From: Rohit Maheshwari <rohitm@chelsio.com>
Date: Thu, 19 Mar 2020 10:11:21 +0530
Subject: Crypto/chtls: add/delete TLS header in driver
Patch-mainline: v5.7-rc1
Git-commit: 6919a8264a3248dc0d7f945bb42f2c380f76b01e
References: jsc#SLE-15129

Kernel TLS forms TLS header in kernel during encryption and removes
while decryption before giving packet back to user application. The
similar logic is introduced in chtls code as well.

v1->v2:
- tls_proccess_cmsg() uses tls_handle_open_record() which is not required
  in TOE-TLS. Don't mix TOE with other TLS types.

Signed-off-by: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/crypto/chelsio/chtls/chtls_io.c |   73 +++++++++++++++++++++++++-------
 1 file changed, 59 insertions(+), 14 deletions(-)

--- a/drivers/crypto/chelsio/chtls/chtls_io.c
+++ b/drivers/crypto/chelsio/chtls/chtls_io.c
@@ -902,14 +902,6 @@ static int chtls_skb_copy_to_page_nocach
 	return 0;
 }
 
-/* Read TLS header to find content type and data length */
-static int tls_header_read(struct tls_hdr *thdr, struct iov_iter *from)
-{
-	if (copy_from_iter(thdr, sizeof(*thdr), from) != sizeof(*thdr))
-		return -EFAULT;
-	return (__force int)cpu_to_be16(thdr->length);
-}
-
 static int csk_mem_free(struct chtls_dev *cdev, struct sock *sk)
 {
 	return (cdev->max_host_sndbuf - sk->sk_wmem_queued);
@@ -981,6 +973,37 @@ do_interrupted:
 	goto do_rm_wq;
 }
 
+static int chtls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
+			       unsigned char *record_type)
+{
+	struct cmsghdr *cmsg;
+	int rc = -EINVAL;
+
+	for_each_cmsghdr(cmsg, msg) {
+		if (!CMSG_OK(msg, cmsg))
+			return -EINVAL;
+		if (cmsg->cmsg_level != SOL_TLS)
+			continue;
+
+		switch (cmsg->cmsg_type) {
+		case TLS_SET_RECORD_TYPE:
+			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*record_type)))
+				return -EINVAL;
+
+			if (msg->msg_flags & MSG_MORE)
+				return -EINVAL;
+
+			*record_type = *(unsigned char *)CMSG_DATA(cmsg);
+			rc = 0;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return rc;
+}
+
 int chtls_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 {
 	struct chtls_sock *csk = rcu_dereference_sk_user_data(sk);
@@ -1022,15 +1045,21 @@ int chtls_sendmsg(struct sock *sk, struc
 			goto wait_for_sndbuf;
 
 		if (is_tls_tx(csk) && !csk->tlshws.txleft) {
-			struct tls_hdr hdr;
+			unsigned char record_type = TLS_RECORD_TYPE_DATA;
 
-			recordsz = tls_header_read(&hdr, &msg->msg_iter);
-			size -= TLS_HEADER_LENGTH;
-			copied += TLS_HEADER_LENGTH;
+			if (unlikely(msg->msg_controllen)) {
+				err = chtls_proccess_cmsg(sk, msg,
+							  &record_type);
+				if (err)
+					goto out_err;
+			}
+
+			recordsz = size;
 			csk->tlshws.txleft = recordsz;
-			csk->tlshws.type = hdr.type;
+			csk->tlshws.type = record_type;
+
 			if (skb)
-				ULP_SKB_CB(skb)->ulp.tls.type = hdr.type;
+				ULP_SKB_CB(skb)->ulp.tls.type = record_type;
 		}
 
 		if (!skb || (ULP_SKB_CB(skb)->flags & ULPCB_FLAG_NO_APPEND) ||
@@ -1521,6 +1550,22 @@ found_ok_skb:
 				}
 			}
 		}
+		/* Set record type if not already done. For a non-data record,
+		 * do not proceed if record type could not be copied.
+		 */
+		if (ULP_SKB_CB(skb)->flags & ULPCB_FLAG_TLS_HDR) {
+			struct tls_hdr *thdr = (struct tls_hdr *)skb->data;
+			int cerr = 0;
+
+			cerr = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
+					sizeof(thdr->type), &thdr->type);
+
+			if (cerr && thdr->type != TLS_RECORD_TYPE_DATA)
+				return -EIO;
+			/*  don't send tls header, skip copy */
+			goto skip_copy;
+		}
+
 		if (skb_copy_datagram_msg(skb, offset, msg, avail)) {
 			if (!copied) {
 				copied = -EFAULT;