<commit_before>/*
 * l2_input.c : layer 2 input packet 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 <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vnet/pg/pg.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/ethernet/packet.h>
#include <vnet/ip/ip_packet.h>
#include <vnet/ip/ip4_packet.h>
#include <vnet/ip/ip6_packet.h>
#include <vlib/cli.h>
#include <vnet/l2/l2_input.h>
#include <vnet/l2/l2_output.h>
#include <vnet/l2/feat_bitmap.h>
#include <vnet/l2/l2_bvi.h>
#include <vnet/l2/l2_fib.h>

#include <vppinfra/error.h>
#include <vppinfra/hash.h>
#include <vppinfra/cache.h>

extern clib_error_t *
ethernet_arp_hw_interface_link_up_down (vnet_main_t * vnm,
                                        u32 hw_if_index,
                                        u32 flags);

// Feature graph node names
static char * l2input_feat_names[] = {
#define _(sym,name) name,
  foreach_l2input_feat
#undef _
};

char **l2input_get_feat_names(void) {
  return l2input_feat_names;
}


typedef struct {
  /* per-pkt trace data */ 
  u8 src[6];
  u8 dst[6];
  u32 next_index;
  u32 sw_if_index;
} l2input_trace_t;

/* packet trace format function */
static u8 * format_l2input_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 *);
  l2input_trace_t * t = va_arg (*args, l2input_trace_t *);
  
  s = format (s, "l2-input: sw_if_index %d dst %U src %U",
	      t->sw_if_index,
              format_ethernet_address, t->dst,
              format_ethernet_address, t->src);
  return s;
}

l2input_main_t l2input_main;

static vlib_node_registration_t l2input_node;

#define foreach_l2input_error			\
_(L2INPUT,     "L2 input packets")		\
_(DROP,        "L2 input drops")

typedef enum {
#define _(sym,str) L2INPUT_ERROR_##sym,
  foreach_l2input_error
#undef _
  L2INPUT_N_ERROR,
} l2input_error_t;

static char * l2input_error_strings[] = {
#define _(sym,string) string,
  foreach_l2input_error
#undef _
};

typedef enum {			/*  */
  L2INPUT_NEXT_LEARN,
  L2INPUT_NEXT_FWD,
  L2INPUT_NEXT_DROP,
  L2INPUT_N_NEXT,
} l2input_next_t;


static_always_inline void
classify_and_dispatch (vlib_main_t * vm,
                       vlib_node_runtime_t * node,
                       u32 cpu_index, 
                       l2input_main_t * msm,
	               vlib_buffer_t * b0,
		       u32 *next0)
{
  // Load L2 input feature struct
  // Load bridge domain struct
  // Parse ethernet header to determine unicast/mcast/broadcast
  // take L2 input stat
  // classify packet as IP/UDP/TCP, control, other
  // mask feature bitmap
  // go to first node in bitmap
  // Later: optimize VTM
  //
  // For L2XC, 
  //   set tx sw-if-handle
 
  u8 mcast_dmac; 
  __attribute__((unused)) u8 l2bcast;
  __attribute__((unused)) u8 l2mcast;
  __attribute__((unused)) u8 l2_stat_kind;
  u16 ethertype;
  u8 protocol;
  l2_input_config_t *config;
  l2_bridge_domain_t *bd_config;
  u16 bd_index0;
  u32 feature_bitmap;
  u32 feat_mask;
  ethernet_header_t * h0;
  u8 * l3h0;
  u32 sw_if_index0;
  u8 bvi_flg = 0;

#define get_u32(addr) ( *((u32 *)(addr)) )
#define get_u16(addr) ( *((u16 *)(addr)) )
#define STATS_IF_LAYER2_UCAST_INPUT_CNT 0
#define STATS_IF_LAYER2_MCAST_INPUT_CNT 1
#define STATS_IF_LAYER2_BCAST_INPUT_CNT 2

  // Check for from-BVI processing
  // When we come from ethernet-input, TX is ~0
  if (PREDICT_FALSE (vnet_buffer(b0)->sw_if_index[VLIB_TX] != ~0)) {
    // Set up for a from-bvi packet
    bvi_to_l2 (vm, 
               msm->vnet_main, 
               cpu_index, 
               b0, 
               vnet_buffer(b0)->sw_if_index[VLIB_TX]);
    bvi_flg = 1;
  }

  // The RX interface can be changed by bvi_to_l2()
  sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];

  h0 = vlib_buffer_get_current (b0);
  l3h0 = (u8 *)h0 + vnet_buffer(b0)->l2.l2_len;

  // Determine L3 packet type. Only need to check the common types.
  // Used to filter out features that don't apply to common packets.
  ethertype = clib_net_to_host_u16(get_u16(l3h0 - 2));
  if (ethertype == ETHERNET_TYPE_IP4) {
    protocol = ((ip4_header_t *)l3h0)->protocol;
    if ((protocol == IP_PROTOCOL_UDP) ||
        (protocol == IP_PROTOCOL_TCP)) {
      feat_mask = IP_UDP_TCP_FEAT_MASK;
    } else {
      feat_mask = IP4_FEAT_MASK;
    }
  } else if (ethertype == ETHERNET_TYPE_IP6) {
    protocol = ((ip6_header_t *)l3h0)->protocol;
    // Don't bother checking for extension headers for now
    if ((protocol == IP_PROTOCOL_UDP) ||
        (protocol == IP_PROTOCOL_TCP)) {
      feat_mask = IP_UDP_TCP_FEAT_MASK;
    } else {
      feat_mask = IP6_FEAT_MASK;
    }
  } else if (ethertype == ETHERNET_TYPE_MPLS_UNICAST) {
    feat_mask = IP6_FEAT_MASK;
  } else {
    // allow all features
    feat_mask = ~0;
  } 

  // determine layer2 kind for stat and mask
  mcast_dmac = ethernet_address_cast(h0->dst_address);
  l2bcast = 0;
  l2mcast = 0;
  l2_stat_kind = STATS_IF_LAYER2_UCAST_INPUT_CNT;
  if (PREDICT_FALSE (mcast_dmac)) {
    u32 *dsthi = (u32 *) &h0->dst_address[0];
    u32 *dstlo = (u32 *) &h0->dst_address[2];

    // Disable bridge forwarding (flooding will execute instead if not xconnect)
    feat_mask &= ~(L2INPUT_FEAT_FWD | L2INPUT_FEAT_UU_FLOOD);
    if (ethertype != ETHERNET_TYPE_ARP) // Disable ARP-term for non-ARP packet
	feat_mask &= ~(L2INPUT_FEAT_ARP_TERM);

    // dest mac is multicast or broadcast
    if ((*dstlo == 0xFFFFFFFF) && (*dsthi == 0xFFFFFFFF)) { 
      // dest mac == FF:FF:FF:FF:FF:FF
      l2_stat_kind = STATS_IF_LAYER2_BCAST_INPUT_CNT;
      l2bcast=1;
    } else {
      l2_stat_kind = STATS_IF_LAYER2_MCAST_INPUT_CNT;
      l2mcast=1;
    }
  }
  // TODO: take l2 stat

  // Get config for the input interface
  config = vec_elt_at_index(msm->configs, sw_if_index0);

  // Save split horizon group, use 0 for BVI to make sure not dropped
  vnet_buffer(b0)->l2.shg = bvi_flg ? 0 : config->shg;

  if (config->xconnect) {
    // Set the output interface
    vnet_buffer(b0)->sw_if_index[VLIB_TX] = config->output_sw_if_index;

  } else {

    // Do bridge-domain processing
    bd_index0 = config->bd_index;
    // save BD ID for next feature graph nodes
    vnet_buffer(b0)->l2.bd_index = bd_index0;

    // Get config for the bridge domain interface
    bd_config = vec_elt_at_index(msm->bd_configs, bd_index0);

    // Process bridge domain feature enables.
    // To perform learning/flooding/forwarding, the corresponding bit
    // must be enabled in both the input interface config and in the
    // bridge domain config. In the bd_bitmap, bits for features other
    // than learning/flooding/forwarding should always be set.
    feat_mask = feat_mask & bd_config->feature_bitmap;
  }

  // mask out features from bitmap using packet type and bd config
  feature_bitmap = config->feature_bitmap & feat_mask;

  // save for next feature graph nodes
  vnet_buffer(b0)->l2.feature_bitmap = feature_bitmap;

  // Determine the next node
  *next0 = feat_bitmap_get_next_node_index(msm->feat_next_node_index,
                                           feature_bitmap);
}


static uword
l2input_node_fn (vlib_main_t * vm,
	         vlib_node_runtime_t * node,
	         vlib_frame_t * frame)
{
  u32 n_left_from, * from, * to_next;
  l2input_next_t next_index;
  l2input_main_t * msm = &l2input_main;
  vlib_node_t *n = vlib_get_node (vm, l2input_node.index);
  u32 node_counter_base_index = n->error_heap_index;
  vlib_error_main_t * em = &vm->error_main;
  u32 cpu_index = os_get_cpu_number();

  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;
          
	  /* Prefetch next iteration. */
	  {
	    vlib_buffer_t * p2, * p3, * p4 , * p5;
            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_RX];
            sw_if_index3 = vnet_buffer(p3)->sw_if_index[VLIB_RX];
            CLIB_PREFETCH (&msm->configs[sw_if_index2], CLIB_CACHE_LINE_BYTES, LOAD);
            CLIB_PREFETCH (&msm->configs[sw_if_index3], CLIB_CACHE_LINE_BYTES, LOAD);

            // Don't bother prefetching the bridge-domain config (which 
            // depends on the input config above). Only a small number of
            // bridge domains are expected. Plus the structure is small
            // and several fit in a cache line.
          }

          /* 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);

          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE))) {
            /* 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];

            if (b0->flags & VLIB_BUFFER_IS_TRACED) {
              ethernet_header_t * h0 = vlib_buffer_get_current (b0);
              l2input_trace_t *t = 
                      vlib_add_trace (vm, node, b0, sizeof (*t));
              t->sw_if_index = sw_if_index0;
              memcpy(t->src, h0->src_address, 6);
              memcpy(t->dst, h0->dst_address, 6);
            }
            if (b1->flags & VLIB_BUFFER_IS_TRACED) {
              ethernet_header_t * h1 = vlib_buffer_get_current (b1);
              l2input_trace_t *t = 
                      vlib_add_trace (vm, node, b1, sizeof (*t));
              t->sw_if_index = sw_if_index1;
              memcpy(t->src, h1->src_address, 6);
              memcpy(t->dst, h1->dst_address, 6);
            }
          }

          em->counters[node_counter_base_index + L2INPUT_ERROR_L2INPUT] += 2;

	  classify_and_dispatch (vm,
                                 node,
                                 cpu_index, 
                                 msm,
				 b0,
				 &next0);

	  classify_and_dispatch (vm,
                                 node,
                                 cpu_index, 
                                 msm,
				 b1,
				 &next1);

          /* 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;
 
          /* 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);

          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) 
                            && (b0->flags & VLIB_BUFFER_IS_TRACED))) {
            ethernet_header_t * h0 = vlib_buffer_get_current (b0);
            l2input_trace_t *t = 
               vlib_add_trace (vm, node, b0, sizeof (*t));
            sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
            t->sw_if_index = sw_if_index0;
            memcpy(t->src, h0->src_address, 6);
            memcpy(t->dst, h0->dst_address, 6);
          }

          em->counters[node_counter_base_index + L2INPUT_ERROR_L2INPUT] += 1;

	  classify_and_dispatch (vm,
                                 node,
                                 cpu_index, 
                                 msm,
				 b0,
				 &next0);

          /* 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;
}


VLIB_REGISTER_NODE (l2input_node,static) = {
  .function = l2input_node_fn,
  .name = "l2-input",
  .vector_size = sizeof (u32),
  .format_trace = format_l2input_trace,
  .format_buffer = format_ethernet_header_with_length,
  .type = VLIB_NODE_TYPE_INTERNAL,
  
  .n_errors = ARRAY_LEN(l2input_error_strings),
  .error_strings = l2input_error_strings,

  .n_next_nodes = L2INPUT_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes = {
       [L2INPUT_NEXT_LEARN] = "l2-learn",
       [L2INPUT_NEXT_FWD]   = "l2-fwd",
       [L2INPUT_NEXT_DROP]  = "error-drop",
  },
};

clib_error_t *l2input_init (vlib_main_t *vm)
{
  l2input_main_t * mp = &l2input_main;
 
  mp->vlib_main = vm;
  mp->vnet_main = vnet_get_main();

  // Get packets RX'd from L2 interfaces
  ethernet_register_l2_input (vm, l2input_node.index);

  // Create the config vector
  vec_validate(mp->configs, 100);  
  // create 100 sw interface entries and zero them

  // Initialize the feature next-node indexes
  feat_bitmap_init_next_nodes(vm,
                              l2input_node.index,
                              L2INPUT_N_FEAT,
                              l2input_get_feat_names(),
                              mp->feat_next_node_index);

  return 0;
}

VLIB_INIT_FUNCTION (l2input_init);


// Get a pointer to the config for the given interface
l2_input_config_t * l2input_intf_config (u32 sw_if_index)
{
  l2input_main_t * mp = &l2input_main;
 
  vec_validate(mp->configs, sw_if_index);  
  return vec_elt_at_index(mp->configs, sw_if_index);
}

// Enable (or disable) the feature in the bitmap for the given interface
u32 l2input_intf_bitmap_enable (u32 sw_if_index,
                                 u32 feature_bitmap,
                                 u32 enable)
{
  l2input_main_t * mp = &l2input_main;
  l2_input_config_t *config;
 
  vec_validate(mp->configs, sw_if_index);  
  config = vec_elt_at_index(mp->configs, sw_if_index);

  if (enable) {
    config->feature_bitmap |= feature_bitmap;
  } else {
    config->feature_bitmap &= ~feature_bitmap;
  }

  return config->feature_bitmap;
}



// Set the subinterface to run in l2 or l3 mode.
// for L3 mode, just the sw_if_index is specified
// for bridged mode, the bd id and bvi flag are also specified
// for xconnect mode, the peer sw_if_index is also specified
// Return 0 if ok, or non-0 if there was an error

u32 set_int_l2_mode (vlib_main_t * vm,
                     vnet_main_t * vnet_main,
                     u32 mode,
                     u32 sw_if_index,
                     u32 bd_index, // for bridged interface
                     u32 bvi,   // the bridged interface is the BVI
                     u32 shg,   // the bridged interface's split horizon group
                     u32 xc_sw_if_index) // peer interface for xconnect
{
  l2input_main_t * mp = &l2input_main;
  vnet_main_t * vnm = vnet_get_main();
  vnet_hw_interface_t * hi;
  l2_output_config_t * out_config;
  l2_input_config_t * config;
  l2_bridge_domain_t * bd_config;
  l2_flood_member_t member;
  u64 mac;
  i32 l2_if_adjust = 0; 

  hi = vnet_get_sup_hw_interface (vnet_main, sw_if_index);

  vec_validate(mp->configs, sw_if_index);  
  config = vec_elt_at_index(mp->configs, sw_if_index);

  if (config->bridge) {
    // Interface is already in bridge mode. Undo the existing config.
    bd_config = vec_elt_at_index(mp->bd_configs, config->bd_index);

    // remove interface from flood vector
    bd_remove_member (bd_config, sw_if_index);

    // undo any BVI-related config
    if (bd_config->bvi_sw_if_index == sw_if_index) {
      bd_config->bvi_sw_if_index = ~0;
      config->bvi = 0;

      // restore output node
      hi->output_node_index = bd_config->saved_bvi_output_node_index;

      // delete the l2fib entry for the bvi interface
      mac = *((u64 *)hi->hw_address);
      l2fib_del_entry (mac, config->bd_index);
    } 
    l2_if_adjust--;
  } else if (config->xconnect) {
    l2_if_adjust--;
  }

  // Initialize the l2-input configuration for the interface
  if (mode == MODE_L3) {
    config->xconnect = 0;
    config->bridge = 0;
    config->shg = 0;
    config->bd_index = 0;
    config->feature_bitmap = L2INPUT_FEAT_DROP;
  } else if (mode == MODE_L2_CLASSIFY) {
      config->xconnect = 1;
      config->bridge = 0;
      config->output_sw_if_index = xc_sw_if_index;

      // Make sure last-chance drop is configured
      config->feature_bitmap |= L2INPUT_FEAT_DROP | L2INPUT_FEAT_CLASSIFY;

      // Make sure bridging features are disabled
      config->feature_bitmap &= 
          ~(L2INPUT_FEAT_LEARN | L2INPUT_FEAT_FWD | L2INPUT_FEAT_FLOOD);
      shg = 0; // not used in xconnect

      // Insure all packets go to ethernet-input
      ethernet_set_rx_redirect (vnet_main, hi, 1);
  } else {

    if (mode == MODE_L2_BRIDGE) {
        /* 
         * Remove a check that the interface must be an Ethernet.
         * Specifically so we can bridge to L3 tunnel interfaces.
         * Here's the check:
         * if (hi->hw_class_index != ethernet_hw_interface_class.index)
         * 
         */
        if (!hi)
            return MODE_ERROR_ETH;  // non-ethernet

      config->xconnect = 0;
      config->bridge = 1;
      config->bd_index = bd_index;

      // Enable forwarding, flooding, learning and ARP termination by default
      // (note that ARP term is disabled on BD feature bitmap by default)
      config->feature_bitmap |= L2INPUT_FEAT_FWD | L2INPUT_FEAT_UU_FLOOD | 
	  L2INPUT_FEAT_FLOOD | L2INPUT_FEAT_LEARN | L2INPUT_FEAT_ARP_TERM;

      // Make sure last-chance drop is configured
      config->feature_bitmap |= L2INPUT_FEAT_DROP;

      // Make sure xconnect is disabled
      config->feature_bitmap &= ~L2INPUT_FEAT_XCONNECT;

      // Set up bridge domain
      vec_validate(mp->bd_configs, bd_index);  
      bd_config = vec_elt_at_index(mp->bd_configs, bd_index);
      bd_validate (bd_config);

      // TODO: think: add l2fib entry even for non-bvi interface?
 
      // Do BVI interface initializations
      if (bvi) {
        // insure BD has no bvi interface (or replace that one with this??)
        if (bd_config->bvi_sw_if_index != ~0) {
          return MODE_ERROR_BVI_DEF; // bd already has a bvi interface
        } 
        bd_config->bvi_sw_if_index = sw_if_index;
        config->bvi = 1;

        // make BVI outputs go to l2-input
        bd_config->saved_bvi_output_node_index = hi->output_node_index;
        hi->output_node_index = l2input_node.index;

        // create the l2fib entry for the bvi interface
        mac = *((u64 *)hi->hw_address);
        l2fib_add_entry (mac, bd_index, sw_if_index, 1, 0, 1);  // static + bvi

        // Disable learning by default. no use since l2fib entry is static.
        config->feature_bitmap &= ~L2INPUT_FEAT_LEARN;

        // Add BVI to arp_input_next_index_by_hw_if_index table so arp-input
        // node can send out ARP response via BVI to BD
        ethernet_arp_hw_interface_link_up_down(vnet_main, hi->hw_if_index, 0);
 
      }

      // Add interface to bridge-domain flood vector<commit_msg>Fix IPv6 NDP and bridge BVI and restore NDP and ARP when BVI move is changed.<commit_after>/*
 * l2_input.c : layer 2 input packet 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 <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vnet/pg/pg.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/ethernet/packet.h>
#include <vnet/ip/ip_packet.h>
#include <vnet/ip/ip4_packet.h>
#include <vnet/ip/ip6_packet.h>
#include <vlib/cli.h>
#include <vnet/l2/l2_input.h>
#include <vnet/l2/l2_output.h>
#include <vnet/l2/feat_bitmap.h>
#include <vnet/l2/l2_bvi.h>
#include <vnet/l2/l2_fib.h>

