/[svn]/ircd-hybrid-7.2/src/packet.c
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Contents of /ircd-hybrid-7.2/src/packet.c

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Revision 1011 - (show annotations)
Fri Sep 18 10:14:09 2009 UTC (10 years, 1 month ago) by michael
File MIME type: text/x-chdr
File size: 13739 byte(s)
- move list manipulation routines from tools.c to list.c
- mem_frob() goes to memory.c
- sort out redundant/unneeded header includes

1 /*
2 * ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
3 * packet.c: Packet handlers.
4 *
5 * Copyright (C) 2002 by the past and present ircd coders, and others.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
20 * USA
21 *
22 * $Id$
23 */
24 #include "stdinc.h"
25 #include "list.h"
26 #include "s_bsd.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 "fdlist.h"
34 #include "packet.h"
35 #include "irc_string.h"
36 #include "memory.h"
37 #include "hook.h"
38 #include "send.h"
39 #include "irc_getnameinfo.h"
40
41 #define READBUF_SIZE 16384
42
43 struct Callback *iorecv_cb = NULL;
44 struct Callback *iorecvctrl_cb = NULL;
45
46 static char readBuf[READBUF_SIZE];
47 static void client_dopacket(struct Client *, char *, size_t);
48
49 /* extract_one_line()
50 *
51 * inputs - pointer to a dbuf queue
52 * - pointer to buffer to copy data to
53 * output - length of <buffer>
54 * side effects - one line is copied and removed from the dbuf
55 */
56 static int
57 extract_one_line(struct dbuf_queue *qptr, char *buffer)
58 {
59 struct dbuf_block *block;
60 int line_bytes = 0, empty_bytes = 0, phase = 0;
61 unsigned int idx;
62
63 char c;
64 dlink_node *ptr;
65
66 /*
67 * Phase 0: "empty" characters before the line
68 * Phase 1: copying the line
69 * Phase 2: "empty" characters after the line
70 * (delete them as well and free some space in the dbuf)
71 *
72 * Empty characters are CR, LF and space (but, of course, not
73 * in the middle of a line). We try to remove as much of them as we can,
74 * since they simply eat server memory.
75 *
76 * --adx
77 */
78 DLINK_FOREACH(ptr, qptr->blocks.head)
79 {
80 block = ptr->data;
81
82 for (idx = 0; idx < block->size; idx++)
83 {
84 c = block->data[idx];
85 if (IsEol(c) || (c == ' ' && phase != 1))
86 {
87 empty_bytes++;
88 if (phase == 1)
89 phase = 2;
90 }
91 else switch (phase)
92 {
93 case 0: phase = 1;
94 case 1: if (line_bytes++ < IRCD_BUFSIZE - 2)
95 *buffer++ = c;
96 break;
97 case 2: *buffer = '\0';
98 dbuf_delete(qptr, line_bytes + empty_bytes);
99 return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
100 }
101 }
102 }
103
104 /*
105 * Now, if we haven't reached phase 2, ignore all line bytes
106 * that we have read, since this is a partial line case.
107 */
108 if (phase != 2)
109 line_bytes = 0;
110 else
111 *buffer = '\0';
112
113 /* Remove what is now unnecessary */
114 dbuf_delete(qptr, line_bytes + empty_bytes);
115 return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
116 }
117
118 /*
119 * parse_client_queued - parse client queued messages
120 */
121 static void
122 parse_client_queued(struct Client *client_p)
123 {
124 int dolen = 0;
125 int checkflood = 1;
126 struct LocalUser *lclient_p = client_p->localClient;
127
128 if (IsUnknown(client_p))
129 {
130 int i = 0;
131
132 for(;;)
133 {
134 if (IsDefunct(client_p))
135 return;
136
137 /* rate unknown clients at MAX_FLOOD per loop */
138 if (i >= MAX_FLOOD)
139 break;
140
141 dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
142 if (dolen == 0)
143 break;
144
145 client_dopacket(client_p, readBuf, dolen);
146 i++;
147
148 /* if they've dropped out of the unknown state, break and move
149 * to the parsing for their appropriate status. --fl
150 */
151 if(!IsUnknown(client_p))
152 break;
153 }
154 }
155
156 if (IsServer(client_p) || IsConnecting(client_p) || IsHandshake(client_p))
157 {
158 while (1)
159 {
160 if (IsDefunct(client_p))
161 return;
162 if ((dolen = extract_one_line(&lclient_p->buf_recvq,
163 readBuf)) == 0)
164 break;
165 client_dopacket(client_p, readBuf, dolen);
166 }
167 }
168 else if (IsClient(client_p))
169 {
170 if (ConfigFileEntry.no_oper_flood && (IsOper(client_p) || IsCanFlood(client_p)))
171 {
172 if (ConfigFileEntry.true_no_oper_flood)
173 checkflood = -1;
174 else
175 checkflood = 0;
176 }
177
178 /*
179 * Handle flood protection here - if we exceed our flood limit on
180 * messages in this loop, we simply drop out of the loop prematurely.
181 * -- adrian
182 */
183 for (;;)
184 {
185 if (IsDefunct(client_p))
186 break;
187
188 /* This flood protection works as follows:
189 *
190 * A client is given allow_read lines to send to the server. Every
191 * time a line is parsed, sent_parsed is increased. sent_parsed
192 * is decreased by 1 every time flood_recalc is called.
193 *
194 * Thus a client can 'burst' allow_read lines to the server, any
195 * excess lines will be parsed one per flood_recalc() call.
196 *
197 * Therefore a client will be penalised more if they keep flooding,
198 * as sent_parsed will always hover around the allow_read limit
199 * and no 'bursts' will be permitted.
200 */
201 if (checkflood > 0)
202 {
203 if(lclient_p->sent_parsed >= lclient_p->allow_read)
204 break;
205 }
206
207 /* allow opers 4 times the amount of messages as users. why 4?
208 * why not. :) --fl_
209 */
210 else if (lclient_p->sent_parsed >= (4 * lclient_p->allow_read) &&
211 checkflood != -1)
212 break;
213
214 dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
215 if (dolen == 0)
216 break;
217
218 client_dopacket(client_p, readBuf, dolen);
219 lclient_p->sent_parsed++;
220 }
221 }
222 }
223
224 /* flood_endgrace()
225 *
226 * marks the end of the clients grace period
227 */
228 void
229 flood_endgrace(struct Client *client_p)
230 {
231 SetFloodDone(client_p);
232
233 /* Drop their flood limit back down */
234 client_p->localClient->allow_read = MAX_FLOOD;
235
236 /* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
237 * so reset it.
238 */
239 client_p->localClient->sent_parsed = 0;
240 }
241
242 /*
243 * flood_recalc
244 *
245 * recalculate the number of allowed flood lines. this should be called
246 * once a second on any given client. We then attempt to flush some data.
247 */
248 void
249 flood_recalc(fde_t *fd, void *data)
250 {
251 struct Client *client_p = data;
252 struct LocalUser *lclient_p = client_p->localClient;
253
254 /* allow a bursting client their allocation per second, allow
255 * a client whos flooding an extra 2 per second
256 */
257 if (IsFloodDone(client_p))
258 lclient_p->sent_parsed -= 2;
259 else
260 lclient_p->sent_parsed = 0;
261
262 if (lclient_p->sent_parsed < 0)
263 lclient_p->sent_parsed = 0;
264
265 parse_client_queued(client_p);
266
267 /* And now, try flushing .. */
268 if (!IsDead(client_p))
269 {
270 /* and finally, reset the flood check */
271 comm_setflush(fd, 1000, flood_recalc, client_p);
272 }
273 }
274
275 /*
276 * read_ctrl_packet - Read a 'packet' of data from a servlink control
277 * link and process it.
278 */
279 void
280 read_ctrl_packet(fde_t *fd, void *data)
281 {
282 struct Client *server = data;
283 struct LocalUser *lserver = server->localClient;
284 struct SlinkRpl *reply;
285 int length = 0;
286 unsigned char tmp[2];
287 unsigned char *len = tmp;
288 struct SlinkRplDef *replydef;
289
290 assert(lserver != NULL);
291
292 reply = &lserver->slinkrpl;
293
294 if (IsDefunct(server))
295 return;
296
297 if (!reply->command)
298 {
299 reply->gotdatalen = 0;
300 reply->readdata = 0;
301 reply->data = NULL;
302
303 length = recv(fd->fd, tmp, 1, 0);
304
305 if (length <= 0)
306 {
307 if ((length == -1) && ignoreErrno(errno))
308 goto nodata;
309 dead_link_on_read(server, length);
310 return;
311 }
312 reply->command = tmp[0];
313 }
314
315 for (replydef = slinkrpltab; replydef->handler; replydef++)
316 {
317 if (replydef->replyid == (unsigned int)reply->command)
318 break;
319 }
320
321 /* we should be able to trust a local slink process...
322 * and if it sends an invalid command, that's a bug.. */
323 assert(replydef->handler);
324
325 if ((replydef->flags & SLINKRPL_FLAG_DATA) && (reply->gotdatalen < 2))
326 {
327 /* we need a datalen u16 which we don't have yet... */
328 length = recv(fd->fd, len, (2 - reply->gotdatalen), 0);
329 if (length <= 0)
330 {
331 if ((length == -1) && ignoreErrno(errno))
332 goto nodata;
333 dead_link_on_read(server, length);
334 return;
335 }
336
337 if (reply->gotdatalen == 0)
338 {
339 reply->datalen = *len << 8;
340 reply->gotdatalen++;
341 length--;
342 len++;
343 }
344 if (length && (reply->gotdatalen == 1))
345 {
346 reply->datalen |= *len;
347 reply->gotdatalen++;
348 if (reply->datalen > 0)
349 reply->data = MyMalloc(reply->datalen);
350 }
351
352 if (reply->gotdatalen < 2)
353 return; /* wait for more data */
354 }
355
356 if (reply->readdata < reply->datalen) /* try to get any remaining data */
357 {
358 length = recv(fd->fd, (reply->data + reply->readdata),
359 (reply->datalen - reply->readdata), 0);
360 if (length <= 0)
361 {
362 if ((length == -1) && ignoreErrno(errno))
363 goto nodata;
364 dead_link_on_read(server, length);
365 return;
366 }
367
368 reply->readdata += length;
369 if (reply->readdata < reply->datalen)
370 return; /* wait for more data */
371 }
372
373 execute_callback(iorecvctrl_cb, server, reply->command);
374
375 /* we now have the command and any data, pass it off to the handler */
376 (*replydef->handler)(reply->command, reply->datalen, reply->data, server);
377
378 /* reset SlinkRpl */
379 if (reply->datalen > 0)
380 MyFree(reply->data);
381 reply->command = 0;
382
383 if (IsDead(server))
384 return;
385
386 nodata:
387 /* If we get here, we need to register for another COMM_SELECT_READ */
388 comm_setselect(fd, COMM_SELECT_READ, read_ctrl_packet, server, 0);
389 }
390
391 /*
392 * iorecv_default - append a packet to the recvq dbuf
393 */
394 void *
395 iorecv_default(va_list args)
396 {
397 struct Client *client_p = va_arg(args, struct Client *);
398 int length = va_arg(args, int);
399 char *buf = va_arg(args, char *);
400
401 dbuf_put(&client_p->localClient->buf_recvq, buf, length);
402 return NULL;
403 }
404
405 /*
406 * read_packet - Read a 'packet' of data from a connection and process it.
407 */
408 void
409 read_packet(fde_t *fd, void *data)
410 {
411 struct Client *client_p = data;
412 int length = 0;
413
414 if (IsDefunct(client_p))
415 return;
416
417 /*
418 * Read some data. We *used to* do anti-flood protection here, but
419 * I personally think it makes the code too hairy to make sane.
420 * -- adrian
421 */
422 do {
423 #ifdef HAVE_LIBCRYPTO
424 if (fd->ssl)
425 {
426 length = SSL_read(fd->ssl, readBuf, READBUF_SIZE);
427
428 /* translate openssl error codes, sigh */
429 if (length < 0)
430 switch (SSL_get_error(fd->ssl, length))
431 {
432 case SSL_ERROR_WANT_WRITE:
433 fd->flags.pending_read = 1;
434 SetSendqBlocked(client_p);
435 comm_setselect(fd, COMM_SELECT_WRITE, (PF *) sendq_unblocked,
436 client_p, 0);
437 return;
438 case SSL_ERROR_WANT_READ:
439 errno = EWOULDBLOCK;
440 case SSL_ERROR_SYSCALL:
441 break;
442 case SSL_ERROR_SSL:
443 if (errno == EAGAIN)
444 break;
445 default:
446 length = errno = 0;
447 }
448 }
449 else
450 #endif
451 {
452 length = recv(fd->fd, readBuf, READBUF_SIZE, 0);
453 }
454
455 if (length <= 0)
456 {
457 /*
458 * If true, then we can recover from this error. Just jump out of
459 * the loop and re-register a new io-request.
460 */
461 if (length < 0 && ignoreErrno(errno))
462 break;
463
464 dead_link_on_read(client_p, length);
465 return;
466 }
467
468 execute_callback(iorecv_cb, client_p, length, readBuf);
469
470 if (client_p->lasttime < CurrentTime)
471 client_p->lasttime = CurrentTime;
472 if (client_p->lasttime > client_p->since)
473 client_p->since = CurrentTime;
474 ClearPingSent(client_p);
475
476 /* Attempt to parse what we have */
477 parse_client_queued(client_p);
478
479 if (IsDefunct(client_p))
480 return;
481
482 /* Check to make sure we're not flooding */
483 /* TBD - ConfigFileEntry.client_flood should be a size_t */
484 if (!(IsServer(client_p) || IsHandshake(client_p) || IsConnecting(client_p))
485 && (dbuf_length(&client_p->localClient->buf_recvq) >
486 (unsigned int)ConfigFileEntry.client_flood))
487 {
488 if (!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
489 {
490 exit_client(client_p, client_p, "Excess Flood");
491 return;
492 }
493 }
494 }
495 #ifdef HAVE_LIBCRYPTO
496 while (length == sizeof(readBuf) || fd->ssl);
497 #else
498 while (length == sizeof(readBuf));
499 #endif
500
501 /* If we get here, we need to register for another COMM_SELECT_READ */
502 comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
503 }
504
505 /*
506 * client_dopacket - copy packet to client buf and parse it
507 * client_p - pointer to client structure for which the buffer data
508 * applies.
509 * buffer - pointr to the buffer containing the newly read data
510 * length - number of valid bytes of data in the buffer
511 *
512 * Note:
513 * It is implicitly assumed that dopacket is called only
514 * with client_p of "local" variation, which contains all the
515 * necessary fields (buffer etc..)
516 */
517 static void
518 client_dopacket(struct Client *client_p, char *buffer, size_t length)
519 {
520 /*
521 * Update messages received
522 */
523 ++me.localClient->recv.messages;
524 ++client_p->localClient->recv.messages;
525
526 /*
527 * Update bytes received
528 */
529 client_p->localClient->recv.bytes += length;
530 me.localClient->recv.bytes += length;
531
532 parse(client_p, buffer, buffer + length);
533 }

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