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 non-feature node
 114   u32 next_index;
 115   // error next index - used by non-feature node
 116   u32 error_next_index;
 117   // is_feature flag stored for non-inline code use
 118   bool is_feature;
 119   // minimum fragment length for this reassembly - used to estimate MTU
 120   u16 min_fragment_length;
 121   // number of fragments for this reassembly
 122   u32 fragments_n;
 123 } ip6_reass_t;
 124
 125 typedef struct
 126 {
 127   ip6_reass_t *pool;
 128   u32 reass_n;
 129   u32 id_counter;
 130   clib_spinlock_t lock;
 131 } ip6_reass_per_thread_t;
 132
 133 typedef struct
 134 {
 135   // IPv6 config
 136   u32 timeout_ms;
 137   f64 timeout;
 138   u32 expire_walk_interval_ms;
 139   // maximum number of fragments in one reassembly
 140   u32 max_reass_len;
 141   // maximum number of reassemblies
 142   u32 max_reass_n;
 143
 144   // IPv6 runtime
 145   clib_bihash_48_8_t hash;
 146
 147   // per-thread data
 148   ip6_reass_per_thread_t *per_thread_data;
 149
 150   // convenience
 151   vlib_main_t *vlib_main;
 152   vnet_main_t *vnet_main;
 153
 154   // node index of ip6-drop node
 155   u32 ip6_drop_idx;
 156   u32 ip6_icmp_error_idx;
 157   u32 ip6_reass_expire_node_idx;
 158
 159   /** Worker handoff */
 160   u32 fq_index;
 161   u32 fq_feature_index;
 162
 163 } ip6_reass_main_t;
 164
 165 extern ip6_reass_main_t ip6_reass_main;
 166
 167 #ifndef CLIB_MARCH_VARIANT
 168 ip6_reass_main_t ip6_reass_main;
 169 #endif /* CLIB_MARCH_VARIANT */
 170
 171 typedef enum
 172 {
 173   IP6_REASSEMBLY_NEXT_INPUT,
 174   IP6_REASSEMBLY_NEXT_DROP,
 175   IP6_REASSEMBLY_NEXT_ICMP_ERROR,
 176   IP6_REASSEMBLY_NEXT_HANDOFF,
 177   IP6_REASSEMBLY_N_NEXT,
 178 } ip6_reass_next_t;
 179
 180 typedef enum
 181 {
 182   RANGE_NEW,
 183   RANGE_OVERLAP,
 184   ICMP_ERROR_RT_EXCEEDED,
 185   ICMP_ERROR_FL_TOO_BIG,
 186   ICMP_ERROR_FL_NOT_MULT_8,
 187   FINALIZE,
 188 } ip6_reass_trace_operation_e;
 189
 190 typedef struct
 191 {
 192   u16 range_first;
 193   u16 range_last;
 194   u32 range_bi;
 195   i32 data_offset;
 196   u32 data_len;
 197   u32 first_bi;
 198 } ip6_reass_range_trace_t;
 199
 200 typedef struct
 201 {
 202   ip6_reass_trace_operation_e action;
 203   u32 reass_id;
 204   ip6_reass_range_trace_t trace_range;
 205   u32 size_diff;
 206   u32 op_id;
 207   u32 fragment_first;
 208   u32 fragment_last;
 209   u32 total_data_len;
 210 } ip6_reass_trace_t;
 211
 212 static void
 213 ip6_reass_trace_details (vlib_main_t * vm, u32 bi,
 214                          ip6_reass_range_trace_t * trace)
 215 {
 216   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 217   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 218   trace->range_first = vnb->ip.reass.range_first;
 219   trace->range_last = vnb->ip.reass.range_last;
 220   trace->data_offset = ip6_reass_buffer_get_data_offset (b);
 221   trace->data_len = ip6_reass_buffer_get_data_len (b);
 222   trace->range_bi = bi;
 223 }
 224
 225 static u8 *
 226 format_ip6_reass_range_trace (u8 * s, va_list * args)
 227 {
 228   ip6_reass_range_trace_t *trace = va_arg (*args, ip6_reass_range_trace_t *);
 229   s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
 230               trace->range_last, trace->data_offset, trace->data_len,
 231               trace->range_bi);
 232   return s;
 233 }
 234
 235 static u8 *
 236 format_ip6_reass_trace (u8 * s, va_list * args)
 237 {
 238   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 239   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 240   ip6_reass_trace_t *t = va_arg (*args, ip6_reass_trace_t *);
 241   s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
 242   u32 indent = format_get_indent (s);
 243   s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
 244               t->trace_range.first_bi, t->total_data_len, t->fragment_first,
 245               t->fragment_last);
 246   switch (t->action)
 247     {
 248     case RANGE_NEW:
 249       s = format (s, "\n%Unew %U", format_white_space, indent,
 250                   format_ip6_reass_range_trace, &t->trace_range);
 251       break;
 252     case RANGE_OVERLAP:
 253       s = format (s, "\n%Uoverlap %U", format_white_space, indent,
 254                   format_ip6_reass_range_trace, &t->trace_range);
 255       break;
 256     case ICMP_ERROR_FL_TOO_BIG:
 257       s = format (s, "\n%Uicmp-error - frag_len > 65535 %U",
 258                   format_white_space, indent, format_ip6_reass_range_trace,
 259                   &t->trace_range);
 260       break;
 261     case ICMP_ERROR_FL_NOT_MULT_8:
 262       s = format (s, "\n%Uicmp-error - frag_len mod 8 != 0 %U",
 263                   format_white_space, indent, format_ip6_reass_range_trace,
 264                   &t->trace_range);
 265       break;
 266     case ICMP_ERROR_RT_EXCEEDED:
 267       s = format (s, "\n%Uicmp-error - reassembly time exceeded",
 268                   format_white_space, indent);
 269       break;
 270     case FINALIZE:
 271       s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
 272       break;
 273     }
 274   return s;
 275 }
 276
 277 static void
 278 ip6_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 279                      ip6_reass_main_t * rm, ip6_reass_t * reass,
 280                      u32 bi, ip6_reass_trace_operation_e action,
 281                      u32 size_diff)
 282 {
 283   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 284   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 285   if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
 286     {
 287       // this buffer's trace is gone
 288       b->flags &= ~VLIB_BUFFER_IS_TRACED;
 289       return;
 290     }
 291   ip6_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 292   t->reass_id = reass->id;
 293   t->action = action;
 294   ip6_reass_trace_details (vm, bi, &t->trace_range);
 295   t->size_diff = size_diff;
 296   t->op_id = reass->trace_op_counter;
 297   ++reass->trace_op_counter;
 298   t->fragment_first = vnb->ip.reass.fragment_first;
 299   t->fragment_last = vnb->ip.reass.fragment_last;
 300   t->trace_range.first_bi = reass->first_bi;
 301   t->total_data_len = reass->data_len;
 302 #if 0
 303   static u8 *s = NULL;
 304   s = format (s, "%U", format_ip6_reass_trace, NULL, NULL, t);
 305   printf ("%.*s\n", vec_len (s), s);
 306   fflush (stdout);
 307   vec_reset_length (s);
 308 #endif
 309 }
 310
 311 always_inline void
 312 ip6_reass_free (ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 313                 ip6_reass_t * reass)
 314 {
 315   clib_bihash_kv_48_8_t kv;
 316   kv.key[0] = reass->key.as_u64[0];
 317   kv.key[1] = reass->key.as_u64[1];
 318   kv.key[2] = reass->key.as_u64[2];
 319   kv.key[3] = reass->key.as_u64[3];
 320   kv.key[4] = reass->key.as_u64[4];
 321   kv.key[5] = reass->key.as_u64[5];
 322   clib_bihash_add_del_48_8 (&rm->hash, &kv, 0);
 323   pool_put (rt->pool, reass);
 324   --rt->reass_n;
 325 }
 326
 327 always_inline void
 328 ip6_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
 329                     ip6_reass_main_t * rm, ip6_reass_t * reass,
 330                     bool is_feature)
 331 {
 332   u32 range_bi = reass->first_bi;
 333   vlib_buffer_t *range_b;
 334   vnet_buffer_opaque_t *range_vnb;
 335   u32 *to_free = NULL;
 336   while (~0 != range_bi)
 337     {
 338       range_b = vlib_get_buffer (vm, range_bi);
 339       range_vnb = vnet_buffer (range_b);
 340       u32 bi = range_bi;
 341       while (~0 != bi)
 342         {
 343           vec_add1 (to_free, bi);
 344           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 345           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 346             {
 347               bi = b->next_buffer;
 348               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 349             }
 350           else
 351             {
 352               bi = ~0;
 353             }
 354         }
 355       range_bi = range_vnb->ip.reass.next_range_bi;
 356     }
 357   /* send to next_error_index */
 358   if (!(is_feature))
 359     {
 360       u32 n_left_to_next, *to_next, next_index;
 361
 362       next_index = reass->error_next_index;
 363       u32 bi = ~0;
 364
 365       while (vec_len (to_free) > 0)
 366         {
 367           vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 368
 369           while (vec_len (to_free) > 0 && n_left_to_next > 0)
 370             {
 371               bi = vec_pop (to_free);
 372
 373               if (~0 != bi)
 374                 {
 375                   to_next[0] = bi;
 376                   to_next += 1;
 377                   n_left_to_next -= 1;
 378                   vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 379                                                    to_next, n_left_to_next,
 380                                                    bi, next_index);
 381                 }
 382             }
 383           vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 384         }
 385     }
 386   else
 387     {
 388       vlib_buffer_free (vm, to_free, vec_len (to_free));
 389     }
 390   vec_free (to_free);
 391 }
 392
 393 always_inline void
 394 ip6_reass_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * node,
 395                       ip6_reass_main_t * rm, ip6_reass_t * reass,
 396                       u32 * icmp_bi, bool is_feature)
 397 {
 398   if (~0 == reass->first_bi)
 399     {
 400       return;
 401     }
 402   if (is_feature)
 403     {
 404       vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
 405       if (0 == vnet_buffer (b)->ip.reass.fragment_first)
 406         {
 407           *icmp_bi = reass->first_bi;
 408           if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
 409             {
 410               ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi,
 411                                    ICMP_ERROR_RT_EXCEEDED, 0);
 412             }
 413           // fragment with offset zero received - send icmp message back
 414           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 415             {
 416               // separate first buffer from chain and steer it towards icmp node
 417               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 418               reass->first_bi = b->next_buffer;
 419             }
 420           else
 421             {
 422               reass->first_bi = vnet_buffer (b)->ip.reass.next_range_bi;
 423             }
 424           icmp6_error_set_vnet_buffer (b, ICMP6_time_exceeded,
 425                                        ICMP6_time_exceeded_fragment_reassembly_time_exceeded,
 426                                        0);
 427         }
 428     }
 429   ip6_reass_drop_all (vm, node, rm, reass, is_feature);
 430 }
 431
 432 always_inline ip6_reass_t *
 433 ip6_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 434                           ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 435                           ip6_reass_kv_t * kv, u32 * icmp_bi, u8 * do_handoff,
 436                           bool is_feature)
 437 {
 438   ip6_reass_t *reass = NULL;
 439   f64 now = vlib_time_now (rm->vlib_main);
 440
 441   if (!clib_bihash_search_48_8
 442       (&rm->hash, (clib_bihash_kv_48_8_t *) kv, (clib_bihash_kv_48_8_t *) kv))
 443     {
 444       if (vm->thread_index != kv->v.thread_index)
 445         {
 446           *do_handoff = 1;
 447           return NULL;
 448         }
 449       reass = pool_elt_at_index (rt->pool, kv->v.reass_index);
 450
 451       if (now > reass->last_heard + rm->timeout)
 452         {
 453           ip6_reass_on_timeout (vm, node, rm, reass, icmp_bi, is_feature);
 454           ip6_reass_free (rm, rt, reass);
 455           reass = NULL;
 456         }
 457     }
 458
 459   if (reass)
 460     {
 461       reass->last_heard = now;
 462       return reass;
 463     }
 464
 465   if (rt->reass_n >= rm->max_reass_n)
 466     {
 467       reass = NULL;
 468       return reass;
 469     }
 470   else
 471     {
 472       pool_get (rt->pool, reass);
 473       clib_memset (reass, 0, sizeof (*reass));
 474       reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter;
 475       ++rt->id_counter;
 476       reass->first_bi = ~0;
 477       reass->last_packet_octet = ~0;
 478       reass->data_len = 0;
 479       reass->is_feature = is_feature;
 480       ++rt->reass_n;
 481     }
 482
 483   reass->key.as_u64[0] = ((clib_bihash_kv_48_8_t *) kv)->key[0];
 484   reass->key.as_u64[1] = ((clib_bihash_kv_48_8_t *) kv)->key[1];
 485   reass->key.as_u64[2] = ((clib_bihash_kv_48_8_t *) kv)->key[2];
 486   reass->key.as_u64[3] = ((clib_bihash_kv_48_8_t *) kv)->key[3];
 487   reass->key.as_u64[4] = ((clib_bihash_kv_48_8_t *) kv)->key[4];
 488   reass->key.as_u64[5] = ((clib_bihash_kv_48_8_t *) kv)->key[5];
 489   kv->v.reass_index = (reass - rt->pool);
 490   kv->v.thread_index = vm->thread_index;
 491   reass->last_heard = now;
 492
 493   if (clib_bihash_add_del_48_8 (&rm->hash, (clib_bihash_kv_48_8_t *) kv, 1))
 494     {
 495       ip6_reass_free (rm, rt, reass);
 496       reass = NULL;
 497     }
 498
 499   return reass;
 500 }
 501
 502 always_inline ip6_reass_rc_t
 503 ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 504                     ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 505                     ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 506                     bool is_feature)
 507 {
 508   *bi0 = reass->first_bi;
 509   *error0 = IP6_ERROR_NONE;
 510   ip6_frag_hdr_t *frag_hdr;
 511   vlib_buffer_t *last_b = NULL;
 512   u32 sub_chain_bi = reass->first_bi;
 513   u32 total_length = 0;
 514   u32 buf_cnt = 0;
 515   u32 dropped_cnt = 0;
 516   u32 *vec_drop_compress = NULL;
 517   ip6_reass_rc_t rv = IP6_REASS_RC_OK;
 518   do
 519     {
 520       u32 tmp_bi = sub_chain_bi;
 521       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 522       vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
 523       if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 524           !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 525         {
 526           rv = IP6_REASS_RC_INTERNAL_ERROR;
 527           goto free_buffers_and_return;
 528         }
 529
 530       u32 data_len = ip6_reass_buffer_get_data_len (tmp);
 531       u32 trim_front = vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 532         sizeof (*frag_hdr) + ip6_reass_buffer_get_data_offset (tmp);
 533       u32 trim_end =
 534         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 535       if (tmp_bi == reass->first_bi)
 536         {
 537           /* first buffer - keep ip6 header */
 538           if (0 != ip6_reass_buffer_get_data_offset (tmp))
 539             {
 540               rv = IP6_REASS_RC_INTERNAL_ERROR;
 541               goto free_buffers_and_return;
 542             }
 543           trim_front = 0;
 544           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 545             (vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 546              sizeof (*frag_hdr));
 547           if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
 548             {
 549               rv = IP6_REASS_RC_INTERNAL_ERROR;
 550               goto free_buffers_and_return;
 551             }
 552         }
 553       u32 keep_data =
 554         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 555       while (1)
 556         {
 557           ++buf_cnt;
 558           if (trim_front)
 559             {
 560               if (trim_front > tmp->current_length)
 561                 {
 562                   /* drop whole buffer */
 563                   vec_add1 (vec_drop_compress, tmp_bi);
 564                   trim_front -= tmp->current_length;
 565                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 566                     {
 567                       rv = IP6_REASS_RC_INTERNAL_ERROR;
 568                       goto free_buffers_and_return;
 569                     }
 570                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 571                   tmp_bi = tmp->next_buffer;
 572                   tmp = vlib_get_buffer (vm, tmp_bi);
 573                   continue;
 574                 }
 575               else
 576                 {
 577                   vlib_buffer_advance (tmp, trim_front);
 578                   trim_front = 0;
 579                 }
 580             }
 581           if (keep_data)
 582             {
 583               if (last_b)
 584                 {
 585                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 586                   last_b->next_buffer = tmp_bi;
 587                 }
 588               last_b = tmp;
 589               if (keep_data <= tmp->current_length)
 590                 {
 591                   tmp->current_length = keep_data;
