/* * l2_efp_filter.c : layer 2 egress EFP Filter processing * * Copyright (c) 2013 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. */ #include #include #include #include #include #include #include #include #include #include /** * @file * @brief EFP-filter - Ethernet Flow Point Filter. * * It is possible to transmit a packet out a subinterface with VLAN tags * that are not compatible with that subinterface. In other words, if that * packet arrived on the output port, it would not be classified as coming * from the output subinterface. This can happen in various ways: through * misconfiguration, by putting subinterfaces with different VLAN encaps in * the same bridge-domain, etc. The EFP Filter Check detects such packets * and drops them. It consists of two checks, one that verifies the packet * prior to output VLAN tag rewrite and one that verifies the packet after * VLAN tag rewrite. * */ typedef struct { /* Next nodes for L2 output features */ u32 l2_out_feat_next[32]; /* convenience variables */ vlib_main_t *vlib_main; vnet_main_t *vnet_main; } l2_efp_filter_main_t; typedef struct { /* per-pkt trace data */ u8 src[6]; u8 dst[6]; u8 raw[12]; /* raw data (vlans) */ u32 sw_if_index; } l2_efp_filter_trace_t; /* packet trace format function */ static u8 * format_l2_efp_filter_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 *); l2_efp_filter_trace_t *t = va_arg (*args, l2_efp_filter_trace_t *); s = format (s, "l2-output-vtr: sw_if_index %d dst %U src %U data " "%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x", t->sw_if_index, format_ethernet_address, t->dst, format_ethernet_address, t->src, t->raw[0], t->raw[1], t->raw[2], t->raw[3], t->raw[4], t->raw[5], t->raw[6], t->raw[7], t->raw[8], t->raw[9], t->raw[10], t->raw[11]); return s; } extern l2_efp_filter_main_t l2_efp_filter_main; #ifndef CLIB_MARCH_VARIANT l2_efp_filter_main_t l2_efp_filter_main; #endif /* CLIB_MARCH_VARIANT */ #define foreach_l2_efp_filter_error \ _(L2_EFP_FILTER, "L2 EFP filter packets") \ _(DROP, "L2 EFP filter post-rewrite drops") typedef enum { #define _(sym,str) L2_EFP_FILTER_ERROR_##sym, foreach_l2_efp_filter_error #undef _ L2_EFP_FILTER_N_ERROR, } l2_efp_filter_error_t; static char *l2_efp_filter_error_strings[] = { #define _(sym,string) string, foreach_l2_efp_filter_error #undef _ }; typedef enum { L2_EFP_FILTER_NEXT_DROP, L2_EFP_FILTER_N_NEXT, } l2_efp_filter_next_t; /** * Extract fields from the packet that will be used in interface * classification. */ static_always_inline void extract_keys (vnet_main_t * vnet_main, u32 sw_if_index0, vlib_buffer_t * b0, u32 * port_sw_if_index0, u16 * first_ethertype0, u16 * outer_id0, u16 * inner_id0, u32 * match_flags0) { ethernet_header_t *e0; ethernet_vlan_header_t *h0; u32 tag_len; u32 tag_num; *port_sw_if_index0 = vnet_get_sup_sw_interface (vnet_main, sw_if_index0)->sw_if_index; e0 = vlib_buffer_get_current (b0); h0 = (ethernet_vlan_header_t *) (e0 + 1); *first_ethertype0 = clib_net_to_host_u16 (e0->type); *outer_id0 = clib_net_to_host_u16 (h0[0].priority_cfi_and_id); *inner_id0 = clib_net_to_host_u16 (h0[1].priority_cfi_and_id); tag_len = vnet_buffer (b0)->l2.l2_len - sizeof (ethernet_header_t); tag_num = tag_len / sizeof (ethernet_vlan_header_t); *match_flags0 = eth_create_valid_subint_match_flags (tag_num); } /* * EFP filtering is a basic switch feature which prevents an interface from * transmitting a packet that doesn't match the interface's ingress match * criteria. The check has two parts, one performed before egress vlan tag * rewrite and one after. * * The pre-rewrite check insures the packet matches what an ingress packet looks * like after going through the interface's ingress tag rewrite operation. Only * pushed tags are compared. So: * - if the ingress vlan tag rewrite pushes no tags (or is not enabled), * any packet passes the filter * - if the ingress vlan tag rewrite pushes one tag, * the packet must have at least one tag, and the outer tag must match the pushed tag * - if the ingress vlan tag rewrite pushes two tags, * the packet must have at least two tags, and the outer two tags must match the pushed tags * * The pre-rewrite check is performed in the l2-output node. * * The post-rewrite check insures the packet matches what an ingress packet looks * like before going through the interface's ingress tag rewrite operation. It verifies * that such a packet arriving on the wire at this port would be classified as arriving * an input interface equal to the packet's output interface. This can be done by running * the output packet's vlan tags and output port through the interface classification, * and checking if the resulting interface matches the output interface. * * The post-rewrite check is performed here. */ VLIB_NODE_FN (l2_efp_filter_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { u32 n_left_from, *from, *to_next; l2_efp_filter_next_t next_index; l2_efp_filter_main_t *msm = &l2_efp_filter_main; vlib_node_t *n = vlib_get_node (vm, l2_efp_filter_node.index); u32 node_counter_base_index = n->error_heap_index; vlib_error_main_t *em = &vm->error_main; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; /* number of packets to process */ next_index = node->cached_next_index; while (n_left_from > 0) { u32 n_left_to_next; /* get space to enqueue frame to graph node "next_index" */ vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); while (n_left_from >= 6 && n_left_to_next >= 2) { u32 bi0, bi1; vlib_buffer_t *b0, *b1; u32 next0, next1; u32 sw_if_index0, sw_if_index1; u16 first_ethertype0, first_ethertype1; u16 outer_id0, inner_id0, outer_id1, inner_id1; u32 match_flags0, match_flags1; u32 port_sw_if_index0, subint_sw_if_index0, port_sw_if_index1, subint_sw_if_index1; vnet_hw_interface_t *hi0, *hi1; main_intf_t *main_intf0, *main_intf1; vlan_intf_t *vlan_intf0, *vlan_intf1; qinq_intf_t *qinq_intf0, *qinq_intf1; u32 is_l20, is_l21; __attribute__ ((unused)) u32 matched0, matched1; u8 error0, error1; /* Prefetch next iteration. */ { vlib_buffer_t *p2, *p3, *p4, *p5; __attribute__ ((unused)) u32 sw_if_index2, sw_if_index3; p2 = vlib_get_buffer (vm, from[2]); p3 = vlib_get_buffer (vm, from[3]); p4 = vlib_get_buffer (vm, from[4]); p5 = vlib_get_buffer (vm, from[5]); /* Prefetch the buffer header and packet for the N+2 loop iteration */ vlib_prefetch_buffer_header (p4, LOAD); vlib_prefetch_buffer_header (p5, LOAD); CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE); CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE); /* * Prefetch the input config for the N+1 loop iteration * This depends on the buffer header above */ sw_if_index2 = vnet_buffer (p2)->sw_if_index[VLIB_TX]; sw_if_index3 = vnet_buffer (p3)->sw_if_index[VLIB_TX]; /* * $$$ TODO * CLIB_PREFETCH (vec_elt_at_index(l2output_main.configs, sw_if_index2), CLIB_CACHE_LINE_BYTES, LOAD); * CLIB_PREFETCH (vec_elt_at_index(l2output_main.configs, sw_if_index3), CLIB_CACHE_LINE_BYTES, LOAD); */ } /* speculatively enqueue b0 and b1 to the current next frame */ /* bi is "buffer index", b is pointer to the buffer */ to_next[0] = bi0 = from[0]; to_next[1] = bi1 = from[1]; from += 2; to_next += 2; n_left_from -= 2; n_left_to_next -= 2; b0 = vlib_get_buffer (vm, bi0); b1 = vlib_get_buffer (vm, bi1); /* TX interface handles */ sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX]; sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_TX]; /* process 2 packets */ em->counters[node_counter_base_index + L2_EFP_FILTER_ERROR_L2_EFP_FILTER] += 2; /* Determine next node */ next0 = vnet_l2_feature_next (b0, msm->l2_out_feat_next, L2OUTPUT_FEAT_EFP_FILTER); next1 = vnet_l2_feature_next (b1, msm->l2_out_feat_next, L2OUTPUT_FEAT_EFP_FILTER); /* perform the efp filter check on two packets */ extract_keys (msm->vnet_main, sw_if_index0, b0, &port_sw_if_index0, &first_ethertype0, &outer_id0, &inner_id0, &match_flags0); extract_keys (msm->vnet_main, sw_if_index1, b1, &port_sw_if_index1, &first_ethertype1, &outer_id1, &inner_id1, &match_flags1); eth_vlan_table_lookups (ðernet_main, msm->vnet_main, port_sw_if_index0, first_ethertype0, outer_id0, inner_id0, &hi0, &main_intf0, &vlan_intf0, &qinq_intf0); eth_vlan_table_lookups (ðernet_main, msm->vnet_main, port_sw_if_index1, first_ethertype1, outer_id1, inner_id1, &hi1, &main_intf1, &vlan_intf1, &qinq_intf1); matched0 = eth_identify_subint (hi0, match_flags0, main_intf0, vlan_intf0, qinq_intf0, &subint_sw_if_index0, &error0, &is_l20); matched1 = eth_identify_subint (hi1, match_flags1, main_intf1, vlan_intf1, qinq_intf1, &subint_sw_if_index1, &error1, &is_l21); if (PREDICT_FALSE (sw_if_index0 != subint_sw_if_index0)) { /* Drop packet */ next0 = L2_EFP_FILTER_NEXT_DROP; b0->error = node->errors[L2_EFP_FILTER_ERROR_DROP]; } if (PREDICT_FALSE (sw_if_index1 != subint_sw_if_index1)) { /* Drop packet */ next1 = L2_EFP_FILTER_NEXT_DROP; b1->error = node->errors[L2_EFP_FILTER_ERROR_DROP]; } if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE))) { if (b0->flags & VLIB_BUFFER_IS_TRACED) { ethernet_header_t *h0 = vlib_buffer_get_current (b0); l2_efp_filter_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); t->sw_if_index = sw_if_index0; clib_memcpy_fast (t->src, h0->src_address, 6); clib_memcpy_fast (t->dst, h0->dst_address, 6); clib_memcpy_fast (t->raw, &h0->type, sizeof (t->raw)); } if (b1->flags & VLIB_BUFFER_IS_TRACED) { ethernet_header_t *h1 = vlib_buffer_get_current (b1); l2_efp_filter_trace_t *t = vlib_add_trace (vm, node, b1, sizeof (*t)); t->sw_if_index = sw_if_index1; clib_memcpy_fast (t->src, h1->src_address, 6); clib_memcpy_fast (t->dst, h1->dst_address, 6); clib_memcpy_fast (t->raw, &h1->type, sizeof (t->raw)); } } /* verify speculative enqueues, maybe switch current next frame */ /* if next0==next1==next_index then nothing special needs to be done */ vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next, n_left_to_next, bi0, bi1, next0, next1); } while (n_left_from > 0 && n_left_to_next > 0) { u32 bi0; vlib_buffer_t *b0; u32 next0; u32 sw_if_index0; u16 first_ethertype0; u16 outer_id0, inner_id0; u32 match_flags0; u32 port_sw_if_index0, subint_sw_if_index0; vnet_hw_interface_t *hi0; main_intf_t *main_intf0; vlan_intf_t *vlan_intf0; qinq_intf_t *qinq_intf0; u32 is_l20; __attribute__ ((unused)) u32 matched0; u8 error0; /* speculatively enqueue b0 to the current next frame */ bi0 = from[0]; to_next[0] = bi0; from += 1; to_next += 1; n_left_from -= 1; n_left_to_next -= 1; b0 = vlib_get_buffer (vm, bi0); sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX]; /* process 1 packet */ em->counters[node_counter_base_index + L2_EFP_FILTER_ERROR_L2_EFP_FILTER] += 1; /* Determine next node */ next0 = vnet_l2_feature_next (b0, msm->l2_out_feat_next, L2OUTPUT_FEAT_EFP_FILTER); /* perform the efp filter check on one packet */ extract_keys (msm->vnet_main, sw_if_index0, b0, &port_sw_if_index0, &first_ethertype0, &outer_id0, &inner_id0, &match_flags0); eth_vlan_table_lookups (ðernet_main, msm->vnet_main, port_sw_if_index0, first_ethertype0, outer_id0, inner_id0, &hi0, &main_intf0, &vlan_intf0, &qinq_intf0); matched0 = eth_identify_subint (hi0, match_flags0, main_intf0, vlan_intf0, qinq_intf0, &subint_sw_if_index0, &error0, &is_l20); if (PREDICT_FALSE (sw_if_index0 != subint_sw_if_index0)) { /* Drop packet */ next0 = L2_EFP_FILTER_NEXT_DROP; b0->error = node->errors[L2_EFP_FILTER_ERROR_DROP]; } if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) && (b0->flags & VLIB_BUFFER_IS_TRACED))) { ethernet_header_t *h0 = vlib_buffer_get_current (b0); l2_efp_filter_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); t->sw_if_index = sw_if_index0; clib_memcpy_fast (t->src, h0->src_address, 6); clib_memcpy_fast (t->dst, h0->dst_address, 6); clib_memcpy_fast (t->raw, &h0->type, sizeof (t->raw)); } /* verify speculative enqueue, maybe switch current next frame */ 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; } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (l2_efp_filter_node) = { .name = "l2-efp-filter", .vector_size = sizeof (u32), .format_trace = format_l2_efp_filter_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = ARRAY_LEN(l2_efp_filter_error_strings), .error_strings = l2_efp_filter_error_strings, .n_next_nodes = L2_EFP_FILTER_N_NEXT, /* edit / add dispositions here */ .next_nodes = { [L2_EFP_FILTER_NEXT_DROP] = "error-drop", }, }; /* *INDENT-ON* */ #ifndef CLIB_MARCH_VARIANT clib_error_t * l2_efp_filter_init (vlib_main_t * vm) { l2_efp_filter_main_t *mp = &l2_efp_filter_main; mp->vlib_main = vm; mp->vnet_main = vnet_get_main (); /* Initialize the feature next-node indexes */ feat_bitmap_init_next_nodes (vm, l2_efp_filter_node.index, L2OUTPUT_N_FEAT, l2output_get_feat_names (), mp->l2_out_feat_next); return 0; } VLIB_INIT_FUNCTION (l2_efp_filter_init); /** Enable/disable the EFP Filter check on the subinterface. */ void l2_efp_filter_configure (vnet_main_t * vnet_main, u32 sw_if_index, u8 enable) { /* set the interface flag */ l2output_intf_bitmap_enable (sw_if_index, L2OUTPUT_FEAT_EFP_FILTER, enable); } /** * Set subinterface egress efp filter enable/disable. * The CLI format is: * set interface l2 efp-filter [disable]] */ static clib_error_t * int_l2_efp_filter (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd) { vnet_main_t *vnm = vnet_get_main (); clib_error_t *error = 0; u32 sw_if_index; u32 enable; if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index)) { error = clib_error_return (0, "unknown interface `%U'", format_unformat_error, input); goto done; } enable = 1; if (unformat (input, "disable")) { enable = 0; } /* enable/disable the feature */ l2_efp_filter_configure (vnm, sw_if_index, enable); done: return error; } /*? * EFP filtering is a basic switch feature which prevents an interface from * transmitting a packet that doesn't match the interface's ingress match * criteria. The check has two parts, one performed before egress vlan tag * rewrite and one after. This command enables or disables the EFP filtering * for a given sub-interface. * * @cliexpar * Example of how to enable a Layer 2 efp-filter on a sub-interface: * @cliexcmd{set interface l2 efp-filter GigabitEthernet0/8/0.200} * Example of how to disable a Layer 2 efp-filter on a sub-interface: * @cliexcmd{set interface l2 efp-filter GigabitEthernet0/8/0.200 disable} ?*/ /* *INDENT-OFF* */ VLIB_CLI_COMMAND (int_l2_efp_filter_cli, static) = { .path = "set interface l2 efp-filter", .short_help = "set interface l2 efp-filter [disable]", .function = int_l2_efp_filter, }; /* *INDENT-ON* */ #endif /* CLIB_MARCH_VARIANT */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */