src/vnet/ip/reass/ip4_sv_reass.c

   1 /*
   2  * Copyright (c) 2017 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 /**
  17  * @file
  18  * @brief IPv4 Shallow Virtual Reassembly.
  19  *
  20  * This file contains the source code for IPv4 Shallow Virtual reassembly.
  21  */
  22
  23 #include <vppinfra/vec.h>
  24 #include <vnet/vnet.h>
  25 #include <vnet/ip/ip.h>
  26 #include <vnet/ip/ip4_to_ip6.h>
  27 #include <vppinfra/fifo.h>
  28 #include <vppinfra/bihash_16_8.h>
  29 #include <vnet/ip/reass/ip4_sv_reass.h>
  30
  31 #define MSEC_PER_SEC 1000
  32 #define IP4_SV_REASS_TIMEOUT_DEFAULT_MS 100
  33 #define IP4_SV_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000      // 10 seconds default
  34 #define IP4_SV_REASS_MAX_REASSEMBLIES_DEFAULT 1024
  35 #define IP4_SV_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT 3
  36 #define IP4_SV_REASS_HT_LOAD_FACTOR (0.75)
  37
  38 typedef enum
  39 {
  40   IP4_SV_REASS_RC_OK,
  41   IP4_SV_REASS_RC_TOO_MANY_FRAGMENTS,
  42   IP4_SV_REASS_RC_UNSUPP_IP_PROTO,
  43 } ip4_sv_reass_rc_t;
  44
  45 typedef struct
  46 {
  47   union
  48   {
  49     struct
  50     {
  51       u32 xx_id;
  52       ip4_address_t src;
  53       ip4_address_t dst;
  54       u16 frag_id;
  55       u8 proto;
  56       u8 unused;
  57     };
  58     u64 as_u64[2];
  59   };
  60 } ip4_sv_reass_key_t;
  61
  62 typedef union
  63 {
  64   struct
  65   {
  66     u32 reass_index;
  67     u32 thread_index;
  68   };
  69   u64 as_u64;
  70 } ip4_sv_reass_val_t;
  71
  72 typedef union
  73 {
  74   struct
  75   {
  76     ip4_sv_reass_key_t k;
  77     ip4_sv_reass_val_t v;
  78   };
  79   clib_bihash_kv_16_8_t kv;
  80 } ip4_sv_reass_kv_t;
  81
  82 typedef struct
  83 {
  84   // hash table key
  85   ip4_sv_reass_key_t key;
  86   // time when last packet was received
  87   f64 last_heard;
  88   // internal id of this reassembly
  89   u64 id;
  90   // trace operation counter
  91   u32 trace_op_counter;
  92   // minimum fragment length for this reassembly - used to estimate MTU
  93   u16 min_fragment_length;
  94   // buffer indexes of buffers in this reassembly in chronological order -
  95   // including overlaps and duplicate fragments
  96   u32 *cached_buffers;
  97   // set to true when this reassembly is completed
  98   bool is_complete;
  99   // ip protocol
 100   u8 ip_proto;
 101   // l4 src port
 102   u16 l4_src_port;
 103   // l4 dst port
 104   u16 l4_dst_port;
 105   u32 next_index;
 106   // lru indexes
 107   u32 lru_prev;
 108   u32 lru_next;
 109 } ip4_sv_reass_t;
 110
 111 typedef struct
 112 {
 113   ip4_sv_reass_t *pool;
 114   u32 reass_n;
 115   u32 id_counter;
 116   clib_spinlock_t lock;
 117   // lru indexes
 118   u32 lru_first;
 119   u32 lru_last;
 120
 121 } ip4_sv_reass_per_thread_t;
 122
 123 typedef struct
 124 {
 125   // IPv4 config
 126   u32 timeout_ms;
 127   f64 timeout;
 128   u32 expire_walk_interval_ms;
 129   // maximum number of fragments in one reassembly
 130   u32 max_reass_len;
 131   // maximum number of reassemblies
 132   u32 max_reass_n;
 133
 134   // IPv4 runtime
 135   clib_bihash_16_8_t hash;
 136   // per-thread data
 137   ip4_sv_reass_per_thread_t *per_thread_data;
 138
 139   // convenience
 140   vlib_main_t *vlib_main;
 141   vnet_main_t *vnet_main;
 142
 143   // node index of ip4-drop node
 144   u32 ip4_drop_idx;
 145   u32 ip4_sv_reass_expire_node_idx;
 146
 147   /** Worker handoff */
 148   u32 fq_index;
 149   u32 fq_feature_index;
 150
 151   // reference count for enabling/disabling feature - per interface
 152   u32 *feature_use_refcount_per_intf;
 153
 154 } ip4_sv_reass_main_t;
 155
 156 extern ip4_sv_reass_main_t ip4_sv_reass_main;
 157
 158 #ifndef CLIB_MARCH_VARIANT
 159 ip4_sv_reass_main_t ip4_sv_reass_main;
 160 #endif /* CLIB_MARCH_VARIANT */
 161
 162 typedef enum
 163 {
 164   IP4_SV_REASSEMBLY_NEXT_INPUT,
 165   IP4_SV_REASSEMBLY_NEXT_DROP,
 166   IP4_SV_REASSEMBLY_NEXT_HANDOFF,
 167   IP4_SV_REASSEMBLY_N_NEXT,
 168 } ip4_sv_reass_next_t;
 169
 170 typedef enum
 171 {
 172   REASS_FRAGMENT_CACHE,
 173   REASS_FINISH,
 174   REASS_FRAGMENT_FORWARD,
 175 } ip4_sv_reass_trace_operation_e;
 176
 177 typedef struct
 178 {
 179   ip4_sv_reass_trace_operation_e action;
 180   u32 reass_id;
 181   u32 op_id;
 182   u8 ip_proto;
 183   u16 l4_src_port;
 184   u16 l4_dst_port;
 185 } ip4_sv_reass_trace_t;
 186
 187 extern vlib_node_registration_t ip4_sv_reass_node;
 188 extern vlib_node_registration_t ip4_sv_reass_node_feature;
 189
 190 static u8 *
 191 format_ip4_sv_reass_trace (u8 * s, va_list * args)
 192 {
 193   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 194   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 195   ip4_sv_reass_trace_t *t = va_arg (*args, ip4_sv_reass_trace_t *);
 196   s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
 197   switch (t->action)
 198     {
 199     case REASS_FRAGMENT_CACHE:
 200       s = format (s, "[cached]");
 201       break;
 202     case REASS_FINISH:
 203       s =
 204         format (s, "[finish, ip proto=%u, src_port=%u, dst_port=%u]",
 205                 t->ip_proto, clib_net_to_host_u16 (t->l4_src_port),
 206                 clib_net_to_host_u16 (t->l4_dst_port));
 207       break;
 208     case REASS_FRAGMENT_FORWARD:
 209       s =
 210         format (s, "[forward, ip proto=%u, src_port=%u, dst_port=%u]",
 211                 t->ip_proto, clib_net_to_host_u16 (t->l4_src_port),
 212                 clib_net_to_host_u16 (t->l4_dst_port));
 213       break;
 214     }
 215   return s;
 216 }
 217
 218 static void
 219 ip4_sv_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 220                         ip4_sv_reass_main_t * rm, ip4_sv_reass_t * reass,
 221                         u32 bi, ip4_sv_reass_trace_operation_e action,
 222                         u32 ip_proto, u16 l4_src_port, u16 l4_dst_port)
 223 {
 224   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 225   ip4_sv_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 226   t->reass_id = reass->id;
 227   t->action = action;
 228   t->op_id = reass->trace_op_counter;
 229   t->ip_proto = ip_proto;
 230   t->l4_src_port = l4_src_port;
 231   t->l4_dst_port = l4_dst_port;
 232   ++reass->trace_op_counter;
 233 #if 0
 234   static u8 *s = NULL;
 235   s = format (s, "%U", format_ip4_sv_reass_trace, NULL, NULL, t);
 236   printf ("%.*s\n", vec_len (s), s);
 237   fflush (stdout);
 238   vec_reset_length (s);
 239 #endif
 240 }
 241
 242
 243 always_inline void
 244 ip4_sv_reass_free (vlib_main_t * vm, ip4_sv_reass_main_t * rm,
 245                    ip4_sv_reass_per_thread_t * rt, ip4_sv_reass_t * reass)
 246 {
 247   clib_bihash_kv_16_8_t kv;
 248   kv.key[0] = reass->key.as_u64[0];
 249   kv.key[1] = reass->key.as_u64[1];
 250   clib_bihash_add_del_16_8 (&rm->hash, &kv, 0);
 251   vlib_buffer_free (vm, reass->cached_buffers,
 252                     vec_len (reass->cached_buffers));
 253   vec_free (reass->cached_buffers);
 254   reass->cached_buffers = NULL;
 255   if (~0 != reass->lru_prev)
 256     {
 257       ip4_sv_reass_t *lru_prev =
 258         pool_elt_at_index (rt->pool, reass->lru_prev);
 259       lru_prev->lru_next = reass->lru_next;
 260     }
 261   if (~0 != reass->lru_next)
 262     {
 263       ip4_sv_reass_t *lru_next =
 264         pool_elt_at_index (rt->pool, reass->lru_next);
 265       lru_next->lru_prev = reass->lru_prev;
 266     }
 267   if (rt->lru_first == reass - rt->pool)
 268     {
 269       rt->lru_first = reass->lru_next;
 270     }
 271   if (rt->lru_last == reass - rt->pool)
 272     {
 273       rt->lru_last = reass->lru_prev;
 274     }
 275   pool_put (rt->pool, reass);
 276   --rt->reass_n;
 277 }
 278
 279 always_inline void
 280 ip4_sv_reass_init (ip4_sv_reass_t * reass)
 281 {
 282   reass->cached_buffers = NULL;
 283   reass->is_complete = false;
 284 }
 285
 286 always_inline ip4_sv_reass_t *
 287 ip4_sv_reass_find_or_create (vlib_main_t * vm, ip4_sv_reass_main_t * rm,
 288                              ip4_sv_reass_per_thread_t * rt,
 289                              ip4_sv_reass_kv_t * kv, u8 * do_handoff)
 290 {
 291   ip4_sv_reass_t *reass = NULL;
 292   f64 now = vlib_time_now (rm->vlib_main);
 293
 294   if (!clib_bihash_search_16_8
 295       (&rm->hash, (clib_bihash_kv_16_8_t *) kv, (clib_bihash_kv_16_8_t *) kv))
 296     {
 297       if (vm->thread_index != kv->v.thread_index)
 298         {
 299           *do_handoff = 1;
 300           return NULL;
 301         }
 302       reass = pool_elt_at_index (rt->pool, kv->v.reass_index);
 303
 304       if (now > reass->last_heard + rm->timeout)
 305         {
 306           ip4_sv_reass_free (vm, rm, rt, reass);
 307           reass = NULL;
 308         }
 309     }
 310
 311   if (reass)
 312     {
 313       reass->last_heard = now;
 314       return reass;
 315     }
 316
 317   if (rt->reass_n >= rm->max_reass_n && rm->max_reass_n)
 318     {
 319       reass = pool_elt_at_index (rt->pool, rt->lru_last);
 320       ip4_sv_reass_free (vm, rm, rt, reass);
 321     }
 322
 323   pool_get (rt->pool, reass);
 324   clib_memset (reass, 0, sizeof (*reass));
 325   reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter;
 326   ++rt->id_counter;
 327   ip4_sv_reass_init (reass);
 328   ++rt->reass_n;
 329   reass->lru_prev = reass->lru_next = ~0;
 330
 331   if (~0 != rt->lru_last)
 332     {
 333       ip4_sv_reass_t *lru_last = pool_elt_at_index (rt->pool, rt->lru_last);
 334       reass->lru_prev = rt->lru_last;
 335       lru_last->lru_next = rt->lru_last = reass - rt->pool;
 336     }
 337
 338   if (~0 == rt->lru_first)
 339     {
