src/vnet/l2/l2_patch.c - fdio/vpp - Gitiles

 /*
  * 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 <vlib/vlib.h>
 #include <vnet/vnet.h>
 #include <vnet/pg/pg.h>
 #include <vnet/ethernet/ethernet.h>
 #include <vnet/feature/feature.h>
 #include <vppinfra/error.h>

 typedef struct
 {
   /* vector of dispositions, indexed by rx_sw_if_index */
   u32 *tx_next_by_rx_sw_if_index;
   u32 *tx_sw_if_index_by_rx_sw_if_index;

   /* convenience variables */
   vlib_main_t *vlib_main;
   vnet_main_t *vnet_main;
 } l2_patch_main_t;

 typedef struct
 {
   u32 rx_sw_if_index;
   u32 tx_sw_if_index;
 } l2_patch_trace_t;

 /* packet trace format function */
 static u8 *
 format_l2_patch_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_patch_trace_t *t = va_arg (*args, l2_patch_trace_t *);

   s = format (s, "L2_PATCH: rx %d tx %d", t->rx_sw_if_index,
 	      t->tx_sw_if_index);
   return s;
 }

 l2_patch_main_t l2_patch_main;

 static vlib_node_registration_t l2_patch_node;

 #define foreach_l2_patch_error			\
 _(PATCHED, "L2 patch packets")			\
 _(DROPPED, "L2 patch misconfigured drops")

 typedef enum
 {
 #define _(sym,str) L2_PATCH_ERROR_##sym,
   foreach_l2_patch_error
 #undef _
     L2_PATCH_N_ERROR,
 } l2_patch_error_t;

 static char *l2_patch_error_strings[] = {
 #define _(sym,string) string,
   foreach_l2_patch_error
 #undef _
 };

 typedef enum
 {
   L2_PATCH_NEXT_DROP,
   L2_PATCH_N_NEXT,
 } l2_patch_next_t;

 static_always_inline void
 l2_patch_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 		l2_patch_main_t * l2pm, vlib_buffer_t * b, u32 sw_if_index)
 {
   l2_patch_trace_t *t;

   if ((b->flags & VLIB_BUFFER_IS_TRACED) == 0)
     return;

   t = vlib_add_trace (vm, node, b, sizeof (*t));
   t->rx_sw_if_index = sw_if_index;
   t->tx_sw_if_index = l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index];
 }

 static_always_inline void
 l2_patch_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 		 l2_patch_main_t * l2pm, vlib_buffer_t ** b, u16 * next,
 		 u32 n_left, int do_trace)
 {
   u32 sw_if_index[4];

   while (n_left >= 4)
     {
       /* Prefetch next iteration. */
       if (n_left >= 8)
 	{
 	  vlib_buffer_t **p = b + 4;
 	  vlib_prefetch_buffer_header (p[0], LOAD);
 	  vlib_prefetch_buffer_header (p[1], LOAD);
 	  vlib_prefetch_buffer_header (p[2], LOAD);
 	  vlib_prefetch_buffer_header (p[3], LOAD);
 	}

       sw_if_index[0] = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
       sw_if_index[1] = vnet_buffer (b[1])->sw_if_index[VLIB_RX];
       sw_if_index[2] = vnet_buffer (b[2])->sw_if_index[VLIB_RX];
       sw_if_index[3] = vnet_buffer (b[3])->sw_if_index[VLIB_RX];

       ASSERT (l2pm->tx_next_by_rx_sw_if_index[sw_if_index[0]] != ~0);
       ASSERT (l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[0]] != ~0);
       ASSERT (l2pm->tx_next_by_rx_sw_if_index[sw_if_index[1]] != ~0);
       ASSERT (l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[1]] != ~0);
       ASSERT (l2pm->tx_next_by_rx_sw_if_index[sw_if_index[2]] != ~0);
       ASSERT (l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[2]] != ~0);
       ASSERT (l2pm->tx_next_by_rx_sw_if_index[sw_if_index[3]] != ~0);
       ASSERT (l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[3]] != ~0);

       next[0] = l2pm->tx_next_by_rx_sw_if_index[sw_if_index[0]];
       next[1] = l2pm->tx_next_by_rx_sw_if_index[sw_if_index[1]];
       next[2] = l2pm->tx_next_by_rx_sw_if_index[sw_if_index[2]];
       next[3] = l2pm->tx_next_by_rx_sw_if_index[sw_if_index[3]];

       vnet_buffer (b[0])->sw_if_index[VLIB_TX] =
 	l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[0]];
       vnet_buffer (b[1])->sw_if_index[VLIB_TX] =
 	l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[1]];
       vnet_buffer (b[2])->sw_if_index[VLIB_TX] =
 	l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[2]];
       vnet_buffer (b[3])->sw_if_index[VLIB_TX] =
 	l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[3]];

       if (do_trace)
 	{
 	  l2_patch_trace (vm, node, l2pm, b[0], sw_if_index[0]);
 	  l2_patch_trace (vm, node, l2pm, b[1], sw_if_index[1]);
 	  l2_patch_trace (vm, node, l2pm, b[2], sw_if_index[2]);
 	  l2_patch_trace (vm, node, l2pm, b[3], sw_if_index[3]);
 	}

       /* next */
       next += 4;
       b += 4;
       n_left -= 4;
     }

   while (n_left)
     {
       sw_if_index[0] = vnet_buffer (b[0])->sw_if_index[VLIB_RX];

       ASSERT (l2pm->tx_next_by_rx_sw_if_index[sw_if_index[0]] != ~0);
       ASSERT (l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[0]] != ~0);

       next[0] = l2pm->tx_next_by_rx_sw_if_index[sw_if_index[0]];

       vnet_buffer (b[0])->sw_if_index[VLIB_TX] =
 	l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[0]];

       if (do_trace)
 	l2_patch_trace (vm, node, l2pm, b[0], sw_if_index[0]);

       /* next */
       next += 1;
       b += 1;
       n_left -= 1;
     }
 }

 VLIB_NODE_FN (l2_patch_node) (vlib_main_t * vm,
 			      vlib_node_runtime_t * node,
 			      vlib_frame_t * frame)
 {
   u32 *from;
   l2_patch_main_t *l2pm = &l2_patch_main;
   vlib_node_t *n = vlib_get_node (vm, l2_patch_node.index);
   u32 node_counter_base_index = n->error_heap_index;
   vlib_error_main_t *em = &vm->error_main;
   vlib_buffer_t *bufs[VLIB_FRAME_SIZE];
   u16 nexts[VLIB_FRAME_SIZE];

   from = vlib_frame_vector_args (frame);

   vlib_get_buffers (vm, from, bufs, frame->n_vectors);

   if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
     l2_patch_inline (vm, node, l2pm, bufs, nexts, frame->n_vectors, 1);
   else
     l2_patch_inline (vm, node, l2pm, bufs, nexts, frame->n_vectors, 0);

   vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);

   em->counters[node_counter_base_index + L2_PATCH_ERROR_PATCHED] +=
     frame->n_vectors;

   return frame->n_vectors;
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (l2_patch_node, static) = {
   .name = "l2-patch",
   .vector_size = sizeof (u32),
   .format_trace = format_l2_patch_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,

   .n_errors = ARRAY_LEN(l2_patch_error_strings),
   .error_strings = l2_patch_error_strings,

   .n_next_nodes = L2_PATCH_N_NEXT,

   /* edit / add dispositions here */
   .next_nodes = {
         [L2_PATCH_NEXT_DROP] = "error-drop",
   },
 };
 /* *INDENT-ON* */

 extern int
 vnet_l2_patch_add_del (u32 rx_sw_if_index, u32 tx_sw_if_index, int is_add);
 #ifndef CLIB_MARCH_VARIANT
 int
 vnet_l2_patch_add_del (u32 rx_sw_if_index, u32 tx_sw_if_index, int is_add)
 {
   l2_patch_main_t *l2pm = &l2_patch_main;
   vnet_hw_interface_t *rxhi, *txhi;
   u32 tx_next_index;

   /*
    * We assume that the API msg handler has used 2x VALIDATE_SW_IF_INDEX
    * macros...
    */

   rxhi = vnet_get_sup_hw_interface (l2pm->vnet_main, rx_sw_if_index);

