builtin-init-db.con commit branch: fix segfault when resolving an invalid HEAD (078f838)
   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 */
   6#include "cache.h"
   7#include "builtin.h"
   8
   9#ifndef DEFAULT_GIT_TEMPLATE_DIR
  10#define DEFAULT_GIT_TEMPLATE_DIR "/usr/share/git-core/templates/"
  11#endif
  12
  13#ifdef NO_TRUSTABLE_FILEMODE
  14#define TEST_FILEMODE 0
  15#else
  16#define TEST_FILEMODE 1
  17#endif
  18
  19static void safe_create_dir(const char *dir, int share)
  20{
  21        if (mkdir(dir, 0777) < 0) {
  22                if (errno != EEXIST) {
  23                        perror(dir);
  24                        exit(1);
  25                }
  26        }
  27        else if (share && adjust_shared_perm(dir))
  28                die("Could not make %s writable by group\n", dir);
  29}
  30
  31static int copy_file(const char *dst, const char *src, int mode)
  32{
  33        int fdi, fdo, status;
  34
  35        mode = (mode & 0111) ? 0777 : 0666;
  36        if ((fdi = open(src, O_RDONLY)) < 0)
  37                return fdi;
  38        if ((fdo = open(dst, O_WRONLY | O_CREAT | O_EXCL, mode)) < 0) {
  39                close(fdi);
  40                return fdo;
  41        }
  42        status = copy_fd(fdi, fdo);
  43        close(fdo);
  44
  45        if (!status && adjust_shared_perm(dst))
  46                return -1;
  47
  48        return status;
  49}
  50
  51static void copy_templates_1(char *path, int baselen,
  52                             char *template, int template_baselen,
  53                             DIR *dir)
  54{
  55        struct dirent *de;
  56
  57        /* Note: if ".git/hooks" file exists in the repository being
  58         * re-initialized, /etc/core-git/templates/hooks/update would
  59         * cause git-init to fail here.  I think this is sane but
  60         * it means that the set of templates we ship by default, along
  61         * with the way the namespace under .git/ is organized, should
  62         * be really carefully chosen.
  63         */
  64        safe_create_dir(path, 1);
  65        while ((de = readdir(dir)) != NULL) {
  66                struct stat st_git, st_template;
  67                int namelen;
  68                int exists = 0;
  69
  70                if (de->d_name[0] == '.')
  71                        continue;
  72                namelen = strlen(de->d_name);
  73                if ((PATH_MAX <= baselen + namelen) ||
  74                    (PATH_MAX <= template_baselen + namelen))
  75                        die("insanely long template name %s", de->d_name);
  76                memcpy(path + baselen, de->d_name, namelen+1);
  77                memcpy(template + template_baselen, de->d_name, namelen+1);
  78                if (lstat(path, &st_git)) {
  79                        if (errno != ENOENT)
  80                                die("cannot stat %s", path);
  81                }
  82                else
  83                        exists = 1;
  84
  85                if (lstat(template, &st_template))
  86                        die("cannot stat template %s", template);
  87
  88                if (S_ISDIR(st_template.st_mode)) {
  89                        DIR *subdir = opendir(template);
  90                        int baselen_sub = baselen + namelen;
  91                        int template_baselen_sub = template_baselen + namelen;
  92                        if (!subdir)
  93                                die("cannot opendir %s", template);
  94                        path[baselen_sub++] =
  95                                template[template_baselen_sub++] = '/';
  96                        path[baselen_sub] =
  97                                template[template_baselen_sub] = 0;
  98                        copy_templates_1(path, baselen_sub,
  99                                         template, template_baselen_sub,
 100                                         subdir);
 101                        closedir(subdir);
 102                }
 103                else if (exists)
 104                        continue;
 105                else if (S_ISLNK(st_template.st_mode)) {
 106                        char lnk[256];
 107                        int len;
 108                        len = readlink(template, lnk, sizeof(lnk));
 109                        if (len < 0)
 110                                die("cannot readlink %s", template);
 111                        if (sizeof(lnk) <= len)
