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NAME | SYNOPSIS | DESCRIPTION | BUGS | AUTHORS | SEE ALSO | COLOPHON |
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libnetlink(3) Library Functions Manual libnetlink(3)
libnetlink - A library for accessing the netlink service
#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 rtnl_ctrl_data *,
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)
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. If there is a 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, anscillary data, the message itself, and
the jarg cookie as arguments. It will get called for all
received messages. Only one message bundle is received.
If there is a 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 should contain 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.
This library is meant for internal use, use libmnl for new
programs.
The functions sometimes use fprintf and exit when a fatal error
occurs. This library should be named librtnetlink.
netlink/rtnetlink was designed and written by Alexey Kuznetsov.
Andi Kleen wrote the man page.
netlink(7), rtnetlink(7)
/usr/include/linux/rtnetlink.h
This page is part of the iproute2 (utilities for controlling
TCP/IP networking and traffic) project. Information about the
project can be found at
⟨http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2⟩.
If you have a bug report for this manual page, send it to
netdev@vger.kernel.org, shemminger@osdl.org. This page was
obtained from the project's upstream Git repository
⟨https://git.kernel.org/pub/scm/network/iproute2/iproute2.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-06-11.) If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for
the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original
manual page), send a mail to man-pages@man7.org
libnetlink(3)
Pages that refer to this page: netlink(3)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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