in

I don't see you handling re-keying, which is supported in SW.

Added hardware offload key update support in v4

quoted

The upstream Broadcom bnxt_en driver does not yet support kTLS offload.
Testing was performed using the out-of-tree driver version
bnxt_en-1.10.3-235.1.154.0, which works without modifications.

It's a bit odd to mention that you tested some out of tree code.
Glad it works, but I don't see the relevance upstream. Please drop
the mentions of Broadcom until the driver has TLS offload support added.

Removed Broadcom bnxt_en out-of-tree driver mention in v4

quoted

--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c

@@ -319,6 +319,36 @@ static void tls_device_record_close(struct sock *sk,
      struct tls_prot_info *prot = &ctx->prot_info;
      struct page_frag dummy_tag_frag;

+     /* TLS 1.3: append content type byte before tag.
+      * Record structure: [Header (5)] + [Ciphertext + ContentType (1)] + [Tag (16)]
+      * The content type is encrypted with the ciphertext for authentication.
+      */
+     if (prot->version == TLS_1_3_VERSION) {
+             struct page_frag dummy_content_type_frag;
+             struct page_frag *content_type_pfrag = pfrag;
+
+             /* Validate record type range */
+             if (unlikely(record_type < TLS_RECORD_TYPE_CHANGE_CIPHER_SPEC ||
+                          record_type > TLS_RECORD_TYPE_ACK)) {
+                     pr_err_once("tls_device: invalid record type %u\n",
+                                 record_type);
+                     return;

This check is really odd. Why is it relevant, and yet not relevant
enough to handle cleanly? On a quick look it appears that the user
can set whatever content type they want.

Removed record_type check from tls_device_record_close() in v4

quoted

+
+             if (unlikely(pfrag->size - pfrag->offset < prot->tail_size) &&
+                 !skb_page_frag_refill(prot->tail_size, pfrag, sk->sk_allocation)) {
+                     /* Out of memory: use pre-populated dummy_page */
+                     dummy_content_type_frag.page = dummy_page;
+                     dummy_content_type_frag.offset = record_type;
+                     content_type_pfrag = &dummy_content_type_frag;
+             } else {
+                     /* Current pfrag has space or allocation succeeded - write content type */
+                     *(unsigned char *)(page_address(pfrag->page) + pfrag->offset) =
+                             record_type;

wrap at 80chars and please refactor this long line into something more
readable.

Refactored in v4

quoted

+             }
+             tls_append_frag(record, content_type_pfrag, prot->tail_size);
+     }
+
      /* append tag
       * device will fill in the tag, we just need to append a placeholder
       * use socket memory to improve coalescing (re-using a single buffer

@@ -335,7 +365,7 @@ static void tls_device_record_close(struct sock *sk,

      /* fill prepend */
      tls_fill_prepend(ctx, skb_frag_address(&record->frags[0]),
-                      record->len - prot->overhead_size,
+                      (record->len - prot->overhead_size) + prot->tail_size,
                       record_type);
 }

@@ -1089,7 +1119,8 @@ int tls_set_device_offload(struct sock *sk)
      }

      crypto_info = &ctx->crypto_send.info;
-     if (crypto_info->version != TLS_1_2_VERSION) {
+     if (crypto_info->version != TLS_1_2_VERSION &&
+         crypto_info->version != TLS_1_3_VERSION) {
              rc = -EOPNOTSUPP;
              goto release_netdev;
      }

Are all existing drivers rejecting TLS 1.3 sessions?
These days we prefer for drivers to explicitly opt into new features
to avoid surprises.

Yes, currently the following 3 drivers support tls offload and all of
them reject  TLS 1.3 sessions.
- drivers/net/ethernet/chelsio/inline_crypto/chtls
- drivers/net/ethernet/fungible/funeth/
- drivers/net/ethernet/mellanox/mlx5/core/en_accel/