// SPDX-License-Identifier: GPL-2.0-only OR MIT
/*
 * Copyright (C) 2023 The Falco Authors.
 *
 * This file is dual licensed under either the MIT or GPL 2. See MIT.txt
 * or GPL2.txt for full copies of the license.
 */

#include <helpers/interfaces/variable_size_event.h>

/*=============================== ENTER EVENT ===========================*/

SEC("tp_btf/sys_enter")
int BPF_PROG(poll_e, struct pt_regs *regs, long id) {
	struct auxiliary_map *auxmap = auxmap__get();
	if(!auxmap) {
		return 0;
	}

	auxmap__preload_event_header(auxmap, PPME_SYSCALL_POLL_E);

	/*=============================== COLLECT PARAMETERS  ===========================*/

	/* Get the `fds_pointer` and the number of `fds` from the syscall arguments */
	unsigned long fds_pointer = extract__syscall_argument(regs, 0);
	uint32_t nfds = (uint32_t)extract__syscall_argument(regs, 1);

	/* Parameter 1: fds (type: PT_FDLIST) */
	/* We are in the enter event so we get the requested events, the returned events are only
	 * available in the exit event.
	 */
	auxmap__store_fdlist_param(auxmap, fds_pointer, nfds, REQUESTED_EVENTS);

	/* Parameter 2: timeout (type: PT_INT64) */
	/* This is an `int` in the syscall signature but we push it as an `int64` */
	uint32_t timeout_msecs = (int32_t)extract__syscall_argument(regs, 2);
	auxmap__store_s64_param(auxmap, (int64_t)timeout_msecs);

	/*=============================== COLLECT PARAMETERS  ===========================*/

	auxmap__finalize_event_header(auxmap);

	auxmap__submit_event(auxmap);

	return 0;
}

/*=============================== ENTER EVENT ===========================*/

/*=============================== EXIT EVENT ===========================*/

SEC("tp_btf/sys_exit")
int BPF_PROG(poll_x, struct pt_regs *regs, long ret) {
	struct auxiliary_map *auxmap = auxmap__get();
	if(!auxmap) {
		return 0;
	}

	auxmap__preload_event_header(auxmap, PPME_SYSCALL_POLL_X);

	/*=============================== COLLECT PARAMETERS  ===========================*/

	/* Parameter 1: ret (type: PT_FD) */
	auxmap__store_s64_param(auxmap, ret);

	/* Get the `fds_pointer` and the number of `fds` from the syscall arguments */
	unsigned long fds_pointer = extract__syscall_argument(regs, 0);
	uint32_t nfds = (uint32_t)extract__syscall_argument(regs, 1);

	/* Parameter 2: fds (type: PT_FDLIST) */
	auxmap__store_fdlist_param(auxmap, fds_pointer, nfds, RETURNED_EVENTS);

	/*=============================== COLLECT PARAMETERS  ===========================*/

	auxmap__finalize_event_header(auxmap);

	auxmap__submit_event(auxmap);

	return 0;
}

/*=============================== EXIT EVENT ===========================*/
