From: karthik-kc <[email protected]> Physical switches have the ability to specify "discard" or sometimes "NULL interface" as a nexthop for routes. This can be used to prevent routing loops in the network. Add a similar configuration for ovn where nexthop accepts the string "discard". When the nexthop is discard the action in the routing table will be to drop the packets.
Signed-off-by: Karthik Chandrashekar <[email protected]> --- northd/ovn-northd.c | 126 +++++++++++++++++++++++------------------- ovn-nb.xml | 4 +- tests/ovn-nbctl.at | 13 +++++ tests/ovn.at | 93 +++++++++++++++++++++++++++++++ utilities/ovn-nbctl.c | 50 ++++++++++++----- 5 files changed, 215 insertions(+), 71 deletions(-) diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c index 39d798782..18d0e0b43 100644 --- a/northd/ovn-northd.c +++ b/northd/ovn-northd.c @@ -7749,6 +7749,7 @@ struct parsed_route { uint32_t hash; const struct nbrec_logical_router_static_route *route; bool ecmp_symmetric_reply; + bool is_discard_route; }; static uint32_t @@ -7768,20 +7769,23 @@ parsed_routes_add(struct ovs_list *routes, /* Verify that the next hop is an IP address with an all-ones mask. */ struct in6_addr nexthop; unsigned int plen; - if (!ip46_parse_cidr(route->nexthop, &nexthop, &plen)) { - static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1); - VLOG_WARN_RL(&rl, "bad 'nexthop' %s in static route" - UUID_FMT, route->nexthop, - UUID_ARGS(&route->header_.uuid)); - return NULL; - } - if ((IN6_IS_ADDR_V4MAPPED(&nexthop) && plen != 32) || - (!IN6_IS_ADDR_V4MAPPED(&nexthop) && plen != 128)) { - static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1); - VLOG_WARN_RL(&rl, "bad next hop mask %s in static route" - UUID_FMT, route->nexthop, - UUID_ARGS(&route->header_.uuid)); - return NULL; + bool is_discard_route = !strcmp(route->nexthop, "discard"); + if (!is_discard_route) { + if (!ip46_parse_cidr(route->nexthop, &nexthop, &plen)) { + static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1); + VLOG_WARN_RL(&rl, "bad 'nexthop' %s in static route" + UUID_FMT, route->nexthop, + UUID_ARGS(&route->header_.uuid)); + return NULL; + } + if ((IN6_IS_ADDR_V4MAPPED(&nexthop) && plen != 32) || + (!IN6_IS_ADDR_V4MAPPED(&nexthop) && plen != 128)) { + static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1); + VLOG_WARN_RL(&rl, "bad next hop mask %s in static route" + UUID_FMT, route->nexthop, + UUID_ARGS(&route->header_.uuid)); + return NULL; + } } /* Parse ip_prefix */ @@ -7795,13 +7799,15 @@ parsed_routes_add(struct ovs_list *routes, } /* Verify that ip_prefix and nexthop have same address familiy. */ - if (IN6_IS_ADDR_V4MAPPED(&prefix) != IN6_IS_ADDR_V4MAPPED(&nexthop)) { - static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1); - VLOG_WARN_RL(&rl, "Address family doesn't match between 'ip_prefix' %s" - " and 'nexthop' %s in static route"UUID_FMT, - route->ip_prefix, route->nexthop, - UUID_ARGS(&route->header_.uuid)); - return NULL; + if (!is_discard_route) { + if (IN6_IS_ADDR_V4MAPPED(&prefix) != IN6_IS_ADDR_V4MAPPED(&nexthop)) { + static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1); + VLOG_WARN_RL(&rl, "Address family doesn't match between 'ip_prefix' %s" + " and 'nexthop' %s in static