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/cvs/deliantra/server/socket/lowlevel.C
Revision: 1.9
Committed: Wed Dec 13 18:08:02 2006 UTC (17 years, 5 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.8: +16 -27 lines
Log Message:
started simplifying network code

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; setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
78 val = 1; setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
79 #endif
80 }
81
82 /***********************************************************************
83 *
84 * SockList functions/utilities
85 *
86 **********************************************************************/
87
88 SockList &SockList::operator <<(const data8 &v)
89 {
90 *this << uint8 (v.len);
91
92 memcpy (buf + len, v.data, v.len);
93 len += v.len;
94
95 return *this;
96 }
97
98 SockList &SockList::operator <<(const data16 &v)
99 {
100 *this << uint16 (v.len);
101
102 memcpy (buf + len, v.data, v.len);
103 len += v.len;
104
105 return *this;
106 }
107
108 /* Basically does the reverse of SockList_AddInt, but on
109 * strings instead. Same for the GetShort, but for 16 bits.
110 */
111 int
112 GetInt_String (unsigned char *data)
113 {
114 return ((data[0] << 24) + (data[1] << 16) + (data[2] << 8) + data[3]);
115 }
116
117 short
118 GetShort_String (unsigned char *data)
119 {
120 return ((data[0] << 8) + data[1]);
121 }
122
123 /******************************************************************************
124 *
125 * Start of read routines.
126 *
127 ******************************************************************************/
128
129 /**
130 * This reads from fd and puts the data in sl. We return true if we think
131 * we have a full packet, 0 if we have a partial packet. The only processing
132 * we do is remove the intial size value. len (As passed) is the size of the
133 * buffer allocated in the socklist. We make the assumption the buffer is
134 * at least 2 bytes long.
135 */
136
137 int
138 SockList_ReadPacket (int fd, SockList * sl, int len)
139 {
140 int stat, toread;
141
142 /* Sanity check - shouldn't happen */
143 if (sl->len < 0)
144 {
145 abort ();
146 }
147 /* We already have a partial packet */
148 if (sl->len < 2)
149 {
150 do
151 {
152 stat = read (fd, sl->buf + sl->len, 2 - sl->len);
153 }
154 while ((stat == -1) && (errno == EINTR));
155
156 if (stat < 0)
157 {
158 /* In non blocking mode, EAGAIN is set when there is no
159 * data available.
160 */
161 if (errno != EAGAIN && errno != EWOULDBLOCK)
162 {
163 LOG (llevDebug, "ReadPacket got error %s, returning 0\n", strerror (errno));
164 }
165 return 0; /*Error */
166 }
167 if (stat == 0)
168 return -1;
169 sl->len += stat;
170 #ifdef CS_LOGSTATS
171 cst_tot.ibytes += stat;
172 cst_lst.ibytes += stat;
173 #endif
174 if (stat < 2)
175 return 0; /* Still don't have a full packet */
176 }
177 /* Figure out how much more data we need to read. Add 2 from the
178 * end of this - size header information is not included.
179 */
180 toread = 2 + (sl->buf[0] << 8) + sl->buf[1] - sl->len;
181 if ((toread + sl->len) >= len)
182 {
183 LOG (llevError, "SockList_ReadPacket: Want to read more bytes than will fit in buffer (%d>=%d).\n", toread + sl->len, len);
184 /* Quick hack in case for 'oldsocketmode' input. If we are
185 * closing the socket anyways, then reading this extra 100 bytes
186 * shouldn't hurt.
187 */
188 read (fd, sl->buf + 2, 100);
189
190 /* return error so the socket is closed */
191 return -1;
192 }
193 do
194 {
195 do
196 {
197 stat = read (fd, sl->buf + sl->len, toread);
198 }
199 while ((stat < 0) && (errno == EINTR));
200 if (stat < 0)
201 {
202
203 if (errno != EAGAIN && errno != EWOULDBLOCK)
204 {
205 LOG (llevDebug, "ReadPacket got error %s, returning 0\n", strerror (errno));
206 }
207 return 0; /*Error */
208 }
209 if (stat == 0)
210 return -1;
211 sl->len += stat;
212 #ifdef CS_LOGSTATS
213 cst_tot.ibytes += stat;
214 cst_lst.ibytes += stat;
215 #endif
216 toread -= stat;
217 if (toread == 0)
218 return 1;
219 if (toread < 0)
220 {
221 LOG (llevError, "SockList_ReadPacket: Read more bytes than desired.\n");
222 return 1;
223 }
224 }
225 while (toread > 0);
226 return 0;
227 }
228
229 /*******************************************************************************
230 *
231 * Start of write related routines.
232 *
233 ******************************************************************************/
234
235 /**
236 * Adds data to a socket buffer for whatever reason.
237 *
238 * ns is the socket we are adding the data to, buf is the start of the
239 * data, and len is the number of bytes to add.
240 */
241
242 static void
243 add_to_buffer (NewSocket * ns, char *buf, int len)
244 {
245 int avail, end;
246
247 if ((len + ns->outputbuffer.len) > SOCKETBUFSIZE)
248 {
249 LOG (llevDebug, "Socket on fd %d has overrun internal buffer - marking as dead\n", ns->fd);
250 ns->status = Ns_Dead;
251 return;
252 }
253
254 /* data + end is where we start putting the new data. The last byte
255 * currently in use is actually data + end -1
256 */
257
258 end = ns->outputbuffer.start + ns->outputbuffer.len;
259 /* The buffer is already in a wrapped state, so adjust end */
260 if (end >= SOCKETBUFSIZE)
261 end -= SOCKETBUFSIZE;
262
263 avail = SOCKETBUFSIZE - end;
264
265 /* We can all fit it behind the current data without wrapping */
266 if (avail >= len)
267 memcpy (ns->outputbuffer.data + end, buf, len);
268 else
269 {
270 memcpy (ns->outputbuffer.data + end, buf, avail);
271 memcpy (ns->outputbuffer.data, buf + avail, len - avail);
272 }
273
274 ns->outputbuffer.len += len;
275 #if 0
276 LOG (llevDebug, "Added %d to output buffer, total length now %d, start=%d\n", len, ns->outputbuffer.len, ns->outputbuffer.start);
277 #endif
278 }
279
280 /**
281 * Writes data to socket.
282 *
283 * When the socket is clear to write, and we have backlogged data, this
284 * is called to write it out.
285 */
286 void
287 write_socket_buffer (NewSocket * ns)
288 {
289 int amt, max;
290
291 if (ns->outputbuffer.len == 0)
292 {
293 LOG (llevDebug, "write_socket_buffer called when there is no data, fd=%d\n", ns->fd);
294 return;
295 }
296
297 do
298 {
299 max = SOCKETBUFSIZE - ns->outputbuffer.start;
300 if (ns->outputbuffer.len < max)
301 max = ns->outputbuffer.len;
302
303 do
304 {
305 amt = write (ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max);
306 }
307 while ((amt < 0) && (errno == EINTR));
308
309 if (amt < 0)
310 { /* We got an error */
311
312 if (errno != EWOULDBLOCK)
313 {
314 LOG (llevError, "New socket write failed (wsb) (%d: %s).\n", errno, strerror (errno));
315 ns->status = Ns_Dead;
316 return;
317 }
318 else
319 { /* EWOULDBLOCK */
320 /* can't write it, so store it away. */
321 ns->can_write = 0;
322 return;
323 }
324 }
325 ns->outputbuffer.start += amt;
326 /* wrap back to start of buffer */
327 if (ns->outputbuffer.start == SOCKETBUFSIZE)
328 ns->outputbuffer.start = 0;
329 ns->outputbuffer.len -= amt;
330 #ifdef CS_LOGSTATS
331 cst_tot.obytes += amt;
332 cst_lst.obytes += amt;
333 #endif
334 }
335 while (ns->outputbuffer.len > 0);
336 }
337
338 /**
339 * This writes data to the socket. - It is very low level -
340 * all we try and do is write out the data to the socket
341 * provided (ns). buf is the data to write, len is the number
342 * of bytes to write. IT doesn't return anything - rather, it
343 * updates the ns structure if we get an error.
344 */
345 void
346 Write_To_Socket (NewSocket * ns, char *buf, int len)
347 {
348 int amt = 0;
349 char *pos = buf;
350
351 if (ns->status == Ns_Dead || !buf)
352 {
353 LOG (llevDebug, "Write_To_Socket called with dead socket\n");
354 return;
355 }
356
357 #ifndef __GNU__ /* This caused problems on Hurd */
358 if (!ns->can_write)
359 {
360 add_to_buffer (ns, buf, len);
361 return;
362 }
363 #endif
364 /* If we manage to write more than we wanted, take it as a bonus */
365 while (len > 0)
366 {
367
368 do
369 {
370 amt = write (ns->fd, pos, len);
371 }
372 while ((amt < 0) && (errno == EINTR));
373
374 if (amt < 0)
375 { /* We got an error */
376 if (errno != EWOULDBLOCK)
377 {
378 LOG (llevError, "New socket write failed WTS (%d: %s).\n", /* ---WIN32 */
379 errno, strerror (errno));
380 ns->status = Ns_Dead;
381 return;
382 }
383 else
384 { /* EWOULDBLOCK */
385 /* can't write it, so store it away. */
386 add_to_buffer (ns, pos, len);
387 ns->can_write = 0;
388 return;
389 }
390 }
391 /* amt gets set to 0 above in blocking code, so we do this as
392 * an else if to make sure we don't reprocess it.
393 */
394 else if (amt == 0)
395 {
396 LOG (llevError, "Write_To_Socket: No data written out.\n");
397 }
398 len -= amt;
399 pos += amt;
400 #ifdef CS_LOGSTATS
401 cst_tot.obytes += amt;
402 cst_lst.obytes += amt;
403 #endif
404 }
405 }
406
407
408 /**
409 * Takes a string of data, and writes it out to the socket. A very handy
410 * shortcut function.
411 */
412 void
413 cs_write_string (NewSocket * ns, const char *buf, int len)
414 {
415 SockList sl;
416
417 sl.len = len;
418 sl.buf = (unsigned char *) buf;
419 Send_With_Handling (ns, &sl);
420 }
421
422
423 /**
424 * Calls Write_To_Socket to send data to the client.
425 *
426 * The only difference in this function is that we take a SockList
427 *, and we prepend the length information.
428 */
429 void
430 Send_With_Handling (NewSocket * ns, SockList * msg)
431 {
432 unsigned char sbuf[4];
433
434 if (ns->status == Ns_Dead || !msg)
435 return;
436
437 if (msg->len >= MAXSOCKBUF)
438 {
439 LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", msg->len);
440 /* Almost certainly we've overflowed a buffer, so quite now to make
441 * it easier to debug.
442 */
443 abort ();
444 }
445 sbuf[0] = ((uint32) (msg->len) >> 8) & 0xFF;
446 sbuf[1] = ((uint32) (msg->len)) & 0xFF;
447 if (ns->status != Ns_Old)
448 Write_To_Socket (ns, (char *) sbuf, 2);
449 Write_To_Socket (ns, (char *) msg->buf, msg->len);
450 }
451
452 /**
453 * Takes a string of data, and writes it out to the socket. A very handy
454 * shortcut function.
455 */
456 void
457 Write_String_To_Socket (NewSocket * ns, char *buf, int len)
458 {
459 SockList sl;
460
461 sl.len = len;
462 sl.buf = (unsigned char *) buf;
463 Send_With_Handling (ns, &sl);
464 }
465
466
467 /******************************************************************************
468 *
469 * statistics logging functions.
470 *
471 ******************************************************************************/
472
473 #ifdef CS_LOGSTATS
474
475 /* cst_tot is for the life of the server, cst_last is for the last series of
476 * stats
477 */
478 CS_Stats cst_tot, cst_lst;
479
480 /**
481 * Writes out the gathered stats. We clear cst_lst.
482 */
483 void
484 write_cs_stats (void)
485 {
486 time_t now = time (NULL);
487
488 /* If no connections recently, don't both to log anything */
489 if (cst_lst.ibytes == 0 && cst_lst.obytes == 0)
490 return;
491
492 /* CSSTAT is put in so scripts can easily find the line */
493 LOG (llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
494 ctime (&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
495 now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes, cst_lst.max_conn, now - cst_lst.time_start);
496 cst_lst.ibytes = 0;
497 cst_lst.obytes = 0;
498 cst_lst.max_conn = socket_info.nconns;
499 cst_lst.time_start = now;
500 }
501 #endif
502