src/vnet/ip/reass/ip4_full_reass.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 Full Reassembly.
  19  *
  20  * This file contains the source code for IPv4 full reassembly.
  21  */
  22
  23 #include <vppinfra/vec.h>
  24 #include <vnet/vnet.h>
  25 #include <vnet/ip/ip.h>
  26 #include <vppinfra/fifo.h>
  27 #include <vppinfra/bihash_16_8.h>
  28 #include <vnet/ip/reass/ip4_full_reass.h>
  29 #include <stddef.h>
  30
  31 #define MSEC_PER_SEC 1000
  32 #define IP4_REASS_TIMEOUT_DEFAULT_MS 100
  33 #define IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000 // 10 seconds default
  34 #define IP4_REASS_MAX_REASSEMBLIES_DEFAULT 1024
  35 #define IP4_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT 3
  36 #define IP4_REASS_HT_LOAD_FACTOR (0.75)
  37
  38 #define IP4_REASS_DEBUG_BUFFERS 0
  39 #if IP4_REASS_DEBUG_BUFFERS
  40 #define IP4_REASS_DEBUG_BUFFER(bi, what)             \
  41   do                                                 \
  42     {                                                \
  43       u32 _bi = bi;                                  \
  44       printf (#what "buffer %u", _bi);               \
  45       vlib_buffer_t *_b = vlib_get_buffer (vm, _bi); \
  46       while (_b->flags & VLIB_BUFFER_NEXT_PRESENT)   \
  47         {                                            \
  48           _bi = _b->next_buffer;                     \
  49           printf ("[%u]", _bi);                      \
  50           _b = vlib_get_buffer (vm, _bi);            \
  51         }                                            \
  52       printf ("\n");                                 \
  53       fflush (stdout);                               \
  54     }                                                \
  55   while (0)
  56 #else
  57 #define IP4_REASS_DEBUG_BUFFER(...)
  58 #endif
  59
  60 typedef enum
  61 {
  62   IP4_REASS_RC_OK,
  63   IP4_REASS_RC_TOO_MANY_FRAGMENTS,
  64   IP4_REASS_RC_INTERNAL_ERROR,
  65   IP4_REASS_RC_NO_BUF,
  66   IP4_REASS_RC_HANDOFF,
  67 } ip4_full_reass_rc_t;
  68
  69 typedef struct
  70 {
  71   union
  72   {
  73     struct
  74     {
  75       u32 xx_id;
  76       ip4_address_t src;
  77       ip4_address_t dst;
  78       u16 frag_id;
  79       u8 proto;
  80       u8 unused;
  81     };
  82     u64 as_u64[2];
  83   };
  84 } ip4_full_reass_key_t;
  85
  86 typedef union
  87 {
  88   struct
  89   {
  90     u32 reass_index;
  91     u32 memory_owner_thread_index;
  92   };
  93   u64 as_u64;
  94 } ip4_full_reass_val_t;
  95
  96 typedef union
  97 {
  98   struct
  99   {
 100     ip4_full_reass_key_t k;
 101     ip4_full_reass_val_t v;
 102   };
 103   clib_bihash_kv_16_8_t kv;
 104 } ip4_full_reass_kv_t;
 105
 106 always_inline u32
 107 ip4_full_reass_buffer_get_data_offset (vlib_buffer_t * b)
 108 {
 109   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 110   return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
 111 }
 112
 113 always_inline u16
 114 ip4_full_reass_buffer_get_data_len (vlib_buffer_t * b)
 115 {
 116   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 117   return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
 118     (vnb->ip.reass.fragment_first +
 119      ip4_full_reass_buffer_get_data_offset (b)) + 1;
 120 }
 121
 122 typedef struct
 123 {
 124   // hash table key
 125   ip4_full_reass_key_t key;
 126   // time when last packet was received
 127   f64 last_heard;
 128   // internal id of this reassembly
 129   u64 id;
 130   // buffer index of first buffer in this reassembly context
 131   u32 first_bi;
 132   // last octet of packet, ~0 until fragment without more_fragments arrives
 133   u32 last_packet_octet;
 134   // length of data collected so far
 135   u32 data_len;
 136   // trace operation counter
 137   u32 trace_op_counter;
 138   // next index - used by non-feature node
 139   u32 next_index;
 140   // error next index - used by custom apps (~0 if not used)
 141   u32 error_next_index;
 142   // minimum fragment length for this reassembly - used to estimate MTU
 143   u16 min_fragment_length;
 144   // number of fragments in this reassembly
 145   u32 fragments_n;
 146   // thread owning memory for this context (whose pool contains this ctx)
 147   u32 memory_owner_thread_index;
 148   // thread which received fragment with offset 0 and which sends out the
 149   // completed reassembly
 150   u32 sendout_thread_index;
 151 } ip4_full_reass_t;
 152
 153 typedef struct
 154 {
 155   ip4_full_reass_t *pool;
 156   u32 reass_n;
 157   u32 id_counter;
 158   clib_spinlock_t lock;
 159 } ip4_full_reass_per_thread_t;
 160
 161 typedef struct
 162 {
 163   // IPv4 config
 164   u32 timeout_ms;
 165   f64 timeout;
 166   u32 expire_walk_interval_ms;
 167   // maximum number of fragments in one reassembly
 168   u32 max_reass_len;
 169   // maximum number of reassemblies
 170   u32 max_reass_n;
 171
 172   // IPv4 runtime
 173   clib_bihash_16_8_t hash;
 174   // per-thread data
 175   ip4_full_reass_per_thread_t *per_thread_data;
 176
 177   // convenience
 178   vlib_main_t *vlib_main;
 179
 180   // node index of ip4-drop node
 181   u32 ip4_drop_idx;
 182   u32 ip4_full_reass_expire_node_idx;
 183
 184   /** Worker handoff */
 185   u32 fq_index;
 186   u32 fq_feature_index;
 187
 188   // reference count for enabling/disabling feature - per interface
 189   u32 *feature_use_refcount_per_intf;
 190 } ip4_full_reass_main_t;
 191
 192 extern ip4_full_reass_main_t ip4_full_reass_main;
 193
 194 #ifndef CLIB_MARCH_VARIANT
 195 ip4_full_reass_main_t ip4_full_reass_main;
 196 #endif /* CLIB_MARCH_VARIANT */
 197
 198 typedef enum
 199 {
 200   IP4_FULL_REASS_NEXT_INPUT,
 201   IP4_FULL_REASS_NEXT_DROP,
 202   IP4_FULL_REASS_NEXT_HANDOFF,
 203   IP4_FULL_REASS_N_NEXT,
 204 } ip4_full_reass_next_t;
 205
 206 typedef enum
 207 {
 208   RANGE_NEW,
 209   RANGE_SHRINK,
 210   RANGE_DISCARD,
 211   RANGE_OVERLAP,
 212   FINALIZE,
 213   HANDOFF,
 214 } ip4_full_reass_trace_operation_e;
 215
 216 typedef struct
 217 {
 218   u16 range_first;
 219   u16 range_last;
 220   u32 range_bi;
 221   i32 data_offset;
 222   u32 data_len;
 223   u32 first_bi;
 224 } ip4_full_reass_range_trace_t;
 225
 226 typedef struct
 227 {
 228   ip4_full_reass_trace_operation_e action;
 229   u32 reass_id;
 230   ip4_full_reass_range_trace_t trace_range;
 231   u32 size_diff;
 232   u32 op_id;
 233   u32 thread_id;
 234   u32 thread_id_to;
 235   u32 fragment_first;
 236   u32 fragment_last;
 237   u32 total_data_len;
 238 } ip4_full_reass_trace_t;
 239
 240 extern vlib_node_registration_t ip4_full_reass_node;
 241 extern vlib_node_registration_t ip4_full_reass_node_feature;
 242
 243 static void
 244 ip4_full_reass_trace_details (vlib_main_t * vm, u32 bi,
 245                               ip4_full_reass_range_trace_t * trace)
 246 {
 247   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 248   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 249   trace->range_first = vnb->ip.reass.range_first;
 250   trace->range_last = vnb->ip.reass.range_last;
 251   trace->data_offset = ip4_full_reass_buffer_get_data_offset (b);
 252   trace->data_len = ip4_full_reass_buffer_get_data_len (b);
 253   trace->range_bi = bi;
 254 }
 255
 256 static u8 *
 257 format_ip4_full_reass_range_trace (u8 * s, va_list * args)
 258 {
 259   ip4_full_reass_range_trace_t *trace =
 260     va_arg (*args, ip4_full_reass_range_trace_t *);
 261   s =
 262     format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
 263             trace->range_last, trace->data_offset, trace->data_len,
 264             trace->range_bi);
 265   return s;
 266 }
 267
 268 static u8 *
 269 format_ip4_full_reass_trace (u8 * s, va_list * args)
 270 {
 271   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 272   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 273   ip4_full_reass_trace_t *t = va_arg (*args, ip4_full_reass_trace_t *);
 274   u32 indent = 0;
 275   if (~0 != t->reass_id)
 276     {
 277       s = format (s, "reass id: %u, op id: %u, ", t->reass_id, t->op_id);
 278       indent = format_get_indent (s);
 279       s =
 280         format (s,
 281                 "first bi: %u, data len: %u, ip/fragment[%u, %u]",
 282                 t->trace_range.first_bi, t->total_data_len, t->fragment_first,
 283                 t->fragment_last);
 284     }
 285   switch (t->action)
 286     {
 287     case RANGE_SHRINK:
 288       s = format (s, "\n%Ushrink %U by %u", format_white_space, indent,
 289                   format_ip4_full_reass_range_trace, &t->trace_range,
 290                   t->size_diff);
 291       break;
 292     case RANGE_DISCARD:
 293       s = format (s, "\n%Udiscard %U", format_white_space, indent,
 294                   format_ip4_full_reass_range_trace, &t->trace_range);
 295       break;
 296     case RANGE_NEW:
 297       s = format (s, "\n%Unew %U", format_white_space, indent,
 298                   format_ip4_full_reass_range_trace, &t->trace_range);
 299       break;
 300     case RANGE_OVERLAP:
 301       s = format (s, "\n%Uoverlapping/ignored %U", format_white_space, indent,
 302                   format_ip4_full_reass_range_trace, &t->trace_range);
 303       break;
 304     case FINALIZE:
 305       s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
 306       break;
 307     case HANDOFF:
 308       s =
 309         format (s, "handoff from thread #%u to thread #%u", t->thread_id,
 310                 t->thread_id_to);
 311       break;
 312     }
 313   return s;
 314 }
 315
 316 static void
 317 ip4_full_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 318                           ip4_full_reass_main_t * rm,
 319                           ip4_full_reass_t * reass, u32 bi,
 320                           ip4_full_reass_trace_operation_e action,
 321                           u32 size_diff, u32 thread_id_to)
 322 {
 323   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 324   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
 325   ip4_full_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
 326   if (reass)
 327     {
 328       t->reass_id = reass->id;
 329       t->op_id = reass->trace_op_counter;
 330       t->trace_range.first_bi = reass->first_bi;
 331       t->total_data_len = reass->data_len;
 332       ++reass->trace_op_counter;
 333     }
 334   else
 335     {
 336       t->reass_id = ~0;
 337       t->op_id = 0;
 338       t->trace_range.first_bi = 0;
 339       t->total_data_len = 0;
 340     }
 341   t->action = action;
 342   ip4_full_reass_trace_details (vm, bi, &t->trace_range);
 343   t->size_diff = size_diff;
 344   t->thread_id = vm->thread_index;
 345   t->thread_id_to = thread_id_to;
 346   t->fragment_first = vnb->ip.reass.fragment_first;
 347   t->fragment_last = vnb->ip.reass.fragment_last;
 348 #if 0
 349   static u8 *s = NULL;
 350   s = format (s, "%U", format_ip4_full_reass_trace, NULL, NULL, t);
 351   printf ("%.*s\n", vec_len (s), s);
 352   fflush (stdout);
 353   vec_reset_length (s);
 354 #endif
 355 }
 356
 357 always_inline void
 358 ip4_full_reass_free_ctx (ip4_full_reass_per_thread_t * rt,
 359                          ip4_full_reass_t * reass)
 360 {
 361   pool_put (rt->pool, reass);
 362   --rt->reass_n;
 363 }
 364
 365 always_inline void
 366 ip4_full_reass_free (ip4_full_reass_main_t * rm,
 367                      ip4_full_reass_per_thread_t * rt,
 368                      ip4_full_reass_t * reass)
 369 {
 370   clib_bihash_kv_16_8_t kv;
 371   kv.key[0] = reass->key.as_u64[0];
 372   kv.key[1] = reass->key.as_u64[1];
 373   clib_bihash_add_del_16_8 (&rm->hash, &kv, 0);
 374   return ip4_full_reass_free_ctx (rt, reass);
 375 }
 376
 377 always_inline void
 378 ip4_full_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
 379                          ip4_full_reass_main_t * rm, ip4_full_reass_t * reass)
 380 {
 381   u32 range_bi = reass->first_bi;
 382   vlib_buffer_t *range_b;
 383   vnet_buffer_opaque_t *range_vnb;
 384   u32 *to_free = NULL;
 385   while (~0 != range_bi)
 386     {
 387       range_b = vlib_get_buffer (vm, range_bi);
 388       range_vnb = vnet_buffer (range_b);
 389       u32 bi = range_bi;
 390       while (~0 != bi)
 391         {
 392           vec_add1 (to_free, bi);
 393           vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 394           if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 395             {
 396               bi = b->next_buffer;
 397               b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 398             }
 399           else
 400             {
 401               bi = ~0;
 402             }
 403         }
 404       range_bi = range_vnb->ip.reass.next_range_bi;
 405     }
 406   /* send to next_error_index */
 407   if (~0 != reass->error_next_index)
 408     {
 409       u32 n_left_to_next, *to_next, next_index;
 410
 411       next_index = reass->error_next_index;
 412       u32 bi = ~0;
 413
 414       while (vec_len (to_free) > 0)
 415         {
 416           vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 417
 418           while (vec_len (to_free) > 0 && n_left_to_next > 0)
 419             {
 420               bi = vec_pop (to_free);
 421
 422               if (~0 != bi)
 423                 {
 424                   to_next[0] = bi;
 425                   to_next += 1;
 426                   n_left_to_next -= 1;
 427                 }
 428             }
 429           vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 430         }
 431     }
 432   else
 433     {
 434       vlib_buffer_free (vm, to_free, vec_len (to_free));
 435     }
 436 }
 437
 438 always_inline void
 439 ip4_full_reass_init (ip4_full_reass_t * reass)
 440 {
 441   reass->first_bi = ~0;
 442   reass->last_packet_octet = ~0;
 443   reass->data_len = 0;
 444   reass->next_index = ~0;
 445   reass->error_next_index = ~0;
 446 }
 447
 448 always_inline ip4_full_reass_t *
 449 ip4_full_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 450                                ip4_full_reass_main_t * rm,
 451                                ip4_full_reass_per_thread_t * rt,
 452                                ip4_full_reass_kv_t * kv, u8 * do_handoff)
 453 {
 454   ip4_full_reass_t *reass;
 455   f64 now;
 456
 457 again:
 458
 459   reass = NULL;
 460   now = vlib_time_now (vm);
 461   if (!clib_bihash_search_16_8
 462       (&rm->hash, (clib_bihash_kv_16_8_t *) kv, (clib_bihash_kv_16_8_t *) kv))
 463     {
 464       reass =
 465         pool_elt_at_index (rm->per_thread_data
 466                            [kv->v.memory_owner_thread_index].pool,
 467                            kv->v.reass_index);
 468       if (vm->thread_index != reass->memory_owner_thread_index)
 469         {
 470           *do_handoff = 1;
 471           return reass;
 472         }
 473
 474       if (now > reass->last_heard + rm->timeout)
 475         {
 476           ip4_full_reass_drop_all (vm, node, rm, reass);
 477           ip4_full_reass_free (rm, rt, reass);
 478           reass = NULL;
 479         }
 480     }
 481
 482   if (reass)
 483     {
 484       reass->last_heard = now;
 485       return reass;
 486     }
 487
 488   if (rt->reass_n >= rm->max_reass_n)
 489     {
 490       reass = NULL;
