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         struct metaentry *base;
 124         unsigned int key;
 125
 126         key = hash(mentry->path);
 127         if (!mhash->bucket[key]) {
 128                 mhash->bucket[key] = mentry;
 129                 return;
 130         }
 131
 132         for (base = mhash->bucket[key]; base->next; base = base->next)
 133                 /* Do nothing */;
 134         base->next = mentry;
 135 }
 136
 137 #ifdef DEBUG
 138 /* Prints a metaentry */
 139 static void
 140 mentry_print(const struct metaentry *mentry)
 141 {
 142         int i;
 143
 144         if (!mentry || !mentry->path) {
 145                 msg(MSG_DEBUG,
 146                     "Incorrect meta entry passed to printmetaentry\n");
 147                 return;
 148         }
 149
 150         msg(MSG_DEBUG, "===========================\n");
 151         msg(MSG_DEBUG, "Dump of metaentry %p\n", mentry);
 152         msg(MSG_DEBUG, "===========================\n");
 153
 154         msg(MSG_DEBUG, "path\t\t: %s\n", mentry->path);
 155         msg(MSG_DEBUG, "owner\t\t: %s\n", mentry->owner);
 156         msg(MSG_DEBUG, "group\t\t: %s\n", mentry->group);
 157         msg(MSG_DEBUG, "mtime\t\t: %ld\n", (unsigned long)mentry->mtime);
 158         msg(MSG_DEBUG, "mtimensec\t: %ld\n", (unsigned long)mentry->mtimensec);
 159         msg(MSG_DEBUG, "mode\t\t: %ld\n", (unsigned long)mentry->mode);
 160         for (i = 0; i < mentry->xattrs; i++) {
 161                 msg(MSG_DEBUG, "xattr[%i]\t: %s=\"", i, mentry->xattr_names[i]);
 162                 binary_print(mentry->xattr_values[i], mentry->xattr_lvalues[i]);
 163                 msg(MSG_DEBUG, "\"\n");
 164         }
 165
 166         msg(MSG_DEBUG, "===========================\n\n");
 167 }
 168
 169 /* Prints all metaentries in a metaentry list */
 170 static void
 171 mentries_print(const struct metahash *mhash)
 172 {
 173         const struct metaentry *mentry;
 174         int index;
 175
 176         for (index = 0; index < HASH_INDEXES; index++)
 177                 for (mentry = mhash->bucket[i]; mentry; mentry = mentry->next)
 178                         mentry_print(mentry);
 179
 180         msg(MSG_DEBUG, "%i entries in total\n", mhash->count);
 181 }
 182 #endif
 183
 184 /* Creates a metaentry for the file/dir/etc at path */
 185 static struct metaentry *
 186 mentry_create(const char *path)
 187 {
 188         ssize_t lsize, vsize;
 189         char *list, *attr;
 190         struct stat sbuf;
 191         struct passwd *pbuf;
 192         struct group *gbuf;
 193         int i;
 194         struct metaentry *mentry;
 195
 196         if (lstat(path, &sbuf)) {
 197                 msg(MSG_ERROR, "lstat failed for %s: %s\n",
 198                     path, strerror(errno));
 199                 return NULL;
 200         }
 201
 202         pbuf = xgetpwuid(sbuf.st_uid);
 203         if (!pbuf) {
 204                 msg(MSG_ERROR, "getpwuid failed for %i: %s\n",
 205                     (int)sbuf.st_uid, strerror(errno));
 206                 return NULL;
 207         }
 208
 209         gbuf = xgetgrgid(sbuf.st_gid);
 210         if (!gbuf) {
 211                 msg(MSG_ERROR, "getgrgid failed for %i: %s\n",
 212                     (int)sbuf.st_gid, strerror(errno));
 213                 return NULL;
 214         }
 215
 216         mentry = mentry_alloc();
 217         mentry->path = xstrdup(path);
 218         mentry->owner = xstrdup(pbuf->pw_name);
 219         mentry->group = xstrdup(gbuf->gr_name);
 220         mentry->mode = sbuf.st_mode & 0177777;
 221         mentry->mtime = sbuf.st_mtim.tv_sec;
 222         mentry->mtimensec = sbuf.st_mtim.tv_nsec;
 223
 224         /* symlinks have no xattrs */
 225         if (S_ISLNK(mentry->mode))
 226                 return mentry;
 227
 228         lsize = listxattr(path, NULL, 0);
 229         if (lsize < 0) {
 230                 msg(MSG_ERROR, "listxattr failed for %s: %s\n",
 231                     path, strerror(errno));
 232                 return NULL;
 233         }
 234
 235         list = xmalloc(lsize);
 236         lsize = listxattr(path, list, lsize);
 237         if (lsize < 0) {
 238                 msg(MSG_ERROR, "listxattr failed for %s: %s\n",
 239                     path, strerror(errno));
 240                 free(list);
 241                 return NULL;
 242         }
 243
 244         i = 0;
 245         for (attr = list; attr < list + lsize; attr = strchr(attr, '\0') + 1) {
 246                 if (*attr == '\0')
 247                         continue;
 248                 i++;
 249         }
 250
 251         if (i == 0)
 252                 return mentry;
 253
 254         mentry->xattrs = i;
 255         mentry->xattr_names = xmalloc(i * sizeof(char *));
 256         mentry->xattr_values = xmalloc(i * sizeof(char *));
 257         mentry->xattr_lvalues = xmalloc(i * sizeof(ssize_t));
 258
 259         i = 0;
 260         for (attr = list; attr < list + lsize; attr = strchr(attr, '\0') + 1) {
 261                 if (*attr == '\0')
 262                         continue;
 263
 264                 mentry->xattr_names[i] = xstrdup(attr);
 265                 vsize = getxattr(path, attr, NULL, 0);
 266                 if (vsize < 0) {
 267                         msg(MSG_ERROR, "getxattr failed for %s: %s\n",
 268                             path, strerror(errno));
 269                         free(list);
 270                         mentry_free(mentry);
 271                         return NULL;
 272                 }
 273
 274                 mentry->xattr_lvalues[i] = vsize;
 275                 mentry->xattr_values[i] = xmalloc(vsize);
 276
 277                 vsize = getxattr(path, attr, mentry->xattr_values[i], vsize);
 278                 if (vsize < 0) {
 279                         msg(MSG_ERROR, "getxattr failed for %s: %s\n",
 280                             path, strerror(errno));
 281                         free(list);
 282                         mentry_free(mentry);
 283                         return NULL;
 284                 }
 285                 i++;
 286         }
 287
 288         free(list);
 289         return mentry;
 290 }
 291
 292 /* Cleans up a path and makes it relative to current working dir unless it is absolute */
 293 static char *
 294 normalize_path(const char *orig)
 295 {
 296         char *real = canonicalize_file_name(orig);
 297         char cwd[PATH_MAX];
 298         char *result;
 299
 300         getcwd(cwd, PATH_MAX);
 301         if (!real)
 302                 return NULL;
 303
 304         if (!strncmp(real, cwd, strlen(cwd))) {
 305                 result = xmalloc(strlen(real) - strlen(cwd) + 1 + 1);
 306                 result[0] = '\0';
 307                 strcat(result, ".");
 308                 strcat(result, real + strlen(cwd));
 309         } else {
 310                 result = xstrdup(real);
 311         }
 312
 313         free(real);
 314         return result;
 315 }
 316
 317 /* Internal function for the recursive path walk */
 318 static void
 319 mentries_recurse(const char *path, struct metahash *mhash)
 320 {
 321         struct stat sbuf;
 322         struct metaentry *mentry;
 323         char tpath[PATH_MAX];
 324         DIR *dir;
 325         struct dirent *dent;
 326
 327         if (!path)
 328                 return;
 329
 330         if (lstat(path, &sbuf)) {
 331                 msg(MSG_ERROR, "lstat failed for %s: %s\n",
 332                     path, strerror(errno));
 333                 return;
 334         }
 335
 336         mentry = mentry_create(path);
 337         if (!mentry)
 338                 return;
 339
 340         mentry_insert(mentry, mhash);
 341
 342         if (S_ISDIR(sbuf.st_mode)) {
 343                 dir = opendir(path);
 344                 if (!dir) {
 345                         msg(MSG_ERROR, "opendir failed for %s: %s\n",
 346                             path, strerror(errno));
 347                         return;
 348                 }
 349
 350                 while ((dent = readdir(dir))) {
 351                         if (!strcmp(dent->d_name, ".") ||
 352                             !strcmp(dent->d_name, "..") ||
 353                             !strcmp(dent->d_name, ".git"))
 354                                 continue;
 355                         snprintf(tpath, PATH_MAX, "%s/%s", path, dent->d_name);
 356                         tpath[PATH_MAX - 1] = '\0';
 357                         mentries_recurse(tpath, mhash);
