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 ipsec_policy_t *
  78 ipsec6_output_policy_match (ipsec_spd_t * spd,
  79                             ip6_address_t * la,
  80                             ip6_address_t * ra, u16 lp, u16 rp, u8 pr)
  81 {
  82   ipsec_main_t *im = &ipsec_main;
  83   ipsec_policy_t *p;
  84
  85   u32 *i;
  86
  87   if (!spd)
  88     return 0;
  89
  90   vec_foreach (i, spd->policies[IPSEC_SPD_POLICY_IP6_OUTBOUND])
  91   {
  92     p = pool_elt_at_index (im->policies, *i);
  93     if (PREDICT_FALSE ((p->protocol != IPSEC_POLICY_PROTOCOL_ANY) &&
  94                        (p->protocol != pr)))
  95       continue;
  96
  97     if (!ip6_addr_match_range (ra, &p->raddr.start.ip6, &p->raddr.stop.ip6))
  98       continue;
  99
 100     if (!ip6_addr_match_range (la, &p->laddr.start.ip6, &p->laddr.stop.ip6))
 101       continue;
 102
 103     if (PREDICT_FALSE
 104         ((pr != IP_PROTOCOL_TCP) && (pr != IP_PROTOCOL_UDP)
 105          && (pr != IP_PROTOCOL_SCTP)))
 106       return p;
 107
 108     if (lp < p->lport.start)
 109       continue;
 110
 111     if (lp > p->lport.stop)
 112       continue;
 113
 114     if (rp < p->rport.start)
 115       continue;
 116
 117     if (rp > p->rport.stop)
 118       continue;
 119
 120     return p;
 121   }
 122
 123   return 0;
 124 }
 125
 126 static inline uword
 127 ipsec_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 128                      vlib_frame_t * from_frame, int is_ipv6)
 129 {
 130   ipsec_main_t *im = &ipsec_main;
 131
 132   u32 *from, *to_next = 0, thread_index;
 133   u32 n_left_from, sw_if_index0, last_sw_if_index = (u32) ~ 0;
 134   u32 next_node_index = (u32) ~ 0, last_next_node_index = (u32) ~ 0;
 135   vlib_frame_t *f = 0;
 136   u32 spd_index0 = ~0;
 137   ipsec_spd_t *spd0 = 0;
 138   int bogus;
 139   u64 nc_protect = 0, nc_bypass = 0, nc_discard = 0, nc_nomatch = 0;
 140   u8 flow_cache_enabled = im->output_flow_cache_flag;
 141
 142   from = vlib_frame_vector_args (from_frame);
 143   n_left_from = from_frame->n_vectors;
 144   thread_index = vm->thread_index;
 145
 146   while (n_left_from > 0)
 147     {
 148       u32 bi0, pi0, bi1;
 149       vlib_buffer_t *b0, *b1;
 150       ipsec_policy_t *p0 = NULL;
 151       ip4_header_t *ip0;
 152       ip6_header_t *ip6_0 = 0;
 153       udp_header_t *udp0;
 154       u32 iph_offset = 0;
 155       tcp_header_t *tcp0;
 156       u64 bytes0;
 157
 158       bi0 = from[0];
 159       b0 = vlib_get_buffer (vm, bi0);
 160       if (n_left_from > 1)
 161         {
 162           bi1 = from[1];
 163           b1 = vlib_get_buffer (vm, bi1);
 164           CLIB_PREFETCH (b1, CLIB_CACHE_LINE_BYTES * 2, STORE);
 165           vlib_prefetch_buffer_data (b1, LOAD);
 166         }
 167       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 168       iph_offset = vnet_buffer (b0)->ip.save_rewrite_length;
 169       ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0)
 170                               + iph_offset);
 171
 172       /* lookup for SPD only if sw_if_index is changed */
 173       if (PREDICT_FALSE (last_sw_if_index != sw_if_index0))
 174         {
 175           uword *p = hash_get (im->spd_index_by_sw_if_index, sw_if_index0);
 176           ALWAYS_ASSERT (p);
 177           spd_index0 = p[0];
 178           spd0 = pool_elt_at_index (im->spds, spd_index0);
 179           last_sw_if_index = sw_if_index0;
 180         }
 181
 182       if (is_ipv6)
 183         {
 184           ip6_0 = (ip6_header_t *) ((u8 *) vlib_buffer_get_current (b0)
 185                                     + iph_offset);
 186
 187           udp0 = ip6_next_header (ip6_0);
 188 #if 0
 189           clib_warning
 190             ("packet received from %U port %u to %U port %u spd_id %u",
 191              format_ip6_address, &ip6_0->src_address,
 192              clib_net_to_host_u16 (udp0->src_port), format_ip6_address,
 193              &ip6_0->dst_address, clib_net_to_host_u16 (udp0->dst_port),
 194              spd0->id);
 195 #endif
 196
 197           p0 = ipsec6_output_policy_match (spd0,
 198                                            &ip6_0->src_address,
 199                                            &ip6_0->dst_address,
 200                                            clib_net_to_host_u16
 201                                            (udp0->src_port),
 202                                            clib_net_to_host_u16
 203                                            (udp0->dst_port), ip6_0->protocol);
 204         }
 205       else
 206         {
 207           udp0 = (udp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 208
 209 #if 0
 210           clib_warning ("packet received from %U to %U port %u",
 211                         format_ip4_address, ip0->src_address.as_u8,
 212                         format_ip4_address, ip0->dst_address.as_u8,
 213                         clib_net_to_host_u16 (udp0->dst_port));
 214           clib_warning ("sw_if_index0 %u spd_index0 %u spd_id %u",
 215                         sw_if_index0, spd_index0, spd0->id);
 216 #endif
 217
 218           /*
 219            * Check whether flow cache is enabled.
