src/vnet/ipsec/ipsec_input.c

   1 /*
   2  * decap.c : IPSec tunnel decapsulation
   3  *
   4  * Copyright (c) 2015 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/vnet.h>
  19 #include <vnet/api_errno.h>
  20 #include <vnet/ip/ip.h>
  21 #include <vnet/feature/feature.h>
  22
  23 #include <vnet/ipsec/ipsec.h>
  24 #include <vnet/ipsec/esp.h>
  25 #include <vnet/ipsec/ah.h>
  26
  27 #define foreach_ipsec_input_error                   \
  28  _(RX_PKTS, "IPSEC pkts received")                  \
  29  _(DECRYPTION_FAILED, "IPSEC decryption failed")
  30
  31 typedef enum
  32 {
  33 #define _(sym,str) IPSEC_INPUT_ERROR_##sym,
  34   foreach_ipsec_input_error
  35 #undef _
  36     IPSEC_INPUT_N_ERROR,
  37 } ipsec_input_error_t;
  38
  39 static char *ipsec_input_error_strings[] = {
  40 #define _(sym,string) string,
  41   foreach_ipsec_input_error
  42 #undef _
  43 };
  44
  45 typedef struct
  46 {
  47   u32 sa_id;
  48   u32 spi;
  49   u32 seq;
  50 } ipsec_input_trace_t;
  51
  52 /* packet trace format function */
  53 static u8 *
  54 format_ipsec_input_trace (u8 * s, va_list * args)
  55 {
  56   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  57   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  58   ipsec_input_trace_t *t = va_arg (*args, ipsec_input_trace_t *);
  59
  60   if (t->spi == 0 && t->seq == 0)
  61     {
  62       s = format (s, "esp: no esp packet");
  63       return s;
  64     }
  65
  66   if (t->sa_id != 0)
  67     {
  68       s = format (s, "esp: sa_id %u spi %u seq %u", t->sa_id, t->spi, t->seq);
  69     }
  70   else
  71     {
  72       s = format (s, "esp: no sa spi %u seq %u", t->spi, t->seq);
  73     }
  74   return s;
  75 }
  76
  77 always_inline ipsec_policy_t *
  78 ipsec_input_protect_policy_match (ipsec_spd_t * spd, u32 sa, u32 da, u32 spi)
  79 {
  80   ipsec_main_t *im = &ipsec_main;
  81   ipsec_policy_t *p;
  82   ipsec_sa_t *s;
  83   u32 *i;
  84
  85   vec_foreach (i, spd->ipv4_inbound_protect_policy_indices)
  86   {
  87     p = pool_elt_at_index (spd->policies, *i);
  88     s = pool_elt_at_index (im->sad, p->sa_index);
  89
  90     if (spi != s->spi)
  91       continue;
  92
  93     if (s->is_tunnel)
  94       {
  95         if (da != clib_net_to_host_u32 (s->tunnel_dst_addr.ip4.as_u32))
  96           continue;
  97
  98         if (sa != clib_net_to_host_u32 (s->tunnel_src_addr.ip4.as_u32))
  99           continue;
 100
 101         return p;
 102       }
 103
 104     if (da < clib_net_to_host_u32 (p->laddr.start.ip4.as_u32))
 105       continue;
 106
 107     if (da > clib_net_to_host_u32 (p->laddr.stop.ip4.as_u32))
 108       continue;
 109
 110     if (sa < clib_net_to_host_u32 (p->raddr.start.ip4.as_u32))
 111       continue;
 112
 113     if (sa > clib_net_to_host_u32 (p->raddr.stop.ip4.as_u32))
 114       continue;
 115
 116     return p;
 117   }
 118   return 0;
 119 }
 120
 121 always_inline uword
 122 ip6_addr_match_range (ip6_address_t * a, ip6_address_t * la,
 123                       ip6_address_t * ua)
 124 {
 125   if ((memcmp (a->as_u64, la->as_u64, 2 * sizeof (u64)) >= 0) &&
 126       (memcmp (a->as_u64, ua->as_u64, 2 * sizeof (u64)) <= 0))
 127     return 1;
 128   return 0;
 129 }
 130
 131 always_inline ipsec_policy_t *
 132 ipsec6_input_protect_policy_match (ipsec_spd_t * spd,
 133                                    ip6_address_t * sa,
 134                                    ip6_address_t * da, u32 spi)
 135 {
 136   ipsec_main_t *im = &ipsec_main;
 137   ipsec_policy_t *p;
 138   ipsec_sa_t *s;
 139   u32 *i;
 140
 141   vec_foreach (i, spd->ipv6_inbound_protect_policy_indices)
 142   {
