+++ /dev/null
-.\" This man page is Copyright (C) 1999 Andi Kleen <ak@muc.de>.
-.\"
-.\" %%%LICENSE_START(VERBATIM_ONE_PARA)
-.\" Permission is granted to distribute possibly modified copies
-.\" of this page provided the header is included verbatim,
-.\" and in case of nontrivial modification author and date
-.\" of the modification is added to the header.
-.\" %%%LICENSE_END
-.\"
-.\" $Id: rtnetlink.3,v 1.2 1999/05/18 10:35:10 freitag Exp $
-.\"
-.TH RTNETLINK 3 2014-09-06 "GNU" "Linux Programmer's Manual"
-.SH NAME
-rtnetlink \- macros to manipulate rtnetlink messages
-.SH SYNOPSIS
-.B #include <asm/types.h>
-.br
-.B #include <linux/netlink.h>
-.br
-.B #include <linux/rtnetlink.h>
-.br
-.B #include <sys/socket.h>
-
-.BI "rtnetlink_socket = socket(AF_NETLINK, int " socket_type \
-", NETLINK_ROUTE);"
-.sp
-.BI "int RTA_OK(struct rtattr *" rta ", int " rtabuflen );
-.sp
-.BI "void *RTA_DATA(struct rtattr *" rta );
-.sp
-.BI "unsigned int RTA_PAYLOAD(struct rtattr *" rta );
-.sp
-.BI "struct rtattr *RTA_NEXT(struct rtattr *" rta \
-", unsigned int " rtabuflen );
-.sp
-.BI "unsigned int RTA_LENGTH(unsigned int " length );
-.sp
-.BI "unsigned int RTA_SPACE(unsigned int "length );
-.SH DESCRIPTION
-All
-.BR rtnetlink (7)
-messages consist of a
-.BR netlink (7)
-message header and appended attributes.
-The attributes should be manipulated only using the macros provided here.
-.PP
-.BI RTA_OK( rta ", " attrlen )
-returns true if
-.I rta
-points to a valid routing attribute;
-.I attrlen
-is the running length of the attribute buffer.
-When not true then you must assume there are no more attributes in the
-message, even if
-.I attrlen
-is nonzero.
-.PP
-.BI RTA_DATA( rta )
-returns a pointer to the start of this attribute's data.
-.PP
-.BI RTA_PAYLOAD( rta )
-returns the length of this attribute's data.
-.PP
-.BI RTA_NEXT( rta ", " attrlen )
-gets the next attribute after
-.IR rta .
-Calling this macro will update
-.IR attrlen .
-You should use
-.B RTA_OK
-to check the validity of the returned pointer.
-.PP
-.BI RTA_LENGTH( len )
-returns the length which is required for
-.I len
-bytes of data plus the header.
-.PP
-.BI RTA_SPACE( len )
-returns the amount of space which will be needed in a message with
-.I len
-bytes of data.
-.SH CONFORMING TO
-These macros are nonstandard Linux extensions.
-.SH BUGS
-This manual page is incomplete.
-.SH EXAMPLE
-.\" FIXME . ? would be better to use libnetlink in the EXAMPLE code here
-Creating a rtnetlink message to set the MTU of a device:
-.nf
- #include <linux/rtnetlink.h>
-
- ...
-
- struct {
- struct nlmsghdr nh;
- struct ifinfomsg if;
- char attrbuf[512];
- } req;
-
- struct rtattr *rta;
- unsigned int mtu = 1000;
-
- int rtnetlink_sk = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
-
- memset(&req, 0, sizeof(req));
- req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
- req.nh.nlmsg_flags = NLM_F_REQUEST;
- req.nh.nlmsg_type = RTM_NEWLINK;
- req.if.ifi_family = AF_UNSPEC;
- req.if.ifi_index = INTERFACE_INDEX;
- req.if.ifi_change = 0xffffffff; /* ??? */
- rta = (struct rtattr *)(((char *) &req) +
- NLMSG_ALIGN(req.nh.nlmsg_len));
- rta\->rta_type = IFLA_MTU;
- rta\->rta_len = RTA_LENGTH(sizeof(unsigned int));
- req.n.nlmsg_len = NLMSG_ALIGN(req.nh.nlmsg_len) +
- RTA_LENGTH(sizeof(mtu));
- memcpy(RTA_DATA(rta), &mtu, sizeof(mtu));
- send(rtnetlink_sk, &req, req.nh.nlmsg_len, 0);
-.fi
-.SH SEE ALSO
-.BR netlink (3),
-.BR netlink (7),
-.BR rtnetlink (7)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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