#!/bin/sh
#
# Copyright (C) 2019-2024, Digi International Inc.
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, you can obtain one at http://mozilla.org/MPL/2.0/.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#
# Description: create P2P link
#
# Configuration variables in '/etc/network/interfaces':
#   Mandatory:
#     p2p-peer-mac <peer-mac>
#   Optional:
#     p2p-discover-window <interval-secs>
#     p2p-freq <channel-freq>
#     p2p-local-address <local-ip>
#     p2p-local-netmask <local-netmask>
#     p2p-network-id <wpa_supplicant_conf P2P network ID>
#

# Execute only for the P2P interface
[ "${IFACE}" = "##WLAN_P2P_INTERFACE##" ] || exit 0

log() {
	if type "systemd-cat" >/dev/null 2>/dev/null; then
		systemd-cat -p "${1}" -t p2plink printf "%s" "${2}"
	else
		logger -p "${1}" -t p2plink "${2}"
	fi
}

# Exit without error if the peer MAC address is not available
[ -z "${IF_P2P_PEER_MAC}" ] && { log info "Peer MAC address not available"; exit 0; }

# wpa_cli reports lowercase MACs, so convert to lowercase
IF_P2P_PEER_MAC="$(echo "${IF_P2P_PEER_MAC}" | tr 'A-F' 'a-f')"

if [ "${MODE}" = "start" ]; then
	wpa_cli -i"${IFACE}" p2p_find && sleep 1
	for _ in $(seq "${IF_P2P_DISCOVER_WINDOW:=120}"); do
		wpa_cli -i"${IFACE}" p2p_peers discovered | grep -i -qs "${IF_P2P_PEER_MAC}" && { peer_found="1"; break; }
		sleep 1
	done
	wpa_cli -i"${IFACE}" p2p_stop_find
	[ -z "${peer_found}" ] && { log err "p2p discover: peer NOT found"; exit 1; }

	# Peer found, establish the link
	log info "Peer found, establishing the P2P link"
	wpa_cli -i"${IFACE}" p2p_connect "${IF_P2P_PEER_MAC}" pbc ${IF_P2P_NETWORK_ID:+persistent=${IF_P2P_NETWORK_ID}} ${IF_P2P_FREQ:+freq=${IF_P2P_FREQ}} auto
	for _ in $(seq 20); do
		# When a new connection is created, we need to get the index of the new interface (p2p-${IFACE}-[0-9]
		# Check for the interface matching the pattern "p2p-${IFACE}-*"
		P2P_IFNAME=$(ip link | grep -o "p2p-${IFACE}-[0-9]")
		[ -z "$P2P_IFNAME" ] && sleep 1 && continue

		if wpa_cli -i "${P2P_IFNAME}" status 2>&1 | grep -qs "^wpa_state=COMPLETED$"; then
			if wpa_cli -i "${P2P_IFNAME}" status 2>&1 | grep -qs "^mode=P2P GO$"; then
				# P2P GO side: verify the remote peer has connected
				wpa_cli -i "${P2P_IFNAME}" all_sta 2>&1 | grep -i -qs "^p2p_device_addr=${IF_P2P_PEER_MAC}$" && p2p_link_found="1"
			elif wpa_cli -i "${P2P_IFNAME}" status 2>&1 | grep -qs "^mode=station$"; then
				p2p_link_found="1"
			fi
		fi
		if [ -n "${p2p_link_found}" ]; then
			# Configure the newly created interface
			if [ -n "${IF_P2P_LOCAL_ADDRESS}" ]; then
				ifconfig "${P2P_IFNAME}" "${IF_P2P_LOCAL_ADDRESS}" ${IF_P2P_LOCAL_NETMASK:+netmask ${IF_P2P_LOCAL_NETMASK}} up
			fi
			break
		fi
		sleep 1
	done

	# Give 'ifupdown' a proper error return value if 'wpa_state' is NOT COMPLETED
	[ -n "${p2p_link_found}" ] && log info "P2P link created" || { log err "P2P link not created"; false ;}
fi