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
  21 #define _GNU_SOURCE
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <unistd.h>
  28 #include <attr/xattr.h>
  29 #include <limits.h>
  30 #include <dirent.h>
  31 #include <sys/mman.h>
  32 #include <utime.h>
  33 #include <fcntl.h>
  34 #include <stdint.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         int 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[i]; 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 static 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 %i: %s\n",
 198                     (int)sbuf.st_uid, strerror(errno));
 199                 return NULL;
 200         }
 201
 202         gbuf = xgetgrgid(sbuf.st_gid);
 203         if (!gbuf) {
 204                 msg(MSG_ERROR, "getgrgid failed for %i: %s\n",
 205                     (int)sbuf.st_gid, strerror(errno));
 206                 return NULL;
 207         }
 208
 209         mentry = mentry_alloc();
 210         mentry->path = xstrdup(path);
 211         mentry->owner = xstrdup(pbuf->pw_name);
 212         mentry->group = xstrdup(gbuf->gr_name);
 213         mentry->mode = sbuf.st_mode & 0177777;
 214         mentry->mtime = sbuf.st_mtim.tv_sec;
 215         mentry->mtimensec = sbuf.st_mtim.tv_nsec;
 216
 217         /* symlinks have no xattrs */
 218         if (S_ISLNK(mentry->mode))
 219                 return mentry;
 220
 221         lsize = listxattr(path, NULL, 0);
 222         if (lsize < 0) {
 223                 msg(MSG_ERROR, "listxattr failed for %s: %s\n",
 224                     path, strerror(errno));
 225                 return NULL;
 226         }
 227
 228         list = xmalloc(lsize);
 229         lsize = listxattr(path, list, lsize);
 230         if (lsize < 0) {
 231                 msg(MSG_ERROR, "listxattr failed for %s: %s\n",
 232                     path, strerror(errno));
 233                 free(list);
 234                 return NULL;
 235         }
 236
 237         i = 0;
 238         for (attr = list; attr < list + lsize; attr = strchr(attr, '\0') + 1) {
 239                 if (*attr == '\0')
 240                         continue;
 241                 i++;
 242         }
 243
 244         if (i == 0)
 245                 return mentry;
 246
 247         mentry->xattrs = i;
 248         mentry->xattr_names = xmalloc(i * sizeof(char *));
 249         mentry->xattr_values = xmalloc(i * sizeof(char *));
 250         mentry->xattr_lvalues = xmalloc(i * sizeof(ssize_t));
 251
 252         i = 0;
 253         for (attr = list; attr < list + lsize; attr = strchr(attr, '\0') + 1) {
 254                 if (*attr == '\0')
 255                         continue;
 256
 257                 mentry->xattr_names[i] = xstrdup(attr);
 258                 vsize = getxattr(path, attr, NULL, 0);
 259                 if (vsize < 0) {
 260                         msg(MSG_ERROR, "getxattr failed for %s: %s\n",
 261                             path, strerror(errno));
 262                         free(list);
 263                         mentry_free(mentry);
 264                         return NULL;
 265                 }
 266
 267                 mentry->xattr_lvalues[i] = vsize;
 268                 mentry->xattr_values[i] = xmalloc(vsize);
 269
 270                 vsize = getxattr(path, attr, mentry->xattr_values[i], vsize);
 271                 if (vsize < 0) {
 272                         msg(MSG_ERROR, "getxattr failed for %s: %s\n",
 273                             path, strerror(errno));
 274                         free(list);
 275                         mentry_free(mentry);
 276                         return NULL;
 277                 }
 278                 i++;
 279         }
 280
 281         free(list);
 282         return mentry;
 283 }
 284
 285 /* Cleans up a path and makes it relative to current working dir unless it is absolute */
 286 static char *
 287 normalize_path(const char *orig)
 288 {
 289         char *real = canonicalize_file_name(orig);
 290         char cwd[PATH_MAX];
 291         char *result;
 292
 293         getcwd(cwd, PATH_MAX);
 294         if (!real)
 295                 return NULL;
 296
 297         if (!strncmp(real, cwd, strlen(cwd))) {
 298                 result = xmalloc(strlen(real) - strlen(cwd) + 1 + 1);
 299                 result[0] = '\0';
 300                 strcat(result, ".");
 301                 strcat(result, real + strlen(cwd));
 302         } else {
 303                 result = xstrdup(real);
 304         }
 305
 306         free(real);
 307         return result;
 308 }
 309
 310 /* Internal function for the recursive path walk */
 311 static void
 312 mentries_recurse(const char *path, struct metahash *mhash)
 313 {
 314         struct stat sbuf;
 315         struct metaentry *mentry;
 316         char tpath[PATH_MAX];
 317         DIR *dir;
 318         struct dirent *dent;
 319
 320         if (!path)
 321                 return;
 322
 323         if (lstat(path, &sbuf)) {
 324                 msg(MSG_ERROR, "lstat failed for %s: %s\n",
 325                     path, strerror(errno));
 326                 return;
 327         }
 328
 329         mentry = mentry_create(path);
 330         if (!mentry)
 331                 return;
 332
 333         mentry_insert(mentry, mhash);
 334
 335         if (S_ISDIR(sbuf.st_mode)) {
 336                 dir = opendir(path);
 337                 if (!dir) {
 338                         msg(MSG_ERROR, "opendir failed for %s: %s\n",
 339                             path, strerror(errno));
 340                         return;
 341                 }
 342
 343                 while ((dent = readdir(dir))) {
 344                         if (!strcmp(dent->d_name, ".") ||
 345                             !strcmp(dent->d_name, "..") ||
 346                             !strcmp(dent->d_name, ".git"))
 347                                 continue;
 348                         snprintf(tpath, PATH_MAX, "%s/%s", path, dent->d_name);
 349                         tpath[PATH_MAX - 1] = '\0';
 350                         mentries_recurse(tpath, mhash);
 351                 }
 352
 353                 closedir(dir);
 354         }
 355 }
 356
 357 /* Recurses opath and adds metadata entries to the metaentry list */
 358 void
 359 mentries_recurse_path(const char *opath, struct metahash **mhash)
 360 {
 361         char *path = normalize_path(opath);
 362
 363         if (!(*mhash))
 364                 *mhash = mhash_alloc();
 365         mentries_recurse(path, *mhash);
 366         free(path);
 367 }
 368
 369 /* Stores metaentries to a file */
 370 void
 371 mentries_tofile(const struct metahash *mhash, const char *path)
 372 {
 373         FILE *to;
 374         const struct metaentry *mentry;
 375         int key, i;
 376
 377         to = fopen(path, "w");
 378         if (!to) {
 379                 msg(MSG_CRITICAL, "Failed to open %s: %s\n",
 380                     path, strerror(errno));
 381                 exit(EXIT_FAILURE);
 382         }
 383
 384         write_binary_string(SIGNATURE, SIGNATURELEN, to);
 385         write_binary_string(VERSION, VERSIONLEN, to);
 386
 387         for (key = 0; key < HASH_INDEXES; key++) {
 388                 for (mentry = mhash->bucket[key]; mentry; mentry = mentry->next) {
 389                         write_string(mentry->path, to);
 390                         write_string(mentry->owner, to);
 391                         write_string(mentry->group, to);
 392                         write_int((uint64_t)mentry->mtime, 8, to);
 393                         write_int((uint64_t)mentry->mtimensec, 8, to);
 394                         write_int((uint64_t)mentry->mode, 2, to);
 395                         write_int(mentry->xattrs, 4, to);
 396                         for (i = 0; i < mentry->xattrs; i++) {
 397                                 write_string(mentry->xattr_names[i], to);
 398                                 write_int(mentry->xattr_lvalues[i], 4, to);
 399                                 write_binary_string(mentry->xattr_values[i],
 400                                                     mentry->xattr_lvalues[i], to);
 401                         }
 402                 }
 403         }
 404
 405         fclose(to);
 406 }
 407
 408 /* Creates a metaentry list from a file */
 409 void
 410 mentries_fromfile(struct metahash **mhash, const char *path)
 411 {
 412         struct metaentry *mentry;
 413         char *mmapstart;
 414         char *ptr;
 415         char *max;
 416         int fd;
 417         struct stat sbuf;
 418         int i;
 419
 420         if (!(*mhash))
 421                 *mhash = mhash_alloc();
 422
 423         fd = open(path, O_RDONLY);
 424         if (fd < 0) {
 425                 msg(MSG_CRITICAL, "Failed to open %s: %s\n",
 426                     path, strerror(errno));
 427                 exit(EXIT_FAILURE);
 428         }
 429
 430         if (fstat(fd, &sbuf)) {
 431                 msg(MSG_CRITICAL, "Failed to stat %s: %s\n",
 432                     path, strerror(errno));
 433                 exit(EXIT_FAILURE);
 434         }
 435
 436         if (sbuf.st_size < (SIGNATURELEN + VERSIONLEN)) {
 437                 msg(MSG_CRITICAL, "File %s has an invalid size\n", path);
 438                 exit(EXIT_FAILURE);
 439         }
 440
 441         mmapstart = mmap(NULL, (size_t)sbuf.st_size, PROT_READ,
 442                          MAP_SHARED, fd, 0);
 443         if (mmapstart == MAP_FAILED) {
 444                 msg(MSG_CRITICAL, "Unable to mmap %s: %s\n",
 445                     path, strerror(errno));
 446                 exit(EXIT_FAILURE);
 447         }
 448         ptr = mmapstart;
 449         max = mmapstart + sbuf.st_size;
 450
 451         if (strncmp(ptr, SIGNATURE, SIGNATURELEN)) {
 452                 msg(MSG_CRITICAL, "Invalid signature for file %s\n", path);
 453                 goto out;
 454         }
 455         ptr += SIGNATURELEN;
 456
 457         if (strncmp(ptr, VERSION, VERSIONLEN)) {
 458                 msg(MSG_CRITICAL, "Invalid version of file %s\n", path);
 459                 goto out;
 460         }
 461         ptr += VERSIONLEN;
 462
 463         while (ptr < mmapstart + sbuf.st_size) {
 464                 if (*ptr == '\0') {
 465                         msg(MSG_CRITICAL, "Invalid characters in file %s\n",
 466                             path);
 467                         goto out;
 468                 }
 469
 470                 mentry = mentry_alloc();
 471                 mentry->path = read_string(&ptr, max);
 472                 mentry->owner = read_string(&ptr, max);
 473                 mentry->group = read_string(&ptr, max);
 474                 mentry->mtime = (time_t)read_int(&ptr, 8, max);
 475                 mentry->mtimensec = (time_t)read_int(&ptr, 8, max);
 476                 mentry->mode = (mode_t)read_int(&ptr, 2, max);
 477                 mentry->xattrs = (unsigned int)read_int(&ptr, 4, max);
 478
 479                 if (!mentry->xattrs) {
 480                         mentry_insert(mentry, *mhash);
 481                         continue;
 482                 }
 483
 484                 mentry->xattr_names = xmalloc(mentry->xattrs *
 485                                       sizeof(char *));
 486                 mentry->xattr_lvalues = xmalloc(mentry->xattrs *
 487                                         sizeof(int));
 488                 mentry->xattr_values = xmalloc(mentry->xattrs *
 489                                        sizeof(char *));
 490
 491                 for (i = 0; i < mentry->xattrs; i++) {
 492                         mentry->xattr_names[i] = read_string(&ptr, max);
 493                         mentry->xattr_lvalues[i] =
 494                                 (int)read_int(&ptr, 4, max);
 495                         mentry->xattr_values[i] =
 496                                 read_binary_string(&ptr,
 497                                                    mentry->xattr_lvalues[i],
 498                                                    max);
 499                 }
 500                 mentry_insert(mentry, *mhash);
 501         }
 502
 503 out:
 504         munmap(mmapstart, sbuf.st_size);
 505         close(fd);
 506 }
 507
 508 /* Searches haystack for an xattr matching xattr number n in needle */