 491       return reass;
 492     }
 493   else
 494     {
 495       pool_get (rt->pool, reass);
 496       clib_memset (reass, 0, sizeof (*reass));
 497       reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter;
 498       reass->memory_owner_thread_index = vm->thread_index;
 499       ++rt->id_counter;
 500       ip4_full_reass_init (reass);
 501       ++rt->reass_n;
 502     }
 503
 504   reass->key.as_u64[0] = ((clib_bihash_kv_16_8_t *) kv)->key[0];
 505   reass->key.as_u64[1] = ((clib_bihash_kv_16_8_t *) kv)->key[1];
 506   kv->v.reass_index = (reass - rt->pool);
 507   kv->v.memory_owner_thread_index = vm->thread_index;
 508   reass->last_heard = now;
 509
 510   int rv =
 511     clib_bihash_add_del_16_8 (&rm->hash, (clib_bihash_kv_16_8_t *) kv, 2);
 512   if (rv)
 513     {
 514       ip4_full_reass_free_ctx (rt, reass);
 515       reass = NULL;
 516       // if other worker created a context already work with the other copy
 517       if (-2 == rv)
 518         goto again;
 519     }
 520
 521   return reass;
 522 }
 523
 524 always_inline ip4_full_reass_rc_t
 525 ip4_full_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 526                          ip4_full_reass_main_t * rm,
 527                          ip4_full_reass_per_thread_t * rt,
 528                          ip4_full_reass_t * reass, u32 * bi0,
 529                          u32 * next0, u32 * error0, bool is_custom_app)
 530 {
 531   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
 532   vlib_buffer_t *last_b = NULL;
 533   u32 sub_chain_bi = reass->first_bi;
 534   u32 total_length = 0;
 535   u32 buf_cnt = 0;
 536   do
 537     {
 538       u32 tmp_bi = sub_chain_bi;
 539       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
 540       ip4_header_t *ip = vlib_buffer_get_current (tmp);
 541       vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
 542       if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 543           !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 544         {
 545           return IP4_REASS_RC_INTERNAL_ERROR;
 546         }
 547
 548       u32 data_len = ip4_full_reass_buffer_get_data_len (tmp);
 549       u32 trim_front =
 550         ip4_header_bytes (ip) + ip4_full_reass_buffer_get_data_offset (tmp);
 551       u32 trim_end =
 552         vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
 553       if (tmp_bi == reass->first_bi)
 554         {
 555           /* first buffer - keep ip4 header */
 556           if (0 != ip4_full_reass_buffer_get_data_offset (tmp))
 557             {
 558               return IP4_REASS_RC_INTERNAL_ERROR;
 559             }
 560           trim_front = 0;
 561           trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
 562             ip4_header_bytes (ip);
 563           if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
 564             {
 565               return IP4_REASS_RC_INTERNAL_ERROR;
 566             }
 567         }
 568       u32 keep_data =
 569         vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
 570       while (1)
 571         {
 572           ++buf_cnt;
 573           if (trim_front)
 574             {
 575               if (trim_front > tmp->current_length)
 576                 {
 577                   /* drop whole buffer */
 578                   u32 to_be_freed_bi = tmp_bi;
 579                   trim_front -= tmp->current_length;
 580                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 581                     {
 582                       return IP4_REASS_RC_INTERNAL_ERROR;
 583                     }
 584                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 585                   tmp_bi = tmp->next_buffer;
 586                   tmp->next_buffer = 0;
 587                   tmp = vlib_get_buffer (vm, tmp_bi);
 588                   vlib_buffer_free_one (vm, to_be_freed_bi);
 589                   continue;
 590                 }
 591               else
 592                 {
 593                   vlib_buffer_advance (tmp, trim_front);
 594                   trim_front = 0;
 595                 }
 596             }
 597           if (keep_data)
 598             {
 599               if (last_b)
 600                 {
 601                   last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 602                   last_b->next_buffer = tmp_bi;
 603                 }
 604               last_b = tmp;
 605               if (keep_data <= tmp->current_length)
 606                 {
 607                   tmp->current_length = keep_data;
 608                   keep_data = 0;
 609                 }
 610               else
 611                 {
 612                   keep_data -= tmp->current_length;
 613                   if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
 614                     {
 615                       return IP4_REASS_RC_INTERNAL_ERROR;
 616                     }
 617                 }
 618               total_length += tmp->current_length;
 619               if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 620                 {
 621                   tmp_bi = tmp->next_buffer;
 622                   tmp = vlib_get_buffer (vm, tmp->next_buffer);
 623                 }
 624               else
 625                 {
 626                   break;
 627                 }
 628             }
 629           else
 630             {
 631               u32 to_be_freed_bi = tmp_bi;
 632               if (reass->first_bi == tmp_bi)
 633                 {
 634                   return IP4_REASS_RC_INTERNAL_ERROR;
 635                 }
 636               if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
 637                 {
 638                   tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 639                   tmp_bi = tmp->next_buffer;
 640                   tmp->next_buffer = 0;
 641                   tmp = vlib_get_buffer (vm, tmp_bi);
 642                   vlib_buffer_free_one (vm, to_be_freed_bi);
 643                 }
 644               else
 645                 {
 646                   tmp->next_buffer = 0;
 647                   vlib_buffer_free_one (vm, to_be_freed_bi);
 648                   break;
 649                 }
 650             }
 651         }
 652       sub_chain_bi =
 653         vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
 654         reass.next_range_bi;
 655     }
 656   while (~0 != sub_chain_bi);
 657
 658   if (!last_b)
 659     {
 660       return IP4_REASS_RC_INTERNAL_ERROR;
 661     }
 662   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 663
 664   if (total_length < first_b->current_length)
 665     {
 666       return IP4_REASS_RC_INTERNAL_ERROR;
 667     }
 668   total_length -= first_b->current_length;
 669   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
 670   first_b->total_length_not_including_first_buffer = total_length;
 671   ip4_header_t *ip = vlib_buffer_get_current (first_b);
 672   ip->flags_and_fragment_offset = 0;
 673   ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
 674   ip->checksum = ip4_header_checksum (ip);
 675   if (!vlib_buffer_chain_linearize (vm, first_b))
 676     {
 677       return IP4_REASS_RC_NO_BUF;
 678     }
 679   // reset to reconstruct the mbuf linking
 680   first_b->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
 681   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
 682     {
 683       ip4_full_reass_add_trace (vm, node, rm, reass, reass->first_bi,
 684                                 FINALIZE, 0, ~0);
 685 #if 0
 686       // following code does a hexdump of packet fragments to stdout ...
 687       do
 688         {
 689           u32 bi = reass->first_bi;
 690           u8 *s = NULL;
 691           while (~0 != bi)
 692             {
 693               vlib_buffer_t *b = vlib_get_buffer (vm, bi);
 694               s = format (s, "%u: %U\n", bi, format_hexdump,
 695                           vlib_buffer_get_current (b), b->current_length);
 696               if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 697                 {
 698                   bi = b->next_buffer;
 699                 }
 700               else
 701                 {
 702                   break;
 703                 }
 704             }
 705           printf ("%.*s\n", vec_len (s), s);
 706           fflush (stdout);
 707           vec_free (s);
 708         }
 709       while (0);
 710 #endif
 711     }
 712   *bi0 = reass->first_bi;
 713   if (!is_custom_app)
 714     {
 715       *next0 = IP4_FULL_REASS_NEXT_INPUT;
 716     }
 717   else
 718     {
 719       *next0 = reass->next_index;
 720     }
 721   vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
 722   *error0 = IP4_ERROR_NONE;
 723   ip4_full_reass_free (rm, rt, reass);
 724   reass = NULL;
 725   return IP4_REASS_RC_OK;
 726 }
 727
 728 always_inline ip4_full_reass_rc_t
 729 ip4_full_reass_insert_range_in_chain (vlib_main_t * vm,
 730                                       ip4_full_reass_main_t * rm,
 731                                       ip4_full_reass_per_thread_t * rt,
 732                                       ip4_full_reass_t * reass,
 733                                       u32 prev_range_bi, u32 new_next_bi)
 734 {
 735   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
 736   vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
 737   if (~0 != prev_range_bi)
 738     {
 739       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 740       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 741       new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
 742       prev_vnb->ip.reass.next_range_bi = new_next_bi;
 743     }
 744   else
 745     {
 746       if (~0 != reass->first_bi)
 747         {
 748           new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
 749         }
 750       reass->first_bi = new_next_bi;
 751     }
 752   vnet_buffer_opaque_t *vnb = vnet_buffer (new_next_b);
 753   if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 754       !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 755     {
 756       return IP4_REASS_RC_INTERNAL_ERROR;
 757     }
 758   reass->data_len += ip4_full_reass_buffer_get_data_len (new_next_b);
 759   return IP4_REASS_RC_OK;
 760 }
 761
 762 always_inline ip4_full_reass_rc_t
 763 ip4_full_reass_remove_range_from_chain (vlib_main_t * vm,
 764                                         vlib_node_runtime_t * node,
 765                                         ip4_full_reass_main_t * rm,
 766                                         ip4_full_reass_t * reass,
 767                                         u32 prev_range_bi, u32 discard_bi)
 768 {
 769   vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi);
 770   vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b);
 771   if (~0 != prev_range_bi)
 772     {
 773       vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
 774       vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
 775       if (!(prev_vnb->ip.reass.next_range_bi == discard_bi))
 776         {
 777           return IP4_REASS_RC_INTERNAL_ERROR;
 778         }
 779       prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi;
 780     }
 781   else
 782     {
 783       reass->first_bi = discard_vnb->ip.reass.next_range_bi;
 784     }
 785   vnet_buffer_opaque_t *vnb = vnet_buffer (discard_b);
 786   if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
 787       !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
 788     {
 789       return IP4_REASS_RC_INTERNAL_ERROR;
 790     }
 791   reass->data_len -= ip4_full_reass_buffer_get_data_len (discard_b);
 792   while (1)
 793     {
 794       u32 to_be_freed_bi = discard_bi;
 795       if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED))
 796         {
 797           ip4_full_reass_add_trace (vm, node, rm, reass, discard_bi,
 798                                     RANGE_DISCARD, 0, ~0);
 799         }
 800       if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT)
 801         {
 802           discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
 803           discard_bi = discard_b->next_buffer;
 804           discard_b->next_buffer = 0;
 805           discard_b = vlib_get_buffer (vm, discard_bi);
 806           vlib_buffer_free_one (vm, to_be_freed_bi);
 807         }
 808       else
 809         {
 810           discard_b->next_buffer = 0;
 811           vlib_buffer_free_one (vm, to_be_freed_bi);
 812           break;
 813         }
 814     }
 815   return IP4_REASS_RC_OK;
 816 }
 817
 818 always_inline ip4_full_reass_rc_t
 819 ip4_full_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 820                        ip4_full_reass_main_t * rm,
 821                        ip4_full_reass_per_thread_t * rt,
 822                        ip4_full_reass_t * reass, u32 * bi0, u32 * next0,
 823                        u32 * error0, bool is_custom_app,
 824                        u32 * handoff_thread_idx)
 825 {
 826   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
 827   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
 828   if (is_custom_app)
 829     {
 830       // store (error_)next_index before it's overwritten
 831       reass->next_index = fvnb->ip.reass.next_index;
 832       reass->error_next_index = fvnb->ip.reass.error_next_index;
 833     }
 834   ip4_full_reass_rc_t rc = IP4_REASS_RC_OK;
 835   int consumed = 0;
 836   ip4_header_t *fip = vlib_buffer_get_current (fb);
 837   const u32 fragment_first = ip4_get_fragment_offset_bytes (fip);
 838   const u32 fragment_length =
 839     clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
 840   const u32 fragment_last = fragment_first + fragment_length - 1;
 841   fvnb->ip.reass.fragment_first = fragment_first;
 842   fvnb->ip.reass.fragment_last = fragment_last;
 843   int more_fragments = ip4_get_fragment_more (fip);
 844   u32 candidate_range_bi = reass->first_bi;
 845   u32 prev_range_bi = ~0;
 846   fvnb->ip.reass.range_first = fragment_first;
 847   fvnb->ip.reass.range_last = fragment_last;
 848   fvnb->ip.reass.next_range_bi = ~0;
 849   if (!more_fragments)
 850     {
 851       reass->last_packet_octet = fragment_last;
 852     }
 853   if (~0 == reass->first_bi)
 854     {
 855       // starting a new reassembly
 856       rc =
 857         ip4_full_reass_insert_range_in_chain (vm, rm, rt, reass,
 858                                               prev_range_bi, *bi0);
 859       if (IP4_REASS_RC_OK != rc)
 860         {
 861           return rc;
 862         }
 863       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 864         {
 865           ip4_full_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0,
 866                                     ~0);
 867         }
 868       *bi0 = ~0;
 869       reass->min_fragment_length = clib_net_to_host_u16 (fip->length);
 870       reass->fragments_n = 1;
 871       return IP4_REASS_RC_OK;
 872     }
 873   reass->min_fragment_length =
 874     clib_min (clib_net_to_host_u16 (fip->length),
 875               fvnb->ip.reass.estimated_mtu);
 876   while (~0 != candidate_range_bi)
 877     {
 878       vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
 879       vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
 880       if (fragment_first > candidate_vnb->ip.reass.range_last)
 881         {
 882           // this fragments starts after candidate range
 883           prev_range_bi = candidate_range_bi;
 884           candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
 885           if (candidate_vnb->ip.reass.range_last < fragment_last &&
 886               ~0 == candidate_range_bi)
 887             {
 888               // special case - this fragment falls beyond all known ranges
 889               rc =
 890                 ip4_full_reass_insert_range_in_chain (vm, rm, rt, reass,
 891                                                       prev_range_bi, *bi0);
 892               if (IP4_REASS_RC_OK != rc)
 893                 {
 894                   return rc;
 895                 }
 896               consumed = 1;
 897               break;
 898             }
 899           continue;
 900         }
 901       if (fragment_last < candidate_vnb->ip.reass.range_first)
 902         {
 903           // this fragment ends before candidate range without any overlap
 904           rc =
 905             ip4_full_reass_insert_range_in_chain (vm, rm, rt, reass,
 906                                                   prev_range_bi, *bi0);
 907           if (IP4_REASS_RC_OK != rc)
 908             {
 909               return rc;
 910             }
 911           consumed = 1;
 912         }
 913       else
 914         {
 915           if (fragment_first >= candidate_vnb->ip.reass.range_first &&
 916               fragment_last <= candidate_vnb->ip.reass.range_last)
 917             {
 918               // this fragment is a (sub)part of existing range, ignore it
 919               if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 920                 {
 921                   ip4_full_reass_add_trace (vm, node, rm, reass, *bi0,
 922                                             RANGE_OVERLAP, 0, ~0);
 923                 }
 924               break;
 925             }
 926           int discard_candidate = 0;
 927           if (fragment_first < candidate_vnb->ip.reass.range_first)
 928             {
 929               u32 overlap =
 930                 fragment_last - candidate_vnb->ip.reass.range_first + 1;
 931               if (overlap < ip4_full_reass_buffer_get_data_len (candidate_b))
 932                 {
 933                   candidate_vnb->ip.reass.range_first += overlap;
 934                   if (reass->data_len < overlap)
 935                     {
 936                       return IP4_REASS_RC_INTERNAL_ERROR;
 937                     }
 938                   reass->data_len -= overlap;
 939                   if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 940                     {
 941                       ip4_full_reass_add_trace (vm, node, rm, reass,
 942                                                 candidate_range_bi,
 943                                                 RANGE_SHRINK, 0, ~0);
 944                     }
 945                   rc =
 946                     ip4_full_reass_insert_range_in_chain (vm, rm, rt, reass,
 947                                                           prev_range_bi,
 948                                                           *bi0);
 949                   if (IP4_REASS_RC_OK != rc)
 950                     {
 951                       return rc;
 952                     }
 953                   consumed = 1;
 954                 }
 955               else
 956                 {
 957                   discard_candidate = 1;
 958                 }
 959             }
 960           else if (fragment_last > candidate_vnb->ip.reass.range_last)
 961             {
 962               u32 overlap =
 963                 candidate_vnb->ip.reass.range_last - fragment_first + 1;
 964               if (overlap < ip4_full_reass_buffer_get_data_len (candidate_b))
 965                 {
 966                   fvnb->ip.reass.range_first += overlap;
 967                   if (~0 != candidate_vnb->ip.reass.next_range_bi)
 968                     {
 969                       prev_range_bi = candidate_range_bi;
 970                       candidate_range_bi =
 971                         candidate_vnb->ip.reass.next_range_bi;
 972                       continue;
 973                     }
 974                   else
 975                     {
 976                       // special case - last range discarded
 977                       rc =
 978                         ip4_full_reass_insert_range_in_chain (vm, rm, rt,
 979                                                               reass,
 980                                                               candidate_range_bi,
 981                                                               *bi0);
 982                       if (IP4_REASS_RC_OK != rc)
 983                         {
 984                           return rc;
 985                         }
 986                       consumed = 1;
 987                     }
 988                 }
 989               else
 990                 {
 991                   discard_candidate = 1;
 992                 }
 993             }
 994           else
 995             {
 996               discard_candidate = 1;
 997             }
 998           if (discard_candidate)
 999             {
1000               u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi;
1001               // discard candidate range, probe next range
1002               rc =
1003                 ip4_full_reass_remove_range_from_chain (vm, node, rm, reass,
1004                                                         prev_range_bi,
1005                                                         candidate_range_bi);
1006               if (IP4_REASS_RC_OK != rc)
1007                 {
1008                   return rc;
1009                 }
1010               if (~0 != next_range_bi)
1011                 {
1012                   candidate_range_bi = next_range_bi;
1013                   continue;
1014                 }
1015               else
1016                 {
1017                   // special case - last range discarded
1018                   rc =
1019                     ip4_full_reass_insert_range_in_chain (vm, rm, rt, reass,
1020                                                           prev_range_bi,
1021                                                           *bi0);
1022                   if (IP4_REASS_RC_OK != rc)
1023                     {
1024                       return rc;
1025                     }
1026                   consumed = 1;
1027                 }
1028             }
1029         }
1030       break;
1031     }
1032   ++reass->fragments_n;
1033   if (consumed)
1034     {
1035       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
1036         {
1037           ip4_full_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0,
1038                                     ~0);
1039         }
1040     }
1041   if (~0 != reass->last_packet_octet &&
1042       reass->data_len == reass->last_packet_octet + 1)
1043     {
1044       *handoff_thread_idx = reass->sendout_thread_index;
1045       int handoff =
1046         reass->memory_owner_thread_index != reass->sendout_thread_index;
1047       rc =
1048         ip4_full_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
1049                                  is_custom_app);
1050       if (IP4_REASS_RC_OK == rc && handoff)
1051         {
1052           rc = IP4_REASS_RC_HANDOFF;
1053         }
1054     }
1055   else
1056     {
1057       if (consumed)
1058         {
1059           *bi0 = ~0;
1060           if (reass->fragments_n > rm->max_reass_len)
1061             {
1062               rc = IP4_REASS_RC_TOO_MANY_FRAGMENTS;
1063             }
1064         }
1065       else
1066         {
1067           *next0 = IP4_FULL_REASS_NEXT_DROP;
1068           *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT;
1069         }
1070     }
1071   return rc;
1072 }
1073
1074 always_inline uword
1075 ip4_full_reass_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1076                        vlib_frame_t * frame, bool is_feature,
1077                        bool is_custom_app)
1078 {
1079   u32 *from = vlib_frame_vector_args (frame);
1080   u32 n_left_from, n_left_to_next, *to_next, next_index;
1081   ip4_full_reass_main_t *rm = &ip4_full_reass_main;
1082   ip4_full_reass_per_thread_t *rt = &rm->per_thread_data[vm->thread_index];
1083   clib_spinlock_lock (&rt->lock);
1084
1085   n_left_from = frame->n_vectors;
1086   next_index = node->cached_next_index;
1087   while (n_left_from > 0)
1088     {
1089       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1090
1091       while (n_left_from > 0 && n_left_to_next > 0)
1092         {
1093           u32 bi0;
1094           vlib_buffer_t *b0;
1095           u32 next0;
1096           u32 error0 = IP4_ERROR_NONE;
1097
1098           bi0 = from[0];
1099           b0 = vlib_get_buffer (vm, bi0);
1100
1101           ip4_header_t *ip0 = vlib_buffer_get_current (b0);
1102           if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
1103             {
1104               // this is a whole packet - no fragmentation
1105               if (!is_custom_app)
1106                 {
1107                   next0 = IP4_FULL_REASS_NEXT_INPUT;
1108                 }
1109               else
1110                 {
1111                   next0 = vnet_buffer (b0)->ip.reass.next_index;
1112                 }
1113               goto packet_enqueue;
1114             }
1115           const u32 fragment_first = ip4_get_fragment_offset_bytes (ip0);
1116           const u32 fragment_length =
1117             clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0);
1118           const u32 fragment_last = fragment_first + fragment_length - 1;
1119           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
1120             {
1121               next0 = IP4_FULL_REASS_NEXT_DROP;
1122               error0 = IP4_ERROR_REASS_MALFORMED_PACKET;
1123               goto packet_enqueue;
1124             }
1125           ip4_full_reass_kv_t kv;
1126           u8 do_handoff = 0;
1127
1128           kv.k.as_u64[0] =
1129             (u64) vec_elt (ip4_main.fib_index_by_sw_if_index,
1130                            vnet_buffer (b0)->sw_if_index[VLIB_RX]) |
1131             (u64) ip0->src_address.as_u32 << 32;
1132           kv.k.as_u64[1] =
1133             (u64) ip0->dst_address.
1134             as_u32 | (u64) ip0->fragment_id << 32 | (u64) ip0->protocol << 48;
1135
1136           ip4_full_reass_t *reass =
1137             ip4_full_reass_find_or_create (vm, node, rm, rt, &kv,
1138                                            &do_handoff);
1139
1140           if (reass)
1141             {
1142               const u32 fragment_first = ip4_get_fragment_offset_bytes (ip0);
1143               if (0 == fragment_first)
1144                 {
1145                   reass->sendout_thread_index = vm->thread_index;
1146                 }
1147             }
1148
1149           if (PREDICT_FALSE (do_handoff))
1150             {
1151               next0 = IP4_FULL_REASS_NEXT_HANDOFF;
1152               vnet_buffer (b0)->ip.reass.owner_thread_index =
1153                 kv.v.memory_owner_thread_index;
1154             }
1155           else if (reass)
1156             {
1157               u32 handoff_thread_idx;
1158               switch (ip4_full_reass_update
1159                       (vm, node, rm, rt, reass, &bi0, &next0,
1160                        &error0, is_custom_app, &handoff_thread_idx))
1161                 {
1162                 case IP4_REASS_RC_OK:
1163                   /* nothing to do here */
1164                   break;
1165                 case IP4_REASS_RC_HANDOFF:
1166                   next0 = IP4_FULL_REASS_NEXT_HANDOFF;
1167                   b0 = vlib_get_buffer (vm, bi0);
1168                   vnet_buffer (b0)->ip.reass.owner_thread_index =
1169                     handoff_thread_idx;
1170                   break;
1171                 case IP4_REASS_RC_TOO_MANY_FRAGMENTS:
1172                   vlib_node_increment_counter (vm, node->node_index,
1173                                                IP4_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
1174                                                1);
1175                   ip4_full_reass_drop_all (vm, node, rm, reass);
1176                   ip4_full_reass_free (rm, rt, reass);
1177                   goto next_packet;
1178                   break;
1179                 case IP4_REASS_RC_NO_BUF:
1180                   vlib_node_increment_counter (vm, node->node_index,
1181                                                IP4_ERROR_REASS_NO_BUF, 1);
1182                   ip4_full_reass_drop_all (vm, node, rm, reass);
1183                   ip4_full_reass_free (rm, rt, reass);
1184                   goto next_packet;
1185                   break;
1186                 case IP4_REASS_RC_INTERNAL_ERROR:
1187                   /* drop everything and start with a clean slate */
1188                   vlib_node_increment_counter (vm, node->node_index,
1189                                                IP4_ERROR_REASS_INTERNAL_ERROR,
1190                                                1);
1191                   ip4_full_reass_drop_all (vm, node, rm, reass);
1192                   ip4_full_reass_free (rm, rt, reass);
1193                   goto next_packet;
1194                   break;
1195                 }
1196             }
1197           else
1198             {
1199               next0 = IP4_FULL_REASS_NEXT_DROP;
1200               error0 = IP4_ERROR_REASS_LIMIT_REACHED;
1201             }
1202
1203
1204         packet_enqueue:
1205           b0->error = node->errors[error0];
1206
1207           if (bi0 != ~0)
1208             {
1209               to_next[0] = bi0;
1210               to_next += 1;
1211               n_left_to_next -= 1;
1212               if (next0 == IP4_FULL_REASS_NEXT_HANDOFF)
1213                 {
1214                   if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1215                     {
1216                       ip4_full_reass_add_trace (vm, node, rm, NULL, bi0,
1217                                                 HANDOFF, 0,
1218                                                 vnet_buffer (b0)->ip.
1219                                                 reass.owner_thread_index);
1220                     }
1221                 }
1222               else if (is_feature && IP4_ERROR_NONE == error0)
1223                 {
1224                   b0 = vlib_get_buffer (vm, bi0);
1225                   vnet_feature_next (&next0, b0);
1226                 }
1227               vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
1228                                                to_next, n_left_to_next,
1229                                                bi0, next0);
1230               IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next);
1231             }
1232
1233         next_packet:
1234           from += 1;
1235           n_left_from -= 1;
1236         }
1237
1238       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1239     }
1240
1241   clib_spinlock_unlock (&rt->lock);
1242   return frame->n_vectors;
1243 }
1244
1245 static char *ip4_full_reass_error_strings[] = {
1246 #define _(sym, string) string,
1247   foreach_ip4_error
1248 #undef _
1249 };
1250
1251 VLIB_NODE_FN (ip4_full_reass_node) (vlib_main_t * vm,
1252                                     vlib_node_runtime_t * node,
1253                                     vlib_frame_t * frame)
1254 {
1255   return ip4_full_reass_inline (vm, node, frame, false /* is_feature */ ,
1256                                 false /* is_custom_app */ );
1257 }
1258
1259 /* *INDENT-OFF* */
1260 VLIB_REGISTER_NODE (ip4_full_reass_node) = {
1261     .name = "ip4-full-reassembly",
1262     .vector_size = sizeof (u32),
1263     .format_trace = format_ip4_full_reass_trace,
1264     .n_errors = ARRAY_LEN (ip4_full_reass_error_strings),
1265     .error_strings = ip4_full_reass_error_strings,
1266     .n_next_nodes = IP4_FULL_REASS_N_NEXT,
1267     .next_nodes =
1268         {
1269                 [IP4_FULL_REASS_NEXT_INPUT] = "ip4-input",
1270                 [IP4_FULL_REASS_NEXT_DROP] = "ip4-drop",
1271                 [IP4_FULL_REASS_NEXT_HANDOFF] = "ip4-full-reassembly-handoff",
1272
1273         },
1274 };
1275 /* *INDENT-ON* */
1276
1277 VLIB_NODE_FN (ip4_full_reass_node_feature) (vlib_main_t * vm,
1278                                             vlib_node_runtime_t * node,
1279                                             vlib_frame_t * frame)
1280 {
1281   return ip4_full_reass_inline (vm, node, frame, true /* is_feature */ ,
1282                                 false /* is_custom_app */ );
1283 }
1284
1285 /* *INDENT-OFF* */
1286 VLIB_REGISTER_NODE (ip4_full_reass_node_feature) = {
1287     .name = "ip4-full-reassembly-feature",
1288     .vector_size = sizeof (u32),
1289     .format_trace = format_ip4_full_reass_trace,
1290     .n_errors = ARRAY_LEN (ip4_full_reass_error_strings),
1291     .error_strings = ip4_full_reass_error_strings,
1292     .n_next_nodes = IP4_FULL_REASS_N_NEXT,
1293     .next_nodes =
1294         {
1295                 [IP4_FULL_REASS_NEXT_INPUT] = "ip4-input",
1296                 [IP4_FULL_REASS_NEXT_DROP] = "ip4-drop",
1297                 [IP4_FULL_REASS_NEXT_HANDOFF] = "ip4-full-reass-feature-hoff",
1298         },
1299 };
1300 /* *INDENT-ON* */
1301
1302 /* *INDENT-OFF* */
1303 VNET_FEATURE_INIT (ip4_full_reass_feature, static) = {
1304     .arc_name = "ip4-unicast",
1305     .node_name = "ip4-full-reassembly-feature",
1306     .runs_before = VNET_FEATURES ("ip4-lookup",
1307                                   "ipsec4-input-feature"),
1308     .runs_after = 0,
1309 };
1310 /* *INDENT-ON* */
1311
1312 #ifndef CLIB_MARCH_VARIANT
1313 always_inline u32
1314 ip4_full_reass_get_nbuckets ()
1315 {
1316   ip4_full_reass_main_t *rm = &ip4_full_reass_main;
1317   u32 nbuckets;
1318   u8 i;
1319
1320   nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR);
1321
1322   for (i = 0; i < 31; i++)
1323     if ((1 << i) >= nbuckets)
1324       break;
1325   nbuckets = 1 << i;
1326
1327   return nbuckets;
1328 }
1329 #endif /* CLIB_MARCH_VARIANT */
1330
1331 typedef enum
1332 {
1333   IP4_EVENT_CONFIG_CHANGED = 1,
1334 } ip4_full_reass_event_t;
1335
1336 typedef struct
1337 {
1338   int failure;
1339   clib_bihash_16_8_t *new_hash;
1340 } ip4_rehash_cb_ctx;
1341
1342 #ifndef CLIB_MARCH_VARIANT
1343 static void
1344 ip4_rehash_cb (clib_bihash_kv_16_8_t * kv, void *_ctx)
1345 {
1346   ip4_rehash_cb_ctx *ctx = _ctx;
1347   if (clib_bihash_add_del_16_8 (ctx->new_hash, kv, 1))
1348     {
1349       ctx->failure = 1;
1350     }
1351 }
1352
1353 static void
1354 ip4_full_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
1355                            u32 max_reassembly_length,
1356                            u32 expire_walk_interval_ms)
1357 {
1358   ip4_full_reass_main.timeout_ms = timeout_ms;
1359   ip4_full_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
1360   ip4_full_reass_main.max_reass_n = max_reassemblies;
1361   ip4_full_reass_main.max_reass_len = max_reassembly_length;
1362   ip4_full_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
1363 }
1364
1365 vnet_api_error_t
1366 ip4_full_reass_set (u32 timeout_ms, u32 max_reassemblies,
1367                     u32 max_reassembly_length, u32 expire_walk_interval_ms)
1368 {
1369   u32 old_nbuckets = ip4_full_reass_get_nbuckets ();
1370   ip4_full_reass_set_params (timeout_ms, max_reassemblies,
1371                              max_reassembly_length, expire_walk_interval_ms);
1372   vlib_process_signal_event (ip4_full_reass_main.vlib_main,
1373                              ip4_full_reass_main.ip4_full_reass_expire_node_idx,
1374                              IP4_EVENT_CONFIG_CHANGED, 0);
1375   u32 new_nbuckets = ip4_full_reass_get_nbuckets ();
1376   if (ip4_full_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
1377     {
1378       clib_bihash_16_8_t new_hash;
1379       clib_memset (&new_hash, 0, sizeof (new_hash));
1380       ip4_rehash_cb_ctx ctx;
1381       ctx.failure = 0;
1382       ctx.new_hash = &new_hash;
1383       clib_bihash_init_16_8 (&new_hash, "ip4-dr", new_nbuckets,
1384                              new_nbuckets * 1024);
1385       clib_bihash_foreach_key_value_pair_16_8 (&ip4_full_reass_main.hash,
1386                                                ip4_rehash_cb, &ctx);
1387       if (ctx.failure)
1388         {
1389           clib_bihash_free_16_8 (&new_hash);
1390           return -1;
1391         }
1392       else
1393         {
1394           clib_bihash_free_16_8 (&ip4_full_reass_main.hash);
1395           clib_memcpy_fast (&ip4_full_reass_main.hash, &new_hash,
1396                             sizeof (ip4_full_reass_main.hash));
1397           clib_bihash_copied (&ip4_full_reass_main.hash, &new_hash);
1398         }
1399     }
1400   return 0;
1401 }
1402
1403 vnet_api_error_t
1404 ip4_full_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
1405                     u32 * max_reassembly_length,
1406                     u32 * expire_walk_interval_ms)
1407 {
1408   *timeout_ms = ip4_full_reass_main.timeout_ms;
1409   *max_reassemblies = ip4_full_reass_main.max_reass_n;
1410   *max_reassembly_length = ip4_full_reass_main.max_reass_len;
1411   *expire_walk_interval_ms = ip4_full_reass_main.expire_walk_interval_ms;
1412   return 0;
1413 }
1414
1415 static clib_error_t *
1416 ip4_full_reass_init_function (vlib_main_t * vm)
1417 {
1418   ip4_full_reass_main_t *rm = &ip4_full_reass_main;
1419   clib_error_t *error = 0;
1420   u32 nbuckets;
1421   vlib_node_t *node;
1422
1423   rm->vlib_main = vm;
1424
1425   vec_validate (rm->per_thread_data, vlib_num_workers ());
1426   ip4_full_reass_per_thread_t *rt;
1427   vec_foreach (rt, rm->per_thread_data)
1428   {
1429     clib_spinlock_init (&rt->lock);
1430     pool_alloc (rt->pool, rm->max_reass_n);
1431   }
1432
1433   node = vlib_get_node_by_name (vm, (u8 *) "ip4-full-reassembly-expire-walk");
1434   ASSERT (node);
1435   rm->ip4_full_reass_expire_node_idx = node->index;
1436
1437   ip4_full_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS,
1438                              IP4_REASS_MAX_REASSEMBLIES_DEFAULT,
1439                              IP4_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT,
1440                              IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
1441
1442   nbuckets = ip4_full_reass_get_nbuckets ();
1443   clib_bihash_init_16_8 (&rm->hash, "ip4-dr", nbuckets, nbuckets * 1024);
1444
1445   node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
1446   ASSERT (node);
1447   rm->ip4_drop_idx = node->index;
1448
1449   rm->fq_index = vlib_frame_queue_main_init (ip4_full_reass_node.index, 0);
1450   rm->fq_feature_index =
1451     vlib_frame_queue_main_init (ip4_full_reass_node_feature.index, 0);
1452
1453   rm->feature_use_refcount_per_intf = NULL;
1454   return error;
1455 }
1456
1457 VLIB_INIT_FUNCTION (ip4_full_reass_init_function);
1458 #endif /* CLIB_MARCH_VARIANT */
1459
1460 static uword
1461 ip4_full_reass_walk_expired (vlib_main_t * vm,
1462                              vlib_node_runtime_t * node, vlib_frame_t * f)
1463 {
1464   ip4_full_reass_main_t *rm = &ip4_full_reass_main;
1465   uword event_type, *event_data = 0;
1466
1467   while (true)
1468     {
1469       vlib_process_wait_for_event_or_clock (vm,
1470                                             (f64)
1471                                             rm->expire_walk_interval_ms /
1472                                             (f64) MSEC_PER_SEC);
1473       event_type = vlib_process_get_events (vm, &event_data);
1474
1475       switch (event_type)
1476         {
1477         case ~0:                /* no events => timeout */
1478           /* nothing to do here */
1479           break;
1480         case IP4_EVENT_CONFIG_CHANGED:
1481           break;
1482         default:
1483           clib_warning ("BUG: event type 0x%wx", event_type);
1484           break;
1485         }
1486       f64 now = vlib_time_now (vm);
1487
1488       ip4_full_reass_t *reass;
1489       int *pool_indexes_to_free = NULL;
1490
1491       uword thread_index = 0;
1492       int index;
1493       const uword nthreads = vlib_num_workers () + 1;
1494       for (thread_index = 0; thread_index < nthreads; ++thread_index)
1495         {
1496           ip4_full_reass_per_thread_t *rt =
1497             &rm->per_thread_data[thread_index];
1498           clib_spinlock_lock (&rt->lock);
1499
1500           vec_reset_length (pool_indexes_to_free);
1501           /* *INDENT-OFF* */
1502           pool_foreach_index (index, rt->pool, ({
1503                                 reass = pool_elt_at_index (rt->pool, index);
1504                                 if (now > reass->last_heard + rm->timeout)
1505                                   {
1506                                     vec_add1 (pool_indexes_to_free, index);
1507                                   }
1508                               }));
1509           /* *INDENT-ON* */
1510           int *i;
1511           /* *INDENT-OFF* */
1512           vec_foreach (i, pool_indexes_to_free)
1513           {
1514             ip4_full_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
1515             ip4_full_reass_drop_all (vm, node, rm, reass);
1516             ip4_full_reass_free (rm, rt, reass);
1517           }
1518           /* *INDENT-ON* */
1519
1520           clib_spinlock_unlock (&rt->lock);
1521         }
1522
1523       vec_free (pool_indexes_to_free);
1524       if (event_data)
1525         {
1526           _vec_len (event_data) = 0;
1527         }
1528     }
1529
1530   return 0;
1531 }
1532
1533 /* *INDENT-OFF* */
1534 VLIB_REGISTER_NODE (ip4_full_reass_expire_node) = {
1535     .function = ip4_full_reass_walk_expired,
1536     .type = VLIB_NODE_TYPE_PROCESS,
1537     .name = "ip4-full-reassembly-expire-walk",
1538     .format_trace = format_ip4_full_reass_trace,
1539     .n_errors = ARRAY_LEN (ip4_full_reass_error_strings),
1540     .error_strings = ip4_full_reass_error_strings,
1541
1542 };
1543 /* *INDENT-ON* */
1544
1545 static u8 *
1546 format_ip4_full_reass_key (u8 * s, va_list * args)
1547 {
1548   ip4_full_reass_key_t *key = va_arg (*args, ip4_full_reass_key_t *);
1549   s =
1550     format (s,
1551             "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
1552             key->xx_id, format_ip4_address, &key->src, format_ip4_address,
1553             &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
1554   return s;
1555 }
1556
1557 static u8 *
1558 format_ip4_reass (u8 * s, va_list * args)
1559 {
1560   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
1561   ip4_full_reass_t *reass = va_arg (*args, ip4_full_reass_t *);
1562
1563   s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
1564               "last_packet_octet: %u, trace_op_counter: %u\n",
1565               reass->id, format_ip4_full_reass_key, &reass->key,
1566               reass->first_bi, reass->data_len,
1567               reass->last_packet_octet, reass->trace_op_counter);
1568
1569   u32 bi = reass->first_bi;
1570   u32 counter = 0;
1571   while (~0 != bi)
1572     {
1573       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
1574       vnet_buffer_opaque_t *vnb = vnet_buffer (b);
1575       s =
1576         format (s,
1577                 "  #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
1578                 "fragment[%u, %u]\n", counter, vnb->ip.reass.range_first,
1579                 vnb->ip.reass.range_last, bi,
1580                 ip4_full_reass_buffer_get_data_offset (b),
1581                 ip4_full_reass_buffer_get_data_len (b),
1582                 vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
1583       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
1584         {
1585           bi = b->next_buffer;
1586         }
1587       else
1588         {
1589           bi = ~0;
1590         }
1591     }
1592   return s;
1593 }
1594
1595 static clib_error_t *
1596 show_ip4_reass (vlib_main_t * vm,
1597                 unformat_input_t * input,
1598                 CLIB_UNUSED (vlib_cli_command_t * lmd))
1599 {
1600   ip4_full_reass_main_t *rm = &ip4_full_reass_main;
1601
1602   vlib_cli_output (vm, "---------------------");
1603   vlib_cli_output (vm, "IP4 reassembly status");
1604   vlib_cli_output (vm, "---------------------");
1605   bool details = false;
1606   if (unformat (input, "details"))
1607     {
1608       details = true;
1609     }
1610
1611   u32 sum_reass_n = 0;
1612   ip4_full_reass_t *reass;
1613   uword thread_index;
1614   const uword nthreads = vlib_num_workers () + 1;
1615   for (thread_index = 0; thread_index < nthreads; ++thread_index)
1616     {
1617       ip4_full_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
1618       clib_spinlock_lock (&rt->lock);
1619       if (details)
1620         {
1621           /* *INDENT-OFF* */
1622           pool_foreach (reass, rt->pool, {
1623             vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass);
1624           });
1625           /* *INDENT-ON* */
1626         }
1627       sum_reass_n += rt->reass_n;
1628       clib_spinlock_unlock (&rt->lock);
1629     }
1630   vlib_cli_output (vm, "---------------------");
1631   vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
1632                    (long unsigned) sum_reass_n);
1633   vlib_cli_output (vm,
1634                    "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
1635                    (long unsigned) rm->max_reass_n);
1636   return 0;
1637 }
1638
1639 /* *INDENT-OFF* */
1640 VLIB_CLI_COMMAND (show_ip4_full_reass_cmd, static) = {
1641     .path = "show ip4-full-reassembly",
1642     .short_help = "show ip4-full-reassembly [details]",
1643     .function = show_ip4_reass,
1644 };
1645 /* *INDENT-ON* */
1646
1647 #ifndef CLIB_MARCH_VARIANT
1648 vnet_api_error_t
1649 ip4_full_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
1650 {
1651   return vnet_feature_enable_disable ("ip4-unicast",
1652                                       "ip4-full-reassembly-feature",
1653                                       sw_if_index, enable_disable, 0, 0);
1654 }
1655 #endif /* CLIB_MARCH_VARIANT */
1656
1657
1658 #define foreach_ip4_full_reass_handoff_error                       \
1659 _(CONGESTION_DROP, "congestion drop")
1660
1661
1662 typedef enum
1663 {
1664 #define _(sym,str) IP4_FULL_REASS_HANDOFF_ERROR_##sym,
1665   foreach_ip4_full_reass_handoff_error
1666 #undef _
1667     IP4_FULL_REASS_HANDOFF_N_ERROR,
1668 } ip4_full_reass_handoff_error_t;
1669
1670 static char *ip4_full_reass_handoff_error_strings[] = {
1671 #define _(sym,string) string,
1672   foreach_ip4_full_reass_handoff_error
1673 #undef _
1674 };
1675
1676 typedef struct
1677 {
1678   u32 next_worker_index;
1679 } ip4_full_reass_handoff_trace_t;
1680
1681 static u8 *
1682 format_ip4_full_reass_handoff_trace (u8 * s, va_list * args)
1683 {
1684   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
1685   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
1686   ip4_full_reass_handoff_trace_t *t =
1687     va_arg (*args, ip4_full_reass_handoff_trace_t *);
1688
1689   s =
1690     format (s, "ip4-full-reassembly-handoff: next-worker %d",
1691             t->next_worker_index);
1692
1693   return s;
1694 }
1695
1696 always_inline uword
1697 ip4_full_reass_handoff_node_inline (vlib_main_t * vm,
1698                                     vlib_node_runtime_t * node,
1699                                     vlib_frame_t * frame, bool is_feature)
1700 {
1701   ip4_full_reass_main_t *rm = &ip4_full_reass_main;
1702
1703   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
1704   u32 n_enq, n_left_from, *from;
1705   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
1706   u32 fq_index;
1707
1708   from = vlib_frame_vector_args (frame);
1709   n_left_from = frame->n_vectors;
1710   vlib_get_buffers (vm, from, bufs, n_left_from);
1711
1712   b = bufs;
1713   ti = thread_indices;
1714
1715   fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index;
1716
1717   while (n_left_from > 0)
1718     {
1719       ti[0] = vnet_buffer (b[0])->ip.reass.owner_thread_index;
1720
1721       if (PREDICT_FALSE
1722           ((node->flags & VLIB_NODE_FLAG_TRACE)
1723            && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
1724         {
1725           ip4_full_reass_handoff_trace_t *t =
1726             vlib_add_trace (vm, node, b[0], sizeof (*t));
1727           t->next_worker_index = ti[0];
1728         }
1729
1730       n_left_from -= 1;
1731       ti += 1;
1732       b += 1;
1733     }
1734   n_enq =
1735     vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
1736                                    frame->n_vectors, 1);
1737
1738   if (n_enq < frame->n_vectors)
1739     vlib_node_increment_counter (vm, node->node_index,
1740                                  IP4_FULL_REASS_HANDOFF_ERROR_CONGESTION_DROP,
1741                                  frame->n_vectors - n_enq);
1742   return frame->n_vectors;
1743 }
1744
1745 VLIB_NODE_FN (ip4_full_reass_handoff_node) (vlib_main_t * vm,
1746                                             vlib_node_runtime_t * node,
1747                                             vlib_frame_t * frame)
1748 {
1749   return ip4_full_reass_handoff_node_inline (vm, node, frame,
1750                                              false /* is_feature */ );
1751 }
1752
1753
1754 /* *INDENT-OFF* */
1755 VLIB_REGISTER_NODE (ip4_full_reass_handoff_node) = {
1756   .name = "ip4-full-reassembly-handoff",
1757   .vector_size = sizeof (u32),
1758   .n_errors = ARRAY_LEN(ip4_full_reass_handoff_error_strings),
1759   .error_strings = ip4_full_reass_handoff_error_strings,
1760   .format_trace = format_ip4_full_reass_handoff_trace,
1761
1762   .n_next_nodes = 1,
1763
1764   .next_nodes = {
1765     [0] = "error-drop",
1766   },
1767 };
1768 /* *INDENT-ON* */
1769
1770
1771 /* *INDENT-OFF* */
1772 VLIB_NODE_FN (ip4_full_reass_feature_handoff_node) (vlib_main_t * vm,
1773                                                     vlib_node_runtime_t *
1774                                                     node,
1775                                                     vlib_frame_t * frame)
1776 {
1777   return ip4_full_reass_handoff_node_inline (vm, node, frame,
1778                                              true /* is_feature */ );
1779 }
1780 /* *INDENT-ON* */
1781
1782
1783 /* *INDENT-OFF* */
1784 VLIB_REGISTER_NODE (ip4_full_reass_feature_handoff_node) = {
1785   .name = "ip4-full-reass-feature-hoff",
1786   .vector_size = sizeof (u32),
1787   .n_errors = ARRAY_LEN(ip4_full_reass_handoff_error_strings),
1788   .error_strings = ip4_full_reass_handoff_error_strings,
1789   .format_trace = format_ip4_full_reass_handoff_trace,
1790
1791   .n_next_nodes = 1,
1792
1793   .next_nodes = {
1794     [0] = "error-drop",
1795   },
1796 };
1797 /* *INDENT-ON* */
1798
1799 #ifndef CLIB_MARCH_VARIANT
1800 int
1801 ip4_full_reass_enable_disable_with_refcnt (u32 sw_if_index, int is_enable)
1802 {
1803   ip4_full_reass_main_t *rm = &ip4_full_reass_main;
1804   vec_validate (rm->feature_use_refcount_per_intf, sw_if_index);
1805   if (is_enable)
1806     {
1807       if (!rm->feature_use_refcount_per_intf[sw_if_index])
1808         {
1809           ++rm->feature_use_refcount_per_intf[sw_if_index];
1810           return vnet_feature_enable_disable ("ip4-unicast",
1811                                               "ip4-full-reassembly-feature",
1812                                               sw_if_index, 1, 0, 0);
1813         }
1814       ++rm->feature_use_refcount_per_intf[sw_if_index];
1815     }
1816   else
1817     {
1818       --rm->feature_use_refcount_per_intf[sw_if_index];
1819       if (!rm->feature_use_refcount_per_intf[sw_if_index])
1820         return vnet_feature_enable_disable ("ip4-unicast",
1821                                             "ip4-full-reassembly-feature",
1822                                             sw_if_index, 0, 0, 0);
1823     }
1824   return -1;
1825 }
1826 #endif
1827
1828 /*
1829  * fd.io coding-style-patch-verification: ON
1830  *
1831  * Local Variables:
1832  * eval: (c-set-style "gnu")
1833  * End:
1834  */