text: /*
   * Copyright (c) 2015 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 <vnet/l2/l2_xcrw.h>
  
  /**
   * @file
   * General L2 / L3 cross-connect, used to set up
   * "L2 interface <--> your-favorite-tunnel-encap" tunnels.
   *
   * We set up a typical L2 cross-connect or (future) bridge
   * to hook L2 interface(s) up to the L3 stack in arbitrary ways.
   *
   * Each l2_xcrw adjacency specifies 3 things:
   *
   * 1. The next graph node (presumably in the L3 stack) to
   *    process the (L2 -> L3) packet
   *
   * 2. A new value for vnet_buffer(b)->sw_if_index[VLIB_TX]
   *    (i.e. a lookup FIB index),
   *
   * 3. A rewrite string to apply.
   *
   * Example: to cross-connect an L2 interface or (future) bridge
   * to an mpls-o-gre tunnel, set up the L2 rewrite string as shown in
   * mpls_gre_rewrite, and use "mpls-post-rewrite" to fix the
   * GRE IP header checksum and length fields.
   */
  
  typedef struct
  {
    u32 next_index;
    u32 tx_fib_index;
  } l2_xcrw_trace_t;
  
  /* packet trace format function */
  static u8 *
  format_l2_xcrw_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_xcrw_trace_t *t = va_arg (*args, l2_xcrw_trace_t *);
  
    s = format (s, "L2_XCRW: next index %d tx_fib_index %d",
  	      t->next_index, t->tx_fib_index);
    return s;
  }
  
  l2_xcrw_main_t l2_xcrw_main;
  
  static vlib_node_registration_t l2_xcrw_node;
  
  static char *l2_xcrw_error_strings[] = {
  #define _(sym,string) string,
    foreach_l2_xcrw_error
  #undef _
  };
  
  static uword
  l2_xcrw_node_fn (vlib_main_t * vm,
  		 vlib_node_runtime_t * node, vlib_frame_t * frame)
  {
    u32 n_left_from, *from, *to_next;
    l2_xcrw_next_t next_index;
    l2_xcrw_main_t *xcm = &l2_xcrw_main;
    vlib_node_t *n = vlib_get_node (vm, l2_xcrw_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;
    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 >= 4 && n_left_to_next >= 2)
  	{
  	  u32 bi0, bi1;
  	  vlib_buffer_t *b0, *b1;
  	  u32 next0, next1;
  	  u32 sw_if_index0, sw_if_index1;
  	  l2_xcrw_adjacency_t *adj0, *adj1;
  
  	  /* Prefetch next iteration. */
  	  {
  	    vlib_buffer_t *p2, *p3;
  
  	    p2 = vlib_get_buffer (vm, from[2]);
  	    p3 = vlib_get_buffer (vm, from[3]);
  
  	    vlib_prefetch_buffer_header (p2, LOAD);
  	    vlib_prefetch_buffer_header (p3, LOAD);
  
  	    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 */
  	  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);
  
  	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
  	  sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
  
  	  adj0 = vec_elt_at_index (xcm->adj_by_sw_if_index, sw_if_index0);
  	  adj1 = vec_elt_at_index (xcm->adj_by_sw_if_index, sw_if_index1);
  
  	  next0 = adj0->rewrite_header.next_index;
  	  vnet_buffer (b0)->sw_if_index[VLIB_TX] =
  	    adj0->rewrite_header.sw_if_index;
  
  	  next1 = adj1->rewrite_header.next_index;
  	  vnet_buffer (b1)->sw_if_index[VLIB_TX] =
  	    adj1->rewrite_header.sw_if_index;
  
  	  em->counters[node_counter_base_index + next1]++;
  
  	  if (PREDICT_TRUE (next0 > 0))
  	    {
  	      u8 *h0 = vlib_buffer_get_current (b0);
  	      vnet_rewrite_one_header (adj0[0], h0,
  				       adj0->rewrite_header.data_bytes);
  	      vlib_buffer_advance (b0, -adj0->rewrite_header.data_bytes);
  	      em->counters[node_counter_base_index + L2_XCRW_ERROR_FWD]++;
  	    }
  
  	  if (PREDICT_TRUE (next1 > 0))
  	    {
  	      u8 *h1 = vlib_buffer_get_current (b1);
  	      vnet_rewrite_one_header (adj1[0], h1,
  				       adj1->rewrite_header.data_bytes);
  	      vlib_buffer_advance (b1, -adj1->rewrite_header.data_bytes);
  	      em->counters[node_counter_base_index + L2_XCRW_ERROR_FWD]++;
  	    }
  
  
  	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
  	    {
  	      if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
  				 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
  		{
  		  l2_xcrw_trace_t *t =
  		    vlib_add_trace (vm, node, b0, sizeof (*t));
  		  t->next_index = next0;
  		  t->tx_fib_index = adj0->rewrite_header.sw_if_index;
  		}
  	      if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
  				 && (b1->flags & VLIB_BUFFER_IS_TRACED)))
  		{
  		  l2_xcrw_trace_t *t =
  		    vlib_add_trace (vm, node, b1, sizeof (*t));
  		  t->next_index = next1;
  		  t->tx_fib_index = adj1->rewrite_header.sw_if_index;
  		}
  	    }
  
  	  /* verify speculative enqueues, maybe switch current next frame */
  	  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;
  	  l2_xcrw_adjacency_t *adj0;
  
  	  /* 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];
  
  	  adj0 = vec_elt_at_index (xcm->adj_by_sw_if_index, sw_if_index0);
  
  	  next0 = adj0->rewrite_header.next_index;
  	  vnet_buffer (b0)->sw_if_index[VLIB_TX] =
  	    adj0->rewrite_header.sw_if_index;
  
  	  if (PREDICT_TRUE (next0 > 0))
  	    {
  	      u8 *h0 = vlib_buffer_get_current (b0);
  	      vnet_rewrite_one_header (adj0[0], h0,
  				       adj0->rewrite_header.data_bytes);
  	      vlib_buffer_advance (b0, -adj0->rewrite_header.data_bytes);
  	      em->counters[node_counter_base_index + L2_XCRW_ERROR_FWD]++;
  	    }
  
  	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
  			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
  	    {
  	      l2_xcrw_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
  	      t->next_index = next0;
  	      t->tx_fib_index = adj0->rewrite_header.sw_if_index;
  	    }
  
  	  /* 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_xcrw_node, static) = {
    .function = l2_xcrw_node_fn,
    .name = "l2-xcrw",
    .vector_size = sizeof (u32),
    .format_trace = format_l2_xcrw_trace,
    .type = VLIB_NODE_TYPE_INTERNAL,
  
    .n_errors = ARRAY_LEN(l2_xcrw_error_strings),
    .error_strings = l2_xcrw_error_strings,
  
    .n_next_nodes = L2_XCRW_N_NEXT,
  
    /* edit / add dispositions here */
    .next_nodes = {
          [L2_XCRW_NEXT_DROP] = "error-drop",
    },
  };
  /* *INDENT-ON* */
  
  VLIB_NODE_FUNCTION_MULTIARCH (l2_xcrw_node, l2_xcrw_node_fn)
       clib_error_t *l2_xcrw_init (vlib_main_t * vm)
  {
    l2_xcrw_main_t *mp = &l2_xcrw_main;
  
    mp->vlib_main = vm;
    mp->vnet_main = &vnet_main;
    mp->tunnel_index_by_l2_sw_if_index = hash_create (0, sizeof (uword));
  
    return 0;
  }
  
  VLIB_INIT_FUNCTION (l2_xcrw_init);
  
  static uword
  dummy_interface_tx (vlib_main_t * vm,
  		    vlib_node_runtime_t * node, vlib_frame_t * frame)
  {
    clib_warning ("you shouldn't be here, leaking buffers...");
    return frame->n_vectors;
  }
  
  static u8 *
  format_xcrw_name (u8 * s, va_list * args)
  {
    u32 dev_instance = va_arg (*args, u32);
    return format (s, "xcrw%d", dev_instance);
  }
  
  /* *INDENT-OFF* */
  VNET_DEVICE_CLASS (xcrw_device_class,static) = {
    .name = "Xcrw",
    .format_device_name = format_xcrw_name,
    .tx_function = dummy_interface_tx,
  };
  /* *INDENT-ON* */
  
  /* Create a sham tunnel interface and return its sw_if_index */
  static u32
  create_xcrw_interface (vlib_main_t * vm)
  {
    vnet_main_t *vnm = vnet_get_main ();
    static u32 instance;
    u8 address[6];
    u32 hw_if_index;
    vnet_hw_interface_t *hi;
    u32 sw_if_index;
  
    /* mac address doesn't really matter */
    clib_memset (address, 0, sizeof (address));
    address[2] = 0x12;
  
    /* can returns error iff phy != 0 */
    (void) ethernet_register_interface
      (vnm, xcrw_device_class.index, instance++, address, &hw_if_index,
       /* flag change */ 0);
  
    hi = vnet_get_hw_interface (vnm, hw_if_index);
    sw_if_index = hi->sw_if_index;
    vnet_sw_interface_set_flags (vnm, sw_if_index,
  			       VNET_SW_INTERFACE_FLAG_ADMIN_UP);
  
    /* Output to the sham tunnel invokes the encap node */
    hi->output_node_index = l2_xcrw_node.index;
  
    return sw_if_index;
  }
  
  int
  vnet_configure_l2_xcrw (vlib_main_t * vm, vnet_main_t * vnm,
  			u32 l2_sw_if_index, u32 tx_fib_index,
  			u8 * rewrite, u32 next_node_index, int is_add)
  {
    l2_xcrw_main_t *xcm = &l2_xcrw_main;
    l2_xcrw_adjacency_t *a;
    l2_xcrw_tunnel_t *t;
    uword *p;
  
    if (is_add)
      {
  
        pool_get (xcm->tunnels, t);
  
        /* No interface allocated? Do it. Otherwise, set admin up */
        if (t->tunnel_sw_if_index == 0)
  	t->tunnel_sw_if_index = create_xcrw_interface (vm);
        else
  	vnet_sw_interface_set_flags (vnm, t->tunnel_sw_if_index,
  				     VNET_SW_INTERFACE_FLAG_ADMIN_UP);
  
        t->l2_sw_if_index = l2_sw_if_index;
  
        vec_validate (xcm->adj_by_sw_if_index, t->l2_sw_if_index);
  
        a = vec_elt_at_index (xcm->adj_by_sw_if_index, t->l2_sw_if_index);
        clib_memset (a, 0, sizeof (*a));
  
        a->rewrite_header.sw_if_index = tx_fib_index;
  
        /*
         * Add or find a dynamic disposition for the successor node,
         * e.g. so we can ship pkts to mpls_post_rewrite...
         */
        a->rewrite_header.next_index =
  	vlib_node_add_next (vm, l2_xcrw_node.index, next_node_index);
  
        if (vec_len (rewrite))
  	vnet_rewrite_set_data (a[0], rewrite, vec_len (rewrite));
  
        set_int_l2_mode (vm, vnm, MODE_L2_XC, t->l2_sw_if_index, 0,
  		       L2_BD_PORT_TYPE_NORMAL, 0, t->tunnel_sw_if_index);
        hash_set (xcm->tunnel_index_by_l2_sw_if_index,
  		t->l2_sw_if_index, t - xcm->tunnels);
        return 0;
      }
    else
      {
        p = hash_get (xcm->tunnel_index_by_l2_sw_if_index, l2_sw_if_index);
        if (p == 0)
  	return VNET_API_ERROR_INVALID_SW_IF_INDEX;
  
        t = pool_elt_at_index (xcm->tunnels, p[0]);
  
        a = vec_elt_at_index (xcm->adj_by_sw_if_index, t->l2_sw_if_index);
        /* Reset adj to drop traffic */
        clib_memset (a, 0, sizeof (*a));
  
        set_int_l2_mode (vm, vnm, MODE_L3, t->l2_sw_if_index, 0,
  		       L2_BD_PORT_TYPE_NORMAL, 0, 0);
  
        vnet_sw_interface_set_flags (vnm, t->tunnel_sw_if_index, 0 /* down */ );
  
        hash_unset (xcm->tunnel_index_by_l2_sw_if_index, l2_sw_if_index);
        pool_put (xcm->tunnels, t);
      }
    return 0;
  }
  
  
  static clib_error_t *
  set_l2_xcrw_command_fn (vlib_main_t * vm,
  			unformat_input_t * input, vlib_cli_command_t * cmd)
  {
    unformat_input_t _line_input, *line_input = &_line_input;
    int is_add = 1;
    int is_ipv6 = 0;		/* for fib id -> fib index mapping */
    u32 tx_fib_id = ~0;
    u32 tx_fib_index = ~0;
    u32 next_node_index = ~0;
    u32 l2_sw_if_index;
    u8 *rw = 0;
    vnet_main_t *vnm = vnet_get_main ();
    int rv;
    clib_error_t *error = NULL;
  
  
    if (!unformat_user (input, unformat_line_input, line_input))
      return 0;
  
    if (!unformat (line_input, "%U",
  		 unformat_vnet_sw_interface, vnm, &l2_sw_if_index))
      {
        error = clib_error_return (0, "unknown input '%U'",
  				 format_unformat_error, line_input);
        goto done;
      }
  
    while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
      {
        if (unformat (line_input, "next %U",
  		    unformat_vlib_node, vm, &next_node_index))
  	;
        else if (unformat (line_input, "tx-fib-id %d", &tx_fib_id))
  	;
        else if (unformat (line_input, "del"))
  	is_add = 0;
        else if (unformat (line_input, "ipv6"))
  	is_ipv6 = 1;
        else if (unformat (line_input, "rw %U", unformat_hex_string, &rw));
        else
  	break;
      }
  
    if (next_node_index == ~0)
      {
        error = clib_error_return (0, "next node not specified");
        goto done;
      }
  
    if (tx_fib_id != ~0)
      {
        uword *p;
  
        if (is_ipv6)
  	p = hash_get (ip6_main.fib_index_by_table_id, tx_fib_id);
        else
  	p = hash_get (ip4_main.fib_index_by_table_id, tx_fib_id);
  
        if (p == 0)
  	{
  	  error =
  	    clib_error_return (0, "nonexistent tx_fib_id %d", tx_fib_id);
  	  goto done;
  	}
  
        tx_fib_index = p[0];
      }
  
    rv = vnet_configure_l2_xcrw (vm, vnm, l2_sw_if_index, tx_fib_index,
  			       rw, next_node_index, is_add);
  
    switch (rv)
      {
  
      case 0:
        break;
  
      case VNET_API_ERROR_INVALID_SW_IF_INDEX:
        error = clib_error_return (0, "%U not cross-connected",
  				 format_vnet_sw_if_index_name,
  				 vnm, l2_sw_if_index);
        goto done;
  
      default:
        error = clib_error_return (0, "vnet_configure_l2_xcrw returned %d", rv);
        goto done;
      }
  
  done:
    vec_free (rw);
    unformat_free (line_input);
  
    return error;
  }
  
  /*?
   * Add or delete a Layer 2 to Layer 3 rewrite cross-connect. This is
   * used to hook Layer 2 interface(s) up to the Layer 3 stack in
   * arbitrary ways. For example, cross-connect an L2 interface or
   * (future) bridge to an mpls-o-gre tunnel. Set up the L2 rewrite
   * string as shown in mpls_gre_rewrite, and use \"mpls-post-rewrite\"
   * to fix the GRE IP header checksum and length fields.
   *
   * @cliexpar
   * @todo This is incomplete. This needs a detailed description and a
   * practical example.
  ?*/
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (set_l2_xcrw_command, static) = {
    .path = "set interface l2 xcrw",
    .short_help =
    "set interface l2 xcrw <interface> next <node-name>\n"
    "    [del] [tx-fib-id <id>] [ipv6] rw <hex-bytes>",
    .function = set_l2_xcrw_command_fn,
  };
  /* *INDENT-ON* */
  
  static u8 *
  format_l2xcrw (u8 * s, va_list * args)
  {
    vnet_main_t *vnm = va_arg (*args, vnet_main_t *);
    l2_xcrw_tunnel_t *t = va_arg (*args, l2_xcrw_tunnel_t *);
    l2_xcrw_main_t *xcm = &l2_xcrw_main;
    vlib_main_t *vm = vlib_get_main ();
    l2_xcrw_adjacency_t *a;
    u8 *rewrite_string;
  
    if (t == 0)
      {
        s = format (s, "%-25s%s", "L2 interface", "Tunnel Details");
        return s;
      }
  
    s = format (s, "%-25U %U ",
  	      format_vnet_sw_if_index_name, vnm, t->l2_sw_if_index,
  	      format_vnet_sw_if_index_name, vnm, t->tunnel_sw_if_index);
  
    a = vec_elt_at_index (xcm->adj_by_sw_if_index, t->l2_sw_if_index);
  
    s = format (s, "next %U ",
  	      format_vlib_next_node_name, vm, l2_xcrw_node.index,
  	      a->rewrite_header.next_index);
  
    if (a->rewrite_header.sw_if_index != ~0)
      s = format (s, "tx fib index %d ", a->rewrite_header.sw_if_index);
  
    if (a->rewrite_header.data_bytes)
      {
        rewrite_string = (u8 *) (a + 1);
        rewrite_string -= a->rewrite_header.data_bytes;
        s = format (s, "rewrite data: %U ",
  		  format_hex_bytes, rewrite_string,
  		  a->rewrite_header.data_bytes);
      }
  
    s = format (s, "\n");
  
    return s;
  }
  
  
  static clib_error_t *
  show_l2xcrw_command_fn (vlib_main_t * vm,
  			unformat_input_t * input, vlib_cli_command_t * cmd)
  {
    vnet_main_t *vnm = vnet_get_main ();
    l2_xcrw_main_t *xcm = &l2_xcrw_main;
    l2_xcrw_tunnel_t *t;
  
    if (pool_elts (xcm->tunnels) == 0)
      {
        vlib_cli_output (vm, "No L2 / L3 rewrite cross-connects configured");
        return 0;
      }
  
    vlib_cli_output (vm, "%U", format_l2xcrw, 0, 0);
  
    /* *INDENT-OFF* */
    pool_foreach (t, xcm->tunnels,
    ({
      vlib_cli_output (vm, "%U", format_l2xcrw, vnm, t);
    }));
    /* *INDENT-ON* */
  
    return 0;
  }
  
  /*?
   * Display a Layer 2 to Layer 3 rewrite cross-connect. This is used to
   * hook Layer 2 interface(s) up to the Layer 3 stack in arbitrary ways.
   *
   * @todo This is incomplete. This needs a detailed description and a
   * practical example.
  ?*/
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (show_l2xcrw_command, static) = {
    .path = "show l2xcrw",
    .short_help = "show l2xcrw",
    .function = show_l2xcrw_command_fn,
  };
  /* *INDENT-ON* */
  
  /*
   * fd.io coding-style-patch-verification: ON
   *
   * Local Variables:
   * eval: (c-set-style "gnu")
   * End:
   */
  