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
  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         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                         checkflood = 0;
 102                 /*
 103                  * Handle flood protection here - if we exceed our flood limit on
 104                  * messages in this loop, we simply drop out of the loop prematurely.
 105                  *   -- adrian
 106                  */
 107                 for (;;)
 108                 {
 109                         /* This flood protection works as follows:
 110                          *
 111                          * A client is given allow_read lines to send to the server.  Every
 112                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 113                          * is decreased by 1 every time flood_recalc is called.
 114                          *
 115                          * Thus a client can 'burst' allow_read lines to the server, any
 116                          * excess lines will be parsed one per flood_recalc() call.
 117                          *
 118                          * Therefore a client will be penalised more if they keep flooding,
 119                          * as sent_parsed will always hover around the allow_read limit
 120                          * and no 'bursts' will be permitted.
 121                          */
 122                         if(checkflood)
 123                         {
 124                                 if(client_p->localClient->sent_parsed >= client_p->localClient->allow_read)
 125                                         break;
 126                         }
 127
 128                         /* allow opers 4 times the amount of messages as users. why 4?
 129                          * why not. :) --fl_
 130                          */
 131                         else if(client_p->localClient->sent_parsed >= (4 * client_p->localClient->allow_read))
 132                                 break;
 133
 134                         dolen = rb_linebuf_get(&client_p->localClient->
 135                                             buf_recvq, readBuf, READBUF_SIZE,
 136                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 137
 138                         if(!dolen)
 139                                 break;
 140
 141                         client_dopacket(client_p, readBuf, dolen);
 142                         if(IsAnyDead(client_p))
 143                                 return;
 144                         client_p->localClient->sent_parsed++;
 145                 }
 146         }
 147 }
 148
 149 /*
 150  * flood_recalc
 151  *
 152  * recalculate the number of allowed flood lines. this should be called
 153  * once a second on any given client. We then attempt to flush some data.
 154  */
 155 void
 156 flood_recalc(void *unused)
 157 {
 158         rb_dlink_node *ptr, *next;
 159         struct Client *client_p;
 160
 161         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 162         {
 163                 client_p = ptr->data;
 164
 165                 if(unlikely(IsMe(client_p)))
 166                         continue;
 167
 168                 if(unlikely(client_p->localClient == NULL))
 169                         continue;
 170
 171                 if(IsFloodDone(client_p))
 172                         client_p->localClient->sent_parsed -= 2;
 173                 else
 174                         client_p->localClient->sent_parsed = 0;
 175
 176                 if(client_p->localClient->sent_parsed < 0)
 177                         client_p->localClient->sent_parsed = 0;
 178
 179                 if(--client_p->localClient->actually_read < 0)
 180                         client_p->localClient->actually_read = 0;
 181
 182                 parse_client_queued(client_p);
 183
 184                 if(unlikely(IsAnyDead(client_p)))
 185                         continue;
 186
 187         }
 188
 189         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 190         {
 191                 client_p = ptr->data;
 192
 193                 if(client_p->localClient == NULL)
 194                         continue;
 195
 196                 client_p->localClient->sent_parsed--;
 197
 198                 if(client_p->localClient->sent_parsed < 0)
 199                         client_p->localClient->sent_parsed = 0;
 200
 201                 if(--client_p->localClient->actually_read < 0)
 202                         client_p->localClient->actually_read = 0;
 203
 204                 parse_client_queued(client_p);
 205        }
 206 }
 207
 208
 209 /*
 210  * read_packet - Read a 'packet' of data from a connection and process it.
 211  */
 212 void
 213 read_packet(rb_fde_t *F, void *data)
 214 {
 215         struct Client *client_p = data;
 216         struct LocalUser *lclient_p = client_p->localClient;
 217         int length = 0;
 218         int lbuf_len;
 219
 220         int binary = 0;
 221 #ifdef USE_IODEBUG_HOOKS
 222         hook_data_int hdata;
 223 #endif
 224
 225
 226         while(1) /* note..for things like rt sigio to work you *must* loop on read until you get EAGAIN */
 227         {
 228                 if(IsAnyDead(client_p))
 229                         return;
 230
 231                 /*
 232                  * Read some data. We *used to* do anti-flood protection here, but
 233                  * I personally think it makes the code too hairy to make sane.
