text: /*
   * 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/adj/adj_midchain.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);
        if (t->tc_tos != 0xFF)
  	ip4->tos = t->tc_tos;
        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);
        if (t->tc_tos != 0xFF)
  	ip6_set_traffic_class_network_order (ip6, t->tc_tos);
        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;
    const ipip_tunnel_t *t = data;
  
    ip4 = vlib_buffer_get_current (b);
    ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b));
    switch (adj->ia_link)
      {
      case VNET_LINK_IP6:
        ip4->protocol = IP_PROTOCOL_IPV6;
        if (t->tc_tos == 0xFF)
  	ip4->tos =
  	  ip6_traffic_class_network_order ((const ip6_header_t *) (ip4 + 1));
        break;
  
      case VNET_LINK_IP4:
        ip4->protocol = IP_PROTOCOL_IP_IN_IP;
        if (t->tc_tos == 0xFF)
  	ip4->tos = ((ip4_header_t *) (ip4 + 1))->tos;
        break;
  
      default:
        break;
      }
  
    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;
    const ipip_tunnel_t *t = data;
  
    /* Must set locally originated otherwise we're not allowed to
       fragment the packet later */
    b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
  
    ip6 = vlib_buffer_get_current (b);
    ip6->payload_length =
      clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b) -
  			  sizeof (*ip6));
    switch (adj->ia_link)
      {
      case VNET_LINK_IP6:
        ip6->protocol = IP_PROTOCOL_IPV6;
        if (t->tc_tos == 0xFF)
  	ip6_set_traffic_class_network_order (ip6,
  					     ip6_traffic_class_network_order ((const ip6_header_t *) (ip6 + 1)));
        break;
  
      case VNET_LINK_IP4:
        ip6->protocol = IP_PROTOCOL_IP_IN_IP;
        if (t->tc_tos == 0xFF)
  	ip6_set_traffic_class_network_order (ip6,
  					     ((ip4_header_t *) (ip6 +
  								1))->tos);
        break;
  
      default:
        break;
      }
  }
  
  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_midchain_delegate_unstack (ai);
      }
    else
      {
        /* *INDENT-OFF* */
        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
        };
        /* *INDENT-ON* */
  
        adj_midchain_delegate_stack (ai, t->fib_index, &dst);
      }
  }
  
  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)
  {
    adj_midchain_fixup_t f;
    ipip_tunnel_t *t;
    adj_flags_t af;
  
    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;
    af = ADJ_FLAG_MIDCHAIN_IP_STACK;
    if (VNET_LINK_ETHERNET == adj_get_link_type (ai))
      af |= ADJ_FLAG_MIDCHAIN_NO_COUNT;
  
    adj_nbr_midchain_update_rewrite (ai, f, t, af,
  				   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;
  }
  
  static int
  ipip_tunnel_desc (u32 sw_if_index,
  		  ip46_address_t * src, ip46_address_t * dst, u8 * is_l2)
  {
    ipip_tunnel_t *t;
  
    t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
    if (!t)
      return -1;
  
    *src = t->tunnel_src;
    *dst = t->tunnel_dst;
    *is_l2 = 0;
  
    return (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,
      .ip_tun_desc = ipip_tunnel_desc,
  #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;
  }
  
  int
  ipip_add_tunnel (ipip_transport_t transport,
  		 u32 instance, ip46_address_t * src, ip46_address_t * dst,
  		 u32 fib_index, u8 tc_tos, 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);
    clib_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 */
  
    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->tc_tos = tc_tos;
  
    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);
      }
  
    /* Standard default ipip MTU. */
    vnet_sw_interface_set_mtu (vnm, sw_if_index, 9000);
  
    t->tunnel_src = *src;
    t->tunnel_dst = *dst;
  
    ipip_tunnel_db_add (t, &key);
  
    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);
    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;
  
    clib_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));
  
    return 0;
  }
  
  VLIB_INIT_FUNCTION (ipip_init);
  
  /*
   * fd.io coding-style-patch-verification: ON
   *
   * Local Variables:
   * eval: (c-set-style "gnu")
   * End:
   */
  