pim6d: rework interface address tracking/selection

We only care about link-local addresses for IPv6 operation.  Also, MLD
needs the lowest while PIM needs the highest...

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

diff --git a/pimd/pim_iface.c b/pimd/pim_iface.c
index 5425aec2335ec8926998424f51fce90d8776f12a..9a92f02d1318c4e282b087d0eba1824c98bcd7e2 100644 (file)
--- a/pimd/pim_iface.c
+++ b/pimd/pim_iface.c
@@ -512,6 +512,26 @@ void pim_if_addr_add(struct connected *ifc)
                           CHECK_FLAG(ifc->flags, ZEBRA_IFA_SECONDARY)
                                   ? "secondary"
                                   : "primary");
+#if PIM_IPV != 4
+       if (IN6_IS_ADDR_LINKLOCAL(&ifc->address->u.prefix6) ||
+           IN6_IS_ADDR_LOOPBACK(&ifc->address->u.prefix6)) {
+               if (IN6_IS_ADDR_UNSPECIFIED(&pim_ifp->ll_lowest))
+                       pim_ifp->ll_lowest = ifc->address->u.prefix6;
+               else if (IPV6_ADDR_CMP(&ifc->address->u.prefix6,
+                                      &pim_ifp->ll_lowest) < 0)
+                       pim_ifp->ll_lowest = ifc->address->u.prefix6;
+
+               if (IPV6_ADDR_CMP(&ifc->address->u.prefix6,
+                                 &pim_ifp->ll_highest) > 0)
+                       pim_ifp->ll_highest = ifc->address->u.prefix6;
+
+               if (PIM_DEBUG_ZEBRA)
+                       zlog_debug(
+                               "%s: new link-local %pI6, lowest now %pI6, highest %pI6",
+                               ifc->ifp->name, &ifc->address->u.prefix6,
+                               &pim_ifp->ll_lowest, &pim_ifp->ll_highest);
+       }
+#endif
 
        detect_address_change(ifp, 0, __func__);
 
@@ -711,6 +731,43 @@ void pim_if_addr_del(struct connected *ifc, int force_prim_as_any)
                                   ? "secondary"
                                   : "primary");
 
+#if PIM_IPV == 6
+       struct pim_interface *pim_ifp = ifc->ifp->info;
+
+       if (pim_ifp &&
+           (!IPV6_ADDR_CMP(&ifc->address->u.prefix6, &pim_ifp->ll_lowest) ||
+            !IPV6_ADDR_CMP(&ifc->address->u.prefix6, &pim_ifp->ll_highest))) {
+               struct listnode *cnode;
+               struct connected *cc;
+
+               memset(&pim_ifp->ll_lowest, 0xff, sizeof(pim_ifp->ll_lowest));
+               memset(&pim_ifp->ll_highest, 0, sizeof(pim_ifp->ll_highest));
+
+               for (ALL_LIST_ELEMENTS_RO(ifc->ifp->connected, cnode, cc)) {
+                       if (!IN6_IS_ADDR_LINKLOCAL(&cc->address->u.prefix6) &&
+                           !IN6_IS_ADDR_LOOPBACK(&cc->address->u.prefix6))
+                               continue;
+
+                       if (IPV6_ADDR_CMP(&cc->address->u.prefix6,
+                                         &pim_ifp->ll_lowest) < 0)
+                               pim_ifp->ll_lowest = cc->address->u.prefix6;
+                       if (IPV6_ADDR_CMP(&cc->address->u.prefix6,
+                                         &pim_ifp->ll_highest) > 0)
+                               pim_ifp->ll_highest = cc->address->u.prefix6;
+               }
+
+               if (pim_ifp->ll_lowest.s6_addr[0] == 0xff)
+                       memset(&pim_ifp->ll_lowest, 0,
+                              sizeof(pim_ifp->ll_lowest));
+
+               if (PIM_DEBUG_ZEBRA)
+                       zlog_debug(
+                               "%s: removed link-local %pI6, lowest now %pI6, highest %pI6",
+                               ifc->ifp->name, &ifc->address->u.prefix6,
+                               &pim_ifp->ll_lowest, &pim_ifp->ll_highest);
+       }
+#endif
+
        detect_address_change(ifp, force_prim_as_any, __func__);
 
        pim_if_addr_del_igmp(ifc);
@@ -825,17 +882,36 @@ pim_addr pim_find_primary_addr(struct interface *ifp)
 {
        struct connected *ifc;
        struct listnode *node;
-       int v4_addrs = 0;
-       int v6_addrs = 0;
        struct pim_interface *pim_ifp = ifp->info;
 
-       if (pim_ifp && !pim_addr_is_any(pim_ifp->update_source)) {
+       if (pim_ifp && !pim_addr_is_any(pim_ifp->update_source))
                return pim_ifp->update_source;
-       }
+
+#if PIM_IPV == 6
+       if (pim_ifp)
+               return pim_ifp->ll_highest;
+
+       pim_addr best_addr = PIMADDR_ANY;
 
        for (ALL_LIST_ELEMENTS_RO(ifp->connected, node, ifc)) {
                pim_addr addr;
 
+               if (ifc->address->family != AF_INET6)
+                       continue;
+
+               addr = pim_addr_from_prefix(ifc->address);
+               if (!IN6_IS_ADDR_LINKLOCAL(&addr))
+                       continue;
+               if (pim_addr_cmp(addr, best_addr) > 0)
+                       best_addr = addr;
+       }
+
+       return best_addr;
+#else
+       int v4_addrs = 0;
+       int v6_addrs = 0;
+
+       for (ALL_LIST_ELEMENTS_RO(ifp->connected, node, ifc)) {
                switch (ifc->address->family) {
                case AF_INET:
                        v4_addrs++;
@@ -853,16 +929,9 @@ pim_addr pim_find_primary_addr(struct interface *ifp)
                if (ifc->address->family != PIM_AF)
                        continue;
 
-               addr = pim_addr_from_prefix(ifc->address);
-
-#if PIM_IPV == 6
-               if (!IN6_IS_ADDR_LINKLOCAL(&addr))
-                       continue;
-#endif
-               return addr;
+               return pim_addr_from_prefix(ifc->address);
        }
 
-#if PIM_IPV == 4
        /*
         * If we have no v4_addrs and v6 is configured
         * We probably are using unnumbered
@@ -882,8 +951,8 @@ pim_addr pim_find_primary_addr(struct interface *ifp)
                if (lo_ifp && (lo_ifp != ifp))
                        return pim_find_primary_addr(lo_ifp);
        }
-#endif
        return PIMADDR_ANY;
+#endif
 }
 
 static int pim_iface_next_vif_index(struct interface *ifp)

diff --git a/pimd/pim_iface.h b/pimd/pim_iface.h
index 00ec8e74278027b368b6813c9950fabcbb000bb6..a1c946149d5b61091ecfe94c679cfff269d0b400 100644 (file)
--- a/pimd/pim_iface.h
+++ b/pimd/pim_iface.h
@@ -96,6 +96,13 @@ struct pim_interface {
        uint32_t options; /* bit vector */
        ifindex_t mroute_vif_index;
        struct pim_instance *pim;
+
+#if PIM_IPV == 6
+       /* link-locals: MLD uses lowest addr, PIM uses highest... */
+       pim_addr ll_lowest;
+       pim_addr ll_highest;
+#endif
+
        pim_addr primary_address;       /* remember addr to detect change */
        struct list *sec_addr_list;     /* list of struct pim_secondary_addr */
        pim_addr update_source;         /* user can statically set the primary

diff --git a/pimd/pim_zebra.c b/pimd/pim_zebra.c
index 91d4a479cf3b57bf242b82bdb74bb45b702eddd7..1d5a3dd47f29bedf7d0f0165cbd2d3e0c293c1b9 100644 (file)
--- a/pimd/pim_zebra.c
+++ b/pimd/pim_zebra.c
@@ -179,8 +179,10 @@ static int pim_zebra_if_address_add(ZAPI_CALLBACK_ARGS)
                }
        }
 #else /* PIM_IPV != 4 */
-       /* unused - for now */
        (void)pim_ifp;
+
+       if (p->family == PIM_AF)
+               pim_if_addr_add(c);
 #endif
        return 0;
 }
@@ -229,6 +231,9 @@ static int pim_zebra_if_address_del(ZAPI_CALLBACK_ARGS)
                pim_rp_setup(pim);
                pim_i_am_rp_re_evaluate(pim);
        }
+#else
+       if (p->family == PIM_AF)
+               pim_if_addr_del(c, 0);
 #endif
 
        connected_free(&c);