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
  25 /* bitmap of Allocated IPSEC_ITF instances */
  26 static uword *ipsec_itf_instances;
  27
  28 /* pool of interfaces */
  29 static ipsec_itf_t *ipsec_itf_pool;
  30
  31 static u32 *ipsec_itf_index_by_sw_if_index;
  32
  33 ipsec_itf_t *
  34 ipsec_itf_get (index_t ii)
  35 {
  36   return (pool_elt_at_index (ipsec_itf_pool, ii));
  37 }
  38
  39 static ipsec_itf_t *
  40 ipsec_itf_find_by_sw_if_index (u32 sw_if_index)
  41 {
  42   if (vec_len (ipsec_itf_index_by_sw_if_index) <= sw_if_index)
  43     return NULL;
  44   u32 ti = ipsec_itf_index_by_sw_if_index[sw_if_index];
  45   if (ti == ~0)
  46     return NULL;
  47   return pool_elt_at_index (ipsec_itf_pool, ti);
  48 }
  49
  50 static u8 *
  51 format_ipsec_itf_name (u8 * s, va_list * args)
  52 {
  53   u32 dev_instance = va_arg (*args, u32);
  54   return format (s, "ipsec%d", dev_instance);
  55 }
  56
  57 void
  58 ipsec_itf_adj_unstack (adj_index_t ai)
  59 {
  60   adj_midchain_delegate_unstack (ai);
  61 }
  62
  63 void
  64 ipsec_itf_adj_stack (adj_index_t ai, u32 sai)
  65 {
  66   const vnet_hw_interface_t *hw;
  67
  68   hw = vnet_get_sup_hw_interface (vnet_get_main (), adj_get_sw_if_index (ai));
  69
  70   if (hw->flags & VNET_HW_INTERFACE_FLAG_LINK_UP)
  71     {
  72       const ipsec_sa_t *sa;
  73
  74       sa = ipsec_sa_get (sai);
  75
  76       /* *INDENT-OFF* */
  77       const fib_prefix_t dst = {
  78         .fp_len = (ipsec_sa_is_set_IS_TUNNEL_V6(sa) ? 128 : 32),
  79         .fp_proto = (ipsec_sa_is_set_IS_TUNNEL_V6(sa)?
  80                      FIB_PROTOCOL_IP6 :
  81                      FIB_PROTOCOL_IP4),
  82         .fp_addr = sa->tunnel_dst_addr,
  83       };
  84       /* *INDENT-ON* */
  85
  86       adj_midchain_delegate_stack (ai, sa->tx_fib_index, &dst);
  87     }
  88   else
  89     adj_midchain_delegate_unstack (ai);
  90 }
  91
  92 static adj_walk_rc_t
  93 ipsec_itf_adj_stack_cb (adj_index_t ai, void *arg)
  94 {
  95   ipsec_tun_protect_t *itp = arg;
  96
  97   ipsec_itf_adj_stack (ai, itp->itp_out_sa);
  98
  99   return (ADJ_WALK_RC_CONTINUE);
 100 }
 101
 102 static void
 103 ipsec_itf_restack (index_t itpi, const ipsec_itf_t * itf)
 104 {
 105   ipsec_tun_protect_t *itp;
 106   fib_protocol_t proto;
 107
 108   itp = ipsec_tun_protect_get (itpi);
 109
 110   /*
 111    * walk all the adjacencies on the interface and restack them
 112    */
 113   FOR_EACH_FIB_IP_PROTOCOL (proto)
 114   {
 115     adj_nbr_walk (itf->ii_sw_if_index, proto, ipsec_itf_adj_stack_cb, itp);
 116   }
 117 }
 118
 119 static walk_rc_t
 120 ipsec_tun_protect_walk_state_change (index_t itpi, void *arg)
 121 {
 122   const ipsec_itf_t *itf = arg;
 123
 124   ipsec_itf_restack (itpi, itf);
 125
 126   return (WALK_CONTINUE);
 127 }
 128
 129 static clib_error_t *
 130 ipsec_itf_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
 131 {
 132   vnet_hw_interface_t *hi;
 133   ipsec_itf_t *itf;
 134   u32 hw_flags;
 135
 136   hi = vnet_get_hw_interface (vnm, hw_if_index);
 137   hw_flags = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP ?
 138               VNET_HW_INTERFACE_FLAG_LINK_UP : 0);
 139   vnet_hw_interface_set_flags (vnm, hw_if_index, hw_flags);
 140
 141   itf = ipsec_itf_find_by_sw_if_index (hi->sw_if_index);
 142
 143   if (itf)
 144     ipsec_tun_protect_walk_itf (itf->ii_sw_if_index,
 145                                 ipsec_tun_protect_walk_state_change, itf);
 146
 147   return (NULL);
 148 }
 149
 150 static int
 151 ipsec_itf_tunnel_desc (u32 sw_if_index,
 152                        ip46_address_t * src, ip46_address_t * dst, u8 * is_l2)
 153 {
 154   ip46_address_reset (src);
 155   ip46_address_reset (dst);
 156   *is_l2 = 0;
 157
 158   return (0);
 159 }
 160
 161 static u8 *
 162 ipsec_itf_build_rewrite (void)
 163 {
 164   /*
 165    * passing the adj code a NULL rewrite means 'i don't have one cos
 166    * t'other end is unresolved'. That's not the case here. For the ipsec
 167    * tunnel there are just no bytes of encap to apply in the adj.
 168    * So return a zero length rewrite. Encap will be added by a tunnel mode SA.
 169    */
 170   u8 *rewrite = NULL;
 171
 172   vec_validate (rewrite, 0);
 173   vec_reset_length (rewrite);
 174
 175   return (rewrite);
 176 }
 177
 178 static u8 *
 179 ipsec_itf_build_rewrite_i (vnet_main_t * vnm,
 180                            u32 sw_if_index,
 181                            vnet_link_t link_type, const void *dst_address)
 182 {
 183   return (ipsec_itf_build_rewrite ());
 184 }
 185
 186 void
 187 ipsec_itf_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
 188 {
 189   adj_nbr_midchain_update_rewrite
 190     (ai, NULL, NULL, ADJ_FLAG_MIDCHAIN_IP_STACK, ipsec_itf_build_rewrite ());
 191 }
 192
 193 /* *INDENT-OFF* */
 194 VNET_DEVICE_CLASS (ipsec_itf_device_class) = {
 195   .name = "IPSEC Tunnel",
 196   .format_device_name = format_ipsec_itf_name,
 197   .admin_up_down_function = ipsec_itf_admin_up_down,
 198   .ip_tun_desc = ipsec_itf_tunnel_desc,
 199 };
 200
 201 VNET_HW_INTERFACE_CLASS(ipsec_hw_interface_class) = {
 202   .name = "IPSec",
 203   .build_rewrite = ipsec_itf_build_rewrite_i,
 204   .update_adjacency = ipsec_itf_update_adj,
 205   .flags = VNET_HW_INTERFACE_CLASS_FLAG_P2P,
 206 };
 207 VNET_HW_INTERFACE_CLASS(ipsec_p2mp_hw_interface_class) = {
 208   .name = "IPSec",
 209   .build_rewrite = ipsec_itf_build_rewrite_i,
 210   .update_adjacency = ipsec_itf_update_adj,
 211 };
 212 /* *INDENT-ON* */
 213
 214 /*
 215  * Maintain a bitmap of allocated ipsec_itf instance numbers.
 216  */
 217 #define IPSEC_ITF_MAX_INSTANCE          (16 * 1024)
 218
 219 static u32
 220 ipsec_itf_instance_alloc (u32 want)
 221 {
 222   /*
 223    * Check for dynamically allocated instance number.
 224    */
 225   if (~0 == want)
 226     {
 227       u32 bit;
 228
 229       bit = clib_bitmap_first_clear (ipsec_itf_instances);
 230       if (bit >= IPSEC_ITF_MAX_INSTANCE)
 231         {
 232           return ~0;
 233         }
 234       ipsec_itf_instances = clib_bitmap_set (ipsec_itf_instances, bit, 1);
 235       return bit;
 236     }
 237
 238   /*
 239    * In range?
 240    */
 241   if (want >= IPSEC_ITF_MAX_INSTANCE)
 242     {
 243       return ~0;
 244     }
 245
 246   /*
 247    * Already in use?
 248    */
 249   if (clib_bitmap_get (ipsec_itf_instances, want))
 250     {
 251       return ~0;
 252     }
 253
 254   /*
 255    * Grant allocation request.
 256    */
 257   ipsec_itf_instances = clib_bitmap_set (ipsec_itf_instances, want, 1);
 258
 259   return want;
 260 }
 261
 262 static int
 263 ipsec_itf_instance_free (u32 instance)
 264 {
 265   if (instance >= IPSEC_ITF_MAX_INSTANCE)
 266     {
 267       return -1;
 268     }
 269
 270   if (clib_bitmap_get (ipsec_itf_instances, instance) == 0)
 271     {
 272       return -1;
 273     }
 274
 275   ipsec_itf_instances = clib_bitmap_set (ipsec_itf_instances, instance, 0);
 276   return 0;
 277 }
 278
 279 int
 280 ipsec_itf_create (u32 user_instance, tunnel_mode_t mode, u32 * sw_if_indexp)
 281 {
 282   vnet_main_t *vnm = vnet_get_main ();
 283   u32 instance, hw_if_index;
 284   vnet_hw_interface_t *hi;
 285   ipsec_itf_t *ipsec_itf;
 286
 287   ASSERT (sw_if_indexp);
 288
 289   *sw_if_indexp = (u32) ~ 0;
 290
 291   /*
 292    * Allocate a ipsec_itf instance.  Either select on dynamically
 293    * or try to use the desired user_instance number.
 294    */
 295   instance = ipsec_itf_instance_alloc (user_instance);
 296   if (instance == ~0)
 297     return VNET_API_ERROR_INVALID_REGISTRATION;
 298
 299   pool_get (ipsec_itf_pool, ipsec_itf);
 300
 301   /* tunnel index (or instance) */
 302   u32 t_idx = ipsec_itf - ipsec_itf_pool;
 303
 304   ipsec_itf->ii_mode = mode;
 305   ipsec_itf->ii_user_instance = instance;
 306
 307   hw_if_index = vnet_register_interface (vnm,
 308                                          ipsec_itf_device_class.index,
 309                                          ipsec_itf->ii_user_instance,
 310                                          (mode == TUNNEL_MODE_P2P ?
 311                                           ipsec_hw_interface_class.index :
 312                                           ipsec_p2mp_hw_interface_class.index),
 313                                          t_idx);
 314
 315   hi = vnet_get_hw_interface (vnm, hw_if_index);
 316
 317   vec_validate_init_empty (ipsec_itf_index_by_sw_if_index, hi->sw_if_index,
 318                            INDEX_INVALID);
 319   ipsec_itf_index_by_sw_if_index[hi->sw_if_index] = t_idx;
 320
 321   ipsec_itf->ii_sw_if_index = *sw_if_indexp = hi->sw_if_index;
 322
 323   return 0;
 324 }
 325
 326 int
 327 ipsec_itf_delete (u32 sw_if_index)
 328 {
 329   vnet_main_t *vnm = vnet_get_main ();
 330
 331   if (pool_is_free_index (vnm->interface_main.sw_interfaces, sw_if_index))
 332     return VNET_API_ERROR_INVALID_SW_IF_INDEX;
 333
 334   vnet_hw_interface_t *hw = vnet_get_sup_hw_interface (vnm, sw_if_index);
 335   if (hw == 0 || hw->dev_class_index != ipsec_itf_device_class.index)
 336     return VNET_API_ERROR_INVALID_SW_IF_INDEX;
 337
 338   ipsec_itf_t *ipsec_itf;
 339   ipsec_itf = ipsec_itf_find_by_sw_if_index (sw_if_index);
 340   if (NULL == ipsec_itf)
 341     return VNET_API_ERROR_INVALID_SW_IF_INDEX;
 342
 343   if (ipsec_itf_instance_free (hw->dev_instance) < 0)
 344     return VNET_API_ERROR_INVALID_SW_IF_INDEX;
 345
 346   vnet_delete_hw_interface (vnm, hw->hw_if_index);
 347   pool_put (ipsec_itf_pool, ipsec_itf);
 348
 349   return 0;
 350 }
 351
 352 static clib_error_t *
 353 ipsec_itf_create_cli (vlib_main_t * vm,
 354                       unformat_input_t * input, vlib_cli_command_t * cmd)
 355 {
 356   unformat_input_t _line_input, *line_input = &_line_input;
 357   u32 instance, sw_if_index;
 358   clib_error_t *error;
 359   mac_address_t mac;
 360   int rv;
 361
 362   error = NULL;
 363   instance = sw_if_index = ~0;
 364   mac_address_set_zero (&mac);
 365
 366   if (unformat_user (input, unformat_line_input, line_input))
 367     {
 368       while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
 369         {
 370           if (unformat (line_input, "instance %d", &instance))
 371             ;
 372           else
 373             {
 374               error = clib_error_return (0, "unknown input: %U",
 375                                          format_unformat_error, line_input);
 376               break;
 377             }
 378         }
 379
 380       unformat_free (line_input);
 381
 382       if (error)
 383         return error;
 384     }
 385
 386   rv = ipsec_itf_create (instance, TUNNEL_MODE_P2P, &sw_if_index);
 387
 388   if (rv)
 389     return clib_error_return (0, "iPSec interface create failed");
 390
 391   vlib_cli_output (vm, "%U\n", format_vnet_sw_if_index_name, vnet_get_main (),
 392                    sw_if_index);
 393   return 0;
 394 }
 395
 396 /*?
