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 #include "ipc.h"
  37
  38 /** Command line and config file options. */
  39 static struct gengetopt_args_info conf;
  40 /** Non-NULL if we log to a file. */
  41 static FILE *logfile;
  42 /** The read end of the signal pipe */
  43 static int signal_pipe;
  44 /** Process id of current pre-create-hook/rsync/post-create-hook process. */
  45 static pid_t create_pid;
  46 /** Whether the pre-create-hook/rsync/post-create-hook is currently stopped. */
  47 static int create_process_stopped;
  48 /** Process id of current pre-remove/rm/post-remove process. */
  49 static pid_t remove_pid;
  50 /** When the next snapshot is due. */
  51 static int64_t next_snapshot_time;
  52 /** When to try to remove something. */
  53 static struct timeval next_removal_check;
  54 /** Creation time of the snapshot currently being created. */
  55 static int64_t current_snapshot_creation_time;
  56 /** The snapshot currently being removed. */
  57 struct snapshot *snapshot_currently_being_removed;
  58 /** Needed by the post-create hook. */
  59 static char *path_to_last_complete_snapshot;
  60 static char *name_of_reference_snapshot;
  61 /** \sa \ref snap.h for details. */
  62 enum hook_status snapshot_creation_status;
  63 /** \sa \ref snap.h for details. */
  64 enum hook_status snapshot_removal_status;
  65
  66
  67 DEFINE_DSS_ERRLIST;
  68 static const char *hook_status_description[] = {HOOK_STATUS_ARRAY};
  69
  70 /* may be called with ds == NULL. */
  71 static int disk_space_low(struct disk_space *ds)
  72 {
  73         struct disk_space ds_struct;
  74
  75         if (!ds) {
  76                 int ret = get_disk_space(".", &ds_struct);
  77                 if (ret < 0)
  78                         return ret;
  79                 ds = &ds_struct;
  80         }
  81         if (conf.min_free_mb_arg)
  82                 if (ds->free_mb < conf.min_free_mb_arg)
  83                         return 1;
  84         if (conf.min_free_percent_arg)
  85                 if (ds->percent_free < conf.min_free_percent_arg)
  86                         return 1;
  87         if (conf.min_free_percent_inodes_arg)
  88                 if (ds->percent_free_inodes < conf.min_free_percent_inodes_arg)
  89                         return 1;
  90         return 0;
  91 }
  92
  93 static void dump_dss_config(const char *msg)
  94 {
  95         const char dash[] = "-----------------------------";
  96         int ret;
  97         FILE *log = logfile? logfile : stderr;
  98         struct disk_space ds;
  99         int64_t now = get_current_time();
 100
 101         if (conf.loglevel_arg > INFO)
 102                 return;
 103
 104         fprintf(log, "%s <%s config> %s\n", dash, msg, dash);
 105         fprintf(log, "\n*** disk space ***\n\n");
 106         ret = get_disk_space(".", &ds);
 107         if (ret >= 0) {
 108                 DSS_INFO_LOG("disk space low: %s\n", disk_space_low(&ds)?
 109                         "yes" : "no");
 110                 log_disk_space(&ds);
 111         } else
 112                 DSS_ERROR_LOG("can not get free disk space: %s\n",
 113                         dss_strerror(-ret));
 114
 115         /* we continue on errors from get_disk_space */
 116
 117         fprintf(log, "\n*** command line and config file options ***\n\n");
 118         cmdline_parser_dump(log, &conf);
 119         fprintf(log, "\n*** internal state ***\n\n");
 120         fprintf(log,
 121                 "pid: %d\n"
 122                 "logile: %s\n"
 123                 "snapshot_currently_being_removed: %s\n"
 124                 "path_to_last_complete_snapshot: %s\n"
 125                 "reference_snapshot: %s\n"
 126                 "snapshot_creation_status: %s\n"
 127                 "snapshot_removal_status: %s\n"
 128                 ,
 129                 (int) getpid(),
 130                 logfile? conf.logfile_arg : "stderr",
 131                 snapshot_currently_being_removed?
 132                         snapshot_currently_being_removed->name : "(none)",
 133                 path_to_last_complete_snapshot?
 134                         path_to_last_complete_snapshot : "(none)",
 135                 name_of_reference_snapshot?
 136                         name_of_reference_snapshot : "(none)",
 137                 hook_status_description[snapshot_creation_status],
 138                 hook_status_description[snapshot_removal_status]
 139         );
 140         if (create_pid != 0)
 141                 fprintf(log,
 142                         "create_pid: %" PRId32 "\n"
 143                         "create process is %sstopped\n"
 144                         ,
 145                         create_pid,
 146                         create_process_stopped? "" : "not "
 147                 );
 148         if (remove_pid != 0)
 149                 fprintf(log, "remove_pid: %" PRId32 "\n", remove_pid);
 150         if (next_snapshot_time != 0)
 151                 fprintf(log, "next snapshot due in %" PRId64 " seconds\n",
 152                         next_snapshot_time - now);
 153         if (current_snapshot_creation_time != 0)
 154                 fprintf(log, "current_snapshot_creation_time: %"
 155                         PRId64 " (%" PRId64 " seconds ago)\n",
 156                         current_snapshot_creation_time,
 157                         now - current_snapshot_creation_time
 158                 );
 159         if (next_removal_check.tv_sec != 0) {
 160                 fprintf(log, "next removal check: %llu (%llu seconds ago)\n",
 161                         (long long unsigned)next_removal_check.tv_sec,
 162                         now - (long long unsigned)next_removal_check.tv_sec
 163                 );
 164
 165         }
 166         fprintf(log, "%s </%s config> %s\n", dash, msg, dash);
 167 }
 168
 169 /* a litte cpp magic helps to DRY */
 170 #define COMMANDS \
 171         COMMAND(ls) \
 172         COMMAND(create) \
 173         COMMAND(prune) \
 174         COMMAND(run) \
 175         COMMAND(kill) \
 176         COMMAND(reload) \
 177
 178 #define COMMAND(x) static int com_ ##x(void);
 179 COMMANDS
 180 #undef COMMAND
 181 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
 182 static int call_command_handler(void)
 183 {
 184         COMMANDS
 185         DSS_EMERG_LOG("BUG: did not find command handler\n");
 186         return -E_BUG;
 187 }
 188 #undef COMMAND
 189 #undef COMMANDS
 190
 191 /**
 192  * The log function of dss.
 193  *
 194  * \param ll Loglevel.
 195  * \param fml Usual format string.
 196  *
 197  * All DSS_XXX_LOG() macros use this function.
 198  */
 199 __printf_2_3 void dss_log(int ll, const char* fmt,...)
 200 {
 201         va_list argp;
 202         FILE *outfd;
 203         struct tm *tm;
 204         time_t t1;
 205         char str[255] = "";
 206
 207         if (ll < conf.loglevel_arg)
 208                 return;
 209         outfd = logfile? logfile : stderr;
 210         time(&t1);
 211         tm = localtime(&t1);
 212         strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
 213         fprintf(outfd, "%s ", str);
 214         if (conf.loglevel_arg <= INFO)
 215                 fprintf(outfd, "%i: ", ll);
 216         va_start(argp, fmt);
 217         vfprintf(outfd, fmt, argp);
 218         va_end(argp);
 219 }
 220
 221 /**
 222  * Print a message either to stdout or to the log file.
 223  */
 224 static __printf_1_2 void dss_msg(const char* fmt,...)
 225 {
 226         FILE *outfd = conf.daemon_given? logfile : stdout;
 227         va_list argp;
 228         va_start(argp, fmt);
 229         vfprintf(outfd, fmt, argp);
 230         va_end(argp);
 231 }
 232
 233 static char *get_config_file_name(void)
 234 {
 235         char *home, *config_file;
 236
 237         if (conf.config_file_given)
 238                 return dss_strdup(conf.config_file_arg);
 239         home = get_homedir();
 240         config_file = make_message("%s/.dssrc", home);
 241         free(home);
 242         return config_file;
 243 }
 244
 245 static int send_signal(int sig)
 246 {
 247         pid_t pid;
 248         char *config_file = get_config_file_name();
 249         int ret = get_dss_pid(config_file, &pid);
 250
 251         free(config_file);
 252         if (ret < 0)
 253                 return ret;
 254         if (conf.dry_run_given) {
 255                 dss_msg("%d\n", (int)pid);
 256                 return 0;
 257         }
 258         ret = kill(pid, sig);
 259         if (ret < 0)
 260                 return -ERRNO_TO_DSS_ERROR(errno);
 261         return 1;
 262 }
 263
 264 static int com_kill(void)
 265 {
 266         return send_signal(SIGTERM);
 267 }
 268
 269 static int com_reload(void)
 270 {
 271         return send_signal(SIGHUP);
 272 }
 273
 274 static void dss_get_snapshot_list(struct snapshot_list *sl)
 275 {
 276         get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
 277 }
 278
 279 static int64_t compute_next_snapshot_time(void)
 280 {
 281         int64_t x = 0, now = get_current_time(), unit_interval
 282                 = 24 * 3600 * conf.unit_interval_arg, ret;
 283         unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
 284                 num_complete_snapshots = 0;
 285         int i;
 286         struct snapshot *s = NULL;
 287         struct snapshot_list sl;
 288
 289         dss_get_snapshot_list(&sl);
 290         FOR_EACH_SNAPSHOT(s, i, &sl) {
 291                 if (!(s->flags & SS_COMPLETE))
 292                         continue;
 293                 num_complete_snapshots++;
 294                 x += s->completion_time - s->creation_time;
 295         }
 296         assert(x >= 0);
 297
 298         ret = now;
 299         if (num_complete_snapshots == 0)
 300                 goto out;
 301         x /= num_complete_snapshots; /* avg time to create one snapshot */
 302         if (unit_interval < x * wanted) /* oops, no sleep at all */
 303                 goto out;
 304         ret = s->completion_time + unit_interval / wanted - x;
 305 out:
 306         free_snapshot_list(&sl);
 307         return ret;
 308 }
 309
 310 static inline void invalidate_next_snapshot_time(void)
 311 {
 312         next_snapshot_time = 0;
 313 }
 314
 315 static inline int next_snapshot_time_is_valid(void)
 316 {
 317         return next_snapshot_time != 0;
 318 }
 319
 320 static int next_snapshot_is_due(void)
 321 {
 322         int64_t now = get_current_time();
 323
 324         if (!next_snapshot_time_is_valid())
 325                 next_snapshot_time = compute_next_snapshot_time();
 326         if (next_snapshot_time <= now) {
 327                 DSS_DEBUG_LOG("next snapshot: now\n");
 328                 return 1;
 329         }
 330         DSS_DEBUG_LOG("next snapshot due in %" PRId64 " seconds\n",
 331                 next_snapshot_time - now);
 332         return 0;
 333 }
 334
 335 static void pre_create_hook(void)
 336 {
 337         assert(snapshot_creation_status == HS_READY);
 338         /* make sure that the next snapshot time will be recomputed */
 339         invalidate_next_snapshot_time();
 340         DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg);
 341         dss_exec_cmdline_pid(&create_pid, conf.pre_create_hook_arg);
 342         snapshot_creation_status = HS_PRE_RUNNING;
 343 }
 344
 345 static void pre_remove_hook(struct snapshot *s, const char *why)
 346 {
 347         char *cmd;
 348
 349         if (!s)
 350                 return;
 351         DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name);
 352         assert(snapshot_removal_status == HS_READY);
 353         assert(remove_pid == 0);
 354         assert(!snapshot_currently_being_removed);
 355
 356         snapshot_currently_being_removed = dss_malloc(sizeof(struct snapshot));
 357         *snapshot_currently_being_removed = *s;
 358         snapshot_currently_being_removed->name = dss_strdup(s->name);
 359
 360         cmd = make_message("%s %s/%s", conf.pre_remove_hook_arg,
 361                 conf.dest_dir_arg, s->name);
 362         DSS_DEBUG_LOG("executing %s\n", cmd);
 363         dss_exec_cmdline_pid(&remove_pid, cmd);
 364         free(cmd);
 365         snapshot_removal_status = HS_PRE_RUNNING;
 366 }
 367
 368 static int exec_rm(void)
 369 {
 370         struct snapshot *s = snapshot_currently_being_removed;
 371         char *new_name = being_deleted_name(s);
 372         char *argv[4];
 373         int ret;
 374
 375         argv[0] = "rm";
 376         argv[1] = "-rf";
 377         argv[2] = new_name;
 378         argv[3] = NULL;
 379
 380         assert(snapshot_removal_status == HS_PRE_SUCCESS);
 381         assert(remove_pid == 0);
 382
 383         DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
 384         ret = dss_rename(s->name, new_name);
 385         if (ret < 0)
 386                 goto out;
 387         dss_exec(&remove_pid, argv[0], argv);
 388         snapshot_removal_status = HS_RUNNING;
 389 out:
 390         free(new_name);
 391         return ret;
 392 }
 393
 394 static int snapshot_is_being_created(struct snapshot *s)
 395 {
 396         return s->creation_time == current_snapshot_creation_time;
 397 }
 398
 399 static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl)
 400 {
 401         struct snapshot *s;
 402         int i;
 403
 404         DSS_DEBUG_LOG("looking for orphaned snapshots\n");
 405         FOR_EACH_SNAPSHOT(s, i, sl) {
 406                 if (snapshot_is_being_created(s))
 407                         continue;
 408                 /*
 409                  * We know that no rm is currently running, so if s is marked
 410                  * as being deleted, a previously started rm must have failed.
 411                  */
 412                 if (s->flags & SS_BEING_DELETED)
 413                         return s;
 414
 415                 if (s->flags & SS_COMPLETE) /* good snapshot */
 416                         continue;
 417                 /*
 418                  * This snapshot is incomplete and it is not the snapshot
 419                  * currently being created. However, we must not remove it if
 420                  * rsync is about to be restarted. As only the newest snapshot
 421                  * can be restarted, this snapshot is orphaned if it is not the
 422                  * newest snapshot or if we are not about to restart rsync.
 423                  */
 424                 if (get_newest_snapshot(sl) != s)
 425                         return s;
 426                 if (snapshot_creation_status != HS_NEEDS_RESTART)
 427                         return s;
 428         }
 429         /* no orphaned snapshots */
 430         return NULL;
 431 }
 432
 433 static int is_reference_snapshot(struct snapshot *s)
 434 {
 435         if (!name_of_reference_snapshot)
 436                 return 0;
 437         return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
 438 }
 439
 440 /*
 441  * return: 0: no redundant snapshots, 1: rm process started, negative: error
 442  */
 443 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
 444 {
 445         int i, interval;
 446         struct snapshot *s;
 447         unsigned missing = 0;
 448
 449         DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
 450         for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
 451                 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
 452                 unsigned num = sl->interval_count[interval];
 453                 struct snapshot *victim = NULL, *prev = NULL;
 454                 int64_t score = LONG_MAX;
 455
 456                 if (keep >= num)
 457                         missing += keep - num;
 458                 if (keep + missing >= num)
 459                         continue;
 460                 /* redundant snapshot in this interval, pick snapshot with lowest score */
 461                 FOR_EACH_SNAPSHOT(s, i, sl) {
 462                         int64_t this_score;
 463
 464                         if (snapshot_is_being_created(s))
 465                                 continue;
 466                         if (is_reference_snapshot(s))
 467                                 continue;
 468                         if (s->interval > interval) {
 469                                 prev = s;
 470                                 continue;
 471                         }
 472                         if (s->interval < interval)
 473                                 break;
 474                         if (!victim) {
 475                                 victim = s;
 476                                 prev = s;
 477                                 continue;
 478                         }
 479                         assert(prev);
 480                         /* check if s is a better victim */
 481                         this_score = s->creation_time - prev->creation_time;
 482                         assert(this_score >= 0);
 483                         if (this_score < score) {
 484                                 score = this_score;
 485                                 victim = s;
 486                         }
 487                         prev = s;
 488                 }
 489                 assert(victim);
 490                 return victim;
 491         }
 492         return NULL;
 493 }
 494
 495 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
 496 {
 497         int i;
 498         struct snapshot *s;
 499
 500         DSS_DEBUG_LOG("looking for snapshots belonging to intervals >= %d\n",
 501                 conf.num_intervals_arg);
 502         FOR_EACH_SNAPSHOT(s, i, sl) {
 503                 if (snapshot_is_being_created(s))
 504                         continue;
 505                 if (is_reference_snapshot(s))
 506                         continue;
 507                 if (s->interval < conf.num_intervals_arg)
 508                         continue;
 509                 return s;
 510         }
 511         return NULL;
 512 }
 513
 514 struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
 515 {
 516         int i;
 517         struct snapshot *s;
 518         FOR_EACH_SNAPSHOT(s, i, sl) {
 519                 if (snapshot_is_being_created(s))
 520                         continue;
 521                 if (is_reference_snapshot(s))
 522                         continue;
 523                 DSS_INFO_LOG("oldest removable snapshot: %s\n", s->name);
 524                 return s;
 525         }
 526         return NULL;
 527 }
 528
 529 static int rename_incomplete_snapshot(int64_t start)
 530 {
 531         char *old_name;
 532         int ret;
 533
 534         free(path_to_last_complete_snapshot);
 535         ret = complete_name(start, get_current_time(),
 536                 &path_to_last_complete_snapshot);
 537         if (ret < 0)
 538                 return ret;
 539         old_name = incomplete_name(start);
 540         ret = dss_rename(old_name, path_to_last_complete_snapshot);
 541         if (ret >= 0)
 542                 DSS_NOTICE_LOG("%s -> %s\n", old_name,
 543                         path_to_last_complete_snapshot);
 544         free(old_name);
 545         return ret;
 546 }
 547
 548 static int try_to_free_disk_space(void)
 549 {
 550         int ret;
 551         struct snapshot_list sl;
 552         struct snapshot *victim;
 553         struct timeval now;
 554         const char *why;
 555         int low_disk_space;
 556
 557         ret = disk_space_low(NULL);
 558         if (ret < 0)
 559                 return ret;
 560         low_disk_space = ret;
 561         gettimeofday(&now, NULL);
 562         if (tv_diff(&next_removal_check, &now, NULL) > 0)
 563                 return 0;
 564         if (!low_disk_space) {
 565                 if (conf.keep_redundant_given)
 566                         return 0;
 567                 if (snapshot_creation_status != HS_READY)
 568                         return 0;
 569                 if (next_snapshot_is_due())
 570                         return 0;
 571         }
 572         dss_get_snapshot_list(&sl);
 573         ret = 0;
 574         if (!low_disk_space && sl.num_snapshots <= 1)
 575                 goto out;
 576         why = "outdated";
 577         victim = find_outdated_snapshot(&sl);
 578         if (victim)
 579                 goto remove;
 580         why = "redundant";
 581         victim = find_redundant_snapshot(&sl);
 582         if (victim)
 583                 goto remove;
 584         /* try harder only if disk space is low */
 585         if (!low_disk_space)
 586                 goto out;
 587         why = "orphaned";
 588         victim = find_orphaned_snapshot(&sl);
 589         if (victim)
 590                 goto remove;
 591         DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
 592         victim = find_oldest_removable_snapshot(&sl);
 593         if (victim)
 594                 goto remove;
 595         DSS_CRIT_LOG("uhuhu: disk space low and nothing to remove\n");
 596         ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
 597         goto out;
 598 remove:
 599         pre_remove_hook(victim, why);
 600 out:
 601         free_snapshot_list(&sl);
 602         return ret;
 603 }
 604
 605 static void post_create_hook(void)
 606 {
 607         char *cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
 608                 conf.dest_dir_arg, path_to_last_complete_snapshot);
 609         DSS_NOTICE_LOG("executing %s\n", cmd);
 610         dss_exec_cmdline_pid(&create_pid, cmd);
 611         free(cmd);
 612         snapshot_creation_status = HS_POST_RUNNING;
 613 }
 614
 615 static void post_remove_hook(void)
 616 {
 617         char *cmd;
 618         struct snapshot *s = snapshot_currently_being_removed;
 619
 620         assert(s);
 621
 622         cmd = make_message("%s %s/%s", conf.post_remove_hook_arg,
 623                 conf.dest_dir_arg, s->name);
 624         DSS_NOTICE_LOG("executing %s\n", cmd);
 625         dss_exec_cmdline_pid(&remove_pid, cmd);
 626         free(cmd);
 627         snapshot_removal_status = HS_POST_RUNNING;
 628 }
 629
 630 static void dss_kill(pid_t pid, int sig, const char *msg)
 631 {
 632         const char *signame, *process_name;
 633
 634         if (pid == 0)
 635                 return;
 636         switch (sig) {
 637         case SIGTERM: signame = "TERM"; break;
 638         case SIGSTOP: signame = "STOP"; break;
 639         case SIGCONT: signame = "CONT"; break;
 640         default: signame = "????";
 641         }
 642
 643         if (pid == create_pid)
 644                 process_name = "create";
 645         else if (pid == remove_pid)
 646                 process_name = "remove";
 647         else process_name = "??????";
 648
 649         if (msg)
 650                 DSS_INFO_LOG("%s\n", msg);
 651         DSS_DEBUG_LOG("sending signal %d (%s) to pid %d (%s process)\n",
 652                 sig, signame, (int)pid, process_name);
 653         if (kill(pid, sig) >= 0)
 654                 return;
 655         DSS_INFO_LOG("failed to send signal %d (%s) to pid %d (%s process)\n",
 656                 sig, signame, (int)pid, process_name);
 657 }
 658
 659 static void stop_create_process(void)
 660 {
 661         if (create_process_stopped)
 662                 return;
 663         dss_kill(create_pid, SIGSTOP, "suspending create process");
 664         create_process_stopped = 1;
 665 }
 666
 667 static void restart_create_process(void)
 668 {
 669         if (!create_process_stopped)
 670                 return;
 671         dss_kill(create_pid, SIGCONT, "resuming create process");
 672         create_process_stopped = 0;
 673 }
 674
 675 /**
 676  * Print a log message about the exit status of a child.
 677  */
 678 static void log_termination_msg(pid_t pid, int status)
 679 {
 680         if (WIFEXITED(status))
 681                 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
 682                         WEXITSTATUS(status));
 683         else if (WIFSIGNALED(status))
 684                 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
 685                         WTERMSIG(status));
 686         else
 687                 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
 688 }
 689
 690 static int wait_for_process(pid_t pid, int *status)
 691 {
 692         int ret;
 693
 694         DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
 695         for (;;) {
 696                 fd_set rfds;
 697
 698                 FD_ZERO(&rfds);
 699                 FD_SET(signal_pipe, &rfds);
 700                 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
 701                 if (ret < 0)
 702                         break;
 703                 ret = next_signal();
 704                 if (!ret)
 705                         continue;
 706                 if (ret == SIGCHLD) {
 707                         ret = waitpid(pid, status, 0);
 708                         if (ret >= 0)
 709                                 break;
 710                         if (errno != EINTR) { /* error */
 711                                 ret = -ERRNO_TO_DSS_ERROR(errno);
 712                                 break;
 713                         }
 714                 }
 715                 /* SIGINT or SIGTERM */
 716                 dss_kill(pid, SIGTERM, "killing child process");
 717         }
 718         if (ret < 0)
 719                 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
 720         else
 721                 log_termination_msg(pid, *status);
 722         return ret;
 723 }
 724
 725 static void handle_pre_remove_exit(int status)
 726 {
 727         if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 728                 snapshot_removal_status = HS_READY;
 729                 gettimeofday(&next_removal_check, NULL);
 730                 next_removal_check.tv_sec += 60;
 731                 return;
 732         }
 733         snapshot_removal_status = HS_PRE_SUCCESS;
 734 }
 735
 736 static int handle_rm_exit(int status)
 737 {
 738         if (!WIFEXITED(status)) {
 739                 snapshot_removal_status = HS_READY;
 740                 return -E_INVOLUNTARY_EXIT;
 741         }
 742         if (WEXITSTATUS(status)) {
 743                 snapshot_removal_status = HS_READY;
 744                 return -E_BAD_EXIT_CODE;
 745         }
 746         snapshot_removal_status = HS_SUCCESS;
 747         return 1;
 748 }
 749
 750 static void handle_post_remove_exit(void)
 751 {
 752         snapshot_removal_status = HS_READY;
 753 }
 754
 755 static int handle_remove_exit(int status)
 756 {
 757         int ret;
 758         struct snapshot *s = snapshot_currently_being_removed;
 759
 760         assert(s);
 761         switch (snapshot_removal_status) {
 762         case HS_PRE_RUNNING:
 763                 handle_pre_remove_exit(status);
 764                 ret = 1;
 765                 break;
 766         case HS_RUNNING:
 767                 ret = handle_rm_exit(status);
 768                 break;
 769         case HS_POST_RUNNING:
 770                 handle_post_remove_exit();
 771                 ret = 1;
 772                 break;
 773         default:
 774                 ret = -E_BUG;
 775         }
 776         if (snapshot_removal_status == HS_READY) {
 777                 free(s->name);
 778                 free(s);
 779                 snapshot_currently_being_removed = NULL;
 780         }
 781         remove_pid = 0;
 782         return ret;
 783 }
 784
 785 static int wait_for_remove_process(void)
 786 {
 787         int status, ret;
 788
 789         assert(remove_pid);
 790         assert(
 791                 snapshot_removal_status == HS_PRE_RUNNING ||
 792                 snapshot_removal_status == HS_RUNNING ||
 793                 snapshot_removal_status == HS_POST_RUNNING
 794         );
 795         ret = wait_for_process(remove_pid, &status);
 796         if (ret < 0)
 797                 return ret;
 798         return handle_remove_exit(status);
 799 }
 800
 801 static int handle_rsync_exit(int status)
 802 {
 803         int es, ret;
 804
 805         if (!WIFEXITED(status)) {
 806                 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)create_pid);
 807                 ret = -E_INVOLUNTARY_EXIT;
 808                 snapshot_creation_status = HS_READY;
 809                 goto out;
 810         }
 811         es = WEXITSTATUS(status);
 812         /*
 813          * Restart rsync on non-fatal errors:
 814          * 12: Error in rsync protocol data stream
 815          * 13: Errors with program diagnostics
 816          */
 817         if (es == 12 || es == 13) {
 818                 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
 819                         (int)create_pid, es);
 820                 snapshot_creation_status = HS_NEEDS_RESTART;
 821                 next_snapshot_time = get_current_time() + 60;
 822                 ret = 1;
 823                 goto out;
 824         }
 825         if (es != 0 && es != 23 && es != 24) {
 826                 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)create_pid, es);
 827                 ret = -E_BAD_EXIT_CODE;
 828                 snapshot_creation_status = HS_READY;
 829                 goto out;
 830         }
 831         ret = rename_incomplete_snapshot(current_snapshot_creation_time);
 832         if (ret < 0)
 833                 goto out;
 834         snapshot_creation_status = HS_SUCCESS;
 835         free(name_of_reference_snapshot);
 836         name_of_reference_snapshot = NULL;
 837 out:
 838         create_process_stopped = 0;
 839         return ret;
 840 }
 841
 842 static int handle_pre_create_hook_exit(int status)
 843 {
 844         int es, ret;
 845         static int warn_count;
 846
 847         if (!WIFEXITED(status)) {
 848                 snapshot_creation_status = HS_READY;
 849                 ret = -E_INVOLUNTARY_EXIT;
 850                 goto out;
 851         }
 852         es = WEXITSTATUS(status);
 853         if (es) {
 854                 if (!warn_count--) {
 855                         DSS_NOTICE_LOG("pre_create_hook %s returned %d\n",
 856                                 conf.pre_create_hook_arg, es);
 857                         DSS_NOTICE_LOG("deferring snapshot creation...\n");
 858                         warn_count = 60; /* warn only once per hour */
 859                 }
 860                 next_snapshot_time = get_current_time() + 60;
 861                 snapshot_creation_status = HS_READY;
 862                 ret = 0;
 863                 goto out;
 864         }
 865         warn_count = 0;
 866         snapshot_creation_status = HS_PRE_SUCCESS;
 867         ret = 1;
 868 out:
 869         return ret;
 870 }
 871
 872 static int handle_sigchld(void)
 873 {
 874         pid_t pid;
 875         int status, ret = reap_child(&pid, &status);
 876
 877         if (ret <= 0)
 878                 return ret;
 879
 880         if (pid == create_pid) {
 881                 switch (snapshot_creation_status) {
 882                 case HS_PRE_RUNNING:
 883                         ret = handle_pre_create_hook_exit(status);
 884                         break;
 885                 case HS_RUNNING:
 886                         ret = handle_rsync_exit(status);
 887                         break;
 888                 case HS_POST_RUNNING:
 889                         snapshot_creation_status = HS_READY;
 890                         ret = 1;
 891                         break;
 892                 default:
 893                         DSS_EMERG_LOG("BUG: create can't die in status %d\n",
 894                                 snapshot_creation_status);
 895                         return -E_BUG;
 896                 }
 897                 create_pid = 0;
 898                 return ret;
 899         }
 900         if (pid == remove_pid) {
 901                 ret = handle_remove_exit(status);
 902                 if (ret < 0)
 903                         return ret;
 904                 return ret;
 905         }
 906         DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
 907         return -E_BUG;
 908 }
 909
 910 static int check_config(void)
 911 {
 912         if (conf.unit_interval_arg <= 0) {
 913                 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
 914                 return -E_INVALID_NUMBER;
 915         }
 916         DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
 917         if (conf.num_intervals_arg <= 0) {
 918                 DSS_ERROR_LOG("bad number of intervals  %i\n", conf.num_intervals_arg);
 919                 return -E_INVALID_NUMBER;
 920         }
 921         DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
 922         return 1;
 923 }
 924
 925 /*
 926  * Returns < 0 on errors, 0 if no config file is given and > 0 if the config
 927  * file was read successfully.
 928  */
 929 static int parse_config_file(int override)
 930 {
 931         int ret, config_file_exists;
 932         char *config_file = get_config_file_name();
 933         struct stat statbuf;
 934         char *old_logfile_arg = NULL;
 935         int old_daemon_given = 0;
 936
 937         if (override) { /* SIGHUP */
 938                 if (conf.logfile_given)
 939                         old_logfile_arg = dss_strdup(conf.logfile_arg);
 940                 old_daemon_given = conf.daemon_given;
 941         }
 942
 943         config_file_exists = !stat(config_file, &statbuf);
 944         if (!config_file_exists && conf.config_file_given) {
 945                 ret = -ERRNO_TO_DSS_ERROR(errno);
 946                 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
 947                 goto out;
 948         }
 949         if (config_file_exists) {
 950                 struct cmdline_parser_params params;
 951                 params.override = override;
 952                 params.initialize = 0;
 953                 params.check_required = 1;
 954                 params.check_ambiguity = 0;
 955                 params.print_errors = 1;
 956                 if (override) { /* invalidate all rsync options */
 957                         int i;
 958
 959                         for (i = 0; i < conf.rsync_option_given; i++) {
 960                                 free(conf.rsync_option_arg[i]);
 961                                 conf.rsync_option_arg[i] = NULL;
 962                         }
 963                         conf.rsync_option_given = 0;
 964                 }
 965                 cmdline_parser_config_file(config_file, &conf, &params);
 966         }
 967         ret = check_config();
 968         if (ret < 0)
 969                 goto out;
 970         if (override) {
 971                 /* don't change daemon mode on SIGHUP */
 972                 conf.daemon_given = old_daemon_given;
 973                 close_log(logfile);
 974                 logfile = NULL;
 975                 if (conf.logfile_given)
 976                         free(old_logfile_arg);
 977                 else if (conf.daemon_given) { /* re-use old logfile */
 978                         conf.logfile_arg = old_logfile_arg;
 979                         conf.logfile_given = 1;
 980                 }
 981         }
 982         if (conf.logfile_given && conf.run_given && conf.daemon_given) {
 983                 logfile = open_log(conf.logfile_arg);
 984                 log_welcome(conf.loglevel_arg);
 985         }
 986         DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
 987         ret = config_file_exists;
 988 out:
 989         free(config_file);
 990         if (ret < 0)
 991                 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
 992         return ret;
 993 }
 994
 995 static int change_to_dest_dir(void)
 996 {
 997         DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
 998         return dss_chdir(conf.dest_dir_arg);
 999 }
1000
1001 static int handle_sighup(void)
1002 {
1003         int ret;
1004
1005         DSS_NOTICE_LOG("SIGHUP, re-reading config\n");
1006         dump_dss_config("old");
1007         ret = parse_config_file(1);
1008         if (ret < 0)
1009                 return ret;
1010         dump_dss_config("reloaded");
1011         invalidate_next_snapshot_time();
1012         return change_to_dest_dir();
1013 }
1014
1015 static int handle_signal(void)
1016 {
1017         int sig, ret = next_signal();
1018
1019         if (ret <= 0)
1020                 goto out;
1021         sig = ret;
1022         switch (sig) {
1023         case SIGINT:
1024         case SIGTERM:
1025                 restart_create_process();
1026                 dss_kill(create_pid, SIGTERM, NULL);
1027                 dss_kill(remove_pid, SIGTERM, NULL);
1028                 ret = -E_SIGNAL;
1029                 break;
1030         case SIGHUP:
1031                 ret = handle_sighup();
1032                 break;
1033         case SIGCHLD:
1034                 ret = handle_sigchld();
1035                 break;
1036         }
1037 out:
1038         if (ret < 0)
1039                 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
1040         return ret;
1041 }
1042
1043 /*
1044  * We can not use rsync locally if the local user is different from the remote
1045  * user or if the src dir is not on the local host (or both).
1046  */
1047 static int use_rsync_locally(char *logname)
1048 {
1049         char *h = conf.remote_host_arg;
1050
1051         if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
1052                 return 0;
1053         if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
1054                 return 0;
1055         return 1;
1056 }
1057
1058 static int rename_resume_snap(int64_t creation_time)
1059 {
1060         struct snapshot_list sl;
1061         struct snapshot *s = NULL;
1062         char *new_name = incomplete_name(creation_time);
1063         int ret;
1064         const char *why;
1065
1066         sl.num_snapshots = 0;
1067
1068         ret = 0;
1069         if (conf.no_resume_given)
1070                 goto out;
1071         dss_get_snapshot_list(&sl);
1072         /*
1073          * Snapshot recycling: We first look at the newest snapshot. If this
1074          * snapshot happens to be incomplete, the last rsync process was
1075          * aborted and we reuse this one. Otherwise we look at snapshots which
1076          * could be removed (outdated and redundant snapshots) as candidates
1077          * for recycling. If no outdated/redundant snapshot exists, we check if
1078          * there is an orphaned snapshot, which likely is useless anyway.
1079          *
1080          * Only if no existing snapshot is suitable for recycling, we bite the
1081          * bullet and create a new one.
1082          */
1083         s = get_newest_snapshot(&sl);
1084         if (!s) /* no snapshots at all */
1085                 goto out;
1086         /* re-use last snapshot if it is incomplete */
1087         why = "aborted";
1088         if ((s->flags & SS_COMPLETE) == 0)
1089                 goto out;
1090         why = "outdated";
1091         s = find_outdated_snapshot(&sl);
1092         if (s)
1093                 goto out;
1094         why = "redundant";
1095         s = find_redundant_snapshot(&sl);
1096         if (s)
1097                 goto out;
1098         why = "orphaned";
1099         s = find_orphaned_snapshot(&sl);
1100 out:
1101         if (s) {
1102                 DSS_INFO_LOG("reusing %s snapshot %s\n", why, s->name);
1103                 ret = dss_rename(s->name, new_name);
1104         }
1105         if (ret >= 0)
1106                 DSS_NOTICE_LOG("creating new snapshot %s\n", new_name);
1107         free(new_name);
1108         free_snapshot_list(&sl);
1109         return ret;
1110 }
1111
1112 static void create_rsync_argv(char ***argv, int64_t *num)
1113 {
1114         char *logname;
1115         int i = 0, j;
1116         struct snapshot_list sl;
1117
1118         dss_get_snapshot_list(&sl);
1119         assert(!name_of_reference_snapshot);
1120         name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
1121         free_snapshot_list(&sl);
1122
1123         *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
1124         (*argv)[i++] = dss_strdup("rsync");
1125         (*argv)[i++] = dss_strdup("-aq");
1126         (*argv)[i++] = dss_strdup("--delete");
1127         for (j = 0; j < conf.rsync_option_given; j++)
1128                 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
1129         if (name_of_reference_snapshot) {
1130                 DSS_INFO_LOG("using %s as reference\n", name_of_reference_snapshot);
1131                 (*argv)[i++] = make_message("--link-dest=../%s",
1132                         name_of_reference_snapshot);
1133         } else
1134                 DSS_INFO_LOG("no suitable reference snapshot found\n");
1135         logname = dss_logname();
1136         if (use_rsync_locally(logname))
1137                 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
1138         else
1139                 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
1140                         conf.remote_user_arg : logname,
1141                         conf.remote_host_arg, conf.source_dir_arg);
1142         free(logname);
1143         *num = get_current_time();
1144         (*argv)[i++] = incomplete_name(*num);
1145         (*argv)[i++] = NULL;
1146         for (j = 0; j < i; j++)
1147                 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
1148 }
1149
1150 static void free_rsync_argv(char **argv)
1151 {
1152         int i;
1153
1154         if (!argv)
1155                 return;
1156         for (i = 0; argv[i]; i++)
1157                 free(argv[i]);
1158         free(argv);
1159 }
1160
1161 static int create_snapshot(char **argv)
1162 {
1163         int ret;
1164
1165         ret = rename_resume_snap(current_snapshot_creation_time);
1166         if (ret < 0)
1167                 return ret;
1168         dss_exec(&create_pid, argv[0], argv);
1169         snapshot_creation_status = HS_RUNNING;
1170         return ret;
1171 }
1172
1173 static int select_loop(void)
1174 {
1175         int ret;
1176         /* check every 60 seconds for free disk space */
1177         struct timeval tv;
1178         char **rsync_argv = NULL;
1179
1180         for (;;) {
1181                 fd_set rfds;
1182                 struct timeval *tvp;
1183
1184                 if (remove_pid)
1185                         tvp = NULL; /* sleep until rm hook/process dies */
1186                 else { /* sleep one minute */
1187                         tv.tv_sec = 60;
1188                         tv.tv_usec = 0;
1189                         tvp = &tv;
1190                 }
1191                 FD_ZERO(&rfds);
1192                 FD_SET(signal_pipe, &rfds);
1193                 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1194                 if (ret < 0)
1195                         goto out;
1196                 if (FD_ISSET(signal_pipe, &rfds)) {
1197                         ret = handle_signal();
1198                         if (ret < 0)
1199                                 goto out;
1200                 }
1201                 if (remove_pid)
1202                         continue;
1203                 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1204                         ret = exec_rm();
1205                         if (ret < 0)
1206                                 goto out;
1207                         continue;
1208                 }
1209                 if (snapshot_removal_status == HS_SUCCESS) {
1210                         post_remove_hook();
1211                         continue;
1212                 }
1213                 ret = try_to_free_disk_space();
1214                 if (ret < 0)
1215                         goto out;
1216                 if (snapshot_removal_status != HS_READY) {
1217                         stop_create_process();
1218                         continue;
1219                 }
1220                 restart_create_process();
1221                 switch (snapshot_creation_status) {
1222                 case HS_READY:
1223                         if (!next_snapshot_is_due())
1224                                 continue;
1225                         pre_create_hook();
1226                         continue;
1227                 case HS_PRE_RUNNING:
1228                 case HS_RUNNING:
1229                 case HS_POST_RUNNING:
1230                         continue;
1231                 case HS_PRE_SUCCESS:
1232                         if (!name_of_reference_snapshot) {
1233                                 free_rsync_argv(rsync_argv);
1234                                 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1235                         }
1236                         ret = create_snapshot(rsync_argv);
1237                         if (ret < 0)
1238                                 goto out;
1239                         continue;
1240                 case HS_NEEDS_RESTART:
1241                         if (!next_snapshot_is_due())
1242                                 continue;
1243                         ret = create_snapshot(rsync_argv);
1244                         if (ret < 0)
1245                                 goto out;
1246                         continue;
1247                 case HS_SUCCESS:
1248                         post_create_hook();
1249                         continue;
1250                 }
1251         }
1252 out:
1253         return ret;
1254 }
1255
1256 static void exit_hook(int exit_code)
1257 {
1258         char *argv[3];
1259         pid_t pid;
1260
1261         argv[0] = conf.exit_hook_arg;
1262         argv[1] = dss_strerror(-exit_code);
1263         argv[2] = NULL;
1264
1265         DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
1266         dss_exec(&pid, conf.exit_hook_arg, argv);
1267 }
1268
1269 static void lock_dss_or_die(void)
1270 {
1271         char *config_file = get_config_file_name();
1272         int ret = lock_dss(config_file);
1273
1274         free(config_file);
1275         if (ret < 0) {
1276                 DSS_EMERG_LOG("failed to lock: %s\n", dss_strerror(-ret));
1277                 exit(EXIT_FAILURE);
1278         }
1279 }
1280
1281 static int com_run(void)
1282 {
1283         int ret;
1284
1285         lock_dss_or_die();
1286         if (conf.dry_run_given) {
1287                 DSS_ERROR_LOG("dry_run not supported by this command\n");
1288                 return -E_SYNTAX;
1289         }
1290         ret = install_sighandler(SIGHUP);
1291         if (ret < 0)
1292                 return ret;
1293         ret = select_loop();
1294         if (ret >= 0) /* impossible */
1295                 ret = -E_BUG;
1296         exit_hook(ret);
1297         return ret;
1298 }
1299
1300 static int com_prune(void)
1301 {
1302         int ret;
1303         struct snapshot_list sl;
1304         struct snapshot *victim;
1305         struct disk_space ds;
1306         const char *why;
1307
1308         lock_dss_or_die();
1309         ret = get_disk_space(".", &ds);
1310         if (ret < 0)
1311                 return ret;
1312         log_disk_space(&ds);
1313         dss_get_snapshot_list(&sl);
1314         why = "outdated";
1315         victim = find_outdated_snapshot(&sl);
1316         if (victim)
1317                 goto rm;
1318         why = "redundant";
1319         victim = find_redundant_snapshot(&sl);
1320         if (victim)
1321                 goto rm;
1322         ret = 0;
1323         goto out;
1324 rm:
1325         if (conf.dry_run_given) {
1326                 dss_msg("%s snapshot %s (interval = %i)\n",
1327                         why, victim->name, victim->interval);
1328                 ret = 0;
1329                 goto out;
1330         }
1331         pre_remove_hook(victim, why);
1332         if (snapshot_removal_status == HS_PRE_RUNNING) {
1333                 ret = wait_for_remove_process();
1334                 if (ret < 0)
1335                         goto out;
1336                 if (snapshot_removal_status != HS_PRE_SUCCESS)
1337                         goto out;
1338         }
1339         ret = exec_rm();
1340         if (ret < 0)
1341                 goto out;
1342         ret = wait_for_remove_process();
1343         if (ret < 0)
1344                 goto out;
1345         if (snapshot_removal_status != HS_SUCCESS)
1346                 goto out;
1347         post_remove_hook();
1348         if (snapshot_removal_status != HS_POST_RUNNING)
1349                 goto out;
1350         ret = wait_for_remove_process();
1351         if (ret < 0)
1352                 goto out;
1353         ret = 1;
1354 out:
1355         free_snapshot_list(&sl);
1356         return ret;
1357 }
1358
1359 static int com_create(void)
1360 {
1361         int ret, status;
1362         char **rsync_argv;
1363
1364         lock_dss_or_die();
1365         if (conf.dry_run_given) {
1366                 int i;
1367                 char *msg = NULL;
1368                 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1369                 for (i = 0; rsync_argv[i]; i++) {
1370                         char *tmp = msg;
1371                         msg = make_message("%s%s%s", tmp? tmp : "",
1372                                 tmp? " " : "", rsync_argv[i]);
1373                         free(tmp);
1374                 }
1375                 free_rsync_argv(rsync_argv);
1376                 dss_msg("%s\n", msg);
1377                 free(msg);
1378                 return 1;
1379         }
1380         pre_create_hook();
1381         if (create_pid) {
1382                 ret = wait_for_process(create_pid, &status);
1383                 if (ret < 0)
1384                         return ret;
1385                 ret = handle_pre_create_hook_exit(status);
1386                 if (ret <= 0) /* error, or pre-create failed */
1387                         return ret;
1388         }
1389         create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1390         ret = create_snapshot(rsync_argv);
1391         if (ret < 0)
1392                 goto out;
1393         ret = wait_for_process(create_pid, &status);
1394         if (ret < 0)
1395                 goto out;
1396         ret = handle_rsync_exit(status);
1397         if (ret < 0)
1398                 goto out;
1399         post_create_hook();
1400         if (create_pid)
1401                 ret = wait_for_process(create_pid, &status);
1402 out:
1403         free_rsync_argv(rsync_argv);
1404         return ret;
1405 }
1406
1407 static int com_ls(void)
1408 {
1409         int i;
1410         struct snapshot_list sl;
1411         struct snapshot *s;
1412
1413         dss_get_snapshot_list(&sl);
1414         FOR_EACH_SNAPSHOT(s, i, &sl) {
1415                 int64_t d = 0;
1416                 if (s->flags & SS_COMPLETE)
1417                         d = (s->completion_time - s->creation_time) / 60;
1418                 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1419         };
1420         free_snapshot_list(&sl);
1421         return 1;
1422 }
1423
1424 static int setup_signal_handling(void)
1425 {
1426         int ret;
1427
1428         DSS_INFO_LOG("setting up signal handlers\n");
1429         signal_pipe = signal_init(); /* always successful */
1430         ret = install_sighandler(SIGINT);
1431         if (ret < 0)
1432                 return ret;
1433         ret = install_sighandler(SIGTERM);
1434         if (ret < 0)
1435                 return ret;
1436         return install_sighandler(SIGCHLD);
1437 }
1438
1439 /**
1440  * The main function of dss.
1441  *
1442  * \param argc Usual argument count.
1443  * \param argv Usual argument vector.
1444  */
1445 int main(int argc, char **argv)
1446 {
1447         int ret;
1448         struct cmdline_parser_params params;
1449
1450         params.override = 0;
1451         params.initialize = 1;
1452         params.check_required = 0;
1453         params.check_ambiguity = 0;
1454         params.print_errors = 1;
1455
1456         cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1457         ret = parse_config_file(0);
1458         if (ret < 0)
1459                 goto out;
1460         if (ret == 0) { /* no config file given */
1461                 /*
1462                  * Parse the command line options again, but this time check
1463                  * that all required options are given.
1464                  */
1465                 struct cmdline_parser_params params;
1466                 params.override = 1;
1467                 params.initialize = 1;
1468                 params.check_required = 1;
1469                 params.check_ambiguity = 1;
1470                 params.print_errors = 1;
1471                 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1472         }
1473         if (conf.daemon_given)
1474                 daemon_init();
1475         ret = change_to_dest_dir();
1476         if (ret < 0)
1477                 goto out;
1478         dump_dss_config("startup");
1479         ret = setup_signal_handling();
1480         if (ret < 0)
1481                 goto out;
1482         ret = call_command_handler();
1483 out:
1484         if (ret < 0)
1485                 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1486         exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1487 }