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 *from = vlib_frame_vector_args (from_frame);
 126   u32 n_left_from = from_frame->n_vectors;
 127   ipsec_main_t *im = &ipsec_main;
 128   ipsec_proto_main_t *em = &ipsec_proto_main;
 129   u32 new_bufs[VLIB_FRAME_SIZE];
 130   vlib_buffer_t *i_bufs[VLIB_FRAME_SIZE], **ib = i_bufs;
 131   vlib_buffer_t *o_bufs[VLIB_FRAME_SIZE], **ob = o_bufs;
 132   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
 133   u32 n_alloc, thread_index = vm->thread_index;
 134
 135   n_alloc = vlib_buffer_alloc (vm, new_bufs, n_left_from);
 136   if (n_alloc != n_left_from)
 137     {
 138       vlib_node_increment_counter (vm, node->node_index,
 139                                    ESP_ENCRYPT_ERROR_NO_BUFFER,
 140                                    n_left_from - n_alloc);
 141       if (n_alloc == 0)
 142         goto done;
 143       n_left_from = n_alloc;
 144     }
 145
 146   vlib_get_buffers (vm, from, ib, n_left_from);
 147   vlib_get_buffers (vm, new_bufs, ob, n_left_from);
 148
 149   while (n_left_from > 0)
 150     {
 151       u32 sa_index0;
 152       ipsec_sa_t *sa0;
 153       ip4_and_esp_header_t *oh0 = 0;
 154       ip6_and_esp_header_t *ih6_0, *oh6_0 = 0;
 155       ip4_and_udp_and_esp_header_t *iuh0, *ouh0 = 0;
 156       esp_header_t *o_esp0;
 157       esp_footer_t *f0;
 158       u8 ip_udp_hdr_size;
 159       u8 next_hdr_type;
 160       u32 ip_proto = 0;
 161       u8 transport_mode = 0;
 162       u32 esp_seq_err;
 163
 164       next[0] = ESP_ENCRYPT_NEXT_DROP;
 165
 166       sa_index0 = vnet_buffer (ib[0])->ipsec.sad_index;
 167       sa0 = pool_elt_at_index (im->sad, sa_index0);
 168
 169       vlib_prefetch_combined_counter (&ipsec_sa_counters, thread_index,
 170                                       sa_index0);
 171
 172       esp_seq_err = esp_seq_advance (sa0);
 173
 174       /* grab free buffer */
 175       ob[0]->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 176       ob[0]->current_data = sizeof (ethernet_header_t);
 177       iuh0 = vlib_buffer_get_current (ib[0]);
 178
 179       if (is_ip6)
 180         {
 181           ih6_0 = vlib_buffer_get_current (ib[0]);
 182           next_hdr_type = IP_PROTOCOL_IPV6;
 183           oh6_0 = vlib_buffer_get_current (ob[0]);
 184
 185           oh6_0->ip6.ip_version_traffic_class_and_flow_label =
 186             ih6_0->ip6.ip_version_traffic_class_and_flow_label;
 187           oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_ESP;
 188           ip_udp_hdr_size = sizeof (ip6_header_t);
 189           o_esp0 = vlib_buffer_get_current (ob[0]) + ip_udp_hdr_size;
 190           oh6_0->ip6.hop_limit = 254;
 191           oh6_0->ip6.src_address.as_u64[0] = ih6_0->ip6.src_address.as_u64[0];
 192           oh6_0->ip6.src_address.as_u64[1] = ih6_0->ip6.src_address.as_u64[1];
 193           oh6_0->ip6.dst_address.as_u64[0] = ih6_0->ip6.dst_address.as_u64[0];
 194           oh6_0->ip6.dst_address.as_u64[1] = ih6_0->ip6.dst_address.as_u64[1];
 195           o_esp0->spi = clib_net_to_host_u32 (sa0->spi);
 196           o_esp0->seq = clib_net_to_host_u32 (sa0->seq);
 197           ip_proto = ih6_0->ip6.protocol;
 198
 199           next[0] = ESP_ENCRYPT_NEXT_IP6_LOOKUP;
 200         }
 201       else
 202         {
 203           next_hdr_type = IP_PROTOCOL_IP_IN_IP;
 204           oh0 = vlib_buffer_get_current (ob[0]);
 205           ouh0 = vlib_buffer_get_current (ob[0]);
 206
