On 26 May 2014 06:10, Martin Pieuchot <mpieuc...@nolizard.org> wrote:
> Diff below changes the behavior of the kernel to add a route for every
> new IPv4 address, when it is configured on an interface. Actually
> such route is created the first time a program tries to resolve it.
> That's why with this diff you don't see the "cloned" flag:
>
> -10.3.3.2 00:00:24:cc:21:eb UHLc 0 2 - 4
> lo0
> +10.3.3.2 00:00:24:cc:21:eb UHL 0 0 - 4
> lo0
>
> This now automagically created route can still be deleted from userland.
> In such case it will be re-created as soon as a program tries to resolve
> it, just like it is now.
>
> Addresses configured on a point-to-point will have a slightly different
> route added, which matches the IPv6 behavior:
>
> 97.78.45.33 127.0.0.1 H 0 0 - 4
> lo0
>
> Such addresses are also not automatically re-created if they are
> previously deleted, and you'll need to re-configure the address on your
> interface or add it manually if you want it back.
>
> With this diff, a new route will always be created when an address is
> configured, which mean that a RTM_NEWADDR message will be generated at
> least once per-address. If the address is the first in a particular
> subnet, two messages will be generated, one for the route to prefix and
> one for the local route.
>
> Do you see any problem with all of this? Can it goes in?
dhclient used to create such routes but that was removed as useless so
I'm not sure why we want/need to add them back. I'm not a routing
table guru so perhaps this is different in some way.
Extra RTM_NEWADDR messages may cause problems for dhclient, since it
will exit on what it thinks are attempts to add addresses to an
interface. Not sure if RTM_NEWADDR makes sense if all you are doing is
adding a route.
I'm in the middle of some other stuff but I certainly want to test
this to make sure there are no bad side effects on dhclient.
.... Ken
>
> Index: netinet/if_ether.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/netinet/if_ether.c,v
> retrieving revision 1.127
> diff -u -p -r1.127 if_ether.c
> --- netinet/if_ether.c 7 May 2014 08:14:59 -0000 1.127
> +++ netinet/if_ether.c 26 May 2014 09:46:42 -0000
> @@ -174,7 +174,8 @@ arp_rtrequest(int req, struct rtentry *r
> if ((rt->rt_flags & RTF_HOST) == 0 && rt_mask(rt) &&
> satosin(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
> rt->rt_flags |= RTF_CLONING;
> - if (rt->rt_flags & RTF_CLONING) {
> + if (rt->rt_flags & RTF_CLONING ||
> + ((rt->rt_flags & RTF_LLINFO) && !la)) {
> /*
> * Case 1: This route should come from a route to
> iface.
> */
> @@ -189,7 +190,8 @@ arp_rtrequest(int req, struct rtentry *r
> * from it do not need their expiration time set.
> */
> rt->rt_expire = time_second;
> - break;
> + if ((rt->rt_flags & RTF_CLONING) != 0)
> + break;
> }
> /* Announce a new entry if requested. */
> if (rt->rt_flags & RTF_ANNOUNCE)
> Index: netinet/in.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/netinet/in.c,v
> retrieving revision 1.96
> diff -u -p -r1.96 in.c
> --- netinet/in.c 25 Apr 2014 09:44:38 -0000 1.96
> +++ netinet/in.c 26 May 2014 09:46:42 -0000
> @@ -702,6 +702,7 @@ out:
> * carp(4).
> */
> ifa_add(ifp, &ia->ia_ifa);
> + rt_ifa_addloop(&ia->ia_ifa);
>
> if (error && newaddr)
> in_purgeaddr(&ia->ia_ifa);
> @@ -718,6 +719,8 @@ in_purgeaddr(struct ifaddr *ifa)
> splsoftassert(IPL_SOFTNET);
>
> in_ifscrub(ifp, ia);
> +
> + rt_ifa_delloop(&ia->ia_ifa);
>
> ifa_del(ifp, &ia->ia_ifa);
> TAILQ_REMOVE(&in_ifaddr, ia, ia_list);
