trunk/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

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);
  }
}

/*
 * 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, 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:	2881
Committed:	Mon Jan 20 17:15:39 2014 UTC (11 years, 7 months ago) by michael
Content type:	text/x-csrc
File size:	10478 byte(s)
Log Message:	- Use the i/o subsystem to execute scheduled writes. Patch provided by Adam.
#	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			static char readBuf[READBUF_SIZE];
43			static void client_dopacket(struct Client , char , size_t);
44
45			/* extract_one_line()
46			*
47			* inputs - pointer to a dbuf queue
48			* - pointer to buffer to copy data to
49			* output - length of <buffer>
50			* side effects - one line is copied and removed from the dbuf
51			*/
52			static int
53			extract_one_line(struct dbuf_queue qptr, char buffer)
54			{
55			struct dbuf_block *block;
56			int line_bytes = 0, empty_bytes = 0, phase = 0;
57			unsigned int idx;
58
59			char c;
60			dlink_node *ptr;
61
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			block = ptr->data;
77
78			for (idx = 0; idx < block->size; idx++)
79			{
80			c = block->data[idx];
81			if (IsEol(c) \|\| (c == ' ' && phase != 1))
82			{
83			empty_bytes++;
84			if (phase == 1)
85			phase = 2;
86			}
87			else switch (phase)
88			{
89			case 0: phase = 1;
90			case 1: if (line_bytes++ < IRCD_BUFSIZE - 2)
91			*buffer++ = c;
92			break;
93			case 2: *buffer = '\0';
94			dbuf_delete(qptr, line_bytes + empty_bytes);
95			return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
96			}
97			}
98			}
99
100			/*
101			* Now, if we haven't reached phase 2, ignore all line bytes
102			* that we have read, since this is a partial line case.
103			*/
104			if (phase != 2)
105			line_bytes = 0;
106			else
107			*buffer = '\0';
108
109			/* Remove what is now unnecessary */
110			dbuf_delete(qptr, line_bytes + empty_bytes);
111			return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
112			}
113
114			/*
115			* parse_client_queued - parse client queued messages
116			*/
117			static void
118			parse_client_queued(struct Client *client_p)
119			{
120			int dolen = 0;
121			int checkflood = 1;
122			struct LocalUser *lclient_p = client_p->localClient;
123
124			if (IsUnknown(client_p))
125			{
126			int i = 0;
127
128			for(;;)
129			{
130			if (IsDefunct(client_p))
131			return;
132
133			/* rate unknown clients at MAX_FLOOD per loop */
134			if (i >= MAX_FLOOD)
135			break;
136
137			dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
138			if (dolen == 0)
139			break;
140
141			client_dopacket(client_p, readBuf, dolen);
142			i++;
143
144			/* if they've dropped out of the unknown state, break and move
145			* to the parsing for their appropriate status. --fl
146			*/
147			if(!IsUnknown(client_p))
148			break;
149			}
150			}
151
152			if (IsServer(client_p) \|\| IsConnecting(client_p) \|\| IsHandshake(client_p))
153			{
154			while (1)
155			{
156			if (IsDefunct(client_p))
157			return;
158			if ((dolen = extract_one_line(&lclient_p->buf_recvq,
159			readBuf)) == 0)
160			break;
161			client_dopacket(client_p, readBuf, dolen);
162			}
163			}
164	adx	163	else if (IsClient(client_p))
165	adx	30	{
166	michael	1219	if (ConfigFileEntry.no_oper_flood && (HasUMode(client_p, UMODE_OPER) \|\| IsCanFlood(client_p)))
167	adx	30	{
168			if (ConfigFileEntry.true_no_oper_flood)
169			checkflood = -1;
170			else
171			checkflood = 0;
172			}
173
174			/*
175			* Handle flood protection here - if we exceed our flood limit on
176			* messages in this loop, we simply drop out of the loop prematurely.
177			* -- adrian
178			*/
179			for (;;)
180			{
181			if (IsDefunct(client_p))
182			break;
183
184			/* This flood protection works as follows:
185			*
186			* A client is given allow_read lines to send to the server. Every
187			* time a line is parsed, sent_parsed is increased. sent_parsed
188			* is decreased by 1 every time flood_recalc is called.
189			*
190			* Thus a client can 'burst' allow_read lines to the server, any
191			* excess lines will be parsed one per flood_recalc() call.
192			*
193			* Therefore a client will be penalised more if they keep flooding,
194			* as sent_parsed will always hover around the allow_read limit
195			* and no 'bursts' will be permitted.
196			*/
197			if (checkflood > 0)
198			{
199			if(lclient_p->sent_parsed >= lclient_p->allow_read)
200			break;
201			}
202
203			/* allow opers 4 times the amount of messages as users. why 4?
204			* why not. :) --fl_
205			*/
206			else if (lclient_p->sent_parsed >= (4 * lclient_p->allow_read) &&
207			checkflood != -1)
208			break;
209
210			dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
211			if (dolen == 0)
212			break;
213
214			client_dopacket(client_p, readBuf, dolen);
215			lclient_p->sent_parsed++;
216			}
217			}
218			}
219
220			/* flood_endgrace()
221			*
222			* marks the end of the clients grace period
223			*/
224			void
225			flood_endgrace(struct Client *client_p)
226			{
227			SetFloodDone(client_p);
228
229			/* Drop their flood limit back down */
230			client_p->localClient->allow_read = MAX_FLOOD;
231
232			/* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
233			* so reset it.
