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[4];
 328         int ret;
 329
 330         argv[0] = "rm";
 331         argv[1] = "-rf";
 332         argv[2] = new_name;
 333         argv[3] = NULL;
 334
 335         assert(snapshot_removal_status == HS_PRE_SUCCESS);
 336         assert(remove_pid == 0);
 337
 338         DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
 339         ret = dss_rename(s->name, new_name);
 340         if (ret < 0)
 341                 goto out;
 342         dss_exec(&remove_pid, argv[0], argv);
 343         snapshot_removal_status = HS_RUNNING;
 344 out:
 345         free(new_name);
 346         return ret;
 347 }
 348
 349 static int snapshot_is_being_created(struct snapshot *s)
 350 {
 351         return s->creation_time == current_snapshot_creation_time;
 352 }
 353
 354 static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl)
 355 {
 356         struct snapshot *s;
 357         int i;
 358
 359         DSS_DEBUG_LOG("looking for orphaned snapshots\n");
 360         FOR_EACH_SNAPSHOT(s, i, sl) {
 361                 if (snapshot_is_being_created(s))
 362                         continue;
 363                 /*
 364                  * We know that no rm is currently running, so if s is marked
 365                  * as being deleted, a previously started rm must have failed.
 366                  */
 367                 if (s->flags & SS_BEING_DELETED)
 368                         return s;
 369
 370                 if (s->flags & SS_COMPLETE) /* good snapshot */
 371                         continue;
 372                 /*
 373                  * This snapshot is incomplete and it is not the snapshot
 374                  * currently being created. However, we must not remove it if
 375                  * rsync is about to be restarted. As only the newest snapshot
 376                  * can be restarted, this snapshot is orphaned if it is not the
 377                  * newest snapshot or if we are not about to restart rsync.
 378                  */
 379                 if (get_newest_snapshot(sl) != s)
 380                         return s;
 381                 if (snapshot_creation_status != HS_NEEDS_RESTART)
 382                         return s;
 383         }
 384         /* no orphaned snapshots */
 385         return NULL;
 386 }
 387
 388 static int is_reference_snapshot(struct snapshot *s)
 389 {
 390         if (!name_of_reference_snapshot)
 391                 return 0;
 392         return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
 393 }
 394
 395 /*
 396  * return: 0: no redundant snapshots, 1: rm process started, negative: error
 397  */
 398 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
 399 {
 400         int i, interval;
 401         struct snapshot *s;
 402         unsigned missing = 0;
 403
 404         DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
 405         for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
 406                 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
 407                 unsigned num = sl->interval_count[interval];
 408                 struct snapshot *victim = NULL, *prev = NULL;
 409                 int64_t score = LONG_MAX;
 410
 411                 if (keep >= num)
 412                         missing += keep - num;
 413 //              DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
 414 //                      interval, keep, num, missing);
 415                 if (keep + missing >= num)
 416                         continue;
 417                 /* redundant snapshot in this interval, pick snapshot with lowest score */
 418                 FOR_EACH_SNAPSHOT(s, i, sl) {
 419                         int64_t this_score;
 420
 421                         if (snapshot_is_being_created(s))
 422                                 continue;
 423                         if (is_reference_snapshot(s))
 424                                 continue;
 425                         //DSS_DEBUG_LOG("checking %s\n", s->name);
 426                         if (s->interval > interval) {
 427                                 prev = s;
 428                                 continue;
 429                         }
 430                         if (s->interval < interval)
 431                                 break;
 432                         if (!victim) {
 433                                 victim = s;
 434                                 prev = s;
 435                                 continue;
 436                         }
 437                         assert(prev);
 438                         /* check if s is a better victim */
 439                         this_score = s->creation_time - prev->creation_time;
 440                         assert(this_score >= 0);
 441                         //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
 442                         if (this_score < score) {
 443                                 score = this_score;
 444                                 victim = s;
 445                         }
 446                         prev = s;
 447                 }
 448                 assert(victim);
 449                 return victim;
 450         }
 451         return NULL;
 452 }
 453
 454 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
 455 {
 456         int i;
 457         struct snapshot *s;
 458
 459         DSS_DEBUG_LOG("looking for snapshots belonging to intervals >= %d\n",
 460                 conf.num_intervals_arg);
 461         FOR_EACH_SNAPSHOT(s, i, sl) {
 462                 if (snapshot_is_being_created(s))
 463                         continue;
 464                 if (is_reference_snapshot(s))
 465                         continue;
 466                 if (s->interval < conf.num_intervals_arg)
 467                         continue;
 468                 return s;
 469         }
 470         return NULL;
 471 }
 472
 473 struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
 474 {
 475         int i;
 476         struct snapshot *s;
 477         FOR_EACH_SNAPSHOT(s, i, sl) {
 478                 if (snapshot_is_being_created(s))
 479                         continue;
 480                 if (is_reference_snapshot(s))
 481                         continue;
 482                 DSS_INFO_LOG("oldest removable snapshot: %s\n", s->name);
 483                 return s;
 484         }
 485         return NULL;
 486 }
 487
 488 static int rename_incomplete_snapshot(int64_t start)
 489 {
 490         char *old_name;
 491         int ret;
 492
 493         free(path_to_last_complete_snapshot);
 494         ret = complete_name(start, get_current_time(),
 495                 &path_to_last_complete_snapshot);
 496         if (ret < 0)
 497                 return ret;
 498         old_name = incomplete_name(start);
 499         ret = dss_rename(old_name, path_to_last_complete_snapshot);
 500         if (ret >= 0)
 501                 DSS_NOTICE_LOG("%s -> %s\n", old_name,
 502                         path_to_last_complete_snapshot);
 503         free(old_name);
 504         return ret;
 505 }
 506
 507 static int try_to_free_disk_space(void)
 508 {
 509         int ret;
 510         struct snapshot_list sl;
 511         struct snapshot *victim;
 512         struct timeval now;
 513         const char *why;
 514         int low_disk_space;
 515
 516         ret = disk_space_low(NULL);
 517         if (ret < 0)
 518                 return ret;
 519         low_disk_space = ret;
 520         gettimeofday(&now, NULL);
 521         if (tv_diff(&next_removal_check, &now, NULL) > 0)
 522                 return 0;
 523         if (!low_disk_space) {
 524                 if (conf.keep_redundant_given)
 525                         return 0;
 526                 if (snapshot_creation_status != HS_READY)
 527                         return 0;
 528                 if (next_snapshot_is_due())
 529                         return 0;
 530         }
 531         dss_get_snapshot_list(&sl);
 532         ret = 0;
 533         if (!low_disk_space && sl.num_snapshots <= 1)
 534                 goto out;
 535         why = "outdated";
 536         victim = find_outdated_snapshot(&sl);
 537         if (victim)
 538                 goto remove;
 539         why = "redundant";
 540         victim = find_redundant_snapshot(&sl);
 541         if (victim)
 542                 goto remove;
 543         /* try harder only if disk space is low */
 544         if (!low_disk_space)
 545                 goto out;
 546         why = "orphaned";
 547         victim = find_orphaned_snapshot(&sl);
 548         if (victim)
 549                 goto remove;
 550         DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
 551         victim = find_oldest_removable_snapshot(&sl);
 552         if (victim)
 553                 goto remove;
 554         DSS_CRIT_LOG("uhuhu: disk space low and nothing to remove\n");
 555         ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
 556         goto out;
 557 remove:
 558         pre_remove_hook(victim, why);
 559 out:
 560         free_snapshot_list(&sl);
 561         return ret;
 562 }
 563
 564 static void post_create_hook(void)
 565 {
 566         char *cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
 567                 conf.dest_dir_arg, path_to_last_complete_snapshot);
 568         DSS_NOTICE_LOG("executing %s\n", cmd);
 569         dss_exec_cmdline_pid(&create_pid, cmd);
 570         free(cmd);
 571         snapshot_creation_status = HS_POST_RUNNING;
 572 }
 573
 574 static void post_remove_hook(void)
 575 {
 576         char *cmd;
 577         struct snapshot *s = snapshot_currently_being_removed;
 578
 579         assert(s);
 580
 581         cmd = make_message("%s %s/%s", conf.post_remove_hook_arg,
 582                 conf.dest_dir_arg, s->name);
 583         DSS_NOTICE_LOG("executing %s\n", cmd);
 584         dss_exec_cmdline_pid(&remove_pid, cmd);
 585         free(cmd);
 586         snapshot_removal_status = HS_POST_RUNNING;
 587 }
 588
 589 static void dss_kill(pid_t pid, int sig, const char *msg)
 590 {
 591         const char *signame, *process_name;
 592
 593         if (pid == 0)
 594                 return;
 595         switch (sig) {
 596         case SIGTERM: signame = "TERM"; break;
 597         case SIGSTOP: signame = "STOP"; break;
 598         case SIGCONT: signame = "CONT"; break;
 599         default: signame = "????";
 600         }
 601
 602         if (pid == create_pid)
 603                 process_name = "create";
 604         else if (pid == remove_pid)
 605                 process_name = "remove";
 606         else process_name = "??????";
 607
 608         if (msg)
 609                 DSS_INFO_LOG("%s\n", msg);
 610         DSS_DEBUG_LOG("sending signal %d (%s) to pid %d (%s process)\n",
 611                 sig, signame, (int)pid, process_name);
 612         if (kill(pid, sig) >= 0)
 613                 return;
 614         DSS_INFO_LOG("failed to send signal %d (%s) to pid %d (%s process)\n",
 615                 sig, signame, (int)pid, process_name);
 616 }
 617
 618 static void stop_create_process(void)
 619 {
 620         if (create_process_stopped)
 621                 return;
 622         dss_kill(create_pid, SIGSTOP, "suspending create process");
 623         create_process_stopped = 1;
 624 }
 625
 626 static void restart_create_process(void)
 627 {
 628         if (!create_process_stopped)
 629                 return;
 630         dss_kill(create_pid, SIGCONT, "resuming create process");
 631         create_process_stopped = 0;
 632 }
 633
 634 /**
 635  * Print a log message about the exit status of a child.
 636  */
 637 static void log_termination_msg(pid_t pid, int status)
 638 {
 639         if (WIFEXITED(status))
 640                 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
 641                         WEXITSTATUS(status));
 642         else if (WIFSIGNALED(status))
 643                 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
 644                         WTERMSIG(status));
 645         else
 646                 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
 647 }
 648
 649 static int wait_for_process(pid_t pid, int *status)
 650 {
 651         int ret;
 652
 653         DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
 654         for (;;) {
 655                 fd_set rfds;
 656
 657                 FD_ZERO(&rfds);
 658                 FD_SET(signal_pipe, &rfds);
 659                 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
 660                 if (ret < 0)
 661                         break;
 662                 ret = next_signal();
 663                 if (!ret)
 664                         continue;
 665                 if (ret == SIGCHLD) {
 666                         ret = waitpid(pid, status, 0);
 667                         if (ret >= 0)
 668                                 break;
 669                         if (errno != EINTR) { /* error */
 670                                 ret = -ERRNO_TO_DSS_ERROR(errno);
 671                                 break;
 672                         }
 673                 }
 674                 /* SIGINT or SIGTERM */
 675                 dss_kill(pid, SIGTERM, "killing child process");
 676         }
 677         if (ret < 0)
 678                 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
 679         else
 680                 log_termination_msg(pid, *status);
 681         return ret;
 682 }
 683
 684 static void handle_pre_remove_exit(int status)
 685 {
 686         if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 687                 snapshot_removal_status = HS_READY;
 688                 gettimeofday(&next_removal_check, NULL);
 689                 next_removal_check.tv_sec += 60;
 690                 return;
 691         }
 692         snapshot_removal_status = HS_PRE_SUCCESS;
 693 }
 694
 695 static int handle_rm_exit(int status)
 696 {
 697         if (!WIFEXITED(status)) {
 698                 snapshot_removal_status = HS_READY;
 699                 return -E_INVOLUNTARY_EXIT;
 700         }
 701         if (WEXITSTATUS(status)) {
 702                 snapshot_removal_status = HS_READY;
 703                 return -E_BAD_EXIT_CODE;
 704         }
 705         snapshot_removal_status = HS_SUCCESS;
 706         return 1;
 707 }
 708
 709 static void handle_post_remove_exit(void)
 710 {
 711         snapshot_removal_status = HS_READY;
 712 }
 713
 714 static int handle_remove_exit(int status)
 715 {
 716         int ret;
 717         struct snapshot *s = snapshot_currently_being_removed;
 718
 719         assert(s);
 720         switch (snapshot_removal_status) {
 721         case HS_PRE_RUNNING:
 722                 handle_pre_remove_exit(status);
 723                 ret = 1;
 724                 break;
 725         case HS_RUNNING:
 726                 ret = handle_rm_exit(status);
 727                 break;
 728         case HS_POST_RUNNING:
 729                 handle_post_remove_exit();
 730                 ret = 1;
 731                 break;
 732         default:
 733                 ret = -E_BUG;
 734         }
 735         if (snapshot_removal_status == HS_READY) {
 736                 free(s->name);
 737                 free(s);
 738                 snapshot_currently_being_removed = NULL;
 739         }
 740         remove_pid = 0;
 741         return ret;
 742 }
 743
 744 static int wait_for_remove_process(void)
 745 {
 746         int status, ret;
 747
 748         assert(remove_pid);
 749         assert(
 750                 snapshot_removal_status == HS_PRE_RUNNING ||
 751                 snapshot_removal_status == HS_RUNNING ||
 752                 snapshot_removal_status == HS_POST_RUNNING
 753         );
 754         ret = wait_for_process(remove_pid, &status);
 755         if (ret < 0)
 756                 return ret;
 757         return handle_remove_exit(status);
 758 }
 759
 760 static int handle_rsync_exit(int status)
 761 {
 762         int es, ret;
 763
 764         if (!WIFEXITED(status)) {
 765                 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)create_pid);
 766                 ret = -E_INVOLUNTARY_EXIT;
 767                 snapshot_creation_status = HS_READY;
