Files
git/hook.c
Johannes Schindelin 48c171d927 find_hook(): refactor the STRIP_EXTENSION logic
When looking for a hook and not finding one, and when `STRIP_EXTENSION`
is available (read: if we're on Windows and `.exe` is the required
extension for executable programs), we want to look also for a hook with
that extension.

Previously, we added that handling into the conditional block that was
meant to handle when no hook was found (possibly providing some advice
for the user's benefit). If the hook with that file extension was found,
we'd return early from that function instead of writing out said advice,
of course.

However, we're about to introduce a safety valve to prevent hooks from
being run during a clone, to reduce the attack surface of bugs that
allow writing files to be written into arbitrary locations.

To prepare for that, refactor the logic to avoid the early return, by
separating the `STRIP_EXTENSION` handling from the conditional block
handling the case when no hook was found.

This commit is best viewed with `--patience`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2024-04-17 22:30:09 +02:00

184 lines
3.8 KiB
C

#include "cache.h"
#include "hook.h"
#include "run-command.h"
#include "config.h"
const char *find_hook(const char *name)
{
static struct strbuf path = STRBUF_INIT;
int found_hook;
strbuf_reset(&path);
strbuf_git_path(&path, "hooks/%s", name);
found_hook = access(path.buf, X_OK) >= 0;
#ifdef STRIP_EXTENSION
if (!found_hook) {
int err = errno;
strbuf_addstr(&path, STRIP_EXTENSION);
found_hook = access(path.buf, X_OK) >= 0;
if (!found_hook)
errno = err;
}
#endif
if (!found_hook) {
if (errno == EACCES && advice_enabled(ADVICE_IGNORED_HOOK)) {
static struct string_list advise_given = STRING_LIST_INIT_DUP;
if (!string_list_lookup(&advise_given, name)) {
string_list_insert(&advise_given, name);
advise(_("The '%s' hook was ignored because "
"it's not set as executable.\n"
"You can disable this warning with "
"`git config advice.ignoredHook false`."),
path.buf);
}
}
return NULL;
}
return path.buf;
}
int hook_exists(const char *name)
{
return !!find_hook(name);
}
static int pick_next_hook(struct child_process *cp,
struct strbuf *out,
void *pp_cb,
void **pp_task_cb)
{
struct hook_cb_data *hook_cb = pp_cb;
const char *hook_path = hook_cb->hook_path;
if (!hook_path)
return 0;
cp->no_stdin = 1;
strvec_pushv(&cp->env, hook_cb->options->env.v);
cp->stdout_to_stderr = 1;
cp->trace2_hook_name = hook_cb->hook_name;
cp->dir = hook_cb->options->dir;
strvec_push(&cp->args, hook_path);
strvec_pushv(&cp->args, hook_cb->options->args.v);
/*
* This pick_next_hook() will be called again, we're only
* running one hook, so indicate that no more work will be
* done.
*/
hook_cb->hook_path = NULL;
return 1;
}
static int notify_start_failure(struct strbuf *out,
void *pp_cb,
void *pp_task_cp)
{
struct hook_cb_data *hook_cb = pp_cb;
hook_cb->rc |= 1;
return 1;
}
static int notify_hook_finished(int result,
struct strbuf *out,
void *pp_cb,
void *pp_task_cb)
{
struct hook_cb_data *hook_cb = pp_cb;
struct run_hooks_opt *opt = hook_cb->options;
hook_cb->rc |= result;
if (opt->invoked_hook)
*opt->invoked_hook = 1;
return 0;
}
static void run_hooks_opt_clear(struct run_hooks_opt *options)
{
strvec_clear(&options->env);
strvec_clear(&options->args);
}
int run_hooks_opt(const char *hook_name, struct run_hooks_opt *options)
{
struct strbuf abs_path = STRBUF_INIT;
struct hook_cb_data cb_data = {
.rc = 0,
.hook_name = hook_name,
.options = options,
};
const char *const hook_path = find_hook(hook_name);
int ret = 0;
const struct run_process_parallel_opts opts = {
.tr2_category = "hook",
.tr2_label = hook_name,
.processes = 1,
.ungroup = 1,
.get_next_task = pick_next_hook,
.start_failure = notify_start_failure,
.task_finished = notify_hook_finished,
.data = &cb_data,
};
if (!options)
BUG("a struct run_hooks_opt must be provided to run_hooks");
if (options->invoked_hook)
*options->invoked_hook = 0;
if (!hook_path && !options->error_if_missing)
goto cleanup;
if (!hook_path) {
ret = error("cannot find a hook named %s", hook_name);
goto cleanup;
}
cb_data.hook_path = hook_path;
if (options->dir) {
strbuf_add_absolute_path(&abs_path, hook_path);
cb_data.hook_path = abs_path.buf;
}
run_processes_parallel(&opts);
ret = cb_data.rc;
cleanup:
strbuf_release(&abs_path);
run_hooks_opt_clear(options);
return ret;
}
int run_hooks(const char *hook_name)
{
struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
return run_hooks_opt(hook_name, &opt);
}
int run_hooks_l(const char *hook_name, ...)
{
struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
va_list ap;
const char *arg;
va_start(ap, hook_name);
while ((arg = va_arg(ap, const char *)))
strvec_push(&opt.args, arg);
va_end(ap);
return run_hooks_opt(hook_name, &opt);
}