git/setup.c
Jeff King 1fb2b636c6 set_git_dir: handle feeding gitdir to itself
Ideally we'd free the existing gitdir field before assigning
the new one, to avoid a memory leak. But we can't do so
safely because some callers do the equivalent of:

  set_git_dir(get_git_dir());

We can detect that case as a noop, but there are even more
complicated cases like:

  set_git_dir(remove_leading_path(worktree, get_git_dir());

where we really do need to do some work, but the original
string must remain valid.

Rather than put the burden on callers to make a copy of the
string (only to free it later, since we'll make a copy of it
ourselves), let's solve the problem inside set_git_dir(). We
can make a copy of the pointer for the old gitdir, and then
avoid freeing it until after we've made our new copy.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-06 18:06:26 +09:00

1227 lines
32 KiB
C

#include "cache.h"
#include "repository.h"
#include "config.h"
#include "dir.h"
#include "string-list.h"
static int inside_git_dir = -1;
static int inside_work_tree = -1;
static int work_tree_config_is_bogus;
static struct startup_info the_startup_info;
struct startup_info *startup_info = &the_startup_info;
/*
* The input parameter must contain an absolute path, and it must already be
* normalized.
*
* Find the part of an absolute path that lies inside the work tree by
* dereferencing symlinks outside the work tree, for example:
* /dir1/repo/dir2/file (work tree is /dir1/repo) -> dir2/file
* /dir/file (work tree is /) -> dir/file
* /dir/symlink1/symlink2 (symlink1 points to work tree) -> symlink2
* /dir/repolink/file (repolink points to /dir/repo) -> file
* /dir/repo (exactly equal to work tree) -> (empty string)
*/
static int abspath_part_inside_repo(char *path)
{
size_t len;
size_t wtlen;
char *path0;
int off;
const char *work_tree = get_git_work_tree();
if (!work_tree)
return -1;
wtlen = strlen(work_tree);
len = strlen(path);
off = offset_1st_component(path);
/* check if work tree is already the prefix */
if (wtlen <= len && !strncmp(path, work_tree, wtlen)) {
if (path[wtlen] == '/') {
memmove(path, path + wtlen + 1, len - wtlen);
return 0;
} else if (path[wtlen - 1] == '/' || path[wtlen] == '\0') {
/* work tree is the root, or the whole path */
memmove(path, path + wtlen, len - wtlen + 1);
return 0;
}
/* work tree might match beginning of a symlink to work tree */
off = wtlen;
}
path0 = path;
path += off;
/* check each '/'-terminated level */
while (*path) {
path++;
if (*path == '/') {
*path = '\0';
if (strcmp(real_path(path0), work_tree) == 0) {
memmove(path0, path + 1, len - (path - path0));
return 0;
}
*path = '/';
}
}
/* check whole path */
if (strcmp(real_path(path0), work_tree) == 0) {
*path0 = '\0';
return 0;
}
return -1;
}
/*
* Normalize "path", prepending the "prefix" for relative paths. If
* remaining_prefix is not NULL, return the actual prefix still
* remains in the path. For example, prefix = sub1/sub2/ and path is
*
* foo -> sub1/sub2/foo (full prefix)
* ../foo -> sub1/foo (remaining prefix is sub1/)
* ../../bar -> bar (no remaining prefix)
* ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix)
* `pwd`/../bar -> sub1/bar (no remaining prefix)
*/
char *prefix_path_gently(const char *prefix, int len,
int *remaining_prefix, const char *path)
{
const char *orig = path;
char *sanitized;
if (is_absolute_path(orig)) {
sanitized = xmallocz(strlen(path));
if (remaining_prefix)
*remaining_prefix = 0;
if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
free(sanitized);
return NULL;
}
if (abspath_part_inside_repo(sanitized)) {
free(sanitized);
return NULL;
}
} else {
sanitized = xstrfmt("%.*s%s", len, len ? prefix : "", path);
if (remaining_prefix)
*remaining_prefix = len;
if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
free(sanitized);
return NULL;
}
}
return sanitized;
}
char *prefix_path(const char *prefix, int len, const char *path)
{
char *r = prefix_path_gently(prefix, len, NULL, path);
if (!r)
die("'%s' is outside repository", path);
return r;
}
int path_inside_repo(const char *prefix, const char *path)
{
int len = prefix ? strlen(prefix) : 0;
char *r = prefix_path_gently(prefix, len, NULL, path);
if (r) {
free(r);
return 1;
}
return 0;
}
int check_filename(const char *prefix, const char *arg)
{
char *to_free = NULL;
struct stat st;
if (skip_prefix(arg, ":/", &arg)) {
if (!*arg) /* ":/" is root dir, always exists */
return 1;
prefix = NULL;
} else if (skip_prefix(arg, ":!", &arg) ||
skip_prefix(arg, ":^", &arg)) {
if (!*arg) /* excluding everything is silly, but allowed */
return 1;
}
if (prefix)
arg = to_free = prefix_filename(prefix, arg);
if (!lstat(arg, &st)) {
free(to_free);
return 1; /* file exists */
}
if (is_missing_file_error(errno)) {
free(to_free);
return 0; /* file does not exist */
}
die_errno("failed to stat '%s'", arg);
}
static void NORETURN die_verify_filename(const char *prefix,
const char *arg,
int diagnose_misspelt_rev)
{
if (!diagnose_misspelt_rev)
die(_("%s: no such path in the working tree.\n"
"Use 'git <command> -- <path>...' to specify paths that do not exist locally."),
arg);
/*
* Saying "'(icase)foo' does not exist in the index" when the
* user gave us ":(icase)foo" is just stupid. A magic pathspec
* begins with a colon and is followed by a non-alnum; do not
* let maybe_die_on_misspelt_object_name() even trigger.
*/
if (!(arg[0] == ':' && !isalnum(arg[1])))
maybe_die_on_misspelt_object_name(arg, prefix);
/* ... or fall back the most general message. */
die(_("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
"Use '--' to separate paths from revisions, like this:\n"
"'git <command> [<revision>...] -- [<file>...]'"), arg);
}
/*
* Check for arguments that don't resolve as actual files,
* but which look sufficiently like pathspecs that we'll consider
* them such for the purposes of rev/pathspec DWIM parsing.
*/
static int looks_like_pathspec(const char *arg)
{
/* anything with a wildcard character */
if (!no_wildcard(arg))
return 1;
/* long-form pathspec magic */
if (starts_with(arg, ":("))
return 1;
return 0;
}
/*
* Verify a filename that we got as an argument for a pathspec
* entry. Note that a filename that begins with "-" never verifies
* as true, because even if such a filename were to exist, we want
* it to be preceded by the "--" marker (or we want the user to
* use a format like "./-filename")
*
* The "diagnose_misspelt_rev" is used to provide a user-friendly
* diagnosis when dying upon finding that "name" is not a pathname.
* If set to 1, the diagnosis will try to diagnose "name" as an
* invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
* will only complain about an inexisting file.
*
* This function is typically called to check that a "file or rev"
* argument is unambiguous. In this case, the caller will want
* diagnose_misspelt_rev == 1 when verifying the first non-rev
* argument (which could have been a revision), and
* diagnose_misspelt_rev == 0 for the next ones (because we already
* saw a filename, there's not ambiguity anymore).
*/
void verify_filename(const char *prefix,
const char *arg,
int diagnose_misspelt_rev)
{
if (*arg == '-')
die("bad flag '%s' used after filename", arg);
if (looks_like_pathspec(arg) || check_filename(prefix, arg))
return;
die_verify_filename(prefix, arg, diagnose_misspelt_rev);
}
/*
* Opposite of the above: the command line did not have -- marker
* and we parsed the arg as a refname. It should not be interpretable
* as a filename.
*/
void verify_non_filename(const char *prefix, const char *arg)
{
if (!is_inside_work_tree() || is_inside_git_dir())
return;
if (*arg == '-')
return; /* flag */
if (!check_filename(prefix, arg))
return;
die(_("ambiguous argument '%s': both revision and filename\n"
"Use '--' to separate paths from revisions, like this:\n"
"'git <command> [<revision>...] -- [<file>...]'"), arg);
}
int get_common_dir(struct strbuf *sb, const char *gitdir)
{
const char *git_env_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
if (git_env_common_dir) {
strbuf_addstr(sb, git_env_common_dir);
return 1;
} else {
return get_common_dir_noenv(sb, gitdir);
}
}
int get_common_dir_noenv(struct strbuf *sb, const char *gitdir)
{
struct strbuf data = STRBUF_INIT;
struct strbuf path = STRBUF_INIT;
int ret = 0;
strbuf_addf(&path, "%s/commondir", gitdir);
if (file_exists(path.buf)) {
if (strbuf_read_file(&data, path.buf, 0) <= 0)
die_errno(_("failed to read %s"), path.buf);
while (data.len && (data.buf[data.len - 1] == '\n' ||
data.buf[data.len - 1] == '\r'))
data.len--;
data.buf[data.len] = '\0';
strbuf_reset(&path);
if (!is_absolute_path(data.buf))
strbuf_addf(&path, "%s/", gitdir);
strbuf_addbuf(&path, &data);
strbuf_add_real_path(sb, path.buf);
ret = 1;
} else {
strbuf_addstr(sb, gitdir);
}
strbuf_release(&data);
strbuf_release(&path);
return ret;
}
/*
* Test if it looks like we're at a git directory.
* We want to see:
*
* - either an objects/ directory _or_ the proper
* GIT_OBJECT_DIRECTORY environment variable
* - a refs/ directory
* - either a HEAD symlink or a HEAD file that is formatted as
* a proper "ref:", or a regular file HEAD that has a properly
* formatted sha1 object name.
*/
int is_git_directory(const char *suspect)
{
struct strbuf path = STRBUF_INIT;
int ret = 0;
size_t len;
/* Check worktree-related signatures */
strbuf_addf(&path, "%s/HEAD", suspect);
if (validate_headref(path.buf))
goto done;
strbuf_reset(&path);
get_common_dir(&path, suspect);
len = path.len;
/* Check non-worktree-related signatures */
if (getenv(DB_ENVIRONMENT)) {
if (access(getenv(DB_ENVIRONMENT), X_OK))
goto done;
}
else {
strbuf_setlen(&path, len);
strbuf_addstr(&path, "/objects");
if (access(path.buf, X_OK))
goto done;
}
strbuf_setlen(&path, len);
strbuf_addstr(&path, "/refs");
if (access(path.buf, X_OK))
goto done;
ret = 1;
done:
strbuf_release(&path);
return ret;
}
int is_nonbare_repository_dir(struct strbuf *path)
{
int ret = 0;
int gitfile_error;
size_t orig_path_len = path->len;
assert(orig_path_len != 0);
strbuf_complete(path, '/');
strbuf_addstr(path, ".git");
if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf))
ret = 1;
if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED ||
gitfile_error == READ_GITFILE_ERR_READ_FAILED)
ret = 1;
strbuf_setlen(path, orig_path_len);
return ret;
}
int is_inside_git_dir(void)
{
if (inside_git_dir < 0)
inside_git_dir = is_inside_dir(get_git_dir());
return inside_git_dir;
}
int is_inside_work_tree(void)
{
if (inside_work_tree < 0)
inside_work_tree = is_inside_dir(get_git_work_tree());
return inside_work_tree;
}
void setup_work_tree(void)
{
const char *work_tree, *git_dir;
static int initialized = 0;
if (initialized)
return;
if (work_tree_config_is_bogus)
die("unable to set up work tree using invalid config");
work_tree = get_git_work_tree();
git_dir = get_git_dir();
if (!is_absolute_path(git_dir))
git_dir = real_path(get_git_dir());
if (!work_tree || chdir(work_tree))
die("This operation must be run in a work tree");
/*
* Make sure subsequent git processes find correct worktree
* if $GIT_WORK_TREE is set relative
*/
if (getenv(GIT_WORK_TREE_ENVIRONMENT))
setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
set_git_dir(remove_leading_path(git_dir, work_tree));
initialized = 1;
}
static int check_repo_format(const char *var, const char *value, void *vdata)
{
struct repository_format *data = vdata;
const char *ext;
if (strcmp(var, "core.repositoryformatversion") == 0)
data->version = git_config_int(var, value);
else if (skip_prefix(var, "extensions.", &ext)) {
/*
* record any known extensions here; otherwise,
* we fall through to recording it as unknown, and
* check_repository_format will complain
*/
if (!strcmp(ext, "noop"))
;
else if (!strcmp(ext, "preciousobjects"))
data->precious_objects = git_config_bool(var, value);
else
string_list_append(&data->unknown_extensions, ext);
} else if (strcmp(var, "core.bare") == 0) {
data->is_bare = git_config_bool(var, value);
} else if (strcmp(var, "core.worktree") == 0) {
if (!value)
return config_error_nonbool(var);
data->work_tree = xstrdup(value);
}
return 0;
}
static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
{
struct strbuf sb = STRBUF_INIT;
struct strbuf err = STRBUF_INIT;
struct repository_format candidate;
int has_common;
has_common = get_common_dir(&sb, gitdir);
strbuf_addstr(&sb, "/config");
read_repository_format(&candidate, sb.buf);
strbuf_release(&sb);
/*
* For historical use of check_repository_format() in git-init,
* we treat a missing config as a silent "ok", even when nongit_ok
* is unset.
*/
if (candidate.version < 0)
return 0;
if (verify_repository_format(&candidate, &err) < 0) {
if (nongit_ok) {
warning("%s", err.buf);
strbuf_release(&err);
*nongit_ok = -1;
return -1;
}
die("%s", err.buf);
}
repository_format_precious_objects = candidate.precious_objects;
string_list_clear(&candidate.unknown_extensions, 0);
if (!has_common) {
if (candidate.is_bare != -1) {
is_bare_repository_cfg = candidate.is_bare;
if (is_bare_repository_cfg == 1)
inside_work_tree = -1;
}
if (candidate.work_tree) {
free(git_work_tree_cfg);
git_work_tree_cfg = candidate.work_tree;
inside_work_tree = -1;
}
} else {
free(candidate.work_tree);
}
return 0;
}
int read_repository_format(struct repository_format *format, const char *path)
{
memset(format, 0, sizeof(*format));
format->version = -1;
format->is_bare = -1;
string_list_init(&format->unknown_extensions, 1);
git_config_from_file(check_repo_format, path, format);
return format->version;
}
int verify_repository_format(const struct repository_format *format,
struct strbuf *err)
{
if (GIT_REPO_VERSION_READ < format->version) {
strbuf_addf(err, _("Expected git repo version <= %d, found %d"),
GIT_REPO_VERSION_READ, format->version);
return -1;
}
if (format->version >= 1 && format->unknown_extensions.nr) {
int i;
strbuf_addstr(err, _("unknown repository extensions found:"));
for (i = 0; i < format->unknown_extensions.nr; i++)
strbuf_addf(err, "\n\t%s",
format->unknown_extensions.items[i].string);
return -1;
}
return 0;
}
void read_gitfile_error_die(int error_code, const char *path, const char *dir)
{
switch (error_code) {
case READ_GITFILE_ERR_STAT_FAILED:
case READ_GITFILE_ERR_NOT_A_FILE:
/* non-fatal; follow return path */
break;
case READ_GITFILE_ERR_OPEN_FAILED:
die_errno("Error opening '%s'", path);
case READ_GITFILE_ERR_TOO_LARGE:
die("Too large to be a .git file: '%s'", path);
case READ_GITFILE_ERR_READ_FAILED:
die("Error reading %s", path);
case READ_GITFILE_ERR_INVALID_FORMAT:
die("Invalid gitfile format: %s", path);
case READ_GITFILE_ERR_NO_PATH:
die("No path in gitfile: %s", path);
case READ_GITFILE_ERR_NOT_A_REPO:
die("Not a git repository: %s", dir);
default:
die("BUG: unknown error code");
}
}
/*
* Try to read the location of the git directory from the .git file,
* return path to git directory if found.
*
* On failure, if return_error_code is not NULL, return_error_code
* will be set to an error code and NULL will be returned. If
* return_error_code is NULL the function will die instead (for most
* cases).
