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 <time.h>
  36
  37 #include <sys/param.h>
  38 #ifndef BSD
  39 # include <bsd/string.h>
  40 #endif
  41
  42 #include "metastore.h"
  43 #include "metaentry.h"
  44 #include "utils.h"
  45
  46 /* Free's a metaentry and all its parameters */
  47 static void
  48 mentry_free(struct metaentry *m)
  49 {
  50         unsigned i;
  51
  52         if (!m)
  53                 return;
  54
  55         free(m->path);
  56         free(m->owner);
  57         free(m->group);
  58
  59         for (i = 0; i < m->xattrs; i++) {
  60                 free(m->xattr_names[i]);
  61                 free(m->xattr_values[i]);
  62         }
  63
  64         free(m->xattr_names);
  65         free(m->xattr_values);
  66         free(m->xattr_lvalues);
  67
  68         free(m);
  69 }
  70
  71 /* Allocates an empty metahash table */
  72 static struct metahash *
  73 mhash_alloc()
  74 {
  75         struct metahash *mhash;
  76         mhash = xmalloc(sizeof(struct metahash));
  77         memset(mhash, 0, sizeof(struct metahash));
  78         return mhash;
  79 }
  80
  81 /* Generates a hash key (using djb2) */
  82 static unsigned int
  83 hash(const char *str)
  84 {
  85         unsigned int hash = 5381;
  86         int c;
  87
  88         while ((c = *str++))
  89                 hash = ((hash << 5) + hash) + c;
  90
  91         return hash % HASH_INDEXES;
  92 }
  93
  94 /* Allocates an empty metaentry */
  95 static struct metaentry *
  96 mentry_alloc()
  97 {
  98         struct metaentry *mentry;
  99         mentry = xmalloc(sizeof(struct metaentry));
 100         memset(mentry, 0, sizeof(struct metaentry));
 101         return mentry;
 102 }
 103
 104 /* Does a bisect search for the closest match in a metaentry list */
 105 struct metaentry *
 106 mentry_find(const char *path, struct metahash *mhash)
 107 {
 108         struct metaentry *base;
 109         unsigned int key;
 110
 111         if (!mhash) {
 112                 msg(MSG_ERROR, "%s called with empty hash table\n", __FUNCTION__);
 113                 return NULL;
 114         }
 115
 116         key = hash(path);
 117         for (base = mhash->bucket[key]; base; base = base->next) {
 118                 if (!strcmp(base->path, path))
 119                         return base;
 120         }
 121
 122         return NULL;
 123 }
 124
 125 /* Inserts a metaentry into a metaentry list */
 126 static void
 127 mentry_insert(struct metaentry *mentry, struct metahash *mhash)
 128 {
 129         unsigned int key;
 130
 131         key = hash(mentry->path);
 132         mentry->next = mhash->bucket[key];
 133         mhash->bucket[key] = mentry;
 134 }
 135
 136 #ifdef DEBUG
 137 /* Prints a metaentry */
 138 static void
 139 mentry_print(const struct metaentry *mentry)
 140 {
 141         int i;
 142
 143         if (!mentry || !mentry->path) {
 144                 msg(MSG_DEBUG,
 145                     "Incorrect meta entry passed to printmetaentry\n");
 146                 return;
 147         }
 148
 149         msg(MSG_DEBUG, "===========================\n");
 150         msg(MSG_DEBUG, "Dump of metaentry %p\n", mentry);
 151         msg(MSG_DEBUG, "===========================\n");
 152
 153         msg(MSG_DEBUG, "path\t\t: %s\n", mentry->path);
 154         msg(MSG_DEBUG, "owner\t\t: %s\n", mentry->owner);
 155         msg(MSG_DEBUG, "group\t\t: %s\n", mentry->group);
 156         msg(MSG_DEBUG, "mtime\t\t: %ld\n", (unsigned long)mentry->mtime);
 157         msg(MSG_DEBUG, "mtimensec\t: %ld\n", (unsigned long)mentry->mtimensec);
 158         msg(MSG_DEBUG, "mode\t\t: %ld\n", (unsigned long)mentry->mode);
 159         for (i = 0; i < mentry->xattrs; i++) {
 160                 msg(MSG_DEBUG, "xattr[%i]\t: %s=\"", i, mentry->xattr_names[i]);
 161                 binary_print(mentry->xattr_values[i], mentry->xattr_lvalues[i]);
 162                 msg(MSG_DEBUG, "\"\n");
