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
  36 static char readBuf[READBUF_SIZE];
  37 static void client_dopacket(struct Client *client_p, char *buffer, size_t length);
  38
  39 /*
  40  * parse_client_queued - parse client queued messages
  41  */
  42 static void
  43 parse_client_queued(struct Client *client_p)
  44 {
  45         int dolen = 0;
  46         int allow_read;
  47
  48         if(IsAnyDead(client_p))
  49                 return;
  50
  51         if(IsUnknown(client_p))
  52         {
  53                 allow_read = ConfigFileEntry.client_flood_burst_max;
  54                 for (;;)
  55                 {
  56                         if(client_p->localClient->sent_parsed >= allow_read)
  57                                 break;
  58
  59                         dolen = rb_linebuf_get(&client_p->localClient->
  60                                             buf_recvq, readBuf, READBUF_SIZE,
  61                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
  62
  63                         if(dolen <= 0 || IsDead(client_p))
  64                                 break;
  65
  66                         client_dopacket(client_p, readBuf, dolen);
  67                         client_p->localClient->sent_parsed++;
  68
  69                         /* He's dead cap'n */
  70                         if(IsAnyDead(client_p))
  71                                 return;
  72                         /* if theyve dropped out of the unknown state, break and move
  73                          * to the parsing for their appropriate status.  --fl
  74                          */
  75                         if(!IsUnknown(client_p))
  76                         {
  77                                 /* reset their flood limits, they're now
  78                                  * graced to flood
  79                                  */
  80                                 client_p->localClient->sent_parsed = 0;
  81                                 break;
  82                         }
  83
  84                 }
  85                 /* If sent_parsed is impossibly high, drop it down.
  86                  * This is useful if the configuration is changed.
  87                  */
  88                 if(client_p->localClient->sent_parsed > allow_read)
  89                         client_p->localClient->sent_parsed = allow_read;
  90         }
  91
  92         if(IsAnyServer(client_p) || IsExemptFlood(client_p))
  93         {
  94                 while (!IsAnyDead(client_p) && (dolen = rb_linebuf_get(&client_p->localClient->buf_recvq,
  95                                            readBuf, READBUF_SIZE, LINEBUF_COMPLETE,
  96                                            LINEBUF_PARSED)) > 0)
  97                 {
  98                         client_dopacket(client_p, readBuf, dolen);
  99                 }
 100         }
 101         else if(IsClient(client_p))
 102         {
 103                 if(IsFloodDone(client_p))
 104                         allow_read = ConfigFileEntry.client_flood_burst_max;
 105                 else
 106                         allow_read = ConfigFileEntry.client_flood_burst_rate;
 107                 allow_read *= ConfigFileEntry.client_flood_message_time;
 108                 /* allow opers 4 times the amount of messages as users. why 4?
 109                  * why not. :) --fl_
 110                  */
 111                 if(IsOper(client_p) && ConfigFileEntry.no_oper_flood)
 112                         allow_read *= 4;
 113                 /*
 114                  * Handle flood protection here - if we exceed our flood limit on
 115                  * messages in this loop, we simply drop out of the loop prematurely.
 116                  *   -- adrian
 117                  */
 118                 for (;;)
 119                 {
 120                         /* This flood protection works as follows:
 121                          *
 122                          * A client is given allow_read lines to send to the server.  Every
 123                          * time a line is parsed, sent_parsed is increased.  sent_parsed
 124                          * is decreased by 1 every time flood_recalc is called.
 125                          *
 126                          * Thus a client can 'burst' allow_read lines to the server, any
 127                          * excess lines will be parsed one per flood_recalc() call.
 128                          *
 129                          * Therefore a client will be penalised more if they keep flooding,
 130                          * as sent_parsed will always hover around the allow_read limit
 131                          * and no 'bursts' will be permitted.
 132                          */
 133                         if(client_p->localClient->sent_parsed >= allow_read)
 134                                 break;
 135
 136                         dolen = rb_linebuf_get(&client_p->localClient->
 137                                             buf_recvq, readBuf, READBUF_SIZE,
 138                                             LINEBUF_COMPLETE, LINEBUF_PARSED);
 139
 140                         if(!dolen)
 141                                 break;
 142
 143                         client_dopacket(client_p, readBuf, dolen);
 144                         if(IsAnyDead(client_p))
 145                                 return;
 146
 147                         client_p->localClient->sent_parsed += ConfigFileEntry.client_flood_message_time;
 148                 }
 149                 /* If sent_parsed is impossibly high, drop it down.
 150                  * This is useful if the configuration is changed.
 151                  */
 152                 if(client_p->localClient->sent_parsed > allow_read +
 153                                 ConfigFileEntry.client_flood_message_time - 1)
 154                         client_p->localClient->sent_parsed = allow_read +
 155                                 ConfigFileEntry.client_flood_message_time - 1;
 156         }
 157 }
 158
 159 /* flood_endgrace()
 160  *
 161  * marks the end of the clients grace period
 162  */
 163 void
 164 flood_endgrace(struct Client *client_p)
 165 {
 166         SetFloodDone(client_p);
 167
 168         /* sent_parsed could be way over client_flood_burst_max but under
 169          * client_flood_burst_rate so reset it.
 170          */
 171         client_p->localClient->sent_parsed = 0;
 172 }
 173
 174 /*
 175  * flood_recalc
 176  *
 177  * recalculate the number of allowed flood lines. this should be called
 178  * once a second on any given client. We then attempt to flush some data.
 179  */
 180 void
 181 flood_recalc(void *unused)
 182 {
 183         rb_dlink_node *ptr, *next;
 184         struct Client *client_p;
 185
 186         RB_DLINK_FOREACH_SAFE(ptr, next, lclient_list.head)
 187         {
 188                 client_p = ptr->data;
 189
 190                 if(rb_unlikely(IsMe(client_p)))
 191                         continue;
 192
 193                 if(rb_unlikely(client_p->localClient == NULL))
 194                         continue;
 195
 196                 if(IsFloodDone(client_p))
 197                         client_p->localClient->sent_parsed -= ConfigFileEntry.client_flood_message_num;
 198                 else
 199                         client_p->localClient->sent_parsed = 0;
 200
 201                 if(client_p->localClient->sent_parsed < 0)
 202                         client_p->localClient->sent_parsed = 0;
 203
 204                 parse_client_queued(client_p);
 205
 206                 if(rb_unlikely(IsAnyDead(client_p)))
 207                         continue;
 208
 209         }
 210
 211         RB_DLINK_FOREACH_SAFE(ptr, next, unknown_list.head)
 212         {
 213                 client_p = ptr->data;
 214
 215                 if(client_p->localClient == NULL)
 216                         continue;
 217
 218                 client_p->localClient->sent_parsed--;
 219
 220                 if(client_p->localClient->sent_parsed < 0)
 221                         client_p->localClient->sent_parsed = 0;
 222
 223                 parse_client_queued(client_p);
 224         }
 225 }
 226
 227 /*
 228  * read_packet - Read a 'packet' of data from a connection and process it.
 229  */
 230 void
 231 read_packet(rb_fde_t * F, void *data)
 232 {
 233         struct Client *client_p = data;
 234         int length = 0;
 235         int binary = 0;
 236
 237         while(1)
 238         {
 239                 if(IsAnyDead(client_p))
 240                         return;
 241
 242                 /*
 243                  * Read some data. We *used to* do anti-flood protection here, but
 244                  * I personally think it makes the code too hairy to make sane.
 245                  *     -- adrian
 246                  */
 247                 length = rb_read(client_p->localClient->F, readBuf, READBUF_SIZE);
 248
 249                 if(length < 0)
 250                 {
 251                         if(rb_ignore_errno(errno))
 252                                 rb_setselect(client_p->localClient->F,
 253                                                 RB_SELECT_READ, read_packet, client_p);
 254                         else
 255                                 error_exit_client(client_p, length);
 256                         return;
 257                 }
 258                 else if(length == 0)
 259                 {
 260                         error_exit_client(client_p, length);
 261                         return;
 262                 }
 263
 264                 if(client_p->localClient->lasttime < rb_current_time())
 265                         client_p->localClient->lasttime = rb_current_time();
 266                 client_p->flags &= ~FLAGS_PINGSENT;
 267
 268                 /*
 269                  * Before we even think of parsing what we just read, stick
 270                  * it on the end of the receive queue and do it when its
 271                  * turn comes around.
 272                  */
 273                 if(IsHandshake(client_p) || IsUnknown(client_p))
 274                         binary = 1;
 275
 276                 (void) rb_linebuf_parse(&client_p->localClient->buf_recvq, readBuf, length, binary);
 277
 278                 if(IsAnyDead(client_p))
 279                         return;
 280
 281                 /* Attempt to parse what we have */
 282                 parse_client_queued(client_p);
 283
 284                 if(IsAnyDead(client_p))
 285                         return;
 286
 287                 /* Check to make sure we're not flooding */
 288                 if(!IsAnyServer(client_p) &&
 289                    (rb_linebuf_alloclen(&client_p->localClient->buf_recvq) > ConfigFileEntry.client_flood_max_lines))
 290                 {
 291                         if(!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
 292                         {
 293                                 exit_client(client_p, client_p, client_p, "Excess Flood");
 294                                 return;
 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
 340         if(client_p->localClient->receiveB > 1023)
 341         {
 342                 client_p->localClient->receiveK += (client_p->localClient->receiveB >> 10);
 343                 client_p->localClient->receiveB &= 0x03ff;      /* 2^10 = 1024, 3ff = 1023 */
 344         }
 345
 346         me.localClient->receiveB += length;
 347
 348         if(me.localClient->receiveB > 1023)
 349         {
 350                 me.localClient->receiveK += (me.localClient->receiveB >> 10);
 351                 me.localClient->receiveB &= 0x03ff;
 352         }
 353
 354         parse(client_p, buffer, buffer + length);
 355 }