src/vnet/ip/ip4_reassembly.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 Reassembly.
  19  *
  20  * This file contains the source code for IPv4 reassembly.
  21  */
  22
  23 #include <vppinfra/vec.h>
  24 #include <vnet/vnet.h>
  25 #include <vnet/ip/ip.h>
  26 #include <vppinfra/bihash_16_8.h>
  27 #include <vnet/ip/ip4_reassembly.h>
  28
  29 #define MSEC_PER_SEC 1000
  30 #define IP4_REASS_TIMEOUT_DEFAULT_MS 100
  31 #define IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000 // 10 seconds default
  32 #define IP4_REASS_MAX_REASSEMBLIES_DEFAULT 1024
  33 #define IP4_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT 3
  34 #define IP4_REASS_HT_LOAD_FACTOR (0.75)
  35
  36 #define IP4_REASS_DEBUG_BUFFERS 0
  37 #if IP4_REASS_DEBUG_BUFFERS
  38 #define IP4_REASS_DEBUG_BUFFER(bi, what)             \
  39   do                                                 \
  40     {                                                \
  41       u32 _bi = bi;                                  \
  42       printf (#what "buffer %u", _bi);               \
  43       vlib_buffer_t *_b = vlib_get_buffer (vm, _bi); \
  44       while (_b->flags & VLIB_BUFFER_NEXT_PRESENT)   \
  45         {                                            \
  46           _bi = _b->next_buffer;                     \
  47           printf ("[%u]", _bi);                      \
  48           _b = vlib_get_buffer (vm, _bi);            \
  49         }                                            \
  50       printf ("\n");                                 \
  51       fflush (stdout);                               \
  52     }                                                \
  53   while (0)
  54 #else
  55 #define IP4_REASS_DEBUG_BUFFER(...)
  56 #endif
  57
  58 typedef enum
  59 {
  60   IP4_REASS_RC_OK,
  61   IP4_REASS_RC_TOO_MANY_FRAGMENTS,
  62   IP4_REASS_RC_INTERNAL_ERROR,
  63   IP4_REASS_RC_NO_BUF,
  64 } ip4_reass_rc_t;
  65
  66 typedef struct
  67 {
  68   union
  69   {
  70     struct
  71     {
  72       u32 xx_id;
  73       ip4_address_t src;
  74       ip4_address_t dst;
  75       u16 frag_id;
  76       u8 proto;
  77       u8 unused;
  78     };
  79     u64 as_u64[2];
  80   };
  81 } ip4_reass_key_t;
  82
  83 typedef union
  84 {
  85   struct
  86   {
  87     u32 reass_index;
  88     u32 thread_index;
  89   };
  90   u64 as_u64;
  91 } ip4_reass_val_t;
  92
  93 typedef union
  94 {
  95   struct
  96   {
  97     ip4_reass_key_t k;
  98     ip4_reass_val_t v;
  99   };
 100   clib_bihash_kv_16_8_t kv;
 101 } ip4_reass_kv_t;
 102
 103 always_inline u32
 104 ip4_reass_buffer_get_data_offset (vlib_buffer_t * b)
 105 {
 106   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 107   return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
 108 }
 109
 110 always_inline u16
 111 ip4_reass_buffer_get_data_len (vlib_buffer_t * b)
 112 {
 113   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 114   return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
 115     (vnb->ip.reass.fragment_first + ip4_reass_buffer_get_data_offset (b)) + 1;
 116 }
 117
 118 typedef struct
 119 {
 120   // hash table key
 121   ip4_reass_key_t key;
 122   // time when last packet was received
 123   f64 last_heard;
 124   // internal id of this reassembly
 125   u64 id;
 126   // buffer index of first buffer in this reassembly context
 127   u32 first_bi;
 128   // last octet of packet, ~0 until fragment without more_fragments arrives
 129   u32 last_packet_octet;
 130   // length of data collected so far
 131   u32 data_len;
 132   // trace operation counter
 133   u32 trace_op_counter;
 134   // next index - used by non-feature node
 135   u8 next_index;
 136   // minimum fragment length for this reassembly - used to estimate MTU
 137   u16 min_fragment_length;
 138   // number of fragments in this reassembly
 139   u32 fragments_n;
 140 } ip4_reass_t;
 141
 142 typedef struct
 143 {
 144   ip4_reass_t *pool;
 145   u32 reass_n;
 146   u32 id_counter;
 147   clib_spinlock_t lock;
 148 } ip4_reass_per_thread_t;
 149
 150 typedef struct
 151 {
 152   // IPv4 config
 153   u32 timeout_ms;
 154   f64 timeout;
 155   u32 expire_walk_interval_ms;
 156   // maximum number of fragments in one reassembly
 157   u32 max_reass_len;
 158   // maximum number of reassemblies
 159   u32 max_reass_n;
 160
 161   // IPv4 runtime
 162   clib_bihash_16_8_t hash;
 163   // per-thread data
 164   ip4_reass_per_thread_t *per_thread_data;
 165
 166   // convenience
 167   vlib_main_t *vlib_main;
 168   vnet_main_t *vnet_main;
 169
 170   // node index of ip4-drop node
 171   u32 ip4_drop_idx;
 172   u32 ip4_reass_expire_node_idx;
 173
 174   /** Worker handoff */
 175   u32 fq_index;
 176   u32 fq_feature_index;
 177
 178 } ip4_reass_main_t;
 179
 180 extern ip4_reass_main_t ip4_reass_main;
 181
 182 #ifndef CLIB_MARCH_VARIANT
 183 ip4_reass_main_t ip4_reass_main;
 184 #endif /* CLIB_MARCH_VARIANT */
 185
 186 typedef enum
 187 {
 188   IP4_REASSEMBLY_NEXT_INPUT,
 189   IP4_REASSEMBLY_NEXT_DROP,
 190   IP4_REASSEMBLY_NEXT_HANDOFF,
 191   IP4_REASSEMBLY_N_NEXT,
 192 } ip4_reass_next_t;
 193
 194 typedef enum
 195 {
 196   RANGE_NEW,
 197   RANGE_SHRINK,
 198   RANGE_DISCARD,
 199   RANGE_OVERLAP,
 200   FINALIZE,
 201 } ip4_reass_trace_operation_e;
 202
 203 typedef struct
 204 {
 205   u16 range_first;
 206   u16 range_last;
 207   u32 range_bi;
 208   i32 data_offset;
 209   u32 data_len;
 210   u32 first_bi;
 211 } ip4_reass_range_trace_t;
 212
 213 typedef struct
 214 {
 215   ip4_reass_trace_operation_e action;
 216   u32 reass_id;
 217   ip4_reass_range_trace_t trace_range;
 218   u32 size_diff;
 219   u32 op_id;
 220   u32 fragment_first;
 221   u32 fragment_last;
 222   u32 total_data_len;
 223 } ip4_reass_trace_t;
 224
 225 extern vlib_node_registration_t ip4_reass_node;
 226 extern vlib_node_registration_t ip4_reass_node_feature;
 227
 228 static void
 229 ip4_reass_trace_details (vlib_main_t * vm, u32 bi,
 230                          ip4_reass_range_trace_t * trace)
 231 {
 232   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 233   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 234   trace->range_first = vnb->ip.reass.range_first;
 235   trace->range_last = vnb->ip.reass.range_last;
 236   trace->data_offset = ip4_reass_buffer_get_data_offset (b);
 237   trace->data_len = ip4_reass_buffer_get_data_len (b);
 238   trace->range_bi = bi;
 239 }
 240
 241 static u8 *
 242 format_ip4_reass_range_trace (u8 * s, va_list * args)
 243 {
 244   ip4_reass_range_trace_t *trace = va_arg (*args, ip4_reass_range_trace_t *);
 245   s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
 246               trace->range_last, trace->data_offset, trace->data_len,
 247               trace->range_bi);
 248   return s;
 249 }
 250
 251 static u8 *
 252 format_ip4_reass_trace (u8 * s, va_list * args)
 253 {
 254   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 255   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 256   ip4_reass_trace_t *t = va_arg (*args, ip4_reass_trace_t *);
 257   s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
 258   u32 indent = format_get_indent (s);
 259   s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
 260               t->trace_range.first_bi, t->total_data_len, t->fragment_first,
 261               t->fragment_last);
 262   switch (t->action)
 263     {
 264     case RANGE_SHRINK:
 265       s = format (s, "\n%Ushrink %U by %u", format_white_space, indent,
 266                   format_ip4_reass_range_trace, &t->trace_range,
 267                   t->size_diff);
 268       break;
 269     case RANGE_DISCARD:
 270       s = format (s, "\n%Udiscard %U", format_white_space, indent,
 271                   format_ip4_reass_range_trace, &t->trace_range);
 272       break;
 273     case RANGE_NEW:
 274       s = format (s, "\n%Unew %U", format_white_space, indent,
 275                   format_ip4_reass_range_trace, &t->trace_range);
 276       break;
 277     case RANGE_OVERLAP:
 278       s = format (s, "\n%Uoverlapping/ignored %U", format_white_space, indent,
 279                   format_ip4_reass_range_trace, &t->trace_range);
 280       break;
 281     case FINALIZE:
 282       s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
 283       break;
 284     }
 285   return s;
 286 }
 287
 288 static void
 289 ip4_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 290                      ip4_reass_main_t * rm, ip4_reass_t * reass, u32 bi,
 291                      ip4_reass_trace_operation_e action, u32 size_diff)
 292 {
 293   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 294   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 295   if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
 296     {
 297       // this buffer's trace is gone
 298       b->flags &= ~VLIB_BUFFER_IS_TRACED;
 299       return;
 300     }
 301   ip4_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 302   t->reass_id = reass->id;
 303   t->action = action;
 304   ip4_reass_trace_details (vm, bi, &t->trace_range);
 305   t->size_diff = size_diff;
 306   t->op_id = reass->trace_op_counter;
 307   ++reass->trace_op_counter;
 308   t->fragment_first = vnb->ip.reass.fragment_first;
 309   t->fragment_last = vnb->ip.reass.fragment_last;
 310   t->trace_range.first_bi = reass->first_bi;
 311   t->total_data_len = reass->data_len;
 312 #if 0
 313   static u8 *s = NULL;
 314   s = format (s, "%U", format_ip4_reass_trace, NULL, NULL, t);
 315   printf ("%.*s\n", vec_len (s), s);
 316   fflush (stdout);
 317   vec_reset_length (s);
 318 #endif
 319 }
 320
 321
 322 always_inline void
 323 ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 324                 ip4_reass_t * reass)
 325 {
 326   clib_bihash_kv_16_8_t kv;
 327   kv.key[0] = reass->key.as_u64[0];
 328   kv.key[1] = reass->key.as_u64[1];
 329   clib_bihash_add_del_16_8 (&rm->hash, &kv, 0);
 330   pool_put (rt->pool, reass);
 331   --rt->reass_n;
 332 }
 333
 334 always_inline void
 335 ip4_reass_on_timeout (vlib_main_t * vm, ip4_reass_main_t * rm,
 336                       ip4_reass_t * reass)
 337 {
 338   u32 range_bi = reass->first_bi;
 339   vlib_buffer_t *range_b;
 340   vnet_buffer_opaque_t *range_vnb;
 341   u32 *to_free = NULL;
 342   while (~0 != range_bi)
 343     {
 344       range_b = vlib_get_buffer (vm, range_bi);
 345       range_vnb = vnet_buffer (range_b);
 346       u32 bi = range_bi;
 347       while (~0 != bi)
 348         {
 349           vec_add1 (to_free, bi);
 350           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 351           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 352             {
 353               bi = b->next_buffer;
 354               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 355             }
 356           else
 357             {
 358               bi = ~0;
 359             }
 360         }
 361       range_bi = range_vnb->ip.reass.next_range_bi;
 362     }
 363   vlib_buffer_free (vm, to_free, vec_len (to_free));
 364   vec_free (to_free);
 365 }
 366
 367 static ip4_reass_t *
 368 ip4_reass_find_or_create (vlib_main_t * vm, ip4_reass_main_t * rm,
 369                           ip4_reass_per_thread_t * rt, ip4_reass_kv_t * kv,
 370                           u8 * do_handoff)
 371 {
 372   ip4_reass_t *reass = NULL;
 373   f64 now = vlib_time_now (rm->vlib_main);
 374
 375   if (!clib_bihash_search_16_8
 376       (&rm->hash, (clib_bihash_kv_16_8_t *) kv, (clib_bihash_kv_16_8_t *) kv))
 377     {
 378       if (vm->thread_index != kv->v.thread_index)
 379         {
 380           *do_handoff = 1;
 381           return NULL;
 382         }
 383       reass = pool_elt_at_index (rt->pool, kv->v.reass_index);
 384
 385       if (now > reass->last_heard + rm->timeout)
 386         {
 387           ip4_reass_on_timeout (vm, rm, reass);
 388           ip4_reass_free (rm, rt, reass);
 389           reass = NULL;
 390         }
 391     }
 392
 393   if (reass)
 394     {
 395       reass->last_heard = now;
 396       return reass;
 397     }
 398
 399   if (rt->reass_n >= rm->max_reass_n)
 400     {
 401       reass = NULL;
 402       return reass;
 403     }
 404   else
 405     {
 406       pool_get (rt->pool, reass);
 407       clib_memset (reass, 0, sizeof (*reass));
 408       reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter;
 409       ++rt->id_counter;
 410       reass->first_bi = ~0;
 411       reass->last_packet_octet = ~0;
 412       reass->data_len = 0;
 413       ++rt->reass_n;
 414     }
 415
 416   reass->key.as_u64[0] = ((clib_bihash_kv_16_8_t *) kv)->key[0];
 417   reass->key.as_u64[1] = ((clib_bihash_kv_16_8_t *) kv)->key[1];
 418   kv->v.reass_index = (reass - rt->pool);
 419   kv->v.thread_index = vm->thread_index;
 420   reass->last_heard = now;
 421
 422   if (clib_bihash_add_del_16_8 (&rm->hash, (clib_bihash_kv_16_8_t *) kv, 1))
 423     {
 424       ip4_reass_free (rm, rt, reass);
 425       reass = NULL;
 426     }
 427
 428   return reass;
 429 }
 430
 431 always_inline ip4_reass_rc_t
 432 ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 433                     ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 434                     ip4_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 435                     bool is_feature)
 436 {
 437   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 438   vlib_buffer_t *last_b = NULL;
 439   u32 sub_chain_bi = reass->first_bi;
 440   u32 total_length = 0;
 441   u32 buf_cnt = 0;
 442   do
 443     {
 444       u32 tmp_bi = sub_chain_bi;
 445       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 446       ip4_header_t *ip = vlib_buffer_get_current (tmp);
 447       vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
 448       if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 449           !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 450         {
 451           return IP4_REASS_RC_INTERNAL_ERROR;
 452         }
 453
 454       u32 data_len = ip4_reass_buffer_get_data_len (tmp);
 455       u32 trim_front =
 456         ip4_header_bytes (ip) + ip4_reass_buffer_get_data_offset (tmp);
 457       u32 trim_end =
 458         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 459       if (tmp_bi == reass->first_bi)
 460         {
 461           /* first buffer - keep ip4 header */
 462           if (0 != ip4_reass_buffer_get_data_offset (tmp))
 463             {
 464               return IP4_REASS_RC_INTERNAL_ERROR;
 465             }
 466           trim_front = 0;
 467           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 468             ip4_header_bytes (ip);
 469           if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
 470             {
 471               return IP4_REASS_RC_INTERNAL_ERROR;
 472             }
 473         }
 474       u32 keep_data =
 475         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 476       while (1)
 477         {
 478           ++buf_cnt;
 479           if (trim_front)
 480             {
 481               if (trim_front > tmp->current_length)
 482                 {
 483                   /* drop whole buffer */
 484                   u32 to_be_freed_bi = tmp_bi;
 485                   trim_front -= tmp->current_length;
 486                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 487                     {
 488                       return IP4_REASS_RC_INTERNAL_ERROR;
 489                     }
 490                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 491                   tmp_bi = tmp->next_buffer;
 492                   tmp = vlib_get_buffer (vm, tmp_bi);
 493                   vlib_buffer_free_one (vm, to_be_freed_bi);
 494                   continue;
 495                 }
 496               else
 497                 {
 498                   vlib_buffer_advance (tmp, trim_front);
 499                   trim_front = 0;
 500                 }
 501             }
 502           if (keep_data)
 503             {
 504               if (last_b)
 505                 {
 506                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 507                   last_b->next_buffer = tmp_bi;
 508                 }
 509               last_b = tmp;
 510               if (keep_data <= tmp->current_length)
 511                 {
 512                   tmp->current_length = keep_data;
 513                   keep_data = 0;
 514                 }
 515               else
 516                 {
 517                   keep_data -= tmp->current_length;
 518                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 519                     {
 520                       return IP4_REASS_RC_INTERNAL_ERROR;
 521                     }
 522                 }
 523               total_length += tmp->current_length;
 524               if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 525                 {
 526                   tmp_bi = tmp->next_buffer;
 527                   tmp = vlib_get_buffer (vm, tmp->next_buffer);
 528                 }
 529               else
 530                 {
 531                   break;
 532                 }
 533             }
 534           else
 535             {
 536               u32 to_be_freed_bi = tmp_bi;
 537               if (reass->first_bi == tmp_bi)
 538                 {
 539                   return IP4_REASS_RC_INTERNAL_ERROR;
 540                 }
 541               if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 542                 {
 543                   tmp_bi = tmp->next_buffer;
 544                   tmp = vlib_get_buffer (vm, tmp->next_buffer);
 545                   vlib_buffer_free_one (vm, to_be_freed_bi);
 546                 }
 547               else
 548                 {
 549                   vlib_buffer_free_one (vm, to_be_freed_bi);
 550                   break;
 551                 }
 552             }
 553         }
 554       sub_chain_bi =
 555         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 556         reass.next_range_bi;
 557     }
 558   while (~0 != sub_chain_bi);
 559
 560   if (!last_b)
 561     {
 562       return IP4_REASS_RC_INTERNAL_ERROR;
 563     }
 564   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 565   if (total_length < first_b->current_length)
 566     {
 567       return IP4_REASS_RC_INTERNAL_ERROR;
 568     }
 569   total_length -= first_b->current_length;
 570   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 571   first_b->total_length_not_including_first_buffer = total_length;
 572   ip4_header_t *ip = vlib_buffer_get_current (first_b);
 573   ip->flags_and_fragment_offset = 0;
 574   ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
 575   ip->checksum = ip4_header_checksum (ip);
 576   if (!vlib_buffer_chain_linearize (vm, first_b))
 577     {
 578       return IP4_REASS_RC_NO_BUF;
 579     }
 580
 581   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 582     {
 583       ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 584 #if 0
 585       // following code does a hexdump of packet fragments to stdout ...
