ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/deliantra/server/socket/lowlevel.C
Revision: 1.6
Committed: Thu Sep 14 22:34:06 2006 UTC (17 years, 8 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.5: +0 -6 lines
Log Message:
indent

File Contents

# 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 <newclient.h>
39 #include <sproto.h>
40
41 #ifdef __linux__
42 # include <sys/types.h>
43 # include <sys/socket.h>
44 # include <netinet/in.h>
45 # define TCP_HZ 1000 // sorry...
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
52 #define SOCKET_TIMEOUT2 20
53
54 void
55 Socket_Flush (NewSocket * ns)
56 {
57 #ifdef __linux__
58 // check time of last ack, and, if too old, kill connection
59 struct tcp_info tcpi;
60 socklen_t len = sizeof (tcpi);
61
62 if (!getsockopt (ns->fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
63 {
64 unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;
65
66 if (tcpi.tcpi_unacked && SOCKET_TIMEOUT1 * TCP_HZ < diff && diff < 0x80000000UL // ack delayed for 20s
67 && SOCKET_TIMEOUT2 * TCP_HZ < tcpi.tcpi_last_data_sent) // no data sent for 10s
68 {
69 LOG (llevDebug, "Connection on fd %d closed due to ack timeout (%u/%u/%u)\n", ns->fd,
70 (unsigned) tcpi.tcpi_last_ack_recv, (unsigned) tcpi.tcpi_last_data_sent, (unsigned) tcpi.tcpi_unacked);
71 ns->status = Ns_Dead;
72 }
73 }
74
75 int val;
76
77 val = 0;
78 setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
79 val = 1;
80 setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
81 #endif
82 }
83
84 /***********************************************************************
85 *
86 * SockList functions/utilities
87 *
88 **********************************************************************/
89
90 void
91 SockList_Init (SockList * sl)
92 {
93 sl->len = 0;
94 sl->buf = NULL;
95 }
96
97 void
98 SockList_AddInt (SockList * sl, uint32 data)
99 {
100 sl->buf[sl->len++] = (data >> 24) & 0xff;
101 sl->buf[sl->len++] = (data >> 16) & 0xff;
102 sl->buf[sl->len++] = (data >> 8) & 0xff;
103 sl->buf[sl->len++] = data & 0xff;
104 }
105
106 void
107 SockList_AddInt64 (SockList * sl, uint64 data)
108 {
109 sl->buf[sl->len++] = (char) ((data >> 56) & 0xff);
110 sl->buf[sl->len++] = (char) ((data >> 48) & 0xff);
111 sl->buf[sl->len++] = (char) ((data >> 40) & 0xff);
112 sl->buf[sl->len++] = (char) ((data >> 32) & 0xff);
113
114 sl->buf[sl->len++] = (char) ((data >> 24) & 0xff);
115 sl->buf[sl->len++] = (char) ((data >> 16) & 0xff);
116 sl->buf[sl->len++] = (char) ((data >> 8) & 0xff);
117 sl->buf[sl->len++] = (char) (data & 0xff);
118 }
119
120 /* Basically does the reverse of SockList_AddInt, but on
121 * strings instead. Same for the GetShort, but for 16 bits.
122 */
123 int
124 GetInt_String (unsigned char *data)
125 {
126 return ((data[0] << 24) + (data[1] << 16) + (data[2] << 8) + data[3]);
127 }
128
129 short
130 GetShort_String (unsigned char *data)
131 {
132 return ((data[0] << 8) + data[1]);
133 }
134
135 /******************************************************************************
136 *
137 * Start of read routines.
138 *
139 ******************************************************************************/
140
141 /**
142 * This reads from fd and puts the data in sl. We return true if we think
143 * we have a full packet, 0 if we have a partial packet. The only processing
144 * we do is remove the intial size value. len (As passed) is the size of the
145 * buffer allocated in the socklist. We make the assumption the buffer is
146 * at least 2 bytes long.
147 */
148
149 int
150 SockList_ReadPacket (int fd, SockList * sl, int len)
151 {
152 int stat, toread;
153
154 /* Sanity check - shouldn't happen */
155 if (sl->len < 0)
156 {
157 abort ();
158 }
159 /* We already have a partial packet */
160 if (sl->len < 2)
161 {
162 #ifdef WIN32 /* ***WIN32 SockList_ReadPacket: change read() to recv() */
163
164 stat = recv (fd, sl->buf + sl->len, 2 - sl->len, 0);
165
166 #else
167 do
168 {
169 stat = read (fd, sl->buf + sl->len, 2 - sl->len);
170 }
171 while ((stat == -1) && (errno == EINTR));
172 #endif
173 if (stat < 0)
174 {
175 /* In non blocking mode, EAGAIN is set when there is no
176 * data available.
177 */
178 #ifdef WIN32 /* ***WIN32 SockList_ReadPacket: error handling for win32 */
179 if ((stat == -1) && WSAGetLastError () != WSAEWOULDBLOCK)
180 {
181 if (WSAGetLastError () == WSAECONNRESET)
182 LOG (llevDebug, "Connection closed by client\n");
183 else
184 {
185 LOG (llevDebug, "ReadPacket got error %d, returning 0\n", WSAGetLastError ());
186 }
187 return -1; /* kick this user! */
188 }
189 #else
190 if (errno != EAGAIN && errno != EWOULDBLOCK)
191 {
192 LOG (llevDebug, "ReadPacket got error %s, returning 0\n", strerror (errno));
193 }
194 #endif
195 return 0; /*Error */
196 }
197 if (stat == 0)
198 return -1;
199 sl->len += stat;
200 #ifdef CS_LOGSTATS
201 cst_tot.ibytes += stat;
202 cst_lst.ibytes += stat;
203 #endif
204 if (stat < 2)
205 return 0; /* Still don't have a full packet */
206 }
207 /* Figure out how much more data we need to read. Add 2 from the
208 * end of this - size header information is not included.
209 */
210 toread = 2 + (sl->buf[0] << 8) + sl->buf[1] - sl->len;
211 if ((toread + sl->len) >= len)
212 {
213 LOG (llevError, "SockList_ReadPacket: Want to read more bytes than will fit in buffer (%d>=%d).\n", toread + sl->len, len);
214 /* Quick hack in case for 'oldsocketmode' input. If we are
215 * closing the socket anyways, then reading this extra 100 bytes
216 * shouldn't hurt.
217 */
218 #ifdef WIN32 /* ***win32 SockList_ReadPacket: change read() to recv() */
219 recv (fd, sl->buf + 2, 100, 0);
220 #else
221 read (fd, sl->buf + 2, 100);
222 #endif /* end win32 */
223
224 /* return error so the socket is closed */
225 return -1;
226 }
227 do
228 {
229 #ifdef WIN32 /* ***win32 SockList_ReadPacket: change read() to recv() */
230 stat = recv (fd, sl->buf + sl->len, toread, 0);
231 #else
232 do
233 {
234 stat = read (fd, sl->buf + sl->len, toread);
235 }
236 while ((stat < 0) && (errno == EINTR));
237 #endif
238 if (stat < 0)
239 {
240
241 #ifdef WIN32 /* ***win32 SockList_ReadPacket: change error handling for win32 */
242 if ((stat == -1) && WSAGetLastError () != WSAEWOULDBLOCK)
243 {
244 if (WSAGetLastError () == WSAECONNRESET)
245 LOG (llevDebug, "Connection closed by client\n");
246 else
247 {
248 LOG (llevDebug, "ReadPacket got error %d, returning 0\n", WSAGetLastError ());
249 }
250 return -1; /* kick this user! */
251 }
252 #else
253 if (errno != EAGAIN && errno != EWOULDBLOCK)
254 {
255 LOG (llevDebug, "ReadPacket got error %s, returning 0\n", strerror (errno));
256 }
257 #endif
258 return 0; /*Error */
259 }
260 if (stat == 0)
261 return -1;
262 sl->len += stat;
263 #ifdef CS_LOGSTATS
264 cst_tot.ibytes += stat;
265 cst_lst.ibytes += stat;
266 #endif
267 toread -= stat;
268 if (toread == 0)
269 return 1;
270 if (toread < 0)
271 {
272 LOG (llevError, "SockList_ReadPacket: Read more bytes than desired.\n");
273 return 1;
274 }
275 }
276 while (toread > 0);
277 return 0;
278 }
279
280 /*******************************************************************************
281 *
282 * Start of write related routines.
283 *
284 ******************************************************************************/
285
286 /**
287 * Adds data to a socket buffer for whatever reason.
288 *
289 * ns is the socket we are adding the data to, buf is the start of the
290 * data, and len is the number of bytes to add.
291 */
292
293 static void
294 add_to_buffer (NewSocket * ns, char *buf, int len)
295 {
296 int avail, end;
297
298 if ((len + ns->outputbuffer.len) > SOCKETBUFSIZE)
299 {
300 LOG (llevDebug, "Socket on fd %d has overrun internal buffer - marking as dead\n", ns->fd);
301 ns->status = Ns_Dead;
302 return;
303 }
304
305 /* data + end is where we start putting the new data. The last byte
306 * currently in use is actually data + end -1
307 */
308
309 end = ns->outputbuffer.start + ns->outputbuffer.len;
310 /* The buffer is already in a wrapped state, so adjust end */
311 if (end >= SOCKETBUFSIZE)
312 end -= SOCKETBUFSIZE;
313 avail = SOCKETBUFSIZE - end;
314
315 /* We can all fit it behind the current data without wrapping */
316 if (avail >= len)
317 {
318 memcpy (ns->outputbuffer.data + end, buf, len);
319 }
320 else
321 {
322 memcpy (ns->outputbuffer.data + end, buf, avail);
323 memcpy (ns->outputbuffer.data, buf + avail, len - avail);
324 }
325 ns->outputbuffer.len += len;
326 #if 0
327 LOG (llevDebug, "Added %d to output buffer, total length now %d, start=%d\n", len, ns->outputbuffer.len, ns->outputbuffer.start);
328 #endif
329 }
330
331 /**
332 * Writes data to socket.
333 *
334 * When the socket is clear to write, and we have backlogged data, this
335 * is called to write it out.
336 */
337 void
338 write_socket_buffer (NewSocket * ns)
339 {
340 int amt, max;
341
342 if (ns->outputbuffer.len == 0)
343 {
344 LOG (llevDebug, "write_socket_buffer called when there is no data, fd=%d\n", ns->fd);
345 return;
346 }
347
348 do
349 {
350 max = SOCKETBUFSIZE - ns->outputbuffer.start;
351 if (ns->outputbuffer.len < max)
352 max = ns->outputbuffer.len;
353
354 #ifdef WIN32 /* ***win32 write_socket_buffer: change write() to send() */
355 amt = send (ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max, 0);
356 #else
357 do
358 {
359 amt = write (ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max);
360 }
361 while ((amt < 0) && (errno == EINTR));
362 #endif
363
364 if (amt < 0)
365 { /* We got an error */
366
367 #ifdef WIN32 /* ***win32 write_socket_buffer: change error handling */
368 if (amt == -1 && WSAGetLastError () != WSAEWOULDBLOCK)
369 {
370 LOG (llevError, "New socket write failed (wsb) (%d).\n", WSAGetLastError ());
371 #else
372 if (errno != EWOULDBLOCK)
373 {
374 LOG (llevError, "New socket write failed (wsb) (%d: %s).\n", errno, strerror (errno));
375 #endif
376 ns->status = Ns_Dead;
377 return;
378 }
379 else
380 { /* EWOULDBLOCK */
381 /* can't write it, so store it away. */
382 ns->can_write = 0;
383 return;
384 }
385 }
386 ns->outputbuffer.start += amt;
387 /* wrap back to start of buffer */
388 if (ns->outputbuffer.start == SOCKETBUFSIZE)
389 ns->outputbuffer.start = 0;
390 ns->outputbuffer.len -= amt;
391 #ifdef CS_LOGSTATS
392 cst_tot.obytes += amt;
393 cst_lst.obytes += amt;
394 #endif
395 }
396 while (ns->outputbuffer.len > 0);
397 }
398
399 /**
400 * This writes data to the socket. - It is very low level -
401 * all we try and do is write out the data to the socket
402 * provided (ns). buf is the data to write, len is the number
403 * of bytes to write. IT doesn't return anything - rather, it
404 * updates the ns structure if we get an error.
405 */
406 void
407 Write_To_Socket (NewSocket * ns, char *buf, int len)
408 {
409 int amt = 0;
410 char *pos = buf;
411
412 if (ns->status == Ns_Dead || !buf)
413 {
414 LOG (llevDebug, "Write_To_Socket called with dead socket\n");
415 return;
416 }
417
418 #ifndef __GNU__ /* This caused problems on Hurd */
419 if (!ns->can_write)
420 {
421 add_to_buffer (ns, buf, len);
422 return;
423 }
424 #endif
425 /* If we manage to write more than we wanted, take it as a bonus */
426 while (len > 0)
427 {
428
429 #ifdef WIN32 /* ***win32 Write_To_Socket: change write() to send() */
430 amt = send (ns->fd, pos, len, 0);
431 #else
432 do
433 {
434 amt = write (ns->fd, pos, len);
435 }
436 while ((amt < 0) && (errno == EINTR));
437 #endif
438
439 if (amt < 0)
440 { /* We got an error */
441 #ifdef WIN32 /* ***win32 Write_To_Socket: change error handling */
442 if (amt == -1 && WSAGetLastError () != WSAEWOULDBLOCK)
443 {
444 LOG (llevError, "New socket write failed WTS (%d).\n", WSAGetLastError ());
445 #else
446 if (errno != EWOULDBLOCK)
447 {
448 LOG (llevError, "New socket write failed WTS (%d: %s).\n", /* ---WIN32 */
449 errno, strerror (errno));
450 #endif
451 ns->status = Ns_Dead;
452 return;
453 }
454 else
455 { /* EWOULDBLOCK */
456 /* can't write it, so store it away. */
457 add_to_buffer (ns, pos, len);
458 ns->can_write = 0;
459 return;
460 }
461 }
462 /* amt gets set to 0 above in blocking code, so we do this as
463 * an else if to make sure we don't reprocess it.
464 */
465 else if (amt == 0)
466 {
467 LOG (llevError, "Write_To_Socket: No data written out.\n");
468 }
469 len -= amt;
470 pos += amt;
471 #ifdef CS_LOGSTATS
472 cst_tot.obytes += amt;
473 cst_lst.obytes += amt;
474 #endif
475 }
476 }
477
478
479 /**
480 * Takes a string of data, and writes it out to the socket. A very handy
481 * shortcut function.
482 */
483 void
484 cs_write_string (NewSocket * ns, const char *buf, int len)
485 {
486 SockList sl;
487
488 sl.len = len;
489 sl.buf = (unsigned char *) buf;
490 Send_With_Handling (ns, &sl);
491 }
492
493
494 /**
495 * Calls Write_To_Socket to send data to the client.
496 *
497 * The only difference in this function is that we take a SockList
498 *, and we prepend the length information.
499 */
500 void
501 Send_With_Handling (NewSocket * ns, SockList * msg)
502 {
503 unsigned char sbuf[4];
504
505 if (ns->status == Ns_Dead || !msg)
506 return;
507
508 if (msg->len >= MAXSOCKBUF)
509 {
510 LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", msg->len);
511 /* Almost certainly we've overflowed a buffer, so quite now to make
512 * it easier to debug.
513 */
514 abort ();
515 }
516 sbuf[0] = ((uint32) (msg->len) >> 8) & 0xFF;
517 sbuf[1] = ((uint32) (msg->len)) & 0xFF;
518 if (ns->status != Ns_Old)
519 Write_To_Socket (ns, (char *) sbuf, 2);
520 Write_To_Socket (ns, (char *) msg->buf, msg->len);
521 }
522
523 /**
524 * Takes a string of data, and writes it out to the socket. A very handy
525 * shortcut function.
526 */
527 void
528 Write_String_To_Socket (NewSocket * ns, char *buf, int len)
529 {
530 SockList sl;
531
532 sl.len = len;
533 sl.buf = (unsigned char *) buf;
534 Send_With_Handling (ns, &sl);
535 }
536
537
538 /******************************************************************************
539 *
540 * statistics logging functions.
541 *
542 ******************************************************************************/
543
544 #ifdef CS_LOGSTATS
545
546 /* cst_tot is for the life of the server, cst_last is for the last series of
547 * stats
548 */
549 CS_Stats cst_tot, cst_lst;
550
551 /**
552 * Writes out the gathered stats. We clear cst_lst.
553 */
554 void
555 write_cs_stats (void)
556 {
557 time_t now = time (NULL);
558
559 /* If no connections recently, don't both to log anything */
560 if (cst_lst.ibytes == 0 && cst_lst.obytes == 0)
561 return;
562
563 /* CSSTAT is put in so scripts can easily find the line */
564 LOG (llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
565 ctime (&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
566 now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes, cst_lst.max_conn, now - cst_lst.time_start);
567 cst_lst.ibytes = 0;
568 cst_lst.obytes = 0;
569 cst_lst.max_conn = socket_info.nconns;
570 cst_lst.time_start = now;
571 }
572 #endif