summaryrefslogtreecommitdiffstats
path: root/src/vnet/adj/adj_nbr.c
AgeCommit message (Expand)AuthorFilesLines
2021-12-31fib: Refetech the adj after the walk in case the pool realloc'dNeale Ranns1-1/+1
2021-11-19fib: Don't use [midchain] adjacencies to change an interface's feature arcNeale Ranns1-0/+40
2021-09-13ip-neighbor: Handle local MAC address change for incomplete adjacenciesNeale Ranns1-1/+34
2021-06-08fib: make sure adj is valid during walkBenoît Ganne1-0/+3
2021-02-15ip: Path MTUNeale Ranns1-1/+24
2020-09-02fib: fix ADJ_NBR_ITF_OK param erroryedg1-1/+1
2020-09-01fib: detect wrong adj neighbour bugsBenoît Ganne1-0/+23
2020-05-29fib: Safe adj walkNeale Ranns1-8/+15
2020-05-26fib: Use basic hash for adjacency neighbour tableNeale Ranns1-82/+42
2020-05-04fib: midchain adjacency optimisationsNeale Ranns1-2/+9
2020-02-03fib: refresh adj pointer after fib_walk_sync due to possible reallocSteven Luong1-0/+6
2020-01-27ipip: Multi-point interfaceNeale Ranns1-9/+25
2020-01-27fib: Reload the adj after possible realloc (VPP-1822)Neale Ranns1-0/+1
2020-01-22fib: Adjacency realloc during rewrite update walk (VPP-1822)Neale Ranns1-4/+4
2019-12-17ip: Protocol Independent IP NeighborsNeale Ranns1-8/+11
2019-12-17fib: Adjacency walk fix for IPv6Neale Ranns1-1/+1
2019-12-16vppinfra: bihash walk cb typedef and continue/stop controlsNeale Ranns1-3/+6
2019-12-15fib: Adjacency creation notifications for dlegatesNeale Ranns1-1/+4
2019-10-16fib: fix use-after-free for interface adj removalBenoît Ganne1-0/+3
2019-04-08fixing typosJim Thompson1-2/+2
2019-03-28Typos. A bunch of typos I've been collecting.Paul Vinciguerra1-8/+8
2018-12-16IP6-MFIB: replace the radix tree with bihash (VPP-1526)Neale Ranns1-0/+2
2018-11-15GBP: redirect contractsNeale Ranns1-9/+7
2018-10-30ADJ: init MTU to interface defaultNeale Ranns1-0/+2
2018-10-23c11 safe string handling supportDave Barach1-1/+1
2018-08-27Adjacency walks protected by 'walk in progress' flagNeale Ranns1-2/+11
2018-07-20IP directed broadcastNeale Ranns1-0/+5
2018-06-11MTU: Software interface / Per-protocol MTU supportOle Troan1-1/+1
2018-05-25ARP proxy dumpsNeale Ranns1-1/+2
2018-05-17tcp: handle link-local addressesFlorin Coras1-1/+1
2018-04-25Adjacency walk more scalableNeale Ranns1-50/+25
2018-03-30bond: show trace causes a crash if the interface is deletedSteven1-4/+2
2018-02-16Allow providers to override glean behaviourNeale Ranns1-15/+0
2018-02-15Revert "Allow interface types to override glean adjacency behaivour"Ole Trøan1-0/+15
2018-02-15Allow interface types to override glean adjacency behaivourNeale Ranns1-15/+0
2017-10-25L3 proxy FIB source for container networkingAndrew Yourtchenko1-0/+2
2017-04-07MPLS McastNeale Ranns1-2/+0
2017-04-03Adjacency layout change and move to vnet/adjNeale Ranns1-4/+4
2017-03-27Fix output feature processing (VPP-670)AkshayaNadahalli1-7/+6
2017-03-27Fix output feature processing (VPP-670)AkshayaNadahalli1-0/+42
2017-03-17Cache a 'has-features' flag on the adjacency for faster access. Reclaim the n...Neale Ranns1-3/+1
2017-01-27IP Multicast FIB (mfib)Neale Ranns1-1/+1
2016-12-28Reorganize source tree to use single autotools instanceDamjan Marion1-0/+1087
' href='#n828'>828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 
/*
 * Copyright (c) 2017 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * @file
 * @brief IPv4 Reassembly.
 *
 * This file contains the source code for IPv4 reassembly.
 */

#include <vppinfra/vec.h>
#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vppinfra/bihash_16_8.h>
#include <vnet/ip/ip4_reassembly.h>

#define MSEC_PER_SEC 1000
#define IP4_REASS_TIMEOUT_DEFAULT_MS 100
#define IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000	// 10 seconds default
#define IP4_REASS_MAX_REASSEMBLIES_DEFAULT 1024
#define IP4_REASS_HT_LOAD_FACTOR (0.75)

#define IP4_REASS_DEBUG_BUFFERS 0
#if IP4_REASS_DEBUG_BUFFERS
#define IP4_REASS_DEBUG_BUFFER(bi, what)             \
  do                                                 \
    {                                                \
      u32 _bi = bi;                                  \
      printf (#what "buffer %u", _bi);               \
      vlib_buffer_t *_b = vlib_get_buffer (vm, _bi); \
      while (_b->flags & VLIB_BUFFER_NEXT_PRESENT)   \
        {                                            \
          _bi = _b->next_buffer;                     \
          printf ("[%u]", _bi);                      \
          _b = vlib_get_buffer (vm, _bi);            \
        }                                            \
      printf ("\n");                                 \
      fflush (stdout);                               \
    }                                                \
  while (0)
#else
#define IP4_REASS_DEBUG_BUFFER(...)
#endif

static vlib_node_registration_t ip4_reass_node;

typedef struct
{
  union
  {
    struct
    {
      u32 xx_id;
      ip4_address_t src;
      ip4_address_t dst;
      u16 frag_id;
      u8 proto;
      u8 unused;
    };
    u64 as_u64[2];
  };
} ip4_reass_key_t;

always_inline u32
ip4_reass_buffer_get_data_offset_no_check (vlib_buffer_t * b)
{
  vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
}

always_inline u32
ip4_reass_buffer_get_data_offset (vlib_buffer_t * b)
{
  vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  ASSERT (vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first);
  return ip4_reass_buffer_get_data_offset_no_check (b);
}

always_inline u16
ip4_reass_buffer_get_data_len_no_check (vlib_buffer_t * b)
{
  vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
    (vnb->ip.reass.fragment_first + ip4_reass_buffer_get_data_offset (b)) + 1;
}

always_inline u16
ip4_reass_buffer_get_data_len (vlib_buffer_t * b)
{
  vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  ASSERT (vnb->ip.reass.range_last > vnb->ip.reass.fragment_first);
  return ip4_reass_buffer_get_data_len_no_check (b);
}

typedef struct
{
  // hash table key
  ip4_reass_key_t key;
  // time when last packet was received
  f64 last_heard;
  // internal id of this reassembly
  u64 id;
  // buffer index of first buffer in this reassembly context
  u32 first_bi;
  // last octet of packet, ~0 until fragment without more_fragments arrives
  u32 last_packet_octet;
  // length of data collected so far
  u32 data_len;
  // trace operation counter
  u32 trace_op_counter;
  // next index - used by non-feature node
  u8 next_index;
  // minimum fragment length for this reassembly - used to estimate MTU
  u16 min_fragment_length;
} ip4_reass_t;

typedef struct
{
  ip4_reass_t *pool;
  u32 reass_n;
  u32 buffers_n;
  u32 id_counter;
  clib_spinlock_t lock;
} ip4_reass_per_thread_t;

typedef struct
{
  // IPv4 config
  u32 timeout_ms;
  f64 timeout;
  u32 expire_walk_interval_ms;
  u32 max_reass_n;

  // IPv4 runtime
  clib_bihash_16_8_t hash;
  // per-thread data
  ip4_reass_per_thread_t *per_thread_data;

  // convenience
  vlib_main_t *vlib_main;
  vnet_main_t *vnet_main;

  // node index of ip4-drop node
  u32 ip4_drop_idx;
  u32 ip4_reass_expire_node_idx;
} ip4_reass_main_t;

ip4_reass_main_t ip4_reass_main;

typedef enum
{
  IP4_REASSEMBLY_NEXT_INPUT,
  IP4_REASSEMBLY_NEXT_DROP,
  IP4_REASSEMBLY_N_NEXT,
} ip4_reass_next_t;

typedef enum
{
  RANGE_NEW,
  RANGE_SHRINK,
  RANGE_DISCARD,
  RANGE_OVERLAP,
  FINALIZE,
} ip4_reass_trace_operation_e;

typedef struct
{
  u16 range_first;
  u16 range_last;
  u32 range_bi;
  i32 data_offset;
  u32 data_len;
  u32 first_bi;
} ip4_reass_range_trace_t;

typedef struct
{
  ip4_reass_trace_operation_e action;
  u32 reass_id;
  ip4_reass_range_trace_t trace_range;
  u32 size_diff;
  u32 op_id;
  u32 fragment_first;
  u32 fragment_last;
  u32 total_data_len;
} ip4_reass_trace_t;

static void
ip4_reass_trace_details (vlib_main_t * vm, u32 bi,
			 ip4_reass_range_trace_t * trace)
{
  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
  vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  trace->range_first = vnb->ip.reass.range_first;
  trace->range_last = vnb->ip.reass.range_last;
  trace->data_offset = ip4_reass_buffer_get_data_offset_no_check (b);
  trace->data_len = ip4_reass_buffer_get_data_len_no_check (b);
  trace->range_bi = bi;
}

static u8 *
format_ip4_reass_range_trace (u8 * s, va_list * args)
{
  ip4_reass_range_trace_t *trace = va_arg (*args, ip4_reass_range_trace_t *);
  s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
	      trace->range_last, trace->data_offset, trace->data_len,
	      trace->range_bi);
  return s;
}

u8 *
format_ip4_reass_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 *);
  ip4_reass_trace_t *t = va_arg (*args, ip4_reass_trace_t *);
  s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
  u32 indent = format_get_indent (s);
  s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
	      t->trace_range.first_bi, t->total_data_len, t->fragment_first,
	      t->fragment_last);
  switch (t->action)
    {
    case RANGE_SHRINK:
      s = format (s, "\n%Ushrink %U by %u", format_white_space, indent,
		  format_ip4_reass_range_trace, &t->trace_range,
		  t->size_diff);
      break;
    case RANGE_DISCARD:
      s = format (s, "\n%Udiscard %U", format_white_space, indent,
		  format_ip4_reass_range_trace, &t->trace_range);
      break;
    case RANGE_NEW:
      s = format (s, "\n%Unew %U", format_white_space, indent,
		  format_ip4_reass_range_trace, &t->trace_range);
      break;
    case RANGE_OVERLAP:
      s = format (s, "\n%Uoverlapping/ignored %U", format_white_space, indent,
		  format_ip4_reass_range_trace, &t->trace_range);
      break;
    case FINALIZE:
      s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
      break;
    }
  return s;
}

static void
ip4_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
		     ip4_reass_main_t * rm, ip4_reass_t * reass, u32 bi,
		     ip4_reass_trace_operation_e action, u32 size_diff)
{
  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
  vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
    {
      // this buffer's trace is gone
      b->flags &= ~VLIB_BUFFER_IS_TRACED;
      return;
    }
  ip4_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
  t->reass_id = reass->id;
  t->action = action;
  ip4_reass_trace_details (vm, bi, &t->trace_range);
  t->size_diff = size_diff;
  t->op_id = reass->trace_op_counter;
  ++reass->trace_op_counter;
  t->fragment_first = vnb->ip.reass.fragment_first;
  t->fragment_last = vnb->ip.reass.fragment_last;
  t->trace_range.first_bi = reass->first_bi;
  t->total_data_len = reass->data_len;
#if 0
  static u8 *s = NULL;
  s = format (s, "%U", format_ip4_reass_trace, NULL, NULL, t);
  printf ("%.*s\n", vec_len (s), s);
  fflush (stdout);
  vec_reset_length (s);
#endif
}

always_inline void
ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
		ip4_reass_t * reass)
{
  clib_bihash_kv_16_8_t kv;
  kv.key[0] = reass->key.as_u64[0];
  kv.key[1] = reass->key.as_u64[1];
  clib_bihash_add_del_16_8 (&rm->hash, &kv, 0);
  pool_put (rt->pool, reass);
  --rt->reass_n;
}

always_inline void
ip4_reass_on_timeout (vlib_main_t * vm, ip4_reass_main_t * rm,
		      ip4_reass_t * reass, u32 ** vec_drop_timeout)
{
  u32 range_bi = reass->first_bi;
  vlib_buffer_t *range_b;
  vnet_buffer_opaque_t *range_vnb;
  while (~0 != range_bi)
    {
      range_b = vlib_get_buffer (vm, range_bi);
      range_vnb = vnet_buffer (range_b);
      u32 bi = range_bi;
      while (~0 != bi)
	{
	  vec_add1 (*vec_drop_timeout, bi);
	  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
	  if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
	    {
	      bi = b->next_buffer;
	      b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
	    }
	  else
	    {
	      bi = ~0;
	    }
	}
      range_bi = range_vnb->ip.reass.next_range_bi;
    }
}

ip4_reass_t *
ip4_reass_find_or_create (vlib_main_t * vm, ip4_reass_main_t * rm,
			  ip4_reass_per_thread_t * rt,
			  ip4_reass_key_t * k, u32 ** vec_drop_timeout)
{
  ip4_reass_t *reass = NULL;
  f64 now = vlib_time_now (rm->vlib_main);
  clib_bihash_kv_16_8_t kv, value;
  kv.key[0] = k->as_u64[0];
  kv.key[1] = k->as_u64[1];

  if (!clib_bihash_search_16_8 (&rm->hash, &kv, &value))
    {
      reass = pool_elt_at_index (rt->pool, value.value);
      if (now > reass->last_heard + rm->timeout)
	{
	  ip4_reass_on_timeout (vm, rm, reass, vec_drop_timeout);
	  ip4_reass_free (rm, rt, reass);
	  reass = NULL;
	}
    }

  if (reass)
    {
      reass->last_heard = now;
      return reass;
    }

  if (rt->reass_n >= rm->max_reass_n)
    {
      reass = NULL;
      return reass;
    }
  else
    {
      pool_get (rt->pool, reass);
      clib_memset (reass, 0, sizeof (*reass));
      reass->id =
	((u64) os_get_thread_index () * 1000000000) + rt->id_counter;
      ++rt->id_counter;
      reass->first_bi = ~0;
      reass->last_packet_octet = ~0;
      reass->data_len = 0;
      ++rt->reass_n;
    }

  reass->key.as_u64[0] = kv.key[0] = k->as_u64[0];
  reass->key.as_u64[1] = kv.key[1] = k->as_u64[1];
  kv.value = reass - rt->pool;
  reass->last_heard = now;

  if (clib_bihash_add_del_16_8 (&rm->hash, &kv, 1))
    {
      ip4_reass_free (rm, rt, reass);
      reass = NULL;
    }

  return reass;
}

always_inline void
ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
		    ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
		    ip4_reass_t * reass, u32 * bi0, u32 * next0,
		    u32 * error0, u32 ** vec_drop_compress,
		    u32 ** vec_drop_overlap, bool is_feature)
{
  ASSERT (~0 != reass->first_bi);
  vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
  vlib_buffer_t *last_b = NULL;
  u32 sub_chain_bi = reass->first_bi;
  u32 total_length = 0;
  u32 buf_cnt = 0;
  u32 dropped_cnt = 0;
  do
    {
      u32 tmp_bi = sub_chain_bi;
      vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
      ip4_header_t *ip = vlib_buffer_get_current (tmp);
      u32 data_len = ip4_reass_buffer_get_data_len (tmp);
      u32 trim_front =
	ip4_header_bytes (ip) + ip4_reass_buffer_get_data_offset (tmp);
      u32 trim_end =
	vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
      if (tmp_bi == reass->first_bi)
	{
	  /* first buffer - keep ip4 header */
	  ASSERT (0 == ip4_reass_buffer_get_data_offset (tmp));
	  trim_front = 0;
	  trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
	    ip4_header_bytes (ip);
	  ASSERT (vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0);
	}
      u32 keep_data =
	vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
      while (1)
	{
	  ++buf_cnt;
	  if (trim_front)
	    {
	      if (trim_front > tmp->current_length)
		{
		  /* drop whole buffer */
		  vec_add1 (*vec_drop_compress, tmp_bi);
		  ++dropped_cnt;
		  trim_front -= tmp->current_length;
		  ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
		  tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
		  tmp_bi = tmp->next_buffer;
		  tmp = vlib_get_buffer (vm, tmp_bi);
		  continue;
		}
	      else
		{
		  vlib_buffer_advance (tmp, trim_front);
		  trim_front = 0;
		}
	    }
	  if (keep_data)
	    {
	      if (last_b)
		{
		  last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
		  last_b->next_buffer = tmp_bi;
		}
	      last_b = tmp;
	      if (keep_data <= tmp->current_length)
		{
		  tmp->current_length = keep_data;
		  keep_data = 0;
		}
	      else
		{
		  keep_data -= tmp->current_length;
		  ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
		}
	      total_length += tmp->current_length;
	    }
	  else
	    {
	      vec_add1 (*vec_drop_overlap, tmp_bi);
	      ASSERT (reass->first_bi != tmp_bi);
	      ++dropped_cnt;
	    }
	  if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
	    {
	      tmp_bi = tmp->next_buffer;
	      tmp = vlib_get_buffer (vm, tmp->next_buffer);
	    }
	  else
	    {
	      break;
	    }
	}
      sub_chain_bi =
	vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
	reass.next_range_bi;
    }
  while (~0 != sub_chain_bi);

  ASSERT (last_b != NULL);
  last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
  ASSERT (rt->buffers_n >= (buf_cnt - dropped_cnt));
  rt->buffers_n -= buf_cnt - dropped_cnt;
  ASSERT (total_length >= first_b->current_length);
  total_length -= first_b->current_length;
  first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
  first_b->total_length_not_including_first_buffer = total_length;
  ip4_header_t *ip = vlib_buffer_get_current (first_b);
  ip->flags_and_fragment_offset = 0;
  ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
  ip->checksum = ip4_header_checksum (ip);
  vlib_buffer_chain_compress (vm, first_b, vec_drop_compress);
  if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
    {
      ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
#if 0
      // following code does a hexdump of packet fragments to stdout ...
      do
	{
	  u32 bi = reass->first_bi;
	  u8 *s = NULL;
	  while (~0 != bi)
	    {
	      vlib_buffer_t *b = vlib_get_buffer (vm, bi);
	      s = format (s, "%u: %U\n", bi, format_hexdump,
			  vlib_buffer_get_current (b), b->current_length);
	      if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
		{
		  bi = b->next_buffer;
		}
	      else
		{
		  break;
		}
	    }
	  printf ("%.*s\n", vec_len (s), s);
	  fflush (stdout);
	  vec_free (s);
	}
      while (0);
#endif
    }
  *bi0 = reass->first_bi;
  if (is_feature)
    {
      *next0 = IP4_REASSEMBLY_NEXT_INPUT;
    }
  else
    {
      *next0 = reass->next_index;
    }
  vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
  *error0 = IP4_ERROR_NONE;
  ip4_reass_free (rm, rt, reass);
  reass = NULL;
}

always_inline u32
ip4_reass_get_buffer_chain_length (vlib_main_t * vm, vlib_buffer_t * b)
{
  u32 len = 0;
  while (b)
    {
      ++len;
      if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
	{
	  b = vlib_get_buffer (vm, b->next_buffer);
	}
      else
	{
	  break;
	}
    }
  return len;
}

always_inline void
ip4_reass_insert_range_in_chain (vlib_main_t * vm,
				 ip4_reass_main_t * rm,
				 ip4_reass_per_thread_t * rt,
				 ip4_reass_t * reass,
				 u32 prev_range_bi, u32 new_next_bi)
{

  vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
  vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
  if (~0 != prev_range_bi)
    {
      vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
      vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
      new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
      prev_vnb->ip.reass.next_range_bi = new_next_bi;
    }
  else
    {
      if (~0 != reass->first_bi)
	{
	  new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
	}
      reass->first_bi = new_next_bi;
    }
  reass->data_len += ip4_reass_buffer_get_data_len (new_next_b);
  rt->buffers_n += ip4_reass_get_buffer_chain_length (vm, new_next_b);
}

always_inline void
ip4_reass_remove_range_from_chain (vlib_main_t * vm,
				   vlib_node_runtime_t * node,
				   ip4_reass_main_t * rm,
				   u32 ** vec_drop_overlap,
				   ip4_reass_t * reass, u32 prev_range_bi,
				   u32 discard_bi)
{
  vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi);
  vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b);
  if (~0 != prev_range_bi)
    {
      vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
      vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
      ASSERT (prev_vnb->ip.reass.next_range_bi == discard_bi);
      prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi;
    }
  else
    {
      reass->first_bi = discard_vnb->ip.reass.next_range_bi;
    }
  reass->data_len -= ip4_reass_buffer_get_data_len (discard_b);
  while (1)
    {
      vec_add1 (*vec_drop_overlap, discard_bi);
      if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED))
	{
	  ip4_reass_add_trace (vm, node, rm, reass, discard_bi, RANGE_DISCARD,
			       0);
	}
      if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT)
	{
	  discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
	  discard_bi = discard_b->next_buffer;
	  discard_b = vlib_get_buffer (vm, discard_bi);
	}
      else
	{
	  break;
	}
    }
}

always_inline void
ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
		  ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
		  ip4_reass_t * reass, u32 * bi0, u32 * next0,
		  u32 * error0, u32 ** vec_drop_overlap,
		  u32 ** vec_drop_compress, bool is_feature)
{
  int consumed = 0;
  vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
  ip4_header_t *fip = vlib_buffer_get_current (fb);
  ASSERT (fb->current_length >= sizeof (*fip));
  vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
  reass->next_index = fvnb->ip.reass.next_index;	// store next_index before it's overwritten
  u32 fragment_first = fvnb->ip.reass.fragment_first =
    ip4_get_fragment_offset_bytes (fip);
  u32 fragment_length =
    clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
  u32 fragment_last = fvnb->ip.reass.fragment_last =
    fragment_first + fragment_length - 1;
  int more_fragments = ip4_get_fragment_more (fip);
  u32 candidate_range_bi = reass->first_bi;
  u32 prev_range_bi = ~0;
  fvnb->ip.reass.range_first = fragment_first;
  fvnb->ip.reass.range_last = fragment_last;
  fvnb->ip.reass.next_range_bi = ~0;
  if (!more_fragments)
    {
      reass->last_packet_octet = fragment_last;
    }
  if (~0 == reass->first_bi)
    {
      // starting a new reassembly
      ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
				       *bi0);
      if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
	{
	  ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
	}
      *bi0 = ~0;
      reass->min_fragment_length = clib_net_to_host_u16 (fip->length);
      return;
    }
  reass->min_fragment_length = clib_min (clib_net_to_host_u16 (fip->length),
					 fvnb->ip.reass.estimated_mtu);
  while (~0 != candidate_range_bi)
    {
      vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
      vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
      if (fragment_first > candidate_vnb->ip.reass.range_last)
	{
	  // this fragments starts after candidate range
	  prev_range_bi = candidate_range_bi;
	  candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
	  if (candidate_vnb->ip.reass.range_last < fragment_last &&
	      ~0 == candidate_range_bi)
	    {
	      // special case - this fragment falls beyond all known ranges
	      ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
					       prev_range_bi, *bi0);
	      consumed = 1;
	      break;
	    }
	  continue;
	}
      if (fragment_last < candidate_vnb->ip.reass.range_first)
	{
	  // this fragment ends before candidate range without any overlap
	  ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
					   *bi0);
	  consumed = 1;
	}
      else
	{
	  if (fragment_first >= candidate_vnb->ip.reass.range_first &&
	      fragment_last <= candidate_vnb->ip.reass.range_last)
	    {
	      // this fragment is a (sub)part of existing range, ignore it
	      if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
		{
		  ip4_reass_add_trace (vm, node, rm, reass, *bi0,
				       RANGE_OVERLAP, 0);
		}
	      break;
	    }
	  int discard_candidate = 0;
	  if (fragment_first < candidate_vnb->ip.reass.range_first)
	    {
	      u32 overlap =
		fragment_last - candidate_vnb->ip.reass.range_first + 1;
	      if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
		{
		  candidate_vnb->ip.reass.range_first += overlap;
		  ASSERT (reass->data_len >= overlap);
		  reass->data_len -= overlap;
		  if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
		    {
		      ip4_reass_add_trace (vm, node, rm, reass,
					   candidate_range_bi, RANGE_SHRINK,
					   overlap);
		    }
		  ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
						   prev_range_bi, *bi0);
		  consumed = 1;
		}
	      else
		{
		  discard_candidate = 1;
		}
	    }
	  else if (fragment_last > candidate_vnb->ip.reass.range_last)
	    {
	      u32 overlap =
		candidate_vnb->ip.reass.range_last - fragment_first + 1;
	      if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
		{
		  fvnb->ip.reass.range_first += overlap;
		  if (~0 != candidate_vnb->ip.reass.next_range_bi)
		    {
		      prev_range_bi = candidate_range_bi;
		      candidate_range_bi =
			candidate_vnb->ip.reass.next_range_bi;
		      continue;
		    }
		  else
		    {
		      // special case - last range discarded
		      ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
						       candidate_range_bi,
						       *bi0);
		      consumed = 1;
		    }
		}
	      else
		{
		  discard_candidate = 1;
		}
	    }
	  else
	    {
	      discard_candidate = 1;
	    }
	  if (discard_candidate)
	    {
	      u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi;
	      // discard candidate range, probe next range
	      ip4_reass_remove_range_from_chain (vm, node, rm,
						 vec_drop_overlap, reass,
						 prev_range_bi,
						 candidate_range_bi);
	      if (~0 != next_range_bi)
		{
		  candidate_range_bi = next_range_bi;
		  continue;
		}
	      else
		{
		  // special case - last range discarded
		  ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
						   prev_range_bi, *bi0);
		  consumed = 1;
		}
	    }
	}
      break;
    }
  if (consumed)
    {
      if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
	{
	  ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
	}
    }
  if (~0 != reass->last_packet_octet &&
      reass->data_len == reass->last_packet_octet + 1)
    {
      ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
			  vec_drop_compress, vec_drop_overlap, is_feature);
    }
  else
    {
      if (consumed)
	{
	  *bi0 = ~0;
	}
      else
	{
	  *next0 = IP4_REASSEMBLY_NEXT_DROP;
	  *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT;
	}
    }
}

always_inline uword
ip4_reassembly_inline (vlib_main_t * vm,
		       vlib_node_runtime_t * node,
		       vlib_frame_t * frame, bool is_feature)
{
  u32 *from = vlib_frame_vector_args (frame);
  u32 n_left_from, n_left_to_next, *to_next, next_index;
  ip4_reass_main_t *rm = &ip4_reass_main;
  ip4_reass_per_thread_t *rt = &rm->per_thread_data[os_get_thread_index ()];
  clib_spinlock_lock (&rt->lock);