234			*/
235			client_p->localClient->sent_parsed = 0;
236			}
237
238			/*
239			* flood_recalc
240			*
241			* recalculate the number of allowed flood lines. this should be called
242			* once a second on any given client. We then attempt to flush some data.
243			*/
244			void
245			flood_recalc(fde_t fd, void data)
246			{
247			struct Client *client_p = data;
248			struct LocalUser *lclient_p = client_p->localClient;
249
250			/* allow a bursting client their allocation per second, allow
251			* a client whos flooding an extra 2 per second
252			*/
253			if (IsFloodDone(client_p))
254			lclient_p->sent_parsed -= 2;
255			else
256			lclient_p->sent_parsed = 0;
257
258			if (lclient_p->sent_parsed < 0)
259			lclient_p->sent_parsed = 0;
260
261			parse_client_queued(client_p);
262
263			/* And now, try flushing .. */
264			if (!IsDead(client_p))
265			{
266			/* and finally, reset the flood check */
267			comm_setflush(fd, 1000, flood_recalc, client_p);
268			}
269			}
270
271			/*
272			* read_packet - Read a 'packet' of data from a connection and process it.
273			*/
274			void
275			read_packet(fde_t fd, void data)
276			{
277			struct Client *client_p = data;
278			int length = 0;
279
280			if (IsDefunct(client_p))
281			return;
282
283			/*
284			* Read some data. We used to do anti-flood protection here, but
285			* I personally think it makes the code too hairy to make sane.
286			* -- adrian
287			*/
288			do {
289			#ifdef HAVE_LIBCRYPTO
290			if (fd->ssl)
291			{
292			length = SSL_read(fd->ssl, readBuf, READBUF_SIZE);
293
294			/* translate openssl error codes, sigh */
295			if (length < 0)
296			switch (SSL_get_error(fd->ssl, length))
297	michael	2881	{
298	adx	30	case SSL_ERROR_WANT_WRITE:
299	michael	2881	comm_setselect(fd, COMM_SELECT_WRITE, (PF *)sendq_unblocked, client_p, 0);
300			return;
301			case SSL_ERROR_WANT_READ:
302			errno = EWOULDBLOCK;
303	adx	30	case SSL_ERROR_SYSCALL:
304	michael	2881	break;
305	michael	428	case SSL_ERROR_SSL:
306			if (errno == EAGAIN)
307			break;
308	adx	30	default:
309	michael	2881	length = errno = 0;
310			}
311	adx	30	}
312			else
313			#endif
314			{
315			length = recv(fd->fd, readBuf, READBUF_SIZE, 0);
316			}
317
318			if (length <= 0)
319			{
320			/*
321			* If true, then we can recover from this error. Just jump out of
322			* the loop and re-register a new io-request.
323			*/
324			if (length < 0 && ignoreErrno(errno))
325			break;
326
327			dead_link_on_read(client_p, length);
328			return;
329			}
330
331	michael	1798	dbuf_put(&client_p->localClient->buf_recvq, readBuf, length);
332	adx	30
333	michael	1241	if (client_p->localClient->lasttime < CurrentTime)
334			client_p->localClient->lasttime = CurrentTime;
335			if (client_p->localClient->lasttime > client_p->localClient->since)
336			client_p->localClient->since = CurrentTime;
337	adx	30	ClearPingSent(client_p);
338
339			/* Attempt to parse what we have */
340			parse_client_queued(client_p);
341
342			if (IsDefunct(client_p))
343			return;
344
345			/* Check to make sure we're not flooding */
346			if (!(IsServer(client_p) \|\| IsHandshake(client_p) \|\| IsConnecting(client_p))
347			&& (dbuf_length(&client_p->localClient->buf_recvq) >
348	michael	1632	get_recvq(&client_p->localClient->confs)))
349	adx	30	{
350	michael	1219	if (!(ConfigFileEntry.no_oper_flood && HasUMode(client_p, UMODE_OPER)))
351	adx	30	{
352			exit_client(client_p, client_p, "Excess Flood");
353			return;
354			}
355			}
356			}
357			#ifdef HAVE_LIBCRYPTO
358			while (length == sizeof(readBuf) \|\| fd->ssl);
359			#else
360			while (length == sizeof(readBuf));
361			#endif
362
363			/* If we get here, we need to register for another COMM_SELECT_READ */
364			comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
365			}
366
367			/*
368			* client_dopacket - copy packet to client buf and parse it
369			* client_p - pointer to client structure for which the buffer data
370			* applies.
371			* buffer - pointr to the buffer containing the newly read data
372			* length - number of valid bytes of data in the buffer
373			*
374			* Note:
375			* It is implicitly assumed that dopacket is called only
376			* with client_p of "local" variation, which contains all the
377			* necessary fields (buffer etc..)
378			*/
379			static void
380			client_dopacket(struct Client client_p, char buffer, size_t length)
381			{
382			/*
383			* Update messages received
384			*/
385			++me.localClient->recv.messages;
386			++client_p->localClient->recv.messages;
387
388			/*
389			* Update bytes received
390			*/
391			client_p->localClient->recv.bytes += length;
392			me.localClient->recv.bytes += length;
393
394			parse(client_p, buffer, buffer + length);
395			}