IPIP: Add IP{v4,v6} over IP{v4,v6} configured tunnel support.

Change-Id: I166301c9e2388bae5f70ec0179d663a2703e27f5
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 519 insertions, 0 deletions

diff --git a/src/vnet/ipip/sixrd.c b/src/vnet/ipip/sixrd.c
new file mode 100644
index 00000000000..c44c8345e30
--- /dev/null
+++ b/src/vnet/ipip/sixrd.c
@@ -0,0 +1,519 @@
+/*
+ * sixrd.c - 6RD specific functions (RFC5969)
+ *
+ * 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.
+ */
+
+/**
+ * This code supports the following sixrd modes:
+ *
+ * 32 EA bits (Complete IPv4 address is embedded):
+ *   ea_bits_len = 32
+ * IPv4 suffix is embedded:
+ *   ea_bits_len = < 32
+ * No embedded address bits (1:1 mode):
+ *   ea_bits_len = 0
+ */
+
+#include "ipip.h"
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+#include <vnet/adj/adj.h>
+#include <vnet/adj/adj_delegate.h>
+#include <vnet/adj/adj_midchain.h>
+#include <vnet/dpo/lookup_dpo.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/fib/ip6_fib.h>
+#include <vnet/plugin/plugin.h>
+#include <vpp/app/version.h>	// Really needed?
+
+extern vlib_node_registration_t ip4_sixrd_node;
+
+/**
+ * Adj delegate data
+ */
+typedef struct sixrd_adj_delegate_t_
+{
+  u32 adj_index;
+  fib_node_t sixrd_node;
+  fib_node_index_t sixrd_fib_entry_index;
+  u32 sixrd_sibling;
+} sixrd_adj_delegate_t;
+
+/**
+ * Pool of delegate structs
+ */
+static sixrd_adj_delegate_t *sixrd_adj_delegate_pool;
+
+/**
+ * Adj delegate registered type
+ */
+static adj_delegate_type_t sixrd_adj_delegate_type;
+
+/**
+ * FIB node registered type
+ */
+static fib_node_type_t sixrd_fib_node_type;
+
+static inline sixrd_adj_delegate_t *
+sixrd_adj_from_base (adj_delegate_t * ad)
+{
+  if (ad == NULL)
+    return (NULL);
+  return (pool_elt_at_index (sixrd_adj_delegate_pool, ad->ad_index));
+}
+
+static inline const sixrd_adj_delegate_t *
+sixrd_adj_from_const_base (const adj_delegate_t * ad)
+{
+  if (ad == NULL)
+    {
+      return (NULL);
+    }
+  return (pool_elt_at_index (sixrd_adj_delegate_pool, ad->ad_index));
+}
+
+static void
+sixrd_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b0,
+	     const void *data)
+{
+  ip4_header_t *ip4 = vlib_buffer_get_current (b0);
+  ip6_header_t *ip6 = vlib_buffer_get_current (b0) + sizeof (ip4_header_t);
+  const ipip_tunnel_t *t = data;
+
+  ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
+  ip4->dst_address.as_u32 =
+    sixrd_get_addr_net (t, ip6->dst_address.as_u64[0]);
+  ip4->checksum = ip4_header_checksum (ip4);
+}
+
+static void
+ip6ip_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b0,
+	     const void *data)
+{
+  const ipip_tunnel_t *t = data;
+  ip4_header_t *ip4 = vlib_buffer_get_current (b0);
+  ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
+  ip4->dst_address.as_u32 =
+    sixrd_get_addr_net (t, adj->sub_type.nbr.next_hop.as_u64[0]);
+  ip4->checksum = ip4_header_checksum (ip4);
+}
+
+static u8 *
+sixrd_build_rewrite (vnet_main_t * vnm, u32 sw_if_index,
+		     vnet_link_t link_type, const void *dst_address)
+{
+  u8 *rewrite = NULL;
+  ipip_tunnel_t *t;
+
+  t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
+  if (!t)
+    return 0;
+
+  vec_validate (rewrite, sizeof (ip4_header_t) - 1);
+  ip4_header_t *ip4 = (ip4_header_t *) rewrite;
+  ip4->ip_version_and_header_length = 0x45;
+  ip4->ttl = 64;
+  ip4->protocol = IP_PROTOCOL_IPV6;
+  /* fixup ip4 header length and checksum after-the-fact */
+  ip4->src_address.as_u32 = t->tunnel_src.ip4.as_u32;
+  ip4->dst_address.as_u32 = 0;
+  ip4->checksum = ip4_header_checksum (ip4);
+
+  return rewrite;
+}
+
+static void
+ip6ip_tunnel_stack (adj_index_t ai, u32 fib_entry_index)
+{
+  ip_adjacency_t *adj = adj_get (ai);
+  ipip_tunnel_t *t;
+  u32 sw_if_index = adj->rewrite_header.sw_if_index;
+
+  t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
+  if (!t)
+    return;
+
+  /*
+   * find the adjacency that is contributed by the FIB entry
+   * that this tunnel resolves via, and use it as the next adj
+   * in the midchain
+   */
+  if (vnet_hw_interface_get_flags (vnet_get_main (), t->hw_if_index) &
+      VNET_HW_INTERFACE_FLAG_LINK_UP)
+    {
+      adj_nbr_midchain_stack (ai,
+			      fib_entry_contribute_ip_forwarding
+			      (fib_entry_index));
+    }
+  else
+    {
+      adj_nbr_midchain_unstack (ai);
+    }
+}
+
+static void
+sixrd_tunnel_stack (adj_index_t ai, u32 fib_index)
+{
+  dpo_id_t dpo = DPO_INVALID;
+  ip_adjacency_t *adj = adj_get (ai);
+  u32 sw_if_index = adj->rewrite_header.sw_if_index;
+
+  ipip_tunnel_t *t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
+  if (!t)
+    return;
+
+  lookup_dpo_add_or_lock_w_fib_index (fib_index, DPO_PROTO_IP4,
+				      LOOKUP_UNICAST, LOOKUP_INPUT_DST_ADDR,
+				      LOOKUP_TABLE_FROM_CONFIG, &dpo);
+  adj_nbr_midchain_stack (ai, &dpo);
+}
+
+const static ip46_address_t sixrd_special_nh = {
+  .ip6 = {
+	  .as_u64 = {
+		     [0] = 0xffffffffffffffff,
+		     [1] = 0xffffffffffffffff,
+		     },
+	  },
+};
+
+static void
+sixrd_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
+{
+  ip_adjacency_t *adj = adj_get (ai);
+  ipip_tunnel_t *t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
+
+  if (!memcmp (&sixrd_special_nh, &adj->sub_type.nbr.next_hop,
+	       sizeof (sixrd_special_nh)))
+    {
+      adj_nbr_midchain_update_rewrite (ai, sixrd_fixup, t, ADJ_FLAG_NONE,
+				       sixrd_build_rewrite (vnm, sw_if_index,
+							    adj_get_link_type
+							    (ai), NULL));
+      sixrd_tunnel_stack (ai, t->fib_index);
+    }
+  else
+    {
+      sixrd_adj_delegate_t *sixrd_ad;
+      ip4_address_t da4;
+
+      da4.as_u32 =
+	sixrd_get_addr_net (t, adj->sub_type.nbr.next_hop.as_u64[0]);
+
+      fib_prefix_t pfx = {
+	.fp_proto = FIB_PROTOCOL_IP4,
+	.fp_len = 32,
+	.fp_addr = {
+		    .ip4 = da4,
+		    }
+	,
+      };
+
+      adj_nbr_midchain_update_rewrite (ai, ip6ip_fixup, t, ADJ_FLAG_NONE,
+				       sixrd_build_rewrite (vnm, sw_if_index,
+							    adj_get_link_type
+							    (ai), NULL));
+
+      sixrd_ad =
+	sixrd_adj_from_base (adj_delegate_get (adj, sixrd_adj_delegate_type));
+      if (sixrd_ad == NULL)
+	{
+	  pool_get (sixrd_adj_delegate_pool, sixrd_ad);
+	  fib_node_init (&sixrd_ad->sixrd_node, sixrd_fib_node_type);
+	  sixrd_ad->adj_index = ai;
+	  sixrd_ad->sixrd_fib_entry_index =
+	    fib_table_entry_special_add (t->fib_index, &pfx, FIB_SOURCE_RR,
+					 FIB_ENTRY_FLAG_NONE);
+	  sixrd_ad->sixrd_sibling =
+	    fib_entry_child_add (sixrd_ad->sixrd_fib_entry_index,
+				 sixrd_fib_node_type,
+				 sixrd_ad - sixrd_adj_delegate_pool);
+
+	  adj_delegate_add (adj, sixrd_adj_delegate_type,
+			    sixrd_ad - sixrd_adj_delegate_pool);
+
+	  ip6ip_tunnel_stack (ai, sixrd_ad->sixrd_fib_entry_index);
+	}
+    }
+}
+
+clib_error_t *
+sixrd_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
+{
+  /* Always up */
+  vnet_hw_interface_set_flags (vnm, hw_if_index,
+			       VNET_HW_INTERFACE_FLAG_LINK_UP);
+  return /* no error */ 0;
+}
+
+/* *INDENT-OFF* */
+VNET_HW_INTERFACE_CLASS(sixrd_hw_interface_class) = {
+    .name = "ip6ip-6rd",
+    .build_rewrite = sixrd_build_rewrite,
+    .update_adjacency = sixrd_update_adj,
+};
+
+VNET_DEVICE_CLASS(sixrd_device_class) = {
+    .name = "ip6ip-6rd",
+    .admin_up_down_function = sixrd_interface_admin_up_down,
+#ifdef SOON
+    .clear counter = 0;
+#endif
+}
+;
+/* *INDENT-ON* */
+
+int
+sixrd_add_tunnel (ip6_address_t * ip6_prefix, u8 ip6_prefix_len,
+		  ip4_address_t * ip4_prefix, u8 ip4_prefix_len,
+		  ip4_address_t * ip4_src, bool security_check,
+		  u32 fib_index, u32 * sw_if_index)
+{
+  ipip_main_t *gm = &ipip_main;
+  ipip_tunnel_t *t;
+
+  if (fib_index == ~0)
+    return VNET_API_ERROR_NO_SUCH_FIB;
+
+  if ((ip6_prefix_len + 32 - ip4_prefix_len) > 64)
+    return VNET_API_ERROR_INVALID_VALUE;
+
+  /* Tunnel already configured */
+  ip46_address_t src = ip46_address_initializer, dst =
+    ip46_address_initializer;
+  ip_set (&src, ip4_src, true);
+  ipip_tunnel_key_t key = {.transport = IPIP_TRANSPORT_IP4,
+    .fib_index = fib_index,
+    .src = src,
+    .dst = dst
+  };
+
+  t = ipip_tunnel_db_find (&key);
+  if (t)
+    return VNET_API_ERROR_IF_ALREADY_EXISTS;
+
+  /* Get tunnel index */
+  pool_get_aligned (gm->tunnels, t, CLIB_CACHE_LINE_BYTES);
+  memset (t, 0, sizeof (*t));
+  u32 t_idx = t - gm->tunnels;	/* tunnel index (or instance) */
+
+  /* Init tunnel struct */
+  t->mode = IPIP_MODE_6RD;
+  t->sixrd.ip4_prefix.as_u32 = ip4_prefix->as_u32;
+  t->sixrd.ip4_prefix_len = ip4_prefix_len;
+  t->sixrd.ip6_prefix = *ip6_prefix;
+  t->sixrd.ip6_prefix_len = ip6_prefix_len;
+  t->tunnel_src = src;
+  t->sixrd.security_check = security_check;
+  t->sixrd.shift =
+    (ip4_prefix_len < 32) ? 64 - ip6_prefix_len - (32 - ip4_prefix_len) : 0;
+
+  /* Create interface */
+  u32 hw_if_index =
+    vnet_register_interface (vnet_get_main (), sixrd_device_class.index,
+			     t_idx,
+			     sixrd_hw_interface_class.index, t_idx);
+
+  /* Default the interface to up and enable IPv6 (payload) */
+  vnet_hw_interface_t *hi =
+    vnet_get_hw_interface (vnet_get_main (), hw_if_index);
+  t->hw_if_index = hw_if_index;
+  t->fib_index = fib_index;
+  t->sw_if_index = hi->sw_if_index;
+  t->dev_instance = t_idx;
+  t->user_instance = t_idx;
+
+  hi->max_l3_packet_bytes[VLIB_RX] = hi->max_l3_packet_bytes[VLIB_TX] = 1480;
+
+  ipip_tunnel_db_add (t, &key);
+
+  vec_validate_init_empty (gm->tunnel_index_by_sw_if_index, hi->sw_if_index,
+			   ~0);
+  gm->tunnel_index_by_sw_if_index[hi->sw_if_index] = t_idx;
+
+  vnet_hw_interface_set_flags (vnet_get_main (), hw_if_index,
+			       VNET_HW_INTERFACE_FLAG_LINK_UP);
+  vnet_sw_interface_set_flags (vnet_get_main (), hi->sw_if_index,
+			       VNET_SW_INTERFACE_FLAG_ADMIN_UP);
+  ip6_sw_interface_enable_disable (hi->sw_if_index, true);
+
+  /* Create IPv6 route/adjacency */
+  fib_prefix_t pfx6 = {
+    .fp_proto = FIB_PROTOCOL_IP6,
+    .fp_len = t->sixrd.ip6_prefix_len,
+    .fp_addr = {
+		.ip6 = t->sixrd.ip6_prefix,
+		}
+    ,
+  };
+
+  fib_table_entry_update_one_path (fib_index, &pfx6, FIB_SOURCE_CLI,
+				   FIB_ENTRY_FLAG_ATTACHED, DPO_PROTO_IP6,
+				   &sixrd_special_nh, hi->sw_if_index, ~0, 1,
+				   NULL, FIB_ROUTE_PATH_FLAG_NONE);
+
+  *sw_if_index = hi->sw_if_index;
+
+  if (!gm->ip4_protocol_registered)
+    {
+      vlib_node_t *ipip4_input =
+	vlib_get_node_by_name (gm->vlib_main, (u8 *) "ipip4-input");
+      ASSERT (ipip4_input);
+      ip4_register_protocol (IP_PROTOCOL_IPV6, ipip4_input->index);
+    }
+  return 0;
+}
+
+/*
+ * sixrd_del_tunnel
+ */
+int
+sixrd_del_tunnel (u32 sw_if_index)
+{
+  ipip_main_t *gm = &ipip_main;
+  ipip_tunnel_t *t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
+
+  if (!t)
+    {
+      clib_warning ("SIXRD tunnel delete: tunnel does not exist: %d",
+		    sw_if_index);
+      return -1;
+    }
+
+  fib_prefix_t pfx6 = {
+    .fp_proto = FIB_PROTOCOL_IP6,
+    .fp_len = t->sixrd.ip6_prefix_len,
+    .fp_addr = {
+		.ip6 = t->sixrd.ip6_prefix,
+		}
+    ,
+  };
+  fib_table_entry_special_remove (0, &pfx6, FIB_SOURCE_CLI);
+  vnet_sw_interface_set_flags (vnet_get_main (), t->sw_if_index,
+			       0 /* down */ );
+  ip6_sw_interface_enable_disable (t->sw_if_index, false);
+  gm->tunnel_index_by_sw_if_index[t->sw_if_index] = ~0;
+
+  vnet_delete_hw_interface (vnet_get_main (), t->hw_if_index);
+  ipip_tunnel_db_remove (t);
+  pool_put (gm->tunnels, t);
+
+  return 0;
+}
+
+static void
+sixrd_adj_delegate_adj_deleted (adj_delegate_t * aed)
+{
+  sixrd_adj_delegate_t *sixrd_ad;
+
+  sixrd_ad = sixrd_adj_from_base (aed);
+  fib_entry_child_remove (sixrd_ad->sixrd_fib_entry_index,
+			  sixrd_ad->sixrd_sibling);
+  fib_table_entry_delete_index (sixrd_ad->sixrd_fib_entry_index,
+				FIB_SOURCE_RR);
+  pool_put (sixrd_adj_delegate_pool, sixrd_ad);
+}
+
+static u8 *
+sixrd_adj_delegate_format (const adj_delegate_t * aed, u8 * s)
+{
+  const sixrd_adj_delegate_t *sixrd_ad;
+
+  sixrd_ad = sixrd_adj_from_const_base (aed);
+  s = format (s, "SIXRD:[fib-entry:%d]", sixrd_ad->sixrd_fib_entry_index);
+
+  return (s);
+}
+
+static void
+sixrd_fib_node_last_lock_gone (fib_node_t * node)
+{
+  /* top of the dependency tree, locks not managed here. */
+}
+
+static sixrd_adj_delegate_t *
+sixrd_adj_delegate_from_fib_node (fib_node_t * node)
+{
+  return ((sixrd_adj_delegate_t *) (((char *) node) -
+				    STRUCT_OFFSET_OF (sixrd_adj_delegate_t,
+						      sixrd_node)));
+}
+
+static fib_node_back_walk_rc_t
+sixrd_fib_node_back_walk_notify (fib_node_t * node,
+				 fib_node_back_walk_ctx_t * ctx)
+{
+  sixrd_adj_delegate_t *sixrd_ad;
+
+  sixrd_ad = sixrd_adj_delegate_from_fib_node (node);
+  ip6ip_tunnel_stack (sixrd_ad->adj_index, sixrd_ad->sixrd_fib_entry_index);
+
+  return (FIB_NODE_BACK_WALK_CONTINUE);
+}
+
+/**
+ * Function definition to get a FIB node from its index
+ */
+static fib_node_t *
+sixrd_fib_node_get (fib_node_index_t index)
+{
+  sixrd_adj_delegate_t *sixrd_ad;
+
+  sixrd_ad = pool_elt_at_index (sixrd_adj_delegate_pool, index);
+
+  return (&sixrd_ad->sixrd_node);
+}
+
+/**
+ * VFT registered with the adjacency delegate
+ */
+const static adj_delegate_vft_t sixrd_adj_delegate_vft = {
+  .adv_adj_deleted = sixrd_adj_delegate_adj_deleted,
+  .adv_format = sixrd_adj_delegate_format,
+};
+
+/**
+ * VFT registered with the FIB node for the adj delegate
+ */
+const static fib_node_vft_t sixrd_fib_node_vft = {
+  .fnv_get = sixrd_fib_node_get,
+  .fnv_last_lock = sixrd_fib_node_last_lock_gone,
+  .fnv_back_walk = sixrd_fib_node_back_walk_notify,
+};
+
+static clib_error_t *
+sixrd_init (vlib_main_t * vm)
+{
+  clib_error_t *error = 0;
+
+  /* Make sure the IPIP tunnel subsystem is initialised */
+  vlib_call_init_function (vm, ipip_init);
+
+  sixrd_adj_delegate_type =
+    adj_delegate_register_new_type (&sixrd_adj_delegate_vft);
+  sixrd_fib_node_type = fib_node_register_new_type (&sixrd_fib_node_vft);
+
+  return error;
+}
+
+VLIB_INIT_FUNCTION (sixrd_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */