src/vnet/sr/sr_replicate.c

   1 /*
   2  * sr_replicate.c: ipv6 segment routing replicator for multicast
   3  *
   4  * Copyright (c) 2016 Cisco and/or its affiliates.
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at:
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17 /**
  18  *  @file
  19  *  @brief Functions for replicating packets across SR tunnels.
  20  *
  21  *  Leverages rte_pktmbuf_clone() so there is no memcpy for
  22  *  invariant parts of the packet.
  23  *
  24  *  @note Currently requires DPDK
  25 */
  26
  27 #if DPDK > 0                    /* Cannot run replicate without DPDK */
  28 #include <vlib/vlib.h>
  29 #include <vnet/vnet.h>
  30 #include <vnet/pg/pg.h>
  31 #include <vnet/sr/sr.h>
  32 #include <vnet/devices/dpdk/dpdk.h>
  33 #include <vnet/ip/ip.h>
  34 #include <vnet/fib/ip6_fib.h>
  35
  36 #include <vppinfra/hash.h>
  37 #include <vppinfra/error.h>
  38 #include <vppinfra/elog.h>
  39
  40 /**
  41  *   @brief sr_replicate state.
  42  *
  43 */
  44 typedef struct
  45 {
  46   /* convenience */
  47   vlib_main_t *vlib_main;
  48   vnet_main_t *vnet_main;
  49 } sr_replicate_main_t;
  50
  51 sr_replicate_main_t sr_replicate_main;
  52
  53 /**
  54  *    @brief Information to display in packet trace.
  55  *
  56 */
  57 typedef struct
  58 {
  59   ip6_address_t src, dst;
  60   u16 length;
  61   u32 next_index;
  62   u32 tunnel_index;
  63   u8 sr[256];
  64 } sr_replicate_trace_t;
  65
  66 /**
  67  *  @brief packet trace format function.
  68  *
  69  *  @param *s u8 used for string output
  70  *  @param *args va_list  structured input to va_arg to output @ref sr_replicate_trace_t
  71  *  @return *s u8 - formatted trace output
  72 */
  73 static u8 *
  74 format_sr_replicate_trace (u8 * s, va_list * args)
  75 {
  76   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  77   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  78   sr_replicate_trace_t *t = va_arg (*args, sr_replicate_trace_t *);
  79   ip6_sr_main_t *sm = &sr_main;
  80   ip6_sr_tunnel_t *tun = pool_elt_at_index (sm->tunnels, t->tunnel_index);
  81   ip6_fib_t *rx_fib, *tx_fib;
  82
  83   rx_fib = ip6_fib_get (tun->rx_fib_index);
  84   tx_fib = ip6_fib_get (tun->tx_fib_index);
  85
  86   s = format
  87     (s, "SR-REPLICATE: next %s ip6 src %U dst %U len %u\n"
  88      "           rx-fib-id %d tx-fib-id %d\n%U",
  89      "ip6-lookup",
  90      format_ip6_address, &t->src,
  91      format_ip6_address, &t->dst, t->length,
  92      rx_fib->table_id, tx_fib->table_id,
  93      format_ip6_sr_header, t->sr, 0 /* print_hmac */ );
  94   return s;
  95
  96 }
  97
  98 #define foreach_sr_replicate_error \
  99 _(REPLICATED, "sr packets replicated") \
 100 _(NO_BUFFERS, "error allocating buffers for replicas") \
 101 _(NO_REPLICAS, "no replicas were needed") \
 102 _(NO_BUFFER_DROPS, "sr no buffer drops")
 103
 104 /**
 105  * @brief Struct for SR replicate errors
 106  */
 107 typedef enum
 108 {
 109 #define _(sym,str) SR_REPLICATE_ERROR_##sym,
 110   foreach_sr_replicate_error
 111 #undef _
 112     SR_REPLICATE_N_ERROR,
 113 } sr_replicate_error_t;
 114
 115 /**
 116  * @brief Error strings for SR replicate
 117  */
 118 static char *sr_replicate_error_strings[] = {
 119 #define _(sym,string) string,
 120   foreach_sr_replicate_error
 121 #undef _
 122 };
 123
 124 /**
 125  * @brief Defines next-nodes for packet processing.
 126  *
 127 */
 128 typedef enum
 129 {
 130   SR_REPLICATE_NEXT_IP6_LOOKUP,
 131   SR_REPLICATE_N_NEXT,
 132 } sr_replicate_next_t;
 133
 134 /**
 135  *   @brief Single loop packet replicator.
 136  *
 137  *   @node sr-replicate
 138  *   @param vm vlib_main_t
 139  *   @return frame->n_vectors uword
 140 */
 141 static uword
 142 sr_replicate_node_fn (vlib_main_t * vm,
 143                       vlib_node_runtime_t * node, vlib_frame_t * frame)
 144 {
 145   u32 n_left_from, *from, *to_next;
 146   sr_replicate_next_t next_index;
 147   int pkts_replicated = 0;
 148   ip6_sr_main_t *sm = &sr_main;
 149   int no_buffer_drops = 0;
 150   vlib_buffer_free_list_t *fl;
 151   unsigned socket_id = rte_socket_id ();
 152   vlib_buffer_main_t *bm = vm->buffer_main;
 153
 154   from = vlib_frame_vector_args (frame);
 155   n_left_from = frame->n_vectors;
 156   next_index = node->cached_next_index;
 157
 158   fl = vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
 159
 160   while (n_left_from > 0)
 161     {
 162       u32 n_left_to_next;
 163
 164       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 165
 166       while (n_left_from > 0 && n_left_to_next > 0)
 167         {
 168           u32 bi0, hdr_bi0;
 169           vlib_buffer_t *b0, *orig_b0;
 170           struct rte_mbuf *orig_mb0 = 0, *hdr_mb0 = 0, *clone0 = 0;
 171           struct rte_mbuf **hdr_vec = 0, **rte_mbuf_vec = 0;
 172           ip6_sr_policy_t *pol0 = 0;
 173           ip6_sr_tunnel_t *t0 = 0;
 174           ip6_sr_header_t *hdr_sr0 = 0;
 175           ip6_header_t *ip0 = 0, *hdr_ip0 = 0;
 176           int num_replicas = 0;
 177           int i;
 178           u32 len_bytes = sizeof (ip6_header_t);
 179           u8 next_hdr, ip_next_hdr = IPPROTO_IPV6_ROUTE;
 180
 181           bi0 = from[0];
 182
 183           b0 = vlib_get_buffer (vm, bi0);
 184           orig_b0 = b0;
 185
 186           pol0 = pool_elt_at_index (sm->policies,
 187                                     vnet_buffer (b0)->ip.save_protocol);
 188
 189           ip0 = vlib_buffer_get_current (b0);
 190           /* Skip forward to the punch-in point */
 191           vlib_buffer_advance (b0, sizeof (*ip0));
 192           next_hdr = ip0->protocol;
 193
 194           /* HBH must immediately follow ipv6 header */
 195           if (PREDICT_FALSE
 196               (ip0->protocol == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS))
 197             {
 198               ip6_hop_by_hop_ext_t *ext_hdr =
 199                 (ip6_hop_by_hop_ext_t *) ip6_next_header (ip0);
 200               u32 ext_hdr_len = 0;
 201               ext_hdr_len = ip6_ext_header_len ((ip6_ext_header_t *) ext_hdr);
 202               len_bytes += ext_hdr_len;
 203               next_hdr = ext_hdr->next_hdr;
 204               ext_hdr->next_hdr = IPPROTO_IPV6_ROUTE;
 205               ip_next_hdr = IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS;
 206               /* Skip forward to the punch-in point */
 207               vlib_buffer_advance (b0, ext_hdr_len);
 208
 209             }
 210
 211           orig_mb0 = rte_mbuf_from_vlib_buffer (b0);
 212
 213           i16 delta0 = vlib_buffer_length_in_chain (vm, orig_b0)
 214             - (i16) orig_mb0->pkt_len;
 215
 216           u16 new_data_len0 = (u16) ((i16) orig_mb0->data_len + delta0);
 217           u16 new_pkt_len0 = (u16) ((i16) orig_mb0->pkt_len + delta0);
 218
 219           orig_mb0->data_len = new_data_len0;
 220           orig_mb0->pkt_len = new_pkt_len0;
