On 28 May 2014 10:15, Martin Pieuchot <[email protected]> wrote:
> On 26/05/14(Mon) 15:17, Martin Pieuchot wrote:
>> On 26/05/14(Mon) 08:03, Kenneth Westerback wrote:
>> > [...]
>> >
>> > 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.
>>
>> We want it back to be able to tell if an address is configured locally
>> by using the routing table. But to be able to trust the routing table
>> we must ensure that every local address is associated to a route entry.
>> This diff is a step in this direction.
>>
>> > 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.
>>
>> That's a really good question, and I don't have the answer.
>>
>> Originally RTM_NEWADDR was generated when a route to prefix was added
>> for a new address. It was simple: 1 address -> 1 route + message.
>>
>> Later on the logic in netinet/in.c has been modified to be able to setup
>> an address without adding a route to prefix, if this route was already
>> present for example. That's what happens if you have two addresses on
>> the same subnet configured on your machine. With this, we now have:
>> 1 address -> maybe 1 route + message.
>>
>> With this diff we always create a route, but maybe a second one if it is
>> the first address of a subnet. So we have: 1 address -> 1 or 2 route +
>> messages.
>
> Here's a more complete diff that seems to not freak out dhclient(8). It
> makes use of the RTF_LOCAL flag to restore the original behavior of the
> RTM_NEWADDR message.
>
> I appreciate if people can test it and report back. It should be pretty
> safe from the IPv4 side, but I'd like to know if it causes any
> regression in IPv6 land.
>
In my tree and snap a-building.
.... Ken
> Index: net/route.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/net/route.c,v
> retrieving revision 1.168
> diff -u -p -r1.168 route.c
> --- net/route.c 27 May 2014 19:38:15 -0000 1.168
> +++ net/route.c 28 May 2014 11:59:14 -0000
> @@ -1097,6 +1097,7 @@ rt_ifa_add(struct ifaddr *ifa, int flags
> struct sockaddr_rtlabel sa_rl;
> struct rt_addrinfo info;
> u_short rtableid = ifa->ifa_ifp->if_rdomain;
> + u_int8_t prio = RTP_CONNECTED;
> int error;
>
> memset(&info, 0, sizeof(info));
> @@ -1110,7 +1111,10 @@ rt_ifa_add(struct ifaddr *ifa, int flags
> if ((flags & RTF_HOST) == 0)
> info.rti_info[RTAX_NETMASK] = ifa->ifa_netmask;
>
> - error = rtrequest1(RTM_ADD, &info, RTP_CONNECTED, &nrt, rtableid);
> + if (flags & RTF_LOCAL)
> + prio = RTP_LOCAL;
> +
> + error = rtrequest1(RTM_ADD, &info, prio, &nrt, rtableid);
> if (error == 0 && (rt = nrt) != NULL) {
> rt->rt_refcnt--;
> if (rt->rt_ifa != ifa) {
> @@ -1125,7 +1129,8 @@ rt_ifa_add(struct ifaddr *ifa, int flags
> if (ifa->ifa_rtrequest)
> ifa->ifa_rtrequest(RTM_ADD, rt);
> }
> - rt_newaddrmsg(RTM_ADD, ifa, error, nrt);
> + if (flags & RTF_LOCAL)
> + rt_newaddrmsg(RTM_ADD, ifa, error, nrt);
> }
> return (error);
> }
> @@ -1139,6 +1144,7 @@ rt_ifa_del(struct ifaddr *ifa, int flags
> struct rt_addrinfo info;
> struct sockaddr_rtlabel sa_rl;
> u_short rtableid = ifa->ifa_ifp->if_rdomain;
> + u_int8_t prio = RTP_CONNECTED;
> int error;
>
> if ((flags & RTF_HOST) == 0 && ifa->ifa_netmask) {
> @@ -1173,9 +1179,13 @@ rt_ifa_del(struct ifaddr *ifa, int flags
> if ((flags & RTF_HOST) == 0)
> info.rti_info[RTAX_NETMASK] = ifa->ifa_netmask;
>
> - error = rtrequest1(RTM_DELETE, &info, RTP_CONNECTED, &nrt, rtableid);
> + if (flags & RTF_LOCAL)
> + prio = RTP_LOCAL;
> +
> + error = rtrequest1(RTM_DELETE, &info, prio, &nrt, rtableid);
> if (error == 0 && (rt = nrt) != NULL) {
> - rt_newaddrmsg(RTM_DELETE, ifa, error, nrt);
> + if (flags & RTF_LOCAL)
> + rt_newaddrmsg(RTM_DELETE, ifa, error, nrt);
> if (rt->rt_refcnt <= 0) {
> rt->rt_refcnt++;
> rtfree(rt);
> @@ -1199,7 +1209,8 @@ rt_ifa_addloop(struct ifaddr *ifa)
> rt = rtalloc1(ifa->ifa_addr, 0, ifa->ifa_ifp->if_rdomain);
> if (rt == NULL || (rt->rt_flags & RTF_HOST) == 0 ||
> (rt->rt_ifp->if_flags & IFF_LOOPBACK) == 0)
> - rt_ifa_add(ifa, RTF_UP| RTF_HOST | RTF_LLINFO, ifa->ifa_addr);
> + rt_ifa_add(ifa, RTF_UP| RTF_HOST | RTF_LLINFO | RTF_LOCAL,
> + ifa->ifa_addr);
> if (rt)
> rt->rt_refcnt--;
> }
> @@ -1223,7 +1234,8 @@ rt_ifa_delloop(struct ifaddr *ifa)
> rt = rtalloc1(ifa->ifa_addr, 0, ifa->ifa_ifp->if_rdomain);
> if (rt != NULL && (rt->rt_flags & RTF_HOST) != 0 &&
> (rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0)
> - rt_ifa_del(ifa, RTF_HOST | RTF_LLINFO, ifa->ifa_addr);
> + rt_ifa_del(ifa, RTF_HOST | RTF_LLINFO | RTF_LOCAL,
> + ifa->ifa_addr);
> if (rt)
> rt->rt_refcnt--;
> }
> 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 28 May 2014 11:59:14 -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 28 May 2014 11:59:14 -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);
