dss.c

   1 /*
   2  * Copyright (C) 2008-2011 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6 #include <string.h>
   7 #include <stdlib.h>
   8 #include <stdarg.h>
   9 #include <assert.h>
  10 #include <errno.h>
  11 #include <sys/types.h>
  12 #include <signal.h>
  13 #include <ctype.h>
  14 #include <sys/stat.h>
  15 #include <unistd.h>
  16 #include <inttypes.h>
  17 #include <sys/time.h>
  18 #include <time.h>
  19 #include <sys/wait.h>
  20 #include <fnmatch.h>
  21 #include <limits.h>
  22
  23
  24 #include "gcc-compat.h"
  25 #include "cmdline.h"
  26 #include "log.h"
  27 #include "string.h"
  28 #include "error.h"
  29 #include "fd.h"
  30 #include "exec.h"
  31 #include "daemon.h"
  32 #include "signal.h"
  33 #include "df.h"
  34 #include "time.h"
  35 #include "snap.h"
  36
  37 /** Command line and config file options. */
  38 static struct gengetopt_args_info conf;
  39 /** Non-NULL if we log to a file. */
  40 static FILE *logfile;
  41 /** The read end of the signal pipe */
  42 static int signal_pipe;
  43 /** Process id of current pre-create-hook/rsync/post-create-hook process. */
  44 static pid_t create_pid;
  45 /** Whether the pre-create-hook/rsync/post-create-hook is currently stopped. */
  46 static int create_process_stopped;
  47 /** Process id of current pre-remove/rm/post-remove process. */
  48 static pid_t remove_pid;
  49 /** When the next snapshot is due. */
  50 static int64_t next_snapshot_time;
  51 /** When to try to remove something. */
  52 static struct timeval next_removal_check;
  53 /** Creation time of the snapshot currently being created. */
  54 static int64_t current_snapshot_creation_time;
  55 /** The snapshot currently being removed. */
  56 struct snapshot *snapshot_currently_being_removed;
  57 /** Needed by the post-create hook. */
  58 static char *path_to_last_complete_snapshot;
  59 static char *name_of_reference_snapshot;
  60 /** \sa \ref snap.h for details. */
  61 enum hook_status snapshot_creation_status;
  62 /** \sa \ref snap.h for details. */
  63 enum hook_status snapshot_removal_status;
  64
  65
  66 DEFINE_DSS_ERRLIST;
  67 static const char *hook_status_description[] = {HOOK_STATUS_ARRAY};
  68
  69 /* may be called with ds == NULL. */
  70 static int disk_space_low(struct disk_space *ds)
  71 {
  72         struct disk_space ds_struct;
  73
  74         if (!ds) {
  75                 int ret = get_disk_space(".", &ds_struct);
  76                 if (ret < 0)
  77                         return ret;
  78                 ds = &ds_struct;
  79         }
  80         if (conf.min_free_mb_arg)
  81                 if (ds->free_mb < conf.min_free_mb_arg)
  82                         return 1;
  83         if (conf.min_free_percent_arg)
  84                 if (ds->percent_free < conf.min_free_percent_arg)
  85                         return 1;
  86         if (conf.min_free_percent_inodes_arg)
  87                 if (ds->percent_free_inodes < conf.min_free_percent_inodes_arg)
  88                         return 1;
  89         return 0;
  90 }
  91
  92 static void dump_dss_config(const char *msg)
  93 {
  94         const char dash[] = "-----------------------------";
  95         int ret;
  96         FILE *log = logfile? logfile : stderr;
  97         struct disk_space ds;
  98         int64_t now = get_current_time();
  99
 100         if (conf.loglevel_arg > INFO)
 101                 return;
 102
 103         fprintf(log, "%s <%s config> %s\n", dash, msg, dash);
 104         fprintf(log, "\n*** disk space ***\n\n");
 105         ret = get_disk_space(".", &ds);
 106         if (ret >= 0) {
 107                 DSS_INFO_LOG("disk space low: %s\n", disk_space_low(&ds)?
 108                         "yes" : "no");
 109                 log_disk_space(&ds);
 110         } else
 111                 DSS_ERROR_LOG("can not get free disk space: %s\n",
 112                         dss_strerror(-ret));
 113
 114         /* we continue on errors from get_disk_space */
 115
 116         fprintf(log, "\n*** command line and config file options ***\n\n");
 117         cmdline_parser_dump(log, &conf);
 118         fprintf(log, "\n*** internal state ***\n\n");
 119         fprintf(log,
 120                 "pid: %d\n"
 121                 "logile: %s\n"
 122                 "snapshot_currently_being_removed: %s\n"
 123                 "path_to_last_complete_snapshot: %s\n"
 124                 "reference_snapshot: %s\n"
 125                 "snapshot_creation_status: %s\n"
 126                 "snapshot_removal_status: %s\n"
 127                 ,
 128                 (int) getpid(),
 129                 logfile? conf.logfile_arg : "stderr",
 130                 snapshot_currently_being_removed?
 131                         snapshot_currently_being_removed->name : "(none)",
 132                 path_to_last_complete_snapshot?
 133                         path_to_last_complete_snapshot : "(none)",
 134                 name_of_reference_snapshot?
 135                         name_of_reference_snapshot : "(none)",
 136                 hook_status_description[snapshot_creation_status],
 137                 hook_status_description[snapshot_removal_status]
 138         );
 139         if (create_pid != 0)
 140                 fprintf(log,
 141                         "create_pid: %" PRId32 "\n"
 142                         "create process is %sstopped\n"
 143                         ,
 144                         create_pid,
 145                         create_process_stopped? "" : "not "
 146                 );
 147         if (remove_pid != 0)
 148                 fprintf(log, "remove_pid: %" PRId32 "\n", remove_pid);
 149         if (next_snapshot_time != 0)
 150                 fprintf(log, "next snapshot due in %" PRId64 " seconds\n",
 151                         next_snapshot_time - now);
 152         if (current_snapshot_creation_time != 0)
 153                 fprintf(log, "current_snapshot_creation_time: %"
 154                         PRId64 " (%" PRId64 " seconds ago)\n",
 155                         current_snapshot_creation_time,
 156                         now - current_snapshot_creation_time
 157                 );
 158         if (next_removal_check.tv_sec != 0) {
 159                 fprintf(log, "next removal check: %llu (%llu seconds ago)\n",
 160                         (long long unsigned)next_removal_check.tv_sec,
 161                         now - (long long unsigned)next_removal_check.tv_sec
 162                 );
 163
 164         }
 165         fprintf(log, "%s </%s config> %s\n", dash, msg, dash);
 166 }
 167
 168 /* a litte cpp magic helps to DRY */
 169 #define COMMANDS \
 170         COMMAND(ls) \
 171         COMMAND(create) \
 172         COMMAND(prune) \
 173         COMMAND(run)
 174 #define COMMAND(x) static int com_ ##x(void);
 175 COMMANDS
 176 #undef COMMAND
 177 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
 178 static int call_command_handler(void)
 179 {
 180         COMMANDS
 181         DSS_EMERG_LOG("BUG: did not find command handler\n");
 182         return -E_BUG;
 183 }
 184 #undef COMMAND
 185 #undef COMMANDS
 186
 187 /**
 188  * The log function of dss.
 189  *
 190  * \param ll Loglevel.
 191  * \param fml Usual format string.
 192  *
 193  * All DSS_XXX_LOG() macros use this function.
 194  */
 195 __printf_2_3 void dss_log(int ll, const char* fmt,...)
 196 {
 197         va_list argp;
 198         FILE *outfd;
 199         struct tm *tm;
 200         time_t t1;
 201         char str[255] = "";
 202
 203         if (ll < conf.loglevel_arg)
 204                 return;
 205         outfd = logfile? logfile : stderr;
 206         time(&t1);
 207         tm = localtime(&t1);
 208         strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
 209         fprintf(outfd, "%s ", str);
 210         if (conf.loglevel_arg <= INFO)
 211                 fprintf(outfd, "%i: ", ll);
 212         va_start(argp, fmt);
 213         vfprintf(outfd, fmt, argp);
 214         va_end(argp);
 215 }
 216
 217 /**
 218  * Print a message either to stdout or to the log file.
 219  */
 220 static __printf_1_2 void dss_msg(const char* fmt,...)
 221 {
 222         FILE *outfd = conf.daemon_given? logfile : stdout;
 223         va_list argp;
 224         va_start(argp, fmt);
 225         vfprintf(outfd, fmt, argp);
 226         va_end(argp);
 227 }
 228
 229 static void dss_get_snapshot_list(struct snapshot_list *sl)
 230 {
 231         get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
 232 }
 233
 234 static int64_t compute_next_snapshot_time(void)
 235 {
 236         int64_t x = 0, now = get_current_time(), unit_interval
 237                 = 24 * 3600 * conf.unit_interval_arg, ret;
 238         unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
 239                 num_complete_snapshots = 0;
 240         int i;
 241         struct snapshot *s = NULL;
 242         struct snapshot_list sl;
 243
 244         dss_get_snapshot_list(&sl);
 245         FOR_EACH_SNAPSHOT(s, i, &sl) {
 246                 if (!(s->flags & SS_COMPLETE))
 247                         continue;
 248                 num_complete_snapshots++;
 249                 x += s->completion_time - s->creation_time;
 250         }
 251         assert(x >= 0);
 252
 253         ret = now;
 254         if (num_complete_snapshots == 0)
 255                 goto out;
 256         x /= num_complete_snapshots; /* avg time to create one snapshot */
 257         if (unit_interval < x * wanted) /* oops, no sleep at all */
 258                 goto out;
 259         ret = s->completion_time + unit_interval / wanted - x;
 260 out:
 261         free_snapshot_list(&sl);
 262         return ret;
 263 }
 264
 265 static inline void invalidate_next_snapshot_time(void)
 266 {
 267         next_snapshot_time = 0;
 268 }
 269
 270 static inline int next_snapshot_time_is_valid(void)
 271 {
 272         return next_snapshot_time != 0;
 273 }
 274
 275 static int next_snapshot_is_due(void)
 276 {
 277         int64_t now = get_current_time();
 278
 279         if (!next_snapshot_time_is_valid())
 280                 next_snapshot_time = compute_next_snapshot_time();
 281         if (next_snapshot_time <= now) {
 282                 DSS_DEBUG_LOG("next snapshot: now\n");
 283                 return 1;
 284         }
 285         DSS_DEBUG_LOG("next snapshot due in %" PRId64 " seconds\n",
 286                 next_snapshot_time - now);
 287         return 0;
 288 }
 289
 290 static void pre_create_hook(void)
 291 {
 292         assert(snapshot_creation_status == HS_READY);
 293         /* make sure that the next snapshot time will be recomputed */
 294         invalidate_next_snapshot_time();
 295         DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg);
 296         dss_exec_cmdline_pid(&create_pid, conf.pre_create_hook_arg);
 297         snapshot_creation_status = HS_PRE_RUNNING;
 298 }
 299
 300 static void pre_remove_hook(struct snapshot *s, const char *why)
 301 {
 302         char *cmd;
 303
 304         if (!s)
 305                 return;
 306         DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name);
 307         assert(snapshot_removal_status == HS_READY);
 308         assert(remove_pid == 0);
 309         assert(!snapshot_currently_being_removed);
 310
 311         snapshot_currently_being_removed = dss_malloc(sizeof(struct snapshot));
 312         *snapshot_currently_being_removed = *s;
 313         snapshot_currently_being_removed->name = dss_strdup(s->name);
 314
 315         cmd = make_message("%s %s/%s", conf.pre_remove_hook_arg,
 316                 conf.dest_dir_arg, s->name);
 317         DSS_DEBUG_LOG("executing %s\n", cmd);
 318         dss_exec_cmdline_pid(&remove_pid, cmd);
 319         free(cmd);
 320         snapshot_removal_status = HS_PRE_RUNNING;
 321 }
 322
 323 static int exec_rm(void)
 324 {
 325         struct snapshot *s = snapshot_currently_being_removed;
 326         char *new_name = being_deleted_name(s);
 327         char *argv[] = {"rm", "-rf", new_name, NULL};
 328         int ret;
 329
 330         assert(snapshot_removal_status == HS_PRE_SUCCESS);
 331         assert(remove_pid == 0);
 332
 333         DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
 334         ret = dss_rename(s->name, new_name);
 335         if (ret < 0)
 336                 goto out;
 337         dss_exec(&remove_pid, argv[0], argv);
 338         snapshot_removal_status = HS_RUNNING;
 339 out:
 340         free(new_name);
 341         return ret;
 342 }
 343
 344 static int snapshot_is_being_created(struct snapshot *s)
 345 {
 346         return s->creation_time == current_snapshot_creation_time;
 347 }
 348
 349 static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl)
 350 {
 351         struct snapshot *s;
 352         int i;
 353
 354         DSS_DEBUG_LOG("looking for orphaned snapshots\n");
 355         FOR_EACH_SNAPSHOT(s, i, sl) {
 356                 if (snapshot_is_being_created(s))
 357                         continue;
 358                 /*
 359                  * We know that no rm is currently running, so if s is marked
 360                  * as being deleted, a previously started rm must have failed.
 361                  */
 362                 if (s->flags & SS_BEING_DELETED)
 363                         return s;
 364
 365                 if (s->flags & SS_COMPLETE) /* good snapshot */
 366                         continue;
 367                 /*
 368                  * This snapshot is incomplete and it is not the snapshot
 369                  * currently being created. However, we must not remove it if
 370                  * rsync is about to be restarted. As only the newest snapshot
 371                  * can be restarted, this snapshot is orphaned if it is not the
 372                  * newest snapshot or if we are not about to restart rsync.
 373                  */
 374                 if (get_newest_snapshot(sl) != s)
 375                         return s;
 376                 if (snapshot_creation_status != HS_NEEDS_RESTART)
 377                         return s;
 378         }
 379         /* no orphaned snapshots */
 380         return NULL;
 381 }
 382
 383 static int is_reference_snapshot(struct snapshot *s)
 384 {
 385         if (!name_of_reference_snapshot)
 386                 return 0;
 387         return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
 388 }
 389
 390 /*
 391  * return: 0: no redundant snapshots, 1: rm process started, negative: error
 392  */
 393 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
 394 {
 395         int i, interval;
 396         struct snapshot *s;
 397         unsigned missing = 0;
 398
 399         DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
 400         for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
 401                 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
 402                 unsigned num = sl->interval_count[interval];
 403                 struct snapshot *victim = NULL, *prev = NULL;
 404                 int64_t score = LONG_MAX;
 405
 406                 if (keep >= num)
 407                         missing += keep - num;
 408 //              DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
 409 //                      interval, keep, num, missing);
 410                 if (keep + missing >= num)
 411                         continue;
 412                 /* redundant snapshot in this interval, pick snapshot with lowest score */
 413                 FOR_EACH_SNAPSHOT(s, i, sl) {
 414                         int64_t this_score;
 415
 416                         if (snapshot_is_being_created(s))
 417                                 continue;
 418                         if (is_reference_snapshot(s))
 419                                 continue;
 420                         //DSS_DEBUG_LOG("checking %s\n", s->name);
 421                         if (s->interval > interval) {
 422                                 prev = s;
 423                                 continue;
 424                         }
 425                         if (s->interval < interval)
 426                                 break;
 427                         if (!victim) {
 428                                 victim = s;
 429                                 prev = s;
 430                                 continue;
 431                         }
 432                         assert(prev);
 433                         /* check if s is a better victim */
 434                         this_score = s->creation_time - prev->creation_time;
 435                         assert(this_score >= 0);
 436                         //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
 437                         if (this_score < score) {
 438                                 score = this_score;
 439                                 victim = s;
 440                         }
 441                         prev = s;
 442                 }
 443                 assert(victim);
 444                 return victim;
 445         }
 446         return NULL;
 447 }
 448
 449 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
 450 {
 451         int i;
 452         struct snapshot *s;
 453
 454         DSS_DEBUG_LOG("looking for snapshots belonging to intervals >= %d\n",
 455                 conf.num_intervals_arg);
 456         FOR_EACH_SNAPSHOT(s, i, sl) {
 457                 if (snapshot_is_being_created(s))
 458                         continue;
 459                 if (is_reference_snapshot(s))
 460                         continue;
 461                 if (s->interval < conf.num_intervals_arg)
 462                         continue;
 463                 return s;
 464         }
 465         return NULL;
 466 }
 467
 468 struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
 469 {
 470         int i;
 471         struct snapshot *s;
 472         FOR_EACH_SNAPSHOT(s, i, sl) {
 473                 if (snapshot_is_being_created(s))
 474                         continue;
 475                 if (is_reference_snapshot(s))
 476                         continue;
 477                 DSS_INFO_LOG("oldest removable snapshot: %s\n", s->name);
 478                 return s;
 479         }
 480         return NULL;
 481 }
 482
 483 static int rename_incomplete_snapshot(int64_t start)
 484 {
 485         char *old_name;
 486         int ret;
 487
 488         free(path_to_last_complete_snapshot);
 489         ret = complete_name(start, get_current_time(),
 490                 &path_to_last_complete_snapshot);
 491         if (ret < 0)
 492                 return ret;
 493         old_name = incomplete_name(start);
 494         ret = dss_rename(old_name, path_to_last_complete_snapshot);
 495         if (ret >= 0)
 496                 DSS_NOTICE_LOG("%s -> %s\n", old_name,
 497                         path_to_last_complete_snapshot);
 498         free(old_name);
 499         return ret;
 500 }
 501
 502 static int try_to_free_disk_space(void)
 503 {
 504         int ret;
 505         struct snapshot_list sl;
 506         struct snapshot *victim;
 507         struct timeval now;
 508         const char *why;
 509         int low_disk_space;
 510
 511         ret = disk_space_low(NULL);
 512         if (ret < 0)
 513                 return ret;
 514         low_disk_space = ret;
 515         gettimeofday(&now, NULL);
 516         if (tv_diff(&next_removal_check, &now, NULL) > 0)
 517                 return 0;
 518         if (!low_disk_space) {
 519                 if (conf.keep_redundant_given)
 520                         return 0;
 521                 if (snapshot_creation_status != HS_READY)
 522                         return 0;
 523                 if (next_snapshot_is_due())
 524                         return 0;
 525         }
 526         dss_get_snapshot_list(&sl);
 527         ret = 0;
 528         if (!low_disk_space && sl.num_snapshots <= 1)
 529                 goto out;
 530         why = "outdated";
 531         victim = find_outdated_snapshot(&sl);
 532         if (victim)
 533                 goto remove;
 534         why = "redundant";
 535         victim = find_redundant_snapshot(&sl);
 536         if (victim)
 537                 goto remove;
 538         /* try harder only if disk space is low */
 539         if (!low_disk_space)
 540                 goto out;
 541         why = "orphaned";
 542         victim = find_orphaned_snapshot(&sl);
 543         if (victim)
 544                 goto remove;
 545         DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
 546         victim = find_oldest_removable_snapshot(&sl);
 547         if (victim)
 548                 goto remove;
 549         DSS_CRIT_LOG("uhuhu: disk space low and nothing to remove\n");
 550         ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
 551         goto out;
 552 remove:
 553         pre_remove_hook(victim, why);
 554 out:
 555         free_snapshot_list(&sl);
 556         return ret;
 557 }
 558
 559 static void post_create_hook(void)
 560 {
 561         char *cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
 562                 conf.dest_dir_arg, path_to_last_complete_snapshot);
 563         DSS_NOTICE_LOG("executing %s\n", cmd);
 564         dss_exec_cmdline_pid(&create_pid, cmd);
 565         free(cmd);
 566         snapshot_creation_status = HS_POST_RUNNING;
 567 }
 568
 569 static void post_remove_hook(void)
 570 {
 571         char *cmd;
 572         struct snapshot *s = snapshot_currently_being_removed;
 573
 574         assert(s);
 575
 576         cmd = make_message("%s %s/%s", conf.post_remove_hook_arg,
 577                 conf.dest_dir_arg, s->name);
 578         DSS_NOTICE_LOG("executing %s\n", cmd);
 579         dss_exec_cmdline_pid(&remove_pid, cmd);
 580         free(cmd);
 581         snapshot_removal_status = HS_POST_RUNNING;
 582 }
 583
 584 static void dss_kill(pid_t pid, int sig, const char *msg)
 585 {
 586         const char *signame, *process_name;
 587
 588         if (pid == 0)
 589                 return;
 590         switch (sig) {
 591         case SIGTERM: signame = "TERM"; break;
 592         case SIGSTOP: signame = "STOP"; break;
 593         case SIGCONT: signame = "CONT"; break;
 594         default: signame = "????";
 595         }
 596
 597         if (pid == create_pid)
 598                 process_name = "create";
 599         else if (pid == remove_pid)
 600                 process_name = "remove";
 601         else process_name = "??????";
 602
 603         if (msg)
 604                 DSS_INFO_LOG("%s\n", msg);
 605         DSS_DEBUG_LOG("sending signal %d (%s) to pid %d (%s process)\n",
 606                 sig, signame, (int)pid, process_name);
 607         if (kill(pid, sig) >= 0)
 608                 return;
 609         DSS_INFO_LOG("failed to send signal %d (%s) to pid %d (%s process)\n",
 610                 sig, signame, (int)pid, process_name);
 611 }
 612
 613 static void stop_create_process(void)
 614 {
 615         if (create_process_stopped)
 616                 return;
 617         dss_kill(create_pid, SIGSTOP, "suspending create process");
 618         create_process_stopped = 1;
 619 }
 620
 621 static void restart_create_process(void)
 622 {
 623         if (!create_process_stopped)
 624                 return;
 625         dss_kill(create_pid, SIGCONT, "resuming create process");
 626         create_process_stopped = 0;
 627 }
 628
 629 /**
 630  * Print a log message about the exit status of a child.
 631  */
 632 static void log_termination_msg(pid_t pid, int status)
 633 {
 634         if (WIFEXITED(status))
 635                 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
 636                         WEXITSTATUS(status));
 637         else if (WIFSIGNALED(status))
 638                 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
 639                         WTERMSIG(status));
 640         else
 641                 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
 642 }
 643
 644 static int wait_for_process(pid_t pid, int *status)
 645 {
 646         int ret;
 647
 648         DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
 649         for (;;) {
 650                 fd_set rfds;
 651
 652                 FD_ZERO(&rfds);
 653                 FD_SET(signal_pipe, &rfds);
 654                 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
 655                 if (ret < 0)
 656                         break;
 657                 ret = next_signal();
 658                 if (!ret)
 659                         continue;
 660                 if (ret == SIGCHLD) {
 661                         ret = waitpid(pid, status, 0);
 662                         if (ret >= 0)
 663                                 break;
 664                         if (errno != EINTR) { /* error */
 665                                 ret = -ERRNO_TO_DSS_ERROR(errno);
 666                                 break;
 667                         }
 668                 }
 669                 /* SIGINT or SIGTERM */
 670                 dss_kill(pid, SIGTERM, "killing child process");
 671         }
 672         if (ret < 0)
 673                 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
 674         else
 675                 log_termination_msg(pid, *status);
 676         return ret;
 677 }
 678
 679 static void handle_pre_remove_exit(int status)
 680 {
 681         if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 682                 snapshot_removal_status = HS_READY;
 683                 gettimeofday(&next_removal_check, NULL);
 684                 next_removal_check.tv_sec += 60;
 685                 return;
 686         }
 687         snapshot_removal_status = HS_PRE_SUCCESS;
 688 }
 689
 690 static int handle_rm_exit(int status)
 691 {
 692         if (!WIFEXITED(status)) {
 693                 snapshot_removal_status = HS_READY;
 694                 return -E_INVOLUNTARY_EXIT;
 695         }
 696         if (WEXITSTATUS(status)) {
 697                 snapshot_removal_status = HS_READY;
 698                 return -E_BAD_EXIT_CODE;
 699         }
 700         snapshot_removal_status = HS_SUCCESS;
 701         return 1;
 702 }
 703
 704 static void handle_post_remove_exit(void)
 705 {
 706         snapshot_removal_status = HS_READY;
 707 }
 708
 709 static int handle_remove_exit(int status)
 710 {
 711         int ret;
 712         struct snapshot *s = snapshot_currently_being_removed;
 713
 714         assert(s);
 715         switch (snapshot_removal_status) {
 716         case HS_PRE_RUNNING:
 717                 handle_pre_remove_exit(status);
 718                 ret = 1;
 719                 break;
 720         case HS_RUNNING:
 721                 ret = handle_rm_exit(status);
 722                 break;
 723         case HS_POST_RUNNING:
 724                 handle_post_remove_exit();
 725                 ret = 1;
 726                 break;
 727         default:
 728                 ret = -E_BUG;
 729         }
 730         if (snapshot_removal_status == HS_READY) {
 731                 free(s->name);
 732                 free(s);
 733                 snapshot_currently_being_removed = NULL;
 734         }
 735         remove_pid = 0;
 736         return ret;
 737 }
 738
 739 static int wait_for_remove_process(void)
 740 {
 741         int status, ret;
 742
 743         assert(remove_pid);
 744         assert(
 745                 snapshot_removal_status == HS_PRE_RUNNING ||
 746                 snapshot_removal_status == HS_RUNNING ||
 747                 snapshot_removal_status == HS_POST_RUNNING
 748         );
 749         ret = wait_for_process(remove_pid, &status);
 750         if (ret < 0)
 751                 return ret;
 752         return handle_remove_exit(status);
 753 }
 754
 755 static int handle_rsync_exit(int status)
 756 {
 757         int es, ret;
 758
 759         if (!WIFEXITED(status)) {
 760                 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)create_pid);
 761                 ret = -E_INVOLUNTARY_EXIT;
 762                 snapshot_creation_status = HS_READY;
 763                 goto out;
 764         }
 765         es = WEXITSTATUS(status);
 766         /*
 767          * Restart rsync on non-fatal errors:
 768          * 12: Error in rsync protocol data stream
 769          * 13: Errors with program diagnostics
 770          */
 771         if (es == 12 || es == 13) {
 772                 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
 773                         (int)create_pid, es);
 774                 snapshot_creation_status = HS_NEEDS_RESTART;
 775                 next_snapshot_time = get_current_time() + 60;
 776                 ret = 1;
 777                 goto out;
 778         }
 779         if (es != 0 && es != 23 && es != 24) {
 780                 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)create_pid, es);
 781                 ret = -E_BAD_EXIT_CODE;
 782                 snapshot_creation_status = HS_READY;
 783                 goto out;
 784         }
 785         ret = rename_incomplete_snapshot(current_snapshot_creation_time);
 786         if (ret < 0)
 787                 goto out;
 788         snapshot_creation_status = HS_SUCCESS;
 789         free(name_of_reference_snapshot);
 790         name_of_reference_snapshot = NULL;
 791 out:
 792         create_process_stopped = 0;
 793         return ret;
 794 }
 795
 796 static int handle_pre_create_hook_exit(int status)
 797 {
 798         int es, ret;
 799         static int warn_count;
 800
 801         if (!WIFEXITED(status)) {
 802                 snapshot_creation_status = HS_READY;
 803                 ret = -E_INVOLUNTARY_EXIT;
 804                 goto out;
 805         }
 806         es = WEXITSTATUS(status);
 807         if (es) {
 808                 if (!warn_count--) {
 809                         DSS_NOTICE_LOG("pre_create_hook %s returned %d\n",
 810                                 conf.pre_create_hook_arg, es);
 811                         DSS_NOTICE_LOG("deferring snapshot creation...\n");
 812                         warn_count = 60; /* warn only once per hour */
 813                 }
 814                 next_snapshot_time = get_current_time() + 60;
 815                 snapshot_creation_status = HS_READY;
 816                 ret = 0;
 817                 goto out;
 818         }
 819         warn_count = 0;
 820         snapshot_creation_status = HS_PRE_SUCCESS;
 821         ret = 1;
 822 out:
 823         return ret;
 824 }
 825
 826 static int handle_sigchld(void)
 827 {
 828         pid_t pid;
 829         int status, ret = reap_child(&pid, &status);
 830
 831         if (ret <= 0)
 832                 return ret;
 833
 834         if (pid == create_pid) {
 835                 switch (snapshot_creation_status) {
 836                 case HS_PRE_RUNNING:
 837                         ret = handle_pre_create_hook_exit(status);
 838                         break;
 839                 case HS_RUNNING:
 840                         ret = handle_rsync_exit(status);
 841                         break;
 842                 case HS_POST_RUNNING:
 843                         snapshot_creation_status = HS_READY;
 844                         ret = 1;
 845                         break;
 846                 default:
 847                         DSS_EMERG_LOG("BUG: create can't die in status %d\n",
 848                                 snapshot_creation_status);
 849                         return -E_BUG;
 850                 }
 851                 create_pid = 0;
 852                 return ret;
 853         }
 854         if (pid == remove_pid) {
 855                 ret = handle_remove_exit(status);
 856                 if (ret < 0)
 857                         return ret;
 858                 return ret;
 859         }
 860         DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
 861         return -E_BUG;
 862 }
 863
 864 static int check_config(void)
 865 {
 866         if (conf.unit_interval_arg <= 0) {
 867                 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
 868                 return -E_INVALID_NUMBER;
 869         }
 870         DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
 871         if (conf.num_intervals_arg <= 0) {
 872                 DSS_ERROR_LOG("bad number of intervals  %i\n", conf.num_intervals_arg);
 873                 return -E_INVALID_NUMBER;
 874         }
 875         DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
 876         return 1;
 877 }
 878
 879 /*
 880  * Returns < 0 on errors, 0 if no config file is given and > 0 if the config
 881  * file was read successfully.
