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   _(SPI_0, "SPI 0")
  36
  37 static char *ipsec_tun_protect_input_error_strings[] = {
  38 #define _(sym,string) string,
  39   foreach_ipsec_tun_protect_input_error
  40 #undef _
  41 };
  42
  43 typedef enum
  44 {
  45 #define _(sym,str) IPSEC_TUN_PROTECT_INPUT_ERROR_##sym,
  46   foreach_ipsec_tun_protect_input_error
  47 #undef _
  48     IPSEC_TUN_PROTECT_INPUT_N_ERROR,
  49 } ipsec_tun_protect_input_error_t;
  50
  51 typedef enum ipsec_tun_next_t_
  52 {
  53 #define _(v, s) IPSEC_TUN_PROTECT_NEXT_##v,
  54   foreach_ipsec_input_next
  55 #undef _
  56     IPSEC_TUN_PROTECT_NEXT_DECRYPT,
  57   IPSEC_TUN_PROTECT_N_NEXT,
  58 } ipsec_tun_next_t;
  59
  60 typedef struct
  61 {
  62   u32 spi;
  63   u32 seq;
  64 } ipsec_tun_protect_input_trace_t;
  65
  66 static u8 *
  67 format_ipsec_tun_protect_input_trace (u8 * s, va_list * args)
  68 {
  69   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  70   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  71   ipsec_tun_protect_input_trace_t *t =
  72     va_arg (*args, ipsec_tun_protect_input_trace_t *);
  73
  74   s = format (s, "IPSec: spi %u seq %u", t->spi, t->seq);
  75   return s;
  76 }
  77
  78 always_inline u16
  79 ipsec_ip4_if_no_tunnel (vlib_node_runtime_t * node,
  80                         vlib_buffer_t * b,
  81                         const esp_header_t * esp, const ip4_header_t * ip4)
  82 {
  83   if (PREDICT_FALSE (0 == esp->spi))
  84     {
  85       b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_SPI_0];
  86       b->punt_reason = ipsec_punt_reason[(ip4->protocol == IP_PROTOCOL_UDP ?
  87                                           IPSEC_PUNT_IP4_SPI_UDP_0 :
  88                                           IPSEC_PUNT_IP4_SPI_0)];
  89     }
  90   else
  91     {
  92       b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL];
  93       b->punt_reason = ipsec_punt_reason[IPSEC_PUNT_IP4_NO_SUCH_TUNNEL];
  94     }
  95   return IPSEC_INPUT_NEXT_PUNT;
  96 }
  97
  98 always_inline u16
  99 ipsec_ip6_if_no_tunnel (vlib_node_runtime_t * node,
 100                         vlib_buffer_t * b, const esp_header_t * esp)
 101 {
 102   if (PREDICT_FALSE (0 == esp->spi))
 103     {
 104       b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL];
 105       b->punt_reason = ipsec_punt_reason[IPSEC_PUNT_IP6_SPI_0];
 106     }
 107   else
 108     {
 109       b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL];
 110       b->punt_reason = ipsec_punt_reason[IPSEC_PUNT_IP6_NO_SUCH_TUNNEL];
 111     }
 112   return (IPSEC_INPUT_NEXT_PUNT);
 113 }
 114
 115 always_inline uword
 116 ipsec_tun_protect_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 117                                 vlib_frame_t * from_frame, int is_ip6)
 118 {
 119   ipsec_main_t *im = &ipsec_main;
 120   vnet_main_t *vnm = im->vnet_main;
 121   vnet_interface_main_t *vim = &vnm->interface_main;
 122
 123   int is_trace = node->flags & VLIB_NODE_FLAG_TRACE;
 124   u32 thread_index = vm->thread_index;
 125
 126   u32 n_left_from, *from;
 127   u16 nexts[VLIB_FRAME_SIZE], *next;
 128   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
 129
 130   from = vlib_frame_vector_args (from_frame);
 131   n_left_from = from_frame->n_vectors;
 132
 133   vlib_get_buffers (vm, from, bufs, n_left_from);
 134   b = bufs;
 135   next = nexts;
 136
 137   clib_memset_u16 (nexts, im->esp4_decrypt_next_index, n_left_from);
 138
 139   u64 n_bytes = 0, n_packets = 0;
 140   u32 n_disabled = 0, n_no_tunnel = 0;
 141
 142   u32 last_sw_if_index = ~0;
 143   ipsec_tun_lkup_result_t last_result = {
 144     .tun_index = ~0
 145   };
 146   ipsec4_tunnel_key_t last_key4;
 147   ipsec6_tunnel_key_t last_key6;
 148
 149   vlib_combined_counter_main_t *rx_counter;
 150   vlib_combined_counter_main_t *drop_counter;
 151   ipsec_tun_protect_t *itp0;
 152
 153   if (is_ip6)
 154     clib_memset (&last_key6, 0xff, sizeof (last_key6));
 155   else
 156     last_key4.as_u64 = ~0;
 157
 158   rx_counter = vim->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX;
 159   drop_counter = vim->combined_sw_if_counters + VNET_INTERFACE_COUNTER_DROP;
 160
 161   while (n_left_from > 0)
 162     {
 163       u32 sw_if_index0, len0, hdr_sz0;
 164       ipsec_tun_lkup_result_t itr0;
 165       ipsec4_tunnel_key_t key40;
 166       ipsec6_tunnel_key_t key60;
 167       ip4_header_t *ip40;
 168       ip6_header_t *ip60;
 169       esp_header_t *esp0;
 170
 171       ip40 = vlib_buffer_get_current (b[0]);
 172
 173       if (is_ip6)
 174         {
 175           ip60 = (ip6_header_t *) ip40;
 176           esp0 = (esp_header_t *) (ip60 + 1);
 177           hdr_sz0 = sizeof (ip6_header_t);
 178         }
 179       else
 180         {
 181           /* NAT UDP port 4500 case, don't advance any more */
 182           if (ip40->protocol == IP_PROTOCOL_UDP)
 183             {
 184               esp0 =
 185                 (esp_header_t *) ((u8 *) ip40 + ip4_header_bytes (ip40) +
 186                                   sizeof (udp_header_t));
 187               hdr_sz0 = 0;
 188             }
 189           else
 190             {
 191               esp0 = (esp_header_t *) ((u8 *) ip40 + ip4_header_bytes (ip40));
 192               hdr_sz0 = ip4_header_bytes (ip40);
 193             }
 194         }
 195
 196       /* stats for the tunnel include all the data after the IP header
 197          just like a norml IP-IP tunnel */
 198       vlib_buffer_advance (b[0], hdr_sz0);
 199       len0 = vlib_buffer_length_in_chain (vm, b[0]);
 200
 201       if (is_ip6)
 202         {
 203           key60.remote_ip = ip60->src_address;
 204           key60.spi = esp0->spi;
 205
 206           if (memcmp (&key60, &last_key6, sizeof (last_key6)) == 0)
 207             {
 208               itr0 = last_result;
 209             }
 210           else
 211             {
 212               uword *p = hash_get_mem (im->tun6_protect_by_key, &key60);
 213               if (p)
 214                 {
 215                   itr0.as_u64 = p[0];
 216                   last_result = itr0;
 217                   clib_memcpy_fast (&last_key6, &key60, sizeof (key60));
 218                 }
 219               else
 220                 {
 221                   next[0] = ipsec_ip6_if_no_tunnel (node, b[0], esp0);
 222                   n_no_tunnel++;
 223                   goto trace00;
 224                 }
 225             }
 226         }
 227       else
 228         {
 229           key40.remote_ip = ip40->src_address.as_u32;
 230           key40.spi = esp0->spi;
 231
 232           if (key40.as_u64 == last_key4.as_u64)
 233             {
 234               itr0 = last_result;
 235             }
 236           else
 237             {
 238               uword *p = hash_get (im->tun4_protect_by_key, key40.as_u64);
 239               if (p)
 240                 {
 241                   itr0.as_u64 = p[0];
 242                   last_result = itr0;
 243                   last_key4.as_u64 = key40.as_u64;
 244                 }
 245               else
 246                 {
 247                   next[0] = ipsec_ip4_if_no_tunnel (node, b[0], esp0, ip40);
 248                   n_no_tunnel++;
 249                   goto trace00;
 250                 }
 251             }
 252         }
 253
 254       itp0 = pool_elt_at_index (ipsec_protect_pool, itr0.tun_index);
 255       vnet_buffer (b[0])->ipsec.sad_index = itr0.sa_index;
 256       vnet_buffer (b[0])->ipsec.protect_index = itr0.tun_index;
 257
 258       sw_if_index0 = itp0->itp_sw_if_index;
 259       vnet_buffer (b[0])->sw_if_index[VLIB_RX] = sw_if_index0;
 260
 261       if (PREDICT_FALSE (!vnet_sw_interface_is_admin_up (vnm, sw_if_index0)))
 262         {
 263           vlib_increment_combined_counter
 264             (drop_counter, thread_index, sw_if_index0, 1, len0);
 265           n_disabled++;
 266           b[0]->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_DISABLED];
 267           next[0] = IPSEC_INPUT_NEXT_DROP;
 268           goto trace00;
 269         }
 270       else
 271         {
 272           if (PREDICT_TRUE (sw_if_index0 == last_sw_if_index))
 273             {
 274               n_packets++;
 275               n_bytes += len0;
 276             }
 277           else
 278             {
 279               if (n_packets && !(itp0->itp_flags & IPSEC_PROTECT_ENCAPED))
 280                 {
 281                   vlib_increment_combined_counter
 282                     (rx_counter, thread_index, last_sw_if_index,
 283                      n_packets, n_bytes);
 284                 }
 285
 286               last_sw_if_index = sw_if_index0;
 287               n_packets = 1;
 288               n_bytes = len0;
 289             }
 290
 291           /*
 292            * compare the packet's outer IP headers to that of the tunnels
 293            */
 294           if (is_ip6)
 295             {
 296               if (PREDICT_FALSE
 297                   (!ip46_address_is_equal_v6
 298                    (&itp0->itp_crypto.dst, &ip60->src_address)
 299                    || !ip46_address_is_equal_v6 (&itp0->itp_crypto.src,
 300                                                  &ip60->dst_address)))
 301                 {
 302                   b[0]->error =
 303                     node->errors
 304                     [IPSEC_TUN_PROTECT_INPUT_ERROR_TUNNEL_MISMATCH];
 305                   next[0] = IPSEC_INPUT_NEXT_DROP;
 306                   goto trace00;
 307                 }
 308             }
 309           else
 310             {
 311               if (PREDICT_FALSE
 312                   (!ip46_address_is_equal_v4
 313                    (&itp0->itp_crypto.dst, &ip40->src_address)
 314                    || !ip46_address_is_equal_v4 (&itp0->itp_crypto.src,
 315                                                  &ip40->dst_address)))
 316                 {
 317                   b[0]->error =
 318                     node->errors
 319                     [IPSEC_TUN_PROTECT_INPUT_ERROR_TUNNEL_MISMATCH];
 320                   next[0] = IPSEC_INPUT_NEXT_DROP;
 321                   goto trace00;
 322                 }
 323             }
 324
 325           /*
 326            * There are two encap possibilities
 327            * 1) the tunnel and ths SA are prodiving encap, i.e. it's
 328            *   MAC | SA-IP | TUN-IP | ESP | PAYLOAD
 329            * implying the SA is in tunnel mode (on a tunnel interface)
 330            * 2) only the tunnel provides encap
 331            *   MAC | TUN-IP | ESP | PAYLOAD
 332            * implying the SA is in transport mode.
 333            *
 334            * For 2) we need only strip the tunnel encap and we're good.
 335            *  since the tunnel and crypto ecnap (int the tun=protect
 336            * object) are the same and we verified above that these match
 337            * for 1) we need to strip the SA-IP outer headers, to
 338            * reveal the tunnel IP and then check that this matches
 339            * the configured tunnel. this we can;t do here since it
 340            * involves a lookup in the per-tunnel-type DB - so ship
 341            * the packet to the tunnel-types provided node to do that
 342            */
 343           next[0] = IPSEC_TUN_PROTECT_NEXT_DECRYPT;
 344         }
 345     trace00:
 346       if (PREDICT_FALSE (is_trace))
 347         {
 348           if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
 349             {
 350               ipsec_tun_protect_input_trace_t *tr =
 351                 vlib_add_trace (vm, node, b[0], sizeof (*tr));
 352               tr->spi = clib_host_to_net_u32 (esp0->spi);
 353               tr->seq = clib_host_to_net_u32 (esp0->seq);
 354             }
 355         }
 356
 357       /* next */
 358       b += 1;
 359       next += 1;
 360       n_left_from -= 1;
 361     }
 362
 363   if (n_packets && !(itp0->itp_flags & IPSEC_PROTECT_ENCAPED))
 364     {
 365       vlib_increment_combined_counter (rx_counter,
 366                                        thread_index,
 367                                        last_sw_if_index, n_packets, n_bytes);
 368     }
 369
 370   vlib_node_increment_counter (vm, node->node_index,
 371                                IPSEC_TUN_PROTECT_INPUT_ERROR_RX,
 372                                from_frame->n_vectors - (n_disabled +
 373                                                         n_no_tunnel));
 374
 375   vlib_buffer_enqueue_to_next (vm, node, from, nexts, from_frame->n_vectors);
 376
 377   return from_frame->n_vectors;
 378 }
 379
 380 VLIB_NODE_FN (ipsec4_tun_input_node) (vlib_main_t * vm,
 381                                       vlib_node_runtime_t * node,
 382                                       vlib_frame_t * from_frame)
 383 {
 384   return ipsec_tun_protect_input_inline (vm, node, from_frame,
 385                                          0 /* is_ip6 */ );
 386 }
 387
 388 /* *INDENT-OFF* */
 389 VLIB_REGISTER_NODE (ipsec4_tun_input_node) = {
 390   .name = "ipsec4-tun-input",
 391   .vector_size = sizeof (u32),
 392   .format_trace = format_ipsec_tun_protect_input_trace,
 393   .type = VLIB_NODE_TYPE_INTERNAL,
 394   .n_errors = ARRAY_LEN(ipsec_tun_protect_input_error_strings),
 395   .error_strings = ipsec_tun_protect_input_error_strings,
 396   .n_next_nodes = IPSEC_TUN_PROTECT_N_NEXT,
 397   .next_nodes = {
 398     [IPSEC_TUN_PROTECT_NEXT_DROP] = "ip4-drop",
 399     [IPSEC_TUN_PROTECT_NEXT_PUNT] = "punt-dispatch",
 400     [IPSEC_TUN_PROTECT_NEXT_DECRYPT] = "esp4-decrypt-tun",
 401   }
 402 };
 403 /* *INDENT-ON* */
 404
 405 VLIB_NODE_FN (ipsec6_tun_input_node) (vlib_main_t * vm,
 406                                       vlib_node_runtime_t * node,
 407                                       vlib_frame_t * from_frame)
 408 {
 409   return ipsec_tun_protect_input_inline (vm, node, from_frame,
 410                                          1 /* is_ip6 */ );
 411 }
 412
 413 /* *INDENT-OFF* */
 414 VLIB_REGISTER_NODE (ipsec6_tun_input_node) = {
 415   .name = "ipsec6-tun-input",
 416   .vector_size = sizeof (u32),
 417   .format_trace = format_ipsec_tun_protect_input_trace,
 418   .type = VLIB_NODE_TYPE_INTERNAL,
 419   .n_errors = ARRAY_LEN(ipsec_tun_protect_input_error_strings),
 420   .error_strings = ipsec_tun_protect_input_error_strings,
 421   .n_next_nodes = IPSEC_TUN_PROTECT_N_NEXT,
 422   .next_nodes = {
 423     [IPSEC_TUN_PROTECT_NEXT_DROP] = "ip6-drop",
 424     [IPSEC_TUN_PROTECT_NEXT_PUNT] = "punt-dispatch",
 425     [IPSEC_TUN_PROTECT_NEXT_DECRYPT] = "esp6-decrypt-tun",
 426   }
 427 };
 428 /* *INDENT-ON* */
 429
 430 /*
 431  * fd.io coding-style-patch-verification: ON
 432  *
 433  * Local Variables:
 434  * eval: (c-set-style "gnu")
 435  * End:
 436  */