#include <vppinfra/error.h>
#include <vppinfra/hash.h>
#include <vppinfra/cache.h>

extern clib_error_t *
ethernet_arp_hw_interface_link_up_down (vnet_main_t * vnm,
                                        u32 hw_if_index,
                                        u32 flags);

extern clib_error_t *
ip6_discover_neighbor_hw_interface_link_up_down (vnet_main_t * vnm,
                                                 u32 hw_if_index,
                                                 u32 flags);

// Feature graph node names
static char * l2input_feat_names[] = {
#define _(sym,name) name,
  foreach_l2input_feat
#undef _
};

char **l2input_get_feat_names(void) {
  return l2input_feat_names;
}


typedef struct {
  /* per-pkt trace data */ 
  u8 src[6];
  u8 dst[6];
  u32 next_index;
  u32 sw_if_index;
} l2input_trace_t;

/* packet trace format function */
static u8 * format_l2input_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 *);
  l2input_trace_t * t = va_arg (*args, l2input_trace_t *);
  
  s = format (s, "l2-input: sw_if_index %d dst %U src %U",
	      t->sw_if_index,
              format_ethernet_address, t->dst,
              format_ethernet_address, t->src);
  return s;
}

l2input_main_t l2input_main;

static vlib_node_registration_t l2input_node;

#define foreach_l2input_error			\
_(L2INPUT,     "L2 input packets")		\
_(DROP,        "L2 input drops")

typedef enum {
#define _(sym,str) L2INPUT_ERROR_##sym,
  foreach_l2input_error
#undef _
  L2INPUT_N_ERROR,
} l2input_error_t;

static char * l2input_error_strings[] = {
#define _(sym,string) string,
  foreach_l2input_error
#undef _
};

typedef enum {			/*  */
  L2INPUT_NEXT_LEARN,
  L2INPUT_NEXT_FWD,
  L2INPUT_NEXT_DROP,
  L2INPUT_N_NEXT,
} l2input_next_t;


static_always_inline void
classify_and_dispatch (vlib_main_t * vm,
                       vlib_node_runtime_t * node,
                       u32 cpu_index, 
                       l2input_main_t * msm,
	               vlib_buffer_t * b0,
		       u32 *next0)
{
  // Load L2 input feature struct
  // Load bridge domain struct
  // Parse ethernet header to determine unicast/mcast/broadcast
  // take L2 input stat
  // classify packet as IP/UDP/TCP, control, other
  // mask feature bitmap
  // go to first node in bitmap
  // Later: optimize VTM
  //
  // For L2XC, 
  //   set tx sw-if-handle
 
  u8 mcast_dmac; 
  __attribute__((unused)) u8 l2bcast;
  __attribute__((unused)) u8 l2mcast;
  __attribute__((unused)) u8 l2_stat_kind;
  u16 ethertype;
  u8 protocol;
  l2_input_config_t *config;
  l2_bridge_domain_t *bd_config;
  u16 bd_index0;
  u32 feature_bitmap;
  u32 feat_mask;
  ethernet_header_t * h0;
  u8 * l3h0;
  u32 sw_if_index0;
  u8 bvi_flg = 0;

#define get_u32(addr) ( *((u32 *)(addr)) )
#define get_u16(addr) ( *((u16 *)(addr)) )
#define STATS_IF_LAYER2_UCAST_INPUT_CNT 0
#define STATS_IF_LAYER2_MCAST_INPUT_CNT 1
#define STATS_IF_LAYER2_BCAST_INPUT_CNT 2

  // Check for from-BVI processing
  // When we come from ethernet-input, TX is ~0
  if (PREDICT_FALSE (vnet_buffer(b0)->sw_if_index[VLIB_TX] != ~0)) {
    // Set up for a from-bvi packet
    bvi_to_l2 (vm, 
               msm->vnet_main, 
               cpu_index, 
               b0, 
               vnet_buffer(b0)->sw_if_index[VLIB_TX]);
    bvi_flg = 1;
  }

  // The RX interface can be changed by bvi_to_l2()
  sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];

  h0 = vlib_buffer_get_current (b0);
  l3h0 = (u8 *)h0 + vnet_buffer(b0)->l2.l2_len;

  // Determine L3 packet type. Only need to check the common types.
  // Used to filter out features that don't apply to common packets.
  ethertype = clib_net_to_host_u16(get_u16(l3h0 - 2));
  if (ethertype == ETHERNET_TYPE_IP4) {
    protocol = ((ip4_header_t *)l3h0)->protocol;
    if ((protocol == IP_PROTOCOL_UDP) ||
        (protocol == IP_PROTOCOL_TCP)) {
      feat_mask = IP_UDP_TCP_FEAT_MASK;
    } else {
      feat_mask = IP4_FEAT_MASK;
    }
  } else if (ethertype == ETHERNET_TYPE_IP6) {
    protocol = ((ip6_header_t *)l3h0)->protocol;
    // Don't bother checking for extension headers for now
    if ((protocol == IP_PROTOCOL_UDP) ||
        (protocol == IP_PROTOCOL_TCP)) {
      feat_mask = IP_UDP_TCP_FEAT_MASK;
    } else {
      feat_mask = IP6_FEAT_MASK;
    }
  } else if (ethertype == ETHERNET_TYPE_MPLS_UNICAST) {
    feat_mask = IP6_FEAT_MASK;
  } else {
    // allow all features
    feat_mask = ~0;
  } 

  // determine layer2 kind for stat and mask
  mcast_dmac = ethernet_address_cast(h0->dst_address);
  l2bcast = 0;
  l2mcast = 0;
  l2_stat_kind = STATS_IF_LAYER2_UCAST_INPUT_CNT;
  if (PREDICT_FALSE (mcast_dmac)) {
    u32 *dsthi = (u32 *) &h0->dst_address[0];
    u32 *dstlo = (u32 *) &h0->dst_address[2];

    // Disable bridge forwarding (flooding will execute instead if not xconnect)
    feat_mask &= ~(L2INPUT_FEAT_FWD | L2INPUT_FEAT_UU_FLOOD);
    if (ethertype != ETHERNET_TYPE_ARP) // Disable ARP-term for non-ARP packet
	feat_mask &= ~(L2INPUT_FEAT_ARP_TERM);

    // dest mac is multicast or broadcast
    if ((*dstlo == 0xFFFFFFFF) && (*dsthi == 0xFFFFFFFF)) { 
      // dest mac == FF:FF:FF:FF:FF:FF
      l2_stat_kind = STATS_IF_LAYER2_BCAST_INPUT_CNT;
      l2bcast=1;
    } else {
      l2_stat_kind = STATS_IF_LAYER2_MCAST_INPUT_CNT;
      l2mcast=1;
    }
  }
  // TODO: take l2 stat

  // Get config for the input interface
  config = vec_elt_at_index(msm->configs, sw_if_index0);

  // Save split horizon group, use 0 for BVI to make sure not dropped
  vnet_buffer(b0)->l2.shg = bvi_flg ? 0 : config->shg;

  if (config->xconnect) {
    // Set the output interface
    vnet_buffer(b0)->sw_if_index[VLIB_TX] = config->output_sw_if_index;

  } else {

    // Do bridge-domain processing
    bd_index0 = config->bd_index;
    // save BD ID for next feature graph nodes
    vnet_buffer(b0)->l2.bd_index = bd_index0;

    // Get config for the bridge domain interface
    bd_config = vec_elt_at_index(msm->bd_configs, bd_index0);

    // Process bridge domain feature enables.
    // To perform learning/flooding/forwarding, the corresponding bit
    // must be enabled in both the input interface config and in the
    // bridge domain config. In the bd_bitmap, bits for features other
    // than learning/flooding/forwarding should always be set.
    feat_mask = feat_mask & bd_config->feature_bitmap;
  }

  // mask out features from bitmap using packet type and bd config
  feature_bitmap = config->feature_bitmap & feat_mask;

  // save for next feature graph nodes
  vnet_buffer(b0)->l2.feature_bitmap = feature_bitmap;

  // Determine the next node
  *next0 = feat_bitmap_get_next_node_index(msm->feat_next_node_index,
                                           feature_bitmap);
}


static uword
l2input_node_fn (vlib_main_t * vm,
	         vlib_node_runtime_t * node,
	         vlib_frame_t * frame)
{
  u32 n_left_from, * from, * to_next;
  l2input_next_t next_index;
  l2input_main_t * msm = &l2input_main;
  vlib_node_t *n = vlib_get_node (vm, l2input_node.index);
  u32 node_counter_base_index = n->error_heap_index;
  vlib_error_main_t * em = &vm->error_main;
  u32 cpu_index = os_get_cpu_number();

  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;
          
	  /* Prefetch next iteration. */
	  {
	    vlib_buffer_t * p2, * p3, * p4 , * p5;
            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_RX];
            sw_if_index3 = vnet_buffer(p3)->sw_if_index[VLIB_RX];
            CLIB_PREFETCH (&msm->configs[sw_if_index2], CLIB_CACHE_LINE_BYTES, LOAD);
            CLIB_PREFETCH (&msm->configs[sw_if_index3], CLIB_CACHE_LINE_BYTES, LOAD);

            // Don't bother prefetching the bridge-domain config (which 
            // depends on the input config above). Only a small number of
            // bridge domains are expected. Plus the structure is small
            // and several fit in a cache line.
          }

          /* 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);

