From: Jakub Kicinski kuba@kernel.org
[ Upstream commit d452d48b9f8b1a7f8152d33ef52cfd7fe1735b0a ]
We got multiple reports that multi_chunk_sendfile test case from tls selftest fails. This was sort of expected, as the original fix was never applied (see it in the first Link:). The test in question uses sendfile() with count larger than the size of the underlying file. This will make splice set MSG_MORE on all sendpage calls, meaning TLS will never close and flush the last partial record.
Eric seem to have addressed a similar problem in commit 35f9c09fe9c7 ("tcp: tcp_sendpages() should call tcp_push() once") by introducing MSG_SENDPAGE_NOTLAST. Unlike MSG_MORE MSG_SENDPAGE_NOTLAST is not set on the last call of a "pipefull" of data (PIPE_DEF_BUFFERS == 16, so every 16 pages or whenever we run out of data).
Having a break every 16 pages should be fine, TLS can pack exactly 4 pages into a record, so for aligned reads there should be no difference, unaligned may see one extra record per sendpage().
Sticking to TCP semantics seems preferable to modifying splice, but we can revisit it if real life scenarios show a regression.
Reported-by: Vadim Fedorenko vfedorenko@novek.ru Reported-by: Seth Forshee seth.forshee@canonical.com Link: https://lore.kernel.org/netdev/1591392508-14592-1-git-send-email-pooja.trive... Fixes: 3c4d7559159b ("tls: kernel TLS support") Signed-off-by: Jakub Kicinski kuba@kernel.org Tested-by: Seth Forshee seth.forshee@canonical.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/tls/tls_sw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index cdb65aa54be7..7fb5c067f429 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1150,7 +1150,7 @@ static int tls_sw_do_sendpage(struct sock *sk, struct page *page, int ret = 0; bool eor;
- eor = !(flags & (MSG_MORE | MSG_SENDPAGE_NOTLAST)); + eor = !(flags & MSG_SENDPAGE_NOTLAST); sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
/* Call the sk_stream functions to manage the sndbuf mem. */