aboutsummaryrefslogtreecommitdiffstats
path: root/src/gammad.c
blob: 3d2d26160cb62660e7d4df0442d620a8a461e2e9 (plain) (blame)
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
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
/**
 * gammad -- Cooperative gamma server
 * Copyright (C) 2016  Mattias Andrée (maandree@kth.se)
 * 
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <libgamma.h>

#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "arg.h"
#include "output.h"
#include "util.h"
#include "server.h"



/**
 * The name of the process
 */
char* argv0;

/**
 * Array of all outputs
 */
struct output* outputs = NULL;

/**
 * The nubmer of elements in `outputs`
 */
size_t outputs_n = 0;

/**
 * The server socket's file descriptor
 */
int socketfd = -1;

/**
 * The pathname of the PID file
 */
char* pidpath = NULL;

/**
 * The pathname of the socket
 */
char* socketpath = NULL;

/**
 * Error code returned by libgamma
 */
int gerror;

/**
 * Initialisation stage
 * 
 * Used to keep track on what to destroy, of those things that
 * must only be destroyed if they have been initialised
 */
int init_stage = 0;

/**
 * The libgamma site state
 */
libgamma_site_state_t site;

/**
 * The libgamma partition states
 */
libgamma_partition_state_t* partitions = NULL;

/**
 * The libgamma CRTC states
 */
libgamma_crtc_state_t* crtcs = NULL;

/**
 * Has the process receive a signal
 * telling it to re-execute?
 */
volatile sig_atomic_t reexec = 0;

/**
 * Has the process receive a signal
 * telling it to terminate?
 */
volatile sig_atomic_t terminate = 0;



/**
 * Called when the process receives
 * a signal telling it to re-execute
 * 
 * @param  signo The received signal
 */
static void sig_reexec(int signo)
{
  reexec = 1;
  (void) signo;
}


/**
 * Called when the process receives
 * a signal telling it to terminate
 * 
 * @param  signo The received signal
 */
static void sig_terminate(int signo)
{
  terminate = 1;
  (void) signo;
}


/**
 * Get the pathname of the runtime file
 * 
 * @param   suffix  The suffix for the file
 * @return          The pathname of the file, `NULL` on error
 */
static char* get_pathname(const char* suffix)
{
  const char* rundir = getenv("XDG_RUNTIME_DIR");
  const char* username = "";
  char* name = NULL;
  char* p;
  char* rc;
  struct passwd* pw;
  size_t n;
  int saved_errno;
  
  if (site.site)
    {
      name = memdup(site.site, strlen(site.site) + 1);
      if (name == NULL)
	goto fail;
    }
  else if ((name = libgamma_method_default_site(site.method)))
    {
      name = memdup(name, strlen(name) + 1);
      if (name == NULL)
	goto fail;
    }
  
  if (name != NULL)
    switch (site.method)
      {
      case LIBGAMMA_METHOD_X_RANDR:
      case LIBGAMMA_METHOD_X_VIDMODE:
	if ((p = strrchr(name, ':')))
	  if ((p = strchr(p, '.')))
	    *p = '\0';
      default:
	break;
      }
  
  if (!rundir || !*rundir)
    rundir = "/tmp";
  
  if ((pw = getpwuid(getuid())))
    username = pw->pw_name ? pw->pw_name : "";
  
  n = sizeof("/.gammad/~/.") + 3 * sizeof(int);
  n += strlen(rundir) + strlen(username) + strlen(name) + strlen(suffix);
  if (!(rc = malloc(n)))
    goto fail;
  sprintf(rc, "%s/.gammad/~%s/%i%s%s%s",
	  rundir, username, site.method, name ? "." : "", name ? name : "", suffix);
  return rc;
  
 fail:
  saved_errno = errno;
  free(name);
  errno = saved_errno;
  return NULL;
}


/**
 * Get the pathname of the socket
 * 
 * @return  The pathname of the socket, `NULL` on error
 */
static inline char* get_socket_pathname(void)
{
  return get_pathname(".socket");
}


