zebra: reject routes without nexthops

Routes without nexthops don't make any sense, so we need to reject
them otherwise weird things can happen.

NOTE: blackhole routes aren't nexthop-less, they do have a single
nexthop of type NEXTHOP_TYPE_BLACKHOLE.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

diff --git a/zebra/zapi_msg.c b/zebra/zapi_msg.c
index 8fe7031abe0a6cf3a4e1a445d3e20b770143b49b..f049a8d1a203f2bba2c75a2fe4f3fa33538eb2c5 100644 (file)
--- a/zebra/zapi_msg.c
+++ b/zebra/zapi_msg.c
@@ -1395,147 +1395,150 @@ static void zread_route_add(ZAPI_HANDLER_ARGS)
        else
                re->table = zvrf->table_id;
 
+       if (!CHECK_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP)
+           || api.nexthop_num == 0) {
+               char buf_prefix[PREFIX_STRLEN];
+
+               prefix2str(&api.prefix, buf_prefix, sizeof(buf_prefix));
+               flog_warn(EC_ZEBRA_RX_ROUTE_NO_NEXTHOPS,
+                         "%s: received a route without nexthops for prefix %s",
+                         __func__, buf_prefix);
+               XFREE(MTYPE_RE, re);
+               return;
+       }
+
        /*
         * TBD should _all_ of the nexthop add operations use
         * api_nh->vrf_id instead of re->vrf_id ? I only changed
         * for cases NEXTHOP_TYPE_IPV4 and NEXTHOP_TYPE_IPV6.
         */
-       if (CHECK_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP))
-               for (i = 0; i < api.nexthop_num; i++) {
-                       api_nh = &api.nexthops[i];
-                       ifindex_t ifindex = 0;
-
-                       if (IS_ZEBRA_DEBUG_RECV)
-                               zlog_debug("nh type %d", api_nh->type);
-
-                       switch (api_nh->type) {
-                       case NEXTHOP_TYPE_IFINDEX:
-                               nexthop = route_entry_nexthop_ifindex_add(
-                                       re, api_nh->ifindex, api_nh->vrf_id);
-                               break;
-                       case NEXTHOP_TYPE_IPV4:
-                               if (IS_ZEBRA_DEBUG_RECV) {
-                                       char nhbuf[INET6_ADDRSTRLEN] = {0};
-
-                                       inet_ntop(AF_INET, &api_nh->gate.ipv4,
-                                                 nhbuf, INET6_ADDRSTRLEN);
-                                       zlog_debug("%s: nh=%s, vrf_id=%d",
-                                                  __func__, nhbuf,
-                                                  api_nh->vrf_id);
-                               }
-                               nexthop = route_entry_nexthop_ipv4_add(
-                                       re, &api_nh->gate.ipv4, NULL,
-                                       api_nh->vrf_id);
-                               break;
-                       case NEXTHOP_TYPE_IPV4_IFINDEX:
-
-                               memset(&vtep_ip, 0, sizeof(struct ipaddr));
-                               if (CHECK_FLAG(api.flags,
-                                              ZEBRA_FLAG_EVPN_ROUTE)) {
-                                       ifindex = get_l3vni_svi_ifindex(vrf_id);
-                               } else {
-                                       ifindex = api_nh->ifindex;
-                               }
-
-                               if (IS_ZEBRA_DEBUG_RECV) {
-                                       char nhbuf[INET6_ADDRSTRLEN] = {0};
-
-                                       inet_ntop(AF_INET, &api_nh->gate.ipv4,
-                                                 nhbuf, INET6_ADDRSTRLEN);
-                                       zlog_debug(
-                                               "%s: nh=%s, vrf_id=%d (re->vrf_id=%d), ifindex=%d",
-                                               __func__, nhbuf, api_nh->vrf_id,
-                                               re->vrf_id, ifindex);
-                               }
-                               nexthop = route_entry_nexthop_ipv4_ifindex_add(
-                                       re, &api_nh->gate.ipv4, NULL, ifindex,
-                                       api_nh->vrf_id);
-
-                               /* if this an EVPN route entry,
-                                * program the nh as neigh
