linux/drivers/misc/vmw_vmci/vmci_datagram.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * VMware VMCI Driver
 *
 * Copyright (C) 2012 VMware, Inc. All rights reserved.
 */

#include <linux/vmw_vmci_defs.h>
#include <linux/vmw_vmci_api.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/bug.h>

#include "vmci_datagram.h"
#include "vmci_resource.h"
#include "vmci_context.h"
#include "vmci_driver.h"
#include "vmci_event.h"
#include "vmci_route.h"

/*
 * struct datagram_entry describes the datagram entity. It is used for datagram
 * entities created only on the host.
 */
struct datagram_entry { … };

struct delayed_datagram_info { … };

/* Number of in-flight host->host datagrams */
static atomic_t delayed_dg_host_queue_size = …;

/*
 * Create a datagram entry given a handle pointer.
 */
static int dg_create_handle(u32 resource_id,
			    u32 flags,
			    u32 priv_flags,
			    vmci_datagram_recv_cb recv_cb,
			    void *client_data, struct vmci_handle *out_handle)
{ … }

/*
 * Internal utility function with the same purpose as
 * vmci_datagram_get_priv_flags that also takes a context_id.
 */
static int vmci_datagram_get_priv_flags(u32 context_id,
					struct vmci_handle handle,
					u32 *priv_flags)
{ … }

/*
 * Calls the specified callback in a delayed context.
 */
static void dg_delayed_dispatch(struct work_struct *work)
{ … }

/*
 * Dispatch datagram as a host, to the host, or other vm context. This
 * function cannot dispatch to hypervisor context handlers. This should
 * have been handled before we get here by vmci_datagram_dispatch.
 * Returns number of bytes sent on success, error code otherwise.
 */
static int dg_dispatch_as_host(u32 context_id, struct vmci_datagram *dg)
{ … }

/*
 * Dispatch datagram as a guest, down through the VMX and potentially to
 * the host.
 * Returns number of bytes sent on success, error code otherwise.
 */
static int dg_dispatch_as_guest(struct vmci_datagram *dg)
{ … }

/*
 * Dispatch datagram.  This will determine the routing for the datagram
 * and dispatch it accordingly.
 * Returns number of bytes sent on success, error code otherwise.
 */
int vmci_datagram_dispatch(u32 context_id,
			   struct vmci_datagram *dg, bool from_guest)
{ … }

/*
 * Invoke the handler for the given datagram.  This is intended to be
 * called only when acting as a guest and receiving a datagram from the
 * virtual device.
 */
int vmci_datagram_invoke_guest_handler(struct vmci_datagram *dg)
{ … }

/*
 * vmci_datagram_create_handle_priv() - Create host context datagram endpoint
 * @resource_id:        The resource ID.
 * @flags:      Datagram Flags.
 * @priv_flags: Privilege Flags.
 * @recv_cb:    Callback when receiving datagrams.
 * @client_data:        Pointer for a datagram_entry struct
 * @out_handle: vmci_handle that is populated as a result of this function.
 *
 * Creates a host context datagram endpoint and returns a handle to it.
 */
int vmci_datagram_create_handle_priv(u32 resource_id,
				     u32 flags,
				     u32 priv_flags,
				     vmci_datagram_recv_cb recv_cb,
				     void *client_data,
				     struct vmci_handle *out_handle)
{ … }
EXPORT_SYMBOL_GPL(…);

/*
 * vmci_datagram_create_handle() - Create host context datagram endpoint
 * @resource_id:        Resource ID.
 * @flags:      Datagram Flags.
 * @recv_cb:    Callback when receiving datagrams.
 * @client_ata: Pointer for a datagram_entry struct
 * @out_handle: vmci_handle that is populated as a result of this function.
 *
 * Creates a host context datagram endpoint and returns a handle to
 * it.  Same as vmci_datagram_create_handle_priv without the priviledge
 * flags argument.
 */
int vmci_datagram_create_handle(u32 resource_id,
				u32 flags,
				vmci_datagram_recv_cb recv_cb,
				void *client_data,
				struct vmci_handle *out_handle)
{ … }
EXPORT_SYMBOL_GPL(…);

/*
 * vmci_datagram_destroy_handle() - Destroys datagram handle
 * @handle:     vmci_handle to be destroyed and reaped.
 *
 * Use this function to destroy any datagram handles created by
 * vmci_datagram_create_handle{,Priv} functions.
 */
int vmci_datagram_destroy_handle(struct vmci_handle handle)
{ … }
EXPORT_SYMBOL_GPL(…);

/*
 * vmci_datagram_send() - Send a datagram
 * @msg:        The datagram to send.
 *
 * Sends the provided datagram on its merry way.
 */
int vmci_datagram_send(struct vmci_datagram *msg)
{ … }
EXPORT_SYMBOL_GPL(…);