SNAT: IP fragmentation (VPP-890)

Translation of fragmented packets.

Change-Id: I9b1f2e9433ce273638080f32c2d3bff39c49899d
Signed-off-by: Matus Fabian <matfabia@cisco.com>

1 files changed, 293 insertions, 0 deletions

diff --git a/src/plugins/nat/nat_reass.h b/src/plugins/nat/nat_reass.h
new file mode 100644
index 00000000000..ae14a9604aa
--- /dev/null
+++ b/src/plugins/nat/nat_reass.h
@@ -0,0 +1,293 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief NAT plugin virtual fragmentation reassembly
+ */
+#ifndef __included_nat_reass_h__
+#define __included_nat_reass_h__
+
+#include <vnet/vnet.h>
+#include <vnet/ip/ip.h>
+#include <vppinfra/bihash_16_8.h>
+#include <vppinfra/bihash_48_8.h>
+#include <vppinfra/dlist.h>
+
+#define NAT_REASS_TIMEOUT_DEFAULT 2
+#define NAT_MAX_REASS_DEAFULT 1024
+#define NAT_MAX_FRAG_DEFAULT 5
+#define NAT_REASS_HT_LOAD_FACTOR (0.75)
+
+typedef struct
+{
+  union
+  {
+    struct
+    {
+      ip4_address_t src;
+      ip4_address_t dst;
+      /* align by making this 4 octets even though its a 2 octets field */
+      u32 frag_id;
+      /* align by making this 4 octets even though its a 1 octet field */
+      u32 proto;
+    };
+    u64 as_u64[2];
+  };
+} nat_reass_ip4_key_t;
+
+/* *INDENT-OFF* */
+typedef CLIB_PACKED(struct
+{
+  nat_reass_ip4_key_t key;
+  u32 lru_list_index;
+  u32 sess_index;
+  f64 last_heard;
+  u32 frags_per_reass_list_head_index;
+  u8 frag_n;
+}) nat_reass_ip4_t;
+/* *INDENT-ON* */
+
+typedef struct
+{
+  union
+  {
+    struct
+    {
+      ip6_address_t src;
+      ip6_address_t dst;
+      u32 frag_id;
+      /* align by making this 4 octets even though its a 1 octet field */
+      u32 proto;
+      u64 unused;
+    };
+    u64 as_u64[6];
+  };
+} nat_reass_ip6_key_t;
+
+/* *INDENT-OFF* */
+typedef CLIB_PACKED(struct
+{
+  nat_reass_ip6_key_t key;
+  u32 lru_list_index;
+  u32 sess_index;
+  f64 last_heard;
+  u32 frags_per_reass_list_head_index;
+  u8 frag_n;
+}) nat_reass_ip6_t;
+/* *INDENT-ON* */
+
+typedef struct
+{
+  /* IPv4 config */
+  u32 ip4_timeout;
+  u16 ip4_max_reass;
+  u8 ip4_max_frag;
+  u8 ip4_drop_frag;
+
+  /* IPv6 config */
+  u32 ip6_timeout;
+  u16 ip6_max_reass;
+  u8 ip6_max_frag;
+  u8 ip6_drop_frag;
+
+  /* IPv4 runtime */
+  nat_reass_ip4_t *ip4_reass_pool;
+  clib_bihash_16_8_t ip4_reass_hash;
+  dlist_elt_t *ip4_reass_lru_list_pool;
+  dlist_elt_t *ip4_frags_list_pool;
+  u32 ip4_reass_head_index;
+  u16 ip4_reass_n;
+  clib_spinlock_t ip4_reass_lock;
+
+  /* IPv6 runtime */
+  nat_reass_ip6_t *ip6_reass_pool;
+  clib_bihash_48_8_t ip6_reass_hash;
+  dlist_elt_t *ip6_reass_lru_list_pool;
+  dlist_elt_t *ip6_frags_list_pool;
+  u32 ip6_reass_head_index;
+  u16 ip6_reass_n;
+  clib_spinlock_t ip6_reass_lock;
+
+  /* convenience */
+  vlib_main_t *vlib_main;
+  vnet_main_t *vnet_main;
+} nat_reass_main_t;
+
+/**
+ * @brief Set NAT virtual fragmentation reassembly configuration.
+ *
+ * @param timeout   Reassembly timeout.
+ * @param max_reass Maximum number of concurrent reassemblies.
+ * @param max_frag  Maximum number of fragmets per reassembly
+ * @param drop_frag If zero translate fragments, otherwise drop fragments.
+ * @param is_ip6    1 if IPv6, 0 if IPv4.
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat_reass_set (u32 timeout, u16 max_reass, u8 max_frag, u8 drop_frag,
+		   u8 is_ip6);
+
+/**
+ * @brief Get reassembly timeout.
+ *
+ * @param is_ip6 1 if IPv6, 0 if IPv4.
+ *
+ * @returns reassembly timeout.
+ */
+u32 nat_reass_get_timeout (u8 is_ip6);
+
+/**
+ * @brief Get maximum number of concurrent reassemblies.
+ *
+ * @param is_ip6 1 if IPv6, 0 if IPv4.
+ *
+ * @returns maximum number of concurrent reassemblies.
+ */
+u16 nat_reass_get_max_reass (u8 is_ip6);
+
+/**
+ * @brief Get maximum number of fragmets per reassembly.
+ *
+ * @param is_ip6 1 if IPv6, 0 if IPv4.
+ *
+ * @returns maximum number of fragmets per reassembly.
+ */
+u8 nat_reass_get_max_frag (u8 is_ip6);
+
+/**
+ * @brief Get status of virtual fragmentation reassembly.
+ *
+ * @param is_ip6 1 if IPv6, 0 if IPv4.
+ *
+ * @returns zero if translate fragments, non-zero value if drop fragments.
+ */
+u8 nat_reass_is_drop_frag (u8 is_ip6);
+
+/**
+ * @brief Initialize NAT virtual fragmentation reassembly.
+ *
+ * @param vm vlib main.
+ *
+ * @return error code.
+ */
+clib_error_t *nat_reass_init (vlib_main_t * vm);
+
+/**
+ * @brief Find or create reassembly.
+ *
+ * @param src Source IPv4 address.
+ * @param dst Destination IPv4 address.
+ * @param frag_id Fragment ID.
+ * @param proto L4 protocol.
+ * @param reset_timeout If non-zero value reset timeout.
+ * @param bi_to_drop Fragments to drop.
+ *
+ * @returns Reassembly data or 0 on failure.
+ */
+nat_reass_ip4_t *nat_ip4_reass_find_or_create (ip4_address_t src,
+					       ip4_address_t dst,
+					       u16 frag_id, u8 proto,
+					       u8 reset_timeout,
+					       u32 ** bi_to_drop);
+/**
+ * @brief Cache fragment.
+ *
+ * @param reass Reassembly data.
+ * @param bi Buffer index.
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat_ip4_reass_add_fragment (nat_reass_ip4_t * reass, u32 bi);
+
+/**
+ * @brief Get cached fragments.
+ *
+ * @param reass Reassembly data.
+ * @param bi Vector of buffer indexes.
+ */
+void nat_ip4_reass_get_frags (nat_reass_ip4_t * reass, u32 ** bi);
+
+/**
+ * @breif Call back function when walking IPv4 reassemblies, non-zero return
+ * value stop walk.
+ */
+typedef int (*nat_ip4_reass_walk_fn_t) (nat_reass_ip4_t * reass, void *ctx);
+
+/**
+ * @brief Walk IPv4 reassemblies.
+ *
+ * @param fn The function to invoke on each entry visited.
+ * @param ctx A context passed in the visit function.
+ */
+void nat_ip4_reass_walk (nat_ip4_reass_walk_fn_t fn, void *ctx);
+
+/**
+ * @brief Find or create reassembly.
+ *
+ * @param src Source IPv6 address.
+ * @param dst Destination IPv6 address.
+ * @param frag_id Fragment ID.
+ * @param proto L4 protocol.
+ * @param reset_timeout If non-zero value reset timeout.
+ * @param bi_to_drop Fragments to drop.
+ *
+ * @returns Reassembly data or 0 on failure.
+ */
+nat_reass_ip6_t *nat_ip6_reass_find_or_create (ip6_address_t src,
+					       ip6_address_t dst,
+					       u32 frag_id, u8 proto,
+					       u8 reset_timeout,
+					       u32 ** bi_to_drop);
+/**
+ * @brief Cache fragment.
+ *
+ * @param reass Reassembly data.
+ * @param bi Buffer index.
+ *
+ * @returns 0 on success, non-zero value otherwise.
+ */
+int nat_ip6_reass_add_fragment (nat_reass_ip6_t * reass, u32 bi);
+
+/**
+ * @brief Get cached fragments.
+ *
+ * @param reass Reassembly data.
+ * @param bi Vector of buffer indexes.
+ */
+void nat_ip6_reass_get_frags (nat_reass_ip6_t * reass, u32 ** bi);
+
+/**
+ * @breif Call back function when walking IPv6 reassemblies, non-zero return
+ * value stop walk.
+ */
+typedef int (*nat_ip6_reass_walk_fn_t) (nat_reass_ip6_t * reass, void *ctx);
+
+/**
+ * @brief Walk IPv6 reassemblies.
+ *
+ * @param fn The function to invoke on each entry visited.
+ * @param ctx A context passed in the visit function.
+ */
+void nat_ip6_reass_walk (nat_ip6_reass_walk_fn_t fn, void *ctx);
+
+#endif /* __included_nat_reass_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */