fsck.c

   1 #include "cache.h"
   2 #include "object.h"
   3 #include "blob.h"
   4 #include "tree.h"
   5 #include "tree-walk.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "fsck.h"
   9 #include "utf8.h"
  10
  11 static int fsck_walk_tree(struct tree *tree, fsck_walk_func walk, void *data)
  12 {
  13         struct tree_desc desc;
  14         struct name_entry entry;
  15         int res = 0;
  16
  17         if (parse_tree(tree))
  18                 return -1;
  19
  20         init_tree_desc(&desc, tree->buffer, tree->size);
  21         while (tree_entry(&desc, &entry)) {
  22                 int result;
  23
  24                 if (S_ISGITLINK(entry.mode))
  25                         continue;
  26                 if (S_ISDIR(entry.mode))
  27                         result = walk(&lookup_tree(entry.sha1)->object, OBJ_TREE, data);
  28                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode))
  29                         result = walk(&lookup_blob(entry.sha1)->object, OBJ_BLOB, data);
  30                 else {
  31                         result = error("in tree %s: entry %s has bad mode %.6o",
  32                                         sha1_to_hex(tree->object.sha1), entry.path, entry.mode);
  33                 }
  34                 if (result < 0)
  35                         return result;
  36                 if (!res)
  37                         res = result;
  38         }
  39         return res;
  40 }
  41
  42 static int fsck_walk_commit(struct commit *commit, fsck_walk_func walk, void *data)
  43 {
  44         struct commit_list *parents;
  45         int res;
  46         int result;
  47
  48         if (parse_commit(commit))
  49                 return -1;
  50
  51         result = walk((struct object *)commit->tree, OBJ_TREE, data);
  52         if (result < 0)
  53                 return result;
  54         res = result;
  55
  56         parents = commit->parents;
  57         while (parents) {
  58                 result = walk((struct object *)parents->item, OBJ_COMMIT, data);
  59                 if (result < 0)
  60                         return result;
  61                 if (!res)
  62                         res = result;
  63                 parents = parents->next;
  64         }
  65         return res;
  66 }
  67
  68 static int fsck_walk_tag(struct tag *tag, fsck_walk_func walk, void *data)
  69 {
  70         if (parse_tag(tag))
  71                 return -1;
  72         return walk(tag->tagged, OBJ_ANY, data);
  73 }
  74
  75 int fsck_walk(struct object *obj, fsck_walk_func walk, void *data)
  76 {
  77         if (!obj)
  78                 return -1;
  79         switch (obj->type) {
  80         case OBJ_BLOB:
  81                 return 0;
  82         case OBJ_TREE:
  83                 return fsck_walk_tree((struct tree *)obj, walk, data);
  84         case OBJ_COMMIT:
  85                 return fsck_walk_commit((struct commit *)obj, walk, data);
  86         case OBJ_TAG:
  87                 return fsck_walk_tag((struct tag *)obj, walk, data);
  88         default:
  89                 error("Unknown object type for %s", sha1_to_hex(obj->sha1));
  90                 return -1;
  91         }
  92 }
  93
  94 /*
  95  * The entries in a tree are ordered in the _path_ order,
  96  * which means that a directory entry is ordered by adding
  97  * a slash to the end of it.
  98  *
  99  * So a directory called "a" is ordered _after_ a file
 100  * called "a.c", because "a/" sorts after "a.c".
 101  */
 102 #define TREE_UNORDERED (-1)
 103 #define TREE_HAS_DUPS  (-2)
 104
 105 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 106 {
 107         int len1 = strlen(name1);
 108         int len2 = strlen(name2);
 109         int len = len1 < len2 ? len1 : len2;
 110         unsigned char c1, c2;
 111         int cmp;
 112
 113         cmp = memcmp(name1, name2, len);
 114         if (cmp < 0)
 115                 return 0;
 116         if (cmp > 0)
 117                 return TREE_UNORDERED;
 118
 119         /*
 120          * Ok, the first <len> characters are the same.
 121          * Now we need to order the next one, but turn
 122          * a '\0' into a '/' for a directory entry.
 123          */
 124         c1 = name1[len];
 125         c2 = name2[len];
 126         if (!c1 && !c2)
 127                 /*
 128                  * git-write-tree used to write out a nonsense tree that has
 129                  * entries with the same name, one blob and one tree.  Make
 130                  * sure we do not have duplicate entries.
 131                  */
 132                 return TREE_HAS_DUPS;
 133         if (!c1 && S_ISDIR(mode1))
 134                 c1 = '/';
 135         if (!c2 && S_ISDIR(mode2))
 136                 c2 = '/';
 137         return c1 < c2 ? 0 : TREE_UNORDERED;
 138 }
 139
 140 static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
 141 {
 142         int retval;
 143         int has_null_sha1 = 0;
 144         int has_full_path = 0;
 145         int has_empty_name = 0;
 146         int has_dot = 0;
 147         int has_dotdot = 0;
 148         int has_dotgit = 0;
 149         int has_zero_pad = 0;
 150         int has_bad_modes = 0;
 151         int has_dup_entries = 0;
 152         int not_properly_sorted = 0;
 153         struct tree_desc desc;
 154         unsigned o_mode;
 155         const char *o_name;
 156
 157         init_tree_desc(&desc, item->buffer, item->size);
 158
 159         o_mode = 0;
 160         o_name = NULL;
 161
 162         while (desc.size) {
 163                 unsigned mode;
 164                 const char *name;
 165                 const unsigned char *sha1;
 166
 167                 sha1 = tree_entry_extract(&desc, &name, &mode);
 168
 169                 if (is_null_sha1(sha1))
 170                         has_null_sha1 = 1;
 171                 if (strchr(name, '/'))
 172                         has_full_path = 1;
 173                 if (!*name)
 174                         has_empty_name = 1;
 175                 if (!strcmp(name, "."))
 176                         has_dot = 1;
 177                 if (!strcmp(name, ".."))
 178                         has_dotdot = 1;
 179                 if (!strcasecmp(name, ".git") || is_hfs_dotgit(name))
 180                         has_dotgit = 1;
 181                 has_zero_pad |= *(char *)desc.buffer == '0';
 182                 update_tree_entry(&desc);
 183
 184                 switch (mode) {
 185                 /*
 186                  * Standard modes..
 187                  */
 188                 case S_IFREG | 0755:
 189                 case S_IFREG | 0644:
 190                 case S_IFLNK:
 191                 case S_IFDIR:
 192                 case S_IFGITLINK:
 193                         break;
 194                 /*
 195                  * This is nonstandard, but we had a few of these
 196                  * early on when we honored the full set of mode
 197                  * bits..
 198                  */
 199                 case S_IFREG | 0664:
 200                         if (!strict)
 201                                 break;
 202                 default:
 203                         has_bad_modes = 1;
 204                 }
 205
 206                 if (o_name) {
 207                         switch (verify_ordered(o_mode, o_name, mode, name)) {
 208                         case TREE_UNORDERED:
 209                                 not_properly_sorted = 1;
 210                                 break;
 211                         case TREE_HAS_DUPS:
 212                                 has_dup_entries = 1;
 213                                 break;
 214                         default:
 215                                 break;
 216                         }
 217                 }
 218
 219                 o_mode = mode;
 220                 o_name = name;
 221         }
 222
 223         retval = 0;
 224         if (has_null_sha1)
 225                 retval += error_func(&item->object, FSCK_WARN, "contains entries pointing to null sha1");
 226         if (has_full_path)
 227                 retval += error_func(&item->object, FSCK_WARN, "contains full pathnames");
 228         if (has_empty_name)
 229                 retval += error_func(&item->object, FSCK_WARN, "contains empty pathname");
 230         if (has_dot)
 231                 retval += error_func(&item->object, FSCK_WARN, "contains '.'");
 232         if (has_dotdot)
 233                 retval += error_func(&item->object, FSCK_WARN, "contains '..'");
 234         if (has_dotgit)
 235                 retval += error_func(&item->object, FSCK_WARN, "contains '.git'");
 236         if (has_zero_pad)
 237                 retval += error_func(&item->object, FSCK_WARN, "contains zero-padded file modes");
 238         if (has_bad_modes)
 239                 retval += error_func(&item->object, FSCK_WARN, "contains bad file modes");
 240         if (has_dup_entries)
 241                 retval += error_func(&item->object, FSCK_ERROR, "contains duplicate file entries");
 242         if (not_properly_sorted)
 243                 retval += error_func(&item->object, FSCK_ERROR, "not properly sorted");
 244         return retval;
 245 }
 246
 247 static int fsck_ident(char **ident, struct object *obj, fsck_error error_func)
 248 {
 249         if (**ident == '<')
 250                 return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before email");
 251         *ident += strcspn(*ident, "<>\n");
 252         if (**ident == '>')
 253                 return error_func(obj, FSCK_ERROR, "invalid author/committer line - bad name");
 254         if (**ident != '<')
 255                 return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing email");
 256         if ((*ident)[-1] != ' ')
 257                 return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before email");
 258         (*ident)++;
 259         *ident += strcspn(*ident, "<>\n");
 260         if (**ident != '>')
 261                 return error_func(obj, FSCK_ERROR, "invalid author/committer line - bad email");
 262         (*ident)++;
 263         if (**ident != ' ')
 264                 return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before date");
 265         (*ident)++;
 266         if (**ident == '0' && (*ident)[1] != ' ')
 267                 return error_func(obj, FSCK_ERROR, "invalid author/committer line - zero-padded date");
 268         *ident += strspn(*ident, "0123456789");
 269         if (**ident != ' ')
 270                 return error_func(obj, FSCK_ERROR, "invalid author/committer line - bad date");
 271         (*ident)++;
 272         if ((**ident != '+' && **ident != '-') ||
 273             !isdigit((*ident)[1]) ||
 274             !isdigit((*ident)[2]) ||
 275             !isdigit((*ident)[3]) ||
 276             !isdigit((*ident)[4]) ||
 277             ((*ident)[5] != '\n'))
 278                 return error_func(obj, FSCK_ERROR, "invalid author/committer line - bad time zone");
 279         (*ident) += 6;
 280         return 0;
 281 }
 282
 283 static int fsck_commit(struct commit *commit, fsck_error error_func)
 284 {
 285         char *buffer = commit->buffer;
 286         unsigned char tree_sha1[20], sha1[20];
 287         struct commit_graft *graft;
 288         int parents = 0;
 289         int err;
 290
 291         if (commit->date == ULONG_MAX)
 292                 return error_func(&commit->object, FSCK_ERROR, "invalid author/committer line");
 293
 294         if (memcmp(buffer, "tree ", 5))
 295                 return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'tree' line");
 296         if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
 297                 return error_func(&commit->object, FSCK_ERROR, "invalid 'tree' line format - bad sha1");
 298         buffer += 46;
 299         while (!memcmp(buffer, "parent ", 7)) {
 300                 if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
 301                         return error_func(&commit->object, FSCK_ERROR, "invalid 'parent' line format - bad sha1");
 302                 buffer += 48;
 303                 parents++;
 304         }
 305         graft = lookup_commit_graft(commit->object.sha1);
 306         if (graft) {
 307                 struct commit_list *p = commit->parents;
 308                 parents = 0;
 309                 while (p) {
 310                         p = p->next;
 311                         parents++;
 312                 }
 313                 if (graft->nr_parent == -1 && !parents)
 314                         ; /* shallow commit */
 315                 else if (graft->nr_parent != parents)
 316                         return error_func(&commit->object, FSCK_ERROR, "graft objects missing");
 317         } else {
 318                 struct commit_list *p = commit->parents;
 319                 while (p && parents) {
 320                         p = p->next;
 321                         parents--;
 322                 }
 323                 if (p || parents)
 324                         return error_func(&commit->object, FSCK_ERROR, "parent objects missing");
 325         }
 326         if (memcmp(buffer, "author ", 7))
 327                 return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'author' line");
 328         buffer += 7;
 329         err = fsck_ident(&buffer, &commit->object, error_func);
 330         if (err)
 331                 return err;
 332         if (memcmp(buffer, "committer ", strlen("committer ")))
 333                 return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'committer' line");
 334         buffer += strlen("committer ");
 335         err = fsck_ident(&buffer, &commit->object, error_func);
 336         if (err)
 337                 return err;
 338         if (!commit->tree)
 339                 return error_func(&commit->object, FSCK_ERROR, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
 340
 341         return 0;
 342 }
 343
 344 static int fsck_tag(struct tag *tag, fsck_error error_func)
 345 {
 346         struct object *tagged = tag->tagged;
 347
 348         if (!tagged)
 349                 return error_func(&tag->object, FSCK_ERROR, "could not load tagged object");
 350         return 0;
 351 }
 352
 353 int fsck_object(struct object *obj, int strict, fsck_error error_func)
 354 {
 355         if (!obj)
 356                 return error_func(obj, FSCK_ERROR, "no valid object to fsck");
 357
 358         if (obj->type == OBJ_BLOB)
 359                 return 0;
 360         if (obj->type == OBJ_TREE)
 361                 return fsck_tree((struct tree *) obj, strict, error_func);
 362         if (obj->type == OBJ_COMMIT)
 363                 return fsck_commit((struct commit *) obj, error_func);
 364         if (obj->type == OBJ_TAG)
 365                 return fsck_tag((struct tag *) obj, error_func);
 366
 367         return error_func(obj, FSCK_ERROR, "unknown type '%d' (internal fsck error)",
 368                           obj->type);
 369 }
 370
 371 int fsck_error_function(struct object *obj, int type, const char *fmt, ...)
 372 {
 373         va_list ap;
 374         struct strbuf sb = STRBUF_INIT;
 375
 376         strbuf_addf(&sb, "object %s:", sha1_to_hex(obj->sha1));
 377
 378         va_start(ap, fmt);
 379         strbuf_vaddf(&sb, fmt, ap);
 380         va_end(ap);
 381
 382         error("%s", sb.buf);
 383         strbuf_release(&sb);
 384         return 1;
 385 }