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   return 0;
 216 }
 217
 218 static int
 219 srv6_as_localsid_removal_fn (ip6_sr_localsid_t * localsid)
 220 {
 221   srv6_as_main_t *sm = &srv6_as_main;
 222   srv6_as_localsid_t *ls_mem = localsid->plugin_mem;
 223
 224   if (ls_mem->ip_version == DA_IP4)
 225     {
 226       /* Disable End.AS4 rewrite node for this interface */
 227       int ret;
 228       ret = vnet_feature_enable_disable ("ip4-unicast", "srv6-as4-rewrite",
 229                                          ls_mem->sw_if_index_in, 0, 0, 0);
 230       if (ret != 0)
 231         return -1;
 232
 233       /* Remove local SID index from interface table */
 234       sm->sw_iface_localsid4[ls_mem->sw_if_index_in] = ~(u32) 0;
 235     }
 236   else if (ls_mem->ip_version == DA_IP6)
 237     {
 238       /* Disable End.AS6 rewrite node for this interface */
 239       int ret;
 240       ret = vnet_feature_enable_disable ("ip6-unicast", "srv6-as6-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_localsid6[ls_mem->sw_if_index_in] = ~(u32) 0;
 247     }
 248
 249
 250   /* Unlock (OIF, NHOP) adjacency (from sr_localsid.c:103) */
 251   adj_unlock (ls_mem->nh_adj);
 252
 253   /* Clean up local SID memory */
 254   free_ls_mem (ls_mem);
 255
 256   return 0;
 257 }
 258
 259 /**********************************/
 260 /* SRv6 LocalSID format functions */
 261 /*
 262  * Prints nicely the parameters of a localsid
 263  * Example: print "Table 5"
 264  */
 265 u8 *
 266 format_srv6_as_localsid (u8 * s, va_list * args)
 267 {
 268   srv6_as_localsid_t *ls_mem = va_arg (*args, void *);
 269
 270   vnet_main_t *vnm = vnet_get_main ();
 271
 272   if (ls_mem->ip_version == DA_IP4)
 273     {
 274       s =
 275         format (s, "Next-hop:\t%U\n", format_ip4_address,
 276                 &ls_mem->nh_addr.ip4);
 277     }
 278   else
 279     {
 280       s =
 281         format (s, "Next-hop:\t%U\n", format_ip6_address,
 282                 &ls_mem->nh_addr.ip6);
 283     }
 284
 285   s = format (s, "\tOutgoing iface:\t%U\n", format_vnet_sw_if_index_name, vnm,
 286               ls_mem->sw_if_index_out);
 287   s = format (s, "\tIncoming iface:\t%U\n", format_vnet_sw_if_index_name, vnm,
 288               ls_mem->sw_if_index_in);
 289   s = format (s, "\tSource address:\t%U\n", format_ip6_address,
 290               &ls_mem->src_addr);
 291
 292   s = format (s, "\tSegment list:\t< ");
 293   ip6_address_t *addr;
 294   vec_foreach (addr, ls_mem->sid_list)
 295   {
 296     s = format (s, "%U, ", format_ip6_address, addr);
 297   }
 298   s = format (s, "\b\b > ");
 299
 300   return s;
 301 }
 302
 303 /*
 304  * Process the parameters of a localsid
 305  * Example: process from:
 306  * sr localsid address cafe::1 behavior new_srv6_localsid 5
 307  * everything from behavior on... so in this case 'new_srv6_localsid 5'
 308  * Notice that it MUST match the keyword_str and params_str defined above.
 309  */
 310 uword
 311 unformat_srv6_as_localsid (unformat_input_t * input, va_list * args)
 312 {
 313   void **plugin_mem_p = va_arg (*args, void **);
 314   srv6_as_localsid_t *ls_mem;
 315
 316   vnet_main_t *vnm = vnet_get_main ();
 317
 318   u8 ip_version = 0;
 319   ip46_address_t nh_addr;
 320   u32 sw_if_index_out;
 321   u32 sw_if_index_in;
 322   ip6_address_t src_addr;
 323   ip6_address_t next_sid;
 324   ip6_address_t *sid_list = NULL;
 325
 326   u8 params = 0;
 327 #define PARAM_AS_NH   (1 << 0)
 328 #define PARAM_AS_OIF  (1 << 1)
 329 #define PARAM_AS_IIF  (1 << 2)
 330 #define PARAM_AS_SRC  (1 << 3)
 331
 332   if (!unformat (input, "end.as"))
 333     return 0;
 334
 335   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 336     {
 337       if (!(params & PARAM_AS_NH) && unformat (input, "nh %U",
 338                                                unformat_ip4_address,
 339                                                &nh_addr.ip4))
 340         {
 341           ip_version = DA_IP4;
 342           params |= PARAM_AS_NH;
 343         }
 344       if (!(params & PARAM_AS_NH) && unformat (input, "nh %U",
 345                                                unformat_ip6_address,
 346                                                &nh_addr.ip6))
 347         {
 348           ip_version = DA_IP6;
 349           params |= PARAM_AS_NH;
 350         }
 351       else if (!(params & PARAM_AS_OIF) && unformat (input, "oif %U",
 352                                                      unformat_vnet_sw_interface,
 353                                                      vnm, &sw_if_index_out))
 354         {
 355           params |= PARAM_AS_OIF;
 356         }
 357       else if (!(params & PARAM_AS_IIF) && unformat (input, "iif %U",
 358                                                      unformat_vnet_sw_interface,
 359                                                      vnm, &sw_if_index_in))
 360         {
 361           params |= PARAM_AS_IIF;
 362         }
 363       else if (!(params & PARAM_AS_SRC) && unformat (input, "src %U",
 364                                                      unformat_ip6_address,
 365                                                      &src_addr))
 366         {
 367           params |= PARAM_AS_SRC;
 368         }
 369       else if (unformat (input, "next %U", unformat_ip6_address, &next_sid))
 370         {
 371           vec_add1 (sid_list, next_sid);
 372         }
 373       else
 374         {
 375           break;
 376         }
 377     }
 378
 379   /* Make sure that all parameters are supplied */
 380   u8 params_chk = (PARAM_AS_NH | PARAM_AS_OIF | PARAM_AS_IIF | PARAM_AS_SRC);
 381   if ((params & params_chk) != params_chk || sid_list == NULL)
 382     {
 383       vec_free (sid_list);
 384       return 0;
 385     }
 386
 387   /* Allocate and initialize memory block for local SID parameters */
 388   ls_mem = clib_mem_alloc_aligned_at_offset (sizeof *ls_mem, 0, 0, 1);
 389   memset (ls_mem, 0, sizeof *ls_mem);
 390   *plugin_mem_p = ls_mem;
 391
 392   /* Set local SID parameters */
 393   ls_mem->ip_version = ip_version;
 394   if (ip_version == DA_IP4)
 395     ls_mem->nh_addr.ip4 = nh_addr.ip4;
 396   else
 397     ls_mem->nh_addr.ip6 = nh_addr.ip6;
 398   ls_mem->sw_if_index_out = sw_if_index_out;
 399   ls_mem->sw_if_index_in = sw_if_index_in;
 400   ls_mem->src_addr = src_addr;
 401   ls_mem->sid_list = sid_list;
 402
 403   return 1;
 404 }
 405
 406 /*************************/
 407 /* SRv6 LocalSID FIB DPO */
 408 static u8 *
 409 format_srv6_as_dpo (u8 * s, va_list * args)
 410 {
 411   index_t index = va_arg (*args, index_t);
 412   CLIB_UNUSED (u32 indent) = va_arg (*args, u32);
 413
 414   return (format (s, "SR: static_proxy_index:[%u]", index));
 415 }
 416
 417 void
 418 srv6_as_dpo_lock (dpo_id_t * dpo)
 419 {
 420 }
 421
 422 void
 423 srv6_as_dpo_unlock (dpo_id_t * dpo)
 424 {
 425 }
 426
 427 const static dpo_vft_t srv6_as_vft = {
 428   .dv_lock = srv6_as_dpo_lock,
 429   .dv_unlock = srv6_as_dpo_unlock,
 430   .dv_format = format_srv6_as_dpo,
 431 };
 432
 433 const static char *const srv6_as_ip6_nodes[] = {
 434   "srv6-as-localsid",
 435   NULL,
 436 };
 437
 438 const static char *const *const srv6_as_nodes[DPO_PROTO_NUM] = {
 439   [DPO_PROTO_IP6] = srv6_as_ip6_nodes,
 440 };
 441
 442 /**********************/
 443 static clib_error_t *
 444 srv6_as_init (vlib_main_t * vm)
 445 {
 446   srv6_as_main_t *sm = &srv6_as_main;
 447   int rv = 0;
 448
 449   sm->vlib_main = vm;
 450   sm->vnet_main = vnet_get_main ();
 451
 452   /* Create DPO */
 453   sm->srv6_as_dpo_type = dpo_register_new_type (&srv6_as_vft, srv6_as_nodes);
 454
 455   /* Register SRv6 LocalSID */
 456   rv = sr_localsid_register_function (vm,
 457                                       function_name,
 458                                       keyword_str,
 459                                       def_str,
 460                                       params_str,
 461                                       &sm->srv6_as_dpo_type,
 462                                       format_srv6_as_localsid,
 463                                       unformat_srv6_as_localsid,
 464                                       srv6_as_localsid_creation_fn,
 465                                       srv6_as_localsid_removal_fn);
 466   if (rv < 0)
 467     clib_error_return (0, "SRv6 LocalSID function could not be registered.");
 468   else
 469     sm->srv6_localsid_behavior_id = rv;
 470
 471   return 0;
 472 }
 473
 474 /* *INDENT-OFF* */
 475 VNET_FEATURE_INIT (srv6_as4_rewrite, static) =
 476 {
 477   .arc_name = "ip4-unicast",
 478   .node_name = "srv6-as4-rewrite",
 479   .runs_before = 0,
 480 };
 481
 482 VNET_FEATURE_INIT (srv6_as6_rewrite, static) =
 483 {
 484   .arc_name = "ip6-unicast",
 485   .node_name = "srv6-as6-rewrite",
 486   .runs_before = 0,
 487 };
 488
 489 VLIB_INIT_FUNCTION (srv6_as_init);
 490
 491 VLIB_PLUGIN_REGISTER () = {
 492   .version = VPP_BUILD_VER,
 493   .description = "Static SRv6 proxy",
 494 };
 495 /* *INDENT-ON* */
 496
 497 /*
 498 * fd.io coding-style-patch-verification: ON
 499 *
 500 * Local Variables:
 501 * eval: (c-set-style "gnu")
 502 * End:
 503 */