update-cache.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7
   8 /*
   9  * Default to not allowing changes to the list of files. The
  10  * tool doesn't actually care, but this makes it harder to add
  11  * files to the revision control by mistake by doing something
  12  * like "git-update-cache *" and suddenly having all the object
  13  * files be revision controlled.
  14  */
  15 static int allow_add = 0, allow_remove = 0, allow_replace = 0, not_new = 0, quiet = 0, info_only = 0;
  16 static int force_remove;
  17
  18 /* Three functions to allow overloaded pointer return; see linux/err.h */
  19 static inline void *ERR_PTR(long error)
  20 {
  21         return (void *) error;
  22 }
  23
  24 static inline long PTR_ERR(const void *ptr)
  25 {
  26         return (long) ptr;
  27 }
  28
  29 static inline long IS_ERR(const void *ptr)
  30 {
  31         return (unsigned long)ptr > (unsigned long)-1000L;
  32 }
  33
  34 static int add_file_to_cache(char *path)
  35 {
  36         int size, namelen, option, status;
  37         struct cache_entry *ce;
  38         struct stat st;
  39         int fd;
  40         char *target;
  41
  42         status = lstat(path, &st);
  43         if (status < 0 || S_ISDIR(st.st_mode)) {
  44                 /* When we used to have "path" and now we want to add
  45                  * "path/file", we need a way to remove "path" before
  46                  * being able to add "path/file".  However,
  47                  * "git-update-cache --remove path" would not work.
  48                  * --force-remove can be used but this is more user
  49                  * friendly, especially since we can do the opposite
  50                  * case just fine without --force-remove.
  51                  */
  52                 if (status == 0 || (errno == ENOENT || errno == ENOTDIR)) {
  53                         if (allow_remove)
  54                                 return remove_file_from_cache(path);
  55                 }
  56                 return error("open(\"%s\"): %s", path, strerror(errno));
  57         }
  58         namelen = strlen(path);
  59         size = cache_entry_size(namelen);
  60         ce = xmalloc(size);
  61         memset(ce, 0, size);
  62         memcpy(ce->name, path, namelen);
  63         fill_stat_cache_info(ce, &st);
  64         ce->ce_mode = create_ce_mode(st.st_mode);
  65         ce->ce_flags = htons(namelen);
  66         switch (st.st_mode & S_IFMT) {
  67         case S_IFREG:
  68                 fd = open(path, O_RDONLY);
  69                 if (fd < 0)
  70                         return -1;
  71                 if (index_fd(ce->sha1, fd, &st, !info_only, NULL) < 0)
  72                         return -1;
  73                 break;
  74         case S_IFLNK:
  75                 target = xmalloc(st.st_size+1);
  76                 if (readlink(path, target, st.st_size+1) != st.st_size) {
  77                         free(target);
  78                         return -1;
  79                 }
  80                 if (info_only) {
  81                         unsigned char hdr[50];
  82                         int hdrlen;
  83                         write_sha1_file_prepare(target, st.st_size, "blob",
  84                                                 ce->sha1, hdr, &hdrlen);
  85                 } else if (write_sha1_file(target, st.st_size, "blob", ce->sha1))
  86                         return -1;
  87                 free(target);
  88                 break;
  89         default:
  90                 return -1;
  91         }
  92         option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
  93         option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
  94         return add_cache_entry(ce, option);
  95 }
  96
  97 static int compare_data(struct cache_entry *ce, struct stat *st)
  98 {
  99         int match = -1;
 100         int fd = open(ce->name, O_RDONLY);
 101
 102         if (fd >= 0) {
 103                 unsigned char sha1[20];
 104                 if (!index_fd(sha1, fd, st, 0, NULL))
 105                         match = memcmp(sha1, ce->sha1, 20);
 106                 close(fd);
 107         }
 108         return match;
 109 }
 110
 111 static int compare_link(struct cache_entry *ce, unsigned long expected_size)
 112 {
 113         int match = -1;
 114         char *target;
 115         void *buffer;
 116         unsigned long size;
 117         char type[10];
 118         int len;
 119
 120         target = xmalloc(expected_size);
 121         len = readlink(ce->name, target, expected_size);
 122         if (len != expected_size) {
 123                 free(target);
 124                 return -1;
 125         }
 126         buffer = read_sha1_file(ce->sha1, type, &size);
 127         if (!buffer) {
 128                 free(target);
 129                 return -1;
 130         }
 131         if (size == expected_size)
 132                 match = memcmp(buffer, target, size);
 133         free(buffer);
 134         free(target);
 135         return match;
 136 }
 137
 138 /*
 139  * "refresh" does not calculate a new sha1 file or bring the
 140  * cache up-to-date for mode/content changes. But what it
 141  * _does_ do is to "re-match" the stat information of a file
 142  * with the cache, so that you can refresh the cache for a
 143  * file that hasn't been changed but where the stat entry is
 144  * out of date.
 145  *
 146  * For example, you'd want to do this after doing a "git-read-tree",
 147  * to link up the stat cache details with the proper files.
 148  */
 149 static struct cache_entry *refresh_entry(struct cache_entry *ce)
 150 {
 151         struct stat st;
 152         struct cache_entry *updated;
 153         int changed, size;
 154
 155         if (lstat(ce->name, &st) < 0)
 156                 return ERR_PTR(-errno);
 157
 158         changed = ce_match_stat(ce, &st);
 159         if (!changed)
 160                 return ce;
 161
 162         /*
 163          * If the mode or type has changed, there's no point in trying
 164          * to refresh the entry - it's not going to match
 165          */
 166         if (changed & (MODE_CHANGED | TYPE_CHANGED))
 167                 return ERR_PTR(-EINVAL);
 168
 169         switch (st.st_mode & S_IFMT) {
 170         case S_IFREG:
 171                 if (compare_data(ce, &st))
 172                         return ERR_PTR(-EINVAL);
 173                 break;
 174         case S_IFLNK:
 175                 if (compare_link(ce, st.st_size))
 176                         return ERR_PTR(-EINVAL);
 177                 break;
 178         default:
 179                 return ERR_PTR(-EINVAL);
 180         }
 181
 182         size = ce_size(ce);
 183         updated = xmalloc(size);
 184         memcpy(updated, ce, size);
 185         fill_stat_cache_info(updated, &st);
 186         return updated;
 187 }
 188
 189 static int refresh_cache(void)
 190 {
 191         int i;
 192         int has_errors = 0;
 193
 194         for (i = 0; i < active_nr; i++) {
 195                 struct cache_entry *ce, *new;
 196                 ce = active_cache[i];
 197                 if (ce_stage(ce)) {
 198                         printf("%s: needs merge\n", ce->name);
 199                         has_errors = 1;
 200                         while ((i < active_nr) &&
 201                                ! strcmp(active_cache[i]->name, ce->name))
 202                                 i++;
 203                         i--;
 204                         continue;
 205                 }
 206
 207                 new = refresh_entry(ce);
 208                 if (IS_ERR(new)) {
 209                         if (not_new && PTR_ERR(new) == -ENOENT)
 210                                 continue;
 211                         if (quiet)
 212                                 continue;
 213                         printf("%s: needs update\n", ce->name);
 214                         has_errors = 1;
 215                         continue;
 216                 }
 217                 active_cache_changed = 1;
 218                 /* You can NOT just free active_cache[i] here, since it
 219                  * might not be necessarily malloc()ed but can also come
 220                  * from mmap(). */
 221                 active_cache[i] = new;
 222         }
 223         return has_errors;
 224 }
 225
 226 /*
 227  * We fundamentally don't like some paths: we don't want
 228  * dot or dot-dot anywhere, and for obvious reasons don't
 229  * want to recurse into ".git" either.
 230  *
 231  * Also, we don't want double slashes or slashes at the
 232  * end that can make pathnames ambiguous.
 233  */
 234 static int verify_dotfile(const char *rest)
 235 {
 236         /*
 237          * The first character was '.', but that
 238          * has already been discarded, we now test
 239          * the rest.
 240          */
 241         switch (*rest) {
 242         /* "." is not allowed */
 243         case '\0': case '/':
 244                 return 0;
 245
 246         /*
 247          * ".git" followed by  NUL or slash is bad. This
 248          * shares the path end test with the ".." case.
 249          */
 250         case 'g':
 251                 if (rest[1] != 'i')
 252                         break;
 253                 if (rest[2] != 't')
 254                         break;
 255                 rest += 2;
 256         /* fallthrough */
 257         case '.':
 258                 if (rest[1] == '\0' || rest[1] == '/')
 259                         return 0;
 260         }
 261         return 1;
 262 }
 263
 264 static int verify_path(char *path)
 265 {
 266         char c;
 267
 268         goto inside;
 269         for (;;) {
 270                 if (!c)
 271                         return 1;
 272                 if (c == '/') {
 273 inside:
 274                         c = *path++;
 275                         switch (c) {
 276                         default:
 277                                 continue;
 278                         case '/': case '\0':
 279                                 break;
 280                         case '.':
 281                                 if (verify_dotfile(path))
 282                                         continue;
 283                         }
 284                         return 0;
 285                 }
 286                 c = *path++;
 287         }
 288 }
 289
 290 static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
 291 {
 292         int size, len, option;
 293         unsigned int mode;
 294         unsigned char sha1[20];
 295         struct cache_entry *ce;
 296
 297         if (sscanf(arg1, "%o", &mode) != 1)
 298                 return -1;
 299         if (get_sha1_hex(arg2, sha1))
 300                 return -1;
 301         if (!verify_path(arg3))
 302                 return -1;
 303
 304         len = strlen(arg3);
 305         size = cache_entry_size(len);
 306         ce = xmalloc(size);
 307         memset(ce, 0, size);
 308
 309         memcpy(ce->sha1, sha1, 20);
 310         memcpy(ce->name, arg3, len);
 311         ce->ce_flags = htons(len);
 312         ce->ce_mode = create_ce_mode(mode);
 313         option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
 314         option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
 315         return add_cache_entry(ce, option);
 316 }
 317
 318 static struct cache_file cache_file;
 319
 320 int main(int argc, char **argv)
 321 {
 322         int i, newfd, entries, has_errors = 0;
 323         int allow_options = 1;
 324
 325         newfd = hold_index_file_for_update(&cache_file, get_index_file());
 326         if (newfd < 0)
 327                 die("unable to create new cachefile");
 328
 329         entries = read_cache();
 330         if (entries < 0)
 331                 die("cache corrupted");
 332
 333         for (i = 1 ; i < argc; i++) {
 334                 char *path = argv[i];
 335
 336                 if (allow_options && *path == '-') {
 337                         if (!strcmp(path, "--")) {
 338                                 allow_options = 0;
 339                                 continue;
 340                         }
 341                         if (!strcmp(path, "-q")) {
 342                                 quiet = 1;
 343                                 continue;
 344                         }
 345                         if (!strcmp(path, "--add")) {
 346                                 allow_add = 1;
 347                                 continue;
 348                         }
 349                         if (!strcmp(path, "--replace")) {
 350                                 allow_replace = 1;
 351                                 continue;
 352                         }
 353                         if (!strcmp(path, "--remove")) {
 354                                 allow_remove = 1;
 355                                 continue;
 356                         }
 357                         if (!strcmp(path, "--refresh")) {
 358                                 has_errors |= refresh_cache();
 359                                 continue;
 360                         }
 361                         if (!strcmp(path, "--cacheinfo")) {
 362                                 if (i+3 >= argc)
 363                                         die("git-update-cache: --cacheinfo <mode> <sha1> <path>");
 364                                 if (add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
 365                                         die("git-update-cache: --cacheinfo cannot add %s", argv[i+3]);
 366                                 i += 3;
 367                                 continue;
 368                         }
 369                         if (!strcmp(path, "--info-only")) {
 370                                 info_only = 1;
 371                                 continue;
 372                         }
 373                         if (!strcmp(path, "--force-remove")) {
 374                                 force_remove = 1;
 375                                 continue;
 376                         }
 377
 378                         if (!strcmp(path, "--ignore-missing")) {
 379                                 not_new = 1;
 380                                 continue;
 381                         }
 382                         die("unknown option %s", path);
 383                 }
 384                 if (!verify_path(path)) {
 385                         fprintf(stderr, "Ignoring path %s\n", argv[i]);
 386                         continue;
 387                 }
 388                 if (force_remove) {
 389                         if (remove_file_from_cache(path))
 390                                 die("git-update-cache: --force-remove cannot remove %s", path);
 391                         continue;
 392                 }
 393                 if (add_file_to_cache(path))
 394                         die("Unable to add %s to database", path);
 395         }
 396         if (write_cache(newfd, active_cache, active_nr) ||
 397             commit_index_file(&cache_file))
 398                 die("Unable to write new cachefile");
 399
 400         return has_errors ? 1 : 0;
 401 }