mka: Add driver op to get macsec capabilities

This also implements the macsec_get_capability for the macsec_qca
driver to maintain the existing behavior.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>

src/drivers/driver.h

@@ -3297,6 +3297,14 @@ struct wpa_driver_ops {
 
 	int (*macsec_deinit)(void *priv);
 
+	/**
+	 * macsec_get_capability - Inform MKA of this driver's capability
+	 * @priv: Private driver interface data
+	 * @cap: Driver's capability
+	 * Returns: 0 on success, -1 on failure
+	 */
+	int (*macsec_get_capability)(void *priv, enum macsec_cap *cap);
+
 	/**
 	 * enable_protect_frames - Set protect frames status
 	 * @priv: Private driver interface data

src/drivers/driver_macsec_qca.c

@@ -458,6 +458,16 @@ static int macsec_qca_macsec_deinit(void *priv)
 }
 
 
+static int macsec_qca_get_capability(void *priv, enum macsec_cap *cap)
+{
+	wpa_printf(MSG_DEBUG, "%s", __func__);
+
+	*cap = MACSEC_CAP_INTEG_AND_CONF_0_30_50;
+
+	return 0;
+}
+
+
 static int macsec_qca_enable_protect_frames(void *priv, Boolean enabled)
 {
 	struct macsec_qca_data *drv = priv;
@@ -889,6 +899,7 @@ const struct wpa_driver_ops wpa_driver_macsec_qca_ops = {
 
 	.macsec_init = macsec_qca_macsec_init,
 	.macsec_deinit = macsec_qca_macsec_deinit,
+	.macsec_get_capability = macsec_qca_get_capability,
 	.enable_protect_frames = macsec_qca_enable_protect_frames,
 	.set_replay_protect = macsec_qca_set_replay_protect,
 	.set_current_cipher_suite = macsec_qca_set_current_cipher_suite,

src/pae/ieee802_1x_kay.c

@@ -3069,13 +3069,20 @@ ieee802_1x_kay_init(struct ieee802_1x_kay_ctx *ctx, enum macsec_policy policy,
 		kay->macsec_replay_window = 0;
 		kay->macsec_confidentiality = CONFIDENTIALITY_NONE;
 	} else {
-		kay->macsec_capable = MACSEC_CAP_INTEG_AND_CONF_0_30_50;
+		if (secy_get_capability(kay, &kay->macsec_capable) < 0) {
+			os_free(kay);
+			return NULL;
+		}
+
 		kay->macsec_desired = TRUE;
 		kay->macsec_protect = TRUE;
 		kay->macsec_validate = Strict;
 		kay->macsec_replay_protect = FALSE;
 		kay->macsec_replay_window = 0;
-		kay->macsec_confidentiality = CONFIDENTIALITY_OFFSET_0;
+		if (kay->macsec_capable >= MACSEC_CAP_INTEG_AND_CONF)
+			kay->macsec_confidentiality = CONFIDENTIALITY_OFFSET_0;
+		else
+			kay->macsec_confidentiality = MACSEC_CAP_INTEGRITY;
 	}
 
 	wpa_printf(MSG_DEBUG, "KaY: state machine created");
@@ -3409,6 +3416,7 @@ ieee802_1x_kay_change_cipher_suite(struct ieee802_1x_kay *kay,
 				   unsigned int cs_index)
 {
 	struct ieee802_1x_mka_participant *participant;
+	enum macsec_cap secy_cap;
 
 	if (!kay)
 		return -1;
@@ -3427,6 +3435,12 @@ ieee802_1x_kay_change_cipher_suite(struct ieee802_1x_kay *kay,
 	kay->macsec_csindex = cs_index;
 	kay->macsec_capable = cipher_suite_tbl[kay->macsec_csindex].capable;
 
+	if (secy_get_capability(kay, &secy_cap) < 0)
+		return -3;
+
+	if (kay->macsec_capable > secy_cap)
+		kay->macsec_capable = secy_cap;
+
 	participant = ieee802_1x_kay_get_principal_participant(kay);
 	if (participant) {
 		wpa_printf(MSG_INFO, "KaY: Cipher Suite changed");

src/pae/ieee802_1x_kay.h

@@ -138,6 +138,7 @@ struct ieee802_1x_kay_ctx {
 	/* abstract wpa driver interface */
 	int (*macsec_init)(void *ctx, struct macsec_init_params *params);
 	int (*macsec_deinit)(void *ctx);
+	int (*macsec_get_capability)(void *priv, enum macsec_cap *cap);
 	int (*enable_protect_frames)(void *ctx, Boolean enabled);
 	int (*set_replay_protect)(void *ctx, Boolean enabled, u32 window);
 	int (*set_current_cipher_suite)(void *ctx, u64 cs);

src/pae/ieee802_1x_secy_ops.c

@@ -113,6 +113,26 @@ int secy_cp_control_enable_port(struct ieee802_1x_kay *kay, Boolean enabled)
 }
 
 
+int secy_get_capability(struct ieee802_1x_kay *kay, enum macsec_cap *cap)
+{
+	struct ieee802_1x_kay_ctx *ops;
+
+	if (!kay) {
+		wpa_printf(MSG_ERROR, "KaY: %s params invalid", __func__);
+		return -1;
+	}
+
+	ops = kay->ctx;
+	if (!ops || !ops->macsec_get_capability) {
+		wpa_printf(MSG_ERROR,
+			   "KaY: secy macsec_get_capability operation not supported");
+		return -1;
+	}
+
+	return ops->macsec_get_capability(ops->ctx, cap);
+}
+
+
 int secy_get_receive_lowest_pn(struct ieee802_1x_kay *kay,
 			       struct receive_sa *rxsa)
 {

src/pae/ieee802_1x_secy_ops.h

@@ -28,6 +28,7 @@ int secy_cp_control_confidentiality_offset(struct ieee802_1x_kay *kay,
 int secy_cp_control_enable_port(struct ieee802_1x_kay *kay, Boolean flag);
 
 /****** KaY -> SecY *******/
+int secy_get_capability(struct ieee802_1x_kay *kay, enum macsec_cap *cap);
 int secy_get_receive_lowest_pn(struct ieee802_1x_kay *kay,
 			       struct receive_sa *rxsa);
 int secy_get_transmit_next_pn(struct ieee802_1x_kay *kay,

wpa_supplicant/driver_i.h

@@ -715,6 +715,14 @@ static inline int wpa_drv_macsec_deinit(struct wpa_supplicant *wpa_s)
 	return wpa_s->driver->macsec_deinit(wpa_s->drv_priv);
 }
 
+static inline int wpa_drv_macsec_get_capability(struct wpa_supplicant *wpa_s,
+						enum macsec_cap *cap)
+{
+	if (!wpa_s->driver->macsec_get_capability)
+		return -1;
+	return wpa_s->driver->macsec_get_capability(wpa_s->drv_priv, cap);
+}
+
 static inline int wpa_drv_enable_protect_frames(struct wpa_supplicant *wpa_s,
 						Boolean enabled)
 {

wpa_supplicant/wpas_kay.c

@@ -38,6 +38,12 @@ static int wpas_macsec_deinit(void *priv)
 }
 
 
+static int wpas_macsec_get_capability(void *priv, enum macsec_cap *cap)
+{
+	return wpa_drv_macsec_get_capability(priv, cap);
+}
+
+
 static int wpas_enable_protect_frames(void *wpa_s, Boolean enabled)
 {
 	return wpa_drv_enable_protect_frames(wpa_s, enabled);
@@ -191,6 +197,7 @@ int ieee802_1x_alloc_kay_sm(struct wpa_supplicant *wpa_s, struct wpa_ssid *ssid)
 
 	kay_ctx->macsec_init = wpas_macsec_init;
 	kay_ctx->macsec_deinit = wpas_macsec_deinit;
+	kay_ctx->macsec_get_capability = wpas_macsec_get_capability;
 	kay_ctx->enable_protect_frames = wpas_enable_protect_frames;
 	kay_ctx->set_replay_protect = wpas_set_replay_protect;
 	kay_ctx->set_current_cipher_suite = wpas_set_current_cipher_suite;