 163         }
 164
 165         msg(MSG_DEBUG, "===========================\n\n");
 166 }
 167
 168 /* Prints all metaentries in a metaentry list */
 169 static void
 170 mentries_print(const struct metahash *mhash)
 171 {
 172         const struct metaentry *mentry;
 173         int index;
 174
 175         for (index = 0; index < HASH_INDEXES; index++)
 176                 for (mentry = mhash->bucket[index]; mentry; mentry = mentry->next)
 177                         mentry_print(mentry);
 178
 179         msg(MSG_DEBUG, "%i entries in total\n", mhash->count);
 180 }
 181 #endif
 182
 183 /* Creates a metaentry for the file/dir/etc at path */
 184 struct metaentry *
 185 mentry_create(const char *path)
 186 {
 187         ssize_t lsize, vsize;
 188         char *list, *attr;
 189         struct stat sbuf;
 190         struct passwd *pbuf;
 191         struct group *gbuf;
 192         int i;
 193         struct metaentry *mentry;
 194
 195         if (lstat(path, &sbuf)) {
 196                 msg(MSG_ERROR, "lstat failed for %s: %s\n",
 197                     path, strerror(errno));
 198                 return NULL;
 199         }
 200
 201         pbuf = xgetpwuid(sbuf.st_uid);
 202         if (!pbuf) {
 203                 msg(MSG_ERROR, "getpwuid failed for %s: uid %i not found\n",
 204                     path, (int)sbuf.st_uid);
 205                 return NULL;
 206         }
 207
 208         gbuf = xgetgrgid(sbuf.st_gid);
 209         if (!gbuf) {
 210                 msg(MSG_ERROR, "getgrgid failed for %s: gid %i not found\n",
 211                     path, (int)sbuf.st_gid);
 212                 return NULL;
 213         }
 214
 215         mentry = mentry_alloc();
 216         mentry->path = xstrdup(path);
 217         mentry->pathlen = strlen(mentry->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                 /* Perhaps the FS doesn't support xattrs? */
 231                 if (errno == ENOTSUP)
 232                         return mentry;
 233
 234                 msg(MSG_ERROR, "listxattr failed for %s: %s\n",
 235                     path, strerror(errno));
 236                 return NULL;
 237         }
 238
 239         list = xmalloc(lsize);
 240         lsize = listxattr(path, list, lsize);
 241         if (lsize < 0) {
 242                 msg(MSG_ERROR, "listxattr failed for %s: %s\n",
 243                     path, strerror(errno));
 244                 free(list);
 245                 return NULL;
 246         }
 247
 248         i = 0;
 249         for (attr = list; attr < list + lsize; attr = strchr(attr, '\0') + 1) {
 250                 if (*attr == '\0')
 251                         continue;
 252                 i++;
 253         }
 254
 255         if (i == 0)
 256                 return mentry;
 257
 258         mentry->xattrs = i;
 259         mentry->xattr_names = xmalloc(i * sizeof(char *));
 260         mentry->xattr_values = xmalloc(i * sizeof(char *));
 261         mentry->xattr_lvalues = xmalloc(i * sizeof(ssize_t));
 262
 263         i = 0;
 264         for (attr = list; attr < list + lsize; attr = strchr(attr, '\0') + 1) {
 265                 if (*attr == '\0')
 266                         continue;
 267
 268                 mentry->xattr_names[i] = xstrdup(attr);
 269                 vsize = getxattr(path, attr, NULL, 0);
 270                 if (vsize < 0) {
 271                         msg(MSG_ERROR, "getxattr failed for %s: %s\n",
 272                             path, strerror(errno));
 273                         free(list);
 274                         mentry_free(mentry);
 275                         return NULL;
 276                 }
 277
 278                 mentry->xattr_lvalues[i] = vsize;
 279                 mentry->xattr_values[i] = xmalloc(vsize);
 280
 281                 vsize = getxattr(path, attr, mentry->xattr_values[i], vsize);
 282                 if (vsize < 0) {
 283                         msg(MSG_ERROR, "getxattr failed for %s: %s\n",
 284                             path, strerror(errno));
 285                         free(list);
 286                         mentry_free(mentry);
 287                         return NULL;
 288                 }
 289                 i++;
 290         }
 291
 292         free(list);
 293         return mentry;
 294 }
 295
 296 /* Cleans up a path and makes it relative to current working dir unless it is absolute */
 297 static char *
 298 normalize_path(const char *orig)
 299 {
 300         char *real = realpath(orig, NULL);
 301         char cwd[PATH_MAX];
 302         char *result;
 303
 304         getcwd(cwd, PATH_MAX);
 305         if (!real)
 306                 return NULL;
 307
 308         if (!strncmp(real, cwd, strlen(cwd))) {
 309                 result = xmalloc(strlen(real) - strlen(cwd) + 1 + 1);
 310                 result[0] = '\0';
 311                 strcat(result, ".");
 312                 strcat(result, real + strlen(cwd));
 313         } else {
 314                 result = xstrdup(real);
 315         }
 316
 317         free(real);
 318         return result;
 319 }
 320
 321 /* Internal function for the recursive path walk */
 322 static void
 323 mentries_recurse(const char *path, struct metahash *mhash, msettings *st)
 324 {
 325         struct stat sbuf;
 326         struct metaentry *mentry;
 327         char tpath[PATH_MAX];
 328         DIR *dir;
 329         struct dirent *dent;
 330
 331         if (!path)
 332                 return;
 333
 334         if (lstat(path, &sbuf)) {
 335                 msg(MSG_ERROR, "lstat failed for %s: %s\n",
 336                     path, strerror(errno));
 337                 return;
 338         }
 339
 340         mentry = mentry_create(path);
 341         if (!mentry)
 342                 return;
 343
 344         mentry_insert(mentry, mhash);
 345
 346         if (S_ISDIR(sbuf.st_mode)) {
 347                 dir = opendir(path);
 348                 if (!dir) {
 349                         msg(MSG_ERROR, "opendir failed for %s: %s\n",
 350                             path, strerror(errno));
 351                         return;
 352                 }
 353
 354                 while ((dent = readdir(dir))) {
 355                         if (!strcmp(dent->d_name, ".") ||
 356                             !strcmp(dent->d_name, "..") ||
 357                             (!st->do_git && !strcmp(dent->d_name, ".git")))
 358                                 continue;
 359                         snprintf(tpath, PATH_MAX, "%s/%s", path, dent->d_name);
 360                         tpath[PATH_MAX - 1] = '\0';
 361                         mentries_recurse(tpath, mhash, st);
 362                 }
 363
 364                 closedir(dir);
 365         }
 366 }
 367
 368 /* Recurses opath and adds metadata entries to the metaentry list */
 369 void
 370 mentries_recurse_path(const char *opath, struct metahash **mhash, msettings *st)
 371 {
 372         char *path = normalize_path(opath);
 373
 374         if (!(*mhash))
 375                 *mhash = mhash_alloc();
 376         mentries_recurse(path, *mhash, st);
 377         free(path);
 378 }
 379
 380 /* Stores metaentries to a file */
 381 void
 382 mentries_tofile(const struct metahash *mhash, const char *path)
 383 {
 384         FILE *to;
 385         const struct metaentry *mentry;
 386         int key;
 387         unsigned i;
 388
 389         to = fopen(path, "w");
 390         if (!to) {
 391                 msg(MSG_CRITICAL, "Failed to open %s: %s\n",
 392                     path, strerror(errno));
 393                 exit(EXIT_FAILURE);
 394         }
 395
 396         write_binary_string(SIGNATURE, SIGNATURELEN, to);
 397         write_binary_string(VERSION, VERSIONLEN, to);
 398
 399         for (key = 0; key < HASH_INDEXES; key++) {
 400                 for (mentry = mhash->bucket[key]; mentry; mentry = mentry->next) {
 401                         write_string(mentry->path, to);
 402                         write_string(mentry->owner, to);
 403                         write_string(mentry->group, to);
 404                         write_int((uint64_t)mentry->mtime, 8, to);
 405                         write_int((uint64_t)mentry->mtimensec, 8, to);
 406                         write_int((uint64_t)mentry->mode, 2, to);
 407                         write_int(mentry->xattrs, 4, to);
 408                         for (i = 0; i < mentry->xattrs; i++) {
 409                                 write_string(mentry->xattr_names[i], to);
 410                                 write_int(mentry->xattr_lvalues[i], 4, to);
 411                                 write_binary_string(mentry->xattr_values[i],
 412                                                     mentry->xattr_lvalues[i], to);
 413                         }
 414                 }
 415         }
 416
 417         fclose(to);
 418 }
 419
 420 /* Creates a metaentry list from a file */
 421 void
 422 mentries_fromfile(struct metahash **mhash, const char *path)
 423 {
 424         struct metaentry *mentry;
 425         char *mmapstart;
 426         char *ptr;
 427         char *max;
 428         int fd;
 429         struct stat sbuf;
 430         unsigned i;
 431
 432         if (!(*mhash))
 433                 *mhash = mhash_alloc();
 434
 435         fd = open(path, O_RDONLY);
 436         if (fd < 0) {
 437                 msg(MSG_CRITICAL, "Failed to open %s: %s\n",
 438                     path, strerror(errno));
 439                 exit(EXIT_FAILURE);
 440         }
 441
 442         if (fstat(fd, &sbuf)) {
 443                 msg(MSG_CRITICAL, "Failed to stat %s: %s\n",
 444                     path, strerror(errno));
 445                 exit(EXIT_FAILURE);
 446         }
 447
 448         if (sbuf.st_size < (SIGNATURELEN + VERSIONLEN)) {
 449                 msg(MSG_CRITICAL, "File %s has an invalid size\n", path);
 450                 exit(EXIT_FAILURE);
 451         }
 452
 453         mmapstart = mmap(NULL, (size_t)sbuf.st_size, PROT_READ,
 454                          MAP_SHARED, fd, 0);
 455         if (mmapstart == MAP_FAILED) {
 456                 msg(MSG_CRITICAL, "Unable to mmap %s: %s\n",
 457                     path, strerror(errno));
 458                 exit(EXIT_FAILURE);
 459         }
 460         ptr = mmapstart;
 461         max = mmapstart + sbuf.st_size;
 462
 463         if (strncmp(ptr, SIGNATURE, SIGNATURELEN)) {
 464                 msg(MSG_CRITICAL, "Invalid signature for file %s\n", path);
 465                 goto out;
 466         }
 467         ptr += SIGNATURELEN;
 468
 469         if (strncmp(ptr, VERSION, VERSIONLEN)) {
 470                 msg(MSG_CRITICAL, "Invalid version of file %s\n", path);
 471                 goto out;
 472         }
 473         ptr += VERSIONLEN;
 474
 475         while (ptr < mmapstart + sbuf.st_size) {
 476                 if (*ptr == '\0') {
 477                         msg(MSG_CRITICAL, "Invalid characters in file %s\n",
 478                             path);
 479                         goto out;
 480                 }
 481
 482                 mentry = mentry_alloc();
 483                 mentry->path = read_string(&ptr, max);
 484                 mentry->pathlen = strlen(mentry->path);
 485                 mentry->owner = read_string(&ptr, max);
 486                 mentry->group = read_string(&ptr, max);
 487                 mentry->mtime = (time_t)read_int(&ptr, 8, max);
 488                 mentry->mtimensec = (time_t)read_int(&ptr, 8, max);
 489                 mentry->mode = (mode_t)read_int(&ptr, 2, max);
 490                 mentry->xattrs = (unsigned int)read_int(&ptr, 4, max);
 491
 492                 if (!mentry->xattrs) {
 493                         mentry_insert(mentry, *mhash);
 494                         continue;
 495                 }
 496
 497                 mentry->xattr_names = xmalloc(mentry->xattrs *
 498                                       sizeof(char *));
 499                 mentry->xattr_lvalues = xmalloc(mentry->xattrs *
 500                                         sizeof(int));
 501                 mentry->xattr_values = xmalloc(mentry->xattrs *
 502                                        sizeof(char *));
 503
 504                 for (i = 0; i < mentry->xattrs; i++) {
 505                         mentry->xattr_names[i] = read_string(&ptr, max);
 506                         mentry->xattr_lvalues[i] =
 507                                 (int)read_int(&ptr, 4, max);
 508                         mentry->xattr_values[i] =
 509                                 read_binary_string(&ptr,
 510                                                    mentry->xattr_lvalues[i],
 511                                                    max);
 512                 }
 513                 mentry_insert(mentry, *mhash);
 514         }
 515
 516 out:
 517         munmap(mmapstart, sbuf.st_size);
 518         close(fd);
 519 }
 520
 521 /* Searches haystack for an xattr matching xattr number n in needle */
 522 int
 523 mentry_find_xattr(struct metaentry *haystack, struct metaentry *needle,
 524                   unsigned n)
 525 {
 526         unsigned i;
 527
 528         for (i = 0; i < haystack->xattrs; i++) {
 529                 if (strcmp(haystack->xattr_names[i], needle->xattr_names[n]))
 530                         continue;
 531                 if (haystack->xattr_lvalues[i] != needle->xattr_lvalues[n])
 532                         return -1;
 533                 if (bcmp(haystack->xattr_values[i], needle->xattr_values[n],
 534                          needle->xattr_lvalues[n]))
 535                         return -1;
 536                 return i;
 537         }
 538         return -1;
 539 }
 540
 541 /* Returns zero if all xattrs in left and right match */
 542 static int
 543 mentry_compare_xattr(struct metaentry *left, struct metaentry *right)
 544 {
 545         unsigned i;
 546
 547         if (left->xattrs != right->xattrs)
 548                 return 1;
 549
 550         /* Make sure all xattrs in left are found in right and vice versa */
 551         for (i = 0; i < left->xattrs; i++) {
 552                 if (mentry_find_xattr(right, left, i) < 0 ||
 553                     mentry_find_xattr(left, right, i) < 0) {
 554                         return 1;
 555                 }
 556         }
 557
 558         return 0;
 559 }
 560
 561 /* Compares two metaentries and returns an int with a bitmask of differences */
 562 int
 563 mentry_compare(struct metaentry *left, struct metaentry *right, msettings *st)
 564 {
 565         int retval = DIFF_NONE;
 566
 567         if (!left || !right) {
 568                 msg(MSG_ERROR, "%s called with empty list\n", __FUNCTION__);
 569                 return -1;
 570         }
 571
 572         if (strcmp(left->path, right->path))
 573                 return -1;
 574
 575         if (strcmp(left->owner, right->owner))
 576                 retval |= DIFF_OWNER;
 577
 578         if (strcmp(left->group, right->group))
 579                 retval |= DIFF_GROUP;
 580
 581         if ((left->mode & 07777) != (right->mode & 07777))
 582                 retval |= DIFF_MODE;
 583
 584         if ((left->mode & S_IFMT) != (right->mode & S_IFMT))
 585                 retval |= DIFF_TYPE;
 586
 587         if (st->do_mtime && strcmp(left->path, st->metafile) &&
 588             (left->mtime != right->mtime ||
 589              left->mtimensec != right->mtimensec))
 590                 retval |= DIFF_MTIME;
 591
 592         if (mentry_compare_xattr(left, right)) {
 593                 retval |= DIFF_XATTR;
 594                 return retval;
 595         }
 596
 597         return retval;
 598 }
 599
 600 /* Compares lists of real and stored metadata and calls pfunc for each */
 601 void
 602 mentries_compare(struct metahash *mhashreal,
 603                  struct metahash *mhashstored,
 604                  void (*pfunc)
 605                  (struct metaentry *real, struct metaentry *stored, int cmp),
 606                  msettings *st)
 607 {
 608         struct metaentry *real, *stored;
 609         int key;
 610
 611         if (!mhashreal || !mhashstored) {
 612                 msg(MSG_ERROR, "%s called with empty list\n", __FUNCTION__);
 613                 return;
 614         }
 615
 616         for (key = 0; key < HASH_INDEXES; key++) {
 617                 for (real = mhashreal->bucket[key]; real; real = real->next) {
 618                         stored = mentry_find(real->path, mhashstored);
 619
 620                         if (!stored)
 621                                 pfunc(real, NULL, DIFF_ADDED);
 622                         else
 623                                 pfunc(real, stored, mentry_compare(real, stored, st));
 624                 }
 625
 626                 for (stored = mhashstored->bucket[key]; stored; stored = stored->next) {
 627                         real = mentry_find(stored->path, mhashreal);
 628
 629                         if (!real)
 630                                 pfunc(NULL, stored, DIFF_DELE);
 631                 }
 632         }
 633 }
 634
 635 /* Dumps given metadata */
 636 void
 637 mentries_dump(struct metahash *mhash)
 638 {
 639         const struct metaentry *mentry;
 640         char mode[11 + 1] = "";
 641         char date[12 + 2 + 2 + 2*1 + 1 + 2 + 2 + 2 + 2*1 + 1] = "";
 642         char zone[5 + 1] = "";
 643         struct tm cal;
 644
 645         for (int key = 0; key < HASH_INDEXES; key++) {
 646                 for (mentry = mhash->bucket[key]; mentry; mentry = mentry->next) {
 647                         strmode(mentry->mode, mode);
 648                         localtime_r(&mentry->mtime, &cal);
 649                         strftime(date, sizeof(date), "%F %T", &cal);
 650                         strftime(zone, sizeof(zone), "%z", &cal);
 651                         printf("%s\t%s\t%s\t%s.%09ld %s\t%s%s\n",
 652                                mode,
 653                                mentry->owner, mentry->group,
 654                                date, mentry->mtimensec, zone,
 655                                mentry->path, S_ISDIR(mentry->mode) ? "/" : "");
 656                         for (int i = 0; i < mentry->xattrs; i++) {
 657                                 printf("\t\t\t\t%s%s\t%s=",
 658                                        mentry->path, S_ISDIR(mentry->mode) ? "/" : "",
 659                                        mentry->xattr_names[i]);
 660                                 ssize_t p = 0;
 661                                 for (; p < mentry->xattr_lvalues[i]; p++) {
 662                                         const char ch = mentry->xattr_values[i][p];
 663                                         if ((unsigned)(ch - 32) > 126 - 32) {
 664                                                 p = -1;
 665                                                 break;
 666                                         }
 667                                 }
 668                                 if (p >= 0)
 669                                         printf("\"%.*s\"\n",
 670                                                (int)mentry->xattr_lvalues[i],
 671                                                mentry->xattr_values[i]);
 672                                 else {
 673                                         printf("0x");
 674                                         for (p = 0; p < mentry->xattr_lvalues[i]; p++)
 675                                                 printf("%02hhx", (char)mentry->xattr_values[i][p]);
 676                                         printf("\n");
 677                                 }
 678                         }
 679                 }
 680         }
 681 }