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
  38 static char readBuf[READBUF_SIZE];
  39 static void client_dopacket(struct Client *client_p, char *buffer, size_t length);
  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 allow_read;
  49
  50         if(IsAnyDead(client_p))
  51                 return;
  52
  53         if(IsUnknown(client_p))
  54         {
  55                 allow_read = ConfigFileEntry.client_flood_burst_max;
  56                 for (;;)
  57                 {
  58                         if(client_p->localClient->sent_parsed >= 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                 if(IsFloodDone(client_p))
 101                         allow_read = ConfigFileEntry.client_flood_burst_max;
 102                 else
 103                         allow_read = ConfigFileEntry.client_flood_burst_rate;
 104                 /* allow opers 4 times the amount of messages as users. why 4?
 105                  * why not. :) --fl_
 106                  */
 107                 if(IsOper(client_p) && ConfigFileEntry.no_oper_flood)
 108                         allow_read *= 4;
 109                 /*
 110                  * Handle flood protection here - if we exceed our flood limit on
 111                  * messages in this loop, we simply drop out of the loop prematurely.
 112                  *   -- adrian
 113                  */
 114                 for (;;)
 115                 {
 116                         /* This flood protection works as follows:
 117                          *
 118                          * A client is given allow_read lines to send to the server.  Every
 119                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 120                          * is decreased by 1 every time flood_recalc is called.
 121                          *
 122                          * Thus a client can 'burst' allow_read lines to the server, any
 123                          * excess lines will be parsed one per flood_recalc() call.
 124                          *
 125                          * Therefore a client will be penalised more if they keep flooding,
 126                          * as sent_parsed will always hover around the allow_read limit
 127                          * and no 'bursts' will be permitted.
 128                          */
 129                         if(client_p->localClient->sent_parsed >= allow_read)
 130                                 break;
 131
 132                         dolen = rb_linebuf_get(&client_p->localClient->
 133                                             buf_recvq, readBuf, READBUF_SIZE,
 134                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 135
 136                         if(!dolen)
 137                                 break;
 138
 139                         client_dopacket(client_p, readBuf, dolen);
 140                         if(IsAnyDead(client_p))
 141                                 return;
 142
 143                         client_p->localClient->sent_parsed += ConfigFileEntry.client_flood_message_time;
 144                 }
 145         }
 146 }
 147
 148 /* flood_endgrace()
 149  *
 150  * marks the end of the clients grace period
 151  */
 152 void
 153 flood_endgrace(struct Client *client_p)
 154 {
 155         SetFloodDone(client_p);
 156
 157         /* sent_parsed could be way over client_flood_burst_max but under
 158          * client_flood_burst_rate so reset it.
 159          */
 160         client_p->localClient->sent_parsed = 0;
 161 }
 162
 163 /*
 164  * flood_recalc
 165  *
 166  * recalculate the number of allowed flood lines. this should be called
 167  * once a second on any given client. We then attempt to flush some data.
 168  */
 169 void
 170 flood_recalc(void *unused)
 171 {
 172         rb_dlink_node *ptr, *next;
 173         struct Client *client_p;
 174
 175         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 176         {
 177                 client_p = ptr->data;
 178
 179                 if(rb_unlikely(IsMe(client_p)))
 180                         continue;
 181
 182                 if(rb_unlikely(client_p->localClient == NULL))
 183                         continue;
 184
 185                 if(IsFloodDone(client_p))
 186                         client_p->localClient->sent_parsed -= ConfigFileEntry.client_flood_message_num;
 187                 else
 188                         client_p->localClient->sent_parsed = 0;
 189
 190                 if(client_p->localClient->sent_parsed < 0)
 191                         client_p->localClient->sent_parsed = 0;
 192
 193                 parse_client_queued(client_p);
 194
 195                 if(rb_unlikely(IsAnyDead(client_p)))
 196                         continue;
 197
 198         }
 199
 200         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 201         {
 202                 client_p = ptr->data;
 203
 204                 if(client_p->localClient == NULL)
 205                         continue;
 206
 207                 client_p->localClient->sent_parsed--;
 208
 209                 if(client_p->localClient->sent_parsed < 0)
 210                         client_p->localClient->sent_parsed = 0;
 211
 212                 parse_client_queued(client_p);
 213         }
 214 }
 215
 216 /*
 217  * read_packet - Read a 'packet' of data from a connection and process it.
 218  */
 219 void
 220 read_packet(rb_fde_t * F, void *data)
 221 {
 222         struct Client *client_p = data;
 223         int length = 0;
 224         int lbuf_len;
 225
 226         int binary = 0;
 227 #ifdef USE_IODEBUG_HOOKS
 228         hook_data_int hdata;
 229 #endif
 230
 231         while(1)
 232         {
 233                 if(IsAnyDead(client_p))
 234                         return;
 235
 236                 /*
 237                  * Read some data. We *used to* do anti-flood protection here, but
 238                  * I personally think it makes the code too hairy to make sane.
 239                  *     -- adrian
 240                  */
 241                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 242
 243                 if(length < 0)
 244                 {
 245                         if(rb_ignore_errno(errno))
 246                                 rb_setselect(client_p->localClient->F,
 247                                                 RB_SELECT_READ, read_packet, client_p);
 248                         else
 249                                 error_exit_client(client_p, length);
 250                         return;
 251                 }
 252                 else if(length == 0)
 253                 {
 254                         error_exit_client(client_p, length);
 255                         return;
 256                 }
 257
 258 #ifdef USE_IODEBUG_HOOKS
 259                 hdata.client = client_p;
 260                 hdata.arg1 = readBuf;
 261                 hdata.arg2 = length;
 262                 call_hook(h_iorecv_id, &hdata);
 263 #endif
 264
 265                 if(client_p->localClient->lasttime < rb_current_time())
 266                         client_p->localClient->lasttime = rb_current_time();
 267                 client_p->flags &= ~FLAGS_PINGSENT;
 268
 269                 /*
 270                  * Before we even think of parsing what we just read, stick
 271                  * it on the end of the receive queue and do it when its
 272                  * turn comes around.
 273                  */
 274                 if(IsHandshake(client_p) || IsUnknown(client_p))
 275                         binary = 1;
 276
 277                 lbuf_len = rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 278
 279                 if(IsAnyDead(client_p))
 280                         return;
 281
 282                 /* Attempt to parse what we have */
 283                 parse_client_queued(client_p);
 284
 285                 if(IsAnyDead(client_p))
 286                         return;
 287
 288                 /* Check to make sure we're not flooding */
 289                 if(!IsAnyServer(client_p) &&
 290                    (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood_max_lines))
 291                 {
 292                         if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 293                         {
 294                                 exit_client(client_p, client_p, client_p, "Excess Flood");
 295                                 return;
 296                         }
 297                 }
 298
 299                 /* bail if short read */
 300                 if(length < READBUF_SIZE)
 301                 {
 302                         rb_setselect(client_p->localClient->F, RB_SELECT_READ, read_packet, client_p);
 303                         return;
 304                 }
 305         }
 306 }
 307
 308 /*
 309  * client_dopacket - copy packet to client buf and parse it
 310  *      client_p - pointer to client structure for which the buffer data
 311  *             applies.
 312  *      buffer - pointr to the buffer containing the newly read data
 313  *      length - number of valid bytes of data in the buffer
 314  *
 315  * Note:
 316  *      It is implicitly assumed that dopacket is called only
 317  *      with client_p of "local" variation, which contains all the
 318  *      necessary fields (buffer etc..)
 319  */
 320 void
 321 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 322 {
 323         s_assert(client_p != NULL);
 324         s_assert(buffer != NULL);
 325
 326         if(client_p == NULL || buffer == NULL)
 327                 return;
 328         if(IsAnyDead(client_p))
 329                 return;
 330         /*
 331          * Update messages received
 332          */
 333         ++me.localClient->receiveM;
 334         ++client_p->localClient->receiveM;
 335
 336         /*
 337          * Update bytes received
 338          */
 339         client_p->localClient->receiveB += length;
 340
 341         if(client_p->localClient->receiveB > 1023)
 342         {
 343                 client_p->localClient->receiveK += (client_p->localClient->receiveB >> 10);
 344                 client_p->localClient->receiveB &= 0x03ff;      /* 2^10 = 1024, 3ff = 1023 */
 345         }
 346
 347         me.localClient->receiveB += length;
 348
 349         if(me.localClient->receiveB > 1023)
 350         {
 351                 me.localClient->receiveK += (me.localClient->receiveB >> 10);
 352                 me.localClient->receiveB &= 0x03ff;
 353         }
 354
 355         parse(client_p, buffer, buffer + length);
 356 }