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 "struct.h"
  28 #include "s_conf.h"
  29 #include "s_serv.h"
  30 #include "client.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 "common.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 /*
  44  * parse_client_queued - parse client queued messages
  45  */
  46 static void
  47 parse_client_queued(struct Client *client_p)
  48 {
  49         int dolen = 0;
  50         int checkflood = 1;
  51
  52         if(IsAnyDead(client_p))
  53                 return;
  54
  55         if(IsUnknown(client_p))
  56         {
  57                 for (;;)
  58                 {
  59                         if(client_p->localClient->sent_parsed >= client_p->localClient->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
  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 /*
 151  * flood_recalc
 152  *
 153  * recalculate the number of allowed flood lines. this should be called
 154  * once a second on any given client. We then attempt to flush some data.
 155  */
 156 void
 157 flood_recalc(void *unused)
 158 {
 159         rb_dlink_node *ptr, *next;
 160         struct Client *client_p;
 161
 162         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 163         {
 164                 client_p = ptr->data;
 165
 166                 if(unlikely(IsMe(client_p)))
 167                         continue;
 168
 169                 if(unlikely(client_p->localClient == NULL))
 170                         continue;
 171
 172                 if(IsFloodDone(client_p))
 173                         client_p->localClient->sent_parsed -= 2;
 174                 else
 175                         client_p->localClient->sent_parsed = 0;
 176
 177                 if(client_p->localClient->sent_parsed < 0)
 178                         client_p->localClient->sent_parsed = 0;
 179
 180                 if(--client_p->localClient->actually_read < 0)
 181                         client_p->localClient->actually_read = 0;
 182
 183                 parse_client_queued(client_p);
 184
 185                 if(unlikely(IsAnyDead(client_p)))
 186                         continue;
 187
 188         }
 189
 190         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 191         {
 192                 client_p = ptr->data;
 193
 194                 if(client_p->localClient == NULL)
 195                         continue;
 196
 197                 client_p->localClient->sent_parsed--;
 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 }
 208
 209
 210 /*
 211  * read_packet - Read a 'packet' of data from a connection and process it.
 212  */
 213 void
 214 read_packet(rb_fde_t *F, void *data)
 215 {
 216         struct Client *client_p = data;
 217         struct LocalUser *lclient_p = client_p->localClient;
 218         int length = 0;
 219         int lbuf_len;
 220
 221         int binary = 0;
 222 #ifdef USE_IODEBUG_HOOKS
 223         hook_data_int hdata;
 224 #endif
 225
 226
 227         while(1) /* note..for things like rt sigio to work you *must* loop on read until you get EAGAIN */
 228         {
 229                 if(IsAnyDead(client_p))
 230                         return;
 231
 232                 /*
 233                  * Read some data. We *used to* do anti-flood protection here, but
 234                  * I personally think it makes the code too hairy to make sane.
 235                  *     -- adrian
 236                  */
 237                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 238                 if(length < 0)
 239                 {
 240                         if(rb_ignore_errno(errno))
 241                         {
 242                                 rb_setselect(client_p->localClient->F,
 243                                                 RB_SELECT_READ, read_packet, client_p);
 244                         } else
 245                                 error_exit_client(client_p, length);
 246                         return;
 247                 } else
 248                 if(length == 0)
 249                 {
 250                         error_exit_client(client_p, length);
 251                         return;
 252                 }
 253
 254 #ifdef USE_IODEBUG_HOOKS
 255                 hdata.client = client_p;
 256                 hdata.arg1 = readBuf;
 257                 hdata.arg2 = length;
 258                 call_hook(h_iorecv_id, &hdata);
 259 #endif
 260
 261                 if(client_p->localClient->lasttime < rb_current_time())
 262                         client_p->localClient->lasttime = rb_current_time();
 263                         client_p->flags &= ~FLAGS_PINGSENT;
 264
 265                 /*
 266                  * Before we even think of parsing what we just read, stick
 267                  * it on the end of the receive queue and do it when its
 268                  * turn comes around.
 269                  */
 270                 if(IsHandshake(client_p) || IsUnknown(client_p))
 271                         binary = 1;
 272
 273                 lbuf_len = rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 274
 275                 lclient_p->actually_read += lbuf_len;
 276
 277                 if(IsAnyDead(client_p))
 278                         return;
 279
 280                 /* Attempt to parse what we have */
 281                 parse_client_queued(client_p);
 282
 283                 if(IsAnyDead(client_p))
 284                         return;
 285
 286                 /* Check to make sure we're not flooding */
 287                 if(!IsAnyServer(client_p) &&
 288                    (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood))
 289                 {
 290                         if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 291                         {
 292                                 exit_client(client_p, client_p, client_p, "Excess Flood");
 293                                 return;
 294                         }
 295
 296                 }
 297
 298                 /* bail if short read */
 299                 if(length < READBUF_SIZE)
 300                 {
 301                         rb_setselect(client_p->localClient->F, RB_SELECT_READ, read_packet, client_p);
 302                         return;
 303                 }
 304         }
 305 }
 306
 307 /*
 308  * client_dopacket - copy packet to client buf and parse it
 309  *      client_p - pointer to client structure for which the buffer data
 310  *             applies.
 311  *      buffer - pointr to the buffer containing the newly read data
 312  *      length - number of valid bytes of data in the buffer
 313  *
 314  * Note:
 315  *      It is implicitly assumed that dopacket is called only
 316  *      with client_p of "local" variation, which contains all the
 317  *      necessary fields (buffer etc..)
 318  */
 319 void
 320 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 321 {
 322         s_assert(client_p != NULL);
 323         s_assert(buffer != NULL);
 324
 325         if(client_p == NULL || buffer == NULL)
 326                 return;
 327         if(IsAnyDead(client_p))
 328                 return;
 329         /*
 330          * Update messages received
 331          */
 332         ++me.localClient->receiveM;
 333         ++client_p->localClient->receiveM;
 334
 335         /*
 336          * Update bytes received
 337          */
 338         client_p->localClient->receiveB += length;
 339         me.localClient->receiveB += length;
 340
 341         parse(client_p, buffer, buffer + length);
 342 }
 343
 344 /* flood_endgrace()
 345  *
 346  * marks the end of the clients grace period
 347  */
 348 void
 349 flood_endgrace(struct Client *client_p)
 350 {
 351         SetFloodDone(client_p);
 352
 353         /* Drop their flood limit back down */
 354         client_p->localClient->allow_read = MAX_FLOOD;
 355
 356         /* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
 357          * so reset it.
 358          */
 359         client_p->localClient->sent_parsed = 0;
 360 }