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
  19 #include <vnet/vxlan-gbp/vxlan_gbp_packet.h>
  20 #include <vnet/vxlan-gbp/vxlan_gbp.h>
  21
  22 #define foreach_gbp_policy                      \
  23   _(DENY,    "deny")                            \
  24   _(REFLECTION, "reflection")
  25
  26 typedef enum
  27 {
  28 #define _(sym,str) GBP_POLICY_ERROR_##sym,
  29   foreach_gbp_policy_error
  30 #undef _
  31     GBP_POLICY_N_ERROR,
  32 } gbp_policy_error_t;
  33
  34 static char *gbp_policy_error_strings[] = {
  35 #define _(sym,string) string,
  36   foreach_gbp_policy_error
  37 #undef _
  38 };
  39
  40 typedef enum
  41 {
  42   GBP_POLICY_NEXT_DROP,
  43   GBP_POLICY_N_NEXT,
  44 } gbp_policy_next_t;
  45
  46 /**
  47  * per-packet trace data
  48  */
  49 typedef struct gbp_policy_trace_t_
  50 {
  51   /* per-pkt trace data */
  52   u32 sclass;
  53   u32 dst_epg;
  54   u32 acl_index;
  55   u32 allowed;
  56   u32 flags;
  57 } gbp_policy_trace_t;
  58
  59 always_inline dpo_proto_t
  60 ethertype_to_dpo_proto (u16 etype)
  61 {
  62   etype = clib_net_to_host_u16 (etype);
  63
  64   switch (etype)
  65     {
  66     case ETHERNET_TYPE_IP4:
  67       return (DPO_PROTO_IP4);
  68     case ETHERNET_TYPE_IP6:
  69       return (DPO_PROTO_IP6);
  70     }
  71
  72   return (DPO_PROTO_NONE);
  73 }
  74
  75 always_inline u32
  76 gbp_rule_l2_redirect (const gbp_rule_t * gu, vlib_buffer_t * b0)
  77 {
  78   const ethernet_header_t *eth0;
  79   const dpo_id_t *dpo;
  80   dpo_proto_t dproto;
  81
  82   eth0 = vlib_buffer_get_current (b0);
  83   /* pop the ethernet header to prepare for L3 rewrite */
  84   vlib_buffer_advance (b0, vnet_buffer (b0)->l2.l2_len);
  85
  86   dproto = ethertype_to_dpo_proto (eth0->type);
  87   dpo = &gu->gu_dpo[GBP_POLICY_NODE_L2][dproto];
  88
  89   /* save the LB index for the next node and reset the IP flow hash
  90    * so it's recalculated */
  91   vnet_buffer (b0)->ip.adj_index[VLIB_TX] = dpo->dpoi_index;
  92   vnet_buffer (b0)->ip.flow_hash = 0;
  93
  94   return (dpo->dpoi_next_node);
  95 }
  96
  97 always_inline u8
  98 gbp_policy_is_ethertype_allowed (const gbp_contract_t * gc0, u16 ethertype)
  99 {
 100   u16 *et;
 101
 102   vec_foreach (et, gc0->gc_allowed_ethertypes)
 103   {
 104     if (*et == ethertype)
 105       return (1);
 106   }
 107   return (0);
 108 }
 109
 110 static uword
 111 gbp_policy_inline (vlib_main_t * vm,
 112                    vlib_node_runtime_t * node,
 113                    vlib_frame_t * frame, u8 is_port_based)
 114 {
 115   gbp_main_t *gm = &gbp_main;
 116   gbp_policy_main_t *gpm = &gbp_policy_main;
 117   u32 n_left_from, *from, *to_next;
 118   u32 next_index, thread_index;
 119   u32 n_allow_intra, n_allow_a_bit, n_allow_sclass_1;
 120
 121   next_index = 0;
 122   n_left_from = frame->n_vectors;
 123   from = vlib_frame_vector_args (frame);
 124   thread_index = vm->thread_index;
 125   n_allow_intra = n_allow_a_bit = n_allow_sclass_1 = 0;
 126
 127   while (n_left_from > 0)
 128     {
 129       u32 n_left_to_next;
 130
 131       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 132
 133       while (n_left_from > 0 && n_left_to_next > 0)
 134         {
 135           const ethernet_header_t *h0;
 136           const gbp_endpoint_t *ge0;
 137           const gbp_contract_t *gc0;
 138           gbp_policy_next_t next0;
 139           gbp_contract_key_t key0;
 140           u32 bi0, sw_if_index0;
 141           vlib_buffer_t *b0;
 142           index_t gci0;
 143
 144           gc0 = NULL;
 145           next0 = GBP_POLICY_NEXT_DROP;
 146           bi0 = from[0];
 147           to_next[0] = bi0;
 148           from += 1;
 149           to_next += 1;
 150           n_left_from -= 1;
 151           n_left_to_next -= 1;
 152
 153           b0 = vlib_get_buffer (vm, bi0);
 154           h0 = vlib_buffer_get_current (b0);
 155           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 156
 157           /*
 158            * Reflection check; in and out on an ivxlan tunnel
 159            */
 160           if ((~0 != vxlan_gbp_tunnel_by_sw_if_index (sw_if_index0)) &&
 161               (vnet_buffer2 (b0)->gbp.flags & VXLAN_GBP_GPFLAGS_R))
 162             {
 163               goto trace;
 164             }
 165
 166           /*
 167            * If the A-bit is set then policy has already been applied
 168            * and we skip enforcement here.
 169            */
 170           if (vnet_buffer2 (b0)->gbp.flags & VXLAN_GBP_GPFLAGS_A)
 171             {
 172               next0 = vnet_l2_feature_next (b0,
 173                                             gpm->l2_output_feat_next
 174                                             [is_port_based],
 175                                             (is_port_based ?
 176                                              L2OUTPUT_FEAT_GBP_POLICY_PORT :
 177                                              L2OUTPUT_FEAT_GBP_POLICY_MAC));
 178               n_allow_a_bit++;
 179               key0.as_u32 = ~0;
 180               goto trace;
 181             }
 182
 183           /*
 184            * determine the src and dst EPG
 185            */
 186           if (is_port_based)
 187             ge0 = gbp_endpoint_find_itf (sw_if_index0);
 188           else
 189             ge0 = gbp_endpoint_find_mac (h0->dst_address,
 190                                          vnet_buffer (b0)->l2.bd_index);
 191
 192           if (NULL != ge0)
 193             key0.gck_dst = ge0->ge_fwd.gef_sclass;
 194           else
 195             {
 196               /* If you cannot determine the destination EP then drop */
 197               b0->error = node->errors[GBP_POLICY_ERROR_DROP_NO_DCLASS];
 198               goto trace;
 199             }
 200           key0.gck_src = vnet_buffer2 (b0)->gbp.sclass;
 201
 202           if (SCLASS_INVALID != key0.gck_src)
 203             {
 204               if (PREDICT_FALSE (key0.gck_src == key0.gck_dst))
 205                 {
 206                   /*
 207                    * intra-epg allowed
 208                    */
 209                   next0 =
 210                     vnet_l2_feature_next (b0,
 211                                           gpm->l2_output_feat_next
 212                                           [is_port_based],
 213                                           (is_port_based ?
 214                                            L2OUTPUT_FEAT_GBP_POLICY_PORT :
 215                                            L2OUTPUT_FEAT_GBP_POLICY_MAC));
 216                   vnet_buffer2 (b0)->gbp.flags |= VXLAN_GBP_GPFLAGS_A;
 217                   n_allow_intra++;
 218                 }
 219               else if (PREDICT_FALSE (key0.gck_src == 1 || key0.gck_dst == 1))
 220                 {
 221                   /*
 222                    * sclass or dclass 1 allowed
 223                    */
 224                   next0 =
 225                     vnet_l2_feature_next (b0,
 226                                           gpm->l2_output_feat_next
 227                                           [is_port_based],
 228                                           (is_port_based ?
 229                                            L2OUTPUT_FEAT_GBP_POLICY_PORT :
 230                                            L2OUTPUT_FEAT_GBP_POLICY_MAC));
 231                   vnet_buffer2 (b0)->gbp.flags |= VXLAN_GBP_GPFLAGS_A;
 232                   n_allow_sclass_1++;
 233                 }
 234               else
 235                 {
 236                   gci0 = gbp_contract_find (&key0);
 237
 238                   if (INDEX_INVALID != gci0)
 239                     {
 240                       u32 rule_match_p0, trace_bitmap0;
 241                       fa_5tuple_opaque_t pkt_5tuple0;
 242                       u32 acl_pos_p0, acl_match_p0;
 243                       u8 is_ip60, l2_len0, action0;
 244                       const gbp_rule_t *gu;
 245                       u16 ether_type0;
 246                       const u8 *h0;
 247
 248                       vlib_prefetch_combined_counter
 249                         (&gbp_contract_drop_counters, thread_index, gci0);
 250                       vlib_prefetch_combined_counter
 251                         (&gbp_contract_permit_counters, thread_index, gci0);
 252
 253                       action0 = 0;
 254                       gc0 = gbp_contract_get (gci0);
 255                       l2_len0 = vnet_buffer (b0)->l2.l2_len;
 256                       h0 = vlib_buffer_get_current (b0);
 257
 258                       ether_type0 = *(u16 *) (h0 + l2_len0 - 2);
 259
 260                       if (!gbp_policy_is_ethertype_allowed (gc0, ether_type0))
 261                         {
 262                           /*
 263                            * black list model so drop
 264                            */
 265                           b0->error =
 266                             node->errors[GBP_POLICY_ERROR_DROP_ETHER_TYPE];
 267
 268                           vlib_increment_combined_counter
 269                             (&gbp_contract_drop_counters,
 270                              thread_index,
 271                              gci0, 1, vlib_buffer_length_in_chain (vm, b0));
 272
 273                           goto trace;
 274                         }
 275
 276                       if ((ether_type0 ==
 277                            clib_net_to_host_u16 (ETHERNET_TYPE_IP6))
 278                           || (ether_type0 ==
 279                               clib_net_to_host_u16 (ETHERNET_TYPE_IP4)))
 280                         {
 281                           is_ip60 =
 282                             (ether_type0 ==
 283                              clib_net_to_host_u16 (ETHERNET_TYPE_IP6)) ? 1 :
 284                             0;
 285                           /*
 286                            * tests against the ACL
 287                            */
 288                           acl_plugin_fill_5tuple_inline (gm->
 289                                                          acl_plugin.p_acl_main,
 290                                                          gc0->gc_lc_index, b0,
 291                                                          is_ip60,
 292                                                          /* is_input */ 0,
 293                                                          /* is_l2_path */ 1,
 294                                                          &pkt_5tuple0);
 295                           acl_plugin_match_5tuple_inline (gm->
 296                                                           acl_plugin.p_acl_main,
 297                                                           gc0->gc_lc_index,
 298                                                           &pkt_5tuple0,
 299                                                           is_ip60, &action0,
 300                                                           &acl_pos_p0,
 301                                                           &acl_match_p0,
 302                                                           &rule_match_p0,
 303                                                           &trace_bitmap0);
 304
 305                           if (action0 > 0)
 306                             {
 307                               vnet_buffer2 (b0)->gbp.flags |=
 308                                 VXLAN_GBP_GPFLAGS_A;
 309                               gu =
 310                                 gbp_rule_get (gc0->gc_rules[rule_match_p0]);
 311
 312                               switch (gu->gu_action)
 313                                 {
 314                                 case GBP_RULE_PERMIT:
 315                                   next0 = vnet_l2_feature_next
 316                                     (b0,
 317                                      gpm->l2_output_feat_next
 318                                      [is_port_based],
 319                                      (is_port_based ?
 320                                       L2OUTPUT_FEAT_GBP_POLICY_PORT :
 321                                       L2OUTPUT_FEAT_GBP_POLICY_MAC));
 322                                   break;
 323                                 case GBP_RULE_DENY:
 324                                   next0 = GBP_POLICY_NEXT_DROP;
 325                                   break;
 326                                 case GBP_RULE_REDIRECT:
 327                                   next0 = gbp_rule_l2_redirect (gu, b0);
 328                                   break;
 329                                 }
 330                             }
 331                         }
 332                       if (next0 == GBP_POLICY_NEXT_DROP)
 333                         {
 334                           vlib_increment_combined_counter
 335                             (&gbp_contract_drop_counters,
 336                              thread_index,
 337                              gci0, 1, vlib_buffer_length_in_chain (vm, b0));
 338                           b0->error =
 339                             node->errors[GBP_POLICY_ERROR_DROP_CONTRACT];
 340                         }
 341                       else
 342                         {
 343                           vlib_increment_combined_counter
 344                             (&gbp_contract_permit_counters,
 345                              thread_index,
 346                              gci0, 1, vlib_buffer_length_in_chain (vm, b0));
 347                         }
 348                     }
 349                   else
 350                     {
 351                       b0->error =
 352                         node->errors[GBP_POLICY_ERROR_DROP_NO_CONTRACT];
 353                     }
 354                 }
 355             }
 356           else
 357             {
 358               /*
 359                * the src EPG is not set when the packet arrives on an EPG
 360                * uplink interface and we do not need to apply policy
 361                */
 362               next0 =
 363                 vnet_l2_feature_next (b0,
 364                                       gpm->l2_output_feat_next[is_port_based],
 365                                       (is_port_based ?