  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;
  static u32 *vec_drop_timeout = NULL;	// indexes of buffers which timed out
  static u32 *vec_drop_overlap = NULL;	// indexes of buffers which were discarded due to overlap
  static u32 *vec_drop_compress = NULL;	// indexes of buffers dicarded due to buffer compression
  while (n_left_from > 0 || vec_len (vec_drop_timeout) > 0 ||
	 vec_len (vec_drop_overlap) > 0 || vec_len (vec_drop_compress) > 0)
    {
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
	{
	  u32 bi = vec_pop (vec_drop_timeout);
	  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
	  b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
	  to_next[0] = bi;
	  to_next += 1;
	  n_left_to_next -= 1;
	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
					   n_left_to_next, bi,
					   IP4_REASSEMBLY_NEXT_DROP);
	  IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout);
	  ASSERT (rt->buffers_n > 0);
	  --rt->buffers_n;
	}

      while (vec_len (vec_drop_overlap) > 0 && n_left_to_next > 0)
	{
	  u32 bi = vec_pop (vec_drop_overlap);
	  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
	  b->error = node->errors[IP4_ERROR_REASS_DUPLICATE_FRAGMENT];
	  to_next[0] = bi;
	  to_next += 1;
	  n_left_to_next -= 1;
	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
					   n_left_to_next, bi,
					   IP4_REASSEMBLY_NEXT_DROP);
	  IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_duplicate_fragment);
	  ASSERT (rt->buffers_n > 0);
	  --rt->buffers_n;
	}

      while (vec_len (vec_drop_compress) > 0 && n_left_to_next > 0)
	{
	  u32 bi = vec_pop (vec_drop_compress);
	  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
	  b->error = node->errors[IP4_ERROR_NONE];
	  to_next[0] = bi;
	  to_next += 1;
	  n_left_to_next -= 1;
	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
					   n_left_to_next, bi,
					   IP4_REASSEMBLY_NEXT_DROP);
	  IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_compress);
	  ASSERT (rt->buffers_n > 0);
	  --rt->buffers_n;
	}

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  u32 next0;
	  u32 error0 = IP4_ERROR_NONE;

	  bi0 = from[0];
	  b0 = vlib_get_buffer (vm, bi0);

	  ip4_header_t *ip0 = vlib_buffer_get_current (b0);
	  if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
	    {
	      // this is a whole packet - no fragmentation
	      if (is_feature)
		{
		  next0 = IP4_REASSEMBLY_NEXT_INPUT;
		}
	      else
		{
		  next0 = vnet_buffer (b0)->ip.reass.next_index;
		}
	    }
	  else
	    {
	      ip4_reass_key_t k;
	      k.as_u64[0] =
		(u64) vnet_buffer (b0)->sw_if_index[VLIB_RX] << 32 | (u64)
		ip0->src_address.as_u32;
	      k.as_u64[1] =
		(u64) ip0->dst_address.
		as_u32 << 32 | (u64) ip0->fragment_id << 16 | (u64) ip0->
		protocol << 8;

	      ip4_reass_t *reass =
		ip4_reass_find_or_create (vm, rm, rt, &k, &vec_drop_timeout);

	      if (reass)
		{
		  ip4_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
				    &error0, &vec_drop_overlap,
				    &vec_drop_compress, is_feature);
		}
	      else
		{
		  next0 = IP4_REASSEMBLY_NEXT_DROP;
		  error0 = IP4_ERROR_REASS_LIMIT_REACHED;
		}

	      b0->error = node->errors[error0];
	    }

	  if (bi0 != ~0)
	    {
	      to_next[0] = bi0;
	      to_next += 1;
	      n_left_to_next -= 1;
	      if (is_feature && IP4_ERROR_NONE == error0)
		{
		  b0 = vlib_get_buffer (vm, bi0);
		  vnet_feature_next (&next0, b0);
		}
	      vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
					       n_left_to_next, bi0, next0);
	      IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next);
	    }

	  from += 1;
	  n_left_from -= 1;
	}

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

  clib_spinlock_unlock (&rt->lock);
  return frame->n_vectors;
}

static char *ip4_reassembly_error_strings[] = {
#define _(sym, string) string,
  foreach_ip4_error
#undef _
};

static uword
ip4_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
		vlib_frame_t * frame)
{
  return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ );
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ip4_reass_node, static) = {
    .function = ip4_reassembly,
    .name = "ip4-reassembly",
    .vector_size = sizeof (u32),
    .format_trace = format_ip4_reass_trace,
    .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
    .error_strings = ip4_reassembly_error_strings,
    .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
    .next_nodes =
        {
                [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
                [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
        },
};
/* *INDENT-ON* */

VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node, ip4_reassembly);

static uword
ip4_reassembly_feature (vlib_main_t * vm,
			vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ );
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ip4_reass_node_feature, static) = {
    .function = ip4_reassembly_feature,
    .name = "ip4-reassembly-feature",
    .vector_size = sizeof (u32),
    .format_trace = format_ip4_reass_trace,
    .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
    .error_strings = ip4_reassembly_error_strings,
    .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
    .next_nodes =
        {
                [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
                [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
        },
};
/* *INDENT-ON* */

VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node_feature, ip4_reassembly_feature);

