From 55a8eb85ebb84e7a397f1a7628743a162a1eb08f Mon Sep 17 00:00:00 2001
From: billz <billzimmerman@gmail.com>
Date: Sun, 5 Nov 2023 10:05:16 +0000
Subject: [PATCH] Initial commit

---
 src/RaspAP/Parsers/IwParser.php | 85 +++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100644 src/RaspAP/Parsers/IwParser.php

diff --git a/src/RaspAP/Parsers/IwParser.php b/src/RaspAP/Parsers/IwParser.php
new file mode 100644
index 00000000..324935cf
--- /dev/null
+++ b/src/RaspAP/Parsers/IwParser.php
@@ -0,0 +1,85 @@
+<?php
+
+/**
+ * Linux iw parser class
+ *
+ * @description Parses output of iw to determine properties of a given physical device (phy)
+ * @author      Bill Zimmerman <billzimmerman@gmail.com>
+ * @license     https://github.com/raspap/raspap-webgui/blob/master/LICENSE
+ * @see         https://wireless.wiki.kernel.org/en/users/Documentation/iw
+ */
+
+declare(strict_types=1);
+
+namespace RaspAP\Parsers;
+
+class IwParser {
+    private $iw_output;
+
+    public function __construct(string $interface = 'wlan0') {
+
+        // Resolve physical device for selected interface
+        $iface = escapeshellarg($interface);
+        exec("iw dev | awk -v iface=".$iface." '/^phy#/ { phy = $0 } $1 == \"Interface\" { interface = $2 } interface == iface { print phy }'", $return);
+        $phy = $return[0];
+
+        // Fetch 'iw info' output for phy
+        $this->iw_output = shell_exec("iw $phy info");
+    }
+
+    public function parseIwList() {
+        
+        /**
+         * (no IR): the AP won't Initiate Radiation until a DFS scan (or similar) is complete on these bands.
+         * (radar detection): the specified channels are shared with radar equipment.
+         * (disabled): self-explanatory.
+         */
+        $excluded = array(
+            "(no IR, radar detection)",
+            "(radar detection)",
+            "(disabled)",
+            "(no IR)"
+        );
+        $excluded_pattern = implode('|', array_map('preg_quote', $excluded));
+        $pattern = '/\*\s+(\d+)\s+MHz \[(\d+)\] \(([\d.]+) dBm\)\s(?!' .$excluded_pattern. ')/';
+        $supportedFrequencies = [];
+
+        // Match iw_output containing supported frequencies
+        preg_match_all($pattern, $this->iw_output, $matches, PREG_SET_ORDER, 0);
+
+        foreach ($matches as $match) {
+            $frequency = [
+                'MHz' => (int)$match[1],
+                'Channel' => (int)$match[2],
+                'dBm' => (float)$match[3],
+            ];
+            $supportedFrequencies[] = $frequency;
+        }
+        return $supportedFrequencies;
+    }
+
+    /**
+     * Converts an ieee80211 frequency to a channel value
+     * Adapted from iw source
+     * @param int $freq
+     * @see https://git.kernel.org/pub/scm/linux/kernel/git/jberg/iw.git/tree/util.c 
+     */
+    public function ieee80211_frequency_to_channel(int $freq)
+    {
+        /* see 802.11-2007 17.3.8.3.2 and Annex J */
+        if ($freq == 2484) {
+            return 14;
+        } else if ($freq < 2484) {
+            return ($freq - 2407) / 5;
+        } else if ($freq >= 4910 && $freq <= 4980) {
+            return ($freq - 4000) / 5;
+        } else if ($freq <= 45000) { /* DMG band lower limit */
+            return ($freq - 5000) / 5;
+        } else if ($freq >= 58320 && $freq <= 64800) {
+            return ($freq - 56160) / 2160;
+        } else {
+            return 0;
+        }
+    }
+}
+