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