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>
# 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 * 1000
#define SOCKET_TIMEOUT2 20 * 1000

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 < diff && diff < 0x80000000UL   // ack delayed for 20s
          && SOCKET_TIMEOUT2 < 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);
          destroy ();
        }
    }
#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");
          destroy ();
          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));
          destroy ();
          return;
        }
    }

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

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

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

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

      if (inbuf_len == sizeof (inbuf))
        {
          send_packet_printf ("drawinfo %d input buffer overflow - closing connection.", NDI_RED);
          destroy ();
          return -1;
        }
    }

  return 0;
}

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

/*****************************************************************************
 * Start of command dispatch area.
 * The commands here are protocol commands. 
 ****************************************************************************/

// SocketCommand, PlayingCommand, should not exist with those ugly casts
#define SC(cb) (void *)static_cast<void (*)(char *, int, client *)>(cb),
#define PC(cb) (void *)static_cast<void (*)(char *, int, player *)>(cb), PF_PLAYER |

/**
 * Dispatch table for the server.
 */
static struct packet_type packets[] = {
  {"ncom",        PC(NewPlayerCmd) PF_PLAYING },
  {"command",     PC(PlayerCmd)    PF_PLAYING },

  {"examine",     PC(ExamineCmd)   PF_PLAYING },
  {"apply",       PC(ApplyCmd)     PF_PLAYING },
  {"reply",       PC(ReplyCmd)     0 },
  {"lookat",      PC(LookAt)       PF_PLAYING },
  {"lock",        PC(LockItem)     PF_PLAYING },
  {"mark",        PC(MarkItem)     PF_PLAYING },
  {"move",        PC(MoveCmd)      PF_PLAYING },
  {"ext",         PC(ExtCmd)       0 },            /* CF+ */
  {"mapredraw",   PC(MapRedrawCmd) 0 },       /* Added: phil */
  {"mapinfo",     PC(MapInfoCmd)   0 },   /* CF+ */

  {"exti",        SC(ExtiCmd)      0 }, /* CF+ */
  {"addme",       SC(AddMeCmd)     0 },
  {"askface",     SC(SendFaceCmd)  0 },     /* Added: phil */
  {"requestinfo", SC(RequestInfo)  0 },
  {"setfacemode", SC(SetFaceMode)  0 },
  {"setsound",    SC(SetSound)     0 },
  {"setup",       SC(SetUp)        0 },
  {"version",     SC(VersionCmd)   0 },
  {"toggleextendedinfos", SC(ToggleExtendedInfos) 0 }, /*Added: tchize */
  {"toggleextendedtext",  SC(ToggleExtendedText)  0 },   /*Added: tchize */
  {"asksmooth",   SC(AskSmooth)    0 },     /*Added: tchize (smoothing technologies) */
};

bool
client::may_execute (const packet_type *pkt) const
{
  return (!(pkt->flags & PF_PLAYER)  || pl)
      && (!(pkt->flags & PF_PLAYING) || (pl && pl->state == ST_PLAYING));
}

void
client::execute (const packet_type *pkt, char *data, int datalen)
{
  if (may_execute (pkt))
    {
      //TODO: only one format
      if (pkt->flags & PF_PLAYER)
        ((void (*)(char *, int, player *))pkt->cb)((char *)data, datalen, pl);
      else
        ((void (*)(char *, int, client *))pkt->cb)((char *)data, datalen, this);
    }
  else
    send_packet_printf ("drawinfo %d ERROR: you cannot execute '%s' now.", NDI_RED, pkt->name);
}

bool
client::handle_packet ()
{
  int pkt_len = next_packet ();

  if (!pkt_len)
    return false;
  else if (pkt_len < 0)
    {
      LOG (llevError, "read error on player %s\n",
                      pl && pl->ob ? &pl->ob->name : "[anonymous]");
      destroy ();
      return false;
    }

  inbuf [pkt_len] = 0;      /* Terminate buffer - useful for string data */

  /* First, break out beginning word.  There are at least
   * a few commands that do not have any paremeters.  If
   * we get such a command, don't worry about trying
   * to break it up.
   */
  int datalen;
  char *data = strchr ((char *)inbuf + 2, ' ');

  if (data)
    {
      *data++ = 0;
      datalen = pkt_len - (data - (char *)inbuf);
    }
  else
    {
      data = (char *)inbuf + 2; // better read garbage than segfault
      datalen = 0;
    }

  for (packet_type *pkt = packets; pkt < packets + (sizeof (packets) / sizeof (packets[0])); ++pkt)
    if (!strcmp ((char *)inbuf + 2, pkt->name))
      {
        if (pkt->flags & PF_PLAYER)
          queue_command (pkt, data, datalen);
        else
          execute (pkt, data, datalen);

        goto next_packet;
      }

  // If we get here, we didn't find a valid command.
  send_packet_printf ("drawinfo %d ERROR: command '%s' not supported.", NDI_RED, (char *)inbuf + 2);
next_packet:
  skip_packet (pkt_len);

  // input buffer has space again
  socket_ev.poll (socket_ev.poll () | PE_R);

  return true;
}

// callback called when socket is either readable or writable
void
client::socket_cb (iow &w, int got)
{
  //TODO remove when we have better socket cleanup logic
  if (status == Ns_Dead)
    {
      socket_ev.poll (0);
      return;
    }

  if (got & PE_W)
    {
      write_outputbuffer ();

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

  if (got & PE_R)
    {
      //TODO: rate-limit tcp connection in better ways, important

      int amount = sizeof (inbuf) - inbuf_len;

      if (!amount)
        {
          // input buffer full
          socket_ev.poll (socket_ev.poll () & ~PE_R);
          return;
        }

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

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

          // should not be here, normally
        }
      else
        {
          inbuf_len += amount;

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

          cmd_ev.start ();
        }
    }
}

// called whenever we have additional commands to process
void
client::cmd_cb (iw &w)
{
  if (handle_packet ())
    w.start ();
  else
    flush ();
}

/*******************************************************************************
 *
 * 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)
    return;

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

/**
 * 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));
}

void
client::send_packet_printf (const char *format, ...)
{
  packet sl;

  va_list ap;
  va_start (ap, format);
  sl.vprintf (format, ap);
  va_end (ap);

  send_packet (sl);
}

/***********************************************************************
 *
 * 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::vprintf (const char *format, va_list ap)
{
  int size = room ();

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

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

  cur += len;
}

/******************************************************************************
 *
 * 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:	1.26
Committed:	Tue Dec 19 04:58:05 2006 UTC (17 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.25:	+22 -26 lines
Log Message:	- separate all comamnds into immediate/socket-level and queued/player-level - clean up player command handling, handle up to 8 commands/tick
#	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	# include <netinet/tcp.h>
46	#endif
47
48	// use a really low timeout, as it doesn't cost any bandwidth, and you can
49	// easily die in 20 seconds...
50	#define SOCKET_TIMEOUT1 10 * 1000
51	#define SOCKET_TIMEOUT2 20 * 1000
52
53	void
54	client::flush ()
55	{
56	#ifdef __linux__
57	// check time of last ack, and, if too old, kill connection
58	struct tcp_info tcpi;
59	socklen_t len = sizeof (tcpi);
60
61	if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
62	{
63	unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;
64
65	rtt = tcpi.tcpi_rtt;
66	rttvar = tcpi.tcpi_rttvar;
67
68	if (tcpi.tcpi_unacked && SOCKET_TIMEOUT1 < diff && diff < 0x80000000UL // ack delayed for 20s
69	&& SOCKET_TIMEOUT2 < tcpi.tcpi_last_data_sent) // no data sent for 10s
70	{
71	LOG (llevDebug, "Connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
72	(unsigned) tcpi.tcpi_last_ack_recv, (unsigned) tcpi.tcpi_last_data_sent, (unsigned) tcpi.tcpi_unacked);
73	destroy ();
74	}
75	}
76	#endif
77
78	/**
79	* Writes data to socket.
80	*
81	* When the socket is clear to write, and we have backlogged data, this
82	* is called to write it out.
83	*/
84
85	if (!outputbuffer.len \|\| socket_ev.poll () & PE_W)
86	return;
87
88	write_outputbuffer ();
89	}
90
91	void
92	client::write_outputbuffer ()
93	{
94	while (outputbuffer.len)
95	{
96	int res = write (fd, outputbuffer.data + outputbuffer.start,
97	min (outputbuffer.len, SOCKETBUFSIZE - outputbuffer.start));
98
99	if (res > 0)
100	{
101	outputbuffer.start += res;
102	/* wrap back to start of buffer */
103	if (outputbuffer.start == SOCKETBUFSIZE)
104	outputbuffer.start = 0;
105
106	outputbuffer.len -= res;
107	#ifdef CS_LOGSTATS
108	cst_tot.obytes += res;
109	cst_lst.obytes += res;
110	#endif
111	}
112	else if (res == 0)
113	{
114	LOG (llevError, "socket write failed, connection closed.\n");
115	destroy ();
116	return;
117	}
118	else if (errno == EINTR)
119	{
120	// just retry
121	}
122	else if (errno == EAGAIN)
123	{
124	// delay till ready
125	socket_ev.poll (socket_ev.poll () \| PE_W);
126	socket_ev.start ();
127	return;
128	}
129	else
130	{
131	LOG (llevError, "socket write failed: %s\n", strerror (errno));
132	destroy ();
133	return;
134	}
135	}
136
137	socket_ev.poll (socket_ev.poll () & ~PE_W);
138	}
139
140	/******************************************************************************
141	*
142	* Start of read routines.
143	*
144	******************************************************************************/
145
146	int
147	client::next_packet ()
148	{
149	if (inbuf_len >= 2)
150	{
151	int pkt_len = (inbuf [0] << 8) \| inbuf [1];
152
153	if (inbuf_len >= 2 + pkt_len)
154	return 2 + pkt_len;
155
156	if (inbuf_len == sizeof (inbuf))
157	{
158	send_packet_printf ("drawinfo %d input buffer overflow - closing connection.", NDI_RED);
159	destroy ();
160	return -1;
161	}
162	}
163
164	return 0;
165	}
166
167	void
168	client::skip_packet (int len)
169	{
170	inbuf_len -= len;
171	memmove (inbuf, inbuf + len, inbuf_len);
172	}
173
174	/*****************************************************************************
175	* Start of command dispatch area.
176	* The commands here are protocol commands.
177	****************************************************************************/
178
179	// SocketCommand, PlayingCommand, should not exist with those ugly casts
180	#define SC(cb) (void )static_cast<void ()(char , int, client )>(cb),
181	#define PC(cb) (void )static_cast<void ()(char , int, player )>(cb), PF_PLAYER \|
182
183	/**
184	* Dispatch table for the server.
185	*/
186	static struct packet_type packets[] = {
187	{"ncom", PC(NewPlayerCmd) PF_PLAYING },
188	{"command", PC(PlayerCmd) PF_PLAYING },
189
190	{"examine", PC(ExamineCmd) PF_PLAYING },
191	{"apply", PC(ApplyCmd) PF_PLAYING },
192	{"reply", PC(ReplyCmd) 0 },
193	{"lookat", PC(LookAt) PF_PLAYING },
194	{"lock", PC(LockItem) PF_PLAYING },
195	{"mark", PC(MarkItem) PF_PLAYING },
196	{"move", PC(MoveCmd) PF_PLAYING },
197	{"ext", PC(ExtCmd) 0 }, /* CF+ */
198	{"mapredraw", PC(MapRedrawCmd) 0 }, /* Added: phil */
199	{"mapinfo", PC(MapInfoCmd) 0 }, /* CF+ */
200
201	{"exti", SC(ExtiCmd) 0 }, /* CF+ */
202	{"addme", SC(AddMeCmd) 0 },
203	{"askface", SC(SendFaceCmd) 0 }, /* Added: phil */
204	{"requestinfo", SC(RequestInfo) 0 },
205	{"setfacemode", SC(SetFaceMode) 0 },
206	{"setsound", SC(SetSound) 0 },
207	{"setup", SC(SetUp) 0 },
208	{"version", SC(VersionCmd) 0 },
209	{"toggleextendedinfos", SC(ToggleExtendedInfos) 0 }, /Added: tchize /
210	{"toggleextendedtext", SC(ToggleExtendedText) 0 }, /Added: tchize /
211	{"asksmooth", SC(AskSmooth) 0 }, /Added: tchize (smoothing technologies) /
212	};
213
214	bool
215	client::may_execute (const packet_type *pkt) const
216	{
217	return (!(pkt->flags & PF_PLAYER) \|\| pl)
218	&& (!(pkt->flags & PF_PLAYING) \|\| (pl && pl->state == ST_PLAYING));
219	}
220
221	void
222	client::execute (const packet_type pkt, char data, int datalen)
223	{
224	if (may_execute (pkt))
225	{
226	//TODO: only one format
227	if (pkt->flags & PF_PLAYER)
228	((void ()(char , int, player ))pkt->cb)((char )data, datalen, pl);
229	else
230	((void ()(char , int, client ))pkt->cb)((char )data, datalen, this);
231	}
232	else
233	send_packet_printf ("drawinfo %d ERROR: you cannot execute '%s' now.", NDI_RED, pkt->name);
234	}
235
236	bool
237	client::handle_packet ()
238	{
239	int pkt_len = next_packet ();
240
241	if (!pkt_len)
242	return false;
243	else if (pkt_len < 0)
244	{
245	LOG (llevError, "read error on player %s\n",
246	pl && pl->ob ? &pl->ob->name : "[anonymous]");
247	destroy ();
248	return false;
249	}
250
251	inbuf [pkt_len] = 0; /* Terminate buffer - useful for string data */
252
253	/* First, break out beginning word. There are at least
254	* a few commands that do not have any paremeters. If
255	* we get such a command, don't worry about trying
256	* to break it up.
257	*/
258	int datalen;
259	char data = strchr ((char )inbuf + 2, ' ');
260
261	if (data)
262	{
263	*data++ = 0;
264	datalen = pkt_len - (data - (char *)inbuf);
265	}
266	else
267	{
268	data = (char *)inbuf + 2; // better read garbage than segfault
269	datalen = 0;
270	}
271
272	for (packet_type *pkt = packets; pkt < packets + (sizeof (packets) / sizeof (packets[0])); ++pkt)
273	if (!strcmp ((char *)inbuf + 2, pkt->name))
274	{
275	if (pkt->flags & PF_PLAYER)
276	queue_command (pkt, data, datalen);
277	else
278	execute (pkt, data, datalen);
279
280	goto next_packet;
281	}
282
283	// If we get here, we didn't find a valid command.
284	send_packet_printf ("drawinfo %d ERROR: command '%s' not supported.", NDI_RED, (char *)inbuf + 2);
285	next_packet:
286	skip_packet (pkt_len);
287
288	// input buffer has space again
289	socket_ev.poll (socket_ev.poll () \| PE_R);
290
291	return true;
292	}
293
294	// callback called when socket is either readable or writable
295	void
296	client::socket_cb (iow &w, int got)
297	{
298	//TODO remove when we have better socket cleanup logic
299	if (status == Ns_Dead)
300	{
301	socket_ev.poll (0);
302	return;
303	}
304
305	if (got & PE_W)
306	{
307	write_outputbuffer ();
308
309	if (!outputbuffer.len)
310	socket_ev.poll (socket_ev.poll () & ~PE_W);
311	}
312
313	if (got & PE_R)
314	{
315	//TODO: rate-limit tcp connection in better ways, important
316
317	int amount = sizeof (inbuf) - inbuf_len;
318
319	if (!amount)
320	{
321	// input buffer full
322	socket_ev.poll (socket_ev.poll () & ~PE_R);
323	return;
324	}
325
326	amount = read (fd, inbuf + inbuf_len, amount);
327
328	if (!amount)
329	{
330	destroy ();
331	return;
332	}
333	else if (amount < 0)
334	{
335	if (errno != EAGAIN && errno != EINTR)
336	{
337	LOG (llevError, "read error: %s\n", strerror (errno));
338	destroy ();
339	return;
340	}
341
342	// should not be here, normally
343	}
344	else
345	{
346	inbuf_len += amount;
347
348	cst_tot.ibytes += amount;
349	cst_lst.ibytes += amount;
350
351	cmd_ev.start ();
352	}
353	}
354	}
355
356	// called whenever we have additional commands to process
357	void
358	client::cmd_cb (iw &w)
359	{
360	if (handle_packet ())
361	w.start ();
362	else
363	flush ();
364	}
365
366	/*******************************************************************************
367	*
368	* Start of write related routines.
369	*
370	******************************************************************************/
371
372	/**
373	* Adds data to a socket buffer for whatever reason.
374	*
375	* ns is the socket we are adding the data to, buf is the start of the
376	* data, and len is the number of bytes to add.
377	*/
378	void
379	client::send (void *buf_, int len)
380	{
381	char buf = (char )buf_;
382	char *pos = buf;
383	int amt = 0;
384
385	if (status == Ns_Dead \|\| !buf)
386	return;
387
388	if ((len + outputbuffer.len) > SOCKETBUFSIZE)
389	{
390	LOG (llevDebug, "socket on fd %d has overrun internal buffer - marking as dead\n", fd);
391	destroy ();
392	return;
393	}
394
395	int avail, end;
396
397	/* data + end is where we start putting the new data. The last byte
398	* currently in use is actually data + end -1
399	*/
400	end = outputbuffer.start + outputbuffer.len;
401	/* The buffer is already in a wrapped state, so adjust end */
402	if (end >= SOCKETBUFSIZE)
403	end -= SOCKETBUFSIZE;
404
405	avail = SOCKETBUFSIZE - end;
406
407	/* We can all fit it behind the current data without wrapping */
408	if (avail >= len)
409	memcpy (outputbuffer.data + end, buf, len);
410	else
411	{
412	memcpy (outputbuffer.data + end, buf, avail);
413	memcpy (outputbuffer.data, buf + avail, len - avail);
414	}
415
416	outputbuffer.len += len;
417	}
418
419	/**
420	* Takes a string of data, and writes it out to the socket. A very handy
421	* shortcut function.
422	*/
423	void
424	client::send_packet (packet &sl)
425	{
426	if (status == Ns_Dead)
427	return;
428
429	if (sl.length () >= MAXSOCKBUF)
430	{
431	LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", sl.length ());
432	/* Almost certainly we've overflowed a buffer, so quit now to make
433	* it easier to debug.
434	*/
435	abort ();
436	}
437
438	if (!sl.length ())
439	return;
440
441	assert (sl.hdrlen == 2);
442
443	sl.buf_ [0] = sl.length () >> 8;
444	sl.buf_ [1] = sl.length () ;
445
446	send (sl.buf_, sl.length () + sl.hdrlen);
447	}
448
449	void
450	client::send_packet (const char *buf, int len)
451	{
452	packet sl;
453
454	sl << data (buf, len);
455	send_packet (sl);
456	}
457
458	void
459	client::send_packet (const char *buf)
460	{
461	send_packet (buf, strlen (buf));
462	}
463
464	void
465	client::send_packet_printf (const char *format, ...)
466	{
467	packet sl;
468
469	va_list ap;
470	va_start (ap, format);
471	sl.vprintf (format, ap);
472	va_end (ap);
473
474	send_packet (sl);
475	}
476
477	/***********************************************************************
478	*
479	* packet functions/utilities
480	*
481	**********************************************************************/
482
483	packet &packet::operator <<(const data &v)
484	{
485	if (room () < v.len)
486	reset ();
487	else
488	{
489	if (v.len)
490	{
491	memcpy (cur, v.ptr, v.len);
492	cur += v.len;
493	}
494	}
495
496	return *this;
497	}
498
499	packet &packet::operator <<(const data8 &v)
500	{
501	unsigned int len = min (v.len, 0x00FF);
502	return *this << uint8 (len) << data (v.ptr, len);
503	}
504
505	packet &packet::operator <<(const data16 &v)
506	{
507	unsigned int len = min (v.len, 0xFFFF);
508	return *this << uint16 (len) << data (v.ptr, len);
509	}
510
511	packet &packet::operator <<(const char *v)
512	{
513	return *this << data (v, strlen (v ? v : 0));
514	}
515
516	void
517	packet::vprintf (const char *format, va_list ap)
518	{
519	int size = room ();
520
521	int len = vsnprintf ((char *)cur, size, format, ap);
522
523	if (len >= size)
524	return reset ();
525
526	cur += len;
527	}
528
529	/******************************************************************************
530	*
531	* statistics logging functions.
532	*
533	******************************************************************************/
534
535	#ifdef CS_LOGSTATS
536
537	/* cst_tot is for the life of the server, cst_last is for the last series of
538	* stats
539	*/
540	CS_Stats cst_tot, cst_lst;
541
542	/**
543	* Writes out the gathered stats. We clear cst_lst.
544	*/
545	void
546	write_cs_stats (void)
547	{
548	time_t now = time (NULL);
549
550	/* If no connections recently, don't both to log anything */
551	if (cst_lst.ibytes == 0 && cst_lst.obytes == 0)
552	return;
553
554	/* CSSTAT is put in so scripts can easily find the line */
555	LOG (llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
556	ctime (&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
557	now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes, cst_lst.max_conn, now - cst_lst.time_start);
558	cst_lst.ibytes = 0;
559	cst_lst.obytes = 0;
560	cst_lst.time_start = now;
561	}
562	#endif
563