 509 int
 510 mentry_find_xattr(struct metaentry *haystack, struct metaentry *needle, int n)
 511 {
 512         int i;
 513
 514         for (i = 0; i < haystack->xattrs; i++) {
 515                 if (strcmp(haystack->xattr_names[i], needle->xattr_names[n]))
 516                         continue;
 517                 if (haystack->xattr_lvalues[i] != needle->xattr_lvalues[n])
 518                         return -1;
 519                 if (bcmp(haystack->xattr_values[i], needle->xattr_values[n],
 520                          needle->xattr_lvalues[n]))
 521                         return -1;
 522                 return i;
 523         }
 524         return -1;
 525 }
 526
 527 /* Returns zero if all xattrs in left and right match */
 528 static int
 529 mentry_compare_xattr(struct metaentry *left, struct metaentry *right)
 530 {
 531         int i;
 532
 533         if (left->xattrs != right->xattrs)
 534                 return 1;
 535
 536         /* Make sure all xattrs in left are found in right and vice versa */
 537         for (i = 0; i < left->xattrs; i++) {
 538                 if (mentry_find_xattr(right, left, i) < 0 ||
 539                     mentry_find_xattr(left, right, i) < 0) {
 540                         return 1;
 541                 }
 542         }
 543
 544         return 0;
 545 }
 546
 547 /* Compares two metaentries and returns an int with a bitmask of differences */
 548 static int
 549 mentry_compare(struct metaentry *left, struct metaentry *right, int do_mtime)
 550 {
 551         int retval = DIFF_NONE;
 552
 553         if (!left || !right) {
 554                 msg(MSG_ERROR, "%s called with empty list\n", __FUNCTION__);
 555                 return -1;
 556         }
 557
 558         if (strcmp(left->path, right->path))
 559                 return -1;
 560
 561         if (strcmp(left->owner, right->owner))
 562                 retval |= DIFF_OWNER;
 563
 564         if (strcmp(left->group, right->group))
 565                 retval |= DIFF_GROUP;
 566
 567         if ((left->mode & 07777) != (right->mode & 07777))
 568                 retval |= DIFF_MODE;
 569
 570         if ((left->mode & S_IFMT) != (right->mode & S_IFMT))
 571                 retval |= DIFF_TYPE;
 572
 573         if (do_mtime && strcmp(left->path, METAFILE) &&
 574             (left->mtime != right->mtime ||
 575              left->mtimensec != right->mtimensec))
 576                 retval |= DIFF_MTIME;
 577
 578         if (mentry_compare_xattr(left, right)) {
 579                 retval |= DIFF_XATTR;
 580                 return retval;
 581         }
 582
 583         return retval;
 584 }
 585
 586 /* Compares lists of real and stored metadata and calls pfunc for each */
 587 void
 588 mentries_compare(struct metahash *mhashreal,
 589                  struct metahash *mhashstored,
 590                  void (*pfunc)
 591                  (struct metaentry *real, struct metaentry *stored, int do_mtime),
 592                  int do_mtime)
 593 {
 594         struct metaentry *real, *stored;
 595         int key;
 596
 597         if (!mhashreal || !mhashstored) {
 598                 msg(MSG_ERROR, "%s called with empty list\n", __FUNCTION__);
 599                 return;
 600         }
 601
 602         for (key = 0; key < HASH_INDEXES; key++) {
 603                 for (real = mhashreal->bucket[key]; real; real = real->next) {
 604                         stored = mentry_find(real->path, mhashstored);
 605
 606                         if (!stored)
 607                                 pfunc(real, NULL, DIFF_ADDED);
 608                         else
 609                                 pfunc(real, stored, mentry_compare(real, stored, do_mtime));
 610                 }
 611
 612                 for (stored = mhashstored->bucket[key]; stored; stored = stored->next) {
 613                         real = mentry_find(stored->path, mhashreal);
 614
 615                         if (!real)
 616                                 pfunc(NULL, stored, DIFF_DELE);
 617                 }
 618         }
 619 }
 620