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., 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];
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 *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;
  int checkflood = 1;
  struct Connection *lclient_p = client_p->connection;

  if (IsUnknown(client_p))
  {
    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(&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 (ConfigGeneral.no_oper_flood && (HasUMode(client_p, UMODE_OPER) || IsCanFlood(client_p)))
    {
      if (ConfigGeneral.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
     */
    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 > 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->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 *client_p = data;
  struct Connection *lclient_p = client_p->connection;

  /*
   * 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, 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)))
    {
      if (!(ConfigGeneral.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.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);
}
Revision:	4890
Committed:	Wed Nov 19 17:10:46 2014 UTC (10 years, 9 months ago) by michael
Content type:	text/x-csrc
File size:	10497 byte(s)
Log Message:	- Style corrections
#	Content
1	/*
2	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	*
4	* Copyright (c) 1997-2014 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	static void client_dopacket(struct Client , char , size_t);
46
47	/* extract_one_line()
48	*
49	* inputs - pointer to a dbuf queue
50	* - pointer to buffer to copy data to
51	* output - length of <buffer>
52	* side effects - one line is copied and removed from the dbuf
53	*/
54	static int
55	extract_one_line(struct dbuf_queue qptr, char buffer)
56	{
57	int line_bytes = 0, empty_bytes = 0, phase = 0;
58	unsigned int idx = 0;
59	dlink_node *node = NULL;
60
61	/*
62	* Phase 0: "empty" characters before the line
63	* Phase 1: copying the line
64	* Phase 2: "empty" characters after the line
65	* (delete them as well and free some space in the dbuf)
66	*
67	* Empty characters are CR, LF and space (but, of course, not
68	* in the middle of a line). We try to remove as much of them as we can,
69	* since they simply eat server memory.
70	*
71	* --adx
72	*/
73	DLINK_FOREACH(node, qptr->blocks.head)
74	{
75	struct dbuf_block *block = node->data;
76
77	if (node == qptr->blocks.head)
78	idx = qptr->pos;
79	else
80	idx = 0;
81
82	for (; idx < block->size; ++idx)
83	{
84	char c = block->data[idx];
85
86	if (IsEol(c) \|\| (c == ' ' && phase != 1))
87	{
88	++empty_bytes;
89
90	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	{
125	int dolen = 0;
126	int checkflood = 1;
127	struct Connection *lclient_p = client_p->connection;
128
129	if (IsUnknown(client_p))
130	{
131	int i = 0;
132
133	while (1)
134	{
135	if (IsDefunct(client_p))
136	return;
137
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
144	if (dolen == 0)
145	break;
146
147	client_dopacket(client_p, readBuf, dolen);
148	i++;
149
150	/* if they've dropped out of the unknown state, break and move
151	* to the parsing for their appropriate status. --fl
152	*/
153	if (!IsUnknown(client_p))
154	break;
155	}
156	}
157
158	if (IsServer(client_p) \|\| IsConnecting(client_p) \|\| IsHandshake(client_p))
159	{
160	while (1)
161	{
162	if (IsDefunct(client_p))
163	return;
164
165	if ((dolen = extract_one_line(&lclient_p->buf_recvq, readBuf)) == 0)
166	break;
167
168	client_dopacket(client_p, readBuf, dolen);
169	}
170	}
171	else if (IsClient(client_p))
172	{
173	if (ConfigGeneral.no_oper_flood && (HasUMode(client_p, UMODE_OPER) \|\| IsCanFlood(client_p)))
174	{
175	if (ConfigGeneral.true_no_oper_flood)
176	checkflood = -1;
177	else
178	checkflood = 0;
179	}
180
181	/*
182	* Handle flood protection here - if we exceed our flood limit on
183	* messages in this loop, we simply drop out of the loop prematurely.
184	* -- adrian
185	*/
186	while (1)
187	{
188	if (IsDefunct(client_p))
189	break;
190
191	/* This flood protection works as follows:
192	*
193	* A client is given allow_read lines to send to the server. Every
194	* time a line is parsed, sent_parsed is increased. sent_parsed
195	* is decreased by 1 every time flood_recalc is called.
196	*
197	* Thus a client can 'burst' allow_read lines to the server, any
198	* excess lines will be parsed one per flood_recalc() call.
199	*
200	* Therefore a client will be penalised more if they keep flooding,
201	* as sent_parsed will always hover around the allow_read limit
202	* and no 'bursts' will be permitted.
203	*/
204	if (checkflood > 0)
205	if (lclient_p->sent_parsed >= lclient_p->allow_read)
206	break;
207
208	/*
209	* Allow opers 4 times the amount of messages as users. why 4?
210	* why not. :) --fl_
211	*/
212	else if (lclient_p->sent_parsed >= (4 * lclient_p->allow_read) && checkflood != -1)
213	break;
214
215	dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
216
217	if (dolen == 0)
218	break;
219
220	client_dopacket(client_p, readBuf, dolen);
221	lclient_p->sent_parsed++;
222	}
223	}
224	}
225
226	/* flood_endgrace()
227	*
228	* marks the end of the clients grace period
229	*/
230	void
231	flood_endgrace(struct Client *client_p)
232	{
233	SetFloodDone(client_p);
234
235	/* Drop their flood limit back down */
236	client_p->connection->allow_read = MAX_FLOOD;
237
238	/* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
239	* so reset it.
240	*/
241	client_p->connection->sent_parsed = 0;
242	}
243
244	/*
245	* flood_recalc
246	*
247	* recalculate the number of allowed flood lines. this should be called
248	* once a second on any given client. We then attempt to flush some data.
249	*/
250	void
251	flood_recalc(fde_t fd, void data)
252	{
253	struct Client *client_p = data;
254	struct Connection *lclient_p = client_p->connection;
255
256	/*
257	* Allow a bursting client their allocation per second, allow
258	* a client whos flooding an extra 2 per second
259	*/
260	if (IsFloodDone(client_p))
261	lclient_p->sent_parsed -= 2;
262	else
263	lclient_p->sent_parsed = 0;
264
265	if (lclient_p->sent_parsed < 0)
266	lclient_p->sent_parsed = 0;
267
268	parse_client_queued(client_p);
269
270	/* And now, try flushing .. */
271	if (!IsDead(client_p))
272	{
273	/* and finally, reset the flood check */
274	comm_setflush(fd, 1000, flood_recalc, client_p);
275	}
276	}
277
278	/*
279	* read_packet - Read a 'packet' of data from a connection and process it.
280	*/
281	void
282	read_packet(fde_t fd, void data)
283	{
284	struct Client *client_p = data;
285	int length = 0;
286
287	if (IsDefunct(client_p))
288	return;
289
290	/*
291	* Read some data. We used to do anti-flood protection here, but
292	* I personally think it makes the code too hairy to make sane.
293	* -- adrian
294	*/
295	do
296	{
297	#ifdef HAVE_LIBCRYPTO
298	if (fd->ssl)
299	{
300	length = SSL_read(fd->ssl, readBuf, sizeof(readBuf));
301
302	/* translate openssl error codes, sigh */
303	if (length < 0)
304	switch (SSL_get_error(fd->ssl, length))
305	{
306	case SSL_ERROR_WANT_WRITE:
307	comm_setselect(fd, COMM_SELECT_WRITE, sendq_unblocked, client_p, 0);
308	return;
309	case SSL_ERROR_WANT_READ:
310	errno = EWOULDBLOCK;
311	case SSL_ERROR_SYSCALL:
312	break;
313	case SSL_ERROR_SSL:
314	if (errno == EAGAIN)
315	break;
316	default:
317	length = errno = 0;
318	}
319	}
320	else
321	#endif
322	{
323	length = recv(fd->fd, readBuf, sizeof(readBuf), 0);
324	}
325
326	if (length <= 0)
327	{
328	/*
329	* If true, then we can recover from this error. Just jump out of
330	* the loop and re-register a new io-request.
331	*/
332	if (length < 0 && ignoreErrno(errno))
333	break;
334
335	dead_link_on_read(client_p, length);
336	return;
337	}
338
339	dbuf_put(&client_p->connection->buf_recvq, readBuf, length);
340
341	if (client_p->connection->lasttime < CurrentTime)
342	client_p->connection->lasttime = CurrentTime;
343
344	if (client_p->connection->lasttime > client_p->connection->since)
345	client_p->connection->since = CurrentTime;
346
347	ClearPingSent(client_p);
348
349	/* Attempt to parse what we have */
350	parse_client_queued(client_p);
351
352	if (IsDefunct(client_p))
353	return;
354
355	/* Check to make sure we're not flooding */
356	if (!(IsServer(client_p) \|\| IsHandshake(client_p) \|\| IsConnecting(client_p))
357	&& (dbuf_length(&client_p->connection->buf_recvq) >
358	get_recvq(&client_p->connection->confs)))
359	{
360	if (!(ConfigGeneral.no_oper_flood && HasUMode(client_p, UMODE_OPER)))
361	{
362	exit_client(client_p, "Excess Flood");
363	return;
364	}
365	}
366	}
367	#ifdef HAVE_LIBCRYPTO
368	while (length == sizeof(readBuf) \|\| fd->ssl);
369	#else
370	while (length == sizeof(readBuf));
371	#endif
372
373	/* If we get here, we need to register for another COMM_SELECT_READ */
374	comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
375	}
376
377	/*
378	* client_dopacket - copy packet to client buf and parse it
379	* client_p - pointer to client structure for which the buffer data
380	* applies.
381	* buffer - pointr to the buffer containing the newly read data
382	* length - number of valid bytes of data in the buffer
383	*
384	* Note:
385	* It is implicitly assumed that dopacket is called only
386	* with client_p of "local" variation, which contains all the
387	* necessary fields (buffer etc..)
388	*/
389	static void
390	client_dopacket(struct Client client_p, char buffer, size_t length)
391	{
392	/*
393	* Update messages received
394	*/
395	++me.connection->recv.messages;
396	++client_p->connection->recv.messages;
397
398	/*
399	* Update bytes received
400	*/
401	client_p->connection->recv.bytes += length;
402	me.connection->recv.bytes += length;
403
404	parse(client_p, buffer, buffer + length);
405	}