.\" and in case of nontrivial modification author and date
.\" of the modification is added to the header.
.\" %%%LICENSE_END
+.\"
.\" Based on the original comments from Alexey Kuznetsov, written with
.\" help from Matthew Wilcox.
.\" $Id: rtnetlink.7,v 1.8 2000/01/22 01:55:04 freitag Exp $
-.TH RTNETLINK 7 2013-03-05 "Linux" "Linux Programmer's Manual"
+.\"
+.TH RTNETLINK 7 2017-09-15 "Linux" "Linux Programmer's Manual"
.SH NAME
rtnetlink \- Linux IPv4 routing socket
.SH SYNOPSIS
.B #include <linux/rtnetlink.h>
.br
.B #include <sys/socket.h>
-.sp
+.PP
.BI "rtnetlink_socket = socket(AF_NETLINK, int " socket_type ", NETLINK_ROUTE);"
.SH DESCRIPTION
Rtnetlink allows the kernel's routing tables to be read and altered.
It is based on netlink messages; see
.BR netlink (7)
for more information.
-.\" FIXME ? all these macros could be moved to rtnetlink(3)
+.\" FIXME . ? all these macros could be moved to rtnetlink(3)
.SS Routing attributes
Some rtnetlink messages have optional attributes after the initial header:
-
+.PP
.in +4n
-.nf
+.EX
struct rtattr {
unsigned short rta_len; /* Length of option */
unsigned short rta_type; /* Type of option */
/* Data follows */
};
-.fi
+.EE
.in
-
-These attributes should be only manipulated using the RTA_* macros
+.PP
+These attributes should be manipulated using only the RTA_* macros
or libnetlink, see
.BR rtnetlink (3).
.SS Messages
structure followed by a series of
.I rtattr
structures.
-
-.nf
+.IP
+.EX
struct ifinfomsg {
unsigned char ifi_family; /* AF_UNSPEC */
unsigned short ifi_type; /* Device type */
unsigned int ifi_flags; /* Device flags */
unsigned int ifi_change; /* change mask */
};
-.fi
-
-.\" FIXME ifi_type
+.EE
+.IP
+.\" FIXME Document ifinfomsg.ifi_type
.I ifi_flags
contains the device flags, see
.BR netdevice (7);
.IR ifindex );
.I ifi_change
is reserved for future use and should be always set to 0xFFFFFFFF.
-.na
.TS
tab(:);
c s s
see below
T}:Interface Statistics.
.TE
-.ad
-.sp
+.PP
The value type for
.B IFLA_STATS
is
structure, optionally followed by
.I rtattr
routing attributes.
-
-.nf
+.IP
+.EX
struct ifaddrmsg {
unsigned char ifa_family; /* Address type */
unsigned char ifa_prefixlen; /* Prefixlength of address */
unsigned char ifa_scope; /* Address scope */
int ifa_index; /* Interface index */
};
-.fi
-
+.EE
+.IP
.I ifa_family
is the address family type (currently
.B AF_INET
IFA_ANYCAST:raw protocol address:anycast address
IFA_CACHEINFO:struct ifa_cacheinfo:Address information.
.TE
-.\" FIXME struct ifa_cacheinfo
+.\" FIXME Document struct ifa_cacheinfo
.TP
.BR RTM_NEWROUTE ", " RTM_DELROUTE ", " RTM_GETROUTE
Create, remove or receive information about a network route.
and
.IR rtm_protocol ,
0 is the wildcard.
-
-.nf
+.IP
+.EX
struct rtmsg {
unsigned char rtm_family; /* Address family of route */
unsigned char rtm_dst_len; /* Length of destination */
unsigned int rtm_flags;
};
-.fi
-.na
+.EE
.TS
tab(:);
l l.
refer to an external resolver (not implemented)
T}
.TE
-.ad
-.na
.TS
tab(:);
l l.
RTPROT_BOOT:during boot
RTPROT_STATIC:by the administrator
.TE
-.ad
-
+.sp 1
Values larger than
.B RTPROT_STATIC
are not interpreted by the kernel, they are just for user information.
See
.I <linux/rtnetlink.h>
for the routing daemon identifiers which are already assigned.
-
+.IP
.I rtm_scope
is the distance to the destination:
-.na
.TS
tab(:);
l l.
RT_SCOPE_HOST:route on the local host
RT_SCOPE_NOWHERE:destination doesn't exist
.TE
-.ad
-
+.sp 1
The values between
.B RT_SCOPE_UNIVERSE
and
.B RT_SCOPE_SITE
are available to the user.
-
+.IP
The
.I rtm_flags
have the following meanings:
-.na
.TS
tab(:);
l l.
RTM_F_CLONED:route is cloned from another route
RTM_F_EQUALIZE:a multipath equalizer (not yet implemented)
.TE
-.ad
-
+.sp 1
.I rtm_table
specifies the routing table
.TS
RT_TABLE_MAIN:the main table
RT_TABLE_LOCAL:the local table
.TE
-
+.sp 1
The user may assign arbitrary values between
.B RT_TABLE_UNSPEC
and
RTA_FLOW::
RTA_CACHEINFO::
.TE
-
+.sp 1
.B Fill these values in!
.TP
.BR RTM_NEWNEIGH ", " RTM_DELNEIGH ", " RTM_GETNEIGH
The message contains an
.I ndmsg
structure.
-
-.nf
+.IP
+.EX
struct ndmsg {
unsigned char ndm_family;
int ndm_ifindex; /* Interface index */
__u32 ndm_updated;
__u32 ndm_refcnt;
};
-.fi
-
+.EE
+.IP
.I ndm_state
is a bit mask of the following states:
.TS
NUD_NOARP:a device with no destination cache
NUD_PERMANENT:a static entry
.TE
-
+.sp 1
Valid
.I ndm_flags
are:
NTF_PROXY:a proxy arp entry
NTF_ROUTER:an IPv6 router
.TE
-
-.\" FIXME
+.sp 1
+.\" FIXME .
.\" document the members of the struct better
The
.I rtattr
NDA_LLADDR:a neighbor cache link layer address
NDA_CACHEINFO:cache statistics.
.TE
-
+.sp 1
If the
.I rta_type
field is
-.B NDA_CACHEINFO
+.BR NDA_CACHEINFO ,
then a
.I struct nda_cacheinfo
header follows
.I struct tcmsg
and may be followed by a series of
attributes.
-
-.nf
+.IP
+.EX
struct tcmsg {
unsigned char tcm_family;
int tcm_ifindex; /* interface index */
__u32 tcm_parent; /* Parent qdisc */
__u32 tcm_info;
};
-.fi
+.EE
.TS
tab(:);
c s s
TCA_KIND:asciiz string:Name of queueing discipline
TCA_OPTIONS:byte sequence:Qdisc-specific options follow
TCA_STATS:struct tc_stats:Qdisc statistics.
-TCA_XSTATS:qdisc specific:Module-specific statistics.
+TCA_XSTATS:qdisc-specific:Module-specific statistics.
TCA_RATE:struct tc_estimator:Rate limit.
.TE
-
-In addition various other qdisc module specific attributes are allowed.
+.sp 1
+In addition, various other qdisc-module-specific attributes are allowed.
For more information see the appropriate include files.
.TP
.BR RTM_NEWTCLASS ", " RTM_DELTCLASS ", " RTM_GETTCLASS