 586       do
 587         {
 588           u32 bi = reass->first_bi;
 589           u8 *s = NULL;
 590           while (~0 != bi)
 591             {
 592               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 593               s = format (s, "%u: %U\n", bi, format_hexdump,
 594                           vlib_buffer_get_current (b), b->current_length);
 595               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 596                 {
 597                   bi = b->next_buffer;
 598                 }
 599               else
 600                 {
 601                   break;
 602                 }
 603             }
 604           printf ("%.*s\n", vec_len (s), s);
 605           fflush (stdout);
 606           vec_free (s);
 607         }
 608       while (0);
 609 #endif
 610     }
 611   *bi0 = reass->first_bi;
 612   if (is_feature)
 613     {
 614       *next0 = IP4_REASSEMBLY_NEXT_INPUT;
 615     }
 616   else
 617     {
 618       *next0 = reass->next_index;
 619     }
 620   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 621   *error0 = IP4_ERROR_NONE;
 622   ip4_reass_free (rm, rt, reass);
 623   reass = NULL;
 624   return IP4_REASS_RC_OK;
 625 }
 626
 627 always_inline ip4_reass_rc_t
 628 ip4_reass_insert_range_in_chain (vlib_main_t * vm,
 629                                  ip4_reass_main_t * rm,
 630                                  ip4_reass_per_thread_t * rt,
 631                                  ip4_reass_t * reass,
 632                                  u32 prev_range_bi, u32 new_next_bi)
 633 {
 634   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 635   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 636   if (~0 != prev_range_bi)
 637     {
 638       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 639       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 640       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 641       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 642     }
 643   else
 644     {
 645       if (~0 != reass->first_bi)
 646         {
 647           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 648         }
 649       reass->first_bi = new_next_bi;
 650     }
 651   vnet_buffer_opaque_t *vnb = vnet_buffer (new_next_b);
 652   if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 653       !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 654     {
 655       return IP4_REASS_RC_INTERNAL_ERROR;
 656     }
 657   reass->data_len += ip4_reass_buffer_get_data_len (new_next_b);
 658   return IP4_REASS_RC_OK;
 659 }
 660
 661 always_inline ip4_reass_rc_t
 662 ip4_reass_remove_range_from_chain (vlib_main_t * vm,
 663                                    vlib_node_runtime_t * node,
 664                                    ip4_reass_main_t * rm,
 665                                    ip4_reass_t * reass, u32 prev_range_bi,
 666                                    u32 discard_bi)
 667 {
 668   vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi);
 669   vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b);
 670   if (~0 != prev_range_bi)
 671     {
 672       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 673       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 674       if (!(prev_vnb->ip.reass.next_range_bi == discard_bi))
 675         {
 676           return IP4_REASS_RC_INTERNAL_ERROR;
 677         }
 678       prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi;
 679     }
 680   else
 681     {
 682       reass->first_bi = discard_vnb->ip.reass.next_range_bi;
 683     }
 684   vnet_buffer_opaque_t *vnb = vnet_buffer (discard_b);
 685   if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 686       !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 687     {
 688       return IP4_REASS_RC_INTERNAL_ERROR;
 689     }
 690   reass->data_len -= ip4_reass_buffer_get_data_len (discard_b);
 691   while (1)
 692     {
 693       u32 to_be_freed_bi = discard_bi;
 694       if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED))
 695         {
 696           ip4_reass_add_trace (vm, node, rm, reass, discard_bi, RANGE_DISCARD,
 697                                0);
 698         }
 699       if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT)
 700         {
 701           discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 702           discard_bi = discard_b->next_buffer;
 703           discard_b = vlib_get_buffer (vm, discard_bi);
 704           vlib_buffer_free_one (vm, to_be_freed_bi);
 705         }
 706       else
 707         {
 708           vlib_buffer_free_one (vm, to_be_freed_bi);
 709           break;
 710         }
 711     }
 712   return IP4_REASS_RC_OK;
 713 }
 714
 715 always_inline ip4_reass_rc_t
 716 ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 717                   ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 718                   ip4_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 719                   bool is_feature)
 720 {
 721   ip4_reass_rc_t rc = IP4_REASS_RC_OK;
 722   int consumed = 0;
 723   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 724   ip4_header_t *fip = vlib_buffer_get_current (fb);
 725   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 726   reass->next_index = fvnb->ip.reass.next_index;        // store next_index before it's overwritten
 727   const u32 fragment_first = ip4_get_fragment_offset_bytes (fip);
 728   const u32 fragment_length =
 729     clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
 730   const u32 fragment_last = fragment_first + fragment_length - 1;
 731   fvnb->ip.reass.fragment_first = fragment_first;
 732   fvnb->ip.reass.fragment_last = fragment_last;
 733   int more_fragments = ip4_get_fragment_more (fip);
 734   u32 candidate_range_bi = reass->first_bi;
 735   u32 prev_range_bi = ~0;
 736   fvnb->ip.reass.range_first = fragment_first;
 737   fvnb->ip.reass.range_last = fragment_last;
 738   fvnb->ip.reass.next_range_bi = ~0;
 739   if (!more_fragments)
 740     {
 741       reass->last_packet_octet = fragment_last;
 742     }
 743   if (~0 == reass->first_bi)
 744     {
 745       // starting a new reassembly
 746       rc =
 747         ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 748                                          *bi0);
 749       if (IP4_REASS_RC_OK != rc)
 750         {
 751           return rc;
 752         }
 753       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 754         {
 755           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 756         }
 757       *bi0 = ~0;
 758       reass->min_fragment_length = clib_net_to_host_u16 (fip->length);
 759       reass->fragments_n = 1;
 760       return IP4_REASS_RC_OK;
 761     }
 762   reass->min_fragment_length = clib_min (clib_net_to_host_u16 (fip->length),
 763                                          fvnb->ip.reass.estimated_mtu);
 764   while (~0 != candidate_range_bi)
 765     {
 766       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 767       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 768       if (fragment_first > candidate_vnb->ip.reass.range_last)
 769         {
 770           // this fragments starts after candidate range
 771           prev_range_bi = candidate_range_bi;
 772           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 773           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 774               ~0 == candidate_range_bi)
 775             {
 776               // special case - this fragment falls beyond all known ranges
 777               rc =
 778                 ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 779                                                  prev_range_bi, *bi0);
 780               if (IP4_REASS_RC_OK != rc)
 781                 {
 782                   return rc;
 783                 }
 784               consumed = 1;
 785               break;
 786             }
 787           continue;
 788         }
 789       if (fragment_last < candidate_vnb->ip.reass.range_first)
 790         {
 791           // this fragment ends before candidate range without any overlap
 792           rc =
 793             ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 794                                              *bi0);
 795           if (IP4_REASS_RC_OK != rc)
 796             {
 797               return rc;
 798             }
 799           consumed = 1;
 800         }
 801       else
 802         {
 803           if (fragment_first >= candidate_vnb->ip.reass.range_first &&
 804               fragment_last <= candidate_vnb->ip.reass.range_last)
 805             {
 806               // this fragment is a (sub)part of existing range, ignore it
 807               if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 808                 {
 809                   ip4_reass_add_trace (vm, node, rm, reass, *bi0,
 810                                        RANGE_OVERLAP, 0);
 811                 }
 812               break;
 813             }
 814           int discard_candidate = 0;
 815           if (fragment_first < candidate_vnb->ip.reass.range_first)
 816             {
 817               u32 overlap =
 818                 fragment_last - candidate_vnb->ip.reass.range_first + 1;
 819               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 820                 {
 821                   candidate_vnb->ip.reass.range_first += overlap;
 822                   if (reass->data_len < overlap)
 823                     {
 824                       return IP4_REASS_RC_INTERNAL_ERROR;
 825                     }
 826                   reass->data_len -= overlap;
 827                   if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 828                     {
 829                       ip4_reass_add_trace (vm, node, rm, reass,
 830                                            candidate_range_bi, RANGE_SHRINK,
 831                                            overlap);
 832                     }
 833                   rc =
 834                     ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 835                                                      prev_range_bi, *bi0);
 836                   if (IP4_REASS_RC_OK != rc)
 837                     {
 838                       return rc;
 839                     }
 840                   consumed = 1;
 841                 }
 842               else
 843                 {
 844                   discard_candidate = 1;
 845                 }
 846             }
 847           else if (fragment_last > candidate_vnb->ip.reass.range_last)
 848             {
 849               u32 overlap =
 850                 candidate_vnb->ip.reass.range_last - fragment_first + 1;
 851               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 852                 {
 853                   fvnb->ip.reass.range_first += overlap;
 854                   if (~0 != candidate_vnb->ip.reass.next_range_bi)
 855                     {
 856                       prev_range_bi = candidate_range_bi;
 857                       candidate_range_bi =
 858                         candidate_vnb->ip.reass.next_range_bi;
 859                       continue;
 860                     }
 861                   else
 862                     {
 863                       // special case - last range discarded
 864                       rc =
 865                         ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 866                                                          candidate_range_bi,
 867                                                          *bi0);
 868                       if (IP4_REASS_RC_OK != rc)
 869                         {
 870                           return rc;
 871                         }
 872                       consumed = 1;
 873                     }
 874                 }
 875               else
 876                 {
 877                   discard_candidate = 1;
 878                 }
 879             }
 880           else
 881             {
 882               discard_candidate = 1;
 883             }
 884           if (discard_candidate)
 885             {
 886               u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi;
 887               // discard candidate range, probe next range
 888               rc =
 889                 ip4_reass_remove_range_from_chain (vm, node, rm, reass,
 890                                                    prev_range_bi,
 891                                                    candidate_range_bi);
 892               if (IP4_REASS_RC_OK != rc)
 893                 {
 894                   return rc;
 895                 }
 896               if (~0 != next_range_bi)
 897                 {
 898                   candidate_range_bi = next_range_bi;
 899                   continue;
 900                 }
 901               else
 902                 {
 903                   // special case - last range discarded
 904                   rc =
 905                     ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 906                                                      prev_range_bi, *bi0);
 907                   if (IP4_REASS_RC_OK != rc)
 908                     {
 909                       return rc;
 910                     }
 911                   consumed = 1;
 912                 }
 913             }
 914         }
 915       break;
 916     }
 917   ++reass->fragments_n;
 918   if (consumed)
 919     {
 920       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 921         {
 922           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 923         }
 924     }
 925   if (~0 != reass->last_packet_octet &&
 926       reass->data_len == reass->last_packet_octet + 1)
 927     {
 928       return ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 929                                  is_feature);
 930     }
 931   else
 932     {
 933       if (consumed)
 934         {
 935           *bi0 = ~0;
 936           if (reass->fragments_n > rm->max_reass_len)
 937             {
 938               rc = IP4_REASS_RC_TOO_MANY_FRAGMENTS;
 939             }
 940         }
 941       else
 942         {
 943           *next0 = IP4_REASSEMBLY_NEXT_DROP;
 944           *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT;
 945         }
 946     }
 947   return rc;
 948 }
 949
 950 always_inline uword
 951 ip4_reassembly_inline (vlib_main_t * vm,
 952                        vlib_node_runtime_t * node,
 953                        vlib_frame_t * frame, bool is_feature)
 954 {
 955   u32 *from = vlib_frame_vector_args (frame);
 956   u32 n_left_from, n_left_to_next, *to_next, next_index;
 957   ip4_reass_main_t *rm = &ip4_reass_main;
 958   ip4_reass_per_thread_t *rt = &rm->per_thread_data[vm->thread_index];
 959   clib_spinlock_lock (&rt->lock);
 960
 961   n_left_from = frame->n_vectors;
 962   next_index = node->cached_next_index;
 963   while (n_left_from > 0)
 964     {
 965       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 966
 967       while (n_left_from > 0 && n_left_to_next > 0)
 968         {
 969           u32 bi0;
 970           vlib_buffer_t *b0;
 971           u32 next0;
 972           u32 error0 = IP4_ERROR_NONE;
 973
 974           bi0 = from[0];
 975           b0 = vlib_get_buffer (vm, bi0);
 976
 977           ip4_header_t *ip0 = vlib_buffer_get_current (b0);
 978           if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
 979             {
 980               // this is a whole packet - no fragmentation
 981               if (is_feature)
 982                 {
 983                   next0 = IP4_REASSEMBLY_NEXT_INPUT;
 984                 }
 985               else
 986                 {
 987                   next0 = vnet_buffer (b0)->ip.reass.next_index;
 988                 }
 989             }
 990           else
 991             {
 992               const u32 fragment_first = ip4_get_fragment_offset_bytes (ip0);
 993               const u32 fragment_length =
 994                 clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0);
 995               const u32 fragment_last = fragment_first + fragment_length - 1;
 996               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
 997                 {
 998                   next0 = IP4_REASSEMBLY_NEXT_DROP;
 999                   error0 = IP4_ERROR_REASS_MALFORMED_PACKET;
1000                 }
1001               else
1002                 {
1003                   ip4_reass_kv_t kv;
1004                   u8 do_handoff = 0;
1005
1006                   kv.k.as_u64[0] =
1007                     (u64) vec_elt (ip4_main.fib_index_by_sw_if_index,
1008                                    vnet_buffer (b0)->sw_if_index[VLIB_RX]) |
1009                     (u64) ip0->src_address.as_u32 << 32;
1010                   kv.k.as_u64[1] =
1011                     (u64) ip0->dst_address.as_u32 |
1012                     (u64) ip0->fragment_id << 32 | (u64) ip0->protocol << 48;
1013
1014                   ip4_reass_t *reass =
1015                     ip4_reass_find_or_create (vm, rm, rt, &kv, &do_handoff);
1016
1017                   if (PREDICT_FALSE (do_handoff))
1018                     {
1019                       next0 = IP4_REASSEMBLY_NEXT_HANDOFF;
1020                       if (is_feature)
1021                         vnet_buffer (b0)->ip.
1022                           reass.owner_feature_thread_index =
1023                           kv.v.thread_index;
1024                       else
1025                         vnet_buffer (b0)->ip.reass.owner_thread_index =
1026                           kv.v.thread_index;
1027                     }
1028                   else if (reass)
1029                     {
1030                       switch (ip4_reass_update
1031                               (vm, node, rm, rt, reass, &bi0, &next0,
1032                                &error0, is_feature))
1033                         {
1034                         case IP4_REASS_RC_OK:
1035                           /* nothing to do here */
1036                           break;
1037                         case IP4_REASS_RC_TOO_MANY_FRAGMENTS:
1038                           vlib_node_increment_counter (vm, node->node_index,
1039                                                        IP4_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
1040                                                        1);
1041                           ip4_reass_on_timeout (vm, rm, reass);
1042                           ip4_reass_free (rm, rt, reass);
1043                           goto next_packet;
1044                           break;
1045                         case IP4_REASS_RC_NO_BUF:
1046                           vlib_node_increment_counter (vm, node->node_index,
1047                                                        IP4_ERROR_REASS_NO_BUF,
1048                                                        1);
1049                           ip4_reass_on_timeout (vm, rm, reass);
1050                           ip4_reass_free (rm, rt, reass);
1051                           goto next_packet;
1052                           break;
1053                         case IP4_REASS_RC_INTERNAL_ERROR:
1054                           vlib_node_increment_counter (vm, node->node_index,
1055                                                        IP4_ERROR_REASS_INTERNAL_ERROR,
1056                                                        1);
1057                           ip4_reass_on_timeout (vm, rm, reass);
1058                           ip4_reass_free (rm, rt, reass);
1059                           goto next_packet;
1060                           break;
1061                         }
1062                     }
1063                   else
1064                     {
1065                       next0 = IP4_REASSEMBLY_NEXT_DROP;
1066                       error0 = IP4_ERROR_REASS_LIMIT_REACHED;
1067                     }
1068                 }
1069
1070               b0->error = node->errors[error0];
1071             }
1072
1073           if (bi0 != ~0)
1074             {
1075               to_next[0] = bi0;
1076               to_next += 1;
1077               n_left_to_next -= 1;
1078               if (is_feature && IP4_ERROR_NONE == error0)
1079                 {
1080                   b0 = vlib_get_buffer (vm, bi0);
1081                   vnet_feature_next (&next0, b0);
1082                 }
1083               vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1084                                                to_next, n_left_to_next,
1085                                                bi0, next0);
1086               IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next);
1087             }
1088
1089         next_packet:
1090           from += 1;
1091           n_left_from -= 1;
1092         }
1093
1094       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1095     }
1096
1097   clib_spinlock_unlock (&rt->lock);
1098   return frame->n_vectors;
1099 }
1100
1101 static char *ip4_reassembly_error_strings[] = {
1102 #define _(sym, string) string,
1103   foreach_ip4_error
1104 #undef _
1105 };
1106
1107 VLIB_NODE_FN (ip4_reass_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
1108                                vlib_frame_t * frame)
1109 {
1110   return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ );
1111 }
1112
1113 /* *INDENT-OFF* */
1114 VLIB_REGISTER_NODE (ip4_reass_node) = {
1115     .name = "ip4-reassembly",
1116     .vector_size = sizeof (u32),
1117     .format_trace = format_ip4_reass_trace,
1118     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1119     .error_strings = ip4_reassembly_error_strings,
1120     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1121     .next_nodes =
1122         {
1123                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1124                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1125                 [IP4_REASSEMBLY_NEXT_HANDOFF] = "ip4-reassembly-handoff",
1126
1127         },
1128 };
1129 /* *INDENT-ON* */
1130
1131 VLIB_NODE_FN (ip4_reass_node_feature) (vlib_main_t * vm,
1132                                        vlib_node_runtime_t * node,
1133                                        vlib_frame_t * frame)
1134 {
1135   return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ );
1136 }
1137
1138 /* *INDENT-OFF* */
1139 VLIB_REGISTER_NODE (ip4_reass_node_feature) = {
1140     .name = "ip4-reassembly-feature",
1141     .vector_size = sizeof (u32),
1142     .format_trace = format_ip4_reass_trace,
1143     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1144     .error_strings = ip4_reassembly_error_strings,
1145     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1146     .next_nodes =
1147         {
1148                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1149                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1150                 [IP4_REASSEMBLY_NEXT_HANDOFF] = "ip4-reass-feature-hoff",
1151         },
1152 };
1153 /* *INDENT-ON* */
1154
1155 /* *INDENT-OFF* */
1156 VNET_FEATURE_INIT (ip4_reassembly_feature, static) = {
1157     .arc_name = "ip4-unicast",
1158     .node_name = "ip4-reassembly-feature",
1159     .runs_before = VNET_FEATURES ("ip4-lookup"),
1160     .runs_after = 0,
1161 };
1162 /* *INDENT-ON* */
1163
1164 #ifndef CLIB_MARCH_VARIANT
1165 always_inline u32
1166 ip4_reass_get_nbuckets ()
1167 {
1168   ip4_reass_main_t *rm = &ip4_reass_main;
1169   u32 nbuckets;
1170   u8 i;
1171
1172   nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR);
1173
1174   for (i = 0; i < 31; i++)
1175     if ((1 << i) >= nbuckets)
1176       break;
1177   nbuckets = 1 << i;
1178
1179   return nbuckets;
1180 }
1181 #endif /* CLIB_MARCH_VARIANT */
1182
1183 typedef enum
1184 {
1185   IP4_EVENT_CONFIG_CHANGED = 1,
1186 } ip4_reass_event_t;
1187
1188 typedef struct
1189 {
1190   int failure;
1191   clib_bihash_16_8_t *new_hash;
1192 } ip4_rehash_cb_ctx;
1193
1194 #ifndef CLIB_MARCH_VARIANT
1195 static void
1196 ip4_rehash_cb (clib_bihash_kv_16_8_t * kv, void *_ctx)
1197 {
1198   ip4_rehash_cb_ctx *ctx = _ctx;
1199   if (clib_bihash_add_del_16_8 (ctx->new_hash, kv, 1))
1200     {
1201       ctx->failure = 1;
1202     }
1203 }
1204
1205 static void
1206 ip4_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1207                       u32 max_reassembly_length, u32 expire_walk_interval_ms)
1208 {
1209   ip4_reass_main.timeout_ms = timeout_ms;
1210   ip4_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1211   ip4_reass_main.max_reass_n = max_reassemblies;
1212   ip4_reass_main.max_reass_len = max_reassembly_length;
1213   ip4_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1214 }
1215
1216 vnet_api_error_t
1217 ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
1218                u32 max_reassembly_length, u32 expire_walk_interval_ms)
1219 {
1220   u32 old_nbuckets = ip4_reass_get_nbuckets ();
1221   ip4_reass_set_params (timeout_ms, max_reassemblies, max_reassembly_length,
1222                         expire_walk_interval_ms);
1223   vlib_process_signal_event (ip4_reass_main.vlib_main,
1224                              ip4_reass_main.ip4_reass_expire_node_idx,
1225                              IP4_EVENT_CONFIG_CHANGED, 0);
1226   u32 new_nbuckets = ip4_reass_get_nbuckets ();
1227   if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1228     {
1229       clib_bihash_16_8_t new_hash;
1230       clib_memset (&new_hash, 0, sizeof (new_hash));
1231       ip4_rehash_cb_ctx ctx;
1232       ctx.failure = 0;
1233       ctx.new_hash = &new_hash;
1234       clib_bihash_init_16_8 (&new_hash, "ip4-reass", new_nbuckets,
1235                              new_nbuckets * 1024);
1236       clib_bihash_foreach_key_value_pair_16_8 (&ip4_reass_main.hash,
1237                                                ip4_rehash_cb, &ctx);
1238       if (ctx.failure)
1239         {
1240           clib_bihash_free_16_8 (&new_hash);
1241           return -1;
1242         }
1243       else
1244         {
1245           clib_bihash_free_16_8 (&ip4_reass_main.hash);
1246           clib_memcpy_fast (&ip4_reass_main.hash, &new_hash,
1247                             sizeof (ip4_reass_main.hash));
1248         }
1249     }
1250   return 0;
1251 }
1252
1253 vnet_api_error_t
1254 ip4_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1255                u32 * max_reassembly_length, u32 * expire_walk_interval_ms)
1256 {
1257   *timeout_ms = ip4_reass_main.timeout_ms;
1258   *max_reassemblies = ip4_reass_main.max_reass_n;
1259   *max_reassembly_length = ip4_reass_main.max_reass_len;
1260   *expire_walk_interval_ms = ip4_reass_main.expire_walk_interval_ms;
1261   return 0;
1262 }
1263
1264 static clib_error_t *
1265 ip4_reass_init_function (vlib_main_t * vm)
1266 {
1267   ip4_reass_main_t *rm = &ip4_reass_main;
1268   clib_error_t *error = 0;
1269   u32 nbuckets;
1270   vlib_node_t *node;
1271
1272   rm->vlib_main = vm;
1273   rm->vnet_main = vnet_get_main ();
1274
1275   vec_validate (rm->per_thread_data, vlib_num_workers ());
1276   ip4_reass_per_thread_t *rt;
1277   vec_foreach (rt, rm->per_thread_data)
1278   {
1279     clib_spinlock_init (&rt->lock);
1280     pool_alloc (rt->pool, rm->max_reass_n);
1281   }
1282
1283   node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk");
1284   ASSERT (node);
1285   rm->ip4_reass_expire_node_idx = node->index;
1286
1287   ip4_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS,
1288                         IP4_REASS_MAX_REASSEMBLIES_DEFAULT,
1289                         IP4_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT,
1290                         IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1291
1292   nbuckets = ip4_reass_get_nbuckets ();
1293   clib_bihash_init_16_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024);
1294
1295   node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
1296   ASSERT (node);
1297   rm->ip4_drop_idx = node->index;
1298
1299   rm->fq_index = vlib_frame_queue_main_init (ip4_reass_node.index, 0);
1300   rm->fq_feature_index =
1301     vlib_frame_queue_main_init (ip4_reass_node_feature.index, 0);
1302
1303
1304   return error;
1305 }
1306
1307 VLIB_INIT_FUNCTION (ip4_reass_init_function);
1308 #endif /* CLIB_MARCH_VARIANT */
1309
1310 static uword
1311 ip4_reass_walk_expired (vlib_main_t * vm,
1312                         vlib_node_runtime_t * node, vlib_frame_t * f)
1313 {
1314   ip4_reass_main_t *rm = &ip4_reass_main;
1315   uword event_type, *event_data = 0;
1316
1317   while (true)
1318     {
1319       vlib_process_wait_for_event_or_clock (vm,
1320                                             (f64)
1321                                             rm->expire_walk_interval_ms /
1322                                             (f64) MSEC_PER_SEC);
1323       event_type = vlib_process_get_events (vm, &event_data);
1324
1325       switch (event_type)
1326         {
1327         case ~0:                /* no events => timeout */
1328           /* nothing to do here */
1329           break;
1330         case IP4_EVENT_CONFIG_CHANGED:
1331           break;
1332         default:
1333           clib_warning ("BUG: event type 0x%wx", event_type);
1334           break;
1335         }
1336       f64 now = vlib_time_now (vm);
1337
1338       ip4_reass_t *reass;
1339       int *pool_indexes_to_free = NULL;
1340
1341       uword thread_index = 0;
1342       int index;
1343       const uword nthreads = vlib_num_workers () + 1;
1344       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1345         {
1346           ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1347           clib_spinlock_lock (&rt->lock);
1348
1349           vec_reset_length (pool_indexes_to_free);
1350           /* *INDENT-OFF* */
1351           pool_foreach_index (index, rt->pool, ({
1352                                 reass = pool_elt_at_index (rt->pool, index);
1353                                 if (now > reass->last_heard + rm->timeout)
1354                                   {
1355                                     vec_add1 (pool_indexes_to_free, index);
1356                                   }
1357                               }));
1358           /* *INDENT-ON* */
1359           int *i;
1360           /* *INDENT-OFF* */
1361           vec_foreach (i, pool_indexes_to_free)
1362           {
1363             ip4_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1364             ip4_reass_on_timeout (vm, rm, reass);
1365             ip4_reass_free (rm, rt, reass);
1366           }
1367           /* *INDENT-ON* */
1368
1369           clib_spinlock_unlock (&rt->lock);
1370         }
1371
1372       vec_free (pool_indexes_to_free);
1373       if (event_data)
1374         {
1375           _vec_len (event_data) = 0;
1376         }
1377     }
1378
1379   return 0;
1380 }
1381
1382 /* *INDENT-OFF* */
1383 VLIB_REGISTER_NODE (ip4_reass_expire_node, static) = {
1384     .function = ip4_reass_walk_expired,
1385     .type = VLIB_NODE_TYPE_PROCESS,
1386     .name = "ip4-reassembly-expire-walk",
1387     .format_trace = format_ip4_reass_trace,
1388     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1389     .error_strings = ip4_reassembly_error_strings,
1390
1391 };
1392 /* *INDENT-ON* */
1393
1394 static u8 *
1395 format_ip4_reass_key (u8 * s, va_list * args)
1396 {
1397   ip4_reass_key_t *key = va_arg (*args, ip4_reass_key_t *);
1398   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1399               key->xx_id, format_ip4_address, &key->src, format_ip4_address,
1400               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1401   return s;
1402 }
1403
1404 static u8 *
1405 format_ip4_reass (u8 * s, va_list * args)
1406 {
1407   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1408   ip4_reass_t *reass = va_arg (*args, ip4_reass_t *);
1409
1410   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1411               "last_packet_octet: %u, trace_op_counter: %u\n",
1412               reass->id, format_ip4_reass_key, &reass->key, reass->first_bi,
1413               reass->data_len, reass->last_packet_octet,
1414               reass->trace_op_counter);
1415   u32 bi = reass->first_bi;
1416   u32 counter = 0;
1417   while (~0 != bi)
1418     {
1419       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1420       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1421       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1422                   "fragment[%u, %u]\n",
1423                   counter, vnb->ip.reass.range_first,