          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE))) {
            /* 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];

            if (b0->flags & VLIB_BUFFER_IS_TRACED) {
              ethernet_header_t * h0 = vlib_buffer_get_current (b0);
              l2input_trace_t *t = 
                      vlib_add_trace (vm, node, b0, sizeof (*t));
              t->sw_if_index = sw_if_index0;
              memcpy(t->src, h0->src_address, 6);
              memcpy(t->dst, h0->dst_address, 6);
            }
            if (b1->flags & VLIB_BUFFER_IS_TRACED) {
              ethernet_header_t * h1 = vlib_buffer_get_current (b1);
              l2input_trace_t *t = 
                      vlib_add_trace (vm, node, b1, sizeof (*t));
              t->sw_if_index = sw_if_index1;
              memcpy(t->src, h1->src_address, 6);
              memcpy(t->dst, h1->dst_address, 6);
            }
          }

          em->counters[node_counter_base_index + L2INPUT_ERROR_L2INPUT] += 2;

	  classify_and_dispatch (vm,
                                 node,
                                 cpu_index, 
                                 msm,
				 b0,
				 &next0);

	  classify_and_dispatch (vm,
                                 node,
                                 cpu_index, 
                                 msm,
				 b1,
				 &next1);

          /* 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;
 
          /* 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);

          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) 
                            && (b0->flags & VLIB_BUFFER_IS_TRACED))) {
            ethernet_header_t * h0 = vlib_buffer_get_current (b0);
            l2input_trace_t *t = 
               vlib_add_trace (vm, node, b0, sizeof (*t));
            sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
            t->sw_if_index = sw_if_index0;
            memcpy(t->src, h0->src_address, 6);
            memcpy(t->dst, h0->dst_address, 6);
          }

          em->counters[node_counter_base_index + L2INPUT_ERROR_L2INPUT] += 1;

	  classify_and_dispatch (vm,
                                 node,
                                 cpu_index, 
                                 msm,
				 b0,
				 &next0);

          /* 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;
}


VLIB_REGISTER_NODE (l2input_node,static) = {
  .function = l2input_node_fn,
  .name = "l2-input",
  .vector_size = sizeof (u32),
  .format_trace = format_l2input_trace,
  .format_buffer = format_ethernet_header_with_length,
  .type = VLIB_NODE_TYPE_INTERNAL,
  
  .n_errors = ARRAY_LEN(l2input_error_strings),
  .error_strings = l2input_error_strings,

  .n_next_nodes = L2INPUT_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes = {
       [L2INPUT_NEXT_LEARN] = "l2-learn",
       [L2INPUT_NEXT_FWD]   = "l2-fwd",
       [L2INPUT_NEXT_DROP]  = "error-drop",
  },
};

clib_error_t *l2input_init (vlib_main_t *vm)
{
  l2input_main_t * mp = &l2input_main;
 
  mp->vlib_main = vm;
  mp->vnet_main = vnet_get_main();

  // Get packets RX'd from L2 interfaces
  ethernet_register_l2_input (vm, l2input_node.index);

  // Create the config vector
  vec_validate(mp->configs, 100);  
  // create 100 sw interface entries and zero them

  // Initialize the feature next-node indexes
  feat_bitmap_init_next_nodes(vm,
                              l2input_node.index,
                              L2INPUT_N_FEAT,
                              l2input_get_feat_names(),
                              mp->feat_next_node_index);

  return 0;
}

VLIB_INIT_FUNCTION (l2input_init);


// Get a pointer to the config for the given interface
l2_input_config_t * l2input_intf_config (u32 sw_if_index)
{
  l2input_main_t * mp = &l2input_main;
 
  vec_validate(mp->configs, sw_if_index);  
  return vec_elt_at_index(mp->configs, sw_if_index);
}

// Enable (or disable) the feature in the bitmap for the given interface
u32 l2input_intf_bitmap_enable (u32 sw_if_index,
                                 u32 feature_bitmap,
                                 u32 enable)
{
  l2input_main_t * mp = &l2input_main;
  l2_input_config_t *config;
 
  vec_validate(mp->configs, sw_if_index);  
  config = vec_elt_at_index(mp->configs, sw_if_index);

  if (enable) {
    config->feature_bitmap |= feature_bitmap;
  } else {
    config->feature_bitmap &= ~feature_bitmap;
  }

  return config->feature_bitmap;
}



// Set the subinterface to run in l2 or l3 mode.
// for L3 mode, just the sw_if_index is specified
// for bridged mode, the bd id and bvi flag are also specified
// for xconnect mode, the peer sw_if_index is also specified
// Return 0 if ok, or non-0 if there was an error

u32 set_int_l2_mode (vlib_main_t * vm,
                     vnet_main_t * vnet_main,
                     u32 mode,
                     u32 sw_if_index,
                     u32 bd_index, // for bridged interface
                     u32 bvi,   // the bridged interface is the BVI
                     u32 shg,   // the bridged interface's split horizon group
                     u32 xc_sw_if_index) // peer interface for xconnect
{
  l2input_main_t * mp = &l2input_main;
  vnet_main_t * vnm = vnet_get_main();
  vnet_hw_interface_t * hi;
  l2_output_config_t * out_config;
  l2_input_config_t * config;
  l2_bridge_domain_t * bd_config;
  l2_flood_member_t member;
  u64 mac;
  i32 l2_if_adjust = 0; 

  hi = vnet_get_sup_hw_interface (vnet_main, sw_if_index);

  vec_validate(mp->configs, sw_if_index);  
  config = vec_elt_at_index(mp->configs, sw_if_index);

  if (config->bridge) {
    // Interface is already in bridge mode. Undo the existing config.
    bd_config = vec_elt_at_index(mp->bd_configs, config->bd_index);

    // remove interface from flood vector
    bd_remove_member (bd_config, sw_if_index);

    // undo any BVI-related config
    if (bd_config->bvi_sw_if_index == sw_if_index) {
      bd_config->bvi_sw_if_index = ~0;
      config->bvi = 0;

      // restore output node
      hi->output_node_index = bd_config->saved_bvi_output_node_index;

      // delete the l2fib entry for the bvi interface
      mac = *((u64 *)hi->hw_address);
      l2fib_del_entry (mac, config->bd_index);

      // Let ARP and NDP know that the output node index changed
      ethernet_arp_hw_interface_link_up_down(vnet_main, hi->hw_if_index, 0);
      ip6_discover_neighbor_hw_interface_link_up_down(vnet_main, hi->hw_if_index, 0);
    } 
    l2_if_adjust--;
  } else if (config->xconnect) {
    l2_if_adjust--;
  }

  // Initialize the l2-input configuration for the interface
  if (mode == MODE_L3) {
    config->xconnect = 0;
    config->bridge = 0;
    config->shg = 0;
    config->bd_index = 0;
    config->feature_bitmap = L2INPUT_FEAT_DROP;
  } else if (mode == MODE_L2_CLASSIFY) {
      config->xconnect = 1;
      config->bridge = 0;
      config->output_sw_if_index = xc_sw_if_index;

      // Make sure last-chance drop is configured
      config->feature_bitmap |= L2INPUT_FEAT_DROP | L2INPUT_FEAT_CLASSIFY;

      // Make sure bridging features are disabled
      config->feature_bitmap &= 
          ~(L2INPUT_FEAT_LEARN | L2INPUT_FEAT_FWD | L2INPUT_FEAT_FLOOD);
      shg = 0; // not used in xconnect

      // Insure all packets go to ethernet-input
      ethernet_set_rx_redirect (vnet_main, hi, 1);
  } else {

    if (mode == MODE_L2_BRIDGE) {
        /* 
         * Remove a check that the interface must be an Ethernet.
         * Specifically so we can bridge to L3 tunnel interfaces.
         * Here's the check:
         * if (hi->hw_class_index != ethernet_hw_interface_class.index)
         * 
         */
        if (!hi)
            return MODE_ERROR_ETH;  // non-ethernet

      config->xconnect = 0;
      config->bridge = 1;
      config->bd_index = bd_index;

      // Enable forwarding, flooding, learning and ARP termination by default
      // (note that ARP term is disabled on BD feature bitmap by default)
      config->feature_bitmap |= L2INPUT_FEAT_FWD | L2INPUT_FEAT_UU_FLOOD | 
	  L2INPUT_FEAT_FLOOD | L2INPUT_FEAT_LEARN | L2INPUT_FEAT_ARP_TERM;

      // Make sure last-chance drop is configured
      config->feature_bitmap |= L2INPUT_FEAT_DROP;

      // Make sure xconnect is disabled
      config->feature_bitmap &= ~L2INPUT_FEAT_XCONNECT;

      // Set up bridge domain
      vec_validate(mp->bd_configs, bd_index);  
      bd_config = vec_elt_at_index(mp->bd_configs, bd_index);
      bd_validate (bd_config);

      // TODO: think: add l2fib entry even for non-bvi interface?
 
      // Do BVI interface initializations
      if (bvi) {
        // insure BD has no bvi interface (or replace that one with this??)
        if (bd_config->bvi_sw_if_index != ~0) {
          return MODE_ERROR_BVI_DEF; // bd already has a bvi interface
        } 
        bd_config->bvi_sw_if_index = sw_if_index;
        config->bvi = 1;

        // make BVI outputs go to l2-input
        bd_config->saved_bvi_output_node_index = hi->output_node_index;
        hi->output_node_index = l2input_node.index;

        // create the l2fib entry for the bvi interface
        mac = *((u64 *)hi->hw_address);
        l2fib_add_entry (mac, bd_index, sw_if_index, 1, 0, 1);  // static + bvi

        // Disable learning by default. no use since l2fib entry is static.
        config->feature_bitmap &= ~L2INPUT_FEAT_LEARN;

        // Let ARP and NDP know that the output_index_node changed so they
        // can send requests via BVI to BD
        ethernet_arp_hw_interface_link_up_down(vnet_main, hi->hw_if_index, 0);
        ip6_discover_neighbor_hw_interface_link_up_down(vnet_main, hi->hw_if_index, 0);
      }

      // Add interface to bridge-domain flood vector
{'fraction_non_alphanumeric': 0.09782764382907615, 'fraction_numerical': 0.023561709238481738, 'mean_word_length': 2.474701393497014, 'pattern_counts': {'":': 0, '<': 37, '<?xml version=': 0, '>': 278, 'https://': 0, 'lorem ipsum': 0, 'www.': 2, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 4, 'word_list_counts': {'cursed_substrings.json': 46, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '1038863', 'n_tokens_mistral': 15656, 'n_tokens_neox': 14852, 'n_words': 3456}