ipsec: Dedicated IPSec interface type

Type: feature

Signed-off-by: Neale Ranns <nranns@cisco.com>
Change-Id: Ie8bd50df163aea2798e9f9d35a13dcadc4a4a4b2

1 files changed, 462 insertions, 0 deletions

diff --git a/src/vnet/ipsec/ipsec_itf.c b/src/vnet/ipsec/ipsec_itf.c
new file mode 100644
index 00000000000..756bc19fbef
--- /dev/null
+++ b/src/vnet/ipsec/ipsec_itf.c
@@ -0,0 +1,462 @@
+/*
+ * ipsec_itf.c: IPSec dedicated interface type
+ *
+ * Copyright (c) 2020 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/ip/ip.h>
+#include <vnet/ipsec/ipsec_itf.h>
+#include <vnet/ipsec/ipsec_tun.h>
+#include <vnet/ipsec/ipsec.h>
+#include <vnet/adj/adj_midchain.h>
+
+/* bitmap of Allocated IPSEC_ITF instances */
+static uword *ipsec_itf_instances;
+
+/* pool of interfaces */
+static ipsec_itf_t *ipsec_itf_pool;
+
+static u32 *ipsec_itf_index_by_sw_if_index;
+
+static ipsec_itf_t *
+ipsec_itf_find_by_sw_if_index (u32 sw_if_index)
+{
+  if (vec_len (ipsec_itf_index_by_sw_if_index) <= sw_if_index)
+    return NULL;
+  u32 ti = ipsec_itf_index_by_sw_if_index[sw_if_index];
+  if (ti == ~0)
+    return NULL;
+  return pool_elt_at_index (ipsec_itf_pool, ti);
+}
+
+static u8 *
+format_ipsec_itf_name (u8 * s, va_list * args)
+{
+  u32 dev_instance = va_arg (*args, u32);
+  return format (s, "ipsec%d", dev_instance);
+}
+
+void
+ipsec_itf_adj_unstack (adj_index_t ai)
+{
+  adj_midchain_delegate_unstack (ai);
+}
+
+void
+ipsec_itf_adj_stack (adj_index_t ai, u32 sai)
+{
+  const vnet_hw_interface_t *hw;
+
+  hw = vnet_get_sup_hw_interface (vnet_get_main (), adj_get_sw_if_index (ai));
+
+  if (hw->flags & VNET_HW_INTERFACE_FLAG_LINK_UP)
+    {
+      const ipsec_sa_t *sa;
+
+      sa = ipsec_sa_get (sai);
+
+      /* *INDENT-OFF* */
+      const fib_prefix_t dst = {
+        .fp_len = (ipsec_sa_is_set_IS_TUNNEL_V6(sa) ? 128 : 32),
+        .fp_proto = (ipsec_sa_is_set_IS_TUNNEL_V6(sa)?
+                     FIB_PROTOCOL_IP6 :
+                     FIB_PROTOCOL_IP4),
+        .fp_addr = sa->tunnel_dst_addr,
+      };
+      /* *INDENT-ON* */
+
+      adj_midchain_delegate_stack (ai, 0, &dst);
+    }
+  else
+    adj_midchain_delegate_unstack (ai);
+}
+
+static adj_walk_rc_t
+ipsec_itf_adj_stack_cb (adj_index_t ai, void *arg)
+{
+  ipsec_tun_protect_t *itp = arg;
+
+  ipsec_itf_adj_stack (ai, itp->itp_out_sa);
+
+  return (ADJ_WALK_RC_CONTINUE);
+}
+
+static void
+ipsec_itf_restack (index_t itpi, const ipsec_itf_t * itf)
+{
+  ipsec_tun_protect_t *itp;
+  fib_protocol_t proto;
+
+  itp = ipsec_tun_protect_get (itpi);
+
+  /*
+   * walk all the adjacencies on the interface and restack them
+   */
+  FOR_EACH_FIB_IP_PROTOCOL (proto)
+  {
+    adj_nbr_walk (itf->ii_sw_if_index, proto, ipsec_itf_adj_stack_cb, itp);
+  }
+}
+
+static walk_rc_t
+ipsec_tun_protect_walk_state_change (index_t itpi, void *arg)
+{
+  const ipsec_itf_t *itf = arg;
+
+  ipsec_itf_restack (itpi, itf);
+
+  return (WALK_CONTINUE);
+}
+
+static clib_error_t *
+ipsec_itf_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
+{
+  vnet_hw_interface_t *hi;
+  ipsec_itf_t *itf;
+  u32 hw_flags;
+
+  hi = vnet_get_hw_interface (vnm, hw_if_index);
+  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);
+
+  itf = ipsec_itf_find_by_sw_if_index (hi->sw_if_index);
+
+  if (itf)
+    ipsec_tun_protect_walk_itf (itf->ii_sw_if_index,
+				ipsec_tun_protect_walk_state_change, itf);
+
+  return (NULL);
+}
+
+static int
+ipsec_itf_tunnel_desc (u32 sw_if_index,
+		       ip46_address_t * src, ip46_address_t * dst, u8 * is_l2)
+{
+  ip46_address_reset (src);
+  ip46_address_reset (dst);
+  *is_l2 = 0;
+
+  return (0);
+}
+
+static u8 *
+ipsec_itf_build_rewrite (void)
+{
+  /*
+   * passing the adj code a NULL rewrite means 'i don't have one cos
+   * t'other end is unresolved'. That's not the case here. For the ipsec
+   * tunnel there are just no bytes of encap to apply in the adj.
+   * So return a zero length rewrite. Encap will be added by a tunnel mode SA.
+   */
+  u8 *rewrite = NULL;
+
+  vec_validate (rewrite, 0);
+  vec_reset_length (rewrite);
+
+  return (rewrite);
+}
+
+static u8 *
+ipsec_itf_build_rewrite_i (vnet_main_t * vnm,
+			   u32 sw_if_index,
+			   vnet_link_t link_type, const void *dst_address)
+{
+  return (ipsec_itf_build_rewrite ());
+}
+
+void
+ipsec_itf_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
+{
+  adj_nbr_midchain_update_rewrite
+    (ai, NULL, NULL, ADJ_FLAG_MIDCHAIN_IP_STACK, ipsec_itf_build_rewrite ());
+}
+
+/* *INDENT-OFF* */
+VNET_DEVICE_CLASS (ipsec_itf_device_class) = {
+  .name = "IPSEC Tunnel",
+  .format_device_name = format_ipsec_itf_name,
+  .admin_up_down_function = ipsec_itf_admin_up_down,
+  .ip_tun_desc = ipsec_itf_tunnel_desc,
+};
+
+VNET_HW_INTERFACE_CLASS(ipsec_hw_interface_class) = {
+  .name = "IPSec",
+  .build_rewrite = ipsec_itf_build_rewrite_i,
+  .update_adjacency = ipsec_itf_update_adj,
+  .flags = VNET_HW_INTERFACE_CLASS_FLAG_P2P,
+};
+/* *INDENT-ON* */
+
+/*
+ * Maintain a bitmap of allocated ipsec_itf instance numbers.
+ */
+#define IPSEC_ITF_MAX_INSTANCE		(16 * 1024)
+
+static u32
+ipsec_itf_instance_alloc (u32 want)
+{
+  /*
+   * Check for dynamically allocated instance number.
+   */
+  if (~0 == want)
+    {
+      u32 bit;
+
+      bit = clib_bitmap_first_clear (ipsec_itf_instances);
+      if (bit >= IPSEC_ITF_MAX_INSTANCE)
+	{
+	  return ~0;
+	}
+      ipsec_itf_instances = clib_bitmap_set (ipsec_itf_instances, bit, 1);
+      return bit;
+    }
+
+  /*
+   * In range?
+   */
+  if (want >= IPSEC_ITF_MAX_INSTANCE)
+    {
+      return ~0;
+    }
+
+  /*
+   * Already in use?
+   */
+  if (clib_bitmap_get (ipsec_itf_instances, want))
+    {
+      return ~0;
+    }
+
+  /*
+   * Grant allocation request.
+   */
+  ipsec_itf_instances = clib_bitmap_set (ipsec_itf_instances, want, 1);
+
+  return want;
+}
+
+static int
+ipsec_itf_instance_free (u32 instance)
+{
+  if (instance >= IPSEC_ITF_MAX_INSTANCE)
+    {
+      return -1;
+    }
+
+  if (clib_bitmap_get (ipsec_itf_instances, instance) == 0)
+    {
+      return -1;
+    }
+
+  ipsec_itf_instances = clib_bitmap_set (ipsec_itf_instances, instance, 0);
+  return 0;
+}
+
+int
+ipsec_itf_create (u32 user_instance, tunnel_mode_t mode, u32 * sw_if_indexp)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  u32 instance, hw_if_index;
+  vnet_hw_interface_t *hi;
+  ipsec_itf_t *ipsec_itf;
+
+  ASSERT (sw_if_indexp);
+
+  *sw_if_indexp = (u32) ~ 0;
+
+  if (mode != TUNNEL_MODE_P2P)
+    return VNET_API_ERROR_UNSUPPORTED;
+
+  /*
+   * Allocate a ipsec_itf instance.  Either select on dynamically
+   * or try to use the desired user_instance number.
+   */
+  instance = ipsec_itf_instance_alloc (user_instance);
+  if (instance == ~0)
+    return VNET_API_ERROR_INVALID_REGISTRATION;
+
+  pool_get (ipsec_itf_pool, ipsec_itf);
+
+  /* tunnel index (or instance) */
+  u32 t_idx = ipsec_itf - ipsec_itf_pool;
+
+  ipsec_itf->ii_mode = mode;
+  ipsec_itf->ii_user_instance = instance;
+  if (~0 == ipsec_itf->ii_user_instance)
+    ipsec_itf->ii_user_instance = t_idx;
+
+  hw_if_index = vnet_register_interface (vnm,
+					 ipsec_itf_device_class.index,
+					 t_idx,
+					 ipsec_hw_interface_class.index,
+					 t_idx);
+
+  hi = vnet_get_hw_interface (vnm, hw_if_index);
+
+  vec_validate_init_empty (ipsec_itf_index_by_sw_if_index, hi->sw_if_index,
+			   INDEX_INVALID);
+  ipsec_itf_index_by_sw_if_index[hi->sw_if_index] = t_idx;
+
+  ipsec_itf->ii_sw_if_index = *sw_if_indexp = hi->sw_if_index;
+
+  return 0;
+}
+
+int
+ipsec_itf_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 != ipsec_itf_device_class.index)
+    return VNET_API_ERROR_INVALID_SW_IF_INDEX;
+
+  ipsec_itf_t *ipsec_itf;
+  ipsec_itf = ipsec_itf_find_by_sw_if_index (sw_if_index);
+  if (NULL == ipsec_itf)
+    return VNET_API_ERROR_INVALID_SW_IF_INDEX;
+
+  if (ipsec_itf_instance_free (hw->dev_instance) < 0)
+    return VNET_API_ERROR_INVALID_SW_IF_INDEX;
+
+  vnet_delete_hw_interface (vnm, hw->hw_if_index);
+  pool_put (ipsec_itf_pool, ipsec_itf);
+
+  return 0;
+}
+
+static clib_error_t *
+ipsec_itf_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, "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 = ipsec_itf_create (instance, TUNNEL_MODE_P2P, &sw_if_index);
+
+  if (rv)
+    return clib_error_return (0, "iPSec interface create failed");
+
+  vlib_cli_output (vm, "%U\n", format_vnet_sw_if_index_name, vnet_get_main (),
+		   sw_if_index);
+  return 0;
+}
+
+/*?
+ * Create a IPSec interface.
+ *
+ * @cliexpar
+ * The following two command syntaxes are equivalent:
+ * @cliexcmd{ipsec itf create [instance <instance>]}
+ * Example of how to create a ipsec interface:
+ * @cliexcmd{ipsec itf create}
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (ipsec_itf_create_command, static) = {
+  .path = "ipsec itf create",
+  .short_help = "ipsec itf create [instance <instance>]",
+  .function = ipsec_itf_create_cli,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+ipsec_itf_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 = ipsec_itf_delete (sw_if_index);
+
+      if (rv)
+	return clib_error_return (0, "ipsec interface delete failed");
+    }
+  else
+    return clib_error_return (0, "no such interface: %U",
+			      format_unformat_error, input);
+
+  return 0;
+}
+
+/*?
+ * Delete a IPSEC_ITF interface.
+ *
+ * @cliexpar
+ * The following two command syntaxes are equivalent:
+ * @cliexcmd{ipsec itf delete <interface>}
+ * Example of how to create a ipsec_itf interface:
+ * @cliexcmd{ipsec itf delete ipsec0}
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (ipsec_itf_delete_command, static) = {
+  .path = "ipsec itf delete",
+  .short_help = "ipsec itf delete <interface>",
+  .function = ipsec_itf_delete_cli,
+};
+/* *INDENT-ON* */
+
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */