Andrew's git / gitweb.git / init-db.c
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init-db.con commit Test in git-init-db if the filemode can be trusted (e24317b)
   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 */
   6#include "cache.h"
   7
   8#ifndef DEFAULT_GIT_TEMPLATE_DIR
   9#define DEFAULT_GIT_TEMPLATE_DIR "/usr/share/git-core/templates/"
  10#endif
  11
  12static void safe_create_dir(const char *dir)
  13{
  14        if (mkdir(dir, 0777) < 0) {
  15                if (errno != EEXIST) {
  16                        perror(dir);
  17                        exit(1);
  18                }
  19        }
  20}
  21
  22static int copy_file(const char *dst, const char *src, int mode)
  23{
  24        int fdi, fdo;
  25
  26        mode = (mode & 0111) ? 0777 : 0666;
  27        if ((fdi = open(src, O_RDONLY)) < 0)
  28                return fdi;
  29        if ((fdo = open(dst, O_WRONLY | O_CREAT | O_EXCL, mode)) < 0) {
  30                close(fdi);
  31                return fdo;
  32        }
  33        while (1) {
  34                char buf[BUFSIZ];
  35                ssize_t leni, leno, ofs;
  36                leni = read(fdi, buf, sizeof(buf));
  37                if (leni < 0) {
  38                error_return:
  39                        close(fdo);
  40                        close(fdi);
  41                        return -1;
  42                }
  43                if (!leni)
  44                        break;
  45                ofs = 0;
  46                do {
  47                        leno = write(fdo, buf+ofs, leni);
  48                        if (leno < 0)
  49                                goto error_return;
  50                        leni -= leno;
  51                        ofs += leno;
  52                } while (0 < leni);
  53        }
  54        close(fdo);
  55        close(fdi);
  56        return 0;
  57}
  58
  59static void copy_templates_1(char *path, int baselen,
  60                             char *template, int template_baselen,
  61                             DIR *dir)
  62{
  63        struct dirent *de;
  64
  65        /* Note: if ".git/hooks" file exists in the repository being
  66         * re-initialized, /etc/core-git/templates/hooks/update would
  67         * cause git-init-db to fail here.  I think this is sane but
  68         * it means that the set of templates we ship by default, along
  69         * with the way the namespace under .git/ is organized, should
  70         * be really carefully chosen.
  71         */
  72        safe_create_dir(path);
  73        while ((de = readdir(dir)) != NULL) {
  74                struct stat st_git, st_template;
  75                int namelen;
  76                int exists = 0;
  77
  78                if (de->d_name[0] == '.')
  79                        continue;
  80                namelen = strlen(de->d_name);
  81                if ((PATH_MAX <= baselen + namelen) ||
  82                    (PATH_MAX <= template_baselen + namelen))
  83                        die("insanely long template name %s", de->d_name);
  84                memcpy(path + baselen, de->d_name, namelen+1);
  85                memcpy(template + template_baselen, de->d_name, namelen+1);
  86                if (lstat(path, &st_git)) {
  87                        if (errno != ENOENT)
  88                                die("cannot stat %s", path);
  89                }
  90                else
  91                        exists = 1;
  92
  93                if (lstat(template, &st_template))
  94                        die("cannot stat template %s", template);
  95
  96                if (S_ISDIR(st_template.st_mode)) {
  97                        DIR *subdir = opendir(template);
  98                        int baselen_sub = baselen + namelen;
  99                        int template_baselen_sub = template_baselen + namelen;
 100                        if (!subdir)
 101                                die("cannot opendir %s", template);
 102                        path[baselen_sub++] =
 103                                template[template_baselen_sub++] = '/';
 104                        path[baselen_sub] =
 105                                template[template_baselen_sub] = 0;
 106                        copy_templates_1(path, baselen_sub,
 107                                         template, template_baselen_sub,
 108                                         subdir);
 109                        closedir(subdir);
 110                }
 111                else if (exists)
 112                        continue;
 113                else if (S_ISLNK(st_template.st_mode)) {
 114                        char lnk[256];
 115                        int len;
 116                        len = readlink(template, lnk, sizeof(lnk));
 117                        if (len < 0)
 118                                die("cannot readlink %s", template);
 119                        if (sizeof(lnk) <= len)
 120                                die("insanely long symlink %s", template);
 121                        lnk[len] = 0;
 122                        if (symlink(lnk, path))
 123                                die("cannot symlink %s %s", lnk, path);
 124                }
 125                else if (S_ISREG(st_template.st_mode)) {
 126                        if (copy_file(path, template, st_template.st_mode))
 127                                die("cannot copy %s to %s", template, path);
 128                }
 129                else
 130                        error("ignoring template %s", template);
 131        }
 132}
 133
 134static void copy_templates(const char *git_dir, int len, char *template_dir)
 135{
 136        char path[PATH_MAX];
 137        char template_path[PATH_MAX];
 138        int template_len;
 139        DIR *dir;
 140
 141        if (!template_dir)
 142                template_dir = DEFAULT_GIT_TEMPLATE_DIR;
 143        strcpy(template_path, template_dir);
 144        template_len = strlen(template_path);
 145        if (template_path[template_len-1] != '/') {
 146                template_path[template_len++] = '/';
 147                template_path[template_len] = 0;
 148        }
 149        dir = opendir(template_path);
 150        if (!dir) {
 151                fprintf(stderr, "warning: templates not found %s\n",
 152                        template_dir);
 153                return;
 154        }
 155
 156        memcpy(path, git_dir, len);
 157        path[len] = 0;
 158        copy_templates_1(path, len,
 159                         template_path, template_len,
 160                         dir);
 161        closedir(dir);
 162}
 163
 164static void create_default_files(const char *git_dir,
 165                                 char *template_path)
 166{
 167        unsigned len = strlen(git_dir);
 168        static char path[PATH_MAX];
 169        unsigned char sha1[20];
 170
 171        if (len > sizeof(path)-50)
 172                die("insane git directory %s", git_dir);
 173        memcpy(path, git_dir, len);
 174
 175        if (len && path[len-1] != '/')
 176                path[len++] = '/';
 177
 178        /*
 179         * Create .git/refs/{heads,tags}
 180         */
 181        strcpy(path + len, "refs");
 182        safe_create_dir(path);
 183        strcpy(path + len, "refs/heads");
 184        safe_create_dir(path);
 185        strcpy(path + len, "refs/tags");
 186        safe_create_dir(path);
 187
 188        /*
 189         * Create the default symlink from ".git/HEAD" to the "master"
 190         * branch, if it does not exist yet.
 191         */
 192        strcpy(path + len, "HEAD");
 193        if (read_ref(path, sha1) < 0) {
 194                if (create_symref(path, "refs/heads/master") < 0)
 195                        exit(1);
 196        }
 197        path[len] = 0;
 198        copy_templates(path, len, template_path);
 199
 200        /*
 201         * Find out if we can trust the executable bit.
 202         */
 203        safe_create_dir(path);
 204        strcpy(path + len, "config");
 205        if (access(path, R_OK) < 0) {
 206                static const char contents[] =
 207                        "#\n"
 208                        "# This is the config file\n"
 209                        "#\n"
 210                        "\n"
 211                        "; core variables\n"
 212                        "[core]\n"
 213                        "       ; Don't trust file modes\n"
 214                        "       filemode = false\n"
 215                        "\n";
 216                FILE *config = fopen(path, "w");
 217                struct stat st;
 218
 219                if (!config)
 220                        die("Can not write to %s?", path);
 221
 222                fwrite(contents, sizeof(contents)-1, 1, config);
 223
 224                fclose(config);
 225
 226                if (!lstat(path, &st)) {
 227                        struct stat st2;
 228                        if (!chmod(path, st.st_mode ^ S_IXUSR) &&
 229                                        !lstat(path, &st2) &&
 230                                        st.st_mode != st2.st_mode)
 231                                unlink(path);
 232                        else
 233                                fprintf(stderr, "Ignoring file modes\n");
 234                }
 235        }
 236}
 237
 238static const char init_db_usage[] =
 239"git-init-db [--template=<template-directory>]";
 240
 241/*
 242 * If you want to, you can share the DB area with any number of branches.
 243 * That has advantages: you can save space by sharing all the SHA1 objects.
 244 * On the other hand, it might just make lookup slower and messier. You
 245 * be the judge.  The default case is to have one DB per managed directory.
 246 */
 247int main(int argc, char **argv)
 248{
 249        const char *git_dir;
 250        const char *sha1_dir;
 251        char *path, *template_dir = NULL;
 252        int len, i;
 253
 254        for (i = 1; i < argc; i++, argv++) {
 255                char *arg = argv[1];
 256                if (arg[0] != '-')
 257                        break;
 258                else if (!strncmp(arg, "--template=", 11))
 259                        template_dir = arg+11;
 260                else
 261                        die(init_db_usage);
 262        }
 263
 264        /*
 265         * Set up the default .git directory contents
 266         */
 267        git_dir = getenv(GIT_DIR_ENVIRONMENT);
 268        if (!git_dir) {
 269                git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 270                fprintf(stderr, "defaulting to local storage area\n");
 271        }
 272        safe_create_dir(git_dir);
 273        create_default_files(git_dir, template_dir);
 274
 275        /*
 276         * And set up the object store.
 277         */
 278        sha1_dir = get_object_directory();
 279        len = strlen(sha1_dir);
 280        path = xmalloc(len + 40);
 281        memcpy(path, sha1_dir, len);
 282
 283        safe_create_dir(sha1_dir);
 284        for (i = 0; i < 256; i++) {
 285                sprintf(path+len, "/%02x", i);
 286                safe_create_dir(path);
 287        }
 288        strcpy(path+len, "/pack");
 289        safe_create_dir(path);
 290        strcpy(path+len, "/info");
 291        safe_create_dir(path);
 292        return 0;
 293}