ip: Protocol Independent IP Neighbors

Type: feature

 - ip-neighbour: generic neighbour handling; APIs, DBs, event handling,
aging
 - arp: ARP protocol implementation
 - ip6-nd; IPv6 neighbor discovery implementation; separate ND,
MLD, RA
 - ip6-link; manage link-local addresses
 - l2-arp-term; events separated from IP neighbours, since they are not
the same.

vnet retains just enough education to perform ND/ARP packet
construction.
arp and ip6-nd to be moved to plugins soon.

Change-Id: I88dedd0006b299344f4c7024a0aa5baa6b9a8bbe
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 112 insertions, 0 deletions

diff --git a/src/vnet/ip-neighbor/ip6_neighbor.h b/src/vnet/ip-neighbor/ip6_neighbor.h
new file mode 100644
index 00000000000..934a2885ee1
--- /dev/null
+++ b/src/vnet/ip-neighbor/ip6_neighbor.h
@@ -0,0 +1,112 @@
+/*
+ * ip/ip6_neighbor.h: IP6 NS transmit
+ *
+ * Copyright (c) 2019 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.
+ */
+
+#ifndef __IP6_NEIGHBOR_H__
+#define __IP6_NEIGHBOR_H__
+
+#include <vlib/vlib.h>
+#include <vnet/ip/format.h>
+#include <vnet/ip/ip6.h>
+#include <vnet/ip/ip6_link.h>
+#include <vnet/ip/icmp46_packet.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/adj/adj_internal.h>
+
+/* Template used to generate IP6 neighbor solicitation packets. */
+extern vlib_packet_template_t ip6_neighbor_packet_template;
+
+extern void ip6_neighbor_advertise (vlib_main_t * vm,
+				    vnet_main_t * vnm,
+				    u32 sw_if_index,
+				    const ip6_address_t * addr);
+
+extern void ip6_neighbor_probe_dst (const ip_adjacency_t * adj,
+				    const ip6_address_t * dst);
+
+always_inline vlib_buffer_t *
+ip6_neighbor_probe (vlib_main_t * vm,
+		    vnet_main_t * vnm,
+		    const ip_adjacency_t * adj,
+		    const ip6_address_t * src, const ip6_address_t * dst)
+{
+  icmp6_neighbor_solicitation_header_t *h0;
+  vnet_hw_interface_t *hw_if0;
+  vlib_buffer_t *b0;
+  int bogus_length;
+  u32 bi0 = 0;
+
+  h0 = vlib_packet_template_get_packet
+    (vm, &ip6_neighbor_packet_template, &bi0);
+  if (!h0)
+    return NULL;;
+
+  b0 = vlib_get_buffer (vm, bi0);
+
+  hw_if0 = vnet_get_sup_hw_interface (vnm, adj->rewrite_header.sw_if_index);
+
+  /*
+   * Destination address is a solicited node multicast address.
+   * We need to fill in
+   * the low 24 bits with low 24 bits of target's address.
+   */
+  h0->ip.src_address = *src;
+  h0->ip.dst_address.as_u8[13] = dst->as_u8[13];
+  h0->ip.dst_address.as_u8[14] = dst->as_u8[14];
+  h0->ip.dst_address.as_u8[15] = dst->as_u8[15];
+
+  h0->neighbor.target_address = *dst;
+
+  clib_memcpy (h0->link_layer_option.ethernet_address,
+	       hw_if0->hw_address, vec_len (hw_if0->hw_address));
+
+  /* $$$$ appears we need this; why is the checksum non-zero? */
+  h0->neighbor.icmp.checksum = 0;
+  h0->neighbor.icmp.checksum =
+    ip6_tcp_udp_icmp_compute_checksum (vm, 0, &h0->ip, &bogus_length);
+
+  ASSERT (bogus_length == 0);
+  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
+
+  vnet_buffer (b0)->sw_if_index[VLIB_TX] = adj->rewrite_header.sw_if_index;
+
+  /* Use the link's mcast adj to ship the packet */
+  vnet_buffer (b0)->ip.adj_index[VLIB_TX] =
+    ip6_link_get_mcast_adj (adj->rewrite_header.sw_if_index);
+  adj = adj_get (vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
+
+  b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
+
+  {
+    vlib_frame_t *f = vlib_get_frame_to_node (vm, adj->ia_node_index);
+    u32 *to_next = vlib_frame_vector_args (f);
+    to_next[0] = bi0;
+    f->n_vectors = 1;
+    vlib_put_frame_to_node (vm, adj->ia_node_index, f);
+  }
+
+  return b0;
+}
+
+#endif
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */