[RFC PATCH 10/13] vsock: add multi-transports support

From: Stefano Garzarella
Date: Fri Sep 27 2019 - 07:28:37 EST

This patch adds the support of multiple transports in the
VSOCK core.

With the multi-transports support, we can use vsock with nested VMs
(using also different hypervisors) loading both guest->host and
host->guest transports at the same time.

Major changes:
- vsock core module can be loaded interdependently of the transports
- each 'struct virtio_transport' has a new feature fields
(H2G, G2H, DGRAM) to identify which directions the transport can
handle and if it's support DGRAM (only vmci)
- vsock_core_init() and vsock_core_exit() are renamed to
vsock_core_register() and vsock_core_unregister()
- each stream socket is assigned to a transport when the remote CID
is set (during the connect() or when we receive a connection request
on a listener socket).
The remote CID is used to decide which transport to use:
- remote CID > VMADDR_CID_HOST will use host->guest transport
- remote CID <= VMADDR_CID_HOST will use guest->host transport
- listener sockets are not bound to any transports since no transport
operations are done on it. In this way we can create a listener
socket, also if the transports are not loaded or with VMADDR_CID_ANY
to listen on all transports.
- DGRAM sockets are handled as before, since only the vmci_transport
provides this feature.

Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
RFC:
- I'd like to move MODULE_ALIAS_NETPROTO(PF_VSOCK) to af_vsock.c.
@Jorgen could this break the VMware products?
- DGRAM sockets are handled as before, I don't know if make sense work
on it now, or when another transport will support DGRAM. The big
issues here is that we cannot link 1-1 a socket to transport as
for stream sockets since DGRAM is not connection-oriented.
---
drivers/vhost/vsock.c | 6 +-
include/net/af_vsock.h | 15 +-
net/vmw_vsock/af_vsock.c | 240 ++++++++++++++++++------
net/vmw_vsock/hyperv_transport.c | 28 ++-
net/vmw_vsock/virtio_transport.c | 8 +-
net/vmw_vsock/virtio_transport_common.c | 28 ++-
net/vmw_vsock/vmci_transport.c | 31 ++-
7 files changed, 275 insertions(+), 81 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 6d7e4f022748..375af01a5b64 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -386,6 +386,8 @@ static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)

static struct virtio_transport vhost_transport = {
.transport = {
+ .features = VSOCK_TRANSPORT_F_H2G,
+
.get_local_cid = vhost_transport_get_local_cid,

.init = virtio_transport_do_socket_init,
@@ -831,7 +833,7 @@ static int __init vhost_vsock_init(void)
{
int ret;

- ret = vsock_core_init(&vhost_transport.transport);
+ ret = vsock_core_register(&vhost_transport.transport);
if (ret < 0)
return ret;
return misc_register(&vhost_vsock_misc);
@@ -840,7 +842,7 @@ static int __init vhost_vsock_init(void)
static void __exit vhost_vsock_exit(void)
{
misc_deregister(&vhost_vsock_misc);
- vsock_core_exit();
+ vsock_core_unregister(&vhost_transport.transport);
};

module_init(vhost_vsock_init);
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 86f8f463e01a..2a081d19e20d 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -94,7 +94,13 @@ struct vsock_transport_send_notify_data {
u64 data2; /* Transport-defined. */
};

+#define VSOCK_TRANSPORT_F_H2G 0x00000001
+#define VSOCK_TRANSPORT_F_G2H 0x00000002
+#define VSOCK_TRANSPORT_F_DGRAM 0x00000004
+
struct vsock_transport {
+ uint64_t features;
+
/* Initialize/tear-down socket. */
int (*init)(struct vsock_sock *, struct vsock_sock *);
void (*destruct)(struct vsock_sock *);
@@ -156,12 +162,8 @@ struct vsock_transport {

