zebra: Fix ships in the night issue

When using wait for install there exists situations where
zebra will issue several route change operations to the kernel
but end up in a state where we shouldn't be at the end
due to extra data being received.  Example:

a) zebra receives from bgp a route change, installs sends the
route to the kernel.
b) zebra receives a route deletion from bgp, removes the
struct route entry and then sends to the kernel a deletion.
c) zebra receives an asynchronous notification that (a) succeeded
but we treat this as a new route.

This is the ships in the night problem.  In this case if we receive
notification from the kernel about a route that we know nothing
about and we are not in startup and we are doing asic offload
then we can ignore this update.

Ticket: #2563300
Signed-off-by: Donald Sharp <sharpd@nvidia.com>

diff --git a/zebra/connected.c b/zebra/connected.c
index b261ddb7914de009b27ad483ba136ea6826e7161..4f4e8be34b77649520d1f63c53f5eeb42deb14a6 100644 (file)
--- a/zebra/connected.c
+++ b/zebra/connected.c
@@ -290,10 +290,12 @@ void connected_up(struct interface *ifp, struct connected *ifc)
        }
 
        rib_add(afi, SAFI_UNICAST, zvrf->vrf->vrf_id, ZEBRA_ROUTE_CONNECT, 0,
-               flags, &p, NULL, &nh, 0, zvrf->table_id, metric, 0, 0, 0);
+               flags, &p, NULL, &nh, 0, zvrf->table_id, metric, 0, 0, 0,
+               false);
 
        rib_add(afi, SAFI_MULTICAST, zvrf->vrf->vrf_id, ZEBRA_ROUTE_CONNECT, 0,
-               flags, &p, NULL, &nh, 0, zvrf->table_id, metric, 0, 0, 0);
+               flags, &p, NULL, &nh, 0, zvrf->table_id, metric, 0, 0, 0,
+               false);
 
        /* Schedule LSP forwarding entries for processing, if appropriate. */
        if (zvrf->vrf->vrf_id == VRF_DEFAULT) {

diff --git a/zebra/kernel_socket.c b/zebra/kernel_socket.c
index 5ff66f7c63371a8aa9c73d0999e633cef44e610c..3c9d203a0b034658c1592d5fedd391c2f8075365 100644 (file)
--- a/zebra/kernel_socket.c
+++ b/zebra/kernel_socket.c
@@ -1113,7 +1113,7 @@ void rtm_read(struct rt_msghdr *rtm)
            || rtm->rtm_type == RTM_CHANGE)
                rib_add(afi, SAFI_UNICAST, VRF_DEFAULT, ZEBRA_ROUTE_KERNEL, 0,
                        zebra_flags, &p, NULL, &nh, 0, RT_TABLE_MAIN,
-                       0, 0, 0, 0);
+                       0, 0, 0, 0, false);
        else
                rib_delete(afi, SAFI_UNICAST, VRF_DEFAULT, ZEBRA_ROUTE_KERNEL,
                           0, zebra_flags, &p, NULL, &nh, 0, RT_TABLE_MAIN, 0,

diff --git a/zebra/redistribute.c b/zebra/redistribute.c
index fdd2c8405f4937c169fbd4fd1089ecf934d6a8e0..1a28f8ceec089669ed6f3d2added70f5229a6bf4 100644 (file)
--- a/zebra/redistribute.c
+++ b/zebra/redistribute.c
@@ -698,7 +698,7 @@ int zebra_add_import_table_entry(struct zebra_vrf *zvrf, struct route_node *rn,
        ng = nexthop_group_new();
        copy_nexthops(&ng->nexthop, re->nhe->nhg.nexthop, NULL);
 
-       rib_add_multipath(afi, SAFI_UNICAST, &p, NULL, newre, ng);
+       rib_add_multipath(afi, SAFI_UNICAST, &p, NULL, newre, ng, false);
 
        return 0;
 }

diff --git a/zebra/rib.h b/zebra/rib.h
index c1aeb7f07e2844a3c7277e9ab2a90704c2f4c8d7..ae1fce727c713a1b4abb7ee706be97b411fccf4d 100644 (file)
--- a/zebra/rib.h
+++ b/zebra/rib.h
@@ -394,13 +394,14 @@ extern int rib_add(afi_t afi, safi_t safi, vrf_id_t vrf_id, int type,
                   unsigned short instance, uint32_t flags, struct prefix *p,
                   struct prefix_ipv6 *src_p, const struct nexthop *nh,
                   uint32_t nhe_id, uint32_t table_id, uint32_t metric,
-                  uint32_t mtu, uint8_t distance, route_tag_t tag);
+                  uint32_t mtu, uint8_t distance, route_tag_t tag,
+                  bool startup);
 /*
  * Multipath route apis.
  */
 extern int rib_add_multipath(afi_t afi, safi_t safi, struct prefix *p,
                             struct prefix_ipv6 *src_p, struct route_entry *re,
-                            struct nexthop_group *ng);
+                            struct nexthop_group *ng, bool startup);
 /*
  * -1 -> some sort of error
  *  0 -> an add
@@ -409,7 +410,7 @@ extern int rib_add_multipath(afi_t afi, safi_t safi, struct prefix *p,
 extern int rib_add_multipath_nhe(afi_t afi, safi_t safi, struct prefix *p,
                                 struct prefix_ipv6 *src_p,
                                 struct route_entry *re,
-                                struct nhg_hash_entry *nhe);
+                                struct nhg_hash_entry *nhe, bool startup);
 
 extern void rib_delete(afi_t afi, safi_t safi, vrf_id_t vrf_id, int type,
                       unsigned short instance, uint32_t flags,

diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c
index 2d12ad4c8e619370d6a164b87a107df403519999..8f3e066d44673f711ce69905a7c50669f9067ad6 100644 (file)
--- a/zebra/rt_netlink.c
+++ b/zebra/rt_netlink.c
@@ -920,7 +920,7 @@ static int netlink_route_change_read_unicast(struct nlmsghdr *h, ns_id_t ns_id,
                        }
                        rib_add(afi, SAFI_UNICAST, vrf_id, proto, 0, flags, &p,
                                &src_p, &nh, nhe_id, table, metric, mtu,
-                               distance, tag);
+                               distance, tag, startup);
                } else {
                        /* This is a multipath route */
                        struct route_entry *re;
@@ -964,7 +964,7 @@ static int netlink_route_change_read_unicast(struct nlmsghdr *h, ns_id_t ns_id,
 
                        if (nhe_id || ng)
                                rib_add_multipath(afi, SAFI_UNICAST, &p,
-                                                 &src_p, re, ng);
+                                                 &src_p, re, ng, startup);
                        else
                                XFREE(MTYPE_RE, re);
                }

diff --git a/zebra/zapi_msg.c b/zebra/zapi_msg.c
index b69200d96c2042d4a52083eefd7bdd5356d0b551..1b6f37ec6a4c48c436ae4d3a66d020b697fb984f 100644 (file)
--- a/zebra/zapi_msg.c
+++ b/zebra/zapi_msg.c
@@ -2127,7 +2127,7 @@ static void zread_route_add(ZAPI_HANDLER_ARGS)
                nhe.backup_info = bnhg;
        }
        ret = rib_add_multipath_nhe(afi, api.safi, &api.prefix, src_p,
-                                   re, &nhe);
+                                   re, &nhe, false);
 
