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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
  22  *  USA
  23  *
  24  *  $Id: packet.c 25179 2008-03-30 16:34:57Z androsyn $
  25  */
  26 #include "stdinc.h"
  27 #include "s_conf.h"
  28 #include "s_serv.h"
  29 #include "client.h"
  30 #include "ircd.h"
  31 #include "parse.h"
  32 #include "packet.h"
  33 #include "hook.h"
  34 #include "send.h"
  35 #include "common.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         if(IsAnyServer(client_p) || IsExemptFlood(client_p))
  88         {
  89                 while (!IsAnyDead(client_p) && (dolen = rb_linebuf_get(&client_p->localClient->buf_recvq,
  90                                            readBuf, READBUF_SIZE, LINEBUF_COMPLETE,
  91                                            LINEBUF_PARSED)) > 0)
  92                 {
  93                         client_dopacket(client_p, readBuf, dolen);
  94                 }
  95         }
  96         else if(IsClient(client_p))
  97         {
  98
  99                 if(IsOper(client_p) && ConfigFileEntry.no_oper_flood)
 100                         checkflood = 0;
 101                 /*
 102                  * Handle flood protection here - if we exceed our flood limit on
 103                  * messages in this loop, we simply drop out of the loop prematurely.
 104                  *   -- adrian
 105                  */
 106                 for (;;)
 107                 {
 108                         /* This flood protection works as follows:
 109                          *
 110                          * A client is given allow_read lines to send to the server.  Every
 111                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 112                          * is decreased by 1 every time flood_recalc is called.
 113                          *
 114                          * Thus a client can 'burst' allow_read lines to the server, any
 115                          * excess lines will be parsed one per flood_recalc() call.
 116                          *
 117                          * Therefore a client will be penalised more if they keep flooding,
 118                          * as sent_parsed will always hover around the allow_read limit
 119                          * and no 'bursts' will be permitted.
 120                          */
 121                         if(checkflood)
 122                         {
 123                                 if(client_p->localClient->sent_parsed >= client_p->localClient->allow_read)
 124                                         break;
 125                         }
 126
 127                         /* allow opers 4 times the amount of messages as users. why 4?
 128                          * why not. :) --fl_
 129                          */
 130                         else if(client_p->localClient->sent_parsed >= (4 * client_p->localClient->allow_read))
 131                                 break;
 132
 133                         dolen = rb_linebuf_get(&client_p->localClient->
 134                                             buf_recvq, readBuf, READBUF_SIZE,
 135                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 136
 137                         if(!dolen)
 138                                 break;
 139
 140                         client_dopacket(client_p, readBuf, dolen);
 141                         if(IsAnyDead(client_p))
 142                                 return;
 143                         client_p->localClient->sent_parsed++;
 144                 }
 145         }
 146 }
 147
 148 /*
 149  * flood_recalc
 150  *
 151  * recalculate the number of allowed flood lines. this should be called
 152  * once a second on any given client. We then attempt to flush some data.
 153  */
 154 void
 155 flood_recalc(void *unused)
 156 {
 157         rb_dlink_node *ptr, *next;
 158         struct Client *client_p;
 159
 160         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 161         {
 162                 client_p = ptr->data;
 163
 164                 if(unlikely(IsMe(client_p)))
 165                         continue;
 166
 167                 if(unlikely(client_p->localClient == NULL))
 168                         continue;
 169
 170                 if(IsFloodDone(client_p))
 171                         client_p->localClient->sent_parsed -= 2;
 172                 else
 173                         client_p->localClient->sent_parsed = 0;
 174
 175                 if(client_p->localClient->sent_parsed < 0)
 176                         client_p->localClient->sent_parsed = 0;
 177
 178                 if(--client_p->localClient->actually_read < 0)
 179                         client_p->localClient->actually_read = 0;
 180
 181                 parse_client_queued(client_p);
 182
 183                 if(unlikely(IsAnyDead(client_p)))
 184                         continue;
 185
 186         }
 187
 188         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 189         {
 190                 client_p = ptr->data;
 191
 192                 if(client_p->localClient == NULL)
 193                         continue;
 194
 195                 client_p->localClient->sent_parsed--;
 196
 197                 if(client_p->localClient->sent_parsed < 0)
 198                         client_p->localClient->sent_parsed = 0;
 199
 200                 if(--client_p->localClient->actually_read < 0)
 201                         client_p->localClient->actually_read = 0;
 202
 203                 parse_client_queued(client_p);
 204        }
 205 }
 206
 207
 208 /*
 209  * read_packet - Read a 'packet' of data from a connection and process it.
 210  */
 211 void
 212 read_packet(rb_fde_t *F, void *data)
 213 {
 214         struct Client *client_p = data;
 215         struct LocalUser *lclient_p = client_p->localClient;
 216         int length = 0;
 217         int lbuf_len;
 218
 219         int binary = 0;
 220 #ifdef USE_IODEBUG_HOOKS
 221         hook_data_int hdata;
 222 #endif
 223
 224
 225         while(1) /* note..for things like rt sigio to work you *must* loop on read until you get EAGAIN */
 226         {
 227                 if(IsAnyDead(client_p))
 228                         return;
 229
 230                 /*
 231                  * Read some data. We *used to* do anti-flood protection here, but
 232                  * I personally think it makes the code too hairy to make sane.
 233                  *     -- adrian
 234                  */
 235                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 236                 if(length < 0)
 237                 {
 238                         if(rb_ignore_errno(errno))
 239                         {
 240                                 rb_setselect(client_p->localClient->F,
 241                                                 RB_SELECT_READ, read_packet, client_p);
 242                         } else
 243                                 error_exit_client(client_p, length);
 244                         return;
 245                 } else
 246                 if(length == 0)
 247                 {
 248                         error_exit_client(client_p, length);
 249                         return;
 250                 }
 251
 252 #ifdef USE_IODEBUG_HOOKS
 253                 hdata.client = client_p;
 254                 hdata.arg1 = readBuf;
 255                 hdata.arg2 = length;
 256                 call_hook(h_iorecv_id, &hdata);
 257 #endif
 258
 259                 if(client_p->localClient->lasttime < rb_current_time())
 260                         client_p->localClient->lasttime = rb_current_time();
 261                         client_p->flags &= ~FLAGS_PINGSENT;
 262
 263                 /*
 264                  * Before we even think of parsing what we just read, stick
 265                  * it on the end of the receive queue and do it when its
 266                  * turn comes around.
 267                  */
 268                 if(IsHandshake(client_p) || IsUnknown(client_p))
 269                         binary = 1;
 270
 271                 lbuf_len = rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 272
 273                 lclient_p->actually_read += lbuf_len;
 274
 275                 if(IsAnyDead(client_p))
 276                         return;
 277
 278                 /* Attempt to parse what we have */
 279                 parse_client_queued(client_p);
 280
 281                 if(IsAnyDead(client_p))
 282                         return;
 283
 284                 /* Check to make sure we're not flooding */
 285                 if(!IsAnyServer(client_p) &&
 286                    (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood))
 287                 {
 288                         if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 289                         {
 290                                 exit_client(client_p, client_p, client_p, "Excess Flood");
 291                                 return;
 292                         }
 293
 294                 }
 295
 296                 /* bail if short read */
 297                 if(length < READBUF_SIZE)
 298                 {
 299                         rb_setselect(client_p->localClient->F, RB_SELECT_READ, read_packet, client_p);
 300                         return;
 301                 }
 302         }
 303 }
 304
 305 /*
 306  * client_dopacket - copy packet to client buf and parse it
 307  *      client_p - pointer to client structure for which the buffer data
 308  *             applies.
 309  *      buffer - pointr to the buffer containing the newly read data
 310  *      length - number of valid bytes of data in the buffer
 311  *
 312  * Note:
 313  *      It is implicitly assumed that dopacket is called only
 314  *      with client_p of "local" variation, which contains all the
 315  *      necessary fields (buffer etc..)
 316  */
 317 void
 318 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 319 {
 320         s_assert(client_p != NULL);
 321         s_assert(buffer != NULL);
 322
 323         if(client_p == NULL || buffer == NULL)
 324                 return;
 325         if(IsAnyDead(client_p))
 326                 return;
 327         /*
 328          * Update messages received
 329          */
 330         ++me.localClient->receiveM;
 331         ++client_p->localClient->receiveM;
 332
 333         /*
 334          * Update bytes received
 335          */
 336         client_p->localClient->receiveB += length;
 337         me.localClient->receiveB += length;
 338
 339         parse(client_p, buffer, buffer + length);
 340 }
 341
 342 /* flood_endgrace()
 343  *
 344  * marks the end of the clients grace period
 345  */
 346 void
 347 flood_endgrace(struct Client *client_p)
 348 {
 349         SetFloodDone(client_p);
 350
 351         /* Drop their flood limit back down */
 352         client_p->localClient->allow_read = MAX_FLOOD;
 353
 354         /* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
 355          * so reset it.
 356          */
 357         client_p->localClient->sent_parsed = 0;
 358 }