src/core/store.c

   1 /*
   2  * SysDB - src/core/store.c
   3  * Copyright (C) 2012-2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #if HAVE_CONFIG_H
  29 #       include "config.h"
  30 #endif /* HAVE_CONFIG_H */
  31
  32 #include "sysdb.h"
  33 #include "core/store-private.h"
  34 #include "core/plugin.h"
  35 #include "utils/error.h"
  36 #include "utils/llist.h"
  37
  38 #include <assert.h>
  39
  40 #include <errno.h>
  41
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45
  46 #include <pthread.h>
  47
  48 /*
  49  * private variables
  50  */
  51
  52 static sdb_llist_t *host_list = NULL;
  53 static pthread_rwlock_t host_lock = PTHREAD_RWLOCK_INITIALIZER;
  54
  55 /*
  56  * private types
  57  */
  58
  59 static sdb_type_t sdb_host_type;
  60 static sdb_type_t sdb_service_type;
  61 static sdb_type_t sdb_attribute_type;
  62
  63 static int
  64 store_obj_init(sdb_object_t *obj, va_list ap)
  65 {
  66         sdb_store_obj_t *sobj = STORE_OBJ(obj);
  67
  68         sobj->type = va_arg(ap, int);
  69
  70         sobj->last_update = va_arg(ap, sdb_time_t);
  71         sobj->interval = 0;
  72         sobj->backends = NULL;
  73         sobj->backends_num = 0;
  74         sobj->parent = NULL;
  75         return 0;
  76 } /* store_obj_init */
  77
  78 static void
  79 store_obj_destroy(sdb_object_t *obj)
  80 {
  81         sdb_store_obj_t *sobj = STORE_OBJ(obj);
  82         size_t i;
  83
  84         for (i = 0; i < sobj->backends_num; ++i)
  85                 free(sobj->backends[i]);
  86         free(sobj->backends);
  87         sobj->backends = NULL;
  88         sobj->backends_num = 0;
  89
  90         if (sobj->parent)
  91                 sdb_object_deref(SDB_OBJ(sobj->parent));
  92 } /* store_obj_destroy */
  93
  94 static int
  95 sdb_host_init(sdb_object_t *obj, va_list ap)
  96 {
  97         sdb_host_t *sobj = HOST(obj);
  98         int ret;
  99
 100         /* this will consume the first argument (type) of ap */
 101         ret = store_obj_init(obj, ap);
 102         if (ret)
 103                 return ret;
 104
 105         sobj->services = sdb_llist_create();
 106         if (! sobj->services)
 107                 return -1;
 108         sobj->attributes = sdb_llist_create();
 109         if (! sobj->attributes)
 110                 return -1;
 111         return 0;
 112 } /* sdb_host_init */
 113
 114 static void
 115 sdb_host_destroy(sdb_object_t *obj)
 116 {
 117         sdb_host_t *sobj = HOST(obj);
 118         assert(obj);
 119
 120         store_obj_destroy(obj);
 121
 122         if (sobj->services)
 123                 sdb_llist_destroy(sobj->services);
 124         if (sobj->attributes)
 125                 sdb_llist_destroy(sobj->attributes);
 126 } /* sdb_host_destroy */
 127
 128 static int
 129 sdb_service_init(sdb_object_t *obj, va_list ap)
 130 {
 131         sdb_service_t *sobj = SVC(obj);
 132         int ret;
 133
 134         /* this will consume the first argument (type) of ap */
 135         ret = store_obj_init(obj, ap);
 136         if (ret)
 137                 return ret;
 138
 139         sobj->attributes = sdb_llist_create();
 140         if (! sobj->attributes)
 141                 return -1;
 142         return 0;
 143 } /* sdb_service_init */
 144
 145 static void
 146 sdb_service_destroy(sdb_object_t *obj)
 147 {
 148         sdb_service_t *sobj = SVC(obj);
 149         assert(obj);
 150
 151         store_obj_destroy(obj);
 152
 153         if (sobj->attributes)
 154                 sdb_llist_destroy(sobj->attributes);
 155 } /* sdb_service_destroy */
 156
 157 static int
 158 sdb_attr_init(sdb_object_t *obj, va_list ap)
 159 {
 160         const sdb_data_t *value;
 161         int ret;
 162
 163         /* this will consume the first two arguments
 164          * (type and last_update) of ap */
 165         ret = store_obj_init(obj, ap);
 166         if (ret)
 167                 return ret;
 168         value = va_arg(ap, const sdb_data_t *);
 169
 170         if (value)
 171                 if (sdb_data_copy(&ATTR(obj)->value, value))
 172                         return -1;
 173         return 0;
 174 } /* sdb_attr_init */
 175
 176 static void
 177 sdb_attr_destroy(sdb_object_t *obj)
 178 {
 179         assert(obj);
 180
 181         store_obj_destroy(obj);
 182         sdb_data_free_datum(&ATTR(obj)->value);
 183 } /* sdb_attr_destroy */
 184
 185 static sdb_type_t sdb_host_type = {
 186         sizeof(sdb_host_t),
 187         sdb_host_init,
 188         sdb_host_destroy
 189 };
 190
 191 static sdb_type_t sdb_service_type = {
 192         sizeof(sdb_service_t),
 193         sdb_service_init,
 194         sdb_service_destroy
 195 };
 196
 197 static sdb_type_t sdb_attribute_type = {
 198         sizeof(sdb_attribute_t),
 199         sdb_attr_init,
 200         sdb_attr_destroy
 201 };
 202
 203 /*
 204  * private helper functions
 205  */
 206
 207 static sdb_host_t *
 208 lookup_host(const char *name)
 209 {
 210         return HOST(sdb_llist_search_by_name(host_list, name));
 211 } /* lookup_host */
 212
 213 static int
 214 record_backend(sdb_store_obj_t *obj)
 215 {
 216         const sdb_plugin_info_t *info;
 217         char **tmp;
 218         size_t i;
 219
 220         info = sdb_plugin_current();
 221         if (! info)
 222                 return 0;
 223
 224         for (i = 0; i < obj->backends_num; ++i)
 225                 if (!strcasecmp(obj->backends[i], info->plugin_name))
 226                         return 0;
 227
 228         tmp = realloc(obj->backends,
 229                         (obj->backends_num + 1) * sizeof(*obj->backends));
 230         if (! tmp)
 231                 return -1;
 232
 233         obj->backends = tmp;
 234         obj->backends[obj->backends_num] = strdup(info->plugin_name);
 235         if (! obj->backends[obj->backends_num])
 236                 return -1;
 237
 238         ++obj->backends_num;
 239         return 0;
 240 } /* record_backend */
 241
 242 static int
 243 store_obj(sdb_llist_t *parent_list, int type, const char *name,
 244                 sdb_time_t last_update, sdb_store_obj_t **updated_obj)
 245 {
 246         sdb_store_obj_t *old, *new;
 247         int status = 0;
 248
 249         assert(parent_list);
 250
 251         if (last_update <= 0)
 252                 last_update = sdb_gettime();
 253
 254         old = STORE_OBJ(sdb_llist_search_by_name(parent_list, name));
 255         if (old) {
 256                 if (old->last_update >= last_update) {
 257                         sdb_log(SDB_LOG_DEBUG, "store: Cannot update %s '%s' - "
 258                                         "value too old (%"PRIscTIME" < %"PRIscTIME")",
 259                                         SDB_STORE_TYPE_TO_NAME(type), name,
 260                                         last_update, old->last_update);
 261                         /* don't report an error; the object may be updated by multiple
 262                          * backends */
 263                         status = 1;
 264                 }
 265                 else {
 266                         sdb_time_t interval = last_update - old->last_update;
 267                         old->last_update = last_update;
 268                         if (interval) {
 269                                 if (old->interval)
 270                                         old->interval = (sdb_time_t)((0.9 * (double)old->interval)
 271                                                         + (0.1 * (double)interval));
 272                                 else
 273                                         old->interval = interval;
 274                         }
 275                 }
 276
 277                 new = old;
 278         }
 279         else {
 280                 if (type == SDB_ATTRIBUTE) {
 281                         /* the value will be updated by the caller */
 282                         new = STORE_OBJ(sdb_object_create(name, sdb_attribute_type,
 283                                                 type, last_update, NULL));
 284                 }
 285                 else {
 286                         sdb_type_t t;
 287                         t = type == SDB_HOST ? sdb_host_type : sdb_service_type;
 288                         new = STORE_OBJ(sdb_object_create(name, t, type, last_update));
 289                 }
 290
 291                 if (new) {
 292                         status = sdb_llist_insert_sorted(parent_list, SDB_OBJ(new),
 293                                         sdb_object_cmp_by_name);
 294
 295                         /* pass control to the list or destroy in case of an error */
 296                         sdb_object_deref(SDB_OBJ(new));
 297                 }
 298                 else {
 299                         char errbuf[1024];
 300                         sdb_log(SDB_LOG_ERR, "store: Failed to create %s '%s': %s",
 301                                         SDB_STORE_TYPE_TO_NAME(type), name,
 302                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 303                         status = -1;
 304                 }
 305         }
 306
 307         if (status < 0)
 308                 return status;
 309         assert(new);
 310
 311         if (updated_obj)
 312                 *updated_obj = new;
 313
 314         if (record_backend(new))
 315                 return -1;
 316         return status;
 317 } /* store_obj */
 318
 319 static int
 320 store_attr(sdb_llist_t *attributes, const char *key, const sdb_data_t *value,
 321                 sdb_time_t last_update)
 322 {
 323         sdb_store_obj_t *attr = NULL;
 324         int status;
 325
 326         status = store_obj(attributes, SDB_ATTRIBUTE, key, last_update, &attr);
 327         if (status)
 328                 return status;
 329
 330         /* don't update unchanged values */
 331         if (! sdb_data_cmp(&ATTR(attr)->value, value))
 332                 return status;
 333
 334         assert(attr);
 335         if (sdb_data_copy(&ATTR(attr)->value, value))
 336                 return -1;
 337         return status;
 338 } /* store_attr */
 339
 340 /* The host_lock has to be acquired before calling this function. */
 341 static sdb_llist_t *
 342 get_host_children(const char *hostname, int type)
 343 {
 344         char *cname = NULL;
 345         sdb_host_t *host;
 346
 347         assert(hostname);
 348         assert((type == SDB_SERVICE) || (type == SDB_ATTRIBUTE));
 349
 350         if (! host_list)
 351                 return NULL;
 352
 353         cname = sdb_plugin_cname(strdup(hostname));
 354         if (! cname) {
 355                 sdb_log(SDB_LOG_ERR, "store: strdup failed");
 356                 return NULL;
 357         }
 358
 359         host = lookup_host(cname);
 360         free(cname);
 361         if (! host)
 362                 return NULL;
 363
 364         if (type == SDB_ATTRIBUTE)
 365                 return host->attributes;
 366         else
 367                 return host->services;
 368 } /* get_host_children */
 369
 370 /*
 371  * store_common_tojson serializes common object attributes to JSON.
 372  *
 373  * The function never returns an error. Rather, an error message will be part
 374  * of the serialized data.
 375  */
 376 static void
 377 store_common_tojson(sdb_store_obj_t *obj, sdb_strbuf_t *buf)
 378 {
 379         char time_str[64];
 380         char interval_str[64];
 381         size_t i;
 382
 383         if (! sdb_strftime(time_str, sizeof(time_str),
 384                                 "%F %T %z", obj->last_update))
 385                 snprintf(time_str, sizeof(time_str), "<error>");
 386         time_str[sizeof(time_str) - 1] = '\0';
 387
 388         if (! sdb_strfinterval(interval_str, sizeof(interval_str),
 389                                 obj->interval))
 390                 snprintf(interval_str, sizeof(interval_str), "<error>");
 391         interval_str[sizeof(interval_str) - 1] = '\0';
 392
 393         sdb_strbuf_append(buf, "\"last_update\": \"%s\", "
 394                         "\"update_interval\": \"%s\", \"backends\": [",
 395                         time_str, interval_str);
 396
 397         for (i = 0; i < obj->backends_num; ++i) {
 398                 sdb_strbuf_append(buf, "\"%s\"", obj->backends[i]);
 399                 if (i < obj->backends_num - 1)
 400                         sdb_strbuf_append(buf, ",");
 401         }
 402         sdb_strbuf_append(buf, "]");
 403 } /* store_common_tojson */
 404
 405 /*
 406  * store_obj_tojson serializes attribute / service objects to JSON.
 407  *
 408  * The function never returns an error. Rather, an error message will be part
 409  * of the serialized data.
 410  */
 411 static void
 412 store_obj_tojson(sdb_llist_t *list, int type, sdb_strbuf_t *buf)
 413 {
 414         sdb_llist_iter_t *iter;
 415
 416         assert((type == SDB_ATTRIBUTE) || (type == SDB_SERVICE));
 417
 418         sdb_strbuf_append(buf, "[");
 419         iter = sdb_llist_get_iter(list);
 420         if (! iter) {
 421                 char errbuf[1024];
 422                 sdb_log(SDB_LOG_ERR, "store: Failed to retrieve %ss: %s\n",
 423                                 SDB_STORE_TYPE_TO_NAME(type),
 424                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 425                 sdb_strbuf_append(buf, "{\"error\": \"failed to retrieve %ss: %s\"}",
 426                                 SDB_STORE_TYPE_TO_NAME(type), errbuf);
 427         }
 428
 429         /* has_next returns false if the iterator is NULL */
 430         while (sdb_llist_iter_has_next(iter)) {
 431                 sdb_store_obj_t *sobj = STORE_OBJ(sdb_llist_iter_get_next(iter));
 432                 assert(sobj);
 433                 assert(sobj->type == type);
 434
 435                 sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(sobj)->name);
 436                 if (sobj->type == SDB_ATTRIBUTE) {
 437                         char tmp[sdb_data_strlen(&ATTR(sobj)->value) + 1];
 438                         sdb_data_format(&ATTR(sobj)->value, tmp, sizeof(tmp),
 439                                         SDB_DOUBLE_QUOTED);
 440                         sdb_strbuf_append(buf, "\"value\": %s, ", tmp);
 441                 }
 442
 443                 store_common_tojson(sobj, buf);
 444                 sdb_strbuf_append(buf, "}");
 445
 446                 if (sdb_llist_iter_has_next(iter))
 447                         sdb_strbuf_append(buf, ",");
 448         }
 449
 450         sdb_llist_iter_destroy(iter);
 451         sdb_strbuf_append(buf, "]");
 452 } /* store_obj_tojson */
 453
 454 /*
 455  * public API
 456  */
 457
 458 void
 459 sdb_store_clear(void)
 460 {
 461         sdb_llist_destroy(host_list);
 462         host_list = NULL;
 463 } /* sdb_store_clear */
 464
 465 int
 466 sdb_store_host(const char *name, sdb_time_t last_update)
 467 {
 468         char *cname = NULL;
 469         int status = 0;
 470
 471         if (! name)
 472                 return -1;
 473
 474         cname = sdb_plugin_cname(strdup(name));
 475         if (! cname) {
 476                 sdb_log(SDB_LOG_ERR, "store: strdup failed");
 477                 return -1;
 478         }
 479
 480         pthread_rwlock_wrlock(&host_lock);
 481         if (! host_list)
 482                 if (! (host_list = sdb_llist_create()))
 483                         status = -1;
 484
 485         if (! status)
 486                 status = store_obj(host_list, SDB_HOST, cname, last_update, NULL);
 487         pthread_rwlock_unlock(&host_lock);
 488
 489         free(cname);
 490         return status;
 491 } /* sdb_store_host */
 492
 493 _Bool
 494 sdb_store_has_host(const char *name)
 495 {
 496         sdb_host_t *host;
 497
 498         if (! name)
 499                 return NULL;
 500
 501         host = lookup_host(name);
 502         return host != NULL;
 503 } /* sdb_store_has_host */
 504
 505 sdb_store_obj_t *
 506 sdb_store_get_host(const char *name)
 507 {
 508         sdb_host_t *host;
 509
 510         if (! name)
 511                 return NULL;
 512
 513         host = lookup_host(name);
 514         if (! host)
 515                 return NULL;
 516
 517         sdb_object_ref(SDB_OBJ(host));
 518         return STORE_OBJ(host);
 519 } /* sdb_store_get_host */
 520
 521 int
 522 sdb_store_attribute(const char *hostname,
 523                 const char *key, const sdb_data_t *value,
 524                 sdb_time_t last_update)
 525 {
 526         sdb_llist_t *attrs;
 527         int status = 0;
 528
 529         if ((! hostname) || (! key))
 530                 return -1;
 531
 532         pthread_rwlock_wrlock(&host_lock);
 533         attrs = get_host_children(hostname, SDB_ATTRIBUTE);
 534         if (! attrs) {
 535                 sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' - "
 536                                 "host '%s' not found", key, hostname);
 537                 status = -1;
 538         }
 539
 540         if (! status)
 541                 status = store_attr(attrs, key, value, last_update);
 542
 543         pthread_rwlock_unlock(&host_lock);
 544         return status;
 545 } /* sdb_store_attribute */
 546
 547 int
 548 sdb_store_service(const char *hostname, const char *name,
 549                 sdb_time_t last_update)
 550 {
 551         sdb_llist_t *services;
 552
 553         int status = 0;
 554
 555         if ((! hostname) || (! name))
 556                 return -1;
 557
 558         pthread_rwlock_wrlock(&host_lock);
 559         services = get_host_children(hostname, SDB_SERVICE);
 560         if (! services) {
 561                 sdb_log(SDB_LOG_ERR, "store: Failed to store service '%s' - "
 562                                 "host '%s' not found", name, hostname);
 563                 status = -1;
 564         }
 565
 566         if (! status)
 567                 status = store_obj(services, SDB_SERVICE, name, last_update, NULL);
 568         pthread_rwlock_unlock(&host_lock);
 569         return status;
 570 } /* sdb_store_service */
 571
 572 int
 573 sdb_store_service_attr(const char *hostname, const char *service,
 574                 const char *key, const sdb_data_t *value, sdb_time_t last_update)
 575 {
 576         sdb_llist_t *services;
 577         sdb_service_t *svc;
 578         int status = 0;
 579
 580         if ((! hostname) || (! service) || (! key))
 581                 return -1;
 582
 583         pthread_rwlock_wrlock(&host_lock);
 584         services = get_host_children(hostname, SDB_SERVICE);
 585         if (! services) {
 586                 sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' "
 587                                 "for service '%s' - host '%ss' not found",
 588                                 key, service, hostname);
 589                 pthread_rwlock_unlock(&host_lock);
 590                 return -1;
 591         }
 592
 593         svc = SVC(sdb_llist_search_by_name(services, service));
 594         if (! svc) {
 595                 sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' - "
 596                                 "service '%s/%s' not found", key, hostname, service);
 597                 status = -1;
 598         }
 599
 600         if (! status)
 601                 status = store_attr(svc->attributes, key, value, last_update);
 602
 603         pthread_rwlock_unlock(&host_lock);
 604         return status;
 605 } /* sdb_store_service_attr */
 606
 607 int
 608 sdb_store_host_tojson(sdb_store_obj_t *h, sdb_strbuf_t *buf, int flags)
 609 {
 610         sdb_host_t *host;
 611
 612         if ((! h) || (h->type != SDB_HOST) || (! buf))
 613                 return -1;
 614
 615         host = HOST(h);
 616
 617         sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(host)->name);
 618         store_common_tojson(h, buf);
 619
 620         if (! (flags & SDB_SKIP_ATTRIBUTES)) {
 621                 sdb_strbuf_append(buf, ", \"attributes\": ");
 622                 store_obj_tojson(host->attributes, SDB_ATTRIBUTE, buf);
 623         }
 624
 625         if (! (flags & SDB_SKIP_SERVICES)) {
 626                 sdb_strbuf_append(buf, ", \"services\": ");
 627                 store_obj_tojson(host->services, SDB_SERVICE, buf);
 628         }
 629
 630         sdb_strbuf_append(buf, "}");
 631         return 0;
 632 } /* sdb_store_host_tojson */
 633
 634 int
 635 sdb_store_tojson(sdb_strbuf_t *buf, int flags)
 636 {
 637         sdb_llist_iter_t *host_iter;
 638
 639         if (! buf)
 640                 return -1;
 641
 642         pthread_rwlock_rdlock(&host_lock);
 643
 644         host_iter = sdb_llist_get_iter(host_list);
 645         if (! host_iter) {
 646                 pthread_rwlock_unlock(&host_lock);
 647                 return -1;
 648         }
 649
 650         sdb_strbuf_append(buf, "{\"hosts\":[");
 651
 652         while (sdb_llist_iter_has_next(host_iter)) {
 653                 sdb_store_obj_t *host = STORE_OBJ(sdb_llist_iter_get_next(host_iter));
 654                 assert(host);
 655
 656                 if (sdb_store_host_tojson(host, buf, flags))
 657                         return -1;
 658
 659                 if (sdb_llist_iter_has_next(host_iter))
 660                         sdb_strbuf_append(buf, ",");
 661         }
 662
 663         sdb_strbuf_append(buf, "]}");
 664
 665         sdb_llist_iter_destroy(host_iter);
 666         pthread_rwlock_unlock(&host_lock);
 667         return 0;
 668 } /* sdb_store_tojson */
 669
 670 /* TODO: actually support hierarchical data */
 671 int
 672 sdb_store_iterate(sdb_store_iter_cb cb, void *user_data)
 673 {
 674         sdb_llist_iter_t *host_iter;
 675         int status = 0;
 676
 677         pthread_rwlock_rdlock(&host_lock);
 678
 679         host_iter = sdb_llist_get_iter(host_list);
 680         if (! host_iter)
 681                 status = -1;
 682
 683         /* has_next returns false if the iterator is NULL */
 684         while (sdb_llist_iter_has_next(host_iter)) {
 685                 sdb_store_obj_t *host = STORE_OBJ(sdb_llist_iter_get_next(host_iter));
 686                 assert(host);
 687
 688                 if (cb(host, user_data)) {
 689                         status = -1;
 690                         break;
 691                 }
 692         }
 693
 694         sdb_llist_iter_destroy(host_iter);
 695         pthread_rwlock_unlock(&host_lock);
 696         return status;
 697 } /* sdb_store_iterate */
 698
 699 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 700