server/socket/lowlevel.C

/*
    CrossFire, A Multiplayer game for X-windows

    Copyright (C) 1992 Frank Tore Johansen

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

    The author can be reached via e-mail to mark@pyramid.com
*/

/**
 * \file
 * Low-level socket-related functions.
 *
 * \date 2003-12-02
 *
 * Contains some base functions that both the client and server
 * can use.  As such, depending what we are being compiled for will
 * determine what we can include.  the client is designed have
 * CFCLIENT defined as part of its compile flags.
 */

using namespace std;

#include <global.h>
#include <sproto.h>
#include <cstdarg>

#ifdef __linux__
# include <sys/types.h>
# include <sys/socket.h>
# include <netinet/in.h>
# define TCP_HZ 1000            // sorry...
# include <netinet/tcp.h>
#endif

// use a really low timeout, as it doesn't cost any bandwidth, and you can
// easily die in 20 seconds...
#define SOCKET_TIMEOUT1 10
#define SOCKET_TIMEOUT2 20

void
client::flush ()
{
#ifdef __linux__
  // check time of last ack, and, if too old, kill connection
  struct tcp_info tcpi;
  socklen_t len = sizeof (tcpi);

  if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
    {
      unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;

      rtt    = tcpi.tcpi_rtt;
      rttvar = tcpi.tcpi_rttvar;

      if (tcpi.tcpi_unacked && SOCKET_TIMEOUT1 * TCP_HZ < diff && diff < 0x80000000UL   // ack delayed for 20s
          && SOCKET_TIMEOUT2 * TCP_HZ < tcpi.tcpi_last_data_sent)       // no data sent for 10s
        {
          LOG (llevDebug, "Connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
               (unsigned) tcpi.tcpi_last_ack_recv, (unsigned) tcpi.tcpi_last_data_sent, (unsigned) tcpi.tcpi_unacked);
          status = Ns_Dead;
        }
    }
#endif

  /**
   * Writes data to socket.
   *
   * When the socket is clear to write, and we have backlogged data, this
   * is called to write it out.
   */

  if (!outputbuffer.len || socket_ev.poll () & PE_W)
    return;

  write_outputbuffer ();
}

void
client::write_outputbuffer ()
{
  while (outputbuffer.len)
    {
      int res = write (fd, outputbuffer.data + outputbuffer.start,
                       min (outputbuffer.len, SOCKETBUFSIZE - outputbuffer.start));

      if (res > 0)
        {
          outputbuffer.start += res;
          /* wrap back to start of buffer */
          if (outputbuffer.start == SOCKETBUFSIZE)
            outputbuffer.start = 0;

          outputbuffer.len -= res;
#ifdef CS_LOGSTATS
          cst_tot.obytes += res;
          cst_lst.obytes += res;
#endif
        }
      else if (res == 0)
        {
          LOG (llevError, "socket write failed, connection closed.\n");
          status = Ns_Dead;
          return;
        }
      else if (errno == EINTR)
        {
          // just retry
        }
      else if (errno == EAGAIN)
        {
          // delay till ready
          socket_ev.poll (socket_ev.poll () | PE_W);
          socket_ev.start ();
          return;
        }
      else
        {
          LOG (llevError, "socket write failed: %s\n", strerror (errno));
          status = Ns_Dead;
          return;
        }
    }

  socket_ev.poll (socket_ev.poll () & ~PE_W);
}

/***********************************************************************
 *
 * packet functions/utilities
 *
 **********************************************************************/

packet &packet::operator <<(const data   &v)
{
  if (room () < v.len)
    reset ();
  else
    {
      if (v.len)
        {
          memcpy (cur, v.ptr, v.len);
          cur += v.len;
        }
    }

  return *this;
}

packet &packet::operator <<(const data8  &v)
{
  unsigned int len = min (v.len, 0x00FF);
  return *this << uint8  (len) << data (v.ptr, len);
}

