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 "ircd.h"
  29 #include "parse.h"
  30 #include "packet.h"
  31 #include "match.h"
  32 #include "hook.h"
  33 #include "send.h"
  34 #include "s_assert.h"
  35 #include "s_newconf.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(IsOperGeneral(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                         /* post_registration_delay hack. Don't process any messages from a new client for $n seconds,
 138                          * to allow network bots to do their thing before channels can be joined.
 139                          */
 140                         if (rb_current_time() < client_p->localClient->firsttime + ConfigFileEntry.post_registration_delay)
 141                                 break;
 142
 143                         dolen = rb_linebuf_get(&client_p->localClient->
 144                                             buf_recvq, readBuf, READBUF_SIZE,
 145                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 146
 147                         if(!dolen)
 148                                 break;
 149
 150                         client_dopacket(client_p, readBuf, dolen);
 151                         if(IsAnyDead(client_p))
 152                                 return;
 153
 154                         client_p->localClient->sent_parsed += ConfigFileEntry.client_flood_message_time;
 155                 }
 156                 /* If sent_parsed is impossibly high, drop it down.
 157                  * This is useful if the configuration is changed.
 158                  */
 159                 if(client_p->localClient->sent_parsed > allow_read +
 160                                 ConfigFileEntry.client_flood_message_time - 1)
 161                         client_p->localClient->sent_parsed = allow_read +
 162                                 ConfigFileEntry.client_flood_message_time - 1;
 163         }
 164 }
 165
 166 /* flood_endgrace()
 167  *
 168  * marks the end of the clients grace period
 169  */
 170 void
 171 flood_endgrace(struct Client *client_p)
 172 {
 173         SetFloodDone(client_p);
 174
 175         /* sent_parsed could be way over client_flood_burst_max but under
 176          * client_flood_burst_rate so reset it.
 177          */
 178         client_p->localClient->sent_parsed = 0;
 179 }
 180
 181 /*
 182  * flood_recalc
 183  *
 184  * recalculate the number of allowed flood lines. this should be called
 185  * once a second on any given client. We then attempt to flush some data.
 186  */
 187 void
 188 flood_recalc(void *unused)
 189 {
 190         rb_dlink_node *ptr, *next;
 191         struct Client *client_p;
 192
 193         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 194         {
 195                 client_p = ptr->data;
 196
 197                 if(rb_unlikely(IsMe(client_p)))
 198                         continue;
 199
 200                 if(rb_unlikely(client_p->localClient == NULL))
 201                         continue;
 202
 203                 if(IsFloodDone(client_p))
 204                         client_p->localClient->sent_parsed -= ConfigFileEntry.client_flood_message_num;
 205                 else
 206                         client_p->localClient->sent_parsed = 0;
 207
 208                 if(client_p->localClient->sent_parsed < 0)
 209                         client_p->localClient->sent_parsed = 0;
 210
 211                 parse_client_queued(client_p);
 212
 213                 if(rb_unlikely(IsAnyDead(client_p)))
 214                         continue;
 215
 216         }
 217
 218         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 219         {
 220                 client_p = ptr->data;
 221
 222                 if(client_p->localClient == NULL)
 223                         continue;
 224
 225                 client_p->localClient->sent_parsed--;
 226
 227                 if(client_p->localClient->sent_parsed < 0)
 228                         client_p->localClient->sent_parsed = 0;
 229
 230                 parse_client_queued(client_p);
 231         }
 232 }
 233
 234 /*
 235  * read_packet - Read a 'packet' of data from a connection and process it.
 236  */
 237 void
 238 read_packet(rb_fde_t * F, void *data)
 239 {
 240         struct Client *client_p = data;
 241         int length = 0;
 242         int binary = 0;
 243
 244         while(1)
 245         {
 246                 if(IsAnyDead(client_p))
 247                         return;
 248
 249                 /*
 250                  * Read some data. We *used to* do anti-flood protection here, but
 251                  * I personally think it makes the code too hairy to make sane.
 252                  *     -- adrian
 253                  */
 254                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 255
 256                 if(length < 0)
 257                 {
 258                         if(rb_ignore_errno(errno))
 259                                 rb_setselect(client_p->localClient->F,
 260                                                 RB_SELECT_READ, read_packet, client_p);
 261                         else
 262                                 error_exit_client(client_p, length);
 263                         return;
 264                 }
 265                 else if(length == 0)
 266                 {
 267                         error_exit_client(client_p, length);
 268                         return;
 269                 }
 270
 271                 if(client_p->localClient->lasttime < rb_current_time())
 272                         client_p->localClient->lasttime = rb_current_time();
 273                 client_p->flags &= ~FLAGS_PINGSENT;
 274
 275                 if (client_p->flags & FLAGS_PINGWARN)
 276                 {
 277                         /*
 278                          * if we warned about this server being unresponsive
 279                          * before, let's let everyone know there's no need
 280                          * to panic
 281                          */
 282                         client_p->flags &= ~FLAGS_PINGWARN;
 283                         sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
 284                                 "Received response from previously unresponsive link %s",
 285                                 client_p->name);
 286                         ilog(L_SERVER,
 287                                 "Received response from previously unresponsive link %s",
 288                                 log_client_name(client_p, HIDE_IP));
 289                 }
 290
 291
 292                 /*
 293                  * Before we even think of parsing what we just read, stick
 294                  * it on the end of the receive queue and do it when its
 295                  * turn comes around.
 296                  */
 297                 if(IsHandshake(client_p) || IsUnknown(client_p))
 298                         binary = 1;
 299
 300                 (void) rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 301
 302                 if(IsAnyDead(client_p))
 303                         return;
 304
 305                 /* Attempt to parse what we have */
 306                 parse_client_queued(client_p);
 307
 308                 if(IsAnyDead(client_p))
 309                         return;
 310
 311                 /* Check to make sure we're not flooding */
 312                 if(!IsAnyServer(client_p) &&
 313                    (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood_max_lines))
 314                 {
 315                         if(!(ConfigFileEntry.no_oper_flood && IsOperGeneral(client_p)))
 316                         {
 317                                 exit_client(client_p, client_p, client_p, "Excess Flood");
 318                                 return;
 319                         }
 320                 }
 321
 322                 /* bail if short read, but not for SCTP as it returns data in packets */
 323                 if (length < READBUF_SIZE && !(rb_get_type(client_p->localClient->F) & RB_FD_SCTP)) {
 324                         rb_setselect(client_p->localClient->F, RB_SELECT_READ, read_packet, client_p);
 325                         return;
 326                 }
 327         }
 328 }
 329
 330 /*
 331  * client_dopacket - copy packet to client buf and parse it
 332  *      client_p - pointer to client structure for which the buffer data
 333  *             applies.
 334  *      buffer - pointr to the buffer containing the newly read data
 335  *      length - number of valid bytes of data in the buffer
 336  *
 337  * Note:
 338  *      It is implicitly assumed that dopacket is called only
 339  *      with client_p of "local" variation, which contains all the
 340  *      necessary fields (buffer etc..)
 341  */
 342 static void
 343 client_dopacket(struct Client *client_p, char *buffer, size_t length)
 344 {
 345         s_assert(client_p != NULL);
 346         s_assert(buffer != NULL);
 347
 348         if(client_p == NULL || buffer == NULL)
 349                 return;
 350         if(IsAnyDead(client_p))
 351                 return;
 352         /*
 353          * Update messages received
 354          */
 355         ++me.localClient->receiveM;
 356         ++client_p->localClient->receiveM;
 357
 358         /*
 359          * Update bytes received
 360          */
 361         client_p->localClient->receiveB += length;
 362
 363         if(client_p->localClient->receiveB > 1023)
 364         {
 365                 client_p->localClient->receiveK += (client_p->localClient->receiveB >> 10);
 366                 client_p->localClient->receiveB &= 0x03ff;      /* 2^10 = 1024, 3ff = 1023 */
 367         }
 368
 369         me.localClient->receiveB += length;
 370
 371         if(me.localClient->receiveB > 1023)
 372         {
 373                 me.localClient->receiveK += (me.localClient->receiveB >> 10);
 374                 me.localClient->receiveB &= 0x03ff;
 375         }
 376
 377         parse(client_p, buffer, buffer + length);
 378 }