.\"	$OpenBSD: rt_ifa_add.9,v 1.6 2019/02/13 23:47:43 dlg Exp $
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.\" Copyright (c) 2014 Martin Pieuchot
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.Dd $Mdocdate: February 13 2019 $
.Dt RT_IFA_ADD 9
.Os
.Sh NAME
.Nm rt_ifa_add ,
.Nm rt_ifa_del ,
.Nm rt_ifa_addlocal ,
.Nm rt_ifa_dellocal
.Nd add or delete routing entries associated with an address
.Sh SYNOPSIS
.In sys/types.h
.In sys/socket.h
.In net/if.h
.In net/route.h
.Ft int
.Fo rt_ifa_add
.Fa "struct ifaddr *ifa"
.Fa "int flags"
.Fa "struct sockaddr *dst"
.Fa "unsigned int rdomain"
.Fc
.Ft int
.Fo rt_ifa_del
.Fa "struct ifaddr *ifa"
.Fa "int flags"
.Fa "struct sockaddr *dst"
.Fa "unsigned int rdomain"
.Fc
.Ft int
.Fn rt_ifa_addlocal "struct ifaddr *ifa"
.Ft int
.Fn rt_ifa_dellocal "struct ifaddr *ifa"
.Sh DESCRIPTION
These functions create and delete routing entries required by the network
stack and managed by the kernel.
.Bl -tag -width rt_ifa_addlocalxx
.It Fn rt_ifa_add
Creates and associates a connected routing entry with
.Fa ifa
in the routing domain specified by
.Fa rdomain .
.Pp
Connected routing entries represent routes to prefixes and should be created
with
.Dv RTF_CLONING
in
.Fa flags
and the address of
.Fa ifa
in
.Fa dst .
But for Point-to-Point interfaces, connected routing entries represent routes
to hosts and should be created
with
.Dv RTF_HOST
in
.Fa flags
and the destination address in
.Fa dst .
Connected routing entries have a priority of
.Dv RTP_CONNECTED .
.It Fn rt_ifa_del
Removes the connected routing entry associated with
.Fa ifa
in the routing domain specified by
.Fa rdomain .
.It Fn rt_ifa_addlocal
Creates and associates a local routing entry
with
.Fa ifa .
.Pp
Local routing entries are used to not send packets destined to a local
address on the wire and instead redirect them to
.Xr lo 4 .
They have the lowest priority available,
.Dv RTP_LOCAL ,
and contain a special flag,
.Dv RTF_LOCAL ,
that can be checked to determine if the address is configured on the system.
.It Fn rt_ifa_dellocal
Removes the local routing entry associated with
.Fa ifa .
.El
.Sh CONTEXT
.Fn rt_ifa_add ,
.Fn rt_ifa_del ,
.Fn rt_ifa_addlocal ,
and
.Fn rt_ifa_dellocal
can be called during autoconf, from process context, or from interrupt context.
.Sh RETURN VALUES
.Fn rt_ifa_add ,
.Fn rt_ifa_del ,
.Fn rt_ifa_addlocal ,
and
.Fn rt_ifa_dellocal
will return
.Dv 0
on success and the return value of
.Xr rtrequest 9
otherwise.
.Sh SEE ALSO
.Xr lo 4 ,
.Xr route 4 ,
.Xr rtrequest 9