/* * Copyright (c) 2016 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * @brief * The data-path object representing dropping the packet */ #include <vnet/dpo/ip_null_dpo.h> #include <vnet/ip/ip.h> /** * @brief A representation of the IP_NULL DPO */ typedef struct ip_null_dpo_t_ { /** * @brief The action to take on a packet */ ip_null_dpo_action_t ind_action; /** * @brief The next VLIB node */ u32 ind_next_index; /** * rate limits */ } ip_null_dpo_t; /** * @brief the IP_NULL dpos are shared by all routes, hence they are global. * As the neame implies this is only for IP, hence 2. */ static ip_null_dpo_t ip_null_dpos[2 * IP_NULL_DPO_ACTION_NUM] = { [0] = { /* proto ip4, no action */ .ind_action = IP_NULL_ACTION_NONE, }, [1] = { /* proto ip4, action send unreach */ .ind_action = IP_NULL_ACTION_SEND_ICMP_UNREACH, }, [2] = { /* proto ip4, action send unreach */ .ind_action = IP_NULL_ACTION_SEND_ICMP_PROHIBIT, }, [3] = { /* proto ip6, no action */ .ind_action = IP_NULL_ACTION_NONE, }, [4] = { /* proto ip6, action send unreach */ .ind_action = IP_NULL_ACTION_SEND_ICMP_UNREACH, }, [5] = { /* proto ip6, action send unreach */ .ind_action = IP_NULL_ACTION_SEND_ICMP_PROHIBIT, }, }; /** * @brief Action strings */ const char *ip_null_action_strings[] = IP_NULL_ACTIONS; void ip_null_dpo_add_and_lock (dpo_proto_t proto, ip_null_dpo_action_t action, dpo_id_t *dpo) { int i; ASSERT((proto == DPO_PROTO_IP4) || (proto == DPO_PROTO_IP6)); ASSERT(action < IP_NULL_DPO_ACTION_NUM); i = (proto == DPO_PROTO_IP4 ? 0 : 1); dpo_set(dpo, DPO_IP_NULL, proto, (i*IP_NULL_DPO_ACTION_NUM) + action); } always_inline const ip_null_dpo_t* ip_null_dpo_get (index_t indi) { return (&ip_null_dpos[indi]); } static void ip_null_dpo_lock (dpo_id_t *dpo) { /* * not maintaining a lock count on the ip_null, they are const global and * never die. */ } static void ip_null_dpo_unlock (dpo_id_t *dpo) { } static u8* format_ip_null_dpo (u8 *s, va_list *ap) { index_t index = va_arg(*ap, index_t); CLIB_UNUSED(u32 indent) = va_arg(*ap, u32); const ip_null_dpo_t *ind; dpo_proto_t proto; ind = ip_null_dpo_get(index); proto = (index < IP_NULL_DPO_ACTION_NUM ? DPO_PROTO_IP4 : DPO_PROTO_IP6); return (format(s, "%U-null action:%s", format_dpo_proto, proto, ip_null_action_strings[ind->ind_action])); } const static dpo_vft_t ip_null_vft = { .dv_lock = ip_null_dpo_lock, .dv_unlock = ip_null_dpo_unlock, .dv_format = format_ip_null_dpo, }; /** * @brief The per-protocol VLIB graph nodes that are assigned to a ip_null * object. * * this means that these graph nodes are ones from which a ip_null is the * parent object in the DPO-graph. */ const static char* const ip4_null_nodes[] = { "ip4-null", NULL, }; const static char* const ip6_null_nodes[] = { "ip6-null", NULL, }; const static char* const * const ip_null_nodes[DPO_PROTO_NUM] = { [DPO_PROTO_IP4] = ip4_null_nodes, [DPO_PROTO_IP6] = ip6_null_nodes, }; typedef struct ip_null_dpo_trace_t_ { index_t ind_index; } ip_null_dpo_trace_t; /** * @brief Exit nodes from a IP_NULL */ typedef enum ip_null_next_t_ { IP_NULL_NEXT_DROP, IP_NULL_NEXT_ICMP, IP_NULL_NEXT_NUM, } ip_null_next_t; always_inline uword ip_null_dpo_switch (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame, u8 is_ip4) { u32 n_left_from, next_index, *from, *to_next; static f64 time_last_seed_change = -1e100; static u32 hash_seeds[3]; static uword hash_bitmap[256 / BITS (uword)]; f64 time_now; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; time_now = vlib_time_now (vm); if (time_now - time_last_seed_change > 1e-1) { uword i; u32 * r = clib_random_buffer_get_data (&vm->random_buffer, sizeof (hash_seeds)); for (i = 0; i < ARRAY_LEN (hash_seeds); i++) hash_seeds[i] = r[i]; /* Mark all hash keys as been not-seen before. */ for (i = 0; i < ARRAY_LEN (hash_bitmap); i++) hash_bitmap[i] = 0; time_last_seed_change = time_now; } next_index = node->cached_next_index; while (n_left_from > 0) { u32 n_left_to_next; vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); while (n_left_from > 0 && n_left_to_next > 0) { u32 a0, b0, c0, m0, drop0; vlib_buffer_t *p0; u32 bi0, indi0, next0; const ip_null_dpo_t *ind0; uword bm0; bi0 = from[0]; to_next[0] = bi0; from += 1; to_next += 1; n_left_from -= 1; n_left_to_next -= 1; p0 = vlib_get_buffer (vm, bi0); /* lookup dst + src mac */ indi0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX]; ind0 = ip_null_dpo_get(indi0); next0 = IP_NULL_NEXT_DROP; /* * rate limit - don't DoS the sender. */ a0 = hash_seeds[0]; b0 = hash_seeds[1]; c0 = hash_seeds[2]; if (is_ip4) { ip4_header_t *ip0 = vlib_buffer_get_current (p0); a0 ^= ip0->dst_address.data_u32; b0 ^= ip0->src_address.data_u32; hash_v3_finalize32 (a0, b0, c0); } else { ip6_header_t *ip0 = vlib_buffer_get_current (p0); a0 ^= ip0->dst_address.as_u32[0]; b0 ^= ip0->src_address.as_u32[0]; c0 ^= ip0->src_address.as_u32[1]; hash_v3_mix32 (a0, b0, c0); a0 ^= ip0->dst_address.as_u32[1]; b0 ^= ip0->src_address.as_u32[2]; c0 ^= ip0->src_address.as_u32[3]; hash_v3_finalize32 (a0, b0, c0); } c0 &= BITS (hash_bitmap) - 1; c0 = c0 / BITS (uword); m0 = (uword) 1 << (c0 % BITS (uword)); bm0 = hash_bitmap[c0]; drop0 = (bm0 & m0) != 0; /* Mark it as seen. */ hash_bitmap[c0] = bm0 | m0; if (PREDICT_FALSE(!drop0)) { if (is_ip4) { /* * There's a trade-off here. This conditinal statement * versus a graph node per-condition. Given the number * expect number of packets to reach a null route is 0 * we favour the run-time cost over the graph complexity */ if (IP_NULL_ACTION_SEND_ICMP_UNREACH == ind0->ind_action) { next0 = IP_NULL_NEXT_ICMP; icmp4_error_set_vnet_buffer( p0, ICMP4_destination_unreachable, ICMP4_destination_unreachable_destination_unreachable_host, 0); } else if (IP_NULL_ACTION_SEND_ICMP_PROHIBIT == ind0->ind_action) { next0 = IP_NULL_NEXT_ICMP; icmp4_error_set_vnet_buffer( p0, ICMP4_destination_unreachable, ICMP4_destination_unreachable_host_administratively_prohibited, 0); } } else { if (IP_NULL_ACTION_SEND_ICMP_UNREACH == ind0->ind_action) { next0 = IP_NULL_NEXT_ICMP; icmp6_error_set_vnet_buffer( p0, ICMP6_destination_unreachable, ICMP6_destination_unreachable_no_route_to_destination, 0); } else if (IP_NULL_ACTION_SEND_ICMP_PROHIBIT == ind0->ind_action) { next0 = IP_NULL_NEXT_ICMP; icmp6_error_set_vnet_buffer( p0, ICMP6_destination_unreachable, ICMP6_destination_unreachable_destination_administratively_prohibited, 0); } } } if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED)) { ip_null_dpo_trace_t *tr = vlib_add_trace (vm, node, p0, sizeof (*tr)); tr->ind_index = indi0; } vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, bi0, next0); } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } return frame->n_vectors; } static u8 * format_ip_null_dpo_trace (u8 * s, va_list * args) { CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); ip_null_dpo_trace_t *t = va_arg (*args, ip_null_dpo_trace_t *); s = format (s, "%U", format_ip_null_dpo, t->ind_index, 0); return s; } static uword ip4_null_dpo_switch (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return (ip_null_dpo_switch(vm, node, frame, 1)); } /** * @brief */ VLIB_REGISTER_NODE (ip4_null_dpo_node) = { .function = ip4_null_dpo_switch, .name = "ip4-null", .vector_size = sizeof (u32), .format_trace = format_ip_null_dpo_trace, .n_next_nodes = IP_NULL_NEXT_NUM, .next_nodes = { [IP_NULL_NEXT_DROP] = "ip4-drop", [IP_NULL_NEXT_ICMP] = "ip4-icmp-error", }, }; static uword ip6_null_dpo_switch (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return (ip_null_dpo_switch(vm, node, frame, 0)); } /** * @brief */ VLIB_REGISTER_NODE (ip6_null_dpo_node) = { .function = ip6_null_dpo_switch, .name = "ip6-null", .vector_size = sizeof (u32), .format_trace = format_ip_null_dpo_trace, .n_next_nodes = IP_NULL_NEXT_NUM, .next_nodes = { [IP_NULL_NEXT_DROP] = "ip6-drop", [IP_NULL_NEXT_ICMP] = "ip6-icmp-error", }, }; void ip_null_dpo_module_init (void) { dpo_register(DPO_IP_NULL, &ip_null_vft, ip_null_nodes); }