cnat: Destination based NAT

Type: feature

Signed-off-by: Neale Ranns <nranns@cisco.com>
Change-Id: I64a99a4fbc674212944247793fd5c1fb701408cb

1 files changed, 204 insertions, 0 deletions

diff --git a/src/plugins/cnat/cnat_translation.h b/src/plugins/cnat/cnat_translation.h
new file mode 100644
index 00000000000..748487a908a
--- /dev/null
+++ b/src/plugins/cnat/cnat_translation.h
@@ -0,0 +1,204 @@
+/*
+ * Copyright (c) 2020 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 __CNAT_TRANSLATION_H__
+#define __CNAT_TRANSLATION_H__
+
+#include <cnat/cnat_types.h>
+#include <vnet/ip/ip_types.h>
+#include <vppinfra/bihash_8_8.h>
+
+/**
+ * Counters for each translation
+ */
+extern vlib_combined_counter_main_t cnat_translation_counters;
+
+/**
+ * Data used to track an EP in the FIB
+ */
+typedef struct cnat_ep_trk_t_
+{
+  /**
+   * The EP being tracked
+   */
+  cnat_endpoint_t ct_ep[VLIB_N_DIR];
+
+  /**
+   * The FIB entry for the EP
+   */
+  fib_node_index_t ct_fei;
+
+  /**
+   * The sibling on the entry's child list
+   */
+  u32 ct_sibling;
+
+  /**
+   * The forwarding contributed by the entry
+   */
+  dpo_id_t ct_dpo;
+} cnat_ep_trk_t;
+
+typedef enum cnat_translation_flag_t_
+{
+  CNAT_TRANSLATION_FLAG_ALLOCATE_PORT = (1 << 0),
+} cnat_translation_flag_t;
+
+/**
+ * A Translation represents the translation of a VEP to one of a set
+ * of real server addresses
+ */
+typedef struct cnat_translation_t_
+{
+  /**
+   * Linkage into the FIB graph
+   */
+  fib_node_t ct_node;
+
+  /**
+   * The LB used to forward to the backends
+   */
+  dpo_id_t ct_lb;
+
+  /**
+   * The Virtual end point
+   */
+  cnat_endpoint_t ct_vip;
+
+  /**
+   * The vector of tracked back-ends
+   */
+  cnat_ep_trk_t *ct_paths;
+
+  /**
+   * The ip protocol for the translation
+   */
+  ip_protocol_t ct_proto;
+
+  /**
+   * The client object this translation belongs on
+   */
+  index_t ct_cci;
+
+  /**
+   * Own index (if copied for trace)
+   */
+  index_t index;
+
+  /**
+   * Translation flags
+   */
+  u8 flags;
+} cnat_translation_t;
+
+extern cnat_translation_t *cnat_translation_pool;
+
+extern u8 *format_cnat_translation (u8 * s, va_list * args);
+
+/**
+ * create or update a translation
+ *
+ * @param vip The Virtual Endpoint
+ * @param ip_proto The ip protocol to translate
+ * @param backends the backends to choose from
+ *
+ * @return the ID of the translation. used to delete and gather stats
+ */
+extern u32 cnat_translation_update (const cnat_endpoint_t * vip,
+				    ip_protocol_t ip_proto,
+				    const cnat_endpoint_tuple_t *
+				    backends, u8 flags);
+
+/**
+ * Add a translation to the bihash
+ *
+ * @param cci the ID of the parent client
+ * @param port the translation port
+ * @param proto the translation proto
+ * @param cti the translation index to be used as value
+ */
+extern void cnat_add_translation_to_db (index_t cci, u16 port,
+					ip_protocol_t proto, index_t cti);
+
+/**
+ * Remove a translation from the bihash
+ *
+ * @param cci the ID of the parent client
+ * @param port the translation port
+ * @param proto the translation proto
+ */
+extern void cnat_remove_translation_from_db (index_t cci, u16 port,
+					     ip_protocol_t proto);
+
+/**
+ * Delete a translation
+ *
+ * @param id the ID as returned from the create
+ */
+extern int cnat_translation_delete (u32 id);
+
+/**
+ * Callback function invoked during a walk of all translations
+ */
+typedef walk_rc_t (*cnat_translation_walk_cb_t) (index_t index, void *ctx);
+
+/**
+ * Walk/visit each of the translations
+ */
+extern void cnat_translation_walk (cnat_translation_walk_cb_t cb, void *ctx);
+
+/**
+ * Purge all the trahslations
+ */
+extern int cnat_translation_purge (void);
+
+/*
+ * Data plane functions
+ */
+extern clib_bihash_8_8_t cnat_translation_db;
+
+static_always_inline cnat_translation_t *
+cnat_translation_get (index_t cti)
+{
+  return (pool_elt_at_index (cnat_translation_pool, cti));
+}
+
+static_always_inline cnat_translation_t *
+cnat_find_translation (index_t cti, u16 port, ip_protocol_t proto)
+{
+  clib_bihash_kv_8_8_t bkey, bvalue;
+  u64 key;
+  int rv;
+
+  key = (proto << 16) | port;
+  key = key << 32 | (u32) cti;
+
+  bkey.key = key;
+  rv = clib_bihash_search_inline_2_8_8 (&cnat_translation_db, &bkey, &bvalue);
+  if (!rv)
+    return (pool_elt_at_index (cnat_translation_pool, bvalue.value));
+
+  return (NULL);
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
+
+#endif