> @@ -1273,11 +1273,15 @@ static int vsock_dgram_connect(struct socket *sock,
> int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
> size_t len, int flags)
> {
> + struct vsock_skb_cb *vsock_cb;
> #ifdef CONFIG_BPF_SYSCALL
> const struct proto *prot;
> #endif
> struct vsock_sock *vsk;
> + struct sk_buff *skb;
> + size_t payload_len;
> struct sock *sk;
> + int err;
>
> sk = sock->sk;
> vsk = vsock_sk(sk);
> @@ -1288,7 +1292,43 @@ int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
> return prot->recvmsg(sk, msg, len, flags, NULL);
> #endif
>
> - return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
> + if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
> + return -EOPNOTSUPP;
> +
> + if (unlikely(flags & MSG_ERRQUEUE))
> + return sock_recv_errqueue(sk, msg, len, SOL_VSOCK, 0);
> +
> + /* Retrieve the head sk_buff from the socket's receive queue. */
> + err = 0;
> + skb = skb_recv_datagram(sk_vsock(vsk), flags, &err);
> + if (!skb)
> + return err;
> +
> + payload_len = skb->len;
> +
> + if (payload_len > len) {
> + payload_len = len;
> + msg->msg_flags |= MSG_TRUNC;
> + }
> +
> + /* Place the datagram payload in the user's iovec. */
> + err = skb_copy_datagram_msg(skb, 0, msg, payload_len);
> + if (err)
> + goto out;
> +
> + if (msg->msg_name) {
> + /* Provide the address of the sender. */
> + DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
> +
> + vsock_cb = vsock_skb_cb(skb);
May be we can declare 'vsock_cb' here ? Reducing its scope.
> + vsock_addr_init(vm_addr, vsock_cb->src_cid, vsock_cb->src_port);
> + msg->msg_namelen = sizeof(*vm_addr);
> + }
> + err = payload_len;
> +
> +out:
> + skb_free_datagram(&vsk->sk, skb);
> + return err;
> }
> EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
>
> --- a/net/vmw_vsock/vmci_transport.c
> +++ b/net/vmw_vsock/vmci_transport.c
> @@ -610,6 +610,7 @@ vmci_transport_datagram_create_hnd(u32 resource_id,
>
> static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
> {
> + struct vsock_skb_cb *vsock_cb;
> struct sock *sk;
> size_t size;
> struct sk_buff *skb;
> @@ -637,10 +638,14 @@ static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
> if (!skb)
> return VMCI_ERROR_NO_MEM;
>
> + vsock_cb = vsock_skb_cb(skb);
> + vsock_cb->src_cid = dg->src.context;
> + vsock_cb->src_port = dg->src.resource;
> /* sk_receive_skb() will do a sock_put(), so hold here. */
> sock_hold(sk);
> skb_put(skb, size);
> memcpy(skb->data, dg, size);
> + skb_pull(skb, VMCI_DG_HEADERSIZE);
Small suggestion: here we do:
1) skb_put(skb, size of entire datagram)
2) memcpy(entire datagram)
3) skb_pull(VMCI_DG_HEADERSIZE)
If we provide only data to the upper layer, we can do:
1) skb_put(dg->payload_size)
2) memcpy(dg->payload_size)
Also (I'm no expert in VMCI), i guess using dg->payload_size is safer
to know number of data bytes, instead of using VMCI_DG_HEADERSIZE.
WDYT?
> sk_receive_skb(sk, skb, 0);
>
> return VMCI_SUCCESS;
> @@ -1731,59 +1736,6 @@ static int vmci_transport_dgram_enqueue(
> return err - sizeof(*dg);
> }
>
Thanks
