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/cvs/deliantra/server/socket/lowlevel.C
Revision: 1.1
Committed: Sun Aug 13 17:16:06 2006 UTC (17 years, 9 months ago) by elmex
Content type: text/plain
Branch: MAIN
Log Message: 
Made server compile with C++.
Removed cfanim plugin and crossedit.
C++ here we come.

File Contents

# Content
1
2 /*
3 * static char *rcsid_sockets_c =
4 * "$Id$";
5 */
6
7 /*
8 CrossFire, A Multiplayer game for X-windows
9
10 Copyright (C) 1992 Frank Tore Johansen
11
12 This program is free software; you can redistribute it and/or modify
13 it under the terms of the GNU General Public License as published by
14 the Free Software Foundation; either version 2 of the License, or
15 (at your option) any later version.
16
17 This program is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU General Public License for more details.
21
22 You should have received a copy of the GNU General Public License
23 along with this program; if not, write to the Free Software
24 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25
26 The author can be reached via e-mail to mark@pyramid.com
27 */
28
29 /**
30 * \file
31 * Low-level socket-related functions.
32 *
33 * \date 2003-12-02
34 *
35 * Contains some base functions that both the client and server
36 * can use. As such, depending what we are being compiled for will
37 * determine what we can include. the client is designed have
38 * CFCLIENT defined as part of its compile flags.
39 */
40
41 using namespace std;
42
43 #include <global.h>
44 #include <newclient.h>
45 #include <sproto.h>
46
47 #ifdef __linux__
48 # include <sys/types.h>
49 # include <sys/socket.h>
50 # include <netinet/in.h>
51 # define TCP_HZ 1000 // sorry...
52 # include <netinet/tcp.h>
53 #endif
54
55 // use a really low timeout, as it doesn't cost any bandwidth, and you can
56 // easily die in 20 seconds...
57 #define SOCKET_TIMEOUT1 10
58 #define SOCKET_TIMEOUT2 20
59
60 void Socket_Flush (NewSocket *ns)
61 {
62 #ifdef __linux__
63 // check time of last ack, and, if too old, kill connection
64 struct tcp_info tcpi;
65 socklen_t len = sizeof (tcpi);
66
67 if (!getsockopt (ns->fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
68 {
69 unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;
70
71 if (tcpi.tcpi_unacked
72 && SOCKET_TIMEOUT1 * TCP_HZ < diff && diff < 0x80000000UL // ack delayed for 20s
73 && SOCKET_TIMEOUT2 * TCP_HZ < 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", ns->fd,
76 (unsigned)tcpi.tcpi_last_ack_recv, (unsigned)tcpi.tcpi_last_data_sent, (unsigned)tcpi.tcpi_unacked);
77 ns->status = Ns_Dead;
78 }
79 }
80
81 int val;
82 val = 0; setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
83 val = 1; setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
84 #endif
85 }
86
87 /***********************************************************************
88 *
89 * SockList functions/utilities
90 *
91 **********************************************************************/
92
93 void SockList_Init(SockList *sl)
94 {
95 sl->len=0;
96 sl->buf=NULL;
97 }
98
99 void SockList_AddChar(SockList *sl, char c)
100 {
101 sl->buf[sl->len]=c;
102 sl->len++;
103 }
104
105 void SockList_AddShort(SockList *sl, uint16 data)
106 {
107 sl->buf[sl->len++]= (data>>8)&0xff;
108 sl->buf[sl->len++] = data & 0xff;
109 }
110
111
112 void SockList_AddInt(SockList *sl, uint32 data)
113 {
114 sl->buf[sl->len++]= (data>>24)&0xff;
115 sl->buf[sl->len++]= (data>>16)&0xff;
116 sl->buf[sl->len++]= (data>>8)&0xff;
117 sl->buf[sl->len++] = data & 0xff;
118 }
119
120 void SockList_AddInt64(SockList *sl, uint64 data)
121 {
122 sl->buf[sl->len++]= ( char )( (data>>56)&0xff );
123 sl->buf[sl->len++]= ( char )( (data>>48)&0xff );
124 sl->buf[sl->len++]= ( char )( (data>>40)&0xff );
125 sl->buf[sl->len++]= ( char )( (data>>32)&0xff );
126
127 sl->buf[sl->len++]= ( char )( (data>>24)&0xff );
128 sl->buf[sl->len++]= ( char )( (data>>16)&0xff );
129 sl->buf[sl->len++]= ( char )( (data>>8)&0xff );
130 sl->buf[sl->len++] =( char )( data & 0xff );
131 }
132
133 /* Basically does the reverse of SockList_AddInt, but on
134 * strings instead. Same for the GetShort, but for 16 bits.
135 */
136 int GetInt_String(unsigned char *data)
137 {
138 return ((data[0]<<24) + (data[1]<<16) + (data[2]<<8) + data[3]);
139 }
140
141 short GetShort_String(unsigned char *data) {
142 return ((data[0]<<8)+data[1]);
143 }
144
145 /******************************************************************************
146 *
147 * Start of read routines.
148 *
149 ******************************************************************************/
150
151 /**
152 * This reads from fd and puts the data in sl. We return true if we think
153 * we have a full packet, 0 if we have a partial packet. The only processing
154 * we do is remove the intial size value. len (As passed) is the size of the
155 * buffer allocated in the socklist. We make the assumption the buffer is
156 * at least 2 bytes long.
157 */
158
159 int SockList_ReadPacket(int fd, SockList *sl, int len)
160 {
161 int stat,toread;
162
163 /* Sanity check - shouldn't happen */
164 if (sl->len < 0) {
165 abort();
166 }
167 /* We already have a partial packet */
168 if (sl->len<2) {
169 #ifdef WIN32 /* ***WIN32 SockList_ReadPacket: change read() to recv() */
170
171 stat=recv(fd, sl->buf + sl->len, 2-sl->len,0);
172
173 #else
174 do {
175 stat=read(fd, sl->buf + sl->len, 2-sl->len);
176 } while ((stat==-1) && (errno==EINTR));
177 #endif
178 if (stat<0) {
179 /* In non blocking mode, EAGAIN is set when there is no
180 * data available.
181 */
182 #ifdef WIN32 /* ***WIN32 SockList_ReadPacket: error handling for win32 */
183 if ((stat==-1) && WSAGetLastError() !=WSAEWOULDBLOCK) {
184 if(WSAGetLastError() == WSAECONNRESET)
185 LOG(llevDebug,"Connection closed by client\n");
186 else
187 {
188 LOG(llevDebug,"ReadPacket got error %d, returning 0\n",WSAGetLastError());
189 }
190 return -1; /* kick this user! */
191 }
192 #else
193 if (errno != EAGAIN && errno !=EWOULDBLOCK) {
194 LOG(llevDebug, "ReadPacket got error %s, returning 0\n", strerror_local(errno));
195 }
196 #endif
197 return 0; /*Error */
198 }
199 if (stat==0) return -1;
200 sl->len += stat;
201 #ifdef CS_LOGSTATS
202 cst_tot.ibytes += stat;
203 cst_lst.ibytes += stat;
204 #endif
205 if (stat<2) 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 LOG(llevError,"SockList_ReadPacket: Want to read more bytes than will fit in buffer (%d>=%d).\n",
213 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 #ifdef WIN32 /* ***win32 SockList_ReadPacket: change read() to recv() */
229 stat = recv(fd, sl->buf+ sl->len, toread, 0);
230 #else
231 do {
232 stat = read(fd, sl->buf+ sl->len, toread);
233 } while ((stat<0) && (errno==EINTR));
234 #endif
235 if (stat<0) {
236
237 #ifdef WIN32 /* ***win32 SockList_ReadPacket: change error handling for win32 */
238 if ((stat==-1) && WSAGetLastError() !=WSAEWOULDBLOCK) {
239 if(WSAGetLastError() == WSAECONNRESET)
240 LOG(llevDebug,"Connection closed by client\n");
241 else
242 {
243 LOG(llevDebug,"ReadPacket got error %d, returning 0\n",WSAGetLastError());
244 }
245 return -1; /* kick this user! */
246 }
247 #else
248 if (errno != EAGAIN && errno !=EWOULDBLOCK) {
249 LOG(llevDebug, "ReadPacket got error %s, returning 0\n", strerror_local(errno));
250 }
251 #endif
252 return 0; /*Error */
253 }
254 if (stat==0) return -1;
255 sl->len += stat;
256 #ifdef CS_LOGSTATS
257 cst_tot.ibytes += stat;
258 cst_lst.ibytes += stat;
259 #endif
260 toread -= stat;
261 if (toread==0) return 1;
262 if (toread < 0) {
263 LOG(llevError,"SockList_ReadPacket: Read more bytes than desired.\n");
264 return 1;
265 }
266 } while (toread>0);
267 return 0;
268 }
269
270 /*******************************************************************************
271 *
272 * Start of write related routines.
273 *
274 ******************************************************************************/
275
276 /**
277 * Adds data to a socket buffer for whatever reason.
278 *
279 * ns is the socket we are adding the data to, buf is the start of the
280 * data, and len is the number of bytes to add.
281 */
282
283 static void add_to_buffer(NewSocket *ns, char *buf, int len)
284 {
285 int avail, end;
286
287 if ((len+ns->outputbuffer.len)>SOCKETBUFSIZE) {
288 LOG(llevDebug,"Socket on fd %d has overrun internal buffer - marking as dead\n",
289 ns->fd);
290 ns->status = Ns_Dead;
291 return;
292 }
293
294 /* data + end is where we start putting the new data. The last byte
295 * currently in use is actually data + end -1
296 */
297
298 end=ns->outputbuffer.start + ns->outputbuffer.len;
299 /* The buffer is already in a wrapped state, so adjust end */
300 if (end>=SOCKETBUFSIZE) end-=SOCKETBUFSIZE;
301 avail=SOCKETBUFSIZE - end;
302
303 /* We can all fit it behind the current data without wrapping */
304 if (avail >=len ) {
305 memcpy(ns->outputbuffer.data + end, buf, len);
306 }
307 else {
308 memcpy(ns->outputbuffer.data + end, buf, avail);
309 memcpy(ns->outputbuffer.data, buf+avail, len-avail);
310 }
311 ns->outputbuffer.len += len;
312 #if 0
313 LOG(llevDebug,"Added %d to output buffer, total length now %d, start=%d\n", len,
314 ns->outputbuffer.len, ns->outputbuffer.start);
315 #endif
316 }
317
318 /**
319 * Writes data to socket.
320 *
321 * When the socket is clear to write, and we have backlogged data, this
322 * is called to write it out.
323 */
324 void write_socket_buffer(NewSocket *ns)
325 {
326 int amt, max;
327
328 if (ns->outputbuffer.len==0) {
329 LOG(llevDebug,"write_socket_buffer called when there is no data, fd=%d\n",
330 ns->fd);
331 return;
332 }
333
334 do {
335 max = SOCKETBUFSIZE - ns->outputbuffer.start;
336 if (ns->outputbuffer.len<max) max = ns->outputbuffer.len;
337
338 #ifdef WIN32 /* ***win32 write_socket_buffer: change write() to send() */
339 amt=send(ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max,0);
340 #else
341 do {
342 amt=write(ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max);
343 } while ((amt<0) && (errno==EINTR));
344 #endif
345
346 if (amt < 0) { /* We got an error */
347
348 #ifdef WIN32 /* ***win32 write_socket_buffer: change error handling */
349 if (amt == -1 && WSAGetLastError() !=WSAEWOULDBLOCK) {
350 LOG(llevError,"New socket write failed (wsb) (%d).\n", WSAGetLastError());
351 #else
352 if (errno !=EWOULDBLOCK) {
353 LOG(llevError,"New socket write failed (wsb) (%d: %s).\n",
354 errno, strerror_local(errno));
355 #endif
356 ns->status=Ns_Dead;
357 return;
358 }
359 else { /* EWOULDBLOCK */
360 /* can't write it, so store it away. */
361 ns->can_write=0;
362 return;
363 }
364 }
365 ns->outputbuffer.start += amt;
366 /* wrap back to start of buffer */
367 if (ns->outputbuffer.start==SOCKETBUFSIZE) ns->outputbuffer.start=0;
368 ns->outputbuffer.len -= amt;
369 #ifdef CS_LOGSTATS
370 cst_tot.obytes += amt;
371 cst_lst.obytes += amt;
372 #endif
373 } while (ns->outputbuffer.len>0);
374 }
375
376 /**
377 * This writes data to the socket. - It is very low level -
378 * all we try and do is write out the data to the socket
379 * provided (ns). buf is the data to write, len is the number
380 * of bytes to write. IT doesn't return anything - rather, it
381 * updates the ns structure if we get an error.
