src/vnet/ipsec/ipsec_itf.c

   1 /*
   2  * ipsec_itf.c: IPSec dedicated interface type
   3  *
   4  * Copyright (c) 2020 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 #include <vnet/ip/ip.h>
  19 #include <vnet/ipsec/ipsec_itf.h>
  20 #include <vnet/ipsec/ipsec_tun.h>
  21 #include <vnet/ipsec/ipsec.h>
  22 #include <vnet/adj/adj_midchain.h>
  23 #include <vnet/ethernet/mac_address.h>
  24 #include <vnet/mpls/mpls.h>
  25
  26 /* bitmap of Allocated IPSEC_ITF instances */
  27 static uword *ipsec_itf_instances;
  28
  29 /* pool of interfaces */
  30 static ipsec_itf_t *ipsec_itf_pool;
  31
  32 static u32 *ipsec_itf_index_by_sw_if_index;
  33
  34 ipsec_itf_t *
  35 ipsec_itf_get (index_t ii)
  36 {
  37   return (pool_elt_at_index (ipsec_itf_pool, ii));
  38 }
  39
  40 u32
  41 ipsec_itf_count (void)
  42 {
  43   return (pool_elts (ipsec_itf_pool));
  44 }
  45
  46 static ipsec_itf_t *
  47 ipsec_itf_find_by_sw_if_index (u32 sw_if_index)
  48 {
  49   if (vec_len (ipsec_itf_index_by_sw_if_index) <= sw_if_index)
  50     return NULL;
  51   u32 ti = ipsec_itf_index_by_sw_if_index[sw_if_index];
  52   if (ti == ~0)
  53     return NULL;
  54   return pool_elt_at_index (ipsec_itf_pool, ti);
  55 }
  56
  57 static u8 *
  58 format_ipsec_itf_name (u8 * s, va_list * args)
  59 {
  60   u32 dev_instance = va_arg (*args, u32);
  61   return format (s, "ipsec%d", dev_instance);
  62 }
  63
  64 void
  65 ipsec_itf_adj_unstack (adj_index_t ai)
  66 {
  67   adj_midchain_delegate_unstack (ai);
  68 }
  69
  70 void
  71 ipsec_itf_adj_stack (adj_index_t ai, u32 sai)
  72 {
  73   const vnet_hw_interface_t *hw;
  74
  75   hw = vnet_get_sup_hw_interface (vnet_get_main (), adj_get_sw_if_index (ai));
  76
  77   if (hw->flags & VNET_HW_INTERFACE_FLAG_LINK_UP)
  78     {
  79       const ipsec_sa_t *sa;
  80       fib_prefix_t dst;
  81
  82       sa = ipsec_sa_get (sai);
  83       ip_address_to_fib_prefix (&sa->tunnel.t_dst, &dst);
  84       adj_midchain_delegate_stack (ai, sa->tunnel.t_fib_index, &dst);
  85     }
  86   else
  87     adj_midchain_delegate_unstack (ai);
  88 }
  89
  90 static adj_walk_rc_t
  91 ipsec_itf_adj_stack_cb (adj_index_t ai, void *arg)
  92 {
  93   ipsec_tun_protect_t *itp = arg;
  94
  95   ipsec_itf_adj_stack (ai, itp->itp_out_sa);
  96
  97   return (ADJ_WALK_RC_CONTINUE);
  98 }
  99
 100 static void
 101 ipsec_itf_restack (index_t itpi, const ipsec_itf_t * itf)
 102 {
 103   ipsec_tun_protect_t *itp;
 104   fib_protocol_t proto;
 105
 106   itp = ipsec_tun_protect_get (itpi);
 107
 108   /*
 109    * walk all the adjacencies on the interface and restack them
 110    */
 111   FOR_EACH_FIB_IP_PROTOCOL (proto)
 112   {
 113     adj_nbr_walk (itf->ii_sw_if_index, proto, ipsec_itf_adj_stack_cb, itp);
 114   }
 115 }
 116
 117 static walk_rc_t
 118 ipsec_tun_protect_walk_state_change (index_t itpi, void *arg)
 119 {
 120   const ipsec_itf_t *itf = arg;
 121
 122   ipsec_itf_restack (itpi, itf);
 123
 124   return (WALK_CONTINUE);
 125 }
 126
 127 static clib_error_t *
 128 ipsec_itf_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
 129 {
 130   vnet_hw_interface_t *hi;
 131   ipsec_itf_t *itf;
 132   u32 hw_flags;
 133
 134   hi = vnet_get_hw_interface (vnm, hw_if_index);
 135   hw_flags = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP ?
 136               VNET_HW_INTERFACE_FLAG_LINK_UP : 0);
 137   vnet_hw_interface_set_flags (vnm, hw_if_index, hw_flags);
 138
 139   itf = ipsec_itf_find_by_sw_if_index (hi->sw_if_index);
 140
 141   if (itf)
 142     ipsec_tun_protect_walk_itf (itf->ii_sw_if_index,
 143                                 ipsec_tun_protect_walk_state_change, itf);
 144
 145   return (NULL);
 146 }
 147
 148 static int
 149 ipsec_itf_tunnel_desc (u32 sw_if_index,
 150                        ip46_address_t * src, ip46_address_t * dst, u8 * is_l2)
 151 {
 152   ip46_address_reset (src);
 153   ip46_address_reset (dst);
 154   *is_l2 = 0;
 155
 156   return (0);
 157 }
 158
 159 static u8 *
 160 ipsec_itf_build_rewrite (void)
 161 {
 162   /*
 163    * passing the adj code a NULL rewrite means 'i don't have one cos
 164    * t'other end is unresolved'. That's not the case here. For the ipsec
 165    * tunnel there are just no bytes of encap to apply in the adj.
 166    * So return a zero length rewrite. Encap will be added by a tunnel mode SA.
 167    */
 168   u8 *rewrite = NULL;
 169
 170   vec_validate (rewrite, 0);
 171   vec_reset_length (rewrite);
 172
 173   return (rewrite);
 174 }
 175
 176 static u8 *
 177 ipsec_itf_build_rewrite_i (vnet_main_t * vnm,
 178                            u32 sw_if_index,
 179                            vnet_link_t link_type, const void *dst_address)
 180 {
 181   return (ipsec_itf_build_rewrite ());
 182 }
 183
 184 void
 185 ipsec_itf_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
 186 {
 187   adj_nbr_midchain_update_rewrite
 188     (ai, NULL, NULL, ADJ_FLAG_MIDCHAIN_IP_STACK, ipsec_itf_build_rewrite ());
 189 }
 190
 191 VNET_DEVICE_CLASS (ipsec_itf_device_class) = {
 192   .name = "IPSEC Tunnel",
 193   .format_device_name = format_ipsec_itf_name,
 194   .admin_up_down_function = ipsec_itf_admin_up_down,
 195   .ip_tun_desc = ipsec_itf_tunnel_desc,
 196 };
 197
 198 VNET_HW_INTERFACE_CLASS(ipsec_hw_interface_class) = {
 199   .name = "IPSec",
 200   .build_rewrite = ipsec_itf_build_rewrite_i,
 201   .update_adjacency = ipsec_itf_update_adj,
 202   .flags = VNET_HW_INTERFACE_CLASS_FLAG_P2P,
 203 };
 204 VNET_HW_INTERFACE_CLASS(ipsec_p2mp_hw_interface_class) = {
 205   .name = "IPSec",
 206   .build_rewrite = ipsec_itf_build_rewrite_i,
 207   .update_adjacency = ipsec_itf_update_adj,
 208   .flags = VNET_HW_INTERFACE_CLASS_FLAG_NBMA,
 209 };
 210
 211 /*
 212  * Maintain a bitmap of allocated ipsec_itf instance numbers.
 213  */
 214 #define IPSEC_ITF_MAX_INSTANCE          (16 * 1024)
 215
 216 static u32
 217 ipsec_itf_instance_alloc (u32 want)
 218 {
 219   /*
 220    * Check for dynamically allocated instance number.
 221    */
 222   if (~0 == want)
 223     {
 224       u32 bit;
 225
 226       bit = clib_bitmap_first_clear (ipsec_itf_instances);
 227       if (bit >= IPSEC_ITF_MAX_INSTANCE)
 228         {
 229           return ~0;
 230         }
 231       ipsec_itf_instances = clib_bitmap_set (ipsec_itf_instances, bit, 1);
 232       return bit;
 233     }
 234
 235   /*
 236    * In range?
 237    */
 238   if (want >= IPSEC_ITF_MAX_INSTANCE)
 239     {
 240       return ~0;
 241     }
 242
 243   /*
 244    * Already in use?
 245    */
 246   if (clib_bitmap_get (ipsec_itf_instances, want))
 247     {
 248       return ~0;
 249     }
 250
 251   /*
 252    * Grant allocation request.
 253    */
 254   ipsec_itf_instances = clib_bitmap_set (ipsec_itf_instances, want, 1);
 255
 256   return want;
 257 }
 258
 259 static int
 260 ipsec_itf_instance_free (u32 instance)
 261 {
 262   if (instance >= IPSEC_ITF_MAX_INSTANCE)
 263     {
 264       return -1;
 265     }
 266
 267   if (clib_bitmap_get (ipsec_itf_instances, instance) == 0)
 268     {
 269       return -1;
 270     }
 271
 272   ipsec_itf_instances = clib_bitmap_set (ipsec_itf_instances, instance, 0);
 273   return 0;
 274 }
 275
 276 void
 277 ipsec_itf_reset_tx_nodes (u32 sw_if_index)
 278 {
 279   vnet_feature_modify_end_node (
 280     ip4_main.lookup_main.output_feature_arc_index, sw_if_index,
 281     vlib_get_node_by_name (vlib_get_main (), (u8 *) "ip4-drop")->index);
 282   vnet_feature_modify_end_node (
 283     ip6_main.lookup_main.output_feature_arc_index, sw_if_index,
 284     vlib_get_node_by_name (vlib_get_main (), (u8 *) "ip6-drop")->index);
 285   vnet_feature_modify_end_node (
 286     mpls_main.output_feature_arc_index, sw_if_index,
 287     vlib_get_node_by_name (vlib_get_main (), (u8 *) "mpls-drop")->index);
 288 }
 289
 290 int
 291 ipsec_itf_create (u32 user_instance, tunnel_mode_t mode, u32 * sw_if_indexp)
 292 {
 293   vnet_main_t *vnm = vnet_get_main ();
 294   u32 instance, hw_if_index;
 295   vnet_hw_interface_t *hi;
 296   ipsec_itf_t *ipsec_itf;
 297
 298   ASSERT (sw_if_indexp);
 299
 300   *sw_if_indexp = (u32) ~ 0;
 301
 302   /*
 303    * Allocate a ipsec_itf instance.  Either select on dynamically
 304    * or try to use the desired user_instance number.
 305    */
 306   instance = ipsec_itf_instance_alloc (user_instance);
 307   if (instance == ~0)
 308     return VNET_API_ERROR_INVALID_REGISTRATION;
 309
 310   pool_get (ipsec_itf_pool, ipsec_itf);
 311
 312   /* tunnel index (or instance) */
 313   u32 t_idx = ipsec_itf - ipsec_itf_pool;
 314
 315   ipsec_itf->ii_mode = mode;
 316   ipsec_itf->ii_user_instance = instance;
 317
 318   hw_if_index = vnet_register_interface (vnm,
 319                                          ipsec_itf_device_class.index,
 320                                          ipsec_itf->ii_user_instance,
 321                                          (mode == TUNNEL_MODE_P2P ?
 322                                           ipsec_hw_interface_class.index :
 323                                           ipsec_p2mp_hw_interface_class.index),
 324                                          t_idx);
 325
 326   hi = vnet_get_hw_interface (vnm, hw_if_index);
 327   vnet_sw_interface_set_mtu (vnm, hi->sw_if_index, 9000);
 328
 329   vec_validate_init_empty (ipsec_itf_index_by_sw_if_index, hi->sw_if_index,
 330                            INDEX_INVALID);
 331   ipsec_itf_index_by_sw_if_index[hi->sw_if_index] = t_idx;
 332
 333   ipsec_itf->ii_sw_if_index = *sw_if_indexp = hi->sw_if_index;
 334   ipsec_itf_reset_tx_nodes (hi->sw_if_index);
 335
 336   return 0;
 337 }
 338
 339 int
 340 ipsec_itf_delete (u32 sw_if_index)
 341 {
 342   vnet_main_t *vnm = vnet_get_main ();
 343
 344   if (pool_is_free_index (vnm->interface_main.sw_interfaces, sw_if_index))
 345     return VNET_API_ERROR_INVALID_SW_IF_INDEX;
 346
 347   vnet_hw_interface_t *hw = vnet_get_sup_hw_interface (vnm, sw_if_index);
 348   if (hw == 0 || hw->dev_class_index != ipsec_itf_device_class.index)
 349     return VNET_API_ERROR_INVALID_SW_IF_INDEX;
 350
 351   ipsec_itf_t *ipsec_itf;
 352   ipsec_itf = ipsec_itf_find_by_sw_if_index (sw_if_index);
 353   if (NULL == ipsec_itf)
 354     return VNET_API_ERROR_INVALID_SW_IF_INDEX;
 355
 356   if (ipsec_itf_instance_free (hw->dev_instance) < 0)
 357     return VNET_API_ERROR_INVALID_SW_IF_INDEX;
 358
 359   vnet_reset_interface_l3_output_node (vnm->vlib_main, sw_if_index);
 360
 361   vnet_delete_hw_interface (vnm, hw->hw_if_index);
 362   pool_put (ipsec_itf_pool, ipsec_itf);
 363
 364   return 0;
 365 }
 366
 367 void
 368 ipsec_itf_walk (ipsec_itf_walk_cb_t cb, void *ctx)
 369 {
 370   ipsec_itf_t *itf;
 371
 372   pool_foreach (itf, ipsec_itf_pool)
 373     {
 374       if (WALK_CONTINUE != cb (itf, ctx))
 375         break;
 376     }
 377 }
 378
 379 static clib_error_t *
 380 ipsec_itf_create_cli (vlib_main_t * vm,
 381                       unformat_input_t * input, vlib_cli_command_t * cmd)
 382 {
 383   unformat_input_t _line_input, *line_input = &_line_input;
 384   u32 instance, sw_if_index;
 385   clib_error_t *error;
 386   mac_address_t mac;
 387   int rv;
 388
 389   error = NULL;
 390   instance = sw_if_index = ~0;
 391   mac_address_set_zero (&mac);
 392
 393   if (unformat_user (input, unformat_line_input, line_input))
 394     {
 395       while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
 396         {
 397           if (unformat (line_input, "instance %d", &instance))
 398             ;
 399           else
 400             {
 401               error = clib_error_return (0, "unknown input: %U",
 402                                          format_unformat_error, line_input);
 403               break;
 404             }
 405         }
 406
 407       unformat_free (line_input);
 408
 409       if (error)
 410         return error;
 411     }
 412
 413   rv = ipsec_itf_create (instance, TUNNEL_MODE_P2P, &sw_if_index);
 414
 415   if (rv)
 416     return clib_error_return (0, "iPSec interface create failed");
 417
 418   vlib_cli_output (vm, "%U\n", format_vnet_sw_if_index_name, vnet_get_main (),
 419                    sw_if_index);
 420   return 0;
 421 }
 422
 423 /*?
 424  * Create a IPSec interface.
 425  *
 426  * @cliexpar
 427  * The following two command syntaxes are equivalent:
 428  * @cliexcmd{ipsec itf create [instance <instance>]}
 429  * Example of how to create a ipsec interface:
 430  * @cliexcmd{ipsec itf create}
 431 ?*/
 432 VLIB_CLI_COMMAND (ipsec_itf_create_command, static) = {
 433   .path = "ipsec itf create",
 434   .short_help = "ipsec itf create [instance <instance>]",
 435   .function = ipsec_itf_create_cli,
 436 };
 437
 438 static clib_error_t *
 439 ipsec_itf_delete_cli (vlib_main_t * vm,
 440                       unformat_input_t * input, vlib_cli_command_t * cmd)
 441 {
 442   vnet_main_t *vnm;
 443   u32 sw_if_index;
 444   int rv;
 445
 446   vnm = vnet_get_main ();
 447   sw_if_index = ~0;
 448
 449   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 450     {
 451       if (unformat
 452           (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index))
 453         ;
 454       else
 455         break;
 456     }
 457
 458   if (~0 != sw_if_index)
 459     {
 460       rv = ipsec_itf_delete (sw_if_index);
 461
 462       if (rv)
 463         return clib_error_return (0, "ipsec interface delete failed");
 464     }
 465   else
 466     return clib_error_return (0, "no such interface: %U",
 467                               format_unformat_error, input);
 468
 469   return 0;
 470 }
 471
 472 /*?
 473  * Delete a IPSEC_ITF interface.
 474  *
 475  * @cliexpar
 476  * The following two command syntaxes are equivalent:
 477  * @cliexcmd{ipsec itf delete <interface>}
 478  * Example of how to create a ipsec_itf interface:
 479  * @cliexcmd{ipsec itf delete ipsec0}
 480 ?*/
 481 VLIB_CLI_COMMAND (ipsec_itf_delete_command, static) = {
 482   .path = "ipsec itf delete",
 483   .short_help = "ipsec itf delete <interface>",
 484   .function = ipsec_itf_delete_cli,
 485 };
 486
 487 static clib_error_t *
 488 ipsec_interface_show (vlib_main_t * vm,
 489                       unformat_input_t * input, vlib_cli_command_t * cmd)
 490 {
 491   index_t ii;
 492
 493   pool_foreach_index (ii, ipsec_itf_pool)
 494    {
 495     vlib_cli_output (vm, "%U", format_ipsec_itf, ii);
 496   }
 497
 498   return NULL;
 499 }
 500
 501 /**
 502  * show IPSEC tunnel protection hash tables
 503  */
 504 VLIB_CLI_COMMAND (ipsec_interface_show_node, static) =
 505 {
 506   .path = "show ipsec interface",
 507   .function = ipsec_interface_show,
 508   .short_help =  "show ipsec interface",
 509 };
 510
 511 /*
 512  * fd.io coding-style-patch-verification: ON
 513  *
 514  * Local Variables:
 515  * eval: (c-set-style "gnu")
 516  * End:
 517  */