ircd/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 #include "stdinc.h"
  25 #include "s_conf.h"
  26 #include "s_serv.h"
  27 #include "client.h"
  28 #include "common.h"
  29 #include "ircd.h"
  30 #include "parse.h"
  31 #include "packet.h"
  32 #include "match.h"
  33 #include "hook.h"
  34 #include "send.h"
  35 #include "s_assert.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  * parse_client_queued - parse client queued messages
  42  */
  43 static void
  44 parse_client_queued(struct Client *client_p)
  45 {
  46         int dolen = 0;
  47         int allow_read;
  48
  49         if(IsAnyDead(client_p))
  50                 return;
  51
  52         if(IsUnknown(client_p))
  53         {
  54                 allow_read = ConfigFileEntry.client_flood_burst_max;
  55                 for (;;)
  56                 {
  57                         if(client_p->localClient->sent_parsed >= 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                 /* If sent_parsed is impossibly high, drop it down.
  87                  * This is useful if the configuration is changed.
  88                  */
  89                 if(client_p->localClient->sent_parsed > allow_read)
  90                         client_p->localClient->sent_parsed = allow_read;
  91         }
  92
  93         if(IsAnyServer(client_p) || IsExemptFlood(client_p))
  94         {
  95                 while (!IsAnyDead(client_p) && (dolen = rb_linebuf_get(&client_p->localClient->buf_recvq,
  96                                            readBuf, READBUF_SIZE, LINEBUF_COMPLETE,
  97                                            LINEBUF_PARSED)) > 0)
  98                 {
  99                         client_dopacket(client_p, readBuf, dolen);
 100                 }
 101         }
 102         else if(IsClient(client_p))
 103         {
 104                 if(IsFloodDone(client_p))
 105                         allow_read = ConfigFileEntry.client_flood_burst_max;
 106                 else
 107                         allow_read = ConfigFileEntry.client_flood_burst_rate;
 108                 allow_read *= ConfigFileEntry.client_flood_message_time;
 109                 /* allow opers 4 times the amount of messages as users. why 4?
 110                  * why not. :) --fl_
 111                  */
 112                 if(IsOper(client_p) && ConfigFileEntry.no_oper_flood)
 113                         allow_read *= 4;
 114                 /*
 115                  * Handle flood protection here - if we exceed our flood limit on
 116                  * messages in this loop, we simply drop out of the loop prematurely.
 117                  *   -- adrian
 118                  */
 119                 for (;;)
 120                 {
 121                         /* This flood protection works as follows:
 122                          *
 123                          * A client is given allow_read lines to send to the server.  Every
 124                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 125                          * is decreased by 1 every time flood_recalc is called.
 126                          *
 127                          * Thus a client can 'burst' allow_read lines to the server, any
 128                          * excess lines will be parsed one per flood_recalc() call.
 129                          *
 130                          * Therefore a client will be penalised more if they keep flooding,
 131                          * as sent_parsed will always hover around the allow_read limit
 132                          * and no 'bursts' will be permitted.
 133                          */
 134                         if(client_p->localClient->sent_parsed >= allow_read)
 135                                 break;
 136
 137                         dolen = rb_linebuf_get(&client_p->localClient->
 138                                             buf_recvq, readBuf, READBUF_SIZE,
 139                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 140
 141                         if(!dolen)
 142                                 break;
 143
 144                         client_dopacket(client_p, readBuf, dolen);
 145                         if(IsAnyDead(client_p))
 146                                 return;
 147
 148                         client_p->localClient->sent_parsed += ConfigFileEntry.client_flood_message_time;
 149                 }
 150                 /* If sent_parsed is impossibly high, drop it down.
 151                  * This is useful if the configuration is changed.
 152                  */
 153                 if(client_p->localClient->sent_parsed > allow_read +
 154                                 ConfigFileEntry.client_flood_message_time - 1)
 155                         client_p->localClient->sent_parsed = allow_read +
 156                                 ConfigFileEntry.client_flood_message_time - 1;
 157         }
 158 }
 159
 160 /* flood_endgrace()
 161  *
 162  * marks the end of the clients grace period
 163  */
 164 void
 165 flood_endgrace(struct Client *client_p)
 166 {
 167         SetFloodDone(client_p);
 168
 169         /* sent_parsed could be way over client_flood_burst_max but under
 170          * client_flood_burst_rate so reset it.
 171          */
 172         client_p->localClient->sent_parsed = 0;
 173 }
 174
 175 /*
 176  * flood_recalc
 177  *
 178  * recalculate the number of allowed flood lines. this should be called
 179  * once a second on any given client. We then attempt to flush some data.
 180  */
 181 void
 182 flood_recalc(void *unused)
 183 {
 184         rb_dlink_node *ptr, *next;
 185         struct Client *client_p;
 186
 187         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 188         {
 189                 client_p = ptr->data;
 190
 191                 if(rb_unlikely(IsMe(client_p)))
 192                         continue;
 193
 194                 if(rb_unlikely(client_p->localClient == NULL))
 195                         continue;
 196
 197                 if(IsFloodDone(client_p))
 198                         client_p->localClient->sent_parsed -= ConfigFileEntry.client_flood_message_num;
 199                 else
 200                         client_p->localClient->sent_parsed = 0;
 201
 202                 if(client_p->localClient->sent_parsed < 0)
 203                         client_p->localClient->sent_parsed = 0;
 204
 205                 parse_client_queued(client_p);
 206
 207                 if(rb_unlikely(IsAnyDead(client_p)))
 208                         continue;
 209
 210         }
 211
 212         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 213         {
 214                 client_p = ptr->data;
 215
 216                 if(client_p->localClient == NULL)
 217                         continue;
 218
 219                 client_p->localClient->sent_parsed--;
 220
 221                 if(client_p->localClient->sent_parsed < 0)
 222                         client_p->localClient->sent_parsed = 0;
 223
 224                 parse_client_queued(client_p);
 225         }
 226 }
 227
 228 /*
 229  * read_packet - Read a 'packet' of data from a connection and process it.
 230  */
 231 void
 232 read_packet(rb_fde_t * F, void *data)
 233 {
 234         struct Client *client_p = data;
 235         int length = 0;
 236         int binary = 0;
 237
 238         while(1)
 239         {
 240                 if(IsAnyDead(client_p))
 241                         return;
 242
 243                 /*
 244                  * Read some data. We *used to* do anti-flood protection here, but
 245                  * I personally think it makes the code too hairy to make sane.
 246                  *     -- adrian
 247                  */
 248                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 249
 250                 if(length < 0)
 251                 {
 252                         if(rb_ignore_errno(errno))
 253                                 rb_setselect(client_p->localClient->F,
 254                                                 RB_SELECT_READ, read_packet, client_p);
 255                         else
 256                                 error_exit_client(client_p, length);
 257                         return;
 258                 }
 259                 else if(length == 0)
 260                 {
 261                         error_exit_client(client_p, length);
 262                         return;
 263                 }
 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                 (void) 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 }