        /*
         * rib_add_multipath_nhe only fails in a couple spots

diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c
index fbd3c6eb77393baaf4f473eece29bb7094c9bbdd..cfa2a20bb8d060b063744bcbb2ed958f15014134 100644 (file)
--- a/zebra/zebra_rib.c
+++ b/zebra/zebra_rib.c
@@ -3346,7 +3346,7 @@ void _route_entry_dump(const char *func, union prefixconstptr pp,
  */
 int rib_add_multipath_nhe(afi_t afi, safi_t safi, struct prefix *p,
                          struct prefix_ipv6 *src_p, struct route_entry *re,
-                         struct nhg_hash_entry *re_nhe)
+                         struct nhg_hash_entry *re_nhe, bool startup)
 {
        struct nhg_hash_entry *nhe = NULL;
        struct route_table *table;
@@ -3438,6 +3438,32 @@ int rib_add_multipath_nhe(afi_t afi, safi_t safi, struct prefix *p,
 
        same = first_same;
 
+       if (!startup &&
+           (re->flags & ZEBRA_FLAG_SELFROUTE) && zrouter.asic_offloaded) {
+               if (!same) {
+                       if (IS_ZEBRA_DEBUG_RIB)
+                               zlog_debug("prefix: %pRN is a self route where we do not have an entry for it.  Dropping this update, it's useless", rn);
+                       /*
+                        * We are not on startup, this is a self route
+                        * and we have asic offload.  Which means
+                        * we are getting a callback for a entry
+                        * that was already deleted to the kernel
+                        * but an earlier response was just handed
+                        * back.  Drop it on the floor
+                        */
+                       if (re->nhe && re->nhe_id) {
+                               assert(re->nhe->id == re->nhe_id);
+                               route_entry_update_nhe(re, NULL);
+                       } else if (re->nhe && re->nhe->nhg.nexthop)
+                               nexthops_free(re->nhe->nhg.nexthop);
+
+                       nexthops_free(re->fib_ng.nexthop);
+
+                       XFREE(MTYPE_RE, re);
+                       return ret;
+               }
+       }
+
        /* If this route is kernel/connected route, notify the dataplane. */
        if (RIB_SYSTEM_ROUTE(re)) {
                /* Notify dataplane */
@@ -3491,7 +3517,7 @@ int rib_add_multipath_nhe(afi_t afi, safi_t safi, struct prefix *p,
  */
 int rib_add_multipath(afi_t afi, safi_t safi, struct prefix *p,
                      struct prefix_ipv6 *src_p, struct route_entry *re,
-                     struct nexthop_group *ng)
+                     struct nexthop_group *ng, bool startup)
 {
        int ret;
        struct nhg_hash_entry nhe;
@@ -3512,7 +3538,7 @@ int rib_add_multipath(afi_t afi, safi_t safi, struct prefix *p,
        else if (re->nhe_id > 0)
                nhe.id = re->nhe_id;
 
-       ret = rib_add_multipath_nhe(afi, safi, p, src_p, re, &nhe);
+       ret = rib_add_multipath_nhe(afi, safi, p, src_p, re, &nhe, startup);
 
        /* In this path, the callers expect memory to be freed. */
        nexthop_group_delete(&ng);
@@ -3743,7 +3769,7 @@ int rib_add(afi_t afi, safi_t safi, vrf_id_t vrf_id, int type,
            unsigned short instance, uint32_t flags, struct prefix *p,
            struct prefix_ipv6 *src_p, const struct nexthop *nh,
            uint32_t nhe_id, uint32_t table_id, uint32_t metric, uint32_t mtu,
-           uint8_t distance, route_tag_t tag)
+           uint8_t distance, route_tag_t tag, bool startup)
 {
        struct route_entry *re = NULL;
        struct nexthop *nexthop = NULL;
@@ -3775,7 +3801,7 @@ int rib_add(afi_t afi, safi_t safi, vrf_id_t vrf_id, int type,
                nexthop_group_add_sorted(ng, nexthop);
        }
 
-       return rib_add_multipath(afi, safi, p, src_p, re, ng);
+       return rib_add_multipath(afi, safi, p, src_p, re, ng, startup);
 }
 
 static const char *rib_update_event2str(enum rib_update_event event)