git/environment.c
Patrick Steinhardt d8d77153ea config: allow specifying config entries via envvar pairs
While we currently have the `GIT_CONFIG_PARAMETERS` environment variable
which can be used to pass runtime configuration data to git processes,
it's an internal implementation detail and not supposed to be used by
end users.

Next to being for internal use only, this way of passing config entries
has a major downside: the config keys need to be parsed as they contain
both key and value in a single variable. As such, it is left to the user
to escape any potentially harmful characters in the value, which is
quite hard to do if values are controlled by a third party.

This commit thus adds a new way of adding config entries via the
environment which gets rid of this shortcoming. If the user passes the
`GIT_CONFIG_COUNT=$n` environment variable, Git will parse environment
variable pairs `GIT_CONFIG_KEY_$i` and `GIT_CONFIG_VALUE_$i` for each
`i` in `[0,n)`.

While the same can be achieved with `git -c <name>=<value>`, one may
wish to not do so for potentially sensitive information. E.g. if one
wants to set `http.extraHeader` to contain an authentication token,
doing so via `-c` would trivially leak those credentials via e.g. ps(1),
which typically also shows command arguments.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-15 13:03:45 -08:00

424 lines
11 KiB
C

/*
* We put all the git config variables in this same object
* file, so that programs can link against the config parser
* without having to link against all the rest of git.
*
* In particular, no need to bring in libz etc unless needed,
* even if you might want to know where the git directory etc
* are.
*/
#include "cache.h"
#include "branch.h"
#include "environment.h"
#include "repository.h"
#include "config.h"
#include "refs.h"
#include "fmt-merge-msg.h"
#include "commit.h"
#include "strvec.h"
#include "object-store.h"
#include "chdir-notify.h"
#include "shallow.h"
int trust_executable_bit = 1;
int trust_ctime = 1;
int check_stat = 1;
int has_symlinks = 1;
int minimum_abbrev = 4, default_abbrev = -1;
int ignore_case;
int assume_unchanged;
int prefer_symlink_refs;
int is_bare_repository_cfg = -1; /* unspecified */
int warn_ambiguous_refs = 1;
int warn_on_object_refname_ambiguity = 1;
int ref_paranoia = -1;
int repository_format_precious_objects;
int repository_format_worktree_config;
const char *git_commit_encoding;
const char *git_log_output_encoding;
char *apply_default_whitespace;
char *apply_default_ignorewhitespace;
const char *git_attributes_file;
const char *git_hooks_path;
int zlib_compression_level = Z_BEST_SPEED;
int core_compression_level;
int pack_compression_level = Z_DEFAULT_COMPRESSION;
int fsync_object_files;
size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE;
size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT;
size_t delta_base_cache_limit = 96 * 1024 * 1024;
unsigned long big_file_threshold = 512 * 1024 * 1024;
int pager_use_color = 1;
const char *editor_program;
const char *askpass_program;
const char *excludes_file;
enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
int read_replace_refs = 1;
char *git_replace_ref_base;
enum eol core_eol = EOL_UNSET;
int global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
char *check_roundtrip_encoding = "SHIFT-JIS";
unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
enum rebase_setup_type autorebase = AUTOREBASE_NEVER;
enum push_default_type push_default = PUSH_DEFAULT_UNSPECIFIED;
#ifndef OBJECT_CREATION_MODE
#define OBJECT_CREATION_MODE OBJECT_CREATION_USES_HARDLINKS
#endif
enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE;
char *notes_ref_name;
int grafts_replace_parents = 1;
int core_apply_sparse_checkout;
int core_sparse_checkout_cone;
int merge_log_config = -1;
int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
unsigned long pack_size_limit_cfg;
enum log_refs_config log_all_ref_updates = LOG_REFS_UNSET;
#ifndef PROTECT_HFS_DEFAULT
#define PROTECT_HFS_DEFAULT 0
#endif
int protect_hfs = PROTECT_HFS_DEFAULT;
#ifndef PROTECT_NTFS_DEFAULT
