Hi Amery, Bobby
> From: Bobby Eshleman <bobby.eshleman@xxxxxxxxxxxxx>
>
> This commit drops the transport->dgram_dequeue callback and makes
> vsock_dgram_recvmsg() generic to all transports.
>
> To make this possible, two transport-level changes are introduced:
> - transport in the receiving path now stores the cid and port into
> the control buffer of an skb when populating an skb. The information
> later is used to initialize sockaddr_vm structure in recvmsg()
> without referencing vsk->transport.
> - transport implementations set the skb->data pointer to the beginning
> of the payload prior to adding the skb to the socket's receive queue.
> That is, they must use skb_pull() before enqueuing. This is an
> agreement between the transport and the socket layer that skb->data
> always points to the beginning of the payload (and not, for example,
> the packet header).
>
Like in the other patch, please use imperative in the commit message.
>
> Signed-off-by: Bobby Eshleman <bobby.eshleman@xxxxxxxxxxxxx>
> Signed-off-by: Amery Hung <amery.hung@xxxxxxxxxxxxx>
> ---
> drivers/vhost/vsock.c | 1 -
> include/linux/virtio_vsock.h | 5 ---
> include/net/af_vsock.h | 11 ++++-
> net/vmw_vsock/af_vsock.c | 42 +++++++++++++++++-
> net/vmw_vsock/hyperv_transport.c | 7 ---
> net/vmw_vsock/virtio_transport.c | 1 -
> net/vmw_vsock/virtio_transport_common.c | 9 ----
> net/vmw_vsock/vmci_transport.c | 59 +++----------------------
> net/vmw_vsock/vsock_loopback.c | 1 -
> 9 files changed, 55 insertions(+), 81 deletions(-)
>
> diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
> index ec20ecff85c7..97fffa914e66 100644
> --- a/drivers/vhost/vsock.c
> +++ b/drivers/vhost/vsock.c
> @@ -419,7 +419,6 @@ static struct virtio_transport vhost_transport = {
> .cancel_pkt = vhost_transport_cancel_pkt,
>
> .dgram_enqueue = virtio_transport_dgram_enqueue,
> - .dgram_dequeue = virtio_transport_dgram_dequeue,
> .dgram_bind = virtio_transport_dgram_bind,
> .dgram_allow = virtio_transport_dgram_allow,
>
> diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
> index c82089dee0c8..8b56b8a19ddd 100644
> --- a/include/linux/virtio_vsock.h
> +++ b/include/linux/virtio_vsock.h
> @@ -177,11 +177,6 @@ virtio_transport_stream_dequeue(struct vsock_sock *vsk,
> size_t len,
> int type);
> int
> -virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
> - struct msghdr *msg,
> - size_t len, int flags);
> -
> -int
> virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
> struct msghdr *msg,
> size_t len);
> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
> index 535701efc1e5..7aa1f5f2b1a5 100644
> --- a/include/net/af_vsock.h
> +++ b/include/net/af_vsock.h
> @@ -120,8 +120,6 @@ struct vsock_transport {
>
> /* DGRAM. */
> int (*dgram_bind)(struct vsock_sock *, struct sockaddr_vm *);
> - int (*dgram_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
> - size_t len, int flags);
> int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,
> struct msghdr *, size_t len);
> bool (*dgram_allow)(u32 cid, u32 port);
> @@ -219,6 +217,15 @@ void vsock_for_each_connected_socket(struct vsock_transport *transport,
> int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
> bool vsock_find_cid(unsigned int cid);
>
> +struct vsock_skb_cb {
> + unsigned int src_cid;
> + unsigned int src_port;
> +};
> +
> +static inline struct vsock_skb_cb *vsock_skb_cb(struct sk_buff *skb) {
> + return (struct vsock_skb_cb *)skb->cb;
> +};
> +
>
Running scripts/checkpatch.pl --strict --codespell on the patch shows this error:
ERROR: open brace '{' following function definitions go on the next line
#183: FILE: include/net/af_vsock.h:225:
+static inline struct vsock_skb_cb *vsock_skb_cb(struct sk_buff *skb) {
total: 1 errors, 0 warnings, 0 checks, 235 lines checked
>
> /**** TAP ****/
>
> struct vsock_tap {
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index 4b040285aa78..5e7d4d99ea2c 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/net/vmw_vsock/af_vsock.c
> @@ -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);
>
This if statement is always false!
>
> +
> + /* 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;
> +
nit: I'd remove this blank line.
> + 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);
> + 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);
>
> diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
> index e2157e387217..326dd41ee2d5 100644
> --- a/net/vmw_vsock/hyperv_transport.c
> +++ b/net/vmw_vsock/hyperv_transport.c
> @@ -556,12 +556,6 @@ static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr)
> return -EOPNOTSUPP;
> }
>
> -static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
> - size_t len, int flags)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> static int hvs_dgram_enqueue(struct vsock_sock *vsk,
> struct sockaddr_vm *remote, struct msghdr *msg,
> size_t dgram_len)
> @@ -833,7 +827,6 @@ static struct vsock_transport hvs_transport = {
> .shutdown = hvs_shutdown,
>
> .dgram_bind = hvs_dgram_bind,
> - .dgram_dequeue = hvs_dgram_dequeue,
> .dgram_enqueue = hvs_dgram_enqueue,
> .dgram_allow = hvs_dgram_allow,
>
> diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
> index 43d405298857..a8c97e95622a 100644
> --- a/net/vmw_vsock/virtio_transport.c
> +++ b/net/vmw_vsock/virtio_transport.c
> @@ -508,7 +508,6 @@ static struct virtio_transport virtio_transport = {
> .cancel_pkt = virtio_transport_cancel_pkt,
>
> .dgram_bind = virtio_transport_dgram_bind,
> - .dgram_dequeue = virtio_transport_dgram_dequeue,
> .dgram_enqueue = virtio_transport_dgram_enqueue,
> .dgram_allow = virtio_transport_dgram_allow,
>
> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> index 16ff976a86e3..4bf73d20c12a 100644
> --- a/net/vmw_vsock/virtio_transport_common.c
> +++ b/net/vmw_vsock/virtio_transport_common.c
> @@ -810,15 +810,6 @@ virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
> }
> EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue);
>
> -int
> -virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
> - struct msghdr *msg,
> - size_t len, int flags)
> -{
> - return -EOPNOTSUPP;
> -}
> -EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
> -
> s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
> {
> struct virtio_vsock_sock *vvs = vsk->trans;
> diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
> index b370070194fa..b39df3ed8c8d 100644
> --- 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);
> sk_receive_skb(sk, skb, 0);
>
> return VMCI_SUCCESS;
> @@ -1731,59 +1736,6 @@ static int vmci_transport_dgram_enqueue(
> return err - sizeof(*dg);
> }
>
> -static int vmci_transport_dgram_dequeue(struct vsock_sock *vsk,
> - struct msghdr *msg, size_t len,
> - int flags)
> -{
> - int err;
> - struct vmci_datagram *dg;
> - size_t payload_len;
> - struct sk_buff *skb;
> -
> - if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
> - return -EOPNOTSUPP;
> -
> - /* Retrieve the head sk_buff from the socket's receive queue. */
> - err = 0;
> - skb = skb_recv_datagram(&vsk->sk, flags, &err);
> - if (!skb)
> - return err;
> -
> - dg = (struct vmci_datagram *)skb->data;
> - if (!dg)
> - /* err is 0, meaning we read zero bytes. */
> - goto out;
> -
> - payload_len = dg->payload_size;
> - /* Ensure the sk_buff matches the payload size claimed in the packet. */
> - if (payload_len != skb->len - sizeof(*dg)) {
> - err = -EINVAL;
> - goto out;
> - }
> -
> - 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, sizeof(*dg), 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_addr_init(vm_addr, dg->src.context, dg->src.resource);
> - msg->msg_namelen = sizeof(*vm_addr);
> - }
> - err = payload_len;
> -
> -out:
> - skb_free_datagram(&vsk->sk, skb);
> - return err;
> -}
> -
> static bool vmci_transport_dgram_allow(u32 cid, u32 port)
> {
> if (cid == VMADDR_CID_HYPERVISOR) {
> @@ -2040,7 +1992,6 @@ static struct vsock_transport vmci_transport = {
> .release = vmci_transport_release,
> .connect = vmci_transport_connect,
> .dgram_bind = vmci_transport_dgram_bind,
> - .dgram_dequeue = vmci_transport_dgram_dequeue,
> .dgram_enqueue = vmci_transport_dgram_enqueue,
> .dgram_allow = vmci_transport_dgram_allow,
> .stream_dequeue = vmci_transport_stream_dequeue,
> diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
> index 6dea6119f5b2..11488887a5cc 100644
> --- a/net/vmw_vsock/vsock_loopback.c
> +++ b/net/vmw_vsock/vsock_loopback.c
> @@ -66,7 +66,6 @@ static struct virtio_transport loopback_transport = {
> .cancel_pkt = vsock_loopback_cancel_pkt,
>
> .dgram_bind = virtio_transport_dgram_bind,
> - .dgram_dequeue = virtio_transport_dgram_dequeue,
> .dgram_enqueue = virtio_transport_dgram_enqueue,
> .dgram_allow = virtio_transport_dgram_allow,
>
> --
> 2.20.1
>
>
Small changes :)
Rest LGTM!
Thanks,
Luigi