 221           orig_mb0->data_off += (u16) (b0->current_data);
 222
 223           /*
 224              Before entering loop determine if we can allocate:
 225              - all the new HEADER RTE_MBUFs and assign them to a vector
 226              - all the clones
 227
 228              if successful, then iterate over vectors of resources
 229
 230            */
 231           num_replicas = vec_len (pol0->tunnel_indices);
 232
 233           if (PREDICT_FALSE (num_replicas == 0))
 234             {
 235               b0->error = node->errors[SR_REPLICATE_ERROR_NO_REPLICAS];
 236               goto do_trace0;
 237             }
 238
 239           vec_reset_length (hdr_vec);
 240           vec_reset_length (rte_mbuf_vec);
 241
 242           for (i = 0; i < num_replicas; i++)
 243             {
 244               uint8_t nb_seg;
 245               struct rte_mbuf *clone0i;
 246               vlib_buffer_t *clone0_c, *clone_b0;
 247
 248               t0 = vec_elt_at_index (sm->tunnels, pol0->tunnel_indices[i]);
 249               hdr_mb0 = rte_pktmbuf_alloc (bm->pktmbuf_pools[socket_id]);
 250
 251               if (i < (num_replicas - 1))
 252                 {
 253                   /* Not the last tunnel to process */
 254                   clone0 = rte_pktmbuf_clone
 255                     (orig_mb0, bm->pktmbuf_pools[socket_id]);
 256                   if (clone0 == 0)
 257                     goto clone_fail;
 258                   nb_seg = 0;
 259                   clone0i = clone0;
 260                   clone0_c = NULL;
 261                   while ((clone0->nb_segs >= 1) && (nb_seg < clone0->nb_segs))
 262                     {
 263
 264                       clone_b0 = vlib_buffer_from_rte_mbuf (clone0i);
 265                       vlib_buffer_init_for_free_list (clone_b0, fl);
 266
 267                       ASSERT ((clone_b0->flags & VLIB_BUFFER_NEXT_PRESENT) ==
 268                               0);
 269                       ASSERT (clone_b0->current_data == 0);
 270
 271                       clone_b0->current_data =
 272                         (clone0i->buf_addr + clone0i->data_off) -
 273                         (void *) clone_b0->data;
 274
 275                       clone_b0->current_length = clone0i->data_len;
 276                       if (PREDICT_FALSE (clone0_c != NULL))
 277                         {
 278                           clone0_c->flags |= VLIB_BUFFER_NEXT_PRESENT;
 279                           clone0_c->next_buffer =
 280                             vlib_get_buffer_index (vm, clone_b0);
 281                         }
 282                       clone0_c = clone_b0;
 283                       clone0i = clone0i->next;
 284                       nb_seg++;
 285                     }
 286                 }
 287               else
 288                 /* First tunnel to process, use original MB */
 289                 clone0 = orig_mb0;
 290
 291
 292               if (PREDICT_FALSE (!clone0 || !hdr_mb0))
 293                 {
 294                 clone_fail:
 295                   b0->error = node->errors[SR_REPLICATE_ERROR_NO_BUFFERS];
 296
 297                   vec_foreach_index (i, rte_mbuf_vec)
 298                   {
 299                     rte_pktmbuf_free (rte_mbuf_vec[i]);
 300                   }
 301                   vec_free (rte_mbuf_vec);
 302
 303                   vec_foreach_index (i, hdr_vec)
 304                   {
 305                     rte_pktmbuf_free (hdr_vec[i]);
 306                   }
 307                   vec_free (hdr_vec);
 308
 309                   goto do_trace0;
 310                 }
 311
 312               vec_add1 (hdr_vec, hdr_mb0);
 313               vec_add1 (rte_mbuf_vec, clone0);
 314
 315             }
 316
 317           for (i = 0; i < num_replicas; i++)
 318             {
 319               vlib_buffer_t *hdr_b0;
 320               u16 new_l0 = 0;
 321
 322               t0 = vec_elt_at_index (sm->tunnels, pol0->tunnel_indices[i]);
 323               /* Our replicas */
 324               hdr_mb0 = hdr_vec[i];
 325               clone0 = rte_mbuf_vec[i];
 326
 327               hdr_mb0->data_len = len_bytes + vec_len (t0->rewrite);
 328               hdr_mb0->pkt_len = hdr_mb0->data_len +
 329                 vlib_buffer_length_in_chain (vm, orig_b0);
 330
 331               hdr_b0 = vlib_buffer_from_rte_mbuf (hdr_mb0);
 332
 333               vlib_buffer_init_for_free_list (hdr_b0, fl);
 334
 335               memcpy (hdr_b0->data, ip0, len_bytes);
 336               memcpy (hdr_b0->data + len_bytes, t0->rewrite,
 337                       vec_len (t0->rewrite));
 338
 339               hdr_b0->current_data = 0;
 340               hdr_b0->current_length = len_bytes + vec_len (t0->rewrite);
 341               hdr_b0->flags = orig_b0->flags | VLIB_BUFFER_NEXT_PRESENT;
 342               hdr_b0->trace_index = orig_b0->trace_index;
 343               vnet_buffer (hdr_b0)->l2_classify.opaque_index = 0;
 344
 345               hdr_b0->total_length_not_including_first_buffer =
 346                 hdr_mb0->pkt_len - hdr_b0->current_length;
 347               vnet_buffer (hdr_b0)->sw_if_index[VLIB_TX] = t0->tx_fib_index;
 348
 349               hdr_ip0 = (ip6_header_t *) hdr_b0->data;
 350               new_l0 = clib_net_to_host_u16 (ip0->payload_length) +
 351                 vec_len (t0->rewrite);
 352               hdr_ip0->payload_length = clib_host_to_net_u16 (new_l0);
 353               hdr_sr0 = (ip6_sr_header_t *) ((u8 *) hdr_ip0 + len_bytes);
 354               /* $$$ tune */
 355               clib_memcpy (hdr_sr0, t0->rewrite, vec_len (t0->rewrite));
 356               hdr_sr0->protocol = next_hdr;
 357               hdr_ip0->protocol = ip_next_hdr;
 358
 359               /* Copy dst address into the DA slot in the segment list */
 360               clib_memcpy (hdr_sr0->segments, ip0->dst_address.as_u64,
 361                            sizeof (ip6_address_t));
 362
 363               /* Rewrite the ip6 dst address */
 364               hdr_ip0->dst_address.as_u64[0] = t0->first_hop.as_u64[0];
 365               hdr_ip0->dst_address.as_u64[1] = t0->first_hop.as_u64[1];
 366
 367               sr_fix_hmac (sm, hdr_ip0, hdr_sr0);
 368
 369               /* prepend new header to invariant piece */
 370               hdr_mb0->next = clone0;
 371               hdr_b0->next_buffer =
 372                 vlib_get_buffer_index (vm,
 373                                        vlib_buffer_from_rte_mbuf (clone0));
 374
 375               /* update header's fields */
 376               hdr_mb0->pkt_len =
 377                 (uint16_t) (hdr_mb0->data_len + clone0->pkt_len);
 378               hdr_mb0->nb_segs = (uint8_t) (clone0->nb_segs + 1);
 379
 380               /* copy metadata from source packet */
 381               hdr_mb0->port = clone0->port;
 382               hdr_mb0->vlan_tci = clone0->vlan_tci;
 383               hdr_mb0->vlan_tci_outer = clone0->vlan_tci_outer;
 384               hdr_mb0->tx_offload = clone0->tx_offload;
 385               hdr_mb0->hash = clone0->hash;
 386
 387               hdr_mb0->ol_flags = clone0->ol_flags & ~(IND_ATTACHED_MBUF);
 388
 389               __rte_mbuf_sanity_check (hdr_mb0, 1);
 390
 391               hdr_bi0 = vlib_get_buffer_index (vm, hdr_b0);
 392
 393               to_next[0] = hdr_bi0;
 394               to_next += 1;
 395               n_left_to_next -= 1;
 396
 397               if (n_left_to_next == 0)
 398                 {
 399                   vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 400                   vlib_get_next_frame (vm, node, next_index,
 401                                        to_next, n_left_to_next);
 402
 403                 }
 404               pkts_replicated++;
 405             }
 406
 407           from += 1;
 408           n_left_from -= 1;
 409
 410         do_trace0:
 411           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 412             {
 413               sr_replicate_trace_t *tr = vlib_add_trace (vm, node,
 414                                                          b0, sizeof (*tr));
 415               tr->tunnel_index = t0 - sm->tunnels;
 416               tr->length = 0;
 417               if (hdr_ip0)
 418                 {
 419                   memcpy (tr->src.as_u8, hdr_ip0->src_address.as_u8,
 420                           sizeof (tr->src.as_u8));
 421                   memcpy (tr->dst.as_u8, hdr_ip0->dst_address.as_u8,
 422                           sizeof (tr->dst.as_u8));
 423                   if (hdr_ip0->payload_length)
 424                     tr->length = clib_net_to_host_u16
 425                       (hdr_ip0->payload_length);
 426                 }
 427               tr->next_index = next_index;
 428               if (hdr_sr0)
 429                 memcpy (tr->sr, hdr_sr0, sizeof (tr->sr));
 430             }
 431
 432         }
 433
 434       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 435     }
 436
 437   vlib_node_increment_counter (vm, sr_replicate_node.index,
 438                                SR_REPLICATE_ERROR_REPLICATED,
 439                                pkts_replicated);
 440
 441   vlib_node_increment_counter (vm, sr_replicate_node.index,
 442                                SR_REPLICATE_ERROR_NO_BUFFER_DROPS,
 443                                no_buffer_drops);
 444
 445   return frame->n_vectors;
 446 }
 447
 448 /* *INDENT-OFF* */
 449 VLIB_REGISTER_NODE (sr_replicate_node) = {
 450   .function = sr_replicate_node_fn,
 451   .name = "sr-replicate",
 452   .vector_size = sizeof (u32),
 453   .format_trace = format_sr_replicate_trace,
 454   .type = VLIB_NODE_TYPE_INTERNAL,
 455
 456   .n_errors = ARRAY_LEN(sr_replicate_error_strings),
 457   .error_strings = sr_replicate_error_strings,
 458
 459   .n_next_nodes = SR_REPLICATE_N_NEXT,
 460
 461   .next_nodes = {
 462         [SR_REPLICATE_NEXT_IP6_LOOKUP] = "ip6-lookup",
 463   },
 464 };
 465
 466 VLIB_NODE_FUNCTION_MULTIARCH (sr_replicate_node, sr_replicate_node_fn)
 467 /* *INDENT-ON* */
 468
 469 clib_error_t *
 470 sr_replicate_init (vlib_main_t * vm)
 471 {
 472   sr_replicate_main_t *msm = &sr_replicate_main;
 473
 474   msm->vlib_main = vm;
 475   msm->vnet_main = vnet_get_main ();
 476
 477   return 0;
 478 }
 479
 480 VLIB_INIT_FUNCTION (sr_replicate_init);
 481
 482 #endif /* DPDK */
 483
 484 /*
 485  * fd.io coding-style-patch-verification: ON
 486  *
 487  * Local Variables:
 488  * eval: (c-set-style "gnu")
 489  * End:
 490  */