/* * l2_flood.c : layer 2 flooding * * 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 Ethernet Flooding. * * Flooding uses the packet replication infrastructure to send a copy of the * packet to each member interface. Logically the replication infrastructure * expects two graph nodes: a prep node that initiates replication and sends the * packet to the first destination, and a recycle node that is passed the packet * after it has been transmitted. * * To decrease the amount of code, l2 flooding implements both functions in * the same graph node. This node can tell if is it being called as the "prep" * or "recycle" using replication_is_recycled(). */ typedef struct { /* Next nodes for each feature */ u32 feat_next_node_index[32]; /* next node index for the L3 input node of each ethertype */ next_by_ethertype_t l3_next; /* convenience variables */ vlib_main_t *vlib_main; vnet_main_t *vnet_main; /* per-cpu vector of cloned packets */ u32 **clones; l2_flood_member_t ***members; } l2flood_main_t; typedef struct { u8 src[6]; u8 dst[6]; u32 sw_if_index; u16 bd_index; } l2flood_trace_t; /* packet trace format function */ static u8 * format_l2flood_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 *); l2flood_trace_t *t = va_arg (*args, l2flood_trace_t *); s = format (s, "l2-flood: sw_if_index %d dst %U src %U bd_index %d", t->sw_if_index, format_ethernet_address, t->dst, format_ethernet_address, t->src, t->bd_index); return s; } extern l2flood_main_t l2flood_main; #ifndef CLIB_MARCH_VARIANT l2flood_main_t l2flood_main; #endif /* CLIB_MARCH_VARIANT */ #define foreach_l2flood_error \ _(L2FLOOD, "L2 flood packets") \ _(REPL_FAIL, "L2 replication failures") \ _(NO_MEMBERS, "L2 replication complete") \ _(BVI_BAD_MAC, "BVI L3 mac mismatch") \ _(BVI_ETHERTYPE, "BVI packet with unhandled ethertype") typedef enum { #define _(sym,str) L2FLOOD_ERROR_##sym, foreach_l2flood_error #undef _ L2FLOOD_N_ERROR, } l2flood_error_t; static char *l2flood_error_strings[] = { #define _(sym,string) string, foreach_l2flood_error #undef _ }; typedef enum { L2FLOOD_NEXT_L2_OUTPUT, L2FLOOD_NEXT_DROP, L2FLOOD_N_NEXT, } l2flood_next_t; /* * Perform flooding on one packet * * Due to the way BVI processing can modify the packet, the BVI interface * (if present) must be processed last in the replication. The member vector * is arranged so that the BVI interface is always the first element. * Flooding walks the vector in reverse. * * BVI processing causes the packet to go to L3 processing. This strips the * L2 header, which is fine because the replication infrastructure restores * it. However L3 processing can trigger larger changes to the packet. For * example, an ARP request could be turned into an ARP reply, an ICMP request * could be turned into an ICMP reply. If BVI processing is not performed * last, the modified packet would be replicated to the remaining members. */ VLIB_NODE_FN (l2flood_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { u32 n_left_from, *from, *to_next; l2flood_next_t next_index; l2flood_main_t *msm = &l2flood_main; u32 thread_index = vm->thread_index; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; 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) { u16 n_clones, n_cloned, clone0; l2_bridge_domain_t *bd_config; u32 sw_if_index0, bi0, ci0; l2_flood_member_t *member; vlib_buffer_t *b0, *c0; u16 next0; u8 in_shg; i32 mi; /* speculatively enqueue b0 to the current next frame */ bi0 = from[0]; from += 1; n_left_from -= 1; next0 = L2FLOOD_NEXT_L2_OUTPUT; b0 = vlib_get_buffer (vm, bi0); /* Get config for the bridge domain interface */ bd_config = vec_elt_at_index (l2input_main.bd_configs, vnet_buffer (b0)->l2.bd_index); in_shg = vnet_buffer (b0)->l2.shg; sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX]; vec_validate (msm->members[thread_index], vec_len (bd_config->members)); vec_reset_length (msm->members[thread_index]); /* Find first members that passes the reflection and SHG checks */ for (mi = bd_config->flood_count - 1; mi >= 0; mi--) { member = &bd_config->members[mi]; if ((member->sw_if_index != sw_if_index0) && (!in_shg || (member->shg != in_shg))) { vec_add1 (msm->members[thread_index], member); } } n_clones = vec_len (msm->members[thread_index]); if (0 == n_clones) { /* No members to flood to */ to_next[0] = bi0; to_next += 1; n_left_to_next -= 1; b0->error = node->errors[L2FLOOD_ERROR_NO_MEMBERS]; vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, bi0, L2FLOOD_NEXT_DROP); continue; } else if (n_clones > 1) { vec_validate (msm->clones[thread_index], n_clones); /* * the header offset needs to be large enough to incorporate * all the L3 headers that could be touched when doing BVI * processing. So take the current l2 length plus 2 * IPv6 * headers (for tunnel encap) */ n_cloned = vlib_buffer_clone (vm, bi0, msm->clones[thread_index], n_clones, VLIB_BUFFER_CLONE_HEAD_SIZE); vec_set_len (msm->clones[thread_index], n_cloned); if (PREDICT_FALSE (n_cloned != n_clones)) { b0->error = node->errors[L2FLOOD_ERROR_REPL_FAIL]; /* Worst-case, no clones, consume the original buf */ if (n_cloned == 0) { ci0 = bi0; member = msm->members[thread_index][0]; goto use_original_buffer; } } /* * for all but the last clone, these are not BVI bound */ for (clone0 = 0; clone0 < n_cloned - 1; clone0++) { member = msm->members[thread_index][clone0]; ci0 = msm->clones[thread_index][clone0]; c0 = vlib_get_buffer (vm, ci0); to_next[0] = ci0; to_next += 1; n_left_to_next -= 1; if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) && (b0->flags & VLIB_BUFFER_IS_TRACED))) { ethernet_header_t *h0; l2flood_trace_t *t; t = vlib_add_trace (vm, node, c0, sizeof (*t)); h0 = vlib_buffer_get_current (c0); t->sw_if_index = sw_if_index0; t->bd_index = vnet_buffer (c0)->l2.bd_index; clib_memcpy_fast (t->src, h0->src_address, 6); clib_memcpy_fast (t->dst, h0->dst_address, 6); } /* Do normal L2 forwarding */ vnet_buffer (c0)->sw_if_index[VLIB_TX] = member->sw_if_index; vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, ci0, next0); if (PREDICT_FALSE (0 == n_left_to_next)) { vlib_put_next_frame (vm, node, next_index, n_left_to_next); vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); } } member = msm->members[thread_index][clone0]; ci0 = msm->clones[thread_index][clone0]; } else { /* one clone */ ci0 = bi0; member = msm->members[thread_index][0]; } use_original_buffer: /* * the last clone that might go to a BVI */ c0 = vlib_get_buffer (vm, ci0); to_next[0] = ci0; to_next += 1; n_left_to_next -= 1; if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) && (b0->flags & VLIB_BUFFER_IS_TRACED))) { ethernet_header_t *h0; l2flood_trace_t *t; t = vlib_add_trace (vm, node, c0, sizeof (*t)); h0 = vlib_buffer_get_current (c0); t->sw_if_index = sw_if_index0; t->bd_index = vnet_buffer (c0)->l2.bd_index; clib_memcpy_fast (t->src, h0->src_address, 6); clib_memcpy_fast (t->dst, h0->dst_address, 6); } /* Forward packet to the current member */ if (PREDICT_FALSE (member->flags & L2_FLOOD_MEMBER_BVI)) { /* Do BVI processing */ u32 rc; rc = l2_to_bvi (vm, msm->vnet_main, c0, member->sw_if_index, &msm->l3_next, &next0); if (PREDICT_FALSE (rc != TO_BVI_ERR_OK)) { if (rc == TO_BVI_ERR_BAD_MAC) { c0->error = node->errors[L2FLOOD_ERROR_BVI_BAD_MAC]; } else if (rc == TO_BVI_ERR_ETHERTYPE) { c0->error = node->errors[L2FLOOD_ERROR_BVI_ETHERTYPE]; } next0 = L2FLOOD_NEXT_DROP; } } else { /* Do normal L2 forwarding */ vnet_buffer (c0)->sw_if_index[VLIB_TX] = member->sw_if_index; } vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, ci0, next0); if (PREDICT_FALSE (0 == n_left_to_next)) { vlib_put_next_frame (vm, node, next_index, n_left_to_next); vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); } } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } vlib_node_increment_counter (vm, node->node_index, L2FLOOD_ERROR_L2FLOOD, frame->n_vectors); return frame->n_vectors; } VLIB_REGISTER_NODE (l2flood_node) = { .name = "l2-flood", .vector_size = sizeof (u32), .format_trace = format_l2flood_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = ARRAY_LEN(l2flood_error_strings), .error_strings = l2flood_error_strings, .n_next_nodes = L2FLOOD_N_NEXT, /* edit / add dispositions here */ .next_nodes = { [L2FLOOD_NEXT_L2_OUTPUT] = "l2-output", [L2FLOOD_NEXT_DROP] = "error-drop", }, }; #ifndef CLIB_MARCH_VARIANT clib_error_t * l2flood_init (vlib_main_t * vm) { l2flood_main_t *mp = &l2flood_main; mp->vlib_main = vm; mp->vnet_main = vnet_get_main (); vec_validate (mp->clones, vlib_num_workers ()); vec_validate (mp->members, vlib_num_workers ()); /* Initialize the feature next-node indexes */ feat_bitmap_init_next_nodes (vm, l2flood_node.index, L2INPUT_N_FEAT, l2input_get_feat_names (), mp->feat_next_node_index); return NULL; } VLIB_INIT_FUNCTION (l2flood_init); /** Add the L3 input node for this ethertype to the next nodes structure. */ void l2flood_register_input_type (vlib_main_t * vm, ethernet_type_t type, u32 node_index) { l2flood_main_t *mp = &l2flood_main; u32 next_index; next_index = vlib_node_add_next (vm, l2flood_node.index, node_index); next_by_ethertype_register (&mp->l3_next, type, next_index); } #endif /* CLIB_MARCH_VARIANT */ /** * Set subinterface flood enable/disable. * The CLI format is: * set interface l2 flood [disable] */ static clib_error_t * int_flood (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; } /* set the interface flag */ l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_FLOOD, enable); done: return error; } /*? * Layer 2 flooding can be enabled and disabled on each * interface and on each bridge-domain. Use this command to * manage interfaces. It is enabled by default. * * @cliexpar * Example of how to enable flooding: * @cliexcmd{set interface l2 flood GigabitEthernet0/8/0} * Example of how to disable flooding: * @cliexcmd{set interface l2 flood GigabitEthernet0/8/0 disable} ?*/ VLIB_CLI_COMMAND (int_flood_cli, static) = { .path = "set interface l2 flood", .short_help = "set interface l2 flood [disable]", .function = int_flood, }; /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */