trunk/src/packet.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 1997-2015 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 *  USA
 */

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

#include "stdinc.h"
#include "list.h"
#include "s_bsd.h"
#include "conf.h"
#include "server.h"
#include "client.h"
#include "ircd.h"
#include "parse.h"
#include "fdlist.h"
#include "packet.h"
#include "irc_string.h"
#include "memory.h"
#include "send.h"
#include "misc.h"

#define READBUF_SIZE 16384

static char readBuf[READBUF_SIZE];


/*
 * 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 client_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.connection->recv.messages;
  ++client_p->connection->recv.messages;

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

  parse(client_p, buffer, buffer + length);
}

/* 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 *node = 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(node, qptr->blocks.head)
  {
    struct dbuf_block *block = node->data;

    if (node == 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;

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

    while (1)
    {
      if (IsDefunct(client_p))
        return;

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

      dolen = extract_one_line(&client_p->connection->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(&client_p->connection->buf_recvq, readBuf)) == 0)
        break;

      client_dopacket(client_p, readBuf, dolen);
    }
  }
  else if (IsClient(client_p))
  {
    unsigned int checkflood = 1;

    if (ConfigGeneral.no_oper_flood && HasUMode(client_p, UMODE_OPER))
      checkflood = 0;
    else if (IsCanFlood(client_p))
      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
     */
    while (1)
    {
      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)
        if (client_p->connection->sent_parsed >= client_p->connection->allow_read)
          break;

      dolen = extract_one_line(&client_p->connection->buf_recvq, readBuf);

      if (dolen == 0)
        break;

      client_dopacket(client_p, readBuf, dolen);
      ++client_p->connection->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->connection->allow_read = MAX_FLOOD;

  /*
   * sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
   * so reset it.
   */
  client_p->connection->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 *const client_p = data;

  /*
   * Allow a bursting client their allocation per second, allow
   * a client whos flooding an extra 2 per second
   */
  if (IsFloodDone(client_p))
    client_p->connection->sent_parsed -= 2;
  else
    client_p->connection->sent_parsed = 0;

  if (client_p->connection->sent_parsed < 0)
    client_p->connection->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 *const 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, sizeof(readBuf));

      /* 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, 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, sizeof(readBuf), 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->connection->buf_recvq, readBuf, length);

    if (client_p->connection->lasttime < CurrentTime)
      client_p->connection->lasttime = CurrentTime;