 882  */
 883 static int parse_config_file(int override)
 884 {
 885         int ret, config_file_exists;
 886         char *config_file;
 887         struct stat statbuf;
 888         char *old_logfile_arg = NULL;
 889         int old_daemon_given = 0;
 890
 891         if (conf.config_file_given)
 892                 config_file = dss_strdup(conf.config_file_arg);
 893         else {
 894                 char *home = get_homedir();
 895                 config_file = make_message("%s/.dssrc", home);
 896                 free(home);
 897         }
 898         if (override) { /* SIGHUP */
 899                 if (conf.logfile_given)
 900                         old_logfile_arg = dss_strdup(conf.logfile_arg);
 901                 old_daemon_given = conf.daemon_given;
 902         }
 903
 904         config_file_exists = !stat(config_file, &statbuf);
 905         if (!config_file_exists && conf.config_file_given) {
 906                 ret = -ERRNO_TO_DSS_ERROR(errno);
 907                 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
 908                 goto out;
 909         }
 910         if (config_file_exists) {
 911                 struct cmdline_parser_params params = {
 912                         .override = override,
 913                         .initialize = 0,
 914                         .check_required = 1,
 915                         .check_ambiguity = 0,
 916                         .print_errors = 1
 917                 };
 918                 if (override) { /* invalidate all rsync options */
 919                         int i;
 920
 921                         for (i = 0; i < conf.rsync_option_given; i++) {
 922                                 free(conf.rsync_option_arg[i]);
 923                                 conf.rsync_option_arg[i] = NULL;
 924                         }
 925                         conf.rsync_option_given = 0;
 926                 }
 927                 cmdline_parser_config_file(config_file, &conf, &params);
 928         }
 929         ret = check_config();
 930         if (ret < 0)
 931                 goto out;
 932         if (override) {
 933                 /* don't change daemon mode on SIGHUP */
 934                 conf.daemon_given = old_daemon_given;
 935                 close_log(logfile);
 936                 logfile = NULL;
 937                 if (conf.logfile_given)
 938                         free(old_logfile_arg);
 939                 else if (conf.daemon_given) { /* re-use old logfile */
 940                         conf.logfile_arg = old_logfile_arg;
 941                         conf.logfile_given = 1;
 942                 }
 943         }
 944         if (conf.logfile_given && conf.run_given && conf.daemon_given) {
 945                 logfile = open_log(conf.logfile_arg);
 946                 log_welcome(conf.loglevel_arg);
 947         }
 948         DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
 949         ret = config_file_exists;
 950 out:
 951         free(config_file);
 952         if (ret < 0)
 953                 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
 954         return ret;
 955 }
 956
 957 static int change_to_dest_dir(void)
 958 {
 959         DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
 960         return dss_chdir(conf.dest_dir_arg);
 961 }
 962
 963 static int handle_sighup(void)
 964 {
 965         int ret;
 966
 967         DSS_NOTICE_LOG("SIGHUP, re-reading config\n");
 968         dump_dss_config("old");
 969         ret = parse_config_file(1);
 970         if (ret < 0)
 971                 return ret;
 972         dump_dss_config("reloaded");
 973         invalidate_next_snapshot_time();
 974         return change_to_dest_dir();
 975 }
 976
 977 static int handle_signal(void)
 978 {
 979         int sig, ret = next_signal();
 980
 981         if (ret <= 0)
 982                 goto out;
 983         sig = ret;
 984         switch (sig) {
 985         case SIGINT:
 986         case SIGTERM:
 987                 restart_create_process();
 988                 dss_kill(create_pid, SIGTERM, NULL);
 989                 dss_kill(remove_pid, SIGTERM, NULL);
 990                 ret = -E_SIGNAL;
 991                 break;
 992         case SIGHUP:
 993                 ret = handle_sighup();
 994                 break;
 995         case SIGCHLD:
 996                 ret = handle_sigchld();
 997                 break;
 998         }
 999 out:
1000         if (ret < 0)
1001                 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
1002         return ret;
1003 }
1004
1005 /*
1006  * We can not use rsync locally if the local user is different from the remote
1007  * user or if the src dir is not on the local host (or both).
1008  */
1009 static int use_rsync_locally(char *logname)
1010 {
1011         char *h = conf.remote_host_arg;
1012
1013         if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
1014                 return 0;
1015         if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
1016                 return 0;
1017         return 1;
1018 }
1019
1020 static int rename_resume_snap(int64_t creation_time)
1021 {
1022         struct snapshot_list sl = {.num_snapshots = 0};
1023         struct snapshot *s = NULL;
1024         char *new_name = incomplete_name(creation_time);
1025         int ret;
1026         const char *why;
1027
1028         ret = 0;
1029         if (conf.no_resume_given)
1030                 goto out;
1031         dss_get_snapshot_list(&sl);
1032         /*
1033          * Snapshot recycling: We first look at the newest snapshot. If this
1034          * snapshot happens to be incomplete, the last rsync process was
1035          * aborted and we reuse this one. Otherwise we look at snapshots which
1036          * could be removed (outdated and redundant snapshots) as candidates
1037          * for recycling. If no outdated/redundant snapshot exists, we check if
1038          * there is an orphaned snapshot, which likely is useless anyway.
1039          *
1040          * Only if no existing snapshot is suitable for recycling, we bite the
1041          * bullet and create a new one.
1042          */
1043         s = get_newest_snapshot(&sl);
1044         if (!s) /* no snapshots at all */
1045                 goto out;
1046         /* re-use last snapshot if it is incomplete */
1047         why = "aborted";
1048         if ((s->flags & SS_COMPLETE) == 0)
1049                 goto out;
1050         why = "outdated";
1051         s = find_outdated_snapshot(&sl);
1052         if (s)
1053                 goto out;
1054         why = "redundant";
1055         s = find_redundant_snapshot(&sl);
1056         if (s)
1057                 goto out;
1058         why = "orphaned";
1059         s = find_orphaned_snapshot(&sl);
1060 out:
1061         if (s) {
1062                 DSS_INFO_LOG("reusing %s snapshot %s\n", why, s->name);
1063                 ret = dss_rename(s->name, new_name);
1064         }
1065         if (ret >= 0)
1066                 DSS_NOTICE_LOG("creating new snapshot %s\n", new_name);
1067         free(new_name);
1068         free_snapshot_list(&sl);
1069         return ret;
1070 }
1071
1072 static void create_rsync_argv(char ***argv, int64_t *num)
1073 {
1074         char *logname;
1075         int i = 0, j;
1076         struct snapshot_list sl;
1077
1078         dss_get_snapshot_list(&sl);
1079         assert(!name_of_reference_snapshot);
1080         name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
1081         free_snapshot_list(&sl);
1082
1083         *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
1084         (*argv)[i++] = dss_strdup("rsync");
1085         (*argv)[i++] = dss_strdup("-aq");
1086         (*argv)[i++] = dss_strdup("--delete");
1087         for (j = 0; j < conf.rsync_option_given; j++)
1088                 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
1089         if (name_of_reference_snapshot) {
1090                 DSS_INFO_LOG("using %s as reference\n", name_of_reference_snapshot);
1091                 (*argv)[i++] = make_message("--link-dest=../%s",
1092                         name_of_reference_snapshot);
1093         } else
1094                 DSS_INFO_LOG("no suitable reference snapshot found\n");
1095         logname = dss_logname();
1096         if (use_rsync_locally(logname))
1097                 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
1098         else
1099                 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
1100                         conf.remote_user_arg : logname,
1101                         conf.remote_host_arg, conf.source_dir_arg);
1102         free(logname);
1103         *num = get_current_time();
1104         (*argv)[i++] = incomplete_name(*num);
1105         (*argv)[i++] = NULL;
1106         for (j = 0; j < i; j++)
1107                 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
1108 }
1109
1110 static void free_rsync_argv(char **argv)
1111 {
1112         int i;
1113
1114         if (!argv)
1115                 return;
1116         for (i = 0; argv[i]; i++)
1117                 free(argv[i]);
1118         free(argv);
1119 }
1120
1121 static int create_snapshot(char **argv)
1122 {
1123         int ret;
1124
1125         ret = rename_resume_snap(current_snapshot_creation_time);
1126         if (ret < 0)
1127                 return ret;
1128         dss_exec(&create_pid, argv[0], argv);
1129         snapshot_creation_status = HS_RUNNING;
1130         return ret;
1131 }
1132
1133 static int select_loop(void)
1134 {
1135         int ret;
1136         /* check every 60 seconds for free disk space */
1137         struct timeval tv;
1138         char **rsync_argv = NULL;
1139
1140         for (;;) {
1141                 fd_set rfds;
1142                 struct timeval *tvp;
1143
1144                 if (remove_pid)
1145                         tvp = NULL; /* sleep until rm hook/process dies */
1146                 else { /* sleep one minute */
1147                         tv.tv_sec = 60;
1148                         tv.tv_usec = 0;
1149                         tvp = &tv;
1150                 }
1151                 FD_ZERO(&rfds);
1152                 FD_SET(signal_pipe, &rfds);
1153                 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1154                 if (ret < 0)
1155                         goto out;
1156                 if (FD_ISSET(signal_pipe, &rfds)) {
1157                         ret = handle_signal();
1158                         if (ret < 0)
1159                                 goto out;
1160                 }
1161                 if (remove_pid)
1162                         continue;
1163                 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1164                         ret = exec_rm();
1165                         if (ret < 0)
1166                                 goto out;
1167                         continue;
1168                 }
1169                 if (snapshot_removal_status == HS_SUCCESS) {
1170                         post_remove_hook();
1171                         continue;
1172                 }
1173                 ret = try_to_free_disk_space();
1174                 if (ret < 0)
1175                         goto out;
1176                 if (snapshot_removal_status != HS_READY) {
1177                         stop_create_process();
1178                         continue;
1179                 }
1180                 restart_create_process();
1181                 switch (snapshot_creation_status) {
1182                 case HS_READY:
1183                         if (!next_snapshot_is_due())
1184                                 continue;
1185                         pre_create_hook();
1186                         continue;
1187                 case HS_PRE_RUNNING:
1188                 case HS_RUNNING:
1189                 case HS_POST_RUNNING:
1190                         continue;
1191                 case HS_PRE_SUCCESS:
1192                         if (!name_of_reference_snapshot) {
1193                                 free_rsync_argv(rsync_argv);
1194                                 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1195                         }
1196                         ret = create_snapshot(rsync_argv);
1197                         if (ret < 0)
1198                                 goto out;
1199                         continue;
1200                 case HS_NEEDS_RESTART:
1201                         if (!next_snapshot_is_due())
1202                                 continue;
1203                         ret = create_snapshot(rsync_argv);
1204                         if (ret < 0)
1205                                 goto out;
1206                         continue;
1207                 case HS_SUCCESS:
1208                         post_create_hook();
1209                         continue;
1210                 }
1211         }
1212 out:
1213         return ret;
1214 }
1215
1216 static void exit_hook(int exit_code)
1217 {
1218         char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
1219         pid_t pid;
1220
1221         DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
1222         dss_exec(&pid, conf.exit_hook_arg, argv);
1223 }
1224
1225 static int com_run(void)
1226 {
1227         int ret;
1228
1229         if (conf.dry_run_given) {
1230                 DSS_ERROR_LOG("dry_run not supported by this command\n");
1231                 return -E_SYNTAX;
1232         }
1233         ret = install_sighandler(SIGHUP);
1234         if (ret < 0)
1235                 return ret;
1236         ret = select_loop();
1237         if (ret >= 0) /* impossible */
1238                 ret = -E_BUG;
1239         exit_hook(ret);
1240         return ret;
1241 }
1242
1243 static int com_prune(void)
1244 {
1245         int ret;
1246         struct snapshot_list sl;
1247         struct snapshot *victim;
1248         struct disk_space ds;
1249         const char *why;
1250
1251         ret = get_disk_space(".", &ds);
1252         if (ret < 0)
1253                 return ret;
1254         log_disk_space(&ds);
1255         dss_get_snapshot_list(&sl);
1256         why = "outdated";
1257         victim = find_outdated_snapshot(&sl);
1258         if (victim)
1259                 goto rm;
1260         why = "redundant";
1261         victim = find_redundant_snapshot(&sl);
1262         if (victim)
1263                 goto rm;
1264         ret = 0;
1265         goto out;
1266 rm:
1267         if (conf.dry_run_given) {
1268                 dss_msg("%s snapshot %s (interval = %i)\n",
1269                         why, victim->name, victim->interval);
1270                 ret = 0;
1271                 goto out;
1272         }
1273         pre_remove_hook(victim, why);
1274         if (snapshot_removal_status == HS_PRE_RUNNING) {
1275                 ret = wait_for_remove_process();
1276                 if (ret < 0)
1277                         goto out;
1278                 if (snapshot_removal_status != HS_PRE_SUCCESS)
1279                         goto out;
1280         }
1281         ret = exec_rm();
1282         if (ret < 0)
1283                 goto out;
1284         ret = wait_for_remove_process();
1285         if (ret < 0)
1286                 goto out;
1287         if (snapshot_removal_status != HS_SUCCESS)
1288                 goto out;
1289         post_remove_hook();
1290         if (snapshot_removal_status != HS_POST_RUNNING)
1291                 goto out;
1292         ret = wait_for_remove_process();
1293         if (ret < 0)
1294                 goto out;
1295         ret = 1;
1296 out:
1297         free_snapshot_list(&sl);
1298         return ret;
1299 }
1300
1301 static int com_create(void)
1302 {
1303         int ret, status;
1304         char **rsync_argv;
1305
1306         if (conf.dry_run_given) {
1307                 int i;
1308                 char *msg = NULL;
1309                 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1310                 for (i = 0; rsync_argv[i]; i++) {
1311                         char *tmp = msg;
1312                         msg = make_message("%s%s%s", tmp? tmp : "",
1313                                 tmp? " " : "", rsync_argv[i]);
1314                         free(tmp);
1315                 }
1316                 free_rsync_argv(rsync_argv);
1317                 dss_msg("%s\n", msg);
1318                 free(msg);
1319                 return 1;
1320         }
1321         pre_create_hook();
1322         if (create_pid) {
1323                 ret = wait_for_process(create_pid, &status);
1324                 if (ret < 0)
1325                         return ret;
1326                 ret = handle_pre_create_hook_exit(status);
1327                 if (ret <= 0) /* error, or pre-create failed */
1328                         return ret;
1329         }
1330         create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1331         ret = create_snapshot(rsync_argv);
1332         if (ret < 0)
1333                 goto out;
1334         ret = wait_for_process(create_pid, &status);
1335         if (ret < 0)
1336                 goto out;
1337         ret = handle_rsync_exit(status);
1338         if (ret < 0)
1339                 goto out;
1340         post_create_hook();
1341         if (create_pid)
1342                 ret = wait_for_process(create_pid, &status);
1343 out:
1344         free_rsync_argv(rsync_argv);
1345         return ret;
1346 }
1347
1348 static int com_ls(void)
1349 {
1350         int i;
1351         struct snapshot_list sl;
1352         struct snapshot *s;
1353
1354         dss_get_snapshot_list(&sl);
1355         FOR_EACH_SNAPSHOT(s, i, &sl) {
1356                 int64_t d = 0;
1357                 if (s->flags & SS_COMPLETE)
1358                         d = (s->completion_time - s->creation_time) / 60;
1359                 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1360         };
1361         free_snapshot_list(&sl);
1362         return 1;
1363 }
1364
1365 static int setup_signal_handling(void)
1366 {
1367         int ret;
1368
1369         DSS_INFO_LOG("setting up signal handlers\n");
1370         signal_pipe = signal_init(); /* always successful */
1371         ret = install_sighandler(SIGINT);
1372         if (ret < 0)
1373                 return ret;
1374         ret = install_sighandler(SIGTERM);
1375         if (ret < 0)
1376                 return ret;
1377         return install_sighandler(SIGCHLD);
1378 }
1379
1380 /**
1381  * The main function of dss.
1382  *
1383  * \param argc Usual argument count.
1384  * \param argv Usual argument vector.
1385  */
1386 int main(int argc, char **argv)
1387 {
1388         int ret;
1389         struct cmdline_parser_params params = {
1390                 .override = 0,
1391                 .initialize = 1,
1392                 .check_required = 0,
1393                 .check_ambiguity = 0,
1394                 .print_errors = 1
1395         };
1396
1397         cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1398         ret = parse_config_file(0);
1399         if (ret < 0)
1400                 goto out;
1401         if (ret == 0) { /* no config file given */
1402                 /*
1403                  * Parse the command line options again, but this time check
1404                  * that all required options are given.
1405                  */
1406                 params = (struct cmdline_parser_params) {
1407                         .override = 1,
1408                         .initialize = 1,
1409                         .check_required = 1,
1410                         .check_ambiguity = 1,
1411                         .print_errors = 1
1412                 };
1413                 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1414         }
1415         if (conf.daemon_given)
1416                 daemon_init();
1417         ret = change_to_dest_dir();
1418         if (ret < 0)
1419                 goto out;
1420         dump_dss_config("startup");
1421         ret = setup_signal_handling();
1422         if (ret < 0)
1423                 goto out;
1424         ret = call_command_handler();
1425 out:
1426         if (ret < 0)
1427                 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1428         exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1429 }