On Wed, Jul 10, 2024 at 09:25:50PM GMT, Amery Hung wrote:
From: Bobby Eshleman <bobby.eshleman@xxxxxxxxxxxxx>
This commit adds the common datagram receive functionality for virtio
transports. It does not add the vhost/virtio users of that
functionality.
This functionality includes:
- changes to the virtio_transport_recv_pkt() path for finding the
bound socket receiver for incoming packets
- virtio_transport_recv_pkt() saves the source cid and port to the
control buffer for recvmsg() to initialize sockaddr_vm structure
when using datagram
Signed-off-by: Bobby Eshleman <bobby.eshleman@xxxxxxxxxxxxx>
Signed-off-by: Amery Hung <amery.hung@xxxxxxxxxxxxx>
---
net/vmw_vsock/virtio_transport_common.c | 79 +++++++++++++++++++++----
1 file changed, 66 insertions(+), 13 deletions(-)
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 46cd1807f8e3..a571b575fde9 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -235,7 +235,9 @@ EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
static u16 virtio_transport_get_type(struct sock *sk)
{
- if (sk->sk_type == SOCK_STREAM)
+ if (sk->sk_type == SOCK_DGRAM)
+ return VIRTIO_VSOCK_TYPE_DGRAM;
+ else if (sk->sk_type == SOCK_STREAM)
return VIRTIO_VSOCK_TYPE_STREAM;
else
return VIRTIO_VSOCK_TYPE_SEQPACKET;
@@ -1422,6 +1424,33 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
kfree_skb(skb);
}
+static void
+virtio_transport_dgram_kfree_skb(struct sk_buff *skb, int err)
+{
+ if (err == -ENOMEM)
+ kfree_skb_reason(skb, SKB_DROP_REASON_SOCKET_RCVBUFF);
+ else if (err == -ENOBUFS)
+ kfree_skb_reason(skb, SKB_DROP_REASON_PROTO_MEM);
+ else
+ kfree_skb(skb);
+}
+
+/* This function takes ownership of the skb.
+ *
+ * It either places the skb on the sk_receive_queue or frees it.
+ */
+static void
+virtio_transport_recv_dgram(struct sock *sk, struct sk_buff *skb)
+{
+ int err;
+
+ err = sock_queue_rcv_skb(sk, skb);
+ if (err) {
+ virtio_transport_dgram_kfree_skb(skb, err);
+ return;
+ }
+}
+
static int
virtio_transport_recv_connected(struct sock *sk,
struct sk_buff *skb)
@@ -1591,7 +1620,8 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
static bool virtio_transport_valid_type(u16 type)
{
return (type == VIRTIO_VSOCK_TYPE_STREAM) ||
- (type == VIRTIO_VSOCK_TYPE_SEQPACKET);
+ (type == VIRTIO_VSOCK_TYPE_SEQPACKET) ||
+ (type == VIRTIO_VSOCK_TYPE_DGRAM);
}
/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
@@ -1601,44 +1631,57 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
struct sk_buff *skb)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
+ struct vsock_skb_cb *vsock_cb;
This can be defined in the block where it's used.
struct sockaddr_vm src, dst;
struct vsock_sock *vsk;
struct sock *sk;
bool space_available;
+ u16 type;
vsock_addr_init(&src, le64_to_cpu(hdr->src_cid),
le32_to_cpu(hdr->src_port));
vsock_addr_init(&dst, le64_to_cpu(hdr->dst_cid),
le32_to_cpu(hdr->dst_port));
+ type = le16_to_cpu(hdr->type);
+
trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
dst.svm_cid, dst.svm_port,
le32_to_cpu(hdr->len),
- le16_to_cpu(hdr->type),
+ type,
le16_to_cpu(hdr->op),
le32_to_cpu(hdr->flags),
le32_to_cpu(hdr->buf_alloc),
le32_to_cpu(hdr->fwd_cnt));
- if (!virtio_transport_valid_type(le16_to_cpu(hdr->type))) {
+ if (!virtio_transport_valid_type(type)) {
(void)virtio_transport_reset_no_sock(t, skb);
goto free_pkt;
}
- /* The socket must be in connected or bound table
- * otherwise send reset back
+ /* For stream/seqpacket, the socket must be in connected or bound table
+ * otherwise send reset back.
+ *
+ * For datagrams, no reset is sent back.
*/
sk = vsock_find_connected_socket(&src, &dst);
if (!sk) {
- sk = vsock_find_bound_socket(&dst);
- if (!sk) {
- (void)virtio_transport_reset_no_sock(t, skb);
- goto free_pkt;
+ if (type == VIRTIO_VSOCK_TYPE_DGRAM) {
+ sk = vsock_find_bound_dgram_socket(&dst);
+ if (!sk)
+ goto free_pkt;
+ } else {
+ sk = vsock_find_bound_socket(&dst);
+ if (!sk) {
+ (void)virtio_transport_reset_no_sock(t, skb);
+ goto free_pkt;
+ }
}
}
- if (virtio_transport_get_type(sk) != le16_to_cpu(hdr->type)) {
- (void)virtio_transport_reset_no_sock(t, skb);
+ if (virtio_transport_get_type(sk) != type) {
+ if (type != VIRTIO_VSOCK_TYPE_DGRAM)
+ (void)virtio_transport_reset_no_sock(t, skb);
sock_put(sk);
goto free_pkt;
}
@@ -1654,12 +1697,21 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
/* Check if sk has been closed before lock_sock */
if (sock_flag(sk, SOCK_DONE)) {
- (void)virtio_transport_reset_no_sock(t, skb);
+ if (type != VIRTIO_VSOCK_TYPE_DGRAM)
+ (void)virtio_transport_reset_no_sock(t, skb);
release_sock(sk);
sock_put(sk);
goto free_pkt;
}
+ if (sk->sk_type == SOCK_DGRAM) {
+ vsock_cb = vsock_skb_cb(skb);
+ vsock_cb->src_cid = src.svm_cid;
+ vsock_cb->src_port = src.svm_port;
+ virtio_transport_recv_dgram(sk, skb);
What about adding an API that transports can use to hide this?
I mean something that hide vsock_cb creation and queue packet in the
socket receive queue. I'd also not expose vsock_skb_cb in an header, but
I'd handle it internally in af_vsock.c. So I'd just expose API to
queue/dequeue them.
Also why VMCI is using sk_receive_skb(), while we are using
sock_queue_rcv_skb()?
Thanks,
Stefano
+ goto out;
+ }
+
space_available = virtio_transport_space_update(sk, skb);
/* Update CID in case it has changed after a transport reset event */
@@ -1691,6 +1743,7 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
break;
}
+out:
release_sock(sk);
/* Release refcnt obtained when we fetched this socket out of the
--
2.20.1
