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_24_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_HT_LOAD_FACTOR (0.75)
  34
  35 #define IP4_REASS_DEBUG_BUFFERS 0
  36 #if IP4_REASS_DEBUG_BUFFERS
  37 #define IP4_REASS_DEBUG_BUFFER(bi, what)             \
  38   do                                                 \
  39     {                                                \
  40       u32 _bi = bi;                                  \
  41       printf (#what "buffer %u", _bi);               \
  42       vlib_buffer_t *_b = vlib_get_buffer (vm, _bi); \
  43       while (_b->flags & VLIB_BUFFER_NEXT_PRESENT)   \
  44         {                                            \
  45           _bi = _b->next_buffer;                     \
  46           printf ("[%u]", _bi);                      \
  47           _b = vlib_get_buffer (vm, _bi);            \
  48         }                                            \
  49       printf ("\n");                                 \
  50       fflush (stdout);                               \
  51     }                                                \
  52   while (0)
  53 #else
  54 #define IP4_REASS_DEBUG_BUFFER(...)
  55 #endif
  56
  57 static vlib_node_registration_t ip4_reass_node;
  58
  59 typedef struct
  60 {
  61   union
  62   {
  63     struct
  64     {
  65       // align by making this 4 octets even though its a 2 octets field
  66       u32 xx_id;
  67       ip4_address_t src;
  68       ip4_address_t dst;
  69       // align by making this 4 octets even though its a 2 octets field
  70       u32 frag_id;
  71       // align by making this 4 octets even though its a 1 octet field
  72       u32 proto;
  73       u32 unused;
  74     };
  75     u64 as_u64[3];
  76   };
  77 } ip4_reass_key_t;
  78
  79 always_inline u32
  80 ip4_reass_buffer_get_data_offset_no_check (vlib_buffer_t * b)
  81 {
  82   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  83   return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
  84 }
  85
  86 always_inline u32
  87 ip4_reass_buffer_get_data_offset (vlib_buffer_t * b)
  88 {
  89   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  90   ASSERT (vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first);
  91   return ip4_reass_buffer_get_data_offset_no_check (b);
  92 }
  93
  94 always_inline u16
  95 ip4_reass_buffer_get_data_len_no_check (vlib_buffer_t * b)
  96 {
  97   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  98   return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
  99     (vnb->ip.reass.fragment_first + ip4_reass_buffer_get_data_offset (b)) + 1;
 100 }
 101
 102 always_inline u16
 103 ip4_reass_buffer_get_data_len (vlib_buffer_t * b)
 104 {
 105   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 106   ASSERT (vnb->ip.reass.range_last > vnb->ip.reass.fragment_first);
 107   return ip4_reass_buffer_get_data_len_no_check (b);
 108 }
 109
 110 typedef struct
 111 {
 112   // hash table key
 113   ip4_reass_key_t key;
 114   // time when last packet was received
 115   f64 last_heard;
 116   // internal id of this reassembly
 117   u64 id;
 118   // buffer index of first buffer in this reassembly context
 119   u32 first_bi;
 120   // last octet of packet, ~0 until fragment without more_fragments arrives
 121   u32 last_packet_octet;
 122   // length of data collected so far
 123   u32 data_len;
 124   // trace operation counter
 125   u32 trace_op_counter;
 126   // next index - used by non-feature node
 127   u8 next_index;
 128   // minimum fragment length for this reassembly - used to estimate MTU
 129   u16 min_fragment_length;
 130 } ip4_reass_t;
 131
 132 typedef struct
 133 {
 134   ip4_reass_t *pool;
 135   u32 reass_n;
 136   u32 buffers_n;
 137   u32 id_counter;
 138   clib_spinlock_t lock;
 139 } ip4_reass_per_thread_t;
 140
 141 typedef struct
 142 {
 143   // IPv4 config
 144   u32 timeout_ms;
 145   f64 timeout;
 146   u32 expire_walk_interval_ms;
 147   u32 max_reass_n;
 148
 149   // IPv4 runtime
 150   clib_bihash_24_8_t hash;
 151   // per-thread data
 152   ip4_reass_per_thread_t *per_thread_data;
 153
 154   // convenience
 155   vlib_main_t *vlib_main;
 156   vnet_main_t *vnet_main;
 157
 158   // node index of ip4-drop node
 159   u32 ip4_drop_idx;
 160   u32 ip4_reass_expire_node_idx;
 161 } ip4_reass_main_t;
 162
 163 ip4_reass_main_t ip4_reass_main;
 164
 165 typedef enum
 166 {
 167   IP4_REASSEMBLY_NEXT_INPUT,
 168   IP4_REASSEMBLY_NEXT_DROP,
 169   IP4_REASSEMBLY_N_NEXT,
 170 } ip4_reass_next_t;
 171
 172 typedef enum
 173 {
 174   RANGE_NEW,
 175   RANGE_SHRINK,
 176   RANGE_DISCARD,
 177   RANGE_OVERLAP,
 178   FINALIZE,
 179 } ip4_reass_trace_operation_e;
 180
 181 typedef struct
 182 {
 183   u16 range_first;
 184   u16 range_last;
 185   u32 range_bi;
 186   i32 data_offset;
 187   u32 data_len;
 188   u32 first_bi;
 189 } ip4_reass_range_trace_t;
 190
 191 typedef struct
 192 {
 193   ip4_reass_trace_operation_e action;
 194   u32 reass_id;
 195   ip4_reass_range_trace_t trace_range;
 196   u32 size_diff;
 197   u32 op_id;
 198   u32 fragment_first;
 199   u32 fragment_last;
 200   u32 total_data_len;
 201 } ip4_reass_trace_t;
 202
 203 static void
 204 ip4_reass_trace_details (vlib_main_t * vm, u32 bi,
 205                          ip4_reass_range_trace_t * trace)
 206 {
 207   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 208   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 209   trace->range_first = vnb->ip.reass.range_first;
 210   trace->range_last = vnb->ip.reass.range_last;
 211   trace->data_offset = ip4_reass_buffer_get_data_offset_no_check (b);
 212   trace->data_len = ip4_reass_buffer_get_data_len_no_check (b);
