When an IPv6 address is configured on a point-to-point interface, it
is associated to nd6_rtrequest(). This is because nd6_request()
contains a hack to automatically create a route to loopback for p2p
interfaces.
The resulting route looks like this:
fe80::300:245f:fedc:22f8%pppoe0 link#12 HL 0
0 - 4 lo0
I'd like to stop abusing nd6_rtrequest() for point-to-point interfaces
because I want to introduce a similar behavior for IPv4. So the diff
below adds a sppp_rtrequest() function that works for both IPv4 and
IPv6 and creates a local route if the loopback interface has an address
of the same family. This diff introduce a difference in the routing
table, see below, but it shouldn't matter. The RTF_LLINFO flags is
necessary for ND6 or ARP, not for p2p interfaces.
-fe80::300:245f:fedc:22f8%pppoe0 link#12 HL 0
0 - 4 lo0
-2011:4b10:1003:ff::1 link#12 HL 0
0 - 4 lo0
+fe80::300:245f:fedc:22f8%pppoe0 ::1 H 0
0 - 4 lo0
+2011:4b10:1003:ff::1 ::1 H 0
0 - 4 lo0
ok?
Index: net/if_spppsubr.c
===================================================================
RCS file: /home/ncvs/src/sys/net/if_spppsubr.c,v
retrieving revision 1.119
diff -u -p -r1.119 if_spppsubr.c
--- net/if_spppsubr.c 3 Apr 2014 06:06:56 -0000 1.119
+++ net/if_spppsubr.c 9 Apr 2014 09:03:05 -0000
@@ -242,6 +242,7 @@ static struct timeout keepalive_ch;
struct ifnet *ifp = &sp->pp_if; \
int debug = ifp->if_flags & IFF_DEBUG
+void sppp_rtrequest(int, struct rtentry *);
int sppp_output(struct ifnet *ifp, struct mbuf *m,
struct sockaddr *dst, struct rtentry *rt);
@@ -1010,7 +1011,8 @@ sppp_pick(struct ifnet *ifp)
int
sppp_ioctl(struct ifnet *ifp, u_long cmd, void *data)
{
- struct ifreq *ifr = (struct ifreq*) data;
+ struct ifreq *ifr = data;
+ struct ifaddr *ifa = data;
struct sppp *sp = (struct sppp*) ifp;
int s, rv, going_up, going_down, newmode;
@@ -1023,6 +1025,7 @@ sppp_ioctl(struct ifnet *ifp, u_long cmd
case SIOCSIFADDR:
if_up(ifp);
+ ifa->ifa_rtrequest = sppp_rtrequest;
/* FALLTHROUGH */
case SIOCSIFFLAGS:
@@ -1108,6 +1111,61 @@ sppp_ioctl(struct ifnet *ifp, u_long cmd
return rv;
}
+void
+sppp_rtrequest(int req, struct rtentry *rt)
+{
+ struct ifnet *ifp = rt->rt_ifp;
+ struct ifaddr *ifa, *lo0ifa;
+
+ switch (req) {
+ case RTM_ADD:
+ /*
+ * Here RTF_LLINFO means we're adding a route to
+ * loopback to always have an entry pointing to
+ * the address of the interface as destination.
+ */
+ if ((rt->rt_flags & RTF_LLINFO) == 0)
+ break;
+
+ TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
+ if (memcmp(rt_key(rt), ifa->ifa_addr,
+ rt_key(rt)->sa_len) == 0)
+ break;
+ }
+
+ if (ifa == NULL)
+ break;
+
+ TAILQ_FOREACH(lo0ifa, &lo0ifp->if_addrlist, ifa_list)
+ if (lo0ifa->ifa_addr->sa_family ==
+ ifa->ifa_addr->sa_family)
+ break;
+
+ if (lo0ifa == NULL)
+ break;
+
+ rt_setgate(rt, rt_key(rt), lo0ifa->ifa_addr, ifp->if_rdomain);
+ rt->rt_ifp = lo0ifp;
+ rt->rt_flags &= ~RTF_LLINFO;
+
+ /*
+ * make sure to set rt->rt_ifa to the interface
+ * address we are using, otherwise we will have trouble
+ * with source address selection.
+ */
+ if (ifa != rt->rt_ifa) {
+ ifafree(rt->rt_ifa);
+ ifa->ifa_refcnt++;
+ rt->rt_ifa = ifa;
+ }
+ break;
+
+ case RTM_DELETE:
+ case RTM_RESOLVE:
+ default:
+ break;
+ }
+}
/*
* Cisco framing implementation.
Index: netinet6/in6.c
===================================================================
RCS file: /home/ncvs/src/sys/netinet6/in6.c,v
retrieving revision 1.134
diff -u -p -r1.134 in6.c
--- netinet6/in6.c 3 Apr 2014 08:22:10 -0000 1.134
+++ netinet6/in6.c 9 Apr 2014 09:03:05 -0000
@@ -1369,7 +1369,8 @@ in6_ifinit(struct ifnet *ifp, struct in6
ifacount++;
}
- if ((ifacount <= 1 || ifp->if_type == IFT_CARP) && ifp->if_ioctl &&
+ if ((ifacount <= 1 || ifp->if_type == IFT_CARP ||
+ (ifp->if_flags & IFF_POINTOPOINT)) && ifp->if_ioctl &&
(error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia6))) {
splx(s);
return (error);
@@ -1396,7 +1397,9 @@ in6_ifinit(struct ifnet *ifp, struct in6
/* Add ownaddr as loopback rtentry, if necessary (ex. on p2p link). */
if (newhost) {
/* set the rtrequest function to create llinfo */
- ia6->ia_ifa.ifa_rtrequest = nd6_rtrequest;
+ if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
+ ia6->ia_ifa.ifa_rtrequest = nd6_rtrequest;
+
rt_ifa_addloop(&(ia6->ia_ifa));
}
