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_packet - Read a 'packet' of data from a connection and process it.
 229  */
 230 void
 231 read_packet(int fd, void *data)
 232 {
 233         struct Client *client_p = data;
 234         struct LocalUser *lclient_p = client_p->localClient;
 235         int length = 0;
 236         int lbuf_len;
 237
 238         int binary = 0;
 239 #ifdef USE_IODEBUG_HOOKS
 240         hook_data_int hdata;
 241 #endif
 242         if(IsAnyDead(client_p))
 243                 return;
 244
 245         /*
 246          * Read some data. We *used to* do anti-flood protection here, but
 247          * I personally think it makes the code too hairy to make sane.
 248          *     -- adrian
 249          */
 250         length = client_p->localClient->F->read_impl(client_p->localClient->F, readBuf, READBUF_SIZE);
 251
 252         if(length <= 0)
 253         {
 254                 if((length == -1) && ignoreErrno(errno))
 255                 {
 256                         rb_setselect(client_p->localClient->F->fd, FDLIST_IDLECLIENT,
 257                                        COMM_SELECT_READ, read_packet, client_p, 0);
 258                         return;
 259                 }
 260                 error_exit_client(client_p, length);
 261                 return;
 262         }
 263
 264 #ifdef USE_IODEBUG_HOOKS
 265         hdata.client = client_p;
 266         hdata.arg1 = readBuf;
 267         hdata.arg2 = length;
 268         call_hook(h_iorecv_id, &hdata);
 269 #endif
 270
 271         if(client_p->localClient->lasttime < rb_current_time())
 272                 client_p->localClient->lasttime = rb_current_time();
 273         client_p->flags &= ~FLAGS_PINGSENT;
 274
 275         /*
 276          * Before we even think of parsing what we just read, stick
 277          * it on the end of the receive queue and do it when its
 278          * turn comes around.
 279          */
 280         if(IsHandshake(client_p) || IsUnknown(client_p))
 281                 binary = 1;
 282
 283         lbuf_len = rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 284
 285         lclient_p->actually_read += lbuf_len;
 286
 287         if(IsAnyDead(client_p))
 288                 return;
 289
 290         /* Attempt to parse what we have */
 291         parse_client_queued(client_p);
 292
 293         if(IsAnyDead(client_p))
 294                 return;
 295
 296         /* Check to make sure we're not flooding */
 297         if(!IsAnyServer(client_p) &&
 298            (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood))
 299         {
 300                 if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 301                 {
 302                         exit_client(client_p, client_p, client_p, "Excess Flood");
 303                         return;
 304                 }
 305         }
 306
 307         /* If we get here, we need to register for another COMM_SELECT_READ */
 308         if(PARSE_AS_SERVER(client_p))
 309         {
 310                 rb_setselect(client_p->localClient->F->fd, FDLIST_SERVER, COMM_SELECT_READ,
 311                               read_packet, client_p, 0);
 312         }
 313         else
 314         {
 315                 rb_setselect(client_p->localClient->F->fd, FDLIST_IDLECLIENT,
 316                                COMM_SELECT_READ, read_packet, client_p, 0);
 317         }
 318 }
 319
 320 /*
 321  * client_dopacket - copy packet to client buf and parse it
 322  *      client_p - pointer to client structure for which the buffer data
 323  *             applies.
 324  *      buffer - pointr to the buffer containing the newly read data
 325  *      length - number of valid bytes of data in the buffer
 326  *
 327  * Note:
 328  *      It is implicitly assumed that dopacket is called only
 329  *      with client_p of "local" variation, which contains all the
 330  *      necessary fields (buffer etc..)
 331  */
 332 void
 333 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 334 {
 335         s_assert(client_p != NULL);
 336         s_assert(buffer != NULL);
 337
 338         if(client_p == NULL || buffer == NULL)
 339                 return;
 340         if(IsAnyDead(client_p))
 341                 return;
 342         /*
 343          * Update messages received
 344          */
 345         ++me.localClient->receiveM;
 346         ++client_p->localClient->receiveM;
 347
 348         /*
 349          * Update bytes received
 350          */
 351         client_p->localClient->receiveB += length;
 352
 353         if(client_p->localClient->receiveB > 1023)
 354         {
 355                 client_p->localClient->receiveK += (client_p->localClient->receiveB >> 10);
 356                 client_p->localClient->receiveB &= 0x03ff;      /* 2^10 = 1024, 3ff = 1023 */
 357         }
 358
 359         me.localClient->receiveB += length;
 360
 361         if(me.localClient->receiveB > 1023)
 362         {
 363                 me.localClient->receiveK += (me.localClient->receiveB >> 10);
 364                 me.localClient->receiveB &= 0x03ff;
 365         }
 366
 367         parse(client_p, buffer, buffer + length);
 368 }