1424                   vnb->ip.reass.range_last, bi,
1425                   ip4_reass_buffer_get_data_offset (b),
1426                   ip4_reass_buffer_get_data_len (b),
1427                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1428       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1429         {
1430           bi = b->next_buffer;
1431         }
1432       else
1433         {
1434           bi = ~0;
1435         }
1436     }
1437   return s;
1438 }
1439
1440 static clib_error_t *
1441 show_ip4_reass (vlib_main_t * vm,
1442                 unformat_input_t * input,
1443                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1444 {
1445   ip4_reass_main_t *rm = &ip4_reass_main;
1446
1447   vlib_cli_output (vm, "---------------------");
1448   vlib_cli_output (vm, "IP4 reassembly status");
1449   vlib_cli_output (vm, "---------------------");
1450   bool details = false;
1451   if (unformat (input, "details"))
1452     {
1453       details = true;
1454     }
1455
1456   u32 sum_reass_n = 0;
1457   ip4_reass_t *reass;
1458   uword thread_index;
1459   const uword nthreads = vlib_num_workers () + 1;
1460   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1461     {
1462       ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1463       clib_spinlock_lock (&rt->lock);
1464       if (details)
1465         {
1466           /* *INDENT-OFF* */
1467           pool_foreach (reass, rt->pool, {
1468             vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass);
1469           });
1470           /* *INDENT-ON* */
1471         }
1472       sum_reass_n += rt->reass_n;
1473       clib_spinlock_unlock (&rt->lock);
1474     }
1475   vlib_cli_output (vm, "---------------------");
1476   vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
1477                    (long unsigned) sum_reass_n);
1478   vlib_cli_output (vm,
1479                    "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
1480                    (long unsigned) rm->max_reass_n);
1481   return 0;
1482 }
1483
1484 /* *INDENT-OFF* */
1485 VLIB_CLI_COMMAND (show_ip4_reassembly_cmd, static) = {
1486     .path = "show ip4-reassembly",
1487     .short_help = "show ip4-reassembly [details]",
1488     .function = show_ip4_reass,
1489 };
1490 /* *INDENT-ON* */
1491
1492 #ifndef CLIB_MARCH_VARIANT
1493 vnet_api_error_t
1494 ip4_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1495 {
1496   return vnet_feature_enable_disable ("ip4-unicast",
1497                                       "ip4-reassembly-feature", sw_if_index,
1498                                       enable_disable, 0, 0);
1499 }
1500 #endif /* CLIB_MARCH_VARIANT */
1501
1502
1503 #define foreach_ip4_reassembly_handoff_error                       \
1504 _(CONGESTION_DROP, "congestion drop")
1505
1506
1507 typedef enum
1508 {
1509 #define _(sym,str) IP4_REASSEMBLY_HANDOFF_ERROR_##sym,
1510   foreach_ip4_reassembly_handoff_error
1511 #undef _
1512     IP4_REASSEMBLY_HANDOFF_N_ERROR,
1513 } ip4_reassembly_handoff_error_t;
1514
1515 static char *ip4_reassembly_handoff_error_strings[] = {
1516 #define _(sym,string) string,
1517   foreach_ip4_reassembly_handoff_error
1518 #undef _
1519 };
1520
1521 typedef struct
1522 {
1523   u32 next_worker_index;
1524 } ip4_reassembly_handoff_trace_t;
1525
1526 static u8 *
1527 format_ip4_reassembly_handoff_trace (u8 * s, va_list * args)
1528 {
1529   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1530   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1531   ip4_reassembly_handoff_trace_t *t =
1532     va_arg (*args, ip4_reassembly_handoff_trace_t *);
1533
1534   s =
1535     format (s, "ip4-reassembly-handoff: next-worker %d",
1536             t->next_worker_index);
1537
1538   return s;
1539 }
1540
1541 always_inline uword
1542 ip4_reassembly_handoff_node_inline (vlib_main_t * vm,
1543                                     vlib_node_runtime_t * node,
1544                                     vlib_frame_t * frame, bool is_feature)
1545 {
1546   ip4_reass_main_t *rm = &ip4_reass_main;
1547
1548   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
1549   u32 n_enq, n_left_from, *from;
1550   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
1551   u32 fq_index;
1552
1553   from = vlib_frame_vector_args (frame);
1554   n_left_from = frame->n_vectors;
1555   vlib_get_buffers (vm, from, bufs, n_left_from);
1556
1557   b = bufs;
1558   ti = thread_indices;
1559
1560   fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index;
1561
1562   while (n_left_from > 0)
1563     {
1564       ti[0] =
1565         (is_feature) ? vnet_buffer (b[0])->ip.
1566         reass.owner_feature_thread_index : vnet_buffer (b[0])->ip.
1567         reass.owner_thread_index;
1568
1569       if (PREDICT_FALSE
1570           ((node->flags & VLIB_NODE_FLAG_TRACE)
1571            && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
1572         {
1573           ip4_reassembly_handoff_trace_t *t =
1574             vlib_add_trace (vm, node, b[0], sizeof (*t));
1575           t->next_worker_index = ti[0];
1576         }
1577
1578       n_left_from -= 1;
1579       ti += 1;
1580       b += 1;
1581     }
1582   n_enq =
1583     vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
1584                                    frame->n_vectors, 1);
1585
1586   if (n_enq < frame->n_vectors)
1587     vlib_node_increment_counter (vm, node->node_index,
1588                                  IP4_REASSEMBLY_HANDOFF_ERROR_CONGESTION_DROP,
1589                                  frame->n_vectors - n_enq);
1590   return frame->n_vectors;
1591 }
1592
1593 VLIB_NODE_FN (ip4_reassembly_handoff_node) (vlib_main_t * vm,
1594                                             vlib_node_runtime_t * node,
1595                                             vlib_frame_t * frame)
1596 {
1597   return ip4_reassembly_handoff_node_inline (vm, node, frame,
1598                                              false /* is_feature */ );
1599 }
1600
1601
1602 /* *INDENT-OFF* */
1603 VLIB_REGISTER_NODE (ip4_reassembly_handoff_node) = {
1604   .name = "ip4-reassembly-handoff",
1605   .vector_size = sizeof (u32),
1606   .n_errors = ARRAY_LEN(ip4_reassembly_handoff_error_strings),
1607   .error_strings = ip4_reassembly_handoff_error_strings,
1608   .format_trace = format_ip4_reassembly_handoff_trace,
1609
1610   .n_next_nodes = 1,
1611
1612   .next_nodes = {
1613     [0] = "error-drop",
1614   },
1615 };
1616 /* *INDENT-ON* */
1617
1618
1619 /* *INDENT-OFF* */
1620 VLIB_NODE_FN (ip4_reassembly_feature_handoff_node) (vlib_main_t * vm,
1621                                                     vlib_node_runtime_t *
1622                                                     node,
1623                                                     vlib_frame_t * frame)
1624 {
1625   return ip4_reassembly_handoff_node_inline (vm, node, frame,
1626                                              true /* is_feature */ );
1627 }
1628 /* *INDENT-ON* */
1629
1630
1631 /* *INDENT-OFF* */
1632 VLIB_REGISTER_NODE (ip4_reassembly_feature_handoff_node) = {
1633   .name = "ip4-reass-feature-hoff",
1634   .vector_size = sizeof (u32),
1635   .n_errors = ARRAY_LEN(ip4_reassembly_handoff_error_strings),
1636   .error_strings = ip4_reassembly_handoff_error_strings,
1637   .format_trace = format_ip4_reassembly_handoff_trace,
1638
1639   .n_next_nodes = 1,
1640
1641   .next_nodes = {
1642     [0] = "error-drop",
1643   },
1644 };
1645 /* *INDENT-ON* */
1646
1647 /*
1648  * fd.io coding-style-patch-verification: ON
1649  *
1650  * Local Variables:
1651  * eval: (c-set-style "gnu")
1652  * End:
1653  */