From 50cf12cbb527cfd35034948da7fd840f69101c9d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joan=20Bruguera=20Mic=C3=B3?= <joanbrugueram@gmail.com>
Date: Sat, 23 Dec 2023 20:00:34 +0000
Subject: [PATCH] Update frequency parsing for iw 6.7 compatibility

Since iw 6.7, which adds 802.11ah support, iw may print fractional
frequencies (e.g. 917.4 MHz). The change in the formatting code can
also affect frequencies in the 2.4 and 5 GHz bands, so a frequency
that used to be shown as "2412 MHz" may now be shown as "2412.0 MHz".

This breaks the parsing logic in `can_transmit_to_channel`,
`ieee80211_frequency_to_channel` and `is_5ghz_frequency`.
The problem in `can_transmit_to_channel` causes an error when creating
an AP, due the frequency not being detected as supported ("ERROR:
Your adapter can not transmit to channel 1, frequency band 2.4GHz.").

Fix this by changing the parsing logic to accept a trailing ".0"
(or even ".00", etc.) suffix for the existing 2.4 and 5 GHz bands.

See also: https://git.kernel.org/pub/scm/linux/kernel/git/jberg/iw.git/commit/?id=f2d9f5b52677f5414dc194be94b5916d2b080eab
          https://git.kernel.org/pub/scm/linux/kernel/git/jberg/iw.git/commit/?id=e2224c729840cc33c6ea89ba5e91b69f79c88e85
          https://git.kernel.org/pub/scm/linux/kernel/git/jberg/iw.git/commit/?id=1bc6ab0abbb6f26f35d826d166d06bc28ae47b6b
---
 src/scripts/create_ap | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/scripts/create_ap b/src/scripts/create_ap
index bf52b24..20efc7b 100755
--- a/src/scripts/create_ap
+++ b/src/scripts/create_ap
@@ -321,9 +321,9 @@ can_transmit_to_channel() {
 
     if [[ $USE_IWCONFIG -eq 0 ]]; then
         if [[ $FREQ_BAND == 2.4 ]]; then
-            CHANNEL_INFO=$(get_adapter_info ${IFACE} | grep " 24[0-9][0-9] MHz \[${CHANNEL_NUM}\]")
+            CHANNEL_INFO=$(get_adapter_info ${IFACE} | grep " 24[0-9][0-9]\(\.0\+\)\? MHz \[${CHANNEL_NUM}\]")
         else
-            CHANNEL_INFO=$(get_adapter_info ${IFACE} | grep " \(49[0-9][0-9]\|5[0-9]\{3\}\) MHz \[${CHANNEL_NUM}\]")
+            CHANNEL_INFO=$(get_adapter_info ${IFACE} | grep " \(49[0-9][0-9]\|5[0-9]\{3\}\)\(\.0\+\)\? MHz \[${CHANNEL_NUM}\]")
         fi
         [[ -z "${CHANNEL_INFO}" ]] && return 1
         [[ "${CHANNEL_INFO}" == *no\ IR* ]] && return 1
@@ -339,7 +339,9 @@ can_transmit_to_channel() {
 
 # taken from iw/util.c
 ieee80211_frequency_to_channel() {
-    local FREQ=$1
+    local FREQ_MAYBE_FRACTIONAL=$1
+    local FREQ=${FREQ_MAYBE_FRACTIONAL%.*}
+
     if [[ $FREQ -eq 2484 ]]; then
         echo 14
     elif [[ $FREQ -lt 2484 ]]; then
@@ -356,7 +358,7 @@ ieee80211_frequency_to_channel() {
 }
 
 is_5ghz_frequency() {
-    [[ $1 =~ ^(49[0-9]{2})|(5[0-9]{3})$ ]]
+    [[ $1 =~ ^(49[0-9]{2})|(5[0-9]{3})(\.0+)?$ ]]
 }
 
 is_wifi_connected() {