 207           oh0->ip4.ip_version_and_header_length = 0x45;
 208           oh0->ip4.tos = iuh0->ip4.tos;
 209           oh0->ip4.fragment_id = 0;
 210           oh0->ip4.flags_and_fragment_offset = 0;
 211           oh0->ip4.ttl = 254;
 212           if (sa0->udp_encap)
 213             {
 214               ouh0->udp.src_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
 215               ouh0->udp.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
 216               ouh0->udp.checksum = 0;
 217               ouh0->ip4.protocol = IP_PROTOCOL_UDP;
 218               ip_udp_hdr_size = sizeof (udp_header_t) + sizeof (ip4_header_t);
 219             }
 220           else
 221             {
 222               oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
 223               ip_udp_hdr_size = sizeof (ip4_header_t);
 224             }
 225           o_esp0 = vlib_buffer_get_current (ob[0]) + ip_udp_hdr_size;
 226           oh0->ip4.src_address.as_u32 = iuh0->ip4.src_address.as_u32;
 227           oh0->ip4.dst_address.as_u32 = iuh0->ip4.dst_address.as_u32;
 228           o_esp0->spi = clib_net_to_host_u32 (sa0->spi);
 229           o_esp0->seq = clib_net_to_host_u32 (sa0->seq);
 230           ip_proto = iuh0->ip4.protocol;
 231
 232           next[0] = ESP_ENCRYPT_NEXT_IP4_LOOKUP;
 233         }
 234
 235       if (PREDICT_TRUE (!is_ip6 && sa0->is_tunnel && !sa0->is_tunnel_ip6))
 236         {
 237           oh0->ip4.src_address.as_u32 = sa0->tunnel_src_addr.ip4.as_u32;
 238           oh0->ip4.dst_address.as_u32 = sa0->tunnel_dst_addr.ip4.as_u32;
 239
 240           next[0] = sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_next_node;
 241           vnet_buffer (ob[0])->ip.adj_index[VLIB_TX] =
 242             sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_index;
 243         }
 244       else if (is_ip6 && sa0->is_tunnel && sa0->is_tunnel_ip6)
 245         {
 246           oh6_0->ip6.src_address.as_u64[0] =
 247             sa0->tunnel_src_addr.ip6.as_u64[0];
 248           oh6_0->ip6.src_address.as_u64[1] =
 249             sa0->tunnel_src_addr.ip6.as_u64[1];
 250           oh6_0->ip6.dst_address.as_u64[0] =
 251             sa0->tunnel_dst_addr.ip6.as_u64[0];
 252           oh6_0->ip6.dst_address.as_u64[1] =
 253             sa0->tunnel_dst_addr.ip6.as_u64[1];
 254
 255           next[0] = sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_next_node;
 256           vnet_buffer (ob[0])->ip.adj_index[VLIB_TX] =
 257             sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_index;
 258         }
 259       else
 260         {
 261           next_hdr_type = ip_proto;
 262           if (vnet_buffer (ib[0])->sw_if_index[VLIB_TX] != ~0)
 263             {
 264               transport_mode = 1;
 265               ethernet_header_t *ieh0, *oeh0;
 266               ieh0 =
 267                 (ethernet_header_t *) ((u8 *)
 268                                        vlib_buffer_get_current (ib[0]) -
 269                                        sizeof (ethernet_header_t));
 270               oeh0 = (ethernet_header_t *) ob[0]->data;
 271               clib_memcpy_fast (oeh0, ieh0, sizeof (ethernet_header_t));
 272               next[0] = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
 273               vnet_buffer (ob[0])->sw_if_index[VLIB_TX] =
 274                 vnet_buffer (ib[0])->sw_if_index[VLIB_TX];
 275             }
 276
 277           if (is_ip6)
 278             vlib_buffer_advance (ib[0], sizeof (ip6_header_t));
 279           else
 280             vlib_buffer_advance (ib[0], sizeof (ip4_header_t));
 281         }
 282
 283       ASSERT (sa0->crypto_alg < IPSEC_CRYPTO_N_ALG);
 284       vlib_increment_combined_counter
 285         (&ipsec_sa_counters, thread_index, sa_index0,
 286          1, ib[0]->current_length);
 287
 288       if (PREDICT_TRUE (sa0->crypto_alg != IPSEC_CRYPTO_ALG_NONE))
 289         {
 290
 291           const int BLOCK_SIZE =
 292             em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].block_size;
 293           const int IV_SIZE =
 294             em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size;
 295           int blocks = 1 + (ib[0]->current_length + 1) / BLOCK_SIZE;
 296
 297           /* pad packet in input buffer */
 298           u8 pad_bytes = BLOCK_SIZE * blocks - 2 - ib[0]->current_length;
 299           u8 i;
 300           u8 *padding =
 301             vlib_buffer_get_current (ib[0]) + ib[0]->current_length;
 302           ib[0]->current_length = BLOCK_SIZE * blocks;
 303           for (i = 0; i < pad_bytes; ++i)
 304             {
 305               padding[i] = i + 1;
 306             }
 307           f0 = vlib_buffer_get_current (ib[0]) + ib[0]->current_length - 2;
 308           f0->pad_length = pad_bytes;
 309           f0->next_header = next_hdr_type;
 310
 311           ob[0]->current_length = ip_udp_hdr_size + sizeof (esp_header_t) +
 312             BLOCK_SIZE * blocks + IV_SIZE;
 313
 314           vnet_buffer (ob[0])->sw_if_index[VLIB_RX] =
 315             vnet_buffer (ib[0])->sw_if_index[VLIB_RX];
 316
 317           u8 iv[em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size];
 318           RAND_bytes (iv, sizeof (iv));
 319
 320           clib_memcpy_fast ((u8 *) vlib_buffer_get_current (ob[0]) +
 321                             ip_udp_hdr_size + sizeof (esp_header_t), iv,
 322                             em->ipsec_proto_main_crypto_algs[sa0->
 323                                                              crypto_alg].iv_size);
 324
 325           esp_encrypt_cbc (vm, sa0->crypto_alg,
 326                            (u8 *) vlib_buffer_get_current (ib[0]),
 327                            (u8 *) vlib_buffer_get_current (ob[0]) +
 328                            ip_udp_hdr_size + sizeof (esp_header_t) +
 329                            IV_SIZE, BLOCK_SIZE * blocks,
 330                            sa0->crypto_key.data, iv);
 331         }
 332
 333       ob[0]->current_length +=
 334         hmac_calc (sa0->integ_alg, sa0->integ_key.data,
 335                    sa0->integ_key.len, (u8 *) o_esp0,
 336                    ob[0]->current_length - ip_udp_hdr_size,
 337                    vlib_buffer_get_current (ob[0]) + ob[0]->current_length,
 338                    sa0->use_esn, sa0->seq_hi);
 339
 340
 341       if (is_ip6)
 342         {
 343           oh6_0->ip6.payload_length =
 344             clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, ob[0]) -
 345                                   sizeof (ip6_header_t));
 346         }
 347       else
 348         {
 349           oh0->ip4.length =
 350             clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, ob[0]));
 351           oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
 352           if (sa0->udp_encap)
 353             {
 354               ouh0->udp.length =
 355                 clib_host_to_net_u16 (clib_net_to_host_u16
 356                                       (oh0->ip4.length) -
 357                                       ip4_header_bytes (&oh0->ip4));
 358             }
 359         }
 360
 361       if (transport_mode)
 362         vlib_buffer_reset (ob[0]);
 363
 364       if (PREDICT_FALSE (esp_seq_err))
 365         {
 366           ob[0]->error = node->errors[ESP_ENCRYPT_ERROR_SEQ_CYCLED];
 367           next[0] = ESP_ENCRYPT_NEXT_DROP;
 368         }
 369
 370       if (PREDICT_FALSE (ib[0]->flags & VLIB_BUFFER_IS_TRACED))
 371         {
 372           if (ob[0])
 373             {
 374               ob[0]->flags |= VLIB_BUFFER_IS_TRACED;
 375               ob[0]->trace_index = ib[0]->trace_index;
 376               esp_encrypt_trace_t *tr =
 377                 vlib_add_trace (vm, node, ob[0], sizeof (*tr));
 378               tr->sa_index = sa_index0;
 379               tr->spi = sa0->spi;
 380               tr->seq = sa0->seq - 1;
 381               tr->udp_encap = sa0->udp_encap;
 382               tr->crypto_alg = sa0->crypto_alg;
 383               tr->integ_alg = sa0->integ_alg;
 384             }
 385         }
 386
 387       /* next */
 388       n_left_from -= 1;
 389       ib += 1;
 390       ob += 1;
 391       next += 1;
 392     }
 393
 394   vlib_node_increment_counter (vm, node->node_index,
 395                                ESP_ENCRYPT_ERROR_RX_PKTS, n_alloc);
 396
 397   vlib_buffer_enqueue_to_next (vm, node, new_bufs, nexts, n_alloc);
 398 done:
 399   vlib_buffer_free (vm, from, from_frame->n_vectors);
 400   return n_alloc;
 401 }
 402
 403 VLIB_NODE_FN (esp4_encrypt_node) (vlib_main_t * vm,
 404                                   vlib_node_runtime_t * node,
 405                                   vlib_frame_t * from_frame)
 406 {
 407   return esp_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
 408 }
 409
 410 /* *INDENT-OFF* */
 411 VLIB_REGISTER_NODE (esp4_encrypt_node) = {
 412   .name = "esp4-encrypt",
 413   .vector_size = sizeof (u32),
 414   .format_trace = format_esp_encrypt_trace,
 415   .type = VLIB_NODE_TYPE_INTERNAL,
 416
 417   .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
 418   .error_strings = esp_encrypt_error_strings,
 419
 420   .n_next_nodes = ESP_ENCRYPT_N_NEXT,
 421   .next_nodes = {
 422 #define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
 423     foreach_esp_encrypt_next
 424 #undef _
 425   },
 426 };
 427 /* *INDENT-ON* */
 428
 429 VLIB_NODE_FN (esp6_encrypt_node) (vlib_main_t * vm,
 430                                   vlib_node_runtime_t * node,
 431                                   vlib_frame_t * from_frame)
 432 {
 433   return esp_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
 434 }
 435
 436 /* *INDENT-OFF* */
 437 VLIB_REGISTER_NODE (esp6_encrypt_node) = {
 438   .name = "esp6-encrypt",
 439   .vector_size = sizeof (u32),
 440   .format_trace = format_esp_encrypt_trace,
 441   .type = VLIB_NODE_TYPE_INTERNAL,
 442
 443   .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
 444   .error_strings = esp_encrypt_error_strings,
 445
 446   .n_next_nodes = ESP_ENCRYPT_N_NEXT,
 447   .next_nodes = {
 448 #define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
 449     foreach_esp_encrypt_next
 450 #undef _
 451   },
 452 };
 453 /* *INDENT-ON* */
 454
 455 /*
 456  * fd.io coding-style-patch-verification: ON
 457  *
 458  * Local Variables:
 459  * eval: (c-set-style "gnu")
 460  * End:
 461  */