summaryrefslogtreecommitdiff
path: root/fd.c
blob: 9cf8026d45854ee796cc5c2c0010eb3d7879cc01 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
/* ************************************************************ *\
 *								*
 *    Support routines for file descriptors (FD) 		*
 *								*
 *	James Peterson, 1987  	 				*
 * Copyright (C) 1987 MCC
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of MCC not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  MCC makes no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * MCC DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL MCC BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 * 				  				*
 * 				  				*
 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 \* *********************************************************** */

#include <X11/Xpoll.h>	       /* for XFD_* macros - must come before
				  scope.h include to avoid INT32 clash */

#include "scope.h"

#include <unistd.h>
#include <sys/uio.h>	       /* for struct iovec, used by socket.h */
#include <sys/socket.h>	       /* for AF_INET, SOCK_STREAM, ... */
#include <sys/ioctl.h>	       /* for FIONCLEX, FIONBIO, ... */
#if !defined(FIOCLEX) && defined(HAVE_SYS_FILIO_H)
#include <sys/filio.h>
#endif
#include <fcntl.h>
#include <netinet/in.h>	       /* struct sockaddr_in */
#include <sys/un.h>	       /* struct sockaddr_un */
#include <netinet/tcp.h>
#include <netdb.h>	       /* struct servent * and struct hostent * */
#include <errno.h>	       /* for EINTR, EADDRINUSE, ... */

#ifndef USE_XTRANS
#include <arpa/inet.h>	       /* for inet_addr */
#endif

/*
  All of this code is to support the handling of file descriptors (FD).
  The idea is to keep a table of the FDs that are in use and why.
  For each FD that is open for input, we keep the name of a procedure
  to call if input arrives for that FD.  When an FD is created
  (by an open, pipe, socket, ...) declare that by calling UsingFD.
  When it is no longer in use (close ...), call NotUsingFD.
*/

/* ************************************************************ */
/*								*/
/*								*/
/* ************************************************************ */

void
InitializeFD(void)
{
  int  i;

  enterprocedure("InitializeFD");
  /* get the number of file descriptors the system will let us use */
#ifdef _SC_OPEN_MAX
  MaxFD = sysconf(_SC_OPEN_MAX);
#elif defined(HAVE_GETDTABLESIZE)
  MaxFD = getdtablesize();
#else
  MaxFD = _NFILE - 1;
#endif
  if (MaxFD > FD_SETSIZE) {
      MaxFD = FD_SETSIZE;
  }

  /* allocate space for a File Descriptor (FD) Table */
  FDD = calloc (MaxFD, sizeof (struct FDDescriptor));
  if (FDD == NULL) {
      panic("Can't allocate memory for file descriptor table");
  }
  FDinfo = calloc(MaxFD, sizeof (struct fdinfo));
  if (FDinfo == NULL) {
      panic("Can't allocate memory for file descriptor info table");
  }

  /* be sure all fd's are closed and marked not busy */
  for (i = 0; i < MaxFD; i++)
    {
      /* 0, 1, 2 are special (stdin, stdout, stderr) */
      if (i > 2)
	close(i);
      /* FDD[i].Busy = false; - not needed since false==0*/
    }

  /* save one FD for single file input or output like debugging */
  /* also the getservbyname call is currently using an FD */
  MaxFD -= 4;

  nFDsInUse = 0 /* stdin, stdout, stderr */ ;
  FD_ZERO(&ReadDescriptors);
  HighestFD = 0;

  UsingFD(fileno(stdin),  NULL, NULL, NULL);
  UsingFD(fileno(stdout), NULL, NULL, NULL);
  UsingFD(fileno(stderr), NULL, NULL, NULL);
}

/* ************************************************************ */

void
UsingFD(
    FD fd,
    void     (*Handler)(int),
    void     (*FlushHandler)(int),
    XtransConnInfo trans_conn)
{
  if (FDD[fd].Busy)
    NotUsingFD(fd);
  nFDsInUse += 1;

  FDD[fd].Busy = true;
  FDD[fd].InputHandler = Handler;
  FDD[fd].FlushHandler = FlushHandler;
#ifdef USE_XTRANS
  FDD[fd].trans_conn = trans_conn;
#endif
  if (Handler == NULL)
    FD_CLR(fd,&ReadDescriptors) /* clear fd bit */ ;
  else
    FD_SET(fd,&ReadDescriptors) /* set fd bit */ ;

  if (fd > HighestFD)
    HighestFD = fd;

  if (nFDsInUse >= MaxFD)
    panic("no more FDs");

  debug(128,(stderr, "Using FD %d, %d of %d in use\n", fd, nFDsInUse, MaxFD));
}

/* ************************************************************ */

void
NotUsingFD(
    FD fd)
{
  debug(128,(stderr, "Not Using FD %d\n", fd));

  if (FDD[fd].Busy)
    nFDsInUse -= 1;

  FDD[fd].Busy = false;
  FD_CLR(fd,&ReadDescriptors) /* clear fd bit */ ;

  while (!FDD[HighestFD].Busy && HighestFD > 0)
    HighestFD -= 1;

  debug(128,(stderr, "Highest FD %d, in use %d\n", HighestFD, nFDsInUse));
}

/* ************************************************************ */

#ifdef USE_XTRANS
XtransConnInfo GetXTransConnInfo(FD fd)
{
    return FDD[fd].trans_conn;
}
#endif

/* ************************************************************ */

static void
EOFonFD (
    FD fd)
{
  enterprocedure("EOFonFD");
  debug(128,(stderr, "EOF on %d\n", fd));
#ifdef USE_XTRANS
  if (FDD[fd].trans_conn) 
      _X11TransClose(FDD[fd].trans_conn);
  else
#endif
  close(fd);
  NotUsingFD(fd);
}

FD
AcceptConnection (
    FD  ConnectionSocket)
{
  FD ClientFD;
  struct sockaddr_in from;
  socklen_t len = sizeof (from);
  int	 tmp = 1;

  enterprocedure("ConnectToClient");

  ClientFD = accept(ConnectionSocket, (struct sockaddr *)&from, &len);
  debug(4,(stderr, "Connect To Client: FD %d\n", ClientFD));
  if (ClientFD < 0 && errno == EWOULDBLOCK)
    {
      debug(4,(stderr, "Almost blocked accepting FD %d\n", ClientFD));
      panic("Can't connect to Client");
    }
  if (ClientFD < 0)
    {
      debug(4,(stderr, "NewConnection: error %d\n", errno));
      panic("Can't connect to Client");
    }

#ifdef FD_CLOEXEC
  (void)fcntl(ClientFD, F_SETFD, FD_CLOEXEC);
#else
  (void)ioctl(ClientFD, FIOCLEX, 0);
#endif
  /* ultrix reads hang on Unix sockets, hpux reads fail */
#if defined(O_NONBLOCK) && (!defined(ultrix) && !defined(hpux))
  (void) fcntl (ClientFD, F_SETFL, O_NONBLOCK);
#else
#ifdef FIOSNBIO
  ioctl (ClientFD, FIOSNBIO, &ON);
#else
  (void) fcntl (ClientFD, F_SETFL, FNDELAY);
#endif
#endif
  (void) setsockopt(ClientFD, IPPROTO_TCP, TCP_NODELAY, (char *) &tmp, sizeof (int));
  return(ClientFD);
}

FD
MakeConnection(
    const char *server,
    short port,
    int	report,
    XtransConnInfo *trans_conn  /* transport connection object */
    )
{
  FD ServerFD;
#ifdef USE_XTRANS
  char address[256];
  int connect_stat;
  const char *protocols[] = {"local", "unix", "tcp", "inet6", "inet", NULL};
  const char **s;

  enterprocedure("ConnectToServer");
  s = protocols;
  while (*s) {
    *trans_conn = NULL;
    snprintf (address, sizeof(address), "%s/%s:%ld", *s++, server, port - ServerBasePort);
    debug(4,(stderr, "Trying %s ", address));
    *trans_conn = _X11TransOpenCOTSClient(address);
    if(*trans_conn == NULL) {
        debug(1,(stderr, "OpenCOTSClient %s failed\n", address));
        continue;
    }
    debug(4,(stderr, "Opened "));
    if ((connect_stat = _X11TransConnect(*trans_conn,address)) < 0 ) {
        if ((connect_stat != TRANS_TRY_CONNECT_AGAIN) ||
            (_X11TransConnect(*trans_conn,address) < 0 )) {
            _X11TransClose(*trans_conn);
            *trans_conn = NULL;
            debug(1,(stderr, "TransConnect %s failed\n", address));
            continue;
        }
    }
    debug(4,(stderr, "Connected\n"));
    break;
  }
  if (*trans_conn == NULL) {
    panic("Can't open connection to Server");
  }

  ServerFD = _X11TransGetConnectionNumber(*trans_conn);
#else /* !USE_XTRANS */
  char HostName[512];
  struct sockaddr_in  sin;
  struct sockaddr_un  sun;
  struct sockaddr     *saddr;
  int		      salen;
  struct hostent *hp;
  int tmp = 1;
#ifndef	SO_DONTLINGER
  struct linger linger;
#endif /* SO_DONTLINGER */

  enterprocedure("ConnectToServer");

  /* establish a socket to the name server for this host */
  /* determine the host machine for this process */
  if (*server == '\0')
  {
    sun.sun_family = AF_UNIX;
    sprintf (sun.sun_path, "/tmp/.X11-unix/X%d", port - 6000);
    salen = sizeof (sun.sun_family) + strlen (sun.sun_path) + 1;
    saddr = (struct sockaddr *) &sun;
  }
  else
  {
    debug(4,(stderr, "try to connect on %s\n", server));
  
    bzero((char *)&sin, sizeof(sin));
    sin.sin_addr.s_addr = inet_addr (server);
    if ((long) sin.sin_addr.s_addr == -1)
    {
	hp = gethostbyname(server);
	if (hp == 0)
	  {
	    perror("gethostbyname failed");
	    debug(1,(stderr, "gethostbyname failed for %s\n", server));
	    panic("Can't open connection to Server");
	  }
	bcopy((char *)hp->h_addr, (char *)&sin.sin_addr, hp->h_length);
    }
  
    sin.sin_family = AF_INET;
  
    if (port == ScopePort
	&& strcmp(server, ScopeHost) == 0)
      {
	char error_message[100];
	(void)sprintf(error_message, "Trying to attach to myself: %s,%d\n",
		server, sin.sin_port);
	panic(error_message);
      }
  
    sin.sin_port = htons (port);
    salen = sizeof (sin);
    saddr = (struct sockaddr *) &sin;
  }

  ServerFD = socket(saddr->sa_family, SOCK_STREAM, 0);
  if (ServerFD < 0)
    {
      perror("socket() to Server failed");
      debug(1,(stderr, "socket failed\n"));
      panic("Can't open connection to Server");
    }
  (void) setsockopt(ServerFD, SOL_SOCKET, SO_REUSEADDR,  (char *) NULL, 0);
#ifdef SO_USELOOPBACK
  (void) setsockopt(ServerFD, SOL_SOCKET, SO_USELOOPBACK,(char *) NULL, 0);
#endif
  (void) setsockopt(ServerFD, IPPROTO_TCP, TCP_NODELAY, (char *) &tmp, sizeof (int));
#ifdef	SO_DONTLINGER
  (void) setsockopt(ServerFD, SOL_SOCKET, SO_DONTLINGER, (char *) NULL, 0);
#else /* SO_DONTLINGER */
  linger.l_onoff = 0;
  linger.l_linger = 0;
  (void) setsockopt(ServerFD, SOL_SOCKET, SO_LINGER, (char *)&linger, sizeof linger);
#endif /* SO_DONTLINGER */

  /* ******************************************************** */
  /* try to connect to Server */

  if (connect(ServerFD, saddr, salen) < 0)
    {
      debug(4,(stderr, "connect returns errno of %d\n", errno));
      if (errno != 0)
	if (report)
	  perror("connect");
      switch (errno)
	{
	case ECONNREFUSED:
	  /* experience says this is because there is no Server
	     to connect to */
	  (void)close(ServerFD);
	  debug(1,(stderr, "No Server\n"));
	  if (report)
	    warn("Can't open connection to Server");
	  return(-1);

	default:
	  (void)close(ServerFD);
	  panic("Can't open connection to Server");
	}
    }
#endif /* USE_XTRANS */

  debug(4,(stderr, "Connect To Server: FD %d\n", ServerFD));
  return(ServerFD);
}
  
/* ************************************************************ */
/*								*/
/*     Main Loop -- wait for input from any source and Process  */
/*								*/
/* ************************************************************ */

int
MainLoop(void)
{
  enterprocedure("MainLoop");

  while (true)
    {
      fd_set  rfds, wfds, xfds;
      short   nfds;
      short   fd;

      /* wait for something */

      /* rfds = ReadDescriptors & ~BlockedReadDescriptors; */
      rfds = ReadDescriptors;
      XFD_UNSET(&rfds, &BlockedReadDescriptors);

      xfds = rfds;

      /* wfds = ReadDescriptors & WriteDescriptors; */
      XFD_ANDSET(&wfds, &ReadDescriptors, &WriteDescriptors);

      debug(128,(stderr, "select %d, rfds = %#lx, wfds = %#lx, RD=%#lx, BRD=%#lx, WD=%#lx\n",
                 HighestFD + 1, __XFDS_BITS(&rfds, 0), __XFDS_BITS(&wfds, 0),
                 __XFDS_BITS(&ReadDescriptors, 0),
                 __XFDS_BITS(&BlockedReadDescriptors, 0),
                 __XFDS_BITS(&WriteDescriptors, 0)));

      if (Interrupt || (!XFD_ANYSET(&rfds) && !XFD_ANYSET(&wfds)))
      {
	ReadCommands ();
	Interrupt = 0;
	continue;
      }
      nfds = select(HighestFD + 1, &rfds, &wfds, &xfds, (struct timeval *)NULL);
      debug(128,(stderr, "select nfds = %d, rfds = %#lx, wfds = %#lx, xfds = %#lx\n",
		 nfds, __XFDS_BITS(&rfds, 0), __XFDS_BITS(&wfds, 0),
                 __XFDS_BITS(&xfds, 0)));

      if (nfds < 0)
	{
	  if (errno == EINTR)
	    continue /* to end of while loop */ ;
	  debug(1,(stderr, "Bad select - errno = %d\n", errno));
	  if (errno == EBADF)
	    {
	      /* one of the bits in rfds is invalid, close down
		 files until it goes away */
	      EOFonFD(HighestFD);
	      continue;
	    }

	  if (Interrupt)
	  {
	    ReadCommands ();
	    Interrupt = 0;
	  }
	  else
	  {
	    panic("Select returns error");
	  }
	  continue /* to end of while loop */ ;
	}

      if (nfds == 0)
	{
	  TimerExpired();
	  continue;
	}

      /* check each fd to see if it has input */
      for (fd = 0; fd <= HighestFD; fd++)
	{
	  /*
	    check all returned fd's; this prevents
	    starvation of later clients by earlier clients
	  */

	  if (FD_ISSET(fd,&rfds))
	  {
	    if (FDD[fd].InputHandler == NULL)
	      {
		panic("FD selected with no handler");
		debug(1,(stderr, "FD %d has NULL handler\n", fd));
	      }
	    else
	      (FDD[fd].InputHandler)(fd);
	  }
	  if (FD_ISSET(fd,&wfds))
	  {
	    if (FDD[fd].FlushHandler == NULL)
	    {
	      panic("FD selected with no flush handler");
	    }
	    else
	      (FDD[fd].FlushHandler)(fd);
	  }
	}
    }
  return 0;
}