metaentry.c

   1 /*
   2  * Various functions to work with meta entries.
   3  *
   4  * Copyright (C) 2007 David Härdeman <david@hardeman.nu>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  */
  19
  20 #define _GNU_SOURCE
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <unistd.h>
  27 #include <sys/xattr.h>
  28 #include <limits.h>
  29 #include <dirent.h>
  30 #include <sys/mman.h>
  31 #include <utime.h>
  32 #include <fcntl.h>
  33 #include <stdint.h>
  34 #include <errno.h>
  35
  36 #include "metastore.h"
  37 #include "metaentry.h"
  38 #include "utils.h"
  39
  40 /* Free's a metaentry and all its parameters */
  41 static void
  42 mentry_free(struct metaentry *m)
  43 {
  44         unsigned i;
  45
  46         if (!m)
  47                 return;
  48
  49         free(m->path);
  50         free(m->owner);
  51         free(m->group);
  52
  53         for (i = 0; i < m->xattrs; i++) {
  54                 free(m->xattr_names[i]);
  55                 free(m->xattr_values[i]);
  56         }
  57
  58         free(m->xattr_names);
  59         free(m->xattr_values);
  60         free(m->xattr_lvalues);
  61
  62         free(m);
  63 }
  64
  65 /* Allocates an empty metahash table */
  66 static struct metahash *
  67 mhash_alloc()
  68 {
  69         struct metahash *mhash;
  70         mhash = xmalloc(sizeof(struct metahash));
  71         memset(mhash, 0, sizeof(struct metahash));
  72         return mhash;
  73 }
  74
  75 /* Generates a hash key (using djb2) */
  76 static unsigned int
  77 hash(const char *str)
  78 {
  79         unsigned int hash = 5381;
  80         int c;
  81
  82         while ((c = *str++))
  83                 hash = ((hash << 5) + hash) + c;
  84
  85         return hash % HASH_INDEXES;
  86 }
  87
  88 /* Allocates an empty metaentry */
  89 static struct metaentry *
  90 mentry_alloc()
  91 {
  92         struct metaentry *mentry;
  93         mentry = xmalloc(sizeof(struct metaentry));
  94         memset(mentry, 0, sizeof(struct metaentry));
  95         return mentry;
  96 }
  97
  98 /* Does a bisect search for the closest match in a metaentry list */
  99 struct metaentry *
 100 mentry_find(const char *path, struct metahash *mhash)
 101 {
 102         struct metaentry *base;
 103         unsigned int key;
 104
 105         if (!mhash) {
 106                 msg(MSG_ERROR, "%s called with empty hash table\n", __FUNCTION__);
 107                 return NULL;
 108         }
 109
 110         key = hash(path);
 111         for (base = mhash->bucket[key]; base; base = base->next) {
 112                 if (!strcmp(base->path, path))
 113                         return base;
 114         }
 115
 116         return NULL;
 117 }
 118
 119 /* Inserts a metaentry into a metaentry list */
 120 static void
 121 mentry_insert(struct metaentry *mentry, struct metahash *mhash)
 122 {
 123         unsigned int key;
 124
 125         key = hash(mentry->path);
 126         mentry->next = mhash->bucket[key];
 127         mhash->bucket[key] = mentry;
 128 }
 129
 130 #ifdef DEBUG
 131 /* Prints a metaentry */
 132 static void
 133 mentry_print(const struct metaentry *mentry)
 134 {
 135         int i;
 136
 137         if (!mentry || !mentry->path) {
 138                 msg(MSG_DEBUG,
 139                     "Incorrect meta entry passed to printmetaentry\n");
 140                 return;
 141         }
 142
 143         msg(MSG_DEBUG, "===========================\n");
 144         msg(MSG_DEBUG, "Dump of metaentry %p\n", mentry);
 145         msg(MSG_DEBUG, "===========================\n");
 146
 147         msg(MSG_DEBUG, "path\t\t: %s\n", mentry->path);
 148         msg(MSG_DEBUG, "owner\t\t: %s\n", mentry->owner);
 149         msg(MSG_DEBUG, "group\t\t: %s\n", mentry->group);
 150         msg(MSG_DEBUG, "mtime\t\t: %ld\n", (unsigned long)mentry->mtime);
 151         msg(MSG_DEBUG, "mtimensec\t: %ld\n", (unsigned long)mentry->mtimensec);
 152         msg(MSG_DEBUG, "mode\t\t: %ld\n", (unsigned long)mentry->mode);
 153         for (i = 0; i < mentry->xattrs; i++) {
 154                 msg(MSG_DEBUG, "xattr[%i]\t: %s=\"", i, mentry->xattr_names[i]);
 155                 binary_print(mentry->xattr_values[i], mentry->xattr_lvalues[i]);
 156                 msg(MSG_DEBUG, "\"\n");
 157         }
 158
 159         msg(MSG_DEBUG, "===========================\n\n");
 160 }
 161
 162 /* Prints all metaentries in a metaentry list */
 163 static void
 164 mentries_print(const struct metahash *mhash)
 165 {
 166         const struct metaentry *mentry;
 167         int index;
 168
 169         for (index = 0; index < HASH_INDEXES; index++)
 170                 for (mentry = mhash->bucket[index]; mentry; mentry = mentry->next)
 171                         mentry_print(mentry);
 172
 173         msg(MSG_DEBUG, "%i entries in total\n", mhash->count);
 174 }
 175 #endif
 176
 177 /* Creates a metaentry for the file/dir/etc at path */
 178 struct metaentry *
 179 mentry_create(const char *path)
 180 {
 181         ssize_t lsize, vsize;
 182         char *list, *attr;
 183         struct stat sbuf;
 184         struct passwd *pbuf;
 185         struct group *gbuf;
 186         int i;
 187         struct metaentry *mentry;
 188
 189         if (lstat(path, &sbuf)) {
 190                 msg(MSG_ERROR, "lstat failed for %s: %s\n",
 191                     path, strerror(errno));
 192                 return NULL;
 193         }
 194
 195         pbuf = xgetpwuid(sbuf.st_uid);
 196         if (!pbuf) {
 197                 msg(MSG_ERROR, "getpwuid failed for %s: uid %i not found\n",
 198                     path, (int)sbuf.st_uid);
 199                 return NULL;
 200         }
 201
 202         gbuf = xgetgrgid(sbuf.st_gid);
 203         if (!gbuf) {
 204                 msg(MSG_ERROR, "getgrgid failed for %s: gid %i not found\n",
 205                     path, (int)sbuf.st_gid);
 206                 return NULL;
 207         }
 208
 209         mentry = mentry_alloc();
 210         mentry->path = xstrdup(path);
 211         mentry->pathlen = strlen(mentry->path);
 212         mentry->owner = xstrdup(pbuf->pw_name);
 213         mentry->group = xstrdup(gbuf->gr_name);
 214         mentry->mode = sbuf.st_mode & 0177777;
 215         mentry->mtime = sbuf.st_mtim.tv_sec;
 216         mentry->mtimensec = sbuf.st_mtim.tv_nsec;
 217
 218         /* symlinks have no xattrs */
 219         if (S_ISLNK(mentry->mode))
 220                 return mentry;
 221
 222         lsize = listxattr(path, NULL, 0);
 223         if (lsize < 0) {
 224                 /* Perhaps the FS doesn't support xattrs? */
 225                 if (errno == ENOTSUP)
 226                         return mentry;
 227
 228                 msg(MSG_ERROR, "listxattr failed for %s: %s\n",
 229                     path, strerror(errno));
 230                 return NULL;
 231         }
 232
 233         list = xmalloc(lsize);
 234         lsize = listxattr(path, list, lsize);
 235         if (lsize < 0) {
 236                 msg(MSG_ERROR, "listxattr failed for %s: %s\n",
 237                     path, strerror(errno));
 238                 free(list);
 239                 return NULL;
 240         }
 241
 242         i = 0;
 243         for (attr = list; attr < list + lsize; attr = strchr(attr, '\0') + 1) {
 244                 if (*attr == '\0')
 245                         continue;
 246                 i++;
 247         }
 248
 249         if (i == 0)
 250                 return mentry;
 251
 252         mentry->xattrs = i;
 253         mentry->xattr_names = xmalloc(i * sizeof(char *));
 254         mentry->xattr_values = xmalloc(i * sizeof(char *));
 255         mentry->xattr_lvalues = xmalloc(i * sizeof(ssize_t));
 256
 257         i = 0;
 258         for (attr = list; attr < list + lsize; attr = strchr(attr, '\0') + 1) {
 259                 if (*attr == '\0')
 260                         continue;
 261
 262                 mentry->xattr_names[i] = xstrdup(attr);
 263                 vsize = getxattr(path, attr, NULL, 0);
 264                 if (vsize < 0) {
 265                         msg(MSG_ERROR, "getxattr failed for %s: %s\n",
 266                             path, strerror(errno));
 267                         free(list);
 268                         mentry_free(mentry);
 269                         return NULL;
 270                 }
 271
 272                 mentry->xattr_lvalues[i] = vsize;
 273                 mentry->xattr_values[i] = xmalloc(vsize);
 274
 275                 vsize = getxattr(path, attr, mentry->xattr_values[i], vsize);
 276                 if (vsize < 0) {
 277                         msg(MSG_ERROR, "getxattr failed for %s: %s\n",
 278                             path, strerror(errno));
 279                         free(list);
 280                         mentry_free(mentry);
 281                         return NULL;
 282                 }
 283                 i++;
 284         }
 285
 286         free(list);
 287         return mentry;
 288 }
 289
 290 /* Cleans up a path and makes it relative to current working dir unless it is absolute */
 291 static char *
 292 normalize_path(const char *orig)
 293 {
 294         char *real = realpath(orig, NULL);
 295         char cwd[PATH_MAX];
 296         char *result;
 297
 298         getcwd(cwd, PATH_MAX);
 299         if (!real)
 300                 return NULL;
 301
 302         if (!strncmp(real, cwd, strlen(cwd))) {
 303                 result = xmalloc(strlen(real) - strlen(cwd) + 1 + 1);
 304                 result[0] = '\0';
 305                 strcat(result, ".");
 306                 strcat(result, real + strlen(cwd));
 307         } else {
 308                 result = xstrdup(real);
 309         }
 310
 311         free(real);
 312         return result;
 313 }
 314
 315 /* Internal function for the recursive path walk */
 316 static void
 317 mentries_recurse(const char *path, struct metahash *mhash, msettings *st)
 318 {
 319         struct stat sbuf;
 320         struct metaentry *mentry;
 321         char tpath[PATH_MAX];
 322         DIR *dir;
 323         struct dirent *dent;
 324
 325         if (!path)
 326                 return;
 327
 328         if (lstat(path, &sbuf)) {
 329                 msg(MSG_ERROR, "lstat failed for %s: %s\n",
 330                     path, strerror(errno));
 331                 return;
 332         }
 333
 334         mentry = mentry_create(path);
 335         if (!mentry)
 336                 return;
 337
 338         mentry_insert(mentry, mhash);
 339
 340         if (S_ISDIR(sbuf.st_mode)) {
 341                 dir = opendir(path);
 342                 if (!dir) {
 343                         msg(MSG_ERROR, "opendir failed for %s: %s\n",
 344                             path, strerror(errno));
 345                         return;
 346                 }
 347
 348                 while ((dent = readdir(dir))) {
 349                         if (!strcmp(dent->d_name, ".") ||
 350                             !strcmp(dent->d_name, "..") ||
 351                             (!st->do_git && !strcmp(dent->d_name, ".git")))
 352                                 continue;
 353                         snprintf(tpath, PATH_MAX, "%s/%s", path, dent->d_name);
 354                         tpath[PATH_MAX - 1] = '\0';
 355                         mentries_recurse(tpath, mhash, st);
 356                 }
 357
 358                 closedir(dir);
 359         }
 360 }
 361
 362 /* Recurses opath and adds metadata entries to the metaentry list */
 363 void
 364 mentries_recurse_path(const char *opath, struct metahash **mhash, msettings *st)
 365 {
 366         char *path = normalize_path(opath);
 367
 368         if (!(*mhash))
 369                 *mhash = mhash_alloc();
 370         mentries_recurse(path, *mhash, st);
 371         free(path);
 372 }
 373
 374 /* Stores metaentries to a file */
 375 void
 376 mentries_tofile(const struct metahash *mhash, const char *path)
 377 {
 378         FILE *to;
 379         const struct metaentry *mentry;
 380         int key;
 381         unsigned i;
 382
 383         to = fopen(path, "w");
 384         if (!to) {
 385                 msg(MSG_CRITICAL, "Failed to open %s: %s\n",
 386                     path, strerror(errno));
 387                 exit(EXIT_FAILURE);
 388         }
 389
 390         write_binary_string(SIGNATURE, SIGNATURELEN, to);
 391         write_binary_string(VERSION, VERSIONLEN, to);
 392
 393         for (key = 0; key < HASH_INDEXES; key++) {
 394                 for (mentry = mhash->bucket[key]; mentry; mentry = mentry->next) {
 395                         write_string(mentry->path, to);
 396                         write_string(mentry->owner, to);
 397                         write_string(mentry->group, to);
 398                         write_int((uint64_t)mentry->mtime, 8, to);
 399                         write_int((uint64_t)mentry->mtimensec, 8, to);
 400                         write_int((uint64_t)mentry->mode, 2, to);
 401                         write_int(mentry->xattrs, 4, to);
