init-db.c

   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
  12 static 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
  22 static 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
  59 static 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
 134 static 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
 164 static 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
 238 static 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  */
 247 int 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         strcpy(path+len, "/pack");
 285         safe_create_dir(path);
 286         strcpy(path+len, "/info");
 287         safe_create_dir(path);
 288         return 0;
 289 }