src/vnet/ipsec/ah_encrypt.c

   1 /*
   2  * ah_encrypt.c : IPSec AH 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
  22 #include <vnet/ipsec/ipsec.h>
  23 #include <vnet/ipsec/esp.h>
  24 #include <vnet/ipsec/ah.h>
  25
  26 #define foreach_ah_encrypt_next \
  27   _ (DROP, "error-drop")            \
  28   _ (IP4_LOOKUP, "ip4-lookup")      \
  29   _ (IP6_LOOKUP, "ip6-lookup")      \
  30   _ (INTERFACE_OUTPUT, "interface-output")
  31
  32
  33 #define _(v, s) AH_ENCRYPT_NEXT_##v,
  34 typedef enum
  35 {
  36   foreach_ah_encrypt_next
  37 #undef _
  38     AH_ENCRYPT_N_NEXT,
  39 } ah_encrypt_next_t;
  40
  41 #define foreach_ah_encrypt_error                   \
  42  _(RX_PKTS, "AH pkts received")                    \
  43  _(SEQ_CYCLED, "sequence number cycled")
  44
  45
  46 typedef enum
  47 {
  48 #define _(sym,str) AH_ENCRYPT_ERROR_##sym,
  49   foreach_ah_encrypt_error
  50 #undef _
  51     AH_ENCRYPT_N_ERROR,
  52 } ah_encrypt_error_t;
  53
  54 static char *ah_encrypt_error_strings[] = {
  55 #define _(sym,string) string,
  56   foreach_ah_encrypt_error
  57 #undef _
  58 };
  59
  60 typedef struct
  61 {
  62   u32 sa_index;
  63   u32 spi;
  64   u32 seq;
  65   ipsec_integ_alg_t integ_alg;
  66 } ah_encrypt_trace_t;
  67
  68 /* packet trace format function */
  69 static u8 *
  70 format_ah_encrypt_trace (u8 * s, va_list * args)
  71 {
  72   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  73   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  74   ah_encrypt_trace_t *t = va_arg (*args, ah_encrypt_trace_t *);
  75
  76   s = format (s, "ah: sa-index %d spi %u seq %u integrity %U",
  77               t->sa_index, t->spi, t->seq,
  78               format_ipsec_integ_alg, t->integ_alg);
  79   return s;
  80 }
  81
  82 always_inline uword
  83 ah_encrypt_inline (vlib_main_t * vm,
  84                    vlib_node_runtime_t * node, vlib_frame_t * from_frame,
  85                    int is_ip6)
  86 {
  87   u32 n_left_from, *from, *to_next = 0, next_index;
  88   int icv_size = 0;
  89   from = vlib_frame_vector_args (from_frame);
  90   n_left_from = from_frame->n_vectors;
  91   ipsec_main_t *im = &ipsec_main;
  92   ipsec_proto_main_t *em = &ipsec_proto_main;
  93   next_index = node->cached_next_index;
  94
  95   while (n_left_from > 0)
  96     {
  97       u32 n_left_to_next;
  98
  99       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 100
 101       while (n_left_from > 0 && n_left_to_next > 0)
 102         {
 103           u32 i_bi0, next0;
 104           vlib_buffer_t *i_b0 = 0;
 105           u32 sa_index0;
 106           ipsec_sa_t *sa0;
 107           ip4_and_ah_header_t *ih0, *oh0 = 0;
 108           ip6_and_ah_header_t *ih6_0, *oh6_0 = 0;
 109           u8 ip_hdr_size;
 110           u8 next_hdr_type;
 111           u8 tos = 0;
 112           u8 ttl = 0;
 113           u8 hop_limit = 0;
 114           u32 ip_version_traffic_class_and_flow_label = 0;
 115
 116           i_bi0 = from[0];
 117           from += 1;
 118           n_left_from -= 1;
 119           n_left_to_next -= 1;
 120           next0 = AH_ENCRYPT_NEXT_DROP;
 121
 122           i_b0 = vlib_get_buffer (vm, i_bi0);
 123           to_next[0] = i_bi0;
 124           to_next += 1;
 125           sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
 126           sa0 = pool_elt_at_index (im->sad, sa_index0);
 127
 128           if (PREDICT_FALSE (esp_seq_advance (sa0)))
 129             {
 130               vlib_node_increment_counter (vm, node->node_index,
 131                                            AH_ENCRYPT_ERROR_SEQ_CYCLED, 1);
 132               goto trace;
 133             }
 134
 135
 136           sa0->total_data_size += i_b0->current_length;
 137
 138           ssize_t adv;
 139           ih0 = vlib_buffer_get_current (i_b0);
 140           ttl = ih0->ip4.ttl;
 141           tos = ih0->ip4.tos;
 142
 143           if (PREDICT_TRUE (sa0->is_tunnel))
 144             {
 145               if (is_ip6)
 146                 adv = -sizeof (ip6_and_ah_header_t);
 147               else
 148                 adv = -sizeof (ip4_and_ah_header_t);
 149             }
 150           else
 151             {
 152               adv = -sizeof (ah_header_t);
 153             }
 154
 155           icv_size =
 156             em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
 157           const u8 padding_len = ah_calc_icv_padding_len (icv_size, is_ip6);
 158           adv -= padding_len;
 159           /* transport mode save the eth header before it is overwritten */
 160           if (PREDICT_FALSE (!sa0->is_tunnel))
 161             {
 162               ethernet_header_t *ieh0 = (ethernet_header_t *)
 163                 ((u8 *) vlib_buffer_get_current (i_b0) -
 164                  sizeof (ethernet_header_t));
 165               ethernet_header_t *oeh0 =
 166                 (ethernet_header_t *) ((u8 *) ieh0 + (adv - icv_size));
 167               clib_memcpy_fast (oeh0, ieh0, sizeof (ethernet_header_t));
 168             }
 169
 170           vlib_buffer_advance (i_b0, adv - icv_size);
 171
 172           if (is_ip6)
 173             {
 174               ih6_0 = (ip6_and_ah_header_t *) ih0;
 175               ip_hdr_size = sizeof (ip6_header_t);
 176               oh6_0 = vlib_buffer_get_current (i_b0);
 177
 178               hop_limit = ih6_0->ip6.hop_limit;
 179               ip_version_traffic_class_and_flow_label =
 180                 ih6_0->ip6.ip_version_traffic_class_and_flow_label;
 181               if (PREDICT_TRUE (sa0->is_tunnel))
 182                 {
 183                   next_hdr_type = IP_PROTOCOL_IPV6;
 184                 }
 185               else
 186                 {
 187                   next_hdr_type = ih6_0->ip6.protocol;
 188                   memmove (oh6_0, ih6_0, sizeof (ip6_header_t));
 189                 }
 190
 191               oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_AH;
 192               oh6_0->ip6.hop_limit = 0;
 193               oh6_0->ip6.ip_version_traffic_class_and_flow_label = 0x60;
 194               oh6_0->ah.reserved = 0;
 195               oh6_0->ah.nexthdr = next_hdr_type;
 196               oh6_0->ah.spi = clib_net_to_host_u32 (sa0->spi);
 197               oh6_0->ah.seq_no = clib_net_to_host_u32 (sa0->seq);
 198               oh6_0->ip6.payload_length =
 199                 clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, i_b0) -
 200                                       sizeof (ip6_header_t));
 201               oh6_0->ah.hdrlen =
 202                 (sizeof (ah_header_t) + icv_size + padding_len) / 4 - 2;
 203             }
 204           else
 205             {
 206               ip_hdr_size = sizeof (ip4_header_t);
 207               oh0 = vlib_buffer_get_current (i_b0);
 208               clib_memset (oh0, 0, sizeof (ip4_and_ah_header_t));
 209
 210               if (PREDICT_TRUE (sa0->is_tunnel))
 211                 {
 212                   next_hdr_type = IP_PROTOCOL_IP_IN_IP;
 213                 }
 214               else
 215                 {
 216                   next_hdr_type = ih0->ip4.protocol;
 217                   memmove (oh0, ih0, sizeof (ip4_header_t));
 218                 }
 219
 220               oh0->ip4.length =
 221                 clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, i_b0));
 222               oh0->ip4.ip_version_and_header_length = 0x45;
 223               oh0->ip4.fragment_id = 0;
 224               oh0->ip4.flags_and_fragment_offset = 0;
 225               oh0->ip4.ttl = 0;
 226               oh0->ip4.tos = 0;
 227               oh0->ip4.protocol = IP_PROTOCOL_IPSEC_AH;
 228               oh0->ah.spi = clib_net_to_host_u32 (sa0->spi);
 229               oh0->ah.seq_no = clib_net_to_host_u32 (sa0->seq);
 230               oh0->ip4.checksum = 0;
 231               oh0->ah.nexthdr = next_hdr_type;
 232               oh0->ah.hdrlen =
 233                 (sizeof (ah_header_t) + icv_size + padding_len) / 4 - 2;
 234             }
 235
 236
 237           if (PREDICT_TRUE (!is_ip6 && sa0->is_tunnel && !sa0->is_tunnel_ip6))
 238             {
 239               oh0->ip4.src_address.as_u32 = sa0->tunnel_src_addr.ip4.as_u32;
 240               oh0->ip4.dst_address.as_u32 = sa0->tunnel_dst_addr.ip4.as_u32;
 241
 242               next0 = sa0->dpo[IPSEC_PROTOCOL_AH].dpoi_next_node;
 243               vnet_buffer (i_b0)->ip.adj_index[VLIB_TX] =
 244                 sa0->dpo[IPSEC_PROTOCOL_AH].dpoi_index;
 245             }
 246           else if (is_ip6 && sa0->is_tunnel && sa0->is_tunnel_ip6)
 247             {
 248               oh6_0->ip6.src_address.as_u64[0] =
 249                 sa0->tunnel_src_addr.ip6.as_u64[0];
 250               oh6_0->ip6.src_address.as_u64[1] =
 251                 sa0->tunnel_src_addr.ip6.as_u64[1];
 252               oh6_0->ip6.dst_address.as_u64[0] =
 253                 sa0->tunnel_dst_addr.ip6.as_u64[0];
 254               oh6_0->ip6.dst_address.as_u64[1] =
 255                 sa0->tunnel_dst_addr.ip6.as_u64[1];
 256
 257               next0 = sa0->dpo[IPSEC_PROTOCOL_AH].dpoi_next_node;
 258               vnet_buffer (i_b0)->ip.adj_index[VLIB_TX] =
 259                 sa0->dpo[IPSEC_PROTOCOL_AH].dpoi_index;
 260             }
 261
 262           u8 sig[64];
 263           clib_memset (sig, 0, sizeof (sig));
 264           u8 *digest =
 265             vlib_buffer_get_current (i_b0) + ip_hdr_size +
 266             sizeof (ah_header_t);
 267           clib_memset (digest, 0, icv_size);
 268
 269           unsigned size = hmac_calc (sa0->integ_alg, sa0->integ_key.data,
 270                                      sa0->integ_key.len,
 271                                      vlib_buffer_get_current (i_b0),
 272                                      i_b0->current_length, sig, sa0->use_esn,
 273                                      sa0->seq_hi);
 274
 275           memcpy (digest, sig, size);
 276           if (is_ip6)
 277             {
 278               oh6_0->ip6.hop_limit = hop_limit;
 279               oh6_0->ip6.ip_version_traffic_class_and_flow_label =
 280                 ip_version_traffic_class_and_flow_label;
 281             }
 282           else
 283             {
 284               oh0->ip4.ttl = ttl;
 285               oh0->ip4.tos = tos;
 286               oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
 287             }
 288
 289           if (!sa0->is_tunnel)
 290             {
 291               next0 = AH_ENCRYPT_NEXT_INTERFACE_OUTPUT;
 292               vlib_buffer_advance (i_b0, -sizeof (ethernet_header_t));
 293             }
 294
 295         trace:
 296           if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
 297             {
 298               i_b0->flags |= VLIB_BUFFER_IS_TRACED;
 299               ah_encrypt_trace_t *tr =
 300                 vlib_add_trace (vm, node, i_b0, sizeof (*tr));
 301               tr->spi = sa0->spi;
 302               tr->seq = sa0->seq - 1;
 303               tr->integ_alg = sa0->integ_alg;
 304               tr->sa_index = sa_index0;
 305             }
 306
 307           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 308                                            to_next, n_left_to_next, i_bi0,
 309                                            next0);
 310         }
 311       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 312     }
 313   vlib_node_increment_counter (vm, node->node_index,
 314                                AH_ENCRYPT_ERROR_RX_PKTS,
 315                                from_frame->n_vectors);
 316
 317   return from_frame->n_vectors;
 318 }
 319
 320 VLIB_NODE_FN (ah4_encrypt_node) (vlib_main_t * vm,
 321                                  vlib_node_runtime_t * node,
 322                                  vlib_frame_t * from_frame)
 323 {
 324   return ah_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
 325 }
 326
 327 /* *INDENT-OFF* */
 328 VLIB_REGISTER_NODE (ah4_encrypt_node) = {
 329   .name = "ah4-encrypt",
 330   .vector_size = sizeof (u32),
 331   .format_trace = format_ah_encrypt_trace,
 332   .type = VLIB_NODE_TYPE_INTERNAL,
 333
 334   .n_errors = ARRAY_LEN(ah_encrypt_error_strings),
 335   .error_strings = ah_encrypt_error_strings,
 336
 337   .n_next_nodes = AH_ENCRYPT_N_NEXT,
 338   .next_nodes = {
 339 #define _(s,n) [AH_ENCRYPT_NEXT_##s] = n,
 340     foreach_ah_encrypt_next
 341 #undef _
 342   },
 343 };
 344 /* *INDENT-ON* */
 345
 346 VLIB_NODE_FN (ah6_encrypt_node) (vlib_main_t * vm,
 347                                  vlib_node_runtime_t * node,
 348                                  vlib_frame_t * from_frame)
 349 {
 350   return ah_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
 351 }
 352
 353 /* *INDENT-OFF* */
 354 VLIB_REGISTER_NODE (ah6_encrypt_node) = {
 355   .name = "ah6-encrypt",
 356   .vector_size = sizeof (u32),
 357   .format_trace = format_ah_encrypt_trace,
 358   .type = VLIB_NODE_TYPE_INTERNAL,
 359
 360   .n_errors = ARRAY_LEN(ah_encrypt_error_strings),
 361   .error_strings = ah_encrypt_error_strings,
 362
 363   .n_next_nodes = AH_ENCRYPT_N_NEXT,
 364   .next_nodes = {
 365 #define _(s,n) [AH_ENCRYPT_NEXT_##s] = n,
 366     foreach_ah_encrypt_next
 367 #undef _
 368   },
 369 };
 370 /* *INDENT-ON* */
 371
 372 /*
 373  * fd.io coding-style-patch-verification: ON
 374  *
 375  * Local Variables:
 376  * eval: (c-set-style "gnu")
 377  * End:
 378  */