 768                 goto out;
 769         }
 770         es = WEXITSTATUS(status);
 771         /*
 772          * Restart rsync on non-fatal errors:
 773          * 12: Error in rsync protocol data stream
 774          * 13: Errors with program diagnostics
 775          */
 776         if (es == 12 || es == 13) {
 777                 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
 778                         (int)create_pid, es);
 779                 snapshot_creation_status = HS_NEEDS_RESTART;
 780                 next_snapshot_time = get_current_time() + 60;
 781                 ret = 1;
 782                 goto out;
 783         }
 784         if (es != 0 && es != 23 && es != 24) {
 785                 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)create_pid, es);
 786                 ret = -E_BAD_EXIT_CODE;
 787                 snapshot_creation_status = HS_READY;
 788                 goto out;
 789         }
 790         ret = rename_incomplete_snapshot(current_snapshot_creation_time);
 791         if (ret < 0)
 792                 goto out;
 793         snapshot_creation_status = HS_SUCCESS;
 794         free(name_of_reference_snapshot);
 795         name_of_reference_snapshot = NULL;
 796 out:
 797         create_process_stopped = 0;
 798         return ret;
 799 }
 800
 801 static int handle_pre_create_hook_exit(int status)
 802 {
 803         int es, ret;
 804         static int warn_count;
 805
 806         if (!WIFEXITED(status)) {
 807                 snapshot_creation_status = HS_READY;
 808                 ret = -E_INVOLUNTARY_EXIT;
 809                 goto out;
 810         }
 811         es = WEXITSTATUS(status);
 812         if (es) {
 813                 if (!warn_count--) {
 814                         DSS_NOTICE_LOG("pre_create_hook %s returned %d\n",
 815                                 conf.pre_create_hook_arg, es);
 816                         DSS_NOTICE_LOG("deferring snapshot creation...\n");
 817                         warn_count = 60; /* warn only once per hour */
 818                 }
 819                 next_snapshot_time = get_current_time() + 60;
 820                 snapshot_creation_status = HS_READY;
 821                 ret = 0;
 822                 goto out;
 823         }
 824         warn_count = 0;
 825         snapshot_creation_status = HS_PRE_SUCCESS;
 826         ret = 1;
 827 out:
 828         return ret;
 829 }
 830
 831 static int handle_sigchld(void)
 832 {
 833         pid_t pid;
 834         int status, ret = reap_child(&pid, &status);
 835
 836         if (ret <= 0)
 837                 return ret;
 838
 839         if (pid == create_pid) {
 840                 switch (snapshot_creation_status) {
 841                 case HS_PRE_RUNNING:
 842                         ret = handle_pre_create_hook_exit(status);
 843                         break;
 844                 case HS_RUNNING:
 845                         ret = handle_rsync_exit(status);
 846                         break;
 847                 case HS_POST_RUNNING:
 848                         snapshot_creation_status = HS_READY;
 849                         ret = 1;
 850                         break;
 851                 default:
 852                         DSS_EMERG_LOG("BUG: create can't die in status %d\n",
 853                                 snapshot_creation_status);
 854                         return -E_BUG;
 855                 }
 856                 create_pid = 0;
 857                 return ret;
 858         }
 859         if (pid == remove_pid) {
 860                 ret = handle_remove_exit(status);
 861                 if (ret < 0)
 862                         return ret;
 863                 return ret;
 864         }
 865         DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
 866         return -E_BUG;
 867 }
 868
 869 static int check_config(void)
 870 {
 871         if (conf.unit_interval_arg <= 0) {
 872                 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
 873                 return -E_INVALID_NUMBER;
 874         }
 875         DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
 876         if (conf.num_intervals_arg <= 0) {
 877                 DSS_ERROR_LOG("bad number of intervals  %i\n", conf.num_intervals_arg);
 878                 return -E_INVALID_NUMBER;
 879         }
 880         DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
 881         return 1;
 882 }
 883
 884 /*
 885  * Returns < 0 on errors, 0 if no config file is given and > 0 if the config
 886  * file was read successfully.
 887  */
 888 static int parse_config_file(int override)
 889 {
 890         int ret, config_file_exists;
 891         char *config_file;
 892         struct stat statbuf;
 893         char *old_logfile_arg = NULL;
 894         int old_daemon_given = 0;
 895
 896         if (conf.config_file_given)
 897                 config_file = dss_strdup(conf.config_file_arg);
 898         else {
 899                 char *home = get_homedir();
 900                 config_file = make_message("%s/.dssrc", home);
 901                 free(home);
 902         }
 903         if (override) { /* SIGHUP */
 904                 if (conf.logfile_given)
 905                         old_logfile_arg = dss_strdup(conf.logfile_arg);
 906                 old_daemon_given = conf.daemon_given;
 907         }
 908
 909         config_file_exists = !stat(config_file, &statbuf);
 910         if (!config_file_exists && conf.config_file_given) {
 911                 ret = -ERRNO_TO_DSS_ERROR(errno);
 912                 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
 913                 goto out;
 914         }
 915         if (config_file_exists) {
 916                 struct cmdline_parser_params params = {
 917                         .override = override,
 918                         .initialize = 0,
 919                         .check_required = 1,
 920                         .check_ambiguity = 0,
 921                         .print_errors = 1
 922                 };
 923                 if (override) { /* invalidate all rsync options */
 924                         int i;
 925
 926                         for (i = 0; i < conf.rsync_option_given; i++) {
 927                                 free(conf.rsync_option_arg[i]);
 928                                 conf.rsync_option_arg[i] = NULL;
 929                         }
 930                         conf.rsync_option_given = 0;
 931                 }
 932                 cmdline_parser_config_file(config_file, &conf, &params);
 933         }
 934         ret = check_config();
 935         if (ret < 0)
 936                 goto out;
 937         if (override) {
 938                 /* don't change daemon mode on SIGHUP */
 939                 conf.daemon_given = old_daemon_given;
 940                 close_log(logfile);
 941                 logfile = NULL;
 942                 if (conf.logfile_given)
 943                         free(old_logfile_arg);
 944                 else if (conf.daemon_given) { /* re-use old logfile */
 945                         conf.logfile_arg = old_logfile_arg;
 946                         conf.logfile_given = 1;
 947                 }
 948         }
 949         if (conf.logfile_given && conf.run_given && conf.daemon_given) {
 950                 logfile = open_log(conf.logfile_arg);
 951                 log_welcome(conf.loglevel_arg);
 952         }
 953         DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
 954         ret = config_file_exists;
 955 out:
 956         free(config_file);
 957         if (ret < 0)
 958                 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
 959         return ret;
 960 }
 961
 962 static int change_to_dest_dir(void)
 963 {
 964         DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
 965         return dss_chdir(conf.dest_dir_arg);
 966 }
 967
 968 static int handle_sighup(void)
 969 {
 970         int ret;
 971
 972         DSS_NOTICE_LOG("SIGHUP, re-reading config\n");
 973         dump_dss_config("old");
 974         ret = parse_config_file(1);
 975         if (ret < 0)
 976                 return ret;
 977         dump_dss_config("reloaded");
 978         invalidate_next_snapshot_time();
 979         return change_to_dest_dir();
 980 }
 981
 982 static int handle_signal(void)
 983 {
 984         int sig, ret = next_signal();
 985
 986         if (ret <= 0)
 987                 goto out;
 988         sig = ret;
 989         switch (sig) {
 990         case SIGINT:
 991         case SIGTERM:
 992                 restart_create_process();
 993                 dss_kill(create_pid, SIGTERM, NULL);
 994                 dss_kill(remove_pid, SIGTERM, NULL);
 995                 ret = -E_SIGNAL;
 996                 break;
 997         case SIGHUP:
 998                 ret = handle_sighup();
 999                 break;
1000         case SIGCHLD:
1001                 ret = handle_sigchld();
1002                 break;
1003         }
1004 out:
1005         if (ret < 0)
1006                 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
1007         return ret;
1008 }
1009
1010 /*
1011  * We can not use rsync locally if the local user is different from the remote
1012  * user or if the src dir is not on the local host (or both).
1013  */
1014 static int use_rsync_locally(char *logname)
1015 {
1016         char *h = conf.remote_host_arg;
1017
1018         if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
1019                 return 0;
1020         if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
1021                 return 0;
1022         return 1;
1023 }
1024
1025 static int rename_resume_snap(int64_t creation_time)
1026 {
1027         struct snapshot_list sl = {.num_snapshots = 0};
1028         struct snapshot *s = NULL;
1029         char *new_name = incomplete_name(creation_time);
1030         int ret;
1031         const char *why;
1032
1033         ret = 0;
1034         if (conf.no_resume_given)
1035                 goto out;
1036         dss_get_snapshot_list(&sl);
1037         /*
1038          * Snapshot recycling: We first look at the newest snapshot. If this
1039          * snapshot happens to be incomplete, the last rsync process was
1040          * aborted and we reuse this one. Otherwise we look at snapshots which
1041          * could be removed (outdated and redundant snapshots) as candidates
1042          * for recycling. If no outdated/redundant snapshot exists, we check if
1043          * there is an orphaned snapshot, which likely is useless anyway.
1044          *
1045          * Only if no existing snapshot is suitable for recycling, we bite the
1046          * bullet and create a new one.
1047          */
1048         s = get_newest_snapshot(&sl);
1049         if (!s) /* no snapshots at all */
1050                 goto out;
1051         /* re-use last snapshot if it is incomplete */
1052         why = "aborted";
1053         if ((s->flags & SS_COMPLETE) == 0)
1054                 goto out;
1055         why = "outdated";
1056         s = find_outdated_snapshot(&sl);
1057         if (s)
1058                 goto out;
1059         why = "redundant";
1060         s = find_redundant_snapshot(&sl);
1061         if (s)
1062                 goto out;
1063         why = "orphaned";
1064         s = find_orphaned_snapshot(&sl);
1065 out:
1066         if (s) {
1067                 DSS_INFO_LOG("reusing %s snapshot %s\n", why, s->name);
1068                 ret = dss_rename(s->name, new_name);
1069         }
1070         if (ret >= 0)
1071                 DSS_NOTICE_LOG("creating new snapshot %s\n", new_name);
1072         free(new_name);
1073         free_snapshot_list(&sl);
1074         return ret;
1075 }
1076
1077 static void create_rsync_argv(char ***argv, int64_t *num)
1078 {
1079         char *logname;
1080         int i = 0, j;
1081         struct snapshot_list sl;
1082
1083         dss_get_snapshot_list(&sl);
1084         assert(!name_of_reference_snapshot);
1085         name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
1086         free_snapshot_list(&sl);
1087
1088         *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
1089         (*argv)[i++] = dss_strdup("rsync");
1090         (*argv)[i++] = dss_strdup("-aq");
1091         (*argv)[i++] = dss_strdup("--delete");
1092         for (j = 0; j < conf.rsync_option_given; j++)
1093                 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
1094         if (name_of_reference_snapshot) {
1095                 DSS_INFO_LOG("using %s as reference\n", name_of_reference_snapshot);
1096                 (*argv)[i++] = make_message("--link-dest=../%s",
1097                         name_of_reference_snapshot);
1098         } else
1099                 DSS_INFO_LOG("no suitable reference snapshot found\n");
1100         logname = dss_logname();
1101         if (use_rsync_locally(logname))
1102                 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
1103         else
1104                 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
1105                         conf.remote_user_arg : logname,
1106                         conf.remote_host_arg, conf.source_dir_arg);
1107         free(logname);
1108         *num = get_current_time();
1109         (*argv)[i++] = incomplete_name(*num);
1110         (*argv)[i++] = NULL;
1111         for (j = 0; j < i; j++)
1112                 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
1113 }
1114
1115 static void free_rsync_argv(char **argv)
1116 {
1117         int i;
1118
1119         if (!argv)
1120                 return;
1121         for (i = 0; argv[i]; i++)
1122                 free(argv[i]);
1123         free(argv);
1124 }
1125
1126 static int create_snapshot(char **argv)
1127 {
1128         int ret;
1129
1130         ret = rename_resume_snap(current_snapshot_creation_time);
1131         if (ret < 0)
1132                 return ret;
1133         dss_exec(&create_pid, argv[0], argv);
1134         snapshot_creation_status = HS_RUNNING;
1135         return ret;
1136 }
1137
1138 static int select_loop(void)
1139 {
1140         int ret;
1141         /* check every 60 seconds for free disk space */
1142         struct timeval tv;
1143         char **rsync_argv = NULL;
1144
1145         for (;;) {
1146                 fd_set rfds;
1147                 struct timeval *tvp;
1148
1149                 if (remove_pid)
1150                         tvp = NULL; /* sleep until rm hook/process dies */
1151                 else { /* sleep one minute */
1152                         tv.tv_sec = 60;
1153                         tv.tv_usec = 0;
1154                         tvp = &tv;
1155                 }
1156                 FD_ZERO(&rfds);
1157                 FD_SET(signal_pipe, &rfds);
1158                 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1159                 if (ret < 0)
1160                         goto out;
1161                 if (FD_ISSET(signal_pipe, &rfds)) {
1162                         ret = handle_signal();
1163                         if (ret < 0)
1164                                 goto out;
1165                 }
1166                 if (remove_pid)
1167                         continue;
1168                 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1169                         ret = exec_rm();
1170                         if (ret < 0)
1171                                 goto out;
1172                         continue;
1173                 }
1174                 if (snapshot_removal_status == HS_SUCCESS) {
1175                         post_remove_hook();
1176                         continue;
1177                 }
1178                 ret = try_to_free_disk_space();
1179                 if (ret < 0)
1180                         goto out;
1181                 if (snapshot_removal_status != HS_READY) {
1182                         stop_create_process();
1183                         continue;
1184                 }
1185                 restart_create_process();
1186                 switch (snapshot_creation_status) {
1187                 case HS_READY:
1188                         if (!next_snapshot_is_due())
1189                                 continue;
1190                         pre_create_hook();
1191                         continue;
1192                 case HS_PRE_RUNNING:
1193                 case HS_RUNNING:
1194                 case HS_POST_RUNNING:
1195                         continue;
1196                 case HS_PRE_SUCCESS:
1197                         if (!name_of_reference_snapshot) {
1198                                 free_rsync_argv(rsync_argv);
1199                                 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1200                         }
1201                         ret = create_snapshot(rsync_argv);
1202                         if (ret < 0)
1203                                 goto out;
1204                         continue;
1205                 case HS_NEEDS_RESTART:
1206                         if (!next_snapshot_is_due())
1207                                 continue;
1208                         ret = create_snapshot(rsync_argv);
1209                         if (ret < 0)
1210                                 goto out;
1211                         continue;
1212                 case HS_SUCCESS:
1213                         post_create_hook();
1214                         continue;
1215                 }
1216         }
1217 out:
1218         return ret;
1219 }
1220
1221 static void exit_hook(int exit_code)
1222 {
1223         char *argv[3];
1224         pid_t pid;
1225
1226         argv[0] = conf.exit_hook_arg;
1227         argv[1] = dss_strerror(-exit_code);
1228         argv[2] = NULL;
1229
1230         DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
1231         dss_exec(&pid, conf.exit_hook_arg, argv);
1232 }
1233
1234 static int com_run(void)
1235 {
1236         int ret;
1237
1238         if (conf.dry_run_given) {
1239                 DSS_ERROR_LOG("dry_run not supported by this command\n");
1240                 return -E_SYNTAX;
1241         }
1242         ret = install_sighandler(SIGHUP);
1243         if (ret < 0)
1244                 return ret;
1245         ret = select_loop();
1246         if (ret >= 0) /* impossible */
1247                 ret = -E_BUG;
1248         exit_hook(ret);
1249         return ret;
1250 }
1251
1252 static int com_prune(void)
1253 {
1254         int ret;
1255         struct snapshot_list sl;
1256         struct snapshot *victim;
1257         struct disk_space ds;
1258         const char *why;
1259
1260         ret = get_disk_space(".", &ds);
1261         if (ret < 0)
1262                 return ret;
1263         log_disk_space(&ds);
1264         dss_get_snapshot_list(&sl);
1265         why = "outdated";
1266         victim = find_outdated_snapshot(&sl);
1267         if (victim)
1268                 goto rm;
1269         why = "redundant";
1270         victim = find_redundant_snapshot(&sl);
1271         if (victim)
1272                 goto rm;
1273         ret = 0;
1274         goto out;
1275 rm:
1276         if (conf.dry_run_given) {
1277                 dss_msg("%s snapshot %s (interval = %i)\n",
1278                         why, victim->name, victim->interval);
1279                 ret = 0;
1280                 goto out;
1281         }
1282         pre_remove_hook(victim, why);
1283         if (snapshot_removal_status == HS_PRE_RUNNING) {
1284                 ret = wait_for_remove_process();
1285                 if (ret < 0)
1286                         goto out;
1287                 if (snapshot_removal_status != HS_PRE_SUCCESS)
1288                         goto out;
1289         }
1290         ret = exec_rm();
1291         if (ret < 0)
1292                 goto out;
1293         ret = wait_for_remove_process();
1294         if (ret < 0)
1295                 goto out;
1296         if (snapshot_removal_status != HS_SUCCESS)
1297                 goto out;
1298         post_remove_hook();
1299         if (snapshot_removal_status != HS_POST_RUNNING)
1300                 goto out;
1301         ret = wait_for_remove_process();
1302         if (ret < 0)
1303                 goto out;
1304         ret = 1;
1305 out:
1306         free_snapshot_list(&sl);
1307         return ret;
1308 }
1309
1310 static int com_create(void)
1311 {
1312         int ret, status;
1313         char **rsync_argv;
1314
1315         if (conf.dry_run_given) {
1316                 int i;
1317                 char *msg = NULL;
1318                 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1319                 for (i = 0; rsync_argv[i]; i++) {
1320                         char *tmp = msg;
1321                         msg = make_message("%s%s%s", tmp? tmp : "",
1322                                 tmp? " " : "", rsync_argv[i]);
1323                         free(tmp);
1324                 }
1325                 free_rsync_argv(rsync_argv);
1326                 dss_msg("%s\n", msg);
1327                 free(msg);
1328                 return 1;
1329         }
1330         pre_create_hook();
1331         if (create_pid) {
1332                 ret = wait_for_process(create_pid, &status);
1333                 if (ret < 0)
1334                         return ret;
1335                 ret = handle_pre_create_hook_exit(status);
1336                 if (ret <= 0) /* error, or pre-create failed */
1337                         return ret;
1338         }
1339         create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1340         ret = create_snapshot(rsync_argv);
1341         if (ret < 0)
1342                 goto out;
1343         ret = wait_for_process(create_pid, &status);
1344         if (ret < 0)
1345                 goto out;
1346         ret = handle_rsync_exit(status);
1347         if (ret < 0)
1348                 goto out;
1349         post_create_hook();
1350         if (create_pid)
1351                 ret = wait_for_process(create_pid, &status);
1352 out:
1353         free_rsync_argv(rsync_argv);
1354         return ret;
1355 }
1356
1357 static int com_ls(void)
1358 {
1359         int i;
1360         struct snapshot_list sl;
1361         struct snapshot *s;
1362
1363         dss_get_snapshot_list(&sl);
1364         FOR_EACH_SNAPSHOT(s, i, &sl) {
1365                 int64_t d = 0;
1366                 if (s->flags & SS_COMPLETE)
1367                         d = (s->completion_time - s->creation_time) / 60;
1368                 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1369         };
1370         free_snapshot_list(&sl);
1371         return 1;
1372 }
1373
1374 static int setup_signal_handling(void)
1375 {
1376         int ret;
1377
1378         DSS_INFO_LOG("setting up signal handlers\n");
1379         signal_pipe = signal_init(); /* always successful */
1380         ret = install_sighandler(SIGINT);
1381         if (ret < 0)
1382                 return ret;
1383         ret = install_sighandler(SIGTERM);
1384         if (ret < 0)
1385                 return ret;
1386         return install_sighandler(SIGCHLD);
1387 }
1388
1389 /**
1390  * The main function of dss.
1391  *
1392  * \param argc Usual argument count.
1393  * \param argv Usual argument vector.
1394  */
1395 int main(int argc, char **argv)
1396 {
1397         int ret;
1398         struct cmdline_parser_params params = {
1399                 .override = 0,
1400                 .initialize = 1,
1401                 .check_required = 0,
1402                 .check_ambiguity = 0,
1403                 .print_errors = 1
1404         };
1405
1406         cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1407         ret = parse_config_file(0);
1408         if (ret < 0)
1409                 goto out;
1410         if (ret == 0) { /* no config file given */
1411                 /*
1412                  * Parse the command line options again, but this time check
1413                  * that all required options are given.
1414                  */
1415                 params = (struct cmdline_parser_params) {
1416                         .override = 1,
1417                         .initialize = 1,
1418                         .check_required = 1,
1419                         .check_ambiguity = 1,
1420                         .print_errors = 1
1421                 };
1422                 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1423         }
1424         if (conf.daemon_given)
1425                 daemon_init();
1426         ret = change_to_dest_dir();
1427         if (ret < 0)
1428                 goto out;
1429         dump_dss_config("startup");
1430         ret = setup_signal_handling();
1431         if (ret < 0)
1432                 goto out;
1433         ret = call_command_handler();
1434 out:
1435         if (ret < 0)
1436                 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1437         exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1438 }