dss.c

   1 #include <string.h>
   2 #include <stdlib.h>
   3 #include <stdarg.h>
   4 #include <assert.h>
   5 #include <errno.h>
   6 #include <sys/types.h>
   7 #include <signal.h>
   8 #include <ctype.h>
   9 #include <sys/stat.h>
  10 #include <unistd.h>
  11 #include <inttypes.h>
  12 #include <time.h>
  13 #include <sys/wait.h>
  14 #include <fnmatch.h>
  15 #include <limits.h>
  16
  17
  18 #include "gcc-compat.h"
  19 #include "cmdline.h"
  20 #include "log.h"
  21 #include "string.h"
  22 #include "error.h"
  23 #include "fd.h"
  24 #include "exec.h"
  25 #include "daemon.h"
  26 #include "signal.h"
  27 #include "df.h"
  28
  29
  30 struct gengetopt_args_info conf;
  31 char *dss_error_txt = NULL;
  32 static FILE *logfile;
  33 int signal_pipe;
  34
  35 DEFINE_DSS_ERRLIST;
  36
  37
  38 /* a litte cpp magic helps to DRY */
  39 #define COMMANDS \
  40         COMMAND(ls) \
  41         COMMAND(create) \
  42         COMMAND(prune) \
  43         COMMAND(run)
  44 #define COMMAND(x) int com_ ##x(void);
  45 COMMANDS
  46 #undef COMMAND
  47 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
  48 int call_command_handler(void)
  49 {
  50         COMMANDS
  51         DSS_EMERG_LOG("BUG: did not find command handler\n");
  52         exit(EXIT_FAILURE);
  53 }
  54 #undef COMMAND
  55 #undef COMMANDS
  56
  57 /*
  58  * complete, not being deleted: 1204565370-1204565371.Sun_Mar_02_2008_14_33-Sun_Mar_02_2008_14_43
  59  * complete, being deleted: 1204565370-1204565371.being_deleted
  60  * incomplete, not being deleted: 1204565370-incomplete
  61  * incomplete, being deleted: 1204565370-incomplete.being_deleted
  62  */
  63 enum snapshot_status_flags {
  64         SS_COMPLETE = 1,
  65         SS_BEING_DELETED = 2,
  66 };
  67
  68 struct snapshot {
  69         char *name;
  70         int64_t creation_time;
  71         int64_t completion_time;
  72         enum snapshot_status_flags flags;
  73         unsigned interval;
  74 };
  75
  76 __printf_2_3 void dss_log(int ll, const char* fmt,...)
  77 {
  78         va_list argp;
  79         FILE *outfd;
  80         struct tm *tm;
  81         time_t t1;
  82         char str[255] = "";
  83
  84         if (ll < conf.loglevel_arg)
  85                 return;
  86         outfd = logfile? logfile : stderr;
  87         time(&t1);
  88         tm = localtime(&t1);
  89         strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
  90         fprintf(outfd, "%s ", str);
  91         if (conf.loglevel_arg <= INFO)
  92                 fprintf(outfd, "%i: ", ll);
  93         va_start(argp, fmt);
  94         vfprintf(outfd, fmt, argp);
  95         va_end(argp);
  96 }
  97
  98 /**
  99  * Print a message either to stdout or to the log file.
 100  */
 101 __printf_1_2 void dss_msg(const char* fmt,...)
 102 {
 103         FILE *outfd = conf.daemon_given? logfile : stdout;
 104         va_list argp;
 105         va_start(argp, fmt);
 106         vfprintf(outfd, fmt, argp);
 107         va_end(argp);
 108 }
 109
 110 int is_snapshot(const char *dirname, int64_t now, struct snapshot *s)
 111 {
 112         int i, ret;
 113         char *dash, *dot, *tmp;
 114         int64_t num;
 115
 116         assert(dirname);
 117         dash = strchr(dirname, '-');
 118         if (!dash || !dash[1] || dash == dirname)
 119                 return 0;
 120         for (i = 0; dirname[i] != '-'; i++)
 121                 if (!isdigit(dirname[i]))
 122                         return 0;
 123         tmp = dss_strdup(dirname);
 124         tmp[i] = '\0';
 125         ret = dss_atoi64(tmp, &num);
 126         free(tmp);
 127         if (ret < 0) {
 128                 free(dss_error_txt);
 129                 return 0;
 130         }
 131         assert(num >= 0);
 132         if (num > now)
 133                 return 0;
 134         s->creation_time = num;
 135         //DSS_DEBUG_LOG("%s start time: %lli\n", dirname, (long long)s->creation_time);
 136         s->interval = (long long) ((now - s->creation_time)
 137                 / conf.unit_interval_arg / 24 / 3600);
 138         if (!strcmp(dash + 1, "incomplete")) {
 139                 s->completion_time = -1;
 140                 s->flags = 0; /* neither complete, nor being deleted */
 141                 goto success;
 142         }
 143         if (!strcmp(dash + 1, "incomplete.being_deleted")) {
 144                 s->completion_time = -1;
 145                 s->flags = SS_BEING_DELETED; /* mot cpmplete, being deleted */
 146                 goto success;
 147         }
 148         tmp = dash + 1;
 149         dot = strchr(tmp, '.');
 150         if (!dot || !dot[1] || dot == tmp)
 151                 return 0;
 152         for (i = 0; tmp[i] != '.'; i++)
 153                 if (!isdigit(tmp[i]))
 154                         return 0;
 155         tmp = dss_strdup(dash + 1);
 156         tmp[i] = '\0';
 157         ret = dss_atoi64(tmp, &num);
 158         free(tmp);
 159         if (ret < 0) {
 160                 free(dss_error_txt);
 161                 return 0;
 162         }
 163         if (num > now)
 164                 return 0;
 165         s->completion_time = num;
 166         s->flags = SS_COMPLETE;
 167         if (strcmp(dot + 1, "being_deleted"))
 168                 s->flags |= SS_BEING_DELETED;
 169 success:
 170         s->name = dss_strdup(dirname);
 171         return 1;
 172 }
 173
 174 int64_t get_current_time(void)
 175 {
 176         time_t now;
 177         time(&now);
 178         DSS_DEBUG_LOG("now: %lli\n", (long long) now);
 179         return (int64_t)now;
 180 }
 181
 182 char *incomplete_name(int64_t start)
 183 {
 184         return make_message("%lli-incomplete", (long long)start);
 185 }
 186
 187 char *being_deleted_name(struct snapshot *s)
 188 {
 189         if (s->flags & SS_COMPLETE)
 190                 return make_message("%lli-%lli.being_deleted",
 191                         (long long)s->creation_time,
 192                         (long long)s->completion_time);
 193         return make_message("%lli-incomplete.being_deleted",
 194                 (long long)s->creation_time);
 195 }
 196
 197 int complete_name(int64_t start, int64_t end, char **result)
 198 {
 199         struct tm start_tm, end_tm;
 200         time_t *start_seconds = (time_t *) (uint64_t *)&start; /* STFU, gcc */
 201         time_t *end_seconds = (time_t *) (uint64_t *)&end; /* STFU, gcc */
 202         char start_str[200], end_str[200];
 203
 204         if (!localtime_r(start_seconds, &start_tm)) {
 205                 make_err_msg("%lli", (long long)start);
 206                 return -E_LOCALTIME;
 207         }
 208         if (!localtime_r(end_seconds, &end_tm)) {
 209                 make_err_msg("%lli", (long long)end);
 210                 return -E_LOCALTIME;
 211         }
 212         if (!strftime(start_str, sizeof(start_str), "%a_%b_%d_%Y_%H_%M_%S", &start_tm)) {
 213                 make_err_msg("%lli", (long long)start);
 214                 return -E_STRFTIME;
 215         }
 216         if (!strftime(end_str, sizeof(end_str), "%a_%b_%d_%Y_%H_%M_%S", &end_tm)) {
 217                 make_err_msg("%lli", (long long)end);
 218                 return -E_STRFTIME;
 219         }
 220         *result = make_message("%lli-%lli.%s-%s", (long long) start, (long long) end,
 221                 start_str, end_str);
 222         return 1;
 223 }
 224
 225 struct snapshot_list {
 226         int64_t now;
 227         unsigned num_snapshots;
 228         unsigned array_size;
 229         struct snapshot **snapshots;
 230         /**
 231          * Array of size num_intervals + 1
 232          *
 233          * It contains the number of snapshots in each interval. interval_count[num_intervals]
 234          * is the number of snapshots which belong to any interval greater than num_intervals.
 235          */
 236         unsigned *interval_count;
 237 };
 238
 239 #define FOR_EACH_SNAPSHOT(s, i, sl) \
 240         for ((i) = 0; (i) < (sl)->num_snapshots && ((s) = (sl)->snapshots[(i)]); (i)++)
 241
 242
 243
 244 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
 245
 246 static int compare_snapshots(const void *a, const void *b)
 247 {
 248         struct snapshot *s1 = *(struct snapshot **)a;
 249         struct snapshot *s2 = *(struct snapshot **)b;
 250         return NUM_COMPARE(s2->creation_time, s1->creation_time);
 251 }
 252
 253 /** Compute the minimum of \a a and \a b. */
 254 #define DSS_MIN(a,b) ((a) < (b) ? (a) : (b))
 255
 256 int add_snapshot(const char *dirname, void *private)
 257 {
 258         struct snapshot_list *sl = private;
 259         struct snapshot s;
 260         int ret = is_snapshot(dirname, sl->now, &s);
 261
 262         if (!ret)
 263                 return 1;
 264         if (sl->num_snapshots >= sl->array_size) {
 265                 sl->array_size = 2 * sl->array_size + 1;
 266                 sl->snapshots = dss_realloc(sl->snapshots,
 267                         sl->array_size * sizeof(struct snapshot *));
 268         }
 269         sl->snapshots[sl->num_snapshots] = dss_malloc(sizeof(struct snapshot));
 270         *(sl->snapshots[sl->num_snapshots]) = s;
 271         sl->interval_count[DSS_MIN(s.interval, conf.num_intervals_arg)]++;
 272         sl->num_snapshots++;
 273         return 1;
 274 }
 275
 276 void get_snapshot_list(struct snapshot_list *sl)
 277 {
 278         sl->now = get_current_time();
 279         sl->num_snapshots = 0;
 280         sl->array_size = 0;
 281         sl->snapshots = NULL;
 282         sl->interval_count = dss_calloc((conf.num_intervals_arg + 1) * sizeof(unsigned));
 283         for_each_subdir(add_snapshot, sl);
 284         qsort(sl->snapshots, sl->num_snapshots, sizeof(struct snapshot *),
 285                 compare_snapshots);
 286 }
 287
 288 void free_snapshot_list(struct snapshot_list *sl)
 289 {
 290         int i;
 291         struct snapshot *s;
 292
 293         FOR_EACH_SNAPSHOT(s, i, sl) {
 294                 free(s->name);
 295                 free(s);
 296         }
 297         free(sl->interval_count);
 298         free(sl->snapshots);
 299 }
 300
 301 /**
 302  * Print a log message about the exit status of a child.
 303  */
 304 void log_termination_msg(pid_t pid, int status)
 305 {
 306         if (WIFEXITED(status))
 307                 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
 308                         WEXITSTATUS(status));
 309         else if (WIFSIGNALED(status))
 310                 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
 311                         WTERMSIG(status));
 312         else
 313                 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
 314 }
 315
 316 int wait_for_process(pid_t pid, int *status)
 317 {
 318         int ret;
 319
 320         DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
 321         for (;;) {
 322                 pause();
 323                 ret = next_signal();
 324                 if  (ret < 0)
 325                         break;
 326                 if (!ret)
 327                         continue;
 328                 if (ret == SIGCHLD) {
 329                         ret = waitpid(pid, status, 0);
 330                         if (ret >= 0)
 331                                 break;
 332                         if (errno != EINTR) /* error */
 333                                 break;
 334                 }
 335                 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
 336                 kill(pid, SIGTERM);
 337         }
 338         if (ret < 0) {
 339                 ret = -ERRNO_TO_DSS_ERROR(errno);
 340                 make_err_msg("failed to wait for process %d", (int)pid);
 341         } else
 342                 log_termination_msg(pid, *status);
 343         return ret;
 344 }
 345
 346 int remove_snapshot(struct snapshot *s, pid_t *pid)
 347 {
 348         int fds[3] = {0, 0, 0};
 349         char *new_name = being_deleted_name(s);
 350         int ret = dss_rename(s->name, new_name);
 351         char *argv[] = {"rm", "-rf", new_name, NULL};
 352
 353         if (ret < 0)
 354                 goto out;
 355         DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
 356         ret = dss_exec(pid, argv[0], argv, fds);
 357 out:
 358         free(new_name);
 359         return ret;
 360 }
 361
 362 int remove_redundant_snapshot(struct snapshot_list *sl, pid_t *pid)
 363 {
 364         int ret, i, interval;
 365         struct snapshot *s;
 366         unsigned missing = 0;
 367
 368         DSS_INFO_LOG("looking for intervals containing too many snapshots\n");
 369         for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
 370                 unsigned keep = 1<<(conf.num_intervals_arg - interval - 1);
 371                 unsigned num = sl->interval_count[interval];
 372                 struct snapshot *victim = NULL, *prev = NULL;
 373                 int64_t score = LONG_MAX;
 374
 375                 if (keep >= num)
 376                         missing += keep - num;
 377                 DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
 378                         interval, keep, num, missing);
 379                 if (keep + missing >= num)
 380                         continue;
 381                 /* redundant snapshot in this interval, pick snapshot with lowest score */
 382                 FOR_EACH_SNAPSHOT(s, i, sl) {
 383                         int64_t this_score;
 384
 385                         DSS_DEBUG_LOG("checking %s\n", s->name);
 386                         if (s->interval > interval) {
 387                                 prev = s;
 388                                 continue;
 389                         }
 390                         if (s->interval < interval)
 391                                 break;
 392                         if (!victim) {
 393                                 victim = s;
 394                                 prev = s;
 395                                 continue;
 396                         }
 397                         assert(prev);
 398                         /* check if s is a better victim */
 399                         this_score = s->creation_time - prev->creation_time;
 400                         assert(this_score >= 0);
 401                         DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
 402                         if (this_score < score) {
 403                                 score = this_score;
 404                                 victim = s;
 405                         }
 406                         prev = s;
 407                 }
 408                 assert(victim);
 409                 if (conf.dry_run_given) {
 410                         dss_msg("%s would be removed (interval = %i)\n",
 411                                 victim->name, victim->interval);
 412                         continue;
 413                 }
 414                 ret = remove_snapshot(victim, pid);
 415                 return ret < 0? ret : 1;
 416         }
 417         return 0;
 418 }
 419
 420 int remove_old_snapshot(struct snapshot_list *sl, pid_t *pid)
 421 {
 422         int i, ret;
 423         struct snapshot *s;
 424
 425         DSS_INFO_LOG("looking for snapshots belonging to intervals greater than %d\n",
 426                 conf.num_intervals_arg);
 427         FOR_EACH_SNAPSHOT(s, i, sl) {
 428                 if (s->interval <= conf.num_intervals_arg)
 429                         continue;
 430                 if (conf.dry_run_given) {
 431                         dss_msg("%s would be removed (interval = %i)\n",
 432                                 s->name, s->interval);
 433                         continue;
 434                 }
 435                 ret = remove_snapshot(s, pid);
 436                 if (ret < 0)
 437                         return ret;
 438                 return 1;
 439         }
 440         return 0;
 441 }
 442
 443 int wait_for_rm_process(pid_t pid)
 444 {
 445         int status, es, ret = wait_for_process(pid, &status);
 446         if (ret < 0)
 447                 return ret;
 448         if (!WIFEXITED(status)) {
 449                 ret = E_INVOLUNTARY_EXIT;
 450                 make_err_msg("rm process %d died involuntary", (int)pid);
 451                 return ret;
 452         }
 453         es = WEXITSTATUS(status);
 454         if (es) {
 455                 ret = -E_BAD_EXIT_CODE;
 456                 make_err_msg("rm process %d returned %d", (int)pid, es);
 457                 return ret;
 458         }
 459         return 1;
 460 }
 461
 462 int com_run(void)
 463 {
 464         int ret;
 465
 466         if (conf.dry_run_given) {
 467                 make_err_msg("dry_run not supported by this command");
 468                 return -E_SYNTAX;
 469         }
 470         ret = install_sighandler(SIGHUP);
 471         if (ret < 0)
 472                 return ret;
 473         return 42;
 474 }
 475
 476 void log_disk_space(struct disk_space *ds)
 477 {
 478         DSS_INFO_LOG("free: %uM/%uM (%u%%), %u%% inodes unused\n",
 479                 ds->free_mb, ds->total_mb, ds->percent_free,
 480                 ds->percent_free_inodes);
 481 }
 482
 483 int com_prune(void)
 484 {
 485         int ret;
 486         struct snapshot_list sl;
 487         pid_t pid;
 488         struct disk_space ds;
 489
 490         ret = get_disk_space(".", &ds);
 491         if (ret < 0)
 492                 return ret;
 493         log_disk_space(&ds);
 494         for (;;) {
 495                 get_snapshot_list(&sl);
 496                 ret = remove_old_snapshot(&sl, &pid);
 497                 free_snapshot_list(&sl);
 498                 if (ret < 0)
 499                         return ret;
 500                 if (!ret)
 501                         break;
 502                 ret = wait_for_rm_process(pid);
 503                 if (ret < 0)
 504                         goto out;
 505         }
 506         for (;;) {
 507                 get_snapshot_list(&sl);
 508                 ret = remove_redundant_snapshot(&sl, &pid);
 509                 free_snapshot_list(&sl);
 510                 if (ret < 0)
 511                         return ret;
 512                 if (!ret)
 513                         break;
 514                 ret = wait_for_rm_process(pid);
 515                 if (ret < 0)
 516                         goto out;
 517         }
 518         return 1;
 519 out:
 520         return ret;
 521 }
 522
 523 struct newest_snapshot_data {
 524         char * newest_name;
 525         int64_t newest_creation_time;
 526         int64_t now;
 527 };
 528
 529 int get_newest_complete(const char *dirname, void *private)
 530 {
 531         struct newest_snapshot_data *nsd = private;
 532         struct snapshot s;
 533         int ret = is_snapshot(dirname, nsd->now, &s);
 534
 535         if (ret <= 0)
 536                 return 1;
 537         if (s.creation_time < nsd->newest_creation_time)
 538                 return 1;
 539         nsd->newest_creation_time = s.creation_time;
 540         free(nsd->newest_name);
 541         nsd->newest_name = s.name;
 542         return 1;
 543 }
 544
 545 __malloc char *name_of_newest_complete_snapshot(void)
 546 {
 547         struct newest_snapshot_data nsd = {
 548                 .now = get_current_time(),
 549                 .newest_creation_time = -1
 550         };
 551         for_each_subdir(get_newest_complete, &nsd);
 552         return nsd.newest_name;
 553 }
 554
 555 void create_rsync_argv(char ***argv, int64_t *num)
 556 {
 557         char *logname, *newest = name_of_newest_complete_snapshot();
 558         int i = 0, j;
 559
 560         *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
 561         (*argv)[i++] = dss_strdup("rsync");
 562         (*argv)[i++] = dss_strdup("-aq");
 563         (*argv)[i++] = dss_strdup("--delete");
 564         for (j = 0; j < conf.rsync_option_given; j++)
 565                 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
 566         if (newest) {
 567                 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
 568                 (*argv)[i++] = make_message("--link-dest=../%s", newest);
 569                 free(newest);
 570         } else
 571                 DSS_INFO_LOG("no previous snapshot found");
 572         if (conf.exclude_patterns_given) {
 573                 (*argv)[i++] = dss_strdup("--exclude-from");
 574                 (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg);
 575
 576         }
 577         logname = dss_logname();
 578         if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
 579                 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
 580         else
 581                 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
 582                         conf.remote_user_arg : logname,
 583                         conf.remote_host_arg, conf.source_dir_arg);
 584         free(logname);
 585         *num = get_current_time();
 586         (*argv)[i++] = incomplete_name(*num);
 587         (*argv)[i++] = NULL;
 588         for (j = 0; j < i; j++)
 589                 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
 590 }
 591
 592 void free_rsync_argv(char **argv)
 593 {
 594         int i;
 595         for (i = 0; argv[i]; i++)
 596                 free(argv[i]);
 597         free(argv);
 598 }
 599
 600 int create_snapshot(char **argv, pid_t *pid)
 601 {
 602         int fds[3] = {0, 0, 0};
 603
 604         return dss_exec(pid, argv[0], argv, fds);
 605 }
 606
 607 int rename_incomplete_snapshot(int64_t start)
 608 {
 609         char *old_name, *new_name;
 610         int ret;
 611
 612         ret = complete_name(start, get_current_time(), &new_name);
 613         if (ret < 0)
 614                 return ret;
 615         old_name = incomplete_name(start);
 616         ret = dss_rename(old_name, new_name);
 617         if (ret >= 0)
 618                 DSS_NOTICE_LOG("%s -> %s\n", old_name, new_name);
 619         free(old_name);
 620         free(new_name);
 621         return ret;
 622 }
 623
 624 int com_create(void)
 625 {
 626         int ret, status, es;
 627         char **rsync_argv;
 628         int64_t snapshot_num;
 629         pid_t pid;
 630
 631         create_rsync_argv(&rsync_argv, &snapshot_num);
 632         if (conf.dry_run_given) {
 633                 int i;
 634                 char *msg = NULL;
 635                 for (i = 0; rsync_argv[i]; i++) {
 636                         char *tmp = msg;
 637                         msg = make_message("%s%s%s", tmp? tmp : "",
 638                                 tmp? " " : "", rsync_argv[i]);
 639                         free(tmp);
 640                 }
 641                 dss_msg("%s\n", msg);
 642                 free(msg);
 643                 return 1;
 644         }
 645         DSS_NOTICE_LOG("creating snapshot %lli\n", (long long)snapshot_num);
 646         ret = create_snapshot(rsync_argv, &pid);
 647         if (ret < 0)
 648                 goto out;
 649         ret = wait_for_process(pid, &status);
 650         if (ret < 0)
 651                 goto out;
 652         if (!WIFEXITED(status)) {
 653                 ret = E_INVOLUNTARY_EXIT;
 654                 make_err_msg("rsync process %d died involuntary", (int)pid);
 655                 goto out;
 656         }
 657         es = WEXITSTATUS(status);
 658         if (es != 0 && es != 23 && es != 24) {
 659                 ret = -E_BAD_EXIT_CODE;
 660                 make_err_msg("rsync process %d returned %d", (int)pid, es);
 661                 goto out;
 662         }
 663         ret = rename_incomplete_snapshot(snapshot_num);
 664 out:
 665         free_rsync_argv(rsync_argv);
 666         return ret;
 667 }
 668
 669 int com_ls(void)
 670 {
 671         int i;
 672         struct snapshot_list sl;
 673         struct snapshot *s;
 674         get_snapshot_list(&sl);
 675         FOR_EACH_SNAPSHOT(s, i, &sl)
 676                 dss_msg("%u\t%s\n", s->interval, s->name);
 677         free_snapshot_list(&sl);
 678         return 1;
 679 }
 680
 681 /* TODO: Unlink pid file */
 682 __noreturn void clean_exit(int status)
 683 {
 684         //kill(0, SIGTERM);
 685         free(dss_error_txt);
 686         exit(status);
 687 }
 688
 689 int read_config_file(void)
 690 {
 691         int ret;
 692         char *config_file;
 693         struct stat statbuf;
 694
 695         if (conf.config_file_given)
 696                 config_file = dss_strdup(conf.config_file_arg);
 697         else {
 698                 char *home = get_homedir();
 699                 config_file = make_message("%s/.dssrc", home);
 700                 free(home);
 701         }
 702         ret = stat(config_file, &statbuf);
 703         if (ret && conf.config_file_given) {
 704                 ret = -ERRNO_TO_DSS_ERROR(errno);
 705                 make_err_msg("failed to stat config file %s", config_file);
 706                 goto out;
 707         }
 708         if (!ret) {
 709                 struct cmdline_parser_params params = {
 710                         .override = 0,
 711                         .initialize = 0,
 712                         .check_required = 0,
 713                         .check_ambiguity = 0
 714                 };
 715                 cmdline_parser_config_file(config_file, &conf, &params);
 716         }
 717         if (!conf.source_dir_given || !conf.dest_dir_given) {
 718                 ret = -E_SYNTAX;
 719                 make_err_msg("you need to specify both source_dir and dest_dir");
 720                 goto out;
 721         }
 722         ret = 1;
 723 out:
 724         free(config_file);
 725         return ret;
 726 }
 727
 728 int check_config(void)
 729 {
 730         if (conf.unit_interval_arg <= 0) {
 731                 make_err_msg("bad unit interval: %i", conf.unit_interval_arg);
 732                 return -E_INVALID_NUMBER;
 733         }
 734         DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
 735         if (conf.num_intervals_arg <= 0) {
 736                 make_err_msg("bad number of intervals  %i", conf.num_intervals_arg);
 737                 return -E_INVALID_NUMBER;
 738         }
 739         DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
 740         return 1;
 741 }
 742
 743 static void setup_signal_handling(void)
 744 {
 745         int ret;
 746
 747         DSS_NOTICE_LOG("setting up signal handlers\n");
 748         signal_pipe = signal_init(); /* always successful */
 749         ret = install_sighandler(SIGINT);
 750         if (ret < 0)
 751                 goto err;
 752         ret = install_sighandler(SIGTERM);
 753         if (ret < 0)
 754                 goto err;
 755         ret = install_sighandler(SIGCHLD);
 756         if (ret < 0)
 757                 goto err;
 758         return;
 759 err:
 760         DSS_EMERG_LOG("could not install signal handlers\n");
 761         exit(EXIT_FAILURE);
 762 }
 763
 764
 765 int main(int argc, char **argv)
 766 {
 767         int ret;
 768
 769         cmdline_parser(argc, argv, &conf); /* aborts on errors */
 770         if (conf.inputs_num) {
 771                 ret = -E_SYNTAX;
 772                 make_err_msg("additional non-options given");
 773                 goto out;
 774         }
 775         ret = read_config_file();
 776         if (ret < 0)
 777                 goto out;
 778         ret = check_config();
 779         if (ret < 0)
 780                 goto out;
 781         if (conf.logfile_given) {
 782                 logfile = open_log(conf.logfile_arg);
 783                 log_welcome(conf.loglevel_arg);
 784         }
 785         ret = dss_chdir(conf.dest_dir_arg);
 786         if (ret < 0)
 787                 goto out;
 788         if (conf.daemon_given)
 789                 daemon_init();
 790         setup_signal_handling();
 791         ret = call_command_handler();
 792 out:
 793         if (ret < 0)
 794                 log_err_msg(EMERG, -ret);
 795         clean_exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
 796 }