-                                */
-                               if (CHECK_FLAG(api.flags,
-                                              ZEBRA_FLAG_EVPN_ROUTE)) {
-                                       SET_FLAG(nexthop->flags,
-                                                NEXTHOP_FLAG_EVPN_RVTEP);
-                                       vtep_ip.ipa_type = IPADDR_V4;
-                                       memcpy(&(vtep_ip.ipaddr_v4),
-                                              &(api_nh->gate.ipv4),
-                                              sizeof(struct in_addr));
-                                       zebra_vxlan_evpn_vrf_route_add(
-                                               vrf_id, &api_nh->rmac, &vtep_ip,
-                                               &api.prefix);
-                               }
-                               break;
-                       case NEXTHOP_TYPE_IPV6:
-                               nexthop = route_entry_nexthop_ipv6_add(
-                                       re, &api_nh->gate.ipv6, api_nh->vrf_id);
-                               break;
-                       case NEXTHOP_TYPE_IPV6_IFINDEX:
-                               memset(&vtep_ip, 0, sizeof(struct ipaddr));
-                               if (CHECK_FLAG(api.flags,
-                                              ZEBRA_FLAG_EVPN_ROUTE)) {
-                                       ifindex = get_l3vni_svi_ifindex(vrf_id);
-                               } else {
-                                       ifindex = api_nh->ifindex;
-                               }
-
-                               nexthop = route_entry_nexthop_ipv6_ifindex_add(
-                                       re, &api_nh->gate.ipv6, ifindex,
-                                       api_nh->vrf_id);
-
-                               /* if this an EVPN route entry,
-                                * program the nh as neigh
-                                */
-                               if (CHECK_FLAG(api.flags,
-                                              ZEBRA_FLAG_EVPN_ROUTE)) {
-                                       SET_FLAG(nexthop->flags,
-                                                NEXTHOP_FLAG_EVPN_RVTEP);
-                                       vtep_ip.ipa_type = IPADDR_V6;
-                                       memcpy(&vtep_ip.ipaddr_v6,
-                                              &(api_nh->gate.ipv6),
-                                              sizeof(struct in6_addr));
-                                       zebra_vxlan_evpn_vrf_route_add(
-                                               vrf_id, &api_nh->rmac, &vtep_ip,
-                                               &api.prefix);
-                               }
-                               break;
-                       case NEXTHOP_TYPE_BLACKHOLE:
-                               nexthop = route_entry_nexthop_blackhole_add(
-                                       re, api_nh->bh_type);
-                               break;
+       for (i = 0; i < api.nexthop_num; i++) {
+               api_nh = &api.nexthops[i];
+               ifindex_t ifindex = 0;
+
+               if (IS_ZEBRA_DEBUG_RECV)
+                       zlog_debug("nh type %d", api_nh->type);
+
+               switch (api_nh->type) {
+               case NEXTHOP_TYPE_IFINDEX:
+                       nexthop = route_entry_nexthop_ifindex_add(
+                               re, api_nh->ifindex, api_nh->vrf_id);
+                       break;
+               case NEXTHOP_TYPE_IPV4:
+                       if (IS_ZEBRA_DEBUG_RECV) {
+                               char nhbuf[INET6_ADDRSTRLEN] = {0};
+
+                               inet_ntop(AF_INET, &api_nh->gate.ipv4, nhbuf,
+                                         INET6_ADDRSTRLEN);
+                               zlog_debug("%s: nh=%s, vrf_id=%d", __func__,
+                                          nhbuf, api_nh->vrf_id);
                        }
+                       nexthop = route_entry_nexthop_ipv4_add(
+                               re, &api_nh->gate.ipv4, NULL, api_nh->vrf_id);
+                       break;
+               case NEXTHOP_TYPE_IPV4_IFINDEX:
 
