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