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/cvs/deliantra/server/socket/lowlevel.C
Revision: 1.50
Committed: Thu Jul 12 19:36:58 2007 UTC (16 years, 10 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.49: +14 -0 lines
Log Message:
try a very simple method of failsafe-bandweidthing by not sending any data when the socket buffer could not be drained in the last tick

File Contents

# Content
1 /*
2 * This file is part of Crossfire TRT, the Roguelike Realtime MORPG.
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
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 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, see <http://www.gnu.org/licenses/>.
19 *
20 * The authors can be reached via e-mail to <crossfire@schmorp.de>
21 */
22
23 using namespace std;
24
25 #include <global.h>
26 #include <sproto.h>
27 #include <cstdarg>
28
29 #if HAVE_TCP_INFO
30 # include <sys/types.h>
31 # include <sys/socket.h>
32 # include <netinet/in.h>
33 # include <netinet/tcp.h>
34 #endif
35
36 #define HAVE_SIOCOUTQ 1 //TODO configure.ac support
37 #if HAVE_SIOCOUTQ
38 # include <linux/sockios.h>
39 #endif
40
41 // disconnect a socket after this many seconds without an ack
42 #define SOCKET_TIMEOUT 8.
43
44 // force a packet when idle for more than this many seconds,
45 // forcing an ack regularly.
46 #define IDLE_PING 2.
47
48 void
49 client::flush ()
50 {
51 if (destroyed ())
52 return;
53
54 # if HAVE_SIOCOUTQ
55 {
56 int value;
57
58 if (!ioctl (fd, SIOCOUTQ, &value))
59 outq = value;
60 }
61 # endif
62
63 #if HAVE_TCP_INFO
64 // check about once per second, spread evenly over all clients
65 // do this only when player is active
66 if (!((pticks + fd) & 7) && pl && pl->active)
67 {
68 // check time of last ack, and, if too old, kill connection
69 struct tcp_info tcpi;
70 socklen_t len = sizeof (tcpi);
71
72 if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
73 {
74 if (tcpi.tcpi_snd_mss)
75 mss = tcpi.tcpi_snd_mss;
76
77 rtt = tcpi.tcpi_rtt;
78 rttvar = tcpi.tcpi_rttvar;
79
80 if (tcpi.tcpi_last_ack_recv > int (SOCKET_TIMEOUT * 1000))
81 {
82 send_msg (NDI_RED, "connection-timeout", "safety disconnect due to tcp/ip timeout (no packets received)");
83 write_outputbuffer ();
84
85 LOG (llevDebug, "connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
86 (unsigned)tcpi.tcpi_last_ack_recv, (unsigned)tcpi.tcpi_last_data_sent, (unsigned)tcpi.tcpi_unacked);
87 destroy ();
88 }
89 }
90 }
91 #endif
92
93 /**
94 * Writes data to socket.
95 *
96 * When the socket is clear to write, and we have backlogged data, this
97 * is called to write it out.
98 */
99
100 // write a nop to the socket at least every IDLE_NOP seconds.
101 if (!outputbuffer.len)
102 {
103 if (last_send + IDLE_PING <= NOW && pl && pl->active)
104 {
105 // this is a bit ugly, but map1/map1a seem to be the only
106 // nop'able commands and they are quite small.
107 packet sl (mapmode == Map1Cmd ? "map1" : "map1a");
108 send_packet (sl);
109 }
110 else
111 return;
112 }
113
114 if (socket_ev.poll () & PE_W)
115 return;
116
117 last_send = NOW;
118 write_outputbuffer ();
119 }
120
121 void
122 client::write_outputbuffer ()
123 {
124 while (outputbuffer.len)
125 {
126 int res = write (fd, outputbuffer.data + outputbuffer.start,
127 min (outputbuffer.len, SOCKETBUFSIZE - outputbuffer.start));
128
129 if (res > 0)
130 {
131 outputbuffer.start += res;
132 /* wrap back to start of buffer */
133 if (outputbuffer.start == SOCKETBUFSIZE)
134 outputbuffer.start = 0;
135
136 outputbuffer.len -= res;
137 }
138 else if (res == 0)
139 {
140 LOG (llevError, "socket write failed, connection closed.\n");
141 destroy ();
142 return;
143 }
144 else if (errno == EINTR)
145 {
146 // just retry
147 }
148 else if (errno == EAGAIN)
149 {
150 // delay till ready
151 socket_ev.poll (socket_ev.poll () | PE_W);
152 socket_ev.start ();
153 return;
154 }
155 else
156 {
157 LOG (llevError, "socket write failed: %s\n", strerror (errno));
158 destroy ();
159 return;
160 }
161 }
162
163 socket_ev.poll (socket_ev.poll () & ~PE_W);
164 }
165
166 /******************************************************************************
167 *
168 * Start of read routines.
169 *
170 ******************************************************************************/
171
172 int
173 client::next_packet ()
174 {
175 if (inbuf_len >= 2)
176 {
177 int pkt_len = (inbuf [0] << 8) | inbuf [1];
178
179 if (inbuf_len >= 2 + pkt_len)
180 return 2 + pkt_len;
181
182 if (inbuf_len == sizeof (inbuf))
183 {
184 send_packet_printf ("drawinfo %d input buffer overflow - closing connection.", NDI_RED);
185 destroy ();
186 return -1;
187 }
188 }
189
190 return 0;
191 }
192
193 void
194 client::skip_packet (int len)
195 {
196 inbuf_len -= len;
197 memmove (inbuf, inbuf + len, inbuf_len);
198 }
199
200 /*****************************************************************************
201 * Start of command dispatch area.
202 * The commands here are protocol commands.
203 ****************************************************************************/
204
205 // SocketCommand, PlayingCommand, should not exist with those ugly casts
206 #define SC(cb) (void *)static_cast<void (*)(char *, int, client *)>(cb),
207 #define PC(cb) (void *)static_cast<void (*)(char *, int, player *)>(cb), PF_PLAYER |
208
209 /**
210 * Dispatch table for the server.
211 */
212 static struct packet_type packets[] = {
213 {"ncom", PC(NewPlayerCmd) PF_PLAYING | PF_COMMAND6 },
214 {"command", PC(PlayerCmd) PF_PLAYING | PF_COMMAND0 },
215
216 {"examine", PC(ExamineCmd) PF_PLAYING },
217 {"ex", PC(ExCmd) PF_PLAYING },
218 {"apply", PC(ApplyCmd) PF_PLAYING },
219 {"lookat", PC(LookAt) PF_PLAYING },
220 {"lock", PC(LockItem) PF_PLAYING },
221 {"mark", PC(MarkItem) PF_PLAYING },
222 {"move", PC(MoveCmd) PF_PLAYING },
223 {"ext", PC(ExtCmd) 0 }, // CF+
224 {"mapredraw", PC(MapRedrawCmd) 0 },
225 {"mapinfo", PC(MapInfoCmd) 0 }, // CF+
226
227 {"reply", SC(ReplyCmd) 0 },
228 {"exti", SC(ExtiCmd) 0 }, // CF+
229 {"addme", SC(AddMeCmd) 0 },
230 {"askface", SC(AskFaceCmd) 0 },
231 {"requestinfo", SC(RequestInfo) 0 },
232 {"setfacemode", SC(SetFaceMode) 0 },
233 {"setsound", SC(SetSound) 0 },
234 {"setup", SC(SetUp) 0 },
235 {"version", SC(VersionCmd) 0 },
236 {"toggleextendedinfos", SC(ToggleExtendedInfos) 0 }, /*Added: tchize */
237 {"toggleextendedtext", SC(ToggleExtendedText) 0 }, /*Added: tchize */
238 {"asksmooth", SC(AskSmooth) 0 }, /*Added: tchize (smoothing technologies) */
239 };
240
241 bool
242 client::may_execute (const packet_type *pkt) const
243 {
244 return (!(pkt->flags & PF_PLAYER) || pl)
245 && (!(pkt->flags & PF_PLAYING) || state == ST_PLAYING);
246 }
247
248 // HACK: some commands currently should be executed
249 // even when the player is frozen. this hack detects
250 // those commands. it should be folded into may_execute,
251 // but kept seperate to emphasise the hack aspect, i.e.
252 // do it better, then remove.
253 static bool
254 always_immediate (const client *ns, const packet_type *pkt, const char *data, int len)
255 {
256 if (!(pkt->flags & (PF_COMMAND0 | PF_COMMAND6)))
257 return false;
258
259 if (!ns->pl || !ns->pl->ob || !ns->pl->ob->map)
260 return false;
261
262 if (pkt->flags & PF_COMMAND6)
263 {
264 data += 6;
265 len -= 6;
266 }
267
268 if (len > 4 && !strncmp (data, "say " , 4))
269 return true;
270 if (len > 5 && !strncmp (data, "chat ", 5))
271 return true;
272
273 return false;
274 }
275
276 void
277 client::execute (const packet_type *pkt, char *data, int datalen)
278 {
279 if (may_execute (pkt) || always_immediate (this, pkt, data, datalen))
280 {
281 //TODO: only one format
282 if (pkt->flags & PF_PLAYER)
283 ((void (*)(char *, int, player *))pkt->cb)((char *)data, datalen, pl);
284 else
285 ((void (*)(char *, int, client *))pkt->cb)((char *)data, datalen, this);
286 }
287 else
288 send_packet_printf ("drawinfo %d ERROR: you cannot execute '%s' now.", NDI_RED, pkt->name);
289 }
290
291 bool
292 client::handle_packet ()
293 {
294 int pkt_len = next_packet ();
295
296 if (!pkt_len)
297 return false;
298 else if (pkt_len < 0)
299 {
300 LOG (llevError, "read error on player %s\n",
301 pl && pl->ob ? &pl->ob->name : "[anonymous]");
302 destroy ();
303 return false;
304 }
305
306 inbuf [pkt_len] = 0; /* Terminate buffer - useful for string data */
307
308 /* First, break out beginning word. There are at least
309 * a few commands that do not have any paremeters. If
310 * we get such a command, don't worry about trying
311 * to break it up.
312 */
313 int datalen;
314 char *data = strchr ((char *)inbuf + 2, ' ');
315
316 if (data)
317 {
318 *data++ = 0;
319 datalen = pkt_len - (data - (char *)inbuf);
320 }
321 else
322 {
323 data = (char *)inbuf + 2; // better read garbage than segfault
324 datalen = 0;
325 }
326
327 for (packet_type *pkt = packets; pkt < packets + (sizeof (packets) / sizeof (packets[0])); ++pkt)
328 if (!strcmp ((char *)inbuf + 2, pkt->name))
329 {
330 if (pkt->flags & PF_PLAYER && !always_immediate (this, pkt, data, datalen))
331 queue_command (pkt, data, datalen);
332 else
333 execute (pkt, data, datalen);
334
335 goto next_packet;
336 }
337
338 // If we get here, we didn't find a valid command.
339 send_packet_printf ("drawinfo %d ERROR: command '%s' not supported.", NDI_RED, (char *)inbuf + 2);
340 next_packet:
341 skip_packet (pkt_len);
342
343 // input buffer has space again
344 socket_ev.poll (socket_ev.poll () | PE_R);
345
346 return true;
347 }
348
349 // callback called when socket is either readable or writable
350 void
351 client::socket_cb (iow &w, int got)
352 {
353 //TODO remove when we have better socket cleanup logic
354 if (destroyed ())
355 {
356 socket_ev.poll (0);
357 return;
358 }
359
360 if (got & PE_W)
361 {
362 write_outputbuffer ();
363
364 if (!outputbuffer.len)
365 socket_ev.poll (socket_ev.poll () & ~PE_W);
366 }
367
368 if (got & PE_R)
369 {
370 //TODO: rate-limit tcp connection in better ways, important
371
372 int amount = sizeof (inbuf) - inbuf_len;
373
374 if (!amount)
375 {
376 // input buffer full
377 socket_ev.poll (socket_ev.poll () & ~PE_R);
378 return;
379 }
380
381 amount = read (fd, inbuf + inbuf_len, amount);
382
383 if (!amount)
384 {
385 destroy ();
386 return;
387 }
388 else if (amount < 0)
389 {
390 if (errno != EAGAIN && errno != EINTR)
391 {
392 LOG (llevError, "read error: %s\n", strerror (errno));
393 destroy ();
394 return;
395 }
396
397 // should not be here, normally
398 }
399 else
400 {
401 inbuf_len += amount;
402
403 cmd_ev.start ();
404 }
405 }
406 }
407
408 // called whenever we have additional commands to process
409 void
410 client::cmd_cb (iw &w)
411 {
412 if (handle_packet ())
413 w.start ();
414 else
415 flush ();
416 }
417
418 /*******************************************************************************
419 *
420 * Start of write related routines.
421 *
422 ******************************************************************************/
423
424 /**
425 * Adds data to a socket buffer for whatever reason.
426 *
427 * ns is the socket we are adding the data to, buf is the start of the
428 * data, and len is the number of bytes to add.
429 */
430 void
431 client::send (void *buf_, int len)
432 {
433 char *buf = (char *)buf_;
434
435 if (destroyed () || !buf)
436 return;
437
438 if (len + outputbuffer.len > SOCKETBUFSIZE)
439 {
440 LOG (llevDebug, "socket on fd %d has overrun internal buffer - marking as dead\n", fd);
441 // shutdown the socket, this is safer than destroying it immediately
442 // as lots of code in the callchain might still access the map etc.
443 shutdown (fd, SHUT_RDWR);
444 return;
445 }
446
447 int avail, end;
448
449 /* data + end is where we start putting the new data. The last byte
450 * currently in use is actually data + end -1
451 */
452 end = outputbuffer.start + outputbuffer.len;
453 /* The buffer is already in a wrapped state, so adjust end */
454 if (end >= SOCKETBUFSIZE)
455 end -= SOCKETBUFSIZE;
456
457 avail = SOCKETBUFSIZE - end;
458
459 /* We can all fit it behind the current data without wrapping */
460 if (avail >= len)
461 memcpy (outputbuffer.data + end, buf, len);
462 else
463 {
464 memcpy (outputbuffer.data + end, buf, avail);
465 memcpy (outputbuffer.data, buf + avail, len - avail);
466 }
467
468 outputbuffer.len += len;
469 }
470
471 /**
472 * Takes a string of data, and writes it out to the socket. A very handy
473 * shortcut function.
474 */
475 void
476 client::send_packet (packet &sl)
477 {
478 if (destroyed ())
479 return;
480
481 if (sl.length () >= MAXSOCKBUF)
482 {
483 LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", sl.length ());
484 /* Almost certainly we've overflowed a buffer, so quit now to make
485 * it easier to debug.
486 */
487 abort ();
488 }
489
490 if (!sl.length ())
491 return;
492
493 assert (sl.hdrlen == 2);
494
495 sl.buf_ [0] = sl.length () >> 8;
496 sl.buf_ [1] = sl.length () ;
497
498 send (sl.buf_, sl.length () + sl.hdrlen);
499 }
500
501 void
502 client::send_packet (const char *buf, int len)
503 {
504 packet sl;
505
506 sl << data (buf, len);
507 send_packet (sl);
508 }
509
510 void
511 client::send_packet (const char *buf)
512 {
513 send_packet (buf, strlen (buf));
514 }
515
516 void
517 client::send_packet_printf (const char *format, ...)
518 {
519 packet sl;
520
521 va_list ap;
522 va_start (ap, format);
523 sl.vprintf (format, ap);
524 va_end (ap);
525
526 send_packet (sl);
527 }
528
529 // returns true when the message needs special (read: perl) treatment
530 static bool
531 msg_is_special (const char *msg)
532 {
533 return msg [strcspn (msg, "<[&\n")];
534 }
535
536 void
537 client::send_msg (int color, const char *type, const char *msg)
538 {
539 if (msg_is_special (msg))
540 cfperl_send_msg (this, color, type, msg);
541 else if (can_msg)
542 send_packet_printf ("msg %d %s %s", color, type, msg);
543 else if (color < 0)
544 return; // client cannot handle this
545 else
546 send_packet_printf ("drawinfo %d %s", color, msg);
547 }
548
549 void
550 client::send_drawinfo (const char *msg, int flags)
551 {
552 send_msg (flags, "log", msg);
553 }
554
555 /***********************************************************************
556 *
557 * packet functions/utilities
558 *
559 **********************************************************************/
560
561 packet::packet (const char *name)
562 {
563 reset ();
564
565 int len = strlen (name);
566 memcpy (cur, name, len); cur += len;
567 *cur++ = ' ';
568 }
569
570 packet &packet::operator <<(const ber32 v)
571 {
572 enum { maxlen = 32 / 7 + 1};
573 uint8 buf[maxlen];
574 uint8 *p = buf + maxlen;
575 uint32 val = v.val;
576
577 *--p = val & 0x7F;
578
579 while (val > 0x7F)
580 {
581 val >>= 7;
582 *--p = (val & 0x7F) | 0x80;
583 }
584
585 return *this << data (p, buf + maxlen - p);
586 }
587
588 packet &packet::operator <<(const data &v)
589 {
590 if (room () < v.len)
591 reset ();
592 else
593 {
594 if (v.len)
595 {
596 memcpy (cur, v.ptr, v.len);
597 cur += v.len;
598 }
599 }
600
601 return *this;
602 }
603
604 packet &packet::operator <<(const data8 &v)
605 {
606 unsigned int len = min (v.len, 0x00FF);
607 return *this << uint8 (len) << data (v.ptr, len);
608 }
609
610 packet &packet::operator <<(const data16 &v)
611 {
612 unsigned int len = min (v.len, 0xFFFF);
613 return *this << uint16 (len) << data (v.ptr, len);
614 }
615
616 packet &packet::operator <<(const char *v)
617 {
618 return *this << data (v, strlen (v ? v : 0));
619 }
620
621 void
622 packet::vprintf (const char *format, va_list ap)
623 {
624 int size = room ();
625
626 int len = vsnprintf ((char *)cur, size, format, ap);
627
628 if (len >= size)
629 return reset ();
630
631 cur += len;
632 }
633