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
  26 #define foreach_ipsec_input_error                   \
  27  _(RX_PKTS, "IPSEC pkts received")                  \
  28  _(DECRYPTION_FAILED, "IPSEC decryption failed")
  29
  30 typedef enum
  31 {
  32 #define _(sym,str) IPSEC_INPUT_ERROR_##sym,
  33   foreach_ipsec_input_error
  34 #undef _
  35     IPSEC_INPUT_N_ERROR,
  36 } ipsec_input_error_t;
  37
  38 static char *ipsec_input_error_strings[] = {
  39 #define _(sym,string) string,
  40   foreach_ipsec_input_error
  41 #undef _
  42 };
  43
  44 typedef struct
  45 {
  46   u32 sa_id;
  47   u32 spi;
  48   u32 seq;
  49 } ipsec_input_trace_t;
  50
  51 /* packet trace format function */
  52 static u8 *
  53 format_ipsec_input_trace (u8 * s, va_list * args)
  54 {
  55   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  56   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  57   ipsec_input_trace_t *t = va_arg (*args, ipsec_input_trace_t *);
  58
  59   if (t->spi == 0 && t->seq == 0)
  60     {
  61       s = format (s, "esp: no esp packet");
  62       return s;
  63     }
  64
  65   if (t->sa_id != 0)
  66     {
  67       s = format (s, "esp: sa_id %u spi %u seq %u", t->sa_id, t->spi, t->seq);
  68     }
  69   else
  70     {
  71       s = format (s, "esp: no sa spi %u seq %u", t->spi, t->seq);
  72     }
  73   return s;
  74 }
  75
  76 always_inline ipsec_policy_t *
  77 ipsec_input_protect_policy_match (ipsec_spd_t * spd, u32 sa, u32 da, u32 spi)
  78 {
  79   ipsec_main_t *im = &ipsec_main;
  80   ipsec_policy_t *p;
  81   ipsec_sa_t *s;
  82   u32 *i;
  83
  84   vec_foreach (i, spd->ipv4_inbound_protect_policy_indices)
  85   {
  86     p = pool_elt_at_index (spd->policies, *i);
  87     s = pool_elt_at_index (im->sad, p->sa_index);
  88
  89     if (spi != s->spi)
  90       continue;
  91
  92     if (s->is_tunnel)
  93       {
  94         if (da != clib_net_to_host_u32 (s->tunnel_dst_addr.ip4.as_u32))
  95           continue;
  96
  97         if (sa != clib_net_to_host_u32 (s->tunnel_src_addr.ip4.as_u32))
  98           continue;
  99
 100         return p;
 101       }
 102
 103     if (da < clib_net_to_host_u32 (p->laddr.start.ip4.as_u32))
 104       continue;
 105
 106     if (da > clib_net_to_host_u32 (p->laddr.stop.ip4.as_u32))
 107       continue;
 108
 109     if (sa < clib_net_to_host_u32 (p->raddr.start.ip4.as_u32))
 110       continue;
 111
 112     if (sa > clib_net_to_host_u32 (p->raddr.stop.ip4.as_u32))
 113       continue;
 114
 115     return p;
 116   }
 117   return 0;
 118 }
 119
 120 always_inline uword
 121 ip6_addr_match_range (ip6_address_t * a, ip6_address_t * la,
 122                       ip6_address_t * ua)
 123 {
 124   if ((memcmp (a->as_u64, la->as_u64, 2 * sizeof (u64)) >= 0) &&
 125       (memcmp (a->as_u64, ua->as_u64, 2 * sizeof (u64)) <= 0))
 126     return 1;
 127   return 0;
 128 }
 129
 130 always_inline ipsec_policy_t *
 131 ipsec_input_ip6_protect_policy_match (ipsec_spd_t * spd,
 132                                       ip6_address_t * sa,
 133                                       ip6_address_t * da, u32 spi)
 134 {
 135   ipsec_main_t *im = &ipsec_main;
 136   ipsec_policy_t *p;
 137   ipsec_sa_t *s;
 138   u32 *i;
 139
 140   vec_foreach (i, spd->ipv6_inbound_protect_policy_indices)
 141   {
 142     p = pool_elt_at_index (spd->policies, *i);
 143     s = pool_elt_at_index (im->sad, p->sa_index);
 144
 145     if (spi != s->spi)
 146       continue;
 147
 148     if (s->is_tunnel)
 149       {
 150         if (!ip6_address_is_equal (sa, &s->tunnel_src_addr.ip6))
 151           continue;
 152
 153         if (!ip6_address_is_equal (da, &s->tunnel_dst_addr.ip6))
 154           continue;
 155
 156         return p;
 157       }
 158
 159     if (!ip6_addr_match_range (sa, &p->raddr.start.ip6, &p->raddr.stop.ip6))
 160       continue;
 161
 162     if (!ip6_addr_match_range (da, &p->laddr.start.ip6, &p->laddr.stop.ip6))
 163       continue;
 164
 165     return p;
 166   }
 167   return 0;
 168 }
 169
 170 static vlib_node_registration_t ipsec_input_ip4_node;
 171
 172 static uword
 173 ipsec_input_ip4_node_fn (vlib_main_t * vm,
 174                          vlib_node_runtime_t * node,
 175                          vlib_frame_t * from_frame)
 176 {
 177   u32 n_left_from, *from, next_index, *to_next;
 178   ipsec_main_t *im = &ipsec_main;
 179
 180   from = vlib_frame_vector_args (from_frame);
 181   n_left_from = from_frame->n_vectors;
 182
 183   next_index = node->cached_next_index;
 184
 185   while (n_left_from > 0)
 186     {
 187       u32 n_left_to_next;
 188
 189       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 190
 191       while (n_left_from > 0 && n_left_to_next > 0)
 192         {
 193           u32 bi0, next0;
 194           vlib_buffer_t *b0;
 195           ip4_header_t *ip0;
 196           esp_header_t *esp0;
 197           ip4_ipsec_config_t *c0;
 198           ipsec_spd_t *spd0;
 199           ipsec_policy_t *p0 = 0;
 200
 201           bi0 = to_next[0] = from[0];
 202           from += 1;
 203           n_left_from -= 1;
 204           to_next += 1;
 205           n_left_to_next -= 1;
 206
 207           b0 = vlib_get_buffer (vm, bi0);
 208           c0 =
 209             vnet_feature_next_with_data (vnet_buffer (b0)->sw_if_index
 210                                          [VLIB_RX], &next0, b0,
 211                                          sizeof (c0[0]));
 212
 213           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 214
 215           ip0 = vlib_buffer_get_current (b0);
 216           esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 217
 218           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
 219             {
 220 #if 0
 221               clib_warning
 222                 ("packet received from %U to %U spi %u size %u spd_id %u",
 223                  format_ip4_address, ip0->src_address.as_u8,
 224                  format_ip4_address, ip0->dst_address.as_u8,
 225                  clib_net_to_host_u32 (esp0->spi),
 226                  clib_net_to_host_u16 (ip0->length), spd0->id);
 227 #endif
 228
 229               p0 = ipsec_input_protect_policy_match (spd0,
 230                                                      clib_net_to_host_u32
 231                                                      (ip0->src_address.
 232                                                       as_u32),
 233                                                      clib_net_to_host_u32
 234                                                      (ip0->dst_address.
 235                                                       as_u32),
 236                                                      clib_net_to_host_u32
 237                                                      (esp0->spi));
 238
 239               if (PREDICT_TRUE (p0 != 0))
 240                 {
 241                   p0->counter.packets++;
 242                   p0->counter.bytes += clib_net_to_host_u16 (ip0->length);
 243                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 244                   vnet_buffer (b0)->ipsec.flags = 0;
 245                   next0 = im->esp_decrypt_next_index;
 246                   vlib_buffer_advance (b0, ip4_header_bytes (ip0));
 247                   goto trace0;
 248                 }
 249             }
 250
 251           /* FIXME bypass and discard */
 252
 253         trace0:
 254           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 255             {
 256               ipsec_input_trace_t *tr =
 257                 vlib_add_trace (vm, node, b0, sizeof (*tr));
 258               if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
 259                 {
 260                   if (p0)
 261                     tr->sa_id = p0->sa_id;
 262                   tr->spi = clib_host_to_net_u32 (esp0->spi);
 263                   tr->seq = clib_host_to_net_u32 (esp0->seq);
 264                 }
 265             }
 266
 267           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 268                                            to_next, n_left_to_next, bi0,
 269                                            next0);
 270         }
 271       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 272     }
 273   vlib_node_increment_counter (vm, ipsec_input_ip4_node.index,
 274                                IPSEC_INPUT_ERROR_RX_PKTS,
 275                                from_frame->n_vectors);
 276
 277   return from_frame->n_vectors;
 278 }
 279
 280
 281 /* *INDENT-OFF* */
 282 VLIB_REGISTER_NODE (ipsec_input_ip4_node,static) = {
 283   .function = ipsec_input_ip4_node_fn,
 284   .name = "ipsec-input-ip4",
 285   .vector_size = sizeof (u32),
 286   .format_trace = format_ipsec_input_trace,
 287   .type = VLIB_NODE_TYPE_INTERNAL,
 288
 289   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 290   .error_strings = ipsec_input_error_strings,
 291
 292   .n_next_nodes = IPSEC_INPUT_N_NEXT,
 293   .next_nodes = {
 294 #define _(s,n) [IPSEC_INPUT_NEXT_##s] = n,
 295     foreach_ipsec_input_next
 296 #undef _
 297   },
 298 };
 299 /* *INDENT-ON* */
 300
 301 VLIB_NODE_FUNCTION_MULTIARCH (ipsec_input_ip4_node, ipsec_input_ip4_node_fn)
 302      static vlib_node_registration_t ipsec_input_ip6_node;
 303
 304      static uword
 305        ipsec_input_ip6_node_fn (vlib_main_t * vm,
 306                                 vlib_node_runtime_t * node,
 307                                 vlib_frame_t * from_frame)
 308 {
 309   u32 n_left_from, *from, next_index, *to_next;
 310   ipsec_main_t *im = &ipsec_main;
 311
 312   from = vlib_frame_vector_args (from_frame);
 313   n_left_from = from_frame->n_vectors;
 314
 315   next_index = node->cached_next_index;
 316
 317   while (n_left_from > 0)
 318     {
 319       u32 n_left_to_next;
 320
 321       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 322
 323       while (n_left_from > 0 && n_left_to_next > 0)
 324         {
 325           u32 bi0, next0;
 326           vlib_buffer_t *b0;
 327           ip6_header_t *ip0;
 328           esp_header_t *esp0;
 329           ip4_ipsec_config_t *c0;
 330           ipsec_spd_t *spd0;
 331           ipsec_policy_t *p0 = 0;
 332           u32 header_size = sizeof (ip0[0]);
 333
 334           bi0 = to_next[0] = from[0];
 335           from += 1;
 336           n_left_from -= 1;
 337           to_next += 1;
 338           n_left_to_next -= 1;
 339
 340           b0 = vlib_get_buffer (vm, bi0);
 341           c0 =
 342             vnet_feature_next_with_data (vnet_buffer (b0)->sw_if_index
 343                                          [VLIB_RX], &next0, b0,
 344                                          sizeof (c0[0]));
 345
 346           spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 347
 348           ip0 = vlib_buffer_get_current (b0);
 349           esp0 = (esp_header_t *) ((u8 *) ip0 + header_size);
 350
 351           if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
 352             {
 353 #if 0
 354               clib_warning
 355                 ("packet received from %U to %U spi %u size %u spd_id %u",
 356                  format_ip6_address, &ip0->src_address, format_ip6_address,
 357                  &ip0->dst_address, clib_net_to_host_u32 (esp0->spi),
 358                  clib_net_to_host_u16 (ip0->payload_length) + header_size,
 359                  spd0->id);
 360 #endif
 361               p0 = ipsec_input_ip6_protect_policy_match (spd0,
 362                                                          &ip0->src_address,
 363                                                          &ip0->dst_address,
 364                                                          clib_net_to_host_u32
 365                                                          (esp0->spi));
 366
 367               if (PREDICT_TRUE (p0 != 0))
 368                 {
 369                   p0->counter.packets++;
 370                   p0->counter.bytes +=
 371                     clib_net_to_host_u16 (ip0->payload_length);
 372                   p0->counter.bytes += header_size;
 373                   vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 374                   vnet_buffer (b0)->ipsec.flags = 0;
 375                   next0 = im->esp_decrypt_next_index;
 376                   vlib_buffer_advance (b0, header_size);
 377                   goto trace0;
 378                 }
 379             }
 380
 381         trace0:
 382           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 383             {
 384               ipsec_input_trace_t *tr =
 385                 vlib_add_trace (vm, node, b0, sizeof (*tr));
 386               if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
 387                 {
 388                   if (p0)
 389                     tr->sa_id = p0->sa_id;
 390                   tr->spi = clib_host_to_net_u32 (esp0->spi);
 391                   tr->seq = clib_host_to_net_u32 (esp0->seq);
 392                 }
 393             }
 394
 395           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 396                                            n_left_to_next, bi0, next0);
 397         }
 398       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 399     }
 400   vlib_node_increment_counter (vm, ipsec_input_ip6_node.index,
 401                                IPSEC_INPUT_ERROR_RX_PKTS,
 402                                from_frame->n_vectors);
 403
 404   return from_frame->n_vectors;
 405 }
 406
 407
 408 /* *INDENT-OFF* */
 409 VLIB_REGISTER_NODE (ipsec_input_ip6_node,static) = {
 410   .function = ipsec_input_ip6_node_fn,
 411   .name = "ipsec-input-ip6",
 412   .vector_size = sizeof (u32),
 413   .format_trace = format_ipsec_input_trace,
 414   .type = VLIB_NODE_TYPE_INTERNAL,
 415
 416   .n_errors = ARRAY_LEN(ipsec_input_error_strings),
 417   .error_strings = ipsec_input_error_strings,
 418
 419   .sibling_of = "ipsec-input-ip4",
 420 };
 421 /* *INDENT-ON* */
 422
 423 VLIB_NODE_FUNCTION_MULTIARCH (ipsec_input_ip6_node, ipsec_input_ip6_node_fn)
 424 /*
 425  * fd.io coding-style-patch-verification: ON
 426  *
 427  * Local Variables:
 428  * eval: (c-set-style "gnu")
 429  * End:
 430  */