From 1b4aa2ca01c5d0bd45213187e6a58b4cc0f57547 Mon Sep 17 00:00:00 2001
From: Michael Tremer <michael.tremer@ipfire.org>
Date: Thu, 21 Mar 2019 20:22:56 +0100
Subject: [PATCH] wireless-ap: Enable ACS only for ath* devices

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---
 src/functions/functions.hostapd  |  6 ++++++
 src/functions/functions.phy      | 22 ++++++++++++++++++++++
 src/functions/functions.wireless | 13 +++++++++++++
 src/hooks/ports/wireless-ap      |  9 ++++++++-
 4 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/src/functions/functions.hostapd b/src/functions/functions.hostapd
index 57f8c1e4..9024ab25 100644
--- a/src/functions/functions.hostapd
+++ b/src/functions/functions.hostapd
@@ -111,6 +111,12 @@ hostapd_config_write() {
 		assert isset key
 	fi
 
+	# With channel 0, ACS must be supported
+	if [ ${channel} -eq 0 ] && ! wireless_supports_acs "${device}"; then
+		error "ACS requested, but not supported by ${device}"
+		return ${EXIT_ERROR}
+	fi
+
 	# Check channel bandwidth for validity
 	if isset channel_bandwidth && ! wireless_channel_bandwidth_is_valid "${mode}" "${channel_bandwidth}"; then
 		error "Invalid channel bandwidth for ${mode}: ${channel_bandwidth}"
diff --git a/src/functions/functions.phy b/src/functions/functions.phy
index 064ca7b6..ee0f2a2e 100644
--- a/src/functions/functions.phy
+++ b/src/functions/functions.phy
@@ -189,6 +189,28 @@ phy_supports_ht_capability() {
 	list_match "${capability}" $(__phy_list_ht_capabilities "${phy}")
 }
 
+# Returns TRUE if the PHY supports ACS
+phy_supports_acs() {
+	local phy="${1}"
+	assert isset phy
+
+	local driver="$(phy_get_driver "${phy}")"
+	if ! isset driver; then
+		return ${EXIT_ERROR}
+	fi
+
+	# This is basically a whilelist of drivers which support this
+	# There is no better detection
+	case "${driver}" in
+		ath10k_*|ath9k|ath5k)
+			return ${EXIT_TRUE}
+			;;
+		*)
+			return ${EXIT_FALSE}
+			;;
+	esac
+}
+
 # Returns TRUE if the PHY supports DFS
 phy_supports_dfs() {
 	local phy="${1}"
diff --git a/src/functions/functions.wireless b/src/functions/functions.wireless
index 0437d27b..9e72fe0b 100644
--- a/src/functions/functions.wireless
+++ b/src/functions/functions.wireless
@@ -536,6 +536,19 @@ wireless_get_vht_caps() {
 	network-phy-list-vht-caps "${phy}"
 }
 
+wireless_supports_acs() {
+	local device="${1}"
+	assert isset device
+
+	local phy="$(device_get_phy "${device}")"
+	if ! isset phy; then
+		log ERROR "Could not determine PHY for ${device}"
+		return ${EXIT_ERROR}
+	fi
+
+	phy_supports_acs "${phy}"
+}
+
 wireless_supports_dfs() {
 	local device="${1}"
 	assert isset device
diff --git a/src/hooks/ports/wireless-ap b/src/hooks/ports/wireless-ap
index 983f0f97..0c42b61c 100644
--- a/src/hooks/ports/wireless-ap
+++ b/src/hooks/ports/wireless-ap
@@ -28,7 +28,7 @@ HOOK_SETTINGS="${HOOK_SETTINGS} ENCRYPTION KEY SSID"
 
 ADDRESS=$(mac_generate)
 BROADCAST_SSID=on
-CHANNEL=0
+CHANNEL=
 CHANNEL_BANDWIDTH=
 ENCRYPTION=""
 KEY=""
@@ -125,6 +125,13 @@ hook_parse_cmdline() {
 		return ${EXIT_ERROR}
 	fi
 
+	# Automatically enable ACS if no channel is set and ACS is available
+	if ! isset CHANNEL && phy_supports_acs "${PHY}"; then
+		CHANNEL="0"
+
+		log INFO "Automatic Channel Selection (ACS) enabled"
+	fi
+
 	# Channel bandwidth must match the mode
 	if isset CHANNEL_BANDWIDTH && ! wireless_channel_bandwidth_is_valid "${MODE}" "${CHANNEL_BANDWIDTH}"; then
 		error "Channel Bandwidth '${CHANNEL_BANDWIDTH}' is not supported for ${MODE}"
-- 
2.39.2