L3 cross connect

- all packets input on interface X are load-balanced over the set of
paths provided.

Change-Id: Ic27cb88c4cd5d6d3462570632daff7a43d5a652d
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 395 insertions, 0 deletions

diff --git a/src/plugins/l3xc/l3xc.c b/src/plugins/l3xc/l3xc.c
new file mode 100644
index 00000000000..77c062f39d6
--- /dev/null
+++ b/src/plugins/l3xc/l3xc.c
@@ -0,0 +1,395 @@
+/*
+ * Copyright (c) 2018 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 <plugins/l3xc/l3xc.h>
+
+#include <vlib/vlib.h>
+#include <vnet/plugin/plugin.h>
+#include <vnet/fib/fib_path_list.h>
+
+/**
+ * FIB node type the attachment is registered
+ */
+fib_node_type_t l3xc_fib_node_type;
+
+/**
+ * Pool of L3XC objects
+ */
+l3xc_t *l3xc_pool;
+
+/**
+ * DB of L3XC objects
+ */
+static u32 *l3xc_db[FIB_PROTOCOL_IP_MAX];
+
+index_t
+l3xc_find (u32 sw_if_index, fib_protocol_t fproto)
+{
+  if (vec_len (l3xc_db[fproto]) <= sw_if_index)
+    return ~0;
+
+  return (l3xc_db[fproto][sw_if_index]);
+}
+
+static void
+l3xc_db_add (u32 sw_if_index, fib_protocol_t fproto, index_t l3xci)
+{
+  vec_validate_init_empty (l3xc_db[fproto], sw_if_index, ~0);
+
+  l3xc_db[fproto][sw_if_index] = l3xci;
+}
+
+static void
+l3xc_db_remove (u32 sw_if_index, fib_protocol_t fproto)
+{
+  vec_validate_init_empty (l3xc_db[fproto], sw_if_index, ~0);
+
+  l3xc_db[fproto][sw_if_index] = ~0;
+}
+
+static void
+l3xc_stack (l3xc_t * l3xc)
+{
+  /*
+   * stack the DPO on the forwarding contributed by the path-list
+   */
+  dpo_id_t via_dpo = DPO_INVALID;
+
+  fib_path_list_contribute_forwarding (l3xc->l3xc_pl,
+				       (FIB_PROTOCOL_IP4 == l3xc->l3xc_proto ?
+					FIB_FORW_CHAIN_TYPE_UNICAST_IP4 :
+					FIB_FORW_CHAIN_TYPE_UNICAST_IP6),
+				       FIB_PATH_LIST_FWD_FLAG_NONE, &via_dpo);
+
+  dpo_stack_from_node ((FIB_PROTOCOL_IP4 == l3xc->l3xc_proto ?
+			l3xc_ip4_node.index :
+			l3xc_ip6_node.index), &l3xc->l3xc_dpo, &via_dpo);
+  dpo_reset (&via_dpo);
+}
+
+int
+l3xc_update (u32 sw_if_index, u8 is_ip6, const fib_route_path_t * rpaths)
+{
+  fib_protocol_t fproto;
+  l3xc_t *l3xc;
+  u32 l3xci;
+
+  fproto = (is_ip6 ? FIB_PROTOCOL_IP6 : FIB_PROTOCOL_IP4);
+
+  l3xci = l3xc_find (sw_if_index, fproto);
+
+  if (INDEX_INVALID == l3xci)
+    {
+      /*
+       * create a new x-connect
+       */
+      pool_get_aligned_zero (l3xc_pool, l3xc, CLIB_CACHE_LINE_BYTES);
+
+      l3xci = l3xc - l3xc_pool;
+      fib_node_init (&l3xc->l3xc_node, l3xc_fib_node_type);
+      l3xc->l3xc_sw_if_index = sw_if_index;
+      l3xc->l3xc_proto = fproto;
+
+      /*
+       * create and become a child of a path list so we get poked when
+       * the forwarding changes and stack on the DPO the path-list provides
+       */
+      l3xc->l3xc_pl = fib_path_list_create ((FIB_PATH_LIST_FLAG_SHARED |
+					     FIB_PATH_LIST_FLAG_NO_URPF),
+					    rpaths);
+      l3xc->l3xc_sibling = fib_path_list_child_add (l3xc->l3xc_pl,
+						    l3xc_fib_node_type,
+						    l3xci);
+      l3xc_stack (l3xc);
+
+      /*
+       * add this new policy to the DB and enable the feature on input interface
+       */
+      l3xc_db_add (sw_if_index, fproto, l3xci);
+
+      vnet_feature_enable_disable ((FIB_PROTOCOL_IP4 == fproto ?
+				    "ip4-unicast" :
+				    "ip6-unicast"),
+				   (FIB_PROTOCOL_IP4 == fproto ?
+				    "l3xc-input-ip4" :
+				    "l3xc-input-ip6"),
+				   l3xc->l3xc_sw_if_index,
+				   1, &l3xci, sizeof (l3xci));
+    }
+  else
+    {
+      /*
+       * update an existing x-connect.
+       * - add the path to the path-list and swap our ancestry
+       */
+      l3xc = l3xc_get (l3xci);
+
+      if (FIB_NODE_INDEX_INVALID != l3xc->l3xc_pl)
+	{
+	  fib_path_list_child_remove (l3xc->l3xc_pl, l3xc->l3xc_sibling);
+	}
+
+      l3xc->l3xc_pl = fib_path_list_create ((FIB_PATH_LIST_FLAG_SHARED |
+					     FIB_PATH_LIST_FLAG_NO_URPF),
+					    rpaths);
+
+      l3xc->l3xc_sibling = fib_path_list_child_add (l3xc->l3xc_pl,
+						    l3xc_fib_node_type,
+						    l3xci);
+    }
+  return (0);
+}
+
+int
+l3xc_delete (u32 sw_if_index, u8 is_ip6)
+{
+  fib_protocol_t fproto;
+  l3xc_t *l3xc;
+  u32 l3xci;
+
+  fproto = (is_ip6 ? FIB_PROTOCOL_IP6 : FIB_PROTOCOL_IP4);
+
+  l3xci = l3xc_find (sw_if_index, fproto);
+
+  if (INDEX_INVALID == l3xci)
+    {
+      /*
+       * no such policy
+       */
+      return (VNET_API_ERROR_INVALID_VALUE);
+    }
+  else
+    {
+      l3xc = l3xc_get (l3xci);
+
+      vnet_feature_enable_disable ((FIB_PROTOCOL_IP4 == fproto ?
+				    "ip4-unicast" :
+				    "ip6-unicast"),
+				   (FIB_PROTOCOL_IP4 == fproto ?
+				    "l3xc-input-ip4" :
+				    "l3xc-input-ip6"),
+				   l3xc->l3xc_sw_if_index,
+				   0, &l3xci, sizeof (l3xci));
+
+      fib_path_list_child_remove (l3xc->l3xc_pl, l3xc->l3xc_sibling);
+
+      l3xc_db_remove (l3xc->l3xc_sw_if_index, fproto);
+      pool_put (l3xc_pool, l3xc);
+    }
+
+  return (0);
+}
+
+static clib_error_t *
+l3xc_cmd (vlib_main_t * vm,
+	  unformat_input_t * main_input, vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  fib_route_path_t *rpaths = NULL, rpath;
+  u32 sw_if_index, is_del, is_ip6;
+  vnet_main_t *vnm;
+  int rv = 0;
+
+  is_ip6 = is_del = 0;
+  sw_if_index = ~0;
+  vnm = vnet_get_main ();
+
+  /* Get a line of input. */
+  if (!unformat_user (main_input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat
+	  (line_input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index))
+	;
+      else if (unformat (line_input, "ip6"))
+	is_ip6 = 1;
+      else if (unformat (line_input, "ip4"))
+	is_ip6 = 0;
+      else if (unformat (line_input, "del"))
+	is_del = 1;
+      else if (unformat (line_input, "add"))
+	is_del = 0;
+      else if (unformat (line_input, "via %U",
+			 unformat_fib_route_path, &rpath))
+	vec_add1 (rpaths, rpath);
+      else
+	return (clib_error_return (0, "unknown input '%U'",
+				   format_unformat_error, line_input));
+    }
+
+  if (~0 == sw_if_index)
+    {
+      vlib_cli_output (vm, "Specify an input interface");
+      goto out;
+    }
+  if (vec_len (rpaths) == 0)
+    {
+      vlib_cli_output (vm, "Specify some paths");
+      goto out;
+    }
+
+  if (!is_del)
+    {
+      rv = l3xc_update (sw_if_index, is_ip6, rpaths);
+
+      if (rv)
+	{
+	  vlib_cli_output (vm, "Failed: %d", rv);
+	  goto out;
+	}
+    }
+  else
+    {
+      l3xc_delete (sw_if_index, is_ip6);
+    }
+
+out:
+  unformat_free (line_input);
+  return (NULL);
+}
+
+/* *INDENT-OFF* */
+/**
+ * Create an L3XC policy.
+ */
+VLIB_CLI_COMMAND (l3xc_cmd_node, static) = {
+  .path = "l3xc",
+  .function = l3xc_cmd,
+  .short_help = "l3xc [add|del] <INTERFACE> via ...",
+  .is_mp_safe = 1,
+};
+/* *INDENT-ON* */
+
+static u8 *
+format_l3xc (u8 * s, va_list * args)
+{
+  l3xc_t *l3xc = va_arg (*args, l3xc_t *);
+  vnet_main_t *vnm = vnet_get_main ();
+
+  s = format (s, "l3xc:[%d]: %U",
+	      l3xc - l3xc_pool, format_vnet_sw_if_index_name,
+	      vnm, l3xc->l3xc_sw_if_index);
+  s = format (s, "\n");
+  if (FIB_NODE_INDEX_INVALID == l3xc->l3xc_pl)
+    {
+      s = format (s, "no forwarding");
+    }
+  else
+    {
+      s = fib_path_list_format (l3xc->l3xc_pl, s);
+
+      s = format (s, "\n  %U", format_dpo_id, &l3xc->l3xc_dpo, 4);
+    }
+
+  return (s);
+}
+
+void
+l3xc_walk (l3xc_walk_cb_t cb, void *ctx)
+{
+  u32 l3xci;
+
+  /* *INDENT-OFF* */
+  pool_foreach_index(l3xci, l3xc_pool,
+  ({
+    if (!cb(l3xci, ctx))
+      break;
+  }));
+  /* *INDENT-ON* */
+}
+
+static clib_error_t *
+l3xc_show_cmd (vlib_main_t * vm,
+	       unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  l3xc_t *l3xc;
+
+  /* *INDENT-OFF* */
+  pool_foreach(l3xc, l3xc_pool,
+  ({
+    vlib_cli_output(vm, "%U", format_l3xc, l3xc);
+  }));
+  /* *INDENT-ON* */
+
+  return (NULL);
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (l3xc_show_cmd_node, static) = {
+  .path = "show l3xc",
+  .function = l3xc_show_cmd,
+  .short_help = "show l3xc",
+  .is_mp_safe = 1,
+};
+/* *INDENT-ON* */
+
+static fib_node_t *
+l3xc_get_node (fib_node_index_t index)
+{
+  l3xc_t *l3xc = l3xc_get (index);
+  return (&(l3xc->l3xc_node));
+}
+
+static l3xc_t *
+l3xc_get_from_node (fib_node_t * node)
+{
+  return ((l3xc_t *) (((char *) node) -
+		      STRUCT_OFFSET_OF (l3xc_t, l3xc_node)));
+}
+
+static void
+l3xc_last_lock_gone (fib_node_t * node)
+{
+}
+
+/*
+ * A back walk has reached this L3XC policy
+ */
+static fib_node_back_walk_rc_t
+l3xc_back_walk_notify (fib_node_t * node, fib_node_back_walk_ctx_t * ctx)
+{
+  l3xc_stack (l3xc_get_from_node (node));
+
+  return (FIB_NODE_BACK_WALK_CONTINUE);
+}
+
+/*
+ * The BIER fmask's graph node virtual function table
+ */
+static const fib_node_vft_t l3xc_vft = {
+  .fnv_get = l3xc_get_node,
+  .fnv_last_lock = l3xc_last_lock_gone,
+  .fnv_back_walk = l3xc_back_walk_notify,
+};
+
+static clib_error_t *
+l3xc_init (vlib_main_t * vm)
+{
+  l3xc_fib_node_type = fib_node_register_new_type (&l3xc_vft);
+
+  return (NULL);
+}
+
+VLIB_INIT_FUNCTION (l3xc_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */