netdev: Centralize mmpdu validation

Instead of requiring each auth_proto to perform validation of the frames
received via rx_authenticate & rx_associate, have netdev itself perform
the mpdu validation.  This is unlikely to happen anyway since the kernel
performs its own frame validation.  Print a warning in case the
validation fails.

src/fils.c

@@ -338,8 +338,8 @@ static int fils_rx_authenticate(struct auth_proto *driver, const uint8_t *frame,
 				size_t len)
 {
 	struct fils_sm *fils = l_container_of(driver, struct fils_sm, ap);
-	const struct mmpdu_header *hdr = mpdu_validate(frame, len);
+	const struct mmpdu_header *hdr = (const struct mmpdu_header *) frame;
-	const struct mmpdu_authentication *auth;
+	const struct mmpdu_authentication *auth = mmpdu_body(hdr);
 	uint16_t alg;
 	struct ie_tlv_iter iter;
 	const uint8_t *anonce = NULL;
@@ -350,13 +350,6 @@ static int fils_rx_authenticate(struct auth_proto *driver, const uint8_t *frame,
 	const uint8_t *mde = NULL;
 	const uint8_t *fte = NULL;
 
-	if (!hdr) {
-		l_debug("Auth frame header did not validate");
-		return -EBADMSG;
-	}
-
-	auth = mmpdu_body(hdr);
-
 	if (auth->status != 0) {
 		l_debug("invalid status %u", auth->status);
 		return L_LE16_TO_CPU(auth->status);
@@ -453,8 +446,8 @@ static int fils_rx_associate(struct auth_proto *driver, const uint8_t *frame,
 				size_t len)
 {
 	struct fils_sm *fils = l_container_of(driver, struct fils_sm, ap);
-	const struct mmpdu_header *hdr = mpdu_validate(frame, len);
+	const struct mmpdu_header *hdr = (const struct mmpdu_header *) frame;
-	const struct mmpdu_association_response *assoc;
+	const struct mmpdu_association_response *assoc = mmpdu_body(hdr);
 	struct ie_tlv_iter iter;
 	uint8_t key_rsc[8];
 	const uint8_t *gtk = NULL;
@@ -470,13 +463,6 @@ static int fils_rx_associate(struct auth_proto *driver, const uint8_t *frame,
 	uint8_t data[44];
 	uint8_t *ptr = data;
 
-	if (!hdr) {
-		l_debug("Assoc frame header did not validate");
-		return -EBADMSG;
-	}
-
-	assoc = mmpdu_body(hdr);
-
 	if (assoc->status_code != 0)
 		return L_CPU_TO_LE16(assoc->status_code);
 

src/netdev.c

@@ -2400,10 +2400,19 @@ static void netdev_authenticate_event(struct l_genl_msg *msg,
 		}
 	}
 
-	if (!frame)
+	if (L_WARN_ON(!frame))
 		goto auth_error;
 
 	if (netdev->ap) {
+		const struct mmpdu_header *hdr;
+		const struct mmpdu_authentication *auth;
+
+		if (L_WARN_ON(!(hdr = mpdu_validate(frame, frame_len))))
+			goto auth_error;
+
+		auth = mmpdu_body(hdr);
+		status_code = L_CPU_TO_LE16(auth->status);
+
 		ret = auth_proto_rx_authenticate(netdev->ap, frame, frame_len);
 		if (ret == 0 || ret == -EAGAIN)
 			return;
@@ -2468,10 +2477,19 @@ static void netdev_associate_event(struct l_genl_msg *msg,
 		}
 	}
 
-	if (!frame)
+	if (L_WARN_ON(!frame))
 		goto assoc_failed;
 
 	if (netdev->ap) {
+		const struct mmpdu_header *hdr;
+		const struct mmpdu_association_response *assoc;
+
+		if (L_WARN_ON(!(hdr = mpdu_validate(frame, frame_len))))
+			goto assoc_failed;
+
+		assoc = mmpdu_body(hdr);
+		status_code = L_CPU_TO_LE16(assoc->status_code);
+
 		ret = auth_proto_rx_associate(netdev->ap, frame, frame_len);
 		if (ret == 0) {
 			bool fils = !!(netdev->handshake->akm_suite &

src/owe.c

@@ -240,8 +240,8 @@ static int owe_rx_associate(struct auth_proto *ap, const uint8_t *frame,
 {
 	struct owe_sm *owe = l_container_of(ap, struct owe_sm, ap);
 
-	const struct mmpdu_header *mpdu = NULL;
+	const struct mmpdu_header *mpdu = (const struct mmpdu_header *) frame;
-	const struct mmpdu_association_response *body;
+	const struct mmpdu_association_response *body = mmpdu_body(mpdu);
 	struct ie_tlv_iter iter;
 	size_t owe_dh_len = 0;
 	const uint8_t *owe_dh = NULL;
@@ -249,14 +249,6 @@ static int owe_rx_associate(struct auth_proto *ap, const uint8_t *frame,
 	bool akm_found = false;
 	const void *data;
 
-	mpdu = mpdu_validate(frame, len);
-	if (!mpdu) {
-		l_error("could not process frame");
-		return -EBADMSG;
-	}
-
-	body = mmpdu_body(mpdu);
-
 	if (L_LE16_TO_CPU(body->status_code) ==
 				MMPDU_STATUS_CODE_UNSUPP_FINITE_CYCLIC_GROUP) {
 		if (!owe_retry(owe))

src/sae.c

@@ -1230,16 +1230,10 @@ static int sae_rx_authenticate(struct auth_proto *ap,
 				const uint8_t *frame, size_t len)
 {
 	struct sae_sm *sm = l_container_of(ap, struct sae_sm, ap);
-	const struct mmpdu_header *hdr = mpdu_validate(frame, len);
+	const struct mmpdu_header *hdr = (const struct mmpdu_header *) frame;
-	const struct mmpdu_authentication *auth;
+	const struct mmpdu_authentication *auth = mmpdu_body(hdr);
 	int ret;
 
-	if (!hdr) {
-		l_debug("Auth frame header did not validate");
-		return -EBADMSG;
-	}
-
-	auth = mmpdu_body(hdr);
 	len -= mmpdu_header_len(hdr);
 
 	ret = sae_verify_packet(sm, L_LE16_TO_CPU(auth->transaction_sequence),
@@ -1267,16 +1261,8 @@ static int sae_rx_authenticate(struct auth_proto *ap,
 static int sae_rx_associate(struct auth_proto *ap, const uint8_t *frame,
 				size_t len)
 {
-	const struct mmpdu_header *mpdu = NULL;
+	const struct mmpdu_header *mpdu = (const struct mmpdu_header *)frame;
-	const struct mmpdu_association_response *body;
+	const struct mmpdu_association_response *body = mmpdu_body(mpdu);
-
-	mpdu = mpdu_validate(frame, len);
-	if (!mpdu) {
-		l_error("could not process frame");
-		return -EBADMSG;
-	}
-
-	body = mmpdu_body(mpdu);
 
 	if (body->status_code != 0)
 		return -EPROTO;