*/
const char *read_gitfile_gently(const char *path, int *return_error_code)
{
const int max_file_size = 1 << 20; /* 1MB */
int error_code = 0;
char *buf = NULL;
char *dir = NULL;
const char *slash;
struct stat st;
int fd;
ssize_t len;
if (stat(path, &st)) {
/* NEEDSWORK: discern between ENOENT vs other errors */
error_code = READ_GITFILE_ERR_STAT_FAILED;
goto cleanup_return;
}
if (!S_ISREG(st.st_mode)) {
error_code = READ_GITFILE_ERR_NOT_A_FILE;
goto cleanup_return;
}
if (st.st_size > max_file_size) {
error_code = READ_GITFILE_ERR_TOO_LARGE;
goto cleanup_return;
}
fd = open(path, O_RDONLY);
if (fd < 0) {
error_code = READ_GITFILE_ERR_OPEN_FAILED;
goto cleanup_return;
}
buf = xmallocz(st.st_size);
len = read_in_full(fd, buf, st.st_size);
close(fd);
if (len != st.st_size) {
error_code = READ_GITFILE_ERR_READ_FAILED;
goto cleanup_return;
}
if (!starts_with(buf, "gitdir: ")) {
error_code = READ_GITFILE_ERR_INVALID_FORMAT;
goto cleanup_return;
}
while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
len--;
if (len < 9) {
error_code = READ_GITFILE_ERR_NO_PATH;
goto cleanup_return;
}
buf[len] = '\0';
dir = buf + 8;
if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
size_t pathlen = slash+1 - path;
dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
(int)(len - 8), buf + 8);
free(buf);
buf = dir;
}
if (!is_git_directory(dir)) {
error_code = READ_GITFILE_ERR_NOT_A_REPO;
goto cleanup_return;
}
path = real_path(dir);
cleanup_return:
if (return_error_code)
*return_error_code = error_code;
else if (error_code)
read_gitfile_error_die(error_code, path, dir);
free(buf);
return error_code ? NULL : path;
}
static const char *setup_explicit_git_dir(const char *gitdirenv,
struct strbuf *cwd,
int *nongit_ok)
{
const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
const char *worktree;
char *gitfile;
int offset;
if (PATH_MAX - 40 < strlen(gitdirenv))
die("'$%s' too big", GIT_DIR_ENVIRONMENT);
gitfile = (char*)read_gitfile(gitdirenv);
if (gitfile) {
gitfile = xstrdup(gitfile);
gitdirenv = gitfile;
}
if (!is_git_directory(gitdirenv)) {
if (nongit_ok) {
*nongit_ok = 1;
free(gitfile);
return NULL;
}
die("Not a git repository: '%s'", gitdirenv);
}
if (check_repository_format_gently(gitdirenv, nongit_ok)) {
free(gitfile);
return NULL;
}
/* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
if (work_tree_env)
set_git_work_tree(work_tree_env);
else if (is_bare_repository_cfg > 0) {
if (git_work_tree_cfg) {
/* #22.2, #30 */
warning("core.bare and core.worktree do not make sense");
work_tree_config_is_bogus = 1;
}
/* #18, #26 */
set_git_dir(gitdirenv);
free(gitfile);
return NULL;
}
else if (git_work_tree_cfg) { /* #6, #14 */
if (is_absolute_path(git_work_tree_cfg))
set_git_work_tree(git_work_tree_cfg);
else {
char *core_worktree;
if (chdir(gitdirenv))
die_errno("Could not chdir to '%s'", gitdirenv);
if (chdir(git_work_tree_cfg))
die_errno("Could not chdir to '%s'", git_work_tree_cfg);
core_worktree = xgetcwd();
if (chdir(cwd->buf))
die_errno("Could not come back to cwd");
set_git_work_tree(core_worktree);
free(core_worktree);
}
}
else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
/* #16d */
set_git_dir(gitdirenv);
free(gitfile);
return NULL;
}
else /* #2, #10 */
set_git_work_tree(".");
/* set_git_work_tree() must have been called by now */
worktree = get_git_work_tree();
/* both get_git_work_tree() and cwd are already normalized */
if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
set_git_dir(gitdirenv);
free(gitfile);
return NULL;
}
offset = dir_inside_of(cwd->buf, worktree);
if (offset >= 0) { /* cwd inside worktree? */
set_git_dir(real_path(gitdirenv));
if (chdir(worktree))
die_errno("Could not chdir to '%s'", worktree);
strbuf_addch(cwd, '/');
free(gitfile);
return cwd->buf + offset;
}
/* cwd outside worktree */
set_git_dir(gitdirenv);
free(gitfile);
return NULL;
}
static const char *setup_discovered_git_dir(const char *gitdir,
struct strbuf *cwd, int offset,
int *nongit_ok)
{
if (check_repository_format_gently(gitdir, nongit_ok))
return NULL;
/* --work-tree is set without --git-dir; use discovered one */
if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
char *to_free = NULL;
const char *ret;
if (offset != cwd->len && !is_absolute_path(gitdir))
gitdir = to_free = real_pathdup(gitdir, 1);
if (chdir(cwd->buf))
die_errno("Could not come back to cwd");
ret = setup_explicit_git_dir(gitdir, cwd, nongit_ok);
free(to_free);
return ret;
}
/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
if (is_bare_repository_cfg > 0) {
set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
if (chdir(cwd->buf))
die_errno("Could not come back to cwd");
return NULL;
}
/* #0, #1, #5, #8, #9, #12, #13 */
set_git_work_tree(".");
if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
set_git_dir(gitdir);
inside_git_dir = 0;
inside_work_tree = 1;
if (offset == cwd->len)
return NULL;
/* Make "offset" point past the '/' (already the case for root dirs) */
if (offset != offset_1st_component(cwd->buf))
offset++;
/* Add a '/' at the end */
strbuf_addch(cwd, '/');
return cwd->buf + offset;
}
/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
int *nongit_ok)
{
int root_len;
if (check_repository_format_gently(".", nongit_ok))
return NULL;
setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
/* --work-tree is set without --git-dir; use discovered one */
if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
static const char *gitdir;
gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
if (chdir(cwd->buf))
die_errno("Could not come back to cwd");
return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
}
inside_git_dir = 1;
inside_work_tree = 0;
if (offset != cwd->len) {
if (chdir(cwd->buf))
die_errno("Cannot come back to cwd");
root_len = offset_1st_component(cwd->buf);
strbuf_setlen(cwd, offset > root_len ? offset : root_len);
set_git_dir(cwd->buf);
}
else
set_git_dir(".");
return NULL;
}
static const char *setup_nongit(const char *cwd, int *nongit_ok)
{
if (!nongit_ok)
die(_("Not a git repository (or any of the parent directories): %s"), DEFAULT_GIT_DIR_ENVIRONMENT);
if (chdir(cwd))
die_errno(_("Cannot come back to cwd"));
*nongit_ok = 1;
return NULL;
}
static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
{
struct stat buf;
if (stat(path, &buf)) {
die_errno("failed to stat '%*s%s%s'",
prefix_len,
prefix ? prefix : "",
prefix ? "/" : "", path);
}
return buf.st_dev;
}
/*
* A "string_list_each_func_t" function that canonicalizes an entry
* from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
* discards it if unusable. The presence of an empty entry in
* GIT_CEILING_DIRECTORIES turns off canonicalization for all
* subsequent entries.
*/
static int canonicalize_ceiling_entry(struct string_list_item *item,
void *cb_data)
{
int *empty_entry_found = cb_data;
char *ceil = item->string;
if (!*ceil) {
*empty_entry_found = 1;
return 0;
} else if (!is_absolute_path(ceil)) {
return 0;
} else if (*empty_entry_found) {
/* Keep entry but do not canonicalize it */
return 1;
} else {
char *real_path = real_pathdup(ceil, 0);
if (!real_path) {
return 0;
}
free(item->string);
item->string = real_path;
return 1;
}
}
enum discovery_result {
GIT_DIR_NONE = 0,
GIT_DIR_EXPLICIT,
GIT_DIR_DISCOVERED,
GIT_DIR_BARE,
/* these are errors */
GIT_DIR_HIT_CEILING = -1,
GIT_DIR_HIT_MOUNT_POINT = -2,
GIT_DIR_INVALID_GITFILE = -3
};
/*
* We cannot decide in this function whether we are in the work tree or
* not, since the config can only be read _after_ this function was called.
*
* Also, we avoid changing any global state (such as the current working
* directory) to allow early callers.
*
* The directory where the search should start needs to be passed in via the
* `dir` parameter; upon return, the `dir` buffer will contain the path of
* the directory where the search ended, and `gitdir` will contain the path of
* the discovered .git/ directory, if any. If `gitdir` is not absolute, it
* is relative to `dir` (i.e. *not* necessarily the cwd).
*/
static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir,
struct strbuf *gitdir,
int die_on_error)
{
const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
const char *gitdirenv;
int ceil_offset = -1, min_offset = has_dos_drive_prefix(dir->buf) ? 3 : 1;
dev_t current_device = 0;
int one_filesystem = 1;
/*
* If GIT_DIR is set explicitly, we're not going
* to do any discovery, but we still do repository
* validation.
*/
gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
if (gitdirenv) {
strbuf_addstr(gitdir, gitdirenv);
return GIT_DIR_EXPLICIT;
}
if (env_ceiling_dirs) {
int empty_entry_found = 0;
string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
filter_string_list(&ceiling_dirs, 0,
canonicalize_ceiling_entry, &empty_entry_found);
ceil_offset = longest_ancestor_length(dir->buf, &ceiling_dirs);
string_list_clear(&ceiling_dirs, 0);
}
if (ceil_offset < 0)
ceil_offset = min_offset - 2;
/*
* Test in the following order (relative to the dir):
* - .git (file containing "gitdir: <path>")
* - .git/
* - ./ (bare)
* - ../.git
* - ../.git/
* - ../ (bare)
* - ../../.git/
* etc.
*/
one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
if (one_filesystem)
current_device = get_device_or_die(dir->buf, NULL, 0);
for (;;) {
int offset = dir->len, error_code = 0;
if (offset > min_offset)
strbuf_addch(dir, '/');
strbuf_addstr(dir, DEFAULT_GIT_DIR_ENVIRONMENT);
gitdirenv = read_gitfile_gently(dir->buf, die_on_error ?
NULL : &error_code);
if (!gitdirenv) {
if (die_on_error ||
error_code == READ_GITFILE_ERR_NOT_A_FILE) {
/* NEEDSWORK: fail if .git is not file nor dir */
if (is_git_directory(dir->buf))
gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
} else if (error_code != READ_GITFILE_ERR_STAT_FAILED)
return GIT_DIR_INVALID_GITFILE;
}
strbuf_setlen(dir, offset);
if (gitdirenv) {
strbuf_addstr(gitdir, gitdirenv);
return GIT_DIR_DISCOVERED;
}
if (is_git_directory(dir->buf)) {
strbuf_addstr(gitdir, ".");
return GIT_DIR_BARE;
}
if (offset <= min_offset)
return GIT_DIR_HIT_CEILING;
while (--offset > ceil_offset && !is_dir_sep(dir->buf[offset]))
; /* continue */
if (offset <= ceil_offset)
return GIT_DIR_HIT_CEILING;
strbuf_setlen(dir, offset > min_offset ? offset : min_offset);
if (one_filesystem &&
current_device != get_device_or_die(dir->buf, NULL, offset))
return GIT_DIR_HIT_MOUNT_POINT;
}
}
int discover_git_directory(struct strbuf *commondir,
struct strbuf *gitdir)
{
struct strbuf dir = STRBUF_INIT, err = STRBUF_INIT;
size_t gitdir_offset = gitdir->len, cwd_len;
size_t commondir_offset = commondir->len;
struct repository_format candidate;
if (strbuf_getcwd(&dir))
return -1;
cwd_len = dir.len;
if (setup_git_directory_gently_1(&dir, gitdir, 0) <= 0) {
strbuf_release(&dir);
return -1;
}
/*
* The returned gitdir is relative to dir, and if dir does not reflect
* the current working directory, we simply make the gitdir absolute.
*/
if (dir.len < cwd_len && !is_absolute_path(gitdir->buf + gitdir_offset)) {
/* Avoid a trailing "/." */
if (!strcmp(".", gitdir->buf + gitdir_offset))
strbuf_setlen(gitdir, gitdir_offset);
else
strbuf_addch(&dir, '/');
strbuf_insert(gitdir, gitdir_offset, dir.buf, dir.len);
}
get_common_dir(commondir, gitdir->buf + gitdir_offset);
strbuf_reset(&dir);
strbuf_addf(&dir, "%s/config", commondir->buf + commondir_offset);
read_repository_format(&candidate, dir.buf);
strbuf_release(&dir);
if (verify_repository_format(&candidate, &err) < 0) {
warning("ignoring git dir '%s': %s",
gitdir->buf + gitdir_offset, err.buf);
strbuf_release(&err);
strbuf_setlen(commondir, commondir_offset);
strbuf_setlen(gitdir, gitdir_offset);
return -1;
}
return 0;
}
const char *setup_git_directory_gently(int *nongit_ok)
{
static struct strbuf cwd = STRBUF_INIT;
struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT;
const char *prefix;
/*
* We may have read an incomplete configuration before
* setting-up the git directory. If so, clear the cache so
* that the next queries to the configuration reload complete
* configuration (including the per-repo config file that we
* ignored previously).
*/
git_config_clear();
/*
* Let's assume that we are in a git repository.
* If it turns out later that we are somewhere else, the value will be
* updated accordingly.
*/
if (nongit_ok)
*nongit_ok = 0;
if (strbuf_getcwd(&cwd))
die_errno(_("Unable to read current working directory"));
strbuf_addbuf(&dir, &cwd);
switch (setup_git_directory_gently_1(&dir, &gitdir, 1)) {
case GIT_DIR_NONE:
prefix = NULL;
break;
case GIT_DIR_EXPLICIT:
prefix = setup_explicit_git_dir(gitdir.buf, &cwd, nongit_ok);
break;
case GIT_DIR_DISCOVERED:
if (dir.len < cwd.len && chdir(dir.buf))
die(_("Cannot change to '%s'"), dir.buf);
prefix = setup_discovered_git_dir(gitdir.buf, &cwd, dir.len,
nongit_ok);
break;
case GIT_DIR_BARE:
if (dir.len < cwd.len && chdir(dir.buf))
die(_("Cannot change to '%s'"), dir.buf);
prefix = setup_bare_git_dir(&cwd, dir.len, nongit_ok);
break;
case GIT_DIR_HIT_CEILING:
prefix = setup_nongit(cwd.buf, nongit_ok);
break;
case GIT_DIR_HIT_MOUNT_POINT:
if (nongit_ok) {
*nongit_ok = 1;
strbuf_release(&cwd);
strbuf_release(&dir);
return NULL;
}
die(_("Not a git repository (or any parent up to mount point %s)\n"
"Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
dir.buf);
default:
die("BUG: unhandled setup_git_directory_1() result");
}
if (prefix)
setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
else
setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
startup_info->have_repository = !nongit_ok || !*nongit_ok;
startup_info->prefix = prefix;
/*
* Not all paths through the setup code will call 'set_git_dir()' (which
* directly sets up the environment) so in order to guarantee that the
* environment is in a consistent state after setup, explicitly setup
* the environment if we have a repository.
*
* NEEDSWORK: currently we allow bogus GIT_DIR values to be set in some
* code paths so we also need to explicitly setup the environment if
* the user has set GIT_DIR. It may be beneficial to disallow bogus
* GIT_DIR values at some point in the future.
*/
if (startup_info->have_repository || getenv(GIT_DIR_ENVIRONMENT)) {
if (!the_repository->gitdir) {
const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
if (!gitdir)
gitdir = DEFAULT_GIT_DIR_ENVIRONMENT;
repo_set_gitdir(the_repository, gitdir);
setup_git_env();
}
}
strbuf_release(&dir);
strbuf_release(&gitdir);
return prefix;
}
int git_config_perm(const char *var, const char *value)
{
int i;
char *endptr;
if (value == NULL)
return PERM_GROUP;
if (!strcmp(value, "umask"))
return PERM_UMASK;
if (!strcmp(value, "group"))
return PERM_GROUP;
if (!strcmp(value, "all") ||
!strcmp(value, "world") ||
!strcmp(value, "everybody"))
return PERM_EVERYBODY;
/* Parse octal numbers */
i = strtol(value, &endptr, 8);
/* If not an octal number, maybe true/false? */
if (*endptr != 0)
return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
/*
* Treat values 0, 1 and 2 as compatibility cases, otherwise it is
* a chmod value to restrict to.
*/
switch (i) {
case PERM_UMASK: /* 0 */
return PERM_UMASK;
case OLD_PERM_GROUP: /* 1 */
return PERM_GROUP;
case OLD_PERM_EVERYBODY: /* 2 */
return PERM_EVERYBODY;
}
/* A filemode value was given: 0xxx */
if ((i & 0600) != 0600)
die(_("Problem with core.sharedRepository filemode value "
"(0%.3o).\nThe owner of files must always have "
"read and write permissions."), i);
/*
* Mask filemode value. Others can not get write permission.
* x flags for directories are handled separately.
*/
return -(i & 0666);
}
void check_repository_format(void)
{
check_repository_format_gently(get_git_dir(), NULL);
startup_info->have_repository = 1;
}
/*
* Returns the "prefix", a path to the current working directory
* relative to the work tree root, or NULL, if the current working
* directory is not a strict subdirectory of the work tree root. The
* prefix always ends with a '/' character.
*/
const char *setup_git_directory(void)
{
return setup_git_directory_gently(NULL);
}
const char *resolve_gitdir_gently(const char *suspect, int *return_error_code)
{
if (is_git_directory(suspect))
return suspect;
return read_gitfile_gently(suspect, return_error_code);
}
/* if any standard file descriptor is missing open it to /dev/null */
void sanitize_stdfds(void)
{
int fd = open("/dev/null", O_RDWR, 0);
while (fd != -1 && fd < 2)
fd = dup(fd);
if (fd == -1)
die_errno("open /dev/null or dup failed");
if (fd > 2)
close(fd);
}
int daemonize(void)
{
#ifdef NO_POSIX_GOODIES
errno = ENOSYS;
return -1;
#else
switch (fork()) {
case 0:
break;
case -1:
die_errno("fork failed");
default:
exit(0);
}
if (setsid() == -1)
die_errno("setsid failed");
close(0);
close(1);
close(2);
sanitize_stdfds();
return 0;
#endif
}