server/socket/lowlevel.C

/*
 * This file is part of Crossfire TRT, the Multiplayer Online Role Playing Game.
 * 
 * Copyright (©) 2005,2006,2007 Marc Alexander Lehmann / Robin Redeker / the Crossfire TRT team
 * Copyright (©) 1992,2007 Frank Tore Johansen
 * 
 * Crossfire TRT 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 Crossfire TRT; if not, write to the Free Software Foundation, Inc. 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 * 
 * The authors can be reached via e-mail to <crossfire@schmorp.de>
 */

/**
 * \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

// disconnect a socket after this many seconds without an ack
#define SOCKET_TIMEOUT 8.

// force a packet when idle for more than this many seconds,
// forcing an ack regularly.
#define IDLE_PING 2.

void
client::flush ()
{
  if (destroyed ())
    return;

#ifdef __linux__
  // check about once per second, spread evenly over all clients
  if (!((pticks + fd) & 7))
    {
      // 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))
        {
          rtt    = tcpi.tcpi_rtt;
          rttvar = tcpi.tcpi_rttvar;

          if (tcpi.tcpi_last_ack_recv > int (SOCKET_TIMEOUT * 1000))
            {
              send_msg (NDI_RED, "connection-timeout", "safety disconnect due to tcp/ip timeout (no packets received)");
              write_outputbuffer ();

              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.
   */

  // write a nop to the socket at least every IDLE_NOP seconds.
  if (!outputbuffer.len)
    {
      if (last_send + IDLE_PING <= NOW)
        {
          // this is a bit ugly, but map1/map1a seem to be the only
          // nop'able commands and they are quite small.
          packet sl (mapmode == Map1Cmd ? "map1" : "map1a");
          send_packet (sl);
        }
      else
        return;
    }

  if (socket_ev.poll () & PE_W)
    return;

  last_send = NOW;
  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;
        }
      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 | PF_COMMAND6 },
  {"command",     PC(PlayerCmd)    PF_PLAYING | PF_COMMAND0 },

  {"examine",     PC(ExamineCmd)   PF_PLAYING },
  {"ex",          PC(ExCmd)        PF_PLAYING },
  {"apply",       PC(ApplyCmd)     PF_PLAYING },
  {"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 },
  {"mapinfo",     PC(MapInfoCmd)   0 }, // CF+

  {"reply",       SC(ReplyCmd)     0 },
  {"exti",        SC(ExtiCmd)      0 }, // CF+
  {"addme",       SC(AddMeCmd)     0 },
  {"askface",     SC(AskFaceCmd)   0 },
  {"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) || state == ST_PLAYING);
}

// HACK: some commands currently should be executed 
// even when the player is frozen. this hack detects
// those commands. it should be folded into may_execute,
// but kept seperate to emphasise the hack aspect, i.e.
// do it better, then remove.
static bool
always_immediate (const client *ns, const packet_type *pkt, const char *data, int len)
{
  if (!(pkt->flags & (PF_COMMAND0 | PF_COMMAND6)))
    return false;

  if (!ns->pl || !ns->pl->ob || !ns->pl->ob->map)
    return false;

  if (pkt->flags & PF_COMMAND6)
    {
      data += 6;
      len  -= 6;
    }

  if (len > 4 && !strncmp (data, "say " , 4))
    return true;
  if (len > 5 && !strncmp (data, "chat ", 5))
    return true;

  return false;
}

void
client::execute (const packet_type *pkt, char *data, int datalen)
{
  if (may_execute (pkt) || always_immediate (this, pkt, data, datalen))
    {
      //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 && !always_immediate (this, pkt, data, datalen))
          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 (destroyed ())
    {
      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;

          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_;

  if (destroyed () || !buf)
    return;

  if (len + outputbuffer.len > SOCKETBUFSIZE)
    {
      LOG (llevDebug, "socket on fd %d has overrun internal buffer - marking as dead\n", fd);
      // shutdown the socket, this is safer than destroying it immediately
      // as lots of code in the callchain might still access the map etc.
      shutdown (fd, SHUT_RDWR);
      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 (destroyed ())
    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);
}

void
client::send_drawinfo (const char *msg, int flags)
{
  send_packet_printf ("drawinfo %d %s", flags, msg);
}

void
client::send_msg (int color, const char *type, const char *msg)
{
  if (can_msg)
    send_packet_printf ("msg %d %s %s", color, type, msg);
  else if (color < 0)
    return; // client cannot handle this
  else if (strchr (msg, '<') || strchr (msg, '&'))
    {
      //TODO: should escape/modify to old syntax
      send_packet_printf ("drawinfo %d %s", color, msg);
    }
  else
    send_packet_printf ("drawinfo %d %s", color, msg);
}

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

packet::packet (const char *name)
{
  reset ();

  int len = strlen (name);
  memcpy (cur, name, len); cur += len;
  *cur++ = ' ';
}

packet &packet::operator <<(const ber32 v)
{
  enum { maxlen = 32 / 7 + 1};
  uint8 buf[maxlen];
  uint8 *p = buf + maxlen;
  uint32 val = v.val;

  *--p = val & 0x7F;

  while (val > 0x7F)
    {
      val >>= 7;
      *--p = (val & 0x7F) | 0x80;
    }

