[PATCH v3 06/13] xen/pvcalls: implement bind command

[Stefano Stabellini]

Send PVCALLS_BIND to the backend. Introduce a new structure, part of
struct sock_mapping, to store information specific to passive sockets.

Introduce a status field to keep track of the status of the passive
socket.

Signed-off-by: Stefano Stabellini <stefano@xxxxxxxxxxx>
CC: boris.ostrovsky@xxxxxxxxxx
CC: jgross@xxxxxxxx
---
 drivers/xen/pvcalls-front.c | 59 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/xen/pvcalls-front.h |  3 +++
 2 files changed, 62 insertions(+)

diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 379b8fb..5ccef34 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -59,6 +59,13 @@ struct sock_mapping {
 
 			wait_queue_head_t inflight_conn_req;
 		} active;
+		struct {
+		/* Socket status */
+#define PVCALLS_STATUS_UNINITALIZED  0
+#define PVCALLS_STATUS_BIND          1
+#define PVCALLS_STATUS_LISTEN        2
+			uint8_t status;
+		} passive;
 	};
 };
 
@@ -308,6 +315,58 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
 	return ret;
 }
 
+int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
+{
+	struct pvcalls_bedata *bedata;
+	struct sock_mapping *map = NULL;
+	struct xen_pvcalls_request *req;
+	int notify, req_id, ret;
+
+	if (!pvcalls_front_dev)
+		return -ENOTCONN;
+	if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
+		return -ENOTSUPP;
+	bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
+
+	map = (struct sock_mapping *) READ_ONCE(sock->sk->sk_send_head);
+	if (map == NULL)
+		return -EINVAL;
+
+	spin_lock(&bedata->pvcallss_lock);
+	ret = get_request(bedata, &req_id);
+	if (ret < 0) {
+		spin_unlock(&bedata->pvcallss_lock);
+		return ret;
+	}
+	req = RING_GET_REQUEST(&bedata->ring, req_id);
+	req->req_id = req_id;
+	map->sock = sock;
+	req->cmd = PVCALLS_BIND;
+	req->u.bind.id = (uint64_t) map;
+	memcpy(req->u.bind.addr, addr, sizeof(*addr));
+	req->u.bind.len = addr_len;
+
+	init_waitqueue_head(&map->passive.inflight_accept_req);
+
+	map->active_socket = false;
+
+	bedata->ring.req_prod_pvt++;
+	RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
+	spin_unlock(&bedata->pvcallss_lock);
+	if (notify)
+		notify_remote_via_irq(bedata->irq);
+
+	wait_event(bedata->inflight_req,
+		   READ_ONCE(bedata->rsp[req_id].req_id) == req_id);
+
+	map->passive.status = PVCALLS_STATUS_BIND;
+	ret = bedata->rsp[req_id].ret;
+	/* read ret, then set this rsp slot to be reused */
+	smp_mb();
+	WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID);
+	return 0;
+}
+
 static const struct xenbus_device_id pvcalls_front_ids[] = {
 	{ "pvcalls" },
 	{ "" }
diff --git a/drivers/xen/pvcalls-front.h b/drivers/xen/pvcalls-front.h
index 63b0417..8b0a274 100644
--- a/drivers/xen/pvcalls-front.h
+++ b/drivers/xen/pvcalls-front.h
@@ -6,5 +6,8 @@
 int pvcalls_front_socket(struct socket *sock);
 int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
 			  int addr_len, int flags);
+int pvcalls_front_bind(struct socket *sock,
+		       struct sockaddr *addr,
+		       int addr_len);
 
 #endif
-- 
1.9.1