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 spd;
  48   u32 sa_id;
  49   u32 spi;
  50   u32 seq;
  51 } ipsec_input_trace_t;
  52
  53 /* packet trace format function */
  54 static u8 *
  55 format_ipsec_input_trace (u8 * s, va_list * args)
  56 {
  57   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  58   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  59   ipsec_input_trace_t *t = va_arg (*args, ipsec_input_trace_t *);
  60
  61   if (t->spi == 0 && t->seq == 0)
  62     {
  63       s = format (s, "esp: no esp packet");
  64       return s;
  65     }
  66
  67   if (t->sa_id != 0)
  68     {
  69       s =
  70         format (s, "esp: sa_id %u spd %u spi %u seq %u", t->sa_id, t->spd,
  71                 t->spi, t->seq);
  72     }
  73   else
  74     {
  75       s =
  76         format (s, "esp: no sa spd %u spi %u seq %u", t->spd, t->spi, t->seq);
  77     }
  78   return s;
  79 }
  80
  81 always_inline ipsec_policy_t *
  82 ipsec_input_protect_policy_match (ipsec_spd_t * spd, u32 sa, u32 da, u32 spi)
  83 {
  84   ipsec_main_t *im = &ipsec_main;
  85   ipsec_policy_t *p;
  86   ipsec_sa_t *s;
  87   u32 *i;
  88
  89   vec_foreach (i, spd->ipv4_inbound_protect_policy_indices)
  90   {
  91     p = pool_elt_at_index (spd->policies, *i);
  92     s = pool_elt_at_index (im->sad, p->sa_index);
  93
  94     if (spi != s->spi)
  95       continue;
  96
  97     if (s->is_tunnel)
  98       {
  99         if (da != clib_net_to_host_u32 (s->tunnel_dst_addr.ip4.as_u32))
 100           continue;
 101
 102         if (sa != clib_net_to_host_u32 (s->tunnel_src_addr.ip4.as_u32))
 103           continue;
 104
 105         return p;
 106       }
 107
 108     if (da < clib_net_to_host_u32 (p->laddr.start.ip4.as_u32))
 109       continue;
 110
 111     if (da > clib_net_to_host_u32 (p->laddr.stop.ip4.as_u32))
 112       continue;
 113
 114     if (sa < clib_net_to_host_u32 (p->raddr.start.ip4.as_u32))
 115       continue;
 116
 117     if (sa > clib_net_to_host_u32 (p->raddr.stop.ip4.as_u32))
 118       continue;
 119
 120     return p;
 121   }
 122   return 0;
 123 }
 124
 125 always_inline uword
 126 ip6_addr_match_range (ip6_address_t * a, ip6_address_t * la,
 127                       ip6_address_t * ua)
 128 {
 129   if ((memcmp (a->as_u64, la->as_u64, 2 * sizeof (u64)) >= 0) &&
 130       (memcmp (a->as_u64, ua->as_u64, 2 * sizeof (u64)) <= 0))
 131     return 1;
 132   return 0;
 133 }
 134
 135 always_inline ipsec_policy_t *
 136 ipsec6_input_protect_policy_match (ipsec_spd_t * spd,
 137                                    ip6_address_t * sa,
 138                                    ip6_address_t * da, u32 spi)
 139 {
 140   ipsec_main_t *im = &ipsec_main;
 141   ipsec_policy_t *p;
 142   ipsec_sa_t *s;
 143   u32 *i;
 144
 145   vec_foreach (i, spd->ipv6_inbound_protect_policy_indices)
 146   {
 147     p = pool_elt_at_index (spd->policies, *i);
 148     s = pool_elt_at_index (im->sad, p->sa_index);
 149
 150     if (spi != s->spi)
 151       continue;
 152
 153     if (s->is_tunnel)
 154       {
 155         if (!ip6_address_is_equal (sa, &s->tunnel_src_addr.ip6))
 156           continue;
 157
 158         if (!ip6_address_is_equal (da, &s->tunnel_dst_addr.ip6))
 159           continue;
 160
 161         return p;
 162       }
 163
 164     if (!ip6_addr_match_range (sa, &p->raddr.start.ip6, &p->raddr.stop.ip6))
 165       continue;
 166
 167     if (!ip6_addr_match_range (da, &p->laddr.start.ip6, &p->laddr.stop.ip6))
 168       continue;
 169
 170     return p;
 171   }
 172   return 0;
 173 }
 174
 175 static vlib_node_registration_t ipsec4_input_node;
 176
 177 VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm,
 178                                   vlib_node_runtime_t * node,
 179                                   vlib_frame_t * from_frame)
 180 {
 181   u32 n_left_from, *from, next_index, *to_next;
 182   ipsec_main_t *im = &ipsec_main;
 183
 184   from = vlib_frame_vector_args (from_frame);
 185   n_left_from = from_frame->n_vectors;
 186
 187   next_index = node->cached_next_index;
 188
 189   while (n_left_from > 0)
 190     {
 191       u32 n_left_to_next;
 192
 193       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 194
 195       while (n_left_from > 0 && n_left_to_next > 0)
 196         {
 197           u32 bi0, next0;
 198           vlib_buffer_t *b0;
 199           ip4_header_t *ip0;
 200           esp_header_t *esp0;
 201           ah_header_t *ah0;
 202           ip4_ipsec_config_t *c0;
 203           ipsec_spd_t *spd0;
 204           ipsec_policy_t *p0 = 0;
 205
 206           bi0 = to_next[0] = from[0];
 207           from += 1;
 208           n_left_from -= 1;
 209           to_next += 1;
 210           n_left_to_next -= 1;
 211
 212           b0 = vlib_get_buffer (vm, bi0);
 213           b0->flags |= VNET_BUFFER_F_IS_IP4;
 214           b0->flags &= ~VNET_BUFFER_F_IS_IP6;
 215           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 216
 217           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 218
 219           ip0 = vlib_buffer_get_current (b0);
 220
 221           if (PREDICT_TRUE
 222               (ip0->protocol == IP_PROTOCOL_IPSEC_ESP
 223                || ip0->protocol == IP_PROTOCOL_UDP))
 224             {
 225 #if 0
 226               clib_warning
 227                 ("packet received from %U to %U spi %u size %u spd_id %u",
 228                  format_ip4_address, ip0->src_address.as_u8,
 229                  format_ip4_address, ip0->dst_address.as_u8,
 230                  clib_net_to_host_u32 (esp0->spi),
 231                  clib_net_to_host_u16 (ip0->length), spd0->id);
 232 #endif
 233
 234               esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 235               if (PREDICT_FALSE (ip0->protocol == IP_PROTOCOL_UDP))
 236                 {
 237                   esp0 =
 238                     (esp_header_t *) ((u8 *) esp0 + sizeof (udp_header_t));
 239                 }
 240               /* FIXME TODO missing check whether there is enough data inside
 241                * IP/UDP to contain ESP header & stuff ? */
 242               p0 = ipsec_input_protect_policy_match (spd0,
 243                                                      clib_net_to_host_u32
 244                                                      (ip0->src_address.
 245                                                       as_u32),
 246                                                      clib_net_to_host_u32
 247                                                      (ip0->dst_address.
 248                                                       as_u32),
 249                                                      clib_net_to_host_u32
 250                                                      (esp0->spi));
 251
 252               if (PREDICT_TRUE (p0 != 0))
 253                 {
 254                   p0->counter.packets++;
 255                   p0->counter.bytes += clib_net_to_host_u16 (ip0->length);
 256                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 257                   vnet_buffer (b0)->ipsec.flags = 0;
 258                   next0 = im->esp4_decrypt_next_index;
 259                   vlib_buffer_advance (b0, ((u8 *) esp0 - (u8 *) ip0));
 260                   goto trace0;
 261                 }
 262
 263               /* FIXME bypass and discard */
 264             trace0:
 265               if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 266                 {
 267                   ipsec_input_trace_t *tr =
 268                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 269                   if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP ||
 270                       ip0->protocol == IP_PROTOCOL_UDP)
 271                     {
 272                       if (p0)
 273                         tr->sa_id = p0->sa_id;
 274                       tr->spi = clib_host_to_net_u32 (esp0->spi);
 275                       tr->seq = clib_host_to_net_u32 (esp0->seq);
 276                       tr->spd = spd0->id;
 277                     }
 278                 }
 279
 280             }
 281
 282
 283           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_AH))
 284             {
 285               ah0 = (ah_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 286               p0 = ipsec_input_protect_policy_match (spd0,
 287                                                      clib_net_to_host_u32
 288                                                      (ip0->src_address.
 289                                                       as_u32),
 290                                                      clib_net_to_host_u32
 291                                                      (ip0->dst_address.
 292                                                       as_u32),
 293                                                      clib_net_to_host_u32
 294                                                      (ah0->spi));
 295
 296               if (PREDICT_TRUE (p0 != 0))
 297                 {
 298                   p0->counter.packets++;
 299                   p0->counter.bytes += clib_net_to_host_u16 (ip0->length);
 300                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 301                   vnet_buffer (b0)->ipsec.flags = 0;
 302                   next0 = im->ah4_decrypt_next_index;
 303                   goto trace1;
 304                 }
 305               /* FIXME bypass and discard */
 306             trace1:
 307               if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 308                 {
 309                   ipsec_input_trace_t *tr =
 310                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 311                   if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
 312                     {
 313                       if (p0)
 314                         tr->sa_id = p0->sa_id;
 315                       tr->spi = clib_host_to_net_u32 (ah0->spi);
 316                       tr->seq = clib_host_to_net_u32 (ah0->seq_no);
 317                       tr->spd = spd0->id;
 318                     }
 319                 }
 320             }
 321
 322           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 323                                            to_next, n_left_to_next, bi0,
 324                                            next0);
 325         }
 326       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 327     }
 328   vlib_node_increment_counter (vm, ipsec4_input_node.index,
 329                                IPSEC_INPUT_ERROR_RX_PKTS,
 330                                from_frame->n_vectors);
 331
 332   return from_frame->n_vectors;
 333 }
 334
 335
 336 /* *INDENT-OFF* */
 337 VLIB_REGISTER_NODE (ipsec4_input_node,static) = {
 338   .name = "ipsec4-input",
 339   .vector_size = sizeof (u32),
 340   .format_trace = format_ipsec_input_trace,
 341   .type = VLIB_NODE_TYPE_INTERNAL,
 342
 343   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 344   .error_strings = ipsec_input_error_strings,
 345
 346   .n_next_nodes = IPSEC_INPUT_N_NEXT,
 347   .next_nodes = {
 348 #define _(s,n) [IPSEC_INPUT_NEXT_##s] = n,
 349     foreach_ipsec_input_next
 350 #undef _
 351   },
 352 };
 353 /* *INDENT-ON* */
 354
 355 static vlib_node_registration_t ipsec6_input_node;
 356
 357
 358 VLIB_NODE_FN (ipsec6_input_node) (vlib_main_t * vm,
 359                                   vlib_node_runtime_t * node,
 360                                   vlib_frame_t * from_frame)
 361 {
 362   u32 n_left_from, *from, next_index, *to_next;
 363   ipsec_main_t *im = &ipsec_main;
 364
 365   from = vlib_frame_vector_args (from_frame);
 366   n_left_from = from_frame->n_vectors;
 367
 368   next_index = node->cached_next_index;
 369
 370   while (n_left_from > 0)
 371     {
 372       u32 n_left_to_next;
 373
 374       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 375
 376       while (n_left_from > 0 && n_left_to_next > 0)
 377         {
 378           u32 bi0, next0;
 379           vlib_buffer_t *b0;
 380           ip6_header_t *ip0;
 381           esp_header_t *esp0;
 382           ip4_ipsec_config_t *c0;
 383           ipsec_spd_t *spd0;
 384           ipsec_policy_t *p0 = 0;
 385           ah_header_t *ah0;
 386           u32 header_size = sizeof (ip0[0]);
 387
 388           bi0 = to_next[0] = from[0];
 389           from += 1;
 390           n_left_from -= 1;
 391           to_next += 1;
 392           n_left_to_next -= 1;
 393
 394           b0 = vlib_get_buffer (vm, bi0);
 395           b0->flags |= VNET_BUFFER_F_IS_IP6;
 396           b0->flags &= ~VNET_BUFFER_F_IS_IP4;
 397           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 398
 399           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 400
 401           ip0 = vlib_buffer_get_current (b0);
 402           esp0 = (esp_header_t *) ((u8 *) ip0 + header_size);
 403           ah0 = (ah_header_t *) ((u8 *) ip0 + header_size);
 404
 405           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
 406             {
 407 #if 0
 408               clib_warning
 409                 ("packet received from %U to %U spi %u size %u spd_id %u",
 410                  format_ip6_address, &ip0->src_address, format_ip6_address,
 411                  &ip0->dst_address, clib_net_to_host_u32 (esp0->spi),
 412                  clib_net_to_host_u16 (ip0->payload_length) + header_size,
 413                  spd0->id);
 414 #endif
 415               p0 = ipsec6_input_protect_policy_match (spd0,
 416                                                       &ip0->src_address,
 417                                                       &ip0->dst_address,
 418                                                       clib_net_to_host_u32
 419                                                       (esp0->spi));
 420
 421               if (PREDICT_TRUE (p0 != 0))
 422                 {
 423                   p0->counter.packets++;
 424                   p0->counter.bytes +=
 425                     clib_net_to_host_u16 (ip0->payload_length);
 426                   p0->counter.bytes += header_size;
 427                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 428                   vnet_buffer (b0)->ipsec.flags = 0;
 429                   next0 = im->esp6_decrypt_next_index;
 430                   vlib_buffer_advance (b0, header_size);
 431                   goto trace0;
 432                 }
 433             }
 434           else if (ip0->protocol == IP_PROTOCOL_IPSEC_AH)
 435             {
 436               p0 = ipsec6_input_protect_policy_match (spd0,
 437                                                       &ip0->src_address,
 438                                                       &ip0->dst_address,
 439                                                       clib_net_to_host_u32
 440                                                       (ah0->spi));
 441
 442               if (PREDICT_TRUE (p0 != 0))
 443                 {
 444                   p0->counter.packets++;
 445                   p0->counter.bytes +=
 446                     clib_net_to_host_u16 (ip0->payload_length);
 447                   p0->counter.bytes += header_size;
 448                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 449                   vnet_buffer (b0)->ipsec.flags = 0;
 450                   next0 = im->ah6_decrypt_next_index;
 451                   goto trace0;
 452                 }
 453             }
 454
 455         trace0:
 456           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 457             {
 458               ipsec_input_trace_t *tr =
 459                 vlib_add_trace (vm, node, b0, sizeof (*tr));
 460               if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
 461                 {
 462                   if (p0)
 463                     tr->sa_id = p0->sa_id;
 464                   tr->spi = clib_host_to_net_u32 (esp0->spi);
 465                   tr->seq = clib_host_to_net_u32 (esp0->seq);
 466                   tr->spd = spd0->id;
 467                 }
 468             }
 469
 470           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 471                                            n_left_to_next, bi0, next0);
 472         }
 473       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 474     }
 475   vlib_node_increment_counter (vm, ipsec6_input_node.index,
 476                                IPSEC_INPUT_ERROR_RX_PKTS,
 477                                from_frame->n_vectors);
 478
 479   return from_frame->n_vectors;
 480 }
 481
 482
 483 /* *INDENT-OFF* */
 484 VLIB_REGISTER_NODE (ipsec6_input_node,static) = {
 485   .name = "ipsec6-input",
 486   .vector_size = sizeof (u32),
 487   .format_trace = format_ipsec_input_trace,
 488   .type = VLIB_NODE_TYPE_INTERNAL,
 489
 490   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 491   .error_strings = ipsec_input_error_strings,
 492
 493   .sibling_of = "ipsec4-input",
 494 };
 495 /* *INDENT-ON* */
 496
 497 /*
 498  * fd.io coding-style-patch-verification: ON
 499  *
 500  * Local Variables:
 501  * eval: (c-set-style "gnu")
 502  * End:
 503  */