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>

1 files changed, 25 insertions, 0 deletions

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;