BVI Interface

a new dedicated BVI interface as opposed to [re]using a loopback.

benefits:
 - removes ambiguity over the purpose of a loopback interface
 - TX node dedicated to BVI only functions.

Change-Id: I749d6b38440d450ac5b909a28053c75ec9df946a
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 311 insertions, 0 deletions

diff --git a/src/vnet/l2/l2_bvi.c b/src/vnet/l2/l2_bvi.c
index f239743a9c4..87738fc7820 100644
--- a/src/vnet/l2/l2_bvi.c
+++ b/src/vnet/l2/l2_bvi.c
@@ -21,6 +21,8 @@
 #include <vnet/l2/l2_flood.h>
 #include <vnet/l2/l2_bvi.h>
 
+/* Allocated BVI instances */
+static uword *l2_bvi_instances;
 
 /* Call the L2 nodes that need the ethertype mapping */
 void
@@ -31,6 +33,315 @@ l2bvi_register_input_type (vlib_main_t * vm,
   l2flood_register_input_type (vm, type, node_index);
 }
 
+static u8 *
+format_bvi_name (u8 * s, va_list * args)
+{
+  u32 dev_instance = va_arg (*args, u32);
+  return format (s, "bvi%d", dev_instance);
+}
+
+static clib_error_t *
+bvi_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
+{
+  u32 hw_flags = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) ?
+    VNET_HW_INTERFACE_FLAG_LINK_UP : 0;
+  vnet_hw_interface_set_flags (vnm, hw_if_index, hw_flags);
+  return 0;
+}
+
+static clib_error_t *
+bvi_mac_change (vnet_hw_interface_t * hi,
+		const u8 * old_address, const u8 * mac_address)
+{
+  l2input_interface_mac_change (hi->sw_if_index, old_address, mac_address);
+
+  return (NULL);
+}
+
+/* *INDENT-OFF* */
+VNET_DEVICE_CLASS (bvi_device_class) = {
+  .name = "BVI",
+  .format_device_name = format_bvi_name,
+  .admin_up_down_function = bvi_admin_up_down,
+  .mac_addr_change_function = bvi_mac_change,
+};
+/* *INDENT-ON* */
+
+/*
+ * Maintain a bitmap of allocated bvi instance numbers.
+ */
+#define BVI_MAX_INSTANCE		(16 * 1024)
+
+static u32
+bvi_instance_alloc (u32 want)
+{
+  /*
+   * Check for dynamically allocaetd instance number.
+   */
+  if (~0 == want)
+    {
+      u32 bit;
+
+      bit = clib_bitmap_first_clear (l2_bvi_instances);
+      if (bit >= BVI_MAX_INSTANCE)
+	{
+	  return ~0;
+	}
+      l2_bvi_instances = clib_bitmap_set (l2_bvi_instances, bit, 1);
+      return bit;
+    }
+
+  /*
+   * In range?
+   */
+  if (want >= BVI_MAX_INSTANCE)
+    {
+      return ~0;
+    }
+
+  /*
+   * Already in use?
+   */
+  if (clib_bitmap_get (l2_bvi_instances, want))
+    {
+      return ~0;
+    }
+
+  /*
+   * Grant allocation request.
+   */
+  l2_bvi_instances = clib_bitmap_set (l2_bvi_instances, want, 1);
+
+  return want;
+}
+
+static int
+bvi_instance_free (u32 instance)
+{
+  if (instance >= BVI_MAX_INSTANCE)
+    {
+      return -1;
+    }
+
+  if (clib_bitmap_get (l2_bvi_instances, instance) == 0)
+    {
+      return -1;
+    }
+
+  l2_bvi_instances = clib_bitmap_set (l2_bvi_instances, instance, 0);
+  return 0;
+}
+
+int
+l2_bvi_create (u32 user_instance,
+	       const mac_address_t * mac_in, u32 * sw_if_indexp)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  vlib_main_t *vm = vlib_get_main ();
+  u32 instance, hw_if_index, slot;
+  vnet_hw_interface_t *hw_if;
+  clib_error_t *error;
+  mac_address_t mac;
+
+  int rv = 0;
+
+  ASSERT (sw_if_indexp);
+
+  *sw_if_indexp = (u32) ~ 0;
+
+  /*
+   * Allocate a bvi instance.  Either select on dynamically
+   * or try to use the desired user_instance number.
+   */
+  instance = bvi_instance_alloc (user_instance);
+  if (instance == ~0)
+    {
+      return VNET_API_ERROR_INVALID_REGISTRATION;
+    }
+
+  /*
+   * Default MAC address (b0b0:0000:0000 + instance) is allocated
+   * if zero mac_address is configured. Otherwise, user-configurable MAC
+   * address is programmed on the bvi interface.
+   */
+  if (mac_address_is_zero (mac_in))
+    {
+      u8 bytes[] = {
+	[0] = 0xb0,
+	[1] = 0xb0,
+	[5] = instance,
+      };
+      mac_address_from_bytes (&mac, bytes);
+    }
+  else
+    {
+      mac_address_copy (&mac, mac_in);
+    }
+
+  error = ethernet_register_interface (vnm,
+				       bvi_device_class.index,
+				       instance, mac.bytes, &hw_if_index,
+				       /* flag change */ 0);
+
+  if (error)
+    {
+      rv = VNET_API_ERROR_INVALID_REGISTRATION;
+      clib_error_report (error);
+      return rv;
+    }
+
+  hw_if = vnet_get_hw_interface (vnm, hw_if_index);
+
+  slot = vlib_node_add_named_next_with_slot (vm, hw_if->tx_node_index,
+					     "l2-input", 0);
+  ASSERT (slot == 0);
+
+  {
+    vnet_sw_interface_t *si = vnet_get_hw_sw_interface (vnm, hw_if_index);
+    *sw_if_indexp = si->sw_if_index;
+
+    si->flood_class = VNET_FLOOD_CLASS_BVI;
+  }
+
+  return 0;
+}
+
+int
+l2_bvi_delete (u32 sw_if_index)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+
+  if (pool_is_free_index (vnm->interface_main.sw_interfaces, sw_if_index))
+    return VNET_API_ERROR_INVALID_SW_IF_INDEX;
+
+  vnet_hw_interface_t *hw = vnet_get_sup_hw_interface (vnm, sw_if_index);
+  if (hw == 0 || hw->dev_class_index != bvi_device_class.index)
+    return VNET_API_ERROR_INVALID_SW_IF_INDEX;
+
+  if (bvi_instance_free (hw->dev_instance) < 0)
+    return VNET_API_ERROR_INVALID_SW_IF_INDEX;
+
+  ethernet_delete_interface (vnm, hw->hw_if_index);
+
+  return 0;
+}
+
+static clib_error_t *
+l2_bvi_create_cli (vlib_main_t * vm,
+		   unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  u32 instance, sw_if_index;
+  clib_error_t *error;
+  mac_address_t mac;
+  int rv;
+
+  error = NULL;
+  instance = sw_if_index = ~0;
+  mac_address_set_zero (&mac);
+
+  if (unformat_user (input, unformat_line_input, line_input))
+    {
+      while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+	{
+	  if (unformat (line_input, "mac %U", unformat_mac_address_t, &mac))
+	    ;
+	  else if (unformat (line_input, "instance %d", &instance))
+	    ;
+	  else
+	    {
+	      error = clib_error_return (0, "unknown input: %U",
+					 format_unformat_error, line_input);
+	      break;
+	    }
+	}
+
+      unformat_free (line_input);
+
+      if (error)
+	return error;
+    }
+
+  rv = l2_bvi_create (instance, &mac, &sw_if_index);
+
+  if (rv)
+    return clib_error_return (0, "BVI create failed");
+
+  vlib_cli_output (vm, "%U\n", format_vnet_sw_if_index_name, vnet_get_main (),
+		   sw_if_index);
+  return 0;
+}
+
+/*?
+ * Create a BVI interface. Optionally, a MAC Address can be
+ * provided. If not provided, 0b:0b::00:00:00:<instance> will be used.
+ *
+ * @cliexpar
+ * The following two command syntaxes are equivalent:
+ * @cliexcmd{bvi create [mac <mac-addr>] [instance <instance>]}
+ * Example of how to create a bvi interface:
+ * @cliexcmd{bvi create}
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (l2_bvi_create_command, static) = {
+  .path = "bvi create",
+  .short_help = "bvi create [mac <mac-addr>] [instance <instance>]",
+  .function = l2_bvi_create_cli,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+l2_bvi_delete_cli (vlib_main_t * vm,
+		   unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  vnet_main_t *vnm;
+  u32 sw_if_index;
+  int rv;
+
+  vnm = vnet_get_main ();
+  sw_if_index = ~0;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat
+	  (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index))
+	;
+      else
+	break;
+    }
+
+  if (~0 != sw_if_index)
+    {
+      rv = l2_bvi_delete (sw_if_index);
+
+      if (rv)
+	return clib_error_return (0, "BVI delete failed");
+    }
+  else
+    return clib_error_return (0, "no such interface: %U",
+			      format_unformat_error, input);
+
+  return 0;
+}
+
+/*?
+ * Delete a BVI interface.
+ *
+ * @cliexpar
+ * The following two command syntaxes are equivalent:
+ * @cliexcmd{bvi delete <interace>
+ * Example of how to create a bvi interface:
+ * @cliexcmd{bvi delete bvi0}
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (l2_bvi_delete_command, static) = {
+  .path = "bvi delete",
+  .short_help = "bvi delete <interface>",
+  .function = l2_bvi_delete_cli,
+};
+/* *INDENT-ON* */
+
+
 /*
  * fd.io coding-style-patch-verification: ON
  *