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Commit 5db4d286 authored by Stefano Stabellini's avatar Stefano Stabellini Committed by Boris Ostrovsky
Browse files

xen/pvcalls: implement connect command 



Allocate a socket. Keep track of socket <-> ring mappings with a new data
structure, called sock_mapping. Implement the connect command by calling
inet_stream_connect, and mapping the new indexes page and data ring.
Allocate a workqueue and a work_struct, called ioworker, to perform
reads and writes to the socket.

When an active socket is closed (sk_state_change), set in_error to
-ENOTCONN and notify the other end, as specified by the protocol.

sk_data_ready and pvcalls_back_ioworker will be implemented later.

[ boris: fixed whitespaces ]

Signed-off-by: default avatarStefano Stabellini <stefano@aporeto.com>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
CC: boris.ostrovsky@oracle.com
CC: jgross@suse.com
Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
parent fb029875

drivers/xen/pvcalls-back.c

+179 −0
Original line number Diff line number Diff line
@@ -54,6 +54,39 @@ struct pvcalls_fedata { 
	struct semaphore socket_lock;

};



struct pvcalls_ioworker {

	struct work_struct register_work;

	struct workqueue_struct *wq;

};



struct sock_mapping {

	struct list_head list;

	struct pvcalls_fedata *fedata;

	struct socket *sock;

	uint64_t id;

	grant_ref_t ref;

	struct pvcalls_data_intf *ring;

	void *bytes;

	struct pvcalls_data data;

	uint32_t ring_order;

	int irq;

	atomic_t read;

	atomic_t write;

	atomic_t io;

	atomic_t release;

	void (*saved_data_ready)(struct sock *sk);

	struct pvcalls_ioworker ioworker;

};



static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map);

static int pvcalls_back_release_active(struct xenbus_device *dev,

				       struct pvcalls_fedata *fedata,

				       struct sock_mapping *map);



static void pvcalls_back_ioworker(struct work_struct *work)

{

}



static int pvcalls_back_socket(struct xenbus_device *dev,

		struct xen_pvcalls_request *req)

{
@@ -82,8 +115,149 @@ static int pvcalls_back_socket(struct xenbus_device *dev, 
	return 0;

}



static void pvcalls_sk_state_change(struct sock *sock)

{

	struct sock_mapping *map = sock->sk_user_data;

	struct pvcalls_data_intf *intf;



	if (map == NULL)

		return;



	intf = map->ring;

	intf->in_error = -ENOTCONN;

	notify_remote_via_irq(map->irq);

}



static void pvcalls_sk_data_ready(struct sock *sock)

{

}



static struct sock_mapping *pvcalls_new_active_socket(

		struct pvcalls_fedata *fedata,

		uint64_t id,

		grant_ref_t ref,

		uint32_t evtchn,

		struct socket *sock)

{

	int ret;

	struct sock_mapping *map;

	void *page;



	map = kzalloc(sizeof(*map), GFP_KERNEL);

	if (map == NULL)

		return NULL;



	map->fedata = fedata;

	map->sock = sock;

	map->id = id;

	map->ref = ref;



	ret = xenbus_map_ring_valloc(fedata->dev, &ref, 1, &page);

	if (ret < 0)

		goto out;

	map->ring = page;

	map->ring_order = map->ring->ring_order;

	/* first read the order, then map the data ring */

	virt_rmb();

	if (map->ring_order > MAX_RING_ORDER) {

		pr_warn("%s frontend requested ring_order %u, which is > MAX (%u)\n",

				__func__, map->ring_order, MAX_RING_ORDER);

		goto out;

	}

	ret = xenbus_map_ring_valloc(fedata->dev, map->ring->ref,

				     (1 << map->ring_order), &page);

	if (ret < 0)

		goto out;

	map->bytes = page;



	ret = bind_interdomain_evtchn_to_irqhandler(fedata->dev->otherend_id,

						    evtchn,

						    pvcalls_back_conn_event,

						    0,

						    "pvcalls-backend",

						    map);

	if (ret < 0)

		goto out;

	map->irq = ret;



	map->data.in = map->bytes;

	map->data.out = map->bytes + XEN_FLEX_RING_SIZE(map->ring_order);



	map->ioworker.wq = alloc_workqueue("pvcalls_io", WQ_UNBOUND, 1);

	if (!map->ioworker.wq)

		goto out;

	atomic_set(&map->io, 1);

	INIT_WORK(&map->ioworker.register_work,	pvcalls_back_ioworker);



	down(&fedata->socket_lock);

	list_add_tail(&map->list, &fedata->socket_mappings);

	up(&fedata->socket_lock);



	write_lock_bh(&map->sock->sk->sk_callback_lock);

	map->saved_data_ready = map->sock->sk->sk_data_ready;

	map->sock->sk->sk_user_data = map;

	map->sock->sk->sk_data_ready = pvcalls_sk_data_ready;

	map->sock->sk->sk_state_change = pvcalls_sk_state_change;

	write_unlock_bh(&map->sock->sk->sk_callback_lock);



	return map;

out:

	down(&fedata->socket_lock);

	list_del(&map->list);

	pvcalls_back_release_active(fedata->dev, fedata, map);

	up(&fedata->socket_lock);

	return NULL;

}



static int pvcalls_back_connect(struct xenbus_device *dev,

				struct xen_pvcalls_request *req)

{

	struct pvcalls_fedata *fedata;

	int ret = -EINVAL;

	struct socket *sock;

	struct sock_mapping *map;

	struct xen_pvcalls_response *rsp;

	struct sockaddr *sa = (struct sockaddr *)&req->u.connect.addr;



	fedata = dev_get_drvdata(&dev->dev);



	if (req->u.connect.len < sizeof(sa->sa_family) ||

	    req->u.connect.len > sizeof(req->u.connect.addr) ||

	    sa->sa_family != AF_INET)

		goto out;



	ret = sock_create(AF_INET, SOCK_STREAM, 0, &sock);

	if (ret < 0)

		goto out;

	ret = inet_stream_connect(sock, sa, req->u.connect.len, 0);

	if (ret < 0) {

		sock_release(sock);

		goto out;

	}



	map = pvcalls_new_active_socket(fedata,

					req->u.connect.id,

					req->u.connect.ref,

					req->u.connect.evtchn,

					sock);

	if (!map) {

		ret = -EFAULT;

		sock_release(map->sock);

	}



out:

	rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++);

	rsp->req_id = req->req_id;

	rsp->cmd = req->cmd;

	rsp->u.connect.id = req->u.connect.id;

	rsp->ret = ret;



	return 0;

}



static int pvcalls_back_release_active(struct xenbus_device *dev,

				       struct pvcalls_fedata *fedata,

				       struct sock_mapping *map)

{

	return 0;

}
@@ -206,6 +380,11 @@ static irqreturn_t pvcalls_back_event(int irq, void *dev_id) 
	return IRQ_HANDLED;

}



static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map)

{

	return IRQ_HANDLED;

}



static int backend_connect(struct xenbus_device *dev)

{

	int err, evtchn;