 112                                die("insanely long symlink %s", template);
 113                        lnk[len] = 0;
 114                        if (symlink(lnk, path))
 115                                die("cannot symlink %s %s", lnk, path);
 116                }
 117                else if (S_ISREG(st_template.st_mode)) {
 118                        if (copy_file(path, template, st_template.st_mode))
 119                                die("cannot copy %s to %s", template, path);
 120                }
 121                else
 122                        error("ignoring template %s", template);
 123        }
 124}
 125
 126static void copy_templates(const char *git_dir, int len, const char *template_dir)
 127{
 128        char path[PATH_MAX];
 129        char template_path[PATH_MAX];
 130        int template_len;
 131        DIR *dir;
 132
 133        if (!template_dir) {
 134                template_dir = getenv(TEMPLATE_DIR_ENVIRONMENT);
 135                if (!template_dir)
 136                        template_dir = DEFAULT_GIT_TEMPLATE_DIR;
 137        }
 138        strcpy(template_path, template_dir);
 139        template_len = strlen(template_path);
 140        if (template_path[template_len-1] != '/') {
 141                template_path[template_len++] = '/';
 142                template_path[template_len] = 0;
 143        }
 144        dir = opendir(template_path);
 145        if (!dir) {
 146                fprintf(stderr, "warning: templates not found %s\n",
 147                        template_dir);
 148                return;
 149        }
 150
 151        /* Make sure that template is from the correct vintage */
 152        strcpy(template_path + template_len, "config");
 153        repository_format_version = 0;
 154        git_config_from_file(check_repository_format_version,
 155                             template_path);
 156        template_path[template_len] = 0;
 157
 158        if (repository_format_version &&
 159            repository_format_version != GIT_REPO_VERSION) {
 160                fprintf(stderr, "warning: not copying templates of "
 161                        "a wrong format version %d from '%s'\n",
 162                        repository_format_version,
 163                        template_dir);
 164                closedir(dir);
 165                return;
 166        }
 167
 168        memcpy(path, git_dir, len);
 169        path[len] = 0;
 170        copy_templates_1(path, len,
 171                         template_path, template_len,
 172                         dir);
 173        closedir(dir);
 174}
 175
 176static int create_default_files(const char *git_dir, const char *template_path)
 177{
 178        unsigned len = strlen(git_dir);
 179        static char path[PATH_MAX];
 180        unsigned char sha1[20];
 181        struct stat st1;
 182        char repo_version_string[10];
 183        int reinit;
 184        int filemode;
 185
 186        if (len > sizeof(path)-50)
 187                die("insane git directory %s", git_dir);
 188        memcpy(path, git_dir, len);
 189
 190        if (len && path[len-1] != '/')
 191                path[len++] = '/';
 192
 193        /*
 194         * Create .git/refs/{heads,tags}
 195         */
 196        strcpy(path + len, "refs");
 197        safe_create_dir(path, 1);
 198        strcpy(path + len, "refs/heads");
 199        safe_create_dir(path, 1);
 200        strcpy(path + len, "refs/tags");
 201        safe_create_dir(path, 1);
 202
 203        /* First copy the templates -- we might have the default
 204         * config file there, in which case we would want to read
 205         * from it after installing.
 206         */
 207        path[len] = 0;
 208        copy_templates(path, len, template_path);
 209
 210        git_config(git_default_config);
 211
 212        /*
 213         * We would have created the above under user's umask -- under
 214         * shared-repository settings, we would need to fix them up.
 215         */
 216        if (shared_repository) {
 217                path[len] = 0;
 218                adjust_shared_perm(path);
 219                strcpy(path + len, "refs");
 220                adjust_shared_perm(path);
 221                strcpy(path + len, "refs/heads");
 222                adjust_shared_perm(path);
 223                strcpy(path + len, "refs/tags");
 224                adjust_shared_perm(path);
 225        }
 226
 227        /*
 228         * Create the default symlink from ".git/HEAD" to the "master"
 229         * branch, if it does not exist yet.
