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

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Revision 34 - (hide annotations)
Sun Oct 2 21:05:51 2005 UTC (14 years, 9 months ago) by lusky
File MIME type: text/x-chdr
File size: 13511 byte(s)
create 7.2 branch, we can move/rename it as needed.


1 adx 30 /*
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 knight 31 * $Id$
23 adx 30 */
24     #include "stdinc.h"
25     #include "tools.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 "list.h"
33     #include "parse.h"
34     #include "fdlist.h"
35     #include "packet.h"
36     #include "irc_string.h"
37     #include "memory.h"
38     #include "hook.h"
39     #include "send.h"
40     #include "irc_getnameinfo.h"
41    
42     #define READBUF_SIZE 16384
43    
44     struct Callback *iorecv_cb = NULL;
45     struct Callback *iorecvctrl_cb = NULL;
46    
47     static char readBuf[READBUF_SIZE];
48     static void client_dopacket(struct Client *, char *, size_t);
49    
50     /* extract_one_line()
51     *
52     * inputs - pointer to a dbuf queue
53     * - pointer to buffer to copy data to
54     * output - length of <buffer>
55     * side effects - one line is copied and removed from the dbuf
56     */
57     static int
58     extract_one_line(struct dbuf_queue *qptr, char *buffer)
59     {
60     struct dbuf_block *block;
61     int line_bytes = 0, empty_bytes = 0, phase = 0;
62     unsigned int idx;
63    
64     char c;
65     dlink_node *ptr;
66    
67     /*
68     * Phase 0: "empty" characters before the line
69     * Phase 1: copying the line
70     * Phase 2: "empty" characters after the line
71     * (delete them as well and free some space in the dbuf)
72     *
73     * Empty characters are CR, LF and space (but, of course, not
74     * in the middle of a line). We try to remove as much of them as we can,
75     * since they simply eat server memory.
76     *
77     * --adx
78     */
79     DLINK_FOREACH(ptr, qptr->blocks.head)
80     {
81     block = ptr->data;
82    
83     for (idx = 0; idx < block->size; idx++)
84     {
85     c = block->data[idx];
86     if (IsEol(c) || (c == ' ' && phase != 1))
87     {
88     empty_bytes++;
89     if (phase == 1)
90     phase = 2;
91     }
92     else switch (phase)
93     {
94     case 0: phase = 1;
95     case 1: if (line_bytes++ < IRCD_BUFSIZE - 2)
96     *buffer++ = c;
97     break;
98     case 2: *buffer = '\0';
99     dbuf_delete(qptr, line_bytes + empty_bytes);
100     return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
101     }
102     }
103     }
104    
105     /*
106     * Now, if we haven't reached phase 2, ignore all line bytes
107     * that we have read, since this is a partial line case.
108     */
109     if (phase != 2)
110     line_bytes = 0;
111     else
112     *buffer = '\0';
113    
114     /* Remove what is now unnecessary */
115     dbuf_delete(qptr, line_bytes + empty_bytes);
116     return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
117     }
118    
119     /*
120     * parse_client_queued - parse client queued messages
121     */
122     static void
123     parse_client_queued(struct Client *client_p)
124     {
125     int dolen = 0;
126     int checkflood = 1;
127     struct LocalUser *lclient_p = client_p->localClient;
128    
129     if (IsUnknown(client_p))
130     {
131     int i = 0;
132    
133     for(;;)
134     {
135     if (IsDefunct(client_p))
136     return;
137    
138     /* rate unknown clients at MAX_FLOOD per loop */
139     if (i >= MAX_FLOOD)
140     break;
141    
142     dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
143     if (dolen == 0)
144     break;
145    
146     client_dopacket(client_p, readBuf, dolen);
147     i++;
148    
149     /* if they've dropped out of the unknown state, break and move
150     * to the parsing for their appropriate status. --fl
151     */
152     if(!IsUnknown(client_p))
153     break;
154     }
155     }
156    
157     if (IsServer(client_p) || IsConnecting(client_p) || IsHandshake(client_p))
158     {
159     while (1)
160     {
161     if (IsDefunct(client_p))
162     return;
163     if ((dolen = extract_one_line(&lclient_p->buf_recvq,
164     readBuf)) == 0)
165     break;
166     client_dopacket(client_p, readBuf, dolen);
167     }
168     }
169     else if(IsClient(client_p))
170     {
171     if (ConfigFileEntry.no_oper_flood && (IsOper(client_p) || IsCanFlood(client_p)))
172     {
173     if (ConfigFileEntry.true_no_oper_flood)
174     checkflood = -1;
175     else
176     checkflood = 0;
177     }
178    
179     /*
180     * Handle flood protection here - if we exceed our flood limit on
181     * messages in this loop, we simply drop out of the loop prematurely.
182     * -- adrian
183     */
184     for (;;)
185     {
186     if (IsDefunct(client_p))
187     break;
188    
189     /* This flood protection works as follows:
190     *
191     * A client is given allow_read lines to send to the server. Every
192     * time a line is parsed, sent_parsed is increased. sent_parsed
193     * is decreased by 1 every time flood_recalc is called.
194     *
195     * Thus a client can 'burst' allow_read lines to the server, any
196     * excess lines will be parsed one per flood_recalc() call.
197     *
198     * Therefore a client will be penalised more if they keep flooding,
199     * as sent_parsed will always hover around the allow_read limit
200     * and no 'bursts' will be permitted.
201     */
202     if (checkflood > 0)
203     {
204     if(lclient_p->sent_parsed >= lclient_p->allow_read)
205     break;
206     }
207    
208     /* allow opers 4 times the amount of messages as users. why 4?
209     * why not. :) --fl_
210     */
211     else if (lclient_p->sent_parsed >= (4 * lclient_p->allow_read) &&
212     checkflood != -1)
213     break;
214    
215     dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
216     if (dolen == 0)
217     break;
218    
219     client_dopacket(client_p, readBuf, dolen);
220     lclient_p->sent_parsed++;
221     }
222     }
223     }
224    
225     /* flood_endgrace()
226     *
227     * marks the end of the clients grace period
228     */
229     void
230     flood_endgrace(struct Client *client_p)
231     {
232     SetFloodDone(client_p);
233    
234     /* Drop their flood limit back down */
235     client_p->localClient->allow_read = MAX_FLOOD;
236    
237     /* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
238     * so reset it.
239     */
240     client_p->localClient->sent_parsed = 0;
241     }
242    
243     /*
244     * flood_recalc
245     *
246     * recalculate the number of allowed flood lines. this should be called
247     * once a second on any given client. We then attempt to flush some data.
248     */
249     void
250     flood_recalc(fde_t *fd, void *data)
251     {
252     struct Client *client_p = data;
253     struct LocalUser *lclient_p = client_p->localClient;
254    
255     /* allow a bursting client their allocation per second, allow
256     * a client whos flooding an extra 2 per second
257     */
258     if (IsFloodDone(client_p))
259     lclient_p->sent_parsed -= 2;
260     else
261     lclient_p->sent_parsed = 0;
262    
263     if (lclient_p->sent_parsed < 0)
264     lclient_p->sent_parsed = 0;
265    
266     parse_client_queued(client_p);
267    
268     /* And now, try flushing .. */
269     if (!IsDead(client_p))
270     {
271     /* and finally, reset the flood check */
272     comm_setflush(fd, 1000, flood_recalc, client_p);
273     }
274     }
275    
276     /*
277     * read_ctrl_packet - Read a 'packet' of data from a servlink control
278     * link and process it.
279     */
280     void
281     read_ctrl_packet(fde_t *fd, void *data)
282     {
283     struct Client *server = data;
284     struct LocalUser *lserver = server->localClient;
285     struct SlinkRpl *reply;
286     int length = 0;
287     unsigned char tmp[2];
288     unsigned char *len = tmp;
289     struct SlinkRplDef *replydef;
290    
291     assert(lserver != NULL);
292    
293     reply = &lserver->slinkrpl;
294    
295     if (IsDefunct(server))
296     return;
297    
298     if (!reply->command)
299     {
300     reply->gotdatalen = 0;
301     reply->readdata = 0;
302     reply->data = NULL;
303    
304     length = recv(fd->fd, tmp, 1, 0);
305    
306     if (length <= 0)
307     {
308     if ((length == -1) && ignoreErrno(errno))
309     goto nodata;
310     dead_link_on_read(server, length);
311     return;
312     }
313     reply->command = tmp[0];
314     }
315    
316     for (replydef = slinkrpltab; replydef->handler; replydef++)
317     {
318     if (replydef->replyid == (unsigned int)reply->command)
319     break;
320     }
321    
322     /* we should be able to trust a local slink process...
323     * and if it sends an invalid command, that's a bug.. */
324     assert(replydef->handler);
325    
326     if ((replydef->flags & SLINKRPL_FLAG_DATA) && (reply->gotdatalen < 2))
327     {
328     /* we need a datalen u16 which we don't have yet... */
329     length = recv(fd->fd, len, (2 - reply->gotdatalen), 0);
330     if (length <= 0)
331     {
332     if ((length == -1) && ignoreErrno(errno))
333     goto nodata;
334     dead_link_on_read(server, length);
335     return;
336     }
337    
338     if (reply->gotdatalen == 0)
339     {
340     reply->datalen = *len << 8;
341     reply->gotdatalen++;
342     length--;
343     len++;
344     }
345     if (length && (reply->gotdatalen == 1))
346     {
347     reply->datalen |= *len;
348     reply->gotdatalen++;
349     if (reply->datalen > 0)
350     reply->data = MyMalloc(reply->datalen);
351     }
352    
353     if (reply->gotdatalen < 2)
354     return; /* wait for more data */
355     }
356    
357     if (reply->readdata < reply->datalen) /* try to get any remaining data */
358     {
359     length = recv(fd->fd, (reply->data + reply->readdata),
360     (reply->datalen - reply->readdata), 0);
361     if (length <= 0)
362     {
363     if ((length == -1) && ignoreErrno(errno))
364     goto nodata;
365     dead_link_on_read(server, length);
366     return;
367     }
368    
369     reply->readdata += length;
370     if (reply->readdata < reply->datalen)
371     return; /* wait for more data */
372     }
373    
374     execute_callback(iorecvctrl_cb, server, reply->command);
375    
376     /* we now have the command and any data, pass it off to the handler */
377     (*replydef->handler)(reply->command, reply->datalen, reply->data, server);
378    
379     /* reset SlinkRpl */
380     if (reply->datalen > 0)
381     MyFree(reply->data);
382     reply->command = 0;
383    
384     if (IsDead(server))
385     return;
386    
387     nodata:
388     /* If we get here, we need to register for another COMM_SELECT_READ */
389     comm_setselect(fd, COMM_SELECT_READ, read_ctrl_packet, server, 0);
390     }
391    
392     /*
393     * read_packet - Read a 'packet' of data from a connection and process it.
394     */
395     void
396     read_packet(fde_t *fd, void *data)
397     {
398     struct Client *client_p = data;
399     int length = 0;
400    
401     if (IsDefunct(client_p))
402     return;
403    
404     /*
405     * Read some data. We *used to* do anti-flood protection here, but
406     * I personally think it makes the code too hairy to make sane.
407     * -- adrian
408     */
409     do {
410     #ifdef HAVE_LIBCRYPTO
411     if (fd->ssl)
412     {
413     length = SSL_read(fd->ssl, readBuf, READBUF_SIZE);
414    
415     /* translate openssl error codes, sigh */
416     if (length < 0)
417     switch (SSL_get_error(fd->ssl, length))
418     {
419     case SSL_ERROR_WANT_WRITE:
420     fd->flags.pending_read = 1;
421     SetSendqBlocked(client_p);
422     comm_setselect(fd, COMM_SELECT_WRITE, (PF *) sendq_unblocked,
423     client_p, 0);
424     return;
425     case SSL_ERROR_WANT_READ:
426     errno = EWOULDBLOCK;
427     case SSL_ERROR_SYSCALL:
428     break;
429     default:
430     length = errno = 0;
431     }
432     }
433     else
434     #endif
435     {
436     length = recv(fd->fd, readBuf, READBUF_SIZE, 0);
437     #ifdef _WIN32
438     if (length < 0)
439     errno = WSAGetLastError();
440     #endif
441     }
442    
443     if (length <= 0)
444     {
445     /*
446     * If true, then we can recover from this error. Just jump out of
447     * the loop and re-register a new io-request.
448     */
449     if (length < 0 && ignoreErrno(errno))
450     break;
451    
452     dead_link_on_read(client_p, length);
453     return;
454     }
455    
456     execute_callback(iorecv_cb, client_p, length, readBuf);
457    
458     if (client_p->lasttime < CurrentTime)
459     client_p->lasttime = CurrentTime;
460     if (client_p->lasttime > client_p->since)
461     client_p->since = CurrentTime;
462     ClearPingSent(client_p);
463    
464     dbuf_put(&client_p->localClient->buf_recvq, readBuf, length);
465    
466     /* Attempt to parse what we have */
467     parse_client_queued(client_p);
468    
469     if (IsDefunct(client_p))
470     return;
471    
472     /* Check to make sure we're not flooding */
473     /* TBD - ConfigFileEntry.client_flood should be a size_t */
474     if (!(IsServer(client_p) || IsHandshake(client_p) || IsConnecting(client_p))
475     && (dbuf_length(&client_p->localClient->buf_recvq) >
476     (unsigned int)ConfigFileEntry.client_flood))
477     {
478     if (!(ConfigFileEntry.no_oper_flood && IsOper(client_p)))
479     {
480     exit_client(client_p, client_p, "Excess Flood");
481     return;
482     }
483     }
484     }
485     #ifdef HAVE_LIBCRYPTO
486     while (length == sizeof(readBuf) || fd->ssl);
487     #else
488     while (length == sizeof(readBuf));
489     #endif
490    
491     /* If we get here, we need to register for another COMM_SELECT_READ */
492     comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
493     }
494    
495     /*
496     * client_dopacket - copy packet to client buf and parse it
497     * client_p - pointer to client structure for which the buffer data
498     * applies.
499     * buffer - pointr to the buffer containing the newly read data
500     * length - number of valid bytes of data in the buffer
501     *
502     * Note:
503     * It is implicitly assumed that dopacket is called only
504     * with client_p of "local" variation, which contains all the
505     * necessary fields (buffer etc..)
506     */
507     static void
508     client_dopacket(struct Client *client_p, char *buffer, size_t length)
509     {
510     /*
511     * Update messages received
512     */
513     ++me.localClient->recv.messages;
514     ++client_p->localClient->recv.messages;
515    
516     /*
517     * Update bytes received
518     */
519     client_p->localClient->recv.bytes += length;
520     me.localClient->recv.bytes += length;
521    
522     parse(client_p, buffer, buffer + length);
523     }

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