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_key_t key4;
  66     ipsec6_tunnel_key_t key6;
  67   };
  68   u8 is_ip6;
  69   u32 seq;
  70   u32 sa_index;
  71 } ipsec_tun_protect_input_trace_t;
  72
  73 static u8 *
  74 format_ipsec_tun_protect_input_trace (u8 * s, va_list * args)
  75 {
  76   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  77   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  78   ipsec_tun_protect_input_trace_t *t =
  79     va_arg (*args, ipsec_tun_protect_input_trace_t *);
  80
  81   if (t->is_ip6)
  82     s = format (s, "IPSec: %U seq %u sa %d",
  83                 format_ipsec6_tunnel_key, &t->key6, t->seq, t->sa_index);
  84   else
  85     s = format (s, "IPSec: %U seq %u sa %d",
  86                 format_ipsec4_tunnel_key, &t->key4, t->seq, t->sa_index);
  87   return s;
  88 }
  89
  90 always_inline u16
  91 ipsec_ip4_if_no_tunnel (vlib_node_runtime_t * node,
  92                         vlib_buffer_t * b,
  93                         const esp_header_t * esp, const ip4_header_t * ip4)
  94 {
  95   if (PREDICT_FALSE (0 == esp->spi))
  96     {
  97       b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_SPI_0];
  98       b->punt_reason = ipsec_punt_reason[(ip4->protocol == IP_PROTOCOL_UDP ?
  99                                           IPSEC_PUNT_IP4_SPI_UDP_0 :
 100                                           IPSEC_PUNT_IP4_NO_SUCH_TUNNEL)];
 101     }
 102   else
 103     {
 104       b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL];
 105       b->punt_reason = ipsec_punt_reason[IPSEC_PUNT_IP4_NO_SUCH_TUNNEL];
 106     }
 107   return IPSEC_INPUT_NEXT_PUNT;
 108 }
 109
 110 always_inline u16
 111 ipsec_ip6_if_no_tunnel (vlib_node_runtime_t * node,
 112                         vlib_buffer_t * b, const esp_header_t * esp)
 113 {
 114   b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL];
 115   b->punt_reason = ipsec_punt_reason[IPSEC_PUNT_IP6_NO_SUCH_TUNNEL];
 116
 117   return (IPSEC_INPUT_NEXT_PUNT);
 118 }
 119
 120 always_inline uword
 121 ipsec_tun_protect_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 122                                 vlib_frame_t * from_frame, int is_ip6)
 123 {
 124   ipsec_main_t *im = &ipsec_main;
 125   vnet_main_t *vnm = im->vnet_main;
 126   vnet_interface_main_t *vim = &vnm->interface_main;
 127
 128   int is_trace = node->flags & VLIB_NODE_FLAG_TRACE;
 129   u32 thread_index = vm->thread_index;
 130
 131   u32 n_left_from, *from;
 132   u16 nexts[VLIB_FRAME_SIZE], *next;
 133   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
 134
 135   from = vlib_frame_vector_args (from_frame);
 136   n_left_from = from_frame->n_vectors;
 137
 138   vlib_get_buffers (vm, from, bufs, n_left_from);
 139   b = bufs;
 140   next = nexts;
 141
 142   clib_memset_u16 (nexts, im->esp4_decrypt_next_index, n_left_from);
 143
 144   u64 n_bytes = 0, n_packets = 0;
 145   u32 n_disabled = 0, n_no_tunnel = 0;
 146
 147   u32 last_sw_if_index = ~0;
 148   ipsec_tun_lkup_result_t last_result = {
 149     .tun_index = ~0
 150   };
 151   ipsec4_tunnel_key_t last_key4;
 152   ipsec6_tunnel_key_t last_key6;
 153
 154   vlib_combined_counter_main_t *rx_counter;
 155   vlib_combined_counter_main_t *drop_counter;
 156   ipsec_tun_protect_t *itp0;
 157
 158   if (is_ip6)
 159     clib_memset (&last_key6, 0xff, sizeof (last_key6));
 160   else
 161     last_key4.as_u64 = ~0;
 162
 163   rx_counter = vim->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX;
 164   drop_counter = vim->combined_sw_if_counters + VNET_INTERFACE_COUNTER_DROP;
 165
 166   while (n_left_from > 0)
 167     {
 168       u32 sw_if_index0, len0, hdr_sz0;
 169       ipsec_tun_lkup_result_t itr0;
 170       ipsec4_tunnel_key_t key40;
 171       ipsec6_tunnel_key_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       if (is_ip6)
 181         {
 182           ip60 = (ip6_header_t *) ip40;
 183           esp0 = (esp_header_t *) (ip60 + 1);
 184           hdr_sz0 = sizeof (ip6_header_t);
 185         }
 186       else
 187         {
 188           /* NAT UDP port 4500 case, don't advance any more */
 189           if (ip40->protocol == IP_PROTOCOL_UDP)
 190             {
 191               esp0 =
 192                 (esp_header_t *) ((u8 *) ip40 + ip4_header_bytes (ip40) +
 193                                   sizeof (udp_header_t));
 194               hdr_sz0 = 0;
 195               buf_rewind0 = ip4_header_bytes (ip40) + sizeof (udp_header_t);
 196             }
 197           else
 198             {
 199               esp0 = (esp_header_t *) ((u8 *) ip40 + ip4_header_bytes (ip40));
 200               buf_rewind0 = hdr_sz0 = ip4_header_bytes (ip40);
 201             }
 202         }
 203
 204       /* stats for the tunnel include all the data after the IP header
 205          just like a norml IP-IP tunnel */
 206       vlib_buffer_advance (b[0], hdr_sz0);
 207       len0 = vlib_buffer_length_in_chain (vm, b[0]);
 208
 209       if (len0 < sizeof (esp_header_t))
 210         {
 211           if (esp0->spi_bytes[0] == 0xff)
 212             b[0]->error =
 213               node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NAT_KEEPALIVE];
 214           else
 215             b[0]->error =
 216               node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_TOO_SHORT];
 217
 218           next[0] = IPSEC_INPUT_NEXT_DROP;
 219           goto trace00;
 220         }
 221
 222       if (is_ip6)
 223         {
 224           key60.remote_ip = ip60->src_address;
 225           key60.spi = esp0->spi;
 226
 227           if (memcmp (&key60, &last_key6, sizeof (last_key6)) == 0)
 228             {
 229               itr0 = last_result;
 230             }
 231           else
 232             {
 233               uword *p = hash_get_mem (im->tun6_protect_by_key, &key60);
 234               if (p)
 235                 {
 236                   itr0.as_u64 = p[0];
 237                   last_result = itr0;
 238                   clib_memcpy_fast (&last_key6, &key60, sizeof (key60));
 239                 }
 240               else
 241                 {
 242                   next[0] = ipsec_ip6_if_no_tunnel (node, b[0], esp0);
 243                   n_no_tunnel++;
 244                   goto trace00;
 245                 }
 246             }
 247         }
 248       else
 249         {
 250           key40.remote_ip = ip40->src_address;
 251           key40.spi = esp0->spi;
 252
 253           if (key40.as_u64 == last_key4.as_u64)
 254             {
 255               itr0 = last_result;
 256             }
 257           else
 258             {
 259               uword *p = hash_get (im->tun4_protect_by_key, key40.as_u64);
 260               if (p)
 261                 {
 262                   itr0.as_u64 = p[0];
 263                   last_result = itr0;
 264                   last_key4.as_u64 = key40.as_u64;
 265                 }
 266               else
 267                 {
 268                   next[0] = ipsec_ip4_if_no_tunnel (node, b[0], esp0, ip40);
 269                   vlib_buffer_advance (b[0], -buf_rewind0);
 270                   n_no_tunnel++;
 271                   goto trace00;
 272                 }
 273             }
 274         }
 275
 276       itp0 = pool_elt_at_index (ipsec_tun_protect_pool, itr0.tun_index);
 277       vnet_buffer (b[0])->ipsec.sad_index = itr0.sa_index;
 278       vnet_buffer (b[0])->ipsec.protect_index = itr0.tun_index;
 279
 280       sw_if_index0 = itp0->itp_sw_if_index;
 281       vnet_buffer (b[0])->sw_if_index[VLIB_RX] = sw_if_index0;
 282
 283       if (PREDICT_FALSE (!vnet_sw_interface_is_admin_up (vnm, sw_if_index0)))
 284         {
 285           vlib_increment_combined_counter
 286             (drop_counter, thread_index, sw_if_index0, 1, len0);
 287           n_disabled++;
 288           b[0]->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_DISABLED];
 289           next[0] = IPSEC_INPUT_NEXT_DROP;
 290           goto trace00;
 291         }
 292       else
 293         {
 294           if (PREDICT_TRUE (sw_if_index0 == last_sw_if_index))
 295             {
 296               n_packets++;
 297               n_bytes += len0;
 298             }
 299           else
 300             {
 301               if (n_packets && !(itp0->itp_flags & IPSEC_PROTECT_ENCAPED))
 302                 {
 303                   vlib_increment_combined_counter
 304                     (rx_counter, thread_index, last_sw_if_index,
 305                      n_packets, n_bytes);
 306                 }
 307
 308               last_sw_if_index = sw_if_index0;
 309               n_packets = 1;
 310               n_bytes = len0;
 311             }
 312
 313           next[0] = im->esp4_decrypt_tun_next_index;    //IPSEC_TUN_PROTECT_NEXT_DECRYPT;
 314         }
 315     trace00:
 316       if (PREDICT_FALSE (is_trace))
 317         {
 318           if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
 319             {
 320               ipsec_tun_protect_input_trace_t *tr =
 321                 vlib_add_trace (vm, node, b[0], sizeof (*tr));
 322               if (is_ip6)
 323                 clib_memcpy (&tr->key6, &key60, sizeof (tr->key6));
 324               else
 325                 clib_memcpy (&tr->key4, &key40, sizeof (tr->key4));
 326               tr->is_ip6 = is_ip6;
 327               tr->seq = (len0 >= sizeof (*esp0) ?
 328                          clib_host_to_net_u32 (esp0->seq) : ~0);
 329               tr->sa_index = vnet_buffer (b[0])->ipsec.sad_index;
 330             }
 331         }
 332
 333       /* next */
 334       b += 1;
 335       next += 1;
 336       n_left_from -= 1;
 337     }
 338
 339   if (n_packets && !(itp0->itp_flags & IPSEC_PROTECT_ENCAPED))
 340     {
 341       vlib_increment_combined_counter (rx_counter,
 342                                        thread_index,
 343                                        last_sw_if_index, n_packets, n_bytes);
 344     }
 345
 346   vlib_node_increment_counter (vm, node->node_index,
 347                                IPSEC_TUN_PROTECT_INPUT_ERROR_RX,
 348                                from_frame->n_vectors - (n_disabled +
 349                                                         n_no_tunnel));
 350
 351   vlib_buffer_enqueue_to_next (vm, node, from, nexts, from_frame->n_vectors);
 352
 353   return from_frame->n_vectors;
 354 }
 355
 356 VLIB_NODE_FN (ipsec4_tun_input_node) (vlib_main_t * vm,
 357                                       vlib_node_runtime_t * node,
 358                                       vlib_frame_t * from_frame)
 359 {
 360   return ipsec_tun_protect_input_inline (vm, node, from_frame, 0);
 361 }
 362
 363 /* *INDENT-OFF* */
 364 VLIB_REGISTER_NODE (ipsec4_tun_input_node) = {
 365   .name = "ipsec4-tun-input",
 366   .vector_size = sizeof (u32),
 367   .format_trace = format_ipsec_tun_protect_input_trace,
 368   .type = VLIB_NODE_TYPE_INTERNAL,
 369   .n_errors = ARRAY_LEN(ipsec_tun_protect_input_error_strings),
 370   .error_strings = ipsec_tun_protect_input_error_strings,
 371   .n_next_nodes = IPSEC_TUN_PROTECT_N_NEXT,
 372   .next_nodes = {
 373     [IPSEC_TUN_PROTECT_NEXT_DROP] = "ip4-drop",
 374     [IPSEC_TUN_PROTECT_NEXT_PUNT] = "punt-dispatch",
 375   }
 376 };
 377 /* *INDENT-ON* */
 378
 379 VLIB_NODE_FN (ipsec6_tun_input_node) (vlib_main_t * vm,
 380                                       vlib_node_runtime_t * node,
 381                                       vlib_frame_t * from_frame)
 382 {
 383   return ipsec_tun_protect_input_inline (vm, node, from_frame, 1);
 384 }
 385
 386 /* *INDENT-OFF* */
 387 VLIB_REGISTER_NODE (ipsec6_tun_input_node) = {
 388   .name = "ipsec6-tun-input",
 389   .vector_size = sizeof (u32),
 390   .format_trace = format_ipsec_tun_protect_input_trace,
 391   .type = VLIB_NODE_TYPE_INTERNAL,
 392   .n_errors = ARRAY_LEN(ipsec_tun_protect_input_error_strings),
 393   .error_strings = ipsec_tun_protect_input_error_strings,
 394   .n_next_nodes = IPSEC_TUN_PROTECT_N_NEXT,
 395   .next_nodes = {
 396     [IPSEC_TUN_PROTECT_NEXT_DROP] = "ip6-drop",
 397     [IPSEC_TUN_PROTECT_NEXT_PUNT] = "punt-dispatch",
 398   }
 399 };
 400 /* *INDENT-ON* */
 401
 402 /*
 403  * fd.io coding-style-patch-verification: ON
 404  *
 405  * Local Variables:
 406  * eval: (c-set-style "gnu")
 407  * End:
 408  */