src/vnet/ipsec/ipsec_output.c

   1 /*
   2  * ipsec_output.c : IPSec output 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/ipsec_io.h>
  24 #include <vnet/ipsec/ipsec_output.h>
  25
  26 #define foreach_ipsec_output_error                   \
  27  _(RX_PKTS, "IPSec pkts received")                   \
  28  _(POLICY_DISCARD, "IPSec policy discard")           \
  29  _(POLICY_NO_MATCH, "IPSec policy (no match)")       \
  30  _(POLICY_PROTECT, "IPSec policy protect")           \
  31  _(POLICY_BYPASS, "IPSec policy bypass")             \
  32  _(ENCAPS_FAILED, "IPSec encapsulation failed")
  33
  34 typedef enum
  35 {
  36 #define _(sym,str) IPSEC_OUTPUT_ERROR_##sym,
  37   foreach_ipsec_output_error
  38 #undef _
  39     IPSEC_DECAP_N_ERROR,
  40 } ipsec_output_error_t;
  41
  42 static char *ipsec_output_error_strings[] = {
  43 #define _(sym,string) string,
  44   foreach_ipsec_output_error
  45 #undef _
  46 };
  47
  48 typedef struct
  49 {
  50   u32 spd_id;
  51   u32 policy_id;
  52 } ipsec_output_trace_t;
  53
  54 /* packet trace format function */
  55 static u8 *
  56 format_ipsec_output_trace (u8 * s, va_list * args)
  57 {
  58   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  59   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  60   ipsec_output_trace_t *t = va_arg (*args, ipsec_output_trace_t *);
  61
  62   s = format (s, "spd %u policy %d", t->spd_id, t->policy_id);
  63
  64   return s;
  65 }
  66
  67 always_inline uword
  68 ip6_addr_match_range (ip6_address_t * a, ip6_address_t * la,
  69                       ip6_address_t * ua)
  70 {
  71   if ((memcmp (a->as_u64, la->as_u64, 2 * sizeof (u64)) >= 0) &&
  72       (memcmp (a->as_u64, ua->as_u64, 2 * sizeof (u64)) <= 0))
  73     return 1;
  74   return 0;
  75 }
  76
  77 always_inline void
  78 ipsec_fp_5tuple_from_ip6_range (ipsec_fp_5tuple_t *tuple, ip6_address_t *la,
  79                                 ip6_address_t *ra, u16 lp, u16 rp, u8 pr)
  80
  81 {
  82   clib_memcpy_fast (&tuple->ip6_laddr, la, sizeof (ip6_address_t));
  83   clib_memcpy_fast (&tuple->ip6_laddr, la, sizeof (ip6_address_t));
  84
  85   tuple->lport = lp;
  86   tuple->rport = rp;
  87   tuple->protocol = pr;
  88   tuple->is_ipv6 = 1;
  89 }
  90
  91 always_inline ipsec_policy_t *
  92 ipsec6_output_policy_match (ipsec_spd_t * spd,
  93                             ip6_address_t * la,
  94                             ip6_address_t * ra, u16 lp, u16 rp, u8 pr)
  95 {
  96   ipsec_main_t *im = &ipsec_main;
  97   ipsec_policy_t *p;
  98   ipsec_policy_t *policies[1];
  99   ipsec_fp_5tuple_t tuples[1];
 100   u32 fp_policy_ids[1];
 101
 102   u32 *i;
 103
 104   if (!spd)
 105     return 0;
 106
 107   ipsec_fp_5tuple_from_ip6_range (&tuples[0], la, ra, lp, rp, pr);
 108   if (im->fp_spd_is_enabled &&
 109       (0 == ipsec_fp_out_policy_match_n (&spd->fp_spd, 1, tuples, policies,
 110                                          fp_policy_ids, 1)))
 111     {
 112       p = policies[0];
 113       i = fp_policy_ids;
 114     }
 115
 116   vec_foreach (i, spd->policies[IPSEC_SPD_POLICY_IP6_OUTBOUND])
 117   {
 118     p = pool_elt_at_index (im->policies, *i);
 119     if (PREDICT_FALSE ((p->protocol != IPSEC_POLICY_PROTOCOL_ANY) &&
 120                        (p->protocol != pr)))
 121       continue;
 122
 123     if (!ip6_addr_match_range (ra, &p->raddr.start.ip6, &p->raddr.stop.ip6))
 124       continue;
 125
 126     if (!ip6_addr_match_range (la, &p->laddr.start.ip6, &p->laddr.stop.ip6))
 127       continue;
 128
 129     if (PREDICT_FALSE
 130         ((pr != IP_PROTOCOL_TCP) && (pr != IP_PROTOCOL_UDP)
 131          && (pr != IP_PROTOCOL_SCTP)))
 132       return p;
 133
 134     if (lp < p->lport.start)
 135       continue;
 136
 137     if (lp > p->lport.stop)
 138       continue;
 139
 140     if (rp < p->rport.start)
 141       continue;
 142
 143     if (rp > p->rport.stop)
 144       continue;
 145
 146     return p;
 147   }
 148
 149   return 0;
 150 }
 151
 152 static inline uword
 153 ipsec_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 154                      vlib_frame_t * from_frame, int is_ipv6)
 155 {
 156   ipsec_main_t *im = &ipsec_main;
 157
 158   u32 *from, *to_next = 0, thread_index;
 159   u32 n_left_from, sw_if_index0, last_sw_if_index = (u32) ~ 0;
 160   u32 next_node_index = (u32) ~ 0, last_next_node_index = (u32) ~ 0;
 161   vlib_frame_t *f = 0;
 162   u32 spd_index0 = ~0;
 163   ipsec_spd_t *spd0 = 0;
 164   int bogus;
 165   u64 nc_protect = 0, nc_bypass = 0, nc_discard = 0, nc_nomatch = 0;
 166   u8 flow_cache_enabled = im->output_flow_cache_flag;
 167
 168   from = vlib_frame_vector_args (from_frame);
 169   n_left_from = from_frame->n_vectors;
 170   thread_index = vm->thread_index;
 171
 172   while (n_left_from > 0)
 173     {
 174       u32 bi0, pi0, bi1;
 175       vlib_buffer_t *b0, *b1;
 176       ipsec_policy_t *p0 = NULL;
 177       ip4_header_t *ip0;
 178       ip6_header_t *ip6_0 = 0;
 179       udp_header_t *udp0;
 180       u32 iph_offset = 0;
 181       tcp_header_t *tcp0;
 182       u64 bytes0;
 183
 184       bi0 = from[0];
 185       b0 = vlib_get_buffer (vm, bi0);
 186       if (n_left_from > 1)
 187         {
 188           bi1 = from[1];
 189           b1 = vlib_get_buffer (vm, bi1);
 190           CLIB_PREFETCH (b1, CLIB_CACHE_LINE_BYTES * 2, STORE);
 191           vlib_prefetch_buffer_data (b1, LOAD);
 192         }
 193       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 194       iph_offset = vnet_buffer (b0)->ip.save_rewrite_length;
 195       ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0)
 196                               + iph_offset);
 197
 198       /* lookup for SPD only if sw_if_index is changed */
 199       if (PREDICT_FALSE (last_sw_if_index != sw_if_index0))
 200         {
 201           uword *p = hash_get (im->spd_index_by_sw_if_index, sw_if_index0);
 202           ALWAYS_ASSERT (p);
 203           spd_index0 = p[0];
 204           spd0 = pool_elt_at_index (im->spds, spd_index0);
 205           last_sw_if_index = sw_if_index0;
 206         }
 207
 208       if (is_ipv6)
 209         {
 210           ip6_0 = (ip6_header_t *) ((u8 *) vlib_buffer_get_current (b0)
 211                                     + iph_offset);
 212
 213           udp0 = ip6_next_header (ip6_0);
 214 #if 0
 215           clib_warning
 216             ("packet received from %U port %u to %U port %u spd_id %u",
 217              format_ip6_address, &ip6_0->src_address,
 218              clib_net_to_host_u16 (udp0->src_port), format_ip6_address,
 219              &ip6_0->dst_address, clib_net_to_host_u16 (udp0->dst_port),
 220              spd0->id);
 221 #endif
 222
 223           p0 = ipsec6_output_policy_match (spd0,
 224                                            &ip6_0->src_address,
 225                                            &ip6_0->dst_address,
 226                                            clib_net_to_host_u16
 227                                            (udp0->src_port),
 228                                            clib_net_to_host_u16
 229                                            (udp0->dst_port), ip6_0->protocol);
 230         }
 231       else
 232         {
 233           udp0 = (udp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 234
 235 #if 0
 236           clib_warning ("packet received from %U to %U port %u",
 237                         format_ip4_address, ip0->src_address.as_u8,
 238                         format_ip4_address, ip0->dst_address.as_u8,
 239                         clib_net_to_host_u16 (udp0->dst_port));
 240           clib_warning ("sw_if_index0 %u spd_index0 %u spd_id %u",
 241                         sw_if_index0, spd_index0, spd0->id);
 242 #endif
 243
 244           /*
 245            * Check whether flow cache is enabled.
 246            */
 247           if (flow_cache_enabled)
 248             {
 249               p0 = ipsec4_out_spd_find_flow_cache_entry (
 250                 im, ip0->protocol, ip0->src_address.as_u32,
 251                 ip0->dst_address.as_u32, udp0->src_port, udp0->dst_port);
 252             }
 253
 254           /* Fall back to linear search if flow cache lookup fails */
 255           if (p0 == NULL)
 256             {
 257               p0 = ipsec_output_policy_match (
 258                 spd0, ip0->protocol,
 259                 clib_net_to_host_u32 (ip0->src_address.as_u32),
 260                 clib_net_to_host_u32 (ip0->dst_address.as_u32),
 261                 clib_net_to_host_u16 (udp0->src_port),
 262                 clib_net_to_host_u16 (udp0->dst_port), flow_cache_enabled);
 263             }
 264         }
 265       tcp0 = (void *) udp0;
 266
 267       if (PREDICT_TRUE (p0 != NULL))
 268         {
 269           pi0 = p0 - im->policies;
 270
 271           vlib_prefetch_combined_counter (&ipsec_spd_policy_counters,
 272                                           thread_index, pi0);
 273
 274           if (is_ipv6)
 275             {
 276               bytes0 = clib_net_to_host_u16 (ip6_0->payload_length);
 277               bytes0 += sizeof (ip6_header_t);
 278             }
 279           else
 280             {
 281               bytes0 = clib_net_to_host_u16 (ip0->length);
 282             }
 283
 284           if (p0->policy == IPSEC_POLICY_ACTION_PROTECT)
 285             {
 286               ipsec_sa_t *sa = 0;
 287               nc_protect++;
 288               sa = ipsec_sa_get (p0->sa_index);
 289               if (sa->protocol == IPSEC_PROTOCOL_ESP)
 290                 if (is_ipv6)
 291                   next_node_index = im->esp6_encrypt_node_index;
 292                 else
 293                   next_node_index = im->esp4_encrypt_node_index;
 294               else if (is_ipv6)
 295                 next_node_index = im->ah6_encrypt_node_index;
 296               else
 297                 next_node_index = im->ah4_encrypt_node_index;
 298               vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 299
 300               if (PREDICT_FALSE (b0->flags & VNET_BUFFER_F_OFFLOAD))
 301                 {
 302                   vnet_buffer_oflags_t oflags = vnet_buffer (b0)->oflags;
 303
 304                   /*
 305                    * Clearing offload flags before checksum is computed
 306                    * It guarantees the cache hit!
 307                    */
 308                   vnet_buffer_offload_flags_clear (b0, oflags);
 309
 310                   if (is_ipv6)
 311                     {
 312                       if (PREDICT_FALSE (oflags &
 313                                          VNET_BUFFER_OFFLOAD_F_TCP_CKSUM))
 314                         {
 315                           tcp0->checksum = ip6_tcp_udp_icmp_compute_checksum (
 316                             vm, b0, ip6_0, &bogus);
 317                         }
 318                       if (PREDICT_FALSE (oflags &
 319                                          VNET_BUFFER_OFFLOAD_F_UDP_CKSUM))
 320                         {
 321                           udp0->checksum = ip6_tcp_udp_icmp_compute_checksum (
 322                             vm, b0, ip6_0, &bogus);
 323                         }
 324                     }
 325                   else
 326                     {
 327                       if (PREDICT_FALSE (oflags &
 328                                          VNET_BUFFER_OFFLOAD_F_IP_CKSUM))
 329                         {
 330                           ip0->checksum = ip4_header_checksum (ip0);
 331                         }
 332                       if (PREDICT_FALSE (oflags &
 333                                          VNET_BUFFER_OFFLOAD_F_TCP_CKSUM))
 334                         {
 335                           tcp0->checksum =
 336                             ip4_tcp_udp_compute_checksum (vm, b0, ip0);
 337                         }
 338                       if (PREDICT_FALSE (oflags &
 339                                          VNET_BUFFER_OFFLOAD_F_UDP_CKSUM))
 340                         {
 341                           udp0->checksum =
 342                             ip4_tcp_udp_compute_checksum (vm, b0, ip0);