route"UUID_FMT, + route->ip_prefix, route->nexthop, + UUID_ARGS(&route->header_.uuid)); + return NULL; + } } const struct nbrec_bfd *nb_bt = route->bfd; @@ -7832,6 +7838,7 @@ parsed_routes_add(struct ovs_list *routes, pr->route = route; pr->ecmp_symmetric_reply = smap_get_bool(&route->options, "ecmp_symmetric_reply", false); + pr->is_discard_route = is_discard_route; ovs_list_insert(routes, &pr->list_node); return pr; } @@ -8244,10 +8251,11 @@ build_ecmp_route_flow(struct hmap *lflows, struct ovn_datapath *od, } static void -add_route(struct hmap *lflows, const struct ovn_port *op, - const char *lrp_addr_s, const char *network_s, int plen, - const char *gateway, bool is_src_route, - const struct ovsdb_idl_row *stage_hint) +add_route(struct hmap *lflows, struct ovn_datapath *od, + const struct ovn_port *op, const char *lrp_addr_s, + const char *network_s, int plen, const char *gateway, + bool is_src_route, const struct ovsdb_idl_row *stage_hint, + bool is_discard_route) { bool is_ipv4 = strchr(network_s, '.') ? true : false; struct ds match = DS_EMPTY_INITIALIZER; @@ -8266,30 +8274,34 @@ add_route(struct hmap *lflows, const struct ovn_port *op, &match, &priority); struct ds common_actions = DS_EMPTY_INITIALIZER; - ds_put_format(&common_actions, REG_ECMP_GROUP_ID" = 0; %s = ", - is_ipv4 ? REG_NEXT_HOP_IPV4 : REG_NEXT_HOP_IPV6); - if (gateway) { - ds_put_cstr(&common_actions, gateway); - } else { - ds_put_format(&common_actions, "ip%s.dst", is_ipv4 ? "4" : "6"); - } - ds_put_format(&common_actions, "; " - "%s = %s; " - "eth.src = %s; " - "outport = %s; " - "flags.loopback = 1; " - "next;", - is_ipv4 ? REG_SRC_IPV4 : REG_SRC_IPV6, - lrp_addr_s, - op->lrp_networks.ea_s, - op->json_key); struct ds actions = DS_EMPTY_INITIALIZER; - ds_put_format(&actions, "ip.ttl--; %s", ds_cstr(&common_actions)); + if (is_discard_route) { + ds_put_format(&actions, "drop;"); + } else { + ds_put_format(&common_actions, REG_ECMP_GROUP_ID" = 0; %s = ", + is_ipv4 ? REG_NEXT_HOP_IPV4 : REG_NEXT_HOP_IPV6); + if (gateway) { + ds_put_cstr(&common_actions, gateway); + } else { + ds_put_format(&common_actions, "ip%s.dst", is_ipv4 ? "4" : "6"); + } + ds_put_format(&common_actions, "; " + "%s = %s; " + "eth.src = %s; " + "outport = %s; " + "flags.loopback = 1; " + "next;", + is_ipv4 ? REG_SRC_IPV4 : REG_SRC_IPV6, + lrp_addr_s, + op->lrp_networks.ea_s, + op->json_key); + ds_put_format(&actions, "ip.ttl--; %s", ds_cstr(&common_actions)); + } - ovn_lflow_add_with_hint(lflows, op->od, S_ROUTER_IN_IP_ROUTING, priority, + ovn_lflow_add_with_hint(lflows, od, S_ROUTER_IN_IP_ROUTING, priority, ds_cstr(&match), ds_cstr(&actions), stage_hint); - if (op->has_bfd) { + if (op && op->has_bfd) { ds_put_format(&match, " && udp.dst == 3784"); ovn_lflow_add_with_hint(lflows, op->od, S_ROUTER_IN_IP_ROUTING, priority + 1, ds_cstr(&match), @@ -8311,16 +8323,18 @@ build_static_route_flow(struct hmap *lflows, struct ovn_datapath *od, const struct nbrec_logical_router_static_route *route = route_->route; /* Find the outgoing port. */ - if (!find_static_route_outport(od, ports, route, - IN6_IS_ADDR_V4MAPPED(&route_->prefix), - &lrp_addr_s, &out_port)) { - return; + if (!route_->is_discard_route) { + if (!find_static_route_outport(od, ports, route, + IN6_IS_ADDR_V4MAPPED(&route_->prefix), + &lrp_addr_s, &out_port)) { + return; + } } char *prefix_s = build_route_prefix_s(&route_->prefix, route_->plen); - add_route(lflows, out_port, lrp_addr_s, prefix_s, route_->plen, - route->nexthop, route_->is_src_route, - &route->header_); + add_route(lflows, route_->is_discard_route ? od : out_port->od, out_port, + lrp_addr_s, prefix_s, route_->plen, route->nexthop, + route_->is_src_route, &route->header_, route_->is_discard_route); free(prefix_s); } @@ -9386,17 +9400,17 @@ build_ip_routing_flows_for_lrouter_port( if (op->nbrp) { for (int i = 0; i < op->lrp_networks.n_ipv4_addrs; i++) { - add_route(lflows, op, op->lrp_networks.ipv4_addrs[i].addr_s, + add_route(lflows, op->od, op, op->lrp_networks.ipv4_addrs[i].addr_s, op->lrp_networks.ipv4_addrs[i].network_s, op->lrp_networks.ipv4_addrs[i].plen, NULL, false, - &op->nbrp->header_); + &op->nbrp->header_, false); } for (int i = 0; i < op->lrp_networks.n_ipv6_addrs; i++) { - add_route(lflows, op, op->lrp_networks.ipv6_addrs[i].addr_s, + add_route(lflows, op->od, op, op->lrp_networks.ipv6_addrs[i].addr_s, op->lrp_networks.ipv6_addrs[i].network_s, op->lrp_networks.ipv6_addrs[i].plen, NULL, false, - &op->nbrp->header_); + &op->nbrp->header_, false); } } } diff --git a/ovn-nb.xml b/ovn-nb.xml index a94918bb6..85efd70f2 100644 --- a/ovn-nb.xml +++ b/ovn-nb.xml @@ -2636,7 +2636,9 @@ <column name="nexthop"> <p> Nexthop IP address for this route. Nexthop IP address should be the IP - address of a connected router port or the IP address of a logical port. + address of a connected router port or the IP address of a logical port + or can be set to "discard" for dropping packets which match the given + route. </p> </column> diff --git a/tests/ovn-nbctl.at b/tests/ovn-nbctl.at index 6d91aa4c5..f4b2a88c2 100644 --- a/tests/ovn-nbctl.at +++ b/tests/ovn-nbctl.at @@ -1467,18 +1467,26 @@ AT_CHECK([ovn-nbctl lr-route-add lr0 10.0.0.111/24 11.0.0.1/24], [1], [], AT_CHECK([ovn-nbctl lr-route-add lr0 2001:0db8:1::/64 2001:0db8:0:f103::1/64], [1], [], [ovn-nbctl: bad IPv6 nexthop argument: 2001:0db8:0:f103::1/64 ]) +AT_CHECK([ovn-nbctl lr-route-add lr0 20.0.0.0/24 discard lp0], [1], [], + [ovn-nbctl: outport is not valid for discard routes. +]) AT_CHECK([ovn-nbctl --may-exist lr-route-add lr0 10.0.0.111/24 11.0.0.1]) AT_CHECK([ovn-nbctl --policy=src-ip lr-route-add lr0 9.16.1.0/24 11.0.0.1]) dnl Add a route with existed prefix but different policy (src-ip) AT_CHECK([ovn-nbctl --policy=src-ip lr-route-add lr0 10.0.0.0/24 11.0.0.2]) +AT_CHECK([ovn-nbctl lr-route-add lr0 20.0.0.0/24 discard]) +AT_CHECK([ovn-nbctl --policy=src-ip lr-route-add lr0 20.0.0.0/24 discard]) + AT_CHECK([ovn-nbctl lr-route-list lr0], [0], [dnl IPv4 Routes 10.0.0.0/24 11.0.0.1 dst-ip 10.0.1.0/24 11.0.1.1 dst-ip lp0 + 20.0.0.0/24 discard dst-ip 9.16.1.0/24 11.0.0.1 src-ip 10.0.0.0/24 11.0.0.2 src-ip + 20.0.0.0/24 discard src-ip 0.0.0.0/0 192.168.0.1 dst-ip ]) @@ -1487,11 +1495,16 @@ AT_CHECK([ovn-nbctl lr-route-list lr0], [0], [dnl IPv4 Routes 10.0.0.0/24 11.0.0.1 dst-ip lp1 10.0.1.0/24 11.0.1.1 dst-ip lp0 + 20.0.0.0/24 discard dst-ip 9.16.1.0/24 11.0.0.1 src-ip 10.0.0.0/24 11.0.0.2 src-ip + 20.0.0.0/24 discard src-ip 0.0.0.0/0 192.168.0.1 dst-ip ]) +AT_CHECK([ovn-nbctl --policy=src-ip lr-route-del lr0 20.0.0.0/24]) +AT_CHECK([ovn-nbctl