 366                                        L2OUTPUT_FEAT_GBP_POLICY_PORT :
 367                                        L2OUTPUT_FEAT_GBP_POLICY_MAC));
 368             }
 369
 370         trace:
 371           if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
 372             {
 373               gbp_policy_trace_t *t =
 374                 vlib_add_trace (vm, node, b0, sizeof (*t));
 375               t->sclass = key0.gck_src;
 376               t->dst_epg = key0.gck_dst;
 377               t->acl_index = (gc0 ? gc0->gc_acl_index : ~0);
 378               t->allowed = (next0 != GBP_POLICY_NEXT_DROP);
 379               t->flags = vnet_buffer2 (b0)->gbp.flags;
 380             }
 381
 382           /* verify speculative enqueue, maybe switch current next frame */
 383           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 384                                            to_next, n_left_to_next,
 385                                            bi0, next0);
 386         }
 387
 388       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 389     }
 390
 391   vlib_node_increment_counter (vm, node->node_index,
 392                                GBP_POLICY_ERROR_ALLOW_INTRA, n_allow_intra);
 393   vlib_node_increment_counter (vm, node->node_index,
 394                                GBP_POLICY_ERROR_ALLOW_A_BIT, n_allow_a_bit);
 395   vlib_node_increment_counter (vm, node->node_index,
 396                                GBP_POLICY_ERROR_ALLOW_SCLASS_1,
 397                                n_allow_sclass_1);
 398
 399   return frame->n_vectors;
 400 }
 401
 402 VLIB_NODE_FN (gbp_policy_port_node) (vlib_main_t * vm,
 403                                      vlib_node_runtime_t * node,
 404                                      vlib_frame_t * frame)
 405 {
 406   return (gbp_policy_inline (vm, node, frame, 1));
 407 }
 408
 409 VLIB_NODE_FN (gbp_policy_mac_node) (vlib_main_t * vm,
 410                                     vlib_node_runtime_t * node,
 411                                     vlib_frame_t * frame)
 412 {
 413   return (gbp_policy_inline (vm, node, frame, 0));
 414 }
 415
 416 /* packet trace format function */
 417 static u8 *
 418 format_gbp_policy_trace (u8 * s, va_list * args)
 419 {
 420   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 421   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 422   gbp_policy_trace_t *t = va_arg (*args, gbp_policy_trace_t *);
 423
 424   s =
 425     format (s, "sclass:%d, dst:%d, acl:%d allowed:%d flags:%U",
 426             t->sclass, t->dst_epg, t->acl_index, t->allowed,
 427             format_vxlan_gbp_header_gpflags, t->flags);
 428
 429   return s;
 430 }
 431
 432 /* *INDENT-OFF* */
 433 VLIB_REGISTER_NODE (gbp_policy_port_node) = {
 434   .name = "gbp-policy-port",
 435   .vector_size = sizeof (u32),
 436   .format_trace = format_gbp_policy_trace,
 437   .type = VLIB_NODE_TYPE_INTERNAL,
 438
 439   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 440   .error_strings = gbp_policy_error_strings,
 441
 442   .n_next_nodes = GBP_POLICY_N_NEXT,
 443   .next_nodes = {
 444     [GBP_POLICY_NEXT_DROP] = "error-drop",
 445   },
 446 };
 447
 448 VLIB_REGISTER_NODE (gbp_policy_mac_node) = {
 449   .name = "gbp-policy-mac",
 450   .vector_size = sizeof (u32),
 451   .format_trace = format_gbp_policy_trace,
 452   .type = VLIB_NODE_TYPE_INTERNAL,
 453
 454   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 455   .error_strings = gbp_policy_error_strings,
 456
 457   .n_next_nodes = GBP_POLICY_N_NEXT,
 458   .next_nodes = {
 459     [GBP_POLICY_NEXT_DROP] = "error-drop",
 460   },
 461 };
 462
 463 /* *INDENT-ON* */
 464
 465 /*
 466  * fd.io coding-style-patch-verification: ON
 467  *
 468  * Local Variables:
 469  * eval: (c-set-style "gnu")
 470  * End:
 471  */