[PATCH net 0/2] net/tls: fix poll() wake up

[PATCH net 0/2] net/tls: fix poll() wake up

[Jakub Kicinski]

Hi!

This small fix + selftest series is very similar to the previous
commit 04b25a5411f9 ("net/tls: fix no wakeup on partial reads").
This time instead of recvmsg we're fixing poll wake up.

Jakub Kicinski (2):
  net/tls: fix poll ignoring partially copied records
  selftests/tls: add test for poll() with data in TLS ULP

 net/tls/tls_sw.c                  |  3 ++-
 tools/testing/selftests/net/tls.c | 26 ++++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

-- 
2.21.0

[PATCH net 1/2] net/tls: fix poll ignoring partially copied records

[Jakub Kicinski]

David reports that RPC applications which use epoll() occasionally
get stuck, and that TLS ULP causes the kernel to not wake applications,
even though read() will return data.

This is indeed true. The ctx->rx_list which holds partially copied
records is not consulted when deciding whether socket is readable.

Note that SO_RCVLOWAT with epoll() is and has always been broken for
kernel TLS. We'd need to parse all records from the TCP layer, instead
of just the first one.

Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records")
Reported-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
---
 net/tls/tls_sw.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 455a782c7658..e2385183526e 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1958,7 +1958,8 @@ bool tls_sw_stream_read(const struct sock *sk)
 		ingress_empty = list_empty(&psock->ingress_msg);
 	rcu_read_unlock();
 
-	return !ingress_empty || ctx->recv_pkt;
+	return !ingress_empty || ctx->recv_pkt ||
+		!skb_queue_empty(&ctx->rx_list);
 }
 
 static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
-- 
2.21.0

[PATCH net 2/2] selftests/tls: add test for poll() with data in TLS ULP

[Jakub Kicinski]

Add a test which checks if leftover record data in TLS
layer correctly wakes up poll().

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
---
 tools/testing/selftests/net/tls.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/tools/testing/selftests/net/tls.c b/tools/testing/selftests/net/tls.c
index 278c86134556..090fff9dbc48 100644
--- a/tools/testing/selftests/net/tls.c
+++ b/tools/testing/selftests/net/tls.c
@@ -644,6 +644,32 @@ TEST_F(tls, poll_wait)
 	EXPECT_EQ(recv(self->cfd, recv_mem, send_len, MSG_WAITALL), send_len);
 }
 
+TEST_F(tls, poll_wait_split)
+{
+	struct pollfd fd = { 0, 0, 0 };
+	char send_mem[20] = {};
+	char recv_mem[15];
+
+	fd.fd = self->cfd;
+	fd.events = POLLIN;
+	/* Send 20 bytes */
+	EXPECT_EQ(send(self->fd, send_mem, sizeof(send_mem), 0),
+		  sizeof(send_mem));
+	/* Poll with inf. timeout */
+	EXPECT_EQ(poll(&fd, 1, -1), 1);
+	EXPECT_EQ(fd.revents & POLLIN, 1);
+	EXPECT_EQ(recv(self->cfd, recv_mem, sizeof(recv_mem), MSG_WAITALL),
+		  sizeof(recv_mem));
+
+	/* Now the remaining 5 bytes of record data are in TLS ULP */
+	fd.fd = self->cfd;
+	fd.events = POLLIN;
+	EXPECT_EQ(poll(&fd, 1, -1), 1);
+	EXPECT_EQ(fd.revents & POLLIN, 1);
+	EXPECT_EQ(recv(self->cfd, recv_mem, sizeof(recv_mem), 0),
+		  sizeof(send_mem) - sizeof(recv_mem));
+}
+
 TEST_F(tls, blocking)
 {
 	size_t data = 100000;
-- 
2.21.0

Re: [PATCH net 0/2] net/tls: fix poll() wake up

[David Miller]

From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Thu,  4 Jul 2019 14:50:35 -0700

> This small fix + selftest series is very similar to the previous
> commit 04b25a5411f9 ("net/tls: fix no wakeup on partial reads").
> This time instead of recvmsg we're fixing poll wake up.

Series applied and patch #1 queued up for -stable.

Thanks!