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., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 */

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

#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 "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)
{
  int line_bytes = 0, empty_bytes = 0, phase = 0;
  unsigned int idx = 0;
  dlink_node *ptr = 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(ptr, qptr->blocks.head)
  {
    struct dbuf_block *block = ptr->data;

    if (ptr == 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 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, "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:	3274
Committed:	Sun Apr 6 12:22:23 2014 UTC (11 years, 4 months ago) by michael
Content type:	text/x-csrc
File size:	10555 byte(s)
Log Message:	- Clean up redundant/unused header includes
#	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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
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 "s_serv.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 "s_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 *ptr = 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(ptr, qptr->blocks.head)
74	{
75	struct dbuf_block *block = ptr->data;
76
77	if (ptr == 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	if (phase == 1)
90	phase = 2;
91	}
92	else switch (phase)
93	{
94	case 0: phase = 1;
95	case 1: if (line_bytes++ < IRCD_BUFSIZE - 2)
96	*buffer++ = c;
97	break;
98	case 2: *buffer = '\0';
99	dbuf_delete(qptr, line_bytes + empty_bytes);
100	return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
101	}
102	}
103	}
104
105	/*
106	* Now, if we haven't reached phase 2, ignore all line bytes
107	* that we have read, since this is a partial line case.
108	*/
109	if (phase != 2)
110	line_bytes = 0;
111	else
112	*buffer = '\0';
113
114	/* Remove what is now unnecessary */
115	dbuf_delete(qptr, line_bytes + empty_bytes);
116	return IRCD_MIN(line_bytes, IRCD_BUFSIZE - 2);
117	}
118	/*
119	* parse_client_queued - parse client queued messages
120	*/
121	static void
122	parse_client_queued(struct Client *client_p)
123	{
124	int dolen = 0;
125	int checkflood = 1;
126	struct LocalUser *lclient_p = client_p->localClient;
127
128	if (IsUnknown(client_p))
129	{
130	int i = 0;
131
132	for (; ;)
133	{
134	if (IsDefunct(client_p))
135	return;
136
137	/* rate unknown clients at MAX_FLOOD per loop */
138	if (i >= MAX_FLOOD)
139	break;
140
141	dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
142	if (dolen == 0)
143	break;
144
145	client_dopacket(client_p, readBuf, dolen);
146	i++;
147
148	/* if they've dropped out of the unknown state, break and move
149	* to the parsing for their appropriate status. --fl
150	*/
151	if(!IsUnknown(client_p))
152	break;
153	}
154	}
155
156	if (IsServer(client_p) \|\| IsConnecting(client_p) \|\| IsHandshake(client_p))
157	{
158	while (1)
159	{
160	if (IsDefunct(client_p))
161	return;
162	if ((dolen = extract_one_line(&lclient_p->buf_recvq,
163	readBuf)) == 0)
164	break;
165	client_dopacket(client_p, readBuf, dolen);
166	}
167	}
168	else if (IsClient(client_p))
169	{
170	if (ConfigFileEntry.no_oper_flood && (HasUMode(client_p, UMODE_OPER) \|\| IsCanFlood(client_p)))
171	{
172	if (ConfigFileEntry.true_no_oper_flood)
173	checkflood = -1;
174	else
175	checkflood = 0;
176	}
177
178	/*
179	* Handle flood protection here - if we exceed our flood limit on
180	* messages in this loop, we simply drop out of the loop prematurely.
181	* -- adrian
182	*/
183	for (; ;)
184	{
185	if (IsDefunct(client_p))
186	break;
187
188	/* This flood protection works as follows:
189	*
190	* A client is given allow_read lines to send to the server. Every
191	* time a line is parsed, sent_parsed is increased. sent_parsed
192	* is decreased by 1 every time flood_recalc is called.
193	*
194	* Thus a client can 'burst' allow_read lines to the server, any
195	* excess lines will be parsed one per flood_recalc() call.
196	*
197	* Therefore a client will be penalised more if they keep flooding,
198	* as sent_parsed will always hover around the allow_read limit
199	* and no 'bursts' will be permitted.
200	*/
201	if (checkflood > 0)
202	{
203	if(lclient_p->sent_parsed >= lclient_p->allow_read)
204	break;
205	}
206
207	/* allow opers 4 times the amount of messages as users. why 4?
208	* why not. :) --fl_
209	*/
210	else if (lclient_p->sent_parsed >= (4 * lclient_p->allow_read) &&
211	checkflood != -1)
212	break;
213
214	dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
215	if (dolen == 0)
216	break;
217
218	client_dopacket(client_p, readBuf, dolen);
219	lclient_p->sent_parsed++;
220	}
221	}
222	}
223
224	/* flood_endgrace()
225	*
226	* marks the end of the clients grace period
227	*/
228	void
229	flood_endgrace(struct Client *client_p)
230	{
231	SetFloodDone(client_p);
232
233	/* Drop their flood limit back down */
234	client_p->localClient->allow_read = MAX_FLOOD;
235
236	/* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
237	* so reset it.
238	*/
239	client_p->localClient->sent_parsed = 0;
240	}
241
242	/*
243	* flood_recalc
244	*
245	* recalculate the number of allowed flood lines. this should be called
246	* once a second on any given client. We then attempt to flush some data.
247	*/
248	void
249	flood_recalc(fde_t fd, void data)
250	{
251	struct Client *client_p = data;
252	struct LocalUser *lclient_p = client_p->localClient;
253
254	/* allow a bursting client their allocation per second, allow
255	* a client whos flooding an extra 2 per second
256	*/
257	if (IsFloodDone(client_p))
258	lclient_p->sent_parsed -= 2;
259	else
260	lclient_p->sent_parsed = 0;
261
262	if (lclient_p->sent_parsed < 0)
263	lclient_p->sent_parsed = 0;
264
265	parse_client_queued(client_p);
266
267	/* And now, try flushing .. */
268	if (!IsDead(client_p))
269	{
270	/* and finally, reset the flood check */
271	comm_setflush(fd, 1000, flood_recalc, client_p);
272	}
273	}
274
275	/*
276	* read_packet - Read a 'packet' of data from a connection and process it.
277	*/
278	void
279	read_packet(fde_t fd, void data)
280	{
281	struct Client *client_p = data;
282	int length = 0;
283
284	if (IsDefunct(client_p))
285	return;
286
287	/*
288	* Read some data. We used to do anti-flood protection here, but
289	* I personally think it makes the code too hairy to make sane.
290	* -- adrian
291	*/
292	do
293	{
294	#ifdef HAVE_LIBCRYPTO
295	if (fd->ssl)
296	{
297	length = SSL_read(fd->ssl, readBuf, READBUF_SIZE);
298
299	/* translate openssl error codes, sigh */
300	if (length < 0)
301	switch (SSL_get_error(fd->ssl, length))
302	{
303	case SSL_ERROR_WANT_WRITE:
304	comm_setselect(fd, COMM_SELECT_WRITE, (PF *)sendq_unblocked, client_p, 0);
305	return;
306	case SSL_ERROR_WANT_READ:
307	errno = EWOULDBLOCK;
308	case SSL_ERROR_SYSCALL:
309	break;
310	case SSL_ERROR_SSL:
311	if (errno == EAGAIN)
312	break;
313	default:
314	length = errno = 0;
315	}
316	}
317	else
318	#endif
319	{
320	length = recv(fd->fd, readBuf, READBUF_SIZE, 0);
321	}
322
323	if (length <= 0)
324	{
325	/*
326	* If true, then we can recover from this error. Just jump out of
327	* the loop and re-register a new io-request.
328	*/
329	if (length < 0 && ignoreErrno(errno))
330	break;
331
332	dead_link_on_read(client_p, length);
333	return;
334	}
335
336	dbuf_put(&client_p->localClient->buf_recvq, readBuf, length);
337
338	if (client_p->localClient->lasttime < CurrentTime)
339	client_p->localClient->lasttime = CurrentTime;
340	if (client_p->localClient->lasttime > client_p->localClient->since)
341	client_p->localClient->since = CurrentTime;
342	ClearPingSent(client_p);
343
344	/* Attempt to parse what we have */
345	parse_client_queued(client_p);
346
347	if (IsDefunct(client_p))
348	return;
349
350	/* Check to make sure we're not flooding */
351	if (!(IsServer(client_p) \|\| IsHandshake(client_p) \|\| IsConnecting(client_p))
352	&& (dbuf_length(&client_p->localClient->buf_recvq) >
353	get_recvq(&client_p->localClient->confs)))
354	{
355	if (!(ConfigFileEntry.no_oper_flood && HasUMode(client_p, UMODE_OPER)))
356	{
357	exit_client(client_p, "Excess Flood");
358	return;
359	}
360	}
361	}
362	#ifdef HAVE_LIBCRYPTO
363	while (length == sizeof(readBuf) \|\| fd->ssl);
364	#else
365	while (length == sizeof(readBuf));
366	#endif
367
368	/* If we get here, we need to register for another COMM_SELECT_READ */
369	comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
370	}
371
372	/*
373	* client_dopacket - copy packet to client buf and parse it
374	* client_p - pointer to client structure for which the buffer data
375	* applies.
376	* buffer - pointr to the buffer containing the newly read data
377	* length - number of valid bytes of data in the buffer
378	*
379	* Note:
380	* It is implicitly assumed that dopacket is called only
381	* with client_p of "local" variation, which contains all the
382	* necessary fields (buffer etc..)
383	*/
384	static void
385	client_dopacket(struct Client client_p, char buffer, size_t length)
386	{
387	/*
388	* Update messages received
389	*/
390	++me.localClient->recv.messages;
391	++client_p->localClient->recv.messages;
392
393	/*
394	* Update bytes received
395	*/
396	client_p->localClient->recv.bytes += length;
397	me.localClient->recv.bytes += length;
398
399	parse(client_p, buffer, buffer + length);
400	}