src/vnet/ip6-nd/ip6_nd_inline.h

   1 /*
   2  *
   3  * ip6_nd_inline.h: ip6 neighbor discovery inline
   4  *
   5  * Copyright (c) 2021 Cisco and/or its affiliates.
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at:
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  */
  18
  19 #ifndef __IP6_ND_INLINE_H__
  20 #define __IP6_ND_INLINE_H__
  21
  22 #include <vnet/ethernet/ethernet.h>
  23 #include <vnet/ip/icmp46_packet.h>
  24 #include <vnet/ip/ip6.h>
  25 #include <vnet/ip-neighbor/ip_neighbor_types.h>
  26 #include <vnet/ip6-nd/ip6_ra.h>
  27
  28 typedef enum
  29 {
  30   ICMP6_NEIGHBOR_SOLICITATION_NEXT_DROP,
  31   ICMP6_NEIGHBOR_SOLICITATION_NEXT_REPLY,
  32   ICMP6_NEIGHBOR_SOLICITATION_N_NEXT,
  33 } icmp6_neighbor_solicitation_or_advertisement_next_t;
  34
  35 static_always_inline void
  36 icmp6_send_neighbor_advertisement (
  37   vlib_main_t *vm, vlib_buffer_t *b, ip6_header_t *ip6_h,
  38   icmp6_neighbor_solicitation_or_advertisement_header_t *icmp6_nsa,
  39   icmp6_neighbor_discovery_ethernet_link_layer_address_option_t
  40     *icmp6_nd_ell_addr,
  41   u32 sw_if_index0)
  42 {
  43   vnet_main_t *vnm = vnet_get_main ();
  44   vnet_sw_interface_t *sw_if;
  45   ethernet_interface_t *eth_if;
  46   ethernet_header_t *eth;
  47   int bogus_length;
  48
  49   /* dst address is either source address or the all-nodes mcast addr */
  50   if (!ip6_address_is_unspecified (&ip6_h->src_address))
  51     ip6_h->dst_address = ip6_h->src_address;
  52   else
  53     ip6_set_reserved_multicast_address (&ip6_h->dst_address,
  54                                         IP6_MULTICAST_SCOPE_link_local,
  55                                         IP6_MULTICAST_GROUP_ID_all_hosts);
  56
  57   ip6_h->src_address = icmp6_nsa->target_address;
  58   ip6_h->hop_limit = 255;
  59   icmp6_nsa->icmp.type = ICMP6_neighbor_advertisement;
  60
  61   sw_if = vnet_get_sup_sw_interface (vnm, sw_if_index0);
  62   ASSERT (sw_if->type == VNET_SW_INTERFACE_TYPE_HARDWARE);
  63   eth_if = ethernet_get_interface (&ethernet_main, sw_if->hw_if_index);
  64   if (eth_if && icmp6_nd_ell_addr)
  65     {
  66       clib_memcpy (icmp6_nd_ell_addr->ethernet_address, &eth_if->address, 6);
  67       icmp6_nd_ell_addr->header.type =
  68         ICMP6_NEIGHBOR_DISCOVERY_OPTION_target_link_layer_address;
  69     }
  70
  71   icmp6_nsa->advertisement_flags =
  72     clib_host_to_net_u32 (ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_SOLICITED |
  73                           ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE);
  74
  75   /* if sending RAs is enabled, the "router" flag should be set,
  76    * otherwise, neighbors may believe we have changed from a router
  77    * to a host - RFC 4861 section 4.4 */
  78   if (ip6_ra_adv_enabled (sw_if_index0))
  79     icmp6_nsa->advertisement_flags |=
  80       clib_host_to_net_u32 (ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_ROUTER);
  81
  82   icmp6_nsa->icmp.checksum = 0;
  83   icmp6_nsa->icmp.checksum =
  84     ip6_tcp_udp_icmp_compute_checksum (vm, b, ip6_h, &bogus_length);
  85   ASSERT (bogus_length == 0);
  86
  87   /* Reuse current MAC header, copy SMAC to DMAC and
  88    * interface MAC to SMAC */
  89   vlib_buffer_advance (b, -ethernet_buffer_header_size (b));
  90   eth = vlib_buffer_get_current (b);
  91   clib_memcpy (eth->dst_address, eth->src_address, 6);
  92   if (eth_if)
  93     clib_memcpy (eth->src_address, &eth_if->address, 6);
  94
  95   /* Setup input and output sw_if_index for packet */
  96   ASSERT (vnet_buffer (b)->sw_if_index[VLIB_RX] == sw_if_index0);
  97   vnet_buffer (b)->sw_if_index[VLIB_TX] = sw_if_index0;
  98   vnet_buffer (b)->sw_if_index[VLIB_RX] =
  99     vnet_main.local_interface_sw_if_index;
 100
 101   vlib_increment_simple_counter (
 102     &ip_neighbor_counters[AF_IP6].ipnc[VLIB_TX][IP_NEIGHBOR_CTR_REPLY],
 103     vm->thread_index, sw_if_index0, 1);
 104 }
 105
 106 #endif /* included_ip6_nd_inline_h */
 107
 108 /*
 109  * fd.io coding-style-patch-verification: ON
 110  *
 111  * Local Variables:
 112  * eval: (c-set-style "gnu")
 113  * End:
 114  */