src/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; only version 2 of the License is applicable.
   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 #include <bsd/string.h>
  36 #include <time.h>
  37
  38 #include "metastore.h"
  39 #include "metaentry.h"
  40 #include "utils.h"
  41
  42 /* Free's a metaentry and all its parameters */
  43 static void
  44 mentry_free(struct metaentry *m)
  45 {
  46         unsigned i;
  47
  48         if (!m)
  49                 return;
  50
  51         free(m->path);
  52         free(m->owner);
  53         free(m->group);
  54
  55         for (i = 0; i < m->xattrs; i++) {
  56                 free(m->xattr_names[i]);
  57                 free(m->xattr_values[i]);
  58         }
  59
  60         free(m->xattr_names);
  61         free(m->xattr_values);
  62         free(m->xattr_lvalues);
  63
  64         free(m);
  65 }
  66
  67 /* Allocates an empty metahash table */
  68 static struct metahash *
  69 mhash_alloc()
  70 {
  71         struct metahash *mhash;
  72         mhash = xmalloc(sizeof(struct metahash));
  73         memset(mhash, 0, sizeof(struct metahash));
  74         return mhash;
  75 }
  76
  77 /* Generates a hash key (using djb2) */
  78 static unsigned int
  79 hash(const char *str)
  80 {
  81         unsigned int hash = 5381;
  82         int c;
  83
  84         while ((c = *str++))
  85                 hash = ((hash << 5) + hash) + c;
  86
  87         return hash % HASH_INDEXES;
  88 }
  89
  90 /* Allocates an empty metaentry */
  91 static struct metaentry *
  92 mentry_alloc()
  93 {
  94         struct metaentry *mentry;
  95         mentry = xmalloc(sizeof(struct metaentry));
  96         memset(mentry, 0, sizeof(struct metaentry));
  97         return mentry;
  98 }
  99
 100 /* Does a bisect search for the closest match in a metaentry list */
 101 struct metaentry *
 102 mentry_find(const char *path, struct metahash *mhash)
 103 {
 104         struct metaentry *base;
 105         unsigned int key;
 106
 107         if (!mhash) {
 108                 msg(MSG_ERROR, "%s called with empty hash table\n", __FUNCTION__);
 109                 return NULL;
 110         }
 111
 112         key = hash(path);
 113         for (base = mhash->bucket[key]; base; base = base->next) {
 114                 if (!strcmp(base->path, path))
 115                         return base;
 116         }
 117
 118         return NULL;
 119 }
 120
 121 /* Inserts a metaentry into a metaentry list */
 122 static void
 123 mentry_insert(struct metaentry *mentry, struct metahash *mhash)
 124 {
 125         unsigned int key;
 126
 127         key = hash(mentry->path);
 128         mentry->next = mhash->bucket[key];
 129         mhash->bucket[key] = mentry;
 130 }
 131
 132 #ifdef DEBUG
 133 /* Prints a metaentry */
 134 static void
 135 mentry_print(const struct metaentry *mentry)
 136 {
 137         int i;
 138
 139         if (!mentry || !mentry->path) {
 140                 msg(MSG_DEBUG,
 141                     "Incorrect meta entry passed to printmetaentry\n");
 142                 return;
 143         }
 144
 145         msg(MSG_DEBUG, "===========================\n");
 146         msg(MSG_DEBUG, "Dump of metaentry %p\n", mentry);
 147         msg(MSG_DEBUG, "===========================\n");
 148
 149         msg(MSG_DEBUG, "path\t\t: %s\n", mentry->path);
 150         msg(MSG_DEBUG, "owner\t\t: %s\n", mentry->owner);
 151         msg(MSG_DEBUG, "group\t\t: %s\n", mentry->group);
 152         msg(MSG_DEBUG, "mtime\t\t: %ld\n", (unsigned long)mentry->mtime);
 153         msg(MSG_DEBUG, "mtimensec\t: %ld\n", (unsigned long)mentry->mtimensec);
 154         msg(MSG_DEBUG, "mode\t\t: %ld\n", (unsigned long)mentry->mode);
 155         for (i = 0; i < mentry->xattrs; i++) {
 156                 msg(MSG_DEBUG, "xattr[%i]\t: %s=\"", i, mentry->xattr_names[i]);