-                       if (!nexthop) {
-                               flog_warn(
-                                       EC_ZEBRA_NEXTHOP_CREATION_FAILED,
-                                       "%s: Nexthops Specified: %d but we failed to properly create one",
-                                       __PRETTY_FUNCTION__, api.nexthop_num);
-                               nexthops_free(re->ng.nexthop);
-                               XFREE(MTYPE_RE, re);
-                               return;
+                       memset(&vtep_ip, 0, sizeof(struct ipaddr));
+                       if (CHECK_FLAG(api.flags, ZEBRA_FLAG_EVPN_ROUTE)) {
+                               ifindex = get_l3vni_svi_ifindex(vrf_id);
+                       } else {
+                               ifindex = api_nh->ifindex;
                        }
-                       /* MPLS labels for BGP-LU or Segment Routing */
-                       if (CHECK_FLAG(api.message, ZAPI_MESSAGE_LABEL)
-                           && api_nh->type != NEXTHOP_TYPE_IFINDEX
-                           && api_nh->type != NEXTHOP_TYPE_BLACKHOLE) {
-                               enum lsp_types_t label_type;
-
-                               label_type =
-                                       lsp_type_from_re_type(client->proto);
-
-                               if (IS_ZEBRA_DEBUG_RECV) {
-                                       zlog_debug(
-                                               "%s: adding %d labels of type %d (1st=%u)",
-                                               __func__, api_nh->label_num,
-                                               label_type, api_nh->labels[0]);
-                               }
-
-                               nexthop_add_labels(nexthop, label_type,
-                                                  api_nh->label_num,
-                                                  &api_nh->labels[0]);
+
+                       if (IS_ZEBRA_DEBUG_RECV) {
+                               char nhbuf[INET6_ADDRSTRLEN] = {0};
+
+                               inet_ntop(AF_INET, &api_nh->gate.ipv4, nhbuf,
+                                         INET6_ADDRSTRLEN);
+                               zlog_debug(
+                                       "%s: nh=%s, vrf_id=%d (re->vrf_id=%d), ifindex=%d",
+                                       __func__, nhbuf, api_nh->vrf_id,
+                                       re->vrf_id, ifindex);
+                       }
+                       nexthop = route_entry_nexthop_ipv4_ifindex_add(
+                               re, &api_nh->gate.ipv4, NULL, ifindex,
+                               api_nh->vrf_id);
+
+                       /* if this an EVPN route entry,
+                        * program the nh as neigh
+                        */
+                       if (CHECK_FLAG(api.flags, ZEBRA_FLAG_EVPN_ROUTE)) {
+                               SET_FLAG(nexthop->flags,
+                                        NEXTHOP_FLAG_EVPN_RVTEP);
+                               vtep_ip.ipa_type = IPADDR_V4;
+                               memcpy(&(vtep_ip.ipaddr_v4),
+                                      &(api_nh->gate.ipv4),
+                                      sizeof(struct in_addr));
+                               zebra_vxlan_evpn_vrf_route_add(
+                                       vrf_id, &api_nh->rmac, &vtep_ip,
+                                       &api.prefix);
+                       }
+                       break;
+               case NEXTHOP_TYPE_IPV6:
+                       nexthop = route_entry_nexthop_ipv6_add(
+                               re, &api_nh->gate.ipv6, api_nh->vrf_id);
+                       break;
+               case NEXTHOP_TYPE_IPV6_IFINDEX:
+                       memset(&vtep_ip, 0, sizeof(struct ipaddr));
+                       if (CHECK_FLAG(api.flags, ZEBRA_FLAG_EVPN_ROUTE)) {
+                               ifindex = get_l3vni_svi_ifindex(vrf_id);
+                       } else {
+                               ifindex = api_nh->ifindex;
+                       }
+
+                       nexthop = route_entry_nexthop_ipv6_ifindex_add(
+                               re, &api_nh->gate.ipv6, ifindex,
+                               api_nh->vrf_id);
+
+                       /* if this an EVPN route entry,
+                        * program the nh as neigh
+                        */
+                       if (CHECK_FLAG(api.flags, ZEBRA_FLAG_EVPN_ROUTE)) {
+                               SET_FLAG(nexthop->flags,
+                                        NEXTHOP_FLAG_EVPN_RVTEP);
+                               vtep_ip.ipa_type = IPADDR_V6;
+                               memcpy(&vtep_ip.ipaddr_v6, &(api_nh->gate.ipv6),
+                                      sizeof(struct in6_addr));
+                               zebra_vxlan_evpn_vrf_route_add(
+                                       vrf_id, &api_nh->rmac, &vtep_ip,
+                                       &api.prefix);
                        }
+                       break;
+               case NEXTHOP_TYPE_BLACKHOLE:
+                       nexthop = route_entry_nexthop_blackhole_add(
+                               re, api_nh->bh_type);
+                       break;
+               }
+
+               if (!nexthop) {
+                       flog_warn(
+                               EC_ZEBRA_NEXTHOP_CREATION_FAILED,
+                               "%s: Nexthops Specified: %d but we failed to properly create one",
+                               __PRETTY_FUNCTION__, api.nexthop_num);
+                       nexthops_free(re->ng.nexthop);
+                       XFREE(MTYPE_RE, re);
+                       return;
                }
+               /* MPLS labels for BGP-LU or Segment Routing */
+               if (CHECK_FLAG(api.message, ZAPI_MESSAGE_LABEL)
+                   && api_nh->type != NEXTHOP_TYPE_IFINDEX
+                   && api_nh->type != NEXTHOP_TYPE_BLACKHOLE) {
+                       enum lsp_types_t label_type;
+
+                       label_type = lsp_type_from_re_type(client->proto);
+
+                       if (IS_ZEBRA_DEBUG_RECV) {
+                               zlog_debug(
+                                       "%s: adding %d labels of type %d (1st=%u)",
+                                       __func__, api_nh->label_num, label_type,
+                                       api_nh->labels[0]);
+                       }
+
+                       nexthop_add_labels(nexthop, label_type,
+                                          api_nh->label_num,
+                                          &api_nh->labels[0]);
+               }
+       }
 
