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_MAX_REASSEMBLY_LENGTH_DEFAULT 3
  34 #define IP6_REASS_HT_LOAD_FACTOR (0.75)
  35
  36 typedef enum
  37 {
  38   IP6_REASS_RC_OK,
  39   IP6_REASS_RC_INTERNAL_ERROR,
  40   IP6_REASS_RC_TOO_MANY_FRAGMENTS,
  41   IP6_REASS_RC_NO_BUF,
  42 } ip6_reass_rc_t;
  43
  44 typedef struct
  45 {
  46   union
  47   {
  48     struct
  49     {
  50       ip6_address_t src;
  51       ip6_address_t dst;
  52       u32 xx_id;
  53       u32 frag_id;
  54       u8 unused[7];
  55       u8 proto;
  56     };
  57     u64 as_u64[6];
  58   };
  59 } ip6_reass_key_t;
  60
  61 typedef union
  62 {
  63   struct
  64   {
  65     u32 reass_index;
  66     u32 thread_index;
  67   };
  68   u64 as_u64;
  69 } ip6_reass_val_t;
  70
  71 typedef union
  72 {
  73   struct
  74   {
  75     ip6_reass_key_t k;
  76     ip6_reass_val_t v;
  77   };
  78   clib_bihash_kv_48_8_t kv;
  79 } ip6_reass_kv_t;
  80
  81
  82 always_inline u32
  83 ip6_reass_buffer_get_data_offset (vlib_buffer_t * b)
  84 {
  85   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  86   return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
  87 }
  88
  89 always_inline u16
  90 ip6_reass_buffer_get_data_len (vlib_buffer_t * b)
  91 {
  92   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  93   return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
  94     (vnb->ip.reass.fragment_first + ip6_reass_buffer_get_data_offset (b)) + 1;
  95 }
  96
  97 typedef struct
  98 {
  99   // hash table key
 100   ip6_reass_key_t key;
 101   // time when last packet was received
 102   f64 last_heard;
 103   // internal id of this reassembly
 104   u64 id;
 105   // buffer index of first buffer in this reassembly context
 106   u32 first_bi;
 107   // last octet of packet, ~0 until fragment without more_fragments arrives
 108   u32 last_packet_octet;
 109   // length of data collected so far
 110   u32 data_len;
 111   // trace operation counter
 112   u32 trace_op_counter;
 113   // next index - used by custom apps (~0 if not set)
 114   u32 next_index;
 115   // error next index - used by custom apps (~0 if not set)
 116   u32 error_next_index;
 117   // minimum fragment length for this reassembly - used to estimate MTU
 118   u16 min_fragment_length;
 119   // number of fragments for this reassembly
 120   u32 fragments_n;
 121 } ip6_reass_t;
 122
 123 typedef struct
 124 {
 125   ip6_reass_t *pool;
 126   u32 reass_n;
 127   u32 id_counter;
 128   clib_spinlock_t lock;
 129 } ip6_reass_per_thread_t;
 130
 131 typedef struct
 132 {
 133   // IPv6 config
 134   u32 timeout_ms;
 135   f64 timeout;
 136   u32 expire_walk_interval_ms;
 137   // maximum number of fragments in one reassembly
 138   u32 max_reass_len;
 139   // maximum number of reassemblies
 140   u32 max_reass_n;
 141
 142   // IPv6 runtime
 143   clib_bihash_48_8_t hash;
 144
 145   // per-thread data
 146   ip6_reass_per_thread_t *per_thread_data;
 147
 148   // convenience
 149   vlib_main_t *vlib_main;
 150   vnet_main_t *vnet_main;
 151
 152   // node index of ip6-drop node
 153   u32 ip6_drop_idx;
 154   u32 ip6_icmp_error_idx;
 155   u32 ip6_reass_expire_node_idx;
 156
 157   /** Worker handoff */
 158   u32 fq_index;
 159   u32 fq_feature_index;
 160
 161 } ip6_reass_main_t;
 162
 163 extern ip6_reass_main_t ip6_reass_main;
 164
 165 #ifndef CLIB_MARCH_VARIANT
 166 ip6_reass_main_t ip6_reass_main;
 167 #endif /* CLIB_MARCH_VARIANT */
 168
 169 typedef enum
 170 {
 171   IP6_REASSEMBLY_NEXT_INPUT,
 172   IP6_REASSEMBLY_NEXT_DROP,
 173   IP6_REASSEMBLY_NEXT_ICMP_ERROR,
 174   IP6_REASSEMBLY_NEXT_HANDOFF,
 175   IP6_REASSEMBLY_N_NEXT,
 176 } ip6_reass_next_t;
 177
 178 typedef enum
 179 {
 180   RANGE_NEW,
 181   RANGE_OVERLAP,
 182   ICMP_ERROR_RT_EXCEEDED,
 183   ICMP_ERROR_FL_TOO_BIG,
 184   ICMP_ERROR_FL_NOT_MULT_8,
 185   FINALIZE,
 186 } ip6_reass_trace_operation_e;
 187
 188 typedef struct
 189 {
 190   u16 range_first;
 191   u16 range_last;
 192   u32 range_bi;
 193   i32 data_offset;
 194   u32 data_len;
 195   u32 first_bi;
 196 } ip6_reass_range_trace_t;
 197
 198 typedef struct
 199 {
 200   ip6_reass_trace_operation_e action;
 201   u32 reass_id;
 202   ip6_reass_range_trace_t trace_range;
 203   u32 size_diff;
 204   u32 op_id;
 205   u32 fragment_first;
 206   u32 fragment_last;
 207   u32 total_data_len;
 208 } ip6_reass_trace_t;
 209
 210 static void
 211 ip6_reass_trace_details (vlib_main_t * vm, u32 bi,
 212                          ip6_reass_range_trace_t * trace)
 213 {
 214   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 215   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 216   trace->range_first = vnb->ip.reass.range_first;
 217   trace->range_last = vnb->ip.reass.range_last;
 218   trace->data_offset = ip6_reass_buffer_get_data_offset (b);
 219   trace->data_len = ip6_reass_buffer_get_data_len (b);
 220   trace->range_bi = bi;
 221 }
 222
 223 static u8 *
 224 format_ip6_reass_range_trace (u8 * s, va_list * args)
 225 {
 226   ip6_reass_range_trace_t *trace = va_arg (*args, ip6_reass_range_trace_t *);
 227   s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
 228               trace->range_last, trace->data_offset, trace->data_len,
 229               trace->range_bi);
 230   return s;
 231 }
 232
 233 static u8 *
 234 format_ip6_reass_trace (u8 * s, va_list * args)
 235 {
 236   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 237   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 238   ip6_reass_trace_t *t = va_arg (*args, ip6_reass_trace_t *);
 239   s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
 240   u32 indent = format_get_indent (s);
 241   s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
 242               t->trace_range.first_bi, t->total_data_len, t->fragment_first,
 243               t->fragment_last);
 244   switch (t->action)
 245     {
 246     case RANGE_NEW:
 247       s = format (s, "\n%Unew %U", format_white_space, indent,
 248                   format_ip6_reass_range_trace, &t->trace_range);
 249       break;
 250     case RANGE_OVERLAP:
 251       s = format (s, "\n%Uoverlap %U", format_white_space, indent,
 252                   format_ip6_reass_range_trace, &t->trace_range);
 253       break;
 254     case ICMP_ERROR_FL_TOO_BIG:
 255       s = format (s, "\n%Uicmp-error - frag_len > 65535 %U",
 256                   format_white_space, indent, format_ip6_reass_range_trace,
 257                   &t->trace_range);
 258       break;
 259     case ICMP_ERROR_FL_NOT_MULT_8:
 260       s = format (s, "\n%Uicmp-error - frag_len mod 8 != 0 %U",
 261                   format_white_space, indent, format_ip6_reass_range_trace,
 262                   &t->trace_range);
 263       break;
 264     case ICMP_ERROR_RT_EXCEEDED:
 265       s = format (s, "\n%Uicmp-error - reassembly time exceeded",
 266                   format_white_space, indent);
 267       break;
 268     case FINALIZE:
 269       s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
 270       break;
 271     }
 272   return s;
 273 }
 274
 275 static void
 276 ip6_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 277                      ip6_reass_main_t * rm, ip6_reass_t * reass,
 278                      u32 bi, ip6_reass_trace_operation_e action,
 279                      u32 size_diff)
 280 {
 281   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 282   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 283   if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
 284     {
 285       // this buffer's trace is gone
 286       b->flags &= ~VLIB_BUFFER_IS_TRACED;
 287       return;
 288     }
 289   ip6_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 290   t->reass_id = reass->id;
 291   t->action = action;
 292   ip6_reass_trace_details (vm, bi, &t->trace_range);
 293   t->size_diff = size_diff;
 294   t->op_id = reass->trace_op_counter;
 295   ++reass->trace_op_counter;
 296   t->fragment_first = vnb->ip.reass.fragment_first;
 297   t->fragment_last = vnb->ip.reass.fragment_last;
 298   t->trace_range.first_bi = reass->first_bi;
 299   t->total_data_len = reass->data_len;
 300 #if 0
 301   static u8 *s = NULL;
 302   s = format (s, "%U", format_ip6_reass_trace, NULL, NULL, t);
 303   printf ("%.*s\n", vec_len (s), s);
 304   fflush (stdout);
 305   vec_reset_length (s);
 306 #endif
 307 }
 308
 309 always_inline void
 310 ip6_reass_free (ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 311                 ip6_reass_t * reass)
 312 {
 313   clib_bihash_kv_48_8_t kv;
 314   kv.key[0] = reass->key.as_u64[0];
 315   kv.key[1] = reass->key.as_u64[1];
 316   kv.key[2] = reass->key.as_u64[2];
 317   kv.key[3] = reass->key.as_u64[3];
 318   kv.key[4] = reass->key.as_u64[4];
 319   kv.key[5] = reass->key.as_u64[5];
 320   clib_bihash_add_del_48_8 (&rm->hash, &kv, 0);
 321   pool_put (rt->pool, reass);
 322   --rt->reass_n;
 323 }
 324
 325 always_inline void
 326 ip6_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
 327                     ip6_reass_main_t * rm, ip6_reass_t * reass)
 328 {
 329   u32 range_bi = reass->first_bi;
 330   vlib_buffer_t *range_b;
 331   vnet_buffer_opaque_t *range_vnb;
 332   u32 *to_free = NULL;
 333   while (~0 != range_bi)
 334     {
 335       range_b = vlib_get_buffer (vm, range_bi);
 336       range_vnb = vnet_buffer (range_b);
 337       u32 bi = range_bi;
 338       while (~0 != bi)
 339         {
 340           vec_add1 (to_free, bi);
 341           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 342           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 343             {
 344               bi = b->next_buffer;
 345               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 346             }
 347           else
 348             {
 349               bi = ~0;
 350             }
 351         }
 352       range_bi = range_vnb->ip.reass.next_range_bi;
 353     }
 354   /* send to next_error_index */
 355   if (~0 != reass->error_next_index)
 356     {
 357       u32 n_left_to_next, *to_next, next_index;
 358
 359       next_index = reass->error_next_index;
 360       u32 bi = ~0;
 361
 362       while (vec_len (to_free) > 0)
 363         {
 364           vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 365
 366           while (vec_len (to_free) > 0 && n_left_to_next > 0)
 367             {
 368               bi = vec_pop (to_free);
 369
 370               if (~0 != bi)
 371                 {
 372                   to_next[0] = bi;
 373                   to_next += 1;
 374                   n_left_to_next -= 1;
 375                   vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 376                                                    to_next, n_left_to_next,
 377                                                    bi, next_index);
 378                 }
 379             }
 380           vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 381         }
 382     }
 383   else
 384     {
 385       vlib_buffer_free (vm, to_free, vec_len (to_free));
 386     }
 387   vec_free (to_free);
 388 }
 389
 390 always_inline void
 391 ip6_reass_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * node,
 392                       ip6_reass_main_t * rm, ip6_reass_t * reass,
 393                       u32 * icmp_bi)
 394 {
 395   if (~0 == reass->first_bi)
 396     {
 397       return;
 398     }
 399   if (~0 == reass->next_index)  // custom apps don't want icmp
 400     {
 401       vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
 402       if (0 == vnet_buffer (b)->ip.reass.fragment_first)
 403         {
 404           *icmp_bi = reass->first_bi;
 405           if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
 406             {
 407               ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi,
 408                                    ICMP_ERROR_RT_EXCEEDED, 0);
 409             }
 410           // fragment with offset zero received - send icmp message back
 411           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 412             {
 413               // separate first buffer from chain and steer it towards icmp node
 414               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 415               reass->first_bi = b->next_buffer;
 416             }
 417           else
 418             {
 419               reass->first_bi = vnet_buffer (b)->ip.reass.next_range_bi;
 420             }
 421           icmp6_error_set_vnet_buffer (b, ICMP6_time_exceeded,
 422                                        ICMP6_time_exceeded_fragment_reassembly_time_exceeded,
 423                                        0);
 424         }
 425     }
 426   ip6_reass_drop_all (vm, node, rm, reass);
 427 }
 428
 429 always_inline ip6_reass_t *
 430 ip6_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 431                           ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 432                           ip6_reass_kv_t * kv, u32 * icmp_bi, u8 * do_handoff)
 433 {
 434   ip6_reass_t *reass = NULL;
 435   f64 now = vlib_time_now (rm->vlib_main);
 436
 437   if (!clib_bihash_search_48_8
 438       (&rm->hash, (clib_bihash_kv_48_8_t *) kv, (clib_bihash_kv_48_8_t *) kv))
 439     {
 440       if (vm->thread_index != kv->v.thread_index)
 441         {
 442           *do_handoff = 1;
 443           return NULL;
 444         }
 445       reass = pool_elt_at_index (rt->pool, kv->v.reass_index);
 446
 447       if (now > reass->last_heard + rm->timeout)
 448         {
 449           ip6_reass_on_timeout (vm, node, rm, reass, icmp_bi);
 450           ip6_reass_free (rm, rt, reass);
 451           reass = NULL;
 452         }
 453     }
 454
 455   if (reass)
 456     {
 457       reass->last_heard = now;
 458       return reass;
 459     }
 460
 461   if (rt->reass_n >= rm->max_reass_n)
 462     {
 463       reass = NULL;
 464       return reass;
 465     }
 466   else
 467     {
 468       pool_get (rt->pool, reass);
 469       clib_memset (reass, 0, sizeof (*reass));
 470       reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter;
 471       ++rt->id_counter;
 472       reass->first_bi = ~0;
 473       reass->last_packet_octet = ~0;
 474       reass->data_len = 0;
 475       reass->next_index = ~0;
 476       reass->error_next_index = ~0;
 477       ++rt->reass_n;
 478     }
 479
 480   reass->key.as_u64[0] = ((clib_bihash_kv_48_8_t *) kv)->key[0];
 481   reass->key.as_u64[1] = ((clib_bihash_kv_48_8_t *) kv)->key[1];
 482   reass->key.as_u64[2] = ((clib_bihash_kv_48_8_t *) kv)->key[2];
 483   reass->key.as_u64[3] = ((clib_bihash_kv_48_8_t *) kv)->key[3];
 484   reass->key.as_u64[4] = ((clib_bihash_kv_48_8_t *) kv)->key[4];
 485   reass->key.as_u64[5] = ((clib_bihash_kv_48_8_t *) kv)->key[5];
 486   kv->v.reass_index = (reass - rt->pool);
 487   kv->v.thread_index = vm->thread_index;
 488   reass->last_heard = now;
 489
 490   if (clib_bihash_add_del_48_8 (&rm->hash, (clib_bihash_kv_48_8_t *) kv, 1))
 491     {
 492       ip6_reass_free (rm, rt, reass);
 493       reass = NULL;
 494     }
 495
 496   return reass;
 497 }
 498
 499 always_inline ip6_reass_rc_t
 500 ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 501                     ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 502                     ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 503                     bool is_custom_app)
 504 {
 505   *bi0 = reass->first_bi;
 506   *error0 = IP6_ERROR_NONE;
 507   ip6_frag_hdr_t *frag_hdr;
 508   vlib_buffer_t *last_b = NULL;
 509   u32 sub_chain_bi = reass->first_bi;
 510   u32 total_length = 0;
 511   u32 buf_cnt = 0;
 512   u32 dropped_cnt = 0;
 513   u32 *vec_drop_compress = NULL;
 514   ip6_reass_rc_t rv = IP6_REASS_RC_OK;
 515   do
 516     {
 517       u32 tmp_bi = sub_chain_bi;
 518       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 519       vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
 520       if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 521           !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 522         {
 523           rv = IP6_REASS_RC_INTERNAL_ERROR;
 524           goto free_buffers_and_return;
 525         }
 526
 527       u32 data_len = ip6_reass_buffer_get_data_len (tmp);
 528       u32 trim_front = vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 529         sizeof (*frag_hdr) + ip6_reass_buffer_get_data_offset (tmp);
 530       u32 trim_end =
 531         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 532       if (tmp_bi == reass->first_bi)
 533         {
 534           /* first buffer - keep ip6 header */
 535           if (0 != ip6_reass_buffer_get_data_offset (tmp))
 536             {
 537               rv = IP6_REASS_RC_INTERNAL_ERROR;
 538               goto free_buffers_and_return;
 539             }
 540           trim_front = 0;
 541           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 542             (vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 543              sizeof (*frag_hdr));
 544           if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
 545             {
 546               rv = IP6_REASS_RC_INTERNAL_ERROR;
 547               goto free_buffers_and_return;
 548             }
 549         }
 550       u32 keep_data =
 551         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 552       while (1)
 553         {
 554           ++buf_cnt;
 555           if (trim_front)
 556             {
 557               if (trim_front > tmp->current_length)
 558                 {
 559                   /* drop whole buffer */
 560                   vec_add1 (vec_drop_compress, tmp_bi);
 561                   trim_front -= tmp->current_length;
 562                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 563                     {
 564                       rv = IP6_REASS_RC_INTERNAL_ERROR;
 565                       goto free_buffers_and_return;
 566                     }
 567                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 568                   tmp_bi = tmp->next_buffer;
 569                   tmp = vlib_get_buffer (vm, tmp_bi);
 570                   continue;
 571                 }
 572               else
 573                 {
 574                   vlib_buffer_advance (tmp, trim_front);
 575                   trim_front = 0;
 576                 }
 577             }
 578           if (keep_data)
 579             {
 580               if (last_b)
 581                 {
 582                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 583                   last_b->next_buffer = tmp_bi;
 584                 }
 585               last_b = tmp;
 586               if (keep_data <= tmp->current_length)
 587                 {
 588                   tmp->current_length = keep_data;
 589                   keep_data = 0;
 590                 }
 591               else
 592                 {
 593                   keep_data -= tmp->current_length;
 594                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 595                     {
 596                       rv = IP6_REASS_RC_INTERNAL_ERROR;
 597                       goto free_buffers_and_return;
 598                     }
 599                 }
 600               total_length += tmp->current_length;
 601             }
 602           else
 603             {
 604               vec_add1 (vec_drop_compress, tmp_bi);
 605               if (reass->first_bi == tmp_bi)
 606                 {
 607                   rv = IP6_REASS_RC_INTERNAL_ERROR;
 608                   goto free_buffers_and_return;
 609                 }
 610               ++dropped_cnt;
 611             }
 612           if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 613             {
 614               tmp_bi = tmp->next_buffer;
 615               tmp = vlib_get_buffer (vm, tmp->next_buffer);
 616             }
 617           else
 618             {
 619               break;
 620             }
 621         }
 622       sub_chain_bi =
 623         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 624         reass.next_range_bi;
 625     }
 626   while (~0 != sub_chain_bi);
 627
 628   if (!last_b)
 629     {
 630       rv = IP6_REASS_RC_INTERNAL_ERROR;
 631       goto free_buffers_and_return;
 632     }
 633   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 634   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 635   if (total_length < first_b->current_length)
 636     {
 637       rv = IP6_REASS_RC_INTERNAL_ERROR;
 638       goto free_buffers_and_return;
 639     }
 640   total_length -= first_b->current_length;
 641   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 642   first_b->total_length_not_including_first_buffer = total_length;
 643   // drop fragment header
 644   vnet_buffer_opaque_t *first_b_vnb = vnet_buffer (first_b);
 645   ip6_header_t *ip = vlib_buffer_get_current (first_b);
 646   u16 ip6_frag_hdr_offset = first_b_vnb->ip.reass.ip6_frag_hdr_offset;
 647   ip6_ext_header_t *prev_hdr;
 648   ip6_ext_header_find_t (ip, prev_hdr, frag_hdr,
 649                          IP_PROTOCOL_IPV6_FRAGMENTATION);
 650   if (prev_hdr)
 651     {
 652       prev_hdr->next_hdr = frag_hdr->next_hdr;
 653     }
 654   else
 655     {
 656       ip->protocol = frag_hdr->next_hdr;
 657     }
 658   if (!((u8 *) frag_hdr - (u8 *) ip == ip6_frag_hdr_offset))
 659     {
 660       rv = IP6_REASS_RC_INTERNAL_ERROR;
 661       goto free_buffers_and_return;
 662     }
 663   memmove (frag_hdr, (u8 *) frag_hdr + sizeof (*frag_hdr),
 664            first_b->current_length - ip6_frag_hdr_offset -
 665            sizeof (ip6_frag_hdr_t));
 666   first_b->current_length -= sizeof (*frag_hdr);
 667   ip->payload_length =
 668     clib_host_to_net_u16 (total_length + first_b->current_length -
 669                           sizeof (*ip));
 670   if (!vlib_buffer_chain_linearize (vm, first_b))
 671     {
 672       rv = IP6_REASS_RC_NO_BUF;
 673       goto free_buffers_and_return;
 674     }
 675   first_b->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
 676   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 677     {
 678       ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 679 #if 0
 680       // following code does a hexdump of packet fragments to stdout ...
 681       do
 682         {
 683           u32 bi = reass->first_bi;
 684           u8 *s = NULL;
 685           while (~0 != bi)
 686             {
 687               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 688               s = format (s, "%u: %U\n", bi, format_hexdump,
 689                           vlib_buffer_get_current (b), b->current_length);
 690               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 691                 {
 692                   bi = b->next_buffer;
 693                 }
 694               else
 695                 {
 696                   break;
 697                 }
 698             }
 699           printf ("%.*s\n", vec_len (s), s);
 700           fflush (stdout);
 701           vec_free (s);
 702         }
 703       while (0);
 704 #endif
 705     }
 706   if (!is_custom_app)
 707     {
 708       *next0 = IP6_REASSEMBLY_NEXT_INPUT;
 709     }
 710   else
 711     {
 712       *next0 = reass->next_index;
 713     }
 714   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 715   ip6_reass_free (rm, rt, reass);
 716   reass = NULL;
 717 free_buffers_and_return:
 718   vlib_buffer_free (vm, vec_drop_compress, vec_len (vec_drop_compress));
 719   vec_free (vec_drop_compress);
 720   return rv;
 721 }
 722
 723 always_inline void
 724 ip6_reass_insert_range_in_chain (vlib_main_t * vm, ip6_reass_main_t * rm,
 725                                  ip6_reass_per_thread_t * rt,
 726                                  ip6_reass_t * reass, u32 prev_range_bi,
 727                                  u32 new_next_bi)
 728 {
 729
 730   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 731   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 732   if (~0 != prev_range_bi)
 733     {
 734       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 735       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 736       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 737       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 738     }
 739   else
 740     {
 741       if (~0 != reass->first_bi)
 742         {
 743           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 744         }
 745       reass->first_bi = new_next_bi;
 746     }
 747   reass->data_len += ip6_reass_buffer_get_data_len (new_next_b);
 748 }
 749
 750 always_inline ip6_reass_rc_t
 751 ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 752                   ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 753                   ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 754                   ip6_frag_hdr_t * frag_hdr, bool is_custom_app)
 755 {
 756   int consumed = 0;
 757   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 758   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 759   if (is_custom_app)
 760     {
 761       reass->next_index = fvnb->ip.reass.next_index;    // store next_index before it's overwritten
 762       reass->error_next_index = fvnb->ip.reass.error_next_index;        // store error_next_index before it is overwritten
 763     }
 764
 765   fvnb->ip.reass.ip6_frag_hdr_offset =
 766     (u8 *) frag_hdr - (u8 *) vlib_buffer_get_current (fb);
 767   ip6_header_t *fip = vlib_buffer_get_current (fb);
 768   if (fb->current_length < sizeof (*fip) ||
 769       fvnb->ip.reass.ip6_frag_hdr_offset == 0 ||
 770       fvnb->ip.reass.ip6_frag_hdr_offset >= fb->current_length)
 771     {
 772       return IP6_REASS_RC_INTERNAL_ERROR;
 773     }
 774
 775   u32 fragment_first = fvnb->ip.reass.fragment_first =
 776     ip6_frag_hdr_offset_bytes (frag_hdr);
 777   u32 fragment_length =
 778     vlib_buffer_length_in_chain (vm, fb) -
 779     (fvnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 780   u32 fragment_last = fvnb->ip.reass.fragment_last =
 781     fragment_first + fragment_length - 1;
 782   int more_fragments = ip6_frag_hdr_more (frag_hdr);
 783   u32 candidate_range_bi = reass->first_bi;
 784   u32 prev_range_bi = ~0;
 785   fvnb->ip.reass.range_first = fragment_first;
 786   fvnb->ip.reass.range_last = fragment_last;
 787   fvnb->ip.reass.next_range_bi = ~0;
 788   if (!more_fragments)
 789     {
 790       reass->last_packet_octet = fragment_last;
 791     }
 792   if (~0 == reass->first_bi)
 793     {
 794       // starting a new reassembly
 795       ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 796                                        *bi0);
 797       reass->min_fragment_length = clib_net_to_host_u16 (fip->payload_length);
 798       consumed = 1;
 799       reass->fragments_n = 1;
 800       goto check_if_done_maybe;
 801     }
 802   reass->min_fragment_length =
 803     clib_min (clib_net_to_host_u16 (fip->payload_length),
 804               fvnb->ip.reass.estimated_mtu);
 805   while (~0 != candidate_range_bi)
 806     {
 807       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 808       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 809       if (fragment_first > candidate_vnb->ip.reass.range_last)
 810         {
 811           // this fragments starts after candidate range
 812           prev_range_bi = candidate_range_bi;
 813           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 814           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 815               ~0 == candidate_range_bi)
 816             {
 817               // special case - this fragment falls beyond all known ranges
 818               ip6_reass_insert_range_in_chain (vm, rm, rt, reass,
 819                                                prev_range_bi, *bi0);
 820               consumed = 1;
 821               break;
 822             }
 823           continue;
 824         }
 825       if (fragment_last < candidate_vnb->ip.reass.range_first)
 826         {
 827           // this fragment ends before candidate range without any overlap
 828           ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 829                                            *bi0);
 830           consumed = 1;
 831         }
 832       else if (fragment_first == candidate_vnb->ip.reass.range_first &&
 833                fragment_last == candidate_vnb->ip.reass.range_last)
 834         {
 835           // duplicate fragment - ignore
 836         }
 837       else
 838         {
 839           // overlapping fragment - not allowed by RFC 8200
 840           ip6_reass_drop_all (vm, node, rm, reass);
 841           ip6_reass_free (rm, rt, reass);
 842           if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 843             {
 844               ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_OVERLAP,
 845                                    0);
 846             }
 847           *next0 = IP6_REASSEMBLY_NEXT_DROP;
 848           *error0 = IP6_ERROR_REASS_OVERLAPPING_FRAGMENT;
 849           return IP6_REASS_RC_OK;
 850         }
 851       break;
 852     }
 853   ++reass->fragments_n;
 854 check_if_done_maybe:
 855   if (consumed)
 856     {
 857       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 858         {
 859           ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 860         }
 861     }
 862   if (~0 != reass->last_packet_octet &&
 863       reass->data_len == reass->last_packet_octet + 1)
 864     {
 865       return ip6_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 866                                  is_custom_app);
 867     }
 868   else
 869     {
 870       if (consumed)
 871         {
 872           *bi0 = ~0;
 873           if (reass->fragments_n > rm->max_reass_len)
 874             {
 875               return IP6_REASS_RC_TOO_MANY_FRAGMENTS;
 876             }
 877         }
 878       else
 879         {
 880           *next0 = IP6_REASSEMBLY_NEXT_DROP;
 881           *error0 = IP6_ERROR_REASS_DUPLICATE_FRAGMENT;
 882         }
 883     }
 884   return IP6_REASS_RC_OK;
 885 }
 886
 887 always_inline bool
 888 ip6_reass_verify_upper_layer_present (vlib_node_runtime_t * node,
 889                                       vlib_buffer_t * b,
 890                                       ip6_frag_hdr_t * frag_hdr)
 891 {
 892   ip6_ext_header_t *tmp = (ip6_ext_header_t *) frag_hdr;
 893   while (ip6_ext_hdr (tmp->next_hdr))
 894     {
 895       tmp = ip6_ext_next_header (tmp);
 896     }
 897   if (IP_PROTOCOL_IP6_NONXT == tmp->next_hdr)
 898     {
 899       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 900                                    ICMP6_parameter_problem_first_fragment_has_incomplete_header_chain,
 901                                    0);
 902       b->error = node->errors[IP6_ERROR_REASS_MISSING_UPPER];
 903
 904       return false;
 905     }
 906   return true;
 907 }
 908
 909 always_inline bool
 910 ip6_reass_verify_fragment_multiple_8 (vlib_main_t * vm,
 911                                       vlib_node_runtime_t * node,
 912                                       vlib_buffer_t * b,
 913                                       ip6_frag_hdr_t * frag_hdr)
 914 {
 915   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 916   ip6_header_t *ip = vlib_buffer_get_current (b);
 917   int more_fragments = ip6_frag_hdr_more (frag_hdr);
 918   u32 fragment_length =
 919     vlib_buffer_length_in_chain (vm, b) -
 920     (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 921   if (more_fragments && 0 != fragment_length % 8)
 922     {
 923       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 924                                    ICMP6_parameter_problem_erroneous_header_field,
 925                                    (u8 *) & ip->payload_length - (u8 *) ip);
 926       return false;
 927     }
 928   return true;
 929 }
 930
 931 always_inline bool
 932 ip6_reass_verify_packet_size_lt_64k (vlib_main_t * vm,
 933                                      vlib_node_runtime_t * node,
 934                                      vlib_buffer_t * b,
 935                                      ip6_frag_hdr_t * frag_hdr)
 936 {
 937   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 938   u32 fragment_first = ip6_frag_hdr_offset_bytes (frag_hdr);
 939   u32 fragment_length =
 940     vlib_buffer_length_in_chain (vm, b) -
 941     (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 942   if (fragment_first + fragment_length > 65535)
 943     {
 944       ip6_header_t *ip0 = vlib_buffer_get_current (b);
 945       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 946                                    ICMP6_parameter_problem_erroneous_header_field,
 947                                    (u8 *) & frag_hdr->fragment_offset_and_more
 948                                    - (u8 *) ip0);
 949       return false;
 950     }
 951   return true;
 952 }
 953
 954 always_inline uword
 955 ip6_reassembly_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 956                        vlib_frame_t * frame, bool is_feature,
 957                        bool is_custom_app)
 958 {
 959   u32 *from = vlib_frame_vector_args (frame);
 960   u32 n_left_from, n_left_to_next, *to_next, next_index;
 961   ip6_reass_main_t *rm = &ip6_reass_main;
 962   ip6_reass_per_thread_t *rt = &rm->per_thread_data[vm->thread_index];
 963   clib_spinlock_lock (&rt->lock);
 964
 965   n_left_from = frame->n_vectors;
 966   next_index = node->cached_next_index;
 967   while (n_left_from > 0)
 968     {
 969       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 970
 971       while (n_left_from > 0 && n_left_to_next > 0)
 972         {
 973           u32 bi0;
 974           vlib_buffer_t *b0;
 975           u32 next0 = IP6_REASSEMBLY_NEXT_DROP;
 976           u32 error0 = IP6_ERROR_NONE;
 977           u32 icmp_bi = ~0;
 978
 979           bi0 = from[0];
 980           b0 = vlib_get_buffer (vm, bi0);
 981
 982           ip6_header_t *ip0 = vlib_buffer_get_current (b0);
 983           ip6_frag_hdr_t *frag_hdr = NULL;
 984           ip6_ext_header_t *prev_hdr;
 985           if (ip6_ext_hdr (ip0->protocol))
 986             {
 987               ip6_ext_header_find_t (ip0, prev_hdr, frag_hdr,
 988                                      IP_PROTOCOL_IPV6_FRAGMENTATION);
 989             }
 990           if (!frag_hdr)
 991             {
 992               // this is a regular packet - no fragmentation
 993               next0 = IP6_REASSEMBLY_NEXT_INPUT;
 994               goto skip_reass;
 995             }
 996           if (0 == ip6_frag_hdr_offset (frag_hdr))
 997             {
 998               // first fragment - verify upper-layer is present
 999               if (!ip6_reass_verify_upper_layer_present (node, b0, frag_hdr))
1000                 {
1001                   next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
1002                   goto skip_reass;
1003                 }
1004             }
1005           if (!ip6_reass_verify_fragment_multiple_8 (vm, node, b0, frag_hdr)
1006               || !ip6_reass_verify_packet_size_lt_64k (vm, node, b0,
1007                                                        frag_hdr))
1008             {
1009               next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
1010               goto skip_reass;
1011             }
1012           vnet_buffer (b0)->ip.reass.ip6_frag_hdr_offset =
1013             (u8 *) frag_hdr - (u8 *) ip0;
1014
1015           ip6_reass_kv_t kv;
1016           u8 do_handoff = 0;
1017
1018           kv.k.as_u64[0] = ip0->src_address.as_u64[0];
1019           kv.k.as_u64[1] = ip0->src_address.as_u64[1];
1020           kv.k.as_u64[2] = ip0->dst_address.as_u64[0];
1021           kv.k.as_u64[3] = ip0->dst_address.as_u64[1];
1022           kv.k.as_u64[4] =
1023             ((u64) vec_elt (ip6_main.fib_index_by_sw_if_index,
1024                             vnet_buffer (b0)->sw_if_index[VLIB_RX])) << 32 |
1025             (u64) frag_hdr->identification;
1026           kv.k.as_u64[5] = ip0->protocol;
1027
1028           ip6_reass_t *reass =
1029             ip6_reass_find_or_create (vm, node, rm, rt, &kv, &icmp_bi,
1030                                       &do_handoff);
1031
1032           if (PREDICT_FALSE (do_handoff))
1033             {
1034               next0 = IP6_REASSEMBLY_NEXT_HANDOFF;
1035               if (is_feature)
1036                 vnet_buffer (b0)->ip.reass.owner_feature_thread_index =
1037                   kv.v.thread_index;
1038               else
1039                 vnet_buffer (b0)->ip.reass.owner_thread_index =
1040                   kv.v.thread_index;
1041             }
1042           else if (reass)
1043             {
1044               switch (ip6_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
1045                                         &error0, frag_hdr, is_custom_app))
1046                 {
1047                 case IP6_REASS_RC_OK:
1048                   /* nothing to do here */
1049                   break;
1050                 case IP6_REASS_RC_TOO_MANY_FRAGMENTS:
1051                   vlib_node_increment_counter (vm, node->node_index,
1052                                                IP6_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
1053                                                1);
1054                   ip6_reass_drop_all (vm, node, rm, reass);
1055                   ip6_reass_free (rm, rt, reass);
1056                   goto next_packet;
1057                   break;
1058                 case IP6_REASS_RC_NO_BUF:
1059                   vlib_node_increment_counter (vm, node->node_index,
1060                                                IP6_ERROR_REASS_NO_BUF, 1);
1061                   ip6_reass_drop_all (vm, node, rm, reass);
1062                   ip6_reass_free (rm, rt, reass);
1063                   goto next_packet;
1064                   break;
1065                 case IP6_REASS_RC_INTERNAL_ERROR:
1066                   /* drop everything and start with a clean slate */
1067                   vlib_node_increment_counter (vm, node->node_index,
1068                                                IP6_ERROR_REASS_INTERNAL_ERROR,
1069                                                1);
1070                   ip6_reass_drop_all (vm, node, rm, reass);
1071                   ip6_reass_free (rm, rt, reass);
1072                   goto next_packet;
1073                   break;
1074                 }
1075             }
1076           else
1077             {
1078               if (is_feature)
1079                 {
1080                   next0 = IP6_REASSEMBLY_NEXT_DROP;
1081                 }
1082               else
1083                 {
1084                   vnet_buffer_opaque_t *fvnb = vnet_buffer (b0);
1085                   next0 = fvnb->ip.reass.error_next_index;
1086                 }
1087               error0 = IP6_ERROR_REASS_LIMIT_REACHED;
1088             }
1089
1090           b0->error = node->errors[error0];
1091
1092           if (~0 != bi0)
1093             {
1094             skip_reass:
1095               to_next[0] = bi0;
1096               to_next += 1;
1097               n_left_to_next -= 1;
1098               if (is_feature && IP6_ERROR_NONE == error0)
1099                 {
1100                   b0 = vlib_get_buffer (vm, bi0);
1101                   vnet_feature_next (&next0, b0);
1102                 }
1103               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1104                                                n_left_to_next, bi0, next0);
1105             }
1106
1107           if (~0 != icmp_bi)
1108             {
1109               next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
1110               to_next[0] = icmp_bi;
1111               to_next += 1;
1112               n_left_to_next -= 1;
1113               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1114                                                n_left_to_next, icmp_bi,
1115                                                next0);
1116             }
1117         next_packet:
1118           from += 1;
1119           n_left_from -= 1;
1120         }
1121
1122       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1123     }
1124
1125   clib_spinlock_unlock (&rt->lock);
1126   return frame->n_vectors;
1127 }
1128
1129 static char *ip6_reassembly_error_strings[] = {
1130 #define _(sym, string) string,
1131   foreach_ip6_error
1132 #undef _
1133 };
1134
1135 VLIB_NODE_FN (ip6_reass_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
1136                                vlib_frame_t * frame)
1137 {
1138   return ip6_reassembly_inline (vm, node, frame, false /* is_feature */ ,
1139                                 false /* is_custom_app */ );
1140 }
1141
1142 /* *INDENT-OFF* */
1143 VLIB_REGISTER_NODE (ip6_reass_node) = {
1144     .name = "ip6-reassembly",
1145     .vector_size = sizeof (u32),
1146     .format_trace = format_ip6_reass_trace,
1147     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1148     .error_strings = ip6_reassembly_error_strings,
1149     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1150     .next_nodes =
1151         {
1152                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1153                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1154                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1155                 [IP6_REASSEMBLY_NEXT_HANDOFF] = "ip6-reassembly-handoff",
1156         },
1157 };
1158 /* *INDENT-ON* */
1159
1160 VLIB_NODE_FN (ip6_reass_node_feature) (vlib_main_t * vm,
1161                                        vlib_node_runtime_t * node,
1162                                        vlib_frame_t * frame)
1163 {
1164   return ip6_reassembly_inline (vm, node, frame, true /* is_feature */ ,
1165                                 false /* is_custom_app */ );
1166 }
1167
1168 /* *INDENT-OFF* */
1169 VLIB_REGISTER_NODE (ip6_reass_node_feature) = {
1170     .name = "ip6-reassembly-feature",
1171     .vector_size = sizeof (u32),
1172     .format_trace = format_ip6_reass_trace,
1173     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1174     .error_strings = ip6_reassembly_error_strings,
1175     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1176     .next_nodes =
1177         {
1178                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1179                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1180                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1181                 [IP6_REASSEMBLY_NEXT_HANDOFF] = "ip6-reass-feature-hoff",
1182         },
1183 };
1184 /* *INDENT-ON* */
1185
1186 /* *INDENT-OFF* */
1187 VNET_FEATURE_INIT (ip6_reassembly_feature, static) = {
1188     .arc_name = "ip6-unicast",
1189     .node_name = "ip6-reassembly-feature",
1190     .runs_before = VNET_FEATURES ("ip6-lookup"),
1191     .runs_after = 0,
1192 };
1193 /* *INDENT-ON* */
1194
1195 #ifndef CLIB_MARCH_VARIANT
1196 static u32
1197 ip6_reass_get_nbuckets ()
1198 {
1199   ip6_reass_main_t *rm = &ip6_reass_main;
1200   u32 nbuckets;
1201   u8 i;
1202
1203   nbuckets = (u32) (rm->max_reass_n / IP6_REASS_HT_LOAD_FACTOR);
1204
1205   for (i = 0; i < 31; i++)
1206     if ((1 << i) >= nbuckets)
1207       break;
1208   nbuckets = 1 << i;
1209
1210   return nbuckets;
1211 }
1212 #endif /* CLIB_MARCH_VARIANT */
1213
1214 typedef enum
1215 {
1216   IP6_EVENT_CONFIG_CHANGED = 1,
1217 } ip6_reass_event_t;
1218
1219 #ifndef CLIB_MARCH_VARIANT
1220 typedef struct
1221 {
1222   int failure;
1223   clib_bihash_48_8_t *new_hash;
1224 } ip6_rehash_cb_ctx;
1225
1226 static void
1227 ip6_rehash_cb (clib_bihash_kv_48_8_t * kv, void *_ctx)
1228 {
1229   ip6_rehash_cb_ctx *ctx = _ctx;
1230   if (clib_bihash_add_del_48_8 (ctx->new_hash, kv, 1))
1231     {
1232       ctx->failure = 1;
1233     }
1234 }
1235
1236 static void
1237 ip6_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1238                       u32 max_reassembly_length, u32 expire_walk_interval_ms)
1239 {
1240   ip6_reass_main.timeout_ms = timeout_ms;
1241   ip6_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1242   ip6_reass_main.max_reass_n = max_reassemblies;
1243   ip6_reass_main.max_reass_len = max_reassembly_length;
1244   ip6_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1245 }
1246
1247 vnet_api_error_t
1248 ip6_reass_set (u32 timeout_ms, u32 max_reassemblies,
1249                u32 max_reassembly_length, u32 expire_walk_interval_ms)
1250 {
1251   u32 old_nbuckets = ip6_reass_get_nbuckets ();
1252   ip6_reass_set_params (timeout_ms, max_reassemblies, max_reassembly_length,
1253                         expire_walk_interval_ms);
1254   vlib_process_signal_event (ip6_reass_main.vlib_main,
1255                              ip6_reass_main.ip6_reass_expire_node_idx,
1256                              IP6_EVENT_CONFIG_CHANGED, 0);
1257   u32 new_nbuckets = ip6_reass_get_nbuckets ();
1258   if (ip6_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1259     {
1260       clib_bihash_48_8_t new_hash;
1261       clib_memset (&new_hash, 0, sizeof (new_hash));
1262       ip6_rehash_cb_ctx ctx;
1263       ctx.failure = 0;
1264       ctx.new_hash = &new_hash;
1265       clib_bihash_init_48_8 (&new_hash, "ip6-reass", new_nbuckets,
1266                              new_nbuckets * 1024);
1267       clib_bihash_foreach_key_value_pair_48_8 (&ip6_reass_main.hash,
1268                                                ip6_rehash_cb, &ctx);
1269       if (ctx.failure)
1270         {
1271           clib_bihash_free_48_8 (&new_hash);
1272           return -1;
1273         }
1274       else
1275         {
1276           clib_bihash_free_48_8 (&ip6_reass_main.hash);
1277           clib_memcpy_fast (&ip6_reass_main.hash, &new_hash,
1278                             sizeof (ip6_reass_main.hash));
1279         }
1280     }
1281   return 0;
1282 }
1283
1284 vnet_api_error_t
1285 ip6_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1286                u32 * expire_walk_interval_ms)
1287 {
1288   *timeout_ms = ip6_reass_main.timeout_ms;
1289   *max_reassemblies = ip6_reass_main.max_reass_n;
1290   *expire_walk_interval_ms = ip6_reass_main.expire_walk_interval_ms;
1291   return 0;
1292 }
1293
1294 static clib_error_t *
1295 ip6_reass_init_function (vlib_main_t * vm)
1296 {
1297   ip6_reass_main_t *rm = &ip6_reass_main;
1298   clib_error_t *error = 0;
1299   u32 nbuckets;
1300   vlib_node_t *node;
1301
1302   rm->vlib_main = vm;
1303   rm->vnet_main = vnet_get_main ();
1304
1305   vec_validate (rm->per_thread_data, vlib_num_workers ());
1306   ip6_reass_per_thread_t *rt;
1307   vec_foreach (rt, rm->per_thread_data)
1308   {
1309     clib_spinlock_init (&rt->lock);
1310     pool_alloc (rt->pool, rm->max_reass_n);
1311   }
1312
1313   node = vlib_get_node_by_name (vm, (u8 *) "ip6-reassembly-expire-walk");
1314   ASSERT (node);
1315   rm->ip6_reass_expire_node_idx = node->index;
1316
1317   ip6_reass_set_params (IP6_REASS_TIMEOUT_DEFAULT_MS,
1318                         IP6_REASS_MAX_REASSEMBLIES_DEFAULT,
1319                         IP6_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT,
1320                         IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1321
1322   nbuckets = ip6_reass_get_nbuckets ();
1323   clib_bihash_init_48_8 (&rm->hash, "ip6-reass", nbuckets, nbuckets * 1024);
1324
1325   node = vlib_get_node_by_name (vm, (u8 *) "ip6-drop");
1326   ASSERT (node);
1327   rm->ip6_drop_idx = node->index;
1328   node = vlib_get_node_by_name (vm, (u8 *) "ip6-icmp-error");
1329   ASSERT (node);
1330   rm->ip6_icmp_error_idx = node->index;
1331
1332   if ((error = vlib_call_init_function (vm, ip_main_init)))
1333     return error;
1334   ip6_register_protocol (IP_PROTOCOL_IPV6_FRAGMENTATION,
1335                          ip6_reass_node.index);
1336
1337   rm->fq_index = vlib_frame_queue_main_init (ip6_reass_node.index, 0);
1338   rm->fq_feature_index =
1339     vlib_frame_queue_main_init (ip6_reass_node_feature.index, 0);
1340
1341   return error;
1342 }
1343
1344 VLIB_INIT_FUNCTION (ip6_reass_init_function);
1345 #endif /* CLIB_MARCH_VARIANT */
1346
1347 static uword
1348 ip6_reass_walk_expired (vlib_main_t * vm,
1349                         vlib_node_runtime_t * node, vlib_frame_t * f)
1350 {
1351   ip6_reass_main_t *rm = &ip6_reass_main;
1352   uword event_type, *event_data = 0;
1353
1354   while (true)
1355     {
1356       vlib_process_wait_for_event_or_clock (vm,
1357                                             (f64) rm->expire_walk_interval_ms
1358                                             / (f64) MSEC_PER_SEC);
1359       event_type = vlib_process_get_events (vm, &event_data);
1360
1361       switch (event_type)
1362         {
1363         case ~0:                /* no events => timeout */
1364           /* nothing to do here */
1365           break;
1366         case IP6_EVENT_CONFIG_CHANGED:
1367           break;
1368         default:
1369           clib_warning ("BUG: event type 0x%wx", event_type);
1370           break;
1371         }
1372       f64 now = vlib_time_now (vm);
1373
1374       ip6_reass_t *reass;
1375       int *pool_indexes_to_free = NULL;
1376
1377       uword thread_index = 0;
1378       int index;
1379       const uword nthreads = vlib_num_workers () + 1;
1380       u32 *vec_icmp_bi = NULL;
1381       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1382         {
1383           ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1384           clib_spinlock_lock (&rt->lock);
1385
1386           vec_reset_length (pool_indexes_to_free);
1387           /* *INDENT-OFF* */
1388           pool_foreach_index (index, rt->pool, ({
1389                                 reass = pool_elt_at_index (rt->pool, index);
1390                                 if (now > reass->last_heard + rm->timeout)
1391                                   {
1392                                     vec_add1 (pool_indexes_to_free, index);
1393                                   }
1394                               }));
1395           /* *INDENT-ON* */
1396           int *i;
1397           /* *INDENT-OFF* */
1398           vec_foreach (i, pool_indexes_to_free)
1399           {
1400             ip6_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1401             u32 icmp_bi = ~0;
1402             vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
1403             if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1404               {
1405                 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1406                                         b->trace_index))
1407                   {
1408                     /* the trace is gone, don't trace this buffer anymore */
1409                     b->flags &= ~VLIB_BUFFER_IS_TRACED;
1410                   }
1411               }
1412             ip6_reass_on_timeout (vm, node, rm, reass, &icmp_bi);
1413             if (~0 != icmp_bi)
1414               {
1415                 vec_add1 (vec_icmp_bi, icmp_bi);
1416               }
1417             ip6_reass_free (rm, rt, reass);
1418           }
1419           /* *INDENT-ON* */
1420
1421           clib_spinlock_unlock (&rt->lock);
1422         }
1423
1424       while (vec_len (vec_icmp_bi) > 0)
1425         {
1426           vlib_frame_t *f =
1427             vlib_get_frame_to_node (vm, rm->ip6_icmp_error_idx);
1428           u32 *to_next = vlib_frame_vector_args (f);
1429           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1430           int trace_frame = 0;
1431           while (vec_len (vec_icmp_bi) > 0 && n_left_to_next > 0)
1432             {
1433               u32 bi = vec_pop (vec_icmp_bi);
1434               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1435               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1436                 {
1437                   if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1438                                           b->trace_index))
1439                     {
1440                       /* the trace is gone, don't trace this buffer anymore */
1441                       b->flags &= ~VLIB_BUFFER_IS_TRACED;
1442                     }
1443                   else
1444                     {
1445                       trace_frame = 1;
1446                     }
1447                 }
1448               b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
1449               to_next[0] = bi;
1450               ++f->n_vectors;
1451               to_next += 1;
1452               n_left_to_next -= 1;
1453             }
1454           f->frame_flags |= (trace_frame * VLIB_FRAME_TRACE);
1455           vlib_put_frame_to_node (vm, rm->ip6_icmp_error_idx, f);
1456         }
1457
1458       vec_free (pool_indexes_to_free);
1459       vec_free (vec_icmp_bi);
1460       if (event_data)
1461         {
1462           _vec_len (event_data) = 0;
1463         }
1464     }
1465
1466   return 0;
1467 }
1468
1469 /* *INDENT-OFF* */
1470 VLIB_REGISTER_NODE (ip6_reass_expire_node, static) = {
1471     .function = ip6_reass_walk_expired,
1472     .format_trace = format_ip6_reass_trace,
1473     .type = VLIB_NODE_TYPE_PROCESS,
1474     .name = "ip6-reassembly-expire-walk",
1475
1476     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1477     .error_strings = ip6_reassembly_error_strings,
1478
1479 };
1480 /* *INDENT-ON* */
1481
1482 static u8 *
1483 format_ip6_reass_key (u8 * s, va_list * args)
1484 {
1485   ip6_reass_key_t *key = va_arg (*args, ip6_reass_key_t *);
1486   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1487               key->xx_id, format_ip6_address, &key->src, format_ip6_address,
1488               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1489   return s;
1490 }
1491
1492 static u8 *
1493 format_ip6_reass (u8 * s, va_list * args)
1494 {
1495   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1496   ip6_reass_t *reass = va_arg (*args, ip6_reass_t *);
1497
1498   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1499               "last_packet_octet: %u, trace_op_counter: %u\n",
1500               reass->id, format_ip6_reass_key, &reass->key, reass->first_bi,
1501               reass->data_len, reass->last_packet_octet,
1502               reass->trace_op_counter);
1503   u32 bi = reass->first_bi;
1504   u32 counter = 0;
1505   while (~0 != bi)
1506     {
1507       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1508       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1509       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1510                   "fragment[%u, %u]\n",
1511                   counter, vnb->ip.reass.range_first,
1512                   vnb->ip.reass.range_last, bi,
1513                   ip6_reass_buffer_get_data_offset (b),
1514                   ip6_reass_buffer_get_data_len (b),
1515                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1516       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1517         {
1518           bi = b->next_buffer;
1519         }
1520       else
1521         {
1522           bi = ~0;
1523         }
1524     }
1525   return s;
1526 }
1527
1528 static clib_error_t *
1529 show_ip6_reass (vlib_main_t * vm, unformat_input_t * input,
1530                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1531 {
1532   ip6_reass_main_t *rm = &ip6_reass_main;
1533
1534   vlib_cli_output (vm, "---------------------");
1535   vlib_cli_output (vm, "IP6 reassembly status");
1536   vlib_cli_output (vm, "---------------------");
1537   bool details = false;
1538   if (unformat (input, "details"))
1539     {
1540       details = true;
1541     }
1542
1543   u32 sum_reass_n = 0;
1544   u64 sum_buffers_n = 0;
1545   ip6_reass_t *reass;
1546   uword thread_index;
1547   const uword nthreads = vlib_num_workers () + 1;
1548   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1549     {
1550       ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1551       clib_spinlock_lock (&rt->lock);
1552       if (details)
1553         {
1554           /* *INDENT-OFF* */
1555           pool_foreach (reass, rt->pool, {
1556             vlib_cli_output (vm, "%U", format_ip6_reass, vm, reass);
1557           });
1558           /* *INDENT-ON* */
1559         }
1560       sum_reass_n += rt->reass_n;
1561       clib_spinlock_unlock (&rt->lock);
1562     }
1563   vlib_cli_output (vm, "---------------------");
1564   vlib_cli_output (vm, "Current IP6 reassemblies count: %lu\n",
1565                    (long unsigned) sum_reass_n);
1566   vlib_cli_output (vm, "Maximum configured concurrent IP6 reassemblies per "
1567                    "worker-thread: %lu\n", (long unsigned) rm->max_reass_n);
1568   vlib_cli_output (vm, "Buffers in use: %lu\n",
1569                    (long unsigned) sum_buffers_n);
1570   return 0;
1571 }
1572
1573 /* *INDENT-OFF* */
1574 VLIB_CLI_COMMAND (show_ip6_reassembly_cmd, static) = {
1575     .path = "show ip6-reassembly",
1576     .short_help = "show ip6-reassembly [details]",
1577     .function = show_ip6_reass,
1578 };
1579 /* *INDENT-ON* */
1580
1581 #ifndef CLIB_MARCH_VARIANT
1582 vnet_api_error_t
1583 ip6_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1584 {
1585   return vnet_feature_enable_disable ("ip6-unicast", "ip6-reassembly-feature",
1586                                       sw_if_index, enable_disable, 0, 0);
1587 }
1588 #endif /* CLIB_MARCH_VARIANT */
1589
1590 #define foreach_ip6_reassembly_handoff_error                       \
1591 _(CONGESTION_DROP, "congestion drop")
1592
1593
1594 typedef enum
1595 {
1596 #define _(sym,str) IP6_REASSEMBLY_HANDOFF_ERROR_##sym,
1597   foreach_ip6_reassembly_handoff_error
1598 #undef _
1599     IP6_REASSEMBLY_HANDOFF_N_ERROR,
1600 } ip6_reassembly_handoff_error_t;
1601
1602 static char *ip6_reassembly_handoff_error_strings[] = {
1603 #define _(sym,string) string,
1604   foreach_ip6_reassembly_handoff_error
1605 #undef _
1606 };
1607
1608 typedef struct
1609 {
1610   u32 next_worker_index;
1611 } ip6_reassembly_handoff_trace_t;
1612
1613 static u8 *
1614 format_ip6_reassembly_handoff_trace (u8 * s, va_list * args)
1615 {
1616   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1617   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1618   ip6_reassembly_handoff_trace_t *t =
1619     va_arg (*args, ip6_reassembly_handoff_trace_t *);
1620
1621   s =
1622     format (s, "ip6-reassembly-handoff: next-worker %d",
1623             t->next_worker_index);
1624
1625   return s;
1626 }
1627
1628 always_inline uword
1629 ip6_reassembly_handoff_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1630                                vlib_frame_t * frame, bool is_feature)
1631 {
1632   ip6_reass_main_t *rm = &ip6_reass_main;
1633
1634   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
1635   u32 n_enq, n_left_from, *from;
1636   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
1637   u32 fq_index;
1638
1639   from = vlib_frame_vector_args (frame);
1640   n_left_from = frame->n_vectors;
1641   vlib_get_buffers (vm, from, bufs, n_left_from);
1642
1643   b = bufs;
1644   ti = thread_indices;
1645
1646   fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index;
1647
1648   while (n_left_from > 0)
1649     {
1650       ti[0] =
1651         (is_feature) ? vnet_buffer (b[0])->ip.
1652         reass.owner_feature_thread_index : vnet_buffer (b[0])->ip.
1653         reass.owner_thread_index;
1654
1655       if (PREDICT_FALSE
1656           ((node->flags & VLIB_NODE_FLAG_TRACE)
1657            && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
1658         {
1659           ip6_reassembly_handoff_trace_t *t =
1660             vlib_add_trace (vm, node, b[0], sizeof (*t));
1661           t->next_worker_index = ti[0];
1662         }
1663
1664       n_left_from -= 1;
1665       ti += 1;
1666       b += 1;
1667     }
1668   n_enq =
1669     vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
1670                                    frame->n_vectors, 1);
1671
1672   if (n_enq < frame->n_vectors)
1673     vlib_node_increment_counter (vm, node->node_index,
1674                                  IP6_REASSEMBLY_HANDOFF_ERROR_CONGESTION_DROP,
1675                                  frame->n_vectors - n_enq);
1676   return frame->n_vectors;
1677 }
1678
1679 VLIB_NODE_FN (ip6_reassembly_handoff_node) (vlib_main_t * vm,
1680                                             vlib_node_runtime_t * node,
1681                                             vlib_frame_t * frame)
1682 {
1683   return ip6_reassembly_handoff_inline (vm, node, frame,
1684                                         false /* is_feature */ );
1685 }
1686
1687 /* *INDENT-OFF* */
1688 VLIB_REGISTER_NODE (ip6_reassembly_handoff_node) = {
1689   .name = "ip6-reassembly-handoff",
1690   .vector_size = sizeof (u32),
1691   .n_errors = ARRAY_LEN(ip6_reassembly_handoff_error_strings),
1692   .error_strings = ip6_reassembly_handoff_error_strings,
1693   .format_trace = format_ip6_reassembly_handoff_trace,
1694
1695   .n_next_nodes = 1,
1696
1697   .next_nodes = {
1698     [0] = "error-drop",
1699   },
1700 };
1701
1702
1703 VLIB_NODE_FN (ip6_reassembly_feature_handoff_node) (vlib_main_t * vm,
1704                                vlib_node_runtime_t * node, vlib_frame_t * frame)
1705 {
1706   return ip6_reassembly_handoff_inline (vm, node, frame, true /* is_feature */ );
1707 }
1708
1709
1710 /* *INDENT-OFF* */
1711 VLIB_REGISTER_NODE (ip6_reassembly_feature_handoff_node) = {
1712   .name = "ip6-reass-feature-hoff",
1713   .vector_size = sizeof (u32),
1714   .n_errors = ARRAY_LEN(ip6_reassembly_handoff_error_strings),
1715   .error_strings = ip6_reassembly_handoff_error_strings,
1716   .format_trace = format_ip6_reassembly_handoff_trace,
1717
1718   .n_next_nodes = 1,
1719
1720   .next_nodes = {
1721     [0] = "error-drop",
1722   },
1723 };
1724 /* *INDENT-ON* */
1725
1726 /*
1727  * fd.io coding-style-patch-verification: ON
1728  *
1729  * Local Variables:
1730  * eval: (c-set-style "gnu")
1731  * End:
1732  */