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   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
 173   from = vlib_frame_vector_args (from_frame);
 174   n_left_from = from_frame->n_vectors;
 175   thread_index = vm->thread_index;
 176
 177   next_index = node->cached_next_index;
 178
 179   while (n_left_from > 0)
 180     {
 181       u32 n_left_to_next;
 182
 183       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 184
 185       while (n_left_from > 0 && n_left_to_next > 0)
 186         {
 187           u32 bi0, next0, pi0;
 188           vlib_buffer_t *b0;
 189           ip4_header_t *ip0;
 190           esp_header_t *esp0;
 191           ah_header_t *ah0;
 192           ip4_ipsec_config_t *c0;
 193           ipsec_spd_t *spd0;
 194           ipsec_policy_t *p0 = 0;
 195
 196           bi0 = to_next[0] = from[0];
 197           from += 1;
 198           n_left_from -= 1;
 199           to_next += 1;
 200           n_left_to_next -= 1;
 201
 202           b0 = vlib_get_buffer (vm, bi0);
 203           b0->flags |= VNET_BUFFER_F_IS_IP4;
 204           b0->flags &= ~VNET_BUFFER_F_IS_IP6;
 205           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 206
 207           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 208
 209           ip0 = vlib_buffer_get_current (b0);
 210
 211           if (PREDICT_TRUE
 212               (ip0->protocol == IP_PROTOCOL_IPSEC_ESP
 213                || ip0->protocol == IP_PROTOCOL_UDP))
 214             {
 215 #if 0
 216               clib_warning
 217                 ("packet received from %U to %U spi %u size %u spd_id %u",
 218                  format_ip4_address, ip0->src_address.as_u8,
 219                  format_ip4_address, ip0->dst_address.as_u8,
 220                  clib_net_to_host_u32 (esp0->spi),
 221                  clib_net_to_host_u16 (ip0->length), spd0->id);
 222 #endif
 223
 224               esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 225               if (PREDICT_FALSE (ip0->protocol == IP_PROTOCOL_UDP))
 226                 {
 227                   esp0 =
 228                     (esp_header_t *) ((u8 *) esp0 + sizeof (udp_header_t));
 229                 }
 230               /* FIXME TODO missing check whether there is enough data inside
 231                * IP/UDP to contain ESP header & stuff ? */
 232               p0 = ipsec_input_protect_policy_match (spd0,
 233                                                      clib_net_to_host_u32
 234                                                      (ip0->src_address.
 235                                                       as_u32),
 236                                                      clib_net_to_host_u32
 237                                                      (ip0->dst_address.
 238                                                       as_u32),
 239                                                      clib_net_to_host_u32
 240                                                      (esp0->spi));
 241
 242               if (PREDICT_TRUE (p0 != NULL))
 243                 {
 244                   pi0 = p0 - im->policies;
 245                   vlib_increment_combined_counter
 246                     (&ipsec_spd_policy_counters,
 247                      thread_index, pi0, 1,
 248                      clib_net_to_host_u16 (ip0->length));
 249
 250                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 251                   vnet_buffer (b0)->ipsec.flags = 0;
 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
 279           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_AH))
 280             {
 281               ah0 = (ah_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 282               p0 = ipsec_input_protect_policy_match (spd0,
 283                                                      clib_net_to_host_u32
 284                                                      (ip0->src_address.
 285                                                       as_u32),
 286                                                      clib_net_to_host_u32
 287                                                      (ip0->dst_address.
 288                                                       as_u32),
 289                                                      clib_net_to_host_u32
 290                                                      (ah0->spi));
 291
 292               if (PREDICT_TRUE (p0 != 0))
 293                 {
 294                   pi0 = p0 - im->policies;
 295                   vlib_increment_combined_counter
 296                     (&ipsec_spd_policy_counters,
 297                      thread_index, pi0, 1,
 298                      clib_net_to_host_u16 (ip0->length));
 299                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 300                   vnet_buffer (b0)->ipsec.flags = 0;
 301                   next0 = im->ah4_decrypt_next_index;
 302                   goto trace1;
 303                 }
 304               else
 305                 {
 306                   pi0 = ~0;
 307                 }
 308               /* FIXME bypass and discard */
 309             trace1:
 310               if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 311                   PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 312                 {
 313                   ipsec_input_trace_t *tr =
 314                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 315
 316                   tr->proto = ip0->protocol;
 317                   if (p0)
 318                     tr->sa_id = p0->sa_id;
 319                   tr->spi = clib_net_to_host_u32 (ah0->spi);
 320                   tr->seq = clib_net_to_host_u32 (ah0->seq_no);
 321                   tr->spd = spd0->id;
 322                   tr->policy_index = pi0;
 323                 }
 324             }
 325
 326           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 327                                            to_next, n_left_to_next, bi0,
 328                                            next0);
 329         }
 330       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 331     }
 332   vlib_node_increment_counter (vm, ipsec4_input_node.index,
 333                                IPSEC_INPUT_ERROR_RX_PKTS,
 334                                from_frame->n_vectors);
 335
 336   return from_frame->n_vectors;
 337 }
 338
 339
 340 /* *INDENT-OFF* */
 341 VLIB_REGISTER_NODE (ipsec4_input_node,static) = {
 342   .name = "ipsec4-input-feature",
 343   .vector_size = sizeof (u32),
 344   .format_trace = format_ipsec_input_trace,
 345   .type = VLIB_NODE_TYPE_INTERNAL,
 346
 347   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 348   .error_strings = ipsec_input_error_strings,
 349
 350   .n_next_nodes = IPSEC_INPUT_N_NEXT,
 351   .next_nodes = {
 352 #define _(s,n) [IPSEC_INPUT_NEXT_##s] = n,
 353     foreach_ipsec_input_next
 354 #undef _
 355   },
 356 };
 357 /* *INDENT-ON* */
 358
 359 static vlib_node_registration_t ipsec6_input_node;
 360
 361
 362 VLIB_NODE_FN (ipsec6_input_node) (vlib_main_t * vm,
 363                                   vlib_node_runtime_t * node,
 364                                   vlib_frame_t * from_frame)
 365 {
 366   u32 n_left_from, *from, next_index, *to_next, thread_index;
 367   ipsec_main_t *im = &ipsec_main;
 368
 369   from = vlib_frame_vector_args (from_frame);
 370   n_left_from = from_frame->n_vectors;
 371   thread_index = vm->thread_index;
 372
 373   next_index = node->cached_next_index;
 374
 375   while (n_left_from > 0)
 376     {
 377       u32 n_left_to_next;
 378
 379       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 380
 381       while (n_left_from > 0 && n_left_to_next > 0)
 382         {
 383           u32 bi0, next0, pi0;
 384           vlib_buffer_t *b0;
 385           ip6_header_t *ip0;
 386           esp_header_t *esp0;
 387           ip4_ipsec_config_t *c0;
 388           ipsec_spd_t *spd0;
 389           ipsec_policy_t *p0 = 0;
 390           ah_header_t *ah0;
 391           u32 header_size = sizeof (ip0[0]);
 392
 393           bi0 = to_next[0] = from[0];
 394           from += 1;
 395           n_left_from -= 1;
 396           to_next += 1;
 397           n_left_to_next -= 1;
 398
 399           b0 = vlib_get_buffer (vm, bi0);
 400           b0->flags |= VNET_BUFFER_F_IS_IP6;
 401           b0->flags &= ~VNET_BUFFER_F_IS_IP4;
 402           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 403
 404           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 405
 406           ip0 = vlib_buffer_get_current (b0);
 407           esp0 = (esp_header_t *) ((u8 *) ip0 + header_size);
 408           ah0 = (ah_header_t *) ((u8 *) ip0 + header_size);
 409
 410           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
 411             {
 412 #if 0
 413               clib_warning
 414                 ("packet received from %U to %U spi %u size %u spd_id %u",
 415                  format_ip6_address, &ip0->src_address, format_ip6_address,
 416                  &ip0->dst_address, clib_net_to_host_u32 (esp0->spi),
 417                  clib_net_to_host_u16 (ip0->payload_length) + header_size,
 418                  spd0->id);
 419 #endif
 420               p0 = ipsec6_input_protect_policy_match (spd0,
 421                                                       &ip0->src_address,
 422                                                       &ip0->dst_address,
 423                                                       clib_net_to_host_u32
 424                                                       (esp0->spi));
 425
 426               if (PREDICT_TRUE (p0 != 0))
 427                 {
 428                   pi0 = p0 - im->policies;
 429                   vlib_increment_combined_counter
 430                     (&ipsec_spd_policy_counters,
 431                      thread_index, pi0, 1,
 432                      clib_net_to_host_u16 (ip0->payload_length) +
 433                      header_size);
 434                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 435                   vnet_buffer (b0)->ipsec.flags = 0;
 436                   next0 = im->esp6_decrypt_next_index;
 437                   vlib_buffer_advance (b0, header_size);
 438                   goto trace0;
 439                 }
 440               else
 441                 {
 442                   pi0 = ~0;
 443                 }
 444             }
 445           else if (ip0->protocol == IP_PROTOCOL_IPSEC_AH)
 446             {
 447               p0 = ipsec6_input_protect_policy_match (spd0,
 448                                                       &ip0->src_address,
 449                                                       &ip0->dst_address,
 450                                                       clib_net_to_host_u32
 451                                                       (ah0->spi));
 452
 453               if (PREDICT_TRUE (p0 != 0))
 454                 {
 455                   pi0 = p0 - im->policies;
 456                   vlib_increment_combined_counter
 457                     (&ipsec_spd_policy_counters,
 458                      thread_index, pi0, 1,
 459                      clib_net_to_host_u16 (ip0->payload_length) +
 460                      header_size);
 461                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 462                   vnet_buffer (b0)->ipsec.flags = 0;
 463                   next0 = im->ah6_decrypt_next_index;
 464                   goto trace0;
 465                 }
 466               else
 467                 {
 468                   pi0 = ~0;
 469                 }
 470             }
 471
 472         trace0:
 473           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 474               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 475             {
 476               ipsec_input_trace_t *tr =
 477                 vlib_add_trace (vm, node, b0, sizeof (*tr));
 478
 479               if (p0)
 480                 tr->sa_id = p0->sa_id;
 481               tr->proto = ip0->protocol;
 482               tr->spi = clib_net_to_host_u32 (esp0->spi);
 483               tr->seq = clib_net_to_host_u32 (esp0->seq);
 484               tr->spd = spd0->id;
 485             }
 486
 487           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 488                                            n_left_to_next, bi0, next0);
 489         }
 490       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 491     }
 492   vlib_node_increment_counter (vm, ipsec6_input_node.index,
 493                                IPSEC_INPUT_ERROR_RX_PKTS,
 494                                from_frame->n_vectors);
 495
 496   return from_frame->n_vectors;
 497 }
 498
 499
 500 /* *INDENT-OFF* */
 501 VLIB_REGISTER_NODE (ipsec6_input_node,static) = {
 502   .name = "ipsec6-input-feature",
 503   .vector_size = sizeof (u32),
 504   .format_trace = format_ipsec_input_trace,
 505   .type = VLIB_NODE_TYPE_INTERNAL,
 506
 507   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 508   .error_strings = ipsec_input_error_strings,
 509
 510   .sibling_of = "ipsec4-input-feature",
 511 };
 512 /* *INDENT-ON* */
 513
 514 /*
 515  * fd.io coding-style-patch-verification: ON
 516  *
 517  * Local Variables:
 518  * eval: (c-set-style "gnu")
 519  * End:
 520  */