 220            */
 221           if (flow_cache_enabled)
 222             {
 223               p0 = ipsec4_out_spd_find_flow_cache_entry (
 224                 im, ip0->protocol, ip0->src_address.as_u32,
 225                 ip0->dst_address.as_u32, udp0->src_port, udp0->dst_port);
 226             }
 227
 228           /* Fall back to linear search if flow cache lookup fails */
 229           if (p0 == NULL)
 230             {
 231               p0 = ipsec_output_policy_match (
 232                 spd0, ip0->protocol,
 233                 clib_net_to_host_u32 (ip0->src_address.as_u32),
 234                 clib_net_to_host_u32 (ip0->dst_address.as_u32),
 235                 clib_net_to_host_u16 (udp0->src_port),
 236                 clib_net_to_host_u16 (udp0->dst_port), flow_cache_enabled);
 237             }
 238         }
 239       tcp0 = (void *) udp0;
 240
 241       if (PREDICT_TRUE (p0 != NULL))
 242         {
 243           pi0 = p0 - im->policies;
 244
 245           vlib_prefetch_combined_counter (&ipsec_spd_policy_counters,
 246                                           thread_index, pi0);
 247
 248           if (is_ipv6)
 249             {
 250               bytes0 = clib_net_to_host_u16 (ip6_0->payload_length);
 251               bytes0 += sizeof (ip6_header_t);
 252             }
 253           else
 254             {
 255               bytes0 = clib_net_to_host_u16 (ip0->length);
 256             }
 257
 258           if (p0->policy == IPSEC_POLICY_ACTION_PROTECT)
 259             {
 260               ipsec_sa_t *sa = 0;
 261               nc_protect++;
 262               sa = ipsec_sa_get (p0->sa_index);
 263               if (sa->protocol == IPSEC_PROTOCOL_ESP)
 264                 if (is_ipv6)
 265                   next_node_index = im->esp6_encrypt_node_index;
 266                 else
 267                   next_node_index = im->esp4_encrypt_node_index;
 268               else if (is_ipv6)
 269                 next_node_index = im->ah6_encrypt_node_index;
 270               else
 271                 next_node_index = im->ah4_encrypt_node_index;
 272               vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 273
 274               if (PREDICT_FALSE (b0->flags & VNET_BUFFER_F_OFFLOAD))
 275                 {
 276                   vnet_buffer_oflags_t oflags = vnet_buffer (b0)->oflags;
 277
 278                   /*
 279                    * Clearing offload flags before checksum is computed
 280                    * It guarantees the cache hit!
 281                    */
 282                   vnet_buffer_offload_flags_clear (b0, oflags);
 283
 284                   if (is_ipv6)
 285                     {
 286                       if (PREDICT_FALSE (oflags &
 287                                          VNET_BUFFER_OFFLOAD_F_TCP_CKSUM))
 288                         {
 289                           tcp0->checksum = ip6_tcp_udp_icmp_compute_checksum (
 290                             vm, b0, ip6_0, &bogus);
 291                         }
 292                       if (PREDICT_FALSE (oflags &
 293                                          VNET_BUFFER_OFFLOAD_F_UDP_CKSUM))
 294                         {
 295                           udp0->checksum = ip6_tcp_udp_icmp_compute_checksum (
 296                             vm, b0, ip6_0, &bogus);
 297                         }
 298                     }
 299                   else
 300                     {
 301                       if (PREDICT_FALSE (oflags &
 302                                          VNET_BUFFER_OFFLOAD_F_IP_CKSUM))
 303                         {
 304                           ip0->checksum = ip4_header_checksum (ip0);
 305                         }
 306                       if (PREDICT_FALSE (oflags &
 307                                          VNET_BUFFER_OFFLOAD_F_TCP_CKSUM))
 308                         {
 309                           tcp0->checksum =
 310                             ip4_tcp_udp_compute_checksum (vm, b0, ip0);
 311                         }
 312                       if (PREDICT_FALSE (oflags &
 313                                          VNET_BUFFER_OFFLOAD_F_UDP_CKSUM))
 314                         {
 315                           udp0->checksum =
 316                             ip4_tcp_udp_compute_checksum (vm, b0, ip0);
 317                         }
 318                     }
 319                 }
 320               vlib_buffer_advance (b0, iph_offset);
 321             }
 322           else if (p0->policy == IPSEC_POLICY_ACTION_BYPASS)
 323             {
 324               nc_bypass++;
 325               next_node_index = get_next_output_feature_node_index (b0, node);
 326             }
 327           else
 328             {
 329               nc_discard++;
 330               next_node_index = im->error_drop_node_index;
 331             }
 332           vlib_increment_combined_counter
 333             (&ipsec_spd_policy_counters, thread_index, pi0, 1, bytes0);
 334         }
 335       else
 336         {
 337           pi0 = ~0;
 338           nc_nomatch++;
 339           next_node_index = im->error_drop_node_index;
 340         }
 341
 342       from += 1;
 343       n_left_from -= 1;
 344
 345       if (PREDICT_FALSE ((last_next_node_index != next_node_index) || f == 0))
 346         {
 347           /* if this is not 1st frame */
 348           if (f)
 349             vlib_put_frame_to_node (vm, last_next_node_index, f);
 350
 351           last_next_node_index = next_node_index;
 352
 353           f = vlib_get_frame_to_node (vm, next_node_index);
 354
 355           /* frame->frame_flags, copy it from node */
 356           /* Copy trace flag from next_frame and from runtime. */
 357           f->frame_flags |= node->flags & VLIB_NODE_FLAG_TRACE;
 358
 359           to_next = vlib_frame_vector_args (f);
 360         }
 361
 362       to_next[0] = bi0;
 363       to_next += 1;
 364       f->n_vectors++;
 365
 366       if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 367           PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 368         {
 369           ipsec_output_trace_t *tr =
 370             vlib_add_trace (vm, node, b0, sizeof (*tr));
 371           if (spd0)
 372             tr->spd_id = spd0->id;
 373           tr->policy_id = pi0;
 374         }
 375     }
 376
 377   vlib_put_frame_to_node (vm, next_node_index, f);
 378   vlib_node_increment_counter (vm, node->node_index,
 379                                IPSEC_OUTPUT_ERROR_POLICY_PROTECT, nc_protect);
 380   vlib_node_increment_counter (vm, node->node_index,
 381                                IPSEC_OUTPUT_ERROR_POLICY_BYPASS, nc_bypass);
 382   vlib_node_increment_counter (vm, node->node_index,
 383                                IPSEC_OUTPUT_ERROR_POLICY_DISCARD, nc_discard);
 384   vlib_node_increment_counter (vm, node->node_index,
 385                                IPSEC_OUTPUT_ERROR_POLICY_NO_MATCH,
 386                                nc_nomatch);
 387   return from_frame->n_vectors;
 388 }
 389
 390 VLIB_NODE_FN (ipsec4_output_node) (vlib_main_t * vm,
 391                                    vlib_node_runtime_t * node,
 392                                    vlib_frame_t * frame)
 393 {
 394   return ipsec_output_inline (vm, node, frame, 0);
 395 }
 396
 397 /* *INDENT-OFF* */
 398 VLIB_REGISTER_NODE (ipsec4_output_node) = {
 399   .name = "ipsec4-output-feature",
 400   .vector_size = sizeof (u32),
 401   .format_trace = format_ipsec_output_trace,
 402   .type = VLIB_NODE_TYPE_INTERNAL,
 403
 404   .n_errors = ARRAY_LEN(ipsec_output_error_strings),
 405   .error_strings = ipsec_output_error_strings,
 406
 407   .n_next_nodes = IPSEC_OUTPUT_N_NEXT,
 408   .next_nodes = {
 409 #define _(s,n) [IPSEC_OUTPUT_NEXT_##s] = n,
 410     foreach_ipsec_output_next
 411 #undef _
 412   },
 413 };
 414 /* *INDENT-ON* */
 415
 416 VLIB_NODE_FN (ipsec6_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, 1);
 421 }
 422
 423 VLIB_REGISTER_NODE (ipsec6_output_node) = {
 424   .name = "ipsec6-output-feature",
 425   .vector_size = sizeof (u32),
 426   .format_trace = format_ipsec_output_trace,
 427   .type = VLIB_NODE_TYPE_INTERNAL,
 428
 429   .n_errors = ARRAY_LEN(ipsec_output_error_strings),
 430   .error_strings = ipsec_output_error_strings,
 431
 432   .n_next_nodes = IPSEC_OUTPUT_N_NEXT,
 433   .next_nodes = {
 434 #define _(s,n) [IPSEC_OUTPUT_NEXT_##s] = n,
 435     foreach_ipsec_output_next
 436 #undef _
 437   },
 438 };
 439