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 _(RX_MATCH_PKTS, "IPSEC pkts matched")
  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   ip_protocol_t proto;
  48   u32 spd;
  49   u32 policy_index;
  50   u32 sa_id;
  51   u32 spi;
  52   u32 seq;
  53 } ipsec_input_trace_t;
  54
  55 /* packet trace format function */
  56 static u8 *
  57 format_ipsec_input_trace (u8 * s, va_list * args)
  58 {
  59   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  60   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  61   ipsec_input_trace_t *t = va_arg (*args, ipsec_input_trace_t *);
  62
  63   s = format (s, "%U: sa_id %u spd %u policy %d spi %u seq %u",
  64               format_ip_protocol, t->proto, t->sa_id,
  65               t->spd, t->policy_index, t->spi, t->seq);
  66
  67   return s;
  68 }
  69
  70 always_inline ipsec_policy_t *
  71 ipsec_input_protect_policy_match (ipsec_spd_t * spd, u32 sa, u32 da, u32 spi)
  72 {
  73   ipsec_main_t *im = &ipsec_main;
  74   ipsec_policy_t *p;
  75   ipsec_sa_t *s;
  76   u32 *i;
  77
  78   vec_foreach (i, spd->policies[IPSEC_SPD_POLICY_IP4_INBOUND_PROTECT])
  79   {
  80     p = pool_elt_at_index (im->policies, *i);
  81     s = pool_elt_at_index (im->sad, p->sa_index);
  82
  83     if (spi != s->spi)
  84       continue;
  85
  86     if (s->is_tunnel)
  87       {
  88         if (da != clib_net_to_host_u32 (s->tunnel_dst_addr.ip4.as_u32))
  89           continue;
  90
  91         if (sa != clib_net_to_host_u32 (s->tunnel_src_addr.ip4.as_u32))
  92           continue;
  93
  94         return p;
  95       }
  96
  97     if (da < clib_net_to_host_u32 (p->laddr.start.ip4.as_u32))
  98       continue;
  99
 100     if (da > clib_net_to_host_u32 (p->laddr.stop.ip4.as_u32))
 101       continue;
 102
 103     if (sa < clib_net_to_host_u32 (p->raddr.start.ip4.as_u32))
 104       continue;
 105
 106     if (sa > clib_net_to_host_u32 (p->raddr.stop.ip4.as_u32))
 107       continue;
 108
 109     return p;
 110   }
 111   return 0;
 112 }
 113
 114 always_inline uword
 115 ip6_addr_match_range (ip6_address_t * a, ip6_address_t * la,
 116                       ip6_address_t * ua)
 117 {
 118   if ((memcmp (a->as_u64, la->as_u64, 2 * sizeof (u64)) >= 0) &&
 119       (memcmp (a->as_u64, ua->as_u64, 2 * sizeof (u64)) <= 0))
 120     return 1;
 121   return 0;
 122 }
 123
 124 always_inline ipsec_policy_t *
 125 ipsec6_input_protect_policy_match (ipsec_spd_t * spd,
 126                                    ip6_address_t * sa,
 127                                    ip6_address_t * da, u32 spi)
 128 {
 129   ipsec_main_t *im = &ipsec_main;
 130   ipsec_policy_t *p;
 131   ipsec_sa_t *s;
 132   u32 *i;
 133
 134   vec_foreach (i, spd->policies[IPSEC_SPD_POLICY_IP6_INBOUND_PROTECT])
 135   {
 136     p = pool_elt_at_index (im->policies, *i);
 137     s = pool_elt_at_index (im->sad, p->sa_index);
 138
 139     if (spi != s->spi)
 140       continue;
 141
 142     if (s->is_tunnel)
 143       {
 144         if (!ip6_address_is_equal (sa, &s->tunnel_src_addr.ip6))
 145           continue;
 146
 147         if (!ip6_address_is_equal (da, &s->tunnel_dst_addr.ip6))
 148           continue;
 149
 150         return p;
 151       }
 152
 153     if (!ip6_addr_match_range (sa, &p->raddr.start.ip6, &p->raddr.stop.ip6))
 154       continue;
 155
 156     if (!ip6_addr_match_range (da, &p->laddr.start.ip6, &p->laddr.stop.ip6))
 157       continue;
 158
 159     return p;
 160   }
 161   return 0;
 162 }
 163
 164 static vlib_node_registration_t ipsec4_input_node;
 165
 166 VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm,
 167                                   vlib_node_runtime_t * node,
 168                                   vlib_frame_t * from_frame)
 169 {
 170   u32 n_left_from, *from, next_index, *to_next, thread_index;
 171   ipsec_main_t *im = &ipsec_main;
 172   u32 ipsec_unprocessed = 0;
 173   u32 ipsec_matched = 0;
 174
 175   from = vlib_frame_vector_args (from_frame);
 176   n_left_from = from_frame->n_vectors;
 177   thread_index = vm->thread_index;
 178
 179   next_index = node->cached_next_index;
 180
 181   while (n_left_from > 0)
 182     {
 183       u32 n_left_to_next;
 184
 185       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 186
 187       while (n_left_from > 0 && n_left_to_next > 0)
 188         {
 189           u32 bi0, next0, pi0;
 190           vlib_buffer_t *b0;
 191           ip4_header_t *ip0;
 192           esp_header_t *esp0;
 193           ah_header_t *ah0;
 194           ip4_ipsec_config_t *c0;
 195           ipsec_spd_t *spd0;
 196           ipsec_policy_t *p0 = 0;
 197
 198           bi0 = to_next[0] = from[0];
 199           from += 1;
 200           n_left_from -= 1;
 201           to_next += 1;
 202           n_left_to_next -= 1;
 203
 204           b0 = vlib_get_buffer (vm, bi0);
 205           b0->flags |= VNET_BUFFER_F_IS_IP4;
 206           b0->flags &= ~VNET_BUFFER_F_IS_IP6;
 207           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 208
 209           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 210
 211           ip0 = vlib_buffer_get_current (b0);
 212
 213           if (PREDICT_TRUE
 214               (ip0->protocol == IP_PROTOCOL_IPSEC_ESP
 215                || ip0->protocol == IP_PROTOCOL_UDP))
 216             {
 217 #if 0
 218               clib_warning
 219                 ("packet received from %U to %U spi %u size %u spd_id %u",
 220                  format_ip4_address, ip0->src_address.as_u8,
 221                  format_ip4_address, ip0->dst_address.as_u8,
 222                  clib_net_to_host_u32 (esp0->spi),
 223                  clib_net_to_host_u16 (ip0->length), spd0->id);
 224 #endif
 225
 226               esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 227               if (PREDICT_FALSE (ip0->protocol == IP_PROTOCOL_UDP))
 228                 {
 229                   esp0 =
 230                     (esp_header_t *) ((u8 *) esp0 + sizeof (udp_header_t));
 231                 }
 232               /* FIXME TODO missing check whether there is enough data inside
 233                * IP/UDP to contain ESP header & stuff ? */
 234               p0 = ipsec_input_protect_policy_match (spd0,
 235                                                      clib_net_to_host_u32
 236                                                      (ip0->src_address.
 237                                                       as_u32),
 238                                                      clib_net_to_host_u32
 239                                                      (ip0->dst_address.
 240                                                       as_u32),
 241                                                      clib_net_to_host_u32
 242                                                      (esp0->spi));
 243
 244               if (PREDICT_TRUE (p0 != NULL))
 245                 {
 246                   ipsec_matched += 1;
 247
 248                   pi0 = p0 - im->policies;
 249                   vlib_increment_combined_counter
 250                     (&ipsec_spd_policy_counters,
 251                      thread_index, pi0, 1,
 252                      clib_net_to_host_u16 (ip0->length));
 253
 254                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 255                   vnet_buffer (b0)->ipsec.flags = 0;
 256                   next0 = im->esp4_decrypt_next_index;
 257                   vlib_buffer_advance (b0, ((u8 *) esp0 - (u8 *) ip0));
 258                   goto trace0;
 259                 }
 260               else
 261                 {
 262                   pi0 = ~0;
 263                 };
 264
 265               /* FIXME bypass and discard */
 266             trace0:
 267               if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 268                   PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 269                 {
 270                   ipsec_input_trace_t *tr =
 271                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 272
 273                   tr->proto = ip0->protocol;
 274                   if (p0)
 275                     tr->sa_id = p0->sa_id;
 276                   tr->spi = clib_net_to_host_u32 (esp0->spi);
 277                   tr->seq = clib_net_to_host_u32 (esp0->seq);
 278                   tr->spd = spd0->id;
 279                   tr->policy_index = pi0;
 280                 }
 281             }
 282           else if (ip0->protocol == IP_PROTOCOL_IPSEC_AH)
 283             {
 284               ah0 = (ah_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 285               p0 = ipsec_input_protect_policy_match (spd0,
 286                                                      clib_net_to_host_u32
 287                                                      (ip0->src_address.
 288                                                       as_u32),
 289                                                      clib_net_to_host_u32
 290                                                      (ip0->dst_address.
 291                                                       as_u32),
 292                                                      clib_net_to_host_u32
 293                                                      (ah0->spi));
 294
 295               if (PREDICT_TRUE (p0 != 0))
 296                 {
 297                   ipsec_matched += 1;
 298
 299                   pi0 = p0 - im->policies;
 300                   vlib_increment_combined_counter
 301                     (&ipsec_spd_policy_counters,
 302                      thread_index, pi0, 1,
 303                      clib_net_to_host_u16 (ip0->length));
 304
 305                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 306                   vnet_buffer (b0)->ipsec.flags = 0;
 307                   next0 = im->ah4_decrypt_next_index;
 308                   goto trace1;
 309                 }
 310               else
 311                 {
 312                   pi0 = ~0;
 313                 }
 314               /* FIXME bypass and discard */
 315             trace1:
 316               if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 317                   PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 318                 {
 319                   ipsec_input_trace_t *tr =
 320                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 321
 322                   tr->proto = ip0->protocol;
 323                   if (p0)
 324                     tr->sa_id = p0->sa_id;
 325                   tr->spi = clib_net_to_host_u32 (ah0->spi);
 326                   tr->seq = clib_net_to_host_u32 (ah0->seq_no);
 327                   tr->spd = spd0->id;
 328                   tr->policy_index = pi0;
 329                 }
 330             }
 331           else
 332             {
 333               ipsec_unprocessed += 1;
 334             }
 335
 336           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 337                                            to_next, n_left_to_next, bi0,
 338                                            next0);
 339         }
 340       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 341     }
 342
 343   vlib_node_increment_counter (vm, ipsec4_input_node.index,
 344                                IPSEC_INPUT_ERROR_RX_PKTS,
 345                                from_frame->n_vectors - ipsec_unprocessed);
 346
 347   vlib_node_increment_counter (vm, ipsec4_input_node.index,
 348                                IPSEC_INPUT_ERROR_RX_MATCH_PKTS,
 349                                ipsec_matched);
 350   return from_frame->n_vectors;
 351 }
 352
 353
 354 /* *INDENT-OFF* */
 355 VLIB_REGISTER_NODE (ipsec4_input_node,static) = {
 356   .name = "ipsec4-input-feature",
 357   .vector_size = sizeof (u32),
 358   .format_trace = format_ipsec_input_trace,
 359   .type = VLIB_NODE_TYPE_INTERNAL,
 360   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 361   .error_strings = ipsec_input_error_strings,
 362   .n_next_nodes = IPSEC_INPUT_N_NEXT,
 363   .next_nodes = {
 364 #define _(s,n) [IPSEC_INPUT_NEXT_##s] = n,
 365     foreach_ipsec_input_next
 366 #undef _
 367   },
 368 };
 369 /* *INDENT-ON* */
 370
 371 static vlib_node_registration_t ipsec6_input_node;
 372
 373
 374 VLIB_NODE_FN (ipsec6_input_node) (vlib_main_t * vm,
 375                                   vlib_node_runtime_t * node,
 376                                   vlib_frame_t * from_frame)
 377 {
 378   u32 n_left_from, *from, next_index, *to_next, thread_index;
 379   ipsec_main_t *im = &ipsec_main;
 380   u32 ipsec_unprocessed = 0;
 381   u32 ipsec_matched = 0;
 382
 383   from = vlib_frame_vector_args (from_frame);
 384   n_left_from = from_frame->n_vectors;
 385   thread_index = vm->thread_index;
 386
 387   next_index = node->cached_next_index;
 388
 389   while (n_left_from > 0)
 390     {
 391       u32 n_left_to_next;
 392
 393       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 394
 395       while (n_left_from > 0 && n_left_to_next > 0)
 396         {
 397           u32 bi0, next0, pi0;
 398           vlib_buffer_t *b0;
 399           ip6_header_t *ip0;
 400           esp_header_t *esp0;
 401           ip4_ipsec_config_t *c0;
 402           ipsec_spd_t *spd0;
 403           ipsec_policy_t *p0 = 0;
 404           ah_header_t *ah0;
 405           u32 header_size = sizeof (ip0[0]);
 406
 407           bi0 = to_next[0] = from[0];
 408           from += 1;
 409           n_left_from -= 1;
 410           to_next += 1;
 411           n_left_to_next -= 1;
 412
 413           b0 = vlib_get_buffer (vm, bi0);
 414           b0->flags |= VNET_BUFFER_F_IS_IP6;
 415           b0->flags &= ~VNET_BUFFER_F_IS_IP4;
 416           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 417
 418           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 419
 420           ip0 = vlib_buffer_get_current (b0);
 421           esp0 = (esp_header_t *) ((u8 *) ip0 + header_size);
 422           ah0 = (ah_header_t *) ((u8 *) ip0 + header_size);
 423
 424           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
 425             {
 426 #if 0
 427               clib_warning
 428                 ("packet received from %U to %U spi %u size %u spd_id %u",
 429                  format_ip6_address, &ip0->src_address, format_ip6_address,
 430                  &ip0->dst_address, clib_net_to_host_u32 (esp0->spi),
 431                  clib_net_to_host_u16 (ip0->payload_length) + header_size,
 432                  spd0->id);
 433 #endif
 434               p0 = ipsec6_input_protect_policy_match (spd0,
 435                                                       &ip0->src_address,
 436                                                       &ip0->dst_address,
 437                                                       clib_net_to_host_u32
 438                                                       (esp0->spi));
 439
 440               if (PREDICT_TRUE (p0 != 0))
 441                 {
 442                   ipsec_matched += 1;
 443
 444                   pi0 = p0 - im->policies;
 445                   vlib_increment_combined_counter
 446                     (&ipsec_spd_policy_counters,
 447                      thread_index, pi0, 1,
 448                      clib_net_to_host_u16 (ip0->payload_length) +
 449                      header_size);
 450
 451                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 452                   vnet_buffer (b0)->ipsec.flags = 0;
 453                   next0 = im->esp6_decrypt_next_index;
 454                   vlib_buffer_advance (b0, header_size);
 455                   goto trace0;
 456                 }
 457               else
 458                 {
 459                   pi0 = ~0;
 460                 }
 461             }
 462           else if (ip0->protocol == IP_PROTOCOL_IPSEC_AH)
 463             {
 464               p0 = ipsec6_input_protect_policy_match (spd0,
 465                                                       &ip0->src_address,
 466                                                       &ip0->dst_address,
 467                                                       clib_net_to_host_u32
 468                                                       (ah0->spi));
 469
 470               if (PREDICT_TRUE (p0 != 0))
 471                 {
 472                   ipsec_matched += 1;
 473                   pi0 = p0 - im->policies;
 474                   vlib_increment_combined_counter
 475                     (&ipsec_spd_policy_counters,
 476                      thread_index, pi0, 1,
 477                      clib_net_to_host_u16 (ip0->payload_length) +
 478                      header_size);
 479
 480                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 481                   vnet_buffer (b0)->ipsec.flags = 0;
 482                   next0 = im->ah6_decrypt_next_index;
 483                   goto trace0;
 484                 }
 485               else
 486                 {
 487                   pi0 = ~0;
 488                 }
 489             }
 490           else
 491             {
 492               ipsec_unprocessed += 1;
 493             }
 494
 495         trace0:
 496           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 497               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 498             {
 499               ipsec_input_trace_t *tr =
 500                 vlib_add_trace (vm, node, b0, sizeof (*tr));
 501
 502               if (p0)
 503                 tr->sa_id = p0->sa_id;
 504               tr->proto = ip0->protocol;
 505               tr->spi = clib_net_to_host_u32 (esp0->spi);
 506               tr->seq = clib_net_to_host_u32 (esp0->seq);
 507               tr->spd = spd0->id;
 508             }
 509
 510           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 511                                            n_left_to_next, bi0, next0);
 512         }
 513       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 514     }
 515
 516   vlib_node_increment_counter (vm, ipsec6_input_node.index,
 517                                IPSEC_INPUT_ERROR_RX_PKTS,
 518                                from_frame->n_vectors - ipsec_unprocessed);
 519
 520   vlib_node_increment_counter (vm, ipsec6_input_node.index,
 521                                IPSEC_INPUT_ERROR_RX_MATCH_PKTS,
 522                                ipsec_matched);
 523
 524   return from_frame->n_vectors;
 525 }
 526
 527
 528 /* *INDENT-OFF* */
 529 VLIB_REGISTER_NODE (ipsec6_input_node,static) = {
 530   .name = "ipsec6-input-feature",
 531   .vector_size = sizeof (u32),
 532   .format_trace = format_ipsec_input_trace,
 533   .type = VLIB_NODE_TYPE_INTERNAL,
 534   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 535   .error_strings = ipsec_input_error_strings,
 536   .n_next_nodes = IPSEC_INPUT_N_NEXT,
 537   .next_nodes = {
 538 #define _(s,n) [IPSEC_INPUT_NEXT_##s] = n,
 539     foreach_ipsec_input_next
 540 #undef _
 541   },
 542 };
 543 /* *INDENT-ON* */
 544
 545 /*
 546  * fd.io coding-style-patch-verification: ON
 547  *
 548  * Local Variables:
 549  * eval: (c-set-style "gnu")
 550  * End:
 551  */