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, unsigned int 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 unsigned int
extract_one_line(struct dbuf_queue *qptr, char *buffer)
{
  unsigned int line_bytes = 0, eol_bytes = 0;
  dlink_node *node;

  DLINK_FOREACH(node, qptr->blocks.head)
  {
    const struct dbuf_block *block = node->data;
    unsigned int idx;

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

    for (; idx < block->size; ++idx)
    {
      char c = block->data[idx];

      if (IsEol(c))
      {
        ++eol_bytes;

        /* Allow 2 eol bytes per message */
        if (eol_bytes == 2)
          goto out;
      }
      else if (eol_bytes)
        goto out;
      else if (line_bytes++ < IRCD_BUFSIZE - 2)
        *buffer++ = c;
    }
  }

out:

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

  /* Remove what is now unnecessary */
  dbuf_delete(qptr, line_bytes + eol_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)
{
  unsigned 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:	5545
Committed:	Thu Feb 12 14:13:34 2015 UTC (10 years, 6 months ago) by michael
Content type:	text/x-csrc
File size:	9505 byte(s)
Log Message:	- Fixed style in several places
#	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	michael	5422	client_dopacket(struct Client client_p, char buffer, unsigned int length)
61	michael	4982	{
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	michael	5422	static unsigned int
81	adx	30	extract_one_line(struct dbuf_queue qptr, char buffer)
82			{
83	michael	5422	unsigned int line_bytes = 0, eol_bytes = 0;
84	michael	5421	dlink_node *node;
85	adx	30
86	michael	5421	DLINK_FOREACH(node, qptr->blocks.head)
87	adx	30	{
88	michael	5421	const struct dbuf_block *block = node->data;
89	michael	5413	unsigned int idx;
90	adx	30
91	michael	5421	if (node == qptr->blocks.head)
92	michael	3107	idx = qptr->pos;
93			else
94			idx = 0;
95
96			for (; idx < block->size; ++idx)
97	adx	30	{
98	michael	3107	char c = block->data[idx];
99
100	michael	5413	if (IsEol(c))
101	adx	30	{
102	michael	5413	++eol_bytes;
103	michael	3453
104	michael	5413	/* Allow 2 eol bytes per message */
105			if (eol_bytes == 2)
106			goto out;
107	adx	30	}
108	michael	5413	else if (eol_bytes)
109			goto out;
110			else if (line_bytes++ < IRCD_BUFSIZE - 2)
111			*buffer++ = c;
112	adx	30	}
113			}
114
115	michael	5413	out:
116
117	adx	30	/*
118	michael	5413	* Now, if we haven't found an EOL, ignore all line bytes
119	adx	30	* that we have read, since this is a partial line case.
120			*/
121	michael	5413	if (eol_bytes)
122			*buffer = '\0';
123			else
124	adx	30	line_bytes = 0;
125
126			/* Remove what is now unnecessary */
127	michael	5413	dbuf_delete(qptr, line_bytes + eol_bytes);
128
129	adx	30	return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
130			}
131	michael	5413
132	adx	30	/*
133			* parse_client_queued - parse client queued messages
134			*/
135			static void
136			parse_client_queued(struct Client *client_p)
137	michael	2916	{
138	michael	5422	unsigned int dolen = 0;
139	adx	30
140			if (IsUnknown(client_p))
141			{
142	michael	4982	unsigned int i = 0;
143	adx	30
144	michael	3453	while (1)
145	adx	30	{
146			if (IsDefunct(client_p))
147	michael	2916	return;
148	adx	30
149	michael	4982	/* Rate unknown clients at MAX_FLOOD per loop */
150	adx	30	if (i >= MAX_FLOOD)
151			break;
152
153	michael	4982	dolen = extract_one_line(&client_p->connection->buf_recvq, readBuf);
154	michael	4890
155	adx	30	if (dolen == 0)
156	michael	2916	break;
157	adx	30
158			client_dopacket(client_p, readBuf, dolen);
159	michael	4982	++i;
160	adx	30
161	michael	4982	/*
162			* If they've dropped out of the unknown state, break and move
163	adx	30	* to the parsing for their appropriate status. --fl
164			*/
165	michael	3453	if (!IsUnknown(client_p))
166	adx	30	break;
167			}
168			}
169
170			if (IsServer(client_p) \|\| IsConnecting(client_p) \|\| IsHandshake(client_p))
171			{
172			while (1)
173			{
174			if (IsDefunct(client_p))
175			return;
176	michael	4890
177	michael	4982	if ((dolen = extract_one_line(&client_p->connection->buf_recvq, readBuf)) == 0)
178	adx	30	break;
179	michael	3453
180	adx	30	client_dopacket(client_p, readBuf, dolen);
181			}
182			}
183	adx	163	else if (IsClient(client_p))
184	adx	30	{
185	michael	4989	unsigned int checkflood = 1;
186	adx	30
187	michael	4989	if (ConfigGeneral.no_oper_flood && HasUMode(client_p, UMODE_OPER))
188			checkflood = 0;
189			else if (IsCanFlood(client_p))
190			checkflood = 0;
191
192	adx	30	/*
193	michael	5545	* Handle flood protection here - if we exceed our flood limit on messages
194			* in this loop, we simply drop out of the loop prematurely.
195	adx	30	* -- adrian
196			*/
197	michael	3453	while (1)
198	adx	30	{
199			if (IsDefunct(client_p))
200	michael	2916	break;
201	adx	30
202	michael	4982	/*
203			* This flood protection works as follows:
204	adx	30	*
205			* A client is given allow_read lines to send to the server. Every
206			* time a line is parsed, sent_parsed is increased. sent_parsed
207			* is decreased by 1 every time flood_recalc is called.
208			*
209			* Thus a client can 'burst' allow_read lines to the server, any
210			* excess lines will be parsed one per flood_recalc() call.
211			*
212			* Therefore a client will be penalised more if they keep flooding,
213			* as sent_parsed will always hover around the allow_read limit
214			* and no 'bursts' will be permitted.
215			*/
216	michael	4989	if (checkflood)
217	michael	4982	if (client_p->connection->sent_parsed >= client_p->connection->allow_read)
218	adx	30	break;
219	michael	2916
220	michael	4982	dolen = extract_one_line(&client_p->connection->buf_recvq, readBuf);
221	michael	4890
222	adx	30	if (dolen == 0)
223			break;
224
225			client_dopacket(client_p, readBuf, dolen);
226	michael	4982	++client_p->connection->sent_parsed;
227	adx	30	}
228			}
229			}
230
231			/* flood_endgrace()
232			*
233			* marks the end of the clients grace period
234			*/
235			void
236			flood_endgrace(struct Client *client_p)
237			{
238			SetFloodDone(client_p);
239
240			/* Drop their flood limit back down */
241	michael	4588	client_p->connection->allow_read = MAX_FLOOD;
242	adx	30
243	michael	4982	/*
244			* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
245	adx	30	* so reset it.
246			*/
247	michael	4588	client_p->connection->sent_parsed = 0;
248	adx	30	}
249
250			/*
251			* flood_recalc
252			*
253			* recalculate the number of allowed flood lines. this should be called
254			* once a second on any given client. We then attempt to flush some data.
255			*/
256			void
257			flood_recalc(fde_t fd, void data)
258			{
259	michael	4982	struct Client *const client_p = data;
260	michael	2916
261	michael	4890	/*
262			* Allow a bursting client their allocation per second, allow
263	adx	30	* a client whos flooding an extra 2 per second
264			*/
265			if (IsFloodDone(client_p))
266	michael	4982	client_p->connection->sent_parsed -= 2;
267	adx	30	else
268	michael	4982	client_p->connection->sent_parsed = 0;
269	michael	2916
270	michael	4982	if (client_p->connection->sent_parsed < 0)
271			client_p->connection->sent_parsed = 0;
272	michael	2916
273	adx	30	parse_client_queued(client_p);
274	michael	2916
275	adx	30	/* And now, try flushing .. */
276			if (!IsDead(client_p))
277			{
278			/* and finally, reset the flood check */
279			comm_setflush(fd, 1000, flood_recalc, client_p);
280			}
281			}
282
283			/*
284			* read_packet - Read a 'packet' of data from a connection and process it.
285			*/
286			void
287			read_packet(fde_t fd, void data)
288			{
289	michael	4982	struct Client *const client_p = data;
290	adx	30	int length = 0;
291
292			if (IsDefunct(client_p))
293			return;
294
295			/*
296			* Read some data. We used to do anti-flood protection here, but
297			* I personally think it makes the code too hairy to make sane.
298			* -- adrian
299			*/
300	michael	2916	do
301			{
302	adx	30	#ifdef HAVE_LIBCRYPTO
303			if (fd->ssl)
304			{
305	michael	3453	length = SSL_read(fd->ssl, readBuf, sizeof(readBuf));
306	adx	30
307			/* translate openssl error codes, sigh */
308			if (length < 0)
309			switch (SSL_get_error(fd->ssl, length))
310	michael	2881	{
311	adx	30	case SSL_ERROR_WANT_WRITE:
312	michael	4461	comm_setselect(fd, COMM_SELECT_WRITE, sendq_unblocked, client_p, 0);
313	michael	2881	return;
314			case SSL_ERROR_WANT_READ:
315			errno = EWOULDBLOCK;
316	adx	30	case SSL_ERROR_SYSCALL:
317	michael	2881	break;
318	michael	428	case SSL_ERROR_SSL:
319			if (errno == EAGAIN)
320			break;
321	adx	30	default:
322	michael	2881	length = errno = 0;
323			}
324	adx	30	}
325			else
326			#endif
327			{
328	michael	3453	length = recv(fd->fd, readBuf, sizeof(readBuf), 0);
329	adx	30	}
330
331			if (length <= 0)
332			{
333			/*
334	michael	5545	* If true, then we can recover from this error. Just jump out of
335	adx	30	* the loop and re-register a new io-request.
336			*/
337			if (length < 0 && ignoreErrno(errno))
338			break;
339
340			dead_link_on_read(client_p, length);
341			return;
342			}
343
344	michael	4588	dbuf_put(&client_p->connection->buf_recvq, readBuf, length);
345	adx	30
346	michael	4588	if (client_p->connection->lasttime < CurrentTime)
347			client_p->connection->lasttime = CurrentTime;
348	michael	4890
349	michael	4588	if (client_p->connection->lasttime > client_p->connection->since)
350			client_p->connection->since = CurrentTime;
351	michael	3453
352	adx	30	ClearPingSent(client_p);
353
354			/* Attempt to parse what we have */
355			parse_client_queued(client_p);
356
357			if (IsDefunct(client_p))
358			return;
359
360			/* Check to make sure we're not flooding */
361	michael	4989	if (!(IsServer(client_p) \|\| IsHandshake(client_p) \|\| IsConnecting(client_p)) &&
362			(dbuf_length(&client_p->connection->buf_recvq) >
363			get_recvq(&client_p->connection->confs)))
364	adx	30	{
365	michael	4989	exit_client(client_p, "Excess Flood");
366			return;
367	adx	30	}
368			}
369			#ifdef HAVE_LIBCRYPTO
370			while (length == sizeof(readBuf) \|\| fd->ssl);
371			#else
372			while (length == sizeof(readBuf));
373			#endif
374
375			/* If we get here, we need to register for another COMM_SELECT_READ */
376			comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
377			}