src/vnet/ip/ip6_reassembly.c

   1 /*
   2  * Copyright (c) 2017 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 /**
  17  * @file
  18  * @brief IPv6 Reassembly.
  19  *
  20  * This file contains the source code for IPv6 reassembly.
  21  */
  22
  23 #include <vppinfra/vec.h>
  24 #include <vnet/vnet.h>
  25 #include <vnet/ip/ip.h>
  26 #include <vppinfra/bihash_48_8.h>
  27 #include <vnet/ip/ip6_reassembly.h>
  28
  29 #define MSEC_PER_SEC 1000
  30 #define IP6_REASS_TIMEOUT_DEFAULT_MS 100
  31 #define IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000 // 10 seconds default
  32 #define IP6_REASS_MAX_REASSEMBLIES_DEFAULT 1024
  33 #define IP6_REASS_HT_LOAD_FACTOR (0.75)
  34
  35 static vlib_node_registration_t ip6_reass_node;
  36
  37 typedef struct
  38 {
  39   union
  40   {
  41     struct
  42     {
  43       ip6_address_t src;
  44       ip6_address_t dst;
  45       u32 xx_id;
  46       u32 frag_id;
  47       u8 unused[7];
  48       u8 proto;
  49     };
  50     u64 as_u64[6];
  51   };
  52 } ip6_reass_key_t;
  53
  54 always_inline u32
  55 ip6_reass_buffer_get_data_offset_no_check (vlib_buffer_t * b)
  56 {
  57   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  58   return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
  59 }
  60
  61 always_inline u32
  62 ip6_reass_buffer_get_data_offset (vlib_buffer_t * b)
  63 {
  64   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  65   ASSERT (vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first);
  66   return ip6_reass_buffer_get_data_offset_no_check (b);
  67 }
  68
  69 always_inline u16
  70 ip6_reass_buffer_get_data_len_no_check (vlib_buffer_t * b)
  71 {
  72   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  73   return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
  74     (vnb->ip.reass.fragment_first + ip6_reass_buffer_get_data_offset (b)) + 1;
  75 }
  76
  77 always_inline u16
  78 ip6_reass_buffer_get_data_len (vlib_buffer_t * b)
  79 {
  80   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  81   ASSERT (vnb->ip.reass.range_last > vnb->ip.reass.fragment_first);
  82   return ip6_reass_buffer_get_data_len_no_check (b);
  83 }
  84
  85 typedef struct
  86 {
  87   // hash table key
  88   ip6_reass_key_t key;
  89   // time when last packet was received
  90   f64 last_heard;
  91   // internal id of this reassembly
  92   u64 id;
  93   // buffer index of first buffer in this reassembly context
  94   u32 first_bi;
  95   // last octet of packet, ~0 until fragment without more_fragments arrives
  96   u32 last_packet_octet;
  97   // length of data collected so far
  98   u32 data_len;
  99   // trace operation counter
 100   u32 trace_op_counter;
 101   // next index - used by non-feature node
 102   u8 next_index;
 103   // minimum fragment length for this reassembly - used to estimate MTU
 104   u16 min_fragment_length;
 105 } ip6_reass_t;
 106
 107 typedef struct
 108 {
 109   ip6_reass_t *pool;
 110   u32 reass_n;
 111   u32 buffers_n;
 112   u32 id_counter;
 113   clib_spinlock_t lock;
 114 } ip6_reass_per_thread_t;
 115
 116 typedef struct
 117 {
 118   // IPv6 config
 119   u32 timeout_ms;
 120   f64 timeout;
 121   u32 expire_walk_interval_ms;
 122   u32 max_reass_n;
 123
 124   // IPv6 runtime
 125   clib_bihash_48_8_t hash;
 126
 127   // per-thread data
 128   ip6_reass_per_thread_t *per_thread_data;
 129
 130   // convenience
 131   vlib_main_t *vlib_main;
 132   vnet_main_t *vnet_main;
 133
 134   // node index of ip6-drop node
 135   u32 ip6_drop_idx;
 136   u32 ip6_icmp_error_idx;
 137   u32 ip6_reass_expire_node_idx;
 138
 139 } ip6_reass_main_t;
 140
 141 ip6_reass_main_t ip6_reass_main;
 142
 143 typedef enum
 144 {
 145   IP6_REASSEMBLY_NEXT_INPUT,
 146   IP6_REASSEMBLY_NEXT_DROP,
 147   IP6_REASSEMBLY_NEXT_ICMP_ERROR,
 148   IP6_REASSEMBLY_N_NEXT,
 149 } ip6_reass_next_t;
 150
 151 typedef enum
 152 {
 153   RANGE_NEW,
 154   RANGE_OVERLAP,
 155   ICMP_ERROR_RT_EXCEEDED,
 156   ICMP_ERROR_FL_TOO_BIG,
 157   ICMP_ERROR_FL_NOT_MULT_8,
 158   FINALIZE,
 159 } ip6_reass_trace_operation_e;
 160
 161 typedef struct
 162 {
 163   u16 range_first;
 164   u16 range_last;
 165   u32 range_bi;
 166   i32 data_offset;
 167   u32 data_len;
 168   u32 first_bi;
 169 } ip6_reass_range_trace_t;
 170
 171 typedef struct
 172 {
 173   ip6_reass_trace_operation_e action;
 174   u32 reass_id;
 175   ip6_reass_range_trace_t trace_range;
 176   u32 size_diff;
 177   u32 op_id;
 178   u32 fragment_first;
 179   u32 fragment_last;
 180   u32 total_data_len;
 181 } ip6_reass_trace_t;
 182
 183 static void
 184 ip6_reass_trace_details (vlib_main_t * vm, u32 bi,
 185                          ip6_reass_range_trace_t * trace)
 186 {
 187   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 188   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 189   trace->range_first = vnb->ip.reass.range_first;
 190   trace->range_last = vnb->ip.reass.range_last;
 191   trace->data_offset = ip6_reass_buffer_get_data_offset_no_check (b);
 192   trace->data_len = ip6_reass_buffer_get_data_len_no_check (b);
 193   trace->range_bi = bi;
 194 }
 195
 196 static u8 *
 197 format_ip6_reass_range_trace (u8 * s, va_list * args)
 198 {
 199   ip6_reass_range_trace_t *trace = va_arg (*args, ip6_reass_range_trace_t *);
 200   s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
 201               trace->range_last, trace->data_offset, trace->data_len,
 202               trace->range_bi);
 203   return s;
 204 }
 205
 206 static u8 *
 207 format_ip6_reass_trace (u8 * s, va_list * args)
 208 {
 209   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 210   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 211   ip6_reass_trace_t *t = va_arg (*args, ip6_reass_trace_t *);
 212   s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
 213   u32 indent = format_get_indent (s);
 214   s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
 215               t->trace_range.first_bi, t->total_data_len, t->fragment_first,
 216               t->fragment_last);
 217   switch (t->action)
 218     {
 219     case RANGE_NEW:
 220       s = format (s, "\n%Unew %U", format_white_space, indent,
 221                   format_ip6_reass_range_trace, &t->trace_range);
 222       break;
 223     case RANGE_OVERLAP:
 224       s = format (s, "\n%Uoverlap %U", format_white_space, indent,
 225                   format_ip6_reass_range_trace, &t->trace_range);
 226       break;
 227     case ICMP_ERROR_FL_TOO_BIG:
 228       s = format (s, "\n%Uicmp-error - frag_len > 65535 %U",
 229                   format_white_space, indent, format_ip6_reass_range_trace,
 230                   &t->trace_range);
 231       break;
 232     case ICMP_ERROR_FL_NOT_MULT_8:
 233       s = format (s, "\n%Uicmp-error - frag_len mod 8 != 0 %U",
 234                   format_white_space, indent, format_ip6_reass_range_trace,
 235                   &t->trace_range);
 236       break;
 237     case ICMP_ERROR_RT_EXCEEDED:
 238       s = format (s, "\n%Uicmp-error - reassembly time exceeded",
 239                   format_white_space, indent);
 240       break;
 241     case FINALIZE:
 242       s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
 243       break;
 244     }
 245   return s;
 246 }
 247
 248 static void
 249 ip6_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 250                      ip6_reass_main_t * rm, ip6_reass_t * reass,
 251                      u32 bi, ip6_reass_trace_operation_e action,
 252                      u32 size_diff)
 253 {
 254   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 255   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 256   if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
 257     {
 258       // this buffer's trace is gone
 259       b->flags &= ~VLIB_BUFFER_IS_TRACED;
 260       return;
 261     }
 262   ip6_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 263   t->reass_id = reass->id;
 264   t->action = action;
 265   ip6_reass_trace_details (vm, bi, &t->trace_range);
 266   t->size_diff = size_diff;
 267   t->op_id = reass->trace_op_counter;
 268   ++reass->trace_op_counter;
 269   t->fragment_first = vnb->ip.reass.fragment_first;
 270   t->fragment_last = vnb->ip.reass.fragment_last;
 271   t->trace_range.first_bi = reass->first_bi;
 272   t->total_data_len = reass->data_len;
 273 #if 0
 274   static u8 *s = NULL;
 275   s = format (s, "%U", format_ip6_reass_trace, NULL, NULL, t);
 276   printf ("%.*s\n", vec_len (s), s);
 277   fflush (stdout);
 278   vec_reset_length (s);
 279 #endif
 280 }
 281
 282 always_inline void
 283 ip6_reass_free (ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 284                 ip6_reass_t * reass)
 285 {
 286   clib_bihash_kv_48_8_t kv;
 287   kv.key[0] = reass->key.as_u64[0];
 288   kv.key[1] = reass->key.as_u64[1];
 289   kv.key[2] = reass->key.as_u64[2];
 290   kv.key[3] = reass->key.as_u64[3];
 291   kv.key[4] = reass->key.as_u64[4];
 292   kv.key[5] = reass->key.as_u64[5];
 293   clib_bihash_add_del_48_8 (&rm->hash, &kv, 0);
 294   pool_put (rt->pool, reass);
 295   --rt->reass_n;
 296 }
 297
 298 always_inline void
 299 ip6_reass_drop_all (vlib_main_t * vm, ip6_reass_main_t * rm,
 300                     ip6_reass_t * reass, u32 ** vec_drop_bi)
 301 {
 302   u32 range_bi = reass->first_bi;
 303   vlib_buffer_t *range_b;
 304   vnet_buffer_opaque_t *range_vnb;
 305   while (~0 != range_bi)
 306     {
 307       range_b = vlib_get_buffer (vm, range_bi);
 308       range_vnb = vnet_buffer (range_b);
 309       u32 bi = range_bi;
 310       while (~0 != bi)
 311         {
 312           vec_add1 (*vec_drop_bi, bi);
 313           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 314           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 315             {
 316               bi = b->next_buffer;
 317               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 318             }
 319           else
 320             {
 321               bi = ~0;
 322             }
 323         }
 324       range_bi = range_vnb->ip.reass.next_range_bi;
 325     }
 326 }
 327
 328 always_inline void
 329 ip6_reass_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * node,
 330                       ip6_reass_main_t * rm, ip6_reass_t * reass,
 331                       u32 * icmp_bi, u32 ** vec_timeout)
 332 {
 333   if (~0 == reass->first_bi)
 334     {
 335       return;
 336     }
 337   vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
 338   if (0 == vnet_buffer (b)->ip.reass.fragment_first)
 339     {
 340       *icmp_bi = reass->first_bi;
 341       if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
 342         {
 343           ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi,
 344                                ICMP_ERROR_RT_EXCEEDED, 0);
 345         }
 346       // fragment with offset zero received - send icmp message back
 347       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 348         {
 349           // separate first buffer from chain and steer it towards icmp node
 350           b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 351           reass->first_bi = b->next_buffer;
 352         }
 353       else
 354         {
 355           reass->first_bi = vnet_buffer (b)->ip.reass.next_range_bi;
 356         }
 357       icmp6_error_set_vnet_buffer (b, ICMP6_time_exceeded,
 358                                    ICMP6_time_exceeded_fragment_reassembly_time_exceeded,
 359                                    0);
 360     }
 361   ip6_reass_drop_all (vm, rm, reass, vec_timeout);
 362 }
 363
 364 always_inline ip6_reass_t *
 365 ip6_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 366                           ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 367                           ip6_reass_key_t * k, u32 * icmp_bi,
 368                           u32 ** vec_timeout)
 369 {
 370   ip6_reass_t *reass = NULL;
 371   f64 now = vlib_time_now (rm->vlib_main);
 372   clib_bihash_kv_48_8_t kv, value;
 373   kv.key[0] = k->as_u64[0];
 374   kv.key[1] = k->as_u64[1];
 375   kv.key[2] = k->as_u64[2];
 376   kv.key[3] = k->as_u64[3];
 377   kv.key[4] = k->as_u64[4];
 378   kv.key[5] = k->as_u64[5];
 379
 380   if (!clib_bihash_search_48_8 (&rm->hash, &kv, &value))
 381     {
 382       reass = pool_elt_at_index (rt->pool, value.value);
 383       if (now > reass->last_heard + rm->timeout)
 384         {
 385           ip6_reass_on_timeout (vm, node, rm, reass, icmp_bi, vec_timeout);
 386           ip6_reass_free (rm, rt, reass);
 387           reass = NULL;
 388         }
 389     }
 390
 391   if (reass)
 392     {
 393       reass->last_heard = now;
 394       return reass;
 395     }
 396
 397   if (rt->reass_n >= rm->max_reass_n)
 398     {
 399       reass = NULL;
 400       return reass;
 401     }
 402   else
 403     {
 404       pool_get (rt->pool, reass);
 405       memset (reass, 0, sizeof (*reass));
 406       reass->id =
 407         ((u64) os_get_thread_index () * 1000000000) + rt->id_counter;
 408       ++rt->id_counter;
 409       reass->first_bi = ~0;
 410       reass->last_packet_octet = ~0;
 411       reass->data_len = 0;
 412       ++rt->reass_n;
 413     }
 414
 415   reass->key.as_u64[0] = kv.key[0] = k->as_u64[0];
 416   reass->key.as_u64[1] = kv.key[1] = k->as_u64[1];
 417   reass->key.as_u64[2] = kv.key[2] = k->as_u64[2];
 418   reass->key.as_u64[3] = kv.key[3] = k->as_u64[3];
 419   reass->key.as_u64[4] = kv.key[4] = k->as_u64[4];
 420   reass->key.as_u64[5] = kv.key[5] = k->as_u64[5];
 421   kv.value = reass - rt->pool;
 422   reass->last_heard = now;
 423
 424   if (clib_bihash_add_del_48_8 (&rm->hash, &kv, 1))
 425     {
 426       ip6_reass_free (rm, rt, reass);
 427       reass = NULL;
 428     }
 429
 430   return reass;
 431 }
 432
 433 always_inline void
 434 ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 435                     ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 436                     ip6_reass_t * reass, u32 * bi0, u32 * next0,
 437                     u32 * error0, u32 ** vec_drop_compress, bool is_feature)
 438 {
 439   ASSERT (~0 != reass->first_bi);
 440   *bi0 = reass->first_bi;
 441   *error0 = IP6_ERROR_NONE;
 442   ip6_frag_hdr_t *frag_hdr;
 443   vlib_buffer_t *last_b = NULL;
 444   u32 sub_chain_bi = reass->first_bi;
 445   u32 total_length = 0;
 446   u32 buf_cnt = 0;
 447   u32 dropped_cnt = 0;
 448   do
 449     {
 450       u32 tmp_bi = sub_chain_bi;
 451       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 452       u32 data_len = ip6_reass_buffer_get_data_len (tmp);
 453       u32 trim_front = vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 454         sizeof (*frag_hdr) + ip6_reass_buffer_get_data_offset (tmp);
 455       u32 trim_end =
 456         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 457       if (tmp_bi == reass->first_bi)
 458         {
 459           /* first buffer - keep ip6 header */
 460           ASSERT (0 == ip6_reass_buffer_get_data_offset (tmp));
 461           trim_front = 0;
 462           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 463             (vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 464              sizeof (*frag_hdr));
 465           ASSERT (vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0);
 466         }
 467       u32 keep_data =
 468         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 469       while (1)
 470         {
 471           ++buf_cnt;
 472           if (trim_front)
 473             {
 474               if (trim_front > tmp->current_length)
 475                 {
 476                   /* drop whole buffer */
 477                   vec_add1 (*vec_drop_compress, tmp_bi);
 478                   ++dropped_cnt;
 479                   trim_front -= tmp->current_length;
 480                   ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
 481                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 482                   tmp_bi = tmp->next_buffer;
 483                   tmp = vlib_get_buffer (vm, tmp_bi);
 484                   continue;
 485                 }
 486               else
 487                 {
 488                   vlib_buffer_advance (tmp, trim_front);
 489                   trim_front = 0;
 490                 }
 491             }
 492           if (keep_data)
 493             {
 494               if (last_b)
 495                 {
 496                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 497                   last_b->next_buffer = tmp_bi;
 498                 }
 499               last_b = tmp;
 500               if (keep_data <= tmp->current_length)
 501                 {
 502                   tmp->current_length = keep_data;
 503                   keep_data = 0;
 504                 }
 505               else
 506                 {
 507                   keep_data -= tmp->current_length;
 508                   ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
 509                 }
 510               total_length += tmp->current_length;
 511             }
 512           else
 513             {
 514               vec_add1 (*vec_drop_compress, tmp_bi);
 515               ASSERT (reass->first_bi != tmp_bi);
 516               ++dropped_cnt;
 517             }
 518           if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 519             {
 520               tmp_bi = tmp->next_buffer;
 521               tmp = vlib_get_buffer (vm, tmp->next_buffer);
 522             }
 523           else
 524             {
 525               break;
 526             }
 527         }
 528       sub_chain_bi =
 529         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 530         reass.next_range_bi;
 531     }
 532   while (~0 != sub_chain_bi);
 533
 534   ASSERT (last_b != NULL);
 535   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 536   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 537   ASSERT (total_length >= first_b->current_length);
 538   total_length -= first_b->current_length;
 539   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 540   first_b->total_length_not_including_first_buffer = total_length;
 541   // drop fragment header
 542   vnet_buffer_opaque_t *first_b_vnb = vnet_buffer (first_b);
 543   ip6_header_t *ip = vlib_buffer_get_current (first_b);
 544   u16 ip6_frag_hdr_offset = first_b_vnb->ip.reass.ip6_frag_hdr_offset;
 545   ip6_ext_header_t *prev_hdr;
 546   ip6_ext_header_find_t (ip, prev_hdr, frag_hdr,
 547                          IP_PROTOCOL_IPV6_FRAGMENTATION);
 548   if (prev_hdr)
 549     {
 550       prev_hdr->next_hdr = frag_hdr->next_hdr;
 551     }
 552   else
 553     {
 554       ip->protocol = frag_hdr->next_hdr;
 555     }
 556   ASSERT ((u8 *) frag_hdr - (u8 *) ip == ip6_frag_hdr_offset);
 557   memmove (frag_hdr, (u8 *) frag_hdr + sizeof (*frag_hdr),
 558            first_b->current_length - ip6_frag_hdr_offset -
 559            sizeof (ip6_frag_hdr_t));
 560   first_b->current_length -= sizeof (*frag_hdr);
 561   ip->payload_length =
 562     clib_host_to_net_u16 (total_length + first_b->current_length -
 563                           sizeof (*ip));
 564   vlib_buffer_chain_compress (vm, first_b, vec_drop_compress);
 565   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 566     {
 567       ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 568 #if 0
 569       // following code does a hexdump of packet fragments to stdout ...
 570       do
 571         {
 572           u32 bi = reass->first_bi;
 573           u8 *s = NULL;
 574           while (~0 != bi)
 575             {
 576               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 577               s = format (s, "%u: %U\n", bi, format_hexdump,
 578                           vlib_buffer_get_current (b), b->current_length);
 579               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 580                 {
 581                   bi = b->next_buffer;
 582                 }
 583               else
 584                 {
 585                   break;
 586                 }
 587             }
 588           printf ("%.*s\n", vec_len (s), s);
 589           fflush (stdout);
 590           vec_free (s);
 591         }
 592       while (0);
 593 #endif
 594     }
 595   if (is_feature)
 596     {
 597       *next0 = IP6_REASSEMBLY_NEXT_INPUT;
 598     }
 599   else
 600     {
 601       *next0 = reass->next_index;
 602     }
 603   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 604   ip6_reass_free (rm, rt, reass);
 605   reass = NULL;
 606 }
 607
 608 always_inline u32
 609 ip6_reass_get_buffer_chain_length (vlib_main_t * vm, vlib_buffer_t * b)
 610 {
 611   u32 len = 0;
 612   while (b)
 613     {
 614       ++len;
 615       if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
 616         {
 617           b = vlib_get_buffer (vm, b->next_buffer);
 618         }
 619       else
 620         {
 621           break;
 622         }
 623     }
 624   return len;
 625 }
 626
 627 always_inline void
 628 ip6_reass_insert_range_in_chain (vlib_main_t * vm, ip6_reass_main_t * rm,
 629                                  ip6_reass_per_thread_t * rt,
 630                                  ip6_reass_t * reass, u32 prev_range_bi,
 631                                  u32 new_next_bi)
 632 {
 633
 634   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 635   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 636   if (~0 != prev_range_bi)
 637     {
 638       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 639       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 640       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 641       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 642     }
 643   else
 644     {
 645       if (~0 != reass->first_bi)
 646         {
 647           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 648         }
 649       reass->first_bi = new_next_bi;
 650     }
 651   reass->data_len += ip6_reass_buffer_get_data_len (new_next_b);
 652   rt->buffers_n += ip6_reass_get_buffer_chain_length (vm, new_next_b);
 653 }
 654
 655 always_inline void
 656 ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 657                   ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 658                   ip6_reass_t * reass, u32 * bi0, u32 * next0,
 659                   u32 * error0, ip6_frag_hdr_t * frag_hdr,
 660                   u32 ** vec_drop_overlap, u32 ** vec_drop_compress,
 661                   bool is_feature)
 662 {
 663   int consumed = 0;
 664   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 665   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 666   reass->next_index = fvnb->ip.reass.next_index;        // store next_index before it's overwritten
 667   fvnb->ip.reass.ip6_frag_hdr_offset =
 668     (u8 *) frag_hdr - (u8 *) vlib_buffer_get_current (fb);
 669   ip6_header_t *fip = vlib_buffer_get_current (fb);
 670   ASSERT (fb->current_length > sizeof (*fip));
 671   ASSERT (fvnb->ip.reass.ip6_frag_hdr_offset > 0 &&
 672           fvnb->ip.reass.ip6_frag_hdr_offset < fb->current_length);
 673   u32 fragment_first = fvnb->ip.reass.fragment_first =
 674     ip6_frag_hdr_offset_bytes (frag_hdr);
 675   u32 fragment_length =
 676     vlib_buffer_length_in_chain (vm, fb) -
 677     (fvnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 678   u32 fragment_last = fvnb->ip.reass.fragment_last =
 679     fragment_first + fragment_length - 1;
 680   int more_fragments = ip6_frag_hdr_more (frag_hdr);
 681   u32 candidate_range_bi = reass->first_bi;
 682   u32 prev_range_bi = ~0;
 683   fvnb->ip.reass.range_first = fragment_first;
 684   fvnb->ip.reass.range_last = fragment_last;
 685   fvnb->ip.reass.next_range_bi = ~0;
 686   if (!more_fragments)
 687     {
 688       reass->last_packet_octet = fragment_last;
 689     }
 690   if (~0 == reass->first_bi)
 691     {
 692       // starting a new reassembly
 693       ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 694                                        *bi0);
 695       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 696         {
 697           ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 698         }
 699       reass->min_fragment_length = clib_net_to_host_u16 (fip->payload_length);
 700       *bi0 = ~0;
 701       return;
 702     }
 703   reass->min_fragment_length =
 704     clib_min (clib_net_to_host_u16 (fip->payload_length),
 705               fvnb->ip.reass.estimated_mtu);
 706   while (~0 != candidate_range_bi)
 707     {
 708       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 709       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 710       if (fragment_first > candidate_vnb->ip.reass.range_last)
 711         {
 712           // this fragments starts after candidate range
 713           prev_range_bi = candidate_range_bi;
 714           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 715           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 716               ~0 == candidate_range_bi)
 717             {
 718               // special case - this fragment falls beyond all known ranges
 719               ip6_reass_insert_range_in_chain (vm, rm, rt, reass,
 720                                                prev_range_bi, *bi0);
 721               consumed = 1;
 722               break;
 723             }
 724           continue;
 725         }
 726       if (fragment_last < candidate_vnb->ip.reass.range_first)
 727         {
 728           // this fragment ends before candidate range without any overlap
 729           ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 730                                            *bi0);
 731           consumed = 1;
 732         }
 733       else if (fragment_first == candidate_vnb->ip.reass.range_first &&
 734                fragment_last == candidate_vnb->ip.reass.range_last)
 735         {
 736           // duplicate fragment - ignore
 737         }
 738       else
 739         {
 740           // overlapping fragment - not allowed by RFC 8200
 741           ip6_reass_drop_all (vm, rm, reass, vec_drop_overlap);
 742           ip6_reass_free (rm, rt, reass);
 743           if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 744             {
 745               ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_OVERLAP,
 746                                    0);
 747             }
 748           *next0 = IP6_REASSEMBLY_NEXT_DROP;
 749           *error0 = IP6_ERROR_REASS_OVERLAPPING_FRAGMENT;
 750         }
 751       break;
 752     }
 753   if (consumed)
 754     {
 755       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 756         {
 757           ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 758         }
 759     }
 760   if (~0 != reass->last_packet_octet &&
 761       reass->data_len == reass->last_packet_octet + 1)
 762     {
 763       ip6_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 764                           vec_drop_compress, is_feature);
 765     }
 766   else
 767     {
 768       if (consumed)
 769         {
 770           *bi0 = ~0;
 771         }
 772       else
 773         {
 774           *next0 = IP6_REASSEMBLY_NEXT_DROP;
 775           ;
 776           *error0 = IP6_ERROR_REASS_DUPLICATE_FRAGMENT;
 777         }
 778     }
 779 }
 780
 781 always_inline bool
 782 ip6_reass_verify_upper_layer_present (vlib_node_runtime_t * node,
 783                                       vlib_buffer_t * b,
 784                                       ip6_frag_hdr_t * frag_hdr)
 785 {
 786   ip6_ext_header_t *tmp = (ip6_ext_header_t *) frag_hdr;
 787   while (ip6_ext_hdr (tmp->next_hdr))
 788     {
 789       tmp = ip6_ext_next_header (tmp);
 790     }
 791   if (IP_PROTOCOL_IP6_NONXT == tmp->next_hdr)
 792     {
 793       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 794                                    ICMP6_parameter_problem_first_fragment_has_incomplete_header_chain,
 795                                    0);
 796       b->error = node->errors[IP6_ERROR_REASS_MISSING_UPPER];
 797
 798       return false;
 799     }
 800   return true;
 801 }
 802
 803 always_inline bool
 804 ip6_reass_verify_fragment_multiple_8 (vlib_main_t * vm,
 805                                       vlib_node_runtime_t * node,
 806                                       vlib_buffer_t * b,
 807                                       ip6_frag_hdr_t * frag_hdr)
 808 {
 809   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 810   ip6_header_t *ip = vlib_buffer_get_current (b);
 811   int more_fragments = ip6_frag_hdr_more (frag_hdr);
 812   u32 fragment_length =
 813     vlib_buffer_length_in_chain (vm, b) -
 814     (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 815   if (more_fragments && 0 != fragment_length % 8)
 816     {
 817       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 818                                    ICMP6_parameter_problem_erroneous_header_field,
 819                                    (u8 *) & ip->payload_length - (u8 *) ip);
 820       return false;
 821     }
 822   return true;
 823 }
 824
 825 always_inline bool
 826 ip6_reass_verify_packet_size_lt_64k (vlib_main_t * vm,
 827                                      vlib_node_runtime_t * node,
 828                                      vlib_buffer_t * b,
 829                                      ip6_frag_hdr_t * frag_hdr)
 830 {
 831   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 832   u32 fragment_first = ip6_frag_hdr_offset_bytes (frag_hdr);
 833   u32 fragment_length =
 834     vlib_buffer_length_in_chain (vm, b) -
 835     (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 836   if (fragment_first + fragment_length > 65535)
 837     {
 838       ip6_header_t *ip0 = vlib_buffer_get_current (b);
 839       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 840                                    ICMP6_parameter_problem_erroneous_header_field,
 841                                    (u8 *) & frag_hdr->fragment_offset_and_more
 842                                    - (u8 *) ip0);
 843       return false;
 844     }
 845   return true;
 846 }
 847
 848 always_inline uword
 849 ip6_reassembly_inline (vlib_main_t * vm,
 850                        vlib_node_runtime_t * node,
 851                        vlib_frame_t * frame, bool is_feature)
 852 {
 853   u32 *from = vlib_frame_vector_args (frame);
 854   u32 n_left_from, n_left_to_next, *to_next, next_index;
 855   ip6_reass_main_t *rm = &ip6_reass_main;
 856   ip6_reass_per_thread_t *rt = &rm->per_thread_data[os_get_thread_index ()];
 857   clib_spinlock_lock (&rt->lock);
 858
 859   n_left_from = frame->n_vectors;
 860   next_index = node->cached_next_index;
 861   static u32 *vec_timeout = NULL;       // indexes of buffers which timed out
 862   static u32 *vec_drop_overlap = NULL;  // indexes of buffers dropped due to overlap
 863   static u32 *vec_drop_compress = NULL; // indexes of buffers dropped due to buffer compression
 864   while (n_left_from > 0 || vec_len (vec_timeout) > 0 ||
 865          vec_len (vec_drop_overlap) > 0 || vec_len (vec_drop_compress) > 0)
 866     {
 867       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 868
 869       while (vec_len (vec_timeout) > 0 && n_left_to_next > 0)
 870         {
 871           u32 bi = vec_pop (vec_timeout);
 872           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 873           b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
 874           to_next[0] = bi;
 875           to_next += 1;
 876           n_left_to_next -= 1;
 877           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 878                                            n_left_to_next, bi,
 879                                            IP6_REASSEMBLY_NEXT_DROP);
 880           ASSERT (rt->buffers_n > 0);
 881           --rt->buffers_n;
 882         }
 883
 884       while (vec_len (vec_drop_overlap) > 0 && n_left_to_next > 0)
 885         {
 886           u32 bi = vec_pop (vec_drop_overlap);
 887           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 888           b->error = node->errors[IP6_ERROR_REASS_OVERLAPPING_FRAGMENT];
 889           to_next[0] = bi;
 890           to_next += 1;
 891           n_left_to_next -= 1;
 892           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 893                                            n_left_to_next, bi,
 894                                            IP6_REASSEMBLY_NEXT_DROP);
 895           ASSERT (rt->buffers_n > 0);
 896           --rt->buffers_n;
 897         }
 898
 899       while (vec_len (vec_drop_compress) > 0 && n_left_to_next > 0)
 900         {
 901           u32 bi = vec_pop (vec_drop_compress);
 902           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 903           b->error = node->errors[IP6_ERROR_NONE];
 904           to_next[0] = bi;
 905           to_next += 1;
 906           n_left_to_next -= 1;
 907           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 908                                            n_left_to_next, bi,
 909                                            IP6_REASSEMBLY_NEXT_DROP);
 910           ASSERT (rt->buffers_n > 0);
 911           --rt->buffers_n;
 912         }
 913
 914       while (n_left_from > 0 && n_left_to_next > 0)
 915         {
 916           u32 bi0;
 917           vlib_buffer_t *b0;
 918           u32 next0;
 919           u32 error0 = IP6_ERROR_NONE;
 920           u32 icmp_bi = ~0;
 921
 922           bi0 = from[0];
 923           b0 = vlib_get_buffer (vm, bi0);
 924
 925           ip6_header_t *ip0 = vlib_buffer_get_current (b0);
 926           ip6_frag_hdr_t *frag_hdr = NULL;
 927           ip6_ext_header_t *prev_hdr;
 928           if (ip6_ext_hdr (ip0->protocol))
 929             {
 930               ip6_ext_header_find_t (ip0, prev_hdr, frag_hdr,
 931                                      IP_PROTOCOL_IPV6_FRAGMENTATION);
 932             }
 933           if (!frag_hdr)
 934             {
 935               // this is a regular packet - no fragmentation
 936               next0 = IP6_REASSEMBLY_NEXT_INPUT;
 937               goto skip_reass;
 938             }
 939           if (0 == ip6_frag_hdr_offset (frag_hdr))
 940             {
 941               // first fragment - verify upper-layer is present
 942               if (!ip6_reass_verify_upper_layer_present (node, b0, frag_hdr))
 943                 {
 944                   next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
 945                   goto skip_reass;
 946                 }
 947             }
 948           if (!ip6_reass_verify_fragment_multiple_8 (vm, node, b0, frag_hdr)
 949               || !ip6_reass_verify_packet_size_lt_64k (vm, node, b0,
 950                                                        frag_hdr))
 951             {
 952               next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
 953               goto skip_reass;
 954             }
 955           vnet_buffer (b0)->ip.reass.ip6_frag_hdr_offset =
 956             (u8 *) frag_hdr - (u8 *) ip0;
 957
 958           ip6_reass_key_t k;
 959           k.as_u64[0] = ip0->src_address.as_u64[0];
 960           k.as_u64[1] = ip0->src_address.as_u64[1];
 961           k.as_u64[2] = ip0->dst_address.as_u64[0];
 962           k.as_u64[3] = ip0->dst_address.as_u64[1];
 963           k.as_u64[4] =
 964             (u64) vnet_buffer (b0)->
 965             sw_if_index[VLIB_RX] << 32 | frag_hdr->identification;
 966           k.as_u64[5] = ip0->protocol;
 967           ip6_reass_t *reass =
 968             ip6_reass_find_or_create (vm, node, rm, rt, &k, &icmp_bi,
 969                                       &vec_timeout);
 970
 971           if (reass)
 972             {
 973               ip6_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
 974                                 &error0, frag_hdr, &vec_drop_overlap,
 975                                 &vec_drop_compress, is_feature);
 976             }
 977           else
 978             {
 979               next0 = IP6_REASSEMBLY_NEXT_DROP;
 980               error0 = IP6_ERROR_REASS_LIMIT_REACHED;
 981             }
 982
 983           b0->error = node->errors[error0];
 984
 985           if (~0 != bi0)
 986             {
 987             skip_reass:
 988               to_next[0] = bi0;
 989               to_next += 1;
 990               n_left_to_next -= 1;
 991               if (is_feature && IP6_ERROR_NONE == error0)
 992                 {
 993                   vnet_feature_next (&next0, b0);
 994                 }
 995               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 996                                                n_left_to_next, bi0, next0);
 997             }
 998
 999           if (~0 != icmp_bi)
1000             {
1001               next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
1002               to_next[0] = icmp_bi;
1003               to_next += 1;
1004               n_left_to_next -= 1;
1005               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1006                                                n_left_to_next, icmp_bi,
1007                                                next0);
1008             }
1009           from += 1;
1010           n_left_from -= 1;
1011         }
1012
1013       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1014     }
1015
1016   clib_spinlock_unlock (&rt->lock);
1017   return frame->n_vectors;
1018 }
1019
1020 static char *ip6_reassembly_error_strings[] = {
1021 #define _(sym, string) string,
1022   foreach_ip6_error
1023 #undef _
1024 };
1025
1026 static uword
1027 ip6_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
1028                 vlib_frame_t * frame)
1029 {
1030   return ip6_reassembly_inline (vm, node, frame, false /* is_feature */ );
1031 }
1032
1033 /* *INDENT-OFF* */
1034 VLIB_REGISTER_NODE (ip6_reass_node, static) = {
1035     .function = ip6_reassembly,
1036     .name = "ip6-reassembly",
1037     .vector_size = sizeof (u32),
1038     .format_trace = format_ip6_reass_trace,
1039     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1040     .error_strings = ip6_reassembly_error_strings,
1041     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1042     .next_nodes =
1043         {
1044                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1045                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1046                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1047         },
1048 };
1049 /* *INDENT-ON* */
1050
1051 VLIB_NODE_FUNCTION_MULTIARCH (ip6_reass_node, ip6_reassembly);
1052
1053 static uword
1054 ip6_reassembly_feature (vlib_main_t * vm,
1055                         vlib_node_runtime_t * node, vlib_frame_t * frame)
1056 {
1057   return ip6_reassembly_inline (vm, node, frame, true /* is_feature */ );
1058 }
1059
1060 /* *INDENT-OFF* */
1061 VLIB_REGISTER_NODE (ip6_reass_node_feature, static) = {
1062     .function = ip6_reassembly_feature,
1063     .name = "ip6-reassembly-feature",
1064     .vector_size = sizeof (u32),
1065     .format_trace = format_ip6_reass_trace,
1066     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1067     .error_strings = ip6_reassembly_error_strings,
1068     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1069     .next_nodes =
1070         {
1071                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1072                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1073                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1074         },
1075 };
1076 /* *INDENT-ON* */
1077
1078 VLIB_NODE_FUNCTION_MULTIARCH (ip6_reass_node_feature, ip6_reassembly_feature);
1079
1080 /* *INDENT-OFF* */
1081 VNET_FEATURE_INIT (ip6_reassembly_feature, static) = {
1082     .arc_name = "ip6-unicast",
1083     .node_name = "ip6-reassembly-feature",
1084     .runs_before = VNET_FEATURES ("ip6-lookup"),
1085     .runs_after = 0,
1086 };
1087 /* *INDENT-ON* */
1088
1089 static u32
1090 ip6_reass_get_nbuckets ()
1091 {
1092   ip6_reass_main_t *rm = &ip6_reass_main;
1093   u32 nbuckets;
1094   u8 i;
1095
1096   nbuckets = (u32) (rm->max_reass_n / IP6_REASS_HT_LOAD_FACTOR);
1097
1098   for (i = 0; i < 31; i++)
1099     if ((1 << i) >= nbuckets)
1100       break;
1101   nbuckets = 1 << i;
1102
1103   return nbuckets;
1104 }
1105
1106 typedef enum
1107 {
1108   IP6_EVENT_CONFIG_CHANGED = 1,
1109 } ip6_reass_event_t;
1110
1111 typedef struct
1112 {
1113   int failure;
1114   clib_bihash_48_8_t *new_hash;
1115 } ip6_rehash_cb_ctx;
1116
1117 static void
1118 ip6_rehash_cb (clib_bihash_kv_48_8_t * kv, void *_ctx)
1119 {
1120   ip6_rehash_cb_ctx *ctx = _ctx;
1121   if (clib_bihash_add_del_48_8 (ctx->new_hash, kv, 1))
1122     {
1123       ctx->failure = 1;
1124     }
1125 }
1126
1127 static void
1128 ip6_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1129                       u32 expire_walk_interval_ms)
1130 {
1131   ip6_reass_main.timeout_ms = timeout_ms;
1132   ip6_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1133   ip6_reass_main.max_reass_n = max_reassemblies;
1134   ip6_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1135 }
1136
1137 vnet_api_error_t
1138 ip6_reass_set (u32 timeout_ms, u32 max_reassemblies,
1139                u32 expire_walk_interval_ms)
1140 {
1141   u32 old_nbuckets = ip6_reass_get_nbuckets ();
1142   ip6_reass_set_params (timeout_ms, max_reassemblies,
1143                         expire_walk_interval_ms);
1144   vlib_process_signal_event (ip6_reass_main.vlib_main,
1145                              ip6_reass_main.ip6_reass_expire_node_idx,
1146                              IP6_EVENT_CONFIG_CHANGED, 0);
1147   u32 new_nbuckets = ip6_reass_get_nbuckets ();
1148   if (ip6_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1149     {
1150       clib_bihash_48_8_t new_hash;
1151       memset (&new_hash, 0, sizeof (new_hash));
1152       ip6_rehash_cb_ctx ctx;
1153       ctx.failure = 0;
1154       ctx.new_hash = &new_hash;
1155       clib_bihash_init_48_8 (&new_hash, "ip6-reass", new_nbuckets,
1156                              new_nbuckets * 1024);
1157       clib_bihash_foreach_key_value_pair_48_8 (&ip6_reass_main.hash,
1158                                                ip6_rehash_cb, &ctx);
1159       if (ctx.failure)
1160         {
1161           clib_bihash_free_48_8 (&new_hash);
1162           return -1;
1163         }
1164       else
1165         {
1166           clib_bihash_free_48_8 (&ip6_reass_main.hash);
1167           clib_memcpy (&ip6_reass_main.hash, &new_hash,
1168                        sizeof (ip6_reass_main.hash));
1169         }
1170     }
1171   return 0;
1172 }
1173
1174 vnet_api_error_t
1175 ip6_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1176                u32 * expire_walk_interval_ms)
1177 {
1178   *timeout_ms = ip6_reass_main.timeout_ms;
1179   *max_reassemblies = ip6_reass_main.max_reass_n;
1180   *expire_walk_interval_ms = ip6_reass_main.expire_walk_interval_ms;
1181   return 0;
1182 }
1183
1184 static clib_error_t *
1185 ip6_reass_init_function (vlib_main_t * vm)
1186 {
1187   ip6_reass_main_t *rm = &ip6_reass_main;
1188   clib_error_t *error = 0;
1189   u32 nbuckets;
1190   vlib_node_t *node;
1191
1192   rm->vlib_main = vm;
1193   rm->vnet_main = vnet_get_main ();
1194
1195   vec_validate (rm->per_thread_data, vlib_num_workers () + 1);
1196   ip6_reass_per_thread_t *rt;
1197   vec_foreach (rt, rm->per_thread_data)
1198   {
1199     clib_spinlock_init (&rt->lock);
1200     pool_alloc (rt->pool, rm->max_reass_n);
1201   }
1202
1203   node = vlib_get_node_by_name (vm, (u8 *) "ip6-reassembly-expire-walk");
1204   ASSERT (node);
1205   rm->ip6_reass_expire_node_idx = node->index;
1206
1207   ip6_reass_set_params (IP6_REASS_TIMEOUT_DEFAULT_MS,
1208                         IP6_REASS_MAX_REASSEMBLIES_DEFAULT,
1209                         IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1210
1211   nbuckets = ip6_reass_get_nbuckets ();
1212   clib_bihash_init_48_8 (&rm->hash, "ip6-reass", nbuckets, nbuckets * 1024);
1213
1214   node = vlib_get_node_by_name (vm, (u8 *) "ip6-drop");
1215   ASSERT (node);
1216   rm->ip6_drop_idx = node->index;
1217   node = vlib_get_node_by_name (vm, (u8 *) "ip6-icmp-error");
1218   ASSERT (node);
1219   rm->ip6_icmp_error_idx = node->index;
1220
1221   if ((error = vlib_call_init_function (vm, ip_main_init)))
1222     return error;
1223   ip6_register_protocol (IP_PROTOCOL_IPV6_FRAGMENTATION,
1224                          ip6_reass_node.index);
1225
1226   return error;
1227 }
1228
1229 VLIB_INIT_FUNCTION (ip6_reass_init_function);
1230
1231 static uword
1232 ip6_reass_walk_expired (vlib_main_t * vm,
1233                         vlib_node_runtime_t * node, vlib_frame_t * f)
1234 {
1235   ip6_reass_main_t *rm = &ip6_reass_main;
1236   uword event_type, *event_data = 0;
1237
1238   while (true)
1239     {
1240       vlib_process_wait_for_event_or_clock (vm,
1241                                             (f64) rm->expire_walk_interval_ms
1242                                             / (f64) MSEC_PER_SEC);
1243       event_type = vlib_process_get_events (vm, &event_data);
1244
1245       switch (event_type)
1246         {
1247         case ~0:                /* no events => timeout */
1248           /* nothing to do here */
1249           break;
1250         case IP6_EVENT_CONFIG_CHANGED:
1251           break;
1252         default:
1253           clib_warning ("BUG: event type 0x%wx", event_type);
1254           break;
1255         }
1256       f64 now = vlib_time_now (vm);
1257
1258       ip6_reass_t *reass;
1259       u32 *vec_timeout = NULL;
1260       int *pool_indexes_to_free = NULL;
1261
1262       uword thread_index = 0;
1263       int index;
1264       const uword nthreads = os_get_nthreads ();
1265       u32 *vec_icmp_bi = NULL;
1266       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1267         {
1268           ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1269           clib_spinlock_lock (&rt->lock);
1270
1271           vec_reset_length (pool_indexes_to_free);
1272           /* *INDENT-OFF* */
1273           pool_foreach_index (index, rt->pool, ({
1274                                 reass = pool_elt_at_index (rt->pool, index);
1275                                 if (now > reass->last_heard + rm->timeout)
1276                                   {
1277                                     vec_add1 (pool_indexes_to_free, index);
1278                                   }
1279                               }));
1280           /* *INDENT-ON* */
1281           int *i;
1282           /* *INDENT-OFF* */
1283           vec_foreach (i, pool_indexes_to_free)
1284           {
1285             ip6_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1286             u32 icmp_bi = ~0;
1287             u32 before = vec_len (vec_timeout);
1288             vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
1289             if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1290               {
1291                 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1292                                         b->trace_index))
1293                   {
1294                     /* the trace is gone, don't trace this buffer anymore */
1295                     b->flags &= ~VLIB_BUFFER_IS_TRACED;
1296                   }
1297               }
1298             ip6_reass_on_timeout (vm, node, rm, reass, &icmp_bi, &vec_timeout);
1299             u32 after = vec_len (vec_timeout);
1300             ASSERT (rt->buffers_n >= (after - before));
1301             rt->buffers_n -= (after - before);
1302             if (~0 != icmp_bi)
1303               {
1304                 vec_add1 (vec_icmp_bi, icmp_bi);
1305                 ASSERT (rt->buffers_n > 0);
1306                 --rt->buffers_n;
1307               }
1308             ip6_reass_free (rm, rt, reass);
1309           }
1310           /* *INDENT-ON* */
1311
1312           clib_spinlock_unlock (&rt->lock);
1313         }
1314
1315       while (vec_len (vec_timeout) > 0)
1316         {
1317           vlib_frame_t *f = vlib_get_frame_to_node (vm, rm->ip6_drop_idx);
1318           u32 *to_next = vlib_frame_vector_args (f);
1319           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1320           int trace_frame = 0;
1321           while (vec_len (vec_timeout) > 0 && n_left_to_next > 0)
1322             {
1323               u32 bi = vec_pop (vec_timeout);
1324               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1325               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1326                 {
1327                   if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1328                                           b->trace_index))
1329                     {
1330                       /* the trace is gone, don't trace this buffer anymore */
1331                       b->flags &= ~VLIB_BUFFER_IS_TRACED;
1332                     }
1333                   else
1334                     {
1335                       trace_frame = 1;
1336                     }
1337                 }
1338               b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
1339               to_next[0] = bi;
1340               ++f->n_vectors;
1341               to_next += 1;
1342               n_left_to_next -= 1;
1343             }
1344           f->flags |= (trace_frame * VLIB_FRAME_TRACE);
1345           vlib_put_frame_to_node (vm, rm->ip6_drop_idx, f);
1346         }
1347
1348       while (vec_len (vec_icmp_bi) > 0)
1349         {
1350           vlib_frame_t *f =
1351             vlib_get_frame_to_node (vm, rm->ip6_icmp_error_idx);
1352           u32 *to_next = vlib_frame_vector_args (f);
1353           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1354           int trace_frame = 0;
1355           while (vec_len (vec_icmp_bi) > 0 && n_left_to_next > 0)
1356             {
1357               u32 bi = vec_pop (vec_icmp_bi);
1358               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1359               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1360                 {
1361                   if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1362                                           b->trace_index))
1363                     {
1364                       /* the trace is gone, don't trace this buffer anymore */
1365                       b->flags &= ~VLIB_BUFFER_IS_TRACED;
1366                     }
1367                   else
1368                     {
1369                       trace_frame = 1;
1370                     }
1371                 }
1372               b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
1373               to_next[0] = bi;
1374               ++f->n_vectors;
1375               to_next += 1;
1376               n_left_to_next -= 1;
1377             }
1378           f->flags |= (trace_frame * VLIB_FRAME_TRACE);
1379           vlib_put_frame_to_node (vm, rm->ip6_icmp_error_idx, f);
1380         }
1381
1382       vec_free (pool_indexes_to_free);
1383       vec_free (vec_timeout);
1384       vec_free (vec_icmp_bi);
1385       if (event_data)
1386         {
1387           _vec_len (event_data) = 0;
1388         }
1389     }
1390
1391   return 0;
1392 }
1393
1394 static vlib_node_registration_t ip6_reass_expire_node;
1395
1396 /* *INDENT-OFF* */
1397 VLIB_REGISTER_NODE (ip6_reass_expire_node, static) = {
1398     .function = ip6_reass_walk_expired,
1399     .format_trace = format_ip6_reass_trace,
1400     .type = VLIB_NODE_TYPE_PROCESS,
1401     .name = "ip6-reassembly-expire-walk",
1402
1403     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1404     .error_strings = ip6_reassembly_error_strings,
1405
1406 };
1407 /* *INDENT-ON* */
1408
1409 static u8 *
1410 format_ip6_reass_key (u8 * s, va_list * args)
1411 {
1412   ip6_reass_key_t *key = va_arg (*args, ip6_reass_key_t *);
1413   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1414               key->xx_id, format_ip6_address, &key->src, format_ip6_address,
1415               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1416   return s;
1417 }
1418
1419 static u8 *
1420 format_ip6_reass (u8 * s, va_list * args)
1421 {
1422   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1423   ip6_reass_t *reass = va_arg (*args, ip6_reass_t *);
1424
1425   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1426               "last_packet_octet: %u, trace_op_counter: %u\n",
1427               reass->id, format_ip6_reass_key, &reass->key, reass->first_bi,
1428               reass->data_len, reass->last_packet_octet,
1429               reass->trace_op_counter);
1430   u32 bi = reass->first_bi;
1431   u32 counter = 0;
1432   while (~0 != bi)
1433     {
1434       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1435       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1436       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1437                   "fragment[%u, %u]\n",
1438                   counter, vnb->ip.reass.range_first,
1439                   vnb->ip.reass.range_last, bi,
1440                   ip6_reass_buffer_get_data_offset_no_check (b),
1441                   ip6_reass_buffer_get_data_len_no_check (b),
1442                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1443       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1444         {
1445           bi = b->next_buffer;
1446         }
1447       else
1448         {
1449           bi = ~0;
1450         }
1451     }
1452   return s;
1453 }
1454
1455 static clib_error_t *
1456 show_ip6_reass (vlib_main_t * vm, unformat_input_t * input,
1457                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1458 {
1459   ip6_reass_main_t *rm = &ip6_reass_main;
1460
1461   vlib_cli_output (vm, "---------------------");
1462   vlib_cli_output (vm, "IP6 reassembly status");
1463   vlib_cli_output (vm, "---------------------");
1464   bool details = false;
1465   if (unformat (input, "details"))
1466     {
1467       details = true;
1468     }
1469
1470   u32 sum_reass_n = 0;
1471   u64 sum_buffers_n = 0;
1472   ip6_reass_t *reass;
1473   uword thread_index;
1474   const uword nthreads = os_get_nthreads ();
1475   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1476     {
1477       ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1478       clib_spinlock_lock (&rt->lock);
1479       if (details)
1480         {
1481           /* *INDENT-OFF* */
1482           pool_foreach (reass, rt->pool, {
1483             vlib_cli_output (vm, "%U", format_ip6_reass, vm, reass);
1484           });
1485           /* *INDENT-ON* */
1486         }
1487       sum_reass_n += rt->reass_n;
1488       sum_buffers_n += rt->buffers_n;
1489       clib_spinlock_unlock (&rt->lock);
1490     }
1491   vlib_cli_output (vm, "---------------------");
1492   vlib_cli_output (vm, "Current IP6 reassemblies count: %lu\n",
1493                    (long unsigned) sum_reass_n);
1494   vlib_cli_output (vm, "Maximum configured concurrent IP6 reassemblies per "
1495                    "worker-thread: %lu\n", (long unsigned) rm->max_reass_n);
1496   vlib_cli_output (vm, "Buffers in use: %lu\n",
1497                    (long unsigned) sum_buffers_n);
1498   return 0;
1499 }
1500
1501 /* *INDENT-OFF* */
1502 VLIB_CLI_COMMAND (show_ip6_reassembly_cmd, static) = {
1503     .path = "show ip6-reassembly",
1504     .short_help = "show ip6-reassembly [details]",
1505     .function = show_ip6_reass,
1506 };
1507 /* *INDENT-ON* */
1508
1509 vnet_api_error_t
1510 ip6_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1511 {
1512   return vnet_feature_enable_disable ("ip6-unicast", "ip6-reassembly-feature",
1513                                       sw_if_index, enable_disable, 0, 0);
1514 }
1515
1516 /*
1517  * fd.io coding-style-patch-verification: ON
1518  *
1519  * Local Variables:
1520  * eval: (c-set-style "gnu")
1521  * End:
1522  */