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