    if (client_p->connection->lasttime > client_p->connection->since)
      client_p->connection->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->connection->buf_recvq) >
         get_recvq(&client_p->connection->confs)))
    {
      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);
}
Revision:	5347
Committed:	Sun Jan 11 12:42:20 2015 UTC (10 years, 7 months ago) by michael
Content type:	text/x-csrc
File size:	10098 byte(s)
Log Message:	- Update copyright years
#	User	Rev	Content
1	adx	30	/*
2	michael	2916	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	adx	30	*
4	michael	5347	* Copyright (c) 1997-2015 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	michael	4565	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
19	adx	30	* 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	michael	3347	#include "server.h"
32	adx	30	#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 "send.h"
40	michael	3347	#include "misc.h"
41	adx	30
42			#define READBUF_SIZE 16384
43
44			static char readBuf[READBUF_SIZE];
45
46	michael	4982
47			/*
48			* client_dopacket - copy packet to client buf and parse it
49			* client_p - pointer to client structure for which the buffer data
50			* applies.
51			* buffer - pointr to the buffer containing the newly read data
52			* length - number of valid bytes of data in the buffer
53			*
54			* Note:
55	michael	4989	* It is implicitly assumed that client_dopacket() is called only
56	michael	4982	* with client_p of "local" variation, which contains all the
57			* necessary fields (buffer etc..)
58			*/
59			static void
60			client_dopacket(struct Client client_p, char buffer, size_t length)
61			{
62			/* Update messages received */
63			++me.connection->recv.messages;
64			++client_p->connection->recv.messages;
65
66			/* Update bytes received */
67			client_p->connection->recv.bytes += length;
68			me.connection->recv.bytes += length;
69
70			parse(client_p, buffer, buffer + length);
71			}
72
73	adx	30	/* extract_one_line()
74			*
75			* inputs - pointer to a dbuf queue
76			* - pointer to buffer to copy data to
77			* output - length of <buffer>
78			* side effects - one line is copied and removed from the dbuf
79			*/
80			static int
81			extract_one_line(struct dbuf_queue qptr, char buffer)
82			{
83			int line_bytes = 0, empty_bytes = 0, phase = 0;
84	michael	3107	unsigned int idx = 0;
85	michael	4815	dlink_node *node = NULL;
86	adx	30
87			/*
88			* Phase 0: "empty" characters before the line
89			* Phase 1: copying the line
90			* Phase 2: "empty" characters after the line
91			* (delete them as well and free some space in the dbuf)
92			*
93			* Empty characters are CR, LF and space (but, of course, not
94			* in the middle of a line). We try to remove as much of them as we can,
95			* since they simply eat server memory.
96			*
97			* --adx
98			*/
99	michael	4815	DLINK_FOREACH(node, qptr->blocks.head)
100	adx	30	{
101	michael	4815	struct dbuf_block *block = node->data;
102	adx	30
103	michael	4815	if (node == qptr->blocks.head)
104	michael	3107	idx = qptr->pos;
105			else
106			idx = 0;
107
108			for (; idx < block->size; ++idx)
109	adx	30	{
110	michael	3107	char c = block->data[idx];
111
112	adx	30	if (IsEol(c) \|\| (c == ' ' && phase != 1))
113			{
114	michael	3107	++empty_bytes;
115	michael	3453
116	adx	30	if (phase == 1)
117			phase = 2;
118			}
119			else switch (phase)
120			{
121			case 0: phase = 1;
122			case 1: if (line_bytes++ < IRCD_BUFSIZE - 2)
123			*buffer++ = c;
124			break;
125			case 2: *buffer = '\0';
126			dbuf_delete(qptr, line_bytes + empty_bytes);
127			return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
128			}
129			}
130			}
131
132			/*
133			* Now, if we haven't reached phase 2, ignore all line bytes
134			* that we have read, since this is a partial line case.
135			*/
136			if (phase != 2)
137			line_bytes = 0;
138			else
139			*buffer = '\0';
140
141			/* Remove what is now unnecessary */
142			dbuf_delete(qptr, line_bytes + empty_bytes);
143			return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
144			}
145			/*
146			* parse_client_queued - parse client queued messages
147			*/
148			static void
149			parse_client_queued(struct Client *client_p)
150	michael	2916	{
151	adx	30	int dolen = 0;
152
153			if (IsUnknown(client_p))
154			{
155	michael	4982	unsigned int i = 0;
156	adx	30
157	michael	3453	while (1)
158	adx	30	{
159			if (IsDefunct(client_p))
160	michael	2916	return;
161	adx	30
162	michael	4982	/* Rate unknown clients at MAX_FLOOD per loop */
163	adx	30	if (i >= MAX_FLOOD)
164			break;
165
166	michael	4982	dolen = extract_one_line(&client_p->connection->buf_recvq, readBuf);
167	michael	4890
168	adx	30	if (dolen == 0)
169	michael	2916	break;
170	adx	30
171			client_dopacket(client_p, readBuf, dolen);
172	michael	4982	++i;
173	adx	30
174	michael	4982	/*
175			* If they've dropped out of the unknown state, break and move
176	adx	30	* to the parsing for their appropriate status. --fl
177			*/
178	michael	3453	if (!IsUnknown(client_p))
179	adx	30	break;
180			}
181			}
182
183			if (IsServer(client_p) \|\| IsConnecting(client_p) \|\| IsHandshake(client_p))
184			{
185			while (1)
186			{
187			if (IsDefunct(client_p))
188			return;
189	michael	4890
190	michael	4982	if ((dolen = extract_one_line(&client_p->connection->buf_recvq, readBuf)) == 0)
191	adx	30	break;
192	michael	3453
193	adx	30	client_dopacket(client_p, readBuf, dolen);
194			}
195			}
196	adx	163	else if (IsClient(client_p))
197	adx	30	{
198	michael	4989	unsigned int checkflood = 1;
199	adx	30
200	michael	4989	if (ConfigGeneral.no_oper_flood && HasUMode(client_p, UMODE_OPER))
201			checkflood = 0;
202			else if (IsCanFlood(client_p))
203			checkflood = 0;
204
205	adx	30	/*
206			* Handle flood protection here - if we exceed our flood limit on
207			* messages in this loop, we simply drop out of the loop prematurely.
208			* -- adrian
209			*/
210	michael	3453	while (1)
211	adx	30	{
212			if (IsDefunct(client_p))
213	michael	2916	break;
214	adx	30
215	michael	4982	/*
216			* This flood protection works as follows:
217	adx	30	*
218			* A client is given allow_read lines to send to the server. Every
219			* time a line is parsed, sent_parsed is increased. sent_parsed
220			* is decreased by 1 every time flood_recalc is called.
221			*
222			* Thus a client can 'burst' allow_read lines to the server, any
223			* excess lines will be parsed one per flood_recalc() call.
224			*
225			* Therefore a client will be penalised more if they keep flooding,
226			* as sent_parsed will always hover around the allow_read limit
227			* and no 'bursts' will be permitted.
228			*/
229	michael	4989	if (checkflood)
230	michael	4982	if (client_p->connection->sent_parsed >= client_p->connection->allow_read)
231	adx	30	break;
232	michael	2916
233	michael	4982	dolen = extract_one_line(&client_p->connection->buf_recvq, readBuf);
234	michael	4890
235	adx	30	if (dolen == 0)
236			break;
237
238			client_dopacket(client_p, readBuf, dolen);
239	michael	4982	++client_p->connection->sent_parsed;
240	adx	30	}
241			}
242			}
243
244			/* flood_endgrace()
245			*
246			* marks the end of the clients grace period
247			*/
248			void
249			flood_endgrace(struct Client *client_p)
250			{
251			SetFloodDone(client_p);
252
253			/* Drop their flood limit back down */
254	michael	4588	client_p->connection->allow_read = MAX_FLOOD;
255	adx	30
256	michael	4982	/*
257			* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
258	adx	30	* so reset it.
259			*/
260	michael	4588	client_p->connection->sent_parsed = 0;
261	adx	30	}
262
263			/*
264			* flood_recalc
265			*
266			* recalculate the number of allowed flood lines. this should be called
267			* once a second on any given client. We then attempt to flush some data.
268			*/
269			void
270			flood_recalc(fde_t fd, void data)
271			{
272	michael	4982	struct Client *const client_p = data;
273	michael	2916
274	michael	4890	/*
275			* Allow a bursting client their allocation per second, allow
276	adx	30	* a client whos flooding an extra 2 per second
277			*/
278			if (IsFloodDone(client_p))
279	michael	4982	client_p->connection->sent_parsed -= 2;
280	adx	30	else
281	michael	4982	client_p->connection->sent_parsed = 0;
282	michael	2916
283	michael	4982	if (client_p->connection->sent_parsed < 0)
284			client_p->connection->sent_parsed = 0;
285	michael	2916
286	adx	30	parse_client_queued(client_p);
287	michael	2916
288	adx	30	/* And now, try flushing .. */
289			if (!IsDead(client_p))
290			{
291			/* and finally, reset the flood check */
292			comm_setflush(fd, 1000, flood_recalc, client_p);
293			}
294			}
295
296			/*
297			* read_packet - Read a 'packet' of data from a connection and process it.
298			*/
299			void
300			read_packet(fde_t fd, void data)
301			{
302	michael	4982	struct Client *const client_p = data;
303	adx	30	int length = 0;
304
305			if (IsDefunct(client_p))
306			return;
307
308			/*
309			* Read some data. We used to do anti-flood protection here, but
310			* I personally think it makes the code too hairy to make sane.
311			* -- adrian
312			*/
313	michael	2916	do
314			{
315	adx	30	#ifdef HAVE_LIBCRYPTO
316			if (fd->ssl)
317			{
318	michael	3453	length = SSL_read(fd->ssl, readBuf, sizeof(readBuf));
319	adx	30
320			/* translate openssl error codes, sigh */
321			if (length < 0)
322			switch (SSL_get_error(fd->ssl, length))
323	michael	2881	{
324	adx	30	case SSL_ERROR_WANT_WRITE:
325	michael	4461	comm_setselect(fd, COMM_SELECT_WRITE, sendq_unblocked, client_p, 0);
326	michael	2881	return;
327			case SSL_ERROR_WANT_READ:
328			errno = EWOULDBLOCK;
329	adx	30	case SSL_ERROR_SYSCALL:
330	michael	2881	break;
331	michael	428	case SSL_ERROR_SSL:
332			if (errno == EAGAIN)
333			break;
334	adx	30	default:
335	michael	2881	length = errno = 0;
336			}
337	adx	30	}
338			else
339			#endif
340			{
341	michael	3453	length = recv(fd->fd, readBuf, sizeof(readBuf), 0);
342	adx	30	}
343
344			if (length <= 0)
345			{
346			/*
347			* If true, then we can recover from this error. Just jump out of
348			* the loop and re-register a new io-request.
349			*/
350			if (length < 0 && ignoreErrno(errno))
351			break;
352
353			dead_link_on_read(client_p, length);
354			return;
355			}
356
357	michael	4588	dbuf_put(&client_p->connection->buf_recvq, readBuf, length);
358	adx	30
359	michael	4588	if (client_p->connection->lasttime < CurrentTime)
360			client_p->connection->lasttime = CurrentTime;
361	michael	4890
362	michael	4588	if (client_p->connection->lasttime > client_p->connection->since)
363			client_p->connection->since = CurrentTime;
364	michael	3453
365	adx	30	ClearPingSent(client_p);
366
367			/* Attempt to parse what we have */
368			parse_client_queued(client_p);
369
370			if (IsDefunct(client_p))
371			return;
372
373			/* Check to make sure we're not flooding */
374	michael	4989	if (!(IsServer(client_p) \|\| IsHandshake(client_p) \|\| IsConnecting(client_p)) &&
375			(dbuf_length(&client_p->connection->buf_recvq) >
376			get_recvq(&client_p->connection->confs)))
377	adx	30	{
378	michael	4989	exit_client(client_p, "Excess Flood");
379			return;
380	adx	30	}
381			}
382			#ifdef HAVE_LIBCRYPTO
383			while (length == sizeof(readBuf) \|\| fd->ssl);
384			#else
385			while (length == sizeof(readBuf));
386			#endif
387
388			/* If we get here, we need to register for another COMM_SELECT_READ */
389			comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
390			}