2 * Copyright (C) 2008-2019 Tobias Brunner
3 * HSR Hochschule fuer Technik Rapperswil
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
12 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 #ifndef KERNEL_NETLINK_SHARED_H_
17 #define KERNEL_NETLINK_SHARED_H_
21 #include <linux/rtnetlink.h>
24 * Default buffer size.
26 * 1024 byte is currently sufficient for all operations.
28 #ifndef KERNEL_NETLINK_BUFSIZE
29 #define KERNEL_NETLINK_BUFSIZE 1024
33 * General purpose netlink buffer.
35 * Some platforms require an enforced alignment to four bytes (e.g. ARM).
39 u_char bytes
[KERNEL_NETLINK_BUFSIZE
];
40 } netlink_buf_t
__attribute__((aligned(RTA_ALIGNTO
)));
42 typedef struct netlink_socket_t netlink_socket_t
;
45 * Wrapper around a netlink socket.
47 struct netlink_socket_t
{
50 * Send a netlink message and wait for a reply.
52 * @param in netlink message to send
53 * @param out received netlink message
54 * @param out_len length of the received message
56 status_t (*send
)(netlink_socket_t
*this, struct nlmsghdr
*in
,
57 struct nlmsghdr
**out
, size_t *out_len
);
60 * Send a netlink message and wait for its acknowledge.
62 * @param in netlink message to send
64 status_t (*send_ack
)(netlink_socket_t
*this, struct nlmsghdr
*in
);
69 void (*destroy
)(netlink_socket_t
*this);
73 * Create a netlink_socket_t object.
75 * @param protocol protocol type (e.g. NETLINK_XFRM or NETLINK_ROUTE)
76 * @param names optional enum names for Netlink messages
77 * @param parallel support parallel queries on this Netlink socket
79 netlink_socket_t
*netlink_socket_create(int protocol
, enum_name_t
*names
,
83 * Creates an rtattr and adds it to the given netlink message.
85 * @param hdr netlink message
86 * @param rta_type type of the rtattr
87 * @param data data to add to the rtattr
88 * @param buflen length of the netlink message buffer
90 void netlink_add_attribute(struct nlmsghdr
*hdr
, int rta_type
, chunk_t data
,
94 * Creates an rtattr under which other rtattrs are nested to the given netlink
97 * The returned pointer has to be passed to netlink_nested_end() after the
98 * nested attributes have been added to the message.
100 * @param hdr netlink message
101 * @param buflen size of full netlink buffer
102 * @param type RTA type
103 * @return attribute pointer
105 void *netlink_nested_start(struct nlmsghdr
*hdr
, size_t buflen
, int type
);
108 * Updates the length of the given attribute after nested attributes were added.
110 * @param hdr netlink message
111 * @param attr attribute returned from netlink_nested_start()
113 void netlink_nested_end(struct nlmsghdr
*hdr
, void *attr
);
116 * Reserve space in a netlink message for given size and type, returning buffer.
118 * @param hdr netlink message
119 * @param buflen size of full netlink buffer
120 * @param type RTA type
121 * @param len length of RTA data
122 * @return buffer to len bytes of attribute data, NULL on error
124 void* netlink_reserve(struct nlmsghdr
*hdr
, int buflen
, int type
, int len
);
127 * Determine buffer size for received messages (e.g. events).
129 * @return buffer size
131 u_int
netlink_get_buflen();
133 #endif /* KERNEL_NETLINK_SHARED_H_ */