src/plugins/gbp/gbp_policy_node.c

   1 /*
   2  * Copyright (c) 2018 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <plugins/gbp/gbp.h>
  17 #include <plugins/gbp/gbp_classify.h>
  18 #include <plugins/gbp/gbp_policy_dpo.h>
  19 #include <plugins/gbp/gbp_bridge_domain.h>
  20 #include <plugins/gbp/gbp_ext_itf.h>
  21
  22 #include <vnet/vxlan-gbp/vxlan_gbp_packet.h>
  23 #include <vnet/vxlan-gbp/vxlan_gbp.h>
  24
  25 #define foreach_gbp_policy                      \
  26   _(DENY,    "deny")                            \
  27   _(REFLECTION, "reflection")
  28
  29 typedef enum
  30 {
  31 #define _(sym,str) GBP_POLICY_ERROR_##sym,
  32   foreach_gbp_policy_error
  33 #undef _
  34     GBP_POLICY_N_ERROR,
  35 } gbp_policy_error_t;
  36
  37 static char *gbp_policy_error_strings[] = {
  38 #define _(sym,string) string,
  39   foreach_gbp_policy_error
  40 #undef _
  41 };
  42
  43 typedef enum
  44 {
  45   GBP_POLICY_NEXT_DROP,
  46   GBP_POLICY_N_NEXT,
  47 } gbp_policy_next_t;
  48
  49 /**
  50  * per-packet trace data
  51  */
  52 typedef struct gbp_policy_trace_t_
  53 {
  54   /* per-pkt trace data */
  55   gbp_scope_t scope;
  56   sclass_t sclass;
  57   sclass_t dclass;
  58   u32 acl_index;
  59   u32 allowed;
  60   u32 flags;
  61 } gbp_policy_trace_t;
  62
  63 always_inline dpo_proto_t
  64 ethertype_to_dpo_proto (u16 etype)
  65 {
  66   etype = clib_net_to_host_u16 (etype);
  67
  68   switch (etype)
  69     {
  70     case ETHERNET_TYPE_IP4:
  71       return (DPO_PROTO_IP4);
  72     case ETHERNET_TYPE_IP6:
  73       return (DPO_PROTO_IP6);
  74     }
  75
  76   return (DPO_PROTO_NONE);
  77 }
  78
  79 always_inline u32
  80 gbp_rule_l2_redirect (const gbp_rule_t * gu, vlib_buffer_t * b0)
  81 {
  82   const ethernet_header_t *eth0;
  83   const dpo_id_t *dpo;
  84   dpo_proto_t dproto;
  85
  86   eth0 = vlib_buffer_get_current (b0);
  87   /* pop the ethernet header to prepare for L3 rewrite */
  88   vlib_buffer_advance (b0, vnet_buffer (b0)->l2.l2_len);
  89
  90   dproto = ethertype_to_dpo_proto (eth0->type);
  91   dpo = &gu->gu_dpo[GBP_POLICY_NODE_L2][dproto];
  92
  93   /* save the LB index for the next node and reset the IP flow hash
  94    * so it's recalculated */
  95   vnet_buffer (b0)->ip.adj_index[VLIB_TX] = dpo->dpoi_index;
  96   vnet_buffer (b0)->ip.flow_hash = 0;
  97
  98   return (dpo->dpoi_next_node);
  99 }
 100
 101 always_inline u8
 102 gbp_policy_is_ethertype_allowed (const gbp_contract_t * gc0, u16 ethertype)
 103 {
 104   u16 *et;
 105
 106   vec_foreach (et, gc0->gc_allowed_ethertypes)
 107   {
 108     if (*et == ethertype)
 109       return (1);
 110   }
 111   return (0);
 112 }
 113
 114 static_always_inline gbp_policy_next_t
 115 gbp_policy_l2_feature_next (gbp_policy_main_t * gpm, vlib_buffer_t * b,
 116                             const gbp_policy_type_t type)
 117 {
 118   u32 feat_bit;
 119
 120   switch (type)
 121     {
 122     case GBP_POLICY_PORT:
 123       feat_bit = L2OUTPUT_FEAT_GBP_POLICY_PORT;
 124       break;
 125     case GBP_POLICY_MAC:
 126       feat_bit = L2OUTPUT_FEAT_GBP_POLICY_MAC;
 127       break;
 128     case GBP_POLICY_LPM:
 129       feat_bit = L2OUTPUT_FEAT_GBP_POLICY_LPM;
 130       break;
 131     default:
 132       return GBP_POLICY_NEXT_DROP;
 133     }
 134
 135   return vnet_l2_feature_next (b, gpm->l2_output_feat_next[type], feat_bit);
 136 }
 137
 138 static uword
 139 gbp_policy_inline (vlib_main_t * vm,
 140                    vlib_node_runtime_t * node,
 141                    vlib_frame_t * frame, const gbp_policy_type_t type)
 142 {
 143   gbp_main_t *gm = &gbp_main;
 144   gbp_policy_main_t *gpm = &gbp_policy_main;
 145   u32 n_left_from, *from, *to_next;
 146   u32 next_index, thread_index;
 147   u32 n_allow_intra, n_allow_a_bit, n_allow_sclass_1;
 148
 149   next_index = 0;
 150   n_left_from = frame->n_vectors;
 151   from = vlib_frame_vector_args (frame);
 152   thread_index = vm->thread_index;
 153   n_allow_intra = n_allow_a_bit = n_allow_sclass_1 = 0;
 154
 155   while (n_left_from > 0)
 156     {
 157       u32 n_left_to_next;
 158
 159       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 160
 161       while (n_left_from > 0 && n_left_to_next > 0)
 162         {
 163           const ethernet_header_t *h0;
 164           const gbp_endpoint_t *ge0;
 165           const gbp_contract_t *gc0;
 166           gbp_policy_next_t next0;
 167           gbp_contract_key_t key0;
 168           u32 bi0, sw_if_index0;
 169           vlib_buffer_t *b0;
 170           index_t gci0;
 171
 172           gc0 = NULL;
 173           next0 = GBP_POLICY_NEXT_DROP;
 174           bi0 = from[0];
 175           to_next[0] = bi0;
 176           from += 1;
 177           to_next += 1;
 178           n_left_from -= 1;
 179           n_left_to_next -= 1;
 180
 181           b0 = vlib_get_buffer (vm, bi0);
 182           h0 = vlib_buffer_get_current (b0);
 183           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 184
 185           /* zero out the key to ensure the pad space is clear */
 186           key0.as_u64 = 0;
 187
 188           /*
 189            * Reflection check; in and out on an ivxlan tunnel
 190            */
 191           if ((~0 != vxlan_gbp_tunnel_by_sw_if_index (sw_if_index0)) &&
 192               (vnet_buffer2 (b0)->gbp.flags & VXLAN_GBP_GPFLAGS_R))
 193             {
 194               goto trace;
 195             }
 196
 197           /*
 198            * If the A-bit is set then policy has already been applied
 199            * and we skip enforcement here.
 200            */
 201           if (vnet_buffer2 (b0)->gbp.flags & VXLAN_GBP_GPFLAGS_A)
 202             {
 203               next0 = gbp_policy_l2_feature_next (gpm, b0, type);
 204               n_allow_a_bit++;
 205               key0.as_u64 = ~0;
 206               goto trace;
 207             }
 208
 209           /*
 210            * determine the src and dst EPG
 211            */
 212
 213           key0.gck_dst = SCLASS_INVALID;
 214
 215           if (GBP_POLICY_LPM == type)
 216             {
 217               const ip4_address_t *ip4 = 0;
 218               const ip6_address_t *ip6 = 0;
 219               const dpo_proto_t proto =
 220                 gbp_classify_get_ip_address (h0, &ip4, &ip6,
 221                                              GBP_CLASSIFY_GET_IP_DST);
 222               if (PREDICT_TRUE (DPO_PROTO_NONE != proto))
 223                 {
 224                   const gbp_ext_itf_t *ext_itf =
 225                     gbp_ext_itf_get (sw_if_index0);
 226                   const gbp_policy_dpo_t *gpd =
 227                     gbp_classify_get_gpd (ip4, ip6,
 228                                           ext_itf->gx_fib_index[proto]);
 229                   if (gpd)
 230                     key0.gck_dst = gpd->gpd_sclass;
 231                 }
 232             }
 233           else
 234             {
 235               if (GBP_POLICY_PORT == type)
 236                 ge0 = gbp_endpoint_find_itf (sw_if_index0);
 237               else
 238                 ge0 = gbp_endpoint_find_mac (h0->dst_address,
 239                                              vnet_buffer (b0)->l2.bd_index);
 240               if (NULL != ge0)
 241                 key0.gck_dst = ge0->ge_fwd.gef_sclass;
 242             }
 243
 244           if (SCLASS_INVALID == key0.gck_dst)
 245             {
 246               /* If you cannot determine the destination EP then drop */
 247               b0->error = node->errors[GBP_POLICY_ERROR_DROP_NO_DCLASS];
 248               goto trace;
 249             }
 250           key0.gck_src = vnet_buffer2 (b0)->gbp.sclass;
 251
 252           if (SCLASS_INVALID != key0.gck_src)
 253             {
 254               if (PREDICT_FALSE (key0.gck_src == key0.gck_dst))
 255                 {
 256                   /*
 257                    * intra-epg allowed
 258                    */
 259                   next0 = gbp_policy_l2_feature_next (gpm, b0, type);
 260                   vnet_buffer2 (b0)->gbp.flags |= VXLAN_GBP_GPFLAGS_A;
 261                   n_allow_intra++;
 262                 }
 263               else if (PREDICT_FALSE (key0.gck_src == 1 || key0.gck_dst == 1))
 264                 {
 265                   /*
 266                    * sclass or dclass 1 allowed
 267                    */
 268                   next0 = gbp_policy_l2_feature_next (gpm, b0, type);
 269                   vnet_buffer2 (b0)->gbp.flags |= VXLAN_GBP_GPFLAGS_A;
 270                   n_allow_sclass_1++;
 271                 }
 272               else
 273                 {
 274                   key0.gck_scope =
 275                     gbp_bridge_domain_get_scope (vnet_buffer (b0)->
 276                                                  l2.bd_index);
 277                   gci0 = gbp_contract_find (&key0);
 278
 279                   if (INDEX_INVALID != gci0)
 280                     {
 281                       u32 rule_match_p0, trace_bitmap0;
 282                       fa_5tuple_opaque_t pkt_5tuple0;
 283                       u32 acl_pos_p0, acl_match_p0;
 284                       u8 is_ip60, l2_len0, action0;
 285                       const gbp_rule_t *gu;
 286                       u16 ether_type0;
 287                       const u8 *h0;
 288
 289                       vlib_prefetch_combined_counter
 290                         (&gbp_contract_drop_counters, thread_index, gci0);
 291                       vlib_prefetch_combined_counter
 292                         (&gbp_contract_permit_counters, thread_index, gci0);
 293
 294                       action0 = 0;
 295                       gc0 = gbp_contract_get (gci0);
 296                       l2_len0 = vnet_buffer (b0)->l2.l2_len;
 297                       h0 = vlib_buffer_get_current (b0);
 298
 299                       ether_type0 = *(u16 *) (h0 + l2_len0 - 2);
 300
 301                       if (!gbp_policy_is_ethertype_allowed (gc0, ether_type0))
 302                         {
 303                           /*
 304                            * black list model so drop
 305                            */
 306                           b0->error =
 307                             node->errors[GBP_POLICY_ERROR_DROP_ETHER_TYPE];
 308
 309                           vlib_increment_combined_counter
 310                             (&gbp_contract_drop_counters,
 311                              thread_index,
 312                              gci0, 1, vlib_buffer_length_in_chain (vm, b0));
 313
 314                           goto trace;
 315                         }
 316
 317                       if ((ether_type0 ==
 318                            clib_net_to_host_u16 (ETHERNET_TYPE_IP6))
 319                           || (ether_type0 ==
 320                               clib_net_to_host_u16 (ETHERNET_TYPE_IP4)))
 321                         {
 322                           is_ip60 =
 323                             (ether_type0 ==
 324                              clib_net_to_host_u16 (ETHERNET_TYPE_IP6)) ? 1 :
 325                             0;
 326                           /*
 327                            * tests against the ACL
 328                            */
 329                           acl_plugin_fill_5tuple_inline (gm->
 330                                                          acl_plugin.p_acl_main,
 331                                                          gc0->gc_lc_index, b0,
 332                                                          is_ip60,
 333                                                          /* is_input */ 0,
 334                                                          /* is_l2_path */ 1,
 335                                                          &pkt_5tuple0);
 336                           acl_plugin_match_5tuple_inline (gm->
 337                                                           acl_plugin.p_acl_main,
 338                                                           gc0->gc_lc_index,
 339                                                           &pkt_5tuple0,
 340                                                           is_ip60, &action0,
 341                                                           &acl_pos_p0,
 342                                                           &acl_match_p0,
 343                                                           &rule_match_p0,
 344                                                           &trace_bitmap0);
 345
 346                           if (action0 > 0)
 347                             {
 348                               vnet_buffer2 (b0)->gbp.flags |=
 349                                 VXLAN_GBP_GPFLAGS_A;
 350                               gu =
 351                                 gbp_rule_get (gc0->gc_rules[rule_match_p0]);
 352
 353                               switch (gu->gu_action)
 354                                 {
 355                                 case GBP_RULE_PERMIT:
 356                                   next0 =
 357                                     gbp_policy_l2_feature_next (gpm, b0,
 358                                                                 type);
 359                                   break;
 360                                 case GBP_RULE_DENY:
 361                                   next0 = GBP_POLICY_NEXT_DROP;
 362                                   break;
 363                                 case GBP_RULE_REDIRECT:
 364                                   next0 = gbp_rule_l2_redirect (gu, b0);
 365                                   break;
 366                                 }
 367                             }
 368                         }
 369                       if (next0 == GBP_POLICY_NEXT_DROP)
 370                         {
 371                           vlib_increment_combined_counter
 372                             (&gbp_contract_drop_counters,
 373                              thread_index,
 374                              gci0, 1, vlib_buffer_length_in_chain (vm, b0));
 375                           b0->error =
 376                             node->errors[GBP_POLICY_ERROR_DROP_CONTRACT];
 377                         }
 378                       else
 379                         {
 380                           vlib_increment_combined_counter
 381                             (&gbp_contract_permit_counters,
 382                              thread_index,
 383                              gci0, 1, vlib_buffer_length_in_chain (vm, b0));
 384                         }
 385                     }
 386                   else
 387                     {
 388                       b0->error =
 389                         node->errors[GBP_POLICY_ERROR_DROP_NO_CONTRACT];
 390                     }
 391                 }
 392             }
 393           else
 394             {
 395               /*
 396                * the src EPG is not set when the packet arrives on an EPG
