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