src/vnet/ipsec/esp_encrypt.c

   1 /*
   2  * esp_encrypt.c : IPSec ESP encrypt node
   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/udp/udp.h>
  22
  23 #include <vnet/ipsec/ipsec.h>
  24 #include <vnet/ipsec/esp.h>
  25
  26 #ifndef CLIB_MARCH_VARIANT
  27 ipsec_proto_main_t ipsec_proto_main;
  28 #endif /* CLIB_MARCH_VARIANT */
  29
  30 #define foreach_esp_encrypt_next                   \
  31 _(DROP, "error-drop")                              \
  32 _(IP4_LOOKUP, "ip4-lookup")                        \
  33 _(IP6_LOOKUP, "ip6-lookup")                        \
  34 _(INTERFACE_OUTPUT, "interface-output")
  35
  36 #define _(v, s) ESP_ENCRYPT_NEXT_##v,
  37 typedef enum
  38 {
  39   foreach_esp_encrypt_next
  40 #undef _
  41     ESP_ENCRYPT_N_NEXT,
  42 } esp_encrypt_next_t;
  43
  44 #define foreach_esp_encrypt_error                   \
  45  _(RX_PKTS, "ESP pkts received")                    \
  46  _(NO_BUFFER, "No buffer (packet dropped)")         \
  47  _(DECRYPTION_FAILED, "ESP encryption failed")      \
  48  _(SEQ_CYCLED, "sequence number cycled")
  49
  50
  51 typedef enum
  52 {
  53 #define _(sym,str) ESP_ENCRYPT_ERROR_##sym,
  54   foreach_esp_encrypt_error
  55 #undef _
  56     ESP_ENCRYPT_N_ERROR,
  57 } esp_encrypt_error_t;
  58
  59 static char *esp_encrypt_error_strings[] = {
  60 #define _(sym,string) string,
  61   foreach_esp_encrypt_error
  62 #undef _
  63 };
  64
  65 typedef struct
  66 {
  67   u32 sa_index;
  68   u32 spi;
  69   u32 seq;
  70   u8 udp_encap;
  71   ipsec_crypto_alg_t crypto_alg;
  72   ipsec_integ_alg_t integ_alg;
  73 } esp_encrypt_trace_t;
  74
  75 /* packet trace format function */
  76 static u8 *
  77 format_esp_encrypt_trace (u8 * s, va_list * args)
  78 {
  79   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  80   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  81   esp_encrypt_trace_t *t = va_arg (*args, esp_encrypt_trace_t *);
  82
  83   s = format (s, "esp: sa-index %d spi %u seq %u crypto %U integrity %U%s",
  84               t->sa_index, t->spi, t->seq,
  85               format_ipsec_crypto_alg, t->crypto_alg,
  86               format_ipsec_integ_alg, t->integ_alg,
  87               t->udp_encap ? " udp-encap-enabled" : "");
  88   return s;
  89 }
  90
  91 always_inline void
  92 esp_encrypt_cbc (vlib_main_t * vm, ipsec_crypto_alg_t alg,
  93                  u8 * in, u8 * out, size_t in_len, u8 * key, u8 * iv)
  94 {
  95   ipsec_proto_main_t *em = &ipsec_proto_main;
  96   u32 thread_index = vm->thread_index;
  97 #if OPENSSL_VERSION_NUMBER >= 0x10100000L
  98   EVP_CIPHER_CTX *ctx = em->per_thread_data[thread_index].encrypt_ctx;
  99 #else
 100   EVP_CIPHER_CTX *ctx = &(em->per_thread_data[thread_index].encrypt_ctx);
 101 #endif
 102   const EVP_CIPHER *cipher = NULL;
 103   int out_len;
 104
 105   ASSERT (alg < IPSEC_CRYPTO_N_ALG);
 106
 107   if (PREDICT_FALSE
 108       (em->ipsec_proto_main_crypto_algs[alg].type == IPSEC_CRYPTO_ALG_NONE))
 109     return;
 110
 111   if (PREDICT_FALSE
 112       (alg != em->per_thread_data[thread_index].last_encrypt_alg))
 113     {
 114       cipher = em->ipsec_proto_main_crypto_algs[alg].type;
 115       em->per_thread_data[thread_index].last_encrypt_alg = alg;
 116     }
 117
 118   EVP_EncryptInit_ex (ctx, cipher, NULL, key, iv);
 119
 120   EVP_EncryptUpdate (ctx, out, &out_len, in, in_len);
 121   EVP_EncryptFinal_ex (ctx, out + out_len, &out_len);
 122 }
 123
 124 always_inline uword
 125 esp_encrypt_inline (vlib_main_t * vm,
 126                     vlib_node_runtime_t * node, vlib_frame_t * from_frame,
 127                     int is_ip6)
 128 {
 129   u32 n_left_from, *from, *to_next = 0, next_index;
 130   from = vlib_frame_vector_args (from_frame);
 131   n_left_from = from_frame->n_vectors;
 132   ipsec_main_t *im = &ipsec_main;
 133   ipsec_proto_main_t *em = &ipsec_proto_main;
 134   u32 *recycle = 0;
 135   u32 thread_index = vm->thread_index;
 136
 137   ipsec_alloc_empty_buffers (vm, im);
 138
 139   u32 *empty_buffers = im->empty_buffers[thread_index];
 140
 141   if (PREDICT_FALSE (vec_len (empty_buffers) < n_left_from))
 142     {
 143       vlib_node_increment_counter (vm, node->node_index,
 144                                    ESP_ENCRYPT_ERROR_NO_BUFFER, n_left_from);
 145       clib_warning ("not enough empty buffers. discarding frame");
 146       goto free_buffers_and_exit;
 147     }
 148
 149   next_index = node->cached_next_index;
 150
 151   while (n_left_from > 0)
 152     {
 153       u32 n_left_to_next;
 154
 155       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 156
 157       while (n_left_from > 0 && n_left_to_next > 0)
 158         {
 159           u32 i_bi0, o_bi0, next0;
 160           vlib_buffer_t *i_b0, *o_b0 = 0;
 161           u32 sa_index0;
 162           ipsec_sa_t *sa0;
 163           ip4_and_esp_header_t *oh0 = 0;
 164           ip6_and_esp_header_t *ih6_0, *oh6_0 = 0;
 165           ip4_and_udp_and_esp_header_t *iuh0, *ouh0 = 0;
 166           uword last_empty_buffer;
 167           esp_header_t *o_esp0;
 168           esp_footer_t *f0;
 169           u8 ip_udp_hdr_size;
 170           u8 next_hdr_type;
 171           u32 ip_proto = 0;
 172           u8 transport_mode = 0;
 173
 174           i_bi0 = from[0];
 175           from += 1;
 176           n_left_from -= 1;
 177           n_left_to_next -= 1;
 178
 179           next0 = ESP_ENCRYPT_NEXT_DROP;
 180
 181           i_b0 = vlib_get_buffer (vm, i_bi0);
 182           sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
 183           sa0 = pool_elt_at_index (im->sad, sa_index0);
 184
 185           vlib_prefetch_combined_counter
 186             (&ipsec_sa_counters, thread_index, sa_index0);
 187
 188           if (PREDICT_FALSE (esp_seq_advance (sa0)))
 189             {
 190               clib_warning ("sequence number counter has cycled SPI %u",
 191                             sa0->spi);
 192               vlib_node_increment_counter (vm, node->node_index,
 193                                            ESP_ENCRYPT_ERROR_SEQ_CYCLED, 1);
 194               //TODO: rekey SA
 195               o_bi0 = i_bi0;
 196               to_next[0] = o_bi0;
 197               to_next += 1;
 198               goto trace;
 199             }
 200
 201           /* grab free buffer */
 202           last_empty_buffer = vec_len (empty_buffers) - 1;
 203           o_bi0 = empty_buffers[last_empty_buffer];
 204           o_b0 = vlib_get_buffer (vm, o_bi0);
 205           o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 206           o_b0->current_data = sizeof (ethernet_header_t);
 207           iuh0 = vlib_buffer_get_current (i_b0);
 208           vlib_prefetch_buffer_with_index (vm,
 209                                            empty_buffers[last_empty_buffer -
 210                                                          1], STORE);
 211           _vec_len (empty_buffers) = last_empty_buffer;
 212           to_next[0] = o_bi0;
 213           to_next += 1;
 214
 215           /* add old buffer to the recycle list */
 216           vec_add1 (recycle, i_bi0);
 217
 218           if (is_ip6)
 219             {
 220               ih6_0 = vlib_buffer_get_current (i_b0);
 221               next_hdr_type = IP_PROTOCOL_IPV6;
 222               oh6_0 = vlib_buffer_get_current (o_b0);
 223
 224               oh6_0->ip6.ip_version_traffic_class_and_flow_label =
 225                 ih6_0->ip6.ip_version_traffic_class_and_flow_label;
 226               oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_ESP;
 227               ip_udp_hdr_size = sizeof (ip6_header_t);
 228               o_esp0 = vlib_buffer_get_current (o_b0) + ip_udp_hdr_size;
 229               oh6_0->ip6.hop_limit = 254;
 230               oh6_0->ip6.src_address.as_u64[0] =
 231                 ih6_0->ip6.src_address.as_u64[0];
 232               oh6_0->ip6.src_address.as_u64[1] =
 233                 ih6_0->ip6.src_address.as_u64[1];
 234               oh6_0->ip6.dst_address.as_u64[0] =
 235                 ih6_0->ip6.dst_address.as_u64[0];
 236               oh6_0->ip6.dst_address.as_u64[1] =
 237                 ih6_0->ip6.dst_address.as_u64[1];
 238               o_esp0->spi = clib_net_to_host_u32 (sa0->spi);
 239               o_esp0->seq = clib_net_to_host_u32 (sa0->seq);
 240               ip_proto = ih6_0->ip6.protocol;
 241
 242               next0 = ESP_ENCRYPT_NEXT_IP6_LOOKUP;
 243             }
 244           else
 245             {
 246               next_hdr_type = IP_PROTOCOL_IP_IN_IP;
 247               oh0 = vlib_buffer_get_current (o_b0);
 248               ouh0 = vlib_buffer_get_current (o_b0);
 249
 250               oh0->ip4.ip_version_and_header_length = 0x45;
 251               oh0->ip4.tos = iuh0->ip4.tos;
 252               oh0->ip4.fragment_id = 0;
 253               oh0->ip4.flags_and_fragment_offset = 0;
 254               oh0->ip4.ttl = 254;
 255               if (sa0->udp_encap)
 256                 {
 257                   ouh0->udp.src_port =
 258                     clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
 259                   ouh0->udp.dst_port =
 260                     clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
 261                   ouh0->udp.checksum = 0;
 262                   ouh0->ip4.protocol = IP_PROTOCOL_UDP;
 263                   ip_udp_hdr_size =
 264                     sizeof (udp_header_t) + sizeof (ip4_header_t);
 265                 }
 266               else
 267                 {
 268                   oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
 269                   ip_udp_hdr_size = sizeof (ip4_header_t);
 270                 }
 271               o_esp0 = vlib_buffer_get_current (o_b0) + ip_udp_hdr_size;
 272               oh0->ip4.src_address.as_u32 = iuh0->ip4.src_address.as_u32;
 273               oh0->ip4.dst_address.as_u32 = iuh0->ip4.dst_address.as_u32;
 274               o_esp0->spi = clib_net_to_host_u32 (sa0->spi);
 275               o_esp0->seq = clib_net_to_host_u32 (sa0->seq);
 276               ip_proto = iuh0->ip4.protocol;
 277
 278               next0 = ESP_ENCRYPT_NEXT_IP4_LOOKUP;
 279             }
 280
 281           if (PREDICT_TRUE (!is_ip6 && sa0->is_tunnel && !sa0->is_tunnel_ip6))
 282             {
 283               oh0->ip4.src_address.as_u32 = sa0->tunnel_src_addr.ip4.as_u32;
 284               oh0->ip4.dst_address.as_u32 = sa0->tunnel_dst_addr.ip4.as_u32;
 285
 286               next0 = sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_next_node;
 287               vnet_buffer (o_b0)->ip.adj_index[VLIB_TX] =
 288                 sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_index;
 289             }
 290           else if (is_ip6 && sa0->is_tunnel && sa0->is_tunnel_ip6)
 291             {
 292               oh6_0->ip6.src_address.as_u64[0] =
 293                 sa0->tunnel_src_addr.ip6.as_u64[0];
 294               oh6_0->ip6.src_address.as_u64[1] =
 295                 sa0->tunnel_src_addr.ip6.as_u64[1];
 296               oh6_0->ip6.dst_address.as_u64[0] =
 297                 sa0->tunnel_dst_addr.ip6.as_u64[0];
 298               oh6_0->ip6.dst_address.as_u64[1] =
 299                 sa0->tunnel_dst_addr.ip6.as_u64[1];
 300
 301               next0 = sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_next_node;
 302               vnet_buffer (o_b0)->ip.adj_index[VLIB_TX] =
 303                 sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_index;
 304             }
 305           else
 306             {
 307               next_hdr_type = ip_proto;
 308               if (vnet_buffer (i_b0)->sw_if_index[VLIB_TX] != ~0)
 309                 {
 310                   transport_mode = 1;
 311                   ethernet_header_t *ieh0, *oeh0;
 312                   ieh0 =
 313                     (ethernet_header_t *) ((u8 *)
 314                                            vlib_buffer_get_current (i_b0) -
 315                                            sizeof (ethernet_header_t));
 316                   oeh0 = (ethernet_header_t *) o_b0->data;
 317                   clib_memcpy_fast (oeh0, ieh0, sizeof (ethernet_header_t));
 318                   next0 = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
 319                   vnet_buffer (o_b0)->sw_if_index[VLIB_TX] =
 320                     vnet_buffer (i_b0)->sw_if_index[VLIB_TX];
 321                 }
 322
 323               if (is_ip6)
 324                 {
 325                   vlib_buffer_advance (i_b0, sizeof (ip6_header_t));
 326                 }
 327               else
 328                 {
 329                   vlib_buffer_advance (i_b0, sizeof (ip4_header_t));
 330                 }
 331             }
 332
 333           ASSERT (sa0->crypto_alg < IPSEC_CRYPTO_N_ALG);
 334           vlib_increment_combined_counter
 335             (&ipsec_sa_counters, thread_index, sa_index0,
 336              1, i_b0->current_length);
 337
 338           if (PREDICT_TRUE (sa0->crypto_alg != IPSEC_CRYPTO_ALG_NONE))
 339             {
 340
 341               const int BLOCK_SIZE =
 342                 em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].block_size;
 343               const int IV_SIZE =
 344                 em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size;
 345               int blocks = 1 + (i_b0->current_length + 1) / BLOCK_SIZE;
 346
 347               /* pad packet in input buffer */
 348               u8 pad_bytes = BLOCK_SIZE * blocks - 2 - i_b0->current_length;
 349               u8 i;
 350               u8 *padding =
 351                 vlib_buffer_get_current (i_b0) + i_b0->current_length;
 352               i_b0->current_length = BLOCK_SIZE * blocks;
 353               for (i = 0; i < pad_bytes; ++i)
 354                 {
 355                   padding[i] = i + 1;
 356                 }
 357               f0 = vlib_buffer_get_current (i_b0) + i_b0->current_length - 2;
 358               f0->pad_length = pad_bytes;
 359               f0->next_header = next_hdr_type;
 360
 361               o_b0->current_length = ip_udp_hdr_size + sizeof (esp_header_t) +
 362                 BLOCK_SIZE * blocks + IV_SIZE;
 363
 364               vnet_buffer (o_b0)->sw_if_index[VLIB_RX] =
 365                 vnet_buffer (i_b0)->sw_if_index[VLIB_RX];
 366
 367               u8 iv[em->
 368                     ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size];
 369               RAND_bytes (iv, sizeof (iv));
 370
 371               clib_memcpy_fast ((u8 *) vlib_buffer_get_current (o_b0) +
 372                                 ip_udp_hdr_size + sizeof (esp_header_t), iv,
 373                                 em->ipsec_proto_main_crypto_algs[sa0->
 374                                                                  crypto_alg].iv_size);
 375
 376               esp_encrypt_cbc (vm, sa0->crypto_alg,
 377                                (u8 *) vlib_buffer_get_current (i_b0),
 378                                (u8 *) vlib_buffer_get_current (o_b0) +
 379                                ip_udp_hdr_size + sizeof (esp_header_t) +
 380                                IV_SIZE, BLOCK_SIZE * blocks,
 381                                sa0->crypto_key.data, iv);
 382             }
 383
 384           o_b0->current_length +=
 385             hmac_calc (sa0->integ_alg, sa0->integ_key.data,
 386                        sa0->integ_key.len, (u8 *) o_esp0,
 387                        o_b0->current_length - ip_udp_hdr_size,
 388                        vlib_buffer_get_current (o_b0) + o_b0->current_length,
 389                        sa0->use_esn, sa0->seq_hi);
 390
 391
 392           if (is_ip6)
 393             {
 394               oh6_0->ip6.payload_length =
 395                 clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0) -
 396                                       sizeof (ip6_header_t));
 397             }
 398           else
 399             {
 400               oh0->ip4.length =
 401                 clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0));
 402               oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
 403               if (sa0->udp_encap)
 404                 {
 405                   ouh0->udp.length =
 406                     clib_host_to_net_u16 (clib_net_to_host_u16
 407                                           (oh0->ip4.length) -
 408                                           ip4_header_bytes (&oh0->ip4));
 409                 }
 410             }
 411
 412           if (transport_mode)
 413             vlib_buffer_reset (o_b0);
 414
 415         trace:
 416           if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
 417             {
 418               if (o_b0)
 419                 {
 420                   o_b0->flags |= VLIB_BUFFER_IS_TRACED;
 421                   o_b0->trace_index = i_b0->trace_index;
 422                   esp_encrypt_trace_t *tr =
 423                     vlib_add_trace (vm, node, o_b0, sizeof (*tr));
 424                   tr->sa_index = sa_index0;
 425                   tr->spi = sa0->spi;
 426                   tr->seq = sa0->seq - 1;
 427                   tr->udp_encap = sa0->udp_encap;
 428                   tr->crypto_alg = sa0->crypto_alg;
 429                   tr->integ_alg = sa0->integ_alg;
 430                 }
 431             }
 432
 433           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 434                                            to_next, n_left_to_next, o_bi0,
 435                                            next0);
 436         }
 437       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 438     }
 439   vlib_node_increment_counter (vm, node->node_index,
 440                                ESP_ENCRYPT_ERROR_RX_PKTS,
 441                                from_frame->n_vectors);
 442
 443 free_buffers_and_exit:
 444   if (recycle)
 445     vlib_buffer_free (vm, recycle, vec_len (recycle));
 446   vec_free (recycle);
 447   return from_frame->n_vectors;
 448 }
 449
 450 VLIB_NODE_FN (esp4_encrypt_node) (vlib_main_t * vm,
 451                                   vlib_node_runtime_t * node,
 452                                   vlib_frame_t * from_frame)
 453 {
 454   return esp_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
 455 }
 456
 457 /* *INDENT-OFF* */
 458 VLIB_REGISTER_NODE (esp4_encrypt_node) = {
 459   .name = "esp4-encrypt",
 460   .vector_size = sizeof (u32),
 461   .format_trace = format_esp_encrypt_trace,
 462   .type = VLIB_NODE_TYPE_INTERNAL,
 463
 464   .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
 465   .error_strings = esp_encrypt_error_strings,
 466
 467   .n_next_nodes = ESP_ENCRYPT_N_NEXT,
 468   .next_nodes = {
 469 #define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
 470     foreach_esp_encrypt_next
 471 #undef _
 472   },
 473 };
 474 /* *INDENT-ON* */
 475
 476 VLIB_NODE_FN (esp6_encrypt_node) (vlib_main_t * vm,
 477                                   vlib_node_runtime_t * node,
 478                                   vlib_frame_t * from_frame)
 479 {
 480   return esp_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
 481 }
 482
 483 /* *INDENT-OFF* */
 484 VLIB_REGISTER_NODE (esp6_encrypt_node) = {
 485   .name = "esp6-encrypt",
 486   .vector_size = sizeof (u32),
 487   .format_trace = format_esp_encrypt_trace,
 488   .type = VLIB_NODE_TYPE_INTERNAL,
 489
 490   .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
 491   .error_strings = esp_encrypt_error_strings,
 492
 493   .n_next_nodes = ESP_ENCRYPT_N_NEXT,
 494   .next_nodes = {
 495 #define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
 496     foreach_esp_encrypt_next
 497 #undef _
 498   },
 499 };
 500 /* *INDENT-ON* */
 501
 502 /*
 503  * fd.io coding-style-patch-verification: ON
 504  *
 505  * Local Variables:
 506  * eval: (c-set-style "gnu")
 507  * End:
 508  */