src/vnet/ip/ip4_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 IPv4 Reassembly.
  19  *
  20  * This file contains the source code for IPv4 reassembly.
  21  */
  22
  23 #include <vppinfra/vec.h>
  24 #include <vnet/vnet.h>
  25 #include <vnet/ip/ip.h>
  26 #include <vppinfra/bihash_16_8.h>
  27 #include <vnet/ip/ip4_reassembly.h>
  28
  29 #define MSEC_PER_SEC 1000
  30 #define IP4_REASS_TIMEOUT_DEFAULT_MS 100
  31 #define IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000 // 10 seconds default
  32 #define IP4_REASS_MAX_REASSEMBLIES_DEFAULT 1024
  33 #define IP4_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT 3
  34 #define IP4_REASS_HT_LOAD_FACTOR (0.75)
  35
  36 #define IP4_REASS_DEBUG_BUFFERS 0
  37 #if IP4_REASS_DEBUG_BUFFERS
  38 #define IP4_REASS_DEBUG_BUFFER(bi, what)             \
  39   do                                                 \
  40     {                                                \
  41       u32 _bi = bi;                                  \
  42       printf (#what "buffer %u", _bi);               \
  43       vlib_buffer_t *_b = vlib_get_buffer (vm, _bi); \
  44       while (_b->flags & VLIB_BUFFER_NEXT_PRESENT)   \
  45         {                                            \
  46           _bi = _b->next_buffer;                     \
  47           printf ("[%u]", _bi);                      \
  48           _b = vlib_get_buffer (vm, _bi);            \
  49         }                                            \
  50       printf ("\n");                                 \
  51       fflush (stdout);                               \
  52     }                                                \
  53   while (0)
  54 #else
  55 #define IP4_REASS_DEBUG_BUFFER(...)
  56 #endif
  57
  58 typedef enum
  59 {
  60   IP4_REASS_RC_OK,
  61   IP4_REASS_RC_TOO_MANY_FRAGMENTS,
  62   IP4_REASS_RC_INTERNAL_ERROR,
  63   IP4_REASS_RC_NO_BUF,
  64 } ip4_reass_rc_t;
  65
  66 typedef struct
  67 {
  68   union
  69   {
  70     struct
  71     {
  72       u32 xx_id;
  73       ip4_address_t src;
  74       ip4_address_t dst;
  75       u16 frag_id;
  76       u8 proto;
  77       u8 unused;
  78     };
  79     u64 as_u64[2];
  80   };
  81 } ip4_reass_key_t;
  82
  83 typedef union
  84 {
  85   struct
  86   {
  87     u32 reass_index;
  88     u32 thread_index;
  89   };
  90   u64 as_u64;
  91 } ip4_reass_val_t;
  92
  93 typedef union
  94 {
  95   struct
  96   {
  97     ip4_reass_key_t k;
  98     ip4_reass_val_t v;
  99   };
 100   clib_bihash_kv_16_8_t kv;
 101 } ip4_reass_kv_t;
 102
 103 always_inline u32
 104 ip4_reass_buffer_get_data_offset (vlib_buffer_t * b)
 105 {
 106   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 107   return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
 108 }
 109
 110 always_inline u16
 111 ip4_reass_buffer_get_data_len (vlib_buffer_t * b)
 112 {
 113   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 114   return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
 115     (vnb->ip.reass.fragment_first + ip4_reass_buffer_get_data_offset (b)) + 1;
 116 }
 117
 118 typedef struct
 119 {
 120   // hash table key
 121   ip4_reass_key_t key;
 122   // time when last packet was received
 123   f64 last_heard;
 124   // internal id of this reassembly
 125   u64 id;
 126   // buffer index of first buffer in this reassembly context
 127   u32 first_bi;
 128   // last octet of packet, ~0 until fragment without more_fragments arrives
 129   u32 last_packet_octet;
 130   // length of data collected so far
 131   u32 data_len;
 132   // trace operation counter
 133   u32 trace_op_counter;
 134   // next index - used by non-feature node
 135   u32 next_index;
 136   // error next index - used by custom apps (~0 if not used)
 137   u32 error_next_index;
 138   // minimum fragment length for this reassembly - used to estimate MTU
 139   u16 min_fragment_length;
 140   // number of fragments in this reassembly
 141   u32 fragments_n;
 142 } ip4_reass_t;
 143
 144 typedef struct
 145 {
 146   ip4_reass_t *pool;
 147   u32 reass_n;
 148   u32 id_counter;
 149   clib_spinlock_t lock;
 150 } ip4_reass_per_thread_t;
 151
 152 typedef struct
 153 {
 154   // IPv4 config
 155   u32 timeout_ms;
 156   f64 timeout;
 157   u32 expire_walk_interval_ms;
 158   // maximum number of fragments in one reassembly
 159   u32 max_reass_len;
 160   // maximum number of reassemblies
 161   u32 max_reass_n;
 162
 163   // IPv4 runtime
 164   clib_bihash_16_8_t hash;
 165   // per-thread data
 166   ip4_reass_per_thread_t *per_thread_data;
 167
 168   // convenience
 169   vlib_main_t *vlib_main;
 170   vnet_main_t *vnet_main;
 171
 172   // node index of ip4-drop node
 173   u32 ip4_drop_idx;
 174   u32 ip4_reass_expire_node_idx;
 175
 176   /** Worker handoff */
 177   u32 fq_index;
 178   u32 fq_feature_index;
 179
 180 } ip4_reass_main_t;
 181
 182 extern ip4_reass_main_t ip4_reass_main;
 183
 184 #ifndef CLIB_MARCH_VARIANT
 185 ip4_reass_main_t ip4_reass_main;
 186 #endif /* CLIB_MARCH_VARIANT */
 187
 188 typedef enum
 189 {
 190   IP4_REASSEMBLY_NEXT_INPUT,
 191   IP4_REASSEMBLY_NEXT_DROP,
 192   IP4_REASSEMBLY_NEXT_HANDOFF,
 193   IP4_REASSEMBLY_N_NEXT,
 194 } ip4_reass_next_t;
 195
 196 typedef enum
 197 {
 198   RANGE_NEW,
 199   RANGE_SHRINK,
 200   RANGE_DISCARD,
 201   RANGE_OVERLAP,
 202   FINALIZE,
 203 } ip4_reass_trace_operation_e;
 204
 205 typedef struct
 206 {
 207   u16 range_first;
 208   u16 range_last;
 209   u32 range_bi;
 210   i32 data_offset;
 211   u32 data_len;
 212   u32 first_bi;
 213 } ip4_reass_range_trace_t;
 214
 215 typedef struct
 216 {
 217   ip4_reass_trace_operation_e action;
 218   u32 reass_id;
 219   ip4_reass_range_trace_t trace_range;
 220   u32 size_diff;
 221   u32 op_id;
 222   u32 fragment_first;
 223   u32 fragment_last;
 224   u32 total_data_len;
 225 } ip4_reass_trace_t;
 226
 227 extern vlib_node_registration_t ip4_reass_node;
 228 extern vlib_node_registration_t ip4_reass_node_feature;
 229
 230 static void
 231 ip4_reass_trace_details (vlib_main_t * vm, u32 bi,
 232                          ip4_reass_range_trace_t * trace)
 233 {
 234   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 235   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 236   trace->range_first = vnb->ip.reass.range_first;
 237   trace->range_last = vnb->ip.reass.range_last;
 238   trace->data_offset = ip4_reass_buffer_get_data_offset (b);
 239   trace->data_len = ip4_reass_buffer_get_data_len (b);
 240   trace->range_bi = bi;
 241 }
 242
 243 static u8 *
 244 format_ip4_reass_range_trace (u8 * s, va_list * args)
 245 {
 246   ip4_reass_range_trace_t *trace = va_arg (*args, ip4_reass_range_trace_t *);
 247   s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
 248               trace->range_last, trace->data_offset, trace->data_len,
 249               trace->range_bi);
 250   return s;
 251 }
 252
 253 static u8 *
 254 format_ip4_reass_trace (u8 * s, va_list * args)
 255 {
 256   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 257   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 258   ip4_reass_trace_t *t = va_arg (*args, ip4_reass_trace_t *);
 259   s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
 260   u32 indent = format_get_indent (s);
 261   s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
 262               t->trace_range.first_bi, t->total_data_len, t->fragment_first,
 263               t->fragment_last);
 264   switch (t->action)
 265     {
 266     case RANGE_SHRINK:
 267       s = format (s, "\n%Ushrink %U by %u", format_white_space, indent,
 268                   format_ip4_reass_range_trace, &t->trace_range,
 269                   t->size_diff);
 270       break;
 271     case RANGE_DISCARD:
 272       s = format (s, "\n%Udiscard %U", format_white_space, indent,
 273                   format_ip4_reass_range_trace, &t->trace_range);
 274       break;
 275     case RANGE_NEW:
 276       s = format (s, "\n%Unew %U", format_white_space, indent,
 277                   format_ip4_reass_range_trace, &t->trace_range);
 278       break;
 279     case RANGE_OVERLAP:
 280       s = format (s, "\n%Uoverlapping/ignored %U", format_white_space, indent,
 281                   format_ip4_reass_range_trace, &t->trace_range);
 282       break;
 283     case FINALIZE:
 284       s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
 285       break;
 286     }
 287   return s;
 288 }
 289
 290 static void
 291 ip4_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 292                      ip4_reass_main_t * rm, ip4_reass_t * reass, u32 bi,
 293                      ip4_reass_trace_operation_e action, u32 size_diff)
 294 {
 295   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 296   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 297   ip4_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 298   t->reass_id = reass->id;
 299   t->action = action;
 300   ip4_reass_trace_details (vm, bi, &t->trace_range);
 301   t->size_diff = size_diff;
 302   t->op_id = reass->trace_op_counter;
 303   ++reass->trace_op_counter;
 304   t->fragment_first = vnb->ip.reass.fragment_first;
 305   t->fragment_last = vnb->ip.reass.fragment_last;
 306   t->trace_range.first_bi = reass->first_bi;
 307   t->total_data_len = reass->data_len;
 308 #if 0
 309   static u8 *s = NULL;
 310   s = format (s, "%U", format_ip4_reass_trace, NULL, NULL, t);
 311   printf ("%.*s\n", vec_len (s), s);
 312   fflush (stdout);
 313   vec_reset_length (s);
 314 #endif
 315 }
 316
 317
 318 always_inline void
 319 ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 320                 ip4_reass_t * reass)
 321 {
 322   clib_bihash_kv_16_8_t kv;
 323   kv.key[0] = reass->key.as_u64[0];
 324   kv.key[1] = reass->key.as_u64[1];
 325   clib_bihash_add_del_16_8 (&rm->hash, &kv, 0);
 326   pool_put (rt->pool, reass);
 327   --rt->reass_n;
 328 }
 329
 330 always_inline void
 331 ip4_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
 332                     ip4_reass_main_t * rm, ip4_reass_t * reass)
 333 {
 334   u32 range_bi = reass->first_bi;
 335   vlib_buffer_t *range_b;
 336   vnet_buffer_opaque_t *range_vnb;
 337   u32 *to_free = NULL;
 338   while (~0 != range_bi)
 339     {
 340       range_b = vlib_get_buffer (vm, range_bi);
 341       range_vnb = vnet_buffer (range_b);
 342       u32 bi = range_bi;
 343       while (~0 != bi)
 344         {
 345           vec_add1 (to_free, bi);
 346           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 347           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 348             {
 349               bi = b->next_buffer;
 350               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 351             }
 352           else
 353             {
 354               bi = ~0;
 355             }
 356         }
 357       range_bi = range_vnb->ip.reass.next_range_bi;
 358     }
 359   /* send to next_error_index */
 360   if (~0 != reass->error_next_index)
 361     {
 362       u32 n_left_to_next, *to_next, next_index;
 363
 364       next_index = reass->error_next_index;
 365       u32 bi = ~0;
 366
 367       while (vec_len (to_free) > 0)
 368         {
 369           vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 370
 371           while (vec_len (to_free) > 0 && n_left_to_next > 0)
 372             {
 373               bi = vec_pop (to_free);
 374
 375               if (~0 != bi)
 376                 {
 377                   to_next[0] = bi;
 378                   to_next += 1;
 379                   n_left_to_next -= 1;
 380                   vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 381                                                    to_next, n_left_to_next,
 382                                                    bi, next_index);
 383                 }
 384             }
 385           vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 386         }
 387     }
 388   else
 389     {
 390       vlib_buffer_free (vm, to_free, vec_len (to_free));
 391     }
 392 }
 393
 394 static ip4_reass_t *
 395 ip4_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 396                           ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 397                           ip4_reass_kv_t * kv, u8 * do_handoff)
 398 {
 399   ip4_reass_t *reass = NULL;
 400   f64 now = vlib_time_now (rm->vlib_main);
 401
 402   if (!clib_bihash_search_16_8
 403       (&rm->hash, (clib_bihash_kv_16_8_t *) kv, (clib_bihash_kv_16_8_t *) kv))
 404     {
 405       if (vm->thread_index != kv->v.thread_index)
 406         {
 407           *do_handoff = 1;
 408           return NULL;
 409         }
 410       reass = pool_elt_at_index (rt->pool, kv->v.reass_index);
 411
 412       if (now > reass->last_heard + rm->timeout)
 413         {
 414           ip4_reass_drop_all (vm, node, rm, reass);
 415           ip4_reass_free (rm, rt, reass);
 416           reass = NULL;
 417         }
 418     }
 419
 420   if (reass)
 421     {
 422       reass->last_heard = now;
 423       return reass;
 424     }
 425
 426   if (rt->reass_n >= rm->max_reass_n)
 427     {
 428       reass = NULL;
 429       return reass;
 430     }
 431   else
 432     {
 433       pool_get (rt->pool, reass);
 434       clib_memset (reass, 0, sizeof (*reass));
 435       reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter;
 436       ++rt->id_counter;
 437       reass->first_bi = ~0;
 438       reass->last_packet_octet = ~0;
 439       reass->data_len = 0;
 440       reass->next_index = ~0;
 441       reass->error_next_index = ~0;
 442       ++rt->reass_n;
 443     }
 444
 445   reass->key.as_u64[0] = ((clib_bihash_kv_16_8_t *) kv)->key[0];
 446   reass->key.as_u64[1] = ((clib_bihash_kv_16_8_t *) kv)->key[1];
 447   kv->v.reass_index = (reass - rt->pool);
 448   kv->v.thread_index = vm->thread_index;
 449   reass->last_heard = now;
 450
 451   if (clib_bihash_add_del_16_8 (&rm->hash, (clib_bihash_kv_16_8_t *) kv, 1))
 452     {
 453       ip4_reass_free (rm, rt, reass);
 454       reass = NULL;
 455     }
 456
 457   return reass;
 458 }
 459
 460 always_inline ip4_reass_rc_t
 461 ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 462                     ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 463                     ip4_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 464                     bool is_custom_app)
 465 {
 466   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 467   vlib_buffer_t *last_b = NULL;
 468   u32 sub_chain_bi = reass->first_bi;
 469   u32 total_length = 0;
 470   u32 buf_cnt = 0;
 471   do
 472     {
 473       u32 tmp_bi = sub_chain_bi;
 474       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 475       ip4_header_t *ip = vlib_buffer_get_current (tmp);
 476       vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
 477       if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 478           !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 479         {
 480           return IP4_REASS_RC_INTERNAL_ERROR;
 481         }
 482
 483       u32 data_len = ip4_reass_buffer_get_data_len (tmp);
 484       u32 trim_front =
 485         ip4_header_bytes (ip) + ip4_reass_buffer_get_data_offset (tmp);
 486       u32 trim_end =
 487         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 488       if (tmp_bi == reass->first_bi)
 489         {
 490           /* first buffer - keep ip4 header */
 491           if (0 != ip4_reass_buffer_get_data_offset (tmp))
 492             {
 493               return IP4_REASS_RC_INTERNAL_ERROR;
 494             }
 495           trim_front = 0;
 496           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 497             ip4_header_bytes (ip);
 498           if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
 499             {
 500               return IP4_REASS_RC_INTERNAL_ERROR;
 501             }
 502         }
 503       u32 keep_data =
 504         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 505       while (1)
 506         {
 507           ++buf_cnt;
 508           if (trim_front)
 509             {
 510               if (trim_front > tmp->current_length)
 511                 {
 512                   /* drop whole buffer */
 513                   u32 to_be_freed_bi = tmp_bi;
 514                   trim_front -= tmp->current_length;
 515                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 516                     {
 517                       return IP4_REASS_RC_INTERNAL_ERROR;
 518                     }
 519                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 520                   tmp_bi = tmp->next_buffer;
 521                   tmp->next_buffer = 0;
 522                   tmp = vlib_get_buffer (vm, tmp_bi);
 523                   vlib_buffer_free_one (vm, to_be_freed_bi);
 524                   continue;
 525                 }
 526               else
 527                 {
 528                   vlib_buffer_advance (tmp, trim_front);
 529                   trim_front = 0;
 530                 }
 531             }
 532           if (keep_data)
 533             {
 534               if (last_b)
 535                 {
 536                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 537                   last_b->next_buffer = tmp_bi;
 538                 }
 539               last_b = tmp;
 540               if (keep_data <= tmp->current_length)
 541                 {
 542                   tmp->current_length = keep_data;
 543                   keep_data = 0;
 544                 }
 545               else
 546                 {
 547                   keep_data -= tmp->current_length;
 548                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 549                     {
 550                       return IP4_REASS_RC_INTERNAL_ERROR;
 551                     }
 552                 }
 553               total_length += tmp->current_length;
 554               if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 555                 {
 556                   tmp_bi = tmp->next_buffer;
 557                   tmp = vlib_get_buffer (vm, tmp->next_buffer);
 558                 }
 559               else
 560                 {
 561                   break;
 562                 }
 563             }
 564           else
 565             {
 566               u32 to_be_freed_bi = tmp_bi;
 567               if (reass->first_bi == tmp_bi)
 568                 {
 569                   return IP4_REASS_RC_INTERNAL_ERROR;
 570                 }
 571               if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 572                 {
 573                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 574                   tmp_bi = tmp->next_buffer;
 575                   tmp->next_buffer = 0;
 576                   tmp = vlib_get_buffer (vm, tmp_bi);
 577                   vlib_buffer_free_one (vm, to_be_freed_bi);
 578                 }
 579               else
 580                 {
 581                   tmp->next_buffer = 0;
 582                   vlib_buffer_free_one (vm, to_be_freed_bi);
 583                   break;
 584                 }
 585             }
 586         }
 587       sub_chain_bi =
 588         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 589         reass.next_range_bi;
 590     }
 591   while (~0 != sub_chain_bi);
 592
 593   if (!last_b)
 594     {
 595       return IP4_REASS_RC_INTERNAL_ERROR;
 596     }
 597   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 598
 599   if (total_length < first_b->current_length)
 600     {
 601       return IP4_REASS_RC_INTERNAL_ERROR;
 602     }
 603   total_length -= first_b->current_length;
 604   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 605   first_b->total_length_not_including_first_buffer = total_length;
 606   ip4_header_t *ip = vlib_buffer_get_current (first_b);
 607   ip->flags_and_fragment_offset = 0;
 608   ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
 609   ip->checksum = ip4_header_checksum (ip);
 610   if (!vlib_buffer_chain_linearize (vm, first_b))
 611     {
 612       return IP4_REASS_RC_NO_BUF;
 613     }
 614   // reset to reconstruct the mbuf linking
 615   first_b->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
 616   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 617     {
 618       ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 619 #if 0
 620       // following code does a hexdump of packet fragments to stdout ...
 621       do
 622         {
 623           u32 bi = reass->first_bi;
 624           u8 *s = NULL;
 625           while (~0 != bi)
 626             {
 627               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 628               s = format (s, "%u: %U\n", bi, format_hexdump,
 629                           vlib_buffer_get_current (b), b->current_length);
 630               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 631                 {
 632                   bi = b->next_buffer;
 633                 }
 634               else
 635                 {
 636                   break;
 637                 }
 638             }
 639           printf ("%.*s\n", vec_len (s), s);
 640           fflush (stdout);
 641           vec_free (s);
 642         }
 643       while (0);
 644 #endif
 645     }
 646   *bi0 = reass->first_bi;
 647   if (!is_custom_app)
 648     {
 649       *next0 = IP4_REASSEMBLY_NEXT_INPUT;
 650     }
 651   else
 652     {
 653       *next0 = reass->next_index;
 654     }
 655   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 656   *error0 = IP4_ERROR_NONE;
 657   ip4_reass_free (rm, rt, reass);
 658   reass = NULL;
 659   return IP4_REASS_RC_OK;
 660 }
 661
 662 always_inline ip4_reass_rc_t
 663 ip4_reass_insert_range_in_chain (vlib_main_t * vm,
 664                                  ip4_reass_main_t * rm,
 665                                  ip4_reass_per_thread_t * rt,
 666                                  ip4_reass_t * reass,
 667                                  u32 prev_range_bi, u32 new_next_bi)
 668 {
 669   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 670   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 671   if (~0 != prev_range_bi)
 672     {
 673       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 674       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 675       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 676       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 677     }
 678   else
 679     {
 680       if (~0 != reass->first_bi)
 681         {
 682           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 683         }
 684       reass->first_bi = new_next_bi;
 685     }
 686   vnet_buffer_opaque_t *vnb = vnet_buffer (new_next_b);
 687   if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 688       !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 689     {
 690       return IP4_REASS_RC_INTERNAL_ERROR;
 691     }
 692   reass->data_len += ip4_reass_buffer_get_data_len (new_next_b);
 693   return IP4_REASS_RC_OK;
 694 }
 695
 696 always_inline ip4_reass_rc_t
 697 ip4_reass_remove_range_from_chain (vlib_main_t * vm,
 698                                    vlib_node_runtime_t * node,
 699                                    ip4_reass_main_t * rm,
 700                                    ip4_reass_t * reass, u32 prev_range_bi,
 701                                    u32 discard_bi)
 702 {
 703   vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi);
 704   vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b);
 705   if (~0 != prev_range_bi)
 706     {
 707       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 708       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 709       if (!(prev_vnb->ip.reass.next_range_bi == discard_bi))
 710         {
 711           return IP4_REASS_RC_INTERNAL_ERROR;
 712         }
 713       prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi;
 714     }
 715   else
 716     {
 717       reass->first_bi = discard_vnb->ip.reass.next_range_bi;
 718     }
 719   vnet_buffer_opaque_t *vnb = vnet_buffer (discard_b);
 720   if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 721       !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 722     {
 723       return IP4_REASS_RC_INTERNAL_ERROR;
 724     }
 725   reass->data_len -= ip4_reass_buffer_get_data_len (discard_b);
 726   while (1)
 727     {
 728       u32 to_be_freed_bi = discard_bi;
 729       if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED))
 730         {
 731           ip4_reass_add_trace (vm, node, rm, reass, discard_bi, RANGE_DISCARD,
 732                                0);
 733         }
 734       if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT)
 735         {
 736           discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 737           discard_bi = discard_b->next_buffer;
 738           discard_b->next_buffer = 0;
 739           discard_b = vlib_get_buffer (vm, discard_bi);
 740           vlib_buffer_free_one (vm, to_be_freed_bi);
 741         }
 742       else
 743         {
 744           discard_b->next_buffer = 0;
 745           vlib_buffer_free_one (vm, to_be_freed_bi);
 746           break;
 747         }
 748     }
 749   return IP4_REASS_RC_OK;
 750 }
 751
 752 always_inline ip4_reass_rc_t
 753 ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 754                   ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 755                   ip4_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 756                   bool is_custom_app)
 757 {
 758   ip4_reass_rc_t rc = IP4_REASS_RC_OK;
 759   int consumed = 0;
 760   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 761   ip4_header_t *fip = vlib_buffer_get_current (fb);
 762   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 763   if (is_custom_app)
 764     {
 765       // store (error_)next_index before it's overwritten
 766       reass->next_index = fvnb->ip.reass.next_index;
 767       reass->error_next_index = fvnb->ip.reass.error_next_index;
 768     }
 769   const u32 fragment_first = ip4_get_fragment_offset_bytes (fip);
 770   const u32 fragment_length =
 771     clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
 772   const u32 fragment_last = fragment_first + fragment_length - 1;
 773   fvnb->ip.reass.fragment_first = fragment_first;
 774   fvnb->ip.reass.fragment_last = fragment_last;
 775   int more_fragments = ip4_get_fragment_more (fip);
 776   u32 candidate_range_bi = reass->first_bi;
 777   u32 prev_range_bi = ~0;
 778   fvnb->ip.reass.range_first = fragment_first;
 779   fvnb->ip.reass.range_last = fragment_last;
 780   fvnb->ip.reass.next_range_bi = ~0;
 781   if (!more_fragments)
 782     {
 783       reass->last_packet_octet = fragment_last;
 784     }
 785   if (~0 == reass->first_bi)
 786     {
 787       // starting a new reassembly
 788       rc =
 789         ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 790                                          *bi0);
 791       if (IP4_REASS_RC_OK != rc)
 792         {
 793           return rc;
 794         }
 795       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 796         {
 797           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 798         }
 799       *bi0 = ~0;
 800       reass->min_fragment_length = clib_net_to_host_u16 (fip->length);
 801       reass->fragments_n = 1;
 802       return IP4_REASS_RC_OK;
 803     }
 804   reass->min_fragment_length = clib_min (clib_net_to_host_u16 (fip->length),
 805                                          fvnb->ip.reass.estimated_mtu);
 806   while (~0 != candidate_range_bi)
 807     {
 808       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 809       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 810       if (fragment_first > candidate_vnb->ip.reass.range_last)
 811         {
 812           // this fragments starts after candidate range
 813           prev_range_bi = candidate_range_bi;
 814           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 815           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 816               ~0 == candidate_range_bi)
 817             {
 818               // special case - this fragment falls beyond all known ranges
 819               rc =
 820                 ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 821                                                  prev_range_bi, *bi0);
 822               if (IP4_REASS_RC_OK != rc)
 823                 {
 824                   return rc;
 825                 }
 826               consumed = 1;
 827               break;
 828             }
 829           continue;
 830         }
 831       if (fragment_last < candidate_vnb->ip.reass.range_first)
 832         {
 833           // this fragment ends before candidate range without any overlap
 834           rc =
 835             ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 836                                              *bi0);
 837           if (IP4_REASS_RC_OK != rc)
 838             {
 839               return rc;
 840             }
 841           consumed = 1;
 842         }
 843       else
 844         {
 845           if (fragment_first >= candidate_vnb->ip.reass.range_first &&
 846               fragment_last <= candidate_vnb->ip.reass.range_last)
 847             {
 848               // this fragment is a (sub)part of existing range, ignore it
 849               if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 850                 {
 851                   ip4_reass_add_trace (vm, node, rm, reass, *bi0,
 852                                        RANGE_OVERLAP, 0);
 853                 }
 854               break;
 855             }
 856           int discard_candidate = 0;
 857           if (fragment_first < candidate_vnb->ip.reass.range_first)
 858             {
 859               u32 overlap =
 860                 fragment_last - candidate_vnb->ip.reass.range_first + 1;
 861               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 862                 {
 863                   candidate_vnb->ip.reass.range_first += overlap;
 864                   if (reass->data_len < overlap)
 865                     {
 866                       return IP4_REASS_RC_INTERNAL_ERROR;
 867                     }
 868                   reass->data_len -= overlap;
 869                   if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 870                     {
 871                       ip4_reass_add_trace (vm, node, rm, reass,
 872                                            candidate_range_bi, RANGE_SHRINK,
 873                                            overlap);
 874                     }
 875                   rc =
 876                     ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 877                                                      prev_range_bi, *bi0);
 878                   if (IP4_REASS_RC_OK != rc)
 879                     {
 880                       return rc;
 881                     }
 882                   consumed = 1;
 883                 }
 884               else
 885                 {
 886                   discard_candidate = 1;
 887                 }
 888             }
 889           else if (fragment_last > candidate_vnb->ip.reass.range_last)
 890             {
 891               u32 overlap =
 892                 candidate_vnb->ip.reass.range_last - fragment_first + 1;
 893               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 894                 {
 895                   fvnb->ip.reass.range_first += overlap;
 896                   if (~0 != candidate_vnb->ip.reass.next_range_bi)
 897                     {
 898                       prev_range_bi = candidate_range_bi;
 899                       candidate_range_bi =
 900                         candidate_vnb->ip.reass.next_range_bi;
 901                       continue;
 902                     }
 903                   else
 904                     {
 905                       // special case - last range discarded
 906                       rc =
 907                         ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 908                                                          candidate_range_bi,
 909                                                          *bi0);
 910                       if (IP4_REASS_RC_OK != rc)
 911                         {
 912                           return rc;
 913                         }
 914                       consumed = 1;
 915                     }
 916                 }
 917               else
 918                 {
 919                   discard_candidate = 1;
 920                 }
 921             }
 922           else
 923             {
 924               discard_candidate = 1;
 925             }
 926           if (discard_candidate)
 927             {
 928               u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi;
 929               // discard candidate range, probe next range
 930               rc =
 931                 ip4_reass_remove_range_from_chain (vm, node, rm, reass,
 932                                                    prev_range_bi,
 933                                                    candidate_range_bi);
 934               if (IP4_REASS_RC_OK != rc)
 935                 {
 936                   return rc;
 937                 }
 938               if (~0 != next_range_bi)
 939                 {
 940                   candidate_range_bi = next_range_bi;
 941                   continue;
 942                 }
 943               else
 944                 {
 945                   // special case - last range discarded
 946                   rc =
 947                     ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 948                                                      prev_range_bi, *bi0);
 949                   if (IP4_REASS_RC_OK != rc)
 950                     {
 951                       return rc;
 952                     }
 953                   consumed = 1;
 954                 }
 955             }
 956         }
 957       break;
 958     }
 959   ++reass->fragments_n;
 960   if (consumed)
 961     {
 962       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 963         {
 964           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 965         }
 966     }
 967   if (~0 != reass->last_packet_octet &&
 968       reass->data_len == reass->last_packet_octet + 1)
 969     {
 970       return ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 971                                  is_custom_app);
 972     }
 973   else
 974     {
 975       if (consumed)
 976         {
 977           *bi0 = ~0;
 978           if (reass->fragments_n > rm->max_reass_len)
 979             {
 980               rc = IP4_REASS_RC_TOO_MANY_FRAGMENTS;
 981             }
 982         }
 983       else
 984         {
 985           *next0 = IP4_REASSEMBLY_NEXT_DROP;
 986           *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT;
 987         }
 988     }
 989   return rc;
 990 }
 991
 992 always_inline uword
 993 ip4_reassembly_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 994                        vlib_frame_t * frame, bool is_feature,
 995                        bool is_custom_app)
 996 {
 997   u32 *from = vlib_frame_vector_args (frame);
 998   u32 n_left_from, n_left_to_next, *to_next, next_index;
 999   ip4_reass_main_t *rm = &ip4_reass_main;
1000   ip4_reass_per_thread_t *rt = &rm->per_thread_data[vm->thread_index];
1001   clib_spinlock_lock (&rt->lock);
1002
1003   n_left_from = frame->n_vectors;
1004   next_index = node->cached_next_index;
1005   while (n_left_from > 0)
1006     {
1007       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1008
1009       while (n_left_from > 0 && n_left_to_next > 0)
1010         {
1011           u32 bi0;
1012           vlib_buffer_t *b0;
1013           u32 next0;
1014           u32 error0 = IP4_ERROR_NONE;
1015
1016           bi0 = from[0];
1017           b0 = vlib_get_buffer (vm, bi0);
1018
1019           ip4_header_t *ip0 = vlib_buffer_get_current (b0);
1020           if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
1021             {
1022               // this is a whole packet - no fragmentation
1023               if (!is_custom_app)
1024                 {
1025                   next0 = IP4_REASSEMBLY_NEXT_INPUT;
1026                 }
1027               else
1028                 {
1029                   next0 = vnet_buffer (b0)->ip.reass.next_index;
1030                 }
1031             }
1032           else
1033             {
1034               const u32 fragment_first = ip4_get_fragment_offset_bytes (ip0);
1035               const u32 fragment_length =
1036                 clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0);
1037               const u32 fragment_last = fragment_first + fragment_length - 1;
1038               if (fragment_first > fragment_last || fragment_first + fragment_length > UINT16_MAX - 20 || (fragment_length < 8 && ip4_get_fragment_more (ip0))) // 8 is minimum frag length per RFC 791
1039                 {
1040                   next0 = IP4_REASSEMBLY_NEXT_DROP;
1041                   error0 = IP4_ERROR_REASS_MALFORMED_PACKET;
1042                 }
1043               else
1044                 {
1045                   ip4_reass_kv_t kv;
1046                   u8 do_handoff = 0;
1047
1048                   kv.k.as_u64[0] =
1049                     (u64) vec_elt (ip4_main.fib_index_by_sw_if_index,
1050                                    vnet_buffer (b0)->sw_if_index[VLIB_RX]) |
1051                     (u64) ip0->src_address.as_u32 << 32;
1052                   kv.k.as_u64[1] =
1053                     (u64) ip0->dst_address.as_u32 |
1054                     (u64) ip0->fragment_id << 32 | (u64) ip0->protocol << 48;
1055
1056                   ip4_reass_t *reass =
1057                     ip4_reass_find_or_create (vm, node, rm, rt, &kv,
1058                                               &do_handoff);
1059
1060                   if (PREDICT_FALSE (do_handoff))
1061                     {
1062                       next0 = IP4_REASSEMBLY_NEXT_HANDOFF;
1063                       if (is_feature)
1064                         vnet_buffer (b0)->ip.
1065                           reass.owner_feature_thread_index =
1066                           kv.v.thread_index;
1067                       else
1068                         vnet_buffer (b0)->ip.reass.owner_thread_index =
1069                           kv.v.thread_index;
1070                     }
1071                   else if (reass)
1072                     {
1073                       switch (ip4_reass_update
1074                               (vm, node, rm, rt, reass, &bi0, &next0,
1075                                &error0, is_custom_app))
1076                         {
1077                         case IP4_REASS_RC_OK:
1078                           /* nothing to do here */
1079                           break;
1080                         case IP4_REASS_RC_TOO_MANY_FRAGMENTS:
1081                           vlib_node_increment_counter (vm, node->node_index,
1082                                                        IP4_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
1083                                                        1);
1084                           ip4_reass_drop_all (vm, node, rm, reass);
1085                           ip4_reass_free (rm, rt, reass);
1086                           goto next_packet;
1087                           break;
1088                         case IP4_REASS_RC_NO_BUF:
1089                           vlib_node_increment_counter (vm, node->node_index,
1090                                                        IP4_ERROR_REASS_NO_BUF,
1091                                                        1);
1092                           ip4_reass_drop_all (vm, node, rm, reass);
1093                           ip4_reass_free (rm, rt, reass);
1094                           goto next_packet;
1095                           break;
1096                         case IP4_REASS_RC_INTERNAL_ERROR:
1097                           /* drop everything and start with a clean slate */
1098                           vlib_node_increment_counter (vm, node->node_index,
1099                                                        IP4_ERROR_REASS_INTERNAL_ERROR,
1100                                                        1);
1101                           ip4_reass_drop_all (vm, node, rm, reass);
1102                           ip4_reass_free (rm, rt, reass);
1103                           goto next_packet;
1104                           break;
1105                         }
1106                     }
1107                   else
1108                     {
1109                       next0 = IP4_REASSEMBLY_NEXT_DROP;
1110                       error0 = IP4_ERROR_REASS_LIMIT_REACHED;
1111                     }
1112                 }
1113
1114               b0->error = node->errors[error0];
1115             }
1116
1117           if (bi0 != ~0)
1118             {
1119               to_next[0] = bi0;
1120               to_next += 1;
1121               n_left_to_next -= 1;
1122               if (is_feature && IP4_ERROR_NONE == error0)
1123                 {
1124                   b0 = vlib_get_buffer (vm, bi0);
1125                   vnet_feature_next (&next0, b0);
1126                 }
1127               vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1128                                                to_next, n_left_to_next,
1129                                                bi0, next0);
1130               IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next);
1131             }
1132
1133         next_packet:
1134           from += 1;
1135           n_left_from -= 1;
1136         }
1137
1138       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1139     }
1140
1141   clib_spinlock_unlock (&rt->lock);
1142   return frame->n_vectors;
1143 }
1144
1145 static char *ip4_reassembly_error_strings[] = {
1146 #define _(sym, string) string,
1147   foreach_ip4_error
1148 #undef _
1149 };
1150
1151 VLIB_NODE_FN (ip4_reass_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
1152                                vlib_frame_t * frame)
1153 {
1154   return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ ,
1155                                 false /* is_custom_app */ );
1156 }
1157
1158 /* *INDENT-OFF* */
1159 VLIB_REGISTER_NODE (ip4_reass_node) = {
1160     .name = "ip4-reassembly",
1161     .vector_size = sizeof (u32),
1162     .format_trace = format_ip4_reass_trace,
1163     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1164     .error_strings = ip4_reassembly_error_strings,
1165     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1166     .next_nodes =
1167         {
1168                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1169                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1170                 [IP4_REASSEMBLY_NEXT_HANDOFF] = "ip4-reassembly-handoff",
1171
1172         },
1173 };
1174 /* *INDENT-ON* */
1175
1176 VLIB_NODE_FN (ip4_reass_node_feature) (vlib_main_t * vm,
1177                                        vlib_node_runtime_t * node,
1178                                        vlib_frame_t * frame)
1179 {
1180   return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ ,
1181                                 false /* is_custom_app */ );
1182 }
1183
1184 /* *INDENT-OFF* */
1185 VLIB_REGISTER_NODE (ip4_reass_node_feature) = {
1186     .name = "ip4-reassembly-feature",
1187     .vector_size = sizeof (u32),
1188     .format_trace = format_ip4_reass_trace,
1189     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1190     .error_strings = ip4_reassembly_error_strings,
1191     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1192     .next_nodes =
1193         {
1194                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1195                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1196                 [IP4_REASSEMBLY_NEXT_HANDOFF] = "ip4-reass-feature-hoff",
1197         },
1198 };
1199 /* *INDENT-ON* */
1200
1201 /* *INDENT-OFF* */
1202 VNET_FEATURE_INIT (ip4_reassembly_feature, static) = {
1203     .arc_name = "ip4-unicast",
1204     .node_name = "ip4-reassembly-feature",
1205     .runs_before = VNET_FEATURES ("ip4-lookup"),
1206     .runs_after = 0,
1207 };
1208 /* *INDENT-ON* */
1209
1210 #ifndef CLIB_MARCH_VARIANT
1211 always_inline u32
1212 ip4_reass_get_nbuckets ()
1213 {
1214   ip4_reass_main_t *rm = &ip4_reass_main;
1215   u32 nbuckets;
1216   u8 i;
1217
1218   nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR);
1219
1220   for (i = 0; i < 31; i++)
1221     if ((1 << i) >= nbuckets)
1222       break;
1223   nbuckets = 1 << i;
1224
1225   return nbuckets;
1226 }
1227 #endif /* CLIB_MARCH_VARIANT */
1228
1229 typedef enum
1230 {
1231   IP4_EVENT_CONFIG_CHANGED = 1,
1232 } ip4_reass_event_t;
1233
1234 typedef struct
1235 {
1236   int failure;
1237   clib_bihash_16_8_t *new_hash;
1238 } ip4_rehash_cb_ctx;
1239
1240 #ifndef CLIB_MARCH_VARIANT
1241 static void
1242 ip4_rehash_cb (clib_bihash_kv_16_8_t * kv, void *_ctx)
1243 {
1244   ip4_rehash_cb_ctx *ctx = _ctx;
1245   if (clib_bihash_add_del_16_8 (ctx->new_hash, kv, 1))
1246     {
1247       ctx->failure = 1;
1248     }
1249 }
1250
1251 static void
1252 ip4_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1253                       u32 max_reassembly_length, u32 expire_walk_interval_ms)
1254 {
1255   ip4_reass_main.timeout_ms = timeout_ms;
1256   ip4_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1257   ip4_reass_main.max_reass_n = max_reassemblies;
1258   ip4_reass_main.max_reass_len = max_reassembly_length;
1259   ip4_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1260 }
1261
1262 vnet_api_error_t
1263 ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
1264                u32 max_reassembly_length, u32 expire_walk_interval_ms)
1265 {
1266   u32 old_nbuckets = ip4_reass_get_nbuckets ();
1267   ip4_reass_set_params (timeout_ms, max_reassemblies, max_reassembly_length,
1268                         expire_walk_interval_ms);
1269   vlib_process_signal_event (ip4_reass_main.vlib_main,
1270                              ip4_reass_main.ip4_reass_expire_node_idx,
1271                              IP4_EVENT_CONFIG_CHANGED, 0);
1272   u32 new_nbuckets = ip4_reass_get_nbuckets ();
1273   if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1274     {
1275       clib_bihash_16_8_t new_hash;
1276       clib_memset (&new_hash, 0, sizeof (new_hash));
1277       ip4_rehash_cb_ctx ctx;
1278       ctx.failure = 0;
1279       ctx.new_hash = &new_hash;
1280       clib_bihash_init_16_8 (&new_hash, "ip4-reass", new_nbuckets,
1281                              new_nbuckets * 1024);
1282       clib_bihash_foreach_key_value_pair_16_8 (&ip4_reass_main.hash,
1283                                                ip4_rehash_cb, &ctx);
1284       if (ctx.failure)
1285         {
1286           clib_bihash_free_16_8 (&new_hash);
1287           return -1;
1288         }
1289       else
1290         {
1291           clib_bihash_free_16_8 (&ip4_reass_main.hash);
1292           clib_memcpy_fast (&ip4_reass_main.hash, &new_hash,
1293                             sizeof (ip4_reass_main.hash));
1294           clib_bihash_copied (&ip4_reass_main.hash, &new_hash);
1295         }
1296     }
1297   return 0;
1298 }
1299
1300 vnet_api_error_t
1301 ip4_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1302                u32 * max_reassembly_length, u32 * expire_walk_interval_ms)
1303 {
1304   *timeout_ms = ip4_reass_main.timeout_ms;
1305   *max_reassemblies = ip4_reass_main.max_reass_n;
1306   *max_reassembly_length = ip4_reass_main.max_reass_len;
1307   *expire_walk_interval_ms = ip4_reass_main.expire_walk_interval_ms;
1308   return 0;
1309 }
1310
1311 static clib_error_t *
1312 ip4_reass_init_function (vlib_main_t * vm)
1313 {
1314   ip4_reass_main_t *rm = &ip4_reass_main;
1315   clib_error_t *error = 0;
1316   u32 nbuckets;
1317   vlib_node_t *node;
1318
1319   rm->vlib_main = vm;
1320   rm->vnet_main = vnet_get_main ();
1321
1322   vec_validate (rm->per_thread_data, vlib_num_workers ());
1323   ip4_reass_per_thread_t *rt;
1324   vec_foreach (rt, rm->per_thread_data)
1325   {
1326     clib_spinlock_init (&rt->lock);
1327     pool_alloc (rt->pool, rm->max_reass_n);
1328   }
1329
1330   node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk");
1331   ASSERT (node);
1332   rm->ip4_reass_expire_node_idx = node->index;
1333
1334   ip4_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS,
1335                         IP4_REASS_MAX_REASSEMBLIES_DEFAULT,
1336                         IP4_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT,
1337                         IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1338
1339   nbuckets = ip4_reass_get_nbuckets ();
1340   clib_bihash_init_16_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024);
1341
1342   node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
1343   ASSERT (node);
1344   rm->ip4_drop_idx = node->index;
1345
1346   rm->fq_index = vlib_frame_queue_main_init (ip4_reass_node.index, 0);
1347   rm->fq_feature_index =
1348     vlib_frame_queue_main_init (ip4_reass_node_feature.index, 0);
1349
1350
1351   return error;
1352 }
1353
1354 VLIB_INIT_FUNCTION (ip4_reass_init_function);
1355 #endif /* CLIB_MARCH_VARIANT */
1356
1357 static uword
1358 ip4_reass_walk_expired (vlib_main_t * vm,
1359                         vlib_node_runtime_t * node, vlib_frame_t * f)
1360 {
1361   ip4_reass_main_t *rm = &ip4_reass_main;
1362   uword event_type, *event_data = 0;
1363
1364   while (true)
1365     {
1366       vlib_process_wait_for_event_or_clock (vm,
1367                                             (f64)
1368                                             rm->expire_walk_interval_ms /
1369                                             (f64) MSEC_PER_SEC);
1370       event_type = vlib_process_get_events (vm, &event_data);
1371
1372       switch (event_type)
1373         {
1374         case ~0:                /* no events => timeout */
1375           /* nothing to do here */
1376           break;
1377         case IP4_EVENT_CONFIG_CHANGED:
1378           break;
1379         default:
1380           clib_warning ("BUG: event type 0x%wx", event_type);
1381           break;
1382         }
1383       f64 now = vlib_time_now (vm);
1384
1385       ip4_reass_t *reass;
1386       int *pool_indexes_to_free = NULL;
1387
1388       uword thread_index = 0;
1389       int index;
1390       const uword nthreads = vlib_num_workers () + 1;
1391       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1392         {
1393           ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1394           clib_spinlock_lock (&rt->lock);
1395
1396           vec_reset_length (pool_indexes_to_free);
1397           /* *INDENT-OFF* */
1398           pool_foreach_index (index, rt->pool, ({
1399                                 reass = pool_elt_at_index (rt->pool, index);
1400                                 if (now > reass->last_heard + rm->timeout)
1401                                   {
1402                                     vec_add1 (pool_indexes_to_free, index);
1403                                   }
1404                               }));
1405           /* *INDENT-ON* */
1406           int *i;
1407           /* *INDENT-OFF* */
1408           vec_foreach (i, pool_indexes_to_free)
1409           {
1410             ip4_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1411             ip4_reass_drop_all (vm, node, rm, reass);
1412             ip4_reass_free (rm, rt, reass);
1413           }
1414           /* *INDENT-ON* */
1415
1416           clib_spinlock_unlock (&rt->lock);
1417         }
1418
1419       vec_free (pool_indexes_to_free);
1420       if (event_data)
1421         {
1422           _vec_len (event_data) = 0;
1423         }
1424     }
1425
1426   return 0;
1427 }
1428
1429 /* *INDENT-OFF* */
1430 VLIB_REGISTER_NODE (ip4_reass_expire_node, static) = {
1431     .function = ip4_reass_walk_expired,
1432     .type = VLIB_NODE_TYPE_PROCESS,
1433     .name = "ip4-reassembly-expire-walk",
1434     .format_trace = format_ip4_reass_trace,
1435     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1436     .error_strings = ip4_reassembly_error_strings,
1437
1438 };
1439 /* *INDENT-ON* */
1440
1441 static u8 *
1442 format_ip4_reass_key (u8 * s, va_list * args)
1443 {
1444   ip4_reass_key_t *key = va_arg (*args, ip4_reass_key_t *);
1445   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1446               key->xx_id, format_ip4_address, &key->src, format_ip4_address,
1447               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1448   return s;
1449 }
1450
1451 static u8 *
1452 format_ip4_reass (u8 * s, va_list * args)
1453 {
1454   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1455   ip4_reass_t *reass = va_arg (*args, ip4_reass_t *);
1456
1457   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1458               "last_packet_octet: %u, trace_op_counter: %u\n",
1459               reass->id, format_ip4_reass_key, &reass->key, reass->first_bi,
1460               reass->data_len, reass->last_packet_octet,
1461               reass->trace_op_counter);
1462   u32 bi = reass->first_bi;
1463   u32 counter = 0;
1464   while (~0 != bi)
1465     {
1466       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1467       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1468       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1469                   "fragment[%u, %u]\n",
1470                   counter, vnb->ip.reass.range_first,
1471                   vnb->ip.reass.range_last, bi,
1472                   ip4_reass_buffer_get_data_offset (b),
1473                   ip4_reass_buffer_get_data_len (b),
1474                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1475       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1476         {
1477           bi = b->next_buffer;
1478         }
1479       else
1480         {
1481           bi = ~0;
1482         }
1483     }
1484   return s;
1485 }
1486
1487 static clib_error_t *
1488 show_ip4_reass (vlib_main_t * vm,
1489                 unformat_input_t * input,
1490                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1491 {
1492   ip4_reass_main_t *rm = &ip4_reass_main;
1493
1494   vlib_cli_output (vm, "---------------------");
1495   vlib_cli_output (vm, "IP4 reassembly status");
1496   vlib_cli_output (vm, "---------------------");
1497   bool details = false;
1498   if (unformat (input, "details"))
1499     {
1500       details = true;
1501     }
1502
1503   u32 sum_reass_n = 0;
1504   ip4_reass_t *reass;
1505   uword thread_index;
1506   const uword nthreads = vlib_num_workers () + 1;
1507   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1508     {
1509       ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1510       clib_spinlock_lock (&rt->lock);
1511       if (details)
1512         {
1513           /* *INDENT-OFF* */
1514           pool_foreach (reass, rt->pool, {
1515             vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass);
1516           });
1517           /* *INDENT-ON* */
1518         }
1519       sum_reass_n += rt->reass_n;
1520       clib_spinlock_unlock (&rt->lock);
1521     }
1522   vlib_cli_output (vm, "---------------------");
1523   vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
1524                    (long unsigned) sum_reass_n);
1525   vlib_cli_output (vm,
1526                    "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
1527                    (long unsigned) rm->max_reass_n);
1528   return 0;
1529 }
1530
1531 /* *INDENT-OFF* */
1532 VLIB_CLI_COMMAND (show_ip4_reassembly_cmd, static) = {
1533     .path = "show ip4-reassembly",
1534     .short_help = "show ip4-reassembly [details]",
1535     .function = show_ip4_reass,
1536 };
1537 /* *INDENT-ON* */
1538
1539 #ifndef CLIB_MARCH_VARIANT
1540 vnet_api_error_t
1541 ip4_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1542 {
1543   return vnet_feature_enable_disable ("ip4-unicast",
1544                                       "ip4-reassembly-feature", sw_if_index,
1545                                       enable_disable, 0, 0);
1546 }
1547 #endif /* CLIB_MARCH_VARIANT */
1548
1549
1550 #define foreach_ip4_reassembly_handoff_error                       \
1551 _(CONGESTION_DROP, "congestion drop")
1552
1553
1554 typedef enum
1555 {
1556 #define _(sym,str) IP4_REASSEMBLY_HANDOFF_ERROR_##sym,
1557   foreach_ip4_reassembly_handoff_error
1558 #undef _
1559     IP4_REASSEMBLY_HANDOFF_N_ERROR,
1560 } ip4_reassembly_handoff_error_t;
1561
1562 static char *ip4_reassembly_handoff_error_strings[] = {
1563 #define _(sym,string) string,
1564   foreach_ip4_reassembly_handoff_error
1565 #undef _
1566 };
1567
1568 typedef struct
1569 {
1570   u32 next_worker_index;
1571 } ip4_reassembly_handoff_trace_t;
1572
1573 static u8 *
1574 format_ip4_reassembly_handoff_trace (u8 * s, va_list * args)
1575 {
1576   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1577   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1578   ip4_reassembly_handoff_trace_t *t =
1579     va_arg (*args, ip4_reassembly_handoff_trace_t *);
1580
1581   s =
1582     format (s, "ip4-reassembly-handoff: next-worker %d",
1583             t->next_worker_index);
1584
1585   return s;
1586 }
1587
1588 always_inline uword
1589 ip4_reassembly_handoff_node_inline (vlib_main_t * vm,
1590                                     vlib_node_runtime_t * node,
1591                                     vlib_frame_t * frame, bool is_feature)
1592 {
1593   ip4_reass_main_t *rm = &ip4_reass_main;
1594
1595   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
1596   u32 n_enq, n_left_from, *from;
1597   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
1598   u32 fq_index;
1599
1600   from = vlib_frame_vector_args (frame);
1601   n_left_from = frame->n_vectors;
1602   vlib_get_buffers (vm, from, bufs, n_left_from);
1603
1604   b = bufs;
1605   ti = thread_indices;
1606
1607   fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index;
1608
1609   while (n_left_from > 0)
1610     {
1611       ti[0] =
1612         (is_feature) ? vnet_buffer (b[0])->ip.
1613         reass.owner_feature_thread_index : vnet_buffer (b[0])->ip.
1614         reass.owner_thread_index;
1615
1616       if (PREDICT_FALSE
1617           ((node->flags & VLIB_NODE_FLAG_TRACE)
1618            && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
1619         {
1620           ip4_reassembly_handoff_trace_t *t =
1621             vlib_add_trace (vm, node, b[0], sizeof (*t));
1622           t->next_worker_index = ti[0];
1623         }
1624
1625       n_left_from -= 1;
1626       ti += 1;
1627       b += 1;
1628     }
1629   n_enq =
1630     vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
1631                                    frame->n_vectors, 1);
1632
1633   if (n_enq < frame->n_vectors)
1634     vlib_node_increment_counter (vm, node->node_index,
1635                                  IP4_REASSEMBLY_HANDOFF_ERROR_CONGESTION_DROP,
1636                                  frame->n_vectors - n_enq);
1637   return frame->n_vectors;
1638 }
1639
1640 VLIB_NODE_FN (ip4_reassembly_handoff_node) (vlib_main_t * vm,
1641                                             vlib_node_runtime_t * node,
1642                                             vlib_frame_t * frame)
1643 {
1644   return ip4_reassembly_handoff_node_inline (vm, node, frame,
1645                                              false /* is_feature */ );
1646 }
1647
1648
1649 /* *INDENT-OFF* */
1650 VLIB_REGISTER_NODE (ip4_reassembly_handoff_node) = {
1651   .name = "ip4-reassembly-handoff",
1652   .vector_size = sizeof (u32),
1653   .n_errors = ARRAY_LEN(ip4_reassembly_handoff_error_strings),
1654   .error_strings = ip4_reassembly_handoff_error_strings,
1655   .format_trace = format_ip4_reassembly_handoff_trace,
1656
1657   .n_next_nodes = 1,
1658
1659   .next_nodes = {
1660     [0] = "error-drop",
1661   },
1662 };
1663 /* *INDENT-ON* */
1664
1665
1666 /* *INDENT-OFF* */
1667 VLIB_NODE_FN (ip4_reassembly_feature_handoff_node) (vlib_main_t * vm,
1668                                                     vlib_node_runtime_t *
1669                                                     node,
1670                                                     vlib_frame_t * frame)
1671 {
1672   return ip4_reassembly_handoff_node_inline (vm, node, frame,
1673                                              true /* is_feature */ );
1674 }
1675 /* *INDENT-ON* */
1676
1677
1678 /* *INDENT-OFF* */
1679 VLIB_REGISTER_NODE (ip4_reassembly_feature_handoff_node) = {
1680   .name = "ip4-reass-feature-hoff",
1681   .vector_size = sizeof (u32),
1682   .n_errors = ARRAY_LEN(ip4_reassembly_handoff_error_strings),
1683   .error_strings = ip4_reassembly_handoff_error_strings,
1684   .format_trace = format_ip4_reassembly_handoff_trace,
1685
1686   .n_next_nodes = 1,
1687
1688   .next_nodes = {
1689     [0] = "error-drop",
1690   },
1691 };
1692 /* *INDENT-ON* */
1693
1694 /*
1695  * fd.io coding-style-patch-verification: ON
1696  *
1697  * Local Variables:
1698  * eval: (c-set-style "gnu")
1699  * End:
1700  */