--- /dev/null
+/*
+ * 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 <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vlib/cli.h>
+#include <vnet/l2/l2_input.h>
+#include <vnet/l2/feat_bitmap.h>
+#include <vnet/l2/l2_bvi.h>
+#include <vnet/replication.h>
+#include <vnet/l2/l2_fib.h>
+
+#include <vppinfra/error.h>
+#include <vppinfra/hash.h>
+
+
+/**
+ * @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;
+} 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;
+}
+
+l2flood_main_t l2flood_main;
+
+static vlib_node_registration_t l2flood_node;
+
+#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.
+ */
+
+static_always_inline void
+l2flood_process (vlib_main_t * vm,
+ vlib_node_runtime_t * node,
+ l2flood_main_t * msm,
+ u64 * counter_base,
+ vlib_buffer_t * b0,
+ u32 * sw_if_index0,
+ l2fib_entry_key_t * key0,
+ u32 * bucket0, l2fib_entry_result_t * result0, u32 * next0)
+{
+ u16 bd_index0;
+ l2_bridge_domain_t *bd_config;
+ l2_flood_member_t *members;
+ i32 current_member; /* signed */
+ replication_context_t *ctx;
+ u8 in_shg = vnet_buffer (b0)->l2.shg;
+
+ if (!replication_is_recycled (b0))
+ {
+
+ /* Do flood "prep node" processing */
+
+ /* Get config for the bridge domain interface */
+ bd_index0 = vnet_buffer (b0)->l2.bd_index;
+ bd_config = vec_elt_at_index (l2input_main.bd_configs, bd_index0);
+ members = bd_config->members;
+
+ /* Find first member that passes the reflection and SHG checks */
+ current_member = bd_config->flood_count - 1;
+ while ((current_member >= 0) &&
+ ((members[current_member].sw_if_index == *sw_if_index0) ||
+ (in_shg && members[current_member].shg == in_shg)))
+ {
+ current_member--;
+ }
+
+ if (current_member < 0)
+ {
+ /* No members to flood to */
+ *next0 = L2FLOOD_NEXT_DROP;
+ b0->error = node->errors[L2FLOOD_ERROR_NO_MEMBERS];
+ return;
+ }
+
+ if ((current_member > 0) &&
+ ((current_member > 1) ||
+ ((members[0].sw_if_index != *sw_if_index0) &&
+ (!in_shg || members[0].shg != in_shg))))
+ {
+ /* If more than one member then initiate replication */
+ ctx =
+ replication_prep (vm, b0, l2flood_node.index, 1 /* l2_packet */ );
+ ctx->feature_replicas = (uword) members;
+ ctx->feature_counter = current_member;
+ }
+
+ }
+ else
+ {
+ vnet_buffer_opaque_t *vnet_buff_op;
+
+ /* Do flood "recycle node" processing */
+
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_REPL_FAIL))
+ {
+ (void) replication_recycle (vm, b0, 1 /* is_last */ );
+ *next0 = L2FLOOD_NEXT_DROP;
+ b0->error = node->errors[L2FLOOD_ERROR_REPL_FAIL];
+ return;
+ }
+
+ ctx = replication_get_ctx (b0);
+ replication_clear_recycled (b0);
+
+ members = (l2_flood_member_t *) (intptr_t) ctx->feature_replicas;
+ current_member = (i32) ctx->feature_counter - 1;
+
+ /* Need to update input index from saved packet context */
+ vnet_buff_op = (vnet_buffer_opaque_t *) ctx->vnet_buffer;
+ *sw_if_index0 = vnet_buff_op->sw_if_index[VLIB_RX];
+
+ /* Find next member that passes the reflection and SHG check */
+ while ((current_member >= 0) &&
+ ((members[current_member].sw_if_index == *sw_if_index0) ||
+ (in_shg && members[current_member].shg == in_shg)))
+ {
+ current_member--;
+ }
+
+ if (current_member < 0)
+ {
+ /*
+ * No more members to flood to.
+ * Terminate replication and drop packet.
+ */
+
+ replication_recycle (vm, b0, 1 /* is_last */ );
+
+ *next0 = L2FLOOD_NEXT_DROP;
+ /* Ideally we woudn't bump a counter here, just silently complete */
+ b0->error = node->errors[L2FLOOD_ERROR_NO_MEMBERS];
+ return;
+ }
+
+ /* Restore packet and context and continue replication */
+ ctx->feature_counter = current_member;
+ replication_recycle (vm, b0, ((current_member == 0) || /*is_last */
+ ((current_member == 1) &&
+ ((members[0].sw_if_index ==
+ *sw_if_index0) || (in_shg
+ && members[0].shg ==
+ in_shg)))));
+ }
+
+ /* Forward packet to the current member */
+ if (PREDICT_FALSE (members[current_member].flags & L2_FLOOD_MEMBER_BVI))
+ {
+ /* Do BVI processing */
+ u32 rc;
+ rc = l2_to_bvi (vm,
+ msm->vnet_main,
+ b0,
+ members[current_member].sw_if_index,
+ &msm->l3_next, next0);
+
+ if (PREDICT_FALSE (rc))
+ {
+ if (rc == TO_BVI_ERR_BAD_MAC)
+ {
+ b0->error = node->errors[L2FLOOD_ERROR_BVI_BAD_MAC];
+ *next0 = L2FLOOD_NEXT_DROP;
+ }
+ else if (rc == TO_BVI_ERR_ETHERTYPE)
+ {
+ b0->error = node->errors[L2FLOOD_ERROR_BVI_ETHERTYPE];
+ *next0 = L2FLOOD_NEXT_DROP;
+ }
+ }
+ }
+ else
+ {
+ /* Do normal L2 forwarding */
+ vnet_buffer (b0)->sw_if_index[VLIB_TX] =
+ members[current_member].sw_if_index;
+ *next0 = L2FLOOD_NEXT_L2_OUTPUT;
+
+ }
+
+}
+
+
+static uword
+l2flood_node_fn (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;
+ vlib_node_t *n = vlib_get_node (vm, l2flood_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;
+ l2fib_entry_key_t key0, key1;
+ l2fib_entry_result_t result0, result1;
+ u32 bucket0, bucket1;
+
+ /* Prefetch next iteration. */
+ {
+ vlib_buffer_t *p2, *p3, *p4, *p5;
+
+ 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 for the N+2 loop iteration */
+ vlib_prefetch_buffer_header (p4, LOAD);
+ vlib_prefetch_buffer_header (p5, LOAD);
+
+ /* Prefetch the replication context for the N+1 loop iteration */
+ /* This depends on the buffer header above */
+ replication_prefetch_ctx (p2);
+ replication_prefetch_ctx (p3);
+
+ /* Prefetch the packet for the N+1 loop iteration */
+ CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
+ CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
+ }
+
+ /* 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);
+
+ /* RX interface handles */
+ sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+ sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
+
+ /* process 2 pkts */
+ em->counters[node_counter_base_index + L2FLOOD_ERROR_L2FLOOD] += 2;
+
+ l2flood_process (vm, node, msm,
+ &em->counters[node_counter_base_index], b0,
+ &sw_if_index0, &key0, &bucket0, &result0, &next0);
+
+ l2flood_process (vm, node, msm,
+ &em->counters[node_counter_base_index], b1,
+ &sw_if_index1, &key1, &bucket1, &result1, &next1);
+
+ if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
+ {
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ l2flood_trace_t *t =
+ vlib_add_trace (vm, node, b0, sizeof (*t));
+ ethernet_header_t *h0 = vlib_buffer_get_current (b0);
+ t->sw_if_index = sw_if_index0;
+ t->bd_index = vnet_buffer (b0)->l2.bd_index;
+ clib_memcpy (t->src, h0->src_address, 6);
+ clib_memcpy (t->dst, h0->dst_address, 6);
+ }
+ if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ l2flood_trace_t *t =
+ vlib_add_trace (vm, node, b1, sizeof (*t));
+ ethernet_header_t *h1 = vlib_buffer_get_current (b1);
+ t->sw_if_index = sw_if_index1;
+ t->bd_index = vnet_buffer (b1)->l2.bd_index;
+ clib_memcpy (t->src, h1->src_address, 6);
+ clib_memcpy (t->dst, h1->dst_address, 6);
+ }
+ }
+
+ /* 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;
+ l2fib_entry_key_t key0;
+ l2fib_entry_result_t result0;
+ u32 bucket0;
+
+ /* 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_RX];
+
+ /* process 1 pkt */
+ em->counters[node_counter_base_index + L2FLOOD_ERROR_L2FLOOD] += 1;
+
+ l2flood_process (vm, node, msm,
+ &em->counters[node_counter_base_index], b0,
+ &sw_if_index0, &key0, &bucket0, &result0, &next0);
+
+ if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
+ (b0->flags & VLIB_BUFFER_IS_TRACED)))
+ {
+ l2flood_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
+ ethernet_header_t *h0 = vlib_buffer_get_current (b0);
+ t->sw_if_index = sw_if_index0;
+ t->bd_index = vnet_buffer (b0)->l2.bd_index;
+ clib_memcpy (t->src, h0->src_address, 6);
+ clib_memcpy (t->dst, h0->dst_address, 6);
+ }
+
+ /* 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 (l2flood_node,static) = {
+ .function = l2flood_node_fn,
+ .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",
+ },
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (l2flood_node, l2flood_node_fn)
+ 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 ();
+
+ /* 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 0;
+}
+
+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);
+}
+
+
+/**
+ * Set subinterface flood enable/disable.
+ * The CLI format is:
+ * set interface l2 flood <interface> [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}
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (int_flood_cli, static) = {
+ .path = "set interface l2 flood",
+ .short_help = "set interface l2 flood <interface> [disable]",
+ .function = int_flood,
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
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