src/vnet/ip/ip6_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 IPv6 Reassembly.
  19  *
  20  * This file contains the source code for IPv6 reassembly.
  21  */
  22
  23 #include <vppinfra/vec.h>
  24 #include <vnet/vnet.h>
  25 #include <vnet/ip/ip.h>
  26 #include <vppinfra/bihash_48_8.h>
  27 #include <vnet/ip/ip6_reassembly.h>
  28
  29 #define MSEC_PER_SEC 1000
  30 #define IP6_REASS_TIMEOUT_DEFAULT_MS 100
  31 #define IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000 // 10 seconds default
  32 #define IP6_REASS_MAX_REASSEMBLIES_DEFAULT 1024
  33 #define IP6_REASS_HT_LOAD_FACTOR (0.75)
  34
  35 typedef enum
  36 {
  37   IP6_REASS_RC_OK,
  38   IP6_REASS_RC_INTERNAL_ERROR,
  39   IP6_REASS_RC_NO_BUF,
  40 } ip6_reass_rc_t;
  41
  42 typedef struct
  43 {
  44   union
  45   {
  46     struct
  47     {
  48       ip6_address_t src;
  49       ip6_address_t dst;
  50       u32 xx_id;
  51       u32 frag_id;
  52       u8 unused[7];
  53       u8 proto;
  54     };
  55     u64 as_u64[6];
  56   };
  57 } ip6_reass_key_t;
  58
  59 typedef union
  60 {
  61   struct
  62   {
  63     u32 reass_index;
  64     u32 thread_index;
  65   };
  66   u64 as_u64;
  67 } ip6_reass_val_t;
  68
  69 typedef union
  70 {
  71   struct
  72   {
  73     ip6_reass_key_t k;
  74     ip6_reass_val_t v;
  75   };
  76   clib_bihash_kv_48_8_t kv;
  77 } ip6_reass_kv_t;
  78
  79
  80 always_inline u32
  81 ip6_reass_buffer_get_data_offset (vlib_buffer_t * b)
  82 {
  83   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  84   return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
  85 }
  86
  87 always_inline u16
  88 ip6_reass_buffer_get_data_len (vlib_buffer_t * b)
  89 {
  90   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  91   return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
  92     (vnb->ip.reass.fragment_first + ip6_reass_buffer_get_data_offset (b)) + 1;
  93 }
  94
  95 typedef struct
  96 {
  97   // hash table key
  98   ip6_reass_key_t key;
  99   // time when last packet was received
 100   f64 last_heard;
 101   // internal id of this reassembly
 102   u64 id;
 103   // buffer index of first buffer in this reassembly context
 104   u32 first_bi;
 105   // last octet of packet, ~0 until fragment without more_fragments arrives
 106   u32 last_packet_octet;
 107   // length of data collected so far
 108   u32 data_len;
 109   // trace operation counter
 110   u32 trace_op_counter;
 111   // next index - used by non-feature node
 112   u8 next_index;
 113   // minimum fragment length for this reassembly - used to estimate MTU
 114   u16 min_fragment_length;
 115 } ip6_reass_t;
 116
 117 typedef struct
 118 {
 119   ip6_reass_t *pool;
 120   u32 reass_n;
 121   u32 id_counter;
 122   clib_spinlock_t lock;
 123 } ip6_reass_per_thread_t;
 124
 125 typedef struct
 126 {
 127   // IPv6 config
 128   u32 timeout_ms;
 129   f64 timeout;
 130   u32 expire_walk_interval_ms;
 131   u32 max_reass_n;
 132
 133   // IPv6 runtime
 134   clib_bihash_48_8_t hash;
 135
 136   // per-thread data
 137   ip6_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 ip6-drop node
 144   u32 ip6_drop_idx;
 145   u32 ip6_icmp_error_idx;
 146   u32 ip6_reass_expire_node_idx;
 147
 148   /** Worker handoff */
 149   u32 fq_index;
 150   u32 fq_feature_index;
 151
 152 } ip6_reass_main_t;
 153
 154 ip6_reass_main_t ip6_reass_main;
 155
 156 typedef enum
 157 {
 158   IP6_REASSEMBLY_NEXT_INPUT,
 159   IP6_REASSEMBLY_NEXT_DROP,
 160   IP6_REASSEMBLY_NEXT_ICMP_ERROR,
 161   IP6_REASSEMBLY_NEXT_HANDOFF,
 162   IP6_REASSEMBLY_N_NEXT,
 163 } ip6_reass_next_t;
 164
 165 typedef enum
 166 {
 167   RANGE_NEW,
 168   RANGE_OVERLAP,
 169   ICMP_ERROR_RT_EXCEEDED,
 170   ICMP_ERROR_FL_TOO_BIG,
 171   ICMP_ERROR_FL_NOT_MULT_8,
 172   FINALIZE,
 173 } ip6_reass_trace_operation_e;
 174
 175 typedef struct
 176 {
 177   u16 range_first;
 178   u16 range_last;
 179   u32 range_bi;
 180   i32 data_offset;
 181   u32 data_len;
 182   u32 first_bi;
 183 } ip6_reass_range_trace_t;
 184
 185 typedef struct
 186 {
 187   ip6_reass_trace_operation_e action;
 188   u32 reass_id;
 189   ip6_reass_range_trace_t trace_range;
 190   u32 size_diff;
 191   u32 op_id;
 192   u32 fragment_first;
 193   u32 fragment_last;
 194   u32 total_data_len;
 195 } ip6_reass_trace_t;
 196
 197 static void
 198 ip6_reass_trace_details (vlib_main_t * vm, u32 bi,
 199                          ip6_reass_range_trace_t * trace)
 200 {
 201   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 202   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 203   trace->range_first = vnb->ip.reass.range_first;
 204   trace->range_last = vnb->ip.reass.range_last;
 205   trace->data_offset = ip6_reass_buffer_get_data_offset (b);
 206   trace->data_len = ip6_reass_buffer_get_data_len (b);
 207   trace->range_bi = bi;
 208 }
 209
 210 static u8 *
 211 format_ip6_reass_range_trace (u8 * s, va_list * args)
 212 {
 213   ip6_reass_range_trace_t *trace = va_arg (*args, ip6_reass_range_trace_t *);
 214   s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
 215               trace->range_last, trace->data_offset, trace->data_len,
 216               trace->range_bi);
 217   return s;
 218 }
 219
 220 static u8 *
 221 format_ip6_reass_trace (u8 * s, va_list * args)
 222 {
 223   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 224   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 225   ip6_reass_trace_t *t = va_arg (*args, ip6_reass_trace_t *);
 226   s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
 227   u32 indent = format_get_indent (s);
 228   s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
 229               t->trace_range.first_bi, t->total_data_len, t->fragment_first,
 230               t->fragment_last);
 231   switch (t->action)
 232     {
 233     case RANGE_NEW:
 234       s = format (s, "\n%Unew %U", format_white_space, indent,
 235                   format_ip6_reass_range_trace, &t->trace_range);
 236       break;
 237     case RANGE_OVERLAP:
 238       s = format (s, "\n%Uoverlap %U", format_white_space, indent,
 239                   format_ip6_reass_range_trace, &t->trace_range);
 240       break;
 241     case ICMP_ERROR_FL_TOO_BIG:
 242       s = format (s, "\n%Uicmp-error - frag_len > 65535 %U",
 243                   format_white_space, indent, format_ip6_reass_range_trace,
 244                   &t->trace_range);
 245       break;
 246     case ICMP_ERROR_FL_NOT_MULT_8:
 247       s = format (s, "\n%Uicmp-error - frag_len mod 8 != 0 %U",
 248                   format_white_space, indent, format_ip6_reass_range_trace,
 249                   &t->trace_range);
 250       break;
 251     case ICMP_ERROR_RT_EXCEEDED:
 252       s = format (s, "\n%Uicmp-error - reassembly time exceeded",
 253                   format_white_space, indent);
 254       break;
 255     case FINALIZE:
 256       s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
