src/vnet/ipsec/ipsec_tun_in.c

   1 /*
   2  * ipsec_tun_protect_in.c : IPSec interface input 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
  22 #include <vnet/ipsec/ipsec.h>
  23 #include <vnet/ipsec/esp.h>
  24 #include <vnet/ipsec/ipsec_io.h>
  25 #include <vnet/ipsec/ipsec_punt.h>
  26 #include <vnet/ipsec/ipsec_tun.h>
  27 #include <vnet/ip/ip4_input.h>
  28
  29 /* Statistics (not really errors) */
  30 #define foreach_ipsec_tun_protect_input_error                     \
  31   _(RX, "good packets received")                                  \
  32   _(DISABLED, "ipsec packets received on disabled interface")     \
  33   _(NO_TUNNEL, "no matching tunnel")                              \
  34   _(TUNNEL_MISMATCH, "SPI-tunnel mismatch")                       \
  35   _(NAT_KEEPALIVE, "NAT Keepalive")                               \
  36   _(TOO_SHORT, "Too Short")                                       \
  37   _(SPI_0, "SPI 0")
  38
  39 static char *ipsec_tun_protect_input_error_strings[] = {
  40 #define _(sym,string) string,
  41   foreach_ipsec_tun_protect_input_error
  42 #undef _
  43 };
  44
  45 typedef enum
  46 {
  47 #define _(sym,str) IPSEC_TUN_PROTECT_INPUT_ERROR_##sym,
  48   foreach_ipsec_tun_protect_input_error
  49 #undef _
  50     IPSEC_TUN_PROTECT_INPUT_N_ERROR,
  51 } ipsec_tun_protect_input_error_t;
  52
  53 typedef enum ipsec_tun_next_t_
  54 {
  55 #define _(v, s) IPSEC_TUN_PROTECT_NEXT_##v,
  56   foreach_ipsec_input_next
  57 #undef _
  58     IPSEC_TUN_PROTECT_N_NEXT,
  59 } ipsec_tun_next_t;
  60
  61 typedef struct
  62 {
  63   union
  64   {
  65     ipsec4_tunnel_kv_t kv4;
  66     ipsec6_tunnel_kv_t kv6;
  67   };
  68   u8 is_ip6;
  69   u32 seq;
  70 } ipsec_tun_protect_input_trace_t;
  71
  72 static u8 *
  73 format_ipsec_tun_protect_input_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   ipsec_tun_protect_input_trace_t *t =
  78     va_arg (*args, ipsec_tun_protect_input_trace_t *);
  79
  80   if (t->is_ip6)
  81     s = format (s, "IPSec: %U seq %u",
  82                 format_ipsec6_tunnel_kv, &t->kv6, t->seq);
  83   else
  84     s = format (s, "IPSec: %U seq %u sa %d",
  85                 format_ipsec4_tunnel_kv, &t->kv4, t->seq);
  86   return s;
  87 }
  88
  89 always_inline u16
  90 ipsec_ip4_if_no_tunnel (vlib_node_runtime_t * node,
  91                         vlib_buffer_t * b,
  92                         const esp_header_t * esp, const ip4_header_t * ip4)
  93 {
  94   if (PREDICT_FALSE (0 == esp->spi))
  95     {
  96       b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_SPI_0];
  97       b->punt_reason = ipsec_punt_reason[(ip4->protocol == IP_PROTOCOL_UDP ?
  98                                           IPSEC_PUNT_IP4_SPI_UDP_0 :
  99                                           IPSEC_PUNT_IP4_NO_SUCH_TUNNEL)];
 100     }
 101   else
 102     {
 103       b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL];
 104       b->punt_reason = ipsec_punt_reason[IPSEC_PUNT_IP4_NO_SUCH_TUNNEL];
 105     }
 106   return IPSEC_INPUT_NEXT_PUNT;
 107 }
 108
 109 always_inline u16
 110 ipsec_ip6_if_no_tunnel (vlib_node_runtime_t * node,
 111                         vlib_buffer_t * b, const esp_header_t * esp)
 112 {
 113   b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL];
 114   b->punt_reason = ipsec_punt_reason[IPSEC_PUNT_IP6_NO_SUCH_TUNNEL];
 115
 116   return (IPSEC_INPUT_NEXT_PUNT);
 117 }
 118
 119 always_inline uword
 120 ipsec_tun_protect_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 121                                 vlib_frame_t * from_frame, int is_ip6)
 122 {
 123   ipsec_main_t *im = &ipsec_main;
 124   vnet_main_t *vnm = im->vnet_main;
 125   vnet_interface_main_t *vim = &vnm->interface_main;
 126
 127   int is_trace = node->flags & VLIB_NODE_FLAG_TRACE;
 128   u32 thread_index = vm->thread_index;
 129
 130   u32 n_left_from, *from;
 131   u16 nexts[VLIB_FRAME_SIZE], *next;
 132   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
 133
 134   from = vlib_frame_vector_args (from_frame);
 135   n_left_from = from_frame->n_vectors;
 136
 137   vlib_get_buffers (vm, from, bufs, n_left_from);
 138   b = bufs;
 139   next = nexts;
 140
 141   clib_memset_u16 (nexts, im->esp4_decrypt_next_index, n_left_from);
 142
 143   u64 n_bytes = 0, n_packets = 0;
 144   u32 n_disabled = 0, n_no_tunnel = 0;
 145
 146   u32 last_sw_if_index = ~0;
 147   ipsec_tun_lkup_result_t last_result = {
 148     .tun_index = ~0
 149   };
 150   ipsec4_tunnel_kv_t last_key4;
 151   ipsec6_tunnel_kv_t last_key6;
 152   ipsec_tun_lkup_result_t itr0;
 153
 154   vlib_combined_counter_main_t *rx_counter;
 155   vlib_combined_counter_main_t *drop_counter;
 156
 157   if (is_ip6)
 158     clib_memset (&last_key6, 0xff, sizeof (last_key6));
 159   else
 160     last_key4.key = ~0;
 161
 162   rx_counter = vim->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX;
 163   drop_counter = vim->combined_sw_if_counters + VNET_INTERFACE_COUNTER_DROP;
 164
 165   while (n_left_from > 0)
 166     {
 167       u32 sw_if_index0, len0, hdr_sz0;
 168       clib_bihash_kv_24_16_t bkey60;
 169       clib_bihash_kv_8_16_t bkey40;
 170       ipsec4_tunnel_kv_t *key40;
 171       ipsec6_tunnel_kv_t *key60;
 172       ip4_header_t *ip40;
 173       ip6_header_t *ip60;
 174       esp_header_t *esp0;
 175       u16 buf_rewind0;
 176
 177       ip40 =
 178         (ip4_header_t *) (b[0]->data + vnet_buffer (b[0])->l3_hdr_offset);
 179
 180       key60 = (ipsec6_tunnel_kv_t *) & bkey60;
 181       key40 = (ipsec4_tunnel_kv_t *) & bkey40;
 182
 183       if (is_ip6)
 184         {
 185           ip60 = (ip6_header_t *) ip40;
 186           esp0 = (esp_header_t *) (ip60 + 1);
 187           hdr_sz0 = sizeof (ip6_header_t);
 188         }
 189       else
 190         {
 191           /* NAT UDP port 4500 case, don't advance any more */
 192           if (ip40->protocol == IP_PROTOCOL_UDP)
 193             {
 194               esp0 =
 195                 (esp_header_t *) ((u8 *) ip40 + ip4_header_bytes (ip40) +
 196                                   sizeof (udp_header_t));
 197               hdr_sz0 = 0;
 198               buf_rewind0 = ip4_header_bytes (ip40) + sizeof (udp_header_t);
 199             }
 200           else
 201             {
 202               esp0 = (esp_header_t *) ((u8 *) ip40 + ip4_header_bytes (ip40));
 203               buf_rewind0 = hdr_sz0 = ip4_header_bytes (ip40);
 204             }
 205         }
 206
 207       /* stats for the tunnel include all the data after the IP header
 208          just like a norml IP-IP tunnel */
 209       vlib_buffer_advance (b[0], hdr_sz0);
 210       len0 = vlib_buffer_length_in_chain (vm, b[0]);
 211
 212       if (len0 < sizeof (esp_header_t))
 213         {
 214           if (esp0->spi_bytes[0] == 0xff)
 215             b[0]->error =
 216               node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NAT_KEEPALIVE];
 217           else
 218             b[0]->error =
 219               node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_TOO_SHORT];
 220
 221           next[0] = IPSEC_INPUT_NEXT_DROP;
 222           goto trace00;
 223         }
 224
 225       if (is_ip6)
 226         {
 227           key60->key.remote_ip = ip60->src_address;
 228           key60->key.spi = esp0->spi;
 229           key60->key.__pad = 0;
 230
 231           if (memcmp (key60, &last_key6, sizeof (last_key6)) == 0)
 232             {
 233               clib_memcpy_fast (&itr0, &last_result, sizeof (itr0));
 234             }
 235           else
 236             {
 237               int rv =
 238                 clib_bihash_search_inline_24_16 (&im->tun6_protect_by_key,
 239                                                  &bkey60);
 240               if (!rv)
 241                 {
 242                   clib_memcpy_fast (&itr0, &bkey60.value, sizeof (itr0));
 243                   clib_memcpy_fast (&last_result, &bkey60.value,
 244                                     sizeof (last_result));
 245                   clib_memcpy_fast (&last_key6, key60, sizeof (last_key6));
 246                 }
 247               else
 248                 {
 249                   next[0] = ipsec_ip6_if_no_tunnel (node, b[0], esp0);
 250                   n_no_tunnel++;
 251                   goto trace00;
 252                 }
 253             }
 254         }
 255       else
 256         {
 257           ipsec4_tunnel_mk_key (key40, &ip40->src_address, esp0->spi);
 258
 259           if (key40->key == last_key4.key)
 260             {
 261               clib_memcpy_fast (&itr0, &last_result, sizeof (itr0));
 262             }
 263           else
 264             {
 265               int rv =
 266                 clib_bihash_search_inline_8_16 (&im->tun4_protect_by_key,
 267                                                 &bkey40);
 268               if (!rv)
 269                 {
 270                   clib_memcpy_fast (&itr0, &bkey40.value, sizeof (itr0));
 271                   clib_memcpy_fast (&last_result, &bkey40.value,
 272                                     sizeof (last_result));
 273                   last_key4.key = key40->key;
 274                 }
 275               else
 276                 {
 277                   next[0] = ipsec_ip4_if_no_tunnel (node, b[0], esp0, ip40);
 278                   vlib_buffer_advance (b[0], -buf_rewind0);
 279                   n_no_tunnel++;
 280                   goto trace00;
 281                 }
 282             }
 283         }
 284
 285       vnet_buffer (b[0])->ipsec.sad_index = itr0.sa_index;
 286       vnet_buffer (b[0])->ipsec.protect_index = itr0.tun_index;
 287
 288       sw_if_index0 = itr0.sw_if_index;
 289       vnet_buffer (b[0])->sw_if_index[VLIB_RX] = sw_if_index0;
 290
 291       if (PREDICT_FALSE (!vnet_sw_interface_is_admin_up (vnm, sw_if_index0)))
 292         {
 293           vlib_increment_combined_counter
 294             (drop_counter, thread_index, sw_if_index0, 1, len0);
 295           n_disabled++;
 296           b[0]->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_DISABLED];
 297           next[0] = IPSEC_INPUT_NEXT_DROP;
 298           goto trace00;
 299         }
 300       else
 301         {
 302           if (PREDICT_TRUE (sw_if_index0 == last_sw_if_index))
 303             {
 304               n_packets++;
 305               n_bytes += len0;
 306             }
 307           else
 308             {
 309               if (n_packets && !(itr0.flags & IPSEC_PROTECT_ENCAPED))
 310                 {
 311                   vlib_increment_combined_counter
 312                     (rx_counter, thread_index, last_sw_if_index,
 313                      n_packets, n_bytes);
 314                 }
 315
 316               last_sw_if_index = sw_if_index0;
 317               n_packets = 1;
 318               n_bytes = len0;
 319             }
 320
 321           //IPSEC_TUN_PROTECT_NEXT_DECRYPT;
 322           next[0] = im->esp4_decrypt_tun_next_index;
 323         }
 324     trace00:
 325       if (PREDICT_FALSE (is_trace))
 326         {
 327           if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
 328             {
 329               ipsec_tun_protect_input_trace_t *tr =
 330                 vlib_add_trace (vm, node, b[0], sizeof (*tr));
 331               if (is_ip6)
 332                 clib_memcpy (&tr->kv6, &bkey60, sizeof (tr->kv6));
 333               else
 334                 clib_memcpy (&tr->kv4, &bkey40, sizeof (tr->kv4));
 335               tr->is_ip6 = is_ip6;
 336               tr->seq = (len0 >= sizeof (*esp0) ?
 337                          clib_host_to_net_u32 (esp0->seq) : ~0);
 338             }
 339         }
 340
 341       /* next */
 342       b += 1;
 343       next += 1;
 344       n_left_from -= 1;
 345     }
 346
 347   if (n_packets && !(itr0.flags & IPSEC_PROTECT_ENCAPED))
 348     vlib_increment_combined_counter (rx_counter,
 349                                      thread_index,
 350                                      last_sw_if_index, n_packets, n_bytes);
 351
 352   vlib_node_increment_counter (vm, node->node_index,
 353                                IPSEC_TUN_PROTECT_INPUT_ERROR_RX,
 354                                from_frame->n_vectors - (n_disabled +
 355                                                         n_no_tunnel));
 356   vlib_node_increment_counter (vm, node->node_index,
 357                                IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL,
 358                                n_no_tunnel);
 359
 360   vlib_buffer_enqueue_to_next (vm, node, from, nexts, from_frame->n_vectors);
 361
 362   return from_frame->n_vectors;
 363 }
 364
 365 VLIB_NODE_FN (ipsec4_tun_input_node) (vlib_main_t * vm,
 366                                       vlib_node_runtime_t * node,
 367                                       vlib_frame_t * from_frame)
 368 {
 369   return ipsec_tun_protect_input_inline (vm, node, from_frame, 0);
 370 }
 371
 372 /* *INDENT-OFF* */
 373 VLIB_REGISTER_NODE (ipsec4_tun_input_node) = {
 374   .name = "ipsec4-tun-input",
 375   .vector_size = sizeof (u32),
 376   .format_trace = format_ipsec_tun_protect_input_trace,
 377   .type = VLIB_NODE_TYPE_INTERNAL,
 378   .n_errors = ARRAY_LEN(ipsec_tun_protect_input_error_strings),
 379   .error_strings = ipsec_tun_protect_input_error_strings,
 380   .n_next_nodes = IPSEC_TUN_PROTECT_N_NEXT,
 381   .next_nodes = {
 382     [IPSEC_TUN_PROTECT_NEXT_DROP] = "ip4-drop",
 383     [IPSEC_TUN_PROTECT_NEXT_PUNT] = "punt-dispatch",
 384   }
 385 };
 386 /* *INDENT-ON* */
 387
 388 VLIB_NODE_FN (ipsec6_tun_input_node) (vlib_main_t * vm,
 389                                       vlib_node_runtime_t * node,
 390                                       vlib_frame_t * from_frame)
 391 {
 392   return ipsec_tun_protect_input_inline (vm, node, from_frame, 1);
 393 }
 394
 395 /* *INDENT-OFF* */
 396 VLIB_REGISTER_NODE (ipsec6_tun_input_node) = {
 397   .name = "ipsec6-tun-input",
 398   .vector_size = sizeof (u32),
 399   .format_trace = format_ipsec_tun_protect_input_trace,
 400   .type = VLIB_NODE_TYPE_INTERNAL,
 401   .n_errors = ARRAY_LEN(ipsec_tun_protect_input_error_strings),
 402   .error_strings = ipsec_tun_protect_input_error_strings,
 403   .n_next_nodes = IPSEC_TUN_PROTECT_N_NEXT,
 404   .next_nodes = {
 405     [IPSEC_TUN_PROTECT_NEXT_DROP] = "ip6-drop",
 406     [IPSEC_TUN_PROTECT_NEXT_PUNT] = "punt-dispatch",
 407   }
 408 };
 409 /* *INDENT-ON* */
 410
 411 /*
 412  * fd.io coding-style-patch-verification: ON
 413  *
 414  * Local Variables:
 415  * eval: (c-set-style "gnu")
 416  * End:
 417  */