 213   trace->range_bi = bi;
 214 }
 215
 216 static u8 *
 217 format_ip4_reass_range_trace (u8 * s, va_list * args)
 218 {
 219   ip4_reass_range_trace_t *trace = va_arg (*args, ip4_reass_range_trace_t *);
 220   s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
 221               trace->range_last, trace->data_offset, trace->data_len,
 222               trace->range_bi);
 223   return s;
 224 }
 225
 226 u8 *
 227 format_ip4_reass_trace (u8 * s, va_list * args)
 228 {
 229   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 230   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 231   ip4_reass_trace_t *t = va_arg (*args, ip4_reass_trace_t *);
 232   s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
 233   u32 indent = format_get_indent (s);
 234   s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
 235               t->trace_range.first_bi, t->total_data_len, t->fragment_first,
 236               t->fragment_last);
 237   switch (t->action)
 238     {
 239     case RANGE_SHRINK:
 240       s = format (s, "\n%Ushrink %U by %u", format_white_space, indent,
 241                   format_ip4_reass_range_trace, &t->trace_range,
 242                   t->size_diff);
 243       break;
 244     case RANGE_DISCARD:
 245       s = format (s, "\n%Udiscard %U", format_white_space, indent,
 246                   format_ip4_reass_range_trace, &t->trace_range);
 247       break;
 248     case RANGE_NEW:
 249       s = format (s, "\n%Unew %U", format_white_space, indent,
 250                   format_ip4_reass_range_trace, &t->trace_range);
 251       break;
 252     case RANGE_OVERLAP:
 253       s = format (s, "\n%Uoverlapping/ignored %U", format_white_space, indent,
 254                   format_ip4_reass_range_trace, &t->trace_range);
 255       break;
 256     case FINALIZE:
 257       s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
 258       break;
 259     }
 260   return s;
 261 }
 262
 263 static void
 264 ip4_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 265                      ip4_reass_main_t * rm, ip4_reass_t * reass, u32 bi,
 266                      ip4_reass_trace_operation_e action, u32 size_diff)
 267 {
 268   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 269   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 270   if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
 271     {
 272       // this buffer's trace is gone
 273       b->flags &= ~VLIB_BUFFER_IS_TRACED;
 274       return;
 275     }
 276   ip4_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 277   t->reass_id = reass->id;
 278   t->action = action;
 279   ip4_reass_trace_details (vm, bi, &t->trace_range);
 280   t->size_diff = size_diff;
 281   t->op_id = reass->trace_op_counter;
 282   ++reass->trace_op_counter;
 283   t->fragment_first = vnb->ip.reass.fragment_first;
 284   t->fragment_last = vnb->ip.reass.fragment_last;
 285   t->trace_range.first_bi = reass->first_bi;
 286   t->total_data_len = reass->data_len;
 287 #if 0
 288   static u8 *s = NULL;
 289   s = format (s, "%U", format_ip4_reass_trace, NULL, NULL, t);
 290   printf ("%.*s\n", vec_len (s), s);
 291   fflush (stdout);
 292   vec_reset_length (s);
 293 #endif
 294 }
 295
 296 always_inline void
 297 ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 298                 ip4_reass_t * reass)
 299 {
 300   clib_bihash_kv_24_8_t kv;
 301   kv.key[0] = reass->key.as_u64[0];
 302   kv.key[1] = reass->key.as_u64[1];
 303   kv.key[2] = reass->key.as_u64[2];
 304   clib_bihash_add_del_24_8 (&rm->hash, &kv, 0);
 305   pool_put (rt->pool, reass);
 306   --rt->reass_n;
 307 }
 308
 309 always_inline void
 310 ip4_reass_on_timeout (vlib_main_t * vm, ip4_reass_main_t * rm,
 311                       ip4_reass_t * reass, u32 ** vec_drop_timeout)
 312 {
 313   u32 range_bi = reass->first_bi;
 314   vlib_buffer_t *range_b;
 315   vnet_buffer_opaque_t *range_vnb;
 316   while (~0 != range_bi)
 317     {
 318       range_b = vlib_get_buffer (vm, range_bi);
 319       range_vnb = vnet_buffer (range_b);
 320       u32 bi = range_bi;
 321       while (~0 != bi)
 322         {
 323           vec_add1 (*vec_drop_timeout, bi);
 324           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 325           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 326             {
 327               bi = b->next_buffer;
 328               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 329             }
 330           else
 331             {
 332               bi = ~0;
 333             }
 334         }
 335       range_bi = range_vnb->ip.reass.next_range_bi;
 336     }
 337 }
 338
 339 ip4_reass_t *
 340 ip4_reass_find_or_create (vlib_main_t * vm, ip4_reass_main_t * rm,
 341                           ip4_reass_per_thread_t * rt,
 342                           ip4_reass_key_t * k, u32 ** vec_drop_timeout)
 343 {
 344   ip4_reass_t *reass = NULL;
 345   f64 now = vlib_time_now (rm->vlib_main);
 346   clib_bihash_kv_24_8_t kv, value;
 347   kv.key[0] = k->as_u64[0];
 348   kv.key[1] = k->as_u64[1];
 349   kv.key[2] = k->as_u64[2];
 350
 351   if (!clib_bihash_search_24_8 (&rm->hash, &kv, &value))
 352     {
 353       reass = pool_elt_at_index (rt->pool, value.value);
 354       if (now > reass->last_heard + rm->timeout)
 355         {
 356           ip4_reass_on_timeout (vm, rm, reass, vec_drop_timeout);
 357           ip4_reass_free (rm, rt, reass);
 358           reass = NULL;
 359         }
 360     }
 361
 362   if (reass)
 363     {
 364       reass->last_heard = now;
 365       return reass;
 366     }
 367
 368   if (rt->reass_n >= rm->max_reass_n)
 369     {
 370       reass = NULL;
 371       return reass;
 372     }
 373   else
 374     {
 375       pool_get (rt->pool, reass);
 376       memset (reass, 0, sizeof (*reass));
 377       reass->id =
 378         ((u64) os_get_thread_index () * 1000000000) + rt->id_counter;
 379       ++rt->id_counter;
 380       reass->first_bi = ~0;
 381       reass->last_packet_octet = ~0;
 382       reass->data_len = 0;
 383       ++rt->reass_n;
 384     }
 385
 386   reass->key.as_u64[0] = kv.key[0] = k->as_u64[0];
 387   reass->key.as_u64[1] = kv.key[1] = k->as_u64[1];
 388   reass->key.as_u64[2] = kv.key[2] = k->as_u64[2];
 389   kv.value = reass - rt->pool;
 390   reass->last_heard = now;
 391
 392   if (clib_bihash_add_del_24_8 (&rm->hash, &kv, 1))
 393     {
 394       ip4_reass_free (rm, rt, reass);
 395       reass = NULL;
 396     }
 397
 398   return reass;
 399 }
 400
 401 always_inline void
 402 ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 403                     ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 404                     ip4_reass_t * reass, u32 * bi0, u32 * next0,
 405                     vlib_error_t * error0, u32 ** vec_drop_compress,
 406                     u32 ** vec_drop_overlap, bool is_feature)
 407 {
 408   ASSERT (~0 != reass->first_bi);
 409   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 410   vlib_buffer_t *last_b = NULL;
 411   u32 sub_chain_bi = reass->first_bi;
 412   u32 total_length = 0;
 413   u32 buf_cnt = 0;
 414   u32 dropped_cnt = 0;
 415   do
 416     {
 417       u32 tmp_bi = sub_chain_bi;
 418       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 419       ip4_header_t *ip = vlib_buffer_get_current (tmp);
 420       u32 data_len = ip4_reass_buffer_get_data_len (tmp);
 421       u32 trim_front =
 422         ip4_header_bytes (ip) + ip4_reass_buffer_get_data_offset (tmp);
 423       u32 trim_end =
 424         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 425       if (tmp_bi == reass->first_bi)
 426         {
 427           /* first buffer - keep ip4 header */
 428           ASSERT (0 == ip4_reass_buffer_get_data_offset (tmp));
 429           trim_front = 0;
 430           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 431             ip4_header_bytes (ip);
 432           ASSERT (vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0);
 433         }
 434       u32 keep_data =
 435         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 436       while (1)
 437         {
 438           ++buf_cnt;
 439           if (trim_front)
 440             {
 441               if (trim_front > tmp->current_length)
 442                 {
 443                   /* drop whole buffer */
 444                   vec_add1 (*vec_drop_compress, tmp_bi);
 445                   ++dropped_cnt;
 446                   trim_front -= tmp->current_length;
 447                   ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
 448                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 449                   tmp_bi = tmp->next_buffer;
 450                   tmp = vlib_get_buffer (vm, tmp_bi);
 451                   continue;
 452                 }
 453               else
 454                 {
 455                   vlib_buffer_advance (tmp, trim_front);
 456                   trim_front = 0;
 457                 }
 458             }
 459           if (keep_data)
 460             {
 461               if (last_b)
 462                 {
 463                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 464                   last_b->next_buffer = tmp_bi;
 465                 }
 466               last_b = tmp;
 467               if (keep_data <= tmp->current_length)
 468                 {
 469                   tmp->current_length = keep_data;
 470                   keep_data = 0;
 471                 }
 472               else
 473                 {
 474                   keep_data -= tmp->current_length;
 475                   ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
 476                 }
 477               total_length += tmp->current_length;
 478             }
 479           else
 480             {
 481               vec_add1 (*vec_drop_overlap, tmp_bi);
 482               ASSERT (reass->first_bi != tmp_bi);
 483               ++dropped_cnt;
 484             }
 485           if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 486             {
 487               tmp_bi = tmp->next_buffer;
 488               tmp = vlib_get_buffer (vm, tmp->next_buffer);
 489             }
 490           else
 491             {
 492               break;
 493             }
 494         }
 495       sub_chain_bi =
 496         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 497         reass.next_range_bi;
 498     }
 499   while (~0 != sub_chain_bi);
 500   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 501   ASSERT (rt->buffers_n >= (buf_cnt - dropped_cnt));
 502   rt->buffers_n -= buf_cnt - dropped_cnt;
 503   ASSERT (total_length >= first_b->current_length);
 504   total_length -= first_b->current_length;
 505   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 506   first_b->total_length_not_including_first_buffer = total_length;
 507   ip4_header_t *ip = vlib_buffer_get_current (first_b);
 508   ip->flags_and_fragment_offset = 0;
 509   ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
 510   ip->checksum = ip4_header_checksum (ip);
 511   vlib_buffer_chain_compress (vm, first_b, vec_drop_compress);
 512   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 513     {
 514       ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 515 #if 0
 516       // following code does a hexdump of packet fragments to stdout ...
 517       do
 518         {
 519           u32 bi = reass->first_bi;
 520           u8 *s = NULL;
 521           while (~0 != bi)
 522             {
 523               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 524               s = format (s, "%u: %U\n", bi, format_hexdump,
 525                           vlib_buffer_get_current (b), b->current_length);
 526               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 527                 {
 528                   bi = b->next_buffer;
 529                 }
 530               else
 531                 {
 532                   break;
 533                 }
 534             }
 535           printf ("%.*s\n", vec_len (s), s);
 536           fflush (stdout);
 537           vec_free (s);
 538         }
 539       while (0);
 540 #endif
 541     }
 542   *bi0 = reass->first_bi;
 543   if (is_feature)
 544     {
 545       *next0 = IP4_REASSEMBLY_NEXT_INPUT;
 546     }
 547   else
 548     {
 549       *next0 = reass->next_index;
 550     }
 551   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 552   *error0 = IP4_ERROR_NONE;
 553   ip4_reass_free (rm, rt, reass);
 554   reass = NULL;
 555 }
 556
 557 always_inline u32
 558 ip4_reass_get_buffer_chain_length (vlib_main_t * vm, vlib_buffer_t * b)
 559 {
 560   u32 len = 0;
 561   while (b)
 562     {
 563       ++len;
 564       if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
 565         {
 566           b = vlib_get_buffer (vm, b->next_buffer);
 567         }
 568       else
 569         {
 570           break;
 571         }
 572     }
 573   return len;
 574 }
 575
 576 always_inline void
 577 ip4_reass_insert_range_in_chain (vlib_main_t * vm,
 578                                  ip4_reass_main_t * rm,
 579                                  ip4_reass_per_thread_t * rt,
 580                                  ip4_reass_t * reass,
 581                                  u32 prev_range_bi, u32 new_next_bi)
 582 {
 583
 584   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 585   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 586   if (~0 != prev_range_bi)
 587     {
 588       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 589       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 590       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 591       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 592     }
 593   else
 594     {
 595       if (~0 != reass->first_bi)
 596         {
 597           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 598         }
 599       reass->first_bi = new_next_bi;
 600     }
 601   reass->data_len += ip4_reass_buffer_get_data_len (new_next_b);
 602   rt->buffers_n += ip4_reass_get_buffer_chain_length (vm, new_next_b);
 603 }
 604
 605 always_inline void
 606 ip4_reass_remove_range_from_chain (vlib_main_t * vm,
 607                                    vlib_node_runtime_t * node,
 608                                    ip4_reass_main_t * rm,
 609                                    u32 ** vec_drop_overlap,
 610                                    ip4_reass_t * reass, u32 prev_range_bi,
 611                                    u32 discard_bi)
 612 {
 613   vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi);
 614   vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b);
 615   if (~0 != prev_range_bi)
 616     {
 617       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 618       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 619       ASSERT (prev_vnb->ip.reass.next_range_bi == discard_bi);
 620       prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi;
 621     }
 622   else
 623     {
 624       reass->first_bi = discard_vnb->ip.reass.next_range_bi;
 625     }
 626   reass->data_len -= ip4_reass_buffer_get_data_len (discard_b);
 627   while (1)
 628     {
 629       vec_add1 (*vec_drop_overlap, discard_bi);
 630       if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED))
 631         {
 632           ip4_reass_add_trace (vm, node, rm, reass, discard_bi, RANGE_DISCARD,
 633                                0);
 634         }
 635       if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT)
 636         {
 637           discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 638           discard_bi = discard_b->next_buffer;
 639           discard_b = vlib_get_buffer (vm, discard_bi);
 640         }
 641       else
 642         {
 643           break;
 644         }
 645     }
 646 }
 647
 648 always_inline void
 649 ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 650                   ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 651                   ip4_reass_t * reass, u32 * bi0, u32 * next0,
 652                   vlib_error_t * error0, u32 ** vec_drop_overlap,
 653                   u32 ** vec_drop_compress, bool is_feature)
 654 {
 655   int consumed = 0;
 656   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 657   ip4_header_t *fip = vlib_buffer_get_current (fb);
 658   ASSERT (fb->current_length >= sizeof (*fip));
 659   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 660   u32 fragment_first = fvnb->ip.reass.fragment_first =
 661     ip4_get_fragment_offset_bytes (fip);
 662   u32 fragment_length =
 663     clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
 664   u32 fragment_last = fvnb->ip.reass.fragment_last =
 665     fragment_first + fragment_length - 1;
 666   int more_fragments = ip4_get_fragment_more (fip);
 667   u32 candidate_range_bi = reass->first_bi;
 668   u32 prev_range_bi = ~0;
 669   reass->next_index = fvnb->ip.reass.next_index;        // store next_index before it's overwritten
 670   fvnb->ip.reass.range_first = fragment_first;
 671   fvnb->ip.reass.range_last = fragment_last;
 672   fvnb->ip.reass.next_range_bi = ~0;
 673   if (!more_fragments)
 674     {
 675       reass->last_packet_octet = fragment_last;
 676     }
 677   if (~0 == reass->first_bi)
 678     {
 679       // starting a new reassembly
 680       ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 681                                        *bi0);
 682       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 683         {
 684           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 685         }
 686       *bi0 = ~0;
 687       reass->min_fragment_length = clib_net_to_host_u16 (fip->length);
 688       return;
 689     }
 690   reass->min_fragment_length = clib_min (clib_net_to_host_u16 (fip->length),
 691                                          fvnb->ip.reass.estimated_mtu);
 692   while (~0 != candidate_range_bi)
 693     {
 694       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 695       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 696       if (fragment_first > candidate_vnb->ip.reass.range_last)
 697         {
 698           // this fragments starts after candidate range
 699           prev_range_bi = candidate_range_bi;
 700           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 701           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 702               ~0 == candidate_range_bi)
 703             {
 704               // special case - this fragment falls beyond all known ranges
 705               ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 706                                                prev_range_bi, *bi0);
 707               consumed = 1;
 708               break;
 709             }
 710           continue;
 711         }
 712       if (fragment_last < candidate_vnb->ip.reass.range_first)
 713         {
 714           // this fragment ends before candidate range without any overlap
 715           ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 716                                            *bi0);
 717           consumed = 1;
 718         }
 719       else
 720         {
 721           if (fragment_first >= candidate_vnb->ip.reass.range_first &&
 722               fragment_last <= candidate_vnb->ip.reass.range_last)
 723             {
 724               // this fragment is a (sub)part of existing range, ignore it
 725               if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 726                 {
 727                   ip4_reass_add_trace (vm, node, rm, reass, *bi0,
 728                                        RANGE_OVERLAP, 0);
 729                 }
 730               break;
 731             }
 732           int discard_candidate = 0;
 733           if (fragment_first < candidate_vnb->ip.reass.range_first)
 734             {
 735               u32 overlap =
 736                 fragment_last - candidate_vnb->ip.reass.range_first + 1;
 737               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 738                 {
 739                   candidate_vnb->ip.reass.range_first += overlap;
 740                   ASSERT (reass->data_len >= overlap);
 741                   reass->data_len -= overlap;
 742                   if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 743                     {
 744                       ip4_reass_add_trace (vm, node, rm, reass,
 745                                            candidate_range_bi, RANGE_SHRINK,
 746                                            overlap);
 747                     }
 748                   ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 749                                                    prev_range_bi, *bi0);
 750                   consumed = 1;
 751                 }
 752               else
 753                 {
 754                   discard_candidate = 1;
 755                 }
 756             }
 757           else if (fragment_last > candidate_vnb->ip.reass.range_last)
 758             {
 759               u32 overlap =
 760                 candidate_vnb->ip.reass.range_last - fragment_first + 1;
 761               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 762                 {
 763                   fvnb->ip.reass.range_first += overlap;
 764                   if (~0 != candidate_vnb->ip.reass.next_range_bi)
 765                     {
 766                       prev_range_bi = candidate_range_bi;
 767                       candidate_range_bi =
 768                         candidate_vnb->ip.reass.next_range_bi;
 769                       continue;
 770                     }
 771                   else
 772                     {
 773                       // special case - last range discarded
 774                       ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 775                                                        candidate_range_bi,
 776                                                        *bi0);
 777                       consumed = 1;
 778                     }
 779                 }
 780               else
 781                 {
 782                   discard_candidate = 1;
 783                 }
 784             }
 785           else
 786             {
 787               discard_candidate = 1;
 788             }
 789           if (discard_candidate)
 790             {
 791               u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi;
 792               // discard candidate range, probe next range
 793               ip4_reass_remove_range_from_chain (vm, node, rm,
 794                                                  vec_drop_overlap, reass,
 795                                                  prev_range_bi,
 796                                                  candidate_range_bi);
 797               if (~0 != next_range_bi)
 798                 {
 799                   candidate_range_bi = next_range_bi;
 800                   continue;
 801                 }
 802               else
 803                 {
 804                   // special case - last range discarded
 805                   ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 806                                                    prev_range_bi, *bi0);
 807                   consumed = 1;
 808                 }
 809             }
 810         }
 811       break;
 812     }
 813   if (consumed)
 814     {
 815       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 816         {
 817           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 818         }
 819     }
 820   if (~0 != reass->last_packet_octet &&
 821       reass->data_len == reass->last_packet_octet + 1)
 822     {
 823       ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 824                           vec_drop_compress, vec_drop_overlap, is_feature);
 825     }
 826   else
 827     {
 828       if (consumed)
 829         {
 830           *bi0 = ~0;
 831         }
 832       else
 833         {
 834           *next0 = IP4_REASSEMBLY_NEXT_DROP;
 835           *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT;
 836         }
 837     }
 838 }
 839
 840 always_inline uword
 841 ip4_reassembly_inline (vlib_main_t * vm,
 842                        vlib_node_runtime_t * node,
 843                        vlib_frame_t * frame, bool is_feature)
 844 {
 845   u32 *from = vlib_frame_vector_args (frame);
 846   u32 n_left_from, n_left_to_next, *to_next, next_index;
 847   ip4_reass_main_t *rm = &ip4_reass_main;
 848   ip4_reass_per_thread_t *rt = &rm->per_thread_data[os_get_thread_index ()];
 849   clib_spinlock_lock (&rt->lock);
 850
 851   n_left_from = frame->n_vectors;
 852   next_index = node->cached_next_index;
 853   static u32 *vec_drop_timeout = NULL;  // indexes of buffers which timed out
 854   static u32 *vec_drop_overlap = NULL;  // indexes of buffers which were discarded due to overlap
 855   static u32 *vec_drop_compress = NULL; // indexes of buffers dicarded due to buffer compression
 856   while (n_left_from > 0 || vec_len (vec_drop_timeout) > 0 ||
 857          vec_len (vec_drop_overlap) > 0 || vec_len (vec_drop_compress) > 0)
 858     {
 859       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 860
 861       while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
 862         {
 863           u32 bi = vec_pop (vec_drop_timeout);
 864           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 865           b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
 866           to_next[0] = bi;
 867           to_next += 1;
 868           n_left_to_next -= 1;
 869           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 870                                            n_left_to_next, bi,
 871                                            IP4_REASSEMBLY_NEXT_DROP);
 872           IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout);
 873           ASSERT (rt->buffers_n > 0);
 874           --rt->buffers_n;
 875         }
 876
 877       while (vec_len (vec_drop_overlap) > 0 && n_left_to_next > 0)
 878         {
 879           u32 bi = vec_pop (vec_drop_overlap);
 880           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 881           b->error = node->errors[IP4_ERROR_REASS_DUPLICATE_FRAGMENT];
 882           to_next[0] = bi;
 883           to_next += 1;
 884           n_left_to_next -= 1;
 885           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 886                                            n_left_to_next, bi,
 887                                            IP4_REASSEMBLY_NEXT_DROP);
 888           IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_duplicate_fragment);
 889           ASSERT (rt->buffers_n > 0);
 890           --rt->buffers_n;
 891         }
 892
 893       while (vec_len (vec_drop_compress) > 0 && n_left_to_next > 0)
 894         {
 895           u32 bi = vec_pop (vec_drop_compress);
 896           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 897           b->error = node->errors[IP4_ERROR_NONE];
 898           to_next[0] = bi;
 899           to_next += 1;
 900           n_left_to_next -= 1;
 901           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 902                                            n_left_to_next, bi,
 903                                            IP4_REASSEMBLY_NEXT_DROP);
 904           IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_compress);
 905           ASSERT (rt->buffers_n > 0);
 906           --rt->buffers_n;
 907         }
 908
 909       while (n_left_from > 0 && n_left_to_next > 0)
 910         {
 911           u32 bi0;
 912           vlib_buffer_t *b0;
 913           u32 next0;
 914           u32 error0 = IP4_ERROR_NONE;
 915
 916           bi0 = from[0];
 917           b0 = vlib_get_buffer (vm, bi0);
 918
 919           ip4_header_t *ip0 = vlib_buffer_get_current (b0);
 920           if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
 921             {
 922               // this is a whole packet - no fragmentation
 923               if (is_feature)
 924                 {
 925                   next0 = IP4_REASSEMBLY_NEXT_INPUT;
 926                 }
 927               else
 928                 {
 929                   next0 = vnet_buffer (b0)->ip.reass.next_index;
 930                 }
 931             }
 932           else
 933             {
 934               ip4_reass_key_t k;
 935               k.src.as_u32 = ip0->src_address.as_u32;
 936               k.dst.as_u32 = ip0->dst_address.as_u32;
 937               k.xx_id = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 938               k.frag_id = ip0->fragment_id;
 939               k.proto = ip0->protocol;
 940               k.unused = 0;
 941               ip4_reass_t *reass =
 942                 ip4_reass_find_or_create (vm, rm, rt, &k, &vec_drop_timeout);
 943
 944               if (reass)
 945                 {
 946                   ip4_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
 947                                     &error0, &vec_drop_overlap,
 948                                     &vec_drop_compress, is_feature);
 949                 }
 950               else
 951                 {
 952                   next0 = IP4_REASSEMBLY_NEXT_DROP;
 953                   error0 = IP4_ERROR_REASS_LIMIT_REACHED;
 954                 }
 955
 956               b0->error = node->errors[error0];
 957             }
 958
 959           if (bi0 != ~0)
 960             {
 961               to_next[0] = bi0;
 962               to_next += 1;
 963               n_left_to_next -= 1;
 964               if (is_feature && IP4_ERROR_NONE == error0)
 965                 {
 966                   vnet_feature_next (vnet_buffer (b0)->sw_if_index[VLIB_RX],
 967                                      &next0, b0);
 968                 }
 969               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 970                                                n_left_to_next, bi0, next0);
 971               IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next);
 972             }
 973
 974           from += 1;
 975           n_left_from -= 1;
 976         }
 977
 978       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 979     }
 980
 981   clib_spinlock_unlock (&rt->lock);
 982   return frame->n_vectors;
 983 }
 984
 985 static char *ip4_reassembly_error_strings[] = {
 986 #define _(sym, string) string,
 987   foreach_ip4_error
 988 #undef _
 989 };
 990
 991 always_inline uword
 992 ip4_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
 993                 vlib_frame_t * frame)
 994 {
 995   return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ );
 996 }
 997
 998 /* *INDENT-OFF* */
 999 VLIB_REGISTER_NODE (ip4_reass_node, static) = {
1000     .function = ip4_reassembly,
1001     .name = "ip4-reassembly",
1002     .vector_size = sizeof (u32),
1003     .format_trace = format_ip4_reass_trace,
1004     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1005     .error_strings = ip4_reassembly_error_strings,
1006     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1007     .next_nodes =
1008         {
1009                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1010                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1011         },
1012 };
1013 /* *INDENT-ON* */
1014
1015 VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node, ip4_reassembly);
1016
1017 always_inline uword
1018 ip4_reassembly_feature (vlib_main_t * vm,
1019                         vlib_node_runtime_t * node, vlib_frame_t * frame)
1020 {
1021   return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ );
1022 }
1023
1024 /* *INDENT-OFF* */
1025 VLIB_REGISTER_NODE (ip4_reass_node_feature, static) = {
1026     .function = ip4_reassembly_feature,
1027     .name = "ip4-reassembly-feature",
1028     .vector_size = sizeof (u32),
1029     .format_trace = format_ip4_reass_trace,
1030     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1031     .error_strings = ip4_reassembly_error_strings,
1032     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1033     .next_nodes =
1034         {
1035                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1036                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1037         },
1038 };
1039 /* *INDENT-ON* */
1040
1041 VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node_feature, ip4_reassembly_feature);
1042
1043 /* *INDENT-OFF* */
1044 VNET_FEATURE_INIT (ip4_reassembly_feature, static) = {
1045     .arc_name = "ip4-unicast",
1046     .node_name = "ip4-reassembly-feature",
1047     .runs_before = VNET_FEATURES ("ip4-lookup"),
1048     .runs_after = 0,
1049 };
1050 /* *INDENT-ON* */
1051
1052 always_inline u32
1053 ip4_reass_get_nbuckets ()
1054 {
1055   ip4_reass_main_t *rm = &ip4_reass_main;
1056   u32 nbuckets;
1057   u8 i;
1058
1059   nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR);
1060
1061   for (i = 0; i < 31; i++)
1062     if ((1 << i) >= nbuckets)
1063       break;
1064   nbuckets = 1 << i;
1065
1066   return nbuckets;
1067 }
1068
1069 typedef enum
1070 {
1071   IP4_EVENT_CONFIG_CHANGED = 1,
1072 } ip4_reass_event_t;
1073
1074 typedef struct
1075 {
1076   int failure;
1077   clib_bihash_24_8_t *new_hash;
1078 } ip4_rehash_cb_ctx;
1079
1080 static void
1081 ip4_rehash_cb (clib_bihash_kv_24_8_t * kv, void *_ctx)
1082 {
1083   ip4_rehash_cb_ctx *ctx = _ctx;
1084   if (clib_bihash_add_del_24_8 (ctx->new_hash, kv, 1))
1085     {
1086       ctx->failure = 1;
1087     }
1088 }
1089
1090 static void
1091 ip4_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1092                       u32 expire_walk_interval_ms)
1093 {
1094   ip4_reass_main.timeout_ms = timeout_ms;
1095   ip4_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1096   ip4_reass_main.max_reass_n = max_reassemblies;
1097   ip4_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1098 }
1099
1100 vnet_api_error_t
1101 ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
1102                u32 expire_walk_interval_ms)
1103 {
1104   u32 old_nbuckets = ip4_reass_get_nbuckets ();
1105   ip4_reass_set_params (timeout_ms, max_reassemblies,
1106                         expire_walk_interval_ms);
1107   vlib_process_signal_event (ip4_reass_main.vlib_main,
1108                              ip4_reass_main.ip4_reass_expire_node_idx,
1109                              IP4_EVENT_CONFIG_CHANGED, 0);
1110   u32 new_nbuckets = ip4_reass_get_nbuckets ();
1111   if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > 1 &&
1112       new_nbuckets != old_nbuckets)
1113     {
1114       clib_bihash_24_8_t new_hash;
1115       memset (&new_hash, 0, sizeof (new_hash));
1116       ip4_rehash_cb_ctx ctx;
1117       ctx.failure = 0;
1118       ctx.new_hash = &new_hash;
1119       clib_bihash_init_24_8 (&new_hash, "ip4-reass", new_nbuckets,
1120                              new_nbuckets * 1024);
1121       clib_bihash_foreach_key_value_pair_24_8 (&ip4_reass_main.hash,
1122                                                ip4_rehash_cb, &ctx);
1123       if (ctx.failure)
1124         {
1125           clib_bihash_free_24_8 (&new_hash);
1126           return -1;
1127         }
1128       else
1129         {
1130           clib_bihash_free_24_8 (&ip4_reass_main.hash);
1131           clib_memcpy (&ip4_reass_main.hash, &new_hash,
1132                        sizeof (ip4_reass_main.hash));
1133         }
1134     }
1135   return 0;
1136 }
1137
1138 vnet_api_error_t
1139 ip4_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1140                u32 * expire_walk_interval_ms)
1141 {
1142   *timeout_ms = ip4_reass_main.timeout_ms;
1143   *max_reassemblies = ip4_reass_main.max_reass_n;
1144   *expire_walk_interval_ms = ip4_reass_main.expire_walk_interval_ms;
1145   return 0;
1146 }
1147
1148 static clib_error_t *
1149 ip4_reass_init_function (vlib_main_t * vm)
1150 {
1151   ip4_reass_main_t *rm = &ip4_reass_main;
1152   clib_error_t *error = 0;
1153   u32 nbuckets;
1154   vlib_node_t *node;
1155
1156   rm->vlib_main = vm;
1157   rm->vnet_main = vnet_get_main ();
1158
1159   vec_validate (rm->per_thread_data, vlib_num_workers () + 1);
1160   ip4_reass_per_thread_t *rt;
1161   vec_foreach (rt, rm->per_thread_data)
1162   {
1163     clib_spinlock_init (&rt->lock);
1164     pool_alloc (rt->pool, rm->max_reass_n);
1165   }
1166
1167   node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk");
1168   ASSERT (node);
1169   rm->ip4_reass_expire_node_idx = node->index;
1170
1171   nbuckets = ip4_reass_get_nbuckets ();
1172   clib_bihash_init_24_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024);
1173
1174   node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
1175   ASSERT (node);
1176   rm->ip4_drop_idx = node->index;
1177
1178   ip4_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS,
1179                         IP4_REASS_MAX_REASSEMBLIES_DEFAULT,
1180                         IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1181
1182   return error;
1183 }
1184
1185 VLIB_INIT_FUNCTION (ip4_reass_init_function);
1186
1187 static uword
1188 ip4_reass_walk_expired (vlib_main_t * vm,
1189                         vlib_node_runtime_t * node, vlib_frame_t * f)
1190 {
1191   ip4_reass_main_t *rm = &ip4_reass_main;
1192   uword event_type, *event_data = 0;
1193
1194   while (true)
1195     {
1196       vlib_process_wait_for_event_or_clock (vm,
1197                                             (f64) rm->expire_walk_interval_ms
1198                                             / (f64) MSEC_PER_SEC);
1199       event_type = vlib_process_get_events (vm, &event_data);
1200
1201       switch (event_type)
1202         {
1203         case ~0:                /* no events => timeout */
1204           /* nothing to do here */
1205           break;
1206         case IP4_EVENT_CONFIG_CHANGED:
1207           break;
1208         default:
1209           clib_warning ("BUG: event type 0x%wx", event_type);
1210           break;
1211         }
1212       f64 now = vlib_time_now (vm);
1213
1214       ip4_reass_t *reass;
1215       u32 *vec_drop_timeout = NULL;
1216       int *pool_indexes_to_free = NULL;
1217
1218       uword thread_index = 0;
1219       int index;
1220       const uword nthreads = os_get_nthreads ();
1221       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1222         {
1223           ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1224           clib_spinlock_lock (&rt->lock);
1225
1226           vec_reset_length (pool_indexes_to_free);
1227           /* *INDENT-OFF* */
1228           pool_foreach_index (index, rt->pool, ({
1229                                 reass = pool_elt_at_index (rt->pool, index);
1230                                 if (now > reass->last_heard + rm->timeout)
1231                                   {
1232                                     vec_add1 (pool_indexes_to_free, index);
1233                                   }
1234                               }));
1235           /* *INDENT-ON* */
1236           int *i;
1237           /* *INDENT-OFF* */
1238           vec_foreach (i, pool_indexes_to_free)
1239           {
1240             ip4_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1241             u32 before = vec_len (vec_drop_timeout);
1242             vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
1243             if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1244               {
1245                 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1246                                         b->trace_index))
1247                   {
1248                     /* the trace is gone, don't trace this buffer anymore */
1249                     b->flags &= ~VLIB_BUFFER_IS_TRACED;
1250                   }
1251               }
1252             ip4_reass_on_timeout (vm, rm, reass, &vec_drop_timeout);
1253             u32 after = vec_len (vec_drop_timeout);
1254             ASSERT (rt->buffers_n >= (after - before));
1255             rt->buffers_n -= (after - before);
1256             ip4_reass_free (rm, rt, reass);
1257           }
1258           /* *INDENT-ON* */
1259
1260           clib_spinlock_unlock (&rt->lock);
1261         }
1262
1263       while (vec_len (vec_drop_timeout) > 0)
1264         {
1265           vlib_frame_t *f = vlib_get_frame_to_node (vm, rm->ip4_drop_idx);
1266           u32 *to_next = vlib_frame_vector_args (f);
1267           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1268           int trace_frame = 0;
1269           while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
1270             {
1271               u32 bi = vec_pop (vec_drop_timeout);
1272               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1273               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1274                 {
1275                   if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1276                                           b->trace_index))
1277                     {
1278                       /* the trace is gone, don't trace this buffer anymore */
1279                       b->flags &= ~VLIB_BUFFER_IS_TRACED;
1280                     }
1281                   else
1282                     {
1283                       trace_frame = 1;
1284                     }
1285                 }
1286               b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
1287               to_next[0] = bi;
1288               ++f->n_vectors;
1289               to_next += 1;
1290               n_left_to_next -= 1;
1291               IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout_walk);
1292             }
1293           f->flags |= (trace_frame * VLIB_FRAME_TRACE);
1294           vlib_put_frame_to_node (vm, rm->ip4_drop_idx, f);
1295         }
1296
1297       vec_free (pool_indexes_to_free);
1298       vec_free (vec_drop_timeout);
1299       if (event_data)
1300         {
1301           _vec_len (event_data) = 0;
1302         }
1303     }
1304
1305   return 0;
1306 }
1307
1308 static vlib_node_registration_t ip4_reass_expire_node;
1309
1310 /* *INDENT-OFF* */
1311 VLIB_REGISTER_NODE (ip4_reass_expire_node, static) = {
1312     .function = ip4_reass_walk_expired,
1313     .type = VLIB_NODE_TYPE_PROCESS,
1314     .name = "ip4-reassembly-expire-walk",
1315     .format_trace = format_ip4_reass_trace,
1316     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1317     .error_strings = ip4_reassembly_error_strings,
1318
1319 };
1320 /* *INDENT-ON* */
1321
1322 static u8 *
1323 format_ip4_reass_key (u8 * s, va_list * args)
1324 {
1325   ip4_reass_key_t *key = va_arg (*args, ip4_reass_key_t *);
1326   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1327               key->xx_id, format_ip4_address, &key->src, format_ip4_address,
1328               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1329   return s;
1330 }
1331
1332 static u8 *
1333 format_ip4_reass (u8 * s, va_list * args)
1334 {
1335   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1336   ip4_reass_t *reass = va_arg (*args, ip4_reass_t *);
1337
1338   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1339               "last_packet_octet: %u, trace_op_counter: %u\n",
1340               reass->id, format_ip4_reass_key, &reass->key, reass->first_bi,
1341               reass->data_len, reass->last_packet_octet,
1342               reass->trace_op_counter);
1343   u32 bi = reass->first_bi;
1344   u32 counter = 0;
1345   while (~0 != bi)
1346     {
1347       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1348       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1349       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1350                   "fragment[%u, %u]\n",
1351                   counter, vnb->ip.reass.range_first,
1352                   vnb->ip.reass.range_last, bi,
1353                   ip4_reass_buffer_get_data_offset_no_check (b),
1354                   ip4_reass_buffer_get_data_len_no_check (b),
1355                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1356       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1357         {
1358           bi = b->next_buffer;
1359         }
1360       else
1361         {
1362           bi = ~0;
1363         }
1364     }
1365   return s;
1366 }
1367
1368 static clib_error_t *
1369 show_ip4_reass (vlib_main_t * vm, unformat_input_t * input,
1370                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1371 {
1372   ip4_reass_main_t *rm = &ip4_reass_main;
1373
1374   vlib_cli_output (vm, "---------------------");
1375   vlib_cli_output (vm, "IP4 reassembly status");
1376   vlib_cli_output (vm, "---------------------");
1377   bool details = false;
1378   if (unformat (input, "details"))
1379     {
1380       details = true;
1381     }
1382
1383   u32 sum_reass_n = 0;
1384   u64 sum_buffers_n = 0;
1385   ip4_reass_t *reass;
1386   uword thread_index;
1387   const uword nthreads = os_get_nthreads ();
1388   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1389     {
1390       ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1391       clib_spinlock_lock (&rt->lock);
1392       if (details)
1393         {
1394           /* *INDENT-OFF* */
1395           pool_foreach (reass, rt->pool, {
1396             vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass);
1397           });
1398           /* *INDENT-ON* */
1399         }
1400       sum_reass_n += rt->reass_n;
1401       sum_buffers_n += rt->buffers_n;
1402       clib_spinlock_unlock (&rt->lock);
1403     }
1404   vlib_cli_output (vm, "---------------------");
1405   vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
1406                    (long unsigned) sum_reass_n);
1407   vlib_cli_output (vm,
1408                    "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
1409                    (long unsigned) rm->max_reass_n);
1410   vlib_cli_output (vm, "Buffers in use: %lu\n",
1411                    (long unsigned) sum_buffers_n);
1412   return 0;
1413 }
1414
1415 /* *INDENT-OFF* */
1416 VLIB_CLI_COMMAND (show_ip4_reassembly_cmd, static) = {
1417     .path = "show ip4-reassembly",
1418     .short_help = "show ip4-reassembly [details]",
1419     .function = show_ip4_reass,
1420 };
1421 /* *INDENT-ON* */
1422
1423 vnet_api_error_t
1424 ip4_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1425 {
1426   return vnet_feature_enable_disable ("ip4-unicast", "ip4-reassembly-feature",
1427                                       sw_if_index, enable_disable, 0, 0);
1428 }
1429
1430 /*
1431  * fd.io coding-style-patch-verification: ON
1432  *
1433  * Local Variables:
1434  * eval: (c-set-style "gnu")
1435  * End:
1436  */