 157                 binary_print(mentry->xattr_values[i], mentry->xattr_lvalues[i]);
 158                 msg(MSG_DEBUG, "\"\n");
 159         }
 160
 161         msg(MSG_DEBUG, "===========================\n\n");
 162 }
 163
 164 /* Prints all metaentries in a metaentry list */
 165 static void
 166 mentries_print(const struct metahash *mhash)
 167 {
 168         const struct metaentry *mentry;
 169         int index;
 170
 171         for (index = 0; index < HASH_INDEXES; index++)
 172                 for (mentry = mhash->bucket[index]; mentry; mentry = mentry->next)
 173                         mentry_print(mentry);
 174
 175         msg(MSG_DEBUG, "%i entries in total\n", mhash->count);
 176 }
 177 #endif
 178
 179 /* Creates a metaentry for the file/dir/etc at path */
 180 struct metaentry *
 181 mentry_create(const char *path)
 182 {
 183         ssize_t lsize, vsize;
 184         char *list, *attr;
 185         struct stat sbuf;
 186         struct passwd *pbuf;
 187         struct group *gbuf;
 188         int i;
 189         struct metaentry *mentry;
 190
 191         if (lstat(path, &sbuf)) {
 192                 msg(MSG_ERROR, "lstat failed for %s: %s\n",
 193                     path, strerror(errno));
 194                 return NULL;
 195         }
 196
 197         pbuf = xgetpwuid(sbuf.st_uid);
 198         if (!pbuf) {
 199                 msg(MSG_ERROR, "getpwuid failed for %s: uid %i not found\n",
 200                     path, (int)sbuf.st_uid);
 201                 return NULL;
 202         }
 203
 204         gbuf = xgetgrgid(sbuf.st_gid);
 205         if (!gbuf) {
 206                 msg(MSG_ERROR, "getgrgid failed for %s: gid %i not found\n",
 207                     path, (int)sbuf.st_gid);
 208                 return NULL;
 209         }
 210
 211         mentry = mentry_alloc();
 212         mentry->path = xstrdup(path);
 213         mentry->pathlen = strlen(mentry->path);
 214         mentry->owner = xstrdup(pbuf->pw_name);
 215         mentry->group = xstrdup(gbuf->gr_name);
 216         mentry->mode = sbuf.st_mode & 0177777;
 217         mentry->mtime = sbuf.st_mtim.tv_sec;
 218         mentry->mtimensec = sbuf.st_mtim.tv_nsec;
 219
 220         /* symlinks have no xattrs */
 221         if (S_ISLNK(mentry->mode))
 222                 return mentry;
 223
 224         lsize = listxattr(path, NULL, 0);
 225         if (lsize < 0) {
 226                 /* Perhaps the FS doesn't support xattrs? */
 227                 if (errno == ENOTSUP)
 228                         return mentry;
 229
 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 = realpath(orig, NULL);
 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, msettings *st)
 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                             (!st->do_git && !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, st);
 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, msettings *st)
 367 {
 368         char *path = normalize_path(opath);
 369
 370         if (!(*mhash))
 371                 *mhash = mhash_alloc();
 372         mentries_recurse(path, *mhash, st);
 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;
 383         unsigned i;
 384
 385         to = fopen(path, "w");
 386         if (!to) {
 387                 msg(MSG_CRITICAL, "Failed to open %s: %s\n",
 388                     path, strerror(errno));
 389                 exit(EXIT_FAILURE);
 390         }
 391
 392         write_binary_string(SIGNATURE, SIGNATURELEN, to);
 393         write_binary_string(VERSION, VERSIONLEN, to);
 394
 395         for (key = 0; key < HASH_INDEXES; key++) {
 396                 for (mentry = mhash->bucket[key]; mentry; mentry = mentry->next) {
 397                         write_string(mentry->path, to);
 398                         write_string(mentry->owner, to);
 399                         write_string(mentry->group, to);
 400                         write_int((uint64_t)mentry->mtime, 8, to);
 401                         write_int((uint64_t)mentry->mtimensec, 8, to);
 402                         write_int((uint64_t)mentry->mode, 2, to);
 403                         write_int(mentry->xattrs, 4, to);
 404                         for (i = 0; i < mentry->xattrs; i++) {
 405                                 write_string(mentry->xattr_names[i], to);
 406                                 write_int(mentry->xattr_lvalues[i], 4, to);
 407                                 write_binary_string(mentry->xattr_values[i],
 408                                                     mentry->xattr_lvalues[i], to);
 409                         }
 410                 }
 411         }
 412
 413         fclose(to);
 414 }
 415
 416 /* Creates a metaentry list from a file */
 417 void
 418 mentries_fromfile(struct metahash **mhash, const char *path)
 419 {
 420         struct metaentry *mentry;
 421         char *mmapstart;
 422         char *ptr;
 423         char *max;
 424         int fd;
 425         struct stat sbuf;
 426         unsigned i;
 427
 428         if (!(*mhash))
 429                 *mhash = mhash_alloc();
 430
 431         fd = open(path, O_RDONLY);
 432         if (fd < 0) {
 433                 msg(MSG_CRITICAL, "Failed to open %s: %s\n",
 434                     path, strerror(errno));
 435                 exit(EXIT_FAILURE);
 436         }
 437
 438         if (fstat(fd, &sbuf)) {
 439                 msg(MSG_CRITICAL, "Failed to stat %s: %s\n",
 440                     path, strerror(errno));
 441                 exit(EXIT_FAILURE);
 442         }
 443
 444         if (sbuf.st_size < (SIGNATURELEN + VERSIONLEN)) {
 445                 msg(MSG_CRITICAL, "File %s has an invalid size\n", path);
 446                 exit(EXIT_FAILURE);
 447         }
 448
 449         mmapstart = mmap(NULL, (size_t)sbuf.st_size, PROT_READ,
 450                          MAP_SHARED, fd, 0);
 451         if (mmapstart == MAP_FAILED) {
 452                 msg(MSG_CRITICAL, "Unable to mmap %s: %s\n",
 453                     path, strerror(errno));
 454                 exit(EXIT_FAILURE);
 455         }
 456         ptr = mmapstart;
 457         max = mmapstart + sbuf.st_size;
 458
 459         if (strncmp(ptr, SIGNATURE, SIGNATURELEN)) {
 460                 msg(MSG_CRITICAL, "Invalid signature for file %s\n", path);
 461                 goto out;
 462         }
 463         ptr += SIGNATURELEN;
 464
 465         if (strncmp(ptr, VERSION, VERSIONLEN)) {
 466                 msg(MSG_CRITICAL, "Invalid version of file %s\n", path);
 467                 goto out;
 468         }
 469         ptr += VERSIONLEN;
 470
 471         while (ptr < mmapstart + sbuf.st_size) {
 472                 if (*ptr == '\0') {
 473                         msg(MSG_CRITICAL, "Invalid characters in file %s\n",
 474                             path);
 475                         goto out;
 476                 }
 477
 478                 mentry = mentry_alloc();
 479                 mentry->path = read_string(&ptr, max);
 480                 mentry->pathlen = strlen(mentry->path);
 481                 mentry->owner = read_string(&ptr, max);
 482                 mentry->group = read_string(&ptr, max);
 483                 mentry->mtime = (time_t)read_int(&ptr, 8, max);
 484                 mentry->mtimensec = (time_t)read_int(&ptr, 8, max);
 485                 mentry->mode = (mode_t)read_int(&ptr, 2, max);
 486                 mentry->xattrs = (unsigned int)read_int(&ptr, 4, max);
 487
 488                 if (!mentry->xattrs) {
 489                         mentry_insert(mentry, *mhash);
 490                         continue;
 491                 }
 492
 493                 mentry->xattr_names = xmalloc(mentry->xattrs *
 494                                       sizeof(char *));
 495                 mentry->xattr_lvalues = xmalloc(mentry->xattrs *
 496                                         sizeof(int));
 497                 mentry->xattr_values = xmalloc(mentry->xattrs *
 498                                        sizeof(char *));
 499
 500                 for (i = 0; i < mentry->xattrs; i++) {
 501                         mentry->xattr_names[i] = read_string(&ptr, max);
 502                         mentry->xattr_lvalues[i] =
 503                                 (int)read_int(&ptr, 4, max);
 504                         mentry->xattr_values[i] =
 505                                 read_binary_string(&ptr,
 506                                                    mentry->xattr_lvalues[i],
 507                                                    max);
 508                 }
 509                 mentry_insert(mentry, *mhash);
 510         }
 511
 512 out:
 513         munmap(mmapstart, sbuf.st_size);
 514         close(fd);
 515 }
 516
 517 /* Searches haystack for an xattr matching xattr number n in needle */
 518 int
 519 mentry_find_xattr(struct metaentry *haystack, struct metaentry *needle,
 520                   unsigned n)
 521 {
 522         unsigned i;
 523
 524         for (i = 0; i < haystack->xattrs; i++) {
 525                 if (strcmp(haystack->xattr_names[i], needle->xattr_names[n]))
 526                         continue;
 527                 if (haystack->xattr_lvalues[i] != needle->xattr_lvalues[n])
 528                         return -1;
 529                 if (bcmp(haystack->xattr_values[i], needle->xattr_values[n],
 530                          needle->xattr_lvalues[n]))
 531                         return -1;
 532                 return i;
 533         }
 534         return -1;
 535 }
 536
 537 /* Returns zero if all xattrs in left and right match */
 538 static int
 539 mentry_compare_xattr(struct metaentry *left, struct metaentry *right)
 540 {
 541         unsigned i;
 542
 543         if (left->xattrs != right->xattrs)
 544                 return 1;
 545
 546         /* Make sure all xattrs in left are found in right and vice versa */
 547         for (i = 0; i < left->xattrs; i++) {
 548                 if (mentry_find_xattr(right, left, i) < 0 ||
 549                     mentry_find_xattr(left, right, i) < 0) {
 550                         return 1;
 551                 }
 552         }
 553
 554         return 0;
 555 }
 556
 557 /* Compares two metaentries and returns an int with a bitmask of differences */
 558 int
 559 mentry_compare(struct metaentry *left, struct metaentry *right, msettings *st)
 560 {
 561         int retval = DIFF_NONE;
 562
 563         if (!left || !right) {
 564                 msg(MSG_ERROR, "%s called with empty list\n", __FUNCTION__);
 565                 return -1;
 566         }
 567
 568         if (strcmp(left->path, right->path))
 569                 return -1;
 570
 571         if (strcmp(left->owner, right->owner))
 572                 retval |= DIFF_OWNER;
 573
 574         if (strcmp(left->group, right->group))
 575                 retval |= DIFF_GROUP;
 576
 577         if ((left->mode & 07777) != (right->mode & 07777))
 578                 retval |= DIFF_MODE;
 579
 580         if ((left->mode & S_IFMT) != (right->mode & S_IFMT))
 581                 retval |= DIFF_TYPE;
 582
 583         if (st->do_mtime && strcmp(left->path, st->metafile) &&
 584             (left->mtime != right->mtime ||
 585              left->mtimensec != right->mtimensec))
 586                 retval |= DIFF_MTIME;
 587
 588         if (mentry_compare_xattr(left, right)) {
 589                 retval |= DIFF_XATTR;
 590                 return retval;
 591         }
 592
 593         return retval;
 594 }
 595
 596 /* Compares lists of real and stored metadata and calls pfunc for each */
 597 void
 598 mentries_compare(struct metahash *mhashreal,
 599                  struct metahash *mhashstored,
 600                  void (*pfunc)
 601                  (struct metaentry *real, struct metaentry *stored, int cmp),
 602                  msettings *st)
 603 {
 604         struct metaentry *real, *stored;
 605         int key;
 606
 607         if (!mhashreal || !mhashstored) {
 608                 msg(MSG_ERROR, "%s called with empty list\n", __FUNCTION__);
 609                 return;
 610         }
 611
 612         for (key = 0; key < HASH_INDEXES; key++) {
 613                 for (real = mhashreal->bucket[key]; real; real = real->next) {
 614                         stored = mentry_find(real->path, mhashstored);
 615
 616                         if (!stored)
 617                                 pfunc(real, NULL, DIFF_ADDED);
 618                         else
 619                                 pfunc(real, stored, mentry_compare(real, stored, st));
 620                 }
 621
 622                 for (stored = mhashstored->bucket[key]; stored; stored = stored->next) {
 623                         real = mentry_find(stored->path, mhashreal);
 624
 625                         if (!real)
 626                                 pfunc(NULL, stored, DIFF_DELE);
 627                 }
 628         }
 629 }
 630
 631 /* Dumps given metadata */
 632 void
 633 mentries_dump(struct metahash *mhash)
 634 {
 635         const struct metaentry *mentry;
 636         char mode[11 + 1] = "";
 637         char date[12 + 2 + 2 + 2*1 + 1 + 2 + 2 + 2 + 2*1 + 1] = "";
 638         char zone[5 + 1] = "";
 639         struct tm cal;
 640
 641         for (int key = 0; key < HASH_INDEXES; key++) {
 642                 for (mentry = mhash->bucket[key]; mentry; mentry = mentry->next) {
 643                         strmode(mentry->mode, mode);
 644                         localtime_r(&mentry->mtime, &cal);
 645                         strftime(date, sizeof(date), "%F %T", &cal);
 646                         strftime(zone, sizeof(zone), "%z", &cal);
 647                         printf("%s\t%s\t%s\t%s.%09ld %s\t%s%s\n",
 648                                mode,
 649                                mentry->owner, mentry->group,
 650                                date, mentry->mtimensec, zone,
 651                                mentry->path, S_ISDIR(mentry->mode) ? "/" : "");
 652                         for (int i = 0; i < mentry->xattrs; i++) {
 653                                 printf("\t\t\t\t%s%s\t%s=",
 654                                        mentry->path, S_ISDIR(mentry->mode) ? "/" : "",
 655                                        mentry->xattr_names[i]);
 656                                 ssize_t p = 0;
 657                                 for (; p < mentry->xattr_lvalues[i]; p++) {
 658                                         const char ch = mentry->xattr_values[i][p];
 659                                         if ((unsigned)(ch - 32) > 126 - 32) {
 660                                                 p = -1;
 661                                                 break;
 662                                         }
 663                                 }
 664                                 if (p >= 0)
 665                                         printf("\"%.*s\"\n",
 666                                                (int)mentry->xattr_lvalues[i],
 667                                                mentry->xattr_values[i]);
 668                                 else {
 669                                         printf("0x");
 670                                         for (p = 0; p < mentry->xattr_lvalues[i]; p++)
 671                                                 printf("%02hhx", (char)mentry->xattr_values[i][p]);
 672                                         printf("\n");
 673                                 }
 674                         }
 675                 }
 676         }
 677 }