server/socket/lowlevel.C

/*
 * CrossFire, A Multiplayer game for X-windows
 * 
 * Copyright (C) 2005, 2006, 2007 Marc Lehmann & Crossfire+ Development Team
 * 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 ()
{
  if (destroyed ())
    return;

#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 | PF_COMMAND6 },
  {"command",     PC(PlayerCmd)    PF_PLAYING | PF_COMMAND0 },

  {"examine",     PC(ExamineCmd)   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 },       /* Added: phil */
  {"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;

          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_;

  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);
}

/***********************************************************************
 *
 * 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;
}

/******************************************************************************
 *
 * 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:	1.38
Committed:	Tue Apr 3 00:21:38 2007 UTC (17 years, 1 month ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.37:	+3 -3 lines
Log Message:	- fix ber encoding - reduce image checksum length to 6 bytes (from 16) - implement fx packet, which reduces face overhead to amortised 10/12 bytes per face instead of 21/32 bytes and allows an unlimited number of faces instead of 2**16.
#	Content
1	/*
2	* CrossFire, A Multiplayer game for X-windows
3	*
4	* Copyright (C) 2005, 2006, 2007 Marc Lehmann & Crossfire+ Development Team
5	* Copyright (C) 1992 Frank Tore Johansen
6	*
7	* This program is free software; you can redistribute it and/or modify
8	* it under the terms of the GNU General Public License as published by
9	* the Free Software Foundation; either version 2 of the License, or
10	* (at your option) any later version.
11	*
12	* This program is distributed in the hope that it will be useful,
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15	* GNU General Public License for more details.
16	*
17	* You should have received a copy of the GNU General Public License
18	* along with this program; if not, write to the Free Software
19	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20	*
21	* The author can be reached via e-mail to mark@pyramid.com
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	// 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 * 1000
52	#define SOCKET_TIMEOUT2 20 * 1000
53
54	void
55	client::flush ()
56	{
57	if (destroyed ())
58	return;
59
60	#ifdef __linux__
61	// check time of last ack, and, if too old, kill connection
62	struct tcp_info tcpi;
63	socklen_t len = sizeof (tcpi);
64
65	if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
66	{
67	unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;
68
69	rtt = tcpi.tcpi_rtt;
70	rttvar = tcpi.tcpi_rttvar;
71
72	if (tcpi.tcpi_unacked && SOCKET_TIMEOUT1 < diff && diff < 0x80000000UL // ack delayed for 20s
73	&& SOCKET_TIMEOUT2 < tcpi.tcpi_last_data_sent) // no data sent for 10s
74	{
75	LOG (llevDebug, "Connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
76	(unsigned) tcpi.tcpi_last_ack_recv, (unsigned) tcpi.tcpi_last_data_sent, (unsigned) tcpi.tcpi_unacked);
77	destroy ();
78	}
79	}
80	#endif
81
82	/**
83	* Writes data to socket.
84	*
85	* When the socket is clear to write, and we have backlogged data, this
86	* is called to write it out.
87	*/
88
89	if (!outputbuffer.len \|\| socket_ev.poll () & PE_W)
90	return;
91
92	write_outputbuffer ();
93	}
94
95	void
96	client::write_outputbuffer ()
97	{
98	while (outputbuffer.len)
99	{
100	int res = write (fd, outputbuffer.data + outputbuffer.start,
101	min (outputbuffer.len, SOCKETBUFSIZE - outputbuffer.start));
102
103	if (res > 0)
104	{
105	outputbuffer.start += res;
106	/* wrap back to start of buffer */
107	if (outputbuffer.start == SOCKETBUFSIZE)
108	outputbuffer.start = 0;
109
110	outputbuffer.len -= res;
111	#ifdef CS_LOGSTATS
112	cst_tot.obytes += res;
113	cst_lst.obytes += res;
114	#endif
115	}
116	else if (res == 0)
117	{
118	LOG (llevError, "socket write failed, connection closed.\n");
119	destroy ();
120	return;
121	}
122	else if (errno == EINTR)
123	{
124	// just retry
125	}
126	else if (errno == EAGAIN)
127	{
128	// delay till ready
129	socket_ev.poll (socket_ev.poll () \| PE_W);
130	socket_ev.start ();
131	return;
132	}
133	else
134	{
135	LOG (llevError, "socket write failed: %s\n", strerror (errno));
136	destroy ();
137	return;
138	}
139	}
140
141	socket_ev.poll (socket_ev.poll () & ~PE_W);
142	}
143
144	/******************************************************************************
145	*
146	* Start of read routines.
147	*
148	******************************************************************************/
149
150	int
151	client::next_packet ()
152	{
153	if (inbuf_len >= 2)
154	{
155	int pkt_len = (inbuf [0] << 8) \| inbuf [1];
156
157	if (inbuf_len >= 2 + pkt_len)
158	return 2 + pkt_len;
159
160	if (inbuf_len == sizeof (inbuf))
161	{
162	send_packet_printf ("drawinfo %d input buffer overflow - closing connection.", NDI_RED);
163	destroy ();
164	return -1;
165	}
166	}
167
168	return 0;
169	}
170
171	void
172	client::skip_packet (int len)
173	{
174	inbuf_len -= len;
175	memmove (inbuf, inbuf + len, inbuf_len);
176	}
177
178	/*****************************************************************************
179	* Start of command dispatch area.
180	* The commands here are protocol commands.
181	****************************************************************************/
182
183	// SocketCommand, PlayingCommand, should not exist with those ugly casts
184	#define SC(cb) (void )static_cast<void ()(char , int, client )>(cb),
185	#define PC(cb) (void )static_cast<void ()(char , int, player )>(cb), PF_PLAYER \|
186
187	/**
188	* Dispatch table for the server.
189	*/
190	static struct packet_type packets[] = {
191	{"ncom", PC(NewPlayerCmd) PF_PLAYING \| PF_COMMAND6 },
192	{"command", PC(PlayerCmd) PF_PLAYING \| PF_COMMAND0 },
193
194	{"examine", PC(ExamineCmd) PF_PLAYING },
195	{"apply", PC(ApplyCmd) PF_PLAYING },
196	{"lookat", PC(LookAt) PF_PLAYING },
197	{"lock", PC(LockItem) PF_PLAYING },
198	{"mark", PC(MarkItem) PF_PLAYING },
199	{"move", PC(MoveCmd) PF_PLAYING },
200	{"ext", PC(ExtCmd) 0 }, /* CF+ */
201	{"mapredraw", PC(MapRedrawCmd) 0 }, /* Added: phil */
202	{"mapinfo", PC(MapInfoCmd) 0 }, /* CF+ */
203
204	{"reply", SC(ReplyCmd) 0 },
205	{"exti", SC(ExtiCmd) 0 }, /* CF+ */
206	{"addme", SC(AddMeCmd) 0 },
207	{"askface", SC(AskFaceCmd) 0 },
208	{"requestinfo", SC(RequestInfo) 0 },
209	{"setfacemode", SC(SetFaceMode) 0 },
210	{"setsound", SC(SetSound) 0 },
211	{"setup", SC(SetUp) 0 },
212	{"version", SC(VersionCmd) 0 },
213	{"toggleextendedinfos", SC(ToggleExtendedInfos) 0 }, /Added: tchize /
214	{"toggleextendedtext", SC(ToggleExtendedText) 0 }, /Added: tchize /
215	{"asksmooth", SC(AskSmooth) 0 }, /Added: tchize (smoothing technologies) /
216	};
217
218	bool
219	client::may_execute (const packet_type *pkt) const
220	{
221	return (!(pkt->flags & PF_PLAYER) \|\| pl)
222	&& (!(pkt->flags & PF_PLAYING) \|\| state == ST_PLAYING);
223	}
224
225	// HACK: some commands currently should be executed
226	// even when the player is frozen. this hack detects
227	// those commands. it should be folded into may_execute,
228	// but kept seperate to emphasise the hack aspect, i.e.
229	// do it better, then remove.
230	static bool
231	always_immediate (const client ns, const packet_type pkt, const char *data, int len)
232	{
233	if (!(pkt->flags & (PF_COMMAND0 \| PF_COMMAND6)))
234	return false;
235
236	if (!ns->pl \|\| !ns->pl->ob \|\| !ns->pl->ob->map)
237	return false;
238
239	if (pkt->flags & PF_COMMAND6)
240	{
241	data += 6;
242	len -= 6;
243	}
244
245	if (len > 4 && !strncmp (data, "say " , 4))
246	return true;
247	if (len > 5 && !strncmp (data, "chat ", 5))
248	return true;
249
250	return false;
251	}
252
253	void
254	client::execute (const packet_type pkt, char data, int datalen)
255	{
256	if (may_execute (pkt) \|\| always_immediate (this, pkt, data, datalen))
257	{
258	//TODO: only one format
259	if (pkt->flags & PF_PLAYER)
260	((void ()(char , int, player ))pkt->cb)((char )data, datalen, pl);
261	else
262	((void ()(char , int, client ))pkt->cb)((char )data, datalen, this);
263	}
264	else
265	send_packet_printf ("drawinfo %d ERROR: you cannot execute '%s' now.", NDI_RED, pkt->name);
266	}
267
268	bool
269	client::handle_packet ()
270	{
271	int pkt_len = next_packet ();
272
273	if (!pkt_len)
274	return false;
275	else if (pkt_len < 0)
276	{
277	LOG (llevError, "read error on player %s\n",
278	pl && pl->ob ? &pl->ob->name : "[anonymous]");
279	destroy ();
280	return false;
281	}
282
283	inbuf [pkt_len] = 0; /* Terminate buffer - useful for string data */
284
285	/* First, break out beginning word. There are at least
286	* a few commands that do not have any paremeters. If
287	* we get such a command, don't worry about trying
288	* to break it up.
289	*/
290	int datalen;
291	char data = strchr ((char )inbuf + 2, ' ');
292
293	if (data)
294	{
295	*data++ = 0;
296	datalen = pkt_len - (data - (char *)inbuf);
297	}
298	else
299	{
300	data = (char *)inbuf + 2; // better read garbage than segfault
301	datalen = 0;
302	}
303
304	for (packet_type *pkt = packets; pkt < packets + (sizeof (packets) / sizeof (packets[0])); ++pkt)
305	if (!strcmp ((char *)inbuf + 2, pkt->name))
306	{
307	if (pkt->flags & PF_PLAYER && !always_immediate (this, pkt, data, datalen))
308	queue_command (pkt, data, datalen);
309	else
310	execute (pkt, data, datalen);
311
312	goto next_packet;
313	}
314
315	// If we get here, we didn't find a valid command.
316	send_packet_printf ("drawinfo %d ERROR: command '%s' not supported.", NDI_RED, (char *)inbuf + 2);
317	next_packet:
318	skip_packet (pkt_len);
319
320	// input buffer has space again
321	socket_ev.poll (socket_ev.poll () \| PE_R);
322
323	return true;
324	}
325
326	// callback called when socket is either readable or writable
327	void
328	client::socket_cb (iow &w, int got)
329	{
330	//TODO remove when we have better socket cleanup logic
331	if (destroyed ())
332	{
333	socket_ev.poll (0);
334	return;
335	}
336
337	if (got & PE_W)
338	{
339	write_outputbuffer ();
340
341	if (!outputbuffer.len)
342	socket_ev.poll (socket_ev.poll () & ~PE_W);
343	}
344
345	if (got & PE_R)
346	{
347	//TODO: rate-limit tcp connection in better ways, important
348
349	int amount = sizeof (inbuf) - inbuf_len;
350
351	if (!amount)
352	{
353	// input buffer full
354	socket_ev.poll (socket_ev.poll () & ~PE_R);
355	return;
356	}
357
358	amount = read (fd, inbuf + inbuf_len, amount);
359
360	if (!amount)
361	{
362	destroy ();
363	return;
364	}
365	else if (amount < 0)
366	{
367	if (errno != EAGAIN && errno != EINTR)
368	{
369	LOG (llevError, "read error: %s\n", strerror (errno));
370	destroy ();
371	return;
372	}
373
374	// should not be here, normally
375	}
376	else
377	{
378	inbuf_len += amount;
379
380	cst_tot.ibytes += amount;
381	cst_lst.ibytes += amount;
382
383	cmd_ev.start ();
384	}
385	}
386	}
387
388	// called whenever we have additional commands to process
389	void
390	client::cmd_cb (iw &w)
391	{
392	if (handle_packet ())
393	w.start ();
394	else
395	flush ();
396	}
397
398	/*******************************************************************************
399	*
400	* Start of write related routines.
401	*
402	******************************************************************************/
403
404	/**
405	* Adds data to a socket buffer for whatever reason.
406	*
407	* ns is the socket we are adding the data to, buf is the start of the
408	* data, and len is the number of bytes to add.
409	*/
410	void
411	client::send (void *buf_, int len)
412	{
413	char buf = (char )buf_;
414
415	if (destroyed () \|\| !buf)
416	return;
417
418	if (len + outputbuffer.len > SOCKETBUFSIZE)
419	{
420	LOG (llevDebug, "socket on fd %d has overrun internal buffer - marking as dead\n", fd);
421	// shutdown the socket, this is safer than destroying it immediately
422	// as lots of code in the callchain might still access the map etc.
423	shutdown (fd, SHUT_RDWR);
424	return;
425	}
426
427	int avail, end;
428
429	/* data + end is where we start putting the new data. The last byte
430	* currently in use is actually data + end -1
431	*/
432	end = outputbuffer.start + outputbuffer.len;
433	/* The buffer is already in a wrapped state, so adjust end */
434	if (end >= SOCKETBUFSIZE)
435	end -= SOCKETBUFSIZE;
436
437	avail = SOCKETBUFSIZE - end;
438
439	/* We can all fit it behind the current data without wrapping */
440	if (avail >= len)
441	memcpy (outputbuffer.data + end, buf, len);
442	else
443	{
444	memcpy (outputbuffer.data + end, buf, avail);
445	memcpy (outputbuffer.data, buf + avail, len - avail);
446	}
447
448	outputbuffer.len += len;
449	}
450
451	/**
452	* Takes a string of data, and writes it out to the socket. A very handy
453	* shortcut function.
454	*/
455	void
456	client::send_packet (packet &sl)
457	{
458	if (destroyed ())
459	return;
460
461	if (sl.length () >= MAXSOCKBUF)
462	{
463	LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", sl.length ());
464	/* Almost certainly we've overflowed a buffer, so quit now to make
465	* it easier to debug.
466	*/
467	abort ();
468	}
469
470	if (!sl.length ())
471	return;
472
473	assert (sl.hdrlen == 2);
474
475	sl.buf_ [0] = sl.length () >> 8;
476	sl.buf_ [1] = sl.length () ;
477
478	send (sl.buf_, sl.length () + sl.hdrlen);
479	}
480
481	void
482	client::send_packet (const char *buf, int len)
483	{
484	packet sl;
485
486	sl << data (buf, len);
487	send_packet (sl);
488	}
489
490	void
491	client::send_packet (const char *buf)
492	{
493	send_packet (buf, strlen (buf));
494	}
495
496	void
497	client::send_packet_printf (const char *format, ...)
498	{
499	packet sl;
500
501	va_list ap;
502	va_start (ap, format);
503	sl.vprintf (format, ap);
504	va_end (ap);
505
506	send_packet (sl);
507	}
508
509	void
510	client::send_drawinfo (const char *msg, int flags)
511	{
512	send_packet_printf ("drawinfo %d %s", flags, msg);
513	}
514
515	/***********************************************************************
516	*
517	* packet functions/utilities
518	*
519	**********************************************************************/
520
521	packet::packet (const char *name)
522	{
523	reset ();
524
525	int len = strlen (name);
526	memcpy (cur, name, len); cur += len;
527	*cur++ = ' ';
528	}
529
530	packet &packet::operator <<(const ber32 v)
531	{
532	enum { maxlen = 32 / 7 + 1};
533	uint8 buf[maxlen];
534	uint8 *p = buf + maxlen;
535	uint32 val = v.val;
536
537	*--p = val & 0x7F;
538
539	while (val > 0x7F)
540	{
541	val >>= 7;
542	*--p = (val & 0x7F) \| 0x80;
543	}
544
545	return *this << data (p, buf + maxlen - p);
546	}
547
548	packet &packet::operator <<(const data &v)
549	{
550	if (room () < v.len)
551	reset ();
552	else
553	{
554	if (v.len)
555	{
556	memcpy (cur, v.ptr, v.len);
557	cur += v.len;
558	}
559	}
560
561	return *this;
562	}
563
564	packet &packet::operator <<(const data8 &v)
565	{
566	unsigned int len = min (v.len, 0x00FF);
567	return *this << uint8 (len) << data (v.ptr, len);
568	}
569
570	packet &packet::operator <<(const data16 &v)
571	{
572	unsigned int len = min (v.len, 0xFFFF);
573	return *this << uint16 (len) << data (v.ptr, len);
574	}
575
576	packet &packet::operator <<(const char *v)
577	{
578	return *this << data (v, strlen (v ? v : 0));
579	}
580
581	void
582	packet::vprintf (const char *format, va_list ap)
583	{
584	int size = room ();
585
586	int len = vsnprintf ((char *)cur, size, format, ap);
587
588	if (len >= size)
589	return reset ();
590
591	cur += len;
592	}
593
594	/******************************************************************************
595	*
596	* statistics logging functions.
597	*
598	******************************************************************************/
599
600	#ifdef CS_LOGSTATS
601
602	/* cst_tot is for the life of the server, cst_last is for the last series of
603	* stats
604	*/
605	CS_Stats cst_tot, cst_lst;
606
607	/**
608	* Writes out the gathered stats. We clear cst_lst.
609	*/
610	void
611	write_cs_stats (void)
612	{
613	time_t now = time (NULL);
614
615	/* If no connections recently, don't both to log anything */
616	if (cst_lst.ibytes == 0 && cst_lst.obytes == 0)
617	return;
618
619	/* CSSTAT is put in so scripts can easily find the line */
620	LOG (llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
621	ctime (&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
622	now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes, cst_lst.max_conn, now - cst_lst.time_start);
623	cst_lst.ibytes = 0;
624	cst_lst.obytes = 0;
625	cst_lst.time_start = now;
626	}
627	#endif
628