From 87529770f6494189f3f21252c3a83d708f1faacf Mon Sep 17 00:00:00 2001
From: Andre Heider <a.heider@gmail.com>
Date: Mon, 21 Nov 2022 17:27:20 +0100
Subject: [PATCH] utils: add and use iwinfo_format_hwmodes()

Unify how hwmodes are displayed, e.g.:
"802.11ac/ax/b/g/n" instead of "802.11bgnacax".

Luci currently uses a natural sort order, but that probably doesn't work
as intended once "be" is added, so let's do this here.

Signed-off-by: Andre Heider <a.heider@gmail.com>
---
 include/iwinfo/utils.h |  2 ++
 iwinfo_cli.c           | 13 ++-----------
 iwinfo_utils.c         | 25 +++++++++++++++++++++++++
 3 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/include/iwinfo/utils.h b/include/iwinfo/utils.h
index 1fa4f52..6fe5785 100644
--- a/include/iwinfo/utils.h
+++ b/include/iwinfo/utils.h
@@ -43,6 +43,8 @@ static inline int iwinfo_mbm2dbm(int gain)
 	return gain / 100;
 }
 
+size_t iwinfo_format_hwmodes(int modes, char *buf, size_t len);
+
 int iwinfo_ifup(const char *ifname);
 int iwinfo_ifdown(const char *ifname);
 int iwinfo_ifmac(const char *ifname);
diff --git a/iwinfo_cli.c b/iwinfo_cli.c
index b533ffe..caefac6 100644
--- a/iwinfo_cli.c
+++ b/iwinfo_cli.c
@@ -282,19 +282,10 @@ static char * format_encryption(struct iwinfo_crypto_entry *c)
 
 static char * format_hwmodes(int modes)
 {
-	static char buf[17];
+	static char buf[32] = "802.11";
 
-	if (modes <= 0)
+	if (iwinfo_format_hwmodes(modes, buf + 6, sizeof(buf) - 6) < 1)
 		snprintf(buf, sizeof(buf), "unknown");
-	else
-		snprintf(buf, sizeof(buf), "802.11%s%s%s%s%s%s%s",
-			(modes & IWINFO_80211_A) ? "a" : "",
-			(modes & IWINFO_80211_B) ? "b" : "",
-			(modes & IWINFO_80211_G) ? "g" : "",
-			(modes & IWINFO_80211_N) ? "n" : "",
-			(modes & IWINFO_80211_AC) ? "ac" : "",
-			(modes & IWINFO_80211_AD) ? "ad" : "",
-			(modes & IWINFO_80211_AX) ? "ax" : "");
 
 	return buf;
 }
diff --git a/iwinfo_utils.c b/iwinfo_utils.c
index c15b305..63ae78c 100644
--- a/iwinfo_utils.c
+++ b/iwinfo_utils.c
@@ -77,6 +77,31 @@ int iwinfo_mw2dbm(int in)
 	return (int)res;
 }
 
+size_t iwinfo_format_hwmodes(int modes, char *buf, size_t len)
+{
+	// bit numbers as per IWINFO_80211_*:  ad ac ax  a  b  g  n
+	const int order[IWINFO_80211_COUNT] = { 5, 4, 6, 0, 1, 2, 3 };
+	size_t res = 0;
+	int i;
+
+	*buf = 0;
+
+	if (!(modes & ((1 << IWINFO_80211_COUNT) - 1)))
+		return 0;
+
+	for (i = 0; i < IWINFO_80211_COUNT; i++)
+		if (modes & 1 << order[i])
+			res += snprintf(buf + res, len - res, "%s/", IWINFO_80211_NAMES[order[i]]);
+
+	if (res > 0)
+	{
+		res--;
+		buf[res] = 0;
+	}
+
+	return res;
+}
+
 int iwinfo_ifup(const char *ifname)
 {
 	struct ifreq ifr;