/* *INDENT-OFF* */
VNET_FEATURE_INIT (ip4_reassembly_feature, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "ip4-reassembly-feature",
    .runs_before = VNET_FEATURES ("ip4-lookup"),
    .runs_after = 0,
};
/* *INDENT-ON* */

always_inline u32
ip4_reass_get_nbuckets ()
{
  ip4_reass_main_t *rm = &ip4_reass_main;
  u32 nbuckets;
  u8 i;

  nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR);

  for (i = 0; i < 31; i++)
    if ((1 << i) >= nbuckets)
      break;
  nbuckets = 1 << i;

  return nbuckets;
}

typedef enum
{
  IP4_EVENT_CONFIG_CHANGED = 1,
} ip4_reass_event_t;

typedef struct
{
  int failure;
  clib_bihash_16_8_t *new_hash;
} ip4_rehash_cb_ctx;

static void
ip4_rehash_cb (clib_bihash_kv_16_8_t * kv, void *_ctx)
{
  ip4_rehash_cb_ctx *ctx = _ctx;
  if (clib_bihash_add_del_16_8 (ctx->new_hash, kv, 1))
    {
      ctx->failure = 1;
    }
}

static void
ip4_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
		      u32 expire_walk_interval_ms)
{
  ip4_reass_main.timeout_ms = timeout_ms;
  ip4_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
  ip4_reass_main.max_reass_n = max_reassemblies;
  ip4_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
}

vnet_api_error_t
ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
	       u32 expire_walk_interval_ms)
{
  u32 old_nbuckets = ip4_reass_get_nbuckets ();
  ip4_reass_set_params (timeout_ms, max_reassemblies,
			expire_walk_interval_ms);
  vlib_process_signal_event (ip4_reass_main.vlib_main,
			     ip4_reass_main.ip4_reass_expire_node_idx,
			     IP4_EVENT_CONFIG_CHANGED, 0);
  u32 new_nbuckets = ip4_reass_get_nbuckets ();
  if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
    {
      clib_bihash_16_8_t new_hash;
      clib_memset (&new_hash, 0, sizeof (new_hash));
      ip4_rehash_cb_ctx ctx;
      ctx.failure = 0;
      ctx.new_hash = &new_hash;
      clib_bihash_init_16_8 (&new_hash, "ip4-reass", new_nbuckets,
			     new_nbuckets * 1024);
      clib_bihash_foreach_key_value_pair_16_8 (&ip4_reass_main.hash,
					       ip4_rehash_cb, &ctx);
      if (ctx.failure)
	{
	  clib_bihash_free_16_8 (&new_hash);
	  return -1;
	}
      else
	{
	  clib_bihash_free_16_8 (&ip4_reass_main.hash);
	  clib_memcpy_fast (&ip4_reass_main.hash, &new_hash,
			    sizeof (ip4_reass_main.hash));
	}
    }
  return 0;
}

vnet_api_error_t
ip4_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
	       u32 * expire_walk_interval_ms)
{
  *timeout_ms = ip4_reass_main.timeout_ms;
  *max_reassemblies = ip4_reass_main.max_reass_n;
  *expire_walk_interval_ms = ip4_reass_main.expire_walk_interval_ms;
  return 0;
}

static clib_error_t *
ip4_reass_init_function (vlib_main_t * vm)
{
  ip4_reass_main_t *rm = &ip4_reass_main;
  clib_error_t *error = 0;
  u32 nbuckets;
  vlib_node_t *node;

  rm->vlib_main = vm;
  rm->vnet_main = vnet_get_main ();

  vec_validate (rm->per_thread_data, vlib_num_workers ());
  ip4_reass_per_thread_t *rt;
  vec_foreach (rt, rm->per_thread_data)
  {
    clib_spinlock_init (&rt->lock);
    pool_alloc (rt->pool, rm->max_reass_n);
  }

  node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk");
  ASSERT (node);
  rm->ip4_reass_expire_node_idx = node->index;

  ip4_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS,
			IP4_REASS_MAX_REASSEMBLIES_DEFAULT,
			IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);

  nbuckets = ip4_reass_get_nbuckets ();
  clib_bihash_init_16_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024);

  node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
  ASSERT (node);
  rm->ip4_drop_idx = node->index;

  return error;
}

VLIB_INIT_FUNCTION (ip4_reass_init_function);

static uword
ip4_reass_walk_expired (vlib_main_t * vm,
			vlib_node_runtime_t * node, vlib_frame_t * f)
{
  ip4_reass_main_t *rm = &ip4_reass_main;
  uword event_type, *event_data = 0;

  while (true)
    {
      vlib_process_wait_for_event_or_clock (vm,
					    (f64) rm->expire_walk_interval_ms
					    / (f64) MSEC_PER_SEC);
      event_type = vlib_process_get_events (vm, &event_data);

      switch (event_type)
	{
	case ~0:		/* no events => timeout */
	  /* nothing to do here */
	  break;
	case IP4_EVENT_CONFIG_CHANGED:
	  break;
	default:
	  clib_warning ("BUG: event type 0x%wx", event_type);
	  break;
	}
      f64 now = vlib_time_now (vm);

      ip4_reass_t *reass;
      u32 *vec_drop_timeout = NULL;
      int *pool_indexes_to_free = NULL;

      uword thread_index = 0;
      int index;
      const uword nthreads = vlib_num_workers () + 1;
      for (thread_index = 0; thread_index < nthreads; ++thread_index)
	{
	  ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
	  clib_spinlock_lock (&rt->lock);

	  vec_reset_length (pool_indexes_to_free);
          /* *INDENT-OFF* */
          pool_foreach_index (index, rt->pool, ({
                                reass = pool_elt_at_index (rt->pool, index);
                                if (now > reass->last_heard + rm->timeout)
                                  {
                                    vec_add1 (pool_indexes_to_free, index);
                                  }
                              }));
          /* *INDENT-ON* */
	  int *i;
          /* *INDENT-OFF* */
          vec_foreach (i, pool_indexes_to_free)
          {
            ip4_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
	    u32 before = vec_len (vec_drop_timeout);
	    vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
	    if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
	      {
		if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
					b->trace_index))
		  {
		    /* the trace is gone, don't trace this buffer anymore */
		    b->flags &= ~VLIB_BUFFER_IS_TRACED;
		  }
	      }
            ip4_reass_on_timeout (vm, rm, reass, &vec_drop_timeout);
            u32 after = vec_len (vec_drop_timeout);
            ASSERT (rt->buffers_n >= (after - before));
            rt->buffers_n -= (after - before);
            ip4_reass_free (rm, rt, reass);
          }
          /* *INDENT-ON* */

	  clib_spinlock_unlock (&rt->lock);
	}

      while (vec_len (vec_drop_timeout) > 0)
	{
	  vlib_frame_t *f = vlib_get_frame_to_node (vm, rm->ip4_drop_idx);
	  u32 *to_next = vlib_frame_vector_args (f);
	  u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
	  int trace_frame = 0;
	  while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
	    {
	      u32 bi = vec_pop (vec_drop_timeout);
	      vlib_buffer_t *b = vlib_get_buffer (vm, bi);
	      if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
		{
		  if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
					  b->trace_index))
		    {
		      /* the trace is gone, don't trace this buffer anymore */
		      b->flags &= ~VLIB_BUFFER_IS_TRACED;
		    }
		  else
		    {
		      trace_frame = 1;
		    }
		}
	      b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
	      to_next[0] = bi;
	      ++f->n_vectors;
	      to_next += 1;
	      n_left_to_next -= 1;
	      IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout_walk);
	    }
	  f->frame_flags |= (trace_frame * VLIB_FRAME_TRACE);
	  vlib_put_frame_to_node (vm, rm->ip4_drop_idx, f);
	}

      vec_free (pool_indexes_to_free);
      vec_free (vec_drop_timeout);
      if (event_data)
	{
	  _vec_len (event_data) = 0;
	}
    }

  return 0;
}

static vlib_node_registration_t ip4_reass_expire_node;

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ip4_reass_expire_node, static) = {
    .function = ip4_reass_walk_expired,
    .type = VLIB_NODE_TYPE_PROCESS,
    .name = "ip4-reassembly-expire-walk",
    .format_trace = format_ip4_reass_trace,
    .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
    .error_strings = ip4_reassembly_error_strings,

};
/* *INDENT-ON* */

static u8 *
format_ip4_reass_key (u8 * s, va_list * args)
{
  ip4_reass_key_t *key = va_arg (*args, ip4_reass_key_t *);
  s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
	      key->xx_id, format_ip4_address, &key->src, format_ip4_address,
	      &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
  return s;
}

static u8 *
format_ip4_reass (u8 * s, va_list * args)
{
  vlib_main_t *vm = va_arg (*args, vlib_main_t *);
  ip4_reass_t *reass = va_arg (*args, ip4_reass_t *);

  s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
	      "last_packet_octet: %u, trace_op_counter: %u\n",
	      reass->id, format_ip4_reass_key, &reass->key, reass->first_bi,
	      reass->data_len, reass->last_packet_octet,
	      reass->trace_op_counter);
  u32 bi = reass->first_bi;
  u32 counter = 0;
  while (~0 != bi)
    {
      vlib_buffer_t *b = vlib_get_buffer (vm, bi);
      vnet_buffer_opaque_t *vnb = vnet_buffer (b);
      s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
		  "fragment[%u, %u]\n",
		  counter, vnb->ip.reass.range_first,
		  vnb->ip.reass.range_last, bi,
		  ip4_reass_buffer_get_data_offset_no_check (b),
		  ip4_reass_buffer_get_data_len_no_check (b),
		  vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
      if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
	{
	  bi = b->next_buffer;
	}
      else
	{
	  bi = ~0;
	}
    }
  return s;
}

static clib_error_t *
show_ip4_reass (vlib_main_t * vm, unformat_input_t * input,
		CLIB_UNUSED (vlib_cli_command_t * lmd))
{
  ip4_reass_main_t *rm = &ip4_reass_main;

  vlib_cli_output (vm, "---------------------");
  vlib_cli_output (vm, "IP4 reassembly status");
  vlib_cli_output (vm, "---------------------");
  bool details = false;
  if (unformat (input, "details"))
    {
      details = true;
    }

  u32 sum_reass_n = 0;
  u64 sum_buffers_n = 0;
  ip4_reass_t *reass;
  uword thread_index;
  const uword nthreads = vlib_num_workers () + 1;
  for (thread_index = 0; thread_index < nthreads; ++thread_index)
    {
      ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
      clib_spinlock_lock (&rt->lock);
      if (details)
	{
          /* *INDENT-OFF* */
          pool_foreach (reass, rt->pool, {
            vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass);
          });
          /* *INDENT-ON* */
	}
      sum_reass_n += rt->reass_n;
      sum_buffers_n += rt->buffers_n;
      clib_spinlock_unlock (&rt->lock);
    }
  vlib_cli_output (vm, "---------------------");
  vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
		   (long unsigned) sum_reass_n);
  vlib_cli_output (vm,
		   "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
		   (long unsigned) rm->max_reass_n);
  vlib_cli_output (vm, "Buffers in use: %lu\n",
		   (long unsigned) sum_buffers_n);
  return 0;
}

/* *INDENT-OFF* */
VLIB_CLI_COMMAND (show_ip4_reassembly_cmd, static) = {
    .path = "show ip4-reassembly",
    .short_help = "show ip4-reassembly [details]",
    .function = show_ip4_reass,
};
/* *INDENT-ON* */

vnet_api_error_t
ip4_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
{
  return vnet_feature_enable_disable ("ip4-unicast", "ip4-reassembly-feature",
				      sw_if_index, enable_disable, 0, 0);
}

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