nuttx/net/netlink/netlink.h

285 lines
9.7 KiB
C

/****************************************************************************
* net/netlink/netlink.h
*
* Copyright (C) 2018-2019 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __NET_NETLINK_NETLINK_H
#define __NET_NETLINK_NETLINK_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <queue.h>
#include <semaphore.h>
#include <netpacket/netlink.h>
#include "devif/devif.h"
#include "socket/socket.h"
#ifdef CONFIG_NET_NETLINK
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define NETLINK_NO_WAITER ((pid_t)-1)
/****************************************************************************
* Public Type Definitions
****************************************************************************/
/* Netlink uses a two step, request-get, referenced by a user managed
* sequence number. This means that the requested data must be buffered
* until it is gotten by the client. This structure holds that buffered
* data.
*
* REVISIT: There really should be a time stamp on this so that we can
* someday weed out un-claimed responses.
*/
struct netlink_response_s
{
sq_entry_t flink;
FAR struct nlmsghdr msg;
/* Message-specific data may follow */
};
#define SIZEOF_NETLINK_RESPONSE_S(n) (sizeof(struct netlink_response_s) + (n) - 1)
/* This "connection" structure describes the underlying state of the socket. */
struct netlink_conn_s
{
/* Common prologue of all connection structures. */
dq_entry_t node; /* Supports a doubly linked list */
/* This is a list of NetLink connection callbacks. Each callback
* represents a thread that is stalled, waiting for a device-specific
* event.
*/
FAR struct devif_callback_s *list; /* NetLink callbacks */
/* NetLink-specific content follows */
uint32_t pid; /* Port ID (if bound) */
uint32_t groups; /* Multicast groups mask (if bound) */
uint8_t crefs; /* Reference counts on this instance */
uint8_t protocol; /* See NETLINK_* definitions */
/* Threads waiting for a response */
pid_t waiter[CONFIG_NETLINK_MAXPENDING];
/* Queued response data */
sq_queue_t resplist; /* Singly linked list of responses*/
};
/****************************************************************************
* Public Data
****************************************************************************/
#ifdef __cplusplus
# define EXTERN extern "C"
extern "C"
{
#else
# define EXTERN extern
#endif
EXTERN const struct sock_intf_s g_netlink_sockif;
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
struct sockaddr_nl; /* Forward reference */
/****************************************************************************
* Name: netlink_initialize()
*
* Description:
* Initialize the NetLink connection structures. Called once and only
* from the networking layer.
*
****************************************************************************/
void netlink_initialize(void);
/****************************************************************************
* Name: netlink_alloc()
*
* Description:
* Allocate a new, uninitialized NetLink connection structure. This is
* normally something done by the implementation of the socket() API
*
****************************************************************************/
FAR struct netlink_conn_s *netlink_alloc(void);
/****************************************************************************
* Name: netlink_free()
*
* Description:
* Free a NetLink connection structure that is no longer in use. This should
* be done by the implementation of close().
*
****************************************************************************/
void netlink_free(FAR struct netlink_conn_s *conn);
/****************************************************************************
* Name: netlink_nextconn()
*
* Description:
* Traverse the list of allocated NetLink connections
*
* Assumptions:
* This function is called from NetLink device logic.
*
****************************************************************************/
FAR struct netlink_conn_s *netlink_nextconn(FAR struct netlink_conn_s *conn);
/****************************************************************************
* Name: netlink_active()
*
* Description:
* Find a connection structure that is the appropriate connection for the
* provided NetLink address
*
****************************************************************************/
FAR struct netlink_conn_s *netlink_active(FAR struct sockaddr_nl *addr);
/****************************************************************************
* Name: netlink_add_response
*
* Description:
* Add response data at the tail of the pending response list.
*
* Note: The network will be momentarily locked to support exclusive
* access to the pending response list.
*
****************************************************************************/
void netlink_add_response(FAR struct socket *psock,
FAR struct netlink_response_s *resp);
/****************************************************************************
* Name: netlink_tryget_response
*
* Description:
* Return the next response from the head of the pending response list.
* Responses are returned one-at-a-time in FIFO order.
*
* Note: The network will be momentarily locked to support exclusive
* access to the pending response list.
*
* Returned Value:
* The next response from the head of the pending response list is
* returned. NULL will be returned if the pending response list is
* empty
*
****************************************************************************/
FAR struct netlink_response_s *
netlink_tryget_response(FAR struct socket *psock);
/****************************************************************************
* Name: netlink_get_response
*
* Description:
* Return the next response from the head of the pending response list.
* Responses are returned one-at-a-time in FIFO order.
*
* Note: The network will be momentarily locked to support exclusive
* access to the pending response list.
*
* Returned Value:
* The next response from the head of the pending response list is
* always returned. This function will block until a response is
* received if the pending response list is empty.
*
****************************************************************************/
FAR struct netlink_response_s *
netlink_get_response(FAR struct socket *psock);
/****************************************************************************
* Name: netlink_route_sendto()
*
* Description:
* Perform the sendto() operation for the NETLINK_ROUTE protocol.
*
****************************************************************************/
#ifdef CONFIG_NETLINK_ROUTE
ssize_t netlink_route_sendto(FAR struct socket *psock,
FAR const struct nlmsghdr *nlmsg,
size_t len, int flags,
FAR const struct sockaddr_nl *to,
socklen_t tolen);
#endif
/****************************************************************************
* Name: netlink_route_recvfrom()
*
* Description:
* Perform the recvfrom() operation for the NETLINK_ROUTE protocol.
*
****************************************************************************/
#ifdef CONFIG_NETLINK_ROUTE
ssize_t netlink_route_recvfrom(FAR struct socket *psock,
FAR struct nlmsghdr *nlmsg,
size_t len, int flags,
FAR struct sockaddr_nl *from);
#endif
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_NET_NETLINK */
#endif /* __NET_NETLINK_NETLINK_H */