setup.c

   1 #include "cache.h"
   2
   3 const char *prefix_path(const char *prefix, int len, const char *path)
   4 {
   5         const char *orig = path;
   6         for (;;) {
   7                 char c;
   8                 if (*path != '.')
   9                         break;
  10                 c = path[1];
  11                 /* "." */
  12                 if (!c) {
  13                         path++;
  14                         break;
  15                 }
  16                 /* "./" */
  17                 if (c == '/') {
  18                         path += 2;
  19                         continue;
  20                 }
  21                 if (c != '.')
  22                         break;
  23                 c = path[2];
  24                 if (!c)
  25                         path += 2;
  26                 else if (c == '/')
  27                         path += 3;
  28                 else
  29                         break;
  30                 /* ".." and "../" */
  31                 /* Remove last component of the prefix */
  32                 do {
  33                         if (!len)
  34                                 die("'%s' is outside repository", orig);
  35                         len--;
  36                 } while (len && prefix[len-1] != '/');
  37                 continue;
  38         }
  39         if (len) {
  40                 int speclen = strlen(path);
  41                 char *n = xmalloc(speclen + len + 1);
  42
  43                 memcpy(n, prefix, len);
  44                 memcpy(n + len, path, speclen+1);
  45                 path = n;
  46         }
  47         return path;
  48 }
  49
  50 /*
  51  * Unlike prefix_path, this should be used if the named file does
  52  * not have to interact with index entry; i.e. name of a random file
  53  * on the filesystem.
  54  */
  55 const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
  56 {
  57         static char path[PATH_MAX];
  58         if (!pfx || !*pfx || arg[0] == '/')
  59                 return arg;
  60         memcpy(path, pfx, pfx_len);
  61         strcpy(path + pfx_len, arg);
  62         return path;
  63 }
  64
  65 /*
  66  * Verify a filename that we got as an argument for a pathspec
  67  * entry. Note that a filename that begins with "-" never verifies
  68  * as true, because even if such a filename were to exist, we want
  69  * it to be preceded by the "--" marker (or we want the user to
  70  * use a format like "./-filename")
  71  */
  72 void verify_filename(const char *prefix, const char *arg)
  73 {
  74         const char *name;
  75         struct stat st;
  76
  77         if (*arg == '-')
  78                 die("bad flag '%s' used after filename", arg);
  79         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
  80         if (!lstat(name, &st))
  81                 return;
  82         if (errno == ENOENT)
  83                 die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  84                     "Use '--' to separate paths from revisions", arg);
  85         die("'%s': %s", arg, strerror(errno));
  86 }
  87
  88 /*
  89  * Opposite of the above: the command line did not have -- marker
  90  * and we parsed the arg as a refname.  It should not be interpretable
  91  * as a filename.
  92  */
  93 void verify_non_filename(const char *prefix, const char *arg)
  94 {
  95         const char *name;
  96         struct stat st;
  97
  98         if (is_inside_git_dir())
  99                 return;
 100         if (*arg == '-')
 101                 return; /* flag */
 102         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
 103         if (!lstat(name, &st))
 104                 die("ambiguous argument '%s': both revision and filename\n"
 105                     "Use '--' to separate filenames from revisions", arg);
 106         if (errno != ENOENT)
 107                 die("'%s': %s", arg, strerror(errno));
 108 }
 109
 110 const char **get_pathspec(const char *prefix, const char **pathspec)
 111 {
 112         const char *entry = *pathspec;
 113         const char **p;
 114         int prefixlen;
 115
 116         if (!prefix && !entry)
 117                 return NULL;
 118
 119         if (!entry) {
 120                 static const char *spec[2];
 121                 spec[0] = prefix;
 122                 spec[1] = NULL;
 123                 return spec;
 124         }
 125
 126         /* Otherwise we have to re-write the entries.. */
 127         p = pathspec;
 128         prefixlen = prefix ? strlen(prefix) : 0;
 129         do {
 130                 *p = prefix_path(prefix, prefixlen, entry);
 131         } while ((entry = *++p) != NULL);
 132         return (const char **) pathspec;
 133 }
 134
 135 /*
 136  * Test if it looks like we're at a git directory.
 137  * We want to see:
 138  *
 139  *  - either a objects/ directory _or_ the proper
 140  *    GIT_OBJECT_DIRECTORY environment variable
 141  *  - a refs/ directory
 142  *  - either a HEAD symlink or a HEAD file that is formatted as
 143  *    a proper "ref:", or a regular file HEAD that has a properly
 144  *    formatted sha1 object name.
 145  */
 146 static int is_git_directory(const char *suspect)
 147 {
 148         char path[PATH_MAX];
 149         size_t len = strlen(suspect);
 150
 151         strcpy(path, suspect);
 152         if (getenv(DB_ENVIRONMENT)) {
 153                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 154                         return 0;
 155         }
 156         else {
 157                 strcpy(path + len, "/objects");
 158                 if (access(path, X_OK))
 159                         return 0;
 160         }
 161
 162         strcpy(path + len, "/refs");
 163         if (access(path, X_OK))
 164                 return 0;
 165
 166         strcpy(path + len, "/HEAD");
 167         if (validate_headref(path))
 168                 return 0;
 169
 170         return 1;
 171 }
 172
 173 static int inside_git_dir = -1;
 174
 175 int is_inside_git_dir(void)
 176 {
 177         if (inside_git_dir < 0) {
 178                 char buffer[1024];
 179
 180                 if (is_bare_repository())
 181                         return (inside_git_dir = 1);
 182                 if (getcwd(buffer, sizeof(buffer))) {
 183                         const char *git_dir = get_git_dir(), *cwd = buffer;
 184                         while (*git_dir && *git_dir == *cwd) {
 185                                 git_dir++;
 186                                 cwd++;
 187                         }
 188                         inside_git_dir = !*git_dir;
 189                 } else
 190                         inside_git_dir = 0;
 191         }
 192         return inside_git_dir;
 193 }
 194
 195 const char *setup_git_directory_gently(int *nongit_ok)
 196 {
 197         static char cwd[PATH_MAX+1];
 198         const char *gitdirenv;
 199         int len, offset;
 200
 201         /*
 202          * If GIT_DIR is set explicitly, we're not going
 203          * to do any discovery, but we still do repository
 204          * validation.
 205          */
 206         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 207         if (gitdirenv) {
 208                 if (PATH_MAX - 40 < strlen(gitdirenv))
 209                         die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 210                 if (is_git_directory(gitdirenv))
 211                         return NULL;
 212                 if (nongit_ok) {
 213                         *nongit_ok = 1;
 214                         return NULL;
 215                 }
 216                 die("Not a git repository: '%s'", gitdirenv);
 217         }
 218
 219         if (!getcwd(cwd, sizeof(cwd)-1) || cwd[0] != '/')
 220                 die("Unable to read current working directory");
 221
 222         offset = len = strlen(cwd);
 223         for (;;) {
 224                 if (is_git_directory(".git"))
 225                         break;
 226                 chdir("..");
 227                 do {
 228                         if (!offset) {
 229                                 if (is_git_directory(cwd)) {
 230                                         if (chdir(cwd))
 231                                                 die("Cannot come back to cwd");
 232                                         setenv(GIT_DIR_ENVIRONMENT, cwd, 1);
 233                                         inside_git_dir = 1;
 234                                         return NULL;
 235                                 }
 236                                 if (nongit_ok) {
 237                                         if (chdir(cwd))
 238                                                 die("Cannot come back to cwd");
 239                                         *nongit_ok = 1;
 240                                         return NULL;
 241                                 }
 242                                 die("Not a git repository");
 243                         }
 244                 } while (cwd[--offset] != '/');
 245         }
 246
 247         if (offset == len)
 248                 return NULL;
 249
 250         /* Make "offset" point to past the '/', and add a '/' at the end */
 251         offset++;
 252         cwd[len++] = '/';
 253         cwd[len] = 0;
 254         inside_git_dir = !strncmp(cwd + offset, ".git/", 5);
 255         return cwd + offset;
 256 }
 257
 258 int git_config_perm(const char *var, const char *value)
 259 {
 260         if (value) {
 261                 if (!strcmp(value, "umask"))
 262                         return PERM_UMASK;
 263                 if (!strcmp(value, "group"))
 264                         return PERM_GROUP;
 265                 if (!strcmp(value, "all") ||
 266                     !strcmp(value, "world") ||
 267                     !strcmp(value, "everybody"))
 268                         return PERM_EVERYBODY;
 269         }
 270         return git_config_bool(var, value);
 271 }
 272
 273 int check_repository_format_version(const char *var, const char *value)
 274 {
 275        if (strcmp(var, "core.repositoryformatversion") == 0)
 276                repository_format_version = git_config_int(var, value);
 277         else if (strcmp(var, "core.sharedrepository") == 0)
 278                 shared_repository = git_config_perm(var, value);
 279        return 0;
 280 }
 281
 282 int check_repository_format(void)
 283 {
 284         git_config(check_repository_format_version);
 285         if (GIT_REPO_VERSION < repository_format_version)
 286                 die ("Expected git repo version <= %d, found %d",
 287                      GIT_REPO_VERSION, repository_format_version);
 288         return 0;
 289 }
 290
 291 const char *setup_git_directory(void)
 292 {
 293         const char *retval = setup_git_directory_gently(NULL);
 294         check_repository_format();
 295         return retval;
 296 }