src/plugins/srv6-as/as.c

   1 /*
   2  * Copyright (c) 2015 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  * as.c - SRv6 Static Proxy (AS) function
  18  *------------------------------------------------------------------
  19  */
  20
  21 #include <vnet/vnet.h>
  22 #include <vnet/adj/adj.h>
  23 #include <vnet/plugin/plugin.h>
  24 #include <vpp/app/version.h>
  25 #include <srv6-as/as.h>
  26
  27 #define SID_CREATE_IFACE_FEATURE_ERROR  -1
  28 #define SID_CREATE_INVALID_IFACE_TYPE   -3
  29 #define SID_CREATE_INVALID_IFACE_INDEX  -4
  30 #define SID_CREATE_INVALID_ADJ_INDEX    -5
  31
  32 unsigned char function_name[] = "SRv6-AS-plugin";
  33 unsigned char keyword_str[] = "End.AS";
  34 unsigned char def_str[] =
  35   "Endpoint with static proxy to SR-unaware appliance";
  36 unsigned char params_str[] =
  37   "nh <next-hop> oif <iface-out> iif <iface-in> src <src-addr> next <sid> [next <sid> ...]";
  38
  39
  40 static inline u8 *
  41 prepare_rewrite (ip6_address_t src_addr, ip6_address_t * sid_list,
  42                  u8 protocol)
  43 {
  44   u8 *rewrite_str = NULL;
  45   u32 rewrite_len = IPv6_DEFAULT_HEADER_LENGTH;
  46
  47   u8 num_sids = vec_len (sid_list);
  48   u32 sr_hdr_len = 0;
  49
  50   if (num_sids > 1)
  51     {
  52       sr_hdr_len =
  53         sizeof (ip6_sr_header_t) + num_sids * sizeof (ip6_address_t);
  54       rewrite_len += sr_hdr_len;
  55     }
  56
  57   vec_validate (rewrite_str, rewrite_len - 1);
  58
  59   /* Fill IP header */
  60   ip6_header_t *iph = (ip6_header_t *) rewrite_str;
  61   iph->ip_version_traffic_class_and_flow_label =
  62     clib_host_to_net_u32 (0 | ((6 & 0xF) << 28));
  63   iph->src_address = src_addr;
  64   iph->dst_address = sid_list[0];
  65   iph->payload_length = sr_hdr_len;
  66   iph->hop_limit = IPv6_DEFAULT_HOP_LIMIT;
  67
  68   if (num_sids > 1)
  69     {
  70       /* Set Next Header value to Routing Extension */
  71       iph->protocol = IP_PROTOCOL_IPV6_ROUTE;
  72
  73       /* Fill SR header */
  74       ip6_sr_header_t *srh = (ip6_sr_header_t *) (iph + 1);
  75       srh->protocol = protocol;
  76       srh->length = sr_hdr_len / 8 - 1;
  77       srh->type = ROUTING_HEADER_TYPE_SR;
  78       srh->segments_left = num_sids - 1;
  79       srh->first_segment = num_sids - 1;
  80       srh->flags = 0x00;
  81       srh->reserved = 0x00;
  82
  83       /* Fill segment list */
  84       ip6_address_t *this_address;
  85       ip6_address_t *addrp = srh->segments + srh->first_segment;
  86       vec_foreach (this_address, sid_list)
  87       {
  88         *addrp = *this_address;
  89         addrp--;
  90       }
  91     }
  92   else
  93     {
  94       /* Set Next Header value to inner protocol */
  95       iph->protocol = protocol;
  96     }
  97
  98   return rewrite_str;
  99 }
 100
 101 static inline void
 102 free_ls_mem (srv6_as_localsid_t * ls_mem)
 103 {
 104   vec_free (ls_mem->rewrite);
 105   vec_free (ls_mem->sid_list);
 106   clib_mem_free (ls_mem);
 107 }
 108
 109
 110 /*****************************************/
 111 /* SRv6 LocalSID instantiation and removal functions */
 112 static int
 113 srv6_as_localsid_creation_fn (ip6_sr_localsid_t * localsid)
 114 {
 115   ip6_sr_main_t *srm = &sr_main;
 116   srv6_as_main_t *sm = &srv6_as_main;
 117   srv6_as_localsid_t *ls_mem = localsid->plugin_mem;
 118   u32 localsid_index = localsid - srm->localsids;
 119
 120   /* Step 1: Prepare xconnect adjacency for sending packets to the VNF */
 121
 122   /* Retrieve the adjacency corresponding to the (OIF, next_hop) */
 123   adj_index_t nh_adj_index = ADJ_INDEX_INVALID;
 124   if (ls_mem->ip_version == DA_IP4)
 125     nh_adj_index = adj_nbr_add_or_lock (FIB_PROTOCOL_IP4,
 126                                         VNET_LINK_IP4, &ls_mem->nh_addr,
 127                                         ls_mem->sw_if_index_out);
 128   else if (ls_mem->ip_version == DA_IP6)
 129     nh_adj_index = adj_nbr_add_or_lock (FIB_PROTOCOL_IP6,
 130                                         VNET_LINK_IP6, &ls_mem->nh_addr,
 131                                         ls_mem->sw_if_index_out);
 132   if (nh_adj_index == ADJ_INDEX_INVALID)
 133     {
 134       free_ls_mem (ls_mem);
 135       return SID_CREATE_INVALID_ADJ_INDEX;
 136     }
 137
 138   ls_mem->nh_adj = nh_adj_index;
 139
 140
 141   /* Step 2: Prepare inbound policy for packets returning from the VNF */
 142
 143   /* Make sure the provided incoming interface index is valid */
 144   if (pool_is_free_index (sm->vnet_main->interface_main.sw_interfaces,
 145                           ls_mem->sw_if_index_in))
 146     {
 147       adj_unlock (ls_mem->nh_adj);
 148       free_ls_mem (ls_mem);
 149       return SID_CREATE_INVALID_IFACE_INDEX;
 150     }
 151
 152   /* Retrieve associated interface structure */
 153   vnet_sw_interface_t *sw = vnet_get_sw_interface (sm->vnet_main,
 154                                                    ls_mem->sw_if_index_in);
 155   if (sw->type != VNET_SW_INTERFACE_TYPE_HARDWARE)
 156     {
 157       adj_unlock (ls_mem->nh_adj);
 158       free_ls_mem (ls_mem);
 159       return SID_CREATE_INVALID_IFACE_TYPE;
 160     }
 161
 162   if (ls_mem->ip_version == DA_IP4)
 163     {
 164       /* Enable End.AS4 rewrite node for this interface */
 165       int ret =
 166         vnet_feature_enable_disable ("ip4-unicast", "srv6-as4-rewrite",
 167                                      ls_mem->sw_if_index_in, 1, 0, 0);
 168       if (ret != 0)
 169         {
 170           adj_unlock (ls_mem->nh_adj);
 171           free_ls_mem (ls_mem);
 172           return SID_CREATE_IFACE_FEATURE_ERROR;
 173         }
 174
 175       /* Prepare rewrite string */
 176       ls_mem->rewrite = prepare_rewrite (ls_mem->src_addr, ls_mem->sid_list,
 177                                          IP_PROTOCOL_IP_IN_IP);
 178
 179       /* Associate local SID index to this interface (resize vector if needed) */
 180       if (ls_mem->sw_if_index_in >= vec_len (sm->sw_iface_localsid4))
 181         {
 182           vec_resize (sm->sw_iface_localsid4,
 183                       (pool_len (sm->vnet_main->interface_main.sw_interfaces)
 184                        - vec_len (sm->sw_iface_localsid4)));
 185         }
 186       sm->sw_iface_localsid4[ls_mem->sw_if_index_in] = localsid_index;
 187     }
 188   else if (ls_mem->ip_version == DA_IP6)
 189     {
 190       /* Enable End.AS6 rewrite node for this interface */
 191       int ret =
 192         vnet_feature_enable_disable ("ip6-unicast", "srv6-as6-rewrite",
 193                                      ls_mem->sw_if_index_in, 1, 0, 0);
 194       if (ret != 0)
 195         {
 196           adj_unlock (ls_mem->nh_adj);
 197           free_ls_mem (ls_mem);
 198           return SID_CREATE_IFACE_FEATURE_ERROR;
 199         }
 200
 201       /* Prepare rewrite string */
 202       ls_mem->rewrite = prepare_rewrite (ls_mem->src_addr, ls_mem->sid_list,
 203                                          IP_PROTOCOL_IPV6);
 204
 205       /* Associate local SID index to this interface (resize vector if needed) */
 206       if (ls_mem->sw_if_index_in >= vec_len (sm->sw_iface_localsid6))
 207         {
 208           vec_resize (sm->sw_iface_localsid6,
 209                       (pool_len (sm->vnet_main->interface_main.sw_interfaces)
 210                        - vec_len (sm->sw_iface_localsid6)));
 211         }
 212       sm->sw_iface_localsid6[ls_mem->sw_if_index_in] = localsid_index;
 213     }
 214
 215   /* Step 3: Initialize rewrite counters */
 216   srv6_as_localsid_t **ls_p;
 217   pool_get (sm->sids, ls_p);
 218   *ls_p = ls_mem;
 219   ls_mem->index = ls_p - sm->sids;
 220
 221   vlib_validate_combined_counter (&(sm->valid_counters), ls_mem->index);
 222   vlib_validate_combined_counter (&(sm->invalid_counters), ls_mem->index);
 223
 224   vlib_zero_combined_counter (&(sm->valid_counters), ls_mem->index);
 225   vlib_zero_combined_counter (&(sm->invalid_counters), ls_mem->index);
 226
 227   return 0;
 228 }
 229
 230 static int
 231 srv6_as_localsid_removal_fn (ip6_sr_localsid_t * localsid)
 232 {
 233   srv6_as_main_t *sm = &srv6_as_main;
 234   srv6_as_localsid_t *ls_mem = localsid->plugin_mem;
 235
 236   if (ls_mem->ip_version == DA_IP4)
 237     {
 238       /* Disable End.AS4 rewrite node for this interface */
 239       int ret;
 240       ret = vnet_feature_enable_disable ("ip4-unicast", "srv6-as4-rewrite",
 241                                          ls_mem->sw_if_index_in, 0, 0, 0);
 242       if (ret != 0)
 243         return -1;
 244
 245       /* Remove local SID index from interface table */
 246       sm->sw_iface_localsid4[ls_mem->sw_if_index_in] = ~(u32) 0;
 247     }
 248   else if (ls_mem->ip_version == DA_IP6)
 249     {
 250       /* Disable End.AS6 rewrite node for this interface */
 251       int ret;
 252       ret = vnet_feature_enable_disable ("ip6-unicast", "srv6-as6-rewrite",
 253                                          ls_mem->sw_if_index_in, 0, 0, 0);
 254       if (ret != 0)
 255         return -1;
 256
 257       /* Remove local SID index from interface table */
 258       sm->sw_iface_localsid6[ls_mem->sw_if_index_in] = ~(u32) 0;
 259     }
 260
 261
 262   /* Unlock (OIF, NHOP) adjacency (from sr_localsid.c:103) */
 263   adj_unlock (ls_mem->nh_adj);
 264
 265   /* Delete SID entry */
 266   pool_put (sm->sids, pool_elt_at_index (sm->sids, ls_mem->index));
 267
 268   /* Clean up local SID memory */
 269   free_ls_mem (ls_mem);
 270
 271   return 0;
 272 }
 273
 274 /**********************************/
 275 /* SRv6 LocalSID format functions */
 276 /*
 277  * Prints nicely the parameters of a localsid
 278  * Example: print "Table 5"
 279  */
 280 u8 *
 281 format_srv6_as_localsid (u8 * s, va_list * args)
 282 {
 283   srv6_as_localsid_t *ls_mem = va_arg (*args, void *);
 284
 285   vnet_main_t *vnm = vnet_get_main ();
 286   srv6_as_main_t *sm = &srv6_as_main;
 287
 288   if (ls_mem->ip_version == DA_IP4)
 289     {
 290       s =
 291         format (s, "Next-hop:\t%U\n", format_ip4_address,
 292                 &ls_mem->nh_addr.ip4);
 293     }
 294   else
 295     {
 296       s =
 297         format (s, "Next-hop:\t%U\n", format_ip6_address,
 298                 &ls_mem->nh_addr.ip6);
 299     }
 300
 301   s = format (s, "\tOutgoing iface:\t%U\n", format_vnet_sw_if_index_name, vnm,
 302               ls_mem->sw_if_index_out);
 303   s = format (s, "\tIncoming iface:\t%U\n", format_vnet_sw_if_index_name, vnm,
 304               ls_mem->sw_if_index_in);
 305   s = format (s, "\tSource address:\t%U\n", format_ip6_address,
 306               &ls_mem->src_addr);
 307
 308   s = format (s, "\tSegment list:\t< ");
 309   ip6_address_t *addr;
 310   vec_foreach (addr, ls_mem->sid_list)
 311   {
 312     s = format (s, "%U, ", format_ip6_address, addr);
 313   }
 314   s = format (s, "\b\b >\n");
 315
 316   vlib_counter_t valid, invalid;
 317   vlib_get_combined_counter (&(sm->valid_counters), ls_mem->index, &valid);
 318   vlib_get_combined_counter (&(sm->invalid_counters), ls_mem->index,
 319                              &invalid);
 320   s =
 321     format (s, "\tGood rewrite traffic: \t[%Ld packets : %Ld bytes]\n",
 322             valid.packets, valid.bytes);
 323   s =
 324     format (s, "\tBad rewrite traffic:  \t[%Ld packets : %Ld bytes]\n",
 325             invalid.packets, invalid.bytes);
 326
 327   return s;
 328 }
 329
 330 /*
 331  * Process the parameters of a localsid
 332  * Example: process from:
 333  * sr localsid address cafe::1 behavior new_srv6_localsid 5
 334  * everything from behavior on... so in this case 'new_srv6_localsid 5'
 335  * Notice that it MUST match the keyword_str and params_str defined above.
 336  */
 337 uword
 338 unformat_srv6_as_localsid (unformat_input_t * input, va_list * args)
 339 {
 340   void **plugin_mem_p = va_arg (*args, void **);
 341   srv6_as_localsid_t *ls_mem;
 342
 343   vnet_main_t *vnm = vnet_get_main ();
 344
 345   u8 ip_version = 0;
 346   ip46_address_t nh_addr;
 347   u32 sw_if_index_out;
 348   u32 sw_if_index_in;
 349   ip6_address_t src_addr;
 350   ip6_address_t next_sid;
 351   ip6_address_t *sid_list = NULL;
 352
 353   u8 params = 0;
 354 #define PARAM_AS_NH   (1 << 0)
 355 #define PARAM_AS_OIF  (1 << 1)
 356 #define PARAM_AS_IIF  (1 << 2)
 357 #define PARAM_AS_SRC  (1 << 3)
 358
 359   if (!unformat (input, "end.as"))
 360     return 0;
 361
 362   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 363     {
 364       if (!(params & PARAM_AS_NH) && unformat (input, "nh %U",
 365                                                unformat_ip4_address,
 366                                                &nh_addr.ip4))
 367         {
 368           ip_version = DA_IP4;
 369           params |= PARAM_AS_NH;
 370         }
 371       if (!(params & PARAM_AS_NH) && unformat (input, "nh %U",
 372                                                unformat_ip6_address,
 373                                                &nh_addr.ip6))
 374         {
 375           ip_version = DA_IP6;
 376           params |= PARAM_AS_NH;
 377         }
 378       else if (!(params & PARAM_AS_OIF) && unformat (input, "oif %U",
 379                                                      unformat_vnet_sw_interface,
 380                                                      vnm, &sw_if_index_out))
 381         {
 382           params |= PARAM_AS_OIF;
 383         }
 384       else if (!(params & PARAM_AS_IIF) && unformat (input, "iif %U",
 385                                                      unformat_vnet_sw_interface,
 386                                                      vnm, &sw_if_index_in))
 387         {
 388           params |= PARAM_AS_IIF;
 389         }
 390       else if (!(params & PARAM_AS_SRC) && unformat (input, "src %U",
 391                                                      unformat_ip6_address,
 392                                                      &src_addr))
 393         {
 394           params |= PARAM_AS_SRC;
 395         }
 396       else if (unformat (input, "next %U", unformat_ip6_address, &next_sid))
 397         {
 398           vec_add1 (sid_list, next_sid);
 399         }
 400       else
 401         {
 402           break;
 403         }
 404     }
 405
 406   /* Make sure that all parameters are supplied */
 407   u8 params_chk = (PARAM_AS_NH | PARAM_AS_OIF | PARAM_AS_IIF | PARAM_AS_SRC);
 408   if ((params & params_chk) != params_chk || sid_list == NULL)
 409     {
 410       vec_free (sid_list);
 411       return 0;
 412     }
 413
 414   /* Allocate and initialize memory block for local SID parameters */
 415   ls_mem = clib_mem_alloc_aligned_at_offset (sizeof *ls_mem, 0, 0, 1);
 416   memset (ls_mem, 0, sizeof *ls_mem);
 417   *plugin_mem_p = ls_mem;
 418
 419   /* Set local SID parameters */
 420   ls_mem->ip_version = ip_version;
 421   if (ip_version == DA_IP4)
 422     ls_mem->nh_addr.ip4 = nh_addr.ip4;
 423   else
 424     ls_mem->nh_addr.ip6 = nh_addr.ip6;
 425   ls_mem->sw_if_index_out = sw_if_index_out;
 426   ls_mem->sw_if_index_in = sw_if_index_in;
 427   ls_mem->src_addr = src_addr;
 428   ls_mem->sid_list = sid_list;
 429
 430   return 1;
 431 }
 432
 433 /*************************/
 434 /* SRv6 LocalSID FIB DPO */
 435 static u8 *
 436 format_srv6_as_dpo (u8 * s, va_list * args)
 437 {
 438   index_t index = va_arg (*args, index_t);
 439   CLIB_UNUSED (u32 indent) = va_arg (*args, u32);
 440
 441   return (format (s, "SR: static_proxy_index:[%u]", index));
 442 }
 443
 444 void
 445 srv6_as_dpo_lock (dpo_id_t * dpo)
 446 {
 447 }
 448
 449 void
 450 srv6_as_dpo_unlock (dpo_id_t * dpo)
 451 {
 452 }
 453
 454 const static dpo_vft_t srv6_as_vft = {
 455   .dv_lock = srv6_as_dpo_lock,
 456   .dv_unlock = srv6_as_dpo_unlock,
 457   .dv_format = format_srv6_as_dpo,
 458 };
 459
 460 const static char *const srv6_as_ip6_nodes[] = {
 461   "srv6-as-localsid",
 462   NULL,
 463 };
 464
 465 const static char *const *const srv6_as_nodes[DPO_PROTO_NUM] = {
 466   [DPO_PROTO_IP6] = srv6_as_ip6_nodes,
 467 };
 468
 469 /**********************/
 470 static clib_error_t *
 471 srv6_as_init (vlib_main_t * vm)
 472 {
 473   srv6_as_main_t *sm = &srv6_as_main;
 474   int rv = 0;
 475
 476   sm->vlib_main = vm;
 477   sm->vnet_main = vnet_get_main ();
 478
 479   /* Create DPO */
 480   sm->srv6_as_dpo_type = dpo_register_new_type (&srv6_as_vft, srv6_as_nodes);
 481
 482   /* Register SRv6 LocalSID */
 483   rv = sr_localsid_register_function (vm,
 484                                       function_name,
 485                                       keyword_str,
 486                                       def_str,
 487                                       params_str,
 488                                       &sm->srv6_as_dpo_type,
 489                                       format_srv6_as_localsid,
 490                                       unformat_srv6_as_localsid,
 491                                       srv6_as_localsid_creation_fn,
 492                                       srv6_as_localsid_removal_fn);
 493   if (rv < 0)
 494     clib_error_return (0, "SRv6 LocalSID function could not be registered.");
 495   else
 496     sm->srv6_localsid_behavior_id = rv;
 497
 498   return 0;
 499 }
 500
 501 /* *INDENT-OFF* */
 502 VNET_FEATURE_INIT (srv6_as4_rewrite, static) =
 503 {
 504   .arc_name = "ip4-unicast",
 505   .node_name = "srv6-as4-rewrite",
 506   .runs_before = 0,
 507 };
 508
 509 VNET_FEATURE_INIT (srv6_as6_rewrite, static) =
 510 {
 511   .arc_name = "ip6-unicast",
 512   .node_name = "srv6-as6-rewrite",
 513   .runs_before = 0,
 514 };
 515
 516 VLIB_INIT_FUNCTION (srv6_as_init);
 517
 518 VLIB_PLUGIN_REGISTER () = {
 519   .version = VPP_BUILD_VER,
 520   .description = "Static SRv6 proxy",
 521 };
 522 /* *INDENT-ON* */
 523
 524 /*
 525 * fd.io coding-style-patch-verification: ON
 526 *
 527 * Local Variables:
 528 * eval: (c-set-style "gnu")
 529 * End:
 530 */