__lstat50.c

/*
 * Copyright 2024 Gaël PORTAY
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */

#ifdef __NetBSD__
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <limits.h>
#include <dlfcn.h>
#include <fcntl.h>

#include <sys/stat.h>

#include "iamroot.h"

static int (*sym)(const char *, struct stat *);

hidden int next___lstat50(const char *path, struct stat *statbuf)
{
	if (!sym)
		sym = dlsym(RTLD_NEXT, "__lstat50");

	if (!sym)
		return __dl_set_errno_and_perror(ENOSYS, -1);

	return sym(path, statbuf);
}

int __lstat50(const char *path, struct stat *statbuf)
{
	char buf[PATH_MAX];
	int ret = -1;
	ssize_t siz;
	uid_t uid;
	gid_t gid;

	/*
	 * According to symlink(7):
	 *
	 * Various system calls do not follow links in the basename component
	 * of a pathname, and operate on the symbolic link itself. They are:
	 * lchown(2), lgetxattr(2), llistxattr(2), lremovexattr(2),
	 * lsetxattr(2), lstat(2), readlink(2), rename(2), rmdir(2), and
	 * unlink(2).
	 */
	siz = path_resolution2(AT_FDCWD, path, buf, sizeof(buf),
			       AT_SYMLINK_NOFOLLOW,
			       PATH_RESOLUTION_NOWALKALONG);
	if (siz == -1)
		goto exit;

	ret = next___lstat50(buf, statbuf);
	if (ret == -1)
		goto exit;

	uid = __get_uid(buf);
	if (uid == (uid_t)-1)
		statbuf->st_uid = 0;

	gid = __get_gid(buf);
	if (gid == (gid_t)-1)
		statbuf->st_gid = 0;

	__st_mode(buf, statbuf);
	__st_uid(buf, statbuf);
	__st_gid(buf, statbuf);

exit:
	__debug("%s(path: '%s' -> '%s', ...) -> %i\n", __func__, path, buf, ret);

	return ret;
}
#endif