index : vpp	master stable/1606 stable/1609 stable/1701 stable/1704 stable/1707 stable/1710 stable/1801 stable/1804 stable/1807 stable/1810 stable/1901 stable/1904 stable/1908 stable/2001 stable/2005 stable/2009 stable/2101 stable/2106 stable/2110 stable/2202 stable/2206 stable/2210 stable/2302 stable/2306 stable/2310 stable/2402 stable/2406 stable/test
	Vector Packet Processing	Grokmirror user

aboutsummaryrefslogtreecommitdiffstats

log msg author committer range

path: root/test/test_nat.py

Age	Commit message (Expand)	Author	Files	Lines
2019-03-15	Revert "API: Cleanup APIs interface.api"	Ole Trøan	1	-17/+18
2019-03-15	API: Cleanup APIs interface.api	Jakub Grajciar	1	-18/+17
2019-03-11	vpp_papi_provider: Remove more wrapper functions.	Ole Troan	1	-12/+11
2019-03-11	VPP-1508: Tests: Fix vpp_api struct.error under py3.	Paul Vinciguerra	1	-9/+9
2019-03-11	VPP-1508: Use scapy.compat to manage packet level library differences.	Paul Vinciguerra	1	-41/+44
2019-03-11	Tests: use self.assertNotIn().	Paul Vinciguerra	1	-2/+2
2019-03-06	test framework: vpp_papi_provider.py - further cleanup	Ole Troan	1	-23/+24
2019-03-04	test framework: Fix wrapper functions to match API message names.	Ole Troan	1	-31/+34
2019-03-04	test framework: add factory function and default parameters	Ole Troan	1	-4/+4
2019-02-27	NAT44: active-passive HA (VPP-1571)	Matus Fabian	1	-2/+351
2019-01-30	Use IP and MAC API types for neighbors	Neale Ranns	1	-30/+44
2019-01-18	VTL: Don't swallow exceptions from syslog_rfc5424_parser	Paul Vinciguerra	1	-6/+11
2018-12-21	MAP: Convert from DPO to input feature.	Jon Loeliger	1	-2/+1
2018-12-20	NAT: total users and sessions gauges (VPP-1484)	Matus Fabian	1	-0/+33
2018-12-20	Tests: Cleanup @skip decorator.	Paul Vinciguerra	1	-10/+10
2018-12-18	NAT44: nat44_add_del_lb_static_mapping enhancements (VPP-1514)	Matus Fabian	1	-0/+60
2018-12-18	PAPI: Add MACAddress object wrapper for vl_api_mac_address_t	Ole Troan	1	-7/+7
2018-12-14	NAT: counters (VPP-1484)	Matus Fabian	1	-1/+115
2018-12-10	Test framework: StringIO fixes for Python3	Ole Troan	1	-6/+6
2018-11-30	Tests: Fix traceback.	Paul Vinciguerra	1	-15/+14
2018-11-29	NAT: syslog - sessions logging (VPP-1139)	Matus Fabian	1	-1/+173
2018-11-26	Python3 tests: Fix asserts.	Paul Vinciguerra	1	-4/+4
2018-11-23	NAT44: improve expired sessions reuse (VPP-1503)	Matus Fabian	1	-17/+2
2018-11-22	MAP: Use explicit address/prefix types in API	Ole Troan	1	-0/+2
2018-11-22	NAT44: Apply transitory timeout on TCP RST (VPP-1494)	Matus Fabian	1	-0/+51
2018-11-20	NAT44: fix virtual fragmentation reassembly in forwarding mode (VPP-1501)	Matus Fabian	1	-0/+26
2018-11-19	NAT44: fix bug in TCP close with output-feature interface (VPP-1493)	Matus Fabian	1	-0/+82
2018-10-19	NAT44: fix ICMP virtual fragmentation reassembly (VPP-1466)	Matus Fabian	1	-109/+22
2018-10-12	NAT44: identity NAT fix (VPP-1441)	Matus Fabian	1	-0/+4
2018-10-08	NAT44: do not create session record for identity mapping (VPP-1439)	Matus Fabian	1	-0/+3
2018-09-24	NAT44: endpoint-dependent mode session timeout improvement (VPP-1423)	Matus Fabian	1	-0/+10
2018-09-20	NAT44 virtual fragmentation reassembly for endpoint-dependent mode (VPP-1325)	Juraj Sloboda	1	-16/+518
2018-09-13	NAT: TCP MSS clamping	Matus Fabian	1	-0/+52
2018-09-06	NAT: fix maximum out of order fragments (VPP-1399)	Matus Fabian	1	-6/+8
2018-09-06	NAT: test cleanup (VPP-1252)	Matus Fabian	1	-30/+11
2018-09-04	NAT: add support for configurable port range (VPP-1346)	Matus Fabian	1	-3/+32
2018-09-03	NAT44: client-IP based session affinity for load-balancing (VPP-1297)	Matus Fabian	1	-0/+61
2018-08-27	NAT44: add support for session timeout (VPP-1272)	Matus Fabian	1	-40/+185
2018-08-22	NAT: update nat_show_config_reply API (VPP-1403)	Matus Fabian	1	-0/+12
2018-08-15	NAT44: fix next_src_nat (VPP-1384)	Matus Fabian	1	-0/+57
2018-08-15	NAT64: fix TCP session expire (VPP-1390)	Matus Fabian	1	-3/+3
2018-08-09	NAT44: delete user with zero sessions (VPP-1282)	Matus Fabian	1	-0/+12
2018-08-02	NAT44: LB NAT - local backends in multiple VRFs (VPP-1345)	Matus Fabian	1	-9/+16
2018-07-23	NAT44: fix forwarding feature bug (VPP-1349)	Matus Fabian	1	-16/+3
2018-07-10	NAT44: multiple outside FIB tables (VPP-1314)	Matus Fabian	1	-21/+442
2018-07-10	Do not translate packets destined for NAT64 inside interface (VPP-1331)	Juraj Sloboda	1	-2/+60
2018-06-26	NAT44: fix nat44_ed_not_translate_output_feature (VPP-1329)	Matus Fabian	1	-0/+25
2018-06-15	NAT44: endpoint dependent mode (VPP-1273)	Matus Fabian	1	-936/+1105
2018-05-28	NAT44: code cleanup and refactor (VPP-1285)	Matus Fabian	1	-136/+150
2018-05-17	NAT44: nat44_del_session and nat44_user_session_details API update (VPP-1271)	Matus Fabian	1	-24/+54

• [next]

© 2016 FD.io a Linux Foundation Collaborative Project. All Rights Reserved.

Linux Foundation is a registered trademark of The Linux Foundation. Linux is a registered trademark of Linus Torvalds.

Please see our privacy policy and terms of use

/*
 * Copyright (c) 2015 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.
 */
/*
  Copyright (c) 2001-2005 Eliot Dresselhaus

  Permission is hereby granted, free of charge, to any person obtaining
  a copy of this software and associated documentation files (the
  "Software"), to deal in the Software without restriction, including
  without limitation the rights to use, copy, modify, merge, publish,
  distribute, sublicense, and/or sell copies of the Software, and to
  permit persons to whom the Software is furnished to do so, subject to
  the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include <vppinfra/hash.h>
#include <vppinfra/error.h>
#include <vppinfra/mem.h>
#include <vppinfra/byte_order.h>	/* for clib_arch_is_big_endian */

always_inline void
zero_pair (hash_t * h, hash_pair_t * p)
{
  clib_memset (p, 0, hash_pair_bytes (h));
}

always_inline void
init_pair (hash_t * h, hash_pair_t * p)
{
  clib_memset (p->value, ~0, hash_value_bytes (h));
}

always_inline hash_pair_union_t *
get_pair (void *v, uword i)
{
  hash_t *h = hash_header (v);
  hash_pair_t *p;
  ASSERT (i < vec_len (v));
  p = v;
  p += i << h->log2_pair_size;
  return (hash_pair_union_t *) p;
}

always_inline void
set_is_user (void *v, uword i, uword is_user)
{
  hash_t *h = hash_header (v);
  uword i0 = i / BITS (h->is_user[0]);
  uword i1 = (uword) 1 << (i % BITS (h->is_user[0]));
  if (is_user)
    h->is_user[i0] |= i1;
  else
    h->is_user[i0] &= ~i1;
}

static u8 *hash_format_pair_default (u8 * s, va_list * args);

#if uword_bits == 64

static inline u64
zap64 (u64 x, word n)
{
#define _(n) (((u64) 1 << (u64) (8*(n))) - (u64) 1)
  static u64 masks_little_endian[] = {
    0, _(1), _(2), _(3), _(4), _(5), _(6), _(7),
  };
  static u64 masks_big_endian[] = {
    0, ~_(7), ~_(6), ~_(5), ~_(4), ~_(3), ~_(2), ~_(1),
  };
#undef _
  if (clib_arch_is_big_endian)
    return x & masks_big_endian[n];
  else
    return x & masks_little_endian[n];
}

/**
 * make address-sanitizer skip this:
 * clib_mem_unaligned + zap64 casts its input as u64, computes a mask
 * according to the input length, and returns the casted maked value.
 * Therefore all the 8 Bytes of the u64 are systematically read, which
 * rightfully causes address-sanitizer to raise an error on smaller inputs.
 *
 * However the invalid Bytes are discarded within zap64(), which is why
 * this can be silenced safely.
 *
 * The above is true *unless* the extra bytes cross a page boundary
 * into unmapped or no-access space, hence the boundary crossing check.
 */
static inline u64
hash_memory64 (void *p, word n_bytes, u64 state)
{
  u64 *q = p;
  u64 a, b, c, n;
  int page_boundary_crossing;
  u64 start_addr, end_addr;
  union
  {
    u8 as_u8[8];
    u64 as_u64;
  } tmp;

  /*
   * If the request crosses a 4k boundary, it's not OK to assume
   * that the zap64 game is safe. 4k is the minimum known page size.
   */
  start_addr = (u64) p;
  end_addr = start_addr + n_bytes + 7;
  page_boundary_crossing = (start_addr >> 12) != (end_addr >> 12);

  a = b = 0x9e3779b97f4a7c13LL;
  c = state;
  n = n_bytes;

  while (n >= 3 * sizeof (u64))
    {
      a += clib_mem_unaligned (q + 0, u64);
      b += clib_mem_unaligned (q + 1, u64);
      c += clib_mem_unaligned (q + 2, u64);
      hash_mix64 (a, b, c);
      n -= 3 * sizeof (u64);
      q += 3;
    }

  c += n_bytes;
  switch (n / sizeof (u64))
    {
    case 2:
      a += clib_mem_unaligned (q + 0, u64);
      b += clib_mem_unaligned (q + 1, u64);
      if (n % sizeof (u64))
	{
	  if (PREDICT_TRUE (page_boundary_crossing == 0))
	    c +=
	      zap64 (CLIB_MEM_OVERFLOW
		     (clib_mem_unaligned (q + 2, u64), q + 2, sizeof (u64)),
		     n % sizeof (u64)) << 8;
	  else
	    {
	      clib_memcpy_fast (tmp.as_u8, q + 2, n % sizeof (u64));
	      c += zap64 (tmp.as_u64, n % sizeof (u64)) << 8;
	    }
	}
      break;

    case 1:
      a += clib_mem_unaligned (q + 0, u64);
      if (n % sizeof (u64))
	{
	  if (PREDICT_TRUE (page_boundary_crossing == 0))
	    b +=
	      zap64 (CLIB_MEM_OVERFLOW
		     (clib_mem_unaligned (q + 1, u64), q + 1, sizeof (u64)),
		     n % sizeof (u64));
	  else
	    {
	      clib_memcpy_fast (tmp.as_u8, q + 1, n % sizeof (u64));
	      b += zap64 (tmp.as_u64, n % sizeof (u64));
	    }
	}
      break;

    case 0:
      if (n % sizeof (u64))
	{
	  if (PREDICT_TRUE (page_boundary_crossing == 0))
	    a +=
	      zap64 (CLIB_MEM_OVERFLOW
		     (clib_mem_unaligned (q + 0, u64), q + 0, sizeof (u64)),
		     n % sizeof (u64));
	  else
	    {
	      clib_memcpy_fast (tmp.as_u8, q, n % sizeof (u64));
	      a += zap64 (tmp.as_u64, n % sizeof (u64));
	    }
	}
      break;
    }

  hash_mix64 (a, b, c);

  return c;
}

#else /* if uword_bits == 64 */

static inline u32
zap32 (u32 x, word n)
{
#define _(n) (((u32) 1 << (u32) (8*(n))) - (u32) 1)
  static u32 masks_little_endian[] = {
    0, _(1), _(2), _(3),
  };
  static u32 masks_big_endian[] = {
    0, ~_(3), ~_(2), ~_(1),
  };
#undef _
  if (clib_arch_is_big_endian)
    return x & masks_big_endian[n];
  else
    return x & masks_little_endian[n];
}

static inline u32
hash_memory32 (void *p, word n_bytes, u32 state)
{
  u32 *q = p;
  u32 a, b, c, n;

  a = b = 0x9e3779b9;
  c = state;
  n = n_bytes;

  while (n >= 3 * sizeof (u32))
    {
      a += clib_mem_unaligned (q + 0, u32);
      b += clib_mem_unaligned (q + 1, u32);
      c += clib_mem_unaligned (q + 2, u32);
      hash_mix32 (a, b, c);
      n -= 3 * sizeof (u32);
      q += 3;
    }

  c += n_bytes;
  switch (n / sizeof (u32))
    {
    case 2:
      a += clib_mem_unaligned (q + 0, u32);
      b += clib_mem_unaligned (q + 1, u32);
      if (n % sizeof (u32))
	c += zap32 (clib_mem_unaligned (q + 2, u32), n % sizeof (u32)) << 8;
      break;

    case 1:
      a += clib_mem_unaligned (q + 0, u32);
      if (n % sizeof (u32))
	b += zap32 (clib_mem_unaligned (q + 1, u32), n % sizeof (u32));
      break;

    case 0:
      if (n % sizeof (u32))
	a += zap32 (clib_mem_unaligned (q + 0, u32), n % sizeof (u32));
      break;
    }

  hash_mix32 (a, b, c);

  return c;
}
#endif

__clib_export uword
hash_memory (void *p, word n_bytes, uword state)
{
  uword *q = p;

#if uword_bits == 64
  return hash_memory64 (q, n_bytes, state);
#else
  return hash_memory32 (q, n_bytes, state);
#endif
}

