[PATCH] Add an option to remove 6 GHz band support

[Jordan Yates]

Devices whose radio does not support the 6 GHz band still build in the
6 GHz specific scan, channel and BSS selection logic since it is only
gated at runtime by is_6ghz_freq() and related helpers. Add
CONFIG_NO_6GHZ to replace these helpers with constant stubs so that the
compiler can remove the 6 GHz specific paths. This saves about 4 kB of
flash on a Cortex-M33 build with the nRF7002.

By default 6GHz support remains enabled.

Signed-off-by: Jordan Yates <jordan.yates.au at gmail.com>
---
 src/common/ieee802_11_common.c    |  2 ++
 src/common/ieee802_11_common.h    | 17 +++++++++++++++++
 wpa_supplicant/Android.mk         |  4 ++++
 wpa_supplicant/Makefile           |  4 ++++
 wpa_supplicant/android.config     |  3 +++
 wpa_supplicant/defconfig          |  3 +++
 wpa_supplicant/events.c           |  4 ++++
 wpa_supplicant/wpa_supplicant.c   |  2 ++
 wpa_supplicant/wpa_supplicant_i.h |  8 ++++++++
 9 files changed, 47 insertions(+)

diff --git a/src/common/ieee802_11_common.c b/src/common/ieee802_11_common.c
index 0a1e9a67b..29e62d056 100644
--- a/src/common/ieee802_11_common.c
+++ b/src/common/ieee802_11_common.c
@@ -3128,6 +3128,7 @@ int center_idx_to_bw_6ghz(u8 idx)
 }
 
 
+#ifndef CONFIG_NO_6GHZ
 bool is_6ghz_freq(int freq)
 {
 	if (freq < 5935 || freq > 7115)
@@ -3167,6 +3168,7 @@ bool is_6ghz_psc_frequency(int freq)
 
 	return false;
 }
+#endif /* CONFIG_NO_6GHZ */
 
 
 /**
diff --git a/src/common/ieee802_11_common.h b/src/common/ieee802_11_common.h
index 8dc38e215..2f4b7f7b4 100644
--- a/src/common/ieee802_11_common.h
+++ b/src/common/ieee802_11_common.h
@@ -365,9 +365,26 @@ int oper_class_bw_to_int(const struct oper_class_map *map);
 bool is_24ghz_freq(int freq);
 bool is_5ghz_freq(int freq);
 int center_idx_to_bw_6ghz(u8 idx);
+#ifdef CONFIG_NO_6GHZ
+static inline bool is_6ghz_freq(int freq)
+{
+	return false;
+}
+
+static inline bool is_6ghz_op_class(u8 op_class)
+{
+	return false;
+}
+
+static inline bool is_6ghz_psc_frequency(int freq)
+{
+	return false;
+}
+#else /* CONFIG_NO_6GHZ */
 bool is_6ghz_freq(int freq);
 bool is_6ghz_op_class(u8 op_class);
 bool is_6ghz_psc_frequency(int freq);
+#endif /* CONFIG_NO_6GHZ */
 int get_6ghz_sec_channel(int channel);
 
 bool is_same_band(int freq1, int freq2);
diff --git a/wpa_supplicant/Android.mk b/wpa_supplicant/Android.mk
index 8efd0c979..523688059 100644
--- a/wpa_supplicant/Android.mk
+++ b/wpa_supplicant/Android.mk
@@ -499,6 +499,10 @@ else
 OBJS += wmm_ac.c
 endif
 
+ifdef CONFIG_NO_6GHZ
+L_CFLAGS += -DCONFIG_NO_6GHZ
+endif
+
 ifdef CONFIG_NO_ROBUST_AV
 L_CFLAGS += -DCONFIG_NO_ROBUST_AV
 else
diff --git a/wpa_supplicant/Makefile b/wpa_supplicant/Makefile
index a2c689295..bad615e3a 100644
--- a/wpa_supplicant/Makefile
+++ b/wpa_supplicant/Makefile
@@ -561,6 +561,10 @@ else
 OBJS += wmm_ac.o
 endif
 
+ifdef CONFIG_NO_6GHZ
+CFLAGS += -DCONFIG_NO_6GHZ
+endif
+
 ifdef CONFIG_NO_ROBUST_AV
 CFLAGS += -DCONFIG_NO_ROBUST_AV
 else
diff --git a/wpa_supplicant/android.config b/wpa_supplicant/android.config
index 5ae3808fb..00376e238 100644
--- a/wpa_supplicant/android.config
+++ b/wpa_supplicant/android.config
@@ -554,6 +554,9 @@ CONFIG_WEP=y
 # Disable support for WMM admission control
 #CONFIG_NO_WMM_AC=y
 
+# Disable support for the 6 GHz band
+#CONFIG_NO_6GHZ=y
+
 # Wi-Fi Aware unsynchronized service discovery (NAN USD)
 #CONFIG_NAN_USD=y
 
diff --git a/wpa_supplicant/defconfig b/wpa_supplicant/defconfig
index 3ecd1e5f7..2b1fcb952 100644
--- a/wpa_supplicant/defconfig
+++ b/wpa_supplicant/defconfig
@@ -675,6 +675,9 @@ CONFIG_DPP2=y
 # Disable support for WMM admission control
 #CONFIG_NO_WMM_AC=y
 
+# Disable support for the 6 GHz band
+#CONFIG_NO_6GHZ=y
+
 # Wi-Fi Aware unsynchronized service discovery (NAN USD)
 #CONFIG_NAN_USD=y
 
diff --git a/wpa_supplicant/events.c b/wpa_supplicant/events.c
index 7083d811e..f9940082a 100644
--- a/wpa_supplicant/events.c
+++ b/wpa_supplicant/events.c
@@ -2710,8 +2710,12 @@ static int _wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
 		ap = 1;
 #endif /* CONFIG_AP */
 
+#ifdef CONFIG_NO_6GHZ
+	trigger_6ghz_scan = false;
+#else /* CONFIG_NO_6GHZ */
 	trigger_6ghz_scan = wpa_s->crossed_6ghz_dom &&
 		wpa_s->last_scan_all_chan;
+#endif /* CONFIG_NO_6GHZ */
 	wpa_s->crossed_6ghz_dom = false;
 	wpa_s->last_scan_all_chan = false;
 
diff --git a/wpa_supplicant/wpa_supplicant.c b/wpa_supplicant/wpa_supplicant.c
index e167cf9dd..0bf7889b8 100644
--- a/wpa_supplicant/wpa_supplicant.c
+++ b/wpa_supplicant/wpa_supplicant.c
@@ -11267,6 +11267,7 @@ int wpa_drv_send_action(struct wpa_supplicant *wpa_s, unsigned int freq,
 }
 
 
+#ifndef CONFIG_NO_6GHZ
 bool wpas_is_6ghz_supported(struct wpa_supplicant *wpa_s, bool only_enabled)
 {
 	struct hostapd_channel_data *chnl;
@@ -11287,6 +11288,7 @@ bool wpas_is_6ghz_supported(struct wpa_supplicant *wpa_s, bool only_enabled)
 
 	return false;
 }
+#endif /* CONFIG_NO_6GHZ */
 
 
 bool wpas_ap_supports_rsn_overriding(struct wpa_supplicant *wpa_s,
diff --git a/wpa_supplicant/wpa_supplicant_i.h b/wpa_supplicant/wpa_supplicant_i.h
index 7b7b79d59..d7f740116 100644
--- a/wpa_supplicant/wpa_supplicant_i.h
+++ b/wpa_supplicant/wpa_supplicant_i.h
@@ -2259,7 +2259,15 @@ void wpas_pasn_auth_trigger(struct wpa_supplicant *wpa_s,
 void wpas_pasn_auth_work_done(struct wpa_supplicant *wpa_s, int status);
 struct sae_pt * wpas_pasn_sae_derive_pt_for_eppke(struct wpa_ssid *ssid,
 						  int group);
+#ifdef CONFIG_NO_6GHZ
+static inline bool wpas_is_6ghz_supported(struct wpa_supplicant *wpa_s,
+					  bool only_enabled)
+{
+	return false;
+}
+#else /* CONFIG_NO_6GHZ */
 bool wpas_is_6ghz_supported(struct wpa_supplicant *wpa_s, bool only_enabled);
+#endif /* CONFIG_NO_6GHZ */
 
 bool wpa_is_non_eht_scs_traffic_desc_supported(struct wpa_bss *bss);
 bool wpas_ap_link_address(struct wpa_supplicant *wpa_s, const u8 *addr);
-- 
2.53.0