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, 6 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
#	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 <sproto.h>
39	root	1.11	#include <cstdarg>
40	elmex	1.1
41			#ifdef __linux__
42			# include <sys/types.h>
43			# include <sys/socket.h>
44			# include <netinet/in.h>
45	root	1.5	# define TCP_HZ 1000 // sorry...
46	elmex	1.1	# 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	root	1.5	void
55	root	1.22	client::flush ()
56	elmex	1.1	{
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	root	1.20	if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
63	elmex	1.1	{
64			unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;
65
66	root	1.21	rtt = tcpi.tcpi_rtt;
67			rttvar = tcpi.tcpi_rttvar;
68
69	root	1.5	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	elmex	1.1	{
72	root	1.20	LOG (llevDebug, "Connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
73	root	1.5	(unsigned) tcpi.tcpi_last_ack_recv, (unsigned) tcpi.tcpi_last_data_sent, (unsigned) tcpi.tcpi_unacked);
74	root	1.20	status = Ns_Dead;
75	elmex	1.1	}
76			}
77	root	1.20	#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	elmex	1.1
92	root	1.20	void
93	root	1.22	client::write_outputbuffer ()
94	root	1.20	{
95			while (outputbuffer.len)
96			{
97			int res = write (fd, outputbuffer.data + outputbuffer.start,
98			min (outputbuffer.len, SOCKETBUFSIZE - outputbuffer.start));
99	root	1.5
100	root	1.20	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	elmex	1.1	#endif
112	root	1.20	}
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	elmex	1.1	}
140
141			/***********************************************************************
142			*
143	root	1.14	* packet functions/utilities
144	elmex	1.1	*
145			**********************************************************************/
146
147	root	1.14	packet &packet::operator <<(const data &v)
148	elmex	1.1	{
149	root	1.15	if (room () < v.len)
150			reset ();
151			else
152	root	1.11	{
153	root	1.15	if (v.len)
154			{
155			memcpy (cur, v.ptr, v.len);
156			cur += v.len;
157			}
158	root	1.11	}
159	root	1.9
160	root	1.11	return *this;
161			}
162	root	1.9
163	root	1.14	packet &packet::operator <<(const data8 &v)
164	root	1.11	{
165			unsigned int len = min (v.len, 0x00FF);
166			return *this << uint8 (len) << data (v.ptr, len);
167	elmex	1.1	}
168
169	root	1.14	packet &packet::operator <<(const data16 &v)
170	elmex	1.1	{
171	root	1.11	unsigned int len = min (v.len, 0xFFFF);
172			return *this << uint16 (len) << data (v.ptr, len);
173			}
174	root	1.9
175	root	1.14	packet &packet::operator <<(const char *v)
176	root	1.11	{
177			return *this << data (v, strlen (v ? v : 0));
178	elmex	1.1	}
179
180	root	1.11	void
181	root	1.14	packet::printf (const char *format, ...)
182	root	1.10	{
183	root	1.15	int size = room ();
184
185	root	1.11	va_list ap;
186			va_start (ap, format);
187	root	1.15	int len = vsnprintf ((char *)cur, size, format, ap);
188			va_end (ap);
189	root	1.11
190	root	1.15	if (len >= size)
191			return reset ();
192	root	1.10
193	root	1.15	cur += len;
194	root	1.10	}
195
196	elmex	1.1	/******************************************************************************
197			*
198			* Start of read routines.
199			*
200			******************************************************************************/
201
202	root	1.5	int
203	root	1.22	client::read_packet ()
204	elmex	1.1	{
205	root	1.12	for (;;)
206	root	1.5	{
207	root	1.12	if (inbuf_len >= 2)
208	root	1.5	{
209	root	1.12	unsigned int pkt_len = (inbuf [0] << 8) \| inbuf [1];
210
211			if (inbuf_len >= 2 + pkt_len)
212			return pkt_len + 2;
213	root	1.5	}
214	pippijn	1.8
215	root	1.12	int amount = sizeof (inbuf) - inbuf_len;
216
217			if (amount <= 0)
218	root	1.5	{
219	root	1.12	LOG (llevError, "packet too large");//TODO
220			return -1;
221	root	1.3	}
222	elmex	1.1
223	root	1.12	amount = read (fd, inbuf + inbuf_len, amount);
224
225			if (!amount)
226	root	1.5	{
227	root	1.12	status = Ns_Dead;
228			return -1;
229	root	1.5	}
230	root	1.12	else if (amount < 0)
231	root	1.5	{
232	root	1.12	if (errno != EAGAIN && errno != EINTR)
233	root	1.5	{
234	root	1.20	LOG (llevError, "read error: %s\n", strerror (errno));
235	root	1.12	return -1;
236	root	1.3	}
237	root	1.12
238			return 0;
239	root	1.3	}
240	root	1.12
241			inbuf_len += amount;
242
243			cst_tot.ibytes += amount;
244			cst_lst.ibytes += amount;
245	root	1.5	}
246	root	1.12	}
247
248			void
249	root	1.22	client::skip_packet (int len)
250	root	1.12	{
251			inbuf_len -= len;
252			memmove (inbuf, inbuf + len, inbuf_len);
253	elmex	1.1	}
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	root	1.20	void
268	root	1.22	client::send (void *buf_, int len)
269	root	1.20	{
270			char buf = (char )buf_;
271			char *pos = buf;
272			int amt = 0;
273	elmex	1.1
274	root	1.20	if (status == Ns_Dead \|\| !buf)
275			{
276			LOG (llevDebug, "Write_To_Socket called with dead socket\n");
277			return;
278			}
279	elmex	1.1
280	root	1.20	if ((len + outputbuffer.len) > SOCKETBUFSIZE)
281	root	1.5	{
282	root	1.20	LOG (llevDebug, "Socket on fd %d has overrun internal buffer - marking as dead\n", fd);
283			status = Ns_Dead;
284	root	1.5	return;
285			}
286
287	root	1.20	int avail, end;
288
289	root	1.5	/* data + end is where we start putting the new data. The last byte
290			* currently in use is actually data + end -1
291			*/
292	root	1.20	end = outputbuffer.start + outputbuffer.len;
293	root	1.5	/* The buffer is already in a wrapped state, so adjust end */
294			if (end >= SOCKETBUFSIZE)
295			end -= SOCKETBUFSIZE;
296	root	1.7
297	root	1.5	avail = SOCKETBUFSIZE - end;
298	elmex	1.1
299	root	1.5	/* We can all fit it behind the current data without wrapping */
300			if (avail >= len)
301	root	1.20	memcpy (outputbuffer.data + end, buf, len);
302	root	1.5	else
303			{
304	root	1.20	memcpy (outputbuffer.data + end, buf, avail);
305			memcpy (outputbuffer.data, buf + avail, len - avail);
306	elmex	1.1	}
307	root	1.7
308	root	1.20	outputbuffer.len += len;
309	elmex	1.1	}
310
311	root	1.5	void
312	root	1.22	client::socket_cb (iow &w, int got)
313	elmex	1.1	{
314	root	1.20	write_outputbuffer ();
315	elmex	1.1
316	root	1.20	if (!outputbuffer.len)
317			socket_ev.poll (socket_ev.poll () & ~PE_W);
318	root	1.19	}
319
320	elmex	1.1	/**
321			* Takes a string of data, and writes it out to the socket. A very handy
322			* shortcut function.
323			*/
324	root	1.13	void
325	root	1.22	client::send_packet (packet &sl)
326	root	1.13	{
327	root	1.19	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	root	1.13	}
349
350	root	1.5	void
351	root	1.22	client::send_packet (const char *buf, int len)
352	elmex	1.1	{
353	root	1.14	packet sl;
354	elmex	1.1
355	root	1.13	sl << data (buf, len);
356			send_packet (sl);
357	elmex	1.1	}
358
359	root	1.13	void
360	root	1.22	client::send_packet (const char *buf)
361	root	1.13	{
362			send_packet (buf, strlen (buf));
363			}
364	elmex	1.1
365			/******************************************************************************
366			*
367			* statistics logging functions.
368			*
369			******************************************************************************/
370
371			#ifdef CS_LOGSTATS
372	root	1.5
373	elmex	1.1	/* 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	root	1.5	void
382			write_cs_stats (void)
383	elmex	1.1	{
384	root	1.5	time_t now = time (NULL);
385	elmex	1.1
386	root	1.5	/* 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	elmex	1.1	}
398			#endif
399	root	1.9