external/gpl2/lvm2/dist/lib/config/config.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
   5  * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
   6  *
   7  * This file is part of LVM2.
   8  *
   9  * This copyrighted material is made available to anyone wishing to use,
  10  * modify, copy, or redistribute it subject to the terms and conditions
  11  * of the GNU Lesser General Public License v.2.1.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this program; if not, write to the Free Software Foundation,
  15  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16  */
  17
  18 #include "lib.h"
  19 #include "config.h"
  20 #include "crc.h"
  21 #include "device.h"
  22 #include "str_list.h"
  23 #include "toolcontext.h"
  24 #include "lvm-string.h"
  25 #include "lvm-file.h"
  26
  27 #include <sys/stat.h>
  28 #include <sys/mman.h>
  29 #include <unistd.h>
  30 #include <fcntl.h>
  31 #include <ctype.h>
  32
  33 #define SECTION_B_CHAR '{'
  34 #define SECTION_E_CHAR '}'
  35
  36 enum {
  37         TOK_INT,
  38         TOK_FLOAT,
  39         TOK_STRING,             /* Single quotes */
  40         TOK_STRING_ESCAPED,     /* Double quotes */
  41         TOK_EQ,
  42         TOK_SECTION_B,
  43         TOK_SECTION_E,
  44         TOK_ARRAY_B,
  45         TOK_ARRAY_E,
  46         TOK_IDENTIFIER,
  47         TOK_COMMA,
  48         TOK_EOF
  49 };
  50
  51 struct parser {
  52         const char *fb, *fe;            /* file limits */
  53
  54         int t;                  /* token limits and type */
  55         const char *tb, *te;
  56
  57         int fd;                 /* descriptor for file being parsed */
  58         int line;               /* line number we are on */
  59
  60         struct dm_pool *mem;
  61 };
  62
  63 struct cs {
  64         struct config_tree cft;
  65         struct dm_pool *mem;
  66         time_t timestamp;
  67         char *filename;
  68         int exists;
  69         int keep_open;
  70         struct device *dev;
  71 };
  72
  73 struct output_line {
  74         FILE *fp;
  75         struct dm_pool *mem;
  76         putline_fn putline;
  77         void *putline_baton;
  78 };
  79
  80 static void _get_token(struct parser *p, int tok_prev);
  81 static void _eat_space(struct parser *p);
  82 static struct config_node *_file(struct parser *p);
  83 static struct config_node *_section(struct parser *p);
  84 static struct config_value *_value(struct parser *p);
  85 static struct config_value *_type(struct parser *p);
  86 static int _match_aux(struct parser *p, int t);
  87 static struct config_value *_create_value(struct dm_pool *mem);
  88 static struct config_node *_create_node(struct dm_pool *mem);
  89 static char *_dup_tok(struct parser *p);
  90
  91 static const int sep = '/';
  92
  93 #define MAX_INDENT 32
  94
  95 #define match(t) do {\
  96    if (!_match_aux(p, (t))) {\
  97         log_error("Parse error at byte %" PRIptrdiff_t " (line %d): unexpected token", \
  98                   p->tb - p->fb + 1, p->line); \
  99       return 0;\
 100    } \
 101 } while(0);
 102
 103 static int _tok_match(const char *str, const char *b, const char *e)
 104 {
 105         while (*str && (b != e)) {
 106                 if (*str++ != *b++)
 107                         return 0;
 108         }
 109
 110         return !(*str || (b != e));
 111 }
 112
 113 /*
 114  * public interface
 115  */
 116 struct config_tree *create_config_tree(const char *filename, int keep_open)
 117 {
 118         struct cs *c;
 119         struct dm_pool *mem = dm_pool_create("config", 10 * 1024);
 120
 121         if (!mem) {
 122                 log_error("Failed to allocate config pool.");
 123                 return 0;
 124         }
 125
 126         if (!(c = dm_pool_zalloc(mem, sizeof(*c)))) {
 127                 log_error("Failed to allocate config tree.");
 128                 dm_pool_destroy(mem);
 129                 return 0;
 130         }
 131
 132         c->mem = mem;
 133         c->cft.root = (struct config_node *) NULL;
 134         c->timestamp = 0;
 135         c->exists = 0;
 136         c->keep_open = keep_open;
 137         c->dev = 0;
 138         if (filename)
 139                 c->filename = dm_pool_strdup(c->mem, filename);
 140         return &c->cft;
 141 }
 142
 143 void destroy_config_tree(struct config_tree *cft)
 144 {
 145         struct cs *c = (struct cs *) cft;
 146
 147         if (c->dev)
 148                 dev_close(c->dev);
 149
 150         dm_pool_destroy(c->mem);
 151 }
 152
 153 static int _parse_config_file(struct parser *p, struct config_tree *cft)
 154 {
 155         p->tb = p->te = p->fb;
 156         p->line = 1;
 157         _get_token(p, TOK_SECTION_E);
 158         if (!(cft->root = _file(p)))
 159                 return_0;
 160
 161         return 1;
 162 }
 163
 164 struct config_tree *create_config_tree_from_string(struct cmd_context *cmd __attribute((unused)),
 165                                                    const char *config_settings)
 166 {
 167         struct cs *c;
 168         struct config_tree *cft;
 169         struct parser *p;
 170
 171         if (!(cft = create_config_tree(NULL, 0)))
 172                 return_NULL;
 173
 174         c = (struct cs *) cft;
 175         if (!(p = dm_pool_alloc(c->mem, sizeof(*p)))) {
 176                 log_error("Failed to allocate config tree parser.");
 177                 destroy_config_tree(cft);
 178                 return NULL;
 179         }
 180
 181         p->mem = c->mem;
 182         p->fb = config_settings;
 183         p->fe = config_settings + strlen(config_settings);
 184
 185         if (!_parse_config_file(p, cft)) {
 186                 destroy_config_tree(cft);
 187                 return_NULL;
 188         }
 189
 190         return cft;
 191 }
 192
 193 int override_config_tree_from_string(struct cmd_context *cmd,
 194                                      const char *config_settings)
 195 {
 196         if (!(cmd->cft_override = create_config_tree_from_string(cmd,config_settings))) {
 197                 log_error("Failed to set overridden configuration entries.");
 198                 return 1;
 199         }
 200
 201         return 0;
 202 }
 203
 204 int read_config_fd(struct config_tree *cft, struct device *dev,
 205                    off_t offset, size_t size, off_t offset2, size_t size2,
 206                    checksum_fn_t checksum_fn, uint32_t checksum)
 207 {
 208         struct cs *c = (struct cs *) cft;
 209         struct parser *p;
 210         int r = 0;
 211         int use_mmap = 1;
 212         off_t mmap_offset = 0;
 213         char *buf = NULL;
 214
 215         if (!(p = dm_pool_alloc(c->mem, sizeof(*p))))
 216                 return_0;
 217         p->mem = c->mem;
 218
 219         /* Only use mmap with regular files */
 220         if (!(dev->flags & DEV_REGULAR) || size2)
 221                 use_mmap = 0;
 222
 223         if (use_mmap) {
 224                 mmap_offset = offset % lvm_getpagesize();
 225                 /* memory map the file */
 226                 p->fb = mmap((caddr_t) 0, size + mmap_offset, PROT_READ,
 227                              MAP_PRIVATE, dev_fd(dev), offset - mmap_offset);
 228                 if (p->fb == (caddr_t) (-1)) {
 229                         log_sys_error("mmap", dev_name(dev));
 230                         goto out;
 231                 }
 232                 p->fb = p->fb + mmap_offset;
 233         } else {
 234                 if (!(buf = dm_malloc(size + size2)))
 235                         return_0;
 236                 if (!dev_read_circular(dev, (uint64_t) offset, size,
 237                                        (uint64_t) offset2, size2, buf)) {
 238                         goto out;
 239                 }
 240                 p->fb = buf;
 241         }
 242
 243         if (checksum_fn && checksum !=
 244             (checksum_fn(checksum_fn(INITIAL_CRC, p->fb, size),
 245                          p->fb + size, size2))) {
 246                 log_error("%s: Checksum error", dev_name(dev));
 247                 goto out;
 248         }
 249
 250         p->fe = p->fb + size + size2;
 251
 252         if (!_parse_config_file(p, cft))
 253                 goto_out;
 254
 255         r = 1;
 256
 257       out:
 258         if (!use_mmap)
 259                 dm_free(buf);
 260         else {
 261                 /* unmap the file */
 262                 if (munmap((char *) (p->fb - mmap_offset), size + mmap_offset)) {
 263                         log_sys_error("munmap", dev_name(dev));
 264                         r = 0;
 265                 }
 266         }
 267
 268         return r;
 269 }
 270
 271 int read_config_file(struct config_tree *cft)
 272 {
 273         struct cs *c = (struct cs *) cft;
 274         struct stat info;
 275         int r = 1;
 276
 277         if (stat(c->filename, &info)) {
 278                 log_sys_error("stat", c->filename);
 279                 c->exists = 0;
 280                 return 0;
 281         }
 282
 283         if (!S_ISREG(info.st_mode)) {
 284                 log_error("%s is not a regular file", c->filename);
 285                 c->exists = 0;
 286                 return 0;
 287         }
 288
 289         c->exists = 1;
 290
 291         if (info.st_size == 0) {
 292                 log_verbose("%s is empty", c->filename);
 293                 return 1;
 294         }
 295
 296         if (!c->dev) {
 297                 if (!(c->dev = dev_create_file(c->filename, NULL, NULL, 1)))
 298                         return_0;
 299
 300                 if (!dev_open_flags(c->dev, O_RDONLY, 0, 0))
 301                         return_0;
 302         }
 303
 304         r = read_config_fd(cft, c->dev, 0, (size_t) info.st_size, 0, 0,
 305                            (checksum_fn_t) NULL, 0);
 306
 307         if (!c->keep_open) {
 308                 dev_close(c->dev);
 309                 c->dev = 0;
 310         }
 311
 312         c->timestamp = info.st_ctime;
 313
 314         return r;
 315 }
 316
 317 time_t config_file_timestamp(struct config_tree *cft)
 318 {
 319         struct cs *c = (struct cs *) cft;
 320
 321         return c->timestamp;
 322 }
 323
 324 /*
 325  * Return 1 if config files ought to be reloaded
 326  */
 327 int config_file_changed(struct config_tree *cft)
 328 {
 329         struct cs *c = (struct cs *) cft;
 330         struct stat info;
 331
 332         if (!c->filename)
 333                 return 0;
 334
 335         if (stat(c->filename, &info) == -1) {
 336                 /* Ignore a deleted config file: still use original data */
 337                 if (errno == ENOENT) {
 338                         if (!c->exists)
 339                                 return 0;
 340                         log_very_verbose("Config file %s has disappeared!",
 341                                          c->filename);
 342                         goto reload;
 343                 }
 344                 log_sys_error("stat", c->filename);
 345                 log_error("Failed to reload configuration files");
 346                 return 0;
 347         }
 348
 349         if (!S_ISREG(info.st_mode)) {
 350                 log_error("Configuration file %s is not a regular file",
 351                           c->filename);
 352                 goto reload;
 353         }
 354
 355         /* Unchanged? */
 356         if (c->timestamp == info.st_ctime)
 357                 return 0;
 358
 359       reload:
 360         log_verbose("Detected config file change to %s", c->filename);
 361         return 1;
 362 }
 363
 364 static int _line_start(struct output_line *outline)
 365 {
 366         if (!dm_pool_begin_object(outline->mem, 128)) {
 367                 log_error("dm_pool_begin_object failed for config line");
 368                 return 0;
 369         }
 370
 371         return 1;
 372 }
 373
 374 static int _line_append(struct output_line *outline, const char *fmt, ...)
 375   __attribute__ ((format(printf, 2, 3)));
 376 static int _line_append(struct output_line *outline, const char *fmt, ...)
 377 {
 378         char buf[4096];
 379         va_list ap;
 380         int n;
 381
 382         va_start(ap, fmt);
 383         n = vsnprintf(&buf[0], sizeof buf - 1, fmt, ap);
 384         if (n < 0 || n > (int) sizeof buf - 1) {
 385                 log_error("vsnprintf failed for config line");
 386                 return 0;
 387         }
 388         va_end(ap);
 389
 390         if (!dm_pool_grow_object(outline->mem, &buf[0], strlen(buf))) {
 391                 log_error("dm_pool_grow_object failed for config line");
 392                 return 0;
 393         }
 394
 395         return 1;
 396 }
 397
 398 #define line_append(args...) do {if (!_line_append(outline, args)) {return_0;}} while (0)
 399
 400 static int _line_end(struct output_line *outline)
 401 {
 402         const char *line;
 403
 404         if (!dm_pool_grow_object(outline->mem, "\0", 1)) {
 405                 log_error("dm_pool_grow_object failed for config line");
 406                 return 0;
 407         }
 408
 409         line = dm_pool_end_object(outline->mem);
 410         if (outline->putline)
 411                 outline->putline(line, outline->putline_baton);
 412         else {
 413                 if (!outline->fp)
 414                         log_print("%s", line);
 415                 else
 416                         fprintf(outline->fp, "%s\n", line);
 417         }
 418
 419         return 1;
 420 }
 421
 422 static int _write_value(struct output_line *outline, struct config_value *v)
 423 {
 424         char *buf;
 425
 426         switch (v->type) {
 427         case CFG_STRING:
 428                 if (!(buf = alloca(escaped_len(v->v.str)))) {
 429                         log_error("temporary stack allocation for a config "
 430                                   "string failed");
 431                         return 0;
 432                 }
 433                 line_append("\"%s\"", escape_double_quotes(buf, v->v.str));
 434                 break;
 435
 436         case CFG_FLOAT:
 437                 line_append("%f", v->v.r);
 438                 break;
 439
 440         case CFG_INT:
 441                 line_append("%" PRId64, v->v.i);
 442                 break;
 443
 444         case CFG_EMPTY_ARRAY:
 445                 line_append("[]");
 446                 break;
 447
 448         default:
 449                 log_error("_write_value: Unknown value type: %d", v->type);
 450
 451         }
 452
 453         return 1;
 454 }
 455
 456 static int _write_config(const struct config_node *n, int only_one,
 457                          struct output_line *outline, int level)
 458 {
 459         char space[MAX_INDENT + 1];
 460         int l = (level < MAX_INDENT) ? level : MAX_INDENT;
 461         int i;
 462
 463         if (!n)
 464                 return 1;
 465
 466         for (i = 0; i < l; i++)
 467                 space[i] = '\t';
 468         space[i] = '\0';
 469
 470         do {
 471                 if (!_line_start(outline))
 472                         return_0;
 473                 line_append("%s%s", space, n->key);
 474                 if (!n->v) {
 475                         /* it's a sub section */
 476                         line_append(" {");
 477                         if (!_line_end(outline))
 478                                 return_0;
 479                         _write_config(n->child, 0, outline, level + 1);
 480                         if (!_line_start(outline))
 481                                 return_0;
 482                         line_append("%s}", space);
 483                 } else {
 484                         /* it's a value */
 485                         struct config_value *v = n->v;
 486                         line_append("=");
 487                         if (v->next) {
 488                                 line_append("[");
 489                                 while (v) {
 490                                         if (!_write_value(outline, v))
 491                                                 return_0;
 492                                         v = v->next;
 493                                         if (v)
 494                                                 line_append(", ");
 495                                 }
 496                                 line_append("]");
 497                         } else
 498                                 if (!_write_value(outline, v))
 499                                         return_0;
 500                 }
 501                 if (!_line_end(outline))
 502                         return_0;
 503                 n = n->sib;
 504         } while (n && !only_one);
 505         /* FIXME: add error checking */
 506         return 1;
 507 }
 508
 509 int write_config_node(const struct config_node *cn, putline_fn putline, void *baton)
 510 {
 511         struct output_line outline;
 512         outline.fp = NULL;
 513         outline.mem = dm_pool_create("config_line", 1024);
 514         outline.putline = putline;
 515         outline.putline_baton = baton;
 516         if (!_write_config(cn, 0, &outline, 0)) {
 517                 dm_pool_destroy(outline.mem);
 518                 return_0;
 519         }
 520         dm_pool_destroy(outline.mem);
 521         return 1;
 522 }
 523
 524 int write_config_file(struct config_tree *cft, const char *file,
 525                       int argc, char **argv)
 526 {
 527         struct config_node *cn;
 528         int r = 1;
 529         struct output_line outline;
 530         outline.fp = NULL;
 531         outline.putline = NULL;
 532
 533         if (!file)
 534                 file = "stdout";
 535         else if (!(outline.fp = fopen(file, "w"))) {
 536                 log_sys_error("open", file);
 537                 return 0;
 538         }
 539
 540         outline.mem = dm_pool_create("config_line", 1024);
 541
 542         log_verbose("Dumping configuration to %s", file);
 543         if (!argc) {
 544                 if (!_write_config(cft->root, 0, &outline, 0)) {
 545                         log_error("Failure while writing to %s", file);
 546                         r = 0;
 547                 }
 548         } else while (argc--) {
 549                 if ((cn = find_config_node(cft->root, *argv))) {
 550                         if (!_write_config(cn, 1, &outline, 0)) {
 551                                 log_error("Failure while writing to %s", file);
 552                                 r = 0;
 553                         }
 554                 } else {
 555                         log_error("Configuration node %s not found", *argv);
 556                         r = 0;
 557                 }
 558                 argv++;
 559         }
 560
 561         if (outline.fp && lvm_fclose(outline.fp, file)) {
 562                 stack;
 563                 r = 0;
 564         }
 565
 566         dm_pool_destroy(outline.mem);
 567         return r;
 568 }
 569
 570 /*
 571  * parser
 572  */
 573 static struct config_node *_file(struct parser *p)
 574 {
 575         struct config_node *root = NULL, *n, *l = NULL;
 576         while (p->t != TOK_EOF) {
 577                 if (!(n = _section(p)))
 578                         return_0;
 579
 580                 if (!root)
 581                         root = n;
 582                 else
 583                         l->sib = n;
 584                 n->parent = root;
 585                 l = n;
 586         }
 587         return root;
 588 }
 589
 590 static struct config_node *_section(struct parser *p)
 591 {
 592         /* IDENTIFIER SECTION_B_CHAR VALUE* SECTION_E_CHAR */
 593         struct config_node *root, *n, *l = NULL;
 594         if (!(root = _create_node(p->mem)))
 595                 return_0;
 596
 597         if (!(root->key = _dup_tok(p)))
 598                 return_0;
 599
 600         match(TOK_IDENTIFIER);
 601
 602         if (p->t == TOK_SECTION_B) {
 603                 match(TOK_SECTION_B);
 604                 while (p->t != TOK_SECTION_E) {
 605                         if (!(n = _section(p)))
 606                                 return_0;
 607
 608                         if (!root->child)
 609                                 root->child = n;
 610                         else
 611                                 l->sib = n;
 612                         n->parent = root;
 613                         l = n;
 614                 }
 615                 match(TOK_SECTION_E);
 616         } else {
 617                 match(TOK_EQ);
 618                 if (!(root->v = _value(p)))
 619                         return_0;
 620         }
 621
 622         return root;
 623 }
 624
 625 static struct config_value *_value(struct parser *p)
 626 {
 627         /* '[' TYPE* ']' | TYPE */
 628         struct config_value *h = NULL, *l, *ll = NULL;
 629         if (p->t == TOK_ARRAY_B) {
 630                 match(TOK_ARRAY_B);
 631                 while (p->t != TOK_ARRAY_E) {
 632                         if (!(l = _type(p)))
 633                                 return_0;
 634
 635                         if (!h)
 636                                 h = l;
 637                         else
 638                                 ll->next = l;
 639                         ll = l;
 640
 641                         if (p->t == TOK_COMMA)
 642                                 match(TOK_COMMA);
 643                 }
 644                 match(TOK_ARRAY_E);
 645                 /*
 646                  * Special case for an empty array.
 647                  */
 648                 if (!h) {
 649                         if (!(h = _create_value(p->mem)))
 650                                 return NULL;
 651
 652                         h->type = CFG_EMPTY_ARRAY;
 653                 }
 654
 655         } else
 656                 h = _type(p);
 657
 658         return h;
 659 }
 660
 661 static struct config_value *_type(struct parser *p)
 662 {
 663         /* [+-]{0,1}[0-9]+ | [0-9]*\.[0-9]* | ".*" */
 664         struct config_value *v = _create_value(p->mem);
 665
 666         if (!v)
 667                 return NULL;
 668
 669         switch (p->t) {
 670         case TOK_INT:
 671                 v->type = CFG_INT;
 672                 v->v.i = strtoll(p->tb, NULL, 0);       /* FIXME: check error */
 673                 match(TOK_INT);
 674                 break;
 675
 676         case TOK_FLOAT:
 677                 v->type = CFG_FLOAT;
 678                 v->v.r = strtod(p->tb, NULL);   /* FIXME: check error */
 679                 match(TOK_FLOAT);
 680                 break;
 681
 682         case TOK_STRING:
 683                 v->type = CFG_STRING;
 684
 685                 p->tb++, p->te--;       /* strip "'s */
 686                 if (!(v->v.str = _dup_tok(p)))
 687                         return_0;
 688                 p->te++;
 689                 match(TOK_STRING);
 690                 break;
 691
 692         case TOK_STRING_ESCAPED:
 693                 v->type = CFG_STRING;
 694
 695                 p->tb++, p->te--;       /* strip "'s */
 696                 if (!(v->v.str = _dup_tok(p)))
 697                         return_0;
 698                 unescape_double_quotes(v->v.str);
 699                 p->te++;
 700                 match(TOK_STRING_ESCAPED);
 701                 break;
 702
 703         default:
 704                 log_error("Parse error at byte %" PRIptrdiff_t " (line %d): expected a value",
 705                           p->tb - p->fb + 1, p->line);
 706                 return 0;
 707         }
 708         return v;
 709 }
 710
 711 static int _match_aux(struct parser *p, int t)
 712 {
 713         if (p->t != t)
 714                 return 0;
 715
 716         _get_token(p, t);
 717         return 1;
 718 }
 719
 720 /*
 721  * tokeniser
 722  */
 723 static void _get_token(struct parser *p, int tok_prev)
 724 {
 725         int values_allowed = 0;
 726
 727         p->tb = p->te;
 728         _eat_space(p);
 729         if (p->tb == p->fe || !*p->tb) {
 730                 p->t = TOK_EOF;
 731                 return;
 732         }
 733
 734         /* Should next token be interpreted as value instead of identifier? */
 735         if (tok_prev == TOK_EQ || tok_prev == TOK_ARRAY_B ||
 736             tok_prev == TOK_COMMA)
 737                 values_allowed = 1;
 738
 739         p->t = TOK_INT;         /* fudge so the fall through for
 740                                    floats works */
 741         switch (*p->te) {
 742         case SECTION_B_CHAR:
 743                 p->t = TOK_SECTION_B;
 744                 p->te++;
 745                 break;
 746
 747         case SECTION_E_CHAR:
 748                 p->t = TOK_SECTION_E;
 749                 p->te++;
 750                 break;
 751
 752         case '[':
 753                 p->t = TOK_ARRAY_B;
 754                 p->te++;
 755                 break;
 756
 757         case ']':
 758                 p->t = TOK_ARRAY_E;
 759                 p->te++;
 760                 break;
 761
 762         case ',':
 763                 p->t = TOK_COMMA;
 764                 p->te++;
 765                 break;
 766
 767         case '=':
 768                 p->t = TOK_EQ;
 769                 p->te++;
 770                 break;
 771
 772         case '"':
 773                 p->t = TOK_STRING_ESCAPED;
 774                 p->te++;
 775                 while ((p->te != p->fe) && (*p->te) && (*p->te != '"')) {
 776                         if ((*p->te == '\\') && (p->te + 1 != p->fe) &&
 777                             *(p->te + 1))
 778                                 p->te++;
 779                         p->te++;
 780                 }
 781
 782                 if ((p->te != p->fe) && (*p->te))
 783                         p->te++;
 784                 break;
 785
 786         case '\'':
 787                 p->t = TOK_STRING;
 788                 p->te++;
 789                 while ((p->te != p->fe) && (*p->te) && (*p->te != '\''))
 790                         p->te++;
 791
 792                 if ((p->te != p->fe) && (*p->te))
 793                         p->te++;
 794                 break;
 795
 796         case '.':
 797                 p->t = TOK_FLOAT;
 798         case '0':
 799         case '1':
 800         case '2':
 801         case '3':
 802         case '4':
 803         case '5':
 804         case '6':
 805         case '7':
 806         case '8':
 807         case '9':
 808         case '+':
 809         case '-':
 810                 if (values_allowed) {
 811                         p->te++;
 812                         while ((p->te != p->fe) && (*p->te)) {
 813                                 if (*p->te == '.') {
 814                                         if (p->t == TOK_FLOAT)
 815                                                 break;
 816                                         p->t = TOK_FLOAT;
 817                                 } else if (!isdigit((int) *p->te))
 818                                         break;
 819                                 p->te++;
 820                         }
 821                         break;
 822                 }
 823
 824         default:
 825                 p->t = TOK_IDENTIFIER;
 826                 while ((p->te != p->fe) && (*p->te) && !isspace(*p->te) &&
 827                        (*p->te != '#') && (*p->te != '=') &&
 828                        (*p->te != SECTION_B_CHAR) &&
 829                        (*p->te != SECTION_E_CHAR))
 830                         p->te++;
 831                 break;
 832         }
 833 }
 834
 835 static void _eat_space(struct parser *p)
 836 {
 837         while ((p->tb != p->fe) && (*p->tb)) {
 838                 if (*p->te == '#')
 839                         while ((p->te != p->fe) && (*p->te) && (*p->te != '\n'))
 840                                 p->te++;
 841
 842                 else if (isspace(*p->te)) {
 843                         while ((p->te != p->fe) && (*p->te) && isspace(*p->te)) {
 844                                 if (*p->te == '\n')
 845                                         p->line++;
 846                                 p->te++;
 847                         }
 848                 }
 849
 850                 else
 851                         return;
 852
 853                 p->tb = p->te;
 854         }
 855 }
 856
 857 /*
 858  * memory management
 859  */
 860 static struct config_value *_create_value(struct dm_pool *mem)
 861 {
 862         struct config_value *v = dm_pool_alloc(mem, sizeof(*v));
 863
 864         if (v)
 865                 memset(v, 0, sizeof(*v));
 866
 867         return v;
 868 }
 869
 870 static struct config_node *_create_node(struct dm_pool *mem)
 871 {
 872         struct config_node *n = dm_pool_alloc(mem, sizeof(*n));
 873
 874         if (n)
 875                 memset(n, 0, sizeof(*n));
 876
 877         return n;
 878 }
 879
 880 static char *_dup_tok(struct parser *p)
 881 {
 882         size_t len = p->te - p->tb;
 883         char *str = dm_pool_alloc(p->mem, len + 1);
 884         if (!str)
 885                 return_0;
 886         strncpy(str, p->tb, len);
 887         str[len] = '\0';
 888         return str;
 889 }
 890
 891 /*
 892  * utility functions
 893  */
 894 static struct config_node *_find_config_node(const struct config_node *cn,
 895                                              const char *path)
 896 {
 897         const char *e;
 898         const struct config_node *cn_found = NULL;
 899
 900         while (cn) {
 901                 /* trim any leading slashes */
 902                 while (*path && (*path == sep))
 903                         path++;
 904
 905                 /* find the end of this segment */
 906                 for (e = path; *e && (*e != sep); e++) ;
 907
 908                 /* hunt for the node */
 909                 cn_found = NULL;
 910                 while (cn) {
 911                         if (_tok_match(cn->key, path, e)) {
 912                                 /* Inefficient */
 913                                 if (!cn_found)
 914                                         cn_found = cn;
 915                                 else
 916                                         log_error("WARNING: Ignoring duplicate"
 917                                                   " config node: %s ("
 918                                                   "seeking %s)", cn->key, path);
 919                         }
 920
 921                         cn = cn->sib;
 922                 }
 923
 924                 if (cn_found && *e)
 925                         cn = cn_found->child;
 926                 else
 927                         break;  /* don't move into the last node */
 928
 929                 path = e;
 930         }
 931
 932         return (struct config_node *) cn_found;
 933 }
 934
 935 static struct config_node *_find_first_config_node(const struct config_node *cn1,
 936                                                    const struct config_node *cn2,
 937                                                    const char *path)
 938 {
 939         struct config_node *cn;
 940
 941         if (cn1 && (cn = _find_config_node(cn1, path)))
 942                 return cn;
 943
 944         if (cn2 && (cn = _find_config_node(cn2, path)))
 945                 return cn;
 946
 947         return NULL;
 948 }
 949
 950 struct config_node *find_config_node(const struct config_node *cn,
 951                                      const char *path)
 952 {
 953         return _find_config_node(cn, path);
 954 }
 955
 956 static const char *_find_config_str(const struct config_node *cn1,
 957                                     const struct config_node *cn2,
 958                                     const char *path, const char *fail)
 959 {
 960         const struct config_node *n = _find_first_config_node(cn1, cn2, path);
 961
 962         /* Empty strings are ignored */
 963         if ((n && n->v && n->v->type == CFG_STRING) && (*n->v->v.str)) {
 964                 log_very_verbose("Setting %s to %s", path, n->v->v.str);
 965                 return n->v->v.str;
 966         }
 967
 968         if (fail)
 969                 log_very_verbose("%s not found in config: defaulting to %s",
 970                                  path, fail);
 971         return fail;
 972 }
 973
 974 const char *find_config_str(const struct config_node *cn,
 975                             const char *path, const char *fail)
 976 {
 977         return _find_config_str(cn, NULL, path, fail);
 978 }
 979
 980 static int64_t _find_config_int64(const struct config_node *cn1,
 981                                   const struct config_node *cn2,
 982                                   const char *path, int64_t fail)
 983 {
 984         const struct config_node *n = _find_first_config_node(cn1, cn2, path);
 985
 986         if (n && n->v && n->v->type == CFG_INT) {
 987                 log_very_verbose("Setting %s to %" PRId64, path, n->v->v.i);
 988                 return n->v->v.i;
 989         }
 990
 991         log_very_verbose("%s not found in config: defaulting to %" PRId64,
 992                          path, fail);
 993         return fail;
 994 }
 995
 996 int find_config_int(const struct config_node *cn, const char *path, int fail)
 997 {
 998         /* FIXME Add log_error message on overflow */
 999         return (int) _find_config_int64(cn, NULL, path, (int64_t) fail);
1000 }
1001
1002 static float _find_config_float(const struct config_node *cn1,
1003                                 const struct config_node *cn2,
1004                                 const char *path, float fail)
1005 {
1006         const struct config_node *n = _find_first_config_node(cn1, cn2, path);
1007
1008         if (n && n->v && n->v->type == CFG_FLOAT) {
1009                 log_very_verbose("Setting %s to %f", path, n->v->v.r);
1010                 return n->v->v.r;
1011         }
1012
1013         log_very_verbose("%s not found in config: defaulting to %f",
1014                          path, fail);
1015
1016         return fail;
1017
1018 }
1019
1020 float find_config_float(const struct config_node *cn, const char *path,
1021                         float fail)
1022 {
1023         return _find_config_float(cn, NULL, path, fail);
1024 }
1025
1026 struct config_node *find_config_tree_node(struct cmd_context *cmd,
1027                                           const char *path)
1028 {
1029         return _find_first_config_node(cmd->cft_override ? cmd->cft_override->root : NULL, cmd->cft->root, path);
1030 }
1031
1032 const char *find_config_tree_str(struct cmd_context *cmd,
1033                                  const char *path, const char *fail)
1034 {
1035         return _find_config_str(cmd->cft_override ? cmd->cft_override->root : NULL, cmd->cft->root, path, fail);
1036 }
1037
1038 int find_config_tree_int(struct cmd_context *cmd, const char *path,
1039                          int fail)
1040 {
1041         /* FIXME Add log_error message on overflow */
1042         return (int) _find_config_int64(cmd->cft_override ? cmd->cft_override->root : NULL, cmd->cft->root, path, (int64_t) fail);
1043 }
1044
1045 float find_config_tree_float(struct cmd_context *cmd, const char *path,
1046                              float fail)
1047 {
1048         return _find_config_float(cmd->cft_override ? cmd->cft_override->root : NULL, cmd->cft->root, path, fail);
1049 }
1050
1051 static int _str_in_array(const char *str, const char * const values[])
1052 {
1053         int i;
1054
1055         for (i = 0; values[i]; i++)
1056                 if (!strcasecmp(str, values[i]))
1057                         return 1;
1058
1059         return 0;
1060 }
1061
1062 static int _str_to_bool(const char *str, int fail)
1063 {
1064         const char * const _true_values[]  = { "y", "yes", "on", "true", NULL };
1065         const char * const _false_values[] = { "n", "no", "off", "false", NULL };
1066
1067         if (_str_in_array(str, _true_values))
1068                 return 1;
1069
1070         if (_str_in_array(str, _false_values))
1071                 return 0;
1072
1073         return fail;
1074 }
1075
1076 static int _find_config_bool(const struct config_node *cn1,
1077                              const struct config_node *cn2,
1078                              const char *path, int fail)
1079 {
1080         const struct config_node *n = _find_first_config_node(cn1, cn2, path);
1081         struct config_value *v;
1082
1083         if (!n)
1084                 return fail;
1085
1086         v = n->v;
1087
1088         switch (v->type) {
1089         case CFG_INT:
1090                 return v->v.i ? 1 : 0;
1091
1092         case CFG_STRING:
1093                 return _str_to_bool(v->v.str, fail);
1094         }
1095
1096         return fail;
1097 }
1098
1099 int find_config_bool(const struct config_node *cn, const char *path, int fail)
1100 {
1101         return _find_config_bool(cn, NULL, path, fail);
1102 }
1103
1104 int find_config_tree_bool(struct cmd_context *cmd, const char *path, int fail)
1105 {
1106         return _find_config_bool(cmd->cft_override ? cmd->cft_override->root : NULL, cmd->cft->root, path, fail);
1107 }
1108
1109 int get_config_uint32(const struct config_node *cn, const char *path,
1110                       uint32_t *result)
1111 {
1112         const struct config_node *n;
1113
1114         n = find_config_node(cn, path);
1115
1116         if (!n || !n->v || n->v->type != CFG_INT)
1117                 return 0;
1118
1119         *result = n->v->v.i;
1120         return 1;
1121 }
1122
1123 int get_config_uint64(const struct config_node *cn, const char *path,
1124                       uint64_t *result)
1125 {
1126         const struct config_node *n;
1127
1128         n = find_config_node(cn, path);
1129
1130         if (!n || !n->v || n->v->type != CFG_INT)
1131                 return 0;
1132
1133         *result = (uint64_t) n->v->v.i;
1134         return 1;
1135 }
1136
1137 int get_config_str(const struct config_node *cn, const char *path,
1138                    char **result)
1139 {
1140         const struct config_node *n;
1141
1142         n = find_config_node(cn, path);
1143
1144         if (!n || !n->v || n->v->type != CFG_STRING)
1145                 return 0;
1146
1147         *result = n->v->v.str;
1148         return 1;
1149 }
1150
1151 /* Insert cn2 after cn1 */
1152 static void _insert_config_node(struct config_node **cn1,
1153                                 struct config_node *cn2)
1154 {
1155         if (!*cn1) {
1156                 *cn1 = cn2;
1157                 cn2->sib = NULL;
1158         } else {
1159                 cn2->sib = (*cn1)->sib;
1160                 (*cn1)->sib = cn2;
1161         }
1162 }
1163
1164 /*
1165  * Merge section cn2 into section cn1 (which has the same name)
1166  * overwriting any existing cn1 nodes with matching names.
1167  */
1168 static void _merge_section(struct config_node *cn1, struct config_node *cn2)
1169 {
1170         struct config_node *cn, *nextn, *oldn;
1171         struct config_value *cv;
1172
1173         for (cn = cn2->child; cn; cn = nextn) {
1174                 nextn = cn->sib;
1175
1176                 /* Skip "tags" */
1177                 if (!strcmp(cn->key, "tags"))
1178                         continue;
1179
1180                 /* Subsection? */
1181                 if (!cn->v)
1182                         /* Ignore - we don't have any of these yet */
1183                         continue;
1184                 /* Not already present? */
1185                 if (!(oldn = find_config_node(cn1->child, cn->key))) {
1186                         _insert_config_node(&cn1->child, cn);
1187                         continue;
1188                 }
1189                 /* Merge certain value lists */
1190                 if ((!strcmp(cn1->key, "activation") &&
1191                      !strcmp(cn->key, "volume_list")) ||
1192                     (!strcmp(cn1->key, "devices") &&
1193                      (!strcmp(cn->key, "filter") || !strcmp(cn->key, "types")))) {
1194                         cv = cn->v;
1195                         while (cv->next)
1196                                 cv = cv->next;
1197                         cv->next = oldn->v;
1198                 }
1199
1200                 /* Replace values */
1201                 oldn->v = cn->v;
1202         }
1203 }
1204
1205 static int _match_host_tags(struct dm_list *tags, struct config_node *tn)
1206 {
1207         struct config_value *tv;
1208         const char *str;
1209
1210         for (tv = tn->v; tv; tv = tv->next) {
1211                 if (tv->type != CFG_STRING)
1212                         continue;
1213                 str = tv->v.str;
1214                 if (*str == '@')
1215                         str++;
1216                 if (!*str)
1217                         continue;
1218                 if (str_list_match_item(tags, str))
1219                         return 1;
1220         }
1221
1222         return 0;
1223 }
1224
1225 /* Destructively merge a new config tree into an existing one */
1226 int merge_config_tree(struct cmd_context *cmd, struct config_tree *cft,
1227                       struct config_tree *newdata)
1228 {
1229         struct config_node *root = cft->root;
1230         struct config_node *cn, *nextn, *oldn, *tn, *cn2;
1231
1232         for (cn = newdata->root; cn; cn = nextn) {
1233                 nextn = cn->sib;
1234                 /* Ignore tags section */
1235                 if (!strcmp(cn->key, "tags"))
1236                         continue;
1237                 /* If there's a tags node, skip if host tags don't match */
1238                 if ((tn = find_config_node(cn->child, "tags"))) {
1239                         if (!_match_host_tags(&cmd->tags, tn))
1240                                 continue;
1241                 }
1242                 if (!(oldn = find_config_node(root, cn->key))) {
1243                         _insert_config_node(&cft->root, cn);
1244                         /* Remove any "tags" nodes */
1245                         for (cn2 = cn->child; cn2; cn2 = cn2->sib) {
1246                                 if (!strcmp(cn2->key, "tags")) {
1247                                         cn->child = cn2->sib;
1248                                         continue;
1249                                 }
1250                                 if (cn2->sib && !strcmp(cn2->sib->key, "tags")) {
1251                                         cn2->sib = cn2->sib->sib;
1252                                         continue;
1253                                 }
1254                         }
1255                         continue;
1256                 }
1257                 _merge_section(oldn, cn);
1258         }
1259
1260         return 1;
1261 }
1262
1263 /*
1264  * Convert a token type to the char it represents.
1265  */
1266 static char _token_type_to_char(int type)
1267 {
1268         switch (type) {
1269                 case TOK_SECTION_B:
1270                         return SECTION_B_CHAR;
1271                 case TOK_SECTION_E:
1272                         return SECTION_E_CHAR;
1273                 default:
1274                         return 0;
1275         }
1276 }
1277
1278 /*
1279  * Returns:
1280  *  # of 'type' tokens in 'str'.
1281  */
1282 static unsigned _count_tokens(const char *str, unsigned len, int type)
1283 {
1284         char c;
1285
1286         c = _token_type_to_char(type);
1287
1288         return count_chars(str, len, c);
1289 }
1290
1291 const char *config_parent_name(const struct config_node *n)
1292 {
1293         return (n->parent ? n->parent->key : "(root)");
1294 }
1295 /*
1296  * Heuristic function to make a quick guess as to whether a text
1297  * region probably contains a valid config "section".  (Useful for
1298  * scanning areas of the disk for old metadata.)
1299  * Config sections contain various tokens, may contain other sections
1300  * and strings, and are delimited by begin (type 'TOK_SECTION_B') and
1301  * end (type 'TOK_SECTION_E') tokens.  As a quick heuristic, we just
1302  * count the number of begin and end tokens, and see if they are
1303  * non-zero and the counts match.
1304  * Full validation of the section should be done with another function
1305  * (for example, read_config_fd).
1306  *
1307  * Returns:
1308  *  0 - probably is not a valid config section
1309  *  1 - probably _is_ a valid config section
1310  */
1311 unsigned maybe_config_section(const char *str, unsigned len)
1312 {
1313         int begin_count;
1314         int end_count;
1315
1316         begin_count = _count_tokens(str, len, TOK_SECTION_B);
1317         end_count = _count_tokens(str, len, TOK_SECTION_E);
1318
1319         if (begin_count && end_count && (begin_count == end_count))
1320                 return 1;
1321         else
1322                 return 0;
1323 }
1324
1325 static struct config_value *_clone_config_value(struct dm_pool *mem, const struct config_value *v)
1326 {
1327         if (!v)
1328                 return NULL;
1329         struct config_value *new = _create_value(mem);
1330         new->type = v->type;
1331         if (v->type == CFG_STRING)
1332                 new->v.str = dm_pool_strdup(mem, v->v.str);
1333         else
1334                 new->v = v->v;
1335         new->next = _clone_config_value(mem, v->next);
1336         return new;
1337 }
1338
1339 struct config_node *clone_config_node(struct dm_pool *mem, const struct config_node *cn,
1340                                       int siblings)
1341 {
1342         if (!cn)
1343                 return NULL;
1344         struct config_node *new = _create_node(mem);
1345         new->key = dm_pool_strdup(mem, cn->key);
1346         new->child = clone_config_node(mem, cn->child, 1);
1347         new->v = _clone_config_value(mem, cn->v);
1348         if (siblings)
1349                 new->sib = clone_config_node(mem, cn->sib, siblings);
1350         else
1351                 new->sib = NULL;
1352         return new;
1353 }