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