/**** CORE ****/

-int __vsock_core_init(const struct vsock_transport *t, struct module *owner);
-static inline int vsock_core_init(const struct vsock_transport *t)
-{
- return __vsock_core_init(t, THIS_MODULE);
-}
-void vsock_core_exit(void);
+int vsock_core_register(const struct vsock_transport *t);
+void vsock_core_unregister(const struct vsock_transport *t);

/* The transport may downcast this to access transport-specific functions */
const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk);
@@ -192,6 +194,7 @@ struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
struct sockaddr_vm *dst);
void vsock_remove_sock(struct vsock_sock *vsk);
void vsock_for_each_connected_socket(void (*fn)(struct sock *sk));
+int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);

/**** TAP ****/

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 95e6db21e7e1..c52203fe52c4 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -130,7 +130,12 @@ static struct proto vsock_proto = {
#define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)
#define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128

-static const struct vsock_transport *transport_single;
+/* Transport used for host->guest communication */
+static const struct vsock_transport *transport_h2g;
+/* Transport used for guest->host communication */
+static const struct vsock_transport *transport_g2h;
+/* Transport used for DGRAM communication */
+static const struct vsock_transport *transport_dgram;
static DEFINE_MUTEX(vsock_register_mutex);

/**** UTILS ****/
@@ -182,7 +187,7 @@ static int vsock_auto_bind(struct vsock_sock *vsk)
return __vsock_bind(sk, &local_addr);
}

-static int __init vsock_init_tables(void)
+static void vsock_init_tables(void)
{
int i;

@@ -191,7 +196,6 @@ static int __init vsock_init_tables(void)

for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
INIT_LIST_HEAD(&vsock_connected_table[i]);
- return 0;
}

static void __vsock_insert_bound(struct list_head *list,
@@ -376,6 +380,55 @@ void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
}
EXPORT_SYMBOL_GPL(vsock_enqueue_accept);

+/* Assign a transport to a socket and call the .init transport callback.
+ *
+ * Note: for stream socket this must be called when vsk->remote_addr is set
+ * (e.g. during the connect() or when a connection request on a listener
+ * socket is received).
+ * The vsk->remote_addr is used to decide which transport to use:
+ * - remote CID > VMADDR_CID_HOST will use host->guest transport
+ * - remote CID <= VMADDR_CID_HOST will use guest->host transport
+ */
+int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
+{
+ struct sock *sk = sk_vsock(vsk);
+ /* RFC-TODO: should vsk->transport be already assigned?
+ * How to handle?
+ */
+ WARN_ON(vsk->transport);
+
+ switch (sk->sk_type) {
+ case SOCK_DGRAM:
+ vsk->transport = transport_dgram;
+ break;
+ case SOCK_STREAM:
+ if (vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
+ vsk->transport = transport_h2g;
+ else
+ vsk->transport = transport_g2h;
+ break;
+ default:
+ return -ESOCKTNOSUPPORT;
+ }
+
+ if (!vsk->transport)
+ return -ENODEV;
+
+ return vsk->transport->init(vsk, psk);
+}
+EXPORT_SYMBOL_GPL(vsock_assign_transport);
+
+static bool vsock_find_cid(unsigned int cid)
+{
+ if (transport_g2h && cid == transport_g2h->get_local_cid())
+ return true;
+
+ if (transport_h2g && cid == VMADDR_CID_HOST)
+ return true;
+
+ return false;
+}
+
static struct sock *vsock_dequeue_accept(struct sock *listener)
{
struct vsock_sock *vlistener;
@@ -414,6 +467,9 @@ static int vsock_send_shutdown(struct sock *sk, int mode)
{
struct vsock_sock *vsk = vsock_sk(sk);

+ if (!vsk->transport)
+ return -ENODEV;
+
return vsk->transport->shutdown(vsk, mode);
}

@@ -530,7 +586,6 @@ static int __vsock_bind_dgram(struct vsock_sock *vsk,
static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
{
struct vsock_sock *vsk = vsock_sk(sk);
- u32 cid;
int retval;

/* First ensure this socket isn't already bound. */
@@ -540,10 +595,9 @@ static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
/* Now bind to the provided address or select appropriate values if
* none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY). Note that
* like AF_INET prevents binding to a non-local IP address (in most
- * cases), we only allow binding to the local CID.
+ * cases), we only allow binding to a local CID.
*/
- cid = vsk->transport->get_local_cid();
- if (addr->svm_cid != cid && addr->svm_cid != VMADDR_CID_ANY)
+ if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
return -EADDRNOTAVAIL;

switch (sk->sk_socket->type) {
@@ -592,7 +646,6 @@ struct sock *__vsock_create(struct net *net,
sk->sk_type = type;

vsk = vsock_sk(sk);
- vsk->transport = transport_single;
vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);

@@ -629,11 +682,6 @@ struct sock *__vsock_create(struct net *net,
vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
}

- if (vsk->transport->init(vsk, psk) < 0) {
- sk_free(sk);
- return NULL;
- }
-
return sk;
}
EXPORT_SYMBOL_GPL(__vsock_create);
@@ -648,7 +696,10 @@ static void __vsock_release(struct sock *sk)
vsk = vsock_sk(sk);
pending = NULL; /* Compiler warning. */

- vsk->transport->release(vsk);
+ if (vsk->transport)
+ vsk->transport->release(vsk);
+ else if (sk->sk_type == SOCK_STREAM)
+ vsock_remove_sock(vsk);

lock_sock(sk);
sock_orphan(sk);
@@ -672,7 +723,8 @@ static void vsock_sk_destruct(struct sock *sk)
{
struct vsock_sock *vsk = vsock_sk(sk);

- vsk->transport->destruct(vsk);
+ if (vsk->transport)
+ vsk->transport->destruct(vsk);

/* When clearing these addresses, there's no need to set the family and
* possibly register the address family with the kernel.
@@ -882,7 +934,7 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock,
mask |= EPOLLIN | EPOLLRDNORM;

/* If there is something in the queue then we can read. */
- if (transport->stream_is_active(vsk) &&
+ if (transport && transport->stream_is_active(vsk) &&
!(sk->sk_shutdown & RCV_SHUTDOWN)) {
bool data_ready_now = false;
int ret = transport->notify_poll_in(
@@ -1132,7 +1184,6 @@ static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
err = 0;
sk = sock->sk;
vsk = vsock_sk(sk);
- transport = vsk->transport;

lock_sock(sk);

@@ -1160,19 +1211,26 @@ static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
goto out;
}

+ /* Set the remote address that we are connecting to. */
+ memcpy(&vsk->remote_addr, remote_addr,
+ sizeof(vsk->remote_addr));
+
+ err = vsock_assign_transport(vsk, NULL);
+ if (err)
+ goto out;
+
+ transport = vsk->transport;
+
/* The hypervisor and well-known contexts do not have socket
* endpoints.
*/
- if (!transport->stream_allow(remote_addr->svm_cid,
+ if (!transport ||
+ !transport->stream_allow(remote_addr->svm_cid,
remote_addr->svm_port)) {
err = -ENETUNREACH;
goto out;
}

- /* Set the remote address that we are connecting to. */
- memcpy(&vsk->remote_addr, remote_addr,
- sizeof(vsk->remote_addr));
-
err = vsock_auto_bind(vsk);
if (err)
goto out;
@@ -1572,7 +1630,7 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
goto out;
}

- if (sk->sk_state != TCP_ESTABLISHED ||
+ if (!transport || sk->sk_state != TCP_ESTABLISHED ||
!vsock_addr_bound(&vsk->local_addr)) {
err = -ENOTCONN;
goto out;
@@ -1698,7 +1756,7 @@ vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,

lock_sock(sk);

- if (sk->sk_state != TCP_ESTABLISHED) {
+ if (!transport || sk->sk_state != TCP_ESTABLISHED) {
/* Recvmsg is supposed to return 0 if a peer performs an
* orderly shutdown. Differentiate between that case and when a
* peer has not connected or a local shutdown occured with the
@@ -1872,7 +1930,9 @@ static const struct proto_ops vsock_stream_ops = {
static int vsock_create(struct net *net, struct socket *sock,
int protocol, int kern)
{
+ struct vsock_sock *vsk;
struct sock *sk;
+ int ret;

if (!sock)
return -EINVAL;
@@ -1897,7 +1957,20 @@ static int vsock_create(struct net *net, struct socket *sock,
if (!sk)
return -ENOMEM;

- vsock_insert_unbound(vsock_sk(sk));
+ vsk = vsock_sk(sk);
+
+ /* RFC-TODO: for dgram we still support only one transport, and
+ * we assign it during the sock creation.
+ */
+ if (sock->type == SOCK_DGRAM) {
+ ret = vsock_assign_transport(vsk, NULL);
+ if (ret < 0) {
+ sock_put(sk);
+ return ret;
+ }
+ }
+
+ vsock_insert_unbound(vsk);

return 0;
}
@@ -1912,11 +1985,20 @@ static long vsock_dev_do_ioctl(struct file *filp,
unsigned int cmd, void __user *ptr)
{
u32 __user *p = ptr;
+ u32 cid = VMADDR_CID_ANY;
int retval = 0;

switch (cmd) {
case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
- if (put_user(transport_single->get_local_cid(), p) != 0)
+ /* To be compatible with the VMCI behavior, we prioritize the
+ * guest CID instead of well-know host CID (VMADDR_CID_HOST).
+ */
+ if (transport_g2h)
+ cid = transport_g2h->get_local_cid();
+ else if (transport_h2g)
+ cid = transport_h2g->get_local_cid();
+
+ if (put_user(cid, p) != 0)
retval = -EFAULT;
break;

@@ -1956,24 +2038,13 @@ static struct miscdevice vsock_device = {
.fops = &vsock_device_ops,
};

-int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
+static int __init vsock_init(void)
{
- int err = mutex_lock_interruptible(&vsock_register_mutex);
+ int err = 0;

- if (err)
- return err;
-
- if (transport_single) {
- err = -EBUSY;
- goto err_busy;
- }
-
- /* Transport must be the owner of the protocol so that it can't
- * unload while there are open sockets.
- */
- vsock_proto.owner = owner;
- transport_single = t;
+ vsock_init_tables();

+ vsock_proto.owner = THIS_MODULE;
vsock_device.minor = MISC_DYNAMIC_MINOR;
err = misc_register(&vsock_device);
if (err) {
@@ -1994,7 +2065,6 @@ int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
goto err_unregister_proto;
}

- mutex_unlock(&vsock_register_mutex);
return 0;

err_unregister_proto:
@@ -2002,28 +2072,15 @@ int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
err_deregister_misc:
misc_deregister(&vsock_device);
err_reset_transport:
- transport_single = NULL;
-err_busy:
- mutex_unlock(&vsock_register_mutex);
return err;
}
-EXPORT_SYMBOL_GPL(__vsock_core_init);

-void vsock_core_exit(void)
+static void __exit vsock_exit(void)
{
- mutex_lock(&vsock_register_mutex);
-
misc_deregister(&vsock_device);
sock_unregister(AF_VSOCK);
proto_unregister(&vsock_proto);
-
- /* We do not want the assignment below re-ordered. */
- mb();
- transport_single = NULL;
-
- mutex_unlock(&vsock_register_mutex);
}
-EXPORT_SYMBOL_GPL(vsock_core_exit);

const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
{
@@ -2034,12 +2091,77 @@ const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
}
EXPORT_SYMBOL_GPL(vsock_core_get_transport);

-static void __exit vsock_exit(void)
+int vsock_core_register(const struct vsock_transport *t)
{
- /* Do nothing. This function makes this module removable. */
+ const struct vsock_transport *t_h2g, *t_g2h, *t_dgram;
+ int err = mutex_lock_interruptible(&vsock_register_mutex);
+
+ if (err)
+ return err;
+
+ t_h2g = transport_h2g;
+ t_g2h = transport_g2h;
+ t_dgram = transport_dgram;
+
+ /* RFC-TODO: vmci transport offer both H2G and G2H features in the
+ * same transport. We are able to set the G2H feature only if we are
+ * in a VMware guest, but we are not able to do the same for the host.
+ */
+ if (t->features & VSOCK_TRANSPORT_F_H2G) {
+ if (t_h2g) {
+ err = -EBUSY;
+ goto err_busy;
+ }
+ t_h2g = t;
+ }
+
+ if (t->features & VSOCK_TRANSPORT_F_G2H) {
+ if (t_g2h) {
+ err = -EBUSY;
+ goto err_busy;
+ }
+ t_g2h = t;
+ }
+
+ if (t->features & VSOCK_TRANSPORT_F_DGRAM) {
+ if (t_dgram) {
+ err = -EBUSY;
+ goto err_busy;
+ }
+ t_dgram = t;
+ }
+
+ transport_h2g = t_h2g;
+ transport_g2h = t_g2h;
+ transport_dgram = t_dgram;
+
+err_busy:
+ mutex_unlock(&vsock_register_mutex);
+ return err;
+}
+EXPORT_SYMBOL_GPL(vsock_core_register);
+
+void vsock_core_unregister(const struct vsock_transport *t)
+{
+ mutex_lock(&vsock_register_mutex);
+
+ /* RFC-TODO: maybe we should check if there are open sockets
+ * assigned to that transport and avoid the unregistration
+ */
+ if (transport_h2g == t)
+ transport_h2g = NULL;
+
+ if (transport_g2h == t)
+ transport_g2h = NULL;
+
+ if (transport_dgram == t)
+ transport_dgram = NULL;
+
+ mutex_unlock(&vsock_register_mutex);
}
+EXPORT_SYMBOL_GPL(vsock_core_unregister);

-module_init(vsock_init_tables);
+module_init(vsock_init);
module_exit(vsock_exit);

MODULE_AUTHOR("VMware, Inc.");
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index 306310794522..94e6fc905a77 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -163,6 +163,8 @@ static const guid_t srv_id_template =
GUID_INIT(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58,
0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3);

+static bool hvs_check_transport(struct vsock_sock *vsk);
+
static bool is_valid_srv_id(const guid_t *id)
{
return !memcmp(&id->b[4], &srv_id_template.b[4], sizeof(guid_t) - 4);
@@ -366,6 +368,18 @@ static void hvs_open_connection(struct vmbus_channel *chan)

new->sk_state = TCP_SYN_SENT;
vnew = vsock_sk(new);
+
+ hvs_addr_init(&vnew->local_addr, if_type);
+ hvs_remote_addr_init(&vnew->remote_addr, &vnew->local_addr);
+
+ ret = vsock_assign_transport(vnew, vsock_sk(sk));
+ /* Transport assigned (looking at remote_addr) must be the
+ * same where we received the request.
+ */
+ if (ret || !hvs_check_transport(vnew)) {
+ sock_put(new);
+ goto out;
+ }
hvs_new = vnew->trans;
hvs_new->chan = chan;
} else {
@@ -429,9 +443,6 @@ static void hvs_open_connection(struct vmbus_channel *chan)
new->sk_state = TCP_ESTABLISHED;
sk->sk_ack_backlog++;

- hvs_addr_init(&vnew->local_addr, if_type);
- hvs_remote_addr_init(&vnew->remote_addr, &vnew->local_addr);
-
hvs_new->vm_srv_id = *if_type;
hvs_new->host_srv_id = *if_instance;

@@ -845,6 +856,8 @@ int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written,
}

static struct vsock_transport hvs_transport = {
+ .features = VSOCK_TRANSPORT_F_G2H,
+
.get_local_cid = hvs_get_local_cid,

.init = hvs_sock_init,
@@ -879,6 +892,11 @@ static struct vsock_transport hvs_transport = {

};

+static bool hvs_check_transport(struct vsock_sock *vsk)
+{
+ return vsk->transport == &hvs_transport;
+}
+
static int hvs_probe(struct hv_device *hdev,
const struct hv_vmbus_device_id *dev_id)
{
@@ -927,7 +945,7 @@ static int __init hvs_init(void)
if (ret != 0)
return ret;

- ret = vsock_core_init(&hvs_transport);
+ ret = vsock_core_register(&hvs_transport);
if (ret) {
vmbus_driver_unregister(&hvs_drv);
return ret;
@@ -938,7 +956,7 @@ static int __init hvs_init(void)

static void __exit hvs_exit(void)
{
- vsock_core_exit();
+ vsock_core_unregister(&hvs_transport);
vmbus_driver_unregister(&hvs_drv);
}

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index fb1fc7760e8c..0ff037ef7f8e 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -462,6 +462,8 @@ static void virtio_vsock_rx_done(struct virtqueue *vq)

static struct virtio_transport virtio_transport = {
.transport = {
+ .features = VSOCK_TRANSPORT_F_G2H,
+
.get_local_cid = virtio_transport_get_local_cid,

.init = virtio_transport_do_socket_init,
@@ -770,7 +772,7 @@ static int __init virtio_vsock_init(void)
if (!virtio_vsock_workqueue)
return -ENOMEM;

- ret = vsock_core_init(&virtio_transport.transport);
+ ret = vsock_core_register(&virtio_transport.transport);
if (ret)
goto out_wq;

@@ -781,7 +783,7 @@ static int __init virtio_vsock_init(void)
return 0;

out_vci:
- vsock_core_exit();
+ vsock_core_unregister(&virtio_transport.transport);
out_wq:
destroy_workqueue(virtio_vsock_workqueue);
return ret;
@@ -790,7 +792,7 @@ static int __init virtio_vsock_init(void)
static void __exit virtio_vsock_exit(void)
{
unregister_virtio_driver(&virtio_vsock_driver);
- vsock_core_exit();
+ vsock_core_unregister(&virtio_transport.transport);
destroy_workqueue(virtio_vsock_workqueue);
}

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index bac9e7430a2e..ebb4701310a4 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -400,7 +400,7 @@ int virtio_transport_do_socket_init(struct vsock_sock *vsk,

vsk->trans = vvs;
vvs->vsk = vsk;
- if (psk) {
+ if (psk && psk->trans) {
struct virtio_vsock_sock *ptrans = psk->trans;

vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
@@ -927,11 +927,13 @@ virtio_transport_send_response(struct vsock_sock *vsk,

/* Handle server socket */
static int
-virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt)
+virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,
+ struct virtio_transport *t)
{
struct vsock_sock *vsk = vsock_sk(sk);
struct vsock_sock *vchild;
struct sock *child;
+ int ret;

if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
virtio_transport_reset(vsk, pkt);
@@ -962,6 +964,17 @@ virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt)
vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
le32_to_cpu(pkt->hdr.src_port));

+ ret = vsock_assign_transport(vchild, vsk);
+ /* Transport assigned (looking at remote_addr) must be the same
+ * where we received the request.
+ */
+ if (ret || vchild->transport != &t->transport) {
+ release_sock(child);
+ virtio_transport_reset(vsk, pkt);
+ sock_put(child);
+ return ret;
+ }
+
vsock_insert_connected(vchild);
vsock_enqueue_accept(sk, child);
virtio_transport_send_response(vchild, pkt);
@@ -979,6 +992,14 @@ static bool virtio_transport_space_update(struct sock *sk,
struct virtio_vsock_sock *vvs = vsk->trans;
bool space_available;

+ /* Listener sockets are not associated with any transport, so we are
+ * not able to take the state to see if there is space available in the
+ * remote peer, but since they are only used to receive requests, we
+ * can assume that there is always space available in the other peer.
+ */
+ if (!vvs)
+ return true;
+
/* buf_alloc and fwd_cnt is always included in the hdr */
spin_lock_bh(&vvs->tx_lock);
vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
@@ -1044,7 +1065,7 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,

switch (sk->sk_state) {
case TCP_LISTEN:
- virtio_transport_recv_listen(sk, pkt);
+ virtio_transport_recv_listen(sk, pkt, t);
virtio_transport_free_pkt(pkt);
break;
case TCP_SYN_SENT:
@@ -1062,6 +1083,7 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
virtio_transport_free_pkt(pkt);
break;
}
+
release_sock(sk);

/* Release refcnt obtained when we fetched this socket out of the
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index 8290d37b6587..52e63952d0d4 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -57,6 +57,7 @@ static bool vmci_transport_old_proto_override(bool *old_pkt_proto);
static u16 vmci_transport_new_proto_supported_versions(void);
static bool vmci_transport_proto_to_notify_struct(struct sock *sk, u16 *proto,
bool old_pkt_proto);
+static bool vmci_check_transport(struct vsock_sock *vsk);

struct vmci_transport_recv_pkt_info {
struct work_struct work;
@@ -1018,6 +1019,15 @@ static int vmci_transport_recv_listen(struct sock *sk,
vsock_addr_init(&vpending->remote_addr, pkt->dg.src.context,
pkt->src_port);

+ err = vsock_assign_transport(vpending, vsock_sk(sk));
+ /* Transport assigned (looking at remote_addr) must be the same
+ * where we received the request.
+ */
+ if (err || !vmci_check_transport(vpending)) {
+ sock_put(pending);
+ return err;
+ }
+
/* If the proposed size fits within our min/max, accept it. Otherwise
* propose our own size.
*/
@@ -2009,7 +2019,8 @@ static u32 vmci_transport_get_local_cid(void)
return vmci_get_context_id();
}

-static const struct vsock_transport vmci_transport = {
+static struct vsock_transport vmci_transport = {
+ .features = VSOCK_TRANSPORT_F_DGRAM | VSOCK_TRANSPORT_F_H2G,
.init = vmci_transport_socket_init,
.destruct = vmci_transport_destruct,
.release = vmci_transport_release,
@@ -2039,10 +2050,24 @@ static const struct vsock_transport vmci_transport = {
.get_local_cid = vmci_transport_get_local_cid,
};

+static bool vmci_check_transport(struct vsock_sock *vsk)
+{
+ return vsk->transport == &vmci_transport;
+}
+
static int __init vmci_transport_init(void)
{
+ int cid;
int err;

+ cid = vmci_get_context_id();
+
+ if (cid == VMCI_INVALID_ID)
+ return -EINVAL;
+
+ if (cid != VMCI_HOST_CONTEXT_ID)
+ vmci_transport.features |= VSOCK_TRANSPORT_F_G2H;
+
/* Create the datagram handle that we will use to send and receive all
* VSocket control messages for this context.
*/
@@ -2066,7 +2091,7 @@ static int __init vmci_transport_init(void)
goto err_destroy_stream_handle;
}

- err = vsock_core_init(&vmci_transport);
+ err = vsock_core_register(&vmci_transport);
if (err < 0)
goto err_unsubscribe;

@@ -2097,7 +2122,7 @@ static void __exit vmci_transport_exit(void)
vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
}

- vsock_core_exit();
+ vsock_core_unregister(&vmci_transport);
}
module_exit(vmci_transport_exit);

--
2.21.0