  return *this << data (p, buf + maxlen - p);
}

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;
}

Revision:	1.43
Committed:	Sat Jun 9 22:54:04 2007 UTC (16 years, 11 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.42:	+40 -61 lines
Log Message:	- introduce global NOW variable storing current tick time. - force some packet send at least every 2 seconds, forcing an ack reply. - timeout connections on ack delay exclusively, by default disconnect after 8 seconds (allowing for at least 5.5s of network hiccups). (linux only, should port to bsds). - nuke ericserver stats code. - reduce number of syscalls (less gettimeofday, only get tcp_info about once/second). - get rid of coroapi.time () in favour of now ().
#	Content
1	/*
2	* This file is part of Crossfire TRT, the Multiplayer Online Role Playing Game.
3	*
4	* Copyright (©) 2005,2006,2007 Marc Alexander Lehmann / Robin Redeker / the Crossfire TRT team
5	* Copyright (©) 1992,2007 Frank Tore Johansen
6	*
7	* Crossfire TRT is free software; you can redistribute it and/or modify it
8	* under the terms of the GNU General Public License as published by the Free
9	* Software Foundation; either version 2 of the License, or (at your option)
10	* any later version.
11	*
12	* This program is distributed in the hope that it will be useful, but
13	* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14	* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15	* for more details.
16	*
17	* You should have received a copy of the GNU General Public License along
18	* with Crossfire TRT; if not, write to the Free Software Foundation, Inc. 51
19	* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20	*
21	* The authors can be reached via e-mail to <crossfire@schmorp.de>
22	*/
23
24	/**
25	* \file
26	* Low-level socket-related functions.
27	*
28	* \date 2003-12-02
29	*
30	* Contains some base functions that both the client and server
31	* can use. As such, depending what we are being compiled for will
32	* determine what we can include. the client is designed have
33	* CFCLIENT defined as part of its compile flags.
34	*/
35
36	using namespace std;
37
38	#include <global.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	# include <netinet/tcp.h>
47	#endif
48
49	// disconnect a socket after this many seconds without an ack
50	#define SOCKET_TIMEOUT 8.
51
52	// force a packet when idle for more than this many seconds,
53	// forcing an ack regularly.
54	#define IDLE_PING 2.
55
56	void
57	client::flush ()
58	{
59	if (destroyed ())
60	return;
61
62	#ifdef __linux__
63	// check about once per second, spread evenly over all clients
64	if (!((pticks + fd) & 7))
65	{
66	// check time of last ack, and, if too old, kill connection
67	struct tcp_info tcpi;
68	socklen_t len = sizeof (tcpi);
69
70	if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
71	{
72	rtt = tcpi.tcpi_rtt;
73	rttvar = tcpi.tcpi_rttvar;
74
75	if (tcpi.tcpi_last_ack_recv > int (SOCKET_TIMEOUT * 1000))
76	{
77	send_msg (NDI_RED, "connection-timeout", "safety disconnect due to tcp/ip timeout (no packets received)");
78	write_outputbuffer ();
79
80	LOG (llevDebug, "connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
81	(unsigned)tcpi.tcpi_last_ack_recv, (unsigned)tcpi.tcpi_last_data_sent, (unsigned)tcpi.tcpi_unacked);
82	destroy ();
83	}
84	}
85	}
86	#endif
87
88	/**
89	* Writes data to socket.
90	*
91	* When the socket is clear to write, and we have backlogged data, this
92	* is called to write it out.
93	*/
94
95	// write a nop to the socket at least every IDLE_NOP seconds.
96	if (!outputbuffer.len)
97	{
98	if (last_send + IDLE_PING <= NOW)
99	{
100	// this is a bit ugly, but map1/map1a seem to be the only
101	// nop'able commands and they are quite small.
102	packet sl (mapmode == Map1Cmd ? "map1" : "map1a");
103	send_packet (sl);
104	}
105	else
106	return;
107	}
108
109	if (socket_ev.poll () & PE_W)
110	return;
111
112	last_send = NOW;
113	write_outputbuffer ();
114	}
115
116	void
117	client::write_outputbuffer ()
118	{
119	while (outputbuffer.len)
120	{
121	int res = write (fd, outputbuffer.data + outputbuffer.start,
122	min (outputbuffer.len, SOCKETBUFSIZE - outputbuffer.start));
123
124	if (res > 0)
125	{
126	outputbuffer.start += res;
127	/* wrap back to start of buffer */
128	if (outputbuffer.start == SOCKETBUFSIZE)
129	outputbuffer.start = 0;
130
131	outputbuffer.len -= res;
132	}
133	else if (res == 0)
134	{
135	LOG (llevError, "socket write failed, connection closed.\n");
136	destroy ();
137	return;
138	}
139	else if (errno == EINTR)
140	{
141	// just retry
142	}
143	else if (errno == EAGAIN)
144	{
145	// delay till ready
146	socket_ev.poll (socket_ev.poll () \| PE_W);
147	socket_ev.start ();
148	return;
149	}
150	else
151	{
152	LOG (llevError, "socket write failed: %s\n", strerror (errno));
153	destroy ();
154	return;
155	}
156	}
157
158	socket_ev.poll (socket_ev.poll () & ~PE_W);
159	}
160
161	/******************************************************************************
162	*
163	* Start of read routines.
164	*
165	******************************************************************************/
166
167	int
168	client::next_packet ()
169	{
170	if (inbuf_len >= 2)
171	{
172	int pkt_len = (inbuf [0] << 8) \| inbuf [1];
173
174	if (inbuf_len >= 2 + pkt_len)
175	return 2 + pkt_len;
176
177	if (inbuf_len == sizeof (inbuf))
178	{
179	send_packet_printf ("drawinfo %d input buffer overflow - closing connection.", NDI_RED);
180	destroy ();
181	return -1;
182	}
183	}
184
185	return 0;
186	}
187
188	void
189	client::skip_packet (int len)
190	{
191	inbuf_len -= len;
192	memmove (inbuf, inbuf + len, inbuf_len);
193	}
194
195	/*****************************************************************************
196	* Start of command dispatch area.
197	* The commands here are protocol commands.
198	****************************************************************************/
199
200	// SocketCommand, PlayingCommand, should not exist with those ugly casts
201	#define SC(cb) (void )static_cast<void ()(char , int, client )>(cb),
202	#define PC(cb) (void )static_cast<void ()(char , int, player )>(cb), PF_PLAYER \|
203
204	/**
205	* Dispatch table for the server.
206	*/
207	static struct packet_type packets[] = {
208	{"ncom", PC(NewPlayerCmd) PF_PLAYING \| PF_COMMAND6 },
209	{"command", PC(PlayerCmd) PF_PLAYING \| PF_COMMAND0 },
210
211	{"examine", PC(ExamineCmd) PF_PLAYING },
212	{"ex", PC(ExCmd) PF_PLAYING },
213	{"apply", PC(ApplyCmd) PF_PLAYING },
214	{"lookat", PC(LookAt) PF_PLAYING },
215	{"lock", PC(LockItem) PF_PLAYING },
216	{"mark", PC(MarkItem) PF_PLAYING },
217	{"move", PC(MoveCmd) PF_PLAYING },
218	{"ext", PC(ExtCmd) 0 }, // CF+
219	{"mapredraw", PC(MapRedrawCmd) 0 },
220	{"mapinfo", PC(MapInfoCmd) 0 }, // CF+
221
222	{"reply", SC(ReplyCmd) 0 },
223	{"exti", SC(ExtiCmd) 0 }, // CF+
224	{"addme", SC(AddMeCmd) 0 },
225	{"askface", SC(AskFaceCmd) 0 },
226	{"requestinfo", SC(RequestInfo) 0 },
227	{"setfacemode", SC(SetFaceMode) 0 },
228	{"setsound", SC(SetSound) 0 },
229	{"setup", SC(SetUp) 0 },
230	{"version", SC(VersionCmd) 0 },
231	{"toggleextendedinfos", SC(ToggleExtendedInfos) 0 }, /Added: tchize /
232	{"toggleextendedtext", SC(ToggleExtendedText) 0 }, /Added: tchize /
233	{"asksmooth", SC(AskSmooth) 0 }, /Added: tchize (smoothing technologies) /
234	};
235
236	bool
237	client::may_execute (const packet_type *pkt) const
238	{
239	return (!(pkt->flags & PF_PLAYER) \|\| pl)
240	&& (!(pkt->flags & PF_PLAYING) \|\| state == ST_PLAYING);
241	}
242
243	// HACK: some commands currently should be executed
244	// even when the player is frozen. this hack detects
245	// those commands. it should be folded into may_execute,
246	// but kept seperate to emphasise the hack aspect, i.e.
247	// do it better, then remove.
248	static bool
249	always_immediate (const client ns, const packet_type pkt, const char *data, int len)
250	{
251	if (!(pkt->flags & (PF_COMMAND0 \| PF_COMMAND6)))
252	return false;
253
254	if (!ns->pl \|\| !ns->pl->ob \|\| !ns->pl->ob->map)
255	return false;
256
257	if (pkt->flags & PF_COMMAND6)
258	{
259	data += 6;
260	len -= 6;
261	}
262
263	if (len > 4 && !strncmp (data, "say " , 4))
264	return true;
265	if (len > 5 && !strncmp (data, "chat ", 5))
