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 <newclient.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_socket::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_socket::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_socket::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_socket::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_socket::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::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_socket::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_socket::send_packet (const char *buf, int len)
{
  packet sl;

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

void
client_socket::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:	1.21
Committed:	Fri Dec 15 00:14:13 2006 UTC (17 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.20:	+3 -0 lines
Log Message:	- make client_socket accessible to perl - on linux, record rtt and rttvar - who shows rtt/rttvar
#	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 <newclient.h>
39	#include <sproto.h>
40	#include <cstdarg>
41
42	#ifdef __linux__
43	# include <sys/types.h>
44	# include <sys/socket.h>
45	# include <netinet/in.h>
46	# define TCP_HZ 1000 // sorry...
47	# include <netinet/tcp.h>
48	#endif
49
50	// use a really low timeout, as it doesn't cost any bandwidth, and you can
51	// easily die in 20 seconds...
52	#define SOCKET_TIMEOUT1 10
53	#define SOCKET_TIMEOUT2 20
54
55	void
56	client_socket::flush ()
57	{
58	#ifdef __linux__
59	// check time of last ack, and, if too old, kill connection
60	struct tcp_info tcpi;
61	socklen_t len = sizeof (tcpi);
62
63	if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
64	{
65	unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;
66
67	rtt = tcpi.tcpi_rtt;
68	rttvar = tcpi.tcpi_rttvar;
69
70	if (tcpi.tcpi_unacked && SOCKET_TIMEOUT1 * TCP_HZ < diff && diff < 0x80000000UL // ack delayed for 20s
71	&& SOCKET_TIMEOUT2 * TCP_HZ < tcpi.tcpi_last_data_sent) // no data sent for 10s
72	{
73	LOG (llevDebug, "Connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
74	(unsigned) tcpi.tcpi_last_ack_recv, (unsigned) tcpi.tcpi_last_data_sent, (unsigned) tcpi.tcpi_unacked);
75	status = Ns_Dead;
76	}
77	}
78	#endif
79
80	/**
81	* Writes data to socket.
82	*
83	* When the socket is clear to write, and we have backlogged data, this
84	* is called to write it out.
85	*/
86
87	if (!outputbuffer.len \|\| socket_ev.poll () & PE_W)
88	return;
89
90	write_outputbuffer ();
91	}
92
93	void
94	client_socket::write_outputbuffer ()
95	{
96	while (outputbuffer.len)
97	{
98	int res = write (fd, outputbuffer.data + outputbuffer.start,
99	min (outputbuffer.len, SOCKETBUFSIZE - outputbuffer.start));
100
101	if (res > 0)
102	{
103	outputbuffer.start += res;
104	/* wrap back to start of buffer */
105	if (outputbuffer.start == SOCKETBUFSIZE)
106	outputbuffer.start = 0;
107
108	outputbuffer.len -= res;
109	#ifdef CS_LOGSTATS
110	cst_tot.obytes += res;
111	cst_lst.obytes += res;
112	#endif
113	}
114	else if (res == 0)
115	{
116	LOG (llevError, "socket write failed, connection closed.\n");
117	status = Ns_Dead;
118	return;
119	}
120	else if (errno == EINTR)
121	{
122	// just retry
123	}
124	else if (errno == EAGAIN)
125	{
126	// delay till ready
127	socket_ev.poll (socket_ev.poll () \| PE_W);
128	socket_ev.start ();
129	return;
130	}
131	else
132	{
133	LOG (llevError, "socket write failed: %s\n", strerror (errno));
134	status = Ns_Dead;
135	return;
136	}
137	}
138
139	socket_ev.poll (socket_ev.poll () & ~PE_W);
140	}
141
142	/***********************************************************************
143	*
144	* packet functions/utilities
145	*
146	**********************************************************************/
147
148	packet &packet::operator <<(const data &v)
149	{
150	if (room () < v.len)
151	reset ();
152	else
153	{
154	if (v.len)
155	{
156	memcpy (cur, v.ptr, v.len);
157	cur += v.len;
158	}
159	}
160
161	return *this;
162	}
163
164	packet &packet::operator <<(const data8 &v)
165	{
166	unsigned int len = min (v.len, 0x00FF);
167	return *this << uint8 (len) << data (v.ptr, len);
168	}
169
170	packet &packet::operator <<(const data16 &v)
171	{
172	unsigned int len = min (v.len, 0xFFFF);
173	return *this << uint16 (len) << data (v.ptr, len);
174	}
175
176	packet &packet::operator <<(const char *v)
177	{
178	return *this << data (v, strlen (v ? v : 0));
179	}
180
181	void
182	packet::printf (const char *format, ...)
183	{
184	int size = room ();
185
186	va_list ap;
187	va_start (ap, format);
188	int len = vsnprintf ((char *)cur, size, format, ap);
189	va_end (ap);
190
191	if (len >= size)
192	return reset ();
193
194	cur += len;
195	}
196
197	/******************************************************************************
198	*
199	* Start of read routines.
