ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/deliantra/server/socket/lowlevel.C
Revision: 1.11
Committed: Wed Dec 13 21:27:09 2006 UTC (17 years, 5 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.10: +30 -22 lines
Log Message:
continued simplifying network code, partially removed support for sc protocol 1026

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 #include <cstdarg>
41
42 #ifdef __linux__
43 # include <sys/types.h>
44 # include <sys/socket.h>
45 # include <netinet/in.h>
46 # define TCP_HZ 1000 // sorry...
47 # include <netinet/tcp.h>
48 #endif
49
50 // use a really low timeout, as it doesn't cost any bandwidth, and you can
51 // easily die in 20 seconds...
52 #define SOCKET_TIMEOUT1 10
53 #define SOCKET_TIMEOUT2 20
54
55 void
56 Socket_Flush (NewSocket * ns)
57 {
58 #ifdef __linux__
59 // check time of last ack, and, if too old, kill connection
60 struct tcp_info tcpi;
61 socklen_t len = sizeof (tcpi);
62
63 if (!getsockopt (ns->fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
64 {
65 unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;
66
67 if (tcpi.tcpi_unacked && SOCKET_TIMEOUT1 * TCP_HZ < diff && diff < 0x80000000UL // ack delayed for 20s
68 && SOCKET_TIMEOUT2 * TCP_HZ < tcpi.tcpi_last_data_sent) // no data sent for 10s
69 {
70 LOG (llevDebug, "Connection on fd %d closed due to ack timeout (%u/%u/%u)\n", ns->fd,
71 (unsigned) tcpi.tcpi_last_ack_recv, (unsigned) tcpi.tcpi_last_data_sent, (unsigned) tcpi.tcpi_unacked);
72 ns->status = Ns_Dead;
73 }
74 }
75
76 int val;
77
78 val = 0; setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
79 val = 1; setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
80 #endif
81 }
82
83 /***********************************************************************
84 *
85 * SockList functions/utilities
86 *
87 **********************************************************************/
88
89 SockList &SockList::operator <<(const data &v)
90 {
91 if (v.len)
92 {
93 memcpy (buf + len, v.ptr, v.len);
94 len += v.len;
95 }
96
97 return *this;
98 }
99
100 SockList &SockList::operator <<(const data8 &v)
101 {
102 unsigned int len = min (v.len, 0x00FF);
103 return *this << uint8 (len) << data (v.ptr, len);
104 }
105
106 SockList &SockList::operator <<(const data16 &v)
107 {
108 unsigned int len = min (v.len, 0xFFFF);
109 return *this << uint16 (len) << data (v.ptr, len);
110 }
111
112 SockList &SockList::operator <<(const char *v)
113 {
114 return *this << data (v, strlen (v ? v : 0));
115 }
116
117 void
118 SockList::printf (const char *format, ...)
119 {
120 va_list ap;
121 va_start (ap, format);
122
123 len += vsprintf ((char *)buf + len, format, ap);
124
125 va_end (ap);
126 }
127
128 /* Basically does the reverse of SockList_AddInt, but on
129 * strings instead. Same for the GetShort, but for 16 bits.
130 */
131 int
132 GetInt_String (unsigned char *data)
133 {
134 return ((data[0] << 24) + (data[1] << 16) + (data[2] << 8) + data[3]);
135 }
136
137 short
138 GetShort_String (unsigned char *data)
139 {
140 return ((data[0] << 8) + data[1]);
141 }
142
143 /******************************************************************************
144 *
145 * Start of read routines.
146 *
147 ******************************************************************************/
148
149 /**
150 * This reads from fd and puts the data in sl. We return true if we think
151 * we have a full packet, 0 if we have a partial packet. The only processing
152 * we do is remove the intial size value. len (As passed) is the size of the
153 * buffer allocated in the socklist. We make the assumption the buffer is
154 * at least 2 bytes long.
155 */
156
157 int
158 SockList_ReadPacket (int fd, SockList *sl, int len)
159 {
160 int stat, toread;
161
162 /* Sanity check - shouldn't happen */
163 if (sl->len < 0)
164 {
165 abort ();
166 }
167 /* We already have a partial packet */
168 if (sl->len < 2)
169 {
170 do
171 {
172 stat = read (fd, sl->buf + sl->len, 2 - sl->len);
173 }
174 while ((stat == -1) && (errno == EINTR));
175
176 if (stat < 0)
177 {
178 /* In non blocking mode, EAGAIN is set when there is no
179 * data available.
180 */
181 if (errno != EAGAIN && errno != EWOULDBLOCK)
182 {
183 LOG (llevDebug, "ReadPacket got error %s, returning 0\n", strerror (errno));
184 }
185 return 0; /*Error */
186 }
187 if (stat == 0)
188 return -1;
189 sl->len += stat;
190 #ifdef CS_LOGSTATS
191 cst_tot.ibytes += stat;
192 cst_lst.ibytes += stat;
193 #endif
194 if (stat < 2)
195 return 0; /* Still don't have a full packet */
196 }
197 /* Figure out how much more data we need to read. Add 2 from the
198 * end of this - size header information is not included.
199 */
200 toread = 2 + (sl->buf[0] << 8) + sl->buf[1] - sl->len;
201 if ((toread + sl->len) >= len)
202 {
203 LOG (llevError, "SockList_ReadPacket: Want to read more bytes than will fit in buffer (%d>=%d).\n", toread + sl->len, len);
204 /* Quick hack in case for 'oldsocketmode' input. If we are
205 * closing the socket anyways, then reading this extra 100 bytes
206 * shouldn't hurt.
207 */
208 read (fd, sl->buf + 2, 100);
209
210 /* return error so the socket is closed */
211 return -1;
212 }
213 do
214 {
215 do
216 {
217 stat = read (fd, sl->buf + sl->len, toread);
218 }
219 while ((stat < 0) && (errno == EINTR));
220 if (stat < 0)
221 {
222
223 if (errno != EAGAIN && errno != EWOULDBLOCK)
224 {
225 LOG (llevDebug, "ReadPacket got error %s, returning 0\n", strerror (errno));
226 }
227 return 0; /*Error */
228 }
229 if (stat == 0)
230 return -1;
231 sl->len += stat;
232 #ifdef CS_LOGSTATS
233 cst_tot.ibytes += stat;
234 cst_lst.ibytes += stat;
235 #endif
236 toread -= stat;
237 if (toread == 0)
238 return 1;
239 if (toread < 0)
240 {
241 LOG (llevError, "SockList_ReadPacket: Read more bytes than desired.\n");
242 return 1;
243 }
244 }
245 while (toread > 0);
246 return 0;
247 }
248
249 /*******************************************************************************
250 *
251 * Start of write related routines.
252 *
253 ******************************************************************************/
254
255 /**
256 * Adds data to a socket buffer for whatever reason.
257 *
258 * ns is the socket we are adding the data to, buf is the start of the
259 * data, and len is the number of bytes to add.
260 */
261
262 static void
263 add_to_buffer (NewSocket * ns, char *buf, int len)
264 {
265 int avail, end;
266
267 if ((len + ns->outputbuffer.len) > SOCKETBUFSIZE)
268 {
269 LOG (llevDebug, "Socket on fd %d has overrun internal buffer - marking as dead\n", ns->fd);
270 ns->status = Ns_Dead;
271 return;
272 }
273
274 /* data + end is where we start putting the new data. The last byte
275 * currently in use is actually data + end -1
276 */
277
278 end = ns->outputbuffer.start + ns->outputbuffer.len;
279 /* The buffer is already in a wrapped state, so adjust end */
280 if (end >= SOCKETBUFSIZE)
281 end -= SOCKETBUFSIZE;
282
283 avail = SOCKETBUFSIZE - end;
284
285 /* We can all fit it behind the current data without wrapping */
286 if (avail >= len)
287 memcpy (ns->outputbuffer.data + end, buf, len);
288 else
289 {
290 memcpy (ns->outputbuffer.data + end, buf, avail);
291 memcpy (ns->outputbuffer.data, buf + avail, len - avail);
292 }
293
294 ns->outputbuffer.len += len;
295 #if 0
296 LOG (llevDebug, "Added %d to output buffer, total length now %d, start=%d\n", len, ns->outputbuffer.len, ns->outputbuffer.start);
297 #endif
298 }
299
300 /**
301 * Writes data to socket.
302 *
303 * When the socket is clear to write, and we have backlogged data, this
304 * is called to write it out.
305 */
306 void
307 write_socket_buffer (NewSocket * ns)
308 {
309 int amt, max;
310
311 if (ns->outputbuffer.len == 0)
312 {
313 LOG (llevDebug, "write_socket_buffer called when there is no data, fd=%d\n", ns->fd);
314 return;
315 }
316
317 do
318 {
319 max = SOCKETBUFSIZE - ns->outputbuffer.start;
320 if (ns->outputbuffer.len < max)
321 max = ns->outputbuffer.len;
322
323 do
324 {
325 amt = write (ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max);
326 }
327 while ((amt < 0) && (errno == EINTR));
328
329 if (amt < 0)
330 { /* We got an error */
331
332 if (errno != EWOULDBLOCK)
333 {
334 LOG (llevError, "New socket write failed (wsb) (%d: %s).\n", errno, strerror (errno));
335 ns->status = Ns_Dead;
336 return;
337 }
338 else
339 { /* EWOULDBLOCK */
340 /* can't write it, so store it away. */
341 ns->can_write = 0;
342 return;
343 }
344 }
345 ns->outputbuffer.start += amt;
346 /* wrap back to start of buffer */
347 if (ns->outputbuffer.start == SOCKETBUFSIZE)
348 ns->outputbuffer.start = 0;
349 ns->outputbuffer.len -= amt;
350 #ifdef CS_LOGSTATS
351 cst_tot.obytes += amt;
352 cst_lst.obytes += amt;
353 #endif
354 }
355 while (ns->outputbuffer.len > 0);
356 }
357
358 /**
359 * This writes data to the socket. - It is very low level -
360 * all we try and do is write out the data to the socket
361 * provided (ns). buf is the data to write, len is the number
362 * of bytes to write. IT doesn't return anything - rather, it
363 * updates the ns structure if we get an error.
364 */
365 void
366 Write_To_Socket (NewSocket * ns, char *buf, int len)
367 {
368 int amt = 0;
369 char *pos = buf;
370
371 if (ns->status == Ns_Dead || !buf)
372 {
373 LOG (llevDebug, "Write_To_Socket called with dead socket\n");
374 return;
375 }
376
377 #ifndef __GNU__ /* This caused problems on Hurd */
378 if (!ns->can_write)
379 {
380 add_to_buffer (ns, buf, len);
381 return;
382 }
383 #endif
384 /* If we manage to write more than we wanted, take it as a bonus */
385 while (len > 0)
386 {
387
388 do
389 {
390 amt = write (ns->fd, pos, len);
391 }
392 while ((amt < 0) && (errno == EINTR));
393
394 if (amt < 0)
395 { /* We got an error */
396 if (errno != EWOULDBLOCK)
397 {
398 LOG (llevError, "New socket write failed WTS (%d: %s).\n", /* ---WIN32 */
399 errno, strerror (errno));
400 ns->status = Ns_Dead;
401 return;
402 }
403 else
404 { /* EWOULDBLOCK */
405 /* can't write it, so store it away. */
406 add_to_buffer (ns, pos, len);
407 ns->can_write = 0;
408 return;
409 }
410 }
411 /* amt gets set to 0 above in blocking code, so we do this as
412 * an else if to make sure we don't reprocess it.
413 */
414 else if (amt == 0)
415 {
416 LOG (llevError, "Write_To_Socket: No data written out.\n");
417 }
418 len -= amt;
419 pos += amt;
420 #ifdef CS_LOGSTATS
421 cst_tot.obytes += amt;
422 cst_lst.obytes += amt;
423 #endif
424 }
425 }
426
427
428 /**
429 * Takes a string of data, and writes it out to the socket. A very handy
430 * shortcut function.
431 */
432 void
433 cs_write_string (NewSocket *ns, const char *buf, int len)
434 {
435 SockList sl;
436
437 sl.len = len;
438 sl.buf = (unsigned char *) buf;
439 Send_With_Handling (ns, &sl);
440 }
441
442
443 /**
444 * Calls Write_To_Socket to send data to the client.
445 *
446 * The only difference in this function is that we take a SockList
447 *, and we prepend the length information.
448 */
449 void
450 Send_With_Handling (NewSocket *ns, SockList *msg)
451 {
452 unsigned char sbuf[4];
453
454 if (ns->status == Ns_Dead || !msg)
455 return;
456
457 if (msg->len >= MAXSOCKBUF)
458 {
459 LOG (llevError, "Trying to send a buffer beyond properly size, len =%d\n", msg->len);
460 /* Almost certainly we've overflowed a buffer, so quite now to make
461 * it easier to debug.
462 */
463 abort ();
464 }
465 sbuf[0] = ((uint32) (msg->len) >> 8) & 0xFF;
466 sbuf[1] = ((uint32) (msg->len)) & 0xFF;
467 if (ns->status != Ns_Old)
468 Write_To_Socket (ns, (char *) sbuf, 2);
469 Write_To_Socket (ns, (char *) msg->buf, msg->len);
470 }
471
472 /**
473 * Takes a string of data, and writes it out to the socket. A very handy
474 * shortcut function.
475 */
476 void
477 Write_String_To_Socket (NewSocket *ns, char *buf, int len)
478 {
479 SockList sl;
480
481 sl.len = len;
482 sl.buf = (unsigned char *) buf;
483 Send_With_Handling (ns, &sl);
484 }
485
486
487 /******************************************************************************
488 *
489 * statistics logging functions.
490 *
491 ******************************************************************************/
492
493 #ifdef CS_LOGSTATS
494
495 /* cst_tot is for the life of the server, cst_last is for the last series of
496 * stats
497 */
498 CS_Stats cst_tot, cst_lst;
499
500 /**
501 * Writes out the gathered stats. We clear cst_lst.
502 */
503 void
504 write_cs_stats (void)
505 {
506 time_t now = time (NULL);
507
508 /* If no connections recently, don't both to log anything */
509 if (cst_lst.ibytes == 0 && cst_lst.obytes == 0)
510 return;
511
512 /* CSSTAT is put in so scripts can easily find the line */
513 LOG (llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
514 ctime (&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
515 now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes, cst_lst.max_conn, now - cst_lst.time_start);
516 cst_lst.ibytes = 0;
517 cst_lst.obytes = 0;
518 cst_lst.max_conn = socket_info.nconns;
519 cst_lst.time_start = now;
520 }
521 #endif
522