1 files changed, 68 insertions, 0 deletions
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index fd4fe5d61782..5dfa41abdf8b 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2475,3 +2475,71 @@ int ieee80211_send_action_csa(struct ieee80211_sub_if_data *sdata,
 	ieee80211_tx_skb(sdata, skb);
 	return 0;
 }
+
+bool ieee80211_cs_valid(const struct ieee80211_cipher_scheme *cs)
+{
+	return !(cs == NULL || cs->cipher == 0 ||
+		 cs->hdr_len < cs->pn_len + cs->pn_off ||
+		 cs->hdr_len <= cs->key_idx_off ||
+		 cs->key_idx_shift > 7 ||
+		 cs->key_idx_mask == 0);
+}
+
+bool ieee80211_cs_list_valid(const struct ieee80211_cipher_scheme *cs, int n)
+{
+	int i;
+
+	/* Ensure we have enough iftype bitmap space for all iftype values */
+	WARN_ON((NUM_NL80211_IFTYPES / 8 + 1) > sizeof(cs[0].iftype));
+
+	for (i = 0; i < n; i++)
+		if (!ieee80211_cs_valid(&cs[i]))
+			return false;
+
+	return true;
+}
+
+const struct ieee80211_cipher_scheme *
+ieee80211_cs_get(struct ieee80211_local *local, u32 cipher,
+		 enum nl80211_iftype iftype)
+{
+	const struct ieee80211_cipher_scheme *l = local->hw.cipher_schemes;
+	int n = local->hw.n_cipher_schemes;
+	int i;
+	const struct ieee80211_cipher_scheme *cs = NULL;
+
+	for (i = 0; i < n; i++) {
+		if (l[i].cipher == cipher) {
+			cs = &l[i];
+			break;
+		}
+	}
+
+	if (!cs || !(cs->iftype & BIT(iftype)))
+		return NULL;
+
+	return cs;
+}
+
+int ieee80211_cs_headroom(struct ieee80211_local *local,
+			  struct cfg80211_crypto_settings *crypto,
+			  enum nl80211_iftype iftype)
+{
+	const struct ieee80211_cipher_scheme *cs;
+	int headroom = IEEE80211_ENCRYPT_HEADROOM;
+	int i;
+
+	for (i = 0; i < crypto->n_ciphers_pairwise; i++) {
+		cs = ieee80211_cs_get(local, crypto->ciphers_pairwise[i],
+				      iftype);
+
+		if (cs && headroom < cs->hdr_len)
+			headroom = cs->hdr_len;
+	}
+
+	cs = ieee80211_cs_get(local, crypto->cipher_group, iftype);
+	if (cs && headroom < cs->hdr_len)
+		headroom = cs->hdr_len;
+
+	return headroom;
+}