[PATCH net-next v1 2/3] virtio_transport_common: Set sibling VMs flag on the receive path

[Andra Paraschiv <andraprs@amazon.com>]

The vsock flag can be set during the connect() setup logic, when
initializing the vsock address data structure variable. Then the vsock
transport is assigned, also considering this flag.

The vsock transport is also assigned on the (listen) receive path. The
flag needs to be set considering the use case.

Set the vsock flag of the remote address to the one targeted for sibling
VMs communication if the following conditions are met:

* The source CID of the packet is higher than VMADDR_CID_HOST.
* The destination CID of the packet is higher than VMADDR_CID_HOST.

Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
---
 net/vmw_vsock/virtio_transport_common.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 5956939eebb78..871c84e0916b1 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1062,6 +1062,14 @@ virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,
 	vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
 			le32_to_cpu(pkt->hdr.src_port));
 
+	/* If the packet is coming with the source and destination CIDs higher
+	 * than VMADDR_CID_HOST, then a vsock channel should be established for
+	 * sibling VMs communication.
+	 */
+	if (vchild->local_addr.svm_cid > VMADDR_CID_HOST &&
+	    vchild->remote_addr.svm_cid > VMADDR_CID_HOST)
+		vchild->remote_addr.svm_flag = VMADDR_FLAG_SIBLING_VMS_COMMUNICATION;
+
 	ret = vsock_assign_transport(vchild, vsk);
 	/* Transport assigned (looking at remote_addr) must be the same
 	 * where we received the request.
-- 
2.20.1 (Apple Git-117)




Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.