 143     p = pool_elt_at_index (spd->policies, *i);
 144     s = pool_elt_at_index (im->sad, p->sa_index);
 145
 146     if (spi != s->spi)
 147       continue;
 148
 149     if (s->is_tunnel)
 150       {
 151         if (!ip6_address_is_equal (sa, &s->tunnel_src_addr.ip6))
 152           continue;
 153
 154         if (!ip6_address_is_equal (da, &s->tunnel_dst_addr.ip6))
 155           continue;
 156
 157         return p;
 158       }
 159
 160     if (!ip6_addr_match_range (sa, &p->raddr.start.ip6, &p->raddr.stop.ip6))
 161       continue;
 162
 163     if (!ip6_addr_match_range (da, &p->laddr.start.ip6, &p->laddr.stop.ip6))
 164       continue;
 165
 166     return p;
 167   }
 168   return 0;
 169 }
 170
 171 static vlib_node_registration_t ipsec4_input_node;
 172
 173 static uword
 174 ipsec4_input_node_fn (vlib_main_t * vm,
 175                       vlib_node_runtime_t * node, vlib_frame_t * from_frame)
 176 {
 177   u32 n_left_from, *from, next_index, *to_next;
 178   ipsec_main_t *im = &ipsec_main;
 179
 180   from = vlib_frame_vector_args (from_frame);
 181   n_left_from = from_frame->n_vectors;
 182
 183   next_index = node->cached_next_index;
 184
 185   while (n_left_from > 0)
 186     {
 187       u32 n_left_to_next;
 188
 189       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 190
 191       while (n_left_from > 0 && n_left_to_next > 0)
 192         {
 193           u32 bi0, next0;
 194           vlib_buffer_t *b0;
 195           ip4_header_t *ip0;
 196           esp_header_t *esp0;
 197           ah_header_t *ah0;
 198           ip4_ipsec_config_t *c0;
 199           ipsec_spd_t *spd0;
 200           ipsec_policy_t *p0 = 0;
 201
 202           bi0 = to_next[0] = from[0];
 203           from += 1;
 204           n_left_from -= 1;
 205           to_next += 1;
 206           n_left_to_next -= 1;
 207
 208           b0 = vlib_get_buffer (vm, bi0);
 209           b0->flags |= VNET_BUFFER_F_IS_IP4;
 210           b0->flags &= ~VNET_BUFFER_F_IS_IP6;
 211           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 212
 213           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 214
 215           ip0 = vlib_buffer_get_current (b0);
 216
 217           if (PREDICT_TRUE
 218               (ip0->protocol == IP_PROTOCOL_IPSEC_ESP
 219                || ip0->protocol == IP_PROTOCOL_UDP))
 220             {
 221 #if 0
 222               clib_warning
 223                 ("packet received from %U to %U spi %u size %u spd_id %u",
 224                  format_ip4_address, ip0->src_address.as_u8,
 225                  format_ip4_address, ip0->dst_address.as_u8,
 226                  clib_net_to_host_u32 (esp0->spi),
 227                  clib_net_to_host_u16 (ip0->length), spd0->id);
 228 #endif
 229
 230               esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 231               if (PREDICT_FALSE (ip0->protocol == IP_PROTOCOL_UDP))
 232                 {
 233                   esp0 =
 234                     (esp_header_t *) ((u8 *) esp0 + sizeof (udp_header_t));
 235                 }
 236               /* FIXME TODO missing check whether there is enough data inside
 237                * IP/UDP to contain ESP header & stuff ? */
 238               p0 = ipsec_input_protect_policy_match (spd0,
 239                                                      clib_net_to_host_u32
 240                                                      (ip0->src_address.
 241                                                       as_u32),
 242                                                      clib_net_to_host_u32
 243                                                      (ip0->dst_address.
 244                                                       as_u32),
 245                                                      clib_net_to_host_u32
 246                                                      (esp0->spi));
 247
 248               if (PREDICT_TRUE (p0 != 0))
 249                 {
 250                   p0->counter.packets++;
 251                   p0->counter.bytes += clib_net_to_host_u16 (ip0->length);
 252                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 253                   vnet_buffer (b0)->ipsec.flags = 0;
 254                   next0 = im->esp4_decrypt_next_index;
 255                   vlib_buffer_advance (b0, ((u8 *) esp0 - (u8 *) ip0));
 256                   goto trace0;
 257                 }
 258
 259               /* FIXME bypass and discard */
 260             trace0:
 261               if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 262                 {
 263                   ipsec_input_trace_t *tr =
 264                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 265                   if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP ||
 266                       ip0->protocol == IP_PROTOCOL_UDP)
 267                     {
 268                       if (p0)
 269                         tr->sa_id = p0->sa_id;
 270                       tr->spi = clib_host_to_net_u32 (esp0->spi);
 271                       tr->seq = clib_host_to_net_u32 (esp0->seq);
 272                     }
 273                 }
 274
 275             }
 276
 277
 278           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_AH))
 279             {
 280               ah0 = (ah_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 281               p0 = ipsec_input_protect_policy_match (spd0,
 282                                                      clib_net_to_host_u32
 283                                                      (ip0->src_address.
 284                                                       as_u32),
 285                                                      clib_net_to_host_u32
 286                                                      (ip0->dst_address.
 287                                                       as_u32),
 288                                                      clib_net_to_host_u32
 289                                                      (ah0->spi));
 290
 291               if (PREDICT_TRUE (p0 != 0))
 292                 {
 293                   p0->counter.packets++;
 294                   p0->counter.bytes += clib_net_to_host_u16 (ip0->length);
 295                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 296                   vnet_buffer (b0)->ipsec.flags = 0;
 297                   next0 = im->ah4_decrypt_next_index;
 298                   goto trace1;
 299                 }
 300               /* FIXME bypass and discard */
 301             trace1:
 302               if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 303                 {
 304                   ipsec_input_trace_t *tr =
 305                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 306                   if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
 307                     {
 308                       if (p0)
 309                         tr->sa_id = p0->sa_id;
 310                       tr->spi = clib_host_to_net_u32 (ah0->spi);
 311                       tr->seq = clib_host_to_net_u32 (ah0->seq_no);
 312                     }
 313                 }
 314             }
 315
 316           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 317                                            to_next, n_left_to_next, bi0,
 318                                            next0);
 319         }
 320       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 321     }
 322   vlib_node_increment_counter (vm, ipsec4_input_node.index,
 323                                IPSEC_INPUT_ERROR_RX_PKTS,
 324                                from_frame->n_vectors);
 325
 326   return from_frame->n_vectors;
 327 }
 328
 329
 330 /* *INDENT-OFF* */
 331 VLIB_REGISTER_NODE (ipsec4_input_node,static) = {
 332   .function = ipsec4_input_node_fn,
 333   .name = "ipsec4-input",
 334   .vector_size = sizeof (u32),
 335   .format_trace = format_ipsec_input_trace,
 336   .type = VLIB_NODE_TYPE_INTERNAL,
 337
 338   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 339   .error_strings = ipsec_input_error_strings,
 340
 341   .n_next_nodes = IPSEC_INPUT_N_NEXT,
 342   .next_nodes = {
 343 #define _(s,n) [IPSEC_INPUT_NEXT_##s] = n,
 344     foreach_ipsec_input_next
 345 #undef _
 346   },
 347 };
 348 /* *INDENT-ON* */
 349
 350 VLIB_NODE_FUNCTION_MULTIARCH (ipsec4_input_node, ipsec4_input_node_fn);
 351
 352 static vlib_node_registration_t ipsec6_input_node;
 353
 354 static uword
 355 ipsec6_input_node_fn (vlib_main_t * vm,
 356                       vlib_node_runtime_t * node, vlib_frame_t * from_frame)
 357 {
 358   u32 n_left_from, *from, next_index, *to_next;
 359   ipsec_main_t *im = &ipsec_main;
 360
 361   from = vlib_frame_vector_args (from_frame);
 362   n_left_from = from_frame->n_vectors;
 363
 364   next_index = node->cached_next_index;
 365
 366   while (n_left_from > 0)
 367     {
 368       u32 n_left_to_next;
 369
 370       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 371
 372       while (n_left_from > 0 && n_left_to_next > 0)
 373         {
 374           u32 bi0, next0;
 375           vlib_buffer_t *b0;
 376           ip6_header_t *ip0;
 377           esp_header_t *esp0;
 378           ip4_ipsec_config_t *c0;
 379           ipsec_spd_t *spd0;
 380           ipsec_policy_t *p0 = 0;
 381           ah_header_t *ah0;
 382           u32 header_size = sizeof (ip0[0]);
 383
 384           bi0 = to_next[0] = from[0];
 385           from += 1;
 386           n_left_from -= 1;
 387           to_next += 1;
 388           n_left_to_next -= 1;
 389
 390           b0 = vlib_get_buffer (vm, bi0);
 391           b0->flags |= VNET_BUFFER_F_IS_IP6;
 392           b0->flags &= ~VNET_BUFFER_F_IS_IP4;
 393           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 394
 395           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 396
 397           ip0 = vlib_buffer_get_current (b0);
 398           esp0 = (esp_header_t *) ((u8 *) ip0 + header_size);
 399           ah0 = (ah_header_t *) ((u8 *) ip0 + header_size);
 400
 401           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
 402             {
 403 #if 0
 404               clib_warning
 405                 ("packet received from %U to %U spi %u size %u spd_id %u",
 406                  format_ip6_address, &ip0->src_address, format_ip6_address,
 407                  &ip0->dst_address, clib_net_to_host_u32 (esp0->spi),
 408                  clib_net_to_host_u16 (ip0->payload_length) + header_size,
 409                  spd0->id);
 410 #endif
 411               p0 = ipsec6_input_protect_policy_match (spd0,
 412                                                       &ip0->src_address,
 413                                                       &ip0->dst_address,
 414                                                       clib_net_to_host_u32
 415                                                       (esp0->spi));
 416
 417               if (PREDICT_TRUE (p0 != 0))
 418                 {
 419                   p0->counter.packets++;
 420                   p0->counter.bytes +=
 421                     clib_net_to_host_u16 (ip0->payload_length);
 422                   p0->counter.bytes += header_size;
 423                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 424                   vnet_buffer (b0)->ipsec.flags = 0;
 425                   next0 = im->esp6_decrypt_next_index;
 426                   vlib_buffer_advance (b0, header_size);
 427                   goto trace0;
 428                 }
 429             }
 430           else if (ip0->protocol == IP_PROTOCOL_IPSEC_AH)
 431             {
 432               p0 = ipsec6_input_protect_policy_match (spd0,
 433                                                       &ip0->src_address,
 434                                                       &ip0->dst_address,
 435                                                       clib_net_to_host_u32
 436                                                       (ah0->spi));
 437
 438               if (PREDICT_TRUE (p0 != 0))
 439                 {
 440                   p0->counter.packets++;
 441                   p0->counter.bytes +=
 442                     clib_net_to_host_u16 (ip0->payload_length);
 443                   p0->counter.bytes += header_size;
 444                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 445                   vnet_buffer (b0)->ipsec.flags = 0;
 446                   next0 = im->ah6_decrypt_next_index;
 447                   goto trace0;
 448                 }
 449             }
 450
 451         trace0:
 452           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 453             {
 454               ipsec_input_trace_t *tr =
 455                 vlib_add_trace (vm, node, b0, sizeof (*tr));
 456               if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
 457                 {
 458                   if (p0)
 459                     tr->sa_id = p0->sa_id;
 460                   tr->spi = clib_host_to_net_u32 (esp0->spi);
 461                   tr->seq = clib_host_to_net_u32 (esp0->seq);
 462                 }
 463             }
 464
 465           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 466                                            n_left_to_next, bi0, next0);
 467         }
 468       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 469     }
 470   vlib_node_increment_counter (vm, ipsec6_input_node.index,
 471                                IPSEC_INPUT_ERROR_RX_PKTS,
 472                                from_frame->n_vectors);
 473
 474   return from_frame->n_vectors;
 475 }
 476
 477
 478 /* *INDENT-OFF* */
 479 VLIB_REGISTER_NODE (ipsec6_input_node,static) = {
 480   .function = ipsec6_input_node_fn,
 481   .name = "ipsec6-input",
 482   .vector_size = sizeof (u32),
 483   .format_trace = format_ipsec_input_trace,
 484   .type = VLIB_NODE_TYPE_INTERNAL,
 485
 486   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 487   .error_strings = ipsec_input_error_strings,
 488
 489   .sibling_of = "ipsec4-input",
 490 };
 491 /* *INDENT-ON* */
 492
 493 VLIB_NODE_FUNCTION_MULTIARCH (ipsec6_input_node, ipsec6_input_node_fn);
 494 /*
 495  * fd.io coding-style-patch-verification: ON
 496  *
 497  * Local Variables:
 498  * eval: (c-set-style "gnu")
 499  * End:
 500  */