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