lr-route-del lr0 20.0.0.0/24 discard]) + dnl Delete non-existent prefix AT_CHECK([ovn-nbctl lr-route-del lr0 10.0.2.1/24], [1], [], [ovn-nbctl: no matching route: policy 'any', prefix '10.0.2.0/24', nexthop 'any', output_port 'any'. diff --git a/tests/ovn.at b/tests/ovn.at index 55ea6d170..cdbf035fb 100644 --- a/tests/ovn.at +++ b/tests/ovn.at @@ -24049,3 +24049,96 @@ wait_column "true" nb:Logical_Switch_Port up name=lsp1 OVN_CLEANUP([hv1]) AT_CLEANUP + +AT_SETUP([ovn -- Static route with discard nexthop]) +ovn_start + +# Logical network: +# Logical Router lr1 has Logical Switch sw1 (10.0.0.0/24) connected to it. sw1 has one +# switch port sw1-ls1 (10.0.0.100) + +ovn-nbctl lr-add lr1 + +ovn-nbctl ls-add sw1 + +# Connect sw1 to lr1 +ovn-nbctl lrp-add lr1 lr1-sw1 00:00:01:01:02:03 10.0.0.1/24 +ovn-nbctl lsp-add sw1 sw1-lr1 +ovn-nbctl lsp-set-type sw1-lr1 router +ovn-nbctl lsp-set-addresses sw1-lr1 router +ovn-nbctl lsp-set-options sw1-lr1 router-port=lr1-sw1 + +# Create logical port sw1-lp1 in sw1 +ovn-nbctl lsp-add sw1 sw1-lp1 \ +-- lsp-set-addresses sw1-lp1 "00:00:04:01:02:03 10.0.0.100" + +# Create one hypervisor and create OVS ports corresponding to logical ports. +net_add n1 + +sim_add hv1 +as hv1 +ovs-vsctl add-br br-phys +ovn_attach n1 br-phys 192.168.0.1 + +ovs-vsctl -- add-port br-int hv1-vif1 -- \ + set interface hv1-vif1 external-ids:iface-id=sw1-lp1 \ + options:tx_pcap=hv1/vif1-tx.pcap \ + options:rxq_pcap=hv1/vif1-rx.pcap \ + ofport-request=1 + +# Install static routes to drop traffic +ovn-nbctl lr-route-add lr1 20.0.0.0/24 discard + +# Allow some time for ovn-controller to catch up. +ovn-nbctl --wait=hv sync + +# Check logical flows for drop rule +AT_CHECK([ovn-sbctl dump-flows | grep lr_in_ip_routing | grep "20.0.0.0/24" | \ + grep drop | wc -l], [0], [dnl +1 +]) + +# Send packet. +packet="inport==\"sw1-lp1\" && eth.src==00:00:04:01:02:03 && + eth.dst==00:00:01:01:02:03 && ip4 && ip.ttl==64 && + ip4.src==10.0.0.100 && ip4.dst==20.0.0.200 && + udp && udp.src==53 && udp.dst==4369" + +as hv1 ovs-appctl -t ovn-controller inject-pkt "$packet" + +# Check if packet hit the drop rule +AT_CHECK([ovs-ofctl dump-flows br-int | grep "nw_dst=20.0.0.0/24" | \ + grep "actions=drop" | grep "n_packets=1" | wc -l], [0], [dnl +1 +]) + +# Remove destination match and add discard route with source match +ovn-nbctl lr-route-del lr1 20.0.0.0/24 +ovn-nbctl --policy="src-ip" lr-route-add lr1 10.0.0.0/24 discard + +# Allow some time for ovn-controller to catch up. +ovn-nbctl --wait=hv sync + +# Check logical flows for drop rule +AT_CHECK([ovn-sbctl dump-flows | grep lr_in_ip_routing | grep "10.0.0.0/24" | \ + grep drop | wc -l], [0], [dnl +1 +]) + +# Send packet. +packet="inport==\"sw1-lp1\" && eth.src==00:00:04:01:02:03 && + eth.dst==00:00:01:01:02:03 && ip4 && ip.ttl==64 && + ip4.src==10.0.0.100 && ip4.dst==20.0.0.200 && + udp && udp.src==53 && udp.dst==4369" + +as hv1 ovs-appctl -t ovn-controller inject-pkt "$packet" + +# Check if packet hit the drop rule +AT_CHECK([ovs-ofctl dump-flows br-int "nw_src=10.0.0.0/24" | \ + grep "actions=drop" | grep "n_packets=1" | wc -l], [0], [dnl +1 +]) + +OVN_CLEANUP([hv1]) + +AT_CLEANUP diff --git a/utilities/ovn-nbctl.c b/utilities/ovn-nbctl.c index 2c77f4ba7..cab645d83 100644 --- a/utilities/ovn-nbctl.c +++ b/utilities/ovn-nbctl.c @@ -3972,6 +3972,7 @@ nbctl_lr_route_add(struct ctl_context *ctx) const char *policy = shash_find_data(&ctx->options, "--policy"); bool is_src_route = false; + bool is_discard_route = !strcmp(ctx->argv[3], "discard"); if (policy) { if (!strcmp(policy, "src-ip")) { is_src_route = true; @@ -3992,13 +3993,17 @@ nbctl_lr_route_add(struct ctl_context *ctx) return; } - next_hop = v6_prefix - ? normalize_ipv6_addr_str(ctx->argv[3]) - : normalize_ipv4_addr_str(ctx->argv[3]); - if (!next_hop) { - ctl_error(ctx, "bad %s nexthop argument: %s", - v6_prefix ? "IPv6" : "IPv4", ctx->argv[3]); - goto cleanup; + if (is_discard_route) { + next_hop = xasprintf("discard"); + } else { + next_hop = v6_prefix + ? normalize_ipv6_addr_str(ctx->argv[3]) + : normalize_ipv4_addr_str(ctx->argv[3]); + if (!next_hop) { + ctl_error(ctx, "bad %s nexthop argument: %s", + v6_prefix ? "IPv6" : "IPv4", ctx->argv[3]); + goto cleanup; + } } struct shash_node *bfd = shash_find(&ctx->options, "--bfd"); @@ -4047,6 +4052,10 @@ nbctl_lr_route_add(struct ctl_context *ctx) nbrec_logical_router_static_route_set_ip_prefix(route, prefix); nbrec_logical_router_static_route_set_nexthop(route, next_hop); if (ctx->argc == 5) { + if (is_discard_route) { + ctl_error(ctx, "outport is not valid for discard routes."); + goto cleanup; + } nbrec_logical_router_static_route_set_output_port( route, ctx->argv[4]); } @@ -4076,6 +4085,10 @@ nbctl_lr_route_add(struct ctl_context *ctx) nbrec_logical_router_static_route_set_ip_prefix(route, prefix); nbrec_logical_router_static_route_set_nexthop(route, next_hop); if (ctx->argc == 5) { + if (is_discard_route) { + ctl_error(ctx, "outport is not valid for discard routes."); + goto cleanup; + } nbrec_logical_router_static_route_set_output_port(route, ctx->argv[4]); } if (policy) { @@ -4146,10 +4159,14 @@ nbctl_lr_route_del(struct ctl_context *ctx) char *nexthop = NULL; if (ctx->argc >= 4) { - nexthop = normalize_prefix_str(ctx->argv[3]); - if (!nexthop) { - ctl_error(ctx, "bad nexthop argument: %s", ctx->argv[3]); - return; + if (!strcmp(ctx->argv[3], "discard")) { + nexthop = xasprintf("discard"); + } else { + nexthop = normalize_prefix_str(ctx->argv[3]); + if (!nexthop) { + ctl_error(ctx, "bad nexthop argument: %s", ctx->argv[3]); + return; + } } } @@ -4189,9 +4206,12 @@ nbctl_lr_route_del(struct ctl_context *ctx) } /* Compare nexthop, if specified. */ + bool is_discard_route = !strcmp(lr->static_routes[i]->nexthop, + "discard"); if (nexthop) { - char *rt_nexthop = - normalize_prefix_str(lr->static_routes[i]->nexthop); + char *rt_nexthop = is_discard_route + ? xasprintf("discard") + : normalize_prefix_str(lr->static_routes[i]->nexthop); if (!rt_nexthop) { /* Ignore existing nexthop we couldn't parse. */ continue; @@ -5579,7 +5599,9 @@ print_route(const struct nbrec_logical_router_static_route *route, { char *prefix = normalize_prefix_str(route->ip_prefix); - char *next_hop = normalize_prefix_str(route->nexthop); + char *next_hop = !strcmp(route->nexthop, "discard") + ? xasprintf("discard") + : normalize_prefix_str(route->nexthop); ds_put_format(s, "%25s %25s", prefix, next_hop); free(prefix); free(next_hop); -- 2.22.3 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
