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