Allow userspace to end a TLS record without supplying any data by calling
send()/sendto()/sendmsg() with no data and no MSG_MORE flag. This can be
used to flush a previous send/splice that had MSG_MORE or SPLICE_F_MORE set
or a sendfile() that was incomplete.
Without this, a zero-length send to tls-sw is just ignored. I think
tls-device will do the right thing without modification.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Chuck Lever <chuck.lever@xxxxxxxxxx>
cc: Boris Pismenny <borisp@xxxxxxxxxx>
cc: John Fastabend <john.fastabend@xxxxxxxxx>
cc: Jakub Kicinski <kuba@xxxxxxxxxx>
cc: Eric Dumazet <edumazet@xxxxxxxxxx>
cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
cc: Paolo Abeni <pabeni@xxxxxxxxxx>
cc: Jens Axboe <axboe@xxxxxxxxx>
cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
cc: netdev@xxxxxxxxxxxxxxx
---
net/tls/tls_sw.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index cac1adc968e8..6aa6d17888f5 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -945,7 +945,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
struct tls_rec *rec;
int required_size;
int num_async = 0;
- bool full_record;
+ bool full_record = false;
int record_room;
int num_zc = 0;
int orig_size;
@@ -971,6 +971,9 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
}
}
+ if (!msg_data_left(msg) && eor)
+ goto just_flush;
+
while (msg_data_left(msg)) {
if (sk->sk_err) {
ret = -sk->sk_err;
@@ -1082,6 +1085,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
*/
tls_ctx->pending_open_record_frags = true;
copied += try_to_copy;
+just_flush:
if (full_record || eor) {
ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
record_type, &copied,
