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