src/vnet/ip/ip4_reassembly.c

   1 /*
   2  * Copyright (c) 2017 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 /**
  17  * @file
  18  * @brief IPv4 Reassembly.
  19  *
  20  * This file contains the source code for IPv4 reassembly.
  21  */
  22
  23 #include <vppinfra/vec.h>
  24 #include <vnet/vnet.h>
  25 #include <vnet/ip/ip.h>
  26 #include <vppinfra/bihash_16_8.h>
  27 #include <vnet/ip/ip4_reassembly.h>
  28
  29 #define MSEC_PER_SEC 1000
  30 #define IP4_REASS_TIMEOUT_DEFAULT_MS 100
  31 #define IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000 // 10 seconds default
  32 #define IP4_REASS_MAX_REASSEMBLIES_DEFAULT 1024
  33 #define IP4_REASS_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 typedef enum
  58 {
  59   IP4_REASS_RC_OK,
  60   IP4_REASS_RC_INTERNAL_ERROR,
  61 } ip4_reass_rc_t;
  62
  63 typedef struct
  64 {
  65   union
  66   {
  67     struct
  68     {
  69       u32 xx_id;
  70       ip4_address_t src;
  71       ip4_address_t dst;
  72       u16 frag_id;
  73       u8 proto;
  74       u8 unused;
  75     };
  76     u64 as_u64[2];
  77   };
  78 } ip4_reass_key_t;
  79
  80 always_inline u32
  81 ip4_reass_buffer_get_data_offset (vlib_buffer_t * b)
  82 {
  83   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  84   return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
  85 }
  86
  87 always_inline u16
  88 ip4_reass_buffer_get_data_len (vlib_buffer_t * b)
  89 {
  90   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
  91   return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
  92     (vnb->ip.reass.fragment_first + ip4_reass_buffer_get_data_offset (b)) + 1;
  93 }
  94
  95 typedef struct
  96 {
  97   // hash table key
  98   ip4_reass_key_t key;
  99   // time when last packet was received
 100   f64 last_heard;
 101   // internal id of this reassembly
 102   u64 id;
 103   // buffer index of first buffer in this reassembly context
 104   u32 first_bi;
 105   // last octet of packet, ~0 until fragment without more_fragments arrives
 106   u32 last_packet_octet;
 107   // length of data collected so far
 108   u32 data_len;
 109   // trace operation counter
 110   u32 trace_op_counter;
 111   // next index - used by non-feature node
 112   u8 next_index;
 113   // minimum fragment length for this reassembly - used to estimate MTU
 114   u16 min_fragment_length;
 115 } ip4_reass_t;
 116
 117 typedef struct
 118 {
 119   ip4_reass_t *pool;
 120   u32 reass_n;
 121   u32 buffers_n;
 122   u32 id_counter;
 123   clib_spinlock_t lock;
 124 } ip4_reass_per_thread_t;
 125
 126 typedef struct
 127 {
 128   // IPv4 config
 129   u32 timeout_ms;
 130   f64 timeout;
 131   u32 expire_walk_interval_ms;
 132   u32 max_reass_n;
 133
 134   // IPv4 runtime
 135   clib_bihash_16_8_t hash;
 136   // per-thread data
 137   ip4_reass_per_thread_t *per_thread_data;
 138
 139   // convenience
 140   vlib_main_t *vlib_main;
 141   vnet_main_t *vnet_main;
 142
 143   // node index of ip4-drop node
 144   u32 ip4_drop_idx;
 145   u32 ip4_reass_expire_node_idx;
 146 } ip4_reass_main_t;
 147
 148 ip4_reass_main_t ip4_reass_main;
 149
 150 typedef enum
 151 {
 152   IP4_REASSEMBLY_NEXT_INPUT,
 153   IP4_REASSEMBLY_NEXT_DROP,
 154   IP4_REASSEMBLY_N_NEXT,
 155 } ip4_reass_next_t;
 156
 157 typedef enum
 158 {
 159   RANGE_NEW,
 160   RANGE_SHRINK,
 161   RANGE_DISCARD,
 162   RANGE_OVERLAP,
 163   FINALIZE,
 164 } ip4_reass_trace_operation_e;
 165
 166 typedef struct
 167 {
 168   u16 range_first;
 169   u16 range_last;
 170   u32 range_bi;
 171   i32 data_offset;
 172   u32 data_len;
 173   u32 first_bi;
 174 } ip4_reass_range_trace_t;
 175
 176 typedef struct
 177 {
 178   ip4_reass_trace_operation_e action;
 179   u32 reass_id;
 180   ip4_reass_range_trace_t trace_range;
 181   u32 size_diff;
 182   u32 op_id;
 183   u32 fragment_first;
 184   u32 fragment_last;
 185   u32 total_data_len;
 186 } ip4_reass_trace_t;
 187
 188 static void
 189 ip4_reass_trace_details (vlib_main_t * vm, u32 bi,
 190                          ip4_reass_range_trace_t * trace)
 191 {
 192   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 193   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 194   trace->range_first = vnb->ip.reass.range_first;
 195   trace->range_last = vnb->ip.reass.range_last;
 196   trace->data_offset = ip4_reass_buffer_get_data_offset (b);
 197   trace->data_len = ip4_reass_buffer_get_data_len (b);
 198   trace->range_bi = bi;
 199 }
 200
 201 static u8 *
 202 format_ip4_reass_range_trace (u8 * s, va_list * args)
 203 {
 204   ip4_reass_range_trace_t *trace = va_arg (*args, ip4_reass_range_trace_t *);
 205   s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
 206               trace->range_last, trace->data_offset, trace->data_len,
 207               trace->range_bi);
 208   return s;
 209 }
 210
 211 u8 *
 212 format_ip4_reass_trace (u8 * s, va_list * args)
 213 {
 214   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 215   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 216   ip4_reass_trace_t *t = va_arg (*args, ip4_reass_trace_t *);
 217   s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
 218   u32 indent = format_get_indent (s);
 219   s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
 220               t->trace_range.first_bi, t->total_data_len, t->fragment_first,
 221               t->fragment_last);
 222   switch (t->action)
 223     {
 224     case RANGE_SHRINK:
 225       s = format (s, "\n%Ushrink %U by %u", format_white_space, indent,
 226                   format_ip4_reass_range_trace, &t->trace_range,
 227                   t->size_diff);
 228       break;
 229     case RANGE_DISCARD:
 230       s = format (s, "\n%Udiscard %U", format_white_space, indent,
 231                   format_ip4_reass_range_trace, &t->trace_range);
 232       break;
 233     case RANGE_NEW:
 234       s = format (s, "\n%Unew %U", format_white_space, indent,
 235                   format_ip4_reass_range_trace, &t->trace_range);
 236       break;
 237     case RANGE_OVERLAP:
 238       s = format (s, "\n%Uoverlapping/ignored %U", format_white_space, indent,
 239                   format_ip4_reass_range_trace, &t->trace_range);
 240       break;
 241     case FINALIZE:
 242       s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
 243       break;
 244     }
 245   return s;
 246 }
 247
 248 static void
 249 ip4_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 250                      ip4_reass_main_t * rm, ip4_reass_t * reass, u32 bi,
 251                      ip4_reass_trace_operation_e action, u32 size_diff)
 252 {
 253   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 254   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 255   if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
 256     {
 257       // this buffer's trace is gone
 258       b->flags &= ~VLIB_BUFFER_IS_TRACED;
 259       return;
 260     }
 261   ip4_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 262   t->reass_id = reass->id;