 343                         }
 344                     }
 345                 }
 346               vlib_buffer_advance (b0, iph_offset);
 347             }
 348           else if (p0->policy == IPSEC_POLICY_ACTION_BYPASS)
 349             {
 350               nc_bypass++;
 351               next_node_index = get_next_output_feature_node_index (b0, node);
 352             }
 353           else
 354             {
 355               nc_discard++;
 356               next_node_index = im->error_drop_node_index;
 357             }
 358           vlib_increment_combined_counter
 359             (&ipsec_spd_policy_counters, thread_index, pi0, 1, bytes0);
 360         }
 361       else
 362         {
 363           pi0 = ~0;
 364           nc_nomatch++;
 365           next_node_index = im->error_drop_node_index;
 366         }
 367
 368       from += 1;
 369       n_left_from -= 1;
 370
 371       if (PREDICT_FALSE ((last_next_node_index != next_node_index) || f == 0))
 372         {
 373           /* if this is not 1st frame */
 374           if (f)
 375             vlib_put_frame_to_node (vm, last_next_node_index, f);
 376
 377           last_next_node_index = next_node_index;
 378
 379           f = vlib_get_frame_to_node (vm, next_node_index);
 380
 381           /* frame->frame_flags, copy it from node */
 382           /* Copy trace flag from next_frame and from runtime. */
 383           f->frame_flags |= node->flags & VLIB_NODE_FLAG_TRACE;
 384
 385           to_next = vlib_frame_vector_args (f);
 386         }
 387
 388       to_next[0] = bi0;
 389       to_next += 1;
 390       f->n_vectors++;
 391
 392       if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 393           PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 394         {
 395           ipsec_output_trace_t *tr =
 396             vlib_add_trace (vm, node, b0, sizeof (*tr));
 397           if (spd0)
 398             tr->spd_id = spd0->id;
 399           tr->policy_id = pi0;
 400         }
 401     }
 402
 403   vlib_put_frame_to_node (vm, next_node_index, f);
 404   vlib_node_increment_counter (vm, node->node_index,
 405                                IPSEC_OUTPUT_ERROR_POLICY_PROTECT, nc_protect);
 406   vlib_node_increment_counter (vm, node->node_index,
 407                                IPSEC_OUTPUT_ERROR_POLICY_BYPASS, nc_bypass);
 408   vlib_node_increment_counter (vm, node->node_index,
 409                                IPSEC_OUTPUT_ERROR_POLICY_DISCARD, nc_discard);
 410   vlib_node_increment_counter (vm, node->node_index,
 411                                IPSEC_OUTPUT_ERROR_POLICY_NO_MATCH,
 412                                nc_nomatch);
 413   return from_frame->n_vectors;
 414 }
 415
 416 VLIB_NODE_FN (ipsec4_output_node) (vlib_main_t * vm,
 417                                    vlib_node_runtime_t * node,
 418                                    vlib_frame_t * frame)
 419 {
 420   return ipsec_output_inline (vm, node, frame, 0);
 421 }
 422
 423 /* *INDENT-OFF* */
 424 VLIB_REGISTER_NODE (ipsec4_output_node) = {
 425   .name = "ipsec4-output-feature",
 426   .vector_size = sizeof (u32),
 427   .format_trace = format_ipsec_output_trace,
 428   .type = VLIB_NODE_TYPE_INTERNAL,
 429
 430   .n_errors = ARRAY_LEN(ipsec_output_error_strings),
 431   .error_strings = ipsec_output_error_strings,
 432
 433   .n_next_nodes = IPSEC_OUTPUT_N_NEXT,
 434   .next_nodes = {
 435 #define _(s,n) [IPSEC_OUTPUT_NEXT_##s] = n,
 436     foreach_ipsec_output_next
 437 #undef _
 438   },
 439 };
 440 /* *INDENT-ON* */
 441
 442 VLIB_NODE_FN (ipsec6_output_node) (vlib_main_t * vm,
 443                                    vlib_node_runtime_t * node,
 444                                    vlib_frame_t * frame)
 445 {
 446   return ipsec_output_inline (vm, node, frame, 1);
 447 }
 448
 449 VLIB_REGISTER_NODE (ipsec6_output_node) = {
 450   .name = "ipsec6-output-feature",
 451   .vector_size = sizeof (u32),
 452   .format_trace = format_ipsec_output_trace,
 453   .type = VLIB_NODE_TYPE_INTERNAL,
 454
 455   .n_errors = ARRAY_LEN(ipsec_output_error_strings),
 456   .error_strings = ipsec_output_error_strings,
 457
 458   .n_next_nodes = IPSEC_OUTPUT_N_NEXT,
 459   .next_nodes = {
 460 #define _(s,n) [IPSEC_OUTPUT_NEXT_##s] = n,
 461     foreach_ipsec_output_next
 462 #undef _
 463   },
 464 };
 465