Reorganize source tree to use single autotools instance

Change-Id: I7b51f88292e057c6443b12224486f2d0c9f8ae23
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 932 insertions, 0 deletions

diff --git a/src/vnet/srp/node.c b/src/vnet/srp/node.c
new file mode 100644
index 00000000000..897be254624
--- /dev/null
+++ b/src/vnet/srp/node.c
@@ -0,0 +1,932 @@
+/*
+ * 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.
+ */
+/*
+ * node.c: srp packet processing
+ *
+ * Copyright (c) 2011 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/ip/ip_packet.h>	/* for ip_csum_fold */
+#include <vnet/srp/srp.h>
+
+typedef struct {
+  u8 packet_data[32];
+} srp_input_trace_t;
+
+static u8 * format_srp_input_trace (u8 * s, va_list * va)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
+  srp_input_trace_t * t = va_arg (*va, srp_input_trace_t *);
+
+  s = format (s, "%U", format_srp_header, t->packet_data);
+
+  return s;
+}
+
+typedef enum {
+  SRP_INPUT_NEXT_ERROR,
+  SRP_INPUT_NEXT_ETHERNET_INPUT,
+  SRP_INPUT_NEXT_CONTROL,
+  SRP_INPUT_N_NEXT,
+} srp_input_next_t;
+
+typedef struct {
+  u8 next_index;
+  u8 buffer_advance;
+  u16 error;
+} srp_input_disposition_t;
+
+static srp_input_disposition_t srp_input_disposition_by_mode[8] = {
+  [SRP_MODE_reserved0] = {
+    .next_index = SRP_INPUT_NEXT_ERROR,
+    .error = SRP_ERROR_UNKNOWN_MODE,
+  },
+  [SRP_MODE_reserved1] = {
+    .next_index = SRP_INPUT_NEXT_ERROR,
+    .error = SRP_ERROR_UNKNOWN_MODE,
+  },
+  [SRP_MODE_reserved2] = {
+    .next_index = SRP_INPUT_NEXT_ERROR,
+    .error = SRP_ERROR_UNKNOWN_MODE,
+  },
+  [SRP_MODE_reserved3] = {
+    .next_index = SRP_INPUT_NEXT_ERROR,
+    .error = SRP_ERROR_UNKNOWN_MODE,
+  },
+  [SRP_MODE_keep_alive] = {
+    .next_index = SRP_INPUT_NEXT_ERROR,
+    .error = SRP_ERROR_KEEP_ALIVE_DROPPED,
+  },
+  [SRP_MODE_data] = {
+    .next_index = SRP_INPUT_NEXT_ETHERNET_INPUT,
+    .buffer_advance = sizeof (srp_header_t),
+  },
+  [SRP_MODE_control_pass_to_host] = {
+    .next_index = SRP_INPUT_NEXT_CONTROL,
+  },
+  [SRP_MODE_control_locally_buffered_for_host] = {
+    .next_index = SRP_INPUT_NEXT_CONTROL,
+  },
+};
+
+static uword
+srp_input (vlib_main_t * vm,
+	   vlib_node_runtime_t * node,
+	   vlib_frame_t * from_frame)
+{
+  vnet_main_t * vnm = vnet_get_main();
+  srp_main_t * sm = &srp_main;
+  u32 n_left_from, next_index, * from, * to_next;
+
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+
+  if (node->flags & VLIB_NODE_FLAG_TRACE)
+    vlib_trace_frame_buffers_only (vm, node,
+				   from,
+				   n_left_from,
+				   sizeof (from[0]),
+				   sizeof (srp_input_trace_t));
+
+  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, sw_if_index0, sw_if_index1;
+	  vlib_buffer_t * b0, * b1;
+	  u8 next0, next1, error0, error1;
+	  srp_header_t * s0, * s1;
+	  srp_input_disposition_t * d0, * d1;
+	  vnet_hw_interface_t * hi0, * hi1;
+	  srp_interface_t * si0, * si1;
+
+	  /* Prefetch next iteration. */
+	  {
+	    vlib_buffer_t * b2, * b3;
+
+	    b2 = vlib_get_buffer (vm, from[2]);
+	    b3 = vlib_get_buffer (vm, from[3]);
+
+	    vlib_prefetch_buffer_header (b2, LOAD);
+	    vlib_prefetch_buffer_header (b3, LOAD);
+
+	    CLIB_PREFETCH (b2->data, sizeof (srp_header_t), LOAD);
+	    CLIB_PREFETCH (b3->data, sizeof (srp_header_t), LOAD);
+	  }
+
+	  bi0 = from[0];
+	  bi1 = from[1];
+	  to_next[0] = bi0;
+	  to_next[1] = bi1;
+	  from += 2;
+	  to_next += 2;
+	  n_left_to_next -= 2;
+	  n_left_from -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  s0 = (void *) (b0->data + b0->current_data);
+	  s1 = (void *) (b1->data + b1->current_data);
+
+	  /* Data packets are always assigned to side A (outer ring) interface. */
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	  sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
+
+	  hi0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
+	  hi1 = vnet_get_sup_hw_interface (vnm, sw_if_index1);
+
+	  si0 = pool_elt_at_index (sm->interface_pool, hi0->hw_instance);
+	  si1 = pool_elt_at_index (sm->interface_pool, hi1->hw_instance);
+
+	  sw_if_index0 = (s0->mode == SRP_MODE_data
+			  ? si0->rings[SRP_RING_OUTER].sw_if_index
+			  : sw_if_index0);
+	  sw_if_index1 = (s1->mode == SRP_MODE_data
+			  ? si1->rings[SRP_RING_OUTER].sw_if_index
+			  : sw_if_index1);
+	    
+	  vnet_buffer (b0)->sw_if_index[VLIB_RX] = sw_if_index0;
+	  vnet_buffer (b1)->sw_if_index[VLIB_RX] = sw_if_index1;
+
+	  d0 = srp_input_disposition_by_mode + s0->mode;
+	  d1 = srp_input_disposition_by_mode + s1->mode;
+
+	  next0 = d0->next_index;
+	  next1 = d1->next_index;
+
+	  error0 = d0->error;
+	  error1 = d1->error;
+
+	  vlib_buffer_advance (b0, d0->buffer_advance);
+	  vlib_buffer_advance (b1, d1->buffer_advance);
+
+	  b0->error = node->errors[error0];
+	  b1->error = node->errors[error1];
+
+	  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, sw_if_index0;
+	  vlib_buffer_t * b0;
+	  u8 next0, error0;
+	  srp_header_t * s0;
+	  srp_input_disposition_t * d0;
+	  srp_interface_t * si0;
+	  vnet_hw_interface_t * hi0;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_to_next -= 1;
+	  n_left_from -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+	  s0 = (void *) (b0->data + b0->current_data);
+
+	  /* Data packets are always assigned to side A (outer ring) interface. */
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+
+	  hi0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
+
+	  si0 = pool_elt_at_index (sm->interface_pool, hi0->hw_instance);
+
+	  sw_if_index0 = (s0->mode == SRP_MODE_data
+			  ? si0->rings[SRP_RING_OUTER].sw_if_index
+			  : sw_if_index0);
+	    
+	  vnet_buffer (b0)->sw_if_index[VLIB_RX] = sw_if_index0;
+
+	  d0 = srp_input_disposition_by_mode + s0->mode;
+
+	  next0 = d0->next_index;
+
+	  error0 = d0->error;
+
+	  vlib_buffer_advance (b0, d0->buffer_advance);
+
+	  b0->error = node->errors[error0];
+
+	  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 from_frame->n_vectors;
+}
+
+static char * srp_error_strings[] = {
+#define _(f,s) s,
+  foreach_srp_error
+#undef _
+};
+
+static vlib_node_registration_t srp_input_node = {
+  .function = srp_input,
+  .name = "srp-input",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_errors = SRP_N_ERROR,
+  .error_strings = srp_error_strings,
+
+  .n_next_nodes = SRP_INPUT_N_NEXT,
+  .next_nodes = {
+    [SRP_INPUT_NEXT_ERROR] = "error-drop",
+    [SRP_INPUT_NEXT_ETHERNET_INPUT] = "ethernet-input",
+    [SRP_INPUT_NEXT_CONTROL] = "srp-control",
+  },
+