 402                         for (i = 0; i < mentry->xattrs; i++) {
 403                                 write_string(mentry->xattr_names[i], to);
 404                                 write_int(mentry->xattr_lvalues[i], 4, to);
 405                                 write_binary_string(mentry->xattr_values[i],
 406                                                     mentry->xattr_lvalues[i], to);
 407                         }
 408                 }
 409         }
 410
 411         fclose(to);
 412 }
 413
 414 /* Creates a metaentry list from a file */
 415 void
 416 mentries_fromfile(struct metahash **mhash, const char *path)
 417 {
 418         struct metaentry *mentry;
 419         char *mmapstart;
 420         char *ptr;
 421         char *max;
 422         int fd;
 423         struct stat sbuf;
 424         unsigned i;
 425
 426         if (!(*mhash))
 427                 *mhash = mhash_alloc();
 428
 429         fd = open(path, O_RDONLY);
 430         if (fd < 0) {
 431                 msg(MSG_CRITICAL, "Failed to open %s: %s\n",
 432                     path, strerror(errno));
 433                 exit(EXIT_FAILURE);
 434         }
 435
 436         if (fstat(fd, &sbuf)) {
 437                 msg(MSG_CRITICAL, "Failed to stat %s: %s\n",
 438                     path, strerror(errno));
 439                 exit(EXIT_FAILURE);
 440         }
 441
 442         if (sbuf.st_size < (SIGNATURELEN + VERSIONLEN)) {
 443                 msg(MSG_CRITICAL, "File %s has an invalid size\n", path);
 444                 exit(EXIT_FAILURE);
 445         }
 446
 447         mmapstart = mmap(NULL, (size_t)sbuf.st_size, PROT_READ,
 448                          MAP_SHARED, fd, 0);
 449         if (mmapstart == MAP_FAILED) {
 450                 msg(MSG_CRITICAL, "Unable to mmap %s: %s\n",
 451                     path, strerror(errno));
 452                 exit(EXIT_FAILURE);
 453         }
 454         ptr = mmapstart;
 455         max = mmapstart + sbuf.st_size;
 456
 457         if (strncmp(ptr, SIGNATURE, SIGNATURELEN)) {
 458                 msg(MSG_CRITICAL, "Invalid signature for file %s\n", path);
 459                 goto out;
 460         }
 461         ptr += SIGNATURELEN;
 462
 463         if (strncmp(ptr, VERSION, VERSIONLEN)) {
 464                 msg(MSG_CRITICAL, "Invalid version of file %s\n", path);
 465                 goto out;
 466         }
 467         ptr += VERSIONLEN;
 468
 469         while (ptr < mmapstart + sbuf.st_size) {
 470                 if (*ptr == '\0') {
 471                         msg(MSG_CRITICAL, "Invalid characters in file %s\n",
 472                             path);
 473                         goto out;
 474                 }
 475
 476                 mentry = mentry_alloc();
 477                 mentry->path = read_string(&ptr, max);
 478                 mentry->pathlen = strlen(mentry->path);
 479                 mentry->owner = read_string(&ptr, max);
 480                 mentry->group = read_string(&ptr, max);
 481                 mentry->mtime = (time_t)read_int(&ptr, 8, max);
 482                 mentry->mtimensec = (time_t)read_int(&ptr, 8, max);
 483                 mentry->mode = (mode_t)read_int(&ptr, 2, max);
 484                 mentry->xattrs = (unsigned int)read_int(&ptr, 4, max);
 485
 486                 if (!mentry->xattrs) {
 487                         mentry_insert(mentry, *mhash);
 488                         continue;
 489                 }
 490
 491                 mentry->xattr_names = xmalloc(mentry->xattrs *
 492                                       sizeof(char *));
 493                 mentry->xattr_lvalues = xmalloc(mentry->xattrs *
 494                                         sizeof(int));
 495                 mentry->xattr_values = xmalloc(mentry->xattrs *
 496                                        sizeof(char *));
 497
 498                 for (i = 0; i < mentry->xattrs; i++) {
 499                         mentry->xattr_names[i] = read_string(&ptr, max);
 500                         mentry->xattr_lvalues[i] =
 501                                 (int)read_int(&ptr, 4, max);
 502                         mentry->xattr_values[i] =
 503                                 read_binary_string(&ptr,
 504                                                    mentry->xattr_lvalues[i],
 505                                                    max);
 506                 }
 507                 mentry_insert(mentry, *mhash);
 508         }
 509
 510 out:
 511         munmap(mmapstart, sbuf.st_size);
 512         close(fd);
 513 }
 514
 515 /* Searches haystack for an xattr matching xattr number n in needle */
 516 int
 517 mentry_find_xattr(struct metaentry *haystack, struct metaentry *needle,
 518                   unsigned n)
 519 {
 520         unsigned i;
 521
 522         for (i = 0; i < haystack->xattrs; i++) {
 523                 if (strcmp(haystack->xattr_names[i], needle->xattr_names[n]))
 524                         continue;
 525                 if (haystack->xattr_lvalues[i] != needle->xattr_lvalues[n])
 526                         return -1;
 527                 if (bcmp(haystack->xattr_values[i], needle->xattr_values[n],
 528                          needle->xattr_lvalues[n]))
 529                         return -1;
 530                 return i;
 531         }
 532         return -1;
 533 }
 534
 535 /* Returns zero if all xattrs in left and right match */
 536 static int
 537 mentry_compare_xattr(struct metaentry *left, struct metaentry *right)
 538 {
 539         unsigned i;
 540
 541         if (left->xattrs != right->xattrs)
 542                 return 1;
 543
 544         /* Make sure all xattrs in left are found in right and vice versa */
 545         for (i = 0; i < left->xattrs; i++) {
 546                 if (mentry_find_xattr(right, left, i) < 0 ||
 547                     mentry_find_xattr(left, right, i) < 0) {
 548                         return 1;
 549                 }
 550         }
 551
 552         return 0;
 553 }
 554
 555 /* Compares two metaentries and returns an int with a bitmask of differences */
 556 int
 557 mentry_compare(struct metaentry *left, struct metaentry *right, msettings *st)
 558 {
 559         int retval = DIFF_NONE;
 560
 561         if (!left || !right) {
 562                 msg(MSG_ERROR, "%s called with empty list\n", __FUNCTION__);
 563                 return -1;
 564         }
 565
 566         if (strcmp(left->path, right->path))
 567                 return -1;
 568
 569         if (strcmp(left->owner, right->owner))
 570                 retval |= DIFF_OWNER;
 571
 572         if (strcmp(left->group, right->group))
 573                 retval |= DIFF_GROUP;
 574
 575         if ((left->mode & 07777) != (right->mode & 07777))
 576                 retval |= DIFF_MODE;
 577
 578         if ((left->mode & S_IFMT) != (right->mode & S_IFMT))
 579                 retval |= DIFF_TYPE;
 580
 581         if (st->do_mtime && strcmp(left->path, st->metafile) &&
 582             (left->mtime != right->mtime ||
 583              left->mtimensec != right->mtimensec))
 584                 retval |= DIFF_MTIME;
 585
 586         if (mentry_compare_xattr(left, right)) {
 587                 retval |= DIFF_XATTR;
 588                 return retval;
 589         }
 590
 591         return retval;
 592 }
 593
 594 /* Compares lists of real and stored metadata and calls pfunc for each */
 595 void
 596 mentries_compare(struct metahash *mhashreal,
 597                  struct metahash *mhashstored,
 598                  void (*pfunc)
 599                  (struct metaentry *real, struct metaentry *stored, int cmp),
 600                  msettings *st)
 601 {
 602         struct metaentry *real, *stored;
 603         int key;
 604
 605         if (!mhashreal || !mhashstored) {
 606                 msg(MSG_ERROR, "%s called with empty list\n", __FUNCTION__);
 607                 return;
 608         }
 609
 610         for (key = 0; key < HASH_INDEXES; key++) {
 611                 for (real = mhashreal->bucket[key]; real; real = real->next) {
 612                         stored = mentry_find(real->path, mhashstored);
 613
 614                         if (!stored)
 615                                 pfunc(real, NULL, DIFF_ADDED);
 616                         else
 617                                 pfunc(real, stored, mentry_compare(real, stored, st));
 618                 }
 619
 620                 for (stored = mhashstored->bucket[key]; stored; stored = stored->next) {
 621                         real = mentry_find(stored->path, mhashreal);
 622
 623                         if (!real)
 624                                 pfunc(NULL, stored, DIFF_DELE);
 625                 }
 626         }
 627 }
 628