 340       rt->lru_first = rt->lru_last = reass - rt->pool;
 341     }
 342
 343   reass->key.as_u64[0] = ((clib_bihash_kv_16_8_t *) kv)->key[0];
 344   reass->key.as_u64[1] = ((clib_bihash_kv_16_8_t *) kv)->key[1];
 345   kv->v.reass_index = (reass - rt->pool);
 346   kv->v.thread_index = vm->thread_index;
 347   reass->last_heard = now;
 348
 349   if (clib_bihash_add_del_16_8 (&rm->hash, (clib_bihash_kv_16_8_t *) kv, 1))
 350     {
 351       ip4_sv_reass_free (vm, rm, rt, reass);
 352       reass = NULL;
 353     }
 354
 355   return reass;
 356 }
 357
 358 always_inline ip4_sv_reass_rc_t
 359 ip4_sv_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 360                      ip4_sv_reass_main_t * rm, ip4_sv_reass_per_thread_t * rt,
 361                      ip4_sv_reass_t * reass, u32 bi0)
 362 {
 363   vlib_buffer_t *fb = vlib_get_buffer (vm, bi0);
 364   ip4_sv_reass_rc_t rc = IP4_SV_REASS_RC_OK;
 365   ip4_header_t *fip = vlib_buffer_get_current (fb);
 366   const u32 fragment_first = ip4_get_fragment_offset_bytes (fip);
 367   if (0 == fragment_first)
 368     {
 369       reass->ip_proto = fip->protocol;
 370       reass->l4_src_port = ip4_get_port (fip, 1);
 371       reass->l4_dst_port = ip4_get_port (fip, 0);
 372       if (!reass->l4_src_port || !reass->l4_dst_port)
 373         return IP4_SV_REASS_RC_UNSUPP_IP_PROTO;
 374       reass->is_complete = true;
 375       vlib_buffer_t *b0 = vlib_get_buffer (vm, bi0);
 376       if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 377         {
 378           ip4_sv_reass_add_trace (vm, node, rm, reass, bi0, REASS_FINISH,
 379                                   reass->ip_proto, reass->l4_src_port,
 380                                   reass->l4_dst_port);
 381         }
 382     }
 383   vec_add1 (reass->cached_buffers, bi0);
 384   if (!reass->is_complete)
 385     {
 386       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 387         {
 388           ip4_sv_reass_add_trace (vm, node, rm, reass, bi0,
 389                                   REASS_FRAGMENT_CACHE, ~0, ~0, ~0);
 390         }
 391       if (vec_len (reass->cached_buffers) > rm->max_reass_len)
 392         {
 393           rc = IP4_SV_REASS_RC_TOO_MANY_FRAGMENTS;
 394         }
 395     }
 396   return rc;
 397 }
 398
 399 always_inline uword
 400 ip4_sv_reass_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 401                      vlib_frame_t * frame, bool is_feature, bool is_custom)
 402 {
 403   u32 *from = vlib_frame_vector_args (frame);
 404   u32 n_left_from, n_left_to_next, *to_next, next_index;
 405   ip4_sv_reass_main_t *rm = &ip4_sv_reass_main;
 406   ip4_sv_reass_per_thread_t *rt = &rm->per_thread_data[vm->thread_index];
 407   clib_spinlock_lock (&rt->lock);
 408
 409   n_left_from = frame->n_vectors;
 410   next_index = node->cached_next_index;
 411
 412   while (n_left_from > 0)
 413     {
 414       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 415
 416       while (n_left_from > 0 && n_left_to_next > 0)
 417         {
 418           u32 bi0;
 419           vlib_buffer_t *b0;
 420           u32 next0;
 421           u32 error0 = IP4_ERROR_NONE;
 422
 423           bi0 = from[0];
 424           b0 = vlib_get_buffer (vm, bi0);
 425
 426           ip4_header_t *ip0 = vlib_buffer_get_current (b0);
 427           if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
 428             {
 429               // this is a regular packet - no fragmentation
 430               vnet_buffer (b0)->ip.reass.ip_proto = ip0->protocol;
 431               vnet_buffer (b0)->ip.reass.l4_src_port = ip4_get_port (ip0, 1);
 432               vnet_buffer (b0)->ip.reass.l4_dst_port = ip4_get_port (ip0, 0);
 433               next0 = IP4_SV_REASSEMBLY_NEXT_INPUT;
 434               goto packet_enqueue;
 435             }
 436           const u32 fragment_first = ip4_get_fragment_offset_bytes (ip0);
 437           const u32 fragment_length =
 438             clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0);
 439           const u32 fragment_last = fragment_first + fragment_length - 1;
 440           if (fragment_first > fragment_last || fragment_first + fragment_length > UINT16_MAX - 20 || (fragment_length < 8 && ip4_get_fragment_more (ip0)))     // 8 is minimum frag length per RFC 791
 441             {
 442               next0 = IP4_SV_REASSEMBLY_NEXT_DROP;
 443               error0 = IP4_ERROR_REASS_MALFORMED_PACKET;
 444               goto packet_enqueue;
 445             }
 446           ip4_sv_reass_kv_t kv;
 447           u8 do_handoff = 0;
 448
 449           kv.k.as_u64[0] =
 450             (u64) vec_elt (ip4_main.fib_index_by_sw_if_index,
 451                            vnet_buffer (b0)->sw_if_index[VLIB_RX]) |
 452             (u64) ip0->src_address.as_u32 << 32;
 453           kv.k.as_u64[1] =
 454             (u64) ip0->dst_address.
 455             as_u32 | (u64) ip0->fragment_id << 32 | (u64) ip0->protocol << 48;
 456
 457           ip4_sv_reass_t *reass =
 458             ip4_sv_reass_find_or_create (vm, rm, rt, &kv, &do_handoff);
 459
 460           if (PREDICT_FALSE (do_handoff))
 461             {
 462               next0 = IP4_SV_REASSEMBLY_NEXT_HANDOFF;
 463               vnet_buffer (b0)->ip.reass.owner_thread_index =
 464                 kv.v.thread_index;
 465               goto packet_enqueue;
 466             }
 467
 468           if (!reass)
 469             {
 470               next0 = IP4_SV_REASSEMBLY_NEXT_DROP;
 471               error0 = IP4_ERROR_REASS_LIMIT_REACHED;
 472               goto packet_enqueue;
 473             }
 474
 475           if (reass->is_complete)
 476             {
 477               vnet_buffer (b0)->ip.reass.ip_proto = reass->ip_proto;
 478               vnet_buffer (b0)->ip.reass.l4_src_port = reass->l4_src_port;
 479               vnet_buffer (b0)->ip.reass.l4_dst_port = reass->l4_dst_port;
 480               next0 = IP4_SV_REASSEMBLY_NEXT_INPUT;
 481               error0 = IP4_ERROR_NONE;
 482               if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 483                 {
 484                   ip4_sv_reass_add_trace (vm, node, rm, reass, bi0,
 485                                           REASS_FRAGMENT_FORWARD,
 486                                           reass->ip_proto,
 487                                           reass->l4_src_port,
 488                                           reass->l4_dst_port);
 489                 }
 490               goto packet_enqueue;
 491             }
 492
 493           ip4_sv_reass_rc_t rc =
 494             ip4_sv_reass_update (vm, node, rm, rt, reass, bi0);
 495           switch (rc)
 496             {
 497             case IP4_SV_REASS_RC_OK:
 498               /* nothing to do here */
 499               break;
 500             case IP4_SV_REASS_RC_TOO_MANY_FRAGMENTS:
 501               vlib_node_increment_counter (vm, node->node_index,
 502                                            IP4_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
 503                                            1);
 504               ip4_sv_reass_free (vm, rm, rt, reass);
 505               goto next_packet;
 506               break;
 507             case IP4_SV_REASS_RC_UNSUPP_IP_PROTO:
 508               vlib_node_increment_counter (vm, node->node_index,
 509                                            IP4_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
 510                                            1);
 511               ip4_sv_reass_free (vm, rm, rt, reass);
 512               goto next_packet;
 513               break;
 514             }
 515           if (reass->is_complete)
 516             {
 517               u32 idx;
 518               vec_foreach_index (idx, reass->cached_buffers)
 519               {
 520                 u32 bi0 = vec_elt (reass->cached_buffers, idx);
 521                 vlib_buffer_t *b0 = vlib_get_buffer (vm, bi0);
 522                 u32 next0 = IP4_SV_REASSEMBLY_NEXT_INPUT;
 523                 if (is_feature)
 524                   {
 525                     vnet_feature_next (&next0, b0);
 526                   }
 527                 if (is_custom)
 528                   {
 529                     next0 = vnet_buffer (b0)->ip.reass.next_index;
 530                   }
 531                 if (0 == n_left_to_next)
 532                   {
 533                     vlib_put_next_frame (vm, node, next_index,
 534                                          n_left_to_next);
 535                     vlib_get_next_frame (vm, node, next_index, to_next,
 536                                          n_left_to_next);
 537                   }
 538                 to_next[0] = bi0;
 539                 to_next += 1;
 540                 n_left_to_next -= 1;
 541                 vnet_buffer (b0)->ip.reass.ip_proto = reass->ip_proto;
 542                 vnet_buffer (b0)->ip.reass.l4_src_port = reass->l4_src_port;
 543                 vnet_buffer (b0)->ip.reass.l4_dst_port = reass->l4_dst_port;
 544                 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 545                   {
 546                     ip4_sv_reass_add_trace (vm, node, rm, reass, bi0,
 547                                             REASS_FRAGMENT_FORWARD,
 548                                             reass->ip_proto,
 549                                             reass->l4_src_port,
 550                                             reass->l4_dst_port);
 551                   }
 552                 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 553                                                  to_next, n_left_to_next, bi0,
 554                                                  next0);
 555               }
 556               _vec_len (reass->cached_buffers) = 0;     // buffers are owned by frame now
 557             }
 558           goto next_packet;
 559
 560         packet_enqueue:
 561           b0->error = node->errors[error0];
 562
 563           to_next[0] = bi0;
 564           to_next += 1;
 565           n_left_to_next -= 1;
 566           if (is_feature && IP4_ERROR_NONE == error0)
 567             {
 568               b0 = vlib_get_buffer (vm, bi0);
 569               vnet_feature_next (&next0, b0);
 570             }
 571           if (is_custom)
 572             {
 573               next0 = vnet_buffer (b0)->ip.reass.next_index;
 574             }
 575           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 576                                            to_next, n_left_to_next,
 577                                            bi0, next0);
 578
 579         next_packet:
 580           from += 1;
 581           n_left_from -= 1;
 582         }
 583
 584       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 585     }
 586
 587   clib_spinlock_unlock (&rt->lock);
 588   return frame->n_vectors;
 589 }
 590
 591 static char *ip4_sv_reass_error_strings[] = {
 592 #define _(sym, string) string,
 593   foreach_ip4_error
 594 #undef _
 595 };
 596
 597 VLIB_NODE_FN (ip4_sv_reass_node) (vlib_main_t * vm,
 598                                   vlib_node_runtime_t * node,
 599                                   vlib_frame_t * frame)
 600 {
 601   return ip4_sv_reass_inline (vm, node, frame, false /* is_feature */ ,
 602                               false /* is_custom */ );
 603 }
 604
 605 /* *INDENT-OFF* */
 606 VLIB_REGISTER_NODE (ip4_sv_reass_node) = {
 607     .name = "ip4-sv-reassembly",
 608     .vector_size = sizeof (u32),
 609     .format_trace = format_ip4_sv_reass_trace,
 610     .n_errors = ARRAY_LEN (ip4_sv_reass_error_strings),
 611     .error_strings = ip4_sv_reass_error_strings,
 612     .n_next_nodes = IP4_SV_REASSEMBLY_N_NEXT,
 613     .next_nodes =
 614         {
 615                 [IP4_SV_REASSEMBLY_NEXT_INPUT] = "ip4-input",
 616                 [IP4_SV_REASSEMBLY_NEXT_DROP] = "ip4-drop",
 617                 [IP4_SV_REASSEMBLY_NEXT_HANDOFF] = "ip4-sv-reassembly-handoff",
 618
 619         },
 620 };
 621 /* *INDENT-ON* */
 622
 623 VLIB_NODE_FN (ip4_sv_reass_node_feature) (vlib_main_t * vm,
 624                                           vlib_node_runtime_t * node,
 625                                           vlib_frame_t * frame)
 626 {
 627   return ip4_sv_reass_inline (vm, node, frame, true /* is_feature */ ,
 628                               false /* is_custom */ );
 629 }
 630
 631 /* *INDENT-OFF* */
 632 VLIB_REGISTER_NODE (ip4_sv_reass_node_feature) = {
 633     .name = "ip4-sv-reassembly-feature",
 634     .vector_size = sizeof (u32),
 635     .format_trace = format_ip4_sv_reass_trace,
 636     .n_errors = ARRAY_LEN (ip4_sv_reass_error_strings),
 637     .error_strings = ip4_sv_reass_error_strings,
 638     .n_next_nodes = IP4_SV_REASSEMBLY_N_NEXT,
 639     .next_nodes =
 640         {
 641                 [IP4_SV_REASSEMBLY_NEXT_INPUT] = "ip4-input",
 642                 [IP4_SV_REASSEMBLY_NEXT_DROP] = "ip4-drop",
 643                 [IP4_SV_REASSEMBLY_NEXT_HANDOFF] = "ip4-sv-reass-feature-hoff",
 644         },
 645 };
 646 /* *INDENT-ON* */
 647
 648 /* *INDENT-OFF* */
 649 VNET_FEATURE_INIT (ip4_sv_reass_feature) = {
 650     .arc_name = "ip4-unicast",
 651     .node_name = "ip4-sv-reassembly-feature",
 652     .runs_before = VNET_FEATURES ("ip4-lookup"),
 653     .runs_after = 0,
 654 };
 655 /* *INDENT-ON* */
 656
 657 /* *INDENT-OFF* */
 658 VLIB_REGISTER_NODE (ip4_sv_reass_custom_node) = {
 659     .name = "ip4-sv-reassembly-custom-next",
 660     .vector_size = sizeof (u32),
 661     .format_trace = format_ip4_sv_reass_trace,
 662     .n_errors = ARRAY_LEN (ip4_sv_reass_error_strings),
 663     .error_strings = ip4_sv_reass_error_strings,
 664     .n_next_nodes = IP4_SV_REASSEMBLY_N_NEXT,
 665     .next_nodes =
 666         {
 667                 [IP4_SV_REASSEMBLY_NEXT_INPUT] = "ip4-input",
 668                 [IP4_SV_REASSEMBLY_NEXT_DROP] = "ip4-drop",
 669                 [IP4_SV_REASSEMBLY_NEXT_HANDOFF] = "ip4-sv-reassembly-handoff",
 670
 671         },
 672 };
 673 /* *INDENT-ON* */
 674
 675 VLIB_NODE_FN (ip4_sv_reass_custom_node) (vlib_main_t * vm,
 676                                          vlib_node_runtime_t * node,
 677                                          vlib_frame_t * frame)
 678 {
 679   return ip4_sv_reass_inline (vm, node, frame, false /* is_feature */ ,
 680                               true /* is_custom */ );
 681 }
 682
 683 #ifndef CLIB_MARCH_VARIANT
 684 always_inline u32
 685 ip4_sv_reass_get_nbuckets ()
 686 {
 687   ip4_sv_reass_main_t *rm = &ip4_sv_reass_main;
 688   u32 nbuckets;
 689   u8 i;
 690
 691   nbuckets = (u32) (rm->max_reass_n / IP4_SV_REASS_HT_LOAD_FACTOR);
 692
 693   for (i = 0; i < 31; i++)
 694     if ((1 << i) >= nbuckets)
 695       break;
 696   nbuckets = 1 << i;
 697
 698   return nbuckets;
 699 }
 700 #endif /* CLIB_MARCH_VARIANT */
 701
 702 typedef enum
 703 {
 704   IP4_EVENT_CONFIG_CHANGED = 1,
 705 } ip4_sv_reass_event_t;
 706
 707 typedef struct
 708 {
 709   int failure;
 710   clib_bihash_16_8_t *new_hash;
 711 } ip4_rehash_cb_ctx;
 712
 713 #ifndef CLIB_MARCH_VARIANT
 714 static int
 715 ip4_rehash_cb (clib_bihash_kv_16_8_t * kv, void *_ctx)
 716 {
 717   ip4_rehash_cb_ctx *ctx = _ctx;
 718   if (clib_bihash_add_del_16_8 (ctx->new_hash, kv, 1))
 719     {
 720       ctx->failure = 1;
 721     }
 722   return (BIHASH_WALK_CONTINUE);
 723 }
 724
 725 static void
 726 ip4_sv_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
 727                          u32 max_reassembly_length,
 728                          u32 expire_walk_interval_ms)
 729 {
 730   ip4_sv_reass_main.timeout_ms = timeout_ms;
 731   ip4_sv_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
 732   ip4_sv_reass_main.max_reass_n = max_reassemblies;
 733   ip4_sv_reass_main.max_reass_len = max_reassembly_length;
 734   ip4_sv_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
