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;

      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:	1.20
Committed:	Thu Dec 14 21:46:34 2006 UTC (19 years, 9 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.19:	+89 -153 lines
Log Message:	- write() is now independent of server ticks and will be done immediately - get rid of CORK hack, it is no longer necessary
#	User	Rev	Content
1	elmex	1.1	/*
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	root	1.11	#include <cstdarg>
41	elmex	1.1
42			#ifdef __linux__
43			# include <sys/types.h>
44			# include <sys/socket.h>
45			# include <netinet/in.h>
46	root	1.5	# define TCP_HZ 1000 // sorry...
47	elmex	1.1	# 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	root	1.5	void
56	root	1.20	client_socket::flush ()
57	elmex	1.1	{
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	root	1.20	if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
64	elmex	1.1	{
65			unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;
66
67	root	1.5	if (tcpi.tcpi_unacked && SOCKET_TIMEOUT1 * TCP_HZ < diff && diff < 0x80000000UL // ack delayed for 20s
68			&& SOCKET_TIMEOUT2 * TCP_HZ < tcpi.tcpi_last_data_sent) // no data sent for 10s
69	elmex	1.1	{
70	root	1.20	LOG (llevDebug, "Connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
71	root	1.5	(unsigned) tcpi.tcpi_last_ack_recv, (unsigned) tcpi.tcpi_last_data_sent, (unsigned) tcpi.tcpi_unacked);
72	root	1.20	status = Ns_Dead;
73	elmex	1.1	}
74			}
75	root	1.20	#endif
76
77			/**
78			* Writes data to socket.
79			*
80			* When the socket is clear to write, and we have backlogged data, this
81			* is called to write it out.
82			*/
83
84			if (!outputbuffer.len \|\| socket_ev.poll () & PE_W)
85			return;
86
87			write_outputbuffer ();
88			}
89	elmex	1.1
90	root	1.20	void
91			client_socket::write_outputbuffer ()
92			{
93			while (outputbuffer.len)
94			{
95			int res = write (fd, outputbuffer.data + outputbuffer.start,
96			min (outputbuffer.len, SOCKETBUFSIZE - outputbuffer.start));
97	root	1.5
98	root	1.20	if (res > 0)
99			{
100			outputbuffer.start += res;
101			/* wrap back to start of buffer */
102			if (outputbuffer.start == SOCKETBUFSIZE)
103			outputbuffer.start = 0;
104
105			outputbuffer.len -= res;
106			#ifdef CS_LOGSTATS
107			cst_tot.obytes += res;
108			cst_lst.obytes += res;
109	elmex	1.1	#endif
110	root	1.20	}
111			else if (res == 0)
112			{
113			LOG (llevError, "socket write failed, connection closed.\n");
114			status = Ns_Dead;
115			return;
116			}
117			else if (errno == EINTR)
118			{
119			// just retry
120			}
121			else if (errno == EAGAIN)
122			{
123			// delay till ready
124			socket_ev.poll (socket_ev.poll () \| PE_W);
125			socket_ev.start ();
126			return;
127			}
128			else
129			{
130			LOG (llevError, "socket write failed: %s\n", strerror (errno));
131			status = Ns_Dead;
132			return;
133			}
134			}
135
136			socket_ev.poll (socket_ev.poll () & ~PE_W);
137	elmex	1.1	}
138
139			/***********************************************************************
140			*
141	root	1.14	* packet functions/utilities
142	elmex	1.1	*
143			**********************************************************************/
144
145	root	1.14	packet &packet::operator <<(const data &v)
146	elmex	1.1	{
147	root	1.15	if (room () < v.len)
148			reset ();
149			else
150	root	1.11	{
151	root	1.15	if (v.len)
152			{
153			memcpy (cur, v.ptr, v.len);
154			cur += v.len;
155			}
156	root	1.11	}
157	root	1.9
158	root	1.11	return *this;
159			}
160	root	1.9
161	root	1.14	packet &packet::operator <<(const data8 &v)
162	root	1.11	{
163			unsigned int len = min (v.len, 0x00FF);
164			return *this << uint8 (len) << data (v.ptr, len);
165	elmex	1.1	}
166
167	root	1.14	packet &packet::operator <<(const data16 &v)
168	elmex	1.1	{
169	root	1.11	unsigned int len = min (v.len, 0xFFFF);
170			return *this << uint16 (len) << data (v.ptr, len);
171			}
172	root	1.9
173	root	1.14	packet &packet::operator <<(const char *v)
174	root	1.11	{
175			return *this << data (v, strlen (v ? v : 0));
176	elmex	1.1	}
177
178	root	1.11	void
179	root	1.14	packet::printf (const char *format, ...)
180	root	1.10	{
181	root	1.15	int size = room ();
182
183	root	1.11	va_list ap;
184			va_start (ap, format);
185	root	1.15	int len = vsnprintf ((char *)cur, size, format, ap);
186			va_end (ap);
187	root	1.11
188	root	1.15	if (len >= size)
189			return reset ();
190	root	1.10
191	root	1.15	cur += len;
192	root	1.10	}
193
194	elmex	1.1	/******************************************************************************
195			*
196			* Start of read routines.
197			*
198			******************************************************************************/
199
200	root	1.5	int
201	root	1.16	client_socket::read_packet ()
202	elmex	1.1	{
203	root	1.12	for (;;)
204	root	1.5	{
205	root	1.12	if (inbuf_len >= 2)
206	root	1.5	{
207	root	1.12	unsigned int pkt_len = (inbuf [0] << 8) \| inbuf [1];
208
209			if (inbuf_len >= 2 + pkt_len)
210			return pkt_len + 2;
211	root	1.5	}
212	pippijn	1.8
213	root	1.12	int amount = sizeof (inbuf) - inbuf_len;
214
215			if (amount <= 0)
216	root	1.5	{
217	root	1.12	LOG (llevError, "packet too large");//TODO
218			return -1;
219	root	1.3	}
220	elmex	1.1
221	root	1.12	amount = read (fd, inbuf + inbuf_len, amount);
222
223			if (!amount)
224	root	1.5	{
225	root	1.12	status = Ns_Dead;
226			return -1;
227	root	1.5	}
228	root	1.12	else if (amount < 0)
229	root	1.5	{
230	root	1.12	if (errno != EAGAIN && errno != EINTR)
231	root	1.5	{
232	root	1.20	LOG (llevError, "read error: %s\n", strerror (errno));
233	root	1.12	return -1;
234	root	1.3	}
235	root	1.12
236			return 0;
237	root	1.3	}
238	root	1.12
239			inbuf_len += amount;
240
241			cst_tot.ibytes += amount;
242			cst_lst.ibytes += amount;
243	root	1.5	}
244	root	1.12	}
245
246			void
247	root	1.16	client_socket::skip_packet (int len)
248	root	1.12	{
249			inbuf_len -= len;
250			memmove (inbuf, inbuf + len, inbuf_len);
251	elmex	1.1	}
252
253			/*******************************************************************************
254			*
255			* Start of write related routines.
256			*
257			******************************************************************************/
258
259			/**
260			* Adds data to a socket buffer for whatever reason.
261			*
262			* ns is the socket we are adding the data to, buf is the start of the
263			* data, and len is the number of bytes to add.
264			*/
265	root	1.20	void
266			client_socket::send (void *buf_, int len)
267			{
268			char buf = (char )buf_;
269			char *pos = buf;
270			int amt = 0;
271	elmex	1.1
272	root	1.20	if (status == Ns_Dead \|\| !buf)
273			{
274			LOG (llevDebug, "Write_To_Socket called with dead socket\n");
275			return;
276			}
277	elmex	1.1
278	root	1.20	if ((len + outputbuffer.len) > SOCKETBUFSIZE)
279	root	1.5	{
280	root	1.20	LOG (llevDebug, "Socket on fd %d has overrun internal buffer - marking as dead\n", fd);
281			status = Ns_Dead;
282	root	1.5	return;
283			}
284
285	root	1.20	int avail, end;
286
287	root	1.5	/* data + end is where we start putting the new data. The last byte
288			* currently in use is actually data + end -1
289			*/
290	root	1.20	end = outputbuffer.start + outputbuffer.len;
291	root	1.5	/* The buffer is already in a wrapped state, so adjust end */
292			if (end >= SOCKETBUFSIZE)
293			end -= SOCKETBUFSIZE;
294	root	1.7
295	root	1.5	avail = SOCKETBUFSIZE - end;
296	elmex	1.1
297	root	1.5	/* We can all fit it behind the current data without wrapping */
298			if (avail >= len)
299	root	1.20	memcpy (outputbuffer.data + end, buf, len);
300	root	1.5	else
301			{
302	root	1.20	memcpy (outputbuffer.data + end, buf, avail);
303			memcpy (outputbuffer.data, buf + avail, len - avail);
304	elmex	1.1	}
305	root	1.7
306	root	1.20	outputbuffer.len += len;
307	elmex	1.1	}
308
309	root	1.5	void
310	root	1.20	client_socket::socket_cb (iow &w, int got)
311	elmex	1.1	{
312	root	1.20	write_outputbuffer ();
313	elmex	1.1
314	root	1.20	if (!outputbuffer.len)
315			socket_ev.poll (socket_ev.poll () & ~PE_W);
316	root	1.19	}
317
318	elmex	1.1	/**
319			* Takes a string of data, and writes it out to the socket. A very handy
320			* shortcut function.
321			*/
322	root	1.13	void
323	root	1.16	client_socket::send_packet (packet &sl)
324	root	1.13	{
325	root	1.19	if (status == Ns_Dead)
326			return;
327
328			if (sl.length () >= MAXSOCKBUF)
329			{
330			LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", sl.length ());
331			/* Almost certainly we've overflowed a buffer, so quit now to make
332			* it easier to debug.
333			*/
334			abort ();
335			}
336
337			if (!sl.length ())
338			return;
339
340			assert (sl.hdrlen == 2);
341
342			sl.buf_ [0] = sl.length () >> 8;
343			sl.buf_ [1] = sl.length () ;
344
345			send (sl.buf_, sl.length () + sl.hdrlen);
346	root	1.13	}
347
348	root	1.5	void
349	root	1.16	client_socket::send_packet (const char *buf, int len)
350	elmex	1.1	{
351	root	1.14	packet sl;
352	elmex	1.1
353	root	1.13	sl << data (buf, len);
354			send_packet (sl);
355	elmex	1.1	}
356
357	root	1.13	void
358	root	1.16	client_socket::send_packet (const char *buf)
359	root	1.13	{
360			send_packet (buf, strlen (buf));
361			}
362	elmex	1.1
363			/******************************************************************************
364			*
365			* statistics logging functions.
366			*
367			******************************************************************************/
368
369			#ifdef CS_LOGSTATS
370	root	1.5
371	elmex	1.1	/* cst_tot is for the life of the server, cst_last is for the last series of
372			* stats
373			*/
374			CS_Stats cst_tot, cst_lst;
375
376			/**
377			* Writes out the gathered stats. We clear cst_lst.
378			*/
379	root	1.5	void
380			write_cs_stats (void)
381	elmex	1.1	{
382	root	1.5	time_t now = time (NULL);
383	elmex	1.1
384	root	1.5	/* If no connections recently, don't both to log anything */
385			if (cst_lst.ibytes == 0 && cst_lst.obytes == 0)
386			return;
387
388			/* CSSTAT is put in so scripts can easily find the line */
389			LOG (llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
390			ctime (&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
391			now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes, cst_lst.max_conn, now - cst_lst.time_start);
392			cst_lst.ibytes = 0;
393			cst_lst.obytes = 0;
394			cst_lst.time_start = now;
395	elmex	1.1	}
396			#endif
397	root	1.9