   /* Make sure caller didn't pass a vlan subif, etc. */
   if (rxhi->sw_if_index != rx_sw_if_index)
     return VNET_API_ERROR_INVALID_SW_IF_INDEX;

   txhi = vnet_get_sup_hw_interface (l2pm->vnet_main, tx_sw_if_index);
   if (txhi->sw_if_index != tx_sw_if_index)
     return VNET_API_ERROR_INVALID_SW_IF_INDEX_2;

   if (is_add)
     {
       tx_next_index = vlib_node_add_next (l2pm->vlib_main,
 					  l2_patch_node.index,
 					  txhi->output_node_index);

       vec_validate_init_empty (l2pm->tx_next_by_rx_sw_if_index,
 			       rx_sw_if_index, ~0);

       l2pm->tx_next_by_rx_sw_if_index[rx_sw_if_index] = tx_next_index;
       vec_validate_init_empty (l2pm->tx_sw_if_index_by_rx_sw_if_index,
 			       rx_sw_if_index, ~0);
       l2pm->tx_sw_if_index_by_rx_sw_if_index[rx_sw_if_index]
 	= txhi->sw_if_index;

       ethernet_set_flags (l2pm->vnet_main, rxhi->hw_if_index,
 			  ETHERNET_INTERFACE_FLAG_ACCEPT_ALL);

       vnet_feature_enable_disable ("device-input", "l2-patch",
 				   rxhi->hw_if_index, 1, 0, 0);
     }
   else
     {
       ethernet_set_flags (l2pm->vnet_main, rxhi->hw_if_index,
 			  0 /* disable promiscuous mode */ );

       vnet_feature_enable_disable ("device-input", "l2-patch",
 				   rxhi->hw_if_index, 0, 0, 0);
       if (vec_len (l2pm->tx_next_by_rx_sw_if_index) > rx_sw_if_index)
 	{
 	  l2pm->tx_next_by_rx_sw_if_index[rx_sw_if_index] = ~0;
 	  l2pm->tx_sw_if_index_by_rx_sw_if_index[rx_sw_if_index] = ~0;
 	}
     }

   return 0;
 }
 #endif

 static clib_error_t *
 test_patch_command_fn (vlib_main_t * vm,
 		       unformat_input_t * input, vlib_cli_command_t * cmd)
 {
   l2_patch_main_t *l2pm = &l2_patch_main;
   unformat_input_t _line_input, *line_input = &_line_input;
   u32 rx_sw_if_index, tx_sw_if_index;
   int rv;
   int rx_set = 0;
   int tx_set = 0;
   int is_add = 1;
   clib_error_t *error = NULL;

   /* Get a line of input. */
   if (!unformat_user (input, unformat_line_input, line_input))
     return 0;

   while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
     {
       if (unformat (line_input, "rx %U", unformat_vnet_sw_interface,
 		    l2pm->vnet_main, &rx_sw_if_index))
 	rx_set = 1;
       else if (unformat (line_input, "tx %U", unformat_vnet_sw_interface,
 			 l2pm->vnet_main, &tx_sw_if_index))
 	tx_set = 1;
       else if (unformat (line_input, "del"))
 	is_add = 0;
       else
 	break;
     }

   if (rx_set == 0)
     {
       error = clib_error_return (0, "rx interface not set");
       goto done;
     }

   if (tx_set == 0)
     {
       error = clib_error_return (0, "tx interface not set");
       goto done;
     }

   rv = vnet_l2_patch_add_del (rx_sw_if_index, tx_sw_if_index, is_add);

   switch (rv)
     {
     case 0:
       break;

     case VNET_API_ERROR_INVALID_SW_IF_INDEX:
       error = clib_error_return (0, "rx interface not a physical port");
       goto done;

     case VNET_API_ERROR_INVALID_SW_IF_INDEX_2:
       error = clib_error_return (0, "tx interface not a physical port");
       goto done;

     default:
       error = clib_error_return
 	(0, "WARNING: vnet_l2_patch_add_del returned %d", rv);
       goto done;
     }


 done:
   unformat_free (line_input);

   return error;
 }

 /*?
  * Create or delete a Layer 2 patch.
  *
  * @cliexpar
  * @cliexstart{test l2patch rx <intfc> tx <intfc> [del]}
  * @cliexend
  * @todo This is incomplete. This needs a detailed description and a
  * practical example.
 ?*/
 /* *INDENT-OFF* */
 VLIB_CLI_COMMAND (test_patch_command, static) = {
     .path = "test l2patch",
     .short_help = "test l2patch rx <intfc> tx <intfc> [del]",
     .function = test_patch_command_fn,
 };
 /* *INDENT-ON* */

 /** Display the contents of the l2patch table. */
 static clib_error_t *
 show_l2patch (vlib_main_t * vm,
 	      unformat_input_t * input, vlib_cli_command_t * cmd)
 {
   l2_patch_main_t *l2pm = &l2_patch_main;
   u32 rx_sw_if_index;
   u32 no_entries = 1;

   ASSERT (vec_len (l2pm->tx_next_by_rx_sw_if_index) ==
 	  vec_len (l2pm->tx_sw_if_index_by_rx_sw_if_index));

   for (rx_sw_if_index = 0;
        rx_sw_if_index < vec_len (l2pm->tx_sw_if_index_by_rx_sw_if_index);
        rx_sw_if_index++)
     {
       u32 tx_sw_if_index =
 	l2pm->tx_sw_if_index_by_rx_sw_if_index[rx_sw_if_index];
       if (tx_sw_if_index != ~0)
 	{
 	  no_entries = 0;
 	  vlib_cli_output (vm, "%26U -> %U",
 			   format_vnet_sw_if_index_name,
 			   l2pm->vnet_main, rx_sw_if_index,
 			   format_vnet_sw_if_index_name,
 			   l2pm->vnet_main, tx_sw_if_index);
 	}
     }

   if (no_entries)
     vlib_cli_output (vm, "no l2patch entries");

   return 0;
 }

 /*?
  * Show Layer 2 patch entries.
  *
  * @cliexpar
  * @cliexstart{show l2patch}
  * @cliexend
  * @todo This is incomplete. This needs a detailed description and a
  * practical example.
 ?*/
 /* *INDENT-OFF* */
 VLIB_CLI_COMMAND (show_l2patch_cli, static) = {
   .path = "show l2patch",
   .short_help = "Show l2 interface cross-connect entries",
   .function = show_l2patch,
 };
 /* *INDENT-ON* */

 static clib_error_t *
 l2_patch_init (vlib_main_t * vm)
 {
   l2_patch_main_t *mp = &l2_patch_main;

   mp->vlib_main = vm;
   mp->vnet_main = vnet_get_main ();

   return 0;
 }

 VLIB_INIT_FUNCTION (l2_patch_init);

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* 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 <vlib/vlib.h>
	#include <vnet/vnet.h>
	#include <vnet/pg/pg.h>
	#include <vnet/ethernet/ethernet.h>
	#include <vnet/feature/feature.h>
	#include <vppinfra/error.h>

	typedef struct
	{
	/* vector of dispositions, indexed by rx_sw_if_index */
	u32 *tx_next_by_rx_sw_if_index;
	u32 *tx_sw_if_index_by_rx_sw_if_index;

	/* convenience variables */
	vlib_main_t *vlib_main;
	vnet_main_t *vnet_main;
	} l2_patch_main_t;

	typedef struct
	{
	u32 rx_sw_if_index;
	u32 tx_sw_if_index;
	} l2_patch_trace_t;

	/* packet trace format function */
	static u8 *
	format_l2_patch_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_patch_trace_t t = va_arg (args, l2_patch_trace_t *);

	s = format (s, "L2_PATCH: rx %d tx %d", t->rx_sw_if_index,
	t->tx_sw_if_index);
	return s;
	}

	l2_patch_main_t l2_patch_main;

	static vlib_node_registration_t l2_patch_node;

	#define foreach_l2_patch_error \
	_(PATCHED, "L2 patch packets") \
	_(DROPPED, "L2 patch misconfigured drops")

	typedef enum
	{
	#define _(sym,str) L2_PATCH_ERROR_##sym,
	foreach_l2_patch_error
	#undef _
	L2_PATCH_N_ERROR,
	} l2_patch_error_t;

	static char *l2_patch_error_strings[] = {
	#define _(sym,string) string,
	foreach_l2_patch_error
	#undef _
	};

	typedef enum
	{
	L2_PATCH_NEXT_DROP,
	L2_PATCH_N_NEXT,
	} l2_patch_next_t;

	static_always_inline void
	l2_patch_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
	l2_patch_main_t * l2pm, vlib_buffer_t * b, u32 sw_if_index)
	{
	l2_patch_trace_t *t;

	if ((b->flags & VLIB_BUFFER_IS_TRACED) == 0)
	return;

	t = vlib_add_trace (vm, node, b, sizeof (*t));
	t->rx_sw_if_index = sw_if_index;
	t->tx_sw_if_index = l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index];
	}

	static_always_inline void
	l2_patch_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
	l2_patch_main_t * l2pm, vlib_buffer_t ** b, u16 * next,
	u32 n_left, int do_trace)
	{
	u32 sw_if_index[4];

	while (n_left >= 4)
	{
	/* Prefetch next iteration. */
	if (n_left >= 8)
	{
	vlib_buffer_t **p = b + 4;
	vlib_prefetch_buffer_header (p[0], LOAD);
	vlib_prefetch_buffer_header (p[1], LOAD);
	vlib_prefetch_buffer_header (p[2], LOAD);
	vlib_prefetch_buffer_header (p[3], LOAD);
	}

	sw_if_index[0] = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
	sw_if_index[1] = vnet_buffer (b[1])->sw_if_index[VLIB_RX];
	sw_if_index[2] = vnet_buffer (b[2])->sw_if_index[VLIB_RX];
	sw_if_index[3] = vnet_buffer (b[3])->sw_if_index[VLIB_RX];

	ASSERT (l2pm->tx_next_by_rx_sw_if_index[sw_if_index[0]] != ~0);
	ASSERT (l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[0]] != ~0);
	ASSERT (l2pm->tx_next_by_rx_sw_if_index[sw_if_index[1]] != ~0);
	ASSERT (l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[1]] != ~0);
	ASSERT (l2pm->tx_next_by_rx_sw_if_index[sw_if_index[2]] != ~0);
	ASSERT (l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[2]] != ~0);
	ASSERT (l2pm->tx_next_by_rx_sw_if_index[sw_if_index[3]] != ~0);
	ASSERT (l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[3]] != ~0);

	next[0] = l2pm->tx_next_by_rx_sw_if_index[sw_if_index[0]];
	next[1] = l2pm->tx_next_by_rx_sw_if_index[sw_if_index[1]];
	next[2] = l2pm->tx_next_by_rx_sw_if_index[sw_if_index[2]];
	next[3] = l2pm->tx_next_by_rx_sw_if_index[sw_if_index[3]];

	vnet_buffer (b[0])->sw_if_index[VLIB_TX] =
	l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[0]];
	vnet_buffer (b[1])->sw_if_index[VLIB_TX] =
	l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[1]];
	vnet_buffer (b[2])->sw_if_index[VLIB_TX] =
	l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[2]];
	vnet_buffer (b[3])->sw_if_index[VLIB_TX] =
	l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[3]];

	if (do_trace)
	{
	l2_patch_trace (vm, node, l2pm, b[0], sw_if_index[0]);
	l2_patch_trace (vm, node, l2pm, b[1], sw_if_index[1]);
	l2_patch_trace (vm, node, l2pm, b[2], sw_if_index[2]);
	l2_patch_trace (vm, node, l2pm, b[3], sw_if_index[3]);
	}

	/* next */
	next += 4;
	b += 4;
	n_left -= 4;
	}

	while (n_left)
	{
	sw_if_index[0] = vnet_buffer (b[0])->sw_if_index[VLIB_RX];

	ASSERT (l2pm->tx_next_by_rx_sw_if_index[sw_if_index[0]] != ~0);
	ASSERT (l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[0]] != ~0);

	next[0] = l2pm->tx_next_by_rx_sw_if_index[sw_if_index[0]];

	vnet_buffer (b[0])->sw_if_index[VLIB_TX] =
	l2pm->tx_sw_if_index_by_rx_sw_if_index[sw_if_index[0]];

	if (do_trace)
	l2_patch_trace (vm, node, l2pm, b[0], sw_if_index[0]);

	/* next */
	next += 1;
	b += 1;
	n_left -= 1;
	}
	}

	VLIB_NODE_FN (l2_patch_node) (vlib_main_t * vm,
	vlib_node_runtime_t * node,
	vlib_frame_t * frame)
	{
	u32 *from;
	l2_patch_main_t *l2pm = &l2_patch_main;
	vlib_node_t *n = vlib_get_node (vm, l2_patch_node.index);
	u32 node_counter_base_index = n->error_heap_index;
	vlib_error_main_t *em = &vm->error_main;
	vlib_buffer_t *bufs[VLIB_FRAME_SIZE];
	u16 nexts[VLIB_FRAME_SIZE];

	from = vlib_frame_vector_args (frame);

	vlib_get_buffers (vm, from, bufs, frame->n_vectors);

	if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
	l2_patch_inline (vm, node, l2pm, bufs, nexts, frame->n_vectors, 1);
	else
	l2_patch_inline (vm, node, l2pm, bufs, nexts, frame->n_vectors, 0);

	vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);

	em->counters[node_counter_base_index + L2_PATCH_ERROR_PATCHED] +=
	frame->n_vectors;

	return frame->n_vectors;
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (l2_patch_node, static) = {
	.name = "l2-patch",
	.vector_size = sizeof (u32),
	.format_trace = format_l2_patch_trace,
	.type = VLIB_NODE_TYPE_INTERNAL,

	.n_errors = ARRAY_LEN(l2_patch_error_strings),
	.error_strings = l2_patch_error_strings,

	.n_next_nodes = L2_PATCH_N_NEXT,

	/* edit / add dispositions here */
	.next_nodes = {
	[L2_PATCH_NEXT_DROP] = "error-drop",
	},
	};
	/* INDENT-ON */

	extern int
	vnet_l2_patch_add_del (u32 rx_sw_if_index, u32 tx_sw_if_index, int is_add);
	#ifndef CLIB_MARCH_VARIANT
	int
	vnet_l2_patch_add_del (u32 rx_sw_if_index, u32 tx_sw_if_index, int is_add)
	{
	l2_patch_main_t *l2pm = &l2_patch_main;
	vnet_hw_interface_t rxhi, txhi;
	u32 tx_next_index;

	/*
	* We assume that the API msg handler has used 2x VALIDATE_SW_IF_INDEX
	* macros...
	*/

	rxhi = vnet_get_sup_hw_interface (l2pm->vnet_main, rx_sw_if_index);

	/* Make sure caller didn't pass a vlan subif, etc. */
	if (rxhi->sw_if_index != rx_sw_if_index)
	return VNET_API_ERROR_INVALID_SW_IF_INDEX;

	txhi = vnet_get_sup_hw_interface (l2pm->vnet_main, tx_sw_if_index);
	if (txhi->sw_if_index != tx_sw_if_index)
	return VNET_API_ERROR_INVALID_SW_IF_INDEX_2;

	if (is_add)
	{
	tx_next_index = vlib_node_add_next (l2pm->vlib_main,
	l2_patch_node.index,
	txhi->output_node_index);

	vec_validate_init_empty (l2pm->tx_next_by_rx_sw_if_index,
	rx_sw_if_index, ~0);

	l2pm->tx_next_by_rx_sw_if_index[rx_sw_if_index] = tx_next_index;
	vec_validate_init_empty (l2pm->tx_sw_if_index_by_rx_sw_if_index,
	rx_sw_if_index, ~0);
	l2pm->tx_sw_if_index_by_rx_sw_if_index[rx_sw_if_index]
	= txhi->sw_if_index;

	ethernet_set_flags (l2pm->vnet_main, rxhi->hw_if_index,
	ETHERNET_INTERFACE_FLAG_ACCEPT_ALL);

	vnet_feature_enable_disable ("device-input", "l2-patch",
	rxhi->hw_if_index, 1, 0, 0);
	}
	else
	{
	ethernet_set_flags (l2pm->vnet_main, rxhi->hw_if_index,
	0 /* disable promiscuous mode */ );

	vnet_feature_enable_disable ("device-input", "l2-patch",
	rxhi->hw_if_index, 0, 0, 0);
	if (vec_len (l2pm->tx_next_by_rx_sw_if_index) > rx_sw_if_index)
	{
	l2pm->tx_next_by_rx_sw_if_index[rx_sw_if_index] = ~0;
	l2pm->tx_sw_if_index_by_rx_sw_if_index[rx_sw_if_index] = ~0;
	}
	}

	return 0;
	}
	#endif

	static clib_error_t *
	test_patch_command_fn (vlib_main_t * vm,
	unformat_input_t * input, vlib_cli_command_t * cmd)
	{
	l2_patch_main_t *l2pm = &l2_patch_main;
	unformat_input_t _line_input, *line_input = &_line_input;
	u32 rx_sw_if_index, tx_sw_if_index;
	int rv;
	int rx_set = 0;
	int tx_set = 0;
	int is_add = 1;
	clib_error_t *error = NULL;

	/* Get a line of input. */
	if (!unformat_user (input, unformat_line_input, line_input))
	return 0;

	while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
	{
	if (unformat (line_input, "rx %U", unformat_vnet_sw_interface,
	l2pm->vnet_main, &rx_sw_if_index))
	rx_set = 1;
	else if (unformat (line_input, "tx %U", unformat_vnet_sw_interface,
	l2pm->vnet_main, &tx_sw_if_index))
	tx_set = 1;
	else if (unformat (line_input, "del"))
	is_add = 0;
	else
	break;
	}

	if (rx_set == 0)
	{
	error = clib_error_return (0, "rx interface not set");
	goto done;
	}

	if (tx_set == 0)
	{
	error = clib_error_return (0, "tx interface not set");
	goto done;
	}

	rv = vnet_l2_patch_add_del (rx_sw_if_index, tx_sw_if_index, is_add);

	switch (rv)
	{
	case 0:
	break;

	case VNET_API_ERROR_INVALID_SW_IF_INDEX:
	error = clib_error_return (0, "rx interface not a physical port");
	goto done;

	case VNET_API_ERROR_INVALID_SW_IF_INDEX_2:
	error = clib_error_return (0, "tx interface not a physical port");
	goto done;

	default:
	error = clib_error_return
	(0, "WARNING: vnet_l2_patch_add_del returned %d", rv);
	goto done;
	}


	done:
	unformat_free (line_input);

	return error;
	}

	/*?
	* Create or delete a Layer 2 patch.
	*
	* @cliexpar
	* @cliexstart{test l2patch rx <intfc> tx <intfc> [del]}
	* @cliexend
	* @todo This is incomplete. This needs a detailed description and a
	* practical example.
	?*/
	/* INDENT-OFF */
	VLIB_CLI_COMMAND (test_patch_command, static) = {
	.path = "test l2patch",
	.short_help = "test l2patch rx <intfc> tx <intfc> [del]",
	.function = test_patch_command_fn,
	};
	/* INDENT-ON */

	/** Display the contents of the l2patch table. */
	static clib_error_t *
	show_l2patch (vlib_main_t * vm,
	unformat_input_t * input, vlib_cli_command_t * cmd)
	{
	l2_patch_main_t *l2pm = &l2_patch_main;
	u32 rx_sw_if_index;
	u32 no_entries = 1;

	ASSERT (vec_len (l2pm->tx_next_by_rx_sw_if_index) ==
	vec_len (l2pm->tx_sw_if_index_by_rx_sw_if_index));

	for (rx_sw_if_index = 0;
	rx_sw_if_index < vec_len (l2pm->tx_sw_if_index_by_rx_sw_if_index);
	rx_sw_if_index++)
	{
	u32 tx_sw_if_index =
	l2pm->tx_sw_if_index_by_rx_sw_if_index[rx_sw_if_index];
	if (tx_sw_if_index != ~0)
	{
	no_entries = 0;
	vlib_cli_output (vm, "%26U -> %U",
	format_vnet_sw_if_index_name,
	l2pm->vnet_main, rx_sw_if_index,
	format_vnet_sw_if_index_name,
	l2pm->vnet_main, tx_sw_if_index);
	}
	}

	if (no_entries)
	vlib_cli_output (vm, "no l2patch entries");

	return 0;
	}

	/*?
	* Show Layer 2 patch entries.
	*
	* @cliexpar
	* @cliexstart{show l2patch}
	* @cliexend
	* @todo This is incomplete. This needs a detailed description and a
	* practical example.
	?*/
	/* INDENT-OFF */
	VLIB_CLI_COMMAND (show_l2patch_cli, static) = {
	.path = "show l2patch",
	.short_help = "Show l2 interface cross-connect entries",
	.function = show_l2patch,
	};
	/* INDENT-ON */

	static clib_error_t *
	l2_patch_init (vlib_main_t * vm)
	{
	l2_patch_main_t *mp = &l2_patch_main;

	mp->vlib_main = vm;
	mp->vnet_main = vnet_get_main ();

	return 0;
	}

	VLIB_INIT_FUNCTION (l2_patch_init);

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/