From cfabcb4cc2f0162f7e2301642e0e9b843e51225f Mon Sep 17 00:00:00 2001
From: Michael Tremer <michael.tremer@ipfire.org>
Date: Wed, 23 Jul 2025 16:59:56 +0200
Subject: [PATCH] hostapd: Introduce new WiFi modes to accomodate all different
 modes

Using just 802.11ac does not entirely cover how the hardware could be
configured. Some devices support 20, 40, 80 or even 160 MHz channels
which is now being implemented here.

The channel offsets are computed manually or will be automatically
selected by hostapd if we are using ACS.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---
 src/initscripts/packages/hostapd | 185 +++++++++++++++++++++++++------
 1 file changed, 152 insertions(+), 33 deletions(-)

diff --git a/src/initscripts/packages/hostapd b/src/initscripts/packages/hostapd
index 210b2e29b..bece75383 100644
--- a/src/initscripts/packages/hostapd
+++ b/src/initscripts/packages/hostapd
@@ -274,6 +274,36 @@ write_config() {
 		fi
 	done
 
+	# Set the channel to zero if not set
+	if [ -z "${CHANNEL}" ]; then
+		CHANNEL=0
+	fi
+
+	# Translate the old HW_MODE to the newer MODE setting
+	if [ -z "${MODE}" ]; then
+		case "${HW_MODE}" in
+			ac)
+				MODE="VHT20"
+				;;
+			an|gn)
+				MODE="HT20";
+				;;
+		esac
+	fi
+
+	# Set some default BAND if none is set
+	if [ -z "${BAND}" ]; then
+		# Use 2.4 GHz for 802.11g/n and assume 5 GHz for anything else
+		case "${MODE}" in
+			gn)
+				BAND="2g"
+				;;
+			*)
+				BAND="5g"
+				;;
+		esac
+	fi
+
 	# Header
 	echo "# Automatically generated configuration"
 	echo "# DO NOT EDIT"
@@ -302,48 +332,137 @@ write_config() {
 	echo "local_pwr_constraint=3"
 	echo "spectrum_mgmt_required=1"
 
-	# Set mode
-	case "${HW_MODE}" in
-		ax)
-			echo "hw_mode=a"
-			echo "ieee80211ax=1"
-			echo "ieee80211ac=1"
-			echo "ieee80211n=1"
-			echo "wmm_enabled=1"
-			#echo "vht_oper_chwidth=1"
-			#echo "he_oper_chwidth=1"
-			;;
-		ac)
-			echo "hw_mode=a"
-			echo "ieee80211ac=1"
-			echo "ieee80211n=1"
-			echo "wmm_enabled=1"
-			echo "vht_oper_chwidth=1"
+	# Always enable WMM
+	echo "wmm_enabled=1"
+
+	# 802.11ac
+	local enable_ac=0
+	local vht_oper_chwidth=0
+	local vht_oper_centr_freq_seg0_idx=""
+
+	case "${MODE}" in
+		VHT20|HE20)
+			enable_ac=1
 			;;
-		an|gn)
-			echo "hw_mode=${HW_MODE:0:1}"
-			echo "ieee80211n=1"
-			echo "wmm_enabled=1"
+
+		# 40 MHz Channel Width
+		VHT40|HE40)
+			enable_ac=1
+
+			# Compute the channel segment index
+			if [ "${CHANNEL}" -gt 0 ]; then
+				case "$(( (${CHANNEL} / 4) % 2 ))" in
+					0)
+						vht_oper_centr_freq_seg0_idx="$(( ${CHANNEL} - 2 ))"
+						;;
+					1)
+						vht_oper_centr_freq_seg0_idx="$(( ${CHANNEL} + 2 ))"
+						;;
+				esac
+			fi
 			;;
-		*)
-			echo "Unsupported mode '${HW_MODE}'" >&2
-			return 1
+
+		# 80 MHz Channel Width
+		VHT80|HE80)
+			enable_ac=1
+			vht_oper_chwidth=1
+
+			# Compute the channel segment index
+			if [ "${CHANNEL}" -gt 0 ]; then
+				case "$(( (${CHANNEL} / 4) % 4 ))" in
+					0)
+						vht_oper_centr_freq_seg0_idx="$(( ${CHANNEL} - 6 ))"
+						;;
+					1)
+						vht_oper_centr_freq_seg0_idx="$(( ${CHANNEL} + 6 ))"
+						;;
+					2)
+						vht_oper_centr_freq_seg0_idx="$(( ${CHANNEL} + 2 ))"
+						;;
+					3)
+						vht_oper_centr_freq_seg0_idx="$(( ${CHANNEL} - 2 ))"
+						;;
+				esac
+			fi
+			;;
+
+		# 160 MHz Channel Width
+		VHT160|HE160)
+			enable_ac=1
+			vht_oper_chwidth=2
+
+			# Compute the channel segment index
+			if [ "${CHANNEL}" -gt 0 ]; then
+				case "${CHANNEL}" in
+					36|40|44|48|52|56|60|64)
+						vht_oper_centr_freq_seg0_idx=50
+						;;
+					100|104|108|112|116|120|124|128)
+						vht_oper_centr_freq_seg0_idx=114
+						;;
+					149|153|157|161|165|169|173|177)
+						vht_oper_centr_freq_seg0_idx=163
+						;;
+				esac
+			fi
 			;;
 	esac
 
-	# Set HT capabilities
-	if [ ${#ht_caps[@]} -gt 0 ]; then
-		echo "ht_capab=${ht_caps[@]}"
+	# 802.11ax
+	local enable_ax=0
+	local he_oper_chwidth="${vht_oper_chwidth}"
+	local he_oper_centr_freq_seg0_idx="${vht_oper_centr_freq_seg0_idx}"
+
+	case "${MODE}}" in
+		HE*)
+			enable_ax=1
+			;;
+	esac
+
+	# Set hardware mode
+	case "${BAND}" in
+		5g)
+			echo "hw_mode=a"
+			;;
+		2g)
+			echo "hw_mode=g"
+			;;
+	esac
+
+	# Enable 802.11ax?
+	if [ "${enable_ax}" -eq 1 ]; then
+		echo "ieee80211ax=1"
+
+		# Configure wider channels
+		echo "he_oper_chwidth=${he_oper_chwidth}"
+		echo "he_oper_centr_freq_seg0_idx=${he_oper_centr_freq_seg0_idx}"
+
+		# Set HE capabilities
+		if [ ${#he_caps[@]} -gt 0 ]; then
+			printf "%s\n" "${he_caps[@]}"
+		fi
 	fi
 
-	# Set VHT capabilities
-	if [ ${#vht_caps[@]} -gt 0 ]; then
-		echo "vht_capab=${vht_caps[@]}"
+	# Enable 802.11ac?
+	if [ "${enable_ac}" -eq 1 ]; then
+		echo "ieee80211ac=1"
+
+		# Configure wider channels
+		echo "vht_oper_chwidth=${vht_oper_chwidth}"
+		echo "vht_oper_centr_freq_seg0_idx=${vht_oper_centr_freq_seg0_idx}"
+
+		# Set VHT capabilities
+		if [ ${#vht_caps[@]} -gt 0 ]; then
+			echo "vht_capab=${vht_caps[@]}"
+		fi
 	fi
 
-	# Set HE capabilities
-	if [ ${#he_caps[@]} -gt 0 ]; then
-		printf "%s\n" "${he_caps[@]}"
+	# Always enable 802.11n
+	echo "ieee80211n=1"
+
+	# Set HT capabilities
+	if [ ${#ht_caps[@]} -gt 0 ]; then
+		echo "ht_capab=${ht_caps[@]}"
 	fi
 
 	# Enable authentication
-- 
2.47.3