[PATCH net-next 04/14] vsock: add 'transport' member in the struct vsock_sock

Stefano Garzarella
2019-10-23T09:57:26Z

As a preparation to support multiple transports, this patch adds
the 'transport' member at the 'struct vsock_sock'.
This new field is initialized during the creation in the
__vsock_create() function.

This patch also renames the global 'transport' pointer to
'transport_single', since for now we're only supporting a single
transport registered at run-time.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
include/net/af_vsock.h | 1 +
net/vmw_vsock/af_vsock.c | 56 +++++++++++++++++++++++++++-------------
2 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index c660402b10f2..a5e1e134261d 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -27,6 +27,7 @@ extern spinlock_t vsock_table_lock;
struct vsock_sock {
/* sk must be the first member. */
struct sock sk;
+ const struct vsock_transport *transport;
struct sockaddr_vm local_addr;
struct sockaddr_vm remote_addr;
/* Links for the global tables of bound and connected sockets. */
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 2f2582fb7fdd..c3a14f853eb0 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -126,7 +126,7 @@ static struct proto vsock_proto = {
*/
#define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)

-static const struct vsock_transport *transport;
+static const struct vsock_transport *transport_single;
static DEFINE_MUTEX(vsock_register_mutex);

/**** UTILS ****/
@@ -408,7 +408,9 @@ static bool vsock_is_pending(struct sock *sk)

static int vsock_send_shutdown(struct sock *sk, int mode)
{
- return transport->shutdown(vsock_sk(sk), mode);
+ struct vsock_sock *vsk = vsock_sk(sk);
+
+ return vsk->transport->shutdown(vsk, mode);
}

static void vsock_pending_work(struct work_struct *work)
@@ -518,7 +520,7 @@ static int __vsock_bind_stream(struct vsock_sock *vsk,
static int __vsock_bind_dgram(struct vsock_sock *vsk,
struct sockaddr_vm *addr)
{
- return transport->dgram_bind(vsk, addr);
+ return vsk->transport->dgram_bind(vsk, addr);
}

static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
@@ -536,7 +538,7 @@ static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
* like AF_INET prevents binding to a non-local IP address (in most
* cases), we only allow binding to the local CID.
*/
- cid = transport->get_local_cid();
+ cid = vsk->transport->get_local_cid();
if (addr->svm_cid != cid && addr->svm_cid != VMADDR_CID_ANY)
return -EADDRNOTAVAIL;

@@ -586,6 +588,7 @@ 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);

@@ -616,7 +619,7 @@ struct sock *__vsock_create(struct net *net,
vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
}

- if (transport->init(vsk, psk) < 0) {
+ if (vsk->transport->init(vsk, psk) < 0) {
sk_free(sk);
return NULL;
}
@@ -641,7 +644,7 @@ 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.
*/
- transport->release(vsk);
+ vsk->transport->release(vsk);

/* When "level" is SINGLE_DEPTH_NESTING, use the nested
* version to avoid the warning "possible recursive locking
@@ -670,7 +673,7 @@ static void vsock_sk_destruct(struct sock *sk)
{
struct vsock_sock *vsk = vsock_sk(sk);

- transport->destruct(vsk);
+ 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.
@@ -694,13 +697,13 @@ static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)

s64 vsock_stream_has_data(struct vsock_sock *vsk)
{
- return transport->stream_has_data(vsk);
+ return vsk->transport->stream_has_data(vsk);
}
EXPORT_SYMBOL_GPL(vsock_stream_has_data);

s64 vsock_stream_has_space(struct vsock_sock *vsk)
{
- return transport->stream_has_space(vsk);
+ return vsk->transport->stream_has_space(vsk);
}
EXPORT_SYMBOL_GPL(vsock_stream_has_space);

@@ -869,6 +872,7 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock,
mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;

} else if (sock->type == SOCK_STREAM) {
+ const struct vsock_transport *transport = vsk->transport;
lock_sock(sk);

/* Listening sockets that have connections in their accept
@@ -944,6 +948,7 @@ static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
struct sock *sk;
struct vsock_sock *vsk;
struct sockaddr_vm *remote_addr;
+ const struct vsock_transport *transport;

if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
@@ -952,6 +957,7 @@ static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
err = 0;
sk = sock->sk;
vsk = vsock_sk(sk);
+ transport = vsk->transport;

lock_sock(sk);

@@ -1036,8 +1042,8 @@ static int vsock_dgram_connect(struct socket *sock,
if (err)
goto out;