/**
 * Get the pathname of the PID file
 * 
 * @return  The pathname of the PID file, `NULL` on error
 */
static inline char* get_pidfile_pathname(void)
{
  return get_pathname(".pid");
}


/**
 * Parse adjustment method name (or stringised number)
 * 
 * @param   arg  The adjustment method name (or stringised number)
 * @return       The adjustment method, -1 (negative) on error
 */
static int get_method(char* arg)
{
#if LIBGAMMA_METHOD_MAX > 5
# warning libgamma has added more adjustment methods
#endif
  
  char* p;
  
  if (!strcmp(arg, "dummy"))    return LIBGAMMA_METHOD_DUMMY;
  if (!strcmp(arg, "randr"))    return LIBGAMMA_METHOD_X_RANDR;
  if (!strcmp(arg, "vidmode"))  return LIBGAMMA_METHOD_X_VIDMODE;
  if (!strcmp(arg, "drm"))      return LIBGAMMA_METHOD_LINUX_DRM;
  if (!strcmp(arg, "gdi"))      return LIBGAMMA_METHOD_W32_GDI;
  if (!strcmp(arg, "quartz"))   return LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS;
  
  if (!*arg || (/* avoid overflow: */ strlen(arg) > 4))
    goto bad;
  for (p = arg; *p; p++)
    if (('0' > *p) || (*p > '9'))
      goto bad;
  
  return atoi(arg);
  
 bad:
  fprintf(stderr, "%s: unrecognised adjustment method name: %s\n", argv0, arg);
  errno = 0;
  return -1;
}


/**
 * Get the name of a CRTC
 * 
 * @param   info  Information about the CRTC
 * @param   crtc  libgamma's state for the CRTC
 * @return        The name of the CRTC, `NULL` on error
 */
static char* get_crtc_name(libgamma_crtc_information_t* info, libgamma_crtc_state_t* crtc)
{
  if ((info->edid_error == 0) && (info->edid != NULL))
    return libgamma_behex_edid(info->edid, info->edid_length);
  else if ((info->connector_name_error == 0) && (info->connector_name != NULL))
    {
      char* name = malloc(3 * sizeof(size_t) + strlen(info->connector_name) + 2);
      if (name != NULL)
	sprintf(name, "%zu.%s", crtc->partition->partition, info->connector_name);
      return name;
    }
  else
    {
      char* name = malloc(2 * 3 * sizeof(size_t) + 2);
      if (name != NULL)
	sprintf(name, "%zu.%zu", crtc->partition->partition, crtc->crtc);
      return name;
    }
}


/**
 * Check whether a PID file is outdated
 * 
 * @param   pidfile  The PID file
 * @param   token    An environment variable (including both key and value)
 *                   that must exist in the process if it is a gammad process
 * @return           -1: An error occurred
 *                    0: The service is already running
 *                    1: The PID file is outdated
 */
static int is_pidfile_reusable(const char* pidfile, const char* token)
{
  /* PORTERS: /proc/$PID/environ is Linux specific */
  
  char temp[sizeof("/proc//environ") + 3 * sizeof(pid_t)];
  int fd = -1, saved_errno, tries = 0;
  char* content = NULL;
  char* p;
  pid_t pid = 0;
  size_t n;
#if defined(HAVE_LINUX_PROCFS)
  char* end;
#else
  (void) token;
#endif
  
  /* Get PID */
 retry:
  fd = open(pidfile, O_RDONLY);
  if (fd < 0)
    return -1;
  content = nread(fd, &n);
  if (content == NULL)
    goto fail;
  close(fd), fd = -1;
  
  if (n == 0)
    {
      if (++tries > 1)
	goto bad;
      msleep(100); /* 1 tenth of a second */
      goto retry;
    }
  
  if (('0' > content[0]) || (content[0] > '9'))
    goto bad;
  if ((content[0] == '0') && ('0' <= content[1]) && (content[1] <= '9'))
    goto bad;
  for (p = content; *p; p++)
    if (('0' <= *p) && (*p <= '9'))
      pid = pid * 10 + (*p & 15);
    else
      break;
  if (*p++ != '\n')
    goto bad;
  if (*p)
    goto bad;
  if ((size_t)(content - p) != n)
    goto bad;
  sprintf(temp, "%llu", (unsigned long long)pid);
  if (strcmp(content, temp))
    goto bad;
  
  /* Validate PID */
#if defined(HAVE_LINUX_PROCFS)
  sprintf(temp, "/proc/%llu/environ", (unsigned long long)pid);
  fd = open(temp, O_RDONLY);
  if (fd < 0)
    return ((errno == ENOENT) || (errno == EACCES)) ? 1 : -1;
  content = nread(fd, &n);
  if (content == NULL)
    goto fail;
  close(fd), fd = -1;
  
  for (end = (p = content) + n; p != end; p = strchr(p, '\0') + 1)
    if (!strcmp(p, token))
      return 0;
#else
  if ((kill(pid, 0) == 0) || (errno == EINVAL))
    return 0;
#endif
  
  return 1;
 bad:
  fprintf(stderr, "%s: pid file contain invalid content: %s\n", argv0, pidfile);
  errno = 0;
  return -1;
 fail:
  saved_errno = errno;
  free(content);
  if (fd >= 0)
    close(fd);
  errno = saved_errno;
  return -1;
}


/**
 * Create PID file
 * 
 * @param   pidfile  The pathname of the PID file
 * @return           Zero on success, -1 on error,
 *                   -2 if the service is already running
 */
static int create_pidfile(char* pidfile)
{
  int fd, r, saved_errno;
  char* p;
  char* token;
  
  /* Create token used to validate the service. */
  token = malloc(sizeof("GAMMAD_PIDFILE_TOKEN=") + strlen(pidfile));
  if (token == NULL)
    return -1;
  sprintf(token, "GAMMAD_PIDFILE_TOKEN=%s", pidfile);
  if (putenv(token))
    return -1;
  
  /* Create PID file's directory. */
  for (p = pidfile; *p == '/'; p++);
  while ((p = strchr(p, '/')))
    {
      *p = '\0';
      if (mkdir(pidfile, 0644) < 0)
	if (errno != EEXIST)
	  return -1;
      *p++ = '/';
    }
  
  /* Create PID file. */
 retry:
  fd = open(pidfile, O_CREAT | O_EXCL, 0644);
  if (fd < 0)
    {
      if (errno == EINTR)
	goto retry;
      if (errno != EEXIST)
	return -1;
      r = is_pidfile_reusable(pidfile, token);
      if (r > 0)
	{
	  unlink(pidfile);
	  goto retry;
	}
      else if (r < 0)
	goto fail;
      fprintf(stderr, "%s: service is already running\n", argv0);
      errno = 0;
      return -2;
    }
  
  /* Write PID to PID file. */
  if (dprintf(fd, "%llu\n", (unsigned long long)getpid()) < 0)
    goto fail;
  
  /* Done */
  if (close(fd) < 0)
    if (errno != EINTR)
      return -1;
  return 0;
 fail:
  saved_errno = errno;
  close(fd);
  unlink(pidfile);
  errno = saved_errno;
  return -1;
}


/**
 * Initialise the process
 * 
 * @param   method       The adjustment method, -1 for automatic
 * @param   sitename     The site's name, may be `NULL`
 * @param   preserve     Preserve current gamma ramps at priority 0
 * @param   foreground   Keep process in the foreground
 * @param   keep_stderr  Keep stderr open
 * @return               1: Success
 *                       2: Normal failure
 *                       3: Libgamma failure
 *                       4: The service is already running
 *                       Otherwise: The negative of the exit value the
 *                       process should have and shall exit immediately
 */
static int initialise(int method, const char *sitename, int preserve, int foreground, int keep_stderr)
{
  struct sockaddr_un address;
  struct rlimit rlimit;
  size_t i, j, n, n0;
  sigset_t mask;
  char* sitename_dup = NULL;
  int r;
  
