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git/builtin/init-db.c
Jeff King 5096d4909f convert trivial sprintf / strcpy calls to xsnprintf
We sometimes sprintf into fixed-size buffers when we know
that the buffer is large enough to fit the input (either
because it's a constant, or because it's numeric input that
is bounded in size). Likewise with strcpy of constant
strings.

However, these sites make it hard to audit sprintf and
strcpy calls for buffer overflows, as a reader has to
cross-reference the size of the array with the input. Let's
use xsnprintf instead, which communicates to a reader that
we don't expect this to overflow (and catches the mistake in
case we do).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-25 10:18:18 -07:00

611 lines
16 KiB
C

/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
#include "refs.h"
#include "builtin.h"
#include "exec_cmd.h"
#include "parse-options.h"
#ifndef DEFAULT_GIT_TEMPLATE_DIR
#define DEFAULT_GIT_TEMPLATE_DIR "/usr/share/git-core/templates"
#endif
#ifdef NO_TRUSTABLE_FILEMODE
#define TEST_FILEMODE 0
#else
#define TEST_FILEMODE 1
#endif
static int init_is_bare_repository = 0;
static int init_shared_repository = -1;
static const char *init_db_template_dir;
static const char *git_link;
static void safe_create_dir(const char *dir, int share)
{
if (mkdir(dir, 0777) < 0) {
if (errno != EEXIST) {
perror(dir);
exit(1);
}
}
else if (share && adjust_shared_perm(dir))
die(_("Could not make %s writable by group"), dir);
}
static void copy_templates_1(char *path, int baselen,
char *template, int template_baselen,
DIR *dir)
{
struct dirent *de;
/* Note: if ".git/hooks" file exists in the repository being
* re-initialized, /etc/core-git/templates/hooks/update would
* cause "git init" to fail here. I think this is sane but
* it means that the set of templates we ship by default, along
* with the way the namespace under .git/ is organized, should
* be really carefully chosen.
*/
safe_create_dir(path, 1);
while ((de = readdir(dir)) != NULL) {
struct stat st_git, st_template;
int namelen;
int exists = 0;
if (de->d_name[0] == '.')
continue;
namelen = strlen(de->d_name);
if ((PATH_MAX <= baselen + namelen) ||
(PATH_MAX <= template_baselen + namelen))
die(_("insanely long template name %s"), de->d_name);
memcpy(path + baselen, de->d_name, namelen+1);
memcpy(template + template_baselen, de->d_name, namelen+1);
if (lstat(path, &st_git)) {
if (errno != ENOENT)
die_errno(_("cannot stat '%s'"), path);
}
else
exists = 1;
if (lstat(template, &st_template))
die_errno(_("cannot stat template '%s'"), template);
if (S_ISDIR(st_template.st_mode)) {
DIR *subdir = opendir(template);
int baselen_sub = baselen + namelen;
int template_baselen_sub = template_baselen + namelen;
if (!subdir)
die_errno(_("cannot opendir '%s'"), template);
path[baselen_sub++] =
template[template_baselen_sub++] = '/';
path[baselen_sub] =
template[template_baselen_sub] = 0;
copy_templates_1(path, baselen_sub,
template, template_baselen_sub,
subdir);
closedir(subdir);
}
else if (exists)
continue;
else if (S_ISLNK(st_template.st_mode)) {
char lnk[256];
int len;
len = readlink(template, lnk, sizeof(lnk));
if (len < 0)
die_errno(_("cannot readlink '%s'"), template);
if (sizeof(lnk) <= len)
die(_("insanely long symlink %s"), template);
lnk[len] = 0;
if (symlink(lnk, path))
die_errno(_("cannot symlink '%s' '%s'"), lnk, path);
}
else if (S_ISREG(st_template.st_mode)) {
if (copy_file(path, template, st_template.st_mode))
die_errno(_("cannot copy '%s' to '%s'"), template,
path);
}
else
error(_("ignoring template %s"), template);
}
}
static void copy_templates(const char *template_dir)
{
char path[PATH_MAX];
char template_path[PATH_MAX];
int template_len;
DIR *dir;
const char *git_dir = get_git_dir();
int len = strlen(git_dir);
char *to_free = NULL;
if (!template_dir)
template_dir = getenv(TEMPLATE_DIR_ENVIRONMENT);
if (!template_dir)
template_dir = init_db_template_dir;
if (!template_dir)
template_dir = to_free = system_path(DEFAULT_GIT_TEMPLATE_DIR);
if (!template_dir[0]) {
free(to_free);
return;
}
template_len = strlen(template_dir);
if (PATH_MAX <= (template_len+strlen("/config")))
die(_("insanely long template path %s"), template_dir);
strcpy(template_path, template_dir);
if (template_path[template_len-1] != '/') {
template_path[template_len++] = '/';
template_path[template_len] = 0;
}
dir = opendir(template_path);
if (!dir) {
warning(_("templates not found %s"), template_dir);
goto free_return;
}
/* Make sure that template is from the correct vintage */
strcpy(template_path + template_len, "config");
repository_format_version = 0;
git_config_from_file(check_repository_format_version,
template_path, NULL);
template_path[template_len] = 0;
if (repository_format_version &&
repository_format_version != GIT_REPO_VERSION) {
warning(_("not copying templates of "
"a wrong format version %d from '%s'"),
repository_format_version,
template_dir);
goto close_free_return;
}
memcpy(path, git_dir, len);
if (len && path[len - 1] != '/')
path[len++] = '/';
path[len] = 0;
copy_templates_1(path, len,
template_path, template_len,
dir);
close_free_return:
closedir(dir);
free_return:
free(to_free);
}
static int git_init_db_config(const char *k, const char *v, void *cb)
{
if (!strcmp(k, "init.templatedir"))
return git_config_pathname(&init_db_template_dir, k, v);
return 0;
}
/*
* If the git_dir is not directly inside the working tree, then git will not
* find it by default, and we need to set the worktree explicitly.
*/
static int needs_work_tree_config(const char *git_dir, const char *work_tree)
{
if (!strcmp(work_tree, "/") && !strcmp(git_dir, "/.git"))
return 0;
if (skip_prefix(git_dir, work_tree, &git_dir) &&
!strcmp(git_dir, "/.git"))
return 0;
return 1;
}
static int create_default_files(const char *template_path)
{
const char *git_dir = get_git_dir();
unsigned len = strlen(git_dir);
static char path[PATH_MAX];
struct stat st1;
char repo_version_string[10];
char junk[2];
int reinit;
int filemode;
if (len > sizeof(path)-50)
die(_("insane git directory %s"), git_dir);
memcpy(path, git_dir, len);
if (len && path[len-1] != '/')
path[len++] = '/';
/*
* Create .git/refs/{heads,tags}
*/
safe_create_dir(git_path("refs"), 1);
safe_create_dir(git_path("refs/heads"), 1);
safe_create_dir(git_path("refs/tags"), 1);
/* Just look for `init.templatedir` */
git_config(git_init_db_config, NULL);
/* First copy the templates -- we might have the default
* config file there, in which case we would want to read
* from it after installing.
*/
copy_templates(template_path);
git_config(git_default_config, NULL);
is_bare_repository_cfg = init_is_bare_repository;
/* reading existing config may have overwrote it */
if (init_shared_repository != -1)
shared_repository = init_shared_repository;
/*
* We would have created the above under user's umask -- under
* shared-repository settings, we would need to fix them up.
*/
if (shared_repository) {
adjust_shared_perm(get_git_dir());
adjust_shared_perm(git_path("refs"));
adjust_shared_perm(git_path("refs/heads"));
adjust_shared_perm(git_path("refs/tags"));
}
/*
* Create the default symlink from ".git/HEAD" to the "master"
* branch, if it does not exist yet.
*/
strcpy(path + len, "HEAD");
reinit = (!access(path, R_OK)
|| readlink(path, junk, sizeof(junk)-1) != -1);
if (!reinit) {
if (create_symref("HEAD", "refs/heads/master", NULL) < 0)
exit(1);
}
/* This forces creation of new config file */
xsnprintf(repo_version_string, sizeof(repo_version_string),
"%d", GIT_REPO_VERSION);
git_config_set("core.repositoryformatversion", repo_version_string);
path[len] = 0;
strcpy(path + len, "config");
/* Check filemode trustability */
filemode = TEST_FILEMODE;
if (TEST_FILEMODE && !lstat(path, &st1)) {
struct stat st2;
filemode = (!chmod(path, st1.st_mode ^ S_IXUSR) &&
!lstat(path, &st2) &&
st1.st_mode != st2.st_mode &&
!chmod(path, st1.st_mode));
if (filemode && !reinit && (st1.st_mode & S_IXUSR))
filemode = 0;
}
git_config_set("core.filemode", filemode ? "true" : "false");
if (is_bare_repository())
git_config_set("core.bare", "true");
else {
const char *work_tree = get_git_work_tree();
git_config_set("core.bare", "false");
/* allow template config file to override the default */
if (log_all_ref_updates == -1)
git_config_set("core.logallrefupdates", "true");
if (needs_work_tree_config(git_dir, work_tree))
git_config_set("core.worktree", work_tree);
}
if (!reinit) {
/* Check if symlink is supported in the work tree */
path[len] = 0;
strcpy(path + len, "tXXXXXX");
if (!close(xmkstemp(path)) &&
!unlink(path) &&
!symlink("testing", path) &&
!lstat(path, &st1) &&
S_ISLNK(st1.st_mode))
unlink(path); /* good */
else
git_config_set("core.symlinks", "false");
/* Check if the filesystem is case-insensitive */
path[len] = 0;
strcpy(path + len, "CoNfIg");
if (!access(path, F_OK))
git_config_set("core.ignorecase", "true");
probe_utf8_pathname_composition(path, len);
}
return reinit;
}
static void create_object_directory(void)
{
const char *object_directory = get_object_directory();
int len = strlen(object_directory);
char *path = xmalloc(len + 40);
memcpy(path, object_directory, len);
safe_create_dir(object_directory, 1);
strcpy(path+len, "/pack");
safe_create_dir(path, 1);
strcpy(path+len, "/info");
safe_create_dir(path, 1);
free(path);
}
int set_git_dir_init(const char *git_dir, const char *real_git_dir,
int exist_ok)
{
if (real_git_dir) {
struct stat st;
if (!exist_ok && !stat(git_dir, &st))
die(_("%s already exists"), git_dir);
if (!exist_ok && !stat(real_git_dir, &st))
die(_("%s already exists"), real_git_dir);
/*
* make sure symlinks are resolved because we'll be
* moving the target repo later on in separate_git_dir()
*/
git_link = xstrdup(real_path(git_dir));
set_git_dir(real_path(real_git_dir));
}
else {
set_git_dir(real_path(git_dir));
git_link = NULL;
}
return 0;
}
static void separate_git_dir(const char *git_dir)
{
struct stat st;
if (!stat(git_link, &st)) {
const char *src;
if (S_ISREG(st.st_mode))
src = read_gitfile(git_link);
else if (S_ISDIR(st.st_mode))
src = git_link;
else
die(_("unable to handle file type %d"), (int)st.st_mode);
if (rename(src, git_dir))
die_errno(_("unable to move %s to %s"), src, git_dir);
}
write_file(git_link, "gitdir: %s", git_dir);
}
int init_db(const char *template_dir, unsigned int flags)
{
int reinit;
const char *git_dir = get_git_dir();
if (git_link)
separate_git_dir(git_dir);
safe_create_dir(git_dir, 0);
init_is_bare_repository = is_bare_repository();
/* Check to see if the repository version is right.
* Note that a newly created repository does not have
* config file, so this will not fail. What we are catching
* is an attempt to reinitialize new repository with an old tool.
*/
check_repository_format();
reinit = create_default_files(template_dir);
create_object_directory();
if (shared_repository) {
char buf[10];
/* We do not spell "group" and such, so that
* the configuration can be read by older version
* of git. Note, we use octal numbers for new share modes,
* and compatibility values for PERM_GROUP and
* PERM_EVERYBODY.
*/
if (shared_repository < 0)
/* force to the mode value */
xsnprintf(buf, sizeof(buf), "0%o", -shared_repository);
else if (shared_repository == PERM_GROUP)
xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_GROUP);
else if (shared_repository == PERM_EVERYBODY)
xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_EVERYBODY);
else
die("BUG: invalid value for shared_repository");
git_config_set("core.sharedrepository", buf);
git_config_set("receive.denyNonFastforwards", "true");
}
if (!(flags & INIT_DB_QUIET)) {
int len = strlen(git_dir);
/* TRANSLATORS: The first '%s' is either "Reinitialized
existing" or "Initialized empty", the second " shared" or
"", and the last '%s%s' is the verbatim directory name. */
printf(_("%s%s Git repository in %s%s\n"),
reinit ? _("Reinitialized existing") : _("Initialized empty"),
shared_repository ? _(" shared") : "",
git_dir, len && git_dir[len-1] != '/' ? "/" : "");
}
return 0;
}
static int guess_repository_type(const char *git_dir)
{
const char *slash;
char *cwd;
int cwd_is_git_dir;
/*
* "GIT_DIR=. git init" is always bare.
* "GIT_DIR=`pwd` git init" too.
*/
if (!strcmp(".", git_dir))
return 1;
cwd = xgetcwd();
cwd_is_git_dir = !strcmp(git_dir, cwd);
free(cwd);
if (cwd_is_git_dir)
return 1;
/*
* "GIT_DIR=.git or GIT_DIR=something/.git is usually not.
*/
if (!strcmp(git_dir, ".git"))
return 0;
slash = strrchr(git_dir, '/');
if (slash && !strcmp(slash, "/.git"))
return 0;
/*
* Otherwise it is often bare. At this point
* we are just guessing.
*/
return 1;
}
static int shared_callback(const struct option *opt, const char *arg, int unset)
{
*((int *) opt->value) = (arg) ? git_config_perm("arg", arg) : PERM_GROUP;
return 0;
}
static const char *const init_db_usage[] = {
N_("git init [-q | --quiet] [--bare] [--template=<template-directory>] [--shared[=<permissions>]] [<directory>]"),
NULL
};
/*
* If you want to, you can share the DB area with any number of branches.
* That has advantages: you can save space by sharing all the SHA1 objects.
* On the other hand, it might just make lookup slower and messier. You
* be the judge. The default case is to have one DB per managed directory.
*/
int cmd_init_db(int argc, const char **argv, const char *prefix)
{
const char *git_dir;
const char *real_git_dir = NULL;
const char *work_tree;
const char *template_dir = NULL;
unsigned int flags = 0;
const struct option init_db_options[] = {
OPT_STRING(0, "template", &template_dir, N_("template-directory"),
N_("directory from which templates will be used")),
OPT_SET_INT(0, "bare", &is_bare_repository_cfg,
N_("create a bare repository"), 1),
{ OPTION_CALLBACK, 0, "shared", &init_shared_repository,
N_("permissions"),
N_("specify that the git repository is to be shared amongst several users"),
PARSE_OPT_OPTARG | PARSE_OPT_NONEG, shared_callback, 0},
OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET),
OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
N_("separate git dir from working tree")),
OPT_END()
};
argc = parse_options(argc, argv, prefix, init_db_options, init_db_usage, 0);
if (real_git_dir && !is_absolute_path(real_git_dir))
real_git_dir = xstrdup(real_path(real_git_dir));
if (argc == 1) {
int mkdir_tried = 0;
retry:
if (chdir(argv[0]) < 0) {
if (!mkdir_tried) {
int saved;
/*
* At this point we haven't read any configuration,
* and we know shared_repository should always be 0;
* but just in case we play safe.
*/
saved = shared_repository;
shared_repository = 0;
switch (safe_create_leading_directories_const(argv[0])) {
case SCLD_OK:
case SCLD_PERMS:
break;
case SCLD_EXISTS:
errno = EEXIST;
/* fallthru */
default:
die_errno(_("cannot mkdir %s"), argv[0]);
break;
}
shared_repository = saved;
if (mkdir(argv[0], 0777) < 0)
die_errno(_("cannot mkdir %s"), argv[0]);
mkdir_tried = 1;
goto retry;
}
die_errno(_("cannot chdir to %s"), argv[0]);
}
} else if (0 < argc) {
usage(init_db_usage[0]);
}
if (is_bare_repository_cfg == 1) {
char *cwd = xgetcwd();
setenv(GIT_DIR_ENVIRONMENT, cwd, argc > 0);
free(cwd);
}
if (init_shared_repository != -1)
shared_repository = init_shared_repository;
/*
* GIT_WORK_TREE makes sense only in conjunction with GIT_DIR
* without --bare. Catch the error early.
*/
git_dir = getenv(GIT_DIR_ENVIRONMENT);
work_tree = getenv(GIT_WORK_TREE_ENVIRONMENT);
if ((!git_dir || is_bare_repository_cfg == 1) && work_tree)
die(_("%s (or --work-tree=<directory>) not allowed without "
"specifying %s (or --git-dir=<directory>)"),
GIT_WORK_TREE_ENVIRONMENT,
GIT_DIR_ENVIRONMENT);
/*
* Set up the default .git directory contents
*/
if (!git_dir)
git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
if (is_bare_repository_cfg < 0)
is_bare_repository_cfg = guess_repository_type(git_dir);
if (!is_bare_repository_cfg) {
const char *git_dir_parent = strrchr(git_dir, '/');
if (git_dir_parent) {
char *rel = xstrndup(git_dir, git_dir_parent - git_dir);
git_work_tree_cfg = xstrdup(real_path(rel));
free(rel);
}
if (!git_work_tree_cfg)
git_work_tree_cfg = xgetcwd();
if (work_tree)
set_git_work_tree(work_tree);
else
set_git_work_tree(git_work_tree_cfg);
if (access(get_git_work_tree(), X_OK))
die_errno (_("Cannot access work tree '%s'"),
get_git_work_tree());
}
else {
if (work_tree)
set_git_work_tree(work_tree);
}
set_git_dir_init(git_dir, real_git_dir, 1);
return init_db(template_dir, flags);
}