- if (!transport->dgram_allow(remote_addr->svm_cid,
- remote_addr->svm_port)) {
+ if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
+ remote_addr->svm_port)) {
err = -EINVAL;
goto out;
}
@@ -1053,7 +1059,9 @@ static int vsock_dgram_connect(struct socket *sock,
static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
size_t len, int flags)
{
- return transport->dgram_dequeue(vsock_sk(sock->sk), msg, len, flags);
+ struct vsock_sock *vsk = vsock_sk(sock->sk);
+
+ return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
}

static const struct proto_ops vsock_dgram_ops = {
@@ -1079,6 +1087,8 @@ static const struct proto_ops vsock_dgram_ops = {

static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
{
+ const struct vsock_transport *transport = vsk->transport;
+
if (!transport->cancel_pkt)
return -EOPNOTSUPP;

@@ -1115,6 +1125,7 @@ static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
int err;
struct sock *sk;
struct vsock_sock *vsk;
+ const struct vsock_transport *transport;
struct sockaddr_vm *remote_addr;
long timeout;
DEFINE_WAIT(wait);
@@ -1122,6 +1133,7 @@ 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);

@@ -1365,6 +1377,7 @@ static int vsock_stream_setsockopt(struct socket *sock,
int err;
struct sock *sk;
struct vsock_sock *vsk;
+ const struct vsock_transport *transport;
u64 val;

if (level != AF_VSOCK)
@@ -1385,6 +1398,7 @@ static int vsock_stream_setsockopt(struct socket *sock,
err = 0;
sk = sock->sk;
vsk = vsock_sk(sk);
+ transport = vsk->transport;

lock_sock(sk);

@@ -1442,6 +1456,7 @@ static int vsock_stream_getsockopt(struct socket *sock,
int len;
struct sock *sk;
struct vsock_sock *vsk;
+ const struct vsock_transport *transport;
u64 val;

if (level != AF_VSOCK)
@@ -1465,6 +1480,7 @@ static int vsock_stream_getsockopt(struct socket *sock,
err = 0;
sk = sock->sk;
vsk = vsock_sk(sk);
+ transport = vsk->transport;

switch (optname) {
case SO_VM_SOCKETS_BUFFER_SIZE:
@@ -1509,6 +1525,7 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
{
struct sock *sk;
struct vsock_sock *vsk;
+ const struct vsock_transport *transport;
ssize_t total_written;
long timeout;
int err;
@@ -1517,6 +1534,7 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,

sk = sock->sk;
vsk = vsock_sk(sk);
+ transport = vsk->transport;
total_written = 0;
err = 0;

@@ -1648,6 +1666,7 @@ vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
{
struct sock *sk;
struct vsock_sock *vsk;
+ const struct vsock_transport *transport;
int err;
size_t target;
ssize_t copied;
@@ -1658,6 +1677,7 @@ vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,

sk = sock->sk;
vsk = vsock_sk(sk);
+ transport = vsk->transport;
err = 0;

lock_sock(sk);
@@ -1872,7 +1892,7 @@ static long vsock_dev_do_ioctl(struct file *filp,

switch (cmd) {
case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
- if (put_user(transport->get_local_cid(), p) != 0)
+ if (put_user(transport_single->get_local_cid(), p) != 0)
retval = -EFAULT;
break;

@@ -1919,7 +1939,7 @@ int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
if (err)
return err;

- if (transport) {
+ if (transport_single) {
err = -EBUSY;
goto err_busy;
}
@@ -1928,7 +1948,7 @@ int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
* unload while there are open sockets.
*/
vsock_proto.owner = owner;
- transport = t;
+ transport_single = t;

vsock_device.minor = MISC_DYNAMIC_MINOR;
err = misc_register(&vsock_device);
@@ -1958,7 +1978,7 @@ int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
err_deregister_misc:
misc_deregister(&vsock_device);
err_reset_transport:
- transport = NULL;
+ transport_single = NULL;
err_busy:
mutex_unlock(&vsock_register_mutex);
return err;
@@ -1975,7 +1995,7 @@ void vsock_core_exit(void)

/* We do not want the assignment below re-ordered. */
mb();
- transport = NULL;
+ transport_single = NULL;

mutex_unlock(&vsock_register_mutex);
}
@@ -1986,7 +2006,7 @@ const struct vsock_transport *vsock_core_get_transport(void)
/* vsock_register_mutex not taken since only the transport uses this
* function and only while registered.
*/
- return transport;
+ return transport_single;
}
EXPORT_SYMBOL_GPL(vsock_core_get_transport);

--
2.21.0