 263   t->action = action;
 264   ip4_reass_trace_details (vm, bi, &t->trace_range);
 265   t->size_diff = size_diff;
 266   t->op_id = reass->trace_op_counter;
 267   ++reass->trace_op_counter;
 268   t->fragment_first = vnb->ip.reass.fragment_first;
 269   t->fragment_last = vnb->ip.reass.fragment_last;
 270   t->trace_range.first_bi = reass->first_bi;
 271   t->total_data_len = reass->data_len;
 272 #if 0
 273   static u8 *s = NULL;
 274   s = format (s, "%U", format_ip4_reass_trace, NULL, NULL, t);
 275   printf ("%.*s\n", vec_len (s), s);
 276   fflush (stdout);
 277   vec_reset_length (s);
 278 #endif
 279 }
 280
 281 always_inline void
 282 ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 283                 ip4_reass_t * reass)
 284 {
 285   clib_bihash_kv_16_8_t kv;
 286   kv.key[0] = reass->key.as_u64[0];
 287   kv.key[1] = reass->key.as_u64[1];
 288   clib_bihash_add_del_16_8 (&rm->hash, &kv, 0);
 289   pool_put (rt->pool, reass);
 290   --rt->reass_n;
 291 }
 292
 293 always_inline void
 294 ip4_reass_on_timeout (vlib_main_t * vm, ip4_reass_main_t * rm,
 295                       ip4_reass_t * reass, u32 ** vec_drop_timeout)
 296 {
 297   u32 range_bi = reass->first_bi;
 298   vlib_buffer_t *range_b;
 299   vnet_buffer_opaque_t *range_vnb;
 300   while (~0 != range_bi)
 301     {
 302       range_b = vlib_get_buffer (vm, range_bi);
 303       range_vnb = vnet_buffer (range_b);
 304       u32 bi = range_bi;
 305       while (~0 != bi)
 306         {
 307           vec_add1 (*vec_drop_timeout, bi);
 308           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 309           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 310             {
 311               bi = b->next_buffer;
 312               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 313             }
 314           else
 315             {
 316               bi = ~0;
 317             }
 318         }
 319       range_bi = range_vnb->ip.reass.next_range_bi;
 320     }
 321 }
 322
 323 ip4_reass_t *
 324 ip4_reass_find_or_create (vlib_main_t * vm, ip4_reass_main_t * rm,
 325                           ip4_reass_per_thread_t * rt,
 326                           ip4_reass_key_t * k, u32 ** vec_drop_timeout)
 327 {
 328   ip4_reass_t *reass = NULL;
 329   f64 now = vlib_time_now (rm->vlib_main);
 330   clib_bihash_kv_16_8_t kv, value;
 331   kv.key[0] = k->as_u64[0];
 332   kv.key[1] = k->as_u64[1];
 333
 334   if (!clib_bihash_search_16_8 (&rm->hash, &kv, &value))
 335     {
 336       reass = pool_elt_at_index (rt->pool, value.value);
 337       if (now > reass->last_heard + rm->timeout)
 338         {
 339           ip4_reass_on_timeout (vm, rm, reass, vec_drop_timeout);
 340           ip4_reass_free (rm, rt, reass);
 341           reass = NULL;
 342         }
 343     }
 344
 345   if (reass)
 346     {
 347       reass->last_heard = now;
 348       return reass;
 349     }
 350
 351   if (rt->reass_n >= rm->max_reass_n)
 352     {
 353       reass = NULL;
 354       return reass;
 355     }
 356   else
 357     {
 358       pool_get (rt->pool, reass);
 359       clib_memset (reass, 0, sizeof (*reass));
 360       reass->id =
 361         ((u64) os_get_thread_index () * 1000000000) + rt->id_counter;
 362       ++rt->id_counter;
 363       reass->first_bi = ~0;
 364       reass->last_packet_octet = ~0;
 365       reass->data_len = 0;
 366       ++rt->reass_n;
 367     }
 368
 369   reass->key.as_u64[0] = kv.key[0] = k->as_u64[0];
 370   reass->key.as_u64[1] = kv.key[1] = k->as_u64[1];
 371   kv.value = reass - rt->pool;
 372   reass->last_heard = now;
 373
 374   if (clib_bihash_add_del_16_8 (&rm->hash, &kv, 1))
 375     {
 376       ip4_reass_free (rm, rt, reass);
 377       reass = NULL;
 378     }
 379
 380   return reass;
 381 }
 382
 383 always_inline ip4_reass_rc_t
 384 ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 385                     ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 386                     ip4_reass_t * reass, u32 * bi0, u32 * next0,
 387                     u32 * error0, u32 ** vec_drop_compress,
 388                     u32 ** vec_drop_overlap, bool is_feature)
 389 {
 390   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 391   vlib_buffer_t *last_b = NULL;
 392   u32 sub_chain_bi = reass->first_bi;
 393   u32 total_length = 0;
 394   u32 buf_cnt = 0;
 395   u32 dropped_cnt = 0;
 396   do
 397     {
 398       u32 tmp_bi = sub_chain_bi;
 399       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 400       ip4_header_t *ip = vlib_buffer_get_current (tmp);
 401       vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
 402       if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 403           !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 404         {
 405           return IP4_REASS_RC_INTERNAL_ERROR;
 406         }
 407
 408       u32 data_len = ip4_reass_buffer_get_data_len (tmp);
 409       u32 trim_front =
 410         ip4_header_bytes (ip) + ip4_reass_buffer_get_data_offset (tmp);
 411       u32 trim_end =
 412         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 413       if (tmp_bi == reass->first_bi)
 414         {
 415           /* first buffer - keep ip4 header */
 416           if (0 != ip4_reass_buffer_get_data_offset (tmp))
 417             {
 418               return IP4_REASS_RC_INTERNAL_ERROR;
 419             }
 420           trim_front = 0;
 421           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 422             ip4_header_bytes (ip);
 423           if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
 424             {
 425               return IP4_REASS_RC_INTERNAL_ERROR;
 426             }
 427         }
 428       u32 keep_data =
 429         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 430       while (1)
 431         {
 432           ++buf_cnt;
 433           if (trim_front)
 434             {
 435               if (trim_front > tmp->current_length)
 436                 {
 437                   /* drop whole buffer */
 438                   vec_add1 (*vec_drop_compress, tmp_bi);
 439                   ++dropped_cnt;
 440                   trim_front -= tmp->current_length;
 441                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 442                     {
 443                       return IP4_REASS_RC_INTERNAL_ERROR;
 444                     }
 445                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 446                   tmp_bi = tmp->next_buffer;
 447                   tmp = vlib_get_buffer (vm, tmp_bi);
 448                   continue;
 449                 }
 450               else
 451                 {
 452                   vlib_buffer_advance (tmp, trim_front);
 453                   trim_front = 0;
 454                 }
 455             }
 456           if (keep_data)
 457             {
 458               if (last_b)
 459                 {
 460                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 461                   last_b->next_buffer = tmp_bi;
 462                 }
 463               last_b = tmp;
 464               if (keep_data <= tmp->current_length)
 465                 {
 466                   tmp->current_length = keep_data;
 467                   keep_data = 0;
 468                 }
 469               else
 470                 {
 471                   keep_data -= tmp->current_length;
 472                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 473                     {
 474                       return IP4_REASS_RC_INTERNAL_ERROR;
 475                     }
 476                 }
 477               total_length += tmp->current_length;
 478             }
 479           else
 480             {
 481               vec_add1 (*vec_drop_overlap, tmp_bi);
 482               if (reass->first_bi == tmp_bi)
 483                 {
 484                   return IP4_REASS_RC_INTERNAL_ERROR;
 485                 }
 486               ++dropped_cnt;
 487             }
 488           if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 489             {
 490               tmp_bi = tmp->next_buffer;
 491               tmp = vlib_get_buffer (vm, tmp->next_buffer);
 492             }
 493           else
 494             {
 495               break;
 496             }
 497         }
 498       sub_chain_bi =
 499         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 500         reass.next_range_bi;
 501     }
 502   while (~0 != sub_chain_bi);
 503
 504   if (!last_b)
 505     {
 506       return IP4_REASS_RC_INTERNAL_ERROR;
 507     }
 508   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 509   rt->buffers_n -= buf_cnt - dropped_cnt;
 510   if (total_length < first_b->current_length)
 511     {
 512       return IP4_REASS_RC_INTERNAL_ERROR;
 513     }
 514   total_length -= first_b->current_length;
 515   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 516   first_b->total_length_not_including_first_buffer = total_length;
 517   ip4_header_t *ip = vlib_buffer_get_current (first_b);
 518   ip->flags_and_fragment_offset = 0;
 519   ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
 520   ip->checksum = ip4_header_checksum (ip);
 521   u32 before = vec_len (*vec_drop_compress);
 522   vlib_buffer_chain_compress (vm, first_b, vec_drop_compress);
 523   rt->buffers_n += vec_len (*vec_drop_compress) - before;
 524
 525   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 526     {
 527       ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
 528 #if 0
 529       // following code does a hexdump of packet fragments to stdout ...
 530       do
 531         {
 532           u32 bi = reass->first_bi;
 533           u8 *s = NULL;
 534           while (~0 != bi)
 535             {
 536               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 537               s = format (s, "%u: %U\n", bi, format_hexdump,
 538                           vlib_buffer_get_current (b), b->current_length);
 539               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 540                 {
 541                   bi = b->next_buffer;
 542                 }
 543               else
 544                 {
 545                   break;
 546                 }
 547             }
 548           printf ("%.*s\n", vec_len (s), s);
 549           fflush (stdout);
 550           vec_free (s);
 551         }
 552       while (0);
 553 #endif
 554     }
 555   *bi0 = reass->first_bi;
 556   if (is_feature)
 557     {
 558       *next0 = IP4_REASSEMBLY_NEXT_INPUT;
 559     }
 560   else
 561     {
 562       *next0 = reass->next_index;
 563     }
 564   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 565   *error0 = IP4_ERROR_NONE;
 566   ip4_reass_free (rm, rt, reass);
 567   reass = NULL;
 568   return IP4_REASS_RC_OK;
 569 }
 570
 571 always_inline u32
 572 ip4_reass_get_buffer_chain_length (vlib_main_t * vm, vlib_buffer_t * b)
 573 {
 574   u32 len = 0;
 575   while (b)
 576     {
 577       ++len;
 578       if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
 579         {
 580           b = vlib_get_buffer (vm, b->next_buffer);
 581         }
 582       else
 583         {
 584           break;
 585         }
 586     }
 587   return len;
 588 }
 589
 590 always_inline ip4_reass_rc_t
 591 ip4_reass_insert_range_in_chain (vlib_main_t * vm,
 592                                  ip4_reass_main_t * rm,
 593                                  ip4_reass_per_thread_t * rt,
 594                                  ip4_reass_t * reass,
 595                                  u32 prev_range_bi, u32 new_next_bi)
 596 {
 597   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 598   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 599   if (~0 != prev_range_bi)
 600     {
 601       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 602       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 603       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 604       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 605     }
 606   else
 607     {
 608       if (~0 != reass->first_bi)
 609         {
 610           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 611         }
 612       reass->first_bi = new_next_bi;
 613     }
 614   vnet_buffer_opaque_t *vnb = vnet_buffer (new_next_b);
 615   if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 616       !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 617     {
 618       return IP4_REASS_RC_INTERNAL_ERROR;
 619     }
 620   reass->data_len += ip4_reass_buffer_get_data_len (new_next_b);
 621   rt->buffers_n += ip4_reass_get_buffer_chain_length (vm, new_next_b);
 622   return IP4_REASS_RC_OK;
 623 }
 624
 625 always_inline ip4_reass_rc_t
 626 ip4_reass_remove_range_from_chain (vlib_main_t * vm,
 627                                    vlib_node_runtime_t * node,
 628                                    ip4_reass_main_t * rm,
 629                                    u32 ** vec_drop_overlap,
 630                                    ip4_reass_t * reass, u32 prev_range_bi,
 631                                    u32 discard_bi)
 632 {
 633   vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi);
 634   vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b);
 635   if (~0 != prev_range_bi)
 636     {
 637       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 638       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 639       if (!(prev_vnb->ip.reass.next_range_bi == discard_bi))
 640         {
 641           return IP4_REASS_RC_INTERNAL_ERROR;
 642         }
 643       prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi;
 644     }
 645   else
 646     {
 647       reass->first_bi = discard_vnb->ip.reass.next_range_bi;
 648     }
 649   vnet_buffer_opaque_t *vnb = vnet_buffer (discard_b);
 650   if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 651       !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 652     {
 653       return IP4_REASS_RC_INTERNAL_ERROR;
 654     }
 655   reass->data_len -= ip4_reass_buffer_get_data_len (discard_b);
 656   while (1)
 657     {
 658       vec_add1 (*vec_drop_overlap, discard_bi);
 659       if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED))
 660         {
 661           ip4_reass_add_trace (vm, node, rm, reass, discard_bi, RANGE_DISCARD,
 662                                0);
 663         }
 664       if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT)
 665         {
 666           discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 667           discard_bi = discard_b->next_buffer;
 668           discard_b = vlib_get_buffer (vm, discard_bi);
 669         }
 670       else
 671         {
 672           break;
 673         }
 674     }
 675   return IP4_REASS_RC_OK;
 676 }
 677
 678 always_inline ip4_reass_rc_t
 679 ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 680                   ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 681                   ip4_reass_t * reass, u32 * bi0, u32 * next0,
 682                   u32 * error0, u32 ** vec_drop_overlap,
 683                   u32 ** vec_drop_compress, bool is_feature)
 684 {
 685   ip4_reass_rc_t rc = IP4_REASS_RC_OK;
 686   int consumed = 0;
 687   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 688   ip4_header_t *fip = vlib_buffer_get_current (fb);
 689   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 690   reass->next_index = fvnb->ip.reass.next_index;        // store next_index before it's overwritten
 691   const u32 fragment_first = ip4_get_fragment_offset_bytes (fip);
 692   const u32 fragment_length =
 693     clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
 694   const u32 fragment_last = fragment_first + fragment_length - 1;
 695   fvnb->ip.reass.fragment_first = fragment_first;
 696   fvnb->ip.reass.fragment_last = fragment_last;
 697   int more_fragments = ip4_get_fragment_more (fip);
 698   u32 candidate_range_bi = reass->first_bi;
 699   u32 prev_range_bi = ~0;
 700   fvnb->ip.reass.range_first = fragment_first;
 701   fvnb->ip.reass.range_last = fragment_last;
 702   fvnb->ip.reass.next_range_bi = ~0;
 703   if (!more_fragments)
 704     {
 705       reass->last_packet_octet = fragment_last;
 706     }
 707   if (~0 == reass->first_bi)
 708     {
 709       // starting a new reassembly
 710       rc =
 711         ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 712                                          *bi0);
 713       if (IP4_REASS_RC_OK != rc)
 714         {
 715           return rc;
 716         }
 717       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 718         {
 719           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 720         }
 721       *bi0 = ~0;
 722       reass->min_fragment_length = clib_net_to_host_u16 (fip->length);
 723       return IP4_REASS_RC_OK;
 724     }
 725   reass->min_fragment_length = clib_min (clib_net_to_host_u16 (fip->length),
 726                                          fvnb->ip.reass.estimated_mtu);
 727   while (~0 != candidate_range_bi)
 728     {
 729       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 730       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 731       if (fragment_first > candidate_vnb->ip.reass.range_last)
 732         {
 733           // this fragments starts after candidate range
 734           prev_range_bi = candidate_range_bi;
 735           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 736           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 737               ~0 == candidate_range_bi)
 738             {
 739               // special case - this fragment falls beyond all known ranges
 740               rc =
 741                 ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 742                                                  prev_range_bi, *bi0);
 743               if (IP4_REASS_RC_OK != rc)
 744                 {
 745                   return rc;
 746                 }
 747               consumed = 1;
 748               break;
 749             }
 750           continue;
 751         }
 752       if (fragment_last < candidate_vnb->ip.reass.range_first)
 753         {
 754           // this fragment ends before candidate range without any overlap
 755           rc =
 756             ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
 757                                              *bi0);
 758           if (IP4_REASS_RC_OK != rc)
 759             {
 760               return rc;
 761             }
 762           consumed = 1;
 763         }
 764       else
 765         {
 766           if (fragment_first >= candidate_vnb->ip.reass.range_first &&
 767               fragment_last <= candidate_vnb->ip.reass.range_last)
 768             {
 769               // this fragment is a (sub)part of existing range, ignore it
 770               if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 771                 {
 772                   ip4_reass_add_trace (vm, node, rm, reass, *bi0,
 773                                        RANGE_OVERLAP, 0);
 774                 }
 775               break;
 776             }
 777           int discard_candidate = 0;
 778           if (fragment_first < candidate_vnb->ip.reass.range_first)
 779             {
 780               u32 overlap =
 781                 fragment_last - candidate_vnb->ip.reass.range_first + 1;
 782               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 783                 {
 784                   candidate_vnb->ip.reass.range_first += overlap;
 785                   if (reass->data_len < overlap)
 786                     {
 787                       return IP4_REASS_RC_INTERNAL_ERROR;
 788                     }
 789                   reass->data_len -= overlap;
 790                   if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 791                     {
 792                       ip4_reass_add_trace (vm, node, rm, reass,
 793                                            candidate_range_bi, RANGE_SHRINK,
 794                                            overlap);
 795                     }
 796                   rc =
 797                     ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 798                                                      prev_range_bi, *bi0);
 799                   if (IP4_REASS_RC_OK != rc)
 800                     {
 801                       return rc;
 802                     }
 803                   consumed = 1;
 804                 }
 805               else
 806                 {
 807                   discard_candidate = 1;
 808                 }
 809             }
 810           else if (fragment_last > candidate_vnb->ip.reass.range_last)
 811             {
 812               u32 overlap =
 813                 candidate_vnb->ip.reass.range_last - fragment_first + 1;
 814               if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
 815                 {
 816                   fvnb->ip.reass.range_first += overlap;
 817                   if (~0 != candidate_vnb->ip.reass.next_range_bi)
 818                     {
 819                       prev_range_bi = candidate_range_bi;
 820                       candidate_range_bi =
 821                         candidate_vnb->ip.reass.next_range_bi;
 822                       continue;
 823                     }
 824                   else
 825                     {
 826                       // special case - last range discarded
 827                       rc =
 828                         ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 829                                                          candidate_range_bi,
 830                                                          *bi0);
 831                       if (IP4_REASS_RC_OK != rc)
 832                         {
 833                           return rc;
 834                         }
 835                       consumed = 1;
 836                     }
 837                 }
 838               else
 839                 {
 840                   discard_candidate = 1;
 841                 }
 842             }
 843           else
 844             {
 845               discard_candidate = 1;
 846             }
 847           if (discard_candidate)
 848             {
 849               u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi;
 850               // discard candidate range, probe next range
 851               rc =
 852                 ip4_reass_remove_range_from_chain (vm, node, rm,
 853                                                    vec_drop_overlap, reass,
 854                                                    prev_range_bi,
 855                                                    candidate_range_bi);
 856               if (IP4_REASS_RC_OK != rc)
 857                 {
 858                   return rc;
 859                 }
 860               if (~0 != next_range_bi)
 861                 {
 862                   candidate_range_bi = next_range_bi;
 863                   continue;
 864                 }
 865               else
 866                 {
 867                   // special case - last range discarded
 868                   rc =
 869                     ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
 870                                                      prev_range_bi, *bi0);
 871                   if (IP4_REASS_RC_OK != rc)
 872                     {
 873                       return rc;
 874                     }
 875                   consumed = 1;
 876                 }
 877             }
 878         }
 879       break;
 880     }
 881   if (consumed)
 882     {
 883       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 884         {
 885           ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
 886         }
 887     }
 888   if (~0 != reass->last_packet_octet &&
 889       reass->data_len == reass->last_packet_octet + 1)
 890     {
 891       return ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
 892                                  vec_drop_compress, vec_drop_overlap,
 893                                  is_feature);
 894     }
 895   else
 896     {
 897       if (consumed)
 898         {
 899           *bi0 = ~0;
 900         }
 901       else
 902         {
 903           *next0 = IP4_REASSEMBLY_NEXT_DROP;
 904           *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT;
 905         }
 906     }
 907   return rc;
 908 }
 909
 910 always_inline uword
 911 ip4_reassembly_inline (vlib_main_t * vm,
 912                        vlib_node_runtime_t * node,
 913                        vlib_frame_t * frame, bool is_feature)
 914 {
 915   u32 *from = vlib_frame_vector_args (frame);
 916   u32 n_left_from, n_left_to_next, *to_next, next_index;
 917   ip4_reass_main_t *rm = &ip4_reass_main;
 918   ip4_reass_per_thread_t *rt = &rm->per_thread_data[os_get_thread_index ()];
 919   clib_spinlock_lock (&rt->lock);
 920
 921   n_left_from = frame->n_vectors;
 922   next_index = node->cached_next_index;
 923   static u32 *vec_drop_timeout = NULL;  // indexes of buffers which timed out
 924   static u32 *vec_drop_overlap = NULL;  // indexes of buffers which were discarded due to overlap
 925   static u32 *vec_drop_internal_error = NULL;   // indexes of buffers which were discarded due to internal errors
 926   static u32 *vec_drop_compress = NULL; // indexes of buffers dicarded due to buffer compression
 927   while (n_left_from > 0 || vec_len (vec_drop_timeout) > 0
 928          || vec_len (vec_drop_overlap) > 0 || vec_len (vec_drop_compress) > 0
 929          || vec_len (vec_drop_internal_error) > 0)
 930     {
 931       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 932
 933       while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
 934         {
 935           u32 bi = vec_pop (vec_drop_timeout);
 936           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 937           b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
 938           to_next[0] = bi;
 939           to_next += 1;
 940           n_left_to_next -= 1;
 941           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 942                                            n_left_to_next, bi,
 943                                            IP4_REASSEMBLY_NEXT_DROP);
 944           IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout);
 945           --rt->buffers_n;
 946         }
 947
 948       while (vec_len (vec_drop_overlap) > 0 && n_left_to_next > 0)
 949         {
 950           u32 bi = vec_pop (vec_drop_overlap);
 951           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 952           b->error = node->errors[IP4_ERROR_REASS_DUPLICATE_FRAGMENT];
 953           to_next[0] = bi;
 954           to_next += 1;
 955           n_left_to_next -= 1;
 956           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 957                                            n_left_to_next, bi,
 958                                            IP4_REASSEMBLY_NEXT_DROP);
 959           IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_duplicate_fragment);
 960           --rt->buffers_n;
 961         }
 962
 963       while (vec_len (vec_drop_compress) > 0 && n_left_to_next > 0)
 964         {
 965           u32 bi = vec_pop (vec_drop_compress);
 966           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 967           b->error = node->errors[IP4_ERROR_NONE];
 968           to_next[0] = bi;
 969           to_next += 1;
 970           n_left_to_next -= 1;
 971           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 972                                            n_left_to_next, bi,
 973                                            IP4_REASSEMBLY_NEXT_DROP);
 974           IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_compress);
 975           --rt->buffers_n;
 976         }
 977       while (vec_len (vec_drop_internal_error) > 0 && n_left_to_next > 0)
 978         {
 979           u32 bi = vec_pop (vec_drop_internal_error);
 980           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 981           b->error = node->errors[IP4_ERROR_REASS_INTERNAL_ERROR];
 982           to_next[0] = bi;
 983           to_next += 1;
 984           n_left_to_next -= 1;
 985           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 986                                            n_left_to_next, bi,
 987                                            IP4_REASSEMBLY_NEXT_DROP);
 988           IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_internal_error);
 989           --rt->buffers_n;
 990         }
 991       while (n_left_from > 0 && n_left_to_next > 0)
 992         {
 993           u32 bi0;
 994           vlib_buffer_t *b0;
 995           u32 next0;
 996           u32 error0 = IP4_ERROR_NONE;
 997
 998           bi0 = from[0];
 999           b0 = vlib_get_buffer (vm, bi0);
1000
1001           ip4_header_t *ip0 = vlib_buffer_get_current (b0);
1002           if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
1003             {
1004               // this is a whole packet - no fragmentation
1005               if (is_feature)
1006                 {
1007                   next0 = IP4_REASSEMBLY_NEXT_INPUT;
1008                 }
1009               else
1010                 {
1011                   next0 = vnet_buffer (b0)->ip.reass.next_index;
1012                 }
1013             }
1014           else
1015             {
1016               const u32 fragment_first = ip4_get_fragment_offset_bytes (ip0);
1017               const u32 fragment_length =
1018                 clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0);
1019               const u32 fragment_last = fragment_first + fragment_length - 1;
1020               if (fragment_first > fragment_last || fragment_first + fragment_length > UINT16_MAX - 20 || (fragment_length < 8 && ip4_get_fragment_more (ip0))) // 8 is minimum frag length per RFC 791
1021                 {
1022                   next0 = IP4_REASSEMBLY_NEXT_DROP;
1023                   error0 = IP4_ERROR_REASS_MALFORMED_PACKET;
1024                 }
1025               else
1026                 {
1027                   ip4_reass_key_t k;
1028                   k.as_u64[0] =
1029                     (u64) vnet_buffer (b0)->sw_if_index[VLIB_RX] |
1030                     (u64) ip0->src_address.as_u32 << 32;
1031                   k.as_u64[1] =
1032                     (u64) ip0->dst_address.as_u32 |
1033                     (u64) ip0->fragment_id << 32 | (u64) ip0->protocol << 48;
1034
1035                   ip4_reass_t *reass =
1036                     ip4_reass_find_or_create (vm, rm, rt, &k,
1037                                               &vec_drop_timeout);
1038
1039                   if (reass)
1040                     {
1041                       switch (ip4_reass_update
1042                               (vm, node, rm, rt, reass, &bi0, &next0, &error0,
1043                                &vec_drop_overlap, &vec_drop_compress,
1044                                is_feature))
1045                         {
1046                         case IP4_REASS_RC_OK:
1047                           /* nothing to do here */
1048                           break;
1049                         case IP4_REASS_RC_INTERNAL_ERROR:
1050                           /* drop everything and start with a clean slate */
1051                           ip4_reass_on_timeout (vm, rm, reass,
1052                                                 &vec_drop_internal_error);
1053                           ip4_reass_free (rm, rt, reass);
1054                           goto next_packet;
1055                           break;
1056                         }
1057                     }
1058                   else
1059                     {
1060                       next0 = IP4_REASSEMBLY_NEXT_DROP;
1061                       error0 = IP4_ERROR_REASS_LIMIT_REACHED;
1062                     }
1063                 }
1064
1065               b0->error = node->errors[error0];
1066             }
1067
1068           if (bi0 != ~0)
1069             {
1070               to_next[0] = bi0;
1071               to_next += 1;
1072               n_left_to_next -= 1;
1073               if (is_feature && IP4_ERROR_NONE == error0)
1074                 {
1075                   b0 = vlib_get_buffer (vm, bi0);
1076                   vnet_feature_next (&next0, b0);
1077                 }
1078               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1079                                                n_left_to_next, bi0, next0);
1080               IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next);
1081             }
1082
1083         next_packet:
1084           from += 1;
1085           n_left_from -= 1;
1086         }
1087
1088       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1089     }
1090
1091   clib_spinlock_unlock (&rt->lock);
1092   return frame->n_vectors;
1093 }
1094
1095 static char *ip4_reassembly_error_strings[] = {
1096 #define _(sym, string) string,
1097   foreach_ip4_error
1098 #undef _
1099 };
1100
1101 static uword
1102 ip4_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
1103                 vlib_frame_t * frame)
1104 {
1105   return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ );
1106 }
1107
1108 /* *INDENT-OFF* */
1109 VLIB_REGISTER_NODE (ip4_reass_node, static) = {
1110     .function = ip4_reassembly,
1111     .name = "ip4-reassembly",
1112     .vector_size = sizeof (u32),
1113     .format_trace = format_ip4_reass_trace,
1114     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1115     .error_strings = ip4_reassembly_error_strings,
1116     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1117     .next_nodes =
1118         {
1119                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1120                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1121         },
1122 };
1123 /* *INDENT-ON* */
1124
1125 VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node, ip4_reassembly);
1126
1127 static uword
1128 ip4_reassembly_feature (vlib_main_t * vm,
1129                         vlib_node_runtime_t * node, vlib_frame_t * frame)
1130 {
1131   return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ );
1132 }
1133
1134 /* *INDENT-OFF* */
1135 VLIB_REGISTER_NODE (ip4_reass_node_feature, static) = {
1136     .function = ip4_reassembly_feature,
1137     .name = "ip4-reassembly-feature",
1138     .vector_size = sizeof (u32),
1139     .format_trace = format_ip4_reass_trace,
1140     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1141     .error_strings = ip4_reassembly_error_strings,
1142     .n_next_nodes = IP4_REASSEMBLY_N_NEXT,
1143     .next_nodes =
1144         {
1145                 [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
1146                 [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
1147         },
1148 };
1149 /* *INDENT-ON* */
1150
1151 VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node_feature, ip4_reassembly_feature);
1152
1153 /* *INDENT-OFF* */
1154 VNET_FEATURE_INIT (ip4_reassembly_feature, static) = {
1155     .arc_name = "ip4-unicast",
1156     .node_name = "ip4-reassembly-feature",
1157     .runs_before = VNET_FEATURES ("ip4-lookup"),
1158     .runs_after = 0,
1159 };
1160 /* *INDENT-ON* */
1161
1162 always_inline u32
1163 ip4_reass_get_nbuckets ()
1164 {
1165   ip4_reass_main_t *rm = &ip4_reass_main;
1166   u32 nbuckets;
1167   u8 i;
1168
1169   nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR);
1170
1171   for (i = 0; i < 31; i++)
1172     if ((1 << i) >= nbuckets)
1173       break;
1174   nbuckets = 1 << i;
1175
1176   return nbuckets;
1177 }
1178
1179 typedef enum
1180 {
1181   IP4_EVENT_CONFIG_CHANGED = 1,
1182 } ip4_reass_event_t;
1183
1184 typedef struct
1185 {
1186   int failure;
1187   clib_bihash_16_8_t *new_hash;
1188 } ip4_rehash_cb_ctx;
1189
1190 static void
1191 ip4_rehash_cb (clib_bihash_kv_16_8_t * kv, void *_ctx)
1192 {
1193   ip4_rehash_cb_ctx *ctx = _ctx;
1194   if (clib_bihash_add_del_16_8 (ctx->new_hash, kv, 1))
1195     {
1196       ctx->failure = 1;
1197     }
1198 }
1199
1200 static void
1201 ip4_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1202                       u32 expire_walk_interval_ms)
1203 {
1204   ip4_reass_main.timeout_ms = timeout_ms;
1205   ip4_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1206   ip4_reass_main.max_reass_n = max_reassemblies;
1207   ip4_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1208 }
1209
1210 vnet_api_error_t
1211 ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
1212                u32 expire_walk_interval_ms)
1213 {
1214   u32 old_nbuckets = ip4_reass_get_nbuckets ();
1215   ip4_reass_set_params (timeout_ms, max_reassemblies,
1216                         expire_walk_interval_ms);
1217   vlib_process_signal_event (ip4_reass_main.vlib_main,
1218                              ip4_reass_main.ip4_reass_expire_node_idx,
1219                              IP4_EVENT_CONFIG_CHANGED, 0);
1220   u32 new_nbuckets = ip4_reass_get_nbuckets ();
1221   if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1222     {
1223       clib_bihash_16_8_t new_hash;
1224       clib_memset (&new_hash, 0, sizeof (new_hash));
1225       ip4_rehash_cb_ctx ctx;
1226       ctx.failure = 0;
1227       ctx.new_hash = &new_hash;
1228       clib_bihash_init_16_8 (&new_hash, "ip4-reass", new_nbuckets,
1229                              new_nbuckets * 1024);
1230       clib_bihash_foreach_key_value_pair_16_8 (&ip4_reass_main.hash,
1231                                                ip4_rehash_cb, &ctx);
1232       if (ctx.failure)
1233         {
1234           clib_bihash_free_16_8 (&new_hash);
1235           return -1;
1236         }
1237       else
1238         {
1239           clib_bihash_free_16_8 (&ip4_reass_main.hash);
1240           clib_memcpy_fast (&ip4_reass_main.hash, &new_hash,
1241                             sizeof (ip4_reass_main.hash));
1242         }
1243     }
1244   return 0;
1245 }
1246
1247 vnet_api_error_t
1248 ip4_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1249                u32 * expire_walk_interval_ms)
1250 {
1251   *timeout_ms = ip4_reass_main.timeout_ms;
1252   *max_reassemblies = ip4_reass_main.max_reass_n;
1253   *expire_walk_interval_ms = ip4_reass_main.expire_walk_interval_ms;
1254   return 0;
1255 }
1256
1257 static clib_error_t *
1258 ip4_reass_init_function (vlib_main_t * vm)
1259 {
1260   ip4_reass_main_t *rm = &ip4_reass_main;
1261   clib_error_t *error = 0;
1262   u32 nbuckets;
1263   vlib_node_t *node;
1264
1265   rm->vlib_main = vm;
1266   rm->vnet_main = vnet_get_main ();
1267
1268   vec_validate (rm->per_thread_data, vlib_num_workers ());
1269   ip4_reass_per_thread_t *rt;
1270   vec_foreach (rt, rm->per_thread_data)
1271   {
1272     clib_spinlock_init (&rt->lock);
1273     pool_alloc (rt->pool, rm->max_reass_n);
1274   }
1275
1276   node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk");
1277   ASSERT (node);
1278   rm->ip4_reass_expire_node_idx = node->index;
1279
1280   ip4_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS,
1281                         IP4_REASS_MAX_REASSEMBLIES_DEFAULT,
1282                         IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1283
1284   nbuckets = ip4_reass_get_nbuckets ();
1285   clib_bihash_init_16_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024);
1286
1287   node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
1288   ASSERT (node);
1289   rm->ip4_drop_idx = node->index;
1290
1291   return error;
1292 }
1293
1294 VLIB_INIT_FUNCTION (ip4_reass_init_function);
1295
1296 static uword
1297 ip4_reass_walk_expired (vlib_main_t * vm,
1298                         vlib_node_runtime_t * node, vlib_frame_t * f)
1299 {
1300   ip4_reass_main_t *rm = &ip4_reass_main;
1301   uword event_type, *event_data = 0;
1302
1303   while (true)
1304     {
1305       vlib_process_wait_for_event_or_clock (vm,
1306                                             (f64) rm->expire_walk_interval_ms
1307                                             / (f64) MSEC_PER_SEC);
1308       event_type = vlib_process_get_events (vm, &event_data);
1309
1310       switch (event_type)
1311         {
1312         case ~0:                /* no events => timeout */
1313           /* nothing to do here */
1314           break;
1315         case IP4_EVENT_CONFIG_CHANGED:
1316           break;
1317         default:
1318           clib_warning ("BUG: event type 0x%wx", event_type);
1319           break;
1320         }
1321       f64 now = vlib_time_now (vm);
1322
1323       ip4_reass_t *reass;
1324       u32 *vec_drop_timeout = NULL;
1325       int *pool_indexes_to_free = NULL;
1326
1327       uword thread_index = 0;
1328       int index;
1329       const uword nthreads = vlib_num_workers () + 1;
1330       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1331         {
1332           ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1333           clib_spinlock_lock (&rt->lock);
1334
1335           vec_reset_length (pool_indexes_to_free);
1336           /* *INDENT-OFF* */
1337           pool_foreach_index (index, rt->pool, ({
1338                                 reass = pool_elt_at_index (rt->pool, index);
1339                                 if (now > reass->last_heard + rm->timeout)
1340                                   {
1341                                     vec_add1 (pool_indexes_to_free, index);
1342                                   }
1343                               }));
1344           /* *INDENT-ON* */
1345           int *i;
1346           /* *INDENT-OFF* */
1347           vec_foreach (i, pool_indexes_to_free)
1348           {
1349             ip4_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1350             u32 before = vec_len (vec_drop_timeout);
1351             vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
1352             if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1353               {
1354                 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1355                                         b->trace_index))
1356                   {
1357                     /* the trace is gone, don't trace this buffer anymore */
1358                     b->flags &= ~VLIB_BUFFER_IS_TRACED;
1359                   }
1360               }
1361             ip4_reass_on_timeout (vm, rm, reass, &vec_drop_timeout);
1362             u32 after = vec_len (vec_drop_timeout);
1363             rt->buffers_n -= (after - before);
1364             ip4_reass_free (rm, rt, reass);
1365           }
1366           /* *INDENT-ON* */
1367
1368           clib_spinlock_unlock (&rt->lock);
1369         }
1370
1371       while (vec_len (vec_drop_timeout) > 0)
1372         {
1373           vlib_frame_t *f = vlib_get_frame_to_node (vm, rm->ip4_drop_idx);
1374           u32 *to_next = vlib_frame_vector_args (f);
1375           u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
1376           int trace_frame = 0;
1377           while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
1378             {
1379               u32 bi = vec_pop (vec_drop_timeout);
1380               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1381               if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
1382                 {
1383                   if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
1384                                           b->trace_index))
1385                     {
1386                       /* the trace is gone, don't trace this buffer anymore */
1387                       b->flags &= ~VLIB_BUFFER_IS_TRACED;
1388                     }
1389                   else
1390                     {
1391                       trace_frame = 1;
1392                     }
1393                 }
1394               b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
1395               to_next[0] = bi;
1396               ++f->n_vectors;
1397               to_next += 1;
1398               n_left_to_next -= 1;
1399               IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout_walk);
1400             }
1401           f->frame_flags |= (trace_frame * VLIB_FRAME_TRACE);
1402           vlib_put_frame_to_node (vm, rm->ip4_drop_idx, f);
1403         }
1404
1405       vec_free (pool_indexes_to_free);
1406       vec_free (vec_drop_timeout);
1407       if (event_data)
1408         {
1409           _vec_len (event_data) = 0;
1410         }
1411     }
1412
1413   return 0;
1414 }
1415
1416 static vlib_node_registration_t ip4_reass_expire_node;
1417
1418 /* *INDENT-OFF* */
1419 VLIB_REGISTER_NODE (ip4_reass_expire_node, static) = {
1420     .function = ip4_reass_walk_expired,
1421     .type = VLIB_NODE_TYPE_PROCESS,
1422     .name = "ip4-reassembly-expire-walk",
1423     .format_trace = format_ip4_reass_trace,
1424     .n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
1425     .error_strings = ip4_reassembly_error_strings,
1426
1427 };
1428 /* *INDENT-ON* */
1429
1430 static u8 *
1431 format_ip4_reass_key (u8 * s, va_list * args)
1432 {
1433   ip4_reass_key_t *key = va_arg (*args, ip4_reass_key_t *);
1434   s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1435               key->xx_id, format_ip4_address, &key->src, format_ip4_address,
1436               &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1437   return s;
1438 }
1439
1440 static u8 *
1441 format_ip4_reass (u8 * s, va_list * args)
1442 {
1443   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1444   ip4_reass_t *reass = va_arg (*args, ip4_reass_t *);
1445
1446   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1447               "last_packet_octet: %u, trace_op_counter: %u\n",
1448               reass->id, format_ip4_reass_key, &reass->key, reass->first_bi,
1449               reass->data_len, reass->last_packet_octet,
1450               reass->trace_op_counter);
1451   u32 bi = reass->first_bi;
1452   u32 counter = 0;
1453   while (~0 != bi)
1454     {
1455       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1456       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1457       s = format (s, "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1458                   "fragment[%u, %u]\n",
1459                   counter, vnb->ip.reass.range_first,
1460                   vnb->ip.reass.range_last, bi,
1461                   ip4_reass_buffer_get_data_offset (b),
1462                   ip4_reass_buffer_get_data_len (b),
1463                   vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1464       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1465         {
1466           bi = b->next_buffer;
1467         }
1468       else
1469         {
1470           bi = ~0;
1471         }
1472     }
1473   return s;
1474 }
1475
1476 static clib_error_t *
1477 show_ip4_reass (vlib_main_t * vm, unformat_input_t * input,
1478                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1479 {
1480   ip4_reass_main_t *rm = &ip4_reass_main;
1481
1482   vlib_cli_output (vm, "---------------------");
1483   vlib_cli_output (vm, "IP4 reassembly status");
1484   vlib_cli_output (vm, "---------------------");
1485   bool details = false;
1486   if (unformat (input, "details"))
1487     {
1488       details = true;
1489     }
1490
1491   u32 sum_reass_n = 0;
1492   u64 sum_buffers_n = 0;
1493   ip4_reass_t *reass;
1494   uword thread_index;
1495   const uword nthreads = vlib_num_workers () + 1;
1496   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1497     {
1498       ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1499       clib_spinlock_lock (&rt->lock);
1500       if (details)
1501         {
1502           /* *INDENT-OFF* */
1503           pool_foreach (reass, rt->pool, {
1504             vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass);
1505           });
1506           /* *INDENT-ON* */
1507         }
1508       sum_reass_n += rt->reass_n;
1509       sum_buffers_n += rt->buffers_n;
1510       clib_spinlock_unlock (&rt->lock);
1511     }
1512   vlib_cli_output (vm, "---------------------");
1513   vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
1514                    (long unsigned) sum_reass_n);
1515   vlib_cli_output (vm,
1516                    "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
1517                    (long unsigned) rm->max_reass_n);
1518   vlib_cli_output (vm, "Buffers in use: %lu\n",
1519                    (long unsigned) sum_buffers_n);
1520   return 0;
1521 }
1522
1523 /* *INDENT-OFF* */
1524 VLIB_CLI_COMMAND (show_ip4_reassembly_cmd, static) = {
1525     .path = "show ip4-reassembly",
1526     .short_help = "show ip4-reassembly [details]",
1527     .function = show_ip4_reass,
1528 };
1529 /* *INDENT-ON* */
1530
1531 vnet_api_error_t
1532 ip4_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1533 {
1534   return vnet_feature_enable_disable ("ip4-unicast", "ip4-reassembly-feature",
1535                                       sw_if_index, enable_disable, 0, 0);
1536 }
1537
1538 /*
1539  * fd.io coding-style-patch-verification: ON
1540  *
1541  * Local Variables:
1542  * eval: (c-set-style "gnu")
1543  * End:
1544  */