zebra: static: update on ifindex changes

Whenever an interface is created or deleted in the system, we need to
check whether we have static routes referencing that interface by name.
If so, we need to [un]install these routes.

This has the unfortunate side effect of making static routes with
non-existent interfaces disappear from "show ip route", but I think
that's acceptable (and I don't see a "good" fix for that).

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

diff --git a/zebra/interface.c b/zebra/interface.c
index 03ddf8d3864a73f106b136c90e31b78d7dfac73b..a2ac0a51150c93ddbdec4e0bae4cccb2c63748e7 100644 (file)
--- a/zebra/interface.c
+++ b/zebra/interface.c
@@ -48,6 +48,7 @@
 #include "zebra/rt_netlink.h"
 #include "zebra/interface.h"
 #include "zebra/zebra_vxlan.h"
+#include "zebra/zebra_static.h"
 
 #define ZEBRA_PTM_SUPPORT
 
@@ -510,6 +511,8 @@ void if_add_update(struct interface *ifp)
                        zlog_debug(
                                "interface %s vrf %u index %d becomes active.",
                                ifp->name, ifp->vrf_id, ifp->ifindex);
+
+               static_ifindex_update(ifp, true);
        } else {
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("interface %s vrf %u index %d is added.",
@@ -675,6 +678,8 @@ void if_delete_update(struct interface *ifp)
                zlog_debug("interface %s vrf %u index %d is now inactive.",
                           ifp->name, ifp->vrf_id, ifp->ifindex);
 
+       static_ifindex_update(ifp, false);
+
        /* Delete connected routes from the kernel. */
        if_delete_connected(ifp);
 

diff --git a/zebra/zebra_static.c b/zebra/zebra_static.c
index 33ebb88e03fc92eb9683833192a0ba0e064ef5f0..dba228ea350df68c7d0ba04840a54dc8d95305c9 100644 (file)
--- a/zebra/zebra_static.c
+++ b/zebra/zebra_static.c
@@ -24,6 +24,7 @@
 #include <lib/nexthop.h>
 #include <lib/memory.h>
 #include <lib/srcdest_table.h>
+#include <lib/if.h>
 
 #include "vty.h"
 #include "zebra/debug.h"
@@ -214,6 +215,9 @@ void static_install_route(afi_t afi, safi_t safi, struct prefix *p,
        }
 }
 
+/* this works correctly with IFNAME<>IFINDEX because a static route on a
+ * non-active interface will have IFINDEX_INTERNAL and thus compare false
+ */
 static int static_nexthop_same(struct nexthop *nexthop, struct static_route *si)
 {
        if (nexthop->type == NEXTHOP_TYPE_BLACKHOLE
@@ -360,7 +364,7 @@ void static_uninstall_route(afi_t afi, safi_t safi, struct prefix *p,
 
 int static_add_route(afi_t afi, safi_t safi, u_char type, struct prefix *p,
                     struct prefix_ipv6 *src_p, union g_addr *gate,
-                    ifindex_t ifindex, const char *ifname, u_char flags,
+                    const char *ifname, u_char flags,
                     route_tag_t tag, u_char distance, struct zebra_vrf *zvrf,
                     struct static_nh_label *snh_label)
 {
@@ -381,7 +385,7 @@ int static_add_route(afi_t afi, safi_t safi, u_char type, struct prefix *p,
                || type == STATIC_IPV6_GATEWAY_IFNAME))
                return -1;
 
-       if (!ifindex
+       if (!ifname
            && (type == STATIC_IFNAME
                || type == STATIC_IPV4_GATEWAY_IFNAME
                || type == STATIC_IPV6_GATEWAY_IFNAME))
@@ -397,7 +401,7 @@ int static_add_route(afi_t afi, safi_t safi, u_char type, struct prefix *p,
                                   && IPV4_ADDR_SAME(gate, &si->addr.ipv4))
                                  || (afi == AFI_IP6
                                      && IPV6_ADDR_SAME(gate, &si->addr.ipv6))))
-                   && (!ifindex || ifindex == si->ifindex)) {
+                   && (!strcmp (ifname ? ifname : "", si->ifname))) {
                        if ((distance == si->distance) && (tag == si->tag)
                            && !memcmp(&si->snh_label, snh_label,
                                       sizeof(struct static_nh_label))
@@ -411,7 +415,7 @@ int static_add_route(afi_t afi, safi_t safi, u_char type, struct prefix *p,
 
        /* Distance or tag or label changed, delete existing first. */
        if (update)
-               static_delete_route(afi, safi, type, p, src_p, gate, ifindex,
+               static_delete_route(afi, safi, type, p, src_p, gate, ifname,
                                    update->tag, update->distance, zvrf,
                                    &update->snh_label);
 
@@ -423,9 +427,9 @@ int static_add_route(afi_t afi, safi_t safi, u_char type, struct prefix *p,
        si->flags = flags;
        si->tag = tag;
        si->vrf_id = zvrf_id(zvrf);
-       si->ifindex = ifindex;
-       if (si->ifindex)
-               strcpy(si->ifname, ifname);
+       if (ifname)
+               strlcpy(si->ifname, ifname, sizeof(si->ifname));
+       si->ifindex = IFINDEX_INTERNAL;
 
        switch (type) {
        case STATIC_IPV4_GATEWAY:
@@ -471,15 +475,25 @@ int static_add_route(afi_t afi, safi_t safi, u_char type, struct prefix *p,
        si->prev = pp;
        si->next = cp;
 
-       /* Install into rib. */
-       static_install_route(afi, safi, p, src_p, si);
+       /* check whether interface exists in system & install if it does */
+       if (!ifname)
+               static_install_route(afi, safi, p, src_p, si);
+       else {
+               struct interface *ifp;
+
+               ifp = if_lookup_by_name(ifname, zvrf_id(zvrf));
+               if (ifp && ifp->ifindex != IFINDEX_INTERNAL) {
+                       si->ifindex = ifp->ifindex;
+                       static_install_route(afi, safi, p, src_p, si);
+               }
+       }
 
        return 1;
 }
 
 int static_delete_route(afi_t afi, safi_t safi, u_char type, struct prefix *p,
                        struct prefix_ipv6 *src_p, union g_addr *gate,
-                       ifindex_t ifindex, route_tag_t tag, u_char distance,
+                       const char *ifname, route_tag_t tag, u_char distance,
                        struct zebra_vrf *zvrf,
                        struct static_nh_label *snh_label)
 {
@@ -504,7 +518,7 @@ int static_delete_route(afi_t afi, safi_t safi, u_char type, struct prefix *p,
                                   && IPV4_ADDR_SAME(gate, &si->addr.ipv4))
                                  || (afi == AFI_IP6
                                      && IPV6_ADDR_SAME(gate, &si->addr.ipv6))))
-                   && (!ifindex || ifindex == si->ifindex)
+                   && (!strcmp(ifname ? ifname : "", si->ifname))
                    && (!tag || (tag == si->tag))
                    && (!snh_label->num_labels
                        || !memcmp(&si->snh_label, snh_label,
@@ -517,8 +531,9 @@ int static_delete_route(afi_t afi, safi_t safi, u_char type, struct prefix *p,
                return 0;
        }
 
-       /* Install into rib. */
-       static_uninstall_route(afi, safi, p, src_p, si);
+       /* Uninstall from rib. */
+       if (!si->ifname[0] || si->ifindex != IFINDEX_INTERNAL)
+               static_uninstall_route(afi, safi, p, src_p, si);
 
        /* Unlink static route from linked list. */
        if (si->prev)
@@ -536,3 +551,49 @@ int static_delete_route(afi_t afi, safi_t safi, u_char type, struct prefix *p,
 
        return 1;
 }
+
+static void static_ifindex_update_af(struct interface *ifp, bool up,
+                                    afi_t afi, safi_t safi)
+{
+       struct route_table *stable;
+       struct zebra_vrf *zvrf = zebra_vrf_lookup_by_id(ifp->vrf_id);
+       struct route_node *rn;
+       struct static_route *si;
+       struct prefix *p, *src_pp;
+       struct prefix_ipv6 *src_p;
+
+       stable = zebra_vrf_static_table(afi, safi, zvrf);
+       if (!stable)
+               return;
+
+       for (rn = route_top(stable); rn; rn = srcdest_route_next(rn)) {
+               srcdest_rnode_prefixes(rn, &p, &src_pp);
+               src_p = (struct prefix_ipv6 *)src_pp;
+
+               for (si = rn->info; si; si = si->next) {
+                       if (!si->ifname[0])
+                               continue;
+                       if (up) {
+                               if (strcmp(si->ifname, ifp->name))
+                                       continue;
+                               si->ifindex = ifp->ifindex;
+                               static_install_route(afi, safi, p, src_p, si);
+                       } else {
+                               if (si->ifindex != ifp->ifindex)
+                                       continue;
+                               static_uninstall_route(afi, safi, p, src_p,
+                                                      si);
+                               si->ifindex = IFINDEX_INTERNAL;
+                       }
+               }
+       }
+}
+
+/* called from if_{add,delete}_update, i.e. when ifindex becomes [in]valid */
+void static_ifindex_update(struct interface *ifp, bool up)
+{
+       static_ifindex_update_af(ifp, up, AFI_IP, SAFI_UNICAST);
+       static_ifindex_update_af(ifp, up, AFI_IP, SAFI_MULTICAST);
+       static_ifindex_update_af(ifp, up, AFI_IP6, SAFI_UNICAST);
+       static_ifindex_update_af(ifp, up, AFI_IP6, SAFI_MULTICAST);
+}

diff --git a/zebra/zebra_static.h b/zebra/zebra_static.h
index 520adb1e41dc3a2be02d96b2d15205e082a579fa..6ab47094a1498d545c2a7a3319d881a9ae043a68 100644 (file)
--- a/zebra/zebra_static.h
+++ b/zebra/zebra_static.h
@@ -84,16 +84,18 @@ extern void static_uninstall_route(afi_t afi, safi_t safi, struct prefix *p,
 
 extern int static_add_route(afi_t, safi_t safi, u_char type, struct prefix *p,
                            struct prefix_ipv6 *src_p, union g_addr *gate,
-                           ifindex_t ifindex, const char *ifname, u_char flags,
+                           const char *ifname, u_char flags,
                            route_tag_t tag, u_char distance,
                            struct zebra_vrf *zvrf,
                            struct static_nh_label *snh_label);
 
 extern int static_delete_route(afi_t, safi_t safi, u_char type,
                               struct prefix *p, struct prefix_ipv6 *src_p,
-                              union g_addr *gate, ifindex_t ifindex,
+                              union g_addr *gate, const char *ifname,
                               route_tag_t tag, u_char distance,
                               struct zebra_vrf *zvrf,
                               struct static_nh_label *snh_label);
 
+extern void static_ifindex_update(struct interface *ifp, bool up);
+
 #endif

diff --git a/zebra/zebra_vty.c b/zebra/zebra_vty.c
index d167e7d271c4c8544605710f7c7a8dcc792d7676..00d0f3e5a4b2432612532471fad351e5e7706205 100644 (file)
--- a/zebra/zebra_vty.c
+++ b/zebra/zebra_vty.c
@@ -80,7 +80,6 @@ static int zebra_static_route(struct vty *vty, afi_t afi, safi_t safi,
        u_char flag = 0;
        route_tag_t tag = 0;
        struct zebra_vrf *zvrf;
-       unsigned int ifindex = 0;
        u_char type;
        struct static_nh_label snh_label;
 
@@ -207,17 +206,6 @@ static int zebra_static_route(struct vty *vty, afi_t afi, safi_t safi,
                gatep = &gate;
        }
 
-       if (ifname) {
-               struct interface *ifp;
-               ifp = if_lookup_by_name(ifname, zvrf_id(zvrf));
-               if (!ifp) {
-                       vty_out(vty, "%% Malformed Interface name %s\n",
-                               ifname);
-                       ifindex = IFINDEX_DELETED;
-               } else
-                       ifindex = ifp->ifindex;
-       }
-
        if (gate_str == NULL && ifname == NULL)
                type = STATIC_BLACKHOLE;
        else if (gate_str && ifname) {
@@ -235,10 +223,10 @@ static int zebra_static_route(struct vty *vty, afi_t afi, safi_t safi,
        }
 
        if (!negate)
-               static_add_route(afi, safi, type, &p, src_p, gatep, ifindex,
-                                ifname, flag, tag, distance, zvrf, &snh_label);
+               static_add_route(afi, safi, type, &p, src_p, gatep, ifname,
+                                   flag, tag, distance, zvrf, &snh_label);
        else
-               static_delete_route(afi, safi, type, &p, src_p, gatep, ifindex,
+               static_delete_route(afi, safi, type, &p, src_p, gatep, ifname,
                                    tag, distance, zvrf, &snh_label);
 
        return CMD_SUCCESS;