        if (CHECK_FLAG(api.message, ZAPI_MESSAGE_DISTANCE))
                re->distance = api.distance;

diff --git a/zebra/zebra_errors.c b/zebra/zebra_errors.c
index d7c17829cdc61b61349fd1e91efceccf8af149c3..cb5f30df1f0657694e500ec8ba285f4a14125a02 100644 (file)
--- a/zebra/zebra_errors.c
+++ b/zebra/zebra_errors.c
@@ -504,6 +504,15 @@ static struct log_ref ferr_zebra_err[] = {
                .suggestion =
                        "Check configuration values for correctness. If they are correct, report this as a bug.",
        },
+       {
+               .code = EC_ZEBRA_RX_ROUTE_NO_NEXTHOPS,
+               .title =
+                       "Zebra received an installation request for a route without nexthops",
+               .description =
+                       "Zebra received a message from a client requesting a route installation, but the route is invalid since it doesn't have any nexthop address or interface.",
+               .suggestion =
+                       "This is a bug; please report it.",
+       },
        {
                .code = EC_ZEBRA_RX_SRCDEST_WRONG_AFI,
                .title =

diff --git a/zebra/zebra_errors.h b/zebra/zebra_errors.h
index c3cdc4ed421757e87df91e95d20d49565a0fe6a1..0af5f8a5514ac57a7662590c50d40a82d2dc1f9e 100644 (file)
--- a/zebra/zebra_errors.h
+++ b/zebra/zebra_errors.h
@@ -96,6 +96,7 @@ enum zebra_log_refs {
        EC_ZEBRA_VRF_NOT_FOUND,
        EC_ZEBRA_MORE_NH_THAN_MULTIPATH,
        EC_ZEBRA_NEXTHOP_CREATION_FAILED,
+       EC_ZEBRA_RX_ROUTE_NO_NEXTHOPS,
        EC_ZEBRA_RX_SRCDEST_WRONG_AFI,
        EC_ZEBRA_PSEUDOWIRE_EXISTS,
        EC_ZEBRA_PSEUDOWIRE_UNINSTALL_NOT_FOUND,