#if uword_bits == 64
always_inline uword
hash_uword (uword x)
{
  u64 a, b, c;

  a = b = 0x9e3779b97f4a7c13LL;
  c = 0;
  a += x;
  hash_mix64 (a, b, c);
  return c;
}
#else
always_inline uword
hash_uword (uword x)
{
  u32 a, b, c;

  a = b = 0x9e3779b9;
  c = 0;
  a += x;
  hash_mix32 (a, b, c);
  return c;
}
#endif

/* Call sum function.  Hash code will be sum function value
   modulo the prime length of the hash table. */
always_inline uword
key_sum (hash_t * h, uword key)
{
  uword sum;
  switch (pointer_to_uword ((void *) h->key_sum))
    {
    case KEY_FUNC_NONE:
      sum = hash_uword (key);
      break;

    case KEY_FUNC_POINTER_UWORD:
      sum = hash_uword (*uword_to_pointer (key, uword *));
      break;

    case KEY_FUNC_POINTER_U32:
      sum = hash_uword (*uword_to_pointer (key, u32 *));
      break;

    case KEY_FUNC_STRING:
      sum = string_key_sum (h, key);
      break;

    case KEY_FUNC_MEM:
      sum = mem_key_sum (h, key);
      break;

    default:
      sum = h->key_sum (h, key);
      break;
    }

  return sum;
}

always_inline uword
key_equal1 (hash_t * h, uword key1, uword key2, uword e)
{
  switch (pointer_to_uword ((void *) h->key_equal))
    {
    case KEY_FUNC_NONE:
      break;

    case KEY_FUNC_POINTER_UWORD:
      e =
	*uword_to_pointer (key1, uword *) == *uword_to_pointer (key2,
								uword *);
      break;

    case KEY_FUNC_POINTER_U32:
      e = *uword_to_pointer (key1, u32 *) == *uword_to_pointer (key2, u32 *);
      break;

    case KEY_FUNC_STRING:
      e = string_key_equal (h, key1, key2);
      break;

    case KEY_FUNC_MEM:
      e = mem_key_equal (h, key1, key2);
      break;

    default:
      e = h->key_equal (h, key1, key2);
      break;
    }
  return e;
}

/* Compares two keys: returns 1 if equal, 0 if not. */
always_inline uword
key_equal (hash_t * h, uword key1, uword key2)
{
  uword e = key1 == key2;
  if (CLIB_DEBUG > 0 && key1 == key2)
    ASSERT (key_equal1 (h, key1, key2, e));
  if (!e)
    e = key_equal1 (h, key1, key2, e);
  return e;
}

static hash_pair_union_t *
get_indirect (void *v, hash_pair_indirect_t * pi, uword key)
{
  hash_t *h = hash_header (v);
  hash_pair_t *p0, *p1;

  p0 = p1 = pi->pairs;
  if (h->log2_pair_size > 0)
    p1 = hash_forward (h, p0, indirect_pair_get_len (pi));
  else
    p1 += vec_len (p0);

  while (p0 < p1)
    {
      if (key_equal (h, p0->key, key))
	return (hash_pair_union_t *) p0;
      p0 = hash_forward1 (h, p0);
    }

  return (hash_pair_union_t *) 0;
}

static hash_pair_union_t *
set_indirect_is_user (void *v, uword i, hash_pair_union_t * p, uword key)
{
  hash_t *h = hash_header (v);
  hash_pair_t *q;
  hash_pair_indirect_t *pi = &p->indirect;
  uword log2_bytes = 0;

  if (h->log2_pair_size == 0)
    q = vec_new (hash_pair_t, 2);
  else
    {
      log2_bytes = 1 + hash_pair_log2_bytes (h);
      q = clib_mem_alloc (1ULL << log2_bytes);
    }
  clib_memcpy_fast (q, &p->direct, hash_pair_bytes (h));

  pi->pairs = q;
  if (h->log2_pair_size > 0)
    indirect_pair_set (pi, log2_bytes, 2);

  set_is_user (v, i, 0);

  /* First element is used by existing pair, second will be used by caller. */
  q = hash_forward1 (h, q);
  q->key = key;
  init_pair (h, q);
  return (hash_pair_union_t *) q;
}

static hash_pair_union_t *
set_indirect (void *v, hash_pair_indirect_t * pi, uword key,
	      uword * found_key)
{
  hash_t *h = hash_header (v);
  hash_pair_t *new_pair;
  hash_pair_union_t *q;

  q = get_indirect (v, pi, key);
  if (q)
    {
      *found_key = 1;
      return q;
    }

  if (h->log2_pair_size == 0)
    vec_add2 (pi->pairs, new_pair, 1);
  else
    {
      uword len, new_len, log2_bytes;

      len = indirect_pair_get_len (pi);
      log2_bytes = indirect_pair_get_log2_bytes (pi);

      new_len = len + 1;
      if (new_len * hash_pair_bytes (h) > (1ULL << log2_bytes))
	{
	  pi->pairs = clib_mem_realloc (pi->pairs,
					1ULL << (log2_bytes + 1),
					1ULL << log2_bytes);
	  log2_bytes++;
	}

      indirect_pair_set (pi, log2_bytes, new_len);
      new_pair = pi->pairs + (len << h->log2_pair_size);
    }
  new_pair->key = key;
  init_pair (h, new_pair);
  *found_key = 0;
  return (hash_pair_union_t *) new_pair;
}

static void
unset_indirect (void *v, uword i, hash_pair_t * q)
{
  hash_t *h = hash_header (v);
  hash_pair_union_t *p = get_pair (v, i);
  hash_pair_t *e;
  hash_pair_indirect_t *pi = &p->indirect;
  uword len, is_vec;

  is_vec = h->log2_pair_size == 0;

  ASSERT (!hash_is_user (v, i));
  len = is_vec ? vec_len (pi->pairs) : indirect_pair_get_len (pi);
  e = hash_forward (h, pi->pairs, len - 1);
  ASSERT (q >= pi->pairs && q <= e);

  /* We have two or fewer pairs and we are delete one pair.
     Make indirect pointer direct and free indirect memory. */
  if (len <= 2)
    {
      hash_pair_t *r = pi->pairs;

      if (len == 2)
	{
	  clib_memcpy_fast (p, q == r ? hash_forward1 (h, r) : r,
			    hash_pair_bytes (h));
	  set_is_user (v, i, 1);
	}
      else
	zero_pair (h, &p->direct);

      if (is_vec)
	vec_free (r);
      else if (r)
	clib_mem_free (r);
    }
  else
    {
      /* If deleting a pair we need to keep non-null pairs together. */
      if (q < e)
	clib_memcpy_fast (q, e, hash_pair_bytes (h));
      else
	zero_pair (h, q);
      if (is_vec)
	_vec_len (pi->pairs) -= 1;
      else
	indirect_pair_set (pi, indirect_pair_get_log2_bytes (pi), len - 1);
    }
}

enum lookup_opcode
{
  GET = 1,
  SET = 2,
  UNSET = 3,
};

static hash_pair_t *
lookup (void *v, uword key, enum lookup_opcode op,
	void *new_value, void *old_value)
{
  hash_t *h = hash_header (v);
  hash_pair_union_t *p = 0;
  uword found_key = 0;
  uword value_bytes;
  uword i;

  if (!v)
    return 0;

  i = key_sum (h, key) & (_vec_len (v) - 1);
  p = get_pair (v, i);
  value_bytes = hash_value_bytes (h);

  if (hash_is_user (v, i))
    {
      found_key = key_equal (h, p->direct.key, key);
      if (found_key)
	{
	  if (op == UNSET)
	    {
	      set_is_user (v, i, 0);
	      if (old_value && value_bytes)
		clib_memcpy_fast (old_value, p->direct.value, value_bytes);
	      zero_pair (h, &p->direct);
	    }
	}
      else
	{
	  if (op == SET)
	    p = set_indirect_is_user (v, i, p, key);
	  else
	    p = 0;
	}
    }
  else
    {
      hash_pair_indirect_t *pi = &p->indirect;

      if (op == SET)
	{
	  if (!pi->pairs)
	    {
	      p->direct.key = key;
	      set_is_user (v, i, 1);
	    }
	  else
	    p = set_indirect (v, pi, key, &found_key);
	}
      else
	{
	  p = get_indirect (v, pi, key);
	  found_key = p != 0;
	  if (found_key && op == UNSET)
	    {
	      if (old_value && value_bytes)
		clib_memcpy_fast (old_value, &p->direct.value, value_bytes);

	      unset_indirect (v, i, &p->direct);

	      /* Nullify p (since it's just been deleted).
	         Otherwise we might be tempted to play with it. */
	      p = 0;
	    }
	}
    }

  if (op == SET && p != 0 && value_bytes)
    {
      /* Save away old value for caller. */
      if (old_value && found_key)
	clib_memcpy_fast (old_value, &p->direct.value, value_bytes);
      clib_memcpy_fast (&p->direct.value, new_value, value_bytes);
    }

  if (op == SET)
    h->elts += !found_key;
  if (op == UNSET)
    h->elts -= found_key;

  return &p->direct;
}

/* Fetch value of key. */
__clib_export uword *
_hash_get (void *v, uword key)
{
  hash_t *h = hash_header (v);
  hash_pair_t *p;

  /* Don't even search table if its empty. */
  if (!v || h->elts == 0)
    return 0;

  p = lookup (v, key, GET, 0, 0);
  if (!p)
    return 0;
  if (h->log2_pair_size == 0)
    return &p->key;
  else
    return &p->value[0];
}

__clib_export hash_pair_t *
_hash_get_pair (void *v, uword key)
{
  return lookup (v, key, GET, 0, 0);
}

hash_pair_t *
hash_next (void *v, hash_next_t * hn)
{
  hash_t *h = hash_header (v);
  hash_pair_t *p;

  while (1)
    {
      if (hn->i == 0 && hn->j == 0)
	{
	  /* Save flags. */
	  hn->f = h->flags;

	  /* Prevent others from re-sizing hash table. */
	  h->flags |=
	    (HASH_FLAG_NO_AUTO_GROW
	     | HASH_FLAG_NO_AUTO_SHRINK | HASH_FLAG_HASH_NEXT_IN_PROGRESS);
	}
      else if (hn->i >= hash_capacity (v))
	{
	  /* Restore flags. */
	  h->flags = hn->f;
	  clib_memset (hn, 0, sizeof (hn[0]));
	  return 0;
	}

      p = hash_forward (h, v, hn->i);
      if (hash_is_user (v, hn->i))
	{
	  hn->i++;
	  return p;
	}
      else
	{
	  hash_pair_indirect_t *pi = (void *) p;
	  uword n;

	  if (h->log2_pair_size > 0)
	    n = indirect_pair_get_len (pi);
	  else
	    n = vec_len (pi->pairs);

	  if (hn->j >= n)
	    {
	      hn->i++;
	      hn->j = 0;
	    }
	  else
	    return hash_forward (h, pi->pairs, hn->j++);
	}
    }
}

/* Remove key from table. */
__clib_export void *
_hash_unset (void *v, uword key, void *old_value)
{
  hash_t *h;

  if (!v)
    return v;

  (void) lookup (v, key, UNSET, 0, old_value);

  h = hash_header (v);
  if (!(h->flags & HASH_FLAG_NO_AUTO_SHRINK))
    {
      /* Resize when 1/4 full. */
      if (h->elts > 32 && 4 * (h->elts + 1) < vec_len (v))
	v = hash_resize (v, vec_len (v) / 2);
    }

  return v;
}

__clib_export void *
_hash_create (uword elts, hash_t * h_user)
{
  hash_t *h;
  uword log2_pair_size;
  void *v;

  /* Size of hash is power of 2 >= ELTS and larger than
     number of bits in is_user bitmap elements. */
  elts = clib_max (elts, BITS (h->is_user[0]));
  elts = 1ULL << max_log2 (elts);

  log2_pair_size = 1;
  if (h_user)
    log2_pair_size = h_user->log2_pair_size;

  v = _vec_resize ((void *) 0,
		   /* vec len: */ elts,
		   /* data bytes: */
		   (elts << log2_pair_size) * sizeof (hash_pair_t),
		   /* header bytes: */
		   sizeof (h[0]) +
		   (elts / BITS (h->is_user[0])) * sizeof (h->is_user[0]),
		   /* alignment */ sizeof (hash_pair_t));
  h = hash_header (v);

  if (h_user)
    h[0] = h_user[0];

  h->log2_pair_size = log2_pair_size;
  h->elts = 0;

  /* Default flags to never shrinking hash tables.
     Shrinking tables can cause "jackpot" cases. */
  if (!h_user)
    h->flags = HASH_FLAG_NO_AUTO_SHRINK;

  if (!h->format_pair)
    {
      h->format_pair = hash_format_pair_default;
      h->format_pair_arg = 0;
    }

  return v;
}

__clib_export void *
_hash_free (void *v)
{
  hash_t *h = hash_header (v);
  hash_pair_union_t *p;
  uword i;

  if (!v)
    return v;

  /* We zero all freed memory in case user would be tempted to use it. */
  for (i = 0; i < hash_capacity (v); i++)
    {
      if (hash_is_user (v, i))
	continue;
      p = get_pair (v, i);
      if (h->log2_pair_size == 0)
	vec_free (p->indirect.pairs);
      else if (p->indirect.pairs)
	clib_mem_free (p->indirect.pairs);
    }

  vec_free_header (h);

  return 0;
}

static void *
hash_resize_internal (void *old, uword new_size, uword free_old)
{
  void *new;
  hash_pair_t *p;

  new = 0;
  if (new_size > 0)
    {
      hash_t *h = old ? hash_header (old) : 0;
      new = _hash_create (new_size, h);
      /* *INDENT-OFF* */
      hash_foreach_pair (p, old, {
	new = _hash_set3 (new, p->key, &p->value[0], 0);
      });
      /* *INDENT-ON* */
    }

  if (free_old)
    hash_free (old);
  return new;
}

void *
hash_resize (void *old, uword new_size)
{
  return hash_resize_internal (old, new_size, 1);
}

__clib_export void *
hash_dup (void *old)
{
  return hash_resize_internal (old, vec_len (old), 0);
}

__clib_export void *
_hash_set3 (void *v, uword key, void *value, void *old_value)
{
  hash_t *h;

  if (!v)
    v = hash_create (0, sizeof (uword));

  h = hash_header (v);
  (void) lookup (v, key, SET, value, old_value);

  if (!(h->flags & HASH_FLAG_NO_AUTO_GROW))
    {
      /* Resize when 3/4 full. */
      if (4 * (h->elts + 1) > 3 * vec_len (v))
	v = hash_resize (v, 2 * vec_len (v));
    }

  return v;
}

__clib_export uword
vec_key_sum (hash_t * h, uword key)
{
  void *v = uword_to_pointer (key, void *);
  return hash_memory (v, vec_len (v) * h->user, 0);
}

__clib_export uword
vec_key_equal (hash_t * h, uword key1, uword key2)
{
  void *v1 = uword_to_pointer (key1, void *);
  void *v2 = uword_to_pointer (key2, void *);
  uword l1 = vec_len (v1);
  uword l2 = vec_len (v2);
  return l1 == l2 && 0 == memcmp (v1, v2, l1 * h->user);
}

__clib_export u8 *
vec_key_format_pair (u8 * s, va_list * args)
{
  void *CLIB_UNUSED (user_arg) = va_arg (*args, void *);
  void *v = va_arg (*args, void *);
  hash_pair_t *p = va_arg (*args, hash_pair_t *);
  hash_t *h = hash_header (v);
  void *u = uword_to_pointer (p->key, void *);
  int i;

  switch (h->user)
    {
    case 1:
      s = format (s, "%v", u);
      break;

    case 2:
      {
	u16 *w = u;
	for (i = 0; i < vec_len (w); i++)
	  s = format (s, "0x%x, ", w[i]);
	break;
      }

    case 4:
      {
	u32 *w = u;
	for (i = 0; i < vec_len (w); i++)
	  s = format (s, "0x%x, ", w[i]);
	break;
      }

    case 8:
      {
	u64 *w = u;
	for (i = 0; i < vec_len (w); i++)
	  s = format (s, "0x%Lx, ", w[i]);
	break;
      }

    default:
      s = format (s, "0x%U", format_hex_bytes, u, vec_len (u) * h->user);
      break;
    }

  if (hash_value_bytes (h) > 0)
    s = format (s, " -> 0x%wx", p->value[0]);

  return s;
}

__clib_export uword
mem_key_sum (hash_t * h, uword key)
{
  uword *v = uword_to_pointer (key, void *);
  return hash_memory (v, h->user, 0);
}

__clib_export uword
mem_key_equal (hash_t * h, uword key1, uword key2)
{
  void *v1 = uword_to_pointer (key1, void *);
  void *v2 = uword_to_pointer (key2, void *);
  return v1 && v2 && 0 == memcmp (v1, v2, h->user);
}

uword
string_key_sum (hash_t * h, uword key)
{
  char *v = uword_to_pointer (key, char *);
  return hash_memory (v, strlen (v), 0);
}

uword
string_key_equal (hash_t * h, uword key1, uword key2)
{
  void *v1 = uword_to_pointer (key1, void *);
  void *v2 = uword_to_pointer (key2, void *);
  return v1 && v2 && 0 == strcmp (v1, v2);
}

u8 *
string_key_format_pair (u8 * s, va_list * args)
{
  void *CLIB_UNUSED (user_arg) = va_arg (*args, void *);
  void *v = va_arg (*args, void *);
  hash_pair_t *p = va_arg (*args, hash_pair_t *);
  hash_t *h = hash_header (v);
  void *u = uword_to_pointer (p->key, void *);

  s = format (s, "%s", u);

  if (hash_value_bytes (h) > 0)
    s =
      format (s, " -> 0x%8U", format_hex_bytes, &p->value[0],
	      hash_value_bytes (h));

  return s;
}

static u8 *
hash_format_pair_default (u8 * s, va_list * args)
{
  void *CLIB_UNUSED (user_arg) = va_arg (*args, void *);
  void *v = va_arg (*args, void *);
  hash_pair_t *p = va_arg (*args, hash_pair_t *);
  hash_t *h = hash_header (v);

  s = format (s, "0x%08x", p->key);
  if (hash_value_bytes (h) > 0)
    s =
      format (s, " -> 0x%8U", format_hex_bytes, &p->value[0],
	      hash_value_bytes (h));
  return s;
}

__clib_export uword
hash_bytes (void *v)
{
  uword i, bytes;
  hash_t *h = hash_header (v);

  if (!v)
    return 0;

  bytes = vec_capacity (v, hash_header_bytes (v));

  for (i = 0; i < hash_capacity (v); i++)
    {
      if (!hash_is_user (v, i))
	{
	  hash_pair_union_t *p = get_pair (v, i);
	  if (h->log2_pair_size > 0)
	    bytes += 1 << indirect_pair_get_log2_bytes (&p->indirect);
	  else
	    bytes += vec_capacity (p->indirect.pairs, 0);
	}
    }
  return bytes;
}

u8 *
format_hash (u8 * s, va_list * va)
{
  void *v = va_arg (*va, void *);
  int verbose = va_arg (*va, int);
  hash_pair_t *p;
  hash_t *h = hash_header (v);
  uword i;

  s = format (s, "hash %p, %wd elts, capacity %wd, %wd bytes used,\n",
	      v, hash_elts (v), hash_capacity (v), hash_bytes (v));

  {
    uword *occupancy = 0;

    /* Count number of buckets with each occupancy. */
    for (i = 0; i < hash_capacity (v); i++)
      {
	uword j;

	if (hash_is_user (v, i))
	  {
	    j = 1;
	  }
	else
	  {
	    hash_pair_union_t *p = get_pair (v, i);
	    if (h->log2_pair_size > 0)
	      j = indirect_pair_get_len (&p->indirect);
	    else
	      j = vec_len (p->indirect.pairs);
	  }

	vec_validate (occupancy, j);
	occupancy[j]++;
      }

    s = format (s, "  profile ");
    for (i = 0; i < vec_len (occupancy); i++)
      s = format (s, "%wd%c", occupancy[i],
		  i + 1 == vec_len (occupancy) ? '\n' : ' ');

    s = format (s, "  lookup # of compares: ");
    for (i = 1; i < vec_len (occupancy); i++)
      s = format (s, "%wd: .%03d%c", i,
		  (1000 * i * occupancy[i]) / hash_elts (v),
		  i + 1 == vec_len (occupancy) ? '\n' : ' ');

    vec_free (occupancy);
  }

  if (verbose)
    {
      /* *INDENT-OFF* */
      hash_foreach_pair (p, v, {
	s = format (s, "  %U\n", h->format_pair, h->format_pair_arg, v, p);
      });
      /* *INDENT-ON* */
    }

  return s;
}

static uword
unformat_hash_string_internal (unformat_input_t * input,
			       va_list * va, int is_vec)
{
  uword *hash = va_arg (*va, uword *);
  int *result = va_arg (*va, int *);
  u8 *string = 0;
  uword *p;

  if (!unformat (input, is_vec ? "%v%_" : "%s%_", &string))
    return 0;

  p = hash_get_mem (hash, string);
  if (p)
    *result = *p;

  vec_free (string);
  return p ? 1 : 0;
}

__clib_export uword
unformat_hash_vec_string (unformat_input_t * input, va_list * va)
{
  return unformat_hash_string_internal (input, va, /* is_vec */ 1);
}

__clib_export uword
unformat_hash_string (unformat_input_t * input, va_list * va)
{
  return unformat_hash_string_internal (input, va, /* is_vec */ 0);
}

clib_error_t *
hash_validate (void *v)
{
  hash_t *h = hash_header (v);
  uword i, j;
  uword *keys = 0;
  clib_error_t *error = 0;

#define CHECK(x) if ((error = ERROR_ASSERT (x))) goto done;

  for (i = 0; i < hash_capacity (v); i++)
    {
      hash_pair_union_t *pu = get_pair (v, i);

      if (hash_is_user (v, i))
	{
	  CHECK (pu->direct.key != 0);
	  vec_add1 (keys, pu->direct.key);
	}
      else
	{
	  hash_pair_t *p;
	  hash_pair_indirect_t *pi = &pu->indirect;
	  uword n;

	  n = h->log2_pair_size > 0
	    ? indirect_pair_get_len (pi) : vec_len (pi->pairs);

	  for (p = pi->pairs; n-- > 0; p = hash_forward1 (h, p))
	    {
	      /* Assert key uniqueness. */
	      for (j = 0; j < vec_len (keys); j++)
		CHECK (keys[j] != p->key);
	      vec_add1 (keys, p->key);
	    }
	}
    }

  CHECK (vec_len (keys) == h->elts);

  vec_free (keys);
done:
  return error;
}

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