[RFC PATCH 4/5] vsock: seqpacket_allow adapts to multi-devices

[Xuewei Niu]

Adds a new argument, named "src_cid", to let them know which `virtio_vsock`
to be selected.

Signed-off-by: Xuewei Niu <niuxuewei....@antgroup.com>
---
 include/net/af_vsock.h           |  2 +-
 net/vmw_vsock/af_vsock.c         | 15 +++++++++++++--
 net/vmw_vsock/virtio_transport.c |  4 ++--
 net/vmw_vsock/vsock_loopback.c   |  4 ++--
 4 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 0151296a0bc5..25f7dc3d602d 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -143,7 +143,7 @@ struct vsock_transport {
                                     int flags);
        int (*seqpacket_enqueue)(struct vsock_sock *vsk, struct msghdr *msg,
                                 size_t len);
-       bool (*seqpacket_allow)(u32 remote_cid);
+       bool (*seqpacket_allow)(u32 src_cid, u32 remote_cid);
        u32 (*seqpacket_has_data)(struct vsock_sock *vsk);
 
        /* Notification. */
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index da06ddc940cd..3b34be802bf2 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -470,10 +470,12 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct 
vsock_sock *psk)
 {
        const struct vsock_transport *new_transport;
        struct sock *sk = sk_vsock(vsk);
-       unsigned int remote_cid = vsk->remote_addr.svm_cid;
+       unsigned int src_cid, remote_cid;
        __u8 remote_flags;
        int ret;
 
+       remote_cid = vsk->remote_addr.svm_cid;
+
        /* If the packet is coming with the source and destination CIDs higher
         * than VMADDR_CID_HOST, then a vsock channel where all the packets are
         * forwarded to the host should be established. Then the host will
@@ -527,8 +529,17 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct 
vsock_sock *psk)
                return -ENODEV;
 
        if (sk->sk_type == SOCK_SEQPACKET) {
+               if (vsk->local_addr.svm_cid == VMADDR_CID_ANY) {
+                       if (new_transport->get_default_cid)
+                               src_cid = new_transport->get_default_cid();
+                       else
+                               src_cid = new_transport->get_local_cid();
+               } else {
+                       src_cid = vsk->local_addr.svm_cid;
+               }
+
                if (!new_transport->seqpacket_allow ||
-                   !new_transport->seqpacket_allow(remote_cid)) {
+                   !new_transport->seqpacket_allow(src_cid, remote_cid)) {
                        module_put(new_transport->module);
                        return -ESOCKTNOSUPPORT;
                }
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 998b22e5ce36..0bddcbd906a2 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -615,14 +615,14 @@ static struct virtio_transport virtio_transport = {
        .can_msgzerocopy = virtio_transport_can_msgzerocopy,
 };
 
-static bool virtio_transport_seqpacket_allow(u32 remote_cid)
+static bool virtio_transport_seqpacket_allow(u32 src_cid, u32 remote_cid)
 {
        struct virtio_vsock *vsock;
        bool seqpacket_allow;
 
        seqpacket_allow = false;
        rcu_read_lock();
-       vsock = rcu_dereference(the_virtio_vsock);
+       vsock = virtio_transport_get_virtio_vsock(src_cid);
        if (vsock)
                seqpacket_allow = vsock->seqpacket_allow;
        rcu_read_unlock();
diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
index 6dea6119f5b2..b94358f5bb2c 100644
--- a/net/vmw_vsock/vsock_loopback.c
+++ b/net/vmw_vsock/vsock_loopback.c
@@ -46,7 +46,7 @@ static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
        return 0;
 }
 
-static bool vsock_loopback_seqpacket_allow(u32 remote_cid);
+static bool vsock_loopback_seqpacket_allow(u32 src_cid, u32 remote_cid);
 static bool vsock_loopback_msgzerocopy_allow(void)
 {
        return true;
@@ -104,7 +104,7 @@ static struct virtio_transport loopback_transport = {
        .send_pkt = vsock_loopback_send_pkt,
 };
 
-static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
+static bool vsock_loopback_seqpacket_allow(u32 src_cid, u32 remote_cid)
 {
        return true;
 }
-- 
2.34.1