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 "hook.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_raw(&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, 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:	3107
Committed:	Thu Mar 6 12:09:42 2014 UTC (11 years, 5 months ago) by michael
Content type:	text/x-csrc
File size:	10587 byte(s)
Log Message:	- Applied dbuf changes as provided by Adam: Refcount dbufs instead of copying the same message to many different buffers.
#	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 "hook.h"
40	#include "send.h"
41	#include "s_misc.h"
42
43	#define READBUF_SIZE 16384
44
45	static char readBuf[READBUF_SIZE];
46	static void client_dopacket(struct Client , char , size_t);
47
48	/* extract_one_line()
49	*
50	* inputs - pointer to a dbuf queue
51	* - pointer to buffer to copy data to
52	* output - length of <buffer>
53	* side effects - one line is copied and removed from the dbuf
54	*/
55	static int
56	extract_one_line(struct dbuf_queue qptr, char buffer)
57	{
58	int line_bytes = 0, empty_bytes = 0, phase = 0;
59	unsigned int idx = 0;
60	dlink_node *ptr = NULL;
61
62	/*
63	* Phase 0: "empty" characters before the line
64	* Phase 1: copying the line
65	* Phase 2: "empty" characters after the line
66	* (delete them as well and free some space in the dbuf)
67	*
68	* Empty characters are CR, LF and space (but, of course, not
69	* in the middle of a line). We try to remove as much of them as we can,
70	* since they simply eat server memory.
71	*
72	* --adx
73	*/
74	DLINK_FOREACH(ptr, qptr->blocks.head)
75	{
76	struct dbuf_block *block = ptr->data;
77
78	if (ptr == qptr->blocks.head)
79	idx = qptr->pos;
80	else
81	idx = 0;
82
83	for (; idx < block->size; ++idx)
84	{
85	char c = block->data[idx];
86
87	if (IsEol(c) \|\| (c == ' ' && phase != 1))
88	{
89	++empty_bytes;
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 LocalUser *lclient_p = client_p->localClient;
128
129	if (IsUnknown(client_p))
130	{
131	int i = 0;
132
133	for (; ;)
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	if (dolen == 0)
144	break;
145
146	client_dopacket(client_p, readBuf, dolen);
147	i++;
148
149	/* if they've dropped out of the unknown state, break and move
150	* to the parsing for their appropriate status. --fl
151	*/
152	if(!IsUnknown(client_p))
153	break;
154	}
155	}
156
157	if (IsServer(client_p) \|\| IsConnecting(client_p) \|\| IsHandshake(client_p))
158	{
159	while (1)
160	{
161	if (IsDefunct(client_p))
162	return;
163	if ((dolen = extract_one_line(&lclient_p->buf_recvq,
164	readBuf)) == 0)
165	break;
166	client_dopacket(client_p, readBuf, dolen);
167	}
168	}
169	else if (IsClient(client_p))
170	{
171	if (ConfigFileEntry.no_oper_flood && (HasUMode(client_p, UMODE_OPER) \|\| IsCanFlood(client_p)))
172	{
173	if (ConfigFileEntry.true_no_oper_flood)
174	checkflood = -1;
175	else
176	checkflood = 0;
177	}
178
179	/*
180	* Handle flood protection here - if we exceed our flood limit on
181	* messages in this loop, we simply drop out of the loop prematurely.
182	* -- adrian
183	*/
184	for (; ;)
185	{
186	if (IsDefunct(client_p))
187	break;
188
189	/* This flood protection works as follows:
190	*
191	* A client is given allow_read lines to send to the server. Every
192	* time a line is parsed, sent_parsed is increased. sent_parsed
193	* is decreased by 1 every time flood_recalc is called.
194	*
195	* Thus a client can 'burst' allow_read lines to the server, any
196	* excess lines will be parsed one per flood_recalc() call.
197	*
198	* Therefore a client will be penalised more if they keep flooding,
199	* as sent_parsed will always hover around the allow_read limit
200	* and no 'bursts' will be permitted.
201	*/
202	if (checkflood > 0)
203	{
204	if(lclient_p->sent_parsed >= lclient_p->allow_read)
205	break;
206	}
207
208	/* allow opers 4 times the amount of messages as users. why 4?
209	* why not. :) --fl_
210	*/
211	else if (lclient_p->sent_parsed >= (4 * lclient_p->allow_read) &&
212	checkflood != -1)
213	break;
214
215	dolen = extract_one_line(&lclient_p->buf_recvq, readBuf);
216	if (dolen == 0)
217	break;
218
219	client_dopacket(client_p, readBuf, dolen);
220	lclient_p->sent_parsed++;
221	}
222	}
223	}
224
225	/* flood_endgrace()
226	*
227	* marks the end of the clients grace period
228	*/
229	void
230	flood_endgrace(struct Client *client_p)
231	{
232	SetFloodDone(client_p);
233
234	/* Drop their flood limit back down */
235	client_p->localClient->allow_read = MAX_FLOOD;
236
237	/* sent_parsed could be way over MAX_FLOOD but under MAX_FLOOD_BURST,
238	* so reset it.
239	*/
240	client_p->localClient->sent_parsed = 0;
241	}
242
243	/*
244	* flood_recalc
245	*
246	* recalculate the number of allowed flood lines. this should be called
247	* once a second on any given client. We then attempt to flush some data.
248	*/
249	void
250	flood_recalc(fde_t fd, void data)
251	{
252	struct Client *client_p = data;
253	struct LocalUser *lclient_p = client_p->localClient;
254
255	/* allow a bursting client their allocation per second, allow
256	* a client whos flooding an extra 2 per second
257	*/
258	if (IsFloodDone(client_p))
259	lclient_p->sent_parsed -= 2;
260	else
261	lclient_p->sent_parsed = 0;
262
263	if (lclient_p->sent_parsed < 0)
264	lclient_p->sent_parsed = 0;
265
266	parse_client_queued(client_p);
267
268	/* And now, try flushing .. */
269	if (!IsDead(client_p))
270	{
271	/* and finally, reset the flood check */
272	comm_setflush(fd, 1000, flood_recalc, client_p);
273	}
274	}
275
276	/*
277	* read_packet - Read a 'packet' of data from a connection and process it.
278	*/
279	void
280	read_packet(fde_t fd, void data)
281	{
282	struct Client *client_p = data;
283	int length = 0;
284
285	if (IsDefunct(client_p))
286	return;
287
288	/*
289	* Read some data. We used to do anti-flood protection here, but
290	* I personally think it makes the code too hairy to make sane.
291	* -- adrian
292	*/
293	do
294	{
295	#ifdef HAVE_LIBCRYPTO
296	if (fd->ssl)
297	{
298	length = SSL_read(fd->ssl, readBuf, READBUF_SIZE);
299
300	/* translate openssl error codes, sigh */
301	if (length < 0)
302	switch (SSL_get_error(fd->ssl, length))
303	{
304	case SSL_ERROR_WANT_WRITE:
305	comm_setselect(fd, COMM_SELECT_WRITE, (PF *)sendq_unblocked, client_p, 0);
306	return;
307	case SSL_ERROR_WANT_READ:
308	errno = EWOULDBLOCK;
309	case SSL_ERROR_SYSCALL:
310	break;
311	case SSL_ERROR_SSL:
312	if (errno == EAGAIN)
313	break;
314	default:
315	length = errno = 0;
316	}
317	}
318	else
319	#endif
320	{
321	length = recv(fd->fd, readBuf, READBUF_SIZE, 0);
322	}
323
324	if (length <= 0)
325	{
326	/*
327	* If true, then we can recover from this error. Just jump out of
328	* the loop and re-register a new io-request.
329	*/
330	if (length < 0 && ignoreErrno(errno))
331	break;
332
333	dead_link_on_read(client_p, length);
334	return;
335	}
336
337	dbuf_put_raw(&client_p->localClient->buf_recvq, readBuf, length);
338
339	if (client_p->localClient->lasttime < CurrentTime)
340	client_p->localClient->lasttime = CurrentTime;
341	if (client_p->localClient->lasttime > client_p->localClient->since)
342	client_p->localClient->since = CurrentTime;
343	ClearPingSent(client_p);
344
345	/* Attempt to parse what we have */
346	parse_client_queued(client_p);
347
348	if (IsDefunct(client_p))
349	return;
350
351	/* Check to make sure we're not flooding */
352	if (!(IsServer(client_p) \|\| IsHandshake(client_p) \|\| IsConnecting(client_p))
353	&& (dbuf_length(&client_p->localClient->buf_recvq) >
354	get_recvq(&client_p->localClient->confs)))
355	{
356	if (!(ConfigFileEntry.no_oper_flood && HasUMode(client_p, UMODE_OPER)))
357	{
358	exit_client(client_p, client_p, "Excess Flood");
359	return;
360	}
361	}
362	}
363	#ifdef HAVE_LIBCRYPTO
364	while (length == sizeof(readBuf) \|\| fd->ssl);
365	#else
366	while (length == sizeof(readBuf));
367	#endif
368
369	/* If we get here, we need to register for another COMM_SELECT_READ */
370	comm_setselect(fd, COMM_SELECT_READ, read_packet, client_p, 0);
371	}
372
373	/*
374	* client_dopacket - copy packet to client buf and parse it
375	* client_p - pointer to client structure for which the buffer data
376	* applies.
377	* buffer - pointr to the buffer containing the newly read data
378	* length - number of valid bytes of data in the buffer
379	*
380	* Note:
381	* It is implicitly assumed that dopacket is called only
382	* with client_p of "local" variation, which contains all the
383	* necessary fields (buffer etc..)
384	*/
385	static void
386	client_dopacket(struct Client client_p, char buffer, size_t length)
387	{
388	/*
389	* Update messages received
390	*/
391	++me.localClient->recv.messages;
392	++client_p->localClient->recv.messages;
393
394	/*
395	* Update bytes received
396	*/
397	client_p->localClient->recv.bytes += length;
398	me.localClient->recv.bytes += length;
399
400	parse(client_p, buffer, buffer + length);
401	}