.\"	$OpenBSD: rt_ifa_add.9,v 1.1 2014/04/10 13:47:21 mpi Exp $
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.\" Copyright (c) 2014 Martin Pieuchot 
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.Dd $Mdocdate: April 10 2014 $
.Dt RT_IFA_ADD 9
.Os
.Sh NAME
.Nm rt_ifa_add ,
.Nm rt_ifa_del ,
.Nm rt_ifa_addloop ,
.Nm rt_ifa_delloop
.Nd add or delete routes associated with an address
.Sh SYNOPSIS
.In sys/socket.h
.In net/if.h
.In net/route.h
.Ft int
.Fn rt_ifa_add "struct ifaddr *ifa" "int flags" "struct sockaddr *dst"
.Ft int
.Fn rt_ifa_del "struct ifaddr *ifa" "int flags" "struct sockaddr *dst"
.Ft void
.Fn rt_ifa_addloop "struct ifaddr *ifa"
.Ft void
.Fn rt_ifa_delloop "struct ifaddr *ifa"
.Sh DESCRIPTION
These functions create and delete routes required by the network stack
and managed by the kernel.
.Bl -tag -width rt_ifa_addloopxx
.It Fn rt_ifa_add
Creates and associates a connected route with
.Fa ifa .
.Pp
Connected routes are mostly 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 routes are routes to hosts and
should be created
with
.Dv RTF_HOST
in
.Fa flags
and the destination address in
.Fa dst .
Connected routes have a priority of
.Dv RTP_CONNECTED .
.It Fn rt_ifa_del
Removes the connected route associated with
.Fa ifa .
.It Fn rt_ifa_addloop
Creates and associates a local route
with
.Fa ifa .
.Pp
Local routes 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_delloop
Removes the local route associated with
.Fa ifa .
.El
.Sh CONTEXT
.Fn rt_ifa_add ,
.Fn rt_ifa_del ,
.Fn rt_ifa_addloop ,
and
.Fn rt_ifa_delloop
can be called during autoconf, from process context, or from interrupt context.
.Sh RETURN VALUES
.Fn rt_ifa_add
and
.Fn rt_ifa_del
will return
.Dv 0
on success and the return value of
.Xr rtrequest1 9
otherwise.
.Sh SEE ALSO
.Xr lo 4 ,
.Xr route 4 ,
.Xr rtrequest1 9