 735 }
 736
 737 vnet_api_error_t
 738 ip4_sv_reass_set (u32 timeout_ms, u32 max_reassemblies,
 739                   u32 max_reassembly_length, u32 expire_walk_interval_ms)
 740 {
 741   u32 old_nbuckets = ip4_sv_reass_get_nbuckets ();
 742   ip4_sv_reass_set_params (timeout_ms, max_reassemblies,
 743                            max_reassembly_length, expire_walk_interval_ms);
 744   vlib_process_signal_event (ip4_sv_reass_main.vlib_main,
 745                              ip4_sv_reass_main.ip4_sv_reass_expire_node_idx,
 746                              IP4_EVENT_CONFIG_CHANGED, 0);
 747   u32 new_nbuckets = ip4_sv_reass_get_nbuckets ();
 748   if (ip4_sv_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
 749     {
 750       clib_bihash_16_8_t new_hash;
 751       clib_memset (&new_hash, 0, sizeof (new_hash));
 752       ip4_rehash_cb_ctx ctx;
 753       ctx.failure = 0;
 754       ctx.new_hash = &new_hash;
 755       clib_bihash_init_16_8 (&new_hash, "ip4-dr", new_nbuckets,
 756                              new_nbuckets * 1024);
 757       clib_bihash_foreach_key_value_pair_16_8 (&ip4_sv_reass_main.hash,
 758                                                ip4_rehash_cb, &ctx);
 759       if (ctx.failure)
 760         {
 761           clib_bihash_free_16_8 (&new_hash);
 762           return -1;
 763         }
 764       else
 765         {
 766           clib_bihash_free_16_8 (&ip4_sv_reass_main.hash);
 767           clib_memcpy_fast (&ip4_sv_reass_main.hash, &new_hash,
 768                             sizeof (ip4_sv_reass_main.hash));
 769           clib_bihash_copied (&ip4_sv_reass_main.hash, &new_hash);
 770         }
 771     }
 772   return 0;
 773 }
 774
 775 vnet_api_error_t
 776 ip4_sv_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
 777                   u32 * max_reassembly_length, u32 * expire_walk_interval_ms)
 778 {
 779   *timeout_ms = ip4_sv_reass_main.timeout_ms;
 780   *max_reassemblies = ip4_sv_reass_main.max_reass_n;
 781   *max_reassembly_length = ip4_sv_reass_main.max_reass_len;
 782   *expire_walk_interval_ms = ip4_sv_reass_main.expire_walk_interval_ms;
 783   return 0;
 784 }
 785
 786 static clib_error_t *
 787 ip4_sv_reass_init_function (vlib_main_t * vm)
 788 {
 789   ip4_sv_reass_main_t *rm = &ip4_sv_reass_main;
 790   clib_error_t *error = 0;
 791   u32 nbuckets;
 792   vlib_node_t *node;
 793
 794   rm->vlib_main = vm;
 795   rm->vnet_main = vnet_get_main ();
 796
 797   vec_validate (rm->per_thread_data, vlib_num_workers ());
 798   ip4_sv_reass_per_thread_t *rt;
 799   vec_foreach (rt, rm->per_thread_data)
 800   {
 801     clib_spinlock_init (&rt->lock);
 802     pool_alloc (rt->pool, rm->max_reass_n);
 803     rt->lru_first = rt->lru_last = ~0;
 804   }
 805
 806   node = vlib_get_node_by_name (vm, (u8 *) "ip4-sv-reassembly-expire-walk");
 807   ASSERT (node);
 808   rm->ip4_sv_reass_expire_node_idx = node->index;
 809
 810   ip4_sv_reass_set_params (IP4_SV_REASS_TIMEOUT_DEFAULT_MS,
 811                            IP4_SV_REASS_MAX_REASSEMBLIES_DEFAULT,
 812                            IP4_SV_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT,
 813                            IP4_SV_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
 814
 815   nbuckets = ip4_sv_reass_get_nbuckets ();
 816   clib_bihash_init_16_8 (&rm->hash, "ip4-dr", nbuckets, nbuckets * 1024);
 817
 818   node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
 819   ASSERT (node);
 820   rm->ip4_drop_idx = node->index;
 821
 822   rm->fq_index = vlib_frame_queue_main_init (ip4_sv_reass_node.index, 0);
 823   rm->fq_feature_index =
 824     vlib_frame_queue_main_init (ip4_sv_reass_node_feature.index, 0);
 825
 826   rm->feature_use_refcount_per_intf = NULL;
 827
 828   return error;
 829 }
 830
 831 VLIB_INIT_FUNCTION (ip4_sv_reass_init_function);
 832 #endif /* CLIB_MARCH_VARIANT */
 833
 834 static uword
 835 ip4_sv_reass_walk_expired (vlib_main_t * vm,
 836                            vlib_node_runtime_t * node, vlib_frame_t * f)
 837 {
 838   ip4_sv_reass_main_t *rm = &ip4_sv_reass_main;
 839   uword event_type, *event_data = 0;
 840
 841   while (true)
 842     {
 843       vlib_process_wait_for_event_or_clock (vm,
 844                                             (f64)
 845                                             rm->expire_walk_interval_ms /
 846                                             (f64) MSEC_PER_SEC);
 847       event_type = vlib_process_get_events (vm, &event_data);
 848
 849       switch (event_type)
 850         {
 851         case ~0:                /* no events => timeout */
 852           /* nothing to do here */
 853           break;
 854         case IP4_EVENT_CONFIG_CHANGED:
 855           break;
 856         default:
 857           clib_warning ("BUG: event type 0x%wx", event_type);
 858           break;
 859         }
 860       f64 now = vlib_time_now (vm);
 861
 862       ip4_sv_reass_t *reass;
 863       int *pool_indexes_to_free = NULL;
 864
 865       uword thread_index = 0;
 866       int index;
 867       const uword nthreads = vlib_num_workers () + 1;
 868       for (thread_index = 0; thread_index < nthreads; ++thread_index)
 869         {
 870           ip4_sv_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
 871           clib_spinlock_lock (&rt->lock);
 872
 873           vec_reset_length (pool_indexes_to_free);
 874           /* *INDENT-OFF* */
 875           pool_foreach_index (index, rt->pool, ({
 876                                 reass = pool_elt_at_index (rt->pool, index);
 877                                 if (now > reass->last_heard + rm->timeout)
 878                                   {
 879                                     vec_add1 (pool_indexes_to_free, index);
 880                                   }
 881                               }));
 882           /* *INDENT-ON* */
 883           int *i;
 884           /* *INDENT-OFF* */
 885           vec_foreach (i, pool_indexes_to_free)
 886           {
 887             ip4_sv_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
 888             ip4_sv_reass_free (vm, rm, rt, reass);
 889           }
 890           /* *INDENT-ON* */
 891
 892           clib_spinlock_unlock (&rt->lock);
 893         }
 894
 895       vec_free (pool_indexes_to_free);
 896       if (event_data)
 897         {
 898           _vec_len (event_data) = 0;
 899         }
 900     }
 901
 902   return 0;
 903 }
 904
 905 /* *INDENT-OFF* */
 906 VLIB_REGISTER_NODE (ip4_sv_reass_expire_node) = {
 907     .function = ip4_sv_reass_walk_expired,
 908     .type = VLIB_NODE_TYPE_PROCESS,
 909     .name = "ip4-sv-reassembly-expire-walk",
 910     .format_trace = format_ip4_sv_reass_trace,
 911     .n_errors = ARRAY_LEN (ip4_sv_reass_error_strings),
 912     .error_strings = ip4_sv_reass_error_strings,
 913
 914 };
 915 /* *INDENT-ON* */
 916
 917 static u8 *
 918 format_ip4_sv_reass_key (u8 * s, va_list * args)
 919 {
 920   ip4_sv_reass_key_t *key = va_arg (*args, ip4_sv_reass_key_t *);
 921   s =
 922     format (s,
 923             "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
 924             key->xx_id, format_ip4_address, &key->src, format_ip4_address,
 925             &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
 926   return s;
 927 }
 928
 929 static u8 *
 930 format_ip4_sv_reass (u8 * s, va_list * args)
 931 {
 932   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
 933   ip4_sv_reass_t *reass = va_arg (*args, ip4_sv_reass_t *);
 934
 935   s = format (s, "ID: %lu, key: %U trace_op_counter: %u\n",
 936               reass->id, format_ip4_sv_reass_key, &reass->key,
 937               reass->trace_op_counter);
 938
 939   vlib_buffer_t *b;
 940   u32 *bip;
 941   u32 counter = 0;
 942   vec_foreach (bip, reass->cached_buffers)
 943   {
 944     u32 bi = *bip;
 945     do
 946       {
 947         b = vlib_get_buffer (vm, bi);
 948         s = format (s, "  #%03u: bi: %u, ", counter, bi);
 949         ++counter;
 950         bi = b->next_buffer;
 951       }
 952     while (b->flags & VLIB_BUFFER_NEXT_PRESENT);
 953   }
 954   return s;
 955 }
 956
 957 static clib_error_t *
 958 show_ip4_reass (vlib_main_t * vm,
 959                 unformat_input_t * input,
 960                 CLIB_UNUSED (vlib_cli_command_t * lmd))
 961 {
 962   ip4_sv_reass_main_t *rm = &ip4_sv_reass_main;
 963
 964   vlib_cli_output (vm, "---------------------");
 965   vlib_cli_output (vm, "IP4 reassembly status");
 966   vlib_cli_output (vm, "---------------------");
 967   bool details = false;
 968   if (unformat (input, "details"))
 969     {
 970       details = true;
 971     }
 972
 973   u32 sum_reass_n = 0;
 974   ip4_sv_reass_t *reass;
 975   uword thread_index;
 976   const uword nthreads = vlib_num_workers () + 1;
 977   for (thread_index = 0; thread_index < nthreads; ++thread_index)
 978     {
 979       ip4_sv_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
 980       clib_spinlock_lock (&rt->lock);
 981       if (details)
 982         {
 983           /* *INDENT-OFF* */
 984           pool_foreach (reass, rt->pool, {
 985             vlib_cli_output (vm, "%U", format_ip4_sv_reass, vm, reass);
 986           });
 987           /* *INDENT-ON* */
 988         }
 989       sum_reass_n += rt->reass_n;
 990       clib_spinlock_unlock (&rt->lock);
 991     }
 992   vlib_cli_output (vm, "---------------------");
 993   vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
 994                    (long unsigned) sum_reass_n);
 995   vlib_cli_output (vm,
 996                    "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
 997                    (long unsigned) rm->max_reass_n);
 998   return 0;
 999 }
1000
1001 /* *INDENT-OFF* */
1002 VLIB_CLI_COMMAND (show_ip4_sv_reass_cmd, static) = {
1003     .path = "show ip4-sv-reassembly",
1004     .short_help = "show ip4-sv-reassembly [details]",
1005     .function = show_ip4_reass,
1006 };
1007 /* *INDENT-ON* */
1008
1009 #ifndef CLIB_MARCH_VARIANT
1010 vnet_api_error_t
1011 ip4_sv_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1012 {
1013   return vnet_feature_enable_disable ("ip4-unicast",
1014                                       "ip4-sv-reassembly-feature",
1015                                       sw_if_index, enable_disable, 0, 0);
1016 }
1017 #endif /* CLIB_MARCH_VARIANT */
1018
1019
1020 #define foreach_ip4_sv_reass_handoff_error                       \
1021 _(CONGESTION_DROP, "congestion drop")
1022
1023
1024 typedef enum
1025 {
1026 #define _(sym,str) IP4_SV_REASSEMBLY_HANDOFF_ERROR_##sym,
1027   foreach_ip4_sv_reass_handoff_error
1028 #undef _
1029     IP4_SV_REASSEMBLY_HANDOFF_N_ERROR,
1030 } ip4_sv_reass_handoff_error_t;
1031
1032 static char *ip4_sv_reass_handoff_error_strings[] = {
1033 #define _(sym,string) string,
1034   foreach_ip4_sv_reass_handoff_error
1035 #undef _
1036 };
1037
1038 typedef struct
1039 {
1040   u32 next_worker_index;
1041 } ip4_sv_reass_handoff_trace_t;
1042
1043 static u8 *
1044 format_ip4_sv_reass_handoff_trace (u8 * s, va_list * args)
1045 {
1046   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1047   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1048   ip4_sv_reass_handoff_trace_t *t =
1049     va_arg (*args, ip4_sv_reass_handoff_trace_t *);
1050
1051   s =
1052     format (s, "ip4-sv-reassembly-handoff: next-worker %d",
1053             t->next_worker_index);
1054
1055   return s;
1056 }
1057
1058 always_inline uword
1059 ip4_sv_reass_handoff_node_inline (vlib_main_t * vm,
1060                                   vlib_node_runtime_t * node,
1061                                   vlib_frame_t * frame, bool is_feature)
1062 {
1063   ip4_sv_reass_main_t *rm = &ip4_sv_reass_main;
1064
1065   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
1066   u32 n_enq, n_left_from, *from;
1067   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
1068   u32 fq_index;
1069
1070   from = vlib_frame_vector_args (frame);
1071   n_left_from = frame->n_vectors;
1072   vlib_get_buffers (vm, from, bufs, n_left_from);
1073
1074   b = bufs;
1075   ti = thread_indices;
1076
1077   fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index;
1078
1079   while (n_left_from > 0)
1080     {
1081       ti[0] = vnet_buffer (b[0])->ip.reass.owner_thread_index;
1082
1083       if (PREDICT_FALSE
1084           ((node->flags & VLIB_NODE_FLAG_TRACE)
1085            && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
1086         {
1087           ip4_sv_reass_handoff_trace_t *t =
1088             vlib_add_trace (vm, node, b[0], sizeof (*t));
1089           t->next_worker_index = ti[0];
1090         }
1091
1092       n_left_from -= 1;
1093       ti += 1;
1094       b += 1;
1095     }
1096   n_enq =
1097     vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
1098                                    frame->n_vectors, 1);
1099
1100   if (n_enq < frame->n_vectors)
1101     vlib_node_increment_counter (vm, node->node_index,
1102                                  IP4_SV_REASSEMBLY_HANDOFF_ERROR_CONGESTION_DROP,
1103                                  frame->n_vectors - n_enq);
1104   return frame->n_vectors;
1105 }
1106
1107 VLIB_NODE_FN (ip4_sv_reass_handoff_node) (vlib_main_t * vm,
1108                                           vlib_node_runtime_t * node,
1109                                           vlib_frame_t * frame)
1110 {
1111   return ip4_sv_reass_handoff_node_inline (vm, node, frame,
1112                                            false /* is_feature */ );
1113 }
1114
1115
1116 /* *INDENT-OFF* */
1117 VLIB_REGISTER_NODE (ip4_sv_reass_handoff_node) = {
1118   .name = "ip4-sv-reassembly-handoff",
1119   .vector_size = sizeof (u32),
1120   .n_errors = ARRAY_LEN(ip4_sv_reass_handoff_error_strings),
1121   .error_strings = ip4_sv_reass_handoff_error_strings,
1122   .format_trace = format_ip4_sv_reass_handoff_trace,
1123
1124   .n_next_nodes = 1,
1125
1126   .next_nodes = {
1127     [0] = "error-drop",
1128   },
1129 };
1130 /* *INDENT-ON* */
1131
1132
1133 /* *INDENT-OFF* */
1134 VLIB_NODE_FN (ip4_sv_reass_feature_handoff_node) (vlib_main_t * vm,
1135                                                     vlib_node_runtime_t *
1136                                                     node,
1137                                                     vlib_frame_t * frame)
1138 {
1139   return ip4_sv_reass_handoff_node_inline (vm, node, frame,
1140                                              true /* is_feature */ );
1141 }
1142 /* *INDENT-ON* */
1143
1144
1145 /* *INDENT-OFF* */
1146 VLIB_REGISTER_NODE (ip4_sv_reass_feature_handoff_node) = {
1147   .name = "ip4-sv-reass-feature-hoff",
1148   .vector_size = sizeof (u32),
1149   .n_errors = ARRAY_LEN(ip4_sv_reass_handoff_error_strings),
1150   .error_strings = ip4_sv_reass_handoff_error_strings,
1151   .format_trace = format_ip4_sv_reass_handoff_trace,
1152
1153   .n_next_nodes = 1,
1154
1155   .next_nodes = {
1156     [0] = "error-drop",
1157   },
1158 };
1159 /* *INDENT-ON* */
1160
1161 #ifndef CLIB_MARCH_VARIANT
1162 int
1163 ip4_sv_reass_enable_disable_with_refcnt (u32 sw_if_index, int is_enable)
1164 {
1165   ip4_sv_reass_main_t *rm = &ip4_sv_reass_main;
1166   vec_validate (rm->feature_use_refcount_per_intf, sw_if_index);
1167   if (is_enable)
1168     {
1169       if (!rm->feature_use_refcount_per_intf[sw_if_index])
1170         {
1171           ++rm->feature_use_refcount_per_intf[sw_if_index];
1172           return vnet_feature_enable_disable ("ip4-unicast",
1173                                               "ip4-sv-reassembly-feature",
1174                                               sw_if_index, 1, 0, 0);
1175         }
1176       ++rm->feature_use_refcount_per_intf[sw_if_index];
1177     }
1178   else
1179     {
1180       --rm->feature_use_refcount_per_intf[sw_if_index];
1181       if (!rm->feature_use_refcount_per_intf[sw_if_index])
1182         return vnet_feature_enable_disable ("ip4-unicast",
1183                                             "ip4-sv-reassembly-feature",
1184                                             sw_if_index, 0, 0, 0);
1185     }
1186   return 0;
1187 }
1188
1189 uword
1190 ip4_sv_reass_custom_register_next_node (uword node_index)
1191 {
1192   return vlib_node_add_next (vlib_get_main (), ip4_sv_reass_custom_node.index,
1193                              node_index);
1194 }
1195 #endif
1196
1197 /*
1198  * fd.io coding-style-patch-verification: ON
1199  *
1200  * Local Variables:
1201  * eval: (c-set-style "gnu")
1202  * End:
1203  */