  /* Zero out some memory so it can be destoried safely. */
  memset(&site, 0, sizeof(site));
  
  /* Close all file descriptors above stderr */
  if (getrlimit(RLIMIT_NOFILE, &rlimit) || (rlimit.rlim_cur == RLIM_INFINITY))
    n = 4 << 10;
  else
    n = (size_t)(rlimit.rlim_cur);
  for (i = STDERR_FILENO + 1; i < n; i++)
    close((int)i);
  
  /* Set umask, reset signal handlers, and reset signal mask */
  umask(0);
  for (r = 1; r < _NSIG; r++)
    signal(r, SIG_DFL);
  if (sigfillset(&mask))
    perror(argv0);
  else
    sigprocmask(SIG_UNBLOCK, &mask, NULL);
  
  /* Get method */
  if ((method < 0) && (libgamma_list_methods(&method, 1, 0) < 1))
    return fprintf(stderr, "%s: no adjustment method available\n", argv0), -1;
  
  /* Get site */
  if (sitename != NULL)
    if (!(sitename_dup = memdup(sitename, strlen(sitename) + 1)))
      goto fail;
  if ((gerror = libgamma_site_initialise(&site, method, sitename_dup)))
    goto fail_libgamma;
  
  /* Get PID file and socket pathname */
  if (!(pidpath = get_pidfile_pathname()))
    goto fail;
  if (!(socketpath = get_socket_pathname()))
    goto fail;
  
  /* Create PID file */
  if ((r = create_pidfile(pidpath)) < 0)
    {
      free(pidpath), pidpath = NULL;
      if (r == -2)
	goto already_running;
      goto fail;
    }
  
  /* Get partitions */
  if (site.partitions_available)
    if (!(partitions = calloc(site.partitions_available, sizeof(*partitions))))
      goto fail;
  for (i = 0; i < site.partitions_available; i++)
    {
      if ((gerror = libgamma_partition_initialise(partitions + i, &site, i)))
	goto fail_libgamma;
      outputs_n += partitions[i].crtcs_available;
    }
  
  /* Get CRTC:s */
  if (outputs_n)
    if (!(crtcs = calloc(outputs_n, sizeof(*crtcs))))
      goto fail;
  for (i = 0, j = n = 0; i < site.partitions_available; i++)
    for (n0 = n, n += partitions[i].crtcs_available; j < n; j++)
      if ((gerror = libgamma_crtc_initialise(crtcs + j, partitions + i, j - n0)))
	goto fail_libgamma;
  
  /* Get CRTC information */
  if (outputs_n)
    if (!(outputs = calloc(outputs_n, sizeof(*outputs))))
      goto fail;
  for (i = 0; i < outputs_n; i++)
    {
      libgamma_crtc_information_t info;
      int saved_errno;
      libgamma_get_crtc_information(&info, crtcs + i,
				    LIBGAMMA_CRTC_INFO_EDID |
				    LIBGAMMA_CRTC_INFO_MACRO_RAMP |
				    LIBGAMMA_CRTC_INFO_GAMMA_SUPPORT |
				    LIBGAMMA_CRTC_INFO_CONNECTOR_NAME);
      outputs[i].depth       = info.gamma_depth_error   ? 0 : info.gamma_depth;
      outputs[i].red_size    = info.gamma_size_error    ? 0 : info.red_gamma_size;
      outputs[i].green_size  = info.gamma_size_error    ? 0 : info.green_gamma_size;
      outputs[i].blue_size   = info.gamma_size_error    ? 0 : info.blue_gamma_size;
      outputs[i].supported   = info.gamma_support_error ? 0 : info.gamma_support;
      if (outputs[i].depth      == 0 || outputs[i].red_size  == 0 ||
	  outputs[i].green_size == 0 || outputs[i].blue_size == 0)
	outputs[i].supported = 0;
      outputs[i].name        = get_crtc_name(&info, crtcs + i);
      saved_errno = errno;
      outputs[i].crtc        = crtcs + i;
      libgamma_crtc_information_destroy(&info);
      outputs[i].ramps_size = outputs[i].red_size + outputs[i].green_size + outputs[i].blue_size;
      /* outputs[i].ramps_size will be multipled by the stop-size later */
      errno = saved_errno;
      if (outputs[i].name == NULL)
	goto fail;
    }
  free(crtcs), crtcs = NULL;
  
  /* Sort outputs */
  qsort(outputs, outputs_n, sizeof(*outputs), output_cmp_by_name);
  
  /* Load current gamma ramps */
#define LOAD_RAMPS(SUFFIX, MEMBER) \
  do \
    { \
      libgamma_gamma_ramps##SUFFIX##_initialise(&(outputs[i].saved_ramps.MEMBER)); \
      gerror = libgamma_crtc_get_gamma_ramps##SUFFIX(outputs[i].crtc, &(outputs[i].saved_ramps.MEMBER)); \
      if (gerror) \
	{ \
	  libgamma_perror(argv0, gerror); \
	  outputs[i].supported = LIBGAMMA_NO; \
	  libgamma_gamma_ramps##SUFFIX##_destroy(&(outputs[i].saved_ramps.MEMBER)); \
	  memset(&(outputs[i].saved_ramps.MEMBER), 0, sizeof(outputs[i].saved_ramps.MEMBER)); \
	} \
    } \
  while (0)
  for (i = 0; i < outputs_n; i++)
    if (outputs[i].supported != LIBGAMMA_NO)
      switch (outputs[i].depth)
	{
	case 8:
	  outputs[i].ramps_size *= sizeof(uint8_t);
	  LOAD_RAMPS(8, u8);
	  break;
	case 16:
	  outputs[i].ramps_size *= sizeof(uint16_t);
	  LOAD_RAMPS(16, u16);
	  break;
	case 32:
	  outputs[i].ramps_size *= sizeof(uint32_t);
	  LOAD_RAMPS(32, u32);
	  break;
	default:
	  outputs[i].depth = 64;
	  /* fall through */
	case 64:
	  outputs[i].ramps_size *= sizeof(uint64_t);
	  LOAD_RAMPS(64, u64);
	  break;
	case -1:
	  outputs[i].ramps_size *= sizeof(float);
	  LOAD_RAMPS(f, f);
	  break;
	case -2:
	  outputs[i].ramps_size *= sizeof(double);
	  LOAD_RAMPS(d, d);
	  break;
	}
  
  /* Preserve current gamma ramps at priority=0 if -p */
  if (preserve)
    for (i = 0; i < outputs_n; i++)
      {
	struct filter filter = {
	  .client   = -1,
	  .crtc     = NULL,
	  .priority = 0,
	  .class    = NULL,
	  .lifespan = LIFESPAN_UNTIL_REMOVAL,
	  .ramps    = NULL
	};
	outputs[i].table_filters = calloc(4, sizeof(*(outputs[i].table_filters)));
	outputs[i].table_sums = calloc(4, sizeof(*(outputs[i].table_sums)));
	outputs[i].table_alloc = 4;
	outputs[i].table_size = 1;
	filter.class = memdup(PKGNAME "::" COMMAND "::preserved", sizeof(PKGNAME "::" COMMAND "::preserved"));
	if (filter.class == NULL)
	  goto fail;
	filter.ramps = memdup(outputs[i].saved_ramps.u8.red, outputs[i].ramps_size);
	if (filter.ramps == NULL)
	  goto fail;
	outputs[i].table_filters[0] = filter;
	COPY_RAMP_SIZES(&(outputs[i].table_sums[0].u8), outputs + i);
	if (!gamma_ramps_unmarshal(outputs[i].table_sums, outputs[i].saved_ramps.u8.red, outputs[i].ramps_size))
	  goto fail;
      }
  
  /* Create socket and start listening */
  address.sun_family = AF_UNIX;
  if (strlen(socketpath) >= sizeof(address.sun_path))
    {
      errno = ENAMETOOLONG;
      goto fail;
    }
  strcpy(address.sun_path, socketpath);
  unlink(socketpath);
  if ((socketfd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
    goto fail;
  if (fchmod(socketfd, S_IRWXU) < 0)
    goto fail;
  if (bind(socketfd, (struct sockaddr*)(&address), sizeof(address)) < 0)
    goto fail;
  if (listen(socketfd, SOMAXCONN) < 0)
    goto fail;
  
  /* Change directory to / to avoid blocking umounting */
  if (chdir("/") < 0)
    perror(argv0);
  
  /* Set up signal handlers */
  if (signal(SIGUSR1, sig_reexec) == SIG_ERR)
    goto fail;
  if (signal(SIGTERM, sig_terminate) == SIG_ERR)
    goto fail;
  
  /* Initialise the server */
  if (server_initialise() < 0)
    goto fail;
  init_stage++;
  
  /* Place in the background unless -f */
  if (foreground == 0)
    {
      pid_t pid;
      int fd = -1, saved_errno;
      int notify_rw[2] = { -1, -1 };
      char a_byte = 0;
      ssize_t got;
      
      if (pipe(notify_rw) < 0)
	goto fail;
      if (notify_rw[0] <= STDERR_FILENO)
	if ((notify_rw[0] = dup2atleast(notify_rw[0], STDERR_FILENO + 1)) < 0)
	  goto fail_background;
      if (notify_rw[1] <= STDERR_FILENO)
	if ((notify_rw[1] = dup2atleast(notify_rw[1], STDERR_FILENO + 1)) < 0)
	  goto fail_background;
      
      switch ((pid = fork()))
	{
	case -1:
	  goto fail_background;
	case 0:
	  /* Child */
	  close(notify_rw[0]), notify_rw[0] = -1;
	  if (setsid() < 0)
	    goto fail_background;
	  switch ((pid = fork()))
	    {
	    case -1:
	      goto fail_background;
	    case 0:
	      /* Replace std* with /dev/null */
	      fd = open("/dev/null", O_RDWR);
	      if (fd < 0)
		goto fail;
#define xdup2(s, d)  do if (s != d) { close(d); if (dup2(s, d) < 0) goto fail; } while (0)
	      xdup2(fd, STDIN_FILENO);
	      xdup2(fd, STDOUT_FILENO);
	      if (keep_stderr)
		xdup2(fd, STDERR_FILENO);
	      if (fd > STDERR_FILENO)
		close(fd);
	      fd = -1;
	      
	      /* Update PID file */
	      fd = open(pidpath, O_WRONLY);
	      if (fd < 0)
		goto fail_background;
	      if (dprintf(fd, "%llu\n", (unsigned long long)getpid()) < 0)
		goto fail_background;
	      close(fd), fd = -1;
	      
	      /* Notify */
	      if (write(notify_rw[1], &a_byte, 1) <= 0)
		goto fail_background;
	      close(notify_rw[1]);
	      break;
	    default:
	      /* Parent */
	      return 0;
	    }
	  break;
	default:
	  /* Parent */
	  close(notify_rw[1]), notify_rw[1] = -1;
	  got = read(notify_rw[0], &a_byte, 1);
	  if (got < 0)
	    goto fail_background;
	  close(notify_rw[0]);
	  return -(got == 0);
	}
      
      goto done_background;
    fail_background:
      saved_errno = errno;
      if (fd >= 0)            close(fd);
      if (notify_rw[0] >= 0)  close(notify_rw[0]);
      if (notify_rw[1] >= 0)  close(notify_rw[1]);
      errno = saved_errno;
    done_background:;
    }
  else
    {
      /* Signal the spawner that the service is ready */
      close(STDOUT_FILENO);
      /* Avoid potential catastrophes that would occur if a library that is being
       * used was so mindless as to write to stdout. */
      if (dup2(STDERR_FILENO, STDOUT_FILENO) < 0)
	perror(argv0);
    }
  
  return 1;
 fail:
  return 2;
 fail_libgamma:
  return 3;
 already_running:
  return 4;
}


/**
 * Deinitialise the process
 */
static void destroy(void)
{
  size_t i;
  
  if (init_stage >= 1)
    server_destroy(1);
  if (socketfd >= 0)
    {
      shutdown(socketfd, SHUT_RDWR);
      close(socketfd);
      unlink(socketpath);
    }
#define RESTORE_RAMPS(SUFFIX, MEMBER) \
  do \
    if (outputs[i].saved_ramps.MEMBER.red != NULL) \
      { \
	gerror = libgamma_crtc_set_gamma_ramps##SUFFIX(outputs[i].crtc, outputs[i].saved_ramps.MEMBER); \
	if (gerror) \
	    libgamma_perror(argv0, gerror); \
      } \
  while (0)
  if (outputs != NULL)
    for (i = 0; i < outputs_n; i++)
      {
	if (outputs[i].supported != LIBGAMMA_NO)
	  switch (outputs[i].depth)
	    {
	    case 8:
	      RESTORE_RAMPS(8, u8);
	      break;
	    case 16:
	      RESTORE_RAMPS(16, u16);
	      break;
	    case 32:
	      RESTORE_RAMPS(32, u32);
	      break;
	    case 64:
	      RESTORE_RAMPS(64, u64);
		break;
	    case -1:
	      RESTORE_RAMPS(f, f);
	      break;
	    case -2:
	      RESTORE_RAMPS(d, d);
	      break;
	    default:
	      break; /* impossible */
	    }
	if (crtcs == NULL)
	  libgamma_crtc_destroy(outputs[i].crtc + i);
	output_destroy(outputs + i);
      }
  free(outputs);
  if (crtcs != NULL)
    for (i = 0; i < outputs_n; i++)
      libgamma_crtc_destroy(crtcs + i);
  free(crtcs);
  if (partitions != NULL)
    for (i = 0; i < site.partitions_available; i++)
      libgamma_partition_destroy(partitions + i);
  free(partitions);
  libgamma_site_destroy(&site);
  free(socketpath);
  if (pidpath)
    unlink(pidpath);
  free(pidpath);
}


/**
 * Print usage information and exit
 */
static void usage(void)
{
  printf("Usage: %s [-m method] [-s site] [-p]\n", argv0);
  exit(1);
}


/**
 * Must not be started without stdin, stdout, or stderr (may be /dev/null)
 * 
 * The process closes stdout when the socket has been created
 * 
 * @signal  SIGUSR1  Re-execute to updated process image
 * @signal  SIGTERM  Terminate the process gracefully
 * 
 * @return  0: Successful
 *          1: An error occurred
 *          2: Already running
 */
int main(int argc, char** argv)
{
  int method = -1, rc = 1, preserve = 0, foreground = 0, keep_stderr = 0, r;
  char* sitename = NULL;
  
  ARGBEGIN
    {
    case 's':
      sitename = EARGF(usage());
      break;
    case 'm':
      method = get_method(EARGF(usage()));
      if (method < 0)
	goto fail;
      break;
    case 'p':
      preserve = 1;
      break;
    case 'f':
      foreground = 1;
      break;
    case 'k':
      keep_stderr = 1;
      break;
    default:
      usage();
    }
  ARGEND;
  if (argc > 0)
    usage();
  
  switch ((r = initialise(method, sitename, preserve, foreground, keep_stderr)))
    {
    case 1:
      break;
    case 2:
      goto fail;
    case 3:
      goto fail_libgamma;
    case 4:
      rc = 2;
      goto fail;
    default:
      return -r;
    }
  
  rc = 0;
 done:
  destroy();
  return rc;
 fail:
  if (errno != 0)
    perror(argv0);
  goto done;
 fail_libgamma:
  libgamma_perror(argv0, gerror);
  goto done;
}