 397  * Create a IPSec interface.
 398  *
 399  * @cliexpar
 400  * The following two command syntaxes are equivalent:
 401  * @cliexcmd{ipsec itf create [instance <instance>]}
 402  * Example of how to create a ipsec interface:
 403  * @cliexcmd{ipsec itf create}
 404 ?*/
 405 /* *INDENT-OFF* */
 406 VLIB_CLI_COMMAND (ipsec_itf_create_command, static) = {
 407   .path = "ipsec itf create",
 408   .short_help = "ipsec itf create [instance <instance>]",
 409   .function = ipsec_itf_create_cli,
 410 };
 411 /* *INDENT-ON* */
 412
 413 static clib_error_t *
 414 ipsec_itf_delete_cli (vlib_main_t * vm,
 415                       unformat_input_t * input, vlib_cli_command_t * cmd)
 416 {
 417   vnet_main_t *vnm;
 418   u32 sw_if_index;
 419   int rv;
 420
 421   vnm = vnet_get_main ();
 422   sw_if_index = ~0;
 423
 424   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 425     {
 426       if (unformat
 427           (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index))
 428         ;
 429       else
 430         break;
 431     }
 432
 433   if (~0 != sw_if_index)
 434     {
 435       rv = ipsec_itf_delete (sw_if_index);
 436
 437       if (rv)
 438         return clib_error_return (0, "ipsec interface delete failed");
 439     }
 440   else
 441     return clib_error_return (0, "no such interface: %U",
 442                               format_unformat_error, input);
 443
 444   return 0;
 445 }
 446
 447 /*?
 448  * Delete a IPSEC_ITF interface.
 449  *
 450  * @cliexpar
 451  * The following two command syntaxes are equivalent:
 452  * @cliexcmd{ipsec itf delete <interface>}
 453  * Example of how to create a ipsec_itf interface:
 454  * @cliexcmd{ipsec itf delete ipsec0}
 455 ?*/
 456 /* *INDENT-OFF* */
 457 VLIB_CLI_COMMAND (ipsec_itf_delete_command, static) = {
 458   .path = "ipsec itf delete",
 459   .short_help = "ipsec itf delete <interface>",
 460   .function = ipsec_itf_delete_cli,
 461 };
 462 /* *INDENT-ON* */
 463
 464 static clib_error_t *
 465 ipsec_interface_show (vlib_main_t * vm,
 466                       unformat_input_t * input, vlib_cli_command_t * cmd)
 467 {
 468   index_t ii;
 469
 470   /* *INDENT-OFF* */
 471   pool_foreach_index (ii, ipsec_itf_pool,
 472   ({
 473     vlib_cli_output (vm, "%U", format_ipsec_itf, ii);
 474   }));
 475   /* *INDENT-ON* */
 476
 477   return NULL;
 478 }
 479
 480 /**
 481  * show IPSEC tunnel protection hash tables
 482  */
 483 /* *INDENT-OFF* */
 484 VLIB_CLI_COMMAND (ipsec_interface_show_node, static) =
 485 {
 486   .path = "show ipsec interface",
 487   .function = ipsec_interface_show,
 488   .short_help =  "show ipsec interface",
 489 };
 490 /* *INDENT-ON* */
 491
 492 /*
 493  * fd.io coding-style-patch-verification: ON
 494  *
 495  * Local Variables:
 496  * eval: (c-set-style "gnu")
 497  * End:
 498  */