net/tls: Move protocol constants from cipher context to tls context

Each tls context maintains two cipher contexts (one each for tx and rx
directions). For each tls session, the constants such as protocol
version, ciphersuite, iv size, associated data size etc are same for
both the directions and need to be stored only once per tls context.
Hence these are moved from 'struct cipher_context' to 'struct
tls_prot_info' and stored only once in 'struct tls_context'.
Signed-off-by: Vakul Garg <vakul.garg@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tls.h

@@ -199,15 +199,8 @@ enum {
 };
 
 struct cipher_context {
-	u16 prepend_size;
-	u16 tag_size;
-	u16 overhead_size;
-	u16 iv_size;
 	char *iv;
-	u16 rec_seq_size;
 	char *rec_seq;
-	u16 aad_size;
-	u16 tail_size;
 };
 
 union tls_crypto_context {
@@ -218,7 +211,21 @@ union tls_crypto_context {
 	};
 };
 
+struct tls_prot_info {
+	u16 version;
+	u16 cipher_type;
+	u16 prepend_size;
+	u16 tag_size;
+	u16 overhead_size;
+	u16 iv_size;
+	u16 rec_seq_size;
+	u16 aad_size;
+	u16 tail_size;
+};
+
 struct tls_context {
+	struct tls_prot_info prot_info;
+
 	union tls_crypto_context crypto_send;
 	union tls_crypto_context crypto_recv;
 
@@ -401,16 +408,26 @@ static inline bool tls_bigint_increment(unsigned char *seq, int len)
 	return (i == -1);
 }
 
+static inline struct tls_context *tls_get_ctx(const struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	return icsk->icsk_ulp_data;
+}
+
 static inline void tls_advance_record_sn(struct sock *sk,
 					 struct cipher_context *ctx,
 					 int version)
 {
-	if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct tls_prot_info *prot = &tls_ctx->prot_info;
+
+	if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
 		tls_err_abort(sk, EBADMSG);
 
 	if (version != TLS_1_3_VERSION) {
 		tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
-				     ctx->iv_size);
+				     prot->iv_size);
 	}
 }
 
@@ -420,9 +437,10 @@ static inline void tls_fill_prepend(struct tls_context *ctx,
 			     unsigned char record_type,
 			     int version)
 {
-	size_t pkt_len, iv_size = ctx->tx.iv_size;
+	struct tls_prot_info *prot = &ctx->prot_info;
+	size_t pkt_len, iv_size = prot->iv_size;
 
-	pkt_len = plaintext_len + ctx->tx.tag_size;
+	pkt_len = plaintext_len + prot->tag_size;
 	if (version != TLS_1_3_VERSION) {
 		pkt_len += iv_size;
 
@@ -475,12 +493,6 @@ static inline void xor_iv_with_seq(int version, char *iv, char *seq)
 	}
 }
 
-static inline struct tls_context *tls_get_ctx(const struct sock *sk)
-{
-	struct inet_connection_sock *icsk = inet_csk(sk);
-
-	return icsk->icsk_ulp_data;
-}
 
 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
 		const struct tls_context *tls_ctx)

net/tls/tls_device.c

@@ -247,6 +247,7 @@ static int tls_push_record(struct sock *sk,
 			   int flags,
 			   unsigned char record_type)
 {
+	struct tls_prot_info *prot = &ctx->prot_info;
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct page_frag dummy_tag_frag;
 	skb_frag_t *frag;
@@ -256,7 +257,7 @@ static int tls_push_record(struct sock *sk,
 	frag = &record->frags[0];
 	tls_fill_prepend(ctx,
 			 skb_frag_address(frag),
-			 record->len - ctx->tx.prepend_size,
+			 record->len - prot->prepend_size,
 			 record_type,
 			 ctx->crypto_send.info.version);
 
@@ -264,7 +265,7 @@ static int tls_push_record(struct sock *sk,
 	dummy_tag_frag.page = skb_frag_page(frag);
 	dummy_tag_frag.offset = 0;
 