packet &packet::operator <<(const data16 &v)
{
  unsigned int len = min (v.len, 0xFFFF);
  return *this << uint16 (len) << data (v.ptr, len);
}

packet &packet::operator <<(const char *v)
{
  return *this << data (v, strlen (v ? v : 0));
}

void
packet::printf (const char *format, ...)
{
  int size = room ();

  va_list ap;
  va_start (ap, format);
  int len = vsnprintf ((char *)cur, size, format, ap);
  va_end (ap);

  if (len >= size)
    return reset ();

  cur += len;
}

/******************************************************************************
 *
 * Start of read routines.
 *
 ******************************************************************************/

int
client::read_packet ()
{
  for (;;)
    {
      if (inbuf_len >= 2)
        {
          unsigned int pkt_len = (inbuf [0] << 8) | inbuf [1];

          if (inbuf_len >= 2 + pkt_len)
            return  pkt_len + 2;
        }

      int amount = sizeof (inbuf) - inbuf_len;

      if (amount <= 0)
        {
          LOG (llevError, "packet too large");//TODO
          return -1;
        }

      amount = read (fd, inbuf + inbuf_len, amount);

      if (!amount)
        {
          status = Ns_Dead;
          return -1;
        }
      else if (amount < 0)
        {
          if (errno != EAGAIN && errno != EINTR)
            {
              LOG (llevError, "read error: %s\n", strerror (errno));
              return -1;
            }

          return 0;
        }

      inbuf_len += amount;

      cst_tot.ibytes += amount;
      cst_lst.ibytes += amount;
    }
}

void
client::skip_packet (int len)
{
  inbuf_len -= len;
  memmove (inbuf, inbuf + len, inbuf_len);
}

/*******************************************************************************
 *
 * Start of write related routines.
 *
 ******************************************************************************/

/**
 * Adds data to a socket buffer for whatever reason.
 *
 * ns is the socket we are adding the data to, buf is the start of the
 * data, and len is the number of bytes to add.
 */
void
client::send (void *buf_, int len)
{
  char *buf = (char *)buf_;
  char *pos = buf;
  int amt = 0;

  if (status == Ns_Dead || !buf)
    {
      LOG (llevDebug, "Write_To_Socket called with dead socket\n");
      return;
    }

  if ((len + outputbuffer.len) > SOCKETBUFSIZE)
    {
      LOG (llevDebug, "Socket on fd %d has overrun internal buffer - marking as dead\n", fd);
      status = Ns_Dead;
      return;
    }

  int avail, end;

  /* data + end is where we start putting the new data.  The last byte
   * currently in use is actually data + end -1
   */
  end = outputbuffer.start + outputbuffer.len;
  /* The buffer is already in a wrapped state, so adjust end */
  if (end >= SOCKETBUFSIZE)
    end -= SOCKETBUFSIZE;

  avail = SOCKETBUFSIZE - end;

  /* We can all fit it behind the current data without wrapping */
  if (avail >= len)
    memcpy (outputbuffer.data + end, buf, len);
  else
    {
      memcpy (outputbuffer.data + end, buf, avail);
      memcpy (outputbuffer.data, buf + avail, len - avail);
    }

  outputbuffer.len += len;
}

void
client::socket_cb (iow &w, int got)
{
  write_outputbuffer ();

  if (!outputbuffer.len)
    socket_ev.poll (socket_ev.poll () & ~PE_W);
}

/**
 * Takes a string of data, and writes it out to the socket. A very handy
 * shortcut function.
 */
void
client::send_packet (packet &sl)
{
  if (status == Ns_Dead)
    return;

  if (sl.length () >= MAXSOCKBUF)
    {
      LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", sl.length ());
      /* Almost certainly we've overflowed a buffer, so quit now to make
       * it easier to debug.
       */
      abort ();
    }

  if (!sl.length ())
    return;

  assert (sl.hdrlen == 2);

  sl.buf_ [0] = sl.length () >> 8;
  sl.buf_ [1] = sl.length ()     ;

  send (sl.buf_, sl.length () + sl.hdrlen);
}

void
client::send_packet (const char *buf, int len)
{
  packet sl;

  sl << data (buf, len);
  send_packet (sl);
}

void
client::send_packet (const char *buf)
{
  send_packet (buf, strlen (buf));
}

/******************************************************************************
 *
 * statistics logging functions.
 *
 ******************************************************************************/

#ifdef CS_LOGSTATS

/* cst_tot is for the life of the server, cst_last is for the last series of
 * stats
 */
CS_Stats cst_tot, cst_lst;

/**
 * Writes out the gathered stats.  We clear cst_lst.
 */
void
write_cs_stats (void)
{
  time_t now = time (NULL);

  /* If no connections recently, don't both to log anything */
  if (cst_lst.ibytes == 0 && cst_lst.obytes == 0)
    return;

  /* CSSTAT is put in so scripts can easily find the line */
  LOG (llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
       ctime (&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
       now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes, cst_lst.max_conn, now - cst_lst.time_start);
  cst_lst.ibytes = 0;
  cst_lst.obytes = 0;
  cst_lst.time_start = now;
}
#endif

Revision:	1.22
Committed:	Fri Dec 15 19:59:20 2006 UTC (17 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.21:	+9 -10 lines
Log Message:	the rename for sanity campaign hits you died - renamed stuff - partially updated copyrights - some cleanups
#	Content
1	/*
2	CrossFire, A Multiplayer game for X-windows
3
4	Copyright (C) 1992 Frank Tore Johansen
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., 675 Mass Ave, Cambridge, MA 02139, USA.
19
20	The author can be reached via e-mail to mark@pyramid.com
21	*/
22
23	/**
24	* \file
25	* Low-level socket-related functions.
26	*
27	* \date 2003-12-02
28	*
29	* Contains some base functions that both the client and server
30	* can use. As such, depending what we are being compiled for will
31	* determine what we can include. the client is designed have
32	* CFCLIENT defined as part of its compile flags.
33	*/
34
35	using namespace std;
36
37	#include <global.h>
38	#include <sproto.h>
39	#include <cstdarg>
40
41	#ifdef __linux__
42	# include <sys/types.h>
43	# include <sys/socket.h>
44	# include <netinet/in.h>
45	# define TCP_HZ 1000 // sorry...
46	# include <netinet/tcp.h>
47	#endif
48
49	// use a really low timeout, as it doesn't cost any bandwidth, and you can
50	// easily die in 20 seconds...
51	#define SOCKET_TIMEOUT1 10
52	#define SOCKET_TIMEOUT2 20
53
54	void
55	client::flush ()
56	{
57	#ifdef __linux__
58	// check time of last ack, and, if too old, kill connection
59	struct tcp_info tcpi;
60	socklen_t len = sizeof (tcpi);
61
62	if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
63	{
64	unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;
65
66	rtt = tcpi.tcpi_rtt;
67	rttvar = tcpi.tcpi_rttvar;
68
69	if (tcpi.tcpi_unacked && SOCKET_TIMEOUT1 * TCP_HZ < diff && diff < 0x80000000UL // ack delayed for 20s
70	&& SOCKET_TIMEOUT2 * TCP_HZ < tcpi.tcpi_last_data_sent) // no data sent for 10s
71	{
72	LOG (llevDebug, "Connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
73	(unsigned) tcpi.tcpi_last_ack_recv, (unsigned) tcpi.tcpi_last_data_sent, (unsigned) tcpi.tcpi_unacked);
74	status = Ns_Dead;
75	}
76	}
77	#endif
78
79	/**
80	* Writes data to socket.
81	*
82	* When the socket is clear to write, and we have backlogged data, this
83	* is called to write it out.
84	*/
85
86	if (!outputbuffer.len \|\| socket_ev.poll () & PE_W)
87	return;
88
89	write_outputbuffer ();
90	}
91
92	void
93	client::write_outputbuffer ()
94	{
95	while (outputbuffer.len)
96	{
97	int res = write (fd, outputbuffer.data + outputbuffer.start,
98	min (outputbuffer.len, SOCKETBUFSIZE - outputbuffer.start));
99
100	if (res > 0)
101	{
102	outputbuffer.start += res;
103	/* wrap back to start of buffer */
104	if (outputbuffer.start == SOCKETBUFSIZE)
105	outputbuffer.start = 0;
106
107	outputbuffer.len -= res;
108	#ifdef CS_LOGSTATS
109	cst_tot.obytes += res;
110	cst_lst.obytes += res;
111	#endif
112	}
113	else if (res == 0)
114	{
115	LOG (llevError, "socket write failed, connection closed.\n");
116	status = Ns_Dead;
117	return;
118	}
119	else if (errno == EINTR)
120	{
121	// just retry
122	}
123	else if (errno == EAGAIN)
124	{
125	// delay till ready
126	socket_ev.poll (socket_ev.poll () \| PE_W);
127	socket_ev.start ();
128	return;
129	}
130	else
131	{
132	LOG (llevError, "socket write failed: %s\n", strerror (errno));
133	status = Ns_Dead;
134	return;
135	}
136	}
137
138	socket_ev.poll (socket_ev.poll () & ~PE_W);
139	}
140
141	/***********************************************************************
142	*
143	* packet functions/utilities
144	*
145	**********************************************************************/
146
147	packet &packet::operator <<(const data &v)
148	{
149	if (room () < v.len)
150	reset ();
151	else
152	{
153	if (v.len)
154	{
155	memcpy (cur, v.ptr, v.len);
156	cur += v.len;
157	}
158	}
159
160	return *this;
161	}
162
163	packet &packet::operator <<(const data8 &v)
164	{
165	unsigned int len = min (v.len, 0x00FF);
166	return *this << uint8 (len) << data (v.ptr, len);
167	}
168
169	packet &packet::operator <<(const data16 &v)
170	{
171	unsigned int len = min (v.len, 0xFFFF);
172	return *this << uint16 (len) << data (v.ptr, len);
173	}
174
175	packet &packet::operator <<(const char *v)
176	{
177	return *this << data (v, strlen (v ? v : 0));
178	}
179
180	void
181	packet::printf (const char *format, ...)
182	{
183	int size = room ();
184
185	va_list ap;
186	va_start (ap, format);
187	int len = vsnprintf ((char *)cur, size, format, ap);
188	va_end (ap);
189
190	if (len >= size)
191	return reset ();
192
193	cur += len;
194	}
195
196	/******************************************************************************
197	*
198	* Start of read routines.
199	*
200	******************************************************************************/
201
202	int
203	client::read_packet ()
204	{
205	for (;;)
206	{
207	if (inbuf_len >= 2)
208	{
209	unsigned int pkt_len = (inbuf [0] << 8) \| inbuf [1];
210
211	if (inbuf_len >= 2 + pkt_len)
212	return pkt_len + 2;
213	}
214
215	int amount = sizeof (inbuf) - inbuf_len;
216
217	if (amount <= 0)
218	{
219	LOG (llevError, "packet too large");//TODO
220	return -1;
221	}
222
223	amount = read (fd, inbuf + inbuf_len, amount);
224
225	if (!amount)
226	{
227	status = Ns_Dead;
228	return -1;
229	}
230	else if (amount < 0)
231	{
232	if (errno != EAGAIN && errno != EINTR)
233	{
234	LOG (llevError, "read error: %s\n", strerror (errno));
235	return -1;
236	}
237
238	return 0;
239	}
240
241	inbuf_len += amount;
242
243	cst_tot.ibytes += amount;
244	cst_lst.ibytes += amount;
245	}
246	}
247
248	void
249	client::skip_packet (int len)
250	{
251	inbuf_len -= len;
252	memmove (inbuf, inbuf + len, inbuf_len);
253	}
254
255	/*******************************************************************************
256	*
257	* Start of write related routines.
258	*
259	******************************************************************************/
260
261	/**
262	* Adds data to a socket buffer for whatever reason.
263	*
264	* ns is the socket we are adding the data to, buf is the start of the
265	* data, and len is the number of bytes to add.
266	*/
267	void
268	client::send (void *buf_, int len)
269	{
270	char buf = (char )buf_;
271	char *pos = buf;
272	int amt = 0;
273
274	if (status == Ns_Dead \|\| !buf)
275	{
276	LOG (llevDebug, "Write_To_Socket called with dead socket\n");
277	return;
278	}
279
280	if ((len + outputbuffer.len) > SOCKETBUFSIZE)
281	{
282	LOG (llevDebug, "Socket on fd %d has overrun internal buffer - marking as dead\n", fd);
283	status = Ns_Dead;
284	return;
285	}
286
287	int avail, end;
288
289	/* data + end is where we start putting the new data. The last byte
290	* currently in use is actually data + end -1
291	*/
292	end = outputbuffer.start + outputbuffer.len;
293	/* The buffer is already in a wrapped state, so adjust end */
294	if (end >= SOCKETBUFSIZE)
295	end -= SOCKETBUFSIZE;
296
297	avail = SOCKETBUFSIZE - end;
298
299	/* We can all fit it behind the current data without wrapping */
300	if (avail >= len)
301	memcpy (outputbuffer.data + end, buf, len);
302	else
303	{
304	memcpy (outputbuffer.data + end, buf, avail);
305	memcpy (outputbuffer.data, buf + avail, len - avail);
306	}
307
308	outputbuffer.len += len;
309	}
310
311	void
312	client::socket_cb (iow &w, int got)
313	{
314	write_outputbuffer ();
315
316	if (!outputbuffer.len)
317	socket_ev.poll (socket_ev.poll () & ~PE_W);
318	}
319
320	/**
321	* Takes a string of data, and writes it out to the socket. A very handy
322	* shortcut function.
323	*/
324	void
325	client::send_packet (packet &sl)
326	{
327	if (status == Ns_Dead)
328	return;
329
330	if (sl.length () >= MAXSOCKBUF)
331	{
332	LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", sl.length ());
333	/* Almost certainly we've overflowed a buffer, so quit now to make
334	* it easier to debug.
335	*/
336	abort ();
337	}
338
339	if (!sl.length ())
340	return;
341
342	assert (sl.hdrlen == 2);
343
344	sl.buf_ [0] = sl.length () >> 8;
345	sl.buf_ [1] = sl.length () ;
346
347	send (sl.buf_, sl.length () + sl.hdrlen);
348	}
349
350	void
351	client::send_packet (const char *buf, int len)
352	{
353	packet sl;
354
355	sl << data (buf, len);
356	send_packet (sl);
357	}
358
359	void
360	client::send_packet (const char *buf)
361	{
362	send_packet (buf, strlen (buf));
363	}
364
365	/******************************************************************************
366	*
367	* statistics logging functions.
368	*
369	******************************************************************************/
370
371	#ifdef CS_LOGSTATS
372
373	/* cst_tot is for the life of the server, cst_last is for the last series of
374	* stats
375	*/
376	CS_Stats cst_tot, cst_lst;
377
378	/**
379	* Writes out the gathered stats. We clear cst_lst.
380	*/
381	void
382	write_cs_stats (void)
383	{
384	time_t now = time (NULL);
385
386	/* If no connections recently, don't both to log anything */
387	if (cst_lst.ibytes == 0 && cst_lst.obytes == 0)
388	return;
389
390	/* CSSTAT is put in so scripts can easily find the line */
391	LOG (llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
392	ctime (&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
393	now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes, cst_lst.max_conn, now - cst_lst.time_start);
394	cst_lst.ibytes = 0;
395	cst_lst.obytes = 0;
396	cst_lst.time_start = now;
397	}
398	#endif
399