8.2.x/src/packet.c

/*
 *  ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
 *  packet.c: Packet handlers.
 *
 *  Copyright (C) 2002 by the past and present ircd coders, and others.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 *
 *  $Id$
 */
#include "stdinc.h"
#include "list.h"
#include "s_bsd.h"
#include "conf.h"
#include "s_serv.h"
#include "client.h"
#include "ircd.h"
#include "parse.h"
#include "fdlist.h"
#include "packet.h"
#include "irc_string.h"
#include "memory.h"
#include "hook.h"
#include "send.h"
#include "s_misc.h"

#define READBUF_SIZE 16384

struct Callback *iorecv_cb = NULL;

static char readBuf[READBUF_SIZE];
static void client_dopacket(struct Client *, char *, size_t);

/* extract_one_line()
 *
 * inputs       - pointer to a dbuf queue
 *              - pointer to buffer to copy data to
 * output       - length of <buffer>
 * side effects - one line is copied and removed from the dbuf
 */
static int
extract_one_line(struct dbuf_queue *qptr, char *buffer)
{
  struct dbuf_block *block;
  int line_bytes = 0, empty_bytes = 0, phase = 0;
  unsigned int idx;

  char c;
  dlink_node *ptr;

  /*
   * Phase 0: "empty" characters before the line
   * Phase 1: copying the line
   * Phase 2: "empty" characters after the line
   *          (delete them as well and free some space in the dbuf)
   *
   * Empty characters are CR, LF and space (but, of course, not
   * in the middle of a line). We try to remove as much of them as we can,
   * since they simply eat server memory.
   *
   * --adx
   */
  DLINK_FOREACH(ptr, qptr->blocks.head)
  {
    block = ptr->data;

    for (idx = 0; idx < block->size; idx++)
    {
      c = block->data[idx];
      if (IsEol(c) || (c == ' ' && phase != 1))
      {
        empty_bytes++;
        if (phase == 1)
          phase = 2;
      }
      else switch (phase)
      {
        case 0: phase = 1;
        case 1: if (line_bytes++ < IRCD_BUFSIZE - 2)
                  *buffer++ = c;
                break;
        case 2: *buffer = '\0';
                dbuf_delete(qptr, line_bytes + empty_bytes);
                return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
      }
    }
  }

  /*
   * Now, if we haven't reached phase 2, ignore all line bytes
   * that we have read, since this is a partial line case.
   */
  if (phase != 2)
    line_bytes = 0;
  else
    *buffer = '\0';

  /* Remove what is now unnecessary */
  dbuf_delete(qptr, line_bytes + empty_bytes);
  return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
}

/*
 * parse_client_queued - parse client queued messages
 */
static void
parse_client_queued(struct Client *client_p)
{ 
  int dolen = 0;
  int checkflood = 1;
  struct LocalUser *lclient_p = client_p->localClient;

  if (IsUnknown(client_p))
  {
    int i = 0;

    for(;;)
    {
      if (IsDefunct(client_p))
        return;

      /* rate unknown clients at MAX_FLOOD per loop */
      if (i >= MAX_FLOOD)
        break;

      dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
      if (dolen == 0)
        break;

      client_dopacket(client_p, readBuf, dolen);
      i++;

      /* if they've dropped out of the unknown state, break and move
       * to the parsing for their appropriate status.  --fl
       */
      if(!IsUnknown(client_p))
        break;
    }
  }

  if (IsServer(client_p) || IsConnecting(client_p) || IsHandshake(client_p))
  {
    while (1)
    {
      if (IsDefunct(client_p))
        return;
      if ((dolen = extract_one_line(&lclient_p->buf_recvq,
                                    readBuf)) == 0)
        break;
      client_dopacket(client_p, readBuf, dolen);
    }
  }
  else if (IsClient(client_p))
  {
    if (ConfigFileEntry.no_oper_flood && (HasUMode(client_p, UMODE_OPER) || IsCanFlood(client_p)))
    {
      if (ConfigFileEntry.true_no_oper_flood)
        checkflood = -1;
      else
        checkflood = 0;
    }

    /*
     * Handle flood protection here - if we exceed our flood limit on
     * messages in this loop, we simply drop out of the loop prematurely.
     *   -- adrian
     */
    for (;;)
    {
      if (IsDefunct(client_p))
        break;

      /* This flood protection works as follows:
       *
       * A client is given allow_read lines to send to the server.  Every
       * time a line is parsed, sent_parsed is increased.  sent_parsed
       * is decreased by 1 every time flood_recalc is called.
       *
       * Thus a client can 'burst' allow_read lines to the server, any
       * excess lines will be parsed one per flood_recalc() call.
       *
       * Therefore a client will be penalised more if they keep flooding,
       * as sent_parsed will always hover around the allow_read limit
       * and no 'bursts' will be permitted.
       */
      if (checkflood > 0)
      {
        if(lclient_p->sent_parsed >= lclient_p->allow_read)
          break;
      }
      
      /* allow opers 4 times the amount of messages as users. why 4?
       * why not. :) --fl_
       */
      else if (lclient_p->sent_parsed >= (4 * lclient_p->allow_read) &&
               checkflood != -1)
        break;

      dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
      if (dolen == 0)
        break;

      client_dopacket(client_p, readBuf, dolen);
      lclient_p->sent_parsed++;
    }
  }
}

/* flood_endgrace()
 *
 * marks the end of the clients grace period
 */
void
flood_endgrace(struct Client *client_p)
{
  SetFloodDone(client_p);

  /* Drop their flood limit back down */
  client_p->localClient->allow_read = MAX_FLOOD;

  /* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
   * so reset it.
   */
  client_p->localClient->sent_parsed = 0;
}

/*
 * flood_recalc
 *
 * recalculate the number of allowed flood lines. this should be called
 * once a second on any given client. We then attempt to flush some data.
 */
void
flood_recalc(fde_t *fd, void *data)
{
  struct Client *client_p = data;
  struct LocalUser *lclient_p = client_p->localClient;
 
  /* allow a bursting client their allocation per second, allow
   * a client whos flooding an extra 2 per second
   */
  if (IsFloodDone(client_p))
    lclient_p->sent_parsed -= 2;
  else
    lclient_p->sent_parsed = 0;
  
  if (lclient_p->sent_parsed < 0)
    lclient_p->sent_parsed = 0;
  
  parse_client_queued(client_p);
  
  /* And now, try flushing .. */
  if (!IsDead(client_p))
  {
    /* and finally, reset the flood check */
    comm_setflush(fd, 1000, flood_recalc, client_p);
  }
}

/*
 * iorecv_default - append a packet to the recvq dbuf
 */
void *
iorecv_default(va_list args)
{
  struct Client *client_p = va_arg(args, struct Client *);
  int length = va_arg(args, int);
  char *buf = va_arg(args, char *);

  dbuf_put(&client_p->localClient->buf_recvq, buf, length);
  return NULL;
}

/*
 * read_packet - Read a 'packet' of data from a connection and process it.
 */
void
read_packet(fde_t *fd, void *data)
{
  struct Client *client_p = data;
  int length = 0;

  if (IsDefunct(client_p))
    return;

  /*
   * Read some data. We *used to* do anti-flood protection here, but
   * I personally think it makes the code too hairy to make sane.
   *     -- adrian
   */
  do {
#ifdef HAVE_LIBCRYPTO
    if (fd->ssl)
    {
      length = SSL_read(fd->ssl, readBuf, READBUF_SIZE);

      /* translate openssl error codes, sigh */
      if (length < 0)
        switch (SSL_get_error(fd->ssl, length))
        {
          case SSL_ERROR_WANT_WRITE:
            fd->flags.pending_read = 1;
            SetSendqBlocked(client_p);
            comm_setselect(fd, COMM_SELECT_WRITE, (PF *) sendq_unblocked,
                           client_p, 0);
            return;
          case SSL_ERROR_WANT_READ:
            errno = EWOULDBLOCK;
          case SSL_ERROR_SYSCALL:
            break;
          case SSL_ERROR_SSL:
            if (errno == EAGAIN)
              break;
          default:
            length = errno = 0;
        }
    }
    else
#endif
    {
      length = recv(fd->fd, readBuf, READBUF_SIZE, 0);
    }

    if (length <= 0)
    {
      /*
       * If true, then we can recover from this error.  Just jump out of
       * the loop and re-register a new io-request.
       */
      if (length < 0 && ignoreErrno(errno))
        break;

      dead_link_on_read(client_p, length);
      return;
    }

    execute_callback(iorecv_cb, client_p, length, readBuf);

    if (client_p->localClient->lasttime < CurrentTime)
      client_p->localClient->lasttime = CurrentTime;
    if (client_p->localClient->lasttime > client_p->localClient->since)
      client_p->localClient->since = CurrentTime;
    ClearPingSent(client_p);

    /* Attempt to parse what we have */
    parse_client_queued(client_p);

    if (IsDefunct(client_p))
      return;

    /* Check to make sure we're not flooding */
    if (!(IsServer(client_p) || IsHandshake(client_p) || IsConnecting(client_p))
        && (dbuf_length(&client_p->localClient->buf_recvq) >
            get_recvq(client_p)))
    {
      if (!(ConfigFileEntry.no_oper_flood && HasUMode(client_p, UMODE_OPER)))
      {
        exit_client(client_p, client_p, "Excess Flood");
        return;
      }
    }
  }
#ifdef HAVE_LIBCRYPTO
  while (length == sizeof(readBuf) || fd->ssl);
#else
  while (length == sizeof(readBuf));
#endif

  /* If we get here, we need to register for another COMM_SELECT_READ */
  comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
}

/*
 * client_dopacket - copy packet to client buf and parse it
 *      client_p - pointer to client structure for which the buffer data
 *             applies.
 *      buffer - pointr to the buffer containing the newly read data
 *      length - number of valid bytes of data in the buffer
 *
 * Note:
 *      It is implicitly assumed that dopacket is called only
 *      with client_p of "local" variation, which contains all the
 *      necessary fields (buffer etc..)
 */
static void
client_dopacket(struct Client *client_p, char *buffer, size_t length)
{
  /* 
   * Update messages received
   */
  ++me.localClient->recv.messages;
  ++client_p->localClient->recv.messages;

  /* 
   * Update bytes received
   */
  client_p->localClient->recv.bytes += length;
  me.localClient->recv.bytes += length;

  parse(client_p, buffer, buffer + length);
}
Revision:	1516
Committed:	Thu Aug 30 15:08:36 2012 UTC (11 years, 7 months ago) by michael
Content type:	text/x-csrc
Original Path:	*ircd-hybrid-8/src/packet.c*
File size:	10827 byte(s)
Log Message:	- Removed general::client_flood configuration option and added the new 'recvq' configuration directive to class{} blocks. The max size of a receive queue can be seen in "STATS Y" for each class - Update NEWS
#	User	Rev	Content
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	michael	1011	#include "list.h"
26	adx	30	#include "s_bsd.h"
27	michael	1309	#include "conf.h"
28	adx	30	#include "s_serv.h"
29			#include "client.h"
30			#include "ircd.h"
31			#include "parse.h"
32			#include "fdlist.h"
33			#include "packet.h"
34			#include "irc_string.h"
35			#include "memory.h"
36			#include "hook.h"
37			#include "send.h"
38	michael	1243	#include "s_misc.h"
39	adx	30
40			#define READBUF_SIZE 16384
41
42			struct Callback *iorecv_cb = NULL;
43
44			static char readBuf[READBUF_SIZE];
45			static void client_dopacket(struct Client , char , size_t);
46
47			/* extract_one_line()
48			*
49			* inputs - pointer to a dbuf queue
50			* - pointer to buffer to copy data to
51			* output - length of <buffer>
52			* side effects - one line is copied and removed from the dbuf
53			*/
54			static int
55			extract_one_line(struct dbuf_queue qptr, char buffer)
56			{
57			struct dbuf_block *block;
58			int line_bytes = 0, empty_bytes = 0, phase = 0;
59			unsigned int idx;
60
61			char c;
62			dlink_node *ptr;
63
64			/*
65			* Phase 0: "empty" characters before the line
66			* Phase 1: copying the line
67			* Phase 2: "empty" characters after the line
68			* (delete them as well and free some space in the dbuf)
69			*
70			* Empty characters are CR, LF and space (but, of course, not
71			* in the middle of a line). We try to remove as much of them as we can,
72			* since they simply eat server memory.
73			*
74			* --adx
75			*/
76			DLINK_FOREACH(ptr, qptr->blocks.head)
77			{
78			block = ptr->data;
79
80			for (idx = 0; idx < block->size; idx++)
81			{
82			c = block->data[idx];
83			if (IsEol(c) \|\| (c == ' ' && phase != 1))
84			{
85			empty_bytes++;
86			if (phase == 1)
87			phase = 2;
88			}
89			else switch (phase)
90			{
91			case 0: phase = 1;
92			case 1: if (line_bytes++ < IRCD_BUFSIZE - 2)
93			*buffer++ = c;
94			break;
95			case 2: *buffer = '\0';
96			dbuf_delete(qptr, line_bytes + empty_bytes);
97			return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
98			}
99			}
100			}
101
102			/*
103			* Now, if we haven't reached phase 2, ignore all line bytes
104			* that we have read, since this is a partial line case.
105			*/
106			if (phase != 2)
107			line_bytes = 0;
108			else
109			*buffer = '\0';
110
111			/* Remove what is now unnecessary */
112			dbuf_delete(qptr, line_bytes + empty_bytes);
113			return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
114			}
115
116			/*
117			* parse_client_queued - parse client queued messages
118			*/
119			static void
120			parse_client_queued(struct Client *client_p)
121			{
122			int dolen = 0;
123			int checkflood = 1;
124			struct LocalUser *lclient_p = client_p->localClient;
125
126			if (IsUnknown(client_p))
127			{
128			int i = 0;
129
130			for(;;)
131			{
132			if (IsDefunct(client_p))
133			return;
134
135			/* rate unknown clients at MAX_FLOOD per loop */
136			if (i >= MAX_FLOOD)
137			break;
138
139			dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
140			if (dolen == 0)
141			break;
142
143			client_dopacket(client_p, readBuf, dolen);
144			i++;
145
146			/* if they've dropped out of the unknown state, break and move
147			* to the parsing for their appropriate status. --fl
148			*/
149			if(!IsUnknown(client_p))
150			break;
151			}
152			}
153
154			if (IsServer(client_p) \|\| IsConnecting(client_p) \|\| IsHandshake(client_p))
155			{
156			while (1)
157			{
158			if (IsDefunct(client_p))
159			return;
160			if ((dolen = extract_one_line(&lclient_p->buf_recvq,
161			readBuf)) == 0)
162			break;
163			client_dopacket(client_p, readBuf, dolen);
164			}
165			}
166	adx	163	else if (IsClient(client_p))
167	adx	30	{
168	michael	1219	if (ConfigFileEntry.no_oper_flood && (HasUMode(client_p, UMODE_OPER) \|\| IsCanFlood(client_p)))
169	adx	30	{
170			if (ConfigFileEntry.true_no_oper_flood)
171			checkflood = -1;
172			else
173			checkflood = 0;
174			}
175
176			/*
177			* Handle flood protection here - if we exceed our flood limit on
178			* messages in this loop, we simply drop out of the loop prematurely.
179			* -- adrian
180			*/
181			for (;;)
182			{
183			if (IsDefunct(client_p))
184			break;
185
186			/* This flood protection works as follows:
187			*
188			* A client is given allow_read lines to send to the server. Every
189			* time a line is parsed, sent_parsed is increased. sent_parsed
190			* is decreased by 1 every time flood_recalc is called.
191			*
192			* Thus a client can 'burst' allow_read lines to the server, any
193			* excess lines will be parsed one per flood_recalc() call.
194			*
195			* Therefore a client will be penalised more if they keep flooding,
196			* as sent_parsed will always hover around the allow_read limit
197			* and no 'bursts' will be permitted.
198			*/
199			if (checkflood > 0)
200			{
201			if(lclient_p->sent_parsed >= lclient_p->allow_read)
202			break;
203			}
204
205			/* allow opers 4 times the amount of messages as users. why 4?
206			* why not. :) --fl_
207			*/
208			else if (lclient_p->sent_parsed >= (4 * lclient_p->allow_read) &&
209			checkflood != -1)
210			break;
211
212			dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
213			if (dolen == 0)
214			break;
215
216			client_dopacket(client_p, readBuf, dolen);
217			lclient_p->sent_parsed++;
218			}
219			}
220			}
221
222			/* flood_endgrace()
223			*
224			* marks the end of the clients grace period
225			*/
226			void
227			flood_endgrace(struct Client *client_p)
228			{
229			SetFloodDone(client_p);
230
231			/* Drop their flood limit back down */
232			client_p->localClient->allow_read = MAX_FLOOD;
233
234			/* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
235			* so reset it.
236			*/
237			client_p->localClient->sent_parsed = 0;
238			}
239
240			/*
241			* flood_recalc
242			*
243			* recalculate the number of allowed flood lines. this should be called
244			* once a second on any given client. We then attempt to flush some data.
245			*/
246			void
247			flood_recalc(fde_t fd, void data)
248			{
249			struct Client *client_p = data;
250			struct LocalUser *lclient_p = client_p->localClient;
251
252			/* allow a bursting client their allocation per second, allow
253			* a client whos flooding an extra 2 per second
254			*/
255			if (IsFloodDone(client_p))
256			lclient_p->sent_parsed -= 2;
257			else
258			lclient_p->sent_parsed = 0;
259
260			if (lclient_p->sent_parsed < 0)
261			lclient_p->sent_parsed = 0;
262
263			parse_client_queued(client_p);
264
265			/* And now, try flushing .. */
266			if (!IsDead(client_p))
267			{
268			/* and finally, reset the flood check */
269			comm_setflush(fd, 1000, flood_recalc, client_p);
270			}
271			}
272
273			/*
274	adx	163	* iorecv_default - append a packet to the recvq dbuf
275			*/
276			void *
277			iorecv_default(va_list args)
278			{
279			struct Client client_p = va_arg(args, struct Client );
280			int length = va_arg(args, int);
281			char buf = va_arg(args, char );
282
283			dbuf_put(&client_p->localClient->buf_recvq, buf, length);
284			return NULL;
285			}
286
287			/*
288	adx	30	* read_packet - Read a 'packet' of data from a connection and process it.
289			*/
290			void
291			read_packet(fde_t fd, void data)
292			{
293			struct Client *client_p = data;
294			int length = 0;
295
296			if (IsDefunct(client_p))
297			return;
298
299			/*
300			* Read some data. We used to do anti-flood protection here, but
301			* I personally think it makes the code too hairy to make sane.
302			* -- adrian
303			*/
304			do {
305			#ifdef HAVE_LIBCRYPTO
306			if (fd->ssl)
307			{
308			length = SSL_read(fd->ssl, readBuf, READBUF_SIZE);
309
310			/* translate openssl error codes, sigh */
311			if (length < 0)
312			switch (SSL_get_error(fd->ssl, length))
313			{
314			case SSL_ERROR_WANT_WRITE:
315			fd->flags.pending_read = 1;
316			SetSendqBlocked(client_p);
317			comm_setselect(fd, COMM_SELECT_WRITE, (PF *) sendq_unblocked,
318			client_p, 0);
319			return;
320			case SSL_ERROR_WANT_READ:
321			errno = EWOULDBLOCK;
322			case SSL_ERROR_SYSCALL:
323			break;
324	michael	428	case SSL_ERROR_SSL:
325			if (errno == EAGAIN)
326			break;
327	adx	30	default:
328			length = errno = 0;
329			}
330			}
331			else
332			#endif
333			{
334			length = recv(fd->fd, readBuf, READBUF_SIZE, 0);
335			}
336
337			if (length <= 0)
338			{
339			/*
340			* If true, then we can recover from this error. Just jump out of
341			* the loop and re-register a new io-request.
342			*/
343			if (length < 0 && ignoreErrno(errno))
344			break;
345
346			dead_link_on_read(client_p, length);
347			return;
348			}
349
350			execute_callback(iorecv_cb, client_p, length, readBuf);
351
352	michael	1241	if (client_p->localClient->lasttime < CurrentTime)
353			client_p->localClient->lasttime = CurrentTime;
354			if (client_p->localClient->lasttime > client_p->localClient->since)
355			client_p->localClient->since = CurrentTime;
356	adx	30	ClearPingSent(client_p);
357
358			/* Attempt to parse what we have */
359			parse_client_queued(client_p);
360
361			if (IsDefunct(client_p))
362			return;
363
364			/* Check to make sure we're not flooding */
365			if (!(IsServer(client_p) \|\| IsHandshake(client_p) \|\| IsConnecting(client_p))
366			&& (dbuf_length(&client_p->localClient->buf_recvq) >
367	michael	1516	get_recvq(client_p)))
368	adx	30	{
369	michael	1219	if (!(ConfigFileEntry.no_oper_flood && HasUMode(client_p, UMODE_OPER)))
370	adx	30	{
371			exit_client(client_p, client_p, "Excess Flood");
372			return;
373			}
374			}
375			}
376			#ifdef HAVE_LIBCRYPTO
377			while (length == sizeof(readBuf) \|\| fd->ssl);
378			#else
379			while (length == sizeof(readBuf));
380			#endif
381
382			/* If we get here, we need to register for another COMM_SELECT_READ */
383			comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
384			}
385
386			/*
387			* client_dopacket - copy packet to client buf and parse it
388			* client_p - pointer to client structure for which the buffer data
389			* applies.
390			* buffer - pointr to the buffer containing the newly read data
391			* length - number of valid bytes of data in the buffer
392			*
393			* Note:
394			* It is implicitly assumed that dopacket is called only
395			* with client_p of "local" variation, which contains all the
396			* necessary fields (buffer etc..)
397			*/
398			static void
399			client_dopacket(struct Client client_p, char buffer, size_t length)
400			{
401			/*
402			* Update messages received
403			*/
404			++me.localClient->recv.messages;
405			++client_p->localClient->recv.messages;
406
407			/*
408			* Update bytes received
409			*/
410			client_p->localClient->recv.bytes += length;
411			me.localClient->recv.bytes += length;
412
413			parse(client_p, buffer, buffer + length);
414			}