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   if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
 298     {
 299       // this buffer's trace is gone
 300       b->flags &= ~VLIB_BUFFER_IS_TRACED;
 301       return;
 302     }
 303   ip4_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 304   t->reass_id = reass->id;
 305   t->action = action;
 306   ip4_reass_trace_details (vm, bi, &t->trace_range);
 307   t->size_diff = size_diff;
 308   t->op_id = reass->trace_op_counter;
 309   ++reass->trace_op_counter;
 310   t->fragment_first = vnb->ip.reass.fragment_first;
 311   t->fragment_last = vnb->ip.reass.fragment_last;
 312   t->trace_range.first_bi = reass->first_bi;
 313   t->total_data_len = reass->data_len;
 314 #if 0
 315   static u8 *s = NULL;
 316   s = format (s, "%U", format_ip4_reass_trace, NULL, NULL, t);
 317   printf ("%.*s\n", vec_len (s), s);
 318   fflush (stdout);
 319   vec_reset_length (s);
 320 #endif
 321 }
 322
 323
 324 always_inline void
 325 ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 326                 ip4_reass_t * reass)
 327 {
 328   clib_bihash_kv_16_8_t kv;
 329   kv.key[0] = reass->key.as_u64[0];
 330   kv.key[1] = reass->key.as_u64[1];
 331   clib_bihash_add_del_16_8 (&rm->hash, &kv, 0);
 332   pool_put (rt->pool, reass);
 333   --rt->reass_n;
 334 }
 335
 336 always_inline void
 337 ip4_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
 338                     ip4_reass_main_t * rm, ip4_reass_t * reass)
 339 {
 340   u32 range_bi = reass->first_bi;
 341   vlib_buffer_t *range_b;
 342   vnet_buffer_opaque_t *range_vnb;
 343   u32 *to_free = NULL;
 344   while (~0 != range_bi)
 345     {
 346       range_b = vlib_get_buffer (vm, range_bi);
 347       range_vnb = vnet_buffer (range_b);
 348       u32 bi = range_bi;
 349       while (~0 != bi)
 350         {
 351           vec_add1 (to_free, bi);
 352           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 353           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 354             {
 355               bi = b->next_buffer;
 356               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 357             }
 358           else
 359             {
 360               bi = ~0;
 361             }
 362         }
 363       range_bi = range_vnb->ip.reass.next_range_bi;
 364     }
 365   /* send to next_error_index */
 366   if (~0 != reass->error_next_index)
 367     {
 368       u32 n_left_to_next, *to_next, next_index;
 369
 370       next_index = reass->error_next_index;
 371       u32 bi = ~0;
 372
 373       while (vec_len (to_free) > 0)
 374         {
 375           vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 376
 377           while (vec_len (to_free) > 0 && n_left_to_next > 0)
 378             {
 379               bi = vec_pop (to_free);
 380
 381               if (~0 != bi)
 382                 {
 383                   to_next[0] = bi;
 384                   to_next += 1;
 385                   n_left_to_next -= 1;
 386                   vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 387                                                    to_next, n_left_to_next,
 388                                                    bi, next_index);
 389                 }
 390             }
 391           vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 392         }
 393     }
 394   else
 395     {
 396       vlib_buffer_free (vm, to_free, vec_len (to_free));
 397     }
 398 }
 399
 400 static ip4_reass_t *
 401 ip4_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 402                           ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 403                           ip4_reass_kv_t * kv, u8 * do_handoff)
 404 {
 405   ip4_reass_t *reass = NULL;
 406   f64 now = vlib_time_now (rm->vlib_main);
 407
 408   if (!clib_bihash_search_16_8
 409       (&rm->hash, (clib_bihash_kv_16_8_t *) kv, (clib_bihash_kv_16_8_t *) kv))
 410     {
 411       if (vm->thread_index != kv->v.thread_index)
 412         {
 413           *do_handoff = 1;
 414           return NULL;
 415         }
 416       reass = pool_elt_at_index (rt->pool, kv->v.reass_index);
 417
 418       if (now > reass->last_heard + rm->timeout)
 419         {
 420           ip4_reass_drop_all (vm, node, rm, reass);
 421           ip4_reass_free (rm, rt, reass);
 422           reass = NULL;
 423         }
 424     }
 425
 426   if (reass)
 427     {
 428       reass->last_heard = now;
 429       return reass;
 430     }
 431
 432   if (rt->reass_n >= rm->max_reass_n)
 433     {
 434       reass = NULL;
 435       return reass;
 436     }
 437   else
 438     {
 439       pool_get (rt->pool, reass);
 440       clib_memset (reass, 0, sizeof (*reass));
 441       reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter;
 442       ++rt->id_counter;
 443       reass->first_bi = ~0;
 444       reass->last_packet_octet = ~0;
 445       reass->data_len = 0;
 446       reass->next_index = ~0;
 447       reass->error_next_index = ~0;
 448       ++rt->reass_n;
 449     }
 450
 451   reass->key.as_u64[0] = ((clib_bihash_kv_16_8_t *) kv)->key[0];
 452   reass->key.as_u64[1] = ((clib_bihash_kv_16_8_t *) kv)->key[1];
 453   kv->v.reass_index = (reass - rt->pool);
 454   kv->v.thread_index = vm->thread_index;
 455   reass->last_heard = now;
 456
 457   if (clib_bihash_add_del_16_8 (&rm->hash, (clib_bihash_kv_16_8_t *) kv, 1))
 458     {
 459       ip4_reass_free (rm, rt, reass);
 460       reass = NULL;
 461     }
 462
 463   return reass;
 464 }
 465
 466 always_inline ip4_reass_rc_t
 467 ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 468                     ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 469                     ip4_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 470                     bool is_custom_app)
 471 {
 472   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 473   vlib_buffer_t *last_b = NULL;
 474   u32 sub_chain_bi = reass->first_bi;
 475   u32 total_length = 0;
 476   u32 buf_cnt = 0;
 477   do
 478     {
 479       u32 tmp_bi = sub_chain_bi;
 480       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 481       ip4_header_t *ip = vlib_buffer_get_current (tmp);
 482       vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
 483       if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 484           !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 485         {
 486           return IP4_REASS_RC_INTERNAL_ERROR;
 487         }
 488
 489       u32 data_len = ip4_reass_buffer_get_data_len (tmp);
 490       u32 trim_front =
 491         ip4_header_bytes (ip) + ip4_reass_buffer_get_data_offset (tmp);
 492       u32 trim_end =
 493         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 494       if (tmp_bi == reass->first_bi)
 495         {
 496           /* first buffer - keep ip4 header */
 497           if (0 != ip4_reass_buffer_get_data_offset (tmp))
 498             {
 499               return IP4_REASS_RC_INTERNAL_ERROR;
 500             }
 501           trim_front = 0;
 502           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 503             ip4_header_bytes (ip);
 504           if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
 505             {
 506               return IP4_REASS_RC_INTERNAL_ERROR;
 507             }
 508         }
 509       u32 keep_data =
 510         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 511       while (1)
 512         {
 513           ++buf_cnt;
 514           if (trim_front)
 515             {
 516               if (trim_front > tmp->current_length)
 517                 {
 518                   /* drop whole buffer */
 519                   u32 to_be_freed_bi = tmp_bi;
 520                   trim_front -= tmp->current_length;
 521                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 522                     {
 523                       return IP4_REASS_RC_INTERNAL_ERROR;
 524                     }
 525                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 526                   tmp_bi = tmp->next_buffer;
 527                   tmp->next_buffer = 0;
 528                   tmp = vlib_get_buffer (vm, tmp_bi);
 529                   vlib_buffer_free_one (vm, to_be_freed_bi);
 530                   continue;
 531                 }
 532               else
 533                 {
 534                   vlib_buffer_advance (tmp, trim_front);
 535                   trim_front = 0;
 536                 }
 537             }
 538           if (keep_data)
 539             {
 540               if (last_b)
 541                 {
 542                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 543                   last_b->next_buffer = tmp_bi;
 544                 }
 545               last_b = tmp;
 546               if (keep_data <= tmp->current_length)
 547                 {
 548                   tmp->current_length = keep_data;
 549                   keep_data = 0;
 550                 }
 551               else
 552                 {
 553                   keep_data -= tmp->current_length;
 554                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 555                     {
 556                       return IP4_REASS_RC_INTERNAL_ERROR;
 557                     }
 558                 }
 559               total_length += tmp->current_length;
 560               if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 561                 {
 562                   tmp_bi = tmp->next_buffer;
 563                   tmp = vlib_get_buffer (vm, tmp->next_buffer);
 564                 }
 565               else
 566                 {
 567                   break;
 568                 }
 569             }
 570           else
 571             {
 572               u32 to_be_freed_bi = tmp_bi;
 573               if (reass->first_bi == tmp_bi)
 574                 {
 575                   return IP4_REASS_RC_INTERNAL_ERROR;
 576                 }
 577               if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 578                 {
 579                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 580                   tmp_bi = tmp->next_buffer;
 581                   tmp->next_buffer = 0;
 582                   tmp = vlib_get_buffer (vm, tmp_bi);
 583                   vlib_buffer_free_one (vm, to_be_freed_bi);
 584                 }
 585               else
 586                 {
 587                   tmp->next_buffer = 0;
 588                   vlib_buffer_free_one (vm, to_be_freed_bi);
 589                   break;
 590                 }
 591             }
 592         }
 593       sub_chain_bi =
 594         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 595         reass.next_range_bi;
 596     }
 597   while (~0 != sub_chain_bi);
 598
 599   if (!last_b)
 600     {
 601       return IP4_REASS_RC_INTERNAL_ERROR;
 602     }
 603   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 604
 605   if (total_length < first_b->current_length)
 606     {
 607       return IP4_REASS_RC_INTERNAL_ERROR;
 608     }
 609   total_length -= first_b->current_length;
 610   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 611   first_b->total_length_not_including_first_buffer = total_length;
 612   ip4_header_t *ip = vlib_buffer_get_current (first_b);
 613   ip->flags_and_fragment_offset = 0;
 614   ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
 615   ip->checksum = ip4_header_checksum (ip);
 616   if (!vlib_buffer_chain_linearize (vm, first_b))
 617     {
 618       return IP4_REASS_RC_NO_BUF;
 619     }
 620   // reset to reconstruct the mbuf linking
 621   first_b->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
 622   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 623     {
 624       ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 625 #if 0
 626       // following code does a hexdump of packet fragments to stdout ...
 627       do
 628         {
 629           u32 bi = reass->first_bi;
 630           u8 *s = NULL;
 631           while (~0 != bi)
 632             {
 633               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 634               s = format (s, "%u: %U\n", bi, format_hexdump,
 635                           vlib_buffer_get_current (b), b->current_length);
 636               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 637                 {
 638                   bi = b->next_buffer;
 639                 }
 640               else
 641                 {
 642                   break;
 643                 }
 644             }
 645           printf ("%.*s\n", vec_len (s), s);
 646           fflush (stdout);
 647           vec_free (s);
 648         }
 649       while (0);
 650 #endif
 651     }
 652   *bi0 = reass->first_bi;
 653   if (!is_custom_app)
 654     {
 655       *next0 = IP4_REASSEMBLY_NEXT_INPUT;
 656     }
 657   else
 658     {
 659       *next0 = reass->next_index;
 660     }
 661   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 662   *error0 = IP4_ERROR_NONE;
 663   ip4_reass_free (rm, rt, reass);
 664   reass = NULL;
 665   return IP4_REASS_RC_OK;
 666 }
 667
 668 always_inline ip4_reass_rc_t
 669 ip4_reass_insert_range_in_chain (vlib_main_t * vm,
 670                                  ip4_reass_main_t * rm,
 671                                  ip4_reass_per_thread_t * rt,
 672                                  ip4_reass_t * reass,
 673                                  u32 prev_range_bi, u32 new_next_bi)
 674 {
 675   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 676   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 677   if (~0 != prev_range_bi)
 678     {
 679       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 680       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 681       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 682       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 683     }
 684   else
 685     {
 686       if (~0 != reass->first_bi)
 687         {
 688           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 689         }
 690       reass->first_bi = new_next_bi;
 691     }
 692   vnet_buffer_opaque_t *vnb = vnet_buffer (new_next_b);
 693   if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 694       !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 695     {
 696       return IP4_REASS_RC_INTERNAL_ERROR;
 697     }
 698   reass->data_len += ip4_reass_buffer_get_data_len (new_next_b);
 699   return IP4_REASS_RC_OK;
 700 }
 701
 702 always_inline ip4_reass_rc_t
 703 ip4_reass_remove_range_from_chain (vlib_main_t * vm,
 704                                    vlib_node_runtime_t * node,
 705                                    ip4_reass_main_t * rm,
 706                                    ip4_reass_t * reass, u32 prev_range_bi,
 707                                    u32 discard_bi)
 708 {
 709   vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi);
 710   vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b);
 711   if (~0 != prev_range_bi)
 712     {
 713       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 714       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 715       if (!(prev_vnb->ip.reass.next_range_bi == discard_bi))
 716         {
 717           return IP4_REASS_RC_INTERNAL_ERROR;
 718         }
 719       prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi;
 720     }
 721   else
 722     {
 723       reass->first_bi = discard_vnb->ip.reass.next_range_bi;
 724     }
 725   vnet_buffer_opaque_t *vnb = vnet_buffer (discard_b);
 726   if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 727       !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 728     {
 729       return IP4_REASS_RC_INTERNAL_ERROR;
 730     }
 731   reass->data_len -= ip4_reass_buffer_get_data_len (discard_b);
 732   while (1)
 733     {
 734       u32 to_be_freed_bi = discard_bi;
 735       if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED))
 736         {
 737           ip4_reass_add_trace (vm, node, rm, reass, discard_bi, RANGE_DISCARD,
 738                                0);
 739         }
 740       if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT)
 741         {
 742           discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 743           discard_bi = discard_b->next_buffer;
 744           discard_b->next_buffer = 0;
 745           discard_b = vlib_get_buffer (vm, discard_bi);
 746           vlib_buffer_free_one (vm, to_be_freed_bi);
 747         }
 748       else
 749         {
 750           discard_b->next_buffer = 0;
 751           vlib_buffer_free_one (vm, to_be_freed_bi);
 752           break;
 753         }
 754     }
 755   return IP4_REASS_RC_OK;
 756 }
 757
 758 always_inline ip4_reass_rc_t
 759 ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 760                   ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 761                   ip4_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
 762                   bool is_custom_app)
 763 {
 764   ip4_reass_rc_t rc = IP4_REASS_RC_OK;
 765   int consumed = 0;
 766   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 767   ip4_header_t *fip = vlib_buffer_get_current (fb);
 768   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 769   if (is_custom_app)
 770     {
 771       // store (error_)next_index before it's overwritten
 772       reass->next_index = fvnb->ip.reass.next_index;
 773       reass->error_next_index = fvnb->ip.reass.error_next_index;
 774     }
 775   const u32 fragment_first = ip4_get_fragment_offset_bytes (fip);
 776   const u32 fragment_length =
 777     clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
 778   const u32 fragment_last = fragment_first + fragment_length - 1;
 779   fvnb->ip.reass.fragment_first = fragment_first;
 780   fvnb->ip.reass.fragment_last = fragment_last;
 781   int more_fragments = ip4_get_fragment_more (fip);
 782   u32 candidate_range_bi = reass->first_bi;
 783   u32 prev_range_bi = ~0;
 784   fvnb->ip.reass.range_first = fragment_first;
 785   fvnb->ip.reass.range_last = fragment_last;
 786   fvnb->ip.reass.next_range_bi = ~0;
 787   if (!more_fragments)
 788     {
 789       reass->last_packet_octet = fragment_last;
 790     }
 791   if (~0 == reass->first_bi)
 792     {
 793       // starting a new reassembly
 794       rc =
 795         ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 796                                          *bi0);
 797       if (IP4_REASS_RC_OK != rc)
 798         {
 799           return rc;
 800         }
 801       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 802         {
 803           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 804         }
 805       *bi0 = ~0;
 806       reass->min_fragment_length = clib_net_to_host_u16 (fip->length);
 807       reass->fragments_n = 1;
 808       return IP4_REASS_RC_OK;
 809     }
 810   reass->min_fragment_length = clib_min (clib_net_to_host_u16 (fip->length),
 811                                          fvnb->ip.reass.estimated_mtu);
 812   while (~0 != candidate_range_bi)
 813     {
 814       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 815       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 816       if (fragment_first > candidate_vnb->ip.reass.range_last)
 817         {
 818           // this fragments starts after candidate range
 819           prev_range_bi = candidate_range_bi;
 820           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 821           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 822               ~0 == candidate_range_bi)
 823             {
 824               // special case - this fragment falls beyond all known ranges
 825               rc =
 826                 ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 827                                                  prev_range_bi, *bi0);
 828               if (IP4_REASS_RC_OK != rc)
 829                 {
 830                   return rc;
 831                 }
 832               consumed = 1;
 833               break;
 834             }
 835           continue;
 836         }
 837       if (fragment_last < candidate_vnb->ip.reass.range_first)
 838         {
 839           // this fragment ends before candidate range without any overlap
 840           rc =
 841             ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 842                                              *bi0);
 843           if (IP4_REASS_RC_OK != rc)
 844             {
 845               return rc;
 846             }
 847           consumed = 1;
 848         }
 849       else
 850         {
 851           if (fragment_first >= candidate_vnb->ip.reass.range_first &&
 852               fragment_last <= candidate_vnb->ip.reass.range_last)
 853             {
 854               // this fragment is a (sub)part of existing range, ignore it
 855               if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 856                 {
 857                   ip4_reass_add_trace (vm, node, rm, reass, *bi0,
 858                                        RANGE_OVERLAP, 0);
 859                 }
 860               break;
 861             }
 862           int discard_candidate = 0;
 863           if (fragment_first < candidate_vnb->ip.reass.range_first)
 864             {
 865               u32 overlap =
 866                 fragment_last - candidate_vnb->ip.reass.range_first + 1;
 867               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 868                 {
 869                   candidate_vnb->ip.reass.range_first += overlap;
 870                   if (reass->data_len < overlap)
 871                     {
 872                       return IP4_REASS_RC_INTERNAL_ERROR;
 873                     }
 874                   reass->data_len -= overlap;
 875                   if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 876                     {
 877                       ip4_reass_add_trace (vm, node, rm, reass,
 878                                            candidate_range_bi, RANGE_SHRINK,
 879                                            overlap);
 880                     }
 881                   rc =
 882                     ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 883                                                      prev_range_bi, *bi0);
 884                   if (IP4_REASS_RC_OK != rc)
 885                     {
 886                       return rc;
 887                     }
 888                   consumed = 1;
 889                 }
 890               else
 891                 {
 892                   discard_candidate = 1;
 893                 }
 894             }
 895           else if (fragment_last > candidate_vnb->ip.reass.range_last)
 896             {
 897               u32 overlap =
 898                 candidate_vnb->ip.reass.range_last - fragment_first + 1;
 899               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 900                 {
 901                   fvnb->ip.reass.range_first += overlap;
 902                   if (~0 != candidate_vnb->ip.reass.next_range_bi)
 903                     {
 904                       prev_range_bi = candidate_range_bi;
 905                       candidate_range_bi =
 906                         candidate_vnb->ip.reass.next_range_bi;
 907                       continue;
 908                     }
 909                   else
 910                     {
 911                       // special case - last range discarded
 912                       rc =
 913                         ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 914                                                          candidate_range_bi,
 915                                                          *bi0);
 916                       if (IP4_REASS_RC_OK != rc)
 917                         {
 918                           return rc;
 919                         }
 920                       consumed = 1;
 921                     }
 922                 }
 923               else
 924                 {
 925                   discard_candidate = 1;
 926                 }
 927             }
 928           else
 929             {
 930               discard_candidate = 1;
 931             }
 932           if (discard_candidate)
 933             {
 934               u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi;
 935               // discard candidate range, probe next range
 936               rc =
 937                 ip4_reass_remove_range_from_chain (vm, node, rm, reass,
 938                                                    prev_range_bi,
 939                                                    candidate_range_bi);
 940               if (IP4_REASS_RC_OK != rc)
 941                 {
 942                   return rc;
 943                 }
 944               if (~0 != next_range_bi)
 945                 {
 946                   candidate_range_bi = next_range_bi;
 947                   continue;
 948                 }
 949               else
 950                 {
 951                   // special case - last range discarded
 952                   rc =
 953                     ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 954                                                      prev_range_bi, *bi0);
 955                   if (IP4_REASS_RC_OK != rc)
 956                     {
 957                       return rc;
 958                     }
 959                   consumed = 1;
 960                 }
 961             }
 962         }
 963       break;
 964     }
 965   ++reass->fragments_n;
 966   if (consumed)
 967     {
 968       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 969         {
 970           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 971         }
 972     }
 973   if (~0 != reass->last_packet_octet &&
 974       reass->data_len == reass->last_packet_octet + 1)
 975     {
 976       return ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 977                                  is_custom_app);
 978     }
 979   else
 980     {
 981       if (consumed)
 982         {
 983           *bi0 = ~0;
 984           if (reass->fragments_n > rm->max_reass_len)
 985             {
 986               rc = IP4_REASS_RC_TOO_MANY_FRAGMENTS;
 987             }
 988         }
 989       else
 990         {
 991           *next0 = IP4_REASSEMBLY_NEXT_DROP;
 992           *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT;
 993         }
 994     }
 995   return rc;
 996 }
 997
 998 always_inline uword
 999 ip4_reassembly_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1000                        vlib_frame_t * frame, bool is_feature,
1001                        bool is_custom_app)
1002 {
1003   u32 *from = vlib_frame_vector_args (frame);
1004   u32 n_left_from, n_left_to_next, *to_next, next_index;
1005   ip4_reass_main_t *rm = &ip4_reass_main;
1006   ip4_reass_per_thread_t *rt = &rm->per_thread_data[vm->thread_index];
1007   clib_spinlock_lock (&rt->lock);
1008
1009   n_left_from = frame->n_vectors;
1010   next_index = node->cached_next_index;
1011   while (n_left_from > 0)
1012     {
1013       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1014
1015       while (n_left_from > 0 && n_left_to_next > 0)
1016         {
1017           u32 bi0;
1018           vlib_buffer_t *b0;
1019           u32 next0;
1020           u32 error0 = IP4_ERROR_NONE;
1021
1022           bi0 = from[0];
1023           b0 = vlib_get_buffer (vm, bi0);
1024
1025           ip4_header_t *ip0 = vlib_buffer_get_current (b0);
1026           if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
1027             {
1028               // this is a whole packet - no fragmentation
1029               if (!is_custom_app)
1030                 {
1031                   next0 = IP4_REASSEMBLY_NEXT_INPUT;
1032                 }
1033               else
1034                 {
1035                   next0 = vnet_buffer (b0)->ip.reass.next_index;
1036                 }
1037             }
1038           else
1039             {
1040               const u32 fragment_first = ip4_get_fragment_offset_bytes (ip0);
1041               const u32 fragment_length =
1042                 clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0);
1043               const u32 fragment_last = fragment_first + fragment_length - 1;
1044               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
1045                 {
1046                   next0 = IP4_REASSEMBLY_NEXT_DROP;
1047                   error0 = IP4_ERROR_REASS_MALFORMED_PACKET;
1048                 }
1049               else
1050                 {
1051                   ip4_reass_kv_t kv;
1052                   u8 do_handoff = 0;
1053
1054                   kv.k.as_u64[0] =
1055                     (u64) vec_elt (ip4_main.fib_index_by_sw_if_index,
1056                                    vnet_buffer (b0)->sw_if_index[VLIB_RX]) |
1057                     (u64) ip0->src_address.as_u32 << 32;
1058                   kv.k.as_u64[1] =
1059                     (u64) ip0->dst_address.as_u32 |
1060                     (u64) ip0->fragment_id << 32 | (u64) ip0->protocol << 48;
1061
1062                   ip4_reass_t *reass =
1063                     ip4_reass_find_or_create (vm, node, rm, rt, &kv,
1064                                               &do_handoff);
1065
1066                   if (PREDICT_FALSE (do_handoff))
1067                     {
1068                       next0 = IP4_REASSEMBLY_NEXT_HANDOFF;
1069                       if (is_feature)
1070                         vnet_buffer (b0)->ip.
1071                           reass.owner_feature_thread_index =
1072                           kv.v.thread_index;
1073                       else
1074                         vnet_buffer (b0)->ip.reass.owner_thread_index =
1075                           kv.v.thread_index;
1076                     }
1077                   else if (reass)
1078                     {
1079                       switch (ip4_reass_update
1080                               (vm, node, rm, rt, reass, &bi0, &next0,
1081                                &error0, is_custom_app))
1082                         {
1083                         case IP4_REASS_RC_OK:
1084                           /* nothing to do here */
1085                           break;
1086                         case IP4_REASS_RC_TOO_MANY_FRAGMENTS:
1087                           vlib_node_increment_counter (vm, node->node_index,
1088                                                        IP4_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
1089                                                        1);
1090                           ip4_reass_drop_all (vm, node, rm, reass);
1091                           ip4_reass_free (rm, rt, reass);
1092                           goto next_packet;
1093                           break;
1094                         case IP4_REASS_RC_NO_BUF:
1095                           vlib_node_increment_counter (vm, node->node_index,
1096                                                        IP4_ERROR_REASS_NO_BUF,
1097                                                        1);
1098                           ip4_reass_drop_all (vm, node, rm, reass);
1099                           ip4_reass_free (rm, rt, reass);
1100                           goto next_packet;
1101                           break;
1102                         case IP4_REASS_RC_INTERNAL_ERROR:
1103                           /* drop everything and start with a clean slate */
1104                           vlib_node_increment_counter (vm, node->node_index,
1105                                                        IP4_ERROR_REASS_INTERNAL_ERROR,
1106                                                        1);
1107                           ip4_reass_drop_all (vm, node, rm, reass);
1108                           ip4_reass_free (rm, rt, reass);
1109                           goto next_packet;
1110                           break;
1111                         }
1112                     }
1113                   else
1114                     {
1115                       next0 = IP4_REASSEMBLY_NEXT_DROP;
1116                       error0 = IP4_ERROR_REASS_LIMIT_REACHED;
1117                     }
1118                 }
1119
1120               b0->error = node->errors[error0];
1121             }
1122
1123           if (bi0 != ~0)
1124             {
1125               to_next[0] = bi0;
1126               to_next += 1;
1127               n_left_to_next -= 1;
1128               if (is_feature && IP4_ERROR_NONE == error0)
1129                 {
1130                   b0 = vlib_get_buffer (vm, bi0);
1131                   vnet_feature_next (&next0, b0);
1132                 }
1133               vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1134                                                to_next, n_left_to_next,
1135                                                bi0, next0);
1136               IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next);
1137             }
1138
1139         next_packet:
1140           from += 1;
1141           n_left_from -= 1;
1142         }
1143
1144       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1145     }
1146
1147   clib_spinlock_unlock (&rt->lock);
1148   return frame->n_vectors;
1149 }
1150
1151 static char *ip4_reassembly_error_strings[] = {
1152 #define _(sym, string) string,
1153   foreach_ip4_error
1154 #undef _
1155 };
1156
1157 VLIB_NODE_FN (ip4_reass_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
1158                                vlib_frame_t * frame)
1159 {
1160   return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ ,
1161                                 false /* is_custom_app */ );
1162 }
1163
1164 /* *INDENT-OFF* */
1165 VLIB_REGISTER_NODE (ip4_reass_node) = {
1166     .name = "ip4-reassembly",
1167     .vector_size = sizeof (u32),
1168     .format_trace = format_ip4_reass_trace,
1169     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1170     .error_strings = ip4_reassembly_error_strings,
1171     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1172     .next_nodes =
1173         {
1174                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1175                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1176                 [IP4_REASSEMBLY_NEXT_HANDOFF] = "ip4-reassembly-handoff",
1177
1178         },
1179 };
1180 /* *INDENT-ON* */
1181
1182 VLIB_NODE_FN (ip4_reass_node_feature) (vlib_main_t * vm,
1183                                        vlib_node_runtime_t * node,
1184                                        vlib_frame_t * frame)
1185 {
1186   return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ ,
1187                                 false /* is_custom_app */ );
1188 }
1189
1190 /* *INDENT-OFF* */
1191 VLIB_REGISTER_NODE (ip4_reass_node_feature) = {
1192     .name = "ip4-reassembly-feature",
1193     .vector_size = sizeof (u32),
1194     .format_trace = format_ip4_reass_trace,
1195     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1196     .error_strings = ip4_reassembly_error_strings,
1197     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1198     .next_nodes =
1199         {
1200                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1201                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1202                 [IP4_REASSEMBLY_NEXT_HANDOFF] = "ip4-reass-feature-hoff",
