src/vnet/mfib/mfib_forward.c

   1 /*
   2  * Copyright (c) 2016 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 #include <vnet/mfib/mfib_itf.h>
  17 #include <vnet/mfib/mfib_entry.h>
  18 #include <vnet/dpo/replicate_dpo.h>
  19 #include <vnet/mfib/ip4_mfib.h>
  20 #include <vnet/mfib/ip6_mfib.h>
  21 #include <vnet/mfib/mfib_signal.h>
  22 #include <vnet/fib/ip4_fib.h>
  23 #include <vnet/fib/ip6_fib.h>
  24
  25 #include <vnet/ip/ip4.h>
  26 #include <vnet/vnet.h>
  27
  28 typedef struct mfib_forward_lookup_trace_t_ {
  29     u32 entry_index;
  30     u32 fib_index;
  31 } mfib_forward_lookup_trace_t;
  32
  33 static u8 *
  34 format_mfib_forward_lookup_trace (u8 * s, va_list * args)
  35 {
  36     CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  37     CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  38     mfib_forward_lookup_trace_t * t = va_arg (*args, mfib_forward_lookup_trace_t *);
  39
  40     s = format (s, "fib %d entry %d", t->fib_index, t->entry_index);
  41     return s;
  42 }
  43
  44 /* Common trace function for all ip4-forward next nodes. */
  45 void
  46 mfib_forward_lookup_trace (vlib_main_t * vm,
  47                            vlib_node_runtime_t * node,
  48                            vlib_frame_t * frame)
  49 {
  50     u32 * from, n_left;
  51     ip4_main_t * im = &ip4_main;
  52
  53     n_left = frame->n_vectors;
  54     from = vlib_frame_vector_args (frame);
  55
  56     while (n_left >= 4)
  57     {
  58         mfib_forward_lookup_trace_t * t0, * t1;
  59         vlib_buffer_t * b0, * b1;
  60         u32 bi0, bi1;
  61
  62         /* Prefetch next iteration. */
  63         vlib_prefetch_buffer_with_index (vm, from[2], LOAD);
  64         vlib_prefetch_buffer_with_index (vm, from[3], LOAD);
  65
  66         bi0 = from[0];
  67         bi1 = from[1];
  68
  69         b0 = vlib_get_buffer (vm, bi0);
  70         b1 = vlib_get_buffer (vm, bi1);
  71
  72         if (b0->flags & VLIB_BUFFER_IS_TRACED)
  73         {
  74             t0 = vlib_add_trace (vm, node, b0, sizeof (t0[0]));
  75             t0->entry_index = vnet_buffer (b0)->ip.adj_index[VLIB_TX];
  76             t0->fib_index = vec_elt (im->mfib_index_by_sw_if_index,
  77                                      vnet_buffer(b1)->sw_if_index[VLIB_RX]);
  78         }
  79         if (b1->flags & VLIB_BUFFER_IS_TRACED)
  80         {
  81             t1 = vlib_add_trace (vm, node, b1, sizeof (t1[0]));
  82             t1->entry_index = vnet_buffer (b1)->ip.adj_index[VLIB_TX];
  83             t1->fib_index = vec_elt (im->mfib_index_by_sw_if_index,
  84                                      vnet_buffer(b1)->sw_if_index[VLIB_RX]);
  85         }
  86         from += 2;
  87         n_left -= 2;
  88     }
  89
  90     while (n_left >= 1)
  91     {
  92         mfib_forward_lookup_trace_t * t0;
  93         vlib_buffer_t * b0;
  94         u32 bi0;
  95
  96         bi0 = from[0];
  97
  98         b0 = vlib_get_buffer (vm, bi0);
  99
 100         if (b0->flags & VLIB_BUFFER_IS_TRACED)
 101         {
 102             t0 = vlib_add_trace (vm, node, b0, sizeof (t0[0]));
 103             t0->entry_index = vnet_buffer (b0)->ip.adj_index[VLIB_TX];
 104             t0->fib_index = vec_elt (im->mfib_index_by_sw_if_index,
 105                                      vnet_buffer(b0)->sw_if_index[VLIB_RX]);
 106         }
 107         from += 1;
 108         n_left -= 1;
 109     }
 110 }
 111
 112 typedef enum mfib_forward_lookup_next_t_ {
 113     MFIB_FORWARD_LOOKUP_NEXT_RPF,
 114     MFIB_FORWARD_LOOKUP_N_NEXT,
 115 } mfib_forward_lookup_next_t;
 116
 117 static uword
 118 mfib_forward_lookup (vlib_main_t * vm,
 119                      vlib_node_runtime_t * node,
 120                      vlib_frame_t * frame,
 121                      int is_v4)
 122 {
 123     u32 n_left_from, n_left_to_next, * from, * to_next;
 124
 125     from = vlib_frame_vector_args (frame);
 126     n_left_from = frame->n_vectors;
 127
 128     while (n_left_from > 0)
 129     {
 130         vlib_get_next_frame (vm, node, MFIB_FORWARD_LOOKUP_NEXT_RPF,
 131                              to_next, n_left_to_next);
 132
 133         while (n_left_from > 0 && n_left_to_next > 0)
 134         {
 135             fib_node_index_t mfei0;
 136             vlib_buffer_t * p0;
 137             u32 fib_index0;
 138             u32 pi0;
 139
 140             pi0 = from[0];
 141             to_next[0] = pi0;
 142             from += 1;
 143             to_next += 1;
 144             n_left_to_next -= 1;
 145             n_left_from -= 1;
 146
 147             p0 = vlib_get_buffer (vm, pi0);
 148
 149             if (is_v4)
 150             {
 151                 ip4_header_t * ip0;
 152
 153                 fib_index0 = vec_elt (ip4_main.mfib_index_by_sw_if_index,
 154                                       vnet_buffer(p0)->sw_if_index[VLIB_RX]);
 155                 ip0 = vlib_buffer_get_current (p0);
 156                 mfei0 = ip4_mfib_table_lookup(ip4_mfib_get(fib_index0),
 157                                               &ip0->src_address,
 158                                               &ip0->dst_address,
 159                                               64);
 160             }
 161             else
 162             {
 163                 ip6_header_t * ip0;
 164
 165                 fib_index0 = vec_elt (ip6_main.mfib_index_by_sw_if_index,
 166                                       vnet_buffer(p0)->sw_if_index[VLIB_RX]);
 167                 ip0 = vlib_buffer_get_current (p0);
 168                 mfei0 = ip6_mfib_table_lookup2(ip6_mfib_get(fib_index0),
 169                                                &ip0->src_address,
 170                                                &ip0->dst_address);
 171             }
 172
 173             vnet_buffer (p0)->ip.adj_index[VLIB_TX] = mfei0;
 174         }
 175
 176         vlib_put_next_frame(vm, node,
 177                             MFIB_FORWARD_LOOKUP_NEXT_RPF,
 178                             n_left_to_next);
 179     }
 180
 181     if (node->flags & VLIB_NODE_FLAG_TRACE)
 182         mfib_forward_lookup_trace(vm, node, frame);
 183
 184     return frame->n_vectors;
 185 }
 186
 187 static uword
 188 ip4_mfib_forward_lookup (vlib_main_t * vm,
 189                          vlib_node_runtime_t * node,
 190                          vlib_frame_t * frame)
 191 {
 192     return (mfib_forward_lookup (vm, node, frame, 1));
 193 }
 194
 195 VLIB_REGISTER_NODE (ip4_mfib_forward_lookup_node, static) = {
 196     .function = ip4_mfib_forward_lookup,
 197     .name = "ip4-mfib-forward-lookup",
 198     .vector_size = sizeof (u32),
 199
 200     .format_trace = format_mfib_forward_lookup_trace,
 201
 202     .n_next_nodes = MFIB_FORWARD_LOOKUP_N_NEXT,
 203     .next_nodes = {
 204         [MFIB_FORWARD_LOOKUP_NEXT_RPF] = "ip4-mfib-forward-rpf",
 205     },
 206 };
 207
 208 VLIB_NODE_FUNCTION_MULTIARCH (ip4_mfib_forward_lookup_node,
 209                               ip4_mfib_forward_lookup)
 210
 211 static uword
 212 ip6_mfib_forward_lookup (vlib_main_t * vm,
 213                          vlib_node_runtime_t * node,
 214                          vlib_frame_t * frame)
 215 {
 216     return (mfib_forward_lookup (vm, node, frame, 0));
 217 }
 218
 219 VLIB_REGISTER_NODE (ip6_mfib_forward_lookup_node, static) = {
 220     .function = ip6_mfib_forward_lookup,
 221     .name = "ip6-mfib-forward-lookup",
 222     .vector_size = sizeof (u32),
 223
 224     .format_trace = format_mfib_forward_lookup_trace,
 225
 226     .n_next_nodes = MFIB_FORWARD_LOOKUP_N_NEXT,
 227     .next_nodes = {
 228         [MFIB_FORWARD_LOOKUP_NEXT_RPF] = "ip6-mfib-forward-rpf",
 229     },
 230 };
 231
 232 VLIB_NODE_FUNCTION_MULTIARCH (ip6_mfib_forward_lookup_node,
 233                               ip6_mfib_forward_lookup)
 234
 235
 236 typedef struct mfib_forward_rpf_trace_t_ {
 237     u32 entry_index;
 238     u32 sw_if_index;
 239     mfib_itf_flags_t itf_flags;
 240 } mfib_forward_rpf_trace_t;
 241
 242 typedef enum mfib_forward_rpf_next_t_ {
 243     MFIB_FORWARD_RPF_NEXT_DROP,
 244     MFIB_FORWARD_RPF_N_NEXT,
 245 } mfib_forward_rpf_next_t;
 246
 247 static u8 *
 248 format_mfib_forward_rpf_trace (u8 * s, va_list * args)
 249 {
 250     CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 251     CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 252     mfib_forward_rpf_trace_t * t = va_arg (*args, mfib_forward_rpf_trace_t *);
 253
 254     s = format (s, "entry %d", t->entry_index);
 255     s = format (s, " itf %d", t->sw_if_index);
 256     s = format (s, " flags %U", format_mfib_itf_flags, t->itf_flags);
 257
 258     return s;
 259 }
 260
 261 static int
 262 mfib_forward_connected_check (vlib_buffer_t * b0,
 263                               u32 sw_if_index,
 264                               int is_v4)
 265 {
 266     /*
 267      * Lookup the source of the IP packet in the
 268      * FIB. return true if the entry is attached.
 269      */
 270     index_t lbi0;
 271
 272     if (is_v4)
 273     {
 274         load_balance_t *lb0;
 275         ip4_header_t *ip0;
 276
 277         ip0 = vlib_buffer_get_current(b0);
 278
 279         lbi0 = ip4_fib_forwarding_lookup(
 280                    ip4_fib_table_get_index_for_sw_if_index(
 281                        sw_if_index),
 282                    &ip0->src_address);
 283         lb0 = load_balance_get(lbi0);
 284
 285         return (FIB_ENTRY_FLAG_ATTACHED &
 286                 lb0->lb_fib_entry_flags);
 287     }
 288     else
 289     {
 290         ASSERT(0);
 291     }
 292     return (0);
 293 }
 294
 295 static void
 296 mfib_forward_itf_signal (vlib_main_t *vm,
 297                          const mfib_entry_t *mfe,
 298                          mfib_itf_t *mfi,
 299                          vlib_buffer_t *b0)
 300 {
 301     mfib_itf_flags_t old_flags;
 302
 303     old_flags = __sync_fetch_and_or(&mfi->mfi_flags,
 304                                     MFIB_ITF_FLAG_SIGNAL_PRESENT);
 305
 306     if (!(old_flags & MFIB_ITF_FLAG_SIGNAL_PRESENT))
 307     {
 308         /*
 309          * we were the lucky ones to set the signal present flag
 310          */
 311         if (!(old_flags & MFIB_ITF_FLAG_DONT_PRESERVE))
 312         {
 313             /*
 314              * preserve a copy of the packet for the control
 315              * plane to examine.
 316              * Only allow one preserved packet at at time, since
 317              * when the signal present flag is cleared so is the
 318              * preserved packet.
 319              */
 320             mfib_signal_push(mfe, mfi, b0);
 321         }
 322         else
 323         {
 324             /*
 325              *  The control plane just wants the signal, not the packet as well
 326              */
 327             mfib_signal_push(mfe, mfi, NULL);
 328         }
 329     }
 330     /*
 331      * else
 332      *   there is already a signal present on this interface that the
 333      *   control plane has not yet acknowledged
 334      */
 335 }
 336
 337 always_inline uword
 338 mfib_forward_rpf (vlib_main_t * vm,
 339                   vlib_node_runtime_t * node,
 340                   vlib_frame_t * frame,
 341                   int is_v4)
 342 {
 343     u32 n_left_from, n_left_to_next, * from, * to_next;
 344     mfib_forward_rpf_next_t next;
 345     vlib_node_runtime_t *error_node;
 346
 347     if (is_v4)
 348         error_node = vlib_node_get_runtime (vm, ip4_input_node.index);
 349     else
 350         error_node = vlib_node_get_runtime (vm, ip6_input_node.index);
 351     from = vlib_frame_vector_args (frame);
 352     n_left_from = frame->n_vectors;
 353     next = MFIB_FORWARD_RPF_NEXT_DROP;
 354
 355     while (n_left_from > 0)
 356     {
 357         vlib_get_next_frame (vm, node, next,
 358                              to_next, n_left_to_next);
 359
 360         while (n_left_from > 0 && n_left_to_next > 0)
 361         {
 362             fib_node_index_t mfei0;
 363             const mfib_entry_t *mfe0;
 364             mfib_itf_t *mfi0;
 365             vlib_buffer_t * b0;
 366             u32 pi0, next0;
 367             mfib_itf_flags_t iflags0;
 368             mfib_entry_flags_t eflags0;
 369             u8 error0;
 370
 371             pi0 = from[0];
 372             to_next[0] = pi0;
 373             from += 1;
 374             to_next += 1;
 375             n_left_to_next -= 1;
 376             n_left_from -= 1;
 377
 378             error0 = IP4_ERROR_NONE;
 379             b0 = vlib_get_buffer (vm, pi0);
 380             mfei0 = vnet_buffer (b0)->ip.adj_index[VLIB_TX];
 381             mfe0 = mfib_entry_get(mfei0);
 382             mfi0 = mfib_entry_get_itf(mfe0,
 383                                       vnet_buffer(b0)->sw_if_index[VLIB_RX]);
 384
 385             /*
 386              * throughout this function we are 'PREDICT' optimising
 387              * for the case of throughput traffic that is not replicated
 388              * to the host stack nor sets local flags
 389              */
 390
 391             /*
 392              * If the mfib entry has a configured RPF-ID check that
 393              * in preference to an interface based RPF
 394              */
 395             if (MFIB_RPF_ID_NONE != mfe0->mfe_rpf_id)
 396             {
 397                 iflags0 = (mfe0->mfe_rpf_id == vnet_buffer(b0)->ip.rpf_id ?
 398                            MFIB_ITF_FLAG_ACCEPT :
 399                            MFIB_ITF_FLAG_NONE);
 400             }
 401             else
 402             {
 403                 if (PREDICT_TRUE(NULL != mfi0))
 404                 {
 405                     iflags0 = mfi0->mfi_flags;
 406                 }
 407                 else
 408                 {
 409                     iflags0 = MFIB_ITF_FLAG_NONE;
 410                 }
 411             }
 412             eflags0 = mfe0->mfe_flags;
 413
 414             if (PREDICT_FALSE(eflags0 & MFIB_ENTRY_FLAG_CONNECTED))
 415             {
 416                 /*
 417                  * lookup the source in the unicast FIB - check it
 418                  * matches a connected.
 419                  */
 420                 if (mfib_forward_connected_check(
 421                         b0,
 422                         vnet_buffer(b0)->sw_if_index[VLIB_RX],
 423                         is_v4))
 424                 {
 425                     mfib_forward_itf_signal(vm, mfe0, mfi0, b0);
 426                 }
 427             }
 428             if (PREDICT_FALSE((eflags0 & MFIB_ENTRY_FLAG_SIGNAL) ^
 429                               (iflags0 & MFIB_ITF_FLAG_NEGATE_SIGNAL)))
 430             {
 431                 /*
 432                  * Entry signal XOR interface negate-signal
 433                  */
 434                 if (NULL != mfi0)
 435                 {
 436                     mfib_forward_itf_signal(vm, mfe0, mfi0, b0);
 437                 }
 438             }
 439
 440             if (PREDICT_TRUE((iflags0 & MFIB_ITF_FLAG_ACCEPT) ||
 441                              (eflags0 & MFIB_ENTRY_FLAG_ACCEPT_ALL_ITF)))
 442             {
 443                 /*
 444                  * This interface is accepting packets for the matching entry
 445                  */
 446                 next0 = mfe0->mfe_rep.dpoi_next_node;
 447
 448                 vnet_buffer(b0)->ip.adj_index[VLIB_TX] =
 449                     mfe0->mfe_rep.dpoi_index;
 450             }
 451             else
 452             {
 453                 next0 = MFIB_FORWARD_RPF_NEXT_DROP;
 454                 error0 = IP4_ERROR_RPF_FAILURE;
 455             }
 456
 457             b0->error = error0 ? error_node->errors[error0] : 0;
 458
 459             if (b0->flags & VLIB_BUFFER_IS_TRACED)
 460             {
 461                 mfib_forward_rpf_trace_t *t0;
 462
 463                 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
 464                 t0->entry_index = mfei0;
 465                 t0->itf_flags = iflags0;
 466                 if (NULL == mfi0)
 467                 {
 468                     t0->sw_if_index = ~0;
 469                 }
 470                 else
 471                 {
 472                     t0->sw_if_index = mfi0->mfi_sw_if_index;
 473                 }
 474             }
 475             vlib_validate_buffer_enqueue_x1 (vm, node, next,
 476                                              to_next, n_left_to_next,
 477                                              pi0, next0);
 478         }
 479
 480         vlib_put_next_frame(vm, node, next, n_left_to_next);
 481     }
 482
 483     return frame->n_vectors;
 484 }
 485
 486 static uword
 487 ip4_mfib_forward_rpf (vlib_main_t * vm,
 488                       vlib_node_runtime_t * node,
 489                       vlib_frame_t * frame)
 490 {
 491     return (mfib_forward_rpf(vm, node, frame, 1));
 492 }
 493
 494
 495 VLIB_REGISTER_NODE (ip4_mfib_forward_rpf_node, static) = {
 496     .function = ip4_mfib_forward_rpf,
 497     .name = "ip4-mfib-forward-rpf",
 498     .vector_size = sizeof (u32),
 499
 500     .format_trace = format_mfib_forward_rpf_trace,
 501
 502     .n_next_nodes = MFIB_FORWARD_RPF_N_NEXT,
 503     .next_nodes = {
 504         [MFIB_FORWARD_RPF_NEXT_DROP] = "ip4-drop",
 505     },
 506 };
 507
 508 VLIB_NODE_FUNCTION_MULTIARCH (ip4_mfib_forward_rpf_node,
 509                               ip4_mfib_forward_rpf)
 510
 511 static uword
 512 ip6_mfib_forward_rpf (vlib_main_t * vm,
 513                       vlib_node_runtime_t * node,
 514                       vlib_frame_t * frame)
 515 {
 516     return (mfib_forward_rpf(vm, node, frame, 1));
 517 }
 518
 519
 520 VLIB_REGISTER_NODE (ip6_mfib_forward_rpf_node, static) = {
 521     .function = ip6_mfib_forward_rpf,
 522     .name = "ip6-mfib-forward-rpf",
 523     .vector_size = sizeof (u32),
 524
 525     .format_trace = format_mfib_forward_rpf_trace,
 526
 527     .n_next_nodes = MFIB_FORWARD_RPF_N_NEXT,
 528     .next_nodes = {
 529         [MFIB_FORWARD_RPF_NEXT_DROP] = "ip6-drop",
 530     },
 531 };
 532
 533 VLIB_NODE_FUNCTION_MULTIARCH (ip6_mfib_forward_rpf_node,
 534                               ip6_mfib_forward_rpf)
 535