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/*
* Copyright (C) 2008 Tobias Brunner
* Hochschule fuer Technik Rapperswil
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
#ifndef KERNEL_NETLINK_SHARED_H_
#define KERNEL_NETLINK_SHARED_H_
#include <library.h>
#include <linux/rtnetlink.h>
/**
* Default buffer size.
*
* 1024 byte is currently sufficient for all operations.
*/
#ifndef KERNEL_NETLINK_BUFSIZE
#define KERNEL_NETLINK_BUFSIZE 1024
#endif
/**
* General purpose netlink buffer.
*
* Some platforms require an enforced aligment to four bytes (e.g. ARM).
*/
typedef union {
struct nlmsghdr hdr;
u_char bytes[KERNEL_NETLINK_BUFSIZE];
} netlink_buf_t __attribute__((aligned(RTA_ALIGNTO)));
typedef struct netlink_socket_t netlink_socket_t;
/**
* Wrapper around a netlink socket.
*/
struct netlink_socket_t {
/**
* Send a netlink message and wait for a reply.
*
* @param in netlink message to send
* @param out received netlink message
* @param out_len length of the received message
*/
status_t (*send)(netlink_socket_t *this, struct nlmsghdr *in,
struct nlmsghdr **out, size_t *out_len);
/**
* Send a netlink message and wait for its acknowledge.
*
* @param in netlink message to send
*/
status_t (*send_ack)(netlink_socket_t *this, struct nlmsghdr *in);
/**
* Destroy the socket.
*/
void (*destroy)(netlink_socket_t *this);
};
/**
* Create a netlink_socket_t object.
*
* @param protocol protocol type (e.g. NETLINK_XFRM or NETLINK_ROUTE)
* @param names optional enum names for Netlink messages
* @param parallel support parallel queries on this Netlink socket
*/
netlink_socket_t *netlink_socket_create(int protocol, enum_name_t *names,
bool parallel);
/**
* Creates an rtattr and adds it to the given netlink message.
*
* @param hdr netlink message
* @param rta_type type of the rtattr
* @param data data to add to the rtattr
* @param buflen length of the netlink message buffer
*/
void netlink_add_attribute(struct nlmsghdr *hdr, int rta_type, chunk_t data,
size_t buflen);
/**
* Reserve space in a netlink message for given size and type, returning buffer.
*
* @param hdr netlink message
* @param buflen size of full netlink buffer
* @param type RTA type
* @param len length of RTA data
* @return buffer to len bytes of attribute data, NULL on error
*/
void* netlink_reserve(struct nlmsghdr *hdr, int buflen, int type, int len);
#endif /* KERNEL_NETLINK_SHARED_H_ */
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