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
 501   ASSERT (last_b != NULL);
 502   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 503   ASSERT (rt->buffers_n >= (buf_cnt - dropped_cnt));
 504   rt->buffers_n -= buf_cnt - dropped_cnt;
 505   ASSERT (total_length >= first_b->current_length);
 506   total_length -= first_b->current_length;
 507   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 508   first_b->total_length_not_including_first_buffer = total_length;
 509   ip4_header_t *ip = vlib_buffer_get_current (first_b);
 510   ip->flags_and_fragment_offset = 0;
 511   ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
 512   ip->checksum = ip4_header_checksum (ip);
 513   vlib_buffer_chain_compress (vm, first_b, vec_drop_compress);
 514   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 515     {
 516       ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 517 #if 0
 518       // following code does a hexdump of packet fragments to stdout ...
 519       do
 520         {
 521           u32 bi = reass->first_bi;
 522           u8 *s = NULL;
 523           while (~0 != bi)
 524             {
 525               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 526               s = format (s, "%u: %U\n", bi, format_hexdump,
 527                           vlib_buffer_get_current (b), b->current_length);
 528               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 529                 {
 530                   bi = b->next_buffer;
 531                 }
 532               else
 533                 {
 534                   break;
 535                 }
 536             }
 537           printf ("%.*s\n", vec_len (s), s);
 538           fflush (stdout);
 539           vec_free (s);
 540         }
 541       while (0);
 542 #endif
 543     }
 544   *bi0 = reass->first_bi;
 545   if (is_feature)
 546     {
 547       *next0 = IP4_REASSEMBLY_NEXT_INPUT;
 548     }
 549   else
 550     {
 551       *next0 = reass->next_index;
 552     }
 553   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 554   *error0 = IP4_ERROR_NONE;
 555   ip4_reass_free (rm, rt, reass);
 556   reass = NULL;
 557 }
 558
 559 always_inline u32
 560 ip4_reass_get_buffer_chain_length (vlib_main_t * vm, vlib_buffer_t * b)
 561 {
 562   u32 len = 0;
 563   while (b)
 564     {
 565       ++len;
 566       if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
 567         {
 568           b = vlib_get_buffer (vm, b->next_buffer);
 569         }
 570       else
 571         {
 572           break;
 573         }
 574     }
 575   return len;
 576 }
 577
 578 always_inline void
 579 ip4_reass_insert_range_in_chain (vlib_main_t * vm,
 580                                  ip4_reass_main_t * rm,
 581                                  ip4_reass_per_thread_t * rt,
 582                                  ip4_reass_t * reass,
 583                                  u32 prev_range_bi, u32 new_next_bi)
 584 {
 585
 586   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 587   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 588   if (~0 != prev_range_bi)
 589     {
 590       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 591       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 592       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 593       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 594     }
 595   else
 596     {
 597       if (~0 != reass->first_bi)
 598         {
 599           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 600         }
 601       reass->first_bi = new_next_bi;
 602     }
 603   reass->data_len += ip4_reass_buffer_get_data_len (new_next_b);
 604   rt->buffers_n += ip4_reass_get_buffer_chain_length (vm, new_next_b);
 605 }
 606
 607 always_inline void
 608 ip4_reass_remove_range_from_chain (vlib_main_t * vm,
 609                                    vlib_node_runtime_t * node,
 610                                    ip4_reass_main_t * rm,
 611                                    u32 ** vec_drop_overlap,
 612                                    ip4_reass_t * reass, u32 prev_range_bi,
 613                                    u32 discard_bi)
 614 {
 615   vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi);
 616   vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b);
 617   if (~0 != prev_range_bi)
 618     {
 619       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 620       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 621       ASSERT (prev_vnb->ip.reass.next_range_bi == discard_bi);
 622       prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi;
 623     }
 624   else
 625     {
 626       reass->first_bi = discard_vnb->ip.reass.next_range_bi;
 627     }
 628   reass->data_len -= ip4_reass_buffer_get_data_len (discard_b);
 629   while (1)
 630     {
 631       vec_add1 (*vec_drop_overlap, discard_bi);
 632       if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED))
 633         {
 634           ip4_reass_add_trace (vm, node, rm, reass, discard_bi, RANGE_DISCARD,
 635                                0);
 636         }
 637       if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT)
 638         {
 639           discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 640           discard_bi = discard_b->next_buffer;
 641           discard_b = vlib_get_buffer (vm, discard_bi);
 642         }
 643       else
 644         {
 645           break;
 646         }
 647     }
 648 }
 649
 650 always_inline void
 651 ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 652                   ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 653                   ip4_reass_t * reass, u32 * bi0, u32 * next0,
 654                   vlib_error_t * error0, u32 ** vec_drop_overlap,
 655                   u32 ** vec_drop_compress, bool is_feature)
 656 {
 657   int consumed = 0;
 658   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 659   ip4_header_t *fip = vlib_buffer_get_current (fb);
 660   ASSERT (fb->current_length >= sizeof (*fip));
 661   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 662   u32 fragment_first = fvnb->ip.reass.fragment_first =
 663     ip4_get_fragment_offset_bytes (fip);
 664   u32 fragment_length =
 665     clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
 666   u32 fragment_last = fvnb->ip.reass.fragment_last =
 667     fragment_first + fragment_length - 1;
 668   int more_fragments = ip4_get_fragment_more (fip);
 669   u32 candidate_range_bi = reass->first_bi;
 670   u32 prev_range_bi = ~0;
 671   reass->next_index = fvnb->ip.reass.next_index;        // store next_index before it's overwritten
 672   fvnb->ip.reass.range_first = fragment_first;
 673   fvnb->ip.reass.range_last = fragment_last;
 674   fvnb->ip.reass.next_range_bi = ~0;
 675   if (!more_fragments)
 676     {
 677       reass->last_packet_octet = fragment_last;
 678     }
 679   if (~0 == reass->first_bi)
 680     {
 681       // starting a new reassembly
 682       ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 683                                        *bi0);
 684       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 685         {
 686           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 687         }
 688       *bi0 = ~0;
 689       reass->min_fragment_length = clib_net_to_host_u16 (fip->length);
 690       return;
 691     }
 692   reass->min_fragment_length = clib_min (clib_net_to_host_u16 (fip->length),
 693                                          fvnb->ip.reass.estimated_mtu);
 694   while (~0 != candidate_range_bi)
 695     {
 696       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 697       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 698       if (fragment_first > candidate_vnb->ip.reass.range_last)
 699         {
 700           // this fragments starts after candidate range
 701           prev_range_bi = candidate_range_bi;
 702           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 703           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 704               ~0 == candidate_range_bi)
 705             {
 706               // special case - this fragment falls beyond all known ranges
 707               ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 708                                                prev_range_bi, *bi0);
 709               consumed = 1;
 710               break;
 711             }
 712           continue;
 713         }
 714       if (fragment_last < candidate_vnb->ip.reass.range_first)
 715         {
 716           // this fragment ends before candidate range without any overlap
 717           ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 718                                            *bi0);
 719           consumed = 1;
 720         }
 721       else
 722         {
 723           if (fragment_first >= candidate_vnb->ip.reass.range_first &&
 724               fragment_last <= candidate_vnb->ip.reass.range_last)
 725             {
 726               // this fragment is a (sub)part of existing range, ignore it
 727               if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 728                 {
 729                   ip4_reass_add_trace (vm, node, rm, reass, *bi0,
 730                                        RANGE_OVERLAP, 0);
 731                 }
 732               break;
 733             }
 734           int discard_candidate = 0;
 735           if (fragment_first < candidate_vnb->ip.reass.range_first)
 736             {
 737               u32 overlap =
 738                 fragment_last - candidate_vnb->ip.reass.range_first + 1;
 739               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 740                 {
 741                   candidate_vnb->ip.reass.range_first += overlap;
 742                   ASSERT (reass->data_len >= overlap);
 743                   reass->data_len -= overlap;
 744                   if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 745                     {
 746                       ip4_reass_add_trace (vm, node, rm, reass,
 747                                            candidate_range_bi, RANGE_SHRINK,
 748                                            overlap);
 749                     }
 750                   ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 751                                                    prev_range_bi, *bi0);
 752                   consumed = 1;
 753                 }
 754               else
 755                 {
 756                   discard_candidate = 1;
 757                 }
 758             }
 759           else if (fragment_last > candidate_vnb->ip.reass.range_last)
 760             {
 761               u32 overlap =
 762                 candidate_vnb->ip.reass.range_last - fragment_first + 1;
 763               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 764                 {
 765                   fvnb->ip.reass.range_first += overlap;
 766                   if (~0 != candidate_vnb->ip.reass.next_range_bi)
 767                     {
 768                       prev_range_bi = candidate_range_bi;
 769                       candidate_range_bi =
 770                         candidate_vnb->ip.reass.next_range_bi;
 771                       continue;
 772                     }
 773                   else
 774                     {
 775                       // special case - last range discarded
 776                       ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 777                                                        candidate_range_bi,
 778                                                        *bi0);
 779                       consumed = 1;
 780                     }
 781                 }
 782               else
 783                 {
 784                   discard_candidate = 1;
 785                 }
 786             }
 787           else
 788             {
 789               discard_candidate = 1;
 790             }
 791           if (discard_candidate)
 792             {
 793               u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi;
 794               // discard candidate range, probe next range
 795               ip4_reass_remove_range_from_chain (vm, node, rm,
 796                                                  vec_drop_overlap, reass,
 797                                                  prev_range_bi,
 798                                                  candidate_range_bi);
 799               if (~0 != next_range_bi)
 800                 {
 801                   candidate_range_bi = next_range_bi;
 802                   continue;
 803                 }
 804               else
 805                 {
 806                   // special case - last range discarded
 807                   ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 808                                                    prev_range_bi, *bi0);
 809                   consumed = 1;
 810                 }
 811             }
 812         }
 813       break;
 814     }
 815   if (consumed)
 816     {
 817       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 818         {
 819           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 820         }
 821     }
 822   if (~0 != reass->last_packet_octet &&
 823       reass->data_len == reass->last_packet_octet + 1)
 824     {
 825       ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 826                           vec_drop_compress, vec_drop_overlap, is_feature);
 827     }
 828   else
 829     {
 830       if (consumed)
 831         {
 832           *bi0 = ~0;
 833         }
 834       else
 835         {
 836           *next0 = IP4_REASSEMBLY_NEXT_DROP;
 837           *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT;
 838         }
 839     }
 840 }
 841
 842 always_inline uword
 843 ip4_reassembly_inline (vlib_main_t * vm,
 844                        vlib_node_runtime_t * node,
 845                        vlib_frame_t * frame, bool is_feature)
 846 {
 847   u32 *from = vlib_frame_vector_args (frame);
 848   u32 n_left_from, n_left_to_next, *to_next, next_index;
 849   ip4_reass_main_t *rm = &ip4_reass_main;
 850   ip4_reass_per_thread_t *rt = &rm->per_thread_data[os_get_thread_index ()];
 851   clib_spinlock_lock (&rt->lock);
 852
 853   n_left_from = frame->n_vectors;
 854   next_index = node->cached_next_index;
 855   static u32 *vec_drop_timeout = NULL;  // indexes of buffers which timed out
 856   static u32 *vec_drop_overlap = NULL;  // indexes of buffers which were discarded due to overlap
 857   static u32 *vec_drop_compress = NULL; // indexes of buffers dicarded due to buffer compression
 858   while (n_left_from > 0 || vec_len (vec_drop_timeout) > 0 ||
 859          vec_len (vec_drop_overlap) > 0 || vec_len (vec_drop_compress) > 0)
 860     {
 861       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 862
 863       while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
 864         {
 865           u32 bi = vec_pop (vec_drop_timeout);
 866           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 867           b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
 868           to_next[0] = bi;
 869           to_next += 1;
 870           n_left_to_next -= 1;
 871           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 872                                            n_left_to_next, bi,
 873                                            IP4_REASSEMBLY_NEXT_DROP);
 874           IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout);
 875           ASSERT (rt->buffers_n > 0);
 876           --rt->buffers_n;
 877         }
 878
 879       while (vec_len (vec_drop_overlap) > 0 && n_left_to_next > 0)
 880         {
 881           u32 bi = vec_pop (vec_drop_overlap);
 882           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 883           b->error = node->errors[IP4_ERROR_REASS_DUPLICATE_FRAGMENT];
 884           to_next[0] = bi;
 885           to_next += 1;
 886           n_left_to_next -= 1;
 887           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 888                                            n_left_to_next, bi,
 889                                            IP4_REASSEMBLY_NEXT_DROP);
 890           IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_duplicate_fragment);
 891           ASSERT (rt->buffers_n > 0);
 892           --rt->buffers_n;
 893         }
 894
 895       while (vec_len (vec_drop_compress) > 0 && n_left_to_next > 0)
 896         {
 897           u32 bi = vec_pop (vec_drop_compress);
 898           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 899           b->error = node->errors[IP4_ERROR_NONE];
 900           to_next[0] = bi;
 901           to_next += 1;
 902           n_left_to_next -= 1;
 903           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 904                                            n_left_to_next, bi,
 905                                            IP4_REASSEMBLY_NEXT_DROP);
 906           IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_compress);
 907           ASSERT (rt->buffers_n > 0);
 908           --rt->buffers_n;
 909         }
 910
 911       while (n_left_from > 0 && n_left_to_next > 0)
 912         {
 913           u32 bi0;
 914           vlib_buffer_t *b0;
 915           u32 next0;
 916           u32 error0 = IP4_ERROR_NONE;
 917
 918           bi0 = from[0];
 919           b0 = vlib_get_buffer (vm, bi0);
 920
 921           ip4_header_t *ip0 = vlib_buffer_get_current (b0);
 922           if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
 923             {
 924               // this is a whole packet - no fragmentation
 925               if (is_feature)
 926                 {
 927                   next0 = IP4_REASSEMBLY_NEXT_INPUT;
 928                 }
 929               else
 930                 {
 931                   next0 = vnet_buffer (b0)->ip.reass.next_index;
 932                 }
 933             }
 934           else
 935             {
 936               ip4_reass_key_t k;
 937               k.src.as_u32 = ip0->src_address.as_u32;
 938               k.dst.as_u32 = ip0->dst_address.as_u32;
