Simple ip4 NAT plugin

Change-Id: Iffe77bf2a05ced41474540ff54a842101aad7c41
Signed-off-by: Dave Barach <dave@barachs.net>

1 files changed, 181 insertions, 0 deletions

diff --git a/plugins/snat-plugin/snat/snat.h b/plugins/snat-plugin/snat/snat.h
new file mode 100644
index 00000000000..e3aa56276fb
--- /dev/null
+++ b/plugins/snat-plugin/snat/snat.h
@@ -0,0 +1,181 @@
+
+/*
+ * snat.h - simple nat definitions
+ *
+ * Copyright (c) 2016 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 __included_snat_h__
+#define __included_snat_h__
+
+#include <vnet/vnet.h>
+#include <vnet/ip/ip.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/ip/icmp46_packet.h>
+#include <vnet/api_errno.h>
+#include <vppinfra/bihash_8_8.h>
+#include <vppinfra/dlist.h>
+#include <vppinfra/error.h>
+#include <vlibapi/api.h>
+
+/* Key */
+typedef struct {
+  union 
+  {
+    struct 
+    {
+      ip4_address_t addr;
+      u16 port;
+      u16 protocol:3,
+        fib_index:13;
+    };
+    u64 as_u64;
+  };
+} snat_session_key_t;
+
+typedef struct {
+  union
+  {
+    struct
+    {
+      ip4_address_t addr;
+      u32 fib_index;
+    };
+    u64 as_u64;
+  };
+} snat_user_key_t;
+
+
+typedef enum {
+  SNAT_PROTOCOL_UDP = 0,
+  SNAT_PROTOCOL_TCP,
+  SNAT_PROTOCOL_ICMP,
+} snat_protocol_t;
+
+
+typedef CLIB_PACKED(struct {
+  snat_session_key_t out2in;    /* 0-15 */
+
+  snat_session_key_t in2out;    /* 16-31 */
+
+  u32 flags;                    /* 32-35 */
+
+  /* per-user translations */
+  u32 per_user_index;           /* 36-39 */
+
+  u32 per_user_list_head_index; /* 40-43 */
+
+  /* Last heard timer */
+  f64 last_heard;               /* 44-51 */
+
+  u64 total_bytes;              /* 52-59 */
+  
+  u32 total_pkts;               /* 60-63 */
+
+  /* Outside address */
+  u32 outside_address_index;    /* 64-67 */
+
+}) snat_session_t;
+
+#define SNAT_SESSION_STATIC (1<<0)
+
+typedef struct {
+  ip4_address_t addr;
+  u32 sessions_per_user_list_head_index;
+  u32 nsessions;
+} snat_user_t;
+
+typedef struct {
+  ip4_address_t addr;
+  u32 busy_ports;
+  uword * busy_port_bitmap;
+} snat_address_t;
+
+typedef struct {
+  /* Main lookup tables */
+  clib_bihash_8_8_t out2in;
+  clib_bihash_8_8_t in2out;
+
+  /* Find-a-user => src address lookup */
+  clib_bihash_8_8_t user_hash;
+
+  /* User pool */
+  snat_user_t * users;
+
+  /* Session pool */
+  snat_session_t * sessions;
+
+  /* Vector of outside addresses */
+  snat_address_t * addresses;
+
+  /* Pool of doubly-linked list elements */
+  dlist_elt_t * list_pool;
+
+  /* Randomize port allocation order */
+  u32 random_seed;
+
+  /* ip4 feature path indices */
+  u32 rx_feature_in2out;
+  u32 rx_feature_out2in;
+
+  /* Config parameters */
+  u32 translation_buckets;
+  u32 translation_memory_size;
+  u32 user_buckets;
+  u32 user_memory_size;
+  u32 max_translations_per_user;
+  u32 outside_vrf_id;
+  u32 outside_fib_index;
+
+  /* API message ID base */
+  u16 msg_id_base;
+
+  /* convenience */
+  vlib_main_t * vlib_main;
+  vnet_main_t * vnet_main;
+  ip4_main_t * ip4_main;
+  ip_lookup_main_t * ip4_lookup_main;
+  ethernet_main_t * ethernet_main;  
+  api_main_t * api_main;
+} snat_main_t;
+
+extern snat_main_t snat_main;
+extern vlib_node_registration_t snat_in2out_node;
+extern vlib_node_registration_t snat_out2in_node;
+
+void snat_free_outside_address_and_port (snat_main_t * sm, 
+                                         snat_session_key_t * k, 
+                                         u32 address_index);
+
+int snat_alloc_outside_address_and_port (snat_main_t * sm, 
+                                         snat_session_key_t * k,
+                                         u32 * address_indexp);
+format_function_t format_snat_user;
+
+typedef struct {
+  u32 cached_sw_if_index;
+  u32 cached_ip4_address;
+} snat_runtime_t;
+
+/* 
+ * Why is this here? Because we don't need to touch this layer to
+ * simply reply to an icmp. We need to change id to a unique
+ * value to NAT an echo request/reply.
+ */
+   
+typedef struct {
+  u16 identifier;
+  u16 sequence;
+} icmp_echo_header_t;
+
+#endif /* __included_snat_h__ */