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, 566 insertions, 0 deletions

diff --git a/src/vnet/ipip/ipip.c b/src/vnet/ipip/ipip.c
new file mode 100644
index 00000000000..82c961cdddd
--- /dev/null
+++ b/src/vnet/ipip/ipip.c
@@ -0,0 +1,566 @@
+/*
+ * ipip.c: ipip
+ *
+ * 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 aipiped 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 <stddef.h>
+#include <vnet/adj/adj_midchain.h>
+#include <vnet/ipip/ipip.h>
+#include <vnet/vnet.h>
+#include <vnet/adj/adj_nbr.h>
+#include <vnet/fib/ip4_fib.h>
+#include <vnet/fib/ip6_fib.h>
+#include <vnet/ip/format.h>
+#include <vnet/ipip/ipip.h>
+
+ipip_main_t ipip_main;
+
+/* Packet trace structure */
+typedef struct
+{
+  u32 tunnel_id;
+  u32 length;
+  ip46_address_t src;
+  ip46_address_t dst;
+} ipip_tx_trace_t;
+
+u8 *
+format_ipip_tx_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  ipip_tx_trace_t *t = va_arg (*args, ipip_tx_trace_t *);
+
+  s =
+    format (s, "IPIP: tunnel %d len %d src %U dst %U", t->tunnel_id,
+	    t->length, format_ip46_address, &t->src, IP46_TYPE_ANY,
+	    format_ip46_address, &t->dst, IP46_TYPE_ANY);
+  return s;
+}
+
+static u8 *
+ipip_build_rewrite (vnet_main_t * vnm, u32 sw_if_index,
+		    vnet_link_t link_type, const void *dst_address)
+{
+  ip4_header_t *ip4;
+  ip6_header_t *ip6;
+  u8 *rewrite = NULL;
+  ipip_tunnel_t *t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
+
+  if (!t)
+    /* not one of ours */
+    return (0);
+
+  switch (t->transport)
+    {
+    case IPIP_TRANSPORT_IP4:
+      vec_validate (rewrite, sizeof (*ip4) - 1);
+      ip4 = (ip4_header_t *) rewrite;
+      ip4->ip_version_and_header_length = 0x45;
+      ip4->ttl = 64;
+      /* fixup ip4 header length, protocol and checksum after-the-fact */
+      ip4->src_address.as_u32 = t->tunnel_src.ip4.as_u32;
+      ip4->dst_address.as_u32 = t->tunnel_dst.ip4.as_u32;
+      ip4->checksum = ip4_header_checksum (ip4);
+      break;
+
+    case IPIP_TRANSPORT_IP6:
+      vec_validate (rewrite, sizeof (*ip6) - 1);
+      ip6 = (ip6_header_t *) rewrite;
+      ip6->ip_version_traffic_class_and_flow_label =
+	clib_host_to_net_u32 (6 << 28);
+      ip6->hop_limit = 64;
+      /* fixup ip6 header length and protocol after-the-fact */
+      ip6->src_address.as_u64[0] = t->tunnel_src.ip6.as_u64[0];
+      ip6->src_address.as_u64[1] = t->tunnel_src.ip6.as_u64[1];
+      ip6->dst_address.as_u64[0] = t->tunnel_dst.ip6.as_u64[0];
+      ip6->dst_address.as_u64[1] = t->tunnel_dst.ip6.as_u64[1];
+      break;
+    default:
+      /* pass through */
+      ;
+    }
+  return (rewrite);
+}
+
+static void
+ipip4_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b,
+	     const void *data)
+{
+  ip4_header_t *ip4;
+
+  ip4 = vlib_buffer_get_current (b);
+  ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b));
+  ip4->protocol =
+    adj->ia_link == VNET_LINK_IP6 ? IP_PROTOCOL_IPV6 : IP_PROTOCOL_IP_IN_IP;
+  ip4->checksum = ip4_header_checksum (ip4);
+}
+
+static void
+ipip6_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b,
+	     const void *data)
+{
+  ip6_header_t *ip6;
+
+  ip6 = vlib_buffer_get_current (b);
+  ip6->payload_length =
+    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b) -
+			  sizeof (*ip6));
+  ip6->protocol =
+    adj->ia_link == VNET_LINK_IP6 ? IP_PROTOCOL_IPV6 : IP_PROTOCOL_IP_IN_IP;
+}
+
+static void
+ipip_tunnel_stack (adj_index_t ai)
+{
+  ip_adjacency_t *adj;
+  ipip_tunnel_t *t;
+  u32 sw_if_index;
+
+  adj = adj_get (ai);
+  sw_if_index = adj->rewrite_header.sw_if_index;
+
+  t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
+  if (!t)
+    return;
+
+  if ((vnet_hw_interface_get_flags (vnet_get_main (), t->hw_if_index) &
+       VNET_HW_INTERFACE_FLAG_LINK_UP) == 0)
+    {
+      adj_nbr_midchain_unstack (ai);
+      return;
+    }
+
+  dpo_id_t tmp = DPO_INVALID;
+  fib_forward_chain_type_t fib_fwd =
+    t->transport ==
+    IPIP_TRANSPORT_IP6 ? FIB_FORW_CHAIN_TYPE_UNICAST_IP6 :
+    FIB_FORW_CHAIN_TYPE_UNICAST_IP4;
+
+  fib_entry_contribute_forwarding (t->p2p.fib_entry_index, fib_fwd, &tmp);
+  if (DPO_LOAD_BALANCE == tmp.dpoi_type)
+    {
+      /*
+       * post IPIP rewrite we will load-balance. However, the IPIP encap
+       * is always the same for this adjacency/tunnel and hence the IP/IPIP
+       * src,dst hash is always the same result too. So we do that hash now and
+       * stack on the choice.
+       * If the choice is an incomplete adj then we will need a poke when
+       * it becomes complete. This happens since the adj update walk propagates
+       * as far a recursive paths.
+       */
+      const dpo_id_t *choice;
+      load_balance_t *lb;
+      int hash;
+
+      lb = load_balance_get (tmp.dpoi_index);
+
+      if (fib_fwd == FIB_FORW_CHAIN_TYPE_UNICAST_IP4)
+	hash = ip4_compute_flow_hash ((ip4_header_t *) adj_get_rewrite (ai),
+				      lb->lb_hash_config);
+      else
+	hash = ip6_compute_flow_hash ((ip6_header_t *) adj_get_rewrite (ai),
+				      lb->lb_hash_config);
+      choice =
+	load_balance_get_bucket_i (lb, hash & lb->lb_n_buckets_minus_1);
+      dpo_copy (&tmp, choice);
+    }
+
+  adj_nbr_midchain_stack (ai, &tmp);
+  dpo_reset (&tmp);
+}
+
+static adj_walk_rc_t
+ipip_adj_walk_cb (adj_index_t ai, void *ctx)
+{
+  ipip_tunnel_stack (ai);
+
+  return (ADJ_WALK_RC_CONTINUE);
+}
+
+static void
+ipip_tunnel_restack (ipip_tunnel_t * gt)
+{
+  fib_protocol_t proto;
+
+  /*
+   * walk all the adjacencies on th IPIP interface and restack them
+   */
+  FOR_EACH_FIB_IP_PROTOCOL (proto)
+  {
+    adj_nbr_walk (gt->sw_if_index, proto, ipip_adj_walk_cb, NULL);
+  }
+}
+
+void
+ipip_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
+{
+  ipip_tunnel_t *t;
+  adj_midchain_fixup_t f;
+
+  t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
+  if (!t)
+    return;
+
+  f = t->transport == IPIP_TRANSPORT_IP6 ? ipip6_fixup : ipip4_fixup;
+
+  adj_nbr_midchain_update_rewrite (ai, f, NULL,
+				   (VNET_LINK_ETHERNET ==
+				    adj_get_link_type (ai) ?
+				    ADJ_FLAG_MIDCHAIN_NO_COUNT :
+				    ADJ_FLAG_NONE), ipip_build_rewrite (vnm,
+									sw_if_index,
+									adj_get_link_type
+									(ai),
+									NULL));
+  ipip_tunnel_stack (ai);
+}
+
+static u8 *
+format_ipip_tunnel_name (u8 * s, va_list * args)
+{
+  u32 dev_instance = va_arg (*args, u32);
+  ipip_main_t *gm = &ipip_main;
+  ipip_tunnel_t *t;
+
+  if (dev_instance >= vec_len (gm->tunnels))
+    return format (s, "<improperly-referenced>");
+
+  t = pool_elt_at_index (gm->tunnels, dev_instance);
+  return format (s, "ipip%d", t->user_instance);
+}
+
+static u8 *
+format_ipip_device (u8 * s, va_list * args)
+{
+  u32 dev_instance = va_arg (*args, u32);
+  CLIB_UNUSED (int verbose) = va_arg (*args, int);
+
+  s = format (s, "IPIP tunnel: id %d\n", dev_instance);
+  return s;
+}
+
+static clib_error_t *
+ipip_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
+{
+  vnet_hw_interface_t *hi;
+  ipip_tunnel_t *t;
+
+  hi = vnet_get_hw_interface (vnm, hw_if_index);
+
+  t = ipip_tunnel_db_find_by_sw_if_index (hi->sw_if_index);
+  if (!t)
+    return 0;
+
+  if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
+    vnet_hw_interface_set_flags (vnm, hw_if_index,
+				 VNET_HW_INTERFACE_FLAG_LINK_UP);
+  else
+    vnet_hw_interface_set_flags (vnm, hw_if_index, 0 /* down */ );
+
+  ipip_tunnel_restack (t);
+
+  return /* no error */ 0;
+}
+
+/* *INDENT-OFF* */
+VNET_DEVICE_CLASS(ipip_device_class) = {
+    .name = "IPIP tunnel device",
+    .format_device_name = format_ipip_tunnel_name,
+    .format_device = format_ipip_device,
+    .format_tx_trace = format_ipip_tx_trace,
+    .admin_up_down_function = ipip_interface_admin_up_down,
+#ifdef SOON
+    .clear counter = 0;
+#endif
+};
+
+VNET_HW_INTERFACE_CLASS(ipip_hw_interface_class) = {
+    .name = "IPIP",
+    //.format_header = format_ipip_header_with_length,
+    //.unformat_header = unformat_ipip_header,
+    .build_rewrite = ipip_build_rewrite,
+    .update_adjacency = ipip_update_adj,
+    .flags = VNET_HW_INTERFACE_CLASS_FLAG_P2P,
+};
+/* *INDENT-ON* */
+
+ipip_tunnel_t *
+ipip_tunnel_db_find (ipip_tunnel_key_t * key)
+{
+  ipip_main_t *gm = &ipip_main;
+  uword *p;
+
+  p = hash_get_mem (gm->tunnel_by_key, key);
+  if (!p)
+    return (NULL);
+  return (pool_elt_at_index (gm->tunnels, p[0]));
+}
+
+ipip_tunnel_t *
+ipip_tunnel_db_find_by_sw_if_index (u32 sw_if_index)
+{
+  ipip_main_t *gm = &ipip_main;
+  if (vec_len (gm->tunnel_index_by_sw_if_index) < sw_if_index)
+    return NULL;
+  u32 ti = gm->tunnel_index_by_sw_if_index[sw_if_index];
+  if (ti == ~0)
+    return NULL;
+  return pool_elt_at_index (gm->tunnels, ti);
+}
+
+void
+ipip_tunnel_db_add (ipip_tunnel_t * t, ipip_tunnel_key_t * key)
+{
+  ipip_main_t *gm = &ipip_main;
+
+  t->key = clib_mem_alloc (sizeof (*t->key));
+  clib_memcpy (t->key, key, sizeof (*key));
+  hash_set_mem (gm->tunnel_by_key, t->key, t->dev_instance);
+}
+
+void
+ipip_tunnel_db_remove (ipip_tunnel_t * t)
+{
+  ipip_main_t *gm = &ipip_main;
+
+  hash_unset_mem (gm->tunnel_by_key, t->key);
+  clib_mem_free (t->key);
+  t->key = NULL;
+}
+
+static ipip_tunnel_t *
+ipip_tunnel_from_fib_node (fib_node_t * node)
+{
+  ipip_main_t *gm = &ipip_main;
+  ASSERT (gm->fib_node_type == node->fn_type);
+  return ((ipip_tunnel_t *) (((char *) node) -
+			     offsetof (ipip_tunnel_t, p2p.node)));
+}
+
+static fib_node_back_walk_rc_t
+ipip_tunnel_back_walk (fib_node_t * node, fib_node_back_walk_ctx_t * ctx)
+{
+  ipip_tunnel_restack (ipip_tunnel_from_fib_node (node));
+
+  return (FIB_NODE_BACK_WALK_CONTINUE);
+}
+
+static fib_node_t *
+ipip_tunnel_fib_node_get (fib_node_index_t index)
+{
+  ipip_tunnel_t *gt;
+  ipip_main_t *gm;
+
+  gm = &ipip_main;
+  gt = pool_elt_at_index (gm->tunnels, index);
+
+  return (&gt->p2p.node);
+}
+
+static void
+ipip_tunnel_last_lock_gone (fib_node_t * node)
+{
+  /*
+   * The MPLS IPIP tunnel is a root of the graph. As such
+   * it never has children and thus is never locked.
+   */
+  ASSERT (0);
+}
+
+/*
+ * Virtual function table registered by IPIP tunnels
+ * for participation in the FIB object graph.
+ */
+const static fib_node_vft_t ipip_vft = {
+  .fnv_get = ipip_tunnel_fib_node_get,
+  .fnv_last_lock = ipip_tunnel_last_lock_gone,
+  .fnv_back_walk = ipip_tunnel_back_walk,
+};
+
+static void
+ipip_fib_add (ipip_tunnel_t * t)
+{
+  ipip_main_t *gm = &ipip_main;
+  fib_prefix_t dst = {.fp_len = t->transport == IPIP_TRANSPORT_IP6 ? 128 : 32,
+    .fp_proto =
+      t->transport ==
+      IPIP_TRANSPORT_IP6 ? FIB_PROTOCOL_IP6 : FIB_PROTOCOL_IP4,
+    .fp_addr = t->tunnel_dst
+  };
+
+  t->p2p.fib_entry_index =
+    fib_table_entry_special_add (t->fib_index, &dst, FIB_SOURCE_RR,
+				 FIB_ENTRY_FLAG_NONE);
+  t->p2p.sibling_index =
+    fib_entry_child_add (t->p2p.fib_entry_index, gm->fib_node_type,
+			 t->dev_instance);
+}
+
+static void
+ipip_fib_delete (ipip_tunnel_t * t)
+{
+  fib_entry_child_remove (t->p2p.fib_entry_index, t->p2p.sibling_index);
+  fib_table_entry_delete_index (t->p2p.fib_entry_index, FIB_SOURCE_RR);
+  fib_node_deinit (&t->p2p.node);
+}
+
+int
+ipip_add_tunnel (ipip_transport_t transport,
+		 u32 instance, ip46_address_t * src, ip46_address_t * dst,
+		 u32 fib_index, u32 * sw_if_indexp)
+{
+  ipip_main_t *gm = &ipip_main;
+  vnet_main_t *vnm = gm->vnet_main;
+  ip4_main_t *im4 = &ip4_main;
+  ip6_main_t *im6 = &ip6_main;
+  ipip_tunnel_t *t;
+  vnet_hw_interface_t *hi;
+  u32 hw_if_index, sw_if_index;
+  ipip_tunnel_key_t key = {.transport = transport,
+    .fib_index = fib_index,
+    .src = *src,
+    .dst = *dst
+  };
+  t = ipip_tunnel_db_find (&key);
+  if (t)
+    return VNET_API_ERROR_IF_ALREADY_EXISTS;
+
+  pool_get_aligned (gm->tunnels, t, CLIB_CACHE_LINE_BYTES);
+  memset (t, 0, sizeof (*t));
+
+  /* Reconcile the real dev_instance and a possible requested instance */
+  u32 t_idx = t - gm->tunnels;	/* tunnel index (or instance) */
+  u32 u_idx = instance;		/* user specified instance */
+  if (u_idx == ~0)
+    u_idx = t_idx;
+  if (hash_get (gm->instance_used, u_idx))
+    {
+      pool_put (gm->tunnels, t);
+      return VNET_API_ERROR_INSTANCE_IN_USE;
+    }
+  hash_set (gm->instance_used, u_idx, 1);
+
+  t->dev_instance = t_idx;	/* actual */
+  t->user_instance = u_idx;	/* name */
+  fib_node_init (&t->p2p.node, gm->fib_node_type);
+
+  hw_if_index = vnet_register_interface (vnm, ipip_device_class.index, t_idx,
+					 ipip_hw_interface_class.index,
+					 t_idx);
+
+  hi = vnet_get_hw_interface (vnm, hw_if_index);
+  sw_if_index = hi->sw_if_index;
+
+  t->hw_if_index = hw_if_index;
+  t->fib_index = fib_index;
+  t->sw_if_index = sw_if_index;
+
+  t->transport = transport;
+  vec_validate_init_empty (gm->tunnel_index_by_sw_if_index, sw_if_index, ~0);
+  gm->tunnel_index_by_sw_if_index[sw_if_index] = t_idx;
+
+  if (t->transport == IPIP_TRANSPORT_IP4)
+    {
+      vec_validate (im4->fib_index_by_sw_if_index, sw_if_index);
+      hi->min_packet_bytes = 64 + sizeof (ip4_header_t);
+    }
+  else
+    {
+      vec_validate (im6->fib_index_by_sw_if_index, sw_if_index);
+      hi->min_packet_bytes = 64 + sizeof (ip6_header_t);
+    }
+
+  hi->per_packet_overhead_bytes = /* preamble */ 8 + /* inter frame gap */ 12;
+
+  /* Standard default ipip MTU. */
+  hi->max_l3_packet_bytes[VLIB_RX] = hi->max_l3_packet_bytes[VLIB_TX] = 9000;
+
+  t->tunnel_src = *src;
+  t->tunnel_dst = *dst;
+
+  ipip_tunnel_db_add (t, &key);
+
+  /*
+   * Source the FIB entry for the tunnel's destination and become a
+   * child thereof. The tunnel will then get poked when the forwarding
+   * for the entry updates, and the tunnel can re-stack accordingly
+   */
+  ipip_fib_add (t);
+  if (sw_if_indexp)
+    *sw_if_indexp = sw_if_index;
+
+  if (t->transport == IPIP_TRANSPORT_IP6 && !gm->ip6_protocol_registered)
+    {
+      ip6_register_protocol (IP_PROTOCOL_IP_IN_IP, ipip6_input_node.index);
+      ip6_register_protocol (IP_PROTOCOL_IPV6, ipip6_input_node.index);
+      gm->ip6_protocol_registered = true;
+    }
+  else if (t->transport == IPIP_TRANSPORT_IP4 && !gm->ip4_protocol_registered)
+    {
+      ip4_register_protocol (IP_PROTOCOL_IP_IN_IP, ipip4_input_node.index);
+      ip4_register_protocol (IP_PROTOCOL_IPV6, ipip4_input_node.index);
+      gm->ip4_protocol_registered = true;
+    }
+  return 0;
+}
+
+int
+ipip_del_tunnel (u32 sw_if_index)
+{
+  ipip_main_t *gm = &ipip_main;
+  vnet_main_t *vnm = gm->vnet_main;
+  ipip_tunnel_t *t;
+
+
+  t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
+  if (t == NULL)
+    return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  vnet_sw_interface_set_flags (vnm, sw_if_index, 0 /* down */ );
+  gm->tunnel_index_by_sw_if_index[sw_if_index] = ~0;
+  vnet_delete_hw_interface (vnm, t->hw_if_index);
+  ipip_fib_delete (t);
+  hash_unset (gm->instance_used, t->user_instance);
+  ipip_tunnel_db_remove (t);
+  pool_put (gm->tunnels, t);
+
+  return 0;
+}
+
+static clib_error_t *
+ipip_init (vlib_main_t * vm)
+{
+  ipip_main_t *gm = &ipip_main;
+
+  memset (gm, 0, sizeof (gm[0]));
+  gm->vlib_main = vm;
+  gm->vnet_main = vnet_get_main ();
+  gm->tunnel_by_key =
+    hash_create_mem (0, sizeof (ipip_tunnel_key_t), sizeof (uword));
+  gm->fib_node_type = fib_node_register_new_type (&ipip_vft);
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (ipip_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */