Subject: [PATCH 18/23] net/tls: remove the dead inplace_crypto code

From: Jakub Kicinski <[email-masked]>
Date: Wed, 27 Nov 2019 12:16:43 -0800

[ Upstream commit 9e5ffed37df68d0ccfb2fdc528609e23a1e70ebe ]

Looks like when BPF support was added by commit d3b18ad31f93
("tls: add bpf support to sk_msg handling") and
commit d829e9c4112b ("tls: convert to generic sk_msg interface")
it broke/removed the support for in-place crypto as added by
commit 4e6d47206c32 ("tls: Add support for inplace records
encryption").

The inplace_crypto member of struct tls_rec is dead, inited
to zero, and sometimes set to zero again. It used to be
set to 1 when record was allocated, but the skmsg code doesn't
seem to have been written with the idea of in-place crypto
in mind.

Since non trivial effort is required to bring the feature back
and we don't really have the HW to measure the benefit just
remove the left over support for now to avoid confusing readers.

Signed-off-by: Jakub Kicinski <[email-masked]>
Reviewed-by: Simon Horman <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 include/net/tls.h | 1 -
 net/tls/tls_sw.c  | 6 +-----
 2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/include/net/tls.h b/include/net/tls.h
index 9bf04a74a6cb..4e426c18645f 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -121,7 +121,6 @@ struct tls_rec {
 	struct list_head list;
 	int tx_ready;
 	int tx_flags;
-	int inplace_crypto;
 
 	struct sk_msg msg_plaintext;
 	struct sk_msg msg_encrypted;
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 8a7404c73bee..0dda7d8ac4ef 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -705,8 +705,7 @@ static int tls_push_record(struct sock *sk, int flags,
 	}
 
 	i = msg_pl->sg.start;
-	sg_chain(rec->sg_aead_in, 2, rec->inplace_crypto ?
-		 &msg_en->sg.data[i] : &msg_pl->sg.data[i]);
+	sg_chain(rec->sg_aead_in, 2, &msg_pl->sg.data[i]);
 
 	i = msg_en->sg.end;
 	sk_msg_iter_var_prev(i);
@@ -971,8 +970,6 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 			if (ret)
 				goto fallback_to_reg_send;
 
-			rec->inplace_crypto = 0;
-
 			num_zc++;
 			copied += try_to_copy;
 
@@ -1171,7 +1168,6 @@ static int tls_sw_do_sendpage(struct sock *sk, struct page *page,
 
 		tls_ctx->pending_open_record_frags = true;
 		if (full_record || eor || sk_msg_full(msg_pl)) {
-			rec->inplace_crypto = 0;
 			ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
 						  record_type, &copied, flags);
 			if (ret) {
-- 
2.20.1