266	return true;
267
268	return false;
269	}
270
271	void
272	client::execute (const packet_type pkt, char data, int datalen)
273	{
274	if (may_execute (pkt) \|\| always_immediate (this, pkt, data, datalen))
275	{
276	//TODO: only one format
277	if (pkt->flags & PF_PLAYER)
278	((void ()(char , int, player ))pkt->cb)((char )data, datalen, pl);
279	else
280	((void ()(char , int, client ))pkt->cb)((char )data, datalen, this);
281	}
282	else
283	send_packet_printf ("drawinfo %d ERROR: you cannot execute '%s' now.", NDI_RED, pkt->name);
284	}
285
286	bool
287	client::handle_packet ()
288	{
289	int pkt_len = next_packet ();
290
291	if (!pkt_len)
292	return false;
293	else if (pkt_len < 0)
294	{
295	LOG (llevError, "read error on player %s\n",
296	pl && pl->ob ? &pl->ob->name : "[anonymous]");
297	destroy ();
298	return false;
299	}
300
301	inbuf [pkt_len] = 0; /* Terminate buffer - useful for string data */
302
303	/* First, break out beginning word. There are at least
304	* a few commands that do not have any paremeters. If
305	* we get such a command, don't worry about trying
306	* to break it up.
307	*/
308	int datalen;
309	char data = strchr ((char )inbuf + 2, ' ');
310
311	if (data)
312	{
313	*data++ = 0;
314	datalen = pkt_len - (data - (char *)inbuf);
315	}
316	else
317	{
318	data = (char *)inbuf + 2; // better read garbage than segfault
319	datalen = 0;
320	}
321
322	for (packet_type *pkt = packets; pkt < packets + (sizeof (packets) / sizeof (packets[0])); ++pkt)
323	if (!strcmp ((char *)inbuf + 2, pkt->name))
324	{
325	if (pkt->flags & PF_PLAYER && !always_immediate (this, pkt, data, datalen))
326	queue_command (pkt, data, datalen);
327	else
328	execute (pkt, data, datalen);
329
330	goto next_packet;
331	}
332
333	// If we get here, we didn't find a valid command.
334	send_packet_printf ("drawinfo %d ERROR: command '%s' not supported.", NDI_RED, (char *)inbuf + 2);
335	next_packet:
336	skip_packet (pkt_len);
337
338	// input buffer has space again
339	socket_ev.poll (socket_ev.poll () \| PE_R);
340
341	return true;
342	}
343
344	// callback called when socket is either readable or writable
345	void
346	client::socket_cb (iow &w, int got)
347	{
348	//TODO remove when we have better socket cleanup logic
349	if (destroyed ())
350	{
351	socket_ev.poll (0);
352	return;
353	}
354
355	if (got & PE_W)
356	{
357	write_outputbuffer ();
358
359	if (!outputbuffer.len)
360	socket_ev.poll (socket_ev.poll () & ~PE_W);
361	}
362
363	if (got & PE_R)
364	{
365	//TODO: rate-limit tcp connection in better ways, important
366
367	int amount = sizeof (inbuf) - inbuf_len;
368
369	if (!amount)
370	{
371	// input buffer full
372	socket_ev.poll (socket_ev.poll () & ~PE_R);
373	return;
374	}
375
376	amount = read (fd, inbuf + inbuf_len, amount);
377
378	if (!amount)
379	{
380	destroy ();
381	return;
382	}
383	else if (amount < 0)
384	{
385	if (errno != EAGAIN && errno != EINTR)
386	{
387	LOG (llevError, "read error: %s\n", strerror (errno));
388	destroy ();
389	return;
390	}
391
392	// should not be here, normally
393	}
394	else
395	{
396	inbuf_len += amount;
397
398	cmd_ev.start ();
399	}
400	}
401	}
402
403	// called whenever we have additional commands to process
404	void
405	client::cmd_cb (iw &w)
406	{
407	if (handle_packet ())
408	w.start ();
409	else
410	flush ();
411	}
412
413	/*******************************************************************************
414	*
415	* Start of write related routines.
416	*
417	******************************************************************************/
418
419	/**
420	* Adds data to a socket buffer for whatever reason.
421	*
422	* ns is the socket we are adding the data to, buf is the start of the
423	* data, and len is the number of bytes to add.
424	*/
425	void
426	client::send (void *buf_, int len)
427	{
428	char buf = (char )buf_;
429
430	if (destroyed () \|\| !buf)
431	return;
432
433	if (len + outputbuffer.len > SOCKETBUFSIZE)
434	{
435	LOG (llevDebug, "socket on fd %d has overrun internal buffer - marking as dead\n", fd);
436	// shutdown the socket, this is safer than destroying it immediately
