lib.c

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2011  Neil Brown <neilb@suse.de>
   5  *
   6  *
   7  *    This program is free software; you can redistribute it and/or modify
   8  *    it under the terms of the GNU General Public License as published by
   9  *    the Free Software Foundation; either version 2 of the License, or
  10  *    (at your option) any later version.
  11  *
  12  *    This program is distributed in the hope that it will be useful,
  13  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *    GNU General Public License for more details.
  16  *
  17  *    You should have received a copy of the GNU General Public License
  18  *    along with this program; if not, write to the Free Software
  19  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  *    Author: Neil Brown
  22  *    Email: <neilb@suse.de>
  23  */
  24
  25 #include        "mdadm.h"
  26 #include        "dlink.h"
  27 #include        <ctype.h>
  28 #include        <limits.h>
  29
  30 /**
  31  * is_string_lq() - Check if string length with NULL byte is lower or equal to requested.
  32  * @str: string to check.
  33  * @max_len: max length.
  34  *
  35  * @str length must be bigger than 0 and be lower or equal @max_len, including termination byte.
  36  */
  37 bool is_string_lq(const char * const str, size_t max_len)
  38 {
  39         assert(str);
  40
  41         size_t _len = strnlen(str, max_len);
  42
  43         if (_len > 0 && _len < max_len)
  44                 return true;
  45         return false;
  46 }
  47
  48 bool is_dev_alive(char *path)
  49 {
  50         if (!path)
  51                 return false;
  52
  53         if (access(path, R_OK) == 0)
  54                 return true;
  55
  56         return false;
  57 }
  58
  59 /* This fill contains various 'library' style function.  They
  60  * have no dependency on anything outside this file.
  61  */
  62
  63 int get_mdp_major(void)
  64 {
  65         static int mdp_major = -1;
  66         FILE *fl;
  67         char *w;
  68         int have_block = 0;
  69         int have_devices = 0;
  70         int last_num = -1;
  71
  72         if (mdp_major != -1)
  73                 return mdp_major;
  74
  75         fl = fopen("/proc/devices", "r");
  76         if (!fl)
  77                 return -1;
  78
  79         while ((w = conf_word(fl, 1))) {
  80                 if (have_block && strcmp(w, "devices:") == 0)
  81                         have_devices = 1;
  82                 have_block =  (strcmp(w, "Block") == 0);
  83                 if (isdigit(w[0]))
  84                         last_num = atoi(w);
  85                 if (have_devices && strcmp(w, "mdp") == 0)
  86                         mdp_major = last_num;
  87                 free(w);
  88         }
  89         fclose(fl);
  90
  91         return mdp_major;
  92 }
  93
  94 char *devid2kname(dev_t devid)
  95 {
  96         char path[30];
  97         char link[PATH_MAX];
  98         static char devnm[32];
  99         char *cp;
 100         int n;
 101
 102         /* Look at the
 103          * /sys/dev/block/%d:%d link which must look like
 104          * and take the last component.
 105          */
 106         sprintf(path, "/sys/dev/block/%d:%d", major(devid), minor(devid));
 107         n = readlink(path, link, sizeof(link) - 1);
 108         if (n > 0) {
 109                 link[n] = 0;
 110                 cp = strrchr(link, '/');
 111                 if (cp) {
 112                         strcpy(devnm, cp + 1);
 113                         return devnm;
 114                 }
 115         }
 116         return NULL;
 117 }
 118
 119 char *stat2kname(struct stat *st)
 120 {
 121         if ((S_IFMT & st->st_mode) != S_IFBLK)
 122                 return NULL;
 123
 124         return devid2kname(st->st_rdev);
 125 }
 126
 127 char *fd2kname(int fd)
 128 {
 129         struct stat stb;
 130
 131         if (fstat(fd, &stb) == 0)
 132                 return stat2kname(&stb);
 133
 134         return NULL;
 135 }
 136
 137 char *devid2devnm(dev_t devid)
 138 {
 139         char path[30];
 140         char link[200];
 141         static char devnm[32];
 142         char *cp, *ep;
 143         int n;
 144
 145         /* Might be an extended-minor partition or a
 146          * named md device. Look at the
 147          * /sys/dev/block/%d:%d link which must look like
 148          *    ../../block/mdXXX/mdXXXpYY
 149          * or
 150          *    ...../block/md_FOO
 151          */
 152         sprintf(path, "/sys/dev/block/%d:%d", major(devid), minor(devid));
 153         n = readlink(path, link, sizeof(link) - 1);
 154         if (n > 0) {
 155                 link[n] = 0;
 156                 cp = strstr(link, "/block/");
 157                 if (cp) {
 158                         cp += 7;
 159                         ep = strchr(cp, '/');
 160                         if (ep)
 161                                 *ep = 0;
 162                         strcpy(devnm, cp);
 163                         return devnm;
 164                 }
 165         }
 166         if (major(devid) == MD_MAJOR)
 167                 sprintf(devnm,"md%d", minor(devid));
 168         else if (major(devid) == (unsigned)get_mdp_major())
 169                 sprintf(devnm,"md_d%d",
 170                         (minor(devid)>>MdpMinorShift));
 171         else
 172                 return NULL;
 173
 174         return devnm;
 175 }
 176
 177 char *stat2devnm(struct stat *st)
 178 {
 179         if ((S_IFMT & st->st_mode) != S_IFBLK)
 180                 return NULL;
 181
 182         return devid2devnm(st->st_rdev);
 183 }
 184
 185 bool stat_is_md_dev(struct stat *st)
 186 {
 187         if ((S_IFMT & st->st_mode) != S_IFBLK)
 188                 return false;
 189         if (major(st->st_rdev) == MD_MAJOR)
 190                 return true;
 191         if (major(st->st_rdev) == (unsigned)get_mdp_major())
 192                 return true;
 193
 194         return false;
 195 }
 196
 197 char *fd2devnm(int fd)
 198 {
 199         struct stat stb;
 200
 201         if (fstat(fd, &stb) == 0)
 202                 return stat2devnm(&stb);
 203
 204         return NULL;
 205 }
 206
 207 /*
 208  * convert a major/minor pair for a block device into a name in /dev, if possible.
 209  * On the first call, walk /dev collecting name.
 210  * Put them in a simple linked listfor now.
 211  */
 212 struct devmap {
 213         int major, minor;
 214         char *name;
 215         struct devmap *next;
 216 } *devlist = NULL;
 217 int devlist_ready = 0;
 218
 219 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 220 {
 221         struct stat st;
 222
 223         if (S_ISLNK(stb->st_mode)) {
 224                 if (stat(name, &st) != 0)
 225                         return 0;
 226                 stb = &st;
 227         }
 228
 229         if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 230                 char *n = xstrdup(name);
 231                 struct devmap *dm = xmalloc(sizeof(*dm));
 232                 if (strncmp(n, "/dev/./", 7) == 0)
 233                         strcpy(n + 4, name + 6);
 234                 if (dm) {
 235                         dm->major = major(stb->st_rdev);
 236                         dm->minor = minor(stb->st_rdev);
 237                         dm->name = n;
 238                         dm->next = devlist;
 239                         devlist = dm;
 240                 }
 241         }
 242
 243         return 0;
 244 }
 245
 246 #ifndef HAVE_NFTW
 247 #ifdef HAVE_FTW
 248 int add_dev_1(const char *name, const struct stat *stb, int flag)
 249 {
 250         return add_dev(name, stb, flag, NULL);
 251 }
 252 int nftw(const char *path,
 253          int (*han)(const char *name, const struct stat *stb,
 254                     int flag, struct FTW *s), int nopenfd, int flags)
 255 {
 256         return ftw(path, add_dev_1, nopenfd);
 257 }
 258 #else
 259 int nftw(const char *path,
 260          int (*han)(const char *name, const struct stat *stb,
 261                     int flag, struct FTW *s), int nopenfd, int flags)
 262 {
 263         return 0;
 264 }
 265 #endif /* HAVE_FTW */
 266 #endif /* HAVE_NFTW */
 267
 268 /*
 269  * Find a block device with the right major/minor number.
 270  * If we find multiple names, choose the shortest.
 271  * If we find a name in /dev/md/, we prefer that.
 272  * This applies only to names for MD devices.
 273  * If 'prefer' is set (normally to e.g. /by-path/)
 274  * then we prefer a name which contains that string.
 275  */
 276 char *map_dev_preferred(int major, int minor, int create,
 277                         char *prefer)
 278 {
 279         struct devmap *p;
 280         char *regular = NULL, *preferred=NULL;
 281         int did_check = 0;
 282
 283         if (major == 0 && minor == 0)
 284                 return NULL;
 285
 286  retry:
 287         if (!devlist_ready) {
 288                 char *dev = "/dev";
 289                 struct stat stb;
 290                 while(devlist) {
 291                         struct devmap *d = devlist;
 292                         devlist = d->next;
 293                         free(d->name);
 294                         free(d);
 295                 }
 296                 if (lstat(dev, &stb) == 0 && S_ISLNK(stb.st_mode))
 297                         dev = "/dev/.";
 298                 nftw(dev, add_dev, 10, FTW_PHYS);
 299                 devlist_ready=1;
 300                 did_check = 1;
 301         }
 302
 303         for (p = devlist; p; p = p->next)
 304                 if (p->major == major && p->minor == minor) {
 305                         if (strncmp(p->name, DEV_MD_DIR, DEV_MD_DIR_LEN) == 0 ||
 306                             (prefer && strstr(p->name, prefer))) {
 307                                 if (preferred == NULL ||
 308                                     strlen(p->name) < strlen(preferred))
 309                                         preferred = p->name;
 310                         } else {
 311                                 if (regular == NULL ||
 312                                     strlen(p->name) < strlen(regular))
 313                                         regular = p->name;
 314                         }
 315                 }
 316         if (!regular && !preferred && !did_check) {
 317                 devlist_ready = 0;
 318                 goto retry;
 319         }
 320         if (create && !regular && !preferred) {
 321                 static char buf[30];
 322                 snprintf(buf, sizeof(buf), "%d:%d", major, minor);
 323                 regular = buf;
 324         }
 325
 326         return preferred ? preferred : regular;
 327 }
 328
 329 /* conf_word gets one word from the conf file.
 330  * if "allow_key", then accept words at the start of a line,
 331  * otherwise stop when such a word is found.
 332  * We assume that the file pointer is at the end of a word, so the
 333  * next character is a space, or a newline.  If not, it is the start of a line.
 334  */
 335
 336 char *conf_word(FILE *file, int allow_key)
 337 {
 338         int wsize = 100;
 339         int len = 0;
 340         int c;
 341         int quote;
 342         int wordfound = 0;
 343         char *word = xmalloc(wsize);
 344
 345         while (wordfound == 0) {
 346                 /* at the end of a word.. */
 347                 c = getc(file);
 348                 if (c == '#')
 349                         while (c != EOF && c != '\n')
 350                                 c = getc(file);
 351                 if (c == EOF)
 352                         break;
 353                 if (c == '\n')
 354                         continue;
 355
 356                 if (c != ' ' && c != '\t' && ! allow_key) {
 357                         ungetc(c, file);
 358                         break;
 359                 }
 360                 /* looks like it is safe to get a word here, if there is one */
 361                 quote = 0;
 362                 /* first, skip any spaces */
 363                 while (c == ' ' || c == '\t')
 364                         c = getc(file);
 365                 if (c != EOF && c != '\n' && c != '#') {
 366                         /* we really have a character of a word, so start saving it */
 367                         while (c != EOF && c != '\n' &&
 368                                (quote || (c != ' ' && c != '\t'))) {
 369                                 wordfound = 1;
 370                                 if (quote && c == quote)
 371                                         quote = 0;
 372                                 else if (quote == 0 && (c == '\'' || c == '"'))
 373                                         quote = c;
 374                                 else {
 375                                         if (len == wsize-1) {
 376                                                 wsize += 100;
 377                                                 word = xrealloc(word, wsize);
 378                                         }
 379                                         word[len++] = c;
 380                                 }
 381                                 c = getc(file);
 382                                 /* Hack for broken kernels (2.6.14-.24) that put
 383                                  *        "active(auto-read-only)"
 384                                  * in /proc/mdstat instead of
 385                                  *        "active (auto-read-only)"
 386                                  */
 387                                 if (c == '(' && len >= 6 &&
 388                                     strncmp(word + len - 6, "active", 6) == 0)
 389                                         c = ' ';
 390                         }
 391                 }
 392                 if (c != EOF)
 393                         ungetc(c, file);
 394         }
 395         word[len] = 0;
 396
 397         /* Further HACK for broken kernels.. 2.6.14-2.6.24 */
 398         if (strcmp(word, "auto-read-only)") == 0)
 399                 strcpy(word, "(auto-read-only)");
 400
 401 /*    printf("word is <%s>\n", word); */
 402         if (!wordfound) {
 403                 free(word);
 404                 word = NULL;
 405         }
 406         return word;
 407 }
 408
 409 void print_quoted(char *str)
 410 {
 411         /* Printf the string with surrounding quotes
 412          * iff needed.
 413          * If no space, tab, or quote - leave unchanged.
 414          * Else print surrounded by " or ', swapping quotes
 415          * when we find one that will cause confusion.
 416          */
 417
 418         char first_quote = 0, q;
 419         char *c;
 420
 421         for (c = str; *c; c++) {
 422                 switch(*c) {
 423                 case '\'':
 424                 case '"':
 425                         first_quote = *c;
 426                         break;
 427                 case ' ':
 428                 case '\t':
 429                         first_quote = *c;
 430                         continue;
 431                 default:
 432                         continue;
 433                 }
 434                 break;
 435         }
 436         if (!first_quote) {
 437                 printf("%s", str);
 438                 return;
 439         }
 440
 441         if (first_quote == '"')
 442                 q = '\'';
 443         else
 444                 q = '"';
 445         putchar(q);
 446         for (c = str; *c; c++) {
 447                 if (*c == q) {
 448                         putchar(q);
 449                         q ^= '"' ^ '\'';
 450                         putchar(q);
 451                 }
 452                 putchar(*c);
 453         }
 454         putchar(q);
 455 }
 456
 457 /**
 458  * is_alphanum() - Check if sign is letter or digit.
 459  * @c: char to analyze.
 460  *
 461  * Similar to isalnum() but additional locales are excluded.
 462  *
 463  * Return: %true on success, %false otherwise.
 464  */
 465 bool is_alphanum(const char c)
 466 {
 467         if (isupper(c) || islower(c) || isdigit(c) != 0)
 468                 return true;
 469         return false;
 470 }
 471
 472 /**
 473  * is_name_posix_compatible() - Check if name is POSIX compatible.
 474  * @name: name to check.
 475  *
 476  *  POSIX portable file name character set contains ASCII letters,
 477  *  digits, '_', '.', and '-'. Also forbid leading '-'.
 478  *  The length of the name cannot exceed NAME_MAX - 1 (ensure NULL ending).
 479  *
 480  * Return: %true on success, %false otherwise.
 481  */
 482 bool is_name_posix_compatible(const char * const name)
 483 {
 484         assert(name);
 485
 486         char allowed_symbols[] = "-_.";
 487         const char *n = name;
 488
 489         if (!is_string_lq(name, NAME_MAX))
 490                 return false;
 491
 492         if (*n == '-')
 493                 return false;
 494
 495         while (*n != '\0') {
 496                 if (!is_alphanum(*n) && !strchr(allowed_symbols, *n))
 497                         return false;
 498                 n++;
 499         }
 500         return true;
 501 }
 502
 503 int check_env(char *name)
 504 {
 505         char *val = getenv(name);
 506
 507         if (val && atoi(val) == 1)
 508                 return 1;
 509
 510         return 0;
 511 }
 512
 513 unsigned long GCD(unsigned long a, unsigned long b)
 514 {
 515         while (a != b) {
 516                 if (a < b)
 517                         b -= a;
 518                 if (b < a)
 519                         a -= b;
 520         }
 521         return a;
 522 }
 523
 524 /*
 525  * conf_line reads one logical line from the conffile or mdstat.
 526  * It skips comments and continues until it finds a line that starts
 527  * with a non blank/comment.  This character is pushed back for the next call
 528  * A doubly linked list of words is returned.
 529  * the first word will be a keyword.  Other words will have had quotes removed.
 530  */
 531
 532 char *conf_line(FILE *file)
 533 {
 534         char *w;
 535         char *list;
 536
 537         w = conf_word(file, 1);
 538         if (w == NULL)
 539                 return NULL;
 540
 541         list = dl_strdup(w);
 542         free(w);
 543         dl_init(list);
 544
 545         while ((w = conf_word(file, 0))){
 546                 char *w2 = dl_strdup(w);
 547                 free(w);
 548                 dl_add(list, w2);
 549         }
 550 /*    printf("got a line\n");*/
 551         return list;
 552 }
 553
 554 void free_line(char *line)
 555 {
 556         char *w;
 557         for (w = dl_next(line); w != line; w = dl_next(line)) {
 558                 dl_del(w);
 559                 dl_free(w);
 560         }
 561         dl_free(line);
 562 }
 563
 564 /**
 565  * parse_num() - Parse int from string.
 566  * @dest: Pointer to destination.
 567  * @num: Pointer to string that is going to be parsed.
 568  *
 569  * If string contains anything after a number, error code is returned.
 570  * The same happens when number is bigger than INT_MAX or smaller than 0.
 571  * Writes to destination only if successfully read the number.
 572  *
 573  * Return: 0 on success, 1 otherwise.
 574  */
 575 int parse_num(int *dest, const char *num)
 576 {
 577         char *c = NULL;
 578         long temp;
 579
 580         if (!num)
 581                 return 1;
 582
 583         errno = 0;
 584         temp = strtol(num, &c, 10);
 585         if (temp < 0 || temp > INT_MAX || *c || errno != 0 || num == c)
 586                 return 1;
 587         *dest = temp;
 588         return 0;
 589 }
 590
 591 /**
 592  * s_gethostname() - secure get hostname. Assure null-terminated string.
 593  *
 594  * @buf: buffer for hostname.
 595  * @buf_len: buffer length.
 596  *
 597  * Return: gethostname() result.
 598  */
 599 int s_gethostname(char *buf, int buf_len)
 600 {
 601         assert(buf);
 602
 603         int ret = gethostname(buf, buf_len);
 604
 605         buf[buf_len - 1] = 0;
 606
 607         return ret;
 608 }