 592                   keep_data = 0;
 593                 }
 594               else
 595                 {
 596                   keep_data -= tmp->current_length;
 597                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 598                     {
 599                       rv = IP6_REASS_RC_INTERNAL_ERROR;
 600                       goto free_buffers_and_return;
 601                     }
 602                 }
 603               total_length += tmp->current_length;
 604             }
 605           else
 606             {
 607               vec_add1 (vec_drop_compress, tmp_bi);
 608               if (reass->first_bi == tmp_bi)
 609                 {
 610                   rv = IP6_REASS_RC_INTERNAL_ERROR;
 611                   goto free_buffers_and_return;
 612                 }
 613               ++dropped_cnt;
 614             }
 615           if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 616             {
 617               tmp_bi = tmp->next_buffer;
 618               tmp = vlib_get_buffer (vm, tmp->next_buffer);
 619             }
 620           else
 621             {
 622               break;
 623             }
 624         }
 625       sub_chain_bi =
 626         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 627         reass.next_range_bi;
 628     }
 629   while (~0 != sub_chain_bi);
 630
 631   if (!last_b)
 632     {
 633       rv = IP6_REASS_RC_INTERNAL_ERROR;
 634       goto free_buffers_and_return;
 635     }
 636   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 637   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 638   if (total_length < first_b->current_length)
 639     {
 640       rv = IP6_REASS_RC_INTERNAL_ERROR;
 641       goto free_buffers_and_return;
 642     }
 643   total_length -= first_b->current_length;
 644   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 645   first_b->total_length_not_including_first_buffer = total_length;
 646   // drop fragment header
 647   vnet_buffer_opaque_t *first_b_vnb = vnet_buffer (first_b);
 648   ip6_header_t *ip = vlib_buffer_get_current (first_b);
 649   u16 ip6_frag_hdr_offset = first_b_vnb->ip.reass.ip6_frag_hdr_offset;
 650   ip6_ext_header_t *prev_hdr;
 651   ip6_ext_header_find_t (ip, prev_hdr, frag_hdr,
 652                          IP_PROTOCOL_IPV6_FRAGMENTATION);
 653   if (prev_hdr)
 654     {
 655       prev_hdr->next_hdr = frag_hdr->next_hdr;
 656     }
 657   else
 658     {
 659       ip->protocol = frag_hdr->next_hdr;
 660     }
 661   if (!((u8 *) frag_hdr - (u8 *) ip == ip6_frag_hdr_offset))
 662     {
 663       rv = IP6_REASS_RC_INTERNAL_ERROR;
 664       goto free_buffers_and_return;
 665     }
 666   memmove (frag_hdr, (u8 *) frag_hdr + sizeof (*frag_hdr),
 667            first_b->current_length - ip6_frag_hdr_offset -
 668            sizeof (ip6_frag_hdr_t));
 669   first_b->current_length -= sizeof (*frag_hdr);
 670   ip->payload_length =
 671     clib_host_to_net_u16 (total_length + first_b->current_length -
 672                           sizeof (*ip));
 673   if (!vlib_buffer_chain_linearize (vm, first_b))
 674     {
 675       rv = IP6_REASS_RC_NO_BUF;
 676       goto free_buffers_and_return;
 677     }
 678   first_b->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
 679   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 680     {
 681       ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 682 #if 0
 683       // following code does a hexdump of packet fragments to stdout ...
 684       do
 685         {
 686           u32 bi = reass->first_bi;
 687           u8 *s = NULL;
 688           while (~0 != bi)
 689             {
 690               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 691               s = format (s, "%u: %U\n", bi, format_hexdump,
 692                           vlib_buffer_get_current (b), b->current_length);
 693               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 694                 {
 695                   bi = b->next_buffer;
 696                 }
 697               else
 698                 {
 699                   break;
 700                 }
 701             }
 702           printf ("%.*s\n", vec_len (s), s);
 703           fflush (stdout);
 704           vec_free (s);
 705         }
 706       while (0);
 707 #endif
 708     }
 709   if (is_feature)
 710     {
 711       *next0 = IP6_REASSEMBLY_NEXT_INPUT;
 712     }
 713   else
 714     {
 715       *next0 = reass->next_index;
 716     }
 717   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 718   ip6_reass_free (rm, rt, reass);
 719   reass = NULL;
 720 free_buffers_and_return:
 721   vlib_buffer_free (vm, vec_drop_compress, vec_len (vec_drop_compress));
 722   vec_free (vec_drop_compress);
 723   return rv;
 724 }
 725
 726 always_inline void
 727 ip6_reass_insert_range_in_chain (vlib_main_t * vm, ip6_reass_main_t * rm,
 728                                  ip6_reass_per_thread_t * rt,
 729                                  ip6_reass_t * reass, u32 prev_range_bi,
 730                                  u32 new_next_bi)
 731 {
 732
 733   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 734   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 735   if (~0 != prev_range_bi)
 736     {
 737       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 738       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 739       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 740       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 741     }
 742   else
 743     {
 744       if (~0 != reass->first_bi)
 745         {
 746           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 747         }
 748       reass->first_bi = new_next_bi;
 749     }
 750   reass->data_len += ip6_reass_buffer_get_data_len (new_next_b);
 751 }
 752
 753 always_inline ip6_reass_rc_t
 754 ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 755                   ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 756                   ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 757                   ip6_frag_hdr_t * frag_hdr, bool is_feature)
 758 {
 759   int consumed = 0;
 760   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 761   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 762   reass->next_index = fvnb->ip.reass.next_index;        // store next_index before it's overwritten
 763   reass->error_next_index = fvnb->ip.reass.error_next_index;    // store error_next_index before it is overwritten
 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, is_feature);
 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_feature);
 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,
 956                        vlib_node_runtime_t * node,
 957                        vlib_frame_t * frame, bool is_feature)
 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, is_feature);
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_feature))
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, is_feature);
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, is_feature);
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, is_feature);
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 }
1140
1141 /* *INDENT-OFF* */
1142 VLIB_REGISTER_NODE (ip6_reass_node) = {
1143     .name = "ip6-reassembly",
1144     .vector_size = sizeof (u32),
1145     .format_trace = format_ip6_reass_trace,
1146     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1147     .error_strings = ip6_reassembly_error_strings,
1148     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1149     .next_nodes =
1150         {
1151                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1152                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1153                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1154                 [IP6_REASSEMBLY_NEXT_HANDOFF] = "ip6-reassembly-handoff",
1155         },
1156 };
1157 /* *INDENT-ON* */
1158
1159 VLIB_NODE_FN (ip6_reass_node_feature) (vlib_main_t * vm,
1160                                        vlib_node_runtime_t * node,
1161                                        vlib_frame_t * frame)
1162 {
1163   return ip6_reassembly_inline (vm, node, frame, true /* is_feature */ );
1164 }
1165
1166 /* *INDENT-OFF* */
1167 VLIB_REGISTER_NODE (ip6_reass_node_feature) = {
1168     .name = "ip6-reassembly-feature",
1169     .vector_size = sizeof (u32),
1170     .format_trace = format_ip6_reass_trace,
1171     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1172     .error_strings = ip6_reassembly_error_strings,
1173     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1174     .next_nodes =
1175         {
1176                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1177                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1178                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1179                 [IP6_REASSEMBLY_NEXT_HANDOFF] = "ip6-reass-feature-hoff",
1180         },
1181 };
1182 /* *INDENT-ON* */
1183
1184 /* *INDENT-OFF* */
1185 VNET_FEATURE_INIT (ip6_reassembly_feature, static) = {
1186     .arc_name = "ip6-unicast",
1187     .node_name = "ip6-reassembly-feature",
1188     .runs_before = VNET_FEATURES ("ip6-lookup"),
1189     .runs_after = 0,
1190 };
1191 /* *INDENT-ON* */
1192
1193 #ifndef CLIB_MARCH_VARIANT
1194 static u32
1195 ip6_reass_get_nbuckets ()
1196 {
1197   ip6_reass_main_t *rm = &ip6_reass_main;
1198   u32 nbuckets;
1199   u8 i;
1200
1201   nbuckets = (u32) (rm->max_reass_n / IP6_REASS_HT_LOAD_FACTOR);
1202
1203   for (i = 0; i < 31; i++)
1204     if ((1 << i) >= nbuckets)
1205       break;
1206   nbuckets = 1 << i;
1207
1208   return nbuckets;
1209 }
1210 #endif /* CLIB_MARCH_VARIANT */
1211
1212 typedef enum
1213 {
1214   IP6_EVENT_CONFIG_CHANGED = 1,
1215 } ip6_reass_event_t;
1216
1217 #ifndef CLIB_MARCH_VARIANT
1218 typedef struct
1219 {
1220   int failure;
1221   clib_bihash_48_8_t *new_hash;
1222 } ip6_rehash_cb_ctx;
1223
1224 static void
1225 ip6_rehash_cb (clib_bihash_kv_48_8_t * kv, void *_ctx)
1226 {
1227   ip6_rehash_cb_ctx *ctx = _ctx;
1228   if (clib_bihash_add_del_48_8 (ctx->new_hash, kv, 1))
1229     {
1230       ctx->failure = 1;
1231     }
1232 }
1233
1234 static void
1235 ip6_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1236                       u32 max_reassembly_length, u32 expire_walk_interval_ms)
1237 {
1238   ip6_reass_main.timeout_ms = timeout_ms;
1239   ip6_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1240   ip6_reass_main.max_reass_n = max_reassemblies;
1241   ip6_reass_main.max_reass_len = max_reassembly_length;
1242   ip6_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1243 }
1244
1245 vnet_api_error_t
1246 ip6_reass_set (u32 timeout_ms, u32 max_reassemblies,
1247                u32 max_reassembly_length, u32 expire_walk_interval_ms)
1248 {
1249   u32 old_nbuckets = ip6_reass_get_nbuckets ();
1250   ip6_reass_set_params (timeout_ms, max_reassemblies, max_reassembly_length,
1251                         expire_walk_interval_ms);
1252   vlib_process_signal_event (ip6_reass_main.vlib_main,
1253                              ip6_reass_main.ip6_reass_expire_node_idx,
1254                              IP6_EVENT_CONFIG_CHANGED, 0);
1255   u32 new_nbuckets = ip6_reass_get_nbuckets ();
1256   if (ip6_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1257     {
1258       clib_bihash_48_8_t new_hash;
1259       clib_memset (&new_hash, 0, sizeof (new_hash));
1260       ip6_rehash_cb_ctx ctx;
1261       ctx.failure = 0;
1262       ctx.new_hash = &new_hash;
1263       clib_bihash_init_48_8 (&new_hash, "ip6-reass", new_nbuckets,
1264                              new_nbuckets * 1024);
1265       clib_bihash_foreach_key_value_pair_48_8 (&ip6_reass_main.hash,
1266                                                ip6_rehash_cb, &ctx);
1267       if (ctx.failure)
1268         {
1269           clib_bihash_free_48_8 (&new_hash);
1270           return -1;
1271         }
1272       else
1273         {
1274           clib_bihash_free_48_8 (&ip6_reass_main.hash);
1275           clib_memcpy_fast (&ip6_reass_main.hash, &new_hash,
1276                             sizeof (ip6_reass_main.hash));
1277         }
1278     }
1279   return 0;
1280 }
1281
1282 vnet_api_error_t
1283 ip6_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1284                u32 * expire_walk_interval_ms)
1285 {
1286   *timeout_ms = ip6_reass_main.timeout_ms;
1287   *max_reassemblies = ip6_reass_main.max_reass_n;
1288   *expire_walk_interval_ms = ip6_reass_main.expire_walk_interval_ms;
1289   return 0;
1290 }
1291
1292 static clib_error_t *
1293 ip6_reass_init_function (vlib_main_t * vm)
1294 {
1295   ip6_reass_main_t *rm = &ip6_reass_main;
1296   clib_error_t *error = 0;
1297   u32 nbuckets;
1298   vlib_node_t *node;
1299
1300   rm->vlib_main = vm;
1301   rm->vnet_main = vnet_get_main ();
1302
1303   vec_validate (rm->per_thread_data, vlib_num_workers ());
1304   ip6_reass_per_thread_t *rt;
1305   vec_foreach (rt, rm->per_thread_data)
1306   {
1307     clib_spinlock_init (&rt->lock);
1308     pool_alloc (rt->pool, rm->max_reass_n);
1309   }
1310
1311   node = vlib_get_node_by_name (vm, (u8 *) "ip6-reassembly-expire-walk");
1312   ASSERT (node);
1313   rm->ip6_reass_expire_node_idx = node->index;
1314
1315   ip6_reass_set_params (IP6_REASS_TIMEOUT_DEFAULT_MS,
1316                         IP6_REASS_MAX_REASSEMBLIES_DEFAULT,
1317                         IP6_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT,
1318                         IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1319
1320   nbuckets = ip6_reass_get_nbuckets ();
1321   clib_bihash_init_48_8 (&rm->hash, "ip6-reass", nbuckets, nbuckets * 1024);
1322
1323   node = vlib_get_node_by_name (vm, (u8 *) "ip6-drop");
1324   ASSERT (node);
1325   rm->ip6_drop_idx = node->index;
1326   node = vlib_get_node_by_name (vm, (u8 *) "ip6-icmp-error");
1327   ASSERT (node);
1328   rm->ip6_icmp_error_idx = node->index;
1329
1330   if ((error = vlib_call_init_function (vm, ip_main_init)))
1331     return error;
1332   ip6_register_protocol (IP_PROTOCOL_IPV6_FRAGMENTATION,
1333                          ip6_reass_node.index);
1334
1335   rm->fq_index = vlib_frame_queue_main_init (ip6_reass_node.index, 0);
1336   rm->fq_feature_index =
1337     vlib_frame_queue_main_init (ip6_reass_node_feature.index, 0);
1338
1339   return error;
1340 }
1341
1342 VLIB_INIT_FUNCTION (ip6_reass_init_function);
1343 #endif /* CLIB_MARCH_VARIANT */
1344
1345 static uword
1346 ip6_reass_walk_expired (vlib_main_t * vm,
1347                         vlib_node_runtime_t * node, vlib_frame_t * f)
1348 {
1349   ip6_reass_main_t *rm = &ip6_reass_main;
1350   uword event_type, *event_data = 0;
1351
1352   while (true)
1353     {
1354       vlib_process_wait_for_event_or_clock (vm,
1355                                             (f64) rm->expire_walk_interval_ms
1356                                             / (f64) MSEC_PER_SEC);
1357       event_type = vlib_process_get_events (vm, &event_data);
1358
1359       switch (event_type)
1360         {
1361         case ~0:                /* no events => timeout */
1362           /* nothing to do here */
1363           break;
1364         case IP6_EVENT_CONFIG_CHANGED:
1365           break;
1366         default:
1367           clib_warning ("BUG: event type 0x%wx", event_type);
1368           break;
1369         }
1370       f64 now = vlib_time_now (vm);
1371
1372       ip6_reass_t *reass;
1373       int *pool_indexes_to_free = NULL;
1374
1375       uword thread_index = 0;
1376       int index;
1377       const uword nthreads = vlib_num_workers () + 1;
1378       u32 *vec_icmp_bi = NULL;
1379       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1380         {
1381           ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1382           clib_spinlock_lock (&rt->lock);
1383
1384           vec_reset_length (pool_indexes_to_free);
1385           /* *INDENT-OFF* */
1386           pool_foreach_index (index, rt->pool, ({
1387                                 reass = pool_elt_at_index (rt->pool, index);
1388                                 if (now > reass->last_heard + rm->timeout)
1389                                   {
1390                                     vec_add1 (pool_indexes_to_free, index);
1391                                   }
1392                               }));
1393           /* *INDENT-ON* */
1394           int *i;
1395           /* *INDENT-OFF* */
1396           vec_foreach (i, pool_indexes_to_free)
1397           {
1398             ip6_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1399             u32 icmp_bi = ~0;
1400             vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
1401             if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1402               {
1403                 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1404                                         b->trace_index))
1405                   {
1406                     /* the trace is gone, don't trace this buffer anymore */
1407                     b->flags &= ~VLIB_BUFFER_IS_TRACED;
1408                   }
1409               }
1410             ip6_reass_on_timeout (vm, node, rm, reass, &icmp_bi, reass->is_feature);
1411             if (~0 != icmp_bi)
1412               {
1413                 vec_add1 (vec_icmp_bi, icmp_bi);
1414               }
1415             ip6_reass_free (rm, rt, reass);
1416           }
1417           /* *INDENT-ON* */
1418
1419           clib_spinlock_unlock (&rt->lock);
1420         }
1421
1422       while (vec_len (vec_icmp_bi) > 0)
1423         {
1424           vlib_frame_t *f =
1425             vlib_get_frame_to_node (vm, rm->ip6_icmp_error_idx);
1426           u32 *to_next = vlib_frame_vector_args (f);
1427           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1428           int trace_frame = 0;
1429           while (vec_len (vec_icmp_bi) > 0 && n_left_to_next > 0)
1430             {
1431               u32 bi = vec_pop (vec_icmp_bi);
1432               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1433               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1434                 {
1435                   if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1436                                           b->trace_index))
1437                     {
1438                       /* the trace is gone, don't trace this buffer anymore */
1439                       b->flags &= ~VLIB_BUFFER_IS_TRACED;
1440                     }
1441                   else
1442                     {
1443                       trace_frame = 1;
1444                     }
1445                 }
1446               b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
1447               to_next[0] = bi;
1448               ++f->n_vectors;
1449               to_next += 1;
1450               n_left_to_next -= 1;
1451             }
1452           f->frame_flags |= (trace_frame * VLIB_FRAME_TRACE);
1453           vlib_put_frame_to_node (vm, rm->ip6_icmp_error_idx, f);
1454         }
1455
1456       vec_free (pool_indexes_to_free);
1457       vec_free (vec_icmp_bi);
1458       if (event_data)
1459         {
1460           _vec_len (event_data) = 0;
1461         }
1462     }
1463
1464   return 0;
1465 }
1466
1467 /* *INDENT-OFF* */
1468 VLIB_REGISTER_NODE (ip6_reass_expire_node, static) = {
1469     .function = ip6_reass_walk_expired,
1470     .format_trace = format_ip6_reass_trace,
1471     .type = VLIB_NODE_TYPE_PROCESS,
1472     .name = "ip6-reassembly-expire-walk",
1473
1474     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1475     .error_strings = ip6_reassembly_error_strings,
1476
1477 };
1478 /* *INDENT-ON* */
1479
1480 static u8 *
1481 format_ip6_reass_key (u8 * s, va_list * args)
1482 {
1483   ip6_reass_key_t *key = va_arg (*args, ip6_reass_key_t *);
1484   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1485               key->xx_id, format_ip6_address, &key->src, format_ip6_address,
1486               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1487   return s;
1488 }
1489
1490 static u8 *
1491 format_ip6_reass (u8 * s, va_list * args)
1492 {
1493   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1494   ip6_reass_t *reass = va_arg (*args, ip6_reass_t *);
1495
1496   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1497               "last_packet_octet: %u, trace_op_counter: %u\n",
1498               reass->id, format_ip6_reass_key, &reass->key, reass->first_bi,
1499               reass->data_len, reass->last_packet_octet,
1500               reass->trace_op_counter);
1501   u32 bi = reass->first_bi;
1502   u32 counter = 0;
1503   while (~0 != bi)
1504     {
1505       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1506       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1507       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1508                   "fragment[%u, %u]\n",
1509                   counter, vnb->ip.reass.range_first,
1510                   vnb->ip.reass.range_last, bi,
1511                   ip6_reass_buffer_get_data_offset (b),
1512                   ip6_reass_buffer_get_data_len (b),
1513                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1514       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1515         {
1516           bi = b->next_buffer;
1517         }
1518       else
1519         {
1520           bi = ~0;
1521         }
1522     }
1523   return s;
1524 }
1525
1526 static clib_error_t *
1527 show_ip6_reass (vlib_main_t * vm, unformat_input_t * input,
1528                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1529 {
1530   ip6_reass_main_t *rm = &ip6_reass_main;
1531
1532   vlib_cli_output (vm, "---------------------");
1533   vlib_cli_output (vm, "IP6 reassembly status");
1534   vlib_cli_output (vm, "---------------------");
1535   bool details = false;
1536   if (unformat (input, "details"))
1537     {
1538       details = true;
1539     }
1540
1541   u32 sum_reass_n = 0;
1542   u64 sum_buffers_n = 0;
1543   ip6_reass_t *reass;
1544   uword thread_index;
1545   const uword nthreads = vlib_num_workers () + 1;
1546   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1547     {
1548       ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1549       clib_spinlock_lock (&rt->lock);
1550       if (details)
1551         {
1552           /* *INDENT-OFF* */
1553           pool_foreach (reass, rt->pool, {
1554             vlib_cli_output (vm, "%U", format_ip6_reass, vm, reass);
1555           });
1556           /* *INDENT-ON* */
1557         }
1558       sum_reass_n += rt->reass_n;
1559       clib_spinlock_unlock (&rt->lock);
1560     }
1561   vlib_cli_output (vm, "---------------------");
1562   vlib_cli_output (vm, "Current IP6 reassemblies count: %lu\n",
1563                    (long unsigned) sum_reass_n);
1564   vlib_cli_output (vm, "Maximum configured concurrent IP6 reassemblies per "
1565                    "worker-thread: %lu\n", (long unsigned) rm->max_reass_n);
1566   vlib_cli_output (vm, "Buffers in use: %lu\n",
1567                    (long unsigned) sum_buffers_n);
1568   return 0;
1569 }
1570
1571 /* *INDENT-OFF* */
1572 VLIB_CLI_COMMAND (show_ip6_reassembly_cmd, static) = {
1573     .path = "show ip6-reassembly",
1574     .short_help = "show ip6-reassembly [details]",
1575     .function = show_ip6_reass,
1576 };
1577 /* *INDENT-ON* */
1578
1579 #ifndef CLIB_MARCH_VARIANT
1580 vnet_api_error_t
1581 ip6_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1582 {
1583   return vnet_feature_enable_disable ("ip6-unicast", "ip6-reassembly-feature",
1584                                       sw_if_index, enable_disable, 0, 0);
1585 }
1586 #endif /* CLIB_MARCH_VARIANT */
1587
1588 #define foreach_ip6_reassembly_handoff_error                       \
1589 _(CONGESTION_DROP, "congestion drop")
1590
1591
1592 typedef enum
1593 {
1594 #define _(sym,str) IP6_REASSEMBLY_HANDOFF_ERROR_##sym,
1595   foreach_ip6_reassembly_handoff_error
1596 #undef _
1597     IP6_REASSEMBLY_HANDOFF_N_ERROR,
1598 } ip6_reassembly_handoff_error_t;
1599
1600 static char *ip6_reassembly_handoff_error_strings[] = {
1601 #define _(sym,string) string,
1602   foreach_ip6_reassembly_handoff_error
1603 #undef _
1604 };
1605
1606 typedef struct
1607 {
1608   u32 next_worker_index;
1609 } ip6_reassembly_handoff_trace_t;
1610
1611 static u8 *
1612 format_ip6_reassembly_handoff_trace (u8 * s, va_list * args)
1613 {
1614   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1615   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1616   ip6_reassembly_handoff_trace_t *t =
1617     va_arg (*args, ip6_reassembly_handoff_trace_t *);
1618
1619   s =
1620     format (s, "ip6-reassembly-handoff: next-worker %d",
1621             t->next_worker_index);
1622
1623   return s;
1624 }
1625
1626 always_inline uword
1627 ip6_reassembly_handoff_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1628                                vlib_frame_t * frame, bool is_feature)
1629 {
1630   ip6_reass_main_t *rm = &ip6_reass_main;
1631
1632   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
1633   u32 n_enq, n_left_from, *from;
1634   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
1635   u32 fq_index;
1636
1637   from = vlib_frame_vector_args (frame);
1638   n_left_from = frame->n_vectors;
1639   vlib_get_buffers (vm, from, bufs, n_left_from);
1640
1641   b = bufs;
1642   ti = thread_indices;
1643
1644   fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index;
1645
1646   while (n_left_from > 0)
1647     {
1648       ti[0] =
1649         (is_feature) ? vnet_buffer (b[0])->ip.
1650         reass.owner_feature_thread_index : vnet_buffer (b[0])->ip.
1651         reass.owner_thread_index;
1652
1653       if (PREDICT_FALSE
1654           ((node->flags & VLIB_NODE_FLAG_TRACE)
1655            && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
1656         {
1657           ip6_reassembly_handoff_trace_t *t =
1658             vlib_add_trace (vm, node, b[0], sizeof (*t));
1659           t->next_worker_index = ti[0];
1660         }
1661
1662       n_left_from -= 1;
1663       ti += 1;
1664       b += 1;
1665     }
1666   n_enq =
1667     vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
1668                                    frame->n_vectors, 1);
1669
1670   if (n_enq < frame->n_vectors)
1671     vlib_node_increment_counter (vm, node->node_index,
1672                                  IP6_REASSEMBLY_HANDOFF_ERROR_CONGESTION_DROP,
1673                                  frame->n_vectors - n_enq);
1674   return frame->n_vectors;
1675 }
1676
1677 VLIB_NODE_FN (ip6_reassembly_handoff_node) (vlib_main_t * vm,
1678                                             vlib_node_runtime_t * node,
1679                                             vlib_frame_t * frame)
1680 {
1681   return ip6_reassembly_handoff_inline (vm, node, frame,
1682                                         false /* is_feature */ );
1683 }
1684
1685 /* *INDENT-OFF* */
1686 VLIB_REGISTER_NODE (ip6_reassembly_handoff_node) = {
1687   .name = "ip6-reassembly-handoff",
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
1700
1701 VLIB_NODE_FN (ip6_reassembly_feature_handoff_node) (vlib_main_t * vm,
1702                                vlib_node_runtime_t * node, vlib_frame_t * frame)
1703 {
1704   return ip6_reassembly_handoff_inline (vm, node, frame, true /* is_feature */ );
1705 }
1706
1707
1708 /* *INDENT-OFF* */
1709 VLIB_REGISTER_NODE (ip6_reassembly_feature_handoff_node) = {
1710   .name = "ip6-reass-feature-hoff",
1711   .vector_size = sizeof (u32),
1712   .n_errors = ARRAY_LEN(ip6_reassembly_handoff_error_strings),
1713   .error_strings = ip6_reassembly_handoff_error_strings,
1714   .format_trace = format_ip6_reassembly_handoff_trace,
1715
1716   .n_next_nodes = 1,
1717
1718   .next_nodes = {
1719     [0] = "error-drop",
1720   },
1721 };
1722 /* *INDENT-ON* */
1723
1724 /*
1725  * fd.io coding-style-patch-verification: ON
1726  *
1727  * Local Variables:
1728  * eval: (c-set-style "gnu")
1729  * End:
1730  */