 230         */
 231        strcpy(path + len, "HEAD");
 232        reinit = !read_ref("HEAD", sha1);
 233        if (!reinit) {
 234                if (create_symref("HEAD", "refs/heads/master", NULL) < 0)
 235                        exit(1);
 236        }
 237
 238        /* This forces creation of new config file */
 239        sprintf(repo_version_string, "%d", GIT_REPO_VERSION);
 240        git_config_set("core.repositoryformatversion", repo_version_string);
 241
 242        path[len] = 0;
 243        strcpy(path + len, "config");
 244
 245        /* Check filemode trustability */
 246        filemode = TEST_FILEMODE;
 247        if (TEST_FILEMODE && !lstat(path, &st1)) {
 248                struct stat st2;
 249                filemode = (!chmod(path, st1.st_mode ^ S_IXUSR) &&
 250                                !lstat(path, &st2) &&
 251                                st1.st_mode != st2.st_mode);
 252        }
 253        git_config_set("core.filemode", filemode ? "true" : "false");
 254
 255        if (is_bare_repository()) {
 256                git_config_set("core.bare", "true");
 257        }
 258        else {
 259                git_config_set("core.bare", "false");
 260                /* allow template config file to override the default */
 261                if (log_all_ref_updates == -1)
 262                    git_config_set("core.logallrefupdates", "true");
 263        }
 264        return reinit;
 265}
 266
 267static const char init_db_usage[] =
 268"git-init [--template=<template-directory>] [--shared]";
 269
 270/*
 271 * If you want to, you can share the DB area with any number of branches.
 272 * That has advantages: you can save space by sharing all the SHA1 objects.
 273 * On the other hand, it might just make lookup slower and messier. You
 274 * be the judge.  The default case is to have one DB per managed directory.
 275 */
 276int cmd_init_db(int argc, const char **argv, const char *prefix)
 277{
 278        const char *git_dir;
 279        const char *sha1_dir;
 280        const char *template_dir = NULL;
 281        char *path;
 282        int len, i, reinit;
 283
 284        for (i = 1; i < argc; i++, argv++) {
 285                const char *arg = argv[1];
 286                if (!prefixcmp(arg, "--template="))
 287                        template_dir = arg+11;
 288                else if (!strcmp(arg, "--shared"))
 289                        shared_repository = PERM_GROUP;
 290                else if (!prefixcmp(arg, "--shared="))
 291                        shared_repository = git_config_perm("arg", arg+9);
 292                else
 293                        usage(init_db_usage);
 294        }
 295
 296        /*
 297         * Set up the default .git directory contents
 298         */
 299        git_dir = getenv(GIT_DIR_ENVIRONMENT);
 300        if (!git_dir)
 301                git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 302        safe_create_dir(git_dir, 0);
 303
 304        /* Check to see if the repository version is right.
 305         * Note that a newly created repository does not have
 306         * config file, so this will not fail.  What we are catching
 307         * is an attempt to reinitialize new repository with an old tool.
 308         */
 309        check_repository_format();
 310
 311        reinit = create_default_files(git_dir, template_dir);
 312
 313        /*
 314         * And set up the object store.
 315         */
 316        sha1_dir = get_object_directory();
 317        len = strlen(sha1_dir);
 318        path = xmalloc(len + 40);
 319        memcpy(path, sha1_dir, len);
 320
 321        safe_create_dir(sha1_dir, 1);
 322        strcpy(path+len, "/pack");
 323        safe_create_dir(path, 1);
 324        strcpy(path+len, "/info");
 325        safe_create_dir(path, 1);
 326
 327        if (shared_repository) {
 328                char buf[10];
 329                /* We do not spell "group" and such, so that
 330                 * the configuration can be read by older version
 331                 * of git.
 332                 */
 333                sprintf(buf, "%d", shared_repository);
 334                git_config_set("core.sharedrepository", buf);
 335                git_config_set("receive.denyNonFastforwards", "true");
 336        }
 337
 338        printf("%s%s Git repository in %s/\n",
 339                reinit ? "Reinitialized existing" : "Initialized empty",
 340                shared_repository ? " shared" : "",
 341                git_dir);
 342
 343        return 0;
 344}