tls: drop unnecessary cipher_type checks in tls offload

We should never reach tls_device_reencrypt, tls_enc_record, or
tls_enc_skb with a cipher_type that can't be offloaded. Replace those
checks with a DEBUG_NET_WARN_ON_ONCE, and use cipher_desc instead of
hard-coding offloadable cipher types.
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tls/tls_device.c

@@ -891,14 +891,8 @@ tls_device_reencrypt(struct sock *sk, struct tls_context *tls_ctx)
 	struct strp_msg *rxm;
 	char *orig_buf, *buf;
 
-	switch (tls_ctx->crypto_recv.info.cipher_type) {
-	case TLS_CIPHER_AES_GCM_128:
-	case TLS_CIPHER_AES_GCM_256:
-		break;
-	default:
-		return -EINVAL;
-	}
 	cipher_desc = get_cipher_desc(tls_ctx->crypto_recv.info.cipher_type);
+	DEBUG_NET_WARN_ON_ONCE(!cipher_desc || !cipher_desc->offloadable);
 
 	rxm = strp_msg(tls_strp_msg(sw_ctx));
 	orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE + cipher_desc->iv,

net/tls/tls_device_fallback.c

@@ -62,14 +62,8 @@ static int tls_enc_record(struct aead_request *aead_req,
 	u16 len;
 	int rc;
 
-	switch (prot->cipher_type) {
-	case TLS_CIPHER_AES_GCM_128:
-	case TLS_CIPHER_AES_GCM_256:
-		break;
-	default:
-		return -EINVAL;
-	}
 	cipher_desc = get_cipher_desc(prot->cipher_type);
+	DEBUG_NET_WARN_ON_ONCE(!cipher_desc || !cipher_desc->offloadable);
 
 	buf_size = TLS_HEADER_SIZE + cipher_desc->iv;
 	len = min_t(int, *in_len, buf_size);
@@ -338,14 +332,9 @@ static struct sk_buff *tls_enc_skb(struct tls_context *tls_ctx,
 	if (!aead_req)
 		return NULL;
 
-	switch (tls_ctx->crypto_send.info.cipher_type) {
-	case TLS_CIPHER_AES_GCM_128:
-	case TLS_CIPHER_AES_GCM_256:
-		break;
-	default:
-		goto free_req;
-	}
 	cipher_desc = get_cipher_desc(tls_ctx->crypto_send.info.cipher_type);
+	DEBUG_NET_WARN_ON_ONCE(!cipher_desc || !cipher_desc->offloadable);
+
 	buf_len = cipher_desc->salt + cipher_desc->iv + TLS_AAD_SPACE_SIZE +
 		  sync_size + cipher_desc->tag;
 	buf = kmalloc(buf_len, GFP_ATOMIC);