wiphy: Add wiphy_get_rsnxe

Returns a template RSNX element that can be further modified by callers
to set any additional capabilities if required.  wiphy will fill in
those capabilities that are driver / firmware dependent.

src/wiphy.c

@@ -551,6 +551,26 @@ const uint8_t *wiphy_get_rm_enabled_capabilities(struct wiphy *wiphy)
 	return wiphy->rm_enabled_capabilities;
 }
 
+bool wiphy_get_rsnxe(const struct wiphy *wiphy, uint8_t *buf, size_t len)
+{
+	if (len < 3)
+		return false;
+
+	buf[0] = IE_TYPE_RSNX;
+	buf[1] = 1;
+
+	/*
+	 * Lower 4 bits of the first octet:
+	 * The length of the Extended RSN Capabilities field, in octets,
+	 * minus 1, i.e., n - 1.
+	 */
+	buf[2] = 0;
+
+	/* No other bits set for now */
+
+	return true;
+}
+
 static void wiphy_address_constrain(struct wiphy *wiphy, uint8_t addr[static 6])
 {
 	switch (mac_randomize_bytes) {

src/wiphy.h

@@ -101,6 +101,7 @@ const uint8_t *wiphy_get_permanent_address(struct wiphy *wiphy);
 const uint8_t *wiphy_get_extended_capabilities(struct wiphy *wiphy,
 							uint32_t iftype);
 const uint8_t *wiphy_get_rm_enabled_capabilities(struct wiphy *wiphy);
+bool wiphy_get_rsnxe(const struct wiphy *wiphy, uint8_t *buf, size_t len);
 void wiphy_get_reg_domain_country(struct wiphy *wiphy, char *out);
 
 void wiphy_generate_random_address(struct wiphy *wiphy, uint8_t addr[static 6]);