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/devices/dpdk/dpdk_priv.h>
  34 #include <vnet/ip/ip.h>
  35 #include <vnet/fib/ip6_fib.h>
  36
  37 #include <vppinfra/hash.h>
  38 #include <vppinfra/error.h>
  39 #include <vppinfra/elog.h>
  40
  41 /**
  42  *   @brief sr_replicate state.
  43  *
  44 */
  45 typedef struct
  46 {
  47   /* convenience */
  48   vlib_main_t *vlib_main;
  49   vnet_main_t *vnet_main;
  50 } sr_replicate_main_t;
  51
  52 sr_replicate_main_t sr_replicate_main;
  53
  54 /**
  55  *    @brief Information to display in packet trace.
  56  *
  57 */
  58 typedef struct
  59 {
  60   ip6_address_t src, dst;
  61   u16 length;
  62   u32 next_index;
  63   u32 tunnel_index;
  64   u8 sr[256];
  65 } sr_replicate_trace_t;
  66
  67 /**
  68  *  @brief packet trace format function.
  69  *
  70  *  @param *s u8 used for string output
  71  *  @param *args va_list  structured input to va_arg to output @ref sr_replicate_trace_t
  72  *  @return *s u8 - formatted trace output
  73 */
  74 static u8 *
  75 format_sr_replicate_trace (u8 * s, va_list * args)
  76 {
  77   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  78   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  79   sr_replicate_trace_t *t = va_arg (*args, sr_replicate_trace_t *);
  80   ip6_sr_main_t *sm = &sr_main;
  81   ip6_sr_tunnel_t *tun = pool_elt_at_index (sm->tunnels, t->tunnel_index);
  82   ip6_fib_t *rx_fib, *tx_fib;
  83
  84   rx_fib = ip6_fib_get (tun->rx_fib_index);
  85   tx_fib = ip6_fib_get (tun->tx_fib_index);
  86
  87   s = format
  88     (s, "SR-REPLICATE: next %s ip6 src %U dst %U len %u\n"
  89      "           rx-fib-id %d tx-fib-id %d\n%U",
  90      "ip6-lookup",
  91      format_ip6_address, &t->src,
  92      format_ip6_address, &t->dst, t->length,
  93      rx_fib->table_id, tx_fib->table_id,
  94      format_ip6_sr_header, t->sr, 0 /* print_hmac */ );
  95   return s;
  96
  97 }
  98
  99 #define foreach_sr_replicate_error \
 100 _(REPLICATED, "sr packets replicated") \
 101 _(NO_BUFFERS, "error allocating buffers for replicas") \
 102 _(NO_REPLICAS, "no replicas were needed") \
 103 _(NO_BUFFER_DROPS, "sr no buffer drops")
 104
 105 /**
 106  * @brief Struct for SR replicate errors
 107  */
 108 typedef enum
 109 {
 110 #define _(sym,str) SR_REPLICATE_ERROR_##sym,
 111   foreach_sr_replicate_error
 112 #undef _
 113     SR_REPLICATE_N_ERROR,
 114 } sr_replicate_error_t;
 115
 116 /**
 117  * @brief Error strings for SR replicate
 118  */
 119 static char *sr_replicate_error_strings[] = {
 120 #define _(sym,string) string,
 121   foreach_sr_replicate_error
 122 #undef _
 123 };
 124
 125 /**
 126  * @brief Defines next-nodes for packet processing.
 127  *
 128 */
 129 typedef enum
 130 {
 131   SR_REPLICATE_NEXT_IP6_LOOKUP,
 132   SR_REPLICATE_N_NEXT,
 133 } sr_replicate_next_t;
 134
 135 /**
 136  *   @brief Single loop packet replicator.
 137  *
 138  *   @node sr-replicate
 139  *   @param vm vlib_main_t
 140  *   @return frame->n_vectors uword
 141 */
 142 static uword
 143 sr_replicate_node_fn (vlib_main_t * vm,
 144                       vlib_node_runtime_t * node, vlib_frame_t * frame)
 145 {
 146   dpdk_main_t *dm = &dpdk_main;
 147   u32 n_left_from, *from, *to_next;
 148   sr_replicate_next_t next_index;
 149   int pkts_replicated = 0;
 150   ip6_sr_main_t *sm = &sr_main;
 151   int no_buffer_drops = 0;
 152   vlib_buffer_free_list_t *fl;
 153   unsigned socket_id = rte_socket_id ();
 154
 155   from = vlib_frame_vector_args (frame);
 156   n_left_from = frame->n_vectors;
 157   next_index = node->cached_next_index;
 158
 159   fl = vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
 160
 161   while (n_left_from > 0)
 162     {
 163       u32 n_left_to_next;
 164
 165       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 166
 167       while (n_left_from > 0 && n_left_to_next > 0)
 168         {
 169           u32 bi0, hdr_bi0;
 170           vlib_buffer_t *b0, *orig_b0;
 171           struct rte_mbuf *orig_mb0 = 0, *hdr_mb0 = 0, *clone0 = 0;
 172           struct rte_mbuf **hdr_vec = 0, **rte_mbuf_vec = 0;
 173           ip6_sr_policy_t *pol0 = 0;
 174           ip6_sr_tunnel_t *t0 = 0;
 175           ip6_sr_header_t *hdr_sr0 = 0;
 176           ip6_header_t *ip0 = 0, *hdr_ip0 = 0;
 177           int num_replicas = 0;
 178           int i;
 179           u32 len_bytes = sizeof (ip6_header_t);
 180           u8 next_hdr, ip_next_hdr = IPPROTO_IPV6_ROUTE;
 181
 182           bi0 = from[0];
 183
 184           b0 = vlib_get_buffer (vm, bi0);
 185           orig_b0 = b0;
 186
 187           pol0 = pool_elt_at_index (sm->policies,
 188                                     vnet_buffer (b0)->ip.save_protocol);
 189
 190           ip0 = vlib_buffer_get_current (b0);
 191           /* Skip forward to the punch-in point */
 192           vlib_buffer_advance (b0, sizeof (*ip0));
 193           next_hdr = ip0->protocol;
 194
 195           /* HBH must immediately follow ipv6 header */
 196           if (PREDICT_FALSE
 197               (ip0->protocol == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS))
 198             {
 199               ip6_hop_by_hop_ext_t *ext_hdr =
 200                 (ip6_hop_by_hop_ext_t *) ip6_next_header (ip0);
 201               u32 ext_hdr_len = 0;
 202               ext_hdr_len = ip6_ext_header_len ((ip6_ext_header_t *) ext_hdr);
 203               len_bytes += ext_hdr_len;
 204               next_hdr = ext_hdr->next_hdr;
 205               ext_hdr->next_hdr = IPPROTO_IPV6_ROUTE;
 206               ip_next_hdr = IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS;
 207               /* Skip forward to the punch-in point */
 208               vlib_buffer_advance (b0, ext_hdr_len);
 209
 210             }
 211
 212           orig_mb0 = rte_mbuf_from_vlib_buffer (b0);
 213
 214           i16 delta0 = vlib_buffer_length_in_chain (vm, orig_b0)
 215             - (i16) orig_mb0->pkt_len;
 216
 217           u16 new_data_len0 = (u16) ((i16) orig_mb0->data_len + delta0);
 218           u16 new_pkt_len0 = (u16) ((i16) orig_mb0->pkt_len + delta0);
 219
 220           orig_mb0->data_len = new_data_len0;
 221           orig_mb0->pkt_len = new_pkt_len0;
 222           orig_mb0->data_off += (u16) (b0->current_data);
 223
 224           /*
 225              Before entering loop determine if we can allocate:
 226              - all the new HEADER RTE_MBUFs and assign them to a vector
 227              - all the clones
 228
 229              if successful, then iterate over vectors of resources
 230
 231            */
 232           num_replicas = vec_len (pol0->tunnel_indices);
 233
 234           if (PREDICT_FALSE (num_replicas == 0))
 235             {
 236               b0->error = node->errors[SR_REPLICATE_ERROR_NO_REPLICAS];
 237               goto do_trace0;
 238             }
 239
 240           vec_reset_length (hdr_vec);
 241           vec_reset_length (rte_mbuf_vec);
 242
 243           for (i = 0; i < num_replicas; i++)
 244             {
 245               uint8_t nb_seg;
 246               struct rte_mbuf *clone0i;
 247               vlib_buffer_t *clone0_c, *clone_b0;
 248
 249               t0 = vec_elt_at_index (sm->tunnels, pol0->tunnel_indices[i]);
 250               hdr_mb0 = rte_pktmbuf_alloc (dm->pktmbuf_pools[socket_id]);
 251
 252               if (i < (num_replicas - 1))
 253                 {
 254                   /* Not the last tunnel to process */
 255                   clone0 = rte_pktmbuf_clone
 256                     (orig_mb0, dm->pktmbuf_pools[socket_id]);
 257                   if (clone0 == 0)
 258                     goto clone_fail;
 259                   nb_seg = 0;
 260                   clone0i = clone0;
 261                   clone0_c = NULL;
 262                   while ((clone0->nb_segs >= 1) && (nb_seg < clone0->nb_segs))
 263                     {
 264
 265                       clone_b0 = vlib_buffer_from_rte_mbuf (clone0i);
 266                       vlib_buffer_init_for_free_list (clone_b0, fl);
 267
 268                       ASSERT ((clone_b0->flags & VLIB_BUFFER_NEXT_PRESENT) ==
 269                               0);
 270                       ASSERT (clone_b0->current_data == 0);
 271
 272                       clone_b0->current_data =
 273                         (clone0i->buf_addr + clone0i->data_off) -
 274                         (void *) clone_b0->data;
 275
 276                       clone_b0->current_length = clone0i->data_len;
 277                       if (PREDICT_FALSE (clone0_c != NULL))
 278                         {
 279                           clone0_c->flags |= VLIB_BUFFER_NEXT_PRESENT;
 280                           clone0_c->next_buffer =
 281                             vlib_get_buffer_index (vm, clone_b0);
 282                         }
 283                       clone0_c = clone_b0;
 284                       clone0i = clone0i->next;
 285                       nb_seg++;
 286                     }
 287                 }
 288               else
 289                 /* First tunnel to process, use original MB */
 290                 clone0 = orig_mb0;
 291
 292
 293               if (PREDICT_FALSE (!clone0 || !hdr_mb0))
 294                 {
 295                 clone_fail:
 296                   b0->error = node->errors[SR_REPLICATE_ERROR_NO_BUFFERS];
 297
 298                   vec_foreach_index (i, rte_mbuf_vec)
 299                   {
 300                     rte_pktmbuf_free (rte_mbuf_vec[i]);
 301                   }
 302                   vec_free (rte_mbuf_vec);
 303
 304                   vec_foreach_index (i, hdr_vec)
 305                   {
 306                     rte_pktmbuf_free (hdr_vec[i]);
 307                   }
 308                   vec_free (hdr_vec);
 309
 310                   goto do_trace0;
 311                 }
 312
 313               vec_add1 (hdr_vec, hdr_mb0);
 314               vec_add1 (rte_mbuf_vec, clone0);
 315
 316             }
 317
 318           for (i = 0; i < num_replicas; i++)
 319             {
 320               vlib_buffer_t *hdr_b0;
 321               u16 new_l0 = 0;
 322
 323               t0 = vec_elt_at_index (sm->tunnels, pol0->tunnel_indices[i]);
 324               /* Our replicas */
 325               hdr_mb0 = hdr_vec[i];
 326               clone0 = rte_mbuf_vec[i];
 327
 328               hdr_mb0->data_len = len_bytes + vec_len (t0->rewrite);
 329               hdr_mb0->pkt_len = hdr_mb0->data_len +
 330                 vlib_buffer_length_in_chain (vm, orig_b0);
 331
 332               hdr_b0 = vlib_buffer_from_rte_mbuf (hdr_mb0);
 333
 334               vlib_buffer_init_for_free_list (hdr_b0, fl);
 335
 336               memcpy (hdr_b0->data, ip0, len_bytes);
 337               memcpy (hdr_b0->data + len_bytes, t0->rewrite,
 338                       vec_len (t0->rewrite));
 339
 340               hdr_b0->current_data = 0;
 341               hdr_b0->current_length = len_bytes + vec_len (t0->rewrite);
 342               hdr_b0->flags = orig_b0->flags | VLIB_BUFFER_NEXT_PRESENT;
 343               hdr_b0->trace_index = orig_b0->trace_index;
 344               vnet_buffer (hdr_b0)->l2_classify.opaque_index = 0;
 345
 346               hdr_b0->total_length_not_including_first_buffer =
 347                 hdr_mb0->pkt_len - hdr_b0->current_length;
 348               vnet_buffer (hdr_b0)->sw_if_index[VLIB_TX] = t0->tx_fib_index;
 349
 350               hdr_ip0 = (ip6_header_t *) hdr_b0->data;
 351               new_l0 = clib_net_to_host_u16 (ip0->payload_length) +
 352                 vec_len (t0->rewrite);
 353               hdr_ip0->payload_length = clib_host_to_net_u16 (new_l0);
 354               hdr_sr0 = (ip6_sr_header_t *) ((u8 *) hdr_ip0 + len_bytes);
 355               /* $$$ tune */
 356               clib_memcpy (hdr_sr0, t0->rewrite, vec_len (t0->rewrite));
 357               hdr_sr0->protocol = next_hdr;
 358               hdr_ip0->protocol = ip_next_hdr;
 359
 360               /* Copy dst address into the DA slot in the segment list */
 361               clib_memcpy (hdr_sr0->segments, ip0->dst_address.as_u64,
 362                            sizeof (ip6_address_t));
 363
 364               /* Rewrite the ip6 dst address */
 365               hdr_ip0->dst_address.as_u64[0] = t0->first_hop.as_u64[0];
 366               hdr_ip0->dst_address.as_u64[1] = t0->first_hop.as_u64[1];
 367
 368               sr_fix_hmac (sm, hdr_ip0, hdr_sr0);
 369
 370               /* prepend new header to invariant piece */
 371               hdr_mb0->next = clone0;
 372               hdr_b0->next_buffer =
 373                 vlib_get_buffer_index (vm,
 374                                        vlib_buffer_from_rte_mbuf (clone0));
 375
 376               /* update header's fields */
 377               hdr_mb0->pkt_len =
 378                 (uint16_t) (hdr_mb0->data_len + clone0->pkt_len);
 379               hdr_mb0->nb_segs = (uint8_t) (clone0->nb_segs + 1);
 380
 381               /* copy metadata from source packet */
 382               hdr_mb0->port = clone0->port;
 383               hdr_mb0->vlan_tci = clone0->vlan_tci;
 384               hdr_mb0->vlan_tci_outer = clone0->vlan_tci_outer;
 385               hdr_mb0->tx_offload = clone0->tx_offload;
 386               hdr_mb0->hash = clone0->hash;
 387
 388               hdr_mb0->ol_flags = clone0->ol_flags & ~(IND_ATTACHED_MBUF);
 389
 390               __rte_mbuf_sanity_check (hdr_mb0, 1);
 391
 392               hdr_bi0 = vlib_get_buffer_index (vm, hdr_b0);
 393
 394               to_next[0] = hdr_bi0;
 395               to_next += 1;
 396               n_left_to_next -= 1;
 397
 398               if (n_left_to_next == 0)
 399                 {
 400                   vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 401                   vlib_get_next_frame (vm, node, next_index,
 402                                        to_next, n_left_to_next);
 403
 404                 }
 405               pkts_replicated++;
 406             }
 407
 408           from += 1;
 409           n_left_from -= 1;
 410
 411         do_trace0:
 412           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 413             {
 414               sr_replicate_trace_t *tr = vlib_add_trace (vm, node,
 415                                                          b0, sizeof (*tr));
 416               tr->tunnel_index = t0 - sm->tunnels;
 417               tr->length = 0;
 418               if (hdr_ip0)
 419                 {
 420                   memcpy (tr->src.as_u8, hdr_ip0->src_address.as_u8,
 421                           sizeof (tr->src.as_u8));
 422                   memcpy (tr->dst.as_u8, hdr_ip0->dst_address.as_u8,
 423                           sizeof (tr->dst.as_u8));
 424                   if (hdr_ip0->payload_length)
 425                     tr->length = clib_net_to_host_u16
 426                       (hdr_ip0->payload_length);
 427                 }
 428               tr->next_index = next_index;
 429               if (hdr_sr0)
 430                 memcpy (tr->sr, hdr_sr0, sizeof (tr->sr));
 431             }
 432
 433         }
 434
 435       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 436     }
 437
 438   vlib_node_increment_counter (vm, sr_replicate_node.index,
 439                                SR_REPLICATE_ERROR_REPLICATED,
 440                                pkts_replicated);
 441
 442   vlib_node_increment_counter (vm, sr_replicate_node.index,
 443                                SR_REPLICATE_ERROR_NO_BUFFER_DROPS,
 444                                no_buffer_drops);
 445
 446   return frame->n_vectors;
 447 }
 448
 449 /* *INDENT-OFF* */
 450 VLIB_REGISTER_NODE (sr_replicate_node) = {
 451   .function = sr_replicate_node_fn,
 452   .name = "sr-replicate",
 453   .vector_size = sizeof (u32),
 454   .format_trace = format_sr_replicate_trace,
 455   .type = VLIB_NODE_TYPE_INTERNAL,
 456
 457   .n_errors = ARRAY_LEN(sr_replicate_error_strings),
 458   .error_strings = sr_replicate_error_strings,
 459
 460   .n_next_nodes = SR_REPLICATE_N_NEXT,
 461
 462   .next_nodes = {
 463         [SR_REPLICATE_NEXT_IP6_LOOKUP] = "ip6-lookup",
 464   },
 465 };
 466
 467 VLIB_NODE_FUNCTION_MULTIARCH (sr_replicate_node, sr_replicate_node_fn)
 468 /* *INDENT-ON* */
 469
 470 clib_error_t *
 471 sr_replicate_init (vlib_main_t * vm)
 472 {
 473   sr_replicate_main_t *msm = &sr_replicate_main;
 474
 475   msm->vlib_main = vm;
 476   msm->vnet_main = vnet_get_main ();
 477
 478   return 0;
 479 }
 480
 481 VLIB_INIT_FUNCTION (sr_replicate_init);
 482
 483 #endif /* DPDK */
 484
 485 /*
 486  * fd.io coding-style-patch-verification: ON
 487  *
 488  * Local Variables:
 489  * eval: (c-set-style "gnu")
 490  * End:
 491  */