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 ipsec_input_ip6_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 ipsec_input_ip4_node;
 172
 173 static uword
 174 ipsec_input_ip4_node_fn (vlib_main_t * vm,
 175                          vlib_node_runtime_t * node,
 176                          vlib_frame_t * from_frame)
 177 {
 178   u32 n_left_from, *from, next_index, *to_next;
 179   ipsec_main_t *im = &ipsec_main;
 180
 181   from = vlib_frame_vector_args (from_frame);
 182   n_left_from = from_frame->n_vectors;
 183
 184   next_index = node->cached_next_index;
 185
 186   while (n_left_from > 0)
 187     {
 188       u32 n_left_to_next;
 189
 190       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 191
 192       while (n_left_from > 0 && n_left_to_next > 0)
 193         {
 194           u32 bi0, next0;
 195           vlib_buffer_t *b0;
 196           ip4_header_t *ip0;
 197           esp_header_t *esp0;
 198           ah_header_t *ah0;
 199           ip4_ipsec_config_t *c0;
 200           ipsec_spd_t *spd0;
 201           ipsec_policy_t *p0 = 0;
 202
 203           bi0 = to_next[0] = from[0];
 204           from += 1;
 205           n_left_from -= 1;
 206           to_next += 1;
 207           n_left_to_next -= 1;
 208
 209           b0 = vlib_get_buffer (vm, bi0);
 210           b0->flags |= VNET_BUFFER_F_IS_IP4;
 211           b0->flags &= ~VNET_BUFFER_F_IS_IP6;
 212           c0 = vnet_feature_next_with_data (&next0, b0, sizeof (c0[0]));
 213
 214           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 215
 216           ip0 = vlib_buffer_get_current (b0);
 217
 218           if (PREDICT_TRUE
 219               (ip0->protocol == IP_PROTOCOL_IPSEC_ESP
 220                || ip0->protocol == IP_PROTOCOL_UDP))
 221             {
 222 #if 0
 223               clib_warning
 224                 ("packet received from %U to %U spi %u size %u spd_id %u",
 225                  format_ip4_address, ip0->src_address.as_u8,
 226                  format_ip4_address, ip0->dst_address.as_u8,
 227                  clib_net_to_host_u32 (esp0->spi),
 228                  clib_net_to_host_u16 (ip0->length), spd0->id);
 229 #endif
 230
 231               esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 232               if (PREDICT_FALSE (ip0->protocol == IP_PROTOCOL_UDP))
 233                 {
 234                   esp0 =
 235                     (esp_header_t *) ((u8 *) esp0 + sizeof (udp_header_t));
 236                 }
 237               /* FIXME TODO missing check whether there is enough data inside
 238                * IP/UDP to contain ESP header & stuff ? */
 239               p0 = ipsec_input_protect_policy_match (spd0,
 240                                                      clib_net_to_host_u32
 241                                                      (ip0->src_address.
 242                                                       as_u32),
 243                                                      clib_net_to_host_u32
 244                                                      (ip0->dst_address.
 245                                                       as_u32),
 246                                                      clib_net_to_host_u32
 247                                                      (esp0->spi));
 248
 249               if (PREDICT_TRUE (p0 != 0))
 250                 {
 251                   p0->counter.packets++;
 252                   p0->counter.bytes += clib_net_to_host_u16 (ip0->length);
 253                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 254                   vnet_buffer (b0)->ipsec.flags = 0;
 255                   next0 = im->esp_decrypt_next_index;
 256                   vlib_buffer_advance (b0, ((u8 *) esp0 - (u8 *) ip0));
 257                   goto trace0;
 258                 }
 259
 260               /* FIXME bypass and discard */
 261             trace0:
 262               if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 263                 {
 264                   ipsec_input_trace_t *tr =
 265                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 266                   if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP ||
 267                       ip0->protocol == IP_PROTOCOL_UDP)
 268                     {
 269                       if (p0)
 270                         tr->sa_id = p0->sa_id;
 271                       tr->spi = clib_host_to_net_u32 (esp0->spi);
 272                       tr->seq = clib_host_to_net_u32 (esp0->seq);
 273                     }
 274                 }
 275
 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                   p0->counter.packets++;
 295                   p0->counter.bytes += clib_net_to_host_u16 (ip0->length);
 296                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 297                   vnet_buffer (b0)->ipsec.flags = 0;
 298                   next0 = im->ah_decrypt_next_index;
 299                   goto trace1;
 300                 }
 301               /* FIXME bypass and discard */
 302             trace1:
 303               if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 304                 {
 305                   ipsec_input_trace_t *tr =
 306                     vlib_add_trace (vm, node, b0, sizeof (*tr));
 307                   if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
 308                     {
 309                       if (p0)
 310                         tr->sa_id = p0->sa_id;
 311                       tr->spi = clib_host_to_net_u32 (ah0->spi);
 312                       tr->seq = clib_host_to_net_u32 (ah0->seq_no);
 313                     }
 314                 }
 315             }
 316
 317           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 318                                            to_next, n_left_to_next, bi0,
 319                                            next0);
 320         }
 321       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 322     }
 323   vlib_node_increment_counter (vm, ipsec_input_ip4_node.index,
 324                                IPSEC_INPUT_ERROR_RX_PKTS,
 325                                from_frame->n_vectors);
 326
 327   return from_frame->n_vectors;
 328 }
 329
 330
 331 /* *INDENT-OFF* */
 332 VLIB_REGISTER_NODE (ipsec_input_ip4_node,static) = {
 333   .function = ipsec_input_ip4_node_fn,
 334   .name = "ipsec-input-ip4",
 335   .vector_size = sizeof (u32),
 336   .format_trace = format_ipsec_input_trace,
 337   .type = VLIB_NODE_TYPE_INTERNAL,
 338
 339   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 340   .error_strings = ipsec_input_error_strings,
 341
 342   .n_next_nodes = IPSEC_INPUT_N_NEXT,
 343   .next_nodes = {
 344 #define _(s,n) [IPSEC_INPUT_NEXT_##s] = n,
 345     foreach_ipsec_input_next
 346 #undef _
 347   },
 348 };
 349 /* *INDENT-ON* */
 350
 351 VLIB_NODE_FUNCTION_MULTIARCH (ipsec_input_ip4_node, ipsec_input_ip4_node_fn)
 352      static vlib_node_registration_t ipsec_input_ip6_node;
 353
 354      static uword
 355        ipsec_input_ip6_node_fn (vlib_main_t * vm,
 356                                 vlib_node_runtime_t * node,
 357                                 vlib_frame_t * from_frame)
 358 {
 359   u32 n_left_from, *from, next_index, *to_next;
 360   ipsec_main_t *im = &ipsec_main;
 361
 362   from = vlib_frame_vector_args (from_frame);
 363   n_left_from = from_frame->n_vectors;
 364
 365   next_index = node->cached_next_index;
 366
 367   while (n_left_from > 0)
 368     {
 369       u32 n_left_to_next;
 370
 371       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 372
 373       while (n_left_from > 0 && n_left_to_next > 0)
 374         {
 375           u32 bi0, next0;
 376           vlib_buffer_t *b0;
 377           ip6_header_t *ip0;
 378           esp_header_t *esp0;
 379           ip4_ipsec_config_t *c0;
 380           ipsec_spd_t *spd0;
 381           ipsec_policy_t *p0 = 0;
 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
 400           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
 401             {
 402 #if 0
 403               clib_warning
 404                 ("packet received from %U to %U spi %u size %u spd_id %u",
 405                  format_ip6_address, &ip0->src_address, format_ip6_address,
 406                  &ip0->dst_address, clib_net_to_host_u32 (esp0->spi),
 407                  clib_net_to_host_u16 (ip0->payload_length) + header_size,
 408                  spd0->id);
 409 #endif
 410               p0 = ipsec_input_ip6_protect_policy_match (spd0,
 411                                                          &ip0->src_address,
 412                                                          &ip0->dst_address,
 413                                                          clib_net_to_host_u32
 414                                                          (esp0->spi));
 415
 416               if (PREDICT_TRUE (p0 != 0))
 417                 {
 418                   p0->counter.packets++;
 419                   p0->counter.bytes +=
 420                     clib_net_to_host_u16 (ip0->payload_length);
 421                   p0->counter.bytes += header_size;
 422                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 423                   vnet_buffer (b0)->ipsec.flags = 0;
 424                   next0 = im->esp_decrypt_next_index;
 425                   vlib_buffer_advance (b0, header_size);
 426                   goto trace0;
 427                 }
 428             }
 429
 430         trace0:
 431           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 432             {
 433               ipsec_input_trace_t *tr =
 434                 vlib_add_trace (vm, node, b0, sizeof (*tr));
 435               if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
 436                 {
 437                   if (p0)
 438                     tr->sa_id = p0->sa_id;
 439                   tr->spi = clib_host_to_net_u32 (esp0->spi);
 440                   tr->seq = clib_host_to_net_u32 (esp0->seq);
 441                 }
 442             }
 443
 444           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 445                                            n_left_to_next, bi0, next0);
 446         }
 447       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 448     }
 449   vlib_node_increment_counter (vm, ipsec_input_ip6_node.index,
 450                                IPSEC_INPUT_ERROR_RX_PKTS,
 451                                from_frame->n_vectors);
 452
 453   return from_frame->n_vectors;
 454 }
 455
 456
 457 /* *INDENT-OFF* */
 458 VLIB_REGISTER_NODE (ipsec_input_ip6_node,static) = {
 459   .function = ipsec_input_ip6_node_fn,
 460   .name = "ipsec-input-ip6",
 461   .vector_size = sizeof (u32),
 462   .format_trace = format_ipsec_input_trace,
 463   .type = VLIB_NODE_TYPE_INTERNAL,
 464
 465   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 466   .error_strings = ipsec_input_error_strings,
 467
 468   .sibling_of = "ipsec-input-ip4",
 469 };
 470 /* *INDENT-ON* */
 471
 472 VLIB_NODE_FUNCTION_MULTIARCH (ipsec_input_ip6_node, ipsec_input_ip6_node_fn)
 473 /*
 474  * fd.io coding-style-patch-verification: ON
 475  *
 476  * Local Variables:
 477  * eval: (c-set-style "gnu")
 478  * End:
 479  */