437	// as lots of code in the callchain might still access the map etc.
438	shutdown (fd, SHUT_RDWR);
439	return;
440	}
441
442	int avail, end;
443
444	/* data + end is where we start putting the new data. The last byte
445	* currently in use is actually data + end -1
446	*/
447	end = outputbuffer.start + outputbuffer.len;
448	/* The buffer is already in a wrapped state, so adjust end */
449	if (end >= SOCKETBUFSIZE)
450	end -= SOCKETBUFSIZE;
451
452	avail = SOCKETBUFSIZE - end;
453
454	/* We can all fit it behind the current data without wrapping */
455	if (avail >= len)
456	memcpy (outputbuffer.data + end, buf, len);
457	else
458	{
459	memcpy (outputbuffer.data + end, buf, avail);
460	memcpy (outputbuffer.data, buf + avail, len - avail);
461	}
462
463	outputbuffer.len += len;
464	}
465
466	/**
467	* Takes a string of data, and writes it out to the socket. A very handy
468	* shortcut function.
469	*/
470	void
471	client::send_packet (packet &sl)
472	{
473	if (destroyed ())
474	return;
475
476	if (sl.length () >= MAXSOCKBUF)
477	{
478	LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", sl.length ());
479	/* Almost certainly we've overflowed a buffer, so quit now to make
480	* it easier to debug.
481	*/
482	abort ();
483	}
484
485	if (!sl.length ())
486	return;
487
488	assert (sl.hdrlen == 2);
489
490	sl.buf_ [0] = sl.length () >> 8;
491	sl.buf_ [1] = sl.length () ;
492
493	send (sl.buf_, sl.length () + sl.hdrlen);
494	}
495
496	void
497	client::send_packet (const char *buf, int len)
498	{
499	packet sl;
500
501	sl << data (buf, len);
502	send_packet (sl);
503	}
504
505	void
506	client::send_packet (const char *buf)
507	{
508	send_packet (buf, strlen (buf));
509	}
510
511	void
512	client::send_packet_printf (const char *format, ...)
513	{
514	packet sl;
515
516	va_list ap;
517	va_start (ap, format);
518	sl.vprintf (format, ap);
519	va_end (ap);
520
521	send_packet (sl);
522	}
523
524	void
525	client::send_drawinfo (const char *msg, int flags)
526	{
527	send_packet_printf ("drawinfo %d %s", flags, msg);
528	}
529
530	void
531	client::send_msg (int color, const char type, const char msg)
532	{
533	if (can_msg)
534	send_packet_printf ("msg %d %s %s", color, type, msg);
535	else if (color < 0)
536	return; // client cannot handle this
537	else if (strchr (msg, '<') \|\| strchr (msg, '&'))
538	{
539	//TODO: should escape/modify to old syntax
540	send_packet_printf ("drawinfo %d %s", color, msg);
541	}
542	else
543	send_packet_printf ("drawinfo %d %s", color, msg);
544	}
545
546	/***********************************************************************
547	*
548	* packet functions/utilities
549	*
550	**********************************************************************/
551
552	packet::packet (const char *name)
553	{
554	reset ();
555
556	int len = strlen (name);
557	memcpy (cur, name, len); cur += len;
558	*cur++ = ' ';
559	}
560
561	packet &packet::operator <<(const ber32 v)
562	{
563	enum { maxlen = 32 / 7 + 1};
564	uint8 buf[maxlen];
565	uint8 *p = buf + maxlen;
566	uint32 val = v.val;
567
568	*--p = val & 0x7F;
569
570	while (val > 0x7F)
571	{
572	val >>= 7;
573	*--p = (val & 0x7F) \| 0x80;
574	}
575
576	return *this << data (p, buf + maxlen - p);
577	}
578
579	packet &packet::operator <<(const data &v)
580	{
581	if (room () < v.len)
582	reset ();
583	else
584	{
585	if (v.len)
586	{
587	memcpy (cur, v.ptr, v.len);
588	cur += v.len;
589	}
590	}
591
592	return *this;
593	}
594
595	packet &packet::operator <<(const data8 &v)
596	{
597	unsigned int len = min (v.len, 0x00FF);
598	return *this << uint8 (len) << data (v.ptr, len);
599	}
600
601	packet &packet::operator <<(const data16 &v)
602	{
603	unsigned int len = min (v.len, 0xFFFF);
604	return *this << uint16 (len) << data (v.ptr, len);
605	}
606
607	packet &packet::operator <<(const char *v)
608	{
609	return *this << data (v, strlen (v ? v : 0));
610	}
611
612	void
613	packet::vprintf (const char *format, va_list ap)
614	{
615	int size = room ();
616
617	int len = vsnprintf ((char *)cur, size, format, ap);
618
619	if (len >= size)
620	return reset ();
621
622	cur += len;
623	}
624