200	*
201	******************************************************************************/
202
203	int
204	client_socket::read_packet ()
205	{
206	for (;;)
207	{
208	if (inbuf_len >= 2)
209	{
210	unsigned int pkt_len = (inbuf [0] << 8) \| inbuf [1];
211
212	if (inbuf_len >= 2 + pkt_len)
213	return pkt_len + 2;
214	}
215
216	int amount = sizeof (inbuf) - inbuf_len;
217
218	if (amount <= 0)
219	{
220	LOG (llevError, "packet too large");//TODO
221	return -1;
222	}
223
224	amount = read (fd, inbuf + inbuf_len, amount);
225
226	if (!amount)
227	{
228	status = Ns_Dead;
229	return -1;
230	}
231	else if (amount < 0)
232	{
233	if (errno != EAGAIN && errno != EINTR)
234	{
235	LOG (llevError, "read error: %s\n", strerror (errno));
236	return -1;
237	}
238
239	return 0;
240	}
241
242	inbuf_len += amount;
243
244	cst_tot.ibytes += amount;
245	cst_lst.ibytes += amount;
246	}
247	}
248
249	void
250	client_socket::skip_packet (int len)
251	{
252	inbuf_len -= len;
253	memmove (inbuf, inbuf + len, inbuf_len);
254	}
255
256	/*******************************************************************************
257	*
258	* Start of write related routines.
259	*
260	******************************************************************************/
261
262	/**
263	* Adds data to a socket buffer for whatever reason.
264	*
265	* ns is the socket we are adding the data to, buf is the start of the
266	* data, and len is the number of bytes to add.
267	*/
268	void
269	client_socket::send (void *buf_, int len)
270	{
271	char buf = (char )buf_;
272	char *pos = buf;
273	int amt = 0;
274
275	if (status == Ns_Dead \|\| !buf)
276	{
277	LOG (llevDebug, "Write_To_Socket called with dead socket\n");
278	return;
279	}
280
281	if ((len + outputbuffer.len) > SOCKETBUFSIZE)
282	{
283	LOG (llevDebug, "Socket on fd %d has overrun internal buffer - marking as dead\n", fd);
284	status = Ns_Dead;
285	return;
286	}
287
288	int avail, end;
289
290	/* data + end is where we start putting the new data. The last byte
291	* currently in use is actually data + end -1
292	*/
293	end = outputbuffer.start + outputbuffer.len;
294	/* The buffer is already in a wrapped state, so adjust end */
295	if (end >= SOCKETBUFSIZE)
296	end -= SOCKETBUFSIZE;
297
298	avail = SOCKETBUFSIZE - end;
299
300	/* We can all fit it behind the current data without wrapping */
301	if (avail >= len)
302	memcpy (outputbuffer.data + end, buf, len);
303	else
304	{
305	memcpy (outputbuffer.data + end, buf, avail);
306	memcpy (outputbuffer.data, buf + avail, len - avail);
307	}
308
309	outputbuffer.len += len;
310	}
311
312	void
313	client_socket::socket_cb (iow &w, int got)
314	{
315	write_outputbuffer ();
316
317	if (!outputbuffer.len)
318	socket_ev.poll (socket_ev.poll () & ~PE_W);
319	}
320
321	/**
322	* Takes a string of data, and writes it out to the socket. A very handy
323	* shortcut function.
324	*/
325	void
326	client_socket::send_packet (packet &sl)
327	{
328	if (status == Ns_Dead)
329	return;
330
331	if (sl.length () >= MAXSOCKBUF)
332	{
333	LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", sl.length ());
334	/* Almost certainly we've overflowed a buffer, so quit now to make
335	* it easier to debug.
336	*/
337	abort ();
338	}
339
340	if (!sl.length ())
341	return;
342
343	assert (sl.hdrlen == 2);
344
345	sl.buf_ [0] = sl.length () >> 8;
346	sl.buf_ [1] = sl.length () ;
347
348	send (sl.buf_, sl.length () + sl.hdrlen);
349	}
350
351	void
352	client_socket::send_packet (const char *buf, int len)
353	{
354	packet sl;
355
356	sl << data (buf, len);
357	send_packet (sl);
358	}
359
360	void
361	client_socket::send_packet (const char *buf)
362	{
363	send_packet (buf, strlen (buf));
364	}
365
366	/******************************************************************************
367	*
368	* statistics logging functions.
369	*
370	******************************************************************************/
371
372	#ifdef CS_LOGSTATS
373
374	/* cst_tot is for the life of the server, cst_last is for the last series of
375	* stats
376	*/
377	CS_Stats cst_tot, cst_lst;
378
379	/**
380	* Writes out the gathered stats. We clear cst_lst.
381	*/
382	void
383	write_cs_stats (void)
384	{
385	time_t now = time (NULL);
386
387	/* If no connections recently, don't both to log anything */
388	if (cst_lst.ibytes == 0 && cst_lst.obytes == 0)
389	return;
390
391	/* CSSTAT is put in so scripts can easily find the line */
392	LOG (llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
393	ctime (&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
394	now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes, cst_lst.max_conn, now - cst_lst.time_start);
395	cst_lst.ibytes = 0;
396	cst_lst.obytes = 0;
397	cst_lst.time_start = now;
398	}
399	#endif
400