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 #include <vnet/ipsec/ipsec_io.h>
  27
  28 #define foreach_ipsec_input_error               \
  29 _(RX_PKTS, "IPSEC pkts received")               \
  30 _(RX_MATCH_PKTS, "IPSEC pkts matched")
  31
  32 typedef enum
  33 {
  34 #define _(sym,str) IPSEC_INPUT_ERROR_##sym,
  35   foreach_ipsec_input_error
  36 #undef _
  37     IPSEC_INPUT_N_ERROR,
  38 } ipsec_input_error_t;
  39
  40 static char *ipsec_input_error_strings[] = {
  41 #define _(sym,string) string,
  42   foreach_ipsec_input_error
  43 #undef _
  44 };
  45
  46 typedef struct
  47 {
  48   ip_protocol_t proto;
  49   u32 spd;
  50   u32 policy_index;
  51   u32 sa_id;
  52   u32 spi;
  53   u32 seq;
  54 } ipsec_input_trace_t;
  55
  56 /* packet trace format function */
  57 static u8 *
  58 format_ipsec_input_trace (u8 * s, va_list * args)
  59 {
  60   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  61   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  62   ipsec_input_trace_t *t = va_arg (*args, ipsec_input_trace_t *);
  63
  64   s = format (s, "%U: sa_id %u spd %u policy %d spi %u (0x%08x) seq %u",
  65               format_ip_protocol, t->proto, t->sa_id,
  66               t->spd, t->policy_index, t->spi, t->spi, t->seq);
  67
  68   return s;
  69 }
  70
  71 always_inline ipsec_policy_t *
  72 ipsec_input_protect_policy_match (ipsec_spd_t * spd, u32 sa, u32 da, u32 spi)
  73 {
  74   ipsec_main_t *im = &ipsec_main;
  75   ipsec_policy_t *p;
  76   ipsec_sa_t *s;
  77   u32 *i;
  78
  79   vec_foreach (i, spd->policies[IPSEC_SPD_POLICY_IP4_INBOUND_PROTECT])
  80   {
  81     p = pool_elt_at_index (im->policies, *i);
  82     s = pool_elt_at_index (im->sad, p->sa_index);
  83
  84     if (spi != s->spi)
  85       continue;
  86
  87     if (ipsec_sa_is_set_IS_TUNNEL (s))
  88       {
  89         if (da != s->tunnel_dst_addr.ip4.as_u32)
  90           continue;
  91
  92         if (sa != s->tunnel_src_addr.ip4.as_u32)
  93           continue;
  94
  95         return p;
  96       }
  97
  98     if (da < p->laddr.start.ip4.as_u32)
  99       continue;
 100
 101     if (da > p->laddr.stop.ip4.as_u32)
 102       continue;
 103
 104     if (sa < p->raddr.start.ip4.as_u32)
 105       continue;
 106
 107     if (sa > p->raddr.stop.ip4.as_u32)
 108       continue;
 109
 110     return p;
 111   }
 112   return 0;
 113 }
 114
 115 always_inline uword
 116 ip6_addr_match_range (ip6_address_t * a, ip6_address_t * la,
 117                       ip6_address_t * ua)
 118 {
 119   if ((memcmp (a->as_u64, la->as_u64, 2 * sizeof (u64)) >= 0) &&
 120       (memcmp (a->as_u64, ua->as_u64, 2 * sizeof (u64)) <= 0))
 121     return 1;
 122   return 0;
 123 }
 124
 125 always_inline ipsec_policy_t *
 126 ipsec6_input_protect_policy_match (ipsec_spd_t * spd,
 127                                    ip6_address_t * sa,
 128                                    ip6_address_t * da, u32 spi)
 129 {
 130   ipsec_main_t *im = &ipsec_main;
 131   ipsec_policy_t *p;
 132   ipsec_sa_t *s;
 133   u32 *i;
 134
 135   vec_foreach (i, spd->policies[IPSEC_SPD_POLICY_IP6_INBOUND_PROTECT])
 136   {
 137     p = pool_elt_at_index (im->policies, *i);
 138     s = pool_elt_at_index (im->sad, p->sa_index);
 139
 140     if (spi != s->spi)
 141       continue;
 142
 143     if (ipsec_sa_is_set_IS_TUNNEL (s))
 144       {
 145         if (!ip6_address_is_equal (sa, &s->tunnel_src_addr.ip6))
 146           continue;
 147
 148         if (!ip6_address_is_equal (da, &s->tunnel_dst_addr.ip6))
 149           continue;
 150
 151         return p;
 152       }
 153
 154     if (!ip6_addr_match_range (sa, &p->raddr.start.ip6, &p->raddr.stop.ip6))
 155       continue;
 156
 157     if (!ip6_addr_match_range (da, &p->laddr.start.ip6, &p->laddr.stop.ip6))
 158       continue;
 159
 160     return p;
 161   }
 162   return 0;
 163 }
 164
 165 static vlib_node_registration_t ipsec4_input_node;
 166
 167 VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm,
 168                                   vlib_node_runtime_t * node,
 169                                   vlib_frame_t * from_frame)
 170 {
 171   u32 n_left_from, *from, next_index, *to_next, thread_index;
 172   ipsec_main_t *im = &ipsec_main;
 173   u32 ipsec_unprocessed = 0;
 174   u32 ipsec_matched = 0;
 175
 176   from = vlib_frame_vector_args (from_frame);
 177   n_left_from = from_frame->n_vectors;
 178   thread_index = vm->thread_index;
 179
 180   next_index = node->cached_next_index;
 181
 182   while (n_left_from > 0)
 183     {
 184       u32 n_left_to_next;
 185
 186       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 187
 188       while (n_left_from > 0 && n_left_to_next > 0)
 189         {
 190           u32 bi0, next0, pi0;
 191           vlib_buffer_t *b0;
 192           ip4_header_t *ip0;
 193           esp_header_t *esp0;
 194           ah_header_t *ah0;
 195           ip4_ipsec_config_t *c0;
 196           ipsec_spd_t *spd0;
 197           ipsec_policy_t *p0 = 0;
 198
 199           bi0 = to_next[0] = from[0];
 200           from += 1;
 201           n_left_from -= 1;
 202           to_next += 1;
 203           n_left_to_next -= 1;
 204
 205           b0 = vlib_get_buffer (vm, bi0);
 206           b0->flags |= VNET_BUFFER_F_IS_IP4;
 207           b0->flags &= ~VNET_BUFFER_F_IS_IP6;
 208           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 209
 210           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 211
 212           ip0 = vlib_buffer_get_current (b0);
 213
 214           if (PREDICT_TRUE
 215               (ip0->protocol == IP_PROTOCOL_IPSEC_ESP
 216                || ip0->protocol == IP_PROTOCOL_UDP))
 217             {
 218 #if 0
 219               clib_warning
 220                 ("packet received from %U to %U spi %u size %u spd_id %u",
 221                  format_ip4_address, ip0->src_address.as_u8,
 222                  format_ip4_address, ip0->dst_address.as_u8,
 223                  clib_net_to_host_u32 (esp0->spi),
 224                  clib_net_to_host_u16 (ip0->length), spd0->id);
 225 #endif
 226
 227               esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 228               if (PREDICT_FALSE (ip0->protocol == IP_PROTOCOL_UDP))
 229                 {
 230                   esp0 =
 231                     (esp_header_t *) ((u8 *) esp0 + sizeof (udp_header_t));
 232                 }
 233               /* FIXME TODO missing check whether there is enough data inside
 234                * IP/UDP to contain ESP header & stuff ? */
 235               p0 = ipsec_input_protect_policy_match (spd0,
 236                                                      ip0->src_address.as_u32,
 237                                                      ip0->dst_address.as_u32,
 238                                                      clib_net_to_host_u32
 239                                                      (esp0->spi));
 240
 241               if (PREDICT_TRUE (p0 != NULL))
 242                 {
 243                   ipsec_matched += 1;
 244
 245                   pi0 = p0 - im->policies;
 246                   vlib_increment_combined_counter
 247                     (&ipsec_spd_policy_counters,
 248                      thread_index, pi0, 1,
 249                      clib_net_to_host_u16 (ip0->length));
 250
 251                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 252                   next0 = im->esp4_decrypt_next_index;
 253                   vlib_buffer_advance (b0, ((u8 *) esp0 - (u8 *) ip0));
 254                   goto trace0;
 255                 }
 256               else
 257                 {
 258                   pi0 = ~0;
 259                 };
 260
 261               /* FIXME bypass and discard */
 262             trace0:
 263               if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 264                   PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 265                 {
 266                   ipsec_input_trace_t *tr =
 267                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 268
 269                   tr->proto = ip0->protocol;
 270                   if (p0)
 271                     tr->sa_id = p0->sa_id;
 272                   tr->spi = clib_net_to_host_u32 (esp0->spi);
 273                   tr->seq = clib_net_to_host_u32 (esp0->seq);
 274                   tr->spd = spd0->id;
 275                   tr->policy_index = pi0;
 276                 }
 277             }
 278           else if (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                                                      ip0->src_address.as_u32,
 283                                                      ip0->dst_address.as_u32,
 284                                                      clib_net_to_host_u32
 285                                                      (ah0->spi));
 286
 287               if (PREDICT_TRUE (p0 != 0))
 288                 {
 289                   ipsec_matched += 1;
 290
 291                   pi0 = p0 - im->policies;
 292                   vlib_increment_combined_counter
 293                     (&ipsec_spd_policy_counters,
 294                      thread_index, pi0, 1,
 295                      clib_net_to_host_u16 (ip0->length));
 296
 297                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 298                   next0 = im->ah4_decrypt_next_index;
 299                   goto trace1;
 300                 }
 301               else
 302                 {
 303                   pi0 = ~0;
 304                 }
 305               /* FIXME bypass and discard */
 306             trace1:
 307               if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 308                   PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 309                 {
 310                   ipsec_input_trace_t *tr =
 311                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 312
 313                   tr->proto = ip0->protocol;
 314                   if (p0)
 315                     tr->sa_id = p0->sa_id;
 316                   tr->spi = clib_net_to_host_u32 (ah0->spi);
 317                   tr->seq = clib_net_to_host_u32 (ah0->seq_no);
 318                   tr->spd = spd0->id;
 319                   tr->policy_index = pi0;
 320                 }
 321             }
 322           else
 323             {
 324               ipsec_unprocessed += 1;
 325             }
 326
 327           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 328                                            to_next, n_left_to_next, bi0,
 329                                            next0);
 330         }
 331       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 332     }
 333
 334   vlib_node_increment_counter (vm, ipsec4_input_node.index,
 335                                IPSEC_INPUT_ERROR_RX_PKTS,
 336                                from_frame->n_vectors - ipsec_unprocessed);
 337
 338   vlib_node_increment_counter (vm, ipsec4_input_node.index,
 339                                IPSEC_INPUT_ERROR_RX_MATCH_PKTS,
 340                                ipsec_matched);
 341   return from_frame->n_vectors;
 342 }
 343
 344
 345 /* *INDENT-OFF* */
 346 VLIB_REGISTER_NODE (ipsec4_input_node,static) = {
 347   .name = "ipsec4-input-feature",
 348   .vector_size = sizeof (u32),
 349   .format_trace = format_ipsec_input_trace,
 350   .type = VLIB_NODE_TYPE_INTERNAL,
 351   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 352   .error_strings = ipsec_input_error_strings,
 353   .n_next_nodes = IPSEC_INPUT_N_NEXT,
 354   .next_nodes = {
 355 #define _(s,n) [IPSEC_INPUT_NEXT_##s] = n,
 356     foreach_ipsec_input_next
 357 #undef _
 358   },
 359 };
 360 /* *INDENT-ON* */
 361
 362 static vlib_node_registration_t ipsec6_input_node;
 363
 364
 365 VLIB_NODE_FN (ipsec6_input_node) (vlib_main_t * vm,
 366                                   vlib_node_runtime_t * node,
 367                                   vlib_frame_t * from_frame)
 368 {
 369   u32 n_left_from, *from, next_index, *to_next, thread_index;
 370   ipsec_main_t *im = &ipsec_main;
 371   u32 ipsec_unprocessed = 0;
 372   u32 ipsec_matched = 0;
 373
 374   from = vlib_frame_vector_args (from_frame);
 375   n_left_from = from_frame->n_vectors;
 376   thread_index = vm->thread_index;
 377
 378   next_index = node->cached_next_index;
 379
 380   while (n_left_from > 0)
 381     {
 382       u32 n_left_to_next;
 383
 384       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 385
 386       while (n_left_from > 0 && n_left_to_next > 0)
 387         {
 388           u32 bi0, next0, pi0;
 389           vlib_buffer_t *b0;
 390           ip6_header_t *ip0;
 391           esp_header_t *esp0;
 392           ip4_ipsec_config_t *c0;
 393           ipsec_spd_t *spd0;
 394           ipsec_policy_t *p0 = 0;
 395           ah_header_t *ah0;
 396           u32 header_size = sizeof (ip0[0]);
 397
 398           bi0 = to_next[0] = from[0];
 399           from += 1;
 400           n_left_from -= 1;
 401           to_next += 1;
 402           n_left_to_next -= 1;
 403
 404           b0 = vlib_get_buffer (vm, bi0);
 405           b0->flags |= VNET_BUFFER_F_IS_IP6;
 406           b0->flags &= ~VNET_BUFFER_F_IS_IP4;
 407           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 408
 409           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 410
 411           ip0 = vlib_buffer_get_current (b0);
 412           esp0 = (esp_header_t *) ((u8 *) ip0 + header_size);
 413           ah0 = (ah_header_t *) ((u8 *) ip0 + header_size);
 414
 415           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
 416             {
 417 #if 0
 418               clib_warning
 419                 ("packet received from %U to %U spi %u size %u spd_id %u",
 420                  format_ip6_address, &ip0->src_address, format_ip6_address,
 421                  &ip0->dst_address, clib_net_to_host_u32 (esp0->spi),
 422                  clib_net_to_host_u16 (ip0->payload_length) + header_size,
 423                  spd0->id);
 424 #endif
 425               p0 = ipsec6_input_protect_policy_match (spd0,
 426                                                       &ip0->src_address,
 427                                                       &ip0->dst_address,
 428                                                       clib_net_to_host_u32
 429                                                       (esp0->spi));
 430
 431               if (PREDICT_TRUE (p0 != 0))
 432                 {
 433                   ipsec_matched += 1;
 434
 435                   pi0 = p0 - im->policies;
 436                   vlib_increment_combined_counter
 437                     (&ipsec_spd_policy_counters,
 438                      thread_index, pi0, 1,
 439                      clib_net_to_host_u16 (ip0->payload_length) +
 440                      header_size);
 441
 442                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 443                   next0 = im->esp6_decrypt_next_index;
 444                   vlib_buffer_advance (b0, header_size);
 445                   goto trace0;
 446                 }
 447               else
 448                 {
 449                   pi0 = ~0;
 450                 }
 451             }
 452           else if (ip0->protocol == IP_PROTOCOL_IPSEC_AH)
 453             {
 454               p0 = ipsec6_input_protect_policy_match (spd0,
 455                                                       &ip0->src_address,
 456                                                       &ip0->dst_address,
 457                                                       clib_net_to_host_u32
 458                                                       (ah0->spi));
 459
 460               if (PREDICT_TRUE (p0 != 0))
 461                 {
 462                   ipsec_matched += 1;
 463                   pi0 = p0 - im->policies;
 464                   vlib_increment_combined_counter
 465                     (&ipsec_spd_policy_counters,
 466                      thread_index, pi0, 1,
 467                      clib_net_to_host_u16 (ip0->payload_length) +
 468                      header_size);
 469
 470                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 471                   next0 = im->ah6_decrypt_next_index;
 472                   goto trace0;
 473                 }
 474               else
 475                 {
 476                   pi0 = ~0;
 477                 }
 478             }
 479           else
 480             {
 481               ipsec_unprocessed += 1;
 482             }
 483
 484         trace0:
 485           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 486               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 487             {
 488               ipsec_input_trace_t *tr =
 489                 vlib_add_trace (vm, node, b0, sizeof (*tr));
 490
 491               if (p0)
 492                 tr->sa_id = p0->sa_id;
 493               tr->proto = ip0->protocol;
 494               tr->spi = clib_net_to_host_u32 (esp0->spi);
 495               tr->seq = clib_net_to_host_u32 (esp0->seq);
 496               tr->spd = spd0->id;
 497             }
 498
 499           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 500                                            n_left_to_next, bi0, next0);
 501         }
 502       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 503     }
 504
 505   vlib_node_increment_counter (vm, ipsec6_input_node.index,
 506                                IPSEC_INPUT_ERROR_RX_PKTS,
 507                                from_frame->n_vectors - ipsec_unprocessed);
 508
 509   vlib_node_increment_counter (vm, ipsec6_input_node.index,
 510                                IPSEC_INPUT_ERROR_RX_MATCH_PKTS,
 511                                ipsec_matched);
 512
 513   return from_frame->n_vectors;
 514 }
 515
 516
 517 /* *INDENT-OFF* */
 518 VLIB_REGISTER_NODE (ipsec6_input_node,static) = {
 519   .name = "ipsec6-input-feature",
 520   .vector_size = sizeof (u32),
 521   .format_trace = format_ipsec_input_trace,
 522   .type = VLIB_NODE_TYPE_INTERNAL,
 523   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 524   .error_strings = ipsec_input_error_strings,
 525   .n_next_nodes = IPSEC_INPUT_N_NEXT,
 526   .next_nodes = {
 527 #define _(s,n) [IPSEC_INPUT_NEXT_##s] = n,
 528     foreach_ipsec_input_next
 529 #undef _
 530   },
 531 };
 532 /* *INDENT-ON* */
 533
 534 /*
 535  * fd.io coding-style-patch-verification: ON
 536  *
 537  * Local Variables:
 538  * eval: (c-set-style "gnu")
 539  * End:
 540  */