 257       break;
 258     }
 259   return s;
 260 }
 261
 262 static void
 263 ip6_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 264                      ip6_reass_main_t * rm, ip6_reass_t * reass,
 265                      u32 bi, ip6_reass_trace_operation_e action,
 266                      u32 size_diff)
 267 {
 268   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 269   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 270   if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
 271     {
 272       // this buffer's trace is gone
 273       b->flags &= ~VLIB_BUFFER_IS_TRACED;
 274       return;
 275     }
 276   ip6_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 277   t->reass_id = reass->id;
 278   t->action = action;
 279   ip6_reass_trace_details (vm, bi, &t->trace_range);
 280   t->size_diff = size_diff;
 281   t->op_id = reass->trace_op_counter;
 282   ++reass->trace_op_counter;
 283   t->fragment_first = vnb->ip.reass.fragment_first;
 284   t->fragment_last = vnb->ip.reass.fragment_last;
 285   t->trace_range.first_bi = reass->first_bi;
 286   t->total_data_len = reass->data_len;
 287 #if 0
 288   static u8 *s = NULL;
 289   s = format (s, "%U", format_ip6_reass_trace, NULL, NULL, t);
 290   printf ("%.*s\n", vec_len (s), s);
 291   fflush (stdout);
 292   vec_reset_length (s);
 293 #endif
 294 }
 295
 296 always_inline void
 297 ip6_reass_free (ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 298                 ip6_reass_t * reass)
 299 {
 300   clib_bihash_kv_48_8_t kv;
 301   kv.key[0] = reass->key.as_u64[0];
 302   kv.key[1] = reass->key.as_u64[1];
 303   kv.key[2] = reass->key.as_u64[2];
 304   kv.key[3] = reass->key.as_u64[3];
 305   kv.key[4] = reass->key.as_u64[4];
 306   kv.key[5] = reass->key.as_u64[5];
 307   clib_bihash_add_del_48_8 (&rm->hash, &kv, 0);
 308   pool_put (rt->pool, reass);
 309   --rt->reass_n;
 310 }
 311
 312 always_inline void
 313 ip6_reass_drop_all (vlib_main_t * vm, ip6_reass_main_t * rm,
 314                     ip6_reass_t * reass)
 315 {
 316   u32 range_bi = reass->first_bi;
 317   vlib_buffer_t *range_b;
 318   vnet_buffer_opaque_t *range_vnb;
 319   u32 *to_free = NULL;
 320   while (~0 != range_bi)
 321     {
 322       range_b = vlib_get_buffer (vm, range_bi);
 323       range_vnb = vnet_buffer (range_b);
 324       u32 bi = range_bi;
 325       while (~0 != bi)
 326         {
 327           vec_add1 (to_free, bi);
 328           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 329           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 330             {
 331               bi = b->next_buffer;
 332               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 333             }
 334           else
 335             {
 336               bi = ~0;
 337             }
 338         }
 339       range_bi = range_vnb->ip.reass.next_range_bi;
 340     }
 341   vlib_buffer_free (vm, to_free, vec_len (to_free));
 342   vec_free (to_free);
 343 }
 344
 345 always_inline void
 346 ip6_reass_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * node,
 347                       ip6_reass_main_t * rm, ip6_reass_t * reass,
 348                       u32 * icmp_bi)
 349 {
 350   if (~0 == reass->first_bi)
 351     {
 352       return;
 353     }
 354   vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
 355   if (0 == vnet_buffer (b)->ip.reass.fragment_first)
 356     {
 357       *icmp_bi = reass->first_bi;
 358       if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
 359         {
 360           ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi,
 361                                ICMP_ERROR_RT_EXCEEDED, 0);
 362         }
 363       // fragment with offset zero received - send icmp message back
 364       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 365         {
 366           // separate first buffer from chain and steer it towards icmp node
 367           b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 368           reass->first_bi = b->next_buffer;
 369         }
 370       else
 371         {
 372           reass->first_bi = vnet_buffer (b)->ip.reass.next_range_bi;
 373         }
 374       icmp6_error_set_vnet_buffer (b, ICMP6_time_exceeded,
 375                                    ICMP6_time_exceeded_fragment_reassembly_time_exceeded,
 376                                    0);
 377     }
 378   ip6_reass_drop_all (vm, rm, reass);
 379 }
 380
 381 always_inline ip6_reass_t *
 382 ip6_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 383                           ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 384                           ip6_reass_kv_t * kv, u32 * icmp_bi, u8 * do_handoff)
 385 {
 386   ip6_reass_t *reass = NULL;
 387   f64 now = vlib_time_now (rm->vlib_main);
 388
 389   if (!clib_bihash_search_48_8
 390       (&rm->hash, (clib_bihash_kv_48_8_t *) kv, (clib_bihash_kv_48_8_t *) kv))
 391     {
 392       if (vm->thread_index != kv->v.thread_index)
 393         {
 394           *do_handoff = 1;
 395           return NULL;
 396         }
 397       reass = pool_elt_at_index (rt->pool, kv->v.reass_index);
 398
 399       if (now > reass->last_heard + rm->timeout)
 400         {
 401           ip6_reass_on_timeout (vm, node, rm, reass, icmp_bi);
 402           ip6_reass_free (rm, rt, reass);
 403           reass = NULL;
 404         }
 405     }
 406
 407   if (reass)
 408     {
 409       reass->last_heard = now;
 410       return reass;
 411     }
 412
 413   if (rt->reass_n >= rm->max_reass_n)
 414     {
 415       reass = NULL;
 416       return reass;
 417     }
 418   else
 419     {
 420       pool_get (rt->pool, reass);
 421       clib_memset (reass, 0, sizeof (*reass));
 422       reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter;
 423       ++rt->id_counter;
 424       reass->first_bi = ~0;
 425       reass->last_packet_octet = ~0;
 426       reass->data_len = 0;
 427       ++rt->reass_n;
 428     }
 429
 430   reass->key.as_u64[0] = ((clib_bihash_kv_48_8_t *) kv)->key[0];
 431   reass->key.as_u64[1] = ((clib_bihash_kv_48_8_t *) kv)->key[1];
 432   reass->key.as_u64[2] = ((clib_bihash_kv_48_8_t *) kv)->key[2];
 433   reass->key.as_u64[3] = ((clib_bihash_kv_48_8_t *) kv)->key[3];
 434   reass->key.as_u64[4] = ((clib_bihash_kv_48_8_t *) kv)->key[4];
 435   reass->key.as_u64[5] = ((clib_bihash_kv_48_8_t *) kv)->key[5];
 436   kv->v.reass_index = (reass - rt->pool);
 437   kv->v.thread_index = vm->thread_index;
 438   reass->last_heard = now;
 439
 440   if (clib_bihash_add_del_48_8 (&rm->hash, (clib_bihash_kv_48_8_t *) kv, 1))
 441     {
 442       ip6_reass_free (rm, rt, reass);
 443       reass = NULL;
 444     }
 445
 446   return reass;
 447 }
 448
 449 always_inline ip6_reass_rc_t
 450 ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 451                     ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 452                     ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 453                     bool is_feature)
 454 {
 455   *bi0 = reass->first_bi;
 456   *error0 = IP6_ERROR_NONE;
 457   ip6_frag_hdr_t *frag_hdr;
 458   vlib_buffer_t *last_b = NULL;
 459   u32 sub_chain_bi = reass->first_bi;
 460   u32 total_length = 0;
 461   u32 buf_cnt = 0;
 462   u32 dropped_cnt = 0;
 463   u32 *vec_drop_compress = NULL;
 464   ip6_reass_rc_t rv = IP6_REASS_RC_OK;
 465   do
 466     {
 467       u32 tmp_bi = sub_chain_bi;
 468       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 469       vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
 470       if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 471           !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 472         {
 473           rv = IP6_REASS_RC_INTERNAL_ERROR;
 474           goto free_buffers_and_return;
 475         }
 476
 477       u32 data_len = ip6_reass_buffer_get_data_len (tmp);
 478       u32 trim_front = vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 479         sizeof (*frag_hdr) + ip6_reass_buffer_get_data_offset (tmp);
 480       u32 trim_end =
 481         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 482       if (tmp_bi == reass->first_bi)
 483         {
 484           /* first buffer - keep ip6 header */
 485           if (0 != ip6_reass_buffer_get_data_offset (tmp))
 486             {
 487               rv = IP6_REASS_RC_INTERNAL_ERROR;
 488               goto free_buffers_and_return;
 489             }
 490           trim_front = 0;
 491           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 492             (vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 493              sizeof (*frag_hdr));
 494           if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
 495             {
 496               rv = IP6_REASS_RC_INTERNAL_ERROR;
 497               goto free_buffers_and_return;
 498             }
 499         }
 500       u32 keep_data =
 501         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 502       while (1)
 503         {
 504           ++buf_cnt;
 505           if (trim_front)
 506             {
 507               if (trim_front > tmp->current_length)
 508                 {
 509                   /* drop whole buffer */
 510                   vec_add1 (vec_drop_compress, tmp_bi);
 511                   trim_front -= tmp->current_length;
 512                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 513                     {
 514                       rv = IP6_REASS_RC_INTERNAL_ERROR;
 515                       goto free_buffers_and_return;
 516                     }
 517                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 518                   tmp_bi = tmp->next_buffer;
 519                   tmp = vlib_get_buffer (vm, tmp_bi);
 520                   continue;
 521                 }
 522               else
 523                 {
 524                   vlib_buffer_advance (tmp, trim_front);
 525                   trim_front = 0;
 526                 }
 527             }
 528           if (keep_data)
 529             {
 530               if (last_b)
 531                 {
 532                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 533                   last_b->next_buffer = tmp_bi;
 534                 }
 535               last_b = tmp;
 536               if (keep_data <= tmp->current_length)
 537                 {
 538                   tmp->current_length = keep_data;
 539                   keep_data = 0;
 540                 }
 541               else
 542                 {
 543                   keep_data -= tmp->current_length;
 544                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 545                     {
 546                       rv = IP6_REASS_RC_INTERNAL_ERROR;
 547                       goto free_buffers_and_return;
 548                     }
 549                 }
 550               total_length += tmp->current_length;
 551             }
 552           else
 553             {
 554               vec_add1 (vec_drop_compress, tmp_bi);
 555               if (reass->first_bi == tmp_bi)
 556                 {
 557                   rv = IP6_REASS_RC_INTERNAL_ERROR;
 558                   goto free_buffers_and_return;
 559                 }
 560               ++dropped_cnt;
 561             }
 562           if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 563             {
 564               tmp_bi = tmp->next_buffer;
 565               tmp = vlib_get_buffer (vm, tmp->next_buffer);
 566             }
 567           else
 568             {
 569               break;
 570             }
 571         }
 572       sub_chain_bi =
 573         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 574         reass.next_range_bi;
 575     }
 576   while (~0 != sub_chain_bi);
 577
 578   if (!last_b)
 579     {
 580       rv = IP6_REASS_RC_INTERNAL_ERROR;
 581       goto free_buffers_and_return;
 582     }
 583   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 584   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 585   if (total_length < first_b->current_length)
 586     {
 587       rv = IP6_REASS_RC_INTERNAL_ERROR;
 588       goto free_buffers_and_return;
 589     }
 590   total_length -= first_b->current_length;
 591   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 592   first_b->total_length_not_including_first_buffer = total_length;
 593   // drop fragment header
 594   vnet_buffer_opaque_t *first_b_vnb = vnet_buffer (first_b);
 595   ip6_header_t *ip = vlib_buffer_get_current (first_b);
 596   u16 ip6_frag_hdr_offset = first_b_vnb->ip.reass.ip6_frag_hdr_offset;
 597   ip6_ext_header_t *prev_hdr;
 598   ip6_ext_header_find_t (ip, prev_hdr, frag_hdr,
 599                          IP_PROTOCOL_IPV6_FRAGMENTATION);
 600   if (prev_hdr)
 601     {
 602       prev_hdr->next_hdr = frag_hdr->next_hdr;
 603     }
 604   else
 605     {
 606       ip->protocol = frag_hdr->next_hdr;
 607     }
 608   if (!((u8 *) frag_hdr - (u8 *) ip == ip6_frag_hdr_offset))
 609     {
 610       rv = IP6_REASS_RC_INTERNAL_ERROR;
 611       goto free_buffers_and_return;
 612     }
 613   memmove (frag_hdr, (u8 *) frag_hdr + sizeof (*frag_hdr),
 614            first_b->current_length - ip6_frag_hdr_offset -
 615            sizeof (ip6_frag_hdr_t));
 616   first_b->current_length -= sizeof (*frag_hdr);
 617   ip->payload_length =
 618     clib_host_to_net_u16 (total_length + first_b->current_length -
 619                           sizeof (*ip));
 620   if (!vlib_buffer_chain_linearize (vm, first_b))
 621     {
 622       rv = IP6_REASS_RC_NO_BUF;
 623       goto free_buffers_and_return;
 624     }
 625   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 626     {
 627       ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 628 #if 0
 629       // following code does a hexdump of packet fragments to stdout ...
 630       do
 631         {
 632           u32 bi = reass->first_bi;
 633           u8 *s = NULL;
 634           while (~0 != bi)
 635             {
 636               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 637               s = format (s, "%u: %U\n", bi, format_hexdump,
 638                           vlib_buffer_get_current (b), b->current_length);
 639               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 640                 {
 641                   bi = b->next_buffer;
 642                 }
 643               else
 644                 {
 645                   break;
 646                 }
 647             }
 648           printf ("%.*s\n", vec_len (s), s);
 649           fflush (stdout);
 650           vec_free (s);
 651         }
 652       while (0);
 653 #endif
 654     }
 655   if (is_feature)
 656     {
 657       *next0 = IP6_REASSEMBLY_NEXT_INPUT;
 658     }
 659   else
 660     {
 661       *next0 = reass->next_index;
 662     }
 663   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 664   ip6_reass_free (rm, rt, reass);
 665   reass = NULL;
 666 free_buffers_and_return:
 667   vlib_buffer_free (vm, vec_drop_compress, vec_len (vec_drop_compress));
 668   vec_free (vec_drop_compress);
 669   return rv;
 670 }
 671
 672 always_inline void
 673 ip6_reass_insert_range_in_chain (vlib_main_t * vm, ip6_reass_main_t * rm,
 674                                  ip6_reass_per_thread_t * rt,
 675                                  ip6_reass_t * reass, u32 prev_range_bi,
 676                                  u32 new_next_bi)
 677 {
 678
 679   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 680   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 681   if (~0 != prev_range_bi)
 682     {
 683       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 684       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 685       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 686       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 687     }
 688   else
 689     {
 690       if (~0 != reass->first_bi)
 691         {
 692           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 693         }
 694       reass->first_bi = new_next_bi;
 695     }
 696   reass->data_len += ip6_reass_buffer_get_data_len (new_next_b);
 697 }
 698
 699 always_inline ip6_reass_rc_t
 700 ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 701                   ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 702                   ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 703                   ip6_frag_hdr_t * frag_hdr, bool is_feature)
 704 {
 705   int consumed = 0;
 706   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 707   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 708   reass->next_index = fvnb->ip.reass.next_index;        // store next_index before it's overwritten
 709   fvnb->ip.reass.ip6_frag_hdr_offset =
 710     (u8 *) frag_hdr - (u8 *) vlib_buffer_get_current (fb);
 711   ip6_header_t *fip = vlib_buffer_get_current (fb);
 712   if (fb->current_length < sizeof (*fip) ||
 713       fvnb->ip.reass.ip6_frag_hdr_offset == 0 ||
 714       fvnb->ip.reass.ip6_frag_hdr_offset >= fb->current_length)
 715     {
 716       return IP6_REASS_RC_INTERNAL_ERROR;
 717     }
 718
 719   u32 fragment_first = fvnb->ip.reass.fragment_first =
 720     ip6_frag_hdr_offset_bytes (frag_hdr);
 721   u32 fragment_length =
 722     vlib_buffer_length_in_chain (vm, fb) -
 723     (fvnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 724   u32 fragment_last = fvnb->ip.reass.fragment_last =
 725     fragment_first + fragment_length - 1;
 726   int more_fragments = ip6_frag_hdr_more (frag_hdr);
 727   u32 candidate_range_bi = reass->first_bi;
 728   u32 prev_range_bi = ~0;
 729   fvnb->ip.reass.range_first = fragment_first;
 730   fvnb->ip.reass.range_last = fragment_last;
 731   fvnb->ip.reass.next_range_bi = ~0;
 732   if (!more_fragments)
 733     {
 734       reass->last_packet_octet = fragment_last;
 735     }
 736   if (~0 == reass->first_bi)
 737     {
 738       // starting a new reassembly
 739       ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 740                                        *bi0);
 741       reass->min_fragment_length = clib_net_to_host_u16 (fip->payload_length);
 742       consumed = 1;
 743       goto check_if_done_maybe;
 744     }
 745   reass->min_fragment_length =
 746     clib_min (clib_net_to_host_u16 (fip->payload_length),
 747               fvnb->ip.reass.estimated_mtu);
 748   while (~0 != candidate_range_bi)
 749     {
 750       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 751       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 752       if (fragment_first > candidate_vnb->ip.reass.range_last)
 753         {
 754           // this fragments starts after candidate range
 755           prev_range_bi = candidate_range_bi;
 756           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 757           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 758               ~0 == candidate_range_bi)
 759             {
 760               // special case - this fragment falls beyond all known ranges
 761               ip6_reass_insert_range_in_chain (vm, rm, rt, reass,
 762                                                prev_range_bi, *bi0);
 763               consumed = 1;
 764               break;
 765             }
 766           continue;
 767         }
 768       if (fragment_last < candidate_vnb->ip.reass.range_first)
 769         {
 770           // this fragment ends before candidate range without any overlap
 771           ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 772                                            *bi0);
 773           consumed = 1;
 774         }
 775       else if (fragment_first == candidate_vnb->ip.reass.range_first &&
 776                fragment_last == candidate_vnb->ip.reass.range_last)
 777         {
 778           // duplicate fragment - ignore
 779         }
 780       else
 781         {
 782           // overlapping fragment - not allowed by RFC 8200
 783           ip6_reass_drop_all (vm, rm, reass);
 784           ip6_reass_free (rm, rt, reass);
 785           if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 786             {
 787               ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_OVERLAP,
 788                                    0);
 789             }
 790           *next0 = IP6_REASSEMBLY_NEXT_DROP;
 791           *error0 = IP6_ERROR_REASS_OVERLAPPING_FRAGMENT;
 792           return IP6_REASS_RC_OK;
 793         }
 794       break;
 795     }
 796 check_if_done_maybe:
 797   if (consumed)
 798     {
 799       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 800         {
 801           ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 802         }
 803     }
 804   if (~0 != reass->last_packet_octet &&
 805       reass->data_len == reass->last_packet_octet + 1)
 806     {
 807       return ip6_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 808                                  is_feature);
 809     }
 810   else
 811     {
 812       if (consumed)
 813         {
 814           *bi0 = ~0;
 815         }
 816       else
 817         {
 818           *next0 = IP6_REASSEMBLY_NEXT_DROP;
 819           *error0 = IP6_ERROR_REASS_DUPLICATE_FRAGMENT;
 820         }
 821     }
 822   return IP6_REASS_RC_OK;
 823 }
 824
 825 always_inline bool
 826 ip6_reass_verify_upper_layer_present (vlib_node_runtime_t * node,
 827                                       vlib_buffer_t * b,
 828                                       ip6_frag_hdr_t * frag_hdr)
 829 {
 830   ip6_ext_header_t *tmp = (ip6_ext_header_t *) frag_hdr;
 831   while (ip6_ext_hdr (tmp->next_hdr))
 832     {
 833       tmp = ip6_ext_next_header (tmp);
 834     }
 835   if (IP_PROTOCOL_IP6_NONXT == tmp->next_hdr)
 836     {
 837       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 838                                    ICMP6_parameter_problem_first_fragment_has_incomplete_header_chain,
 839                                    0);
 840       b->error = node->errors[IP6_ERROR_REASS_MISSING_UPPER];
 841
 842       return false;
 843     }
 844   return true;
 845 }
 846
 847 always_inline bool
 848 ip6_reass_verify_fragment_multiple_8 (vlib_main_t * vm,
 849                                       vlib_node_runtime_t * node,
 850                                       vlib_buffer_t * b,
 851                                       ip6_frag_hdr_t * frag_hdr)
 852 {
 853   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 854   ip6_header_t *ip = vlib_buffer_get_current (b);
 855   int more_fragments = ip6_frag_hdr_more (frag_hdr);
 856   u32 fragment_length =
 857     vlib_buffer_length_in_chain (vm, b) -
 858     (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 859   if (more_fragments && 0 != fragment_length % 8)
 860     {
 861       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 862                                    ICMP6_parameter_problem_erroneous_header_field,
 863                                    (u8 *) & ip->payload_length - (u8 *) ip);
 864       return false;
 865     }
 866   return true;
 867 }
 868
 869 always_inline bool
 870 ip6_reass_verify_packet_size_lt_64k (vlib_main_t * vm,
 871                                      vlib_node_runtime_t * node,
 872                                      vlib_buffer_t * b,
 873                                      ip6_frag_hdr_t * frag_hdr)
 874 {
 875   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 876   u32 fragment_first = ip6_frag_hdr_offset_bytes (frag_hdr);
 877   u32 fragment_length =
 878     vlib_buffer_length_in_chain (vm, b) -
 879     (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 880   if (fragment_first + fragment_length > 65535)
 881     {
 882       ip6_header_t *ip0 = vlib_buffer_get_current (b);
 883       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 884                                    ICMP6_parameter_problem_erroneous_header_field,
 885                                    (u8 *) & frag_hdr->fragment_offset_and_more
 886                                    - (u8 *) ip0);
 887       return false;
 888     }
 889   return true;
 890 }
 891
 892 always_inline uword
 893 ip6_reassembly_inline (vlib_main_t * vm,
 894                        vlib_node_runtime_t * node,
 895                        vlib_frame_t * frame, bool is_feature)
 896 {
 897   u32 *from = vlib_frame_vector_args (frame);
 898   u32 n_left_from, n_left_to_next, *to_next, next_index;
 899   ip6_reass_main_t *rm = &ip6_reass_main;
 900   ip6_reass_per_thread_t *rt = &rm->per_thread_data[vm->thread_index];
 901   clib_spinlock_lock (&rt->lock);
 902
 903   n_left_from = frame->n_vectors;
 904   next_index = node->cached_next_index;
 905   while (n_left_from > 0)
 906     {
 907       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 908
 909       while (n_left_from > 0 && n_left_to_next > 0)
 910         {
 911           u32 bi0;
 912           vlib_buffer_t *b0;
 913           u32 next0 = IP6_REASSEMBLY_NEXT_DROP;
 914           u32 error0 = IP6_ERROR_NONE;
 915           u32 icmp_bi = ~0;
 916
 917           bi0 = from[0];
 918           b0 = vlib_get_buffer (vm, bi0);
 919
 920           ip6_header_t *ip0 = vlib_buffer_get_current (b0);
 921           ip6_frag_hdr_t *frag_hdr = NULL;
 922           ip6_ext_header_t *prev_hdr;
 923           if (ip6_ext_hdr (ip0->protocol))
 924             {
 925               ip6_ext_header_find_t (ip0, prev_hdr, frag_hdr,
 926                                      IP_PROTOCOL_IPV6_FRAGMENTATION);
 927             }
 928           if (!frag_hdr)
 929             {
 930               // this is a regular packet - no fragmentation
 931               next0 = IP6_REASSEMBLY_NEXT_INPUT;
 932               goto skip_reass;
 933             }
 934           if (0 == ip6_frag_hdr_offset (frag_hdr))
 935             {
 936               // first fragment - verify upper-layer is present
 937               if (!ip6_reass_verify_upper_layer_present (node, b0, frag_hdr))
 938                 {
 939                   next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
 940                   goto skip_reass;
 941                 }
 942             }
 943           if (!ip6_reass_verify_fragment_multiple_8 (vm, node, b0, frag_hdr)
 944               || !ip6_reass_verify_packet_size_lt_64k (vm, node, b0,
 945                                                        frag_hdr))
 946             {
 947               next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
 948               goto skip_reass;
 949             }
 950           vnet_buffer (b0)->ip.reass.ip6_frag_hdr_offset =
 951             (u8 *) frag_hdr - (u8 *) ip0;
 952
 953           ip6_reass_kv_t kv;
 954           u8 do_handoff = 0;
 955
 956           kv.k.as_u64[0] = ip0->src_address.as_u64[0];
 957           kv.k.as_u64[1] = ip0->src_address.as_u64[1];
 958           kv.k.as_u64[2] = ip0->dst_address.as_u64[0];
 959           kv.k.as_u64[3] = ip0->dst_address.as_u64[1];
 960           kv.k.as_u64[4] =
 961             ((u64) vec_elt (ip6_main.fib_index_by_sw_if_index,
 962                             vnet_buffer (b0)->sw_if_index[VLIB_RX])) << 32 |
 963             (u64) frag_hdr->identification;
 964           kv.k.as_u64[5] = ip0->protocol;
 965
 966           ip6_reass_t *reass =
 967             ip6_reass_find_or_create (vm, node, rm, rt, &kv, &icmp_bi,
 968                                       &do_handoff);
 969
 970           if (PREDICT_FALSE (do_handoff))
 971             {
 972               next0 = IP6_REASSEMBLY_NEXT_HANDOFF;
 973               if (is_feature)
 974                 vnet_buffer (b0)->ip.reass.owner_feature_thread_index =
 975                   kv.v.thread_index;
 976               else
 977                 vnet_buffer (b0)->ip.reass.owner_thread_index =
 978                   kv.v.thread_index;
 979             }
 980           else if (reass)
 981             {
 982               switch (ip6_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
 983                                         &error0, frag_hdr, is_feature))
 984                 {
 985                 case IP6_REASS_RC_OK:
 986                   /* nothing to do here */
 987                   break;
 988                 case IP6_REASS_RC_NO_BUF:
 989                   /* fallthrough */
 990                 case IP6_REASS_RC_INTERNAL_ERROR:
 991                   /* drop everything and start with a clean slate */
 992                   ip6_reass_drop_all (vm, rm, reass);
 993                   ip6_reass_free (rm, rt, reass);
 994                   goto next_packet;
 995                   break;
 996                 }
 997             }
 998           else
 999             {
1000               next0 = IP6_REASSEMBLY_NEXT_DROP;
1001               error0 = IP6_ERROR_REASS_LIMIT_REACHED;
1002             }
1003
1004           b0->error = node->errors[error0];
1005
1006           if (~0 != bi0)
1007             {
1008             skip_reass:
1009               to_next[0] = bi0;
1010               to_next += 1;
1011               n_left_to_next -= 1;
1012               if (is_feature && IP6_ERROR_NONE == error0)
1013                 {
1014                   b0 = vlib_get_buffer (vm, bi0);
1015                   vnet_feature_next (&next0, b0);
1016                 }
1017               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1018                                                n_left_to_next, bi0, next0);
1019             }
1020
1021           if (~0 != icmp_bi)
1022             {
1023               next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
1024               to_next[0] = icmp_bi;
1025               to_next += 1;
1026               n_left_to_next -= 1;
1027               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1028                                                n_left_to_next, icmp_bi,
1029                                                next0);
1030             }
1031         next_packet:
1032           from += 1;
1033           n_left_from -= 1;
1034         }
1035
1036       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1037     }
1038
1039   clib_spinlock_unlock (&rt->lock);
1040   return frame->n_vectors;
1041 }
1042
1043 static char *ip6_reassembly_error_strings[] = {
1044 #define _(sym, string) string,
1045   foreach_ip6_error
1046 #undef _
1047 };
1048
1049 static uword
1050 ip6_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
1051                 vlib_frame_t * frame)
1052 {
1053   return ip6_reassembly_inline (vm, node, frame, false /* is_feature */ );
1054 }
1055
1056 /* *INDENT-OFF* */
1057 VLIB_REGISTER_NODE (ip6_reass_node, static) = {
1058     .function = ip6_reassembly,
1059     .name = "ip6-reassembly",
1060     .vector_size = sizeof (u32),
1061     .format_trace = format_ip6_reass_trace,
1062     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1063     .error_strings = ip6_reassembly_error_strings,
1064     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1065     .next_nodes =
1066         {
1067                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1068                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1069                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1070                 [IP6_REASSEMBLY_NEXT_HANDOFF] = "ip6-reassembly-handoff",
1071         },
1072 };
1073 /* *INDENT-ON* */
1074
1075 VLIB_NODE_FUNCTION_MULTIARCH (ip6_reass_node, ip6_reassembly);
1076
1077 static uword
1078 ip6_reassembly_feature (vlib_main_t * vm,
1079                         vlib_node_runtime_t * node, vlib_frame_t * frame)
1080 {
1081   return ip6_reassembly_inline (vm, node, frame, true /* is_feature */ );
1082 }
1083
1084 /* *INDENT-OFF* */
1085 VLIB_REGISTER_NODE (ip6_reass_node_feature, static) = {
1086     .function = ip6_reassembly_feature,
1087     .name = "ip6-reassembly-feature",
1088     .vector_size = sizeof (u32),
1089     .format_trace = format_ip6_reass_trace,
1090     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1091     .error_strings = ip6_reassembly_error_strings,
1092     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1093     .next_nodes =
1094         {
1095                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1096                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1097                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1098                 [IP6_REASSEMBLY_NEXT_HANDOFF] = "ip6-reass-feature-hoff",
1099         },
1100 };
1101 /* *INDENT-ON* */
1102
1103 VLIB_NODE_FUNCTION_MULTIARCH (ip6_reass_node_feature, ip6_reassembly_feature);
1104
1105 /* *INDENT-OFF* */
1106 VNET_FEATURE_INIT (ip6_reassembly_feature, static) = {
1107     .arc_name = "ip6-unicast",
1108     .node_name = "ip6-reassembly-feature",
1109     .runs_before = VNET_FEATURES ("ip6-lookup"),
1110     .runs_after = 0,
1111 };
1112 /* *INDENT-ON* */
1113
1114 static u32
1115 ip6_reass_get_nbuckets ()
1116 {
1117   ip6_reass_main_t *rm = &ip6_reass_main;
1118   u32 nbuckets;
1119   u8 i;
1120
1121   nbuckets = (u32) (rm->max_reass_n / IP6_REASS_HT_LOAD_FACTOR);
1122
1123   for (i = 0; i < 31; i++)
1124     if ((1 << i) >= nbuckets)
1125       break;
1126   nbuckets = 1 << i;
1127
1128   return nbuckets;
1129 }
1130
1131 typedef enum
1132 {
1133   IP6_EVENT_CONFIG_CHANGED = 1,
1134 } ip6_reass_event_t;
1135
1136 typedef struct
1137 {
1138   int failure;
1139   clib_bihash_48_8_t *new_hash;
1140 } ip6_rehash_cb_ctx;
1141
1142 static void
1143 ip6_rehash_cb (clib_bihash_kv_48_8_t * kv, void *_ctx)
1144 {
1145   ip6_rehash_cb_ctx *ctx = _ctx;
1146   if (clib_bihash_add_del_48_8 (ctx->new_hash, kv, 1))
1147     {
1148       ctx->failure = 1;
1149     }
1150 }
1151
1152 static void
1153 ip6_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1154                       u32 expire_walk_interval_ms)
1155 {
1156   ip6_reass_main.timeout_ms = timeout_ms;
1157   ip6_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1158   ip6_reass_main.max_reass_n = max_reassemblies;
1159   ip6_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1160 }
1161
1162 vnet_api_error_t
1163 ip6_reass_set (u32 timeout_ms, u32 max_reassemblies,
1164                u32 expire_walk_interval_ms)
1165 {
1166   u32 old_nbuckets = ip6_reass_get_nbuckets ();
1167   ip6_reass_set_params (timeout_ms, max_reassemblies,
1168                         expire_walk_interval_ms);
1169   vlib_process_signal_event (ip6_reass_main.vlib_main,
1170                              ip6_reass_main.ip6_reass_expire_node_idx,
1171                              IP6_EVENT_CONFIG_CHANGED, 0);
1172   u32 new_nbuckets = ip6_reass_get_nbuckets ();
1173   if (ip6_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1174     {
1175       clib_bihash_48_8_t new_hash;
1176       clib_memset (&new_hash, 0, sizeof (new_hash));
1177       ip6_rehash_cb_ctx ctx;
1178       ctx.failure = 0;
1179       ctx.new_hash = &new_hash;
1180       clib_bihash_init_48_8 (&new_hash, "ip6-reass", new_nbuckets,
1181                              new_nbuckets * 1024);
1182       clib_bihash_foreach_key_value_pair_48_8 (&ip6_reass_main.hash,
1183                                                ip6_rehash_cb, &ctx);
1184       if (ctx.failure)
1185         {
1186           clib_bihash_free_48_8 (&new_hash);
1187           return -1;
1188         }
1189       else
1190         {
1191           clib_bihash_free_48_8 (&ip6_reass_main.hash);
1192           clib_memcpy_fast (&ip6_reass_main.hash, &new_hash,
1193                             sizeof (ip6_reass_main.hash));
1194         }
1195     }
1196   return 0;
1197 }
1198
1199 vnet_api_error_t
1200 ip6_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1201                u32 * expire_walk_interval_ms)
1202 {
1203   *timeout_ms = ip6_reass_main.timeout_ms;
1204   *max_reassemblies = ip6_reass_main.max_reass_n;
1205   *expire_walk_interval_ms = ip6_reass_main.expire_walk_interval_ms;
1206   return 0;
1207 }
1208
1209 static clib_error_t *
1210 ip6_reass_init_function (vlib_main_t * vm)
1211 {
1212   ip6_reass_main_t *rm = &ip6_reass_main;
1213   clib_error_t *error = 0;
1214   u32 nbuckets;
1215   vlib_node_t *node;
1216
1217   rm->vlib_main = vm;
1218   rm->vnet_main = vnet_get_main ();
1219
1220   vec_validate (rm->per_thread_data, vlib_num_workers ());
1221   ip6_reass_per_thread_t *rt;
1222   vec_foreach (rt, rm->per_thread_data)
1223   {
1224     clib_spinlock_init (&rt->lock);
1225     pool_alloc (rt->pool, rm->max_reass_n);
1226   }
1227
1228   node = vlib_get_node_by_name (vm, (u8 *) "ip6-reassembly-expire-walk");
1229   ASSERT (node);
1230   rm->ip6_reass_expire_node_idx = node->index;
1231
1232   ip6_reass_set_params (IP6_REASS_TIMEOUT_DEFAULT_MS,
1233                         IP6_REASS_MAX_REASSEMBLIES_DEFAULT,
1234                         IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1235
1236   nbuckets = ip6_reass_get_nbuckets ();
1237   clib_bihash_init_48_8 (&rm->hash, "ip6-reass", nbuckets, nbuckets * 1024);
1238
1239   node = vlib_get_node_by_name (vm, (u8 *) "ip6-drop");
1240   ASSERT (node);
1241   rm->ip6_drop_idx = node->index;
1242   node = vlib_get_node_by_name (vm, (u8 *) "ip6-icmp-error");
1243   ASSERT (node);
1244   rm->ip6_icmp_error_idx = node->index;
1245
1246   if ((error = vlib_call_init_function (vm, ip_main_init)))
1247     return error;
1248   ip6_register_protocol (IP_PROTOCOL_IPV6_FRAGMENTATION,
1249                          ip6_reass_node.index);
1250
1251   rm->fq_index = vlib_frame_queue_main_init (ip6_reass_node.index, 0);
1252   rm->fq_feature_index =
1253     vlib_frame_queue_main_init (ip6_reass_node_feature.index, 0);
1254
1255   return error;
1256 }
1257
1258 VLIB_INIT_FUNCTION (ip6_reass_init_function);
1259
1260 static uword
1261 ip6_reass_walk_expired (vlib_main_t * vm,
1262                         vlib_node_runtime_t * node, vlib_frame_t * f)
1263 {
1264   ip6_reass_main_t *rm = &ip6_reass_main;
1265   uword event_type, *event_data = 0;
1266
1267   while (true)
1268     {
1269       vlib_process_wait_for_event_or_clock (vm,
1270                                             (f64) rm->expire_walk_interval_ms
1271                                             / (f64) MSEC_PER_SEC);
1272       event_type = vlib_process_get_events (vm, &event_data);
1273
1274       switch (event_type)
1275         {
1276         case ~0:                /* no events => timeout */
1277           /* nothing to do here */
1278           break;
1279         case IP6_EVENT_CONFIG_CHANGED:
1280           break;
1281         default:
1282           clib_warning ("BUG: event type 0x%wx", event_type);
1283           break;
1284         }
1285       f64 now = vlib_time_now (vm);
1286
1287       ip6_reass_t *reass;
1288       int *pool_indexes_to_free = NULL;
1289
1290       uword thread_index = 0;
1291       int index;
1292       const uword nthreads = vlib_num_workers () + 1;
1293       u32 *vec_icmp_bi = NULL;
1294       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1295         {
1296           ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1297           clib_spinlock_lock (&rt->lock);
1298
1299           vec_reset_length (pool_indexes_to_free);
1300           /* *INDENT-OFF* */
1301           pool_foreach_index (index, rt->pool, ({
1302                                 reass = pool_elt_at_index (rt->pool, index);
1303                                 if (now > reass->last_heard + rm->timeout)
1304                                   {
1305                                     vec_add1 (pool_indexes_to_free, index);
1306                                   }
1307                               }));
1308           /* *INDENT-ON* */
1309           int *i;
1310           /* *INDENT-OFF* */
1311           vec_foreach (i, pool_indexes_to_free)
1312           {
1313             ip6_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1314             u32 icmp_bi = ~0;
1315             vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
1316             if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1317               {
1318                 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1319                                         b->trace_index))
1320                   {
1321                     /* the trace is gone, don't trace this buffer anymore */
1322                     b->flags &= ~VLIB_BUFFER_IS_TRACED;
1323                   }
1324               }
1325             ip6_reass_on_timeout (vm, node, rm, reass, &icmp_bi);
1326             if (~0 != icmp_bi)
1327               {
1328                 vec_add1 (vec_icmp_bi, icmp_bi);
1329               }
1330             ip6_reass_free (rm, rt, reass);
1331           }
1332           /* *INDENT-ON* */
1333
1334           clib_spinlock_unlock (&rt->lock);
1335         }
1336
1337       while (vec_len (vec_icmp_bi) > 0)
1338         {
1339           vlib_frame_t *f =
1340             vlib_get_frame_to_node (vm, rm->ip6_icmp_error_idx);
1341           u32 *to_next = vlib_frame_vector_args (f);
1342           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1343           int trace_frame = 0;
1344           while (vec_len (vec_icmp_bi) > 0 && n_left_to_next > 0)
1345             {
1346               u32 bi = vec_pop (vec_icmp_bi);
1347               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1348               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1349                 {
1350                   if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1351                                           b->trace_index))
1352                     {
1353                       /* the trace is gone, don't trace this buffer anymore */
1354                       b->flags &= ~VLIB_BUFFER_IS_TRACED;
1355                     }
1356                   else
1357                     {
1358                       trace_frame = 1;
1359                     }
1360                 }
1361               b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
1362               to_next[0] = bi;
1363               ++f->n_vectors;
1364               to_next += 1;
1365               n_left_to_next -= 1;
1366             }
1367           f->frame_flags |= (trace_frame * VLIB_FRAME_TRACE);
1368           vlib_put_frame_to_node (vm, rm->ip6_icmp_error_idx, f);
1369         }
1370
1371       vec_free (pool_indexes_to_free);
1372       vec_free (vec_icmp_bi);
1373       if (event_data)
1374         {
1375           _vec_len (event_data) = 0;
1376         }
1377     }
1378
1379   return 0;
1380 }
1381
1382 static vlib_node_registration_t ip6_reass_expire_node;
1383
1384 /* *INDENT-OFF* */
1385 VLIB_REGISTER_NODE (ip6_reass_expire_node, static) = {
1386     .function = ip6_reass_walk_expired,
1387     .format_trace = format_ip6_reass_trace,
1388     .type = VLIB_NODE_TYPE_PROCESS,
1389     .name = "ip6-reassembly-expire-walk",
1390
1391     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1392     .error_strings = ip6_reassembly_error_strings,
1393
1394 };
1395 /* *INDENT-ON* */
1396
1397 static u8 *
1398 format_ip6_reass_key (u8 * s, va_list * args)
1399 {
1400   ip6_reass_key_t *key = va_arg (*args, ip6_reass_key_t *);
1401   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1402               key->xx_id, format_ip6_address, &key->src, format_ip6_address,
1403               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1404   return s;
1405 }
1406
1407 static u8 *
1408 format_ip6_reass (u8 * s, va_list * args)
1409 {
1410   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1411   ip6_reass_t *reass = va_arg (*args, ip6_reass_t *);
1412
1413   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1414               "last_packet_octet: %u, trace_op_counter: %u\n",
1415               reass->id, format_ip6_reass_key, &reass->key, reass->first_bi,
1416               reass->data_len, reass->last_packet_octet,
1417               reass->trace_op_counter);
1418   u32 bi = reass->first_bi;
1419   u32 counter = 0;
1420   while (~0 != bi)
1421     {
1422       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1423       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1424       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1425                   "fragment[%u, %u]\n",
1426                   counter, vnb->ip.reass.range_first,
1427                   vnb->ip.reass.range_last, bi,
1428                   ip6_reass_buffer_get_data_offset (b),
1429                   ip6_reass_buffer_get_data_len (b),
1430                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1431       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1432         {
1433           bi = b->next_buffer;
1434         }
1435       else
1436         {
1437           bi = ~0;
1438         }
1439     }
1440   return s;
1441 }
1442
1443 static clib_error_t *
1444 show_ip6_reass (vlib_main_t * vm, unformat_input_t * input,
1445                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1446 {
1447   ip6_reass_main_t *rm = &ip6_reass_main;
1448
1449   vlib_cli_output (vm, "---------------------");
1450   vlib_cli_output (vm, "IP6 reassembly status");
1451   vlib_cli_output (vm, "---------------------");
1452   bool details = false;
1453   if (unformat (input, "details"))
1454     {
1455       details = true;
1456     }
1457
1458   u32 sum_reass_n = 0;
1459   u64 sum_buffers_n = 0;
1460   ip6_reass_t *reass;
1461   uword thread_index;
1462   const uword nthreads = vlib_num_workers () + 1;
1463   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1464     {
1465       ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1466       clib_spinlock_lock (&rt->lock);
1467       if (details)
1468         {
1469           /* *INDENT-OFF* */
1470           pool_foreach (reass, rt->pool, {
1471             vlib_cli_output (vm, "%U", format_ip6_reass, vm, reass);
1472           });
1473           /* *INDENT-ON* */
1474         }
1475       sum_reass_n += rt->reass_n;
1476       clib_spinlock_unlock (&rt->lock);
1477     }
1478   vlib_cli_output (vm, "---------------------");
1479   vlib_cli_output (vm, "Current IP6 reassemblies count: %lu\n",
1480                    (long unsigned) sum_reass_n);
1481   vlib_cli_output (vm, "Maximum configured concurrent IP6 reassemblies per "
1482                    "worker-thread: %lu\n", (long unsigned) rm->max_reass_n);
1483   vlib_cli_output (vm, "Buffers in use: %lu\n",
1484                    (long unsigned) sum_buffers_n);
1485   return 0;
1486 }
1487
1488 /* *INDENT-OFF* */
1489 VLIB_CLI_COMMAND (show_ip6_reassembly_cmd, static) = {
1490     .path = "show ip6-reassembly",
1491     .short_help = "show ip6-reassembly [details]",
1492     .function = show_ip6_reass,
1493 };
1494 /* *INDENT-ON* */
1495
1496 vnet_api_error_t
1497 ip6_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1498 {
1499   return vnet_feature_enable_disable ("ip6-unicast", "ip6-reassembly-feature",
1500                                       sw_if_index, enable_disable, 0, 0);
1501 }
1502
1503 #define foreach_ip6_reassembly_handoff_error                       \
1504 _(CONGESTION_DROP, "congestion drop")
1505
1506
1507 typedef enum
1508 {
1509 #define _(sym,str) IP6_REASSEMBLY_HANDOFF_ERROR_##sym,
1510   foreach_ip6_reassembly_handoff_error
1511 #undef _
1512     IP6_REASSEMBLY_HANDOFF_N_ERROR,
1513 } ip6_reassembly_handoff_error_t;
1514
1515 static char *ip6_reassembly_handoff_error_strings[] = {
1516 #define _(sym,string) string,
1517   foreach_ip6_reassembly_handoff_error
1518 #undef _
1519 };
1520
1521 typedef struct
1522 {
1523   u32 next_worker_index;
1524 } ip6_reassembly_handoff_trace_t;
1525
1526 static u8 *
1527 format_ip6_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   ip6_reassembly_handoff_trace_t *t =
1532     va_arg (*args, ip6_reassembly_handoff_trace_t *);
1533
1534   s =
1535     format (s, "ip6-reassembly-handoff: next-worker %d",
1536             t->next_worker_index);
1537
1538   return s;
1539 }
1540
1541 always_inline uword
1542 ip6_reassembly_handoff_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1543                                vlib_frame_t * frame, bool is_feature)
1544 {
1545   ip6_reass_main_t *rm = &ip6_reass_main;
1546
1547   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
1548   u32 n_enq, n_left_from, *from;
1549   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
1550   u32 fq_index;
1551
1552   from = vlib_frame_vector_args (frame);
1553   n_left_from = frame->n_vectors;
1554   vlib_get_buffers (vm, from, bufs, n_left_from);
1555
1556   b = bufs;
1557   ti = thread_indices;
1558
1559   fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index;
1560
1561   while (n_left_from > 0)
1562     {
1563       ti[0] =
1564         (is_feature) ? vnet_buffer (b[0])->ip.
1565         reass.owner_feature_thread_index : vnet_buffer (b[0])->ip.
1566         reass.owner_thread_index;
1567
1568       if (PREDICT_FALSE
1569           ((node->flags & VLIB_NODE_FLAG_TRACE)
1570            && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
1571         {
1572           ip6_reassembly_handoff_trace_t *t =
1573             vlib_add_trace (vm, node, b[0], sizeof (*t));
1574           t->next_worker_index = ti[0];
1575         }
1576
1577       n_left_from -= 1;
1578       ti += 1;
1579       b += 1;
1580     }
1581   n_enq =
1582     vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
1583                                    frame->n_vectors, 1);
1584
1585   if (n_enq < frame->n_vectors)
1586     vlib_node_increment_counter (vm, node->node_index,
1587                                  IP6_REASSEMBLY_HANDOFF_ERROR_CONGESTION_DROP,
1588                                  frame->n_vectors - n_enq);
1589   return frame->n_vectors;
1590 }
1591
1592 VLIB_NODE_FN (ip6_reassembly_handoff_node) (vlib_main_t * vm,
1593                                             vlib_node_runtime_t * node,
1594                                             vlib_frame_t * frame)
1595 {
1596   return ip6_reassembly_handoff_inline (vm, node, frame,
1597                                         false /* is_feature */ );
1598 }
1599
1600 /* *INDENT-OFF* */
1601 VLIB_REGISTER_NODE (ip6_reassembly_handoff_node) = {
1602   .name = "ip6-reassembly-handoff",
1603   .vector_size = sizeof (u32),
1604   .n_errors = ARRAY_LEN(ip6_reassembly_handoff_error_strings),
1605   .error_strings = ip6_reassembly_handoff_error_strings,
1606   .format_trace = format_ip6_reassembly_handoff_trace,
1607
1608   .n_next_nodes = 1,
1609
1610   .next_nodes = {
1611     [0] = "error-drop",
1612   },
1613 };
1614
1615
1616 VLIB_NODE_FN (ip6_reassembly_feature_handoff_node) (vlib_main_t * vm,
1617                                vlib_node_runtime_t * node, vlib_frame_t * frame)
1618 {
1619   return ip6_reassembly_handoff_inline (vm, node, frame, true /* is_feature */ );
1620 }
1621
1622
1623 /* *INDENT-OFF* */
1624 VLIB_REGISTER_NODE (ip6_reassembly_feature_handoff_node) = {
1625   .name = "ip6-reass-feature-hoff",
1626   .vector_size = sizeof (u32),
1627   .n_errors = ARRAY_LEN(ip6_reassembly_handoff_error_strings),
1628   .error_strings = ip6_reassembly_handoff_error_strings,
1629   .format_trace = format_ip6_reassembly_handoff_trace,
1630
1631   .n_next_nodes = 1,
1632
1633   .next_nodes = {
1634     [0] = "error-drop",
1635   },
1636 };
1637 /* *INDENT-ON* */
1638
1639 /*
1640  * fd.io coding-style-patch-verification: ON
1641  *
1642  * Local Variables:
1643  * eval: (c-set-style "gnu")
1644  * End:
1645  */