1203         },
1204 };
1205 /* *INDENT-ON* */
1206
1207 /* *INDENT-OFF* */
1208 VNET_FEATURE_INIT (ip4_reassembly_feature, static) = {
1209     .arc_name = "ip4-unicast",
1210     .node_name = "ip4-reassembly-feature",
1211     .runs_before = VNET_FEATURES ("ip4-lookup"),
1212     .runs_after = 0,
1213 };
1214 /* *INDENT-ON* */
1215
1216 #ifndef CLIB_MARCH_VARIANT
1217 always_inline u32
1218 ip4_reass_get_nbuckets ()
1219 {
1220   ip4_reass_main_t *rm = &ip4_reass_main;
1221   u32 nbuckets;
1222   u8 i;
1223
1224   nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR);
1225
1226   for (i = 0; i < 31; i++)
1227     if ((1 << i) >= nbuckets)
1228       break;
1229   nbuckets = 1 << i;
1230
1231   return nbuckets;
1232 }
1233 #endif /* CLIB_MARCH_VARIANT */
1234
1235 typedef enum
1236 {
1237   IP4_EVENT_CONFIG_CHANGED = 1,
1238 } ip4_reass_event_t;
1239
1240 typedef struct
1241 {
1242   int failure;
1243   clib_bihash_16_8_t *new_hash;
1244 } ip4_rehash_cb_ctx;
1245
1246 #ifndef CLIB_MARCH_VARIANT
1247 static void
1248 ip4_rehash_cb (clib_bihash_kv_16_8_t * kv, void *_ctx)
1249 {
1250   ip4_rehash_cb_ctx *ctx = _ctx;
1251   if (clib_bihash_add_del_16_8 (ctx->new_hash, kv, 1))
1252     {
1253       ctx->failure = 1;
1254     }
1255 }
1256
1257 static void
1258 ip4_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1259                       u32 max_reassembly_length, u32 expire_walk_interval_ms)
1260 {
1261   ip4_reass_main.timeout_ms = timeout_ms;
1262   ip4_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1263   ip4_reass_main.max_reass_n = max_reassemblies;
1264   ip4_reass_main.max_reass_len = max_reassembly_length;
1265   ip4_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1266 }
1267
1268 vnet_api_error_t
1269 ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
1270                u32 max_reassembly_length, u32 expire_walk_interval_ms)
1271 {
1272   u32 old_nbuckets = ip4_reass_get_nbuckets ();
1273   ip4_reass_set_params (timeout_ms, max_reassemblies, max_reassembly_length,
1274                         expire_walk_interval_ms);
1275   vlib_process_signal_event (ip4_reass_main.vlib_main,
1276                              ip4_reass_main.ip4_reass_expire_node_idx,
1277                              IP4_EVENT_CONFIG_CHANGED, 0);
1278   u32 new_nbuckets = ip4_reass_get_nbuckets ();
1279   if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1280     {
1281       clib_bihash_16_8_t new_hash;
1282       clib_memset (&new_hash, 0, sizeof (new_hash));
1283       ip4_rehash_cb_ctx ctx;
1284       ctx.failure = 0;
1285       ctx.new_hash = &new_hash;
1286       clib_bihash_init_16_8 (&new_hash, "ip4-reass", new_nbuckets,
1287                              new_nbuckets * 1024);
1288       clib_bihash_foreach_key_value_pair_16_8 (&ip4_reass_main.hash,
1289                                                ip4_rehash_cb, &ctx);
1290       if (ctx.failure)
1291         {
1292           clib_bihash_free_16_8 (&new_hash);
1293           return -1;
1294         }
1295       else
1296         {
1297           clib_bihash_free_16_8 (&ip4_reass_main.hash);
1298           clib_memcpy_fast (&ip4_reass_main.hash, &new_hash,
1299                             sizeof (ip4_reass_main.hash));
1300         }
1301     }
1302   return 0;
1303 }
1304
1305 vnet_api_error_t
1306 ip4_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1307                u32 * max_reassembly_length, u32 * expire_walk_interval_ms)
1308 {
1309   *timeout_ms = ip4_reass_main.timeout_ms;
1310   *max_reassemblies = ip4_reass_main.max_reass_n;
1311   *max_reassembly_length = ip4_reass_main.max_reass_len;
1312   *expire_walk_interval_ms = ip4_reass_main.expire_walk_interval_ms;
1313   return 0;
1314 }
1315
1316 static clib_error_t *
1317 ip4_reass_init_function (vlib_main_t * vm)
1318 {
1319   ip4_reass_main_t *rm = &ip4_reass_main;
1320   clib_error_t *error = 0;
1321   u32 nbuckets;
1322   vlib_node_t *node;
1323
1324   rm->vlib_main = vm;
1325   rm->vnet_main = vnet_get_main ();
1326
1327   vec_validate (rm->per_thread_data, vlib_num_workers ());
1328   ip4_reass_per_thread_t *rt;
1329   vec_foreach (rt, rm->per_thread_data)
1330   {
1331     clib_spinlock_init (&rt->lock);
1332     pool_alloc (rt->pool, rm->max_reass_n);
1333   }
1334
1335   node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk");
1336   ASSERT (node);
1337   rm->ip4_reass_expire_node_idx = node->index;
1338
1339   ip4_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS,
1340                         IP4_REASS_MAX_REASSEMBLIES_DEFAULT,
1341                         IP4_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT,
1342                         IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1343
1344   nbuckets = ip4_reass_get_nbuckets ();
1345   clib_bihash_init_16_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024);
1346
1347   node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
1348   ASSERT (node);
1349   rm->ip4_drop_idx = node->index;
1350
1351   rm->fq_index = vlib_frame_queue_main_init (ip4_reass_node.index, 0);
1352   rm->fq_feature_index =
1353     vlib_frame_queue_main_init (ip4_reass_node_feature.index, 0);
1354
1355
1356   return error;
1357 }
1358
1359 VLIB_INIT_FUNCTION (ip4_reass_init_function);
1360 #endif /* CLIB_MARCH_VARIANT */
1361
1362 static uword
1363 ip4_reass_walk_expired (vlib_main_t * vm,
1364                         vlib_node_runtime_t * node, vlib_frame_t * f)
1365 {
1366   ip4_reass_main_t *rm = &ip4_reass_main;
1367   uword event_type, *event_data = 0;
1368
1369   while (true)
1370     {
1371       vlib_process_wait_for_event_or_clock (vm,
1372                                             (f64)
1373                                             rm->expire_walk_interval_ms /
1374                                             (f64) MSEC_PER_SEC);
1375       event_type = vlib_process_get_events (vm, &event_data);
1376
1377       switch (event_type)
1378         {
1379         case ~0:                /* no events => timeout */
1380           /* nothing to do here */
1381           break;
1382         case IP4_EVENT_CONFIG_CHANGED:
1383           break;
1384         default:
1385           clib_warning ("BUG: event type 0x%wx", event_type);
1386           break;
1387         }
1388       f64 now = vlib_time_now (vm);
1389
1390       ip4_reass_t *reass;
1391       int *pool_indexes_to_free = NULL;
1392
1393       uword thread_index = 0;
1394       int index;
1395       const uword nthreads = vlib_num_workers () + 1;
1396       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1397         {
1398           ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1399           clib_spinlock_lock (&rt->lock);
1400
1401           vec_reset_length (pool_indexes_to_free);
1402           /* *INDENT-OFF* */
1403           pool_foreach_index (index, rt->pool, ({
1404                                 reass = pool_elt_at_index (rt->pool, index);
1405                                 if (now > reass->last_heard + rm->timeout)
1406                                   {
1407                                     vec_add1 (pool_indexes_to_free, index);
1408                                   }
1409                               }));
1410           /* *INDENT-ON* */
1411           int *i;
1412           /* *INDENT-OFF* */
1413           vec_foreach (i, pool_indexes_to_free)
1414           {
1415             ip4_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1416             ip4_reass_drop_all (vm, node, rm, reass);
1417             ip4_reass_free (rm, rt, reass);
1418           }
1419           /* *INDENT-ON* */
1420
1421           clib_spinlock_unlock (&rt->lock);
1422         }
1423
1424       vec_free (pool_indexes_to_free);
1425       if (event_data)
1426         {
1427           _vec_len (event_data) = 0;
1428         }
1429     }
1430
1431   return 0;
1432 }
1433
1434 /* *INDENT-OFF* */
1435 VLIB_REGISTER_NODE (ip4_reass_expire_node, static) = {
1436     .function = ip4_reass_walk_expired,
1437     .type = VLIB_NODE_TYPE_PROCESS,
1438     .name = "ip4-reassembly-expire-walk",
1439     .format_trace = format_ip4_reass_trace,
1440     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1441     .error_strings = ip4_reassembly_error_strings,
1442
1443 };
1444 /* *INDENT-ON* */
1445
1446 static u8 *
1447 format_ip4_reass_key (u8 * s, va_list * args)
1448 {
1449   ip4_reass_key_t *key = va_arg (*args, ip4_reass_key_t *);
1450   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1451               key->xx_id, format_ip4_address, &key->src, format_ip4_address,
1452               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1453   return s;
1454 }
1455
1456 static u8 *
1457 format_ip4_reass (u8 * s, va_list * args)
1458 {
1459   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1460   ip4_reass_t *reass = va_arg (*args, ip4_reass_t *);
1461
1462   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1463               "last_packet_octet: %u, trace_op_counter: %u\n",
1464               reass->id, format_ip4_reass_key, &reass->key, reass->first_bi,
1465               reass->data_len, reass->last_packet_octet,
1466               reass->trace_op_counter);
1467   u32 bi = reass->first_bi;
1468   u32 counter = 0;
1469   while (~0 != bi)
1470     {
1471       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1472       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1473       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1474                   "fragment[%u, %u]\n",
1475                   counter, vnb->ip.reass.range_first,
1476                   vnb->ip.reass.range_last, bi,
1477                   ip4_reass_buffer_get_data_offset (b),
1478                   ip4_reass_buffer_get_data_len (b),
1479                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1480       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1481         {
1482           bi = b->next_buffer;
1483         }
1484       else
1485         {
1486           bi = ~0;
1487         }
1488     }
1489   return s;
1490 }
1491
1492 static clib_error_t *
1493 show_ip4_reass (vlib_main_t * vm,
1494                 unformat_input_t * input,
1495                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1496 {
1497   ip4_reass_main_t *rm = &ip4_reass_main;
1498
1499   vlib_cli_output (vm, "---------------------");
1500   vlib_cli_output (vm, "IP4 reassembly status");
1501   vlib_cli_output (vm, "---------------------");
1502   bool details = false;
1503   if (unformat (input, "details"))
1504     {
1505       details = true;
1506     }
1507
1508   u32 sum_reass_n = 0;
1509   ip4_reass_t *reass;
1510   uword thread_index;
1511   const uword nthreads = vlib_num_workers () + 1;
1512   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1513     {
1514       ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1515       clib_spinlock_lock (&rt->lock);
1516       if (details)
1517         {
1518           /* *INDENT-OFF* */
1519           pool_foreach (reass, rt->pool, {
1520             vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass);
1521           });
1522           /* *INDENT-ON* */
1523         }
1524       sum_reass_n += rt->reass_n;
1525       clib_spinlock_unlock (&rt->lock);
1526     }
1527   vlib_cli_output (vm, "---------------------");
1528   vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
1529                    (long unsigned) sum_reass_n);
1530   vlib_cli_output (vm,
1531                    "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
1532                    (long unsigned) rm->max_reass_n);
1533   return 0;
1534 }
1535
1536 /* *INDENT-OFF* */
1537 VLIB_CLI_COMMAND (show_ip4_reassembly_cmd, static) = {
1538     .path = "show ip4-reassembly",
1539     .short_help = "show ip4-reassembly [details]",
1540     .function = show_ip4_reass,
1541 };
1542 /* *INDENT-ON* */
1543
1544 #ifndef CLIB_MARCH_VARIANT
1545 vnet_api_error_t
1546 ip4_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1547 {
1548   return vnet_feature_enable_disable ("ip4-unicast",
1549                                       "ip4-reassembly-feature", sw_if_index,
1550                                       enable_disable, 0, 0);
1551 }
1552 #endif /* CLIB_MARCH_VARIANT */
1553
1554
1555 #define foreach_ip4_reassembly_handoff_error                       \
1556 _(CONGESTION_DROP, "congestion drop")
1557
1558
1559 typedef enum
1560 {
1561 #define _(sym,str) IP4_REASSEMBLY_HANDOFF_ERROR_##sym,
1562   foreach_ip4_reassembly_handoff_error
1563 #undef _
1564     IP4_REASSEMBLY_HANDOFF_N_ERROR,
1565 } ip4_reassembly_handoff_error_t;
1566
1567 static char *ip4_reassembly_handoff_error_strings[] = {
1568 #define _(sym,string) string,
1569   foreach_ip4_reassembly_handoff_error
1570 #undef _
1571 };
1572
1573 typedef struct
1574 {
1575   u32 next_worker_index;
1576 } ip4_reassembly_handoff_trace_t;
1577
1578 static u8 *
1579 format_ip4_reassembly_handoff_trace (u8 * s, va_list * args)
1580 {
1581   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1582   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1583   ip4_reassembly_handoff_trace_t *t =
1584     va_arg (*args, ip4_reassembly_handoff_trace_t *);
1585
1586   s =
1587     format (s, "ip4-reassembly-handoff: next-worker %d",
1588             t->next_worker_index);
1589
1590   return s;
1591 }
1592
1593 always_inline uword
1594 ip4_reassembly_handoff_node_inline (vlib_main_t * vm,
1595                                     vlib_node_runtime_t * node,
1596                                     vlib_frame_t * frame, bool is_feature)
1597 {
1598   ip4_reass_main_t *rm = &ip4_reass_main;
1599
1600   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
1601   u32 n_enq, n_left_from, *from;
1602   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
1603   u32 fq_index;
1604
1605   from = vlib_frame_vector_args (frame);
1606   n_left_from = frame->n_vectors;
1607   vlib_get_buffers (vm, from, bufs, n_left_from);
1608
1609   b = bufs;
1610   ti = thread_indices;
1611
1612   fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index;
1613
1614   while (n_left_from > 0)
1615     {
1616       ti[0] =
1617         (is_feature) ? vnet_buffer (b[0])->ip.
1618         reass.owner_feature_thread_index : vnet_buffer (b[0])->ip.
1619         reass.owner_thread_index;
1620
1621       if (PREDICT_FALSE
1622           ((node->flags & VLIB_NODE_FLAG_TRACE)
1623            && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
1624         {
1625           ip4_reassembly_handoff_trace_t *t =
1626             vlib_add_trace (vm, node, b[0], sizeof (*t));
1627           t->next_worker_index = ti[0];
1628         }
1629
1630       n_left_from -= 1;
1631       ti += 1;
1632       b += 1;
1633     }
1634   n_enq =
1635     vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
1636                                    frame->n_vectors, 1);
1637
1638   if (n_enq < frame->n_vectors)
1639     vlib_node_increment_counter (vm, node->node_index,
1640                                  IP4_REASSEMBLY_HANDOFF_ERROR_CONGESTION_DROP,
1641                                  frame->n_vectors - n_enq);
1642   return frame->n_vectors;
1643 }
1644
1645 VLIB_NODE_FN (ip4_reassembly_handoff_node) (vlib_main_t * vm,
1646                                             vlib_node_runtime_t * node,
1647                                             vlib_frame_t * frame)
1648 {
1649   return ip4_reassembly_handoff_node_inline (vm, node, frame,
1650                                              false /* is_feature */ );
1651 }
1652
1653
1654 /* *INDENT-OFF* */
1655 VLIB_REGISTER_NODE (ip4_reassembly_handoff_node) = {
1656   .name = "ip4-reassembly-handoff",
1657   .vector_size = sizeof (u32),
1658   .n_errors = ARRAY_LEN(ip4_reassembly_handoff_error_strings),
1659   .error_strings = ip4_reassembly_handoff_error_strings,
1660   .format_trace = format_ip4_reassembly_handoff_trace,
1661
1662   .n_next_nodes = 1,
1663
1664   .next_nodes = {
1665     [0] = "error-drop",
1666   },
1667 };
1668 /* *INDENT-ON* */
1669
1670
1671 /* *INDENT-OFF* */
1672 VLIB_NODE_FN (ip4_reassembly_feature_handoff_node) (vlib_main_t * vm,
1673                                                     vlib_node_runtime_t *
1674                                                     node,
1675                                                     vlib_frame_t * frame)
1676 {
1677   return ip4_reassembly_handoff_node_inline (vm, node, frame,
1678                                              true /* is_feature */ );
1679 }
1680 /* *INDENT-ON* */
1681
1682
1683 /* *INDENT-OFF* */
1684 VLIB_REGISTER_NODE (ip4_reassembly_feature_handoff_node) = {
1685   .name = "ip4-reass-feature-hoff",
1686   .vector_size = sizeof (u32),
1687   .n_errors = ARRAY_LEN(ip4_reassembly_handoff_error_strings),
1688   .error_strings = ip4_reassembly_handoff_error_strings,
1689   .format_trace = format_ip4_reassembly_handoff_trace,
1690
1691   .n_next_nodes = 1,
1692
1693   .next_nodes = {
1694     [0] = "error-drop",
1695   },
1696 };
1697 /* *INDENT-ON* */
1698
1699 /*
1700  * fd.io coding-style-patch-verification: ON
1701  *
1702  * Local Variables:
1703  * eval: (c-set-style "gnu")
1704  * End:
1705  */