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;
 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 = 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
 220                 {
 221                   gci0 = gbp_contract_find (&key0);
 222
 223                   if (INDEX_INVALID != gci0)
 224                     {
 225                       u32 rule_match_p0, trace_bitmap0;
 226                       fa_5tuple_opaque_t pkt_5tuple0;
 227                       u32 acl_pos_p0, acl_match_p0;
 228                       u8 is_ip60, l2_len0, action0;
 229                       const gbp_rule_t *gu;
 230                       u16 ether_type0;
 231                       const u8 *h0;
 232
 233                       vlib_prefetch_combined_counter
 234                         (&gbp_contract_drop_counters, thread_index, gci0);
 235                       vlib_prefetch_combined_counter
 236                         (&gbp_contract_permit_counters, thread_index, gci0);
 237
 238                       action0 = 0;
 239                       gc0 = gbp_contract_get (gci0);
 240                       l2_len0 = vnet_buffer (b0)->l2.l2_len;
 241                       h0 = vlib_buffer_get_current (b0);
 242
 243                       ether_type0 = *(u16 *) (h0 + l2_len0 - 2);
 244
 245                       if (!gbp_policy_is_ethertype_allowed (gc0, ether_type0))
 246                         {
 247                           /*
 248                            * black list model so drop
 249                            */
 250                           b0->error =
 251                             node->errors[GBP_POLICY_ERROR_DROP_ETHER_TYPE];
 252
 253                           vlib_increment_combined_counter
 254                             (&gbp_contract_drop_counters,
 255                              thread_index,
 256                              gci0, 1, vlib_buffer_length_in_chain (vm, b0));
 257
 258                           goto trace;
 259                         }
 260
 261                       if ((ether_type0 ==
 262                            clib_net_to_host_u16 (ETHERNET_TYPE_IP6))
 263                           || (ether_type0 ==
 264                               clib_net_to_host_u16 (ETHERNET_TYPE_IP4)))
 265                         {
 266                           is_ip60 =
 267                             (ether_type0 ==
 268                              clib_net_to_host_u16 (ETHERNET_TYPE_IP6)) ? 1 :
 269                             0;
 270                           /*
 271                            * tests against the ACL
 272                            */
 273                           acl_plugin_fill_5tuple_inline (gm->
 274                                                          acl_plugin.p_acl_main,
 275                                                          gc0->gc_lc_index, b0,
 276                                                          is_ip60,
 277                                                          /* is_input */ 0,
 278                                                          /* is_l2_path */ 1,
 279                                                          &pkt_5tuple0);
 280                           acl_plugin_match_5tuple_inline (gm->
 281                                                           acl_plugin.p_acl_main,
 282                                                           gc0->gc_lc_index,
 283                                                           &pkt_5tuple0,
 284                                                           is_ip60, &action0,
 285                                                           &acl_pos_p0,
 286                                                           &acl_match_p0,
 287                                                           &rule_match_p0,
 288                                                           &trace_bitmap0);
 289
 290                           if (action0 > 0)
 291                             {
 292                               vnet_buffer2 (b0)->gbp.flags |=
 293                                 VXLAN_GBP_GPFLAGS_A;
 294                               gu =
 295                                 gbp_rule_get (gc0->gc_rules[rule_match_p0]);
 296
 297                               switch (gu->gu_action)
 298                                 {
 299                                 case GBP_RULE_PERMIT:
 300                                   next0 = vnet_l2_feature_next
 301                                     (b0,
 302                                      gpm->l2_output_feat_next
 303                                      [is_port_based],
 304                                      (is_port_based ?
 305                                       L2OUTPUT_FEAT_GBP_POLICY_PORT :
 306                                       L2OUTPUT_FEAT_GBP_POLICY_MAC));
 307                                   break;
 308                                 case GBP_RULE_DENY:
 309                                   next0 = GBP_POLICY_NEXT_DROP;
 310                                   break;
 311                                 case GBP_RULE_REDIRECT:
 312                                   next0 = gbp_rule_l2_redirect (gu, b0);
 313                                   break;
 314                                 }
 315                             }
 316                         }
 317                       if (next0 == GBP_POLICY_NEXT_DROP)
 318                         {
 319                           vlib_increment_combined_counter
 320                             (&gbp_contract_drop_counters,
 321                              thread_index,
 322                              gci0, 1, vlib_buffer_length_in_chain (vm, b0));
 323                           b0->error =
 324                             node->errors[GBP_POLICY_ERROR_DROP_CONTRACT];
 325                         }
 326                       else
 327                         {
 328                           vlib_increment_combined_counter
 329                             (&gbp_contract_permit_counters,
 330                              thread_index,
 331                              gci0, 1, vlib_buffer_length_in_chain (vm, b0));
 332                         }
 333                     }
 334                   else
 335                     {
 336                       b0->error =
 337                         node->errors[GBP_POLICY_ERROR_DROP_NO_CONTRACT];
 338                     }
 339                 }
 340             }
 341           else
 342             {
 343               /*
 344                * the src EPG is not set when the packet arrives on an EPG
 345                * uplink interface and we do not need to apply policy
 346                */
 347               next0 =
 348                 vnet_l2_feature_next (b0,
 349                                       gpm->l2_output_feat_next[is_port_based],
 350                                       (is_port_based ?
