Patch from Michael Galassi (nerd@percy.rain.com):

The problem as I saw it was that a route was being added to the routing
tables in the kernel even in the case where the interface pointer in
the route structure was a null, this was fine until an atempt was made
to remove this route at which point a zero derefernce was "commited" and
the inevitable core was dumped.  The easy solution turns out to be to
check for a null interface pointer and not add the route.  The only time
I've observed the problem is when adding a route to the local end of a
point to point connection (SLIP or PPP).

diff --git a/sbin/routed/tables.c b/sbin/routed/tables.c
index a05e023..17a4fb7 100644 (file)
--- a/sbin/routed/tables.c
+++ b/sbin/routed/tables.c
@@ -183,8 +183,21 @@ rtadd(dst, gate, metric, state)
        rt->rt_flags = RTF_UP | flags;
        rt->rt_state = state | RTS_CHANGED;
        rt->rt_ifp = if_ifwithdstaddr(&rt->rt_dst);
        rt->rt_flags = RTF_UP | flags;
        rt->rt_state = state | RTS_CHANGED;
        rt->rt_ifp = if_ifwithdstaddr(&rt->rt_dst);

-       if (rt->rt_ifp == 0)
+       if (rt->rt_ifp == 0) {

                rt->rt_ifp = if_ifwithnet(&rt->rt_router);
                rt->rt_ifp = if_ifwithnet(&rt->rt_router);

+               /*
+                * seems like we can't figure out the interface for the
+                * IP address of the local side of a point to point
+                * connection, we just don't add that entry in the
+                * table. (it seems to already be there anyway)
+                */
+               if (rt->rt_ifp == 0) {
+                       syslog(LOG_DEBUG,
+                              "rtadd: can't get interface for %s",
+                              (*afswitch[dst->sa_family].af_format)(dst));
+                       return;
+               }
+       }

        if ((state & RTS_INTERFACE) == 0)
                rt->rt_flags |= RTF_GATEWAY;
        rt->rt_metric = metric;
        if ((state & RTS_INTERFACE) == 0)
                rt->rt_flags |= RTF_GATEWAY;
        rt->rt_metric = metric;


@@ -257,8 +270,22 @@ rtchange(rt, gate, metric)
        if (add) {
                rt->rt_router = *gate;
                rt->rt_ifp = if_ifwithdstaddr(&rt->rt_router);
        if (add) {
                rt->rt_router = *gate;
                rt->rt_ifp = if_ifwithdstaddr(&rt->rt_router);

-               if (rt->rt_ifp == 0)
+               if (rt->rt_ifp == 0) {

                        rt->rt_ifp = if_ifwithnet(&rt->rt_router);
                        rt->rt_ifp = if_ifwithnet(&rt->rt_router);

+                       /*
+                        * seems like we can't figure out the interface for the
+                        * IP address of the local side of a point to point
+                        * connection, we just don't add that entry in the
+                        * table. (it seems to already be there anyway)
+                        */
+                       if (rt->rt_ifp == 0) {
+                               struct sockaddr *dst = &(rt->rt_dst);
+                               syslog(LOG_DEBUG,
+                                      "rtchange: can't get interface for %s",
+                                      (*afswitch[dst->sa_family].af_format)(dst));
+                               return;
+                       }
+               }

        }
        rt->rt_metric = metric;
        rt->rt_state |= RTS_CHANGED;
        }
        rt->rt_metric = metric;
        rt->rt_state |= RTS_CHANGED;

diff --git a/usr.sbin/routed/tables.c b/usr.sbin/routed/tables.c
index a05e023..17a4fb7 100644 (file)
--- a/usr.sbin/routed/tables.c
+++ b/usr.sbin/routed/tables.c
@@ -183,8 +183,21 @@ rtadd(dst, gate, metric, state)
        rt->rt_flags = RTF_UP | flags;
        rt->rt_state = state | RTS_CHANGED;
        rt->rt_ifp = if_ifwithdstaddr(&rt->rt_dst);
        rt->rt_flags = RTF_UP | flags;
        rt->rt_state = state | RTS_CHANGED;
        rt->rt_ifp = if_ifwithdstaddr(&rt->rt_dst);

-       if (rt->rt_ifp == 0)
+       if (rt->rt_ifp == 0) {

                rt->rt_ifp = if_ifwithnet(&rt->rt_router);
                rt->rt_ifp = if_ifwithnet(&rt->rt_router);

+               /*
+                * seems like we can't figure out the interface for the
+                * IP address of the local side of a point to point
+                * connection, we just don't add that entry in the
+                * table. (it seems to already be there anyway)
+                */
+               if (rt->rt_ifp == 0) {
+                       syslog(LOG_DEBUG,
+                              "rtadd: can't get interface for %s",
+                              (*afswitch[dst->sa_family].af_format)(dst));
+                       return;
+               }
+       }

        if ((state & RTS_INTERFACE) == 0)
                rt->rt_flags |= RTF_GATEWAY;
        rt->rt_metric = metric;
        if ((state & RTS_INTERFACE) == 0)
                rt->rt_flags |= RTF_GATEWAY;
        rt->rt_metric = metric;


@@ -257,8 +270,22 @@ rtchange(rt, gate, metric)
        if (add) {
                rt->rt_router = *gate;
                rt->rt_ifp = if_ifwithdstaddr(&rt->rt_router);
        if (add) {
                rt->rt_router = *gate;
                rt->rt_ifp = if_ifwithdstaddr(&rt->rt_router);

-               if (rt->rt_ifp == 0)
+               if (rt->rt_ifp == 0) {

                        rt->rt_ifp = if_ifwithnet(&rt->rt_router);
                        rt->rt_ifp = if_ifwithnet(&rt->rt_router);

+                       /*
+                        * seems like we can't figure out the interface for the
+                        * IP address of the local side of a point to point
+                        * connection, we just don't add that entry in the
+                        * table. (it seems to already be there anyway)
+                        */
+                       if (rt->rt_ifp == 0) {
+                               struct sockaddr *dst = &(rt->rt_dst);
+                               syslog(LOG_DEBUG,
+                                      "rtchange: can't get interface for %s",
+                                      (*afswitch[dst->sa_family].af_format)(dst));
+                               return;
+                       }
+               }

        }
        rt->rt_metric = metric;
        rt->rt_state |= RTS_CHANGED;
        }
        rt->rt_metric = metric;
        rt->rt_state |= RTS_CHANGED;