382 */
383 void Write_To_Socket(NewSocket *ns, char *buf, int len)
384 {
385 int amt=0;
386 char *pos=buf;
387
388 if (ns->status == Ns_Dead || !buf) {
389 LOG(llevDebug,"Write_To_Socket called with dead socket\n");
390 return;
391 }
392
393 #ifndef __GNU__ /* This caused problems on Hurd */
394 if (!ns->can_write) {
395 add_to_buffer(ns, buf, len);
396 return;
397 }
398 #endif
399 /* If we manage to write more than we wanted, take it as a bonus */
400 while (len>0) {
401
402 #ifdef WIN32 /* ***win32 Write_To_Socket: change write() to send() */
403 amt=send(ns->fd, pos, len,0);
404 #else
405 do {
406 amt=write(ns->fd, pos, len);
407 } while ((amt<0) && (errno==EINTR));
408 #endif
409
410 if (amt < 0) { /* We got an error */
411 #ifdef WIN32 /* ***win32 Write_To_Socket: change error handling */
412 if (amt == -1 && WSAGetLastError() !=WSAEWOULDBLOCK) {
413 LOG(llevError,"New socket write failed WTS (%d).\n",WSAGetLastError());
414 #else
415 if (errno !=EWOULDBLOCK) {
416 LOG(llevError,"New socket write failed WTS (%d: %s).\n", /* ---WIN32 */
417 errno, strerror_local(errno));
418 #endif
419 ns->status=Ns_Dead;
420 return;
421 }
422 else { /* EWOULDBLOCK */
423 /* can't write it, so store it away. */
424 add_to_buffer(ns, pos, len);
425 ns->can_write=0;
426 return;
427 }
428 }
429 /* amt gets set to 0 above in blocking code, so we do this as
430 * an else if to make sure we don't reprocess it.
431 */
432 else if (amt==0) {
433 LOG(llevError,"Write_To_Socket: No data written out.\n");
434 }
435 len -= amt;
436 pos += amt;
437 #ifdef CS_LOGSTATS
438 cst_tot.obytes += amt;
439 cst_lst.obytes += amt;
440 #endif
441 }
442 }
443
444
445 /**
446 * Takes a string of data, and writes it out to the socket. A very handy
447 * shortcut function.
448 */
449 void cs_write_string(NewSocket *ns, const char *buf, int len)
450 {
451 SockList sl;
452
453 sl.len = len;
454 sl.buf = (unsigned char*)buf;
455 Send_With_Handling(ns, &sl);
456 }
457
458
459 /**
460 * Calls Write_To_Socket to send data to the client.
461 *
462 * The only difference in this function is that we take a SockList
463 *, and we prepend the length information.
464 */
465 void Send_With_Handling(NewSocket *ns,SockList *msg)
466 {
467 unsigned char sbuf[4];
468
469 if (ns->status == Ns_Dead || !msg)
470 return;
471
472 if (msg->len >= MAXSOCKBUF) {
473 LOG(llevError,"Trying to send a buffer beyond properly size, len =%d\n",
474 msg->len);
475 /* Almost certainly we've overflowed a buffer, so quite now to make
476 * it easier to debug.
477 */
478 abort();
479 }
480 sbuf[0] = ((uint32)(msg->len) >> 8) & 0xFF;
481 sbuf[1] = ((uint32)(msg->len)) & 0xFF;
482 if (ns->status != Ns_Old)
483 Write_To_Socket(ns, (char *) sbuf, 2);
484 Write_To_Socket(ns, (char*)msg->buf, msg->len);
485 }
486
487 /**
488 * Takes a string of data, and writes it out to the socket. A very handy
489 * shortcut function.
490 */
491 void Write_String_To_Socket(NewSocket *ns, char *buf, int len)
492 {
493 SockList sl;
494
495 sl.len = len;
496 sl.buf = (unsigned char*) buf;
497 Send_With_Handling(ns, &sl);
498 }
499
500
501 /******************************************************************************
502 *
503 * statistics logging functions.
504 *
505 ******************************************************************************/
506
507 #ifdef CS_LOGSTATS
508 /* cst_tot is for the life of the server, cst_last is for the last series of
509 * stats
510 */
511 CS_Stats cst_tot, cst_lst;
512
513 /**
514 * Writes out the gathered stats. We clear cst_lst.
515 */
516 void write_cs_stats(void)
517 {
518 time_t now=time(NULL);
519
520 /* If no connections recently, don't both to log anything */
521 if (cst_lst.ibytes==0 && cst_lst.obytes==0) return;
522
523 /* CSSTAT is put in so scripts can easily find the line */
524 LOG(llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
525 ctime(&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
526 now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes,
527 cst_lst.max_conn, now - cst_lst.time_start);
528 cst_lst.ibytes=0;
529 cst_lst.obytes=0;
530 cst_lst.max_conn=socket_info.nconns;
531 cst_lst.time_start=now;
532 }
533 #endif