 351                                        L2OUTPUT_FEAT_GBP_POLICY_PORT :
 352                                        L2OUTPUT_FEAT_GBP_POLICY_MAC));
 353             }
 354
 355         trace:
 356           if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
 357             {
 358               gbp_policy_trace_t *t =
 359                 vlib_add_trace (vm, node, b0, sizeof (*t));
 360               t->sclass = key0.gck_src;
 361               t->dst_epg = key0.gck_dst;
 362               t->acl_index = (gc0 ? gc0->gc_acl_index : ~0);
 363               t->allowed = (next0 != GBP_POLICY_NEXT_DROP);
 364               t->flags = vnet_buffer2 (b0)->gbp.flags;
 365             }
 366
 367           /* verify speculative enqueue, maybe switch current next frame */
 368           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 369                                            to_next, n_left_to_next,
 370                                            bi0, next0);
 371         }
 372
 373       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 374     }
 375
 376   vlib_node_increment_counter (vm, node->node_index,
 377                                GBP_POLICY_ERROR_ALLOW_INTRA, n_allow_intra);
 378   vlib_node_increment_counter (vm, node->node_index,
 379                                GBP_POLICY_ERROR_ALLOW_A_BIT, n_allow_a_bit);
 380
 381   return frame->n_vectors;
 382 }
 383
 384 VLIB_NODE_FN (gbp_policy_port_node) (vlib_main_t * vm,
 385                                      vlib_node_runtime_t * node,
 386                                      vlib_frame_t * frame)
 387 {
 388   return (gbp_policy_inline (vm, node, frame, 1));
 389 }
 390
 391 VLIB_NODE_FN (gbp_policy_mac_node) (vlib_main_t * vm,
 392                                     vlib_node_runtime_t * node,
 393                                     vlib_frame_t * frame)
 394 {
 395   return (gbp_policy_inline (vm, node, frame, 0));
 396 }
 397
 398 /* packet trace format function */
 399 static u8 *
 400 format_gbp_policy_trace (u8 * s, va_list * args)
 401 {
 402   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 403   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 404   gbp_policy_trace_t *t = va_arg (*args, gbp_policy_trace_t *);
 405
 406   s =
 407     format (s, "sclass:%d, dst:%d, acl:%d allowed:%d flags:%U",
 408             t->sclass, t->dst_epg, t->acl_index, t->allowed,
 409             format_vxlan_gbp_header_gpflags, t->flags);
 410
 411   return s;
 412 }
 413
 414 /* *INDENT-OFF* */
 415 VLIB_REGISTER_NODE (gbp_policy_port_node) = {
 416   .name = "gbp-policy-port",
 417   .vector_size = sizeof (u32),
 418   .format_trace = format_gbp_policy_trace,
 419   .type = VLIB_NODE_TYPE_INTERNAL,
 420
 421   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 422   .error_strings = gbp_policy_error_strings,
 423
 424   .n_next_nodes = GBP_POLICY_N_NEXT,
 425   .next_nodes = {
 426     [GBP_POLICY_NEXT_DROP] = "error-drop",
 427   },
 428 };
 429
 430 VLIB_REGISTER_NODE (gbp_policy_mac_node) = {
 431   .name = "gbp-policy-mac",
 432   .vector_size = sizeof (u32),
 433   .format_trace = format_gbp_policy_trace,
 434   .type = VLIB_NODE_TYPE_INTERNAL,
 435
 436   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 437   .error_strings = gbp_policy_error_strings,
 438
 439   .n_next_nodes = GBP_POLICY_N_NEXT,
 440   .next_nodes = {
 441     [GBP_POLICY_NEXT_DROP] = "error-drop",
 442   },
 443 };
 444
 445 /* *INDENT-ON* */
 446
 447 /*
 448  * fd.io coding-style-patch-verification: ON
 449  *
 450  * Local Variables:
 451  * eval: (c-set-style "gnu")
 452  * End:
 453  */