-	tls_append_frag(record, &dummy_tag_frag, ctx->tx.tag_size);
+	tls_append_frag(record, &dummy_tag_frag, prot->tag_size);
 	record->end_seq = tp->write_seq + record->len;
 	spin_lock_irq(&offload_ctx->lock);
 	list_add_tail(&record->list, &offload_ctx->records_list);
@@ -347,6 +348,7 @@ static int tls_push_data(struct sock *sk,
 			 unsigned char record_type)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct tls_prot_info *prot = &tls_ctx->prot_info;
 	struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
 	int tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
 	int more = flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE);
@@ -376,10 +378,10 @@ static int tls_push_data(struct sock *sk,
 	 * we need to leave room for an authentication tag.
 	 */
 	max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
-			      tls_ctx->tx.prepend_size;
+			      prot->prepend_size;
 	do {
 		rc = tls_do_allocation(sk, ctx, pfrag,
-				       tls_ctx->tx.prepend_size);
+				       prot->prepend_size);
 		if (rc) {
 			rc = sk_stream_wait_memory(sk, &timeo);
 			if (!rc)
@@ -397,7 +399,7 @@ static int tls_push_data(struct sock *sk,
 				size = orig_size;
 				destroy_record(record);
 				ctx->open_record = NULL;
-			} else if (record->len > tls_ctx->tx.prepend_size) {
+			} else if (record->len > prot->prepend_size) {
 				goto last_record;
 			}
 
@@ -658,6 +660,8 @@ int tls_device_decrypted(struct sock *sk, struct sk_buff *skb)
 int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 {
 	u16 nonce_size, tag_size, iv_size, rec_seq_size;
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct tls_prot_info *prot = &tls_ctx->prot_info;
 	struct tls_record_info *start_marker_record;
 	struct tls_offload_context_tx *offload_ctx;
 	struct tls_crypto_info *crypto_info;
@@ -703,10 +707,10 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 		goto free_offload_ctx;
 	}
 
-	ctx->tx.prepend_size = TLS_HEADER_SIZE + nonce_size;
-	ctx->tx.tag_size = tag_size;
-	ctx->tx.overhead_size = ctx->tx.prepend_size + ctx->tx.tag_size;
-	ctx->tx.iv_size = iv_size;
+	prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
+	prot->tag_size = tag_size;
+	prot->overhead_size = prot->prepend_size + prot->tag_size;
+	prot->iv_size = iv_size;
 	ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 			     GFP_KERNEL);
 	if (!ctx->tx.iv) {
@@ -716,7 +720,7 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 
 	memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
 
-	ctx->tx.rec_seq_size = rec_seq_size;
+	prot->rec_seq_size = rec_seq_size;
 	ctx->tx.rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
 	if (!ctx->tx.rec_seq) {
 		rc = -ENOMEM;

net/tls/tls_main.c

@@ -435,6 +435,7 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
 				  unsigned int optlen, int tx)
 {
 	struct tls_crypto_info *crypto_info;
+	struct tls_crypto_info *alt_crypto_info;
 	struct tls_context *ctx = tls_get_ctx(sk);
 	size_t optsize;
 	int rc = 0;
@@ -445,10 +446,13 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
 		goto out;
 	}
 
-	if (tx)
+	if (tx) {
 		crypto_info = &ctx->crypto_send.info;
-	else
+		alt_crypto_info = &ctx->crypto_recv.info;
+	} else {
 		crypto_info = &ctx->crypto_recv.info;
+		alt_crypto_info = &ctx->crypto_send.info;
+	}
 
 	/* Currently we don't support set crypto info more than one time */
 	if (TLS_CRYPTO_INFO_READY(crypto_info)) {
@@ -469,6 +473,15 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
 		goto err_crypto_info;
 	}
 
+	/* Ensure that TLS version and ciphers are same in both directions */
+	if (TLS_CRYPTO_INFO_READY(alt_crypto_info)) {
+		if (alt_crypto_info->version != crypto_info->version ||
+		    alt_crypto_info->cipher_type != crypto_info->cipher_type) {
+			rc = -EINVAL;
+			goto err_crypto_info;
+		}
+	}
+
 	switch (crypto_info->cipher_type) {
 	case TLS_CIPHER_AES_GCM_128:
 	case TLS_CIPHER_AES_GCM_256: {