 234                  *     -- adrian
 235                  */
 236                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 237                 if(length < 0)
 238                 {
 239                         if(rb_ignore_errno(errno))
 240                         {
 241                                 rb_setselect(client_p->localClient->F,
 242                                                 RB_SELECT_READ, read_packet, client_p);
 243                         } else
 244                                 error_exit_client(client_p, length);
 245                         return;
 246                 } else
 247                 if(length == 0)
 248                 {
 249                         error_exit_client(client_p, length);
 250                         return;
 251                 }
 252
 253 #ifdef USE_IODEBUG_HOOKS
 254                 hdata.client = client_p;
 255                 hdata.arg1 = readBuf;
 256                 hdata.arg2 = length;
 257                 call_hook(h_iorecv_id, &hdata);
 258 #endif
 259
 260                 if(client_p->localClient->lasttime < rb_current_time())
 261                         client_p->localClient->lasttime = rb_current_time();
 262                         client_p->flags &= ~FLAGS_PINGSENT;
 263
 264                 /*
 265                  * Before we even think of parsing what we just read, stick
 266                  * it on the end of the receive queue and do it when its
 267                  * turn comes around.
 268                  */
 269                 if(IsHandshake(client_p) || IsUnknown(client_p))
 270                         binary = 1;
 271
 272                 lbuf_len = rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 273
 274                 lclient_p->actually_read += lbuf_len;
 275
 276                 if(IsAnyDead(client_p))
 277                         return;
 278
 279                 /* Attempt to parse what we have */
 280                 parse_client_queued(client_p);
 281
 282                 if(IsAnyDead(client_p))
 283                         return;
 284
 285                 /* Check to make sure we're not flooding */
 286                 if(!IsAnyServer(client_p) &&
 287                    (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood))
 288                 {
 289                         if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 290                         {
 291                                 exit_client(client_p, client_p, client_p, "Excess Flood");
 292                                 return;
 293                         }
 294
 295                 }
 296
 297                 /* bail if short read */
 298                 if(length < READBUF_SIZE)
 299                 {
 300                         rb_setselect(client_p->localClient->F, RB_SELECT_READ, read_packet, client_p);
 301                         return;
 302                 }
 303         }
 304 }
 305
 306 /*
 307  * client_dopacket - copy packet to client buf and parse it
 308  *      client_p - pointer to client structure for which the buffer data
 309  *             applies.
 310  *      buffer - pointr to the buffer containing the newly read data
 311  *      length - number of valid bytes of data in the buffer
 312  *
 313  * Note:
 314  *      It is implicitly assumed that dopacket is called only
 315  *      with client_p of "local" variation, which contains all the
 316  *      necessary fields (buffer etc..)
 317  */
 318 void
 319 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 320 {
 321         s_assert(client_p != NULL);
 322         s_assert(buffer != NULL);
 323
 324         if(client_p == NULL || buffer == NULL)
 325                 return;
 326         if(IsAnyDead(client_p))
 327                 return;
 328         /*
 329          * Update messages received
 330          */
 331         ++me.localClient->receiveM;
 332         ++client_p->localClient->receiveM;
 333
 334         /*
 335          * Update bytes received
 336          */
 337         client_p->localClient->receiveB += length;
 338         me.localClient->receiveB += length;
 339
 340         parse(client_p, buffer, buffer + length);
 341 }
 342
 343 /* flood_endgrace()
 344  *
 345  * marks the end of the clients grace period
 346  */
 347 void
 348 flood_endgrace(struct Client *client_p)
 349 {
 350         SetFloodDone(client_p);
 351
 352         /* Drop their flood limit back down */
 353         client_p->localClient->allow_read = MAX_FLOOD;
 354
 355         /* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
 356          * so reset it.
 357          */
 358         client_p->localClient->sent_parsed = 0;
 359 }