ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/deliantra/server/socket/lowlevel.C
Revision: 1.1
Committed: Sun Aug 13 17:16:06 2006 UTC (17 years, 10 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

# User Rev Content
1 elmex 1.1
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