trunk/src/packet.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 1997-2014 ircd-hybrid development team
 *
 *  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
 */

/*! \file packet.c
 * \brief Packet handlers.
 * \version $Id$
 */

#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

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)
{
  int line_bytes = 0, empty_bytes = 0, phase = 0;
  unsigned int idx = 0;
  dlink_node *ptr = NULL;

  /*
   * 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)
  {
    struct dbuf_block *block = ptr->data;

    if (ptr == qptr->blocks.head)
      idx = qptr->pos;
    else
      idx = 0;

    for (; idx < block->size; ++idx)
    {
      char 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);
  }
}

/*
 * 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:
            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;
    }

    dbuf_put(&client_p->localClient->buf_recvq, readBuf, length);

    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->localClient->confs)))
    {
      if (!(ConfigFileEntry.no_oper_flood && HasUMode(client_p, UMODE_OPER)))
      {
        exit_client(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:	3171
Committed:	Sun Mar 16 11:51:48 2014 UTC (11 years, 5 months ago) by michael
Content type:	text/x-csrc
File size:	10573 byte(s)
Log Message:	- Incorporate Adam's exit_client/quit storm cleanups Note: QS is mandatory now
#	User	Rev	Content
1	adx	30	/*
2	michael	2916	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	adx	30	*
4	michael	2916	* Copyright (c) 1997-2014 ircd-hybrid development team
5	adx	30	*
6			* This program is free software; you can redistribute it and/or modify
7			* it under the terms of the GNU General Public License as published by
8			* the Free Software Foundation; either version 2 of the License, or
9			* (at your option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the GNU General Public License
17			* along with this program; if not, write to the Free Software
18			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
19			* USA
20			*/
21	michael	2916
22			/*! \file packet.c
23			* \brief Packet handlers.
24			* \version $Id$
25			*/
26
27	adx	30	#include "stdinc.h"
28	michael	1011	#include "list.h"
29	adx	30	#include "s_bsd.h"
30	michael	1309	#include "conf.h"
31	adx	30	#include "s_serv.h"
32			#include "client.h"
33			#include "ircd.h"
34			#include "parse.h"
35			#include "fdlist.h"
36			#include "packet.h"
37			#include "irc_string.h"
38			#include "memory.h"
39			#include "hook.h"
40			#include "send.h"
41	michael	1243	#include "s_misc.h"
42	adx	30
43			#define READBUF_SIZE 16384
44
45			static char readBuf[READBUF_SIZE];
46			static void client_dopacket(struct Client , char , size_t);
47
48			/* extract_one_line()
49			*
50			* inputs - pointer to a dbuf queue
51			* - pointer to buffer to copy data to
52			* output - length of <buffer>
53			* side effects - one line is copied and removed from the dbuf
54			*/
55			static int
56			extract_one_line(struct dbuf_queue qptr, char buffer)
57			{
58			int line_bytes = 0, empty_bytes = 0, phase = 0;
59	michael	3107	unsigned int idx = 0;
60			dlink_node *ptr = NULL;
61	adx	30
62			/*
63			* Phase 0: "empty" characters before the line
64			* Phase 1: copying the line
65			* Phase 2: "empty" characters after the line
66			* (delete them as well and free some space in the dbuf)
67			*
68			* Empty characters are CR, LF and space (but, of course, not
69			* in the middle of a line). We try to remove as much of them as we can,
70			* since they simply eat server memory.
71			*
72			* --adx
73			*/
74			DLINK_FOREACH(ptr, qptr->blocks.head)
75			{
76	michael	3107	struct dbuf_block *block = ptr->data;
77	adx	30
78	michael	3107	if (ptr == qptr->blocks.head)
79			idx = qptr->pos;
80			else
81			idx = 0;
82
83			for (; idx < block->size; ++idx)
84	adx	30	{
85	michael	3107	char c = block->data[idx];
86
87	adx	30	if (IsEol(c) \|\| (c == ' ' && phase != 1))
88			{
89	michael	3107	++empty_bytes;
90	adx	30	if (phase == 1)
91			phase = 2;
92			}
93			else switch (phase)
94			{
95			case 0: phase = 1;
96			case 1: if (line_bytes++ < IRCD_BUFSIZE - 2)
97			*buffer++ = c;
98			break;
99			case 2: *buffer = '\0';
100			dbuf_delete(qptr, line_bytes + empty_bytes);
101			return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
102			}
103			}
104			}
105
106			/*
107			* Now, if we haven't reached phase 2, ignore all line bytes
108			* that we have read, since this is a partial line case.
109			*/
110			if (phase != 2)
111			line_bytes = 0;
112			else
113			*buffer = '\0';
114
115			/* Remove what is now unnecessary */
116			dbuf_delete(qptr, line_bytes + empty_bytes);
117			return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
118			}
119			/*
120			* parse_client_queued - parse client queued messages
121			*/
122			static void
