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/*
  Copyright (c) 2012 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.
*/

#include <vppinfra/slist.h>

/*
 * skip-list implementation
 *
 * Good news / bad news. As balanced binary tree schemes go,
 * this one seems pretty fast and is reasonably simple. There's a very
 * limited amount that can be done to mitigate sdram read latency.
 *
 * Each active clib_slist_elt_t is on from 1 to N lists. Each active element
 * is always on the "level-0" list. Since most elements are *only* on
 * level 0, we keep the level 0 (and level 1) in the element. For those
 * elements on more than two lists, we switch to a vector. Hence, the
 * "n" union in slib_slist_elt_t.
 *
 * The low-order bit of elt->n.next0[0] is 1 for inlined next indices,
 * 0 for vector indices (since the allocator always aligns to at least
 * a 4-byte boundary). We can only represent 2e9 items, but since the
 * practical performance limit is O(1e7), it doesn't matter.
 *
 * We create a "head" element which (by construction) is always
 * lexically lighter than any other element. This makes a large number
 * of irritating special cases go away.
 *
 * User code is in charge of comparing a supplied key with
 * the key component of a user pool element. The user tells this code
 * to add or delete (opaque key, 32-bit integer) pairs to the skip-list.
 *
 * The algorithm adds new elements to one or more lists.
 * For levels greater than zero, the probability of a new element landing on
 * a list is branching_factor**N. Branching_factor = 0.2 seems to work
 * OK, yielding about 50 compares per search at O(1e7) items.
 */

clib_error_t *
clib_slist_init (clib_slist_t * sp, f64 branching_factor,
		 clib_slist_key_compare_function_t compare,
		 format_function_t format_user_element)
{
  clib_slist_elt_t *head;
  clib_memset (sp, 0, sizeof (sp[0]));
  sp->branching_factor = branching_factor;
  sp->format_user_element = format_user_element;
  sp->compare = compare;
  sp->seed = 0xdeaddabe;
  pool_get (sp->elts, head);
  vec_add1 (head->n.nexts, (u32) ~ 0);
  head->user_pool_index = (u32) ~ 0;
  vec_validate (sp->path, 1);
  vec_validate (sp->occupancy, 0);

  return 0;
}

/*
 * slist_search_internal
 */
static inline clib_slist_search_result_t
slist_search_internal (clib_slist_t * sp, void *key, int need_full_path)
{
  int level, comp_result;
  clib_slist_elt_t *search_elt, *head_elt;

  sp->ncompares = 0;
  /*
   * index 0 is the magic listhead element which is
   * lexically lighter than / to the left of every element
   */
  search_elt = head_elt = pool_elt_at_index (sp->elts, 0);

  /*
   * Initial negotiating position, only the head_elt is
   * lighter than the supplied key
   */
  clib_memset (sp->path, 0, vec_len (head_elt->n.nexts) * sizeof (u32));

  /* Walk the fastest lane first */
  level = vec_len (head_elt->n.nexts) - 1;
  _vec_len (sp->path) = level + 1;

  while (1)
    {
      u32 next_index_this_level;
      clib_slist_elt_t *prefetch_elt;

      /*
       * Prefetching the next element at this level makes a measurable
       * difference, but doesn't fix the dependent read stall problem
       */
      prefetch_elt = sp->elts +
	clib_slist_get_next_at_level (search_elt, level);

      CLIB_PREFETCH (prefetch_elt, CLIB_CACHE_LINE_BYTES, READ);

      /* Compare the key with the current element */
      comp_result = (search_elt == head_elt) ? 1 :
	sp->compare (key, search_elt->user_pool_index);

      sp->ncompares++;
      /* key "lighter" than this element */
      if (comp_result < 0)
	{
	  /*
	   * Back up to previous item on this list
	   * and search the next finer-grained list
	   * starting there.
	   */
	  search_elt = pool_elt_at_index (sp->elts, sp->path[level]);
	next_list:
	  if (level > 0)
	    {
	      level--;
	      continue;
	    }
	  else
	    {
	      return CLIB_SLIST_NO_MATCH;
	    }
	}
      /* Match */
      if (comp_result == 0)
	{
	  /*
	   * If we're trying to delete an element, we need to
	   * track down all of the elements which point at it.
	   * Otherwise, don't bother with it
	   */
	  if (need_full_path && level > 0)
	    {
	      search_elt = pool_elt_at_index (sp->elts, sp->path[level]);
	      level--;
	      continue;
	    }
	  level = vec_len (head_elt->n.nexts);
	  sp->path[level] = search_elt - sp->elts;
	  _vec_len (sp->path) = level + 1;
	  return CLIB_SLIST_MATCH;
	}
      /*
       * comp_result positive, key is to the right of
       * this element
       */
      sp->path[level] = search_elt - sp->elts;

      /* Out of list at this level? */
      next_index_this_level =
	clib_slist_get_next_at_level (search_elt, level);
      if (next_index_this_level == (u32) ~ 0)
	goto next_list;

      /* No, try the next element */
      search_elt = pool_elt_at_index (sp->elts, next_index_this_level);
    }
  return 0;			/* notreached */
}

u32
clib_slist_search (clib_slist_t * sp, void *key, u32 * ncompares)
{
  clib_slist_search_result_t rv;

  rv = slist_search_internal (sp, key, 0 /* dont need full path */ );
  if (rv == CLIB_SLIST_MATCH)
    {
      clib_slist_elt_t *elt;
      elt = pool_elt_at_index (sp->elts, sp->path[vec_len (sp->path) - 1]);
      if (ncompares)
	*ncompares = sp->ncompares;
      return elt->user_pool_index;
    }
  return (u32) ~ 0;
}

void
clib_slist_add (clib_slist_t * sp, void *key, u32 user_pool_index)
{
  clib_slist_elt_t *new_elt;
  clib_slist_search_result_t search_result;
  int level;

  search_result = slist_search_internal (sp, key,
					 0 /* don't need full path */ );

  /* Special case: key exists, just replace user_pool_index */
  if (PREDICT_FALSE (search_result == CLIB_SLIST_MATCH))
    {
      clib_slist_elt_t *elt;
      elt = pool_elt_at_index (sp->elts, sp->path[0]);
      elt->user_pool_index = user_pool_index;
      return;
    }

  pool_get (sp->elts, new_elt);
  new_elt->n.nexts = 0;
  new_elt->user_pool_index = user_pool_index;

  /* sp->path lists elements to the left of key, by level */
  for (level = 0; level < vec_len (sp->path); level++)
    {
      clib_slist_elt_t *prev_elt_this_level;
      u32 prev_elt_next_index_this_level;

      /* Add to list at the current level */
      prev_elt_this_level = pool_elt_at_index (sp->elts, sp->path[level]);
      prev_elt_next_index_this_level = clib_slist_get_next_at_level
	(prev_elt_this_level, level);

      clib_slist_set_next_at_level (new_elt, prev_elt_next_index_this_level,
				    level);

      clib_slist_set_next_at_level (prev_elt_this_level, new_elt - sp->elts,
				    level);
      sp->occupancy[level]++;

      /* Randomly add to the next-higher level */
      if (random_f64 (&sp->seed) > sp->branching_factor)
	break;
    }
  {
    /* Time to add a new ply? */
    clib_slist_elt_t *head_elt = pool_elt_at_index (sp->elts, 0);
    int top_level = vec_len (head_elt->n.nexts) - 1;
    if (((f64) sp->occupancy[top_level]) * sp->branching_factor > 1.0)
      {
	vec_add1 (sp->occupancy, 0);
	vec_add1 (head_elt->n.nexts, (u32) ~ 0);
	/* full match case returns n+1 items */
	vec_validate (sp->path, vec_len (head_elt->n.nexts));
      }
  }
}

clib_slist_search_result_t
clib_slist_del (clib_slist_t * sp, void *key)
{
  clib_slist_search_result_t search_result;
  clib_slist_elt_t *del_elt;
  int level;

  search_result = slist_search_internal (sp, key, 1 /* need full path */ );

  if (PREDICT_FALSE (search_result == CLIB_SLIST_NO_MATCH))
    return search_result;

  del_elt = pool_elt_at_index (sp->elts, sp->path[vec_len (sp->path) - 1]);
  ASSERT (vec_len (sp->path) > 1);

  for (level = 0; level < vec_len (sp->path) - 1; level++)
    {
      clib_slist_elt_t *path_elt;
      u32 path_elt_next_index;

      path_elt = pool_elt_at_index (sp->elts, sp->path[level]);
      path_elt_next_index = clib_slist_get_next_at_level (path_elt, level);

      /* Splice the item out of the list if it's adjacent to the victim */
      if (path_elt_next_index == del_elt - sp->elts)
	{
	  sp->occupancy[level]--;
	  path_elt_next_index = clib_slist_get_next_at_level (del_elt, level);
	  clib_slist_set_next_at_level (path_elt, path_elt_next_index, level);
	}
    }

  /* If this element is on more than two lists it has a vector of nexts */
  if (!(del_elt->n.next0[0] & 1))
    vec_free (del_elt->n.nexts);
  pool_put (sp->elts, del_elt);
  return CLIB_SLIST_MATCH;
}

u8 *
format_slist (u8 * s, va_list * args)
{
  clib_slist_t *sl = va_arg (*args, clib_slist_t *);
  int verbose = va_arg (*args, int);
  int i;
  clib_slist_elt_t *head_elt, *elt;

  s = format (s, "slist 0x%x, %u items, branching_factor %.2f\n", sl,
	      sl->occupancy ? sl->occupancy[0] : 0, sl->branching_factor);

  if (pool_elts (sl->elts) == 0)
    return s;

  head_elt = pool_elt_at_index (sl->elts, 0);

  for (i = 0; i < vec_len (head_elt->n.nexts); i++)
    {
      s = format (s, "level %d: %d elts\n", i,
		  sl->occupancy ? sl->occupancy[i] : 0);

      if (verbose && head_elt->n.nexts[i] != (u32) ~ 0)
	{
	  elt = pool_elt_at_index (sl->elts, head_elt->n.nexts[i]);
	  while (elt)
	    {
	      u32 next_index;
	      s = format (s, "%U(%d) ", sl->format_user_element,
			  elt->user_pool_index, elt - sl->elts);
	      next_index = clib_slist_get_next_at_level (elt, i);
	      ASSERT (next_index != 0x7fffffff);
	      if (next_index == (u32) ~ 0)
		break;
	      else
		elt = pool_elt_at_index (sl->elts, next_index);
	    }
	}
      s = format (s, "\n");
    }
  return s;
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */
6' href='#n1776'>1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199
/*
 * 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.
 */
/**
 * @file
 * @brief NAT44 inside to outside network translation
 */

#include <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vnet/pg/pg.h>

#include <vnet/ip/ip.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/fib/ip4_fib.h>
#include <nat/nat.h>
#include <nat/nat_ipfix_logging.h>
#include <nat/nat_reass.h>
#include <nat/nat_inlines.h>
#include <nat/nat_syslog.h>
#include <nat/nat_ha.h>

#include <vppinfra/hash.h>
#include <vppinfra/error.h>
#include <vppinfra/elog.h>

typedef struct
{
  u32 sw_if_index;
  u32 next_index;
  u32 session_index;
  u32 is_slow_path;
} snat_in2out_trace_t;

/* packet trace format function */
static u8 *
format_snat_in2out_trace (u8 * s, va_list * args)
{
  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  snat_in2out_trace_t *t = va_arg (*args, snat_in2out_trace_t *);
  char *tag;

  tag = t->is_slow_path ? "NAT44_IN2OUT_SLOW_PATH" : "NAT44_IN2OUT_FAST_PATH";

  s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
	      t->sw_if_index, t->next_index, t->session_index);

  return s;
}

static u8 *
format_snat_in2out_fast_trace (u8 * s, va_list * args)
{
  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  snat_in2out_trace_t *t = va_arg (*args, snat_in2out_trace_t *);

  s = format (s, "NAT44_IN2OUT_FAST: sw_if_index %d, next index %d",
	      t->sw_if_index, t->next_index);

  return s;
}

#define foreach_snat_in2out_error                       \
_(UNSUPPORTED_PROTOCOL, "unsupported protocol")         \
_(IN2OUT_PACKETS, "good in2out packets processed")      \
_(OUT_OF_PORTS, "out of ports")                         \
_(BAD_OUTSIDE_FIB, "outside VRF ID not found")          \
_(BAD_ICMP_TYPE, "unsupported ICMP type")               \
_(NO_TRANSLATION, "no translation")                     \
_(MAX_SESSIONS_EXCEEDED, "maximum sessions exceeded")   \
_(DROP_FRAGMENT, "drop fragment")                       \
_(MAX_REASS, "maximum reassemblies exceeded")           \
_(MAX_FRAG, "maximum fragments per reassembly exceeded")\
_(TCP_PACKETS, "TCP packets")                           \
_(UDP_PACKETS, "UDP packets")                           \
_(ICMP_PACKETS, "ICMP packets")                         \
_(OTHER_PACKETS, "other protocol packets")              \
_(FRAGMENTS, "fragments")                               \
_(CACHED_FRAGMENTS, "cached fragments")                 \
_(PROCESSED_FRAGMENTS, "processed fragments")

typedef enum
{
#define _(sym,str) SNAT_IN2OUT_ERROR_##sym,
  foreach_snat_in2out_error
#undef _
    SNAT_IN2OUT_N_ERROR,
} snat_in2out_error_t;

static char *snat_in2out_error_strings[] = {
#define _(sym,string) string,
  foreach_snat_in2out_error
#undef _
};

typedef enum
{
  SNAT_IN2OUT_NEXT_LOOKUP,
  SNAT_IN2OUT_NEXT_DROP,
  SNAT_IN2OUT_NEXT_ICMP_ERROR,
  SNAT_IN2OUT_NEXT_SLOW_PATH,
  SNAT_IN2OUT_NEXT_REASS,
  SNAT_IN2OUT_N_NEXT,
} snat_in2out_next_t;

static inline int
snat_not_translate (snat_main_t * sm, vlib_node_runtime_t * node,
		    u32 sw_if_index0, ip4_header_t * ip0, u32 proto0,
		    u32 rx_fib_index0, u32 thread_index)
{
  udp_header_t *udp0 = ip4_next_header (ip0);
  snat_session_key_t key0, sm0;
  clib_bihash_kv_8_8_t kv0, value0;

  key0.addr = ip0->dst_address;
  key0.port = udp0->dst_port;
  key0.protocol = proto0;
  key0.fib_index = sm->outside_fib_index;
  kv0.key = key0.as_u64;

  /* NAT packet aimed at external address if */
  /* has active sessions */
  if (clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].out2in, &kv0,
			      &value0))
    {
      /* or is static mappings */
      if (!snat_static_mapping_match (sm, key0, &sm0, 1, 0, 0, 0, 0, 0))
	return 0;
    }
  else
    return 0;

  if (sm->forwarding_enabled)
    return 1;

  return snat_not_translate_fast (sm, node, sw_if_index0, ip0, proto0,
				  rx_fib_index0);
}

static inline int
nat_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip0,
				  u32 proto0, u16 src_port, u16 dst_port,
				  u32 thread_index, u32 sw_if_index)
{
  snat_session_key_t key0;
  clib_bihash_kv_8_8_t kv0, value0;
  snat_interface_t *i;

  /* src NAT check */
  key0.addr = ip0->src_address;
  key0.port = src_port;
  key0.protocol = proto0;
  key0.fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
  kv0.key = key0.as_u64;

  if (!clib_bihash_search_8_8
      (&sm->per_thread_data[thread_index].out2in, &kv0, &value0))
    return 1;

  /* dst NAT check */
  key0.addr = ip0->dst_address;
  key0.port = dst_port;
  key0.protocol = proto0;
  kv0.key = key0.as_u64;
  if (!clib_bihash_search_8_8
      (&sm->per_thread_data[thread_index].in2out, &kv0, &value0))
    {
      /* hairpinning */
    /* *INDENT-OFF* */
    pool_foreach (i, sm->output_feature_interfaces,
    ({
      if ((nat_interface_is_inside(i)) && (sw_if_index == i->sw_if_index))
        return 0;
    }));
    /* *INDENT-ON* */
      return 1;
    }

  return 0;
}

#ifndef CLIB_MARCH_VARIANT
int
nat44_i2o_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg)
{
  snat_main_t *sm = &snat_main;
  nat44_is_idle_session_ctx_t *ctx = arg;
  snat_session_t *s;
  u64 sess_timeout_time;
  snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
						       ctx->thread_index);
  clib_bihash_kv_8_8_t s_kv;

  s = pool_elt_at_index (tsm->sessions, kv->value);
  sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
  if (ctx->now >= sess_timeout_time)
    {
      s_kv.key = s->out2in.as_u64;
      if (clib_bihash_add_del_8_8 (&tsm->out2in, &s_kv, 0))
	nat_log_warn ("out2in key del failed");

      snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
					   s->in2out.addr.as_u32,
					   s->out2in.addr.as_u32,
					   s->in2out.protocol,
					   s->in2out.port,
					   s->out2in.port,
					   s->in2out.fib_index);

      nat_syslog_nat44_apmdel (s->user_index, s->in2out.fib_index,
			       &s->in2out.addr, s->in2out.port,
			       &s->out2in.addr, s->out2in.port,
			       s->in2out.protocol);

      nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
		   s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
		   ctx->thread_index);

      if (!snat_is_session_static (s))
	snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
					    &s->out2in);

      nat44_delete_session (sm, s, ctx->thread_index);
      return 1;
    }

  return 0;
}
#endif

static u32
slow_path (snat_main_t * sm, vlib_buffer_t * b0,
	   ip4_header_t * ip0,
	   u32 rx_fib_index0,
	   snat_session_key_t * key0,
	   snat_session_t ** sessionp,
	   vlib_node_runtime_t * node, u32 next0, u32 thread_index, f64 now)
{
  snat_user_t *u;
  snat_session_t *s = 0;
  clib_bihash_kv_8_8_t kv0;
  snat_session_key_t key1;
  udp_header_t *udp0 = ip4_next_header (ip0);
  u8 is_sm = 0;
  nat_outside_fib_t *outside_fib;
  fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
  u8 identity_nat;
  fib_prefix_t pfx = {
    .fp_proto = FIB_PROTOCOL_IP4,
    .fp_len = 32,
    .fp_addr = {
		.ip4.as_u32 = ip0->dst_address.as_u32,
		},
  };
  nat44_is_idle_session_ctx_t ctx0;

  if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
    {
      b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
      nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
      nat_log_notice ("maximum sessions exceeded");
      return SNAT_IN2OUT_NEXT_DROP;
    }

  key1.protocol = key0->protocol;

  /* First try to match static mapping by local address and port */
  if (snat_static_mapping_match
      (sm, *key0, &key1, 0, 0, 0, 0, 0, &identity_nat))
    {
      /* Try to create dynamic translation */
      if (snat_alloc_outside_address_and_port (sm->addresses, rx_fib_index0,
					       thread_index, &key1,
					       sm->port_per_thread,
					       sm->per_thread_data
					       [thread_index].snat_thread_index))
	{
	  b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
	  return SNAT_IN2OUT_NEXT_DROP;
	}
    }
  else
    {
      if (PREDICT_FALSE (identity_nat))
	{
	  *sessionp = s;
	  return next0;
	}

      is_sm = 1;
    }

  u = nat_user_get_or_create (sm, &ip0->src_address, rx_fib_index0,
			      thread_index);
  if (!u)
    {
      nat_log_warn ("create NAT user failed");
      return SNAT_IN2OUT_NEXT_DROP;
    }

  s = nat_session_alloc_or_recycle (sm, u, thread_index, now);
  if (!s)
    {
      nat44_delete_user_with_no_session (sm, u, thread_index);
      nat_log_warn ("create NAT session failed");
      return SNAT_IN2OUT_NEXT_DROP;
    }

  if (is_sm)
    s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
  user_session_increment (sm, u, is_sm);
  s->in2out = *key0;
  s->out2in = key1;
  s->out2in.protocol = key0->protocol;
  s->out2in.fib_index = sm->outside_fib_index;
  switch (vec_len (sm->outside_fibs))
    {
    case 0:
      s->out2in.fib_index = sm->outside_fib_index;
      break;
    case 1:
      s->out2in.fib_index = sm->outside_fibs[0].fib_index;
      break;
    default:
      /* *INDENT-OFF* */
      vec_foreach (outside_fib, sm->outside_fibs)
        {
          fei = fib_table_lookup (outside_fib->fib_index, &pfx);
          if (FIB_NODE_INDEX_INVALID != fei)
            {
              if (fib_entry_get_resolving_interface (fei) != ~0)
                {
                  s->out2in.fib_index = outside_fib->fib_index;
                  break;
                }
            }
        }
      /* *INDENT-ON* */
      break;
    }
  s->ext_host_addr.as_u32 = ip0->dst_address.as_u32;
  s->ext_host_port = udp0->dst_port;
  *sessionp = s;

  /* Add to translation hashes */
  ctx0.now = now;
  ctx0.thread_index = thread_index;
  kv0.key = s->in2out.as_u64;
  kv0.value = s - sm->per_thread_data[thread_index].sessions;
  if (clib_bihash_add_or_overwrite_stale_8_8
      (&sm->per_thread_data[thread_index].in2out, &kv0,
       nat44_i2o_is_idle_session_cb, &ctx0))
    nat_log_notice ("in2out key add failed");

  kv0.key = s->out2in.as_u64;
  kv0.value = s - sm->per_thread_data[thread_index].sessions;

  if (clib_bihash_add_or_overwrite_stale_8_8
      (&sm->per_thread_data[thread_index].out2in, &kv0,
       nat44_o2i_is_idle_session_cb, &ctx0))
    nat_log_notice ("out2in key add failed");

  /* log NAT event */
  snat_ipfix_logging_nat44_ses_create (thread_index,
				       s->in2out.addr.as_u32,
				       s->out2in.addr.as_u32,
				       s->in2out.protocol,
				       s->in2out.port,
				       s->out2in.port, s->in2out.fib_index);

  nat_syslog_nat44_apmadd (s->user_index, s->in2out.fib_index,
			   &s->in2out.addr, s->in2out.port, &s->out2in.addr,
			   s->out2in.port, s->in2out.protocol);

  nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
	       s->out2in.port, &s->ext_host_addr, s->ext_host_port,
	       &s->ext_host_nat_addr, s->ext_host_nat_port,
	       s->in2out.protocol, s->in2out.fib_index, s->flags,
	       thread_index, 0);

  return next0;
}

#ifndef CLIB_MARCH_VARIANT
static_always_inline
  snat_in2out_error_t icmp_get_key (ip4_header_t * ip0,
				    snat_session_key_t * p_key0)
{
  icmp46_header_t *icmp0;
  snat_session_key_t key0;
  icmp_echo_header_t *echo0, *inner_echo0 = 0;
  ip4_header_t *inner_ip0 = 0;
  void *l4_header = 0;
  icmp46_header_t *inner_icmp0;

  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
  echo0 = (icmp_echo_header_t *) (icmp0 + 1);

  if (!icmp_is_error_message (icmp0))
    {
      key0.protocol = SNAT_PROTOCOL_ICMP;
      key0.addr = ip0->src_address;
      key0.port = echo0->identifier;
    }
  else
    {
      inner_ip0 = (ip4_header_t *) (echo0 + 1);
      l4_header = ip4_next_header (inner_ip0);
      key0.protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
      key0.addr = inner_ip0->dst_address;
      switch (key0.protocol)
	{
	case SNAT_PROTOCOL_ICMP:
	  inner_icmp0 = (icmp46_header_t *) l4_header;
	  inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
	  key0.port = inner_echo0->identifier;
	  break;
	case SNAT_PROTOCOL_UDP:
	case SNAT_PROTOCOL_TCP:
	  key0.port = ((tcp_udp_header_t *) l4_header)->dst_port;
	  break;
	default:
	  return SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL;
	}
    }
  *p_key0 = key0;
  return -1;			/* success */
}

/**
 * Get address and port values to be used for ICMP packet translation
 * and create session if needed
 *
 * @param[in,out] sm             NAT main
 * @param[in,out] node           NAT node runtime
 * @param[in] thread_index       thread index
 * @param[in,out] b0             buffer containing packet to be translated
 * @param[out] p_proto           protocol used for matching
 * @param[out] p_value           address and port after NAT translation
 * @param[out] p_dont_translate  if packet should not be translated
 * @param d                      optional parameter
 * @param e                      optional parameter
 */
u32
icmp_match_in2out_slow (snat_main_t * sm, vlib_node_runtime_t * node,
			u32 thread_index, vlib_buffer_t * b0,
			ip4_header_t * ip0, u8 * p_proto,
			snat_session_key_t * p_value,
			u8 * p_dont_translate, void *d, void *e)
{
  icmp46_header_t *icmp0;
  u32 sw_if_index0;
  u32 rx_fib_index0;
  snat_session_key_t key0;
  snat_session_t *s0 = 0;
  u8 dont_translate = 0;
  clib_bihash_kv_8_8_t kv0, value0;
  u32 next0 = ~0;
  int err;

  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);

  err = icmp_get_key (ip0, &key0);
  if (err != -1)
    {
      b0->error = node->errors[err];
      next0 = SNAT_IN2OUT_NEXT_DROP;
      goto out;
    }
  key0.fib_index = rx_fib_index0;

  kv0.key = key0.as_u64;

  if (clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].in2out, &kv0,
			      &value0))
    {
      if (vnet_buffer (b0)->sw_if_index[VLIB_TX] != ~0)
	{
	  if (PREDICT_FALSE (nat_not_translate_output_feature (sm, ip0,
							       key0.protocol,
							       key0.port,
							       key0.port,
							       thread_index,
							       sw_if_index0)))
	    {
	      dont_translate = 1;
	      goto out;
	    }
	}
      else
	{
	  if (PREDICT_FALSE (snat_not_translate (sm, node, sw_if_index0,
						 ip0, SNAT_PROTOCOL_ICMP,
						 rx_fib_index0,
						 thread_index)))
	    {
	      dont_translate = 1;
	      goto out;
	    }
	}

      if (PREDICT_FALSE (icmp_is_error_message (icmp0)))
	{
	  b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
	  next0 = SNAT_IN2OUT_NEXT_DROP;
	  goto out;
	}

      next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0, &s0, node, next0,
			 thread_index, vlib_time_now (sm->vlib_main));

      if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
	goto out;

      if (!s0)
	{
	  dont_translate = 1;
	  goto out;
	}
    }
  else
    {
      if (PREDICT_FALSE (icmp0->type != ICMP4_echo_request &&
			 icmp0->type != ICMP4_echo_reply &&
			 !icmp_is_error_message (icmp0)))
	{
	  b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
	  next0 = SNAT_IN2OUT_NEXT_DROP;
	  goto out;
	}

      s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
			      value0.value);
    }

out:
  *p_proto = key0.protocol;
  if (s0)
    *p_value = s0->out2in;
  *p_dont_translate = dont_translate;
  if (d)
    *(snat_session_t **) d = s0;
  return next0;
}
#endif

