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, 91 insertions, 0 deletions

diff --git a/src/vnet/arp/arp_packet.h b/src/vnet/arp/arp_packet.h
new file mode 100644
index 00000000000..a860c258f75
--- /dev/null
+++ b/src/vnet/arp/arp_packet.h
@@ -0,0 +1,91 @@
+/*
+ * ethernet/arp.c: IP v4 ARP node
+ *
+ * Copyright (c) 2010 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 __ARP_PACKET_H__
+#define __ARP_PACKET_H__
+
+#include <vnet/arp/arp.h>
+
+/* Either we drop the packet or we send a reply to the sender. */
+typedef enum
+{
+  ARP_REPLY_NEXT_DROP,
+  ARP_REPLY_NEXT_REPLY_TX,
+  ARP_REPLY_N_NEXT,
+} arp_reply_next_t;
+
+static_always_inline u32
+arp_mk_reply (vnet_main_t * vnm,
+	      vlib_buffer_t * p0,
+	      u32 sw_if_index0,
+	      const ip4_address_t * if_addr0,
+	      ethernet_arp_header_t * arp0, ethernet_header_t * eth_rx)
+{
+  vnet_hw_interface_t *hw_if0;
+  u8 *rewrite0, rewrite0_len;
+  ethernet_header_t *eth_tx;
+  u32 next0;
+
+  /* Send a reply.
+     An adjacency to the sender is not always present,
+     so we use the interface to build us a rewrite string
+     which will contain all the necessary tags. */
+  rewrite0 = ethernet_build_rewrite (vnm, sw_if_index0,
+				     VNET_LINK_ARP, eth_rx->src_address);
+  rewrite0_len = vec_len (rewrite0);
+
+  /* Figure out how much to rewind current data from adjacency. */
+  vlib_buffer_advance (p0, -rewrite0_len);
+  eth_tx = vlib_buffer_get_current (p0);
+
+  vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
+  hw_if0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
+
+  /* Send reply back through input interface */
+  vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
+  next0 = ARP_REPLY_NEXT_REPLY_TX;
+
+  arp0->opcode = clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply);
+
+  arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
+
+  mac_address_from_bytes (&arp0->ip4_over_ethernet[0].mac,
+			  hw_if0->hw_address);
+  clib_mem_unaligned (&arp0->ip4_over_ethernet[0].ip4.data_u32, u32) =
+    if_addr0->data_u32;
+
+  /* Hardware must be ethernet-like. */
+  ASSERT (vec_len (hw_if0->hw_address) == 6);
+
+  /* the rx nd tx ethernet headers wil overlap in the case
+   * when we received a tagged VLAN=0 packet, but we are sending
+   * back untagged */
+  clib_memcpy_fast (eth_tx, rewrite0, vec_len (rewrite0));
+  vec_free (rewrite0);
+
+  return (next0);
+}
+
+#endif
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */