Subject: [RFC net-next 14/14] tun: run xdp prog when tun is read from file interface

From: Prashant Bhole <[email-masked]>
Date: Wed, 18 Dec 2019 17:10:50 +0900

It handles the case when qemu performs read on tun using file
operations.

Signed-off-by: Prashant Bhole <[email-masked]>
---
 drivers/net/tun.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 8e2fe0ad7955..0a9ac380c1b4 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2335,8 +2335,10 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
 			   struct iov_iter *to,
 			   int noblock, void *ptr)
 {
+	struct xdp_frame *frame;
 	ssize_t ret;
 	int err;
+	u32 act;
 
 	tun_debug(KERN_INFO, tun, "tun_do_read\n");
 
@@ -2350,6 +2352,15 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
 		ptr = tun_ring_recv(tfile, noblock, &err);
 		if (!ptr)
 			return err;
+
+		if (tun_is_xdp_frame(ptr)) {
+			frame = tun_ptr_to_xdp(ptr);
+			act = tun_do_xdp_tx(tun, tfile, frame);
+		} else {
+			act = tun_do_xdp_tx_generic(tun, ptr);
+		}
+		if (act != XDP_PASS)
+			return err;
 	}
 
 	if (tun_is_xdp_frame(ptr)) {
-- 
2.21.0