+  .format_buffer = format_srp_header_with_length,
+  .format_trace = format_srp_input_trace,
+  .unformat_buffer = unformat_srp_header,
+};
+
+static uword
+srp_topology_packet (vlib_main_t * vm, u32 sw_if_index, u8 ** contents)
+{
+  vnet_main_t * vnm = vnet_get_main();
+  vnet_hw_interface_t * hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
+  srp_topology_header_t * t;
+  srp_topology_mac_binding_t * mb;
+  u32 nb, nmb;
+
+  t = (void *) *contents;
+
+  nb = clib_net_to_host_u16 (t->n_bytes_of_data_that_follows);
+  nmb = (nb - sizeof (t->originator_address)) / sizeof (mb[0]);
+  if (vec_len (*contents) < sizeof (t[0]) + nmb * sizeof (mb[0]))
+    return SRP_ERROR_TOPOLOGY_BAD_LENGTH;
+
+  /* Fill in our source MAC address. */
+  clib_memcpy (t->ethernet.src_address, hi->hw_address, vec_len (hi->hw_address));
+
+  /* Make space for our MAC binding. */
+  vec_resize (*contents, sizeof (srp_topology_mac_binding_t));
+  t = (void *) *contents;
+  t->n_bytes_of_data_that_follows = clib_host_to_net_u16 (nb + sizeof (mb[0]));
+
+  mb = t->bindings + nmb;
+
+  mb->flags =
+    ((t->srp.is_inner_ring ? SRP_TOPOLOGY_MAC_BINDING_FLAG_IS_INNER_RING : 0)
+     | (/* is wrapped FIXME */ 0));
+  clib_memcpy (mb->address, hi->hw_address, vec_len (hi->hw_address));
+
+  t->control.checksum
+    = ~ip_csum_fold (ip_incremental_checksum (0, &t->control,
+					      vec_len (*contents) - STRUCT_OFFSET_OF (srp_generic_control_header_t, control)));
+
+  {
+    vlib_frame_t * f = vlib_get_frame_to_node (vm, hi->output_node_index);
+    vlib_buffer_t * b;
+    u32 * to_next = vlib_frame_vector_args (f);
+    u32 bi;
+
+    bi = vlib_buffer_add_data (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX,
+			       /* buffer to append to */ 0,
+			       *contents, vec_len (*contents));
+    b = vlib_get_buffer (vm, bi);
+    vnet_buffer (b)->sw_if_index[VLIB_RX] = vnet_buffer (b)->sw_if_index[VLIB_TX] = sw_if_index;
+    to_next[0] = bi;
+    f->n_vectors = 1;
+    vlib_put_frame_to_node (vm, hi->output_node_index, f);
+  }
+
+  return SRP_ERROR_CONTROL_PACKETS_PROCESSED;
+}
+
+typedef uword (srp_control_handler_function_t) (vlib_main_t * vm,
+						u32 sw_if_index,
+						u8 ** contents);
+
+static uword
+srp_control_input (vlib_main_t * vm,
+		   vlib_node_runtime_t * node,
+		   vlib_frame_t * from_frame)
+{
+  u32 n_left_from, next_index, * from, * to_next;
+  vlib_node_runtime_t * error_node;
+  static u8 * contents;
+
+  error_node = vlib_node_get_runtime (vm, srp_input_node.index);
+
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+
+  if (node->flags & VLIB_NODE_FLAG_TRACE)
+    vlib_trace_frame_buffers_only (vm, node,
+				   from,
+				   n_left_from,
+				   sizeof (from[0]),
+				   sizeof (srp_input_trace_t));
+
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0, l2_len0, l3_len0;
+	  vlib_buffer_t * b0;
+	  u8 next0, error0;
+	  srp_generic_control_header_t * s0;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_to_next -= 1;
+	  n_left_from -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+	  s0 = (void *) (b0->data + b0->current_data);
+	  l2_len0 = vlib_buffer_length_in_chain (vm, b0);
+	  l3_len0 = l2_len0 - STRUCT_OFFSET_OF (srp_generic_control_header_t, control);
+
+	  error0 = SRP_ERROR_CONTROL_PACKETS_PROCESSED;
+
+	  error0 = s0->control.version != 0 ? SRP_ERROR_CONTROL_VERSION_NON_ZERO : error0;
+
+	  {
+	    u16 save0 = s0->control.checksum;
+	    u16 computed0;
+	    s0->control.checksum = 0;
+	    computed0 = ~ip_csum_fold (ip_incremental_checksum (0, &s0->control, l3_len0));
+	    error0 = save0 != computed0 ? SRP_ERROR_CONTROL_BAD_CHECKSUM : error0;
+	  }
+
+	  if (error0 == SRP_ERROR_CONTROL_PACKETS_PROCESSED)
+	    {
+	      static srp_control_handler_function_t * t[SRP_N_CONTROL_PACKET_TYPE] = {
+		[SRP_CONTROL_PACKET_TYPE_topology] = srp_topology_packet,
+	      };
+	      srp_control_handler_function_t * f;
+
+	      f = 0;
+	      if (s0->control.type < ARRAY_LEN (t))
+		f = t[s0->control.type];
+
+	      if (f)
+		{
+		  vec_validate (contents, l2_len0 - 1);
+		  vlib_buffer_contents (vm, bi0, contents);
+		  error0 = f (vm, vnet_buffer (b0)->sw_if_index[VLIB_RX], &contents);
+		}
+	      else
+		error0 = SRP_ERROR_UNKNOWN_CONTROL;
+	    }
+
+	  b0->error = error_node->errors[error0];
+	  next0 = 0;
+
+	  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 from_frame->n_vectors;
+}
+
+static vlib_node_registration_t srp_control_input_node = {
+  .function = srp_control_input,
+  .name = "srp-control",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_next_nodes = 1,
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+
+  .format_buffer = format_srp_header_with_length,
+  .format_trace = format_srp_input_trace,
+  .unformat_buffer = unformat_srp_header,
+};
+
+static u8 * format_srp_ips_request_type (u8 * s, va_list * args)
+{
+  u32 x = va_arg (*args, u32);
+  char * t = 0;
+  switch (x)
+    {
+#define _(f,n) case SRP_IPS_REQUEST_##f: t = #f; break;
+      foreach_srp_ips_request_type
+#undef _
+    default:
+      return format (s, "unknown 0x%x", x);
+    }
+  return format (s, "%U", format_c_identifier, t);
+}
+
+static u8 * format_srp_ips_status (u8 * s, va_list * args)
+{
+  u32 x = va_arg (*args, u32);
+  char * t = 0;
+  switch (x)
+    {
+#define _(f,n) case SRP_IPS_STATUS_##f: t = #f; break;
+      foreach_srp_ips_status
+#undef _
+    default:
+      return format (s, "unknown 0x%x", x);
+    }
+  return format (s, "%U", format_c_identifier, t);
+}
+
+static u8 * format_srp_ips_state (u8 * s, va_list * args)
+{
+  u32 x = va_arg (*args, u32);
+  char * t = 0;
+  switch (x)
+    {
+#define _(f) case SRP_IPS_STATE_##f: t = #f; break;
+      foreach_srp_ips_state
+#undef _
+    default:
+      return format (s, "unknown 0x%x", x);
+    }
+  return format (s, "%U", format_c_identifier, t);
+}
+
+static u8 * format_srp_ring (u8 * s, va_list * args)
+{
+  u32 ring = va_arg (*args, u32);
+  return format (s, "%s", ring == SRP_RING_INNER ? "inner" : "outer");
+}
+
+static u8 * format_srp_ips_header (u8 * s, va_list * args)
+{
+  srp_ips_header_t * h = va_arg (*args, srp_ips_header_t *);
+
+  s = format (s, "%U, %U, %U, %s-path",
+	      format_srp_ips_request_type, h->request_type,
+	      format_ethernet_address, h->originator_address,
+	      format_srp_ips_status, h->status,
+	      h->is_long_path ? "long" : "short");
+
+  return s;
+}
+
+static u8 * format_srp_interface (u8 * s, va_list * args)
+{
+  srp_interface_t * si = va_arg (*args, srp_interface_t *);
+  srp_interface_ring_t * ir;
+
+  s = format (s, "address %U, IPS state %U",
+	      format_ethernet_address, si->my_address,
+	      format_srp_ips_state, si->current_ips_state);
+  for (ir = si->rings; ir < si->rings + SRP_N_RING; ir++)
+    if (ir->rx_neighbor_address_valid)
+      s = format (s, ", %U neighbor %U",
+		  format_srp_ring, ir->ring,
+		  format_ethernet_address, ir->rx_neighbor_address);
+
+  return s;
+}
+
+u8 * format_srp_device (u8 * s, va_list * args)
+{
+  u32 hw_if_index = va_arg (*args, u32);
+  CLIB_UNUSED (int verbose) = va_arg (*args, int);
+  vnet_main_t * vnm = vnet_get_main();
+  srp_main_t * sm = &srp_main;
+  vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, hw_if_index);
+  srp_interface_t * si = pool_elt_at_index (sm->interface_pool, hi->hw_instance);
+  return format (s, "%U", format_srp_interface, si);
+}
+
+always_inline srp_interface_t *
+srp_get_interface (u32 sw_if_index, srp_ring_type_t * ring)
+{
+  vnet_main_t * vnm = vnet_get_main();
+  srp_main_t * sm = &srp_main;
+  vnet_hw_interface_t * hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
+  srp_interface_t * si;
+
+  ASSERT (hi->hw_class_index == srp_hw_interface_class.index);
+  si = pool_elt_at_index (sm->interface_pool, hi->hw_instance);
+
+  ASSERT (si->rings[SRP_RING_INNER].hw_if_index == hi->hw_if_index
+	  || si->rings[SRP_RING_OUTER].hw_if_index == hi->hw_if_index);
+  if (ring)
+    *ring =
+      (hi->hw_if_index == si->rings[SRP_RING_INNER].hw_if_index
+       ? SRP_RING_INNER
+       : SRP_RING_OUTER);
+
+  return si;
+}
+
+static void init_ips_packet (srp_interface_t * si,
+			     srp_ring_type_t tx_ring,
+			     srp_ips_header_t * i)
+{
+  memset (i, 0, sizeof (i[0]));
+
+  i->srp.ttl = 1;
+  i->srp.is_inner_ring = tx_ring;
+  i->srp.priority = 7;
+  i->srp.mode = SRP_MODE_control_locally_buffered_for_host;
+  srp_header_compute_parity (&i->srp);
+
+  clib_memcpy (&i->ethernet.src_address, &si->my_address, sizeof (si->my_address));
+  i->ethernet.type = clib_host_to_net_u16 (ETHERNET_TYPE_SRP_CONTROL);
+
+  /* Checksum will be filled in later. */
+  i->control.version = 0;
+  i->control.type = SRP_CONTROL_PACKET_TYPE_ips;
+  i->control.ttl = 255;
+
+  clib_memcpy (&i->originator_address, &si->my_address, sizeof (si->my_address));
+}
+
+static void tx_ips_packet (srp_interface_t * si,
+			   srp_ring_type_t tx_ring,
+			   srp_ips_header_t * i)
+{
+  srp_main_t * sm = &srp_main;
+  vnet_main_t * vnm = vnet_get_main();
+  vlib_main_t * vm = sm->vlib_main;
+  vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, si->rings[tx_ring].hw_if_index);
+  vlib_frame_t * f;
+  vlib_buffer_t * b;
+  u32 * to_next, bi;
+
+  if (! vnet_sw_interface_is_admin_up (vnm, hi->sw_if_index))
+    return;
+  if (hi->hw_class_index != srp_hw_interface_class.index)
+    return;
+
+  i->control.checksum
+    = ~ip_csum_fold (ip_incremental_checksum (0, &i->control,
+					      sizeof (i[0]) - STRUCT_OFFSET_OF (srp_ips_header_t, control)));
+
+  bi = vlib_buffer_add_data (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX,
+			     /* buffer to append to */ 0,
+			     i, sizeof (i[0]));
+
+  /* FIXME trace. */
+  if (0)
+    clib_warning ("%U %U",
+		  format_vnet_sw_if_index_name, vnm, hi->sw_if_index,
+		  format_srp_ips_header, i);
+
+  b = vlib_get_buffer (vm, bi);
+  vnet_buffer (b)->sw_if_index[VLIB_RX] = vnet_buffer (b)->sw_if_index[VLIB_TX] = hi->sw_if_index;
+
+  f = vlib_get_frame_to_node (vm, hi->output_node_index);
+  to_next = vlib_frame_vector_args (f);
+  to_next[0] = bi;
+  f->n_vectors = 1;
+  vlib_put_frame_to_node (vm, hi->output_node_index, f);
+}
+
+static void serialize_srp_interface_state_msg (serialize_main_t * m, va_list * va)
+{
+  srp_interface_t * si = va_arg (*va, srp_interface_t *);
+  srp_main_t * sm = &srp_main;
+  int r;
+
+  ASSERT (! pool_is_free (sm->interface_pool, si));
+  serialize_integer (m, si - sm->interface_pool, sizeof (u32));
+  serialize_likely_small_unsigned_integer (m, si->current_ips_state);
+  for (r = 0; r < SRP_N_RING; r++)
+    {
+      srp_interface_ring_t * ir = &si->rings[r];
+      void * p;
+      serialize_likely_small_unsigned_integer (m, ir->rx_neighbor_address_valid);
+      if (ir->rx_neighbor_address_valid)
+	{
+	  p = serialize_get (m, sizeof (ir->rx_neighbor_address));
+	  clib_memcpy (p, ir->rx_neighbor_address, sizeof (ir->rx_neighbor_address));
+	}
+      serialize_likely_small_unsigned_integer (m, ir->waiting_to_restore);
+      if (ir->waiting_to_restore)
+	serialize (m, serialize_f64, ir->wait_to_restore_start_time);
+    }
+}
+
+static void unserialize_srp_interface_state_msg (serialize_main_t * m, va_list * va)
+{
+  CLIB_UNUSED (mc_main_t * mcm) = va_arg (*va, mc_main_t *);
+  srp_main_t * sm = &srp_main;
+  srp_interface_t * si;
+  u32 si_index, r;
+
+  unserialize_integer (m, &si_index, sizeof (u32));
+  si = pool_elt_at_index (sm->interface_pool, si_index);
+  si->current_ips_state = unserialize_likely_small_unsigned_integer (m);
+  for (r = 0; r < SRP_N_RING; r++)
+    {
+      srp_interface_ring_t * ir = &si->rings[r];
+      void * p;
+      ir->rx_neighbor_address_valid = unserialize_likely_small_unsigned_integer (m);
+      if (ir->rx_neighbor_address_valid)
+	{
+	  p = unserialize_get (m, sizeof (ir->rx_neighbor_address));
+	  clib_memcpy (ir->rx_neighbor_address, p, sizeof (ir->rx_neighbor_address));
+	}
+      ir->waiting_to_restore = unserialize_likely_small_unsigned_integer (m);
+      if (ir->waiting_to_restore)
+	unserialize (m, unserialize_f64, &ir->wait_to_restore_start_time);
+    }
+}
+
+MC_SERIALIZE_MSG (srp_interface_state_msg, static) = {
+  .name = "vnet_srp_interface_state",
+  .serialize = serialize_srp_interface_state_msg,
+  .unserialize = unserialize_srp_interface_state_msg,
+};
+
+static int requests_switch (srp_ips_request_type_t r)
+{
+  static u8 t[16] = {
+    [SRP_IPS_REQUEST_forced_switch] = 1,
+    [SRP_IPS_REQUEST_manual_switch] = 1,
+    [SRP_IPS_REQUEST_signal_fail] = 1,
+    [SRP_IPS_REQUEST_signal_degrade] = 1,
+  };
+  return (int) r < ARRAY_LEN (t) ? t[r] : 0;
+}
+
+/* Called when an IPS control packet is received on given interface. */
+void srp_ips_rx_packet (u32 sw_if_index, srp_ips_header_t * h)
+{
+  vnet_main_t * vnm = vnet_get_main();
+  vlib_main_t * vm = srp_main.vlib_main;
+  srp_ring_type_t rx_ring;
+  srp_interface_t * si = srp_get_interface (sw_if_index, &rx_ring);
+  srp_interface_ring_t * ir = &si->rings[rx_ring];
+  int si_needs_broadcast = 0;
+
+  /* FIXME trace. */
+  if (0)
+    clib_warning ("%U %U %U",
+		  format_time_interval, "h:m:s:u", vlib_time_now (vm),
+		  format_vnet_sw_if_index_name, vnm, sw_if_index,
+		  format_srp_ips_header, h);
+
+  /* Ignore self-generated IPS packets. */
+  if (! memcmp (h->originator_address, si->my_address, sizeof (h->originator_address)))
+    goto done;
+
+  /* Learn neighbor address from short path messages. */
+  if (! h->is_long_path)
+    {
+      if (ir->rx_neighbor_address_valid
+	  && memcmp (ir->rx_neighbor_address, h->originator_address, sizeof (ir->rx_neighbor_address)))
+	{
+	  ASSERT (0);
+	}
+      ir->rx_neighbor_address_valid = 1;
+      clib_memcpy (ir->rx_neighbor_address, h->originator_address, sizeof (ir->rx_neighbor_address));
+    }
+
+  switch (si->current_ips_state)
+    {
+    case SRP_IPS_STATE_idle:
+      /* Received {REQ,NEIGHBOR,W,S} in idle state: wrap. */
+      if (requests_switch (h->request_type)
+	  && ! h->is_long_path
+	  && h->status == SRP_IPS_STATUS_wrapped)
+	{
+	  srp_ips_header_t to_tx[2];
+
+	  si_needs_broadcast = 1;
+	  si->current_ips_state = SRP_IPS_STATE_wrapped;
+	  si->hw_wrap_function (si->rings[SRP_SIDE_A].hw_if_index, /* enable_wrap */ 1);
+	  si->hw_wrap_function (si->rings[SRP_SIDE_B].hw_if_index, /* enable_wrap */ 1);
+
+	  init_ips_packet (si, rx_ring ^ 0, &to_tx[0]);
+	  to_tx[0].request_type = SRP_IPS_REQUEST_idle;
+	  to_tx[0].status = SRP_IPS_STATUS_wrapped;
+	  to_tx[0].is_long_path = 0;
+	  tx_ips_packet (si, rx_ring ^ 0, &to_tx[0]);
+
+	  init_ips_packet (si, rx_ring ^ 1, &to_tx[1]);
+	  to_tx[1].request_type = h->request_type;
+	  to_tx[1].status = SRP_IPS_STATUS_wrapped;
+	  to_tx[1].is_long_path = 1;
+	  tx_ips_packet (si, rx_ring ^ 1, &to_tx[1]);
+	}
+      break;
+
+    case SRP_IPS_STATE_wrapped:
+      if (! h->is_long_path
+	  && h->request_type == SRP_IPS_REQUEST_idle
+	  && h->status == SRP_IPS_STATUS_idle)
+	{
+	  si_needs_broadcast = 1;
+	  si->current_ips_state = SRP_IPS_STATE_idle;
+	  si->hw_wrap_function (si->rings[SRP_SIDE_A].hw_if_index, /* enable_wrap */ 0);
+	  si->hw_wrap_function (si->rings[SRP_SIDE_B].hw_if_index, /* enable_wrap */ 0);
+	}
+      break;
+
+    case SRP_IPS_STATE_pass_thru:
+      /* FIXME */
+      break;
+
+    default:
+      abort ();
+      break;
+    }
+
+ done:
+  if (vm->mc_main && si_needs_broadcast)
+    mc_serialize (vm->mc_main, &srp_interface_state_msg, si);
+}
+
+/* Preform local IPS request on given interface. */
+void srp_ips_local_request (u32 sw_if_index, srp_ips_request_type_t request)
+{
+  vnet_main_t * vnm = vnet_get_main();
+  srp_main_t * sm = &srp_main;
+  vlib_main_t * vm = sm->vlib_main;
+  srp_ring_type_t rx_ring;
+  srp_interface_t * si = srp_get_interface (sw_if_index, &rx_ring);
+  srp_interface_ring_t * ir = &si->rings[rx_ring];
+  int si_needs_broadcast = 0;
+
+  if (request == SRP_IPS_REQUEST_wait_to_restore)
+    {
+      if (si->current_ips_state != SRP_IPS_STATE_wrapped)
+	return;
+      if (! ir->waiting_to_restore)
+	{
+	  ir->wait_to_restore_start_time = vlib_time_now (sm->vlib_main);
+	  ir->waiting_to_restore = 1;
+	  si_needs_broadcast = 1;
+	}
+    }
+  else
+    {
+      /* FIXME handle local signal fail. */
+      si_needs_broadcast = ir->waiting_to_restore;
+      ir->wait_to_restore_start_time = 0;
+      ir->waiting_to_restore = 0;
+    }
+
+  /* FIXME trace. */
+  if (0)
+    clib_warning ("%U %U",
+		  format_vnet_sw_if_index_name, vnm, sw_if_index,
+		  format_srp_ips_request_type, request);
+
+  if (vm->mc_main && si_needs_broadcast)
+    mc_serialize (vm->mc_main, &srp_interface_state_msg, si);
+}
+
+static void maybe_send_ips_message (srp_interface_t * si)
+{
+  srp_main_t * sm = &srp_main;
+  srp_ips_header_t to_tx[2];
+  srp_ring_type_t rx_ring = SRP_RING_OUTER;
+  srp_interface_ring_t * r0 = &si->rings[rx_ring ^ 0];
+  srp_interface_ring_t * r1 = &si->rings[rx_ring ^ 1];
+  f64 now = vlib_time_now (sm->vlib_main);
+
+  if (! si->ips_process_enable)
+    return;
+
+  if (si->current_ips_state == SRP_IPS_STATE_wrapped
+      && r0->waiting_to_restore
+      && r1->waiting_to_restore
+      && now >= r0->wait_to_restore_start_time + si->config.wait_to_restore_idle_delay
+      && now >= r1->wait_to_restore_start_time + si->config.wait_to_restore_idle_delay)
+    {
+      si->current_ips_state = SRP_IPS_STATE_idle;
+      r0->waiting_to_restore = r1->waiting_to_restore = 0;
+      r0->wait_to_restore_start_time = r1->wait_to_restore_start_time = 0;
+    }
+
+  if (si->current_ips_state != SRP_IPS_STATE_idle)
+    return;
+
+  init_ips_packet (si, rx_ring ^ 0, &to_tx[0]);
+  init_ips_packet (si, rx_ring ^ 1, &to_tx[1]);
+
+  if (si->current_ips_state == SRP_IPS_STATE_idle)
+    {
+      to_tx[0].request_type = to_tx[1].request_type = SRP_IPS_REQUEST_idle;
+      to_tx[0].status = to_tx[1].status = SRP_IPS_STATUS_idle;
+      to_tx[0].is_long_path = to_tx[1].is_long_path = 0;
+    }
+
+  else if (si->current_ips_state == SRP_IPS_STATE_wrapped)
+    {
+      to_tx[0].request_type =
+	(si->rings[rx_ring ^ 0].waiting_to_restore
+	 ? SRP_IPS_REQUEST_wait_to_restore
+	 : SRP_IPS_REQUEST_signal_fail);
+      to_tx[1].request_type =
+	(si->rings[rx_ring ^ 1].waiting_to_restore
+	 ? SRP_IPS_REQUEST_wait_to_restore
+	 : SRP_IPS_REQUEST_signal_fail);
+      to_tx[0].status = to_tx[1].status = SRP_IPS_STATUS_wrapped;
+      to_tx[0].is_long_path = 0;
+      to_tx[1].is_long_path = 1;
+    }
+
+  tx_ips_packet (si, rx_ring ^ 0, &to_tx[0]);
+  tx_ips_packet (si, rx_ring ^ 1, &to_tx[1]);
+}
+
+static uword
+srp_ips_process (vlib_main_t * vm,
+		 vlib_node_runtime_t * rt,
+		 vlib_frame_t * f)
+{
+  srp_main_t * sm = &srp_main;
+  srp_interface_t * si;
+
+  while (1)
+    {
+      pool_foreach (si, sm->interface_pool, ({
+	maybe_send_ips_message (si);
+      }));
+      vlib_process_suspend (vm, 1.0);
+    }
+
+  return 0;
+}
+
+vlib_node_registration_t srp_ips_process_node = {
+    .function = srp_ips_process,
+    .type = VLIB_NODE_TYPE_PROCESS,
+    .name = "srp-ips-process",
+    .state = VLIB_NODE_STATE_DISABLED,
+};
+
+static clib_error_t * srp_init (vlib_main_t * vm)
+{
+  srp_main_t * sm = &srp_main;
+
+  sm->default_data_ttl = 255;
+  sm->vlib_main = vm;
+  vlib_register_node (vm, &srp_ips_process_node);
+  vlib_register_node (vm, &srp_input_node);
+  vlib_register_node (vm, &srp_control_input_node);
+  srp_setup_node (vm, srp_input_node.index);
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (srp_init);