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
#	Content
1	/*
2	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	*
4	* Copyright (c) 1997-2015 ircd-hybrid development team
5	*
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
19	* USA
20	*/
21
22	/*! \file packet.c
23	* \brief Packet handlers.
24	* \version $Id$
25	*/
26
27	#include "stdinc.h"
28	#include "list.h"
29	#include "s_bsd.h"
30	#include "conf.h"
31	#include "server.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 "send.h"
40	#include "misc.h"
41
42	#define READBUF_SIZE 16384
43
44	static char readBuf[READBUF_SIZE];
45
46
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	* It is implicitly assumed that client_dopacket() is called only
56	* 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, unsigned int 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	/* 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 unsigned int
81	extract_one_line(struct dbuf_queue qptr, char buffer)
82	{
83	unsigned int line_bytes = 0, eol_bytes = 0;
84	dlink_node *node;
85
86	DLINK_FOREACH(node, qptr->blocks.head)
87	{
88	const struct dbuf_block *block = node->data;
89	unsigned int idx;
90
91	if (node == qptr->blocks.head)
92	idx = qptr->pos;
93	else
94	idx = 0;
95
96	for (; idx < block->size; ++idx)
97	{
98	char c = block->data[idx];
99
100	if (IsEol(c))
101	{
102	++eol_bytes;
103
104	/* Allow 2 eol bytes per message */
105	if (eol_bytes == 2)
106	goto out;
107	}
108	else if (eol_bytes)
109	goto out;
110	else if (line_bytes++ < IRCD_BUFSIZE - 2)
111	*buffer++ = c;
112	}
113	}
114
115	out:
116
117	/*
118	* Now, if we haven't found an EOL, ignore all line bytes
119	* that we have read, since this is a partial line case.
120	*/
121	if (eol_bytes)
122	*buffer = '\0';
123	else
124	line_bytes = 0;
125
126	/* Remove what is now unnecessary */
127	dbuf_delete(qptr, line_bytes + eol_bytes);
128
129	return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
130	}
131
132	/*
133	* parse_client_queued - parse client queued messages
134	*/
135	static void
136	parse_client_queued(struct Client *client_p)
137	{
138	unsigned int dolen = 0;
139
140	if (IsUnknown(client_p))
141	{
142	unsigned int i = 0;
143
144	while (1)
145	{
146	if (IsDefunct(client_p))
147	return;
148
149	/* Rate unknown clients at MAX_FLOOD per loop */
150	if (i >= MAX_FLOOD)
151	break;
152
153	dolen = extract_one_line(&client_p->connection->buf_recvq, readBuf);
154
155	if (dolen == 0)
156	break;
157
158	client_dopacket(client_p, readBuf, dolen);
159	++i;
160
161	/*
162	* If they've dropped out of the unknown state, break and move
163	* to the parsing for their appropriate status. --fl
164	*/
165	if (!IsUnknown(client_p))
166	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
177	if ((dolen = extract_one_line(&client_p->connection->buf_recvq, readBuf)) == 0)
178	break;
179
180	client_dopacket(client_p, readBuf, dolen);
181	}
182	}
183	else if (IsClient(client_p))
184	{
185	unsigned int checkflood = 1;
186
187	if (ConfigGeneral.no_oper_flood && HasUMode(client_p, UMODE_OPER))
188	checkflood = 0;
189	else if (IsCanFlood(client_p))
190	checkflood = 0;
191
192	/*
193	* 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	* -- adrian
196	*/
197	while (1)
198	{
199	if (IsDefunct(client_p))
200	break;
201
202	/*
203	* This flood protection works as follows:
204	*
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	if (checkflood)
217	if (client_p->connection->sent_parsed >= client_p->connection->allow_read)
218	break;
219
220	dolen = extract_one_line(&client_p->connection->buf_recvq, readBuf);
221
222	if (dolen == 0)
223	break;
224
225	client_dopacket(client_p, readBuf, dolen);
226	++client_p->connection->sent_parsed;
227	}
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	client_p->connection->allow_read = MAX_FLOOD;
242
243	/*
244	* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
245	* so reset it.
246	*/
247	client_p->connection->sent_parsed = 0;
248	}
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	struct Client *const client_p = data;
260
261	/*
262	* Allow a bursting client their allocation per second, allow
263	* a client whos flooding an extra 2 per second
264	*/
265	if (IsFloodDone(client_p))
266	client_p->connection->sent_parsed -= 2;
267	else
268	client_p->connection->sent_parsed = 0;
269
270	if (client_p->connection->sent_parsed < 0)
271	client_p->connection->sent_parsed = 0;
272
273	parse_client_queued(client_p);
274
275	/* 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	struct Client *const client_p = data;
290	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	do
301	{
302	#ifdef HAVE_LIBCRYPTO
303	if (fd->ssl)
304	{
305	length = SSL_read(fd->ssl, readBuf, sizeof(readBuf));
306
307	/* translate openssl error codes, sigh */
308	if (length < 0)
309	switch (SSL_get_error(fd->ssl, length))
310	{
311	case SSL_ERROR_WANT_WRITE:
312	comm_setselect(fd, COMM_SELECT_WRITE, sendq_unblocked, client_p, 0);
313	return;
314	case SSL_ERROR_WANT_READ:
315	errno = EWOULDBLOCK;
316	case SSL_ERROR_SYSCALL:
317	break;
318	case SSL_ERROR_SSL:
319	if (errno == EAGAIN)
320	break;
321	default:
322	length = errno = 0;
323	}
324	}
325	else
326	#endif
327	{
328	length = recv(fd->fd, readBuf, sizeof(readBuf), 0);
329	}
330
331	if (length <= 0)
332	{
333	/*
334	* If true, then we can recover from this error. Just jump out of
335	* 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	dbuf_put(&client_p->connection->buf_recvq, readBuf, length);
345
346	if (client_p->connection->lasttime < CurrentTime)
347	client_p->connection->lasttime = CurrentTime;
348
349	if (client_p->connection->lasttime > client_p->connection->since)
350	client_p->connection->since = CurrentTime;
351
352	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	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	{
365	exit_client(client_p, "Excess Flood");
366	return;
367	}
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	}