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       // align by making this 4 octets even though its a 2 octets field
  46       u32 xx_id;
  47       // align by making this 4 octets even though its a 2 octets field
  48       u32 frag_id;
  49       // align by making this 4 octets even though its a 1 octet field
  50       u32 proto;
  51       u32 unused;
  52     };
  53     u64 as_u64[6];
  54   };
  55 } ip6_reass_key_t;
  56
  57 always_inline u32
  58 ip6_reass_buffer_get_data_offset_no_check (vlib_buffer_t * b)
  59 {
  60   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  61   return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
  62 }
  63
  64 always_inline u32
  65 ip6_reass_buffer_get_data_offset (vlib_buffer_t * b)
  66 {
  67   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  68   ASSERT (vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first);
  69   return ip6_reass_buffer_get_data_offset_no_check (b);
  70 }
  71
  72 always_inline u16
  73 ip6_reass_buffer_get_data_len_no_check (vlib_buffer_t * b)
  74 {
  75   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  76   return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
  77     (vnb->ip.reass.fragment_first + ip6_reass_buffer_get_data_offset (b)) + 1;
  78 }
  79
  80 always_inline u16
  81 ip6_reass_buffer_get_data_len (vlib_buffer_t * b)
  82 {
  83   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  84   ASSERT (vnb->ip.reass.range_last > vnb->ip.reass.fragment_first);
  85   return ip6_reass_buffer_get_data_len_no_check (b);
  86 }
  87
  88 typedef struct
  89 {
  90   // hash table key
  91   ip6_reass_key_t key;
  92   // time when last packet was received
  93   f64 last_heard;
  94   // internal id of this reassembly
  95   u64 id;
  96   // buffer index of first buffer in this reassembly context
  97   u32 first_bi;
  98   // last octet of packet, ~0 until fragment without more_fragments arrives
  99   u32 last_packet_octet;
 100   // length of data collected so far
 101   u32 data_len;
 102   // trace operation counter
 103   u32 trace_op_counter;
 104   // next index - used by non-feature node
 105   u8 next_index;
 106   // minimum fragment length for this reassembly - used to estimate MTU
 107   u16 min_fragment_length;
 108 } ip6_reass_t;
 109
 110 typedef struct
 111 {
 112   ip6_reass_t *pool;
 113   u32 reass_n;
 114   u32 buffers_n;
 115   u32 id_counter;
 116   clib_spinlock_t lock;
 117 } ip6_reass_per_thread_t;
 118
 119 typedef struct
 120 {
 121   // IPv6 config
 122   u32 timeout_ms;
 123   f64 timeout;
 124   u32 expire_walk_interval_ms;
 125   u32 max_reass_n;
 126
 127   // IPv6 runtime
 128   clib_bihash_48_8_t hash;
 129
 130   // per-thread data
 131   ip6_reass_per_thread_t *per_thread_data;
 132
 133   // convenience
 134   vlib_main_t *vlib_main;
 135   vnet_main_t *vnet_main;
 136
 137   // node index of ip6-drop node
 138   u32 ip6_drop_idx;
 139   u32 ip6_icmp_error_idx;
 140   u32 ip6_reass_expire_node_idx;
 141
 142 } ip6_reass_main_t;
 143
 144 ip6_reass_main_t ip6_reass_main;
 145
 146 typedef enum
 147 {
 148   IP6_REASSEMBLY_NEXT_INPUT,
 149   IP6_REASSEMBLY_NEXT_DROP,
 150   IP6_REASSEMBLY_NEXT_ICMP_ERROR,
 151   IP6_REASSEMBLY_N_NEXT,
 152 } ip6_reass_next_t;
 153
 154 typedef enum
 155 {
 156   RANGE_NEW,
 157   RANGE_OVERLAP,
 158   ICMP_ERROR_RT_EXCEEDED,
 159   ICMP_ERROR_FL_TOO_BIG,
 160   ICMP_ERROR_FL_NOT_MULT_8,
 161   FINALIZE,
 162 } ip6_reass_trace_operation_e;
 163
 164 typedef struct
 165 {
 166   u16 range_first;
 167   u16 range_last;
 168   u32 range_bi;
 169   i32 data_offset;
 170   u32 data_len;
 171   u32 first_bi;
 172 } ip6_reass_range_trace_t;
 173
 174 typedef struct
 175 {
 176   ip6_reass_trace_operation_e action;
 177   u32 reass_id;
 178   ip6_reass_range_trace_t trace_range;
 179   u32 size_diff;
 180   u32 op_id;
 181   u32 fragment_first;
 182   u32 fragment_last;
 183   u32 total_data_len;
 184 } ip6_reass_trace_t;
 185
 186 static void
 187 ip6_reass_trace_details (vlib_main_t * vm, u32 bi,
 188                          ip6_reass_range_trace_t * trace)
 189 {
 190   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 191   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 192   trace->range_first = vnb->ip.reass.range_first;
 193   trace->range_last = vnb->ip.reass.range_last;
 194   trace->data_offset = ip6_reass_buffer_get_data_offset_no_check (b);
 195   trace->data_len = ip6_reass_buffer_get_data_len_no_check (b);
 196   trace->range_bi = bi;
 197 }
 198
 199 static u8 *
 200 format_ip6_reass_range_trace (u8 * s, va_list * args)
 201 {
 202   ip6_reass_range_trace_t *trace = va_arg (*args, ip6_reass_range_trace_t *);
 203   s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
 204               trace->range_last, trace->data_offset, trace->data_len,
 205               trace->range_bi);
 206   return s;
 207 }
 208
 209 static u8 *
 210 format_ip6_reass_trace (u8 * s, va_list * args)
 211 {
 212   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 213   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 214   ip6_reass_trace_t *t = va_arg (*args, ip6_reass_trace_t *);
 215   s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
 216   u32 indent = format_get_indent (s);
 217   s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
 218               t->trace_range.first_bi, t->total_data_len, t->fragment_first,
 219               t->fragment_last);
 220   switch (t->action)
 221     {
 222     case RANGE_NEW:
 223       s = format (s, "\n%Unew %U", format_white_space, indent,
 224                   format_ip6_reass_range_trace, &t->trace_range);
 225       break;
 226     case RANGE_OVERLAP:
 227       s = format (s, "\n%Uoverlap %U", format_white_space, indent,
 228                   format_ip6_reass_range_trace, &t->trace_range);
 229       break;
 230     case ICMP_ERROR_FL_TOO_BIG:
 231       s = format (s, "\n%Uicmp-error - frag_len > 65535 %U",
 232                   format_white_space, indent, format_ip6_reass_range_trace,
 233                   &t->trace_range);
 234       break;
 235     case ICMP_ERROR_FL_NOT_MULT_8:
 236       s = format (s, "\n%Uicmp-error - frag_len mod 8 != 0 %U",
 237                   format_white_space, indent, format_ip6_reass_range_trace,
 238                   &t->trace_range);
 239       break;
 240     case ICMP_ERROR_RT_EXCEEDED:
 241       s = format (s, "\n%Uicmp-error - reassembly time exceeded",
 242                   format_white_space, indent);
 243       break;
 244     case FINALIZE:
 245       s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
 246       break;
 247     }
 248   return s;
 249 }
 250
 251 static void
 252 ip6_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 253                      ip6_reass_main_t * rm, ip6_reass_t * reass,
 254                      u32 bi, ip6_reass_trace_operation_e action,
 255                      u32 size_diff)
 256 {
 257   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 258   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 259   if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
 260     {
 261       // this buffer's trace is gone
 262       b->flags &= ~VLIB_BUFFER_IS_TRACED;
 263       return;
 264     }
 265   ip6_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 266   t->reass_id = reass->id;
 267   t->action = action;
 268   ip6_reass_trace_details (vm, bi, &t->trace_range);
 269   t->size_diff = size_diff;
 270   t->op_id = reass->trace_op_counter;
 271   ++reass->trace_op_counter;
 272   t->fragment_first = vnb->ip.reass.fragment_first;
 273   t->fragment_last = vnb->ip.reass.fragment_last;
 274   t->trace_range.first_bi = reass->first_bi;
 275   t->total_data_len = reass->data_len;
 276 #if 0
 277   static u8 *s = NULL;
 278   s = format (s, "%U", format_ip6_reass_trace, NULL, NULL, t);
 279   printf ("%.*s\n", vec_len (s), s);
 280   fflush (stdout);
 281   vec_reset_length (s);
 282 #endif
 283 }
 284
 285 always_inline void
 286 ip6_reass_free (ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 287                 ip6_reass_t * reass)
 288 {
 289   clib_bihash_kv_48_8_t kv;
 290   kv.key[0] = reass->key.as_u64[0];
 291   kv.key[1] = reass->key.as_u64[1];
 292   kv.key[2] = reass->key.as_u64[2];
 293   kv.key[3] = reass->key.as_u64[3];
 294   kv.key[4] = reass->key.as_u64[4];
 295   kv.key[5] = reass->key.as_u64[5];
 296   clib_bihash_add_del_48_8 (&rm->hash, &kv, 0);
 297   pool_put (rt->pool, reass);
 298   --rt->reass_n;
 299 }
 300
 301 always_inline void
 302 ip6_reass_drop_all (vlib_main_t * vm, ip6_reass_main_t * rm,
 303                     ip6_reass_t * reass, u32 ** vec_drop_bi)
 304 {
 305   u32 range_bi = reass->first_bi;
 306   vlib_buffer_t *range_b;
 307   vnet_buffer_opaque_t *range_vnb;
 308   while (~0 != range_bi)
 309     {
 310       range_b = vlib_get_buffer (vm, range_bi);
 311       range_vnb = vnet_buffer (range_b);
 312       u32 bi = range_bi;
 313       while (~0 != bi)
 314         {
 315           vec_add1 (*vec_drop_bi, bi);
 316           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 317           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 318             {
 319               bi = b->next_buffer;
 320               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 321             }
 322           else
 323             {
 324               bi = ~0;
 325             }
 326         }
 327       range_bi = range_vnb->ip.reass.next_range_bi;
 328     }
 329 }
 330
 331 always_inline void
 332 ip6_reass_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * node,
 333                       ip6_reass_main_t * rm, ip6_reass_t * reass,
 334                       u32 * icmp_bi, u32 ** vec_timeout)
 335 {
 336   if (~0 == reass->first_bi)
 337     {
 338       return;
 339     }
 340   vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
 341   if (0 == vnet_buffer (b)->ip.reass.fragment_first)
 342     {
 343       *icmp_bi = reass->first_bi;
 344       if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
 345         {
 346           ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi,
 347                                ICMP_ERROR_RT_EXCEEDED, 0);
 348         }
 349       // fragment with offset zero received - send icmp message back
 350       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 351         {
 352           // separate first buffer from chain and steer it towards icmp node
 353           b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 354           reass->first_bi = b->next_buffer;
 355         }
 356       else
 357         {
 358           reass->first_bi = vnet_buffer (b)->ip.reass.next_range_bi;
 359         }
 360       icmp6_error_set_vnet_buffer (b, ICMP6_time_exceeded,
 361                                    ICMP6_time_exceeded_fragment_reassembly_time_exceeded,
 362                                    0);
 363     }
 364   ip6_reass_drop_all (vm, rm, reass, vec_timeout);
 365 }
 366
 367 always_inline ip6_reass_t *
 368 ip6_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 369                           ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 370                           ip6_reass_key_t * k, u32 * icmp_bi,
 371                           u32 ** vec_timeout)
 372 {
 373   ip6_reass_t *reass = NULL;
 374   f64 now = vlib_time_now (rm->vlib_main);
 375   clib_bihash_kv_48_8_t kv, value;
 376   kv.key[0] = k->as_u64[0];
 377   kv.key[1] = k->as_u64[1];
 378   kv.key[2] = k->as_u64[2];
 379   kv.key[3] = k->as_u64[3];
 380   kv.key[4] = k->as_u64[4];
 381   kv.key[5] = k->as_u64[5];
 382
 383   if (!clib_bihash_search_48_8 (&rm->hash, &kv, &value))
 384     {
 385       reass = pool_elt_at_index (rt->pool, value.value);
 386       if (now > reass->last_heard + rm->timeout)
 387         {
 388           ip6_reass_on_timeout (vm, node, rm, reass, icmp_bi, vec_timeout);
 389           ip6_reass_free (rm, rt, reass);
 390           reass = NULL;
 391         }
 392     }
 393
 394   if (reass)
 395     {
 396       reass->last_heard = now;
 397       return reass;
 398     }
 399
 400   if (rt->reass_n >= rm->max_reass_n)
 401     {
 402       reass = NULL;
 403       return reass;
 404     }
 405   else
 406     {
 407       pool_get (rt->pool, reass);
 408       memset (reass, 0, sizeof (*reass));
 409       reass->id =
 410         ((u64) os_get_thread_index () * 1000000000) + rt->id_counter;
 411       ++rt->id_counter;
 412       reass->first_bi = ~0;
 413       reass->last_packet_octet = ~0;
 414       reass->data_len = 0;
 415       ++rt->reass_n;
 416     }
 417
 418   reass->key.as_u64[0] = kv.key[0] = k->as_u64[0];
 419   reass->key.as_u64[1] = kv.key[1] = k->as_u64[1];
 420   reass->key.as_u64[2] = kv.key[2] = k->as_u64[2];
 421   reass->key.as_u64[3] = kv.key[3] = k->as_u64[3];
 422   reass->key.as_u64[4] = kv.key[4] = k->as_u64[4];
 423   reass->key.as_u64[5] = kv.key[5] = k->as_u64[5];
 424   kv.value = reass - rt->pool;
 425   reass->last_heard = now;
 426
 427   if (clib_bihash_add_del_48_8 (&rm->hash, &kv, 1))
 428     {
 429       ip6_reass_free (rm, rt, reass);
 430       reass = NULL;
 431     }
 432
 433   return reass;
 434 }
 435
 436 always_inline void
 437 ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 438                     ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 439                     ip6_reass_t * reass, u32 * bi0, u32 * next0,
 440                     vlib_error_t * error0, u32 ** vec_drop_compress,
 441                     bool is_feature)
 442 {
 443   ASSERT (~0 != reass->first_bi);
 444   *bi0 = reass->first_bi;
 445   *error0 = IP6_ERROR_NONE;
 446   ip6_frag_hdr_t *frag_hdr;
 447   vlib_buffer_t *last_b = NULL;
 448   u32 sub_chain_bi = reass->first_bi;
 449   u32 total_length = 0;
 450   u32 buf_cnt = 0;
 451   u32 dropped_cnt = 0;
 452   do
 453     {
 454       u32 tmp_bi = sub_chain_bi;
 455       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 456       u32 data_len = ip6_reass_buffer_get_data_len (tmp);
 457       u32 trim_front = vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 458         sizeof (*frag_hdr) + ip6_reass_buffer_get_data_offset (tmp);
 459       u32 trim_end =
 460         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 461       if (tmp_bi == reass->first_bi)
 462         {
 463           /* first buffer - keep ip6 header */
 464           ASSERT (0 == ip6_reass_buffer_get_data_offset (tmp));
 465           trim_front = 0;
 466           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 467             (vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
 468              sizeof (*frag_hdr));
 469           ASSERT (vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0);
 470         }
 471       u32 keep_data =
 472         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 473       while (1)
 474         {
 475           ++buf_cnt;
 476           if (trim_front)
 477             {
 478               if (trim_front > tmp->current_length)
 479                 {
 480                   /* drop whole buffer */
 481                   vec_add1 (*vec_drop_compress, tmp_bi);
 482                   ++dropped_cnt;
 483                   trim_front -= tmp->current_length;
 484                   ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
 485                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 486                   tmp_bi = tmp->next_buffer;
 487                   tmp = vlib_get_buffer (vm, tmp_bi);
 488                   continue;
 489                 }
 490               else
 491                 {
 492                   vlib_buffer_advance (tmp, trim_front);
 493                   trim_front = 0;
 494                 }
 495             }
 496           if (keep_data)
 497             {
 498               if (last_b)
 499                 {
 500                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 501                   last_b->next_buffer = tmp_bi;
 502                 }
 503               last_b = tmp;
 504               if (keep_data <= tmp->current_length)
 505                 {
 506                   tmp->current_length = keep_data;
 507                   keep_data = 0;
 508                 }
 509               else
 510                 {
 511                   keep_data -= tmp->current_length;
 512                   ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
 513                 }
 514               total_length += tmp->current_length;
 515             }
 516           else
 517             {
 518               vec_add1 (*vec_drop_compress, tmp_bi);
 519               ASSERT (reass->first_bi != tmp_bi);
 520               ++dropped_cnt;
 521             }
 522           if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 523             {
 524               tmp_bi = tmp->next_buffer;
 525               tmp = vlib_get_buffer (vm, tmp->next_buffer);
 526             }
 527           else
 528             {
 529               break;
 530             }
 531         }
 532       sub_chain_bi =
 533         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 534         reass.next_range_bi;
 535     }
 536   while (~0 != sub_chain_bi);
 537
 538   ASSERT (last_b != NULL);
 539   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 540   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 541   ASSERT (total_length >= first_b->current_length);
 542   total_length -= first_b->current_length;
 543   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 544   first_b->total_length_not_including_first_buffer = total_length;
 545   // drop fragment header
 546   vnet_buffer_opaque_t *first_b_vnb = vnet_buffer (first_b);
 547   ip6_header_t *ip = vlib_buffer_get_current (first_b);
 548   u16 ip6_frag_hdr_offset = first_b_vnb->ip.reass.ip6_frag_hdr_offset;
 549   ip6_ext_header_t *prev_hdr;
 550   ip6_ext_header_find_t (ip, prev_hdr, frag_hdr,
 551                          IP_PROTOCOL_IPV6_FRAGMENTATION);
 552   if (prev_hdr)
 553     {
 554       prev_hdr->next_hdr = frag_hdr->next_hdr;
 555     }
 556   else
 557     {
 558       ip->protocol = frag_hdr->next_hdr;
 559     }
 560   ASSERT ((u8 *) frag_hdr - (u8 *) ip == ip6_frag_hdr_offset);
 561   memmove (frag_hdr, (u8 *) frag_hdr + sizeof (*frag_hdr),
 562            first_b->current_length - ip6_frag_hdr_offset -
 563            sizeof (ip6_frag_hdr_t));
 564   first_b->current_length -= sizeof (*frag_hdr);
 565   ip->payload_length =
 566     clib_host_to_net_u16 (total_length + first_b->current_length -
 567                           sizeof (*ip));
 568   vlib_buffer_chain_compress (vm, first_b, vec_drop_compress);
 569   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 570     {
 571       ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 572 #if 0
 573       // following code does a hexdump of packet fragments to stdout ...
