VSOCK: Send reset control packet when socket is partially bound

If a server side socket is bound to an address, but not in the listening
state yet, incoming connection requests should receive a reset control
packet in response. However, the function used to send the reset
silently drops the reset packet if the sending socket isn't bound
to a remote address (as is the case for a bound socket not yet in
the listening state). This change fixes this by using the src
of the incoming packet as destination for the reset packet in
this case.

Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Reviewed-by: Adit Ranadive <aditr@vmware.com>
Reviewed-by: Vishnu Dasa <vdasa@vmware.com>
Signed-off-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index cb332adb84cdcadc006de6d7a8668111babd2f53..c361ce7824123da38ec613361a2ae5fa21197b7b 100644 (file)
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -263,6 +263,31 @@ vmci_transport_send_control_pkt_bh(struct sockaddr_vm *src,
                                                 false);
 }
 
+static int
+vmci_transport_alloc_send_control_pkt(struct sockaddr_vm *src,
+                                     struct sockaddr_vm *dst,
+                                     enum vmci_transport_packet_type type,
+                                     u64 size,
+                                     u64 mode,
+                                     struct vmci_transport_waiting_info *wait,
+                                     u16 proto,
+                                     struct vmci_handle handle)
+{
+       struct vmci_transport_packet *pkt;
+       int err;
+
+       pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
+       if (!pkt)
+               return -ENOMEM;
+
+       err = __vmci_transport_send_control_pkt(pkt, src, dst, type, size,
+                                               mode, wait, proto, handle,
+                                               true);
+       kfree(pkt);
+
+       return err;
+}
+
 static int
 vmci_transport_send_control_pkt(struct sock *sk,
                                enum vmci_transport_packet_type type,
@@ -272,9 +297,7 @@ vmci_transport_send_control_pkt(struct sock *sk,
                                u16 proto,
                                struct vmci_handle handle)
 {
-       struct vmci_transport_packet *pkt;
        struct vsock_sock *vsk;
-       int err;
 
        vsk = vsock_sk(sk);
 
@@ -284,17 +307,10 @@ vmci_transport_send_control_pkt(struct sock *sk,
        if (!vsock_addr_bound(&vsk->remote_addr))
                return -EINVAL;
 
-       pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
-       if (!pkt)
-               return -ENOMEM;
-
-       err = __vmci_transport_send_control_pkt(pkt, &vsk->local_addr,
-                                               &vsk->remote_addr, type, size,
-                                               mode, wait, proto, handle,
-                                               true);
-       kfree(pkt);
-
-       return err;
+       return vmci_transport_alloc_send_control_pkt(&vsk->local_addr,
+                                                    &vsk->remote_addr,
+                                                    type, size, mode,
+                                                    wait, proto, handle);
 }
 
 static int vmci_transport_send_reset_bh(struct sockaddr_vm *dst,
@@ -312,12 +328,29 @@ static int vmci_transport_send_reset_bh(struct sockaddr_vm *dst,
 static int vmci_transport_send_reset(struct sock *sk,
                                     struct vmci_transport_packet *pkt)
 {
+       struct sockaddr_vm *dst_ptr;
+       struct sockaddr_vm dst;
+       struct vsock_sock *vsk;
+
        if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST)
                return 0;
-       return vmci_transport_send_control_pkt(sk,
-                                       VMCI_TRANSPORT_PACKET_TYPE_RST,
-                                       0, 0, NULL, VSOCK_PROTO_INVALID,
-                                       VMCI_INVALID_HANDLE);
+
+       vsk = vsock_sk(sk);
+
+       if (!vsock_addr_bound(&vsk->local_addr))
+               return -EINVAL;
+
+       if (vsock_addr_bound(&vsk->remote_addr)) {
+               dst_ptr = &vsk->remote_addr;
+       } else {
+               vsock_addr_init(&dst, pkt->dg.src.context,
+                               pkt->src_port);
+               dst_ptr = &dst;
+       }
+       return vmci_transport_alloc_send_control_pkt(&vsk->local_addr, dst_ptr,
+                                            VMCI_TRANSPORT_PACKET_TYPE_RST,
+                                            0, 0, NULL, VSOCK_PROTO_INVALID,
+                                            VMCI_INVALID_HANDLE);
 }
 
 static int vmci_transport_send_negotiate(struct sock *sk, size_t size)