#define PROTECT_NTFS_DEFAULT 1
#endif
int protect_ntfs = PROTECT_NTFS_DEFAULT;
const char *core_fsmonitor;
/*
* The character that begins a commented line in user-editable file
* that is subject to stripspace.
*/
char comment_line_char = '#';
int auto_comment_line_char;
/* Parallel index stat data preload? */
int core_preload_index = 1;
/*
* This is a hack for test programs like test-dump-untracked-cache to
* ensure that they do not modify the untracked cache when reading it.
* Do not use it otherwise!
*/
int ignore_untracked_cache_config;
/* This is set by setup_git_dir_gently() and/or git_default_config() */
char *git_work_tree_cfg;
static char *git_namespace;
static char *super_prefix;
/*
* Repository-local GIT_* environment variables; see cache.h for details.
*/
const char * const local_repo_env[] = {
ALTERNATE_DB_ENVIRONMENT,
CONFIG_ENVIRONMENT,
CONFIG_DATA_ENVIRONMENT,
CONFIG_COUNT_ENVIRONMENT,
DB_ENVIRONMENT,
GIT_DIR_ENVIRONMENT,
GIT_WORK_TREE_ENVIRONMENT,
GIT_IMPLICIT_WORK_TREE_ENVIRONMENT,
GRAFT_ENVIRONMENT,
INDEX_ENVIRONMENT,
NO_REPLACE_OBJECTS_ENVIRONMENT,
GIT_REPLACE_REF_BASE_ENVIRONMENT,
GIT_PREFIX_ENVIRONMENT,
GIT_SUPER_PREFIX_ENVIRONMENT,
GIT_SHALLOW_FILE_ENVIRONMENT,
GIT_COMMON_DIR_ENVIRONMENT,
NULL
};
static char *expand_namespace(const char *raw_namespace)
{
struct strbuf buf = STRBUF_INIT;
struct strbuf **components, **c;
if (!raw_namespace || !*raw_namespace)
return xstrdup("");
strbuf_addstr(&buf, raw_namespace);
components = strbuf_split(&buf, '/');
strbuf_reset(&buf);
for (c = components; *c; c++)
if (strcmp((*c)->buf, "/") != 0)
strbuf_addf(&buf, "refs/namespaces/%s", (*c)->buf);
strbuf_list_free(components);
if (check_refname_format(buf.buf, 0))
die(_("bad git namespace path \"%s\""), raw_namespace);
strbuf_addch(&buf, '/');
return strbuf_detach(&buf, NULL);
}
const char *getenv_safe(struct strvec *argv, const char *name)
{
const char *value = getenv(name);
if (!value)
return NULL;
strvec_push(argv, value);
return argv->v[argv->nr - 1];
}
void setup_git_env(const char *git_dir)
{
const char *shallow_file;
const char *replace_ref_base;
struct set_gitdir_args args = { NULL };
struct strvec to_free = STRVEC_INIT;
args.commondir = getenv_safe(&to_free, GIT_COMMON_DIR_ENVIRONMENT);
args.object_dir = getenv_safe(&to_free, DB_ENVIRONMENT);
args.graft_file = getenv_safe(&to_free, GRAFT_ENVIRONMENT);
args.index_file = getenv_safe(&to_free, INDEX_ENVIRONMENT);
args.alternate_db = getenv_safe(&to_free, ALTERNATE_DB_ENVIRONMENT);
repo_set_gitdir(the_repository, git_dir, &args);
strvec_clear(&to_free);
if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
read_replace_refs = 0;
replace_ref_base = getenv(GIT_REPLACE_REF_BASE_ENVIRONMENT);
free(git_replace_ref_base);
git_replace_ref_base = xstrdup(replace_ref_base ? replace_ref_base
: "refs/replace/");
free(git_namespace);
git_namespace = expand_namespace(getenv(GIT_NAMESPACE_ENVIRONMENT));
shallow_file = getenv(GIT_SHALLOW_FILE_ENVIRONMENT);
if (shallow_file)
set_alternate_shallow_file(the_repository, shallow_file, 0);
}
int is_bare_repository(void)
{
/* if core.bare is not 'false', let's see if there is a work tree */
return is_bare_repository_cfg && !get_git_work_tree();
}
int have_git_dir(void)
{
return startup_info->have_repository
|| the_repository->gitdir;
}
const char *get_git_dir(void)
{
if (!the_repository->gitdir)
BUG("git environment hasn't been setup");
return the_repository->gitdir;
}
const char *get_git_common_dir(void)
{
if (!the_repository->commondir)
BUG("git environment hasn't been setup");
return the_repository->commondir;
}
const char *get_git_namespace(void)
{
if (!git_namespace)
BUG("git environment hasn't been setup");
return git_namespace;
}
const char *strip_namespace(const char *namespaced_ref)
{
const char *out;
if (skip_prefix(namespaced_ref, get_git_namespace(), &out))
return out;
return NULL;
}
const char *get_super_prefix(void)
{
static int initialized;
if (!initialized) {
super_prefix = xstrdup_or_null(getenv(GIT_SUPER_PREFIX_ENVIRONMENT));
initialized = 1;
}
return super_prefix;
}
static int git_work_tree_initialized;
/*
* Note. This works only before you used a work tree. This was added
* primarily to support git-clone to work in a new repository it just
* created, and is not meant to flip between different work trees.
*/
void set_git_work_tree(const char *new_work_tree)
{
struct strbuf realpath = STRBUF_INIT;
if (git_work_tree_initialized) {
strbuf_realpath(&realpath, new_work_tree, 1);
new_work_tree = realpath.buf;
if (strcmp(new_work_tree, the_repository->worktree))
die("internal error: work tree has already been set\n"
"Current worktree: %s\nNew worktree: %s",
the_repository->worktree, new_work_tree);
return;
}
git_work_tree_initialized = 1;
repo_set_worktree(the_repository, new_work_tree);
strbuf_release(&realpath);
}
const char *get_git_work_tree(void)
{
return the_repository->worktree;
}
char *get_object_directory(void)
{
if (!the_repository->objects->odb)
BUG("git environment hasn't been setup");
return the_repository->objects->odb->path;
}
int odb_mkstemp(struct strbuf *temp_filename, const char *pattern)
{
int fd;
/*
* we let the umask do its job, don't try to be more
* restrictive except to remove write permission.
*/
int mode = 0444;
git_path_buf(temp_filename, "objects/%s", pattern);
fd = git_mkstemp_mode(temp_filename->buf, mode);
if (0 <= fd)
return fd;
/* slow path */
/* some mkstemp implementations erase temp_filename on failure */
git_path_buf(temp_filename, "objects/%s", pattern);
safe_create_leading_directories(temp_filename->buf);
return xmkstemp_mode(temp_filename->buf, mode);
}
int odb_pack_keep(const char *name)
{
int fd;
fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
if (0 <= fd)
return fd;
/* slow path */
safe_create_leading_directories_const(name);
return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
}
char *get_index_file(void)
{
if (!the_repository->index_file)
BUG("git environment hasn't been setup");
return the_repository->index_file;
}
char *get_graft_file(struct repository *r)
{
if (!r->graft_file)
BUG("git environment hasn't been setup");
return r->graft_file;
}
static void set_git_dir_1(const char *path)
{
if (setenv(GIT_DIR_ENVIRONMENT, path, 1))
die(_("could not set GIT_DIR to '%s'"), path);
setup_git_env(path);
}
static void update_relative_gitdir(const char *name,
const char *old_cwd,
const char *new_cwd,
void *data)
{
char *path = reparent_relative_path(old_cwd, new_cwd, get_git_dir());
trace_printf_key(&trace_setup_key,
"setup: move $GIT_DIR to '%s'",
path);
set_git_dir_1(path);
free(path);
}
void set_git_dir(const char *path, int make_realpath)
{
struct strbuf realpath = STRBUF_INIT;
if (make_realpath) {
strbuf_realpath(&realpath, path, 1);
path = realpath.buf;
}
set_git_dir_1(path);
if (!is_absolute_path(path))
chdir_notify_register(NULL, update_relative_gitdir, NULL);
strbuf_release(&realpath);
}
const char *get_log_output_encoding(void)
{
return git_log_output_encoding ? git_log_output_encoding
: get_commit_output_encoding();
}
const char *get_commit_output_encoding(void)
{
return git_commit_encoding ? git_commit_encoding : "UTF-8";
}
static int the_shared_repository = PERM_UMASK;
static int need_shared_repository_from_config = 1;
void set_shared_repository(int value)
{
the_shared_repository = value;
need_shared_repository_from_config = 0;
}
int get_shared_repository(void)
{
if (need_shared_repository_from_config) {
const char *var = "core.sharedrepository";
const char *value;
if (!git_config_get_value(var, &value))
the_shared_repository = git_config_perm(var, value);
need_shared_repository_from_config = 0;
}
return the_shared_repository;
}
void reset_shared_repository(void)
{
need_shared_repository_from_config = 1;
}
int use_optional_locks(void)
{
return git_env_bool(GIT_OPTIONAL_LOCKS_ENVIRONMENT, 1);
}
int print_sha1_ellipsis(void)
{
/*
* Determine if the calling environment contains the variable
* GIT_PRINT_SHA1_ELLIPSIS set to "yes".
*/
static int cached_result = -1; /* unknown */
if (cached_result < 0) {
const char *v = getenv("GIT_PRINT_SHA1_ELLIPSIS");
cached_result = (v && !strcasecmp(v, "yes"));
}
return cached_result;
}