Интерактивная система просмотра системных руководств (man-ов)
libnetlink (3)
libnetlink (3) ( Русские man: Библиотечные вызовы )
>> libnetlink (3) ( Linux man: Библиотечные вызовы )
NAME
libnetlink - A library for accessing the netlink service
SYNOPSIS
#include <asm/types.h>
#include <libnetlink.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
int rtnl_send(struct rtnl_handle *rth, char *buf, int len)
int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
int rtnl_dump_filter(struct rtnl_handle *rth,
int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
void *arg1,
int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
void *arg2)
int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
unsigned groups, struct nlmsghdr *answer,
int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
void *jarg)
int rtnl_listen(struct rtnl_handle *rtnl,
int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
void *jarg)
int rtnl_from_file(FILE *rtnl,
int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
void *jarg)
int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen)
DESCRIPTION
libnetlink provides a higher level interface to
rtnetlink(7).
The read functions return 0 on success and a negative errno on failure.
The send functions return the amount of data sent, or -1 on error.
rtnl_open
Open a rtnetlink socket and save the state into the
rth
handle. This handle is passed to all subsequent calls.
subscriptions
is a bitmap of the rtnetlink multicast groups the socket will be
a member of.
rtnl_wilddump_request
Request a full dump of the
type
database for
family
addresses.
type
is a rtnetlink message type.
rtnl_dump_request
Request a full dump of the
type
data buffer into
buf
with maximum length of
len.type
is a rtnetlink message type.
rtnl_dump_filter
Receive netlink data after a request and filter it.
The
filter
callback checks if the received message is wanted. It gets the source
address of the message, the message itself and
arg1
as arguments. 0 as return means that the filter passed, a negative
value is returned
by
rtnl_dump_filter
in case of error. NULL for
filter
means to not use a filter.
junk
is used to filter messages not destined to the local socket.
Only one message bundle is received. Unless there is no message
pending, this function does not block.
rtnl_listen
Receive netlink data after a request and pass it to
handler.handler
is a callback that gets the message source address, the message itself,
and the
jarg
cookie as arguments. It will get called for all received messages.
Only one message bundle is received. Unless there is no message
pending this function does not block.
rtnl_from_file
Works like
rtnl_listen,
but reads a netlink message bundle from the file
file
and passes the messages to
handler
for parsing. The file contains raw data as received from a rtnetlink socket.
The following functions are useful to construct custom rtnetlink messages. For
simple database dumping with filtering it is better to use the higher level
functions above. See
rtnetlink(3)
and
netlink(3)
on how to generate a rtnetlink message. The following utility functions
require a continuous buffer that already contains a netlink message header
and a rtnetlink request.
rtnl_send
Send the rtnetlink message in
buf
of length
len
to handle
rth.
addattr32
Add a __u32 attribute of type
type
and with value
data
to netlink message
n,
which is part of a buffer of length
maxlen.
addattr_l
Add a variable length attribute of type
type
and with value
data
and
alen
length to netlink message
n,
which is part of a buffer of length
maxlen.data
is copied.
rta_addattr32
Initialize the rtnetlink attribute
rta
with a __u32 data value.
rta_addattr32
Initialize the rtnetlink attribute
rta
with a variable length data value.
BUGS
The functions sometimes use fprintf and exit when a fatal error occurs.
This library should be named librtnetlink.
AUTHORS
netlink/rtnetlink was designed and written by Alexey Kuznetsov.
Andi Kleen wrote the man page.
