikely(IsMe(client_p)))
 194                         continue;
 195
 196                 if(rb_unlikely(client_p->localClient == NULL))
 197                         continue;
 198
 199                 if(IsFloodDone(client_p))
 200                         client_p->localClient->sent_parsed -= ConfigFileEntry.client_flood_message_num;
 201                 else
 202                         client_p->localClient->sent_parsed = 0;
 203
 204                 if(client_p->localClient->sent_parsed < 0)
 205                         client_p->localClient->sent_parsed = 0;
 206
 207                 parse_client_queued(client_p);
 208
 209                 if(rb_unlikely(IsAnyDead(client_p)))
 210                         continue;
 211
 212         }
 213
 214         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 215         {
 216                 client_p = ptr->data;
 217
 218                 if(client_p->localClient == NULL)
 219                         continue;
 220
 221                 client_p->localClient->sent_parsed--;
 222
 223                 if(client_p->localClient->sent_parsed < 0)
 224                         client_p->localClient->sent_parsed = 0;
 225
 226                 parse_client_queued(client_p);
 227         }
 228 }
 229
 230 /*
 231  * read_packet - Read a 'packet' of data from a connection and process it.
 232  */
 233 void
 234 read_packet(rb_fde_t * F, void *data)
 235 {
 236         struct Client *client_p = data;
 237         int length = 0;
 238         int lbuf_len;
 239
 240         int binary = 0;
 241 #ifdef USE_IODEBUG_HOOKS
 242         hook_data_int hdata;
 243 #endif
 244
 245         while(1)
 246         {
 247                 if(IsAnyDead(client_p))
 248                         return;
 249
 250                 /*
 251                  * Read some data. We *used to* do anti-flood protection here, but
 252                  * I personally think it makes the code too hairy to make sane.
 253                  *     -- adrian
 254                  */
 255                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 256
 257                 if(length < 0)
 258                 {
 259                         if(rb_ignore_errno(errno))
 260                                 rb_setselect(client_p->localClient->F,
 261                                                 RB_SELECT_READ, read_packet, client_p);
 262                         else
 263                                 error_exit_client(client_p, length);
 264                         return;
 265                 }
 266                 else if(length == 0)
 267                 {
 268                         error_exit_client(client_p, length);
 269                         return;
 270                 }
 271
 272 #ifdef USE_IODEBUG_HOOKS
 273                 hdata.client = client_p;
 274                 hdata.arg1 = readBuf;
 275                 hdata.arg2 = length;
 276                 call_hook(h_iorecv_id, &hdata);
 277 #endif
 278
 279                 if(client_p->localClient->lasttime < rb_current_time())
 280                         client_p->localClient->lasttime = rb_current_time();
 281                 client_p->flags &= ~FLAGS_PINGSENT;
 282
 283                 /*
 284                  * Before we even think of parsing what we just read, stick
 285                  * it on the end of the receive queue and do it when its
 286                  * turn comes around.
 287                  */
 288                 if(IsHandshake(client_p) || IsUnknown(client_p))
 289                         binary = 1;
 290
 291                 lbuf_len = rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 292
 293                 if(IsAnyDead(client_p))
 294                         return;
 295
 296                 /* Attempt to parse what we have */
 297                 parse_client_queued(client_p);
 298
 299                 if(IsAnyDead(client_p))
 300                         return;
 301
 302                 /* Check to make sure we're not flooding */
 303                 if(!IsAnyServer(client_p) &&
 304                    (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood_max_lines))
 305                 {
 306                         if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 307                         {
 308                                 exit_client(client_p, client_p, client_p, "Excess Flood");
 309                                 return;
 310                         }
 311                 }
 312
 313                 /* bail if short read */
 314                 if(length < READBUF_SIZE)
 315                 {
 316                         rb_setselect(client_p->localClient->F, RB_SELECT_READ, read_packet, client_p);
 317                         return;
 318                 }
 319         }
 320 }
 321
 322 /*
 323  * client_dopacket - copy packet to client buf and parse it
 324  *      client_p - pointer to client structure for which the buffer data
 325  *             applies.
 326  *      buffer - pointr to the buffer containing the newly read data
 327  *      length - number of valid bytes of data in the buffer
 328  *
 329  * Note:
 330  *      It is implicitly assumed that dopacket is called only
 331  *      with client_p of "local" variation, which contains all the
 332  *      necessary fields (buffer etc..)
 333  */
 334 void
 335 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 336 {
 337         s_assert(client_p != NULL);
 338         s_assert(buffer != NULL);
 339
 340         if(client_p == NULL || buffer == NULL)
 341                 return;
 342         if(IsAnyDead(client_p))
 343                 return;
 344         /*
 345          * Update messages received
 346          */
 347         ++me.localClient->receiveM;
 348         ++client_p->localClient->receiveM;
 349
 350         /*
 351          * Update bytes received
 352          */
 353         client_p->localClient->receiveB += length;
 354
 355         if(client_p->localClient->receiveB > 1023)
 356         {
 357                 client_p->localClient->receiveK += (client_p->localClient->receiveB >> 10);
 358                 client_p->localClient->receiveB &= 0x03ff;      /* 2^10 = 1024, 3ff = 1023 */
 359         }
 360
 361         me.localClient->receiveB += length;
 362
 363         if(me.localClient->receiveB > 1023)
 364         {
 365                 me.localClient->receiveK += (me.localClient->receiveB >> 10);
 366                 me.localClient->receiveB &= 0x03ff;
 367         }
 368
 369         parse(client_p, buffer, buffer + length);
 370 }