 397                * uplink interface and we do not need to apply policy
 398                */
 399               next0 = gbp_policy_l2_feature_next (gpm, b0, type);
 400             }
 401
 402         trace:
 403           if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
 404             {
 405               gbp_policy_trace_t *t =
 406                 vlib_add_trace (vm, node, b0, sizeof (*t));
 407               t->sclass = key0.gck_src;
 408               t->dclass = key0.gck_dst;
 409               t->scope = key0.gck_scope;
 410               t->acl_index = (gc0 ? gc0->gc_acl_index : ~0);
 411               t->allowed = (next0 != GBP_POLICY_NEXT_DROP);
 412               t->flags = vnet_buffer2 (b0)->gbp.flags;
 413             }
 414
 415           /* verify speculative enqueue, maybe switch current next frame */
 416           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 417                                            to_next, n_left_to_next,
 418                                            bi0, next0);
 419         }
 420
 421       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 422     }
 423
 424   vlib_node_increment_counter (vm, node->node_index,
 425                                GBP_POLICY_ERROR_ALLOW_INTRA, n_allow_intra);
 426   vlib_node_increment_counter (vm, node->node_index,
 427                                GBP_POLICY_ERROR_ALLOW_A_BIT, n_allow_a_bit);
 428   vlib_node_increment_counter (vm, node->node_index,
 429                                GBP_POLICY_ERROR_ALLOW_SCLASS_1,
 430                                n_allow_sclass_1);
 431
 432   return frame->n_vectors;
 433 }
 434
 435 VLIB_NODE_FN (gbp_policy_port_node) (vlib_main_t * vm,
 436                                      vlib_node_runtime_t * node,
 437                                      vlib_frame_t * frame)
 438 {
 439   return (gbp_policy_inline (vm, node, frame, GBP_POLICY_PORT));
 440 }
 441
 442 VLIB_NODE_FN (gbp_policy_mac_node) (vlib_main_t * vm,
 443                                     vlib_node_runtime_t * node,
 444                                     vlib_frame_t * frame)
 445 {
 446   return (gbp_policy_inline (vm, node, frame, GBP_POLICY_MAC));
 447 }
 448
 449 VLIB_NODE_FN (gbp_policy_lpm_node) (vlib_main_t * vm,
 450                                     vlib_node_runtime_t * node,
 451                                     vlib_frame_t * frame)
 452 {
 453   return (gbp_policy_inline (vm, node, frame, GBP_POLICY_LPM));
 454 }
 455
 456 /* packet trace format function */
 457 static u8 *
 458 format_gbp_policy_trace (u8 * s, va_list * args)
 459 {
 460   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 461   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 462   gbp_policy_trace_t *t = va_arg (*args, gbp_policy_trace_t *);
 463
 464   s =
 465     format (s, "scope:%d sclass:%d, dclass:%d, acl:%d allowed:%d flags:%U",
 466             t->scope, t->sclass, t->dclass, t->acl_index, t->allowed,
 467             format_vxlan_gbp_header_gpflags, t->flags);
 468
 469   return s;
 470 }
 471
 472 /* *INDENT-OFF* */
 473 VLIB_REGISTER_NODE (gbp_policy_port_node) = {
 474   .name = "gbp-policy-port",
 475   .vector_size = sizeof (u32),
 476   .format_trace = format_gbp_policy_trace,
 477   .type = VLIB_NODE_TYPE_INTERNAL,
 478
 479   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 480   .error_strings = gbp_policy_error_strings,
 481
 482   .n_next_nodes = GBP_POLICY_N_NEXT,
 483   .next_nodes = {
 484     [GBP_POLICY_NEXT_DROP] = "error-drop",
 485   },
 486 };
 487
 488 VLIB_REGISTER_NODE (gbp_policy_mac_node) = {
 489   .name = "gbp-policy-mac",
 490   .vector_size = sizeof (u32),
 491   .format_trace = format_gbp_policy_trace,
 492   .type = VLIB_NODE_TYPE_INTERNAL,
 493
 494   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 495   .error_strings = gbp_policy_error_strings,
 496
 497   .n_next_nodes = GBP_POLICY_N_NEXT,
 498   .next_nodes = {
 499     [GBP_POLICY_NEXT_DROP] = "error-drop",
 500   },
 501 };
 502
 503 VLIB_REGISTER_NODE (gbp_policy_lpm_node) = {
 504   .name = "gbp-policy-lpm",
 505   .vector_size = sizeof (u32),
 506   .format_trace = format_gbp_policy_trace,
 507   .type = VLIB_NODE_TYPE_INTERNAL,
 508
 509   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 510   .error_strings = gbp_policy_error_strings,
 511
 512   .n_next_nodes = GBP_POLICY_N_NEXT,
 513   .next_nodes = {
 514     [GBP_POLICY_NEXT_DROP] = "error-drop",
 515   },
 516 };
 517
 518 /* *INDENT-ON* */
 519
 520 /*
 521  * fd.io coding-style-patch-verification: ON
 522  *
 523  * Local Variables:
 524  * eval: (c-set-style "gnu")
 525  * End:
 526  */