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 static inline uword
  68 ipsec_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
  69                      vlib_frame_t * from_frame, int is_ipv6)
  70 {
  71   ipsec_main_t *im = &ipsec_main;
  72
  73   u32 *from, *to_next = 0, thread_index;
  74   u32 n_left_from, sw_if_index0, last_sw_if_index = (u32) ~ 0;
  75   u32 next_node_index = (u32) ~ 0, last_next_node_index = (u32) ~ 0;
  76   vlib_frame_t *f = 0;
  77   u32 spd_index0 = ~0;
  78   ipsec_spd_t *spd0 = 0;
  79   int bogus;
  80   u64 nc_protect = 0, nc_bypass = 0, nc_discard = 0, nc_nomatch = 0;
  81   u8 flow_cache_enabled = im->output_flow_cache_flag;
  82
  83   from = vlib_frame_vector_args (from_frame);
  84   n_left_from = from_frame->n_vectors;
  85   thread_index = vm->thread_index;
  86
  87   while (n_left_from > 0)
  88     {
  89       u32 bi0, pi0, bi1;
  90       vlib_buffer_t *b0, *b1;
  91       ipsec_policy_t *p0 = NULL;
  92       ip4_header_t *ip0;
  93       ip6_header_t *ip6_0 = 0;
  94       udp_header_t *udp0;
  95       u32 iph_offset = 0;
  96       tcp_header_t *tcp0;
  97       u64 bytes0;
  98
  99       bi0 = from[0];
 100       b0 = vlib_get_buffer (vm, bi0);
 101       if (n_left_from > 1)
 102         {
 103           bi1 = from[1];
 104           b1 = vlib_get_buffer (vm, bi1);
 105           CLIB_PREFETCH (b1, CLIB_CACHE_LINE_BYTES * 2, STORE);
 106           vlib_prefetch_buffer_data (b1, LOAD);
 107         }
 108       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 109       iph_offset = vnet_buffer (b0)->ip.save_rewrite_length;
 110       ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0)
 111                               + iph_offset);
 112
 113       /* lookup for SPD only if sw_if_index is changed */
 114       if (PREDICT_FALSE (last_sw_if_index != sw_if_index0))
 115         {
 116           uword *p = hash_get (im->spd_index_by_sw_if_index, sw_if_index0);
 117           ALWAYS_ASSERT (p);
 118           spd_index0 = p[0];
 119           spd0 = pool_elt_at_index (im->spds, spd_index0);
 120           last_sw_if_index = sw_if_index0;
 121         }
 122
 123       if (is_ipv6)
 124         {
 125           ip6_0 = (ip6_header_t *) ((u8 *) vlib_buffer_get_current (b0)
 126                                     + iph_offset);
 127
 128           udp0 = ip6_next_header (ip6_0);
 129 #if 0
 130           clib_warning
 131             ("packet received from %U port %u to %U port %u spd_id %u",
 132              format_ip6_address, &ip6_0->src_address,
 133              clib_net_to_host_u16 (udp0->src_port), format_ip6_address,
 134              &ip6_0->dst_address, clib_net_to_host_u16 (udp0->dst_port),
 135              spd0->id);
 136 #endif
 137
 138           p0 = ipsec6_output_policy_match (spd0,
 139                                            &ip6_0->src_address,
 140                                            &ip6_0->dst_address,
 141                                            clib_net_to_host_u16
 142                                            (udp0->src_port),
 143                                            clib_net_to_host_u16
 144                                            (udp0->dst_port), ip6_0->protocol);
 145         }
 146       else
 147         {
 148           udp0 = (udp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 149
 150 #if 0
 151           clib_warning ("packet received from %U to %U port %u",
 152                         format_ip4_address, ip0->src_address.as_u8,
 153                         format_ip4_address, ip0->dst_address.as_u8,
 154                         clib_net_to_host_u16 (udp0->dst_port));
 155           clib_warning ("sw_if_index0 %u spd_index0 %u spd_id %u",
 156                         sw_if_index0, spd_index0, spd0->id);
 157 #endif
 158
 159           /*
 160            * Check whether flow cache is enabled.
 161            */
 162           if (flow_cache_enabled)
 163             {
 164               p0 = ipsec4_out_spd_find_flow_cache_entry (
 165                 im, ip0->protocol, ip0->src_address.as_u32,
 166                 ip0->dst_address.as_u32, udp0->src_port, udp0->dst_port);
 167             }
 168
 169           /* Fall back to linear search if flow cache lookup fails */
 170           if (p0 == NULL)
 171             {
 172               p0 = ipsec_output_policy_match (
 173                 spd0, ip0->protocol,
 174                 clib_net_to_host_u32 (ip0->src_address.as_u32),
 175                 clib_net_to_host_u32 (ip0->dst_address.as_u32),
 176                 clib_net_to_host_u16 (udp0->src_port),
 177                 clib_net_to_host_u16 (udp0->dst_port), flow_cache_enabled);
 178             }
 179         }
 180       tcp0 = (void *) udp0;
 181
 182       if (PREDICT_TRUE (p0 != NULL))
 183         {
 184           pi0 = p0 - im->policies;
 185
 186           vlib_prefetch_combined_counter (&ipsec_spd_policy_counters,
 187                                           thread_index, pi0);
 188
 189           if (is_ipv6)
 190             {
 191               bytes0 = clib_net_to_host_u16 (ip6_0->payload_length);
 192               bytes0 += sizeof (ip6_header_t);
 193             }
 194           else
 195             {
 196               bytes0 = clib_net_to_host_u16 (ip0->length);
 197             }
 198
 199           if (p0->policy == IPSEC_POLICY_ACTION_PROTECT)
 200             {
 201               ipsec_sa_t *sa = 0;
 202               nc_protect++;
 203               sa = ipsec_sa_get (p0->sa_index);
 204               if (sa->protocol == IPSEC_PROTOCOL_ESP)
 205                 if (is_ipv6)
 206                   next_node_index = im->esp6_encrypt_node_index;
 207                 else
 208                   next_node_index = im->esp4_encrypt_node_index;
 209               else if (is_ipv6)
 210                 next_node_index = im->ah6_encrypt_node_index;
 211               else
 212                 next_node_index = im->ah4_encrypt_node_index;
 213               vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 214
 215               if (PREDICT_FALSE (b0->flags & VNET_BUFFER_F_OFFLOAD))
 216                 {
 217                   vnet_buffer_oflags_t oflags = vnet_buffer (b0)->oflags;
 218
 219                   /*
 220                    * Clearing offload flags before checksum is computed
 221                    * It guarantees the cache hit!
 222                    */
 223                   vnet_buffer_offload_flags_clear (b0, oflags);
 224
 225                   if (is_ipv6)
 226                     {
 227                       if (PREDICT_FALSE (oflags &
 228                                          VNET_BUFFER_OFFLOAD_F_TCP_CKSUM))
 229                         {
 230                           tcp0->checksum = ip6_tcp_udp_icmp_compute_checksum (
 231                             vm, b0, ip6_0, &bogus);
 232                         }
 233                       if (PREDICT_FALSE (oflags &
 234                                          VNET_BUFFER_OFFLOAD_F_UDP_CKSUM))
 235                         {
 236                           udp0->checksum = ip6_tcp_udp_icmp_compute_checksum (
 237                             vm, b0, ip6_0, &bogus);
 238                         }
 239                     }
 240                   else
 241                     {
 242                       if (PREDICT_FALSE (oflags &
 243                                          VNET_BUFFER_OFFLOAD_F_IP_CKSUM))
 244                         {
 245                           ip0->checksum = ip4_header_checksum (ip0);
 246                         }
 247                       if (PREDICT_FALSE (oflags &
 248                                          VNET_BUFFER_OFFLOAD_F_TCP_CKSUM))
 249                         {
 250                           tcp0->checksum =
 251                             ip4_tcp_udp_compute_checksum (vm, b0, ip0);
 252                         }
 253                       if (PREDICT_FALSE (oflags &
 254                                          VNET_BUFFER_OFFLOAD_F_UDP_CKSUM))
 255                         {
 256                           udp0->checksum =
 257                             ip4_tcp_udp_compute_checksum (vm, b0, ip0);
 258                         }
 259                     }
 260                 }
 261               vlib_buffer_advance (b0, iph_offset);
 262             }
 263           else if (p0->policy == IPSEC_POLICY_ACTION_BYPASS)
 264             {
 265               nc_bypass++;
 266               next_node_index = get_next_output_feature_node_index (b0, node);
 267             }
 268           else
 269             {
 270               nc_discard++;
 271               next_node_index = im->error_drop_node_index;
 272             }
 273           vlib_increment_combined_counter
 274             (&ipsec_spd_policy_counters, thread_index, pi0, 1, bytes0);
 275         }
 276       else
 277         {
 278           pi0 = ~0;
 279           nc_nomatch++;
 280           next_node_index = im->error_drop_node_index;
 281         }
 282
 283       from += 1;
 284       n_left_from -= 1;
 285
 286       if (PREDICT_FALSE ((last_next_node_index != next_node_index) || f == 0))
 287         {
 288           /* if this is not 1st frame */
 289           if (f)
 290             vlib_put_frame_to_node (vm, last_next_node_index, f);
 291
 292           last_next_node_index = next_node_index;
 293
 294           f = vlib_get_frame_to_node (vm, next_node_index);
 295
 296           /* frame->frame_flags, copy it from node */
 297           /* Copy trace flag from next_frame and from runtime. */
 298           f->frame_flags |= node->flags & VLIB_NODE_FLAG_TRACE;
 299
 300           to_next = vlib_frame_vector_args (f);
 301         }
 302
 303       to_next[0] = bi0;
 304       to_next += 1;
 305       f->n_vectors++;
 306
 307       if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 308           PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 309         {
 310           ipsec_output_trace_t *tr =
 311             vlib_add_trace (vm, node, b0, sizeof (*tr));
 312           if (spd0)
 313             tr->spd_id = spd0->id;
 314           tr->policy_id = pi0;
 315         }
 316     }
 317
 318   vlib_put_frame_to_node (vm, next_node_index, f);
 319   vlib_node_increment_counter (vm, node->node_index,
 320                                IPSEC_OUTPUT_ERROR_POLICY_PROTECT, nc_protect);
 321   vlib_node_increment_counter (vm, node->node_index,
 322                                IPSEC_OUTPUT_ERROR_POLICY_BYPASS, nc_bypass);
 323   vlib_node_increment_counter (vm, node->node_index,
 324                                IPSEC_OUTPUT_ERROR_POLICY_DISCARD, nc_discard);
 325   vlib_node_increment_counter (vm, node->node_index,
 326                                IPSEC_OUTPUT_ERROR_POLICY_NO_MATCH,
 327                                nc_nomatch);
 328   return from_frame->n_vectors;
 329 }
 330
 331 VLIB_NODE_FN (ipsec4_output_node) (vlib_main_t * vm,
 332                                    vlib_node_runtime_t * node,
 333                                    vlib_frame_t * frame)
 334 {
 335   return ipsec_output_inline (vm, node, frame, 0);
 336 }
 337
 338 VLIB_REGISTER_NODE (ipsec4_output_node) = {
 339   .name = "ipsec4-output-feature",
 340   .vector_size = sizeof (u32),
 341   .format_trace = format_ipsec_output_trace,
 342   .type = VLIB_NODE_TYPE_INTERNAL,
 343
 344   .n_errors = ARRAY_LEN(ipsec_output_error_strings),
 345   .error_strings = ipsec_output_error_strings,
 346
 347   .n_next_nodes = IPSEC_OUTPUT_N_NEXT,
 348   .next_nodes = {
 349 #define _(s,n) [IPSEC_OUTPUT_NEXT_##s] = n,
 350     foreach_ipsec_output_next
 351 #undef _
 352   },
 353 };
 354
 355 VLIB_NODE_FN (ipsec6_output_node) (vlib_main_t * vm,
 356                                    vlib_node_runtime_t * node,
 357                                    vlib_frame_t * frame)
 358 {
 359   return ipsec_output_inline (vm, node, frame, 1);
 360 }
 361
 362 VLIB_REGISTER_NODE (ipsec6_output_node) = {
 363   .name = "ipsec6-output-feature",
 364   .vector_size = sizeof (u32),
 365   .format_trace = format_ipsec_output_trace,
 366   .type = VLIB_NODE_TYPE_INTERNAL,
 367
 368   .n_errors = ARRAY_LEN(ipsec_output_error_strings),
 369   .error_strings = ipsec_output_error_strings,
 370
 371   .n_next_nodes = IPSEC_OUTPUT_N_NEXT,
 372   .next_nodes = {
 373 #define _(s,n) [IPSEC_OUTPUT_NEXT_##s] = n,
 374     foreach_ipsec_output_next
 375 #undef _
 376   },
 377 };
 378