#ifndef CLIB_MARCH_VARIANT
/**
 * Get address and port values to be used for ICMP packet translation
 *
 * @param[in] sm                 NAT main
 * @param[in,out] node           NAT node runtime
 * @param[in] thread_index       thread index
 * @param[in,out] b0             buffer containing packet to be translated
 * @param[out] p_proto           protocol used for matching
 * @param[out] p_value           address and port after NAT translation
 * @param[out] p_dont_translate  if packet should not be translated
 * @param d                      optional parameter
 * @param e                      optional parameter
 */
u32
icmp_match_in2out_fast (snat_main_t * sm, vlib_node_runtime_t * node,
			u32 thread_index, vlib_buffer_t * b0,
			ip4_header_t * ip0, u8 * p_proto,
			snat_session_key_t * p_value,
			u8 * p_dont_translate, void *d, void *e)
{
  icmp46_header_t *icmp0;
  u32 sw_if_index0;
  u32 rx_fib_index0;
  snat_session_key_t key0;
  snat_session_key_t sm0;
  u8 dont_translate = 0;
  u8 is_addr_only;
  u32 next0 = ~0;
  int err;

  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);

  err = icmp_get_key (ip0, &key0);
  if (err != -1)
    {
      b0->error = node->errors[err];
      next0 = SNAT_IN2OUT_NEXT_DROP;
      goto out2;
    }
  key0.fib_index = rx_fib_index0;

  if (snat_static_mapping_match
      (sm, key0, &sm0, 0, &is_addr_only, 0, 0, 0, 0))
    {
      if (PREDICT_FALSE (snat_not_translate_fast (sm, node, sw_if_index0, ip0,
						  IP_PROTOCOL_ICMP,
						  rx_fib_index0)))
	{
	  dont_translate = 1;
	  goto out;
	}

      if (icmp_is_error_message (icmp0))
	{
	  next0 = SNAT_IN2OUT_NEXT_DROP;
	  goto out;
	}

      b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
      next0 = SNAT_IN2OUT_NEXT_DROP;
      goto out;
    }

  if (PREDICT_FALSE (icmp0->type != ICMP4_echo_request &&
		     (icmp0->type != ICMP4_echo_reply || !is_addr_only) &&
		     !icmp_is_error_message (icmp0)))
    {
      b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
      next0 = SNAT_IN2OUT_NEXT_DROP;
      goto out;
    }

out:
  *p_value = sm0;
out2:
  *p_proto = key0.protocol;
  *p_dont_translate = dont_translate;
  return next0;
}
#endif

#ifndef CLIB_MARCH_VARIANT
u32
icmp_in2out (snat_main_t * sm,
	     vlib_buffer_t * b0,
	     ip4_header_t * ip0,
	     icmp46_header_t * icmp0,
	     u32 sw_if_index0,
	     u32 rx_fib_index0,
	     vlib_node_runtime_t * node,
	     u32 next0, u32 thread_index, void *d, void *e)
{
  snat_session_key_t sm0;
  u8 protocol;
  icmp_echo_header_t *echo0, *inner_echo0 = 0;
  ip4_header_t *inner_ip0;
  void *l4_header = 0;
  icmp46_header_t *inner_icmp0;
  u8 dont_translate;
  u32 new_addr0, old_addr0;
  u16 old_id0, new_id0;
  u16 old_checksum0, new_checksum0;
  ip_csum_t sum0;
  u16 checksum0;
  u32 next0_tmp;

  echo0 = (icmp_echo_header_t *) (icmp0 + 1);

  next0_tmp = sm->icmp_match_in2out_cb (sm, node, thread_index, b0, ip0,
					&protocol, &sm0, &dont_translate, d,
					e);
  if (next0_tmp != ~0)
    next0 = next0_tmp;
  if (next0 == SNAT_IN2OUT_NEXT_DROP || dont_translate)
    goto out;

  if (PREDICT_TRUE (!ip4_is_fragment (ip0)))
    {
      sum0 = ip_incremental_checksum_buffer (sm->vlib_main, b0, (u8 *) icmp0 -
					     (u8 *)
					     vlib_buffer_get_current (b0),
					     ntohs (ip0->length) -
					     ip4_header_bytes (ip0), 0);
      checksum0 = ~ip_csum_fold (sum0);
      if (PREDICT_FALSE (checksum0 != 0 && checksum0 != 0xffff))
	{
	  next0 = SNAT_IN2OUT_NEXT_DROP;
	  goto out;
	}
    }

  old_addr0 = ip0->src_address.as_u32;
  new_addr0 = ip0->src_address.as_u32 = sm0.addr.as_u32;

  sum0 = ip0->checksum;
  sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
			 src_address /* changed member */ );
  ip0->checksum = ip_csum_fold (sum0);

  if (icmp0->checksum == 0)
    icmp0->checksum = 0xffff;

  if (!icmp_is_error_message (icmp0))
    {
      new_id0 = sm0.port;
      if (PREDICT_FALSE (new_id0 != echo0->identifier))
	{
	  old_id0 = echo0->identifier;
	  new_id0 = sm0.port;
	  echo0->identifier = new_id0;

	  sum0 = icmp0->checksum;
	  sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
				 identifier);
	  icmp0->checksum = ip_csum_fold (sum0);
	}
    }
  else
    {
      inner_ip0 = (ip4_header_t *) (echo0 + 1);
      l4_header = ip4_next_header (inner_ip0);

      if (!ip4_header_checksum_is_valid (inner_ip0))
	{
	  next0 = SNAT_IN2OUT_NEXT_DROP;
	  goto out;
	}

      /* update inner destination IP address */
      old_addr0 = inner_ip0->dst_address.as_u32;
      inner_ip0->dst_address = sm0.addr;
      new_addr0 = inner_ip0->dst_address.as_u32;
      sum0 = icmp0->checksum;
      sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
			     dst_address /* changed member */ );
      icmp0->checksum = ip_csum_fold (sum0);

      /* update inner IP header checksum */
      old_checksum0 = inner_ip0->checksum;
      sum0 = inner_ip0->checksum;
      sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
			     dst_address /* changed member */ );
      inner_ip0->checksum = ip_csum_fold (sum0);
      new_checksum0 = inner_ip0->checksum;
      sum0 = icmp0->checksum;
      sum0 = ip_csum_update (sum0, old_checksum0, new_checksum0, ip4_header_t,
			     checksum);
      icmp0->checksum = ip_csum_fold (sum0);

      switch (protocol)
	{
	case SNAT_PROTOCOL_ICMP:
	  inner_icmp0 = (icmp46_header_t *) l4_header;
	  inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);

	  old_id0 = inner_echo0->identifier;
	  new_id0 = sm0.port;
	  inner_echo0->identifier = new_id0;

	  sum0 = icmp0->checksum;
	  sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
				 identifier);
	  icmp0->checksum = ip_csum_fold (sum0);
	  break;
	case SNAT_PROTOCOL_UDP:
	case SNAT_PROTOCOL_TCP:
	  old_id0 = ((tcp_udp_header_t *) l4_header)->dst_port;
	  new_id0 = sm0.port;
	  ((tcp_udp_header_t *) l4_header)->dst_port = new_id0;

	  sum0 = icmp0->checksum;
	  sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
				 dst_port);
	  icmp0->checksum = ip_csum_fold (sum0);
	  break;
	default:
	  ASSERT (0);
	}
    }

  if (vnet_buffer (b0)->sw_if_index[VLIB_TX] == ~0)
    {
      if (sm->deterministic ||
	  0 != snat_icmp_hairpinning (sm, b0, ip0, icmp0,
				      sm->endpoint_dependent))
	vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
    }

out:
  return next0;
}
#endif

static inline u32
icmp_in2out_slow_path (snat_main_t * sm,
		       vlib_buffer_t * b0,
		       ip4_header_t * ip0,
		       icmp46_header_t * icmp0,
		       u32 sw_if_index0,
		       u32 rx_fib_index0,
		       vlib_node_runtime_t * node,
		       u32 next0,
		       f64 now, u32 thread_index, snat_session_t ** p_s0)
{
  next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
		       next0, thread_index, p_s0, 0);
  snat_session_t *s0 = *p_s0;
  if (PREDICT_TRUE (next0 != SNAT_IN2OUT_NEXT_DROP && s0))
    {
      /* Accounting */
      nat44_session_update_counters (s0, now,
				     vlib_buffer_length_in_chain
				     (sm->vlib_main, b0), thread_index);
      /* Per-user LRU list maintenance */
      nat44_session_update_lru (sm, s0, thread_index);
    }
  return next0;
}

static int
nat_in2out_sm_unknown_proto (snat_main_t * sm,
			     vlib_buffer_t * b,
			     ip4_header_t * ip, u32 rx_fib_index)
{
  clib_bihash_kv_8_8_t kv, value;
  snat_static_mapping_t *m;
  snat_session_key_t m_key;
  u32 old_addr, new_addr;
  ip_csum_t sum;

  m_key.addr = ip->src_address;
  m_key.port = 0;
  m_key.protocol = 0;
  m_key.fib_index = rx_fib_index;
  kv.key = m_key.as_u64;
  if (clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
    return 1;

  m = pool_elt_at_index (sm->static_mappings, value.value);

  old_addr = ip->src_address.as_u32;
  new_addr = ip->src_address.as_u32 = m->external_addr.as_u32;
  sum = ip->checksum;
  sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, src_address);
  ip->checksum = ip_csum_fold (sum);


  /* Hairpinning */
  if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
    {
      vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
      nat_hairpinning_sm_unknown_proto (sm, b, ip);
    }

  return 0;
}

static inline uword
snat_in2out_node_fn_inline (vlib_main_t * vm,
			    vlib_node_runtime_t * node,
			    vlib_frame_t * frame, int is_slow_path,
			    int is_output_feature)
{
  u32 n_left_from, *from, *to_next;
  snat_in2out_next_t next_index;
  u32 pkts_processed = 0;
  snat_main_t *sm = &snat_main;
  f64 now = vlib_time_now (vm);
  u32 stats_node_index;
  u32 thread_index = vm->thread_index;
  u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
    0, fragments = 0;

  stats_node_index = is_slow_path ? sm->in2out_slowpath_node_index :
    sm->in2out_node_index;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from >= 4 && n_left_to_next >= 2)
	{
	  u32 bi0, bi1;
	  vlib_buffer_t *b0, *b1;
	  u32 next0, next1;
	  u32 sw_if_index0, sw_if_index1;
	  ip4_header_t *ip0, *ip1;
	  ip_csum_t sum0, sum1;
	  u32 new_addr0, old_addr0, new_addr1, old_addr1;
	  u16 old_port0, new_port0, old_port1, new_port1;
	  udp_header_t *udp0, *udp1;
	  tcp_header_t *tcp0, *tcp1;
	  icmp46_header_t *icmp0, *icmp1;
	  snat_session_key_t key0, key1;
	  u32 rx_fib_index0, rx_fib_index1;
	  u32 proto0, proto1;
	  snat_session_t *s0 = 0, *s1 = 0;
	  clib_bihash_kv_8_8_t kv0, value0, kv1, value1;
	  u32 iph_offset0 = 0, iph_offset1 = 0;

	  /* Prefetch next iteration. */
	  {
	    vlib_buffer_t *p2, *p3;

	    p2 = vlib_get_buffer (vm, from[2]);
	    p3 = vlib_get_buffer (vm, from[3]);

	    vlib_prefetch_buffer_header (p2, LOAD);
	    vlib_prefetch_buffer_header (p3, LOAD);

	    CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
	    CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
	  }

	  /* speculatively enqueue b0 and b1 to the current next frame */
	  to_next[0] = bi0 = from[0];
	  to_next[1] = bi1 = from[1];
	  from += 2;
	  to_next += 2;
	  n_left_from -= 2;
	  n_left_to_next -= 2;

	  b0 = vlib_get_buffer (vm, bi0);
	  b1 = vlib_get_buffer (vm, bi1);

	  if (is_output_feature)
	    iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;

	  ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
				  iph_offset0);

	  udp0 = ip4_next_header (ip0);
	  tcp0 = (tcp_header_t *) udp0;
	  icmp0 = (icmp46_header_t *) udp0;

	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
	  rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
				   sw_if_index0);

	  next0 = next1 = SNAT_IN2OUT_NEXT_LOOKUP;

	  if (PREDICT_FALSE (ip0->ttl == 1))
	    {
	      vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
	      icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
					   ICMP4_time_exceeded_ttl_exceeded_in_transit,
					   0);
	      next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
	      goto trace00;
	    }

	  proto0 = ip_proto_to_snat_proto (ip0->protocol);

	  /* Next configured feature, probably ip4-lookup */
	  if (is_slow_path)
	    {
	      if (PREDICT_FALSE (proto0 == ~0))
		{
		  if (nat_in2out_sm_unknown_proto
		      (sm, b0, ip0, rx_fib_index0))
		    {
		      next0 = SNAT_IN2OUT_NEXT_DROP;
		      b0->error =
			node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
		    }
		  other_packets++;
		  goto trace00;
		}

	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
		{
		  next0 = icmp_in2out_slow_path
		    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
		     node, next0, now, thread_index, &s0);
		  icmp_packets++;
		  goto trace00;
		}
	    }
	  else
	    {
	      if (PREDICT_FALSE (proto0 == ~0))
		{
		  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
		  goto trace00;
		}

	      if (ip4_is_fragment (ip0))
		{
		  next0 = SNAT_IN2OUT_NEXT_REASS;
		  fragments++;
		  goto trace00;
		}

	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
		{
		  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
		  goto trace00;
		}
	    }

	  key0.addr = ip0->src_address;
	  key0.port = udp0->src_port;
	  key0.protocol = proto0;
	  key0.fib_index = rx_fib_index0;

	  kv0.key = key0.as_u64;

	  if (PREDICT_FALSE
	      (clib_bihash_search_8_8
	       (&sm->per_thread_data[thread_index].in2out, &kv0,
		&value0) != 0))
	    {
	      if (is_slow_path)
		{
		  if (is_output_feature)
		    {
		      if (PREDICT_FALSE (nat_not_translate_output_feature (sm,
									   ip0,
									   proto0,
									   udp0->src_port,
									   udp0->dst_port,
									   thread_index,
									   sw_if_index0)))
			goto trace00;
		    }
		  else
		    {
		      if (PREDICT_FALSE
			  (snat_not_translate
			   (sm, node, sw_if_index0, ip0, proto0,
			    rx_fib_index0, thread_index)))
			goto trace00;
		    }

		  next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
				     &s0, node, next0, thread_index, now);
		  if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
		    goto trace00;

		  if (PREDICT_FALSE (!s0))
		    goto trace00;
		}
	      else
		{
		  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
		  goto trace00;
		}
	    }
	  else
	    s0 =
	      pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
				 value0.value);

	  b0->flags |= VNET_BUFFER_F_IS_NATED;

	  old_addr0 = ip0->src_address.as_u32;
	  ip0->src_address = s0->out2in.addr;
	  new_addr0 = ip0->src_address.as_u32;
	  if (!is_output_feature)
	    vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;

	  sum0 = ip0->checksum;
	  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
				 ip4_header_t,
				 src_address /* changed member */ );
	  ip0->checksum = ip_csum_fold (sum0);

	  if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
	    {
	      old_port0 = tcp0->src_port;
	      tcp0->src_port = s0->out2in.port;
	      new_port0 = tcp0->src_port;

	      sum0 = tcp0->checksum;
	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
				     ip4_header_t,
				     dst_address /* changed member */ );
	      sum0 = ip_csum_update (sum0, old_port0, new_port0,
				     ip4_header_t /* cheat */ ,
				     length /* changed member */ );
	      mss_clamping (sm, tcp0, &sum0);
	      tcp0->checksum = ip_csum_fold (sum0);
	      tcp_packets++;
	    }
	  else
	    {
	      old_port0 = udp0->src_port;
	      udp0->src_port = s0->out2in.port;
	      udp0->checksum = 0;
	      udp_packets++;
	    }

	  /* Accounting */
	  nat44_session_update_counters (s0, now,
					 vlib_buffer_length_in_chain (vm, b0),
					 thread_index);
	  /* Per-user LRU list maintenance */
	  nat44_session_update_lru (sm, s0, thread_index);
	trace00:

	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
	    {
	      snat_in2out_trace_t *t =
		vlib_add_trace (vm, node, b0, sizeof (*t));
	      t->is_slow_path = is_slow_path;
	      t->sw_if_index = sw_if_index0;
	      t->next_index = next0;
	      t->session_index = ~0;
	      if (s0)
		t->session_index =
		  s0 - sm->per_thread_data[thread_index].sessions;
	    }

	  pkts_processed += next0 == SNAT_IN2OUT_NEXT_LOOKUP;

	  if (is_output_feature)
	    iph_offset1 = vnet_buffer (b1)->ip.save_rewrite_length;

	  ip1 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b1) +
				  iph_offset1);

	  udp1 = ip4_next_header (ip1);
	  tcp1 = (tcp_header_t *) udp1;
	  icmp1 = (icmp46_header_t *) udp1;

	  sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
	  rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
				   sw_if_index1);

	  if (PREDICT_FALSE (ip1->ttl == 1))
	    {
	      vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
	      icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
					   ICMP4_time_exceeded_ttl_exceeded_in_transit,
					   0);
	      next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
	      goto trace01;
	    }

	  proto1 = ip_proto_to_snat_proto (ip1->protocol);

	  /* Next configured feature, probably ip4-lookup */
	  if (is_slow_path)
	    {
	      if (PREDICT_FALSE (proto1 == ~0))
		{
		  if (nat_in2out_sm_unknown_proto
		      (sm, b1, ip1, rx_fib_index1))
		    {
		      next1 = SNAT_IN2OUT_NEXT_DROP;
		      b1->error =
			node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
		    }
		  other_packets++;
		  goto trace01;
		}

	      if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
		{
		  next1 = icmp_in2out_slow_path
		    (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
		     next1, now, thread_index, &s1);
		  icmp_packets++;
		  goto trace01;
		}
	    }
	  else
	    {
	      if (PREDICT_FALSE (proto1 == ~0))
		{
		  next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
		  goto trace01;
		}

	      if (ip4_is_fragment (ip1))
		{
		  next1 = SNAT_IN2OUT_NEXT_REASS;
		  fragments++;
		  goto trace01;
		}

	      if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
		{
		  next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
		  goto trace01;
		}
	    }

	  key1.addr = ip1->src_address;
	  key1.port = udp1->src_port;
	  key1.protocol = proto1;
	  key1.fib_index = rx_fib_index1;

	  kv1.key = key1.as_u64;

	  if (PREDICT_FALSE
	      (clib_bihash_search_8_8
	       (&sm->per_thread_data[thread_index].in2out, &kv1,
		&value1) != 0))
	    {
	      if (is_slow_path)
		{
		  if (is_output_feature)
		    {
		      if (PREDICT_FALSE (nat_not_translate_output_feature (sm,
									   ip1,
									   proto1,
									   udp1->src_port,
									   udp1->dst_port,
									   thread_index,
									   sw_if_index1)))
			goto trace01;
		    }
		  else
		    {
		      if (PREDICT_FALSE
			  (snat_not_translate
			   (sm, node, sw_if_index1, ip1, proto1,
			    rx_fib_index1, thread_index)))
			goto trace01;
		    }

		  next1 = slow_path (sm, b1, ip1, rx_fib_index1, &key1,
				     &s1, node, next1, thread_index, now);
		  if (PREDICT_FALSE (next1 == SNAT_IN2OUT_NEXT_DROP))
		    goto trace01;

		  if (PREDICT_FALSE (!s1))
		    goto trace01;
		}
	      else
		{
		  next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
		  goto trace01;
		}
	    }
	  else
	    s1 =
	      pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
				 value1.value);

	  b1->flags |= VNET_BUFFER_F_IS_NATED;

	  old_addr1 = ip1->src_address.as_u32;
	  ip1->src_address = s1->out2in.addr;
	  new_addr1 = ip1->src_address.as_u32;
	  if (!is_output_feature)
	    vnet_buffer (b1)->sw_if_index[VLIB_TX] = s1->out2in.fib_index;

	  sum1 = ip1->checksum;
	  sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
				 ip4_header_t,
				 src_address /* changed member */ );
	  ip1->checksum = ip_csum_fold (sum1);

	  if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
	    {
	      old_port1 = tcp1->src_port;
	      tcp1->src_port = s1->out2in.port;
	      new_port1 = tcp1->src_port;

	      sum1 = tcp1->checksum;
	      sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
				     ip4_header_t,
				     dst_address /* changed member */ );
	      sum1 = ip_csum_update (sum1, old_port1, new_port1,
				     ip4_header_t /* cheat */ ,
				     length /* changed member */ );
	      mss_clamping (sm, tcp1, &sum1);
	      tcp1->checksum = ip_csum_fold (sum1);
	      tcp_packets++;
	    }
	  else
	    {
	      old_port1 = udp1->src_port;
	      udp1->src_port = s1->out2in.port;
	      udp1->checksum = 0;
	      udp_packets++;
	    }

	  /* Accounting */
	  nat44_session_update_counters (s1, now,
					 vlib_buffer_length_in_chain (vm, b1),
					 thread_index);
	  /* Per-user LRU list maintenance */
	  nat44_session_update_lru (sm, s1, thread_index);
	trace01:

	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
			     && (b1->flags & VLIB_BUFFER_IS_TRACED)))
	    {
	      snat_in2out_trace_t *t =
		vlib_add_trace (vm, node, b1, sizeof (*t));
	      t->sw_if_index = sw_if_index1;
	      t->next_index = next1;
	      t->session_index = ~0;
	      if (s1)
		t->session_index =
		  s1 - sm->per_thread_data[thread_index].sessions;
	    }

	  pkts_processed += next1 == SNAT_IN2OUT_NEXT_LOOKUP;

	  /* verify speculative enqueues, maybe switch current next frame */
	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, bi1, next0, next1);
	}

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  u32 next0;
	  u32 sw_if_index0;
	  ip4_header_t *ip0;
	  ip_csum_t sum0;
	  u32 new_addr0, old_addr0;
	  u16 old_port0, new_port0;
	  udp_header_t *udp0;
	  tcp_header_t *tcp0;
	  icmp46_header_t *icmp0;
	  snat_session_key_t key0;
	  u32 rx_fib_index0;
	  u32 proto0;
	  snat_session_t *s0 = 0;
	  clib_bihash_kv_8_8_t kv0, value0;
	  u32 iph_offset0 = 0;

	  /* speculatively enqueue b0 to the current next frame */
	  bi0 = from[0];
	  to_next[0] = bi0;
	  from += 1;
	  to_next += 1;
	  n_left_from -= 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);
	  next0 = SNAT_IN2OUT_NEXT_LOOKUP;

	  if (is_output_feature)
	    iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;

	  ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
				  iph_offset0);

	  udp0 = ip4_next_header (ip0);
	  tcp0 = (tcp_header_t *) udp0;
	  icmp0 = (icmp46_header_t *) udp0;

	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
	  rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
				   sw_if_index0);

	  if (PREDICT_FALSE (ip0->ttl == 1))
	    {
	      vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
	      icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
					   ICMP4_time_exceeded_ttl_exceeded_in_transit,
					   0);
	      next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
	      goto trace0;
	    }

	  proto0 = ip_proto_to_snat_proto (ip0->protocol);

	  /* Next configured feature, probably ip4-lookup */
	  if (is_slow_path)
	    {
	      if (PREDICT_FALSE (proto0 == ~0))
		{
		  if (nat_in2out_sm_unknown_proto
		      (sm, b0, ip0, rx_fib_index0))
		    {
		      next0 = SNAT_IN2OUT_NEXT_DROP;
		      b0->error =
			node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
		    }
		  other_packets++;
		  goto trace0;
		}

	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
		{
		  next0 = icmp_in2out_slow_path
		    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
		     next0, now, thread_index, &s0);
		  icmp_packets++;
		  goto trace0;
		}
	    }
	  else
	    {
	      if (PREDICT_FALSE (proto0 == ~0))
		{
		  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
		  goto trace0;
		}

	      if (ip4_is_fragment (ip0))
		{
		  next0 = SNAT_IN2OUT_NEXT_REASS;
		  fragments++;
		  goto trace0;
		}

	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
		{
		  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
		  goto trace0;
		}
	    }

	  key0.addr = ip0->src_address;
	  key0.port = udp0->src_port;
	  key0.protocol = proto0;
	  key0.fib_index = rx_fib_index0;

	  kv0.key = key0.as_u64;

	  if (clib_bihash_search_8_8
	      (&sm->per_thread_data[thread_index].in2out, &kv0, &value0))
	    {
	      if (is_slow_path)
		{
		  if (is_output_feature)
		    {
		      if (PREDICT_FALSE (nat_not_translate_output_feature (sm,
									   ip0,
									   proto0,
									   udp0->src_port,
									   udp0->dst_port,
									   thread_index,
									   sw_if_index0)))
			goto trace0;
		    }
		  else
		    {
		      if (PREDICT_FALSE
			  (snat_not_translate
			   (sm, node, sw_if_index0, ip0, proto0,
			    rx_fib_index0, thread_index)))
			goto trace0;
		    }

		  next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
				     &s0, node, next0, thread_index, now);

		  if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
		    goto trace0;

		  if (PREDICT_FALSE (!s0))
		    goto trace0;
		}
	      else
		{
		  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
		  goto trace0;
		}
	    }
	  else
	    s0 =
	      pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
				 value0.value);

	  b0->flags |= VNET_BUFFER_F_IS_NATED;

	  old_addr0 = ip0->src_address.as_u32;
	  ip0->src_address = s0->out2in.addr;
	  new_addr0 = ip0->src_address.as_u32;
	  if (!is_output_feature)
	    vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;

	  sum0 = ip0->checksum;
	  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
				 ip4_header_t,
				 src_address /* changed member */ );
	  ip0->checksum = ip_csum_fold (sum0);

	  if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
	    {
	      old_port0 = tcp0->src_port;
	      tcp0->src_port = s0->out2in.port;
	      new_port0 = tcp0->src_port;

	      sum0 = tcp0->checksum;
	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
				     ip4_header_t,
				     dst_address /* changed member */ );
	      sum0 = ip_csum_update (sum0, old_port0, new_port0,
				     ip4_header_t /* cheat */ ,
				     length /* changed member */ );
	      mss_clamping (sm, tcp0, &sum0);
	      tcp0->checksum = ip_csum_fold (sum0);
	      tcp_packets++;
	    }
	  else
	    {
	      old_port0 = udp0->src_port;
	      udp0->src_port = s0->out2in.port;
	      udp0->checksum = 0;
	      udp_packets++;
	    }

	  /* Accounting */
	  nat44_session_update_counters (s0, now,
					 vlib_buffer_length_in_chain (vm, b0),
					 thread_index);
	  /* Per-user LRU list maintenance */
	  nat44_session_update_lru (sm, s0, thread_index);

	trace0:
	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
	    {
	      snat_in2out_trace_t *t =
		vlib_add_trace (vm, node, b0, sizeof (*t));
	      t->is_slow_path = is_slow_path;
	      t->sw_if_index = sw_if_index0;
	      t->next_index = next0;
	      t->session_index = ~0;
	      if (s0)
		t->session_index =
		  s0 - sm->per_thread_data[thread_index].sessions;
	    }

	  pkts_processed += next0 == SNAT_IN2OUT_NEXT_LOOKUP;

	  /* verify speculative enqueue, maybe switch current next frame */
	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, next0);
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  vlib_node_increment_counter (vm, stats_node_index,
			       SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
			       pkts_processed);
  vlib_node_increment_counter (vm, stats_node_index,
			       SNAT_IN2OUT_ERROR_TCP_PACKETS, tcp_packets);
  vlib_node_increment_counter (vm, stats_node_index,
			       SNAT_IN2OUT_ERROR_UDP_PACKETS, tcp_packets);
  vlib_node_increment_counter (vm, stats_node_index,
			       SNAT_IN2OUT_ERROR_ICMP_PACKETS, icmp_packets);
  vlib_node_increment_counter (vm, stats_node_index,
			       SNAT_IN2OUT_ERROR_OTHER_PACKETS,
			       other_packets);
  vlib_node_increment_counter (vm, stats_node_index,
			       SNAT_IN2OUT_ERROR_FRAGMENTS, fragments);

  return frame->n_vectors;
}

VLIB_NODE_FN (snat_in2out_node) (vlib_main_t * vm,
				 vlib_node_runtime_t * node,
				 vlib_frame_t * frame)
{
  return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */ ,
				     0);
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (snat_in2out_node) = {
  .name = "nat44-in2out",
  .vector_size = sizeof (u32),
  .format_trace = format_snat_in2out_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
  .error_strings = snat_in2out_error_strings,

  .runtime_data_bytes = sizeof (snat_runtime_t),

  .n_next_nodes = SNAT_IN2OUT_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes = {
    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
    [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
  },
};
/* *INDENT-ON* */

VLIB_NODE_FN (snat_in2out_output_node) (vlib_main_t * vm,
					vlib_node_runtime_t * node,
					vlib_frame_t * frame)
{
  return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */ ,
				     1);
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (snat_in2out_output_node) = {
  .name = "nat44-in2out-output",
  .vector_size = sizeof (u32),
  .format_trace = format_snat_in2out_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
  .error_strings = snat_in2out_error_strings,

  .runtime_data_bytes = sizeof (snat_runtime_t),

  .n_next_nodes = SNAT_IN2OUT_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes = {
    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
    [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
    [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
  },
};
/* *INDENT-ON* */

VLIB_NODE_FN (snat_in2out_slowpath_node) (vlib_main_t * vm,
					  vlib_node_runtime_t * node,
					  vlib_frame_t * frame)
{
  return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */ ,
				     0);
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
  .name = "nat44-in2out-slowpath",
  .vector_size = sizeof (u32),
  .format_trace = format_snat_in2out_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
  .error_strings = snat_in2out_error_strings,

  .runtime_data_bytes = sizeof (snat_runtime_t),

  .n_next_nodes = SNAT_IN2OUT_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes = {
    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
    [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
  },
};
/* *INDENT-ON* */

VLIB_NODE_FN (snat_in2out_output_slowpath_node) (vlib_main_t * vm,
						 vlib_node_runtime_t * node,
						 vlib_frame_t * frame)
{
  return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */ ,
				     1);
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (snat_in2out_output_slowpath_node) = {
  .name = "nat44-in2out-output-slowpath",
  .vector_size = sizeof (u32),
  .format_trace = format_snat_in2out_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
  .error_strings = snat_in2out_error_strings,

  .runtime_data_bytes = sizeof (snat_runtime_t),

  .n_next_nodes = SNAT_IN2OUT_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes = {
    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
    [SNAT_IN2OUT_NEXT_LOOKUP] = "interface-output",
    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-output-slowpath",
    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
    [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
  },
};
/* *INDENT-ON* */

VLIB_NODE_FN (nat44_in2out_reass_node) (vlib_main_t * vm,
					vlib_node_runtime_t * node,
					vlib_frame_t * frame)
{
  u32 n_left_from, *from, *to_next;
  snat_in2out_next_t next_index;
  u32 pkts_processed = 0, cached_fragments = 0;
  snat_main_t *sm = &snat_main;
  f64 now = vlib_time_now (vm);
  u32 thread_index = vm->thread_index;
  snat_main_per_thread_data_t *per_thread_data =
    &sm->per_thread_data[thread_index];
  u32 *fragments_to_drop = 0;
  u32 *fragments_to_loopback = 0;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0, sw_if_index0, proto0, rx_fib_index0, new_addr0, old_addr0;
	  vlib_buffer_t *b0;
	  u32 next0;
	  u8 cached0 = 0;
	  ip4_header_t *ip0;
	  nat_reass_ip4_t *reass0;
	  udp_header_t *udp0;
	  tcp_header_t *tcp0;
	  icmp46_header_t *icmp0;
	  snat_session_key_t key0;
	  clib_bihash_kv_8_8_t kv0, value0;
	  snat_session_t *s0 = 0;
	  u16 old_port0, new_port0;
	  ip_csum_t sum0;

	  /* speculatively enqueue b0 to the current next frame */
	  bi0 = from[0];
	  to_next[0] = bi0;
	  from += 1;
	  to_next += 1;
	  n_left_from -= 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);
	  next0 = SNAT_IN2OUT_NEXT_LOOKUP;

	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
	  rx_fib_index0 =
	    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
						 sw_if_index0);

	  if (PREDICT_FALSE (nat_reass_is_drop_frag (0)))
	    {
	      next0 = SNAT_IN2OUT_NEXT_DROP;
	      b0->error = node->errors[SNAT_IN2OUT_ERROR_DROP_FRAGMENT];
	      goto trace0;
	    }

	  ip0 = (ip4_header_t *) vlib_buffer_get_current (b0);
	  udp0 = ip4_next_header (ip0);
	  tcp0 = (tcp_header_t *) udp0;
	  icmp0 = (icmp46_header_t *) udp0;
	  proto0 = ip_proto_to_snat_proto (ip0->protocol);

	  reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
						 ip0->dst_address,
						 ip0->fragment_id,
						 ip0->protocol,
						 1, &fragments_to_drop);

	  if (PREDICT_FALSE (!reass0))
	    {
	      next0 = SNAT_IN2OUT_NEXT_DROP;
	      b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_REASS];
	      nat_log_notice ("maximum reassemblies exceeded");
	      goto trace0;
	    }

	  if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
	    {
	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
		{
		  next0 = icmp_in2out_slow_path
		    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
		     next0, now, thread_index, &s0);

		  if (PREDICT_TRUE (next0 != SNAT_IN2OUT_NEXT_DROP))
		    {
		      if (s0)
			reass0->sess_index = s0 - per_thread_data->sessions;
		      else
			reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
		      nat_ip4_reass_get_frags (reass0,
					       &fragments_to_loopback);
		    }

		  goto trace0;
		}

	      key0.addr = ip0->src_address;
	      key0.port = udp0->src_port;
	      key0.protocol = proto0;
	      key0.fib_index = rx_fib_index0;
	      kv0.key = key0.as_u64;

	      if (clib_bihash_search_8_8
		  (&per_thread_data->in2out, &kv0, &value0))
		{
		  if (PREDICT_FALSE
		      (snat_not_translate
		       (sm, node, sw_if_index0, ip0, proto0, rx_fib_index0,
			thread_index)))
		    goto trace0;

		  next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
				     &s0, node, next0, thread_index, now);

		  if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
		    goto trace0;

		  if (PREDICT_FALSE (!s0))
		    goto trace0;

		  reass0->sess_index = s0 - per_thread_data->sessions;
		}
	      else
		{
		  s0 = pool_elt_at_index (per_thread_data->sessions,
					  value0.value);
		  reass0->sess_index = value0.value;
		}
	      nat_ip4_reass_get_frags (reass0, &fragments_to_loopback);
	    }
	  else
	    {
	      if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
		{
		  if (nat_ip4_reass_add_fragment
		      (thread_index, reass0, bi0, &fragments_to_drop))
		    {
		      b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_FRAG];
		      nat_log_notice
			("maximum fragments per reassembly exceeded");
		      next0 = SNAT_IN2OUT_NEXT_DROP;
		      goto trace0;
		    }
		  cached0 = 1;
		  goto trace0;
		}
	      s0 = pool_elt_at_index (per_thread_data->sessions,
				      reass0->sess_index);
	    }

	  old_addr0 = ip0->src_address.as_u32;
	  ip0->src_address = s0->out2in.addr;
	  new_addr0 = ip0->src_address.as_u32;
	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;

	  sum0 = ip0->checksum;
	  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
				 ip4_header_t,
				 src_address /* changed member */ );
	  ip0->checksum = ip_csum_fold (sum0);

	  if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
	    {
	      if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
		{
		  old_port0 = tcp0->src_port;
		  tcp0->src_port = s0->out2in.port;
		  new_port0 = tcp0->src_port;

		  sum0 = tcp0->checksum;
		  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
					 ip4_header_t,
					 dst_address /* changed member */ );
		  sum0 = ip_csum_update (sum0, old_port0, new_port0,
					 ip4_header_t /* cheat */ ,
					 length /* changed member */ );
		  tcp0->checksum = ip_csum_fold (sum0);
		}
	      else
		{
		  old_port0 = udp0->src_port;
		  udp0->src_port = s0->out2in.port;
		  udp0->checksum = 0;
		}
	    }

	  /* Hairpinning */
	  nat44_reass_hairpinning (sm, b0, ip0, s0->out2in.port,
				   s0->ext_host_port, proto0, 0);

	  /* Accounting */
	  nat44_session_update_counters (s0, now,
					 vlib_buffer_length_in_chain (vm, b0),
					 thread_index);
	  /* Per-user LRU list maintenance */
	  nat44_session_update_lru (sm, s0, thread_index);

	trace0:
	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
	    {
	      nat44_reass_trace_t *t =
		vlib_add_trace (vm, node, b0, sizeof (*t));
	      t->cached = cached0;
	      t->sw_if_index = sw_if_index0;
	      t->next_index = next0;
	    }

	  if (cached0)
	    {
	      n_left_to_next++;
	      to_next--;
	      cached_fragments++;
	    }
	  else
	    {
	      pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;

	      /* verify speculative enqueue, maybe switch current next frame */
	      vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
					       to_next, n_left_to_next,
					       bi0, next0);
	    }

	  if (n_left_from == 0 && vec_len (fragments_to_loopback))
	    {
	      from = vlib_frame_vector_args (frame);
	      u32 len = vec_len (fragments_to_loopback);
	      if (len <= VLIB_FRAME_SIZE)
		{
		  clib_memcpy_fast (from, fragments_to_loopback,
				    sizeof (u32) * len);
		  n_left_from = len;
		  vec_reset_length (fragments_to_loopback);
		}
	      else
		{
		  clib_memcpy_fast (from, fragments_to_loopback +
				    (len - VLIB_FRAME_SIZE),
				    sizeof (u32) * VLIB_FRAME_SIZE);
		  n_left_from = VLIB_FRAME_SIZE;
		  _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
		}
	    }
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  vlib_node_increment_counter (vm, sm->in2out_reass_node_index,
			       SNAT_IN2OUT_ERROR_PROCESSED_FRAGMENTS,
			       pkts_processed);
  vlib_node_increment_counter (vm, sm->in2out_reass_node_index,
			       SNAT_IN2OUT_ERROR_CACHED_FRAGMENTS,
			       cached_fragments);

  nat_send_all_to_node (vm, fragments_to_drop, node,
			&node->errors[SNAT_IN2OUT_ERROR_DROP_FRAGMENT],
			SNAT_IN2OUT_NEXT_DROP);

  vec_free (fragments_to_drop);
  vec_free (fragments_to_loopback);
  return frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (nat44_in2out_reass_node) = {
  .name = "nat44-in2out-reass",
  .vector_size = sizeof (u32),
  .format_trace = format_nat44_reass_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
  .error_strings = snat_in2out_error_strings,

  .n_next_nodes = SNAT_IN2OUT_N_NEXT,
  .next_nodes = {
    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
    [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
  },
};
/* *INDENT-ON* */

VLIB_NODE_FN (snat_in2out_fast_node) (vlib_main_t * vm,
				      vlib_node_runtime_t * node,
				      vlib_frame_t * frame)
{
  u32 n_left_from, *from, *to_next;
  snat_in2out_next_t next_index;
  u32 pkts_processed = 0;
  snat_main_t *sm = &snat_main;
  u32 stats_node_index;

  stats_node_index = sm->in2out_fast_node_index;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  u32 next0;
	  u32 sw_if_index0;
	  ip4_header_t *ip0;
	  ip_csum_t sum0;
	  u32 new_addr0, old_addr0;
	  u16 old_port0, new_port0;
	  udp_header_t *udp0;
	  tcp_header_t *tcp0;
	  icmp46_header_t *icmp0;
	  snat_session_key_t key0, sm0;
	  u32 proto0;
	  u32 rx_fib_index0;

	  /* speculatively enqueue b0 to the current next frame */
	  bi0 = from[0];
	  to_next[0] = bi0;
	  from += 1;
	  to_next += 1;
	  n_left_from -= 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);
	  next0 = SNAT_IN2OUT_NEXT_LOOKUP;

	  ip0 = vlib_buffer_get_current (b0);
	  udp0 = ip4_next_header (ip0);
	  tcp0 = (tcp_header_t *) udp0;
	  icmp0 = (icmp46_header_t *) udp0;

	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
	  rx_fib_index0 =
	    ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);

	  if (PREDICT_FALSE (ip0->ttl == 1))
	    {
	      vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
	      icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
					   ICMP4_time_exceeded_ttl_exceeded_in_transit,
					   0);
	      next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
	      goto trace0;
	    }

	  proto0 = ip_proto_to_snat_proto (ip0->protocol);

	  if (PREDICT_FALSE (proto0 == ~0))
	    goto trace0;

	  if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
	    {
	      next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0,
				   rx_fib_index0, node, next0, ~0, 0, 0);
	      goto trace0;
	    }

	  key0.addr = ip0->src_address;
	  key0.protocol = proto0;
	  key0.port = udp0->src_port;
	  key0.fib_index = rx_fib_index0;

	  if (snat_static_mapping_match (sm, key0, &sm0, 0, 0, 0, 0, 0, 0))
	    {
	      b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
	      next0 = SNAT_IN2OUT_NEXT_DROP;
	      goto trace0;
	    }

	  new_addr0 = sm0.addr.as_u32;
	  new_port0 = sm0.port;
	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
	  old_addr0 = ip0->src_address.as_u32;
	  ip0->src_address.as_u32 = new_addr0;

	  sum0 = ip0->checksum;
	  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
				 ip4_header_t,
				 src_address /* changed member */ );
	  ip0->checksum = ip_csum_fold (sum0);

	  if (PREDICT_FALSE (new_port0 != udp0->dst_port))
	    {
	      if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
		{
		  old_port0 = tcp0->src_port;
		  tcp0->src_port = new_port0;

		  sum0 = tcp0->checksum;
		  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
					 ip4_header_t,
					 dst_address /* changed member */ );
		  sum0 = ip_csum_update (sum0, old_port0, new_port0,
					 ip4_header_t /* cheat */ ,
					 length /* changed member */ );
		  mss_clamping (sm, tcp0, &sum0);
		  tcp0->checksum = ip_csum_fold (sum0);
		}
	      else
		{
		  old_port0 = udp0->src_port;
		  udp0->src_port = new_port0;
		  udp0->checksum = 0;
		}
	    }
	  else
	    {
	      if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
		{
		  sum0 = tcp0->checksum;
		  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
					 ip4_header_t,
					 dst_address /* changed member */ );
		  mss_clamping (sm, tcp0, &sum0);
		  tcp0->checksum = ip_csum_fold (sum0);
		}
	    }

	  /* Hairpinning */
	  snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0, 0);

	trace0:
	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
	    {
	      snat_in2out_trace_t *t =
		vlib_add_trace (vm, node, b0, sizeof (*t));
	      t->sw_if_index = sw_if_index0;
	      t->next_index = next0;
	    }

	  pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;

	  /* verify speculative enqueue, maybe switch current next frame */
	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, next0);
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  vlib_node_increment_counter (vm, stats_node_index,
			       SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
			       pkts_processed);
  return frame->n_vectors;
}


/* *INDENT-OFF* */
VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
  .name = "nat44-in2out-fast",
  .vector_size = sizeof (u32),
  .format_trace = format_snat_in2out_fast_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
  .error_strings = snat_in2out_error_strings,

  .runtime_data_bytes = sizeof (snat_runtime_t),

  .n_next_nodes = SNAT_IN2OUT_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes = {
    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
    [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
    [SNAT_IN2OUT_NEXT_REASS] = "nat44-in2out-reass",
  },
};
/* *INDENT-ON* */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */