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   ip6_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 284   t->reass_id = reass->id;
 285   t->action = action;
 286   ip6_reass_trace_details (vm, bi, &t->trace_range);
 287   t->size_diff = size_diff;
 288   t->op_id = reass->trace_op_counter;
 289   ++reass->trace_op_counter;
 290   t->fragment_first = vnb->ip.reass.fragment_first;
 291   t->fragment_last = vnb->ip.reass.fragment_last;
 292   t->trace_range.first_bi = reass->first_bi;
 293   t->total_data_len = reass->data_len;
 294 #if 0
 295   static u8 *s = NULL;
 296   s = format (s, "%U", format_ip6_reass_trace, NULL, NULL, t);
 297   printf ("%.*s\n", vec_len (s), s);
 298   fflush (stdout);
 299   vec_reset_length (s);
 300 #endif
 301 }
 302
 303 always_inline void
 304 ip6_reass_free (ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 305                 ip6_reass_t * reass)
 306 {
 307   clib_bihash_kv_48_8_t kv;
 308   kv.key[0] = reass->key.as_u64[0];
 309   kv.key[1] = reass->key.as_u64[1];
 310   kv.key[2] = reass->key.as_u64[2];
 311   kv.key[3] = reass->key.as_u64[3];
 312   kv.key[4] = reass->key.as_u64[4];
 313   kv.key[5] = reass->key.as_u64[5];
 314   clib_bihash_add_del_48_8 (&rm->hash, &kv, 0);
 315   pool_put (rt->pool, reass);
 316   --rt->reass_n;
 317 }
 318
 319 always_inline void
 320 ip6_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
 321                     ip6_reass_main_t * rm, ip6_reass_t * reass)
 322 {
 323   u32 range_bi = reass->first_bi;
 324   vlib_buffer_t *range_b;
 325   vnet_buffer_opaque_t *range_vnb;
 326   u32 *to_free = NULL;
 327   while (~0 != range_bi)
 328     {
 329       range_b = vlib_get_buffer (vm, range_bi);
 330       range_vnb = vnet_buffer (range_b);
 331       u32 bi = range_bi;
 332       while (~0 != bi)
 333         {
 334           vec_add1 (to_free, bi);
 335           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 336           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 337             {
 338               bi = b->next_buffer;
 339               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 340             }
 341           else
 342             {
 343               bi = ~0;
 344             }
 345         }
 346       range_bi = range_vnb->ip.reass.next_range_bi;
 347     }
 348   /* send to next_error_index */
 349   if (~0 != reass->error_next_index)
 350     {
 351       u32 n_left_to_next, *to_next, next_index;
 352
 353       next_index = reass->error_next_index;
 354       u32 bi = ~0;
 355
 356       while (vec_len (to_free) > 0)
 357         {
 358           vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 359
 360           while (vec_len (to_free) > 0 && n_left_to_next > 0)
 361             {
 362               bi = vec_pop (to_free);
 363
 364               if (~0 != bi)
 365                 {
 366                   to_next[0] = bi;
 367                   to_next += 1;
 368                   n_left_to_next -= 1;
 369                   vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 370                                                    to_next, n_left_to_next,
 371                                                    bi, next_index);
 372                 }
 373             }
 374           vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 375         }
 376     }
 377   else
 378     {
 379       vlib_buffer_free (vm, to_free, vec_len (to_free));
 380     }
 381   vec_free (to_free);
 382 }
 383
 384 always_inline void
 385 ip6_reass_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * node,
 386                       ip6_reass_main_t * rm, ip6_reass_t * reass,
 387                       u32 * icmp_bi)
 388 {
 389   if (~0 == reass->first_bi)
 390     {
 391       return;
 392     }
 393   if (~0 == reass->next_index)  // custom apps don't want icmp
 394     {
 395       vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
 396       if (0 == vnet_buffer (b)->ip.reass.fragment_first)
 397         {
 398           *icmp_bi = reass->first_bi;
 399           if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
 400             {
 401               ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi,
 402                                    ICMP_ERROR_RT_EXCEEDED, 0);
 403             }
 404           // fragment with offset zero received - send icmp message back
 405           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 406             {
 407               // separate first buffer from chain and steer it towards icmp node
 408               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 409               reass->first_bi = b->next_buffer;
 410             }
 411           else
 412             {
 413               reass->first_bi = vnet_buffer (b)->ip.reass.next_range_bi;
 414             }
 415           icmp6_error_set_vnet_buffer (b, ICMP6_time_exceeded,
 416                                        ICMP6_time_exceeded_fragment_reassembly_time_exceeded,
 417                                        0);
 418         }
 419     }
 420   ip6_reass_drop_all (vm, node, rm, reass);
 421 }
 422
 423 always_inline ip6_reass_t *
 424 ip6_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 425                           ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 426                           ip6_reass_kv_t * kv, u32 * icmp_bi, u8 * do_handoff)
 427 {
 428   ip6_reass_t *reass = NULL;
 429   f64 now = vlib_time_now (rm->vlib_main);
 430
 431   if (!clib_bihash_search_48_8
 432       (&rm->hash, (clib_bihash_kv_48_8_t *) kv, (clib_bihash_kv_48_8_t *) kv))
 433     {
 434       if (vm->thread_index != kv->v.thread_index)
 435         {
 436           *do_handoff = 1;
 437           return NULL;
 438         }
 439       reass = pool_elt_at_index (rt->pool, kv->v.reass_index);
 440
 441       if (now > reass->last_heard + rm->timeout)
 442         {
 443           ip6_reass_on_timeout (vm, node, rm, reass, icmp_bi);
 444           ip6_reass_free (rm, rt, reass);
 445           reass = NULL;
 446         }
 447     }
 448
 449   if (reass)
 450     {
 451       reass->last_heard = now;
 452       return reass;
 453     }
 454
 455   if (rt->reass_n >= rm->max_reass_n)
 456     {
 457       reass = NULL;
 458       return reass;
 459     }
 460   else
 461     {
 462       pool_get (rt->pool, reass);
 463       clib_memset (reass, 0, sizeof (*reass));
 464       reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter;
 465       ++rt->id_counter;
 466       reass->first_bi = ~0;
 467       reass->last_packet_octet = ~0;
 468       reass->data_len = 0;
 469       reass->next_index = ~0;
 470       reass->error_next_index = ~0;
 471       ++rt->reass_n;
 472     }
 473
 474   reass->key.as_u64[0] = ((clib_bihash_kv_48_8_t *) kv)->key[0];
 475   reass->key.as_u64[1] = ((clib_bihash_kv_48_8_t *) kv)->key[1];
 476   reass->key.as_u64[2] = ((clib_bihash_kv_48_8_t *) kv)->key[2];
 477   reass->key.as_u64[3] = ((clib_bihash_kv_48_8_t *) kv)->key[3];
 478   reass->key.as_u64[4] = ((clib_bihash_kv_48_8_t *) kv)->key[4];
 479   reass->key.as_u64[5] = ((clib_bihash_kv_48_8_t *) kv)->key[5];
 480   kv->v.reass_index = (reass - rt->pool);
 481   kv->v.thread_index = vm->thread_index;
 482   reass->last_heard = now;
 483
 484   if (clib_bihash_add_del_48_8 (&rm->hash, (clib_bihash_kv_48_8_t *) kv, 1))
 485     {
 486       ip6_reass_free (rm, rt, reass);
 487       reass = NULL;
 488     }
 489
 490   return reass;
 491 }
 492
 493 always_inline ip6_reass_rc_t
 494 ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 495                     ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 496                     ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 497                     bool is_custom_app)
 498 {
 499   *bi0 = reass->first_bi;
 500   *error0 = IP6_ERROR_NONE;
 501   ip6_frag_hdr_t *frag_hdr;
 502   vlib_buffer_t *last_b = NULL;
 503   u32 sub_chain_bi = reass->first_bi;
 504   u32 total_length = 0;
 505   u32 buf_cnt = 0;
 506   u32 dropped_cnt = 0;
 507   u32 *vec_drop_compress = NULL;
 508   ip6_reass_rc_t rv = IP6_REASS_RC_OK;
 509   do
 510     {
 511       u32 tmp_bi = sub_chain_bi;
 512       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 513       vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
 514       if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 515           !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 516         {
 517           rv = IP6_REASS_RC_INTERNAL_ERROR;
 518           goto free_buffers_and_return;
 519         }
 520
 521       u32 data_len = ip6_reass_buffer_get_data_len (tmp);
 522       u32 trim_front = vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 523         sizeof (*frag_hdr) + ip6_reass_buffer_get_data_offset (tmp);
 524       u32 trim_end =
 525         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 526       if (tmp_bi == reass->first_bi)
 527         {
 528           /* first buffer - keep ip6 header */
 529           if (0 != ip6_reass_buffer_get_data_offset (tmp))
 530             {
 531               rv = IP6_REASS_RC_INTERNAL_ERROR;
 532               goto free_buffers_and_return;
 533             }
 534           trim_front = 0;
 535           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 536             (vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 537              sizeof (*frag_hdr));
 538           if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
 539             {
 540               rv = IP6_REASS_RC_INTERNAL_ERROR;
 541               goto free_buffers_and_return;
 542             }
 543         }
 544       u32 keep_data =
 545         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 546       while (1)
 547         {
 548           ++buf_cnt;
 549           if (trim_front)
 550             {
 551               if (trim_front > tmp->current_length)
 552                 {
 553                   /* drop whole buffer */
 554                   vec_add1 (vec_drop_compress, tmp_bi);
 555                   trim_front -= tmp->current_length;
 556                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 557                     {
 558                       rv = IP6_REASS_RC_INTERNAL_ERROR;
 559                       goto free_buffers_and_return;
 560                     }
 561                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 562                   tmp_bi = tmp->next_buffer;
 563                   tmp = vlib_get_buffer (vm, tmp_bi);
 564                   continue;
 565                 }
 566               else
 567                 {
 568                   vlib_buffer_advance (tmp, trim_front);
 569                   trim_front = 0;
 570                 }
 571             }
 572           if (keep_data)
 573             {
 574               if (last_b)
 575                 {
 576                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 577                   last_b->next_buffer = tmp_bi;
 578                 }
 579               last_b = tmp;
 580               if (keep_data <= tmp->current_length)
 581                 {
 582                   tmp->current_length = keep_data;
 583                   keep_data = 0;
 584                 }
 585               else
 586                 {
 587                   keep_data -= tmp->current_length;
 588                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 589                     {
 590                       rv = IP6_REASS_RC_INTERNAL_ERROR;
 591                       goto free_buffers_and_return;
 592                     }
 593                 }
 594               total_length += tmp->current_length;
 595             }
 596           else
 597             {
 598               vec_add1 (vec_drop_compress, tmp_bi);
 599               if (reass->first_bi == tmp_bi)
 600                 {
 601                   rv = IP6_REASS_RC_INTERNAL_ERROR;
 602                   goto free_buffers_and_return;
 603                 }
 604               ++dropped_cnt;
 605             }
 606           if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 607             {
 608               tmp_bi = tmp->next_buffer;
 609               tmp = vlib_get_buffer (vm, tmp->next_buffer);
 610             }
 611           else
 612             {
 613               break;
 614             }
 615         }
 616       sub_chain_bi =
 617         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 618         reass.next_range_bi;
 619     }
 620   while (~0 != sub_chain_bi);
 621
 622   if (!last_b)
 623     {
 624       rv = IP6_REASS_RC_INTERNAL_ERROR;
 625       goto free_buffers_and_return;
 626     }
 627   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 628   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 629   if (total_length < first_b->current_length)
 630     {
 631       rv = IP6_REASS_RC_INTERNAL_ERROR;
 632       goto free_buffers_and_return;
 633     }
 634   total_length -= first_b->current_length;
 635   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 636   first_b->total_length_not_including_first_buffer = total_length;
 637   // drop fragment header
 638   vnet_buffer_opaque_t *first_b_vnb = vnet_buffer (first_b);
 639   ip6_header_t *ip = vlib_buffer_get_current (first_b);
 640   u16 ip6_frag_hdr_offset = first_b_vnb->ip.reass.ip6_frag_hdr_offset;
 641   ip6_ext_header_t *prev_hdr;
 642   ip6_ext_header_find_t (ip, prev_hdr, frag_hdr,
 643                          IP_PROTOCOL_IPV6_FRAGMENTATION);
 644   if (prev_hdr)
 645     {
 646       prev_hdr->next_hdr = frag_hdr->next_hdr;
 647     }
 648   else
 649     {
 650       ip->protocol = frag_hdr->next_hdr;
 651     }
 652   if (!((u8 *) frag_hdr - (u8 *) ip == ip6_frag_hdr_offset))
 653     {
 654       rv = IP6_REASS_RC_INTERNAL_ERROR;
 655       goto free_buffers_and_return;
 656     }
 657   memmove (frag_hdr, (u8 *) frag_hdr + sizeof (*frag_hdr),
 658            first_b->current_length - ip6_frag_hdr_offset -
 659            sizeof (ip6_frag_hdr_t));
 660   first_b->current_length -= sizeof (*frag_hdr);
 661   ip->payload_length =
 662     clib_host_to_net_u16 (total_length + first_b->current_length -
 663                           sizeof (*ip));
 664   if (!vlib_buffer_chain_linearize (vm, first_b))
 665     {
 666       rv = IP6_REASS_RC_NO_BUF;
 667       goto free_buffers_and_return;
 668     }
 669   first_b->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
 670   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 671     {
 672       ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 673 #if 0
 674       // following code does a hexdump of packet fragments to stdout ...
 675       do
 676         {
 677           u32 bi = reass->first_bi;
 678           u8 *s = NULL;
 679           while (~0 != bi)
 680             {
 681               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 682               s = format (s, "%u: %U\n", bi, format_hexdump,
 683                           vlib_buffer_get_current (b), b->current_length);
 684               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 685                 {
 686                   bi = b->next_buffer;
 687                 }
 688               else
 689                 {
 690                   break;
 691                 }
 692             }
 693           printf ("%.*s\n", vec_len (s), s);
 694           fflush (stdout);
 695           vec_free (s);
 696         }
 697       while (0);
 698 #endif
 699     }
 700   if (!is_custom_app)
 701     {
 702       *next0 = IP6_REASSEMBLY_NEXT_INPUT;
 703     }
 704   else
 705     {
 706       *next0 = reass->next_index;
 707     }
 708   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 709   ip6_reass_free (rm, rt, reass);
 710   reass = NULL;
 711 free_buffers_and_return:
 712   vlib_buffer_free (vm, vec_drop_compress, vec_len (vec_drop_compress));
 713   vec_free (vec_drop_compress);
 714   return rv;
 715 }
 716
 717 always_inline void
 718 ip6_reass_insert_range_in_chain (vlib_main_t * vm, ip6_reass_main_t * rm,
 719                                  ip6_reass_per_thread_t * rt,
 720                                  ip6_reass_t * reass, u32 prev_range_bi,
 721                                  u32 new_next_bi)
 722 {
 723
 724   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 725   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 726   if (~0 != prev_range_bi)
 727     {
 728       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 729       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 730       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 731       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 732     }
 733   else
 734     {
 735       if (~0 != reass->first_bi)
 736         {
 737           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 738         }
 739       reass->first_bi = new_next_bi;
 740     }
 741   reass->data_len += ip6_reass_buffer_get_data_len (new_next_b);
 742 }
 743
 744 always_inline ip6_reass_rc_t
 745 ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 746                   ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 747                   ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 748                   ip6_frag_hdr_t * frag_hdr, bool is_custom_app)
 749 {
 750   int consumed = 0;
 751   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 752   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 753   if (is_custom_app)
 754     {
 755       reass->next_index = fvnb->ip.reass.next_index;    // store next_index before it's overwritten
 756       reass->error_next_index = fvnb->ip.reass.error_next_index;        // store error_next_index before it is overwritten
 757     }
 758
 759   fvnb->ip.reass.ip6_frag_hdr_offset =
 760     (u8 *) frag_hdr - (u8 *) vlib_buffer_get_current (fb);
 761   ip6_header_t *fip = vlib_buffer_get_current (fb);
 762   if (fb->current_length < sizeof (*fip) ||
 763       fvnb->ip.reass.ip6_frag_hdr_offset == 0 ||
 764       fvnb->ip.reass.ip6_frag_hdr_offset >= fb->current_length)
 765     {
 766       return IP6_REASS_RC_INTERNAL_ERROR;
 767     }
 768
 769   u32 fragment_first = fvnb->ip.reass.fragment_first =
 770     ip6_frag_hdr_offset_bytes (frag_hdr);
 771   u32 fragment_length =
 772     vlib_buffer_length_in_chain (vm, fb) -
 773     (fvnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 774   u32 fragment_last = fvnb->ip.reass.fragment_last =
 775     fragment_first + fragment_length - 1;
 776   int more_fragments = ip6_frag_hdr_more (frag_hdr);
 777   u32 candidate_range_bi = reass->first_bi;
 778   u32 prev_range_bi = ~0;
 779   fvnb->ip.reass.range_first = fragment_first;
 780   fvnb->ip.reass.range_last = fragment_last;
 781   fvnb->ip.reass.next_range_bi = ~0;
 782   if (!more_fragments)
 783     {
 784       reass->last_packet_octet = fragment_last;
 785     }
 786   if (~0 == reass->first_bi)
 787     {
 788       // starting a new reassembly
 789       ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 790                                        *bi0);
 791       reass->min_fragment_length = clib_net_to_host_u16 (fip->payload_length);
 792       consumed = 1;
 793       reass->fragments_n = 1;
 794       goto check_if_done_maybe;
 795     }
 796   reass->min_fragment_length =
 797     clib_min (clib_net_to_host_u16 (fip->payload_length),
 798               fvnb->ip.reass.estimated_mtu);
 799   while (~0 != candidate_range_bi)
 800     {
 801       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 802       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 803       if (fragment_first > candidate_vnb->ip.reass.range_last)
 804         {
 805           // this fragments starts after candidate range
 806           prev_range_bi = candidate_range_bi;
 807           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 808           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 809               ~0 == candidate_range_bi)
 810             {
 811               // special case - this fragment falls beyond all known ranges
 812               ip6_reass_insert_range_in_chain (vm, rm, rt, reass,
 813                                                prev_range_bi, *bi0);
 814               consumed = 1;
 815               break;
 816             }
 817           continue;
 818         }
 819       if (fragment_last < candidate_vnb->ip.reass.range_first)
 820         {
 821           // this fragment ends before candidate range without any overlap
 822           ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 823                                            *bi0);
 824           consumed = 1;
 825         }
 826       else if (fragment_first == candidate_vnb->ip.reass.range_first &&
 827                fragment_last == candidate_vnb->ip.reass.range_last)
 828         {
 829           // duplicate fragment - ignore
 830         }
 831       else
 832         {
 833           // overlapping fragment - not allowed by RFC 8200
 834           ip6_reass_drop_all (vm, node, rm, reass);
 835           ip6_reass_free (rm, rt, reass);
 836           if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 837             {
 838               ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_OVERLAP,
 839                                    0);
 840             }
 841           *next0 = IP6_REASSEMBLY_NEXT_DROP;
 842           *error0 = IP6_ERROR_REASS_OVERLAPPING_FRAGMENT;
 843           return IP6_REASS_RC_OK;
 844         }
 845       break;
 846     }
 847   ++reass->fragments_n;
 848 check_if_done_maybe:
 849   if (consumed)
 850     {
 851       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 852         {
 853           ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 854         }
 855     }
 856   if (~0 != reass->last_packet_octet &&
 857       reass->data_len == reass->last_packet_octet + 1)
 858     {
 859       return ip6_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 860                                  is_custom_app);
 861     }
 862   else
 863     {
 864       if (consumed)
 865         {
 866           *bi0 = ~0;
 867           if (reass->fragments_n > rm->max_reass_len)
 868             {
 869               return IP6_REASS_RC_TOO_MANY_FRAGMENTS;
 870             }
 871         }
 872       else
 873         {
 874           *next0 = IP6_REASSEMBLY_NEXT_DROP;
 875           *error0 = IP6_ERROR_REASS_DUPLICATE_FRAGMENT;
 876         }
 877     }
 878   return IP6_REASS_RC_OK;
 879 }
 880
 881 always_inline bool
 882 ip6_reass_verify_upper_layer_present (vlib_node_runtime_t * node,
 883                                       vlib_buffer_t * b,
 884                                       ip6_frag_hdr_t * frag_hdr)
 885 {
 886   ip6_ext_header_t *tmp = (ip6_ext_header_t *) frag_hdr;
 887   while (ip6_ext_hdr (tmp->next_hdr))
 888     {
 889       tmp = ip6_ext_next_header (tmp);
 890     }
 891   if (IP_PROTOCOL_IP6_NONXT == tmp->next_hdr)
 892     {
 893       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 894                                    ICMP6_parameter_problem_first_fragment_has_incomplete_header_chain,
 895                                    0);
 896       b->error = node->errors[IP6_ERROR_REASS_MISSING_UPPER];
 897
 898       return false;
 899     }
 900   return true;
 901 }
 902
 903 always_inline bool
 904 ip6_reass_verify_fragment_multiple_8 (vlib_main_t * vm,
 905                                       vlib_node_runtime_t * node,
 906                                       vlib_buffer_t * b,
 907                                       ip6_frag_hdr_t * frag_hdr)
 908 {
 909   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 910   ip6_header_t *ip = vlib_buffer_get_current (b);
 911   int more_fragments = ip6_frag_hdr_more (frag_hdr);
 912   u32 fragment_length =
 913     vlib_buffer_length_in_chain (vm, b) -
 914     (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 915   if (more_fragments && 0 != fragment_length % 8)
 916     {
 917       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 918                                    ICMP6_parameter_problem_erroneous_header_field,
 919                                    (u8 *) & ip->payload_length - (u8 *) ip);
 920       return false;
 921     }
 922   return true;
 923 }
 924
 925 always_inline bool
 926 ip6_reass_verify_packet_size_lt_64k (vlib_main_t * vm,
 927                                      vlib_node_runtime_t * node,
 928                                      vlib_buffer_t * b,
 929                                      ip6_frag_hdr_t * frag_hdr)
 930 {
 931   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 932   u32 fragment_first = ip6_frag_hdr_offset_bytes (frag_hdr);
 933   u32 fragment_length =
 934     vlib_buffer_length_in_chain (vm, b) -
 935     (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 936   if (fragment_first + fragment_length > 65535)
 937     {
 938       ip6_header_t *ip0 = vlib_buffer_get_current (b);
 939       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 940                                    ICMP6_parameter_problem_erroneous_header_field,
 941                                    (u8 *) & frag_hdr->fragment_offset_and_more
 942                                    - (u8 *) ip0);
 943       return false;
 944     }
 945   return true;
 946 }
 947
 948 always_inline uword
 949 ip6_reassembly_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 950                        vlib_frame_t * frame, bool is_feature,
 951                        bool is_custom_app)
 952 {
 953   u32 *from = vlib_frame_vector_args (frame);
 954   u32 n_left_from, n_left_to_next, *to_next, next_index;
 955   ip6_reass_main_t *rm = &ip6_reass_main;
 956   ip6_reass_per_thread_t *rt = &rm->per_thread_data[vm->thread_index];
 957   clib_spinlock_lock (&rt->lock);
 958
 959   n_left_from = frame->n_vectors;
 960   next_index = node->cached_next_index;
 961   while (n_left_from > 0)
 962     {
 963       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 964
 965       while (n_left_from > 0 && n_left_to_next > 0)
 966         {
 967           u32 bi0;
 968           vlib_buffer_t *b0;
 969           u32 next0 = IP6_REASSEMBLY_NEXT_DROP;
 970           u32 error0 = IP6_ERROR_NONE;
 971           u32 icmp_bi = ~0;
 972
 973           bi0 = from[0];
 974           b0 = vlib_get_buffer (vm, bi0);
 975
 976           ip6_header_t *ip0 = vlib_buffer_get_current (b0);
 977           ip6_frag_hdr_t *frag_hdr = NULL;
 978           ip6_ext_header_t *prev_hdr;
 979           if (ip6_ext_hdr (ip0->protocol))
 980             {
 981               ip6_ext_header_find_t (ip0, prev_hdr, frag_hdr,
 982                                      IP_PROTOCOL_IPV6_FRAGMENTATION);
 983             }
 984           if (!frag_hdr)
 985             {
 986               // this is a regular packet - no fragmentation
 987               next0 = IP6_REASSEMBLY_NEXT_INPUT;
 988               goto skip_reass;
 989             }
 990           if (0 == ip6_frag_hdr_offset (frag_hdr))
 991             {
 992               // first fragment - verify upper-layer is present
 993               if (!ip6_reass_verify_upper_layer_present (node, b0, frag_hdr))
 994                 {
 995                   next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
 996                   goto skip_reass;
 997                 }
 998             }
 999           if (!ip6_reass_verify_fragment_multiple_8 (vm, node, b0, frag_hdr)
1000               || !ip6_reass_verify_packet_size_lt_64k (vm, node, b0,
1001                                                        frag_hdr))
1002             {
1003               next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
1004               goto skip_reass;
1005             }
1006           vnet_buffer (b0)->ip.reass.ip6_frag_hdr_offset =
1007             (u8 *) frag_hdr - (u8 *) ip0;
1008
1009           ip6_reass_kv_t kv;
1010           u8 do_handoff = 0;
1011
1012           kv.k.as_u64[0] = ip0->src_address.as_u64[0];
1013           kv.k.as_u64[1] = ip0->src_address.as_u64[1];
1014           kv.k.as_u64[2] = ip0->dst_address.as_u64[0];
1015           kv.k.as_u64[3] = ip0->dst_address.as_u64[1];
1016           kv.k.as_u64[4] =
1017             ((u64) vec_elt (ip6_main.fib_index_by_sw_if_index,
1018                             vnet_buffer (b0)->sw_if_index[VLIB_RX])) << 32 |
1019             (u64) frag_hdr->identification;
1020           kv.k.as_u64[5] = ip0->protocol;
1021
1022           ip6_reass_t *reass =
1023             ip6_reass_find_or_create (vm, node, rm, rt, &kv, &icmp_bi,
1024                                       &do_handoff);
1025
1026           if (PREDICT_FALSE (do_handoff))
1027             {
1028               next0 = IP6_REASSEMBLY_NEXT_HANDOFF;
1029               if (is_feature)
1030                 vnet_buffer (b0)->ip.reass.owner_feature_thread_index =
1031                   kv.v.thread_index;
1032               else
1033                 vnet_buffer (b0)->ip.reass.owner_thread_index =
1034                   kv.v.thread_index;
1035             }
1036           else if (reass)
1037             {
1038               switch (ip6_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
1039                                         &error0, frag_hdr, is_custom_app))
1040                 {
1041                 case IP6_REASS_RC_OK:
1042                   /* nothing to do here */
1043                   break;
1044                 case IP6_REASS_RC_TOO_MANY_FRAGMENTS:
1045                   vlib_node_increment_counter (vm, node->node_index,
1046                                                IP6_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
1047                                                1);
1048                   ip6_reass_drop_all (vm, node, rm, reass);
1049                   ip6_reass_free (rm, rt, reass);
1050                   goto next_packet;
1051                   break;
1052                 case IP6_REASS_RC_NO_BUF:
1053                   vlib_node_increment_counter (vm, node->node_index,
1054                                                IP6_ERROR_REASS_NO_BUF, 1);
1055                   ip6_reass_drop_all (vm, node, rm, reass);
1056                   ip6_reass_free (rm, rt, reass);
1057                   goto next_packet;
1058                   break;
1059                 case IP6_REASS_RC_INTERNAL_ERROR:
1060                   /* drop everything and start with a clean slate */
1061                   vlib_node_increment_counter (vm, node->node_index,
1062                                                IP6_ERROR_REASS_INTERNAL_ERROR,
1063                                                1);
1064                   ip6_reass_drop_all (vm, node, rm, reass);
1065                   ip6_reass_free (rm, rt, reass);
1066                   goto next_packet;
1067                   break;
1068                 }
1069             }
1070           else
1071             {
1072               if (is_feature)
1073                 {
1074                   next0 = IP6_REASSEMBLY_NEXT_DROP;
1075                 }
1076               else
1077                 {
1078                   vnet_buffer_opaque_t *fvnb = vnet_buffer (b0);
1079                   next0 = fvnb->ip.reass.error_next_index;
1080                 }
1081               error0 = IP6_ERROR_REASS_LIMIT_REACHED;
1082             }
1083
1084           b0->error = node->errors[error0];
1085
1086           if (~0 != bi0)
1087             {
1088             skip_reass:
1089               to_next[0] = bi0;
1090               to_next += 1;
1091               n_left_to_next -= 1;
1092               if (is_feature && IP6_ERROR_NONE == error0)
1093                 {
1094                   b0 = vlib_get_buffer (vm, bi0);
1095                   vnet_feature_next (&next0, b0);
1096                 }
1097               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1098                                                n_left_to_next, bi0, next0);
1099             }
1100
1101           if (~0 != icmp_bi)
1102             {
1103               next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
1104               to_next[0] = icmp_bi;
1105               to_next += 1;
1106               n_left_to_next -= 1;
1107               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1108                                                n_left_to_next, icmp_bi,
1109                                                next0);
1110             }
1111         next_packet:
1112           from += 1;
1113           n_left_from -= 1;
1114         }
1115
1116       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1117     }
1118
1119   clib_spinlock_unlock (&rt->lock);
1120   return frame->n_vectors;
1121 }
1122
1123 static char *ip6_reassembly_error_strings[] = {
1124 #define _(sym, string) string,
1125   foreach_ip6_error
1126 #undef _
1127 };
1128
1129 VLIB_NODE_FN (ip6_reass_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
1130                                vlib_frame_t * frame)
1131 {
1132   return ip6_reassembly_inline (vm, node, frame, false /* is_feature */ ,
1133                                 false /* is_custom_app */ );
1134 }
1135
1136 /* *INDENT-OFF* */
1137 VLIB_REGISTER_NODE (ip6_reass_node) = {
1138     .name = "ip6-reassembly",
1139     .vector_size = sizeof (u32),
1140     .format_trace = format_ip6_reass_trace,
1141     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1142     .error_strings = ip6_reassembly_error_strings,
1143     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1144     .next_nodes =
1145         {
1146                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1147                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1148                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1149                 [IP6_REASSEMBLY_NEXT_HANDOFF] = "ip6-reassembly-handoff",
1150         },
1151 };
1152 /* *INDENT-ON* */
1153
1154 VLIB_NODE_FN (ip6_reass_node_feature) (vlib_main_t * vm,
1155                                        vlib_node_runtime_t * node,
1156                                        vlib_frame_t * frame)
1157 {
1158   return ip6_reassembly_inline (vm, node, frame, true /* is_feature */ ,
1159                                 false /* is_custom_app */ );
1160 }
1161
1162 /* *INDENT-OFF* */
1163 VLIB_REGISTER_NODE (ip6_reass_node_feature) = {
1164     .name = "ip6-reassembly-feature",
1165     .vector_size = sizeof (u32),
1166     .format_trace = format_ip6_reass_trace,
1167     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1168     .error_strings = ip6_reassembly_error_strings,
1169     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1170     .next_nodes =
1171         {
1172                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1173                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1174                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1175                 [IP6_REASSEMBLY_NEXT_HANDOFF] = "ip6-reass-feature-hoff",
1176         },
1177 };
1178 /* *INDENT-ON* */
1179
1180 /* *INDENT-OFF* */
1181 VNET_FEATURE_INIT (ip6_reassembly_feature, static) = {
1182     .arc_name = "ip6-unicast",
1183     .node_name = "ip6-reassembly-feature",
1184     .runs_before = VNET_FEATURES ("ip6-lookup",
1185                                   "esp6-decrypt",
1186                                   "ah6-decrypt"),
1187     .runs_after = 0,
1188 };
1189 /* *INDENT-ON* */
1190
1191 #ifndef CLIB_MARCH_VARIANT
1192 static u32
1193 ip6_reass_get_nbuckets ()
1194 {
1195   ip6_reass_main_t *rm = &ip6_reass_main;
1196   u32 nbuckets;
1197   u8 i;
1198
1199   nbuckets = (u32) (rm->max_reass_n / IP6_REASS_HT_LOAD_FACTOR);
1200
1201   for (i = 0; i < 31; i++)
1202     if ((1 << i) >= nbuckets)
1203       break;
1204   nbuckets = 1 << i;
1205
1206   return nbuckets;
1207 }
1208 #endif /* CLIB_MARCH_VARIANT */
1209
1210 typedef enum
1211 {
1212   IP6_EVENT_CONFIG_CHANGED = 1,
1213 } ip6_reass_event_t;
1214
1215 #ifndef CLIB_MARCH_VARIANT
1216 typedef struct
1217 {
1218   int failure;
1219   clib_bihash_48_8_t *new_hash;
1220 } ip6_rehash_cb_ctx;
1221
1222 static void
1223 ip6_rehash_cb (clib_bihash_kv_48_8_t * kv, void *_ctx)
1224 {
1225   ip6_rehash_cb_ctx *ctx = _ctx;
1226   if (clib_bihash_add_del_48_8 (ctx->new_hash, kv, 1))
1227     {
1228       ctx->failure = 1;
1229     }
1230 }
1231
1232 static void
1233 ip6_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1234                       u32 max_reassembly_length, u32 expire_walk_interval_ms)
1235 {
1236   ip6_reass_main.timeout_ms = timeout_ms;
1237   ip6_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1238   ip6_reass_main.max_reass_n = max_reassemblies;
1239   ip6_reass_main.max_reass_len = max_reassembly_length;
1240   ip6_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1241 }
1242
1243 vnet_api_error_t
1244 ip6_reass_set (u32 timeout_ms, u32 max_reassemblies,
1245                u32 max_reassembly_length, u32 expire_walk_interval_ms)
1246 {
1247   u32 old_nbuckets = ip6_reass_get_nbuckets ();
1248   ip6_reass_set_params (timeout_ms, max_reassemblies, max_reassembly_length,
1249                         expire_walk_interval_ms);
1250   vlib_process_signal_event (ip6_reass_main.vlib_main,
1251                              ip6_reass_main.ip6_reass_expire_node_idx,
1252                              IP6_EVENT_CONFIG_CHANGED, 0);
1253   u32 new_nbuckets = ip6_reass_get_nbuckets ();
1254   if (ip6_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1255     {
1256       clib_bihash_48_8_t new_hash;
1257       clib_memset (&new_hash, 0, sizeof (new_hash));
1258       ip6_rehash_cb_ctx ctx;
1259       ctx.failure = 0;
1260       ctx.new_hash = &new_hash;
1261       clib_bihash_init_48_8 (&new_hash, "ip6-reass", new_nbuckets,
1262                              new_nbuckets * 1024);
1263       clib_bihash_foreach_key_value_pair_48_8 (&ip6_reass_main.hash,
1264                                                ip6_rehash_cb, &ctx);
1265       if (ctx.failure)
1266         {
1267           clib_bihash_free_48_8 (&new_hash);
1268           return -1;
1269         }
1270       else
1271         {
1272           clib_bihash_free_48_8 (&ip6_reass_main.hash);
1273           clib_memcpy_fast (&ip6_reass_main.hash, &new_hash,
1274                             sizeof (ip6_reass_main.hash));
1275           clib_bihash_copied (&ip6_reass_main.hash, &new_hash);
1276         }
1277     }
1278   return 0;
1279 }
1280
1281 vnet_api_error_t
1282 ip6_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1283                u32 * expire_walk_interval_ms)
1284 {
1285   *timeout_ms = ip6_reass_main.timeout_ms;
1286   *max_reassemblies = ip6_reass_main.max_reass_n;
1287   *expire_walk_interval_ms = ip6_reass_main.expire_walk_interval_ms;
1288   return 0;
1289 }
1290
1291 static clib_error_t *
1292 ip6_reass_init_function (vlib_main_t * vm)
1293 {
1294   ip6_reass_main_t *rm = &ip6_reass_main;
1295   clib_error_t *error = 0;
1296   u32 nbuckets;
1297   vlib_node_t *node;
1298
1299   rm->vlib_main = vm;
1300   rm->vnet_main = vnet_get_main ();
1301
1302   vec_validate (rm->per_thread_data, vlib_num_workers ());
1303   ip6_reass_per_thread_t *rt;
1304   vec_foreach (rt, rm->per_thread_data)
1305   {
1306     clib_spinlock_init (&rt->lock);
1307     pool_alloc (rt->pool, rm->max_reass_n);
1308   }
1309
1310   node = vlib_get_node_by_name (vm, (u8 *) "ip6-reassembly-expire-walk");
1311   ASSERT (node);
1312   rm->ip6_reass_expire_node_idx = node->index;
1313
1314   ip6_reass_set_params (IP6_REASS_TIMEOUT_DEFAULT_MS,
1315                         IP6_REASS_MAX_REASSEMBLIES_DEFAULT,
1316                         IP6_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT,
1317                         IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1318
1319   nbuckets = ip6_reass_get_nbuckets ();
1320   clib_bihash_init_48_8 (&rm->hash, "ip6-reass", nbuckets, nbuckets * 1024);
1321
1322   node = vlib_get_node_by_name (vm, (u8 *) "ip6-drop");
1323   ASSERT (node);
1324   rm->ip6_drop_idx = node->index;
1325   node = vlib_get_node_by_name (vm, (u8 *) "ip6-icmp-error");
1326   ASSERT (node);
1327   rm->ip6_icmp_error_idx = node->index;
1328
1329   if ((error = vlib_call_init_function (vm, ip_main_init)))
1330     return error;
1331   ip6_register_protocol (IP_PROTOCOL_IPV6_FRAGMENTATION,
1332                          ip6_reass_node.index);
1333
1334   rm->fq_index = vlib_frame_queue_main_init (ip6_reass_node.index, 0);
1335   rm->fq_feature_index =
1336     vlib_frame_queue_main_init (ip6_reass_node_feature.index, 0);
1337
1338   return error;
1339 }
1340
1341 VLIB_INIT_FUNCTION (ip6_reass_init_function);
1342 #endif /* CLIB_MARCH_VARIANT */
1343
1344 static uword
1345 ip6_reass_walk_expired (vlib_main_t * vm,
1346                         vlib_node_runtime_t * node, vlib_frame_t * f)
1347 {
1348   ip6_reass_main_t *rm = &ip6_reass_main;
1349   uword event_type, *event_data = 0;
1350
1351   while (true)
1352     {
1353       vlib_process_wait_for_event_or_clock (vm,
1354                                             (f64) rm->expire_walk_interval_ms
1355                                             / (f64) MSEC_PER_SEC);
1356       event_type = vlib_process_get_events (vm, &event_data);
1357
1358       switch (event_type)
1359         {
1360         case ~0:                /* no events => timeout */
1361           /* nothing to do here */
1362           break;
1363         case IP6_EVENT_CONFIG_CHANGED:
1364           break;
1365         default:
1366           clib_warning ("BUG: event type 0x%wx", event_type);
1367           break;
1368         }
1369       f64 now = vlib_time_now (vm);
1370
1371       ip6_reass_t *reass;
1372       int *pool_indexes_to_free = NULL;
1373
1374       uword thread_index = 0;
1375       int index;
1376       const uword nthreads = vlib_num_workers () + 1;
1377       u32 *vec_icmp_bi = NULL;
1378       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1379         {
1380           ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1381           clib_spinlock_lock (&rt->lock);
1382
1383           vec_reset_length (pool_indexes_to_free);
1384           /* *INDENT-OFF* */
1385           pool_foreach_index (index, rt->pool, ({
1386                                 reass = pool_elt_at_index (rt->pool, index);
1387                                 if (now > reass->last_heard + rm->timeout)
1388                                   {
1389                                     vec_add1 (pool_indexes_to_free, index);
1390                                   }
1391                               }));
1392           /* *INDENT-ON* */
1393           int *i;
1394           /* *INDENT-OFF* */
1395           vec_foreach (i, pool_indexes_to_free)
1396           {
1397             ip6_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1398             u32 icmp_bi = ~0;
1399             ip6_reass_on_timeout (vm, node, rm, reass, &icmp_bi);
1400             if (~0 != icmp_bi)
1401               vec_add1 (vec_icmp_bi, icmp_bi);
1402
1403             ip6_reass_free (rm, rt, reass);
1404           }
1405           /* *INDENT-ON* */
1406
1407           clib_spinlock_unlock (&rt->lock);
1408         }
1409
1410       while (vec_len (vec_icmp_bi) > 0)
1411         {
1412           vlib_frame_t *f =
1413             vlib_get_frame_to_node (vm, rm->ip6_icmp_error_idx);
1414           u32 *to_next = vlib_frame_vector_args (f);
1415           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1416           int trace_frame = 0;
1417           while (vec_len (vec_icmp_bi) > 0 && n_left_to_next > 0)
1418             {
1419               u32 bi = vec_pop (vec_icmp_bi);
1420               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1421               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1422                 trace_frame = 1;
1423               b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
1424               to_next[0] = bi;
1425               ++f->n_vectors;
1426               to_next += 1;
1427               n_left_to_next -= 1;
1428             }
1429           f->frame_flags |= (trace_frame * VLIB_FRAME_TRACE);
1430           vlib_put_frame_to_node (vm, rm->ip6_icmp_error_idx, f);
1431         }
1432
1433       vec_free (pool_indexes_to_free);
1434       vec_free (vec_icmp_bi);
1435       if (event_data)
1436         {
1437           _vec_len (event_data) = 0;
1438         }
1439     }
1440
1441   return 0;
1442 }
1443
1444 /* *INDENT-OFF* */
1445 VLIB_REGISTER_NODE (ip6_reass_expire_node, static) = {
1446     .function = ip6_reass_walk_expired,
1447     .format_trace = format_ip6_reass_trace,
1448     .type = VLIB_NODE_TYPE_PROCESS,
1449     .name = "ip6-reassembly-expire-walk",
1450
1451     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1452     .error_strings = ip6_reassembly_error_strings,
1453
1454 };
1455 /* *INDENT-ON* */
1456
1457 static u8 *
1458 format_ip6_reass_key (u8 * s, va_list * args)
1459 {
1460   ip6_reass_key_t *key = va_arg (*args, ip6_reass_key_t *);
1461   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1462               key->xx_id, format_ip6_address, &key->src, format_ip6_address,
1463               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1464   return s;
1465 }
1466
1467 static u8 *
1468 format_ip6_reass (u8 * s, va_list * args)
1469 {
1470   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1471   ip6_reass_t *reass = va_arg (*args, ip6_reass_t *);
1472
1473   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1474               "last_packet_octet: %u, trace_op_counter: %u\n",
1475               reass->id, format_ip6_reass_key, &reass->key, reass->first_bi,
1476               reass->data_len, reass->last_packet_octet,
1477               reass->trace_op_counter);
1478   u32 bi = reass->first_bi;
1479   u32 counter = 0;
1480   while (~0 != bi)
1481     {
1482       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1483       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1484       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1485                   "fragment[%u, %u]\n",
1486                   counter, vnb->ip.reass.range_first,
1487                   vnb->ip.reass.range_last, bi,
1488                   ip6_reass_buffer_get_data_offset (b),
1489                   ip6_reass_buffer_get_data_len (b),
1490                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1491       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1492         {
1493           bi = b->next_buffer;
1494         }
1495       else
1496         {
1497           bi = ~0;
1498         }
1499     }
1500   return s;
1501 }
1502
1503 static clib_error_t *
1504 show_ip6_reass (vlib_main_t * vm, unformat_input_t * input,
1505                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1506 {
1507   ip6_reass_main_t *rm = &ip6_reass_main;
1508
1509   vlib_cli_output (vm, "---------------------");
1510   vlib_cli_output (vm, "IP6 reassembly status");
1511   vlib_cli_output (vm, "---------------------");
1512   bool details = false;
1513   if (unformat (input, "details"))
1514     {
1515       details = true;
1516     }
1517
1518   u32 sum_reass_n = 0;
1519   u64 sum_buffers_n = 0;
1520   ip6_reass_t *reass;
1521   uword thread_index;
1522   const uword nthreads = vlib_num_workers () + 1;
1523   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1524     {
1525       ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1526       clib_spinlock_lock (&rt->lock);
1527       if (details)
1528         {
1529           /* *INDENT-OFF* */
1530           pool_foreach (reass, rt->pool, {
1531             vlib_cli_output (vm, "%U", format_ip6_reass, vm, reass);
1532           });
1533           /* *INDENT-ON* */
1534         }
1535       sum_reass_n += rt->reass_n;
1536       clib_spinlock_unlock (&rt->lock);
1537     }
1538   vlib_cli_output (vm, "---------------------");
1539   vlib_cli_output (vm, "Current IP6 reassemblies count: %lu\n",
1540                    (long unsigned) sum_reass_n);
1541   vlib_cli_output (vm, "Maximum configured concurrent IP6 reassemblies per "
1542                    "worker-thread: %lu\n", (long unsigned) rm->max_reass_n);
1543   vlib_cli_output (vm, "Buffers in use: %lu\n",
1544                    (long unsigned) sum_buffers_n);
1545   return 0;
1546 }
1547
1548 /* *INDENT-OFF* */
1549 VLIB_CLI_COMMAND (show_ip6_reassembly_cmd, static) = {
1550     .path = "show ip6-reassembly",
1551     .short_help = "show ip6-reassembly [details]",
1552     .function = show_ip6_reass,
1553 };
1554 /* *INDENT-ON* */
1555
1556 #ifndef CLIB_MARCH_VARIANT
1557 vnet_api_error_t
1558 ip6_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1559 {
1560   return vnet_feature_enable_disable ("ip6-unicast", "ip6-reassembly-feature",
1561                                       sw_if_index, enable_disable, 0, 0);
1562 }
1563 #endif /* CLIB_MARCH_VARIANT */
1564
1565 #define foreach_ip6_reassembly_handoff_error                       \
1566 _(CONGESTION_DROP, "congestion drop")
1567
1568
1569 typedef enum
1570 {
1571 #define _(sym,str) IP6_REASSEMBLY_HANDOFF_ERROR_##sym,
1572   foreach_ip6_reassembly_handoff_error
1573 #undef _
1574     IP6_REASSEMBLY_HANDOFF_N_ERROR,
1575 } ip6_reassembly_handoff_error_t;
1576
1577 static char *ip6_reassembly_handoff_error_strings[] = {
1578 #define _(sym,string) string,
1579   foreach_ip6_reassembly_handoff_error
1580 #undef _
1581 };
1582
1583 typedef struct
1584 {
1585   u32 next_worker_index;
1586 } ip6_reassembly_handoff_trace_t;
1587
1588 static u8 *
1589 format_ip6_reassembly_handoff_trace (u8 * s, va_list * args)
1590 {
1591   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1592   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1593   ip6_reassembly_handoff_trace_t *t =
1594     va_arg (*args, ip6_reassembly_handoff_trace_t *);
1595
1596   s =
1597     format (s, "ip6-reassembly-handoff: next-worker %d",
1598             t->next_worker_index);
1599
1600   return s;
1601 }
1602
1603 always_inline uword
1604 ip6_reassembly_handoff_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1605                                vlib_frame_t * frame, bool is_feature)
1606 {
1607   ip6_reass_main_t *rm = &ip6_reass_main;
1608
1609   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
1610   u32 n_enq, n_left_from, *from;
1611   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
1612   u32 fq_index;
1613
1614   from = vlib_frame_vector_args (frame);
1615   n_left_from = frame->n_vectors;
1616   vlib_get_buffers (vm, from, bufs, n_left_from);
1617
1618   b = bufs;
1619   ti = thread_indices;
1620
1621   fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index;
1622
1623   while (n_left_from > 0)
1624     {
1625       ti[0] =
1626         (is_feature) ? vnet_buffer (b[0])->ip.
1627         reass.owner_feature_thread_index : vnet_buffer (b[0])->ip.
1628         reass.owner_thread_index;
1629
1630       if (PREDICT_FALSE
1631           ((node->flags & VLIB_NODE_FLAG_TRACE)
1632            && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
1633         {
1634           ip6_reassembly_handoff_trace_t *t =
1635             vlib_add_trace (vm, node, b[0], sizeof (*t));
1636           t->next_worker_index = ti[0];
1637         }
1638
1639       n_left_from -= 1;
1640       ti += 1;
1641       b += 1;
1642     }
1643   n_enq =
1644     vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
1645                                    frame->n_vectors, 1);
1646
1647   if (n_enq < frame->n_vectors)
1648     vlib_node_increment_counter (vm, node->node_index,
1649                                  IP6_REASSEMBLY_HANDOFF_ERROR_CONGESTION_DROP,
1650                                  frame->n_vectors - n_enq);
1651   return frame->n_vectors;
1652 }
1653
1654 VLIB_NODE_FN (ip6_reassembly_handoff_node) (vlib_main_t * vm,
1655                                             vlib_node_runtime_t * node,
1656                                             vlib_frame_t * frame)
1657 {
1658   return ip6_reassembly_handoff_inline (vm, node, frame,
1659                                         false /* is_feature */ );
1660 }
1661
1662 /* *INDENT-OFF* */
1663 VLIB_REGISTER_NODE (ip6_reassembly_handoff_node) = {
1664   .name = "ip6-reassembly-handoff",
1665   .vector_size = sizeof (u32),
1666   .n_errors = ARRAY_LEN(ip6_reassembly_handoff_error_strings),
1667   .error_strings = ip6_reassembly_handoff_error_strings,
1668   .format_trace = format_ip6_reassembly_handoff_trace,
1669
1670   .n_next_nodes = 1,
1671
1672   .next_nodes = {
1673     [0] = "error-drop",
1674   },
1675 };
1676
1677
1678 VLIB_NODE_FN (ip6_reassembly_feature_handoff_node) (vlib_main_t * vm,
1679                                vlib_node_runtime_t * node, vlib_frame_t * frame)
1680 {
1681   return ip6_reassembly_handoff_inline (vm, node, frame, true /* is_feature */ );
1682 }
1683
1684
1685 /* *INDENT-OFF* */
1686 VLIB_REGISTER_NODE (ip6_reassembly_feature_handoff_node) = {
1687   .name = "ip6-reass-feature-hoff",
1688   .vector_size = sizeof (u32),
1689   .n_errors = ARRAY_LEN(ip6_reassembly_handoff_error_strings),
1690   .error_strings = ip6_reassembly_handoff_error_strings,
1691   .format_trace = format_ip6_reassembly_handoff_trace,
1692
1693   .n_next_nodes = 1,
1694
1695   .next_nodes = {
1696     [0] = "error-drop",
1697   },
1698 };
1699 /* *INDENT-ON* */
1700
1701 /*
1702  * fd.io coding-style-patch-verification: ON
1703  *
1704  * Local Variables:
1705  * eval: (c-set-style "gnu")
1706  * End:
1707  */