[PATCH net-next v2 11/15] vsock: add multi-transports support

From: Stefano Garzarella
Date: Thu Nov 14 2019 - 04:59:11 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 regardless of the transports
- vsock_core_init() and vsock_core_exit() are renamed to
vsock_core_register() and vsock_core_unregister()
- vsock_core_register() has a feature parameter (H2G, G2H, DGRAM)
to identify which directions the transport can handle and if it's
support DGRAM (only vmci)
- 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 guest->host transport;
- remote CID == local_cid (guest->host transport) will use guest->host
transport for loopback (host->guest transports don't support loopback);
- remote CID > VMADDR_CID_HOST will use host->guest 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>
---
v1 -> v2:
- vmci_transport: sent reset when vsock_assign_transport() fails [Jorgen]
- fixed loopback in the guests, checking if the remote_addr is the same of
transport_g2h->get_local_cid()
- virtio_transport_common: updated space available while creating the new
child socket during a connection request
---
drivers/vhost/vsock.c | 5 +-
include/net/af_vsock.h | 18 +-
net/vmw_vsock/af_vsock.c | 243 ++++++++++++++++++------
net/vmw_vsock/hyperv_transport.c | 26 ++-
net/vmw_vsock/virtio_transport.c | 7 +-
net/vmw_vsock/virtio_transport_common.c | 63 ++++--
net/vmw_vsock/vmci_transport.c | 32 +++-
7 files changed, 297 insertions(+), 97 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 6d7e4f022748..b235f4bbe8ea 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -831,7 +831,8 @@ static int __init vhost_vsock_init(void)
{
int ret;

- ret = vsock_core_init(&vhost_transport.transport);
+ ret = vsock_core_register(&vhost_transport.transport,
+ VSOCK_TRANSPORT_F_H2G);
if (ret < 0)
return ret;
return misc_register(&vhost_vsock_misc);
@@ -840,7 +841,7 @@ 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 fa1570dc9f5c..cf5c3691251b 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -91,6 +91,14 @@ struct vsock_transport_send_notify_data {
u64 data2; /* Transport-defined. */
};

+/* Transport features flags */
+/* Transport provides host->guest communication */
+#define VSOCK_TRANSPORT_F_H2G 0x00000001
+/* Transport provides guest->host communication */
+#define VSOCK_TRANSPORT_F_G2H 0x00000002
+/* Transport provides DGRAM communication */
+#define VSOCK_TRANSPORT_F_DGRAM 0x00000004
+
struct vsock_transport {
/* Initialize/tear-down socket. */
int (*init)(struct vsock_sock *, struct vsock_sock *);
@@ -154,12 +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, int features);
+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);
@@ -190,6 +194,8 @@ 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);
+bool vsock_find_cid(unsigned int cid);

/**** TAP ****/

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 8985d9d417f0..5357714b6104 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 +380,68 @@ 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 guest->host transport;
+ * - remote CID == local_cid (guest->host transport) will use guest->host
+ * transport for loopback (host->guest transports don't support loopback);
+ * - remote CID > VMADDR_CID_HOST will use host->guest transport;
+ */
+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;
+
+ switch (sk->sk_type) {
+ case SOCK_DGRAM:
+ new_transport = transport_dgram;
+ break;
+ case SOCK_STREAM:
+ if (remote_cid <= VMADDR_CID_HOST ||
+ (transport_g2h &&
+ remote_cid == transport_g2h->get_local_cid()))
+ new_transport = transport_g2h;
+ else
+ new_transport = transport_h2g;
+ break;
+ default:
+ return -ESOCKTNOSUPPORT;
+ }
+
+ if (vsk->transport) {
+ if (vsk->transport == new_transport)
+ return 0;
+
+ vsk->transport->release(vsk);
+ vsk->transport->destruct(vsk);
+ }
+
+ if (!new_transport)
+ return -ENODEV;
+
+ vsk->transport = new_transport;
+
+ return vsk->transport->init(vsk, psk);
+}
+EXPORT_SYMBOL_GPL(vsock_assign_transport);
+
+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;
+}
+EXPORT_SYMBOL_GPL(vsock_find_cid);
+
static struct sock *vsock_dequeue_accept(struct sock *listener)
{
struct vsock_sock *vlistener;
@@ -414,6 +480,9 @@ 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 +599,6 @@ 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 +608,9 @@ 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 +659,6 @@ static 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 +695,6 @@ static 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;
}

@@ -649,7 +710,10 @@ static void __vsock_release(struct sock *sk, int level)
/* The release call is supposed to use lock_sock_nested()
* rather than lock_sock(), if a sock lock should be acquired.
*/
- vsk->transport->release(vsk);
+ if (vsk->transport)
+ vsk->transport->release(vsk);
+ else if (sk->sk_type == SOCK_STREAM)
+ vsock_remove_sock(vsk);

/* When "level" is SINGLE_DEPTH_NESTING, use the nested
* version to avoid the warning "possible recursive locking
@@ -677,7 +741,8 @@ 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.
@@ -894,7 +959,7 @@ 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(
@@ -1144,7 +1209,6 @@ 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);

@@ -1172,19 +1236,26 @@ 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;
@@ -1584,7 +1655,7 @@ 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;
@@ -1710,7 +1781,7 @@ 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
@@ -1884,7 +1955,9 @@ 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;
@@ -1909,7 +1982,17 @@ static int vsock_create(struct net *net, struct socket *sock,
if (!sk)
return -ENOMEM;

- vsock_insert_unbound(vsock_sk(sk));
+ vsk = vsock_sk(sk);
+
+ 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;
}
@@ -1924,11 +2007,20 @@ 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;

@@ -1968,24 +2060,13 @@ 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) {
@@ -2006,7 +2087,6 @@ 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:
@@ -2014,28 +2094,15 @@ 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)
{
@@ -2043,12 +2110,70 @@ 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, int features)
+{
+ 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;
+
+ if (features & VSOCK_TRANSPORT_F_H2G) {
+ if (t_h2g) {
+ err = -EBUSY;
+ goto err_busy;
+ }
+ t_h2g = t;
+ }
+
+ if (features & VSOCK_TRANSPORT_F_G2H) {
+ if (t_g2h) {
+ err = -EBUSY;
+ goto err_busy;
+ }
+ t_g2h = t;
+ }
+
+ if (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)
{
- /* Do nothing. This function makes this module removable. */
+ mutex_lock(&vsock_register_mutex);
+
+ 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 22b608805a91..1c9e65d7d94d 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -165,6 +165,8 @@ 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);
@@ -367,6 +369,18 @@ 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 {
@@ -430,9 +444,6 @@ static void hvs_open_connection(struct vmbus_channel *chan)
new->sk_state = TCP_ESTABLISHED;
sk_acceptq_added(sk);

- 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;

@@ -880,6 +891,11 @@ 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)
{
@@ -928,7 +944,7 @@ static int __init hvs_init(void)
if (ret != 0)
return ret;

- ret = vsock_core_init(&hvs_transport);
+ ret = vsock_core_register(&hvs_transport, VSOCK_TRANSPORT_F_G2H);
if (ret) {
vmbus_driver_unregister(&hvs_drv);
return ret;
@@ -939,7 +955,7 @@ 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..83ad85050384 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -770,7 +770,8 @@ 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,
+ VSOCK_TRANSPORT_F_G2H);
if (ret)
goto out_wq;

@@ -781,7 +782,7 @@ 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 +791,7 @@ 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 b7b1a98e478e..e5ea29c6bca7 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -453,7 +453,7 @@ 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;
@@ -986,13 +986,39 @@ virtio_transport_send_response(struct vsock_sock *vsk,
return virtio_transport_send_pkt_info(vsk, &info);
}

+static bool virtio_transport_space_update(struct sock *sk,
+ struct virtio_vsock_pkt *pkt)
+{
+ struct vsock_sock *vsk = vsock_sk(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);
+ vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
+ space_available = virtio_transport_has_space(vsk);
+ spin_unlock_bh(&vvs->tx_lock);
+ return space_available;
+}
+
/* 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);
@@ -1022,6 +1048,20 @@ 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;
+ }
+
+ if (virtio_transport_space_update(child, pkt))
+ child->sk_write_space(child);
+
vsock_insert_connected(vchild);
vsock_enqueue_accept(sk, child);
virtio_transport_send_response(vchild, pkt);
@@ -1032,22 +1072,6 @@ virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt)
return 0;
}

-static bool virtio_transport_space_update(struct sock *sk,
- struct virtio_vsock_pkt *pkt)
-{
- struct vsock_sock *vsk = vsock_sk(sk);
- struct virtio_vsock_sock *vvs = vsk->trans;
- bool space_available;
-
- /* 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);
- vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
- space_available = virtio_transport_has_space(vsk);
- spin_unlock_bh(&vvs->tx_lock);
- return space_available;
-}
-
/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
* lock.
*/
@@ -1104,7 +1128,7 @@ 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:
@@ -1122,6 +1146,7 @@ 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 b6c8c9cc8d72..86030ecb53dd 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;
@@ -1017,6 +1018,16 @@ 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)) {
+ vmci_transport_send_reset(sk, pkt);
+ sock_put(pending);
+ return err;
+ }
+
/* If the proposed size fits within our min/max, accept it. Otherwise
* propose our own size.
*/
@@ -2008,7 +2019,7 @@ 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 = {
.init = vmci_transport_socket_init,
.destruct = vmci_transport_destruct,
.release = vmci_transport_release,
@@ -2038,10 +2049,25 @@ 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 features = VSOCK_TRANSPORT_F_DGRAM | VSOCK_TRANSPORT_F_H2G;
+ int cid;
int err;

+ cid = vmci_get_context_id();
+
+ if (cid == VMCI_INVALID_ID)
+ return -EINVAL;
+
+ if (cid != VMCI_HOST_CONTEXT_ID)
+ features |= VSOCK_TRANSPORT_F_G2H;
+
/* Create the datagram handle that we will use to send and receive all
* VSocket control messages for this context.
*/
@@ -2065,7 +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, features);
if (err < 0)
goto err_unsubscribe;

@@ -2096,7 +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