 939               k.xx_id = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 940               k.frag_id = ip0->fragment_id;
 941               k.proto = ip0->protocol;
 942               k.unused = 0;
 943               ip4_reass_t *reass =
 944                 ip4_reass_find_or_create (vm, rm, rt, &k, &vec_drop_timeout);
 945
 946               if (reass)
 947                 {
 948                   ip4_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
 949                                     &error0, &vec_drop_overlap,
 950                                     &vec_drop_compress, is_feature);
 951                 }
 952               else
 953                 {
 954                   next0 = IP4_REASSEMBLY_NEXT_DROP;
 955                   error0 = IP4_ERROR_REASS_LIMIT_REACHED;
 956                 }
 957
 958               b0->error = node->errors[error0];
 959             }
 960
 961           if (bi0 != ~0)
 962             {
 963               to_next[0] = bi0;
 964               to_next += 1;
 965               n_left_to_next -= 1;
 966               if (is_feature && IP4_ERROR_NONE == error0)
 967                 {
 968                   vnet_feature_next (vnet_buffer (b0)->sw_if_index[VLIB_RX],
 969                                      &next0, b0);
 970                 }
 971               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 972                                                n_left_to_next, bi0, next0);
 973               IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next);
 974             }
 975
 976           from += 1;
 977           n_left_from -= 1;
 978         }
 979
 980       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 981     }
 982
 983   clib_spinlock_unlock (&rt->lock);
 984   return frame->n_vectors;
 985 }
 986
 987 static char *ip4_reassembly_error_strings[] = {
 988 #define _(sym, string) string,
 989   foreach_ip4_error
 990 #undef _
 991 };
 992
 993 always_inline uword
 994 ip4_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
 995                 vlib_frame_t * frame)
 996 {
 997   return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ );
 998 }
 999
1000 /* *INDENT-OFF* */
1001 VLIB_REGISTER_NODE (ip4_reass_node, static) = {
1002     .function = ip4_reassembly,
1003     .name = "ip4-reassembly",
1004     .vector_size = sizeof (u32),
1005     .format_trace = format_ip4_reass_trace,
1006     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1007     .error_strings = ip4_reassembly_error_strings,
1008     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1009     .next_nodes =
1010         {
1011                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1012                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1013         },
1014 };
1015 /* *INDENT-ON* */
1016
1017 VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node, ip4_reassembly);
1018
1019 always_inline uword
1020 ip4_reassembly_feature (vlib_main_t * vm,
1021                         vlib_node_runtime_t * node, vlib_frame_t * frame)
1022 {
1023   return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ );
1024 }
1025
1026 /* *INDENT-OFF* */
1027 VLIB_REGISTER_NODE (ip4_reass_node_feature, static) = {
1028     .function = ip4_reassembly_feature,
1029     .name = "ip4-reassembly-feature",
1030     .vector_size = sizeof (u32),
1031     .format_trace = format_ip4_reass_trace,
1032     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1033     .error_strings = ip4_reassembly_error_strings,
1034     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1035     .next_nodes =
1036         {
1037                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1038                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1039         },
1040 };
1041 /* *INDENT-ON* */
1042
1043 VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node_feature, ip4_reassembly_feature);
1044
1045 /* *INDENT-OFF* */
1046 VNET_FEATURE_INIT (ip4_reassembly_feature, static) = {
1047     .arc_name = "ip4-unicast",
1048     .node_name = "ip4-reassembly-feature",
1049     .runs_before = VNET_FEATURES ("ip4-lookup"),
1050     .runs_after = 0,
1051 };
1052 /* *INDENT-ON* */
1053
1054 always_inline u32
1055 ip4_reass_get_nbuckets ()
1056 {
1057   ip4_reass_main_t *rm = &ip4_reass_main;
1058   u32 nbuckets;
1059   u8 i;
1060
1061   nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR);
1062
1063   for (i = 0; i < 31; i++)
1064     if ((1 << i) >= nbuckets)
1065       break;
1066   nbuckets = 1 << i;
1067
1068   return nbuckets;
1069 }
1070
1071 typedef enum
1072 {
1073   IP4_EVENT_CONFIG_CHANGED = 1,
1074 } ip4_reass_event_t;
1075
1076 typedef struct
1077 {
1078   int failure;
1079   clib_bihash_24_8_t *new_hash;
1080 } ip4_rehash_cb_ctx;
1081
1082 static void
1083 ip4_rehash_cb (clib_bihash_kv_24_8_t * kv, void *_ctx)
1084 {
1085   ip4_rehash_cb_ctx *ctx = _ctx;
1086   if (clib_bihash_add_del_24_8 (ctx->new_hash, kv, 1))
1087     {
1088       ctx->failure = 1;
1089     }
1090 }
1091
1092 static void
1093 ip4_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1094                       u32 expire_walk_interval_ms)
1095 {
1096   ip4_reass_main.timeout_ms = timeout_ms;
1097   ip4_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1098   ip4_reass_main.max_reass_n = max_reassemblies;
1099   ip4_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1100 }
1101
1102 vnet_api_error_t
1103 ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
1104                u32 expire_walk_interval_ms)
1105 {
1106   u32 old_nbuckets = ip4_reass_get_nbuckets ();
1107   ip4_reass_set_params (timeout_ms, max_reassemblies,
1108                         expire_walk_interval_ms);
1109   vlib_process_signal_event (ip4_reass_main.vlib_main,
1110                              ip4_reass_main.ip4_reass_expire_node_idx,
1111                              IP4_EVENT_CONFIG_CHANGED, 0);
1112   u32 new_nbuckets = ip4_reass_get_nbuckets ();
1113   if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > 1 &&
1114       new_nbuckets != old_nbuckets)
1115     {
1116       clib_bihash_24_8_t new_hash;
1117       memset (&new_hash, 0, sizeof (new_hash));
1118       ip4_rehash_cb_ctx ctx;
1119       ctx.failure = 0;
1120       ctx.new_hash = &new_hash;
1121       clib_bihash_init_24_8 (&new_hash, "ip4-reass", new_nbuckets,
1122                              new_nbuckets * 1024);
1123       clib_bihash_foreach_key_value_pair_24_8 (&ip4_reass_main.hash,
1124                                                ip4_rehash_cb, &ctx);
1125       if (ctx.failure)
1126         {
1127           clib_bihash_free_24_8 (&new_hash);
1128           return -1;
1129         }
1130       else
1131         {
1132           clib_bihash_free_24_8 (&ip4_reass_main.hash);
1133           clib_memcpy (&ip4_reass_main.hash, &new_hash,
1134                        sizeof (ip4_reass_main.hash));
1135         }
1136     }
1137   return 0;
1138 }
1139
1140 vnet_api_error_t
1141 ip4_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1142                u32 * expire_walk_interval_ms)
1143 {
1144   *timeout_ms = ip4_reass_main.timeout_ms;
1145   *max_reassemblies = ip4_reass_main.max_reass_n;
1146   *expire_walk_interval_ms = ip4_reass_main.expire_walk_interval_ms;
1147   return 0;
1148 }
1149
1150 static clib_error_t *
1151 ip4_reass_init_function (vlib_main_t * vm)
1152 {
1153   ip4_reass_main_t *rm = &ip4_reass_main;
1154   clib_error_t *error = 0;
1155   u32 nbuckets;
1156   vlib_node_t *node;
1157
1158   rm->vlib_main = vm;
1159   rm->vnet_main = vnet_get_main ();
1160
1161   vec_validate (rm->per_thread_data, vlib_num_workers () + 1);
1162   ip4_reass_per_thread_t *rt;
1163   vec_foreach (rt, rm->per_thread_data)
1164   {
1165     clib_spinlock_init (&rt->lock);
1166     pool_alloc (rt->pool, rm->max_reass_n);
1167   }
1168
1169   node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk");
1170   ASSERT (node);
1171   rm->ip4_reass_expire_node_idx = node->index;
1172
1173   nbuckets = ip4_reass_get_nbuckets ();
1174   clib_bihash_init_24_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024);
1175
1176   node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
1177   ASSERT (node);
1178   rm->ip4_drop_idx = node->index;
1179
1180   ip4_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS,
1181                         IP4_REASS_MAX_REASSEMBLIES_DEFAULT,
1182                         IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1183
1184   return error;
1185 }
1186
1187 VLIB_INIT_FUNCTION (ip4_reass_init_function);
1188
1189 static uword
1190 ip4_reass_walk_expired (vlib_main_t * vm,
1191                         vlib_node_runtime_t * node, vlib_frame_t * f)
1192 {
1193   ip4_reass_main_t *rm = &ip4_reass_main;
1194   uword event_type, *event_data = 0;
1195
1196   while (true)
1197     {
1198       vlib_process_wait_for_event_or_clock (vm,
1199                                             (f64) rm->expire_walk_interval_ms
1200                                             / (f64) MSEC_PER_SEC);
1201       event_type = vlib_process_get_events (vm, &event_data);
1202
1203       switch (event_type)
1204         {
1205         case ~0:                /* no events => timeout */
1206           /* nothing to do here */
1207           break;
1208         case IP4_EVENT_CONFIG_CHANGED:
1209           break;
1210         default:
1211           clib_warning ("BUG: event type 0x%wx", event_type);
1212           break;
1213         }
1214       f64 now = vlib_time_now (vm);
1215
1216       ip4_reass_t *reass;
1217       u32 *vec_drop_timeout = NULL;
1218       int *pool_indexes_to_free = NULL;
1219
1220       uword thread_index = 0;
1221       int index;
1222       const uword nthreads = os_get_nthreads ();
1223       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1224         {
1225           ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1226           clib_spinlock_lock (&rt->lock);
1227
1228           vec_reset_length (pool_indexes_to_free);
1229           /* *INDENT-OFF* */
1230           pool_foreach_index (index, rt->pool, ({
1231                                 reass = pool_elt_at_index (rt->pool, index);
1232                                 if (now > reass->last_heard + rm->timeout)
1233                                   {
1234                                     vec_add1 (pool_indexes_to_free, index);
1235                                   }
1236                               }));
1237           /* *INDENT-ON* */
1238           int *i;
1239           /* *INDENT-OFF* */
1240           vec_foreach (i, pool_indexes_to_free)
1241           {
1242             ip4_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1243             u32 before = vec_len (vec_drop_timeout);
1244             vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
1245             if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1246               {
1247                 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1248                                         b->trace_index))
1249                   {
1250                     /* the trace is gone, don't trace this buffer anymore */
1251                     b->flags &= ~VLIB_BUFFER_IS_TRACED;
1252                   }
1253               }
1254             ip4_reass_on_timeout (vm, rm, reass, &vec_drop_timeout);
1255             u32 after = vec_len (vec_drop_timeout);
1256             ASSERT (rt->buffers_n >= (after - before));
1257             rt->buffers_n -= (after - before);
1258             ip4_reass_free (rm, rt, reass);
1259           }
1260           /* *INDENT-ON* */
1261
1262           clib_spinlock_unlock (&rt->lock);
1263         }
1264
1265       while (vec_len (vec_drop_timeout) > 0)
1266         {
1267           vlib_frame_t *f = vlib_get_frame_to_node (vm, rm->ip4_drop_idx);
1268           u32 *to_next = vlib_frame_vector_args (f);
1269           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1270           int trace_frame = 0;
1271           while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
1272             {
1273               u32 bi = vec_pop (vec_drop_timeout);
1274               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1275               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1276                 {
1277                   if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1278                                           b->trace_index))
1279                     {
1280                       /* the trace is gone, don't trace this buffer anymore */
1281                       b->flags &= ~VLIB_BUFFER_IS_TRACED;
1282                     }
1283                   else
1284                     {
1285                       trace_frame = 1;
1286                     }
1287                 }
1288               b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
1289               to_next[0] = bi;
1290               ++f->n_vectors;
1291               to_next += 1;
1292               n_left_to_next -= 1;
1293               IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout_walk);
1294             }
1295           f->flags |= (trace_frame * VLIB_FRAME_TRACE);
1296           vlib_put_frame_to_node (vm, rm->ip4_drop_idx, f);
1297         }
1298
1299       vec_free (pool_indexes_to_free);
1300       vec_free (vec_drop_timeout);
1301       if (event_data)
1302         {
1303           _vec_len (event_data) = 0;
1304         }
1305     }
1306
1307   return 0;
1308 }
1309
1310 static vlib_node_registration_t ip4_reass_expire_node;
1311
1312 /* *INDENT-OFF* */
1313 VLIB_REGISTER_NODE (ip4_reass_expire_node, static) = {
1314     .function = ip4_reass_walk_expired,
1315     .type = VLIB_NODE_TYPE_PROCESS,
1316     .name = "ip4-reassembly-expire-walk",
1317     .format_trace = format_ip4_reass_trace,
1318     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1319     .error_strings = ip4_reassembly_error_strings,
1320
1321 };
1322 /* *INDENT-ON* */
1323
1324 static u8 *
1325 format_ip4_reass_key (u8 * s, va_list * args)
1326 {
1327   ip4_reass_key_t *key = va_arg (*args, ip4_reass_key_t *);
1328   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1329               key->xx_id, format_ip4_address, &key->src, format_ip4_address,
1330               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1331   return s;
1332 }
1333
1334 static u8 *
1335 format_ip4_reass (u8 * s, va_list * args)
1336 {
1337   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1338   ip4_reass_t *reass = va_arg (*args, ip4_reass_t *);
1339
1340   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1341               "last_packet_octet: %u, trace_op_counter: %u\n",
1342               reass->id, format_ip4_reass_key, &reass->key, reass->first_bi,
1343               reass->data_len, reass->last_packet_octet,
1344               reass->trace_op_counter);
1345   u32 bi = reass->first_bi;
1346   u32 counter = 0;
1347   while (~0 != bi)
1348     {
1349       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1350       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1351       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1352                   "fragment[%u, %u]\n",
1353                   counter, vnb->ip.reass.range_first,
1354                   vnb->ip.reass.range_last, bi,
1355                   ip4_reass_buffer_get_data_offset_no_check (b),
1356                   ip4_reass_buffer_get_data_len_no_check (b),
1357                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1358       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1359         {
1360           bi = b->next_buffer;
1361         }
1362       else
1363         {
1364           bi = ~0;
1365         }
1366     }
1367   return s;
1368 }
1369
1370 static clib_error_t *
1371 show_ip4_reass (vlib_main_t * vm, unformat_input_t * input,
1372                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1373 {
1374   ip4_reass_main_t *rm = &ip4_reass_main;
1375
1376   vlib_cli_output (vm, "---------------------");
1377   vlib_cli_output (vm, "IP4 reassembly status");
1378   vlib_cli_output (vm, "---------------------");
1379   bool details = false;
1380   if (unformat (input, "details"))
1381     {
1382       details = true;
1383     }
1384
1385   u32 sum_reass_n = 0;
1386   u64 sum_buffers_n = 0;
1387   ip4_reass_t *reass;
1388   uword thread_index;
1389   const uword nthreads = os_get_nthreads ();
1390   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1391     {
1392       ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1393       clib_spinlock_lock (&rt->lock);
1394       if (details)
1395         {
1396           /* *INDENT-OFF* */
1397           pool_foreach (reass, rt->pool, {
1398             vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass);
1399           });
1400           /* *INDENT-ON* */
1401         }
1402       sum_reass_n += rt->reass_n;
1403       sum_buffers_n += rt->buffers_n;
1404       clib_spinlock_unlock (&rt->lock);
1405     }
1406   vlib_cli_output (vm, "---------------------");
1407   vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
1408                    (long unsigned) sum_reass_n);
1409   vlib_cli_output (vm,
1410                    "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
1411                    (long unsigned) rm->max_reass_n);
1412   vlib_cli_output (vm, "Buffers in use: %lu\n",
1413                    (long unsigned) sum_buffers_n);
1414   return 0;
1415 }
1416
1417 /* *INDENT-OFF* */
1418 VLIB_CLI_COMMAND (show_ip4_reassembly_cmd, static) = {
1419     .path = "show ip4-reassembly",
1420     .short_help = "show ip4-reassembly [details]",
1421     .function = show_ip4_reass,
1422 };
1423 /* *INDENT-ON* */
1424
1425 vnet_api_error_t
1426 ip4_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1427 {
1428   return vnet_feature_enable_disable ("ip4-unicast", "ip4-reassembly-feature",
1429                                       sw_if_index, enable_disable, 0, 0);
1430 }
1431
1432 /*
1433  * fd.io coding-style-patch-verification: ON
1434  *
1435  * Local Variables:
1436  * eval: (c-set-style "gnu")
1437  * End:
1438  */