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/cvs/deliantra/server/socket/lowlevel.C
Revision: 1.2
Committed: Fri Aug 18 02:06:58 2006 UTC (17 years, 9 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.1: +1 -14 lines
Log Message:
support health stats in an extensible way in map1

File Contents

# Content
1
2 /*
3 * static char *rcsid_sockets_c =
4 * "$Id: lowlevel.C,v 1.1 2006-08-13 17:16:06 elmex Exp $";
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_AddInt(SockList *sl, uint32 data)
100 {
101 sl->buf[sl->len++]= (data>>24)&0xff;
102 sl->buf[sl->len++]= (data>>16)&0xff;
103 sl->buf[sl->len++]= (data>>8)&0xff;
104 sl->buf[sl->len++] = data & 0xff;
105 }
106
107 void 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 GetInt_String(unsigned char *data)
124 {
125 return ((data[0]<<24) + (data[1]<<16) + (data[2]<<8) + data[3]);
126 }
127
128 short GetShort_String(unsigned char *data) {
129 return ((data[0]<<8)+data[1]);
130 }
131
132 /******************************************************************************
133 *
134 * Start of read routines.
135 *
136 ******************************************************************************/
137
138 /**
139 * This reads from fd and puts the data in sl. We return true if we think
140 * we have a full packet, 0 if we have a partial packet. The only processing
141 * we do is remove the intial size value. len (As passed) is the size of the
142 * buffer allocated in the socklist. We make the assumption the buffer is
143 * at least 2 bytes long.
144 */
145
146 int SockList_ReadPacket(int fd, SockList *sl, int len)
147 {
148 int stat,toread;
149
150 /* Sanity check - shouldn't happen */
151 if (sl->len < 0) {
152 abort();
153 }
154 /* We already have a partial packet */
155 if (sl->len<2) {
156 #ifdef WIN32 /* ***WIN32 SockList_ReadPacket: change read() to recv() */
157
158 stat=recv(fd, sl->buf + sl->len, 2-sl->len,0);
159
160 #else
161 do {
162 stat=read(fd, sl->buf + sl->len, 2-sl->len);
163 } while ((stat==-1) && (errno==EINTR));
164 #endif
165 if (stat<0) {
166 /* In non blocking mode, EAGAIN is set when there is no
167 * data available.
168 */
169 #ifdef WIN32 /* ***WIN32 SockList_ReadPacket: error handling for win32 */
170 if ((stat==-1) && WSAGetLastError() !=WSAEWOULDBLOCK) {
171 if(WSAGetLastError() == WSAECONNRESET)
172 LOG(llevDebug,"Connection closed by client\n");
173 else
174 {
175 LOG(llevDebug,"ReadPacket got error %d, returning 0\n",WSAGetLastError());
176 }
177 return -1; /* kick this user! */
178 }
179 #else
180 if (errno != EAGAIN && errno !=EWOULDBLOCK) {
181 LOG(llevDebug, "ReadPacket got error %s, returning 0\n", strerror_local(errno));
182 }
183 #endif
184 return 0; /*Error */
185 }
186 if (stat==0) return -1;
187 sl->len += stat;
188 #ifdef CS_LOGSTATS
189 cst_tot.ibytes += stat;
190 cst_lst.ibytes += stat;
191 #endif
192 if (stat<2) return 0; /* Still don't have a full packet */
193 }
194 /* Figure out how much more data we need to read. Add 2 from the
195 * end of this - size header information is not included.
196 */
197 toread = 2+(sl->buf[0] << 8) + sl->buf[1] - sl->len;
198 if ((toread + sl->len) >= len) {
199 LOG(llevError,"SockList_ReadPacket: Want to read more bytes than will fit in buffer (%d>=%d).\n",
200 toread + sl->len, len);
201 /* Quick hack in case for 'oldsocketmode' input. If we are
202 * closing the socket anyways, then reading this extra 100 bytes
203 * shouldn't hurt.
204 */
205 #ifdef WIN32 /* ***win32 SockList_ReadPacket: change read() to recv() */
206 recv(fd, sl->buf+2, 100, 0);
207 #else
208 read(fd, sl->buf+2, 100);
209 #endif /* end win32 */
210
211 /* return error so the socket is closed */
212 return -1;
213 }
214 do {
215 #ifdef WIN32 /* ***win32 SockList_ReadPacket: change read() to recv() */
216 stat = recv(fd, sl->buf+ sl->len, toread, 0);
217 #else
218 do {
219 stat = read(fd, sl->buf+ sl->len, toread);
220 } while ((stat<0) && (errno==EINTR));
221 #endif
222 if (stat<0) {
223
224 #ifdef WIN32 /* ***win32 SockList_ReadPacket: change error handling for win32 */
225 if ((stat==-1) && WSAGetLastError() !=WSAEWOULDBLOCK) {
226 if(WSAGetLastError() == WSAECONNRESET)
227 LOG(llevDebug,"Connection closed by client\n");
228 else
229 {
230 LOG(llevDebug,"ReadPacket got error %d, returning 0\n",WSAGetLastError());
231 }
232 return -1; /* kick this user! */
233 }
234 #else
235 if (errno != EAGAIN && errno !=EWOULDBLOCK) {
236 LOG(llevDebug, "ReadPacket got error %s, returning 0\n", strerror_local(errno));
237 }
238 #endif
239 return 0; /*Error */
240 }
241 if (stat==0) return -1;
242 sl->len += stat;
243 #ifdef CS_LOGSTATS
244 cst_tot.ibytes += stat;
245 cst_lst.ibytes += stat;
246 #endif
247 toread -= stat;
248 if (toread==0) return 1;
249 if (toread < 0) {
250 LOG(llevError,"SockList_ReadPacket: Read more bytes than desired.\n");
251 return 1;
252 }
253 } while (toread>0);
254 return 0;
255 }
256
257 /*******************************************************************************
258 *
259 * Start of write related routines.
260 *
261 ******************************************************************************/
262
263 /**
264 * Adds data to a socket buffer for whatever reason.
265 *
266 * ns is the socket we are adding the data to, buf is the start of the
267 * data, and len is the number of bytes to add.
268 */
269
270 static void add_to_buffer(NewSocket *ns, char *buf, int len)
271 {
272 int avail, end;
273
274 if ((len+ns->outputbuffer.len)>SOCKETBUFSIZE) {
275 LOG(llevDebug,"Socket on fd %d has overrun internal buffer - marking as dead\n",
276 ns->fd);
277 ns->status = Ns_Dead;
278 return;
279 }
280
281 /* data + end is where we start putting the new data. The last byte
282 * currently in use is actually data + end -1
283 */
284
285 end=ns->outputbuffer.start + ns->outputbuffer.len;
286 /* The buffer is already in a wrapped state, so adjust end */
287 if (end>=SOCKETBUFSIZE) end-=SOCKETBUFSIZE;
288 avail=SOCKETBUFSIZE - end;
289
290 /* We can all fit it behind the current data without wrapping */
291 if (avail >=len ) {
292 memcpy(ns->outputbuffer.data + end, buf, len);
293 }
294 else {
295 memcpy(ns->outputbuffer.data + end, buf, avail);
296 memcpy(ns->outputbuffer.data, buf+avail, len-avail);
297 }
298 ns->outputbuffer.len += len;
299 #if 0
300 LOG(llevDebug,"Added %d to output buffer, total length now %d, start=%d\n", len,
301 ns->outputbuffer.len, ns->outputbuffer.start);
302 #endif
303 }
304
305 /**
306 * Writes data to socket.
307 *
308 * When the socket is clear to write, and we have backlogged data, this
309 * is called to write it out.
310 */
311 void write_socket_buffer(NewSocket *ns)
312 {
313 int amt, max;
314
315 if (ns->outputbuffer.len==0) {
316 LOG(llevDebug,"write_socket_buffer called when there is no data, fd=%d\n",
317 ns->fd);
318 return;
319 }
320
321 do {
322 max = SOCKETBUFSIZE - ns->outputbuffer.start;
323 if (ns->outputbuffer.len<max) max = ns->outputbuffer.len;
324
325 #ifdef WIN32 /* ***win32 write_socket_buffer: change write() to send() */
326 amt=send(ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max,0);
327 #else
328 do {
329 amt=write(ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max);
330 } while ((amt<0) && (errno==EINTR));
331 #endif
332
333 if (amt < 0) { /* We got an error */
334
335 #ifdef WIN32 /* ***win32 write_socket_buffer: change error handling */
336 if (amt == -1 && WSAGetLastError() !=WSAEWOULDBLOCK) {
337 LOG(llevError,"New socket write failed (wsb) (%d).\n", WSAGetLastError());
338 #else
339 if (errno !=EWOULDBLOCK) {
340 LOG(llevError,"New socket write failed (wsb) (%d: %s).\n",
341 errno, strerror_local(errno));
342 #endif
343 ns->status=Ns_Dead;
344 return;
345 }
346 else { /* EWOULDBLOCK */
347 /* can't write it, so store it away. */
348 ns->can_write=0;
349 return;
350 }
351 }
352 ns->outputbuffer.start += amt;
353 /* wrap back to start of buffer */
354 if (ns->outputbuffer.start==SOCKETBUFSIZE) ns->outputbuffer.start=0;
355 ns->outputbuffer.len -= amt;
356 #ifdef CS_LOGSTATS
357 cst_tot.obytes += amt;
358 cst_lst.obytes += amt;
359 #endif
360 } while (ns->outputbuffer.len>0);
361 }
362
363 /**
364 * This writes data to the socket. - It is very low level -
365 * all we try and do is write out the data to the socket
366 * provided (ns). buf is the data to write, len is the number
367 * of bytes to write. IT doesn't return anything - rather, it
368 * updates the ns structure if we get an error.
369 */
370 void Write_To_Socket(NewSocket *ns, char *buf, int len)
371 {
372 int amt=0;
373 char *pos=buf;
374
375 if (ns->status == Ns_Dead || !buf) {
376 LOG(llevDebug,"Write_To_Socket called with dead socket\n");
377 return;
378 }
379
380 #ifndef __GNU__ /* This caused problems on Hurd */
381 if (!ns->can_write) {
382 add_to_buffer(ns, buf, len);
383 return;
384 }
385 #endif
386 /* If we manage to write more than we wanted, take it as a bonus */
387 while (len>0) {
388
389 #ifdef WIN32 /* ***win32 Write_To_Socket: change write() to send() */
390 amt=send(ns->fd, pos, len,0);
391 #else
392 do {
393 amt=write(ns->fd, pos, len);
394 } while ((amt<0) && (errno==EINTR));
395 #endif
396
397 if (amt < 0) { /* We got an error */
398 #ifdef WIN32 /* ***win32 Write_To_Socket: change error handling */
399 if (amt == -1 && WSAGetLastError() !=WSAEWOULDBLOCK) {
400 LOG(llevError,"New socket write failed WTS (%d).\n",WSAGetLastError());
401 #else
402 if (errno !=EWOULDBLOCK) {
403 LOG(llevError,"New socket write failed WTS (%d: %s).\n", /* ---WIN32 */
404 errno, strerror_local(errno));
405 #endif
406 ns->status=Ns_Dead;
407 return;
408 }
409 else { /* EWOULDBLOCK */
410 /* can't write it, so store it away. */
411 add_to_buffer(ns, pos, len);
412 ns->can_write=0;
413 return;
414 }
415 }
416 /* amt gets set to 0 above in blocking code, so we do this as
417 * an else if to make sure we don't reprocess it.
418 */
419 else if (amt==0) {
420 LOG(llevError,"Write_To_Socket: No data written out.\n");
421 }
422 len -= amt;
423 pos += amt;
424 #ifdef CS_LOGSTATS
425 cst_tot.obytes += amt;
426 cst_lst.obytes += amt;
427 #endif
428 }
429 }
430
431
432 /**
433 * Takes a string of data, and writes it out to the socket. A very handy
434 * shortcut function.
435 */
436 void cs_write_string(NewSocket *ns, const char *buf, int len)
437 {
438 SockList sl;
439
440 sl.len = len;
441 sl.buf = (unsigned char*)buf;
442 Send_With_Handling(ns, &sl);
443 }
444
445
446 /**
447 * Calls Write_To_Socket to send data to the client.
448 *
449 * The only difference in this function is that we take a SockList
450 *, and we prepend the length information.
451 */
452 void Send_With_Handling(NewSocket *ns,SockList *msg)
453 {
454 unsigned char sbuf[4];
455
456 if (ns->status == Ns_Dead || !msg)
457 return;
458
459 if (msg->len >= MAXSOCKBUF) {
460 LOG(llevError,"Trying to send a buffer beyond properly size, len =%d\n",
461 msg->len);
462 /* Almost certainly we've overflowed a buffer, so quite now to make
463 * it easier to debug.
464 */
465 abort();
466 }
467 sbuf[0] = ((uint32)(msg->len) >> 8) & 0xFF;
468 sbuf[1] = ((uint32)(msg->len)) & 0xFF;
469 if (ns->status != Ns_Old)
470 Write_To_Socket(ns, (char *) sbuf, 2);
471 Write_To_Socket(ns, (char*)msg->buf, msg->len);
472 }
473
474 /**
475 * Takes a string of data, and writes it out to the socket. A very handy
476 * shortcut function.
477 */
478 void Write_String_To_Socket(NewSocket *ns, char *buf, int len)
479 {
480 SockList sl;
481
482 sl.len = len;
483 sl.buf = (unsigned char*) buf;
484 Send_With_Handling(ns, &sl);
485 }
486
487
488 /******************************************************************************
489 *
490 * statistics logging functions.
491 *
492 ******************************************************************************/
493
494 #ifdef CS_LOGSTATS
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 write_cs_stats(void)
504 {
505 time_t now=time(NULL);
506
507 /* If no connections recently, don't both to log anything */
508 if (cst_lst.ibytes==0 && cst_lst.obytes==0) return;
509
510 /* CSSTAT is put in so scripts can easily find the line */
511 LOG(llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
512 ctime(&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
513 now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes,
514 cst_lst.max_conn, now - cst_lst.time_start);
515 cst_lst.ibytes=0;
516 cst_lst.obytes=0;
517 cst_lst.max_conn=socket_info.nconns;
518 cst_lst.time_start=now;
519 }
520 #endif