 358                 }
 359
 360                 closedir(dir);
 361         }
 362 }
 363
 364 /* Recurses opath and adds metadata entries to the metaentry list */
 365 void
 366 mentries_recurse_path(const char *opath, struct metahash **mhash)
 367 {
 368         char *path = normalize_path(opath);
 369
 370         if (!(*mhash))
 371                 *mhash = mhash_alloc();
 372         mentries_recurse(path, *mhash);
 373         free(path);
 374 }
 375
 376 /* Stores metaentries to a file */
 377 void
 378 mentries_tofile(const struct metahash *mhash, const char *path)
 379 {
 380         FILE *to;
 381         const struct metaentry *mentry;
 382         int key, i;
 383
 384         to = fopen(path, "w");
 385         if (!to) {
 386                 msg(MSG_CRITICAL, "Failed to open %s: %s\n",
 387                     path, strerror(errno));
 388                 exit(EXIT_FAILURE);
 389         }
 390
 391         write_binary_string(SIGNATURE, SIGNATURELEN, to);
 392         write_binary_string(VERSION, VERSIONLEN, to);
 393
 394         for (key = 0; key < HASH_INDEXES; key++) {
 395                 for (mentry = mhash->bucket[key]; mentry; mentry = mentry->next) {
 396                         write_string(mentry->path, to);
 397                         write_string(mentry->owner, to);
 398                         write_string(mentry->group, to);
 399                         write_int((uint64_t)mentry->mtime, 8, to);
 400                         write_int((uint64_t)mentry->mtimensec, 8, to);
 401                         write_int((uint64_t)mentry->mode, 2, to);
 402                         write_int(mentry->xattrs, 4, to);
 403                         for (i = 0; i < mentry->xattrs; i++) {
 404                                 write_string(mentry->xattr_names[i], to);
 405                                 write_int(mentry->xattr_lvalues[i], 4, to);
 406                                 write_binary_string(mentry->xattr_values[i],
 407                                                     mentry->xattr_lvalues[i], to);
 408                         }
 409                 }
 410         }
 411
 412         fclose(to);
 413 }
 414
 415 /* Creates a metaentry list from a file */
 416 void
 417 mentries_fromfile(struct metahash **mhash, const char *path)
 418 {
 419         struct metaentry *mentry;
 420         char *mmapstart;
 421         char *ptr;
 422         char *max;
 423         int fd;
 424         struct stat sbuf;
 425         int i;
 426
 427         if (!(*mhash))
 428                 *mhash = mhash_alloc();
 429
 430         fd = open(path, O_RDONLY);
 431         if (fd < 0) {
 432                 msg(MSG_CRITICAL, "Failed to open %s: %s\n",
 433                     path, strerror(errno));
 434                 exit(EXIT_FAILURE);
 435         }
 436
 437         if (fstat(fd, &sbuf)) {
 438                 msg(MSG_CRITICAL, "Failed to stat %s: %s\n",
 439                     path, strerror(errno));
 440                 exit(EXIT_FAILURE);
 441         }
 442
 443         if (sbuf.st_size < (SIGNATURELEN + VERSIONLEN)) {
 444                 msg(MSG_CRITICAL, "File %s has an invalid size\n", path);
 445                 exit(EXIT_FAILURE);
 446         }
 447
 448         mmapstart = mmap(NULL, (size_t)sbuf.st_size, PROT_READ,
 449                          MAP_SHARED, fd, 0);
 450         if (mmapstart == MAP_FAILED) {
 451                 msg(MSG_CRITICAL, "Unable to mmap %s: %s\n",
 452                     path, strerror(errno));
 453                 exit(EXIT_FAILURE);
 454         }
 455         ptr = mmapstart;
 456         max = mmapstart + sbuf.st_size;
 457
 458         if (strncmp(ptr, SIGNATURE, SIGNATURELEN)) {
 459                 msg(MSG_CRITICAL, "Invalid signature for file %s\n", path);
 460                 goto out;
 461         }
 462         ptr += SIGNATURELEN;
 463
 464         if (strncmp(ptr, VERSION, VERSIONLEN)) {
 465                 msg(MSG_CRITICAL, "Invalid version of file %s\n", path);
 466                 goto out;
 467         }
 468         ptr += VERSIONLEN;
 469
 470         while (ptr < mmapstart + sbuf.st_size) {
 471                 if (*ptr == '\0') {
 472                         msg(MSG_CRITICAL, "Invalid characters in file %s\n",
 473                             path);
 474                         goto out;
 475                 }
 476
 477                 mentry = mentry_alloc();
 478                 mentry->path = read_string(&ptr, max);
 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, int n)
 518 {
 519         int i;
 520
 521         for (i = 0; i < haystack->xattrs; i++) {
 522                 if (strcmp(haystack->xattr_names[i], needle->xattr_names[n]))
 523                         continue;
 524                 if (haystack->xattr_lvalues[i] != needle->xattr_lvalues[n])
 525                         return -1;
 526                 if (bcmp(haystack->xattr_values[i], needle->xattr_values[n],
 527                          needle->xattr_lvalues[n]))
 528                         return -1;
 529                 return i;
 530         }
 531         return -1;
 532 }
 533
 534 /* Returns zero if all xattrs in left and right match */
 535 static int
 536 mentry_compare_xattr(struct metaentry *left, struct metaentry *right)
 537 {
 538         int i;
 539
 540         if (left->xattrs != right->xattrs)
 541                 return 1;
 542
 543         /* Make sure all xattrs in left are found in right and vice versa */
 544         for (i = 0; i < left->xattrs; i++) {
 545                 if (mentry_find_xattr(right, left, i) < 0 ||
 546                     mentry_find_xattr(left, right, i) < 0) {
 547                         return 1;
 548                 }
 549         }
 550
 551         return 0;
 552 }
 553
 554 /* Compares two metaentries and returns an int with a bitmask of differences */
 555 static int
 556 mentry_compare(struct metaentry *left, struct metaentry *right, int do_mtime)
 557 {
 558         int retval = DIFF_NONE;
 559
 560         if (!left || !right) {
 561                 msg(MSG_ERROR, "%s called with empty list\n", __FUNCTION__);
 562                 return -1;
 563         }
 564
 565         if (strcmp(left->path, right->path))
 566                 return -1;
 567
 568         if (strcmp(left->owner, right->owner))
 569                 retval |= DIFF_OWNER;
 570
 571         if (strcmp(left->group, right->group))
 572                 retval |= DIFF_GROUP;
 573
 574         if ((left->mode & 07777) != (right->mode & 07777))
 575                 retval |= DIFF_MODE;
 576
 577         if ((left->mode & S_IFMT) != (right->mode & S_IFMT))
 578                 retval |= DIFF_TYPE;
 579
 580         if (do_mtime && strcmp(left->path, METAFILE) &&
 581             (left->mtime != right->mtime ||
 582              left->mtimensec != right->mtimensec))
 583                 retval |= DIFF_MTIME;
 584
 585         if (mentry_compare_xattr(left, right)) {
 586                 retval |= DIFF_XATTR;
 587                 return retval;
 588         }
 589
 590         return retval;
 591 }
 592
 593 /* Compares lists of real and stored metadata and calls pfunc for each */
 594 void
 595 mentries_compare(struct metahash *mhashreal,
 596                  struct metahash *mhashstored,
 597                  void (*pfunc)
 598                  (struct metaentry *real, struct metaentry *stored, int do_mtime),
 599                  int do_mtime)
 600 {
 601         struct metaentry *real, *stored;
 602         int key;
 603
 604         if (!mhashreal || !mhashstored) {
 605                 msg(MSG_ERROR, "%s called with empty list\n", __FUNCTION__);
 606                 return;
 607         }
 608
 609         for (key = 0; key < HASH_INDEXES; key++) {
 610                 for (real = mhashreal->bucket[key]; real; real = real->next) {
 611                         stored = mentry_find(real->path, mhashstored);
 612
 613                         if (!stored)
 614                                 pfunc(real, NULL, DIFF_ADDED);
 615                         else
 616                                 pfunc(real, stored, mentry_compare(real, stored, do_mtime));
 617                 }
 618
 619                 for (stored = mhashstored->bucket[key]; stored; stored = stored->next) {
 620                         real = mentry_find(stored->path, mhashreal);
 621
 622                         if (!real)
 623                                 pfunc(NULL, stored, DIFF_DELE);
 624                 }
 625         }
 626 }
 627