 574       do
 575         {
 576           u32 bi = reass->first_bi;
 577           u8 *s = NULL;
 578           while (~0 != bi)
 579             {
 580               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 581               s = format (s, "%u: %U\n", bi, format_hexdump,
 582                           vlib_buffer_get_current (b), b->current_length);
 583               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 584                 {
 585                   bi = b->next_buffer;
 586                 }
 587               else
 588                 {
 589                   break;
 590                 }
 591             }
 592           printf ("%.*s\n", vec_len (s), s);
 593           fflush (stdout);
 594           vec_free (s);
 595         }
 596       while (0);
 597 #endif
 598     }
 599   if (is_feature)
 600     {
 601       *next0 = IP6_REASSEMBLY_NEXT_INPUT;
 602     }
 603   else
 604     {
 605       *next0 = reass->next_index;
 606     }
 607   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 608   ip6_reass_free (rm, rt, reass);
 609   reass = NULL;
 610 }
 611
 612 always_inline u32
 613 ip6_reass_get_buffer_chain_length (vlib_main_t * vm, vlib_buffer_t * b)
 614 {
 615   u32 len = 0;
 616   while (b)
 617     {
 618       ++len;
 619       if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
 620         {
 621           b = vlib_get_buffer (vm, b->next_buffer);
 622         }
 623       else
 624         {
 625           break;
 626         }
 627     }
 628   return len;
 629 }
 630
 631 always_inline void
 632 ip6_reass_insert_range_in_chain (vlib_main_t * vm, ip6_reass_main_t * rm,
 633                                  ip6_reass_per_thread_t * rt,
 634                                  ip6_reass_t * reass, u32 prev_range_bi,
 635                                  u32 new_next_bi)
 636 {
 637
 638   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 639   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 640   if (~0 != prev_range_bi)
 641     {
 642       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 643       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 644       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 645       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 646     }
 647   else
 648     {
 649       if (~0 != reass->first_bi)
 650         {
 651           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 652         }
 653       reass->first_bi = new_next_bi;
 654     }
 655   reass->data_len += ip6_reass_buffer_get_data_len (new_next_b);
 656   rt->buffers_n += ip6_reass_get_buffer_chain_length (vm, new_next_b);
 657 }
 658
 659 always_inline void
 660 ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 661                   ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 662                   ip6_reass_t * reass, u32 * bi0, u32 * next0,
 663                   vlib_error_t * error0, ip6_frag_hdr_t * frag_hdr,
 664                   u32 ** vec_drop_overlap, u32 ** vec_drop_compress,
 665                   bool is_feature)
 666 {
 667   int consumed = 0;
 668   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 669   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 670   fvnb->ip.reass.ip6_frag_hdr_offset =
 671     (u8 *) frag_hdr - (u8 *) vlib_buffer_get_current (fb);
 672   ip6_header_t *fip = vlib_buffer_get_current (fb);
 673   ASSERT (fb->current_length > sizeof (*fip));
 674   ASSERT (fvnb->ip.reass.ip6_frag_hdr_offset > 0 &&
 675           fvnb->ip.reass.ip6_frag_hdr_offset < fb->current_length);
 676   u32 fragment_first = fvnb->ip.reass.fragment_first =
 677     ip6_frag_hdr_offset_bytes (frag_hdr);
 678   u32 fragment_length =
 679     vlib_buffer_length_in_chain (vm, fb) -
 680     (fvnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 681   u32 fragment_last = fvnb->ip.reass.fragment_last =
 682     fragment_first + fragment_length - 1;
 683   int more_fragments = ip6_frag_hdr_more (frag_hdr);
 684   u32 candidate_range_bi = reass->first_bi;
 685   u32 prev_range_bi = ~0;
 686   fvnb->ip.reass.range_first = fragment_first;
 687   fvnb->ip.reass.range_last = fragment_last;
 688   fvnb->ip.reass.next_range_bi = ~0;
 689   if (!more_fragments)
 690     {
 691       reass->last_packet_octet = fragment_last;
 692     }
 693   if (~0 == reass->first_bi)
 694     {
 695       // starting a new reassembly
 696       ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 697                                        *bi0);
 698       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 699         {
 700           ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 701         }
 702       reass->min_fragment_length = clib_net_to_host_u16 (fip->payload_length);
 703       *bi0 = ~0;
 704       return;
 705     }
 706   reass->min_fragment_length =
 707     clib_min (clib_net_to_host_u16 (fip->payload_length),
 708               fvnb->ip.reass.estimated_mtu);
 709   while (~0 != candidate_range_bi)
 710     {
 711       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 712       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 713       if (fragment_first > candidate_vnb->ip.reass.range_last)
 714         {
 715           // this fragments starts after candidate range
 716           prev_range_bi = candidate_range_bi;
 717           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 718           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 719               ~0 == candidate_range_bi)
 720             {
 721               // special case - this fragment falls beyond all known ranges
 722               ip6_reass_insert_range_in_chain (vm, rm, rt, reass,
 723                                                prev_range_bi, *bi0);
 724               consumed = 1;
 725               break;
 726             }
 727           continue;
 728         }
 729       if (fragment_last < candidate_vnb->ip.reass.range_first)
 730         {
 731           // this fragment ends before candidate range without any overlap
 732           ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 733                                            *bi0);
 734           consumed = 1;
 735         }
 736       else if (fragment_first == candidate_vnb->ip.reass.range_first &&
 737                fragment_last == candidate_vnb->ip.reass.range_last)
 738         {
 739           // duplicate fragment - ignore
 740         }
 741       else
 742         {
 743           // overlapping fragment - not allowed by RFC 8200
 744           ip6_reass_drop_all (vm, rm, reass, vec_drop_overlap);
 745           ip6_reass_free (rm, rt, reass);
 746           if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 747             {
 748               ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_OVERLAP,
 749                                    0);
 750             }
 751           *next0 = IP6_REASSEMBLY_NEXT_DROP;
 752           *error0 = IP6_ERROR_REASS_OVERLAPPING_FRAGMENT;
 753         }
 754       break;
 755     }
 756   if (consumed)
 757     {
 758       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 759         {
 760           ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 761         }
 762     }
 763   if (~0 != reass->last_packet_octet &&
 764       reass->data_len == reass->last_packet_octet + 1)
 765     {
 766       ip6_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 767                           vec_drop_compress, is_feature);
 768     }
 769   else
 770     {
 771       if (consumed)
 772         {
 773           *bi0 = ~0;
 774         }
 775       else
 776         {
 777           *next0 = IP6_REASSEMBLY_NEXT_DROP;
 778           ;
 779           *error0 = IP6_ERROR_REASS_DUPLICATE_FRAGMENT;
 780         }
 781     }
 782 }
 783
 784 always_inline bool
 785 ip6_reass_verify_upper_layer_present (vlib_node_runtime_t * node,
 786                                       vlib_buffer_t * b,
 787                                       ip6_frag_hdr_t * frag_hdr)
 788 {
 789   ip6_ext_header_t *tmp = (ip6_ext_header_t *) frag_hdr;
 790   while (ip6_ext_hdr (tmp->next_hdr))
 791     {
 792       tmp = ip6_ext_next_header (tmp);
 793     }
 794   if (IP_PROTOCOL_IP6_NONXT == tmp->next_hdr)
 795     {
 796       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 797                                    ICMP6_parameter_problem_first_fragment_has_incomplete_header_chain,
 798                                    0);
 799       b->error = node->errors[IP6_ERROR_REASS_MISSING_UPPER];
 800
 801       return false;
 802     }
 803   return true;
 804 }
 805
 806 always_inline bool
 807 ip6_reass_verify_fragment_multiple_8 (vlib_main_t * vm,
 808                                       vlib_node_runtime_t * node,
 809                                       vlib_buffer_t * b,
 810                                       ip6_frag_hdr_t * frag_hdr)
 811 {
 812   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 813   ip6_header_t *ip = vlib_buffer_get_current (b);
 814   int more_fragments = ip6_frag_hdr_more (frag_hdr);
 815   u32 fragment_length =
 816     vlib_buffer_length_in_chain (vm, b) -
 817     (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 818   if (more_fragments && 0 != fragment_length % 8)
 819     {
 820       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 821                                    ICMP6_parameter_problem_erroneous_header_field,
 822                                    (u8 *) & ip->payload_length - (u8 *) ip);
 823       return false;
 824     }
 825   return true;
 826 }
 827
 828 always_inline bool
 829 ip6_reass_verify_packet_size_lt_64k (vlib_main_t * vm,
 830                                      vlib_node_runtime_t * node,
 831                                      vlib_buffer_t * b,
 832                                      ip6_frag_hdr_t * frag_hdr)
 833 {
 834   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 835   u32 fragment_first = ip6_frag_hdr_offset_bytes (frag_hdr);
 836   u32 fragment_length =
 837     vlib_buffer_length_in_chain (vm, b) -
 838     (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
 839   if (fragment_first + fragment_length > 65535)
 840     {
 841       ip6_header_t *ip0 = vlib_buffer_get_current (b);
 842       icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
 843                                    ICMP6_parameter_problem_erroneous_header_field,
 844                                    (u8 *) & frag_hdr->fragment_offset_and_more
 845                                    - (u8 *) ip0);
 846       return false;
 847     }
 848   return true;
 849 }
 850
 851 always_inline uword
 852 ip6_reassembly_inline (vlib_main_t * vm,
 853                        vlib_node_runtime_t * node,
 854                        vlib_frame_t * frame, bool is_feature)
 855 {
 856   u32 *from = vlib_frame_vector_args (frame);
 857   u32 n_left_from, n_left_to_next, *to_next, next_index;
 858   ip6_reass_main_t *rm = &ip6_reass_main;
 859   ip6_reass_per_thread_t *rt = &rm->per_thread_data[os_get_thread_index ()];
 860   clib_spinlock_lock (&rt->lock);
 861
 862   n_left_from = frame->n_vectors;
 863   next_index = node->cached_next_index;
 864   static u32 *vec_timeout = NULL;       // indexes of buffers which timed out
 865   static u32 *vec_drop_overlap = NULL;  // indexes of buffers dropped due to overlap
 866   static u32 *vec_drop_compress = NULL; // indexes of buffers dropped due to buffer compression
 867   while (n_left_from > 0 || vec_len (vec_timeout) > 0 ||
 868          vec_len (vec_drop_overlap) > 0 || vec_len (vec_drop_compress) > 0)
 869     {
 870       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 871
 872       while (vec_len (vec_timeout) > 0 && n_left_to_next > 0)
 873         {
 874           u32 bi = vec_pop (vec_timeout);
 875           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 876           b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
 877           to_next[0] = bi;
 878           to_next += 1;
 879           n_left_to_next -= 1;
 880           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 881                                            n_left_to_next, bi,
 882                                            IP6_REASSEMBLY_NEXT_DROP);
 883           ASSERT (rt->buffers_n > 0);
 884           --rt->buffers_n;
 885         }
 886
 887       while (vec_len (vec_drop_overlap) > 0 && n_left_to_next > 0)
 888         {
 889           u32 bi = vec_pop (vec_drop_overlap);
 890           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 891           b->error = node->errors[IP6_ERROR_REASS_OVERLAPPING_FRAGMENT];
 892           to_next[0] = bi;
 893           to_next += 1;
 894           n_left_to_next -= 1;
 895           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 896                                            n_left_to_next, bi,
 897                                            IP6_REASSEMBLY_NEXT_DROP);
 898           ASSERT (rt->buffers_n > 0);
 899           --rt->buffers_n;
 900         }
 901
 902       while (vec_len (vec_drop_compress) > 0 && n_left_to_next > 0)
 903         {
 904           u32 bi = vec_pop (vec_drop_compress);
 905           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 906           b->error = node->errors[IP6_ERROR_NONE];
 907           to_next[0] = bi;
 908           to_next += 1;
 909           n_left_to_next -= 1;
 910           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 911                                            n_left_to_next, bi,
 912                                            IP6_REASSEMBLY_NEXT_DROP);
 913           ASSERT (rt->buffers_n > 0);
 914           --rt->buffers_n;
 915         }
 916
 917       while (n_left_from > 0 && n_left_to_next > 0)
 918         {
 919           u32 bi0;
 920           vlib_buffer_t *b0;
 921           u32 next0;
 922           u32 error0 = IP6_ERROR_NONE;
 923           u32 icmp_bi = ~0;
 924
 925           bi0 = from[0];
 926           b0 = vlib_get_buffer (vm, bi0);
 927
 928           ip6_header_t *ip0 = vlib_buffer_get_current (b0);
 929           ip6_frag_hdr_t *frag_hdr;
 930           ip6_ext_header_t *prev_hdr;
 931           ip6_ext_header_find_t (ip0, prev_hdr, frag_hdr,
 932                                  IP_PROTOCOL_IPV6_FRAGMENTATION);
 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.src.as_u64[0] = ip0->src_address.as_u64[0];
 960           k.src.as_u64[1] = ip0->src_address.as_u64[1];
 961           k.dst.as_u64[0] = ip0->dst_address.as_u64[0];
 962           k.dst.as_u64[1] = ip0->dst_address.as_u64[1];
 963           k.xx_id = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 964           k.frag_id = frag_hdr->identification;
 965           k.proto = ip0->protocol;
 966           k.unused = 0;
 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 (vnet_buffer (b0)->sw_if_index[VLIB_RX],
 994                                      &next0, b0);
 995                 }
 996               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 997                                                n_left_to_next, bi0, next0);
 998             }
 999
1000           if (~0 != icmp_bi)
1001             {
1002               next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
1003               to_next[0] = icmp_bi;
1004               to_next += 1;
1005               n_left_to_next -= 1;
1006               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1007                                                n_left_to_next, icmp_bi,
1008                                                next0);
1009             }
1010           from += 1;
1011           n_left_from -= 1;
1012         }
1013
1014       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1015     }
1016
1017   clib_spinlock_unlock (&rt->lock);
1018   return frame->n_vectors;
1019 }
1020
1021 static char *ip6_reassembly_error_strings[] = {
1022 #define _(sym, string) string,
1023   foreach_ip6_error
1024 #undef _
1025 };
1026
1027 always_inline uword
1028 ip6_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
1029                 vlib_frame_t * frame)
1030 {
1031   return ip6_reassembly_inline (vm, node, frame, false /* is_feature */ );
1032 }
1033
1034 /* *INDENT-OFF* */
1035 VLIB_REGISTER_NODE (ip6_reass_node, static) = {
1036     .function = ip6_reassembly,
1037     .name = "ip6-reassembly",
1038     .vector_size = sizeof (u32),
1039     .format_trace = format_ip6_reass_trace,
1040     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1041     .error_strings = ip6_reassembly_error_strings,
1042     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1043     .next_nodes =
1044         {
1045                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1046                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1047                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1048         },
1049 };
1050 /* *INDENT-ON* */
1051
1052 VLIB_NODE_FUNCTION_MULTIARCH (ip6_reass_node, ip6_reassembly);
1053
1054 always_inline uword
1055 ip6_reassembly_feature (vlib_main_t * vm,
1056                         vlib_node_runtime_t * node, vlib_frame_t * frame)
1057 {
1058   return ip6_reassembly_inline (vm, node, frame, true /* is_feature */ );
1059 }
1060
1061 /* *INDENT-OFF* */
1062 VLIB_REGISTER_NODE (ip6_reass_node_feature, static) = {
1063     .function = ip6_reassembly_feature,
1064     .name = "ip6-reassembly-feature",
1065     .vector_size = sizeof (u32),
1066     .format_trace = format_ip6_reass_trace,
1067     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1068     .error_strings = ip6_reassembly_error_strings,
1069     .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
1070     .next_nodes =
1071         {
1072                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
1073                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
1074                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
1075         },
1076 };
1077 /* *INDENT-ON* */
1078
1079 VLIB_NODE_FUNCTION_MULTIARCH (ip6_reass_node_feature, ip6_reassembly_feature);
1080
1081 /* *INDENT-OFF* */
1082 VNET_FEATURE_INIT (ip6_reassembly_feature, static) = {
1083     .arc_name = "ip6-unicast",
1084     .node_name = "ip6-reassembly-feature",
1085     .runs_before = VNET_FEATURES ("ip6-lookup"),
1086     .runs_after = 0,
1087 };
1088 /* *INDENT-ON* */
1089
1090 static u32
1091 ip6_reass_get_nbuckets ()
1092 {
1093   ip6_reass_main_t *rm = &ip6_reass_main;
1094   u32 nbuckets;
1095   u8 i;
1096
1097   nbuckets = (u32) (rm->max_reass_n / IP6_REASS_HT_LOAD_FACTOR);
1098
1099   for (i = 0; i < 31; i++)
1100     if ((1 << i) >= nbuckets)
1101       break;
1102   nbuckets = 1 << i;
1103
1104   return nbuckets;
1105 }
1106
1107 typedef enum
1108 {
1109   IP6_EVENT_CONFIG_CHANGED = 1,
1110 } ip6_reass_event_t;
1111
1112 typedef struct
1113 {
1114   int failure;
1115   clib_bihash_48_8_t *new_hash;
1116 } ip6_rehash_cb_ctx;
1117
1118 static void
1119 ip6_rehash_cb (clib_bihash_kv_48_8_t * kv, void *_ctx)
1120 {
1121   ip6_rehash_cb_ctx *ctx = _ctx;
1122   if (clib_bihash_add_del_48_8 (ctx->new_hash, kv, 1))
1123     {
1124       ctx->failure = 1;
1125     }
1126 }
1127
1128 static void
1129 ip6_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1130                       u32 expire_walk_interval_ms)
1131 {
1132   ip6_reass_main.timeout_ms = timeout_ms;
1133   ip6_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1134   ip6_reass_main.max_reass_n = max_reassemblies;
1135   ip6_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1136 }
1137
1138 vnet_api_error_t
1139 ip6_reass_set (u32 timeout_ms, u32 max_reassemblies,
1140                u32 expire_walk_interval_ms)
1141 {
1142   u32 old_nbuckets = ip6_reass_get_nbuckets ();
1143   ip6_reass_set_params (timeout_ms, max_reassemblies,
1144                         expire_walk_interval_ms);
1145   vlib_process_signal_event (ip6_reass_main.vlib_main,
1146                              ip6_reass_main.ip6_reass_expire_node_idx,
1147                              IP6_EVENT_CONFIG_CHANGED, 0);
1148   u32 new_nbuckets = ip6_reass_get_nbuckets ();
1149   if (ip6_reass_main.max_reass_n > 0 && new_nbuckets > 1 &&
1150       new_nbuckets != old_nbuckets)
1151     {
1152       clib_bihash_48_8_t new_hash;
1153       memset (&new_hash, 0, sizeof (new_hash));
1154       ip6_rehash_cb_ctx ctx;
1155       ctx.failure = 0;
1156       ctx.new_hash = &new_hash;
1157       clib_bihash_init_48_8 (&new_hash, "ip6-reass", new_nbuckets,
1158                              new_nbuckets * 1024);
1159       clib_bihash_foreach_key_value_pair_48_8 (&ip6_reass_main.hash,
1160                                                ip6_rehash_cb, &ctx);
1161       if (ctx.failure)
1162         {
1163           clib_bihash_free_48_8 (&new_hash);
1164           return -1;
1165         }
1166       else
1167         {
1168           clib_bihash_free_48_8 (&ip6_reass_main.hash);
1169           clib_memcpy (&ip6_reass_main.hash, &new_hash,
1170                        sizeof (ip6_reass_main.hash));
1171         }
1172     }
1173   return 0;
1174 }
1175
1176 vnet_api_error_t
1177 ip6_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1178                u32 * expire_walk_interval_ms)
1179 {
1180   *timeout_ms = ip6_reass_main.timeout_ms;
1181   *max_reassemblies = ip6_reass_main.max_reass_n;
1182   *expire_walk_interval_ms = ip6_reass_main.expire_walk_interval_ms;
1183   return 0;
1184 }
1185
1186 static clib_error_t *
1187 ip6_reass_init_function (vlib_main_t * vm)
1188 {
1189   ip6_reass_main_t *rm = &ip6_reass_main;
1190   clib_error_t *error = 0;
1191   u32 nbuckets;
1192   vlib_node_t *node;
1193
1194   rm->vlib_main = vm;
1195   rm->vnet_main = vnet_get_main ();
1196
1197   vec_validate (rm->per_thread_data, vlib_num_workers () + 1);
1198   ip6_reass_per_thread_t *rt;
1199   vec_foreach (rt, rm->per_thread_data)
1200   {
1201     clib_spinlock_init (&rt->lock);
1202     pool_alloc (rt->pool, rm->max_reass_n);
1203   }
1204
1205   node = vlib_get_node_by_name (vm, (u8 *) "ip6-reassembly-expire-walk");
1206   ASSERT (node);
1207   rm->ip6_reass_expire_node_idx = node->index;
1208
1209   nbuckets = ip6_reass_get_nbuckets ();
1210   clib_bihash_init_48_8 (&rm->hash, "ip6-reass", nbuckets, nbuckets * 1024);
1211
1212   node = vlib_get_node_by_name (vm, (u8 *) "ip6-drop");
1213   ASSERT (node);
1214   rm->ip6_drop_idx = node->index;
1215   node = vlib_get_node_by_name (vm, (u8 *) "ip6-icmp-error");
1216   ASSERT (node);
1217   rm->ip6_icmp_error_idx = node->index;
1218
1219   if ((error = vlib_call_init_function (vm, ip_main_init)))
1220     return error;
1221   ip6_register_protocol (IP_PROTOCOL_IPV6_FRAGMENTATION,
1222                          ip6_reass_node.index);
1223
1224   ip6_reass_set_params (IP6_REASS_TIMEOUT_DEFAULT_MS,
1225                         IP6_REASS_MAX_REASSEMBLIES_DEFAULT,
1226                         IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1227
1228   return error;
1229 }
1230
1231 VLIB_INIT_FUNCTION (ip6_reass_init_function);
1232
1233 static uword
1234 ip6_reass_walk_expired (vlib_main_t * vm,
1235                         vlib_node_runtime_t * node, vlib_frame_t * f)
1236 {
1237   ip6_reass_main_t *rm = &ip6_reass_main;
1238   uword event_type, *event_data = 0;
1239
1240   while (true)
1241     {
1242       vlib_process_wait_for_event_or_clock (vm,
1243                                             (f64) rm->expire_walk_interval_ms
1244                                             / (f64) MSEC_PER_SEC);
1245       event_type = vlib_process_get_events (vm, &event_data);
1246
1247       switch (event_type)
1248         {
1249         case ~0:                /* no events => timeout */
1250           /* nothing to do here */
1251           break;
1252         case IP6_EVENT_CONFIG_CHANGED:
1253           break;
1254         default:
1255           clib_warning ("BUG: event type 0x%wx", event_type);
1256           break;
1257         }
1258       f64 now = vlib_time_now (vm);
1259
1260       ip6_reass_t *reass;
1261       u32 *vec_timeout = NULL;
1262       int *pool_indexes_to_free = NULL;
1263
1264       uword thread_index = 0;
1265       int index;
1266       const uword nthreads = os_get_nthreads ();
1267       u32 *vec_icmp_bi = NULL;
1268       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1269         {
1270           ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1271           clib_spinlock_lock (&rt->lock);
1272
1273           vec_reset_length (pool_indexes_to_free);
1274           /* *INDENT-OFF* */
1275           pool_foreach_index (index, rt->pool, ({
1276                                 reass = pool_elt_at_index (rt->pool, index);
1277                                 if (now > reass->last_heard + rm->timeout)
1278                                   {
1279                                     vec_add1 (pool_indexes_to_free, index);
1280                                   }
1281                               }));
1282           /* *INDENT-ON* */
1283           int *i;
1284           /* *INDENT-OFF* */
1285           vec_foreach (i, pool_indexes_to_free)
1286           {
1287             ip6_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1288             u32 icmp_bi = ~0;
1289             u32 before = vec_len (vec_timeout);
1290             vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
1291             if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1292               {
1293                 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1294                                         b->trace_index))
1295                   {
1296                     /* the trace is gone, don't trace this buffer anymore */
1297                     b->flags &= ~VLIB_BUFFER_IS_TRACED;
1298                   }
1299               }
1300             ip6_reass_on_timeout (vm, node, rm, reass, &icmp_bi, &vec_timeout);
1301             u32 after = vec_len (vec_timeout);
1302             ASSERT (rt->buffers_n >= (after - before));
1303             rt->buffers_n -= (after - before);
1304             if (~0 != icmp_bi)
1305               {
1306                 vec_add1 (vec_icmp_bi, icmp_bi);
1307                 ASSERT (rt->buffers_n > 0);
1308                 --rt->buffers_n;
1309               }
1310             ip6_reass_free (rm, rt, reass);
1311           }
1312           /* *INDENT-ON* */
1313
1314           clib_spinlock_unlock (&rt->lock);
1315         }
1316
1317       while (vec_len (vec_timeout) > 0)
1318         {
1319           vlib_frame_t *f = vlib_get_frame_to_node (vm, rm->ip6_drop_idx);
1320           u32 *to_next = vlib_frame_vector_args (f);
1321           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1322           int trace_frame = 0;
1323           while (vec_len (vec_timeout) > 0 && n_left_to_next > 0)
1324             {
1325               u32 bi = vec_pop (vec_timeout);
1326               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1327               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1328                 {
1329                   if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1330                                           b->trace_index))
1331                     {
1332                       /* the trace is gone, don't trace this buffer anymore */
1333                       b->flags &= ~VLIB_BUFFER_IS_TRACED;
1334                     }
1335                   else
1336                     {
1337                       trace_frame = 1;
1338                     }
1339                 }
1340               b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
1341               to_next[0] = bi;
1342               ++f->n_vectors;
1343               to_next += 1;
1344               n_left_to_next -= 1;
1345             }
1346           f->flags |= (trace_frame * VLIB_FRAME_TRACE);
1347           vlib_put_frame_to_node (vm, rm->ip6_drop_idx, f);
1348         }
1349
1350       while (vec_len (vec_icmp_bi) > 0)
1351         {
1352           vlib_frame_t *f =
1353             vlib_get_frame_to_node (vm, rm->ip6_icmp_error_idx);
1354           u32 *to_next = vlib_frame_vector_args (f);
1355           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1356           int trace_frame = 0;
1357           while (vec_len (vec_icmp_bi) > 0 && n_left_to_next > 0)
1358             {
1359               u32 bi = vec_pop (vec_icmp_bi);
1360               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1361               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1362                 {
1363                   if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1364                                           b->trace_index))
1365                     {
1366                       /* the trace is gone, don't trace this buffer anymore */
1367                       b->flags &= ~VLIB_BUFFER_IS_TRACED;
1368                     }
1369                   else
1370                     {
1371                       trace_frame = 1;
1372                     }
1373                 }
1374               b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
1375               to_next[0] = bi;
1376               ++f->n_vectors;
1377               to_next += 1;
1378               n_left_to_next -= 1;
1379             }
1380           f->flags |= (trace_frame * VLIB_FRAME_TRACE);
1381           vlib_put_frame_to_node (vm, rm->ip6_icmp_error_idx, f);
1382         }
1383
1384       vec_free (pool_indexes_to_free);
1385       vec_free (vec_timeout);
1386       vec_free (vec_icmp_bi);
1387       if (event_data)
1388         {
1389           _vec_len (event_data) = 0;
1390         }
1391     }
1392
1393   return 0;
1394 }
1395
1396 static vlib_node_registration_t ip6_reass_expire_node;
1397
1398 /* *INDENT-OFF* */
1399 VLIB_REGISTER_NODE (ip6_reass_expire_node, static) = {
1400     .function = ip6_reass_walk_expired,
1401     .format_trace = format_ip6_reass_trace,
1402     .type = VLIB_NODE_TYPE_PROCESS,
1403     .name = "ip6-reassembly-expire-walk",
1404
1405     .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
1406     .error_strings = ip6_reassembly_error_strings,
1407
1408 };
1409 /* *INDENT-ON* */
1410
1411 static u8 *
1412 format_ip6_reass_key (u8 * s, va_list * args)
1413 {
1414   ip6_reass_key_t *key = va_arg (*args, ip6_reass_key_t *);
1415   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1416               key->xx_id, format_ip6_address, &key->src, format_ip6_address,
1417               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1418   return s;
1419 }
1420
1421 static u8 *
1422 format_ip6_reass (u8 * s, va_list * args)
1423 {
1424   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1425   ip6_reass_t *reass = va_arg (*args, ip6_reass_t *);
1426
1427   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1428               "last_packet_octet: %u, trace_op_counter: %u\n",
1429               reass->id, format_ip6_reass_key, &reass->key, reass->first_bi,
1430               reass->data_len, reass->last_packet_octet,
1431               reass->trace_op_counter);
1432   u32 bi = reass->first_bi;
1433   u32 counter = 0;
1434   while (~0 != bi)
1435     {
1436       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1437       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1438       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1439                   "fragment[%u, %u]\n",
1440                   counter, vnb->ip.reass.range_first,
1441                   vnb->ip.reass.range_last, bi,
1442                   ip6_reass_buffer_get_data_offset_no_check (b),
1443                   ip6_reass_buffer_get_data_len_no_check (b),
1444                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1445       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1446         {
1447           bi = b->next_buffer;
1448         }
1449       else
1450         {
1451           bi = ~0;
1452         }
1453     }
1454   return s;
1455 }
1456
1457 static clib_error_t *
1458 show_ip6_reass (vlib_main_t * vm, unformat_input_t * input,
1459                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1460 {
1461   ip6_reass_main_t *rm = &ip6_reass_main;
1462
1463   vlib_cli_output (vm, "---------------------");
1464   vlib_cli_output (vm, "IP6 reassembly status");
1465   vlib_cli_output (vm, "---------------------");
1466   bool details = false;
1467   if (unformat (input, "details"))
1468     {
1469       details = true;
1470     }
1471
1472   u32 sum_reass_n = 0;
1473   u64 sum_buffers_n = 0;
1474   ip6_reass_t *reass;
1475   uword thread_index;
1476   const uword nthreads = os_get_nthreads ();
1477   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1478     {
1479       ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1480       clib_spinlock_lock (&rt->lock);
1481       if (details)
1482         {
1483           /* *INDENT-OFF* */
1484           pool_foreach (reass, rt->pool, {
1485             vlib_cli_output (vm, "%U", format_ip6_reass, vm, reass);
1486           });
1487           /* *INDENT-ON* */
1488         }
1489       sum_reass_n += rt->reass_n;
1490       sum_buffers_n += rt->buffers_n;
1491       clib_spinlock_unlock (&rt->lock);
1492     }
1493   vlib_cli_output (vm, "---------------------");
1494   vlib_cli_output (vm, "Current IP6 reassemblies count: %lu\n",
1495                    (long unsigned) sum_reass_n);
1496   vlib_cli_output (vm, "Maximum configured concurrent IP6 reassemblies per "
1497                    "worker-thread: %lu\n", (long unsigned) rm->max_reass_n);
1498   vlib_cli_output (vm, "Buffers in use: %lu\n",
1499                    (long unsigned) sum_buffers_n);
1500   return 0;
1501 }
1502
1503 /* *INDENT-OFF* */
1504 VLIB_CLI_COMMAND (show_ip6_reassembly_cmd, static) = {
1505     .path = "show ip6-reassembly",
1506     .short_help = "show ip6-reassembly [details]",
1507     .function = show_ip6_reass,
1508 };
1509 /* *INDENT-ON* */
1510
1511 vnet_api_error_t
1512 ip6_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1513 {
1514   return vnet_feature_enable_disable ("ip6-unicast", "ip6-reassembly-feature",
1515                                       sw_if_index, enable_disable, 0, 0);
1516 }
1517
1518 /*
1519  * fd.io coding-style-patch-verification: ON
1520  *
1521  * Local Variables:
1522  * eval: (c-set-style "gnu")
1523  * End:
1524  */