diff mbox series

[net,v2] vsock/virtio: fix packet delivery to tap device

Message ID 20240329161259.411751-1-marco.pinn95@gmail.com (mailing list archive)
State Accepted
Commit b32a09ea7c38849ff925489a6bf5bd8914bc45df
Delegated to: Netdev Maintainers
Headers show
Series [net,v2] vsock/virtio: fix packet delivery to tap device | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 943 this patch: 943
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 10 of 10 maintainers
netdev/build_clang success Errors and warnings before: 954 this patch: 954
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 954 this patch: 954
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 15 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-03-31--03-00 (tests: 953)

Commit Message

Marco Pinna March 29, 2024, 4:12 p.m. UTC
Commit 82dfb540aeb2 ("VSOCK: Add virtio vsock vsockmon hooks") added
virtio_transport_deliver_tap_pkt() for handing packets to the
vsockmon device. However, in virtio_transport_send_pkt_work(),
the function is called before actually sending the packet (i.e.
before placing it in the virtqueue with virtqueue_add_sgs() and checking
whether it returned successfully).
Queuing the packet in the virtqueue can fail even multiple times.
However, in virtio_transport_deliver_tap_pkt() we deliver the packet
to the monitoring tap interface only the first time we call it.
This certainly avoids seeing the same packet replicated multiple times
in the monitoring interface, but it can show the packet sent with the
wrong timestamp or even before we succeed to queue it in the virtqueue.

Move virtio_transport_deliver_tap_pkt() after calling virtqueue_add_sgs()
and making sure it returned successfully.

Fixes: 82dfb540aeb2 ("VSOCK: Add virtio vsock vsockmon hooks")
Cc: stable@vge.kernel.org
Signed-off-by: Marco Pinna <marco.pinn95@gmail.com>
---
 net/vmw_vsock/virtio_transport.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Stefano Garzarella March 29, 2024, 4:22 p.m. UTC | #1
On Fri, Mar 29, 2024 at 05:12:59PM +0100, Marco Pinna wrote:
>Commit 82dfb540aeb2 ("VSOCK: Add virtio vsock vsockmon hooks") added
>virtio_transport_deliver_tap_pkt() for handing packets to the
>vsockmon device. However, in virtio_transport_send_pkt_work(),
>the function is called before actually sending the packet (i.e.
>before placing it in the virtqueue with virtqueue_add_sgs() and checking
>whether it returned successfully).
>Queuing the packet in the virtqueue can fail even multiple times.
>However, in virtio_transport_deliver_tap_pkt() we deliver the packet
>to the monitoring tap interface only the first time we call it.
>This certainly avoids seeing the same packet replicated multiple times
>in the monitoring interface, but it can show the packet sent with the
>wrong timestamp or even before we succeed to queue it in the virtqueue.
>
>Move virtio_transport_deliver_tap_pkt() after calling virtqueue_add_sgs()
>and making sure it returned successfully.
>
>Fixes: 82dfb540aeb2 ("VSOCK: Add virtio vsock vsockmon hooks")
>Cc: stable@vge.kernel.org
>Signed-off-by: Marco Pinna <marco.pinn95@gmail.com>
>---
> net/vmw_vsock/virtio_transport.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

>
>diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
>index 1748268e0694..ee5d306a96d0 100644
>--- a/net/vmw_vsock/virtio_transport.c
>+++ b/net/vmw_vsock/virtio_transport.c
>@@ -120,7 +120,6 @@ virtio_transport_send_pkt_work(struct work_struct *work)
> 		if (!skb)
> 			break;
>
>-		virtio_transport_deliver_tap_pkt(skb);
> 		reply = virtio_vsock_skb_reply(skb);
> 		sgs = vsock->out_sgs;
> 		sg_init_one(sgs[out_sg], virtio_vsock_hdr(skb),
>@@ -170,6 +169,8 @@ virtio_transport_send_pkt_work(struct work_struct *work)
> 			break;
> 		}
>
>+		virtio_transport_deliver_tap_pkt(skb);
>+
> 		if (reply) {
> 			struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
> 			int val;
>-- 
>2.44.0
>
patchwork-bot+netdevbpf@kernel.org April 3, 2024, 1:10 a.m. UTC | #2
Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri, 29 Mar 2024 17:12:59 +0100 you wrote:
> Commit 82dfb540aeb2 ("VSOCK: Add virtio vsock vsockmon hooks") added
> virtio_transport_deliver_tap_pkt() for handing packets to the
> vsockmon device. However, in virtio_transport_send_pkt_work(),
> the function is called before actually sending the packet (i.e.
> before placing it in the virtqueue with virtqueue_add_sgs() and checking
> whether it returned successfully).
> Queuing the packet in the virtqueue can fail even multiple times.
> However, in virtio_transport_deliver_tap_pkt() we deliver the packet
> to the monitoring tap interface only the first time we call it.
> This certainly avoids seeing the same packet replicated multiple times
> in the monitoring interface, but it can show the packet sent with the
> wrong timestamp or even before we succeed to queue it in the virtqueue.
> 
> [...]

Here is the summary with links:
  - [net,v2] vsock/virtio: fix packet delivery to tap device
    https://git.kernel.org/netdev/net/c/b32a09ea7c38

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 1748268e0694..ee5d306a96d0 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -120,7 +120,6 @@  virtio_transport_send_pkt_work(struct work_struct *work)
 		if (!skb)
 			break;
 
-		virtio_transport_deliver_tap_pkt(skb);
 		reply = virtio_vsock_skb_reply(skb);
 		sgs = vsock->out_sgs;
 		sg_init_one(sgs[out_sg], virtio_vsock_hdr(skb),
@@ -170,6 +169,8 @@  virtio_transport_send_pkt_work(struct work_struct *work)
 			break;
 		}
 
+		virtio_transport_deliver_tap_pkt(skb);
+
 		if (reply) {
 			struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
 			int val;