123			parse_client_queued(struct Client *client_p)
124	michael	2916	{
125	adx	30	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	michael	2916	for (; ;)
134	adx	30	{
135			if (IsDefunct(client_p))
136	michael	2916	return;
137	adx	30
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	michael	2916	break;
145	adx	30
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	adx	163	else if (IsClient(client_p))
170	adx	30	{
171	michael	1219	if (ConfigFileEntry.no_oper_flood && (HasUMode(client_p, UMODE_OPER) \|\| IsCanFlood(client_p)))
172	adx	30	{
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	michael	2916	for (; ;)
185	adx	30	{
186			if (IsDefunct(client_p))
187	michael	2916	break;
188	adx	30
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	michael	2916
208	adx	30	/* 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	michael	2916
255	adx	30	/* 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	michael	2916
263	adx	30	if (lclient_p->sent_parsed < 0)
264			lclient_p->sent_parsed = 0;
265	michael	2916
266	adx	30	parse_client_queued(client_p);
267	michael	2916
268	adx	30	/* 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_packet - Read a 'packet' of data from a connection and process it.
278			*/
279			void
280			read_packet(fde_t fd, void data)
281			{
282			struct Client *client_p = data;
283			int length = 0;
284
285			if (IsDefunct(client_p))
286			return;
287
288			/*
289			* Read some data. We used to do anti-flood protection here, but
290			* I personally think it makes the code too hairy to make sane.
291			* -- adrian
292			*/
293	michael	2916	do
294			{
295	adx	30	#ifdef HAVE_LIBCRYPTO
296			if (fd->ssl)
297			{
298			length = SSL_read(fd->ssl, readBuf, READBUF_SIZE);
299
300			/* translate openssl error codes, sigh */
301			if (length < 0)
302			switch (SSL_get_error(fd->ssl, length))
303	michael	2881	{
304	adx	30	case SSL_ERROR_WANT_WRITE:
305	michael	2881	comm_setselect(fd, COMM_SELECT_WRITE, (PF *)sendq_unblocked, client_p, 0);
306			return;
307			case SSL_ERROR_WANT_READ:
308			errno = EWOULDBLOCK;
309	adx	30	case SSL_ERROR_SYSCALL:
310	michael	2881	break;
311	michael	428	case SSL_ERROR_SSL:
312			if (errno == EAGAIN)
313			break;
314	adx	30	default:
315	michael	2881	length = errno = 0;
316			}
317	adx	30	}
318			else
319			#endif
320			{
321			length = recv(fd->fd, readBuf, READBUF_SIZE, 0);
322			}
323
324			if (length <= 0)
325			{
326			/*
327			* If true, then we can recover from this error. Just jump out of
328			* the loop and re-register a new io-request.
329			*/
330			if (length < 0 && ignoreErrno(errno))
331			break;
332
333			dead_link_on_read(client_p, length);
334			return;
335			}
336
337	michael	3113	dbuf_put(&client_p->localClient->buf_recvq, readBuf, length);
338	adx	30
339	michael	1241	if (client_p->localClient->lasttime < CurrentTime)
340			client_p->localClient->lasttime = CurrentTime;
341			if (client_p->localClient->lasttime > client_p->localClient->since)
342			client_p->localClient->since = CurrentTime;
343	adx	30	ClearPingSent(client_p);
344
345			/* Attempt to parse what we have */
346			parse_client_queued(client_p);
347
348			if (IsDefunct(client_p))
349			return;
350
351			/* Check to make sure we're not flooding */
352			if (!(IsServer(client_p) \|\| IsHandshake(client_p) \|\| IsConnecting(client_p))
353			&& (dbuf_length(&client_p->localClient->buf_recvq) >
354	michael	1632	get_recvq(&client_p->localClient->confs)))
355	adx	30	{
356	michael	1219	if (!(ConfigFileEntry.no_oper_flood && HasUMode(client_p, UMODE_OPER)))
357	adx	30	{
358	michael	3171	exit_client(client_p, "Excess Flood");
359	adx	30	return;
360			}
361			}
362			}
363			#ifdef HAVE_LIBCRYPTO
364			while (length == sizeof(readBuf) \|\| fd->ssl);
365			#else
366			while (length == sizeof(readBuf));
367			#endif
368
369			/* If we get here, we need to register for another COMM_SELECT_READ */
370			comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
371			}
372
373			/*
374			* client_dopacket - copy packet to client buf and parse it
375			* client_p - pointer to client structure for which the buffer data
376			* applies.
377			* buffer - pointr to the buffer containing the newly read data
378			* length - number of valid bytes of data in the buffer
379			*
380			* Note:
381			* It is implicitly assumed that dopacket is called only
382			* with client_p of "local" variation, which contains all the
383			* necessary fields (buffer etc..)
384			*/
385			static void
386			client_dopacket(struct Client client_p, char buffer, size_t length)
387			{
388	michael	2916	/*
389	adx	30	* Update messages received
390			*/
391			++me.localClient->recv.messages;
392			++client_p->localClient->recv.messages;
393
394	michael	2916	/*
395	adx	30	* Update bytes received
396			*/
397			client_p->localClient->recv.bytes += length;
398			me.localClient->recv.bytes += length;
399
400			parse(client_p, buffer, buffer + length);
401			}